Sample records for achieve comparable performance

  1. Student Achievement in Ohio Charter Schools: A Comparative and Longitudinal Study

    ERIC Educational Resources Information Center

    Kotler, Ruth M.

    2012-01-01

    The purpose of this study was to investigate fifth-grade student achievement in Ohio public charter schools as compared to student achievement in traditional public schools, and to determine whether the performance of charter schools changed over time. Research questions asked 1) how does student achievement in Ohio's public charters compare to…

  2. A Comparison of Low Performing Students' Achievements in Factoring Cubic Polynomials Using Three Different Strategies

    ERIC Educational Resources Information Center

    Ogbonnaya, Ugorji I.; Mogari, David L.; Machisi, Eric

    2013-01-01

    In this study, repeated measures design was employed to compare low performing students' achievements in factoring cubic polynomials using three strategies. Twenty-five low-performing Grade 12 students from a secondary school in Limpopo province took part in the study. Data was collected using achievement test and was analysed using repeated…

  3. A Comparative Case Study of Factors Distinguishing between High and Low-Performance on Reading Achievement in Elementary Rural Appalachian Schools

    ERIC Educational Resources Information Center

    Chambers, Jennifer R.

    2012-01-01

    This qualitative comparative case study identified factors that distinguish between high and low-performance on reading achievement in elementary rural Appalachian schools. This study determined the most effective instructional reading strategies, as well as other influential factors, implemented by school districts in the rural Appalachia area…

  4. A Comparative Case Study of Factors Distinguishing between High and Low-Performance on Reading Achievement in Elementary Rural Appalachian Schools

    ERIC Educational Resources Information Center

    Chambers, Jennifer; Hausman, Charles

    2014-01-01

    This qualitative comparative case study identified factors that distinguish between high and low-performance on reading achievement in elementary rural Appalachian schools. This study determined the most effective instructional reading strategies, as well as other influential factors, implemented by school districts in the rural Appalachia area…

  5. Identifying achievement goals and their relationship to academic achievement in undergraduate pharmacy students.

    PubMed

    Alrakaf, Saleh; Sainsbury, Erica; Rose, Grenville; Smith, Lorraine

    2014-09-15

    To compare the achievement goal orientations of first-year with those of third-year undergraduate Australian pharmacy students and to examine the relationship of goal orientations to academic achievement. The Achievement Goal Questionnaire was administered to first-year and third-year students during class time. Students' grades were obtained from course coordinators. More first-year students adopted performance-approach and mastery-approach goals than did third-year students. Performance-approach goals were positively correlated with academic achievement in the first year. Chinese Australian students scored the highest in adopting performance-approach goals. Vietnamese Australian students adopted mastery-avoidance goals more than other ethnicities. First-year students were more strongly performance approach goal-oriented than third-year students. Adopting performance-approach goals was positively correlated with academic achievement, while adopting avoidance goals was not. Ethnicity has an effect on the adoption of achievement goals and academic achievement.

  6. Aligning Items and Achievement Levels: A Study Comparing Expert Judgments

    ERIC Educational Resources Information Center

    Kaliski, Pamela; Huff, Kristen; Barry, Carol

    2011-01-01

    For educational achievement tests that employ multiple-choice (MC) items and aim to reliably classify students into performance categories, it is critical to design MC items that are capable of discriminating student performance according to the stated achievement levels. This is accomplished, in part, by clearly understanding how item design…

  7. Medicare Accountable Care Organizations of Diverse Structures Achieve Comparable Quality and Cost Performance.

    PubMed

    Comfort, Leeann N; Shortell, Stephen M; Rodriguez, Hector P; Colla, Carrie H

    2018-01-31

    To examine whether an empirically derived taxonomy of Accountable Care Organizations (ACOs) is associated with quality and spending performance among patients of ACOs in the Medicare Shared Savings Program (MSSP). Three waves of the National Survey of ACOs and corresponding publicly available Centers for Medicare & Medicaid Services performance data for NSACO respondents participating in the MSSP (N = 204); SK&A Office Based Physicians Database from QuintilesIMS. We compare the performance of three ACO types (physician-led, integrated, and hybrid) for three domains: quality, spending, and likelihood of achieving savings. Sources of performance variation within and between ACO types are compared for each performance measure. There is greater heterogeneity within ACO types than between ACO types. There were no consistent differences in quality by ACO type, nor were there differences in likelihood of achieving savings or overall spending per-person-year. There was evidence for higher spending on physician services for physician-led ACOs. ACOs of diverse structures perform comparably on core MSSP quality and spending measures. CMS should maintain its flexibility and continue to support participation of diverse ACOs. Future research to identify modifiable organizational factors that account for performance variation within ACO types may provide insight as to how best to improve ACO performance based on organizational structure and ownership. © Health Research and Educational Trust.

  8. Achieving quality improvement in the nursing home: influence of nursing leadership on communication and teamwork.

    PubMed

    Vogelsmeier, Amy; Scott-Cawiezell, Jill

    2011-01-01

    Leadership, communication, and teamwork are essential elements of organizational capacity and are linked to organizational performance. How those organizations actually achieve improved performance, however, is not clearly understood. In this comparative case study, nursing leadership who facilitated open communication and teamwork achieved improvement while nursing leadership who impeded open communication and teamwork did not.

  9. Relationship between attainment of recommended physical activity guidelines and academic achievement: undergraduate students in Egypt.

    PubMed

    El Ansari, Walid; Stock, Christiane

    2014-07-14

    We assessed and compared by gender, students' achievement of recommended guidelines of four PA forms, and the association between guideline achievement of each of the four PA forms and students' academic performance. Data (2009-2010) comprised 3,271 students (11 faculties) at Assiut University, Egypt. A self-administered questionnaire measured: moderate PA (MPA), vigorous PA (VPA), moderate to vigorous PA (MVPA), muscle-strengthening PA; five socio-demographic variables (gender, age, year of study, father's education, living arrangements during semester); self-rated health; and, academic performance. We compared the levels of four PA forms, socio-demographic variables, and academic performance by gender. Binary logistic regression examined the factors associated with achieving the guidelines of the four PA forms. Linear regression examined the association between frequency of four PA forms and level of academic performance. Nearly equal proportions of males and females (37%, 36%) achieved the MPA guidelines. Significantly more males achieved the VPA, MVPA, and muscle strengthening PA guidelines. Father's education was positively associated with achieving all four PA guidelines (with each increasing educational achievement of the father, student's odds of achieving PA guidelines increased by 7-9%). Students living with their parents or room mates off campus were more likely to achieve the VPA and MVPA guidelines. Students who achieved VPA and MVPA guidelines were more likely to report better academic performance. For all PA forms (except MPA), increasing academic achievement was positively associated with increasing frequency of PA, but standardised Beta (0.05-0.07) suggested a modest correlation between academic achievement and PA frequency. The linear association between frequency of PA and academic achievement, and the finding that the proportions of students who achieved the recommended levels of several forms of PA were below half of the sample call for higher engagement of universities in fostering PA and active lifestyle among students.

  10. Relationship Between Attainment of Recommended Physical Activity Guidelines and Academic Achievement: Undergraduate Students in Egypt

    PubMed Central

    Ansari, Walid El; Stock, Christiane

    2014-01-01

    Introduction: We assessed and compared by gender, students’ achievement of recommended guidelines of four PA forms, and the association between guideline achievement of each of the four PA forms and students’ academic performance. Methods: Data (2009-2010) comprised 3,271 students (11 faculties) at Assiut University, Egypt. A self-administered questionnaire measured: moderate PA (MPA), vigorous PA (VPA), moderate to vigorous PA (MVPA), muscle-strengthening PA; five socio-demographic variables (gender, age, year of study, father’s education, living arrangements during semester); self-rated health; and, academic performance. We compared the levels of four PA forms, socio-demographic variables, and academic performance by gender. Binary logistic regression examined the factors associated with achieving the guidelines of the four PA forms. Linear regression examined the association between frequency of four PA forms and level of academic performance. Results: Nearly equal proportions of males and females (37%, 36%) achieved the MPA guidelines. Significantly more males achieved the VPA, MVPA, and muscle strengthening PA guidelines. Father’s education was positively associated with achieving all four PA guidelines (with each increasing educational achievement of the father, student’s odds of achieving PA guidelines increased by 7-9%). Students living with their parents or room mates off campus were more likely to achieve the VPA and MVPA guidelines. Students who achieved VPA and MVPA guidelines were more likely to report better academic performance. For all PA forms (except MPA), increasing academic achievement was positively associated with increasing frequency of PA, but standardised Beta (0.05-0.07) suggested a modest correlation between academic achievement and PA frequency. Conclusion: The linear association between frequency of PA and academic achievement, and the finding that the proportions of students who achieved the recommended levels of several forms of PA were below half of the sample call for higher engagement of universities in fostering PA and active lifestyle among students. PMID:25169005

  11. Striving for Excellence Sometimes Hinders High Achievers: Performance-Approach Goals Deplete Arithmetical Performance in Students with High Working Memory Capacity

    PubMed Central

    Crouzevialle, Marie; Smeding, Annique; Butera, Fabrizio

    2015-01-01

    We tested whether the goal to attain normative superiority over other students, referred to as performance-approach goals, is particularly distractive for high-Working Memory Capacity (WMC) students—that is, those who are used to being high achievers. Indeed, WMC is positively related to high-order cognitive performance and academic success, a record of success that confers benefits on high-WMC as compared to low-WMC students. We tested whether such benefits may turn out to be a burden under performance-approach goal pursuit. Indeed, for high achievers, aiming to rise above others may represent an opportunity to reaffirm their positive status—a stake susceptible to trigger disruptive outcome concerns that interfere with task processing. Results revealed that with performance-approach goals—as compared to goals with no emphasis on social comparison—the higher the students’ WMC, the lower their performance at a complex arithmetic task (Experiment 1). Crucially, this pattern appeared to be driven by uncertainty regarding the chances to outclass others (Experiment 2). Moreover, an accessibility measure suggested the mediational role played by status-related concerns in the observed disruption of performance. We discuss why high-stake situations can paradoxically lead high-achievers to sub-optimally perform when high-order cognitive performance is at play. PMID:26407097

  12. Comprehensive Achievement Monitoring for Science. Symposium; National Association of Biology Teachers, San Francisco, California, October 27, 1972.

    ERIC Educational Resources Information Center

    White, Mona E.; And Others

    Comprehensive Achievement Monitoring (CAM) is a system designed to provide a curriculum defined in terms of performance objectives, test items to measure student performance on each objective, a set of comparable test forms to evaluate performance, testing throughout the period of the course, computerized analysis and reporting of results after…

  13. Using Comprehensive Achievement Monitoring in the Classroom. Symposium; California Educational Research Association, San Jose, California, November 9, 1972.

    ERIC Educational Resources Information Center

    Easter, John; And Others

    Comprehensive Achievement Monitoring (CAM) is a system designed to provide a curriculum defined in terms of performance objectives, test items to measure student performance on each objective, a set of comparable test forms to evaluate performance, testing throughout the period of the course, computerized analysis and reporting of results after…

  14. Comprehensive Achievement Monitoring in the Sequoia Union High School District. Symposium, California Educational Data Processing Association, December 8, 1972.

    ERIC Educational Resources Information Center

    Easter, John; And Others

    Comprehensive Achievement Monitoring (CAM) is a system designed to provide a curriculum defined in terms of performance objectives, test items to measure student performance on each objective, a set of comparable test forms to evaluate performance, testing throughout the period of course, computerized analysis and reporting of results after test…

  15. The Impact on Student Achievement Following Professional Development on the Principles of Formative Assessment

    ERIC Educational Resources Information Center

    DeNome, Evonne C.

    2015-01-01

    This quantitative study reviews the impact on student achievement following professional development on the principles of formative assessment. The study compared mathematics and reading performance data from student populations with teachers who received training in formative assessment to performance data from student populations with teachers…

  16. Decomposing Achievement Gaps among OECD Countries

    ERIC Educational Resources Information Center

    Zhang, Liang; Lee, Kristen A.

    2011-01-01

    In this study, we use decomposition methods on PISA 2006 data to compare student academic performance across OECD countries. We first establish an empirical model to explain the variation in academic performance across individuals, and then use the Oaxaca-Blinder decomposition method to decompose the achievement gap between each of the OECD…

  17. The Effects of Advanced Placement and International Baccalaureate Programs on Student Achievement

    ERIC Educational Resources Information Center

    Luo, Samia Merza

    2013-01-01

    This study compared student academic achievement in two college readiness programs, Advanced Placement (AP) and International Baccalaureate (IB) and attempted to determine how well program participation predict student performance compared to variables such as SES, parent education level, GPA, gender, and SAT II scores. Finally, the research…

  18. EmptyHeaded: A Relational Engine for Graph Processing

    PubMed Central

    Aberger, Christopher R.; Tu, Susan; Olukotun, Kunle; Ré, Christopher

    2016-01-01

    There are two types of high-performance graph processing engines: low- and high-level engines. Low-level engines (Galois, PowerGraph, Snap) provide optimized data structures and computation models but require users to write low-level imperative code, hence ensuring that efficiency is the burden of the user. In high-level engines, users write in query languages like datalog (SociaLite) or SQL (Grail). High-level engines are easier to use but are orders of magnitude slower than the low-level graph engines. We present EmptyHeaded, a high-level engine that supports a rich datalog-like query language and achieves performance comparable to that of low-level engines. At the core of EmptyHeaded’s design is a new class of join algorithms that satisfy strong theoretical guarantees but have thus far not achieved performance comparable to that of specialized graph processing engines. To achieve high performance, EmptyHeaded introduces a new join engine architecture, including a novel query optimizer and data layouts that leverage single-instruction multiple data (SIMD) parallelism. With this architecture, EmptyHeaded outperforms high-level approaches by up to three orders of magnitude on graph pattern queries, PageRank, and Single-Source Shortest Paths (SSSP) and is an order of magnitude faster than many low-level baselines. We validate that EmptyHeaded competes with the best-of-breed low-level engine (Galois), achieving comparable performance on PageRank and at most 3× worse performance on SSSP. PMID:28077912

  19. Linking TIMSS and NAEP Assessments to Evaluate International Trends in Achievement

    ERIC Educational Resources Information Center

    Lim, Hwanggyu; Sireci, Stephen G.

    2017-01-01

    The Trends in International Mathematics and Science Study (TIMSS) makes it possible to compare the performance of students in the US in Mathematics and Science to the performance of students in other countries. TIMSS uses four international benchmarks for describing student achievement: Low, Intermediate, High, and Advanced. In this study, we…

  20. Traditional vs. Experiential: A Comparative Study of Instructional Methodologies on Student Achievement in New York City Public Schools

    ERIC Educational Resources Information Center

    Mohan, Subhas

    2015-01-01

    This study explores the differences in student achievement on state standardized tests between experiential learning and direct learning instructional methodologies. Specifically, the study compares student performances in Expeditionary Learning schools, which is a Comprehensive School Reform model that utilizes experiential learning, to their…

  1. Identifying the Comparative Academic Performance of Secondary Schools

    ERIC Educational Resources Information Center

    Bendikson, Linda; Hattie, John; Robinson, Viviane

    2011-01-01

    Purpose: One of the features of the New Zealand secondary schools system is that achievement closely reflects the taught curriculum. The National Certificate of Educational Achievement (NCEA) directly assesses student achievement on the secondary school curriculum through a combination of criterion-based internal and external assessments. The…

  2. Evaluation of SAPHIRE: an automated approach to indexing and retrieving medical literature.

    PubMed Central

    Hersh, W.; Hickam, D. H.; Haynes, R. B.; McKibbon, K. A.

    1991-01-01

    An analysis of SAPHIRE, an experimental information retrieval system featuring automated indexing and natural language retrieval, was performed on MEDLINE references using data previously generated for a MEDLINE evaluation. Compared with searches performed by novice and expert physicians using MEDLINE, SAPHIRE achieved comparable recall and precision. While its combined recall and precision performance did not equal the level of librarians, SAPHIRE did achieve a significantly higher level of absolute recall. SAPHIRE has other potential advantages over existing MEDLINE systems. Its natural language interface does not require knowledge of MeSH, and it provides relevance ranking of retrieved references. PMID:1807718

  3. Using Performance Data Gathered at Several Stages of Achievement in Predicting Subsequent Performance.

    ERIC Educational Resources Information Center

    Owen, Steven V.; Feldhusen, John F.

    This study compares the effectiveness of three models of multivariate prediction for academic success in identifying the criterion variance of achievement in nursing education. The first model involves the use of an optimum set of predictors and one equation derived from a regression analysis on first semester grade average in predicting the…

  4. A Comparison of Performance on a Silent Informal Reading Inventory and Achievement on a Standardized Reading Test.

    ERIC Educational Resources Information Center

    Birger, Barbara

    A study compared performance on a silent informal reading inventory and achievement on a standardized reading test, focusing on students' individual skill needs and how effective tests were in identifying specific strengths and weaknesses in these skill areas. Subjects, 25 students entering fourth grade in a primarily middle class suburban…

  5. Self-Efficacy, Adversity Quotient, and Students' Achievement in Mathematics

    ERIC Educational Resources Information Center

    Suryadi, Bambang; Santoso, Teguh Iman

    2017-01-01

    Indonesian students' achievement in mathematics is generally still low compared with other countries. Many psychological factors, both internal and external, influence this poor performance. This study aimed to measure the effect of self-efficacy and the adversity quotient of Grade IX students regarding achievement in mathematics. Both of these…

  6. Comparing the Achievement Goal Orientation of Mathematics Learners with and without Attention-Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Spangenberg, Erica Dorethea

    2017-01-01

    Many learners with different learning challenges are accommodated in the same classroom in South Africa, which could result in poor performance in mathematics. By reinforcing or disregarding certain goals, a teacher can influence the way in which learners learn mathematics. This study compared the achievement goal orientation of Grade Nine…

  7. Comparisons of mathematics achievement of grade 8 students in the United States and the Russian Federation.

    PubMed

    Bazarova, Saodat I; Engelhard, George

    2004-01-01

    Using the Mantel-Haenszel (MH) Procedure, we analyzed data for 7,087 American and 4,022 Russian Grade 8 students from the Third International Mathematics and Science Study (TIMSS) to compare mathematics achievement in the two countries on each of the 124 multiple-choice items. The results of the analyses indicate that the performance of the students on individual multiple-choice mathematics items vary by country. The results also suggest that the relationship between country and item performance differ as a function of content area. A total score of a country's achievement does not provide the whole picture of achievement dynamics; it averages out potentially important information on student achievement and the causes of their performance relative to other countries. The dynamics of achievement across countries will not be revealed unless the analyses are done at the item level.

  8. 49 CFR 555.6 - Basis for application.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... achieved either by design changes or termination of production of nonconforming vehicles; and (v) The total... failure to meet the standard, expressed as comparative performance levels; and (iv) Reasons why the... standard, expressed as comparative performance levels; (iv) The results of any tests conducted on the...

  9. 49 CFR 555.6 - Basis for application.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... achieved either by design changes or termination of production of nonconforming vehicles; and (v) The total... failure to meet the standard, expressed as comparative performance levels; and (iv) Reasons why the... standard, expressed as comparative performance levels; (iv) The results of any tests conducted on the...

  10. 49 CFR 555.6 - Basis for application.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... achieved either by design changes or termination of production of nonconforming vehicles; and (v) The total... failure to meet the standard, expressed as comparative performance levels; and (iv) Reasons why the... standard, expressed as comparative performance levels; (iv) The results of any tests conducted on the...

  11. 49 CFR 555.6 - Basis for application.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... achieved either by design changes or termination of production of nonconforming vehicles; and (v) The total... failure to meet the standard, expressed as comparative performance levels; and (iv) Reasons why the... standard, expressed as comparative performance levels; (iv) The results of any tests conducted on the...

  12. 49 CFR 555.6 - Basis for application.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... achieved either by design changes or termination of production of nonconforming vehicles; and (v) The total... failure to meet the standard, expressed as comparative performance levels; and (iv) Reasons why the... standard, expressed as comparative performance levels; (iv) The results of any tests conducted on the...

  13. Achievement Place: development of the elected manager system1

    PubMed Central

    Phillips, Elery L.; Phillips, Elaine A.; Wolf, Montrose M.; Fixsen, Dean L.

    1973-01-01

    A series of experiments was carried out to compare several administrative systems at Achievement Place, a family style behavior modification program for pre-delinquent boys. One aspect of the motivation system at Achievement Place was the token economy in which the youths could earn or lose points that could be exchanged for privileges. Several arrangements for assigning routine tasks and for providing token consequences for task performance were compared for their effectiveness in accomplishing the tasks and for their preference by the boys. The independent variables studied included: (1) individually assigned tasks versus group assigned tasks; (2) consequences for individual performance versus consequences for group performance; (3) a peer managership that could be earned by the highest bidder versus a peer managership that could be determined democratically by the peers. The results suggested that among those systems studied the system that best met the criteria of effectiveness and preference involved a democratically elected peer manager who had the authority both to give and to take away points for his peers' performances. PMID:16795439

  14. Teaching Business Simulation Games: Comparing Achievements Frontal Teaching vs. eLearning

    NASA Astrophysics Data System (ADS)

    Bregman, David; Keinan, Gila; Korman, Arik; Raanan, Yossi

    This paper addresses the issue of comparing results achieved by students taught the same course but in two drastically different - a regular, frontal method and an eLearning method. The subject taught required intensive communications among the students, thus making the eLearning students, a priori, less likely to do well in it. The research, comparing the achievements of students in a business simulation game over three semesters, shows that the use of eLearning method did not result in any differences in performance, grades or cooperation, thus strengthening the case for using eLearning in this type of course.

  15. Mind the gap: Increased inter-letter spacing as a means of improving reading performance.

    PubMed

    Dotan, Shahar; Katzir, Tami

    2018-06-05

    Theeffects of text display, specificallywithin-word spacing, on children's reading at different developmental levels has barely been investigated.This study explored the influence of manipulating inter-letter spacing on reading performance (accuracy and rate) of beginner Hebrew readers compared with older readers and of low-achieving readers compared with age-matched high-achieving readers.A computer-based isolated word reading task was performed by 132 first and third graders. Words were displayed under two spacing conditions: standard spacing (100%) and increased spacing (150%). Words were balanced for length and frequency across conditions. Results indicated that increased spacing contributed to reading accuracy without affecting reading rate. Interestingly, all first graders benefitted fromthe spaced condition. Thiseffect was found only in long words but not in short words. Among third graders, only low-achieving readers gained in accuracy fromthespaced condition. Thetheoretical and clinical effects ofthefindings are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. The Impact of Classroom Performance System-Based Instruction with Peer Instruction upon Student Achievement and Motivation in Eighth Grade Math Students

    ERIC Educational Resources Information Center

    Allison, Tracy Michelle Hunter

    2012-01-01

    The researcher employed two designs to address the research question for this particular study. This quasi-experimental non-equivalent control group study compared the math achievement of 92 eighth grade students who received Classroom Performance System (CPS)-based instruction using Peer Instruction (PI) to 76 eighth grade students who received…

  17. Education Watch: New Mexico. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares New Mexico's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how New Mexico is doing in narrowing the academic achievement gap between African American and Latino students and their white,…

  18. Understanding the Low Mathematics Achievement of Chilean Students: A Cross-National Analysis Using TIMSS Data

    ERIC Educational Resources Information Center

    Ramirez, Maria-Jose

    2006-01-01

    The low performance of Chile in the TIMSS 1998/99 international study of mathematics and science achievement was a great disappointment for that country. To investigate the likely causes for low performance in mathematics, this study (1) compared Chile to three countries and one large school system that had similar economic conditions but superior…

  19. Comparing Dichotomous and Trichotomous Approaches to Achievement Goal Theory: An Example Using Motivational Regulations as Outcome Variables

    ERIC Educational Resources Information Center

    Barkoukis, Vassilis; Ntoumanis, Nikos; Nikitaras, Nikitas

    2007-01-01

    Background: It is commonly assumed that there is conceptual equivalence between the task and ego achievement goals proposed by Nicholl's (1989) dichotomous achievement goal theory (Nicholls, 1989), and the mastery and performance approach goals advanced by Elliot's (1997) trichotomous hierarchical model of approach and avoidance achievement…

  20. The impact of attaining the Welsh Baccalaureate Advanced Diploma on academic performance in bioscience higher education

    NASA Astrophysics Data System (ADS)

    Yhnell, Emma; Wood, Heather; Baker, Mathew; Amici-Dargan, Sheila; Taylor, Chris; Randerson, Peter; Shore, Andrew

    2016-01-01

    Since the introduction of the Welsh Baccalaureate Advanced Diploma Qualification (WBQ) in 2003, an increasing number of students are applying to higher education institutions (HEIs) with this qualification. The advanced-level WBQ is regarded as equivalent to one General Certificate of Education A-Level (GCE A-Level). This study assesses the impact of attaining the WBQ in addition to three GCE A-Levels on overall university degree performance in comparison to attaining four GCE A-Levels, in three cohorts of undergraduate students (Year 1 = 318, Year 2 = 280, Year 3 = 236) studying Biosciences from 2005 to 2011 at a UK HEI. Binary logistic regression was used to compare the academic attainment of students who had achieved four GCE A-Levels to those who had achieved three GCE A-Levels in addition to the WBQ. Comparisons were also made between students who had achieved three GCE A-Levels and those who had achieved three GCE A-Levels in addition to the WBQ. The results suggest that students who achieved the WBQ qualification in its current form, in addition to three GCE A-Levels, performed less well academically in undergraduate studies than those who achieved four GCE A-Levels. Furthermore, this effect was still present when the balance between coursework and examination was considered, and when students who had achieved the WBQ in addition to three GCE A-Levels were compared to students who had achieved three GCE A-Levels.

  1. Comparing the Reading Performance of High-Achieving Adolescents: Computer-Based Testing versus Paper/Pencil

    ERIC Educational Resources Information Center

    Eno, Linda Peet

    2011-01-01

    Literacy is moving into the digital context. Many of the literacy tasks associated with higher education, the workplace, and civic life now take place in the digital world. Literacy in high school, however, languishes in the text world. This study compared the text literacy of a group of high-achieving 10th-grade students, to their digital…

  2. Working Memory Load and Reminder Effect on Event-Based Prospective Memory of High- and Low-Achieving Students in Math.

    PubMed

    Chen, Youzhen; Lian, Rong; Yang, Lixian; Liu, Jianrong; Meng, Yingfang

    The effects of working memory (WM) demand and reminders on an event-based prospective memory (PM) task were compared between students with low and high achievement in math. WM load (1- and 2-back tasks) was manipulated as a within-subject factor and reminder (with or without reminder) as a between-subject factor. Results showed that high-achieving students outperformed low-achieving students on all PM and n-back tasks. Use of a reminder improved PM performance and thus reduced prospective interference; the performance of ongoing tasks also improved for all students. Both PM and n-back performances in low WM load were better than in high WM load. High WM load had more influence on low-achieving students than on high-achieving students. Results suggest that low-achieving students in math were weak at PM and influenced more by high WM load. Thus, it is important to train these students to set up an obvious reminder for their PM and improve their WM.

  3. Using Valid and Invalid Experimental Designs to Teach the Control of Variables Strategy in Higher and Lower Achieving Classrooms

    ERIC Educational Resources Information Center

    Lorch, Robert F., Jr.; Lorch, Elizabeth P.; Freer, Benjamin Dunham; Dunlap, Emily E.; Hodell, Emily C.; Calderhead, William J.

    2014-01-01

    Students (n = 1,069) from 60 4th-grade classrooms were taught the control of variables strategy (CVS) for designing experiments. Half of the classrooms were in schools that performed well on a state-mandated test of science achievement, and half were in schools that performed relatively poorly. Three teaching interventions were compared: an…

  4. The Achievement Gap: Factors That Influenced the Achievement of Successful Black Students

    ERIC Educational Resources Information Center

    Morton, Kwame R., Sr.

    2011-01-01

    The academic underperformance of Black students when compared to their White peers has confounded educators nationwide. This discrepancy in academic performance commonly referred to as the achievement gap has become a national crisis which has led to one of the most significant educational reforms undertaken in the United States of America in the…

  5. Motivation and Mathematics Achievement: A Comparative Study of Asian-American, Caucasian-American, and East Asian High School Students.

    ERIC Educational Resources Information Center

    Chen, Chuansheng; Stevenson, Harold W.

    1995-01-01

    Examined academic achievement under a cultural motivational framework. Asian American students' performance in mathematics was found to be between that of Chinese and Japanese students and that of Caucasian Americans. Suggests that academic achievement reflects a cultural heritage that emphasizes education and the ability of all persons to benefit…

  6. High-Achieving and Average Students' Reading Growth: Contrasting School and Summer Trajectories

    ERIC Educational Resources Information Center

    Rambo-Hernandez, Karen E.; McCoach, D. Betsy

    2015-01-01

    Much is unknown about how initially high-achieving students grow academically, especially given the measurement issues inherent in assessing growth for the highest performing students. This study compared initially high-achieving and average students' growth in reading (in a cohort of third-grade students from 2,000 schools) over 3 years.…

  7. Professional Learning Communities: An Analysis of Teacher Participation in a PLC and the Relationship with Student Academic Achievement

    ERIC Educational Resources Information Center

    Aylsworth, Anthony James

    2012-01-01

    This study sought to compare teacher participation in a Professional Learning Community with the performance of their students. Student achievement data from multiple subject-alike groups were compared in a pre-and post-PLC format, using an independent, two-sample t-test. Overall, 10 PLCs from one high school in a suburban, Iowa setting were…

  8. A Comparative Study of Parental Involvement and Its Effect on African-American Male and Overall Student Achievement at Single Gender and Coeducational Middle Schools

    ERIC Educational Resources Information Center

    Nellums, Michael W.

    2011-01-01

    The purpose of this study was to determine if Parental Involvement influenced academic performance at single gender and co-educational schools. This study also compared African American male academic achievement with all students enrolled in two single gender, and one coeducational, middle school programs. Although all three schools reflected a…

  9. A Structural Model of Algebra Achievement: Computational Fluency and Spatial Visualisation as Mediators of the Effect of Working Memory on Algebra Achievement

    ERIC Educational Resources Information Center

    Tolar, Tammy Daun; Lederberg, Amy R.; Fletcher, Jack M.

    2009-01-01

    The goal of this study was to develop and evaluate a structural model of the relations among cognitive abilities and arithmetic skills and college students' algebra achievement. The model of algebra achievement was compared to a model of performance on the Scholastic Assessment in Mathematics (SAT-M) to determine whether the pattern of relations…

  10. Do achievement goals mediate stereotype threat?: an investigation on females' soccer performance.

    PubMed

    Chalabaev, Aina; Sarrazinr, Philippe; Stone, Jeff; Cury, François

    2008-04-01

    This research investigated stereotype threat effects on women's performance in sports and examined the mediation of this effect by achievement goals. The influence of two stereotypes-relative to the poor athletic ability and the poor technical soccer ability of women-were studied. Fifty-one female soccer players were randomly assigned to one of three conditions, introducing the task as diagnostic of athletic ability, technical soccer ability, or sports psychology. Next, they filled out a questionnaire measuring achievement goals and performed a soccer dribbling task. Results showed that compared with the control condition, females' performance significantly decreased in the athletic ability condition and tended to decrease in the technical soccer ability condition. Moreover, participants endorsed a performance-avoidance (relative to performance-approach) goal when the stereotypes were activated. However, this goal endorsement was not related to performance. The implications of these results for understanding the role of stereotypes in gender inequalities in sports are discussed.

  11. Attitudes of Middle School Students: Learning Online Compared to Face to Face

    ERIC Educational Resources Information Center

    Edwards, Clayton; Rule, Audrey

    2013-01-01

    Education in an online setting is an increasingly popular method of instruction. Previous studies comparing college or high school student performance in online and face-to-face courses found, in most cases, similar achievement between conditions. However, research is lacking regarding middle school students' academic performance and attitudes…

  12. Effect of intake swirl on the performance of single cylinder direct injection diesel engine

    NASA Astrophysics Data System (ADS)

    Sharma, Vinod Kumar; Mohan, Man; Mouli, Chandra

    2017-11-01

    In the present work, the effect of inlet manifold geometry and swirl intensity on the direct injection (DI) diesel engine performance was investigated experimentally. Modifications in inlet manifold geometry have been suggested to achieve optimized swirl for the better mixing of fuel with air. The intake swirl intensities of modified cylinder head were measured in swirl test rig at different valve lifts. Later, the overall performance of 435 CC DI diesel engine was measured using modified cylinder head. In addition, the performance of engine was compared for both modified and old cylinder head. For same operating conditions, the brake power and brake specific fuel consumption was improved by 6% and 7% respectively with modified cylinder head compared to old cylinder head. The maximum brake power of 9 HP was achieved for modified cylinder head. The results revealed that the intake swirl has great influence on engine performance.

  13. A Study Comparing the Academic Achievement of African American Male Students Enrolled in Two Types of Nontraditional High Schools

    ERIC Educational Resources Information Center

    Rutledge, Anthony B.

    2010-01-01

    This study examined the relationship of the achievement of African American male students enrolled in an early college high school to those enrolled in a performing arts high school. The Georgia High School Graduation Test (GHSGT) scores of the 11th-grade African American male students from an early college high school were compared to the GHSGT…

  14. The Effect of Information Analysis Automation Display Content on Human Judgment Performance in Noisy Environments.

    PubMed

    Bass, Ellen J; Baumgart, Leigh A; Shepley, Kathryn Klein

    2013-03-01

    Displaying both the strategy that information analysis automation employs to makes its judgments and variability in the task environment may improve human judgment performance, especially in cases where this variability impacts the judgment performance of the information analysis automation. This work investigated the contribution of providing either information analysis automation strategy information, task environment information, or both, on human judgment performance in a domain where noisy sensor data are used by both the human and the information analysis automation to make judgments. In a simplified air traffic conflict prediction experiment, 32 participants made probability of horizontal conflict judgments under different display content conditions. After being exposed to the information analysis automation, judgment achievement significantly improved for all participants as compared to judgments without any of the automation's information. Participants provided with additional display content pertaining to cue variability in the task environment had significantly higher aided judgment achievement compared to those provided with only the automation's judgment of a probability of conflict. When designing information analysis automation for environments where the automation's judgment achievement is impacted by noisy environmental data, it may be beneficial to show additional task environment information to the human judge in order to improve judgment performance.

  15. Simple CPR: A randomized, controlled trial of video self-instructional cardiopulmonary resuscitation training in an African American church congregation.

    PubMed

    Todd, K H; Heron, S L; Thompson, M; Dennis, R; O'Connor, J; Kellermann, A L

    1999-12-01

    Despite the proven efficacy of cardiopulmonary resuscitation (CPR), only a small fraction of the population knows how to perform it. As a result, rates of bystander CPR and rates of survival from cardiac arrest are low. Bystander CPR is particularly uncommon in the African American community. Successful development of a simplified approach to CPR training could boost rates of bystander CPR and save lives. We conducted the following randomized, controlled study to determine whether video self-instruction (VSI) in CPR results in comparable or better performance than traditional CPR training. This randomized, controlled trial was conducted among congregational volunteers in an African American church in Atlanta, GA. Subjects were randomly assigned to receive either 34 minutes of VSI or the 4-hour American Heart Association "Heartsaver" CPR course. Two months after training, blinded observers used explicit criteria to assess CPR performance in a simulated cardiac arrest setting. A recording manikin was used to measure ventilation and chest compression characteristics. Participants also completed a written test of CPR-related knowledge and attitudes. VSI trainees displayed a comparable level of performance to that achieved by traditional trainees. Observers scored 40% of VSI trainees competent or better in performing CPR, compared with only 16% of traditional trainees (absolute difference 24%, 95% confidence interval 8% to 40%). Data from the recording manikin confirmed these observations. VSI trainees and traditional trainees achieved comparable scores on tests of CPR-related knowledge and attitudes. Thirty-four minutes of VSI can produce CPR of comparable quality to that achieved by traditional training methods. VSI provides a simple, quick, consistent, and inexpensive alternative to traditional CPR instruction, and may be used to extend CPR training to historically underserved populations.

  16. A Longitudinal Study of Adenoma Detection Rate in Gastroenterology Fellowship Training.

    PubMed

    Gianotti, Robert J; Oza, Sveta Shah; Tapper, Elliot B; Kothari, Darshan; Sheth, Sunil G

    2016-10-01

    Current guidelines suggest that a gastroenterology fellow in training needs to perform 140 colonoscopies to achieve competency. Data are limited regarding adenoma detection rate (ADR) in fellowship. To assess how fellow ADR correlates with number of colonoscopies performed. We performed a retrospective study examining consecutive colonoscopies performed by gastroenterology fellows. Fellow ADR before and after the 140 procedure benchmark was compared to colonoscopies performed by attending only with whom these fellows trained. A threshold for ideal procedure count was performed using ROC analysis. We analyzed 2021 average-risk colonoscopies performed by 10 gastroenterology fellows under the supervision of an attending physician. When fellows had performed <140 colonoscopies, the ADR was 27 % compared with an ADR of 36 % when fellows had performed >140 colonoscopies under attending supervision (p = 0.02). The ADR of fellows who had performed >140 colonoscopies under attending supervision was greater than that of attending-only colonoscopies (36 vs. 25 %, p < 0.0001). A threshold of >325 (male patients) and 539 (female patients) colonoscopies was determined to be ideal for achieving adequate ADR based on ROC analysis. Our data suggest that ADR increases after fellows perform >140 colonoscopies under attending supervision, and thereafter surpasses the ADR of attending-only colonoscopies. Some of the differences may be driven by detection of small adenomas. The findings of this study suggest that a higher threshold for number of colonoscopies performed under attending supervision may be needed to achieve adequate ADR during fellowship prior to independent practice.

  17. Graders' Mathematics Achievement

    ERIC Educational Resources Information Center

    Bond, John B.; Ellis, Arthur K.

    2013-01-01

    The purpose of this experimental study was to investigate the effects of metacognitive reflective assessment instruction on student achievement in mathematics. The study compared the performance of 141 students who practiced reflective assessment strategies with students who did not. A posttest-only control group design was employed, and results…

  18. Palmprint authentication using multiple classifiers

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay; Zhang, David

    2004-08-01

    This paper investigates the performance improvement for palmprint authentication using multiple classifiers. The proposed methods on personal authentication using palmprints can be divided into three categories; appearance- , line -, and texture-based. A combination of these approaches can be used to achieve higher performance. We propose to simultaneously extract palmprint features from PCA, Line detectors and Gabor-filters and combine their corresponding matching scores. This paper also investigates the comparative performance of simple combination rules and the hybrid fusion strategy to achieve performance improvement. Our experimental results on the database of 100 users demonstrate the usefulness of such approach over those based on individual classifiers.

  19. Test results for rotordynamic coefficients of anti-swirl self-injection seals

    NASA Technical Reports Server (NTRS)

    Kim, C. H.; Lee, Y. B.

    1994-01-01

    Test results are presented for rotordynamic coefficients and leakage for three annular seals which use anti-swirl self-injection concept to yield significant improvement in whirl frequency ratios as compared to smooth and damper seals. A new anti-swirl self-inection mechanism is achieved by deliberately machining self-injection holes inside the seal stator mechanism which is used to achieve effective reduction of the tangential flow which is considered as a prime cause of rotor instability in high performance turbomachinery. Test results show that the self-injection mechanism significantly improves whirl frequency ratios; however, the leakage performance degrades due to the introduction of the self-injection mechanism. Through a series of the test program, an optimum anti-swirl self-injection seal which uses a labyrinth stator surface with anti-axial flow injections is selected to obtain a significant improvement in the whirl frequency ratio as compared to a damper seal, while showing moderate leakage performance. Best whirl frequency ratio is achieved by an anti-swirl self-injection seal of 12 holes anti-swirl and 6 degree anti-leakage injection with a labyrinth surface configuration. When compared to a damper seal, the optimum configuration outperforms the whirl frequency ratio by a factor of 2.

  20. Academic Achievement in Children With Oral Clefts Versus Unaffected Siblings

    PubMed Central

    Wehby, George L.; Barron, Sheila; Romitti, Paul A.; Ansley, Timothy N.; Speltz, Matthew L.

    2014-01-01

    Objective To compare academic achievement in children with oral-facial clefts (OFC) with their unaffected siblings. Methods 256 children with OFC were identified from the Iowa Registry for Congenital and Inherited Disorders, and 387 unaffected siblings were identified from birth certificates. These data were linked to Iowa Testing Programs achievement data. We compared academic achievement in children with OFC with their unaffected siblings using linear regression models, adjusted for potential confounders. In post hoc analyses, we explored modifiers of siblings’ academic performance. Results Achievement scores were similar between children with OFC and their siblings. Children with cleft palate only were significantly more likely to use special education than their unaffected siblings. Siblings’ academic achievement was inversely related to distance in birth order and age from the affected child. Conclusion Children with OFC and their siblings received similar achievement scores. Younger siblings, in particular, may share a vulnerability to poor academic outcomes. PMID:24993102

  1. Analysis of a virtual memory model for maintaining database views

    NASA Technical Reports Server (NTRS)

    Kinsley, Kathryn C.; Hughes, Charles E.

    1992-01-01

    This paper presents an analytical model for predicting the performance of a new support strategy for database views. This strategy, called the virtual method, is compared with traditional methods for supporting views. The analytical model's predictions of improved performance by the virtual method are then validated by comparing these results with those achieved in an experimental implementation.

  2. Mathematics deficits in adolescents with bipolar I disorder.

    PubMed

    Lagace, Diane C; Kutcher, Stanley P; Robertson, Heather A

    2003-01-01

    This study examined mathematical ability in adolescents with bipolar I disorder, compared to adolescents with major depressive disorder and psychiatrically healthy comparison subjects. Participants (N=119) included adolescents in remission from bipolar disorder (N=44) or major depressive disorder (N=30), as well as comparison subjects (N=45) with no psychiatric history. Participants were assessed with the following measures: the Wide-Range Achievement Test, Revised 2 (WRAT-R2), Peabody Individual Achievement Test, Bay Area Functional Performance Evaluation Task-Oriented Assessment (functional mathematics subtest), Test of Nonverbal Intellegence-2, and a self-report of mathematics performance. WRAT-R2 and Peabody Individual Achievement Test scores for spelling, mathematics, and reading revealed that adolescents with bipolar disorder had significantly lower achievement in mathematics, compared to subjects with major depressive disorder and comparison subjects. Results for the Test of Nonverbal Intellegence-2 were not significantly different between groups. Adolescents with bipolar disorder took significantly longer to complete the Bay Area Functional Performance Evaluation mathematics task. Significantly fewer adolescents with bipolar disorder (9%) reported above-average mathematics performance, compared with the other groups. Adolescents with remitted bipolar disorder have a specific profile of mathematics difficulties that differentiates them from both adolescents with unipolar depression and psychiatrically healthy comparison subjects. These mathematics deficits may not derive simply from more global deficits in nonverbal intelligence or executive functioning, but may be associated with neuroanatomical abnormalities that result in cognitive deficits, including a slowed response time. These deficits suggest the need for specialized assessment of mathematics as part of a comprehensive clinical follow-up treatment plan.

  3. Achievement Motivation Training and Executive Advancement

    ERIC Educational Resources Information Center

    Aronoff, Joel; Litwin, George H.

    1971-01-01

    Executives who were given a program designed to strengthen their need for achievement were matched with comparable executives chosen to attend the corporation's executive development course during approximately the same period. In a followup study, participants in the motivation training course had performed significantly better than their matched…

  4. Simulator training to automaticity leads to improved skill transfer compared with traditional proficiency-based training: a randomized controlled trial.

    PubMed

    Stefanidis, Dimitrios; Scerbo, Mark W; Montero, Paul N; Acker, Christina E; Smith, Warren D

    2012-01-01

    We hypothesized that novices will perform better in the operating room after simulator training to automaticity compared with traditional proficiency based training (current standard training paradigm). Simulator-acquired skill translates to the operating room, but the skill transfer is incomplete. Secondary task metrics reflect the ability of trainees to multitask (automaticity) and may improve performance assessment on simulators and skill transfer by indicating when learning is complete. Novices (N = 30) were enrolled in an IRB-approved, blinded, randomized, controlled trial. Participants were randomized into an intervention (n = 20) and a control (n = 10) group. The intervention group practiced on the FLS suturing task until they achieved expert levels of time and errors (proficiency), were tested on a live porcine fundoplication model, continued simulator training until they achieved expert levels on a visual spatial secondary task (automaticity) and were retested on the operating room (OR) model. The control group participated only during testing sessions. Performance scores were compared within and between groups during testing sessions. : Intervention group participants achieved proficiency after 54 ± 14 and automaticity after additional 109 ± 57 repetitions. Participants achieved better scores in the OR after automaticity training [345 (range, 0-537)] compared with after proficiency-based training [220 (range, 0-452; P < 0.001]. Simulator training to automaticity takes more time but is superior to proficiency-based training, as it leads to improved skill acquisition and transfer. Secondary task metrics that reflect trainee automaticity should be implemented during simulator training to improve learning and skill transfer.

  5. Cohort versus Non-Cohort High School Students' Math Performance: Achievement Test Scores and Coursework

    ERIC Educational Resources Information Center

    Parke, Carol S.; Keener, Dana

    2011-01-01

    The purpose of this study is to compare multiple measures of mathematics achievement for 1,378 cohort students who attended the same high school in a district from 9th to 12th grade with non-cohort students in each grade level. Results show that mobility had an impact on math achievement. After accounting for gender, ethnicity, and SES, adjusted…

  6. Eighth Grade Algebra Course Placement and Student Motivation for Mathematics

    PubMed Central

    Simzar, Rahila M.; Domina, Thurston; Tran, Cathy

    2016-01-01

    This study uses student panel data to examine the association between Algebra placement and student motivation for mathematics. Changes in achievement goals, expectancy, and task value for students in eighth grade Algebra are compared with those of peers placed in lower-level mathematics courses (N = 3,306). In our sample, students placed in Algebra reported an increase in performance-avoidance goals as well as decreases in academic self-efficacy and task value. These relations were attenuated for students who had high mathematics achievement prior to Algebra placement. Whereas all students reported an overall decline in performance-approach goals over the course of eighth grade, previously high-achieving students reported an increase in these goals. Lastly, previously high-achieving students reported an increase in mastery goals. These findings suggest that while previously high-achieving students may benefit motivationally from eighth grade Algebra placement, placing previously average- and low-performing students in Algebra can potentially undermine their motivation for mathematics. PMID:26942210

  7. Eighth Grade Algebra Course Placement and Student Motivation for Mathematics.

    PubMed

    Simzar, Rahila M; Domina, Thurston; Tran, Cathy

    2016-01-01

    This study uses student panel data to examine the association between Algebra placement and student motivation for mathematics. Changes in achievement goals, expectancy, and task value for students in eighth grade Algebra are compared with those of peers placed in lower-level mathematics courses (N = 3,306). In our sample, students placed in Algebra reported an increase in performance-avoidance goals as well as decreases in academic self-efficacy and task value. These relations were attenuated for students who had high mathematics achievement prior to Algebra placement. Whereas all students reported an overall decline in performance-approach goals over the course of eighth grade, previously high-achieving students reported an increase in these goals. Lastly, previously high-achieving students reported an increase in mastery goals. These findings suggest that while previously high-achieving students may benefit motivationally from eighth grade Algebra placement, placing previously average- and low-performing students in Algebra can potentially undermine their motivation for mathematics.

  8. The Effects of Privileging Moral or Performance Character Development in Urban Adolescents

    ERIC Educational Resources Information Center

    Seider, Scott; Novick, Sarah; Gomez, Jessica

    2013-01-01

    This study compared the effects of emphasizing moral character development or performance character development at three high-performing, high-poverty urban middle schools. Performance character consists of the qualities that allow individuals to regulate their thoughts and actions in ways that support achievement in a particular endeavor. Moral…

  9. Analysis of Student Performance on the Undergraduate Record Examinations (1973).

    ERIC Educational Resources Information Center

    Litwin, James L.

    This report examines the performance of students in the Modular Achievement Program (MAP) at Bowling Green State University using the Undergraduate Record Examinations (URE) as the primary criterion. The performances of students in MAP on the URE is delineated and compared to the performance of freshman and sophomore norm groups at Bowling Green…

  10. Performance Enhancement Using Selective Reinforcement for Metallic Single- and Multi-Pin Loaded Holes

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.; Seshadri, Banavara R.

    2005-01-01

    An analysis based investigation of aluminum with metal matrix composite selectively reinforced single- and multi-hole specimens was performed and their results compared with results from geometrically comparable non-reinforced specimens. All reinforced specimens exhibited a significant increase in performance. Performance increase of up to 170 percent was achieved. Specimen failure modes were consistent with results from reinforced polymeric matrix composite specimens. Localized reinforcement application (circular) proved as effective as a broader area (strip) reinforcement. Also, selective reinforcement is an excellent method of increasing the performance of multi-hole specimens.

  11. Comparing Interval Management Control Laws for Steady-State Errors and String Stability

    NASA Technical Reports Server (NTRS)

    Weitz, Lesley A.; Swieringa, Kurt A.

    2018-01-01

    Interval Management (IM) is a future airborne spacing concept that leverages avionics to provide speed guidance to an aircraft to achieve and maintain a specified spacing interval from another aircraft. The design of a speed control law to achieve the spacing goal is a key aspect in the research and development of the IM concept. In this paper, two control laws that are used in much of the contemporary IM research are analyzed and compared to characterize steady-state errors and string stability. Numerical results are used to illustrate how the choice of control laws gains impacts the size of steady-state errors and string performance and the potential trade-offs between those performance characteristics.

  12. The Effect of Information Analysis Automation Display Content on Human Judgment Performance in Noisy Environments

    PubMed Central

    Bass, Ellen J.; Baumgart, Leigh A.; Shepley, Kathryn Klein

    2014-01-01

    Displaying both the strategy that information analysis automation employs to makes its judgments and variability in the task environment may improve human judgment performance, especially in cases where this variability impacts the judgment performance of the information analysis automation. This work investigated the contribution of providing either information analysis automation strategy information, task environment information, or both, on human judgment performance in a domain where noisy sensor data are used by both the human and the information analysis automation to make judgments. In a simplified air traffic conflict prediction experiment, 32 participants made probability of horizontal conflict judgments under different display content conditions. After being exposed to the information analysis automation, judgment achievement significantly improved for all participants as compared to judgments without any of the automation's information. Participants provided with additional display content pertaining to cue variability in the task environment had significantly higher aided judgment achievement compared to those provided with only the automation's judgment of a probability of conflict. When designing information analysis automation for environments where the automation's judgment achievement is impacted by noisy environmental data, it may be beneficial to show additional task environment information to the human judge in order to improve judgment performance. PMID:24847184

  13. Toward a Model-Based Predictive Controller Design in Brain–Computer Interfaces

    PubMed Central

    Kamrunnahar, M.; Dias, N. S.; Schiff, S. J.

    2013-01-01

    A first step in designing a robust and optimal model-based predictive controller (MPC) for brain–computer interface (BCI) applications is presented in this article. An MPC has the potential to achieve improved BCI performance compared to the performance achieved by current ad hoc, nonmodel-based filter applications. The parameters in designing the controller were extracted as model-based features from motor imagery task-related human scalp electroencephalography. Although the parameters can be generated from any model-linear or non-linear, we here adopted a simple autoregressive model that has well-established applications in BCI task discriminations. It was shown that the parameters generated for the controller design can as well be used for motor imagery task discriminations with performance (with 8–23% task discrimination errors) comparable to the discrimination performance of the commonly used features such as frequency specific band powers and the AR model parameters directly used. An optimal MPC has significant implications for high performance BCI applications. PMID:21267657

  14. Toward a model-based predictive controller design in brain-computer interfaces.

    PubMed

    Kamrunnahar, M; Dias, N S; Schiff, S J

    2011-05-01

    A first step in designing a robust and optimal model-based predictive controller (MPC) for brain-computer interface (BCI) applications is presented in this article. An MPC has the potential to achieve improved BCI performance compared to the performance achieved by current ad hoc, nonmodel-based filter applications. The parameters in designing the controller were extracted as model-based features from motor imagery task-related human scalp electroencephalography. Although the parameters can be generated from any model-linear or non-linear, we here adopted a simple autoregressive model that has well-established applications in BCI task discriminations. It was shown that the parameters generated for the controller design can as well be used for motor imagery task discriminations with performance (with 8-23% task discrimination errors) comparable to the discrimination performance of the commonly used features such as frequency specific band powers and the AR model parameters directly used. An optimal MPC has significant implications for high performance BCI applications.

  15. An international comparison study of pharmacy students' achievement goals and their relationship to assessment type and scores.

    PubMed

    Alrakaf, Saleh; Anderson, Claire; Coulman, Sion A; John, Dai N; Tordoff, June; Sainsbury, Erica; Rose, Grenville; Smith, Lorraine

    2015-04-25

    To identify pharmacy students' preferred achievement goals in a multi-national undergraduate population, to investigate achievement goal preferences across comparable degree programs, and to identify relationships between achievement goals, academic performance, and assessment type. The Achievement Goal Questionnaire was administered to second year students in 4 universities in Australia, New Zealand, England, and Wales. Academic performance was measured using total scores, multiple-choice questions, and written answers (short essay). Four hundred eighty-six second year students participated. Students showed an overall preference for the mastery-approach goal orientation across all sites. The predicted relationships between goal orientation and multiple-choice questions, and written answers scores, were significant. This study is the first of its kind to examine pharmacy students' achievement goals at a multi-national level and to differentiate between assessment type and measures of achievement motivation. Students adopting a mastery-approach goal are more likely to gain high scores in assessments that measure understanding and depth of knowledge.

  16. An International Comparison Study of Pharmacy Students’ Achievement Goals and their Relationship to Assessment Type and Scores

    PubMed Central

    Anderson, Claire; Coulman, Sion A.; John, Dai N.; Tordoff, June; Sainsbury, Erica; Rose, Grenville; Smith, Lorraine

    2015-01-01

    Objective: To identify pharmacy students’ preferred achievement goals in a multi-national undergraduate population, to investigate achievement goal preferences across comparable degree programs, and to identify relationships between achievement goals, academic performance, and assessment type. Methods: The Achievement Goal Questionnaire was administered to second year students in 4 universities in Australia, New Zealand, England, and Wales. Academic performance was measured using total scores, multiple-choice questions, and written answers (short essay). Results: Four hundred eighty-six second year students participated. Students showed an overall preference for the mastery-approach goal orientation across all sites. The predicted relationships between goal orientation and multiple-choice questions, and written answers scores, were significant. Conclusion: This study is the first of its kind to examine pharmacy students’ achievement goals at a multi-national level and to differentiate between assessment type and measures of achievement motivation. Students adopting a mastery-approach goal are more likely to gain high scores in assessments that measure understanding and depth of knowledge. PMID:25995510

  17. SU-D-206-01: Employing a Novel Consensus Optimization Strategy to Achieve Iterative Cone Beam CT Reconstruction On a Multi-GPU Platform

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, B; Southern Medical University, Guangzhou, Guangdong; Tian, Z

    Purpose: While compressed sensing-based cone-beam CT (CBCT) iterative reconstruction techniques have demonstrated tremendous capability of reconstructing high-quality images from undersampled noisy data, its long computation time still hinders wide application in routine clinic. The purpose of this study is to develop a reconstruction framework that employs modern consensus optimization techniques to achieve CBCT reconstruction on a multi-GPU platform for improved computational efficiency. Methods: Total projection data were evenly distributed to multiple GPUs. Each GPU performed reconstruction using its own projection data with a conventional total variation regularization approach to ensure image quality. In addition, the solutions from GPUs were subjectmore » to a consistency constraint that they should be identical. We solved the optimization problem with all the constraints considered rigorously using an alternating direction method of multipliers (ADMM) algorithm. The reconstruction framework was implemented using OpenCL on a platform with two Nvidia GTX590 GPU cards, each with two GPUs. We studied the performance of our method and demonstrated its advantages through a simulation case with a NCAT phantom and an experimental case with a Catphan phantom. Result: Compared with the CBCT images reconstructed using conventional FDK method with full projection datasets, our proposed method achieved comparable image quality with about one third projection numbers. The computation time on the multi-GPU platform was ∼55 s and ∼ 35 s in the two cases respectively, achieving a speedup factor of ∼ 3.0 compared with single GPU reconstruction. Conclusion: We have developed a consensus ADMM-based CBCT reconstruction method which enabled performing reconstruction on a multi-GPU platform. The achieved efficiency made this method clinically attractive.« less

  18. [Teaching performance assessment in Public Health employing three different strategies].

    PubMed

    Martínez-González, Adrián; Moreno-Altamirano, Laura; Ponce-Rosas, Efrén Raúl; Martínez-Franco, Adrián Israel; Urrutia-Aguilar, María Esther

    2011-01-01

    The educational system depends upon the quality and performance of their faculty and should therefore be process of continuous improvement. To assess the teaching performance of the Public Health professors, at the Faculty of Medicine, UNAM through three strategies. Justification study. The evaluation was conducted under a mediational model through three strategies: students' opinion assessment, self-assessment and students' academic achievement. We applied descriptive statistics, Student t test, ANOVA and Pearson correlation. Twenty professors were evaluated from the Public Health department, representing 57% of all them who teach the subject. The professor's performance was highly valued self-assessment compared with assessment of student opinion, was confirmed by statistical analysis the difference was significant. The difference amongst the three evaluation strategies became more evident between self-assessment and the scores obtained by students in their academic achievement. The integration of these three strategies offers a more complete view of the teacher's performance quality. Academic achievement appears to be a more objective strategy for teaching performance assessment than students' opinion and self-assessment.

  19. Comparing Three Models of Achievement Goals: Goal Orientations, Goal Standards, and Goal Complexes

    ERIC Educational Resources Information Center

    Senko, Corwin; Tropiano, Katie L.

    2016-01-01

    Achievement goal theory (Dweck, 1986) initially characterized mastery goals and performance goals as opposites in a good-bad dualism of student motivation. A later revision (Harackiewicz, Barron, & Elliot, 1998) contended that both goals can provide benefits and be pursued together. Perhaps both frameworks are correct: Their contrasting views…

  20. The Impact of Written Comments on Student Achievement.

    ERIC Educational Resources Information Center

    Freeman, Donald J.; Niemeyer, Roger C.

    This study sought to determine if an instructor of a competency-based course who sets performance standards at a comparatively low level might facilitate higher levels of student achievement through the use of written comments on unit posttests. Eighty-eight students in a graduate education course were randomly assigned to one of four experimental…

  1. Effect of Blended Learning Environment Model on High School Students' Academic Achievement

    ERIC Educational Resources Information Center

    Kazu, Ibrahim Yasar; Demirkol, Mehmet

    2014-01-01

    This study analyzes the students' academic performance by comparing the blended learning environment and traditional learning environment. It has been observed whether there is a significant difference between the academic achievement grade dispersions and the male-female students' grades. The study has been carried out in Diyarbakir Anatolian…

  2. Effects of Computer Applications on Elementary School Students' Achievement: A Meta-Analysis of Students in Taiwan

    ERIC Educational Resources Information Center

    Liao, Yuen-kuang Cliff; Chang, Huei-wen; Chen, Yu-wen

    2008-01-01

    A meta-analysis was performed to synthesize existing research comparing the effects of computer applications (i.e., computer-assisted instruction, computer simulations, and Web-based learning) versus traditional instruction on elementary school students' achievement in Taiwan. Forty-eight studies were located from four sources, and their…

  3. Performance in an Online Introductory Course in a Hybrid Classroom Setting

    ERIC Educational Resources Information Center

    Aly, Ibrahim

    2013-01-01

    This study compared the academic achievement between undergraduate students taking an introductory managerial accounting course online (N = 104) and students who took the same course in a hybrid classroom setting (N = 203). Student achievement was measured using scores from twelve weekly online assignments, two major online assignments, a final…

  4. Are training and transfer effects of working memory updating training modulated by achievement motivation?

    PubMed

    Zhao, Xin; Xu, Yiwenjie; Fu, Junjun; Maes, Joseph H R

    2018-04-01

    Previous studies examining effects of working memory (WM) updating training revealed mixed results. One factor that might modulate training gains, and possibly also transfer of those gains to non-trained cognitive tasks, is achievement motivation. In the present Studies 1 and 2, students with either a high (HAM) or low (LAM) achievement motivation completed a 14-day visuospatial WM updating training program. In Study 2, the students also performed a set of tasks measuring other executive functions and fluid intelligence prior to and after training. In both studies, the HAM students displayed a larger training gain than the LAM students. Study 2 revealed that after training, both groups showed better performance on the near-transfer but not far-transfer tasks. Importantly, the differential training gain was not associated with better post-training performance for the HAM compared to the LAM students on any of the transfer tasks. These results are taken to support a modulatory role of achievement motivation on WM training benefits, but not on transfer of those benefits to other tasks. Possible reasons for the general improvement on the near-transfer tasks and the absence of a modulatory role of achievement motivation on transfer-task performance are discussed.

  5. Factors affecting scholastic performances of adolescents.

    PubMed

    Shashidhar, Saraswati; Rao, Chandrika; Hegde, Radhakrishna

    2009-05-01

    The present study aims at recognizing the social influence, study habits and health factors affecting scholastic performances of adolescents and to compare these factors among the adolescents between two categories of school. A total of 1230 adolescents (13-18 yrs) were screened. Data was collected by personal interview, using the teenage screening questionnaire, Trivandrum, between May 2004 and November 2005. A total 615 students from corporation and private schools were studied. 39.76% (489) were high achievers, 13.5% (166) were low achievers with p < 0.001. In the low achievers, 12.03% were from the corporation schools and 1.46% from private schools. The incidence of poor study habits and social factors were increased in low achievers of corporation schools. On multivariate analysis, the predictor variables for poor scholastic performance were adolescent having refractory error, not having help for study at home, not doing home work regularly, not solving question bank papers and reading only before examinations. It is feasible and worthwhile to identify the determinants of scholastic performance and plan intervention strategies at each school. The results of this study highlight the importance of implementing newer strategies, focusing on strict study patterns and creating the conducive school and home environment for study, so as to achieve better scholastic performances.

  6. Achievement goals, self-handicapping, and performance: a 2 x 2 achievement goal perspective.

    PubMed

    Ntoumanis, Nikos; Thøgersen-Ntoumani, Cecilie; Smith, Alison L

    2009-11-01

    Elliot and colleagues (2006) examined the effects of experimentally induced achievement goals, proposed by the trichotomous model, on self-handicapping and performance in physical education. Our study replicated and extended the work of Elliot et al. by experimentally promoting all four goals proposed by the 2 x 2 model (Elliot & McGregor, 2001), measuring the participants' own situational achievement goals, using a relatively novel task, and testing the participants in a group setting. We used a randomized experimental design with four conditions that aimed to induce one of the four goals advanced by the 2 x 2 model. The participants (n = 138) were undergraduates who engaged in a dart-throwing task. The results pertaining to self-handicapping partly replicated Elliot and colleagues' findings by showing that experimentally promoted performance-avoidance goals resulted in less practice. In contrast, the promotion of mastery-avoidance goals did not result in less practice compared with either of the approach goals. Dart-throwing performance did not differ among the four goal conditions. Personal achievement goals did not moderate the effects of experimentally induced goals on self-handicapping and performance. The extent to which mastery-avoidance goals are maladaptive is discussed, as well as the interplay between personal and experimentally induced goals.

  7. Paying the right price for pharmaceuticals: a case study of why the comparator matters.

    PubMed

    Spinks, Jean M; Richardson, Jeff R J

    2011-08-01

    This article considers the pricing policy for pharmaceuticals in Australia, which is widely seen as having achieved low drug prices. However, compared to New Zealand, the evidence implies that Australia might have improved its performance significantly if it had proactively sought market best pricing. The Australian record suggests that the information sought by authorities may not be sufficient for optimal pricing and that the economic evaluation of pharmaceuticals may be neither necessary nor sufficient for achieving this goal.

  8. A Fast and Scalable Algorithm for Calculating the Achievable Capacity of a Wireless Mesh Network

    DTIC Science & Technology

    2016-04-10

    to interference from a given transmission . We then use our algorithm to perform a network capacity analysis comparing different wireless technologies...A Fast and Scalable Algorithm for Calculating the Achievable Capacity of a Wireless Mesh Network Greg Kuperman, Jun Sun, and Aradhana Narula-Tam MIT...the maximum achievable capacity of a multi-hop wireless mesh network subject to interference constraints. Being able to quickly determine the maximum

  9. U.S. Math Performance in Global Perspective: How Well Does Each State Do at Producing High-Achieving Students? PEPG Report No.: 10-19

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Peterson, Paul E.; Woessmann, Ludger

    2010-01-01

    To see how well U.S. schools do at producing high-achieving math students, the authors compare the percentage of U.S. public and private school students in the graduating Class of 2009 who were highly accomplished in mathematics in each of the 50 states and in 10 urban districts to percentages of high achievers in 56 other countries. Their…

  10. Minimalist ensemble algorithms for genome-wide protein localization prediction.

    PubMed

    Lin, Jhih-Rong; Mondal, Ananda Mohan; Liu, Rong; Hu, Jianjun

    2012-07-03

    Computational prediction of protein subcellular localization can greatly help to elucidate its functions. Despite the existence of dozens of protein localization prediction algorithms, the prediction accuracy and coverage are still low. Several ensemble algorithms have been proposed to improve the prediction performance, which usually include as many as 10 or more individual localization algorithms. However, their performance is still limited by the running complexity and redundancy among individual prediction algorithms. This paper proposed a novel method for rational design of minimalist ensemble algorithms for practical genome-wide protein subcellular localization prediction. The algorithm is based on combining a feature selection based filter and a logistic regression classifier. Using a novel concept of contribution scores, we analyzed issues of algorithm redundancy, consensus mistakes, and algorithm complementarity in designing ensemble algorithms. We applied the proposed minimalist logistic regression (LR) ensemble algorithm to two genome-wide datasets of Yeast and Human and compared its performance with current ensemble algorithms. Experimental results showed that the minimalist ensemble algorithm can achieve high prediction accuracy with only 1/3 to 1/2 of individual predictors of current ensemble algorithms, which greatly reduces computational complexity and running time. It was found that the high performance ensemble algorithms are usually composed of the predictors that together cover most of available features. Compared to the best individual predictor, our ensemble algorithm improved the prediction accuracy from AUC score of 0.558 to 0.707 for the Yeast dataset and from 0.628 to 0.646 for the Human dataset. Compared with popular weighted voting based ensemble algorithms, our classifier-based ensemble algorithms achieved much better performance without suffering from inclusion of too many individual predictors. We proposed a method for rational design of minimalist ensemble algorithms using feature selection and classifiers. The proposed minimalist ensemble algorithm based on logistic regression can achieve equal or better prediction performance while using only half or one-third of individual predictors compared to other ensemble algorithms. The results also suggested that meta-predictors that take advantage of a variety of features by combining individual predictors tend to achieve the best performance. The LR ensemble server and related benchmark datasets are available at http://mleg.cse.sc.edu/LRensemble/cgi-bin/predict.cgi.

  11. Minimalist ensemble algorithms for genome-wide protein localization prediction

    PubMed Central

    2012-01-01

    Background Computational prediction of protein subcellular localization can greatly help to elucidate its functions. Despite the existence of dozens of protein localization prediction algorithms, the prediction accuracy and coverage are still low. Several ensemble algorithms have been proposed to improve the prediction performance, which usually include as many as 10 or more individual localization algorithms. However, their performance is still limited by the running complexity and redundancy among individual prediction algorithms. Results This paper proposed a novel method for rational design of minimalist ensemble algorithms for practical genome-wide protein subcellular localization prediction. The algorithm is based on combining a feature selection based filter and a logistic regression classifier. Using a novel concept of contribution scores, we analyzed issues of algorithm redundancy, consensus mistakes, and algorithm complementarity in designing ensemble algorithms. We applied the proposed minimalist logistic regression (LR) ensemble algorithm to two genome-wide datasets of Yeast and Human and compared its performance with current ensemble algorithms. Experimental results showed that the minimalist ensemble algorithm can achieve high prediction accuracy with only 1/3 to 1/2 of individual predictors of current ensemble algorithms, which greatly reduces computational complexity and running time. It was found that the high performance ensemble algorithms are usually composed of the predictors that together cover most of available features. Compared to the best individual predictor, our ensemble algorithm improved the prediction accuracy from AUC score of 0.558 to 0.707 for the Yeast dataset and from 0.628 to 0.646 for the Human dataset. Compared with popular weighted voting based ensemble algorithms, our classifier-based ensemble algorithms achieved much better performance without suffering from inclusion of too many individual predictors. Conclusions We proposed a method for rational design of minimalist ensemble algorithms using feature selection and classifiers. The proposed minimalist ensemble algorithm based on logistic regression can achieve equal or better prediction performance while using only half or one-third of individual predictors compared to other ensemble algorithms. The results also suggested that meta-predictors that take advantage of a variety of features by combining individual predictors tend to achieve the best performance. The LR ensemble server and related benchmark datasets are available at http://mleg.cse.sc.edu/LRensemble/cgi-bin/predict.cgi. PMID:22759391

  12. A Comparison of the School Performance of Sexually Abused, Neglected and Non-Maltreated Children.

    ERIC Educational Resources Information Center

    Reyome, Nancy Dodge

    1993-01-01

    Compared the school performance of sexually abused children and neglected children with the performance of two matched groups of nonmaltreated children, those from lower middle class families and from families receiving public assistance. Analyses of children's behavior ratings and school achievement indicated marked cognitive and behavioral…

  13. Velocity & displacement-dependent damper: A novel passive shock absorber inspired by the semi-active control

    NASA Astrophysics Data System (ADS)

    Nie, Shida; Zhuang, Ye; Wang, Yong; Guo, Konghui

    2018-01-01

    The performance of velocity & displacement-dependent damper (VDD), inspired by the semi-active control, is analyzed. The main differences among passive, displacement-dependent and semi-active dampers are compared on their damping properties. Valve assemblies of VDD are modelled to get an insight into its working principle. The mechanical structure composed by four valve assemblies helps to enable VDD to approach the performance by those semi-active control dampers. The valve structure parameters are determined by the suggested two-step process. Hydraulic model of the damper is built with AMEsim. Simulation result of F-V curves, which is similar to those of semi-active control damper, demonstrates that VDD could achieve the similar performance of semi-active control damper. The performance of a quarter vehicle model employing VDD is analyzed and compared with semi-active suspension. Simulation results show that VDD could perform as good as a semi-active control damper. In addition, no add-on hardware or energy consumption is needed for VDD to achieve the remarkable performance.

  14. 20 CFR 658.601 - State agency responsibility.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Cost Accounting Reports shall be compared to planned levels. Variances between achievement and plan... district office, a report describing local office performance within the area or district jurisdiction... System (ESARS) tables and Cost Accounting Reports shall be compared to planned levels. Variances between...

  15. 20 CFR 658.601 - State agency responsibility.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Cost Accounting Reports shall be compared to planned levels. Variances between achievement and plan... district office, a report describing local office performance within the area or district jurisdiction... System (ESARS) tables and Cost Accounting Reports shall be compared to planned levels. Variances between...

  16. 20 CFR 658.601 - State agency responsibility.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Cost Accounting Reports shall be compared to planned levels. Variances between achievement and plan... district office, a report describing local office performance within the area or district jurisdiction... System (ESARS) tables and Cost Accounting Reports shall be compared to planned levels. Variances between...

  17. COMPARATIVE ASSESSMENT OF BASELINE GASOLINE AND OXYFUELS

    EPA Science Inventory

    Despite the ubiquity of gasoline for several decades and more recent modifications in fuel formulations to achieve “cleaner” gasoline, a quantitative comparative assessment of the health risks related to these fuels remains to be performed. Under authority of Clean Air Act secti...

  18. Correlates of Achieving the Guidelines of Four Forms of Physical Activity, and the Relationship between Guidelines Achievement and Academic Performance: Undergraduate Students in Finland.

    PubMed

    El Ansari, Walid; Suominen, Sakari; Draper, Steve

    2017-06-01

    We surveyed and compared, by gender, the levels and correlates of achieving the international guidelines of four forms of physical activity (PA): moderate PA (MPA), vigorous PA (VPA), moderate or vigorous PA (MVPA), and muscle strengthening PA (MSPA). The study assessed the associations between achieving the guidelines of the four PA forms and a range of socio-demographic, health and academic performance variables. Data was collected across the seven faculties of the University of Turku (2013-2014 from a representative sample of 1,189 undergraduates). An English language online self-administered questionnaire assessed frequency and duration of PA/week for each form of PA. We employed cut-offs for the guidelines in accordance with the American Heart Association. Chi-square statistic tested the differences in PA, socio-demographic variables and academic performance between males and females. Binary logistic regression examined the factors associated with achieving the four PA guidelines and linear regression examined the association between the frequency of PA and academic performance. Achievement of PA guidelines was relatively low across the sample. Female students were less likely to achieve the VPA or MSPA guidelines, but were more health conscious and in generally exhibited better academic performace than males. High health awareness and excellent/very good self-rated health were the strongest predictors of achieving all forms of PA. Parents' education level was positively related to likelihood of achieving the VPA, MVPA and MSPA guidelines. Achieving the MPA guidelines (but not VPA or MSPA) was positively associated with subjective perceptions of better academic performance. Achievement of PA guidelines was generally low for this sample of Finnish students, and was associated with positive health status and high health awareness. Universities need a holistic approach to improve awareness of health and promote PA in students' lifestyles. Copyright© by the National Institute of Public Health, Prague 2017

  19. Daily online testing in large classes: boosting college performance while reducing achievement gaps.

    PubMed

    Pennebaker, James W; Gosling, Samuel D; Ferrell, Jason D

    2013-01-01

    An in-class computer-based system, that included daily online testing, was introduced to two large university classes. We examined subsequent improvements in academic performance and reductions in the achievement gaps between lower- and upper-middle class students in academic performance. Students (N = 901) brought laptop computers to classes and took daily quizzes that provided immediate and personalized feedback. Student performance was compared with the same data for traditional classes taught previously by the same instructors (N = 935). Exam performance was approximately half a letter grade above previous semesters, based on comparisons of identical questions asked from earlier years. Students in the experimental classes performed better in other classes, both in the semester they took the course and in subsequent semester classes. The new system resulted in a 50% reduction in the achievement gap as measured by grades among students of different social classes. These findings suggest that frequent consequential quizzing should be used routinely in large lecture courses to improve performance in class and in other concurrent and subsequent courses.

  20. Comparative Effects of Two Modes of Computer-Assisted Instructional Package on Solid Geometry Achievement

    ERIC Educational Resources Information Center

    Gambari, Isiaka Amosa; Ezenwa, Victoria Ifeoma; Anyanwu, Romanus Chogozie

    2014-01-01

    The study examined the effects of two modes of computer-assisted instructional package on solid geometry achievement amongst senior secondary school students in Minna, Niger State, Nigeria. Also, the influence of gender on the performance of students exposed to CAI(AT) and CAI(AN) packages were examined. This study adopted a pretest-posttest…

  1. A Framework for Understanding Cross-National and Cross-Ethnic Gaps in Math and Science Achievement: The Case of the United States

    ERIC Educational Resources Information Center

    Guglielmi, R. Sergio; Brekke, Nancy

    2017-01-01

    Comparative international assessments of academic achievement consistently indicate that US students trail behind many peers, particularly those from east Asia, in math and science. Traditional efforts to explain this finding have focused on identifying characteristics that might differentiate the United States from top-performing countries.…

  2. Acute Exercise and Academic Achievement in High School Youth

    ERIC Educational Resources Information Center

    Harveson, Andrew; Hannon, James; Brusseau, Timothy; Podlog, Les; Chase, Ben; Kang, Kyoung-doo

    2018-01-01

    The purpose of this study was to compare the acute effects of Aerobic Exercise (AE), Resistance Exercise (RE), and a nonexercise (NE) control on measures of academic achievement (AA) and cognition in 10th grade males and females. This study utilized a randomized crossover design. Tenth grade males and females performed three exercise trials (AE,…

  3. Staying with the Text: The Contribution of Gender, Achievement Orientations, and Interest to Students' Performance on a Literacy Task

    ERIC Educational Resources Information Center

    Graham, Jedda; Tisher, Ruth; Ainley, Mary; Kennedy, Gregor

    2008-01-01

    This study addresses concerns about boys' underperformance on literacy tasks compared to girls, by investigating male and females students' responses to narrative texts. Participants were 142 Grade 9 and 10 students. Achievement orientations, including goals, self-efficacy, and self-handicapping, were measured and approach and avoidance factors…

  4. Comparing the Effect of Two Types of Computer Screen Background Lighting on Students' Reading Engagement and Achievement

    ERIC Educational Resources Information Center

    Botello, Jennifer A.

    2014-01-01

    With increased dependence on computer-based standardized tests to assess academic achievement, technological literacy has become an essential skill. Yet, because students have unequal access to technology, they may not have equal opportunities to perform well on these computer-based tests. The researcher had observed students taking the STAR…

  5. The Effects of Socio-Economic Status on Prospective English Language Teachers' Academic Achievement

    ERIC Educational Resources Information Center

    Koban Koç, Didem

    2016-01-01

    Socioeconomic status (SES), which generally involves factors such as parental educational background, occupation and income level, is a strong predictor of student achievement. That is, students with higher parental SES demonstrate increased academic performance when compared to those with lower parental SES. The purpose of the present study is to…

  6. Academic Achievement and Transcendental Meditation: A Study with At-Risk Urban Middle School Students

    ERIC Educational Resources Information Center

    Nidich, Sanford; Mjasiri, Shujaa; Nidich, Randi; Rainforth, Maxwell; Grant, James; Valosek, Laurent; Chang, Walter; Zigler, Ronald L.

    2011-01-01

    The middle school level is of particular concern to educators because of poor standardized test performance. This study evaluated change in academic achievement in public middle school students practicing the Transcendental Meditation[R] program compared to controls. A total of 189 students who were below proficiency level at baseline in English…

  7. Performance on large-scale science tests: Item attributes that may impact achievement scores

    NASA Astrophysics Data System (ADS)

    Gordon, Janet Victoria

    Significant differences in achievement among ethnic groups persist on the eighth-grade science Washington Assessment of Student Learning (WASL). The WASL measures academic performance in science using both scenario and stand-alone question types. Previous research suggests that presenting target items connected to an authentic context, like scenario question types, can increase science achievement scores especially in underrepresented groups and thus help to close the achievement gap. The purpose of this study was to identify significant differences in performance between gender and ethnic subgroups by question type on the 2005 eighth-grade science WASL. MANOVA and ANOVA were used to examine relationships between gender and ethnic subgroups as independent variables with achievement scores on scenario and stand-alone question types as dependent variables. MANOVA revealed no significant effects for gender, suggesting that the 2005 eighth-grade science WASL was gender neutral. However, there were significant effects for ethnicity. ANOVA revealed significant effects for ethnicity and ethnicity by gender interaction in both question types. Effect sizes were negligible for the ethnicity by gender interaction. Large effect sizes between ethnicities on scenario question types became moderate to small effect sizes on stand-alone question types. This indicates the score advantage the higher performing subgroups had over the lower performing subgroups was not as large on stand-alone question types compared to scenario question types. A further comparison examined performance on multiple-choice items only within both question types. Similar achievement patterns between ethnicities emerged; however, achievement patterns between genders changed in boys' favor. Scenario question types appeared to register differences between ethnic groups to a greater degree than stand-alone question types. These differences may be attributable to individual differences in cognition, characteristics of test items themselves and/or opportunities to learn. Suggestions for future research are made.

  8. Boosting drug named entity recognition using an aggregate classifier.

    PubMed

    Korkontzelos, Ioannis; Piliouras, Dimitrios; Dowsey, Andrew W; Ananiadou, Sophia

    2015-10-01

    Drug named entity recognition (NER) is a critical step for complex biomedical NLP tasks such as the extraction of pharmacogenomic, pharmacodynamic and pharmacokinetic parameters. Large quantities of high quality training data are almost always a prerequisite for employing supervised machine-learning techniques to achieve high classification performance. However, the human labour needed to produce and maintain such resources is a significant limitation. In this study, we improve the performance of drug NER without relying exclusively on manual annotations. We perform drug NER using either a small gold-standard corpus (120 abstracts) or no corpus at all. In our approach, we develop a voting system to combine a number of heterogeneous models, based on dictionary knowledge, gold-standard corpora and silver annotations, to enhance performance. To improve recall, we employed genetic programming to evolve 11 regular-expression patterns that capture common drug suffixes and used them as an extra means for recognition. Our approach uses a dictionary of drug names, i.e. DrugBank, a small manually annotated corpus, i.e. the pharmacokinetic corpus, and a part of the UKPMC database, as raw biomedical text. Gold-standard and silver annotated data are used to train maximum entropy and multinomial logistic regression classifiers. Aggregating drug NER methods, based on gold-standard annotations, dictionary knowledge and patterns, improved the performance on models trained on gold-standard annotations, only, achieving a maximum F-score of 95%. In addition, combining models trained on silver annotations, dictionary knowledge and patterns are shown to achieve comparable performance to models trained exclusively on gold-standard data. The main reason appears to be the morphological similarities shared among drug names. We conclude that gold-standard data are not a hard requirement for drug NER. Combining heterogeneous models build on dictionary knowledge can achieve similar or comparable classification performance with that of the best performing model trained on gold-standard annotations. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  9. A Two-Minute Paper-and-Pencil Test of Symbolic and Nonsymbolic Numerical Magnitude Processing Explains Variability in Primary School Children's Arithmetic Competence

    PubMed Central

    Nosworthy, Nadia; Bugden, Stephanie; Archibald, Lisa; Evans, Barrie; Ansari, Daniel

    2013-01-01

    Recently, there has been a growing emphasis on basic number processing competencies (such as the ability to judge which of two numbers is larger) and their role in predicting individual differences in school-relevant math achievement. Children’s ability to compare both symbolic (e.g. Arabic numerals) and nonsymbolic (e.g. dot arrays) magnitudes has been found to correlate with their math achievement. The available evidence, however, has focused on computerized paradigms, which may not always be suitable for universal, quick application in the classroom. Furthermore, it is currently unclear whether both symbolic and nonsymbolic magnitude comparison are related to children’s performance on tests of arithmetic competence and whether either of these factors relate to arithmetic achievement over and above other factors such as working memory and reading ability. In order to address these outstanding issues, we designed a quick (2 minute) paper-and-pencil tool to assess children’s ability to compare symbolic and nonsymbolic numerical magnitudes and assessed the degree to which performance on this measure explains individual differences in achievement. Children were required to cross out the larger of two, single-digit numerical magnitudes under time constraints. Results from a group of 160 children from grades 1–3 revealed that both symbolic and nonsymbolic number comparison accuracy were related to individual differences in arithmetic achievement. However, only symbolic number comparison performance accounted for unique variance in arithmetic achievement. The theoretical and practical implications of these findings are discussed which include the use of this measure as a possible tool for identifying students at risk for future difficulties in mathematics. PMID:23844126

  10. Reducing the socio-economic status achievement gap at University by promoting mastery-oriented assessment.

    PubMed

    Smeding, Annique; Darnon, Céline; Souchal, Carine; Toczek-Capelle, Marie-Christine; Butera, Fabrizio

    2013-01-01

    In spite of official intentions to reduce inequalities at University, students' socio-economic status (SES) is still a major determinant of academic success. The literature on the dual function of University suggests that University serves not only an educational function (i.e., to improve students' learning), but also a selection function (i.e., to compare people, and orient them towards different positions in society). Because current assessment practices focus on the selection more than on the educational function, their characteristics fit better with norms and values shared by dominant high-status groups and may favour high-SES students over low-SES students in terms of performances. A focus on the educational function (i.e., mastery goals), instead, may support low-SES students' achievement, but empirical evidence is currently lacking. The present research set out to provide such evidence and tested, in two field studies and a randomised field experiment, the hypothesis that focusing on University's educational function rather than on its selection function may reduce the SES achievement gap. Results showed that a focus on learning, mastery-oriented goals in the assessment process reduced the SES achievement gap at University. For the first time, empirical data support the idea that low-SES students can perform as well as high-SES students if they are led to understand assessment as part of the learning process, a way to reach mastery goals, rather than as a way to compare students to each other and select the best of them, resulting in performance goals. This research thus provides a theoretical framework to understand the differential effects of assessment on the achievement of high and low-SES students, and paves the way toward the implementation of novel, theory-driven interventions to reduce the SES-based achievement gap at University.

  11. Regional Educational Performance Patterns in Europe

    ERIC Educational Resources Information Center

    Radó, Péter

    2011-01-01

    The paper aims to contribute to the assessment of the contextual relevance of various educational policies through an analysis of three aspects of the performance profiles of European countries: participation, the quality of learning outcomes and the equity of learning outcomes. Comparative analysis of international student achievement assessment…

  12. Immunization in India 1993-1999: wealth, gender, and regional inequalities revisited.

    PubMed

    Gaudin, Sylvestre; Yazbeck, Abdo S

    2006-02-01

    Previously published evidence from the 1992-1993 Indian National Family and Health Survey (NFHS) on the state of childhood immunization showed the importance of analyzing immunization outcomes beyond national averages. Reported total system failure (no immunization for all) in some low performance areas suggested that improvements in immunization levels may come with a worsening of the distribution of immunization based on wealth. In this paper, using the second wave of the NFHS (1998-1999), we take a new snapshot of the situation and compare it to 1992-1993, focusing on heterogeneities between states, rural-urban differentials, gender differentials, and more specifically on wealth-related inequalities. To assess whether improvements in overall immunization rates (levels) were accompanied by distributional improvements, or conversely, whether inequalities were reduced at the expense of overall achievement, we use a recently developed methodology to calculate an inequality-adjusted achievement index that captures performance both in terms of efficiency (change in levels) and equity (distribution by wealth quintiles) for each of the 17 largest Indian states. Comparing 1992-1993 to 1998-1999 achievements using different degrees of "inequality aversion" provides no evidence that distributional improvements occur at the expense of overall performance.

  13. From SPOT 5 to Pleiades HR: evolution of the instrumental specifications

    NASA Astrophysics Data System (ADS)

    Rosak, A.; Latry, C.; Pascal, V.; Laubier, D.

    2017-11-01

    Image quality specifications should aimed to fulfil high resolution mission requirements of remote sensing satellites with a minimum cost. The most important trade-off to be taken into account is between Modulation Transfer Function, radiometric noise and sampling scheme. This compromise is the main driver during design optimisation and requirement definition in order to achieve good performances and to minimise the mission cost. For the SPOT 5 satellite, a new compromise had been chosen. The supermode principle of imagery (sampling at 2.5 meter with a pixel size of 5 meter) imp roves the resolution by a factor of four compared with the SPOT 4 satellite (10 meter resolution). This paper presents the image quality specifications of the HRG-SPOT 5 instrument. We introduce all the efforts made on the instrument to achieve good image quality and low radiometric noise, then we compare the results with the SPOT 4 instrument's performances to highlight the improvements achieved. Then, the in-orbit performance will be described. Finally, we will present the new goals of image quality specifications for the new Pleiades-HR satellite for earth observation (0.7 meter resolution) and the instrument concept.

  14. UK Renal Registry 16th annual report: chapter 12 biochemical variables amongst UK adult dialysis patients in 2012: national and centre-specific analyses.

    PubMed

    Nicholas, Johann; Shaw, Catriona; Pitcher, David; Dawnay, Anne

    2013-01-01

    The UK Renal Association clinical practice guidelines include clinical performance measures for biochemical variables in dialysis patients. The UK Renal Registry (UKRR) annually audits dialysis centre performance against these measures as part of its role in promoting continuous quality improvement. Cross sectional performance analyses were undertaken to compare dialysis centre achievement of clinical audit measures for prevalent haemodialysis (HD) and peritoneal dialysis (PD) cohorts in 2012. The biochemical variables studied were phosphate, adjusted calcium, parathyroid hormone, bicarbonate and total cholesterol. In addition, longitudinal analyses were performed (2002-2012) to show changes in achievement of clinical performance measures over time. Fifty-six percent of HD and 61% of PD patients achieved a phosphate within the range recommended by the RA clinical practice guidelines. Seventy-seven percent of HD and 78% of PD patients had adjusted calcium between 2.2-2.5 mmol/L. Fifty-eight percent of HD and 65% of PD patients had parathyroid hormone between 16-72 pmol/L. Fifty-nine percent of HD and 80% of PD patients achieved the audit measure for bicarbonate. There was significant inter-centre variation for all variables studied. The UKRR consistently demonstrates significant inter-centre variation in achievement of biochemical clinical audit measures. Understanding the causes of this variation is an important part of improving the care of dialysis patients in the UK.

  15. Chapter 9 Biochemical variables amongst UK adult dialysis patients in 2010: national and centre-specific analyses.

    PubMed

    Pruthi, Rishi; Pitcher, David; Dawnay, Anne

    2012-01-01

    The UK Renal Association clinical practice guidelines include clinical performance measures for biochemical variables in dialysis patients. The UK Renal Registry (UKRR) annually audits dialysis centre performance against these measures as part of its role in promoting continuous quality improvement. Cross sectional performance analyses were undertaken to compare dialysis centre achievement of clinical audit measures for prevalent haemodialysis (HD) and peritoneal dialysis (PD) cohorts in 2010. The biochemical variables studied were phosphate, adjusted calcium, parathyroid hormone, bicarbonate and total cholesterol. In addition longitudinal analyses were performed (2000-2010) to show changes in achievement of clinical performance measures over time. Fifty-six percent of HD and 69% of PD patients achieved a phosphate within the range recommended by the RA clinical practice guidelines. Seventy-five percent of HD and 76% of PD patients had adjusted calcium between 2.2-2.5 mmol/L. Twenty-eight percent of HD and 31% of PD patients had parathyroid hormone between 16- 32 pmol/L. Sixty percent of HD and 80% of PD patients achieved the audit measure for bicarbonate. There was significant inter-centre variation for all variables studied. The UKRR consistently demonstrates significant inter-centre variation in achievement of biochemical clinical audit measures. Understanding the causes of this variation is an important part of improving the care of dialysis patients in the UK. Copyright © 2012 S. Karger AG, Basel.

  16. Know thyself: misperceptions of actual performance undermine achievement motivation, future performance, and subjective well-being.

    PubMed

    Kim, Young-Hoon; Chiu, Chi-Yue; Zou, Zhimin

    2010-09-01

    Contrary to the popular assumption that self-enhancement improves task motivation and future performance, the authors propose that both inflated and deflated self-assessments of performance are linked to an increased likelihood of practicing self-handicapping and having relatively poor performance in future tasks. Consistent with this proposal, we found that irrespective of the level of actual performance, compared with accurate self-assessment, both inflated and deflated self-assessments of task performance are associated with a greater tendency to (a) practice self-handicapping (Study 1: prefer to work under distraction; Study 2: withhold preparatory effort), (b) perform relatively poorly in a subsequent task (Study 3), (c) have relatively low academic achievement (Study 4), and (d) report a relatively low level of subjective well-being (Study 5). The authors discuss these results in terms of their educational implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  17. A Comparative Study of Academic Achievement and Participation in a High School Freshman Academy

    ERIC Educational Resources Information Center

    Seng, Mark Patrick

    2014-01-01

    The transition to high school can be problematic for many ninth graders. Researchers and administrators have sought ways to improve academic performance and promotion rates while reducing dropout rates. A quantitative causal-comparative (ex post facto) and correlation study using a two-group design compared two freshman classes at separate…

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Theiler, James; Grosklos, Guen

    We examine the properties and performance of kernelized anomaly detectors, with an emphasis on the Mahalanobis-distance-based kernel RX (KRX) algorithm. Although the detector generally performs well for high-bandwidth Gaussian kernels, it exhibits problematic (in some cases, catastrophic) performance for distances that are large compared to the bandwidth. By comparing KRX to two other anomaly detectors, we can trace the problem to a projection in feature space, which arises when a pseudoinverse is used on the covariance matrix in that feature space. Here, we show that a regularized variant of KRX overcomes this difficulty and achieves superior performance over a widemore » range of bandwidths.« less

  19. How Different EEG References Influence Sensor Level Functional Connectivity Graphs

    PubMed Central

    Huang, Yunzhi; Zhang, Junpeng; Cui, Yuan; Yang, Gang; He, Ling; Liu, Qi; Yin, Guangfu

    2017-01-01

    Highlights: Hamming Distance is applied to distinguish the difference of functional connectivity networkThe orientations of sources are testified to influence the scalp Functional Connectivity Graph (FCG) from different references significantlyREST, the reference electrode standardization technique, is proved to have an overall stable and excellent performance in variable situations. The choice of an electroencephalograph (EEG) reference is a practical issue for the study of brain functional connectivity. To study how EEG reference influence functional connectivity estimation (FCE), this study compares the differences of FCE resulting from the different references such as REST (the reference electrode standardization technique), average reference (AR), linked mastoids (LM), and left mastoid references (LR). Simulations involve two parts. One is based on 300 dipolar pairs, which are located on the superficial cortex with a radial source direction. The other part is based on 20 dipolar pairs. In each pair, the dipoles have various orientation combinations. The relative error (RE) and Hamming distance (HD) between functional connectivity matrices of ideal recordings and that of recordings obtained with different references, are metrics to compare the differences of the scalp functional connectivity graph (FCG) derived from those two kinds of recordings. Lower RE and HD values imply more similarity between the two FCGs. Using the ideal recording (IR) as a standard, the results show that AR, LM and LR perform well only in specific conditions, i.e., AR performs stable when there is no upward component in sources' orientation. LR achieves desirable results when the sources' locations are away from left ear. LM achieves an indistinct difference with IR, i.e., when the distribution of source locations is symmetric along the line linking the two ears. However, REST not only achieves excellent performance for superficial and radial dipolar sources, but also achieves a stable and robust performance with variable source locations and orientations. Benefitting from the stable and robust performance of REST vs. other reference methods, REST might best recover the real FCG of EEG. Thus, REST based FCG may be a good candidate to compare the FCG of EEG based on different references from different labs. PMID:28725175

  20. Achievement Levels of Middle School Students in the Standardized Science and Technology Exam and Formative Assessment Probes: A Comparative Study

    ERIC Educational Resources Information Center

    Bulunuz, Nermin; Bulunuz, Mizrap; Karagoz, Funda; Tavsanli, Omer Faruk

    2016-01-01

    The present study has two aims. Firstly, it aims to determine eighth grade students' conceptual understanding of floating and sinking through formative assessment probes. Secondly, it aims to determine whether or not there is a significant difference between students' performance in formative assessment probes and their achievement in the…

  1. An Examination of Resource Allocation Strategies That Promote Student Achievement: Case Studies of Rural Elementary Schools in Hawaii

    ERIC Educational Resources Information Center

    Acopan-Tuasivi, C. K.

    2012-01-01

    This study presents case studies of rural elementary schools in Hawaii that examine resource allocation strategies that promote student achievement. The combined frame work of the Evidence Based Model (Odden & Picus, 2008) and the 10 Strategies for Doubling Student Performance (Odden, 2009) were utilized to compare actual school resources and…

  2. The Impact of Response to Intervention on Student Reading Achievement in Urban Elementary Schools

    ERIC Educational Resources Information Center

    Weaver, Wendy Smyth

    2011-01-01

    The purpose of this study was to determine if the implementation of a Response to Intervention framework had a positive impact on student reading achievement in urban elementary schools. This was a causal-comparative study that examined the reading performance of a sample of kindergarten through grade three students who experienced the Response to…

  3. Testing a Multi-Stage Screening System: Predicting Performance on Australia's National Achievement Test Using Teachers' Ratings of Academic and Social Behaviors

    ERIC Educational Resources Information Center

    Kettler, Ryan J.; Elliott, Stephen N.; Davies, Michael; Griffin, Patrick

    2012-01-01

    This study addresses the predictive validity of results from a screening system of academic enablers, with a sample of Australian elementary school students, when the criterion variable is end-of-year achievement. The investigation included (a) comparing the predictive validity of a brief criterion-referenced nomination system with more…

  4. Highlights from PIRLS 2011: Reading Achievement of U.S. Fourth-Grade Students in an International Context. NCES 2013-010

    ERIC Educational Resources Information Center

    Thompson, Sheila; Provasnik, Stephen; Kastberg, David; Ferraro, David; Lemanski, Nita; Roey, Stephen; Jenkins, Frank

    2012-01-01

    The Progress in International Reading Literacy Study (PIRLS) is an international comparative study of student achievement. In 2011, PIRLS was administered to nationally representative samples of 4th-grade students in 53 education systems around the world. The PIRLS assessment measures student performance on a combined reading literacy scale, as…

  5. Comparing Student Achievement in Single-Gender and Coeducational Classrooms Using the Tennessee Comprehensive Achievement Program

    ERIC Educational Resources Information Center

    Young, La Sandra M.

    2016-01-01

    Schools across the nation are faced with an increased urgency to seek innovative strategies to improve low academic performance of students as mandated by No Child Left Behind Legislation (Friend, 2006). Specifically, in the state of Tennessee in schools such as those located in the Shelby County Schools District who have experienced low student…

  6. PARLO: PArallel Run-Time Layout Optimization for Scientific Data Explorations with Heterogeneous Access Pattern

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gong, Zhenhuan; Boyuka, David; Zou, X

    Download Citation Email Print Request Permissions Save to Project The size and scope of cutting-edge scientific simulations are growing much faster than the I/O and storage capabilities of their run-time environments. The growing gap is exacerbated by exploratory, data-intensive analytics, such as querying simulation data with multivariate, spatio-temporal constraints, which induces heterogeneous access patterns that stress the performance of the underlying storage system. Previous work addresses data layout and indexing techniques to improve query performance for a single access pattern, which is not sufficient for complex analytics jobs. We present PARLO a parallel run-time layout optimization framework, to achieve multi-levelmore » data layout optimization for scientific applications at run-time before data is written to storage. The layout schemes optimize for heterogeneous access patterns with user-specified priorities. PARLO is integrated with ADIOS, a high-performance parallel I/O middleware for large-scale HPC applications, to achieve user-transparent, light-weight layout optimization for scientific datasets. It offers simple XML-based configuration for users to achieve flexible layout optimization without the need to modify or recompile application codes. Experiments show that PARLO improves performance by 2 to 26 times for queries with heterogeneous access patterns compared to state-of-the-art scientific database management systems. Compared to traditional post-processing approaches, its underlying run-time layout optimization achieves a 56% savings in processing time and a reduction in storage overhead of up to 50%. PARLO also exhibits a low run-time resource requirement, while also limiting the performance impact on running applications to a reasonable level.« less

  7. Nitrogen-based catalysts for the electrochemical reduction of CO2 to CO.

    PubMed

    Tornow, Claire E; Thorson, Michael R; Ma, Sichao; Gewirth, Andrew A; Kenis, Paul J A

    2012-12-05

    The synthesis and application of carbon-supported, nitrogen-based organometallic silver catalysts for the reduction of CO(2) is studied using an electrochemical flow reactor. Their performance toward the selective formation of CO is similar to the performance achieved when using Ag as the catalyst, but comparatively at much lower silver loading. Faradaic efficiencies of the organometallic catalyst are higher than 90%, which are comparable to those of Ag. Furthermore, with the addition of an amine ligand to Ag/C, the partial current density for CO increases significantly, suggesting a possible co-catalyst mechanism. Additional improvements in activity and selectivity may be achieved as greater insight is obtained on the mechanism of CO(2) reduction and on how these complexes assemble on the carbon support.

  8. An Experimental Study on the Iso-Content-Based Angle Similarity Measure.

    ERIC Educational Resources Information Center

    Zhang, Jin; Rasmussen, Edie M.

    2002-01-01

    Retrieval performance of the iso-content-based angle similarity measure within the angle, distance, conjunction, disjunction, and ellipse retrieval models is compared with retrieval performance of the distance similarity measure and the angle similarity measure. Results show the iso-content-based angle similarity measure achieves satisfactory…

  9. Age-related changes in ultra-triathlon performances

    PubMed Central

    2012-01-01

    Background The age-related decline in performance has been investigated in swimmers, runners and triathletes. No study has investigated the age-related performance decline in ultra-triathletes. The purpose of this study was to analyse the age-related declines in swimming, cycling, running and overall race time for both Triple Iron ultra-triathlon (11.4-km swimming, 540-km cycling and 126.6-km running) and Deca Iron ultra-triathlon (38-km swimming, 1,800-km cycling and 420-km running). Methods The age and performances of 423 male Triple Iron ultra-triathletes and 119 male Deca Iron ultra-triathletes were analysed from 1992 to 2010 using regression analyses and ANOVA. Results The mean age of the finishers was significantly higher for Deca Iron ultra-triathletes (41.3 ± 3.1 years) compared to a Triple Iron ultra-triathletes (38.5 ± 3.3 years) (P < 0.05). For both ultra-distances, the fastest overall race times were achieved between the ages of 25 and 44 years. Deca Iron ultra-triathletes achieved the same level of performance in swimming and cycling between 25 and 54 years of age. Conclusions The magnitudes of age-related declines in performance in the three disciplines of ultra-triathlon differ slightly between Triple and Deca Iron ultra-triathlon. Although the ages of Triple Iron ultra-triathletes were on average younger compared to Deca Iron ultra-triathletes, the fastest race times were achieved between 25 and 44 years for both distances. Further studies should investigate the motivation and training of ultra-triathletes to gain better insights in ultra-triathlon performance. PMID:23849327

  10. Laterality of Oral Clefts and Academic Achievement.

    PubMed

    Gallagher, Emily R; Collett, Brent R; Barron, Sheila; Romitti, Paul; Ansley, Timothy; Wehby, George L

    2017-02-01

    Children with isolated oral clefts have lower academic performance when compared with unaffected peers, yet few studies have examined specific attributes of clefts that may modify this risk. Oral clefts have nonrandom laterality, with left-sided clefts being more common than right-sided clefts, a pattern that may be genetically or environmentally influenced. The objective of this study was to evaluate the association between cleft laterality and academic achievement in a population-based sample of children with and without isolated oral clefts. The study included 292 children with isolated unilateral cleft lip with or without cleft palate identified by using the Iowa Registry for Congenital and Inherited Disorders matched with 908 unaffected classmates. This group provided 1953 child-grade observations for cases and 6829 for classmates. Academic achievement was evaluated by using high-quality standardized test data on multiple academic domains as well as use of special education. We found that children with right-sided clefts had similar achievement scores and usage of special education services compared with their unaffected classmates. Children with left-sided clefts had lower reading scores than children with right-sided clefts by nearly 7 percentiles (P < .05). They also had lower scores on all evaluated domains by 4 to 6 percentiles and greater use of special education services by 6 percentage points than their classmates. Children with left-sided clefts had poorer academic performance than their classmates or children with right-sided clefts, who showed similar academic achievement compared with their unaffected classmates. Copyright © 2017 by the American Academy of Pediatrics.

  11. Requirements for a Hydrogen Powered All-Electric Manned Helicopter

    NASA Technical Reports Server (NTRS)

    Datta, Anubhav

    2012-01-01

    The objective of this paper is to set propulsion system targets for an all-electric manned helicopter of ultra-light utility class to achieve performance comparable to combustion engines. The approach is to begin with a current two-seat helicopter (Robinson R 22 Beta II-like), design an all-electric power plant as replacement for its existing piston engine, and study performance of the new all-electric aircraft. The new power plant consists of high-pressure Proton Exchange Membrane fuel cells, hydrogen stored in 700 bar type-4 tanks, lithium-ion batteries, and an AC synchronous permanent magnet motor. The aircraft and the transmission are assumed to remain the same. The paper surveys the state of the art in each of these areas, synthesizes a power plant using best available technologies in each, examines the performance achievable by such a power plant, identifies key barriers, and sets future technology targets to achieve performance at par with current internal combustion engines.

  12. Comparison of a hydrogel corneal inlay and monovision laser in situ keratomileusis in presbyopic patients: focus on visual performance and optical quality.

    PubMed

    Verdoorn, Cornelis

    2017-01-01

    To compare the visual performance and optical quality after Raindrop Near Vision Inlay implantation or monovision LASIK for the correction of presbyopia. In this retrospective case-series study, patients previously treated in the nondominant eye with monovision LASIK were compared with patients previously implanted with Raindrop Near Vision Inlay. The study enrolled 16 inlay and 15 monovision LASIK patients. Uncorrected near visual acuity, uncorrected distance visual acuity, binocular stereopsis, patient satisfaction, and patient task performance were assessed. Postoperatively, the mean spherical equivalent was -0.66 D (0.78 SD) for the inlay group and -1.03 D (0.56 SD) for the monovision LASIK group. Monocularly, at uncorrected near distances, 60% of inlay patients and 47% of monovision LASIK patients achieved ≥20/20. Monocularly, at uncorrected far distances, 75% of inlay patients and 40% of monovision LASIK patients achieved ≥20/32 vision. Binocularly, at near distances, 79% of inlay patients and 53% of monovision LASIK patients obtained ≥20/20 vision. All patients achieved ≥20/20 binocularly for distance. On average, inlay patients obtained 98 seconds of arc and monovision LASIK patients obtained 286 seconds of arc for stereopsis. Most (79%) of the inlay patients and 66% of monovision LASIK patients were satisfied with their near vision, while 86% of inlay patients and 67% of monovision LASIK patients were satisfied with their distance vision. Patients receiving corneal inlays demonstrated better near and distance visual acuities, binocular stereopsis, task performance, and satisfaction, when compared to patients treated with monovision LASIK.

  13. Can Virtual Schools Thrive in the Real World?

    ERIC Educational Resources Information Center

    Wang, Yinying; Decker, Janet R.

    2014-01-01

    Despite the relatively large number of students enrolled in Ohio's virtual schools, it is unclear how virtual schools compare to their traditional school counterparts on measures of student achievement. To provide some insight, we compared the school performance from 2007-2011 at Ohio's virtual and traditional schools. The results suggest that…

  14. Trend Analysis on Mathematics Achievements: A Comparative Study Using TIMSS Data

    ERIC Educational Resources Information Center

    Ker, H. W.

    2013-01-01

    Research addressed the importance of mathematics education for the students' preparation to enter scientific and technological workforce. This paper utilized Trends in International Mathematics and Science Study (TIMSS) 2011 data to conduct a global comparative analysis on mathematics performance at varied International Benchmark levels. The…

  15. Correlation between academic achievement goal orientation and the performance of Malaysian students in an Indian medical school.

    PubMed

    Barkur, Rajashekar Rao; Govindan, Sreejith; Kamath, Asha

    2013-01-01

    According to goal orientation theory, achievement goals are defined as the terminal point towards which one's efforts are directed. The four academic achievement goal orientations commonly recognised are mastery, performance approach, performance avoidance and work avoidance. The objective of this study was to understand the goal orientation of second year undergraduate medical students and how this correlates with their academic performance. The study population consisted of 244 second year Bachelor of Medicine and Bachelor of Surgery (MBBS) students of Melaka Manipal Medical College, Manipal campus, Manipal University, India. Students were categorised as high performers and low performers based on their first year university examination marks. Their goal orientations were assessed through a validated questionnaire developed by Was et al. These components were analysed by independent sample t-test and correlated to their first year university examination marks. Confirmatory component factor analysis extracted four factors, which accounted for 40.8% of the total variance in goal orientation. The performance approach goal orientation alone explained 16.7% of the variance followed by mastery (10.8%), performance avoidance (7.7%) and work avoidance (5.7%). The Cronbach's alpha for 19 items, which contributed to internal consistency of the tool, was observed to be 0.635. A strong positive correlation was shown between performance approach, performance avoidance and work avoidance orientations. Of the four goal orientations, only the mean scores in work avoidance orientation differed for low performers and high performers (5.0 vs. 4.3; P = 0.0003). Work avoidance type of goal orientation among the low performer group may account for their lower performance compared with high performer group. This indicates that academic achievement goal orientation may play a role in the performance of undergraduate medical students.

  16. Stereotyped: investigating gender in introductory science courses.

    PubMed

    Lauer, Shanda; Momsen, Jennifer; Offerdahl, Erika; Kryjevskaia, Mila; Christensen, Warren; Montplaisir, Lisa

    2013-01-01

    Research in science education has documented achievement gaps between men and women in math and physics that may reflect, in part, a response to perceived stereotype threat. Research efforts to reduce achievement gaps by mediating the impact of stereotype threat have found success with a short values-affirmation writing exercise. In biology and biochemistry, however, little attention has been paid to the performance of women in comparison with men or perceptions of stereotype threat, despite documentation of leaky pipelines into professional and academic careers. We used methodologies developed in physics education research and cognitive psychology to 1) investigate and compare the performance of women and men across three introductory science sequences (biology, biochemistry, physics), 2) document endorsement of stereotype threat in these science courses, and 3) investigate the utility of a values-affirmation writing task in reducing achievement gaps. In our study, analysis of final grades and normalized learning gains on content-specific concept inventories reveals no achievement gap in the courses sampled, little stereotype threat endorsement, and no impact of the values-affirmation writing task on student performance. These results underscore the context-dependent nature of achievement gaps and stereotype threat and highlight calls to replicate education research across a range of student populations.

  17. Stereotyped: Investigating Gender in Introductory Science Courses

    PubMed Central

    Lauer, Shanda; Momsen, Jennifer; Offerdahl, Erika; Kryjevskaia, Mila; Christensen, Warren; Montplaisir, Lisa

    2013-01-01

    Research in science education has documented achievement gaps between men and women in math and physics that may reflect, in part, a response to perceived stereotype threat. Research efforts to reduce achievement gaps by mediating the impact of stereotype threat have found success with a short values-affirmation writing exercise. In biology and biochemistry, however, little attention has been paid to the performance of women in comparison with men or perceptions of stereotype threat, despite documentation of leaky pipelines into professional and academic careers. We used methodologies developed in physics education research and cognitive psychology to 1) investigate and compare the performance of women and men across three introductory science sequences (biology, biochemistry, physics), 2) document endorsement of stereotype threat in these science courses, and 3) investigate the utility of a values-affirmation writing task in reducing achievement gaps. In our study, analysis of final grades and normalized learning gains on content-specific concept inventories reveals no achievement gap in the courses sampled, little stereotype threat endorsement, and no impact of the values-affirmation writing task on student performance. These results underscore the context-dependent nature of achievement gaps and stereotype threat and highlight calls to replicate education research across a range of student populations. PMID:23463226

  18. Video gaming and gender differences in digital and printed reading performance among 15-year-olds students in 26 countries.

    PubMed

    Borgonovi, Francesca

    2016-04-01

    Video games are a favorite leisure-time activity among teenagers worldwide. This study examines cross-national gender differences in reading achievement and video gaming and whether video gaming explains gender differences in reading achievement and differences in performance between paper-based and computer-based reading. We use data from a representative sample of 145,953 students from 26 countries who sat the PISA 2012 assessments and provided self-reports on use of video games. Although boys tend to have poorer results in both the computer-based and the paper-based reading assessments, boys' under achievement is smaller when the assessment is delivered on computer than when it is delivered on paper. Boys underperformance compared to girls in the two reading assessments is particularly pronounced among low-achieving students. Among both boys and girls moderate use of single-player games is associated with a performance advantage. However, frequent engagement with collaborative online games is generally associated with a steep reduction in achievement, particularly in the paper-based test and particularly among low-achieving students. Excessive gaming may hinder academic achievement, but moderate gaming can promote positive student outcomes. In many countries video gaming explains the difference in the gender gap in reading between the paper-based and the computer-based assessments. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  19. U.S. energy sector impacts of technology innovation, fuel price, and electric sector CO 2 policy: Results from the EMF 32 model intercomparison study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hodson, Elke L.; Brown, Maxwell; Cohen, Stuart

    We study the impact of achieving technology innovation goals, representing significant technology cost reductions and performance improvements, in both the electric power and end-use sectors by comparing outputs from four energy-economic models through the year 2050. We harmonize model input assumptions and then compare results in scenarios that vary natural gas prices, technology cost and performance metrics, and the implementation of a representative national electricity sector carbon dioxide (CO 2) policy. Achieving the representative technology innovation goals decreases CO 2 emissions in all models, regardless of natural gas price, due to increased energy efficiency and low-carbon generation becoming more costmore » competitive. For the models that include domestic natural gas markets, achieving the technology innovation goals lowers wholesale electricity prices, but this effect diminishes as projected natural gas prices increase. Higher natural gas prices lead to higher wholesale electricity prices but fewer coal capacity retirements. Some of the models include energy efficiency improvements as part of achieving the high-technology goals. Absent these energy efficiency improvements, low-cost electricity facilitates greater electricity consumption. The effect of implementing a representative electricity sector CO 2 policy differs considerably depending on the cost and performance of generating and end-use technologies. The CO 2 policy influences electric sector evolution in the cases with reference technology assumptions but has little to no influence in the cases that achieve the technology innovation goals. This outcome implies that meeting the representative technology innovation goals achieves a generation mix with similar CO 2 emissions to the representative CO 2 policy but with smaller increases to wholesale electricity prices. Finally, higher natural gas prices, achieving the representative technology innovation goals, and the combination of the two, increases the amount of renewable generation that is cost-effective to build and operate while slowing the growth of natural-gas fired generation, which is the predominant generation type in 2050 under reference conditions.« less

  20. Influence of perceived motivational climate on achievement goals in physical education: a structural equation mixture modeling analysis.

    PubMed

    Wang, J C; Liu, W C; Chatzisarantis, N L; Lim, C B

    2010-06-01

    The purpose of the current study was to examine the influence of perceived motivational climate on achievement goals in physical education using a structural equation mixture modeling (SEMM) analysis. Within one analysis, we identified groups of students with homogenous profiles in perceptions of motivational climate and examined the relationships between motivational climate, 2 x 2 achievement goals, and affect, concurrently. The findings of the current study showed that there were at least two distinct groups of students with differing perceptions of motivational climate: one group of students had much higher perceptions in both climates compared with the other group. Regardless of their grouping, the relationships between motivational climate, achievement goals, and enjoyment seemed to be invariant. Mastery climate predicted the adoption of mastery-approach and mastery-avoidance goals; performance climate was related to performance-approach and performance-avoidance goals. Mastery-approach goal had a strong positive effect while performance-avoidance had a small negative effect on enjoyment. Overall, it was concluded that only perception of a mastery motivational climate in physical education may foster intrinsic interest in physical education through adoption of mastery-approach goals.

  1. Comparison of computer-assisted instruction (CAI) versus traditional textbook methods for training in abdominal examination (Japanese experience).

    PubMed

    Qayumi, A K; Kurihara, Y; Imai, M; Pachev, G; Seo, H; Hoshino, Y; Cheifetz, R; Matsuura, K; Momoi, M; Saleem, M; Lara-Guerra, H; Miki, Y; Kariya, Y

    2004-10-01

    This study aimed to compare the effects of computer-assisted, text-based and computer-and-text learning conditions on the performances of 3 groups of medical students in the pre-clinical years of their programme, taking into account their academic achievement to date. A fourth group of students served as a control (no-study) group. Participants were recruited from the pre-clinical years of the training programmes in 2 medical schools in Japan, Jichi Medical School near Tokyo and Kochi Medical School near Osaka. Participants were randomly assigned to 4 learning conditions and tested before and after the study on their knowledge of and skill in performing an abdominal examination, in a multiple-choice test and an objective structured clinical examination (OSCE), respectively. Information about performance in the programme was collected from school records and students were classified as average, good or excellent. Student and faculty evaluations of their experience in the study were explored by means of a short evaluation survey. Compared to the control group, all 3 study groups exhibited significant gains in performance on knowledge and performance measures. For the knowledge measure, the gains of the computer-assisted and computer-assisted plus text-based learning groups were significantly greater than the gains of the text-based learning group. The performances of the 3 groups did not differ on the OSCE measure. Analyses of gains by performance level revealed that high achieving students' learning was independent of study method. Lower achieving students performed better after using computer-based learning methods. The results suggest that computer-assisted learning methods will be of greater help to students who do not find the traditional methods effective. Explorations of the factors behind this are a matter for future research.

  2. Strategies to optimize lithium-ion supercapacitors achieving high-performance: Cathode configurations, lithium loadings on anode, and types of separator

    NASA Astrophysics Data System (ADS)

    Cao, Wanjun; Li, Yangxing; Fitch, Brian; Shih, Jonathan; Doung, Tien; Zheng, Jim

    2014-12-01

    The Li-ion capacitor (LIC) is composed of a lithium-doped carbon anode and an activated carbon cathode, which is a half Li-ion battery (LIB) and a half electrochemical double-layer capacitor (EDLC). LICs can achieve much more energy density than EDLC without sacrificing the high power performance advantage of capacitors over batteries. LIC pouch cells were assembled using activated carbon (AC) cathode and hard carbon (HC) + stabilized lithium metal power (SLMP®) anode. Different cathode configurations, various SLMP loadings on HC anode, and two types of separators were investigated to achieve the optimal electrochemical performance of the LIC. Firstly, the cathode binders study suggests that the PTFE binder offers improved energy and power performances for LIC in comparison to PVDF. Secondly, the mass ratio of SLMP to HC is at 1:7 to obtain the optimized electrochemical performance for LIC among all the various studied mass ratios between lithium loading amounts and active anode material. Finally, compared to the separator Celgard PP 3501, cellulose based TF40-30 is proven to be a preferred separator for LIC.

  3. Race, Socioeconomic Status, and Implicit Bias: Implications for Closing the Achievement Gap

    NASA Astrophysics Data System (ADS)

    Schlosser, Elizabeth Auretta Cox

    This study accessed the relationship between race, socioeconomic status, age and the race implicit bias held by middle and high school science teachers in Mobile and Baldwin County Public School Systems. Seventy-nine participants were administered the race Implicit Association Test (race IAT), created by Greenwald, A. G., Nosek, B. A., & Banaji, M. R., (2003) and a demographic survey. Quantitative analysis using analysis of variances, ANOVA and t-tests were used in this study. An ANOVA was performed comparing the race IAT scores of African American science teachers and their Caucasian counterparts. A statically significant difference was found (F = .4.56, p = .01). An ANOVA was also performed using the race IAT scores comparing the age of the participants; the analysis yielded no statistical difference based on age. A t-test was performed comparing the race IAT scores of African American teachers who taught at either Title I or non-Title I schools; no statistical difference was found between groups (t = -17.985, p < .001). A t-test was also performed comparing the race IAT scores of Caucasian teachers who taught at either Title I or non-Title I schools; a statistically significant difference was found between groups ( t = 2.44, p > .001). This research examines the implications of the achievement gap among African American and Caucasian students in science.

  4. Afro-Caribbean and African American Students, Family Factors, and the Influence on Science Performance in the United States: The Untold Story

    ERIC Educational Resources Information Center

    Pinder, Patrice Juliet

    2012-01-01

    The primary objectives of this research were to explore achievement pattern differences and the influence of family factors on the achievement patterns of Afro-Caribbean and African American students within the United States (U.S.). The study utilized two research designs; a causal-comparative and a correlational design. A student family…

  5. The Impact of Year-Round Education on Fifth Grade African American Reading Achievement Scores in an Urban Illinois School

    ERIC Educational Resources Information Center

    Merrill, Carolyn Ann

    2012-01-01

    The purpose of this quantitative, causal-comparative study was to determine the impact of the year-round education school calendar on the standardized test performance of fifth grade African American students, as measured by the Illinois Standards Achievement Test (ISAT) in reading. The ISAT reading scores from two year-round education (YRE)…

  6. Characterizing the Learning Curve of the VBLaST-PT© (Virtual Basic Laparoscopic Skill Trainer)

    PubMed Central

    Zhang, Likun; Sankaranarayanan, Ganesh; Arikatla, Venkata Sreekanth; Ahn, Woojin; Grosdemouge, Cristol; Rideout, Jesse M.; Epstein, Scott K.; De, Suvranu; Schwaitzberg, Steven D.; Jones, Daniel B.; Cao, Caroline G.L.

    2013-01-01

    Background and study aim Mastering laparoscopic surgical skills requires considerable time and effort. The Virtual Basic Laparoscopic Skill Trainer (VBLaST-PT©) is being developed as a computerized version of the peg transfer task of the Fundamentals of Laparoscopic Surgery (FLS) system using virtual reality technology. We assessed the learning curve of trainees on the VBLaST-PT© using the cumulative summation (CUSUM) method and compared them with those on the FLS to establish convergent validity for the VBLaST-PT©. Methods Eighteen medical students from were assigned randomly to one of three groups: control, VBLaST-training and FLS-training. The VBLaST and the FLS groups performed a total of 150 trials of the peg-transfer task over a three week period, five days a week. Their CUSUM scores were computed based on pre-defined performance criteria (junior, intermediate and senior levels). Results Of the six subjects in the VBLaST-training group, five achieved at least the “junior” level, three achieved the “intermediate” level and one achieved the “senior” level of performance criterion by the end of the 150 trials. In comparison, for the FLS group, three students achieved the “senior” criterion and all six students achieved the “intermediate” and “junior” criteria by the 150th trials. Both the VBLaST-PT© and the FLS systems showed significant skill improvement and retention, albeit with system specificity as measured by transfer of learning in the retention test: The VBLaST-trained group performed better on the VBLaST-PT© than on FLS (p=0.003), while the FLS-trained group performed better on the FLS than on VBLaST-PT© (p=0.002). Conclusion We characterized the learning curve for a virtual peg transfer task on the VBLaST-PT© and compared it with the FLS using CUSUM analysis. Subjects in both training groups showed significant improvement in skill performance, but the transfer of training between systems was not significant. PMID:23572217

  7. A quasi-experimental study of maternal smoking during pregnancy and offspring academic achievement

    PubMed Central

    D'Onofrio, Brian M.; Singh, Amber L.; Iliadou, Anastasia; Lambe, Mats; Hultman, Christina M.; Neiderhiser, Jenae M.; Långström, Niklas; Lichtenstein, Paul

    2013-01-01

    Maternal smoking during pregnancy (SDP) is associated with lower academic achievement in offspring. The current study, which was based on all births in Sweden from 1983 through 1991, explored the possible causal processes underlying the association between SDP and offspring school grades and a standardized assessment of mathematic proficiency at age 15. The analyses compared relatives who varied in their exposure to SDP and who varied in their genetic relatedness. Although SDP was statistically associated with academic achievement when comparing unrelated individuals, the results suggest that SDP does not cause poorer academic performance, as full siblings differentially exposed to SDP did not differ in their academic scores. The pattern of results suggests that genetic factors shared by parents and their offspring explain significant variance in why offspring opposed to SDP have lower levels of academic achievement. Nevertheless, SDP impacts pregnancy-related outcomes. Reducing SDP, therefore, remains a major public health issue. PMID:20331655

  8. 2 CFR 200.76 - Performance goal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... achievement can be compared, including a goal expressed as a quantitative standard, value, or rate. In some instances (e.g., discretionary research awards), this may be limited to the requirement to submit technical...

  9. Comparison of SIRTF dewar performance in the 900 km and 100,000 km orbits

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Maa, S. S.; Ng, Y. S.

    1990-01-01

    Feasibility studies showed that the Space Infrared Telescope Facility (SIRTF) can be launched into a 100,000-km high earth orbit (HEO) using a Titan/Centaur launch vehicle. This paper compares the performance of an all-superfluid helium dewar system for SIRTF under conditions of the LEO (900-km) and the HEO missions. Results show that the SIRTF all-superfluid He dewar can achieve a 5-yr lifetime for the 100,000 km HEO mission, with 20 percent margin. Methods to achieve further enhancement of dewar lifetime for the HEO mission are suggested.

  10. Comparing standardized measures of diligence and achievement with dental student academic performance.

    PubMed

    Jedrychowski, Joseph; Lindemann, Robert

    2005-04-01

    Utilizing a reliable and valid instrument to measure a student's application of energy and effort towards a goal (diligence) or the ability to reach goals (achievement) would enable dental educators to anticipate academic performance. This knowledge could be used to better distribute faculty and educational resources, as additional tutors could be provided for students who score low on diligence and achievement instruments. In this study, fourth-year dental students completed the Diligence Inventory and the NachNaff Scale (which measures desire to achieve) immediately prior to graduation. The scores from both inventories were correlated with nine measures of academic performance. For males, the NachNaff Scale positively correlated (p<.05) only with the quantity of exceptional performance reports (EPR) and for females negatively correlated only with science DAT scores. The modest positive correlations, which differ for gender, suggest that the NachNaff may be of limited use to predict dental student performance. For males, the Total Diligence mean positively correlated with EPR and National Board Parts I and II scores. For females, the Total Diligence mean positively correlated with EPR and a predental biology-chemistry-physics grade composite. Given the simplicity of the Diligence Inventory and its significant correlations with academic performance demonstrated in this study, it appears to be a useful tool to gain insight into students' diligence in striving to obtain goals.

  11. PISA, Policy and Persuasion: Translating Complex Conditions into Education "Best Practice"

    ERIC Educational Resources Information Center

    Auld, Euan; Morris, Paul

    2016-01-01

    Education reform is increasingly portrayed as a means to improve a nation's global competitiveness as measured by its performance in international league tables of pupil achievement. This has created a demand for comparative research which identifies "what works" in high-performing school systems. A diverse array of consultancies, thinks…

  12. A Descriptive-Comparative Study of Teacher Performance Evaluation on Student Achievement in a Public School District

    ERIC Educational Resources Information Center

    Christensen, William Howard

    2013-01-01

    In 2010, the federal government increased accountability expectations by placing more emphasis on monitoring teacher performance. Using a model that focuses on the New York State teacher evaluation system, that is comprised of a rubric for observation, local student assessment scores, and student state assessment scores, this…

  13. Examining Differences in Middle School Student Achievement on a Criterion-Referenced Competency Test (CRCT) in Science

    ERIC Educational Resources Information Center

    Rich, Jamie; Duncan, Dennis W.; Navarro, Maria; Ricketts, John C.

    2009-01-01

    Many authors have posited that agricultural education curriculum in middle schools may enhance student performance in science. To determine the effect that agricultural education curriculum has upon Georgia middle schools' student performance in science, this descriptive study compared science knowledge among middle school students in Georgia who…

  14. Parent-School Involvement and School Performance: Mediated Pathways among Socioeconomically Comparable African American and Euro-American Families.

    ERIC Educational Resources Information Center

    Hill, Nancy E.; Craft, Stacie A.

    2003-01-01

    Examines children's social and academic competencies as mediators to explain the often positive relation between parent-school involvement and achievement. Ethnic variation was examined. For African Americans, academic skills mediated the relations between school involvement and math performance. For Euro-Americans, social competence mediated the…

  15. Self-Concepts, Locus of Control and Performance Expectations of Learning Disabled Children.

    ERIC Educational Resources Information Center

    Rogers, H.; Saklofski, D. H.

    1985-01-01

    Compared to 45 normally achieving students, 45 learning disabled six- to 12-year-olds had lower self-concepts, more external locus of control orientations, and lower performance expectations. Children new to the resource room had higher expectations for future success than Ss with experience in the resource room. (CL)

  16. The Relationship between Student Achievement and Multilingualism: A Quantitative Causal-Comparative Study

    ERIC Educational Resources Information Center

    Thomson, Jennifer Barbara

    2010-01-01

    Student performance in basic math and reading skills in the United States trails behind other developed countries, providing the rationale for more research to determine how performance might be improved. Following evidence to conclude that multilingualism enhances cognitive, neuro-linguistic and meta-linguistic development, it is proposed that…

  17. Comparative health system performance in six middle-income countries: cross-sectional analysis using World Health Organization study of global ageing and health.

    PubMed

    Alshamsan, Riyadh; Lee, John Tayu; Rana, Sangeeta; Areabi, Hasan; Millett, Christopher

    2017-09-01

    Objective To assess and compare health system performance across six middle-income countries that are strengthening their health systems in pursuit of universal health coverage. Design Cross-sectional analysis from the World Health Organization Study on global AGEing and adult health, collected between 2007 and 2010. Setting Six middle-income countries: China, Ghana, India, Mexico, Russia and South Africa. Participants Nationally representative sample of adults aged 50 years and older. Main outcome measures We present achievement against key indicators of health system performance across effectiveness, cost, access, patient-centredness and equity domains. Results We found areas of poor performance in prevention and management of chronic conditions, such as hypertension control and cancer screening coverage. We also found that cost remains a barrier to healthcare access in spite of insurance schemes. Finally, we found evidence of disparities across many indicators, particularly in the effectiveness and patient centredness domains. Conclusions These findings identify important focus areas for action and shared learning as these countries move towards achieving universal health coverage.

  18. Comparative health system performance in six middle-income countries: cross-sectional analysis using World Health Organization study of global ageing and health

    PubMed Central

    Alshamsan, Riyadh; Lee, John Tayu; Rana, Sangeeta; Areabi, Hasan; Millett, Christopher

    2017-01-01

    Objective To assess and compare health system performance across six middle-income countries that are strengthening their health systems in pursuit of universal health coverage. Design Cross-sectional analysis from the World Health Organization Study on global AGEing and adult health, collected between 2007 and 2010. Setting Six middle-income countries: China, Ghana, India, Mexico, Russia and South Africa. Participants Nationally representative sample of adults aged 50 years and older. Main outcome measures We present achievement against key indicators of health system performance across effectiveness, cost, access, patient-centredness and equity domains. Results We found areas of poor performance in prevention and management of chronic conditions, such as hypertension control and cancer screening coverage. We also found that cost remains a barrier to healthcare access in spite of insurance schemes. Finally, we found evidence of disparities across many indicators, particularly in the effectiveness and patient centredness domains. Conclusions These findings identify important focus areas for action and shared learning as these countries move towards achieving universal health coverage. PMID:28895493

  19. Student science achievement and the integration of Indigenous knowledge on standardized tests

    NASA Astrophysics Data System (ADS)

    Dupuis, Juliann; Abrams, Eleanor

    2017-09-01

    In this article, we examine how American Indian students in Montana performed on standardized state science assessments when a small number of test items based upon traditional science knowledge from a cultural curriculum, "Indian Education for All", were included. Montana is the first state in the US to mandate the use of a culturally relevant curriculum in all schools and to incorporate this curriculum into a portion of the standardized assessment items. This study compares White and American Indian student test scores on these particular test items to determine how White and American Indian students perform on culturally relevant test items compared to traditional standard science test items. The connections between student achievement on adapted culturally relevant science test items versus traditional items brings valuable insights to the fields of science education, research on student assessments, and Indigenous studies.

  20. Uniform task level definitions for robotic system performance comparisons

    NASA Technical Reports Server (NTRS)

    Price, Charles; Tesar, Delbert

    1989-01-01

    A series of ten task levels of increasing difficulty was compiled for use in comparative performance evaluations of available and future robotics technology. Each level has a breakdown of ten additional levels of difficulty to provide a layering of 100 levels. It is assumed that each level of task performance must be achieved by the system before it can be appropriately considered for the next level.

  1. The GRE Subject Test Performance of U.S. and Non-U.S. Examinees, 1982-84: A Comparative Analysis.

    ERIC Educational Resources Information Center

    Wilson, Kenneth M.

    The Graduate Record Examination (GRE) subject-matter achievement tests are offered in 17 fields. This study investigated the performance of U.S. and non-U.S. citizens on the Subject Tests, and the relationship of selected English-proficiency-related background variables to the test performance of non-U.S. citizens. It was also concerned with…

  2. Autorefraction Versus Manifest Refraction in Patients With Keratoconus.

    PubMed

    Soeters, Nienke; Muijzer, Marc B; Molenaar, Jurrian; Godefrooij, Daniel A; Wisse, Robert P L

    2018-01-01

    To compare visual performance using autorefraction and manifest refraction assessments in patients with keratoconus and investigate whether autorefraction measurements lead to suboptimal visual performance. Corrected distance visual acuity (CDVA) was measured in 90 eyes of 61 patients with keratoconus with both autorefraction and manifest refraction, in a random order. Maximum keratometry (Kmax), cone location, and wavefront aberration were determined with Scheimpflug tomography. The difference between the autorefraction and manifest refraction outcomes was converted to vectors and a multivariable analysis was performed to identify potential underlying causes of this difference. A significantly better CDVA was achieved with manifest refraction (0.06 vs 0.29 logMAR [20/23 vs 20/38 Snellen], P < .001). After vector analysis, a mean difference of 4.83 diopters was found between autorefraction and manifest refraction. Increased Kmax was strongly and significantly associated with better visual performance of manifest refraction compared to autorefraction (B = 0.496, P = .002). This study showed that a superior CDVA is achieved with manifest refraction compared to autorefraction in patients with keratoconus. Furthermore, the difference between the two refraction methods increases as the cornea steepens. According to this study, autorefraction is unreliable in patients with keratoconus and should be avoided. [J Refract Surg. 2018;34(1):30-34.]. Copyright 2018, SLACK Incorporated.

  3. Comparative performance evaluation of full-scale anaerobic and aerobic wastewater treatment processes in Brazil.

    PubMed

    von Sperling, M; Oliveira, S C

    2009-01-01

    This article evaluates and compares the actual behavior of 166 full-scale anaerobic and aerobic wastewater treatment plants in operation in Brazil, providing information on the performance of the processes in terms of the quality of the generated effluent and the removal efficiency achieved. The observed results of effluent concentrations and removal efficiencies of the constituents BOD, COD, TSS (total suspended solids), TN (total nitrogen), TP (total phosphorus) and FC (faecal or thermotolerant coliforms) have been compared with the typical expected performance reported in the literature. The treatment technologies selected for study were: (a) predominantly anaerobic: (i) septic tank + anaerobic filter (ST + AF), (ii) UASB reactor without post-treatment (UASB) and (iii) UASB reactor followed by several post-treatment processes (UASB + POST); (b) predominantly aerobic: (iv) facultative pond (FP), (v) anaerobic pond followed by facultative pond (AP + FP) and (vi) activated sludge (AS). The results, confirmed by statistical tests, showed that, in general, the best performance was achieved by AS, but closely followed by UASB reactor, when operating with any kind of post-treatment. The effluent quality of the anaerobic processes ST + AF and UASB reactor without post-treatment was very similar to the one presented by facultative pond, a simpler aerobic process, regarding organic matter.

  4. Low birth weight young adults: quality of life, academic achievements and social functioning.

    PubMed

    Odberg, Morten Duus; Elgen, Irene Bircow

    2011-02-01

    To compare the quality of life (QOL), academic achievements and social functioning of 134 non-handicapped low birth weight (LBW, birth weight < 2000 g) and 135 normal birth weight (NBW, birth weight > 3000 g) young adults. Population-based longitudinal follow-up study. The Norwegian version of the originally US child health questionnaire, child form 87 (CHQ-CF87), a generic health instrument was applied to measure different physical and psychosocial concepts of QOL. Questionnaires and semi-structured interviews were applied to the cohort to register different aspects of social functioning and academic performance. The LBW group reported well-being in the different aspects of QOL. The LBW group was socially well functioning. The college attendance was similar in the two groups, but more LBW young adults had dropped out of school or attended individually adjusted classes. Performance in mathematics for the LBW women attending academic college was lower. With this exception, the academic performance was comparable in the two groups. Except a somewhat higher rate of school dropouts, the overall outcome of school performance, QOL and social functioning in the LBW young adults was comparable to that of the NBW control group. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

  5. Removed from the List: A Comparative Longitudinal Case Study of a Reconstitution-Eligible School.

    ERIC Educational Resources Information Center

    Mac Iver, Douglas J.; Ruby, Allen; Balfanz, Robert; Byrnes, Vaughan

    2002-01-01

    Longitudinal case study of reform efforts centering on the Talent Development Middle School model at low-performing, high-poverty middle school in Philadelphia. Finds that student gains in mathematics, science, and reading achievement at subject school exceeded that of students in comparable school. (Contains 19 references.) (PKP)

  6. A Comparative Analysis of Learning Styles and Teaching Styles of Mathematics Students and Instructors.

    ERIC Educational Resources Information Center

    Raines, Roy H.

    Mathematics students at the community college level have continually experienced a relatively low achievement rate when compared to their performance in other subjects. Most of the instructional strategies encountered by these students consist of the lecture-discussion-demonstration format, with no allowances made for individual difference except…

  7. Aspects of Solvent Chemistry for Calcium Hydroxide Medicaments

    PubMed Central

    Athanassiadis, Basil

    2017-01-01

    Calcium hydroxide pastes have been used in endodontics since 1947. Most current calcium hydroxide endodontic pastes use water as the vehicle, which limits the dissolution of calcium hydroxide that can be achieved and, thereby, the maximum pH that can be achieved within the root canal system. Using polyethylene glycol as a solvent, rather than water, can achieve an increase in hydroxyl ions release compared to water or saline. By adopting non-aqueous solvents such as the polyethylene glycols (PEG), greater dissolution and faster hydroxyl ion release can be achieved, leading to enhanced antimicrobial actions, and other improvements in performance and biocompatibility. PMID:29065542

  8. The optimal dissolved oxygen profile in a nitrifying activated sludge process - comparisons with ammonium feedback control.

    PubMed

    Amand, L; Carlsson, B

    2013-01-01

    Ammonium feedback control is increasingly used to determine the dissolved oxygen (DO) set-point in aerated activated sludge processes for nitrogen removal. This study compares proportional-integral (PI) ammonium feedback control with a DO profile created from a mathematical minimisation of the daily air flow rate. All simulated scenarios are set to reach the same treatment level of ammonium, based on a daily average concentration. The influent includes daily variations only and the model has three aerated zones. Comparisons are made at different plant loads and DO concentrations, and the placement of the ammonium sensor is investigated. The results show that ammonium PI control can achieve the best performance if the DO set-point is limited at a maximum value and with little integral action in the controller. Compared with constant DO control the best-performing ammonium controller can achieve 1-3.5% savings in the air flow rate, while the optimal solution can achieve a 3-7% saving. Energy savings are larger when operating at higher DO concentrations.

  9. Academic performance and self-regulatory skills in elite youth soccer players.

    PubMed

    Jonker, Laura; Elferink-Gemser, Marije T; Toering, Tynke T; Lyons, James; Visscher, Chris

    2010-12-01

    Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12-16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.

  10. A Systematic Review of Longitudinal Studies of Mathematics Difficulty.

    PubMed

    Nelson, Gena; Powell, Sarah R

    2017-06-01

    Some students may be diagnosed with a learning disability in mathematics or dyscalculia, whereas other students may demonstrate below-grade-level mathematics performance without a disability diagnosis. In the literature, researchers often identify students in both groups as experiencing math difficulty. To understand the performance of students with math difficulty, we examined 35 studies that reported longitudinal results of mathematics achievement (i.e., mathematics performance measured across at least a 12-month span). Our primary goal was to conduct a systematic review of these studies and to understand whether the growth of students with math difficulty was comparable or stagnant when compared with that of students without math difficulty. We also analyzed whether identification of math difficulty was predictive of mathematics achievement in later grades and whether a diagnosis of math difficulty was stable across grade levels. Results indicate that students with math difficulty demonstrate growth on mathematics measures, but this growth still leads to lower performance than that of students without math difficulty. Identification of math difficulty is strongly related to math performance in subsequent grades, and this diagnosis is often stable. Collectively, this literature indicates that students with math difficulty continue to struggle with mathematics in later grades.

  11. The Effects of Resilience in Learning Variables on Mathematical Literacy Performance: A Study of Learning Characteristics of the Academic Resilient and Advantaged Low Achievers in Shanghai, Singapore, Hong Kong, Taiwan and Korea

    ERIC Educational Resources Information Center

    Cheung, Kwok-Cheung

    2017-01-01

    Many students from disadvantaged homes participating in Programme for International Student Assessment (PISA) 2012 were classified as academic resilient (called "disadvantaged high achiever", the DHA in this study). In comparison with peers of comparable home background status, there were also students from advantaged homes performing…

  12. Role of fin material and nanofluid in performance enhancement of automobile radiator

    NASA Astrophysics Data System (ADS)

    Jadar, Raju; Shashishekar, K. S.; Channa Keshava Naik, N.

    2018-04-01

    An effective cooling system can avoid engine and its components from overheating and helps in achieving optimum engine performance. This work deals with the fabrication and performance evaluation of an automobile radiator with i) Aluminum fins and ii) Al-MWCNT fins using 0.1 w/v% f-MWCNT nanofluid. F-MWCNT nanoparticles in the base fluid improves the rate of heat transfer in an automobile radiator integrated with Al-MWCNT fins. The enhancement of heat transfer mainly depends on the quantity of F-MWCNT nanoparticles added to the host fluid. During the study it was found that at a low weight by volume concentration of nanofluid the heat transfer enhancement of 8% was achieved using Al-MWCNT fins compared to base fluid.

  13. The Effect of Moderate and High-Intensity Fatigue on Groundstroke Accuracy in Expert and Non-Expert Tennis Players

    PubMed Central

    Lyons, Mark; Al-Nakeeb, Yahya; Hankey, Joanne; Nevill, Alan

    2013-01-01

    Exploring the effects of fatigue on skilled performance in tennis presents a significant challenge to the researcher with respect to ecological validity. This study examined the effects of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players. The research also explored whether the effects of fatigue are the same regardless of gender and player’s achievement motivation characteristics. 13 expert (7 male, 6 female) and 17 non-expert (13 male, 4 female) tennis players participated in the study. Groundstroke accuracy was assessed using the modified Loughborough Tennis Skills Test. Fatigue was induced using the Loughborough Intermittent Tennis Test with moderate (70%) and high-intensities (90%) set as a percentage of peak heart rate (attained during a tennis-specific maximal hitting sprint test). Ratings of perceived exertion were used as an adjunct to the monitoring of heart rate. Achievement goal indicators for each player were assessed using the 2 x 2 Achievement Goals Questionnaire for Sport in an effort to examine if this personality characteristic provides insight into how players perform under moderate and high-intensity fatigue conditions. A series of mixed ANOVA’s revealed significant fatigue effects on groundstroke accuracy regardless of expertise. The expert players however, maintained better groundstroke accuracy across all conditions compared to the novice players. Nevertheless, in both groups, performance following high-intensity fatigue deteriorated compared to performance at rest and performance while moderately fatigued. Groundstroke accuracy under moderate levels of fatigue was equivalent to that at rest. Fatigue effects were also similar regardless of gender. No fatigue by expertise, or fatigue by gender interactions were found. Fatigue effects were also equivalent regardless of player’s achievement goal indicators. Future research is required to explore the effects of fatigue on performance in tennis using ecologically valid designs that mimic more closely the demands of match play. Key Points Groundstroke accuracy under moderate-intensity fatigue is equivalent to performance at rest. Groundstroke accuracy declines significantly in both expert (40.3% decline) and non-expert (49.6%) tennis players following high-intensity fatigue. Expert players are more consistent, hit more accurate shots and fewer out shots across all fatigue intensities. The effects of fatigue on groundstroke accuracy are the same regardless of gender and player’s achievement goal indicators. PMID:24149809

  14. No Country Left Behind: Rhetoric and Reality of International Large-Scale Assessment. William H. Angoff Memorial Lecture Series

    ERIC Educational Resources Information Center

    Feuer, Michael J.

    2011-01-01

    Few arguments about education are as effective at galvanizing public attention and motivating political action as those that compare the performance of students with their counterparts in other countries and that connect academic achievement to economic performance. Because data from international large-scale assessments (ILSA) have a powerful…

  15. Mathematics Motivation, Anxiety, and Performance in Female Deaf/Hard-of-Hearing and Hearing Students

    ERIC Educational Resources Information Center

    Ariapooran, Saeed

    2017-01-01

    Hearing loss can be a major detriment to academic achievement among students. The present comparative study examines the differences in mathematics motivation, anxiety, and performance in female students with hearing loss and their hearing peers. A total of 63 female students with hearing loss (deaf and hard-of-hearing) and 63 hearing female…

  16. 34 CFR 200.88 - Exclusion of supplemental State and local funds from supplement, not supplant and comparability...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... EDUCATION TITLE I-IMPROVING THE ACADEMIC ACHIEVEMENT OF THE DISADVANTAGED Migrant Education Program § 200.88... migratory children, as defined in section 1309 of the ESEA. (2) The program is based on performance targets... these requirements. (4) The grantee monitors program performance to ensure that these requirements are...

  17. The Performance of Latinos in Rural Public Schools: A Comparative Analysis of Test Scores in Grades 3, 6, and 12.

    ERIC Educational Resources Information Center

    Hampton, Steve; And Others

    1995-01-01

    Examines effects of socioeconomic status, school funding, English proficiency, and Latino population concentration on achievement scores of students in grades 3, 6, and 12 in 66 rural California school districts. Performance on the California Assessment Program was predicted primarily by parental socioeconomic status, and, unexpectedly, improved…

  18. HPF Implementation of ARC3D

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Yan, Jerry

    1999-01-01

    We present an HPF (High Performance Fortran) implementation of ARC3D code along with the profiling and performance data on SGI Origin 2000. Advantages and limitations of HPF as a parallel programming language for CFD applications are discussed. For achieving good performance results we used the data distributions optimized for implementation of implicit and explicit operators of the solver and boundary conditions. We compare the results with MPI and directive based implementations.

  19. The Normalized-Rate Iterative Algorithm: A Practical Dynamic Spectrum Management Method for DSL

    NASA Astrophysics Data System (ADS)

    Statovci, Driton; Nordström, Tomas; Nilsson, Rickard

    2006-12-01

    We present a practical solution for dynamic spectrum management (DSM) in digital subscriber line systems: the normalized-rate iterative algorithm (NRIA). Supported by a novel optimization problem formulation, the NRIA is the only DSM algorithm that jointly addresses spectrum balancing for frequency division duplexing systems and power allocation for the users sharing a common cable bundle. With a focus on being implementable rather than obtaining the highest possible theoretical performance, the NRIA is designed to efficiently solve the DSM optimization problem with the operators' business models in mind. This is achieved with the help of two types of parameters: the desired network asymmetry and the desired user priorities. The NRIA is a centralized DSM algorithm based on the iterative water-filling algorithm (IWFA) for finding efficient power allocations, but extends the IWFA by finding the achievable bitrates and by optimizing the bandplan. It is compared with three other DSM proposals: the IWFA, the optimal spectrum balancing algorithm (OSBA), and the bidirectional IWFA (bi-IWFA). We show that the NRIA achieves better bitrate performance than the IWFA and the bi-IWFA. It can even achieve performance almost as good as the OSBA, but with dramatically lower requirements on complexity. Additionally, the NRIA can achieve bitrate combinations that cannot be supported by any other DSM algorithm.

  20. Fault detection and multiclassifier fusion for unmanned aerial vehicles (UAVs)

    NASA Astrophysics Data System (ADS)

    Yan, Weizhong

    2001-03-01

    UAVs demand more accurate fault accommodation for their mission manager and vehicle control system in order to achieve a reliability level that is comparable to that of a pilot aircraft. This paper attempts to apply multi-classifier fusion techniques to achieve the necessary performance of the fault detection function for the Lockheed Martin Skunk Works (LMSW) UAV Mission Manager. Three different classifiers that meet the design requirements of the fault detection of the UAAV are employed. The binary decision outputs from the classifiers are then aggregated using three different classifier fusion schemes, namely, majority vote, weighted majority vote, and Naieve Bayes combination. All of the three schemes are simple and need no retraining. The three fusion schemes (except the majority vote that gives an average performance of the three classifiers) show the classification performance that is better than or equal to that of the best individual. The unavoidable correlation between the classifiers with binary outputs is observed in this study. We conclude that it is the correlation between the classifiers that limits the fusion schemes to achieve an even better performance.

  1. Accelerating large-scale simulation of seismic wave propagation by multi-GPUs and three-dimensional domain decomposition

    NASA Astrophysics Data System (ADS)

    Okamoto, Taro; Takenaka, Hiroshi; Nakamura, Takeshi; Aoki, Takayuki

    2010-12-01

    We adopted the GPU (graphics processing unit) to accelerate the large-scale finite-difference simulation of seismic wave propagation. The simulation can benefit from the high-memory bandwidth of GPU because it is a "memory intensive" problem. In a single-GPU case we achieved a performance of about 56 GFlops, which was about 45-fold faster than that achieved by a single core of the host central processing unit (CPU). We confirmed that the optimized use of fast shared memory and registers were essential for performance. In the multi-GPU case with three-dimensional domain decomposition, the non-contiguous memory alignment in the ghost zones was found to impose quite long time in data transfer between GPU and the host node. This problem was solved by using contiguous memory buffers for ghost zones. We achieved a performance of about 2.2 TFlops by using 120 GPUs and 330 GB of total memory: nearly (or more than) 2200 cores of host CPUs would be required to achieve the same performance. The weak scaling was nearly proportional to the number of GPUs. We therefore conclude that GPU computing for large-scale simulation of seismic wave propagation is a promising approach as a faster simulation is possible with reduced computational resources compared to CPUs.

  2. How Well Do U.S. High School Students Achieve in Spanish When Compared to Native Spanish Speakers?

    ERIC Educational Resources Information Center

    Sparks, Richard L.; Luebbers, Julie; Castañeda, Martha E.

    2017-01-01

    Foreign language educators have developed measures to assess the proficiency of U.S. high school learners. Most have compared language learners to clearly defined criteria for proficiency in the language (criterion-referenced assessment) or to the performance of other monolingual English speakers (norm-referenced assessment). In this study, the…

  3. The Relationship between Music Participation and Mathematics Achievement in Middle School Students

    ERIC Educational Resources Information Center

    Boyd, Joshua Robert

    2013-01-01

    A comparative analysis was used to study the results from a descriptive survey of selected middle school students in Grades 6, 7, and 8. Student responses to the survey tool was used to compare multiple variables of music participation and duration of various musical activities, such as singing and performing on instruments, to the mathematics…

  4. Design of a prototype position actuator for the primary mirror segments of the European Extremely Large Telescope

    NASA Astrophysics Data System (ADS)

    Jiménez, A.; Morante, E.; Viera, T.; Núñez, M.; Reyes, M.

    2010-07-01

    European Extremely Large Telescope (E-ELT) based in 984 primary mirror segments achieving required optical performance; they must position relatively to adjacent segments with relative nanometer accuracy. CESA designed M1 Position Actuators (PACT) to comply with demanding performance requirements of EELT. Three PACT are located under each segment controlling three out of the plane degrees of freedom (tip, tilt, piston). To achieve a high linear accuracy in long operational displacements, PACT uses two stages in series. First stage based on Voice Coil Actuator (VCA) to achieve high accuracies in very short travel ranges, while second stage based on Brushless DC Motor (BLDC) provides large stroke ranges and allows positioning the first stage closer to the demanded position. A BLDC motor is used achieving a continuous smoothly movement compared to sudden jumps of a stepper. A gear box attached to the motor allows a high reduction of power consumption and provides a great challenge for sizing. PACT space envelope was reduced by means of two flat springs fixed to VCA. Its main characteristic is a low linear axial stiffness. To achieve best performance for PACT, sensors have been included in both stages. A rotary encoder is included in BLDC stage to close position/velocity control loop. An incremental optical encoder measures PACT travel range with relative nanometer accuracy and used to close the position loop of the whole actuator movement. For this purpose, four different optical sensors with different gratings will be evaluated. Control strategy show different internal closed loops that work together to achieve required performance.

  5. Single shaft automotive gas turbine engine characterization test

    NASA Technical Reports Server (NTRS)

    Johnson, R. A.

    1979-01-01

    An automotive gas turbine incorporating a single stage centrifugal compressor and a single stage radial inflow turbine is described. Among the engine's features is the use of wide range variable geometry at the inlet guide vanes, the compressor diffuser vanes, and the turbine inlet vanes to achieve improved part load fuel economy. The engine was tested to determine its performance in both the variable geometry and equivalent fixed geometry modes. Testing was conducted without the originally designed recuperator. Test results were compared with the predicted performance of the nonrecuperative engine based on existing component rig test maps. Agreement between test results and the computer model was achieved.

  6. Key frame extraction based on spatiotemporal motion trajectory

    NASA Astrophysics Data System (ADS)

    Zhang, Yunzuo; Tao, Ran; Zhang, Feng

    2015-05-01

    Spatiotemporal motion trajectory can accurately reflect the changes of motion state. Motivated by this observation, this letter proposes a method for key frame extraction based on motion trajectory on the spatiotemporal slice. Different from the well-known motion related methods, the proposed method utilizes the inflexions of the motion trajectory on the spatiotemporal slice of all the moving objects. Experimental results show that although a similar performance is achieved in the single-objective screen, by comparing the proposed method to that achieved with the state-of-the-art methods based on motion energy or acceleration, the proposed method shows a better performance in a multiobjective video.

  7. Rural and urban transit district benchmarking : effectiveness and efficiency guidance document.

    DOT National Transportation Integrated Search

    2011-05-01

    Rural and urban transit systems have sought ways to compare performance across agencies, : identifying successful service delivery strategies and applying these concepts to achieve : successful results within their agency. Benchmarking is a method us...

  8. Short progressive muscle relaxation or motor coordination training does not increase performance in a brain-computer interface based on sensorimotor rhythms (SMR).

    PubMed

    Botrel, L; Acqualagna, L; Blankertz, B; Kübler, A

    2017-11-01

    Brain computer interfaces (BCIs) allow for controlling devices through modulation of sensorimotor rhythms (SMR), yet a profound number of users is unable to achieve sufficient accuracy. Here, we investigated if visuo-motor coordination (VMC) training or Jacobsen's progressive muscle relaxation (PMR) prior to BCI use would increase later performance compared to a control group who performed a reading task (CG). Running the study in two different BCI-labs, we achieved a joint sample size of N=154 naïve participants. No significant effect of either intervention (VMC, PMR, control) was found on resulting BCI performance. Relaxation level and visuo-motor performance were associated with later BCI performance in one BCI-lab but not in the other. These mixed results do not indicate a strong potential of VMC or PMR for boosting performance. Yet further research with different training parameters or experimental designs is needed to complete the picture. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Ultra compact spectrometer using linear variable filters

    NASA Astrophysics Data System (ADS)

    Dami, M.; De Vidi, R.; Aroldi, G.; Belli, F.; Chicarella, L.; Piegari, A.; Sytchkova, A.; Bulir, J.; Lemarquis, F.; Lequime, M.; Abel Tibérini, L.; Harnisch, B.

    2017-11-01

    The Linearly Variable Filters (LVF) are complex optical devices that, integrated in a CCD, can realize a "single chip spectrometer". In the framework of an ESA Study, a team of industries and institutes led by SELEX-Galileo explored the design principles and manufacturing techniques, realizing and characterizing LVF samples based both on All-Dielectric (AD) and Metal-Dielectric (MD) Coating Structures in the VNIR and SWIR spectral ranges. In particular the achieved performances on spectral gradient, transmission bandwidth and Spectral Attenuation (SA) are presented and critically discussed. Potential improvements will be highlighted. In addition the results of a feasibility study of a SWIR Linear Variable Filter are presented with the comparison of design prediction and measured performances. Finally criticalities related to the filter-CCD packaging are discussed. The main achievements reached during these activities have been: - to evaluate by design, manufacturing and test of LVF samples the achievable performances compared with target requirements; - to evaluate the reliability of the projects by analyzing their repeatability; - to define suitable measurement methodologies

  10. Achieving High Resolution Ion Mobility Separations Using Traveling Waves in Compact Multiturn Structures for Lossless Ion Manipulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hamid, Ahmed M.; Garimella, Sandilya V. B.; Ibrahim, Yehia M.

    We report on ion mobility separations (IMS) achievable using traveling waves in a Structures for Lossless Ion Manipulations (TW-SLIM) module having a 44-cm path length and sixteen 90º turns. The performance of the TW-SLIM module was evaluated for ion transmission, and ion mobility separations with different RF, TW parameters and SLIM surface gaps in conjunction with mass spectrometry. In this work TWs were created by the transient and dynamic application of DC potentials. The TW-SLIM module demonstrated highly robust performance and the ion mobility resolution achieved even with sixteen close spaced turns was comparable to a similar straight path TW-SLIMmore » module. We found an ion mobility peak capacity of ~ 31 and peak generation rate of 780 s-1 for TW speeds of <210 m/s using the current multi-turn TW-SLIM module. The separations achieved for isomers of peptides and tetrasaccharides were found to be comparable to those from a ~ 0.9-m drift tube-based IMS-MS platform operated at the same pressure (4 torr). The combined attributes of flexible design, low voltage requirements and lossless ion transmission through multiple turns for the present TW-SLIM module provides a basis for SLIM devices capable of achieving much greater ion mobility resolutions via greatly extended ion path lengths and compact serpentine designs that do not significantly impact the instrumentation profile, a direction described in a companion manuscript.« less

  11. Three-dimensional texture analysis of contrast enhanced CT images for treatment response assessment in Hodgkin lymphoma: Comparison with F-18-FDG PET

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Knogler, Thomas; El-Rabadi, Karem; Weber, Michael

    2014-12-15

    Purpose: To determine the diagnostic performance of three-dimensional (3D) texture analysis (TA) of contrast-enhanced computed tomography (CE-CT) images for treatment response assessment in patients with Hodgkin lymphoma (HL), compared with F-18-fludeoxyglucose (FDG) positron emission tomography/CT. Methods: 3D TA of 48 lymph nodes in 29 patients was performed on venous-phase CE-CT images before and after chemotherapy. All lymph nodes showed pathologically elevated FDG uptake at baseline. A stepwise logistic regression with forward selection was performed to identify classic CT parameters and texture features (TF) that enable the separation of complete response (CR) and persistent disease. Results: The TF fraction of imagemore » in runs, calculated for the 45° direction, was able to correctly identify CR with an accuracy of 75%, a sensitivity of 79.3%, and a specificity of 68.4%. Classical CT features achieved an accuracy of 75%, a sensitivity of 86.2%, and a specificity of 57.9%, whereas the combination of TF and CT imaging achieved an accuracy of 83.3%, a sensitivity of 86.2%, and a specificity of 78.9%. Conclusions: 3D TA of CE-CT images is potentially useful to identify nodal residual disease in HL, with a performance comparable to that of classical CT parameters. Best results are achieved when TA and classical CT features are combined.« less

  12. Problematic projection to the in-sample subspace for a kernelized anomaly detector

    DOE PAGES

    Theiler, James; Grosklos, Guen

    2016-03-07

    We examine the properties and performance of kernelized anomaly detectors, with an emphasis on the Mahalanobis-distance-based kernel RX (KRX) algorithm. Although the detector generally performs well for high-bandwidth Gaussian kernels, it exhibits problematic (in some cases, catastrophic) performance for distances that are large compared to the bandwidth. By comparing KRX to two other anomaly detectors, we can trace the problem to a projection in feature space, which arises when a pseudoinverse is used on the covariance matrix in that feature space. Here, we show that a regularized variant of KRX overcomes this difficulty and achieves superior performance over a widemore » range of bandwidths.« less

  13. Self-concept mediates the relation between achievement and emotions in mathematics.

    PubMed

    Van der Beek, Jojanneke P J; Van der Ven, Sanne H G; Kroesbergen, Evelyn H; Leseman, Paul P M

    2017-09-01

    Mathematics achievement is related to positive and negative emotions. Pekrun's control-value theory of achievement emotions suggests that students' self-concept (i.e., self-appraisal of ability) may be an important mediator of the relation between mathematics achievement and emotions. The aims were (1) to investigate the mediating role of mathematical self-concept in the relation between mathematics achievement and the achievement emotions of enjoyment and anxiety in a comprehensive model, and (2) to test possible differences in this mediating role between low-, average-, and high-achieving students. Participants were ninth-grade students (n = 1,014) from eight secondary schools in the Netherlands. Through an online survey including mathematical problems, students were asked to indicate their levels of mathematics enjoyment, anxiety, and self-concept. Structural equation modelling was used to test the mediating role of self-concept in the relation between mathematics achievement and emotions. Multigroup analyses were performed to compare these relations across the three achievement groups. Results confirmed full mediation of the relation between mathematics achievement and emotions by mathematical self-concept. Furthermore, we found higher self-concepts, more enjoyment and less math anxiety in high-achieving students compared to their average and low-achieving peers. No differences across these achievement groups were found in the relations in the mediational model. Mathematical self-concept plays a pivotal role in students' appraisal of mathematics. Mathematics achievement is only one factor explaining students' self-concept. Likely also classroom instruction and teachers' feedback strategies help to shape students' self-concept. © 2017 The British Psychological Society.

  14. Representation and alignment of sung queries for music information retrieval

    NASA Astrophysics Data System (ADS)

    Adams, Norman H.; Wakefield, Gregory H.

    2005-09-01

    The pursuit of robust and rapid query-by-humming systems, which search melodic databases using sung queries, is a common theme in music information retrieval. The retrieval aspect of this database problem has received considerable attention, whereas the front-end processing of sung queries and the data structure to represent melodies has been based on musical intuition and historical momentum. The present work explores three time series representations for sung queries: a sequence of notes, a ``smooth'' pitch contour, and a sequence of pitch histograms. The performance of the three representations is compared using a collection of naturally sung queries. It is found that the most robust performance is achieved by the representation with highest dimension, the smooth pitch contour, but that this representation presents a formidable computational burden. For all three representations, it is necessary to align the query and target in order to achieve robust performance. The computational cost of the alignment is quadratic, hence it is necessary to keep the dimension small for rapid retrieval. Accordingly, iterative deepening is employed to achieve both robust performance and rapid retrieval. Finally, the conventional iterative framework is expanded to adapt the alignment constraints based on previous iterations, further expediting retrieval without degrading performance.

  15. Multiple access capacity trade-offs for a Ka-band personal access satellite system

    NASA Technical Reports Server (NTRS)

    Dessouky, Khaled; Motamedi, Masoud

    1990-01-01

    System capability is critical to the economic viability of a personal satellite communication system. Ka band has significant potential to support a high capacity multiple access system because of the availability of bandwidth. System design tradeoffs are performed and multiple access schemes are compared with the design goal of achieving the highest capacity and efficiency. Conclusions regarding the efficiency of the different schemes and the achievable capacities are given.

  16. Achievement Gap Patterns of Grade 8 American Indian and Alaska Native Students in Reading and Math. Issues & Answers. REL 2009-No. 073

    ERIC Educational Resources Information Center

    Nelson, Steven; Greenough, Richard; Sage, Nicole

    2009-01-01

    Focusing on student proficiency in reading and math from 2003-04 to 2006-07, this report compares gaps in performance on state achievement tests between grade 8 American Indian and Alaska Native students and all other grade 8 students in 26 states serving large populations of American Indian and Alaska Native students. In response to a request by…

  17. Introductory anatomy and physiology in an undergraduate nursing curriculum.

    PubMed

    Brown, S J; White, S; Power, N

    2017-03-01

    Using an educational data mining approach, first-year academic achievement of undergraduate nursing students, which included two compulsory courses in introductory human anatomy and physiology, was compared with achievement in a final semester course that transitioned students into the workplace. We hypothesized that students could be grouped according to their first-year academic achievement using a two-step cluster analysis method and that grades achieved in the human anatomy and physiology courses would be strong predictors of overall achievement. One cohort that graduated in 2014 (n = 105) and one that graduated in 2015 (n = 94) were analyzed separately, and for both cohorts, two groups were identified, these being "high achievers" (HIGH) and "low achievers" (LOW). Consistently, the anatomy and physiology courses were the strongest predictors of group assignment, such that a good grade in these was much more likely to put a student into a high-achieving group. Students in the HIGH groups also scored higher in the Transition to Nursing course when compared with students in the LOW groups. The higher predictor importance of the anatomy and physiology courses suggested that if a first-year grade-point average was calculated for students, an increased weighting should be attributed to these courses. Identifying high-achieving students based on first-year academic scores may be a useful method to predict future academic performance. Copyright © 2017 the American Physiological Society.

  18. Rapid response to vedolizumab therapy in biologic-naïve patients with inflammatory bowel diseases.

    PubMed

    Feagan, Brian G; Lasch, Karen; Lissoos, Trevor; Cao, Charlie; Wojtowicz, Abigail M; Khalid, Javaria Mona; Colombel, Jean-Frédéric

    2018-05-29

    Vedolizumab, a humanized monoclonal antibody against α4β7 integrin, is used to treat adults with moderately to severely active ulcerative colitis (UC) and Crohn's disease (CD). We investigated the time course of clinical response to vedolizumab in patients who were and were not previously treated with tumor necrosis factor (TNF) antagonists. We performed a post-hoc analysis of data from phase 3, randomized, controlled trials of vedolizumab vs placebo in adult patients with UC (n=374) or CD (n=784). We collected data on patient-reported symptoms (rectal bleeding and stool frequency for patients with UC, abdominal pain and loose stool frequency for patients with CD) reported at weeks 2, 4, and 6 of treatment. We reported mean percentage score changes from baseline and proportions of patients who achieved predefined scores. We performed multivariate logistic regression analysis to identify factors associated with an early response (at week 2). In patients with UC (overall or naïve to TNF antagonist therapy), a significantly greater percentage of patients given vedolizumab achieved the predefined composite symptom score at weeks 2, 4, and 6 compared to those given placebo. In patients with CD who were naïve to TNF antagonists, a significantly greater percentage of patients given vedolizumab achieved the predefined score at weeks 2 and 4 compared to those given placebo. Among patients with UC given vedolizumab, 19.1% (overall) and 22.3% (TNF antagonist naïve) achieved a composite score of rectal bleeding of 0 and stool frequency ≤1 at week 2 compared to 10% (overall) and 6.6% (TNF antagonist naïve) of those receiving placebo. Among TNF antagonist-naïve patients with CD, 15.0% of those given vedolizumab achieved an average daily composite score of abdominal pain ≤1 and loose stool frequency ≤3 at week 2 (compared to 7.9% given placebo), and 23.8% of those given vedolizumab achieved these by week 4 (compared to 10.3% given placebo). In a post-hoc analysis of data from phase 3 clinical trials, vedolizumab significantly improved patient-reported symptoms of UC and CD as early as week 2 of treatment, continuing through the first 6 weeks-especially when given as first-line biologic therapy. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

  19. The effect of visuals on non-native English students' learning of the basic principles and laws of motion

    NASA Astrophysics Data System (ADS)

    Yang, Quan

    2001-10-01

    This study, involving 154 undergraduate college students in China, was conducted to determine whether the surface structure of visual graphics affect content learning when the learner was a non-native English speaker and learning took place in a non-English speaking environment. Instruction with concrete animated graphics resulted in significantly higher achievement, when compared to instruction with concrete static, abstract static, abstract animated graphics or text only without any graphical illustrations. It was also found, unexpectedly, the text-only instruction resulted in the second best achievement, significantly higher than instruction with concrete static, abstract static, and abstract animated graphics. In addition, there was a significant interaction with treatment and test item, which indicated that treatment effects on graphic-specific items differed from those on definitional items. Additional findings indicated that relation to graphics directly or indirectly from the text that students studied had little impact on their performance in the posttests. Further, 51% of the participants indicated that they relied on some graphical images to answer the test questions and 19% relied heavily on graphics when completing the tests. In conclusion, concrete graphics when combined with animation played a significant role in enhancing ESL student performance and enabled the students to achieve the best learning outcomes as compared to abstract animated, concrete static, and abstract static graphics. This result suggested a significant innovation in the design and development of ESL curriculum in computer-based instruction, which would enable ESL students to perform better and achieve the expected outcomes in content area learning.

  20. Selected Factors in Reading Comprehension for Deaf and Hearing Adults: Phonological Skills and Metacognition.

    PubMed

    Wang, Ye; Silvestri, Julia A; Jahromi, Laudan B

    2018-01-01

    The purpose of the study was to identify factors related to reading comprehension, and to compare similarities and differences in the reading processes of deaf and hearing adults. The sample included four groups, each consisting of 15 adults. The groups were identified as (a) deaf high-achieving readers, (b) deaf low-achieving readers, (c) hearing high-achieving readers, and (d) hearing low-achieving readers. Measurement instruments included a demographic form along with assessments of reading comprehension, phonological skills, and metacognition, the latter of which contained both a making-inferences measure and a think-aloud discussion with a reading strategies checklist. Results indicated that deaf high-achieving readers performed similarly to hearing high-achieving readers, except for phonological skills, and that for all participants, phonological skills and metacognition were related to reading comprehension skills.

  1. A preliminary study of achievement, attitudes toward success in mathematics, and mathematics anxiety with technology-based instruction in brief calculus.

    PubMed

    Alkhateeb, Haitham M

    2002-02-01

    This study was designed to compare achievement, attitudes toward success in mathematics, and mathematics anxiety of college students taught brief calculus using a graphic calculator, with the achievement and attitudes and anxiety of students taught using the computer algebra system Maple, using a technology based text book. 50 men and 50 women, students in three classes at a large public university in the southwestern United States, participated. Students' achievement in brief calculus was measured by performance on a teacher-made achievement test given at the end of the study. Analysis of variance showed no significant difference in achievement between the groups. To measure change in attitudes and anxiety, responses to paper-and-pencil inventories indicated significant differences in favor of students using the computer.

  2. The impact of the healthy schools program on reading, mathematics, and science achievement of 5th grade students: A causal-comparative inquiry

    NASA Astrophysics Data System (ADS)

    Barrera, Christina Lynn

    The obesity rate for children has become a national epidemic in America, resulting in the need to incorporate physical fitness and nutrition into the curriculum in an effort to improve health and academic achievement. The Healthy Schools Program (HSP) is an initiative that assists schools in establishing and sustaining healthy environments, which can be instrumental in making students perform better in school. Therefore, the purpose of the study was to examine the impact of the HSP on academic achievement. (Abstract shortened by ProQuest.).

  3. SU-E-J-128: Two-Stage Atlas Selection in Multi-Atlas-Based Image Segmentation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhao, T; Ruan, D

    2015-06-15

    Purpose: In the new era of big data, multi-atlas-based image segmentation is challenged by heterogeneous atlas quality and high computation burden from extensive atlas collection, demanding efficient identification of the most relevant atlases. This study aims to develop a two-stage atlas selection scheme to achieve computational economy with performance guarantee. Methods: We develop a low-cost fusion set selection scheme by introducing a preliminary selection to trim full atlas collection into an augmented subset, alleviating the need for extensive full-fledged registrations. More specifically, fusion set selection is performed in two successive steps: preliminary selection and refinement. An augmented subset is firstmore » roughly selected from the whole atlas collection with a simple registration scheme and the corresponding preliminary relevance metric; the augmented subset is further refined into the desired fusion set size, using full-fledged registration and the associated relevance metric. The main novelty of this work is the introduction of an inference model to relate the preliminary and refined relevance metrics, based on which the augmented subset size is rigorously derived to ensure the desired atlases survive the preliminary selection with high probability. Results: The performance and complexity of the proposed two-stage atlas selection method were assessed using a collection of 30 prostate MR images. It achieved comparable segmentation accuracy as the conventional one-stage method with full-fledged registration, but significantly reduced computation time to 1/3 (from 30.82 to 11.04 min per segmentation). Compared with alternative one-stage cost-saving approach, the proposed scheme yielded superior performance with mean and medium DSC of (0.83, 0.85) compared to (0.74, 0.78). Conclusion: This work has developed a model-guided two-stage atlas selection scheme to achieve significant cost reduction while guaranteeing high segmentation accuracy. The benefit in both complexity and performance is expected to be most pronounced with large-scale heterogeneous data.« less

  4. A structural SVM approach for reference parsing.

    PubMed

    Zhang, Xiaoli; Zou, Jie; Le, Daniel X; Thoma, George R

    2011-06-09

    Automated extraction of bibliographic data, such as article titles, author names, abstracts, and references is essential to the affordable creation of large citation databases. References, typically appearing at the end of journal articles, can also provide valuable information for extracting other bibliographic data. Therefore, parsing individual reference to extract author, title, journal, year, etc. is sometimes a necessary preprocessing step in building citation-indexing systems. The regular structure in references enables us to consider reference parsing a sequence learning problem and to study structural Support Vector Machine (structural SVM), a newly developed structured learning algorithm on parsing references. In this study, we implemented structural SVM and used two types of contextual features to compare structural SVM with conventional SVM. Both methods achieve above 98% token classification accuracy and above 95% overall chunk-level accuracy for reference parsing. We also compared SVM and structural SVM to Conditional Random Field (CRF). The experimental results show that structural SVM and CRF achieve similar accuracies at token- and chunk-levels. When only basic observation features are used for each token, structural SVM achieves higher performance compared to SVM since it utilizes the contextual label features. However, when the contextual observation features from neighboring tokens are combined, SVM performance improves greatly, and is close to that of structural SVM after adding the second order contextual observation features. The comparison of these two methods with CRF using the same set of binary features show that both structural SVM and CRF perform better than SVM, indicating their stronger sequence learning ability in reference parsing.

  5. Laboratory based instruction in Pakistan: Comparative evaluation of three laboratory instruction methods in biological science at higher secondary school level

    NASA Astrophysics Data System (ADS)

    Cheema, Tabinda Shahid

    This study of laboratory based instruction at higher secondary school level was an attempt to gain some insight into the effectiveness of three laboratory instruction methods: cooperative group instruction method, individualised instruction method and lecture demonstration method on biology achievement and retention. A Randomised subjects, Pre-test Post-test Comparative Methods Design was applied. Three groups of students from a year 11 class in Pakistan conducted experiments using the different laboratory instruction methods. Pre-tests, achievement tests after the experiments and retention tests one month later were administered. Results showed no significant difference between the groups on total achievement and retention, nor was there any significant difference on knowledge and comprehension test scores or skills performance. Future research investigating a similar problem is suggested.

  6. Achieving 10,000 steps: a comparison of public transport users and drivers in a university setting.

    PubMed

    Villanueva, Karen; Giles-Corti, Billie; McCormack, Gavin

    2008-09-01

    To compare pedometer steps of university students who used public transport and private motor vehicles to travel to and or from The University of Western Australia (UWA). 103 undergraduate students in 2006 recruited by e-mail and snowballing wore a pedometer for five consecutive university days, and completed a travel and physical activity diary. Compared with private motor vehicle users, public transport users performed more daily steps (11443 vs. 10242 steps/day, p=0.04) After adjusting for gender, age group and average daily minutes of self-reported leisure-time physical activity, the odds of achieving 10,000 steps/day was higher in public transport users compared with private motor vehicle users (OR 3.55; 95% CI 1.34-9.38, p=0.01). Walking associated with public transport use appeared to contribute to university students achieving higher levels of daily steps. Encouraging public transport use could help increase and maintain community physical activity levels.

  7. A longitudinal examination of the link between youth physical fitness and academic achievement.

    PubMed

    London, Rebecca A; Castrechini, Sebastian

    2011-07-01

    Childhood obesity has been linked with other persistent health problems, but research is just beginning to examine its relationship with academic performance. This article tracks students longitudinally to examine the ways student physical fitness and changes in fitness align with school performance. Using matched administrative data and individual growth modeling, we examine the relationship between academic achievement and overall physical fitness longitudinally from fourth to seventh and sixth to ninth grades for students in a California community. Comparing those who are persistently fit to those who are persistently unfit, we find disparities in both math and English language arts test scores. These academic disparities begin even before students begin fitness testing in fifth grade and are larger for girls and Latinos. Overall physical fitness is a better predictor of academic achievement than obesity as measured by body mass index. Socioeconomic status acts as a buffer for those who have poor physical fitness but strong academic performance. The findings indicate the presence of a physical fitness achievement gap that has consequences for potential students' future educational and health outcomes. This gap begins as early as fourth grade, which is before physical fitness testing begins in California. © 2011, American School Health Association.

  8. Evaluation of winter pothole patching methods.

    DOT National Transportation Integrated Search

    2014-01-01

    The main objective of this study was to evaluate the performance and cost-effectiveness of the tow-behind combination : infrared asphalt heater/reclaimer patching method and compare it to the throw and roll and spray injection methods. To : achieve t...

  9. The Score-Boosting Game.

    ERIC Educational Resources Information Center

    Popham, W. James

    2000-01-01

    Teachers everywhere are playing the score-boosting game to raise scores on mandated standardized achievement tests, although five nationally recognized assessments compare student performance instead of measuring classroom learning. Since curriculum standards are often vague and misaligned with assessments, teachers sprinkle instruction with…

  10. GPU based cloud system for high-performance arrhythmia detection with parallel k-NN algorithm.

    PubMed

    Tae Joon Jun; Hyun Ji Park; Hyuk Yoo; Young-Hak Kim; Daeyoung Kim

    2016-08-01

    In this paper, we propose an GPU based Cloud system for high-performance arrhythmia detection. Pan-Tompkins algorithm is used for QRS detection and we optimized beat classification algorithm with K-Nearest Neighbor (K-NN). To support high performance beat classification on the system, we parallelized beat classification algorithm with CUDA to execute the algorithm on virtualized GPU devices on the Cloud system. MIT-BIH Arrhythmia database is used for validation of the algorithm. The system achieved about 93.5% of detection rate which is comparable to previous researches while our algorithm shows 2.5 times faster execution time compared to CPU only detection algorithm.

  11. A Comparative Case Study of Veteran Superintendent's Leadership and Organizational Processes in Addressing the Academic Achievement of Students in Low Performing School Districts

    ERIC Educational Resources Information Center

    Reimer, Catherine Nicole

    2010-01-01

    This research study investigated the leadership behaviors and organizational frames utilized by two veteran superintendents of medium sized school districts in California to address issues of academic performance in their respective districts as perceived by the superintendents and their respective board members and principals. Current…

  12. LONG TERM STABILITY STUDY AT FNAL AND SLAC USING BINP DEVELOPED HYDROSTATIC LEVEL SYSTEM

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Seryi, Andrei

    2003-05-28

    Long term ground stability is essential for achieving the performance goals of the Next Linear Collider. To characterize ground motion on relevant time scales, measurements have been performed at three geologically different locations using a hydrostatic level system developed specifically for these studies. Comparative results from the different sites are presented in this paper.

  13. Effect of a Cooperative Learning Technique on the Academic Performance of High School Students in Mathematics

    ERIC Educational Resources Information Center

    Idowu, Olumuyiwa Ayodeji

    2013-01-01

    Over the past 2 years, almost 45% of the students attending a local suburban high school failed Algebra 2. The purpose of this study was to compare the impact of a cooperative instructional technique (student teams-achievement divisions [STAD]) to traditional instructional methods on performance in high school algebra. Motivational and cognitive…

  14. A prospective comparison of performance during back-to-back, anterograde manual spiral enteroscopy and double-balloon enteroscopy.

    PubMed

    Despott, Edward J; Murino, Alberto; Bourikas, Leonidas; Nakamura, Masanao; Ramachandra, Vino; Fraser, Chris

    2015-05-01

    Spiral enteroscopy is a recently introduced technology alternative to balloon-assisted enteroscopy for examination of the small bowel. To compare small bowel insertion depths and procedure duration by spiral enteroscopy and double-balloon enteroscopy performed in the same cohort of patients, in immediate succession, using the same method of insertion depth estimation. A prospective, back-to-back comparative study was performed in 15 patients. Spiral enteroscopy procedures were performed first and a tattoo was placed to mark the most distal point. Double-balloon enteroscopy passed the tattoo placed at spiral enteroscopy in 14/15 cases (93%). Median insertion depths for double-balloon enteroscopy and spiral enteroscopy were 265cm and 175cm, respectively (P=0.004). Median time to achieve maximal depth of insertion was significantly shorter for spiral enteroscopy compared with double-balloon enteroscopy (24min vs. 45min, respectively; P=0.0005). However, in 14 patients no differences were found in median time to reach the same insertion depth (P=0.28). Double-balloon enteroscopy achieved significantly greater small bowel insertion depth than spiral enteroscopy. Although overall double-balloon enteroscopy procedure duration was longer, the time taken to reach the same small bowel insertion depth by both spiral enteroscopy and double-balloon enteroscopy was similar. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  15. Optimization of Selected Remote Sensing Algorithms for Embedded NVIDIA Kepler GPU Architecture

    NASA Technical Reports Server (NTRS)

    Riha, Lubomir; Le Moigne, Jacqueline; El-Ghazawi, Tarek

    2015-01-01

    This paper evaluates the potential of embedded Graphic Processing Units in the Nvidias Tegra K1 for onboard processing. The performance is compared to a general purpose multi-core CPU and full fledge GPU accelerator. This study uses two algorithms: Wavelet Spectral Dimension Reduction of Hyperspectral Imagery and Automated Cloud-Cover Assessment (ACCA) Algorithm. Tegra K1 achieved 51 for ACCA algorithm and 20 for the dimension reduction algorithm, as compared to the performance of the high-end 8-core server Intel Xeon CPU with 13.5 times higher power consumption.

  16. Neural-Learning-Based Telerobot Control With Guaranteed Performance.

    PubMed

    Yang, Chenguang; Wang, Xinyu; Cheng, Long; Ma, Hongbin

    2017-10-01

    In this paper, a neural networks (NNs) enhanced telerobot control system is designed and tested on a Baxter robot. Guaranteed performance of the telerobot control system is achieved at both kinematic and dynamic levels. At kinematic level, automatic collision avoidance is achieved by the control design at the kinematic level exploiting the joint space redundancy, thus the human operator would be able to only concentrate on motion of robot's end-effector without concern on possible collision. A posture restoration scheme is also integrated based on a simulated parallel system to enable the manipulator restore back to the natural posture in the absence of obstacles. At dynamic level, adaptive control using radial basis function NNs is developed to compensate for the effect caused by the internal and external uncertainties, e.g., unknown payload. Both the steady state and the transient performance are guaranteed to satisfy a prescribed performance requirement. Comparative experiments have been performed to test the effectiveness and to demonstrate the guaranteed performance of the proposed methods.

  17. The Classroom Performance System (CPS): Effects on student participation, attendance, and achievement in multicultural anatomy and physiology classes at South Texas College

    NASA Astrophysics Data System (ADS)

    Termos, Mohamad Hani

    2011-12-01

    The Classroom Performance System (CPS) is an instructional technology tool that increases student performance and addresses different learning styles. Instructional technologies are used to promote active learning; however, student embarrassment issue in a multicultural setting is not addressed. This study assessed the effect of the CPS on student participation, attendance, and achievement in multicultural college-level anatomy and physiology classes at South Texas College, where the first spoken language is not English. Quantitative method and quasi-experimental design were employed and comparative statistic methods and pre-post tests were used to collect the data. Participants were college students and sections of study were selected by convenient sampling. Participation was 100% during most of the lectures held and participation rate did not strike above 68% in control group. Attendance was significantly higher in CPS sections than the control group as shown by t-tests. Experimental sections had a higher increase in the pre-post test scores and student averages on lecture exams increased at a higher rate as compared to the control group. Therefore, the CPS increased student participation, attendance, and achievement in multicultural anatomy and physiology classes. The CPS can be studied in other settings where the first spoken language is English or in other programs, such as special education programs. Additionally, other variables can be studied and other methodologies can be employed.

  18. Using SRAM Based FPGAs for Power-Aware High Performance Wireless Sensor Networks

    PubMed Central

    Valverde, Juan; Otero, Andres; Lopez, Miguel; Portilla, Jorge; de la Torre, Eduardo; Riesgo, Teresa

    2012-01-01

    While for years traditional wireless sensor nodes have been based on ultra-low power microcontrollers with sufficient but limited computing power, the complexity and number of tasks of today’s applications are constantly increasing. Increasing the node duty cycle is not feasible in all cases, so in many cases more computing power is required. This extra computing power may be achieved by either more powerful microcontrollers, though more power consumption or, in general, any solution capable of accelerating task execution. At this point, the use of hardware based, and in particular FPGA solutions, might appear as a candidate technology, since though power use is higher compared with lower power devices, execution time is reduced, so energy could be reduced overall. In order to demonstrate this, an innovative WSN node architecture is proposed. This architecture is based on a high performance high capacity state-of-the-art FPGA, which combines the advantages of the intrinsic acceleration provided by the parallelism of hardware devices, the use of partial reconfiguration capabilities, as well as a careful power-aware management system, to show that energy savings for certain higher-end applications can be achieved. Finally, comprehensive tests have been done to validate the platform in terms of performance and power consumption, to proof that better energy efficiency compared to processor based solutions can be achieved, for instance, when encryption is imposed by the application requirements. PMID:22736971

  19. Using SRAM based FPGAs for power-aware high performance wireless sensor networks.

    PubMed

    Valverde, Juan; Otero, Andres; Lopez, Miguel; Portilla, Jorge; de la Torre, Eduardo; Riesgo, Teresa

    2012-01-01

    While for years traditional wireless sensor nodes have been based on ultra-low power microcontrollers with sufficient but limited computing power, the complexity and number of tasks of today's applications are constantly increasing. Increasing the node duty cycle is not feasible in all cases, so in many cases more computing power is required. This extra computing power may be achieved by either more powerful microcontrollers, though more power consumption or, in general, any solution capable of accelerating task execution. At this point, the use of hardware based, and in particular FPGA solutions, might appear as a candidate technology, since though power use is higher compared with lower power devices, execution time is reduced, so energy could be reduced overall. In order to demonstrate this, an innovative WSN node architecture is proposed. This architecture is based on a high performance high capacity state-of-the-art FPGA, which combines the advantages of the intrinsic acceleration provided by the parallelism of hardware devices, the use of partial reconfiguration capabilities, as well as a careful power-aware management system, to show that energy savings for certain higher-end applications can be achieved. Finally, comprehensive tests have been done to validate the platform in terms of performance and power consumption, to proof that better energy efficiency compared to processor based solutions can be achieved, for instance, when encryption is imposed by the application requirements.

  20. Concatenated Coding Using Trellis-Coded Modulation

    NASA Technical Reports Server (NTRS)

    Thompson, Michael W.

    1997-01-01

    In the late seventies and early eighties a technique known as Trellis Coded Modulation (TCM) was developed for providing spectrally efficient error correction coding. Instead of adding redundant information in the form of parity bits, redundancy is added at the modulation stage thereby increasing bandwidth efficiency. A digital communications system can be designed to use bandwidth-efficient multilevel/phase modulation such as Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK) or Quadrature Amplitude Modulation (QAM). Performance gain can be achieved by increasing the number of signals over the corresponding uncoded system to compensate for the redundancy introduced by the code. A considerable amount of research and development has been devoted toward developing good TCM codes for severely bandlimited applications. More recently, the use of TCM for satellite and deep space communications applications has received increased attention. This report describes the general approach of using a concatenated coding scheme that features TCM and RS coding. Results have indicated that substantial (6-10 dB) performance gains can be achieved with this approach with comparatively little bandwidth expansion. Since all of the bandwidth expansion is due to the RS code we see that TCM based concatenated coding results in roughly 10-50% bandwidth expansion compared to 70-150% expansion for similar concatenated scheme which use convolution code. We stress that combined coding and modulation optimization is important for achieving performance gains while maintaining spectral efficiency.

  1. Optimized survey design for electrical resistivity tomography: combined optimization of measurement configuration and electrode placement

    NASA Astrophysics Data System (ADS)

    Uhlemann, Sebastian; Wilkinson, Paul B.; Maurer, Hansruedi; Wagner, Florian M.; Johnson, Timothy C.; Chambers, Jonathan E.

    2018-07-01

    Within geoelectrical imaging, the choice of measurement configurations and electrode locations is known to control the image resolution. Previous work has shown that optimized survey designs can provide a model resolution that is superior to standard survey designs. This paper demonstrates a methodology to optimize resolution within a target area, while limiting the number of required electrodes, thereby selecting optimal electrode locations. This is achieved by extending previous work on the `Compare-R' algorithm, which by calculating updates to the resolution matrix optimizes the model resolution in a target area. Here, an additional weighting factor is introduced that allows to preferentially adding measurement configurations that can be acquired on a given set of electrodes. The performance of the optimization is tested on two synthetic examples and verified with a laboratory study. The effect of the weighting factor is investigated using an acquisition layout comprising a single line of electrodes. The results show that an increasing weight decreases the area of improved resolution, but leads to a smaller number of electrode positions. Imaging results superior to a standard survey design were achieved using 56 per cent fewer electrodes. The performance was also tested on a 3-D acquisition grid, where superior resolution within a target at the base of an embankment was achieved using 22 per cent fewer electrodes than a comparable standard survey. The effect of the underlying resistivity distribution on the performance of the optimization was investigated and it was shown that even strong resistivity contrasts only have minor impact. The synthetic results were verified in a laboratory tank experiment, where notable image improvements were achieved. This work shows that optimized surveys can be designed that have a resolution superior to standard survey designs, while requiring significantly fewer electrodes. This methodology thereby provides a means for improving the efficiency of geoelectrical imaging.

  2. Optimized survey design for Electrical Resistivity Tomography: combined optimization of measurement configuration and electrode placement

    NASA Astrophysics Data System (ADS)

    Uhlemann, Sebastian; Wilkinson, Paul B.; Maurer, Hansruedi; Wagner, Florian M.; Johnson, Timothy C.; Chambers, Jonathan E.

    2018-03-01

    Within geoelectrical imaging, the choice of measurement configurations and electrode locations is known to control the image resolution. Previous work has shown that optimized survey designs can provide a model resolution that is superior to standard survey designs. This paper demonstrates a methodology to optimize resolution within a target area, while limiting the number of required electrodes, thereby selecting optimal electrode locations. This is achieved by extending previous work on the `Compare-R' algorithm, which by calculating updates to the resolution matrix optimizes the model resolution in a target area. Here, an additional weighting factor is introduced that allows to preferentially adding measurement configurations that can be acquired on a given set of electrodes. The performance of the optimization is tested on two synthetic examples and verified with a laboratory study. The effect of the weighting factor is investigated using an acquisition layout comprising a single line of electrodes. The results show that an increasing weight decreases the area of improved resolution, but leads to a smaller number of electrode positions. Imaging results superior to a standard survey design were achieved using 56 per cent fewer electrodes. The performance was also tested on a 3D acquisition grid, where superior resolution within a target at the base of an embankment was achieved using 22 per cent fewer electrodes than a comparable standard survey. The effect of the underlying resistivity distribution on the performance of the optimization was investigated and it was shown that even strong resistivity contrasts only have minor impact. The synthetic results were verified in a laboratory tank experiment, where notable image improvements were achieved. This work shows that optimized surveys can be designed that have a resolution superior to standard survey designs, while requiring significantly fewer electrodes. This methodology thereby provides a means for improving the efficiency of geoelectrical imaging.

  3. Comparative clinical outcomes between pediatric and young adult dialysis patients.

    PubMed

    Atkinson, Meredith A; Lestz, Rachel M; Fivush, Barbara A; Silverstein, Douglas M

    2011-12-01

    Published data on the comparative achievement of The Kidney Disease Dialysis Outcome Quality Initiative (KDOQI) recommended clinical performance targets between children and young adults on dialysis are scarce. To characterize the achievement of KDOQI targets among children (<18 years) and young adults (18-24 years) with prevalent end stage renal disease (ESRD), we performed a cross-sectional analysis of data collected by the Mid-Atlantic Renal Coalition, in conjunction with the 2007 and 2008 ESRD Clinical Performance Measures Projects. Data on all enrolled pediatric dialysis patients, categorized into three age groups (0-8, 9-12, 13-17 years), and on a random sample of 5% of patients ≥ 18 years in ESRD Network 5 were examined for two study periods: hemodialysis (HD) data were collected from October to December 2006 and from October to December 2007 and peritoneal dialysis (PD) data were collected from October 2006 to March 2007 and from October 2007 to March 2008. In total, 114 unique patients were enrolled the study, of whom 41.2% (47/114) were on HD and 58.8% (67/114) on PD. Compared to the pediatric patients, young adults were less likely to achieve the KDOQI recommended serum phosphorus levels and serum calcium × phosphorus product values, with less than one-quarter demonstrating values at or below each goal. Multivariate analysis revealed that both young adults and 13- to 17-year-olds were less likely to achieve target values for phosphorus [young adults: odds ratio (OR) 0.04, 95% confidence interval (95% CI) 0.01-0.19, p < 0.001; 13- to 17-year-olds: OR 0.17, 95% CI 0.04-0.77, p = 0.02] and calcium × phosphorus product (young adults: OR 0.01, 95% CI 0.002-0.09, p < 0.001; 13- to 17-year-olds: OR 0.09, 95% CI 0.02-0.56, p = 0.01) than younger children. In summary, there are significant differences in clinical indices between pediatric and young adult ESRD patients.

  4. The Comparison of Turkish Students' PISA Achievement Levels by Year via Data Envelopment Analysis

    ERIC Educational Resources Information Center

    Yalçin, Seher; Tavsancil, Ezel

    2014-01-01

    This research aimed to determine the relative efficiency of the types of school common to three administrations of the PISA (2003-2006-2009) by comparing their results, along with the activities that are to be performed for inefficient school types and changes in the efficiency value of the school types by year. The comparative analysis was based…

  5. The Effects of Two Scheduling Formats on Student Achievement in a Suburban High School Setting

    ERIC Educational Resources Information Center

    Jackson, Kenyada Morton

    2013-01-01

    Limited studies have been conducted on the relationship between scheduling formats and academic performance of high school students. At the target high school, students underperform on standardized tests in English language arts (ELA) and math. The purpose of this causal comparative quantitative study was to compare the means of ELA and math test…

  6. Validation of an automated seizure detection algorithm for term neonates

    PubMed Central

    Mathieson, Sean R.; Stevenson, Nathan J.; Low, Evonne; Marnane, William P.; Rennie, Janet M.; Temko, Andrey; Lightbody, Gordon; Boylan, Geraldine B.

    2016-01-01

    Objective The objective of this study was to validate the performance of a seizure detection algorithm (SDA) developed by our group, on previously unseen, prolonged, unedited EEG recordings from 70 babies from 2 centres. Methods EEGs of 70 babies (35 seizure, 35 non-seizure) were annotated for seizures by experts as the gold standard. The SDA was tested on the EEGs at a range of sensitivity settings. Annotations from the expert and SDA were compared using event and epoch based metrics. The effect of seizure duration on SDA performance was also analysed. Results Between sensitivity settings of 0.5 and 0.3, the algorithm achieved seizure detection rates of 52.6–75.0%, with false detection (FD) rates of 0.04–0.36 FD/h for event based analysis, which was deemed to be acceptable in a clinical environment. Time based comparison of expert and SDA annotations using Cohen’s Kappa Index revealed a best performing SDA threshold of 0.4 (Kappa 0.630). The SDA showed improved detection performance with longer seizures. Conclusion The SDA achieved promising performance and warrants further testing in a live clinical evaluation. Significance The SDA has the potential to improve seizure detection and provide a robust tool for comparing treatment regimens. PMID:26055336

  7. Automated Classification of Radiology Reports for Acute Lung Injury: Comparison of Keyword and Machine Learning Based Natural Language Processing Approaches.

    PubMed

    Solti, Imre; Cooke, Colin R; Xia, Fei; Wurfel, Mark M

    2009-11-01

    This paper compares the performance of keyword and machine learning-based chest x-ray report classification for Acute Lung Injury (ALI). ALI mortality is approximately 30 percent. High mortality is, in part, a consequence of delayed manual chest x-ray classification. An automated system could reduce the time to recognize ALI and lead to reductions in mortality. For our study, 96 and 857 chest x-ray reports in two corpora were labeled by domain experts for ALI. We developed a keyword and a Maximum Entropy-based classification system. Word unigram and character n-grams provided the features for the machine learning system. The Maximum Entropy algorithm with character 6-gram achieved the highest performance (Recall=0.91, Precision=0.90 and F-measure=0.91) on the 857-report corpus. This study has shown that for the classification of ALI chest x-ray reports, the machine learning approach is superior to the keyword based system and achieves comparable results to highest performing physician annotators.

  8. Automated Classification of Radiology Reports for Acute Lung Injury: Comparison of Keyword and Machine Learning Based Natural Language Processing Approaches

    PubMed Central

    Solti, Imre; Cooke, Colin R.; Xia, Fei; Wurfel, Mark M.

    2010-01-01

    This paper compares the performance of keyword and machine learning-based chest x-ray report classification for Acute Lung Injury (ALI). ALI mortality is approximately 30 percent. High mortality is, in part, a consequence of delayed manual chest x-ray classification. An automated system could reduce the time to recognize ALI and lead to reductions in mortality. For our study, 96 and 857 chest x-ray reports in two corpora were labeled by domain experts for ALI. We developed a keyword and a Maximum Entropy-based classification system. Word unigram and character n-grams provided the features for the machine learning system. The Maximum Entropy algorithm with character 6-gram achieved the highest performance (Recall=0.91, Precision=0.90 and F-measure=0.91) on the 857-report corpus. This study has shown that for the classification of ALI chest x-ray reports, the machine learning approach is superior to the keyword based system and achieves comparable results to highest performing physician annotators. PMID:21152268

  9. Obtaining high resolution XUV coronal images

    NASA Technical Reports Server (NTRS)

    Golub, L.; Spiller, E.

    1992-01-01

    Photographs obtained during three flights of an 11 inch diameter normal incident soft X-ray (wavelength 63.5 A) telescope are analyzed and the data are compared to the results expected from tests of the mirror surfaces. Multilayer coated X ray telescopes have the potential for 0.01 arcsec resolution, and there is optimism that such high quality mirrors can be built. Some of the factors which enter into the performance actually achieved in practice are as follows: quality of the mirror substrate, quality of the multilayer coating, and number of photons collected. Measurements of multilayer mirrors show that the actual performance achieved in the solar X-ray images demonstrates a reduction in the scattering compared to that calculated from the topography of the top surface of the multilayer. In the brief duration of a rocket flight, the resolution is also limited by counting statistics from the number of photons collected. At X-ray Ultraviolet (XUV) wavelengths from 171 to 335 A the photon flux should be greater than 10(exp 10) ph/sec, so that a resolution better than 0.1 arcsec might be achieved, if mirror quality does not provide a limit first. In a satellite, a large collecting area will be needed for the highest resolution.

  10. A Comparative Analysis between GaN-Based Current and Voltage Mode Class-D and E PAs for Communications

    DTIC Science & Technology

    2017-03-01

    power level (5-10W) transmitters. The designs are analyzed and compared with respect to non-idealities such as bondwire effects and input signal duty...Hence, sub-optimum class- E/inverse class-E designs were implemented in this work and compared with respect to reduced duty cycle performance...inverse class E PA achieves 61.5% efficiency for medium power levels (37.7dBm) at 880MHz. The three designed PAs have been compared with respect to

  11. Spectrum-enhanced Au@ZnO plasmonic nanoparticles for boosting dye-sensitized solar cell performance

    NASA Astrophysics Data System (ADS)

    Liu, Qisheng; Wei, Yunwei; Shahid, Malik Zeeshan; Yao, Mingming; Xu, Bo; Liu, Guangning; Jiang, Kejian; Li, Cuncheng

    2018-03-01

    Spectrum-enhanced Au@ZnO plasmonic nanoparticles (NPs) are developed for fabrication of the dye-sensitized solar cells (DSSCs), and their remarkable enhanced performances are achieved due to Surface Plasmon Resonance (SPR) effects. When being doped different blended amounts of the Au@ZnO NPs within the photoanode layers, various enhanced effects in the SPR-based DSSCs are exhibited. Compared with the power conversion efficiency (PCE, 7.50%) achieved for bare DSSC, device with doped Au@ZnO NPs of 1.93% delivers the top PCE of 8.91%, exhibiting about 20% enhancement. To elaborate the charge transfer process in the Au@ZnO NPs blended DSSCs, the photoluminescence (PL), electrochemical impedance spectra (EIS), etc are performed. We find that both the enhanced SPR absorption properties and the suppressed recombination process of charges contribute much to the improved performance of Au@ZnO-incorporated DSSCs.

  12. The performance of solar thermal electric power systems employing small heat engines

    NASA Technical Reports Server (NTRS)

    Pons, R. L.

    1980-01-01

    The paper presents a comparative analysis of small (10 to 100 KWe) heat engines for use with a solar thermal electric system employing the point-focusing, distributed receiver (PF-DR) concept. Stirling, Brayton, and Rankine cycle engines are evaluated for a nominal overall system power level of 1 MWe, although the concept is applicable to power levels up to at least 10 MWe. Multiple concentrators are electrically connected to achieve the desired plant output. Best performance is achieved with the Stirling engine, resulting in a system Levelized Busbar Energy Cost of just under 50 mills/kWH and a Capital Cost of $900/kW, based on the use of mass-produced components. Brayton and Rankine engines show somewhat less performance but are viable alternatives with particular benefits for special applications. All three engines show excellent performance for the small community application.

  13. Portable multi-node LQCD Monte Carlo simulations using OpenACC

    NASA Astrophysics Data System (ADS)

    Bonati, Claudio; Calore, Enrico; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Sanfilippo, Francesco; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

    This paper describes a state-of-the-art parallel Lattice QCD Monte Carlo code for staggered fermions, purposely designed to be portable across different computer architectures, including GPUs and commodity CPUs. Portability is achieved using the OpenACC parallel programming model, used to develop a code that can be compiled for several processor architectures. The paper focuses on parallelization on multiple computing nodes using OpenACC to manage parallelism within the node, and OpenMPI to manage parallelism among the nodes. We first discuss the available strategies to be adopted to maximize performances, we then describe selected relevant details of the code, and finally measure the level of performance and scaling-performance that we are able to achieve. The work focuses mainly on GPUs, which offer a significantly high level of performances for this application, but also compares with results measured on other processors.

  14. Outcomes for youth residential treatment programs using administrative data from the child welfare system: a risk-adjustment application.

    PubMed

    McMillen, J Curtis; Lee, Bethany R; Jonson-Reid, Melissa

    2008-05-01

    This study assessed whether administrative data from the public child welfare system could be used to develop risk-adjusted performance reports for residential mental health programs for adolescents. Regression methods were used with 3,759 residential treatment spells for 2,784 children and youth to determine which outcomes could be adequately risk adjusted for case mix. Expected outcomes were created for each residential program given its case mix; then, expected and achieved outcomes were compared. For most programs, achieved results did not differ significantly from expected results for individual outcomes. Overall, outcomes achieved were not impressive. Only one quarter of spells resulted in a youth being maintained in a single less restrictive setting in the year following discharge. Methodological implications of this study suggest further refinements are needed for child welfare administrative data in order to develop risk-adjusted report cards of program performance.

  15. A Simple Index for the High-Citation Tail of Citation Distribution to Quantify Research Performance in Countries and Institutions

    PubMed Central

    Rodríguez-Navarro, Alonso

    2011-01-01

    Background Conventional scientometric predictors of research performance such as the number of papers, citations, and papers in the top 1% of highly cited papers cannot be validated in terms of the number of Nobel Prize achievements across countries and institutions. The purpose of this paper is to find a bibliometric indicator that correlates with the number of Nobel Prize achievements. Methodology/Principal Findings This study assumes that the high-citation tail of citation distribution holds most of the information about high scientific performance. Here I propose the x-index, which is calculated from the number of national articles in the top 1% and 0.1% of highly cited papers and has a subtractive term to discount highly cited papers that are not scientific breakthroughs. The x-index, the number of Nobel Prize achievements, and the number of national articles in Nature or Science are highly correlated. The high correlations among these independent parameters demonstrate that they are good measures of high scientific performance because scientific excellence is their only common characteristic. However, the x-index has superior features as compared to the other two parameters. Nobel Prize achievements are low frequency events and their number is an imprecise indicator, which in addition is zero in most institutions; the evaluation of research making use of the number of publications in prestigious journals is not advised. Conclusion The x-index is a simple and precise indicator for high research performance. PMID:21647383

  16. A simple index for the high-citation tail of citation distribution to quantify research performance in countries and institutions.

    PubMed

    Rodríguez-Navarro, Alonso

    2011-01-01

    Conventional scientometric predictors of research performance such as the number of papers, citations, and papers in the top 1% of highly cited papers cannot be validated in terms of the number of Nobel Prize achievements across countries and institutions. The purpose of this paper is to find a bibliometric indicator that correlates with the number of Nobel Prize achievements. This study assumes that the high-citation tail of citation distribution holds most of the information about high scientific performance. Here I propose the x-index, which is calculated from the number of national articles in the top 1% and 0.1% of highly cited papers and has a subtractive term to discount highly cited papers that are not scientific breakthroughs. The x-index, the number of Nobel Prize achievements, and the number of national articles in Nature or Science are highly correlated. The high correlations among these independent parameters demonstrate that they are good measures of high scientific performance because scientific excellence is their only common characteristic. However, the x-index has superior features as compared to the other two parameters. Nobel Prize achievements are low frequency events and their number is an imprecise indicator, which in addition is zero in most institutions; the evaluation of research making use of the number of publications in prestigious journals is not advised. The x-index is a simple and precise indicator for high research performance.

  17. Acting Irrationally to Improve Performance in Stochastic Worlds

    NASA Astrophysics Data System (ADS)

    Belavkin, Roman V.

    Despite many theories and algorithms for decision-making, after estimating the utility function the choice is usually made by maximising its expected value (the max EU principle). This traditional and 'rational' conclusion of the decision-making process is compared in this paper with several 'irrational' techniques that make choice in Monte-Carlo fashion. The comparison is made by evaluating the performance of simple decision-theoretic agents in stochastic environments. It is shown that not only the random choice strategies can achieve performance comparable to the max EU method, but under certain conditions the Monte-Carlo choice methods perform almost two times better than the max EU. The paper concludes by quoting evidence from recent cognitive modelling works as well as the famous decision-making paradoxes.

  18. Achievement Goal Orientations and Adolescents’ Subjective Well-Being in School: The Mediating Roles of Academic Social Comparison Directions

    PubMed Central

    Tian, Lili; Yu, Tingting; Huebner, E. Scott

    2017-01-01

    The purpose of this study was to examine the multiple mediational roles of academic social comparison directions (upward academic social comparison and downward academic social comparison) on the relationships between achievement goal orientations (i.e., mastery goals, performance-approach goals, and performance-avoidance goals) and subjective well-being (SWB) in school (school satisfaction, school affect) in adolescent students in China. A total of 883 Chinese adolescent students (430 males; Mean age = 12.99) completed a multi-measure questionnaire. Structural equation modeling was used to examine the hypotheses. Results indicated that (1) mastery goal orientations and performance-approach goal orientations both showed a statistically significant, positive correlation with SWB in school whereas performance-avoidance goal orientations showed a statistically significant, negative correlation with SWB in school among adolescents; (2) upward academic social comparisons mediated the relation between the three types of achievement goal orientations (i.e., mastery goals, performance-approach goals, and performance-avoidance goals) and SWB in school; (3) downward academic social comparisons mediated the relation between mastery goal orientations and SWB in school as well as the relation between performance-avoidance goal orientations and SWB in school. The findings suggest possible important cultural differences in the antecedents of SWB in school in adolescent students in China compared to adolescent students in Western nations. PMID:28197109

  19. Dynamics-A explorer RIMS data analysis

    NASA Technical Reports Server (NTRS)

    Banks, P. M.; Clauer, C. R.

    1985-01-01

    Activities of the RIMS instrument during the extended mission are planned. The modes of operation for RIMS to achieve the science requirements utilizing the new and exciting information on the composition and dynamics of the low energy (0-50eV) ions in the Earth's ionosphere and magnetosphere are determined. The specific science problems and the required RIMS operational modes needed to acquire the desired data are identified. The analysis was performed on the RIMS data to achieve the science results and this new information was used in determining RIMS operations during the latter part of the mission. Necessary sensitivity tests of RIMS operating modes and instrument performance was suggested. The inflight results was compared with theoretical models.

  20. Non-destructive determination of Malondialdehyde (MDA) distribution in oilseed rape leaves by laboratory scale NIR hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Kong, Wenwen; Liu, Fei; Zhang, Chu; Zhang, Jianfeng; Feng, Hailin

    2016-10-01

    The feasibility of hyperspectral imaging with 400-1000 nm was investigated to detect malondialdehyde (MDA) content in oilseed rape leaves under herbicide stress. After comparing the performance of different preprocessing methods, linear and nonlinear calibration models, the optimal prediction performance was achieved by extreme learning machine (ELM) model with only 23 wavelengths selected by competitive adaptive reweighted sampling (CARS), and the result was RP = 0.929 and RMSEP = 2.951. Furthermore, MDA distribution map was successfully achieved by partial least squares (PLS) model with CARS. This study indicated that hyperspectral imaging technology provided a fast and nondestructive solution for MDA content detection in plant leaves.

  1. Verbal communication improves laparoscopic team performance.

    PubMed

    Shiliang Chang; Waid, Erin; Martinec, Danny V; Bin Zheng; Swanstrom, Lee L

    2008-06-01

    The impact of verbal communication on laparoscopic team performance was examined. A total of 24 dyad teams, comprised of residents, medical students, and office staff, underwent 2 team tasks using a previously validated bench model. Twelve teams (feedback groups) received instant verbal instruction and feedback on their performance from an instructor which was compared with 12 teams (control groups) with minimal or no verbal feedback. Their performances were both video and audio taped for analysis. Surgical backgrounds were similar between feedback and control groups. Teams with more verbal feedback achieved significantly better task performance (P = .002) compared with the control group with less feedback. Impact of verbal feedback was more pronounced for tasks requiring team cooperation (aiming and navigation) than tasks depending on individual skills (knotting). Verbal communication, especially the instructions and feedback from an experienced instructor, improved team efficiency and performance.

  2. A Comparison of Performance on Cloze Tests, Group Reading Inventories and Standardized Reading Achievement in Grades Seven, Eight and Nine.

    ERIC Educational Resources Information Center

    Rakes, Thomas A.; McWilliams, Lana J.

    A random sample of 300 seventh, eighth, and ninth grade students participated in a comparative study of performance on social studies cloze tests, social studies group reading inventories (GRI), and a popular standardized test (Gates-MacGinitie Reading Tests, Survey E). It was found that cloze tests and GRIs constructed from social studies content…

  3. The Effectiveness of Writing Conferences and Peer Response Groups Strategies on the EFL Secondary Students' Writing Performance and Their Self Efficacy (A Comparative Study)

    ERIC Educational Resources Information Center

    Hussein, Mohamed Abdel Hadi; Al Ashri, Ismail Ibrahim El shirbini Abdel fattah

    2013-01-01

    The present study aimed at identifying the necessary writing performance skills for the first year secondary stage students. These skills are necessary for writing the compositions. In this study, the writing conferences and peer response groups strategies were used to develop the students' writing skills, improve their achievement and performance…

  4. Levels of Music Performance Anxiety and Test Anxiety of Turkish Prospective Music Teachers in Piano Exams

    ERIC Educational Resources Information Center

    Guven, Elif

    2017-01-01

    The purpose of this study was to determine the anxiety of prospective music teachers (N = 129) during piano exams and to examine the effects of peer and self-assessments on anxiety and exam achievement of individuals with high performance and test anxiety (n = 5). Female students were more anxious compared to males, students of the fourth class…

  5. An enhanced high-speed multi-digit BCD adder using quantum-dot cellular automata

    NASA Astrophysics Data System (ADS)

    Ajitha, D.; Ramanaiah, K. V.; Sumalatha, V.

    2017-02-01

    The advent of development of high-performance, low-power digital circuits is achieved by a suitable emerging nanodevice called quantum-dot cellular automata (QCA). Even though many efficient arithmetic circuits were designed using QCA, there is still a challenge to implement high-speed circuits in an optimized manner. Among these circuits, one of the essential structures is a parallel multi-digit decimal adder unit with significant speed which is very attractive for future environments. To achieve high speed, a new correction logic formulation method is proposed for single and multi-digit BCD adder. The proposed enhanced single-digit BCD adder (ESDBA) is 26% faster than the carry flow adder (CFA)-based BCD adder. The multi-digit operations are also performed using the proposed ESDBA, which is cascaded innovatively. The enhanced multi-digit BCD adder (EMDBA) performs two 4-digit and two 8-digit BCD addition 50% faster than the CFA-based BCD adder with the nominal overhead of the area. The EMDBA performs two 4-digit BCD addition 24% faster with 23% decrease in the area, similarly for 8-digit operation the EMDBA achieves 36% increase in speed with 21% less area compared to the existing carry look ahead (CLA)-based BCD adder design. The proposed multi-digit adder produces significantly less delay of (N –1) + 3.5 clock cycles compared to the N* One digit BCD adder delay required by the conventional BCD adder method. It is observed that as per our knowledge this is the first innovative proposal for multi-digit BCD addition using QCA.

  6. STEM after school programming: The effect on student achievement and attitude

    NASA Astrophysics Data System (ADS)

    Ashford, Vanessa Dale

    Science, technology, engineering and math (STEM) curriculum has become a major component in to 21st century teaching and learning. STEM skills and STEM careers are in demand globally. Disadvantaged and minority students continue to have an achievement gap in STEM classes. They do not perform well in elementary and middle school and frequently do not pursue STEM-based studies in high school or careers in the field. One innovation in STEM education is after-school programming to increase student interest, attitudes, and achievement. This mixed-methods study examines the Discovery Place After-School STEM Program to compare the achievement levels of participants to non-participants in the program and provides recommendations for STEM after-school programming across the district. As part of the study, teachers were interviewed to examine attitudes and perceptions about the program. This study was conducted at an elementary school in a large urban school district in the southeastern United States which has a unique STEM-based after-school program. Student performance data indicated a significant difference in achievement between participants and non-participants in the program as measured by fifth grade science End-of-Grade test. Data from the seven units of study in the program showed significant achievement for three of the seven units.

  7. Comparative analysis of the modified enclosed energy metric for self-focusing holograms from digital lensless holographic microscopy.

    PubMed

    Trujillo, Carlos; Garcia-Sucerquia, Jorge

    2015-06-01

    A comparative analysis of the performance of the modified enclosed energy (MEE) method for self-focusing holograms recorded with digital lensless holographic microscopy is presented. Notwithstanding the MEE analysis previously published, no extended analysis of its performance has been reported. We have tested the MEE in terms of the minimum axial distance allowed between the set of reconstructed holograms to search for the focal plane and the elapsed time to obtain the focused image. These parameters have been compared with those for some of the already reported methods in the literature. The MEE achieves better results in terms of self-focusing quality but at a higher computational cost. Despite its longer processing time, the method remains within a time frame to be technologically attractive. Modeled and experimental holograms have been utilized in this work to perform the comparative study.

  8. Microwave ablation at 10.0 GHz achieves comparable ablation zones to 1.9 GHz in ex vivo bovine liver.

    PubMed

    Luyen, Hung; Gao, Fuqiang; Hagness, Susan C; Behdad, Nader

    2014-06-01

    We demonstrate the feasibility of using high-frequency microwaves for tissue ablation by comparing the performance of a 10 GHz microwave ablation system with that of a 1.9 GHz system. Two sets of floating sleeve dipole antennas operating at these frequencies were designed and fabricated for use in ex vivo experiments with bovine livers. Combined electromagnetic and transient thermal simulations were conducted to analyze the performance of these antennas. Subsequently, a total of 16 ablation experiments (eight at 1.9 GHz and eight at 10.0 GHz) were conducted at a power level of 42 W for either 5 or 10 min. In all cases, the 1.9 and 10 GHz experiments resulted in comparable ablation zone dimensions. Temperature monitoring probes revealed faster heating rates in the immediate vicinity of the 10.0 GHz antenna compared to the 1.9 GHz antenna, along with a slightly delayed onset of heating farther from the 10 GHz antenna, suggesting that heat conduction plays a greater role at higher microwave frequencies in achieving a comparably sized ablation zone. The results obtained from these experiments agree very well with the combined electromagnetic/thermal simulation results. These simulations and experiments show that using lower frequency microwaves does not offer any significant advantages, in terms of the achievable ablation zones, over using higher frequency microwaves. Indeed, it is demonstrated that high-frequency microwave antennas may be used to create reasonably large ablation zones. Higher frequencies offer the advantage of smaller antenna size, which is expected to lead to less invasive interstitial devices and may possibly lead to the development of more compact multielement arrays with heating properties not available from single-element antennas.

  9. Electrophysiological dynamic brain connectivity during symbolic magnitude comparison in children with different mathematics achievement levels.

    PubMed

    Gómez-Velázquez, Fabiola R; Vélez-Pérez, Hugo; Espinoza-Valdez, Aurora; Romo-Vazquez, Rebeca; Salido-Ruiz, Ricardo A; Ruiz-Stovel, Vanessa; Gallardo-Moreno, Geisa B; González-Garrido, Andrés A; Berumen, Gustavo

    2017-02-08

    Children with mathematical difficulties usually have an impaired ability to process symbolic representations. Functional MRI methods have suggested that early frontoparietal connectivity can predict mathematic achievements; however, the study of brain connectivity during numerical processing remains unexplored. With the aim of evaluating this in children with different math proficiencies, we selected a sample of 40 children divided into two groups [high achievement (HA) and low achievement (LA)] according to their arithmetic scores in the Wide Range Achievement Test, 4th ed.. Participants performed a symbolic magnitude comparison task (i.e. determining which of two numbers is numerically larger), with simultaneous electrophysiological recording. Partial directed coherence and graph theory methods were used to estimate and depict frontoparietal connectivity in both groups. The behavioral measures showed that children with LA performed significantly slower and less accurately than their peers in the HA group. Significantly higher frontocentral connectivity was found in LA compared with HA; however, when the connectivity analysis was restricted to parietal locations, no relevant group differences were observed. These findings seem to support the notion that LA children require greater memory and attentional efforts to meet task demands, probably affecting early stages of symbolic comparison.

  10. Relative performance of 8.5-GHz and 32-GHz telemetry links on the basis of total data return per pass

    NASA Technical Reports Server (NTRS)

    Koerner, M. A.

    1986-01-01

    The performance of X-band (8.5-GHz) and 32-GHz telemetry links is compared on the basis of the total data return per DSN station pass. Differences in spacecraft transmitter efficiency, transmit circuit loss, and transmitting antenna area efficiency and pointing loss are not considered in these calculations. Thus, the performance differentials calculated in this memo are those produced by a DSN 70-m station antenna gain and clear weather receiving system noise temperature and by weather. These calculations show that, assuming mechanical compensation of the DSN 70-m antenna for 32-GHz operation, a performance advantage for 32 GHz over X-band of 8.2 dB can be achieved for at least one DSN station location. Even if only Canberra and Madrid are used, a performance advantage of 7.7 dB can be obtained for at least one DSN station location. A system using a multiple beam feed (electronic compensation) should achieve similar results.

  11. Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

  12. The Prospect of Responsive Spacecraft Using Aeroassisted, Trans-Atmospheric Maneuvers

    DTIC Science & Technology

    2014-06-19

    skip entry aeroassisted maneuvers. By overflying a geographically diverse set of sample ground targets, comparative analysis indicates a significant... analysis . Depending on the chosen re- circularization altitude, the coupled optimal design can achieve an inclination change of 19.91 deg with 50-85...third phase also introduces the “Maneuver Performance Number” as a dimensionless means of comparative effectiveness analysis for both exo- and trans

  13. Early term and late preterm birth are associated with poorer school performance at age 5 years: a cohort study.

    PubMed

    Quigley, Maria A; Poulsen, Gry; Boyle, Elaine; Wolke, Dieter; Field, David; Alfirevic, Zarko; Kurinczuk, Jennifer J

    2012-05-01

    To compare school performance at age 5 years in children born at full term (39-41 weeks gestation) with those born at early term (37-38 weeks gestation), late preterm (34-36 weeks gestation), moderately preterm (32-33 weeks gestation) and very preterm (<32 weeks gestation). Population-based cohort (UK Millennium Cohort Study). Seven thousand six hundred and fifty children born in 2000-2001 and attending school in England in 2006. School performance was measured using the foundation stage profile (FSP), a statutory assessment by teachers at the end of the child's first school year. The FSP comprises 13 assessment scales (scored from 1 to 9). Children who achieve an average of 6 points per scale and at least 6 in certain scales are classified as 'reaching a good level of overall achievement'. Fifty-one per cent of full term children had not reached a good level of overall achievement; this proportion increased with prematurity (55% in early term, 59% in late preterm, 63% in moderately preterm and 66% in very preterm children). Compared with full term children, an elevated risk remained after adjustment, even in early term (adjusted RR 1.05, 95% 1.00 to 1.11) and late preterm children (adjusted RR 1.12, 95% CI 1.04 to 1.22). Similar effects were noted for 'not working securely' in mathematical development, physical development and creative development. The effects of late preterm and early term birth were small in comparison with other risk factors. Late preterm and early term birth are associated with an increased risk of poorer educational achievement at age 5 years.

  14. Weight-elimination neural networks applied to coronary surgery mortality prediction.

    PubMed

    Ennett, Colleen M; Frize, Monique

    2003-06-01

    The objective was to assess the effectiveness of the weight-elimination cost function in improving classification performance of artificial neural networks (ANNs) and to observe how changing the a priori distribution of the training set affects network performance. Backpropagation feedforward ANNs with and without weight-elimination estimated mortality for coronary artery surgery patients. The ANNs were trained and tested on cases with 32 input variables describing the patient's medical history; the output variable was in-hospital mortality (mortality rates: training 3.7%, test 3.8%). Artificial training sets with mortality rates of 20%, 50%, and 80% were created to observe the impact of training with a higher-than-normal prevalence. When the results were averaged, weight-elimination networks achieved higher sensitivity rates than those without weight-elimination. Networks trained on higher-than-normal prevalence achieved higher sensitivity rates at the cost of lower specificity and correct classification. The weight-elimination cost function can improve the classification performance when the network is trained with a higher-than-normal prevalence. A network trained with a moderately high artificial mortality rate (artificial mortality rate of 20%) can improve the sensitivity of the model without significantly affecting other aspects of the model's performance. The ANN mortality model achieved comparable performance as additive and statistical models for coronary surgery mortality estimation in the literature.

  15. Fitness, fatness, and academic performance in seventh-grade elementary school students

    PubMed Central

    2014-01-01

    Background In addition to the benefits on physical and mental health, cardiorespiratory fitness has shown to have positive effects on cognition. This study aimed to investigate the relationship between cardiorespiratory fitness and body weight status on academic performance among seventh-grade students. Methods Participants included 1531 grade 7 students (787 male, 744 female), ranging in age from 12 to 14 years (Mage = 12.3 ± 0.60), from 3 different cohorts. Academic performance was measured using the marks students had, at the end of their academic year, in mathematics, language (Portuguese), foreign language (English), and sciences. To assess cardiorespiratory fitness the Progressive Aerobic Cardiovascular Endurance Run, from Fitnessgram, was used as the test battery. The relationship between academic achievement and the independent and combined association of cardiorespiratory fitness/weight status was analysed, using multinomial logistic regression. Results Cardiorespiratory fitness and weight status were independently related with academic achievement. Fit students, compared with unfit students had significantly higher odds for having high academic achievement (OR = 2.29, 95% CI: 1.48-3.55, p < 0.001). Likewise, having a normal weight status was also related with high academic achievement (OR = 3.65, 95% CI: 1.82-7.34, p < 0.001). Conclusions Cardiorespiratory fitness and weight status were independently and combined related to academic achievement in seventh-grade students independent of the different cohorts, providing further support that aerobically fit and normal weight students are more likely to have better performance at school regardless of the year that they were born. PMID:25001376

  16. Fitness, fatness, and academic performance in seventh-grade elementary school students.

    PubMed

    Sardinha, Luís B; Marques, Adilson; Martins, Sandra; Palmeira, António; Minderico, Cláudia

    2014-07-07

    In addition to the benefits on physical and mental health, cardiorespiratory fitness has shown to have positive effects on cognition. This study aimed to investigate the relationship between cardiorespiratory fitness and body weight status on academic performance among seventh-grade students. Participants included 1531 grade 7 students (787 male, 744 female), ranging in age from 12 to 14 years (Mage = 12.3 ± 0.60), from 3 different cohorts. Academic performance was measured using the marks students had, at the end of their academic year, in mathematics, language (Portuguese), foreign language (English), and sciences. To assess cardiorespiratory fitness the Progressive Aerobic Cardiovascular Endurance Run, from Fitnessgram, was used as the test battery. The relationship between academic achievement and the independent and combined association of cardiorespiratory fitness/weight status was analysed, using multinomial logistic regression. Cardiorespiratory fitness and weight status were independently related with academic achievement. Fit students, compared with unfit students had significantly higher odds for having high academic achievement (OR = 2.29, 95% CI: 1.48-3.55, p < 0.001). Likewise, having a normal weight status was also related with high academic achievement (OR = 3.65, 95% CI: 1.82-7.34, p < 0.001). Cardiorespiratory fitness and weight status were independently and combined related to academic achievement in seventh-grade students independent of the different cohorts, providing further support that aerobically fit and normal weight students are more likely to have better performance at school regardless of the year that they were born.

  17. Does aggregate school-wide achievement mediate fifth grade outcomes for former early childhood education participants?

    PubMed

    Curenton, Stephanie M; Dong, Nianbo; Shen, Xiangjin

    2015-07-01

    This study used a multilevel mediation model to test the theory that former early childhood education (ECE) attendees' 5th grade achievement is mediated by the aggregate school-wide achievement of their elementary school. Aggregate school-wide achievement was defined as the percentage of 5th graders in a school who were at/above academic proficiency in reading or math. Research questions were: (a) Do ECE program participants have better achievement at 5th grade compared with their matched peers who did not participate in an ECE program?; and (b) Is the association between ECE attendance and 5th grade academic performance mediated by school-wide achievement? Results indicated that children who attended prekindergarten (pre-K) and child care outperformed their matched peers who had not attended ECE programs; conversely, those children who did not attend ECE actually outperformed their Head Start counterparts. Mediation analyses indicated that aggregate school-wide achievement at 5th grade partially mediated the association between former ECE attendance and 5th grade performance; however, these mediated effects were small. Overall, the size of the total effects of ECE and the 5th grade academic outcomes were consistent with prior studies. This research confirms the long-term effects of pre-K and child care until 5th grade. (c) 2015 APA, all rights reserved).

  18. Filter methods to preserve local contrast and to avoid artifacts in gamut mapping

    NASA Astrophysics Data System (ADS)

    Meili, Marcel; Küpper, Dennis; Barańczuk, Zofia; Caluori, Ursina; Simon, Klaus

    2010-01-01

    Contrary to high dynamic range imaging, the preservation of details and the avoidance of artifacts is not explicitly considered in popular color management systems. An effective way to overcome these difficulties is image filtering. In this paper we investigate several image filter concepts for detail preservation as part of a practical gamut mapping strategy. In particular we define four concepts including various image filters and check their performance with a psycho-visual test. Additionally, we compare our performance evaluation to two image quality measures with emphasis on local contrast. Surprisingly, the most simple filter concept performs highly efficient and achieves an image quality which is comparable to the more established but slower methods.

  19. The design of high dynamic range ROIC for IRFPAs

    NASA Astrophysics Data System (ADS)

    Jiang, Dazhao; Liang, Qinghua; Zhang, Qiwen; Chen, Honglei; Ding, Ruijun

    2015-10-01

    The charge packet readout integrated circuit (ROIC) technology for the IRFPAs is introduced, which can realize that every pixel achieves a very high capacity of the electrons storage, and it also improves the performance of the SNR and reduces the saturation possibility of the pixels. The ROIC for the LWIR requires ability that obtaining high capacity for storing electrons. For the conventional ROIC, the maximum charge capacity is determined by the integration capacitance and the operating voltage, it can achieve a high charge capacity through increasing the area of the integration capacitor or raising the operating voltage. And this paper would introduce a digital method of ROIC that can achieve a very high charge capacity. The circuit architecture of this approach includes the following parts, a preamplifier, a comparator, a counter, and memory arrays. And the maximum charge capacity of the pixel is determined by the counter bits. This new method can achieve a high charge capacity more than 1Ge- every pixel and output the digital signal directly, while that of conventional ROIC is less than 50Me- and output the analog signal from the pixel. In this new circuit, the comparator is a important module, as the integration voltage value need compare with threshold voltage through the comparator all the time during the integration period, and we will discuss the influence of the comparator. This work design the circuit with the CSMC 0.35um CMOS technology, and the simulation use the spectre model.

  20. Mucosal Healing Is Associated With Improved Long-term Outcomes of Patients With Ulcerative Colitis: A Systematic Review and Meta-analysis.

    PubMed

    Shah, Shailja C; Colombel, Jean-Frederic; Sands, Bruce E; Narula, Neeraj

    2016-09-01

    The paradigm for treatment for ulcerative colitis (UC) is shifting from resolving symptoms toward objective measures such as mucosal healing (MH). However, it is unclear whether MH is associated with improved long-term outcomes. We performed a systematic review and meta-analysis to identify and analyze studies comparing long-term outcomes of patients with MH with those without MH. We performed a systematic search of 3 large databases to identify prospective studies of patients with active UC that included outcomes of patients found to have MH at the first endoscopic evaluation after initiation of UC therapy (MH1) compared with those without MH1. The primary outcome was clinical remission after at least 52 weeks. Secondary outcomes included proportions of patients who were free of colectomy or corticosteroids and rate of MH after at least 52 weeks. We analyzed 13 studies comprising 2073 patients with active UC. Patients with MH1 had pooled odds ratio of 4.50 for achieving long-term (after at least 52 weeks) clinical remission (95% confidence interval [CI], 2.12-9.52), 4.15 for remaining free of colectomy (95% CI, 2.53-6.81), 8.40 for achieving long-term MH (95% CI, 3.13-22.53), and 9.70 for achieving long-term corticosteroid-free clinical remission (95% CI, 0.94-99.67), compared with patients without MH1. We found no difference in outcomes if patients achieved MH1 while receiving biologic versus non-biologic therapy. In a meta-analysis, we associated MH with long-term clinical remission, avoidance of colectomy, and corticosteroid-free clinical remission. MH is therefore appropriate goal of UC therapy. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

  1. Development and Evaluation of a Sandia Cooler-based Refrigerator Condenser

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, Terry A.; Kariya, Harumichi Arthur; Leick, Michael T.

    This report describes the first design of a refrigerator condenser using the Sandia Cooler, i.e. air - bearing supported rotating heat - sink impeller. The project included ba seline performance testing of a residential refrigerator, analysis and design development of a Sandia Cooler condenser assembly including a spiral channel baseplate, and performance measurement and validation of this condenser system as incorporated into the residential refrigerator. Comparable performance was achieved in a 60% smaller volume package. The improved modeling parameters can now be used to guide more optimized designs and more accurately predict performance.

  2. Copercolating Networks: An Approach for Realizing High-Performance Transparent Conductors using Multicomponent Nanostructured Networks

    NASA Astrophysics Data System (ADS)

    Das, Suprem R.; Sadeque, Sajia; Jeong, Changwook; Chen, Ruiyi; Alam, Muhammad A.; Janes, David B.

    2016-06-01

    Although transparent conductive oxides such as indium tin oxide (ITO) are widely employed as transparent conducting electrodes (TCEs) for applications such as touch screens and displays, new nanostructured TCEs are of interest for future applications, including emerging transparent and flexible electronics. A number of twodimensional networks of nanostructured elements have been reported, including metallic nanowire networks consisting of silver nanowires, metallic carbon nanotubes (m-CNTs), copper nanowires or gold nanowires, and metallic mesh structures. In these single-component systems, it has generally been difficult to achieve sheet resistances that are comparable to ITO at a given broadband optical transparency. A relatively new third category of TCEs consisting of networks of 1D-1D and 1D-2D nanocomposites (such as silver nanowires and CNTs, silver nanowires and polycrystalline graphene, silver nanowires and reduced graphene oxide) have demonstrated TCE performance comparable to, or better than, ITO. In such hybrid networks, copercolation between the two components can lead to relatively low sheet resistances at nanowire densities corresponding to high optical transmittance. This review provides an overview of reported hybrid networks, including a comparison of the performance regimes achievable with those of ITO and single-component nanostructured networks. The performance is compared to that expected from bulk thin films and analyzed in terms of the copercolation model. In addition, performance characteristics relevant for flexible and transparent applications are discussed. The new TCEs are promising, but significant work must be done to ensure earth abundance, stability, and reliability so that they can eventually replace traditional ITO-based transparent conductors.

  3. Physical activity and gender differences: correlates of compliance with recommended levels of five forms of physical activity among students at nine universities in Libya.

    PubMed

    El Ansari, Walid; Khalil, Khalid; Crone, Diane; Stock, Christiane

    2014-06-01

    This cross-sectional survey assessed and compared by gender the levels and correlates of achieving the international guidelines recommendations on five forms of physical activity (PA) (walking, moderate PA, vigorous PA, moderate or vigorous PA- MVPA, and muscle-strengthening PA). We examined the associations between achieving the international guidelines recommendations on five forms of PA and a variety of sociodemographic, health and academic performance variables. Data was collected across nine Libyan universities (2008-2009, representative sample of 1,300 undergraduates). A self-administered questionnaire assessed frequency and duration of PA/week for each form of PA. Cut-offs for recommended guidelines were set according to the American Heart Association. About 43.7% of students achieved the guidelines for muscle strengthening PA, 20.7% for walking, 11.2% for vigorous PA, 28.5% for MVPA, and 4.8% for moderate PA (excluding walking). Binary logistic regression showed that except for walking, males were consistently associated with achieving the guidelines recommendations for all other forms of PA. Students with higher health awareness were more likely to achieve the guidelines for vigorous PA and muscle strengthening PA. Better academic performance was associated with higher levels of muscle strengthening PA. Students at institutions in the East of Libya were less likely to achieve the guidelines for walking, vigorous PA or muscle strengthening PA as compared to students from the North. Students from the West of Libya were also less likely to walk or to engage in moderate PA than their peers from the North. Overall, relatively low proportions of students achieved the recommended guidelines of PA. Female students were particularly at risk for low level of PA. Attention is required to national policies that promote active living, along with addressing the cultural, geographic and other barriers to engagement of young adult males and females in PA.

  4. Symbolic magnitude processing in elementary school children: A group administered paper-and-pencil measure (SYMP Test).

    PubMed

    Brankaer, Carmen; Ghesquière, Pol; De Smedt, Bert

    2017-08-01

    The ability to compare symbolic numerical magnitudes correlates with children's concurrent and future mathematics achievement. We developed and evaluated a quick timed paper-and-pencil measure that can easily be used, for example in large-scale research, in which children have to cross out the numerically larger of two Arabic one- and two-digit numbers (SYMP Test). We investigated performance on this test in 1,588 primary school children (Grades 1-6) and examined in each grade its associations with mathematics achievement. The SYMP Test had satisfactory test-retest reliability. The SYMP Test showed significant and stable correlations with mathematics achievement for both one-digit and two-digit comparison, across all grades. This replicates the previously observed association between symbolic numerical magnitude processing and mathematics achievement, but extends it by showing that the association is observed in all grades in primary education and occurs for single- as well as multi-digit processing. Children with mathematical learning difficulties performed significantly lower on one-digit comparison and two-digit comparison in all grades. This all suggests satisfactory construct and criterion-related validity of the SYMP Test, which can be used in research, when performing large-scale (intervention) studies, and by practitioners, as screening measure to identify children at risk for mathematical difficulties or dyscalculia.

  5. [[The Devil in the Details: Women's Right to Abortion and Health Organization].

    PubMed

    Pioggia, Alessandra

    Often a woman's right to terminate a pregnancy for health reasons is considered as achieved by simply performing the intervention. But today isn't in doubt that the effective protection of health requires that health organizations carrying out performance which also affect other aspects: taking charge of women, information on services, respect for the dignity and autonomy of women, etc ... You could say that these are details, compared to the final performance. But, as we know, often the devil is in the details.

  6. RRCRank: a fusion method using rank strategy for residue-residue contact prediction.

    PubMed

    Jing, Xiaoyang; Dong, Qiwen; Lu, Ruqian

    2017-09-02

    In structural biology area, protein residue-residue contacts play a crucial role in protein structure prediction. Some researchers have found that the predicted residue-residue contacts could effectively constrain the conformational search space, which is significant for de novo protein structure prediction. In the last few decades, related researchers have developed various methods to predict residue-residue contacts, especially, significant performance has been achieved by using fusion methods in recent years. In this work, a novel fusion method based on rank strategy has been proposed to predict contacts. Unlike the traditional regression or classification strategies, the contact prediction task is regarded as a ranking task. First, two kinds of features are extracted from correlated mutations methods and ensemble machine-learning classifiers, and then the proposed method uses the learning-to-rank algorithm to predict contact probability of each residue pair. First, we perform two benchmark tests for the proposed fusion method (RRCRank) on CASP11 dataset and CASP12 dataset respectively. The test results show that the RRCRank method outperforms other well-developed methods, especially for medium and short range contacts. Second, in order to verify the superiority of ranking strategy, we predict contacts by using the traditional regression and classification strategies based on the same features as ranking strategy. Compared with these two traditional strategies, the proposed ranking strategy shows better performance for three contact types, in particular for long range contacts. Third, the proposed RRCRank has been compared with several state-of-the-art methods in CASP11 and CASP12. The results show that the RRCRank could achieve comparable prediction precisions and is better than three methods in most assessment metrics. The learning-to-rank algorithm is introduced to develop a novel rank-based method for the residue-residue contact prediction of proteins, which achieves state-of-the-art performance based on the extensive assessment.

  7. Convergence and Applications of a Gossip-Based Gauss-Newton Algorithm

    NASA Astrophysics Data System (ADS)

    Li, Xiao; Scaglione, Anna

    2013-11-01

    The Gauss-Newton algorithm is a popular and efficient centralized method for solving non-linear least squares problems. In this paper, we propose a multi-agent distributed version of this algorithm, named Gossip-based Gauss-Newton (GGN) algorithm, which can be applied in general problems with non-convex objectives. Furthermore, we analyze and present sufficient conditions for its convergence and show numerically that the GGN algorithm achieves performance comparable to the centralized algorithm, with graceful degradation in case of network failures. More importantly, the GGN algorithm provides significant performance gains compared to other distributed first order methods.

  8. Neither Schools nor Photocopiers Are Flawless.

    ERIC Educational Resources Information Center

    Mecklenburger, James A.

    1988-01-01

    Compares David Kearns' resentment of school performance (in the same "Kappan" issue) to the author's own frustration with Xerox photocopiers. To achieve the restructuring and choice central to Kearns' educational recovery plan, the schools will need to depend increasingly on technology (computer simulations, interactive video, and…

  9. CBESW: sequence alignment on the Playstation 3.

    PubMed

    Wirawan, Adrianto; Kwoh, Chee Keong; Hieu, Nim Tri; Schmidt, Bertil

    2008-09-17

    The exponential growth of available biological data has caused bioinformatics to be rapidly moving towards a data-intensive, computational science. As a result, the computational power needed by bioinformatics applications is growing exponentially as well. The recent emergence of accelerator technologies has made it possible to achieve an excellent improvement in execution time for many bioinformatics applications, compared to current general-purpose platforms. In this paper, we demonstrate how the PlayStation 3, powered by the Cell Broadband Engine, can be used as a computational platform to accelerate the Smith-Waterman algorithm. For large datasets, our implementation on the PlayStation 3 provides a significant improvement in running time compared to other implementations such as SSEARCH, Striped Smith-Waterman and CUDA. Our implementation achieves a peak performance of up to 3,646 MCUPS. The results from our experiments demonstrate that the PlayStation 3 console can be used as an efficient low cost computational platform for high performance sequence alignment applications.

  10. CBESW: Sequence Alignment on the Playstation 3

    PubMed Central

    Wirawan, Adrianto; Kwoh, Chee Keong; Hieu, Nim Tri; Schmidt, Bertil

    2008-01-01

    Background The exponential growth of available biological data has caused bioinformatics to be rapidly moving towards a data-intensive, computational science. As a result, the computational power needed by bioinformatics applications is growing exponentially as well. The recent emergence of accelerator technologies has made it possible to achieve an excellent improvement in execution time for many bioinformatics applications, compared to current general-purpose platforms. In this paper, we demonstrate how the PlayStation® 3, powered by the Cell Broadband Engine, can be used as a computational platform to accelerate the Smith-Waterman algorithm. Results For large datasets, our implementation on the PlayStation® 3 provides a significant improvement in running time compared to other implementations such as SSEARCH, Striped Smith-Waterman and CUDA. Our implementation achieves a peak performance of up to 3,646 MCUPS. Conclusion The results from our experiments demonstrate that the PlayStation® 3 console can be used as an efficient low cost computational platform for high performance sequence alignment applications. PMID:18798993

  11. Comparison of two paradigms for distributed shared memory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Levelt, W.G.; Kaashoek, M.F.; Bal, H.E.

    1990-08-01

    The paper compares two paradigms for Distributed Shared Memory on loosely coupled computing systems: the shared data-object model as used in Orca, a programming language specially designed for loosely coupled computing systems and the Shared Virtual Memory model. For both paradigms the authors have implemented two systems, one using only point-to-point messages, the other using broadcasting as well. They briefly describe these two paradigms and their implementations. Then they compare their performance on four applications: the traveling salesman problem, alpha-beta search, matrix multiplication and the all pairs shortest paths problem. The measurements show that both paradigms can be used efficientlymore » for programming large-grain parallel applications. Significant speedups were obtained on all applications. The unstructured Shared Virtual Memory paradigm achieves the best absolute performance, although this is largely due to the preliminary nature of the Orca compiler used. The structured shared data-object model achieves the highest speedups and is much easier to program and to debug.« less

  12. Capacitance enhancement of polyaniline coated curved-graphene supercapacitors in a redox-active electrolyte

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Rakhi, R. B.; Alshareef, H. N.

    2013-05-01

    We show, for the first time, a redox-active electrolyte in combination with a polyaniline-coated curved graphene active material to achieve significant enhancement in the capacitance (36-92% increase) compared to supercapacitors that lack the redox-active contribution from the electrolyte. The supercapacitors based on the redox-active electrolyte also exhibit excellent rate capability and very long cycling performance (>50 000 cycles).We show, for the first time, a redox-active electrolyte in combination with a polyaniline-coated curved graphene active material to achieve significant enhancement in the capacitance (36-92% increase) compared to supercapacitors that lack the redox-active contribution from the electrolyte. The supercapacitors based on the redox-active electrolyte also exhibit excellent rate capability and very long cycling performance (>50 000 cycles). Electronic supplementary information (ESI) available: Experimental section, supporting figures including SEM, TEM, XPS, BET, CV and CD curves and a summary table of capacitance. See DOI: 10.1039/c3nr00773a

  13. Unsupervised spike sorting based on discriminative subspace learning.

    PubMed

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2014-01-01

    Spike sorting is a fundamental preprocessing step for many neuroscience studies which rely on the analysis of spike trains. In this paper, we present two unsupervised spike sorting algorithms based on discriminative subspace learning. The first algorithm simultaneously learns the discriminative feature subspace and performs clustering. It uses histogram of features in the most discriminative projection to detect the number of neurons. The second algorithm performs hierarchical divisive clustering that learns a discriminative 1-dimensional subspace for clustering in each level of the hierarchy until achieving almost unimodal distribution in the subspace. The algorithms are tested on synthetic and in-vivo data, and are compared against two widely used spike sorting methods. The comparative results demonstrate that our spike sorting methods can achieve substantially higher accuracy in lower dimensional feature space, and they are highly robust to noise. Moreover, they provide significantly better cluster separability in the learned subspace than in the subspace obtained by principal component analysis or wavelet transform.

  14. A Low-Storage-Consumption XML Labeling Method for Efficient Structural Information Extraction

    NASA Astrophysics Data System (ADS)

    Liang, Wenxin; Takahashi, Akihiro; Yokota, Haruo

    Recently, labeling methods to extract and reconstruct the structural information of XML data, which are important for many applications such as XPath query and keyword search, are becoming more attractive. To achieve efficient structural information extraction, in this paper we propose C-DO-VLEI code, a novel update-friendly bit-vector encoding scheme, based on register-length bit operations combining with the properties of Dewey Order numbers, which cannot be implemented in other relevant existing schemes such as ORDPATH. Meanwhile, the proposed method also achieves lower storage consumption because it does not require either prefix schema or any reserved codes for node insertion. We performed experiments to evaluate and compare the performance and storage consumption of the proposed method with those of the ORDPATH method. Experimental results show that the execution times for extracting depth information and parent node labels using the C-DO-VLEI code are about 25% and 15% less, respectively, and the average label size using the C-DO-VLEI code is about 24% smaller, comparing with ORDPATH.

  15. Simultaneous nitrification-denitrification achieved by an innovative internal-loop airlift MBR: comparative study.

    PubMed

    Li, Y Z; He, Y L; Ohandja, D G; Ji, J; Li, J F; Zhou, T

    2008-09-01

    This study assessed the performance of different single-stage continuous aerated submerged membrane bioreactors (MBR) for nitrogen removal. Almost complete nitrification was achieved in each MBR irrespective of operating mode and biomass system. Denitrification was found to be the rate-limiting step for total nitrogen (T-N) removal. The MBR with internal-loop airlift reactor (ALR) configuration performed better as regards T-N removal compared with continuous stirred-tank reactor (CSTR). It was demonstrated that simultaneous nitrification and denitrification (SND) is the mechanism leading to nitrogen removal and the contribution of microenvironment on SND is more remarkable for the MBRs with hybrid biomass. Macroenvironment analyses showed that gradient distribution of dissolved oxygen (DO) level in airlift MBRs imposed a significant effect on SND. Higher mixed liquor suspended solid (MLSS) concentration led to the improvement in T-N removal by enhancing anoxic microenvironment. Apparent nitrite accumulation coupled with higher nitrogen reduction was accomplished at MLSS concentration exceeded 12.6 g/L.

  16. In vitro and in vivo testing of a novel recessed-step catheter for reflux-free convection-enhanced drug delivery to the brain.

    PubMed

    Gill, T; Barua, N U; Woolley, M; Bienemann, A S; Johnson, D E; S O'Sullivan; Murray, G; Fennelly, C; Lewis, O; Irving, C; Wyatt, M J; Moore, P; Gill, S S

    2013-09-30

    The optimisation of convection-enhanced drug delivery (CED) to the brain is fundamentally reliant on minimising drug reflux. The aim of this study was to evaluate the performance of a novel reflux-resistant CED catheter incorporating a recessed-step and to compare its performance to previously described stepped catheters. The in vitro performance of the recessed-step catheter was compared to a conventional "one-step" catheter with a single transition in outer diameter (OD) at the catheter tip, and a "two-step" design comprising two distal transitions in OD. The volumes of distribution and reflux were compared by performing infusions of Trypan blue into agarose gels. The in vivo performance of the recessed-step catheter was then analysed in a large animal model by performing infusions of 0.2% Gadolinium-DTPA in Large White/Landrace pigs. The recessed-step catheter demonstrated significantly higher volumes of distribution than the one-step and two-step catheters (p=0.0001, one-way ANOVA). No reflux was detected until more than 100 ul had been delivered via the recessed-step catheter, whilst reflux was detected after infusion of only 25 ul via the 2 non-recessed catheters. The recessed-step design also showed superior reflux resistance to a conventational one-step catheter in vivo. Reflux-free infusions were achieved in the thalamus, putamen and white matter at a maximum infusion rate of 5 ul/min using the recessed-step design. The novel recessed-step catheter described in this study shows significant potential for the achievement of predictable high volume, high flow rate infusions whilst minimising the risk of reflux. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Comparing deep neural network and other machine learning algorithms for stroke prediction in a large-scale population-based electronic medical claims database.

    PubMed

    Chen-Ying Hung; Wei-Chen Chen; Po-Tsun Lai; Ching-Heng Lin; Chi-Chun Lee

    2017-07-01

    Electronic medical claims (EMCs) can be used to accurately predict the occurrence of a variety of diseases, which can contribute to precise medical interventions. While there is a growing interest in the application of machine learning (ML) techniques to address clinical problems, the use of deep-learning in healthcare have just gained attention recently. Deep learning, such as deep neural network (DNN), has achieved impressive results in the areas of speech recognition, computer vision, and natural language processing in recent years. However, deep learning is often difficult to comprehend due to the complexities in its framework. Furthermore, this method has not yet been demonstrated to achieve a better performance comparing to other conventional ML algorithms in disease prediction tasks using EMCs. In this study, we utilize a large population-based EMC database of around 800,000 patients to compare DNN with three other ML approaches for predicting 5-year stroke occurrence. The result shows that DNN and gradient boosting decision tree (GBDT) can result in similarly high prediction accuracies that are better compared to logistic regression (LR) and support vector machine (SVM) approaches. Meanwhile, DNN achieves optimal results by using lesser amounts of patient data when comparing to GBDT method.

  18. The effect of teacher quality on the achievement of students in Integrated Physics and Chemistry

    NASA Astrophysics Data System (ADS)

    Alexander, Rima

    For many years, researchers, policy makers, and the education community have explored various school variables and their impact on student achievement (Darling-Hammond, 2000; Ferguson and Womack 1993; Ferguson and Ladd 1996; Rice, 2003; Rockoff, 2003; Rowan, Chiang, and Miller 1997; Sanders and Horn, 1996; Wright Horn and Sanders, 1997). Invariably, the issue of teacher quality arises. Teacher quality is the single most influential factor under school control that affects student achievement (Darling-Hammond, 2000; Rice, 2003; Rockoff, 2003; Sanders and Horn, 1996; Wright Horn and Sanders, 1997). Generally, students taught by highly qualified teachers perform better on standardized tests than students with less qualified teachers (Ferguson and Womack 1993; Ferguson and Ladd 1996; Rowan, Chiang, and Miller 1997). Previous research indicates that teachers indeed matter for the improvement of student achievement, but getting good measures of what is meant by teacher quality is a continuing challenge (Goldhaber, 2002). The purpose of this study was to describe the effect of teacher quality on the achievement of students in Integrated Physics and Chemistry (IPC). In order to achieve this purpose, this study addressed the following research question: chemistry and physics teachers compare to the achievement of students taught by less-qualified IPC teachers? A causal-comparative methodology was employed to address this research question. The independent variable was teacher quality---highly-qualified or less qualified. The teacher attributes that were examined in this study are: (1) teachers' educational background; (2) content knowledge; (3) pedagogical knowledge; and (4) certification. The dependent variable was student achievement in integrated physics and chemistry, as measured by an end-of-course IPC District Assessment of Curriculum, IPC DAC. Descriptive statistics were computed for the independent variable in the study. A Chi Square was performed on the data, utilizing SPSS version 12.0.1 software. Next a test of statistical significance was done to determine whether the null hypothesis could be rejected; and whether or not the research hypothesis could be accepted. Since this is a causal comparative design with only two groups in which student achievement was measured by a test that will yield raw scores, a Chi Square was conducted to determine whether the pass rates of the two groups of students based on obtained and expected percentages were statistically significantly different A Chi Square value of 4.29 was obtained, which indicates that the pass rate for students of highly-qualified teachers was statistically significantly higher than for students of less-qualified teachers. For the purpose of this study a criterion value of (p<.05) was used.

  19. Editorial: Cognitive Architectures, Model Comparison and AGI

    NASA Astrophysics Data System (ADS)

    Lebiere, Christian; Gonzalez, Cleotilde; Warwick, Walter

    2010-12-01

    Cognitive Science and Artificial Intelligence share compatible goals of understanding and possibly generating broadly intelligent behavior. In order to determine if progress is made, it is essential to be able to evaluate the behavior of complex computational models, especially those built on general cognitive architectures, and compare it to benchmarks of intelligent behavior such as human performance. Significant methodological challenges arise, however, when trying to extend approaches used to compare model and human performance from tightly controlled laboratory tasks to complex tasks involving more open-ended behavior. This paper describes a model comparison challenge built around a dynamic control task, the Dynamic Stocks and Flows. We present and discuss distinct approaches to evaluating performance and comparing models. Lessons drawn from this challenge are discussed in light of the challenge of using cognitive architectures to achieve Artificial General Intelligence.

  20. Improved parent-reported mobility and achievement of individual goals on activity and participation level after functional power-training in young children with cerebral palsy: a double-baseline controlled trial.

    PubMed

    van Vulpen, Liesbeth F; de Groot, Sonja; Rameckers, Eugene A; Becher, Jules G; Dallmeijer, Annet J

    2018-03-07

    In children with cerebral palsy (CP), strength training programs to improve walking capacity and participation in activities of daily living are commonly used in clinical practice, despite lacking evidence of its effectiveness. It has been suggested that strength training with high movement velocity could be more effective than traditional resistance training to improve functional abilities such as walking. In a recently published study, we have demonstrated the positive effects of functional high-velocity resistance (power) training on muscle strength and walking capacity in young children with CP. Whether this type of training is also effective in achieving individual predefined goals in daily activities and self-reported mobility limitations, has not yet been described however. To evaluate the effect of functional power-training on parent-reported mobility and achievement of individual goals on activity and participation level in young children with CP. A double-baseline design was used to compare a 14-week period usual care with a 14-week period of functional power-training (3 times a week) and a follow-up period of 14-weeks. Twenty-two children with spastic CP (13 bilateral, GMFCS level I (N=10) and level II (N=12), mean age 7.5 years (SD 1.8, range 4-10 y)) and their parents participated. Outcome measures were goal attainment scaling (GAS) of individual daily activity related treatment goals, mobility performance as measured using the Functional Mobility Scale (FMS-5m, 50m and 500m), and the parent-reported Mobility Questionnaire (MobQues). After power-training, 86% of children achieved or exceeded their goal, compared with 14% in the usual care period (p<.001). The probability of improvement by one point or more on the FMS- 500 meter after functional power-training was 10 times higher, compared with the usual care period (Relative Risk=10.0 with 95%CI 1.4 - 71.3). No changes were found in the FMS-5m and FMS-50m categories. Improvement on the MobQues was significantly greater after power-training compared with usual care (7.9% (95% CI 2.7 - 13.0, p=.005)). The improvement in performance in the activities defined in the treatment goals continued during the follow-up period. The results indicated that functional power- training is an effective training to achieve personalized treatment goals for activities in daily life and parent-reported mobility performance in young children with cerebral palsy.

  1. Therapeutic interventions and success in risk factor control for secondary prevention of stroke.

    PubMed

    Alvarez-Sabin, Jose; Quintana, Manuel; Hernandez-Presa, Miguel Angel; Alvarez, Carlos; Chaves, Jose; Ribo, Marc

    2009-01-01

    We sought to evaluate the success rates in achieving preventive therapeutic goals in patients who experienced an ischemic stroke (IS) and compare them with those achieved in patients with coronary artery disease (CAD). This was an observational multicenter case-control study (3 patients with IS and one control subject with CAD) performed in 1444 primary health centers in Spain. Preventive therapeutic objectives according to American Heart Association guidelines were predefined. Demographic data, vascular risk factors, and success/failure in achievement of objectives were recorded and compared between patients with IS and CAD. A total of 5458 patients were included, 4098 (75.1%) had IS and 1360 (24.9%) had CAD. Although more than 90% of patients with hypertension, diabetes, or dyslipidemia were under specific drug regimens, only about 25% achieved the recommended therapeutic objective for each risk factor. Success rate was especially low among patients with IS compared with CAD: hypertension (23.8% v 27.2%; P = .028); dyslipidemia (13.6% v 20.3%; P < .001); and abdominal obesity (49.1% v 54.6%; P = .002). The only objective widely achieved in both groups was the use of antithrombotic drugs in atrial fibrillation (97.2% v 94.7%; P = .125). Only 3.3% of patients with IS had all risk factors under control, compared with 5.6% of those with CAD (P = .006). For all patients, multivariate logistic regression model showed that independent predictors of full risk factor control were: presence of CAD as compared with IS (odds ratio [OR] 2.11; 95% confidence interval [CI] 1.35-3.29; P = .001), older age (OR 1.02; 95% CI 1.00-1.04; P = .028), and having less than 3 risk factors (OR 16.98; 95% CI 9.02-31.97; P < .001). Success in achieving preventive therapeutic objectives for secondary prevention of vascular events is low, especially among patients with IS. There is an urgent need to devise strategies to improve risk factor control.

  2. Process oriented guided inquiry learning (POGIL®) marginally effects student achievement measures but substantially increases the odds of passing a course.

    PubMed

    Walker, Lindsey; Warfa, Abdi-Rizak M

    2017-01-01

    While the inquiry approach to science teaching has been widely recommended as an epistemic mechanism to promote deep content understanding, there is also increased expectation that process and other transferable skills should be integral part of science pedagogy. To test the hypothesis that coupling process skills to content teaching impacts academic success measures, we meta-analyzed twenty-one studies (n = 21) involving 7876 students that compared Process Oriented Guided Inquiry Learning (POGIL), a pedagogy that provides opportunities for improving process skills during content learning through guided-inquiry activities, to standard lecture conditions. Based on conventional measures of class performance, POGIL had a small effect on achievement outcomes (effect size = 0.29, [95% CI = 0.15-0.43]) but substantially improved the odds of passing a class (odds ratio = 2.02, [95% CI: 1.45-2.83]). That is, participants in the POGIL pedagogy had higher odds of passing a course and roughly performed 0.3 standard deviations higher on achievement measures than participants in standard lectures. In relative risk terms, POGIL reduced the risk of failing a course by 38%. These findings suggest providing opportunities to improve process skills during class instruction does not inhibit content learning but enhances conventional success measures. We compare these findings with those of recent large meta-analysis that examined the effects of global active learning methods on achievement outcomes and course failure rates in science, technology, engineering, and mathematics (STEM) fields.

  3. Process oriented guided inquiry learning (POGIL®) marginally effects student achievement measures but substantially increases the odds of passing a course

    PubMed Central

    Walker, Lindsey

    2017-01-01

    While the inquiry approach to science teaching has been widely recommended as an epistemic mechanism to promote deep content understanding, there is also increased expectation that process and other transferable skills should be integral part of science pedagogy. To test the hypothesis that coupling process skills to content teaching impacts academic success measures, we meta-analyzed twenty-one studies (n = 21) involving 7876 students that compared Process Oriented Guided Inquiry Learning (POGIL), a pedagogy that provides opportunities for improving process skills during content learning through guided-inquiry activities, to standard lecture conditions. Based on conventional measures of class performance, POGIL had a small effect on achievement outcomes (effect size = 0.29, [95% CI = 0.15–0.43]) but substantially improved the odds of passing a class (odds ratio = 2.02, [95% CI: 1.45–2.83]). That is, participants in the POGIL pedagogy had higher odds of passing a course and roughly performed 0.3 standard deviations higher on achievement measures than participants in standard lectures. In relative risk terms, POGIL reduced the risk of failing a course by 38%. These findings suggest providing opportunities to improve process skills during class instruction does not inhibit content learning but enhances conventional success measures. We compare these findings with those of recent large meta-analysis that examined the effects of global active learning methods on achievement outcomes and course failure rates in science, technology, engineering, and mathematics (STEM) fields. PMID:29023502

  4. Real-Life Impact of Executive Function Impairments in Adults Who Were Born Very Preterm.

    PubMed

    Kroll, Jasmin; Karolis, Vyacheslav; Brittain, Philip J; Tseng, Chieh-En Jane; Froudist-Walsh, Sean; Murray, Robin M; Nosarti, Chiara

    2017-05-01

    Children and adolescents who were born very preterm (≤32 weeks' gestation) are vulnerable to experiencing cognitive problems, including in executive function. However, it remains to be established whether cognitive deficits are evident in adulthood and whether these exert a significant effect on an individual's real-lifeachievement. Using a cross-sectional design, we tested a range of neurocognitive abilities, with a focus on executive function, in a sample of 122 very preterm individuals and 89 term-born controls born between 1979 and 1984. Associations between executive function and a range of achievement measures, indicative of a successful transition to adulthood, were examined. Very preterm adults performed worse compared to controls on measures of intellectual ability and executive function with moderate to large effect sizes. They also demonstrated significantly lower achievement levels in terms of years spent in education, employment status, and on a measure of functioning in work and social domains. Results of regression analysis indicated a stronger positive association between executive function and real-life achievement in the very preterm group compared to controls. Very preterm born adults demonstrate executive function impairments compared to full-term controls, and these are associated with lower achievement in several real-life domains. (JINS, 2017, 23, 381-389).

  5. Characterisation of a fibre optic Raman probe within a hypodermic needle.

    PubMed

    Iping Petterson, Ingeborg E; Day, John C C; Fullwood, Leanne M; Gardner, Benjamin; Stone, Nick

    2015-11-01

    We demonstrate the first use of a multifibre Raman probe that fits inside the bore of a hypodermic needle. A Raman probe containing multiple collection fibres provides improved signal collection efficiency in biological samples compared with a previous two-fibre design. Furthermore, probe performance (signal-to-noise ratios) compared favourably with the performance achieved in previous Raman microscope experiments able to distinguish between benign lymph nodes, primary malignancies in lymph nodes and secondary malignancies in lymph nodes. The experimental measurements presented here give an indication of the sampling volume of the Raman needle probe in lymphoid tissues. Liquid tissue phantoms were used that contained scattering medium encompassing a range of scattering properties similar to those of a variety of tissue types, including lymph node tissues. To validate the appropriateness of the phantoms, the sampling depth of the probe was also measured in excised lymph node tissue. More than 50 % of Raman photons collected were found to originate from between the tip of the needle and a depth of 500 μm into the tissue. The needle probe presented here achieves spectral quality comparable to that in numerous studies previously demonstrating Raman disease discrimination. It is expected that this approach could achieve targeted subcutaneous tissue measurements and be viable for use for the in vivo Raman diagnostics of solid organs located within a few centimetres below the skin's surface. Graphical Abstract Schematic of multi-fibre Raman needle probe with disposible tips and proximal optical filtration.

  6. Preliminary Experimental Investigation of Quasi Achromat scheme at Advanced Photon Source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sun, Yipeng; Shang, Hairong

    Next generation storage rings require weaker dipolemagnets and stronger quadrupole focusing to achieve very low emittance. To suppress the geometric and chromatic optics aberrations introduced by the strong sextupoles, achromat and quasi achromat schemes are applied in the lattice design to improve the beam dynamics performance. In this paper, some preliminary experimental investigation of the quasi achromat scheme at the Advanced Photon Source (APS) are presented. Three different operation lattices are compared on their beam dynamics performance. Although none of these operation lattices achieve ideal quasi achromat condition, they have certain relevant features. It is observed that fewer resonances aremore » present in the nominal operation lattice which is most close to quasi achromat required conditions.« less

  7. Non-destructive determination of Malondialdehyde (MDA) distribution in oilseed rape leaves by laboratory scale NIR hyperspectral imaging

    PubMed Central

    Kong, Wenwen; Liu, Fei; Zhang, Chu; Zhang, Jianfeng; Feng, Hailin

    2016-01-01

    The feasibility of hyperspectral imaging with 400–1000 nm was investigated to detect malondialdehyde (MDA) content in oilseed rape leaves under herbicide stress. After comparing the performance of different preprocessing methods, linear and nonlinear calibration models, the optimal prediction performance was achieved by extreme learning machine (ELM) model with only 23 wavelengths selected by competitive adaptive reweighted sampling (CARS), and the result was RP = 0.929 and RMSEP = 2.951. Furthermore, MDA distribution map was successfully achieved by partial least squares (PLS) model with CARS. This study indicated that hyperspectral imaging technology provided a fast and nondestructive solution for MDA content detection in plant leaves. PMID:27739491

  8. A National Study of the Relationship between Home Access to a Computer and Academic Performance Scores of Grade 12 U.S. Science Students: An Analysis of the 2009 NAEP Data

    NASA Astrophysics Data System (ADS)

    Coffman, Mitchell Ward

    The purpose of this dissertation was to examine the relationship between student access to a computer at home and academic achievement. The 2009 National Assessment of Educational Progress (NAEP) dataset was probed using the National Data Explorer (NDE) to investigate correlations in the subsets of SES, Parental Education, Race, and Gender as it relates to access of a home computer and improved performance scores for U.S. public school grade 12 science students. A causal-comparative approach was employed seeking clarity on the relationship between home access and performance scores. The influence of home access cannot overcome the challenges students of lower SES face. The achievement gap, or a second digital divide, for underprivileged classes of students, including minorities does not appear to contract via student access to a home computer. Nonetheless, in tests for significance, statistically significant improvement in science performance scores was reported for those having access to a computer at home compared to those not having access. Additionally, regression models reported evidence of correlations between and among subsets of controls for the demographic factors gender, race, and socioeconomic status. Variability in these correlations was high; suggesting influence from unobserved factors may have more impact upon the dependent variable. Having access to a computer at home increases performance scores for grade 12 general science students of all races, genders and socioeconomic levels. However, the performance gap is roughly equivalent to the existing performance gap of the national average for science scores, suggesting little influence from access to a computer on academic achievement. The variability of scores reported in the regression analysis models reflects a moderate to low effect, suggesting an absence of causation. These statistical results are accurate and confirm the literature review, whereby having access to a computer at home and the predictor variables were found to have a significant impact on performance scores, although the data presented suggest computer access at home is less influential upon performance scores than poverty and its correlates.

  9. A Comparison of College Freshman Achievement in Remedial English Courses and in Freshman Composition Courses at a Two-Year College.

    ERIC Educational Resources Information Center

    Baker, Roger G.

    A study was conducted at Snow College to compare the efficiency and effectiveness of college remedial courses with that of regular courses of study. The study compared the performance of 48 students in four sections of a remedial English class with that of 24 students with similar skill levels enrolled in a freshman composition course. The…

  10. College Students' Physical Activity and Health-Related Quality of Life: An Achievement Goal Perspective.

    PubMed

    Zhang, Tao; Xiang, Ping; Gu, Xiangli; Rose, Melanie

    2016-06-01

    The 2 × 2 achievement goal model, including the mastery-approach, mastery-avoidance, performance-approach, and performance-avoidance goal orientations, has recently been used to explain motivational outcomes in physical activity. This study attempted to examine the relationships among 2 × 2 achievement goal orientations, physical activity, and health-related quality of life (HRQOL) in college students. Participants were 325 students (130 men and 195 women; Mage = 21.4 years) enrolled in physical activity classes at a Southern university. They completed surveys validated in previous research assessing achievement goal orientations, physical activity, and HRQOL. Path analyses revealed a good fit between the model and data (root mean square error of approximation = .06; Comparative Fit Index = .99; Bentler-Bonett Nonnormed Fit Index = .98; Incremental Fit Index = .99), but the model explained small variances in the current study. Mastery-approach and performance-approach goal orientations only had low or no relationships with physical activity. Mastery-approach goal orientation and physical activity also had low positive relationships with HRQOL, but mastery-avoidance and performance-avoidance goal orientations had low negative relationships with HRQOL. The hypothesized mediational role of physical activity in the relationship between mastery-approach and performance-approach goal orientations and HRQOL was not supported in this study. Although the data fit the proposed model well, only small variance was explained by the model. The relationship between physical activity and HRQOL of the college students and other related correlates should be further studied.

  11. Coal-fired high performance power generating system. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can bemore » achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved in conventional coal-fired plants. This cycle is based on a gas turbine operating at turbine inlet temperatures approaching 2,500 F. Using an aeroderivative type gas turbine, efficiencies of over 49% could be realized in advanced cycle configuration (Humid Air Turbine, or HAT). Performance of these power plants is given in a table.« less

  12. Performance of (in)active anodic materials for the electrooxidation of phenolic wastewaters from cashew-nut processing industry.

    PubMed

    Oliveira, Edna M S; Silva, Francisco R; Morais, Crislânia C O; Oliveira, Thiago Mielle B F; Martínez-Huitle, Carlos A; Motheo, Artur J; Albuquerque, Cynthia C; Castro, Suely S L

    2018-06-01

    This study investigated the anodic oxidation of phenolic wastewater generated by cashew-nut processing industry (CNPI) using active (Ti/RuO 2 -TiO 2 ) and inactive (boron doped diamond, BDD) anodes. During electrochemical treatment, various operating parameters were investigated, such as current density, chemical oxygen demand (COD), total phenols, O 2 production, temperature, pH, as well as current efficiency and energy consumption. After electrolysis under optimized working conditions, samples were evaluated by chromatography and toxicological tests against L. sativa. When both electrode materials were compared under the same operating conditions, higher COD removal efficiency was achieved for BDD anode; achieving lower energy requirements when compared with the values estimated for Ti/RuO 2 -TiO 2 . The presence of Cl - in the wastewater promoted the electrogeneration of strong oxidant species as chlorine, hypochlorite and mainly hypochlorous acid, increasing the efficiency of degradation process. Regarding the temperature effect, BDD showed slower performances than those achieved for Ti/RuO 2 -TiO 2 . Chromatographic and phytotoxicity studies indicated formation of some by-products after electrolytic process, regardless of the anode evaluated, and phytotoxic action of the effluent. Results encourage the applicability of the electrochemical method as wastewater treatment process for the CNPI, reducing depuration time. Copyright © 2018. Published by Elsevier Ltd.

  13. Simple luminescence detectors using a light-emitting diode or a Xe lamp, optical fiber and charge-coupled device, or photomultiplier for determining proteins in capillary electrophoresis: a critical comparison.

    PubMed

    Casado-Terrones, Silvia; Fernández-Sánchez, Jorge F; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

    2007-06-01

    The performance of two homemade fluorescence-induced capillary electrophoresis detectors, one based on light-emitting diode (LED) as the excitation source and a charge-coupled device (CCD) photodetector and the other based on a commercial luminescence spectrometer (Xe lamp) as the excitation source and a photomultiplier tube as a detector, were compared for the determination of fluorescent proteins R-phycoerythrin and B-phycoerythrin. Both devices use commercially available, reasonably priced optical components that can be used by nonexperts. After fine optimization of several optical and separation parameters in both devices, a zone capillary electrophoresis methodology was achieved with 50mM borate buffer (pH 8.4) and 10mM phytic acid for the determination of two phycobiliproteins. Detection limits of 0.50 and 0.64microg/ml for R-phycoerythrin and B-phycoerythrin, respectively, were achieved by using the LED-induced fluorescence capillary electrophoresis (LED-IF-CE) system, and corresponding detection limits of 2.73 and 2.16microg/ml were achieved by using the Xe lamp-IF-CE system. Analytical performance and other parameters, such as cost and potential to miniaturization, are compared for both devices.

  14. Towards online iris and periocular recognition under relaxed imaging constraints.

    PubMed

    Tan, Chun-Wei; Kumar, Ajay

    2013-10-01

    Online iris recognition using distantly acquired images in a less imaging constrained environment requires the development of a efficient iris segmentation approach and recognition strategy that can exploit multiple features available for the potential identification. This paper presents an effective solution toward addressing such a problem. The developed iris segmentation approach exploits a random walker algorithm to efficiently estimate coarsely segmented iris images. These coarsely segmented iris images are postprocessed using a sequence of operations that can effectively improve the segmentation accuracy. The robustness of the proposed iris segmentation approach is ascertained by providing comparison with other state-of-the-art algorithms using publicly available UBIRIS.v2, FRGC, and CASIA.v4-distance databases. Our experimental results achieve improvement of 9.5%, 4.3%, and 25.7% in the average segmentation accuracy, respectively, for the UBIRIS.v2, FRGC, and CASIA.v4-distance databases, as compared with most competing approaches. We also exploit the simultaneously extracted periocular features to achieve significant performance improvement. The joint segmentation and combination strategy suggest promising results and achieve average improvement of 132.3%, 7.45%, and 17.5% in the recognition performance, respectively, from the UBIRIS.v2, FRGC, and CASIA.v4-distance databases, as compared with the related competing approaches.

  15. Measuring Instructional Merit.

    ERIC Educational Resources Information Center

    Robison, Sharon S.; And Others

    1993-01-01

    Before implementing an instructional program in the Rowland (California) school district, planners must define success in terms of measurable student performance, calculates resources expended in relation to the expected benefits, and determine how long it will take the program to achieve the desired results. Baseline data are then compared to new…

  16. What is the effect of secondary (high) schooling on subsequent medical school performance? A national, UK-based, cohort study

    PubMed Central

    Tiffin, Paul A; Paton, Lewis W; Kasim, Adetayo S; Böhnke, Jan R

    2018-01-01

    Objectives University academic achievement may be inversely related to the performance of the secondary (high) school an entrant attended. Indeed, some medical schools already offer ‘grade discounts’ to applicants from less well-performing schools. However, evidence to guide such policies is lacking. In this study, we analyse a national dataset in order to understand the relationship between the two main predictors of medical school admission in the UK (prior educational attainment (PEA) and performance on the United Kingdom Clinical Aptitude Test (UKCAT)) and subsequent undergraduate knowledge and skills-related outcomes analysed separately. Methods The study was based on national selection data and linked medical school outcomes for knowledge and skills-based tests during the first five years of medical school. UKCAT scores and PEA grades were available for 2107 students enrolled at 18 medical schools. Models were developed to investigate the potential mediating role played by a student’s previous secondary school’s performance. Multilevel models were created to explore the influence of students’ secondary schools on undergraduate achievement in medical school. Results The ability of the UKCAT scores to predict undergraduate academic performance was significantly mediated by PEA in all five years of medical school. Undergraduate achievement was inversely related to secondary school-level performance. This effect waned over time and was less marked for skills, compared with undergraduate knowledge-based outcomes. Thus, the predictive value of secondary school grades was generally dependent on the secondary school in which they were obtained. Conclusions The UKCAT scores added some value, above and beyond secondary school achievement, in predicting undergraduate performance, especially in the later years of study. Importantly, the findings suggest that the academic entry criteria should be relaxed for candidates applying from the least well performing secondary schools. In the UK, this would translate into a decrease of approximately one to two A-level grades. PMID:29792300

  17. Supervised machine learning algorithms to diagnose stress for vehicle drivers based on physiological sensor signals.

    PubMed

    Barua, Shaibal; Begum, Shahina; Ahmed, Mobyen Uddin

    2015-01-01

    Machine learning algorithms play an important role in computer science research. Recent advancement in sensor data collection in clinical sciences lead to a complex, heterogeneous data processing, and analysis for patient diagnosis and prognosis. Diagnosis and treatment of patients based on manual analysis of these sensor data are difficult and time consuming. Therefore, development of Knowledge-based systems to support clinicians in decision-making is important. However, it is necessary to perform experimental work to compare performances of different machine learning methods to help to select appropriate method for a specific characteristic of data sets. This paper compares classification performance of three popular machine learning methods i.e., case-based reasoning, neutral networks and support vector machine to diagnose stress of vehicle drivers using finger temperature and heart rate variability. The experimental results show that case-based reasoning outperforms other two methods in terms of classification accuracy. Case-based reasoning has achieved 80% and 86% accuracy to classify stress using finger temperature and heart rate variability. On contrary, both neural network and support vector machine have achieved less than 80% accuracy by using both physiological signals.

  18. A Cross-Correlated Delay Shift Supervised Learning Method for Spiking Neurons with Application to Interictal Spike Detection in Epilepsy.

    PubMed

    Guo, Lilin; Wang, Zhenzhong; Cabrerizo, Mercedes; Adjouadi, Malek

    2017-05-01

    This study introduces a novel learning algorithm for spiking neurons, called CCDS, which is able to learn and reproduce arbitrary spike patterns in a supervised fashion allowing the processing of spatiotemporal information encoded in the precise timing of spikes. Unlike the Remote Supervised Method (ReSuMe), synapse delays and axonal delays in CCDS are variants which are modulated together with weights during learning. The CCDS rule is both biologically plausible and computationally efficient. The properties of this learning rule are investigated extensively through experimental evaluations in terms of reliability, adaptive learning performance, generality to different neuron models, learning in the presence of noise, effects of its learning parameters and classification performance. Results presented show that the CCDS learning method achieves learning accuracy and learning speed comparable with ReSuMe, but improves classification accuracy when compared to both the Spike Pattern Association Neuron (SPAN) learning rule and the Tempotron learning rule. The merit of CCDS rule is further validated on a practical example involving the automated detection of interictal spikes in EEG records of patients with epilepsy. Results again show that with proper encoding, the CCDS rule achieves good recognition performance.

  19. Associations between Children’s Intelligence and Academic Achievement: The Role of Sleep

    PubMed Central

    Erath, Stephen A.; Tu, Kelly M.; Buckhalt, Joseph A.; El-Sheikh, Mona

    2015-01-01

    Summary Sleep problems (long wake episodes, low sleep efficiency) were examined as moderators of the relation between children’s intelligence and academic achievement. The sample was comprised of 280 children (55% boys; 63% European Americans, 37% African Americans; M age = 10.40 years, SD = .65). Sleep was assessed through seven consecutive nights of actigraphy. Children’s performance on standardized tests of intelligence (Brief Intellectual Ability index of the Woodcock-Johnson III) and academic achievement (Alabama Reading and Math Test) were obtained. Age, sex, ethnicity, income-to-needs ratio, single parent status, zBMI, chronic illness, and pubertal development were controlled in analyses. Higher intelligence was strongly associated with higher academic achievement across a wide range of sleep quality. However, the association between intelligence and academic achievement was slightly attenuated among children with more long wake episodes or lower sleep efficiency compared to children with higher-quality sleep. PMID:25683475

  20. Comparison of evolutionary algorithms for LPDA antenna optimization

    NASA Astrophysics Data System (ADS)

    Lazaridis, Pavlos I.; Tziris, Emmanouil N.; Zaharis, Zaharias D.; Xenos, Thomas D.; Cosmas, John P.; Gallion, Philippe B.; Holmes, Violeta; Glover, Ian A.

    2016-08-01

    A novel approach to broadband log-periodic antenna design is presented, where some of the most powerful evolutionary algorithms are applied and compared for the optimal design of wire log-periodic dipole arrays (LPDA) using Numerical Electromagnetics Code. The target is to achieve an optimal antenna design with respect to maximum gain, gain flatness, front-to-rear ratio (F/R) and standing wave ratio. The parameters of the LPDA optimized are the dipole lengths, the spacing between the dipoles, and the dipole wire diameters. The evolutionary algorithms compared are the Differential Evolution (DE), Particle Swarm (PSO), Taguchi, Invasive Weed (IWO), and Adaptive Invasive Weed Optimization (ADIWO). Superior performance is achieved by the IWO (best results) and PSO (fast convergence) algorithms.

  1. Transonic airfoil analysis and design in nonuniform flow

    NASA Technical Reports Server (NTRS)

    Chang, J. F.; Lan, C. E.

    1986-01-01

    A nonuniform transonic airfoil code is developed for applications in analysis, inverse design and direct optimization involving an airfoil immersed in propfan slipstream. Problems concerning the numerical stability, convergence, divergence and solution oscillations are discussed. The code is validated by comparing with some known results in incompressible flow. A parametric investigation indicates that the airfoil lift-drag ratio can be increased by decreasing the thickness ratio. A better performance can be achieved if the airfoil is located below the slipstream center. Airfoil characteristics designed by the inverse method and a direct optimization are compared. The airfoil designed with the method of direct optimization exhibits better characteristics and achieves a gain of 22 percent in lift-drag ratio with a reduction of 4 percent in thickness.

  2. Prior esophagogastroduodenoscopy does not affect the cecal intubation time at bidirectional endoscopies

    PubMed Central

    Öner, Osman Zekai; Demirci, Rojbin Karakoyun; Gündüz, Umut Rıza; Aslaner, Arif; Koç, Ümit; Bülbüller, Nurullah

    2013-01-01

    Bidirectional endoscopy (BE) is often used to assess patients for the reason of anemia or to screen asymptomatic population for malignancy. Limited clinical data favors to perform first the upper gastrointestinal system endoscopy, but its effect to the duration of colonoscopy is yet to be determined. The aim of this retrospective study is to evaluate the effect of upper gastrointestinal system endoscopy on the time to achieve cecal intubation during colonoscopy in patients undergoing BE. Patients of four endoscopists at similar experience levels were retrospectively identified and categorized into the upper gastrointestinal system endoscopy before colonoscopy group (group 1) or the colonoscopy only group (group 2). The demographics, clinical data and the time to achieve cecal intubation for each patient were analyzed. The mean time to achieve cecal intubation in the first group that included 319 cases was 8.4 ± 0.93 minutes and the mean time in the second group that included 1672 cases was 8.56 ± 1.16 minutes. There was no statistically significant difference between the groups. There was also no significant difference between the Group 1 and Group 2 when compared according to which of the four endoscopists performed the procedures. Performing the upper gastrointestinal system endoscopy prior to colonoscopy did not affect the time to achieve cecal intubation. Considering that performing the upper gastrointestinal system endoscopy prior to the colonoscopy is more advantageous in terms of patient comfort and analgesic requirement, beginning to BE with it seems more favorable. PMID:23936601

  3. Motor imagery training promotes motor learning in adolescents with cerebral palsy: comparison between left and right hemiparesis.

    PubMed

    Cabral-Sequeira, Audrey Sartori; Coelho, Daniel Boari; Teixeira, Luis Augusto

    2016-06-01

    This experiment was designed to evaluate the effects of pure motor imagery training (MIT) and its combination with physical practice on learning an aiming task with the more affected arm in adolescents suffering from cerebral palsy. Effect of MIT was evaluated as a function of side of hemiparesis. The experiment was accomplished by 11- to 16-year-old participants (M = 13.58 years), who suffered left (n = 16) or right (n = 15) mild hemiparesis. They were exposed to pure MIT (day 1) followed by physical practice (day 2) on an aiming task demanding movement accuracy and speed. Posttraining movement kinematics of the group receiving MIT were compared with movement kinematics of the control group after receiving recreational activities (day 1) and physical practice (day 2). Kinematic analysis showed that MIT led to decreased movement time and straighter hand displacements to the target. Performance achievements from MIT were increased with further physical practice, leading to enhanced effects on motor learning. Retention evaluation indicated that performance improvement from pure MIT and its combination with physical practice were stable over time. Performance achievements were equivalent between adolescents with either right or left hemiparesis, suggesting similar capacity between these groups to achieve performance improvement from pure imagery training and from its association with physical practice. Our results suggest that motor imagery training is a procedure potentially useful to increase motor learning achievements in individuals suffering from cerebral palsy.

  4. A clinically guided approach for improving performance measurement for hypertension.

    PubMed

    Steinman, Michael A; Lee, Sei J; Peterson, Carolyn A; Fung, Kathy Z; Goldstein, Mary K

    2012-05-01

    Performance measures often fail to account for legitimate reasons why patients do not achieve recommended treatment targets. We tested a novel performance measurement system for blood pressure (BP) control that was designed to mimic clinical reasoning. This clinically guided approach focuses on (1) exempting patients for whom tight BP control may not be appropriate or feasible and (2) assessing BP over time. Trained abstractors conducted structured chart reviews of 201 adults with hypertension in 2 VA health care systems. Results were compared with traditional methods of performance measurement. Among 201 veterans, 183 (91%) were male, and the mean age was 71±11 years. Using the clinically guided approach, 61 patients (30%) were exempted from performance measurement. The most common reasons for exemption were inadequate opportunity to manage BP (35 patients, 17%) and the use of 4 or more antihypertensive medications (19 patients, 9%). Among patients eligible for performance measurement, there was little agreement on the presence of controlled versus uncontrolled BP when comparing the most recent BP (the traditional approach) with an integrated assessment of BP control (κ 0.14). After accounting for clinically guided exemptions and methods of BP assessment, only 15 of 72 patients (21%) whose last BP was ≥140/90 mm Hg were classified as problematic by the clinically guided approach. Many patients have legitimate reasons for not achieving tight BP control, and the methods used for BP assessment have marked effects on whether a patient is classified as having adequate or inadequate BP control.

  5. Improving La0.6Sr0.4Co0.8Fe0.2O3-δ infiltrated solid oxide fuel cell cathode performance through precursor solution desiccation

    NASA Astrophysics Data System (ADS)

    Burye, Theodore E.; Nicholas, Jason D.

    2015-02-01

    Here, for the first time, the average size of solid oxide fuel cell (SOFC) electrode nano-particles was reduced through the chemical desiccation of infiltrated precursor nitrate solutions. Specifically, after firing at 700 °C, CaCl2-desiccated La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF) - Ce0.9Gd0.1O1.95 (GDC) cathodes contained LSCF infiltrate particles with an average size of 22 nm. This is in contrast to comparable, undesiccated LSCF-GDC cathodes which contained LSCF infiltrate particles with an average size of 48 nm. X-ray diffraction, scanning electron microscopy, and controlled atmosphere electrochemical impedance spectroscopy revealed that desiccation reduced the average infiltrate particle size without altering the infiltrate phase purity, the cathode concentration polarization resistance, or the cathode electronic resistance. Compared to undesiccated LSCF-GDC cathodes achieving polarization resistances of 0.10 Ωcm2 at 640 °C, comparable CaCl2-dessicated LSCF-GDC cathodes achieved 0.10 Ωcm2 at 575 °C. Mathematical modeling suggested that these performance improvements resulted solely from average infiltrate particle size reductions.

  6. Effect of Treat-to-target Strategies Aiming at Remission of Arterial Stiffness in Early Rheumatoid Arthritis: A Randomized Controlled Study.

    PubMed

    Tam, Lydia Ho-Pui; Shang, Qing; Li, Edmund Kwok-Ming; Wong, Priscilla Ching-Han; Kwok, Kitty Yan; Kun, Emily Wai-Lin; Yim, Isaac Cheuk-Wan; Lee, Violet Ka-Lai; Yip, Ronald Man-Lung; Pang, Steve Hin-Ting; Lao, Virginia Weng-Nga; Mak, Queenie Wah-Yan; Cheng, Isaac Tsz-Ho; Lau, Xerox Sze-Lok; Li, Tena Ka-Yan; Zhu, Tracy Yaner; Lee, Alex Pui-Wai; Tam, Lai-Shan

    2018-05-15

    To determine the efficacy of 2 tight control treatment strategies aiming at Simplified Disease Activity Score (SDAI) remission (SDAI ≤ 3.3) compared to 28-joint count Disease Activity Score (DAS28) remission (DAS28 < 2.6) in the prevention of arterial stiffness in patients with early rheumatoid arthritis (RA). This was an open-label study in which 120 patients with early RA were randomized to receive 1 year of tight control treatment. Group 1 (n = 60) aimed to achieve SDAI ≤ 3.3 and Group 2 (n = 60), DAS28 < 2.6. Pulse wave velocity (PWV) and augmentation index (AIx) were measured at baseline and 12 months. A posthoc analysis was also performed to ascertain whether achieving sustained remission could prevent progression in arterial stiffness. The proportions of patients receiving methotrexate monotherapy were significantly lower in Group 1 throughout the study period. At 12 months, the proportions of patients achieving DAS28 and SDAI remission, and the change in PWV and AIx, were comparable between the 2 groups. In view of the lack of differences between the 2 groups, a posthoc analysis was performed at Month 12, including all 110 patients with PWV, to elucidate the independent predictors associated with the change in PWV. Multivariate analysis revealed that achieving sustained DAS28 remission at months 6, 9, and 12 and a shorter disease duration were independent explanatory variables associated with less progression of PWV. With limited access to biologic disease-modifying antirheumatic drugs, treatment efforts toward DAS28 and SDAI remission had similar effects in preventing the progression of arterial stiffness at 1 year. However, achieving sustained DAS28 remission was associated with a significantly greater improvement in PWV. [Clinical Trial registration: Clinicaltrial.gov NCT01768923.].

  7. A simulation-based study of HighSpeed TCP and its deployment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Souza, Evandro de

    2003-05-01

    The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simulation results showing the performance of HighSpeed TCP and the impact of its use on the present implementation of TCP are presented. Network conditions includingmore » different degrees of congestion, different levels of loss rate, different degrees of bursty traffic and two distinct router queue management policies were simulated. The performance and fairness of HighSpeed TCP were compared to the existing TCP and solutions for bulk-data transfer using parallel streams.« less

  8. Alternate Lattice Design for Advanced Photon Source Multi-Bend Achromat Upgrade

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sun, Yipeng; Borland, Michael

    2015-01-01

    A 67-pm hybrid-seven-bend achromat (H7BA) lattice is proposed for a futureAdvanced Photon Source (APS)multibend- achromat (MBA) upgrade. This lattice requires use of a swap-out (on-axis) injection scheme. Alternate lattice design work has also been performed to achieve better beam dynamics performance than the nominal APS MBA lattice, in order to allow beam accumulation. One of such alternate H7BA lattice designs, which still targets a very low emittance of 76 pm, is discussed in this paper. With these lattices, existing APS injector complex can be employed without the requirement of a very high charge operation. Studies show that an emittance belowmore » 76 pm can be achieved with the employment of reverse bends in an alternate lattice. We discuss the predicted performance and requirements for these lattices and compare them to the nominal lattice.« less

  9. Solution-Processed Small-Molecule Bulk Heterojunctions: Leakage Currents and the Dewetting Issue for Inverted Solar Cells.

    PubMed

    Destouesse, Elodie; Chambon, Sylvain; Courtel, Stéphanie; Hirsch, Lionel; Wantz, Guillaume

    2015-11-11

    In organic photovoltaic (PV) devices based on solution-processed small molecules, we report here that the physicochemical properties of the substrate are critical for achieving high-performances organic solar cells. Three different substrates were tested: ITO coated with PSS, ZnO sol-gel, and ZnO nanoparticles. PV performances are found to be low when the ZnO nanoparticles layer is used. This performance loss is attributed to the formation of many dewetting points in the active layer, because of a relatively high roughness of the ZnO nanoparticles layer, compared to the other layers. We successfully circumvented this phenomenon by adding a small quantity of polystyrene (PS) in the active layer. The introduction of PS improves the quality of film forming and reduces the dark currents of solar cells. Using this method, high-efficiency devices were achieved, even in the case of substrates with higher roughness.

  10. Integrated function nonimaging concentrating collector tubes for solar thermal energy

    NASA Astrophysics Data System (ADS)

    Winston, R.; Ogallagher, J. J.

    1982-09-01

    A substantial improvement in optical efficiency over contemporary external reflector evacuated tube collectors has been achieved by integrating the reflector surface into the outer glass envelope. Described are the design fabrication and test results for a prototype collector based on this concept. A comprehensive test program to measure performance and operational characteristics of a 2 sq m panel (45 tubes) has been completed. Efficiencies above 50% relative to beam at 200 C have been repeatedly demonstrated. Both the instantaneous and long term average performance of this totally stationary solar collector are comparable to those for tracking line focus parabolic troughs. The yield, reliability and stability of performance achieved have been excellent. Subcomponent assemblies and fabrication procedures have been used which are expected to be compatible with high volume production. The collector has a wide variety of applications in the 100 to 300 C range including industrial progress heat, air conditioning and Rankine engine operation.

  11. Multidimensional evaluation of performance with experimental application of balanced scorecard: a two year experience

    PubMed Central

    2011-01-01

    Background In today's dynamic health-care system, organizations such as hospitals are required to improve their performance for multiple stakeholders and deliver an integrated care that means to work effectively, be innovative and organize efficiently. Achieved goals and levels of quality can be successfully measured by a multidimensional approach like Balanced Scorecard (BSC). The aim of the study was to verify the opportunity to introduce BSC framework to measure performance in St. Anna University Hospital of Ferrara, applying it to the Clinical Laboratory Operative Unit in order to compare over time performance results and achievements of assigned targets. Methods In the first experience with BSC we distinguished four perspectives, according to Kaplan and Norton, identified Key Performance Areas and Key Performance Indicators, set standards and weights for each objective, collected data for all indicators, recognized cause-and-effect relationships in a strategic map. One year later we proceeded with the next data collection and analysed the preservation of framework aptitude to measure Operative Unit performance. In addition, we verified the ability to underline links between strategic actions belonging to different perspectives in producing outcomes changes. Results The BSC was found to be effective for underlining existing problems and identifying opportunities for improvements. The BSC also revealed the specific perspective contribution to overall performance enhancement. After time results comparison was possible depending on the selection of feasible and appropriate key performance indicators, which was occasionally limited by data collection problems. Conclusions The first use of BSC to compare performance at Operative Unit level, in course of time, suggested this framework can be successfully adopted for results measuring and revealing effective health factors, allowing health-care quality improvements. PMID:21586111

  12. Multidimensional evaluation of performance with experimental application of balanced scorecard: a two year experience.

    PubMed

    Lupi, Silvia; Verzola, Adriano; Carandina, Gianni; Salani, Manuela; Antonioli, Paola; Gregorio, Pasquale

    2011-05-17

    In today's dynamic health-care system, organizations such as hospitals are required to improve their performance for multiple stakeholders and deliver an integrated care that means to work effectively, be innovative and organize efficiently. Achieved goals and levels of quality can be successfully measured by a multidimensional approach like Balanced Scorecard (BSC). The aim of the study was to verify the opportunity to introduce BSC framework to measure performance in St. Anna University Hospital of Ferrara, applying it to the Clinical Laboratory Operative Unit in order to compare over time performance results and achievements of assigned targets. In the first experience with BSC we distinguished four perspectives, according to Kaplan and Norton, identified Key Performance Areas and Key Performance Indicators, set standards and weights for each objective, collected data for all indicators, recognized cause-and-effect relationships in a strategic map. One year later we proceeded with the next data collection and analysed the preservation of framework aptitude to measure Operative Unit performance. In addition, we verified the ability to underline links between strategic actions belonging to different perspectives in producing outcomes changes. The BSC was found to be effective for underlining existing problems and identifying opportunities for improvements. The BSC also revealed the specific perspective contribution to overall performance enhancement. After time results comparison was possible depending on the selection of feasible and appropriate key performance indicators, which was occasionally limited by data collection problems. The first use of BSC to compare performance at Operative Unit level, in course of time, suggested this framework can be successfully adopted for results measuring and revealing effective health factors, allowing health-care quality improvements.

  13. Bootstrapping a de-identification system for narrative patient records: cost-performance tradeoffs.

    PubMed

    Hanauer, David; Aberdeen, John; Bayer, Samuel; Wellner, Benjamin; Clark, Cheryl; Zheng, Kai; Hirschman, Lynette

    2013-09-01

    We describe an experiment to build a de-identification system for clinical records using the open source MITRE Identification Scrubber Toolkit (MIST). We quantify the human annotation effort needed to produce a system that de-identifies at high accuracy. Using two types of clinical records (history and physical notes, and social work notes), we iteratively built statistical de-identification models by annotating 10 notes, training a model, applying the model to another 10 notes, correcting the model's output, and training from the resulting larger set of annotated notes. This was repeated for 20 rounds of 10 notes each, and then an additional 6 rounds of 20 notes each, and a final round of 40 notes. At each stage, we measured precision, recall, and F-score, and compared these to the amount of annotation time needed to complete the round. After the initial 10-note round (33min of annotation time) we achieved an F-score of 0.89. After just over 8h of annotation time (round 21) we achieved an F-score of 0.95. Number of annotation actions needed, as well as time needed, decreased in later rounds as model performance improved. Accuracy on history and physical notes exceeded that of social work notes, suggesting that the wider variety and contexts for protected health information (PHI) in social work notes is more difficult to model. It is possible, with modest effort, to build a functioning de-identification system de novo using the MIST framework. The resulting system achieved performance comparable to other high-performing de-identification systems. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Exploring the Architectural Tradespace of Severe Weather Monitoring Nanosatellite Constellations

    NASA Astrophysics Data System (ADS)

    Hitomi, N.; Selva, D.; Blackwell, W. J.

    2014-12-01

    MicroMAS-1, a 3U nanosatellite developed by MIT/LL, MIT/SSL, and University of Massachusetts, was launched on July 13, 2014 and is scheduled for deployment from the International Space Station in September. The development of MicroMAS motivates an architectural analysis of a constellation of nanosatellites with the goal of drastically reducing the cost of observing severe storms compared with current monolithic missions such as the Precision and All-Weather Temperature and Humidity (PATH) mission from the NASA Decadal Survey. Our goal is to evolve the instrument capability on weather monitoring nanosatellites to achieve higher performance and better satisfy stakeholder needs. Clear definitions of performance requirements are critical in the conceptual design phase when much of the project's lifecycle cost and performance will be fixed. Ability to perform trade studies and optimization of performance needs with instrument capability will enable design teams to focus on key technologies that will introduce high value and high return on investment. In this work, we approach the significant trades and trends of constellations for monitoring severe storms by applying our rule-based decision support tool. We examine a subset of stakeholder groups listed in the OSCAR online database (e.g., weather, climate) that would benefit from severe storm weather data and their respective observation requirements (e.g. spatial resolution, accuracy). We use ten parameters in our analysis, including atmospheric temperature, humidity, and precipitation. We compare the performance and cost of thousands of different possible constellations. The constellations support hyperspectral sounders that cover different portions of the millimeter-wave spectrum (50-60 GHz, 118GHz, 183GHz) in different orbits, and the performance results are compared against those of the monolithic PATH mission. Our preliminary results indicate that constellations using the hyperspectral millimeter wave sounders can better satisfy stakeholder needs compared to the PATH mission. Well-architected constellations have increased coverage, improved horizontal resolution from lower orbits, and improved temporal resolution. Furthermore, this improved performance can be achieved at a lower cost than what is estimated for the PATH mission.

  15. Origin of vertical orientation in two-dimensional metal halide perovskites and its effect on photovoltaic performance.

    PubMed

    Chen, Alexander Z; Shiu, Michelle; Ma, Jennifer H; Alpert, Matthew R; Zhang, Depei; Foley, Benjamin J; Smilgies, Detlef-M; Lee, Seung-Hun; Choi, Joshua J

    2018-04-06

    Thin films based on two-dimensional metal halide perovskites have achieved exceptional performance and stability in numerous optoelectronic device applications. Simple solution processing of the 2D perovskite provides opportunities for manufacturing devices at drastically lower cost compared to current commercial technologies. A key to high device performance is to align the 2D perovskite layers, during the solution processing, vertical to the electrodes to achieve efficient charge transport. However, it is yet to be understood how the counter-intuitive vertical orientations of 2D perovskite layers on substrates can be obtained. Here we report a formation mechanism of such vertically orientated 2D perovskite in which the nucleation and growth arise from the liquid-air interface. As a consequence, choice of substrates can be liberal from polymers to metal oxides depending on targeted application. We also demonstrate control over the degree of preferential orientation of the 2D perovskite layers and its drastic impact on device performance.

  16. The family environment predicts long-term academic achievement and classroom behavior following traumatic brain injury in early childhood.

    PubMed

    Durber, Chelsea M; Yeates, Keith Owen; Taylor, H Gerry; Walz, Nicolay Chertkoff; Stancin, Terry; Wade, Shari L

    2017-07-01

    This study examined how the family environment predicts long-term academic and behavioral functioning in school following traumatic brain injury (TBI) in early childhood. Using a concurrent cohort, prospective design, 15 children with severe TBI, 39 with moderate TBI, and 70 with orthopedic injury (OI) who were injured when they were 3-7 years of age were compared on tests of academic achievement and parent and teacher ratings of school performance and behavior on average 6.83 years postinjury. Soon after injury and at the longer term follow-up, families completed measures of parental psychological distress, family functioning, and quality of the home environment. Hierarchical linear regression analyses examined group differences in academic outcomes and their associations with measures of the early and later family environment. The severe TBI group, but not the moderate TBI group, performed worse than did the OI group on all achievement tests, parent ratings of academic performance, and teacher ratings of internalizing problems. Higher quality early and late home environments predicted stronger academic skills and better classroom behavior for children with both TBI and OI. The early family environment more consistently predicted academic achievement, whereas the later family environment more consistently predicted classroom functioning. The quality of the home environment predicted academic outcomes more strongly than did parental psychological distress or family functioning. TBI in early childhood has long-term consequences for academic achievement and school performance and behavior. Higher quality early and later home environments predict better school outcomes for both children with TBI and children with OI. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. The Relationship between School Absence, Academic Performance, and Asthma Status

    ERIC Educational Resources Information Center

    Moonie, Sheniz; Sterling, David A.; Figgs, Larry W.; Castro, Mario

    2008-01-01

    Background: Children with asthma experience more absenteeism from school compared with their nonasthma peers. Excessive absenteeism is related to lower student grades, psychological, social, and educational adjustment. Less is known about the relationship between the presence of asthma and the academic achievement in school-aged children. Since…

  18. Academic Achievement and Emotional Status of Children with ADHD Treated with Long-Term Methylphenidate and Multimodal Psychosocial Treatment

    ERIC Educational Resources Information Center

    Hechtman, Lily; Abikoff, Howard; Klein, Rachel G.; Weiss, Gabrielle; Respitz, Chara; Kouri, Joan; Blum, Carol; Greenfield, Brian; Etcovitch, Joy; Fleiss, Karen; Pollack, Simcha

    2004-01-01

    Objective: To test the hypothesis that intensive multimodal psychosocial intervention (that includes academic assistance and psychotherapy) combined with methylphenidate significantly enhances the academic performance and emotional status of children with attention-deficit/hyperactivity disorder (ADHD) compared with methylphenidate alone and with…

  19. Increasing Prosocial Behavior and Academic Achievement among Adolescent African American Males

    ERIC Educational Resources Information Center

    Martin, Don; Martin, Magy; Gibson, Suzanne Semivan; Wilkins, Jonathan

    2007-01-01

    African American adolescents disproportionately perform poorly compared to peers in both behavioral and academic aspects of their educational experience. In this study, African American male students participated in an after-school program involving tutoring, group counseling, and various enrichment activities. All students were assessed regarding…

  20. Effects of a Math Intervention Program on Math Academic Performance among African American Students

    ERIC Educational Resources Information Center

    Johnson, Willie F., Jr.

    2013-01-01

    In the United States, an academic achievement gap has prevented many African American students from advancement and educational empowerment. Guided by Bandura's theoretical belief, which posits a relationship between social factors and an individual's perception, this non-experimental, causal comparative, control treatment group design study…

  1. Achievement and School Behavior among Children with Epilepsy.

    ERIC Educational Resources Information Center

    Matthews, Wendy S.; And Others

    1983-01-01

    Compared the school behavior of 15 epileptic children with that of diabetic and healthy children. The epileptic children were more likely to attribute the success or failure of their school performance to unknown sources of control, and to hold less positive feelings about school and their own self-worth. (Author)

  2. Comparative Predictive Validity of the New MCAT Using Different Admissions Criteria.

    ERIC Educational Resources Information Center

    Golmon, Melton E.; Berry, Charles A.

    1981-01-01

    New Medical College Admission Test (MCAT) scores and undergraduate academic achievement were examined for their validity in predicting the performance of two select student populations at Northwestern University Medical School. The data support the hypothesis that New MCAT scores possess substantial predictive validity. (Author/MLW)

  3. Practice Behaviors of Eighth-Grade Instrumental Musicians

    ERIC Educational Resources Information Center

    Rohwer, Debbie; Polk, Jeremy

    2006-01-01

    The purposes of the current study were to (1) determine the relationship between the number of practice strategies students could articulate and their performance improvement scores, (2) identify trends in students' 5-minute practice behaviors, and (3) compare students' achievement based on their practice procedures. Participants were 65 eighth…

  4. Specific Intellectual Deficits in Children with Early Onset Diabetes Mellitus.

    ERIC Educational Resources Information Center

    Rovet, Joanne F.; And Others

    1988-01-01

    Compares 27 children with early onset diabetes (EOD) with 24 children with late onset diabetes (LOD) and 30 sibling controls in performance on tests of intellectual functioning and school achievement. Results revealed that duration of illness, age of onset, and hypoglycemic convulsions significantly predicted spatial ability. (Author/RWB)

  5. School Effects on Performance of Minority Pupils.

    ERIC Educational Resources Information Center

    Hofman, W. H. Adriaan

    1994-01-01

    Presents results of a study examining the comparative effects of school (system) determinants on the educational careers of minority students in the Netherlands, drawing on rational choice and empowerment theories. Results indicate the importance of a school policy aimed at improving minority student achievement. Pull-out programs are detrimental,…

  6. Effects of Instruction and Stage-Fright on Intelligence Testing

    ERIC Educational Resources Information Center

    Meijer, Joost; Oostdam, Ron

    2011-01-01

    In the present research, it was tried to unravel the influence of various types of instruction on test anxiety levels and, in turn, its influence on intelligence test performance. Three types of instruction were compared: a stressful, achievement-orientated instruction; a reassuring, task-orientated instruction; and an ambiguous instruction.…

  7. Intellectual Development of Students at the Secondary-College Interface in Lebanon.

    ERIC Educational Resources Information Center

    Za'rour, George I.; Gholam, Ghada K.

    1981-01-01

    Assesses the level of intellectual development in proportional, combinatorial, and correlational reasoning and the ability to control variables in beginning sophomore students (N=207) at the American University of Beirut, Lebanon. Compares this level with their performance on achievement tests in mathematics, biology, chemistry, and physics. (CS)

  8. Music Training and Mathematics Achievement.

    ERIC Educational Resources Information Center

    Cheek, Joyce M.; Smith, Lyle R.

    1999-01-01

    Iowa Tests of Basic Skills (ITBS) mathematics scores of eighth graders who had received music instruction were compared according to whether the students were given private lessons. Analyses indicate that students who had private lessons for two or more years performed significantly better on the composite mathematics portion of the ITBS than did…

  9. Cautions about Inferences from International Assessments: The Case of PISA 2009

    ERIC Educational Resources Information Center

    Ercikan, Kadriye; Roth, Wolff-Michael; Asil, Mustafa

    2015-01-01

    Background/Context: Two key uses of international assessments of achievement have been (a) comparing country performances for identifying the countries with the best education systems and (2) generating insights about effective policy and practice strategies that are associated with higher learning outcomes. Do country rankings really reflect the…

  10. Bond expectations for milled surfaces and typical tack coat materials used in Virginia.

    DOT National Transportation Integrated Search

    2009-01-01

    The ultimate purpose of the program of research of which this study was a part is to identify a test method and acceptance criteria for bonding of HMA layers. In this study, three tasks were performed to help achieve that purpose: a laboratory compar...

  11. A Comparative Analysis of the Efficiency of National Education Systems

    ERIC Educational Resources Information Center

    Thieme, Claudio; Gimenez, Victor; Prior, Diego

    2012-01-01

    The present study assesses the performance of 54 participating countries in PISA 2006. It employs efficiency indicators that relate result variables with resource variables used in the production of educational services. Desirable outputs of educational achievement and undesirable outputs of educational inequality are considered jointly as result…

  12. Against Conventional Wisdom: Factors Influencing Hispanic Students' Reading Achievement

    ERIC Educational Resources Information Center

    Percell, Jay C.; Kaufman, Kristina

    2013-01-01

    The researchers performed a variable analysis of the 2002 Educational Longitudinal Study data investigating factors that influence students' reading scores on standardized tests. Hispanic and non-Hispanic Scores were analyzed and controlling variables were compared to determine the effect of each on both populations. Certain variables commonly…

  13. The Impact of Internet Virtual Physics Laboratory Instruction on the Achievement in Physics, Science Process Skills and Computer Attitudes of 10th-Grade Students

    NASA Astrophysics Data System (ADS)

    Yang, Kun-Yuan; Heh, Jia-Sheng

    2007-10-01

    The purpose of this study was to investigate and compare the impact of Internet Virtual Physics Laboratory (IVPL) instruction with traditional laboratory instruction in physics academic achievement, performance of science process skills, and computer attitudes of tenth grade students. One-hundred and fifty students from four classes at one private senior high school in Taoyuan Country, Taiwan, R.O.C. were sampled. All four classes contained 75 students who were equally divided into an experimental group and a control group. The pre-test results indicated that the students' entry-level physics academic achievement, science process skills, and computer attitudes were equal for both groups. On the post-test, the experimental group achieved significantly higher mean scores in physics academic achievement and science process skills. There was no significant difference in computer attitudes between the groups. We concluded that the IVPL had potential to help tenth graders improve their physics academic achievement and science process skills.

  14. Low-temperature operation of a Buck DC/DC converter

    NASA Technical Reports Server (NTRS)

    Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

    1995-01-01

    Low-temperature (77 K) operation of a 42/28 V, 175 W, 50 kHz PWM Buck DC/DC converter designed with commercially available components is reported. Overall, the converter losses decreased at 77 K compared to room temperature operation. A full-load efficiency of 97 percent was recorded at liquid-nitrogen temperature, compared to 95.8 percent at room temperature. Power MOSFET operation improved significantly where as the output rectifier operation deteriorated at low-temperature. The performance of the output filter inductor and capacitor did not change significantly at 77 K compared to room temperature performance. It is possible to achieve high-density and high efficiency power conversion at low-temperatures due to improved electronic, electrical and thermal properties of materials.

  15. A performance comparison of current HPC systems: Blue Gene/Q, Cray XE6 and InfiniBand systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kerbyson, Darren J.; Barker, Kevin J.; Vishnu, Abhinav

    2014-01-01

    We present here a performance analysis of three of current architectures that have become commonplace in the High Performance Computing world. Blue Gene/Q is the third generation of systems from IBM that use modestly performing cores but at large-scale in order to achieve high performance. The XE6 is the latest in a long line of Cray systems that use a 3-D topology but the first to use its Gemini interconnection network. InfiniBand provides the flexibility of using compute nodes from many vendors that can be connected in many possible topologies. The performance characteristics of each vary vastly, and the waymore » in which nodes are allocated in each type of system can significantly impact on achieved performance. In this work we compare these three systems using a combination of micro-benchmarks and a set of production applications. In addition we also examine the differences in performance variability observed on each system and quantify the lost performance using a combination of both empirical measurements and performance models. Our results show that significant performance can be lost in normal production operation of the Cray XE6 and InfiniBand Clusters in comparison to Blue Gene/Q.« less

  16. CUDA Optimization Strategies for Compute- and Memory-Bound Neuroimaging Algorithms

    PubMed Central

    Lee, Daren; Dinov, Ivo; Dong, Bin; Gutman, Boris; Yanovsky, Igor; Toga, Arthur W.

    2011-01-01

    As neuroimaging algorithms and technology continue to grow faster than CPU performance in complexity and image resolution, data-parallel computing methods will be increasingly important. The high performance, data-parallel architecture of modern graphical processing units (GPUs) can reduce computational times by orders of magnitude. However, its massively threaded architecture introduces challenges when GPU resources are exceeded. This paper presents optimization strategies for compute- and memory-bound algorithms for the CUDA architecture. For compute-bound algorithms, the registers are reduced through variable reuse via shared memory and the data throughput is increased through heavier thread workloads and maximizing the thread configuration for a single thread block per multiprocessor. For memory-bound algorithms, fitting the data into the fast but limited GPU resources is achieved through reorganizing the data into self-contained structures and employing a multi-pass approach. Memory latencies are reduced by selecting memory resources whose cache performance are optimized for the algorithm's access patterns. We demonstrate the strategies on two computationally expensive algorithms and achieve optimized GPU implementations that perform up to 6× faster than unoptimized ones. Compared to CPU implementations, we achieve peak GPU speedups of 129× for the 3D unbiased nonlinear image registration technique and 93× for the non-local means surface denoising algorithm. PMID:21159404

  17. CUDA optimization strategies for compute- and memory-bound neuroimaging algorithms.

    PubMed

    Lee, Daren; Dinov, Ivo; Dong, Bin; Gutman, Boris; Yanovsky, Igor; Toga, Arthur W

    2012-06-01

    As neuroimaging algorithms and technology continue to grow faster than CPU performance in complexity and image resolution, data-parallel computing methods will be increasingly important. The high performance, data-parallel architecture of modern graphical processing units (GPUs) can reduce computational times by orders of magnitude. However, its massively threaded architecture introduces challenges when GPU resources are exceeded. This paper presents optimization strategies for compute- and memory-bound algorithms for the CUDA architecture. For compute-bound algorithms, the registers are reduced through variable reuse via shared memory and the data throughput is increased through heavier thread workloads and maximizing the thread configuration for a single thread block per multiprocessor. For memory-bound algorithms, fitting the data into the fast but limited GPU resources is achieved through reorganizing the data into self-contained structures and employing a multi-pass approach. Memory latencies are reduced by selecting memory resources whose cache performance are optimized for the algorithm's access patterns. We demonstrate the strategies on two computationally expensive algorithms and achieve optimized GPU implementations that perform up to 6× faster than unoptimized ones. Compared to CPU implementations, we achieve peak GPU speedups of 129× for the 3D unbiased nonlinear image registration technique and 93× for the non-local means surface denoising algorithm. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. A comparison of lamellar and penetrating keratoplasty outcomes: a registry study.

    PubMed

    Coster, Douglas J; Lowe, Marie T; Keane, Miriam C; Williams, Keryn A

    2014-05-01

    To investigate changing patterns of practice of keratoplasty in Australia, graft survival, visual outcomes, the influence of experience, and the surgeon learning curve for endothelial keratoplasty. Observational, prospective cohort study. From a long-standing national corneal transplantation register, 13 920 penetrating keratoplasties, 858 deep anterior lamellar keratoplasties (DALKs), and 2287 endokeratoplasties performed between January 1996 and February 2013 were identified. Kaplan-Meier functions were used to assess graft survival and surgeon experience, the Pearson chi-square test was used to compare visual acuities, and linear regression was used to examine learning curves. Graft survival. The total number of corneal grafts performed annually is increasing steadily. More DALKs but fewer penetrating grafts are being performed for keratoconus, and more endokeratoplasties but fewer penetrating grafts are being performed for Fuchs' dystrophy and pseudophakic bullous keratopathy. In 2012, 1482 grafts were performed, compared with 955 in 2002, translating to a requirement for 264 extra corneal donors across the country in 2012. Comparing penetrating grafts and DALKs performed for keratoconus over the same era, both graft survival (P <0.001) and visual outcomes (P <0.001) were significantly better for penetrating grafts. Survival of endokeratoplasties performed for Fuchs' dystrophy or pseudophakic bullous keratopathy was poorer than survival of penetrating grafts for the same indications over the same era (P <0.001). Visual outcomes were significantly better for penetrating grafts than for endokeratoplasties performed for Fuchs' dystrophy (P <0.001), but endokeratoplasties achieved better visual outcomes than penetrating grafts for pseudophakic bullous keratopathy (P <0.001). Experienced surgeons (>100 registered keratoplasties) achieved significantly better survival of endokeratoplasties (P <0.001) than surgeons who had performed fewer grafts (<100 registered keratoplasties). In the hands of experienced, high-volume surgeons, endokeratoplasty failures occurred even after 100 grafts had been performed. More corneal transplants, especially DALKs and endokeratoplasties, are being performed in Australia than ever before. Survival of DALKs and endokeratoplasties is worse than the survival of penetrating grafts performed for the same indications over the same timeframe. Many endokeratoplasties fail early, but the evidence for a surgeon learning curve is unconvincing. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  19. Experimental investigation of extended Kalman Filter combined with carrier phase recovery for 16-QAM system

    NASA Astrophysics Data System (ADS)

    Shu, Tong; Li, Yan; Yu, Miao; Zhang, Yifan; Zhou, Honghang; Qiu, Jifang; Guo, Hongxiang; Hong, Xiaobin; Wu, Jian

    2018-02-01

    Performance of Extended Kalman Filter combined with the Viterbi-Viterbi phase estimation (VVPE-EKF) for joint phase noise mitigation and amplitude noise equalization is experimental demonstrated. Experimental results show that, for 11.2 Gbaud SP-16-QAM, the proposed VVPE-EKF achieves 0.9 dB required OSNR reduction at bit error ratio (BER) of 3.8e-3 compared to the VVPE. The result of maximum likelihood combined with VVPE (VVPE-ML) is only 0.3 dB. For 28 GBaud SP-16-QAM signal, VVPE-EKF achieves 3 dB required OSNR reduction at BER=3.8e-3 (7% HD-FEC threshold) compared to VVPE. And VVPE-ML can reduce the required OSNR for 1.7 dB compared to the VVPE. VVPE-EKF outperforms DD-EKF 3.7 dB and 0.7 dB for 11.2 GBaud and 28 GBaud system, respectively.

  20. Long-term Effectiveness of Online Anaphylaxis Education for Pharmacists

    PubMed Central

    Vale, Sandra; Sanfilippo, Frank M; Loh, Richard; Clifford, Rhonda M

    2014-01-01

    Objective. To evaluate the long-term effectiveness of an Australasian Society of Clinical Immunology and Allergy (ASCIA) anaphylaxis e-learning program compared to lectures or no training. Design. A controlled interrupted-time-series study of Australian pharmacists and pharmacy students who completed ASCIA anaphylaxis e-learning or lecture programs was conducted during 2011-2013. Effectiveness was measured using a validated test administered pretraining, posttraining, and 3 and 7 months after training. Assessment. All learning groups performed significantly better on all posttests compared to the pretest, and compared to a control group (p<0.001). The proportion of e-learners achieving the minimum standard for anaphylaxis knowledge improved from 45% at pretest to 87% at 7 months. Conclusion. The ASCIA e-learning program significantly increased anaphylaxis knowledge. The high proportion of participants achieving the minimum standard at 7 months indicates long-term knowledge change. PMID:25258441

  1. Probability workshop to be better in probability topic

    NASA Astrophysics Data System (ADS)

    Asmat, Aszila; Ujang, Suriyati; Wahid, Sharifah Norhuda Syed

    2015-02-01

    The purpose of the present study was to examine whether statistics anxiety and attitudes towards probability topic among students in higher education level have an effect on their performance. 62 fourth semester science students were given statistics anxiety questionnaires about their perception towards probability topic. Result indicated that students' performance in probability topic is not related to anxiety level, which means that the higher level in statistics anxiety will not cause lower score in probability topic performance. The study also revealed that motivated students gained from probability workshop ensure that their performance in probability topic shows a positive improvement compared before the workshop. In addition there exists a significance difference in students' performance between genders with better achievement among female students compared to male students. Thus, more initiatives in learning programs with different teaching approaches is needed to provide useful information in improving student learning outcome in higher learning institution.

  2. Achievement Goals in a Presentation Task: Performance Expectancy, Achievement Goals, State Anxiety, and Task Performance

    ERIC Educational Resources Information Center

    Tanaka, Ayumi; Takehara, Takuma; Yamauchi, Hirotsugu

    2006-01-01

    The aims of the study were to test the linkages between achievement goals to task performance, as mediated by state anxiety arousal. Performance expectancy was also examined as antecedents of achievement goals. A presentation task in a computer practice class was used as achievement task. Fifty-three undergraduates (37 females and 16 males) were…

  3. Thermal evaluation of advanced solar dynamic heat receiver performance

    NASA Technical Reports Server (NTRS)

    Crane, Roger A.

    1989-01-01

    The thermal performance of a variety of concepts for thermal energy storage as applied to solar dynamic applications is discussed. It is recognized that designs providing large thermal gradients or large temperature swings during orbit are susceptible to early mechanical failure. Concepts incorporating heat pipe technology may encounter operational limitations over sufficiently large ranges. By reviewing the thermal performance of basic designs, the relative merits of the basic concepts are compared. In addition the effect of thermal enhancement and metal utilization as applied to each design provides a partial characterization of the performance improvements to be achieved by developing these technologies.

  4. Why do water quality monitoring programs succeed or fail? A qualitative comparative analysis of regulated testing systems in sub-Saharan Africa.

    PubMed

    Peletz, Rachel; Kisiangani, Joyce; Bonham, Mateyo; Ronoh, Patrick; Delaire, Caroline; Kumpel, Emily; Marks, Sara; Khush, Ranjiv

    2018-05-31

    Water quality testing is critical for guiding water safety management and ensuring public health. In many settings, however, water suppliers and surveillance agencies do not meet regulatory requirements for testing frequencies. This study examines the conditions that promote successful water quality monitoring in Africa, with the goal of providing evidence for strengthening regulated water quality testing programs. We compared monitoring programs among 26 regulated water suppliers and surveillance agencies across six African countries. These institutions submitted monthly water quality testing results over 18 months. We also collected qualitative data on the conditions that influenced testing performance via approximately 821 h of semi-structured interviews and observations. Based on our qualitative data, we developed the Water Capacity Rating Diagnostic (WaterCaRD) to establish a scoring framework for evaluating the effects of the following conditions on testing performance: accountability, staffing, program structure, finances, and equipment & services. We summarized the qualitative data into case studies for each of the 26 institutions and then used the case studies to score the institutions against the conditions captured in WaterCaRD. Subsequently, we applied fuzzy-set Qualitative Comparative Analysis (fsQCA) to compare these scores against performance outcomes for water quality testing. We defined the performance outcomes as the proportion of testing Targets Achieved (outcome 1) and Testing Consistency (outcome 2) based on the monthly number of microbial water quality tests conducted by each institution. Our analysis identified motivation & leadership, knowledge, staff retention, and transport as institutional conditions that were necessary for achieving monitoring targets. In addition, equipment, procurement, infrastructure, and enforcement contributed to the pathways that resulted in strong monitoring performance. Our identification of institutional commitment, comprising motivation & leadership, knowledge, and staff retention, as a key driver of monitoring performance was not surprising: in weak regulatory environments, individuals and their motivations take-on greater importance in determining institutional and programmatic outcomes. Nevertheless, efforts to build data collection capacity in low-resource settings largely focus on supply-side interventions: the provision of infrastructure, equipment, and training sessions. Our results indicate that these interventions will continue to have limited long-term impacts and sustainability without complementary strategies for motivating or incentivizing water supply and surveillance agency managers to achieve testing goals. More broadly, our research demonstrates both an experimental approach for diagnosing the systems that underlie service provision and an analytical strategy for identifying appropriate interventions. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

  5. Design and validation of an intelligent wheelchair towards a clinically-functional outcome.

    PubMed

    Boucher, Patrice; Atrash, Amin; Kelouwani, Sousso; Honoré, Wormser; Nguyen, Hai; Villemure, Julien; Routhier, François; Cohen, Paul; Demers, Louise; Forget, Robert; Pineau, Joelle

    2013-06-17

    Many people with mobility impairments, who require the use of powered wheelchairs, have difficulty completing basic maneuvering tasks during their activities of daily living (ADL). In order to provide assistance to this population, robotic and intelligent system technologies have been used to design an intelligent powered wheelchair (IPW). This paper provides a comprehensive overview of the design and validation of the IPW. The main contributions of this work are three-fold. First, we present a software architecture for robot navigation and control in constrained spaces. Second, we describe a decision-theoretic approach for achieving robust speech-based control of the intelligent wheelchair. Third, we present an evaluation protocol motivated by a meaningful clinical outcome, in the form of the Robotic Wheelchair Skills Test (RWST). This allows us to perform a thorough characterization of the performance and safety of the system, involving 17 test subjects (8 non-PW users, 9 regular PW users), 32 complete RWST sessions, 25 total hours of testing, and 9 kilometers of total running distance. User tests with the RWST show that the navigation architecture reduced collisions by more than 60% compared to other recent intelligent wheelchair platforms. On the tasks of the RWST, we measured an average decrease of 4% in performance score and 3% in safety score (not statistically significant), compared to the scores obtained with conventional driving model. This analysis was performed with regular users that had over 6 years of wheelchair driving experience, compared to approximately one half-hour of training with the autonomous mode. The platform tested in these experiments is among the most experimentally validated robotic wheelchairs in realistic contexts. The results establish that proficient powered wheelchair users can achieve the same level of performance with the intelligent command mode, as with the conventional command mode.

  6. Identifying the performance characteristics of a winning outcome in elite mixed martial arts competition.

    PubMed

    James, Lachlan P; Robertson, Sam; Haff, G Gregory; Beckman, Emma M; Kelly, Vincent G

    2017-03-01

    To determine those performance indicators that have the greatest influence on classifying outcome at the elite level of mixed martial arts (MMA). A secondary objective was to establish the efficacy of decision tree analysis in explaining the characteristics of victory when compared to alternate statistical methods. Cross-sectional observational. Eleven raw performance indicators from male Ultimate Fighting Championship bouts (n=234) from July 2014 to December 2014 were screened for analysis. Each raw performance indicator was also converted to a rate-dependent measure to be scaled to fight duration. Further, three additional performance indicators were calculated from the dataset and included in the analysis. Cohen's d effect sizes were employed to determine the magnitude of the differences between Wins and Losses, while decision tree (chi-square automatic interaction detector (CHAID)) and discriminant function analyses (DFA) were used to classify outcome (Win and Loss). Effect size comparisons revealed differences between Wins and Losses across a number of performance indicators. Decision tree (raw: 71.8%; rate-scaled: 76.3%) and DFA (raw: 71.4%; rate-scaled 71.2%) achieved similar classification accuracies. Grappling and accuracy performance indicators were the most influential in explaining outcome. The decision tree models also revealed multiple combinations of performance indicators leading to victory. The decision tree analyses suggest that grappling activity and technique accuracy are of particular importance in achieving victory in elite-level MMA competition. The DFA results supported the importance of these performance indicators. Decision tree induction represents an intuitive and slightly more accurate approach to explaining bout outcome in this sport when compared to DFA. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. The role of environmental and individual characteristics in the development of student achievement: a comparison between a traditional and a problem-based-learning curriculum.

    PubMed

    Schauber, Stefan K; Hecht, Martin; Nouns, Zineb M; Kuhlmey, Adelheid; Dettmer, Susanne

    2015-10-01

    In medical education, the effect of the educational environment on student achievement has primarily been investigated in comparisons between traditional and problem-based learning (PBL) curricula. As many of these studies have reached no clear conclusions on the superiority of the PBL approach, the effect of curricular reform on student performance remains an issue. We employed a theoretical framework that integrates antecedents of student achievement from various psychosocial domains to examine how students interact with their curricular environment. In a longitudinal study with N = 1,646 participants, we assessed students in a traditional and a PBL-centered curriculum. The measures administered included students' perception of the learning environment, self-efficacy beliefs, positive study-related affect, social support, indicators of self-regulated learning, and academic achievement assessed through progress tests. We compared the relations between these characteristics in the two curricular environments. The results are two-fold. First, substantial relations of various psychosocial domains and their associations with achievement were identified. Second, our analyses indicated that there are no substantial differences between traditional and PBL-based curricula concerning the relational structure of psychosocial variables and achievement. Drawing definite conclusions on the role of curricular-level interventions in the development of student's academic achievement is constrained by the quasi-experimental design as wells as the selection of variables included. However, in the specific context described here, our results may still support the view of student activity as the key ingredient in the acquisition of achievement and performance.

  8. HRV based health&sport markers using video from the face.

    PubMed

    Capdevila, Lluis; Moreno, Jordi; Movellan, Javier; Parrado, Eva; Ramos-Castro, Juan

    2012-01-01

    Heart Rate Variability (HRV) is an indicator of health status in the general population and of adaptation to stress in athletes. In this paper we compare the performance of two systems to measure HRV: (1) A commercial system based on recording the physiological cardiac signal with (2) A computer vision system that uses a standard video images of the face to estimate RR from changes in skin color of the face. We show that the computer vision system performs surprisingly well. It estimates individual RR intervals in a non-invasive manner and with error levels comparable to those achieved by the physiological based system.

  9. The Performance Cycle: The Association between Student Achievement and State Policies Tying Together Teacher Performance, Student Achievement, and Accountability

    ERIC Educational Resources Information Center

    Alexander, Nicola A.; Jang, Sung Tae; Kankane, Shipi

    2017-01-01

    This article explores the associations between student performance and the presence of state policies that include student achievement in teacher evaluations. We examined performance among states from 2007 through 2013. Including student performance in state teacher evaluation policies is modestly associated with higher reading achievement but had…

  10. Quantitative analysis of the anti-noise performance of an m-sequence in an electromagnetic method

    NASA Astrophysics Data System (ADS)

    Yuan, Zhe; Zhang, Yiming; Zheng, Qijia

    2018-02-01

    An electromagnetic method with a transmitted waveform coded by an m-sequence achieved better anti-noise performance compared to the conventional manner with a square-wave. The anti-noise performance of the m-sequence varied with multiple coding parameters; hence, a quantitative analysis of the anti-noise performance for m-sequences with different coding parameters was required to optimize them. This paper proposes the concept of an identification system, with the identified Earth impulse response obtained by measuring the system output with the input of the voltage response. A quantitative analysis of the anti-noise performance of the m-sequence was achieved by analyzing the amplitude-frequency response of the corresponding identification system. The effects of the coding parameters on the anti-noise performance are summarized by numerical simulation, and their optimization is further discussed in our conclusions; the validity of the conclusions is further verified by field experiment. The quantitative analysis method proposed in this paper provides a new insight into the anti-noise mechanism of the m-sequence, and could be used to evaluate the anti-noise performance of artificial sources in other time-domain exploration methods, such as the seismic method.

  11. A Neuro-Fuzzy Approach in the Classification of Students' Academic Performance

    PubMed Central

    2013-01-01

    Classifying the student academic performance with high accuracy facilitates admission decisions and enhances educational services at educational institutions. The purpose of this paper is to present a neuro-fuzzy approach for classifying students into different groups. The neuro-fuzzy classifier used previous exam results and other related factors as input variables and labeled students based on their expected academic performance. The results showed that the proposed approach achieved a high accuracy. The results were also compared with those obtained from other well-known classification approaches, including support vector machine, Naive Bayes, neural network, and decision tree approaches. The comparative analysis indicated that the neuro-fuzzy approach performed better than the others. It is expected that this work may be used to support student admission procedures and to strengthen the services of educational institutions. PMID:24302928

  12. A neuro-fuzzy approach in the classification of students' academic performance.

    PubMed

    Do, Quang Hung; Chen, Jeng-Fung

    2013-01-01

    Classifying the student academic performance with high accuracy facilitates admission decisions and enhances educational services at educational institutions. The purpose of this paper is to present a neuro-fuzzy approach for classifying students into different groups. The neuro-fuzzy classifier used previous exam results and other related factors as input variables and labeled students based on their expected academic performance. The results showed that the proposed approach achieved a high accuracy. The results were also compared with those obtained from other well-known classification approaches, including support vector machine, Naive Bayes, neural network, and decision tree approaches. The comparative analysis indicated that the neuro-fuzzy approach performed better than the others. It is expected that this work may be used to support student admission procedures and to strengthen the services of educational institutions.

  13. Results achieved by emergency physicians in teaching basic cardiopulmonary resuscitation to secondary school students.

    PubMed

    Jiménez-Fábrega, Xavier; Escalada-Roig, Xavier; Sánchez, Miquel; Culla, Alexandre; Díaz, Núria; Gómez, Xavier; Villena, Olga; Rodríguez, Esther; Gaspar, Alberto; Molina, José Emilio; Salvador, Jordi; Miró, Oscar

    2009-06-01

    We investigated the results obtained with a basic cardiopulmonary resuscitation (b-CPR) program (PROCES) specifically designed for secondary school students (14-16 years old) and taught by emergency physicians. We used a multiple-choice test with 20 questions (10 on theory and 10 on skills) answered before and immediately after and 1 year after receiving the b-CPR course. Satisfactory learning was considered when at least 8 out of 10 skill questions were correctly answered. We investigated student variables associated with better immediate and deferred (1 year after) PROCES performance. We compared the results with those obtained using a more standardized program to teach b-CPR to police cadets. We enrolled 600 high school students. PROCES achieved significant improvement in overall, theory and skill marks immediately after the course (P<0.001), with a significant decay in all of them 1 year after the course (P<0.001). Satisfactory learning was achieved by 57% of school students immediately after PROCES and by 37% when assessed 1 year later. Students without pending study subjects (P=0.001) and those from private schools (P<0.01) achieved significantly better performance immediately after PROCES and only female students achieved greater performance 1 year after the course (P<0.05). With respect to police cadets instructed through a standardized course, immediate satisfactory learning of school students was lower (79 vs. 57%, respectively; P<0.001), whereas deferred satisfactory learning was higher (23 vs. 37%, respectively; P<0.05). Emergency physicians can satisfactorily instruct secondary school students in b-CPR using PROCES, and this specific program achieves a reasonable amount of satisfactory learning.

  14. Developing a hybrid dictionary-based bio-entity recognition technique.

    PubMed

    Song, Min; Yu, Hwanjo; Han, Wook-Shin

    2015-01-01

    Bio-entity extraction is a pivotal component for information extraction from biomedical literature. The dictionary-based bio-entity extraction is the first generation of Named Entity Recognition (NER) techniques. This paper presents a hybrid dictionary-based bio-entity extraction technique. The approach expands the bio-entity dictionary by combining different data sources and improves the recall rate through the shortest path edit distance algorithm. In addition, the proposed technique adopts text mining techniques in the merging stage of similar entities such as Part of Speech (POS) expansion, stemming, and the exploitation of the contextual cues to further improve the performance. The experimental results show that the proposed technique achieves the best or at least equivalent performance among compared techniques, GENIA, MESH, UMLS, and combinations of these three resources in F-measure. The results imply that the performance of dictionary-based extraction techniques is largely influenced by information resources used to build the dictionary. In addition, the edit distance algorithm shows steady performance with three different dictionaries in precision whereas the context-only technique achieves a high-end performance with three difference dictionaries in recall.

  15. Developing a hybrid dictionary-based bio-entity recognition technique

    PubMed Central

    2015-01-01

    Background Bio-entity extraction is a pivotal component for information extraction from biomedical literature. The dictionary-based bio-entity extraction is the first generation of Named Entity Recognition (NER) techniques. Methods This paper presents a hybrid dictionary-based bio-entity extraction technique. The approach expands the bio-entity dictionary by combining different data sources and improves the recall rate through the shortest path edit distance algorithm. In addition, the proposed technique adopts text mining techniques in the merging stage of similar entities such as Part of Speech (POS) expansion, stemming, and the exploitation of the contextual cues to further improve the performance. Results The experimental results show that the proposed technique achieves the best or at least equivalent performance among compared techniques, GENIA, MESH, UMLS, and combinations of these three resources in F-measure. Conclusions The results imply that the performance of dictionary-based extraction techniques is largely influenced by information resources used to build the dictionary. In addition, the edit distance algorithm shows steady performance with three different dictionaries in precision whereas the context-only technique achieves a high-end performance with three difference dictionaries in recall. PMID:26043907

  16. Five-way smoking status classification using text hot-spot identification and error-correcting output codes.

    PubMed

    Cohen, Aaron M

    2008-01-01

    We participated in the i2b2 smoking status classification challenge task. The purpose of this task was to evaluate the ability of systems to automatically identify patient smoking status from discharge summaries. Our submission included several techniques that we compared and studied, including hot-spot identification, zero-vector filtering, inverse class frequency weighting, error-correcting output codes, and post-processing rules. We evaluated our approaches using the same methods as the i2b2 task organizers, using micro- and macro-averaged F1 as the primary performance metric. Our best performing system achieved a micro-F1 of 0.9000 on the test collection, equivalent to the best performing system submitted to the i2b2 challenge. Hot-spot identification, zero-vector filtering, classifier weighting, and error correcting output coding contributed additively to increased performance, with hot-spot identification having by far the largest positive effect. High performance on automatic identification of patient smoking status from discharge summaries is achievable with the efficient and straightforward machine learning techniques studied here.

  17. Comparison of Pharmaceutical Calculations Learning Outcomes Achieved Within a Traditional Lecture or Flipped Classroom Andragogy.

    PubMed

    Anderson, H Glenn; Frazier, Lisa; Anderson, Stephanie L; Stanton, Robert; Gillette, Chris; Broedel-Zaugg, Kim; Yingling, Kevin

    2017-05-01

    Objective. To compare learning outcomes achieved from a pharmaceutical calculations course taught in a traditional lecture (lecture model) and a flipped classroom (flipped model). Methods. Students were randomly assigned to the lecture model and the flipped model. Course instructors, content, assessments, and instructional time for both models were equivalent. Overall group performance and pass rates on a standardized assessment (Pcalc OSCE) were compared at six weeks and at six months post-course completion. Results. Student mean exam scores in the flipped model were higher than those in the lecture model at six weeks and six months later. Significantly more students passed the OSCE the first time in the flipped model at six weeks; however, this effect was not maintained at six months. Conclusion. Within a 6 week course of study, use of a flipped classroom improves student pharmacy calculation skill achievement relative to a traditional lecture andragogy. Further study is needed to determine if the effect is maintained over time.

  18. Comparison of Pharmaceutical Calculations Learning Outcomes Achieved Within a Traditional Lecture or Flipped Classroom Andragogy

    PubMed Central

    Frazier, Lisa; Anderson, Stephanie L.; Stanton, Robert; Gillette, Chris; Broedel-Zaugg, Kim; Yingling, Kevin

    2017-01-01

    Objective. To compare learning outcomes achieved from a pharmaceutical calculations course taught in a traditional lecture (lecture model) and a flipped classroom (flipped model). Methods. Students were randomly assigned to the lecture model and the flipped model. Course instructors, content, assessments, and instructional time for both models were equivalent. Overall group performance and pass rates on a standardized assessment (Pcalc OSCE) were compared at six weeks and at six months post-course completion. Results. Student mean exam scores in the flipped model were higher than those in the lecture model at six weeks and six months later. Significantly more students passed the OSCE the first time in the flipped model at six weeks; however, this effect was not maintained at six months. Conclusion. Within a 6 week course of study, use of a flipped classroom improves student pharmacy calculation skill achievement relative to a traditional lecture andragogy. Further study is needed to determine if the effect is maintained over time. PMID:28630511

  19. Environmental performances of coproducts. Application of Claiming-Based Allocation models to straw and vetiver biorefineries in an Indian context.

    PubMed

    Gnansounou, Edgard; Raman, Jegannathan Kenthorai

    2018-04-24

    Among the renewables, non-food and wastelands based biofuels are essential for the transport sector to achieve country's climate mitigation targets. With the growing interest in biorefineries, setting policy requirements for other coproducts along with biofuels is necessary to improve the products portfolio of biorefinery, increase the bioproducts perception by the consumers and push the technology forward. Towards this context, Claiming-Based allocation models were used in comparative life cycle assessment of multiple products from wheat straw biorefinery and vetiver biorefinery. Vetiver biorefinery shows promising Greenhouse gas emission savings (181-213%) compared to the common crop based lignocellulose (wheat straw) biorefinery. Assistance of Claiming-Based Allocation models favors to find out the affordable allocation limit (0-80%) among the coproducts in order to achieve the individual prospective policy targets. Such models show promising application in multiproduct life cycle assessment studies where appropriate allocation is challenging to achieve the individual products emission subject to policy targets. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Multiclass Classification by Adaptive Network of Dendritic Neurons with Binary Synapses Using Structural Plasticity

    PubMed Central

    Hussain, Shaista; Basu, Arindam

    2016-01-01

    The development of power-efficient neuromorphic devices presents the challenge of designing spike pattern classification algorithms which can be implemented on low-precision hardware and can also achieve state-of-the-art performance. In our pursuit of meeting this challenge, we present a pattern classification model which uses a sparse connection matrix and exploits the mechanism of nonlinear dendritic processing to achieve high classification accuracy. A rate-based structural learning rule for multiclass classification is proposed which modifies a connectivity matrix of binary synaptic connections by choosing the best “k” out of “d” inputs to make connections on every dendritic branch (k < < d). Because learning only modifies connectivity, the model is well suited for implementation in neuromorphic systems using address-event representation (AER). We develop an ensemble method which combines several dendritic classifiers to achieve enhanced generalization over individual classifiers. We have two major findings: (1) Our results demonstrate that an ensemble created with classifiers comprising moderate number of dendrites performs better than both ensembles of perceptrons and of complex dendritic trees. (2) In order to determine the moderate number of dendrites required for a specific classification problem, a two-step solution is proposed. First, an adaptive approach is proposed which scales the relative size of the dendritic trees of neurons for each class. It works by progressively adding dendrites with fixed number of synapses to the network, thereby allocating synaptic resources as per the complexity of the given problem. As a second step, theoretical capacity calculations are used to convert each neuronal dendritic tree to its optimal topology where dendrites of each class are assigned different number of synapses. The performance of the model is evaluated on classification of handwritten digits from the benchmark MNIST dataset and compared with other spike classifiers. We show that our system can achieve classification accuracy within 1 − 2% of other reported spike-based classifiers while using much less synaptic resources (only 7%) compared to that used by other methods. Further, an ensemble classifier created with adaptively learned sizes can attain accuracy of 96.4% which is at par with the best reported performance of spike-based classifiers. Moreover, the proposed method achieves this by using about 20% of the synapses used by other spike algorithms. We also present results of applying our algorithm to classify the MNIST-DVS dataset collected from a real spike-based image sensor and show results comparable to the best reported ones (88.1% accuracy). For VLSI implementations, we show that the reduced synaptic memory can save upto 4X area compared to conventional crossbar topologies. Finally, we also present a biologically realistic spike-based version for calculating the correlations required by the structural learning rule and demonstrate the correspondence between the rate-based and spike-based methods of learning. PMID:27065782

  1. Drag Reduction and Performance Improvement of Hydraulic Torque Converters with Multiple Biological Characteristics.

    PubMed

    Chunbao, Liu; Li, Li; Yulong, Lei; Changsuo, Liu; Yubo, Zhang

    2016-01-01

    Fish-like, dolphin-like, and bionic nonsmooth surfaces were employed in a hydraulic torque converter to achieve drag reduction and performance improvement, which were aimed at reducing profile loss, impacting loss and friction loss, respectively. YJSW335, a twin turbine torque converter, was bionically designed delicately. The biological characteristics consisted of fish-like blades in all four wheels, dolphin-like structure in the first turbine and the stator, and nonsmooth surfaces in the pump. The prediction performance of bionic YJSW335, obtained by computational fluid dynamics simulation, was improved compared with that of the original model, and then it could be proved that drag reduction had been achieved. The mechanism accounting for drag reduction of three factors was also investigated. After bionic design, the torque ratio and the highest efficiencies of YJSW335 were both advanced, which were very difficult to achieve through traditional design method. Moreover, the highest efficiency of the low speed area and high speed area is 85.65% and 86.32%, respectively. By economic matching analysis of the original and bionic powertrains, the latter can significantly reduce the fuel consumption and improve the operating economy of the loader.

  2. Drag Reduction and Performance Improvement of Hydraulic Torque Converters with Multiple Biological Characteristics

    PubMed Central

    Chunbao, Liu; Changsuo, Liu; Yubo, Zhang

    2016-01-01

    Fish-like, dolphin-like, and bionic nonsmooth surfaces were employed in a hydraulic torque converter to achieve drag reduction and performance improvement, which were aimed at reducing profile loss, impacting loss and friction loss, respectively. YJSW335, a twin turbine torque converter, was bionically designed delicately. The biological characteristics consisted of fish-like blades in all four wheels, dolphin-like structure in the first turbine and the stator, and nonsmooth surfaces in the pump. The prediction performance of bionic YJSW335, obtained by computational fluid dynamics simulation, was improved compared with that of the original model, and then it could be proved that drag reduction had been achieved. The mechanism accounting for drag reduction of three factors was also investigated. After bionic design, the torque ratio and the highest efficiencies of YJSW335 were both advanced, which were very difficult to achieve through traditional design method. Moreover, the highest efficiency of the low speed area and high speed area is 85.65% and 86.32%, respectively. By economic matching analysis of the original and bionic powertrains, the latter can significantly reduce the fuel consumption and improve the operating economy of the loader. PMID:27752220

  3. Plant Species Identification by Bi-channel Deep Convolutional Networks

    NASA Astrophysics Data System (ADS)

    He, Guiqing; Xia, Zhaoqiang; Zhang, Qiqi; Zhang, Haixi; Fan, Jianping

    2018-04-01

    Plant species identification achieves much attention recently as it has potential application in the environmental protection and human life. Although deep learning techniques can be directly applied for plant species identification, it still needs to be designed for this specific task to obtain the state-of-art performance. In this paper, a bi-channel deep learning framework is developed for identifying plant species. In the framework, two different sub-networks are fine-tuned over their pretrained models respectively. And then a stacking layer is used to fuse the output of two different sub-networks. We construct a plant dataset of Orchidaceae family for algorithm evaluation. Our experimental results have demonstrated that our bi-channel deep network can achieve very competitive performance on accuracy rates compared to the existing deep learning algorithm.

  4. Comparison of reading and listening-reading techniques for administration of PIAT Reading Comprehension subtest: justification for the bypass approach.

    PubMed

    Weinberg, W A; McLean, A; Brumback, R A

    1988-04-01

    The Peabody Individual Achievement Test (PIAT) Reading Comprehension subtest was administered to a group of 23 learning disabled children in Grades 5 through 7 who had been classified by the clinical Lexical Paradigm as good readers or poor readers. Using standardized test administration, 14 poor readers scored substantially below the 9 good readers; however, when the child was allowed to listen and read silently while the test item was read aloud, poor readers showed marked improvement in performance compared to only moderate improvement shown by the good readers. This difference in improvement between the groups was significant and resulted in poor readers achieving performance similar to that of the good readers administered the test in the standard manner.

  5. A study of the tolerance block approach to special stratification. [winter wheat in Kansas

    NASA Technical Reports Server (NTRS)

    Richardson, W. (Principal Investigator)

    1979-01-01

    The author has identified the following significant results. Twelve winter wheat LACIE segments in Kansas were used to compare the performance of three clustering methods: (1) BCLUST, which uses a spectral distance function to accumulate clusters; (2) blocks-alone, which divides spectral space into equally populated blocks; and (3) block-seeds, which uses spectral means of blocks-alone as seeds for accumulating distance-type clusters. Both BCLUST and block-seeds performed equally well and outperformed blocks-alone significantly. Their average variance ratio of about 0.5 showed imperfect separation of wheat from non-wheat. This result points to the need to explore the achievable crop separability in the spectral/temporal domain, and suggest evaluating derived features rather than data channels as a means to achieve purer spectral strata.

  6. Family Matters: Promoting the Academic Adaptation of Latino Youth in New and Established Destination.

    PubMed

    Spees, Lisa; Perreira, Krista M; Fuligni, Andrew

    2017-03-01

    As primary agents of socialization, families and schools can powerfully shape the academic adaptation of youth. Using data from the SIAA studies, we compare the family and school environments of Latino high school seniors living in a new destination, North Carolina, with those living in an established destination, Los Angeles. We then evaluate how family and school environments influence their educational aspirations, expectations, and performance. We find that parents' achievement expectations promote Latino youths' academic success while perceived future family obligations inhibit them. Additionally, we find that schools remain essential in promoting Latino immigrant youths' achievement by providing a supportive and safe learning environment. Discrimination in schools and the broader community is associated with lower educational expectations and aspirations but not lower academic performance.

  7. A meta-analysis of self-reported achievement goals and nonself-report performance across three achievement domains (work, sports, and education).

    PubMed

    Van Yperen, Nico W; Blaga, Monica; Postmes, Tom

    2014-01-01

    During the past three decades, the achievement goal approach to achievement motivation has emerged as an influential area of research, and is dedicated to understanding the reasons behind the individual's drive to achieve competence and performance. However, the current literature on achievement goals is segmented rather than integrated. That is, citations across the three major and distinct achievement domains (work, education, and sports) are more the exception than the rule and similarities and differences between findings for the different achievement domains have yet to be tested. The purpose of the present study was to examine the relationships between self-reported achievement goals and nonself-report performance through meta-analysis, and the moderating potential of achievement domain. Identifying achievement domain as moderator improves our understanding to which contexts we can (not) generalize conclusions to, it helps to understand seemingly inconsistent findings, and opens avenues for future research on the underlying processes. Because the achievement goal (AG) measure used in a study is partially confounded with achievement domain, we examined the moderating role of this variable as well. Our findings suggest that - overall - approach goals (either mastery or performance) were associated positively with performance attainment, whereas avoidance goals (either mastery or performance) were associated negatively with performance attainment. These relationships were moderated by achievement domain. For example, relative to the education or work domain, in the sports domain, we did not observe negative correlations between avoidance goals and performance. The absence of statistical moderation due to AG measure suggests that the observed moderation of achievement domain cannot be explained by the AG measure utilized. We suggest further steps to integrate the achievement goal literature, and accordingly, to broaden and deepen understanding of performance attainment in competence-relevant settings, including the workplace, the sports field, and the classroom.

  8. A Meta-Analysis of Self-Reported Achievement Goals and Nonself-Report Performance across Three Achievement Domains (Work, Sports, and Education)

    PubMed Central

    Van Yperen, Nico W.; Blaga, Monica; Postmes, Tom

    2014-01-01

    During the past three decades, the achievement goal approach to achievement motivation has emerged as an influential area of research, and is dedicated to understanding the reasons behind the individual’s drive to achieve competence and performance. However, the current literature on achievement goals is segmented rather than integrated. That is, citations across the three major and distinct achievement domains (work, education, and sports) are more the exception than the rule and similarities and differences between findings for the different achievement domains have yet to be tested. The purpose of the present study was to examine the relationships between self-reported achievement goals and nonself-report performance through meta-analysis, and the moderating potential of achievement domain. Identifying achievement domain as moderator improves our understanding to which contexts we can (not) generalize conclusions to, it helps to understand seemingly inconsistent findings, and opens avenues for future research on the underlying processes. Because the achievement goal (AG) measure used in a study is partially confounded with achievement domain, we examined the moderating role of this variable as well. Our findings suggest that – overall – approach goals (either mastery or performance) were associated positively with performance attainment, whereas avoidance goals (either mastery or performance) were associated negatively with performance attainment. These relationships were moderated by achievement domain. For example, relative to the education or work domain, in the sports domain, we did not observe negative correlations between avoidance goals and performance. The absence of statistical moderation due to AG measure suggests that the observed moderation of achievement domain cannot be explained by the AG measure utilized. We suggest further steps to integrate the achievement goal literature, and accordingly, to broaden and deepen understanding of performance attainment in competence-relevant settings, including the workplace, the sports field, and the classroom. PMID:24699695

  9. Are general practitioners characteristics associated with the quality of type 2 diabetes care in general practice? Results from the Norwegian ROSA4 study from 2014.

    PubMed

    Tran, Anh Thi; Bakke, Åsne; Berg, Tore J; Gjelsvik, Bjørn; Mdala, Ibrahimu; Nøkleby, Kjersti; Shakil Rai, Anam; Cooper, John G; Claudi, Tor; Løvaas, Karianne; Thue, Geir; Sandberg, Sverre; Jenum, Anne K

    2018-06-01

    To explore the associations between general practitioners (GPs) characteristics such as gender, specialist status, country of birth and country of graduation and the quality of care for patients with type 2 diabetes (T2DM). Cross-sectional survey. The 277 GPs provided care for 10082 patients with T2DM in Norway in 2014. The GPs characteristics were self-reported: 55% were male, 68% were specialists in General Practice, 82% born in Norway and 87% had graduated in Western Europe. Of patients, 81% were born in Norway and 8% in South Asia. Data regarding diabetes care were obtained from electronic medical records and manually verified. Performance of recommended screening procedures, prescribed medication and level of HbA1c, blood pressure and LDL-cholesterol stratified according to GPs characteristics, adjusted for patient and GP characteristics. Female GPs, specialists, GPs born in Norway and GPs who graduated in Western Europe performed recommended procedures more frequently than their counterparts. Specialists achieved lower mean HbA1c (7.14% vs. 7.25%, p < 0.01), a larger proportion of their patients achieved good glycaemic control (HbA1c = 6.0%-7.0%) (49.1% vs. 44.4%, p = 0.018) and lower mean systolic blood pressure (133.0 mmHg vs. 134.7 mmHg, p < 0.01) compared with non-specialists. GPs who graduated in Western Europe achieved lower diastolic blood pressure than their counterparts (76.6 mmHg vs. 77.8 mmHg, p < 0.01). Several quality indicators for type 2 diabetes care were better if the GPs were specialists in General Practice. Key Points Research on associations between General Practitioners (GPs) characteristics and quality of care for patients with type 2 diabetes is limited. Specialists in General Practice performed recommended procedures more frequently, achieved better HbA1c and blood pressure levels than non-specialists. GPs who graduated in Western Europe performed screening procedures more frequently and achieved lower diastolic blood pressure compared with their counterparts. There were few significant differences in the quality of care between GP groups according to their gender and country of birth.

  10. A comparison of rural high school students in Germany with rural Tennessee high school students' mathematics and science achievement

    NASA Astrophysics Data System (ADS)

    Harding, R. Fredrick

    This descriptive study compared the science and mathematics aptitudes and achievement test scores for the final school year students in rural White County and Van Buren County, Tennessee with rural county students in Germany. In accordance with the previous research literature (Stevenson, 2002), German students outperformed U.S. students on The International Trends in Math and Science test (TIMSS). As reform in the U.S. education system has been underway, this study intended to compare German county student final school year performance with White County and Van Buren County (Grade 12) performance in science and mathematics. The entire populations of 176 White and Van Buren Counties senior high final school year students were compared with 120 school final year students from two rural German county high schools. The student responses to identical test and questionnaire items were compared using the t-test statistical analysis. In conclusion after t-test analyses, there was no significant difference (p>.05 level) in student attitudes on the 27 problem achievement and the 35 TIMSS questionnaire items between the sampled population of 120 German students compared with the population of 176 White and Van Buren students. Also, there was no statistically significant difference (p>.05 level) between the German, White, and Van Buren County rural science and math achievement in the TIMSS problem section of the final year test. Based on the research, recommendations to improve U.S. student scores to number one in the world include making changes in teaching methodology in mathematics and science; incorporating pamphlet lessons rather than heavily reliance on textbooks; focusing on problem solving; establishing an online clearinghouse for effective lessons; creating national standards in mathematics and science; matching students' course choices to job aspirations; tracking misbehaving students rather than mainstreaming them into the regular classroom; and designing individual educational plans for every student. Further study and future investigations are recommended from this study to compare White County and Van Buren County Students with other rural county schools in Tennessee, as well as other states. In addition, the Tennessee students' state mandated science and mathematics could be correlated to the TIMMS to identify trends and relationships. Future comparisons of White County and Van Buren County with higher scoring rural Asian students could be done in search of more effective methods of teaching science and mathematics.

  11. Achieving target refraction after cataract surgery.

    PubMed

    Simon, Shira S; Chee, Yewlin E; Haddadin, Ramez I; Veldman, Peter B; Borboli-Gerogiannis, Sheila; Brauner, Stacey C; Chang, Kenneth K; Chen, Sherleen H; Gardiner, Matthew F; Greenstein, Scott H; Kloek, Carolyn E; Chen, Teresa C

    2014-02-01

    To evaluate the difference between target and actual refraction after phacoemulsification and intraocular lens implantation at an academic teaching institution's Comprehensive Ophthalmology Service. Retrospective study. We examined 1275 eye surgeries for this study. All consecutive cataract surgeries were included if they were performed by an attending or resident surgeon from January through December 2010. Postoperative refractions were compared with preoperative target refractions. Patients were excluded if they did not have a preoperative target refraction documented or if they did not have a recorded postoperative manifest refraction within 90 days. The main outcome measure was percentage of cases achieving a postoperative spherical equivalent ± 1.0 diopter (D) of target spherical equivalent. We performed 1368 cataract surgeries from January through December of 2010. Of these, 1275 (93%) had sufficient information for analysis. Of the included cases, 94% (1196 of 1275) achieved ± 1.0 D of target refraction by 90 days after cataract surgery. This paper establishes a new benchmark for a teaching hospital, where 94% of patients achieved within 1.0 D of target refraction after cataract surgery. The refractive outcomes after cataract surgery at this academic teaching institution were higher than average international benchmarks. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  12. Customizing elastic pressure bandages for reuse to a predetermined, sub-bandage pressure: A randomized controlled trial.

    PubMed

    Sermsathanasawadi, Nuttawut; Tarapongpun, Tanakorn; Pianchareonsin, Rattana; Puangpunngam, Nattawut; Wongwanit, Chumpol; Chinsakchai, Khamin; Mutirangura, Pramook; Ruangsetakit, Chanean

    2017-01-01

    Objective A randomized clinical trial was performed to compare the effectiveness of unmarked bandages and customized bandages with visual markers in reproducing the desired sub-bandage pressure during self-bandaging by patients. Method Ninety patients were randomly allocated to two groups ("customized bandages" and "unmarked bandages") and asked to perform self-bandaging three times. The achievement of a pressure between 35 and 45 mmHg in at least two of the three attempts was defined as adequate quality. Results Adequate quality was achieved by 33.0% when applying the unmarked bandages, and 60.0% when applying the customized bandages ( p = 0.02). Use of the customized bandage and previous experience of bandaging were independent predictors for the achievement of the predetermined sub-bandage pressure ( p = 0.005 and p = 0.021, respectively). Conclusion Customized bandages may achieve predetermined sub-bandage pressures more closely than standard, unmarked, compression bandages. Clinical trials registration ClinicalTrials.gov (NCT02729688). Effectiveness of a Pressure Indicator Guided and a Conventional Bandaging in Treatment of Venous Leg Ulcer. https://clinicaltrials.gov/ct2/show/NCT02729688.

  13. Conical structures for highly efficient solar cell applications

    NASA Astrophysics Data System (ADS)

    Korany, Fatma M. H.; Hameed, Mohamed Farhat O.; Hussein, Mohamed; Mubarak, Roaa; Eladawy, Mohamed I.; Obayya, Salah Sabry A.

    2018-01-01

    Improving solar cell efficiency is a critical research topic. Nowadays, light trapping techniques are a promising way to enhance solar cell performance. A modified nanocone nanowire (NW) is proposed and analyzed for solar cell applications. The suggested NW consists of conical and truncated conical units. The geometrical parameters are studied using a three-dimensional (3-D) finite difference time-domain (FDTD) method to achieve broadband absorption through the reported design and maximize its ultimate efficiency. The analyzed parameters are absorption spectra, ultimate efficiency, and short circuit current density. The numerical results prove that the proposed structure is superior compared with cone, truncated cone, and cylindrical NWs. The reported design achieves an ultimate efficiency of 44.21% with substrate and back reflector. Further, short circuit current density of 36.17 mA / cm2 is achieved by the suggested NW. The electrical performance analysis of the proposed structure including doping concentration, junction thickness, and Shockley-Read-Hall recombination is also investigated. The electrical simulations show that a power conversion efficiency of 17.21% can be achieved using the proposed NW. The modified nanocone has advantages of broadband absorption enhancement, low cost, and fabrication feasibility.

  14. Consideration of learning orientations as an application of achievement goals in evaluating life science majors in introductory physics

    NASA Astrophysics Data System (ADS)

    Mason, Andrew J.; Bertram, Charles A.

    2018-06-01

    When considering performing an Introductory Physics for Life Sciences course transformation for one's own institution, life science majors' achievement goals are a necessary consideration to ensure the pedagogical transformation will be effective. However, achievement goals are rarely an explicit consideration in physics education research topics such as metacognition. We investigate a sample population of 218 students in a first-semester introductory algebra-based physics course, drawn from 14 laboratory sections within six semesters of course sections, to determine the influence of achievement goals on life science majors' attitudes towards physics. Learning orientations that, respectively, pertain to mastery goals and performance goals, in addition to a learning orientation that does not report a performance goal, were recorded from students in the specific context of learning a problem-solving framework during an in-class exercise. Students' learning orientations, defined within the context of students' self-reported statements in the specific context of a problem-solving-related research-based course implementation, are compared to pre-post results on physics problem-solving items in a well-established attitudinal survey instrument, in order to establish the categories' validity. In addition, mastery-related and performance-related orientations appear to extend to overall pre-post attitudinal shifts, but not to force and motion concepts or to overall course grade, within the scope of an introductory physics course. There also appears to be differentiation regarding overall course performance within health science majors, but not within biology majors, in terms of learning orientations; however, health science majors generally appear to fare less well on all measurements in the study than do biology majors, regardless of learning orientations.

  15. High performance ultrasonic field simulation on complex geometries

    NASA Astrophysics Data System (ADS)

    Chouh, H.; Rougeron, G.; Chatillon, S.; Iehl, J. C.; Farrugia, J. P.; Ostromoukhov, V.

    2016-02-01

    Ultrasonic field simulation is a key ingredient for the design of new testing methods as well as a crucial step for NDT inspection simulation. As presented in a previous paper [1], CEA-LIST has worked on the acceleration of these simulations focusing on simple geometries (planar interfaces, isotropic materials). In this context, significant accelerations were achieved on multicore processors and GPUs (Graphics Processing Units), bringing the execution time of realistic computations in the 0.1 s range. In this paper, we present recent works that aim at similar performances on a wider range of configurations. We adapted the physical model used by the CIVA platform to design and implement a new algorithm providing a fast ultrasonic field simulation that yields nearly interactive results for complex cases. The improvements over the CIVA pencil-tracing method include adaptive strategies for pencil subdivisions to achieve a good refinement of the sensor geometry while keeping a reasonable number of ray-tracing operations. Also, interpolation of the times of flight was used to avoid time consuming computations in the impulse response reconstruction stage. To achieve the best performance, our algorithm runs on multi-core superscalar CPUs and uses high performance specialized libraries such as Intel Embree for ray-tracing, Intel MKL for signal processing and Intel TBB for parallelization. We validated the simulation results by comparing them to the ones produced by CIVA on identical test configurations including mono-element and multiple-element transducers, homogeneous, meshed 3D CAD specimens, isotropic and anisotropic materials and wave paths that can involve several interactions with interfaces. We show performance results on complete simulations that achieve computation times in the 1s range.

  16. Lithium metal doped electrodes for lithium-ion rechargeable chemistry

    DOEpatents

    Liu, Gao; Battaglia, Vince; Wang, Lei

    2016-09-13

    An embodiment of the invention combines the superior performance of a polyvinylidene difluoride (PVDF) or polyethyleneoxide (POE) binder, the strong binding force of a styrene-butadiene (SBR) binder, and a source of lithium ions in the form of solid lithium metal powder (SLMP) to form an electrode system that has improved performance as compared to PVDF/SBR binder based electrodes. This invention will provide a new way to achieve improved results at a much reduced cost.

  17. Indiana's TIMSS 2011 Performance: Outperforming Much of the World in Math and Science, but Issues Remain for Gender Achievement and High Performers. Education Policy Brief. Volume 11, Number 1, Winter 2013

    ERIC Educational Resources Information Center

    Rutkowski, David; Wild, Justin; Rutkowski, Leslie

    2013-01-01

    Are U.S. and, in particular, Hoosier students competitive and ready to succeed in an ever-changing and increasingly global economic landscape? This question is frequently considered by K-12 education stakeholders at all levels, including national, state, and local officials. One of the central ways in which education systems can compare themselves…

  18. Investigation of different ethylenediamine-N,N'-disuccinic acid-enhanced washing configurations for remediation of a Cu-contaminated soil: process kinetics and efficiency comparison between single-stage and multi-stage configurations.

    PubMed

    Ferraro, Alberto; Fabbricino, Massimiliano; van Hullebusch, Eric D; Esposito, Giovanni

    2017-09-01

    A comparison of Cu extraction yields for three different ethylenediamine-N,N'-disuccinic acid (EDDS)-enhanced washing configurations was performed on a Cu-contaminated soil. Batch experiments were used to simulate a single-stage continuous stirred tank reactor (CSTR) and a multi-stage (side feeding and counter-current) reactor. Single-stage CSTR conditions were simulated for various EDDS:(Cu + Cd + Pb + Co + Ni + Zn) molar ratio (EDDS:M ratio) (from 1 to 30) and liquid to soil (L/S) ratio (from 15 to 45). The highest Cu extraction yield (≃56%) was achieved with EDDS:M = 30. In contrast, a Cu extraction yield decrease was observed with increasing L/S ratio with highest extracted Cu achievement (≃48%) for L/S = 15. Side feeding configuration was tested in four experimental conditions through different fractionation mode of EDDS dose and treatment time at each washing step. Results from the four tests showed all enhanced Cu extraction (maximum values from ≃43 to ≃51%) achieved at lower treatment time and lower EDDS:M molar ratio compared to CSTR configuration with L/S = 25 and EDDS:M = 10. The counter-current washing was carried out through two washing flows achieving a process performance enhancement with 27% increase of extracted Cu compared to single-stage CSTR configuration. Higher Cu extraction percentage (36.8%) was observed in the first washing phase than in the second one (24.7%).

  19. Hospital performance recognition with the Get With The Guidelines Program and mortality for acute myocardial infarction and heart failure.

    PubMed

    Heidenreich, Paul A; Lewis, William R; LaBresh, Kenneth A; Schwamm, Lee H; Fonarow, Gregg C

    2009-10-01

    Many hospitals enrolled in the American Heart Association's Get With The Guidelines (GWTG) Program achieve high levels of recommended care for heart failure, acute myocardial infarction (MI) and stroke. However, it is unclear if outcomes are better in those hospitals recognized by the GWTG program for their processes of care. We compared hospitals enrolled in GWTG and receiving achievement awards for high levels of recommended processes of care with other hospitals using data on risk-adjusted 30-day survival for heart failure and acute MI reported by the Center for Medicare and Medicaid Services. Among the 3,909 hospitals with 30-day data reported by Center for Medicare and Medicaid Services 355 (9%) received GWTG achievement awards. Risk-adjusted mortality for hospitals receiving awards was lower for both heart failure (11.0% vs 11.2%, P = .0005) and acute MI (16.1% vs 16.5%, P < .0001) compared to those not receiving awards. After additional adjustment for hospital characteristics and noncardiac performance measures, the reduction in mortality remained significantly lower for GWTG award hospitals for acute myocardial infraction (-0.19%, 95% CI -0.33 to -0.05), but not for heart failure (-0.11%, 95% CI -0.25 to 0.02). Additional adjustment for cardiac processes of care reduced the benefit of award hospitals by 28% for heart failure mortality and 43% for acute MI mortality. Hospitals receiving achievement awards from the GWTG program have modestly lower risk adjusted mortality for acute MI and to a lesser extent, heart failure, explained in part by better process of care.

  20. 802.11ac WLAN MIMO radio-over-fiber distributed antenna system for in-building networks based on multicore fiber

    NASA Astrophysics Data System (ADS)

    Morant, Maria; Llorente, Roberto

    2017-01-01

    In this work we propose and evaluate experimentally the performance of IEEE 802.11ac WLAN standard signals in radio-over-fiber (RoF) distributed-antenna systems based on multicore fiber (MCF) for in-building WLAN connectivity. The RoF performance of WLAN signals with different bandwidth is investigated considering up to IEEE 802.11ac maximum of 160 MHz per user. We evaluate experimentally the performance of WLAN signals employing different modulation and coding schemes achieving bitrates from 78 Mbps to 1404 Mbps per user in distances up to 300 m in a 4-core MCF. The performance of the wireless standard multiple-input multiple-output (MIMO) processing algorithms included in WLAN signals applied to the RoF transmission in MCF optical systems is also evaluated. The impact on the quality of the signal from one of the cores in the MIMO processing is investigated and compared with the results achieved with single-input single-output (SISO) transmission in each core. We measured the error vector magnitude (EVM) and the OFDM data burst information of the received WLAN signals after RoF transmission for different distributed-antenna systems with uni- and bi-directional MCF communication. Finally, we compare the received EVM of a single-antenna system (SISO arrangement) with WLAN systems using two antennas (2×2 MIMO) and four antennas (4×4 MIMO).

  1. Predictive validity of pre-admission assessments on medical student performance.

    PubMed

    Dabaliz, Al-Awwab; Kaadan, Samy; Dabbagh, M Marwan; Barakat, Abdulaziz; Shareef, Mohammad Abrar; Al-Tannir, Mohamad; Obeidat, Akef; Mohamed, Ayman

    2017-11-24

    To examine the predictive validity of pre-admission variables on students' performance in a medical school in Saudi Arabia. In this retrospective study, we collected admission and college performance data for 737 students in preclinical and clinical years. Data included high school scores and other standardized test scores, such as those of the National Achievement Test and the General Aptitude Test. Additionally, we included the scores of the Test of English as a Foreign Language (TOEFL) and the International English Language Testing System (IELTS) exams. Those datasets were then compared with college performance indicators, namely the cumulative Grade Point Average (cGPA) and progress test, using multivariate linear regression analysis. In preclinical years, both the National Achievement Test (p=0.04, B=0.08) and TOEFL (p=0.017, B=0.01) scores were positive predictors of cGPA, whereas the General Aptitude Test (p=0.048, B=-0.05) negatively predicted cGPA. Moreover, none of the pre-admission variables were predictive of progress test performance in the same group. On the other hand, none of the pre-admission variables were predictive of cGPA in clinical years. Overall, cGPA strongly predict-ed students' progress test performance (p<0.001 and B=19.02). Only the National Achievement Test and TOEFL significantly predicted performance in preclinical years. However, these variables do not predict progress test performance, meaning that they do not predict the functional knowledge reflected in the progress test. We report various strengths and deficiencies in the current medical college admission criteria, and call for employing more sensitive and valid ones that predict student performance and functional knowledge, especially in the clinical years.

  2. Predictive validity of pre-admission assessments on medical student performance

    PubMed Central

    Dabaliz, Al-Awwab; Kaadan, Samy; Dabbagh, M. Marwan; Barakat, Abdulaziz; Shareef, Mohammad Abrar; Al-Tannir, Mohamad; Obeidat, Akef

    2017-01-01

    Objectives To examine the predictive validity of pre-admission variables on students’ performance in a medical school in Saudi Arabia.  Methods In this retrospective study, we collected admission and college performance data for 737 students in preclinical and clinical years. Data included high school scores and other standardized test scores, such as those of the National Achievement Test and the General Aptitude Test. Additionally, we included the scores of the Test of English as a Foreign Language (TOEFL) and the International English Language Testing System (IELTS) exams. Those datasets were then compared with college performance indicators, namely the cumulative Grade Point Average (cGPA) and progress test, using multivariate linear regression analysis. Results In preclinical years, both the National Achievement Test (p=0.04, B=0.08) and TOEFL (p=0.017, B=0.01) scores were positive predictors of cGPA, whereas the General Aptitude Test (p=0.048, B=-0.05) negatively predicted cGPA. Moreover, none of the pre-admission variables were predictive of progress test performance in the same group. On the other hand, none of the pre-admission variables were predictive of cGPA in clinical years. Overall, cGPA strongly predict-ed students’ progress test performance (p<0.001 and B=19.02). Conclusions Only the National Achievement Test and TOEFL significantly predicted performance in preclinical years. However, these variables do not predict progress test performance, meaning that they do not predict the functional knowledge reflected in the progress test. We report various strengths and deficiencies in the current medical college admission criteria, and call for employing more sensitive and valid ones that predict student performance and functional knowledge, especially in the clinical years. PMID:29176032

  3. Characterization of a hypersonic quiet wind tunnel nozzle

    NASA Astrophysics Data System (ADS)

    Sweeney, Cameron J.

    The Boeing/AFOSR Mach-6 Quiet Tunnel at Purdue University has been able to achieve low-disturbance flows at high Reynolds numbers for approximately ten years. The flow in the nozzle was last characterized in 2010. However, researchers have noted that the performance of the nozzle has changed in the intervening years. Understand ing the tunnel characteristics is critical for the hypersonic boundary-layer transition research performed at the facility and any change in performance could have signif icant effects on research performed at the facility. Pitot probe measurements were made using Kulite and PCB pressure transducers to quantify the performance changes since characterization was last performed. Aspects of the nozzle that were investi gated include the radial uniformity of the flow, the effects that time and stagnation pressure have on the flow, and the Reynolds number limits of low-disturbance flows. Measurements showed that freestream noise levels are consistently around 0.01% to 0.02% for the majority of the quiet flow core, with quiet flow now achievable for Reynolds numbers up to Re = 13.0x10 6/m. Additionally, while pitot probes are a widely used measurement technique for quantifying freestream disturbances, pitot probes are not without drawbacks. In order to provide a more complete methodology for freestream noise measurement other researchers have started experimenting with alternate geometries, such as cones. Using a newly designed 30° half-angle cone model, measurements were performed to quantify the freestream noise in the BAM6QT and compare the performance with another hypersonic wind tunnel. Also, measurements were made with three newly designed pitot sleeves to study the effects of probe geometry on freestream noise measurements. The results were compared to recent DNS calculations.

  4. Reading instead of reasoning? Predictors of arithmetic skills in children with cochlear implants.

    PubMed

    Huber, Maria; Kipman, Ulrike; Pletzer, Belinda

    2014-07-01

    The aim of the present study was to evaluate whether the arithmetic achievement of children with cochlear implants (CI) was lower or comparable to that of their normal hearing peers and to identify predictors of arithmetic achievement in children with CI. In particular we related the arithmetic achievement of children with CI to nonverbal IQ, reading skills and hearing variables. 23 children with CI (onset of hearing loss in the first 24 months, cochlear implantation in the first 60 months of life, atleast 3 years of hearing experience with the first CI) and 23 normal hearing peers matched by age, gender, and social background participated in this case control study. All attended grades two to four in primary schools. To assess their arithmetic achievement, all children completed the "Arithmetic Operations" part of the "Heidelberger Rechentest" (HRT), a German arithmetic test. To assess reading skills and nonverbal intelligence as potential predictors of arithmetic achievement, all children completed the "Salzburger Lesetest" (SLS), a German reading screening, and the Culture Fair Intelligence Test (CFIT), a nonverbal intelligence test. Children with CI did not differ significantly from hearing children in their arithmetic achievement. Correlation and regression analyses revealed that in children with CI, arithmetic achievement was significantly (positively) related to reading skills, but not to nonverbal IQ. Reading skills and nonverbal IQ were not related to each other. In normal hearing children, arithmetic achievement was significantly (positively) related to nonverbal IQ, but not to reading skills. Reading skills and nonverbal IQ were positively correlated. Hearing variables were not related to arithmetic achievement. Children with CI do not show lower performance in non-verbal arithmetic tasks, compared to normal hearing peers. Copyright © 2014. Published by Elsevier Ireland Ltd.

  5. Global velocity constrained cloud motion prediction for short-term solar forecasting

    NASA Astrophysics Data System (ADS)

    Chen, Yanjun; Li, Wei; Zhang, Chongyang; Hu, Chuanping

    2016-09-01

    Cloud motion is the primary reason for short-term solar power output fluctuation. In this work, a new cloud motion estimation algorithm using a global velocity constraint is proposed. Compared to the most used Particle Image Velocity (PIV) algorithm, which assumes the homogeneity of motion vectors, the proposed method can capture the accurate motion vector for each cloud block, including both the motional tendency and morphological changes. Specifically, global velocity derived from PIV is first calculated, and then fine-grained cloud motion estimation can be achieved by global velocity based cloud block researching and multi-scale cloud block matching. Experimental results show that the proposed global velocity constrained cloud motion prediction achieves comparable performance to the existing PIV and filtered PIV algorithms, especially in a short prediction horizon.

  6. Insight into the Effects of Reinforcement Shape on Achieving Continuous Martensite Transformation in Phase Transforming Matrix Composites

    NASA Astrophysics Data System (ADS)

    Zhang, Xudong; Ren, Junqiang; Wang, Xiaofei; Zong, Hongxiang; Cui, Lishan; Ding, Xiangdong

    2017-12-01

    A continuous martensite transformation is indispensable for achieving large linear superelasticity and low modulus in phase transforming metal-based composites. However, determining how to accurately condition the residual martensite in a shape memory alloy matrix though the reinforcement shape to achieve continuous martensite transformation has been a challenge. Here, we take the finite element method to perform a comparative study of the effects of nanoinclusion shape on the interaction and martensite phase transformation in this new composite. Two typical samples are compared: one reinforced by metallic nanowires and the other by nanoparticles. We find that the residual martensite within the shape memory alloy matrix after a pretreatment can be tailored by the reinforcement shape. In particular, our results show that the shape memory alloy matrix can retain enough residual martensite phases to achieve continuous martensite transformation in the subsequent loading when the aspect ratio of nanoreinforcement is larger than 20. In contrast, the composites reinforced with spherical or low aspect ratio reinforcement show a typical nonlinear superelasticity as a result of a low stress transfer-induced discontinuous martensite transformation within the shape memory alloy matrix.

  7. Integrating Technology and Inquiry Pedagogy: Needs-Based Professional Development.

    ERIC Educational Resources Information Center

    Berber, Brian; Brovey, Andrew

    Valdosta State University (VSU), fulfills the academic needs of the South Georgia area. Student performance on the state mandated science assessment was well below achievement levels compared to other subject areas. VSU must reach out to science teachers in the area to improve teaching skills if their students are to become productive,…

  8. Bullying Behaviors and Self Efficacy among Nursing Students at Clinical Settings: Comparative Study

    ERIC Educational Resources Information Center

    Kassem, Awatef Hassan

    2015-01-01

    Background: Nursing students who experienced bullying behaviors feel anger and missing their concentration, their capability to achieve a desired outcome. Also self-efficacy, often referred to as self-confidence, is essential to nursing students' ability and performance in the clinical setting. Aim: Study aimed to examine relation between bullying…

  9. Effects of the Subliminal Stimulation of Symbiotic Fantasies on the Academic Performance of Emotionally Handicapped Students.

    ERIC Educational Resources Information Center

    Bryant-Tuckett, Rose; Silverman, Lloyd H.

    1984-01-01

    Compared emotionally disturbed adolescents (N=64) who were divided into experimental and control groups and exposed to a subliminal stimulus. Experimental subjects exposed to the phrase "Mommy and I are one" showed greater academic achievement and adaptive functioning at the end of the six-week treatment. (JAC)

  10. Paraphrasing and Prediction with Self-Explanation as Generative Strategies for Learning Science Principles in a Simulation

    ERIC Educational Resources Information Center

    Morrison, Jennifer R.; Bol, Linda; Ross, Steven M.; Watson, Ginger S.

    2015-01-01

    This study examined the incorporation of generative strategies for the guided discovery of physics principles in a simulation. Participants who either paraphrased or predicted and self-explained guided discovery assignments exhibited improved performance on an achievement test as compared to a control group. Calibration accuracy (the…

  11. The Impact of Video Game Playing on Academic Performance at a Community College.

    ERIC Educational Resources Information Center

    McCutcheon, Lynn E.; Campbell, Janice D.

    1986-01-01

    Studies the relationship between video game playing and academic achievement. Compares matched groups of community college psychology students, differing in the amount of their game playing. There were no differences between frequent and infrequent players on measures of psychology class attendance, locus of control, or grade point average.…

  12. ICT for Children of Immigrants: Indirect and Total Effects via Self-Efficacy on Math Performance

    ERIC Educational Resources Information Center

    Kim, Sunha

    2018-01-01

    This study compared the direct, indirect, and total effects of information, communication, and technology (ICT) variables on math achievement for second-generation immigrant, first-generation immigrant, and nonimmigrant students. A path model was used to analyze U.S. nationally representative data from the Program for International Student…

  13. Biomechanical and Psychological Analysis of High School, Intercollegiate, and Elite Long-Distance Runners

    ERIC Educational Resources Information Center

    Solorio, Claribel; Hickey, Ann

    2015-01-01

    It is undeniable that efficiency and mentality are crucial to achieving optimal athletic performance during competition. However, development of psychological skills is often neglected, particularly in lower levels of competition. The purpose of this study was to analyze and compare the biomechanical efficiency and psychological skills use among…

  14. JPL CMOS Active Pixel Sensor Technology

    NASA Technical Reports Server (NTRS)

    Fossum, E. R.

    1995-01-01

    This paper will present the JPL-developed complementary metal- oxide-semiconductor (CMOS) active pixel sensor (APS) technology. The CMOS APS has achieved performance comparable to charge coupled devices, yet features ultra low power operation, random access readout, on-chip timing and control, and on-chip analog to digital conversion. Previously published open literature will be reviewed.

  15. Using TIMSS and PISA Results to Inform Educational Policy: A Study of Russia and Its Neighbours

    ERIC Educational Resources Information Center

    Carnoy, Martin; Khavenson, Tatiana; Ivanova, Alina

    2015-01-01

    In this paper, we develop a multi-level comparative approach to analyse Trends in International Mathematics and Science Survey (TIMSS) and Programme of International Student Achievement (PISA) mathematics results for a country, Russia, where the two tests provide contradictory information about students' relative performance. Russian students do…

  16. The Impact of a Flexible Assessment System on Students' Motivation, Performance and Attitude

    ERIC Educational Resources Information Center

    Pacharn, Parunchana; Bay, Darlene; Felton, Sandra

    2013-01-01

    We examine a flexible assessment system that allows students to determine the weights allocated to each course component and to re-allocate the weights in response to achieved scores. The flexibility is intended to encourage students' participation in the learning process, thereby promoting self-regulated learning skills. We compare this…

  17. Promoting Learning and Achievement through Self-Assessment

    ERIC Educational Resources Information Center

    Andrade, Heidi; Valtcheva, Anna

    2009-01-01

    Criteria-referenced self-assessment is a process during which students collect information about their own performance or progress; compare it to explicitly stated criteria, goals, or standards; and revise accordingly. The authors argue that self-assessment must be a formative type of assessment, done on drafts of works in progress: It should not…

  18. Student Perceptions of Teacher Characteristics on Math Achievement for Middle School African American Students

    ERIC Educational Resources Information Center

    Clayton, Otis, Jr.

    2013-01-01

    This causal-comparative research explored how African American students' perceptions of their math teachers affected their academic performance on the Math Tennessee Comprehensive Assessment Program (TCAP) Test during 2009-2010 academic year. When considering possible measures of teacher effectiveness in K-12 education, it can be argued that…

  19. Cultures of Learning in Effective High Schools

    ERIC Educational Resources Information Center

    Tichnor-Wagner, Ariel; Harrison, Christopher; Cohen-Vogel, Lora

    2016-01-01

    Purpose: Research indicates that a culture of learning is a key factor in building high schools that foster academic achievement in all students. Yet less is known about which elements of a culture of learning differentiate schools with higher levels of academic performance. To fill this gap, this comparative case study examined the cultures of…

  20. The Effects of Curriculum Integration on the Academic Achievement of Secondary Career and Technical Students

    ERIC Educational Resources Information Center

    Jones, Patricia Anders

    2012-01-01

    Using a causal-comparative design, this quantitative study investigated whether or not the curriculum integration of academic subjects with career and technical education classes affected secondary students' academic performance as assessed by scores on standardized tests. The purposive sample was drawn from students in Trade and Industry classes…

  1. The Practice of Co-Creating Leadership in High- and Low-Performing High Schools

    ERIC Educational Resources Information Center

    Jarrett, Ehren; Wasonga, Teresa; Murphy, John

    2010-01-01

    Purpose: The purpose of this paper is to examine teacher perceptions of the practice of co-creating leadership and its potential impacts on student achievement. Design/methodology/approach: Using a quantitative approach, the study compared the levels of the practice of co-creating leadership dispositional values and institutional conditions that…

  2. Reading Disabilities in Adults: A Selective Meta-Analysis of the Literature

    ERIC Educational Resources Information Center

    Swanson, H. Lee; Hsieh, Ching-Ju

    2009-01-01

    This article synthesizes the experimental literature that compares the academic, cognitive, and behavioral performance of adults with reading disabilities to those of average-achieving adult readers. The central question posed by this review is to what extent and in what manner do adults with reading disabilities differ from adults without reading…

  3. How Need for Cognition Affects the Processing of Achievement-Related Information

    ERIC Educational Resources Information Center

    Dickhauser, Oliver; Reinhard, Marc-Andre; Diener, Claudia; Bertrams, Alex

    2009-01-01

    The present article analyzed, how need for cognition (NFC) influences the formation of performance expectancies. When processing information, individuals with lower NFC often rely on salient information and shortcuts compared to individuals higher in NFC. We assume that these preferences of processing will also make individuals low in NFC more…

  4. Do Specific Classroom Reading Activities Predict English Language Learners' Later Reading Achievement?

    ERIC Educational Resources Information Center

    Swanson, H. Lee; Orosco, Michael J.; Kudo, Milagros Fatima

    2017-01-01

    This study investigated the relationship between elementary classroom (N = 50) reading activities in Year 1 and reading performance (i.e., passage comprehension, letter-word identification, and word attack) 1 year later for English language learners (ELLs; N = 270). A cross-classification hierarchical model indicated that compared to other reading…

  5. Naming Speed of Adolescents and Young Adults with Attention Deficit Hyperactivity Disorder: Differences in Alphanumeric Versus Color/Object Naming.

    PubMed

    Whipple, Brittany D; Nelson, Jason M

    2016-02-01

    This study investigated the performance of adolescents and young adults with Attention Deficit Hyperactivity Disorder (ADHD), Reading Disorder (RD), and ADHD/RD on measures of alphanumeric and nonalphanumeric naming speed and the relationship between naming speed and academic achievement. The sample (N = 203) included students aged 17-28 years diagnosed with ADHD (n = 83), RD (n = 71), or ADHD/RD (n = 49). Individuals with ADHD performed significantly faster on measures of alphanumeric naming compared with RD and comorbid groups and, within group, demonstrated significantly quicker naming of letters/digits compared with colors/objects. Both alphanumeric rapid naming scores and processing speed scores variably predicted academic achievement scores across groups, whereas nonalphanumeric rapid naming only predicted reading comprehension scores within the ADHD group. Results support findings that older individuals with ADHD show relative weakness in rapid naming of objects and colors. Implications of these findings in regard to assessment of older individuals for ADHD are discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Mechanically activated fly ash as a high performance binder for civil engineering

    NASA Astrophysics Data System (ADS)

    Rieger, D.; Kullová, L.; Čekalová, M.; Novotný, P.; Pola, M.

    2017-01-01

    This study is aimed for investigation of fly ash binder with suitable properties for civil engineering needs. The fly ash from Czech brown coal power plant Prunerov II was used and mechanically activated to achieve suitable particle size for alkaline activation of hardening process. This process is driven by dissolution of aluminosilicate content of fly ash and by subsequent development of inorganic polymeric network called geopolymer. Hardening kinetics at 25 and 30 °C were measured by strain controlled small amplitude oscillatory rheometry with strain of 0.01 % and microstructure of hardened binder was evaluated by scanning electron microscopy. Strength development of hardened binder was investigated according to compressional and flexural strength for a period of 180 days. Our investigation finds out, that mechanically activated fly ash can be comparable to metakaolin geopolymers, according to setting time and mechanical parameters even at room temperature curing. Moreover, on the bases of long time strength development, achieved compressional strength of 134.5 after 180 days is comparable to performance of high grade Portland cement concretes.

  7. A hybrid brain-computer interface based on the fusion of electroencephalographic and electromyographic activities

    NASA Astrophysics Data System (ADS)

    Leeb, Robert; Sagha, Hesam; Chavarriaga, Ricardo; Millán, José del R.

    2011-04-01

    Hybrid brain-computer interfaces (BCIs) are representing a recent approach to develop practical BCIs. In such a system disabled users are able to use all their remaining functionalities as control possibilities in parallel with the BCI. Sometimes these people have residual activity of their muscles. Therefore, in the presented hybrid BCI framework we want to explore the parallel usage of electroencephalographic (EEG) and electromyographic (EMG) activity, whereby the control abilities of both channels are fused. Results showed that the participants could achieve a good control of their hybrid BCI independently of their level of muscular fatigue. Thereby the multimodal fusion approach of muscular and brain activity yielded better and more stable performance compared to the single conditions. Even in the case of an increasing muscular fatigue a good control (moderate and graceful degradation of the performance compared to the non-fatigued case) and a smooth handover could be achieved. Therefore, such systems allow the users a very reliable hybrid BCI control although they are getting more and more exhausted or fatigued during the day.

  8. Characterization of new types of stationary phases for fast and ultra-fast liquid chromatography by signal processing based on AutoCovariance Function: a case study of application to Passiflora incarnata L. extract separations.

    PubMed

    Pietrogrande, Maria Chiara; Dondi, Francesco; Ciogli, Alessia; Gasparrini, Francesco; Piccin, Antonella; Serafini, Mauro

    2010-06-25

    In this study, a comparative investigation was performed of HPLC Ascentis (2.7 microm particles) columns based on fused-core particle technology and Acquity (1.7 microm particles) columns requiring UPLC instruments, in comparison with Chromolith RP-18e columns. The study was carried out on mother and vegetal tinctures of Passiflora incarnata L. on one single or two coupled columns. The fundamental attributions of the chromatographic profiles are evaluated using a chemometric procedure, based on the AutoCovariance Function (ACVF). Different chromatographic systems are compared in terms of their separation parameters, i.e., number of total chemical components (m(tot)), separation efficiency (sigma), peak capacity (n(c)), overlap degree of peaks and peak purity. The obtained results show the improvements achieved by HPLC columns with narrow size particles in terms of total analysis time and chromatographic efficiency: comparable performance are achieved by Ascentis (2.7 microm particle) column and Acquity (1.7 microm particle) column requiring UPLC instruments. The ACVF plot is proposed as a simplified tool describing the chromatographic fingerprint to be used for evaluating and comparing chemical composition of plant extracts by using the parameters D% - relative abundance of the deterministic component - and c(EACF) - similarity index computed on ACVF. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Training of Visual-Spatial Working Memory in Preschool Children

    PubMed Central

    Gade, Miriam; Zoelch, Christof; Seitz-Stein, Katja

    2017-01-01

    Working memory, the ability to store and manipulate information is of great importance for scholastic achievement in children. In this study, we report four studies in which preschoolers were trained on a visual-spatial working memory span task, namely the Corsi Block Task. Across all four studies, we found significant training effects for the intervention groups compared to active control groups. Confirming recent research, no transfer effects to other working memory tasks were found. Most importantly, our training effects were mainly brought about by children performing below the median in the pretest and those showing median performance, thereby closing the gap to children performing above the median (compensation effect). We consider this finding of great interest to ensure comparable starting conditions when entering school with a relatively short intervention. PMID:28713452

  10. Textual production of children without learning difficulties.

    PubMed

    Santos, Maria Aparecida Gonçalves dos; Hage, Simone Rocha de Vasconcellos

    2015-01-01

    To characterize the writing skills of students, to compare the performance of students in public and private schools, and to identify enhancements in the course of the school year. Three texts (narrative, game rules description, and a note or letter) written by 160 students from public and private schools were analyzed based on a specific protocol. Descriptive statistical analysis was performed. To compare the overall performance by the protocol between school grades, the Kruskal-Wallis and Miller tests were used, and to compare results as to schools (private and public), Mann-Whitney test was used. Median values of aesthetic aspects, coherence, clarity, and concision for game rules description among public school students remained one point below the top score. Students from private schools achieved the highest score at medians. When comparing schools, private institutions had students with better performances, with significant difference. As to grades, statistical difference was found between the fourth and sixth grades of public schools and between the fourth and fifth grades of private schools. Most of the private school children showed consolidation of skills assessed in the different grades. However, public school children had this consolidation only at the sixth grade. Students from private schools had better performances compared to those from public schools. There is tendency to evolution from the fourth to sixth grades in public schools. However, the overall performance is similar in all grades in private schools.

  11. A Randomized Controlled Pilot Intervention Study of a Mindfulness-Based Self-Leadership Training (MBSLT) on Stress and Performance.

    PubMed

    Sampl, Juliane; Maran, Thomas; Furtner, Marco R

    2017-01-01

    The present randomized pilot intervention study examines the effects of a mindfulness-based self-leadership training (MBSLT) specifically developed for academic achievement situations. Both mindfulness and self-leadership have a strong self-regulatory focus and are helpful in terms of stress resilience and performance enhancements. Based on several theoretical points of contact and a specific interplay between mindfulness and self-leadership, the authors developed an innovative intervention program that improves mood as well as performance in a real academic setting. The intervention was conducted as a randomized controlled study over 10 weeks. The purpose was to analyze the effects on perceived stress, test anxiety, academic self-efficacy, and the performance of students by comparing an intervention and control group ( n  = 109). Findings demonstrated significant effects on mindfulness, self-leadership, academic self-efficacy, and academic performance improvements in the intervention group. Results showed that the intervention group reached significantly better grade point averages than the control group. Moreover, the MBSLT over time led to a reduction of test anxiety in the intervention group compared to the control group. Furthermore, while participants of the control group showed an increase in stress over time, participants of the intervention group maintained constant stress levels over time. The combination of mindfulness and self-leadership addressed both positive effects on moods and on objective academic performance. The effects demonstrate the great potential of combining mindfulness with self-leadership to develop a healthy self-regulatory way of attaining achievement-related goals and succeeding in high-stress academic environments.

  12. Animation-assisted CPRII program as a reminder tool in achieving effective one-person-CPR performance.

    PubMed

    Choa, Minhong; Cho, Junho; Choi, Young Hwan; Kim, Seungho; Sung, Ji Min; Chung, Hyun Soo

    2009-06-01

    The objective of this study is to compare the skill retention of two groups of lay persons, six months after their last CPR training. The intervention group was provided with animation-assisted CPRII (AA-CPRII) instruction on their cellular phones, and the control group had nothing but what they learned from their previous training. This study was a single blind randomized controlled trial. The participants' last CPR trainings were held at least six months ago. We revised our CPR animation for on-site CPR instruction content emphasizing importance of chest compression. Participants were randomized into two groups, the AA-CPRII group (n=42) and the control group (n=38). Both groups performed three cycles of CPR and their performances were video recorded. These video clips were assessed by three evaluators using a checklist. The psychomotor skills were evaluated using the ResusciAnne SkillReporter. Using the 30-point scoring checklist, the AA-CPRII group had a significantly better score compared to the control group (p<0.001). Psychomotor skills evaluated with the AA-CPRII group demonstrated better performance in hand positioning (p=0.025), compression depth (p=0.035) and compression rate (p<0.001) than the control group. The AA-CPRII group resulted in better checklist scores, including chest compression rate, depth and hand positioning. Animation-assisted CPR could be used as a reminder tool in achieving effective one-person-CPR performance. By installing the CPR instruction on cellular phones and having taught them CPR with it during the training enabled participants to perform better CPR.

  13. A Comparative Study of Hawaii Middle School Science Student Academic Achievement

    NASA Astrophysics Data System (ADS)

    Askew Cain, Peggy

    The problem was middle-grade students with specific learning disabilities (SWDs) in reading comprehension perform less well than their peers on standardized assessments. The purpose of this quantitative comparative study was to examine the effect of electronic concept maps on reading comprehension of eighth grade students with SWD reading comprehension in a Hawaii middle school Grade 8 science class on the island of Oahu. The target population consisted of Grade 8 science students for school year 2015-2016. The sampling method was a purposeful sampling with a final sample size of 338 grade 8 science students. De-identified archival records of grade 8 Hawaii standardized science test scores were analyzed using a one way analysis of variance (ANOVA) in SPSS. The finding for hypothesis 1 indicated a significant difference in student achievement between SWDs and SWODs as measured by Hawaii State Assessment (HSA) in science scores (p < 0.05), and for hypothesis 2, a significant difference in instructional modality for SWDs who used concept maps and does who did not as measured by the Hawaii State Assessment in science (p < 0.05). The implications of the findings (a) SWDs performed less well in science achievement than their peers and consequently, and (b) SWODs appeared to remember greater degrees of science knowledge, and answered more questions correctly than SWDs as a result of reading comprehension. Recommendations for practice were for educational leadership and noted: (a) teachers should practice using concept maps with SWDs as a specific reading strategy to support reading comprehension in science classes, (b) involve a strong focus on vocabulary building and concept building during concept map construction because the construction of concept maps sometimes requires frontloading of vocabulary, and (c) model for teachers how concept maps are created and to explain their educational purpose as a tool for learning. Recommendations for future research were to conduct (a) a quantitative comparative study between groups for academic achievement of subtests mean scores of SWDs and SWODs in physical science, earth science, and space science, and (b) a quantitative correlation study to examine relationships and predictive values for academic achievement of SWDs and concept map integration on standardized science assessments.

  14. Simultaneously driven linear and nonlinear spatial encoding fields in MRI.

    PubMed

    Gallichan, Daniel; Cocosco, Chris A; Dewdney, Andrew; Schultz, Gerrit; Welz, Anna; Hennig, Jürgen; Zaitsev, Maxim

    2011-03-01

    Spatial encoding in MRI is conventionally achieved by the application of switchable linear encoding fields. The general concept of the recently introduced PatLoc (Parallel Imaging Technique using Localized Gradients) encoding is to use nonlinear fields to achieve spatial encoding. Relaxing the requirement that the encoding fields must be linear may lead to improved gradient performance or reduced peripheral nerve stimulation. In this work, a custom-built insert coil capable of generating two independent quadratic encoding fields was driven with high-performance amplifiers within a clinical MR system. In combination with the three linear encoding fields, the combined hardware is capable of independently manipulating five spatial encoding fields. With the linear z-gradient used for slice-selection, there remain four separate channels to encode a 2D-image. To compare trajectories of such multidimensional encoding, the concept of a local k-space is developed. Through simulations, reconstructions using six gradient-encoding strategies were compared, including Cartesian encoding separately or simultaneously on both PatLoc and linear gradients as well as two versions of a radial-based in/out trajectory. Corresponding experiments confirmed that such multidimensional encoding is practically achievable and demonstrated that the new radial-based trajectory offers the PatLoc property of variable spatial resolution while maintaining finite resolution across the entire field-of-view. Copyright © 2010 Wiley-Liss, Inc.

  15. Global Magnetohydrodynamic Simulation Using High Performance FORTRAN on Parallel Computers

    NASA Astrophysics Data System (ADS)

    Ogino, T.

    High Performance Fortran (HPF) is one of modern and common techniques to achieve high performance parallel computation. We have translated a 3-dimensional magnetohydrodynamic (MHD) simulation code of the Earth's magnetosphere from VPP Fortran to HPF/JA on the Fujitsu VPP5000/56 vector-parallel supercomputer and the MHD code was fully vectorized and fully parallelized in VPP Fortran. The entire performance and capability of the HPF MHD code could be shown to be almost comparable to that of VPP Fortran. A 3-dimensional global MHD simulation of the earth's magnetosphere was performed at a speed of over 400 Gflops with an efficiency of 76.5 VPP5000/56 in vector and parallel computation that permitted comparison with catalog values. We have concluded that fluid and MHD codes that are fully vectorized and fully parallelized in VPP Fortran can be translated with relative ease to HPF/JA, and a code in HPF/JA may be expected to perform comparably to the same code written in VPP Fortran.

  16. A visual ergonomic evaluation of different screen types and screen technologies with respect to discrimination performance.

    PubMed

    Oetjen, Sophie; Ziefle, Martina

    2009-01-01

    An increasing demand to work with electronic displays and to use mobile computers emphasises the need to compare visual performance while working with different screen types. In the present study, a cathode ray tube (CRT) was compared to an external liquid crystal display (LCD) and a Notebook-LCD. The influence of screen type and viewing angle on discrimination performance was studied. Physical measurements revealed that luminance and contrast values change with varying viewing angles (anisotropy). This is most pronounced in Notebook-LCDs, followed by external LCDs and CRTs. Performance data showed that LCD's anisotropy has negative impacts on completing time critical visual tasks. The best results were achieved when a CRT was used. The largest deterioration of performance resulted when participants worked with a Notebook-LCD. When it is necessary to react quickly and accurately, LCD screens have disadvantages. The anisotropy of LCD-TFTs is therefore considered to be as a limiting factor deteriorating visual performance.

  17. 3D electroplated inductors with thickness variation for improved broadband performance

    NASA Astrophysics Data System (ADS)

    Farm-Guoo Tseng, Victor; Bedair, Sarah S.; Lazarus, Nathan

    2017-01-01

    The performance of an RF spiral inductor is based on the balance between ohmic losses in the outer turns and eddy current losses dominant in the inner turns where the magnetic field is the strongest. In this work, air-core spiral inductors with winding trace thicknesses decreasing towards the center are demonstrated, achieving quality factor improvement over a wide frequency range compared to uniform thickness inductors. A custom 3D copper electroplating process was used to produce spiral inductors with varying winding thicknesses in a single plating step, with patterned gaps in a seed layer used to create delays in the vertical plating. The fabricated center-lowered coil inductors were 80 nH within a one square millimeter area with thickness varying from 60 µm to 10 µm from outer to inner winding. Within the 16 MHz-160 MHz range, the center-lowered inductors were shown to have a maximum to minimum quality factor improvement of 90%-10% when compared to uniform thickness inductors with thicknesses ranging from 60 µm to 10 µm. Compared to the 20 µm uniform thickness inductor which has the optimal performance among all uniform thickness inductors in this frequency range, the center-lowered inductors were shown to achieve a maximum quality factor improvement of 20% at the edge frequencies of 16 MHz and 160 MHz, and a minimum quality factor improvement of 10% near the geometric mean center frequency of 46 MHz.

  18. Efficient Lead-Free Solar Cells Based on Hollow {en}MASnI3 Perovskites.

    PubMed

    Ke, Weijun; Stoumpos, Constantinos C; Spanopoulos, Ioannis; Mao, Lingling; Chen, Michelle; Wasielewski, Michael R; Kanatzidis, Mercouri G

    2017-10-18

    Tin-based perovskites have very comparable electronic properties to lead-based perovskites and are regarded as possible lower toxicity alternates for solar cell applications. However, the efficiency of tin-based perovskite solar cells is still low and they exhibit poor air stability. Here, we report lead-free tin-based solar cells with greatly enhanced performance and stability using so-called "hollow" ethylenediammonium and methylammonium tin iodide ({en}MASnI 3 ) perovskite as absorbers. Our results show that en can improve the film morphology and most importantly can serve as a new cation to be incorporated into the 3D MASnI 3 lattice. When the cation of en becomes part of the 3D structure, a high density of SnI 2 vacancies is created resulting in larger band gap, larger unit cell volume, lower trap-state density, and much longer carrier lifetime compared to classical MASnI 3 . The best-performing {en}MASnI 3 solar cell has achieved a high efficiency of 6.63% with an open circuit voltage of 428.67 mV, a short-circuit current density of 24.28 mA cm -2 , and a fill factor of 63.72%. Moreover, the {en}MASnI 3 device shows much better air stability than the neat MASnI 3 device. Comparable performance is also achieved for cesium tin iodide solar cells with en loading, demonstrating the broad scope of this approach.

  19. A 60 GOPS/W, -1.8 V to 0.9 V body bias ULP cluster in 28 nm UTBB FD-SOI technology

    NASA Astrophysics Data System (ADS)

    Rossi, Davide; Pullini, Antonio; Loi, Igor; Gautschi, Michael; Gürkaynak, Frank K.; Bartolini, Andrea; Flatresse, Philippe; Benini, Luca

    2016-03-01

    Ultra-low power operation and extreme energy efficiency are strong requirements for a number of high-growth application areas, such as E-health, Internet of Things, and wearable Human-Computer Interfaces. A promising approach to achieve up to one order of magnitude of improvement in energy efficiency over current generation of integrated circuits is near-threshold computing. However, frequency degradation due to aggressive voltage scaling may not be acceptable across all performance-constrained applications. Thread-level parallelism over multiple cores can be used to overcome the performance degradation at low voltage. Moreover, enabling the processors to operate on-demand and over a wide supply voltage and body bias ranges allows to achieve the best possible energy efficiency while satisfying a large spectrum of computational demands. In this work we present the first ever implementation of a 4-core cluster fabricated using conventional-well 28 nm UTBB FD-SOI technology. The multi-core architecture we present in this work is able to operate on a wide range of supply voltages starting from 0.44 V to 1.2 V. In addition, the architecture allows a wide range of body bias to be applied from -1.8 V to 0.9 V. The peak energy efficiency 60 GOPS/W is achieved at 0.5 V supply voltage and 0.5 V forward body bias. Thanks to the extended body bias range of conventional-well FD-SOI technology, high energy efficiency can be guaranteed for a wide range of process and environmental conditions. We demonstrate the ability to compensate for up to 99.7% of chips for process variation with only ±0.2 V of body biasing, and compensate temperature variation in the range -40 °C to 120 °C exploiting -1.1 V to 0.8 V body biasing. When compared to leading-edge near-threshold RISC processors optimized for extremely low power applications, the multi-core architecture we propose has 144× more performance at comparable energy efficiency levels. Even when compared to other low-power processors with comparable performance, including those implemented in 28 nm technology, our platform provides 1.4× to 3.7× better energy efficiency.

  20. Computational Evaluation of the Steady and Pulsed Jet Effects on the Performance of a Circulation Control Wing Section

    NASA Technical Reports Server (NTRS)

    Liu, Yi; Sankar, Lakshmi N.; Englar, Robert J.; Ahuja, Krishan K.; Gaeta, R.

    2005-01-01

    Circulation Control technology is a very effective way of achieving high lift forces required by aircraft during take-off and landing. This technology can also directly control the flow field over the wing. Compared to a conventional high-lift system, a Circulation Control Wing (CCW) can generate comparable or higher lift forces during take-off/landing with fewer or no moving parts and much less complexity. In this work, an unsteady three-dimensional Navier-Stokes analysis procedure has been developed and applied to Circulation Control Wing configurations. The effects of 2-D steady jets and 2-D pulsed jets on the aerodynamic performance of CCW airfoils have been investigated. It is found that a steady jet can generate very high lift at zero angle of attack without stall, and that a small amount of blowing can eliminate vortex shedding at the trailing edge, a potential noise source. It is also found that a pulsed jet can achieve the same high lift as a steady jet at lower mass flow rates, especially at a high frequency, and that the Strouhal number has a more dominant effect on the pulsed jet performance than just the frequency or the free-stream velocity.

  1. X-ray nanofocusing by kinoform lenses: A comparative study using different modeling approaches

    NASA Astrophysics Data System (ADS)

    Yan, Hanfei

    2010-02-01

    We conduct a comparative study on various kinoform lenses (KLs) for x-ray nanofocusing by using the geometrical theory, the dynamical diffraction theory, and the beam propagation method. This study shows that the geometrical theory becomes invalid to describe the performance of a KL for nanofocusing. The strong edge diffraction effect from individual lens element, which distorts the desired wave field, leads to a reduction in the effective numerical aperture and imposes a limit on how small a focus a KL can achieve. Because this effect is associated with a finite thickness of a lens, larger lens thickness depicts a stronger distortion. We find that a short KL where all lens elements are folded back to a single plane shows an illumination preference: if the illuminating geometry is in favor of the Bragg diffraction for a focusing order, its performance is enhanced and vice versa. We also find that a short KL usually outperforms its long version where all lens elements do not lie in a single plane because the short one suffers less the wave field distortion due to the edge diffraction. Simulation results suggest that for a long KL, an adaptive lens design is needed to correct the wave field distortion in order to achieve a better performance.

  2. Coupling Light Emitting Diodes with Photocatalyst-Coated Optical Fibers Improves Quantum Yield of Pollutant Oxidation.

    PubMed

    Ling, Li; Tugaoen, Heather; Brame, Jonathon; Sinha, Shahnawaz; Li, Chuanhao; Schoepf, Jared; Hristovski, Kiril; Kim, Jae-Hong; Shang, Chii; Westerhoff, Paul

    2017-11-21

    A photocatalyst-coated optical fiber was coupled with a 318 nm ultraviolet-A light emitting diode, which activated the photocatalysts by interfacial photon-electron excitation while minimizing photonic energy losses due to conventional photocatalytic barriers. The light delivery mechanism was explored via modeling of evanescent wave energy produced upon total internal reflection and photon refraction into the TiO 2 surface coating. This work explores aqueous phase LED-irradiated optical fibers for treating organic pollutants and for the first time proposes a dual-mechanistic approach to light delivery and photocatalytic performance. Degradation of a probe organic pollutant was evaluated as a function of optical fiber coating thickness, fiber length, and photocatalyst attachment method and compared against the performance of an equivalent catalyst mass in a completely mixed slurry reactor. Measured and simulated photon fluence through the optical fibers decreased as a function of fiber length, coating thickness, or TiO 2 mass externally coated on the fiber. Thinner TiO 2 coatings achieved faster pollutant removal rates from solution, and dip coating performed better than sol-gel attachment methods. TiO 2 attached to optical fibers achieved a 5-fold higher quantum yield compared against an equivalent mass of TiO 2 suspended in a slurry solution.

  3. Proficiency-based laparoscopic and endoscopic training with virtual reality simulators: a comparison of proctored and independent approaches.

    PubMed

    Snyder, Christopher W; Vandromme, Marianne J; Tyra, Sharon L; Hawn, Mary T

    2009-01-01

    Virtual reality (VR) simulators for laparoscopy and endoscopy may be valuable tools for resident education. However, the cost of such training in terms of trainee and instructor time may vary depending upon whether an independent or proctored approach is employed. We performed a randomized controlled trial to compare independent and proctored methods of proficiency-based VR simulator training. Medical students were randomized to independent or proctored training groups. Groups were compared with respect to the number of training hours and task repetitions required to achieve expert level proficiency on laparoscopic and endoscopic simulators. Cox regression modeling was used to compare time to proficiency between groups, with adjustment for appropriate covariates. Thirty-six medical students (18 independent, 18 proctored) were enrolled. Achievement of overall simulator proficiency required a median of 11 hours of training (range, 6-21 hours). Laparoscopic and endoscopic proficiency were achieved after a median of 11 (range, 6-32) and 10 (range, 5-27) task repetitions, respectively. The number of repetitions required to achieve proficiency was similar between groups. After adjustment for covariates, trainees in the independent group achieved simulator proficiency with significantly fewer hours of training (hazard ratio, 2.62; 95% confidence interval, 1.01-6.85; p = 0.048). Our study quantifies the cost, in instructor and trainee hours, of proficiency-based laparoscopic and endoscopic VR simulator training, and suggests that proctored instruction does not offer any advantages to trainees. The independent approach may be preferable for surgical residency programs desiring to implement VR simulator training.

  4. Indoor Pedestrian Localization Using iBeacon and Improved Kalman Filter.

    PubMed

    Sung, Kwangjae; Lee, Dong Kyu 'Roy'; Kim, Hwangnam

    2018-05-26

    The reliable and accurate indoor pedestrian positioning is one of the biggest challenges for location-based systems and applications. Most pedestrian positioning systems have drift error and large bias due to low-cost inertial sensors and random motions of human being, as well as unpredictable and time-varying radio-frequency (RF) signals used for position determination. To solve this problem, many indoor positioning approaches that integrate the user's motion estimated by dead reckoning (DR) method and the location data obtained by RSS fingerprinting through Bayesian filter, such as the Kalman filter (KF), unscented Kalman filter (UKF), and particle filter (PF), have recently been proposed to achieve higher positioning accuracy in indoor environments. Among Bayesian filtering methods, PF is the most popular integrating approach and can provide the best localization performance. However, since PF uses a large number of particles for the high performance, it can lead to considerable computational cost. This paper presents an indoor positioning system implemented on a smartphone, which uses simple dead reckoning (DR), RSS fingerprinting using iBeacon and machine learning scheme, and improved KF. The core of the system is the enhanced KF called a sigma-point Kalman particle filter (SKPF), which localize the user leveraging both the unscented transform of UKF and the weighting method of PF. The SKPF algorithm proposed in this study is used to provide the enhanced positioning accuracy by fusing positional data obtained from both DR and fingerprinting with uncertainty. The SKPF algorithm can achieve better positioning accuracy than KF and UKF and comparable performance compared to PF, and it can provide higher computational efficiency compared with PF. iBeacon in our positioning system is used for energy-efficient localization and RSS fingerprinting. We aim to design the localization scheme that can realize the high positioning accuracy, computational efficiency, and energy efficiency through the SKPF and iBeacon indoors. Empirical experiments in real environments show that the use of the SKPF algorithm and iBeacon in our indoor localization scheme can achieve very satisfactory performance in terms of localization accuracy, computational cost, and energy efficiency.

  5. Optimization and performance improvement of an electromagnetic-type energy harvester with consideration of human walking vibration

    NASA Astrophysics Data System (ADS)

    Seo, Jongho; Kim, Jin-Su; Jeong, Un-Chang; Kim, Yong-Dae; Kim, Young-Cheol; Lee, Hanmin; Oh, Jae-Eung

    2016-02-01

    In this study, we derived an equation of motion for an electromechanical system in view of the components and working mechanism of an electromagnetic-type energy harvester (ETEH). An electromechanical transduction factor (ETF) was calculated using a finite-element analysis (FEA) based on Maxwell's theory. The experimental ETF of the ETEH measured by means of sine wave excitation was compared with and FEA data. Design parameters for the stationary part of the energy harvester were optimized in terms of the power performance by using a response surface method (RSM). With optimized design parameters, the ETEH showed an improvement in performance. We experimented with the optimized ETEH (OETEH) with respect to changes in the external excitation frequency and the load resistance by taking human body vibration in to account. The OETEH achieved a performance improvement of about 30% compared to the initial model.

  6. Associations between children's intelligence and academic achievement: the role of sleep.

    PubMed

    Erath, Stephen A; Tu, Kelly M; Buckhalt, Joseph A; El-Sheikh, Mona

    2015-10-01

    Sleep problems (long wake episodes, low sleep efficiency) were examined as moderators of the relation between children's intelligence and academic achievement. The sample was comprised of 280 children (55% boys; 63% European Americans, 37% African Americans; mean age = 10.40 years, SD = 0.65). Sleep was assessed during seven consecutive nights of actigraphy. Children's performance on standardized tests of intelligence (Brief Intellectual Ability index of the Woodcock-Johnson III) and academic achievement (Alabama Reading and Math Test) were obtained. Age, sex, ethnicity, income-to-needs ratio, single parent status, standardized body mass index, chronic illness and pubertal development were controlled in analyses. Higher intelligence was strongly associated with higher academic achievement across a wide range of sleep quality. However, the association between intelligence and academic achievement was slightly attenuated among children with more long wake episodes or lower sleep efficiency compared with children with higher-quality sleep. © 2015 European Sleep Research Society.

  7. A Complex Prime Numerical Representation of Amino Acids for Protein Function Comparison.

    PubMed

    Chen, Duo; Wang, Jiasong; Yan, Ming; Bao, Forrest Sheng

    2016-08-01

    Computationally assessing the functional similarity between proteins is an important task of bioinformatics research. It can help molecular biologists transfer knowledge on certain proteins to others and hence reduce the amount of tedious and costly benchwork. Representation of amino acids, the building blocks of proteins, plays an important role in achieving this goal. Compared with symbolic representation, representing amino acids numerically can expand our ability to analyze proteins, including comparing the functional similarity of them. Among the state-of-the-art methods, electro-ion interaction pseudopotential (EIIP) is widely adopted for the numerical representation of amino acids. However, it could suffer from degeneracy that two different amino acid sequences have the same numerical representation, due to the design of EIIP. In light of this challenge, we propose a complex prime numerical representation (CPNR) of amino acids, inspired by the similarity between a pattern among prime numbers and the number of codons of amino acids. To empirically assess the effectiveness of the proposed method, we compare CPNR against EIIP. Experimental results demonstrate that the proposed method CPNR always achieves better performance than EIIP. We also develop a framework to combine the advantages of CPNR and EIIP, which enables us to improve the performance and study the unique characteristics of different representations.

  8. Improvement in QEPAS system utilizing a second harmonic based wavelength calibration technique

    NASA Astrophysics Data System (ADS)

    Zhang, Qinduan; Chang, Jun; Wang, Fupeng; Wang, Zongliang; Xie, Yulei; Gong, Weihua

    2018-05-01

    A simple laser wavelength calibration technique, based on second harmonic signal, is demonstrated in this paper to improve the performance of quartz enhanced photoacoustic spectroscopy (QEPAS) gas sensing system, e.g. improving the signal to noise ratio (SNR), detection limit and long-term stability. Constant current, corresponding to the gas absorption line, combining f/2 frequency sinusoidal signal are used to drive the laser (constant driving mode), a software based real-time wavelength calibration technique is developed to eliminate the wavelength drift due to ambient fluctuations. Compared to conventional wavelength modulation spectroscopy (WMS), this method allows lower filtering bandwidth and averaging algorithm applied to QEPAS system, improving SNR and detection limit. In addition, the real-time wavelength calibration technique guarantees the laser output is modulated steadily at gas absorption line. Water vapor is chosen as an objective gas to evaluate its performance compared to constant driving mode and conventional WMS system. The water vapor sensor was designed insensitive to the incoherent external acoustic noise by the numerical averaging technique. As a result, the SNR increases 12.87 times in wavelength calibration technique based system compared to conventional WMS system. The new system achieved a better linear response (R2 = 0 . 9995) in concentration range from 300 to 2000 ppmv, and achieved a minimum detection limit (MDL) of 630 ppbv.

  9. The 'Alternative Quality Contract,' based on a global budget, lowered medical spending and improved quality.

    PubMed

    Song, Zirui; Safran, Dana Gelb; Landon, Bruce E; Landrum, Mary Beth; He, Yulei; Mechanic, Robert E; Day, Matthew P; Chernew, Michael E

    2012-08-01

    Seven provider organizations in Massachusetts entered the Blue Cross Blue Shield Alternative Quality Contract in 2009, followed by four more organizations in 2010. This contract, based on a global budget and pay-for-performance for achieving certain quality benchmarks, places providers at risk for excessive spending and rewards them for quality, similar to the new Pioneer Accountable Care Organizations in Medicare. We analyzed changes in spending and quality associated with the Alternative Quality Contract and found that the rate of increase in spending slowed compared to control groups, more so in the second year than in the first. Overall, participation in the contract over two years led to savings of 2.8 percent (1.9 percent in year 1 and 3.3 percent in year 2) compared to spending in nonparticipating groups. Savings were accounted for by lower prices achieved through shifting procedures, imaging, and tests to facilities with lower fees, as well as reduced utilization among some groups. Quality of care also improved compared to control organizations, with chronic care management, adult preventive care, and pediatric care within the contracting groups improving more in year 2 than in year 1. These results suggest that global budgets with pay-for-performance can begin to slow underlying growth in medical spending while improving quality of care.

  10. Optic-null space medium for cover-up cloaking without any negative refraction index materials

    PubMed Central

    Sun, Fei; He, Sailing

    2016-01-01

    With the help of optic-null medium, we propose a new way to achieve invisibility by covering up the scattering without using any negative refraction index materials. Compared with previous methods to achieve invisibility, the function of our cloak is to cover up the scattering of the objects to be concealed by a background object of strong scattering. The concealed object can receive information from the outside world without being detected. Numerical simulations verify the performance of our cloak. The proposed method will be a great addition to existing invisibility technology. PMID:27383833

  11. Optic-null space medium for cover-up cloaking without any negative refraction index materials.

    PubMed

    Sun, Fei; He, Sailing

    2016-07-07

    With the help of optic-null medium, we propose a new way to achieve invisibility by covering up the scattering without using any negative refraction index materials. Compared with previous methods to achieve invisibility, the function of our cloak is to cover up the scattering of the objects to be concealed by a background object of strong scattering. The concealed object can receive information from the outside world without being detected. Numerical simulations verify the performance of our cloak. The proposed method will be a great addition to existing invisibility technology.

  12. A comparison of foveated acquisition and tracking performance relative to uniform resolution approaches

    NASA Astrophysics Data System (ADS)

    Dubuque, Shaun; Coffman, Thayne; McCarley, Paul; Bovik, A. C.; Thomas, C. William

    2009-05-01

    Foveated imaging has been explored for compression and tele-presence, but gaps exist in the study of foveated imaging applied to acquisition and tracking systems. Results are presented from two sets of experiments comparing simple foveated and uniform resolution targeting (acquisition and tracking) algorithms. The first experiments measure acquisition performance when locating Gabor wavelet targets in noise, with fovea placement driven by a mutual information measure. The foveated approach is shown to have lower detection delay than a notional uniform resolution approach when using video that consumes equivalent bandwidth. The second experiments compare the accuracy of target position estimates from foveated and uniform resolution tracking algorithms. A technique is developed to select foveation parameters that minimize error in Kalman filter state estimates. Foveated tracking is shown to consistently outperform uniform resolution tracking on an abstract multiple target task when using video that consumes equivalent bandwidth. Performance is also compared to uniform resolution processing without bandwidth limitations. In both experiments, superior performance is achieved at a given bandwidth by foveated processing because limited resources are allocated intelligently to maximize operational performance. These findings indicate the potential for operational performance improvements over uniform resolution systems in both acquisition and tracking tasks.

  13. Incentives for Better Performance in Health Care

    PubMed Central

    Abduljawad, Asaad; Al-Assaf, Assaf F.

    2011-01-01

    Incentives for better performance in health care have several modes and methods. They are designed to motivate and encourage people to perform well and improve their outcomes. They may include monetary or non-monetary incentives and may be applied to consumers, individual providers or institutions. One such model is the Pay-for-Performance system. In this system, beneficiaries are compared with one another based on a set of performance indicators and those that achieve a high level of performance are rewarded financially. This system is meant to recognise and primarily to reward high performers. Its goal is to encourage beneficiaries to strive for better performance. This system has been applied in several countries and for several recipients and settings. Early indications show that this system has had mixed effects on performance. PMID:21969891

  14. Decision-directed detector for overlapping PCM/NRZ signals.

    NASA Technical Reports Server (NTRS)

    Wang, C. D.; Noack, T. L.

    1973-01-01

    A decision-directed (DD) technique for the detection of overlapping PCM/NRZ signals in the presence of white Gaussian noise is investigated. The performance of the DD detector is represented by probability of error Pe versus input signal-to-noise ratio (SNR). To examine how much improvement in performance can be achieved with this technique, Pe's with and without DD feedback are evaluated in parallel. Further, analytical results are compared with those found by Monte Carlo simulations. The results are in good agreement.

  15. Development of a sub-miniature rubidium oscillator for SEEKTALK application

    NASA Technical Reports Server (NTRS)

    Fruehauf, H.; Weidemann, W.; Jechart, E.

    1981-01-01

    Warm-up and size challenges to oscillator construction are presented as well as the problems involved in these tasks. The performance of M-100 military rubidium oscillator is compared to that of a subminiture rubididum oscillator (M-1000). Methods of achieving 1.5 minute warm-up are discussed as well as improvements in performance under adverse environmental conditions, including temperature, vibration, and magnetics. An attempt is made to construct an oscillator error budget under a set of arbitrary mission conditions.

  16. Effects of pupil filter patterns in line-scan focal modulation microscopy

    NASA Astrophysics Data System (ADS)

    Shen, Shuhao; Pant, Shilpa; Chen, Rui; Chen, Nanguang

    2018-03-01

    Line-scan focal modulation microscopy (LSFMM) is an emerging imaging technique that affords high imaging speed and good optical sectioning at the same time. We present a systematic investigation into optimal design of the pupil filter for LSFMM in an attempt to achieve the best performance in terms of spatial resolutions, optical sectioning, and modulation depth. Scalar diffraction theory was used to compute light propagation and distribution in the system and theoretical predictions on system performance, which were then compared with experimental results.

  17. Rigidifying Nonplanar Perylene Diimides by Ring Fusion Toward Geometry-Tunable Acceptors for High-Performance Fullerene-Free Solar Cells.

    PubMed

    Zhong, Hongliang; Wu, Chen-Hao; Li, Chang-Zhi; Carpenter, Joshua; Chueh, Chu-Chen; Chen, Jung-Yao; Ade, Harald; Jen, Alex K-Y

    2016-02-03

    Rigid fused perylene diimide (PDI) dimers bridged with heterocycles exhibit superior photovoltaic performance compared to their unfused semiflexible analogues. Changing the chalcogen atoms in the aromatic bridges gradually increases the twist angles between the two PDI planes, leading to a varied morphology in which the one bridged by thiophene achieves a balance and shows the best efficiency of 6.72%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Extracting and identifying concrete structural defects in GPR images

    NASA Astrophysics Data System (ADS)

    Ye, Qiling; Jiao, Liangbao; Liu, Chuanxin; Cao, Xuehong; Huston, Dryver; Xia, Tian

    2018-03-01

    Traditionally most GPR data interpretations are performed manually. With the advancement of computing technologies, how to automate GPR data interpretation to achieve high efficiency and accuracy has become an active research subject. In this paper, analytical characterizations of major defects in concrete structures, including delamination, air void and moisture in GPR images, are performed. In the study, the image features of different defects are compared. Algorithms are developed for defect feature extraction and identification. For validations, both simulation results and field test data are utilized.

  19. The OpenMP Implementation of NAS Parallel Benchmarks and its Performance

    NASA Technical Reports Server (NTRS)

    Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry

    1999-01-01

    As the new ccNUMA architecture became popular in recent years, parallel programming with compiler directives on these machines has evolved to accommodate new needs. In this study, we examine the effectiveness of OpenMP directives for parallelizing the NAS Parallel Benchmarks. Implementation details will be discussed and performance will be compared with the MPI implementation. We have demonstrated that OpenMP can achieve very good results for parallelization on a shared memory system, but effective use of memory and cache is very important.

  20. Pilot study: EatFit impacts sixth graders' academic performance on achievement of mathematics and english education standards.

    PubMed

    Shilts, Mical Kay; Lamp, Cathi; Horowitz, Marcel; Townsend, Marilyn S

    2009-01-01

    Investigate the impact of a nutrition education program on student academic performance as measured by achievement of education standards. Quasi-experimental crossover-controlled study. California Central Valley suburban elementary school (58% qualified for free or reduced-priced lunch). All sixth-grade students (n = 84) in the elementary school clustered in 3 classrooms. 9-lesson intervention with an emphasis on guided goal setting and driven by the Social Cognitive Theory. Multiple-choice survey assessing 5 education standards for sixth-grade mathematics and English at 3 time points: baseline (T1), 5 weeks (T2), and 10 weeks (T3). Repeated measures, paired t test, and analysis of covariance. Changes in total scores were statistically different (P < .05), with treatment scores (T3 - T2) generating more gains. The change scores for 1 English (P < .01) and 2 mathematics standards (P < .05; P < .001) were statistically greater for the treatment period (T3 - T2) compared to the control period (T2 - T1). Using standardized tests, results of this pilot study suggest that EatFit can improve academic performance measured by achievement of specific mathematics and English education standards. Nutrition educators can show school administrators and wellness committee members that this program can positively impact academic performance, concomitant to its primary objective of promoting healthful eating and physical activity.

  1. Benchmarking biology research organizations using a new, dedicated tool.

    PubMed

    van Harten, Willem H; van Bokhorst, Leonard; van Luenen, Henri G A M

    2010-02-01

    International competition forces fundamental research organizations to assess their relative performance. We present a benchmark tool for scientific research organizations where, contrary to existing models, the group leader is placed in a central position within the organization. We used it in a pilot benchmark study involving six research institutions. Our study shows that data collection and data comparison based on this new tool can be achieved. It proved possible to compare relative performance and organizational characteristics and to generate suggestions for improvement for most participants. However, strict definitions of the parameters used for the benchmark and a thorough insight into the organization of each of the benchmark partners is required to produce comparable data and draw firm conclusions.

  2. Using string invariants for prediction searching for optimal parameters

    NASA Astrophysics Data System (ADS)

    Bundzel, Marek; Kasanický, Tomáš; Pinčák, Richard

    2016-02-01

    We have developed a novel prediction method based on string invariants. The method does not require learning but a small set of parameters must be set to achieve optimal performance. We have implemented an evolutionary algorithm for the parametric optimization. We have tested the performance of the method on artificial and real world data and compared the performance to statistical methods and to a number of artificial intelligence methods. We have used data and the results of a prediction competition as a benchmark. The results show that the method performs well in single step prediction but the method's performance for multiple step prediction needs to be improved. The method works well for a wide range of parameters.

  3. Reserve Li/SOC12 Battery Safety Testing

    NASA Technical Reports Server (NTRS)

    Dils, C. T.; Garoutte, K. F.

    1984-01-01

    A reserve Lithium/Thionyl Chloride Battery concept is developed and undergoing feasibility testing in terms of performance, safety and abusive conditions. The feasibility of employing a battery of this type to replace thermal batteries in certain applications is demonstrated. Excellent performance of a Li/SOCl2 reserve battery is obtained across the temperature range from 0 C to +44 C. Performance improvement over the thermal battery usage is greater by a factor of 3 when discharge time and energy density are compared. Performance over an expanded temperature range is also possible. Safety and abusive testing is accomplished successfully on a series of five units. Further performance improvements can be achieved with regard to battery weight and volume reductions.

  4. Parsing clinical text: how good are the state-of-the-art parsers?

    PubMed

    Jiang, Min; Huang, Yang; Fan, Jung-wei; Tang, Buzhou; Denny, Josh; Xu, Hua

    2015-01-01

    Parsing, which generates a syntactic structure of a sentence (a parse tree), is a critical component of natural language processing (NLP) research in any domain including medicine. Although parsers developed in the general English domain, such as the Stanford parser, have been applied to clinical text, there are no formal evaluations and comparisons of their performance in the medical domain. In this study, we investigated the performance of three state-of-the-art parsers: the Stanford parser, the Bikel parser, and the Charniak parser, using following two datasets: (1) A Treebank containing 1,100 sentences that were randomly selected from progress notes used in the 2010 i2b2 NLP challenge and manually annotated according to a Penn Treebank based guideline; and (2) the MiPACQ Treebank, which is developed based on pathology notes and clinical notes, containing 13,091 sentences. We conducted three experiments on both datasets. First, we measured the performance of the three state-of-the-art parsers on the clinical Treebanks with their default settings. Then we re-trained the parsers using the clinical Treebanks and evaluated their performance using the 10-fold cross validation method. Finally we re-trained the parsers by combining the clinical Treebanks with the Penn Treebank. Our results showed that the original parsers achieved lower performance in clinical text (Bracketing F-measure in the range of 66.6%-70.3%) compared to general English text. After retraining on the clinical Treebank, all parsers achieved better performance, with the best performance from the Stanford parser that reached the highest Bracketing F-measure of 73.68% on progress notes and 83.72% on the MiPACQ corpus using 10-fold cross validation. When the combined clinical Treebanks and Penn Treebank was used, of the three parsers, the Charniak parser achieved the highest Bracketing F-measure of 73.53% on progress notes and the Stanford parser reached the highest F-measure of 84.15% on the MiPACQ corpus. Our study demonstrates that re-training using clinical Treebanks is critical for improving general English parsers' performance on clinical text, and combining clinical and open domain corpora might achieve optimal performance for parsing clinical text.

  5. National Performance Benchmarks for Modern Screening Digital Mammography: Update from the Breast Cancer Surveillance Consortium.

    PubMed

    Lehman, Constance D; Arao, Robert F; Sprague, Brian L; Lee, Janie M; Buist, Diana S M; Kerlikowske, Karla; Henderson, Louise M; Onega, Tracy; Tosteson, Anna N A; Rauscher, Garth H; Miglioretti, Diana L

    2017-04-01

    Purpose To establish performance benchmarks for modern screening digital mammography and assess performance trends over time in U.S. community practice. Materials and Methods This HIPAA-compliant, institutional review board-approved study measured the performance of digital screening mammography interpreted by 359 radiologists across 95 facilities in six Breast Cancer Surveillance Consortium (BCSC) registries. The study included 1 682 504 digital screening mammograms performed between 2007 and 2013 in 792 808 women. Performance measures were calculated according to the American College of Radiology Breast Imaging Reporting and Data System, 5th edition, and were compared with published benchmarks by the BCSC, the National Mammography Database, and performance recommendations by expert opinion. Benchmarks were derived from the distribution of performance metrics across radiologists and were presented as 50th (median), 10th, 25th, 75th, and 90th percentiles, with graphic presentations using smoothed curves. Results Mean screening performance measures were as follows: abnormal interpretation rate (AIR), 11.6 (95% confidence interval [CI]: 11.5, 11.6); cancers detected per 1000 screens, or cancer detection rate (CDR), 5.1 (95% CI: 5.0, 5.2); sensitivity, 86.9% (95% CI: 86.3%, 87.6%); specificity, 88.9% (95% CI: 88.8%, 88.9%); false-negative rate per 1000 screens, 0.8 (95% CI: 0.7, 0.8); positive predictive value (PPV) 1, 4.4% (95% CI: 4.3%, 4.5%); PPV2, 25.6% (95% CI: 25.1%, 26.1%); PPV3, 28.6% (95% CI: 28.0%, 29.3%); cancers stage 0 or 1, 76.9%; minimal cancers, 57.7%; and node-negative invasive cancers, 79.4%. Recommended CDRs were achieved by 92.1% of radiologists in community practice, and 97.1% achieved recommended ranges for sensitivity. Only 59.0% of radiologists achieved recommended AIRs, and only 63.0% achieved recommended levels of specificity. Conclusion The majority of radiologists in the BCSC surpass cancer detection recommendations for screening mammography; however, AIRs continue to be higher than the recommended rate for almost half of radiologists interpreting screening mammograms. © RSNA, 2016 Online supplemental material is available for this article.

  6. The correlation between achievement goals, learning strategies, and motivation in medical students.

    PubMed

    Kim, Sun; Hur, Yera; Park, Joo Hyun

    2014-03-01

    The purpose of this study is to investigate the pursuit of achievement goals in medical students and to assess the relationship between achievement goals, learning strategy, and motivation. Two hundred seventy freshman and sophomore premedical students and sophomore medical school students participated in this study, which used the Achievement Goals Scale and the Self-Regulated Learning Strategy Questionnaire. The achievement goals of medical students were oriented toward moderate performance approach levels, slightly high performance avoidance levels, and high mastery goals. About 40% of the students were high or low in all three achievement goals. The most successful adaptive learners in the areas of learning strategies, motivation, and school achievement were students from group 6, who scored high in both performance approach and mastery goals but low in performance avoidance goals. And goal achievement are related to the academic self-efficacy, learning strategies, and motivation in medical students. In the context of academic achievement, mastery goals and performance approach goals are adaptive goals.

  7. No Correlation Between Work-Hours and Operative Volumes--A Comparison Between United States and Danish Operative Volumes Achieved During Surgical Residency.

    PubMed

    Kjærgaard, Jane; Sillesen, Martin; Beier-Holgersen, Randi

    2016-01-01

    Since 2003, United States residents have been limited to an 80-hour workweek. This has prompted concerns of reduced educational quality, especially inadequate operating exposure. In contrast, the Danish surgical specialty-training program mandates a cap on working hours of 37 per week. We hypothesize that there is no direct correlation between work-hours and operative volume achieved during surgical residency. To test the hypothesis, we compare Danish and US operative volumes achieved during surgical residency training. Retrospective comparative study. The data from the US population was extracted from the Accreditation Council for Graduate Medical Education database for General Surgery residents from 2012 to 2013. For Danish residents, a questionnaire with case categories matching the Accreditation Council for Graduate Medical Education categories were sent to all Danish surgeons graduating the national surgical residency program in 2012 or 2013, 54 in total. In all, 30 graduated residents (55%) responded to the Danish survey. We found no significant differences in mean total major procedures (1002.4 vs 976.9, p = 0.28) performed during residency training, but comparing average major procedures per year, the US residents achieve significantly more (132.3 vs 195.4, p <0.01). When factoring in differences in time spent in training, this amounts to a weekly average difference of 1.2 cases throughout training. In this study, we find no difference in overall surgical volumes between Danes and US residents during their surgical training. When time in training was accounted for, differences between weekly surgical volumes achieved were minor, indicating a lack of direct correlation between weekly work-hours and operative volumes achievable. Factors other than work-hours seem to effect on operative volumes achieved during training. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  8. Error Patterns with Fraction Calculations at Fourth Grade as a Function of Students' Mathematics Achievement Status.

    PubMed

    Schumacher, Robin F; Malone, Amelia S

    2017-09-01

    The goal of the present study was to describe fraction-calculation errors among 4 th -grade students and determine whether error patterns differed as a function of problem type (addition vs. subtraction; like vs. unlike denominators), orientation (horizontal vs. vertical), or mathematics-achievement status (low- vs. average- vs. high-achieving). We specifically addressed whether mathematics-achievement status was related to students' tendency to operate with whole number bias. We extended this focus by comparing low-performing students' errors in two instructional settings that focused on two different types of fraction understandings: core instruction that focused on part-whole understanding vs. small-group tutoring that focused on magnitude understanding. Results showed students across the sample were more likely to operate with whole number bias on problems with unlike denominators. Students with low or average achievement (who only participated in core instruction) were more likely to operate with whole number bias than students with low achievement who participated in small-group tutoring. We suggest instruction should emphasize magnitude understanding to sufficiently increase fraction understanding for all students in the upper elementary grades.

  9. Rainbow net analysis of VAXcluster system availability

    NASA Technical Reports Server (NTRS)

    Johnson, Allen M., Jr.; Schoenfelder, Michael A.

    1991-01-01

    A system modeling technique, Rainbow Nets, is used to evaluate the availability and mean-time-to-interrupt of the VAXcluster. These results are compared to the exact analytic results showing that reasonable accuracy is achieved through simulation. The complexity of the Rainbow Net does not increase as the number of processors increases, but remains constant, unlike a Markov model which expands exponentially. The constancy is achieved by using tokens with identity attributes (items) that can have additional attributes associated with them (features) which can exist in multiple states. The time to perform the simulation increases, but this is a polynomial increase rather than exponential. There is no restriction on distributions used for transition firing times, allowing real situations to be modeled more accurately by choosing the distribution which best fits the system performance and eliminating the need for simplifying assumptions.

  10. Impact of beacon wavelength on phase-compensation performance

    NASA Astrophysics Data System (ADS)

    Enterline, Allison A.; Spencer, Mark F.; Burrell, Derek J.; Brennan, Terry J.

    2017-09-01

    This study evaluates the effects of beacon-wavelength mismatch on phase-compensation performance. In general, beacon-wavelength mismatch occurs at the system level because the beacon-illuminator laser (BIL) and high-energy laser (HEL) are often at different wavelengths. Such is the case, for example, when using an aperture sharing element to isolate the beam-control sensor suite from the blinding nature of the HEL. With that said, this study uses the WavePlex Toolbox in MATLAB® to model ideal spherical wave propagation through various atmospheric-turbulence conditions. To quantify phase-compensation performance, we also model a nominal adaptive-optics (AO) system. We achieve correction from a Shack-Hartmann wavefront sensor and continuous-face-sheet deformable mirror using a least-squares phase reconstruction algorithm in the Fried geometry and a leaky integrator control law. To this end, we plot the power in the bucket metric as a function of BIL-HEL wavelength difference. Our initial results show that positive BIL-HEL wavelength differences achieve better phase compensation performance compared to negative BIL-HEL wavelength differences (i.e., red BILs outperform blue BILs). This outcome is consistent with past results.

  11. Walking on a user similarity network towards personalized recommendations.

    PubMed

    Gan, Mingxin

    2014-01-01

    Personalized recommender systems have been receiving more and more attention in addressing the serious problem of information overload accompanying the rapid evolution of the world-wide-web. Although traditional collaborative filtering approaches based on similarities between users have achieved remarkable success, it has been shown that the existence of popular objects may adversely influence the correct scoring of candidate objects, which lead to unreasonable recommendation results. Meanwhile, recent advances have demonstrated that approaches based on diffusion and random walk processes exhibit superior performance over collaborative filtering methods in both the recommendation accuracy and diversity. Building on these results, we adopt three strategies (power-law adjustment, nearest neighbor, and threshold filtration) to adjust a user similarity network from user similarity scores calculated on historical data, and then propose a random walk with restart model on the constructed network to achieve personalized recommendations. We perform cross-validation experiments on two real data sets (MovieLens and Netflix) and compare the performance of our method against the existing state-of-the-art methods. Results show that our method outperforms existing methods in not only recommendation accuracy and diversity, but also retrieval performance.

  12. Performance of Point and Range Queries for In-memory Databases using Radix Trees on GPUs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alam, Maksudul; Yoginath, Srikanth B; Perumalla, Kalyan S

    In in-memory database systems augmented by hardware accelerators, accelerating the index searching operations can greatly increase the runtime performance of database queries. Recently, adaptive radix trees (ART) have been shown to provide very fast index search implementation on the CPU. Here, we focus on an accelerator-based implementation of ART. We present a detailed performance study of our GPU-based adaptive radix tree (GRT) implementation over a variety of key distributions, synthetic benchmarks, and actual keys from music and book data sets. The performance is also compared with other index-searching schemes on the GPU. GRT on modern GPUs achieves some of themore » highest rates of index searches reported in the literature. For point queries, a throughput of up to 106 million and 130 million lookups per second is achieved for sparse and dense keys, respectively. For range queries, GRT yields 600 million and 1000 million lookups per second for sparse and dense keys, respectively, on a large dataset of 64 million 32-bit keys.« less

  13. Inlet Trade Study for a Low-Boom Aircraft Demonstrator

    NASA Technical Reports Server (NTRS)

    Heath, Christopher M.; Slater, John W.; Rallabhandi, Sriram K.

    2016-01-01

    Propulsion integration for low-boom supersonic aircraft requires careful inlet selection, placement, and tailoring to achieve acceptable propulsive and aerodynamic performance, without compromising vehicle sonic boom loudness levels. In this investigation, an inward-turning streamline-traced and axisymmetric spike inlet are designed and independently installed on a conceptual low-boom supersonic demonstrator aircraft. The airframe was pre-shaped to achieve a target ground under-track loudness of 76.4 PLdB at cruise using an adjoint-based design optimization process. Aircraft and inlet performance characteristics were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Isolated cruise inlet performance including total pressure recovery and distortion were computed and compared against installed inlet performance metrics. Evaluation of vehicle near-field pressure signatures, along with under- and off-track propagated loudness levels is also reported. Results indicate the integrated axisymmetric spike design offers higher inlet pressure recovery, lower fan distortion, and reduced sonic boom. The vehicle with streamline-traced inlet exhibits lower external wave drag, which translates to a higher lift-to-drag ratio and increased range capability.

  14. A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft

    NASA Technical Reports Server (NTRS)

    Brown, S. C.; Hardy, G. H.; Hindson, W. S.

    1983-01-01

    As part of a comprehensive flight-test program of STOL operating systems for the terminal area, an automatic landing system was developed and evaluated for a light wing loading turboprop aircraft. The aircraft utilized an onboard advanced digital avionics system. Flight tests were conducted at a facility that included a STOL runway site with a microwave landing system. Longitudinal flight-test results were presented and compared with available (basically CTOL) criteria. These comparisons were augmented by results from a comprehensive simulation of the controlled aircraft which included representations of navigation errors that were encountered in flight and atmospheric disturbances. Acceptable performance on final approach and at touchdown was achieved by the autoland (automatic landing) system for the moderate winds and turbulence conditions encountered in flight. However, some touchdown performance goals were marginally achieved, and simulation results suggested that difficulties could be encountered in the presence of more extreme atmospheric conditions. Suggestions were made for improving performance under those more extreme conditions.

  15. Cartridge output testing - Methods to overcome closed-bomb shortcomings

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1991-01-01

    Although the closed-bomb test has achieved virtually universal acceptance for measuring the output performance of pyrotechnic cartridges, there are serious shortcomings in its ability to quantify the performance of cartridges used as energy sources for pyrotechnic-activated mechanical devices. This paper presents several examples of cartridges (including the NASA Standard Initiator NSI) that successfully met closed-bomb performance requirements, but resulted in functional failures in mechanisms. To resolve these failures, test methods were developed to demonstrate a functional margin, based on comparing energy required to accomplish the function to energy deliverable by the cartridge.

  16. Magnetic field configurations on thruster performance in accordance with ion beam characteristics in cylindrical Hall thruster plasmas

    NASA Astrophysics Data System (ADS)

    Kim, Holak; Choe, Wonho; Lim, Youbong; Lee, Seunghun; Park, Sanghoo

    2017-03-01

    Magnetic field configuration is critical in Hall thrusters for achieving high performance, particularly in thrust, specific impulse, efficiency, etc. Ion beam features are also significantly influenced by magnetic field configurations. In two typical magnetic field configurations (i.e., co-current and counter-current configurations) of a cylindrical Hall thruster, ion beam characteristics are compared in relation to multiply charged ions. Our study shows that the co-current configuration brings about high ion current (or low electron current), high ionization rate, and small plume angle that lead to high thruster performance.

  17. [Minimally invasive fasciotomy in the treatment of chronic exertional anterior compartment syndrome of the leg: personal technique].

    PubMed

    Bramante, Carmelo; Gandolfo, Luigi; Bosco, Vincenzo

    2008-01-01

    Numerous fasciotomy techniques have been proposed for the treatment of chronic exertional anterior compartment syndrome. In this work we evaluate the efficacy of a personal surgical technique whereby the fasciotomy is performed through a small cutaneous incision using endo mini-shears. From 2004 to 2006 19 patients, all professional skaters, were submitted to bilateral fasciotomy (38 legs). No complications were observed. Only two patients used pain-killers. In the follow-up (12 months), resumption of competitive activity was achieved by the fourth week in 63.2% of cases (12 patients), by the fifth week in 26.3% (5 patients), and by the sixth week in 10.5% (2 patients). All patients achieved sporting performance comparable to that present before the onset of symptoms. There were no recurrences. This technique is relatively simple to perform, is easily repeatable, does not require a long learning curve, is practically complication-free, and is characterised by a virtually painless postoperative course.

  18. Oocyte cryopreservation: a feasible fertility preservation option for reproductive age cancer survivors

    PubMed Central

    Labella, Patty Ann; Grifo, James; Knopman, Jaime M.

    2010-01-01

    Purpose To compare oocyte cryopreservation cycles performed in cancer patients to those of infertile women. Methods Cancer patients referred for fertility preservation underwent counseling in compliance with the ASRM; those electing oocyte cryopreservation were included. Ovarian stimulation was achieved with injectable gonadotropins and freezing was performed using slow-cooling and vitrification methods. Results Fifty cancer patients (mean age 31 y) underwent oocyte cryopreservation; adequate ovarian stimulation was achieved in 10 ± 0.3 days. The outcome from these cycles included a mean peak estradiol of 2,376 pg/ml and an average of 19 oocytes retrieved (15 mature oocytes were cryopreserved/cycle). All patients tolerated ovarian hyperstimulation. There were no significant differences noted between cryopreservation cycles performed in cancer patients and in women without malignancy. Conclusions Oocyte cryopreservation appears to be a feasible fertility preservation method for reproductive-age women diagnosed with cancer. This modality is not only effective but also, providing a multidiscipline effort, can be completed in timely fashion. PMID:20480389

  19. FDM and DMT performance comparison in high capacity point-to-point fibre links for intra/inter-datacentre connections

    NASA Astrophysics Data System (ADS)

    Gatto, A.; Parolari, P.; Boffi, P.

    2018-05-01

    Frequency division multiplexing (FDM) is attractive to achieve high capacities in multiple access networks characterized by direct modulation and direct detection. In this paper we take into account point-to-point intra- and inter-datacenter connections to understand the performance of FDM operation compared with the ones achievable with standard multiple carrier modulation approach based on discrete multitone (DMT). DMT and FDM allow to match the non-uniform and bandwidth-limited response of the system under test, associated with the employment of low-cost directly-modulated sources, such as VCSELs with high-frequency chirp, and with fibre-propagation in presence of chromatic dispersion. While for very short distances typical of intra-datacentre communications, the huge number of DMT subcarriers permits to increase the transported capacity with respect to the FDM employment, in case of few tens-km reaches typical of inter-datacentre connections, the capabilities of FDM are more evident, providing system performance similar to the case of DMT application.

  20. Solar hydrogen production with cerium oxides thermochemical cycle

    NASA Astrophysics Data System (ADS)

    Binotti, Marco; Di Marcoberardino, Gioele; Biassoni, Mauro; Manzolini, Giampaolo

    2017-06-01

    This paper discusses the hydrogen production using a solar driven thermochemical cycle. The thermochemical cycle is based on nonstoichiometric cerium oxides redox and the solar concentration system is a solar dish. Detailed optical and redox models were developed to optimize the hydrogen production performance as function of several design parameters (i.e. concentration ratio, reactor pressures and temperatures) The efficiency of the considered technology is compared against two commercially available technologies namely PV + electrolyzer and Dish Stirling + electrolyzer. Results show that solar-to-fuel efficiency of 21.2% can be achieved at design condition assuming a concentration ratio around 5000, reduction and oxidation temperatures of 1500°C and 1275 °C. When moving to annual performance, the annual yield of the considered approach can be as high as 16.7% which is about 43% higher than the best competitive technology. The higher performance implies that higher installation costs around 40% can be accepted for the innovative concept to achieve the same cost of hydrogen.

  1. Statistical Modeling and Prediction for Tourism Economy Using Dendritic Neural Network

    PubMed Central

    Yu, Ying; Wang, Yirui; Tang, Zheng

    2017-01-01

    With the impact of global internationalization, tourism economy has also been a rapid development. The increasing interest aroused by more advanced forecasting methods leads us to innovate forecasting methods. In this paper, the seasonal trend autoregressive integrated moving averages with dendritic neural network model (SA-D model) is proposed to perform the tourism demand forecasting. First, we use the seasonal trend autoregressive integrated moving averages model (SARIMA model) to exclude the long-term linear trend and then train the residual data by the dendritic neural network model and make a short-term prediction. As the result showed in this paper, the SA-D model can achieve considerably better predictive performances. In order to demonstrate the effectiveness of the SA-D model, we also use the data that other authors used in the other models and compare the results. It also proved that the SA-D model achieved good predictive performances in terms of the normalized mean square error, absolute percentage of error, and correlation coefficient. PMID:28246527

  2. MIGS-GPU: Microarray Image Gridding and Segmentation on the GPU.

    PubMed

    Katsigiannis, Stamos; Zacharia, Eleni; Maroulis, Dimitris

    2017-05-01

    Complementary DNA (cDNA) microarray is a powerful tool for simultaneously studying the expression level of thousands of genes. Nevertheless, the analysis of microarray images remains an arduous and challenging task due to the poor quality of the images that often suffer from noise, artifacts, and uneven background. In this study, the MIGS-GPU [Microarray Image Gridding and Segmentation on Graphics Processing Unit (GPU)] software for gridding and segmenting microarray images is presented. MIGS-GPU's computations are performed on the GPU by means of the compute unified device architecture (CUDA) in order to achieve fast performance and increase the utilization of available system resources. Evaluation on both real and synthetic cDNA microarray images showed that MIGS-GPU provides better performance than state-of-the-art alternatives, while the proposed GPU implementation achieves significantly lower computational times compared to the respective CPU approaches. Consequently, MIGS-GPU can be an advantageous and useful tool for biomedical laboratories, offering a user-friendly interface that requires minimum input in order to run.

  3. Statistical Modeling and Prediction for Tourism Economy Using Dendritic Neural Network.

    PubMed

    Yu, Ying; Wang, Yirui; Gao, Shangce; Tang, Zheng

    2017-01-01

    With the impact of global internationalization, tourism economy has also been a rapid development. The increasing interest aroused by more advanced forecasting methods leads us to innovate forecasting methods. In this paper, the seasonal trend autoregressive integrated moving averages with dendritic neural network model (SA-D model) is proposed to perform the tourism demand forecasting. First, we use the seasonal trend autoregressive integrated moving averages model (SARIMA model) to exclude the long-term linear trend and then train the residual data by the dendritic neural network model and make a short-term prediction. As the result showed in this paper, the SA-D model can achieve considerably better predictive performances. In order to demonstrate the effectiveness of the SA-D model, we also use the data that other authors used in the other models and compare the results. It also proved that the SA-D model achieved good predictive performances in terms of the normalized mean square error, absolute percentage of error, and correlation coefficient.

  4. Facilitation of creative performance by using blue and red accent lighting in work and learning areas.

    PubMed

    Kombeiz, Olga; Steidle, Anna

    2018-03-01

    Research has shown that colours influence motivation and cognitive performance. In achievement contexts, red evokes avoidance motivation that hinders creativity, while blue elicits an approach motivation that facilitates creativity. However, due to their position and mode of presentation, colours may convey a different message. Red accent lighting creates a cosy, friendly room atmosphere that may, even in an achievement context, elicit an approach rather than an avoidance motivation. Results (N = 146) showed that both blue and red accent light increased strategic approach motivation compared to white accent light. Moreover, through the heightened approach motivation, colourful accent light indirectly improved creative performance. Implications for future research on colour and practical implications for colour usage are discussed. Practitioner Summary: Designing work environments for creativity is a new topic in ergonomics research and practice. The present study demonstrates indirect effects of coloured accent light on creativity providing interesting possibilities for the design of workplaces for knowledge workers, classrooms and all other rooms in which people work on new ideas.

  5. Step-by-Step Heating of Dye Solution for Efficient Solar Energy Harvesting in Dye-Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Shah, Syed Afaq Ali; Sayyad, Muhammad Hassan; Abdulkarim, Salem; Qiao, Qiquan

    2018-05-01

    A step-by-step heat treatment was applied to ruthenium-based N719 dye solution for its potential application in dye-sensitized solar cells (DSSCs). The effects were analyzed and compared with standard untreated devices. A significant increase in short circuit current density was observed by employing a step-by-step heating method for dye solution in DSSCs. This increase of J sc is attributed to the enhancement in dye adsorption by the surface of the semiconductor and the higher number of charge carriers generated. DSSCs fabricated by a heated dye solution have achieved an overall power conversion efficiency of 8.41% which is significantly higher than the efficiency of 7.31% achieved with DSSCs fabricated without heated dye. Electrochemical impedance spectroscopy and capacitance voltage studies were performed to understand the better performance of the device fabricated with heated dye. Furthermore, transient photocurrent and transient photovoltage measurements were also performed to gain an insight into interfacial charge carrier recombinations.

  6. Broadband 1.2- and 2.4-mm Gallium Nitride (GaN) Power Amplifier Designs

    DTIC Science & Technology

    2017-10-01

    showing double the power of a single 1.2-mm HEMT with 55% PAE at a comparable gain compression level. 3. Summary and Conclusion A preliminary design of...combined, 2.4-mm HEMT power amplifier should achieve comparable performance based on a preliminary design using ideal, lossless matching elements. For...ARL-TR-8180 ● OCT 2017 US Army Research Laboratory Broadband 1.2- and 2.4-mm Gallium Nitride (GaN) Power Amplifier Designs by

  7. Micromachined modulator arrays for use in free-space optical communication systems

    NASA Astrophysics Data System (ADS)

    Lewis, Keith L.; Ridley, Kevin D.; McNie, Mark E.; Smith, Gilbert W.; Scott, Andrew M.

    2004-12-01

    A summary is presented of some of the design criteria relevant to the realisation of silicon micromachined modulator arrays for use in free-space optical communication systems. Theoretical performance levels achievable are compared with values measured on experimental devices produced using a modified Multi-User MEMS Process (MUMPS). Devices capable of realising modulation rates in excess of 300 kHz are described and their optical characteristics compared with published data on devices based on multiple quantum well technology.

  8. Wavefront correction performed by a deformable mirror of arbitrary actuator pattern within a multireflection waveguide.

    PubMed

    Ma, Xingkun; Huang, Lei; Bian, Qi; Gong, Mali

    2014-09-10

    The wavefront correction ability of a deformable mirror with a multireflection waveguide was investigated and compared via simulations. By dividing a conventional actuator array into a multireflection waveguide that consisted of single-actuator units, an arbitrary actuator pattern could be achieved. A stochastic parallel perturbation algorithm was proposed to find the optimal actuator pattern for a particular aberration. Compared with conventional an actuator array, the multireflection waveguide showed significant advantages in correction of higher order aberrations.

  9. Study of thermal management for space platform applications

    NASA Technical Reports Server (NTRS)

    Oren, J. A.

    1980-01-01

    Techniques for the management of the thermal energy of large space platforms using many hundreds of kilowatts over a 10 year life span were evaluated. Concepts for heat rejection, heat transport within the vehicle, and interfacing were analyzed and compared. The heat rejection systems were parametrically weight optimized over conditions for heat pipe and pumped fluid approaches. Two approaches to achieve reliability were compared for: performance, weight, volume, projected area, reliability, cost, and operational characteristics. Technology needs are assessed and technology advancement recommendations are made.

  10. Energy performance of building fabric - Comparing two types of vernacular residential houses

    NASA Astrophysics Data System (ADS)

    Draganova, Vanya Y.; Matsumoto, Hiroshi; Tsuzuki, Kazuyo

    2017-10-01

    Notwithstanding apparent differences, Japanese and Bulgarian traditional residential houses share a lot of common features - building materials, building techniques, even layout design. Despite the similarities, these two types of houses have not been compared so far. The study initiates such comparison. The focus is on houses in areas with similar climate in both countries. Current legislation requirements are compared, as well as the criteria for thermal comfort of people. Achieving high energy performance results from a dynamic system of 4 main key factors - thermal comfort range, heating/cooling source, building envelope and climatic conditions. A change in any single one of them can affect the final energy performance. However, it can be expected that a combination of changes in more than one factor usually occurs. The aim of this study is to evaluate the correlation between the thermal performance of building envelope designed under current regulations and a traditional one, having in mind the different thermal comfort range in the two countries. A sample building model is calculated in Scenario 1 - Japanese traditional building fabric, Scenario 2 - Bulgarian traditional building fabric and Scenario 3 - meeting the requirements of the more demanding current regulations. The energy modelling is conducted using EnergyPlus through OpenStudio cross-platform of software tools. The 3D geometry for the simulation is created using OpenStudio SketchUp Plug-in. Equal number of inhabitants, electricity consumption and natural ventilation is assumed. The results show that overall low energy consumption can be achieved using traditional building fabric as well, when paired with a wider thermal comfort range. Under these conditions traditional building design is still viable today. This knowledge can reestablish the use of traditional building fabric in contemporary design, stimulate preservation of local culture, building traditions and community identity.

  11. Estimates of premorbid ability in a neurodegenerative disease clinic population: comparing the Test of Premorbid Functioning and the Wide Range Achievement Test, 4th Edition.

    PubMed

    Berg, Jody-Lynn; Durant, January; Banks, Sarah J; Miller, Justin B

    2016-05-01

    Two frequently used measures to assess premorbid intellectual ability include the Wide Range Achievement Test, 4th Edition Reading Subtest (WRAT-4 READ) and the Test of Premorbid Functioning (TOPF). The present study compared estimates obtained from these measures in a neurodegenerative disease population. Records from 85 referrals seen for neuropsychological evaluation in a neurodegenerative disorders clinic were reviewed. Evaluations included TOPF, WRAT-4 READ, and measures of memory, reasoning, language, and executive functioning. Pairwise correlations and concordance correlation coefficients (CCC) were calculated between raw scores and predicted intelligence estimates. Discrepancy scores were calculated between estimates and data were divided into three groups based on size of standardized discrepancy score: Equal, WRAT-4 READ > TOPF, and TOPF > WRAT-4 READ. analysis of variances compared groups on demographic characteristics and cognitive performance. Despite strong Pearson correlation, CCC between predicted IQ estimates showed poor agreement between measures, with evidence of both fixed and proportional bias. Discrepancies ranged from -24.0 to 22.0 (M = 1.78, SD = 6.65), with TOPF generating higher estimates on average. Individuals performing better on WRAT-4 READ were significantly older (M age = 76.26, SD = 7.53) than those performing similarly on both measures and those performing better on TOPF (F (2, 82) = 7.31, p < .001). All other comparisons between groups on demographic variables and cognitive measures were non-significant. Estimates of premorbid intelligence obtained from the TOPF and WRAT-4 READ have a strong linear relationship, but systematically generate inconsistent estimates in a neurodegenerative disease clinical sample and should not be used interchangeably.

  12. Obese adolescents with type 2 diabetes perform worse than controls on cognitive and behavioral assessments.

    PubMed

    Brady, Cassandra C; Vannest, Jennifer J; Dolan, Lawrence M; Kadis, Darren S; Lee, Gregory R; Holland, Scott K; Khoury, Jane C; Shah, Amy S

    2017-06-01

    Children with type 1 diabetes demonstrate worse cognitive performance compared with their peers. Little is known regarding the cognitive and behavioral performance in obese adolescents with type 2 diabetes. Cross sectional evaluation of 20 obese adolescents with type 2 diabetes and 20 healthy adolescents was performed in Cincinnati, Ohio. Cognitive tests that included measures of processing speed, working memory, verbal and semantic fluency and parent reports of executive function and problem behavior were compared. Academic achievement and the relationship between cognitive/behavioral scores and diabetes duration and diabetes control (hemoglobin A1c) were assessed in the type 2 diabetes group only. The type 2 diabetes group had mean duration of diabetes of 2.8 ± 2.2 yr and hemoglobin A1c of 7.9 ± 2.2%. Adolescents with type 2 diabetes scored lower than controls on tests of working and verbal memory and processing speed (all p < 0.05) and worse for Internalizing, Externalizing, and Total Problems behaviors on the Child Behavior Checklist (all p < 0.05). Adolescents with type 2 diabetes scored below the population mean in academic achievement, most notably calculation. Working memory and processing speed were negatively correlated with duration of diabetes (r = -0.50 and -0.47, respectively, p < 0.05). Obese youth with type 2 diabetes score poorly compared with controls on multiple assessments of cognitive function and adaptive behavior. Further work is needed to determine if these effects are driven by obesity, diabetes or other demographic and socioeconomic risk factors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Comparative performance of precommercial cellulases hydrolyzing pretreated corn stover

    PubMed Central

    2011-01-01

    Background Cellulases and related hydrolytic enzymes represent a key cost factor for biochemical conversion of cellulosic biomass feedstocks to sugars for biofuels and chemicals production. The US Department of Energy (DOE) is cost sharing projects to decrease the cost of enzymes for biomass saccharification. The performance of benchmark cellulase preparations produced by Danisco, DSM, Novozymes and Verenium to convert pretreated corn stover (PCS) cellulose to glucose was evaluated under common experimental conditions and is reported here in a non-attributed manner. Results Two hydrolysis modes were examined, enzymatic hydrolysis (EH) of PCS whole slurry or washed PCS solids at pH 5 and 50°C, and simultaneous saccharification and fermentation (SSF) of washed PCS solids at pH 5 and 38°C. Enzymes were dosed on a total protein mass basis, with protein quantified using both the bicinchoninic acid (BCA) assay and the Bradford assay. Substantial differences were observed in absolute cellulose to glucose conversion performance levels under the conditions tested. Higher cellulose conversion yields were obtained using washed solids compared to whole slurry, and estimated enzyme protein dosages required to achieve a particular cellulose conversion to glucose yield were extremely dependent on the protein assay used. All four enzyme systems achieved glucose yields of 90% of theoretical or higher in SSF mode. Glucose yields were reduced in EH mode, with all enzymes achieving glucose yields of at least 85% of theoretical on washed PCS solids and 75% in PCS whole slurry. One of the enzyme systems ('enzyme B') exhibited the best overall performance. However in attaining high conversion yields at lower total enzyme protein loadings, the relative and rank ordered performance of the enzyme systems varied significantly depending upon which hydrolysis mode and protein assay were used as the basis for comparison. Conclusions This study provides extensive information about the performance of four precommercial cellulase preparations. Though test conditions were not necessarily optimal for some of the enzymes, all were able to effectively saccharify PCS cellulose. Large differences in the estimated enzyme dosage requirements depending on the assay used to measure protein concentration highlight the need for better consensus methods to quantify enzyme protein. PMID:21899748

  14. Use of volumetric features for temporal comparison of mass lesions in full field digital mammograms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bozek, Jelena, E-mail: jelena.bozek@fer.hr; Grgic, Mislav; Kallenberg, Michiel

    2014-02-15

    Purpose: Temporal comparison of lesions might improve classification between benign and malignant lesions in full-field digital mammograms (FFDM). The authors compare the use of volumetric features for lesion classification, which are computed from dense tissue thickness maps, to the use of mammographic lesion area. Use of dense tissue thickness maps for lesion characterization is advantageous, since it results in lesion features that are invariant to acquisition parameters. Methods: The dataset used in the analysis consisted of 60 temporal mammogram pairs comprising 120 mediolateral oblique or craniocaudal views with a total of 65 lesions, of which 41 were benign and 24more » malignant. The authors analyzed the performance of four volumetric features, area, and four other commonly used features obtained from temporal mammogram pairs, current mammograms, and prior mammograms. The authors evaluated the individual performance of all features and of different feature sets. The authors used linear discriminant analysis with leave-one-out cross validation to classify different feature sets. Results: Volumetric features from temporal mammogram pairs achieved the best individual performance, as measured by the area under the receiver operating characteristic curve (A{sub z} value). Volume change (A{sub z} = 0.88) achieved higher A{sub z} value than projected lesion area change (A{sub z} = 0.78) in the temporal comparison of lesions. Best performance was achieved with a set that consisted of a set of features extracted from the current exam combined with four volumetric features representing changes with respect to the prior mammogram (A{sub z} = 0.90). This was significantly better (p = 0.005) than the performance obtained using features from the current exam only (A{sub z} = 0.77). Conclusions: Volumetric features from temporal mammogram pairs combined with features from the single exam significantly improve discrimination of benign and malignant lesions in FFDM mammograms compared to using only single exam features. In the comparison with prior mammograms, use of volumetric change may lead to better performance than use of lesion area change.« less

  15. Field emission properties of SiO2-wrapped CNT field emitter.

    PubMed

    Lim, Yu Dian; Hu, Liangxing; Xia, Xin; Ali, Zishan; Wang, Shaomeng; Tay, Beng Kang; Aditya, Sheel; Miao, Jianmin

    2018-01-05

    Carbon nanotubes (CNTs) exhibit unstable field emission (FE) behavior with low reliability due to uneven heights of as-grown CNTs. It has been reported that a mechanically polished SiO 2 -wrapped CNT field emitter gives consistent FE performance due to its uniform CNT heights. However, there are still a lack of studies on the comparison between the FE properties of freestanding and SiO 2 -wrapped CNTs. In this study, we have performed a comparative study on the FE properties of freestanding and SiO 2 -wrapped CNT field emitters. From the FE measurements, freestanding CNT field emitter requires lower applied voltage of 5.5 V μm -1 to achieve FE current density of 22 mA cm -2 ; whereas SiO 2 -wrapped field emitter requires 8.5 V μm -1 to achieve the same current density. This can be attributed to the lower CNT tip electric field of CNTs embedded in SiO 2 , as obtained from the electric field simulation. Nevertheless, SiO 2 -wrapped CNTs show higher consistency in FE current than freestanding CNTs. Under repeated FE measurement, SiO 2 -wrapped CNT field emitter achieves consistent FE behavior from the 1st voltage sweep, whereas freestanding field emitter only achieved consistent FE performance after 3rd voltage sweep. At the same time, SiO 2 -wrapped CNTs exhibit better emission stability than freestanding CNTs over 4000 s continuous emission.

  16. Field emission properties of SiO2-wrapped CNT field emitter

    NASA Astrophysics Data System (ADS)

    Lim, Yu Dian; Hu, Liangxing; Xia, Xin; Ali, Zishan; Wang, Shaomeng; Tay, Beng Kang; Aditya, Sheel; Miao, Jianmin

    2018-01-01

    Carbon nanotubes (CNTs) exhibit unstable field emission (FE) behavior with low reliability due to uneven heights of as-grown CNTs. It has been reported that a mechanically polished SiO2-wrapped CNT field emitter gives consistent FE performance due to its uniform CNT heights. However, there are still a lack of studies on the comparison between the FE properties of freestanding and SiO2-wrapped CNTs. In this study, we have performed a comparative study on the FE properties of freestanding and SiO2-wrapped CNT field emitters. From the FE measurements, freestanding CNT field emitter requires lower applied voltage of 5.5 V μm-1 to achieve FE current density of 22 mA cm-2 whereas SiO2-wrapped field emitter requires 8.5 V μm-1 to achieve the same current density. This can be attributed to the lower CNT tip electric field of CNTs embedded in SiO2, as obtained from the electric field simulation. Nevertheless, SiO2-wrapped CNTs show higher consistency in FE current than freestanding CNTs. Under repeated FE measurement, SiO2-wrapped CNT field emitter achieves consistent FE behavior from the 1st voltage sweep, whereas freestanding field emitter only achieved consistent FE performance after 3rd voltage sweep. At the same time, SiO2-wrapped CNTs exhibit better emission stability than freestanding CNTs over 4000 s continuous emission.

  17. Educational Tracking, Inequality and Performance: New Evidence from a Differences-in-Differences Technique

    ERIC Educational Resources Information Center

    Lavrijsen, Jeroen; Nicaise, Ides

    2016-01-01

    One of the important differences between educational systems from different countries is the age at which students are placed into separate tracks. We examined the effects of the age at which tracking occurred on student achievement in a comparative perspective, making use of recent waves of three internationally standardized student assessments…

  18. A Causal-Comparative Analysis of the Effects of a Student Support Team (SST) Intervention Model at a Secondary School

    ERIC Educational Resources Information Center

    Johnson, Mid D.

    2010-01-01

    The purpose of this research was to identify and examine the effectiveness of a "Student Support Team" (SST) intervention model designed to increase the performance of struggling secondary students and to help them achieve prescribed state standards on the mathematics "Texas Assessment of Knowledge and Skills (TAKS)"…

  19. Strengthening Academic Vocabulary with Word Generation® Helps Sixth-Grade Students Improve Reading Comprehension

    ERIC Educational Resources Information Center

    Mokhtari, Kouider; Velten, Justin

    2015-01-01

    In this quasi-experimental study, we assessed the promise of Word Generation, a research-based academic vocabulary program, on improving the reading achievement outcomes of struggling sixth-grade readers in an after-school small group instructional setting. After 34 hours of academic vocabulary instruction, we compared the performance of a…

  20. Title I Schools: The Student-Based Impact of Online, On-Demand Professional Development on Educators

    ERIC Educational Resources Information Center

    Shaha, Steven; Glassett, Kelly; Copas, Aimee; Ellsworth, Heather

    2015-01-01

    Title I students remain among the most challenging population for achieving significant gains in academic performance and standardized test scores. This multi-state, quasi-experimental, pre-versus-post study reflects the comparative Title I gains for math and reading scores for teachers participating in an online, on-demand professional…

  1. Training and Psychosocial Patterns during the Early Development of Portuguese National Team Athletes

    ERIC Educational Resources Information Center

    Barreiros, Andre; Cote, Jean; Fonseca, Antonio Manuel

    2013-01-01

    This study explored the early development of expert athletes compared to a group of athletes that did not achieve an expert level of performance despite being involved in youth events with their national squads. In particular, the activities, training patterns, and psychosocial influences that characterized their paths in competitive sports were…

  2. A Comparative Study of Instructor and Student-Led Learning in a Large Nonmajors Biology Course: Student Performance and Perceptions

    ERIC Educational Resources Information Center

    Bernot, Melody J.; Metzler, Jennifer

    2014-01-01

    Traditional lectures have come under increasing criticism as research indicates lectures may be less effective in achieving learning outcomes than other teaching methods. Student engagement and success can potentially be improved by changing traditional lectures to instructional methods using active learning techniques. Active learning refers to…

  3. The Cost-Effectiveness of Replacing the Bottom Quartile of Novice Teachers through Value-Added Teacher Assessment

    ERIC Educational Resources Information Center

    Yeh, Stuart S.; Ritter, Joseph

    2009-01-01

    A cost-effectiveness analysis was conducted of Gordon, Kane, and Staiger's (2006) proposal to raise student achievement by identifying and replacing the bottom quartile of novice teachers, using value-added assessment of teacher performance. The cost effectiveness of this proposal was compared to the cost effectiveness of voucher programs, charter…

  4. Beating the Odds: Finding Schools Exceeding Achievement Expectations with High-Risk Students. Summary. REL 2014-032

    ERIC Educational Resources Information Center

    Koon, Sharon; Petscher, Yaacov; Foorman, Barbara R.

    2014-01-01

    State education leaders are often interested in identifying schools that have demonstrated success with improving the literacy of students who are at the highest level of risk for reading difficulties. The identification of these schools that are "beating the odds" is typically accomplished by comparing a school's observed performance on…

  5. Beating the Odds: Finding Schools Exceeding Achievement Expectations with High-Risk Students. REL 2014-032

    ERIC Educational Resources Information Center

    Koon, Sharon; Petscher, Yaacov; Foorman, Barbara R.

    2014-01-01

    State education leaders are often interested in identifying schools that have demonstrated success with improving the literacy of students who are at the highest level of risk for reading difficulties. The identification of these schools that are "beating the odds" is typically accomplished by comparing a school's observed performance on…

  6. B-52 control configured vehicles: Flight test results

    NASA Technical Reports Server (NTRS)

    Arnold, J. I.; Murphy, F. B.

    1976-01-01

    Recently completed B-52 Control Configured Vehicles (CCV) flight testing is summarized, and results are compared to analytical predictions. Results are presented for five CCV system concepts: ride control, maneuver load control, flutter mode control, augmented stability, and fatigue reduction. Test results confirm analytical predictions and show that CCV system concepts achieve performance goals when operated individually or collectively.

  7. Sex Differences in Processing Speed: Developmental Effects in Males and Females

    ERIC Educational Resources Information Center

    Camarata, Stephen; Woodcock, Richard

    2006-01-01

    The purpose of this study was to compare the cognitive abilities and selected achievement performance of females and males across the lifespan on standardization samples of broad cognitive abilities in 1987 participants (1102 females, 885 males) from the WJ III, 4253 participants (2014 males, 2239 females) from the WJ-R, and 4225 participants…

  8. Administrative Leadership in Three Small, Private Tennessee Colleges: Working Groups, Real Teams, or Both?

    ERIC Educational Resources Information Center

    Nichols, Michael E.

    2010-01-01

    Diversity of knowledge and multiple perspectives are characteristic advantages of group leadership as compared to transactional or bureaucratic forms of leadership. When groups are engaged in administrative functions, they are more likely to realize a higher level of performance and more relevant and innovative solutions than may be achieved by a…

  9. Reactivity to Stress and the Cognitive Components of Math Disability in Grade 1 Children

    ERIC Educational Resources Information Center

    MacKinnon McQuarrie, Maureen A.; Siegel, Linda S.; Perry, Nancy E.; Weinberg, Joanne

    2014-01-01

    This study investigated the relationship among working memory, processing speed, math performance, and reactivity to stress in 83 Grade 1 children. Specifically, 39 children with math disability (MD) were compared to 44 children who are typically achieving (TA) in mathematics. It is the first study to use a physiological index of stress (salivary…

  10. Comparing Children's Performance on and Preference for a Number-Line Estimation Task: Tablet versus Paper and Pencil

    ERIC Educational Resources Information Center

    Piatt, Carley; Coret, Marian; Choi, Michael; Volden, Joanne; Bisanz, Jeffrey

    2016-01-01

    Tablet computers (tablets) are positioned to be powerful, innovative, effective, and motivating research and assessment tools. We addressed two questions critical for evaluating the appropriateness of using tablets to study number-line estimation, a skill associated with math achievement and argued to be central to numerical cognition. First, is…

  11. Effectiveness of Just in Time Teaching on Student Achievement in an Introductory Thermodynamics Course

    ERIC Educational Resources Information Center

    Liberatore, Matthew W.; Morrish, Rachel M.; Vestal, Charles R.

    2017-01-01

    The utility of Just-In-Time-Teaching (JITT) is compared across course topics and groups of students not receiving JITT exercises in class. JITT feedback incorporated various active learning exercises based on students' performance on online homework problems from Sapling Learning. With over 200 students in two sections participating in the…

  12. The Effects of a Developmentally Appropriate Music and Movement Program on Motor Performance

    ERIC Educational Resources Information Center

    Zachopoulou, E.; Tsapakidou, A.; Derri, V.

    2004-01-01

    Basic motor skills development is achieved through the implementation of different types of physical education programs. The purpose of this study was to investigate and to compare the effect of a developmentally appropriate music and movement program and of a developmentally appropriate physical education program on the development of jumping and…

  13. Using Separate Answer Sheets with Grade 3 Students

    ERIC Educational Resources Information Center

    Brooks, Thomas; O'Malley, Kimberly; Ragland, Shelley; Young, Michael; Kirkpatrick, Rob

    2014-01-01

    The authors compared the performance of third-grade students testing on answer sheets with those testing on machine-scored test booklets. The 1,832 students in the nationally representative sample were assigned at the campus level to complete the Stanford Achievement Test Series, Tenth Edition in 1 of 4 conditions: (a) Form A answer sheet, (b)…

  14. The Effects of Two Semesters of Secondary School Calculus on Students' First and Second Quarter Calculus Grades at the University of Utah

    ERIC Educational Resources Information Center

    Robinson, William Baker

    1970-01-01

    The predicted and actual achievement in college calculus is compared for students who had studied two semesters of calculus in high school. The regression equation used for prediction was calculated from the performance data of similar students who had not had high school calculus. (CT)

  15. Educational Effectiveness in Chilean Secondary Education: Comparing Different "Value Added" Approaches to Evaluate Schools

    ERIC Educational Resources Information Center

    Muñoz-Chereau, B.; Thomas, S. M.

    2016-01-01

    This article reports an original investigation into school performance measures and the multilevel nature of pupil achievement data in the Chilean school system using a sample of 177,461 students, nested within 7146 classrooms, 2283 secondary schools and 313 municipalities. The data-set comprised Year 10 students' 2006 SIMCE test's results in two…

  16. The Impact of School Design on Academic Achievement in the Palestinian Territories: An Empirical Study

    ERIC Educational Resources Information Center

    Matar, Mohammed; Brighith, Imad

    2010-01-01

    This article outlines a research project that aimed to gather first-hand data from school users (pupils, teachers, school principals), as well as academic performance data from pupils. The project compared data obtained from users of "new and site-specific" and "standard" schools in order to show whether more attractive and…

  17. The Impact of Supplemental Instruction on Low-Achieving Adolescents' Reading Engagement

    ERIC Educational Resources Information Center

    Cantrell, Susan Chambers; Almasi, Janice F.; Rintamaa, Margaret; Carter, Janis C.; Pennington, Jessica; Buckman, D. Matt

    2014-01-01

    The authors examined the impact of a supplemental reading course on 462 sixth-grade students' reading engagement and performance as compared with 389 students in a control group. They further explored students' cognitive strategy use through think aloud processes with a subset of students who participated in the intervention.…

  18. Does a Wii-based exercise program enhance balance control of independently functioning older adults? A systematic review.

    PubMed

    Laufer, Yocheved; Dar, Gali; Kodesh, Einat

    2014-01-01

    Exercise programs that challenge an individual's balance have been shown to reduce the risk of falls among older adults. Virtual reality computer-based technology that provides the user with opportunities to interact with virtual objects is used extensively for entertainment. There is a growing interest in the potential of virtual reality-based interventions for balance training in older adults. This work comprises a systematic review of the literature to determine the effects of intervention programs utilizing the Nintendo Wii console on balance control and functional performance in independently functioning older adults. STUDIES WERE OBTAINED BY SEARCHING THE FOLLOWING DATABASES: PubMed, CINAHL, PEDro, EMBASE, SPORTdiscus, and Google Scholar, followed by a hand search of bibliographic references of the included studies. Included were randomized controlled trials written in English in which Nintendo Wii Fit was used to enhance standing balance performance in older adults and compared with an alternative exercise treatment, placebo, or no treatment. Seven relevant studies were retrieved. The four studies examining the effect of Wii-based exercise compared with no exercise reported positive effects on at least one outcome measure related to balance performance in older adults. Studies comparing Wii-based training with alternative exercise programs generally indicated that the balance improvements achieved by Wii-based training are comparable with those achieved by other exercise programs. The review indicates that Wii-based exercise programs may serve as an alternative to more conventional forms of exercise aimed at improving balance control. However, due to the great variability between studies in terms of the intervention protocols and outcome measures, as well as methodological limitations, definitive recommendations as to optimal treatment protocols and the potential of such an intervention as a safe and effective home-based treatment cannot be made at this point.

  19. Visual training improves underwater vision in children.

    PubMed

    Gislén, Anna; Warrant, Eric J; Dacke, Marie; Kröger, Ronald H H

    2006-10-01

    Children in a tribe of sea-gypsies from South-East Asia have been found to have superior underwater vision compared to European children. In this study, we show that the improved underwater vision of these Moken children is not due to better contrast sensitivity in general. We also show that European children can achieve the same underwater acuity as the Moken children. After 1 month of underwater training (11 sessions) followed by 4 months with no underwater activities, European children showed improved underwater vision and distinct bursts of pupil constriction. When tested 8 months after the last training session in an outdoor pool in bright sunlight-comparable to light environments in South-East Asia-the children had attained the same underwater acuity as the sea-gypsy children. The achieved performance can be explained by the combined effect of pupil constriction and strong accommodation.

  20. A Distributed Signature Detection Method for Detecting Intrusions in Sensor Systems

    PubMed Central

    Kim, Ilkyu; Oh, Doohwan; Yoon, Myung Kuk; Yi, Kyueun; Ro, Won Woo

    2013-01-01

    Sensor nodes in wireless sensor networks are easily exposed to open and unprotected regions. A security solution is strongly recommended to prevent networks against malicious attacks. Although many intrusion detection systems have been developed, most systems are difficult to implement for the sensor nodes owing to limited computation resources. To address this problem, we develop a novel distributed network intrusion detection system based on the Wu–Manber algorithm. In the proposed system, the algorithm is divided into two steps; the first step is dedicated to a sensor node, and the second step is assigned to a base station. In addition, the first step is modified to achieve efficient performance under limited computation resources. We conduct evaluations with random string sets and actual intrusion signatures to show the performance improvement of the proposed method. The proposed method achieves a speedup factor of 25.96 and reduces 43.94% of packet transmissions to the base station compared with the previously proposed method. The system achieves efficient utilization of the sensor nodes and provides a structural basis of cooperative systems among the sensors. PMID:23529146

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