Quality Rating and Improvement System (QRIS) Validation Study Designs. CEELO FastFacts

ERIC Educational Resources Information Center

Schilder, D.

2013-01-01

In this "Fast Facts," a state has received Race to the Top Early Learning Challenge funds and is seeking information to inform the design of the Quality Rating and Improvement System (QRIS) validation study. The Center on Enhancing Early Learning Outcomes (CEELO) responds that according to Resnick (2012), validation of a QRIS is an…

An ergonomic approach to design hand tool for agricultural production.

PubMed

Khidiya, Mahendra Singh; Bhardwaj, Awadhesh

2012-01-01

Hand tool mechanisms designed to reduce the risk factors have rarely been studied. In this paper it is analyze trowel firstly designing in CATIA and then its Finite Element Analysis has been carried out by ABAQUS. The main emphasis is on finding stresses by using this software, then removing them by suitable mechanical working on tool & ergonomic change in the design of handle to make it more comfortable. Body part discomfort score and overall discomfort rating experienced by the subjects had also been estimated. During the muscular activity workers physiological responses i.e. energy expenditure rate, oxygen consumption rate and heart rate increases. This increase in physiological responses is related to the type, intensity and duration of work and thus sets limits to the performance of heavy work. In this paper oxygen consumption rate and heart rate was used for physiological cost estimation. These parameters were measured by Computerized Ambulatory Metabolic Measurement System K4b2.

Systematic review of communication partner training in aphasia: methodological quality.

PubMed

Cherney, Leora R; Simmons-Mackie, Nina; Raymer, Anastasia; Armstrong, Elizabeth; Holland, Audrey

2013-10-01

Twenty-three studies identified from a previous systematic review examining the effects of communication partner training on persons with aphasia and their communication partners were evaluated for methodological quality. Two reviewers rated the studies on defined methodological quality criteria relevant to each study design. There were 11 group studies, seven single-subject participant design studies, and five qualitative studies. Quality scores were derived for each study. The mean inter-rater reliability of scores for each study design ranged from 85-93%, with Cohen's Kappa indicating substantial agreement between raters. Methodological quality of research on communication partner training in aphasia was highly varied. Overall, group studies employed the least rigorous methodology as compared to single subject and qualitative research. Only two of 11 group studies complied with more than half of the quality criteria. No group studies reported therapist blinding and only one group study reported participant blinding. Across all types of studies, the criterion of treatment fidelity was most commonly omitted. Failure to explicitly report certain methodological quality criteria may account for low ratings. Using methodological rating scales specific to the type of study design may help improve the methodological quality of aphasia treatment studies, including those on communication partner training.

A Trigger-based Design for Evaluating the Safety of In Utero Antiretroviral Exposure in Uninfected Children of Human Immunodeficiency Virus-Infected Mothers

PubMed Central

Williams, Paige L.; Seage, George R.; Van Dyke, Russell B.; Siberry, George K.; Griner, Raymond; Tassiopoulos, Katherine; Yildirim, Cenk; Read, Jennifer S.; Huo, Yanling; Hazra, Rohan; Jacobson, Denise L.; Mofenson, Lynne M.; Rich, Kenneth

2012-01-01

The Pediatric HIV/AIDS Cohort Study’s Surveillance Monitoring of ART Toxicities Study is a prospective cohort study conducted at 22 US sites between 2007 and 2011 that was designed to evaluate the safety of in utero antiretroviral drug exposure in children not infected with human immunodeficiency virus who were born to mothers who were infected. This ongoing study uses a “trigger-based” design; that is, initial assessments are conducted on all children, and only those meeting certain thresholds or “triggers” undergo more intensive evaluations to determine whether they have had an adverse event (AE). The authors present the estimated rates of AEs for each domain of interest in the Surveillance Monitoring of ART Toxicities Study. They also evaluated the efficiency of this trigger-based design for estimating AE rates and for testing associations between in utero exposures to antiretroviral drugs and AEs. The authors demonstrate that estimated AE rates from the trigger-based design are unbiased after correction for the sensitivity of the trigger for identifying AEs. Even without correcting for bias based on trigger sensitivity, the trigger approach is generally more efficient for estimating AE rates than is evaluating a random sample of the same size. Minor losses in efficiency when comparing AE rates between persons exposed and unexposed in utero to particular antiretroviral drugs or drug classes were observed under most scenarios. PMID:22491086

Estimating Causal Effects of Education Interventions Using a Two-Rating Regression Discontinuity Design: Lessons from a Simulation Study and an Application

ERIC Educational Resources Information Center

Porter, Kristin E.; Reardon, Sean F.; Unlu, Fatih; Bloom, Howard S.; Cimpian, Joseph R.

2017-01-01

A valuable extension of the single-rating regression discontinuity design (RDD) is a multiple-rating RDD (MRRDD). To date, four main methods have been used to estimate average treatment effects at the multiple treatment frontiers of an MRRDD: the "surface" method, the "frontier" method, the "binding-score" method, and…

High-Impact Aerobic and Zumba Fitness on Increasing VO2MAX, Heart Rate Recovery and Skinfold Thickness

NASA Astrophysics Data System (ADS)

Suminar, T. J.; Kusnanik, N. W.; Wiriawan, O.

2018-01-01

Purpose of this study is to determine the significant effect of high-impact aerobics exercise, and Zumba fitness on increasing VO2Max, decreasing of heart rate recovery, and decreasing of skinfold thickness. A sample of this study is 30 members aerobics of student activity unit. Type of this study was quantitative by using a quasi-experimental design method. The design of this study used Matching-Only Design. Data were Analyzed by using the t test (paired t-test). The samples divided into three groups consisted of experimental group I, experimental group II, and control group. They were given a treatment for 8 weeks or 24 meeting. For the data, retrieval is done by MFT test, heart rate recovery test, and skinfold thickness test. Furthermore, the result was analyzed by using SPSS 21 series. In conclusion, significant effect of high-impact aerobics and Zumba fitness on increasing VO2Max, heart rate recovery, skinfold thickness.

Control group design, contamination and drop-out in exercise oncology trials: a systematic review.

PubMed

Steins Bisschop, Charlotte N; Courneya, Kerry S; Velthuis, Miranda J; Monninkhof, Evelyn M; Jones, Lee W; Friedenreich, Christine; van der Wall, Elsken; Peeters, Petra H M; May, Anne M

2015-01-01

Important considerations for exercise trials in cancer patients are contamination and differential drop-out among the control group members that might jeopardize the internal validity. This systematic review provides an overview of different control groups design characteristics of exercise-oncology trials and explores the association with contamination and drop-out rates. Randomized controlled exercise-oncology trials from two Cochrane reviews were included. Additionally, a computer-aided search using Medline (Pubmed), Embase and CINAHL was conducted after completion date of the Cochrane reviews. Eligible studies were classified according to three control group design characteristics: the exercise instruction given to controls before start of the study (exercise allowed or not); and the intervention the control group was offered during (any (e.g., education sessions or telephone contacts) or none) or after (any (e.g., cross-over or exercise instruction) or none) the intervention period. Contamination (yes or no) and excess drop-out rates (i.e., drop-out rate of the control group minus the drop-out rate exercise group) were described according to the three design characteristics of the control group and according to the combinations of these three characteristics; so we additionally made subgroups based on combinations of type and timing of instructions received. 40 exercise-oncology trials were included based on pre-specified eligibility criteria. The lowest contamination (7.1% of studies) and low drop-out rates (excess drop-out rate -4.7±9.2) were found in control groups offered an intervention after the intervention period. When control groups were offered an intervention both during and after the intervention period, contamination (0%) and excess drop-out rates (-10.0±12.8%) were even lower. Control groups receiving an intervention during and after the study intervention period have lower contamination and drop-out rates. The present findings can be considered when designing future exercise-oncology trials.

Tracking and data relay satellite system configuration and tradeoff study, part 1. Volume 1: Summary volume

NASA Technical Reports Server (NTRS)

1972-01-01

Study efforts directed at defining all TDRS system elements are summarized. Emphasis was placed on synthesis of a space segment design optimized to support low and medium data rate user spacecraft and launched with Delta 2914. A preliminary design of the satellite was developed and conceptual designs of the user spacecraft terminal and TDRS ground station were defined. As a result of the analyses and design effort it was determined that (1) a 3-axis-stabilized tracking and data relay satellite launched on a Delta 2914 provides telecommunications services considerably in excess of that required by the study statement; and (2) the design concept supports the needs of the space shuttle and has sufficient growth potential and flexibility to provide telecommunications services to high data rate users. Recommendations for further study are included.

Dynamic Characteristics of The DSI-Type Constant-Flow Valves

NASA Astrophysics Data System (ADS)

Kang, Yuan; Hu, Sheng-Yan; Chou, Hsien-Chin; Lee, Hsing-Han

Constant flow valves have been presented in industrial applications or academic studies, which compensate recess pressures of a hydrostatic bearing to resist load fluctuating. The flow rate of constant-flow valves can be constant in spite of the pressure changes in recesses, however the design parameters must be specified. This paper analyzes the dynamic responses of DSI-type constant-flow valves that is designed as double pistons on both ends of a spool with single feedback of working pressure and regulating restriction at inlet. In this study the static analysis presents the specific relationships among design parameters for constant flow rate and the dynamic analyses give the variations around the constant flow rate as the working pressure fluctuates.

Catheter Occlusion in Home Infusion: The Influence of Needleless Connector Design on Central Catheter Occlusion.

PubMed

Williams, Ann

Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.

Estimation of Stormwater Interception Rate for various LID Facilities

NASA Astrophysics Data System (ADS)

Kim, S.; Lee, O.; Choi, J.

2017-12-01

In this study, the stormwater interception rate is proposed to apply in the design of LID facilities. For this purpose, EPA-SWMM is built with some areas of Noksan National Industrial Complex where long-term observed stormwater data were monitored and stormwater interception rates for various design capacities of various LID facilities are estimated. While the sensitivity of stormwater interception rate according to design specifications of bio-retention and infiltration trench facilities is not large, the sensitivity of stormwater interception rate according to local rainfall characteristics is relatively big. As a result of comparing the present rainfall interception rate estimation method which is officially operated in Korea with the one proposed in this study, it will be presented that the present method is highly likely to overestimate the performance of the bio-retention and infiltration trench facilities. Finally, a new stormwater interception rate formulas for the bio-retention and infiltration trench LID facilities will be proposed. Acknowledgement This research was supported by a grant (2016000200002) from Public Welfare Technology Development Program funded by Ministry of Environment of Korean government.

High Capacity Communications From Martian Distances. Part 1; Spacecraft Link Design Analysis

NASA Technical Reports Server (NTRS)

Vyas, Hemali N.; Schuchman, Leonard; Orr, Richard; Williams, Wallace Dan; Collins, Michael; Noreen, Gary

2006-01-01

High capacity space communications has been a desire for Human Exploration and Science missions. Current Mars missions operate at data rates of 120 kbps for telemetry downlink and it is desirable to study high rate communication links in the range of 100 Mbps to 1 Gbps data rates from Martian distances. This paper will present some assumed scenarios along with link design assumptions and link analysis for high capacity communications from Mars. The paper will focus on RF subsystems namely antenna and power for the downlink communication from a relay orbiter at Mars. The relay orbiter will communicate with the low orbit spacecrafts at Mars or any Martian surface elements such as robots, and relay the data back to the ground networks on Earth. The study will dive into the spacecraft downlink system design and communication link analysis between the relay orbiter and ground network on Earth for data rates ranging from 100 Mbps to 1 Gbps based on the assumed scenarios and link assumptions. With high rate links at larger distances, there will be a significant impact on the antenna and power requirements and the link design will make an attempt to minimize the mass of the RF subsystem on the spacecraft. The results of this study will be presented for three data rates 1 Gbps, 500 Mbps and 100 Mbps at maximum Mars to Earth distance of 2.67AU. The design will use a Ka-band downlink with 90% link availability, along with various ground network G/T assumptions and possible bandwidth efficient modulations. The paper will conclude with what types of high rate communication links are feasible from Martian distances and also identify a range of requirements for antenna and power technologies for these high capacity communications from Mars.

Angular rate optimal design for the rotary strapdown inertial navigation system.

PubMed

Yu, Fei; Sun, Qian

2014-04-22

Due to the characteristics of high precision for a long duration, the rotary strapdown inertial navigation system (RSINS) has been widely used in submarines and surface ships. Nowadays, the core technology, the rotating scheme, has been studied by numerous researchers. It is well known that as one of the key technologies, the rotating angular rate seriously influences the effectiveness of the error modulating. In order to design the optimal rotating angular rate of the RSINS, the relationship between the rotating angular rate and the velocity error of the RSINS was analyzed in detail based on the Laplace transform and the inverse Laplace transform in this paper. The analysis results showed that the velocity error of the RSINS depends on not only the sensor error, but also the rotating angular rate. In order to minimize the velocity error, the rotating angular rate of the RSINS should match the sensor error. One optimal design method for the rotating rate of the RSINS was also proposed in this paper. Simulation and experimental results verified the validity and superiority of this optimal design method for the rotating rate of the RSINS.

Certainty rating in pre-and post-tests of study modules in an online clinical pharmacy course - A pilot study to evaluate teaching and learning.

PubMed

Luetsch, Karen; Burrows, Judith

2016-10-14

Graduate and post-graduate education for health professionals is increasingly delivered in an e-learning environment, where automated, continuous formative testing with integrated feedback can guide students' self-assessment and learning. Asking students to rate the certainty they assign to the correctness of their answers to test questions can potentially provide deeper insights into the success of teaching, with test results informing course designers whether learning outcomes have been achieved. It may also have implications for decision making in clinical practice. A study of pre-and post-tests for five study modules was designed to evaluate the teaching and learning within a pharmacotherapeutic course in an online postgraduate clinical pharmacy program. Certainty based marking of multiple choice questions (MCQ) was adapted for formative pre- and post-study module testing by asking students to rate their certainty of correctness of MCQ answers. Paired t-tests and a coding scheme were used to analyse changes in answers and certainty between pre-and post-tests. A survey evaluated students' experience with the novel formative testing design. Twenty-nine pharmacists enrolled in the postgraduate program participated in the study. Overall 1315 matched pairs of MCQ answers and certainty ratings between pre- and post-module tests were available for evaluation. Most students identified correct answers in post-tests and increased their certainty compared to pre-tests. Evaluation of certainty ratings in addition to correctness of answers identified MCQs and topic areas for revision to course designers. A survey of students showed that assigning certainty ratings to their answers assisted in structuring and focusing their learning throughout online study modules, facilitating identification of areas of uncertainty and gaps in their clinical knowledge. Adding certainty ratings to MCQ answers seems to engage students with formative testing and feedback and focus their learning in a web-based postgraduate pharmacy course. It also offers deeper insight into the successful delivery of online course content, identifying areas for improvement of teaching and content delivery as well as test question design.

[Stent-assisted recanalization of femoropopliteal arterial occlusive disease. Influence of stent design on patency rates].

PubMed

Treitl, M; Reiser, M F; Treitl, K M

2016-03-01

Despite enormous technical progress the results of endovascular treatment of the femoropopliteal vasculature are unsatisfactory and its role is still controversially discussed. In the past decade numerous new stent designs have come onto the market but it is unclear whether they have benefits with respect to patency rates. Comparison of published data on patency rates and target lesion revascularization rates after use of different stent designs in the femoropopliteal vasculature. Analysis of 25 published studies and registries from 2006 to 2015 for classical open-cell stents, interwoven stents and partially or fully covered stents. The published data are heterogeneous and comparative studies for different stent designs are completely missing. Over the past decade the patency rates after femoropopliteal stenting could be improved. According to available data stenting of short lesions < 5 cm does not show any benefit compared to isolated balloon angioplasty. Primary stenting is now recommended for intermediate and longer lesions > 6.4 cm. Due to the heterogeneity of published data a clear benefit for a specific stent design is not obvious; however, data for interwoven stents are promising and show a tendency towards improved patency, at least for certain lesions. Randomized controlled comparative trials are needed to confirm this result.

A COMPARISON OF ANALYSIS UNITS FOR ASSOCIATING LYME DISEASE WITH FOREST-EDGE HABITAT

EPA Science Inventory

This study assessed the relationship between land-cover pattern and Lyme disease incidence rate when modeled under three designs for data aggregation. Incidence rates were calculated from passive surveillance data reported in 12 Maryland counties during 1996 – 2000. A design usin...

Multi-Reader ROC studies with Split-Plot Designs: A Comparison of Statistical Methods

PubMed Central

Obuchowski, Nancy A.; Gallas, Brandon D.; Hillis, Stephen L.

2012-01-01

Rationale and Objectives Multi-reader imaging trials often use a factorial design, where study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of the design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper we compare three methods of analysis for the split-plot design. Materials and Methods Three statistical methods are presented: Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean ANOVA approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power and confidence interval coverage of the three test statistics. Results The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% CIs fall close to the nominal coverage for small and large sample sizes. Conclusions The split-plot MRMC study design can be statistically efficient compared with the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rate, similar power, and nominal CI coverage, are available for this study design. PMID:23122570

Multi-reader ROC studies with split-plot designs: a comparison of statistical methods.

PubMed

Obuchowski, Nancy A; Gallas, Brandon D; Hillis, Stephen L

2012-12-01

Multireader imaging trials often use a factorial design, in which study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of this design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper, the authors compare three methods of analysis for the split-plot design. Three statistical methods are presented: the Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean analysis-of-variance approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power, and confidence interval coverage of the three test statistics. The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% confidence intervals falls close to the nominal coverage for small and large sample sizes. The split-plot multireader, multicase study design can be statistically efficient compared to the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rates, similar power, and nominal confidence interval coverage, are available for this study design. Copyright © 2012 AUR. All rights reserved.

A Nationwide Survey of Quality of End-of-Life Cancer Care in Designated Cancer Centers, Inpatient Palliative Care Units, and Home Hospices in Japan: The J-HOPE Study.

PubMed

Miyashita, Mitsunori; Morita, Tatsuya; Sato, Kazuki; Tsuneto, Satoru; Shima, Yasuo

2015-07-01

End-of-life (EOL) cancer care in general hospitals and home care has not previously been evaluated in Japan. This study aimed to evaluate EOL cancer care from the perspective of bereaved family members in nationwide designated cancer centers, inpatient palliative care units (PCUs), and home hospices in Japan. We conducted a cross-sectional, anonymous, self-report questionnaire survey for bereaved family members of cancer patients in March 2008 for 56 designated cancer centers and in June 2007 for 100 PCUs and 14 home hospices. Outcomes were overall care satisfaction, structure and process of care (Care Evaluation Scale), and achievement of a good death (Good Death Inventory). In designated cancer centers, PCUs, and home hospices, 2794 (response rate 59%), 5312 (response rate 69%), and 292 (response rate 67%) bereaved family members participated, respectively. Mean scores for overall care satisfaction were high for all places of death, at 4.3 ± 1.2 for designated cancer centers, 5.0 ± 1.2 for PCUs, and 5.0 ± 1.0 for home hospices. Designated cancer centers showed significantly lower ratings than PCUs and home hospices for structure and process of care and achievement of a good death (P = 0.0001 each). Home hospices were rated significantly higher than PCUs for achievement of a good death (P = 0.0001). The main findings of this study were: (1) overall, bereaved family members were satisfied with end-of-life care in all three places of death; (2) designated cancer centers were inferior to PCUs and home hospices and had more room for improvement; and 3) home hospices were rated higher than PCUs for achieving a good death, although home hospices remain uncommon in Japan. Copyright © 2015 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

The Technological Impact of the E-Rate Program on a School District of the Texas Coastal Bend Region

ERIC Educational Resources Information Center

Vazquez-Cruz, Juan Diego

2012-01-01

The purpose of the study was to examine the impact of the E-Rate program on students, teachers, administrators, and the technology environment of a public school district in the Texas Gulf Coast Region. The study was conducted through a mixed methods design, utilizing both quantitative and qualitative data collection; the research design was a…

Influence of Motivational Design on Completion Rates in Online Self-Study Pharmacy-Content Courses

ERIC Educational Resources Information Center

Pittenger, Amy; Doering, Aaron

2010-01-01

Student retention rates are a constant concern in higher education, but this concern has become especially challenging as online courses become more common and there are widespread reports of low completion rates for online, self-study courses. We evaluated four self-study online pharmacy courses with a history of very high completion rates for…

Delayed high school start times later than 8:30am and impact on graduation rates and attendance rates.

PubMed

McKeever, Pamela Malaspina; Clark, Linda

2017-04-01

The first purpose of this study was to investigate changes in high school graduation rates with a delayed school start time of later than 8:30am. The second aim of the study was to analyze the association between a delayed high school start time later than 8:30am and attendance rates. In the current study, a pre-post design using a repeated-measures analysis of variance was used to examine changes in attendance and graduation rates 2 years after a delayed start was implemented. Public high schools from 8 school districts (n=29 high schools) located throughout 7 different states. Schools were identified using previous research from the Children's National Medical Center's Division of Sleep Medicine Research Team. A total membership of more than 30,000 high school students enrolled in the 29 schools identified by the Children's National Medical Center's Research Team. A pre-post design was used for a within-subject design, controlling for any school-to-school difference in the calculation of the response variable. This is the recommended technique for a study that may include data with potential measurement error. Findings from this study linked a start time of later than 8:30am to improved attendance rates and graduation rates. Attendance rates and graduation rates significantly improved in schools with delayed start times of 8:30am or later. School officials need to take special notice that this investigation also raises questions about whether later start times are a mechanism for closing the achievement gap due to improved graduation rates. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Tradevman 3 and 2: Naval Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Naval Education and Training Command, Pensacola, FL.

The rate training manual is designed as a self-study text for Navy and Naval Reserve personnel preparing for advancement to Petty Officer Third Class (TD 3) to Second Class (TD 2) in the rating of Tradevman. Chapter 1 provides information on the enlisted rating structure, the TD rating, requirements and procedures for advancement, study references…

Development of a fast, lean and agile direct pelletization process using experimental design techniques.

PubMed

Politis, Stavros N; Rekkas, Dimitrios M

2017-04-01

A novel hot melt direct pelletization method was developed, characterized and optimized, using statistical thinking and experimental design tools. Mixtures of carnauba wax (CW) and HPMC K100M were spheronized using melted gelucire 50-13 as a binding material (BM). Experimentation was performed sequentially; a fractional factorial design was set up initially to screen the factors affecting the process, namely spray rate, quantity of BM, rotor speed, type of rotor disk, lubricant-glidant presence, additional spheronization time, powder feeding rate and quantity. From the eight factors assessed, three were further studied during process optimization (spray rate, quantity of BM and powder feeding rate), at different ratios of the solid mixture of CW and HPMC K100M. The study demonstrated that the novel hot melt process is fast, efficient, reproducible and predictable. Therefore, it can be adopted in a lean and agile manufacturing setting for the production of flexible pellet dosage forms with various release rates easily customized between immediate and modified delivery.

Aerodynamic heating and surface temperatures on vehicles for computer-aided design studies

NASA Technical Reports Server (NTRS)

Dejarnette, F. R.; Kania, L. A.; Chitty, A.

1983-01-01

A computer subprogram has been developed to calculate aerodynamic and radiative heating rates and to determine surface temperatures by integrating the heating rates along the trajectory of a vehicle. Convective heating rates are calculated by applying the axisymmetric analogue to inviscid surface streamlines and using relatively simple techniques to calculate laminar, transitional, or turbulent heating rates. Options are provided for the selection of gas model, transition criterion, turbulent heating method, Reynolds Analogy factor, and entropy-layer swallowing effects. Heating rates are compared to experimental data, and the time history of surface temperatures are given for a high-speed trajectory. The computer subprogram is developed for preliminary design and mission analysis where parametric studies are needed at all speeds.

Personalized Progressive Addition Lenses: Correlation between Performance and Design.

PubMed

Forkel, Johanne; Reiniger, Jenny Lorén; Muschielok, Adam; Welk, Andrea; Seidemann, Anne; Baumbach, Peter

2017-02-01

A continuous set of personalized designs (design space) for progressive addition lenses (PALs) is investigated. The main goals are (1) to study how the subjects' perception of a personalized design depends on its position in the design space and (2) to compare the performance of personalized PALs to a conventional PAL with a fixed design. In a double-blind study, 51 subjects compared Rodenstock Impression FreeSign 3, which is a family of PALs with a continuously controllable personalized design, and Rodenstock Progressiv Life Free, which is a conventional PAL with a single fixed design. The positions and sizes of viewing zones and the softness of gradients of mean power and astigmatism of personalized lenses were customized to individual viewing preferences. These designs were represented as points in a design space comprising a continuum of PAL designs. Subjective ratings and experimental measurements were used to study viewing zone widths, blur gradient smoothness, amount of distortion, the feeling of safety during motion, and overall wearing comfort. (1) Far viewing zone width (experiments and ratings), near viewing zone width (experiments), blur gradient smoothness, and the amount of distortion (ratings) were significantly dependent on the position of the personalized lens design in the design space. This was consistent with the structure of the design space. (2) 82% of the subjects chose personalized lenses as their favorite. Most subjects reported higher wearing comfort and tolerability with personalized lenses than with conventional lenses. The designs of the tested personalized lenses were perceived by the subjects as intended. This is a prerequisite to the successful customization of PALs to individual wearing preferences. Possible reasons for the preference of the tested personalized lenses are the optimization with respect to individual wearing conditions and the personalization.

A quantitative approach to evaluating caring in nursing simulation.

PubMed

Eggenberger, Terry L; Keller, Kathryn B; Chase, Susan K; Payne, Linda

2012-01-01

This study was designed to test a quantitative method of measuring caring in the simulated environment. Since competency in caring is central to nursing practice, ways of including caring concepts in designing scenarios and in evaluation of performance need to be developed. Coates' Caring Efficacy scales were adapted for simulation and named the Caring Efficacy Scale-Simulation Student Version (CES-SSV) and Caring Efficacy Scale-Simulation Faculty Version (CES-SFV). A correlational study was designed to compare student self-ratings with faculty ratings on caring efficacy during an adult acute simulation experience with traditional and accelerated baccalaureate students in a nursing program grounded in caring theory. Student self-ratings were significantly correlated with objective ratings (r = 0.345, 0.356). Both the CES-SSV and the CES-SFV were found to have excellent internal consistency and significantly correlated interrater reliability. They were useful in measuring caring in the simulated learning environment.

Design of rocker switches for work-vehicles--an application of Kansei Engineering.

PubMed

Schütte, Simon; Eklund, Jörgen

2005-09-01

Rocker switches used in vehicles meet high demands partly due to the increased focus on customer satisfaction. Previous studies focused on ergonomics and usability rather than design for emotions and affection. The aim of this study was to determine how and to what extent engineering properties influence the perception of rocker switches. Secondary aims were to compare two types of rating scales and to determine consistency over time of the ratings. As a method Kansei Engineering was used, describing a product domain from a physical and semantic point of view. A model was built and validated, and recommendations for new designs were given. It was seen that the subjective impressions of robustness, precision and design are strongly influenced by the zero position, the contact position, the form-ratio, shape and the surface of rocker switches. A 7-point scale was found suitable. The Kansei ratings were consistent over time.

The Impact of Biofuels on Climate Change from Marginal Land over East Asia using the RegCM4

NASA Astrophysics Data System (ADS)

Kim, S.; Lee, O.; Choi, J.

2016-12-01

In this study, the stormwater interception rate is proposed to apply in the design of LID facilities. For this purpose, EPA-SWMM is built with some areas of Noksan National Industrial Complex where long-term observed stormwater data were monitored and stormwater interception rates for various design capacities of various LID facilities are estimated. While the sensitivity of stormwater interception rate according to design specifications of bio-retention and infiltration trench facilities is not large, the sensitivity of stormwater interception rate according to local rainfall characteristics is relatively big. As a result of comparing the present rainfall interception rate estimation method which is officially operated in Korea with the one proposed in this study, it will be presented that the present method is highly likely to overestimate the performance of the bio-retention and infiltration trench facilities. Finally, a new stormwater interception rate formulas for the bio-retention and infiltration trench LID facilities will be proposed. Acknowledgement This research was supported by a grant (2016000200002) from Public Welfare Technology Development Program funded by Ministry of Environment of Korean government.

A comparative study of two shovel designs.

PubMed

Degani, A; Asfour, S S; Waly, S M; Koshy, J G

1993-10-01

In the present study a modified shovel design with two perpendicular shafts is presented. This modified, two-shaft shovel was compared with a regular shovel. The modified shovel was evaluated and tested in a controlled laboratory environment using surface electromyography recorded from the lumbar paraspinal muscles. The new shovel design was also tested in a field study using ratings of perceived exertion. The results indicate that there was a significant reduction in EMG values of the lumbar paraspinal muscles and a consistent reduction in perceived exertion ratings while the modified shovel was being used for removing dirt in digging trenches up to 90 cm in depth.

Influence of architecture and material properties on vanadium redox flow battery performance

NASA Astrophysics Data System (ADS)

Houser, Jacob; Clement, Jason; Pezeshki, Alan; Mench, Matthew M.

2016-01-01

This publication reports a design optimization study of all-vanadium redox flow batteries (VRBs), including performance testing, distributed current measurements, and flow visualization. Additionally, a computational flow simulation is used to support the conclusions made from the experimental results. This study demonstrates that optimal flow field design is not simply related to the best architecture, but is instead a more complex interplay between architecture, electrode properties, electrolyte properties, and operating conditions which combine to affect electrode convective transport. For example, an interdigitated design outperforms a serpentine design at low flow rates and with a thin electrode, accessing up to an additional 30% of discharge capacity; but a serpentine design can match the available discharge capacity of the interdigitated design by increasing the flow rate or the electrode thickness due to differing responses between the two flow fields. The results of this study should be useful to design engineers seeking to optimize VRB systems through enhanced performance and reduced pressure drop.

Longitudinal design considerations to optimize power to detect variances and covariances among rates of change: Simulation results based on actual longitudinal studies

PubMed Central

Rast, Philippe; Hofer, Scott M.

2014-01-01

We investigated the power to detect variances and covariances in rates of change in the context of existing longitudinal studies using linear bivariate growth curve models. Power was estimated by means of Monte Carlo simulations. Our findings show that typical longitudinal study designs have substantial power to detect both variances and covariances among rates of change in a variety of cognitive, physical functioning, and mental health outcomes. We performed simulations to investigate the interplay among number and spacing of occasions, total duration of the study, effect size, and error variance on power and required sample size. The relation between growth rate reliability (GRR) and effect size to the sample size required to detect power ≥ .80 was non-linear, with rapidly decreasing sample sizes needed as GRR increases. The results presented here stand in contrast to previous simulation results and recommendations (Hertzog, Lindenberger, Ghisletta, & von Oertzen, 2006; Hertzog, von Oertzen, Ghisletta, & Lindenberger, 2008; von Oertzen, Ghisletta, & Lindenberger, 2010), which are limited due to confounds between study length and number of waves, error variance with GCR, and parameter values which are largely out of bounds of actual study values. Power to detect change is generally low in the early phases (i.e. first years) of longitudinal studies but can substantially increase if the design is optimized. We recommend additional assessments, including embedded intensive measurement designs, to improve power in the early phases of long-term longitudinal studies. PMID:24219544

Bayesian enhancement two-stage design for single-arm phase II clinical trials with binary and time-to-event endpoints.

PubMed

Shi, Haolun; Yin, Guosheng

2018-02-21

Simon's two-stage design is one of the most commonly used methods in phase II clinical trials with binary endpoints. The design tests the null hypothesis that the response rate is less than an uninteresting level, versus the alternative hypothesis that the response rate is greater than a desirable target level. From a Bayesian perspective, we compute the posterior probabilities of the null and alternative hypotheses given that a promising result is declared in Simon's design. Our study reveals that because the frequentist hypothesis testing framework places its focus on the null hypothesis, a potentially efficacious treatment identified by rejecting the null under Simon's design could have only less than 10% posterior probability of attaining the desirable target level. Due to the indifference region between the null and alternative, rejecting the null does not necessarily mean that the drug achieves the desirable response level. To clarify such ambiguity, we propose a Bayesian enhancement two-stage (BET) design, which guarantees a high posterior probability of the response rate reaching the target level, while allowing for early termination and sample size saving in case that the drug's response rate is smaller than the clinically uninteresting level. Moreover, the BET design can be naturally adapted to accommodate survival endpoints. We conduct extensive simulation studies to examine the empirical performance of our design and present two trial examples as applications. © 2018, The International Biometric Society.

Levels of Evidence in Cosmetic Surgery: Analysis and Recommendations Using a New CLEAR Classification

PubMed Central

2013-01-01

Background: The Level of Evidence rating was introduced in 2011 to grade the quality of publications. This system evaluates study design but does not assess several other quality indicators. This study introduces a new “Cosmetic Level of Evidence And Recommendation” (CLEAR) classification that includes additional methodological criteria and compares this new classification with the existing system. Methods: All rated publications in the Cosmetic Section of Plastic and Reconstructive Surgery, July 2011 through June 2013, were evaluated. The published Level of Evidence rating (1–5) and criteria relevant to study design and methodology for each study were tabulated. A new CLEAR rating was assigned to each article, including a recommendation grade (A–D). The published Level of Evidence rating (1–5) was compared with the recommendation grade determined using the CLEAR classification. Results: Among the 87 cosmetic articles, 48 studies (55%) were designated as level 4. Three articles were assigned a level 1, but they contained deficiencies sufficient to undermine the conclusions. The correlation between the published Level of Evidence classification (1–5) and CLEAR Grade (A–D) was weak (ρ = 0.11, not significant). Only 41 studies (48%) evaluated consecutive patients or consecutive patients meeting inclusion criteria. Conclusions: The CLEAR classification considers methodological factors in evaluating study reliability. A prospective study among consecutive patients meeting eligibility criteria, with a reported inclusion rate, the use of contemporaneous controls when indicated, and consideration of confounders is a realistic goal. Such measures are likely to improve study quality. PMID:25289261

Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review.

PubMed

Cusimano, Michael D; Nastis, Sofia; Zuccaro, Laura

2013-01-08

The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey. We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries. We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.2-5.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed. Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required.

Angular Rate Optimal Design for the Rotary Strapdown Inertial Navigation System

PubMed Central

Yu, Fei; Sun, Qian

2014-01-01

Due to the characteristics of high precision for a long duration, the rotary strapdown inertial navigation system (RSINS) has been widely used in submarines and surface ships. Nowadays, the core technology, the rotating scheme, has been studied by numerous researchers. It is well known that as one of the key technologies, the rotating angular rate seriously influences the effectiveness of the error modulating. In order to design the optimal rotating angular rate of the RSINS, the relationship between the rotating angular rate and the velocity error of the RSINS was analyzed in detail based on the Laplace transform and the inverse Laplace transform in this paper. The analysis results showed that the velocity error of the RSINS depends on not only the sensor error, but also the rotating angular rate. In order to minimize the velocity error, the rotating angular rate of the RSINS should match the sensor error. One optimal design method for the rotating rate of the RSINS was also proposed in this paper. Simulation and experimental results verified the validity and superiority of this optimal design method for the rotating rate of the RSINS. PMID:24759115

Flow Cell Design for Effective Biosensing

PubMed Central

Pike, Douglas J.; Kapur, Nikil; Millner, Paul A.; Stewart, Douglas I.

2013-01-01

The efficiency of three different biosensor flow cells is reported. All three flow cells featured a central channel that expands in the vicinity of the sensing element to provide the same diameter active region, but the rate of channel expansion and contraction varied between the designs. For each cell the rate at which the analyte concentration in the sensor chamber responds to a change in the influent analyte concentration was determined numerically using a finite element model and experimentally using a flow-fluorescence technique. Reduced flow cell efficiency with increasing flow rates was observed for all three designs and was related to the increased importance of diffusion relative to advection, with efficiency being limited by the development of regions of recirculating flow (eddies). However, the onset of eddy development occurred at higher flow rates for the design with the most gradual channel expansion, producing a considerably more efficient flow cell across the range of flow rates considered in this study. It is recommended that biosensor flow cells be designed to minimize the tendency towards, and be operated under conditions that prevent the development of flow recirculation. PMID:23344373

Factor Structure of the Behavior Flexibility Rating Scale (BFRS)

ERIC Educational Resources Information Center

Pituch, Keenan A.; Green, Vanessa A.; Sigafoos, Jeff; Itchon, Jonathan; O'Reilly, Mark; Lancioni, Giulio E.; Didden, Robert

2007-01-01

The Behavior Flexibility Rating Scale (BFRS) is designed to assess insistence on sameness or lack of behavioral flexibility, which is often associated with autism and other developmental disabilities. This study was designed to assess the factor structure of this scale for a sample of 968 individuals with autism, Asperger's syndrome, and Down…

Incidence and prevalence rates of diabetes mellitus in Saudi Arabia: An overview.

PubMed

Alotaibi, Abdulellah; Perry, Lin; Gholizadeh, Leila; Al-Ganmi, Ali

2017-12-01

This study aimed to report on the trends in incidence and prevalence rates of diabetes mellitus in Saudi Arabia over the last 25 years (1990-2015). A descriptive review. A systematic search was conducted for English-language, peer reviewed publications of any research design via Medline, EBSCO, PubMed and Scopus from 1990 to 2015. Of 106 articles retrieved, after removal of duplicates and quality appraisal, 8 studies were included in the review and synthesised based on study characteristics, design and findings. Studies originated from Saudi Arabia and applied a variety of research designs and tools to diagnosis diabetes. Of the 8 included studies; three reported type 1 diabetes and five on type 2 diabetes. Overall, findings indicated that the incidence and prevalence rate of diabetes is rising particularly among females, older children/adolescent and in urban areas. Further development are required to assess the health intervention, polices, guidelines, self-management programs in Saudi Arabia. Copyright © 2017. Published by Elsevier Ltd.

Glasses-type wearable computer displays: usability considerations examined with a 3D glasses case study.

PubMed

Chang, Joonho; Moon, Seung Ki; Jung, Kihyo; Kim, Wonmo; Parkinson, Matthew; Freivalds, Andris; Simpson, Timothy W; Baik, Seon Pill

2018-05-01

This study presents usability considerations and solutions for the design of glasses-type wearable computer displays and examines their effectiveness in a case study. Design countermeasures were investigated by a four-step design process: (1) preliminary design analysis; (2) design idea generation; (3) final design selection; and (4) virtual fitting trial. Three design interventions were devised from the design process: (1) weight balance to reduce pressure concentrated on the nose, (2) compliant temples to accommodate diverse head sizes and (3) a hanger mechanism to help spectacle users hang their wearable display on their eye glasses. To investigate their effectiveness, in the case study, the novel 3D glasses adopting the three interventions were compared with two existing 3D glasses in terms of neck muscle fatigue and subjective discomfort rating. While neck muscle fatigue was not significantly different among the three glasses (p = 0.467), the novel glasses had significantly smaller discomfort ratings (p = 0.009). Relevance to Industry: A four-step design process identified usability considerations and solutions for the design of glasses-type wearable computer displays. A novel 3D glasses was proposed through the process and its effectiveness was validated. The results identify design considerations and opportunities relevant to the emerging wearable display industry.

An in vitro comparison of fluid leakage after dural puncture with Atraucan, Sprotte, Whitacre, and Quincke needles.

PubMed

Morrison, L M; McCrae, A F; Foo, I; Scott, D B; Wildsmith, J A

1996-01-01

The study was designed to evaluate the influence of needle size and design on the rate of leakage following dural puncture. An in vitro model and fresh human lumbar dura were used to examine the rate of fluid leakage after puncture with Sprotte (24-gauge and 26-gauge), Atraucan (24-gauge and 26-gauge), Quincke (26-gauge and 29-gauge), and Whitacre (22-gauge and 25-gauge) needles. The study confirmed that finer-gauge needles tend to produce less leakage and that traditional Quincke pattern bevels result in greater leakage than pencil-point designs of the same diameter. The comparably low leakage rate produced by the Atraucan, a new needle with a terminal opening, suggests that this needle is worthy of further clinical evaluation.

[Design of sponge city and its inspiration to landscape ecology: A case of Liaodong Bay area of Panjin City, Northeast China].

PubMed

Sui, Jin Ling; Liu, Miao; Li, Chun Lin; Hu, Yuan Man; Wu, Yi Lin; Liu, Chong

2017-03-18

With the expansion of urban area, many cities are facing urban water environment issues, i.e., water resources shortage, lack of groundwater reserves, water pollution, urban waterlogging. For resolving these urban issues, 'sponge city' was proposed in 2015 in China. Liaodong Bay area of Panjin City in Liaoning Province of China was chosen as case study. Based on 'Sponge City Construction Technology Guide: Low Impact Development Rainwater System Building (Trial)', the underlying surface and types of land use in the typical area were analyzed. Sponge city plan of the study area was designed through combining topography, hydrology, rainfall intensity and other factors, and selecting LID measures. The results showed that when the study area reached the ove-rall target control rate (the control rate of the total annual runoff was ＞75%), the subsidence greenbelt rate was 1%-31%, with a total area of 13.73 km 2 ; the pervious pavement rate was 1%-13%, with a total area of 2.29 km 2 . This study could provide a case study for planning and designing of 'sponge city', proposing new ideas and methods for the research on landscape pattern and process.

Publication rate of abstracts presented at the 2010 Canadian Ophthalmological Society Annual Meeting.

PubMed

Basilious, Alfred; Benavides Vargas, Ana Maria; Buys, Yvonne M

2017-08-01

To evaluate the publication rate of submitted abstracts accepted for presentation at the 2010 Canadian Ophthalmological Society (COS) Annual Meeting in peer-reviewed journals. A retrospective analysis and literature search of abstracts presented at the 2010 COS Annual Meeting. Abstracts accepted as an oral presentation or poster from the 2010 COS Annual Meeting were tabulated by type of presentation (oral vs poster), subspecialty, study design, number of authors, and principal investigator's institution. A PubMed search was conducted for each abstract by key word, first author, and last author. The year of publication, journal, and impact factor were recorded for identified publications. Publication rate was calculated by type of presentation, subspecialty, study design, number of authors, and institution. A total of 175 abstracts were presented at the 2010 COS Annual Meeting. There were 105 oral (60%) and 70 poster (40%) presentations. The overall publication rate was 45.7%; 49.5% for oral presentations and 40.0% for posters. Cornea (57.6%) and public health (54.5%) had the highest publication rates of all subspecialties. Randomized control trials (71.4%) and cohort studies (70.0%) had higher publication rates than other study designs. Overall, 28.8% of abstracts were published in the Canadian Journal of Ophthalmology. The average impact factor of all publications was 2.73. Of abstracts presented at the 2010 COS Annual Meeting, 45.7% were published within 5 years after the conference. This publication rate is within the upper end of previously reported meeting publication rates for medical societies. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Funding Source and Research Report Quality in Nutrition Practice-Related Research

PubMed Central

Myers, Esther F.; Parrott, J. Scott; Cummins, Deborah S.; Splett, Patricia

2011-01-01

Background The source of funding is one of many possible causes of bias in scientific research. One method of detecting potential for bias is to evaluate the quality of research reports. Research exploring the relationship between funding source and nutrition-related research report quality is limited and in other disciplines the findings are mixed. Objective The purpose of this study is to determine whether types of funding sources of nutrition research are associated with differences in research report quality. Design A retrospective study of research reporting quality, research design and funding source was conducted on 2539 peer reviewed research articles from the American Dietetic Association's Evidence Analysis Library® database. Results Quality rating frequency distributions indicate 43.3% of research reports were rated as positive, 50.1% neutral, and 6.6% as negative. Multinomial logistic regression results showed that while both funding source and type of research design are significant predictors of quality ratings (χ2 = 118.99, p<0.001), the model's usefulness in predicting overall research report quality is little better than chance. Compared to research reports with government funding, those not acknowledging any funding sources, followed by studies with University/hospital funding were more likely to receive neutral vs positive quality ratings, OR = 1.85, P <0.001 and OR = 1.54, P<0.001, respectively and those that did not report funding were more likely to receive negative quality ratings (OR = 4.97, P<0.001). After controlling for research design, industry funded research reports were no more likely to receive a neutral or negative quality rating than those funded by government sources. Conclusion Research report quality cannot be accurately predicted from the funding source after controlling for research design. Continued vigilance to evaluate the quality of all research regardless of the funding source and to further understand other factors that affect quality ratings are warranted. PMID:22163017

The experimental study of matching between centrifugal compressor impeller and diffuser

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

Tamaki, H.; Nakao, H.; Saito, M.

1999-01-01

the centrifugal compressor for a marine use turbocharger with its design pressure ratio of 3.2 was tested with a vaneless diffuser and various vaned diffusers. Vaned diffusers were chosen to cover impeller operating range as broad as possible. The analysis of the static pressure ratio in the impeller and the diffusing system, consisting of the diffuser and scroll, showed that there were four possible combinations of characteristics of impeller pressure ratio and diffusing system pressure ratio. The flow rate, Q{sub P}, where the impeller achieved maximum static pressure ratio, was surge flow rate of the centrifugal compressor determined by themore » critical flow rate. In order to operate the compressor at a rate lower than Q{sub P}, the diffusing system, whose pressure recovery factor was steep negative slope near Q{sub P}, was needed. When the diffuser throat area was less than a certain value, the compressor efficiency deteriorated; however, the compressor stage pressure ratio was almost constant. In this study, by reducing the diffuser throat area, the compressor could be operated at a flow rate less than 40% of its design flow rate. Analysis of the pressure ratio in the impeller and diffusing systems at design and off-design speeds showed that the irregularities in surge line occurred when the component that controlled the negative slope on the compressor stage pressure ratio changed.« less

No significant difference in depression rate in employed and unemployed in a pair-matched study design.

PubMed

Mihai, Adriana; Ricean, Alina; Voidazan, Septimiu

2014-01-01

The main objective of this study was to evaluate the differences of depression rate in employed and unemployed persons in the period of financial and economic crisis in Romania, in a pair-matched study design. The cross-sectional study uses a pair match design (395 pairs) of two groups of employed and unemployed persons. Other socio-demographic risk factors of depression (gender, age, marital status, residence, ethnicity, educational level, and profession) were controlled. The study was done in a historical period of economic crisis, 2009-2010. For the screening of depression we used the patient health questionnaire-9. There were no statistical differences (p = 0.054) between the depression rates in the employed (17.98%) and unemployed (23.80%) samples. The depression rate in both groups was higher in females, age (51-55), marital status (divorced), living in the rural area, with a low level of education and poverty. Suicidal ideas are more frequent in men, employed persons with low level of education and in unemployed persons with medium level of education. The exposure to short term unemployment status was not associated with change in depression rate in the period of financial and economic crisis in Romania, comparing with controls pair-matched. Unemployment status increases the depression rate only in vulnerable groups such as single or divorced women; and suicidal ideas were associated with the unemployment status (longer than 8 months) in men from rural area with medium level of education.

Framing the conversation: use of PRECIS-2 ratings to advance understanding of pragmatic trial design domains.

PubMed

Lipman, Paula Darby; Loudon, Kirsty; Dluzak, Leanora; Moloney, Rachael; Messner, Donna; Stoney, Catherine M

2017-11-10

There continues to be debate about what constitutes a pragmatic trial and how it is distinguished from more traditional explanatory trials. The NIH Pragmatic Trials Collaborative Project, which includes five trials and a coordinating unit, has adopted the Pragmatic-Explanatory Continuum Indicator Summary (PRECIS-2) instrument. The purpose of the study was to collect PRECIS-2 ratings at two points in time to assess whether the tool was sensitive to change in trial design, and to explore with investigators the rationale for rating shifts. A mixed-methods design included sequential collection and analysis of quantitative data (PRECIS-2 ratings) and qualitative data. Ratings were collected at two annual, in-person project meetings, and subsequent interviews conducted with investigators were recorded, transcribed, and coded using NVivo 11 Pro for Windows. Rating shifts were coded as either (1) actual change (reflects a change in procedure or protocol), (2) primarily a rating shift reflecting rater variability, or (3) themes that reflect important concepts about the tool and/or pragmatic trial design. Based on PRECIS-2 ratings, each trial was highly pragmatic at the planning phase and remained so 1 year later in the early phases of trial implementation. Over half of the 45 paired ratings for the nine PRECIS-2 domains indicated a rating change from Time 1 to Time 2 (N = 24, 53%). Of the 24 rating changes, only three represented a true change in the design of the trial. Analysis of rationales for rating shifts identified critical themes associated with the tool or pragmatic trial design more generally. Each trial contributed one or more relevant comments, with Eligibility, Flexibility of Adherence, and Follow-up each accounting for more than one. PRECIS-2 has proved useful for "framing the conversation" about trial design among members of the Pragmatic Trials Collaborative Project. Our findings suggest that design elements assessed by the PRECIS-2 tool may represent mostly stable decisions. Overall, there has been a positive response to using PRECIS-2 to guide conversations around trial design, and the project's focus on the use of the tool by this group of early adopters has provided valuable feedback to inform future trainings on the tool.

Discrimination Training Reduces High Rate Social Approach Behaviors in Angelman Syndrome: Proof of Principle

ERIC Educational Resources Information Center

Heald, M.; Allen, D.; Villa, D.; Oliver, C.

2013-01-01

This proof of principle study was designed to evaluate whether excessively high rates of social approach behaviors in children with Angelman syndrome (AS) can be modified using a multiple schedule design. Four children with AS were exposed to a multiple schedule arrangement, in which social reinforcement and extinction, cued using a novel…

Impact of school peanut-free policies on epinephrine administration.

PubMed

Bartnikas, Lisa M; Huffaker, Michelle F; Sheehan, William J; Kanchongkittiphon, Watcharoot; Petty, Carter R; Leibowitz, Robert; Hauptman, Marissa; Young, Michael C; Phipatanakul, Wanda

2017-08-01

Children with food allergies spend a large proportion of time in school but characteristics of allergic reactions in schools are not well studied. Some schools self-designate as peanut-free or have peanut-free areas, but the impact of policies on clinical outcomes has not been evaluated. We sought to determine the effect of peanut-free policies on rates of epinephrine administration for allergic reactions in Massachusetts public schools. In this retrospective study, we analyzed (1) rates of epinephrine administration in all Massachusetts public schools and (2) Massachusetts public school nurse survey reports of school peanut-free policies from 2006 to 2011 and whether schools self-designated as "peanut-free" based on policies. Rates of epinephrine administration were compared for schools with or without peanut-restrictive policies. The percentage of schools with peanut-restrictive policies did not change significantly in the study time frame. There was variability in policies used by schools self-designated as peanut-free. No policy was associated with complete absence of allergic reactions. Both self-designated peanut-free schools and schools banning peanuts from being served in school or brought from home reported allergic reactions to nuts. Policies restricting peanuts from home, served in schools, or having peanut-free classrooms did not affect epinephrine administration rates. Schools with peanut-free tables, compared to without, had lower rates of epinephrine administration (incidence rate per 10,000 students 0.2 and 0.6, respectively, P = .009). These data provide a basis for evidence-based school policies for children with food allergies. Further studies are required before decisions can be made regarding peanut-free policies in schools. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The usefulness of design of experimentation in defining the effect difficult airway factors and training have on simulator oral-tracheal intubation success rates in novice intubators.

PubMed

Thomas, Frank; Carpenter, Judi; Rhoades, Carol; Holleran, Renee; Snow, Gregory

2010-04-01

This exploratory study examined novice intubators and the effect difficult airway factors have on pre- and posttraining oral-tracheal simulation intubation success rates. Using a two-level, full-factorial design of experimentation (DOE) involving a combination of six airway factors (curved vs. straight laryngoscope blade, trismus, tongue edema, laryngeal spasm, pharyngeal obstruction, or cervical immobilization), 64 airway scenarios were prospectively randomized to 12 critical care nurses to evaluate pre- and posttraining first-pass intubation success rates on a simulator. Scenario variables and intubation outcomes were analyzed using a generalized linear mixed-effects model to determine two-way main and interactive effects. Interactive effects between the six study factors were nonsignificant (p = 0.69). For both pre- and posttraining, main effects showed the straight blade (p = 0.006), tongue edema (p = 0.0001), and laryngeal spasm (p = 0.004) significantly reduced success rates, while trismus (p = 0.358), pharyngeal obstruction (p = 0.078), and cervical immobilization did not significantly change the success rate. First-pass intubation success rate on the simulator significantly improved (p = 0.005) from pre- (19%) to posttraining (36%). Design of experimentation is useful in analyzing the effect difficult airway factors and training have on simulator intubation success rates. Future quality improvement DOE simulator research studies should be performed to help clarify the relationship between simulator factors and patient intubation rates.

A Bayesian predictive two-stage design for phase II clinical trials.

PubMed

Sambucini, Valeria

2008-04-15

In this paper, we propose a Bayesian two-stage design for phase II clinical trials, which represents a predictive version of the single threshold design (STD) recently introduced by Tan and Machin. The STD two-stage sample sizes are determined specifying a minimum threshold for the posterior probability that the true response rate exceeds a pre-specified target value and assuming that the observed response rate is slightly higher than the target. Unlike the STD, we do not refer to a fixed experimental outcome, but take into account the uncertainty about future data. In both stages, the design aims to control the probability of getting a large posterior probability that the true response rate exceeds the target value. Such a probability is expressed in terms of prior predictive distributions of the data. The performance of the design is based on the distinction between analysis and design priors, recently introduced in the literature. The properties of the method are studied when all the design parameters vary.

Study design for a hepatitis B vaccine trial.

PubMed Central

Lustbader, E D; London, W T; Blumberg, B S

1976-01-01

A short-time trial of small sample size for an evaluation of the hepatitis B vaccine is proposed and designed. The vaccine is based on the premise that antibody to the surface antigen of the hepatitis B virus is protective against viral infection. This premise is verified by using the presence of the surface antigen as the marker of infection and comparing infection rates in renal dialysis patients who had naturally acquired antibody to patients without antibody. Patients with antibody have an extremely low risk of infection. The probability of remaining uninfected decreases at an exponential rate for patients without antibody, implying a constant risk of infection at any point in time. The study design described makes use of this time independence and the observed infection rates to formulate a clinical trial which can be accomplished with a relatively small number of patients. This design might be useful if, in preliminary studies, it is shown that the vaccine produces antibody in the patients and that protection against hepatitis B virus would be beneficial to the patients. PMID:1062809

Refining Field Measurements of Methane Flux Rates from Abandoned Oil and Gas Wells

NASA Astrophysics Data System (ADS)

Lagron, C. S.; Kang, M.; Riqueros, N. S.; Jackson, R. B.

2015-12-01

Recent studies in Pennsylvania demonstrate the potential for significant methane emissions from abandoned oil and gas wells. A subset of tested wells was high emitting, with methane flux rates up to seven orders of magnitude greater than natural fluxes (up to 105 mg CH4/hour, or about 2.5LPM). These wells contribute disproportionately to the total methane emissions from abandoned oil and gas wells. The principles guiding the chamber design have been developed for lower flux rates, typically found in natural environments, and chamber design modifications may reduce uncertainty in flux rates associated with high-emitting wells. Kang et al. estimate errors of a factor of two in measured values based on previous studies. We conduct controlled releases of methane to refine error estimates and improve chamber design with a focus on high-emitters. Controlled releases of methane are conducted at 0.05 LPM, 0.50 LPM, 1.0 LPM, 2.0 LPM, 3.0 LPM, and 5.0 LPM, and at two chamber dimensions typically used in field measurements studies of abandoned wells. As most sources of error tabulated by Kang et al. tend to bias the results toward underreporting of methane emissions, a flux-targeted chamber design modification can reduce error margins and/or provide grounds for a potential upward revision of emission estimates.

Differential Caregiver and Teacher Ratings of School Readiness in a Disadvantaged Community

ERIC Educational Resources Information Center

Doyle, Orla; Finnegan, Sarah; McNamara, Kelly A.

2012-01-01

Although differential ratings by multiple informants are an important issue in survey design, few studies test the degree of difference between informants. This study examined differences in caregiver and teacher ratings of school readiness of children from a disadvantaged urban community in Ireland. School readiness was assessed using the Short…

Aviation Electrician's Mate 3 & 2. Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Coyle, John A., Jr.

This Rate Training Manual and Nonresident Career Course (RTM/NRCC) form a self-study package that will enable Aviation Electrician's (AE) Mates to help themselves fulfill the requirements of their rating. Designed for individual study and not formal classroom instruction, the RTM provides subject matter that relates directly to the occupational…

Apparently-Different Clearance Rates from Cohort Studies of Mycoplasma genitalium Are Consistent after Accounting for Incidence of Infection, Recurrent Infection, and Study Design.

PubMed

Smieszek, Timo; White, Peter J

2016-01-01

Mycoplasma genitalium is a potentially major cause of urethritis, cervicitis, pelvic inflammatory disease, infertility, and increased HIV risk. A better understanding of its natural history is crucial to informing control policy. Two extensive cohort studies (students in London, UK; Ugandan sex workers) suggest very different clearance rates; we aimed to understand the reasons and obtain improved estimates by making maximal use of the data from the studies. As M. genitalium is a sexually-transmitted infectious disease, we developed a model for time-to-event analysis that incorporates the processes of (re)infection and clearance, and fitted to data from the two cohort studies to estimate incidence and clearance rates under different scenarios of sexual partnership dynamics and study design (including sample handling and associated test sensitivity). In the London students, the estimated clearance rate is 0.80 p.a. (mean duration 15 months), with incidence 1.31%-3.93% p.a. Without adjusting for study design, corresponding estimates from the Ugandan data are 3.44 p.a. (mean duration 3.5 months) and 58% p.a. Apparent differences in clearance rates are probably mostly due to lower testing sensitivity in the Uganda study due to differences in sample handling, with 'true' clearance rates being similar, and adjusted incidence in Uganda being 28% p.a. Some differences are perhaps due to the sex workers having more-frequent antibiotic treatment, whilst reinfection within ongoing sexual partnerships might have caused some of the apparently-persistent infection in the London students. More information on partnership dynamics would inform more accurate estimates of natural-history parameters. Detailed studies in men are also required.

Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review

PubMed Central

Cusimano, Michael D.; Nastis, Sofia; Zuccaro, Laura

2013-01-01

Background: The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey. Methods: We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries. Results: We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.2–5.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed. Interpretation: Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required. PMID:23209118

State Performance-Based Regulation Using Multiyear Rate Plans for U.S. Electric Utilities

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

Lowry, Mark Newton; Makos, Matt; Deason, Jeff

Electric utilities today must contain costs at a time when many need to modernize aging systems and all face major changes in technologies, customer preferences and competitive pressures.Most U.S. electric utility facilities are investor-owned, subject to rate and service regulation by state public utility commissions. Regulatory systems under which these utilities operate affect their performance and ability to meet these challenges. In this business environment, multiyear rate plans have some advantages over traditional rate regulation.The report focuses on key design issues and provides case studies of the multiyear rate plan approach, applicable to both vertically integrated and restructured states. Markmore » Newton Lowry and Matt Makos of Pacific Energy Group Research and Jeff Deason of Berkeley Lab authored the report; Lisa Schwartz, Berkeley Lab, was project manager and technical editor.The report is aimed primarily at state utility regulators and stakeholders in the state regulatory process. The multiyear rate approach also provides ideas on how to streamline oversight of public power utilities and rural electric cooperatives for their governing boards.Two key provisions of multiyear rate plans strengthen cost containment incentives and streamline regulation: 1. Reducing frequency of rate cases, typically to every four or five years 2. Using an attrition relief mechanism to escalate rates or revenue between rate cases to address cost pressures such as inflation and growth in number of customers, independently of the utility’s own cost Better utility performance can be achieved under well-designed multiyear rate plans while achieving lower regulatory costs. Benefits can be shared between utilities and their customers. But plans can be complex and involve significant changes in the regulatory system. Designing plans that stimulate utility performance without undue risk and share benefits fairly can be challenging.This report discusses the rationale for multiyear rate plans and their usefulness under modern business conditions. It then explains critical plan design issues and challenges and presents results from numerical research that considers the extra incentive power achieved under different plan provisions. Next, the report presents several case studies of utilities that have operated under formal multiyear rate plans or, for various reasons, have stayed out of rate cases for more than a decade. These studies consider the effect of multiyear rate plans and rate case frequency on utility cost, reliability and other performance dimensions.« less

Parametric study and performance analysis of hybrid rocket motors with double-tube configuration

NASA Astrophysics Data System (ADS)

Yu, Nanjia; Zhao, Bo; Lorente, Arnau Pons; Wang, Jue

2017-03-01

The practical implementation of hybrid rocket motors has historically been hampered by the slow regression rate of the solid fuel. In recent years, the research on advanced injector designs has achieved notable results in the enhancement of the regression rate and combustion efficiency of hybrid rockets. Following this path, this work studies a new configuration called double-tube characterized by injecting the gaseous oxidizer through a head end injector and an inner tube with injector holes distributed along the motor longitudinal axis. This design has demonstrated a significant potential for improving the performance of hybrid rockets by means of a better mixing of the species achieved through a customized injection of the oxidizer. Indeed, the CFD analysis of the double-tube configuration has revealed that this design may increase the regression rate over 50% with respect to the same motor with a conventional axial showerhead injector. However, in order to fully exploit the advantages of the double-tube concept, it is necessary to acquire a deeper understanding of the influence of the different design parameters in the overall performance. In this way, a parametric study is carried out taking into account the variation of the oxidizer mass flux rate, the ratio of oxidizer mass flow rate injected through the inner tube to the total oxidizer mass flow rate, and injection angle. The data for the analysis have been gathered from a large series of three-dimensional numerical simulations that considered the changes in the design parameters. The propellant combination adopted consists of gaseous oxygen as oxidizer and high-density polyethylene as solid fuel. Furthermore, the numerical model comprises Navier-Stokes equations, k-ε turbulence model, eddy-dissipation combustion model and solid-fuel pyrolysis, which is computed through user-defined functions. This numerical model was previously validated by analyzing the computational and experimental results obtained for conventional hybrid rocket designs. In addition, a performance analysis is conducted in order to evaluate the influence in the performance provoked by the possible growth of the diameter of the inner fuel grain holes during the motor operation. The latter phenomenon is known as burn through holes. Finally, after a statistical analysis of the data, a regression rate expression as a function of the design parameters is obtained.

Change in Self-Rated Health and Mortality among Community-Dwelling Disabled Older Women

ERIC Educational Resources Information Center

Han, Beth; Phillips, Caroline; Ferrucci, Luigi; Bandeen-Roche, Karen; Jylha, Marja; Kasper, Judith; Guralnik, Jack M.

2005-01-01

Purpose: Our study assessed whether change in self-rated health is a stronger predictor of mortality than baseline self-rated health and the most recent self-rated health (prior to death or loss to follow-up) among disabled older women. Design and Methods: The Women's Health and Aging Study examined disabled older women at baseline and every 6…

Home medication support for childhood cancer: family-centered design and testing.

PubMed

Walsh, Kathleen E; Biggins, Colleen; Blasko, Deb; Christiansen, Steven M; Fischer, Shira H; Keuker, Christopher; Klugman, Robert; Mazor, Kathleen M

2014-11-01

Errors in the use of medications at home by children with cancer are common, and interventions to support correct use are needed. We sought to (1) engage stakeholders in the design and development of an intervention to prevent errors in home medication use, and (2) evaluate the acceptability and usefulness of the intervention. We convened a multidisciplinary team of parents, clinicians, technology experts, and researchers to develop an intervention using a two-step user-centered design process. First, parents and oncologists provided input on the design. Second, a parent panel and two oncology nurses refined draft materials. In a feasibility study, we used questionnaires to assess usefulness and acceptability. Medication error rates were assessed via monthly telephone interviews with parents. We successfully partnered with parents, clinicians, and IT experts to develop Home Medication Support (HoMeS), a family-centered Web-based intervention. HoMeS includes a medication calendar with decision support, a communication tool, adverse effect information, a metric conversion chart, and other information. The 15 families in the feasibility study gave HoMeS high ratings for acceptability and usefulness. Half recorded information on the calendar to indicate to other caregivers that doses were given; 34% brought it to the clinic to communicate with their clinician about home medication use. There was no change in the rate of medication errors in this feasibility study. We created and tested a stakeholder-designed, Web-based intervention to support home chemotherapy use, which parents rated highly. This tool may prevent serious medication errors in a larger study. Copyright © 2014 by American Society of Clinical Oncology.

The VA augmentation and switching treatments for improving depression outcomes (VAST-D) study: Rationale and design considerations.

PubMed

Mohamed, Somaia; Johnson, Gary R; Vertrees, Julia E; Guarino, Peter D; Weingart, Kimberly; Young, Ilanit Tal; Yoon, Jean; Gleason, Theresa C; Kirkwood, Katherine A; Kilbourne, Amy M; Gerrity, Martha; Marder, Stephen; Biswas, Kousick; Hicks, Paul; Davis, Lori L; Chen, Peijun; Kelada, AlexandraMary; Huang, Grant D; Lawrence, David D; LeGwin, Mary; Zisook, Sidney

2015-10-30

Because two-thirds of patients with Major Depressive Disorder do not achieve remission with their first antidepressant, we designed a trial of three "next-step" strategies: switching to another antidepressant (bupropion-SR) or augmenting the current antidepressant with either another antidepressant (bupropion-SR) or with an atypical antipsychotic (aripiprazole). The study will compare 12-week remission rates and, among those who have at least a partial response, relapse rates for up to 6 months of additional treatment. We review seven key efficacy/effectiveness design decisions in this mixed "efficacy-effectiveness" trial. Copyright © 2015. Published by Elsevier Ireland Ltd.

Off-design flow measurements in a centrifugal compressor vaneless diffuser

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

Pinarbasi, A.; Johnson, M.W.

1995-10-01

Detailed measurements have been taken of the three-dimensional velocity field within the vaneless diffuser of a backswept low speed centrifugal compressor using hot-wire anemometry. A 16% below and an 11% above design flow rate were used in the present study. Results at both flow rates show how the blade wake mixes out more rapidly than the passage wake. Strong secondary flows inherited from the impeller at the higher flow rate delay the mixing out of the circumferential velocity variations, but at both flow rates these circumferential variations are negligible at the last measurement station. The measured tangential/radial flow angle ismore » used to recommend optimum values for the vaneless space and vane angle for design of a vaned diffuser.« less

Greenery in the university environment: Students’ preferences and perceived restoration likelihood

PubMed Central

2018-01-01

A large body of evidence shows that interaction with greenery can be beneficial for human stress reduction, emotional states, and improved cognitive function. It can, therefore, be expected that university students might benefit from greenery in the university environment. Before investing in real-life interventions in a university environment, it is necessary to first explore students’ perceptions of greenery in the university environment. This study examined (1) preference for university indoor and outdoor spaces with and without greenery (2) perceived restoration likelihood of university outdoor spaces with and without greenery and (3) if preference and perceived restoration likelihood ratings were modified by demographic characteristics or connectedness to nature in Dutch university students (N = 722). Digital photographic stimuli represented four university spaces (lecture hall, classroom, study area, university outdoor space). For each of the three indoor spaces there were four or five stimuli conditions: (1) the standard design (2) the standard design with a colorful poster (3) the standard design with a nature poster (4) the standard design with a green wall (5) the standard design with a green wall plus interior plants. The university outdoor space included: (1) the standard design (2) the standard design with seating (3) the standard design with colorful artifacts (4) the standard design with green elements (5) the standard design with extensive greenery. Multi-level analyses showed that students gave higher preference ratings to the indoor spaces with a nature poster, a green wall, or a green wall plus interior plants than to the standard designs and the designs with the colorful posters. Students also rated preference and perceived restoration likelihood of the outdoor spaces that included greenery higher than those without. Preference and perceived restoration likelihood were not modified by demographic characteristics, but students with strong connectedness to nature rated preference and perceived restoration likelihood overall higher than students with weak connectedness to nature. The findings suggest that students would appreciate the integration of greenery in the university environment. PMID:29447184

Greenery in the university environment: Students' preferences and perceived restoration likelihood.

PubMed

van den Bogerd, Nicole; Dijkstra, S Coosje; Seidell, Jacob C; Maas, Jolanda

2018-01-01

A large body of evidence shows that interaction with greenery can be beneficial for human stress reduction, emotional states, and improved cognitive function. It can, therefore, be expected that university students might benefit from greenery in the university environment. Before investing in real-life interventions in a university environment, it is necessary to first explore students' perceptions of greenery in the university environment. This study examined (1) preference for university indoor and outdoor spaces with and without greenery (2) perceived restoration likelihood of university outdoor spaces with and without greenery and (3) if preference and perceived restoration likelihood ratings were modified by demographic characteristics or connectedness to nature in Dutch university students (N = 722). Digital photographic stimuli represented four university spaces (lecture hall, classroom, study area, university outdoor space). For each of the three indoor spaces there were four or five stimuli conditions: (1) the standard design (2) the standard design with a colorful poster (3) the standard design with a nature poster (4) the standard design with a green wall (5) the standard design with a green wall plus interior plants. The university outdoor space included: (1) the standard design (2) the standard design with seating (3) the standard design with colorful artifacts (4) the standard design with green elements (5) the standard design with extensive greenery. Multi-level analyses showed that students gave higher preference ratings to the indoor spaces with a nature poster, a green wall, or a green wall plus interior plants than to the standard designs and the designs with the colorful posters. Students also rated preference and perceived restoration likelihood of the outdoor spaces that included greenery higher than those without. Preference and perceived restoration likelihood were not modified by demographic characteristics, but students with strong connectedness to nature rated preference and perceived restoration likelihood overall higher than students with weak connectedness to nature. The findings suggest that students would appreciate the integration of greenery in the university environment.

Design and Performance Investigation for the Optical Combinational Networks at High Data Rate

NASA Astrophysics Data System (ADS)

Tripathi, Devendra Kr.

2017-05-01

This article explores performance study for optical combinational designs based on nonlinear characteristics with semiconductor optical amplifier (SOA). Two configurations for optical half-adder with non-return-to-zero modulation pattern altogether with Mach-Zehnder modulator, interferometer at 50-Gbps data rate have been successfully realized. Accordingly, SUM and CARRY outputs have been concurrently executed and verified for their output waveforms. Numerical simulations for variation of data rate and key design parameters have been effectively executed outcome with optimum performance. Investigations depict overall good performance of the design in terms of the extinction factor. It also inferred that all-optical realization based on SOA is competent scheme, as it circumvents costly optoelectronic translation. This could be well supportive to erect larger complex optical combinational circuits.

Developing a Teacher Administered Anxiety Rating Scale Suitable for Five to Seven-Year-Old Children

ERIC Educational Resources Information Center

Goulet, Joseph

2013-01-01

This paper presents results of twin studies pertinent to the development of a rating scale designed for use by teachers to identify anxious and shy children, aged 5 to 7 years, in Kindergarten and Grade One. Currently, no instruments designed specifically for this purpose exist. Children experiencing difficulty with internalizing disorders such as…

Effects of display characteristics and individual differences on preferences of VDT icon design.

PubMed

Shieh, Kong-King; Ko, Ya-Hsien

2005-04-01

This study explored the effects of display characteristics such as target/background color combination, single/simultaneous presentation, and individual differences by sex, and design specialty on preferences of VDT icon design. The results indicated black targets (black-on-white, black-on-yellow) and black backgrounds (red-on-black, yellow-on-black) were the most popular and white targets (white-on-red, white-on-black) and white backgrounds (blue-on-white, red-on-white) were the second most popular. As for the chromatic color combinations, yellow-on-blue was the most favored. Subjects rated color combinations under single presentation higher than those under simultaneous presentation. Women rated purplish targets and rated purplish and blue backgrounds higher than men. Subjects with design background favored black more either as a target or background, but they favored turquoise less than those without design background.

The dependability of medical students' performance ratings as documented on in-training evaluations.

PubMed

van Barneveld, Christina

2005-03-01

To demonstrate an approach to obtain an unbiased estimate of the dependability of students' performance ratings during training, when the data-collection design includes nesting of student in rater, unbalanced nest sizes, and dependent observations. In 2003, two variance components analyses of in-training evaluation (ITE) report data were conducted using urGENOVA software. In the first analysis, the dependability for the nested and unbalanced data-collection design was calculated. In the second analysis, an approach using multiple generalizability studies was used to obtain an unbiased estimate of the student variance component, resulting in an unbiased estimate of dependability. Results suggested that there is bias in estimates of the dependability of students' performance on ITEs that are attributable to the data-collection design. When the bias was corrected, the results indicated that the dependability of ratings of student performance was almost zero. The combination of the multiple generalizability studies method and the use of specialized software provides an unbiased estimate of the dependability of ratings of student performance on ITE scores for data-collection designs that include nesting of student in rater, unbalanced nest sizes, and dependent observations.

Aviation Boatswain's Mate F3 and 2: Naval Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Naval Education and Training Command, Pensacola, FL.

The Rate Training Manual and Nonresident Career Course (RTM/NRCC) form a self-study package that will enable Aviation Boatswain's Mates F (Fuels) to help themselves fulfill the requirements of their rating. Designed for individual study and not formal classroom instruction, the RTM provides subject matter that relates directly to the occupational…

Masked Visual Analysis: Minimizing Type I Error in Visually Guided Single-Case Design for Communication Disorders

ERIC Educational Resources Information Center

Byun, Tara McAllister; Hitchcock, Elaine R.; Ferron, John

2017-01-01

Purpose: Single-case experimental designs are widely used to study interventions for communication disorders. Traditionally, single-case experiments follow a response-guided approach, where design decisions during the study are based on participants' observed patterns of behavior. However, this approach has been criticized for its high rate of…

Preventing Smoking in Open Public Places in University Campus Settings: A Situational Crime Prevention Approach

ERIC Educational Resources Information Center

Sun, Jing; Prenzler, Tim; Buys, Nicholas; McMeniman, Marilyn

2012-01-01

Purpose: The purpose of the study was to evaluate the effectiveness of interventions using situational crime prevention approaches to reduce the smoking rate in outdoor areas of a university campus. Design/methodology/approach: A prospective intervention design was designed for the study. Surveys and observations were used to measure the impacts…

Experimental Design for a Macrofoam-Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

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

Piepel, Gregory F.; Hutchison, Janine R.

This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam-swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (culture and polymerase chain reaction) will be used. Only one previous study has investigated how the false negative rate depends on test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completing gapsmore » in the available information on the performance of macrofoam-swab sampling at low concentrations.« less

Impact of pharmacy benefit design on prescription drug utilization: a fixed effects analysis of plan sponsor data.

PubMed

Roebuck, M Christopher; Liberman, Joshua N

2009-06-01

To study the impact of various elements of pharmacy benefit design on both the absolute and relative utilization of generics, brands, retail pharmacy, and mail service. Panel data on 1,074 plan sponsors covering 21.6 million individuals over 12 calendar quarters (2005-2007). A retrospective analysis of pharmacy claims. To control for potential endogeneity, linear fixed effects models were estimated for each of six dependent variables: the generic utilization rate, the brand utilization rate, the generic dispensing rate (GDR), the retail pharmacy utilization rate, the mail service utilization rate, and the mail distribution rate. Most member cost-share variables were nonlinearly associated with changes in prescription drug utilization. Marginal effects were generally greater in magnitude for brand out-of-pocket costs than for generic out-of-pocket costs. Time dummies, as well as other pharmacy benefit design elements, also yielded significant results. Prior estimates of the effect of member cost sharing on prescription drug utilization may be biased if complex benefit designs, mail service fulfillment, and unmeasured factors such as pharmaceutical pipelines are not accounted for. Commonly cited relative utilization metrics, such as GDR, may be misleading if not examined alongside absolute prescription drug utilization.

Accounting for uncertainty in the historical response rate of the standard treatment in single-arm two-stage designs based on Bayesian power functions.

PubMed

Matano, Francesca; Sambucini, Valeria

2016-11-01

In phase II single-arm studies, the response rate of the experimental treatment is typically compared with a fixed target value that should ideally represent the true response rate for the standard of care therapy. Generally, this target value is estimated through previous data, but the inherent variability in the historical response rate is not taken into account. In this paper, we present a Bayesian procedure to construct single-arm two-stage designs that allows to incorporate uncertainty in the response rate of the standard treatment. In both stages, the sample size determination criterion is based on the concepts of conditional and predictive Bayesian power functions. Different kinds of prior distributions, which play different roles in the designs, are introduced, and some guidelines for their elicitation are described. Finally, some numerical results about the performance of the designs are provided and a real data example is illustrated. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Survival of various implant-supported prosthesis designs following 36 months of clinical function.

PubMed

Rodriguez, A M; Orenstein, I H; Morris, H F; Ochi, S

2000-12-01

The use of endosseous dental implants to replace natural teeth lost to trauma, dental caries, or periodontal disease has become a predictable form of prosthetic treatment since gaining popularity in the early 1980s. While numerous clinical studies have focused on the survival of implants, few address the survival of different prosthesis designs. Beginning in 1991, 882 prostheses supported by more than 2,900 implants (687 patients) were placed by the Department of Veterans Affairs Dental Implant Clinical Research Group (DICRG). These prostheses were divided into five research strata based on arch location. The recommended design for each stratum was: bar-supported overdenture (maxillary completely edentulous); screw-retained hybrid denture (mandibular completely edentulous); screw-retained fixed partial denture (mandibular and maxillary posterior partially edentulous); and cemented single crown (maxillary anterior single tooth). Alternative overdenture designs were utilized in the edentulous arches when the recommended prosthesis could not be fabricated. Prosthesis success rates for the research strata were calculated for an observation time of up to 36 months following prosthesis placement. Success rates for the maxillary edentulous stratum ranged from 94.6% for the bar-retained overdenture supported by five to six fixtures to 81.8% for the cap-retained overdenture. The mandibular edentulous strata produced success rates of 98.1% for the fixed hybrid prosthesis to 91.7% for the cap-retained prosthesis. Success rates for maxillary and mandibular posterior fixed partial dentures were 94.3% and 92.6%, respectively, while the maxillary anterior single-tooth prosthesis yielded a success rate of 98.1% for the 36-month observation period. The recommended prosthesis designs investigated in this study proved to be reliable, with encouraging success rates for an observation period of 36 months following placement.

The evaluation the magnitude radiation exposure dose rate in digital radiography room design

NASA Astrophysics Data System (ADS)

Dwiyanto, Agung; Setia Budi, Wahyu; Hardiman, Gagoek

2017-12-01

This study discusses the dose rate in digital radiography room, buit according to meet the provisions of KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation of BAPETEN No. 8 / 2011. The provisions primary concern of radiation safety, not comfort, by considering the space design. There are five aspects to consider in designing the space: functionality, comfort, security, movement activities and aesthetics. However provisions only met three aspects of the design, which are a function, security and movement activity. Therefore, it is necessary to evaluate digital radiography room in terms of its ability to control external radiation exposure to be safe and comfortable The dose rate is measured by the range of primary and secondary radiation in the observation points by using Surveymeter. All data are obtained by the preliminary survey prior to the study. Furthermore, the review of digital radiography room is done based on architectural design theory. The dose rate for recommended improvement room is recalculated using the same method as the actual room with the help of computer modeling. The result of dose rate calculation at the inner and outer part of digital radiography observation room shows that in-room dose for a week at each measuring point exceeds the allowable dose limit both for staff and public. During a week of observation, the outdoor dose at some measuring points exceeds the dose limit set by the KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation BEPETEN No 8/2011. Meanwhile, the result of dose rate calculation in the inner and outer part of the improved digital radiography room can meet the applicable regulations better.

Flow range enhancement by secondary flow effect in low solidity circular cascade diffusers

NASA Astrophysics Data System (ADS)

Sakaguchi, Daisaku; Tun, Min Thaw; Mizokoshi, Kanata; Kishikawa, Daiki

2014-08-01

High-pressure ratio and wide operating range are highly required for compressors and blowers. The technical issue of the design is achievement of suppression of flow separation at small flow rate without deteriorating the efficiency at design flow rate. A numerical simulation is very effective in design procedure, however, cost of the numerical simulation is generally high during the practical design process, and it is difficult to confirm the optimal design which is combined with many parameters. A multi-objective optimization technique is the idea that has been proposed for solving the problem in practical design process. In this study, a Low Solidity circular cascade Diffuser (LSD) in a centrifugal blower is successfully designed by means of multi-objective optimization technique. An optimization code with a meta-model assisted evolutionary algorithm is used with a commercial CFD code ANSYS-CFX. The optimization is aiming at improving the static pressure coefficient at design point and at low flow rate condition while constraining the slope of the lift coefficient curve. Moreover, a small tip clearance of the LSD blade was applied in order to activate and to stabilize the secondary flow effect at small flow rate condition. The optimized LSD blade has an extended operating range of 114 % towards smaller flow rate as compared to the baseline design without deteriorating the diffuser pressure recovery at design point. The diffuser pressure rise and operating flow range of the optimized LSD blade are experimentally verified by overall performance test. The detailed flow in the diffuser is also confirmed by means of a Particle Image Velocimeter. Secondary flow is clearly captured by PIV and it spreads to the whole area of LSD blade pitch. It is found that the optimized LSD blade shows good improvement of the blade loading in the whole operating range, while at small flow rate the flow separation on the LSD blade has been successfully suppressed by the secondary flow effect.

Aragon workers' health study - design and cohort description

USDA-ARS?s Scientific Manuscript database

Spain, a Mediterranean country with relatively low rates of coronary heart disease, has a high prevalence of traditional cardiovascular risk factors and is experiencing a severe epidemic of overweight/obesity. We designed the Aragon Workers' Health Study (AWHS) to characterize the factors associated...

Engineering-Based Problem Solving Strategies in AP Calculus: An Investigation into High School Student Performance on Related Rate Free-Response Problems

ERIC Educational Resources Information Center

Thieken, John

2012-01-01

A sample of 127 high school Advanced Placement (AP) Calculus students from two schools was utilized to study the effects of an engineering design-based problem solving strategy on student performance with AP style Related Rate questions and changes in conceptions, beliefs, and influences. The research design followed a treatment-control multiple…

Optimization and formulation design of gels of Diclofenac and Curcumin for transdermal drug delivery by Box-Behnken statistical design.

PubMed

Chaudhary, Hema; Kohli, Kanchan; Amin, Saima; Rathee, Permender; Kumar, Vikash

2011-02-01

The aim of this study was to develop and optimize a transdermal gel formulation for Diclofenac diethylamine (DDEA) and Curcumin (CRM). A 3-factor, 3-level Box-Behnken design was used to derive a second-order polynomial equation to construct contour plots for prediction of responses. Independent variables studied were the polymer concentration (X(1)), ethanol (X(2)) and propylene glycol (X(3)) and the levels of each factor were low, medium, and high. The dependent variables studied were the skin permeation rate of DDEA (Y(1)), skin permeation rate of CRM (Y(2)), and viscosity of the gels (Y(3)). Response surface plots were drawn, statistical validity of the polynomials was established to find the compositions of optimized formulation which was evaluated using the Franz-type diffusion cell. The permeation rate of DDEA increased proportionally with ethanol concentration but decreased with polymer concentration, whereas the permeation rate of CRM increased proportionally with polymer concentration. Gels showed a non-Fickian super case II (typical zero order) and non-Fickian diffusion release mechanism for DDEA and CRM, respectively. The design demonstrated the role of the derived polynomial equation and contour plots in predicting the values of dependent variables for the preparation and optimization of gel formulation for transdermal drug release. Copyright © 2010 Wiley-Liss, Inc.

Trace chemical contaminant generation rates for spacecraft contamination control system design

NASA Technical Reports Server (NTRS)

Perry, J. L.

1995-01-01

A spacecraft presents a unique design challenge with respect to providing a comfortable environment in which people can live and work. All aspects of the spacecraft environmental design including the size of the habitable volume, its temperature, relative humidity, and composition must be considered to ensure the comfort and health of the occupants. The crew members and the materials selected for outfitting the spacecraft play an integral part in designing a habitable spacecraft because material offgassing and human metabolism are the primary sources for continuous trace chemical contaminant generation onboard a spacecraft. Since these contamination sources cannot be completely eliminated, active control processes must be designed and deployed onboard the spacecraft to ensure an acceptably clean cabin atmosphere. Knowledge of the expected rates at which contaminants are generated is very important to the design of these processes. Data from past spacecraft missions and human contaminant production studies have been analyzed to provide this knowledge. The resulting compilation of contaminants and generation rates serve as a firm basis for past, present, and future contamination control system designs for space and aeronautics applications.

The Effects of Vehicle Redesign on the Risk of Driver Death.

PubMed

Farmer, Charles M; Lund, Adrian K

2015-01-01

This study updates a 2006 report that estimated the historical effects of vehicle design changes on driver fatality rates in the United States, separate from the effects of environmental and driver behavior changes during the same period. In addition to extending the period covered by 8 years, this study estimated the effect of design changes by model year and vehicle type. Driver death rates for consecutive model years of vehicle models without design changes were used to estimate the vehicle aging effect and the death rates that would have been expected if the entire fleet had remained unchanged from the 1985 calendar year. These calendar year estimates are taken to be the combined effect of road environment and motorist behavioral changes, with the difference between them and the actual calendar year driver fatality rates reflecting the effect of changes in vehicle design and distribution of vehicle types. The effects of vehicle design changes by model year were estimated for cars, SUVs, and pickups by computing driver death rates for model years 1984-2009 during each of their first 3 full calendar years of exposure and comparing with the expected rates if there had been no design changes. As reported in the 2006 study, had there been no changes in the vehicle fleet, driver death risk would have declined during calendar years 1985-1993 and then slowly increased from 1993 to 2004. The updated results indicate that the gradual increase would have continued through 2006, after which driver fatality rates again would have declined through 2012. Overall, it is estimated that there were 7,700 fewer driver deaths in 2012 than there would have been had vehicle designs not changed. Cars were the first vehicle type whose design safety generally exceeded that of the 1984 model year (starting in model year 1996), followed by SUVs (1998 models) and pickups (2002 models). By the 2009 model year, car driver fatality risk had declined 51% from its high in 1994, pickup driver fatality risk had declined 61% from its high in 1988, and SUV risk had declined 79% from its high in 1988. The risk of driver death in 2009 model passenger vehicles was 8% lower than that in 2008 models and about half that in 1984 models. Changes in vehicles, whether from government regulations and consumer testing that led to advanced safety designs or from other factors such as consumer demand for different sizes and types of vehicles, have been key contributors to the decline in U.S. motor vehicle occupant crash death rates since the mid-1990s. Since the early 1990s, environmental and behavioral risk factors have not shown similar improvement, until the recession of 2007, even though there are many empirically proven countermeasures that have been inadequately applied.

Field study of communication and workload in police helicopters - Implications for AI cockpit design

NASA Technical Reports Server (NTRS)

Linde, Charlotte; Shively, Robert J.

1988-01-01

This paper reports on the work performed by civilian helicopter crews, using audio and video recordings and a variety of workload measures (heart rate and subjective ratings) obtained in a field study of public service helicopter missions. The number and frequency of communications provided a significant source of workload. This is relevant to the design of automated cockpit systems, since many designs presuppose the use of voice I/O systems. Fluency of communications (including pauses, hesitation markers, repetitions, and false starts) furnished an early indication of the effects of fatigue. Three workload measures were correlated to identify high workload segments of flight, and to suggest alternate task allocations between crew members.

Accuracy of Person-Fit Statistics: A Monte Carlo Study of the Influence of Aberrance Rates

ERIC Educational Resources Information Center

St-Onge, Christina; Valois, Pierre; Abdous, Belkacem; Germain, Stephane

2011-01-01

Using a Monte Carlo experimental design, this research examined the relationship between answer patterns' aberrance rates and person-fit statistics (PFS) accuracy. It was observed that as the aberrance rate increased, the detection rates of PFS also increased until, in some situations, a peak was reached and then the detection rates of PFS…

Estimating risk and rate levels, ratios and differences in case-control studies.

PubMed

King, Gary; Zeng, Langche

2002-05-30

Classic (or 'cumulative') case-control sampling designs do not admit inferences about quantities of interest other than risk ratios, and then only by making the rare events assumption. Probabilities, risk differences and other quantities cannot be computed without knowledge of the population incidence fraction. Similarly, density (or 'risk set') case-control sampling designs do not allow inferences about quantities other than the rate ratio. Rates, rate differences, cumulative rates, risks, and other quantities cannot be estimated unless auxiliary information about the underlying cohort such as the number of controls in each full risk set is available. Most scholars who have considered the issue recommend reporting more than just risk and rate ratios, but auxiliary population information needed to do this is not usually available. We address this problem by developing methods that allow valid inferences about all relevant quantities of interest from either type of case-control study when completely ignorant of or only partially knowledgeable about relevant auxiliary population information.

Group-sequential three-arm noninferiority clinical trial designs

PubMed Central

Ochiai, Toshimitsu; Hamasaki, Toshimitsu; Evans, Scott R.; Asakura, Koko; Ohno, Yuko

2016-01-01

We discuss group-sequential three-arm noninferiority clinical trial designs that include active and placebo controls for evaluating both assay sensitivity and noninferiority. We extend two existing approaches, the fixed margin and fraction approaches, into a group-sequential setting with two decision-making frameworks. We investigate the operating characteristics including power, Type I error rate, maximum and expected sample sizes, as design factors vary. In addition, we discuss sample size recalculation and its’ impact on the power and Type I error rate via a simulation study. PMID:26892481

Tracking and data relay satellite system configuration and tradeoff study. Volume 1: Study summary

NASA Technical Reports Server (NTRS)

Hill, T. E.

1973-01-01

A study was conducted to determine the configuration and tradeoffs of a tracking and data relay satellite. The study emphasized the design of a three axis stabilized satellite and a telecommunications system optimized for support of low and medium data rate user spacecraft. Telecommunications support to low and high, or low medium, and high data rate users, considering launches with the Delta 2914, the Atlas/Centaur, and the space shuttle was also considered. The following subjects are presented: (1) launch and deployment profile, (2) spacecraft mechanical and structural design, (3) attitude stabilization and control subsystem, and (4) reliability analysis.

Combined application of mixture experimental design and artificial neural networks in the solid dispersion development.

PubMed

Medarević, Djordje P; Kleinebudde, Peter; Djuriš, Jelena; Djurić, Zorica; Ibrić, Svetlana

2016-01-01

This study for the first time demonstrates combined application of mixture experimental design and artificial neural networks (ANNs) in the solid dispersions (SDs) development. Ternary carbamazepine-Soluplus®-poloxamer 188 SDs were prepared by solvent casting method to improve carbamazepine dissolution rate. The influence of the composition of prepared SDs on carbamazepine dissolution rate was evaluated using d-optimal mixture experimental design and multilayer perceptron ANNs. Physicochemical characterization proved the presence of the most stable carbamazepine polymorph III within the SD matrix. Ternary carbamazepine-Soluplus®-poloxamer 188 SDs significantly improved carbamazepine dissolution rate compared to pure drug. Models developed by ANNs and mixture experimental design well described the relationship between proportions of SD components and percentage of carbamazepine released after 10 (Q10) and 20 (Q20) min, wherein ANN model exhibit better predictability on test data set. Proportions of carbamazepine and poloxamer 188 exhibited the highest influence on carbamazepine release rate. The highest carbamazepine release rate was observed for SDs with the lowest proportions of carbamazepine and the highest proportions of poloxamer 188. ANNs and mixture experimental design can be used as powerful data modeling tools in the systematic development of SDs. Taking into account advantages and disadvantages of both techniques, their combined application should be encouraged.

Lithium D-cell study

NASA Technical Reports Server (NTRS)

Size, P.; Takeuchi, Esther S.

1993-01-01

The purpose of this contract is to evaluate parametrically the effects of various factors including the electrolyte type, electrolyte concentration, depolarizer type, and cell configuration on lithium cell electrical performance and safety. This effort shall allow for the selection and optimization of cell design for future NASA applications while maintaining close ties with WGL's continuous improvements in manufacturing processes and lithium cell design. Taguchi experimental design techniques are employed in this task, and allow for a maximum amount of information to be obtained while requiring significantly less cells than if a full factorial design were employed. Acceptance testing for this task is modeled after the NASA Document EP5-83-025, Revision C, for cell weights, OCV's and load voltages. The performance attributes that are studied in this effort are fresh capacity and start-up characteristics evaluated at two rates and two temperatures, shelf-life characteristics including start-up and capacity retention, and iterative microcalorimetry measurements. Abuse testing includes forced over discharge at two rates with and without diode protection, temperature tolerance testing, and shorting tests at three rates with the measurement of heat generated during shorting conditions.

An Analysis of a Plan to Improve Graduation Rates in Johnston County Schools

ERIC Educational Resources Information Center

Renfrow, David Ross

2015-01-01

There have been limited qualitative case studies exploring effective strategies designed to improve graduation rates in rural school districts. Specifically, few studies have presented information based solely upon the voices of practitioners themselves in solving the graduation crisis in America's public schools. This study will add to the…

A Bayesian sequential design with adaptive randomization for 2-sided hypothesis test.

PubMed

Yu, Qingzhao; Zhu, Lin; Zhu, Han

2017-11-01

Bayesian sequential and adaptive randomization designs are gaining popularity in clinical trials thanks to their potentials to reduce the number of required participants and save resources. We propose a Bayesian sequential design with adaptive randomization rates so as to more efficiently attribute newly recruited patients to different treatment arms. In this paper, we consider 2-arm clinical trials. Patients are allocated to the 2 arms with a randomization rate to achieve minimum variance for the test statistic. Algorithms are presented to calculate the optimal randomization rate, critical values, and power for the proposed design. Sensitivity analysis is implemented to check the influence on design by changing the prior distributions. Simulation studies are applied to compare the proposed method and traditional methods in terms of power and actual sample sizes. Simulations show that, when total sample size is fixed, the proposed design can obtain greater power and/or cost smaller actual sample size than the traditional Bayesian sequential design. Finally, we apply the proposed method to a real data set and compare the results with the Bayesian sequential design without adaptive randomization in terms of sample sizes. The proposed method can further reduce required sample size. Copyright © 2017 John Wiley & Sons, Ltd.

The use of the general image quality equation in the design and evaluation of imaging systems

NASA Astrophysics Data System (ADS)

Cota, Steve A.; Florio, Christopher J.; Duvall, David J.; Leon, Michael A.

2009-08-01

The design of any modern imaging system is the end result of many trade studies, each seeking to optimize image quality within real world constraints such as cost, schedule and overall risk. The National Imagery Interpretability Rating Scale (NIIRS) is a useful measure of image quality, because, by characterizing the overall interpretability of an image, it combines into one metric those contributors to image quality to which a human interpreter is most sensitive. The main drawback to using a NIIRS rating as a measure of image quality in engineering trade studies is the fact that it is tied to the human observer and cannot be predicted from physical principles and engineering parameters alone. The General Image Quality Equation (GIQE) of Leachtenauer et al. 1997 [Appl. Opt. 36, 8322-8328 (1997)] is a regression of actual image analyst NIIRS ratings vs. readily calculable engineering metrics, and provides a mechanism for using the expected NIIRS rating of an imaging system in the design and evaluation process. In this paper, we will discuss how we use the GIQE in conjunction with The Aerospace Corporation's Parameterized Image Chain Analysis & Simulation SOftware (PICASSO) to evaluate imager designs, taking a hypothetical high resolution commercial imaging system as an example.

Vitamin C: Rate of Decay and Stability Characteristics

ERIC Educational Resources Information Center

Kakis, Frederic J.; Rossi, Carl J.

1974-01-01

Describes an experiment designed to provide the opportunity for studying some of the parameters affecting the stability of Vitamin C in various environments, and to acquaint the student with an experimental procedure for studying simple reaction kinetics and the calculations of specific rate constants. (Author/JR)

Funding source and research report quality in nutrition practice-related research.

PubMed

Myers, Esther F; Parrott, J Scott; Cummins, Deborah S; Splett, Patricia

2011-01-01

The source of funding is one of many possible causes of bias in scientific research. One method of detecting potential for bias is to evaluate the quality of research reports. Research exploring the relationship between funding source and nutrition-related research report quality is limited and in other disciplines the findings are mixed. The purpose of this study is to determine whether types of funding sources of nutrition research are associated with differences in research report quality. A retrospective study of research reporting quality, research design and funding source was conducted on 2539 peer reviewed research articles from the American Dietetic Association's Evidence Analysis Library® database. Quality rating frequency distributions indicate 43.3% of research reports were rated as positive, 50.1% neutral, and 6.6% as negative. Multinomial logistic regression results showed that while both funding source and type of research design are significant predictors of quality ratings (χ2 = 118.99, p≤0.001), the model's usefulness in predicting overall research report quality is little better than chance. Compared to research reports with government funding, those not acknowledging any funding sources, followed by studies with University/hospital funding were more likely to receive neutral vs positive quality ratings, OR = 1.85, P <0.001 and OR = 1.54, P<0.001, respectively and those that did not report funding were more likely to receive negative quality ratings (OR = 4.97, P<0.001). After controlling for research design, industry funded research reports were no more likely to receive a neutral or negative quality rating than those funded by government sources. Research report quality cannot be accurately predicted from the funding source after controlling for research design. Continued vigilance to evaluate the quality of all research regardless of the funding source and to further understand other factors that affect quality ratings are warranted.

Utilizing the Total Design Method in medicine: maximizing response rates in long, non-incentivized, personal questionnaire postal surveys.

PubMed

Kazzazi, Fawz; Haggie, Rebecca; Forouhi, Parto; Kazzazi, Nazar; Malata, Charles M

2018-01-01

Maximizing response rates in questionnaires can improve their validity and quality by reducing non-response bias. A comprehensive analysis is essential for producing reasonable conclusions in patient-reported outcome research particularly for topics of a sensitive nature. This often makes long (≥7 pages) questionnaires necessary but these have been shown to reduce response rates in mail surveys. Our work adapted the "Total Design Method," initially produced for commercial markets, to raise response rates in a long (total: 11 pages, 116 questions), non-incentivized, very personal postal survey sent to almost 350 women. A total of 346 women who had undergone mastectomy and immediate breast reconstruction from 2008-2014 (inclusive) at Addenbrooke's University Hospital were sent our study pack (Breast-Q satisfaction questionnaire and support documents) using our modified "Total Design Method." Participants were sent packs and reminders according to our designed schedule. Of the 346 participants, we received 258 responses, an overall response rate of 74.5% with a useable response rate of 72.3%. One hundred and six responses were received before the week 1 reminder (30.6%), 120 before week 3 (34.6%), 225 before the week 7 reminder (64.6%) and the remainder within 3 weeks of the final pack being sent. The median age of patients that the survey was sent to, and the median age of the respondents, was 54 years. In this study, we have demonstrated the successful implementation of a novel approach to postal surveys. Despite the length of the questionnaire (nine pages, 116 questions) and limitations of expenses to mail a survey to ~350 women, we were able to attain a response rate of 74.6%.

Interventions for the control of diarrhoeal diseases among young children: improving water supplies and excreta disposal facilities*

PubMed Central

Esrey, S. A.; Feachem, R. G.; Hughes, J. M.

1985-01-01

A theoretical model is proposed that relates the level of ingestion of diarrhoea-causing pathogens to the frequency of diarrhoea in the community. The implications of this model are that, in poor communities with inadequate water supply and excreta disposal, reducing the level of enteric pathogen ingestion by a given amount will have a greater impact on diarrhoea mortality rates than on morbidity rates, a greater impact on the incidence rate of severe diarrhoea than on that of mild diarrhoea, and a greater impact on diarrhoea caused by pathogens having high infectious doses than on diarrhoea caused by pathogens of a low infectious dose. The impact of water supply and sanitation on diarrhoea, related infections, nutritional status, and mortality is analysed by reviewing 67 studies from 28 countries. The median reductions in diarrhoea morbidity rates are 22% from all studies and 27% from a few better-designed studies. All studies of the impact on total mortality rates show a median reduction of 21%, while the few better-designed studies give a median reduction of 30%. Improvements in water quality have less of an impact than improvements in water availability or excreta disposal. PMID:3878742

75 FR 79006 - Submission for OMB Review; Comment Request; Transfusion-Transmitted Retrovirus and Hepatitis...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

...- control study design. (3) Determine nationally-representative infectious disease marker prevalence and... control number. Proposed Collection: Title: Transfusion-transmitted retrovirus and hepatitis virus rates... factors in blood donors as assessed using analytical study designs is largely unavailable in the U.S...

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1980-01-01

Engine control techniques were established and new technology requirements were identified. The designs of the components and engine were prepared in sufficient depth to calculate engine and component weights and envelopes, turbopump efficiencies and recirculation leakage rates, and engine performance. Engine design assumptions are presented along with the structural design criteria.

Rating the methodological quality of single-subject designs and n-of-1 trials: introducing the Single-Case Experimental Design (SCED) Scale.

PubMed

Tate, Robyn L; McDonald, Skye; Perdices, Michael; Togher, Leanne; Schultz, Regina; Savage, Sharon

2008-08-01

Rating scales that assess methodological quality of clinical trials provide a means to critically appraise the literature. Scales are currently available to rate randomised and non-randomised controlled trials, but there are none that assess single-subject designs. The Single-Case Experimental Design (SCED) Scale was developed for this purpose and evaluated for reliability. Six clinical researchers who were trained and experienced in rating methodological quality of clinical trials developed the scale and participated in reliability studies. The SCED Scale is an 11-item rating scale for single-subject designs, of which 10 items are used to assess methodological quality and use of statistical analysis. The scale was developed and refined over a 3-year period. Content validity was addressed by identifying items to reduce the main sources of bias in single-case methodology as stipulated by authorities in the field, which were empirically tested against 85 published reports. Inter-rater reliability was assessed using a random sample of 20/312 single-subject reports archived in the Psychological Database of Brain Impairment Treatment Efficacy (PsycBITE). Inter-rater reliability for the total score was excellent, both for individual raters (overall ICC = 0.84; 95% confidence interval 0.73-0.92) and for consensus ratings between pairs of raters (overall ICC = 0.88; 95% confidence interval 0.78-0.95). Item reliability was fair to excellent for consensus ratings between pairs of raters (range k = 0.48 to 1.00). The results were replicated with two independent novice raters who were trained in the use of the scale (ICC = 0.88, 95% confidence interval 0.73-0.95). The SCED Scale thus provides a brief and valid evaluation of methodological quality of single-subject designs, with the total score demonstrating excellent inter-rater reliability using both individual and consensus ratings. Items from the scale can also be used as a checklist in the design, reporting and critical appraisal of single-subject designs, thereby assisting to improve standards of single-case methodology.

Personalized Medicine Enrichment Design for DHA Supplementation Clinical Trial.

PubMed

Lei, Yang; Mayo, Matthew S; Carlson, Susan E; Gajewski, Byron J

2017-03-01

Personalized medicine aims to match patient subpopulation to the most beneficial treatment. The purpose of this study is to design a prospective clinical trial in which we hope to achieve the highest level of confirmation in identifying and making treatment recommendations for subgroups, when the risk levels in the control arm can be ordered. This study was motivated by our goal to identify subgroups in a DHA (docosahexaenoic acid) supplementation trial to reduce preterm birth (gestational age<37 weeks) rate. We performed a meta-analysis to obtain informative prior distributions and simulated operating characteristics to ensure that overall Type I error rate was close to 0.05 in designs with three different models: independent, hierarchical, and dynamic linear models. We performed simulations and sensitivity analysis to examine the subgroup power of models and compared results to a chi-square test. We performed simulations under two hypotheses: a large overall treatment effect and a small overall treatment effect. Within each hypothesis, we designed three different subgroup effects scenarios where resulting subgroup rates are linear, flat, or nonlinear. When the resulting subgroup rates are linear or flat, dynamic linear model appeared to be the most powerful method to identify the subgroups with a treatment effect. It also outperformed other methods when resulting subgroup rates are nonlinear and the overall treatment effect is big. When the resulting subgroup rates are nonlinear and the overall treatment effect is small, hierarchical model and chi-square test did better. Compared to independent and hierarchical models, dynamic linear model tends to be relatively robust and powerful when the control arm has ordinal risk subgroups.

Study of the Potential Energy Consumption Impacts of Connected and Automated Vehicles

EIA Publications

2017-01-01

A new study commissioned by the U.S. Energy Information Administration, finds that the introduction of connected and automated vehicle technologies have the potential to affect vehicle energy consumption, travel, usage, vehicle design and attributes, and personal ownership rates. Rate of technology development, consumer acceptance, and regulatory support and oversight will affect the rate of market penetration of these vehicle technologies.

Understanding the Declining Canadian Homicide Rate: A Test of Holinger's Relative Cohort Size Hypothesis

ERIC Educational Resources Information Center

Leenaars, Antoon A.; Lester, David

2004-01-01

Homicide rates in Canada have shown a decline since 1975, but there has been little empirical study of this trend. P. Holinger (1987) predicted and confirmed that the size of the cohort aged 15-24 in the United States population was associated with the rise and fall of the homicide rate in that country. This study was designed to test this…

Noninferiority trial designs for odds ratios and risk differences.

PubMed

Hilton, Joan F

2010-04-30

This study presents constrained maximum likelihood derivations of the design parameters of noninferiority trials for binary outcomes with the margin defined on the odds ratio (ψ) or risk-difference (δ) scale. The derivations show that, for trials in which the group-specific response rates are equal under the point-alternative hypothesis, the common response rate, π(N), is a fixed design parameter whose value lies between the control and experimental rates hypothesized at the point-null, {π(C), π(E)}. We show that setting π(N) equal to the value of π(C) that holds under H(0) underestimates the overall sample size requirement. Given {π(C), ψ} or {π(C), δ} and the type I and II error rates, or algorithm finds clinically meaningful design values of π(N), and the corresponding minimum asymptotic sample size, N=n(E)+n(C), and optimal allocation ratio, γ=n(E)/n(C). We find that optimal allocations are increasingly imbalanced as ψ increases, with γ(ψ)<1 and γ(δ)≈1/γ(ψ), and that ranges of allocation ratios map to the minimum sample size. The latter characteristic allows trialists to consider trade-offs between optimal allocation at a smaller N and a preferred allocation at a larger N. For designs with relatively large margins (e.g. ψ>2.5), trial results that are presented on both scales will differ in power, with more power lost if the study is designed on the risk-difference scale and reported on the odds ratio scale than vice versa. 2010 John Wiley & Sons, Ltd.

Methods to Limit Attrition in Longitudinal Comparative Effectiveness Trials: Lessons from the Lithium Use for Bipolar Disorder (LiTMUS) Study

PubMed Central

Sylvia, Louisa G.; Reilly-Harrington, Noreen A.; Leon, Andrew C.; Kansky, Christine I.; Ketter, Terence A.; Calabrese, Joseph R.; Thase, Michael E.; Bowden, Charles L.; Friedman, Edward S.; Ostacher, Michael J.; Iosifescu, Dan V.; Severe, Joanne; Nierenberg, Andrew A.

2013-01-01

Background High attrition rates which occur frequently in longitudinal clinical trials of interventions for bipolar disorder limit the interpretation of results. Purpose The aim of this article is to present design approaches that limited attrition in the Lithium Use for Bipolar Disorder (LiTMUS) Study. Methods LiTMUS was a 6-month randomized, longitudinal multi-site comparative effectiveness trial that examined bipolar participants who were at least mildly ill. Participants were randomized to either low to moderate doses of lithium or no lithium, in addition to other treatments needed for mood stabilization administered in a guideline-informed, empirically supported, and personalized fashion (N=283). Results Components of the study design that may have contributed to the low attrition rate of the study included use of: (1) an intent-to-treat design; (2) a randomized adjunctive single-blind design; (3) participant reimbursement; (4) intent-to-attend the next study visit (includes a discussion of attendance obstacles when intention is low); (5) quality care with limited participant burden; and (6) target windows for study visits. Limitations Site differences and the effectiveness and tolerability data have not been analyzed yet. Conclusions These components of the LiTMUS study design may have reduced the probability of attrition which would inform the design of future randomized clinical effectiveness trials. PMID:22076437

A review of how to conduct a surgical survey using a questionnaire.

PubMed

Hing, C B; Smith, T O; Hooper, L; Song, F; Donell, S T

2011-08-01

Health surveys using questionnaires facilitate the acquisition of information on the knowledge, behaviour, attitudes, perceptions and clinical history of a selected population. Their internal and external validities are threatened by poor design and low response rates. Numerous studies have investigated survey design and administration but care should be taken when generalising findings in different clinical and cultural settings. The current evidence-base suggests that no single mode of survey administration, such as postal, electronic or telephone, is superior to another. Whilst there is no evidence of an ideal response rate relationship to survey validity, response rates can be enhanced by including monetary incentives, providing a time cue, and repeat contact with non-responders. Unlike other modes of experimental data collection, few guidelines currently exist for survey and questionnaire design and response rate should not be considered a direct measure of a survey's quality. Copyright © 2010 Elsevier B.V. All rights reserved.

Effectiveness of a Marijuana Expectancy Manipulation: Piloting the Balanced-Placebo Design for Marijuana

PubMed Central

Metrik, Jane; Rohsenow, Damaris J.; Monti, Peter M.; McGeary, John; Cook, Travis A. R.; de Wit, Harriet; Haney, Margaret; Kahler, Christopher W.

2009-01-01

Although alcohol and nicotine administration studies have demonstrated that manipulating subjects’ expectancies regarding drug content affects drug response, research with marijuana has not adequately studied drug expectancy effects. The present pilot study was the first to evaluate the credibility and effect of expectancy manipulation on subjective measures and smoking patterns using a marijuana administration balanced-placebo design (BPD). In a 2 × 2 instructional set (told delta-9-tetrahydrocannabinol [THC] vs. told no THC) by drug (smoked marijuana with 2.8% THC vs. placebo) between-subjects design, the authors examined the effect of marijuana expectancy manipulation and the pharmacologic effect on affective and physiologic measures, cigarette ratings, and smoking behavior with 20 marijuana smokers (mean age = 20 years; 25% female). Large main effects of expectancy were found on ratings of cigarette potency, strength, taste, smell, and satisfaction, and observed smoking behavior. Pharmacologic effects were particularly evident for self-reported physical reactions to marijuana and cigarette potency and satisfaction ratings. This study demonstrated the feasibility of the BPD research with marijuana and yielded promising results for future studies examining the independent and combined effects of marijuana pharmacology and expectancies. PMID:19653787

Optimal groundwater remediation design of pump and treat systems via a simulation-optimization approach and firefly algorithm

NASA Astrophysics Data System (ADS)

Javad Kazemzadeh-Parsi, Mohammad; Daneshmand, Farhang; Ahmadfard, Mohammad Amin; Adamowski, Jan; Martel, Richard

2015-01-01

In the present study, an optimization approach based on the firefly algorithm (FA) is combined with a finite element simulation method (FEM) to determine the optimum design of pump and treat remediation systems. Three multi-objective functions in which pumping rate and clean-up time are design variables are considered and the proposed FA-FEM model is used to minimize operating costs, total pumping volumes and total pumping rates in three scenarios while meeting water quality requirements. The groundwater lift and contaminant concentration are also minimized through the optimization process. The obtained results show the applicability of the FA in conjunction with the FEM for the optimal design of groundwater remediation systems. The performance of the FA is also compared with the genetic algorithm (GA) and the FA is found to have a better convergence rate than the GA.

Evolution of patency rates of self-expandable bare metal stents for endovascular treatment of femoro-popliteal arterial occlusive disease: Does stent design matter?

PubMed

Treitl, Karla Maria; Woerner, Benedikt; Schinner, Regina; Czihal, Michael; Notohamiprodjo, Susan; Hoffmann, Ulrich; Treitl, Marcus

2017-09-01

To analyse the patency rates of femoro-popliteal stenting with different self-expandable Nitinol stent-designs. Two hundred and twenty-two patients (142 (64%) male; age 72.4 ± 11.6 years) with symptomatic femoro-popliteal peripheral arterial occlusive disease (PAOD) underwent percutaneous transluminal angioplasty (PTA) and stenting with three different Nitinol stents (interwoven IW: n = 70; closed-cell CC: n = 85; open-cell OC: n = 67). One-year post-procedural target lesion revascularization (TLR_12M) rates were investigated with regard to co-morbidities: diabetes (DBM), hyperlipidaemia (HLP), hypertension (RR), coronary artery disease (CAD) and degree of calcification. Twelve-month follow-up data were available for 60, 69 and 50 patients in the IW, OC and CC groups (179 patients in total). The cumulative patency (IW: 52 (86.7%); OC: 50 (72.5%); CC: 23 (46.0%); P < 0.001) and the TLR_12M rates (IW: 8 (13.3%); OC: 19 (27.5%); CC: 27 (54.0%); P < 0.001) differed significantly, as did the subgroup analyses (DBM: P = 0.05; RR: P = 0.003; HLP: P = 0.005; CAD: P = 0.02; localization: P < 0.001; calcification: P < 0.001), with the best patency for the IW stent and the highest TLR_12M for the CC stent. The interwoven stent-design was superior to the standard open- and closed-cell stent-designs in endovascular treatment of femoro-popliteal PAOD in a follow-up period of 12 months. • Results of femoro-popliteal stenting are still unsatisfactory. • Comparative studies for currently available different Nitinol stent-designs are lacking. • This is a first comparative study on long-term patency of different Nitinol stent-designs. • Interwoven stent-design leads to improved long-term patency. • Interwoven stent-design leads to lower TLR than other stent-designs.

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

Oktamuliani, Sri, E-mail: srioktamuliani@ymail.com; Su’ud, Zaki, E-mail: szaki@fi.itb.ac.id

A preliminary study designs SPINNOR (Small Power Reactor, Indonesia, No On-Site Refueling) liquid metal Pb-Bi cooled fast reactors, fuel (U, Pu)N, 150 MWth have been performed. Neutronic calculation uses SRAC which is designed cylindrical core 2D (R-Z) 90 × 135 cm, on the core fuel composed of heterogeneous with percentage difference of PuN 10, 12, 13% and the result of calculation is effective neutron multiplication 1.0488. Power density distribution of the output SRAC is generated for thermal hydraulic calculation using Delphi based on Pascal language that have been developed. The research designed a reactor that is capable of natural circulation atmore » inlet temperature 300 °C with variation of total mass flow rate. Total mass flow rate affect pressure drop and temperature outlet of the reactor core. The greater the total mass flow rate, the smaller the outlet temperature, but increase the pressure drop so that the chimney needed more higher to achieve natural circulation or condition of the system does not require a pump. Optimization of the total mass flow rate produces optimal reactor design on the total mass flow rate of 5000 kg/s with outlet temperature 524,843 °C but require a chimney of 6,69 meters.« less

High angle of attack flying qualities criteria for longitudinal rate command systems

NASA Technical Reports Server (NTRS)

Wilson, David J.; Citurs, Kevin D.; Davidson, John B.

1994-01-01

This study was designed to investigate flying qualities requirements of alternate pitch command systems for fighter aircraft at high angle of attack. Flying qualities design guidelines have already been developed for angle of attack command systems at 30, 45, and 60 degrees angle of attack, so this research fills a similar need for rate command systems. Flying qualities tasks that require post-stall maneuvering were tested during piloted simulations in the McDonnell Douglas Aerospace Manned Air Combat Simulation facility. A generic fighter aircraft model was used to test angle of attack rate and pitch rate command systems for longitudinal gross acquisition and tracking tasks at high angle of attack. A wide range of longitudinal dynamic variations were tested at 30, 45, and 60 degrees angle of attack. Pilot comments, Cooper-Harper ratings, and pilot induced oscillation ratings were taken from five pilots from NASA, USN, CAF, and McDonnell Douglas Aerospace. This data was used to form longitudinal design guidelines for rate command systems at high angle of attack. These criteria provide control law design guidance for fighter aircraft at high angle of attack, low speed flight conditions. Additional time history analyses were conducted using the longitudinal gross acquisition data to look at potential agility measures of merit and correlate agility usage to flying qualities boundaries. This paper presents an overview of this research.

Specific Language Impairment and Executive Functioning: Parent and Teacher Ratings of Behavior

ERIC Educational Resources Information Center

Wittke, Kacie; Spaulding, Tammie J.; Schechtman, Calli J.

2013-01-01

Purpose: The current study used the Behavior Rating Inventory of Executive Function--Preschool Version (BRIEF-P; Gioia, Espy, & Isquith, 2003), a rating scale designed to investigate executive behaviors in everyday activities, to examine the executive functioning of preschool children with specific language impairment (SLI) relative to their…

Factors affecting consent in pediatric critical care research.

PubMed

Menon, Kusum; Ward, Roxanne E; Gaboury, Isabelle; Thomas, Margot; Joffe, Ari; Burns, Karen; Cook, Deborah

2012-01-01

Consent for research is a difficult and unpredictable process in pediatric critical care populations. The objectives of this study were to describe consent rates in pediatric critical care research and their association with patient, legal guardian, consent process, and study design-related factors. A prospective, cohort study was conducted from 2009 to 2010 in six tertiary care pediatric intensive care units (PICU) in Canada with legal guardians of patients who were approached for consent for any ongoing PICU research study. Data were recorded on details of the consent process for all consent encounters. We recorded 271 consent encounters. The overall consent rate was 80.1% (217/271). We observed higher consent rates when the research assistant was introduced by a member of the clinical team prior to approaching the family (89.7 vs. 77.7%; P = 0.04). Legal guardians of cardiac surgery patients were less likely to provide consent than those of all other patients (75.3 vs. 86.0%; P = 0.03). There was no difference in consent rates between therapeutic (117/145, 80.7%) versus non-therapeutic studies (100/126, 79.4%; P = 0.88). This study provides future researchers with consent data for determination of recruitment rates, sample sizes, budget estimations, and study timelines. Future pediatric critical care studies should consider incorporating the lower consent rates in cardiac surgery patients and routine introduction of the research assistant to the family by a member of the patient's care team into their study designs. The potential influence of parental factors on consent rates in pediatric critical care studies requires further research.

Designing Retention Research for Assessment and Enhanced Competitive Advantage

ERIC Educational Resources Information Center

Delaney, Anne Marie

2008-01-01

Based on a longitudinal study of entering freshmen at a selective, private college in northeastern USA, this article provides a model for designing retention studies for assessment. Results from discriminant analysis revealed average high school grade, admission rating, and first semester average college grade as significant predictors of…

Testing Multiple Outcomes in Repeated Measures Designs

ERIC Educational Resources Information Center

Lix, Lisa M.; Sajobi, Tolulope

2010-01-01

This study investigates procedures for controlling the familywise error rate (FWR) when testing hypotheses about multiple, correlated outcome variables in repeated measures (RM) designs. A content analysis of RM research articles published in 4 psychology journals revealed that 3 quarters of studies tested hypotheses about 2 or more outcome…

Moving base simulation of an integrated flight and propulsion control system for an ejector-augmentor STOVL aircraft in hover

NASA Technical Reports Server (NTRS)

Mcneill, Walter, E.; Chung, William W.; Stortz, Michael W.

1995-01-01

A piloted motion simulator evaluation, using the NASA Ames Vertical Motion Simulator, was conducted in support of a NASA Lewis Contractual study of the integration of flight and propulsion systems of a STOVL aircraft. Objectives of the study were to validate the Design Methods for Integrated Control Systems (DMICS) concept, to evaluate the handling qualities, and to assess control power usage. The E-7D ejector-augmentor STOVL fighter design served as the basis for the simulation. Handling-qualities ratings were obtained during precision hover and shipboard landing tasks. Handling-qualities ratings for these tasks ranged from satisfactory to adequate. Further improvement of the design process to fully validate the DMICS concept appears to be warranted.

Influence of hip joint simulator design and mechanics on the wear and creep of metal-on-polyethylene bearings

PubMed Central

Ali, Murat; Al-Hajjar, Mazen; Partridge, Susan; Williams, Sophie; Fisher, John; Jennings, Louise M

2016-01-01

Hip joint simulators are used extensively for preclinical testing of hip replacements. The variation in simulator design and test conditions used worldwide can affect the tribological performance of polyethylene. The aim of this study was to assess the effects of simulator mechanics and design on the wear and creep of ultra-high-molecular-weight polyethylene. In the first part of this study, an electromechanical simulator and pneumatic simulator were used to compare the wear and creep of metal-on-polyethylene components under the same standard gait conditions. In the second part of the study, the same electromechanical hip joint simulator was used to investigate the influence of kinematics on wear. Higher wear rates and penetration depths were observed from the electromechanical simulator compared with the pneumatic simulator. When adduction/abduction was introduced to the gait cycle, there was no significant difference in wear with that obtained under the gait cycle condition without adduction/abduction. This study confirmed the influence of hip simulator design and loading conditions on the wear of polyethylene, and therefore direct comparisons of absolute wear rates between different hip joint simulators should be avoided. This study also confirmed that the resulting wear path was the governing factor in obtaining clinically relevant wear rates, and this can be achieved with either two axes or three axes of rotations. However, three axes of rotation (with the inclusion of adduction/abduction) more closely replicate clinical conditions and should therefore be the design approach for newly developed hip joint simulators used for preclinical testing. PMID:27160559

Influence of hip joint simulator design and mechanics on the wear and creep of metal-on-polyethylene bearings.

PubMed

Ali, Murat; Al-Hajjar, Mazen; Partridge, Susan; Williams, Sophie; Fisher, John; Jennings, Louise M

2016-05-01

Hip joint simulators are used extensively for preclinical testing of hip replacements. The variation in simulator design and test conditions used worldwide can affect the tribological performance of polyethylene. The aim of this study was to assess the effects of simulator mechanics and design on the wear and creep of ultra-high-molecular-weight polyethylene. In the first part of this study, an electromechanical simulator and pneumatic simulator were used to compare the wear and creep of metal-on-polyethylene components under the same standard gait conditions. In the second part of the study, the same electromechanical hip joint simulator was used to investigate the influence of kinematics on wear. Higher wear rates and penetration depths were observed from the electromechanical simulator compared with the pneumatic simulator. When adduction/abduction was introduced to the gait cycle, there was no significant difference in wear with that obtained under the gait cycle condition without adduction/abduction. This study confirmed the influence of hip simulator design and loading conditions on the wear of polyethylene, and therefore direct comparisons of absolute wear rates between different hip joint simulators should be avoided. This study also confirmed that the resulting wear path was the governing factor in obtaining clinically relevant wear rates, and this can be achieved with either two axes or three axes of rotations. However, three axes of rotation (with the inclusion of adduction/abduction) more closely replicate clinical conditions and should therefore be the design approach for newly developed hip joint simulators used for preclinical testing. © IMechE 2016.

Effect of lift-to-drag ratio in pilot rating of the HL-20 landing task

NASA Technical Reports Server (NTRS)

Jackson, E. B.; Rivers, Robert A.; Bailey, Melvin L.

1993-01-01

A man-in-the-loop simulation study of the handling qualities of the HL-20 lifting-body vehicle was made in a fixed-base simulation cockpit at NASA Langley Research Center. The purpose of the study was to identify and substantiate opportunities for improving the original design of the vehicle from a handling qualities and landing performance perspective. Using preliminary wind-tunnel data, a subsonic aerodynamic model of the HL-20 was developed. This model was adequate to simulate the last 75-90 s of the approach and landing. A simple flight-control system was designed and implemented. Using this aerodynamic model as a baseline, visual approaches and landings were made at several vehicle lift-to-drag ratios. Pilots rated the handling characteristics of each configuration using a conventional numerical pilot-rating scale. Results from the study showed a high degree of correlation between the lift-to-drag ratio and pilot rating. Level 1 pilot ratings were obtained when the L/D ratio was approximately 3.8 or higher.

Effect of lift-to-drag ratio in pilot rating of the HL-20 landing task

NASA Astrophysics Data System (ADS)

Jackson, E. B.; Rivers, Robert A.; Bailey, Melvin L.

1993-10-01

A man-in-the-loop simulation study of the handling qualities of the HL-20 lifting-body vehicle was made in a fixed-base simulation cockpit at NASA Langley Research Center. The purpose of the study was to identify and substantiate opportunities for improving the original design of the vehicle from a handling qualities and landing performance perspective. Using preliminary wind-tunnel data, a subsonic aerodynamic model of the HL-20 was developed. This model was adequate to simulate the last 75-90 s of the approach and landing. A simple flight-control system was designed and implemented. Using this aerodynamic model as a baseline, visual approaches and landings were made at several vehicle lift-to-drag ratios. Pilots rated the handling characteristics of each configuration using a conventional numerical pilot-rating scale. Results from the study showed a high degree of correlation between the lift-to-drag ratio and pilot rating. Level 1 pilot ratings were obtained when the L/D ratio was approximately 3.8 or higher.

Design Study of Wafer Seals for Future Hypersonic Vehicles

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H.; Finkbeiner, Joshua R.; Steinetz, Bruce M.; DeMange, Jeffrey J.

2005-01-01

Future hypersonic vehicles require high temperature, dynamic seals in advanced hypersonic engines and on the vehicle airframe to seal the perimeters of movable panels, flaps, and doors. Current seals do not meet the demanding requirements of these applications, so NASA Glenn Research Center is developing improved designs to overcome these shortfalls. An advanced ceramic wafer seal design has shown promise in meeting these needs. Results from a design of experiments study performed on this seal revealed that several installation variables played a role in determining the amount of leakage past the seals. Lower leakage rates were achieved by using a tighter groove width around the seals, a higher seal preload, a tighter wafer height tolerance, and a looser groove length. During flow testing, a seal activating pressure acting behind the wafers combined with simulated vibrations to seat the seals more effectively against the sealing surface and produce lower leakage rates. A seal geometry study revealed comparable leakage for full-scale wafers with 0.125 and 0.25 in. thicknesses. For applications in which lower part counts are desired, fewer 0.25-in.-thick wafers may be able to be used in place of 0.125-in.-thick wafers while achieving similar performance. Tests performed on wafers with a rounded edge (0.5 in. radius) in contact with the sealing surface resulted in flow rates twice as high as those for wafers with a flat edge. Half-size wafers had leakage rates approximately three times higher than those for full-size wafers.

ICU ward design and nosocomial infection rates: a cross-sectional study in Germany.

PubMed

Stiller, A; Schröder, C; Gropmann, A; Schwab, F; Behnke, M; Geffers, C; Sunder, W; Holzhausen, J; Gastmeier, P

2017-01-01

There is increasing interest in the effects of hospital and ward design on multi-faceted infection control. Definitive evidence is rare and the state of knowledge about current ward design is lacking. To collect data on the current status of ward design for intensive care units (ICUs) and to analyse associations between particular design factors and nosocomial infection rates. In 2015, operational infrastructure data were collected via an online questionnaire from ICUs participating voluntarily in the German nosocomial infection surveillance system (KISS). A multi-variate analysis was subsequently undertaken with nosocomial infection rates from the KISS database from 2014 to 2015. In total, 534 ICUs submitted data about their operational infrastructure. Of these, 27.1% of beds were hosted in single-bed rooms with a median size of 18m 2 (interquartile range 15-21m 2 ), and 73.5% of all ICU beds had a hand rub dispenser nearby. The authors were able to match 266 ICUs in the multi-variate analysis. ICUs with openable windows in patient rooms were associated with lower device-associated lower respiratory tract infections [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.58-0.90]. ICUs with >40% two-bed rooms were associated with lower primary bloodstream infection rates (OR 0.66, 95% CI 0.51-0.86). Only minor associations were found between design factors and ICU infection rates. Most were surrogates for other risk factors. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Recombination rate plasticity: revealing mechanisms by design

PubMed Central

Sefick, Stephen; Rushton, Chase

2017-01-01

For over a century, scientists have known that meiotic recombination rates can vary considerably among individuals, and that environmental conditions can modify recombination rates relative to the background. A variety of external and intrinsic factors such as temperature, age, sex and starvation can elicit ‘plastic’ responses in recombination rate. The influence of recombination rate plasticity on genetic diversity of the next generation has interesting and important implications for how populations evolve. Further, many questions remain regarding the mechanisms and molecular processes that contribute to recombination rate plasticity. Here, we review 100 years of experimental work on recombination rate plasticity conducted in Drosophila melanogaster. We categorize this work into four major classes of experimental designs, which we describe via classic studies in D. melanogaster. Based on these studies, we highlight molecular mechanisms that are supported by experimental results and relate these findings to studies in other systems. We synthesize lessons learned from this model system into experimental guidelines for using recent advances in genotyping technologies, to study recombination rate plasticity in non-model organisms. Specifically, we recommend (1) using fine-scale genome-wide markers, (2) collecting time-course data, (3) including crossover distribution measurements, and (4) using mixed effects models to analyse results. To illustrate this approach, we present an application adhering to these guidelines from empirical work we conducted in Drosophila pseudoobscura. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109222

School Is Your Job: A Case Study on School Leadership and Black Male Achievement

ERIC Educational Resources Information Center

Lee-Currie, Monica

2013-01-01

The purpose of this qualitative case study was to examine and report how four school leaders in a mid-sized, Mid-Atlantic high school created an environment that improved achievement levels, increased graduation rates, and reduced drop-out rates for Black male students. The researcher utilized a qualitative case study design which included…

Factors Affecting Cheating-Behavior at Undergraduate-Engineering

ERIC Educational Resources Information Center

Starovoytova, Diana; Namango, Saul

2016-01-01

This study is a fraction of a larger research on cheating in exams at the School of Engineering (SOE). The study design used a descriptive survey approach and a document analysis. A designed confidential self report questioner was applied as the main instrument for this study, with the sample size of 100 subjects, and a response rate of 95%. The…

U.S. EPA TEAM STUDY OF INHALABLE PARTICLES (PM-10): STUDY DESIGN, RESPONSE RATE, AND SAMPLER PERFORMANCE

EPA Science Inventory

The US EPA studied the exposures of 175 residents of Riverside, CA to inha1able particles (<10 u diameter) in the early fall of 1990. Participants were probabilistically selected to represent most of the Riverside nonsmoking population over the age of 10. They wore a newly-design...

Effect of high negative incidence on the performance of a centrifugal compressor stage with conventional vaned diffusers

NASA Astrophysics Data System (ADS)

Jaatinen, Ahti; Grönman, Aki; Turunen-Saaresti, Teemu; Backman, Jari

2011-06-01

Three vaned diffusers, designed to have high negative incidence (-8°) at the design operating point, are studied experimentally. The overall performance (efficiency and pressure ratio) are measured at three rotational speeds, and flow angles before and after the diffuser are measured at the design rotational speed and with three mass flow rates. The results are compared to corresponding results of the original vaneless diffuser design. Attention is paid to the performance at lower mass flows than the design mass flow. The results show that it is possible to improve the performance at mass flows lower than the design mass flow with a vaned diffuser designed with high negative incidence. However, with the vaned diffusers, the compressor still stalls at higher mass flow rates than with the vaneless one. The flow angle distributions after the diffuser are more uniform with the vaned diffusers.

Static and quasi-static analysis of lobed-pumpkin balloon

NASA Astrophysics Data System (ADS)

Nakashino, Kyoichi; Sasaki, Makoto; Hashimoto, Satoshi; Saito, Yoshitaka; Izutsu, Naoki

The present study is motivated by the need to improve design methodology for super pressure balloon with 3D gore design concept, currently being developed at the Scientific Balloon Center of ISAS/JAXA. The distinctive feature of the 3-D gore design is that the balloon film has excess materials not only in the circumferential direction but also in the meridional direction; the meridional excess is gained by attaching the film boundaries to the corresponding tendons of a shorter length with a controlled shortening rate. The resulting balloon shape is a pumpkin-like shape with large bulges formed between adjacent tendons. The balloon film, when fully inflated, develops wrinkles in the circumferential direction over its entire region, so that the stresses in the film are limited to a small amount of uniaxial tension in the circumferential direction while the high meridional loads are carried by re-enforced tendons. Naturally, the amount of wrinkling in the film is dominated by the shortening rate between the film boundaries and the tendon curve. In the 3-D gore design, as a consequence, the shortening rate becomes a fundamental design parameter along with the geometric parameters of the gore. In view of this, we have carried out a series of numerical study of the lobed-pumpkin balloon with varying gore geometry as well as with varying shortening rate. The numerical simula-tions were carried out with a nonlinear finite element code incorporating the wrinkling effect. Numerical results show that there is a threshold value for the shortening rate beyond which the stresses in the balloon film increases disproportionately. We have also carried out quasi-static simulations of the inflation process of the lobed-pumpkin balloon, and have obtained asymmetric deformations when the balloon films are in uniaxial tension state.

Design, analysis, and control of a large transport aircraft utilizing selective engine thrust as a backup system for the primary flight control. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Gerren, Donna S.

1995-01-01

A study has been conducted to determine the capability to control a very large transport airplane with engine thrust. This study consisted of the design of an 800-passenger airplane with a range of 5000 nautical miles design and evaluation of a flight control system, and design and piloted simulation evaluation of a thrust-only backup flight control system. Location of the four wing-mounted engines was varied to optimize the propulsive control capability, and the time constant of the engine response was studied. The goal was to provide level 1 flying qualities. The engine location and engine time constant did not have a large effect on the control capability. The airplane design did meet level 1 flying qualities based on frequencies, damping ratios, and time constants in the longitudinal and lateral-directional modes. Project pilots consistently rated the flying qualities as either level 1 or level 2 based on Cooper-Harper ratings. However, because of the limited control forces and moments, the airplane design fell short of meeting the time required to achieve a 30 deg bank and the time required to respond a control input.

Longevity of anterior resin-bonded bridges: survival rates of two tooth preparation designs.

PubMed

Abuzar, M; Locke, J; Burt, G; Clausen, G; Escobar, K

2018-04-16

Significant developments have occurred in the design of resin-bonded bridges (RBB) over the past two decades. They are commonly used as an alternative treatment option for a single missing tooth. The longevity of these bridges needs to be further investigated to evaluate long-term outcomes for this option to remain relevant. A cohort of patients who received anterior resin-bonded bridges (ARBB) over two decades was studied retrospectively. Longevity of 206 ARBB was assessed using Kaplan-Meier probability estimates. The two modified tooth preparation designs investigated were: (A) mesial and distal vertical grooves only; and (B) one proximal groove adjacent to the pontic and two palatal grooves. Age and gender of the patient cohort were also recorded. Overall survival rate of ARBB was 98% at 5 years, 97.2% at 10 years, and 95.1% from 12 years till 21 years. Survival curves showed minor differences when compared for the two designs, age groups and gender of ARBB recipients. Differences in the proportion of surviving bridges for design A (95.96%) and design B (98.13%) were not statistically significant (Fisher's exact test). Anterior RBB with described tooth preparation designs demonstrate a high survival rate. © 2018 Australian Dental Association.

Physicians' perception of alternative displays of clinical research evidence for clinical decision support - A study with case vignettes.

PubMed

Slager, Stacey L; Weir, Charlene R; Kim, Heejun; Mostafa, Javed; Del Fiol, Guilherme

2017-07-01

To design alternate information displays that present summaries of clinical trial results to clinicians to support decision-making; and to compare the displays according to efficacy and acceptability. A 6-between (information display presentation order) by 3-within (display type) factorial design. Two alternate displays were designed based on Information Foraging theory: a narrative summary that reduces the content to a few sentences; and a table format that structures the display according to the PICO (Population, Intervention, Comparison, Outcome) framework. The designs were compared with the summary display format available in PubMed. Physicians were asked to review five clinical studies retrieved for a case vignette; and were presented with the three display formats. Participants were asked to rate their experience with each of the information displays according to a Likert scale questionnaire. Twenty physicians completed the study. Overall, participants rated the table display more highly than either the text summary or PubMed's summary format (5.9vs. 5.4vs. 3.9 on a scale between 1 [strongly disagree] and 7 [strongly agree]). Usefulness ratings of seven pieces of information, i.e. patient population, patient age range, sample size, study arm, primary outcome, results of primary outcome, and conclusion, were high (average across all items=4.71 on a 1 to 5 scale, with 1=not at all useful and 5=very useful). Study arm, primary outcome, and conclusion scored the highest (4.9, 4.85, and 4.85 respectively). Participants suggested additional details such as rate of adverse effects. The table format reduced physicians' perceived cognitive effort when quickly reviewing clinical trial information and was more favorably received by physicians than the narrative summary or PubMed's summary format display. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessing the applicability of the Taguchi design method to an interrill erosion study

NASA Astrophysics Data System (ADS)

Zhang, F. B.; Wang, Z. L.; Yang, M. Y.

2015-02-01

Full-factorial experimental designs have been used in soil erosion studies, but are time, cost and labor intensive, and sometimes they are impossible to conduct due to the increasing number of factors and their levels to consider. The Taguchi design is a simple, economical and efficient statistical tool that only uses a portion of the total possible factorial combinations to obtain the results of a study. Soil erosion studies that use the Taguchi design are scarce and no comparisons with full-factorial designs have been made. In this paper, a series of simulated rainfall experiments using a full-factorial design of five slope lengths (0.4, 0.8, 1.2, 1.6, and 2 m), five slope gradients (18%, 27%, 36%, 48%, and 58%), and five rainfall intensities (48, 62.4, 102, 149, and 170 mm h-1) were conducted. Validation of the applicability of a Taguchi design to interrill erosion experiments was achieved by extracting data from the full dataset according to a theoretical Taguchi design. The statistical parameters for the mean quasi-steady state erosion and runoff rates of each test, the optimum conditions for producing maximum erosion and runoff, and the main effect and percentage contribution of each factor obtained from the full-factorial and Taguchi designs were compared. Both designs generated almost identical results. Using the experimental data from the Taguchi design, it was possible to accurately predict the erosion and runoff rates under the conditions that had been excluded from the Taguchi design. All of the results obtained from analyzing the experimental data for both designs indicated that the Taguchi design could be applied to interrill erosion studies and could replace full-factorial designs. This would save time, labor and costs by generally reducing the number of tests to be conducted. Further work should test the applicability of the Taguchi design to a wider range of conditions.

Comparison of Thermal Performances between Low Porosity Perforate Plate and Flat Plate Solar Air Collector

NASA Astrophysics Data System (ADS)

Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.

2018-04-01

Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.

Off-design performance analysis of MHD generator channels

NASA Technical Reports Server (NTRS)

Wilson, D. R.; Williams, T. S.

1980-01-01

A computer code for performing parametric design point calculations, and evaluating the off-design performance of MHD generators has been developed. The program is capable of analyzing Faraday, Hall, and DCW channels, including the effect of electrical shorting in the gas boundary layers and coal slag layers. Direct integration of the electrode voltage drops is included. The program can be run in either the design or off-design mode. Details of the computer code, together with results of a study of the design and off-design performance of the proposed ETF MHD generator are presented. Design point variations of pre-heat and stoichiometry were analyzed. The off-design study included variations in mass flow rate and oxygen enrichment.

Estimation of unemployment rates using small area estimation model by combining time series and cross-sectional data

NASA Astrophysics Data System (ADS)

Muchlisoh, Siti; Kurnia, Anang; Notodiputro, Khairil Anwar; Mangku, I. Wayan

2016-02-01

Labor force surveys conducted over time by the rotating panel design have been carried out in many countries, including Indonesia. Labor force survey in Indonesia is regularly conducted by Statistics Indonesia (Badan Pusat Statistik-BPS) and has been known as the National Labor Force Survey (Sakernas). The main purpose of Sakernas is to obtain information about unemployment rates and its changes over time. Sakernas is a quarterly survey. The quarterly survey is designed only for estimating the parameters at the provincial level. The quarterly unemployment rate published by BPS (official statistics) is calculated based on only cross-sectional methods, despite the fact that the data is collected under rotating panel design. The study purpose to estimate a quarterly unemployment rate at the district level used small area estimation (SAE) model by combining time series and cross-sectional data. The study focused on the application and comparison between the Rao-Yu model and dynamic model in context estimating the unemployment rate based on a rotating panel survey. The goodness of fit of both models was almost similar. Both models produced an almost similar estimation and better than direct estimation, but the dynamic model was more capable than the Rao-Yu model to capture a heterogeneity across area, although it was reduced over time.

American Recovery and Reinvestment Act of 2009: Final Report on Customer Acceptance, Retention, and Response to Time-Based Rates from Consumer Behavior Studies

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

Cappers, Peter; Scheer, Rich

Time-based rate programs, enabled by utility investments in advanced metering infrastructure (AMI), are increasingly being considered by utilities as tools to reduce peak demand and enable customers to better manage consumption and costs. Under the Smart Grid Investment Grant Program (SGIG), the U.S. Department of Energy (DOE) partnered with several electric utilities to conduct consumer behavior studies (CBS). The goals involved applying randomized and controlled experimental designs for estimating customer responses more precisely and credibly to advance understanding of time-based rates and customer systems, and provide new information for improving program designs, implementation strategies, and evaluations. The intent was tomore » produce more robust and credible analysis of impacts, costs, benefits, and lessons learned and assist utility and regulatory decision makers in evaluating investment opportunities involving time-based rates.« less

Design and operation of an anaerobic digester for waste management and fuel generation during long term lunar mission

NASA Astrophysics Data System (ADS)

Dhoble, Abhishek S.; Pullammanappallil, Pratap C.

2014-10-01

Waste treatment and management for manned long term exploratory missions to moon will be a challenge due to longer mission duration. The present study investigated appropriate digester technologies that could be used on the base. The effect of stirring, operation temperature, organic loading rate and reactor design on the methane production rate and methane yield was studied. For the same duration of digestion, the unmixed digester produced 20-50% more methane than mixed system. Two-stage design which separated the soluble components from the solids and treated them separately had more rapid kinetics than one stage system, producing the target methane potential in one-half the retention time than the one stage system. The two stage system degraded 6% more solids than the single stage system. The two stage design formed the basis of a prototype digester sized for a four-person crew during one year exploratory lunar mission.

Computational analysis and preliminary redesign of the nozzle contour of the Langley hypersonic CF4 tunnel

NASA Technical Reports Server (NTRS)

Thompson, R. A.; Sutton, Kenneth

1987-01-01

A computational analysis, modification, and preliminary redesign study was performed on the nozzle contour of the Langley Hypersonic CF4 Tunnel. This study showed that the existing nozzle was contoured incorrectly for the design operating condition, and this error was shown to produce the measured disturbances in the exit flow field. A modified contour was designed for the current nozzle downstream of the maximum turning point that would provide a uniform exit flow. New nozzle contours were also designed for an exit Mach number and Reynolds number combination which matches that attainable in the Langley 20-Inch Mach 6 Tunnel. Two nozzle contours were designed: one having the same exit radius but a larger mass flow rate than that of the existing CF4 Tunnel, and the other having the same mass flow rate but a smaller exit radius than that of the existing CF4 Tunnel.

Possibilities to improve the aircraft interior comfort experience.

PubMed

Vink, P; Bazley, C; Kamp, I; Blok, M

2012-03-01

Comfort plays an increasingly important role in the interior design of airplanes. Although ample research has been conducted on airplane design technology, only a small amount of public scientific information is available addressing the passenger's opinion. In this study, more than 10,000 internet trip reports and 153 passenger interviews were used to gather opinions about aspects which need to be improved in order to design a more comfortable aircraft interior. The results show clear relationships between comfort and legroom, hygiene, crew attention and seat/personal space. Passengers rate the newer planes significantly better than older ones, indicating that attention to design for comfort has proven effective. The study also shows that rude flight attendants and bad hygiene reduce the comfort experience drastically and that a high comfort rating is related to higher "fly again" values. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Programmable rate modem utilizing digital signal processing techniques

NASA Technical Reports Server (NTRS)

Bunya, George K.; Wallace, Robert L.

1989-01-01

The engineering development study to follow was written to address the need for a Programmable Rate Digital Satellite Modem capable of supporting both burst and continuous transmission modes with either binary phase shift keying (BPSK) or quadrature phase shift keying (QPSK) modulation. The preferred implementation technique is an all digital one which utilizes as much digital signal processing (DSP) as possible. Here design tradeoffs in each portion of the modulator and demodulator subsystem are outlined, and viable circuit approaches which are easily repeatable, have low implementation losses and have low production costs are identified. The research involved for this study was divided into nine technical papers, each addressing a significant region of concern in a variable rate modem design. Trivial portions and basic support logic designs surrounding the nine major modem blocks were omitted. In brief, the nine topic areas were: (1) Transmit Data Filtering; (2) Transmit Clock Generation; (3) Carrier Synthesizer; (4) Receive AGC; (5) Receive Data Filtering; (6) RF Oscillator Phase Noise; (7) Receive Carrier Selectivity; (8) Carrier Recovery; and (9) Timing Recovery.

Early subsidence of shape-closed hip arthroplasty stems is associated with late revision. A systematic review and meta-analysis of 24 RSA studies and 56 survival studies.

PubMed

van der Voort, Paul; Pijls, Bart G; Nieuwenhuijse, Marc J; Jasper, Jorrit; Fiocco, Marta; Plevier, Josepha W M; Middeldorp, Saskia; Valstar, Edward R; Nelissen, Rob G H H

2015-01-01

Few studies have addressed the association between early migration of femoral stems and late aseptic revision in total hip arthroplasty. We performed a meta-regression analysis on 2 parallel systematic reviews and meta-analyses to determine the association between early migration and late aseptic revision of femoral stems. Of the 2 reviews, one covered early migration data obtained from radiostereometric analysis (RSA) studies and the other covered long-term aseptic revision rates obtained from survival studies with endpoint revision for aseptic loosening. Stems were stratified according to the design concept: cemented shape-closed, cemented force-closed, and uncemented. A weighted regression model was used to assess the association between early migration and late aseptic revision, and to correct for confounders. Thresholds for acceptable and unacceptable migration were determined in accordance with the national joint registries (≤ 5% revision at 10 years) and the NICE criteria (≤ 10% revision at 10 years). 24 studies (731 stems) were included in the RSA review and 56 studies (20,599 stems) were included in the survival analysis review. Combining both reviews for the 3 design concepts showed that for every 0.1-mm increase in 2-year subsidence, as measured with RSA, there was a 4% increase in revision rate for the shape-closed stem designs. This association remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. The threshold for acceptable migration of shape-closed designs was defined at 0.15 mm; stems subsiding less than 0.15 mm in 2 years had revision rates of less than 5% at 10 years, while stems exceeding 0.15 mm subsidence had revision rates of more than 5%. There was a clinically relevant association between early subsidence of shape-closed femoral stems and late revision for aseptic loosening. This association can be used to assess the safety of shape-closed stem designs. The published research is not sufficient to allow us to make any conclusions regarding such an association for the force-closed and uncemented stems.

Mixed oxidizer hybrid propulsion system optimization under uncertainty using applied response surface methodology and Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Whitehead, James Joshua

The analysis documented herein provides an integrated approach for the conduct of optimization under uncertainty (OUU) using Monte Carlo Simulation (MCS) techniques coupled with response surface-based methods for characterization of mixture-dependent variables. This novel methodology provides an innovative means of conducting optimization studies under uncertainty in propulsion system design. Analytic inputs are based upon empirical regression rate information obtained from design of experiments (DOE) mixture studies utilizing a mixed oxidizer hybrid rocket concept. Hybrid fuel regression rate was selected as the target response variable for optimization under uncertainty, with maximization of regression rate chosen as the driving objective. Characteristic operational conditions and propellant mixture compositions from experimental efforts conducted during previous foundational work were combined with elemental uncertainty estimates as input variables. Response surfaces for mixture-dependent variables and their associated uncertainty levels were developed using quadratic response equations incorporating single and two-factor interactions. These analysis inputs, response surface equations and associated uncertainty contributions were applied to a probabilistic MCS to develop dispersed regression rates as a function of operational and mixture input conditions within design space. Illustrative case scenarios were developed and assessed using this analytic approach including fully and partially constrained operational condition sets over all of design mixture space. In addition, optimization sets were performed across an operationally representative region in operational space and across all investigated mixture combinations. These scenarios were selected as representative examples relevant to propulsion system optimization, particularly for hybrid and solid rocket platforms. Ternary diagrams, including contour and surface plots, were developed and utilized to aid in visualization. The concept of Expanded-Durov diagrams was also adopted and adapted to this study to aid in visualization of uncertainty bounds. Regions of maximum regression rate and associated uncertainties were determined for each set of case scenarios. Application of response surface methodology coupled with probabilistic-based MCS allowed for flexible and comprehensive interrogation of mixture and operating design space during optimization cases. Analyses were also conducted to assess sensitivity of uncertainty to variations in key elemental uncertainty estimates. The methodology developed during this research provides an innovative optimization tool for future propulsion design efforts.

Study of a Satellite Attitude Control System Using Integrating Gyros as Torque Sources

NASA Technical Reports Server (NTRS)

White, John S.; Hansen, Q. Marion

1961-01-01

This report considers the use of single-degree-of-freedom integrating gyros as torque sources for precise control of satellite attitude. Some general design criteria are derived and applied to the specific example of the Orbiting Astronomical Observatory. The results of the analytical design are compared with the results of an analog computer study and also with experimental results from a low-friction platform. The steady-state and transient behavior of the system, as determined by the analysis, by the analog study, and by the experimental platform agreed quite well. The results of this study show that systems using integrating gyros for precise satellite attitude control can be designed to have a reasonably rapid and well-damped transient response, as well as very small steady-state errors. Furthermore, it is shown that the gyros act as rate sensors, as well as torque sources, so that no rate stabilization networks are required, and when no error sensor is available, the vehicle is still rate stabilized. Hence, it is shown that a major advantage of a gyro control system is that when the target is occulted, an alternate reference is not required.

A study of usability principles and interface design for mobile e-books.

PubMed

Wang, Chao-Ming; Huang, Ching-Hua

2015-01-01

This study examined usability principles and interface designs in order to understand the relationship between the intentions of mobile e-book interface designs and users' perceptions. First, this study summarised 4 usability principles and 16 interface attributes, in order to conduct usability testing and questionnaire survey by referring to Nielsen (1993), Norman (2002), and Yeh (2010), who proposed the usability principles. Second, this study used the interviews to explore the perceptions and behaviours of user operations through senior users of multi-touch prototype devices. The results of this study are as follows: (1) users' behaviour of operating an interactive interface is related to user prior experience; (2) users' rating of the visibility principle is related to users' subjective perception but not related to user prior experience; however, users' ratings of the ease, efficiency, and enjoyment principles are related to user prior experience; (3) the interview survey reveals that the key attributes affecting users' behaviour of operating an interface include aesthetics, achievement, and friendliness. This study conducts experiments to explore the effects of users’ prior multi-touch experience on users’ behaviour of operating a mobile e-book interface and users’ rating of usability principles. Both qualitative and quantitative data analyses were performed. By applying protocol analysis, key attributes affecting users’ behaviour of operation were determined.

Aviation Electronics Technician 3 and 2. Rate Training Manual.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

The manual is designed as a self-study text for use by personnel of the Navy and Naval Reserve who are preparing to meet professional requirements for advancement in the rating of Aviation Electronics Technician. The document opens with a review of leadership and qualifications for the Aviation Electronics Technician rating. Other chapters cover…

Working with Sparse Data in Rated Language Tests: Generalizability Theory Applications

ERIC Educational Resources Information Center

Lin, Chih-Kai

2017-01-01

Sparse-rated data are common in operational performance-based language tests, as an inevitable result of assigning examinee responses to a fraction of available raters. The current study investigates the precision of two generalizability-theory methods (i.e., the rating method and the subdividing method) specifically designed to accommodate the…

Engineering Aid 3 & 2, Vol. 1. Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Naval Education and Training Command, Washington, DC.

Designed for individual study and not formal classroom instruction, this rate training manual provides subject matter that relates directly to the occupational qualifications of the Engineering Aid (EA) rating. This eight-chapter volume focuses on administrative matters, mathematics, and basic drafting. Chapter 1 discusses the scope of the EA…

Dressed to Present: Ratings of Classroom Presentations Vary with Attire

ERIC Educational Resources Information Center

Gurung, Regan A. R.; Kempen, Laura; Klemm, Kayla; Senn, Rebecca; Wysocki, Rosie

2014-01-01

This study investigates the effects of formality of dress on ratings of classroom presentations. Participants (N = 65, 66% women) from a Midwestern university in the United States rated three female students giving a presentation designed for a health psychology class in one of four outfits: casual, party, business casual, or business formal.…

Engineering Aid 3 & 2, Vol. 2. Rate Training Manual.

ERIC Educational Resources Information Center

Bernal, Benito C., Jr.

Designed for individual study and not formal classroom instruction, this rate training manual provides subject matter that relates directly to the occupational qualifications of the Engineering Aid (EA) rating. This volume contains 10 chapters which deal with: (1) wood and light frame structures (examining the uses, kinds, sizes, and grades of…

Improving the Quality of Education by Identifying Effective Television Teachers. Final Report.

ERIC Educational Resources Information Center

Myers, Lawrence, Jr.

A project designed to develop a television teacher rating instrument, and to study relationships between ratings of teachers, measures of student personality, and student reports of mood associated with instruction utilized over 2,300 undergraduates: 618 of them described an ideal teacher on an adjectival rating scale and the remainder rated…

A Case Study in CAD Design Automation

ERIC Educational Resources Information Center

Lowe, Andrew G.; Hartman, Nathan W.

2011-01-01

Computer-aided design (CAD) software and other product life-cycle management (PLM) tools have become ubiquitous in industry during the past 20 years. Over this time they have continuously evolved, becoming programs with enormous capabilities, but the companies that use them have not evolved their design practices at the same rate. Due to the…

Neighborhood design and rates of walking and biking to elementary school in 34 California communities.

PubMed

Braza, Mark; Shoemaker, Wendy; Seeley, Anne

2004-01-01

This study evaluates the relationship between neighborhood design and rates of students walking and biking to elementary school. Pairwise correlations and multiple regression models were estimated based on a cross-sectional study of elementary schools and their surrounding neighborhoods. Setting and Subjects. Thirty-four (23%) of 150 California public elementary schools holding October 1999 Walk to School Day events participated in the study. Teachers asked fifth-grade students how they arrived to school 1 week before Walk to School Day. 1990 U.S. Census data measured population density and number of intersections per street mile, whereas 1998-1999 California Department of Education data measured school size, the percentage of students receiving public welfare, and the percentage of students of various ethnicities. Population density (p = .000) and school size (p = .053) were significantly associated with walking and biking rates in regression models controlling for number of intersections per street mile, the percentage of students receiving public welfare, and the percentage of students of various ethnicities. The number of intersections per street mile was associated with walking and biking rates in pairwise correlations (p = .003) but not in regression models. The results support the hypothesis that the walking and biking rates are higher in denser neighborhoods and to smaller schools but do not support the hypothesis that rates are higher in neighborhoods with a high number of intersections per street mile. We suggest that detailed data for a larger sample of students would allow statistical models to isolate the effect of specific design characteristics.

Deep nets vs expert designed features in medical physics: An IMRT QA case study.

PubMed

Interian, Yannet; Rideout, Vincent; Kearney, Vasant P; Gennatas, Efstathios; Morin, Olivier; Cheung, Joey; Solberg, Timothy; Valdes, Gilmer

2018-03-30

The purpose of this study was to compare the performance of Deep Neural Networks against a technique designed by domain experts in the prediction of gamma passing rates for Intensity Modulated Radiation Therapy Quality Assurance (IMRT QA). A total of 498 IMRT plans across all treatment sites were planned in Eclipse version 11 and delivered using a dynamic sliding window technique on Clinac iX or TrueBeam Linacs. Measurements were performed using a commercial 2D diode array, and passing rates for 3%/3 mm local dose/distance-to-agreement (DTA) were recorded. Separately, fluence maps calculated for each plan were used as inputs to a convolution neural network (CNN). The CNNs were trained to predict IMRT QA gamma passing rates using TensorFlow and Keras. A set of model architectures, inspired by the convolutional blocks of the VGG-16 ImageNet model, were constructed and implemented. Synthetic data, created by rotating and translating the fluence maps during training, was created to boost the performance of the CNNs. Dropout, batch normalization, and data augmentation were utilized to help train the model. The performance of the CNNs was compared to a generalized Poisson regression model, previously developed for this application, which used 78 expert designed features. Deep Neural Networks without domain knowledge achieved comparable performance to a baseline system designed by domain experts in the prediction of 3%/3 mm Local gamma passing rates. An ensemble of neural nets resulted in a mean absolute error (MAE) of 0.70 ± 0.05 and the domain expert model resulted in a 0.74 ± 0.06. Convolutional neural networks (CNNs) with transfer learning can predict IMRT QA passing rates by automatically designing features from the fluence maps without human expert supervision. Predictions from CNNs are comparable to a system carefully designed by physicist experts. © 2018 American Association of Physicists in Medicine.

A Survey of Student Perspectives toward Faculty Evaluations

ERIC Educational Resources Information Center

Slocombe, Tom; Miller, Donald; Hite, Nancy

2011-01-01

This study was designed to help faculty and administrators weigh the value of using student ratings of professors' teaching effectiveness and to determine factors that may affect those ratings. For this study, conducted at a Midwestern AACSB accredited School of Business, 163 students (23% of the business majors) were surveyed to determine their…

Sweating rates of dairy cows and beef heifers in hot conditions

USDA-ARS?s Scientific Manuscript database

Sweating rates from heat-stressed dairy and feedlot cows were measured using a “Portable Calorimeter” and a “Bovine Evaporation Meter” designed and fabricated for the studies reported herein. Measurements were taken when cows were in their natural habitat. The focus of the study was to compare swea...

The Relationship between ISO 9000 Participation and Educational Outcomes of Schools

ERIC Educational Resources Information Center

Bae, Sang Hoon

2007-01-01

Purpose: The study seeks to examine the relationship between the implementation of the ISO 9000 quality management system and educational outcomes of schools, measured by student achievement on the state-mandated tests and school attendance rates--graduation rates, in the case of high schools. Design/methodology/approach: The study was conducted…

Ethnic Differences in Completion Rates as a Function of School Size in Texas High Schools

ERIC Educational Resources Information Center

Fitzgerald, Kim; Gordon, Teandra; Canty, Antoinette; Stitt, Ruth E.; Onwuegbuzie, Anthony J.; Frels, Rebecca K.

2013-01-01

The purpose of this study was to investigate differences in high school completion rates among White, African American, and Hispanic students enrolled in different school sizes--small, medium, and large. For this causal-comparative research design, this study utilized archival data from the Texas Education Association's Academic Excellence…

Esophageal cancer: 5-year survival rate at south-east of Caspian sea of northern Iran.

PubMed

Taziki, Mohammad Hussin; Rajaee, Siamak; Behnampour, Naser; Tadrisee, Massoud; Mansourian, Azad Reza

2011-01-01

Locating at southern margin of Caspian sea and Asian esophagus cancer cordon Golestan state is one of the most common sites of this cancer. This study designed to evaluate the 5-years survival rate of esophagus cancer. 55 patients with esophagus cancer diagnosed by pathologic examination, age, gender, type of tumor, clinical manifestation on the time of tumor metastases, treatment and patient survival time studied. The collecting data were analyzed by SPSS 11.5, and life table and Kaplan Meier methods were applied. 55 patients studied included 11 females and 44 males respectively with average survival life time of 12.8 months for the 5-year survival rate for patients diagnosed at early stage was 0.025, patients with systemic symptoms such as weight loss was 0.00. Far metastases adverse effect on highest survivals was observed among patients who underwent surgery; the survival rate for such patients was about 0.014. Esophageal cancer is high in southern margin of Caspian Sea, it is suggested to design studies to find the probable risk factors and the screening tests for on-time diagnosis.

Factorial study of rain garden design for nitrogen removal

EPA Science Inventory

Abstract Nitrate (〖NO〗_3^--N ) removal studies in bioretention systems showed great variability in removal rates and in some cases 〖NO〗_3^--N was exported. A 3-way factorial design (2 x 2 x 4) was devised for eight outdoor un-vegetated rain gardens to evaluate the effects of ...

Perception of Women in Magazine Advertising.

ERIC Educational Resources Information Center

Rossi, Susan R.; Rossi, Joseph S.

Advertising research has indicated that a high degree of sexism toward women occurs in magazine and television advertising. However, the design of such marketing studies is different from the designs typically used in most psychological research. An experimental approach was used for a study in which 137 college students rated 10 control and 10…

Testing a biofilter cover design to mitigate dairy effluent pond methane emissions.

PubMed

Pratt, Chris; Deslippe, Julie; Tate, Kevin R

2013-01-02

Biofiltration, whereby CH(4) is oxidized by methanotrophic bacteria, is a potentially effective strategy for mitigating CH(4) emissions from anaerobic dairy effluent lagoons/ponds, which typically produce insufficient biogas for energy recovery. This study reports on the effectiveness of a biofilter cover design at oxidizing CH(4) produced by dairy effluent ponds. Three substrates, a volcanic pumice soil, a garden-waste compost, and a mixture of the two, were tested as media for the biofilters. All substrates were suspended as 5 cm covers overlying simulated dairy effluent ponds. Methane fluxes supplied to the filters were commensurate with emission rates from typical dairy effluent ponds. All substrates oxidized more than 95% of the CH(4) influx (13.9 g CH(4) m(-3) h(-1)) after two months and continued to display high oxidation rates for the remaining one month of the trial. The volcanic soil biofilters exhibited the highest oxidation rates (99% removal). When the influx CH(4) dose was doubled for a month, CH(4) removal rates remained >90% for all substrates (maximum = 98%, for the volcanic soil), suggesting that biofilters have a high capacity to respond to increases in CH(4) loads. Nitrous oxide emissions from the biofilters were negligible (maximum = 19.9 mg N(2)O m(-3) h(-1)) compared with CH(4) oxidation rates, particularly from the volcanic soil that had a much lower microbial-N (75 mg kg(-1)) content than the compost-based filters (>240 mg kg(-1)). The high and sustained CH(4) oxidation rates observed in this laboratory study indicate that a biofilter cover design is a potentially efficient method to mitigate CH(4) emissions from dairy effluent ponds. The design should now be tested under field conditions.

Using Generalizability Theory to Examine the Dependability of Scores from the Learning Target Rating Scale

ERIC Educational Resources Information Center

McLaughlin, Tara W.; Snyder, Patricia A.; Algina, James

2017-01-01

The Learning Target Rating Scale (LTRS) is a measure designed to evaluate the quality of teacher-developed learning targets for embedded instruction for early learning. In the present study, we examined the measurement dependability of LTRS scores by conducting a generalizability study (G-study). We used a partially nested, three-facet model to…

A Comparison of Rubrics and Graded Category Rating Scales with Various Methods Regarding Raters' Reliability

ERIC Educational Resources Information Center

Dogan, C. Deha; Uluman, Müge

2017-01-01

The aim of this study was to determine the extent at which graded-category rating scales and rubrics contribute to inter-rater reliability. The research was designed as a correlational study. Study group consisted of 82 students attending sixth grade and three writing course teachers in a private elementary school. A performance task was…

Methodological survey of designed uneven randomization trials (DU-RANDOM): a protocol.

PubMed

Wu, Darong; Akl, Elie A; Guyatt, Gordon H; Devereaux, Philip J; Brignardello-Petersen, Romina; Prediger, Barbara; Patel, Krupesh; Patel, Namrata; Lu, Taoying; Zhang, Yuan; Falavigna, Maicon; Santesso, Nancy; Mustafa, Reem A; Zhou, Qi; Briel, Matthias; Schünemann, Holger J

2014-01-23

Although even randomization (that is, approximately 1:1 randomization ratio in study arms) provides the greatest statistical power, designed uneven randomization (DUR), (for example, 1:2 or 1:3) is used to increase participation rates. Until now, no convincing data exists addressing the impact of DUR on participation rates in trials. The objective of this study is to evaluate the epidemiology and to explore factors associated with DUR. We will search for reports of RCTs published within two years in 25 general medical journals with the highest impact factor according to the Journal Citation Report (JCR)-2010. Teams of two reviewers will determine eligibility and extract relevant information from eligible RCTs in duplicate and using standardized forms. We will report the prevalence of DUR trials, the reported reasons for using DUR, and perform a linear regression analysis to estimate the association between the randomization ratio and the associated factors, including participation rate, type of informed consent, clinical area, and so on. A clearer understanding of RCTs with DUR and its association with factors in trials, for example, participation rate, can optimize trial design and may have important implications for both researchers and users of the medical literature.

An Analysis of the Autorotative Performance of a Helicopter Powered by Rotor-Tip Jet Units

NASA Technical Reports Server (NTRS)

Gessow, Alfred

1950-01-01

The autorotative performance of an assumed helicopter was studied to determine the effect of inoperative jet units located at the rotor-blade tip on the helicopter rate of descent. For a representative ramjet design, the effect of the jet drag is to increase the minimum rate of descent of the helicopter from about 1,OO feet per minute to 3,700 feet per minute when the rotor is operating at a tip speed of approximately 600 feet per second. The effect is less if the rotor operates at lower tip speeds, but the rotor kinetic energy and the stall margin available for the landing maneuver are then reduced. Power-off rates of descent of pulse-jet helicopters would be expected to be less than those of ramjet. helicopters because pulse jets of current design appear to have greater ratios of net power-on thrust to power-off, drag than currently designed rain jets. Iii order to obtain greater accuracy in studies of autorotative performance, calculations in'volving high power-off rates of descent should include the weight-supporting effect of the fuselage parasite-drag force and the fact that the rotor thrust does not equal the weight of the helicopter.

Witnessing of Cheating-in-Exams Behavior and Factors Sustaining Integrity

ERIC Educational Resources Information Center

Starovoytova, Diana; Arimi, Milton

2017-01-01

This study is a fraction of a larger research on cheating, at the School of Engineering (SOE). The study design used a descriptive survey approach and a document analysis. A designed confidential self-report questioner was used as the main instrument, for this study, with the sample size of 100 subjects and response rate of 95%. The tool was…

Evaluating the utility of two gestural discomfort evaluation methods

PubMed Central

Son, Minseok; Jung, Jaemoon; Park, Woojin

2017-01-01

Evaluating physical discomfort of designed gestures is important for creating safe and usable gesture-based interaction systems; yet, gestural discomfort evaluation has not been extensively studied in HCI, and few evaluation methods seem currently available whose utility has been experimentally confirmed. To address this, this study empirically demonstrated the utility of the subjective rating method after a small number of gesture repetitions (a maximum of four repetitions) in evaluating designed gestures in terms of physical discomfort resulting from prolonged, repetitive gesture use. The subjective rating method has been widely used in previous gesture studies but without empirical evidence on its utility. This study also proposed a gesture discomfort evaluation method based on an existing ergonomics posture evaluation tool (Rapid Upper Limb Assessment) and demonstrated its utility in evaluating designed gestures in terms of physical discomfort resulting from prolonged, repetitive gesture use. Rapid Upper Limb Assessment is an ergonomics postural analysis tool that quantifies the work-related musculoskeletal disorders risks for manual tasks, and has been hypothesized to be capable of correctly determining discomfort resulting from prolonged, repetitive gesture use. The two methods were evaluated through comparisons against a baseline method involving discomfort rating after actual prolonged, repetitive gesture use. Correlation analyses indicated that both methods were in good agreement with the baseline. The methods proposed in this study seem useful for predicting discomfort resulting from prolonged, repetitive gesture use, and are expected to help interaction designers create safe and usable gesture-based interaction systems. PMID:28423016

Clinical Evaluation of Kshara sutra Therapy in the management of Bhagandara( Fistula- in-Ano)- A prospective study

PubMed Central

Panigrahi, Hemanta Kumar; Rani, Rakesh; Padhi, M.M.; Lavekar, G.S.

2009-01-01

Study design: A prospective study of 50 patients suffering from Bhagandara(Fistula in Ano) (age ranging from 18-54years) treated by Kshara sutra therapy Place: Kshara sutra unit, Central research Unit, Punjabi bagh, New Delhi Duration: January 2007 to July 2008. Objectives: To determine the incidence of low or high anal fistula, recurrence rate following Kshara sutra therapy and effect of Ksharasutra therapy on the Bhagandara. Material and methods: The fifty patients (50) were selected randomly in the Out Patient Department. Study Design: Uncontrolled open level Study. Results: Patients were followed to see the incidence of recurrence, effect of Kshara Sutra Therapy on incontinence. Overall recurrence rate was only 5.88 %. Minor incontinence was observed only following Kshara sutra Therapy for high variety for which no treatment was given. No such complication occurred in low variety. Conclusion: Bhagandara (Fistula in Ano) can be treated by Kshara Sutra Therapy with minimal loss of sphincter muscle and low reoccurrence rate. PMID:22557318

QFD-ANP Approach for the Conceptual Design of Research Vessels: A Case Study

NASA Astrophysics Data System (ADS)

Venkata Subbaiah, Kambagowni; Yeshwanth Sai, Koneru; Suresh, Challa

2016-10-01

Conceptual design is a subset of concept art wherein a new idea of product is created instead of a visual representation which would directly be used in a final product. The purpose is to understand the needs of conceptual design which are being used in engineering designs and to clarify the current conceptual design practice. Quality function deployment (QFD) is a customer oriented design approach for developing new or improved products and services to enhance customer satisfaction. House of quality (HOQ) has been traditionally used as planning tool of QFD which translates customer requirements (CRs) into design requirements (DRs). Factor analysis is carried out in order to reduce the CR portions of HOQ. The analytical hierarchical process is employed to obtain the priority ratings of CR's which are used in constructing HOQ. This paper mainly discusses about the conceptual design of an oceanographic research vessel using analytical network process (ANP) technique. Finally the QFD-ANP integrated methodology helps to establish the importance ratings of DRs.

Design of mechanical arm for an automatic sorting system of recyclable cans

NASA Astrophysics Data System (ADS)

Resti, Y.; Mohruni, A. S.; Burlian, F.; Yani, I.; Amran, A.

2018-04-01

The use of a mechanical arm for an automatic sorting system of used cans should be designed carefully. The right design will result in a high precision sorting rate and a short sorting time. The design includes first; design manipulator,second; determine link and joint specifications, and third; build mechanical systems and control systems. This study aims to design the mechanical arm as a hardware system for automatic cans sorting system. The material used for the manipulator is the aluminum plate. The manipulator is designed using 6 links and 6 join where the 6th link is the end effectorand the 6th join is the gripper. As a driving motor used servo motor, while as a microcontroller used Arduino Uno which is connected with Matlab programming language. Based on testing, a mechanical arm designed for this recyclable canned recycling system has a precision sorting rate at 93%, where the average total time required for sorting is 10.82 seconds.

Variable slew-rate spiral design: theory and application to peak B(1) amplitude reduction in 2D RF pulse design.

PubMed

Xu, Dan; King, Kevin F; Liang, Zhi-Pei

2007-10-01

A new class of spiral trajectories called variable slew-rate spirals is proposed. The governing differential equations for a variable slew-rate spiral are derived, and both numeric and analytic solutions to the equations are given. The primary application of variable slew-rate spirals is peak B(1) amplitude reduction in 2D RF pulse design. The reduction of peak B(1) amplitude is achieved by changing the gradient slew-rate profile, and gradient amplitude and slew-rate constraints are inherently satisfied by the design of variable slew-rate spiral gradient waveforms. A design example of 2D RF pulses is given, which shows that under the same hardware constraints the RF pulse using a properly chosen variable slew-rate spiral trajectory can be much shorter than that using a conventional constant slew-rate spiral trajectory, thus having greater immunity to resonance frequency offsets.

Hydrodynamic Assists Magnetophoreses Rare Cancer cells Separation in Microchannel Simulation and Experimental Verifications

NASA Astrophysics Data System (ADS)

Saeed, O.; Duru, L.; Yulin, D.

2018-05-01

A proposed microfluidic design has been fabricated and simulated using COMSOL Multiphysics software, based on two physical models included in this design. The device’s ability to create a narrow stream of the core sample by controlling the sheath flow rates Qs1 and Qs2 in both peripheral channels was investigated. The main target of this paper is to study the possibility of combing the hydrodynamic and magnetic techniques, in order to achieve a high rate of cancer cells separation from a cell mixture and/or buffer sample. The study has been conducted in two stages, firstly, the effects of the sheath flow rates (Qs1 and Qs2) on the sample stream focusing were studied, to find the proposed device effectiveness optimal conditions and its capability in cell focusing, and then the magnetic mechanism has been utilized to finalize the pre-labelled cells separation process.

A two-stage design for multiple testing in large-scale association studies.

PubMed

Wen, Shu-Hui; Tzeng, Jung-Ying; Kao, Jau-Tsuen; Hsiao, Chuhsing Kate

2006-01-01

Modern association studies often involve a large number of markers and hence may encounter the problem of testing multiple hypotheses. Traditional procedures are usually over-conservative and with low power to detect mild genetic effects. From the design perspective, we propose a two-stage selection procedure to address this concern. Our main principle is to reduce the total number of tests by removing clearly unassociated markers in the first-stage test. Next, conditional on the findings of the first stage, which uses a less stringent nominal level, a more conservative test is conducted in the second stage using the augmented data and the data from the first stage. Previous studies have suggested using independent samples to avoid inflated errors. However, we found that, after accounting for the dependence between these two samples, the true discovery rate increases substantially. In addition, the cost of genotyping can be greatly reduced via this approach. Results from a study of hypertriglyceridemia and simulations suggest the two-stage method has a higher overall true positive rate (TPR) with a controlled overall false positive rate (FPR) when compared with single-stage approaches. We also report the analytical form of its overall FPR, which may be useful in guiding study design to achieve a high TPR while retaining the desired FPR.

Observational Studies: Cohort and Case-Control Studies

PubMed Central

Song, Jae W.; Chung, Kevin C.

2010-01-01

Observational studies are an important category of study designs. To address some investigative questions in plastic surgery, randomized controlled trials are not always indicated or ethical to conduct. Instead, observational studies may be the next best method to address these types of questions. Well-designed observational studies have been shown to provide results similar to randomized controlled trials, challenging the belief that observational studies are second-rate. Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures. In this review article, we describe these study designs, methodological issues, and provide examples from the plastic surgery literature. PMID:20697313

Decreasing-Rate Pruning Optimizes the Construction of Efficient and Robust Distributed Networks.

PubMed

Navlakha, Saket; Barth, Alison L; Bar-Joseph, Ziv

2015-07-01

Robust, efficient, and low-cost networks are advantageous in both biological and engineered systems. During neural network development in the brain, synapses are massively over-produced and then pruned-back over time. This strategy is not commonly used when designing engineered networks, since adding connections that will soon be removed is considered wasteful. Here, we show that for large distributed routing networks, network function is markedly enhanced by hyper-connectivity followed by aggressive pruning and that the global rate of pruning, a developmental parameter not previously studied by experimentalists, plays a critical role in optimizing network structure. We first used high-throughput image analysis techniques to quantify the rate of pruning in the mammalian neocortex across a broad developmental time window and found that the rate is decreasing over time. Based on these results, we analyzed a model of computational routing networks and show using both theoretical analysis and simulations that decreasing rates lead to more robust and efficient networks compared to other rates. We also present an application of this strategy to improve the distributed design of airline networks. Thus, inspiration from neural network formation suggests effective ways to design distributed networks across several domains.

Decreasing-Rate Pruning Optimizes the Construction of Efficient and Robust Distributed Networks

PubMed Central

Navlakha, Saket; Barth, Alison L.; Bar-Joseph, Ziv

2015-01-01

Robust, efficient, and low-cost networks are advantageous in both biological and engineered systems. During neural network development in the brain, synapses are massively over-produced and then pruned-back over time. This strategy is not commonly used when designing engineered networks, since adding connections that will soon be removed is considered wasteful. Here, we show that for large distributed routing networks, network function is markedly enhanced by hyper-connectivity followed by aggressive pruning and that the global rate of pruning, a developmental parameter not previously studied by experimentalists, plays a critical role in optimizing network structure. We first used high-throughput image analysis techniques to quantify the rate of pruning in the mammalian neocortex across a broad developmental time window and found that the rate is decreasing over time. Based on these results, we analyzed a model of computational routing networks and show using both theoretical analysis and simulations that decreasing rates lead to more robust and efficient networks compared to other rates. We also present an application of this strategy to improve the distributed design of airline networks. Thus, inspiration from neural network formation suggests effective ways to design distributed networks across several domains. PMID:26217933

High-speed machining of Space Shuttle External Tank (ET) panels

NASA Technical Reports Server (NTRS)

Miller, J. A.

1983-01-01

Potential production rates and project cost savings achieved by converting the conventional machining process in manufacturing shuttle external tank panels to high speed machining (HSM) techniques were studied. Savings were projected from the comparison of current production rates with HSM rates and with rates attainable on new conventional machines. The HSM estimates were also based on rates attainable by retrofitting existing conventional equipment with high speed spindle motors and rates attainable using new state of the art machines designed and built for HSM.

Evaluating sediment capture rates for different sediment basin designs.

DOT National Transportation Integrated Search

2007-08-01

The effectiveness of sediment control devices was studied on a large NC DOT project to determine the : effects of different designs and conditions. Flow and sediment content of water exiting six different traps : and basins were measured and the amou...

CFD Design and Analysis of a Passively Suspended Tesla Pump Left Ventricular Assist Device

PubMed Central

Medvitz, Richard B.; Boger, David A.; Izraelev, Valentin; Rosenberg, Gerson; Paterson, Eric G.

2012-01-01

This paper summarizes the use of computational fluid dynamics (CFD) to design a novelly suspended Tesla LVAD. Several design variants were analyzed to study the parameters affecting device performance. CFD was performed at pump speeds of 6500, 6750 and 7000 RPM and at flow rates varying from 3 to 7 liter-per-minute (LPM). The CFD showed that shortening the plates nearest the pump inlet reduced the separations formed beneath the upper plate leading edges and provided a more uniform flow distribution through the rotor gaps, both of which positively affected the device hydrodynamic performance. The final pump design was found to produce a head rise of 77 mmHg with a hydraulic efficiency of 16% at the design conditions of 6 LPM throughflow and a 6750 RPM rotation rate. To assess the device hemodynamics the strain rate fields were evaluated. The wall shear stresses demonstrated that the pump wall shear stresses were likely adequate to inhibit thrombus deposition. Finally, an integrated field hemolysis model was applied to the CFD results to assess the effects of design variation and operating conditions on the device hemolytic performance. PMID:21595722

Pioneer spacecraft operation at low and high spin rates

NASA Technical Reports Server (NTRS)

1973-01-01

The feasibility of executing major changes upward or downward from the nominal spin rate for which the Pioneer F&G spacecraft was designed was investigated along with the extent of system and subsystem modifications required to implement these mode changes in future spacecraft evolving from the baseline Pioneer F and G. Results of a previous study are re-examined and updated for an extended range of spin rate variations for missions that include outer planet orbiters, outer planet flyby and outer planet probe delivery. However, in the interest of design simplicity and cost economy, major modifications of the baseline Pioneer system and subsystem concept were avoided.

2008 United States National Seismic Hazard Maps

USGS Publications Warehouse

Petersen, M.D.; ,

2008-01-01

The U.S. Geological Survey recently updated the National Seismic Hazard Maps by incorporating new seismic, geologic, and geodetic information on earthquake rates and associated ground shaking. The 2008 versions supersede those released in 1996 and 2002. These maps are the basis for seismic design provisions of building codes, insurance rate structures, earthquake loss studies, retrofit priorities, and land-use planning. Their use in design of buildings, bridges, highways, and critical infrastructure allows structures to better withstand earthquake shaking, saving lives and reducing disruption to critical activities following a damaging event. The maps also help engineers avoid costs from over-design for unlikely levels of ground motion.

Fireman: Naval Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Naval Education and Training Command, Pensacola, FL.

The Rate Training Manual and the Nonresident Career Course (RTM/NRCC) was prepared to assist the fireman apprentice to qualify and to advance to fireman in the Navy. The manual is designed for individual study and provides subject matter that relates directly to the occupational qualifications of the fireman rating. Fireman is one of the lower…

From Poster Presentation to Publication: National Congress of Child and Adolescent Psychiatry.

PubMed

Mutlu, Caner; Kaya Mutlu, Ebru; Kiliçoğlu, Ali Güven; Yorbik, Özgür

2015-06-01

The aims of this study were as follows: 1) to determine publication rate, time to publication, and study design of poster presentations accepted at the National Congress of Child and Adolescent Psychiatry (NCCAP) and converted to publication and the degree of first author in a published article and journal index and 2) to investigate the relationship of these data with each other. The poster presentations of four congresses organized between 2005 and 2008 were investigated separately. The presentations were screened by taking into account the title and the first and second author in English and Turkish languages via PubMed and Google Academic databases. Published studies, time between presentation and publishing date, study design, degree of first author, and journal index of these studies were recorded. Fifty-four (25.2%) of 214 poster presentations were published in international and national peer-reviewed journals. Of the published articles, 74.1% (n=40) were research type and 61.1% (n=33) were found in the Science Citation Index (SCI) and Science Citation Index-Expanded (SCI-E) peer-reviewed journals. The first author in 42.6% (n=23) of published articles were assistant professors. The average time between presentation and publishing date was 30.72±18.89 months. Statistical differences were not determined between publication rate and study design; between time to publication and study type/study design, degree of first author, and journal index; and between journal index and study design and degree of first author (p>0.05). It was found that research articles were published significantly more by teaching staff than experts and other researchers (p<0.05). Compared with literature data, it was found that the time to publication was longer while the publication rate was similar for poster presentations in our congresses. Based on these results, it is important to create necessary conditions and encourage the researchers to publish the poster presentations presented in NCCAP.

From Poster Presentation to Publication: National Congress of Child and Adolescent Psychiatry

PubMed Central

MUTLU, Caner; KAYA MUTLU, Ebru; KILIÇOĞLU, Ali Güven; YORBIK, Özgür

2015-01-01

Introduction The aims of this study were as follows: 1) to determine publication rate, time to publication, and study design of poster presentations accepted at the National Congress of Child and Adolescent Psychiatry (NCCAP) and converted to publication and the degree of first author in a published article and journal index and 2) to investigate the relationship of these data with each other. Methods The poster presentations of four congresses organized between 2005 and 2008 were investigated separately. The presentations were screened by taking into account the title and the first and second author in English and Turkish languages via PubMed and Google Academic databases. Published studies, time between presentation and publishing date, study design, degree of first author, and journal index of these studies were recorded. Results Fifty-four (25.2%) of 214 poster presentations were published in international and national peer-reviewed journals. Of the published articles, 74.1% (n=40) were research type and 61.1% (n=33) were found in the Science Citation Index (SCI) and Science Citation Index-Expanded (SCI-E) peer-reviewed journals. The first author in 42.6% (n=23) of published articles were assistant professors. The average time between presentation and publishing date was 30.72±18.89 months. Statistical differences were not determined between publication rate and study design; between time to publication and study type/study design, degree of first author, and journal index; and between journal index and study design and degree of first author (p>0.05). It was found that research articles were published significantly more by teaching staff than experts and other researchers (p<0.05). Conclusion Compared with literature data, it was found that the time to publication was longer while the publication rate was similar for poster presentations in our congresses. Based on these results, it is important to create necessary conditions and encourage the researchers to publish the poster presentations presented in NCCAP. PMID:28360689

Design of a lamella settler for biomass recycling in continuous ethanol fermentation process.

PubMed

Tabera, J; Iznaola, M A

1989-04-20

The design and application of a settler to a continuous fermentation process with yeast recycle were studied. The compact lamella-type settler was chosen to avoid large volumes associated with conventional settling tanks. A rationale of the design method is covered. The sedimentation area was determined by classical batch settling rate tests and sedimentation capacity calculation. Limitations on the residence time of the microorganisms in the settler, rather than sludge thickening considerations, was the approach employed for volume calculation. Fermentation rate tests with yeast after different sedimentation periods were carried out to define a suitable residence time. Continuous cell recycle fermentation runs, performed with the old and new sedimentation devices, show that lamella settler improves biomass recycling efficiency, being the process able to operate at higher sugar concentrations and faster dilution rates.

Lunar surface vehicle model competition

NASA Technical Reports Server (NTRS)

1990-01-01

During Fall and Winter quarters, Georgia Tech's School of Mechanical Engineering students designed machines and devices related to Lunar Base construction tasks. These include joint projects with Textile Engineering students. Topics studied included lunar environment simulator via drop tower technology, lunar rated fasteners, lunar habitat shelter, design of a lunar surface trenching machine, lunar support system, lunar worksite illumination (daytime), lunar regolith bagging system, sunlight diffusing tent for lunar worksite, service apparatus for lunar launch vehicles, lunar communication/power cables and teleoperated deployment machine, lunar regolith bag collection and emplacement device, soil stabilization mat for lunar launch/landing site, lunar rated fastening systems for robotic implementation, lunar surface cable/conduit and automated deployment system, lunar regolith bagging system, and lunar rated fasteners and fastening systems. A special topics team of five Spring quarter students designed and constructed a remotely controlled crane implement for the SKITTER model.

Past and Present ARDS Mortality Rates: A Systematic Review.

PubMed

Máca, Jan; Jor, Ondřej; Holub, Michal; Sklienka, Peter; Burša, Filip; Burda, Michal; Janout, Vladimír; Ševčík, Pavel

2017-01-01

ARDS is severe form of respiratory failure with significant impact on the morbidity and mortality of critical care patients. Epidemiological data are crucial for evaluating the efficacy of therapeutic interventions, designing studies, and optimizing resource distribution. The goal of this review is to present general aspects of mortality data published over the past decades. A systematic search of the MEDLINE/PubMed was performed. The articles were divided according to their methodology, type of reported mortality, and time. The main outcome was mortality. Extracted data included study duration, number of patients, and number of centers. The mortality trends and current mortality were calculated for subgroups consisting of in-hospital, ICU, 28/30-d, and 60-d mortality over 3 time periods (A, before 1995; B, 1995-2000; C, after 2000). The retrospectivity and prospectivity were also taken into account. Moreover, we present the most recent mortality rates since 2010. One hundred seventy-seven articles were included in the final analysis. General mortality rates ranged from 11 to 87% in studies including subjects with ARDS of all etiologies (mixed group). Linear regression revealed that the study design (28/30-d or 60-d) significantly influenced the mortality rate. Reported mortality rates were higher in prospective studies, such as randomized controlled trials and prospective observational studies compared with retrospective observational studies. Mortality rates exhibited a linear decrease in relation to time period (P < .001). The number of centers showed a significant negative correlation with mortality rates. The prospective observational studies did not have consistently higher mortality rates compared with randomized controlled trials. The mortality trends over 3 time periods (before 1995, 1995-2000, and after 2000) yielded variable results in general ARDS populations. However, a mortality decrease was present mostly in prospective studies. Since 2010, the overall rates of in-hospital, ICU, and 28/30-d and 60-d mortality were 45, 38, 30, and 32%, respectively. Copyright © 2017 by Daedalus Enterprises.

Space shuttle OMS helium regulator design and development

NASA Technical Reports Server (NTRS)

Wichmann, H.; Kelly, T. L.; Lynch, R.

1974-01-01

Analysis, design, fabrication and design verification testing was conducted on the technological feasiblity of the helium pressurization regulator for the space shuttle orbital maneuvering system application. A prototype regulator was fabricated which was a single-stage design featuring the most reliable and lowest cost concept. A tradeoff study on regulator concepts indicated that a single-stage regulator with a lever arm between the valve and the actuator section would offer significant weight savings. Damping concepts were tested to determine the amount of damping required to restrict actuator travel during vibration. Component design parameters such as spring rates, effective area, contamination cutting, and damping were determined by test prior to regulator final assembly. The unit was subjected to performance testing at widely ranging flow rates, temperatures, inlet pressures, and random vibration levels. A test plan for propellant compatibility and extended life tests is included.

Study on the thermodynamical and mechanical conditions for the generation of high operating pressures with liquefied gases for low and very low flow rates

NASA Astrophysics Data System (ADS)

Nieratschker, Willi

1989-12-01

An investigation of the thermodynamical and mechanical conditions for extending the flow rate range in the direction of low flow rates with regard to the delivery of liquefied gases at high operating pressures is presented. For low flow rates, the especially critical cavitation problem connected with the pumping of liquefied gases becomes more acute, since with decreasing volume the ratio of heat losses to the hydraulic power becomes ever more unfavorable. A first prototype is designed, produced and investigated to evaluate design-related heat loss and piston seal problems. An approach to the solution is indicated for both problem areas with the application of a new and patented pump principle, and through investigation of a second prototype modified in several respects. By reducing the pump mass when designing the second pump prototype, the nonstationary cooling phase is greatly shortened, so that intermittent pump operation becomes possible when the pump is housed external to the storage tank.

Residualization Rates of Near Infrared Dyes for the Rational Design of Molecular Imaging Agents

PubMed Central

Cilliers, Cornelius; Liao, Jianshan; Atangcho, Lydia; Thurber, Greg M.

2016-01-01

Purpose Near infrared (NIR) fluorescence imaging is widely used for tracking antibodies and biomolecules in vivo. Clinical and preclinical applications include intraoperative imaging, tracking therapeutics, and fluorescent labeling as a surrogate for subsequent radiolabeling. Despite their extensive use, one of the fundamental properties of NIR dyes, the residualization rate within cells following internalization, has not been systematically studied. This rate is required for the rational design of probes and proper interpretation of in vivo results. Procedures In this brief report, we measure the cellular residualization rate of eight commonly used dyes encompassing three core structures (cyanine, BODIPY, and oxazine/thiazine/carbopyronin). Results We identify residualizing (half-life > 24 hrs) and non-residualizing dyes (half-life < 24 hrs) in both the far red (~650-680 nm) and near infrared (~740-800 nm) regions. Conclusions This data will allow researchers to independently and rationally select the wavelength and residualizing nature of dyes for molecular imaging agent design. PMID:25869081

Residualization Rates of Near-Infrared Dyes for the Rational Design of Molecular Imaging Agents.

PubMed

Cilliers, Cornelius; Liao, Jianshan; Atangcho, Lydia; Thurber, Greg M

2015-12-01

Near-infrared (NIR) fluorescence imaging is widely used for tracking antibodies and biomolecules in vivo. Clinical and preclinical applications include intraoperative imaging, tracking therapeutics, and fluorescent labeling as a surrogate for subsequent radiolabeling. Despite their extensive use, one of the fundamental properties of NIR dyes, the residualization rate within cells following internalization, has not been systematically studied. This rate is required for the rational design of probes and proper interpretation of in vivo results. In this brief report, we measure the cellular residualization rate of eight commonly used dyes encompassing three core structures (cyanine, boron-dipyrromethene (BODIPY), and oxazine/thiazine/carbopyronin). We identify residualizing (half-life >24 h) and non-residualizing (half-life <24 h) dyes in both the far-red (~650-680 nm) and near-infrared (~740-800 nm) regions. This data will allow researchers to independently and rationally select the wavelength and residualizing nature of dyes for molecular imaging agent design.

Pitch control margin at high angle of attack - Quantitative requirements (flight test correlation with simulation predictions)

NASA Technical Reports Server (NTRS)

Lackey, J.; Hadfield, C.

1992-01-01

Recent mishaps and incidents on Class IV aircraft have shown a need for establishing quantitative longitudinal high angle of attack (AOA) pitch control margin design guidelines for future aircraft. NASA Langley Research Center has conducted a series of simulation tests to define these design guidelines. Flight test results have confirmed the simulation studies in that pilot rating of high AOA nose-down recoveries were based on the short-term response interval in the forms of pitch acceleration and rate.

Evaluation of three coding schemes designed for improved data communication

NASA Technical Reports Server (NTRS)

Snelsire, R. W.

1974-01-01

Three coding schemes designed for improved data communication are evaluated. Four block codes are evaluated relative to a quality function, which is a function of both the amount of data rejected and the error rate. The Viterbi maximum likelihood decoding algorithm as a decoding procedure is reviewed. This evaluation is obtained by simulating the system on a digital computer. Short constraint length rate 1/2 quick-look codes are studied, and their performance is compared to general nonsystematic codes.

Load research manual. Volume 2: Fundamentals of implementing load research procedures

NASA Astrophysics Data System (ADS)

1980-11-01

This manual will assist electric utilities and state regulatory authorities in investigating customer electricity demand as part of cost-of-service studies, rate design, marketing research, system design, load forecasting, rate reform analysis, and load management research. Load research procedures are described in detail. Research programs at three utilities are compared: Carolina Power and Light Company, Long Island Lighting Company, and Southern California Edison Company. A load research bibliography and glossaries of load research and statistical terms are also included.

Block 2 SRM conceptual design studies. Volume 1, Book 1: Conceptual design package

NASA Technical Reports Server (NTRS)

Smith, Brad; Williams, Neal; Miller, John; Ralston, Joe; Richardson, Jennifer; Moore, Walt; Doll, Dan; Maughan, Jeff; Hayes, Fred

1986-01-01

The conceptual design studies of a Block 2 Solid Rocket Motor (SRM) require the elimination of asbestos-filled insulation and was open to alternate designs, such as case changes, different propellants, modified burn rate - to improve reliability and performance. Limitations were placed on SRM changes such that the outside geometry should not impact the physical interfaces with other Space Shuttle elements and should have minimum changes to the aerodynamic and dynamic characteristics of the Space Shuttle vehicle. Previous Space Shuttle SRM experience was assessed and new design concepts combined to define a valid approach to assured flight success and economic operation of the STS. Trade studies, preliminary designs, analyses, plans, and cost estimates are documented.

The influence of kinematic conditions and design on the wear of patella-femoral replacements

PubMed Central

Maiti, Raman; Fisher, John; Rowley, Liam

2014-01-01

The success rate of patella-femoral arthroplasty varies between 44% and 90% in 17 years of follow-up. Several studies have been performed previously for assessing the surface wear in the patella-femoral joint. However, they have not included all six degrees of freedom. The aim of this study was to develop a six-axis patella-femoral joint simulator to assess the wear rate for two patellae designs (round and oval dome) at different kinematic conditions. An increase in patellar rotation from 1° to 4° led to a significantly (p<0.049) increased wear rate of round dome from 8.6 mm3/million cycles to 12.3 mm3/million cycles. The wear rate for oval dome increased from 6.3 mm3/million cycles to 14.5 mm3/million cycles. However, the increase was nonsignificant (p>0.08). The increase in wear rate was likely due to the higher cross shear. A decrease in patellar medial lateral displacement from passive to constrained resulted in a nonsignificant reduction in wear (p>0.06). There was no significant difference in wear rate between the two patellae designs (p>0.28). The volumetric wear under all conditions was positively correlated with the level of passive patellar tilt (rho>0.8). This is the first report of preclinical wear simulation of patella-femoral joint in a six-axis simulator under different kinematic conditions. PMID:24477888

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…

Assessing the Generalizable Skills of Post-Secondary Vocational Students. A Validation Study.

ERIC Educational Resources Information Center

Greenan, James P.; Smith, Brandon B.

A study examined the feasibility, reliability, and validity of two instruments designed to assess the degree to which postsecondary vocational students possessed those generalizable skills that are believed to be functionally relevant to success in a vocational program. The instruments, a student self-rating and a teacher rating form, contained 81…

Sensory Over-Responsivity, Psychopathology, and Family Impairment in School-Aged Children

ERIC Educational Resources Information Center

Carter, Alice S.; Ben-Sasson, Ayelet; Briggs-Gowan, Margaret J.

2011-01-01

Objective: To establish the diagnostic validity of sensory overresponsivity (SOR), there is a need to document rates of SOR and the co-occurrence of SOR with other psychiatric disorders. Although this was not a diagnostic study of SOR, this study was designed to investigate rates of elevated SOR symptoms and associations between elevated SOR…

A Use Study of the Card Catalogs in the University of Illinois Music Library.

ERIC Educational Resources Information Center

Drone, Jeanette M.

1984-01-01

A multifaceted card catalog use study was conducted at University of Illinois Music Library to determine hourly rate of use at sound recording and book/music catalogs; time spent at catalogs; who uses catalogs and why; difficulties users encounter; success rate of users' searches; recommendations for designing online catalog. (16 references)…

Ecological Momentary Assessment Methodology in Chronic Pain Research: A Systematic Review.

PubMed

May, Marcella; Junghaenel, Doerte U; Ono, Masakatsu; Stone, Arthur A; Schneider, Stefan

2018-01-31

Self-reported pain intensity assessments are central to chronic pain research. Ecological momentary assessment (EMA) methodologies are uniquely positioned to collect these data, and are indeed being used in the field. However, EMA protocols are complex, and many decisions are necessary in the design of EMA research studies. A systematic literature review identified 105 articles drawing from 62 quantitative EMA research projects examining pain intensity in adult chronic pain patients. Study characteristics were tabulated to summarize and describe the use of EMA, with an emphasis placed on various dimensions of decision-making involved in executing EMA methodologies. Most identified studies considered within-person relationships between pain and other variables, and a few examined interventions on chronic pain. There was a trend toward the use of smartphones as EMA data collection devices more recently, and completion rates were not reported in nearly one third of studies. Pain intensity items varied widely with respect to number of scale points, anchor labels, and length of reporting period; most used numeric rating scales. Recommendations are provided for reporting to improve reproducibility, comparability, and interpretation of results, and for opportunities to clarify the importance of design decisions. Studies that use EMA methodologies to assess pain intensity are heterogeneous. Aspects of protocol design, including data input modality and pain item construction, have the potential to influence the data collected. Thorough reporting on design features and completion rates therefore facilitates reproducibility, comparability, and interpretation of study results. Copyright © 2018 The American Pain Society. Published by Elsevier Inc. All rights reserved.

Benefits and Barriers: Case Study of a Government Technology-Mediated Group Mentoring Program

ERIC Educational Resources Information Center

Harris, Brigitte; Cheng, Kwan Fan; Gorley, Charlotte

2015-01-01

Purpose: This study aims to describe the design of a provincial government ministry group mentoring program and examine mentees' and mentors' experiences in the program. Design/methodology/approach: A total of 151 mentees rated their satisfaction in a post-program survey. The survey was followed by in-depth, semi-structured interviews with 10…

Instructional design affects the efficacy of simulation-based training in central venous catheterization.

PubMed

Craft, Christopher; Feldon, David F; Brown, Eric A

2014-05-01

Simulation-based learning is a common educational tool in health care training and frequently involves instructional designs based on Experiential Learning Theory (ELT). However, little research explores the effectiveness and efficiency of different instructional design methodologies appropriate for simulations. The aim of this study was to compare 2 instructional design models, ELT and Guided Experiential Learning (GEL), to determine which is more effective for training the central venous catheterization procedure. Using a quasi-experimental randomized block design, nurse anesthetists completed training under 1 of the 2 instructional design models. Performance was assessed using a checklist of central venous catheterization performance, pass rates, and critical action errors. Participants in the GEL condition performed significantly better than those in the ELT condition on the overall checklist score after controlling for individual practice time (F[1, 29] = 4.021, P = .027, Cohen's d = .71), had higher pass rates (P = .006, Cohen's d = 1.15), and had lower rates of failure due to critical action errors (P = .038, Cohen's d = .81). The GEL model of instructional design is significantly more effective than ELT for simulation-based learning of the central venous catheterization procedure, yielding large differences in effect size. Copyright © 2014 Elsevier Inc. All rights reserved.

Investigation of relative risk estimates from studies of the same population with contrasting response rates and designs.

PubMed

Mealing, Nicole M; Banks, Emily; Jorm, Louisa R; Steel, David G; Clements, Mark S; Rogers, Kris D

2010-04-01

There is little empirical evidence regarding the generalisability of relative risk estimates from studies which have relatively low response rates or are of limited representativeness. The aim of this study was to investigate variation in exposure-outcome relationships in studies of the same population with different response rates and designs by comparing estimates from the 45 and Up Study, a population-based cohort study (self-administered postal questionnaire, response rate 18%), and the New South Wales Population Health Survey (PHS) (computer-assisted telephone interview, response rate ~60%). Logistic regression analysis of questionnaire data from 45 and Up Study participants (n = 101,812) and 2006/2007 PHS participants (n = 14,796) was used to calculate prevalence estimates and odds ratios (ORs) for comparable variables, adjusting for age, sex and remoteness. ORs were compared using Wald tests modelling each study separately, with and without sampling weights. Prevalence of some outcomes (smoking, private health insurance, diabetes, hypertension, asthma) varied between the two studies. For highly comparable questionnaire items, exposure-outcome relationship patterns were almost identical between the studies and ORs for eight of the ten relationships examined did not differ significantly. For questionnaire items that were only moderately comparable, the nature of the observed relationships did not differ materially between the two studies, although many ORs differed significantly. These findings show that for a broad range of risk factors, two studies of the same population with varying response rate, sampling frame and mode of questionnaire administration yielded consistent estimates of exposure-outcome relationships. However, ORs varied between the studies where they did not use identical questionnaire items.

Micro-Viscometer for Measuring Shear-Varying Blood Viscosity over a Wide-Ranging Shear Rate.

PubMed

Kim, Byung Jun; Lee, Seung Yeob; Jee, Solkeun; Atajanov, Arslan; Yang, Sung

2017-06-20

In this study, a micro-viscometer is developed for measuring shear-varying blood viscosity over a wide-ranging shear rate. The micro-viscometer consists of 10 microfluidic channel arrays, each of which has a different micro-channel width. The proposed design enables the retrieval of 10 different shear rates from a single flow rate, thereby enabling the measurement of shear-varying blood viscosity with a fixed flow rate condition. For this purpose, an optimal design that guarantees accurate viscosity measurement is selected from a parametric study. The functionality of the micro-viscometer is verified by both numerical and experimental studies. The proposed micro-viscometer shows 6.8% (numerical) and 5.3% (experimental) in relative error when compared to the result from a standard rotational viscometer. Moreover, a reliability test is performed by repeated measurement (N = 7), and the result shows 2.69 ± 2.19% for the mean relative error. Accurate viscosity measurements are performed on blood samples with variations in the hematocrit (35%, 45%, and 55%), which significantly influences blood viscosity. Since the blood viscosity correlated with various physical parameters of the blood, the micro-viscometer is anticipated to be a significant advancement for realization of blood on a chip.

Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

NASA Astrophysics Data System (ADS)

Polzin, Kurt A.; Godfroy, Thomas J.

2008-01-01

A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m3/hr.

Comparison of four different mobile devices for measuring heart rate and ECG with respect to aspects of usability and acceptance by older people.

PubMed

Ehmen, Hilko; Haesner, Marten; Steinke, Ines; Dorn, Mario; Gövercin, Mehmet; Steinhagen-Thiessen, Elisabeth

2012-05-01

In the area of product design and usability, most products are developed for the mass-market by technically oriented designers and developers for use by persons who themselves are also technically adept by today's standards. The demands of older people are commonly not given sufficient consideration within the early developmental process. In the present study, the usability and acceptability of four different devices meant to be worn for the measurement of heart rate or ECG were analyzed on the basis of qualitative subjective user ratings and structured interviews of twelve older participants. The data suggest that there was a relatively high acceptance concerning these belts by older adults but none of the four harnesses was completely usable. Especially problematic to the point of limiting satisfaction among older subjects were problems encountered while adjusting the length of the belt and/or closing the locking mechanism. The two devices intended for dedicated heart rate recording yielded the highest user ratings for design, and were clearly preferred for extended wearing time. Yet for all the devices participants identified several important deficiencies in their design, as well as suggestions for improvement. We conclude that the creation of an acceptable monitoring device for older persons requires designers and developers to consider the special demands and abilities of the target group. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Godfroy, Thomas J.

2008-01-01

A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

The design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator is presented. The intended applications of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37 to 43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

This paper presents the design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37-43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

This paper presents the design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37 to 43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

Using CFD Techniques to Predict Slosh Force Frequency and Damping Rate

NASA Technical Reports Server (NTRS)

Marsell, Brandon; Gangadharan, Sathya; Chatman, Yadira; Sudermann, James

2009-01-01

Resonant effects and energy dissipation due to sloshing fuel inside propellant tanks are problems that arise in the initial design of any spacecraft or launch vehicle. A faster and more reliable method for calculating these effects during the design stages is needed. Using Computational Fluid Dynamics (CFD) techniques, a model of these fuel tanks can be created and used to predict important parameters such as resonant slosh frequency and damping rate. This initial study addresses the case of free surface slosh. Future studies will focus on creating models for tanks fitted with propellant management devices (PMD) such as diaphragms and baffles.

Incidence and Outcomes of Cardiopulmonary Resuscitation in Pediatric Intensive Care Units

PubMed Central

Berg, Robert A.; Nadkarni, Vinay M.; Clark, Amy E.; Moler, Frank; Meert, Kathleen; Harrison, Rick E.; Newth, Christopher J. L.; Sutton, Robert M.; Wessel, David L.; Berger, John T.; Carcillo, Joseph; Dalton, Heidi; Heidemann, Sabrina; Shanley, Thomas P.; Zuppa, Athena F.; Doctor, Allan; Tamburro, Robert F.; Jenkins, Tammara L.; Dean, J. Michael; Holubkov, Richard; Pollack, Murray M.

2015-01-01

Objective To determine the incidence of cardiopulmonary resuscitation (CPR) in pediatric intensive care units (PICU) and subsequent outcomes. Design, Setting, and Patients Multi-center prospective observational study of children 30 minutes, p30 minutes of CPR. Conclusions These data establish that contemporary PICU CPR, including long durations of CPR, results in high rates of survival to hospital discharge (45%) and favorable neurologic outcomes among survivors (89%). Rates of survival with favorable neurologic outcomes were similar among cardiac and non-cardiac patients. The rigorous prospective, observational study design avoided the limitations of missing data and potential selection biases inherent in registry and administrative data. PMID:26646466

Configuration and design study of manipulator systems applicable to the free flying teleoperator. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Tewell, J. R.

1974-01-01

A preliminary design of a manipulator system, applicable to a free flying teleoperator spacecraft operating in conjunction with the shuttle or tug, is presented. A new control technique is proposed for application to the manipulator system. This technique, a range/azimuth/elevation rate-rate mode, was selected based upon the results of man-in-the-loop simulations. Several areas are identified in which additional emphasis must be placed prior to the development of the manipulator system. The study results in a manipulator system which will provide an effective method for servicing, maintaining, and repairing satellites to increase their useful life.

Predictors of Manuscript Publication: A Review of Obstetrics and Gynecology Society Meeting Abstracts.

PubMed

Muffly, Tyler M; Webster, Kelsey; Conageski, Christine; Guiahi, Maryam

2016-01-01

The authors attempted to understand the manuscript publication rate and predictors of publication of abstracts presented at obstetrical and gynecologic society meetings. In 2013, the authors obtained the text of all 2005 abstracts presented at a major generalist- and fellowship-associated society meetings. In this cross-sectional study, a search was completed for publication and identified possible predictors. The authors examined 1405 abstracts; the overall full-text publication rate was 54% (755/1405 publications) and the mean (SD) time to publication was 25.6 (20.8) months. Variables associated with publication in multivariable analysis included number of abstract authors (odds ratio [OR], 1.7; confidence interval [CI], 1.0-1.2), first authorship in American Congress of Obstetricians and Gynecologists district IV (OR, 1.7; CI, 0.9-3.1), prospective design (OR, 1.7; CI, 0.9-3.1), multicenter design (OR, 2.5; CI, 1.3-4.9), and oral presentation (OR, 3.2; CI, 1.4-7.3). Abstracts from specialty meetings were more likely to have these characteristics and, thus, higher publication rates. This study can guide project development for young researchers by informing them of key study design features associated with manuscript publication.

Systematic review of health literacy in Cochrane database studies on paediatric asthma educational interventions: searching beyond rigorous design.

PubMed

Zeni, Mary Beth

2012-03-01

The purpose of this study was to evaluate if paediatric asthma educational intervention studies included in the Cochrane Collaboration database incorporated concepts of health literacy. Inclusion criteria were established to identify review categories in the Cochrane Collaboration database specific to paediatric asthma educational interventions. Articles that met the inclusion criteria were selected from the Cochrane Collaboration database in 2010. The health literacy definition from Healthy People 2010 was used to develop a 4-point a priori rating scale to determine the extent a study reported aspects of health literacy in the development of an educational intervention for parents and/or children. Five Cochrane review categories met the inclusion criteria; 75 studies were rated for health literacy content regarding educational interventions with families and children living with asthma. A priori criteria were used for the rating process. While 52 (69%) studies had no information pertaining to health literacy, 23 (31%) reported an aspect of health literacy. Although all studies maintained the rigorous standards of randomized clinical trials, a model of health literacy was not reported regarding the design and implementation of interventions. While a more comprehensive health literacy model for the development of educational interventions with families and children may have been available after the reviewed studies were conducted, general literacy levels still could have been addressed. The findings indicate a need to incorporate health literacy in the design of client-centred educational interventions and in the selection criteria of relevant Cochrane reviews. Inclusion assures that health literacy is as important as randomization and statistical analyses in the research design of educational interventions and may even assure participation of people with literacy challenges. © 2012 The Author. International Journal of Evidence-Based Healthcare © 2012 The Joanna Briggs Institute.

Design study of wind turbines 50 kW to 3000 kW for electric utility applications: Analysis and design

NASA Technical Reports Server (NTRS)

1976-01-01

In the conceptual design task, several feasible wind generator systems (WGS) configurations were evaluated, and the concept offering the lowest energy cost potential and minimum technical risk for utility applications was selected. In the optimization task, the selected concept was optimized utilizing a parametric computer program prepared for this purpose. In the preliminary design task, the optimized selected concept was designed and analyzed in detail. The utility requirements evaluation task examined the economic, operational, and institutional factors affecting the WGS in a utility environment, and provided additional guidance for the preliminary design effort. Results of the conceptual design task indicated that a rotor operating at constant speed, driving an AC generator through a gear transmission is the most cost effective WGS configuration. The optimization task results led to the selection of a 500 kW rating for the low power WGS and a 1500 kW rating for the high power WGS.

The Danish National Health Survey 2010. Study design and respondent characteristics.

PubMed

Christensen, Anne Illemann; Ekholm, Ola; Glümer, Charlotte; Andreasen, Anne Helms; Hvidberg, Michael Falk; Kristensen, Peter Lund; Larsen, Finn Breinholt; Ortiz, Britta; Juel, Knud

2012-06-01

In 2010 the five Danish regions and the National Institute of Public Health at the University of Southern Denmark conducted a national representative health survey among the adult population in Denmark. This paper describes the study design and the sample and study population as well as the content of the questionnaire. The survey was based on five regional stratified random samples and one national random sample. The samples were mutually exclusive. A total of 298,550 individuals (16 years or older) were invited to participate. Information was collected using a mixed mode approach (paper and web questionnaires). A questionnaire with a minimum of 52 core questions was used in all six subsamples. Calibrated weights were computed in order to take account of the complex survey design and reduce non-response bias. In all, 177,639 individuals completed the questionnaire (59.5%). The response rate varied from 52.3% in the Capital Region of Denmark sample to 65.5% in the North Denmark Region sample. The response rate was particularly low among young men, unmarried people and among individuals with a different ethnic background than Danish. The survey was a result of extensive national cooperation across sectors, which makes it unique in its field of application, e.g. health surveillance, planning and prioritizing public health initiatives and research. However, the low response rate in some subgroups of the study population can pose problems in generalizing data, and efforts to increase the response rate will be important in the forthcoming surveys.

Analysis of flow field characteristics in IC equipment chamber based on orthogonal design

NASA Astrophysics Data System (ADS)

Liu, W. F.; Yang, Y. Y.; Wang, C. N.

2017-01-01

This paper aims to study the influence of the configuration of processing chamber as a part of IC equipment on flow field characteristics. Four parameters, including chamber height, chamber diameter, inlet mass flow rate and outlet area, are arranged using orthogonally design method to study their influence on flow distribution in the processing chamber with the commercial software-Fluent. The velocity, pressure and temperature distribution above the holder were analysed respectively. The velocity difference value of the gas flow above the holder is defined as the evaluation criteria to evaluate the uniformity of the gas flow. The quantitative relationship between key parameters and the uniformity of gas flow was found through analysis of experimental results. According to our study, the chamber height is the most significant factor, and then follows the outlet area, chamber diameter and inlet mass flow rate. This research can provide insights into the study and design of configuration of etcher, plasma enhanced chemical vapor deposition (PECVD) equipment, and other systems with similar configuration and processing condition.

Recovery Act: Energy Efficiency of Data Networks through Rate Adaptation (EEDNRA) - Final Technical Report

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

Matthew Andrews; Spyridon Antonakopoulos; Steve Fortune

2011-07-12

This Concept Definition Study focused on developing a scientific understanding of methods to reduce energy consumption in data networks using rate adaptation. Rate adaptation is a collection of techniques that reduce energy consumption when traffic is light, and only require full energy when traffic is at full provisioned capacity. Rate adaptation is a very promising technique for saving energy: modern data networks are typically operated at average rates well below capacity, but network equipment has not yet been designed to incorporate rate adaptation. The Study concerns packet-switching equipment, routers and switches; such equipment forms the backbone of the modern Internet.more » The focus of the study is on algorithms and protocols that can be implemented in software or firmware to exploit hardware power-control mechanisms. Hardware power-control mechanisms are widely used in the computer industry, and are beginning to be available for networking equipment as well. Network equipment has different performance requirements than computer equipment because of the very fast rate of packet arrival; hence novel power-control algorithms are required for networking. This study resulted in five published papers, one internal report, and two patent applications, documented below. The specific technical accomplishments are the following: • A model for the power consumption of switching equipment used in service-provider telecommunication networks as a function of operating state, and measured power-consumption values for typical current equipment. • An algorithm for use in a router that adapts packet processing rate and hence power consumption to traffic load while maintaining performance guarantees on delay and throughput. • An algorithm that performs network-wide traffic routing with the objective of minimizing energy consumption, assuming that routers have less-than-ideal rate adaptivity. • An estimate of the potential energy savings in service-provider networks using feasibly-implementable rate adaptivity. • A buffer-management algorithm that is designed to reduce the size of router buffers, and hence energy consumed. • A packet-scheduling algorithm designed to minimize packet-processing energy requirements. Additional research is recommended in at least two areas: further exploration of rate-adaptation in network switching equipment, including incorporation of rate-adaptation in actual hardware, allowing experimentation in operational networks; and development of control protocols that allow parts of networks to be shut down while minimizing disruption to traffic flow in the network. The research is an integral part of a large effort within Bell Laboratories, Alcatel-Lucent, aimed at dramatic improvements in the energy efficiency of telecommunication networks. This Study did not explicitly consider any commercialization opportunities.« less

Feasibility Study on Active Back Telemetry and Power Transmission Through an Inductive Link for Millimeter-Sized Biomedical Implants.

PubMed

Yeon, Pyungwoo; Mirbozorgi, S Abdollah; Lim, Jaemyung; Ghovanloo, Maysam

2017-12-01

This paper presents a feasibility study of wireless power and data transmission through an inductive link to a 1-mm 2 implant, to be used as a free-floating neural probe, distributed across a brain area of interest. The proposed structure utilizes a four-coil inductive link for back telemetry, shared with a three-coil link for wireless power transmission. We propose a design procedure for geometrical optimization of the inductive link in terms of power transmission efficiency (PTE) considering specific absorption rate and data rate. We have designed a low-power pulse-based active data transmission circuit and characterized performance of the proposed inductive link in terms of its data rate and bit error rate (BER). The 1-mm 2 data-Tx/power-Rx coil is implemented using insulated bonding wire with diameter, resulting in measured PTE in tissue media of 2.01% at 131 MHz and 1.8-cm coil separation distance when the resonator coil inner radius is 1 cm. The measured BER at 1-Mbps data rate was and in the air and tissue environments, respectively.

Implementation of quality by design approach in manufacturing process optimization of dry granulated, immediate release, coated tablets - a case study.

PubMed

Teżyk, Michał; Jakubowska, Emilia; Milanowski, Bartłomiej; Lulek, Janina

2017-10-01

The aim of this study was to optimize the process of tablets compression and identification of film-coating critical process parameters (CPPs) affecting critical quality attributes (CQAs) using quality by design (QbD) approach. Design of experiment (DOE) and regression methods were employed to investigate hardness, disintegration time, and thickness of uncoated tablets depending on slugging and tableting compression force (CPPs). Plackett-Burman experimental design was applied to identify critical coating process parameters among selected ones that is: drying and preheating time, atomization air pressure, spray rate, air volume, inlet air temperature, and drum pressure that may influence the hardness and disintegration time of coated tablets. As a result of the research, design space was established to facilitate an in-depth understanding of existing relationship between CPPs and CQAs of intermediate product (uncoated tablets). Screening revealed that spray rate and inlet air temperature are two most important factors that affect the hardness of coated tablets. Simultaneously, none of the tested coating factors have influence on disintegration time. The observation was confirmed by conducting film coating of pilot size batches.

Comparison of sampling methodologies and estimation of population parameters for a temporary fish ectoparasite.

PubMed

Artim, J M; Sikkel, P C

2016-08-01

Characterizing spatio-temporal variation in the density of organisms in a community is a crucial part of ecological study. However, doing so for small, motile, cryptic species presents multiple challenges, especially where multiple life history stages are involved. Gnathiid isopods are ecologically important marine ectoparasites, micropredators that live in substrate for most of their lives, emerging only once during each juvenile stage to feed on fish blood. Many gnathiid species are nocturnal and most have distinct substrate preferences. Studies of gnathiid use of habitat, exploitation of hosts, and population dynamics have used various trap designs to estimate rates of gnathiid emergence, study sensory ecology, and identify host susceptibility. In the studies reported here, we compare and contrast the performance of emergence, fish-baited and light trap designs, outline the key features of these traps, and determine some life cycle parameters derived from trap counts for the Eastern Caribbean coral-reef gnathiid, Gnathia marleyi. We also used counts from large emergence traps and light traps to estimate additional life cycle parameters, emergence rates, and total gnathiid density on substrate, and to calibrate the light trap design to provide estimates of rate of emergence and total gnathiid density in habitat not amenable to emergence trap deployment.

Medicare Part D Claims Rejections for Nursing Home Residents, 2006 to 2010

PubMed Central

Stevenson, David G.; Keohane, Laura M.; Mitchell, Susan L.; Zarowitz, Barbara J.; Huskamp, Haiden A.

2013-01-01

Objectives Much has been written about trends in Medicare Part D formulary design and consumers’ choice of plans, but little is known about the magnitude of claims rejections or their clinical and administrative implications. Our objective was to study the overall rate at which Part D claims are rejected, whether these rates differ across plans, drugs, and medication classes, and how these rejection rates and reasons have evolved over time. Study Design and Methods We performed descriptive analyses of data on paid and rejected Part D claims submitted by 1 large national long-term care pharmacy from 2006 to 2010. In each of the 5 study years, data included approximately 450,000 Medicare beneficiaries living in long-term care settings with approximately 4 million Part D drug claims. Claims rejection rates and reasons for rejection are tabulated for each study year at the plan, drug, and class levels. Results Nearly 1 in 6 drug claims was rejected during the first 5 years of the Medicare Part D program, and this rate has increased over time. Rejection rates and reasons for rejection varied substantially across drug products and Part D plans. Moreover, the reasons for denials evolved over our study period. Coverage has become less of a factor in claims rejections than it was initially and other formulary tools such as drug utilization review, quantity-related coverage limits, and prior authorization are increasingly used to deny claims. Conclusions Examining claims rejection rates can provide important supplemental information to assess plans’ generosity of coverage and to identify potential areas of concern. PMID:23145808

Systematic review of incidence and complications of herpes zoster: towards a global perspective

PubMed Central

Kawai, Kosuke; Gebremeskel, Berhanu G; Acosta, Camilo J

2014-01-01

Objective The objective of this study was to characterise the incidence rates of herpes zoster (HZ), also known as shingles, and risk of complications across the world. Design We systematically reviewed studies examining the incidence rates of HZ, temporal trends of HZ, the risk of complications including postherpetic neuralgia (PHN) and HZ-associated hospitalisation and mortality rates in the general population. The literature search was conducted using PubMed, EMBASE and the WHO library up to December 2013. Results We included 130 studies conducted in 26 countries. The incidence rate of HZ ranged between 3 and 5/1000 person-years in North America, Europe and Asia-Pacific, based on studies using prospective surveillance, electronic medical record data or administrative data with medical record review. A temporal increase in the incidence of HZ was reported in the past several decades across seven countries, often occurring before the introduction of varicella vaccination programmes. The risk of developing PHN varied from 5% to more than 30%, depending on the type of study design, age distribution of study populations and definition. More than 30% of patients with PHN experienced persistent pain for more than 1 year. The risk of recurrence of HZ ranged from 1% to 6%, with long-term follow-up studies showing higher risk (5–6%). Hospitalisation rates ranged from 2 to 25/100 000 person-years, with higher rates among elderly populations. Conclusions HZ is a significant global health burden that is expected to increase as the population ages. Future research with rigorous methods is important. PMID:24916088

50 ways to trace your veteran: increasing response rates can be cheap and effective

PubMed Central

Fear, Nicola Townsend; Van Staden, Lauren; Iversen, Amy; Hall, John; Wessely, Simon

2010-01-01

Background while low response rates need not introduce bias into research, having a lower percentage of responders does increase the potential for this to occur. This is of particular concern given the decline that has been occurring in response rates since the 1950s. However, there are various methods that can be incorporated into the study design, which can assist in increasing levels of participation. Objective To outline the methods used by the King's Centre for Military Health Research (KCMHR) when conducting a recent telephone survey of serving and ex-Service military personnel. Design Using participants who had already taken part in a questionnaire-based study on the health effects of serving in the UK Armed Forces (n=10,272), a subsample was selected for an in-depth telephone interview-based follow-up study. The subsample consisted of 1,105 participants, selected on the basis of their mental health status. An adjusted response rate of 76% was achieved (n=821). Results Various methods of contact were used in this study to ensure an adequate response rate was achieved. Conclusions Simple research strategies increase response rates and are likely to reduce bias. Use of multiple simultaneous tracing methods and customisation of the approach to the target population increases rapport between participants, ensuring that those who take part feel valued as members of the study. In the current climate of decreasing participation in studies, research teams need to engage with their study population and devise innovative strategies to keep participants involved in the research being undertaken. PMID:22893795

Design and development of solid carbide step drill K34 for machining of CFRP and GFRP composite laminates

NASA Astrophysics Data System (ADS)

Rangaswamy, T.; Nagaraja, R.

2018-04-01

The Study focused on design and development of solid carbide step drill K34 to drill holes on composite materials such as Carbon Fiber Reinforced Plastic (CFRP) and Glass Fiber Reinforced Plastic (GFRP). The step drill K34 replaces step wise drilling of diameter 6.5mm and 9 mm holes that reduces the setup time, cutting speed, feed rate cost, delamination and increase the production rate. Several researchers have analyzed the effect of drilling process on various fiber reinforced plastic composites by carrying out using conventional tools and machinery. However, this process operation can lead to different kind of damages such as delamination, fiber pullout, and local cracks. To avoid the problems encountered at the time of drilling, suitable tool material and geometry is essential. This paper deals with the design and development of K34 Carbide step drill used to drill holes on CFRP and GFRP laminates. An Experimental study carried out to investigate the tool geometry, feed rate and cutting speed that avoids delamination and fiber breakage.

Detecting Parental Deception Using a Behavior Rating Scale during Assessment of Attention-Deficit/Hyperactivity Disorder: An Experimental Study

ERIC Educational Resources Information Center

Norfolk, Philip A.; Floyd, Randy G.

2016-01-01

It is often assumed that parents completing behavior rating scales during the assessment of attention-deficit/hyperactivity disorder (ADHD) can deliberately manipulate the outcomes of the assessment. To detect these actions, items designed to detect over-reporting or under-reporting of results are sometimes embedded in such rating scales. This…

Psychometric Properties of the Working Memory Rating Scale for Spanish-Speaking English Language Learners

ERIC Educational Resources Information Center

Guzman-Orth, Danielle; Grimm, Ryan; Gerber, Michael; Orosco, Michael; Swanson, H. Lee; Lussier, Cathy

2015-01-01

The Working Memory Rating Scale (WMRS) was designed as a behavioral rating tool to assist teachers in identifying students at risk of working memory difficulties. The instrument was originally normed on 417 monolingual English-speaking children from the United Kingdom. The purpose of this study was to test the reliability and validity of the WMRS…

Tradevman 1 & C. Naval Education and Training Command. Rate Training Manual and Nonresident Career Course. Revised.

ERIC Educational Resources Information Center

Naval Education and Training Command, Washington, DC.

Designed as a self-study text for enlisted personnel of the Navy and Naval Reserve, this rate training manual presents information that is directly related to the professional standards for advancement to Petty Officer Third Class and Petty Officer Second Class in the Tradevman (TD) rating. (Tradevmen install, repair, modify, and maintain…

Words That Fascinate the Listener: Predicting Affective Ratings of On-Line Lectures

ERIC Educational Resources Information Center

Weninger, Felix; Staudt, Pascal; Schuller, Björn

2013-01-01

In a large scale study on 843 transcripts of Technology, Entertainment and Design (TED) talks, the authors address the relation between word usage and categorical affective ratings of lectures by a large group of internet users. Users rated the lectures by assigning one or more predefined tags which relate to the affective state evoked in the…

Influence of gamma-ray skyshine on nuclear facilities design

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

Ohta, M.; Tsuji, M.; Kimura, Y.

1986-01-01

In safety analysis of nuclear facilities, skyshine dose rate at site boundary is one of the most important shielding design problems. For nuclear power stations in Japan, the skyshine dose rate at the site boundary has been specified not to exceed 5 mR/yr by the authorities, including total dose contribution from all structures on site, and this guide is commonly applied to other nuclear fuel cycle facilities. Therefore the design criterion dose of each structure on site is, considering plot planning, shielding condition, and so on, defined as a value <5 mR/yr. The purpose of this study is to investigatemore » how skyshine dose standards or other factors have an influence on the design of nuclear facilities, in a parametric survey of gamma-ray skyshine.« less

Numerical investigation and performance characteristic mapping of an Archimedean screw hydroturbine

NASA Astrophysics Data System (ADS)

Schleicher, W. Chris

Computational Fluid Dynamics (CFD) is a crucial tool in the design and analysis of hydraulic machinery, especially in the design of a micro hydro turbine. The micro hydro turbine in question is for a low head (less than 60 meters), low volumetric flow rate (0.005 m3/s to 0.5 m 3/s) application with rotation rates varying from 200 RPM to 1500 RPM. The design of the runner geometry is discussed, specifically a non-uniform Archimedean Spiral with an outer diameter of 6 inches and length of 19.5 inches. The transient simulation method, making use of a frame of reference change and a rotating mesh between time-steps, is explained as well as the corresponding boundary conditions. Both simulation methods are compared and are determined to produce similar results. The rotating frame of reference method was determined to be the most suitable method for the mapping of performance characteristic such as required head, torque, power, and efficiency. Results of simulations for a non-uniform Archimedean Spiral are then presented. First, a spectral and temporal convergence study is conducted to make sure that the results are independent of time-step and mesh selection. Performance characteristics of a non-uniform pitched blade turbine are determined for a wide range of volumetric flow rates and rotation rates. The maximum efficiency of the turbine is calculated around 72% for the design of the turbine blade considered in the present study.

Making electronic prescribing alerts more effective: scenario-based experimental study in junior doctors

PubMed Central

Shah, Priya; Wyatt, Jeremy C; Makubate, Boikanyo; Cross, Frank W

2011-01-01

Objective Expert authorities recommend clinical decision support systems to reduce prescribing error rates, yet large numbers of insignificant on-screen alerts presented in modal dialog boxes persistently interrupt clinicians, limiting the effectiveness of these systems. This study compared the impact of modal and non-modal electronic (e-) prescribing alerts on prescribing error rates, to help inform the design of clinical decision support systems. Design A randomized study of 24 junior doctors each performing 30 simulated prescribing tasks in random order with a prototype e-prescribing system. Using a within-participant design, doctors were randomized to be shown one of three types of e-prescribing alert (modal, non-modal, no alert) during each prescribing task. Measurements The main outcome measure was prescribing error rate. Structured interviews were performed to elicit participants' preferences for the prescribing alerts and their views on clinical decision support systems. Results Participants exposed to modal alerts were 11.6 times less likely to make a prescribing error than those not shown an alert (OR 11.56, 95% CI 6.00 to 22.26). Those shown a non-modal alert were 3.2 times less likely to make a prescribing error (OR 3.18, 95% CI 1.91 to 5.30) than those not shown an alert. The error rate with non-modal alerts was 3.6 times higher than with modal alerts (95% CI 1.88 to 7.04). Conclusions Both kinds of e-prescribing alerts significantly reduced prescribing error rates, but modal alerts were over three times more effective than non-modal alerts. This study provides new evidence about the relative effects of modal and non-modal alerts on prescribing outcomes. PMID:21836158

Accounting for Relatedness in Family Based Genetic Association Studies

PubMed Central

McArdle, P.F.; O’Connell, J.R.; Pollin, T.I.; Baumgarten, M.; Shuldiner, A.R.; Peyser, P.A.; Mitchell, B.D.

2007-01-01

Objective Assess the differences in point estimates, power and type 1 error rates when accounting for and ignoring family structure in genetic tests of association. Methods We compare by simulation the performance of analytic models using variance components to account for family structure and regression models that ignore relatedness for a range of possible family based study designs (i.e., sib pairs vs. large sibships vs. nuclear families vs. extended families). Results Our analyses indicate that effect size estimates and power are not significantly affected by ignoring family structure. Type 1 error rates increase when family structure is ignored, as density of family structures increases, and as trait heritability increases. For discrete traits with moderate levels of heritability and across many common sampling designs, type 1 error rates rise from a nominal 0.05 to 0.11. Conclusion Ignoring family structure may be useful in screening although it comes at a cost of a increased type 1 error rate, the magnitude of which depends on trait heritability and pedigree configuration. PMID:17570925

Self-esteem and self-efficacy as predictors of attrition in associate degree nursing students.

PubMed

Peterson-Graziose, Virginia; Bryer, Jennifer; Nikolaidou, Maria

2013-06-01

There is a serious and growing shortage of nurses in the United States, and the high rate of student attrition from nursing programs has further added to this problem. The challenge for schools of nursing is to recruit increased numbers of qualified candidates into their programs and to determine ways to decrease the rate of student attrition. The purpose of this study was to determine whether self-esteem, self-efficacy, and life stressors were significantly related to student attrition in first-semester associate degree nursing students. A descriptive correlational design and nonprobability convenience sample of first-semester associate degree nursing students was used. Data were gathered using the Rosenberg Self-Esteem Scale, the General Self-Efficacy Scale, and the Holmes and Rahe Social Readjustment Rating Scale. Findings indicated that self-esteem was significantly associated with student attrition. Results from this study provide the basis for targeted interventions designed to decrease student attrition rates in associate degree nursing programs. Copyright 2013, SLACK Incorporated.

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study, volume 2

NASA Technical Reports Server (NTRS)

1981-01-01

The engine requirements are emphasized and include: high specific impulse within a restricted installed length constraint, long life, multiple starts, different thrust levels, and man-rated reliability. The engine operating characteristics and the major component analytical design are summarized.

The use of a robust capture-recapture design in small mammal population studies: A field example with Microtus pennsylvanicus

USGS Publications Warehouse

Nichols, James D.; Pollock, Kenneth H.; Hines, James E.

1984-01-01

The robust design of Pollock (1982) was used to estimate parameters of a Maryland M. pennsylvanicus population. Closed model tests provided strong evidence of heterogeneity of capture probability, and model M eta (Otis et al., 1978) was selected as the most appropriate model for estimating population size. The Jolly-Seber model goodness-of-fit test indicated rejection of the model for this data set, and the M eta estimates of population size were all higher than the Jolly-Seber estimates. Both of these results are consistent with the evidence of heterogeneous capture probabilities. The authors thus used M eta estimates of population size, Jolly-Seber estimates of survival rate, and estimates of birth-immigration based on a combination of the population size and survival rate estimates. Advantages of the robust design estimates for certain inference procedures are discussed, and the design is recommended for future small mammal capture-recapture studies directed at estimation.

Effects of design parameters and puff topography on heating coil temperature and mainstream aerosols in electronic cigarettes

NASA Astrophysics Data System (ADS)

Zhao, Tongke; Shu, Shi; Guo, Qiuju; Zhu, Yifang

2016-06-01

Emissions from electronic cigarettes (ECs) may contribute to both indoor and outdoor air pollution and the number of users is increasing rapidly. ECs operate based on the evaporation of e-liquid by a high-temperature heating coil. Both puff topography and design parameters can affect this evaporation process. In this study, both mainstream aerosols and heating coil temperature were measured concurrently to study the effects of design parameters and puff topography. The heating coil temperatures and mainstream aerosols varied over a wide range across different brands and within same brand. The peak heating coil temperature and the count median diameter (CMD) of EC aerosols increased with a longer puff duration and a lower puff flow rate. The particle number concentration was positively associated with the puff duration and puff flow rate. These results provide a better understanding of how EC emissions are affected by design parameters and puff topography and emphasize the urgent need to better regulate EC products.

Evaluating the impact of an intervention to increase uptake of modern contraceptives among adolescent girls (15-19 years) in Nigeria, Ethiopia and Tanzania: the Adolescents 360 quasi-experimental study protocol.

PubMed

Atchison, Christina Joanne; Mulhern, Emma; Kapiga, Saidi; Nsanya, Mussa Kelvin; Crawford, Emily E; Mussa, Mohammed; Bottomley, Christian; Hargreaves, James R; Doyle, Aoife Margaret

2018-05-31

Nigeria, Ethiopia and Tanzania have some of the highest teenage pregnancy rates and lowest rates of modern contraceptive use among adolescents. The transdisciplinary Adolescents 360 (A360) initiative being rolled out across these three countries uses human-centred design to create context-specific multicomponent interventions with the aim of increasing voluntary modern contraceptive use among girls aged 15-19 years. The primary objective of the outcome evaluation is to assess the impact of A360 on the modern contraceptive prevalence rate (mCPR) among sexually active girls aged 15-19 years. A360 targets different subpopulations of adolescent girls in the three countries. In Northern Nigeria and Ethiopia, the study population is married girls aged 15-19 years. In Southern Nigeria, the study population is unmarried girls aged 15-19 years. In Tanzania, both married and unmarried girls aged 15-19 years will be included in the study. In all settings, we will use a prepopulation and postpopulation-based cross-sectional survey design. In Nigeria, the study design will also include a comparison group. A one-stage sampling design will be used in Nigeria and Ethiopia. A two-stage sampling design will be used in Tanzania. Questionnaires will be administered face-to-face by female interviewers aged between 18 and 26 years. Study outcomes will be assessed before the start of A360 implementation in late 2017 and approximately 24 months after implementation in late 2019. Findings of this study will be widely disseminated through workshops, conference presentations, reports, briefings, factsheets and academic publications. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Measuring hunger and satiety in primary school children. Validation of a new picture rating scale.

PubMed

Bennett, Carmel; Blissett, Jackie

2014-07-01

Measuring hunger and satiety in children is essential to many studies of childhood eating behaviour. Few validated measures currently exist that allow children to make accurate and reliable ratings of hunger/satiety. Three studies aimed to validate the use of a new categorical rating scale in the context of estimated and real eating episodes. Forty-seven 6- to 8-year-olds participated in Study 1, which used a between-participant design. Results indicated that the majority of children were able to make estimated hunger/satiety ratings for a story character using the scale. No significant differences in the ratings of hunger/satiety of children measured before and after lunch were observed and likely causes are discussed. To account for inter-individual differences in hunger/satiety perceptions Study 2 employed a within-participant design. Fifty-four 5- to 7-year-olds participated and made estimated hunger/satiety ratings for a story character and real hunger/satiety ratings before and after lunch. The results indicated that the majority of children were able to use the scale to make estimated and real hunger and satiety ratings. Children were found to be significantly hungrier before compared to after lunch. As it was not possible to establish the types and quantities of food children ate for lunch a third study was carried out in a controlled laboratory environment. Thirty-six 6- to 9-year-olds participated in Study 3 and made hunger/satiety ratings before and after ingesting an ad libitum snack of known composition and quantity. Results indicated that children felt hungrier before than after the snack and that pre-snack hunger/satiety, and changes in hunger/satiety, were associated with snack intake. Overall, the studies indicate that the scale has potential for use with primary school children. Implications of the findings are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

A comparison of response rates in the English Longitudinal Study of Ageing and the Health and Retirement Study

PubMed Central

Cheshire, Hayley; Ofstedal, Mary Beth; Scholes, Shaun; Schroeder, Mathis

2013-01-01

Survey response rates are an important measure of the quality of a survey; this is true for both longitudinal and cross-sectional surveys. However, the concept of a response rate in the context of a panel survey is more complex than is the case for a cross-sectional survey. There are typically many different response rates that can be calculated for a panel survey, each of which may be relevant for a specific purpose. The main objective of our paper is to document and compare response rates for two long-term panel studies of ageing, the English Longitudinal Study of Ageing (ELSA) and the Health and Retirement Study (HRS) in the United States. To guide our selection and calculation of response rates for the two studies, we use a framework that was developed by Peter Lynn (2005) and present several different types of longitudinal response rates for the two surveys. We discuss similarities and differences in the study designs and protocols and how some of the differences affect comparisons of response rates across the two studies. PMID:24432049

Prioritizing the mHealth Design Space: A Mixed-Methods Analysis of Smokers' Perspectives.

PubMed

Hartzler, Andrea Lisabeth; BlueSpruce, June; Catz, Sheryl L; McClure, Jennifer B

2016-08-05

Smoking remains the leading cause of preventable disease and death in the United States. Therefore, researchers are constantly exploring new ways to promote smoking cessation. Mobile health (mHealth) technologies could be effective cessation tools. Despite the availability of commercial quit-smoking apps, little research to date has examined smokers' preferred treatment intervention components (ie, design features). Honoring these preferences is important for designing programs that are appealing to smokers and may be more likely to be adopted and used. The aim of this study was to understand smokers' preferred design features of mHealth quit-smoking tools. We used a mixed-methods approach consisting of focus groups and written surveys to understand the design preferences of adult smokers who were interested in quitting smoking (N=40). Focus groups were stratified by age to allow differing perspectives to emerge between older (>40 years) and younger (<40 years) participants. Focus group discussion included a "blue-sky" brainstorming exercise followed by participant reactions to contrasting design options for communicating with smokers, providing social support, and incentivizing program use. Participants rated the importance of preselected design features on an exit survey. Qualitative analyses examined emergent discussion themes and quantitative analyses compared feature ratings to determine which were perceived as most important. Participants preferred a highly personalized and adaptive mHealth experience. Their ideal mHealth quit-smoking tool would allow personalized tracking of their progress, adaptively tailored feedback, and real-time peer support to help manage smoking cravings. Based on qualitative analysis of focus group discussion, participants preferred pull messages (ie, delivered upon request) over push messages (ie, sent automatically) and preferred interaction with other smokers through closed social networks. Preferences for entertaining games or other rewarding incentives to encourage program use differed by age group. Based on quantitative analysis of surveys, participants rated the importance of select design features significantly differently (P<.001). Design features rated as most important included personalized content, the ability to track one's progress, and features designed to help manage nicotine withdrawal and medication side effects. Design features rated least important were quit-smoking videos and posting on social media. Communicating with stop-smoking experts was rated more important than communicating with family and friends about quitting (P=.03). Perceived importance of various design features varied by age, experience with technology, and frequency of smoking. Future mHealth cessation aids should be designed with an understanding of smokers' needs and preferences for these tools. Doing so does not guarantee treatment effectiveness, but balancing user preferences with best-practice treatment considerations could enhance program adoption and improve treatment outcomes. Grounded in the perspectives of smokers, we identify several design considerations, which should be prioritized when designing future mHealth cessation tools and which warrant additional empirical validation.

Impact of Rate Design Alternatives on Residential Solar Customer Bills. Increased Fixed Charges, Minimum Bills and Demand-based Rates

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

Bird, Lori; Davidson, Carolyn; McLaren, Joyce

With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset,more » on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.« less

The National Center on Indigenous Hawaiian Behavioral Health Study of Prevalence of Psychiatric Disorders in Native Hawaiian Adolescents

ERIC Educational Resources Information Center

Andrade, Naleen N.; Hishinuma, Earl S.; McDermott, John F., Jr.; Johnson, Ronald C.; Goebert, Deborah A.; Makini, George K., Jr.; Nahulu, Linda B.; Yuen, Noelle Y. C.; McArdle, John J.; Bell, Cathy K.; Carlton, Barry S.; Miyamoto, Robin H.; Nishimura, Stephanie T.; Else, Iwalani R. N.; Guerrero, Anthony P. S.; Darmal, Arsalan; Yates, Alayne; Waldron, Jane A.

2006-01-01

Objectives: The prevalence rates of disorders among a community-based sample of Hawaiian youths were determined and compared to previously published epidemiological studies. Method: Using a two-phase design, 7,317 adolescents were surveyed (60% participation rate), from which 619 were selected in a modified random sample during the 1992-1993 to…

Measuring Cognitive Load during Simulation-Based Psychomotor Skills Training: Sensitivity of Secondary-Task Performance and Subjective Ratings

ERIC Educational Resources Information Center

Haji, Faizal A.; Khan, Rabia; Regehr, Glenn; Drake, James; de Ribaupierre, Sandrine; Dubrowski, Adam

2015-01-01

As interest in applying cognitive load theory (CLT) to the study and design of pedagogic and technological approaches in healthcare simulation grows, suitable measures of cognitive load (CL) are needed. Here, we report a two-phased study investigating the sensitivity of subjective ratings of mental effort (SRME) and secondary-task performance…

Sickness Absenteeism Rate in Iranian Schools during the 2009 Epidemic of Type a Influenza

ERIC Educational Resources Information Center

Pourabbasi, Ata; Shirvani, Mahbubeh Ebrahimnegad; Khashayar, Patricia

2012-01-01

Influenza pandemic was a global event in 2009 and intraschool transmission was its main spread method. The present study was designed to evaluate the absenteeism rate during the type A influenza epidemic. Four hundred and eight students from both a guidance school and high school in the Iranian capital were recruited in this retrospective study.…

Development of a Family Intervention for Native Hawaiian Women with Cancer: A Pilot Study

ERIC Educational Resources Information Center

Mokuau, Noreen; Braun, Kathryn L.; Wong, Linda K.; Higuchi, Paula; Gotay, Carolyn C.

2008-01-01

Native Hawaiian women have high cancer rates and low survival rates. As with other women, a major source of support for Native Hawaiian women is their families. This pilot study reports on the feasibility of providing and measuring a culturally appropriate intervention designed to help Native Hawaiian women and their families deal with cancer. The…

Developing a Practical Rating Rubric of Speaking Test for University Students of English in Parepare, Indonesia

ERIC Educational Resources Information Center

Latifa, Ammang; Rahman, Asfah; Hamra, Arifuddin; Jabu, Baso; Nur, Rafi'ah

2015-01-01

This study aims to develop a practical rating rubric of speaking ability in the classroom setting. This research study involves the English speaking lecturers at a number of higher education institutions in Parepare, Indonesia. The product is designed based on Research and Development (R&D) approach, which is adopted from Gall, Gall, and Borg…

The Effect of Varying Teacher Presentation Rates on Responding during Discrete Trial Training for Two Children with Autism

ERIC Educational Resources Information Center

Roxburgh, Carole A.; Carbone, Vincent J.

2013-01-01

Recent research has emphasized the importance of manipulating antecedent variables to reduce interfering behaviors when teaching persons with autism. Few studies have focused on the effects of the rate of teacher-presented instructional demands as an independent variable. In this study, an alternating treatment design was used to evaluate the…

Aviation Support Equipment Technician (ASE 3 & 2 and ASM 3 & 2). Volume 1, Basics. Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Grant, Jesse R.; And Others

This Rate Training Manual and Nonresident Career Course (RTM/NRCC) form a self-study package that will enable aviation support equipment personnel to help themselves fulfill the requirements for advancement. Designed for individual study and not formal classroom instruction, the RTM provides subject matter that relates directly to the occupational…

Design and evaluation of liposomal formulation of pilocarpine nitrate.

PubMed

Rathod, S; Deshpande, S G

2010-03-01

Prolonged release drug delivery system of pilocarpine nitrate was made by optimizing thin layer film hydration method. Egg phosphatidylcholine and cholesterol were used to make multilamellar vesicles. Effects of charges over the vesicles were studied by incorporating dicetylphosphate and stearylamine. Various factors, which may affect the size, shape, encapsulation efficiency and release rate, were studied. Liposomes in the size range 0.2 to 1 µm were obtained by optimizing the process. Encapsulation efficiency of neutral, positive and negatively charged liposomes were found to be 32.5, 35.4 and 34.2 percent, respectively. In vitro drug release rate was studied on specially designed model. Biological response in terms of reduction in intraocular pressure was observed on rabbit eyes. Pilocarpine nitrate liposomes were lyophilized and stability studies were conducted.

Selected Factors Related to Selective Service Rejection and Rejection Rate in Delaware (1967): A Study of the Characteristics of Young Men Failing to Meet Mental Qualifications for Military Service.

ERIC Educational Resources Information Center

Price, Jay R.

This study sought information about selective service rejection in Delaware, specifically rejectee characteristics, reasons for rejection, and the high rejection rate in Delaware. The basic design was a modified case study method in which a sample of individual records were examined. Differences between this sample and national samples were tested…

Study design and hierarchy of evidence for surgical decision making.

PubMed

Sprague, Sheila; McKay, Paula; Thoma, Achilleas

2008-04-01

This article provides a historical overview of the hierarchy of evidence for surgical decision making and discusses key study designs in the hierarchy of evidence. This encompasses meta-analyses, randomized controlled trials, and observational studies, including cohort and case-controlled studies, case series and case reports, and basic science studies. This article also reviews the principles and importance of evidence-based plastic surgery and describes several systems to rate the strength of the scientific evidence.

Characterization of Commercial Li-ion Cells in Pouch Format

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith

2014-01-01

The li-ion pouch design cells exhibit similar behavior under off-nominal conditions as those in metal cans that do not have the internal safety devices. Safety should be well characterized before batteries are designed. Some of the li-ion pouch cell designs studied in this program reacted most violently to overcharge conditions at the medium rates but were tolerant to overcharge at very low rates. Some pouch cell designs have higher tolerance to vacuum exposures than some others. A comparison of the pouch material itself does not show a correlation between this tolerance and the number of layers or composition of the pouch indicating that this is a property of the electrode stack design inside the pouch. Reduced pressure (8 to 10 psi) test environments show that the extent of capacity degradation under reduced pressure environments is much less than that observed under vacuum conditions. Lithium-ion Pouch format cells are not necessarily true polymer cells.

Computer-aided design and experimental investigation of a hydrodynamic device: the microwire electrode

PubMed

Fulian; Gooch; Fisher; Stevens; Compton

2000-08-01

The development and application of a new electrochemical device using a computer-aided design strategy is reported. This novel design is based on the flow of electrolyte solution past a microwire electrode situated centrally within a large duct. In the design stage, finite element simulations were employed to evaluate feasible working geometries and mass transport rates. The computer-optimized designs were then exploited to construct experimental devices. Steady-state voltammetric measurements were performed for a reversible one-electron-transfer reaction to establish the experimental relationship between electrolysis current and solution velocity. The experimental results are compared to those predicted numerically, and good agreement is found. The numerical studies are also used to establish an empirical relationship between the mass transport limited current and the volume flow rate, providing a simple and quantitative alternative for workers who would prefer to exploit this device without the need to develop the numerical aspects.

Child Sexual Abuse in America--A Call for School & Community Action. A Report of a National Study.

ERIC Educational Resources Information Center

Helge, Doris

The rate of sexual abuse of children and adults in our society is appalling, and growing rapidly. This study was designed to determine trends in child sexual abuse prevention and treatment services offered by school districts across America. The questionnaire was designed to allow comparisons of urban, rural, and suburban school district programs…

An Observational Study for Evaluating the Effects of Interpersonal Problem-Solving Skills Training on Behavioural Dimensions

ERIC Educational Resources Information Center

Anliak, Sakire; Sahin, Derya

2010-01-01

The present observational study was designed to evaluate the effectiveness of the I Can Problem Solve (ICPS) programme on behavioural change from aggression to pro-social behaviours by using the DECB rating scale. Non-participant observation method was used to collect data in pretest-training-posttest design. It was hypothesised that the ICPS…

Profiles in Retention Part 1: Design Characteristics of a Graduate Synchronous Online Program

ERIC Educational Resources Information Center

Aversa, Elizabeth; MacCall, Steven

2013-01-01

This paper is a case study of a Master of Library and Information Studies degree program online option that has been unusually successful in retaining and graduating students. Design characteristics of this program that has maintained a retention rate of over 90 percent over five years are described and mapped to the literature on distance…

A Comparison of the Results of Many-Facet Rasch Analyses Based on Crossed and Judge Pair Designs

ERIC Educational Resources Information Center

Ilhan, Mustafa

2016-01-01

The aim of this study was to compare the results of many-facet Rasch analyses based on crossed and judge pair designs. The study was conducted with 168 eighth grade students and five judges. The study data were collected using an achievement test with open-ended questions and a holistic rubric that was used to rate the responses. In the data…

Ventilation loss and pressurization in the NASA launch/entry suit: Potential for heat stress

NASA Technical Reports Server (NTRS)

Kaufman, Jonathan W.; Dejneka, Katherine Y.; Askew, Gregory K.

1989-01-01

The potential of the NASA Launch/Entry Suit (LES) for producing heat stress in a simulated Space Shuttle cabin environment was studied. The testing was designed to identify potential heat stress hazards if the LES were pressurized or if ventilation were lost. Conditions were designed to simulate an extreme pre-launch situation with chamber temperatures maintained at dry bulb temperature = 27.2 +/- 0.1 C, globe temperature = 27.3 +/- 0.1 C, and wet bulb temperature = 21.1 +/- 0.3 C. Two females and two males, 23 to 34 years of age, were employed in this study, with two subjects having exposures in all 3 conditions. Test durations in the ventilated (V) and unventilated (UV) conditions were designed for 480 minutes, which all subjects achieved. Pressurized runs (Pr) were designed for 45 minutes, which all subjects also achieved. While some significant differences related to experimental conditions were noted in rectal and mean skin temperatures, evaporation rates, sweat rates, and heart rate, these differences were not thought to be physiologically significant. The results indicate that the LES garment, in either the Pr or UV state, poses no danger of inducing unacceptable heat stress under the conditions expected within the Space Shuttle cabin during launch or reentry.

Poster — Thur Eve — 56: Design of Quality Assurance Methodology for VMAT system on Agility System equipped with CVDR

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

Thind, K; Tolakanahalli, R

2014-08-15

The aim of this study was to analyze the feasibility of designing comprehensive QA plans using iComCAT for Elekta machines equipped with Agility multileaf collimator and continuously variable dose rate. Test plans with varying MLC speed, gantry speed, and dose rate were created and delivered in a controlled manner. A strip test was designed with three 1 cm MLC positions and delivered using dynamic, StepNShoot and VMAT techniques. Plans were also designed to test error in MLC position with various gantry speeds and various MLC speeds. The delivery fluence was captured using the electronic portal-imaging device. Gantry speed was foundmore » to be within tolerance as per the Canadian standards. MLC positioning errors at higher MLC speed with gravity effects does add more than 2 mm discrepancy. More tests need to be performed to evaluate MLC performance using independent measurement systems. The treatment planning system with end-to-end testing necessary for commissioning was also investigated and found to have >95% passing rates within 3%/3mm gamma criteria. Future studies involve performing off-axis gantry starshot pattern and repeating the tests on three matched Elekta linear accelerators.« less

Optimal Design and Operation of Permanent Irrigation Systems

NASA Astrophysics Data System (ADS)

Oron, Gideon; Walker, Wynn R.

1981-01-01

Solid-set pressurized irrigation system design and operation are studied with optimization techniques to determine the minimum cost distribution system. The principle of the analysis is to divide the irrigation system into subunits in such a manner that the trade-offs among energy, piping, and equipment costs are selected at the minimum cost point. The optimization procedure involves a nonlinear, mixed integer approach capable of achieving a variety of optimal solutions leading to significant conclusions with regard to the design and operation of the system. Factors investigated include field geometry, the effect of the pressure head, consumptive use rates, a smaller flow rate in the pipe system, and outlet (sprinkler or emitter) discharge.

Design and Verification of a Digital Controller for a 2-Piece Hemispherical Resonator Gyroscope.

PubMed

Lee, Jungshin; Yun, Sung Wook; Rhim, Jaewook

2016-04-20

A Hemispherical Resonator Gyro (HRG) is the Coriolis Vibratory Gyro (CVG) that measures rotation angle or angular velocity using Coriolis force acting the vibrating mass. A HRG can be used as a rate gyro or integrating gyro without structural modification by simply changing the control scheme. In this paper, differential control algorithms are designed for a 2-piece HRG. To design a precision controller, the electromechanical modelling and signal processing must be pre-performed accurately. Therefore, the equations of motion for the HRG resonator with switched harmonic excitations are derived with the Duhamel Integral method. Electromechanical modeling of the resonator, electric module and charge amplifier is performed by considering the mode shape of a thin hemispherical shell. Further, signal processing and control algorithms are designed. The multi-flexing scheme of sensing, driving cycles and x, y-axis switching cycles is appropriate for high precision and low maneuverability systems. The differential control scheme is easily capable of rejecting the common mode errors of x, y-axis signals and changing the rate integrating mode on basis of these studies. In the rate gyro mode the controller is composed of Phase-Locked Loop (PLL), amplitude, quadrature and rate control loop. All controllers are designed on basis of a digital PI controller. The signal processing and control algorithms are verified through Matlab/Simulink simulations. Finally, a FPGA and DSP board with these algorithms is verified through experiments.

An internal pilot design for prospective cancer screening trials with unknown disease prevalence.

PubMed

Brinton, John T; Ringham, Brandy M; Glueck, Deborah H

2015-10-13

For studies that compare the diagnostic accuracy of two screening tests, the sample size depends on the prevalence of disease in the study population, and on the variance of the outcome. Both parameters may be unknown during the design stage, which makes finding an accurate sample size difficult. To solve this problem, we propose adapting an internal pilot design. In this adapted design, researchers will accrue some percentage of the planned sample size, then estimate both the disease prevalence and the variances of the screening tests. The updated estimates of the disease prevalence and variance are used to conduct a more accurate power and sample size calculation. We demonstrate that in large samples, the adapted internal pilot design produces no Type I inflation. For small samples (N less than 50), we introduce a novel adjustment of the critical value to control the Type I error rate. We apply the method to two proposed prospective cancer screening studies: 1) a small oral cancer screening study in individuals with Fanconi anemia and 2) a large oral cancer screening trial. Conducting an internal pilot study without adjusting the critical value can cause Type I error rate inflation in small samples, but not in large samples. An internal pilot approach usually achieves goal power and, for most studies with sample size greater than 50, requires no Type I error correction. Further, we have provided a flexible and accurate approach to bound Type I error below a goal level for studies with small sample size.

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

Parmesano, Hethie; Kury, Theodore J.

The price of CO{sub 2} emissions allowances affects the structure of the utility's costs, which has implications for rate design and load management programs. Depending on the design of the program to recover these costs, utility total revenue requirements - and the rate design utilized to recover these requirements - may be impacted. A new way to think about rate design may be required. (author)

A survey of stakeholder perspectives on exoskeleton technology.

PubMed

Wolff, Jamie; Parker, Claire; Borisoff, Jaimie; Mortenson, W Ben; Mattie, Johanne

2014-12-19

Exoskeleton technology has potential benefits for wheelchair users' health and mobility. However, there are practical barriers to their everyday use as a mobility device. To further understand potential exoskeleton use, and facilitate the development of new technologies, a study was undertaken to explore perspectives of wheelchair users and healthcare professionals on reasons for use of exoskeleton technology, and the importance of a variety of device characteristics. An online survey with quantitative and qualitative components was conducted with wheelchair users and healthcare professionals working directly with individuals with mobility impairments. Respondents rated whether they would use or recommend an exoskeleton for four potential reasons. Seventeen design features were rated and compared in terms of their importance. An exploratory factor analysis was conducted to categorize the 17 design features into meaningful groupings. Content analysis was used to identify themes for the open ended questions regarding reasons for use of an exoskeleton. 481 survey responses were analyzed, 354 from wheelchair users and 127 from healthcare professionals. The most highly rated reason for potential use or recommendation of an exoskeleton was health benefits. Of the design features, 4 had a median rating of very important: minimization of falls risk, comfort, putting on/taking off the device, and purchase cost. Factor analysis identified two main categories of design features: Functional Activities and Technology Characteristics. Qualitative findings indicated that health and physical benefits, use for activity and access reasons, and psychosocial benefits were important considerations in whether to use or recommend an exoskeleton. This study emphasizes the importance of developing future exoskeletons that are comfortable, affordable, minimize fall risk, and enable functional activities. Findings from this study can be utilized to inform the priorities for future development of this technology.

Transfer of management training from alternative perspectives.

PubMed

Taylor, Paul J; Russ-Eft, Darlene F; Taylor, Hazel

2009-01-01

One hundred seven management training evaluations were meta-analyzed to compare effect sizes for the transfer of managerial training derived from different rating sources (self, superior, peer, and subordinate) and broken down by both study- and training-related variables. For studies as a whole, and interpersonal management skills training studies in particular, transfer effects based on trainees' self-ratings, and to a lesser extent ratings from their superiors, were largest and most varied across studies. In contrast, transfer effects based on peer ratings, and particularly subordinate ratings, were substantially smaller and more homogeneous. This pattern was consistent across different sources of studies, features of evaluation design, and within a subset of 14 studies that each included all 4 rating sources. Across most rating sources, transfer of training was greatest for studies conducted in nonmilitary settings, when raters were likely to have known whether the manager being rated had attended training, when criteria were targeted to training content, when training content was derived from an analysis of tasks and skill requirements, and when training included opportunities for practice. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Test Results of a Ten Cell Bipolar Nickel-hydrogen Battery

NASA Technical Reports Server (NTRS)

Cataldo, R. L.

1984-01-01

A study was initiated to design and evaluate a new design concept for nickel-hydrogen cells. This concept involved constructing a battery in a bipolar stack with cells consisting of a one plate for each nickel and hydrogen electrode. Preliminary designs at the system level of this concept promised improvements in both volumetric and gravimetric energy densities, thermal management, life extension, costs, and peak power capability over more conventional designs. Test results were most encouraging. This preprototype battery, built with less than ideal components and hardware, exceeded expectations. A total of 2000 LEO cycles at 80 percent depth of discharge were accrued. A cycle life goal of 30,000 cycles appears achievable with minor design changes. These improvements include advanced technology nickel electrodes, insulated bipolar plates and specifically designed frames to minimize shunt currents. The discharge rate capability of this design exceeds 25C. At the 10C discharge rate, 80% of the battery capacity can be withdrawn in six minutes. This data shows that the bipolar design is well suited for those applications requiring high peak power pulses.

RATES OF REACTION AND PROCESS DESIGN DATA FOR THE HYDROCARB PROCESS

EPA Science Inventory

The report provides experimental and process design data in support of studies for developing the coprocessing of fossil fuels with biomass by the Hydrocarb process. The experimental work includes the hydropyrolysis of biomass and the thermal decomposition of methane in a 2.44 m ...

Experimental Design for a Macrofoam Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

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

Piepel, Gregory F.; Hutchison, Janine R.

2014-04-16

This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (plating/counting and polymerase chain reaction) will be used. Only one previous study has investigated false negative as a function of affecting test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completingmore » gaps in the available information on the performance of macrofoam swab sampling at low concentrations.« less

Test-re-test reliability and inter-rater reliability of a digital pelvic inclinometer in young, healthy males and females.

PubMed

Beardsley, Chris; Egerton, Tim; Skinner, Brendon

2016-01-01

Objective. The purpose of this study was to investigate the reliability of a digital pelvic inclinometer (DPI) for measuring sagittal plane pelvic tilt in 18 young, healthy males and females. Method. The inter-rater reliability and test-re-test reliabilities of the DPI for measuring pelvic tilt in standing on both the right and left sides of the pelvis were measured by two raters carrying out two rating sessions of the same subjects, three weeks apart. Results. For measuring pelvic tilt, inter-rater reliability was designated as good on both sides (ICC = 0.81-0.88), test-re-test reliability within a single rating session was designated as good on both sides (ICC = 0.88-0.95), and test-re-test reliability between two rating sessions was designated as moderate on the left side (ICC = 0.65) and good on the right side (ICC = 0.85). Conclusion. Inter-rater reliability and test-re-test reliability within a single rating session of the DPI in measuring pelvic tilt were both good, while test-re-test reliability between rating sessions was moderate-to-good. Caution is required regarding the interpretation of the test-re-test reliability within a single rating session, as the raters were not blinded. Further research is required to establish validity.

Sensitivity study of the monogroove with screen heat pipe design

NASA Technical Reports Server (NTRS)

Evans, Austin L.; Joyce, Martin

1988-01-01

The present sensitivity study of design variable effects on the performance of a monogroove-with-screen heat pipe obtains performance curves for maximum heat-transfer rates vs. operating temperatures by means of a computer code; performance projections for both 1-g and zero-g conditions are obtainable. The variables in question were liquid and vapor channel design, wall groove design, and the number of feed lines in the evaporator and condenser. The effect on performance of three different working fluids, namely ammonia, methanol, and water, were also determined. Greatest sensitivity was to changes in liquid and vapor channel diameters.

How can we improve stroke thrombolysis rates? A review of health system factors and approaches associated with thrombolysis administration rates in acute stroke care.

PubMed

Paul, Christine L; Ryan, Annika; Rose, Shiho; Attia, John R; Kerr, Erin; Koller, Claudia; Levi, Christopher R

2016-04-08

Thrombolysis using intravenous (IV) tissue plasminogen activator (tPA) is one of few evidence-based acute stroke treatments, yet achieving high rates of IV tPA delivery has been problematic. The 4.5-h treatment window, the complexity of determining eligibility criteria and the availability of expertise and required resources may impact on treatment rates, with barriers encountered at the levels of the individual clinician, the social context and the health system itself. The review aimed to describe health system factors associated with higher rates of IV tPA administration for ischemic stroke and to identify whether system-focussed interventions increased tPA rates for ischemic stroke. Published original English-language research from four electronic databases spanning 1997-2014 was examined. Observational studies of the association between health system factors and tPA rates were described separately from studies of system-focussed intervention strategies aiming to increase tPA rates. Where study outcomes were sufficiently similar, a pooled meta-analysis of outcomes was conducted. Forty-one articles met the inclusion criteria: 7 were methodologically rigorous interventions that met the Cochrane Collaboration Evidence for Practice and Organization of Care (EPOC) study design guidelines and 34 described observed associations between health system factors and rates of IV tPA. System-related factors generally associated with higher IV tPA rates were as follows: urban location, centralised or hub and spoke models, treatment by a neurologist/stroke nurse, in a neurology department/stroke unit or teaching hospital, being admitted by ambulance or mobile team and stroke-specific protocols. Results of the intervention studies suggest that telemedicine approaches did not consistently increase IV tPA rates. Quality improvement strategies appear able to provide modest increases in stroke thrombolysis (pooled odds ratio = 2.1, p = 0.05). In order to improve IV tPA rates in acute stroke care, specific health system factors need to be targeted. Multi-component quality improvement approaches can improve IV tPA rates for stroke, although more thoughtfully designed and well-reported trials are required to safely increase rates of IV tPA to eligible stroke patients.

International Conference on the Mechanical Technology of Inertial Devices, University of Newcastle-upon-Tyne, England, Apr. 7-9, 1987, Proceedings

NASA Astrophysics Data System (ADS)

Various papers on the mechanical technology of inertial devices are presented. The topics addressed include: development of a directional gyroscope for remotely piloted vehicles and similar applications; a two-degree-of-freedom gyroscope with frictionless inner and outer gimbal pickoffs; oscillogyro design, manufacture, and performance; development of miniature two-axis rate gyroscope; mechanical design aspects of the electrostatically suspended gyroscope; role of gas-lubricated bearings in current and future sensors; development of a new microporous retainer material for precision ball bearings; design study for a high-stability, large-centrifuge test bed; evaluation of a two-axis rate gyro; operating principles of a two-axis angular rate transducer; and nutation frequency analysis. Also considered are: triaxial laser gyro; mechanical design considerations for a ring laser gyro dither mechanism; environmental considerations in the design of fiberoptic gyroscopes; manufacturing aspects of some critical high-precision mechanical components of inertial devices; dynamics and control of a gyroscopic force measurement system; high precision and high performance motion systems; use of multiple acceleration references to obtain high precision centrifuge data at low cost; gyro testing and evaluation at the Communications Research Centre; review of the mechanical design and development of a high-performance accelerometer; and silicon microengineering for accelerometers.

Consumer perceptions of specific design characteristics for front-of-package nutrition labels.

PubMed

Acton, R B; Vanderlee, L; Roberto, C A; Hammond, D

2018-04-01

An increasing number of countries are developing front-of-package (FOP) labels; however, there is limited evidence examining the impact of specific design characteristics for these labels. The current study investigated consumer perceptions of several FOP label design characteristics, including potential differences among sociodemographic sub-groups. Two hundred and thirty-four participants aged 16 years or older completed nine label rating tasks on a laptop at a local shopping mall in Canada. The rating tasks asked participants to rate five primary design characteristics (border, background presence, background colour, 'caution' symbol and government attribution) on their noticeability, readability, believability and likelihood of changing their beverage choice. FOP labels with a border, solid background and contrasting colours increased noticeability. A solid background increased readability, while a contrasting background colour reduced it. Both a 'caution' symbol and a government attribution increased the believability of the labels and the perceived likelihood of influencing beverage choice. The effect of the design characteristics was generally similar across sociodemographic groups, with modest differences in five of the nine outcomes. Label design characteristics, such as the use of a border, colour and symbols can enhance the salience of FOP nutrition labels and may increase the likelihood that FOP labels are used by consumers.

Explicit argumentation instruction to facilitate conceptual understanding and argumentation skills

NASA Astrophysics Data System (ADS)

Seda Cetin, Pinar

2014-01-01

Background: Argumentation is accepted by many science educators as a major component of science education. Many studies have investigated students' conceptual understanding and their engagement in argumentative activities. However, studies conducted in the subject of chemistry are very rare. Purpose: The present study aimed to investigate the effects of argumentation-based chemistry lessons on pre-service science teachers' understanding of reaction rate concepts, their quality of argumentation, and their consideration of specific reaction rate concepts in constructing an argument. Moreover, students' perceptions of argumentation lessons were explored. Sample: There were 116 participants (21 male and 95 female), who were pre-service first-grade science teachers from a public university. The participants were recruited from the two intact classes of a General Chemistry II course, both of which were taught by the same instructor. Design and methods: In the present study, non-equivalent control group design was used as a part of quasi-experimental design. The experimental group was taught using explicit argumentation activities, and the control group was instructed using traditional instruction. The data were collected using a reaction rate concept test, a pre-service teachers' survey, and the participants' perceptions of the argumentation lessons questionnaire. For the data analysis, the Wilcoxon Signed Rank Test, the Mann-Whitney U-test and qualitative techniques were used. Results: The results of the study indicated that an argumentation-based intervention caused significantly better acquisition of scientific reaction rate-related concepts and positively impacted the structure and complexity of pre-service teachers' argumentation. Moreover, the majority of the participants reported positive feelings toward argumentation activities. Conclusions: As students are encouraged to state and support their view in the chemistry classroom when studying reaction rate, it was observed that their understanding increased in terms of both the context and the quality of the argumentation that they produced. In light of the findings, it is suggested that argumentation activities should be developed to promote students' science content knowledge and argumentation skills.

Evaluation of the impact of fetal fibronectin test implementation on hospital admissions for preterm labour in Ontario: a multiple baseline time-series design.

PubMed

Fell, D B; Sprague, A E; Grimshaw, J M; Yasseen, A S; Coyle, D; Dunn, S I; Perkins, S L; Peterson, W E; Johnson, M; Bunting, P S; Walker, M C

2014-03-01

To determine the impact of a health system-wide fetal fibronectin (fFN) testing programme on the rates of hospital admission for preterm labour (PTL). Multiple baseline time-series design. Canadian province of Ontario. A retrospective population-based cohort of antepartum and delivered obstetrical admissions in all Ontario hospitals between 1 April 2002 and 31 March 2010. International Classification of Diseases codes in a health system-wide hospital administrative database were used to identify the study population and define the outcome measure. An aggregate time series of monthly rates of hospital admissions for PTL was analysed using segmented regression models after aligning the fFN test implementation date for each institution. Rate of obstetrical hospital admission for PTL. Estimated rates of hospital admission for PTL following fFN implementation were lower than predicted had pre-implementation trends prevailed. The reduction in the rate was modest, but statistically significant, when estimated at 12 months following fFN implementation (-0.96 hospital admissions for PTL per 100 preterm births; 95% confidence interval [CI], -1.02 to -0.90, P = 0.04). The statistically significant reduction was sustained at 24 and 36 months following implementation. Using a robust quasi-experimental study design to overcome confounding as a result of underlying secular trends or concurrent interventions, we found evidence of a small but statistically significant reduction in the health system-level rate of hospital admissions for PTL following implementation of fFN testing in a large Canadian province. © 2013 Royal College of Obstetricians and Gynaecologists.

Study of solid rocket motors for a space shuttle booster. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1972-01-01

The design, development, production, and launch support analysis for determining the solid propellant rocket engine to be used with the space shuttle are discussed. Specific program objectives considered were: (1) definition of engine designs to satisfy the performance and configuration requirements of the various vehicle/booster concepts, (2) definition of requirements to produce booster stages at rates of 60, 40, 20, and 10 launches per year in a man-rated system, and (3) estimation of costs for the defined SRM booster stages.

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

Pierson, L.G.; Witzke, E.L.

This effort studied the integration of innovative methods of key management crypto synchronization, and key agility while scaling encryption speed. Viability of these methods for encryption of ATM cell payloads at the SONET OC- 192 data rate (10 Gb/s), and for operation at OC-48 rates (2.5 Gb/s) was shown. An SNL-Developed pipelined DES design was adapted for the encryption of ATM cells. A proof-of-principle prototype circuit board containing 11 Electronically Programmable Logic Devices (each holding the equivalent of 100,000 gates) was designed, built, and used to prototype a high speed encryptor.

Patients' preferences for selection of endpoints in cardiovascular clinical trials.

PubMed

Chow, Robert D; Wankhedkar, Kashmira P; Mete, Mihriye

2014-01-01

To reduce the duration and overall costs of cardiovascular trials, use of the combined endpoints in trial design has become commonplace. Though this methodology may serve the needs of investigators and trial sponsors, the preferences of patients or potential trial subjects in the trial design process has not been studied. To determine the preferences of patients in the design of cardiovascular trials. Participants were surveyed in a pilot study regarding preferences among various single endpoints commonly used in cardiovascular trials, preference for single vs. composite endpoints, and the likelihood of compliance with a heart medication if patients similar to them participated in the trial design process. One hundred adult English-speaking patients, 38% male, from a primary care ambulatory practice located in an urban setting. Among single endpoints, participants rated heart attack as significantly more important than death from other causes (4.53 vs. 3.69, p=0.004) on a scale of 1-6. Death from heart disease was rated as significantly more important than chest pain (4.73 vs. 2.47, p<0.001), angioplasty/PCI/CABG (4.73 vs. 2.43, p<0.001), and stroke (4.73 vs. 2.43, p<0.001). Participants also expressed a slight preference for combined endpoints over single endpoint (43% vs. 57%), incorporation of the opinions of the study patient population into the design of trials (48% vs. 41% for researchers), and a greater likelihood of medication compliance if patient preferences were considered during trial design (67% indicated a significant to major effect). Patients are able to make judgments and express preferences regarding trial design. They prefer that the opinions of the study population rather than the general population be incorporated into the design of the study. This novel approach to study design would not only incorporate patient preferences into medical decision making, but it also has the potential to improve compliance with cardiovascular medications.

The Gifted Rating Scales-School Form: An Analysis of the Standardization Sample Based on Age, Gender, Race, and Diagnostic Efficiency

ERIC Educational Resources Information Center

Pfeiffer, Steven I.; Jarosewich, Tania

2007-01-01

This study analyzes the standardization sample of a new teacher rating scale designed to assist in the identification of gifted students. The Gifted Rating Scales-School Form (GRS-S) is based on a multidimensional model of giftedness. Results indicate no age or race/ethnicity differences on any of the scales and small but significant differences…

The Impact of Silhouette Randomization on the Results of Figure Rating Scales

ERIC Educational Resources Information Center

Duncan, Michael J.; Dodd, Lorna J.; Al-Nakeeb, Yahya

2005-01-01

This study was designed to examine the impact of silhouette randomization on the responses to rating scales developed to rate the perceived current and ideal body shape, as well as body dissatisfaction. Seventy students (30 men and 40 women), ages 18 to 43 (M [plus or minus] SD = 22.1 [plus or minus] 5.7) years, completed the Stunkard, Sorensen,…

Heart Rate Reactivity during Contingency Learning in 5- to 10-Month-Old at-Risk and Non-Risk Babies

ERIC Educational Resources Information Center

Millar, W. S.; Weir, C. G.

2007-01-01

The study investigated the dynamic relation between contingency learning and heart rate with risk and non-risk babies 5- to 10-months-old. Four groups were compared in a two contingency treatments (contingent, yoked) x two risk status design. Concurrent heart rate was monitored during three phases of a contingency learning task (baseline,…

Heart Rate Profiles of Children with and without Autism Spectrum Disorder in Response to Physical Play: A Preliminary Investigation

ERIC Educational Resources Information Center

Breslin, Casey M.; Rudisill, Mary E.; Wadsworth, Danielle W.

2015-01-01

In this study, the heart rate response of children with and without autism spectrum disorder (ASD) exposed to outdoor free play sessions during preschool was examined. Participants (n = 7; four children with ASD and three children who show typical development) wore Actiheart heart rate monitors during 6 school days. Using a single-subject design,…

Assessing the Effectiveness of a Learning Community Course Design to Improve the Math Performance of First-Year Students

ERIC Educational Resources Information Center

Hansen, Michele J.; Meshulam, Susan; Parker, Brooke

2013-01-01

National attention is focused on the persistent high failure rates for students enrolled in math courses, and the search for strategies to change these outcomes is on. This study used a mixed-method research design to assess the effectiveness of a learning community course designed to improve the math performance levels of firstyear students.…

An RF amplifier for ICRF studies in the LAPD

NASA Astrophysics Data System (ADS)

Martin, M. J.; Pribyl, P.; Gekelman, W.; Lucky, Z.

2015-12-01

An RF amplifier system was designed and is under construction at the UCLA Basic Plasma Science Facility. The system is designed to output 200 kW peak RMS power at 1% duty cycle with a 1 Hz rep rate at frequencies of 2-6 MHz. This paper describes the RF amplifier system with preliminary benchmarks. Current design challenges and future work are discussed.

Heterogeneous photocatalytic oxidation of atmospheric trace contaminants

NASA Technical Reports Server (NTRS)

Ollis, David F.

1994-01-01

Research was conducted on: (1) design and construction of a continuous flow photoreactor to study oxidation of trace atmospheric contaminants; (2) kinetics of acetone oxidation including adsorption equilibrium, variation of oxidatiin rate with acetone concentration and water, and variation of rate and apparent quantum yield with light intensity, and (3) kinetics of butanol oxidation, including rate variations; and (4) kinetics of catalyst deactivation including deactivation rate, influence of dark conditions, and photocatalytic regeneration in alcohol-free air.

On Suggestibility and Placebo: A Follow-Up Study.

PubMed

Lifshitz, Michael; Sheiner, Eli O; Olson, Jay A; Thériault, Rémi; Raz, Amir

2017-04-01

Identifying what makes some people respond well to placebos remains a major challenge. Here, we attempt to replicate an earlier study in which we found a relationship between hypnotic suggestibility and subjective ratings of relaxation following the ingestion of a placebo sedative (Sheiner, Lifshitz, & Raz, 2016). To assess the reliability of this effect, we tested 34 participants using a similar design. Participants ingested a placebo capsule in one of two conditions: (1) relaxation, wherein we described the capsule as a herbal sedative, or (2) control, wherein we described the capsule as inert. To index placebo response, we collected measures of blood pressure and heart rate, as well as self-report ratings of relaxation and drowsiness. Despite using a similar experimental design as in our earlier study, we were unable to replicate the correlation between hypnotic suggestibility and placebo response. Furthermore, whereas in our former experiment we observed a change in subjective ratings of relaxation but no change in physiological measures, here we found that heart rate dropped in the relaxation condition while subjective ratings remained unchanged. Even within a consistent context of relaxation, therefore, our present results indicate that placebos may induce effects that are fickle, tenuous, and unreliable. Although we had low statistical power, our findings tentatively accord with the notion that placebo response likely involves a complex, multifaceted interaction between traits, expectancies, and contexts.

Preliminary Study on GF/Carbon/Epoxy Composite Permeability in Designing Close Compartment Processing

NASA Astrophysics Data System (ADS)

Ya’acob, A. M.; Razali, D. A.; Anwar, U. A.; Radhi, A. H.; Ishak, A. A.; Minhat, M.; Aris, K. D. Mohd; Johari, M. K.; Casey, T.

2018-05-01

This project involves discovering how the permeability effect inside a close compartment in processing. After the appropriate pressure range was found, the close compartment was designed by studying the relationship between pressure output and the flow rate. A variety of pressure ranges have been used in this test to determine the effective pressure range that can be applied to the manufacturing process. Based on the results, the suitable pressure ranges were found between 55 psi to 75 psi. These pressures have been chosen based on the area covered on the product surfaces and time taken to penetrate the proposed area. The relationship between pressure and flow rate have been found to be directly proportional until 75 psi only. In conclusion, 70 psi for the proposed design of close compartment mould is suitable to be used to fulfill the required area of 120 mm square within 90 seconds.

[Optimization of Polysaccharide Extraction from Spirodela polyrrhiza by Plackett-Burman Design Combined with Box-Behnken Response Surface Methodology].

PubMed

Jiang, Zheng; Wang, Hong; Wu, Qi-nan

2015-06-01

To optimize the processing of polysaccharide extraction from Spirodela polyrrhiza. Five factors related to extraction rate of polysaccharide were optimized by the Plackett-Burman design. Based on this study, three factors, including alcohol volume fraction, extraction temperature and ratio of material to liquid, were regarded as investigation factors by Box-Behnken response surface methodology. The effect order of three factors on the extraction rate of polysaccharide from Spirodela polyrrhiza were as follows: extraction temperature, alcohol volume fraction,ratio of material to liquid. According to Box-Behnken response, the best extraction conditions were: alcohol volume fraction of 81%, ratio of material to liquid of 1:42, extraction temperature of 100 degrees C, extraction time of 60 min for four times. Plackett-Burman design and Box-Behnken response surface methodology used to optimize the extraction process for the polysaccharide in this study is effective and stable.

Consistency of immigrant and country-of-birth suicide rates: a meta-analysis.

PubMed

Voracek, M; Loibl, L M

2008-10-01

Multifaceted evidence (family, twin, adoption, molecular genetic, geographic and surname studies of suicide) suggests genetic risk factors for suicide. Migrant studies are also informative in this context, but underused. In particular, a meta-analysis of the associations of immigrant (IMM) and country-of-birth (COB) suicide rates is unavailable. Thirty-three studies, reporting IMM suicide rates for nearly 50 nationalities in seven host countries (Australia, Austria, Canada, England, the Netherlands, Sweden and the USA), were retrieved. Total-population IMM and COB suicide rates were strongly positively associated (combined rank-order correlation across 20 eligible studies: 0.65, 95% CI: 0.56-0.73, P < 10(-9)). The effect generalized across both sexes, host countries and study periods. Following the logic of the migrant study design of genetic epidemiology, the correspondence of IMM and COB suicide rates is consistent with the assumption of population differences in the prevalence of genetic risk factors for suicide.

A scan statistic for identifying optimal risk windows in vaccine safety studies using self-controlled case series design.

PubMed

Xu, Stanley; Hambidge, Simon J; McClure, David L; Daley, Matthew F; Glanz, Jason M

2013-08-30

In the examination of the association between vaccines and rare adverse events after vaccination in postlicensure observational studies, it is challenging to define appropriate risk windows because prelicensure RCTs provide little insight on the timing of specific adverse events. Past vaccine safety studies have often used prespecified risk windows based on prior publications, biological understanding of the vaccine, and expert opinion. Recently, a data-driven approach was developed to identify appropriate risk windows for vaccine safety studies that use the self-controlled case series design. This approach employs both the maximum incidence rate ratio and the linear relation between the estimated incidence rate ratio and the inverse of average person time at risk, given a specified risk window. In this paper, we present a scan statistic that can identify appropriate risk windows in vaccine safety studies using the self-controlled case series design while taking into account the dependence of time intervals within an individual and while adjusting for time-varying covariates such as age and seasonality. This approach uses the maximum likelihood ratio test based on fixed-effects models, which has been used for analyzing data from self-controlled case series design in addition to conditional Poisson models. Copyright © 2013 John Wiley & Sons, Ltd.

Centre-Based Child Care Quality in Urban Australia

ERIC Educational Resources Information Center

Ishimine, Karin; Wilson, Rachel

2009-01-01

This study investigates the quality of childcare centres in urban Australian communities designated according to different bands of Centre Location Demographics (CLD). Childcare centres were assessed using the Early Childhood Environment Rating Scale- Revised Edition (ECERS-R) and the Early Childhood Environment Rating Scale-Extension (ECERS-E).…

Paperless Braille Reading: A Preliminary Research Report.

ERIC Educational Resources Information Center

Bourgeois, M.; Ashcroft, S. C.

The study involving three blind elementary school, six blind high school, and four blind college students was designed to establish oral reading rates and oral reading error rates for Ss reading conventional braille volumes and brailled materials with the Digi-cassette, an electronic braille reading and writing machine. Data suggested several…

Improving Principal Leadership through Feedback and Coaching

ERIC Educational Resources Information Center

Bickman, Leonard; Goldring, Ellen; De Andrade, Ana Regina; Breda, Carolyn; Goff, Peter

2012-01-01

The purpose of this study is to evaluate the efficacy of a feedback and coaching intervention designed to improve the quality of principal leadership. Principals received feedback from teachers on their instructional leadership, and their teachers' trust of them. Principals also provided self-ratings and they compared their teachers' ratings to…

Pre-Service and Beginning Teachers Rate the Utility of Virtual Museum Exhibits

ERIC Educational Resources Information Center

Iding, Marie; Nordbotten, Joan

2011-01-01

This study investigated criteria that 91 pre-service teachers used to evaluate award-winning virtual museum exhibits for future use in teaching. Individual differences affected ratings, including teaching experience, age and gender. A categorization of participants' reasons for selection included audience level, site design and information…

Factors Most Likely to Contribute to Positive Course Evaluations

ERIC Educational Resources Information Center

VanMaaren, Victoria G.; Jaquett, Caroline M.; Williams, Robert L.

2016-01-01

The purpose of this study was to determine the extent to which students differentially rated ten factors likely to affect their ratings on overall course evaluations. Students (N = 148) in several sections of an undergraduate educational psychology course indicated their preferences among several designated factors. We found remarkable similarity…

Physical Activity Based Professional Development for Teachers: The Importance of Whole School Involvement

ERIC Educational Resources Information Center

Till, Jude; Ferkins, Lesley; Handcock, Phil

2011-01-01

Objective: This study sought to investigate teachers' perceptions of a physical activity-related professional development intervention. Design: Interview-based qualitative approach founded on the interpretive paradigm. Setting: Purposive selection of one high-rated independent, and one low-rated public primary school from Auckland, New Zealand.…

How-to-Do-It: Apparatus & Experimental Design for Measuring Fermentation Rates in Yeast.

ERIC Educational Resources Information Center

Tatina, Robert

1989-01-01

Describes an apparatus that facilitates the quantitative study of fermentation in yeast by allowing simultaneous measurements of fermentation rates in several treatments and a control. Explains a laboratory procedure in which the apparatus is used. Several suggestions for further investigations are included. (Author/RT)

Preliminary Validation of the Motor Skills Rating Scale

ERIC Educational Resources Information Center

Cameron, Claire E.; Chen, Wei-Bing; Blodgett, Julia; Cottone, Elizabeth A.; Mashburn, Andrew J.; Brock, Laura L.; Grissmer, David

2012-01-01

This study examined psychometric properties of the Motor Skills Rating Scale (MSRS), a questionnaire designed for classroom teachers of children in early elementary school. Items were developed with the guidance of two occupational therapists, and factor structure was examined with an exploratory factor analysis (EFA). The resulting model showed…

SRB/SLEEC (Solid Rocket Booster/Shingle Lap Extendible Exit Cone) feasibility study, volume 2. Appendix A: Design study for a SLEEC actuation system

NASA Technical Reports Server (NTRS)

Thompson, D. S.

1986-01-01

The results are presented of a design feasibility study of a self-contained (powered) actuation system for a Shingle Lap Extendible Exit Cone (SLEEC) for Transportation System (STS). The evolution of the SLEEC actuation system design is reviewed, the final design concept is summarized, and the results of the detailed study of the final concept of the actuation system are treated. A conservative design using proven mechanical components was established as a major program priority. The final mechanical design has a very low development risk since the components, which consist of ballscrews, gearing, flexible shaft drives, and aircraft cables, have extensive aerospace applications and a history of proven reliability. The mathematical model studies have shown that little or no power is required to deploy the SLEEC actuation system because acceleration forces and internal pressure from the rocket plume provide the required energies. A speed control brake is incorporated in the design in order to control the rate of deployment.

Reducing patients' falls rate in an Academic Medical Center (AMC) using Six Sigma "DMAIC" approach.

PubMed

Kuwaiti, Ahmed Al; Subbarayalu, Arun Vijay

2017-05-08

Purpose The purpose of this paper is to evaluate the impact of adopting the Six Sigma define, measure, analyze, improve and control (DMAIC) approach in reducing patients fall rate in an Academic Medical Center, Saudi Arabia. Design/methodology/approach A prospective study design was adopted and this study was conducted at King Fahd Hospital of the University (KFHU) during the year 2014. Based on the historical data of the patients' falls reported at KFHU during the year 2013, the goal was fixed to reduce the falls rate from 7.18 to<3 (over 60 percent reduction) by the end of December 2014. This study was conducted through the five phases of "DMAIC" approach using various quality tools. Three time periods were identified, namely, pre-intervention phase; intervention phase; and post-intervention phase. Appropriate strategies were identified through the process of brainstorming and were implemented to study the potential causes leading to the occurrence of falls. Findings The pre-intervention falls rate was reported as 6.57 whereas the post-intervention falls rate was measured as 1.91 (demonstrating a 70.93 percent reduction) after the implementation of improvement strategies. The adherence rate toward the practice of carrying falls risk assessment and hourly rounding was observed to be high where 88 percent of nurses are regularly practicing it. A control plan was also executed to sustain the improvements obtained. Originality/value The Six Sigma "DMAIC" approach improves the processes related to the prevention of falls. A greater reduction in patients falls rate (over 70 percent) was observed after the implementation of the improvement strategy.

The role and benefits of accessing primary care patient records during unscheduled care: a systematic review.

PubMed

Bowden, Tom; Coiera, Enrico

2017-09-22

The purpose of this study was to assess the impact of accessing primary care records on unscheduled care. Unscheduled care is typically delivered in hospital Emergency Departments. Studies published to December 2014 reporting on primary care record access during unscheduled care were retrieved. Twenty-two articles met inclusion criteria from a pool of 192. Many shared electronic health records (SEHRs) were large in scale, servicing many millions of patients. Reported utilization rates by clinicians was variable, with rates >20% amongst health management organizations but much lower in nation-scale systems. No study reported on clinical outcomes or patient safety, and no economic studies of SEHR access during unscheduled care were available. Design factors that may affect utilization included consent and access models, SEHR content, and system usability and reliability. Despite their size and expense, SEHRs designed to support unscheduled care have been poorly evaluated, and it is not possible to draw conclusions about any likely benefits associated with their use. Heterogeneity across the systems and the populations they serve make generalization about system design or performance difficult. None of the reviewed studies used a theoretical model to guide evaluation. Value of Information models may be a useful theoretical approach to design evaluation metrics, facilitating comparison across systems in future studies. Well-designed SEHRs should in principle be capable of improving the efficiency, quality and safety of unscheduled care, but at present the evidence for such benefits is weak, largely because it has not been sought.

Factors of Resilience That Support University Art and Design Students

ERIC Educational Resources Information Center

Morgan, Ruth C.

2016-01-01

Graduation rates in bachelor's degrees in the United States continue to be lower than stakeholders expect, despite the many advantages of college completion. This phenomenological study investigated the interplay between resilience, coping strategies, and college completion for undergraduate art and design students in an effort to improve…

Chairside Computer-Aided Design/Computer-Aided Manufacture All-Ceramic Crown and Endocrown Restorations: A 7-Year Survival Rate Study.

PubMed

Fages, Michel; Raynal, Jacques; Tramini, Paul; Cuisinier, Frédéric Jg; Durand, Jean-Cédric

The objective of the present study was to analyze the clinical outcomes of 447 monoblock ceramic chairside computer-aided design/computer-aided manufacture (CAD/CAM) reconstructions over a 7-year functional period. Of these reconstructions, 212 were peripheral crowns and 235 were endocrowns. The restorations were placed between 2003 and 2008 in a total of 323 patients. They were created using a chairside CAD/CAM method and the same materials in all cases. All of the crowns were manufactured and glued during the same clinical session by the same practitioner. Data were descriptively analyzed and survival probabilities were calculated using Kaplan-Meier statistics. Of the 447 restorations, only 6 failures occurred, resulting in a success rate of 98.66%. All of the failures were the result of a partial ceramic fracture. Of the six ceramic fractures, five appeared on peripheral crowns and one on an endocrown. All fractures appeared in the first 24 months, including two in the first month. Log-rank test comparing incidence rates between crowns and endocrowns showed no significant differences (P = .08). This survival rate study reinforced the use of CAD/CAM full ceramic crowns and endocrowns on molars, showing a much more favorable survival rate for endocrowns.

Micro-Viscometer for Measuring Shear-Varying Blood Viscosity over a Wide-Ranging Shear Rate

PubMed Central

Kim, Byung Jun; Lee, Seung Yeob; Jee, Solkeun; Atajanov, Arslan; Yang, Sung

2017-01-01

In this study, a micro-viscometer is developed for measuring shear-varying blood viscosity over a wide-ranging shear rate. The micro-viscometer consists of 10 microfluidic channel arrays, each of which has a different micro-channel width. The proposed design enables the retrieval of 10 different shear rates from a single flow rate, thereby enabling the measurement of shear-varying blood viscosity with a fixed flow rate condition. For this purpose, an optimal design that guarantees accurate viscosity measurement is selected from a parametric study. The functionality of the micro-viscometer is verified by both numerical and experimental studies. The proposed micro-viscometer shows 6.8% (numerical) and 5.3% (experimental) in relative error when compared to the result from a standard rotational viscometer. Moreover, a reliability test is performed by repeated measurement (N = 7), and the result shows 2.69 ± 2.19% for the mean relative error. Accurate viscosity measurements are performed on blood samples with variations in the hematocrit (35%, 45%, and 55%), which significantly influences blood viscosity. Since the blood viscosity correlated with various physical parameters of the blood, the micro-viscometer is anticipated to be a significant advancement for realization of blood on a chip. PMID:28632151

Blood (Breath) Alcohol Concentration Rates of College Football Fans on Game Day

ERIC Educational Resources Information Center

Glassman, Tavis; Braun, Robert; Reindl, Diana M.; Whewell, Aubrey

2011-01-01

The purpose of this study was to determine the Blood (breath) Alcohol Concentration (BrAC) rates of college football fans on game day. Researchers employed a time-series study design, collecting data at home football games at a large university in the Midwest. Participants included 536 individuals (64.4% male) ages 18-83 (M = 28.44, SD = 12.32).…

Divergent Activities in History Teaching: History Teachers' Perceptions and an Initiative for Evaluation as Preparing Rating Scale

ERIC Educational Resources Information Center

Tokdemir, Muhammet Ahmet

2017-01-01

Assessment is one of the basic elements of teaching. However, there are not enough studies on the evaluation of divergent questions, particularly, in history education. Therefore, after reviewing the past and current literature on the topic, this study describes the design and implementation of a rating scale which can be used in the evaluation of…

The Case for Use of Simple Difference Scores to Test the Significance of Differences in Mean Rates of Change in Controlled Repeated Measurements Designs

ERIC Educational Resources Information Center

Overall, John E.; Tonidandel, Scott

2010-01-01

A previous Monte Carlo study examined the relative powers of several simple and more complex procedures for testing the significance of difference in mean rates of change in a controlled, longitudinal, treatment evaluation study. Results revealed that the relative powers depended on the correlation structure of the simulated repeated measurements.…

Effects of an Introductory Letter on Response Rates to a Teen/Parent Telephone Health Survey

ERIC Educational Resources Information Center

Woodruff, Susan I.; Mayer, Joni A.; Clapp, Elizabeth

2006-01-01

The authors conducted a pilot study in preparation for a larger investigation that will rely on telephone surveys to assess select health behaviors of teens and their parents, with a focus on indoor tanning. This study used a randomized design to assess the impact of a presurvey letter on response rates to a telephone survey, as well as prevalence…

From orbital debris capture systems through internal combustion engines on Mars

NASA Technical Reports Server (NTRS)

1991-01-01

The investigation and conceptualization of an orbital debris collector was the primary area of design. In addition, an alternate structural design for Space Station Freedom and systems supporting resource utilization at Mars and the moon were studied. Hardware for production of oxygen from simulate Mars atmosphere was modified to permit more reliable operation at low pressures (down to 10 mb). An internal combustion engine was altered to study how Mars atmosphere could be used as a diluent to control combustion temperatures and avoid excess Mars propellant production requirements that would result from either methane-rich or oxygen-rich, methane-oxygen combustion. An elastic loop traction system that could be used for lunar construction vehicles was refined to permit testing. A parabolic heat rejection radiator system was designed and built to determine whether it was capable of increasing heat rejection rates during lunar daytime operation. In addition, an alternate space station truss design, utilizing a pre-integrated concept, was studied and found to reduce estimate extravehicular activity (EVA) time and increase the structural integrity when compared to the original Warren truss concept. An orbital-debris-capturing spacecraft design which could be mated with the Orbital Maneuvering Vehicle was studied. The design identified Soviet C-1B boosters as the best targets of opportunity in Earth orbits between an altitude of 900 km and 1100 km and at an inclination of 82.9 deg. A dual robot pallet, which could be spun to match the tumbling rate of the C-1B booster, was developed as the conceptual design.

Reach, engagement, and effectiveness: a systematic review of evaluation methodologies used in health promotion via social networking sites.

PubMed

Lim, Megan S C; Wright, Cassandra J C; Carrotte, Elise R; Pedrana, Alisa E

2016-02-01

Issue addressed Social networking sites (SNS) are increasingly popular platforms for health promotion. Advancements in SNS health promotion require quality evidence; however, interventions are often not formally evaluated. This study aims to describe evaluation practices used in SNS health promotion. Methods A systematic review was undertaken of Medline, PsycINFO, Scopus, EMBASE, CINAHL Plus, Communication and Mass Media Complete, and Cochrane Library databases. Articles published between 2006 and 2013 describing any health promotion intervention delivered using SNS were included. Results Forty-seven studies were included. There were two main evaluation approaches: closed designs (n=23), which used traditional research designs and formal recruitment procedures; and open designs (n=19), which evaluated the intervention in a real-world setting, allowing unknown SNS users to interact with the content without enrolling in research. Closed designs were unable to assess reach and engagement beyond their research sample. Open designs often relied on weaker study designs with no use of objective outcome measures and yielded low response rates. Conclusions Barriers to evaluation included low participation rates, high attrition, unknown representativeness and lack of comparison groups. Acceptability was typically assessed among those engaged with the intervention, with limited population data available to accurately assess intervention reach. Few studies were able to assess uptake of the intervention in a real-life setting while simultaneously assessing effectiveness of interventions with research rigour. So what? Through use of quasi-experimental or well designed before-after evaluations, in combination with detailed engagement metrics, it is possible to balance assessment of effectiveness and reach to evaluate SNS health promotion.

Incorporating lower grade toxicity information into dose finding designs

PubMed Central

Iasonos, Alexia; Zohar, Sarah; O’Quigley, John

2012-01-01

Background Toxicity grades underlie the definition of a dose limiting toxicity (DLT) but in the majority of phase I designs, the information contained in the individual grades is not used. Some authors have argued that it may be more appropriate to consider a polytomous rather than dichotomous response. Purpose We investigate whether the added information on individual grades can improve the operating characteristics of the Continual Reassessment Method (CRM). Methods We compare the original CRM design for a binary response with two stage CRM designs which make di erent use of lower-grade toxicity information via simulations. Specifically we study; a two-stage design that utilizes lower-grade toxicities in the first stage only, during the initial non model-based escalation, and two-stage designs where lower grades are used throughout the trial via explicit models. We postulate a model relating the rates of lower grade toxicities to the rate of DLTs, or assume the relative rates of low to high grade toxicities is unknown. The designs were compared in terms of accuracy, patient allocation and precision. Results Significant gains can be achieved when using grades in the first stage of a two-stage design. Otherwise, only modest improvements are seen when the information on grades is exploited via the use of explicit models, where the parameters are known precisely. CRM with some use of grade information, increases the number of patients treated at the MTD by approximately 5%. The additional information from lower grades can lead to a small increase in the precision of our estimate of the MTD. Limitations Our comparisons are not exhaustive and it would be worth studying other models and situations. Conclusions Although, the gains in performance were not as great as we had hoped, we observed no cases where the performance of CRM was poorer. Our recommendation is that investigators might consider using graded toxicities at the design stage. PMID:21835856

Impact of a value-based insurance design for back pain on health plan member satisfaction and its implications for patient outcomes.

PubMed

Maeng, Daniel D; Fisher, Dorothy Y; Graboski, Anthony; Allison, Peiling L; Rodriguez, Jennifer M; Starr, Alison E; Tomcavage, Janet F; Davis, Duane E

2015-06-01

Back pain is one of the most common reasons for seeking care, and physical therapy (PT) can be an effective treatment option. However, PT coverage for back pain varies widely among private health plans, usually requiring high cost sharing, thereby potentially leading to member dissatisfaction and worse outcomes. In this study, a quasi-experimental design was used to estimate the impact of a new value-based insurance design for back pain-related PT on selected Consumer Assessment of Healthcare Providers and Systems survey items. Under this design, eligible members receive a bundle of 5 PT sessions for a 1-time co-payment; if deemed necessary, the bundle is renewable for 1 additional co-payment. The results indicate that the proportion of members reporting the highest satisfaction rating was higher by about 6 to 10 percentage points among those who received the PT bundle. The data also indicate that those PT bundle members who reported the highest satisfaction rating had improvements in their functional status scores that were roughly 3 to 4 times higher than those who reported a lower satisfaction rating. These findings suggest that providing a value-based insurance design for back pain-related PT can potentially improve health plan members' care experiences and their overall satisfaction. Further study is needed to determine its impact on back pain-related medical care utilization and cost of care.

Correlation between safety assessments in the driver-car interaction design process.

PubMed

Broström, Robert; Bengtsson, Peter; Axelsson, Jakob

2011-05-01

With the functional revolution in modern cars, evaluation methods to be used in all phases of driver-car interaction design have gained importance. It is crucial for car manufacturers to discover and solve safety issues early in the interaction design process. A current problem is thus to find a correlation between the formative methods that are used during development and the summative methods that are used when the product has reached the customer. This paper investigates the correlation between efficiency metrics from summative and formative evaluations, where the results of two studies on sound and navigation system tasks are compared. The first, an analysis of the J.D. Power and Associates APEAL survey, consists of answers given by about two thousand customers. The second, an expert evaluation study, was done by six evaluators who assessed the layouts by task completion time, TLX and Nielsen heuristics. The results show a high degree of correlation between the studies in terms of task efficiency, i.e. between customer ratings and task completion time, and customer ratings and TLX. However, no correlation was observed between Nielsen heuristics and customer ratings, task completion time or TLX. The results of the studies introduce a possibility to develop a usability evaluation framework that includes both formative and summative approaches, as the results show a high degree of consistency between the different methodologies. Hence, combining a quantitative approach with the expert evaluation method, such as task completion time, should be more useful for driver-car interaction design. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Utility of numerical and visual analog scales for evaluating the post-operative pain in rural patients

PubMed Central

Mudgalkar, Nikhil; Bele, Samir D; Valsangkar, Sameer; Bodhare, Trupti N; Gorre, Mahipal

2012-01-01

Background: Visual analog scales (VAS) and numeric analog scales (NAS) are used to assess post-operative pain, but few studies indicate their usefulness in rural illiterate population in India. Aims: This study was designed to 1) Compare the impact of literacy on the ability to indicate pain rating on VAS and NAS in post-operative rural patients. 2) Assess the level of agreement between the pain scales. Setting and Design: Cross sectional, hospital based study. Methods: Informed consent was obtained from patients prior to undergoing surgical procedures in a teaching hospital. Post surgery, patients who were conscious and coherent, were asked to rate pain on both VAS and NAS. The pain ratings were obtained within 24 hours of surgery and within 5 minutes of each other. Statistical Methods: Percentages, chi square test, regression analysis. Results: A total of 105 patients participated in the study. 43 (41%) of the sample was illiterate. 82 (78.1%) were able to rate pain on VAS while 81 (77.1%) were able to rate pain on NAS. There was no significant association between pain ratings and type of surgery, duration of surgery and nature of anaesthesia. In multivariate analysis, age, sex and literacy had no significant association with the ability to rate pain on VAS (P value 0.652, 0.967, 0.328 respectively). Similarly, no significant association was obtained between age, sex and literacy and ability to rate pain on NAS (P value 0.713, 0.405, 0.875 respectively). Correlation coefficient between the scales was 0.693. Conclusion: VAS and NAS can be used interchangeably in Indian rural population as post-operative pain assessment tools irrespective of literacy status. PMID:23325940

Permanent magnet motors

NASA Astrophysics Data System (ADS)

Richter, E.

1984-09-01

The work deals with the design and analysis study for the conceptual design of an economical high efficiency ac motor based on permanent magnets. The design and trade off studies have covered the material considerations, the design tradeoff options as well as transient and steady state performance considerations, and other options. The baseline comparison is the high efficiency induction motor. The permanent magnet (PM) motor must fit into the same frame size and surpass the induction motor on a life cost basis that includes 2.5 years of operation at a 50% duty cycle. It is shown that a motor based upon ferrite magnets does meet the objectives of the program in ratings of up to 25 hp. A 7.5 motor design is carried through the conceptual design stage.

Mortality rates among Arab Americans in Michigan.

PubMed

Dallo, Florence J; Schwartz, Kendra; Ruterbusch, Julie J; Booza, Jason; Williams, David R

2012-04-01

The objectives of this study were to: (1) calculate age-specific and age-adjusted cause-specific mortality rates for Arab Americans; and (2) compare these rates with those for blacks and whites. Mortality rates were estimated using Michigan death certificate data, an Arab surname and first name list, and 2000 U.S. Census data. Age-specific rates, age-adjusted all-cause and cause-specific rates were calculated. Arab Americans (75+) had higher mortality rates than whites and blacks. Among men, all-cause and cause-specific mortality rates for Arab Americans were in the range of whites and blacks. However, Arab American men had lower mortality rates from cancer and chronic lower respiratory disease compared to both whites and blacks. Among women, Arab Americans had lower mortality rates from heart disease, cancer, stroke, and diabetes than whites and blacks. Arab Americans are growing in number. Future study should focus on designing rigorous separate analyses for this population.

Mortality Rates Among Arab Americans in Michigan

PubMed Central

Schwartz, Kendra; Ruterbusch, Julie J.; Booza, Jason; Williams, David R.

2014-01-01

The objectives of this study were to: (1) calculate age-specific and age-adjusted cause-specific mortality rates for Arab Americans; and (2) compare these rates with those for blacks and whites. Mortality rates were estimated using Michigan death certificate data, an Arab surname and first name list, and 2000 U.S. Census data. Age-specific rates, age-adjusted all-cause and cause-specific rates were calculated. Arab Americans (75+) had higher mortality rates than whites and blacks. Among men, all-cause and cause-specific mortality rates for Arab Americans were in the range of whites and blacks. However, Arab American men had lower mortality rates from cancer and chronic lower respiratory disease compared to both whites and blacks. Among women, Arab Americans had lower mortality rates from heart disease, cancer, stroke, and diabetes than whites and blacks. Arab Americans are growing in number. Future study should focus on designing rigorous separate analyses for this population. PMID:21318619

Research on the performance of low-lift diving tubular pumping system by CFD and Test

NASA Astrophysics Data System (ADS)

Xia, Chenzhi; Cheng, Li; Liu, Chao; Zhou, Jiren; Tang, Fangping; Jin, Yan

2016-11-01

Post-diving tubular pump is always used in large-discharge & low-head irrigation or storm drainage pumping station, its impeller and motor share the same shaft. Considering diving tubular pump system's excellent hydraulic performance, compact structure, good noise resistance and low operating cost, it is used in Chinese pump stations. To study the hydraulic performance and pressure fluctuation of inlet and outlet passage in diving tubular pump system, both of steady and unsteady full flow fields are numerically simulated at three flow rate conditions by using CFD commercial software. The asymmetry of the longitudinal structure of inlet passage affects the flow pattern on outlet. Especially at small flow rate condition, structural asymmetry will result in the uneven velocity distribution on the outlet of passage inlet. The axial velocity distribution uniformity increases as the flow rate increases on the inlet of passage inlet, and there is a positive correlation between hydraulic loss in the passage inlet and flow rate's quadratic. The axial velocity distribution uniformity on the outlet of passage inlet is 90% at design flow rate condition. The predicted result shows the same trend with test result, and the range of high efficiency area between predicted result and test result is almost identical. The dominant frequency of pressure pulsation is low frequency in inlet passage at design condition. The dominant frequency is high frequency in inlet passage at small and large flow rate condition. At large flow rate condition, the flow pattern is significantly affected by the rotation of impeller in inlet passage. At off-design condition, the pressure pulsation is strong at outlet passage. At design condition, the dominant frequency is 35.57Hz, which is double rotation frequency.

Basin view geothermal heating district, Klamath Falls, Oregon. Conceptual design and economic-feasibility study report

NASA Astrophysics Data System (ADS)

1981-07-01

The findings of a feasibility study performed for Basin View Heating District in Klamath Falls, Oregon are reported. The physical, economic, and political feasibility of establishing a geothermal heating district to provide space heat to housing units in the Basin View Development of Klamath Falls are determined. Of the several systems considered, all are physically feasible. The project is politically feasible if the owner complies with governmental requirements. Economic feasibility is based on considerations of money value rates, tax rates and expected rates of return, which are dependent on government and money markets. For analysis a money value rate of 21% and an owner's marginal tax rate of 35% were adopted.

Effects of protein or amino-acid supplementation on the physical growth of young children in low-income countries

PubMed Central

Arsenault, Joanne E; Brown, Kenneth H

2017-01-01

Abstract Child growth stunting is common in low-income countries, possibly due to insufficient protein intakes. Most previous studies have concluded that children’s protein intakes are adequate in relation to estimated requirements, but these studies did not consider issues of protein digestibility and effects of infection on dietary protein utilization. Using an alternative approach to assess the possible role of protein inadequacy in children’s growth restriction, the results of 18 intervention trials in which supplementary protein or amino acids were provided to children ages 6–35 months and growth outcomes were reviewed. Eight studies conducted in hospitalized children recovering from acute malnutrition found that the recommended protein intake levels for healthy children supported normal growth rates, but higher intakes were needed for accelerated rates of “catch-up” growth. Ten community-based studies did not demonstrate a consistent benefit of supplemental protein on children’s growth. However, weaknesses in the study designs limit the conclusions that can be drawn from these studies, and additional appropriately designed trials are needed to answer this question definitively. Recommendations for optimizing future study designs are provided herein. PMID:28938793

Flexible sequential designs for multi-arm clinical trials.

PubMed

Magirr, D; Stallard, N; Jaki, T

2014-08-30

Adaptive designs that are based on group-sequential approaches have the benefit of being efficient as stopping boundaries can be found that lead to good operating characteristics with test decisions based solely on sufficient statistics. The drawback of these so called 'pre-planned adaptive' designs is that unexpected design changes are not possible without impacting the error rates. 'Flexible adaptive designs' on the other hand can cope with a large number of contingencies at the cost of reduced efficiency. In this work, we focus on two different approaches for multi-arm multi-stage trials, which are based on group-sequential ideas, and discuss how these 'pre-planned adaptive designs' can be modified to allow for flexibility. We then show how the added flexibility can be used for treatment selection and sample size reassessment and evaluate the impact on the error rates in a simulation study. The results show that an impressive overall procedure can be found by combining a well chosen pre-planned design with an application of the conditional error principle to allow flexible treatment selection. Copyright © 2014 John Wiley & Sons, Ltd.

Optimal design of active spreading systems to remediate sorbing groundwater contaminants in situ

NASA Astrophysics Data System (ADS)

Piscopo, Amy N.; Neupauer, Roseanna M.; Kasprzyk, Joseph R.

2016-07-01

The effectiveness of in situ remediation to treat contaminated aquifers is limited by the degree of contact between the injected treatment chemical and the groundwater contaminant. In this study, candidate designs that actively spread the treatment chemical into the contaminant are generated using a multi-objective evolutionary algorithm. Design parameters pertaining to the amount of treatment chemical and the duration and rate of its injection are optimized according to objectives established for the remediation - maximizing contaminant degradation while minimizing energy and material requirements. Because groundwater contaminants have different reaction and sorption properties that influence their ability to be degraded with in situ remediation, optimization was conducted for six different combinations of reaction rate coefficients and sorption rates constants to represent remediation of the common groundwater contaminants, trichloroethene, tetrachloroethene, and toluene, using the treatment chemical, permanganate. Results indicate that active spreading for contaminants with low reaction rate coefficients should be conducted by using greater amounts of treatment chemical mass and longer injection durations relative to contaminants with high reaction rate coefficients. For contaminants with slow sorption or contaminants in heterogeneous aquifers, two different design strategies are acceptable - one that injects high concentrations of treatment chemical mass over a short duration or one that injects lower concentrations of treatment chemical mass over a long duration. Thus, decision-makers can select a strategy according to their preference for material or energy use. Finally, for scenarios with high ambient groundwater velocities, the injection rate used for active spreading should be high enough for the groundwater divide to encompass the entire contaminant plume.

Accounting for Epistemic Uncertainty in Mission Supportability Assessment: A Necessary Step in Understanding Risk and Logistics Requirements

NASA Technical Reports Server (NTRS)

Owens, Andrew; De Weck, Olivier L.; Stromgren, Chel; Goodliff, Kandyce; Cirillo, William

2017-01-01

Future crewed missions to Mars present a maintenance logistics challenge that is unprecedented in human spaceflight. Mission endurance – defined as the time between resupply opportunities – will be significantly longer than previous missions, and therefore logistics planning horizons are longer and the impact of uncertainty is magnified. Maintenance logistics forecasting typically assumes that component failure rates are deterministically known and uses them to represent aleatory uncertainty, or uncertainty that is inherent to the process being examined. However, failure rates cannot be directly measured; rather, they are estimated based on similarity to other components or statistical analysis of observed failures. As a result, epistemic uncertainty – that is, uncertainty in knowledge of the process – exists in failure rate estimates that must be accounted for. Analyses that neglect epistemic uncertainty tend to significantly underestimate risk. Epistemic uncertainty can be reduced via operational experience; for example, the International Space Station (ISS) failure rate estimates are refined using a Bayesian update process. However, design changes may re-introduce epistemic uncertainty. Thus, there is a tradeoff between changing a design to reduce failure rates and operating a fixed design to reduce uncertainty. This paper examines the impact of epistemic uncertainty on maintenance logistics requirements for future Mars missions, using data from the ISS Environmental Control and Life Support System (ECLS) as a baseline for a case study. Sensitivity analyses are performed to investigate the impact of variations in failure rate estimates and epistemic uncertainty on spares mass. The results of these analyses and their implications for future system design and mission planning are discussed.

A robust variable sampling time BLDC motor control design based upon μ-synthesis.

PubMed

Hung, Chung-Wen; Yen, Jia-Yush

2013-01-01

The variable sampling rate system is encountered in many applications. When the speed information is derived from the position marks along the trajectory, one would have a speed dependent sampling rate system. The conventional fixed or multisampling rate system theory may not work in these cases because the system dynamics include the uncertainties which resulted from the variable sampling rate. This paper derived a convenient expression for the speed dependent sampling rate system. The varying sampling rate effect is then translated into multiplicative uncertainties to the system. The design then uses the popular μ-synthesis process to achieve a robust performance controller design. The implementation on a BLDC motor demonstrates the effectiveness of the design approach.

A Robust Variable Sampling Time BLDC Motor Control Design Based upon μ-Synthesis

PubMed Central

Yen, Jia-Yush

2013-01-01

The variable sampling rate system is encountered in many applications. When the speed information is derived from the position marks along the trajectory, one would have a speed dependent sampling rate system. The conventional fixed or multisampling rate system theory may not work in these cases because the system dynamics include the uncertainties which resulted from the variable sampling rate. This paper derived a convenient expression for the speed dependent sampling rate system. The varying sampling rate effect is then translated into multiplicative uncertainties to the system. The design then uses the popular μ-synthesis process to achieve a robust performance controller design. The implementation on a BLDC motor demonstrates the effectiveness of the design approach. PMID:24327804

Improved Lunar Lander Handling Qualities Through Control Response Type and Display Enhancements

NASA Technical Reports Server (NTRS)

Mueller, Eric Richard; Bilimoria, Karl D.; Frost, Chad Ritchie

2010-01-01

A piloted simulation that studied the handling qualities for a precision lunar landing task from final approach to touchdown is presented. A vehicle model based on NASA's Altair Lunar Lander was used to explore the design space around the nominal vehicle configuration to determine which combination of factors provides satisfactory pilot-vehicle performance and workload; details of the control and propulsion systems not available for that vehicle were derived from Apollo Lunar Module data. The experiment was conducted on a large motion base simulator. Eight Space Shuttle and Apollo pilot astronauts and three NASA test pilots served as evaluation pilots, providing Cooper-Harper ratings, Task Load Index ratings and qualitative comments. Each pilot flew seven combinations of control response types and three sets of displays, including two varieties of guidance and a nonguided approach. The response types included Rate Command with Attitude Hold, which was used in the original Apollo Moon landings, a Velocity Increment Command response type designed for up-and-away flight, three response types designed specifically for the vertical descent portion of the trajectory, and combinations of these. It was found that Velocity Increment Command significantly improved handling qualities when compared with the baseline Apollo design, receiving predominantly Level 1 ratings. This response type could be flown with or without explicit guidance cues, something that was very difficult with the baseline design, and resulted in approximately equivalent touchdown accuracies and propellant burn as the baseline response type. The response types designed to be used exclusively in the vertical descent portion of the trajectory did not improve handling qualities.

An Impact Study of the Design of Exergaming Parameters on Body Intensity from Objective and Gameplay-Based Player Experience Perspectives, Based on Balance Training Exergame

PubMed Central

2013-01-01

Kinect-based exergames allow players to undertake physical exercise in an interactive manner with visual stimulation. Previous studies focused on investigating physical fitness based on calories or heart rate to ascertain the effectiveness of exergames. However, designing an exergame for specific training purposes, with intensity levels suited to the needs and skills of the players, requires the investigation of motion performance to study player experience. This study investigates how parameters of a Kinect-based exergame, combined with balance training exercises, influence the balance control ability and intensity level the player can tolerate, by analyzing both objective and gameplay-based player experience, and taking enjoyment and difficulty levels into account. The exergame tested required participants to maintain their balance standing on one leg within a posture frame (PF) while a force plate evaluated the player's balance control ability in both static and dynamic gaming modes. The number of collisions with the PF depended on the frame's travel time for static PFs, and the leg-raising rate and angle for dynamic PFs. In terms of center of pressure (COP) metrics, significant impacts were caused by the frame's travel time on MDIST-AP for static PFs, and the leg-raising rate on MDIST-ML and TOTEX for dynamic PFs. The best static PF balance control performance was observed with a larger frame offset by a travel time of 2 seconds, and the worst performance with a smaller frame and a travel time of 1 second. The best dynamic PF performance was with a leg-raising rate of 1 second at a 45-degree angle, while the worst performance was with a rate of 2 seconds at a 90-degree angle. The results demonstrated that different evaluation methods for player experience could result in different findings, making it harder to study the design of those exergames with training purposes based on player experience. PMID:23922716

Case-spouse control design in practice: an experience in estimating smoking and chronic obstructive pulmonary disease deaths in Chinese adults.

PubMed

Jiang, Jingmei; Liu, Boqi; Sitas, Freddy; Zeng, Xianjia; Chen, Junshi; Han, Wei; Zou, Xiaonong; Wu, Yanping; Zhao, Ping; Li, Junyao

2010-05-01

We assessed the effect of smoking on death from chronic obstructive pulmonary disease (COPD) in China by employing a large population-based, case-spouse control study design using data from a nationwide survey of mortality. During 1989-1991, a nationwide retrospective survey of mortality was conducted in China. For approximately 1,000,000 adults dying from all causes during 1986-1988, their surviving spouses or other informants provided detailed information about their own as well as the deceased person's smoking history. For this study, 183,393 individuals who died of COPD at age > or = 40 years were taken as cases, while 272,984 sex-matched surviving spouses of subjects who died from any cause were taken as controls. COPD death rates for smokers were more than twice as high as those of non-smokers, with a dose-response risk pattern, despite the fact that COPD death rates varied widely by region and age. Tobacco accounted for 41.4% of COPD deaths in men, but only 13.5% of those in women, who had a lower rate of smoking. A case-spouse control study, as an alternative design, is valid and feasible in utilizing information from population-based, retrospective mortality survey data for an analytical epidemiological study of disease etiology. Copyright 2010 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.

An estimation of finger-tapping rates and load capacities and the effects of various factors.

PubMed

Ekşioğlu, Mahmut; İşeri, Ali

2015-06-01

The aim of this study was to estimate the finger-tapping rates and finger load capacities of eight fingers (excluding thumbs) for a healthy adult population and investigate the effects of various factors on tapping rate. Finger-tapping rate, the total number of finger taps per unit of time, can be used as a design parameter of various products and also as a psychomotor test for evaluating patients with neurologic problems. A 1-min tapping task was performed by 148 participants with maximum volitional tempo for each of eight fingers. For each of the tapping tasks, the participant with the corresponding finger tapped the associated key in the standard position on the home row of a conventional keyboard for touch typing. The index and middle fingers were the fastest fingers for both hands, and little fingers the slowest. All dominant-hand fingers, except little finger, had higher tapping rates than the fastest finger of the nondominant hand. Tapping rate decreased with age and smokers tapped faster than nonsmokers. Tapping duration and exercise had also significant effect on tapping rate. Normative data of tapping rates and load capacities of eight fingers were estimated for the adult population. In designs of psychomotor tests that require the use of tapping rate or finger load capacity data, the effects of finger, age, smoking, and tapping duration need to be taken into account. The findings can be used for ergonomic designs requiring finger-tapping capacity and also as a reference in psychomotor tests. © 2015, Human Factors and Ergonomics Society.

Epidemiology of fetal alcohol syndrome in a South African community in the Western Cape Province.

PubMed Central

May, P A; Brooke, L; Gossage, J P; Croxford, J; Adnams, C; Jones, K L; Robinson, L; Viljoen, D

2000-01-01

OBJECTIVES: This study determined the characteristics of fetal alcohol syndrome in a South African community, and methodology was designed for the multidisciplinary study of fetal alcohol syndrome in developing societies. METHODS: An active case ascertainment, 2-tier methodology was used among 992 first-grade pupils. A case-control design, using measures of growth, development, dysmorphology, and maternal risk, delineated characteristics of children with fetal alcohol syndrome. RESULTS: A high rate of fetal alcohol syndrome was found in the schools--40.5 to 46.4 per 1000 children aged 5 to 9 years--and age-specific community rates (ages 6-7) were 39.2 to 42.9. These rates are 18 to 141 times greater than in the United States. Rural residents had significantly more fetal alcohol syndrome. After control for ethnic variation, children with fetal alcohol syndrome had traits similar to those elsewhere: poor growth and development, congruent dysmorphology, and lower intellectual functioning. CONCLUSIONS: This study documented the highest fetal alcohol syndrome rate to date in an overall community population. Fetal alcohol syndrome initiatives that incorporate innovative sampling and active case ascertainment methods can be used to obtain timely and accurate data among developing populations. PMID:11111264

Guidelines for Design and Test of a Built-In Self Test (BIST) Circuit For Space Radiation Studies of High-Speed IC Technologies

NASA Technical Reports Server (NTRS)

Carts, M. A.; Marshall, P. W.; Reed, R.; Curie, S.; Randall, B.; LaBel, K.; Gilbert, B.; Daniel, E.

2006-01-01

Serial Bit Error Rate Testing under radiation to characterize single particle induced errors in high-speed IC technologies generally involves specialized test equipment common to the telecommunications industry. As bit rates increase, testing is complicated by the rapidly increasing cost of equipment able to test at-speed. Furthermore as rates extend into the tens of billions of bits per second test equipment ceases to be broadband, a distinct disadvantage for exploring SEE mechanisms in the target technologies. In this presentation the authors detail the testing accomplished in the CREST project and apply the knowledge gained to establish a set of guidelines suitable for designing arbitrarily high speed radiation effects tests.

Investigating rate-limiting barriers to nanoscale nonviral gene transfer with nanobiophotonics

NASA Astrophysics Data System (ADS)

Chen, Hunter H.

Nucleic acids are a novel class of therapeutics poised to address many unmet clinical needs. Safe and efficient delivery remains a significant challenge that has delayed the realization of the full therapeutic potential of nucleic acids. Nanoscale nonviral vectors offer an attractive alternative to viral vectors as natural and synthetic polymers or polypeptides may be rationally designed to meet the unique demands of individual applications. A mechanistic understanding of cellular barriers is necessary to develop guidelines for designing custom gene carriers which are expected to greatly impact this delivery challenge. The work herein focused on the relationships among nanocomplex stability, intracellular trafficking and unpacking kinetics, and DNA degradation. Ultrasensitive nanosensors based on QD-FRET were developed to characterize the biophysical properties of nanocomplexes and study these rate-limiting steps. Quantitative image analysis enabled the distributions of the subpopulation of condensed or released DNA to be determined within the major cellular compartments encountered during gene transfer. The steady state stability and unpacking kinetics within these compartments were found to impact transgene expression, elucidating multiple design strategies to achieve efficient gene transfer. To address enzymatic barriers, a novel two-step QD-FRET nanosensor was developed to analyze unpacking and DNA degradation simultaneously, which has not been accomplished previously. Bioresponsive strategies such as disulfide crosslinking and thermosensitivity were evaluated by QD-FRET and quantitative compartmental analysis as case studies to determine appropriate design specifications for thiolated polymers and thermoresponsive polypeptides. Relevant nanobiophotonic tools were developed as a platform to study major rate-limiting barriers to nanomedicine and demonstrated the feasibility of using mechanistic information gained from these tools to guide the rational design of gene carriers and achieve the desired properties that enable efficient gene transfer.

Route-Specific Passage Proportions and Survival Rates for Fish Passing through John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011

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

Ploskey, Gene R.; Weiland, Mark A.; Carlson, Thomas J.

This report fulfills a request of the U.S. Army Engineer District, Portland, Oregon, to produce an interim report of estimates of route-specific fish passage proportions and survival rates for lower Columbia River dams in 2010 and 2011. The estimates are needed to update the Compass Model for the Columbia River Treaty and the new Biological Opinion before detail technical reports are published in late 2012. This report tabulates route-specific fish-passage proportions and survival rates for steelhead and Chinook salmon smolts passing through various sampled routes at John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011. Resultsmore » were compiled from analyses of data acquired in spring 2010 and 2011 studies that were specifically designed to estimate dam-passage and forebay-to-tailrace survival rates, travel time metrics, and spill passage efficiency, as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the Columbia Basin Fish Accords. The study designs allowed for estimation of route-specific fish passage proportions and survival rates as well as estimation of forebay-passage survival, all of which are summarized herein.« less

Prioritizing the mHealth Design Space: A Mixed-Methods Analysis of Smokers’ Perspectives

PubMed Central

BlueSpruce, June; Catz, Sheryl L; McClure, Jennifer B

2016-01-01

Background Smoking remains the leading cause of preventable disease and death in the United States. Therefore, researchers are constantly exploring new ways to promote smoking cessation. Mobile health (mHealth) technologies could be effective cessation tools. Despite the availability of commercial quit-smoking apps, little research to date has examined smokers’ preferred treatment intervention components (ie, design features). Honoring these preferences is important for designing programs that are appealing to smokers and may be more likely to be adopted and used. Objective The aim of this study was to understand smokers’ preferred design features of mHealth quit-smoking tools. Methods We used a mixed-methods approach consisting of focus groups and written surveys to understand the design preferences of adult smokers who were interested in quitting smoking (N=40). Focus groups were stratified by age to allow differing perspectives to emerge between older (>40 years) and younger (<40 years) participants. Focus group discussion included a “blue-sky” brainstorming exercise followed by participant reactions to contrasting design options for communicating with smokers, providing social support, and incentivizing program use. Participants rated the importance of preselected design features on an exit survey. Qualitative analyses examined emergent discussion themes and quantitative analyses compared feature ratings to determine which were perceived as most important. Results Participants preferred a highly personalized and adaptive mHealth experience. Their ideal mHealth quit-smoking tool would allow personalized tracking of their progress, adaptively tailored feedback, and real-time peer support to help manage smoking cravings. Based on qualitative analysis of focus group discussion, participants preferred pull messages (ie, delivered upon request) over push messages (ie, sent automatically) and preferred interaction with other smokers through closed social networks. Preferences for entertaining games or other rewarding incentives to encourage program use differed by age group. Based on quantitative analysis of surveys, participants rated the importance of select design features significantly differently (P<.001). Design features rated as most important included personalized content, the ability to track one’s progress, and features designed to help manage nicotine withdrawal and medication side effects. Design features rated least important were quit-smoking videos and posting on social media. Communicating with stop-smoking experts was rated more important than communicating with family and friends about quitting (P=.03). Perceived importance of various design features varied by age, experience with technology, and frequency of smoking. Conclusions Future mHealth cessation aids should be designed with an understanding of smokers’ needs and preferences for these tools. Doing so does not guarantee treatment effectiveness, but balancing user preferences with best-practice treatment considerations could enhance program adoption and improve treatment outcomes. Grounded in the perspectives of smokers, we identify several design considerations, which should be prioritized when designing future mHealth cessation tools and which warrant additional empirical validation. PMID:27496593

Review of atrazine sampling by polar organic chemical integrative samplers and Chemcatcher.

PubMed

Booij, Kees; Chen, Sunmao

2018-04-24

A key success factor for the performance of passive samplers is the proper calibration of sampling rates. Sampling rates for a wide range of polar organic compounds are available for Chemcatchers and polar organic chemical integrative samplers (POCIS), but the mechanistic models that are needed to understand the effects of exposure conditions on sampling rates need improvement. Literature data on atrazine sampling rates by these samplers were reviewed with the aim of assessing what can be learned from literature reports of this well-studied compound and identifying knowledge gaps related to the effects of flow and temperature. The flow dependency of sampling rates could be described by a mass transfer resistance model with 1 (POCIS) or 2 (Chemcatcher) adjustable parameters. Literature data were insufficient to evaluate the temperature effect on the sampling rates. An evaluation of reported sampler configurations showed that standardization of sampler design can be improved: for POCIS with respect to surface area and sorbent mass, and for Chemcatcher with respect to housing design. Several reports on atrazine sampling could not be used because the experimental setups were insufficiently described with respect to flow conditions. Recommendations are made for standardization of sampler layout and documentation of flow conditions in calibration studies. Environ Toxicol Chem 2018;9999:1-13. © 2018 SETAC. © 2018 SETAC.

Nitrate Removal Rates in Denitrifying Bioreactors During Storm Flows

NASA Astrophysics Data System (ADS)

Pluer, W.; Walter, T.

2017-12-01

Field denitrifying bioreactors are designed to reduce excess nitrate (NO3-) pollution in runoff from agricultural fields. Field bioreactors saturate organic matter to create conditions that facilitate microbial denitrification. Prior studies using steady flow in lab-scale bioreactors showed that a hydraulic retention time (HRT) between 4 and 10 hours was optimal for reducing NO3- loads. However, during storm-induced events, flow rate and actual HRT fluctuate. These fluctuations have the potential to disrupt the system in significant ways that are not captured by the idealized steady-flow HRT models. The goal of this study was to investigate removal rate during dynamic storm flows of variable rates and durations. Our results indicate that storm peak flow and duration were not significant controlling variables. Instead, we found high correlations (p=0.004) in average removal rates between bioreactors displaying a predominantly uniform flow pattern compared with bioreactors that exhibited preferential flow (24.4 and 21.4 g N m-3 d-1, respectively). This suggests that the internal flow patterns are a more significant driver of removal rate than external factors of the storm hydrograph. Designing for flow patterns in addition to theoretical HRT will facilitate complete mixing within the bioreactors. This will help maximize excess NO3- removal during large storm-induced runoff events.

Investigation of a 0.6 hub-tip radius-ratio transonic turbine designed for secondary-flow study I : design and experimental performance of standard turbine

NASA Technical Reports Server (NTRS)

Rohlik, Harold E; Wintucky, William T; Scibbe, Herbert W

1957-01-01

Detailed design information including overall performance parameters, velocity diagrams, and blade surface velocities is presented. Experimental performance includes maps based on rating as well as total-pressure ratios showing the effect of exit whirl. Also included are results of surveys at the stator exit and downstream of the rotor at design speed and specific work. This information will be used as a standard for comparison with subsequent secondary-flow work.

Design and validity of a clinic-based case-control study on the molecular epidemiology of lymphoma

PubMed Central

Cerhan, James R; Fredericksen, Zachary S; Wang, Alice H; Habermann, Thomas M; Kay, Neil E; Macon, William R; Cunningham, Julie M; Shanafelt, Tait D; Ansell, Stephen M; Call, Timothy G; Witzig, Thomas E; Slager, Susan L; Liebow, Mark

2011-01-01

We present the design features and implementation of a clinic-based case-control study on the molecular epidemiology of lymphoma conducted at the Mayo Clinic (Rochester, Minnesota, USA), and then assess the internal and external validity of the study. Cases were newly diagnosed lymphoma patients from Minnesota, Iowa and Wisconsin seen at Mayo and controls were patients from the same region without lymphoma who had a pre-scheduled general medical examination, frequency matched on age, sex and residence. Overall response rates were 67% for cases and 70% for controls; response rates were lower for cases and controls over age 70 years, cases with more aggressive disease, and controls from the local area, although absolute differences were modest. Cases and controls were well-balanced on age, sex, and residence characteristics. Demographic and disease characteristics of NHL cases were similar to population-based cancer registry data. Control distributions were similar to population-based data on lifestyle factors and minor allele frequencies of over 500 SNPs, although smoking rates were slightly lower. Associations with NHL in the Mayo study for smoking, alcohol use, family history of lymphoma, autoimmune disease, asthma, eczema, body mass index, and single nucleotide polymorphisms in TNF (rs1800629), LTA (rs909253), and IL10 (rs1800896) were at a magnitude consistent with estimates from pooled studies in InterLymph, with history of any allergy the only directly discordant result in the Mayo study. These data suggest that this study should have strong internal and external validity. This framework may be useful to others who are designing a similar study. PMID:21686124

INTENSIVE WATERSHED STUDY: THE PATUXENT RIVER BASIN

EPA Science Inventory

This study was one of five intensive watershed studies designed by the Chesapeake Bay Program's Eutrophication Work Group to provide detailed nonpoint source loading rates and ambient water quality data within the Chesapeake Bay drainage area. The study was conducted within the P...

Field demonstration of the combined effects of absorption and evapotranspiration on septic system drainfield capacity.

PubMed

Rainwater, Ken; Jackson, Andrew; Ingram, Wesley; Lee, Chang Yong; Thompson, David; Mollhagen, Tony; Ramsey, Heyward; Urban, Lloyd

2005-01-01

Drainfields for disposal of septic tank effluents are typically designed by considering the loss of water by either upward evapotranspiration into the atmosphere or lateral and downward absorption into the adjacent soil. While this approach is appropriate for evapotranspiration systems, absorption systems allow water loss by both mechanisms. It was proposed that, in areas where high evapotranspiration rates coincide with permeable soils, drainfield sizes could be substantially reduced by accounting for both mechanisms. A two-year field demonstration was conducted to determine appropriate design criteria for areas typical of the Texas High Plains. The study consisted of evaluating the long-term acceptance rates for three different drainfield configurations: evapotranspiration only, absorption only, and combined conditions. A second field demonstration repeated the experiments for additional observation of the combined evapotranspiration and absorption and achieved similar results as the first study. The field tests indicated that the current design loading criteria may be increased by at least a factor of two for the Texas High Plains region and other Texas areas with similar soil composition and evapotranspiration rates, while still retaining a factor of safety of two.

Microstructural analysis of hot press formed 22MnB5 steel

NASA Astrophysics Data System (ADS)

Aziz, Nuraini; Aqida, Syarifah Nur; Ismail, Izwan

2017-10-01

This paper presents a microstructural study on hot press formed 22MnB5 steel for enhanced mechanical properties. Hot press forming process consists of simultaneous forming and quenching of heated blank. The 22MnB5 steel was processed at three different parameter settings: quenching time, water temperature and water flow rate. 22MnB5 was processed using 33 full factorial design of experiment (DOE). The full factorial DOE was designed using three factors of quenching time, water temperature and water flow rate at three levels. The factors level were quenching time range of 5 - 11 s, water temperature; 5 - 27°C and water flow rate; 20 - 40 L/min. The as-received and hot press forming processed steel was characterised for metallographic study and martensitic structure area percentage using JEOL Field Emission Scanning Electron Microscopic (FESEM). From the experimental finding, the hot press formed 22MnB5 steel consisted of 50 to 84% martensitic structure area. The minimum quenching time of 8 seconds was required to obtain formed sample with high percentage of martensite. These findings contribute to initial design of processing parameters in hot press forming of 22MnB5 steel blanks for automotive component.

Statins and Risk of Lower Limb Revision Surgery: The Influence of Differences in Study Design Using Electronic Health Records From the United Kingdom and Denmark

PubMed Central

Lalmohamed, Arief; van Staa, Tjeerd P.; Vestergaard, Peter; Leufkens, Hubertus G. M.; de Boer, Anthonius; Emans, Pieter; Cooper, Cyrus; de Vries, Frank

2016-01-01

Abstract Previous observational studies on statins have shown variable results based on the methodology used. Our objective was to study the association between statins and orthopedic implant failure and to explore the influence of methodological differences in study design. Our study base consisted of patients with a primary total joint replacement in Denmark and the United Kingdom (n = 189,286; 1987–2012). We used 4 study designs: 1) case-control (each patient with revision surgery matched to 4 controls), 2) time-dependent cohort (postoperative statin use as a time-varying exposure variable), 3) immortal time cohort (misclassifying the time postoperatively before statin use), and 4) time-exclusion cohort (excluding the time postoperatively before statin use). Cox proportional hazards models and logistic regression were used to estimate incidence rate ratios. In the time-dependent cohort design, statin use was associated with a decreased risk of revision surgery (adjusted incidence rate ratio (IRR) = 0.90, 95% confidence interval (CI): 0.85, 0.96), which was similar to our case-control results (IRR = 0.87, 95% CI: 0.81, 0.93). In contrast, both time-fixed cohort designs yielded substantially lower risk estimates (IRR = 0.36 (95% CI: 0.34, 0.38) and IRR = 0.65 (95% CI: 0.63, 0.68), respectively). We discourage the use of time-fixed cohort studies, which may falsely suggest protective effects. The simple choice of how to classify exposure can substantially change results from biologically plausible to implausible. PMID:27317693

Characterization of multiport solid state imagers at megahertz data rates

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

Yates, G.J.; Pena, C.R.; Turko, B.T.

1994-08-01

Test results obtained from two recently developed multiport Charge-Coupled Devices (CCDs) operated at pixel rates in the 10-to-100 MHz range will be presented . The CCDs were evaluated in Los Alamos National Laboratory`s High Speed Solid State Imager Test Station (HSTS) which features PC-based programmable clock waveform generation (Tektronix DAS 9200) and synchronously clocked Digital Sampling Oscilloscopes (DSOs) (LeCroy 9424/9314 series) for CCD pixel data acquisition, analysis and storage. The HSTS also provided special designed optical pinhole array test patterns in the 5-to-50 micron diameter range for use with Xenon Strobe and pulsed laser light sources to simultaneously provide multiplemore » single-pixel illumination patterns to study CCD point-spread-function (PSF) and pixel smear characteristics. The two CCDs tested, EEV model CCD-13 and EG&G Reticon model HSO512J, are both 512 {times} 512 pixel arrays with eight (8) and sixteen (16) video output ports respectively. Both devices are generically Frame Transfer CCDs (FT CCDs) designed for parallel bi-directional vertical readout to augment their multiport design for increased pixel rates over common single port serial readout architecture. Although both CCDs were tested similarly, differences in their designs precluded normalization or any direct comparisons of test results. Rate dependent parameters investigated include S/N, PSF, and MTF. The performance observed for the two imagers at various pixel rates from selected typical output ports is discussed.« less

Design and Verification of a Digital Controller for a 2-Piece Hemispherical Resonator Gyroscope

PubMed Central

Lee, Jungshin; Yun, Sung Wook; Rhim, Jaewook

2016-01-01

A Hemispherical Resonator Gyro (HRG) is the Coriolis Vibratory Gyro (CVG) that measures rotation angle or angular velocity using Coriolis force acting the vibrating mass. A HRG can be used as a rate gyro or integrating gyro without structural modification by simply changing the control scheme. In this paper, differential control algorithms are designed for a 2-piece HRG. To design a precision controller, the electromechanical modelling and signal processing must be pre-performed accurately. Therefore, the equations of motion for the HRG resonator with switched harmonic excitations are derived with the Duhamel Integral method. Electromechanical modeling of the resonator, electric module and charge amplifier is performed by considering the mode shape of a thin hemispherical shell. Further, signal processing and control algorithms are designed. The multi-flexing scheme of sensing, driving cycles and x, y-axis switching cycles is appropriate for high precision and low maneuverability systems. The differential control scheme is easily capable of rejecting the common mode errors of x, y-axis signals and changing the rate integrating mode on basis of these studies. In the rate gyro mode the controller is composed of Phase-Locked Loop (PLL), amplitude, quadrature and rate control loop. All controllers are designed on basis of a digital PI controller. The signal processing and control algorithms are verified through Matlab/Simulink simulations. Finally, a FPGA and DSP board with these algorithms is verified through experiments. PMID:27104539

Comparison of the Heat Release Rate from the Mass Loss Calorimeter to the Cone Calorimeter for Wood-based Materials

Treesearch

Laura E. Hasburgh; Robert H. White; Mark A. Dietenberger; Charles R. Boardman

2015-01-01

There is a growing demand for material properties to be used as inputs in fi re behavior models designed to address building fire safety. This comparative study evaluates using the mass loss calorimeter as an alternative to the cone calorimeter for obtaining heat release rates of wood-based materials. For this study, a modified mass loss calorimeter utilized an...

Lithium-Ion Performance and Abuse Evaluation Using Lithium Technologies 9Ah cell

NASA Technical Reports Server (NTRS)

Hall, Albert Daniel; Jeevarajan, Judith A.

2006-01-01

Lithium-ion batteries in a pouch form offer high energy density and safety in their designs and more recently they are offering performance at higher rates. Lithium Technologies 9Ah high-power pouch cells were studied at different rates, thermal environments, under vacuum and several different conditions of abuse including overcharge, over-discharge and external short circuit. Results of this study will be presented.

A Study of the Gender-Specific Mortality Rates in Korea and Japan for the Formation of Health Promotion Policy

ERIC Educational Resources Information Center

Nam, Eun-Woo; Song, Yea-Li-A

2007-01-01

Objective: This study attempts to provide fundamental information to help with the development of health policy and health services by looking at the trends of the gender-specific mortality rates in Korea and Japan. Design: The death statistics of Korea and Japan over the 21-year period from 1983 to 2003 are analyzed. Setting: We used the death…

The Swedish Version of the Ritvo Autism and Asperger Diagnostic Scale: Revised (RAADS-R). A Validation Study of a Rating Scale for Adults

ERIC Educational Resources Information Center

Andersen, Lisa M. J.; Naswall, Katharina; Manouilenko, Irina; Nylander, Lena; Edgar, Johan; Ritvo, Riva Ariella; Ritvo, Edward; Bejerot, Susanne

2011-01-01

There is a paucity of diagnostic instruments for adults with autism spectrum disorder (ASD). This study evaluates the psychometric properties of the Swedish version of the Ritvo Autism and Asperger Diagnostic Scale-Revised (RAADS-R), an 80-item self-rating scale designed to assist clinicians diagnosing ASD in adults. It was administered to 75…

The Efficacy of a Brief Nature Sound Intervention on Muscle Tension, Pulse Rate, and Self-Reported Stress: Nature Contact Micro-Break in an Office or Waiting Room.

PubMed

Largo-Wight, Erin; O'Hara, Brian K; Chen, W William

2016-10-01

There is a growing recognition that environmental design impacts health and well-being. Nature contact is a design feature or exposure that is especially important in public health and healthcare. To date, there are limited findings on the impact of nature sounds. This experimental study was designed to examine the effect of nature sounds on physiological and psychological stress. Participants were randomized into one of three groups-silence (n = 9), nature sound (n = 17), and classical music (n = 14)-and listened to the assigned sound for 15 min in an office or waiting room-like environment. Pre- and postdata were collected including muscle tension (electromyogram), pulse rate, and self-reported stress. With the exception of pulse rate, there were no statistical differences in baseline or demographics among groups. A paired t-test by group showed a decrease in muscle tension, pulse rate, and self-reported stress in the nature group and no significant differences in the control or the classical music groups. The significant reduction in muscle tension occurred at least by 7 min of listening to the nature sound. This study highlights the potential benefit of even very brief (less than 7 min) exposure to nature sounds. Brief nature sound "booster breaks" are a promising area for future research with important practical implications. © The Author(s) 2016.

Comparative Packaging Study

NASA Technical Reports Server (NTRS)

Perchonok, Michele; Antonini, David

2008-01-01

This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

Technical Adequacy of the Disruptive Behavior Rating Scale-2nd Edition--Self-Report

ERIC Educational Resources Information Center

Erford, Bradley T.; Miller, Emily M.; Isbister, Katherine

2015-01-01

This study provides preliminary analysis of the Disruptive Behavior Rating Scale-2nd Edition--Self-Report, which was designed to screen individuals aged 10 years and older for anxiety and behavior symptoms. Score reliability and internal and external facets of validity were good for a screening-level test.

Power Analysis for Models of Change in Cluster Randomized Designs

ERIC Educational Resources Information Center

Li, Wei; Konstantopoulos, Spyros

2017-01-01

Field experiments in education frequently assign entire groups such as schools to treatment or control conditions. These experiments incorporate sometimes a longitudinal component where for example students are followed over time to assess differences in the average rate of linear change, or rate of acceleration. In this study, we provide methods…

Financial Condition and Tuition in Private Nonprofit Baccalaureate Higher Education

ERIC Educational Resources Information Center

Peruso, Dominick F., Jr.

2012-01-01

The rate of tuition inflation at U.S. colleges and universities is alarming and threatens both access and choice. Private nonprofit baccalaureate colleges often possess the highest tuition rates but routinely face financial challenges. This study was designed to better understand the relationship between tuition and financial condition for the…

Using Repeated Reading to Improve Reading Speed and Comprehension in Students with Visual Impairments

ERIC Educational Resources Information Center

Savaiano, Mackenzie E.; Hatton, Deborah D.

2013-01-01

Introduction: This study evaluated whether children with visual impairments who receive repeated reading instruction exhibit an increase in their oral reading rate and comprehension and a decrease in oral reading error rates. Methods: A single-subject, changing-criterion design replicated across three participants was used to demonstrate the…

The Effects of Televised Political Advertisements on Voter Perceptions about Candidates.

ERIC Educational Resources Information Center

Baskin, Otis Wayne

This study investigated whether candidate images could be designated as primarily either stimulus- or perceiver-determined and if a multiple regression model could be constructed to predict candidate image ratings from pre-stimulus perceptions of the candidate's party and post-stimulus ratings of the advertisement. One hundred twenty subjects were…

Adapting the Structural Family Systems Rating to Assess the Patterns of Interaction in Families of Dementia Caregivers

ERIC Educational Resources Information Center

Mitrani, Victoria B.; Feaster, Daniel J.; McCabe, Brian E.; Czaja, Sara J.; Szapocznik, Jose

2005-01-01

Purpose: This study adapted the Structural Family Systems Ratings (SFSR), an observational measure of family interactions, for dementia caregivers. This article presents the development of the SFSR-Dementia Caregiver adaptation (SFSR-DC) and examines relationships between specific family-interaction patterns and caregiver distress. Design and…

Evidence of Parent and Teacher Validity in Screening for Handicaps.

ERIC Educational Resources Information Center

Schaefer, Earl S.; Edgerton, Marianna

This study of handicapped and non-handicapped preschool and early elementary school children and their older normal siblings was designed to determine (1) the intercorrelation of parent and teacher ratings of the child's academic competence and social adjustment, and (2) the correlations of mother, father and teacher ratings with the child's…

Absolute and Relative Reliability of Percentage of Syllables Stuttered and Severity Rating Scales

ERIC Educational Resources Information Center

Karimi, Hamid; O'Brian, Sue; Onslow, Mark; Jones, Mark

2014-01-01

Purpose: Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide…

Demographic and psychological variables affecting test subject evaluations of ride quality

NASA Technical Reports Server (NTRS)

Duncan, N. C.; Conley, H. W.

1975-01-01

Ride-quality experiments similar in objectives, design, and procedure were conducted, one using the U.S. Air Force Total In-Flight Simulator and the other using the Langley Passenger Ride Quality Apparatus to provide the motion environments. Large samples (80 or more per experiment) of test subjects were recruited from the Tidewater Virginia area and asked to rate the comfort (on a 7-point scale) of random aircraft motion typical of that encountered during STOL flights. Test subject characteristics of age, sex, and previous flying history (number of previous airplane flights) were studied in a two by three by three factorial design. Correlations were computed between one dependent measure, the subject's mean comfort rating, and various demographic characteristics, attitudinal variables, and the scores on Spielberger's State-Trait Anxiety Inventory. An effect of sex was found in one of the studies. Males made higher (more uncomfortable) ratings of the ride than females. Age and number of previous flights were not significantly related to comfort ratings. No significant interactions between the variables of age, sex, or previous number of flights were observed.

Design and experimental study on desulphurization process of ship exhaust

NASA Astrophysics Data System (ADS)

Han, Mingyang; Hao, Shan; Zhou, Junbo; Gao, Liping

2018-02-01

This desulfurization process involves removing sulfur oxides with seawater or alkaline aqueous solutions and then treating the effluent by aeration and pH adjustment before discharging it into the ocean. In the desulfurization system, the spray tower is the key equipment and the venturi tubes are the pretreatment device. The two stages of plates are designed to fully absorb sulfur oxides in exhaust gases. The spiral nozzles atomize and evenly spray the desulfurizers into the tower. This study experimentally investigated the effectiveness of this desulfurization process and the factors influencing it under laboratory conditions, with a diesel engine exhaust used to represent ship exhaust. The experimental results show that this process can effectively absorb the SO2 in the exhaust. When the exhaust flow rate was 25 m3/h and the desulfurizer flow rate was 4 L/min, the sulfur removal efficiency (SRE) reached 99.7%. The flow rate, alkalinity, and temperature of seawater were found to have significant effects on the SRE. Adjusting seawater flow rate (SWR) and alkalinity within certain ranges can substantially improve the SRE.

Designing an Automated Assessment of Public Speaking Skills Using Multimodal Cues

ERIC Educational Resources Information Center

Chen, Lei; Feng, Gary; Leong, Chee Wee; Joe, Jilliam; Kitchen, Christopher; Lee, Chong Min

2016-01-01

Traditional assessments of public speaking skills rely on human scoring. We report an initial study on the development of an automated scoring model for public speaking performances using multimodal technologies. Task design, rubric development, and human rating were conducted according to standards in educational assessment. An initial corpus of…

Wood Preference of Reticulitermes virginicus (Blattodea: Rhinotermitidae) Using No-, Two-, and Four-Choice Designs and Seven Different Measures of Wood Consumption.

PubMed

Lee, T-Y; Forschler, B T

2016-04-01

Three hundred Reticulitermes virginicus (Banks) workers were exposed to three 1-cm3 wood blocks of either Quercus sp. (Red Oak), Populus sp. (Poplar), Pinus sp. (Pine), or Sequoia sp. (Redwood) placed into one of the three bioassay designs (no-, two-, and four-choice) for 21 d. Termite wood consumption was measured by wood weight loss, resistance class, and visual rating. Wood consumption rates were determined using four formulas in addition to two standardized visual rating scales (American Society for Testing and Materials [ASTM] and American Wood Protection Association [AWPA]) and a preference ranking obtained for each measure. The wood consumption formula, rating scale, and preference rankings were compared by bioassay design. The overall preference ranking of the four wood types as determined by the combination of all three designs was—1) Pine, 2) Red Oak, 3) Redwood, and 4) Poplar. Results indicate that bioassay design influenced both wood consumption and preference rankings. A no-choice design can determine aversion; a four-choice design the most preferred wood; and a two-choice design can illuminate the fine details of comparative preference. The different formulas employed for calculation of consumption rate influenced preference ranking in the no- and four-choice designs but not the two-choice design.

Design, Development and Analysis of Centrifugal Blower

NASA Astrophysics Data System (ADS)

Baloni, Beena Devendra; Channiwala, Salim Abbasbhai; Harsha, Sugnanam Naga Ramannath

2018-06-01

Centrifugal blowers are widely used turbomachines equipment in all kinds of modern and domestic life. Manufacturing of blowers seldom follow an optimum design solution for individual blower. Although centrifugal blowers are developed as highly efficient machines, design is still based on various empirical and semi empirical rules proposed by fan designers. There are different methodologies used to design the impeller and other components of blowers. The objective of present study is to study explicit design methodologies and tracing unified design to get better design point performance. This unified design methodology is based more on fundamental concepts and minimum assumptions. Parametric study is also carried out for the effect of design parameters on pressure ratio and their interdependency in the design. The code is developed based on a unified design using C programming. Numerical analysis is carried out to check the flow parameters inside the blower. Two blowers, one based on the present design and other on industrial design, are developed with a standard OEM blower manufacturing unit. A comparison of both designs is done based on experimental performance analysis as per IS standard. The results suggest better efficiency and more flow rate for the same pressure head in case of the present design compared with industrial one.

A new design approach to achieve a minimum impulse limit cycle in the presence of significant measurement uncertainties

NASA Technical Reports Server (NTRS)

Martin, M. W.; Kubiak, E. T.

1982-01-01

A new design was developed for the Space Shuttle Transition Phase Digital Autopilot to reduce the impact of large measurement uncertainties in the rate signal during attitude control. The signal source, which was dictated by early computer constraints, is characterized by large quantization, noise, bias, and transport lag which produce a measurement uncertainty larger than the minimum impulse rate change. To ensure convergence to a minimum impulse limit cycle, the design employed bias and transport lag compensation and a switching logic with hysteresis, rate deadzone, and 'walking' switching line. The design background, the rate measurement uncertainties, and the design solution are documented.

From Information Management to Information Visualization

PubMed Central

Karami, Mahtab

2016-01-01

Summary Objective The development and implementation of a dashboard of medical imaging department (MID) performance indicators. Method Several articles discussing performance measures of imaging departments were searched for this study. All the related measures were extracted. Then, a panel of imaging experts were asked to rate these measures with an open ended question to seek further potential indicators. A second round was performed to confirm the performance rating. The indicators and their ratings were then reviewed by an executive panel. Based on the final panel’s rating, a list of indicators to be used was developed. A team of information technology consultants were asked to determine a set of user interface requirements for the building of the dashboard. In the first round, based on the panel’s rating, a list of main features or requirements to be used was determined. Next, Qlikview was utilized to implement the dashboard to visualize a set of selected KPI metrics. Finally, an evaluation of the dashboard was performed. Results 92 MID indicators were identified. On top of this, 53 main user interface requirements to build of the prototype of dashboard were determined. Then, the project team successfully implemented a prototype of radiology management dashboards into study site. The visual display that was designed was rated highly by users. Conclusion To develop a dashboard, management of information is essential. It is recommended that a quality map be designed for the MID. It can be used to specify the sequence of activities, their related indicators and required data for calculating these indicators. To achieve both an effective dashboard and a comprehensive view of operations, it is necessary to design a data warehouse for gathering data from a variety of systems. Utilizing interoperability standards for exchanging data among different systems can be also effective in this regard. PMID:27437043

Characteristics of NIH- and industry-sponsored head and neck cancer clinical trials.

PubMed

Devaiah, Anand; Murchison, Charles

2016-09-01

Compare U.S. clinical trials sponsored by the National Institutes of Health (NIH) and industry, especially with regard to trial design, interventions studied, and results reporting rates. U.S. head and neck cancer clinical trials. We used information from ClinicalTrials.gov to compare NIH- and industry-sponsored head and neck cancer clinical trials, specifically analyzing differences in trial design and interventions studied. We examined publication rates and positive results rates using PubMed.gov. About 50% of NIH- and industry-sponsored clinical trials have their results reported in peer-reviewed literature. Industry-sponsored trials had higher rates of positive results than NIH-sponsored trials. NIH- and industry-sponsored clinical trials had similar trial designs, although industry-sponsored trials had significantly lower rates of randomization. Industry trials utilized radiation in 19% of trials and surgery in 2% of trials. NIH trials also had low utilization of both radiation and surgery (27% and 12% of trials, respectively). NIH- and industry-sponsored trials published their results in journals with comparable impact factors. There is significant underreporting of results in U.S. head and neck cancer clinical trials, whether sponsored by NIH or industry. Industry trials have significantly higher rates of positive results, although it is unclear what contributes to this. Both NIH- and industry-sponsored trials underutilize surgery and radiation as treatment modalities, despite the fact that these are standard-of-care therapies for head and neck cancer. We recommend that the NIH and industry report all results from clinical trials and use surgery and radiation as treatment arms in order to arrive at more balanced therapeutic recommendations. N/A. Laryngoscope, 126:E300-E303, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Tip Design of Hemodialysis Catheters Influences Thrombotic Events and Replacement Rate.

PubMed

Petridis, C; Nitschke, M; Lehne, W; Smith, E; Goltz, J P; Lehnert, H; Meier, M

2017-02-01

Central venous tunnelled hemodialysis catheters (CVTC) are used for initial vascular access in patients with renal failure. Tip design of the CVTC may play an important role in catheter function and complication rates, influencing adequate hemodialysis treatment of these patients. This prospective, observational cohort study compared the function and complication rates of two CVTCs in patients with end stage renal disease (ESRD) within a follow-up period of 24 months. The study included patients with ESRD who received either a CVTC with a split tip (ST) or a shotgun tip (SG). All patients underwent dialysis within 24 h of intervention. Blood flow was documented initially (Qb 0 ) and was followed up after 6 (Qb 6 ), 12 (Qb 12 ), and 24 (Qb 24 ) months. Analysis of blood flow and complication rates within the follow-up period was performed by questionnaires. In total, 185 patients were included, of whom 93 received a ST CVTC and 92 a SG CVTC. Baseline parameters did not differ significantly between groups. CVTC blood flow was not significantly different between the two devices. Thrombolytic therapy with Alteplase was used significantly more often in the ST group (29%) than in the SG group (16%) (p < 0.05). The CVTC replacement rate was significantly higher in the ST group (19.3%) compared with the SG group (8.7%) (p < 0.05). The tip design of CVTC (split or shotgun) appears to be irrelevant for long-term blood flow during dialysis treatment. However, patients may benefit from SG catheters over ST catheters where replacement rates and thrombolytic treatment are concerned. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Design of the Blood Pressure Goals in Dialysis pilot study.

PubMed

Gul, Ambreen; Miskulin, Dana; Gassman, Jennifer; Harford, Antonia; Horowitz, Bruce; Chen, Joline; Paine, Susan; Bedrick, Edward; Kusek, John W; Unruh, Mark; Zager, Philip

2014-02-01

Cardiovascular disease (CVD) is markedly increased among hemodialysis (HD) patients. Optimizing blood pressure (BP) among HD patients may present an important opportunity to reduce the disparity in CVD rates between HD patients and the general population. The optimal target predialysis systolic BP (SBP) among HD patients is unknown. Current international guidelines, calling for a predialysis SBP < 140 mm Hg, are based on the opinion and extrapolation from the general population. Existing randomized controlled trials (RCTs) were small and did not include prespecified BP targets. The authors described the design of the Blood Pressure in Dialysis (BID) Study, a pilot, multicenter RCT where HD patients are randomized to either a target-standardized predialysis SBP of 110 to 140 mm Hg or 155 to 165 mm Hg. This is the first study to randomize HD patients to 2 different SBP targets. Primary outcomes are feasibility and safety. Feasibility parameters include recruitment and retention rates, adherence with prescribed BP measurements and achievement and maintenance of selected BP targets. Safety parameters include rates of hypotension and other adverse and serious adverse events. The authors obtained preliminary data on changes in left ventricular mass, aortic pulse wave velocity, vascular access thromboses and health-related quality of life across study arms, which may be the secondary outcomes in the full-scale study. The data acquired in the pilot RCT will determine the feasibility and safety and inform the design of a full-scale trial, powered for hard outcomes, which may require 2000 participants.

Differential and directional effects of perfusion on electrical and thermal conductivities in liver.

PubMed

Podhajsky, Ronald J; Yi, Ming; Mahajan, Roop L

2009-01-01

Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.

Systematic Review and Meta-analysis: Placebo Rates in Induction and Maintenance Trials of Ulcerative Colitis

PubMed Central

Zou, Guangyong; Parker, Claire E.; Macdonald, John K.; Mosli, Mahmoud H.; Khanna, Reena; Shackelton, Lisa M.; Vandervoort, Margaret K.; AlAmeel, Turki; Al Beshir, Mohammad; AlMadi, Majid; Al-Taweel, Talal; Atkinson, Nathan S. S.; Biswas, Sujata; Chapman, Thomas P.; Dulai, Parambir S.; Glaire, Mark A.; Hoekman, Daniel; Koutsoumpas, Andreas; Minas, Elizabeth; Samaan, Mark A.; Travis, Simon; D’Haens, Geert; Levesque, Barrett G.; Sandborn, William J.; Feagan, Brian G.

2016-01-01

Background and Aims: Minimisation of the placebo responses in randomised controlled trials [RCTs] is essential for efficient evaluation of new interventions. Placebo rates have been high in ulcerative colitis [UC] clinical trials, and factors influencing this are poorly understood. We quantify placebo response and remission rates in UC RCTs and identify trial design factors influencing them. Methods: MEDLINE, EMBASE, and the Cochrane Library were searched from inception through April 2014 for placebo-controlled trials in adult patients with UC of a biological agent, corticosteroid, immunosuppressant, or aminosalicylate. Data were independently doubly extracted. Quality was assessed using the Cochrane risk of bias tool. Results: In all, 51 trials [48 induction and 10 maintenance phases] were identified. Placebo response and remission rates were pooled according to random-effects models, and mixed-effects meta-regression models were used to evaluate effects of study-level characteristics on these rates. Pooled estimates of placebo remission and response rates for induction trials were 10% (95% confidence interval [CI] 7-13%) and 33% [95% CI 29-37%], respectively. Corresponding values for maintenance trials were 19% [95% CI 11-30%] and 22% [95% CI 17-28%]. Trials enrolling patients with more active disease confirmed by endoscopy [endoscopy subscore ≥ 2] were associated with lower placebo rates. Conversely, placebo rates increased with increasing trial duration and number of study visits. Conclusions: Objective assessment of greater disease activity at trial entry by endoscopy lowered placebo rates, whereas increasing trial duration and more interactions with healthcare providers increased placebo rates. These findings have important implications for design and conduct of clinical trials. PMID:26746169

Radiation Protection Considerations

NASA Astrophysics Data System (ADS)

Adorisio, C.; Roesler, S.; Urscheler, C.; Vincke, H.

This chapter summarizes the legal Radiation Protection (RP) framework to be considered in the design of HiLumi LHC. It details design limits and constraints, dose objectives and explains how the As Low As Reasonably Achievable (ALARA) approach is formalized at CERN. Furthermore, features of the FLUKA Monte Carlo code are summarized that are of relevance for RP studies. Results of FLUKA simulations for residual dose rates during Long Shutdown 1 (LS1) are compared to measurements demonstrating good agreement and providing proof for the accuracy of FLUKA predictions for future shutdowns. Finally, an outlook for the residual dose rate evolution until LS3 is given.

Interventions to improve screening and appropriate referral of patients with cancer for psychosocial distress: systematic review

PubMed Central

Britton, Ben; Baker, Amanda L; Halpin, Sean A; Beck, Alison K; Carter, Gregory; Wratten, Chris; Bauer, Judith; Forbes, Erin; Booth, Debbie

2018-01-01

Objectives The primary aim of the review was to determine the effectiveness of strategies to improve clinician provision of psychosocial distress screening and referral of patients with cancer. Design Systematic review. Data sources Electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO and Cumulative Index to Nursing and Allied Health Literature (CINAHL)) were searched until July 2016. Inclusion criteria Population: adult patients with cancer and clinical staff members. Intervention: any strategy that aimed to improve the rate of routine screening and referral for detected distress of patients with cancer. Comparison: no intervention controls, ‘usual’ practice or alternative interventions. Outcome: (primary) any measure of provision of screening and/or referral for distress, (secondary) psychosocial distress, unintended adverse effects. Design: trials with or without a temporal comparison group, including randomised and non-randomised trials, and uncontrolled pre–post studies. Data extraction and analysis Two review authors independently extracted data. Heterogeneity across studies precluded quantitative assessment via meta-analysis and so a narrative synthesis of the results is presented. Results Five studies met the inclusion criteria. All studies were set in oncology clinics or departments and used multiple implementation strategies. Using the Grades of Recommendation, Assessment, Development and Evaluation, the overall rating of the certainty of the body of evidence reported in this review was assessed as very low. Three studies received a methodological quality rating of weak and two studies received a rating of moderate. Only one of the five studies reported a significant improvement in referrals. Conclusions The review identified five studies of predominantly poor quality examining the effectiveness of strategies to improve the routine implementation of distress screening and referral for patients with cancer. Future research using robust research designs, including randomised assignment, are needed to identify effective support strategies to maximise the potential for successful implementation of distress screening and referral for patients with cancer. PROSPERO registration number CRD42015017518. PMID:29306881

[Methodological design of the National Health and Nutrition Survey 2016].

PubMed

Romero-Martínez, Martín; Shamah-Levy, Teresa; Cuevas-Nasu, Lucía; Gómez-Humarán, Ignacio Méndez; Gaona-Pineda, Elsa Berenice; Gómez-Acosta, Luz María; Rivera-Dommarco, Juan Ángel; Hernández-Ávila, Mauricio

2017-01-01

Describe the design methodology of the halfway health and nutrition national survey (Ensanut-MC) 2016. The Ensanut-MC is a national probabilistic survey whose objective population are the inhabitants of private households in Mexico. The sample size was determined to make inferences on the urban and rural areas in four regions. Describes main design elements: target population, topics of study, sampling procedure, measurement procedure and logistics organization. A final sample of 9 479 completed household interviews, and a sample of 16 591 individual interviews. The response rate for households was 77.9%, and the response rate for individuals was 91.9%. The Ensanut-MC probabilistic design allows valid statistical inferences about interest parameters for Mexico´s public health and nutrition, specifically on overweight, obesity and diabetes mellitus. Updated information also supports the monitoring, updating and formulation of new policies and priority programs.

Green buildings need good ergonomics.

PubMed

Hedge, A; Dorsey, J A

2013-01-01

A retrospective post-occupancy evaluation survey of 44 occupants in two Leadership in Energy and Environmental Design (LEED) Platinum buildings on a US college campus is reported. The Internet survey covered a range of indoor environment and ergonomics issues. Results show that working in these buildings were a generally positive experience for their health, performance and satisfaction. However, in one building there were persistent issues of variability in air temperature, air freshness, air quality and noise that affected the perceived health and performance of the occupants. Although the buildings were energy-efficient and sustainable structures, ergonomics design issues were identified. Implications for the role of ergonomics in green buildings and in the US LEED rating system are discussed. This survey identified a number of ergonomics design issues present in the LEED Platinum energy-efficient and sustainable buildings that were studied. These results highlight the importance of integrating ergonomics design into green buildings as a component in the US LEED rating system.

Lead/acid battery development for heat engine/electric hybrid vehicles. Final report

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

Giner, J.; Taylor, A.H.; Goebel, F.

A program was undertaken to develop a lead/acid battery system for use in a hybrid heat engine/electric vehicle. The basic requirements are that the battery be capable of supplying high-rate power pulses and of accepting high-rate charge pulses, both of short duration. The feasibility of developing a bipolar lead/acid battery system which conforms to these specifications was investigated by using a modular approach to system design. In the preferred design, a vertical array of lead strips placed on either side of each substrate are connected with adjacent strips on the opposite side only over the top of the substrate tomore » provide electrical conduction through the substrate. The following topics are discussed concerning this system: study of electrochemical problem areas relevant to design of a high-power-density battery; corrosion of substrate materials; development and mechanical testing of structures; life testing; design and preliminary cost analysis.« less

Development of an advanced anaerobic digester design and a kinetic model for biogasification of water hyacinth/sludge blends

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

Srivastava, V.; Fannin, K.F.; Biljetina, R.

1986-07-01

The Institute of Gas Technology (IGT) conducted a comprehensive laboratory-scale research program to develop and optimize the anaerobic digestion process for producing methane from water hyacinth and sludge blends. This study focused on digester design and operating techniques, which gave improved methane yields and production rates over those observed using conventional digesters. The final digester concept and the operating experience was utilized to design and operate a large-scale experimentla test unit (ETU) at Walt Disney World, Florida. This paper describes the novel digester design, operating techniques, and the results obtained in the laboratory. The paper also discusses a kinetic modelmore » which predicts methane yield, methane production rate, and digester effluent solids as a function of retention time. This model was successfully utilized to predict the performance of the ETU. 15 refs., 6 figs., 6 tabs.« less

Investigation of Machine-ability of Inconel 800 in EDM with Coated Electrode

NASA Astrophysics Data System (ADS)

Karunakaran, K.; Chandrasekaran, M.

2017-03-01

The Inconel 800 is a high temperature application alloy which is classified as a nickel based super alloy. It has wide scope in aerospace engineering, gas Turbine etc. The machine-ability studies were found limited on this material. Hence This research focuses on machine-ability studies on EDM of Inconel 800 with Silver Coated Electrolyte Copper Electrode. The purpose of coating on electrode is to reduce tool wear. The factors pulse on Time, Pulse off Time and Peck Current were considered to observe the responses of surface roughness, material removal rate, tool wear rate. Taguchi Full Factorial Design is employed for Design the experiment. Some specific findings were reported and the percentage of contribution of each parameter was furnished

Global Search of a Three-dimensional Low Solidity Circular Cascade Diffuser for Centrifugal Blowers by Meta-model Assisted Optimization

NASA Astrophysics Data System (ADS)

Sakaguchi, Daisaku; Sakue, Daiki; Tun, Min Thaw

2018-04-01

A three-dimensional blade of a low solidity circular cascade diffuser in centrifugal blowers is designed by means of a multi-point optimization technique. The optimization aims at improving static pressure coefficient at a design point and at a small flow rate condition. Moreover, a clear definition of secondary flow expressed by positive radial velocity at hub side is taken into consideration in constraints. The number of design parameters for three-dimensional blade reaches to 10 in this study, such as a radial gap, a radial chord length and mean camber angle distribution of the LSD blade with five control points, control point between hub and shroud with two design freedom. Optimization results show clear Pareto front and selected optimum design shows good improvement of pressure rise in diffuser at small flow rate conditions. It is found that three-dimensional blade has advantage to stabilize the secondary flow effect with improving pressure recovery of the low solidity circular cascade diffuser.

New stimulation pattern design to improve P300-based matrix speller performance at high flash rate

NASA Astrophysics Data System (ADS)

Polprasert, Chantri; Kukieattikool, Pratana; Demeechai, Tanee; Ritcey, James A.; Siwamogsatham, Siwaruk

2013-06-01

Objective. We propose a new stimulation pattern design for the P300-based matrix speller aimed at increasing the minimum target-to-target interval (TTI). Approach. Inspired by the simplicity and strong performance of the conventional row-column (RC) stimulation, the proposed stimulation is obtained by modifying the RC stimulation through alternating row and column flashes which are selected based on the proposed design rules. The second flash of the double-flash components is then delayed for a number of flashing instants to increase the minimum TTI. The trade-off inherited in this approach is the reduced randomness within the stimulation pattern. Main results. We test the proposed stimulation pattern and compare its performance in terms of selection accuracy, raw and practical bit rates with the conventional RC flashing paradigm over several flash rates. By increasing the minimum TTI within the stimulation sequence, the proposed stimulation has more event-related potentials that can be identified compared to that of the conventional RC stimulations, as the flash rate increases. This leads to significant performance improvement in terms of the letter selection accuracy, the raw and practical bit rates over the conventional RC stimulation. Significance. These studies demonstrate that significant performance improvement over the RC stimulation is obtained without additional testing or training samples to compensate for low P300 amplitude at high flash rate. We show that our proposed stimulation is more robust to reduced signal strength due to the increased flash rate than the RC stimulation.

Polyethylene wear of mobile-bearing unicompartmental knee replacement at 20 years.

PubMed

Kendrick, B J L; Simpson, D J; Kaptein, B L; Valstar, E R; Gill, H S; Murray, D W; Price, A J

2011-04-01

The Oxford unicompartmental knee replacement (UKR) was designed to minimise wear utilising a fully-congruent, mobile, polyethylene bearing. Wear of polyethylene is a significant cause of revision surgery in UKR in the first decade, and the incidence increases in the second decade. Our study used model-based radiostereometric analysis to measure the combined wear of the upper and lower bearing surfaces in 13 medial-compartment Oxford UKRs at a mean of 20.9 years (17.2 to 25.9) post-operatively. The mean linear penetration of the polyethylene bearing was 1.04 mm (0.307 to 2.15), with a mean annual wear rate of 0.045 mm/year (0.016 to 0.099). The annual wear rate of the phase-2 bearings (mean 0.022 mm/year) was significantly less (p = 0.01) than that of phase-1 bearings (mean 0.07 mm/year). The linear wear rate of the Oxford UKR remains very low into the third decade. We believe that phase-2 bearings had lower wear rates than phase-1 implants because of the improved bearing design and surgical technique which decreased the incidence of impingement. We conclude that the design of the Oxford UKR gives low rates of wear in the long term.

[Design of Oxygen Saturation, Heart Rate, Respiration Rate Detection System Based on Smartphone of Android Operating System].

PubMed

Zhu, Mingshan; Zeng, Bixin

2015-03-01

In this paper, we designed an oxygen saturation, heart rate, respiration rate monitoring system based on smartphone of android operating system, physiological signal acquired by MSP430 microcontroller and transmitted by Bluetooth module.

Finite Element Analysis in the Estimation of Air-Gap Torque and Surface Temperature of Induction Machine

NASA Astrophysics Data System (ADS)

Mr., J. Ravi Kumar; Banakara, Basavaraja, Dr.

2017-08-01

This paper presents electromagnetic and thermal behavior of Induction Motor (IM) through the modeling and analysis by applying multiphysics coupled Finite Element Analysis (FEA). Therefore prediction of the magnetic flux, electromagnetic torque, stator and rotor losses and temperature distribution inside an operating electric motor are the most important issues during its design. Prediction and estimation of these parameters allows design engineers to decide capability of the machine for the proposed load, temperature rating and its application for which it is being designed ensuring normal motor operation at rated conditions. In this work, multiphysics coupled electromagnetic - thermal modeling and analysis of induction motor at rated and high frequency has carried out applying Arkkio’s torque method. COMSOL Multiphysics software is used for modeling and finite element analysis of IM. Transient electromagnetic torque, magnetic field distribution, speed-torque characteristics of IM were plotted and studied at different frequencies. This proposed work helps in the design and prediction of accurate performance of induction motor specific to various industrial drive applications. Results obtained are also validated with experimental analysis. The main purpose of this model is to use it as an integral part of the design aiming to system optimization of Variable Speed Drive (VSD) and its components using coupled simulations.

Recognition and Treatment Recommendations for Generalized Anxiety Disorder and Major Depressive Episode: A Cross-Sectional Study Among General Practitioners in Norway

PubMed Central

Olssøn, Ingrid; Mykletun, Arnstein; Dahl, Alv A.

2006-01-01

Objective: Undertreatment by general practitioners (GPs) of patients who have generalized anxiety disorder (GAD) and major depressive episodes (MDEs) is well known. Overtreatment by GPs of patients without these disorders has received little attention. The aim of this study was to estimate GPs' recommended overtreatment (recommendation of treatment to patients who, on the basis of diagnostic self-ratings, had neither GAD nor MDE) and undertreatment (not recommending treatment to patients who, on the basis of self-ratings, had GAD or MDE) and to describe patient variables associated with overtreatment. Method: In a cross-sectional design (during 3 consecutive days in September 2001), 136 Norwegian GPs evaluated 1332 patients. Diagnostic reference standards were patients' ratings of validated DSM-IV criteria–based questionnaires. GPs identified somatic diseases and mental disorders according to all accumulated information. For their diagnoses of MDE and GAD, the Clinical Global Impressions-Severity of Illness scale was used as a supplement, and GPs suggested treatment for these disorders. Results: The GPs recommended overtreatment in 11% (132/1245) of cases. The rates of under-treatment were 64% (18/28) and 49% (23/47) for GAD and MDE, respectively. For comorbid GAD and MDE the rate of undertreatment was 17% (2/12). Mental reason for patient's current visit and poor self-rated subjective health were strongly associated with overtreatment. Conclusion: Our preliminary study indicates that overtreatment by GPs of patients who, according to self-rating, do not have GAD or MDE could represent a problem. Criteria-based diagnostic descriptions might be of limited relevance for the practice of GPs, and the issue of overtreatment should be investigated further in studies with improved design. PMID:17245455

Design and analysis study of a spacecraft optical transceiver package

NASA Technical Reports Server (NTRS)

Lambert, S. G.

1985-01-01

A detailed system level design of an Optical Transceiver Package (OPTRANSPAC) for a deep space vehicle whose mission is outer planet exploration is developed. In addition to the terminal design, this study provides estimates of the dynamic environments to be encountered by the transceiver throughout its mission life. Optical communication link analysis, optical thin lens design, electronic functional design and mechanical layout and packaging are employed in the terminal design. Results of the study describe an Optical Transceiver Package capable of communicating to an Earth Orbiting Relay Station at a distance of 10 Astronomical Units (AU) and data rates up to 100 KBPS. The transceiver is also capable of receiving 1 KBPS of command data from the Earth Relay. The physical dimensions of the terminal are contained within a 3.5' x 1.5' x 2.0' envelope and the transceiver weight and power are estimated at 52.2 Kg (115 pounds) and 57 watts, respectively.

A comparative analysis between fixed bearing total knee arthroplasty (PFC Sigma) and rotating platform total knee arthroplasty (PFC-RP) with minimum 3-year follow-up.

PubMed

Jawed, Akram; Kumar, Vijay; Malhotra, R; Yadav, C S; Bhan, S

2012-06-01

Since the introduction of mobile bearing total knee designs nearly 30 years back, many studies have been done to evaluate its long-term result. Comparison with fixed bearing designs has been done in the past, but the studies were confounded by variables such as disease, surgeon, bone quality, pain tolerance, etc. We attempt to eliminate these variables in this study. A total of 50 patients who had bilateral arthritis of the knee with similar deformity and pre-operative range of motion on both sides agreed to have one knee replaced with mobile bearing total knee design (PFC-RP) and the other with a fixed bearing design (PFC Sigma) were prospectively evaluated. Comparative analysis of both the designs was done at a mean follow-up of 40 months, minimizing patient, surgeon and observer related bias. Clinical and radiographic outcome, survival and complication rates were compared. At a mean follow-up of 40 months (range 36-47 months), no benefit of mobile bearing (PFC-RP) over fixed bearing design (PFC Sigma) could be demonstrated with respect to Knee Society scores, pain scores, range of flexion, subject preference or patello-femoral complication rates. Radiographs showed no difference in prosthetic alignment. No patient required a revision surgery till last follow-up. Our study demonstrated no advantage of the mobile-bearing arthroplasty over fixed bearing arthroplasty with regard to clinical results at short-term follow-up. However, longer follow-up is necessary to confirm whether these results are sustained.

Does urban sprawl impact on self-rated health and psychological distress? A multilevel study from Sydney, Australia.

PubMed

Jalaludin, Bin B; Garden, Frances L

2011-09-01

Mental health can be influenced by a number of neighbourhood physical and social environmental characteristics. We aimed to determine whether urban sprawl (based on population density) in Sydney, Australia, is associated with self-rated health and psychological distress. We used a cross-sectional multilevel study design. Individual level data on self-rated health and psychological distress were obtained from the 2006 and 2007 NSW Population Health Survey. We did not find significant associations between urban sprawl and self-rated health and psychological distress after controlling for individual and area level covariates. However, positive neighbourhood factors were generally associated with better self-rated health and lower psychological distress but few of these associations were statistically significant.

Feasibility of using routinely collected inpatient data to monitor quality and inform choice: a case study using the UK inflammatory bowel disease audit

PubMed Central

Roberts, Stephen E; Williams, John G; Cohen, David R; Akbari, Ashley; Groves, Sam; Button, Lori A

2011-01-01

Objective To assess the utility and cost of using routinely collected inpatient data for large-scale audit. Design Comparison of audit data items collected nationally in a designed audit of inflammatory bowel disease (UK IBD audit) with routinely collected inpatient data; surveys of audit sites to compare costs. Setting National Health Service hospitals across England, Wales and Northern Ireland that participated in the UK IBD audit. Patients Patients in the UK IBD audit. Interventions None. Main outcome measures Percentage agreement between designed audit data items collected for the UK IBD audit and routine inpatient data items; costs of conducting the designed UK IBD audit and the routine data audit. Results There were very high matching rates between the designed audit data and routine data for a small subset of basic important information collected in the UK IBD audit, including mortality; major surgery; dates of admission, surgery, discharge and death; principal diagnoses; and sociodemographic patient characteristics. There were lower matching rates for other items, including source of admission, primary reason for admission, most comorbidities, colonoscopy and sigmoidoscopy. Routine data did not cover most detailed information collected in the UK IBD audit. Using routine data was much less costly than collecting designed audit data. Conclusion Although valuable for large population-based studies, and less costly than designed data, routine inpatient data are not suitable for the evaluation of individual patient care within a designed audit. PMID:28839601

Multiport backside-illuminated CCD imagers for high-frame-rate camera applications

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Sauer, Donald J.; Hseuh, Fu-Lung; Shallcross, Frank V.; Taylor, Gordon C.; Meray, Grazyna M.; Tower, John R.; Harrison, Lorna J.; Lawler, William B.

1994-05-01

Two multiport, second-generation CCD imager designs have been fabricated and successfully tested. They are a 16-port 512 X 512 array and a 32-port 1024 X 1024 array. Both designs are back illuminated, have on-chip CDS, lateral blooming control, and use a split vertical frame transfer architecture with full frame storage. The 512 X 512 device has been operated at rates over 800 frames per second. The 1024 X 1024 device has been operated at rates over 300 frames per second. The major changes incorporated in the second-generation design are, reduction in gate length in the output area to give improved high-clock-rate performance, modified on-chip CDS circuitry for reduced noise, and optimized implants to improve performance of blooming control at lower clock amplitude. This paper discusses the imager design improvements and presents measured performance results at high and moderate frame rates. The design and performance of three moderate frame rate cameras are discussed.

Aircraft digital control design methods

NASA Technical Reports Server (NTRS)

Powell, J. D.; Parsons, E.; Tashker, M. G.

1976-01-01

Variations in design methods for aircraft digital flight control are evaluated and compared. The methods fall into two categories; those where the design is done in the continuous domain (or s plane) and those where the design is done in the discrete domain (or z plane). Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the uncompensated s plane design method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

Design and rationale of the assessment of proper physiologic response with rate adaptive pacing driven by minute ventilation or accelerometer (APPROPRIATE) trial.

PubMed

Gilliam, F Roosevelt; Giudici, Michael; Benn, Andrew; Koplan, Bruce; Berg, Kellie Jean Chase; Kraus, Stacia Merkel; Stolen, Kira Q; Alvarez, Guy E; Hopper, Donald L; Wilkoff, Bruce L

2011-02-01

Rate-adaptive sensors are designed to restore a physiologic heart rate response to activity, in particular for patients that have chronotropic incompetence (CI). Limited data exist comparing two primary types of sensors; an accelerometer (XL) sensor which detects activity or motion and a minute ventilation (MV) sensor, which detects the product of respiration rate and tidal volume. The APPROPRIATE study will evaluate the MV sensor compared with the XL sensor for superiority in improving functional capacity (peak VO(2)) in pacemaker patients that have CI. This study is a double-blind, randomized, two-arm trial that will enroll approximately 1,000 pacemaker patients. Patients will complete a 6-min walk test at the 2-week visit to screen for potential CI. Those projected to have CI will advance to a 1-month visit. At the 1-month visit, final determination of CI will be done by completing a peak exercise treadmill test while the pacemaker is programmed to DDDR with the device sensors set to passive. Patients failing to meet the study criteria for CI will not continue further in the trial. Patients that demonstrate CI will be randomized to program their rate-adaptive sensors to either MV or XL in a 1:1 ratio. The rate-adaptive sensor will be optimized for each patient using a short walk to determine the appropriate response factor. At a 2-month visit, patients will complete a CPX test with the rate-adaptive sensors in their randomized setting.

Clinical Utilisation and Usefullness of the Rating Scale of Mixed States, ("Gt-Msrs"): a Multicenter Study.

PubMed

Tavormina, Giuseppe; Franza, Francesco; Stranieri, Giuseppe; Juli, Luigi; Juli, Maria Rosaria

2017-09-01

The rating scale "G.T. MSRS" has been designed to improve the clinical effectiveness of the clinician psychiatrists, by enabling them to make an early "general" diagnosis of mixed states. The knowledge of the clinical features of the mixed states and of the symptoms of the "mixity" of mood disorders is crucial: to mis-diagnose or mis-treat patients with these symptoms may increase the suicide risk and make worse the evolution of mood disorders going to the dysphoric state. This study is the second validation study of the "G.T. MSRS" rating scale, in order to demonstrate its usefullness.

Signal design study for shuttle/TDRSS Ku-band uplink

NASA Technical Reports Server (NTRS)

1976-01-01

The adequacy of the signal design approach chosen for the TDRSS/orbiter uplink was evaluated. Critical functions and/or components associated with the baseline design were identified, and design alternatives were developed for those areas considered high risk. A detailed set of RF and signal processing performance specifications for the orbiter hardware associated with the TDRSS/orbiter Ku band uplink was analyzed. Performances of a detailed design of the PN despreader, the PSK carrier synchronization loop, and the symbol synchronizer are identified. The performance of the downlink signal by means of computer simulation to obtain a realistic determination of bit error rate degradations was studied. The three channel PM downlink signal was detailed by means of analysis and computer simulation.

Associations Between the Macroeconomic Indicators and Suicide Rates in India: Two Ecological Studies.

PubMed

Rajkumar, Anto P; Senthilkumar, P; Gayathri, K; Shyamsundar, G; Jacob, K S

2015-01-01

While western studies have focused on the importance of psychiatric illnesses in the complex pathways leading to suicides, several Indian studies have highlighted the important contributions by economic, social, and cultural factors. Hence, we tested the hypothesis that annual national suicide rates and suicide rates of the different states in India were associated with macroeconomic indices. Data from the National crime records bureau, Ministry of finance, labour bureau, Government of India, population commission, and planning commission official portals, World Bank and the United Nations were accessed. We assessed the correlations of annual national and state-wise suicide rates with macroeconomic, health, and other indices using ecological study design for India, and for its different states and union territories. We documented statistically significant associations between the suicide rates and per capita gross domestic product, consumer price index, foreign exchange, trade balance, total health expenditure as well as literacy rates. As recent economic growth in India is associated with increasing suicide rates, macroeconomic policies emphasizing equitable distribution of resources may help curtailing the population suicide rates in India.

Associations Between the Macroeconomic Indicators and Suicide Rates in India: Two Ecological Studies

PubMed Central

Rajkumar, Anto P.; Senthilkumar, P.; Gayathri, K.; Shyamsundar, G.; Jacob, K. S.

2015-01-01

Background: While western studies have focused on the importance of psychiatric illnesses in the complex pathways leading to suicides, several Indian studies have highlighted the important contributions by economic, social, and cultural factors. Hence, we tested the hypothesis that annual national suicide rates and suicide rates of the different states in India were associated with macroeconomic indices. Materials and Methods: Data from the National crime records bureau, Ministry of finance, labour bureau, Government of India, population commission, and planning commission official portals, World Bank and the United Nations were accessed. We assessed the correlations of annual national and state-wise suicide rates with macroeconomic, health, and other indices using ecological study design for India, and for its different states and union territories. Results: We documented statistically significant associations between the suicide rates and per capita gross domestic product, consumer price index, foreign exchange, trade balance, total health expenditure as well as literacy rates. Conclusions: As recent economic growth in India is associated with increasing suicide rates, macroeconomic policies emphasizing equitable distribution of resources may help curtailing the population suicide rates in India. PMID:26664075

Forward Swept Compressor Testing

NASA Technical Reports Server (NTRS)

Miller, David P.

1997-01-01

A new forward-swept rotor designed by Allison Engine Company was tested in NASA Lewis Research Center's CE-18 facility. This testing was a follow-on project sponsored by NASA Lewis to study range enhancements in small turbomachinery. The test was conducted against a baseline rotor design that was also tested in CE-18. The design point for the rotor was a rotor pressure ratio of 2.69, a mass flow of 10.52 lbm/sec, and an adiabatic efficiency of 89.1 percent. Test data indicate that the rotor met the pressure ratio of 2.69 with a 10.77 lbm/sec flow rate, a 87.5-percent adiabatic efficiency, and a 19.5-percent stall margin. The baseline rotor achieved a pressure ratio of 2.69 at a 10.77 lbm/sec flow rate with a stall margin of only 9.2 percent and an adiabatic efficiency of 87.0 percent. The major differences are the significant stall margin increase and the substantially higher off-design peak efficiencies of the forward-swept rotor. The substantially higher performance over the baseline rotor design makes the new design a viable technology candidate for future products.

Advancement of proprotor technology. Task 1: Design study summary. [aerodynamic concept of minimum size tilt proprotor research aircraft

NASA Technical Reports Server (NTRS)

1969-01-01

A tilt-proprotor proof-of-concept aircraft design study has been conducted. The results are presented. The ojective of the contract is to advance the state of proprotor technology through design studies and full-scale wind-tunnel tests. The specific objective is to conduct preliminary design studies to define a minimum-size tilt-proprotor research aircraft that can perform proof-of-concept flight research. The aircraft that results from these studies is a twin-engine, high-wing aircraft with 25-foot, three-bladed tilt proprotors mounted on pylons at the wingtips. Each pylon houses a Pratt and Whitney PT6C-40 engine with a takeoff rating of 1150 horsepower. Empty weight is estimated at 6876 pounds. The normal gross weight is 9500 pounds, and the maximum gross weight is 12,400 pounds.

Annual survival estimation of migratory songbirds confounded by incomplete breeding site-fidelity: Study designs that may help

USGS Publications Warehouse

Marshall, M.R.; Diefenbach, D.R.; Wood, L.A.; Cooper, R.J.

2004-01-01

Many species of bird exhibit varying degrees of site-fidelity to the previous year's territory or breeding area, a phenomenon we refer to as incomplete breeding site-fidelity. If the territory they occupy is located beyond the bounds of the study area or search area (i.e., they have emigrated from the study area), the bird will go undetected and is therefore indistinguishable from dead individuals in capture-mark-recapture studies. Differential emigration rates confound inferences regarding differences in survival between sexes and among species if apparent survival rates are used as estimates of true survival. Moreover, the bias introduced by using apparent survival rates for true survival rates can have profound effects on the predictions of population persistence through time, source/sink dynamics, and other aspects of life-history theory. We investigated four study design and analysis approaches that result in apparent survival estimates that are closer to true survival estimates. Our motivation for this research stemmed from a multi-year capture-recapture study of Prothonotary Warblers (Protonotaria citrea) on multiple study plots within a larger landscape of suitable breeding habitat where substantial inter-annual movements of marked individuals among neighboring study plots was documented. We wished to quantify the effects of this type of movement on annual survival estimation. The first two study designs we investigated involved marking birds in a core area and resighting them in the core as well as an area surrounding the core. For the first of these two designs, we demonstrated that as the resighting area surrounding the core gets progressively larger, and more "emigrants" are resighted, apparent survival estimates begin to approximate true survival rates (bias < 0.01). However, given observed inter-annual movements of birds, it is likely to be logistically impractical to resight birds on sufficiently large surrounding areas to minimize bias. Therefore, as an alternative protocol, we analyzed the data with subsets of three progressively larger areas surrounding the core. The data subsets provided four estimates of apparent survival that asymptotically approached true survival. This study design and analytical approach is likely to be logistically feasible in field settings and yields estimates of true survival unbiased (bias < 0.03) by incomplete breeding site-fidelity over a range of inter-annual territory movement patterns. The third approach we investigated used a robust design data collection and analysis approach. This approach resulted in estimates of survival that were unbiased (bias < 0.02), but were very imprecise and likely would not yield reliable estimates in field situations. The fourth approach utilized a fixed study area size, but modeled detection probability as a function of bird proximity to the study plot boundary (e.g., those birds closest to the edge are more likely to emigrate). This approach also resulted in estimates of survival that were unbiased (bias < 0.02), but because the individual covariates were normalized, the average capture probability was 0.50, and thus did not provide an accurate estimate of the true capture probability. Our results show that the core-area with surrounding resight-only can provide estimates of survival that are not biased by the effects of incomplete breeding site-fidelity. ?? 2004 Museu de Cie??ncies Naturals.

The Design and Analysis of Salmonid Tagging Studies in the Columbia Basin : Volume II: Experiment Salmonid Survival with Combined PIT-CWT Tagging.

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

Newman, Ken

1997-06-01

Experiment designs to estimate the effect of transportation on survival and return rates of Columbia River system salmonids are discussed along with statistical modeling techniques. Besides transportation, river flow and dam spill are necessary components in the design and analysis otherwise questions as to the effects of reservoir drawdowns and increased dam spill may never be satisfactorily answered. Four criteria for comparing different experiment designs are: (1) feasibility, (2) clarity of results, (3) scope of inference, and (4) time to learn. In this report, alternative designs for conducting experimental manipulations of smolt tagging studies to study effects of river operationsmore » such as flow levels, spill fractions, and transporting outmigrating salmonids around dams in the Columbia River system are presented. The principles of study design discussed in this report have broad implications for the many studies proposed to investigate both smolt and adult survival relationships. The concepts are illustrated for the case of the design and analysis of smolt transportation experiments. The merits of proposed transportation studies should be measured relative to these principles of proper statistical design and analysis.« less

Parents' evaluation of media ratings a decade after the television ratings were introduced.

PubMed

Gentile, Douglas A; Maier, Julia A; Hasson, Mary Rice; Lopez de Bonetti, Beatriz

2011-07-01

The 3 national studies reported here were designed to find out how satisfied parents are with media rating systems, how regularly they use them, and what types of information they ideally would like to have. Parents (n=745, study 1; n=768, study 2; n=769, study 3) were surveyed nationally by independent research firms. Studies 1 and 2 were conducted by Harris Interactive, and study 3 was conducted by Research Now. All of them were cross-sectional national surveys. Parents desire ratings for many types of media, but they do not think the existing ratings accurately provide the information they want. They would prefer ratings to provide detailed content information. In general, parents tend to agree on the types and descriptors of content about which they would like to know. They do not, however, agree on the ages for which different content aspects are appropriate. Parents would support the creation of a universal rating system that could be applied to multiple types of media. Ratings can be effective only if they are useful for parents. This set of studies reveals that improvements in media ratings are needed to make them valuable for parents. Copyright © 2011 by the American Academy of Pediatrics.

Normative data for idiomatic expressions.

PubMed

Nordmann, Emily; Jambazova, Antonia A

2017-02-01

Idiomatic expressions such as kick the bucket or go down a storm can differ on a number of internal features, such as familiarity, meaning, literality, and decomposability, and these types of features have been the focus of a number of normative studies. In this article, we provide normative data for a set of Bulgarian idioms and their English translations, and by doing so replicate in a Slavic language the relationships between the ratings previously found in Romance and Germanic languages. Additionally, we compared whether collecting these types of ratings in between-subjects or within-subjects designs affects the data and the conclusions drawn, and found no evidence that design type affects the final outcome. Finally, we present the results of a meta-analysis that summarizes the relationships found across the literature. As in many previous individual studies, we found that familiarity correlates with a number of other features; however, such studies have shown conflicting results concerning literality and decomposability ratings. The meta-analysis revealed reliable relationships of decomposability with a number of other measures, such as familiarity, meaning, and predictability. Conversely, literality was shown to have little to no relationship with any of the other subjective ratings. The implications for these relationships in the context of the wider experimental literature are discussed, with a particular focus on the importance of attaining familiarity ratings for each sample of participants in experimental work.

Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

PubMed

Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

2016-03-01

To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is <90 beats/min; however, these values significantly increase in the St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves. © IMechE 2016.

Optimal design of active spreading systems to remediate sorbing groundwater contaminants in situ.

PubMed

Piscopo, Amy N; Neupauer, Roseanna M; Kasprzyk, Joseph R

2016-07-01

The effectiveness of in situ remediation to treat contaminated aquifers is limited by the degree of contact between the injected treatment chemical and the groundwater contaminant. In this study, candidate designs that actively spread the treatment chemical into the contaminant are generated using a multi-objective evolutionary algorithm. Design parameters pertaining to the amount of treatment chemical and the duration and rate of its injection are optimized according to objectives established for the remediation - maximizing contaminant degradation while minimizing energy and material requirements. Because groundwater contaminants have different reaction and sorption properties that influence their ability to be degraded with in situ remediation, optimization was conducted for six different combinations of reaction rate coefficients and sorption rates constants to represent remediation of the common groundwater contaminants, trichloroethene, tetrachloroethene, and toluene, using the treatment chemical, permanganate. Results indicate that active spreading for contaminants with low reaction rate coefficients should be conducted by using greater amounts of treatment chemical mass and longer injection durations relative to contaminants with high reaction rate coefficients. For contaminants with slow sorption or contaminants in heterogeneous aquifers, two different design strategies are acceptable - one that injects high concentrations of treatment chemical mass over a short duration or one that injects lower concentrations of treatment chemical mass over a long duration. Thus, decision-makers can select a strategy according to their preference for material or energy use. Finally, for scenarios with high ambient groundwater velocities, the injection rate used for active spreading should be high enough for the groundwater divide to encompass the entire contaminant plume. Copyright © 2016 Elsevier B.V. All rights reserved.

What Works Clearinghouse Quick Review: "Meeting the Challenge of Combating Chronic Absenteeism: Impact of the NYC Mayor's Interagency Task Force on Chronic Absenteeism and School Attendance and Its Implications for Other Cities"

ERIC Educational Resources Information Center

What Works Clearinghouse, 2013

2013-01-01

This study examined the effectiveness of an intervention designed to reduce rates of chronic student absenteeism in New York City public schools. The study authors reported that schools participating in the intervention experienced greater reductions in rates of student chronic absenteeism than the comparison schools. Students who attended the…

Kinetic Study of Methyl Acetate Oxidation in a Pt/Al2O3 Fixed-Bed Reactor

NASA Technical Reports Server (NTRS)

Hoy, Michael; Li, K. Y.; Li, Jeffrey S.; Chen, S. M.; Yaws, C. L.; Chu, H. W.; Simon, W. E.

1994-01-01

To support technology development for future long-term missions, a metabolic simulator will be used in a closed chamber to test the functions of a Controlled Ecological Life Support System (CELSS). Methyl acetate (MA) was selected as the fuel because its metabolic respiratory quotient is near that of humans. A kinetic study of the catalytic oxidation of MA over Pt/Al203 was then conducted to support the design and operation of the simulator. Kinetic data were obtained as a conversion percentage of MA versus retention time. The reaction was studied at one atmosphere and temperatures from 220 to 340 deg. C. The inlet MA concentration was varied from 100 to 2000 ppm with retention times from 0.01 to 10 sec. A first-order rate law and a Langmuir-Hinshelwood rate equation were tested by nonlinear regression of the kinetic data to estimate rate constants in the rate law. Regression results of the L-H equation explain the kinetic data better than the results of the first-order rate law. A Taguchi experimental design was used to study the effects of temperature, retention time, and concentrations of MA, CO2, and O2 on the conversion of MA. Results indicate that temperature has greatest effect, followed by retention time, and finally MA concentration. It was further determined that the effects of CO2 and O2 concentrations, and the cross effects, are negligible.

Development and optimization of SPE-HPLC-UV/ELSD for simultaneous determination of nine bioactive components in Shenqi Fuzheng Injection based on Quality by Design principles.

PubMed

Wang, Lu; Qu, Haibin

2016-03-01

A method combining solid phase extraction, high performance liquid chromatography, and ultraviolet/evaporative light scattering detection (SPE-HPLC-UV/ELSD) was developed according to Quality by Design (QbD) principles and used to assay nine bioactive compounds within a botanical drug, Shenqi Fuzheng Injection. Risk assessment and a Plackett-Burman design were utilized to evaluate the impact of 11 factors on the resolutions and signal-to-noise of chromatographic peaks. Multiple regression and Pareto ranking analysis indicated that the sorbent mass, sample volume, flow rate, column temperature, evaporator temperature, and gas flow rate were statistically significant (p < 0.05) in this procedure. Furthermore, a Box-Behnken design combined with response surface analysis was employed to study the relationships between the quality of SPE-HPLC-UV/ELSD analysis and four significant factors, i.e., flow rate, column temperature, evaporator temperature, and gas flow rate. An analytical design space of SPE-HPLC-UV/ELSD was then constructed by calculated Monte Carlo probability. In the presented approach, the operating parameters of sample preparation, chromatographic separation, and compound detection were investigated simultaneously. Eight terms of method validation, i.e., system-suitability tests, method robustness/ruggedness, sensitivity, precision, repeatability, linearity, accuracy, and stability, were accomplished at a selected working point. These results revealed that the QbD principles were suitable in the development of analytical procedures for samples in complex matrices. Meanwhile, the analytical quality and method robustness were validated by the analytical design space. The presented strategy provides a tutorial on the development of a robust QbD-compliant quantitative method for samples in complex matrices.

Development of a 300 Amp-hr high rate lithium thionyl chloride cell

NASA Technical Reports Server (NTRS)

Boyle, Gerard H.

1991-01-01

The development of a high-rate lithium thionyl chloride cylindrical cell with parallel plate electrodes is discussed. The development was divided into three phases: phase 1, a 150 Amp/hour low rate (1 mA/sq cm) design; phase 2, a 25 Amp/hour high rate (5 mA/sq cm) design; and phase 3, a 300 Amp/hour high rate (5 mA/sq cm) design. The basic design is the same for all three cells. The electrodes are perpendicular to the axis of the cylinder. Multiple electrodes are bussed up the side of the cylinder, 180 deg apart allowing excellent anode and cathode utilization. It is a lithium limited design with excess electrolyte. The cathode is Shawinigan or Gulf Acetylene black with no catalyst. The electrolyte is 1.8 Molar lithium tetrachloroaluminate (LiAlCl4) in thionyl chloride. All cell cases are 304L Stainless Steel with a BS&B burst disc.

Early Childhood Longitudinal Study, Birth Cohort (ECLS-B): Methodology Report for the 9-Month Data Collection (2001-02). Volume 2: Sampling. NCES 2005-147

ERIC Educational Resources Information Center

Bethel, James; Green, James L.; Nord, Christine; Kalton, Graham; West, Jerry

2005-01-01

This report is Volume 2 of the methodology report that provides information about the development, design, and conduct of the 9-month data collection of the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B). This volume begins with a brief overview of the ECLS-B, but focuses on the sample design, calculation of response rates, development…

Surf-zone Underwater Robotic Demonstration Platform

DTIC Science & Technology

2014-01-01

dynamically advantageous shape for a robotic system. To address locomotive factors ARA completed a research and technical study based on an Archimedes ...effective hull shape. To study mobility and traction a propulsion system based on an Archimedes screw drive was used. A drive design based on an... Archimedes screw was chosen because of its ability to operate in various mediums with varying flow rates. A test bed was designed and assembled in order to

Performance Ratings: Designs for Evaluating Their Validity and Accuracy.

DTIC Science & Technology

1986-07-01

ratees with substantial validity and with little bias due to the ethod for rating. Convergent validity and discriminant validity account for approximately...The expanded research design suggests that purpose for the ratings has little influence on the multitrait-multimethod properties of the ratings...Convergent and discriminant validity again account for substantial differences in the ratings of performance. Little method bias is present; both methods of

Collector design for measuring high intensity time variant sprinkler application rates

USDA-ARS?s Scientific Manuscript database

Peak water application rate in relation to soil water infiltration rate and soil surface storage capacity is important in the design of center pivot sprinkler irrigation systems for efficient irrigation and soil erosion control. Measurement of application rates of center pivot irrigation systems ha...

Precision is essential for efficient catalysis in an evolved Kemp eliminase.

PubMed

Blomberg, Rebecca; Kries, Hajo; Pinkas, Daniel M; Mittl, Peer R E; Grütter, Markus G; Privett, Heidi K; Mayo, Stephen L; Hilvert, Donald

2013-11-21

Linus Pauling established the conceptual framework for understanding and mimicking enzymes more than six decades ago. The notion that enzymes selectively stabilize the rate-limiting transition state of the catalysed reaction relative to the bound ground state reduces the problem of design to one of molecular recognition. Nevertheless, past attempts to capitalize on this idea, for example by using transition state analogues to elicit antibodies with catalytic activities, have generally failed to deliver true enzymatic rates. The advent of computational design approaches, combined with directed evolution, has provided an opportunity to revisit this problem. Starting from a computationally designed catalyst for the Kemp elimination--a well-studied model system for proton transfer from carbon--we show that an artificial enzyme can be evolved that accelerates an elementary chemical reaction 6 × 10(8)-fold, approaching the exceptional efficiency of highly optimized natural enzymes such as triosephosphate isomerase. A 1.09 Å resolution crystal structure of the evolved enzyme indicates that familiar catalytic strategies such as shape complementarity and precisely placed catalytic groups can be successfully harnessed to afford such high rate accelerations, making us optimistic about the prospects of designing more sophisticated catalysts.

Investigation on the Core Bypass Flow in a Very High Temperature Reactor

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

Hassan, Yassin

2013-10-22

Uncertainties associated with the core bypass flow are some of the key issues that directly influence the coolant mass flow distribution and magnitude, and thus the operational core temperature profiles, in the very high-temperature reactor (VHTR). Designers will attempt to configure the core geometry so the core cooling flow rate magnitude and distribution conform to the design values. The objective of this project is to study the bypass flow both experimentally and computationally. Researchers will develop experimental data using state-of-the-art particle image velocimetry in a small test facility. The team will attempt to obtain full field temperature distribution using racksmore » of thermocouples. The experimental data are intended to benchmark computational fluid dynamics (CFD) codes by providing detailed information. These experimental data are urgently needed for validation of the CFD codes. The following are the project tasks: • Construct a small-scale bench-top experiment to resemble the bypass flow between the graphite blocks, varying parameters to address their impact on bypass flow. Wall roughness of the graphite block walls, spacing between the blocks, and temperature of the blocks are some of the parameters to be tested. • Perform CFD to evaluate pre- and post-test calculations and turbulence models, including sensitivity studies to achieve high accuracy. • Develop the state-of-the art large eddy simulation (LES) using appropriate subgrid modeling. • Develop models to be used in systems thermal hydraulics codes to account and estimate the bypass flows. These computer programs include, among others, RELAP3D, MELCOR, GAMMA, and GAS-NET. Actual core bypass flow rate may vary considerably from the design value. Although the uncertainty of the bypass flow rate is not known, some sources have stated that the bypass flow rates in the Fort St. Vrain reactor were between 8 and 25 percent of the total reactor mass flow rate. If bypass flow rates are on the high side, the quantity of cooling flow through the core may be considerably less than the nominal design value, causing some regions of the core to operate at temperatures in excess of the design values. These effects are postulated to lead to localized hot regions in the core that must be considered when evaluating the VHTR operational and accident scenarios.« less

Enhanced styrene recovery from waste polystyrene pyrolysis using response surface methodology coupled with Box-Behnken design.

PubMed

Mo, Yu; Zhao, Lei; Wang, Zhonghui; Chen, Chia-Lung; Tan, Giin-Yu Amy; Wang, Jing-Yuan

2014-04-01

A work applied response surface methodology coupled with Box-Behnken design (RSM-BBD) has been developed to enhance styrene recovery from waste polystyrene (WPS) through pyrolysis. The relationship between styrene yield and three selected operating parameters (i.e., temperature, heating rate, and carrier gas flow rate) was investigated. A second order polynomial equation was successfully built to describe the process and predict styrene yield under the study conditions. The factors identified as statistically significant to styrene production were: temperature, with a quadratic effect; heating rate, with a linear effect; carrier gas flow rate, with a quadratic effect; interaction between temperature and carrier gas flow rate; and interaction between heating rate and carrier gas flow rate. The optimum conditions for the current system were determined to be at a temperature range of 470-505°C, a heating rate of 40°C/min, and a carrier gas flow rate range of 115-140mL/min. Under such conditions, 64.52% WPS was recovered as styrene, which was 12% more than the highest reported yield for reactors of similar size. It is concluded that RSM-BBD is an effective approach for yield optimization of styrene recovery from WPS pyrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Temperature-dependent electrochemical heat generation in a commercial lithium-ion battery

NASA Astrophysics Data System (ADS)

Bandhauer, Todd M.; Garimella, Srinivas; Fuller, Thomas F.

2014-02-01

Lithium-ion batteries suffer from inherent thermal limitations (i.e., capacity fade and thermal runaway); thus, it is critical to understand heat generation experienced in the batteries under normal operation. In the current study, reversible and irreversible electrochemical heat generation rates were measured experimentally on a small commercially available C/LiFePO4 lithium-ion battery designed for high-rate applications. The battery was tested over a wide range of temperatures (10-60 °C) and discharge and charge rates (∼C/4-5C) to elucidate their effects. Two samples were tested in a specially designed wind tunnel to maintain constant battery surface temperature within a maximum variation of ±0.88 °C. A data normalization technique was employed to account for the observed capacity fade, which was largest at the highest rates. The heat rate was shown to increase with both increasing rate and decreasing temperature, and the reversible heat rate was shown to be significant even at the highest rate and temperature (7.4% at 5C and 55 °C). Results from cycling the battery using a dynamic power profile also showed that constant-current data predict the dynamic performance data well. In addition, the reversible heat rate in the dynamic simulation was shown to be significant, especially for charge-depleting HEV applications.

The case-control design in veterinary sciences: A survey.

PubMed

Cullen, Jonah N; Sargeant, Jan M; Makielski, Kelly M; O'Connor, Annette M

2016-11-01

The case-control study design is deceptively simple. However, many design considerations influence the estimated effect measure. An investigation of case-control studies in the human health literature suggested that some of these considerations are not described in reports of case-control studies. Our hypothesis was that the majority of veterinary studies labeled as case-controls would be incident density designs, and many would not interpret the effect measure obtained from those studies as the rate ratio rather than the odds ratio. Reference databases were searched for author-designated case-control studies. A survey of 100 randomly selected studies was conducted to examine the different design options described and estimated effect measures. Of the 100 author-identified case-control studies, 83 assessed an exposure-outcome association and, of those, only 54 (65.1%) sampled the study population based on an outcome and would thus be considered case-control designs. Twelve studies were incidence density designs but none used this terminology. Of the studies that reported an odds ratio as the effect measure, none reported on additional considerations that would have enabled a more interpretable result. This survey indicated many case-control-labeled studies were not case-control designs and among case-control studies, key design aspects were not often described. The absence of information about study design elements and underlying assumptions in case-control studies limits the ability to establish the effect measured by the study and the evidentiary value of the study might be underestimated. Copyright © 2016 Elsevier B.V. All rights reserved.

Demographic responses of Pinguicula ionantha to prescribed fire: a regression-design LTRE approach.

PubMed

Kesler, Herbert C; Trusty, Jennifer L; Hermann, Sharon M; Guyer, Craig

2008-06-01

This study describes the use of periodic matrix analysis and regression-design life table response experiments (LTRE) to investigate the effects of prescribed fire on demographic responses of Pinguicula ionantha, a federally listed plant endemic to the herb bog/savanna community in north Florida. Multi-state mark-recapture models with dead recoveries were used to estimate survival and transition probabilities for over 2,300 individuals in 12 populations of P. ionantha. These estimates were applied to parameterize matrix models used in further analyses. P. ionantha demographics were found to be strongly dependent on prescribed fire events. Periodic matrix models were used to evaluate season of burn (either growing or dormant season) for fire return intervals ranging from 1 to 20 years. Annual growing and biannual dormant season fires maximized population growth rates for this species. A regression design LTRE was used to evaluate the effect of number of days since last fire on population growth. Maximum population growth rates calculated using standard asymptotic analysis were realized shortly following a burn event (<2 years), and a regression design LTRE showed that short-term fire-mediated changes in vital rates translated into observed increases in population growth. The LTRE identified fecundity and individual growth as contributing most to increases in post-fire population growth. Our analyses found that the current four-year prescribed fire return intervals used at the study sites can be significantly shortened to increase the population growth rates of this rare species. Understanding the role of fire frequency and season in creating and maintaining appropriate habitat for this species may aid in the conservation of this and other rare herb bog/savanna inhabitants.

College-Readiness Rates of Special Needs High School Graduates in Texas Public Schools

ERIC Educational Resources Information Center

Chandler, Jacob Ross

2013-01-01

Purpose: The purpose of this study was to examine the college-readiness rates of high school graduates in Texas designated as being (a) economically disadvantaged, (b) Limited English Proficient (LEP), or (c) enrolled in special education using archival data from the Texas Education Agency (TEA) Academic Excellence Indicator System (AEIS). Data,…

Presidential Leadership: Improving Completion Rates of Latino Male Students at Texas Community Colleges

ERIC Educational Resources Information Center

Ponjuán, Luis; Palomín, Leticia; Hernández, Susana

2017-01-01

Enrollment rates for Latino male students continue to increase at community colleges; unfortunately, compared to their other racial and/or ethnic male counterparts they are less likely to earn a college credential or degree. This qualitative study explores the narratives of six presidents at Texas community colleges designated as Hispanic-Serving…

A Simple Rate Law Experiment Using a Custom-Built Isothermal Heat Conduction Calorimeter

ERIC Educational Resources Information Center

Wadso, Lars; Li, Xi.

2008-01-01

Most processes (whether physical, chemical, or biological) produce or consume heat: measuring thermal power (the heat production rate) is therefore a typical method of studying processes. Here we describe the design of a simple isothermal heat conduction calorimeter built for use in teaching; we also provide an example of its use in simultaneously…

Assessing Quality of Program Environments for Children and Youth with Autism: Autism Program Environment Rating Scale (APERS)

ERIC Educational Resources Information Center

Odom, Samuel L.; Cox, Ann; Sideris, John; Hume, Kara A.; Hedges, Susan; Kucharczyk, Suzanne; Shaw, Evelyn; Boyd, Brian A.; Reszka, Stephanie; Neitzel, Jennifer

2018-01-01

The purpose of this study was to examine the psychometric properties of the "Autism Program Environment Rating Scale" ("APERS"), an instrument designed to assess quality of program environments for students with autism spectrum disorder. Data sets from two samples of public school programs that provided services to children and…

Aviation Support Equipment Technician E 3 & 2. Rate Training Manual.

ERIC Educational Resources Information Center

Naval Education and Training Command, Pensacola, FL.

The training manual is designed as a self study text for use by Navy and Naval Reserve personnel preparing to meet the professional qualifications for advancement to Petty Officer Third Class and Petty Officer Second Class in the rating of Aviation Support Equipment (ASE) Technician E (Electrical). The first chapter provides information on the…

Use of an E-Reader as a Compensatory Strategy among University Students with Reading Disabilities

ERIC Educational Resources Information Center

Tanners, Adam

2010-01-01

This study investigated the impact of a Kindle e-book reader on the reading rate, comprehension and e-reader acceptance of five postsecondary students with reading disabilities. A single-case Alternating Treatments Design was employed to measure reading rates and reading comprehension. Students were exposed to a series of controlled reading…

Evaluating Texts for Graphical Literacy Instruction: The Graphic Rating Tool

ERIC Educational Resources Information Center

Roberts, Kathryn L.; Brugar, Kristy A.; Norman, Rebecca R.

2015-01-01

In this article, we present the Graphical Rating Tool (GRT), which is designed to evaluate the graphical devices that are commonly found in content-area, non-fiction texts, in order to identify books that are well suited for teaching about those devices. We also present a "best of" list of science and social studies books, which includes…

Exploring Gender and Self-Efficacy Ratings of Athletic Training Students over Time

ERIC Educational Resources Information Center

Carr, W. David; Volberding, Jennifer L.

2014-01-01

Objective: To describe the development of a self-efficacy instrument and to explore the changes by gender in student self-efficacy ratings over 1 year. Design and Setting: An exploratory study utilizing an instrument that measures self-efficacy in undergraduate students in a university setting. Patients or Other Participants: Thirty students (13…

Formative Assessment Using Direct Behavior Ratings: Evaluating Intervention Effects of Daily Behavior Report Cards

ERIC Educational Resources Information Center

Sims, Wesley A.; Riley-Tillman, Chris; Cohen, Daniel R.

2017-01-01

This study examined the treatment sensitivity of "Direct Behavior Rating-Single Item Scales" (DBR-SIS) in response to an evidence-based intervention delivered in a single-case, multiple-baseline design. DBR-SIS was used as a formative assessment in conjunction with a frequently used intervention in schools, a Daily Behavior Report Card…

Parent Use of DRI on High Rate Disruptive Behavior: Direct and Collateral Benefits.

ERIC Educational Resources Information Center

Friman, Patrick C.; Altman, Karl

1990-01-01

This study evaluates parental use of differential reinforcement of other and/or incompatible behavior to treat high-rate disruptive behavior in a severely retarded four-year-old boy. A withdrawal experimental design was used. Intervention effectively reduced instances of toy chewing and throwing, while appropriate toy play and ability to remain…

Personality as a Determinate of Response Dimension Scaling for Likert Rating Categories.

ERIC Educational Resources Information Center

Hensley, Wayne E.; Sanford, David L.

A study was designed to evaluate the use of summated rating (Likert) scales of agreement, evaluation, and frequency. The subjects, 58 female and 45 male college students, rank ordered the descriptive adjectives for the areas of agreement, evaluation, and frequency on a scale of 1 to 100. They also completed the Personal Report of Communication…

Effects of a Group Contingency Strategy on Middle School Physical Education Students' Heart Rates

ERIC Educational Resources Information Center

Vidoni, Carla; Azevedo, Liane; Eberline, Andrew

2012-01-01

The purpose of this study was to assess the effects of a dependent group contingency on eighth-grade students' heart rates. Participants were 18 male and female students. A multielement research design was used to examine the intervention effects. The intervention consisted of: (a) teacher explanation about effort; (b) students' suggestions to…

Student-Student Relations from the Teacher versus Student Perspective: A Multi-Level Confirmatory Factor Analysis

ERIC Educational Resources Information Center

Heemsoth, Tim; Retelsdorf, Jan

2018-01-01

Educational research emphasizes the advantages of multimethod designs. However, if the design comprises different perspectives, the question of construct validity emerges. We related this question to student and teacher ratings of student-student relations, which are of high interest in research on physical education. In our study, 2,160 students…

Effect of Instructional Design on Academic Success of Adult Basic Education Learners: Individualized versus Group Design

ERIC Educational Resources Information Center

Frazier Varner, Debrah

2010-01-01

Many adult basic education (ABE) programs do not achieve a high success rate in meeting student academic needs. Rooted in Knowles' theory of andragogy and Bandura's theory of modeling, this quantitative causal comparative study examined the effects of individualized instruction (IGI) and of facilitated, participatory group programs (SPOKES) on the…

Testing for carryover effects after cessation of treatments: a design approach.

PubMed

Sturdevant, S Gwynn; Lumley, Thomas

2016-08-02

Recently, trials addressing noisy measurements with diagnosis occurring by exceeding thresholds (such as diabetes and hypertension) have been published which attempt to measure carryover - the impact that treatment has on an outcome after cessation. The design of these trials has been criticised and simulations have been conducted which suggest that the parallel-designs used are not adequate to test this hypothesis; two solutions are that either a differing parallel-design or a cross-over design could allow for diagnosis of carryover. We undertook a systematic simulation study to determine the ability of a cross-over or a parallel-group trial design to detect carryover effects on incident hypertension in a population with prehypertension. We simulated blood pressure and focused on varying criteria to diagnose systolic hypertension. Using the difference in cumulative incidence hypertension to analyse parallel-group or cross-over trials resulted in none of the designs having acceptable Type I error rate. Under the null hypothesis of no carryover the difference is well above the nominal 5 % error rate. When a treatment is effective during the intervention period, reliable testing for a carryover effect is difficult. Neither parallel-group nor cross-over designs using the difference in cumulative incidence appear to be a feasible approach. Future trials should ensure their design and analysis is validated by simulation.

Impact of emerging health insurance arrangements on diabetes outcomes and disparities: rationale and study design.

PubMed

Wharam, J Frank; Soumerai, Steve; Trinacty, Connie; Eggleston, Emma; Zhang, Fang; LeCates, Robert; Canning, Claire; Ross-Degnan, Dennis

2013-01-01

Consumer-directed health plans combine lower premiums with high annual deductibles, Internet-based quality-of-care information, and health savings mechanisms. These plans may encourage members to seek better value for health expenditures but may also decrease essential care. The expansion of high-deductible health plans (HDHPs) represents a natural experiment of tremendous proportion. We designed a pre-post, longitudinal, quasi-experimental study to determine the effect of HDHPs on diabetes quality of care, outcomes, and disparities. We will use a 13-year rolling sample (2001-2013) of members of an HDHP and members of a control group. To reduce selection bias, we will limit participants to those whose employers mandate a single health insurance type. The study will measure rates of monthly hemoglobin A1c, lipid, and albuminuria testing; availability of blood glucose test strips; and rates of retinal examinations, high-severity emergency department visits, and preventable hospitalizations. Results could be used to design health plan features that promote high-quality care and better outcomes among people who have diabetes.

Influence of the implant-abutment connection design and diameter on the screw joint stability.

PubMed

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung; Jeong, Chang-Mo

2014-04-01

This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). THE POSTLOAD REMOVAL TORQUE VALUE WAS HIGH IN THE FOLLOWING ORDER WITH REGARD TO MAGNITUDE: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate.

Melt Analysis of Mismatch Amplification Mutation Assays (Melt-MAMA): A Functional Study of a Cost-Effective SNP Genotyping Assay in Bacterial Models

PubMed Central

Birdsell, Dawn N.; Pearson, Talima; Price, Erin P.; Hornstra, Heidie M.; Nera, Roxanne D.; Stone, Nathan; Gruendike, Jeffrey; Kaufman, Emily L.; Pettus, Amanda H.; Hurbon, Audriana N.; Buchhagen, Jordan L.; Harms, N. Jane; Chanturia, Gvantsa; Gyuranecz, Miklos; Wagner, David M.; Keim, Paul S.

2012-01-01

Single nucleotide polymorphisms (SNPs) are abundant in genomes of all species and biologically informative markers extensively used across broad scientific disciplines. Newly identified SNP markers are publicly available at an ever-increasing rate due to advancements in sequencing technologies. Efficient, cost-effective SNP genotyping methods to screen sample populations are in great demand in well-equipped laboratories, but also in developing world situations. Dual Probe TaqMan assays are robust but can be cost-prohibitive and require specialized equipment. The Mismatch Amplification Mutation Assay, coupled with melt analysis (Melt-MAMA), is flexible, efficient and cost-effective. However, Melt-MAMA traditionally suffers from high rates of assay design failures and knowledge gaps on assay robustness and sensitivity. In this study, we identified strategies that improved the success of Melt-MAMA. We examined the performance of 185 Melt-MAMAs across eight different pathogens using various optimization parameters. We evaluated the effects of genome size and %GC content on assay development. When used collectively, specific strategies markedly improved the rate of successful assays at the first design attempt from ∼50% to ∼80%. We observed that Melt-MAMA accurately genotypes across a broad DNA range (∼100 ng to ∼0.1 pg). Genomic size and %GC content influence the rate of successful assay design in an independent manner. Finally, we demonstrated the versatility of these assays by the creation of a duplex Melt-MAMA real-time PCR (two SNPs) and conversion to a size-based genotyping system, which uses agarose gel electrophoresis. Melt-MAMA is comparable to Dual Probe TaqMan assays in terms of design success rate and accuracy. Although sensitivity is less robust than Dual Probe TaqMan assays, Melt-MAMA is superior in terms of cost-effectiveness, speed of development and versatility. We detail the parameters most important for the successful application of Melt-MAMA, which should prove useful to the wider scientific community. PMID:22438886

Influence of the implant-abutment connection design and diameter on the screw joint stability

PubMed Central

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung

2014-01-01

PURPOSE This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. MATERIALS AND METHODS Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). RESULTS The postload removal torque value was high in the following order with regard to magnitude: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). CONCLUSION The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate. PMID:24843398

The Impact of Part-Time Staff on Art & Design Students' Ratings of Their Programmes

ERIC Educational Resources Information Center

Yorke, Mantz

2014-01-01

Art & Design receives ratings on a number of scales of the UK's National Student Survey (NSS) that are less strong than those for some other subject areas. Art & Design, along with performing arts, is characterised by a relatively high level of part-time (PT) staffing. PT staffing data are set against NSS ratings for post-92 universities…

System Design for FEC in Aeronautical Telemetry

DTIC Science & Technology

2012-03-12

rate punctured convolutional codes for soft decision Viterbi...below follows that given in [8]. The final coding rate of exactly 2/3 is achieved by puncturing the rate -1/2 code as follows. We begin with the buffer c1...concatenated convolutional code (SCCC). The contributions of this paper are on the system-design level. One major contribution is to design a SCCC code

A replication of the relationship between elderly suicides rates and elderly dependency ratios: a cross-national study.

PubMed

Shah, Ajit

2010-01-01

A positive correlation between elderly dependency ratios and elderly suicide rates has been observed using one-year cross-sectional data on elderly suicide rates. A cross-national study designed to replicate this positive correlation between elderly dependency ratios and elderly suicide rates was undertaken by: (i) using one-year average of five years data on suicide rates; and (ii) using more recent data on both elderly suicide rates and elderly dependency ratios. Data on elderly suicide rates, and the total number of elderly and young people was ascertained from the World Health Organization website. The main findings were of significant positive correlations between elderly dependency ratios and suicide rates in both sexes in both the elderly age-bands (65-74 years and 75+ years). The replication of the positive correlations between elderly dependency ratios and elderly suicide rates by using one-year average of five years data on suicide rates suggests that this relationship is robust and accurate. ‎

A replication of the relationship between elderly suicides rates and elderly dependency ratios: cross-national study

PubMed Central

Shah, Ajit

2010-01-01

Abstract: Background: A positive correlation between elderly dependency ratios and elderly suicide rates has been observed using one-year cross-sectional data on elderly suicide rates. Methods: A cross-national study designed to replicate this positive correlation between elderly dependency ratios and elderly suicide rates was undertaken by: (i) using one-year average of five years data on suicide rates; and (ii) using more recent data on both elderly suicide rates and elderly dependency ratios. Data on elderly suicide rates, and the total number of elderly and young people was ascertained from the World Health Organization website. Results: The main findings were of significant positive correlations between elderly dependency ratios and suicide rates in both sexes in both the elderly age-bands (65-74 years and 75+ years). Conclusions: The replication of the positive correlations between elderly dependency ratios and elderly suicide rates by using one-year average of five years data on suicide rates suggests that this relationship is robust and accurate. PMID:21483194

Observing relationships in Finnish adoptive families: Oulu Family Rating Scale.

PubMed

Tienari, Pekka; Wynne, Lyman C; Sorri, Anneli; Lahti, Ilpo; Moring, Juha; Nieminen, Pentti; Joukamaa, Matti; Naarala, Mikko; Seitamaa, Markku; Wahlberg, Karl-Erik; Miettunen, Jouko

2005-01-01

Adoption studies were intended to separate genetic from environmental "causal" factors. In earlier adoption studies, psychiatric diagnostic labels for the adoptive parents were used as a proxy for the multiple dimensions of the family rearing environment. In the Finnish Adoption Study, research design provided the opportunity to study directly the adoptive family rearing environment. For this purpose 33 sub-scales were selected creating what we call Oulu Family Rating Scale (OPAS, Oulun PerheArviointiSkaala). In this paper, the manual for scoring of these sub-scales is presented.

What currency do bumble bees maximize?

PubMed

Charlton, Nicholas L; Houston, Alasdair I

2010-08-16

In modelling bumble bee foraging, net rate of energetic intake has been suggested as the appropriate currency. The foraging behaviour of honey bees is better predicted by using efficiency, the ratio of energetic gain to expenditure, as the currency. We re-analyse several studies of bumble bee foraging and show that efficiency is as good a currency as net rate in terms of predicting behaviour. We suggest that future studies of the foraging of bumble bees should be designed to distinguish between net rate and efficiency maximizing behaviour in an attempt to discover which is the more appropriate currency.

What Currency Do Bumble Bees Maximize?

PubMed Central

Charlton, Nicholas L.; Houston, Alasdair I.

2010-01-01

In modelling bumble bee foraging, net rate of energetic intake has been suggested as the appropriate currency. The foraging behaviour of honey bees is better predicted by using efficiency, the ratio of energetic gain to expenditure, as the currency. We re-analyse several studies of bumble bee foraging and show that efficiency is as good a currency as net rate in terms of predicting behaviour. We suggest that future studies of the foraging of bumble bees should be designed to distinguish between net rate and efficiency maximizing behaviour in an attempt to discover which is the more appropriate currency. PMID:20808437

A piloted simulator investigation of augmentation systems to improve helicopter nap-of-the-earth handling qualities

NASA Technical Reports Server (NTRS)

Chen, R. T. N.; Talbot, P. D.; Gerdes, R. M.; Dugan, D. C.

1978-01-01

A piloted simulation study assessed various levels of stability and control augmentation designed to improve the handling qualities of several helicopters in nap-of-the-earth (NOE) flight. Five basic single rotor helicopters - one teetering, two articulated, and two hingeless - which were found to have a variety of major deficiencies in a previous fixed-based simulator study were selected as baseline configurations. The stability and control augmentation systems (SCAS) include simple control augmentation systems (CAS) to decouple pitch and yaw responses due to collective input and to quicken the pitch and roll control responses; SCAS of rate command type designed to optimize the sensitivity and damping and to decouple the pitch-roll due to aircraft angular rate; and attitude command type SCAS. Pilot ratings and commentary are presented as well as performance data related to the task. SCAS control usage and their gain levels associated with specific rotor type are also discussed.

The Need of Slanted Side Holes for Venous Cannulae

PubMed Central

Park, Joong Yull

2012-01-01

Well-designed cannulae must allow good flow rate and minimize nonphysiologic load. Venous cannulae generally have side holes to prevent the rupture of blood vessel during perfusion. Optimizing side hole angle will yield more efficient and safe venous cannulae. A numerical modeling was used to study the effect of the angle (0°–45°) and number (0–12) of side holes on the performance of cannulae. By only slanting the side holes, it increases the flow rate up to 6% (in our models). In addition, it was found that increasing the number of side holes reduces the shear rate up to 12% (in our models). A new parameter called “penetration depth” was introduced to describe the interfering effect of stream jets from side holes, and the result showed that the 45°-slanted side holes caused minimum interfering for the flow in cannula. Our quantitative hemodynamic analysis study provides important guidelines for venous cannulae design. PMID:22291856

Study of different cross-shaped microchannels affecting thermal-bubble-actuated microparticle manipulation

NASA Astrophysics Data System (ADS)

Li, Weichen; Tsou, Chingfu

2015-10-01

This paper presents a thermal-bubble-actuated microfluidic chip with cross-shaped microchannels for evaluating the effect of different microchannel designs on microparticle manipulation. Four cross-shaped microchannel designs, with orthogonal, misaligned, skewed, and antiskewed types, were proposed in this study. The thermal bubble micropump, which is based on a resistive bulk microheater, was used to drive fluid transportation, and it can be realized using a simple microfabrication process with a silicon-on-isolator wafer. Using commercial COMSOL software, the flow profiles of microfluidics in various cross-shaped microchannels were simulated qualitatively under different pumping pressures. Microbeads, with a diameter of 20 μm, manipulated in four cross-shaped microchannels, were also implemented in this experiment. The results showed that a skewed microchannel design has a higher sorting rate compared with orthogonal, misaligned, and antiskewed microchannels because its flow velocity in the main microchannel is significantly reduced by pumping pressure. Typically, the successful sorting rate for this type of skewed microchannel can reach 30% at a pumping frequency of 100 Hz.

Fabrication of microfluidic architectures for optimal flow rate and concentration measurement for lab on chip application

NASA Astrophysics Data System (ADS)

Adam, Tijjani; Hashim, U.

2017-03-01

Optimum flow in micro channel for sensing purpose is challenging. In this study, The optimizations of the fluid sample flows are made through the design and characterization of the novel microfluidics' architectures to achieve the optimal flow rate in the micro channels. The biocompatibility of the Polydimetylsiloxane (Sylgard 184 silicon elastomer) polymer used to fabricate the device offers avenue for the device to be implemented as the universal fluidic delivery system for bio-molecules sensing in various bio-medical applications. The study uses the following methodological approaches, designing a novel microfluidics' architectures by integrating the devices on a single 4 inches silicon substrate, fabricating the designed microfluidic devices using low-cost solution soft lithography technique, characterizing and validating the flow throughput of urine samples in the micro channels by generating pressure gradients through the devices' inlets. The characterization on the urine samples flow in the micro channels have witnessed the constant flow throughout the devices.

An event-related potential study of semantic style-match judgments of artistic furniture.

PubMed

Lin, Ming-Huang; Wang, Ching-yi; Cheng, Shih-kuen; Cheng, Shih-hung

2011-11-01

This study investigates how semantic networks represent different artistic furniture. Event-related potentials (ERPs) were recorded while participants made style-match judgments for table and chair sets. All of the tables were in the Normal style, whereas the chairs were in the Normal, Minimal, ReadyMade, or Deconstruction styles. The Normal and Minimal chairs had the same rates of "match" responses, which were both higher than the rates for the ReadyMade and Deconstruction chairs. Compared with Normal chairs, the ERPs elicited by both ReadyMade chairs and Deconstruction chairs exhibited reliable N400 effects, which suggests that these two design styles were unlike the Normal design style. However, Minimal chairs evoked ERPs that were similar to the ERPs of Normal chairs. Furthermore, the N400 effects elicited by ReadyMade and Deconstruction chairs showed different scalp distributions. These findings reveal that semantic networks represent different design styles for items of the same category. Copyright © 2011 Elsevier B.V. All rights reserved.

Solar Probe thermal shield design and testing

NASA Technical Reports Server (NTRS)

Millard, Jerry M.; Miyake, Robert N.; Rainen, Richard A.

1992-01-01

This paper discusses the major thermal shield subsystem development activities in support of the Solar Probe study being conducted at JPL. The Solar Probe spacecraft will travel to within 4 solar radii of the sun's center to perform fundamental experiments in space physics. Exposure to 2900 earth suns at perihelion requires the spacecraft to be protected within the shadow envelope of a protective shield. In addition, the mass loss rate off of the shield at elevated temperature must comply with plasma instrument requirements and has become the driver of the shield design. This paper will focus on the analytical design work to size the shield and control the shield mass loss rate for the various spacecraft options under study, the application of carbon-carbon materials for shield components, development and preparation of carbon-carbon samples for materials testing, and a materials testing program for carbon-carbon and tungsten alloys to investigate thermal/optical properties, mass loss (carbon-carbon only), material integrity, and high velocity impact behavior.

Laser dynamics: The system dynamics and network theory of optoelectronic integrated circuit design

NASA Astrophysics Data System (ADS)

Tarng, Tom Shinming-T. K.

Laser dynamics is the system dynamics, communication and network theory for the design of opto-electronic integrated circuit (OEIC). Combining the optical network theory and optical communication theory, the system analysis and design for the OEIC fundamental building blocks is considered. These building blocks include the direct current modulation, inject light modulation, wideband filter, super-gain optical amplifier, E/O and O/O optical bistability and current-controlled optical oscillator. Based on the rate equations, the phase diagram and phase portrait analysis is applied to the theoretical studies and numerical simulation. The OEIC system design methodologies are developed for the OEIC design. Stimulating-field-dependent rate equations are used to model the line-width narrowing/broadening mechanism for the CW mode and frequency chirp of semiconductor lasers. The momentary spectra are carrier-density-dependent. Furthermore, the phase portrait analysis and the nonlinear refractive index is used to simulate the single mode frequency chirp. The average spectra of chaos, period doubling, period pulsing, multi-loops and analog modulation are generated and analyzed. The bifurcation-chirp design chart with modulation depth and modulation frequency as parameters is provided for design purpose.

Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology.

PubMed

Schreiber, Eric C; Chang, Sha X

2012-08-01

Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 μm at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy∕min∕A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 μm. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm. Monte Carlo simulations demonstrate that the proposed compact MRT system design is capable of delivering a sufficient dose rate and peak-to-valley ratio for small animal MRT studies.

An empirical study of software design practices

NASA Technical Reports Server (NTRS)

Card, David N.; Church, Victor E.; Agresti, William W.

1986-01-01

Software engineers have developed a large body of software design theory and folklore, much of which was never validated. The results of an empirical study of software design practices in one specific environment are presented. The practices examined affect module size, module strength, data coupling, descendant span, unreferenced variables, and software reuse. Measures characteristic of these practices were extracted from 887 FORTRAN modules developed for five flight dynamics software projects monitored by the Software Engineering Laboratory (SEL). The relationship of these measures to cost and fault rate was analyzed using a contingency table procedure. The results show that some recommended design practices, despite their intuitive appeal, are ineffective in this environment, whereas others are very effective.

Development of system design information for carbon dioxide using an amine type sorber

NASA Technical Reports Server (NTRS)

Rankin, R. L.; Roehlich, F.; Vancheri, F.

1971-01-01

Development work on system design information for amine type carbon dioxide sorber is reported. Amberlite IR-45, an aminated styrene divinyl benzene matrix, was investigated to determine the influence of design parameters of sorber particle size, process flow rate, CO2 partial pressure, total pressure, and bed designs. CO2 capacity and energy requirements for a 4-man size system were related mathematically to important operational parameters. Some fundamental studies in CO2 sorber capacity, energy requirements, and process operation were also performed.

Improving Student Commitment to Healthcare-Related Design Practice by Improving the Studio Learning Experience.

PubMed

Tan, Lindsay; Hong, Miyoung; Albert, Taneshia West

2017-10-01

This case study explores the influence of the healthcare design studio experience on students' short-term professional goals as measured through rates of healthcare-related certification and internship/employment. The value and relevance of interior design is evident in the healthcare design sector. However, interior design students may not perceive this value if it is not communicated through their design education. Students' experience in the design studio plays a crucial role in determining career choices, and students may be more committed to career goals when there is clear connection between major coursework and professional practice. The authors compared healthcare-related certification and internship/employment levels between two student cohorts in a capstone undergraduate interior design healthcare design studio course. The first cohort was led by the existing curriculum. The second cohort was led by the revised curriculum that specifically aimed at encouraging students to commit to healthcare-related design practice. When measured at 3 months from graduation, the second cohort, led by the revised curriculum, saw a 30% increase in Evidence-based Design Accreditation and Certification exam pass rates and a 40% increase in healthcare-related internship/employment. The challenge of interior design education is to instill in emerging professionals not only professional competence but also those professional attitudes that will make them better prepared to design spaces that improve quality of life, particularly in healthcare environments. The results exceeded the project goals, and so this could be considered a promising practice for courses focused on healthcare design education.

Simplified, inverse, ejector design tool

NASA Technical Reports Server (NTRS)

Dechant, Lawrence J.

1993-01-01

A simple lumped parameter based inverse design tool has been developed which provides flow path geometry and entrainment estimates subject to operational, acoustic, and design constraints. These constraints are manifested through specification of primary mass flow rate or ejector thrust, fully-mixed exit velocity, and static pressure matching. Fundamentally, integral forms of the conservation equations coupled with the specified design constraints are combined to yield an easily invertible linear system in terms of the flow path cross-sectional areas. Entrainment is computed by back substitution. Initial comparison with experimental and analogous one-dimensional methods show good agreement. Thus, this simple inverse design code provides an analytically based, preliminary design tool with direct application to High Speed Civil Transport (HSCT) design studies.

Study on ablation behavior of silicone rubber based insulation material under the condition of boron oxide particles erosion

NASA Astrophysics Data System (ADS)

Zha, B. L.; Shi, Y. A.; Wang, J. J.; Su, Q. D.

2018-01-01

Self-designed oxygen-kerosene ablation system was employed to study the ablation characteristics of silicone rubber based thermal insulation materials under the condition of boron oxide particles erosion. The ablation test was designed with a mass fraction of 1.69% boron oxide particles and particles-free, the microstructure and elemental analysis of the specimens before and after ablation were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersion Spectrum (EDS). Experiment results show that the average mass ablation rate of the materials was 0.0099 g•s-1 and the average ablation rate was -0.025 mm•s-1 under the condition of pure gas phase ablation; and the average mass ablation rate of the multiphase ablation test group was 0.1775 g•s-1, whose average ablation rate was 0.437 mm•s-1 during the ablation process, the boron oxide particles would adhere a molten layer on the flame contact surface of the specimen, which covering the pores on the material surface, blocking the infiltration channel for the oxidizing component and slowing down the oxidation loss rate of the material below the surface, but because the particles erosion was the main reason for material depletion, the combined effect of the above both led to the upward material ablation rates of Silicone Rubber.

Control structures for high speed processors

NASA Technical Reports Server (NTRS)

Maki, G. K.; Mankin, R.; Owsley, P. A.; Kim, G. M.

1982-01-01

A special processor was designed to function as a Reed Solomon decoder with throughput data rate in the Mhz range. This data rate is significantly greater than is possible with conventional digital architectures. To achieve this rate, the processor design includes sequential, pipelined, distributed, and parallel processing. The processor was designed using a high level language register transfer language. The RTL can be used to describe how the different processes are implemented by the hardware. One problem of special interest was the development of dependent processes which are analogous to software subroutines. For greater flexibility, the RTL control structure was implemented in ROM. The special purpose hardware required approximately 1000 SSI and MSI components. The data rate throughput is 2.5 megabits/second. This data rate is achieved through the use of pipelined and distributed processing. This data rate can be compared with 800 kilobits/second in a recently proposed very large scale integration design of a Reed Solomon encoder.

Freeze-drying of nanosuspensions, 1: freezing rate versus formulation design as critical factors to preserve the original particle size distribution.

PubMed

Beirowski, Jakob; Inghelbrecht, Sabine; Arien, Albertina; Gieseler, Henning

2011-05-01

It has been recently reported in the literature that using a fast freezing rate during freeze-drying of drug nanosuspensions is beneficial to preserve the original particle size distribution. All freezing rates studied were obtained by utilizing a custom-made apparatus and were then indirectly related to conventional vial freeze-drying. However, a standard freeze-dryer is only capable of achieving moderate freezing rates in the shelf fluid circulation system. Therefore, it was the purpose of the present study to evaluate the possibility to establish a typical freezing protocol applicable to a standard freeze-drying unit in combination with an adequate choice of cryoprotective excipients and steric stabilizers to preserve the original particle size distribution. Six different drug nanosuspensions containing itraconazole as a drug model were studied using freeze-thaw experiments and a full factorial design to reveal major factors for the stabilization of drug nanosuspensions and the corresponding interactions. In contrast to previous reports, the freezing regime showed no significant influence on preserving the original particle size distribution, suggesting that the concentrations of both the steric stabilizer and the cryoprotective agent are optimized. Moreover, it could be pinpointed that the combined effect of steric stabilizer and cryoprotectant clearly contribute to nanoparticle stability. Copyright © 2010 Wiley-Liss, Inc.

Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure Validation Simulation Study

NASA Technical Reports Server (NTRS)

Murdoch, Jennifer L.; Bussink, Frank J. L.; Chamberlain, James P.; Chartrand, Ryan C.; Palmer, Michael T.; Palmer, Susan O.

2008-01-01

The Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure (ITP) Validation Simulation Study investigated the viability of an ITP designed to enable oceanic flight level changes that would not otherwise be possible. Twelve commercial airline pilots with current oceanic experience flew a series of simulated scenarios involving either standard or ITP flight level change maneuvers and provided subjective workload ratings, assessments of ITP validity and acceptability, and objective performance measures associated with the appropriate selection, request, and execution of ITP flight level change maneuvers. In the majority of scenarios, subject pilots correctly assessed the traffic situation, selected an appropriate response (i.e., either a standard flight level change request, an ITP request, or no request), and executed their selected flight level change procedure, if any, without error. Workload ratings for ITP maneuvers were acceptable and not substantially higher than for standard flight level change maneuvers, and, for the majority of scenarios and subject pilots, subjective acceptability ratings and comments for ITP were generally high and positive. Qualitatively, the ITP was found to be valid and acceptable. However, the error rates for ITP maneuvers were higher than for standard flight level changes, and these errors may have design implications for both the ITP and the study's prototype traffic display. These errors and their implications are discussed.

HYPOTHESIS TESTING FOR HIGH-DIMENSIONAL SPARSE BINARY REGRESSION

PubMed Central

Mukherjee, Rajarshi; Pillai, Natesh S.; Lin, Xihong

2015-01-01

In this paper, we study the detection boundary for minimax hypothesis testing in the context of high-dimensional, sparse binary regression models. Motivated by genetic sequencing association studies for rare variant effects, we investigate the complexity of the hypothesis testing problem when the design matrix is sparse. We observe a new phenomenon in the behavior of detection boundary which does not occur in the case of Gaussian linear regression. We derive the detection boundary as a function of two components: a design matrix sparsity index and signal strength, each of which is a function of the sparsity of the alternative. For any alternative, if the design matrix sparsity index is too high, any test is asymptotically powerless irrespective of the magnitude of signal strength. For binary design matrices with the sparsity index that is not too high, our results are parallel to those in the Gaussian case. In this context, we derive detection boundaries for both dense and sparse regimes. For the dense regime, we show that the generalized likelihood ratio is rate optimal; for the sparse regime, we propose an extended Higher Criticism Test and show it is rate optimal and sharp. We illustrate the finite sample properties of the theoretical results using simulation studies. PMID:26246645

Allowing for population stratification in case-only studies of gene-environment interaction, using genomic control.

PubMed

Yadav, Pankaj; Freitag-Wolf, Sandra; Lieb, Wolfgang; Dempfle, Astrid; Krawczak, Michael

2015-10-01

Gene-environment interactions (G × E) have attracted considerable research interest in the past owing to their scientific and public health implications, but powerful statistical methods are required to successfully track down G × E, particularly at a genome-wide level. Previously, a case-only (CO) design has been proposed as a means to identify G × E with greater efficiency than traditional case-control or cohort studies. However, as with genotype-phenotype association studies themselves, hidden population stratification (PS) can impact the validity of G × E studies using a CO design. Since this problem has been subject to little research to date, we used comprehensive simulation to systematically assess the type I error rate, power and effect size bias of CO studies of G × E in the presence of PS. Three types of PS were considered, namely genetic-only (PSG), environment-only (PSE), and joint genetic and environmental stratification (PSGE). Our results reveal that the type I error rate of an unadjusted Wald test, appropriate for the CO design, would be close to its nominal level (0.05 in our study) as long as PS involves only one interaction partner (i.e., either PSG or PSE). In contrast, if the study population is stratified with respect to both G and E (i.e., if there is PSGE), then the type I error rate is seriously inflated and estimates of the underlying G × E interaction are biased. Comparison of CO to a family-based case-parents design confirmed that the latter is more robust against PSGE, as expected. However, case-parent trios may be particularly unsuitable for G × E studies in view of the fact that they require genotype data from parents and that many diseases with an environmental component are likely to be of late onset. An alternative approach to adjusting for PS is principal component analysis (PCA), which has been widely used for this very purpose in past genome-wide association studies (GWAS). However, resolving genetic PS properly by PCA requires genetic data at the population level, the availability of which would conflict with the basic idea of the CO design. Therefore, we explored three modified Wald test statistics, inspired by the genomic control (GC) approach to GWAS, as an alternative means to allow for PSGE. The modified statistics were benchmarked against a stratified Wald test assuming known population affiliation, which should provide maximum power under PS. Our results confirm that GC is capable of successfully and efficiently correcting the PS-induced inflation of the type I error rate in CO studies of G × E.

Sampling design by the core-food approach for the Taiwan total diet study on veterinary drugs.

PubMed

Chen, Chien-Chih; Tsai, Ching-Lun; Chang, Chia-Chin; Ni, Shih-Pei; Chen, Yi-Tzu; Chiang, Chow-Feng

2017-06-01

The core-food (CF) approach, first adopted in the United States in the 1980s, has been widely used by many countries to assess the exposure to dietary hazards at a population level. However, the reliability of exposure estimates (C × CR) depends critically on sampling methods designed for the detected chemical concentrations (C) of each CF to match with the corresponding consumption rate (CR) estimated from the surveyed intake data. In order to reduce the uncertainty of food matching, this study presents a sampling design scheme, namely the subsample method, for the 2016 Taiwan total diet study (TDS) on veterinary drugs. We first combined the four sets of national dietary recall data that covered the entire age strata (1-65+ years), and aggregated them into 307 CFs by their similarity in nutritional values, manufacturing and cooking methods. The 40 CFs pertinent to veterinary drug residues were selected for this study, and 16 subsamples for each CF were designed by weighing their quantities in CR, product brands, manufacturing, processing and cooking methods. The calculated food matching rates of each CF from this study were 84.3-97.3%, which were higher than those obtained from many previous studies using the representative food (RF) method (53.1-57.8%). The subsample method not only considers the variety of food processing and cooking methods, but also it provides better food matching and reduces the uncertainty of exposure assessment.

Insulin pump therapy: what is the evidence for using different types of boluses for coverage of prandial insulin requirements?

PubMed

Heinemann, Lutz

2009-11-01

Bolus infusion of insulin along with a meal is a standard procedure with continuous subcutaneous insulin infusion. Modern insulin pumps allow applying this bolus in four different ways: infusion of the total dose at once or splitting the dose into two boluses, infusion of a part of the bolus in the usual manner plus infusion of the other part over a prolonged period of time (with a higher infusion rate than the basal rate), or infusion of the total dose in the form of an elevated basal rate. Depending on the composition of the given meal and its glycemic index, this is an attempt to match the circulating insulin levels to the rate of glucose absorption from the gut in order to minimize postprandial glycemic excursions. However, in the framework of evidence-based medicine, the benefits of this approach should be proven in appropriately designed clinical studies. Performance of meal-related studies requires careful attention to many aspects in order to allow meaningful evaluation of a given intervention (i.e., type of bolus). Critical evaluation of the clinical experimental studies and the one clinical study published about the impact of different types of boluses on postprandial metabolic control revealed fundamental shortcomings in study design and performance in these studies. Insufficient establishment of comparable preprandial glycemia and insulinemia on the different study days within and between the patients studied is one key aspect. Therefore, the recommendation made in most of these studies (i.e., use of dual-wave bolus) has to be accepted with care, until we have better evidence.

Technology and operational considerations for low-heat-rate trajectories. [of future winged earth reentry vehicles

NASA Technical Reports Server (NTRS)

Wurster, K. E.; Eldred, C. H.

1979-01-01

A broad parametric study which examines several critical aspects of low-heat-rate entry trajectories is performed. Low planform loadings associated with future winged earth-entry vehicles coupled with the potential application of metallic thermal protection systems (TPS) suggest that such trajectories are of particular interest. Studied are three heating conditions - reference, stagnation, and windward centerline, for both laminar and turbulent flow; configuration-related factors including planform loading and hypersonic angle of attack; and mission-related factors such as cross-range and orbit inclination. Results indicate benefits in the design of TPS to be gained by utilizing moderate angles of attack as opposed to high-lift coefficient, high angles of attack, during entry. An assessment of design and technology implications is made.

The problem is not just sample size: the consequences of low base rates in policing experiments in smaller cities.

PubMed

Hinkle, Joshua C; Weisburd, David; Famega, Christine; Ready, Justin

2013-01-01

Hot spots policing is one of the most influential police innovations, with a strong body of experimental research showing it to be effective in reducing crime and disorder. However, most studies have been conducted in major cities, and we thus know little about whether it is effective in smaller cities, which account for a majority of police agencies. The lack of experimental studies in smaller cities is likely in part due to challenges designing statistically powerful tests in such contexts. The current article explores the challenges of statistical power and "noise" resulting from low base rates of crime in smaller cities and provides suggestions for future evaluations to overcome these limitations. Data from a randomized experimental evaluation of broken windows policing in hot spots are used to illustrate the challenges that low base rates present for evaluating hot spots policing programs in smaller cities. Analyses show low base rates make it difficult to detect treatment effects. Very large effect sizes would be required to reach sufficient power, and random fluctuations around low base rates make detecting treatment effects difficult, irrespective of power, by masking differences between treatment and control groups. Low base rates present strong challenges to researchers attempting to evaluate hot spots policing in smaller cities. As such, base rates must be taken directly into account when designing experimental evaluations. The article offers suggestions for researchers attempting to expand the examination of hot spots policing and other microplace-based interventions to smaller jurisdictions.

Systematic Review and Meta-analysis: Placebo Rates in Induction and Maintenance Trials of Ulcerative Colitis.

PubMed

Jairath, Vipul; Zou, Guangyong; Parker, Claire E; Macdonald, John K; Mosli, Mahmoud H; Khanna, Reena; Shackelton, Lisa M; Vandervoort, Margaret K; AlAmeel, Turki; Al Beshir, Mohammad; AlMadi, Majid; Al-Taweel, Talal; Atkinson, Nathan S S; Biswas, Sujata; Chapman, Thomas P; Dulai, Parambir S; Glaire, Mark A; Hoekman, Daniel; Koutsoumpas, Andreas; Minas, Elizabeth; Samaan, Mark A; Travis, Simon; D'Haens, Geert; Levesque, Barrett G; Sandborn, William J; Feagan, Brian G

2016-05-01

Minimisation of the placebo responses in randomised controlled trials [RCTs] is essential for efficient evaluation of new interventions. Placebo rates have been high in ulcerative colitis [UC] clinical trials, and factors influencing this are poorly understood. We quantify placebo response and remission rates in UC RCTs and identify trial design factors influencing them. MEDLINE, EMBASE, and the Cochrane Library were searched from inception through April 2014 for placebo-controlled trials in adult patients with UC of a biological agent, corticosteroid, immunosuppressant, or aminosalicylate. Data were independently doubly extracted. Quality was assessed using the Cochrane risk of bias tool. In all, 51 trials [48 induction and 10 maintenance phases] were identified. Placebo response and remission rates were pooled according to random-effects models, and mixed-effects meta-regression models were used to evaluate effects of study-level characteristics on these rates. Pooled estimates of placebo remission and response rates for induction trials were 10% (95% confidence interval [CI] 7-13%) and 33% [95% CI 29-37%], respectively. Corresponding values for maintenance trials were 19% [95% CI 11-30%] and 22% [95% CI 17-28%]. Trials enrolling patients with more active disease confirmed by endoscopy [endoscopy subscore ≥ 2] were associated with lower placebo rates. Conversely, placebo rates increased with increasing trial duration and number of study visits. Objective assessment of greater disease activity at trial entry by endoscopy lowered placebo rates, whereas increasing trial duration and more interactions with healthcare providers increased placebo rates. These findings have important implications for design and conduct of clinical trials. Copyright © 2016 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Developing an analytical tool for evaluating EMS system design changes and their impact on cardiac arrest outcomes: combining geographic information systems with register data on survival rates

PubMed Central

2013-01-01

Background Out-of-hospital cardiac arrest (OHCA) is a frequent and acute medical condition that requires immediate care. We estimate survival rates from OHCA in the area of Stockholm, through developing an analytical tool for evaluating Emergency Medical Services (EMS) system design changes. The study also is an attempt to validate the proposed model used to generate the outcome measures for the study. Methods and results This was done by combining a geographic information systems (GIS) simulation of driving times with register data on survival rates. The emergency resources comprised ambulance alone and ambulance plus fire services. The simulation model predicted a baseline survival rate of 3.9 per cent, and reducing the ambulance response time by one minute increased survival to 4.6 per cent. Adding the fire services as first responders (dual dispatch) increased survival to 6.2 per cent from the baseline level. The model predictions were validated using empirical data. Conclusion We have presented an analytical tool that easily can be generalized to other regions or countries. The model can be used to predict outcomes of cardiac arrest prior to investment in EMS design changes that affect the alarm process, e.g. (1) static changes such as trimming the emergency call handling time or (2) dynamic changes such as location of emergency resources or which resources should carry a defibrillator. PMID:23415045

Evaluation of High-Speed Civil Transport Handling Qualities Criteria with Supersonic Flight Data

NASA Technical Reports Server (NTRS)

Cox, Timothy H.; Jackson, Dante W.

1997-01-01

Most flying qualities criteria have been developed from data in the subsonic flight regime. Unique characteristics of supersonic flight raise questions about whether these criteria successfully extend into the supersonic flight regime. Approximately 25 years ago NASA Dryden Flight Research Center addressed this issue with handling qualities evaluations of the XB-70 and YF-12. Good correlations between some of the classical handling qualities parameters, such as the control anticipation parameter as a function of damping, were discovered. More criteria have been developed since these studies. Some of these more recent criteria are being used in designing the High-Speed Civil Transport (HSCT). A second research study recently addressed this issue through flying qualities evaluations of the SR-71 at Mach 3. The research goal was to extend the high-speed flying qualities experience of large airplanes and to evaluate more recent MIL-STD-1797 criteria against pilot comments and ratings. Emphasis was placed on evaluating the criteria used for designing the HSCT. XB-70 and YF-12 data from the previous research supplemented the SR-71 data. The results indicate that the criteria used in the HSCT design are conservative and should provide good flying qualities for typical high-speed maneuvering. Additional results show correlation between the ratings and comments and criteria for gradual maneuvering with precision control. Correlation is shown between ratings and comments and an extension of the Neal/Smith criterion using normal acceleration instead of pitch rate.

Comparison of Inversion (“flipping”) Rates Among Different Port Designs: A Single-Center Experience

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

Etezadi, Vahid, E-mail: vahid.etezadi@umm.edu; Trerotola, Scott O., E-mail: streroto@uphs.upenn.edu

PurposeTo compare incidence of port inversion among different types of implantable venous access devices.Materials and Methods Records of patients who underwent imaging-guided subcutaneous port placement without port fixation between July 2001 and April 2015 were reviewed with use of a quality assurance database. 1930 patients with complete follow-up (death or explant) were included in the study. Collected data included date and indication for port placement, port type, venous access site, immediate and long-term complications, indication for removal, and total number of catheter days. BMI of patients with inverted ports was also calculated.Results Port inversion within the pocket was observed inmore » 18 patients (0.9%) including 7/82 (9%) of Dignity ports, 4/126 (3%) of Vaxcel plastic arm ports, 3/142 (2%) of Smartports, 2/100 (2%) of Powerports, 1/14 (7%) of Vaccess ports, and 1/1421 (0.07%) of Vortex LP ports. Among these designs, the inversion rate was significantly lower in Vortex LP ports (0.1%) (P < 0.05). There was a trend toward higher inversion rate of Dignity ports, which have a rectangular design with a relatively narrow base. Mean dwell in inverted ports was 114 days (7–580).Conclusion The incidence of port inversion without suture fixation of the port base to the pocket is extremely low. The present study shows differences in inversion incidence based on port design.Level of Evidence: Case Series, Level IV.« less

Fourth-Grade Children are Less Accurate in Reporting School Breakfast than School Lunch during 24-Hour Dietary Recalls

PubMed Central

Baxter, Suzanne Domel; Royer, Julie A.; Hardin, James W.; Guinn, Caroline H.; Smith, Albert F.

2008-01-01

Objective To compare reporting accuracy for breakfast and lunch in two studies. Design Children were observed eating school meals and interviewed the following morning about the previous day. Study 1 – 104 children were each interviewed one to three times with ≥25 days separating any two interviews. Study 2 – 121 children were each interviewed once in forward (morning-to-evening) and once in reverse (evening-to-morning) order, separated by ≥29 days. Setting 12 schools. Participants Fourth-grade children. Main Outcome Measures For each meal: food-item variables – observed number, reported number, omission rate, intrusion rate, total inaccuracy; kilocalorie variables – observed, reported, correspondence rate, inflation ratio. Analysis General linear mixed-models. Results For each study, observed and reported numbers of items and kilocalories, and correspondence rate (reporting accuracy), were greater for lunch than breakfast; omission rate, intrusion rate, and inflation ratio (measures of reporting error) were greater for breakfast than lunch. Study 1 – for each meal over interviews, total inaccuracy decreased and correspondence rate increased. Study 2 – for each meal for boys for reverse and girls for forward order, omission rate was lower and correspondence rate was higher. Conclusions and Implications Breakfast was reported less accurately than lunch. Despite improvement over interviews (Study 1) and differences for order × sex (Study 2), reporting accuracy was low for breakfast and lunch. PMID:17493562

Impact of Community-Based Approach as Policy Tool: World Health Organization-Designated Safe Communities of Korea and Health Action Zones of the United Kingdom.

PubMed

Kang, Changhyun; Shin, Jihyung; Matthews, Bob

2016-02-01

The aim of this study is to ascertain and identify the effectiveness of area-based initiatives as a policy tool mediated by societal and individual factors in the five World Health Organization (WHO)-designated Safe Communities of Korea and the Health Action Zones of the United Kingdom (UK). The Korean National Hospital discharge in-depth injury survey from the Korea Centers for Disease Control and Prevention and causes of death statistics by the Statistics Korea were used for all analyses. The trend and changes in injury rate and mortality by external causes were compared among the five WHO-designated Safe Communities in Korea. The injury incident rates decreased at a greater level in the Safe Communities compared with the national average. Similar results were shown for the changes in unintentional injury incident rates. In comparison of changes in mortality rate by external causes between 2005 and 2011, the rate increase in Safe Communities was higher than the national average except for Jeju, where the mortality rate by external causes decreased. When the Healthy Action Zones of the UK and the WHO Safe Communities of Korea were examined, the outcomes were interpreted differently among the compared index, regions, and time periods. Therefore, qualitative outcomes, such as bringing the residents' attention to the safety of the communities and promoting participation and coordination of stakeholders, should also be considered as important impacts of the community-based initiatives.

A research model--forecasting incident rates from optimized safety program intervention strategies.

PubMed

Iyer, P S; Haight, J M; Del Castillo, E; Tink, B W; Hawkins, P W

2005-01-01

INTRODUCTION/PROBLEM: Property damage incidents, workplace injuries, and safety programs designed to prevent them, are expensive aspects of doing business in contemporary industry. The National Safety Council (2002) estimated that workplace injuries cost $146.6 billion per year. Because companies are resource limited, optimizing intervention strategies to decrease incidents with less costly programs can contribute to improved productivity. Systematic data collection methods were employed and the forecasting ability of a time-lag relationship between interventions and incident rates was studied using various statistical methods (an intervention is not expected to have an immediate nor infinitely lasting effect on the incident rate). As a follow up to the initial work, researchers developed two models designed to forecast incident rates. One is based on past incident rate performance and the other on the configuration and level of effort applied to the safety and health program. Researchers compared actual incident performance to the prediction capability of each model over 18 months in the forestry operations at an electricity distribution company and found the models to allow accurate prediction of incident rates. These models potentially have powerful implications as a business-planning tool for human resource allocation and for designing an optimized safety and health intervention program to minimize incidents. Depending on the mathematical relationship, one can determine what interventions, where and how much to apply them, and when to increase or reduce human resource input as determined by the forecasted performance.

Do consumer reports of health plan quality affect health plan selection?

PubMed Central

Spranca, M; Kanouse, D E; Elliott, M; Short, P F; Farley, D O; Hays, R D

2000-01-01

OBJECTIVE: To learn whether consumer reports of health plan quality can affect health plan selection. DATA SOURCES: A sample of 311 privately insured adults from Los Angeles County. STUDY DESIGN: The design was a fractional factorial experiment. Consumers reviewed materials on four hypothetical health plans and selected one. The health plans varied as to cost, coverage, type of plan, ability to keep one's doctor, and quality, as measured by the Consumer Assessment of Health Plans Study (CAHPS) survey. DATA ANALYSIS: We used multinomial logistic regression to model each consumer's choice among health plans. PRINCIPAL FINDINGS: In the absence of CAHPS information, 86 percent of consumers preferred plans that covered more services, even though they cost more. When CAHPS information was provided, consumers shifted to less expensive plans covering fewer services if CAHPS ratings identified those plans as higher quality (59 percent of consumers preferred plans covering more services). Consumer choices were unaffected when CAHPS ratings identified the more expensive plans covering more services as higher quality (89 percent of consumers preferred plans covering more services). CONCLUSIONS: This study establishes that, under certain realistic conditions, CAHPS ratings could affect consumer selection of health plans and ultimately contain costs. Other studies are needed to learn how to enhance exposure and use of CAHPS information in the real world as well as to identify other conditions in which CAHPS ratings could make a difference. PMID:11130805

Optimization of tribological performance of SiC embedded composite coating via Taguchi analysis approach

NASA Astrophysics Data System (ADS)

Maleque, M. A.; Bello, K. A.; Adebisi, A. A.; Akma, N.

2017-03-01

Tungsten inert gas (TIG) torch is one of the most recently used heat source for surface modification of engineering parts, giving similar results to the more expensive high power laser technique. In this study, ceramic-based embedded composite coating has been produced by precoated silicon carbide (SiC) powders on the AISI 4340 low alloy steel substrate using TIG welding torch process. A design of experiment based on Taguchi approach has been adopted to optimize the TIG cladding process parameters. The L9 orthogonal array and the signal-to-noise was used to study the effect of TIG welding parameters such as arc current, travelling speed, welding voltage and argon flow rate on tribological response behaviour (wear rate, surface roughness and wear track width). The objective of the study was to identify optimal design parameter that significantly minimizes each of the surface quality characteristics. The analysis of the experimental results revealed that the argon flow rate was found to be the most influential factor contributing to the minimum wear and surface roughness of the modified coating surface. On the other hand, the key factor in reducing wear scar is the welding voltage. Finally, a convenient and economical Taguchi approach used in this study was efficient to find out optimal factor settings for obtaining minimum wear rate, wear scar and surface roughness responses in TIG-coated surfaces.

Highlights of the high-temperature falling particle receiver project: 2012 - 2016

NASA Astrophysics Data System (ADS)

Ho, C. K.; Christian, J.; Yellowhair, J.; Jeter, S.; Golob, M.; Nguyen, C.; Repole, K.; Abdel-Khalik, S.; Siegel, N.; Al-Ansary, H.; El-Leathy, A.; Gobereit, B.

2017-06-01

A 1 MWt continuously recirculating falling particle receiver has been demonstrated at Sandia National Laboratories. Free-fall and obstructed-flow receiver designs were tested with particle mass flow rates of ˜1 - 7 kg/s and average irradiances up to 1,000 suns. Average particle outlet temperatures exceeded 700 °C for the free-fall tests and reached nearly 800 °C for the obstructed-flow tests, with peak particle temperatures exceeding 900 °C. High particle heating rates of ˜50 to 200 °C per meter of illuminated drop length were achieved for the free-fall tests with mass flow rates ranging from 1 - 7 kg/s and for average irradiances up to ˜ 700 kW/m2. Higher temperatures were achieved at the lower particle mass flow rates due to less shading. The obstructed-flow design yielded particle heating rates over 300 °C per meter of illuminated drop length for mass flow rates of 1 - 3 kg/s for irradiances up to ˜1,000 kW/m2. The thermal efficiency was determined to be ˜60 - 70% for the free-falling particle tests and up to ˜80% for the obstructed-flow tests. Challenges encountered during the tests include particle attrition and particle loss through the aperture, reduced particle mass flow rates at high temperatures due to slot aperture narrowing and increased friction, and deterioration of the obstructed-flow structures due to wear and oxidation. Computational models were validated using the test data and will be used in future studies to design receiver configurations that can increase the thermal efficiency.

Investigation of the hydrochlorination of SiCl4

NASA Technical Reports Server (NTRS)

Mui, J. Y. P.

1982-01-01

The hyrochlorination of SiC14 and m.g. silicon metal to produce SiHC13, was investigated. Reaction kinetic measurements were carried out to collect additional rate data at 525 C and 550 C. A theoretical study was carried out to provide a kinetic model and a rate equation for the hydrochlorination reaction. Results of this preliminary study show that the rate of formation of SiHC13 follows a pseudo first order kinetics. The rate constants were measured at three temperatures, 550 C, 500 C and 450 C, respectively. The activation energy was determined from the Arrhenius plot to give a value of 13.2 Kcal/mole. The design of a quartz reactor to measure reaction rates and equilibrium conversion of SiHC13 at reaction temperature up to 650 C was completed.

Methodological quality of behavioural weight loss studies: a systematic review

PubMed Central

Lemon, S. C.; Wang, M. L.; Haughton, C. F.; Estabrook, D. P.; Frisard, C. F.; Pagoto, S. L.

2018-01-01

Summary This systematic review assessed the methodological quality of behavioural weight loss intervention studies conducted among adults and associations between quality and statistically significant weight loss outcome, strength of intervention effectiveness and sample size. Searches for trials published between January, 2009 and December, 2014 were conducted using PUBMED, MEDLINE and PSYCINFO and identified ninety studies. Methodological quality indicators included study design, anthropometric measurement approach, sample size calculations, intent-to-treat (ITT) analysis, loss to follow-up rate, missing data strategy, sampling strategy, report of treatment receipt and report of intervention fidelity (mean = 6.3). Indicators most commonly utilized included randomized design (100%), objectively measured anthropometrics (96.7%), ITT analysis (86.7%) and reporting treatment adherence (76.7%). Most studies (62.2%) had a follow-up rate >75% and reported a loss to follow-up analytic strategy or minimal missing data (69.9%). Describing intervention fidelity (34.4%) and sampling from a known population (41.1%) were least common. Methodological quality was not associated with reporting a statistically significant result, effect size or sample size. This review found the published literature of behavioural weight loss trials to be of high quality for specific indicators, including study design and measurement. Identified for improvement include utilization of more rigorous statistical approaches to loss to follow up and better fidelity reporting. PMID:27071775

An internal pilot study for a randomized trial aimed at evaluating the effectiveness of iron interventions in children with non-anemic iron deficiency: the OptEC trial.

PubMed

Abdullah, Kawsari; Thorpe, Kevin E; Mamak, Eva; Maguire, Jonathon L; Birken, Catherine S; Fehlings, Darcy; Hanley, Anthony J; Macarthur, Colin; Zlotkin, Stanley H; Parkin, Patricia C

2015-07-14

The OptEC trial aims to evaluate the effectiveness of oral iron in young children with non-anemic iron deficiency (NAID). The initial sample size calculated for the OptEC trial ranged from 112-198 subjects. Given the uncertainty regarding the parameters used to calculate the sample, an internal pilot study was conducted. The objectives of this internal pilot study were to obtain reliable estimate of parameters (standard deviation and design factor) to recalculate the sample size and to assess the adherence rate and reasons for non-adherence in children enrolled in the pilot study. The first 30 subjects enrolled into the OptEC trial constituted the internal pilot study. The primary outcome of the OptEC trial is the Early Learning Composite (ELC). For estimation of the SD of the ELC, descriptive statistics of the 4 month follow-up ELC scores were assessed within each intervention group. The observed SD within each group was then pooled to obtain an estimated SD (S2) of the ELC. Correlation (ρ) between the ELC measured at baseline and follow-up was assessed. Recalculation of the sample size was performed using analysis of covariance (ANCOVA) method which uses the design factor (1- ρ(2)). Adherence rate was calculated using a parent reported rate of missed doses of the study intervention. The new estimate of the SD of the ELC was found to be 17.40 (S2). The design factor was (1- ρ2) = 0.21. Using a significance level of 5%, power of 80%, S2 = 17.40 and effect estimate (Δ) ranging from 6-8 points, the new sample size based on ANCOVA method ranged from 32-56 subjects (16-28 per group). Adherence ranged between 14% and 100% with 44% of the children having an adherence rate ≥ 86%. Information generated from our internal pilot study was used to update the design of the full and definitive trial, including recalculation of sample size, determination of the adequacy of adherence, and application of strategies to improve adherence. ClinicalTrials.gov Identifier: NCT01481766 (date of registration: November 22, 2011).