Multi-species attributes as the condition for adaptive sampling of rare species using two-stage sequential sampling with an auxiliary variable

USGS Publications Warehouse

Panahbehagh, B.; Smith, D.R.; Salehi, M.M.; Hornbach, D.J.; Brown, D.J.; Chan, F.; Marinova, D.; Anderssen, R.S.

2011-01-01

Assessing populations of rare species is challenging because of the large effort required to locate patches of occupied habitat and achieve precise estimates of density and abundance. The presence of a rare species has been shown to be correlated with presence or abundance of more common species. Thus, ecological community richness or abundance can be used to inform sampling of rare species. Adaptive sampling designs have been developed specifically for rare and clustered populations and have been applied to a wide range of rare species. However, adaptive sampling can be logistically challenging, in part, because variation in final sample size introduces uncertainty in survey planning. Two-stage sequential sampling (TSS), a recently developed design, allows for adaptive sampling, but avoids edge units and has an upper bound on final sample size. In this paper we present an extension of two-stage sequential sampling that incorporates an auxiliary variable (TSSAV), such as community attributes, as the condition for adaptive sampling. We develop a set of simulations to approximate sampling of endangered freshwater mussels to evaluate the performance of the TSSAV design. The performance measures that we are interested in are efficiency and probability of sampling a unit occupied by the rare species. Efficiency measures the precision of population estimate from the TSSAV design relative to a standard design, such as simple random sampling (SRS). The simulations indicate that the density and distribution of the auxiliary population is the most important determinant of the performance of the TSSAV design. Of the design factors, such as sample size, the fraction of the primary units sampled was most important. For the best scenarios, the odds of sampling the rare species was approximately 1.5 times higher for TSSAV compared to SRS and efficiency was as high as 2 (i.e., variance from TSSAV was half that of SRS). We have found that design performance, especially for adaptive designs, is often case-specific. Efficiency of adaptive designs is especially sensitive to spatial distribution. We recommend that simulations tailored to the application of interest are highly useful for evaluating designs in preparation for sampling rare and clustered populations.

Optimized FPGA Implementation of Multi-Rate FIR Filters Through Thread Decomposition

NASA Technical Reports Server (NTRS)

Zheng, Jason Xin; Nguyen, Kayla; He, Yutao

2010-01-01

Multirate (decimation/interpolation) filters are among the essential signal processing components in spaceborne instruments where Finite Impulse Response (FIR) filters are often used to minimize nonlinear group delay and finite-precision effects. Cascaded (multi-stage) designs of Multi-Rate FIR (MRFIR) filters are further used for large rate change ratio, in order to lower the required throughput while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original filter structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate. In this paper, an alternative representation and implementation technique, called TD-MRFIR (Thread Decomposition MRFIR), is presented. The basic idea is to decompose MRFIR into output computational threads, in contrast to a structural decomposition of the original filter as done in the polyphase decomposition. Each thread represents an instance of the finite convolution required to produce a single output of the MRFIR. The filter is thus viewed as a finite collection of concurrent threads. The technical details of TD-MRFIR will be explained, first showing its applicability to the implementation of downsampling, upsampling, and resampling FIR filters, and then describing a general strategy to optimally allocate the number of filter taps. A particular FPGA design of multi-stage TD-MRFIR for the L-band radar of NASA's SMAP (Soil Moisture Active Passive) instrument is demonstrated; and its implementation results in several targeted FPGA devices are summarized in terms of the functional (bit width, fixed-point error) and performance (time closure, resource usage, and power estimation) parameters.

Texas School Survey of Substance Abuse: Grades 7-12. 1992.

ERIC Educational Resources Information Center

Liu, Liang Y.; Fredlund, Eric V.

The 1992 Texas School Survey results for secondary students are based on data collected from a sample of 73,073 students in grades 7 through 12. Students were randomly selected from school districts throughout the state using a multi-stage probability design. The procedure ensured that students living in metropolitan and rural areas of Texas are…

[National Health and Nutrition Survey 2012: design and coverage].

PubMed

Romero-Martínez, Martín; Shamah-Levy, Teresa; Franco-Núñez, Aurora; Villalpando, Salvador; Cuevas-Nasu, Lucía; Gutiérrez, Juan Pablo; Rivera-Dommarco, Juan Ángel

2013-01-01

To describe the design and population coverage of the National Health and Nutrition Survey 2012 (NHNS 2012). The design of the NHNS 2012 is reported, as a probabilistic population based survey with a multi-stage and stratified sampling, as well as the sample inferential properties, the logistical procedures, and the obtained coverage. Household response rate for the NHNS 2012 was 87%, completing data from 50,528 households, where 96 031 individual interviews selected by age and 14,104 of ambulatory health services users were also obtained. The probabilistic design of the NHNS 2012 as well as its coverage allowed to generate inferences about health and nutrition conditions, health programs coverage, and access to health services. Because of their complex designs, all estimations from the NHNS 2012 must use the survey design: weights, primary sampling units, and stratus variables.

Efficient design of gain-flattened multi-pump Raman fiber amplifiers using least squares support vector regression

NASA Astrophysics Data System (ADS)

Chen, Jing; Qiu, Xiaojie; Yin, Cunyi; Jiang, Hao

2018-02-01

An efficient method to design the broadband gain-flattened Raman fiber amplifier with multiple pumps is proposed based on least squares support vector regression (LS-SVR). A multi-input multi-output LS-SVR model is introduced to replace the complicated solving process of the nonlinear coupled Raman amplification equation. The proposed approach contains two stages: offline training stage and online optimization stage. During the offline stage, the LS-SVR model is trained. Owing to the good generalization capability of LS-SVR, the net gain spectrum can be directly and accurately obtained when inputting any combination of the pump wavelength and power to the well-trained model. During the online stage, we incorporate the LS-SVR model into the particle swarm optimization algorithm to find the optimal pump configuration. The design results demonstrate that the proposed method greatly shortens the computation time and enhances the efficiency of the pump parameter optimization for Raman fiber amplifier design.

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.

Measured Effect of Sexual Activities, Alcohol Consumption, Smoking and Aggression on Health Risk of Students in Rural Communities in Ikenne, Nigeria

ERIC Educational Resources Information Center

Ezeokoli, Rita; Ofole, Ndidi M.

2015-01-01

This study examined the joint and relative contribution of sexual activities, alcohol consumption, smoking and aggression to the prediction of health risk of students in rural communities in Ogun State. Descriptive research design of correlational type was adopted. Multi-stage sampling Technique was used to draw 300 respondents from an…

Highly loaded multi-stage fan drive turbine-tandem blade configuration design

NASA Technical Reports Server (NTRS)

Evans, D. C.; Wolfmeyer, G. W.

1972-01-01

The results of the tandem blade configuration design study are reported. The three stage constant-inside-diameter turbine utilizes tandem blading in the stage two and stage three vanes and in the stage three blades. All other bladerows use plain blades. Blading detailed design is discussed, and design data are summarized. Steady-state stresses and vibratory behavior are discussed, and the results of the mechanical design analysis are presented.

Study of CFB Simulation Model with Coincidence at Multi-Working Condition

NASA Astrophysics Data System (ADS)

Wang, Z.; He, F.; Yang, Z. W.; Li, Z.; Ni, W. D.

A circulating fluidized bed (CFB) two-stage simulation model was developed. To realize the model results coincident with the design value or real operation value at specified multi-working conditions and with capability of real-time calculation, only the main key processes were taken into account and the dominant factors were further abstracted out of these key processes. The simulation results showed a sound accordance at multi-working conditions, and confirmed the advantage of the two-stage model over the original single-stage simulation model. The combustion-support effect of secondary air was investigated using the two-stage model. This model provides a solid platform for investigating the pant-leg structured CFB furnace, which is now under design for a supercritical power plant.

Evaluation of a multi-arm multi-stage Bayesian design for phase II drug selection trials - an example in hemato-oncology.

PubMed

Jacob, Louis; Uvarova, Maria; Boulet, Sandrine; Begaj, Inva; Chevret, Sylvie

2016-06-02

Multi-Arm Multi-Stage designs aim at comparing several new treatments to a common reference, in order to select or drop any treatment arm to move forward when such evidence already exists based on interim analyses. We redesigned a Bayesian adaptive design initially proposed for dose-finding, focusing our interest in the comparison of multiple experimental drugs to a control on a binary criterion measure. We redesigned a phase II clinical trial that randomly allocates patients across three (one control and two experimental) treatment arms to assess dropping decision rules. We were interested in dropping any arm due to futility, either based on historical control rate (first rule) or comparison across arms (second rule), and in stopping experimental arm due to its ability to reach a sufficient response rate (third rule), using the difference of response probabilities in Bayes binomial trials between the treated and control as a measure of treatment benefit. Simulations were then conducted to investigate the decision operating characteristics under a variety of plausible scenarios, as a function of the decision thresholds. Our findings suggest that one experimental treatment was less efficient than the control and could have been dropped from the trial based on a sample of approximately 20 instead of 40 patients. In the simulation study, stopping decisions were reached sooner for the first rule than for the second rule, with close mean estimates of response rates and small bias. According to the decision threshold, the mean sample size to detect the required 0.15 absolute benefit ranged from 63 to 70 (rule 3) with false negative rates of less than 2 % (rule 1) up to 6 % (rule 2). In contrast, detecting a 0.15 inferiority in response rates required a sample size ranging on average from 23 to 35 (rules 1 and 2, respectively) with a false positive rate ranging from 3.6 to 0.6 % (rule 3). Adaptive trial design is a good way to improve clinical trials. It allows removing ineffective drugs and reducing the trial sample size, while maintaining unbiased estimates. Decision thresholds can be set according to predefined fixed error decision rates. ClinicalTrials.gov Identifier: NCT01342692 .

Multidisciplinary Multiobjective Optimal Design for Turbomachinery Using Evolutionary Algorithm

NASA Technical Reports Server (NTRS)

2005-01-01

This report summarizes Dr. Lian s efforts toward developing a robust and efficient tool for multidisciplinary and multi-objective optimal design for turbomachinery using evolutionary algorithms. This work consisted of two stages. The first stage (from July 2003 to June 2004) Dr. Lian focused on building essential capabilities required for the project. More specifically, Dr. Lian worked on two subjects: an enhanced genetic algorithm (GA) and an integrated optimization system with a GA and a surrogate model. The second stage (from July 2004 to February 2005) Dr. Lian formulated aerodynamic optimization and structural optimization into a multi-objective optimization problem and performed multidisciplinary and multi-objective optimizations on a transonic compressor blade based on the proposed model. Dr. Lian s numerical results showed that the proposed approach can effectively reduce the blade weight and increase the stage pressure ratio in an efficient manner. In addition, the new design was structurally safer than the original design. Five conference papers and three journal papers were published on this topic by Dr. Lian.

Experimental light scattering by small particles: system design and calibration

NASA Astrophysics Data System (ADS)

Maconi, Göran; Kassamakov, Ivan; Penttilä, Antti; Gritsevich, Maria; Hæggström, Edward; Muinonen, Karri

2017-06-01

We describe a setup for precise multi-angular measurements of light scattered by mm- to μm-sized samples. We present a calibration procedure that ensures accurate measurements. Calibration is done using a spherical sample (d = 5 mm, n = 1.517) fixed on a static holder. The ultimate goal of the project is to allow accurate multi-wavelength measurements (the full Mueller matrix) of single-particle samples which are levitated ultrasonically. The system comprises a tunable multimode Argon-krypton laser, with 12 wavelengths ranging from 465 to 676 nm, a linear polarizer, a reference photomultiplier tube (PMT) monitoring beam intensity, and several PMT:s mounted radially towards the sample at an adjustable radius. The current 150 mm radius allows measuring all azimuthal angles except for ±4° around the backward scattering direction. The measurement angle is controlled by a motor-driven rotational stage with an accuracy of 15'.

Accelerating clinical development of HIV vaccine strategies: methodological challenges and considerations in constructing an optimised multi-arm phase I/II trial design.

PubMed

Richert, Laura; Doussau, Adélaïde; Lelièvre, Jean-Daniel; Arnold, Vincent; Rieux, Véronique; Bouakane, Amel; Lévy, Yves; Chêne, Geneviève; Thiébaut, Rodolphe

2014-02-26

Many candidate vaccine strategies against human immunodeficiency virus (HIV) infection are under study, but their clinical development is lengthy and iterative. To accelerate HIV vaccine development optimised trial designs are needed. We propose a randomised multi-arm phase I/II design for early stage development of several vaccine strategies, aiming at rapidly discarding those that are unsafe or non-immunogenic. We explored early stage designs to evaluate both the safety and the immunogenicity of four heterologous prime-boost HIV vaccine strategies in parallel. One of the vaccines used as a prime and boost in the different strategies (vaccine 1) has yet to be tested in humans, thus requiring a phase I safety evaluation. However, its toxicity risk is considered minimal based on data from similar vaccines. We newly adapted a randomised phase II trial by integrating an early safety decision rule, emulating that of a phase I study. We evaluated the operating characteristics of the proposed design in simulation studies with either a fixed-sample frequentist or a continuous Bayesian safety decision rule and projected timelines for the trial. We propose a randomised four-arm phase I/II design with two independent binary endpoints for safety and immunogenicity. Immunogenicity evaluation at trial end is based on a single-stage Fleming design per arm, comparing the observed proportion of responders in an immunogenicity screening assay to an unacceptably low proportion, without direct comparisons between arms. Randomisation limits heterogeneity in volunteer characteristics between arms. To avoid exposure of additional participants to an unsafe vaccine during the vaccine boost phase, an early safety decision rule is imposed on the arm starting with vaccine 1 injections. In simulations of the design with either decision rule, the risks of erroneous conclusions were controlled <15%. Flexibility in trial conduct is greater with the continuous Bayesian rule. A 12-month gain in timelines is expected by this optimised design. Other existing designs such as bivariate or seamless phase I/II designs did not offer a clear-cut alternative. By combining phase I and phase II evaluations in a multi-arm trial, the proposed optimised design allows for accelerating early stage clinical development of HIV vaccine strategies.

Using public control genotype data to increase power and decrease cost of case-control genetic association studies.

PubMed

Ho, Lindsey A; Lange, Ethan M

2010-12-01

Genome-wide association (GWA) studies are a powerful approach for identifying novel genetic risk factors associated with human disease. A GWA study typically requires the inclusion of thousands of samples to have sufficient statistical power to detect single nucleotide polymorphisms that are associated with only modest increases in risk of disease given the heavy burden of a multiple test correction that is necessary to maintain valid statistical tests. Low statistical power and the high financial cost of performing a GWA study remains prohibitive for many scientific investigators anxious to perform such a study using their own samples. A number of remedies have been suggested to increase statistical power and decrease cost, including the utilization of free publicly available genotype data and multi-stage genotyping designs. Herein, we compare the statistical power and relative costs of alternative association study designs that use cases and screened controls to study designs that are based only on, or additionally include, free public control genotype data. We describe a novel replication-based two-stage study design, which uses free public control genotype data in the first stage and follow-up genotype data on case-matched controls in the second stage that preserves many of the advantages inherent when using only an epidemiologically matched set of controls. Specifically, we show that our proposed two-stage design can substantially increase statistical power and decrease cost of performing a GWA study while controlling the type-I error rate that can be inflated when using public controls due to differences in ancestry and batch genotype effects.

Patient-centred screening for primary immunodeficiency: a multi-stage diagnostic protocol designed for non-immunologists

PubMed Central

de Vries, E

2006-01-01

Efficient early identification of primary immunodeficiency disease (PID) is important for prognosis, but is not an easy task for non-immunologists. The Clinical Working Party of the European Society for Immunodeficiencies (ESID) has composed a multi-stage diagnostic protocol that is based on expert opinion, in order to increase the awareness of PID among doctors working in different fields. The protocol starts from the clinical presentation of the patient; immunological skills are not needed for its use. The multi-stage design allows cost-effective screening for PID within the large pool of potential cases in all hospitals in the early phases, while more expensive tests are reserved for definitive classification in collaboration with an immunologist at a later stage. Although many PIDs present in childhood, others may present at any age. The protocols presented here are therefore aimed at both adult physicians and paediatricians. While designed for use throughout Europe, there will be national differences which may make modification of this generic algorithm necessary. PMID:16879238

Patient-centred screening for primary immunodeficiency, a multi-stage diagnostic protocol designed for non-immunologists: 2011 update

PubMed Central

de Vries, E

2012-01-01

Members of the European Society for Immunodeficiencies (ESID) and other colleagues have updated the multi-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs). The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage. PMID:22132890

Performance assessment and microbial diversity of two pilot scale multi-stage sub-surface flow constructed wetland systems.

PubMed

Babatunde, A O; Miranda-CasoLuengo, Raul; Imtiaz, Mehreen; Zhao, Y Q; Meijer, Wim G

2016-08-01

This study assessed the performance and diversity of microbial communities in multi-stage sub-surface flow constructed wetland systems (CWs). Our aim was to assess the impact of configuration on treatment performance and microbial diversity in the systems. Results indicate that at loading rates up to 100gBOD5/(m(2)·day), similar treatment performances can be achieved using either a 3 or 4 stage configuration. In the case of phosphorus (P), the impact of configuration was less obvious and a minimum of 80% P removal can be expected for loadings up to 10gP/(m(2)·day) based on the performance results obtained within the first 16months of operation. Microbial analysis showed an increased bacterial diversity in stage four compared to the first stage. These results indicate that the design and configuration of multi-stage constructed wetland systems may have an impact on the treatment performance and the composition of the microbial community in the systems, and such knowledge can be used to improve their design and performance. Copyright © 2016. Published by Elsevier B.V.

[Design of the National Surveillance of Nutritional Indicators (MONIN), Peru 2007-2010].

PubMed

Campos-Sánchez, Miguel; Ricaldi-Sueldo, Rita; Miranda-Cuadros, Marianella

2011-06-01

To describe the design and methods of the national surveillance of nutritional indicators (MONIN) 2007-2010, carried out by INS/CENAN. MONIN was designed as a continuous (repeated cross-sectional) survey, with stratified multi-stage random sampling, considering the universe as all under five children and pregnant women residing in Peru, divided into 5 geographical strata and 6 trimesters (randomly permuted weeks, about 78% of the time between November 19, 2007 and April 2, 2010). The total sample was 3,827 children in 361 completed clusters. The dropout rate was 8.4% in clusters, 1.8% in houses, and 13.2% in households. Dropout was also 4.2, 13.3, 21.2, 55% and 29% in anthropometry, hemoglobin, food intake, retinol and ioduria measurements, respectively. The MONIN design is feasible and useful for the estimation of indicators of childhood malnutrition.

A multi-stage oil-water-separating process design for the sea oil spill recovery robot

NASA Astrophysics Data System (ADS)

Zhang, Min-ge; Wu, Jian-guo; Lin, Xinhua; Wang, Xiao-ming

2018-03-01

Oil spill have the most common pollution to the marine ecological environment. In the late stage of physical method recovery, because of the thin oil and the strong sea breeze, the recovery vessels has low efficiency and high energy consumption. This paper develops a multi-stage oil-water-separating process carried by the sea oil spill recovery robot in severe conditions. This design consists of three separation process, among which both the first and third process adopt corrugated sheets horizontal oil-water separator, while the second is hydraulic rotary breaker. This design also equiptment with rectifier and cyclone separator and other important components. This process has high flexibility and high recovery efficiency. The implement effect is significant.

Assessment of computer-related health problems among post-graduate nursing students.

PubMed

Khan, Shaheen Akhtar; Sharma, Veena

2013-01-01

The study was conducted to assess computer-related health problems among post-graduate nursing students and to develop a Self Instructional Module for prevention of computer-related health problems in a selected university situated in Delhi. A descriptive survey with co-relational design was adopted. A total of 97 samples were selected from different faculties of Jamia Hamdard by multi stage sampling with systematic random sampling technique. Among post-graduate students, majority of sample subjects had average compliance with computer-related ergonomics principles. As regards computer related health problems, majority of post graduate students had moderate computer-related health problems, Self Instructional Module developed for prevention of computer-related health problems was found to be acceptable by the post-graduate students.

An adaptive two-stage sequential design for sampling rare and clustered populations

USGS Publications Warehouse

Brown, J.A.; Salehi, M.M.; Moradi, M.; Bell, G.; Smith, D.R.

2008-01-01

How to design an efficient large-area survey continues to be an interesting question for ecologists. In sampling large areas, as is common in environmental studies, adaptive sampling can be efficient because it ensures survey effort is targeted to subareas of high interest. In two-stage sampling, higher density primary sample units are usually of more interest than lower density primary units when populations are rare and clustered. Two-stage sequential sampling has been suggested as a method for allocating second stage sample effort among primary units. Here, we suggest a modification: adaptive two-stage sequential sampling. In this method, the adaptive part of the allocation process means the design is more flexible in how much extra effort can be directed to higher-abundance primary units. We discuss how best to design an adaptive two-stage sequential sample. ?? 2008 The Society of Population Ecology and Springer.

Multi-Stage Hybrid Rocket Conceptual Design for Micro-Satellites Launch using Genetic Algorithm

NASA Astrophysics Data System (ADS)

Kitagawa, Yosuke; Kitagawa, Koki; Nakamiya, Masaki; Kanazaki, Masahiro; Shimada, Toru

The multi-objective genetic algorithm (MOGA) is applied to the multi-disciplinary conceptual design problem for a three-stage launch vehicle (LV) with a hybrid rocket engine (HRE). MOGA is an optimization tool used for multi-objective problems. The parallel coordinate plot (PCP), which is a data mining method, is employed in the post-process in MOGA for design knowledge discovery. A rocket that can deliver observing micro-satellites to the sun-synchronous orbit (SSO) is designed. It consists of an oxidizer tank containing liquid oxidizer, a combustion chamber containing solid fuel, a pressurizing tank and a nozzle. The objective functions considered in this study are to minimize the total mass of the rocket and to maximize the ratio of the payload mass to the total mass. To calculate the thrust and the engine size, the regression rate is estimated based on an empirical model for a paraffin (FT-0070) propellant. Several non-dominated solutions are obtained using MOGA, and design knowledge is discovered for the present hybrid rocket design problem using a PCP analysis. As a result, substantial knowledge on the design of an LV with an HRE is obtained for use in space transportation.

Low-cost cryo-light microscopy stage fabrication for correlated light/electron microscopy.

PubMed

Carlson, David B; Evans, James E

2011-06-05

The coupling of cryo-light microscopy (cryo-LM) and cryo-electron microscopy (cryo-EM) poses a number of advantages for understanding cellular dynamics and ultrastructure. First, cells can be imaged in a near native environment for both techniques. Second, due to the vitrification process, samples are preserved by rapid physical immobilization rather than slow chemical fixation. Third, imaging the same sample with both cryo-LM and cryo-EM provides correlation of data from a single cell, rather than a comparison of "representative samples". While these benefits are well known from prior studies, the widespread use of correlative cryo-LM and cryo-EM remains limited due to the expense and complexity of buying or building a suitable cryogenic light microscopy stage. Here we demonstrate the assembly, and use of an inexpensive cryogenic stage that can be fabricated in any lab for less than $40 with parts found at local hardware and grocery stores. This cryo-LM stage is designed for use with reflected light microscopes that are fitted with long working distance air objectives. For correlative cryo-LM and cryo-EM studies, we adapt the use of carbon coated standard 3-mm cryo-EM grids as specimen supports. After adsorbing the sample to the grid, previously established protocols for vitrifying the sample and transferring/handling the grid are followed to permit multi-technique imaging. As a result, this setup allows any laboratory with a reflected light microscope to have access to direct correlative imaging of frozen hydrated samples.

Fashion sketch design by interactive genetic algorithms

NASA Astrophysics Data System (ADS)

Mok, P. Y.; Wang, X. X.; Xu, J.; Kwok, Y. L.

2012-11-01

Computer aided design is vitally important for the modern industry, particularly for the creative industry. Fashion industry faced intensive challenges to shorten the product development process. In this paper, a methodology is proposed for sketch design based on interactive genetic algorithms. The sketch design system consists of a sketch design model, a database and a multi-stage sketch design engine. First, a sketch design model is developed based on the knowledge of fashion design to describe fashion product characteristics by using parameters. Second, a database is built based on the proposed sketch design model to define general style elements. Third, a multi-stage sketch design engine is used to construct the design. Moreover, an interactive genetic algorithm (IGA) is used to accelerate the sketch design process. The experimental results have demonstrated that the proposed method is effective in helping laypersons achieve satisfied fashion design sketches.

A novel modular ANN architecture for efficient monitoring of gases/odours in real-time

NASA Astrophysics Data System (ADS)

Mishra, A.; Rajput, N. S.

2018-04-01

Data pre-processing is tremendously used for enhanced classification of gases. However, it suppresses the concentration variances of different gas samples. A classical solution of using single artificial neural network (ANN) architecture is also inefficient and renders degraded quantification. In this paper, a novel modular ANN design has been proposed to provide an efficient and scalable solution in real–time. Here, two separate ANN blocks viz. classifier block and quantifier block have been used to provide efficient and scalable gas monitoring in real—time. The classifier ANN consists of two stages. In the first stage, the Net 1-NDSRT has been trained to transform raw sensor responses into corresponding virtual multi-sensor responses using normalized difference sensor response transformation (NDSRT). These responses have been fed to the second stage (i.e., Net 2-classifier ). The Net 2-classifier has been trained to classify various gas samples to their respective class. Further, the quantifier block has parallel ANN modules, multiplexed to quantify each gas. Therefore, the classifier ANN decides class and quantifier ANN decides the exact quantity of the gas/odor present in the respective sample of that class.

Multi-Stage System for Automatic Target Recognition

NASA Technical Reports Server (NTRS)

Chao, Tien-Hsin; Lu, Thomas T.; Ye, David; Edens, Weston; Johnson, Oliver

2010-01-01

A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feedforward back-propagation neural network (NN) is then trained to classify each feature vector and to remove false positives. The system parameter optimizations process has been developed to adapt to various targets and datasets. The objective was to design an efficient computer vision system that can learn to detect multiple targets in large images with unknown backgrounds. Because the target size is small relative to the image size in this problem, there are many regions of the image that could potentially contain the target. A cursory analysis of every region can be computationally efficient, but may yield too many false positives. On the other hand, a detailed analysis of every region can yield better results, but may be computationally inefficient. The multi-stage ATR system was designed to achieve an optimal balance between accuracy and computational efficiency by incorporating both models. The detection stage first identifies potential ROIs where the target may be present by performing a fast Fourier domain OT-MACH filter-based correlation. Because threshold for this stage is chosen with the goal of detecting all true positives, a number of false positives are also detected as ROIs. The verification stage then transforms the regions of interest into feature space, and eliminates false positives using an artificial neural network classifier. The multi-stage system allows tuning the detection sensitivity and the identification specificity individually in each stage. It is easier to achieve optimized ATR operation based on its specific goal. The test results show that the system was successful in substantially reducing the false positive rate when tested on a sonar and video image datasets.

A randomized controlled trial of acupuncture and moxibustion to treat Bell's palsy according to different stages: design and protocol.

PubMed

Chen, Xiaoqin; Li, Ying; Zheng, Hui; Hu, Kaming; Zhang, Hongxing; Zhao, Ling; Li, Yan; Liu, Lian; Mang, Lingling; Yu, Shuyuan

2009-07-01

Acupuncture to treat Bell's palsy is one of the most commonly used methods in China. There are a variety of acupuncture treatment options to treat Bell's palsy in clinical practice. Since Bell's palsy has three different path-stages (acute stage, resting stage and restoration stage), so whether acupuncture is effective in the different path-stages and which acupuncture treatment is the best method are major issues in acupuncture clinical trials about Bell's palsy. In this article, we report the design and protocol of a large sample multi-center randomized controlled trial to treat Bell's palsy with acupuncture. There are five acupuncture groups, with four according to different path-stages and one not. In total, 900 patients with Bell's palsy are enrolled in this study. These patients are randomly assigned to receive one of the following four treatment groups according to different path-stages, i.e. 1) staging acupuncture group, 2) staging acupuncture and moxibustion group, 3) staging electro-acupuncture group, 4) staging acupuncture along yangming musculature group or non-staging acupuncture control group. The outcome measurements in this trial are the effect comparison achieved among these five groups in terms of House-Brackmann scale (Global Score and Regional Score), Facial Disability Index scale, Classification scale of Facial Paralysis, and WHOQOL-BREF scale before randomization (baseline phase) and after randomization. The result of this trial will certify the efficacy of using staging acupuncture and moxibustion to treat Bell's palsy, and to approach a best acupuncture treatment among these five different methods for treating Bell's palsy.

National accident sampling system sample design, phases 2 and 3 : executive summary

DOT National Transportation Integrated Search

1979-11-01

This report describes the Phase 2 and 3 sample design for the : National Accident Sampling System (NASS). It recommends a procedure : for the first-stage selection of Primary Sampling Units (PSU's) and : the second-stage design for the selection of a...

Integration of multi-objective structural optimization into cementless hip prosthesis design: Improved Austin-Moore model.

PubMed

Kharmanda, G

2016-11-01

A new strategy of multi-objective structural optimization is integrated into Austin-Moore prosthesis in order to improve its performance. The new resulting model is so-called Improved Austin-Moore. The topology optimization is considered as a conceptual design stage to sketch several kinds of hollow stems according to the daily loading cases. The shape optimization presents the detailed design stage considering several objectives. Here, A new multiplicative formulation is proposed as a performance scale in order to define the best compromise between several requirements. Numerical applications on 2D and 3D problems are carried out to show the advantages of the proposed model.

Selecting promising treatments in randomized Phase II cancer trials with an active control.

PubMed

Cheung, Ying Kuen

2009-01-01

The primary objective of Phase II cancer trials is to evaluate the potential efficacy of a new regimen in terms of its antitumor activity in a given type of cancer. Due to advances in oncology therapeutics and heterogeneity in the patient population, such evaluation can be interpreted objectively only in the presence of a prospective control group of an active standard treatment. This paper deals with the design problem of Phase II selection trials in which several experimental regimens are compared to an active control, with an objective to identify an experimental arm that is more effective than the control or to declare futility if no such treatment exists. Conducting a multi-arm randomized selection trial is a useful strategy to prioritize experimental treatments for further testing when many candidates are available, but the sample size required in such a trial with an active control could raise feasibility concerns. In this study, we extend the sequential probability ratio test for normal observations to the multi-arm selection setting. The proposed methods, allowing frequent interim monitoring, offer high likelihood of early trial termination, and as such enhance enrollment feasibility. The termination and selection criteria have closed form solutions and are easy to compute with respect to any given set of error constraints. The proposed methods are applied to design a selection trial in which combinations of sorafenib and erlotinib are compared to a control group in patients with non-small-cell lung cancer using a continuous endpoint of change in tumor size. The operating characteristics of the proposed methods are compared to that of a single-stage design via simulations: The sample size requirement is reduced substantially and is feasible at an early stage of drug development.

A Comprehensive Structural Dynamic Analysis Approach for Multi Mission Earth Entry Vehicle (MMEEV) Development

NASA Technical Reports Server (NTRS)

Perino, Scott; Bayandor, Javid; Siddens, Aaron

2012-01-01

The anticipated NASA Mars Sample Return Mission (MSR) requires a simple and reliable method in which to return collected Martian samples back to earth for scientific analysis. The Multi-Mission Earth Entry Vehicle (MMEEV) is NASA's proposed solution to this MSR requirement. Key aspects of the MMEEV are its reliable and passive operation, energy absorbing foam-composite structure, and modular impact sphere (IS) design. To aid in the development of an EEV design that can be modified for various missions requirements, two fully parametric finite element models were developed. The first model was developed in an explicit finite element code and was designed to evaluate the impact response of the vehicle and payload during the final stage of the vehicle's return to earth. The second model was developed in an explicit code and was designed to evaluate the static and dynamic structural response of the vehicle during launch and reentry. In contrast to most other FE models, built through a Graphical User Interface (GUI) pre-processor, the current model was developed using a coding technique that allows the analyst to quickly change nearly all aspects of the model including: geometric dimensions, material properties, load and boundary conditions, mesh properties, and analysis controls. Using the developed design tool, a full range of proposed designs can quickly be analyzed numerically and thus the design trade space for the EEV can be fully understood. An engineer can then quickly reach the best design for a specific mission and also adapt and optimize the general design for different missions.

Numerically stable algorithm for combining census and sample estimates with the multivariate composite estimator

Treesearch

R. L. Czaplewski

2009-01-01

The minimum variance multivariate composite estimator is a relatively simple sequential estimator for complex sampling designs (Czaplewski 2009). Such designs combine a probability sample of expensive field data with multiple censuses and/or samples of relatively inexpensive multi-sensor, multi-resolution remotely sensed data. Unfortunately, the multivariate composite...

Preliminary design trade-offs for a multi-mission stored cryogen cooler

NASA Technical Reports Server (NTRS)

Sherman, A.

1978-01-01

Preliminary design studies were performed for a multi-mission solid cryogen cooler having a wide range of application for both the shuttle sortie and free flyer missions. This multi-mission cooler (MMC) is designed to be utilized with various solid cryogens to meet a wide range of instrument cooling from 10 K (with solid hydrogen) to 90 K. The baseline cooler utilizes two stages of solid cryogen and incorporates an optional, higher temperature third stage which is cooled by either a passive radiator or a thermoelectric cooler. The MMC has an interface which can accommodate a wide variety of instrument configurations. A shrink fit adapter is incorporated which allows a drop-in instrument integration. The baseline design provides cooling of approximately 1 watt over a 60 to 100 K temperature range and about 0.5 watts from 15 to 60 K for a one year lifetime. For low cooling loads and with use of the optional radiator shield, cooling lifetimes as great as 8 years are predicted.

Multi-stage fuel cell system method and apparatus

DOEpatents

George, Thomas J.; Smith, William C.

2000-01-01

A high efficiency, multi-stage fuel cell system method and apparatus is provided. The fuel cell system is comprised of multiple fuel cell stages, whereby the temperatures of the fuel and oxidant gas streams and the percentage of fuel consumed in each stage are controlled to optimize fuel cell system efficiency. The stages are connected in a serial, flow-through arrangement such that the oxidant gas and fuel gas flowing through an upstream stage is conducted directly into the next adjacent downstream stage. The fuel cell stages are further arranged such that unspent fuel and oxidant laden gases too hot to continue within an upstream stage because of material constraints are conducted into a subsequent downstream stage which comprises a similar cell configuration, however, which is constructed from materials having a higher heat tolerance and designed to meet higher thermal demands. In addition, fuel is underutilized in each stage, resulting in a higher overall fuel cell system efficiency.

A Bayesian multi-stage cost-effectiveness design for animal studies in stroke research

PubMed Central

Cai, Chunyan; Ning, Jing; Huang, Xuelin

2017-01-01

Much progress has been made in the area of adaptive designs for clinical trials. However, little has been done regarding adaptive designs to identify optimal treatment strategies in animal studies. Motivated by an animal study of a novel strategy for treating strokes, we propose a Bayesian multi-stage cost-effectiveness design to simultaneously identify the optimal dose and determine the therapeutic treatment window for administrating the experimental agent. We consider a non-monotonic pattern for the dose-schedule-efficacy relationship and develop an adaptive shrinkage algorithm to assign more cohorts to admissible strategies. We conduct simulation studies to evaluate the performance of the proposed design by comparing it with two standard designs. These simulation studies show that the proposed design yields a significantly higher probability of selecting the optimal strategy, while it is generally more efficient and practical in terms of resource usage. PMID:27405325

How quantitative measures unravel design principles in multi-stage phosphorylation cascades.

PubMed

Frey, Simone; Millat, Thomas; Hohmann, Stefan; Wolkenhauer, Olaf

2008-09-07

We investigate design principles of linear multi-stage phosphorylation cascades by using quantitative measures for signaling time, signal duration and signal amplitude. We compare alternative pathway structures by varying the number of phosphorylations and the length of the cascade. We show that a model for a weakly activated pathway does not reflect the biological context well, unless it is restricted to certain parameter combinations. Focusing therefore on a more general model, we compare alternative structures with respect to a multivariate optimization criterion. We test the hypothesis that the structure of a linear multi-stage phosphorylation cascade is the result of an optimization process aiming for a fast response, defined by the minimum of the product of signaling time and signal duration. It is then shown that certain pathway structures minimize this criterion. Several popular models of MAPK cascades form the basis of our study. These models represent different levels of approximation, which we compare and discuss with respect to the quantitative measures.

Estimation of winter wheat canopy nitrogen density at different growth stages based on Multi-LUT approach

NASA Astrophysics Data System (ADS)

Li, Zhenhai; Li, Na; Li, Zhenhong; Wang, Jianwen; Liu, Chang

2017-10-01

Rapid real-time monitoring of wheat nitrogen (N) status is crucial for precision N management during wheat growth. In this study, Multi Lookup Table (Multi-LUT) approach based on the N-PROSAIL model parameters setting at different growth stages was constructed to estimating canopy N density (CND) in winter wheat. The results showed that the estimated CND was in line with with measured CND, with the determination coefficient (R2) and the corresponding root mean square error (RMSE) values of 0.80 and 1.16 g m-2, respectively. Time-consuming of one sample estimation was only 6 ms under the test machine with CPU configuration of Intel(R) Core(TM) i5-2430 @2.40GHz quad-core. These results confirmed the potential of using Multi-LUT approach for CND retrieval in winter wheat at different growth stages and under variables climatic conditions.

CALiPER Report 20.3: Robustness of LED PAR38 Lamps

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

Poplawski, Michael E.; Royer, Michael P.; Brown, Charles C.

2014-12-01

Three samples of 40 of the Series 20 PAR38 lamps underwent multi-stress testing, whereby samples were subjected to increasing levels of simultaneous thermal, humidity, electrical, and vibrational stress. The results do not explicitly predict expected lifetime or reliability, but they can be compared with one another, as well as with benchmark conventional products, to assess the relative robustness of the product designs. On average, the 32 LED lamp models tested were substantially more robust than the conventional benchmark lamps. As with other performance attributes, however, there was great variability in the robustness and design maturity of the LED lamps. Severalmore » LED lamp samples failed within the first one or two levels of the ten-level stress plan, while all three samples of some lamp models completed all ten levels. One potential area of improvement is design maturity, given that more than 25% of the lamp models demonstrated a difference in failure level for the three samples that was greater than or equal to the maximum for the benchmarks. At the same time, the fact that nearly 75% of the lamp models exhibited better design maturity than the benchmarks is noteworthy, given the relative stage of development for the technology.« less

Multi-Scale/Multi-Functional Probabilistic Composite Fatigue

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

2008-01-01

A multi-level (multi-scale/multi-functional) evaluation is demonstrated by applying it to three different sample problems. These problems include the probabilistic evaluation of a space shuttle main engine blade, an engine rotor and an aircraft wing. The results demonstrate that the blade will fail at the highest probability path, the engine two-stage rotor will fail by fracture at the rim and the aircraft wing will fail at 109 fatigue cycles with a probability of 0.9967.

Automatic sleep staging using multi-dimensional feature extraction and multi-kernel fuzzy support vector machine.

PubMed

Zhang, Yanjun; Zhang, Xiangmin; Liu, Wenhui; Luo, Yuxi; Yu, Enjia; Zou, Keju; Liu, Xiaoliang

2014-01-01

This paper employed the clinical Polysomnographic (PSG) data, mainly including all-night Electroencephalogram (EEG), Electrooculogram (EOG) and Electromyogram (EMG) signals of subjects, and adopted the American Academy of Sleep Medicine (AASM) clinical staging manual as standards to realize automatic sleep staging. Authors extracted eighteen different features of EEG, EOG and EMG in time domains and frequency domains to construct the vectors according to the existing literatures as well as clinical experience. By adopting sleep samples self-learning, the linear combination of weights and parameters of multiple kernels of the fuzzy support vector machine (FSVM) were learned and the multi-kernel FSVM (MK-FSVM) was constructed. The overall agreement between the experts' scores and the results presented was 82.53%. Compared with previous results, the accuracy of N1 was improved to some extent while the accuracies of other stages were approximate, which well reflected the sleep structure. The staging algorithm proposed in this paper is transparent, and worth further investigation.

Multi-point objective-oriented sequential sampling strategy for constrained robust design

NASA Astrophysics Data System (ADS)

Zhu, Ping; Zhang, Siliang; Chen, Wei

2015-03-01

Metamodelling techniques are widely used to approximate system responses of expensive simulation models. In association with the use of metamodels, objective-oriented sequential sampling methods have been demonstrated to be effective in balancing the need for searching an optimal solution versus reducing the metamodelling uncertainty. However, existing infilling criteria are developed for deterministic problems and restricted to one sampling point in one iteration. To exploit the use of multiple samples and identify the true robust solution in fewer iterations, a multi-point objective-oriented sequential sampling strategy is proposed for constrained robust design problems. In this article, earlier development of objective-oriented sequential sampling strategy for unconstrained robust design is first extended to constrained problems. Next, a double-loop multi-point sequential sampling strategy is developed. The proposed methods are validated using two mathematical examples followed by a highly nonlinear automotive crashworthiness design example. The results show that the proposed method can mitigate the effect of both metamodelling uncertainty and design uncertainty, and identify the robust design solution more efficiently than the single-point sequential sampling approach.

Towards Optimal Design of Cancer Nanomedicines: Multi-stage Nanoparticles for the Treatment of Solid Tumors.

PubMed

Stylianopoulos, Triantafyllos; Economides, Eva-Athena; Baish, James W; Fukumura, Dai; Jain, Rakesh K

2015-09-01

Conventional drug delivery systems for solid tumors are composed of a nano-carrier that releases its therapeutic load. These two-stage nanoparticles utilize the enhanced permeability and retention (EPR) effect to enable preferential delivery to tumor tissue. However, the size-dependency of the EPR, the limited penetration of nanoparticles into the tumor as well as the rapid binding of the particles or the released cytotoxic agents to cancer cells and stromal components inhibit the uniform distribution of the drug and the efficacy of the treatment. Here, we employ mathematical modeling to study the effect of particle size, drug release rate and binding affinity on the distribution and efficacy of nanoparticles to derive optimal design rules. Furthermore, we introduce a new multi-stage delivery system. The system consists of a 20-nm primary nanoparticle, which releases 5-nm secondary particles, which in turn release the chemotherapeutic drug. We found that tuning the drug release kinetics and binding affinities leads to improved delivery of the drug. Our results also indicate that multi-stage nanoparticles are superior over two-stage nano-carriers provided they have a faster drug release rate and for high binding affinity drugs. Furthermore, our results suggest that smaller nanoparticles achieve better treatment outcome.

Minimizing the Maximum Expected Sample Size in Two-Stage Phase II Clinical Trials with Continuous Outcomes

PubMed Central

Wason, James M. S.; Mander, Adrian P.

2012-01-01

Two-stage designs are commonly used for Phase II trials. Optimal two-stage designs have the lowest expected sample size for a specific treatment effect, for example, the null value, but can perform poorly if the true treatment effect differs. Here we introduce a design for continuous treatment responses that minimizes the maximum expected sample size across all possible treatment effects. The proposed design performs well for a wider range of treatment effects and so is useful for Phase II trials. We compare the design to a previously used optimal design and show it has superior expected sample size properties. PMID:22651118

A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches.

PubMed

Lee, Jung-Gil; Kim, Woo-Seung; Choi, June-Seok; Ghaffour, Noreddine; Kim, Young-Deuk

2016-12-15

An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m 2  at each stage is found to be 21.5 kg. Copyright © 2016 Elsevier Ltd. All rights reserved.

MULTI-STAGE DELIVERY NANO-PARTICLE SYSTEMS FOR THERAPEUTIC APPLICATIONS

PubMed Central

Serda, Rita E.; Godin, Biana; Blanco, Elvin; Chiappini, Ciro; Ferrari, Mauro

2010-01-01

Background The daunting task for drug molecules to reach pathological lesions has fueled rapid advances in Nanomedicine. The progressive evolution of nanovectors has led to the development of multi-stage delivery systems aimed at overcoming the numerous obstacles encountered by nanovectors on their journey to the target site. Scope of Review This review summarizes major findings with respect to silicon-based drug delivery vectors for cancer therapeutics and imaging. Based on rational design, well established silicon technologies have been adapted for the fabrication of nanovectors with specific shapes, sizes, and porosities. These vectors are part of a multi-stage delivery system that contains multiple nano-components, each designed to achieve a specific task with the common goal of site-directed delivery of therapeutics. Major Conclusions Quasi-hemispherical and discoidal silicon microparticles are superior to spherical particles with respect to margination in the blood, with particles of different shapes and sizes having unique distributions in vivo. Cellular adhesion and internalization of silicon microparticles is influenced by microparticle shape and surface charge, with the latter dictating binding of serum opsonins. Based on in vitro cell studies, the internalization of porous silicon microparticles by endothelial cells and macrophages is compatible with cellular morphology, intracellular trafficking, mitosis, cell cycle progression, cytokine release, and cell viability. In vivo studies support superior therapeutic efficacy of liposomal encapsulated siRNA when delivered in multi-stage systems compared to free nanoparticles. PMID:20493927

Note: Modified anvil design for improved reliability in DT-Cup experiments.

PubMed

Hunt, Simon A; Dobson, David P

2017-12-01

The Deformation T-Cup (DT-Cup) is a modified 6-8 multi-anvil apparatus capable of controlled strain-rate deformation experiments at pressures greater than 18 GPa. Controlled strain-rate deformation was enabled by replacing two of the eight cubic "second-stage" anvils with hexagonal cross section deformation anvils and modifying the "first-stage" wedges. However, with these modifications approximately two-thirds of experiments end with rupture of the hexagonal anvils. By replacing the hexagonal anvils with cubic anvils and, split, deformation wedge extensions, we restore the massive support to the deformation anvils that were inherent in the original multi-anvil design and prevent deformation anvil failure. With the modified parts, the DT-Cup has an experimental success rate that is similar to that of a standard hydrostatic 6-8 multi-anvil apparatus.

Design of a conduction-cooled 4 T superconducting racetrack for a multi-field coupling measurement system

NASA Astrophysics Data System (ADS)

Chen, Yu-Quan; Ma, Li-Zhen; Wu, Wei; Guan, Ming-Zhi; Wu, Bei-Min; Mei, En-Ming; Xin, Can-Jie

2015-12-01

A conduction-cooled superconducting magnet producing a transverse field of 4 T has been designed for a new generation multi-field coupling measurement system, which will be used to study the mechanical behavior of superconducting samples at cryogenic temperatures and intense magnetic fields. A compact cryostat with a two-stage GM cryocooler is designed and manufactured for the superconducting magnet. The magnet is composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational former and two Bi2Sr2CaCu2Oy superconducting current leads. The two coils are connected in series and can be powered with a single power supply. In order to support the high stress and attain uniform thermal distribution in the superconducting magnet, a detailed finite element (FE) analysis has been performed. The results indicate that in the operating status the designed magnet system can sufficiently bear the electromagnetic forces and has a uniform temperature distribution. Supported by National Natural Science Foundation of China (11327802, 11302225), China Postdoctoral Science Foundation (2014M560820) and National Scholarship Foundation of China (201404910172)

DNA pooling: a comprehensive, multi-stage association analysis of ACSL6 and SIRT5 polymorphisms in schizophrenia.

PubMed

Chowdari, K V; Northup, A; Pless, L; Wood, J; Joo, Y H; Mirnics, K; Lewis, D A; Levitt, P R; Bacanu, S-A; Nimgaonkar, V L

2007-04-01

Many candidate gene association studies have evaluated incomplete, unrepresentative sets of single nucleotide polymorphisms (SNPs), producing non-significant results that are difficult to interpret. Using a rapid, efficient strategy designed to investigate all common SNPs, we tested associations between schizophrenia and two positional candidate genes: ACSL6 (Acyl-Coenzyme A synthetase long-chain family member 6) and SIRT5 (silent mating type information regulation 2 homologue 5). We initially evaluated the utility of DNA sequencing traces to estimate SNP allele frequencies in pooled DNA samples. The mean variances for the DNA sequencing estimates were acceptable and were comparable to other published methods (mean variance: 0.0008, range 0-0.0119). Using pooled DNA samples from cases with schizophrenia/schizoaffective disorder (Diagnostic and Statistical Manual of Mental Disorders edition IV criteria) and controls (n=200, each group), we next sequenced all exons, introns and flanking upstream/downstream sequences for ACSL6 and SIRT5. Among 69 identified SNPs, case-control allele frequency comparisons revealed nine suggestive associations (P<0.2). Each of these SNPs was next genotyped in the individual samples composing the pools. A suggestive association with rs 11743803 at ACSL6 remained (allele-wise P=0.02), with diminished evidence in an extended sample (448 cases, 554 controls, P=0.062). In conclusion, we propose a multi-stage method for comprehensive, rapid, efficient and economical genetic association analysis that enables simultaneous SNP detection and allele frequency estimation in large samples. This strategy may be particularly useful for research groups lacking access to high throughput genotyping facilities. Our analyses did not yield convincing evidence for associations of schizophrenia with ACSL6 or SIRT5.

Multi-stage Mass Spectrometry of Poly(vinyl pyrrolidone) and Its Vinyl Succinimide Copolymer Formed upon Exposure to Sodium Hypochlorite

PubMed Central

Fouquet, Thierry; Torimura, Masaki; Sato, Hiroaki

2016-01-01

The degradation routes of poly(vinyl pyrrolidone) (PVP) exposed to sodium hypochlorite (bleach) have been previously investigated using chemical analyses such as infrared spectroscopy. So far, no reports have proposed mass spectrometry (MS) as an alternative tool despite its capability to provide molecular and structural information using its single stage electrospray (ESI) or matrix assisted laser desorption ionization (MALDI) and multi stage (MSn) configurations, respectively. The present study thus reports on the characterization of PVP after its exposure to bleach by high resolution MALDI spiralTOF-MS and Kendrick mass defect analysis providing clues as to the formation of a vinyl pyrrolidone/vinyl succinimide copolymeric degradation product. A thorough investigation of the fragmentation pathways of PVP adducted with sodium and proton allows one main route to be described—namely the release of the pyrrolidone pendant group in a charge remote and charge driven mechanism, respectively. Extrapolating this fragmentation pathway, the oxidation of vinyl pyrrolidone into vinyl succinimide hypothesized from the single stage MS is validated by the detection of an alternative succinimide neutral loss in lieu of the pyrrolidone release in the ESI-MSn spectra of the aged PVP sample. It constitutes an example of application of multi-stage mass spectrometry for the characterization of the degradation of polymeric samples at a molecular level. PMID:27800293

Predicting the Performance of an Axial-Flow Compressor

NASA Technical Reports Server (NTRS)

Steinke, R. J.

1986-01-01

Stage-stacking computer code (STGSTK) developed for predicting off-design performance of multi-stage axial-flow compressors. Code uses meanline stagestacking method. Stage and cumulative compressor performance calculated from representative meanline velocity diagrams located at rotor inlet and outlet meanline radii. Numerous options available within code. Code developed so user modify correlations to suit their needs.

A 600 VOLT MULTI-STAGE, HIGH REPETITION RATE GAN FET SWITCH

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

Frolov, D.; Pfeffer, H.; Saewert, G.

Using recently available GaN FETs, a 600 Volt three- stage, multi-FET switch has been developed having 2 nanosecond rise time driving a 200 Ohm load with the potential of approaching 30 MHz average switching rates. Possible applications include driving particle beam choppers kicking bunch-by-bunch and beam deflectors where the rise time needs to be custom tailored. This paper reports on the engineering issues addressed, the design approach taken and some performance results of this switch.

Mars Sample Return Using Solar Sail Propulsion

NASA Technical Reports Server (NTRS)

Johnson, Les; Macdonald, Malcolm; Mcinnes, Colin; Percy, Tom

2012-01-01

Many Mars Sample Return (MSR) architecture studies have been conducted over the years. A key element of them is the Earth Return Stage (ERS) whose objective is to obtain the sample from the Mars Ascent Vehicle (MAV) and return it safely to the surface of the Earth. ERS designs predominantly use chemical propulsion [1], incurring a significant launch mass penalty due to the low specific impulse of such systems coupled with the launch mass sensitivity to returned mass. It is proposed to use solar sail propulsion for the ERS, providing a high (effective) specific impulse propulsion system in the final stage of the multi-stage system. By doing so to the launch mass of the orbiter mission can be significantly reduced and hence potentially decreasing mission cost. Further, solar sailing offers a unique set of non-Keplerian low thrust trajectories that may enable modifications to the current approach to designing the Earth Entry Vehicle by potentially reducing the Earth arrival velocity. This modification will further decrease the mass of the orbiter system. Solar sail propulsion uses sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like surface made of a lightweight, reflective material. The continuous photonic pressure provides propellantless thrust to conduct orbital maneuvering and plane changes more efficiently than conventional chemical propulsion. Because the Sun supplies the necessary propulsive energy, solar sails require no onboard propellant, thus reducing system mass. This technology is currently at TRL 7/8 as demonstrated by the 2010 flight of the Japanese Aerospace Exploration Agency, JAXA, IKAROS mission. [2

Flexible trial design in practice - stopping arms for lack-of-benefit and adding research arms mid-trial in STAMPEDE: a multi-arm multi-stage randomized controlled trial

PubMed Central

2012-01-01

Background Systemic Therapy for Advanced or Metastatic Prostate cancer: Evaluation of Drug Efficacy (STAMPEDE) is a randomized controlled trial that follows a novel multi-arm, multi-stage (MAMS) design. We describe methodological and practical issues arising with (1) stopping recruitment to research arms following a pre-planned intermediate analysis and (2) adding a new research arm during the trial. Methods STAMPEDE recruits men who have locally advanced or metastatic prostate cancer who are starting standard long-term hormone therapy. Originally there were five research and one control arms, each undergoing a pilot stage (focus: safety, feasibility), three intermediate ‘activity’ stages (focus: failure-free survival), and a final ‘efficacy’ stage (focus: overall survival). Lack-of-sufficient-activity guidelines support the pairwise interim comparisons of each research arm against the control arm; these pre-defined activity cut-off becomes increasingly stringent over the stages. Accrual of further patients continues to the control arm and to those research arms showing activity and an acceptable safety profile. The design facilitates adding new research arms should sufficiently interesting agents emerge. These new arms are compared only to contemporaneously recruited control arm patients using the same intermediate guidelines in a time-delayed manner. The addition of new research arms is subject to adequate recruitment rates to support the overall trial aims. Results (1) Stopping Existing Therapy: After the second intermediate activity analysis, recruitment was discontinued to two research arms for lack-of-sufficient activity. Detailed preparations meant that changes were implemented swiftly at 100 international centers and recruitment continued seamlessly into Activity Stage III with 3 remaining research arms and the control arm. Further regulatory and ethical approvals were not required because this was already included in the initial trial design. (2) Adding New Therapy: An application to add a new research arm was approved by the funder, (who also organized peer review), industrial partner and regulatory and ethical bodies. This was all done in advance of any decision to stop current therapies. Conclusions The STAMPEDE experience shows that recruitment to a MAMS trial and mid-flow changes its design are achievable with good planning. This benefits patients and the scientific community as research treatments are evaluated in a more efficient and cost-effective manner. Trial registration ISRCTN78818544, NCT00268476 First patient into trial: 17 October 2005 First patient into abiraterone comparison: 15 November 2011 PMID:22978443

Flexible trial design in practice - stopping arms for lack-of-benefit and adding research arms mid-trial in STAMPEDE: a multi-arm multi-stage randomized controlled trial.

PubMed

Sydes, Matthew R; Parmar, Mahesh K B; Mason, Malcolm D; Clarke, Noel W; Amos, Claire; Anderson, John; de Bono, Johann; Dearnaley, David P; Dwyer, John; Green, Charlene; Jovic, Gordana; Ritchie, Alastair W S; Russell, J Martin; Sanders, Karen; Thalmann, George; James, Nicholas D

2012-09-15

Systemic Therapy for Advanced or Metastatic Prostate cancer: Evaluation of Drug Efficacy (STAMPEDE) is a randomized controlled trial that follows a novel multi-arm, multi-stage (MAMS) design. We describe methodological and practical issues arising with (1) stopping recruitment to research arms following a pre-planned intermediate analysis and (2) adding a new research arm during the trial. STAMPEDE recruits men who have locally advanced or metastatic prostate cancer who are starting standard long-term hormone therapy. Originally there were five research and one control arms, each undergoing a pilot stage (focus: safety, feasibility), three intermediate 'activity' stages (focus: failure-free survival), and a final 'efficacy' stage (focus: overall survival). Lack-of-sufficient-activity guidelines support the pairwise interim comparisons of each research arm against the control arm; these pre-defined activity cut-off becomes increasingly stringent over the stages. Accrual of further patients continues to the control arm and to those research arms showing activity and an acceptable safety profile. The design facilitates adding new research arms should sufficiently interesting agents emerge. These new arms are compared only to contemporaneously recruited control arm patients using the same intermediate guidelines in a time-delayed manner. The addition of new research arms is subject to adequate recruitment rates to support the overall trial aims. (1) Stopping Existing Therapy: After the second intermediate activity analysis, recruitment was discontinued to two research arms for lack-of-sufficient activity. Detailed preparations meant that changes were implemented swiftly at 100 international centers and recruitment continued seamlessly into Activity Stage III with 3 remaining research arms and the control arm. Further regulatory and ethical approvals were not required because this was already included in the initial trial design.(2) Adding New Therapy: An application to add a new research arm was approved by the funder, (who also organized peer review), industrial partner and regulatory and ethical bodies. This was all done in advance of any decision to stop current therapies. The STAMPEDE experience shows that recruitment to a MAMS trial and mid-flow changes its design are achievable with good planning. This benefits patients and the scientific community as research treatments are evaluated in a more efficient and cost-effective manner. ISRCTN78818544, NCT00268476. First patient into trial: 17 October 2005. First patient into abiraterone comparison: 15 November 2011.

Highly loaded multi-stage fan drive turbine: Plain blade configuration design

NASA Technical Reports Server (NTRS)

Evans, D. C.; Wolfmeyer, G. W.

1972-01-01

The constant-inside-diameter flowpath was scaled for testing in an existing turbine test facility. Blading detailed design is discussed, and design data are summarized. Predicted performance maps are presented. Steady-state stresses and vibratory behavior are discussed and the results of the mechanical design analysis are presented.

Modeling the defrost process in complex geometries - Part 1: Development of a one-dimensional defrost model

NASA Astrophysics Data System (ADS)

van Buren, Simon; Hertle, Ellen; Figueiredo, Patric; Kneer, Reinhold; Rohlfs, Wilko

2017-11-01

Frost formation is a common, often undesired phenomenon in heat exchanges such as air coolers. Thus, air coolers have to be defrosted periodically, causing significant energy consumption. For the design and optimization, prediction of defrosting by a CFD tool is desired. This paper presents a one-dimensional transient model approach suitable to be used as a zero-dimensional wall-function in CFD for modeling the defrost process at the fin and tube interfaces. In accordance to previous work a multi stage defrost model is introduced (e.g. [1, 2]). In the first instance the multi stage model is implemented and validated using MATLAB. The defrost process of a one-dimensional frost segment is investigated. Fixed boundary conditions are provided at the frost interfaces. The simulation results verify the plausibility of the designed model. The evaluation of the simulated defrost process shows the expected convergent behavior of the three-stage sequence.

Highly loaded multi-stage fan drive turbine - performance of initial seven configurations

NASA Technical Reports Server (NTRS)

Wolfmeyer, G. W.; Thomas, M. W.

1974-01-01

Experimental results of a three-stage highly loaded fan drive turbine test program are presented. A plain blade turbine, a tandem blade turbine, and a tangentially leaned stator turbine were designed for the same velocity diagram and flowpath. Seven combinations of bladerows were tested to evaluate stage performances and effects of the tandem blading and leaned stator. The plain blade turbine design point total-to-total efficiency was 0.886. The turbine with the stage three leaned stator had the same efficiency with an improved exit swirl profile and increased hub reaction. Two-stage group tests showed that the two-stage turbine with tandem stage two stator had an efficiency of 0.880 compared to 0.868 for the plain blade two-stage turbine.

Guided transect sampling - a new design combining prior information and field surveying

Treesearch

Anna Ringvall; Goran Stahl; Tomas Lamas

2000-01-01

Guided transect sampling is a two-stage sampling design in which prior information is used to guide the field survey in the second stage. In the first stage, broad strips are randomly selected and divided into grid-cells. For each cell a covariate value is estimated from remote sensing data, for example. The covariate is the basis for subsampling of a transect through...

Using extreme phenotype sampling to identify the rare causal variants of quantitative traits in association studies.

PubMed

Li, Dalin; Lewinger, Juan Pablo; Gauderman, William J; Murcray, Cassandra Elizabeth; Conti, David

2011-12-01

Variants identified in recent genome-wide association studies based on the common-disease common-variant hypothesis are far from fully explaining the hereditability of complex traits. Rare variants may, in part, explain some of the missing hereditability. Here, we explored the advantage of the extreme phenotype sampling in rare-variant analysis and refined this design framework for future large-scale association studies on quantitative traits. We first proposed a power calculation approach for a likelihood-based analysis method. We then used this approach to demonstrate the potential advantages of extreme phenotype sampling for rare variants. Next, we discussed how this design can influence future sequencing-based association studies from a cost-efficiency (with the phenotyping cost included) perspective. Moreover, we discussed the potential of a two-stage design with the extreme sample as the first stage and the remaining nonextreme subjects as the second stage. We demonstrated that this two-stage design is a cost-efficient alternative to the one-stage cross-sectional design or traditional two-stage design. We then discussed the analysis strategies for this extreme two-stage design and proposed a corresponding design optimization procedure. To address many practical concerns, for example measurement error or phenotypic heterogeneity at the very extremes, we examined an approach in which individuals with very extreme phenotypes are discarded. We demonstrated that even with a substantial proportion of these extreme individuals discarded, an extreme-based sampling can still be more efficient. Finally, we expanded the current analysis and design framework to accommodate the CMC approach where multiple rare-variants in the same gene region are analyzed jointly. © 2011 Wiley Periodicals, Inc.

Using Extreme Phenotype Sampling to Identify the Rare Causal Variants of Quantitative Traits in Association Studies

PubMed Central

Li, Dalin; Lewinger, Juan Pablo; Gauderman, William J.; Murcray, Cassandra Elizabeth; Conti, David

2014-01-01

Variants identified in recent genome-wide association studies based on the common-disease common-variant hypothesis are far from fully explaining the hereditability of complex traits. Rare variants may, in part, explain some of the missing hereditability. Here, we explored the advantage of the extreme phenotype sampling in rare-variant analysis and refined this design framework for future large-scale association studies on quantitative traits. We first proposed a power calculation approach for a likelihood-based analysis method. We then used this approach to demonstrate the potential advantages of extreme phenotype sampling for rare variants. Next, we discussed how this design can influence future sequencing-based association studies from a cost-efficiency (with the phenotyping cost included) perspective. Moreover, we discussed the potential of a two-stage design with the extreme sample as the first stage and the remaining nonextreme subjects as the second stage. We demonstrated that this two-stage design is a cost-efficient alternative to the one-stage cross-sectional design or traditional two-stage design. We then discussed the analysis strategies for this extreme two-stage design and proposed a corresponding design optimization procedure. To address many practical concerns, for example measurement error or phenotypic heterogeneity at the very extremes, we examined an approach in which individuals with very extreme phenotypes are discarded. We demonstrated that even with a substantial proportion of these extreme individuals discarded, an extreme-based sampling can still be more efficient. Finally, we expanded the current analysis and design framework to accommodate the CMC approach where multiple rare-variants in the same gene region are analyzed jointly. PMID:21922541

Material efficiency studies for a Compton camera designed to measure characteristic prompt gamma rays emitted during proton beam radiotherapy

PubMed Central

Robertson, Daniel; Polf, Jerimy C; Peterson, Steve W; Gillin, Michael T; Beddar, Sam

2011-01-01

Prompt gamma rays emitted from biological tissues during proton irradiation carry dosimetric and spectroscopic information that can assist with treatment verification and provide an indication of the biological response of the irradiated tissues. Compton cameras are capable of determining the origin and energy of gamma rays. However, prompt gamma monitoring during proton therapy requires new Compton camera designs that perform well at the high gamma energies produced when tissues are bombarded with therapeutic protons. In this study we optimize the materials and geometry of a three-stage Compton camera for prompt gamma detection and calculate the theoretical efficiency of such a detector. The materials evaluated in this study include germanium, bismuth germanate (BGO), NaI, xenon, silicon and lanthanum bromide (LaBr3). For each material, the dimensions of each detector stage were optimized to produce the maximum number of relevant interactions. These results were used to predict the efficiency of various multi-material cameras. The theoretical detection efficiencies of the most promising multi-material cameras were then calculated for the photons emitted from a tissue-equivalent phantom irradiated by therapeutic proton beams ranging from 50 to 250 MeV. The optimized detector stages had a lateral extent of 10 × 10 cm2 with the thickness of the initial two stages dependent on the detector material. The thickness of the third stage was fixed at 10 cm regardless of material. The most efficient single-material cameras were composed of germanium (3 cm) and BGO (2.5 cm). These cameras exhibited efficiencies of 1.15 × 10−4 and 9.58 × 10−5 per incident proton, respectively. The most efficient multi-material camera design consisted of two initial stages of germanium (3 cm) and a final stage of BGO, resulting in a theoretical efficiency of 1.26 × 10−4 per incident proton. PMID:21508442

Exprimental Results of the First Two Stages of an Advanced Transonic Core Compressor Under Isolated and Multi-Stage Conditions.

NASA Technical Reports Server (NTRS)

Prahst, Patricia S.; Kulkarni, Sameer; Sohn, Ki H.

2015-01-01

NASA's Environmentally Responsible Aviation (ERA) Program calls for investigation of the technology barriers associated with improved fuel efficiency for large gas turbine engines. Under ERA, the highly loaded core compressor technology program attempts to realize the fuel burn reduction goal by increasing overall pressure ratio of the compressor to increase thermal efficiency of the engine. Study engines with overall pressure ratio of 60 to 70 are now being investigated. This means that the high pressure compressor would have to almost double in pressure ratio while keeping a high level of efficiency. NASA and GE teamed to address this challenge by testing the first two stages of an advanced GE compressor designed to meet the requirements of a very high pressure ratio core compressor. Previous test experience of a compressor which included these front two stages indicated a performance deficit relative to design intent. Therefore, the current rig was designed to run in 1-stage and 2-stage configurations in two separate tests to assess whether the bow shock of the second rotor interacting with the upstream stage contributed to the unpredicted performance deficit, or if the culprit was due to interaction of rotor 1 and stator 1. Thus, the goal was to fully understand the stage 1 performance under isolated and multi-stage conditions, and additionally to provide a detailed aerodynamic data set for CFD validation. Full use was made of steady and unsteady measurement methods to understand fluid dynamics loss source mechanisms due to rotor shock interaction and endwall losses. This paper will present the description of the compressor test article and its measured performance and operability, for both the single stage and two stage configurations. We focus the paper on measurements at 97% corrected speed with design intent vane setting angles.

Creation of an Upper Stage Trajectory Capability Boundary to Enable Booster System Trade Space Exploration

NASA Technical Reports Server (NTRS)

Walsh, Ptrick; Coulon, Adam; Edwards, Stephen; Mavris, Dimitri N.

2012-01-01

The problem of trajectory optimization is important in all space missions. The solution of this problem enables one to specify the optimum thrust steering program which should be followed to achieve a specified mission objective, simultaneously satisfying the constraints.1 It is well known that whether or not the ascent trajectory is optimal can have a significant impact on propellant usage for a given payload, or on payload weight for the same gross vehicle weight.2 Consequently, ascent guidance commands are usually optimized in some fashion. Multi-stage vehicles add complexity to this analysis process as changes in vehicle properties in one stage propagate to the other stages through gear ratios and changes in the optimal trajectory. These effects can cause an increase in analysis time as more variables are added and convergence of the optimizer to system closure requires more analysis iterations. In this paper, an approach to simplifying this multi-stage problem through the creation of an upper stage capability boundary is presented. This work was completed as part of a larger study focused on trade space exploration for the advanced booster system that will eventually form a part of NASA s new Space Launch System.3 The approach developed leverages Design of Experiments and Surrogate Modeling4 techniques to create a predictive model of the SLS upper stage performance. The design of the SLS core stages is considered fixed for the purposes of this study, which results in trajectory parameters such as staging conditions being the only variables relevant to the upper stage. Through the creation of a surrogate model, which takes staging conditions as inputs and predicts the payload mass delivered by the SLS upper stage to a reference orbit as the response, it is possible to identify a "surface" of staging conditions which all satisfy the SLS requirement of placing 130 metric tons into low-Earth orbit (LEO).3 This identified surface represents the 130 metric ton capability boundary for the upper stage, such that if the combined first stage and boosters can achieve any one staging point on that surface, then the design is identified as feasible. With the surrogate model created, design and analysis of advanced booster concepts is streamlined, as optimization of the upper stage trajectory is no longer required in every design loop.

Parameter Estimation of Computationally Expensive Watershed Models Through Efficient Multi-objective Optimization and Interactive Decision Analytics

NASA Astrophysics Data System (ADS)

Akhtar, Taimoor; Shoemaker, Christine

2016-04-01

Watershed model calibration is inherently a multi-criteria problem. Conflicting trade-offs exist between different quantifiable calibration criterions indicating the non-existence of a single optimal parameterization. Hence, many experts prefer a manual approach to calibration where the inherent multi-objective nature of the calibration problem is addressed through an interactive, subjective, time-intensive and complex decision making process. Multi-objective optimization can be used to efficiently identify multiple plausible calibration alternatives and assist calibration experts during the parameter estimation process. However, there are key challenges to the use of multi objective optimization in the parameter estimation process which include: 1) multi-objective optimization usually requires many model simulations, which is difficult for complex simulation models that are computationally expensive; and 2) selection of one from numerous calibration alternatives provided by multi-objective optimization is non-trivial. This study proposes a "Hybrid Automatic Manual Strategy" (HAMS) for watershed model calibration to specifically address the above-mentioned challenges. HAMS employs a 3-stage framework for parameter estimation. Stage 1 incorporates the use of an efficient surrogate multi-objective algorithm, GOMORS, for identification of numerous calibration alternatives within a limited simulation evaluation budget. The novelty of HAMS is embedded in Stages 2 and 3 where an interactive visual and metric based analytics framework is available as a decision support tool to choose a single calibration from the numerous alternatives identified in Stage 1. Stage 2 of HAMS provides a goodness-of-fit measure / metric based interactive framework for identification of a small subset (typically less than 10) of meaningful and diverse set of calibration alternatives from the numerous alternatives obtained in Stage 1. Stage 3 incorporates the use of an interactive visual analytics framework for decision support in selection of one parameter combination from the alternatives identified in Stage 2. HAMS is applied for calibration of flow parameters of a SWAT model, (Soil and Water Assessment Tool) designed to simulate flow in the Cannonsville watershed in upstate New York. Results from the application of HAMS to Cannonsville indicate that efficient multi-objective optimization and interactive visual and metric based analytics can bridge the gap between the effective use of both automatic and manual strategies for parameter estimation of computationally expensive watershed models.

Multi-Drafting Feedback Process in a Web-Based Environment

ERIC Educational Resources Information Center

Peled, Yehuda; Sarid, Miriam

2010-01-01

Purpose: The purpose of this paper is to explore the nature of multi-drafting among college students according to demographic characteristics and measure its impact on students' achievements. Design/methodology/approach: The research was conducted in two stages. First, a preliminary research based on data from the Highlearn web-based content…

Sample size re-estimation and other midcourse adjustments with sequential parallel comparison design.

PubMed

Silverman, Rachel K; Ivanova, Anastasia

2017-01-01

Sequential parallel comparison design (SPCD) was proposed to reduce placebo response in a randomized trial with placebo comparator. Subjects are randomized between placebo and drug in stage 1 of the trial, and then, placebo non-responders are re-randomized in stage 2. Efficacy analysis includes all data from stage 1 and all placebo non-responding subjects from stage 2. This article investigates the possibility to re-estimate the sample size and adjust the design parameters, allocation proportion to placebo in stage 1 of SPCD, and weight of stage 1 data in the overall efficacy test statistic during an interim analysis.

From Solidification Processing to Microstructure to Mechanical Properties: A Multi-scale X-ray Study of an Al-Cu Alloy Sample

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

Tourret, D.; Mertens, J. C. E.; Lieberman, E.

We follow an Al-12 at. pct Cu alloy sample from the liquid state to mechanical failure, using in situ X-ray radiography during directional solidification and tensile testing, as well as three-dimensional computed tomography of the microstructure before and after mechanical testing. The solidification processing stage is simulated with a multi-scale dendritic needle network model, and the micromechanical behavior of the solidified microstructure is simulated using voxelized tomography data and an elasto-viscoplastic fast Fourier transform model. This study demonstrates the feasibility of direct in situ monitoring of a metal alloy microstructure from the liquid processing stage up to its mechanical failure,more » supported by quantitative simulations of microstructure formation and its mechanical behavior.« less

From Solidification Processing to Microstructure to Mechanical Properties: A Multi-scale X-ray Study of an Al-Cu Alloy Sample

DOE PAGES

Tourret, D.; Mertens, J. C. E.; Lieberman, E.; ...

2017-09-13

We follow an Al-12 at. pct Cu alloy sample from the liquid state to mechanical failure, using in situ X-ray radiography during directional solidification and tensile testing, as well as three-dimensional computed tomography of the microstructure before and after mechanical testing. The solidification processing stage is simulated with a multi-scale dendritic needle network model, and the micromechanical behavior of the solidified microstructure is simulated using voxelized tomography data and an elasto-viscoplastic fast Fourier transform model. This study demonstrates the feasibility of direct in situ monitoring of a metal alloy microstructure from the liquid processing stage up to its mechanical failure,more » supported by quantitative simulations of microstructure formation and its mechanical behavior.« less

From Solidification Processing to Microstructure to Mechanical Properties: A Multi-scale X-ray Study of an Al-Cu Alloy Sample

NASA Astrophysics Data System (ADS)

Tourret, D.; Mertens, J. C. E.; Lieberman, E.; Imhoff, S. D.; Gibbs, J. W.; Henderson, K.; Fezzaa, K.; Deriy, A. L.; Sun, T.; Lebensohn, R. A.; Patterson, B. M.; Clarke, A. J.

2017-11-01

We follow an Al-12 at. pct Cu alloy sample from the liquid state to mechanical failure, using in situ X-ray radiography during directional solidification and tensile testing, as well as three-dimensional computed tomography of the microstructure before and after mechanical testing. The solidification processing stage is simulated with a multi-scale dendritic needle network model, and the micromechanical behavior of the solidified microstructure is simulated using voxelized tomography data and an elasto-viscoplastic fast Fourier transform model. This study demonstrates the feasibility of direct in situ monitoring of a metal alloy microstructure from the liquid processing stage up to its mechanical failure, supported by quantitative simulations of microstructure formation and its mechanical behavior.

A Pilot Sampling Design for Estimating Outdoor Recreation Site Visits on the National Forests

Treesearch

Stanley J. Zarnoch; S.M. Kocis; H. Ken Cordell; D.B.K. English

2002-01-01

A pilot sampling design is described for estimating site visits to National Forest System lands. The three-stage sampling design consisted of national forest ranger districts, site days within ranger districts, and last-exiting recreation visitors within site days. Stratification was used at both the primary and secondary stages. Ranger districts were stratified based...

Residents Living in Residential Care Facilities: United States, 2010

MedlinePlus

... NSRCF used a stratified two-stage probability sample design. The first stage was the selection of RCFs ... was 99%. A detailed description of NSRCF sampling design, data collection, and procedures is provided both in ...

Design of telehealth trials--introducing adaptive approaches.

PubMed

Law, Lisa M; Wason, James M S

2014-12-01

The field of telehealth and telemedicine is expanding as the need to improve efficiency of health care becomes more pressing. The decision to implement a telehealth system is generally an expensive undertaking that impacts a large number of patients and other stakeholders. It is therefore extremely important that the decision is fully supported by accurate evaluation of telehealth interventions. Numerous reviews of telehealth have described the evidence base as inconsistent. In response they call for larger, more rigorously controlled trials, and trials which go beyond evaluation of clinical effectiveness alone. The aim of this paper is to discuss various ways in which evaluation of telehealth could be improved by the use of adaptive trial designs. We discuss various adaptive design options, such as sample size reviews and changing the study hypothesis to address uncertain parameters, group sequential trials and multi-arm multi-stage trials to improve efficiency, and enrichment designs to maximise the chances of obtaining clear evidence about the telehealth intervention. There is potential to address the flaws discussed in the telehealth literature through the adoption of adaptive approaches to trial design. Such designs could lead to improvements in efficiency, allow the evaluation of multiple telehealth interventions in a cost-effective way, or accurately assess a range of endpoints that are important in the overall success of a telehealth programme. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Multi-mode sliding mode control for precision linear stage based on fixed or floating stator.

PubMed

Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei

2016-02-01

This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.

Constraint Force Equation Methodology for Modeling Multi-Body Stage Separation Dynamics

NASA Technical Reports Server (NTRS)

Toniolo, Matthew D.; Tartabini, Paul V.; Pamadi, Bandu N.; Hotchko, Nathaniel

2008-01-01

This paper discusses a generalized approach to the multi-body separation problems in a launch vehicle staging environment based on constraint force methodology and its implementation into the Program to Optimize Simulated Trajectories II (POST2), a widely used trajectory design and optimization tool. This development facilitates the inclusion of stage separation analysis into POST2 for seamless end-to-end simulations of launch vehicle trajectories, thus simplifying the overall implementation and providing a range of modeling and optimization capabilities that are standard features in POST2. Analysis and results are presented for two test cases that validate the constraint force equation methodology in a stand-alone mode and its implementation in POST2.

Ram-air sample collection device for a chemical warfare agent sensor

DOEpatents

Megerle, Clifford A.; Adkins, Douglas R.; Frye-Mason, Gregory C.

2002-01-01

In a surface acoustic wave sensor mounted within a body, the sensor having a surface acoustic wave array detector and a micro-fabricated sample preconcentrator exposed on a surface of the body, an apparatus for collecting air for the sensor, comprising a housing operatively arranged to mount atop the body, the housing including a multi-stage channel having an inlet and an outlet, the channel having a first stage having a first height and width proximate the inlet, a second stage having a second lower height and width proximate the micro-fabricated sample preconcentrator, a third stage having a still lower third height and width proximate the surface acoustic wave array detector, and a fourth stage having a fourth height and width proximate the outlet, where the fourth height and width are substantially the same as the first height and width.

Improved design for a low temperature scanning tunneling microscope with an in situ tip treatment stage.

PubMed

Kim, J-J; Joo, S H; Lee, K S; Yoo, J H; Park, M S; Kwak, J S; Lee, Jinho

2017-04-01

The Low Temperature Scanning Tunneling Microscope (LT-STM) is an extremely valuable tool not only in surface science but also in condensed matter physics. For years, numerous new ideas have been adopted to perfect LT-STM performances-Ultra-Low Vibration (ULV) laboratory and the rigid STM head design are among them. Here, we present three improvements for the design of the ULV laboratory and the LT-STM: tip treatment stage, sample cleaving stage, and vibration isolation system. The improved tip treatment stage enables us to perform field emission for the purpose of tip treatment in situ without exchanging samples, while our enhanced sample cleaving stage allows us to cleave samples at low temperature in a vacuum without optical access by a simple pressing motion. Our newly designed vibration isolation system provides efficient space usage while maintaining vibration isolation capability. These improvements enhance the quality of spectroscopic imaging experiments that can last for many days and provide increased data yield, which we expect can be indispensable elements in future LT-STM designs.

A sequential bioequivalence design with a potential ethical advantage.

PubMed

Fuglsang, Anders

2014-07-01

This paper introduces a two-stage approach for evaluation of bioequivalence, where, in contrast to the designs of Diane Potvin and co-workers, two stages are mandatory regardless of the data obtained at stage 1. The approach is derived from Potvin's method C. It is shown that under circumstances with relatively high variability and relatively low initial sample size, this method has an advantage over Potvin's approaches in terms of sample sizes while controlling type I error rates at or below 5% with a minute occasional trade-off in power. Ethically and economically, the method may thus be an attractive alternative to the Potvin designs. It is also shown that when using the method introduced here, average total sample sizes are rather independent of initial sample size. Finally, it is shown that when a futility rule in terms of sample size for stage 2 is incorporated into this method, i.e., when a second stage can be abolished due to sample size considerations, there is often an advantage in terms of power or sample size as compared to the previously published methods.

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil.

PubMed

Ximenes, Ricardo Arraes de Alencar; Pereira, Leila Maria Beltrão; Martelli, Celina Maria Turchi; Merchán-Hamann, Edgar; Stein, Airton Tetelbom; Figueiredo, Gerusa Maria; Braga, Maria Cynthia; Montarroyos, Ulisses Ramos; Brasil, Leila Melo; Turchi, Marília Dalva; Fonseca, José Carlos Ferraz da; Lima, Maria Luiza Carvalho de; Alencar, Luis Cláudio Arraes de; Costa, Marcelo; Coral, Gabriela; Moreira, Regina Celia; Cardoso, Maria Regina Alves

2010-09-01

A population-based survey to provide information on the prevalence of hepatitis viral infection and the pattern of risk factors was carried out in the urban population of all Brazilian state capitals and the Federal District, between 2005 and 2009. This paper describes the design and methodology of the study which involved a population aged 5 to 19 for hepatitis A and 10 to 69 for hepatitis B and C. Interviews and blood samples were obtained through household visits. The sample was selected using stratified multi-stage cluster sampling and was drawn with equal probability from each domain of study (region and age-group). Nationwide, 19,280 households and ~31,000 residents were selected. The study is large enough to detect prevalence of viral infection around 0.1% and risk factor assessments within each region. The methodology seems to be a viable way of differentiating between distinct epidemiological patterns of hepatitis A, B and C. These data will be of value for the evaluation of vaccination policies and for the design of control program strategies.

Off-Design Performance of a Multi-Stage Supersonic Turbine

NASA Technical Reports Server (NTRS)

Dorney, Daniel J.; Griffin, Lisa W.; Huber, Frank; Sondak, Douglas L.

2003-01-01

The drive towards high-work turbines has led to designs which can be compact, transonic, supersonic, counter rotating, or use a dense drive gas. These aggressive designs can lead to strong unsteady secondary flows and flow separation. The amplitude and extent of these unsteady flow phenomena can be amplified at off-design operating conditions. Pre-test off-design predictions have been performed for a new two-stage supersonic turbine design that is currently being tested in air. The simulations were performed using a three-dimensional unsteady Navier-Stokes analysis, and the predicted results have been compared with solutions from a validated meanline analysis.

Sampling Methods in Cardiovascular Nursing Research: An Overview.

PubMed

Kandola, Damanpreet; Banner, Davina; O'Keefe-McCarthy, Sheila; Jassal, Debbie

2014-01-01

Cardiovascular nursing research covers a wide array of topics from health services to psychosocial patient experiences. The selection of specific participant samples is an important part of the research design and process. The sampling strategy employed is of utmost importance to ensure that a representative sample of participants is chosen. There are two main categories of sampling methods: probability and non-probability. Probability sampling is the random selection of elements from the population, where each element of the population has an equal and independent chance of being included in the sample. There are five main types of probability sampling including simple random sampling, systematic sampling, stratified sampling, cluster sampling, and multi-stage sampling. Non-probability sampling methods are those in which elements are chosen through non-random methods for inclusion into the research study and include convenience sampling, purposive sampling, and snowball sampling. Each approach offers distinct advantages and disadvantages and must be considered critically. In this research column, we provide an introduction to these key sampling techniques and draw on examples from the cardiovascular research. Understanding the differences in sampling techniques may aid nurses in effective appraisal of research literature and provide a reference pointfor nurses who engage in cardiovascular research.

A Bayesian-frequentist two-stage single-arm phase II clinical trial design.

PubMed

Dong, Gaohong; Shih, Weichung Joe; Moore, Dirk; Quan, Hui; Marcella, Stephen

2012-08-30

It is well-known that both frequentist and Bayesian clinical trial designs have their own advantages and disadvantages. To have better properties inherited from these two types of designs, we developed a Bayesian-frequentist two-stage single-arm phase II clinical trial design. This design allows both early acceptance and rejection of the null hypothesis ( H(0) ). The measures (for example probability of trial early termination, expected sample size, etc.) of the design properties under both frequentist and Bayesian settings are derived. Moreover, under the Bayesian setting, the upper and lower boundaries are determined with predictive probability of trial success outcome. Given a beta prior and a sample size for stage I, based on the marginal distribution of the responses at stage I, we derived Bayesian Type I and Type II error rates. By controlling both frequentist and Bayesian error rates, the Bayesian-frequentist two-stage design has special features compared with other two-stage designs. Copyright © 2012 John Wiley & Sons, Ltd.

Optimality, sample size, and power calculations for the sequential parallel comparison design.

PubMed

Ivanova, Anastasia; Qaqish, Bahjat; Schoenfeld, David A

2011-10-15

The sequential parallel comparison design (SPCD) has been proposed to increase the likelihood of success of clinical trials in therapeutic areas where high-placebo response is a concern. The trial is run in two stages, and subjects are randomized into three groups: (i) placebo in both stages; (ii) placebo in the first stage and drug in the second stage; and (iii) drug in both stages. We consider the case of binary response data (response/no response). In the SPCD, all first-stage and second-stage data from placebo subjects who failed to respond in the first stage of the trial are utilized in the efficacy analysis. We develop 1 and 2 degree of freedom score tests for treatment effect in the SPCD. We give formulae for asymptotic power and for sample size computations and evaluate their accuracy via simulation studies. We compute the optimal allocation ratio between drug and placebo in stage 1 for the SPCD to determine from a theoretical viewpoint whether a single-stage design, a two-stage design with placebo only in the first stage, or a two-stage design is the best design for a given set of response rates. As response rates are not known before the trial, a two-stage approach with allocation to active drug in both stages is a robust design choice. Copyright © 2011 John Wiley & Sons, Ltd.

Reconfigurable radio receiver with fractional sample rate converter and multi-rate ADC based on LO-derived sampling clock

NASA Astrophysics Data System (ADS)

Park, Sungkyung; Park, Chester Sungchung

2018-03-01

A composite radio receiver back-end and digital front-end, made up of a delta-sigma analogue-to-digital converter (ADC) with a high-speed low-noise sampling clock generator, and a fractional sample rate converter (FSRC), is proposed and designed for a multi-mode reconfigurable radio. The proposed radio receiver architecture contributes to saving the chip area and thus lowering the design cost. To enable inter-radio access technology handover and ultimately software-defined radio reception, a reconfigurable radio receiver consisting of a multi-rate ADC with its sampling clock derived from a local oscillator, followed by a rate-adjustable FSRC for decimation, is designed. Clock phase noise and timing jitter are examined to support the effectiveness of the proposed radio receiver. A FSRC is modelled and simulated with a cubic polynomial interpolator based on Lagrange method, and its spectral-domain view is examined in order to verify its effect on aliasing, nonlinearity and signal-to-noise ratio, giving insight into the design of the decimation chain. The sampling clock path and the radio receiver back-end data path are designed in a 90-nm CMOS process technology with 1.2V supply.

Ramping up to the Biology Workbench: A Multi-Stage Approach to Bioinformatics Education

ERIC Educational Resources Information Center

Greene, Kathleen; Donovan, Sam

2005-01-01

In the process of designing and field-testing bioinformatics curriculum materials, we have adopted a three-stage, progressive model that emphasizes collaborative scientific inquiry. The elements of the model include: (1) context setting, (2) introduction to concepts, processes, and tools, and (3) development of competent use of technologically…

Prevalence of hepatitis B and C virus infections and their related risk factors in Libya: a national seroepidemiological survey.

PubMed

Elzouki, A-N; Smeo, M-N; Sammud, M; Elahmer, O; Daw, M; Furarah, A; Abudher, A; Mohamed, M K

2013-07-01

A high prevalence of hepatitis B (HBV) and C virus (HCV) infections has been reported among specific patient groups in Libya; a survey was thus designed to determine the extent of the problem at the national level. A multi-stage sampling design covering all administrative areas of Libya was applied, covering > 65,000 individuals of all age groups. All subjects gave a blood sample and completed a questionnaire on demographic and risk behaviour data. The prevalence of HBV surface antigen (HBsAg) and anti-HCV were 2.2% and 1.3% respectively. The prevalence of anti-HCV increased with age, rising gradually after age 30 years, in contrast to a stable prevalence of HBsAg in all age groups 10+ years. Age-adjusted risk factors for HCV infection were previous hospitalization, surgical operations, previous blood transfusions and intravenous drug use; for HBV infection only family exposure or contact with HBV case were identified.

Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

NASA Astrophysics Data System (ADS)

Azizi, Mohammad Ali; Brouwer, Jacob

2017-10-01

A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

Multi-water-bag models of ion temperature gradient instability in cylindrical geometry

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

Coulette, David; Besse, Nicolas

2013-05-15

Ion temperature gradient instabilities play a major role in the understanding of anomalous transport in core fusion plasmas. In the considered cylindrical geometry, ion dynamics is described using a drift-kinetic multi-water-bag model for the parallel velocity dependency of the ion distribution function. In a first stage, global linear stability analysis is performed. From the obtained normal modes, parametric dependencies of the main spectral characteristics of the instability are then examined. Comparison of the multi-water-bag results with a reference continuous Maxwellian case allows us to evaluate the effects of discrete parallel velocity sampling induced by the Multi-Water-Bag model. Differences between themore » global model and local models considered in previous works are discussed. Using results from linear, quasilinear, and nonlinear numerical simulations, an analysis of the first stage saturation dynamics of the instability is proposed, where the divergence between the three models is examined.« less

Spectral Discrimination of the Invasive Plant Spartina alterniflora at Multiple Phenological Stages in a Saltmarsh Wetland

PubMed Central

Ouyang, Zu-Tao; Gao, Yu; Xie, Xiao; Guo, Hai-Qiang; Zhang, Ting-Ting; Zhao, Bin

2013-01-01

Spartina alterniflora has widely invaded the saltmarshes of the Yangtze River Estuary and brought negative effects to the ecosystem. Remote sensing technique has recently been used to monitor its distribution, but the similar morphology and canopy structure among S. alterniflora and its neighbor species make it difficult even with high-resolution images. Nevertheless, these species have divergence on phenological stages throughout the year, which cause distinguishing spectral characteristics among them and provide opportunities for discrimination. The field spectra of the S. alterniflora community as well as its major victims, native Phragmites australis and Scirpus mariqueter, were measured in 2009 and 2010 at multi-phenological stages in the Yangtze River Estuary, aiming to find the most appropriate periods for mapping S. alterniflora. Collected spectral data were analyzed separately for every stage firstly by re-sampling reflectance curves into continued 5-nm-wide hyper-spectral bands and then by re-sampling into broad multi-spectral bands – the same as the band ranges of the TM sensor, as well as calculating commonly used vegetation indices. The results showed that differences among saltmarsh communities’ spectral characteristics were affected by their phenological stages. The germination and early vegetative growth stage and the flowering stage were probably the best timings to identify S. alterniflora. Vegetation indices like NDVI, ANVI, VNVI, and RVI are likely to enhance spectral separability and also make it possible to discriminate S. alterniflora at its withering stage. PMID:23826265

Multi-Mission System Analysis for Planetary Entry (M-SAPE) Version 1

NASA Technical Reports Server (NTRS)

Samareh, Jamshid; Glaab, Louis; Winski, Richard G.; Maddock, Robert W.; Emmett, Anjie L.; Munk, Michelle M.; Agrawal, Parul; Sepka, Steve; Aliaga, Jose; Zarchi, Kerry;

RGO/AuNR/HA-5FU nanocomposite with multi-stage release behavior and efficient antitumor activity for synergistic therapy.

PubMed

Yang, Ying; Wang, Yunlong; Zhu, Manzhou; Chen, Yan; Xiao, Yazhong; Shen, Yuhua; Xie, Anjian

2017-05-02

A reduced graphene oxide (RGO)/gold nanorod (AuNR)/hydroxyapatite (HA) nanocomposite was designed and successfully synthesized for the first time. An anticancer drug, 5-fluorouracil (5FU), was chosen as a model drug to be loaded in RGO/AuNR/HA. The fabricated RGO/AuNR/HA-5FU showed robust, selective targeting and penetrating efficiency against HeLa cells due to the good compatibility and nontoxicity of HA, and showed excellent synergetic antitumor effects through combined chemotherapy (CT) by 5FU and photothermal therapy (PTT) by both RGO and AuNRs under near-infrared (NIR) laser irradiation. More importantly, this synergistic dual therapy based on RGO/AuNR/HA can also minimize side effects in normal cells and exhibits greater antitumor activity because of a multi-stage drug release ability triggered by the pH sensitivity of HA in the first stage and the combined photothermal conversion capabilities of RGO and AuNRs by means of the NIR laser irradiation in the second stage. This study suggests that the novel RGO/AuNR/HA multi-stage drug delivery system may represent a promising potential application of multifunctional composite materials in the biomedical field.

Evaluation of single and two-stage adaptive sampling designs for estimation of density and abundance of freshwater mussels in a large river

USGS Publications Warehouse

Smith, D.R.; Rogala, J.T.; Gray, B.R.; Zigler, S.J.; Newton, T.J.

2011-01-01

Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non-adaptive versions of single and two-stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two-stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers.

Types of Bullying in the Senior High Schools in Ghana

ERIC Educational Resources Information Center

Antiri, Kwasi Otopa

2016-01-01

The main objective of the study was to examine the types of bullying that were taking place in the senior high schools in Ghana. A multi-stage sampling procedure, comprising purposive, simple random and snowball sampling technique, was used in the selection of the sample. A total of 354 respondents were drawn six schools in Ashanti, Central and…

The stage-specific in vitro efficacy of a malaria antigen cocktail provides valuable insights into the development of effective multi-stage vaccines.

PubMed

Spiegel, Holger; Boes, Alexander; Kastilan, Robin; Kapelski, Stephanie; Edgue, Güven; Beiss, Veronique; Chubodova, Ivana; Scheuermayer, Matthias; Pradel, Gabriele; Schillberg, Stefan; Reimann, Andreas; Fischer, Rainer

2015-10-01

Multicomponent vaccines targeting different stages of Plasmodium falciparum represent a promising, holistic concept towards better malaria vaccines. Additionally, an effective vaccine candidate should demonstrate cross-strain specificity because many antigens are polymorphic, which can reduce vaccine efficacy. A cocktail of recombinant fusion proteins (VAMAX-Mix) featuring three diversity-covering variants of the blood-stage antigen PfAMA1, each combined with the conserved sexual-stage antigen Pfs25 and one of the pre-erythrocytic-stage antigens PfCSP_TSR or PfCelTOS, or the additional blood-stage antigen PfMSP1_19, was produced in Pichia pastoris and used to immunize rabbits. The immune sera and purified IgG were used to perform various assays determining antigen specific titers and in vitro efficacy against different parasite stages and strains. In functional in vitro assays we observed robust inhibition of blood-stage (up to 90%), and sexual-stage parasites (up to 100%) and biased inhibition of pre-erythrocytic parasites (0-40%). Cross-strain blood-stage efficacy was observed in erythrocyte invasion assays using four different P. falciparum strains. The quantification of antigen-specific IgGs allowed the determination of specific IC50 values. The significant difference in antigen-specific IC50 requirements, the direct correlation between antigen-specific IgG and the relative quantitative representation of antigens within the cocktail, provide valuable implementations for future multi-stage, multi-component vaccine designs. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Estimating accuracy of land-cover composition from two-stage cluster sampling

USGS Publications Warehouse

Stehman, S.V.; Wickham, J.D.; Fattorini, L.; Wade, T.D.; Baffetta, F.; Smith, J.H.

2009-01-01

Land-cover maps are often used to compute land-cover composition (i.e., the proportion or percent of area covered by each class), for each unit in a spatial partition of the region mapped. We derive design-based estimators of mean deviation (MD), mean absolute deviation (MAD), root mean square error (RMSE), and correlation (CORR) to quantify accuracy of land-cover composition for a general two-stage cluster sampling design, and for the special case of simple random sampling without replacement (SRSWOR) at each stage. The bias of the estimators for the two-stage SRSWOR design is evaluated via a simulation study. The estimators of RMSE and CORR have small bias except when sample size is small and the land-cover class is rare. The estimator of MAD is biased for both rare and common land-cover classes except when sample size is large. A general recommendation is that rare land-cover classes require large sample sizes to ensure that the accuracy estimators have small bias. ?? 2009 Elsevier Inc.

Tracing the Cascade of Children's Insecurity in the Interparental Relationship: The Role of Stage-Salient Tasks

ERIC Educational Resources Information Center

Davies, Patrick T.; Manning, Liviah G.; Cicchetti, Dante

2013-01-01

This study examined whether children’s difficulties with stage-salient tasks served as an explanatory mechanism in the pathway between their insecurity in the interparental relationship and their disruptive behavior problems. Using a multimethod, multi-informant design, 201 two-year-old children and their mothers participated in 3 annual…

Rho-Isp Revisited and Basic Stage Mass Estimating for Launch Vehicle Conceptual Sizing Studies

NASA Technical Reports Server (NTRS)

Kibbey, Timothy P.

2015-01-01

The ideal rocket equation is manipulated to demonstrate the essential link between propellant density and specific impulse as the two primary stage performance drivers for a launch vehicle. This is illustrated by examining volume-limited stages such as first stages and boosters. This proves to be a good approximation for first-order or Phase A vehicle design studies for solid rocket motors and for liquid stages, except when comparing to hydrogen-fueled stages. A next-order mass model is developed that is able to model the mass differences between hydrogen-fueled and other stages. Propellants considered range in density from liquid methane to inhibited red fuming nitric acid. Calculated comparisons are shown for solid rocket boosters, liquid first stages, liquid upper stages, and a balloon-deployed single-stage-to-orbit concept. The derived relationships are ripe for inclusion in a multi-stage design space exploration and optimization algorithm, as well as for single-parameter comparisons such as those shown herein.

Epigenome-Wide Association Study Identifies Cardiac Gene Patterning and a Novel Class of Biomarkers for Heart Failure.

PubMed

Meder, Benjamin; Haas, Jan; Sedaghat-Hamedani, Farbod; Kayvanpour, Elham; Frese, Karen; Lai, Alan; Nietsch, Rouven; Scheiner, Christina; Mester, Stefan; Bordalo, Diana Martins; Amr, Ali; Dietrich, Carsten; Pils, Dietmar; Siede, Dominik; Hund, Hauke; Bauer, Andrea; Holzer, Daniel Benjamin; Ruhparwar, Arjang; Mueller-Hennessen, Matthias; Weichenhan, Dieter; Plass, Christoph; Weis, Tanja; Backs, Johannes; Wuerstle, Maximilian; Keller, Andreas; Katus, Hugo A; Posch, Andreas E

2017-10-17

Biochemical DNA modification resembles a crucial regulatory layer among genetic information, environmental factors, and the transcriptome. To identify epigenetic susceptibility regions and novel biomarkers linked to myocardial dysfunction and heart failure, we performed the first multi-omics study in myocardial tissue and blood of patients with dilated cardiomyopathy and controls. Infinium human methylation 450 was used for high-density epigenome-wide mapping of DNA methylation in left-ventricular biopsies and whole peripheral blood of living probands. RNA deep sequencing was performed on the same samples in parallel. Whole-genome sequencing of all patients allowed exclusion of promiscuous genotype-induced methylation calls. In the screening stage, we detected 59 epigenetic loci that are significantly associated with dilated cardiomyopathy (false discovery corrected P ≤0.05), with 3 of them reaching epigenome-wide significance at P ≤5×10 -8 . Twenty-seven (46%) of these loci could be replicated in independent cohorts, underlining the role of epigenetic regulation of key cardiac transcription regulators. Using a staged multi-omics study design, we link a subset of 517 epigenetic loci with dilated cardiomyopathy and cardiac gene expression. Furthermore, we identified distinct epigenetic methylation patterns that are conserved across tissues, rendering these CpGs novel epigenetic biomarkers for heart failure. The present study provides to our knowledge the first epigenome-wide association study in living patients with heart failure using a multi-omics approach. © 2017 American Heart Association, Inc.

Development of Effective Teacher Program: Teamwork Building Program for Thailand's Municipal Schools

ERIC Educational Resources Information Center

Chantathai, Pimpka; Tesaputa, Kowat; Somprach, Kanokorn

2015-01-01

This research is aimed to formulate the effective teacher teamwork program in municipal schools in Thailand. Primary survey on current situation and problem was conducted to develop the plan to suggest potential programs. Samples were randomly selected from municipal schools by using multi-stage sampling method in order to investigate their…

The Impact of Education on Rural Women's Participation in Political and Economic Activities

ERIC Educational Resources Information Center

Bishaw, Alemayehu

2014-01-01

This study endeavored to investigate the impact of education on rural women's participation in political and economic activities. Six hundred rural women and 12 gender Activists were selected for this study from three Zones of Amhara Region, Ethiopia using multi-stage random sampling technique and purposeful sampling techniques respectively.…

Enhancing Argumentative Writing Skill through Contextual Teaching and Learning

ERIC Educational Resources Information Center

Hasani, Aceng

2016-01-01

This study aims to describe the influence of contextual learning model and critical thinking ability toward argumentative writing skill on university students. The population of the research was 147 university students, and 52 university students were used as sample with multi stage sampling. The results of the research indicate that; group of…

Parametric Modeling Investigation of a Radially-Staged Low-Emission Aviation Combustor

NASA Technical Reports Server (NTRS)

Heath, Christopher M.

2016-01-01

Aviation gas-turbine combustion demands high efficiency, wide operability and minimal trace gas emissions. Performance critical design parameters include injector geometry, combustor layout, fuel-air mixing and engine cycle conditions. The present investigation explores these factors and their impact on a radially staged low-emission aviation combustor sized for a next-generation 24,000-lbf-thrust engine. By coupling multi-fidelity computational tools, a design exploration was performed using a parameterized annular combustor sector at projected 100% takeoff power conditions. Design objectives included nitrogen oxide emission indices and overall combustor pressure loss. From the design space, an optimal configuration was selected and simulated at 7.1, 30 and 85% part-power operation, corresponding to landing-takeoff cycle idle, approach and climb segments. All results were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Species concentrations were solved directly using a reduced 19-step reaction mechanism for Jet-A. Turbulence closure was obtained using a nonlinear K-epsilon model. This research demonstrates revolutionary combustor design exploration enabled by multi-fidelity physics-based simulation.

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction.

PubMed

Granovsky, Alexander A

2015-12-21

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction

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

Granovsky, Alexander A., E-mail: alex.granovsky@gmail.com

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

Designing multi-targeted agents: An emerging anticancer drug discovery paradigm.

PubMed

Fu, Rong-Geng; Sun, Yuan; Sheng, Wen-Bing; Liao, Duan-Fang

2017-08-18

The dominant paradigm in drug discovery is to design ligands with maximum selectivity to act on individual drug targets. With the target-based approach, many new chemical entities have been discovered, developed, and further approved as drugs. However, there are a large number of complex diseases such as cancer that cannot be effectively treated or cured only with one medicine to modulate the biological function of a single target. As simultaneous intervention of two (or multiple) cancer progression relevant targets has shown improved therapeutic efficacy, the innovation of multi-targeted drugs has become a promising and prevailing research topic and numerous multi-targeted anticancer agents are currently at various developmental stages. However, most multi-pharmacophore scaffolds are usually discovered by serendipity or screening, while rational design by combining existing pharmacophore scaffolds remains an enormous challenge. In this review, four types of multi-pharmacophore modes are discussed, and the examples from literature will be used to introduce attractive lead compounds with the capability of simultaneously interfering with different enzyme or signaling pathway of cancer progression, which will reveal the trends and insights to help the design of the next generation multi-targeted anticancer agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Electrophysiology Tool Construction

PubMed Central

Ide, David

2016-01-01

This protocol documents the construction of a custom microscope stage system currently in widespread use by a wide variety of investigators. The current design and construction of this stage is the result of multiple iterations, integrating input from a number of electrophysiologists working with a variety of preparations. Thus, this tool is a generally applicable solution, suitable for a wide array of end-user requirements; its flexible design facilitates rapid and easy configuration, making it useful for multi-user microscopes, as individual researchers can reconfigure the stage system or have their own readily replaceable stage plates. Furthermore, the stage can be manufactured using equipment typically found in small research machine shops, and by keeping the various parts on hand, machinists can quickly satisfy new requests and/or modifications for a wide variety of applications. PMID:23315946

Design of multi-mission chemical propulsion modules for planetary orbiters. Volume 1: Summary report

NASA Technical Reports Server (NTRS)

1975-01-01

Results are presented of a conceptual design and feasibility study of chemical propulsion stages that can serve as modular propulsion units, with little or no modification, on a variety of planetary orbit missions, including orbiters of Mercury, Saturn, and Uranus. Planetary spacecraft of existing design or currently under development, viz., spacecraft of the Pioneer and Mariner families, are assumed as payload vehicles. Thus, operating requirements of spin-stabilized and 3-axis stabilized spacecraft have to be met by the respective propulsion module designs. As launch vehicle for these missions the Shuttle orbiter and interplanetary injection stage, or Tug, plus solid-propellant kick motor was assumed. Accommodation constraints and interfaces involving the payloads and the launch vehicle are considered in the propulsion module design. The applicability and performance advantages were evaluated of the space-storable high-energy bipropellants. The incentive for using this advanced propulsion technology on planetary missions is the much greater performance potential when orbit insertion velocities in excess of 4 km/sec are required, as in the Mercury orbiter. Design analyses and performance tradeoffs regarding earth-storable versus space-storable propulsion systems are included. Cost and development schedules of multi-mission versus custom-designed propulsion modules are examined.

Fundamental Design based on Current Distribution in Coaxial Multi-Layer Cable-in-Conduit Conductor

NASA Astrophysics Data System (ADS)

Hamajima, Takataro; Tsuda, Makoto; Yagai, Tsuyoshi; Takahata, Kazuya; Imagawa, Shinsaku

An imbalanced current distribution is often observed in cable-in-conduit (CIC) superconductors which are composed of multi-staged, triplet type sub-cables, and hence deteriorates the performance of the coils. Therefore, since it is very important to obtain a homogeneous current distribution in the superconducting strands, we propose a coaxial multi-layer type CIC conductor. We use a circuit model for all layers in the coaxial multi-layer CIC conductor, and derive a generalized formula governing the current distribution as explicit functions of the superconductor construction parameters, such as twist pitch, twist direction, radius of each layer, and number of superconducting (SC) strands and copper (Cu) strands. We apply the formula to design the coaxial multi-layer CIC which has the same number of SC strands and Cu strands of the CIC for Central Solenoid of ITER. We can design three kinds of the coaxial multi-layer CIC depending on distribution of SC and Cu strands on all layers. It is shown that the SC strand volume should be optimized as a function of SC and Cu strand distribution on the layers.

Noncontact Sleep Study by Multi-Modal Sensor Fusion.

PubMed

Chung, Ku-Young; Song, Kwangsub; Shin, Kangsoo; Sohn, Jinho; Cho, Seok Hyun; Chang, Joon-Hyuk

2017-07-21

Polysomnography (PSG) is considered as the gold standard for determining sleep stages, but due to the obtrusiveness of its sensor attachments, sleep stage classification algorithms using noninvasive sensors have been developed throughout the years. However, the previous studies have not yet been proven reliable. In addition, most of the products are designed for healthy customers rather than for patients with sleep disorder. We present a novel approach to classify sleep stages via low cost and noncontact multi-modal sensor fusion, which extracts sleep-related vital signals from radar signals and a sound-based context-awareness technique. This work is uniquely designed based on the PSG data of sleep disorder patients, which were received and certified by professionals at Hanyang University Hospital. The proposed algorithm further incorporates medical/statistical knowledge to determine personal-adjusted thresholds and devise post-processing. The efficiency of the proposed algorithm is highlighted by contrasting sleep stage classification performance between single sensor and sensor-fusion algorithms. To validate the possibility of commercializing this work, the classification results of this algorithm were compared with the commercialized sleep monitoring device, ResMed S+. The proposed algorithm was investigated with random patients following PSG examination, and results show a promising novel approach for determining sleep stages in a low cost and unobtrusive manner.

Noncontact Sleep Study by Multi-Modal Sensor Fusion

PubMed Central

Chung, Ku-young; Song, Kwangsub; Shin, Kangsoo; Sohn, Jinho; Cho, Seok Hyun; Chang, Joon-Hyuk

2017-01-01

Polysomnography (PSG) is considered as the gold standard for determining sleep stages, but due to the obtrusiveness of its sensor attachments, sleep stage classification algorithms using noninvasive sensors have been developed throughout the years. However, the previous studies have not yet been proven reliable. In addition, most of the products are designed for healthy customers rather than for patients with sleep disorder. We present a novel approach to classify sleep stages via low cost and noncontact multi-modal sensor fusion, which extracts sleep-related vital signals from radar signals and a sound-based context-awareness technique. This work is uniquely designed based on the PSG data of sleep disorder patients, which were received and certified by professionals at Hanyang University Hospital. The proposed algorithm further incorporates medical/statistical knowledge to determine personal-adjusted thresholds and devise post-processing. The efficiency of the proposed algorithm is highlighted by contrasting sleep stage classification performance between single sensor and sensor-fusion algorithms. To validate the possibility of commercializing this work, the classification results of this algorithm were compared with the commercialized sleep monitoring device, ResMed S+. The proposed algorithm was investigated with random patients following PSG examination, and results show a promising novel approach for determining sleep stages in a low cost and unobtrusive manner. PMID:28753994

Modeling of Aerosols in Post-Combustor Flow Path and Sampling System

NASA Technical Reports Server (NTRS)

Wey, Thomas; Liu, Nan-Suey

2006-01-01

The development and application of a multi-dimensional capability for modeling and simulation of aviation-sourced particle emissions and their precursors are elucidated. Current focus is on the role of the flow and thermal environments. The cases investigated include a film cooled turbine blade, the first-stage of a high-pressure turbine, the sampling probes, the sampling lines, and a pressure reduction chamber.

Sipa1l1 is an early biomarker of liver fibrosis in CCl4-treated rats

PubMed Central

Marfà, Santiago; Morales-Ruiz, Manuel; Oró, Denise; Ribera, Jordi; Fernández-Varo, Guillermo; Jiménez, Wladimiro

2016-01-01

ABSTRACT At present, several procedures are used for staging liver fibrosis. However, these methods may involve clinical complications and/or present diagnostic uncertainty mainly in the early stages of the disease. Thus, this study was designed to unveil new non-invasive biomarkers of liver fibrosis in an in vivo model of fibrosis/cirrhosis induction by CCl4 inhalation by using a label-free quantitative LC-MS/MS approach. We analyzed 94 serum samples from adult Wistar rats with different degrees of liver fibrosis and 36 control rats. Firstly, serum samples from 18 CCl4-treated rats were clustered into three different groups according to the severity of hepatic and the serum proteome was characterized by label-free LC-MS/MS. Furthermore, three different pooled serum samples obtained from 16 control Wistar rats were also analyzed. Based on the proteomic data obtained, we performed a multivariate analysis which displayed three main cell signaling pathways altered in fibrosis. In cirrhosis, more biological imbalances were detected as well as multi-organ alterations. In addition, hemopexin and signal-induced proliferation-associated 1 like 1 (SIPA1L1) were selected as potential serum markers of liver fibrogenesis among all the analyzed proteins. The results were validated by ELISA in an independent group of 76 fibrotic/cirrhotic rats and 20 controls which confirmed SIPA1L1 as a potential non-invasive biomarker of liver fibrosis. In particular, SIPA1L1 showed a clear diminution in serum samples from fibrotic/cirrhotic rats and a great accuracy at identifying early fibrotic stages. In conclusion, the proteomic analysis of serum samples from CCl4-treated rats has enabled the identification of SIPA1L1 as a non-invasive marker of early liver fibrosis. PMID:27230648

The Cambridge Centre for Ageing and Neuroscience (Cam-CAN) data repository: Structural and functional MRI, MEG, and cognitive data from a cross-sectional adult lifespan sample.

PubMed

Taylor, Jason R; Williams, Nitin; Cusack, Rhodri; Auer, Tibor; Shafto, Meredith A; Dixon, Marie; Tyler, Lorraine K; Cam-Can; Henson, Richard N

2017-01-01

This paper describes the data repository for the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) initial study cohort. The Cam-CAN Stage 2 repository contains multi-modal (MRI, MEG, and cognitive-behavioural) data from a large (approximately N=700), cross-sectional adult lifespan (18-87years old) population-based sample. The study is designed to characterise age-related changes in cognition and brain structure and function, and to uncover the neurocognitive mechanisms that support healthy cognitive ageing. The database contains raw and preprocessed structural MRI, functional MRI (active tasks and resting state), and MEG data (active tasks and resting state), as well as derived scores from cognitive behavioural experiments spanning five broad domains (attention, emotion, action, language, and memory), and demographic and neuropsychological data. The dataset thus provides a depth of neurocognitive phenotyping that is currently unparalleled, enabling integrative analyses of age-related changes in brain structure, brain function, and cognition, and providing a testbed for novel analyses of multi-modal neuroimaging data. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A Gas-Spring-Loaded X-Y-Z Stage System for X-ray Microdiffraction Sample Manipulation

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

Shu Deming; Cai Zhonghou; Lai, Barry

2007-01-19

We have designed and constructed a gas-spring-loaded x-y-z stage system for x-ray microdiffraction sample manipulation at the Advanced Photon Source XOR 2-ID-D station. The stage system includes three DC-motor-driven linear stages and a gas-spring-based heavy preloading structure, which provides antigravity forces to ensure that the stage system keeps high-positioning performance under variable goniometer orientation. Microdiffraction experiments with this new stage system showed significant sample manipulation performance improvement.

A Gas-Spring-Loaded X-Y-Z Stage System for X-ray Microdiffraction Sample Manipulation

NASA Astrophysics Data System (ADS)

Shu, Deming; Cai, Zhonghou; Lai, Barry

2007-01-01

We have designed and constructed a gas-spring-loaded x-y-z stage system for x-ray microdiffraction sample manipulation at the Advanced Photon Source XOR 2-ID-D station. The stage system includes three DC-motor-driven linear stages and a gas-spring-based heavy preloading structure, which provides antigravity forces to ensure that the stage system keeps high-positioning performance under variable goniometer orientation. Microdiffraction experiments with this new stage system showed significant sample manipulation performance improvement.

NASA Ares I Crew Launch Vehicle Upper Stage Overview

NASA Technical Reports Server (NTRS)

Davusm Daniel J.; McArthur, J. Craig

2008-01-01

By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA's Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program's transportation system.

Pulsed depressed collector

DOEpatents

Kemp, Mark A

2015-11-03

A high power RF device has an electron beam cavity, a modulator, and a circuit for feed-forward energy recovery from a multi-stage depressed collector to the modulator. The electron beam cavity include a cathode, an anode, and the multi-stage depressed collector, and the modulator is configured to provide pulses to the cathode. Voltages of the electrode stages of the multi-stage depressed collector are allowed to float as determined by fixed impedances seen by the electrode stages. The energy recovery circuit includes a storage capacitor that dynamically biases potentials of the electrode stages of the multi-stage depressed collector and provides recovered energy from the electrode stages of the multi-stage depressed collector to the modulator. The circuit may also include a step-down transformer, where the electrode stages of the multi-stage depressed collector are electrically connected to separate taps on the step-down transformer.

Mechanical System Analysis/Design Tool (MSAT) Quick Guide

NASA Technical Reports Server (NTRS)

Lee, HauHua; Kolb, Mark; Madelone, Jack

1998-01-01

MSAT is a unique multi-component multi-disciplinary tool that organizes design analysis tasks around object-oriented representations of configuration components, analysis programs and modules, and data transfer links between them. This creative modular architecture enables rapid generation of input stream for trade-off studies of various engine configurations. The data transfer links automatically transport output from one application as relevant input to the next application once the sequence is set up by the user. The computations are managed via constraint propagation - the constraints supplied by the user as part of any optimization module. The software can be used in the preliminary design stage as well as during the detail design of product development process.

Principles in sampling design, lessons, and recommendations from a multi-year, multi-port surveillance program in Lake Superior

EPA Science Inventory

We evaluated a pilot aquatic invasive species (AIS) early detection monitoring program in Lake Superior that was designed to detect newly-introduced fishes. We established survey protocols for three major ports (Duluth-Superior, Sault Ste. Marie, Thunder Bay), and designed an ada...

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

PubMed Central

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana; Senor, David; Steckbeck, Mackenzie; Davis, Justin; Doyle, Barney; Buller, Daniel

2017-01-01

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2. PMID:28961199

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

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

Taylor, Caitlin; Bufford, Daniel; Muntifering, Brittany

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due tomore » irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2.« less

The Relationship between Utilization of Computer Games and Spatial Abilities among High School Students

ERIC Educational Resources Information Center

Motamedi, Vahid; Yaghoubi, Razeyah Mohagheghyan

2015-01-01

This study aimed at investigating the relationship between computer game use and spatial abilities among high school students. The sample consisted of 300 high school male students selected through multi-stage cluster sampling. Data gathering tools consisted of a researcher made questionnaire (to collect information on computer game usage) and the…

Socio-Economic Background and Access to Internet as Correlates of Students' Achievement in Agricultural Science

ERIC Educational Resources Information Center

Adegoke, Sunday Paul; Osokoya, Modupe M.

2015-01-01

This study investigated access to internet and socio-economic background as correlates of students' achievement in Agricultural Science among selected Senior Secondary Schools Two Students in Ogbomoso South and North Local Government Areas. The study adopted multi-stage sampling technique. Simple random sampling was used to select 30 students from…

Lower-Order Compensation Chain Threshold-Reduction Technique for Multi-Stage Voltage Multipliers.

PubMed

Dell' Anna, Francesco; Dong, Tao; Li, Ping; Wen, Yumei; Azadmehr, Mehdi; Casu, Mario; Berg, Yngvar

2018-04-17

This paper presents a novel threshold-compensation technique for multi-stage voltage multipliers employed in low power applications such as passive and autonomous wireless sensing nodes (WSNs) powered by energy harvesters. The proposed threshold-reduction technique enables a topological design methodology which, through an optimum control of the trade-off among transistor conductivity and leakage losses, is aimed at maximizing the voltage conversion efficiency (VCE) for a given ac input signal and physical chip area occupation. The conducted simulations positively assert the validity of the proposed design methodology, emphasizing the exploitable design space yielded by the transistor connection scheme in the voltage multiplier chain. An experimental validation and comparison of threshold-compensation techniques was performed, adopting 2N5247 N-channel junction field effect transistors (JFETs) for the realization of the voltage multiplier prototypes. The attained measurements clearly support the effectiveness of the proposed threshold-reduction approach, which can significantly reduce the chip area occupation for a given target output performance and ac input signal.

The Center for HIV/AIDS Vaccine Immunology (CHAVI) Multi-site Quality Assurance Program for Cryopreserved Human Peripheral Blood Mononuclear Cells

PubMed Central

Sarzotti-Kelsoe, Marcella; Needham, Leila K.; Rountree, Wes; Bainbridge, John; Gray, Clive M.; Fiscus, Susan A.; Ferrari, Guido; Stevens, Wendy S.; Stager, Susan L.; Binz, Whitney; Louzao, Raul; Long, Kristy O.; Mokgotho, Pauline; Moodley, Niranjini; Mackay, Melanie; Kerkau, Melissa; McMillion, Takesha; Kirchherr, Jennifer; Soderberg, Kelly A.; Haynes, Barton F.; Denny, Thomas N.

2014-01-01

The Center for HIV/AIDS Vaccine Immunology (CHAVI) consortium was established to determine the host and virus factors associated with HIV transmission, infection and containment of virus replication, with the goal of advancing the development of an HIV protective vaccine. Studies to meet this goal required the use of cryopreserved Peripheral Blood Mononuclear Cell (PBMC) specimens, and therefore it was imperative that a quality assurance (QA) oversight program be developed to monitor PBMC samples obtained from study participants at multiple international sites. Nine site-affiliated laboratories in Africa and the USA collected and processed PBMCs, and cryopreserved PBMC were shipped to CHAVI repositories in Africa and the USA for long-term storage. A three-stage program was designed, based on Good Clinical Laboratory Practices (GCLP), to monitor PBMC integrity at each step of this process. The first stage evaluated the integrity of fresh PBMCs for initial viability, overall yield, and processing time at the site-affiliated laboratories (Stage 1); for the second stage, the repositories determined post-thaw viability and cell recovery of cryopreserved PBMC, received from the site-affiliated laboratories (Stage 2); the third stage assessed the long-term specimen storage at each repository (Stage 3). Overall, the CHAVI PBMC QA oversight program results highlight the relative importance of each of these stages to the ultimate goal of preserving specimen integrity from peripheral blood collection to long-term repository storage. PMID:24910414

Obstructive sleep apnea alters sleep stage transition dynamics.

PubMed

Bianchi, Matt T; Cash, Sydney S; Mietus, Joseph; Peng, Chung-Kang; Thomas, Robert

2010-06-28

Enhanced characterization of sleep architecture, compared with routine polysomnographic metrics such as stage percentages and sleep efficiency, may improve the predictive phenotyping of fragmented sleep. One approach involves using stage transition analysis to characterize sleep continuity. We analyzed hypnograms from Sleep Heart Health Study (SHHS) participants using the following stage designations: wake after sleep onset (WASO), non-rapid eye movement (NREM) sleep, and REM sleep. We show that individual patient hypnograms contain insufficient number of bouts to adequately describe the transition kinetics, necessitating pooling of data. We compared a control group of individuals free of medications, obstructive sleep apnea (OSA), medical co-morbidities, or sleepiness (n = 374) with mild (n = 496) or severe OSA (n = 338). WASO, REM sleep, and NREM sleep bout durations exhibited multi-exponential temporal dynamics. The presence of OSA accelerated the "decay" rate of NREM and REM sleep bouts, resulting in instability manifesting as shorter bouts and increased number of stage transitions. For WASO bouts, previously attributed to a power law process, a multi-exponential decay described the data well. Simulations demonstrated that a multi-exponential process can mimic a power law distribution. OSA alters sleep architecture dynamics by decreasing the temporal stability of NREM and REM sleep bouts. Multi-exponential fitting is superior to routine mono-exponential fitting, and may thus provide improved predictive metrics of sleep continuity. However, because a single night of sleep contains insufficient transitions to characterize these dynamics, extended monitoring of sleep, probably at home, would be necessary for individualized clinical application.

Inspection logistics planning for multi-stage production systems with applications to semiconductor fabrication lines

NASA Astrophysics Data System (ADS)

Chen, Kyle Dakai

Since the market for semiconductor products has become more lucrative and competitive, research into improving yields for semiconductor fabrication lines has lately received a tremendous amount of attention. One of the most critical tasks in achieving such yield improvements is to plan the in-line inspection sampling efficiently so that any potential yield problems can be detected early and eliminated quickly. We formulate a multi-stage inspection planning model based on configurations in actual semiconductor fabrication lines, specifically taking into account both the capacity constraint and the congestion effects at the inspection station. We propose a new mixed First-Come-First-Serve (FCFS) and Last-Come-First-Serve (LCFS) discipline for serving the inspection samples to expedite the detection of potential yield problems. Employing this mixed FCFS and LCFS discipline, we derive approximate expressions for the queueing delays in yield problem detection time and develop near-optimal algorithms to obtain the inspection logistics planning policies. We also investigate the queueing performance with this mixed type of service discipline under different assumptions and configurations. In addition, we conduct numerical tests and generate managerial insights based on input data from actual semiconductor fabrication lines. To the best of our knowledge, this research is novel in developing, for the first time in the literature, near-optimal results for inspection logistics planning in multi-stage production systems with congestion effects explicitly considered.

Stochastic Multi-Commodity Facility Location Based on a New Scenario Generation Technique

NASA Astrophysics Data System (ADS)

Mahootchi, M.; Fattahi, M.; Khakbazan, E.

2011-11-01

This paper extends two models for stochastic multi-commodity facility location problem. The problem is formulated as two-stage stochastic programming. As a main point of this study, a new algorithm is applied to efficiently generate scenarios for uncertain correlated customers' demands. This algorithm uses Latin Hypercube Sampling (LHS) and a scenario reduction approach. The relation between customer satisfaction level and cost are considered in model I. The risk measure using Conditional Value-at-Risk (CVaR) is embedded into the optimization model II. Here, the structure of the network contains three facility layers including plants, distribution centers, and retailers. The first stage decisions are the number, locations, and the capacity of distribution centers. In the second stage, the decisions are the amount of productions, the volume of transportation between plants and customers.

Identification of a New Susceptibility Locus for Systemic Lupus Erythematosus on Chromosome 12 in Individuals of European Ancestry

PubMed Central

Demirci, F. Yesim; Wang, Xingbin; Kelly, Jennifer A.; Morris, David L.; Barmada, M. Michael; Feingold, Eleanor; Kao, Amy H.; Sivils, Kathy L.; Bernatsky, Sasha; Pineau, Christian; Clarke, Ann; Ramsey-Goldman, Rosalind; Vyse, Timothy J.; Gaffney, Patrick M.; Manzi, Susan; Kamboh, M. Ilyas

2016-01-01

Objective Genome-wide association studies (GWASs) in individuals of European ancestry identified a number of systemic lupus erythematosus (SLE) susceptibility loci using earlier versions of high-density genotyping platforms. Follow-up studies on suggestive GWAS regions using larger samples and more markers identified additional SLE loci in European-descent subjects. Here we report the results of a multi-stage study that we performed to identify novel SLE loci. Methods In Stage 1, we conducted a new GWAS of SLE in a North American case-control sample of European ancestry (n=1,166) genotyped on Affymetrix Genome-Wide Human SNP Array 6.0. In Stage 2, we further investigated top new suggestive GWAS hits by in silico evaluation and meta-analysis using an additional dataset of European-descent subjects (>2,500 individuals), followed by replication of top meta-analysis findings in another dataset of European-descent subjects (>10,000 individuals) in Stage 3. Results As expected, our GWAS revealed most significant associations at the major histocompatibility complex locus (6p21), which easily surpassed genome-wide significance threshold (P<5×10−8). Several other SLE signals/loci previously implicated in Caucasians and/or Asians were also supported in Stage 1 discovery sample and strongest signals were observed at 2q32/STAT4 (P=3.6×10−7) and at 8p23/BLK (P=8.1×10−6). Stage 2 meta-analyses identified a new genome-wide significant SLE locus at 12q12 (meta P=3.1×10−8), which was replicated in Stage 3. Conclusion Our multi-stage study identified and replicated a new SLE locus that warrants further follow-up in additional studies. Publicly available databases suggest that this new SLE signal falls within a functionally relevant genomic region and near biologically important genes. PMID:26316170

Novel microfabrication stage allowing for one-photon and multi-photon light assisted molecular immobilization and for multi-photon microscope

NASA Astrophysics Data System (ADS)

Gonçalves, Odete; Snider, Scott; Zadoyan, Ruben; Nguyen, Quoc-Thang; Vorum, Henrik; Petersen, Steffen B.; Neves-Petersen, Maria Teresa

2017-02-01

Light Assisted Molecular Immobilization (LAMI) results in spatially oriented and localized covalent coupling of biomolecules onto thiol reactive surfaces. LAMI is possible due to the conserved spatial proximity between aromatic residues and disulfide bridges in proteins. When aromatic residues are excited with UV light (275-295nm), disulphide bridges are disrupted and the formed thiol groups covalently bind to surfaces. Immobilization hereby reported is achieved in a microfabrication stage coupled to a fs-laser, through one- or multi-photon excitation. The fundamental 840nm output is tripled to 280nm and focused onto the sample, leading to one-photon excitation and molecular immobilization. The sample rests on a xyz-stage with micrometer step resolution and is illuminated according to a pattern uploaded to the software controlling the stage and the shutter. Molecules are immobilized according to such pattern, with micrometer spatial resolution. Spatial masks inserted in the light path lead to light diffraction patterns used to immobilize biomolecules with submicrometer spatial resolution. Light diffraction patterns are imaged by an inbuilt microscope. Two-photon microscopy and imaging of the fluorescent microbeads is shown. Immobilization of proteins, e.g. C-reactive protein, and of an engineered molecular beacon has been successfully achieved. The beacon was coupled to a peptide containing a disulfide bridge neighboring a tryptophan residue, being this way possible to immobilize the beacon on a surface using one-photon LAMI. This technology is being implemented in the creation of point-of-care biosensors aiming at the detection of cancer and cardiovascular disease markers.

SEMIPARAMETRIC ADDITIVE RISKS REGRESSION FOR TWO-STAGE DESIGN SURVIVAL STUDIES

PubMed Central

Li, Gang; Wu, Tong Tong

2011-01-01

In this article we study a semiparametric additive risks model (McKeague and Sasieni (1994)) for two-stage design survival data where accurate information is available only on second stage subjects, a subset of the first stage study. We derive two-stage estimators by combining data from both stages. Large sample inferences are developed. As a by-product, we also obtain asymptotic properties of the single stage estimators of McKeague and Sasieni (1994) when the semiparametric additive risks model is misspecified. The proposed two-stage estimators are shown to be asymptotically more efficient than the second stage estimators. They also demonstrate smaller bias and variance for finite samples. The developed methods are illustrated using small intestine cancer data from the SEER (Surveillance, Epidemiology, and End Results) Program. PMID:21931467

Determinants of customers' intention to participate in a Korean restaurant health promotion program: an application of the theory of planned behavior.

PubMed

Hong, Kyungeui; Gittelsohn, Joel; Joung, Hyojee

2010-06-01

The purpose of this study was to investigate the effects of personal characteristics and theory of planned behavior (TPB) constructs on the intention to participate in a restaurant health promotion program. In total, 830 adults residing in Seoul were sampled by a multi-stage cluster and random sampling design. Data were collected from a structured self-administered questionnaire, which covered variables concerning demographics, health status and TPB constructs including attitude, subjective norm and perceived behavioral control. A path analysis combining personal characteristics and TPB constructs was used to investigate determinants of the customers' intention. Positive and negative attitudes, subjective norms and perceived behavioral control directly affected the intention to participate. Demographics and health status both directly and indirectly affected the intention to participate. This study identifies personal characteristics and TPB constructs that are important to planning and implementing a restaurant health promotion program.

Experimental Results of the First Two Stages of an Advanced Transonic Core Compressor Under Isolated and Multi-Stage Conditions

NASA Technical Reports Server (NTRS)

Prahst, Patricia S.; Kulkarni, Sameer; Sohn, Ki H.

2015-01-01

NASA's Environmentally Responsible Aviation (ERA) Program calls for investigation of the technology barriers associated with improved fuel efficiency of large gas turbine engines. Under ERA the task for a High Pressure Ratio Core Technology program calls for a higher overall pressure ratio of 60 to 70. This mean that the HPC would have to almost double in pressure ratio and keep its high level of efficiency. The challenge is how to match the corrected mass flow rate of the front two supersonic high reaction and high corrected tip speed stages with a total pressure ratio of 3.5. NASA and GE teamed to address this challenge by using the initial geometry of an advanced GE compressor design to meet the requirements of the first 2 stages of the very high pressure ratio core compressor. The rig was configured to run as a 2 stage machine, with Strut and IGV, Rotor 1 and Stator 1 run as independent tests which were then followed by adding the second stage. The goal is to fully understand the stage performances under isolated and multi-stage conditions and fully understand any differences and provide a detailed aerodynamic data set for CFD validation. Full use was made of steady and unsteady measurement methods to isolate fluid dynamics loss source mechanisms due to interaction and endwalls. The paper will present the description of the compressor test article, its predicted performance and operability, and the experimental results for both the single stage and two stage configurations. We focus the detailed measurements on 97 and 100 of design speed at 3 vane setting angles.

Method and apparatus for converting and removing organosulfur and other oxidizable compounds from distillate fuels, and compositions obtained thereby

DOEpatents

D'Alessandro, Robert N.; Tarabocchia, John; Jones, Jerald Andrew; Bonde, Steven E.; Leininger, Stefan

2010-10-26

The present disclosure is directed to a multi-stage system and a process utilizing said system with the design of reducing the sulfur-content in a liquid comprising hydrocarbons and organosulfur compounds. The process comprising at least one of the following states: (1) an oxidation stage; (2) an extraction state; (3) a raffinate washing stage; (4) a raffinate polishing stage; (5) a solvent recovery stage; (6) a solvent purification stage; and (7) a hydrocarbon recovery stage. The process for removing sulfur-containing hydrocarbons from gas oil, which comprises oxidizing gas oil comprising hydrocarbons and organosulfur compounds to obtain a product gas oil.

Multi-hazard evacuation route and shelter planning for buildings.

DOT National Transportation Integrated Search

2014-06-01

A bi-level, two-stage, binary stochastic program with equilibrium constraints, and three variants, are presented that : support the planning and design of shelters and exits, along with hallway fortification strategies and associated : evacuation pat...

Development of a Multiple-Stage Differential Mobility Analyzer (MDMA)

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

Chen, Da-Ren; Cheng, Mengdawn

2007-01-01

A new DMA column has been designed with the capability of simultaneously extracting monodisperse particles of different sizes in multiple stages. We call this design a multistage DMA, or MDMA. A prototype MDMA has been constructed and experimentally evaluated in this study. The new column enables the fast measurement of particles in a wide size range, while preserving the powerful particle classification function of a DMA. The prototype MDMA has three sampling stages, capable of classifying monodisperse particles of three different sizes simultaneously. The scanning voltage operation of a DMA can be applied to this new column. Each stage ofmore » MDMA column covers a fraction of the entire particle size range to be measured. The covered size fractions of two adjacent stages of the MDMA are designed somewhat overlapped. The arrangement leads to the reduction of scanning voltage range and thus the cycling time of the measurement. The modular sampling stage design of the MDMA allows the flexible configuration of desired particle classification lengths and variable number of stages in the MDMA. The design of our MDMA also permits operation at high sheath flow, enabling high-resolution particle size measurement and/or reduction of the lower sizing limit. Using the tandem DMA technique, the performance of the MDMA, i.e., sizing accuracy, resolution, and transmission efficiency, was evaluated at different ratios of aerosol and sheath flowrates. Two aerosol sampling schemes were investigated. One was to extract aerosol flows at an evenly partitioned flowrate at each stage, and the other was to extract aerosol at a rate the same as the polydisperse aerosol flowrate at each stage. We detail the prototype design of the MDMA and the evaluation result on the transfer functions of the MDMA at different particle sizes and operational conditions.« less

Off-design Performance Analysis of Multi-Stage Transonic Axial Compressors

NASA Astrophysics Data System (ADS)

Du, W. H.; Wu, H.; Zhang, L.

Because of the complex flow fields and component interaction in modern gas turbine engines, they require extensive experiment to validate performance and stability. The experiment process can become expensive and complex. Modeling and simulation of gas turbine engines are way to reduce experiment costs, provide fidelity and enhance the quality of essential experiment. The flow field of a transonic compressor contains all the flow aspects, which are difficult to present-boundary layer transition and separation, shock-boundary layer interactions, and large flow unsteadiness. Accurate transonic axial compressor off-design performance prediction is especially difficult, due in large part to three-dimensional blade design and the resulting flow field. Although recent advancements in computer capacity have brought computational fluid dynamics to forefront of turbomachinery design and analysis, the grid and turbulence model still limit Reynolds-average Navier-Stokes (RANS) approximations in the multi-stage transonic axial compressor flow field. Streamline curvature methods are still the dominant numerical approach as an important tool for turbomachinery to analyze and design, and it is generally accepted that streamline curvature solution techniques will provide satisfactory flow prediction as long as the losses, deviation and blockage are accurately predicted.

Relationship Level of Individual Value Perceptions and Competence Beliefs of Classroom Teachers

ERIC Educational Resources Information Center

Kop, Yasar; Tasdan, Murat; Alibeyoglu, Aytekin

2017-01-01

The main aim of this study is to reveal classroom teachers' personal value perceptions and the level of their efficiencies. The quantitative research method was used in the research. The target population of the research consisted of 335 classroom teachers in Kars. Multi stage sampling model was selected in order to determine the sampling in the…

The Role of Socio-Cognitive Variables in Predicting Learning Satisfaction in Smart Schools

ERIC Educational Resources Information Center

Firoozi, Mohammad Reza; Kazemi, Ali; Jokar, Maryam

2017-01-01

The present study aimed to investigate the role of Socio-Cognitive variables in predicting learning satisfaction in Smart Schools. The population was all the primary school students studying in smart schools in the city of Shiraz in the school year 2014-2015. The sample, randomly chosen through multi-stage cluster sampling, was 383 primary school…

Teachers' Methodologies and Sources of Information on HIV/AIDS for Students with Visual Impairments in Selected Residential and Integrated Schools in Ghana

ERIC Educational Resources Information Center

Hayford, Samuel K.; Ocansey, Frederick

2017-01-01

This study reports part of a national survey on sources of information, education and communication materials on HIV/AIDS available to students with visual impairments in residential, segregated, and integrated schools in Ghana. A multi-staged stratified random sampling procedure and a purposive and simple random sampling approach, where…

The importance of structural softening for the evolution and architecture of passive margins

PubMed Central

Duretz, T.; Petri, B.; Mohn, G.; Schmalholz, S. M.; Schenker, F. L.; Müntener, O.

2016-01-01

Lithospheric extension can generate passive margins that bound oceans worldwide. Detailed geological and geophysical studies in present and fossil passive margins have highlighted the complexity of their architecture and their multi-stage deformation history. Previous modeling studies have shown the significant impact of coarse mechanical layering of the lithosphere (2 to 4 layer crust and mantle) on passive margin formation. We built upon these studies and design high-resolution (~100–300 m) thermo-mechanical numerical models that incorporate finer mechanical layering (kilometer scale) mimicking tectonically inherited heterogeneities. During lithospheric extension a variety of extensional structures arises naturally due to (1) structural softening caused by necking of mechanically strong layers and (2) the establishment of a network of weak layers across the deforming multi-layered lithosphere. We argue that structural softening in a multi-layered lithosphere is the main cause for the observed multi-stage evolution and architecture of magma-poor passive margins. PMID:27929057

Multi-stage decoding for multi-level block modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu

1991-01-01

In this paper, we investigate various types of multi-stage decoding for multi-level block modulation codes, in which the decoding of a component code at each stage can be either soft-decision or hard-decision, maximum likelihood or bounded-distance. Error performance of codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. Based on our study and computation results, we find that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. In particular, we find that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum decoding of the overall code is very small: only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

Estimating regression coefficients from clustered samples: Sampling errors and optimum sample allocation

NASA Technical Reports Server (NTRS)

Kalton, G.

1983-01-01

A number of surveys were conducted to study the relationship between the level of aircraft or traffic noise exposure experienced by people living in a particular area and their annoyance with it. These surveys generally employ a clustered sample design which affects the precision of the survey estimates. Regression analysis of annoyance on noise measures and other variables is often an important component of the survey analysis. Formulae are presented for estimating the standard errors of regression coefficients and ratio of regression coefficients that are applicable with a two- or three-stage clustered sample design. Using a simple cost function, they also determine the optimum allocation of the sample across the stages of the sample design for the estimation of a regression coefficient.

Design and implementation of a novel rotary micropositioning system driven by linear voice coil motor.

PubMed

Xu, Qingsong

2013-05-01

Limited-angle rotary micropositioning stages are required in precision engineering applications where an ultrahigh-precision rotational motion within a restricted range is needed. This paper presents the design, fabrication, and control of a compliant rotary micropositioning stage dedicated to the said applications. To tackle the challenge of achieving both a large rotational range and a compact size, a new idea of multi-stage compound radial flexure is proposed. A compact rotary stage is devised to deliver an over 10° rotational range while possessing a negligible magnitude of center shift. The stage is driven by a linear voice coil motor and its output motion is measured by laser displacement sensors. Analytical models are derived to facilitate the parametric design, which is validated by conducting finite element analysis. The actuation and sensing issues are addressed to guarantee the stage performance. A prototype is fabricated and a proportional-integral-derivative control is implemented to achieve a precise positioning. Experimental results demonstrate a resolution of 2 μrad over 10° rotational range as well as a low level of center shift of the rotary micropositioning system.

Recent advances in recombinant protein-based malaria vaccines

PubMed Central

Draper, Simon J.; Angov, Evelina; Horii, Toshihiro; Miller, Louis H.; Srinivasan, Prakash; Theisen, Michael; Biswas, Sumi

2015-01-01

Plasmodium parasites are the causative agent of human malaria, and the development of a highly effective vaccine against infection, disease and transmission remains a key priority. It is widely established that multiple stages of the parasite's complex lifecycle within the human host and mosquito vector are susceptible to vaccine-induced antibodies. The mainstay approach to antibody induction by subunit vaccination has been the delivery of protein antigen formulated in adjuvant. Extensive efforts have been made in this endeavor with respect to malaria vaccine development, especially with regard to target antigen discovery, protein expression platforms, adjuvant testing, and development of soluble and virus-like particle (VLP) delivery platforms. The breadth of approaches to protein-based vaccines is continuing to expand as innovative new concepts in next-generation subunit design are explored, with the prospects for the development of a highly effective multi-component/multi-stage/multi-antigen formulation seeming ever more likely. This review will focus on recent progress in protein vaccine design, development and/or clinical testing for a number of leading malaria antigens from the sporozoite-, merozoite- and sexual-stages of the parasite's lifecycle–including PfCelTOS, PfMSP1, PfAMA1, PfRH5, PfSERA5, PfGLURP, PfMSP3, Pfs48/45 and Pfs25. Future prospects and challenges for the development, production, human delivery and assessment of protein-based malaria vaccines are discussed. PMID:26458807

Multi-channel EEG-based sleep stage classification with joint collaborative representation and multiple kernel learning.

PubMed

Shi, Jun; Liu, Xiao; Li, Yan; Zhang, Qi; Li, Yingjie; Ying, Shihui

2015-10-30

Electroencephalography (EEG) based sleep staging is commonly used in clinical routine. Feature extraction and representation plays a crucial role in EEG-based automatic classification of sleep stages. Sparse representation (SR) is a state-of-the-art unsupervised feature learning method suitable for EEG feature representation. Collaborative representation (CR) is an effective data coding method used as a classifier. Here we use CR as a data representation method to learn features from the EEG signal. A joint collaboration model is established to develop a multi-view learning algorithm, and generate joint CR (JCR) codes to fuse and represent multi-channel EEG signals. A two-stage multi-view learning-based sleep staging framework is then constructed, in which JCR and joint sparse representation (JSR) algorithms first fuse and learning the feature representation from multi-channel EEG signals, respectively. Multi-view JCR and JSR features are then integrated and sleep stages recognized by a multiple kernel extreme learning machine (MK-ELM) algorithm with grid search. The proposed two-stage multi-view learning algorithm achieves superior performance for sleep staging. With a K-means clustering based dictionary, the mean classification accuracy, sensitivity and specificity are 81.10 ± 0.15%, 71.42 ± 0.66% and 94.57 ± 0.07%, respectively; while with the dictionary learned using the submodular optimization method, they are 80.29 ± 0.22%, 71.26 ± 0.78% and 94.38 ± 0.10%, respectively. The two-stage multi-view learning based sleep staging framework outperforms all other classification methods compared in this work, while JCR is superior to JSR. The proposed multi-view learning framework has the potential for sleep staging based on multi-channel or multi-modality polysomnography signals. Copyright © 2015 Elsevier B.V. All rights reserved.

Monitoring Powdery Mildew of Winter Wheat by Using Moderate Resolution Multi-Temporal Satellite Imagery

PubMed Central

Zhang, Jingcheng; Pu, Ruiliang; Yuan, Lin; Wang, Jihua; Huang, Wenjiang; Yang, Guijun

2014-01-01

Powdery mildew is one of the most serious diseases that have a significant impact on the production of winter wheat. As an effective alternative to traditional sampling methods, remote sensing can be a useful tool in disease detection. This study attempted to use multi-temporal moderate resolution satellite-based data of surface reflectances in blue (B), green (G), red (R) and near infrared (NIR) bands from HJ-CCD (CCD sensor on Huanjing satellite) to monitor disease at a regional scale. In a suburban area in Beijing, China, an extensive field campaign for disease intensity survey was conducted at key growth stages of winter wheat in 2010. Meanwhile, corresponding time series of HJ-CCD images were acquired over the study area. In this study, a number of single-stage and multi-stage spectral features, which were sensitive to powdery mildew, were selected by using an independent t-test. With the selected spectral features, four advanced methods: mahalanobis distance, maximum likelihood classifier, partial least square regression and mixture tuned matched filtering were tested and evaluated for their performances in disease mapping. The experimental results showed that all four algorithms could generate disease maps with a generally correct distribution pattern of powdery mildew at the grain filling stage (Zadoks 72). However, by comparing these disease maps with ground survey data (validation samples), all of the four algorithms also produced a variable degree of error in estimating the disease occurrence and severity. Further, we found that the integration of MTMF and PLSR algorithms could result in a significant accuracy improvement of identifying and determining the disease intensity (overall accuracy of 72% increased to 78% and kappa coefficient of 0.49 increased to 0.59). The experimental results also demonstrated that the multi-temporal satellite images have a great potential in crop diseases mapping at a regional scale. PMID:24691435

Monitoring powdery mildew of winter wheat by using moderate resolution multi-temporal satellite imagery.

PubMed

Zhang, Jingcheng; Pu, Ruiliang; Yuan, Lin; Wang, Jihua; Huang, Wenjiang; Yang, Guijun

2014-01-01

Powdery mildew is one of the most serious diseases that have a significant impact on the production of winter wheat. As an effective alternative to traditional sampling methods, remote sensing can be a useful tool in disease detection. This study attempted to use multi-temporal moderate resolution satellite-based data of surface reflectances in blue (B), green (G), red (R) and near infrared (NIR) bands from HJ-CCD (CCD sensor on Huanjing satellite) to monitor disease at a regional scale. In a suburban area in Beijing, China, an extensive field campaign for disease intensity survey was conducted at key growth stages of winter wheat in 2010. Meanwhile, corresponding time series of HJ-CCD images were acquired over the study area. In this study, a number of single-stage and multi-stage spectral features, which were sensitive to powdery mildew, were selected by using an independent t-test. With the selected spectral features, four advanced methods: mahalanobis distance, maximum likelihood classifier, partial least square regression and mixture tuned matched filtering were tested and evaluated for their performances in disease mapping. The experimental results showed that all four algorithms could generate disease maps with a generally correct distribution pattern of powdery mildew at the grain filling stage (Zadoks 72). However, by comparing these disease maps with ground survey data (validation samples), all of the four algorithms also produced a variable degree of error in estimating the disease occurrence and severity. Further, we found that the integration of MTMF and PLSR algorithms could result in a significant accuracy improvement of identifying and determining the disease intensity (overall accuracy of 72% increased to 78% and kappa coefficient of 0.49 increased to 0.59). The experimental results also demonstrated that the multi-temporal satellite images have a great potential in crop diseases mapping at a regional scale.

Compact cold stage for micro-computerized tomography imaging of chilled or frozen samples

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

Hullar, Ted; Anastasio, Cort, E-mail: canastasio@ucdavis.edu; Paige, David F.

2014-04-15

High resolution X-ray microCT (computerized tomography) can be used to image a variety of objects, including temperature-sensitive materials. In cases where the sample must be chilled or frozen to maintain sample integrity, either the microCT machine itself must be placed in a refrigerated chamber, or a relatively expensive commercial cold stage must be purchased. We describe here the design and construction of a low-cost custom cold stage suitable for use in a microCT imaging system. Our device uses a boron nitride sample holder, two-stage Peltier cooler, fan-cooled heat sink, and electronic controller to maintain sample temperatures as low as −25 °Cmore » ± 0.2 °C for the duration of a tomography acquisition. The design does not require modification to the microCT machine, and is easily installed and removed. Our custom cold stage represents a cost-effective solution for refrigerating CT samples for imaging, and is especially useful for shared equipment or machines unsuitable for cold room use.« less

Optimizing trial design in pharmacogenetics research: comparing a fixed parallel group, group sequential, and adaptive selection design on sample size requirements.

PubMed

Boessen, Ruud; van der Baan, Frederieke; Groenwold, Rolf; Egberts, Antoine; Klungel, Olaf; Grobbee, Diederick; Knol, Mirjam; Roes, Kit

2013-01-01

Two-stage clinical trial designs may be efficient in pharmacogenetics research when there is some but inconclusive evidence of effect modification by a genomic marker. Two-stage designs allow to stop early for efficacy or futility and can offer the additional opportunity to enrich the study population to a specific patient subgroup after an interim analysis. This study compared sample size requirements for fixed parallel group, group sequential, and adaptive selection designs with equal overall power and control of the family-wise type I error rate. The designs were evaluated across scenarios that defined the effect sizes in the marker positive and marker negative subgroups and the prevalence of marker positive patients in the overall study population. Effect sizes were chosen to reflect realistic planning scenarios, where at least some effect is present in the marker negative subgroup. In addition, scenarios were considered in which the assumed 'true' subgroup effects (i.e., the postulated effects) differed from those hypothesized at the planning stage. As expected, both two-stage designs generally required fewer patients than a fixed parallel group design, and the advantage increased as the difference between subgroups increased. The adaptive selection design added little further reduction in sample size, as compared with the group sequential design, when the postulated effect sizes were equal to those hypothesized at the planning stage. However, when the postulated effects deviated strongly in favor of enrichment, the comparative advantage of the adaptive selection design increased, which precisely reflects the adaptive nature of the design. Copyright © 2013 John Wiley & Sons, Ltd.

A novel design of a multi-antigenic, multistage and multi-epitope vaccine against Helicobacter pylori: An in silico approach.

PubMed

Meza, Beatriz; Ascencio, Felipe; Sierra-Beltrán, Arturo Pedro; Torres, Javier; Angulo, Carlos

2017-04-01

Helicobacter pylori have colonized the gastric mucosa of half of the population worldwide. This bacterium is classified as a definitive type I carcinogen by the World Health Organization and no effective vaccine has been found against it yet. Thus, a logical and rational vaccine design against H. pylori is necessary. Because of its tremendous complexity and elicited immune responses, the vaccine design should considered multiple antigens to enhance immune-protection, involved in the different stages of pathogenesis besides inducing a specific immune response by B- and T-cell multi-epitopes. In this study, emphasis was placed on the design of a new unique vaccine named CTB-multiHp. In silico techniques were used to design a chimeric construct consisting of cholera toxin B subunit fused to multi-epitope of urease B (residue 148-158, 188-198), cytotoxin-associated gene A (residue 584-602), neutrophil activating protein (residue 4-28), vacuolating cytotoxin gene A (residue 63-81), H. pylori adhesine A (residue77-99), heat shock protein A (residue 32-54) and gamma glutamyl transpeptidase (residue 271-293). The tertiary structure and features of the vaccine were analyzed. The chimeric protein was expressed in Escherichia coli BL21 and the serology analyses indicated that the CTB-multiHp protein produced exhibit immune-reactivity. The results showed that CTB-multiHp could be a good vaccine candidate against H. pylori. Ongoing studies will evaluate the effects of CTB-multiHp against H. pylori infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Multi-stage decoding of multi-level modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Kasami, Tadao; Costello, Daniel J., Jr.

1991-01-01

Various types of multi-stage decoding for multi-level modulation codes are investigated. It is shown that if the component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. Particularly, it is shown that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum soft-decision decoding of the code is very small, only a fraction of dB loss in signal to noise ratio at a bit error rate (BER) of 10(exp -6).

Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

NASA Technical Reports Server (NTRS)

Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.

2011-01-01

NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

Multiple Imputation in Two-Stage Cluster Samples Using The Weighted Finite Population Bayesian Bootstrap.

PubMed

Zhou, Hanzhi; Elliott, Michael R; Raghunathan, Trivellore E

2016-06-01

Multistage sampling is often employed in survey samples for cost and convenience. However, accounting for clustering features when generating datasets for multiple imputation is a nontrivial task, particularly when, as is often the case, cluster sampling is accompanied by unequal probabilities of selection, necessitating case weights. Thus, multiple imputation often ignores complex sample designs and assumes simple random sampling when generating imputations, even though failing to account for complex sample design features is known to yield biased estimates and confidence intervals that have incorrect nominal coverage. In this article, we extend a recently developed, weighted, finite-population Bayesian bootstrap procedure to generate synthetic populations conditional on complex sample design data that can be treated as simple random samples at the imputation stage, obviating the need to directly model design features for imputation. We develop two forms of this method: one where the probabilities of selection are known at the first and second stages of the design, and the other, more common in public use files, where only the final weight based on the product of the two probabilities is known. We show that this method has advantages in terms of bias, mean square error, and coverage properties over methods where sample designs are ignored, with little loss in efficiency, even when compared with correct fully parametric models. An application is made using the National Automotive Sampling System Crashworthiness Data System, a multistage, unequal probability sample of U.S. passenger vehicle crashes, which suffers from a substantial amount of missing data in "Delta-V," a key crash severity measure.

Multiple Imputation in Two-Stage Cluster Samples Using The Weighted Finite Population Bayesian Bootstrap

PubMed Central

Zhou, Hanzhi; Elliott, Michael R.; Raghunathan, Trivellore E.

2017-01-01

Multistage sampling is often employed in survey samples for cost and convenience. However, accounting for clustering features when generating datasets for multiple imputation is a nontrivial task, particularly when, as is often the case, cluster sampling is accompanied by unequal probabilities of selection, necessitating case weights. Thus, multiple imputation often ignores complex sample designs and assumes simple random sampling when generating imputations, even though failing to account for complex sample design features is known to yield biased estimates and confidence intervals that have incorrect nominal coverage. In this article, we extend a recently developed, weighted, finite-population Bayesian bootstrap procedure to generate synthetic populations conditional on complex sample design data that can be treated as simple random samples at the imputation stage, obviating the need to directly model design features for imputation. We develop two forms of this method: one where the probabilities of selection are known at the first and second stages of the design, and the other, more common in public use files, where only the final weight based on the product of the two probabilities is known. We show that this method has advantages in terms of bias, mean square error, and coverage properties over methods where sample designs are ignored, with little loss in efficiency, even when compared with correct fully parametric models. An application is made using the National Automotive Sampling System Crashworthiness Data System, a multistage, unequal probability sample of U.S. passenger vehicle crashes, which suffers from a substantial amount of missing data in “Delta-V,” a key crash severity measure. PMID:29226161

Use and Effectiveness of Neoadjuvant Chemotherapy for Treatment of Ovarian Cancer

PubMed Central

Cronin, Angel M.; Sun, Charlotte C.; Bixel, Kristin; Bookman, Michael A.; Cristea, Mihaela C.; Griggs, Jennifer J.; Levenback, Charles F.; Burger, Robert A.; Mantia-Smaldone, Gina; Matulonis, Ursula A.; Niland, Joyce C.; O’Malley, David M.; Wright, Alexi A.

2016-01-01

Purpose In 2010, a randomized clinical trial demonstrated noninferior survival for patients with advanced ovarian cancer who were treated with neoadjuvant chemotherapy (NACT) compared with primary cytoreductive surgery (PCS). We examined the use and effectiveness of NACT in clinical practice. Patients and Methods A multi-institutional observational study of 1,538 women with stages IIIC to IV ovarian cancer who were treated at six National Cancer Institute–designated cancer centers. We examined NACT use in patients who were diagnosed between 2003 and 2012 (N = 1,538) and compared overall survival (OS), morbidity, and postoperative residual disease in a propensity-score matched sample of patients (N = 594). Results NACT use increased from 16% during 2003 to 2010 to 34% during 2011 to 2012 in stage IIIC disease (Ptrend < .001), and from 41% to 62% in stage IV disease (Ptrend < .001). Adoption of NACT varied by institution, from 8% to 30% for stage IIIC disease (P < .001) and from 27% to 61% (P = .007) for stage IV disease during this time period. In the matched sample, NACT was associated with shorter OS in stage IIIC disease (median OS: 33 v 43 months; hazard ratio [HR], 1.40; 95% CI, 1.11 to 1.77) compared with PCS, but not stage IV disease (median OS: 31 v 36 months; HR, 1.16; 95% CI, 0.89 to 1.52). Patients with stages IIIC and IV disease who received NACT were less likely to have ≥ 1 cm postoperative residual disease, an intensive care unit admission, or a rehospitalization (all P ≤ .04) compared with those who received PCS treatment. However, among women with stage IIIC disease who achieved microscopic or ≤ 1 cm postoperative residual disease, NACT was associated with decreased OS (HR, 1.49; 95% CI, 1.01 to 2.18; P = .04). Conclusion Use of NACT increased significantly between 2003 and 2012. In this observational study, PCS was associated with increased survival in stage IIIC, but not stage IV disease. Future studies should prospectively consider the efficacy of NACT by extent of residual disease in unselected patients. PMID:27601552

Low-carbon building assessment and multi-scale input-output analysis

NASA Astrophysics Data System (ADS)

Chen, G. Q.; Chen, H.; Chen, Z. M.; Zhang, Bo; Shao, L.; Guo, S.; Zhou, S. Y.; Jiang, M. M.

2011-01-01

Presented as a low-carbon building evaluation framework in this paper are detailed carbon emission account procedures for the life cycle of buildings in terms of nine stages as building construction, fitment, outdoor facility construction, transportation, operation, waste treatment, property management, demolition, and disposal for buildings, supported by integrated carbon intensity databases based on multi-scale input-output analysis, essential for low-carbon planning, procurement and supply chain design, and logistics management.

Prednisolone and acupuncture in Bell's palsy: study protocol for a randomized, controlled trial

PubMed Central

2011-01-01

Background There are a variety of treatment options for Bell's palsy. Evidence from randomized controlled trials indicates corticosteroids can be used as a proven therapy for Bell's palsy. Acupuncture is one of the most commonly used methods to treat Bell's palsy in China. Recent studies suggest that staging treatment is more suitable for Bell's palsy, according to different path-stages of this disease. The aim of this study is to compare the effects of prednisolone and staging acupuncture in the recovery of the affected facial nerve, and to verify whether prednisolone in combination with staging acupuncture is more effective than prednisolone alone for Bell's palsy in a large number of patients. Methods/Design In this article, we report the design and protocol of a large sample multi-center randomized controlled trial to treat Bell's palsy with prednisolone and/or acupuncture. In total, 1200 patients aged 18 to 75 years within 72 h of onset of acute, unilateral, peripheral facial palsy will be assessed. There are six treatment groups, with four treated according to different path-stages and two not. These patients are randomly assigned to be in one of the following six treatment groups, i.e. 1) placebo prednisolone group, 2) prednisolone group, 3) placebo prednisolone plus acute stage acupuncture group, 4) prednisolone plus acute stage acupuncture group, 5) placebo prednisolone plus resting stage acupuncture group, 6) prednisolone plus resting stage acupuncture group. The primary outcome is the time to complete recovery of facial function, assessed by Sunnybrook system and House-Brackmann scale. The secondary outcomes include the incidence of ipsilateral pain in the early stage of palsy (and the duration of this pain), the proportion of patients with severe pain, the occurrence of synkinesis, facial spasm or contracture, and the severity of residual facial symptoms during the study period. Discussion The result of this trial will assess the efficacy of using prednisolone and staging acupuncture to treat Bell's palsy, and to determine a best combination therapy with prednisolone and acupuncture for treating Bell's palsy. Trial Registration ClinicalTrials.gov: NCT01201642 PMID:21693007

A Profile of Puerto Rican Health in the United States: Data from the Hispanic Health and Nutrition Examination Survey 1982-84.

ERIC Educational Resources Information Center

Munoz, Eric; And Others

The health conditions and health status of Hispanic Americans will assume increased importance as their population increases. The goal of this book of charts is to present data from the Hispanic Health and Nutrition Examination Survey (HHANES) on Puerto Ricans. The Puerto Rican HHANES sampling procedure is a multi-stage probability sample of…

A Gender Based Study on Job Satisfaction among Higher Secondary School Heads in Khyber Pakhtunkhwa, (Pakistan)

ERIC Educational Resources Information Center

Mumtaz, Safina; Suleman, Qaiser; Ahmad, Zubair

2016-01-01

The purpose of the study was to analyze and compare the job satisfaction with twenty dimensions of male and female higher secondary school heads in Khyber Pakhtunkhwa. A total of 108 higher secondary school heads were selected from eleven districts as sample through multi-stage sampling technique in which 66 were male and 42 were female. The study…

Power calculation for comparing diagnostic accuracies in a multi-reader, multi-test design.

PubMed

Kim, Eunhee; Zhang, Zheng; Wang, Youdan; Zeng, Donglin

2014-12-01

Receiver operating characteristic (ROC) analysis is widely used to evaluate the performance of diagnostic tests with continuous or ordinal responses. A popular study design for assessing the accuracy of diagnostic tests involves multiple readers interpreting multiple diagnostic test results, called the multi-reader, multi-test design. Although several different approaches to analyzing data from this design exist, few methods have discussed the sample size and power issues. In this article, we develop a power formula to compare the correlated areas under the ROC curves (AUC) in a multi-reader, multi-test design. We present a nonparametric approach to estimate and compare the correlated AUCs by extending DeLong et al.'s (1988, Biometrics 44, 837-845) approach. A power formula is derived based on the asymptotic distribution of the nonparametric AUCs. Simulation studies are conducted to demonstrate the performance of the proposed power formula and an example is provided to illustrate the proposed procedure. © 2014, The International Biometric Society.

Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms.

PubMed

Guo, Chaohua; Wei, Mingzhen; Liu, Hong

2018-01-01

Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no systematical work has been conducted considering all reasonable transport mechanisms. And there are very few works on sensitivity studies of uncertain parameters using real parameter ranges. Hence, a detailed and systematic study of reservoir simulation with MsFHW is still necessary. In this paper, a dual porosity model was constructed to estimate the effect of parameters on shale gas production with MsFHW. The simulation model was verified with the available field data from the Barnett Shale. The following mechanisms have been considered in this model: viscous flow, slip flow, Knudsen diffusion, and gas desorption. Langmuir isotherm was used to simulate the gas desorption process. Sensitivity analysis on SGRs' production performance with MsFHW has been conducted. Parameters influencing shale gas production were classified into two categories: reservoir parameters including matrix permeability, matrix porosity; and hydraulic fracture parameters including hydraulic fracture spacing, and fracture half-length. Typical ranges of matrix parameters have been reviewed. Sensitivity analysis have been conducted to analyze the effect of the above factors on the production performance of SGRs. Through comparison, it can be found that hydraulic fracture parameters are more sensitive compared with reservoir parameters. And reservoirs parameters mainly affect the later production period. However, the hydraulic fracture parameters have a significant effect on gas production from the early period. The results of this study can be used to improve the efficiency of history matching process. Also, it can contribute to the design and optimization of hydraulic fracture treatment design in unconventional SGRs.

Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms

PubMed Central

Wei, Mingzhen; Liu, Hong

2018-01-01

Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no systematical work has been conducted considering all reasonable transport mechanisms. And there are very few works on sensitivity studies of uncertain parameters using real parameter ranges. Hence, a detailed and systematic study of reservoir simulation with MsFHW is still necessary. In this paper, a dual porosity model was constructed to estimate the effect of parameters on shale gas production with MsFHW. The simulation model was verified with the available field data from the Barnett Shale. The following mechanisms have been considered in this model: viscous flow, slip flow, Knudsen diffusion, and gas desorption. Langmuir isotherm was used to simulate the gas desorption process. Sensitivity analysis on SGRs’ production performance with MsFHW has been conducted. Parameters influencing shale gas production were classified into two categories: reservoir parameters including matrix permeability, matrix porosity; and hydraulic fracture parameters including hydraulic fracture spacing, and fracture half-length. Typical ranges of matrix parameters have been reviewed. Sensitivity analysis have been conducted to analyze the effect of the above factors on the production performance of SGRs. Through comparison, it can be found that hydraulic fracture parameters are more sensitive compared with reservoir parameters. And reservoirs parameters mainly affect the later production period. However, the hydraulic fracture parameters have a significant effect on gas production from the early period. The results of this study can be used to improve the efficiency of history matching process. Also, it can contribute to the design and optimization of hydraulic fracture treatment design in unconventional SGRs. PMID:29320489

Demonstration of the Attributes of Multi-increment Sampling and Proper Sample Processing Protocols for the Characterization of Metals on DoD Facilities

DTIC Science & Technology

2013-06-01

lenses of unconsolidated sand and rounded river gravel overlain by as much as 5 m of silt. Gravel consists mostly of quartz and metamorphic rock with...iii LIST OF FIGURES Page Figure 1. Example of multi-increment sampling using a systematic-random sampling design for collecting two separate...The small arms firing Range 16 Record berms at Fort Wainwright. .................... 25 Figure 9. Location of berms sampled using ISM and grab

Separation of Platinum from Palladium and Iridium in Iron Meteorites and Accurate High-Precision Determination of Platinum Isotopes by Multi-Collector ICP-MS.

PubMed

Hunt, Alison C; Ek, Mattias; Schönbächler, Maria

2017-12-01

This study presents a new measurement procedure for the isolation of Pt from iron meteorite samples. The method also allows for the separation of Pd from the same sample aliquot. The separation entails a two-stage anion-exchange procedure. In the first stage, Pt and Pd are separated from each other and from major matrix constituents including Fe and Ni. In the second stage, Ir is reduced with ascorbic acid and eluted from the column before Pt collection. Platinum yields for the total procedure were typically 50-70%. After purification, high-precision Pt isotope determinations were performed by multi-collector ICP-MS. The precision of the new method was assessed using the IIAB iron meteorite North Chile. Replicate analyses of multiple digestions of this material yielded an intermediate precision for the measurement results of 0.73 for ε 192 Pt, 0.15 for ε 194 Pt and 0.09 for ε 196 Pt (2 standard deviations). The NIST SRM 3140 Pt solution reference material was passed through the measurement procedure and yielded an isotopic composition that is identical to the unprocessed Pt reference material. This indicates that the new technique is unbiased within the limit of the estimated uncertainties. Data for three iron meteorites support that Pt isotope variations in these samples are due to exposure to galactic cosmic rays in space.

A method for automatic grain segmentation of multi-angle cross-polarized microscopic images of sandstone

NASA Astrophysics Data System (ADS)

Jiang, Feng; Gu, Qing; Hao, Huizhen; Li, Na; Wang, Bingqian; Hu, Xiumian

2018-06-01

Automatic grain segmentation of sandstone is to partition mineral grains into separate regions in the thin section, which is the first step for computer aided mineral identification and sandstone classification. The sandstone microscopic images contain a large number of mixed mineral grains where differences among adjacent grains, i.e., quartz, feldspar and lithic grains, are usually ambiguous, which make grain segmentation difficult. In this paper, we take advantage of multi-angle cross-polarized microscopic images and propose a method for grain segmentation with high accuracy. The method consists of two stages, in the first stage, we enhance the SLIC (Simple Linear Iterative Clustering) algorithm, named MSLIC, to make use of multi-angle images and segment the images as boundary adherent superpixels. In the second stage, we propose the region merging technique which combines the coarse merging and fine merging algorithms. The coarse merging merges the adjacent superpixels with less evident boundaries, and the fine merging merges the ambiguous superpixels using the spatial enhanced fuzzy clustering. Experiments are designed on 9 sets of multi-angle cross-polarized images taken from the three major types of sandstones. The results demonstrate both the effectiveness and potential of the proposed method, comparing to the available segmentation methods.

Large-scale multi-stage constructed wetlands for secondary effluents treatment in northern China: Carbon dynamics.

PubMed

Wu, Haiming; Fan, Jinlin; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan

2018-02-01

Multi-stage constructed wetlands (CWs) have been proved to be a cost-effective alternative in the treatment of various wastewaters for improving the treatment performance as compared with the conventional single-stage CWs. However, few long-term full-scale multi-stage CWs have been performed and evaluated for polishing effluents from domestic wastewater treatment plants (WWTP). This study investigated the seasonal and spatial dynamics of carbon and the effects of the key factors (input loading and temperature) in the large-scale seven-stage Wu River CW polishing domestic WWTP effluents in northern China. The results indicated a significant improvement in water quality. Significant seasonal and spatial variations of organics removal were observed in the Wu River CW with a higher COD removal efficiency of 64-66% in summer and fall. Obvious seasonal and spatial variations of CH 4 and CO 2 emissions were also found with the average CH 4 and CO 2 emission rates of 3.78-35.54 mg m -2 d -1 and 610.78-8992.71 mg m -2 d -1 , respectively, while the higher CH 4 and CO 2 emission flux was obtained in spring and summer. Seasonal air temperatures and inflow COD loading rates significantly affected organics removal and CH 4 emission, but they appeared to have a weak influence on CO 2 emission. Overall, this study suggested that large-scale Wu River CW might be a potential source of GHG, but considering the sustainability of the multi-stage CW, the inflow COD loading rate of 1.8-2.0 g m -2 d -1 and temperature of 15-20 °C may be the suitable condition for achieving the higher organics removal efficiency and lower greenhouse gases (GHG) emission in polishing the domestic WWTP effluent. The obtained knowledge of the carbon dynamics in large-scale Wu River CW will be helpful for understanding the carbon cycles, but also can provide useful field experience for the design, operation and management of multi-stage CW treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

A false sense of security? Can tiered approach be trusted to accurately classify immunogenicity samples?

PubMed

Jaki, Thomas; Allacher, Peter; Horling, Frank

2016-09-05

Detecting and characterizing of anti-drug antibodies (ADA) against a protein therapeutic are crucially important to monitor the unwanted immune response. Usually a multi-tiered approach that initially rapidly screens for positive samples that are subsequently confirmed in a separate assay is employed for testing of patient samples for ADA activity. In this manuscript we evaluate the ability of different methods used to classify subject with screening and competition based confirmatory assays. We find that for the overall performance of the multi-stage process the method used for confirmation is most important where a t-test is best when differences are moderate to large. Moreover we find that, when differences between positive and negative samples are not sufficiently large, using a competition based confirmation step does yield poor classification of positive samples. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Automatic extraction and processing of small RNAs on a multi-well/multi-channel (M&M) chip.

PubMed

Zhong, Runtao; Flack, Kenneth; Zhong, Wenwan

2012-12-07

The study of the regulatory roles in small RNAs can be accelerated by techniques that permit simple, low-cost, and rapid extraction of small RNAs from a small number of cells. In order to ensure highly specific and sensitive detection, the extracted RNAs should be free of the background nucleic acids and present stably in a small volume. To meet these criteria, we designed a multi-well/multi-channel (M&M) chip to carry out automatic and selective isolation of small RNAs via solid-phase extraction (SPE), followed by reverse-transcription (RT) to convert them to the more stable cDNAs in a final volume of 2 μL. Droplets containing buffers for RNA binding, washing, and elution were trapped in microwells, which were connected by one channel, and suspended in mineral oil. The silica magnetic particles (SMPs) for SPE were moved along the channel from well to well, i.e. in between droplets, by a fixed magnet and a translation stage, allowing the nucleic acid fragments to bind to the SMPs, be washed, and then be eluted for RT reaction within 15 minutes. RNAs shorter than 63 nt were selectively enriched from cell lysates, with recovery comparable to that of a commercial kit. Physical separation of the droplets on our M&M chip allowed the usage of multiple channels for parallel processing of multiple samples. It also permitted smooth integration with on-chip RT-PCR, which simultaneously detected the target microRNA, mir-191, expressed in fewer than 10 cancer cells. Our results have demonstrated that the M&M chip device is a valuable and cost-saving platform for studying small RNA expression patterns in a limited number of cells with reasonable sample throughput.

Design of a multi-spectral imager built using the compressive sensing single-pixel camera architecture

NASA Astrophysics Data System (ADS)

McMackin, Lenore; Herman, Matthew A.; Weston, Tyler

2016-02-01

We present the design of a multi-spectral imager built using the architecture of the single-pixel camera. The architecture is enabled by the novel sampling theory of compressive sensing implemented optically using the Texas Instruments DLP™ micro-mirror array. The array not only implements spatial modulation necessary for compressive imaging but also provides unique diffractive spectral features that result in a multi-spectral, high-spatial resolution imager design. The new camera design provides multi-spectral imagery in a wavelength range that extends from the visible to the shortwave infrared without reduction in spatial resolution. In addition to the compressive imaging spectrometer design, we present a diffractive model of the architecture that allows us to predict a variety of detailed functional spatial and spectral design features. We present modeling results, architectural design and experimental results that prove the concept.

Space Launch System Development Status

NASA Technical Reports Server (NTRS)

Lyles, Garry

2014-01-01

Development of NASA's Space Launch System (SLS) heavy lift rocket is shifting from the formulation phase into the implementation phase in 2014, a little more than three years after formal program approval. Current development is focused on delivering a vehicle capable of launching 70 metric tons (t) into low Earth orbit. This "Block 1" configuration will launch the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back in December 2017, followed by its first crewed flight in 2021. SLS can evolve to a130-t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. Benefits associated with its unprecedented mass and volume include reduced trip times and simplified payload design. Every SLS element achieved significant, tangible progress over the past year. Among the Program's many accomplishments are: manufacture of Core Stage test panels; testing of Solid Rocket Booster development hardware including thrust vector controls and avionics; planning for testing the RS-25 Core Stage engine; and more than 4,000 wind tunnel runs to refine vehicle configuration, trajectory, and guidance. The Program shipped its first flight hardware - the Multi-Purpose Crew Vehicle Stage Adapter (MSA) - to the United Launch Alliance for integration with the Delta IV heavy rocket that will launch an Orion test article in 2014 from NASA's Kennedy Space Center. Objectives of this Earth-orbit flight include validating the performance of Orion's heat shield and the MSA design, which will be manufactured again for SLS missions to deep space. The Program successfully completed Preliminary Design Review in 2013 and Key Decision Point C in early 2014. NASA has authorized the Program to move forward to Critical Design Review, scheduled for 2015 and a December 2017 first launch. The Program's success to date is due to prudent use of proven technology, infrastructure, and workforce from the Saturn and Space Shuttle programs, a streamlined management approach, and judicious use of new technologies. The result is a safe, affordable, sustainable, and evolutionary path to development of an unprecedented capability for future missions across the solar system. In an environment of economic challenges, the nationwide SLS team continues to meet ambitious budget and schedule targets. This paper will discuss SLS program and technical accomplishments over the past year and provide a look at the milestones and challenges ahead.

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

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

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I 3TEM) offers the unique ability to observe microstructural changes duemore » to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. As a result, this work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO 2.« less

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

DOE PAGES

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana; ...

2017-09-29

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I 3TEM) offers the unique ability to observe microstructural changes duemore » to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. As a result, this work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO 2.« less

A Multi-Technique Forensic Experiment for a Nonscience-Major Chemistry Course

ERIC Educational Resources Information Center

Szalay, Paul S.; Zook-Gerdau, Lois Anne; Schurter, Eric J.

2011-01-01

This multi-technique experiment with a forensic theme was developed for a nonscience-major chemistry course. The students are provided with solid samples and informed that the samples are either cocaine or a combination of drugs designed to mimic the stimulant and anesthetic qualities of cocaine such as caffeine and lidocaine. The students carry…

Multi-stage decoding for multi-level block modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Kasami, Tadao

1991-01-01

Various types of multistage decoding for multilevel block modulation codes, in which the decoding of a component code at each stage can be either soft decision or hard decision, maximum likelihood or bounded distance are discussed. Error performance for codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. It was found that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. It was found that the difference in performance between the suboptimum multi-stage soft decision maximum likelihood decoding of a modulation code and the single stage optimum decoding of the overall code is very small, only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

Recent advances in recombinant protein-based malaria vaccines.

PubMed

Draper, Simon J; Angov, Evelina; Horii, Toshihiro; Miller, Louis H; Srinivasan, Prakash; Theisen, Michael; Biswas, Sumi

2015-12-22

Plasmodium parasites are the causative agent of human malaria, and the development of a highly effective vaccine against infection, disease and transmission remains a key priority. It is widely established that multiple stages of the parasite's complex lifecycle within the human host and mosquito vector are susceptible to vaccine-induced antibodies. The mainstay approach to antibody induction by subunit vaccination has been the delivery of protein antigen formulated in adjuvant. Extensive efforts have been made in this endeavor with respect to malaria vaccine development, especially with regard to target antigen discovery, protein expression platforms, adjuvant testing, and development of soluble and virus-like particle (VLP) delivery platforms. The breadth of approaches to protein-based vaccines is continuing to expand as innovative new concepts in next-generation subunit design are explored, with the prospects for the development of a highly effective multi-component/multi-stage/multi-antigen formulation seeming ever more likely. This review will focus on recent progress in protein vaccine design, development and/or clinical testing for a number of leading malaria antigens from the sporozoite-, merozoite- and sexual-stages of the parasite's lifecycle-including PfCelTOS, PfMSP1, PfAMA1, PfRH5, PfSERA5, PfGLURP, PfMSP3, Pfs48/45 and Pfs25. Future prospects and challenges for the development, production, human delivery and assessment of protein-based malaria vaccines are discussed. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The impact of study design and diagnostic approach in a large multi-centre ADHD study: Part 2: Dimensional measures of psychopathology and intelligence.

PubMed

Müller, Ueli C; Asherson, Philip; Banaschewski, Tobias; Buitelaar, Jan K; Ebstein, Richard P; Eisenberg, Jaques; Gill, Michael; Manor, Iris; Miranda, Ana; Oades, Robert D; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph A; Sonuga-Barke, Edmund Js; Thompson, Margaret; Faraone, Stephen V; Steinhausen, Hans-Christoph

2011-04-07

The International Multi-centre ADHD Genetics (IMAGE) project with 11 participating centres from 7 European countries and Israel has collected a large behavioural and genetic database for present and future research. Behavioural data were collected from 1068 probands with ADHD and 1446 unselected siblings. The aim was to describe and analyse questionnaire data and IQ measures from all probands and siblings. In particular, to investigate the influence of age, gender, family status (proband vs. sibling), informant, and centres on sample homogeneity in psychopathological measures. Conners' Questionnaires, Strengths and Difficulties Questionnaires, and Wechsler Intelligence Scores were used to describe the phenotype of the sample. Data were analysed by use of robust statistical multi-way procedures. Besides main effects of age, gender, informant, and centre, there were considerable interaction effects on questionnaire data. The larger differences between probands and siblings at home than at school may reflect contrast effects in the parents. Furthermore, there were marked gender by status effects on the ADHD symptom ratings with girls scoring one standard deviation higher than boys in the proband sample but lower than boys in the siblings sample. The multi-centre design is another important source of heterogeneity, particularly in the interaction with the family status. To a large extent the centres differed from each other with regard to differences between proband and sibling scores. When ADHD probands are diagnosed by use of fixed symptom counts, the severity of the disorder in the proband sample may markedly differ between boys and girls and across age, particularly in samples with a large age range. A multi-centre design carries the risk of considerable phenotypic differences between centres and, consequently, of additional heterogeneity of the sample even if standardized diagnostic procedures are used. These possible sources of variance should be counteracted in genetic analyses either by using age and gender adjusted diagnostic procedures and regional normative data or by adjusting for design artefacts by use of covariate statistics, by eliminating outliers, or by other methods suitable for reducing heterogeneity.

Light scattering by ultrasonically-controlled small particles: system design, calibration, and measurement results

NASA Astrophysics Data System (ADS)

Kassamakov, Ivan; Maconi, Göran; Penttilä, Antti; Helander, Petteri; Gritsevich, Maria; Puranen, Tuomas; Salmi, Ari; Hæggström, Edward; Muinonen, Karri

2018-02-01

We present the design of a novel scatterometer for precise measurement of the angular Mueller matrix profile of a mm- to µm-sized sample held in place by sound. The scatterometer comprises a tunable multimode Argon-krypton laser (with possibility to set 1 of the 12 wavelengths in visible range), linear polarizers, a reference photomultiplier tube (PMT) for monitoring the beam intensity, and a micro-PMT module mounted radially towards the sample at an adjustable radius. The measurement angle is controlled by a motor-driven rotation stage with an accuracy of 15'. The system is fully automated using LabVIEW, including the FPGA-based data acquisition and the instrument's user interface. The calibration protocol ensures accurate measurements by using a control sphere sample (diameter 3 mm, refractive index of 1.5) fixed first on a static holder followed by accurate multi-wavelength measurements of the same sample levitated ultrasonically. To demonstrate performance of the scatterometer, we conducted detailed measurements of light scattered by a particle derived from the Chelyabinsk meteorite, as well as planetary analogue materials. The measurements are the first of this kind, since they are obtained using controlled spectral angular scattering including linear polarization effects, for arbitrary shaped objects. Thus, our novel approach permits a non-destructive, disturbance-free measurement with control of the orientation and location of the scattering object.

Novel product ions of 2-aminoanilide and benzimidazole Ag(I) complexes using electrospray ionization with multi-stage tandem mass spectrometry.

PubMed

Johnson, Byron S; Burinsky, David J; Burova, Svetlana A; Davis, Roman; Fitzgerald, Russ N; Matsuoka, Richard T

2012-05-15

The 2-aminoaniline scaffold is of significant value to the pharmaceutical industry and is embedded in a number of pharmacophores including 2-aminoanilides and benzimidazoles. A novel application of coordination ion spray mass spectrometry (CIS-MS) for interrogating the silver ion (Ag(+)) complexes of a homologous series of these compounds using multi-stage tandem mass spectrometry is described. Unlike the ubiquitous alkali metal ion complexes, Ag(+) complexes of 2-aminoanilides and benzimidazoles were found to yield [M - H](+) ions in significant abundance via gas-phase elimination of the metal hydride (AgH) resulting in unique product ion cascades. Sample introduction was by liquid chromatography with mass spectrometry analysis performed on a hybrid linear ion trap/orbitrap instrument capable of high-resolution measurements. Rigorous structural characterization by multi-stage tandem mass spectrometry using [M +  H](+), [M - H](-) and [M - H](+) precursor ions derived from ESI and CIS experiments was performed for the homologous series of 2-aminoanilide and benzimidazole compounds. A full tabular comparison of structural information resulting from these product ion cascades was produced. Multi-stage tandem mass spectrometry of [M - H](+) ions resulting from Ag(+) complexes of 2-aminoanilides and benzimidazoles in CIS-MS experiments produced unique product ion cascades that exhibited complementary structural information to that obtained from tandem mass spectrometry of [M  +  H](+) and [M - H](-) ions by electrospray ionization (ESI). These observations may be broadly applicable to other compounds that are observed to form Ag(+) complexes and eliminate AgH. Copyright © 2012 John Wiley & Sons, Ltd.

Hyper-X Stage Separation Wind Tunnel Test Program

NASA Technical Reports Server (NTRS)

Woods, W. C.; Holland, S. D.; DiFulvio, M.

2000-01-01

NASA's Hyper-X research program was developed primarily to flight demonstrate a supersonic combustion ramjet engine, fully integrated with a forebody designed to tailor inlet flow conditions and a free expansion nozzle/afterbody to produce positive thrust at design flight conditions. With a point-designed propulsion system, the vehicle must depend upon some other means for boost to its design flight condition. Clean separation from this initial propulsion system stage within less than a second is critical to the success of the flight. This paper discusses the early planning activity, background, and chronology that developed the series of wind tunnel tests to support multi degree of freedom simulation of the separation process. Representative results from each series of tests are presented and issues and concerns during the process and current status will be highlighted.

Hyper-X Stage Separation Wind-Tunnel Test Program

NASA Technical Reports Server (NTRS)

Woods, William C.; Holland, Scott D.; DiFulvio, Michael

2001-01-01

NASA's Hyper-X research program was developed primarily to flight demonstrate a supersonic combustion ramjet engine, fully integrated with a forebody designed to tailor inlet flow conditions and a free expansion nozzle/afterbody to produce positive thrust at design flight conditions. With a point-designed propulsion system the vehicle must depend on some other means for boost to its design flight condition. Clean separation from this initial propulsion system stage within less than a second is critical to the success of the flight. This paper discusses the early planning activity, background, and chronology that developed the series of wind-tunnel tests to support multi-degree-of-freedom simulation of the separation process. Representative results from each series of tests are presented, and issues and concerns during the process and current status are highlighted.

OAST Space Theme Workshop. Volume 3: Working group summary. 9: Aerothermodynamics (M-3). A: Statement. B: Technology needs (form 1). C. Priority assessment (form 2). D. Additional assessments

NASA Technical Reports Server (NTRS)

1976-01-01

Twelve aerothermodynamic space technology needs were identified to reduce the design uncertainties in aerodynamic heating and forces experienced by heavy lift launch vehicles, orbit transfer vehicles, and advanced single stage to orbit vehicles for the space transportation system, and for probes, planetary surface landers, and sample return vehicles for solar system exploration vehicles. Research and technology needs identified include: (1) increasing the fluid dynamics capability by at least two orders of magnitude by developing an advanced computer processor for the solution of fluid dynamic problems with improved software; (2) predicting multi-engine base flow fields for launch vehicles; and (3) developing methods to conserve energy in aerothermodynamic ground test facilities.

A priori evaluation of two-stage cluster sampling for accuracy assessment of large-area land-cover maps

USGS Publications Warehouse

Wickham, J.D.; Stehman, S.V.; Smith, J.H.; Wade, T.G.; Yang, L.

2004-01-01

Two-stage cluster sampling reduces the cost of collecting accuracy assessment reference data by constraining sample elements to fall within a limited number of geographic domains (clusters). However, because classification error is typically positively spatially correlated, within-cluster correlation may reduce the precision of the accuracy estimates. The detailed population information to quantify a priori the effect of within-cluster correlation on precision is typically unavailable. Consequently, a convenient, practical approach to evaluate the likely performance of a two-stage cluster sample is needed. We describe such an a priori evaluation protocol focusing on the spatial distribution of the sample by land-cover class across different cluster sizes and costs of different sampling options, including options not imposing clustering. This protocol also assesses the two-stage design's adequacy for estimating the precision of accuracy estimates for rare land-cover classes. We illustrate the approach using two large-area, regional accuracy assessments from the National Land-Cover Data (NLCD), and describe how the a priorievaluation was used as a decision-making tool when implementing the NLCD design.

Developing Evidence for Public Health Policy and Practice: The Implementation of a Knowledge Translation Approach in a Staged, Multi-Methods Study in England, 2007-09

ERIC Educational Resources Information Center

South, Jane; Cattan, Mima

2014-01-01

Effective knowledge translation processes are critical for the development of evidence-based public health policy and practice. This paper reports on the design and implementation of an innovative approach to knowledge translation within a mixed methods study on lay involvement in public health programme delivery. The study design drew on…

Multistage aerospace craft. [perspective drawings of conceptual design

NASA Technical Reports Server (NTRS)

Kelly, D. L. (Inventor)

1973-01-01

A conceptual design of a multi-stage aerospace craft is presented. Two perspective views of the vehicle are developed to show the two component configuration with delta wing, four vertical tail surfaces, tricycle landing gear, and two rocket exhaust nozzles at the rear of the fuselage. Engines for propulsion in the atmosphere are mounted on the fuselage in front of the wing root attachment.

Design for life-cycle profit with simultaneous consideration of initial manufacturing and end-of-life remanufacturing

NASA Astrophysics Data System (ADS)

Kwak, Minjung; Kim, Harrison

2015-01-01

Remanufacturing is emerging as a promising solution for achieving green, profitable businesses. This article considers a manufacturer that produces new products and also remanufactured versions of the new products that become available at the end of their life cycle. For such a manufacturer, design decisions at the initial design stage determine both the current profit from manufacturing and future profit from remanufacturing. To maximize the total profit, design decisions must carefully consider both ends of product life cycle, i.e. manufacturing and end-of-life stages. This article proposes a decision-support model for the life-cycle design using mixed-integer nonlinear programming. With an aim to maximize the total life-cycle profit, the proposed model searches for an (at least locally) optimal product design (i.e. design specifications and the selling price) for the new and remanufactured products. It optimizes both the initial design and design upgrades at the end-of-life stage and also provides corresponding production strategies, including production quantities and take-back rate. The model is extended to a multi-objective model that maximizes both economic profit and environmental-impact saving. To illustrate, the developed model is demonstrated with an example of a desktop computer.

Statistical inference for extended or shortened phase II studies based on Simon's two-stage designs.

PubMed

Zhao, Junjun; Yu, Menggang; Feng, Xi-Ping

2015-06-07

Simon's two-stage designs are popular choices for conducting phase II clinical trials, especially in the oncology trials to reduce the number of patients placed on ineffective experimental therapies. Recently Koyama and Chen (2008) discussed how to conduct proper inference for such studies because they found that inference procedures used with Simon's designs almost always ignore the actual sampling plan used. In particular, they proposed an inference method for studies when the actual second stage sample sizes differ from planned ones. We consider an alternative inference method based on likelihood ratio. In particular, we order permissible sample paths under Simon's two-stage designs using their corresponding conditional likelihood. In this way, we can calculate p-values using the common definition: the probability of obtaining a test statistic value at least as extreme as that observed under the null hypothesis. In addition to providing inference for a couple of scenarios where Koyama and Chen's method can be difficult to apply, the resulting estimate based on our method appears to have certain advantage in terms of inference properties in many numerical simulations. It generally led to smaller biases and narrower confidence intervals while maintaining similar coverages. We also illustrated the two methods in a real data setting. Inference procedures used with Simon's designs almost always ignore the actual sampling plan. Reported P-values, point estimates and confidence intervals for the response rate are not usually adjusted for the design's adaptiveness. Proper statistical inference procedures should be used.

WV R-EMAP STUDY: MULTIPLE-OBJECTIVE SAMPLING DESIGN FRAMEWORK

EPA Science Inventory

A multi-objective sampling design has been implemented through Regional Monitoring and Assessment Program (R-EMAP) support of a cooperative agreement with the state of West Virginia. Goals of the project include: 1) development and testing of a temperature-adjusted fish IBI for t...

Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia

PubMed Central

2013-01-01

Background As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials. Methods We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon’s two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach. Results Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm. Conclusions SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics. PMID:23819695

Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia.

PubMed

Yap, Christina; Pettitt, Andrew; Billingham, Lucinda

2013-07-03

As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials. We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon's two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach. Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm. SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics.

Two-stage sequential sampling: A neighborhood-free adaptive sampling procedure

USGS Publications Warehouse

Salehi, M.; Smith, D.R.

2005-01-01

Designing an efficient sampling scheme for a rare and clustered population is a challenging area of research. Adaptive cluster sampling, which has been shown to be viable for such a population, is based on sampling a neighborhood of units around a unit that meets a specified condition. However, the edge units produced by sampling neighborhoods have proven to limit the efficiency and applicability of adaptive cluster sampling. We propose a sampling design that is adaptive in the sense that the final sample depends on observed values, but it avoids the use of neighborhoods and the sampling of edge units. Unbiased estimators of population total and its variance are derived using Murthy's estimator. The modified two-stage sampling design is easy to implement and can be applied to a wider range of populations than adaptive cluster sampling. We evaluate the proposed sampling design by simulating sampling of two real biological populations and an artificial population for which the variable of interest took the value either 0 or 1 (e.g., indicating presence and absence of a rare event). We show that the proposed sampling design is more efficient than conventional sampling in nearly all cases. The approach used to derive estimators (Murthy's estimator) opens the door for unbiased estimators to be found for similar sequential sampling designs. ?? 2005 American Statistical Association and the International Biometric Society.

Development of Constraint Force Equation Methodology for Application to Multi-Body Dynamics Including Launch Vehicle Stage Seperation

NASA Technical Reports Server (NTRS)

Pamadi, Bandu N.; Toniolo, Matthew D.; Tartabini, Paul V.; Roithmayr, Carlos M.; Albertson, Cindy W.; Karlgaard, Christopher D.

2016-01-01

The objective of this report is to develop and implement a physics based method for analysis and simulation of multi-body dynamics including launch vehicle stage separation. The constraint force equation (CFE) methodology discussed in this report provides such a framework for modeling constraint forces and moments acting at joints when the vehicles are still connected. Several stand-alone test cases involving various types of joints were developed to validate the CFE methodology. The results were compared with ADAMS(Registered Trademark) and Autolev, two different industry standard benchmark codes for multi-body dynamic analysis and simulations. However, these two codes are not designed for aerospace flight trajectory simulations. After this validation exercise, the CFE algorithm was implemented in Program to Optimize Simulated Trajectories II (POST2) to provide a capability to simulate end-to-end trajectories of launch vehicles including stage separation. The POST2/CFE methodology was applied to the STS-1 Space Shuttle solid rocket booster (SRB) separation and Hyper-X Research Vehicle (HXRV) separation from the Pegasus booster as a further test and validation for its application to launch vehicle stage separation problems. Finally, to demonstrate end-to-end simulation capability, POST2/CFE was applied to the ascent, orbit insertion, and booster return of a reusable two-stage-to-orbit (TSTO) vehicle concept. With these validation exercises, POST2/CFE software can be used for performing conceptual level end-to-end simulations, including launch vehicle stage separation, for problems similar to those discussed in this report.

Multi-saline sample distillation apparatus for hydrogen isotope analyses : design and accuracy

USGS Publications Warehouse

Hassan, Afifa Afifi

1981-01-01

A distillation apparatus for saline water samples was designed and tested. Six samples may be distilled simultaneously. The temperature was maintained at 400 C to ensure complete dehydration of the precipitating salts. Consequently, the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated. (USGS)

The Australian longitudinal study on male health sampling design and survey weighting: implications for analysis and interpretation of clustered data.

PubMed

Spittal, Matthew J; Carlin, John B; Currier, Dianne; Downes, Marnie; English, Dallas R; Gordon, Ian; Pirkis, Jane; Gurrin, Lyle

2016-10-31

The Australian Longitudinal Study on Male Health (Ten to Men) used a complex sampling scheme to identify potential participants for the baseline survey. This raises important questions about when and how to adjust for the sampling design when analyzing data from the baseline survey. We describe the sampling scheme used in Ten to Men focusing on four important elements: stratification, multi-stage sampling, clustering and sample weights. We discuss how these elements fit together when using baseline data to estimate a population parameter (e.g., population mean or prevalence) or to estimate the association between an exposure and an outcome (e.g., an odds ratio). We illustrate this with examples using a continuous outcome (weight in kilograms) and a binary outcome (smoking status). Estimates of a population mean or disease prevalence using Ten to Men baseline data are influenced by the extent to which the sampling design is addressed in an analysis. Estimates of mean weight and smoking prevalence are larger in unweighted analyses than weighted analyses (e.g., mean = 83.9 kg vs. 81.4 kg; prevalence = 18.0 % vs. 16.7 %, for unweighted and weighted analyses respectively) and the standard error of the mean is 1.03 times larger in an analysis that acknowledges the hierarchical (clustered) structure of the data compared with one that does not. For smoking prevalence, the corresponding standard error is 1.07 times larger. Measures of association (mean group differences, odds ratios) are generally similar in unweighted or weighted analyses and whether or not adjustment is made for clustering. The extent to which the Ten to Men sampling design is accounted for in any analysis of the baseline data will depend on the research question. When the goals of the analysis are to estimate the prevalence of a disease or risk factor in the population or the magnitude of a population-level exposure-outcome association, our advice is to adopt an analysis that respects the sampling design.

An integrated multi criteria approach for landfill siting in a conflicting environmental, economical and socio-cultural area.

PubMed

Eskandari, Mahnaz; Homaee, Mehdi; Mahmodi, Shahla

2012-08-01

Landfill site selection is a complicated multi criteria land use planning that should convince all related stakeholders with different insights. This paper addresses an integrating approach for landfill siting based on conflicting opinions among environmental, economical and socio-cultural expertise. In order to gain optimized siting decision, the issue was investigated in different viewpoints. At first step based on opinion sampling and questionnaire results of 35 experts familiar with local situations, the national environmental legislations and international practices, 13 constraints and 15 factors were built in hierarchical structure. Factors divided into three environmental, economical and socio-cultural groups. In the next step, the GIS-database was developed based on the designated criteria. In the third stage, the criteria standardization and criteria weighting were accomplished. The relative importance weights of criteria and subcriteria were estimated, respectively, using analytical hierarchy process and rank ordering methods based on different experts opinions. Thereafter, by using simple additive weighting method, the suitability maps for landfill siting in Marvdasht, Iran, was evaluated in environmental, economical and socio-cultural visions. The importance of each group of criteria in its own vision was assigned to be higher than two other groups. In the fourth stage, the final suitability map was obtained after crossing three resulted maps in different visions and reported in five suitability classes for landfill construction. This map indicated that almost 1224 ha of the study area can be considered as best suitable class for landfill siting considering all visions. In the last stage, a comprehensive field visit was performed to verify the selected site obtained from the proposed model. This field inspection has confirmed the proposed integrating approach for the landfill siting. Copyright © 2012 Elsevier Ltd. All rights reserved.

Matching Expectations for Successful University Student Volunteering

ERIC Educational Resources Information Center

Paull, Megan; Omari, Maryam; MacCallum, Judith; Young, Susan; Walker, Gabrielle; Holmes, Kirsten; Haski-Leventha, Debbie; Scott, Rowena

2017-01-01

Purpose: The purpose of this paper is to demonstrate the importance of expectation formation and matching for university student volunteers and their hosts. Design/methodology/approach: This research involved a multi-stage data collection process including interviews with student volunteers, and university and host representatives from six…

Persuading Investors: Emphasizing Communication in a Finance Simulation

ERIC Educational Resources Information Center

Yest, Michael T.; Grant, Kelly A.

2013-01-01

This paper introduces a unique project to faculty seeking an interdisciplinary activity that exposes students to the necessary art of persuasive communication in the field of finance. Specifically, we have designed a multi-stage simulation in which undergraduate business students apply both finance and communication skills, specifically…

Stepfamily Enrichment Program: A Preventive Intervention for Remarried Couples

ERIC Educational Resources Information Center

Michaels, Marcia L.

2006-01-01

The Stepfamily Enrichment Program is a multi-couple group intervention intended to help stepfamilies successfully negotiate the early stages of family formation. Theory, research, and clinical findings were integrated in this intervention designed specifically for remarried couples. Emphasis is placed on strengthening and improving family…

Multi-objective aerodynamic shape optimization of small livestock trailers

NASA Astrophysics Data System (ADS)

Gilkeson, C. A.; Toropov, V. V.; Thompson, H. M.; Wilson, M. C. T.; Foxley, N. A.; Gaskell, P. H.

2013-11-01

This article presents a formal optimization study of the design of small livestock trailers, within which the majority of animals are transported to market in the UK. The benefits of employing a headboard fairing to reduce aerodynamic drag without compromising the ventilation of the animals' microclimate are investigated using a multi-stage process involving computational fluid dynamics (CFD), optimal Latin hypercube (OLH) design of experiments (DoE) and moving least squares (MLS) metamodels. Fairings are parameterized in terms of three design variables and CFD solutions are obtained at 50 permutations of design variables. Both global and local search methods are employed to locate the global minimum from metamodels of the objective functions and a Pareto front is generated. The importance of carefully selecting an objective function is demonstrated and optimal fairing designs, offering drag reductions in excess of 5% without compromising animal ventilation, are presented.

Beam-hardening correction by a surface fitting and phase classification by a least square support vector machine approach for tomography images of geological samples

NASA Astrophysics Data System (ADS)

Khan, F.; Enzmann, F.; Kersten, M.

2015-12-01

In X-ray computed microtomography (μXCT) image processing is the most important operation prior to image analysis. Such processing mainly involves artefact reduction and image segmentation. We propose a new two-stage post-reconstruction procedure of an image of a geological rock core obtained by polychromatic cone-beam μXCT technology. In the first stage, the beam-hardening (BH) is removed applying a best-fit quadratic surface algorithm to a given image data set (reconstructed slice), which minimizes the BH offsets of the attenuation data points from that surface. The final BH-corrected image is extracted from the residual data, or the difference between the surface elevation values and the original grey-scale values. For the second stage, we propose using a least square support vector machine (a non-linear classifier algorithm) to segment the BH-corrected data as a pixel-based multi-classification task. A combination of the two approaches was used to classify a complex multi-mineral rock sample. The Matlab code for this approach is provided in the Appendix. A minor drawback is that the proposed segmentation algorithm may become computationally demanding in the case of a high dimensional training data set.

Multi-stage versus single-stage inflation and deflation cycle for alternating low pressure air mattresses to prevent pressure ulcers in hospitalised patients: a randomised-controlled clinical trial.

PubMed

Demarré, L; Beeckman, D; Vanderwee, K; Defloor, T; Grypdonck, M; Verhaeghe, S

2012-04-01

The duration and the amount of pressure and shear must be reduced in order to minimize the risk of pressure ulcer development. Alternating low pressure air mattresses with multi-stage inflation and deflation cycle of the air cells have been developed to relieve pressure by sequentially inflating and deflating the air cells. Evidence about the effectiveness of this type of mattress in clinical practice is lacking. This study aimed to compare the effectiveness of an alternating low pressure air mattress that has a standard single-stage inflation and deflation cycle of the air cells with an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. A randomised controlled trial was performed in a convenience sample of 25 wards in five hospitals in Belgium. In total, 610 patients were included and randomly assigned to the experimental group (n=298) or the control group (n=312). In the experimental group, patients were allocated to an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. In the control group, patients were allocated to an alternating low pressure air mattress with a standard single-stage inflation and deflation cycle of the air cells. The outcome was defined as cumulative pressure ulcer incidence (Grade II-IV). An intention-to-treat analysis was performed. There was no significant difference in cumulative pressure ulcer incidence (Grade II-IV) between both groups (Exp.=5.7%, Contr.=5.8%, p=0.97). When patients developed a pressure ulcer, the median time was 5.0 days in the experimental group (IQR=3.0-8.5) and 8.0 days in the control group (IQR=3.0-8.5) (Mann-Whitney U-test=113, p=0.182). The probability to remain pressure ulcer free during the observation period in this trial did not differ significantly between the experimental group and the control group (log-rank χ(2)=0.013, df=1, p=0.911). An alternating low pressure air mattress with multi-stage inflation and deflation of the air cells does not result in a significantly lower pressure ulcer incidence compared to an alternating low pressure air mattress with a standard single-stage inflation and deflation cycle of the air cells. Both alternating mattress types are equally effective to prevent pressure ulcer development. © 2011 Elsevier Ltd. All rights reserved.

A Bayesian pick-the-winner design in a randomized phase II clinical trial.

PubMed

Chen, Dung-Tsa; Huang, Po-Yu; Lin, Hui-Yi; Chiappori, Alberto A; Gabrilovich, Dmitry I; Haura, Eric B; Antonia, Scott J; Gray, Jhanelle E

2017-10-24

Many phase II clinical trials evaluate unique experimental drugs/combinations through multi-arm design to expedite the screening process (early termination of ineffective drugs) and to identify the most effective drug (pick the winner) to warrant a phase III trial. Various statistical approaches have been developed for the pick-the-winner design but have been criticized for lack of objective comparison among the drug agents. We developed a Bayesian pick-the-winner design by integrating a Bayesian posterior probability with Simon two-stage design in a randomized two-arm clinical trial. The Bayesian posterior probability, as the rule to pick the winner, is defined as probability of the response rate in one arm higher than in the other arm. The posterior probability aims to determine the winner when both arms pass the second stage of the Simon two-stage design. When both arms are competitive (i.e., both passing the second stage), the Bayesian posterior probability performs better to correctly identify the winner compared with the Fisher exact test in the simulation study. In comparison to a standard two-arm randomized design, the Bayesian pick-the-winner design has a higher power to determine a clear winner. In application to two studies, the approach is able to perform statistical comparison of two treatment arms and provides a winner probability (Bayesian posterior probability) to statistically justify the winning arm. We developed an integrated design that utilizes Bayesian posterior probability, Simon two-stage design, and randomization into a unique setting. It gives objective comparisons between the arms to determine the winner.

A multi-stage heuristic algorithm for matching problem in the modified miniload automated storage and retrieval system of e-commerce

NASA Astrophysics Data System (ADS)

Wang, Wenrui; Wu, Yaohua; Wu, Yingying

2016-05-01

E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

A simple two-stage design for quantitative responses with application to a study in diabetic neuropathic pain.

PubMed

Whitehead, John; Valdés-Márquez, Elsa; Lissmats, Agneta

2009-01-01

Two-stage designs offer substantial advantages for early phase II studies. The interim analysis following the first stage allows the study to be stopped for futility, or more positively, it might lead to early progression to the trials needed for late phase II and phase III. If the study is to continue to its second stage, then there is an opportunity for a revision of the total sample size. Two-stage designs have been implemented widely in oncology studies in which there is a single treatment arm and patient responses are binary. In this paper the case of two-arm comparative studies in which responses are quantitative is considered. This setting is common in therapeutic areas other than oncology. It will be assumed that observations are normally distributed, but that there is some doubt concerning their standard deviation, motivating the need for sample size review. The work reported has been motivated by a study in diabetic neuropathic pain, and the development of the design for that trial is described in detail. Copyright 2008 John Wiley & Sons, Ltd.

An Efficient, Highly Flexible Multi-Channel Digital Downconverter Architecture

NASA Technical Reports Server (NTRS)

Goodhart, Charles E.; Soriano, Melissa A.; Navarro, Robert; Trinh, Joseph T.; Sigman, Elliott H.

2013-01-01

In this innovation, a digital downconverter has been created that produces a large (16 or greater) number of output channels of smaller bandwidths. Additionally, this design has the flexibility to tune each channel independently to anywhere in the input bandwidth to cover a wide range of output bandwidths (from 32 MHz down to 1 kHz). Both the flexibility in channel frequency selection and the more than four orders of magnitude range in output bandwidths (decimation rates from 32 to 640,000) presented significant challenges to be solved. The solution involved breaking the digital downconversion process into a two-stage process. The first stage is a 2 oversampled filter bank that divides the whole input bandwidth as a real input signal into seven overlapping, contiguous channels represented with complex samples. Using the symmetry of the sine and cosine functions in a similar way to that of an FFT (fast Fourier transform), this downconversion is very efficient and gives seven channels fixed in frequency. An arbitrary number of smaller bandwidth channels can be formed from second-stage downconverters placed after the first stage of downconversion. Because of the overlapping of the first stage, there is no gap in coverage of the entire input bandwidth. The input to any of the second-stage downconverting channels has a multiplexer that chooses one of the seven wideband channels from the first stage. These second-stage downconverters take up fewer resources because they operate at lower bandwidths than doing the entire downconversion process from the input bandwidth for each independent channel. These second-stage downconverters are each independent with fine frequency control tuning, providing extreme flexibility in positioning the center frequency of a downconverted channel. Finally, these second-stage downconverters have flexible decimation factors over four orders of magnitude The algorithm was developed to run in an FPGA (field programmable gate array) at input data sampling rates of up to 1,280 MHz. The current implementation takes a 1,280-MHz real input, and first breaks it up into seven 160-MHz complex channels, each spaced 80 MHz apart. The eighth channel at baseband was not required for this implementation, and led to more optimization. Afterwards, 16 second stage narrow band channels with independently tunable center frequencies and bandwidth settings are implemented A future implementation in a larger Xilinx FPGA will hold up to 32 independent second-stage channels.

A two-way enriched clinical trial design: combining advantages of placebo lead-in and randomized withdrawal.

PubMed

Ivanova, Anastasia; Tamura, Roy N

2015-12-01

A new clinical trial design, designated the two-way enriched design (TED), is introduced, which augments the standard randomized placebo-controlled trial with second-stage enrichment designs in placebo non-responders and drug responders. The trial is run in two stages. In the first stage, patients are randomized between drug and placebo. In the second stage, placebo non-responders are re-randomized between drug and placebo and drug responders are re-randomized between drug and placebo. All first-stage data, and second-stage data from first-stage placebo non-responders and first-stage drug responders, are utilized in the efficacy analysis. The authors developed one, two and three degrees of freedom score tests for treatment effect in the TED and give formulae for asymptotic power and for sample size computations. The authors compute the optimal allocation ratio between drug and placebo in the first stage for the TED and compare the operating characteristics of the design to the standard parallel clinical trial, placebo lead-in and randomized withdrawal designs. Two motivating examples from different disease areas are presented to illustrate the possible design considerations. © The Author(s) 2011.

A note on the efficiencies of sampling strategies in two-stage Bayesian regional fine mapping of a quantitative trait.

PubMed

Chen, Zhijian; Craiu, Radu V; Bull, Shelley B

2014-11-01

In focused studies designed to follow up associations detected in a genome-wide association study (GWAS), investigators can proceed to fine-map a genomic region by targeted sequencing or dense genotyping of all variants in the region, aiming to identify a functional sequence variant. For the analysis of a quantitative trait, we consider a Bayesian approach to fine-mapping study design that incorporates stratification according to a promising GWAS tag SNP in the same region. Improved cost-efficiency can be achieved when the fine-mapping phase incorporates a two-stage design, with identification of a smaller set of more promising variants in a subsample taken in stage 1, followed by their evaluation in an independent stage 2 subsample. To avoid the potential negative impact of genetic model misspecification on inference we incorporate genetic model selection based on posterior probabilities for each competing model. Our simulation study shows that, compared to simple random sampling that ignores genetic information from GWAS, tag-SNP-based stratified sample allocation methods reduce the number of variants continuing to stage 2 and are more likely to promote the functional sequence variant into confirmation studies. © 2014 WILEY PERIODICALS, INC.

A modified varying-stage adaptive phase II/III clinical trial design.

PubMed

Dong, Gaohong; Vandemeulebroecke, Marc

2016-07-01

Conventionally, adaptive phase II/III clinical trials are carried out with a strict two-stage design. Recently, a varying-stage adaptive phase II/III clinical trial design has been developed. In this design, following the first stage, an intermediate stage can be adaptively added to obtain more data, so that a more informative decision can be made. Therefore, the number of further investigational stages is determined based upon data accumulated to the interim analysis. This design considers two plausible study endpoints, with one of them initially designated as the primary endpoint. Based on interim results, another endpoint can be switched as the primary endpoint. However, in many therapeutic areas, the primary study endpoint is well established. Therefore, we modify this design to consider one study endpoint only so that it may be more readily applicable in real clinical trial designs. Our simulations show that, the same as the original design, this modified design controls the Type I error rate, and the design parameters such as the threshold probability for the two-stage setting and the alpha allocation ratio in the two-stage setting versus the three-stage setting have a great impact on the design characteristics. However, this modified design requires a larger sample size for the initial stage, and the probability of futility becomes much higher when the threshold probability for the two-stage setting gets smaller. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Towards a Usability and Error "Safety Net": A Multi-Phased Multi-Method Approach to Ensuring System Usability and Safety.

PubMed

Kushniruk, Andre; Senathirajah, Yalini; Borycki, Elizabeth

2017-01-01

The usability and safety of health information systems have become major issues in the design and implementation of useful healthcare IT. In this paper we describe a multi-phased multi-method approach to integrating usability engineering methods into system testing to ensure both usability and safety of healthcare IT upon widespread deployment. The approach involves usability testing followed by clinical simulation (conducted in-situ) and "near-live" recording of user interactions with systems. At key stages in this process, usability problems are identified and rectified forming a usability and technology-induced error "safety net" that catches different types of usability and safety problems prior to releasing systems widely in healthcare settings.

Comparison of Precision of Biomass Estimates in Regional Field Sample Surveys and Airborne LiDAR-Assisted Surveys in Hedmark County, Norway

NASA Technical Reports Server (NTRS)

Naesset, Erik; Gobakken, Terje; Bollandsas, Ole Martin; Gregoire, Timothy G.; Nelson, Ross; Stahl, Goeran

2013-01-01

Airborne scanning LiDAR (Light Detection and Ranging) has emerged as a promising tool to provide auxiliary data for sample surveys aiming at estimation of above-ground tree biomass (AGB), with potential applications in REDD forest monitoring. For larger geographical regions such as counties, states or nations, it is not feasible to collect airborne LiDAR data continuously ("wall-to-wall") over the entire area of interest. Two-stage cluster survey designs have therefore been demonstrated by which LiDAR data are collected along selected individual flight-lines treated as clusters and with ground plots sampled along these LiDAR swaths. Recently, analytical AGB estimators and associated variance estimators that quantify the sampling variability have been proposed. Empirical studies employing these estimators have shown a seemingly equal or even larger uncertainty of the AGB estimates obtained with extensive use of LiDAR data to support the estimation as compared to pure field-based estimates employing estimators appropriate under simple random sampling (SRS). However, comparison of uncertainty estimates under SRS and sophisticated two-stage designs is complicated by large differences in the designs and assumptions. In this study, probability-based principles to estimation and inference were followed. We assumed designs of a field sample and a LiDAR-assisted survey of Hedmark County (HC) (27,390 km2), Norway, considered to be more comparable than those assumed in previous studies. The field sample consisted of 659 systematically distributed National Forest Inventory (NFI) plots and the airborne scanning LiDAR data were collected along 53 parallel flight-lines flown over the NFI plots. We compared AGB estimates based on the field survey only assuming SRS against corresponding estimates assuming two-phase (double) sampling with LiDAR and employing model-assisted estimators. We also compared AGB estimates based on the field survey only assuming two-stage sampling (the NFI plots being grouped in clusters) against corresponding estimates assuming two-stage sampling with the LiDAR and employing model-assisted estimators. For each of the two comparisons, the standard errors of the AGB estimates were consistently lower for the LiDAR-assisted designs. The overall reduction of the standard errors in the LiDAR-assisted estimation was around 40-60% compared to the pure field survey. We conclude that the previously proposed two-stage model-assisted estimators are inappropriate for surveys with unequal lengths of the LiDAR flight-lines and new estimators are needed. Some options for design of LiDAR-assisted sample surveys under REDD are also discussed, which capitalize on the flexibility offered when the field survey is designed as an integrated part of the overall survey design as opposed to previous LiDAR-assisted sample surveys in the boreal and temperate zones which have been restricted by the current design of an existing NFI.

[Prevalence of Variants in the Apolipoprotein E (APOE) Gene in a General Population of Adults from an Urban Area of Medellin (Antioquia)].

PubMed

Arango Viana, Juan Carlos; Valencia, Ana Victoria; Páez, Ana Lucía; Montoya Gómez, Nilton; Palacio, Carlos; Arbeláez, María Patricia; Bedoya Berrío, Gabriel; García Valencia, Jenny

2014-01-01

To determine the allelic and genotype frequencies of apolipoproteine E (APOE) gene in a representative sample of the adult population of Medellin in 2010. A representative sample of the adult population of Medellin, was obtained by means of a multi-stage, stratified, conglomerate based sampling method. APOE genotyping was carried out on each of the participants. The sampling design was taken into consideration for the frequencies and association analysis. The frequencies of the APOE alleles E2, E3 and E4 were 3.9, 92.0 and 4.1%, respectively. The frequencies of the different APOE genotypes were as follows: 2/2, 0.2%; 2/3, 6.8%; 2/4, 0.6%; 3/3, 85.0%; 3/4, 7.2%, and 4/4, 0.3%. The allelic and genotype frequencies of APOE in an adult population of Medellin did not differ substantially from other series reported in South America. These data are important to determine the real impact of APOE on the population risk of several psychiatric diseases. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Evaluation of the Alaska Native Science & Engineering Program (ANSEP). Research Report

ERIC Educational Resources Information Center

Bernstein, Hamutal; Martin, Carlos; Eyster, Lauren; Anderson, Theresa; Owen, Stephanie; Martin-Caughey, Amanda

2015-01-01

The Urban Institute conducted an implementation and participant-outcomes evaluation of the Alaska Native Science & Engineering Program (ANSEP). ANSEP is a multi-stage initiative designed to prepare and support Alaska Native students from middle school through graduate school to succeed in science, technology, engineering, and math (STEM)…

Controllability in Multi-Stage Laser Ion Acceleration

NASA Astrophysics Data System (ADS)

Kawata, S.; Kamiyama, D.; Ohtake, Y.; Barada, D.; Ma, Y. Y.; Kong, Q.; Wang, P. X.; Gu, Y. J.; Li, X. F.; Yu, Q.

2015-11-01

The present paper shows a concept for a future laser ion accelerator, which should have an ion source, ion collimators, ion beam bunchers and ion post acceleration devices. Based on the laser ion accelerator components, the ion particle energy and the ion energy spectrum are controlled, and a future compact laser ion accelerator would be designed for ion cancer therapy or for ion material treatment. In this study each component is designed to control the ion beam quality. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching are successfully realized by a multi-stage laser-target interaction. A combination of each component provides a high controllability of the ion beam quality to meet variable requirements in various purposes in the laser ion accelerator. The work was partly supported by MEXT, JSPS, ASHULA project/ ILE, Osaka University, CORE (Center for Optical Research and Education, Utsunomiya University, Japan), Fudan University and CDI (Creative Dept. for Innovation) in CCRD, Utsunomiya University.

Development of Multi-slice Analytical Tool to Support BIM-based Design Process

NASA Astrophysics Data System (ADS)

Atmodiwirjo, P.; Johanes, M.; Yatmo, Y. A.

2017-03-01

This paper describes the on-going development of computational tool to analyse architecture and interior space based on multi-slice representation approach that is integrated with Building Information Modelling (BIM). Architecture and interior space is experienced as a dynamic entity, which have the spatial properties that might be variable from one part of space to another, therefore the representation of space through standard architectural drawings is sometimes not sufficient. The representation of space as a series of slices with certain properties in each slice becomes important, so that the different characteristics in each part of space could inform the design process. The analytical tool is developed for use as a stand-alone application that utilises the data exported from generic BIM modelling tool. The tool would be useful to assist design development process that applies BIM, particularly for the design of architecture and interior spaces that are experienced as continuous spaces. The tool allows the identification of how the spatial properties change dynamically throughout the space and allows the prediction of the potential design problems. Integrating the multi-slice analytical tool in BIM-based design process thereby could assist the architects to generate better design and to avoid unnecessary costs that are often caused by failure to identify problems during design development stages.

Behavioural Problems of Juvenile Street Hawkers in Uyo Metropolis, Nigeria

ERIC Educational Resources Information Center

Udoh, Nsisong A.; Joseph, Eme U.

2012-01-01

The study sought the opinions of Faculty of Education Students of University of Uyo on the behavioural problems of juvenile street hawkers in Uyo metropolis. Five research hypotheses were formulated to guide the study. This cross-sectional survey employed multi-stage random sampling technique in selecting 200 regular undergraduate students in the…

An Adaptive Staggered Dose Design for a Normal Endpoint.

PubMed

Wu, Joseph; Menon, Sandeep; Chang, Mark

2015-01-01

In a clinical trial where several doses are compared to a control, a multi-stage design that combines both the selection of the best dose and the confirmation of this selected dose is desirable. An example is the two-stage drop-the-losers or pick-the-winner design, where inferior doses are dropped after interim analysis. Selection of target dose(s) can be based on ranking of observed effects, hypothesis testing with adjustment for multiplicity, or other criteria at interim stages. A number of methods have been proposed and have made significant gains in trial efficiency. However, many of these designs started off with all doses with equal allocation and did not consider prioritizing the doses using existing dose-response information. We propose an adaptive staggered dose procedure that allows explicit prioritization of doses and applies error spending scheme that favors doses with assumed better responses. This design starts off with only a subset of the doses and adaptively adds new doses depending on interim results. Using simulation, we have shown that this design performs better in terms of increased statistical power than the drop-the-losers design given strong prior information of dose response.

A Simulated Annealing Algorithm for the Optimization of Multistage Depressed Collector Efficiency

NASA Technical Reports Server (NTRS)

Vaden, Karl R.; Wilson, Jeffrey D.; Bulson, Brian A.

2002-01-01

The microwave traveling wave tube amplifier (TWTA) is widely used as a high-power transmitting source for space and airborne communications. One critical factor in designing a TWTA is the overall efficiency. However, overall efficiency is highly dependent upon collector efficiency; so collector design is critical to the performance of a TWTA. Therefore, NASA Glenn Research Center has developed an optimization algorithm based on Simulated Annealing to quickly design highly efficient multi-stage depressed collectors (MDC).

Multi-focus image fusion and robust encryption algorithm based on compressive sensing

NASA Astrophysics Data System (ADS)

Xiao, Di; Wang, Lan; Xiang, Tao; Wang, Yong

2017-06-01

Multi-focus image fusion schemes have been studied in recent years. However, little work has been done in multi-focus image transmission security. This paper proposes a scheme that can reduce data transmission volume and resist various attacks. First, multi-focus image fusion based on wavelet decomposition can generate complete scene images and optimize the perception of the human eye. The fused images are sparsely represented with DCT and sampled with structurally random matrix (SRM), which reduces the data volume and realizes the initial encryption. Then the obtained measurements are further encrypted to resist noise and crop attack through combining permutation and diffusion stages. At the receiver, the cipher images can be jointly decrypted and reconstructed. Simulation results demonstrate the security and robustness of the proposed scheme.

Overview of NASA's Integrated Design and Engineering Analysis (IDEA)Environment

NASA Technical Reports Server (NTRS)

Robinson, Jeffrey S.; Martin John G.

2008-01-01

Historically, the design of subsonic and supersonic aircraft has been divided into separate technical disciplines (such as propulsion, aerodynamics and structures) each of which performs their design and analysis in relative isolation from others. This is possible in most cases either because the amount of interdisciplinary coupling is minimal or because the interactions can be treated as linear. The design of hypersonic airbreathing vehicles, like NASA s X-43, is quite the opposite. Such systems are dominated by strong non-linear interactions between disciplines. The design of these systems demands that a multi-disciplinary approach be taken. Furthermore, increased analytical fidelity at the conceptual design phase is highly desirable as many of the non-linearities are not captured by lower fidelity tools. Only when these systems are designed from a true multi-disciplinary perspective can the real performance benefits be achieved and complete vehicle systems be fielded. Toward this end, the Vehicle Analysis Branch at NASA Langley Research Center has been developing the Integrated Design & Engineering Analysis (IDEA) Environment. IDEA is a collaborative environment for parametrically modeling conceptual and preliminary launch vehicle configurations using the Adaptive Modeling Language (AML) as the underlying framework. The environment integrates geometry, configuration, propulsion, aerodynamics, aerothermodynamics, trajectory, closure and structural analysis into a generative, parametric, unified computational model where data is shared seamlessly between the different disciplines. Plans are also in place to incorporate life cycle analysis tools into the environment which will estimate vehicle operability, reliability and cost. IDEA is currently being funded by NASA s Hypersonics Project, a part of the Fundamental Aeronautics Program within the Aeronautics Research Mission Directorate. The environment is currently focused around a two-stage-to-orbit configuration with a turbine based combined cycle (TBCC) first stage and reusable rocket second stage. This paper provides an overview of the development of the IDEA environment, a description of the current status and detail of future plans.

Microlenses and microcameras for biomedical imaging

NASA Astrophysics Data System (ADS)

Kanhere, Aditi

Liquid lens technology is a rapidly progressing field driven by the promise of low cost fabrication, faster response, fewer mechanical elements, versatility and ease of customization for different applications. Here we present the use of liquid lenses for biomedical optics and medical imaging. I will specifically focus on our approaches towards the development of two liquid-lens optical systems -- laparoscopic cameras and 3D microscopy. The first part of this work is based on the development of a multi-camera laparoscopic imaging system with tunable focusing capability. The work attempts to find a solution to overcome many of the fundamental challenges faced by current laparoscopic imaging systems. The system is developed upon the key idea that widely spread multiple, tunable microcameras can cover a large range of vantage points and field of view (FoV) for intra-abdominal visualization. Our design features multiple tunable-focus microcameras integrated with a surgical port to provide panoramic intra-abdominal visualization with enhanced depth perception. Our system can be optically tuned to focus in on objects within a range of 5 mm to infinity, with a FoV adjustable between 36 degrees and 130 degrees. This unique approach also eliminates the requirement of an exclusive imaging port and need for navigation of cameras between ports during surgery. The second part of this report focuses on the application of tunable lenses in microscopy. Conventional wide-field microscopy is one of the most widely used optical microscopy technique. This technique typically captures a two dimensional image of a specimen. For a volumetric visualization of the sample or to enable depth scanning along the axial direction, it is necessary to move the sample relative to the fixed focal plane of the microscope objective. For this purpose, a mechanical z-scanning stage is typically employed. The stage enables the focal plane to move through the sample. Typical approaches used to achieve axial scanning are a motorized stepper stage or a piezoelectric stage. While stepper motors offer the advantage of unlimited travel distance, they suffer from hysteresis. Piezoelectric stages on the other hand, help eliminate hysteresis at the cost of the travel distance which is reduced to 100-200 mum. Both the types of stages, however, are bulky and cause vibrations and wobble in the sample due to high inertia. Additional care is required to avoid mechanical overshoots and backlash from the tip touching the sample. Additionally, for water or oil-immersion lenses, vibration of the sample stage can cause disturbance or ripples in the immersion media that can lead to significant distortion in the images. A robust alternative to the use of mechanical scanning stages is a remote focusing system that allows both the objective and the sample to be stationary. One such solution is the employment of a tunable-focus liquid lens in conjunction with a microscope objective to achieve axial scanning through a sample being imaged. Our work demonstrates the implementation of a robust, cost-effective and energy-efficient axial tuning solution for 3D microscopy based on thermo-responsive hydrogel-based tunable liquid lenses.

A simple and efficient alternative to implementing systematic random sampling in stereological designs without a motorized microscope stage.

PubMed

Melvin, Neal R; Poda, Daniel; Sutherland, Robert J

2007-10-01

When properly applied, stereology is a very robust and efficient method to quantify a variety of parameters from biological material. A common sampling strategy in stereology is systematic random sampling, which involves choosing a random sampling [corrected] start point outside the structure of interest, and sampling relevant objects at [corrected] sites that are placed at pre-determined, equidistant intervals. This has proven to be a very efficient sampling strategy, and is used widely in stereological designs. At the microscopic level, this is most often achieved through the use of a motorized stage that facilitates the systematic random stepping across the structure of interest. Here, we report a simple, precise and cost-effective software-based alternative to accomplishing systematic random sampling under the microscope. We believe that this approach will facilitate the use of stereological designs that employ systematic random sampling in laboratories that lack the resources to acquire costly, fully automated systems.

NASA's Space Launch System Development Status

NASA Technical Reports Server (NTRS)

Lyles, Garry

2014-01-01

Development of the National Aeronautics and Space Administration's (NASA's) Space Launch System (SLS) heavy lift rocket is shifting from the formulation phase into the implementation phase in 2014, a little more than 3 years after formal program establishment. Current development is focused on delivering a vehicle capable of launching 70 metric tons (t) into low Earth orbit. This "Block 1" configuration will launch the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back in December 2017, followed by its first crewed flight in 2021. SLS can evolve to a130t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. Benefits associated with its unprecedented mass and volume include reduced trip times and simplified payload design. Every SLS element achieved significant, tangible progress over the past year. Among the Program's many accomplishments are: manufacture of core stage test barrels and domes; testing of Solid Rocket Booster development hardware including thrust vector controls and avionics; planning for RS- 25 core stage engine testing; and more than 4,000 wind tunnel runs to refine vehicle configuration, trajectory, and guidance. The Program shipped its first flight hardware - the Multi-Purpose Crew Vehicle Stage Adapter (MSA) - to the United Launch Alliance for integration with the Delta IV heavy rocket that will launch an Orion test article in 2014 from NASA's Kennedy Space Center. The Program successfully completed Preliminary Design Review in 2013 and will complete Key Decision Point C in 2014. NASA has authorized the Program to move forward to Critical Design Review, scheduled for 2015 and a December 2017 first launch. The Program's success to date is due to prudent use of proven technology, infrastructure, and workforce from the Saturn and Space Shuttle programs, a streamlined management approach, and judicious use of new technologies. The result is a safe, affordable, sustainable, and evolutionary path to development of an unprecedented capability for future missions across the solar system. In an environment of economic challenges, the nationwide SLS team continues to meet ambitious budget and schedule targets. This paper will discuss SLS Program and technical accomplishments over the past year and provide a look at the milestones and challenges ahead.

A performance-oriented power transformer design methodology using multi-objective evolutionary optimization

PubMed Central

Adly, Amr A.; Abd-El-Hafiz, Salwa K.

2014-01-01

Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this methodology, which is tailored to be target performance design-oriented, quick rough estimation of transformer design specifics may be inferred. Testing of the suggested approach revealed significant qualitative and quantitative match with measured design and performance values. Details of the proposed methodology as well as sample design results are reported in the paper. PMID:26257939

A performance-oriented power transformer design methodology using multi-objective evolutionary optimization.

PubMed

Adly, Amr A; Abd-El-Hafiz, Salwa K

2015-05-01

Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this methodology, which is tailored to be target performance design-oriented, quick rough estimation of transformer design specifics may be inferred. Testing of the suggested approach revealed significant qualitative and quantitative match with measured design and performance values. Details of the proposed methodology as well as sample design results are reported in the paper.

Collins Cryocooler Design for Zero-Boil Storage of Liquid Hydrogen and Oxygen in Space

NASA Astrophysics Data System (ADS)

Segado, M. A.; Hannon, C. L.; Brisson, J. G.

2010-04-01

Several models of multi-stage cryocoolers are developed for zero-boil-off storage of liquid hydrogen and oxygen in space. The thermodynamic cycles are based on a modified Collins cycle being developed by MIT and AMTI, and each configuration is optimized for maximum efficiency by varying the mass flows, heat exchanger UA distribution, and other variables where applicable, subject to the required heat loads of 100 W at 100 K and 20 W at 25 K. By using double expanders connected in series with the heat loads in one or more stages of the cooler, we were able to achieve predicted efficiency gains of 10-24% over single expander designs.

Multi-unit Operations in Non-Nuclear Systems: Lessons Learned for Small Modular Reactors

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

OHara J. M.; Higgins, J.; DAgostino, A.

2012-01-17

The nuclear-power community has reached the stage of proposing advanced reactor designs to support power generation for decades to come. Small modular reactors (SMRs) are one approach to meet these energy needs. While the power output of individual reactor modules is relatively small, they can be grouped to produce reactor sites with different outputs. Also, they can be designed to generate hydrogen, or to process heat. Many characteristics of SMRs are quite different from those of current plants and may be operated quite differently. One difference is that multiple units may be operated by a single crew (or a singlemore » operator) from one control room. The U.S. Nuclear Regulatory Commission (NRC) is examining the human factors engineering (HFE) aspects of SMRs to support licensing reviews. While we reviewed information on SMR designs to obtain information, the designs are not completed and all of the design and operational information is not yet available. Nor is there information on multi-unit operations as envisioned for SMRs available in operating experience. Thus, to gain a better understanding of multi-unit operations we sought the lesson learned from non-nuclear systems that have experience in multi-unit operations, specifically refineries, unmanned aerial vehicles and tele-intensive care units. In this paper we report the lessons learned from these systems and the implications for SMRs.« less

Launch vehicle design and GNC sizing with ASTOS

NASA Astrophysics Data System (ADS)

Cremaschi, Francesco; Winter, Sebastian; Rossi, Valerio; Wiegand, Andreas

2018-03-01

The European Space Agency (ESA) is currently involved in several activities related to launch vehicle designs (Future Launcher Preparatory Program, Ariane 6, VEGA evolutions, etc.). Within these activities, ESA has identified the importance of developing a simulation infrastructure capable of supporting the multi-disciplinary design and preliminary guidance navigation and control (GNC) design of different launch vehicle configurations. Astos Solutions has developed the multi-disciplinary optimization and launcher GNC simulation and sizing tool (LGSST) under ESA contract. The functionality is integrated in the Analysis, Simulation and Trajectory Optimization Software for space applications (ASTOS) and is intended to be used from the early design phases up to phase B1 activities. ASTOS shall enable the user to perform detailed vehicle design tasks and assessment of GNC systems, covering all aspects of rapid configuration and scenario management, sizing of stages, trajectory-dependent estimation of structural masses, rigid and flexible body dynamics, navigation, guidance and control, worst case analysis, launch safety analysis, performance analysis, and reporting.

Thermal Analysis and Design of Multi-layer Insulation for Re-entry Aerodynamic Heating

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

2001-01-01

The combined radiation/conduction heat transfer in high-temperature multi-layer insulations was modeled using a finite volume numerical model. The numerical model was validated by comparison with steady-state effective thermal conductivity measurements, and by transient thermal tests simulating re-entry aerodynamic heating conditions. A design of experiments technique was used to investigate optimum design of multi-layer insulations for re-entry aerodynamic heating. It was found that use of 2 mm foil spacing and locating the foils near the hot boundary with the top foil 2 mm away from the hot boundary resulted in the most effective insulation design. A 76.2 mm thick multi-layer insulation using 1, 4, or 16 foils resulted in 2.9, 7.2, or 22.2 percent mass per unit area savings compared to a fibrous insulation sample at the same thickness, respectively.

Evaluation of World Health Organization Multi-Professional Patient Safety Curriculum Topics in Nursing Education: Pre-test, post-test, none-experimental study.

PubMed

Mansour, Mansour; Skull, Alice; Parker, Michael

2015-01-01

The Multi-professional Patient Safety Curriculum Guide was launched by the World Health Organization to develop a patient safety-friendly curriculum in health education. The aim of this study was to evaluate the impact of teaching related to two topics from the Patient Safety Curriculum Guide on student nurses' knowledge and attitudes toward patient safety. A pretest, posttest, nonexperimental design was used. Patient safety education questionnaires were distributed to a convenience sample of 181 nursing students before the intervention, and 141 questionnaires after the intervention in one university in the East of England. The intervention consisted of two face-to-face lectures and one facilitated group work discussion. Seventy-one responses from pre- and posttest stages were matched. Paired t test, McNemar's test, and frequency measures were used for data analysis. The findings suggest that there are statistically significant differences in the subscales of the error and patient safety and personal influence over safety. The differences in the students' answers on patient safety knowledge before and after the interventions were not statistically significant. Although the student nurses highly commended the teaching delivered in this study, the use of experimental design in future curriculum evaluation may provide a more complementary insight to the findings of this study. Copyright © 2015 Elsevier Inc. All rights reserved.

Epidemiology of Transfusion-Transmitted Infections Among Multi-Transfused Patients in Seven Hospitals in Peru

DTIC Science & Technology

2005-01-01

locate jcv Epidemiology of transfusion-transmitted infections among multi-transfused patients in seven hospitals in Peru 1 VA. Laguna-Torres a...and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru Study design: A cross- sectional multi-center study...was conducted across seven major hospitals in Peru fi’om February 2003 to September 2004 Self-reported behavior lntbrmatlon (medical procedures

A binary logistic regression model with complex sampling design of unmet need for family planning among all women aged (15-49) in Ethiopia.

PubMed

Workie, Demeke Lakew; Zike, Dereje Tesfaye; Fenta, Haile Mekonnen; Mekonnen, Mulusew Admasu

2017-09-01

Unintended pregnancy related to unmet need is a worldwide problem that affects societies. The main objective of this study was to identify the prevalence and determinants of unmet need for family planning among women aged (15-49) in Ethiopia. The Performance Monitoring and Accountability2020/Ethiopia was conducted in April 2016 at round-4 from 7494 women with two-stage-stratified sampling. Bi-variable and multi-variable binary logistic regression model with complex sampling design was fitted. The prevalence of unmet-need for family planning was 16.2% in Ethiopia. Women between the age range of 15-24 years were 2.266 times more likely to have unmet need family planning compared to above 35 years. Women who were currently married were about 8 times more likely to have unmet need family planning compared to never married women. Women who had no under-five child were 0.125 times less likely to have unmet need family planning compared to those who had more than two-under-5. The key determinants of unmet need family planning in Ethiopia were residence, age, marital-status, education, household members, birth-events and number of under-5 children. Thus the Government of Ethiopia would take immediate steps to address the causes of high unmet need for family planning among women.

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.

Multi-stage internal gear/turbine fuel pump

DOEpatents

Maier, Eugen; Raney, Michael Raymond

2004-07-06

A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.

Oil-free centrifugal hydrogen compression technology demonstration

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

Heshmat, Hooshang

2014-05-31

One of the key elements in realizing a mature market for hydrogen vehicles is the deployment of a safe and efficient hydrogen production and delivery infrastructure on a scale that can compete economically with current fuels. The challenge, however, is that hydrogen, being the lightest and smallest of gases with a lower viscosity and density than natural gas, readily migrates through small spaces and is difficult to compresses efficiently. While efficient and cost effective compression technology is crucial to effective pipeline delivery of hydrogen, the compression methods used currently rely on oil lubricated positive displacement (PD) machines. PD compression technologymore » is very costly, has poor reliability and durability, especially for components subjected to wear (e.g., valves, rider bands and piston rings) and contaminates hydrogen with lubricating fluid. Even so called “oil-free” machines use oil lubricants that migrate into and contaminate the gas path. Due to the poor reliability of PD compressors, current hydrogen producers often install duplicate units in order to maintain on-line times of 98-99%. Such machine redundancy adds substantially to system capital costs. As such, DOE deemed that low capital cost, reliable, efficient and oil-free advanced compressor technologies are needed. MiTi’s solution is a completely oil-free, multi-stage, high-speed, centrifugal compressor designed for flow capacity of 500,000 kg/day with a discharge pressure of 1200 psig. The design employs oil-free compliant foil bearings and seals to allow for very high operating speeds, totally contamination free operation, long life and reliability. This design meets the DOE’s performance targets and achieves an extremely aggressive, specific power metric of 0.48 kW-hr/kg and provides significant improvements in reliability/durability, energy efficiency, sealing and freedom from contamination. The multi-stage compressor system concept has been validated through full scale performance testing of a single stage with helium similitude gas at full speed in accordance with ASME PTC-10. The experimental results indicated that aerodynamic performance, with respect to compressor discharge pressure, flow, power and efficiency exceeded theoretical prediction. Dynamic testing of a simulated multistage centrifugal compressor was also completed under a parallel program to validate the integrity and viability of the system concept. The results give strong confidence in the feasibility of the multi-stage design for use in hydrogen gas transportation and delivery from production locations to point of use.« less

Deep and Surface Processing of Instructor's Feedback in an Online Course

ERIC Educational Resources Information Center

Huang, Kun; Ge, Xun; Law, Victor

2017-01-01

This study investigated the characteristics of deep and surface approaches to learning in online students' responses to instructor's qualitative feedback given to a multi-stage, ill-structured design project. Further, the study examined the relationships between approaches to learning and two learner characteristics: epistemic beliefs (EB) and…

Building Alaska's Science and Engineering Pipeline: Evaluation of the Alaska Native Science & Engineering Program

ERIC Educational Resources Information Center

Bernstein, Hamutal; Martin, Carlos; Eyster, Lauren; Anderson, Theresa; Owen, Stephanie; Martin-Caughey, Amanda

2015-01-01

The Urban Institute conducted an implementation and participant-outcomes evaluation of the Alaska Native Science & Engineering Program (ANSEP). ANSEP is a multi-stage initiative designed to prepare and support Alaska Native students from middle school through graduate school to succeed in science, technology, engineering, and math (STEM)…

Reflexive Deliberation in International Research Collaboration: Minimising Risk and Maximising Opportunity

ERIC Educational Resources Information Center

Brew, Angela; Boud, David; Lucas, Lisa; Crawford, Karin

2013-01-01

International research collaboration raises questions about how groups from different national and institutional contexts can work together for common ends. This paper uses issues that have arisen in carrying out the first stage of an international research project to discuss a framework designed to map different kinds of multi-national research…

Design optimization of aircraft landing gear assembly under dynamic loading

NASA Astrophysics Data System (ADS)

Wong, Jonathan Y. B.

As development cycles and prototyping iterations begin to decrease in the aerospace industry, it is important to develop and improve practical methodologies to meet all design metrics. This research presents an efficient methodology that applies high-fidelity multi-disciplinary design optimization techniques to commercial landing gear assemblies, for weight reduction, cost savings, and structural performance dynamic loading. Specifically, a slave link subassembly was selected as the candidate to explore the feasibility of this methodology. The design optimization process utilized in this research was sectioned into three main stages: setup, optimization, and redesign. The first stage involved the creation and characterization of the models used throughout this research. The slave link assembly was modelled with a simplified landing gear test, replicating the behavior of the physical system. Through extensive review of the literature and collaboration with Safran Landing Systems, dynamic and structural behavior for the system were characterized and defined mathematically. Once defined, the characterized behaviors for the slave link assembly were then used to conduct a Multi-Body Dynamic (MBD) analysis to determine the dynamic and structural response of the system. These responses were then utilized in a topology optimization through the use of the Equivalent Static Load Method (ESLM). The results of the optimization were interpreted and later used to generate improved designs in terms of weight, cost, and structural performance under dynamic loading in stage three. The optimized designs were then validated using the model created for the MBD analysis of the baseline design. The design generation process employed two different approaches for post-processing the topology results produced. The first approach implemented a close replication of the topology results, resulting in a design with an overall peak stress increase of 74%, weight savings of 67%, and no apparent cost savings due to complex features present in the design. The second design approach focused on realizing reciprocating benefits for cost and weight savings. As a result, this design was able to achieve an overall peak stress increase of 6%, weight and cost savings of 36%, and 60%, respectively.

Family Functioning, Identity Formation, and the Ability of Conflict Resolution among Adolescents

ERIC Educational Resources Information Center

Kiani, Behnaz; Hojatkhah, Seyed Mohsen; Torabi-Nami, Mohammad

2016-01-01

Family is perhaps the most influential system in individuals' life in which various behaviors are learnt. Family functioning refers to the ability of family to meet its responsibilities. The present correlation study used a multi-stage cluster sampling method to recruit 686 subjects including 338 males and 348 females from all high school students…

Breast Self Examination Practice among Female Students of Tertiary Institutions

ERIC Educational Resources Information Center

Agbonifoh, Julia Adesua

2016-01-01

Against the background of the dangers posed by breast cancer world-wide, and the importance of its early detection and therefore breast self examination (BSE), this study investigated the practice of BSE among female students in tertiary institutions in Edo state. A sample of 723 participants selected through a combination of multi-stage,…

Young People's Expressed Needs for Comprehensive Sexuality Education in Ecuadorian Schools

ERIC Educational Resources Information Center

Castillo Nuñez, Jessica; Derluyn, Ilse; Valcke, Martin

2018-01-01

This study analyses the expressed sexuality education needs of young people from Azuay, a region of Ecuador characterised by a large proportion of young people whose parents have migrated abroad, a group often considered at risk to developing of sexual health problems. Multi-stage stratified cluster sampling was used to recruit young people aged…

Causal Factors Influencing Adversity Quotient of Twelfth Grade and Third-Year Vocational Students

ERIC Educational Resources Information Center

Pangma, Rachapoom; Tayraukham, Sombat; Nuangchalerm, Prasart

2009-01-01

Problem statement: The aim of this research was to study the causal factors influencing students' adversity between twelfth grade and third-year vocational students in Sisaket province, Thailand. Six hundred and seventy two of twelfth grade and 376 third-year vocational students were selected by multi-stage random sampling techniques. Approach:…

Teacher Use of Data to Guide Instructional Practice in Elementary Schools

ERIC Educational Resources Information Center

Burrows, Debra C.

2011-01-01

This descriptive study focused on the degree to which data-driven decision making as envisioned by the NCLB legislation was actually occurring in the elementary schools studied. A multi-stage random sample of six Pennsylvania school districts out of 19 located within the service area of Pennsylvania Intermediate Unit #17, one of 29 regional…

A Chondrule from the Mokoia (CV3) Chondrite with Anomalously Low 26Mg*: Evidence for a Multi-Stage History-

NASA Astrophysics Data System (ADS)

Claydon, J. L.; Elliott, T.; Coath, C. D.; Chen, H. W.; Taylor, C. A.; Russell, S. S.

2015-07-01

MC-ICP-MS measurements of Mg isotopes in chondrule MOK13B reveal that it may have formed from low-Al/Mg material that underwent chemical fractionation to increase Al/Mg after decay of 26-Al, or it may sample a region with anomalous Al or Mg isotopes.

How to Classify the Diversity of Seventh Grade Students' Mathematical Process Skills: An Application of Latent Profile Analysis

ERIC Educational Resources Information Center

Kaosa-ard, Chanapat; Erawan, Waraporn; Damrongpanit, Suntonrapot; Suksawang, Poonpong

2015-01-01

The researcher applied latent profile analysis to study the difference of the students' mathematical process skill. These skills are problem solving skills, reasoning skills, communication and presentation skills, connection knowledge skills, and creativity skills. Samples were 2,485 seventh-grade students obtained from Multi-stage Random…

Do Human-Figure Drawings of Children and Adolescents Mirror Their Cognitive Style and Self-Esteem?

ERIC Educational Resources Information Center

Dey, Anindita; Ghosh, Paromita

2016-01-01

The investigation probed relationships among human-figure drawing, field-dependent-independent cognitive style and self-esteem of 10-15 year olds. It also attempted to predict human-figure drawing scores of participants based on their field-dependence-independence and self-esteem. Area, stratified and multi-stage random sampling were used to…

IMPACT OF LEAD ACID BATTERIES AND CADMIUM STABILIZERS ON INCINERATOR EMISSIONS

EPA Science Inventory

The Waste Analysis Sampling, Testing and Evaluation (WASTE) Program is a multi-year, multi-disciplinary program designed to elicit the source and fate of environmentally significant trace materials as a solid waste progresses through management processes. s part of the WASTE Prog...

Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

PubMed Central

Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

2016-01-01

There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

Pollutant removal in a multi-stage municipal wastewater treatment system comprised of constructed wetlands and a maturation pond, in a temperate climate.

PubMed

Rivas, A; Barceló-Quintal, I; Moeller, G E

2011-01-01

A multi-stage municipal wastewater treatment system is proposed to comply with Mexican standards for discharge into receiving water bodies. The system is located in Santa Fe de la Laguna, Mexico, an area with a temperate climate. It was designed for 2,700 people equivalent (259.2 m3/d) and consists of a preliminary treatment, a septic tank as well as two modules operating in parallel, each consisting of a horizontal subsurface-flow wetland, a maturation pond and a vertical flow polishing wetland. After two years of operation, on-site research was performed. An efficient biochemical oxygen demand (BOD5) (94-98%), chemical oxygen demand (91-93%), total suspended solids (93-97%), total Kjeldahl nitrogen (56-88%) and fecal coliform (4-5 logs) removal was obtained. Significant phosphorus removal was not accomplished in this study (25-52%). Evapotranspiration was measured in different treatment units. This study demonstrates that during the dry season wastewater treatment by this multi-stage system cannot comply with the limits established by Mexican standards for receiving water bodies type 'C'. However, it has demonstrated the system's potential for less restrictive uses such as agricultural irrigation, recreation and provides the opportunity for wastewater treatment in rural areas without electric energy.

Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

NASA Astrophysics Data System (ADS)

Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

2016-08-01

There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

Helium process cycle

DOEpatents

Ganni, Venkatarao

2008-08-12

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Helium process cycle

DOEpatents

Ganni, Venkatarao

2007-10-09

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Simulation and Analyses of Multi-Body Separation in Launch Vehicle Staging Environment

NASA Technical Reports Server (NTRS)

Pamadi, Bandu N.; Hotchko, Nathaniel J.; Samareh, Jamshid; Covell, Peter F.; Tartabini, Paul V.

2006-01-01

The development of methodologies, techniques, and tools for analysis and simulation of multi-body separation is critically needed for successful design and operation of next generation launch vehicles. As a part of this activity, ConSep simulation tool is being developed. ConSep is a generic MATLAB-based front-and-back-end to the commercially available ADAMS. solver, an industry standard package for solving multi-body dynamic problems. This paper discusses the 3-body separation capability in ConSep and its application to the separation of the Shuttle Solid Rocket Boosters (SRBs) from the External Tank (ET) and the Orbiter. The results are compared with STS-1 flight data.

A multi-level model of emerging technology: An empirical study of the evolution of biotechnology from 1976 to 2003

PubMed Central

van Witteloostuijn, Arjen

2018-01-01

In this paper, we develop an ecological, multi-level model that can be used to study the evolution of emerging technology. More specifically, by defining technology as a system composed of a set of interacting components, we can build upon the argument of multi-level density dependence from organizational ecology to develop a distribution-independent model of technological evolution. This allows us to distinguish between different stages of component development, which provides more insight into the emergence of stable component configurations, or dominant designs. We validate our hypotheses in the biotechnology industry by using patent data from the USPTO from 1976 to 2003. PMID:29795575

Small Launch Vehicle Design Approaches: Clustered Cores Compared with Multi-Stage Inline Concepts

NASA Technical Reports Server (NTRS)

Waters, Eric D.; Beers, Benjamin; Esther, Elizabeth; Philips, Alan; Threet, Grady E., Jr.

2013-01-01

In an effort to better define small launch vehicle design options two approaches were investigated from the small launch vehicle trade space. The primary focus was to evaluate a clustered common core design against a purpose built inline vehicle. Both designs focused on liquid oxygen (LOX) and rocket propellant grade kerosene (RP-1) stages with the terminal stage later evaluated as a LOX/methane (CH4) stage. A series of performance optimization runs were done in order to minimize gross liftoff weight (GLOW) including alternative thrust levels, delivery altitude for payload, vehicle length to diameter ratio, alternative engine feed systems, re-evaluation of mass growth allowances, passive versus active guidance systems, and rail and tower launch methods. Additionally manufacturability, cost, and operations also play a large role in the benefits and detriments for each design. Presented here is the Advanced Concepts Office's Earth to Orbit Launch Team methodology and high level discussion of the performance trades and trends of both small launch vehicle solutions along with design philosophies that shaped both concepts. Without putting forth a decree stating one approach is better than the other; this discussion is meant to educate the community at large and let the reader determine which architecture is truly the most economical; since each path has such a unique set of limitations and potential payoffs.

eDNAoccupancy: An R package for multi-scale occupancy modeling of environmental DNA data

USGS Publications Warehouse

Dorazio, Robert; Erickson, Richard A.

2017-01-01

In this article we describe eDNAoccupancy, an R package for fitting Bayesian, multi-scale occupancy models. These models are appropriate for occupancy surveys that include three, nested levels of sampling: primary sample units within a study area, secondary sample units collected from each primary unit, and replicates of each secondary sample unit. This design is commonly used in occupancy surveys of environmental DNA (eDNA). eDNAoccupancy allows users to specify and fit multi-scale occupancy models with or without covariates, to estimate posterior summaries of occurrence and detection probabilities, and to compare different models using Bayesian model-selection criteria. We illustrate these features by analyzing two published data sets: eDNA surveys of a fungal pathogen of amphibians and eDNA surveys of an endangered fish species.

Computational design of protein antigens that interact with the CDR H3 loop of HIV broadly neutralizing antibody 2F5

PubMed Central

Azoitei, M.L.; Ban, Y.A.; Kalyuzhny, O.; Guenaga, J.; Schroeter, A.; Porter, J.; Wyatt, R.; Schief, W.R.

2015-01-01

Rational design of proteins with novel binding specificities and increased affinity is one of the major goals of computational protein design. Epitope-scaffolds are a new class of antigens engineered by transplanting viral epitopes of pre-defined structure to protein scaffolds, or by building protein scaffolds around such epitopes. Epitope-scaffolds are of interest as vaccine components to attempt to elicit neutralizing antibodies targeting the specified epitope. In this study we developed a new computational protocol, MultiGraft Interface, that transplants epitopes but also designs additional scaffold features outside the epitope to enhance antibody-binding specificity and potentially influence the specificity of elicited antibodies. We employed MultiGraft Interface to engineer novel epitope-scaffolds that display the known epitope of HIV-1 neutralizing antibody 2F5 and that also interact with the functionally important CDR H3 antibody loop. MultiGraft Interface generated an epitope-scaffold that bound 2F5 with sub-nanomolar affinity (KD = 400 pM) and that interacted with the antibody CDR H3 loop through computationally designed contacts. Substantial structural modifications were necessary to engineer this antigen, with the 2F5 epitope replacing a helix in the native scaffold and with 15% of the native scaffold sequence being modified in the design stage. This epitope-scaffold represents a successful example of rational protein backbone engineering and protein-protein interface design and could prove useful in the field of HIV vaccine design. MultiGraft Interface can be generally applied to engineer novel binding partners with altered specificity and optimized affinity. PMID:25043744

Optimal design of near-Earth asteroid sample-return trajectories in the Sun-Earth-Moon system

NASA Astrophysics Data System (ADS)

He, Shengmao; Zhu, Zhengfan; Peng, Chao; Ma, Jian; Zhu, Xiaolong; Gao, Yang

2016-08-01

In the 6th edition of the Chinese Space Trajectory Design Competition held in 2014, a near-Earth asteroid sample-return trajectory design problem was released, in which the motion of the spacecraft is modeled in multi-body dynamics, considering the gravitational forces of the Sun, Earth, and Moon. It is proposed that an electric-propulsion spacecraft initially parking in a circular 200-km-altitude low Earth orbit is expected to rendezvous with an asteroid and carry as much sample as possible back to the Earth in a 10-year time frame. The team from the Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences has reported a solution with an asteroid sample mass of 328 tons, which is ranked first in the competition. In this article, we will present our design and optimization methods, primarily including overall analysis, target selection, escape from and capture by the Earth-Moon system, and optimization of impulsive and low-thrust trajectories that are modeled in multi-body dynamics. The orbital resonance concept and lunar gravity assists are considered key techniques employed for trajectory design. The reported solution, preliminarily revealing the feasibility of returning a hundreds-of-tons asteroid or asteroid sample, envisions future space missions relating to near-Earth asteroid exploration.

A study on the aerodynamic characteristics of airfoil in the flapping adjustment stage during forward flight

NASA Astrophysics Data System (ADS)

Luo, Pan; Zhang, Xingwei; Huang, Panpan; Xie, Lingwang

2017-10-01

The aim of this study is to investigate the aerodynamic characteristics of a flapping airfoil in the adjustment stage between two specific flight patterns during the forward flight. Four flapping movement models in adjustment stage are firstly established by using the multi-objective optimization algorithm. Then, a numerical experiment is carried out by using finite volume method to solve the two-dimensional time-dependent incompressible Navier-Stokes equations. The attack angles are selected from -5° to 7.5° with an increase of 2.5°. The results are systematically analyzed and special attention is paid to the corresponding changes of aerodynamic forces, vortex shedding mechanism in the wake structure and thrust efficiency. Present results show that output aerodynamic performance of flapping airfoil can be improved by the increasement of amplitude and frequency in the flapping adjustment stage, which further validates and complements previous studies. Moreover, it is also show that the manner using multi-objective optimization algorithm to generate a movement model in adjustment stage, to connect other two specific plunging motions, is a feasible and effective method. Current study is dedicated to providing some helpful references for the design and control of artificial flapping wing air vehicles.

Two-stage phase II oncology designs using short-term endpoints for early stopping.

PubMed

Kunz, Cornelia U; Wason, James Ms; Kieser, Meinhard

2017-08-01

Phase II oncology trials are conducted to evaluate whether the tumour activity of a new treatment is promising enough to warrant further investigation. The most commonly used approach in this context is a two-stage single-arm design with binary endpoint. As for all designs with interim analysis, its efficiency strongly depends on the relation between recruitment rate and follow-up time required to measure the patients' outcomes. Usually, recruitment is postponed after the sample size of the first stage is achieved up until the outcomes of all patients are available. This may lead to a considerable increase of the trial length and with it to a delay in the drug development process. We propose a design where an intermediate endpoint is used in the interim analysis to decide whether or not the study is continued with a second stage. Optimal and minimax versions of this design are derived. The characteristics of the proposed design in terms of type I error rate, power, maximum and expected sample size as well as trial duration are investigated. Guidance is given on how to select the most appropriate design. Application is illustrated by a phase II oncology trial in patients with advanced angiosarcoma, which motivated this research.

Kinetic analysis of manure pyrolysis and combustion processes.

PubMed

Fernandez-Lopez, M; Pedrosa-Castro, G J; Valverde, J L; Sanchez-Silva, L

2016-12-01

Due to the depletion of fossil fuel reserves and the environmental issues derived from their use, biomass seems to be an excellent source of renewable energy. In this work, the kinetics of the pyrolysis and combustion of three different biomass waste samples (two dairy manure samples before (Pre) and after (Dig R) anaerobic digestion and one swine manure sample (SW)) was studied by means of thermogravimetric analysis. In this work, three iso-conversional methods (Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS)) were compared with the Coats-Redfern method. The E a values of devolatilization stages were in the range of 152-170kJ/mol, 148-178kJ/mol and 156-209kJ/mol for samples Pre, Dig R and SW, respectively. Concerning combustion process, char oxidation stages showed lower E a values than that obtained for the combustion devolatilization stage, being in the range of 140-175kJ/mol, 178-199kJ/mol and 122-144kJ/mol for samples Pre, Dig R and SW, respectively. These results were practically the same for samples Pre and Dig R, which means that the kinetics of the thermochemical processes were not affected by anaerobic digestion. Finally, the distributed activation energy model (DAEM) and the pseudo-multi component stage model (PMSM) were applied to predict the weight loss curves of pyrolysis and combustion. DAEM was the best model that fitted the experimental data. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Chen, Yixing; Zhang, Jianshun; Pelken, Michael

Executive Summary The objective of this study was to develop a “Virtual Design Studio (VDS)”: a software platform for integrated, coordinated and optimized design of green building systems with low energy consumption, high indoor environmental quality (IEQ), and high level of sustainability. This VDS is intended to assist collaborating architects, engineers and project management team members throughout from the early phases to the detailed building design stages. It can be used to plan design tasks and workflow, and evaluate the potential impacts of various green building strategies on the building performance by using the state of the art simulation toolsmore » as well as industrial/professional standards and guidelines for green building system design. Engaged in the development of VDS was a multi-disciplinary research team that included architects, engineers, and software developers. Based on the review and analysis of how existing professional practices in building systems design operate, particularly those used in the U.S., Germany and UK, a generic process for performance-based building design, construction and operation was proposed. It distinguishes the whole process into five distinct stages: Assess, Define, Design, Apply, and Monitoring (ADDAM). The current VDS is focused on the first three stages. The VDS considers building design as a multi-dimensional process, involving multiple design teams, design factors, and design stages. The intersection among these three dimensions defines a specific design task in terms of “who”, “what” and “when”. It also considers building design as a multi-objective process that aims to enhance the five aspects of performance for green building systems: site sustainability, materials and resource efficiency, water utilization efficiency, energy efficiency and impacts to the atmospheric environment, and IEQ. The current VDS development has been limited to energy efficiency and IEQ performance, with particular focus on evaluating thermal performance, air quality and lighting environmental quality because of their strong interaction with the energy performance of buildings. The VDS software framework contains four major functions: 1) Design coordination: It enables users to define tasks using the Input-Process-Output flow approach, which specifies the anticipated activities (i.e., the process), required input and output information, and anticipated interactions with other tasks. It also allows task scheduling to define the work flow, and sharing of the design data and information via the internet. 2) Modeling and simulation: It enables users to perform building simulations to predict the energy consumption and IEQ conditions at any of the design stages by using EnergyPlus and a combined heat, air, moisture and pollutant simulation (CHAMPS) model. A method for co-simulation was developed to allow the use of both models at the same time step for the combined energy and indoor air quality analysis. 3) Results visualization: It enables users to display a 3-D geometric design of the building by reading BIM (building information model) file generated by design software such as SketchUp, and the predicted results of heat, air, moisture, pollutant and light distributions in the building. 4) Performance evaluation: It enables the users to compare the performance of a proposed building design against a reference building that is defined for the same type of buildings under the same climate condition, and predicts the percent of improvements over the minimum requirements specified in ASHRAE Standard 55-2010, 62.1-2010 and 90.1-2010. An approach was developed to estimate the potential impact of a design factor on the whole building performance, and hence can assist the user to identify areas that have most pay back for investment. The VDS software was developed by using C++ with the conventional Model, View and Control (MVC) software architecture. The software has been verified by using a simple 3-zone case building. The application of the VDS concepts and framework for building design and performance analysis has been illustrated by using a medium-sized, five story office building that received LEED Platinum Certification from USGBC.« less

Photonic Breast Tomography and Tumor Aggressiveness Assessment

DTIC Science & Technology

2012-07-01

c) Raw Image 11 The entrance face of the slab sample (source plane) was illuminated by a 100-mW 790-nm diode laser beam. The multi-source...schematically shown in Figure 6. A 10mW 785 nm diode laser beam was used to illuminate the first sample, while a 100mW 785 nm diode laser beam was used for the...signal transmitting narrow-band filter; TS = translation stage; CCD = charge cou- pled device; and PC = computer. Continuous wave 790-nm diode laser

The Dark Energy Spectroscopic Instrument (DESI)

NASA Astrophysics Data System (ADS)

Flaugher, Brenna; Bebek, Chris

2014-07-01

The Dark Energy Spectroscopic Instrument (DESI) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar spectroscopic redshift survey. The DESI instrument consists of a new wide-field (3.2 deg. linear field of view) corrector plus a multi-object spectrometer with up to 5000 robotically positioned optical fibers and will be installed at prime focus on the Mayall 4m telescope at Kitt Peak, Arizona. The fibers feed 10 three-arm spectrographs producing spectra that cover a wavelength range from 360-980 nm and have resolution of 2000-5500 depending on the wavelength. The DESI instrument is designed for a 14,000 sq. deg. multi-year survey of targets that trace the evolution of dark energy out to redshift 3.5 using the redshifts of luminous red galaxies (LRGs), emission line galaxies (ELGs) and quasars. DESI is the successor to the successful Stage-III BOSS spectroscopic redshift survey and complements imaging surveys such as the Stage-III Dark Energy Survey (DES, currently operating) and the Stage-IV Large Synoptic Survey Telescope (LSST, planned start early in the next decade).

Designing Interactive Electronic Module in Chemistry Lessons

NASA Astrophysics Data System (ADS)

Irwansyah, F. S.; Lubab, I.; Farida, I.; Ramdhani, M. A.

2017-09-01

This research aims to design electronic module (e-module) oriented to the development of students’ chemical literacy on the solution colligative properties material. This research undergoes some stages including concept analysis, discourse analysis, storyboard design, design development, product packaging, validation, and feasibility test. Overall, this research undertakes three main stages, namely, Define (in the form of preliminary studies); Design (designing e-module); Develop (including validation and model trial). The concept presentation and visualization used in this e-module is oriented to chemical literacy skills. The presentation order carries aspects of scientific context, process, content, and attitude. Chemists and multi media experts have done the validation to test the initial quality of the products and give a feedback for the product improvement. The feasibility test results stated that the content presentation and display are valid and feasible to be used with the value of 85.77% and 87.94%. These values indicate that this e-module oriented to students’ chemical literacy skills for the solution colligative properties material is feasible to be used.

The influence of microwave-assisted drying techniques on the rehydration behavior of blueberries (Vaccinium corymbosum L.).

PubMed

Zielinska, Magdalena; Markowski, Marek

2016-04-01

The aim of this study was to determine the effect of: (a) different drying methods, (b) hot air temperature in a convection oven, and (c) the moisture content of fruits dehydrated by multi-stage drying which involves a transition between different stages of drying, on the rehydration kinetics of dry blueberries. Models describing rehydration kinetics were also studied. Blueberries dehydrated by multi-stage microwave-assisted drying, which involved a hot air pre-drying step at 80 °C until the achievement of a moisture content of 1.95 kg H2O kg(-1)DM, were characterized by significantly higher rates of initial and successive rehydration as well as smaller initial loss of soluble solids in comparison with the samples dried by other methods. The highest initial rehydration rate and the smallest loss of soluble solids after 30 min of soaking were determined at 0.46 min(-1) and 0.29 kg DM kg(-1)DM, respectively. The Peleg model and the first-order-kinetic model fit the experimental data well. Copyright © 2015 Elsevier Ltd. All rights reserved.

Expression of endogenous proteins in maize hybrids in a multi-location field trial in India.

PubMed

Gutha, Linga R; Purushottam, Divakar; Veeramachaneni, Aruna; Tigulla, Sarita; Kodappully, Vikas; Enjala, Chandana; Rajput, Hitendrasinh; Anderson, Jennifer; Hong, Bonnie; Schmidt, Jean; Bagga, Shveta

2018-05-17

Genetically modified (GM) crops undergo large scale multi-location field trials to characterize agronomics, composition, and the concentration of newly expressed protein(s) [herein referred to as transgenic protein(s)]. The concentration of transgenic proteins in different plant tissues and across the developmental stages of the plant is considered in the safety assessment of GM crops. Reference or housekeeping proteins are expected to maintain a relatively stable expression pattern in healthy plants given their role in cellular functions. Understanding the effects of genotype, growth stage and location on the concentration of endogenous housekeeping proteins may provide insight into the contribution these factors could have on transgenic protein concentrations in GM crops. The concentrations of three endogenous proteins (actin, elongation factor 1-alpha, and glyceraldehyde 3-phosphate dehydrogenase) were measured in several different maize hybrids grown across multiple field locations over 2 years. Leaf samples were collected from healthy plants at three developmental stages across the growing seasons, and protein concentrations were quantified by indirect enzyme-linked immunosorbent assay (ELISA) for each protein. In general, the concentrations of these three endogenous proteins were relatively consistent across hybrid backgrounds, when compared within one growth stage and location (2-26%CV), whereas the concentrations of proteins in the same hybrid and growth stage across different locations were more variable (12-64%CV). In general, the protein concentrations in 2013 and 2014 show similar trends in variability. Some degree of variability in protein concentrations should be expected for both transgenic and endogenous plant-expressed proteins. In the case of GM crops, the potential variation in protein concentrations due to location effects is captured in the current model of multi-location field testing.

Improving the accuracy of livestock distribution estimates through spatial interpolation.

PubMed

Bryssinckx, Ward; Ducheyne, Els; Muhwezi, Bernard; Godfrey, Sunday; Mintiens, Koen; Leirs, Herwig; Hendrickx, Guy

2012-11-01

Animal distribution maps serve many purposes such as estimating transmission risk of zoonotic pathogens to both animals and humans. The reliability and usability of such maps is highly dependent on the quality of the input data. However, decisions on how to perform livestock surveys are often based on previous work without considering possible consequences. A better understanding of the impact of using different sample designs and processing steps on the accuracy of livestock distribution estimates was acquired through iterative experiments using detailed survey. The importance of sample size, sample design and aggregation is demonstrated and spatial interpolation is presented as a potential way to improve cattle number estimates. As expected, results show that an increasing sample size increased the precision of cattle number estimates but these improvements were mainly seen when the initial sample size was relatively low (e.g. a median relative error decrease of 0.04% per sampled parish for sample sizes below 500 parishes). For higher sample sizes, the added value of further increasing the number of samples declined rapidly (e.g. a median relative error decrease of 0.01% per sampled parish for sample sizes above 500 parishes. When a two-stage stratified sample design was applied to yield more evenly distributed samples, accuracy levels were higher for low sample densities and stabilised at lower sample sizes compared to one-stage stratified sampling. Aggregating the resulting cattle number estimates yielded significantly more accurate results because of averaging under- and over-estimates (e.g. when aggregating cattle number estimates from subcounty to district level, P <0.009 based on a sample of 2,077 parishes using one-stage stratified samples). During aggregation, area-weighted mean values were assigned to higher administrative unit levels. However, when this step is preceded by a spatial interpolation to fill in missing values in non-sampled areas, accuracy is improved remarkably. This counts especially for low sample sizes and spatially even distributed samples (e.g. P <0.001 for a sample of 170 parishes using one-stage stratified sampling and aggregation on district level). Whether the same observations apply on a lower spatial scale should be further investigated.

Estimation of infection prevalence and sensitivity in a stratified two-stage sampling design employing highly specific diagnostic tests when there is no gold standard.

PubMed

Miller, Ezer; Huppert, Amit; Novikov, Ilya; Warburg, Alon; Hailu, Asrat; Abbasi, Ibrahim; Freedman, Laurence S

2015-11-10

In this work, we describe a two-stage sampling design to estimate the infection prevalence in a population. In the first stage, an imperfect diagnostic test was performed on a random sample of the population. In the second stage, a different imperfect test was performed in a stratified random sample of the first sample. To estimate infection prevalence, we assumed conditional independence between the diagnostic tests and develop method of moments estimators based on expectations of the proportions of people with positive and negative results on both tests that are functions of the tests' sensitivity, specificity, and the infection prevalence. A closed-form solution of the estimating equations was obtained assuming a specificity of 100% for both tests. We applied our method to estimate the infection prevalence of visceral leishmaniasis according to two quantitative polymerase chain reaction tests performed on blood samples taken from 4756 patients in northern Ethiopia. The sensitivities of the tests were also estimated, as well as the standard errors of all estimates, using a parametric bootstrap. We also examined the impact of departures from our assumptions of 100% specificity and conditional independence on the estimated prevalence. Copyright © 2015 John Wiley & Sons, Ltd.

Joint multiple fully connected convolutional neural network with extreme learning machine for hepatocellular carcinoma nuclei grading.

PubMed

Li, Siqi; Jiang, Huiyan; Pang, Wenbo

2017-05-01

Accurate cell grading of cancerous tissue pathological image is of great importance in medical diagnosis and treatment. This paper proposes a joint multiple fully connected convolutional neural network with extreme learning machine (MFC-CNN-ELM) architecture for hepatocellular carcinoma (HCC) nuclei grading. First, in preprocessing stage, each grayscale image patch with the fixed size is obtained using center-proliferation segmentation (CPS) method and the corresponding labels are marked under the guidance of three pathologists. Next, a multiple fully connected convolutional neural network (MFC-CNN) is designed to extract the multi-form feature vectors of each input image automatically, which considers multi-scale contextual information of deep layer maps sufficiently. After that, a convolutional neural network extreme learning machine (CNN-ELM) model is proposed to grade HCC nuclei. Finally, a back propagation (BP) algorithm, which contains a new up-sample method, is utilized to train MFC-CNN-ELM architecture. The experiment comparison results demonstrate that our proposed MFC-CNN-ELM has superior performance compared with related works for HCC nuclei grading. Meanwhile, external validation using ICPR 2014 HEp-2 cell dataset shows the good generalization of our MFC-CNN-ELM architecture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Configuration of management accounting information system for multi-stage manufacturing

NASA Astrophysics Data System (ADS)

Mkrtychev, S. V.; Ochepovsky, A. V.; Enik, O. A.

2018-05-01

The article presents an approach to configuration of a management accounting information system (MAIS) that provides automated calculations and the registration of normative production losses in multi-stage manufacturing. The use of MAIS with the proposed configuration at the enterprises of textile and woodworking industries made it possible to increase the accuracy of calculations for normative production losses and to organize accounting thereof with the reference to individual stages of the technological process. Thus, high efficiency of multi-stage manufacturing control is achieved.

Selection of adequate site location during early stages of construction project management: A multi-criteria decision analysis approach

NASA Astrophysics Data System (ADS)

Marović, Ivan; Hanak, Tomaš

2017-10-01

In the management of construction projects special attention should be given to the planning as the most important phase of decision-making process. Quality decision-making based on adequate and comprehensive collaboration of all involved stakeholders is crucial in project’s early stages. Fundamental reasons for existence of this problem arise from: specific conditions of construction industry (final products are inseparable from the location i.e. location has a strong influence of building design and its structural characteristics as well as technology which will be used during construction), investors’ desires and attitudes, and influence of socioeconomic and environment aspects. Considering all mentioned reasons one can conclude that selection of adequate construction site location for future investment is complex, low structured and multi-criteria problem. To take into account all the dimensions, the proposed model for selection of adequate site location is devised. The model is based on AHP (for designing the decision-making hierarchy) and PROMETHEE (for pairwise comparison of investment locations) methods. As a result of mixing basis feature of both methods, operational synergies can be achieved in multi-criteria decision analysis. Such gives the decision-maker a sense of assurance, knowing that if the procedure proposed by the presented model has been followed, it will lead to a rational decision, carefully and systematically thought out.

Construction of social value or utility-based health indices: the usefulness of factorial experimental design plans.

PubMed

Cadman, D; Goldsmith, C

1986-01-01

Global indices, which aggregate multiple health or function attributes into a single summary indicator, are useful measures in health research. Two key issues must be addressed in the initial stages of index construction from the universe of possible health and function attributes, which ones should be included in a new index? and how simple can the statistical model be to combine attributes into a single numeric index value? Factorial experimental designs were used in the initial stages of developing a function index for evaluating a program for the care of young handicapped children. Beginning with eight attributes judged important to the goals of the program by clinicians, social preference values for different function states were obtained from 32 parents of handicapped children and 32 members of the community. Using category rating methods each rater scored 16 written multi-attribute case descriptions which contained information about a child's status for all eight attributes. Either a good or poor level of each function attribute and age 3 or 5 years were described in each case. Thus, 2(8) = 256 different cases were rated. Two factorial design plans were selected and used to allocate case descriptions to raters. Analysis of variance determined that seven of the eight clinician selected attributes were required in a social value based index for handicapped children. Most importantly, the subsequent steps of index construction could be greatly simplified by the finding that a simple additive statistical model without complex attribute interaction terms was adequate for the index. We conclude that factorial experimental designs are an efficient, feasible and powerful tool for the initial stages of constructing a multi-attribute health index.

On decoding of multi-level MPSK modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Gupta, Alok Kumar

1990-01-01

The decoding problem of multi-level block modulation codes is investigated. The hardware design of soft-decision Viterbi decoder for some short length 8-PSK block modulation codes is presented. An effective way to reduce the hardware complexity of the decoder by reducing the branch metric and path metric, using a non-uniform floating-point to integer mapping scheme, is proposed and discussed. The simulation results of the design are presented. The multi-stage decoding (MSD) of multi-level modulation codes is also investigated. The cases of soft-decision and hard-decision MSD are considered and their performance are evaluated for several codes of different lengths and different minimum squared Euclidean distances. It is shown that the soft-decision MSD reduces the decoding complexity drastically and it is suboptimum. The hard-decision MSD further simplifies the decoding while still maintaining a reasonable coding gain over the uncoded system, if the component codes are chosen properly. Finally, some basic 3-level 8-PSK modulation codes using BCH codes as component codes are constructed and their coding gains are found for hard decision multistage decoding.

Stackable differential mobility analyzer for aerosol measurement

DOEpatents

Cheng, Meng-Dawn [Oak Ridge, TN; Chen, Da-Ren [Creve Coeur, MO

2007-05-08

A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for charging to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.

Raytheon advanced pulse-tube cryocoolers

NASA Astrophysics Data System (ADS)

Conrad, Ted; Yates, Ryan; Kuo, Daniel; Schaefer, Brian; Arnoult, Matt

2016-05-01

Since the 1970s, Raytheon has developed, built, tested and integrated high performance cryocoolers. Our versatile designs for single and multi-stage cryocoolers provide reliable operation for temperatures from 10 to 200 Kelvin with power levels ranging from 50 W to nearly 600 W. These cryocoolers incorporate clearance seals, flexure suspensions, hermetic housings and dynamic balancing to provide long service life and reliable operation in all relevant environments. Recently, Raytheon has developed an advanced regenerator technology capable of operating efficiently at high frequencies and outperforming traditional screen regenerators. The Raytheon Advanced Miniature (RAM-100) cryocooler, a flight packaged, high frequency, single stage pulse tube cooler with an integrated surge volume and inertance tube, has been designed for use with this regenerator. Design details and experimentally measured performance of two iterations of the RAM cryocooler are presented in this paper.

Control and acquisition systems for new scanning transmission x-ray microscopes at Advanced Light Source (abstract)

NASA Astrophysics Data System (ADS)

Tyliszczak, T.; Hitchcock, P.; Kilcoyne, A. L. D.; Ade, H.; Hitchcock, A. P.; Fakra, S.; Steele, W. F.; Warwick, T.

2002-03-01

Two new scanning x-ray transmission microscopes are being built at beamline 5.3.2 and beamline 7.0 of the Advanced Light Source that have novel aspects in their control and acquisition systems. Both microscopes use multiaxis laser interferometry to improve the precision of pixel location during imaging and energy scans as well as to remove image distortions. Beam line 5.3.2 is a new beam line where the new microscope will be dedicated to studies of polymers in the 250-600 eV energy range. Since this is a bending magnet beam line with lower x-ray brightness than undulator beam lines, special attention is given to the design not only to minimize distortions and vibrations but also to optimize the controls and acquisition to improve data collection efficiency. 5.3.2 microscope control and acquisition is based on a PC computer running WINDOWS 2000. All mechanical stages are moved by stepper motors with rack mounted controllers. A dedicated counter board is used for counting and timing and a multi-input/output board is used for analog acquisition and control of the focusing mirror. A three axis differential laser interferometer is being used to improve stability and precision by careful tracking of the relative positions of the sample and zone plate. Each axis measures the relative distance between a mirror placed on the sample stage and a mirror attached to the zone plate holder. Agilent Technologies HP 10889A servo-axis interferometer boards are used. While they were designed to control servo motors, our tests show that they can be used to directly control the piezo stage. The use of the interferometer servo-axis boards provides excellent point stability for spectral measurements. The interferometric feedback also provides active vibration isolation which reduces deleterious impact of mechanical vibrations up to 20-30 Hz. It also can improve the speed and precision of image scans. Custom C++ software has been written to provide user friendly control of the microscope and integration with visual light microscopy indexing of the samples. The beam line 7.0 microscope upgrade is a new design which will replace the existing microscope. The design is similar to that of beam line 5.3.2, including interferometric position encoding. However the acquisition and control is based on VXI systems, a Sun computer, and LABVIEW™ software. The main objective of the BL 7.0 microscope upgrade is to achieve precise image scans at very high speed (pixel dwells as short as 10 μs) to take full advantage of the high brightness of the 7.0 undulator beamline. Results of tests and a discussion of the benefits of our scanning microscope designs will be presented.

[Advances in studies on multi-stage countercurrent extraction technology in traditional Chinese medicine].

PubMed

Xie, Zhi-Peng; Liu, Xue-Song; Chen, Yong; Cai, Ming; Qu, Hai-Bin; Cheng, Yi-Yu

2007-05-01

Multi-stage countercurrent extraction technology, integrating solvent extraction, repercolation with dynamic and countercurrent extraction, is a novel extraction technology for the traditional Chinese medicine. This solvent-saving, energy-saving and high-extraction-efficiency technology can at the most drive active compounds to diffuse from the herbal materials into the solvent stage by stage by creating concentration differences between the herbal materials and the solvents. This paper reviewed the basic principle, the influence factors and the research progress and trends of the equipments and the application of the multi-stage countercurrent extraction.

Application of the theory of reasoned action to promoting breakfast consumption.

PubMed

Hosseini, Zahra; Gharlipour Gharghani, Zabihollah; Mansoori, Anahita; Aghamolaei, Teamur; Mohammadi Nasrabadi, Maryam

2015-01-01

Breakfast is the most important daily meal, but neglected more than other meals by children and adolescents. The aim of this study was to evaluate the effectiveness of an educational intervention, based on the Theory of Reasoned Action (TRA) to increase breakfast consumption among school children in Bandar Abbas, Iran. In this quasi experimental study which was conducted in 2012, 88 students of four secondary schools in Bandar Abbas, south of Iran, were enrolled. Multi-stage cluster sampling was performed with random allocation of interventional and control groups. The study tool was a questionnaire which was filled by the students before and two months after the educational intervention. For data analysis, statistical tests including paired-samples t-test, independent samples t-test, Wilcoxon test, and Mann-Whitney test were used through SPSS v.18 software. The result of the study showed that application of TRA significantly increased scores of behavior of breakfast consumption (p<0.01). After the intervention, a significant increase was revealed in all nutrition intakes, except for fat and sugar (p<0.01). The findings support application of the TRA in improving the intention and behavior of breakfast consumption. Applying this theory for designing interventions to increase breakfast eating is recommended.

Recommendations for choosing an analysis method that controls Type I error for unbalanced cluster sample designs with Gaussian outcomes.

PubMed

Johnson, Jacqueline L; Kreidler, Sarah M; Catellier, Diane J; Murray, David M; Muller, Keith E; Glueck, Deborah H

2015-11-30

We used theoretical and simulation-based approaches to study Type I error rates for one-stage and two-stage analytic methods for cluster-randomized designs. The one-stage approach uses the observed data as outcomes and accounts for within-cluster correlation using a general linear mixed model. The two-stage model uses the cluster specific means as the outcomes in a general linear univariate model. We demonstrate analytically that both one-stage and two-stage models achieve exact Type I error rates when cluster sizes are equal. With unbalanced data, an exact size α test does not exist, and Type I error inflation may occur. Via simulation, we compare the Type I error rates for four one-stage and six two-stage hypothesis testing approaches for unbalanced data. With unbalanced data, the two-stage model, weighted by the inverse of the estimated theoretical variance of the cluster means, and with variance constrained to be positive, provided the best Type I error control for studies having at least six clusters per arm. The one-stage model with Kenward-Roger degrees of freedom and unconstrained variance performed well for studies having at least 14 clusters per arm. The popular analytic method of using a one-stage model with denominator degrees of freedom appropriate for balanced data performed poorly for small sample sizes and low intracluster correlation. Because small sample sizes and low intracluster correlation are common features of cluster-randomized trials, the Kenward-Roger method is the preferred one-stage approach. Copyright © 2015 John Wiley & Sons, Ltd.

3D Printer Generated Tissue iMolds for Cleared Tissue Using Single- and Multi-Photon Microscopy for Deep Tissue Evaluation.

PubMed

Miller, Sean J; Rothstein, Jeffrey D

2017-01-01

Pathological analyses and methodology has recently undergone a dramatic revolution. With the creation of tissue clearing methods such as CLARITY and CUBIC, groups can now achieve complete transparency in tissue samples in nano-porous hydrogels. Cleared tissue is then imagined in a semi-aqueous medium that matches the refractive index of the objective being used. However, one major challenge is the ability to control tissue movement during imaging and to relocate precise locations post sequential clearing and re-staining. Using 3D printers, we designed tissue molds that fit precisely around the specimen being imaged. First, images are taken of the specimen, followed by importing and design of a structural mold, then printed with affordable plastics by a 3D printer. With our novel design, we have innovated tissue molds called innovative molds (iMolds) that can be generated in any laboratory and are customized for any organ, tissue, or bone matter being imaged. Furthermore, the inexpensive and reusable tissue molds are made compatible for any microscope such as single and multi-photon confocal with varying stage dimensions. Excitingly, iMolds can also be generated to hold multiple organs in one mold, making reconstruction and imaging much easier. Taken together, with iMolds it is now possible to image cleared tissue in clearing medium while limiting movement and being able to relocate precise anatomical and cellular locations on sequential imaging events in any basic laboratory. This system provides great potential for screening widespread effects of therapeutics and disease across entire organ systems.

Development of JSTAMP-Works/NV and HYSTAMP for Multipurpose Multistage Sheet Metal Forming Simulation

NASA Astrophysics Data System (ADS)

Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu

2005-08-01

Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, "faster, more accurate and easier", of process designers and CAE engineers, a new metal forming simulation system JSTAMP-Works/NV is developed. The JSTAMP-Works/NV packaged the automatic healing function of CAD and had much more new capabilities such as prediction of 3D trimming lines for flanging or hemming, remote control of solver execution for multi-stage forming processes and shape evaluation between FEM and CAD. On the other way, a multi-stage multi-purpose inverse FEM solver HYSTAMP is developed and will be soon put into market, which is approved to be very fast, quite accurate and robust. Lastly, authors will give some application examples of user defined ductile damage subroutine in LS-DYNA for the estimation of material failure and springback in metal forming simulation.

Reproducibility of preclinical animal research improves with heterogeneity of study samples

PubMed Central

Vogt, Lucile; Sena, Emily S.; Würbel, Hanno

2018-01-01

Single-laboratory studies conducted under highly standardized conditions are the gold standard in preclinical animal research. Using simulations based on 440 preclinical studies across 13 different interventions in animal models of stroke, myocardial infarction, and breast cancer, we compared the accuracy of effect size estimates between single-laboratory and multi-laboratory study designs. Single-laboratory studies generally failed to predict effect size accurately, and larger sample sizes rendered effect size estimates even less accurate. By contrast, multi-laboratory designs including as few as 2 to 4 laboratories increased coverage probability by up to 42 percentage points without a need for larger sample sizes. These findings demonstrate that within-study standardization is a major cause of poor reproducibility. More representative study samples are required to improve the external validity and reproducibility of preclinical animal research and to prevent wasting animals and resources for inconclusive research. PMID:29470495

Estimation of Supersonic Stage Separation Aerodynamics of Winged-Body Launch Vehicles Using Response Surface Methods

NASA Technical Reports Server (NTRS)

Erickson, Gary E.

2010-01-01

Response surface methodology was used to estimate the longitudinal stage separation aerodynamic characteristics of a generic, bimese, winged multi-stage launch vehicle configuration at supersonic speeds in the NASA LaRC Unitary Plan Wind Tunnel. The Mach 3 staging was dominated by shock wave interactions between the orbiter and booster vehicles throughout the relative spatial locations of interest. The inference space was partitioned into several contiguous regions within which the separation aerodynamics were presumed to be well-behaved and estimable using central composite designs capable of fitting full second-order response functions. The underlying aerodynamic response surfaces of the booster vehicle in belly-to-belly proximity to the orbiter vehicle were estimated using piecewise-continuous lower-order polynomial functions. The quality of fit and prediction capabilities of the empirical models were assessed in detail, and the issue of subspace boundary discontinuities was addressed. Augmenting the central composite designs to full third-order using computer-generated D-optimality criteria was evaluated. The usefulness of central composite designs, the subspace sizing, and the practicality of fitting lower-order response functions over a partitioned inference space dominated by highly nonlinear and possibly discontinuous shock-induced aerodynamics are discussed.

Collective Research Projects in the History of Mathematics Classroom

ERIC Educational Resources Information Center

Despeaux, Sloan Evans

2014-01-01

In this article, I will discuss a collective research project that I designed for my History of Mathematics course. My students, who are by and large pre-service teachers, explored online, digital versions of 18th-century British almanacs that contained question-and-answer sections for mathematics. In a multi-stage research process, they explored…

A dynamic multi-scale Markov model based methodology for remaining life prediction

NASA Astrophysics Data System (ADS)

Yan, Jihong; Guo, Chaozhong; Wang, Xing

2011-05-01

The ability to accurately predict the remaining life of partially degraded components is crucial in prognostics. In this paper, a performance degradation index is designed using multi-feature fusion techniques to represent deterioration severities of facilities. Based on this indicator, an improved Markov model is proposed for remaining life prediction. Fuzzy C-Means (FCM) algorithm is employed to perform state division for Markov model in order to avoid the uncertainty of state division caused by the hard division approach. Considering the influence of both historical and real time data, a dynamic prediction method is introduced into Markov model by a weighted coefficient. Multi-scale theory is employed to solve the state division problem of multi-sample prediction. Consequently, a dynamic multi-scale Markov model is constructed. An experiment is designed based on a Bently-RK4 rotor testbed to validate the dynamic multi-scale Markov model, experimental results illustrate the effectiveness of the methodology.

Effects of Early and Later Family Violence on Children's Behavior Problems and Depression: A Longitudinal, Multi-Informant Perspective

ERIC Educational Resources Information Center

Sternberg, Kathleen J.; Lamb, Michael E.; Guterman, Eva; Abbott, Craig B.

2006-01-01

Objectives: To examine the effects of different forms of family violence at two developmental stages by assessing a sample of 110 Israeli children, drawn from the case files of Israeli family service agencies, studied longitudinally in both middle childhood and adolescence. Methods: Information about the children's adjustment was obtained from…

The Effect of School Bureaucracy on the Relationship between Principals' Leadership Practices and Teacher Commitment in Malaysia Secondary Schools

ERIC Educational Resources Information Center

Kean, Teoh Hong; Kannan, Sathiamoorthy; Piaw, Chua Yan

2017-01-01

The main aim of this research paper was to ascertain the relationship between principal leadership practices and teacher commitment. The study was conducted using quantitative survey questionnaire to 384 secondary school teachers, ranging from band 1 to band 6 in Malaysia using multi stage stratified cluster random sampling. This study was using…

Entrepreneurship Education in Delta State Tertiary Institution as a Means of Achieving National Growth and Development

ERIC Educational Resources Information Center

Osakwe, Regina N.

2015-01-01

This study examined entrepreneurship education in Delta Sate tertiary institutions as a means of national growth and development. Two research questions were asked to guide the study. The population comprised all the 1,898 academic staff in eight tertiary institutions in the state. A sample of 800 lecturers was drawn through the multi stage and…

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

ERIC Educational Resources Information Center

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

2012-01-01

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

Effect of multi-stage inoculation on the bacterial and fungal community structure during organic municipal solid wastes composting.

PubMed

Xi, Beidou; He, Xiaosong; Dang, Qiuling; Yang, Tianxue; Li, Mingxiao; Wang, Xiaowei; Li, Dan; Tang, Jun

2015-11-01

In this study, PCR-DGGE method was applied to investigate the impact of multi-stage inoculation treatment on the community composition of bacterial and fungal during municipal solid wastes (MSW) composting process. The results showed that the high temperature period was extended by the multi-stage inoculation treatment, 1day longer than initial-stage inoculation treatment, and 5days longer than non-inoculation treatment. The temperature of the secondary fermentation increased to 51°C with multi-stage inoculation treatment. The multi-stage inoculation method improved the community diversity of bacteria and fungi that the diversity indexes reached the maximum on the 17days and 20days respectively, avoided the competition between inoculations and indigenous microbes, and enhanced the growth of dominant microorganisms. The DNA sequence indicated that various kinds of uncultured microorganisms with determined ratios were detected, which were dominant microbes during the whole fermentation process. These findings call for further researches of compost microbial cultivation technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydraulic design to optimize the treatment capacity of Multi-Stage Filtration units

NASA Astrophysics Data System (ADS)

Mushila, C. N.; Ochieng, G. M.; Otieno, F. A. O.; Shitote, S. M.; Sitters, C. W.

2016-04-01

Multi-Stage Filtration (MSF) can provide a robust treatment alternative for surface water sources of variable water quality in rural communities at low operation and maintenance costs. MSF is a combination of Slow Sand Filters (SSFs) and Pre-treatment systems. The general objective of this research was to optimize the treatment capacity of MSF. A pilot plant study was undertaken to meet this objective. The pilot plant was monitored for a continuous 98 days from commissioning till the end of the project. Three main stages of MSF namely: The Dynamic Gravel Filter (DGF), Horizontal-flow Roughing Filter (HRF) and SSF were identified, designed and built. The response of the respective MSF units in removal of selected parameters guiding drinking water quality such as microbiological (Faecal and Total coliform), Suspended Solids, Turbidity, PH, Temperature, Iron and Manganese was investigated. The benchmark was the Kenya Bureau (KEBS) and World Health Organization (WHO) Standards for drinking water quality. With respect to microbiological raw water quality improvement, MSF units achieved on average 98% Faecal and 96% Total coliform removal. Results obtained indicate that implementation of MSF in rural communities has the potential to increase access to portable water to the rural populace with a probable consequent decrease in waterborne diseases. With a reduced down time due to illness, more time would be spent in undertaking other economic activities.

Surgical outcomes of robot-assisted rectal cancer surgery using the da Vinci Surgical System: a multi-center pilot Phase II study.

PubMed

Tsukamoto, Shunsuke; Nishizawa, Yuji; Ochiai, Hiroki; Tsukada, Yuichiro; Sasaki, Takeshi; Shida, Dai; Ito, Masaaki; Kanemitsu, Yukihide

2017-12-01

We conducted a multi-center pilot Phase II study to examine the safety of robotic rectal cancer surgery performed using the da Vinci Surgical System during the introduction period of robotic rectal surgery at two institutes based on surgical outcomes. This study was conducted with a prospective, multi-center, single-arm, open-label design to assess the safety and feasibility of robotic surgery for rectal cancer (da Vinci Surgical System). The primary endpoint was the rate of adverse events during and after robotic surgery. The secondary endpoint was the completion rate of robotic surgery. Between April 2014 and July 2016, 50 patients were enrolled in this study. Of these, 10 (20%) had rectosigmoid cancer, 17 (34%) had upper rectal cancer, and 23 (46%) had lower rectal cancer; six underwent high anterior resection, 32 underwent low anterior resection, 11 underwent intersphincteric resection, and one underwent abdominoperineal resection. Pathological stages were Stage 0 in 1 patient, Stage I in 28 patients, Stage II in 7 patients and Stage III in 14 patients. Pathologically complete resection was achieved in all patients. There was no intraoperative organ damage or postoperative mortality. Eight (16%) patients developed complications of all grades, of which 2 (4%) were Grade 3 or higher, including anastomotic leakage (2%) and conversion to open surgery (2%). The present study demonstrates the feasibility and safety of robotic rectal cancer surgery, as reflected by low morbidity and low conversion rates, during the introduction period. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Multi-objective robust design of energy-absorbing components using coupled process-performance simulations

NASA Astrophysics Data System (ADS)

Najafi, Ali; Acar, Erdem; Rais-Rohani, Masoud

2014-02-01

The stochastic uncertainties associated with the material, process and product are represented and propagated to process and performance responses. A finite element-based sequential coupled process-performance framework is used to simulate the forming and energy absorption responses of a thin-walled tube in a manner that both material properties and component geometry can evolve from one stage to the next for better prediction of the structural performance measures. Metamodelling techniques are used to develop surrogate models for manufacturing and performance responses. One set of metamodels relates the responses to the random variables whereas the other relates the mean and standard deviation of the responses to the selected design variables. A multi-objective robust design optimization problem is formulated and solved to illustrate the methodology and the influence of uncertainties on manufacturability and energy absorption of a metallic double-hat tube. The results are compared with those of deterministic and augmented robust optimization problems.

Optimization of Adaboost Algorithm for Sonar Target Detection in a Multi-Stage ATR System

NASA Technical Reports Server (NTRS)

Lin, Tsung Han (Hank)

2011-01-01

JPL has developed a multi-stage Automated Target Recognition (ATR) system to locate objects in images. First, input images are preprocessed and sent to a Grayscale Optical Correlator (GOC) filter to identify possible regions-of-interest (ROIs). Second, feature extraction operations are performed using Texton filters and Principal Component Analysis (PCA). Finally, the features are fed to a classifier, to identify ROIs that contain the targets. Previous work used the Feed-forward Back-propagation Neural Network for classification. In this project we investigate a version of Adaboost as a classifier for comparison. The version we used is known as GentleBoost. We used the boosted decision tree as the weak classifier. We have tested our ATR system against real-world sonar images using the Adaboost approach. Results indicate an improvement in performance over a single Neural Network design.

Evaluation method of membrane performance in membrane distillation process for seawater desalination.

PubMed

Chung, Seungjoon; Seo, Chang Duck; Choi, Jae-Hoon; Chung, Jinwook

2014-01-01

Membrane distillation (MD) is an emerging desalination technology as an energy-saving alternative to conventional distillation and reverse osmosis method. The selection of appropriate membrane is a prerequisite for the design of an optimized MD process. We proposed a simple approximation method to evaluate the performance of membranes for MD process. Three hollow fibre-type commercial membranes with different thicknesses and pore sizes were tested. Experimental results showed that one membrane was advantageous due to the highest flux, whereas another membrane was due to the lowest feed temperature drop. Regression analyses and multi-stage calculations were used to account for the trade-offeffects of flux and feed temperature drop. The most desirable membrane was selected from tested membranes in terms of the mean flux in a multi-stage process. This method would be useful for the selection of the membranes without complicated simulation techniques.

Analysis of fatigue reliability for high temperature and high pressure multi-stage decompression control valve

NASA Astrophysics Data System (ADS)

Yu, Long; Xu, Juanjuan; Zhang, Lifang; Xu, Xiaogang

2018-03-01

Based on stress-strength interference theory to establish the reliability mathematical model for high temperature and high pressure multi-stage decompression control valve (HMDCV), and introduced to the temperature correction coefficient for revising material fatigue limit at high temperature. Reliability of key dangerous components and fatigue sensitivity curve of each component are calculated and analyzed by the means, which are analyzed the fatigue life of control valve and combined with reliability theory of control valve model. The impact proportion of each component on the control valve system fatigue failure was obtained. The results is shown that temperature correction factor makes the theoretical calculations of reliability more accurate, prediction life expectancy of main pressure parts accords with the technical requirements, and valve body and the sleeve have obvious influence on control system reliability, the stress concentration in key part of control valve can be reduced in the design process by improving structure.

The Emergent Capabilities of Distributed Satellites and Methods for Selecting Distributed Satellite Science Missions

NASA Astrophysics Data System (ADS)

Corbin, B. A.; Seager, S.; Ross, A.; Hoffman, J.

2017-12-01

Distributed satellite systems (DSS) have emerged as an effective and cheap way to conduct space science, thanks to advances in the small satellite industry. However, relatively few space science missions have utilized multiple assets to achieve their primary scientific goals. Previous research on methods for evaluating mission concepts designs have shown that distributed systems are rarely competitive with monolithic systems, partially because it is difficult to quantify the added value of DSSs over monolithic systems. Comparatively little research has focused on how DSSs can be used to achieve new, fundamental space science goals that cannot be achieved with monolithic systems or how to choose a design from a larger possible tradespace of options. There are seven emergent capabilities of distributed satellites: shared sampling, simultaneous sampling, self-sampling, census sampling, stacked sampling, staged sampling, and sacrifice sampling. These capabilities are either fundamentally, analytically, or operationally unique in their application to distributed science missions, and they can be leveraged to achieve science goals that are either impossible or difficult and costly to achieve with monolithic systems. The Responsive Systems Comparison (RSC) method combines Multi-Attribute Tradespace Exploration with Epoch-Era Analysis to examine benefits, costs, and flexible options in complex systems over the mission lifecycle. Modifications to the RSC method as it exists in previously published literature were made in order to more accurately characterize how value is derived from space science missions. New metrics help rank designs by the value derived over their entire mission lifecycle and show more accurate cumulative value distributions. The RSC method was applied to four case study science missions that leveraged the emergent capabilities of distributed satellites to achieve their primary science goals. In all four case studies, RSC showed how scientific value was gained that would be impossible or unsatisfactory with monolithic systems and how changes in design and context variables affected the overall mission value. Each study serves as a blueprint for how to conduct a Pre-Phase A study using these methods to learn more about the tradespace of a particular mission.

A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

ERIC Educational Resources Information Center

Luong, Ming; Stevens, Jeff

2015-01-01

The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

Social networks and health-related quality of life: a population based study among older adults.

PubMed

Gallegos-Carrillo, Katia; Mudgal, Jyoti; Sánchez-García, Sergio; Wagner, Fernando A; Gallo, Joseph J; Salmerón, Jorge; García-Peña, Carmen

2009-01-01

To examine the relationship between components of social networks and health-related quality of life (HRQL) in older adults with and without depressive symptoms. Comparative cross-sectional study with data from the cohort study 'Integral Study of Depression', carried out in Mexico City during 2004. The sample was selected through a multi-stage probability design. HRQL was measured with the SF-36. Geriatric Depression Scale (GDS) and the Short Anxiety Screening Test (SAST) determined depressive symptoms and anxiety. T-test and multiple linear regressions were conducted. Older adults with depressive symptoms had the lowest scores in all HRQL scales. A larger network of close relatives and friends was associated with better HRQL on several scales. Living alone did not significantly affect HRQL level, in either the study or comparison group. A positive association between some components of social networks and good HRQL exists even in older adults with depressive symptoms.

The Role of Hopelessness in the Health of Low-Class Rural Chinese Residents.

PubMed

Zhang, Huiping; Wu, Lei; Cheng, Mingming

2018-03-12

It is well known that health inequality has been happening between rural and urban Chinese populations, however, the health differences among rural Chinese residents remain unclear. This study aims to assess the physical and mental health of rural Chinese residents in different social classes, and then to examine the mediating role of hopelessness between social class and health-related quality of life (HRQOL). A stratified multi-stage sampling was used to recruit 2003 rural residents responding to the 12-item Short Form Health Survey (SF-12). The results showed that lower-class rural Chinese residents reported lower physical and mental health as well as a higher level of hopelessness. Furthermore, hopelessness could fully mediate the association between social class and physical and mental health. These findings will generate significant implications for identifying those at particular risk for lower quality of life and designing social work intervention programs in rural China's context.

Epoch-based Entropy for Early Screening of Alzheimer's Disease.

PubMed

Houmani, N; Dreyfus, G; Vialatte, F B

2015-12-01

In this paper, we introduce a novel entropy measure, termed epoch-based entropy. This measure quantifies disorder of EEG signals both at the time level and spatial level, using local density estimation by a Hidden Markov Model on inter-channel stationary epochs. The investigation is led on a multi-centric EEG database recorded from patients at an early stage of Alzheimer's disease (AD) and age-matched healthy subjects. We investigate the classification performances of this method, its robustness to noise, and its sensitivity to sampling frequency and to variations of hyperparameters. The measure is compared to two alternative complexity measures, Shannon's entropy and correlation dimension. The classification accuracies for the discrimination of AD patients from healthy subjects were estimated using a linear classifier designed on a development dataset, and subsequently tested on an independent test set. Epoch-based entropy reached a classification accuracy of 83% on the test dataset (specificity = 83.3%, sensitivity = 82.3%), outperforming the two other complexity measures. Furthermore, it was shown to be more stable to hyperparameter variations, and less sensitive to noise and sampling frequency disturbances than the other two complexity measures.

Nuclear Engine System Simulation (NESS). Volume 1: Program user's guide

NASA Astrophysics Data System (ADS)

Pelaccio, Dennis G.; Scheil, Christine M.; Petrosky, Lyman J.

1993-03-01

A Nuclear Thermal Propulsion (NTP) engine system design analysis tool is required to support current and future Space Exploration Initiative (SEI) propulsion and vehicle design studies. Currently available NTP engine design models are those developed during the NERVA program in the 1960's and early 1970's and are highly unique to that design or are modifications of current liquid propulsion system design models. To date, NTP engine-based liquid design models lack integrated design of key NTP engine design features in the areas of reactor, shielding, multi-propellant capability, and multi-redundant pump feed fuel systems. Additionally, since the SEI effort is in the initial development stage, a robust, verified NTP analysis design tool could be of great use to the community. This effort developed an NTP engine system design analysis program (tool), known as the Nuclear Engine System Simulation (NESS) program, to support ongoing and future engine system and stage design study efforts. In this effort, Science Applications International Corporation's (SAIC) NTP version of the Expanded Liquid Engine Simulation (ELES) program was modified extensively to include Westinghouse Electric Corporation's near-term solid-core reactor design model. The ELES program has extensive capability to conduct preliminary system design analysis of liquid rocket systems and vehicles. The program is modular in nature and is versatile in terms of modeling state-of-the-art component and system options as discussed. The Westinghouse reactor design model, which was integrated in the NESS program, is based on the near-term solid-core ENABLER NTP reactor design concept. This program is now capable of accurately modeling (characterizing) a complete near-term solid-core NTP engine system in great detail, for a number of design options, in an efficient manner. The following discussion summarizes the overall analysis methodology, key assumptions, and capabilities associated with the NESS presents an example problem, and compares the results to related NTP engine system designs. Initial installation instructions and program disks are in Volume 2 of the NESS Program User's Guide.

Nuclear Engine System Simulation (NESS). Volume 1: Program user's guide

NASA Technical Reports Server (NTRS)

Pelaccio, Dennis G.; Scheil, Christine M.; Petrosky, Lyman J.

1993-01-01

A Nuclear Thermal Propulsion (NTP) engine system design analysis tool is required to support current and future Space Exploration Initiative (SEI) propulsion and vehicle design studies. Currently available NTP engine design models are those developed during the NERVA program in the 1960's and early 1970's and are highly unique to that design or are modifications of current liquid propulsion system design models. To date, NTP engine-based liquid design models lack integrated design of key NTP engine design features in the areas of reactor, shielding, multi-propellant capability, and multi-redundant pump feed fuel systems. Additionally, since the SEI effort is in the initial development stage, a robust, verified NTP analysis design tool could be of great use to the community. This effort developed an NTP engine system design analysis program (tool), known as the Nuclear Engine System Simulation (NESS) program, to support ongoing and future engine system and stage design study efforts. In this effort, Science Applications International Corporation's (SAIC) NTP version of the Expanded Liquid Engine Simulation (ELES) program was modified extensively to include Westinghouse Electric Corporation's near-term solid-core reactor design model. The ELES program has extensive capability to conduct preliminary system design analysis of liquid rocket systems and vehicles. The program is modular in nature and is versatile in terms of modeling state-of-the-art component and system options as discussed. The Westinghouse reactor design model, which was integrated in the NESS program, is based on the near-term solid-core ENABLER NTP reactor design concept. This program is now capable of accurately modeling (characterizing) a complete near-term solid-core NTP engine system in great detail, for a number of design options, in an efficient manner. The following discussion summarizes the overall analysis methodology, key assumptions, and capabilities associated with the NESS presents an example problem, and compares the results to related NTP engine system designs. Initial installation instructions and program disks are in Volume 2 of the NESS Program User's Guide.

Computational design of protein antigens that interact with the CDR H3 loop of HIV broadly neutralizing antibody 2F5.

PubMed

Azoitei, M L; Ban, Y A; Kalyuzhny, O; Guenaga, J; Schroeter, A; Porter, J; Wyatt, R; Schief, William R

2014-10-01

Rational design of proteins with novel binding specificities and increased affinity is one of the major goals of computational protein design. Epitope-scaffolds are a new class of antigens engineered by transplanting viral epitopes of predefined structure to protein scaffolds, or by building protein scaffolds around such epitopes. Epitope-scaffolds are of interest as vaccine components to attempt to elicit neutralizing antibodies targeting the specified epitope. In this study we developed a new computational protocol, MultiGraft Interface, that transplants epitopes but also designs additional scaffold features outside the epitope to enhance antibody-binding specificity and potentially influence the specificity of elicited antibodies. We employed MultiGraft Interface to engineer novel epitope-scaffolds that display the known epitope of human immunodeficiency virus 1 (HIV-1) neutralizing antibody 2F5 and that also interact with the functionally important CDR H3 antibody loop. MultiGraft Interface generated an epitope-scaffold that bound 2F5 with subnanomolar affinity (K(D) = 400 pM) and that interacted with the antibody CDR H3 loop through computationally designed contacts. Substantial structural modifications were necessary to engineer this antigen, with the 2F5 epitope replacing a helix in the native scaffold and with 15% of the native scaffold sequence being modified in the design stage. This epitope-scaffold represents a successful example of rational protein backbone engineering and protein-protein interface design and could prove useful in the field of HIV vaccine design. MultiGraft Interface can be generally applied to engineer novel binding partners with altered specificity and optimized affinity. © 2014 Wiley Periodicals, Inc.

Three essays on multi-level optimization models and applications

NASA Astrophysics Data System (ADS)

Rahdar, Mohammad

The general form of a multi-level mathematical programming problem is a set of nested optimization problems, in which each level controls a series of decision variables independently. However, the value of decision variables may also impact the objective function of other levels. A two-level model is called a bilevel model and can be considered as a Stackelberg game with a leader and a follower. The leader anticipates the response of the follower and optimizes its objective function, and then the follower reacts to the leader's action. The multi-level decision-making model has many real-world applications such as government decisions, energy policies, market economy, network design, etc. However, there is a lack of capable algorithms to solve medium and large scale these types of problems. The dissertation is devoted to both theoretical research and applications of multi-level mathematical programming models, which consists of three parts, each in a paper format. The first part studies the renewable energy portfolio under two major renewable energy policies. The potential competition for biomass for the growth of the renewable energy portfolio in the United States and other interactions between two policies over the next twenty years are investigated. This problem mainly has two levels of decision makers: the government/policy makers and biofuel producers/electricity generators/farmers. We focus on the lower-level problem to predict the amount of capacity expansions, fuel production, and power generation. In the second part, we address uncertainty over demand and lead time in a multi-stage mathematical programming problem. We propose a two-stage tri-level optimization model in the concept of rolling horizon approach to reducing the dimensionality of the multi-stage problem. In the third part of the dissertation, we introduce a new branch and bound algorithm to solve bilevel linear programming problems. The total time is reduced by solving a smaller relaxation problem in each node and decreasing the number of iterations. Computational experiments show that the proposed algorithm is faster than the existing ones.

Adaptation of Decoy Fusion Strategy for Existing Multi-Stage Search Workflows

NASA Astrophysics Data System (ADS)

Ivanov, Mark V.; Levitsky, Lev I.; Gorshkov, Mikhail V.

2016-09-01

A number of proteomic database search engines implement multi-stage strategies aiming at increasing the sensitivity of proteome analysis. These approaches often employ a subset of the original database for the secondary stage of analysis. However, if target-decoy approach (TDA) is used for false discovery rate (FDR) estimation, the multi-stage strategies may violate the underlying assumption of TDA that false matches are distributed uniformly across the target and decoy databases. This violation occurs if the numbers of target and decoy proteins selected for the second search are not equal. Here, we propose a method of decoy database generation based on the previously reported decoy fusion strategy. This method allows unbiased TDA-based FDR estimation in multi-stage searches and can be easily integrated into existing workflows utilizing popular search engines and post-search algorithms.

Modular neural networks: a survey.

PubMed

Auda, G; Kamel, M

1999-04-01

Modular Neural Networks (MNNs) is a rapidly growing field in artificial Neural Networks (NNs) research. This paper surveys the different motivations for creating MNNs: biological, psychological, hardware, and computational. Then, the general stages of MNN design are outlined and surveyed as well, viz., task decomposition techniques, learning schemes and multi-module decision-making strategies. Advantages and disadvantages of the surveyed methods are pointed out, and an assessment with respect to practical potential is provided. Finally, some general recommendations for future designs are presented.

Design of penicillin fermentation process simulation system

NASA Astrophysics Data System (ADS)

Qi, Xiaoyu; Yuan, Zhonghu; Qi, Xiaoxuan; Zhang, Wenqi

2011-10-01

Real-time monitoring for batch process attracts increasing attention. It can ensure safety and provide products with consistent quality. The design of simulation system of batch process fault diagnosis is of great significance. In this paper, penicillin fermentation, a typical non-linear, dynamic, multi-stage batch production process, is taken as the research object. A visual human-machine interactive simulation software system based on Windows operation system is developed. The simulation system can provide an effective platform for the research of batch process fault diagnosis.

DiPOLE: a scalable laser architecture for pumping multi-Hz PW systems

NASA Astrophysics Data System (ADS)

Ertel, Klaus; Banerjee, Saumyabrata; Mason, Paul D.; Phillips, P. Jonathan; Greenhalgh, R. Justin S.; Hernandez-Gomez, Cristina; Collier, John L.

2013-05-01

DiPOLE is a concept for a large aperture gas-cooled cryogenic multislab DPSSL amplifier based on ceramic Yb:YAG. It is designed to amplify ns-pulses at multi-Hz repetition rates and is scalable up the kJ-level. The concept was first tested on a small scale prototype which has so far produced 7.4 J at 10 Hz, with the aim of reaching 10 J at an optical-to-optical efficiency of 25 %. The design of an additional amplifier stage producing 100 J at 10 Hz is underway. When used to pump short-pulse Ti:S or OPCPA systems, PW peak power levels can be produced at repetition rates and efficiencies that lie orders of magnitude above what is achievable today.

Automatic Polyp Detection via A Novel Unified Bottom-up and Top-down Saliency Approach.

PubMed

Yuan, Yixuan; Li, Dengwang; Meng, Max Q-H

2017-07-31

In this paper, we propose a novel automatic computer-aided method to detect polyps for colonoscopy videos. To find the perceptually and semantically meaningful salient polyp regions, we first segment images into multilevel superpixels. Each level corresponds to different sizes of superpixels. Rather than adopting hand-designed features to describe these superpixels in images, we employ sparse autoencoder (SAE) to learn discriminative features in an unsupervised way. Then a novel unified bottom-up and top-down saliency method is proposed to detect polyps. In the first stage, we propose a weak bottom-up (WBU) saliency map by fusing the contrast based saliency and object-center based saliency together. The contrast based saliency map highlights image parts that show different appearances compared with surrounding areas while the object-center based saliency map emphasizes the center of the salient object. In the second stage, a strong classifier with Multiple Kernel Boosting (MKB) is learned to calculate the strong top-down (STD) saliency map based on samples directly from the obtained multi-level WBU saliency maps. We finally integrate these two stage saliency maps from all levels together to highlight polyps. Experiment results achieve 0.818 recall for saliency calculation, validating the effectiveness of our method. Extensive experiments on public polyp datasets demonstrate that the proposed saliency algorithm performs favorably against state-of-the-art saliency methods to detect polyps.

Rule-Mining for the Early Prediction of Chronic Kidney Disease Based on Metabolomics and Multi-Source Data

PubMed Central

Luck, Margaux; Bertho, Gildas; Bateson, Mathilde; Karras, Alexandre; Yartseva, Anastasia; Thervet, Eric

2016-01-01

1H Nuclear Magnetic Resonance (NMR)-based metabolic profiling is very promising for the diagnostic of the stages of chronic kidney disease (CKD). Because of the high dimension of NMR spectra datasets and the complex mixture of metabolites in biological samples, the identification of discriminant biomarkers of a disease is challenging. None of the widely used chemometric methods in NMR metabolomics performs a local exhaustive exploration of the data. We developed a descriptive and easily understandable approach that searches for discriminant local phenomena using an original exhaustive rule-mining algorithm in order to predict two groups of patients: 1) patients having low to mild CKD stages with no renal failure and 2) patients having moderate to established CKD stages with renal failure. Our predictive algorithm explores the m-dimensional variable space to capture the local overdensities of the two groups of patients under the form of easily interpretable rules. Afterwards, a L2-penalized logistic regression on the discriminant rules was used to build predictive models of the CKD stages. We explored a complex multi-source dataset that included the clinical, demographic, clinical chemistry, renal pathology and urine metabolomic data of a cohort of 110 patients. Given this multi-source dataset and the complex nature of metabolomic data, we analyzed 1- and 2-dimensional rules in order to integrate the information carried by the interactions between the variables. The results indicated that our local algorithm is a valuable analytical method for the precise characterization of multivariate CKD stage profiles and as efficient as the classical global model using chi2 variable section with an approximately 70% of good classification level. The resulting predictive models predominantly identify urinary metabolites (such as 3-hydroxyisovalerate, carnitine, citrate, dimethylsulfone, creatinine and N-methylnicotinamide) as relevant variables indicating that CKD significantly affects the urinary metabolome. In addition, the simple knowledge of the concentration of urinary metabolites classifies the CKD stage of the patients correctly. PMID:27861591

The complexity of personality: advantages of a genetically sensitive multi-group design.

PubMed

Hahn, Elisabeth; Spinath, Frank M; Siedler, Thomas; Wagner, Gert G; Schupp, Jürgen; Kandler, Christian

2012-03-01

Findings from many behavioral genetic studies utilizing the classical twin design suggest that genetic and non-shared environmental effects play a significant role in human personality traits. This study focuses on the methodological advantages of extending the sampling frame to include multiple dyads of relatives. We investigated the sensitivity of heritability estimates to the inclusion of sibling pairs, mother-child pairs and grandparent-grandchild pairs from the German Socio-Economic Panel Study in addition to a classical German twin sample consisting of monozygotic- and dizygotic twins. The resulting dataset contained 1.308 pairs, including 202 monozygotic and 147 dizygotic twin pairs, along with 419 sibling pairs, 438 mother-child dyads, and 102 grandparent-child dyads. This genetically sensitive multi-group design allowed the simultaneous testing of additive and non-additive genetic, common and specific environmental effects, including cultural transmission and twin-specific environmental influences. Using manifest and latent modeling of phenotypes (i.e., controlling for measurement error), we compare results from the extended sample with those from the twin sample alone and discuss implications for future research.

Mars habitat modules: launch, scaling and functional design considerations.

PubMed

Bell, Larry; Hines, Gerald D

2005-07-01

The Sasakawa International Center for Space Architecture (SICSA) is undertaking a multi-year research, planning and design study that is exploring near- and long-term commercial space development opportunities. The central goal of this activity is to conceptualize a scenario of sequential, integrated private enterprise initiatives that can carry humankind forward to Mars. Each development stage is planned as a building block to provide the economic foundation, technology advancements and operational infrastructure to support others that follow. This report presents fundamental issues and requirements associated with planning human Mars initiatives that can transfer crews, habitats and equipment from Earth to Mars orbit, deliver them to the planet's surface, and return people and samples safely back to Earth. The study builds in part upon previous studies which are summarized in SICSA's: Commercial Space Development Plan and the Artificial Gravity Science and Excursion Vehicle reports. Information and conclusions produced in this study provide assumptions and a conceptual foundation for a subsequent report titled The First Mars Outpost: Planning and Concepts. c2005 Elsevier Ltd. All rights reserved.

Status of Sample Return Propulsion Technology Development Under NASA's ISPT Program

NASA Technical Reports Server (NTRS)

Anderson, David J.; Glaab, Louis J.; Munk, Michelle M.; Pencil, Eric; Dankanich, John; Peterson, Todd T.

2012-01-01

The In-Space Propulsion Technology (ISPT) program was tasked in 2009 to start development of propulsion technologies that would enable future sample return missions. ISPT s sample return technology development areas are diverse. Sample Return Propulsion (SRP) addresses electric propulsion for sample return and low cost Discovery-class missions, propulsion systems for Earth Return Vehicles (ERV) including transfer stages to the destination, and low technology readiness level (TRL) advanced propulsion technologies. The SRP effort continues work on HIVHAC thruster development to transition into developing a Hall-effect propulsion system for sample return (ERV and transfer stages) and low-cost missions. Previous work on the lightweight propellant-tanks continues for sample return with direct applicability to a Mars Sample Return (MSR) mission with general applicability to all future planetary spacecraft. The Earth Entry Vehicle (EEV) work focuses on building a fundamental base of multi-mission technologies for Earth Entry Vehicles (MMEEV). The main focus of the Planetary Ascent Vehicles (PAV) area is technology development for the Mars Ascent Vehicle (MAV), which builds upon and leverages the past MAV analysis and technology developments from the Mars Technology Program (MTP) and previous MSR studies

Advanced multi-frequency radar: Design, preliminary measurements and particle size distribution retrieval

NASA Astrophysics Data System (ADS)

Majurec, Ninoslav

In the spring of 2001 the Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts began the development of an advanced Multi-Frequency Radar (AMFR) system for studying clouds and precipitation. This mobile radar was designed to consist of three polarimetric Doppler subsystems operating at Ku-band (13.4 GHz), Ka-band (35.6 GHz) and W-band (94.92 GHz). This combination of frequency bands allows a measurement of a wide range of atmospheric targets ranging from weakly reflecting clouds to strong precipitation. The antenna beamwidths at each frequency were intentionally matched, ensuring consistent sampling volume. Multi-frequency radar remote sensing techniques are not widely used because few multi-frequency radars are available to the science community. One exception is the 33 GHz/95 GHz UMass Cloud Profiling Radar System (CPRS), which AMFR is intended to replace. AMFR's multi-parameter capabilities are designed for characterizing the complex microphysics of layer clouds and precipitation processes in winter storms. AMFR will also play an important role in developing algorithms and validating measurements for an upcoming generation of space-borne radars. The frequency bands selected for AMFR match those of several sensors that have been deployed or are under development. These include the Japanese Aerospace Exploration Agencies (JAXA's) Tropical Rainfall Measuring Mission (TRMM) satellite Ku-band (13 GHz) radar, the CloudSat W-band (95 GHz) radar, and the Global Precipitation Mission (GPM) satellite radars at Ku-band and Ka-band. This dissertation describes the AMFR hardware design and development. Compared to CPRS, the addition of one extra frequency band (Ku) will extend AMFR's measurement capabilities towards the larger particle sizes (precipitation). AMFR's design is based around high-power klystron amplifiers. This ensures complete coherency (CPRS uses magnetrons and coherent-on-receive technique). The partial loss in sensitivity due to lower output power of klystron amplifiers (comparing to magnetrons) is compensated by use of pulse compression (linear FM). The problem of range sidelobes (pulse compression artifacts) has been solved by using appropriate windowing functions in the receiver. Satisfactory sidelobe suppression level of 45 dB has been demonstrated in the lab. The currently best achievable range resolution of the AMFR system is 30 m (corresponds to 5 MHz receiver BW, set by the sampling rate of the Analog-to-Digital card). During the design stage, various polarization schemes have been investigated. The polarization scheme analysis showed the switching polarization scheme to be the best suited for the AMFR system. The AMFR subsystems were partially finished in the winter of 2005. Some preliminary tests were conducted in January 2006. Antenna platform was fabricated in summer 2006. The final assembly took place in the fall of 2006. Early results are presented in the dissertation. These results were helpful in revealing of certain problems in the radar system (i.e. immediate processing computer synchronization) that needed to be addressed during system development. Stratiform rain event occurred on December 18 2006 has been analyzed in detail. A number of commonly used theoretical particle size distributions is presented. Furthermore, it is shown that a fully calibrated multi-frequency radar system has capability of separating scattering and attenuation effects. This was accomplished by fitting the theoretical models into the measured data. An alternative method of estimating rain rate that relies on the dual wavelength ratios is also presented. Although not as powerful as theoretical model fitting, it has its merits for off-zenith observations. During January 2007, AMFR system participated in the C3VP experiment (Canadian CloudSat/CALIPSO Validation Project) in south Ontario, Canada. Some of the data obtained during C3VP experiment has been analyzed and presented. Analysis of these two weather events resulted in the development of the initial multi-frequency particle size distribution retrieval algorithm.

Biomedical imaging with THz waves

NASA Astrophysics Data System (ADS)

Nguyen, Andrew

2010-03-01

We discuss biomedical imaging using radio waves operating in the terahertz (THz) range between 300 GHz to 3 THz. Particularly, we present the concept for two THz imaging systems. One system employs single antenna, transmitter and receiver operating over multi-THz-frequency simultaneously for sensing and imaging small areas of the human body or biological samples. Another system consists of multiple antennas, a transmitter, and multiple receivers operating over multi-THz-frequency capable of sensing and imaging simultaneously the whole body or large biological samples. Using THz waves for biomedical imaging promises unique and substantial medical benefits including extremely small medical devices, extraordinarily fine spatial resolution, and excellent contrast between images of diseased and healthy tissues. THz imaging is extremely attractive for detection of cancer in the early stages, sensing and imaging of tissues near the skin, and study of disease and its growth versus time.

Automatic Road Gap Detection Using Fuzzy Inference System

NASA Astrophysics Data System (ADS)

Hashemi, S.; Valadan Zoej, M. J.; Mokhtarzadeh, M.

2011-09-01

Automatic feature extraction from aerial and satellite images is a high-level data processing which is still one of the most important research topics of the field. In this area, most of the researches are focused on the early step of road detection, where road tracking methods, morphological analysis, dynamic programming and snakes, multi-scale and multi-resolution methods, stereoscopic and multi-temporal analysis, hyper spectral experiments, are some of the mature methods in this field. Although most researches are focused on detection algorithms, none of them can extract road network perfectly. On the other hand, post processing algorithms accentuated on the refining of road detection results, are not developed as well. In this article, the main is to design an intelligent method to detect and compensate road gaps remained on the early result of road detection algorithms. The proposed algorithm consists of five main steps as follow: 1) Short gap coverage: In this step, a multi-scale morphological is designed that covers short gaps in a hierarchical scheme. 2) Long gap detection: In this step, the long gaps, could not be covered in the previous stage, are detected using a fuzzy inference system. for this reason, a knowledge base consisting of some expert rules are designed which are fired on some gap candidates of the road detection results. 3) Long gap coverage: In this stage, detected long gaps are compensated by two strategies of linear and polynomials for this reason, shorter gaps are filled by line fitting while longer ones are compensated by polynomials.4) Accuracy assessment: In order to evaluate the obtained results, some accuracy assessment criteria are proposed. These criteria are obtained by comparing the obtained results with truly compensated ones produced by a human expert. The complete evaluation of the obtained results whit their technical discussions are the materials of the full paper.

Investigation on a thermal-coupled two-stage Stirling-type pulse tube cryocooler

NASA Astrophysics Data System (ADS)

Yang, Luwei

2008-11-01

Multi-stage Stirling-type pulse tube cryocoolers with high frequency (30-60 Hz) are one important direction in recent years. A two-stage Stirling-type pulse tube cryocooler with thermally coupled stages has been designed and established two years ago and some results have been published. In order to study the effect of first stage precooling temperature, related characteristics on performance are experimentally investigated. It shows that at high input power, when the precooling temperature is lower than 110 K, its effect on second stage temperature is quite small. There is also the evident effect of precooling temperature on pulse tube temperature distribution; this is for the first time that author notice the phenomenon. The mean working pressure is investigated and the 12.8 K lowest temperature with 500 W input power and 1.22 MPa average pressure have been gained, this is the lowest reported temperature for high frequency two-stage PTCS. Simulation has reflected upper mentioned typical features in experiments.

Leveraging multi-layer imager detector design to improve low-dose performance for megavoltage cone-beam computed tomography

NASA Astrophysics Data System (ADS)

Hu, Yue-Houng; Rottmann, Joerg; Fueglistaller, Rony; Myronakis, Marios; Wang, Adam; Huber, Pascal; Shedlock, Daniel; Morf, Daniel; Baturin, Paul; Star-Lack, Josh; Berbeco, Ross

2018-02-01

While megavoltage cone-beam computed tomography (CBCT) using an electronic portal imaging device (EPID) provides many advantages over kilovoltage (kV) CBCT, clinical adoption is limited by its high doses. Multi-layer imager (MLI) EPIDs increase DQE(0) while maintaining high resolution. However, even well-designed, high-performance MLIs suffer from increased electronic noise from each readout, degrading low-dose image quality. To improve low-dose performance, shift-and-bin addition (ShiBA) imaging is proposed, leveraging the unique architecture of the MLI. ShiBA combines hardware readout-binning and super-resolution concepts, reducing electronic noise while maintaining native image sampling. The imaging performance of full-resolution (FR); standard, aligned binned (BIN); and ShiBA images in terms of noise power spectrum (NPS), electronic NPS, modulation transfer function (MTF), and the ideal observer signal-to-noise ratio (SNR)—the detectability index (d‧)—are compared. The FR 4-layer readout of the prototype MLI exhibits an electronic NPS magnitude 6-times higher than a state-of-the-art single layer (SLI) EPID. Although the MLI is built on the same readout platform as the SLI, with each layer exhibiting equivalent electronic noise, the multi-stage readout of the MLI results in electronic noise 50% higher than simple summation. Electronic noise is mitigated in both BIN and ShiBA imaging, reducing its total by ~12 times. ShiBA further reduces the NPS, effectively upsampling the image, resulting in a multiplication by a sinc2 function. Normalized NPS show that neither ShiBA nor BIN otherwise affects image noise. The LSF shows that ShiBA removes the pixilation artifact of BIN images and mitigates the effect of detector shift, but does not quantifiably improve the MTF. ShiBA provides a pre-sampled representation of the images, mitigating phase dependence. Hardware binning strategies lower the quantum noise floor, with 2  ×  2 implementation reducing the dose at which DQE(0) degrades by 10% from 0.01 MU to 0.004 MU, representing 20% improvement in d‧.

Multi-Point Combustion System: Final Report

NASA Technical Reports Server (NTRS)

Goeke, Jerry; Pack, Spencer; Zink, Gregory; Ryon, Jason

2014-01-01

A low-NOx emission combustor concept has been developed for NASA's Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 lb thrust engine application. These goals include 75 percent reduction of LTO NOx from CAEP6 standards without increasing CO, UHC, or smoke from that of current state of the art. An additional key factor in this work is to improve lean combustion stability over that of previous work performed on similar technology in the early 2000s. The purpose of this paper is to present the final report for the NASA contract. This work included the design, analysis, and test of a multi-point combustion system. All design work was based on the results of Computational Fluid Dynamics modeling with the end results tested on a medium pressure combustion rig at the UC and a medium pressure combustion rig at GRC. The theories behind the designs, results of analysis, and experimental test data will be discussed in this report. The combustion system consists of five radially staged rows of injectors, where ten small scale injectors are used in place of a single traditional nozzle. Major accomplishments of the current work include the design of a Multipoint Lean Direct Injection (MLDI) array and associated air blast and pilot fuel injectors, which is expected to meet or exceed the goal of a 75 percent reduction in LTO NOx from CAEP6 standards. This design incorporates a reduced number of injectors over previous multipoint designs, simplified and lightweight components, and a very compact combustor section. Additional outcomes of the program are validation that the design of these combustion systems can be aided by the use of Computational Fluid Dynamics to predict and reduce emissions. Furthermore, the staging of fuel through the individually controlled radially staged injector rows successfully demonstrated improved low power operability as well as improvements in emissions over previous multipoint designs. Additional comparison between Jet- A fuel and a hydrotreated biofuel is made to determine viability of the technology for use with alternative fuels. Finally, the operability of the array and associated nozzles proved to be very stable without requiring additional active or passive control systems. A number of publications have been publish

Deep Convolutional Neural Networks for Multi-Modality Isointense Infant Brain Image Segmentation

PubMed Central

Zhang, Wenlu; Li, Rongjian; Deng, Houtao; Wang, Li; Lin, Weili; Ji, Shuiwang; Shen, Dinggang

2015-01-01

The segmentation of infant brain tissue images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) plays an important role in studying early brain development in health and disease. In the isointense stage (approximately 6–8 months of age), WM and GM exhibit similar levels of intensity in both T1 and T2 MR images, making the tissue segmentation very challenging. Only a small number of existing methods have been designed for tissue segmentation in this isointense stage; however, they only used a single T1 or T2 images, or the combination of T1 and T2 images. In this paper, we propose to use deep convolutional neural networks (CNNs) for segmenting isointense stage brain tissues using multi-modality MR images. CNNs are a type of deep models in which trainable filters and local neighborhood pooling operations are applied alternatingly on the raw input images, resulting in a hierarchy of increasingly complex features. Specifically, we used multimodality information from T1, T2, and fractional anisotropy (FA) images as inputs and then generated the segmentation maps as outputs. The multiple intermediate layers applied convolution, pooling, normalization, and other operations to capture the highly nonlinear mappings between inputs and outputs. We compared the performance of our approach with that of the commonly used segmentation methods on a set of manually segmented isointense stage brain images. Results showed that our proposed model significantly outperformed prior methods on infant brain tissue segmentation. In addition, our results indicated that integration of multi-modality images led to significant performance improvement. PMID:25562829

Evaluating multi-level models to test occupancy state responses of Plethodontid salamanders

USGS Publications Warehouse

Kroll, Andrew J.; Garcia, Tiffany S.; Jones, Jay E.; Dugger, Catherine; Murden, Blake; Johnson, Josh; Peerman, Summer; Brintz, Ben; Rochelle, Michael

2015-01-01

Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology and responses to conservation and management activities. We conducted a simulation study to evaluate the effectiveness of multi-scale and hierarchical single-scale occupancy models in the context of a Before-After Control-Impact (BACI) experimental design with multiple levels of sampling. Also, we fit the hierarchical single-scale model to empirical data collected for Oregon slender and Ensatina salamanders across two years on 66 forest stands in the Cascade Range, Oregon, USA. All models were fit within a Bayesian framework. Estimator precision in both models improved with increasing numbers of primary and secondary sampling units, underscoring the potential gains accrued when adding secondary sampling units. Both models showed evidence of estimator bias at low detection probabilities and low sample sizes; this problem was particularly acute for the multi-scale model. Our results suggested that sufficient sample sizes at both the primary and secondary sampling levels could ameliorate this issue. Empirical data indicated Oregon slender salamander occupancy was associated strongly with the amount of coarse woody debris (posterior mean = 0.74; SD = 0.24); Ensatina occupancy was not associated with amount of coarse woody debris (posterior mean = -0.01; SD = 0.29). Our simulation results indicate that either model is suitable for use in an experimental study of Plethodontid salamanders provided that sample sizes are sufficiently large. However, hierarchical single-scale and multi-scale models describe different processes and estimate different parameters. As a result, we recommend careful consideration of study questions and objectives prior to sampling data and fitting models.

Multi-contaminant analysis of organophosphate and halogenated flame retardants in food matrices using ultrasonication and vacuum assisted extraction, multi-stage cleanup and gas chromatography-mass spectrometry.

PubMed

Xu, Fuchao; García-Bermejo, Ángel; Malarvannan, Govindan; Gómara, Belén; Neels, Hugo; Covaci, Adrian

2015-07-03

A multi-residue analytical method was developed for the determination of a range of flame retardants (FRs), including polybrominated diphenyl ethers (PBDEs), emerging halogenated FRs (EFRs) and organophosphate FRs (PFRs), in food matrices. An ultrasonication and vacuum assisted extraction (UVAE), followed by a multi-stage clean-up procedure, enabled the removal of up to 1g of lipid from 2.5 g of freeze-dried food samples and significantly reduce matrix effects. UVAE achieves a waste factor (WF) of about 10%, while the WFs of classical QuEChERS methods range usually between 50 and 90%. The low WF of UVAE leads to a dramatic improvement in the sensitivity along with saving up to 90% of spiking (internal) standards. Moreover, a two-stage clean-up on Florisil and aminopropyl silica was introduced after UVAE, for an efficient removal of pigments and residual lipids, which led to cleaner extracts than normally achieved by dispersive solid phase extraction (d-SPE). In this way, the extracts could be concentrated to low volumes, e.g. <100 μL and the equivalent matrix concentrations were up to 100g ww/mL. The final analysis of PFRs was performed on GC-EI-MS, while PBDEs and EFRs were measured by GC-ECNI-MS. Validation tests were performed with three food matrices (lean beef, whole chicken egg and salmon filet), obtaining acceptable recoveries (66-135%) with good repeatability (RSD 1-24%, mean 7%). Method LOQs ranged between 0.008 and 0.04 ng/g dw for PBDEs, between 0.08 and 0.20 ng/g dw for EFRs, and between 1.4 and 3.6 ng/g dw for PFRs. The method was further applied to eight types of food samples (including meat, eggs, fish, and seafood) with lipid contents ranging from 0.1 to 22%. Various FRs were detected above MLOQ levels, demonstrating the wide-range applicability of our method. To the best of our knowledge, this is the first method reported for simultaneous analysis of brominated and organophosphate FRs in food matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

Real-time SHVC software decoding with multi-threaded parallel processing

NASA Astrophysics Data System (ADS)

Gudumasu, Srinivas; He, Yuwen; Ye, Yan; He, Yong; Ryu, Eun-Seok; Dong, Jie; Xiu, Xiaoyu

2014-09-01

This paper proposes a parallel decoding framework for scalable HEVC (SHVC). Various optimization technologies are implemented on the basis of SHVC reference software SHM-2.0 to achieve real-time decoding speed for the two layer spatial scalability configuration. SHVC decoder complexity is analyzed with profiling information. The decoding process at each layer and the up-sampling process are designed in parallel and scheduled by a high level application task manager. Within each layer, multi-threaded decoding is applied to accelerate the layer decoding speed. Entropy decoding, reconstruction, and in-loop processing are pipeline designed with multiple threads based on groups of coding tree units (CTU). A group of CTUs is treated as a processing unit in each pipeline stage to achieve a better trade-off between parallelism and synchronization. Motion compensation, inverse quantization, and inverse transform modules are further optimized with SSE4 SIMD instructions. Simulations on a desktop with an Intel i7 processor 2600 running at 3.4 GHz show that the parallel SHVC software decoder is able to decode 1080p spatial 2x at up to 60 fps (frames per second) and 1080p spatial 1.5x at up to 50 fps for those bitstreams generated with SHVC common test conditions in the JCT-VC standardization group. The decoding performance at various bitrates with different optimization technologies and different numbers of threads are compared in terms of decoding speed and resource usage, including processor and memory.

NASA Ares I Crew Launch Vehicle Upper State Overview

NASA Technical Reports Server (NTRS)

Davis, Daniel J.

2008-01-01

By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA s Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program s transportation system.

Producing Multimodal Picture Books and Dramatic Performances in a Core French Classroom: An Exploratory Case Study

ERIC Educational Resources Information Center

Early, Margaret; Yeung, Cindy

2009-01-01

In a Grade 9 core French class, the teacher designed a multi-stage project in which students composed original children's stories in French; illustrated their stories to produce picture books; then, in groups, adapted one group member's story into a play script; and, finally, dramatized the scripts for children from the local French immersion…

Influence of dispatching rules on average production lead time for multi-stage production systems.

PubMed

Hübl, Alexander; Jodlbauer, Herbert; Altendorfer, Klaus

2013-08-01

In this paper the influence of different dispatching rules on the average production lead time is investigated. Two theorems based on covariance between processing time and production lead time are formulated and proved theoretically. Theorem 1 links the average production lead time to the "processing time weighted production lead time" for the multi-stage production systems analytically. The influence of different dispatching rules on average lead time, which is well known from simulation and empirical studies, can be proved theoretically in Theorem 2 for a single stage production system. A simulation study is conducted to gain more insight into the influence of dispatching rules on average production lead time in a multi-stage production system. We find that the "processing time weighted average production lead time" for a multi-stage production system is not invariant of the applied dispatching rule and can be used as a dispatching rule independent indicator for single-stage production systems.

Stages of Change in Relationship Status Questionnaire: Development and Validation

ERIC Educational Resources Information Center

Ritter, Kathrin; Handsel, Vanessa; Moore, Todd

2016-01-01

This study involved the development of the Stages of Change in Relationship Status (SOCRS) measure in 2 samples of college students. This scale is designed to measure how individuals progress through stages of change when terminating violent and nonviolent intimate relationships. Results indicated that the SOCRS is a reliable and valid tool to…

Series Bosch System Development

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Evans, Christopher; Mansell, Matt; Swickrath, Michael

2012-01-01

State-of-the-art (SOA) carbon dioxide (CO2) reduction technology for the International Space Station produces methane as a byproduct. This methane is subsequently vented overboard. The associated loss of hydrogen ultimately reduces the mass of oxygen that can be recovered from CO2 in a closed-loop life support system. As an alternative to SOA CO2 reduction technology, NASA is exploring a Series-Bosch system capable of reducing CO2 with hydrogen to form water and solid carbon. This results in 100% theoretical recovery of oxygen from metabolic CO2. In the past, Bosch-based technology did not trade favorably against SOA technology due to a high power demand, low reaction efficiencies, concerns with carbon containment, and large resupply requirements necessary to replace expended catalyst cartridges. An alternative approach to Bosch technology, labeled "Series-Bosch," employs a new system design with optimized multi-stage reactors and a membrane-based separation and recycle capability. Multi-physics modeling of the first stage reactor, along with chemical process modeling of the integrated system, has resulted in a design with potential to trade significantly better than previous Bosch technology. The modeling process and resulting system architecture selection are discussed.

Enhancing Community Knowledge and Health Behaviors to Eliminate Blinding Trachoma in Mali Using Radio Messaging as a Strategy

ERIC Educational Resources Information Center

Bamani, Sanoussi; Toubali, Emily; Diarra, Sadio; Goita, Seydou; Berte, Zana; Coulibaly, Famolo; Sangare, Hama; Tuinsma, Marjon; Zhang, Yaobi; Dembele, Benoit; Melvin, Palesa; MacArthur, Chad

2013-01-01

The National Blindness Prevention Program in Mali has broadcast messages on the radio about trachoma as part of the country's trachoma elimination strategy since 2008. In 2011, a radio impact survey using multi-stage cluster sampling was conducted in the regions of Kayes and Segou to assess radio listening habits, coverage of the broadcasts,…

Teacher Self-Efficacy Enhancement and School Location: Implication for Students' Achievement in Economics in Senior Secondary School in Ibadan, Oyo State, Nigeria

ERIC Educational Resources Information Center

Durowoju, Esther O.; Onuka, Adams O. U.

2015-01-01

The paper investigated the effect of teacher self-efficacy enhancement and school location on students' achievement in Economics in Senior Secondary School in Ibadan Metropolis of Oyo State, Nigeria. Three hypotheses were tested at 0.05 level of significance. Multi-stage sampling technique was adopted in the study. Four Local Government Areas (two…

Prevalence and genotyping ofToxoplasma gondii among Saudi pregnant women in Saudi Arabia.

PubMed

Alghamdi, Jawahir; Elamin, Maha Hussein; Alhabib, Samia

2016-11-01

Introduction: Toxoplasma gondii ( T. gondii ) is an intracellular protozoan that can infect all mammals, who serve as intermediate host. It causes congenital, neurological, eyes complications and mild or asymptomatic infections in humans. Purpose of this study: To investigate not only the prevalence of T. gondii , but also to find out its genotyping using multiple sequential molecular methods to predict exactly the precise genotyping of T. gondii among Saudi pregnant women. Methods: A cross-sectional study was conducted using multi-stage methods. Initial stage involved enrolment of 250 Saudi pregnant women from multi-centre healthcare and community based settings in the capital of Saudi Arabia Riyadh. The second stage was embracement of the laboratory investigation that included Enzyme immunoassay (ELISA), DNA extraction, PCR, nested-PCR assay, and genotyping of the seropositive cases. Results: 203 women agreed to take part in our study with a response rate of 81.2% (203/250). Using ELISA, we found that the prevalence of Toxoplasma gondii IgG and IgM antibodies was 32.5% and 6.4%, respectively. We found that 29 samples (80.6%) were of genotype II; however 7 samples (19.4%) were of genotype III. Conclusion: Defining the population structure of T. gondii from Saudi Arabia has important implications for transmission, immunogenicity, pathogenesis, and in planning preventive strategies. Relationship between such variation in structure and disease manifestation in pregnant women is still difficult to assess due to the role of host immune status and genetic background on the control of infection, and of other parasitic features such as the infecting dose or parasite stage. Our finding of the genotyping of T. gondii might facilitate and inform future studies on comparative genomics and identification of genes that control important biological phenotypes including pathogenesis and transmission among Saudi women.

Methodological proposal for the remediation of a site affected by phosphogypsum deposits

NASA Astrophysics Data System (ADS)

Martínez-Sanchez, M. J.; Perez-Sirvent, C.; Bolivar, J. P.; Garcia-Tenorio, R.

2012-04-01

The accumulation of phosphogysum (PY) produces a well known environmental problems. The proposals for the remediation of these sites require multidisciplinary and very specific studies. Since they cover large areas a sampling design specifically outlined for each case is necessary in order the contaminants, transfer pathways and particular processes can be correctly identified. In addition to a suitable sampling of the soil, aquatic medium and biota, appropriate studies of the space-temporal variations by means of control samples are required. Two different stages should be considered: 1.- Diagnostic stage This stage includes preliminary studies, identification of possible sources of radiosotopes, design of the appropriate sampling plan, hydrogeological study, characterization and study of the space-temporal variability of radioisotopes and other contaminants, as well as the risk assessement for health and ecosystems, that depends on the future use of the site. 2.- Remediation proposal stage It comprises the evaluation and comparison of the different procedures for the decontamination/remediation, including models experiments at the laboratory. To this respect, the preparation and detailed study of a small scale pilot project is a task of particular relevance. In this way the suitability of the remediating technology can be checked, and its performance optimized. These two stages allow a technically well-founded proposal to be presented to the Organisms or Institutions in charge of the problem and facilitate decision-making. It both stages be included in a social communication campaign in order the final proposal be accepted by stakeholders.

Comparability among four invertebrate sampling methods, Fountain Creek Basin, Colorado, 2010-2012

USGS Publications Warehouse

Zuellig, Robert E.; Bruce, James F.; Stogner, Sr., Robert W.; Brown, Krystal D.

2014-01-01

The U.S. Geological Survey, in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, designed a study to determine if sampling method and sample timing resulted in comparable samples and assessments of biological condition. To accomplish this task, annual invertebrate samples were collected concurrently using four sampling methods at 15 U.S. Geological Survey streamflow gages in the Fountain Creek basin from 2010 to 2012. Collectively, the four methods are used by local (U.S. Geological Survey cooperative monitoring program) and State monitoring programs (Colorado Department of Public Health and Environment) in the Fountain Creek basin to produce two distinct sample types for each program that target single-and multiple-habitats. This study found distinguishable differences between single-and multi-habitat sample types using both community similarities and multi-metric index values, while methods from each program within sample type were comparable. This indicates that the Colorado Department of Public Health and Environment methods were compatible with the cooperative monitoring program methods within multi-and single-habitat sample types. Comparisons between September and October samples found distinguishable differences based on community similarities for both sample types, whereas only differences were found for single-habitat samples when multi-metric index values were considered. At one site, differences between September and October index values from single-habitat samples resulted in opposing assessments of biological condition. Direct application of the results to inform the revision of the existing Fountain Creek basin U.S. Geological Survey cooperative monitoring program are discussed.

Operation of staged membrane oxidation reactor systems

DOEpatents

Repasky, John Michael

2012-10-16

A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

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.

Energy Technology Allocation for Distributed Energy Resources: A Technology-Policy Framework

NASA Astrophysics Data System (ADS)

Mallikarjun, Sreekanth

Distributed energy resources (DER) are emerging rapidly. New engineering technologies, materials, and designs improve the performance and extend the range of locations for DER. In contrast, constructing new or modernizing existing high voltage transmission lines for centralized generation are expensive and challenging. In addition, customer demand for reliability has increased and concerns about climate change have created a pull for swift renewable energy penetration. In this context, DER policy makers, developers, and users are interested in determining which energy technologies to use to accommodate different end-use energy demands. We present a two-stage multi-objective strategic technology-policy framework for determining the optimal energy technology allocation for DER. The framework simultaneously considers economic, technical, and environmental objectives. The first stage utilizes a Data Envelopment Analysis model for each end-use to evaluate the performance of each energy technology based on the three objectives. The second stage incorporates factor efficiencies determined in the first stage, capacity limitations, dispatchability, and renewable penetration for each technology, and demand for each end-use into a bottleneck multi-criteria decision model which provides the Pareto-optimal energy resource allocation. We conduct several case studies to understand the roles of various distributed energy technologies in different scenarios. We construct some policy implications based on the model results of set of case studies.

Goal-oriented cognitive rehabilitation in early-stage dementia: study protocol for a multi-centre single-blind randomised controlled trial (GREAT)

PubMed Central

2013-01-01

Background Preliminary evidence suggests that goal-oriented cognitive rehabilitation (CR) may be a clinically effective intervention for people with early-stage Alzheimer’s disease, vascular or mixed dementia and their carers. This study aims to establish whether CR is a clinically effective and cost-effective intervention for people with early-stage dementia and their carers. Methods/design In this multi-centre, single-blind randomised controlled trial, 480 people with early-stage dementia, each with a carer, will be randomised to receive either treatment as usual or cognitive rehabilitation (10 therapy sessions over 3 months, followed by 4 maintenance sessions over 6 months). We will compare the effectiveness of cognitive rehabilitation with that of treatment as usual with regard to improving self-reported and carer-rated goal performance in areas identified as causing concern by people with early-stage dementia; improving quality of life, self-efficacy, mood and cognition of people with early-stage dementia; and reducing stress levels and ameliorating quality of life for carers of participants with early-stage dementia. The incremental cost-effectiveness of goal-oriented cognitive rehabilitation compared to treatment as usual will also be examined. Discussion If the study confirms the benefits and cost-effectiveness of cognitive rehabilitation, it will be important to examine how the goal-oriented cognitive rehabilitation approach can most effectively be integrated into routine health-care provision. Our aim is to provide training and develop materials to support the implementation of this approach following trial completion. Trial registration Current Controlled Trials ISRCTN21027481 PMID:23710796

Technology-based design and scaling for RTGs for space exploration in the 100 W range

NASA Astrophysics Data System (ADS)

Summerer, Leopold; Pierre Roux, Jean; Pustovalov, Alexey; Gusev, Viacheslav; Rybkin, Nikolai

2011-04-01

This paper presents the results of a study on design considerations for a 100 W radioisotope thermo-electric generator (RTG). Special emphasis has been put on designing a modular, multi-purpose system with high overall TRL levels and making full use of the extensive Russian heritage in the design of radioisotope power systems. The modular approach allowed insight into the scaling of such RTGs covering the electric power range from 50 to 200 W e (EoL). The retained concept is based on a modular thermal block structure, a radiative inner-RTG heat transfer and using a two-stage thermo-electric conversion system.

Multi-turn transmit coil to increase b1 efficiency in current source amplification.

PubMed

Gudino, N; Griswold, M A

2013-04-01

A multi-turn transmit surface coil design was presented to improve B1 efficiency when used with current source amplification. Three different coil designs driven by an on-coil current-mode class-D amplifier with current envelope feedback were tested on the benchtop and through imaging in a 1.5 T scanner. Case temperature of the power field-effect transistor at the amplifier output stage was measured to evaluate heat dissipation for the different current levels and coil configurations. In addition, a lower power rated device was tested to exploit the potential gain in B1 obtained with the multi-turn coil. As shown both on the benchtop and in a 1.5 T scanner, B1 was increased by almost 3-fold without increasing heat dissipation on the power device at the amplifier's output using a multi-turn surface coil. Similar gain was obtained when connecting a lower power rated field-effect transistor to the multi-turn coil. In addition to reduce heat dissipation per B1 in the device, higher B1 per current efficiency allows the use of field-effect transistors with lower current ratings and lower port capacitances, which could improve the overall performance of the on-coil current source transmit system. Copyright © 2013 Wiley Periodicals, Inc.

Multi-turn transmit coil to increase B1 efficiency in current source amplification

PubMed Central

Gudino, N.; Griswold, M.A.

2013-01-01

Purpose A multi-turn transmit surface coil design was presented to improve B1 efficiency when used with current source amplification. Methods Three different coil designs driven by an on-coil current-mode class-D (CMCD) amplifier with current envelope feedback were tested on the benchtop and through imaging in a 1.5 T scanner. Case temperature of the power field-effect transistor (FET) at the amplifier output stage was measured to evaluate heat dissipation for the different current levels and coil configurations. In addition, a lower power rated device was tested to exploit the potential gain in B1 obtained with the multi-turn coil. Results As shown both on the benchtop and in a 1.5 T scanner, B1 was increased by almost three-fold without increasing heat dissipation on the power device at the amplifier's output using a multi-turn surface coil. Similar gain was obtained when connecting a lower power rated FET to the multi-turn coil. Conclusion In addition to reduce heat dissipation per B1 in the device, higher B1 per current efficiency allows the use of FETs with lower current ratings and lower port capacitances which could improve the overall performance of the on-coil current source transmit system. PMID:23401060

Multifunctional Collaborative Modeling and Analysis Methods in Engineering Science

NASA Technical Reports Server (NTRS)

Ransom, Jonathan B.; Broduer, Steve (Technical Monitor)

2001-01-01

Engineers are challenged to produce better designs in less time and for less cost. Hence, to investigate novel and revolutionary design concepts, accurate, high-fidelity results must be assimilated rapidly into the design, analysis, and simulation process. This assimilation should consider diverse mathematical modeling and multi-discipline interactions necessitated by concepts exploiting advanced materials and structures. Integrated high-fidelity methods with diverse engineering applications provide the enabling technologies to assimilate these high-fidelity, multi-disciplinary results rapidly at an early stage in the design. These integrated methods must be multifunctional, collaborative, and applicable to the general field of engineering science and mechanics. Multifunctional methodologies and analysis procedures are formulated for interfacing diverse subdomain idealizations including multi-fidelity modeling methods and multi-discipline analysis methods. These methods, based on the method of weighted residuals, ensure accurate compatibility of primary and secondary variables across the subdomain interfaces. Methods are developed using diverse mathematical modeling (i.e., finite difference and finite element methods) and multi-fidelity modeling among the subdomains. Several benchmark scalar-field and vector-field problems in engineering science are presented with extensions to multidisciplinary problems. Results for all problems presented are in overall good agreement with the exact analytical solution or the reference numerical solution. Based on the results, the integrated modeling approach using the finite element method for multi-fidelity discretization among the subdomains is identified as most robust. The multiple-method approach is advantageous when interfacing diverse disciplines in which each of the method's strengths are utilized. The multifunctional methodology presented provides an effective mechanism by which domains with diverse idealizations are interfaced. This capability rapidly provides the high-fidelity results needed in the early design phase. Moreover, the capability is applicable to the general field of engineering science and mechanics. Hence, it provides a collaborative capability that accounts for interactions among engineering analysis methods.

Multi-stage pulse tube cryocooler with acoustic impedance constructed to reduce transient cool down time and thermal loss

NASA Technical Reports Server (NTRS)

Gedeon, David R. (Inventor); Wilson, Kyle B. (Inventor)

2008-01-01

The cool down time for a multi-stage, pulse tube cryocooler is reduced by configuring at least a portion of the acoustic impedance of a selected stage, higher than the first stage, so that it surrounds the cold head of the selected stage. The surrounding acoustic impedance of the selected stage is mounted in thermally conductive connection to the warm region of the selected stage for cooling the acoustic impedance and is fabricated of a high thermal diffusivity, low thermal radiation emissivity material, preferably aluminum.

Progress toward Modular UAS for Geoscience Applications

NASA Astrophysics Data System (ADS)

Dahlgren, R. P.; Clark, M. A.; Comstock, R. J.; Fladeland, M.; Gascot, H., III; Haig, T. H.; Lam, S. J.; Mazhari, A. A.; Palomares, R. R.; Pinsker, E. A.; Prathipati, R. T.; Sagaga, J.; Thurling, J. S.; Travers, S. V.

2017-12-01

Small Unmanned Aerial Systems (UAS) have become accepted tools for geoscience, ecology, agriculture, disaster response, land management, and industry. A variety of consumer UAS options exist as science and engineering payload platforms, but their incompatibilities with one another contribute to high operational costs compared with those of piloted aircraft. This research explores the concept of modular UAS, demonstrating airframes that can be reconfigured in the field for experimental optimization, to enable multi-mission support, facilitate rapid repair, or respond to changing field conditions. Modular UAS is revolutionary in allowing aircraft to be optimized around the payload, reversing the conventional wisdom of designing the payload to accommodate an unmodifiable aircraft. UAS that are reconfigurable like Legos™ are ideal for airborne science service providers, system integrators, instrument designers and end users to fulfill a wide range of geoscience experiments. Modular UAS facilitate the adoption of open-source software and rapid prototyping technology where design reuse is important in the context of a highly regulated industry like aerospace. The industry is now at a stage where consolidation, acquisition, and attrition will reduce the number of small manufacturers, with a reduction of innovation and motivation to reduce costs. Modularity leads to interface specifications, which can evolve into de facto or formal standards which contain minimum (but sufficient) details such that multiple vendors can then design to those standards and demonstrate interoperability. At that stage, vendor coopetition leads to robust interface standards, interoperability standards and multi-source agreements which in turn drive costs down significantly.

Prednisolone and acupuncture in Bell's palsy: study protocol for a randomized, controlled trial.

PubMed

Xia, Feng; Han, Junliang; Liu, Xuedong; Wang, Jingcun; Jiang, Zhao; Wang, Kangjun; Wu, Songdi; Zhao, Gang

2011-06-21

There are a variety of treatment options for Bell's palsy. Evidence from randomized controlled trials indicates corticosteroids can be used as a proven therapy for Bell's palsy. Acupuncture is one of the most commonly used methods to treat Bell's palsy in China. Recent studies suggest that staging treatment is more suitable for Bell's palsy, according to different path-stages of this disease. The aim of this study is to compare the effects of prednisolone and staging acupuncture in the recovery of the affected facial nerve, and to verify whether prednisolone in combination with staging acupuncture is more effective than prednisolone alone for Bell's palsy in a large number of patients. In this article, we report the design and protocol of a large sample multi-center randomized controlled trial to treat Bell's palsy with prednisolone and/or acupuncture. In total, 1200 patients aged 18 to 75 years within 72 h of onset of acute, unilateral, peripheral facial palsy will be assessed. There are six treatment groups, with four treated according to different path-stages and two not. These patients are randomly assigned to be in one of the following six treatment groups, i.e. 1) placebo prednisolone group, 2) prednisolone group, 3) placebo prednisolone plus acute stage acupuncture group, 4) prednisolone plus acute stage acupuncture group, 5) placebo prednisolone plus resting stage acupuncture group, 6) prednisolone plus resting stage acupuncture group. The primary outcome is the time to complete recovery of facial function, assessed by Sunnybrook system and House-Brackmann scale. The secondary outcomes include the incidence of ipsilateral pain in the early stage of palsy (and the duration of this pain), the proportion of patients with severe pain, the occurrence of synkinesis, facial spasm or contracture, and the severity of residual facial symptoms during the study period. The result of this trial will assess the efficacy of using prednisolone and staging acupuncture to treat Bell's palsy, and to determine a best combination therapy with prednisolone and acupuncture for treating Bell's palsy. ClinicalTrials.gov: NCT01201642.

The role of self-efficacy and assertiveness in aggression among high-school students in Isfahan.

PubMed

Khademi Mofrad, S H; Mehrabi, T

2015-01-01

Background. Nowadays, one sixth of the world's population is represented by adolescents, nearly 1.2 billion people being of age 10-19. According to the 2011 census in Iran, the estimation of adolescent population was 12 million, which represents 16% of the Iran population. Undoubtedly, adolescence is the most dominant stage of life. During this period, adolescents face biological, cognitive, and emotional changes that may be accompanied by inappropriate behavioral responses such as aggression. Considering pressures of peer groups during adolescence, assertiveness has an important role as a social skill. It seems that the success of adolescents in dealing with these problems depends on their self-efficacy. This study was designed to explore the role of self-efficacy and assertiveness in aggression among high-school students. Material and methods. This cross-sectional and correlational study was conducted among 321 first grade high-school students during 2014 and 2015. Samples were extracted from six education and training regions by a multi-stage random sampling. In this study, the questionnaire included demographic, Rathus Assertiveness, self-efficacy for children and aggression data. Results. The results showed that there was a notable negative association between aggression and assertiveness (p < 0.003) and also between assault and self-efficacy (p < 0.001). Conclusions. An increase in assertiveness and self-efficacy resulted in a decrease of aggression. So, training was recommended to reinforce self-efficacy beliefs and assertiveness behaviors for mental health promotion.

The role of self-efficacy and assertiveness in aggression among high-school students in Isfahan

PubMed Central

Khademi Mofrad, SH; Mehrabi, T

2015-01-01

Background. Nowadays, one sixth of the world’s population is represented by adolescents, nearly 1.2 billion people being of age 10-19. According to the 2011 census in Iran, the estimation of adolescent population was 12 million, which represents 16% of the Iran population. Undoubtedly, adolescence is the most dominant stage of life. During this period, adolescents face biological, cognitive, and emotional changes that may be accompanied by inappropriate behavioral responses such as aggression. Considering pressures of peer groups during adolescence, assertiveness has an important role as a social skill. It seems that the success of adolescents in dealing with these problems depends on their self-efficacy. This study was designed to explore the role of self-efficacy and assertiveness in aggression among high-school students. Material and methods. This cross-sectional and correlational study was conducted among 321 first grade high-school students during 2014 and 2015. Samples were extracted from six education and training regions by a multi-stage random sampling. In this study, the questionnaire included demographic, Rathus Assertiveness, self-efficacy for children and aggression data. Results. The results showed that there was a notable negative association between aggression and assertiveness (p < 0.003) and also between assault and self-efficacy (p < 0.001). Conclusions. An increase in assertiveness and self-efficacy resulted in a decrease of aggression. So, training was recommended to reinforce self-efficacy beliefs and assertiveness behaviors for mental health promotion. PMID:28316736

GNSS software receiver sampling noise and clock jitter performance and impact analysis

NASA Astrophysics Data System (ADS)

Chen, Jian Yun; Feng, XuZhe; Li, XianBin; Wu, GuangYao

2015-02-01

In the design of a multi-frequency multi-constellation GNSS software defined radio receivers is becoming more and more popular due to its simple architecture, flexible configuration and good coherence in multi-frequency signal processing. It plays an important role in navigation signal processing and signal quality monitoring. In particular, GNSS software defined radio receivers driving the sampling clock of analogue-to-digital converter (ADC) by FPGA implies that a more flexible radio transceiver design is possible. According to the concept of software defined radio (SDR), the ideal is to digitize as close to the antenna as possible. Whereas the carrier frequency of GNSS signal is of the frequency of GHz, converting at this frequency is expensive and consumes more power. Band sampling method is a cheaper, more effective alternative. When using band sampling method, it is possible to sample a RF signal at twice the bandwidth of the signal. Unfortunately, as the other side of the coin, the introduction of SDR concept and band sampling method induce negative influence on the performance of the GNSS receivers. ADC's suffer larger sampling clock jitter generated by FPGA; and low sampling frequency introduces more noise to the receiver. Then the influence of sampling noise cannot be neglected. The paper analyzes the sampling noise, presents its influence on the carrier noise ratio, and derives the ranging error by calculating the synchronization error of the delay locked loop. Simulations aiming at each impact factors of sampling-noise-induced ranging error are performed. Simulation and experiment results show that if the target ranging accuracy is at the level of centimeter, the quantization length should be no less than 8 and the sampling clock jitter should not exceed 30ps.

A scanning tunneling microscope with a scanning range from hundreds of micrometers down to nanometer resolution.

PubMed

Kalkan, Fatih; Zaum, Christopher; Morgenstern, Karina

2012-10-01

A beetle type stage and a flexure scanning stage are combined to form a two stages scanning tunneling microscope (STM). It operates at room temperature in ultrahigh vacuum and is capable of scanning areas up to 300 μm × 450 μm down to resolution on the nanometer scale. This multi-scale STM has been designed and constructed in order to investigate prestructured metallic or semiconducting micro- and nano-structures in real space from atomic-sized structures up to the large-scale environment. The principle of the instrument is demonstrated on two different systems. Gallium nitride based micropillars demonstrate scan areas up to hundreds of micrometers; a Au(111) surface demonstrates nanometer resolution.

Psychosocial stress and multi-site musculoskeletal pain: a cross-sectional survey of patient care workers.

PubMed

Sembajwe, Grace; Tveito, Torill Helene; Hopcia, Karen; Kenwood, Christopher; O'Day, Elizabeth Tucker; Stoddard, Anne M; Dennerlein, Jack T; Hashimoto, Dean; Sorensen, Glorian

2013-03-01

The aim of this study was to assess the relationship between psychosocial factors at work and multi-site musculoskeletal pain among patient care workers. In a survey of 1,572 workers from two hospitals, occupational psychosocial factors and health outcomes of workers with single and multi-site pain were evaluated using items from the Job Content Questionnaire that was designed to measure psychological demands, decision latitude, and social support. An adapted Nordic Questionnaire provided data on the musculoskeletal pain outcome. Covariates included body mass index, age, gender, and occupation. The analyses revealed statistically significant associations between psychosocial demands and multi-site musculoskeletal pain among patient care associates, nurses, and administrative personnel, both men and women. Supervisor support played a significant role for nurses and women. These results remained statistically significant after adjusting for covariates. These results highlight the associations between workplace psychosocial strain and multi-site musculoskeletal pain, setting the stage for future longitudinal explorations. Copyright 2013, SLACK Incorporated.

Random-Forest Classification of High-Resolution Remote Sensing Images and Ndsm Over Urban Areas

NASA Astrophysics Data System (ADS)

Sun, X. F.; Lin, X. G.

2017-09-01

As an intermediate step between raw remote sensing data and digital urban maps, remote sensing data classification has been a challenging and long-standing research problem in the community of remote sensing. In this work, an effective classification method is proposed for classifying high-resolution remote sensing data over urban areas. Starting from high resolution multi-spectral images and 3D geometry data, our method proceeds in three main stages: feature extraction, classification, and classified result refinement. First, we extract color, vegetation index and texture features from the multi-spectral image and compute the height, elevation texture and differential morphological profile (DMP) features from the 3D geometry data. Then in the classification stage, multiple random forest (RF) classifiers are trained separately, then combined to form a RF ensemble to estimate each sample's category probabilities. Finally the probabilities along with the feature importance indicator outputted by RF ensemble are used to construct a fully connected conditional random field (FCCRF) graph model, by which the classification results are refined through mean-field based statistical inference. Experiments on the ISPRS Semantic Labeling Contest dataset show that our proposed 3-stage method achieves 86.9% overall accuracy on the test data.

Changes of composition and microstructure of joint interface of tungsten coated carbon by high heat flux

NASA Astrophysics Data System (ADS)

Tokunaga, K.; Matsubara, T.; Miyamoto, Y.; Takao, Y.; Yoshida, N.; Noda, N.; Kubota, Y.; Sogabe, T.; Kato, T.; Plöchl, L.

2000-12-01

Tungsten coatings of 0.5 and 1 mm thickness were successfully deposited by the vacuum plasma spraying (VPS) technique on carbon/carbon fiber composite (CFC), CX-2002U and isotropic fine grained graphite, IG-430U. High heat flux experiments by irradiation of electron beam with uniform profile were performed on the coated samples in order to prove the suitability and load limit of such coating materials. The cross-sectional composition and structure of the interface of VPS-W and carbon material samples were investigated. Compositional analyses showed that the Re/W multi-layer acts as diffusion barrier for carbon and suppresses tungsten carbide formation in the VPS-W layer at high temperature about 1300°C. Microstructure of the joint interface of the sample changed in the case of a peak temperature of about 2800°C. The multi-layer structure completely disappeared and compositional distribution was almost uniform in the interface of the sample after melting and resolidification. The diffusion barrier for carbon is not expected to act in this stage.

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM-2.5

Code of Federal Regulations, 2010 CFR

2010-07-01

... reference method samplers shall be of single-filter design (not multi-filter, sequential sample design... and multiplicative bias (comparative slope and intercept). (1) For each test site, calculate the mean...

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM-2.5

Code of Federal Regulations, 2011 CFR

2011-07-01

... reference method samplers shall be of single-filter design (not multi-filter, sequential sample design... and multiplicative bias (comparative slope and intercept). (1) For each test site, calculate the mean...

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM−2.5.

Code of Federal Regulations, 2012 CFR

2012-07-01

... reference method samplers shall be of single-filter design (not multi-filter, sequential sample design... and multiplicative bias (comparative slope and intercept). (1) For each test site, calculate the mean...

2016 Workplace and Gender Relations Survey of Active Duty Members: Frequently Asked Questions

DTIC Science & Technology

2017-05-01

active duty population both at the sample design stage as well as during the statistical weighting process to account for survey non-response and post...used the OPA sampling design , won the 2011 Policy Impact Award from The American Association for Public Opinion Research (AAPOR), which “recognizes

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

Development and validation of the Chinese version of the Diabetes Management Self-efficacy Scale.

PubMed

Vivienne Wu, Shu-Fang; Courtney, Mary; Edwards, Helen; McDowell, Jan; Shortridge-Baggett, Lillie M; Chang, Pei-Jen

2008-04-01

The purpose of this study was to translate the Diabetes Management Self-Efficacy Scale (DMSES) into Chinese and test the validity and reliability of the instrument within a Taiwanese population. A two-stage design was used for this study. Stage I consisted of a multi-stepped process of forward and backward translation, using focus groups and consensus meetings to translate the 20-item Australia/English version DMSES to Chinese and test content validity. Stage II established the psychometric properties of the Chinese version DMSES (C-DMSES) by examining the criterion, convergent and construct validity, internal consistency and stability testing. The sample for Stage II comprised 230 patients with type 2 diabetes aged 30 years or more from a diabetes outpatient clinic in Taiwan. Three items were modified to better reflect Chinese practice. The C-DMSES obtained a total average CVI score of .86. The convergent validity of the C-DMSES correlated well with the validated measure of the General Self-Efficacy Scale in measuring self-efficacy (r=.55; p<.01). Criterion-related validity showed that the C-DMSES was a significant predictor of the Summary of Diabetes Self-Care Activities scores (Beta=.58; t=10.75, p<.01). Factor analysis supported the C-DMSES being composed of four subscales. Good internal consistency (Cronbach's alpha=.77 to .93) and test-retest reliability (Pearson correlation coefficient r=.86, p<.01) were found. The C-DMSES is a brief and psychometrically sound measure for evaluation of self-efficacy towards management of diabetes by persons with type 2 diabetes in Chinese populations.

Intraherd correlation coefficients and design effects for bovine viral diarrhoea, infectious bovine rhinotracheitis, leptospirosis and neosporosis in cow-calf system herds in North-eastern Mexico.

PubMed

Segura-Correa, J C; Domínguez-Díaz, D; Avalos-Ramírez, R; Argaez-Sosa, J

2010-09-01

Knowledge of the intraherd correlation coefficient (ICC) and design (D) effect for infectious diseases could be of interest in sample size calculation and to provide the correct standard errors of prevalence estimates in cluster or two-stage samplings surveys. Information on 813 animals from 48 non-vaccinated cow-calf herds from North-eastern Mexico was used. The ICC for the bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR), leptospirosis and neosporosis diseases were calculated using a Bayesian approach adjusting for the sensitivity and specificity of the diagnostic tests. The ICC and D values for BVD, IBR, leptospirosis and neosporosis were 0.31 and 5.91, 0.18 and 3.88, 0.22 and 4.53, and 0.11 and 2.68, respectively. The ICC and D values were different from 0 and D greater than 1, therefore large sample sizes are required to obtain the same precision in prevalence estimates than for a random simple sampling design. The report of ICC and D values is of great help in planning and designing two-stage sampling studies. 2010 Elsevier B.V. All rights reserved.

Second stage of Saturn V being assembled with the first stage.

NASA Technical Reports Server (NTRS)

1965-01-01

The hydrogen-powered second stage is being lowered into place during the final phase of fabrication of the Saturn V moon rocket at North American's Seal Beach, California facility. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Electronic Sleep Stage Classifiers: A Survey and VLSI Design Methodology.

PubMed

Kassiri, Hossein; Chemparathy, Aditi; Salam, M Tariqus; Boyce, Richard; Adamantidis, Antoine; Genov, Roman

2017-02-01

First, existing sleep stage classifier sensors and algorithms are reviewed and compared in terms of classification accuracy, level of automation, implementation complexity, invasiveness, and targeted application. Next, the implementation of a miniature microsystem for low-latency automatic sleep stage classification in rodents is presented. The classification algorithm uses one EMG (electromyogram) and two EEG (electroencephalogram) signals as inputs in order to detect REM (rapid eye movement) sleep, and is optimized for low complexity and low power consumption. It is implemented in an on-board low-power FPGA connected to a multi-channel neural recording IC, to achieve low-latency (order of 1 ms or less) classification. Off-line experimental results using pre-recorded signals from nine mice show REM detection sensitivity and specificity of 81.69% and 93.86%, respectively, with the maximum latency of 39 [Formula: see text]. The device is designed to be used in a non-disruptive closed-loop REM sleep suppression microsystem, for future studies of the effects of REM sleep deprivation on memory consolidation.

Uncertainty-Based Multi-Objective Optimization of Groundwater Remediation Design

NASA Astrophysics Data System (ADS)

Singh, A.; Minsker, B.

2003-12-01

Management of groundwater contamination is a cost-intensive undertaking filled with conflicting objectives and substantial uncertainty. A critical source of this uncertainty in groundwater remediation design problems comes from the hydraulic conductivity values for the aquifer, upon which the prediction of flow and transport of contaminants are dependent. For a remediation solution to be reliable in practice it is important that it is robust over the potential error in the model predictions. This work focuses on incorporating such uncertainty within a multi-objective optimization framework, to get reliable as well as Pareto optimal solutions. Previous research has shown that small amounts of sampling within a single-objective genetic algorithm can produce highly reliable solutions. However with multiple objectives the noise can interfere with the basic operations of a multi-objective solver, such as determining non-domination of individuals, diversity preservation, and elitism. This work proposes several approaches to improve the performance of noisy multi-objective solvers. These include a simple averaging approach, taking samples across the population (which we call extended averaging), and a stochastic optimization approach. All the approaches are tested on standard multi-objective benchmark problems and a hypothetical groundwater remediation case-study; the best-performing approach is then tested on a field-scale case at Umatilla Army Depot.

Burden of obstructive lung disease in a rural setting in the Philippines.

PubMed

Idolor, Luisito F; DE Guia, Teresita S; Francisco, Norberto A; Roa, Camilo C; Ayuyao, Fernando G; Tady, Cecil Z; Tan, Daniel T; Banal-Yang, Sylvia; Balanag, Vincent M; Reyes, Maria Teresita N; Dantes, Renato B

2011-10-01

The aim of this study was to determine the prevalence of and risk factors associated with COPD in a rural setting in the Philippines. The study was conducted in two municipalities in Nueva Ecija province in the Philippines. Using the Burden of Obstructive Lung Disease (BOLD) protocol and study design, non-hospitalized men or women, aged 40years or older, were recruited by multi-stage random sampling procedures. Participants completed questionnaires on respiratory symptoms and exposure to potential risk factors for COPD, including smoking, occupation and exposure to burning of biomass fuel. Spirometry was performed according to American Thoracic Society criteria. Of the 1188 individuals selected for recruitment, 722 had acceptable post-bronchodilator spirometry and were classified according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage. The overall prevalence of COPD for all stages was 20.8%. The prevalence of COPD at GOLD Stage I or higher was greater in men compared with women (26.5% vs 15.3%), and increased between the ages of 40 to >70years. Logistic regression analysis showed a significant association between all stages of COPD and farming for >40years (odds ratio (OR) 2.48, 95% confidence interval (CI): 1.43-4.30), use of firewood for cooking for >60years (OR 3.48, 95% CI: 1.57-7.71), a smoking history of ≥20 pack-years (OR 2.86; 95% CI: 1.78-4.60), and a history of tuberculosis (OR 6.31, 95% CI: 2.67-15.0). The prevalence COPD in a rural community in Nueva Ecija, Philippines was 20.8% for GOLD Stage I or higher, and 16.7% for GOLD Stage II or higher. In addition to smoking history, the use of firewood for cooking, working on a farm and a history of tuberculosis were significantly associated with fixed airflow obstruction, as assessed by spirometry. © 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.

Improved estimation of random vibration loads in launch vehicles

NASA Technical Reports Server (NTRS)

Mehta, R.; Erwin, E.; Suryanarayan, S.; Krishna, Murali M. R.

1993-01-01

Random vibration induced load is an important component of the total design load environment for payload and launch vehicle components and their support structures. The current approach to random vibration load estimation is based, particularly at the preliminary design stage, on the use of Miles' equation which assumes a single degree-of-freedom (DOF) system and white noise excitation. This paper examines the implications of the use of multi-DOF system models and response calculation based on numerical integration using the actual excitation spectra for random vibration load estimation. The analytical study presented considers a two-DOF system and brings out the effects of modal mass, damping and frequency ratios on the random vibration load factor. The results indicate that load estimates based on the Miles' equation can be significantly different from the more accurate estimates based on multi-DOF models.

The problems of designing a multifunctional courtyard space of high-rise buildings by the example of residential development in Volgograd

NASA Astrophysics Data System (ADS)

Matovnikov, Sergei; Matovnikova, Natalia; Samoylenko, Polina

2018-03-01

The paper considers the issues of designing a modern courtyard space for high-rise buildings in Volgograd to obtain a multifunctional environment through the arrangement of new recreational territories and the search of innovative planning methods for urban landscape design. In professionals' opinion, the problem concerning the design and construction of recreational zones and greenery planting is very acute for Volgograd, such territories are often absent in many districts of the city. Generally, the decrease in the natural component and a low level of recreational territories improvement are typical for Volgograd. In addition, the problem of designing a modern urban courtyard space for high-rise buildings to obtain a multi-functional environment exists and requires a thorough investigation. The question is if there is a possibility to solve these difficult tasks by means of local design methods only or whether there should be a complex approach at the stage of the formation of master plans for modern residential areas and which modern design methods can ensure the creation of a courtyard space as a multi-functional environment. These questions as well as some other ones will be the topic of our paper.

Semi-automated high-efficiency reflectivity chamber for vacuum UV measurements

NASA Astrophysics Data System (ADS)

Wiley, James; Fleming, Brian; Renninger, Nicholas; Egan, Arika

2017-08-01

This paper presents the design and theory of operation for a semi-automated reflectivity chamber for ultraviolet optimized optics. A graphical user interface designed in LabVIEW controls the stages, interfaces with the detector system, takes semi-autonomous measurements, and monitors the system in case of error. Samples and an optical photodiode sit on an optics plate mounted to a rotation stage in the middle of the vacuum chamber. The optics plate rotates the samples and diode between an incident and reflected position to measure the absolute reflectivity of the samples at wavelengths limited by the monochromator operational bandpass of 70 nm to 550 nm. A collimating parabolic mirror on a fine steering tip-tilt motor enables beam steering for detector peak-ups. This chamber is designed to take measurements rapidly and with minimal oversight, increasing lab efficiency for high cadence and high accuracy vacuum UV reflectivity measurements.

Nonlinearity-aware based dimensionality reduction and over-sampling for AD/MCI classification from MRI measures.

PubMed

Cao, Peng; Liu, Xiaoli; Yang, Jinzhu; Zhao, Dazhe; Huang, Min; Zhang, Jian; Zaiane, Osmar

2017-12-01

Alzheimer's disease (AD) has been not only a substantial financial burden to the health care system but also an emotional burden to patients and their families. Making accurate diagnosis of AD based on brain magnetic resonance imaging (MRI) is becoming more and more critical and emphasized at the earliest stages. However, the high dimensionality and imbalanced data issues are two major challenges in the study of computer aided AD diagnosis. The greatest limitations of existing dimensionality reduction and over-sampling methods are that they assume a linear relationship between the MRI features (predictor) and the disease status (response). To better capture the complicated but more flexible relationship, we propose a multi-kernel based dimensionality reduction and over-sampling approaches. We combined Marginal Fisher Analysis with ℓ 2,1 -norm based multi-kernel learning (MKMFA) to achieve the sparsity of region-of-interest (ROI), which leads to simultaneously selecting a subset of the relevant brain regions and learning a dimensionality transformation. Meanwhile, a multi-kernel over-sampling (MKOS) was developed to generate synthetic instances in the optimal kernel space induced by MKMFA, so as to compensate for the class imbalanced distribution. We comprehensively evaluate the proposed models for the diagnostic classification (binary class and multi-class classification) including all subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. The experimental results not only demonstrate the proposed method has superior performance over multiple comparable methods, but also identifies relevant imaging biomarkers that are consistent with prior medical knowledge. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adolescent Experiences with the Vaginal Ring

PubMed Central

Epstein, Laura B.; Sokal-Gutierrez, Karen; Ivey, Susan L.; Raine, Tina; Auerswald, Colette

2011-01-01

Purpose To understand racial/ethnic minority adolescent females’ experiences with the vaginal ring. Methods We conducted in-depth interviews with a clinic-based sample of 32 young women aged 15–24 years who had used the vaginal ring. Results Qualitative analysis using grounded theory revealed that adolescents undergo a multi-stage process when trying the ring and adopting ring use. These stages include hearing about the ring, initial reactions, first experiences with insertion and removal, and first sexual experiences. Adolescents subsequently enter an assessment and adjustment stage in which they decide whether to adopt or discontinue ring use. Ultimately they share their experiences with friends. Conclusions The model developed provides a context within which providers may advise adolescents as they begin use of the ring. Some specific recommendations are offered. PMID:18565439

Low cost light-sheet microscopy for whole brain imaging

NASA Astrophysics Data System (ADS)

Kumar, Manish; Nasenbeny, Jordan; Kozorovitskiy, Yevgenia

2018-02-01

Light-sheet microscopy has evolved as an indispensable tool in imaging biological samples. It can image 3D samples at fast speed, with high-resolution optical sectioning, and with reduced photobleaching effects. These properties make light-sheet microscopy ideal for imaging fluorophores in a variety of biological samples and organisms, e.g. zebrafish, drosophila, cleared mouse brains, etc. While most commercial turnkey light-sheet systems are expensive, the existing lower cost implementations, e.g. OpenSPIM, are focused on achieving high-resolution imaging of small samples or organisms like zebrafish. In this work, we substantially reduce the cost of light-sheet microscope system while targeting to image much larger samples, i.e. cleared mouse brains, at single-cell resolution. The expensive components of a lightsheet system - excitation laser, water-immersion objectives, and translation stage - are replaced with an incoherent laser diode, dry objectives, and a custom-built Arduino-controlled translation stage. A low-cost CUBIC protocol is used to clear fixed mouse brain samples. The open-source platforms of μManager and Fiji support image acquisition, processing, and visualization. Our system can easily be extended to multi-color light-sheet microscopy.

P38 mitogen-activated protein kinase (p38 MAPK) overexpression in clinical staging of nasopharyngeal carcinoma

NASA Astrophysics Data System (ADS)

Farhat; Asnir, R. A.; Yudhistira, A.; Daulay, E. R.; Muzakkir, M. M.; Yulius, S.

2018-03-01

Molecular biological research on nasopharyngeal carcinoma has been widely practiced, such as VEGF, EGFR, COX-2 expression and so on. MAPK plays a role in cell growth such as proliferation, differentiation, and apoptosis, primarily contributing to gene expression, where p38 MAPK pathway mostly associate with anti-apoptosis and cause cell transformation. The aim of this study is to determine the expression of p38 MAPK in clinical stage of nasopharyngeal carcinoma so that the result can be helpful in prognosis and adjunctive therapy in nasopharyngeal carcinoma. The research design is descriptive. It was done in THT- KL Department of FK USU/RSUP Haji Adam Malik, Medan and Pathology Anatomical Department of FK USU. The study was conducted from December 2011 to May 2012. The Samples are all patients who diagnosed with nasopharyngeal carcinoma in oncology division of Otorhinolaryngology Department. p38 MAPK overexpression was found in 21 samples (70%) from 30 nasopharyngeal carcinoma samples. The elevated of p38 MAPK expression most found on T4 by eight samples (38.1%), N3 lymph node group by nine samples (42.9%), stage IV of clinical staging is as many as 15 samples (71.4%). p38 MAPK most expressed in stage IV clinical staging of patients with nasopharyngeal carcinoma.

BLIND ordering of large-scale transcriptomic developmental timecourses.

PubMed

Anavy, Leon; Levin, Michal; Khair, Sally; Nakanishi, Nagayasu; Fernandez-Valverde, Selene L; Degnan, Bernard M; Yanai, Itai

2014-03-01

RNA-Seq enables the efficient transcriptome sequencing of many samples from small amounts of material, but the analysis of these data remains challenging. In particular, in developmental studies, RNA-Seq is challenged by the morphological staging of samples, such as embryos, since these often lack clear markers at any particular stage. In such cases, the automatic identification of the stage of a sample would enable previously infeasible experimental designs. Here we present the 'basic linear index determination of transcriptomes' (BLIND) method for ordering samples comprising different developmental stages. The method is an implementation of a traveling salesman algorithm to order the transcriptomes according to their inter-relationships as defined by principal components analysis. To establish the direction of the ordered samples, we show that an appropriate indicator is the entropy of transcriptomic gene expression levels, which increases over developmental time. Using BLIND, we correctly recover the annotated order of previously published embryonic transcriptomic timecourses for frog, mosquito, fly and zebrafish. We further demonstrate the efficacy of BLIND by collecting 59 embryos of the sponge Amphimedon queenslandica and ordering their transcriptomes according to developmental stage. BLIND is thus useful in establishing the temporal order of samples within large datasets and is of particular relevance to the study of organisms with asynchronous development and when morphological staging is difficult.

Multidisciplinary Modeling Software for Analysis, Design, and Optimization of HRRLS Vehicles

NASA Technical Reports Server (NTRS)

Spradley, Lawrence W.; Lohner, Rainald; Hunt, James L.

2011-01-01

The concept for Highly Reliable Reusable Launch Systems (HRRLS) under the NASA Hypersonics project is a two-stage-to-orbit, horizontal-take-off / horizontal-landing, (HTHL) architecture with an air-breathing first stage. The first stage vehicle is a slender body with an air-breathing propulsion system that is highly integrated with the airframe. The light weight slender body will deflect significantly during flight. This global deflection affects the flow over the vehicle and into the engine and thus the loads and moments on the vehicle. High-fidelity multi-disciplinary analyses that accounts for these fluid-structures-thermal interactions are required to accurately predict the vehicle loads and resultant response. These predictions of vehicle response to multi physics loads, calculated with fluid-structural-thermal interaction, are required in order to optimize the vehicle design over its full operating range. This contract with ResearchSouth addresses one of the primary objectives of the Vehicle Technology Integration (VTI) discipline: the development of high-fidelity multi-disciplinary analysis and optimization methods and tools for HRRLS vehicles. The primary goal of this effort is the development of an integrated software system that can be used for full-vehicle optimization. This goal was accomplished by: 1) integrating the master code, FEMAP, into the multidiscipline software network to direct the coupling to assure accurate fluid-structure-thermal interaction solutions; 2) loosely-coupling the Euler flow solver FEFLO to the available and proven aeroelasticity and large deformation (FEAP) code; 3) providing a coupled Euler-boundary layer capability for rapid viscous flow simulation; 4) developing and implementing improved Euler/RANS algorithms into the FEFLO CFD code to provide accurate shock capturing, skin friction, and heat-transfer predictions for HRRLS vehicles in hypersonic flow, 5) performing a Reynolds-averaged Navier-Stokes computation on an HRRLS configuration; 6) integrating the RANS solver with the FEAP code for coupled fluid-structure-thermal capability; and 7) integrating the existing NASA SRGULL propulsion flow path prediction software with the FEFLO software for quasi-3D propulsion flow path predictions, 8) improving and integrating into the network, an existing adjoint-based design optimization code.

Assessing the Validity of a Stage Measure on Physical Activity in a Population-Based Sample of Individuals with Type 1 or Type 2 Diabetes

ERIC Educational Resources Information Center

Plotnikoff, Ronald C.; Lippke, Sonia; Reinbold-Matthews, Melissa; Courneya, Kerry S.; Karunamuni, Nandini; Sigal, Ronald J.; Birkett, Nicholas

2007-01-01

This study was designed to test the validity of a transtheoretical model's physical activity (PA) stage measure with intention and different intensities of behavior in a large population-based sample of adults living with diabetes (Type 1 diabetes, n = 697; Type 2 diabetes, n = 1,614) and examine different age groups. The overall…

A coaxial-output capacitor-loaded annular pulse forming line.

PubMed

Li, Rui; Li, Yongdong; Su, Jiancang; Yu, Binxiong; Xu, Xiudong; Zhao, Liang; Cheng, Jie; Zeng, Bo

2018-04-01

A coaxial-output capacitor-loaded annular pulse forming line (PFL) is developed in order to reduce the flat top fluctuation amplitude of the forming quasi-square pulse and improve the quality of the pulse waveform produced by a Tesla-pulse forming network (PFN) type pulse generator. A single module composed of three involute dual-plate PFNs is designed, with a characteristic impedance of 2.44 Ω, an electrical length of 15 ns, and a sustaining voltage of 60 kV. The three involute dual-plate PFNs connected in parallel have the same impedance and electrical length. Due to the existed small inductance and capacitance per unit length in each involute dual-plate PFN, the upper cut-off frequency of the PFN is increased. As a result, the entire annular PFL has better high-frequency response capability. Meanwhile, the three dual-plate PFNs discharge in parallel, which is much closer to the coaxial output. The series connecting inductance between adjacent two modules is significantly reduced when the annular PFL modules are connected in series. The pulse waveform distortion is reduced when the pulse transfers along the modules. Finally, the shielding electrode structure is applied on both sides of the module. The electromagnetic field is restricted in the module when a single module discharges, and the electromagnetic coupling between the multi-stage annular PFLs is eliminated. Based on the principle of impedance matching between the multi-stage annular PFL and the coaxial PFL, the structural optimization design of a mixed PFL in a Tesla type pulse generator is completed with the transient field-circuit co-simulation method. The multi-stage annular PFL consists of 18 stage annular PFL modules in series, with the characteristic impedance of 44 Ω, the electrical length of 15 ns, and the sustaining voltage of 1 MV. The mixed PFL can generate quasi-square electrical pulses with a pulse width of 43 ns, and the fluctuation ratio of the pulse flat top is less than 8% when the pulse rise time is about 5 ns.

A coaxial-output capacitor-loaded annular pulse forming line

NASA Astrophysics Data System (ADS)

Li, Rui; Li, Yongdong; Su, Jiancang; Yu, Binxiong; Xu, Xiudong; Zhao, Liang; Cheng, Jie; Zeng, Bo

2018-04-01

A coaxial-output capacitor-loaded annular pulse forming line (PFL) is developed in order to reduce the flat top fluctuation amplitude of the forming quasi-square pulse and improve the quality of the pulse waveform produced by a Tesla-pulse forming network (PFN) type pulse generator. A single module composed of three involute dual-plate PFNs is designed, with a characteristic impedance of 2.44 Ω, an electrical length of 15 ns, and a sustaining voltage of 60 kV. The three involute dual-plate PFNs connected in parallel have the same impedance and electrical length. Due to the existed small inductance and capacitance per unit length in each involute dual-plate PFN, the upper cut-off frequency of the PFN is increased. As a result, the entire annular PFL has better high-frequency response capability. Meanwhile, the three dual-plate PFNs discharge in parallel, which is much closer to the coaxial output. The series connecting inductance between adjacent two modules is significantly reduced when the annular PFL modules are connected in series. The pulse waveform distortion is reduced when the pulse transfers along the modules. Finally, the shielding electrode structure is applied on both sides of the module. The electromagnetic field is restricted in the module when a single module discharges, and the electromagnetic coupling between the multi-stage annular PFLs is eliminated. Based on the principle of impedance matching between the multi-stage annular PFL and the coaxial PFL, the structural optimization design of a mixed PFL in a Tesla type pulse generator is completed with the transient field-circuit co-simulation method. The multi-stage annular PFL consists of 18 stage annular PFL modules in series, with the characteristic impedance of 44 Ω, the electrical length of 15 ns, and the sustaining voltage of 1 MV. The mixed PFL can generate quasi-square electrical pulses with a pulse width of 43 ns, and the fluctuation ratio of the pulse flat top is less than 8% when the pulse rise time is about 5 ns.

Stackable differential mobility analyzer for aerosol measurement

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

Cheng, Meng-Dawn; Chen, Da-Ren

2007-05-08

A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for chargingmore » to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.« less

An Overview of NASA's Integrated Design and Engineering Analysis (IDEA) Environment

NASA Technical Reports Server (NTRS)

Robinson, Jeffrey S.

2011-01-01

Historically, the design of subsonic and supersonic aircraft has been divided into separate technical disciplines (such as propulsion, aerodynamics and structures), each of which performs design and analysis in relative isolation from others. This is possible, in most cases, either because the amount of interdisciplinary coupling is minimal, or because the interactions can be treated as linear. The design of hypersonic airbreathing vehicles, like NASA's X-43, is quite the opposite. Such systems are dominated by strong non-linear interactions between disciplines. The design of these systems demands that a multi-disciplinary approach be taken. Furthermore, increased analytical fidelity at the conceptual design phase is highly desirable, as many of the non-linearities are not captured by lower fidelity tools. Only when these systems are designed from a true multi-disciplinary perspective, can the real performance benefits be achieved and complete vehicle systems be fielded. Toward this end, the Vehicle Analysis Branch at NASA Langley Research Center has been developing the Integrated Design and Engineering Analysis (IDEA) Environment. IDEA is a collaborative environment for parametrically modeling conceptual and preliminary designs for launch vehicle and high speed atmospheric flight configurations using the Adaptive Modeling Language (AML) as the underlying framework. The environment integrates geometry, packaging, propulsion, trajectory, aerodynamics, aerothermodynamics, engine and airframe subsystem design, thermal and structural analysis, and vehicle closure into a generative, parametric, unified computational model where data is shared seamlessly between the different disciplines. Plans are also in place to incorporate life cycle analysis tools into the environment which will estimate vehicle operability, reliability and cost. IDEA is currently being funded by NASA?s Hypersonics Project, a part of the Fundamental Aeronautics Program within the Aeronautics Research Mission Directorate. The environment is currently focused around a two-stage-to-orbit configuration with a turbine-based combined cycle (TBCC) first stage and a reusable rocket second stage. IDEA will be rolled out in generations, with each successive generation providing a significant increase in capability, either through increased analytic fidelity, expansion of vehicle classes considered, or by the inclusion of advanced modeling techniques. This paper provides the motivation behind the current effort, an overview of the development of the IDEA environment (including the contents and capabilities to be included in Generation 1 and Generation 2), and a description of the current status and detail of future plans.

Multi-Level Factors Affecting Entry into and Engagement in the HIV Continuum of Care in Iringa, Tanzania

PubMed Central

Layer, Erica H.; Kennedy, Caitlin E.; Beckham, Sarah W.; Mbwambo, Jessie K.; Likindikoki, Samuel; Davis, Wendy W.; Kerrigan, Deanna L.; Brahmbhatt, Heena

2014-01-01

Progression through the HIV continuum of care, from HIV testing to lifelong retention in antiretroviral therapy (ART) care and treatment programs, is critical to the success of HIV treatment and prevention efforts. However, significant losses occur at each stage of the continuum and little is known about contextual factors contributing to disengagement at these stages. This study sought to explore multi-level barriers and facilitators influencing entry into and engagement in the continuum of care in Iringa, Tanzania. We used a mixed-methods study design including facility-based assessments and interviews with providers and clients of HIV testing and treatment services; interviews, focus group discussions and observations with community-based providers and clients of HIV care and support services; and longitudinal interviews with men and women living with HIV to understand their trajectories in care. Data were analyzed using narrative analysis to identify key themes across levels and stages in the continuum of care. Participants identified multiple compounding barriers to progression through the continuum of care at the individual, facility, community and structural levels. Key barriers included the reluctance to engage in HIV services while healthy, rigid clinic policies, disrespectful treatment from service providers, stock-outs of supplies, stigma and discrimination, alternate healing systems, distance to health facilities and poverty. Social support from family, friends or support groups, home-based care providers, income generating opportunities and community mobilization activities facilitated engagement throughout the HIV continuum. Findings highlight the complex, multi-dimensional dynamics that individuals experience throughout the continuum of care and underscore the importance of a holistic and multi-level perspective to understand this process. Addressing barriers at each level is important to promoting increased engagement throughout the continuum. PMID:25119665

Third Stage (S-IVB) At KSC

NASA Technical Reports Server (NTRS)

1960-01-01

A NASA technician is dwarfed by the gigantic Third Stage (S-IVB) as it rests on supports in a facility at KSC. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Second Stage (S-II) Plays Key Role in Apollo missions

NASA Technical Reports Server (NTRS)

1970-01-01

This photograph of the Saturn V Second Stage (S-II) clearly shows the cluster of five powerful J-2 engines needed to boost the Apollo spacecraft into earth orbit following first stage separation. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

[Potential of Information and Communications Technology to Improve Intersectoral Processes of Care: A Case Study of the Specialised Outpatient Palliative Care].

PubMed

Meyer-Delpho, C; Schubert, H-J

2015-09-01

The added value of information and communications technologies should be demonstrated precisely in such areas of care in which the importance of intersectoral and interdisciplinary cooperation is particularly high. In the context of the accompanying research of a supply concept for palliative care patients, the potential of a digital documentation process was comparatively analysed with the conventional paper-based workflow. Data were collected in the form of a multi-methodological approach and processed for the project in 3 stages: (1) Development and analysis of a palliative care process with the focus on all relevant steps of documentation. (2) Questionnaire design and the comparative mapping of specific process times. (3) Sampling, selection, and analysis of patient records and their derivable insights of process iterations. With the use of ICT, the treatment time per patient is reduced by up to 53% and achieves a reduction in costs and workload by up to 901 min. The result of an up to 213% increase in the number of patient contacts allows a higher continuity of care. Although the 16% increase in documentation loyalty improves the usability of cross-team documented information, it partially extends the workload on the level of individual actors. By using a digital health record around 31% more patients could be treated with the same staffing ratio. The multi-stage analysis of the palliative care process showed that ICT has a decisive influence on the process dimension of intersectoral cooperation. Due to favourable organisational conditions the pioneering work of palliative care also provides important guidance for a successful use of ICT technologies in the context of innovative forms of care. © Georg Thieme Verlag KG Stuttgart · New York.

The experimental set-up of the RIB in-flight facility EXOTIC

NASA Astrophysics Data System (ADS)

Pierroutsakou, D.; Boiano, A.; Boiano, C.; Di Meo, P.; La Commara, M.; Manea, C.; Mazzocco, M.; Nicoletto, M.; Parascandolo, C.; Signorini, C.; Soramel, F.; Strano, E.; Toniolo, N.; Torresi, D.; Tortone, G.; Anastasio, A.; Bettini, M.; Cassese, C.; Castellani, L.; Corti, D.; Costa, L.; De Fazio, B.; Galet, G.; Glodariu, T.; Grebosz, J.; Guglielmetti, A.; Molini, P.; Pontoriere, G.; Rocco, R.; Romoli, M.; Roscilli, L.; Sandoli, M.; Stroe, L.; Tessaro, M.; Zatti, P. G.

2016-10-01

We describe the experimental set-up of the Radioactive Ion Beam (RIB) in-flight facility EXOTIC consisting of: (a) two position-sensitive Parallel Plate Avalanche Counters (PPACs), dedicated to the event-by-event tracking of the produced RIBs and to time of flight measurements and (b) the new high-granularity compact telescope array EXPADES (EXotic PArticle DEtection System), designed for nuclear physics and nuclear astrophysics experiments employing low-energy light RIBs. EXPADES consists of eight ΔE -Eres telescopes arranged in a cylindrical configuration around the target. Each telescope is made up of two Double Sided Silicon Strip Detectors (DSSSDs) with a thickness of 40/60 μm and 300 μm for the ΔE and Eres layer, respectively. Additionally, eight ionization chambers were constructed to be used as an alternative ΔE stage or, in conjunction with the entire DSSSD array, to build up more complex triple telescopes. New low-noise multi-channel charge-sensitive preamplifiers and spectroscopy amplifiers, associated with constant fraction discriminators, peak-and-hold and Time to Amplitude Converter circuits were developed for the electronic readout of the ΔE stage. Application Specific Integrated Circuit-based electronics was employed for the treatment of the Eres signals. An 8-channel, 12-bit multi-sampling 50 MHz Analog to Digital Converter, a Trigger Supervisor Board for handling the trigger signals of the whole experimental set-up and an ad hoc data acquisition system were also developed. The performance of the PPACs, EXPADES and of the associated electronics was obtained offline with standard α calibration sources and in-beam by measuring the scattering process for the systems 17O+58Ni and 17O+208Pb at incident energies around their respective Coulomb barriers and, successively, during the first experimental runs with the RIBs of the EXOTIC facility.

The feasibility study of 177Lu production in Miniature Neutron Source Reactors using a multi-stage approach in Isfahan, Iran.

PubMed

Golabian, A; Hosseini, M A; Ahmadi, M; Soleimani, B; Rezvanifard, M

2018-01-01

Miniature neutron source reactors (MNSRs) are among the safest and economic research reactors with potentials to be used for neutron studies. This manuscript explores the feasibility of 177 Lu production in Isfahan MNSR reactor using direct production route. In this study, to assess the specific activity of the produced radioisotope, a simulation was carried out through the MCNPX2.6 code. The simulation was validated by irradiating a lutetium disc-like (99.98 chemical purity) at the thermal neutron flux of 5 × 10 11 ncm 2 s -1 and an irradiation time of 4min. After the spectrometry of the irradiated sample, the experimental results of 177 Lu production were compared with the simulation results. In addition, factor from the simulation was extracted by replacing it in the related equations in order to calculate specific activity through a multi-stage approach, and by using different irradiation techniques. The results showed that the simulation technique designed in this study is in agreement with the experimental approach (with a difference of approximately 3%). It was also found that the maximum 177 Lu production at the maximum flux and irradiation time allows access to 723.5mCi/g after 27 cycles. Furthermore, the comparison of irradiation techniques showed that increasing the irradiation time is more effective in 177 Lu production efficiency than increasing the number of irradiation cycles. In a way that increasing the irradiation time would postpone the saturation of the productions. On the other hand, it was shown that the choice of an appropriate irradiation technique for 177 Lu production can be economically important in term of the effective fuel consumption in the reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

A method for measuring the local gas pressure within a gas-flow stage in situ in the transmission electron microscope

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

Colby, Robert J.; Alsem, Daan H.; Liyu, Andrey V.

2015-06-01

The development of environmental transmission electron microscopy (TEM) has enabled in situ experiments in a gaseous environment with high resolution imaging and spectroscopy. Addressing scientific challenges in areas such as catalysis, corrosion, and geochemistry can require pressures much higher than the ~20 mbar achievable with a differentially pumped, dedicated environmental TEM. Gas flow stages, in which the environment is contained between two semi-transparent thin membrane windows, have been demonstrated at pressures of several atmospheres. While this constitutes significant progress towards operando measurements, the design of many current gas flow stages is such that the pressure at the sample cannot necessarilymore » be directly inferred from the pressure differential across the system. Small differences in the setup and design of the gas flow stage can lead to very different sample pressures. We demonstrate a method for measuring the gas pressure directly, using a combination of electron energy loss spectroscopy and TEM imaging. This method requires only two energy filtered TEM images, limiting the measurement time to a few seconds and can be performed during an ongoing experiment at the region of interest. This approach provides a means to ensure reproducibility between different experiments, and even between very differently designed gas flow stages.« less

A voltage-division-type low-jitter self-triggered repetition-rate switch.

PubMed

Su, Jian-Cang; Zeng, Bo; Gao, Peng-Cheng; Li, Rui; Wu, Xiao-Long; Zhao, Liang

2016-10-01

A voltage-division-type (V/N) low-jitter self-triggered multi-stage switch is put forward. It comprises of a triggered corona gap, several quasi-uniform-field gaps, and an inversion inductor. When the corona gap is in the stage of self-breakdown, the multi-stage gaps are triggered and the switch is closed via an over-voltage. This type of V/N switch has the advantage of compact structure since the auxiliary components like the gas-blowing system and the triggered system are eliminated from the whole system. It also has advantages such as low breakdown jitter and high energy efficiency. The dependence of the self-triggered voltage on the over-voltage factor and the switch operating voltage is deduced. A switch of this type is designed and fabricated and experiments to research its characteristics are conducted. The results show that this switch can operate on a voltage of 1 MV at 50 Hz and can generate 1000 successive pulses with a jitter as low as 3% and an energy efficiency as high as 90%. This V/N switch can work under a high repetition rate with a long lifetime.

The STAMPEDE trial: paradigm-changing data through innovative trial design.

PubMed

Carthon, Bradley C; Antonarakis, Emmanuel S

2016-09-01

Despite the numerous regulatory approvals for prostate cancer, metastatic prostate cancer remains a huge burden for men worldwide. In an exciting development, James et al . recently published data from the Systemic Therapy in Advanced or Metastatic Prostate Cancer: Evaluation of Drug Efficacy: a multi-stage multi-arm randomised control trial (STAMPEDE). This is an innovative multi-arm multi-stage (MAMS) trial that has utilized one control arm and several comparator arms in order to provide evidence for the inclusion of therapies beyond standard androgen deprivation alone. The patient population included: (I) men with high-risk, non-metastatic, node-negative disease; (II) men with distant-metastatic or node-positive disease; and (III) men with previously-treated prostate cancer by prostatectomy or definitive radiotherapy presenting with relapse. Men were to continue androgen deprivation for at least 2 years. The current data published by this group supports earlier results and provides additional evidence that docetaxel utilized in an up-front fashion provides a survival benefit in men with hormone-sensitive metastatic prostate cancer. Moreover, the initial results from STAMPEDE show how therapies without a demonstrated survival benefit can be efficiently excluded from further study once the likelihood of a benefit is ruled out by a predetermined analysis. In this piece, we will review the STAMPEDE data, contrast it with existing results, and provide our perspectives on how this will affect future trial conduct in the field of prostate cancer.

Geolab 2010: Desert Rats Field Demonstration

NASA Technical Reports Server (NTRS)

Evans, Cindy A.; Calaway, M. J.; Bell, M. S.

2009-01-01

In 2010, Desert Research and Technology Studies (Desert RATS), NASA's annual field exercise designed to test spacesuit and rover technologies, will include a first generation lunar habitat facility, the Habitat Demonstration Unit (HDU). The habitat will participate in joint operations in northern Arizona with the Lunar Electric Rover (LER) and will be used as a multi-use laboratory and working space. A Geology Laboratory or GeoLab is included in the HDU design. Historically, science participation in Desert RATS exercises has supported the technology demonstrations with geological traverse activities that are consistent with preliminary concepts for lunar surface science Extravehicular Activities (EVAs). Next year s HDU demonstration is a starting point to guide the development of requirements for the Lunar Surface Systems Program and test initial operational concepts for an early lunar excursion habitat that would follow geological traverses along with the LER. For the GeoLab, these objectives are specifically applied to support future geological surface science activities. The goal of our GeoLab is to enhance geological science returns with the infrastructure that supports preliminary examination, early analytical characterization of key samples, and high-grading lunar samples for return to Earth [1, 2] . Figure 1: Inside view schematic of the GeoLab a 1/8 section of the HDU, including a glovebox for handling and examining geological samples. Other outfitting facilities are not depicted in this figure. GeoLab Description: The centerpiece of the GeoLab is a glovebox, allowing for samples to be brought into the habitat in a protected environment for preliminary examination (see Fig. 1). The glovebox will be attached to the habitat bulkhead and contain three sample pass-through antechambers that would allow direct transfer of samples from outside the HDU to inside the glovebox. We will evaluate the need for redundant chambers, and other uses for the glovebox antechambers, such as a staging area for additional tools or samples. The sides of the glovebox are designed with instrument ports and additional smaller ports for cable pass-through, imagery feeds and environmental monitoring. This first glovebox version will be equipped with basic tools for manipulating, viewing, and early analysis of samples. The GeoLab was also designed for testing additional analytical instruments in a field setting.

Multi-stage mixing in subduction zone: Application to Merapi volcano, Indonesia

NASA Astrophysics Data System (ADS)

Debaille, V.; Doucelance, R.; Weis, D.; Schiano, P.

2003-04-01

Basalts sampling subduction zone volcanism (IAB) often show binary mixing relationship in classical Sr-Nd, Pb-Pb, Sr-Pb isotopic diagrams, generally interpreted as reflecting the involvement of two components in their source. However, several authors have highlighted the presence of minimum three components in such a geodynamical context: mantle wedge, subducted and altered oceanic crust and subducted sediments. The overlying continental crust can also contribute by contamination and assimilation in magma chambers and/or during magma ascent. Here we present a multi-stage model to obtain a two end-member mixing from three components (mantle wedge, altered oceanic crust and sediments). The first stage of the model considers the metasomatism of the mantle wedge by fluids and/or melts released by subducted materials (altered oceanic crust and associated sediments), considering mobility and partition coefficient of trace elements in hydrated fluids and silicate melts. This results in the generation of two distinct end-members, reducing the number of components (mantle wedge, oceanic crust, sediments) from three to two. The second stage of the model concerns the binary mixing of the two end-members thus defined: mantle wedge metasomatized by slab-derived fluids and mantle wedge metasomatized by sediment-derived fluids. This model has been applied on a new isotopic data set (Sr, Nd and Pb, analyzed by TIMS and MC-ICP-MS) of Merapi volcano (Java island, Indonesia). Previous studies have suggested three distinct components in the source of indonesian lavas: mantle wedge, subducted sediments and altered oceanic crust. Moreover, it has been shown that crustal contamination does not significantly affect isotopic ratios of lavas. The multi-stage model proposed here is able to reproduce the binary mixing observed in lavas of Merapi, and a set of numerical values of bulk partition coefficient is given that accounts for the genesis of lavas.

Application of the theory of reasoned action to promoting breakfast consumption

PubMed Central

Hosseini, Zahra; Gharlipour Gharghani, Zabihollah; Mansoori, Anahita; Aghamolaei, Teamur; Mohammadi Nasrabadi, Maryam

2015-01-01

Background: Breakfast is the most important daily meal, but neglected more than other meals by children and adolescents. The aim of this study was to evaluate the effectiveness of an educational intervention, based on the Theory of Reasoned Action (TRA) to increase breakfast consumption among school children in Bandar Abbas, Iran. Methods: In this quasi experimental study which was conducted in 2012, 88 students of four secondary schools in Bandar Abbas, south of Iran, were enrolled. Multi-stage cluster sampling was performed with random allocation of interventional and control groups. The study tool was a questionnaire which was filled by the students before and two months after the educational intervention. For data analysis, statistical tests including paired-samples t-test, independent samples t-test, Wilcoxon test, and Mann-Whitney test were used through SPSS v.18 software. Results: The result of the study showed that application of TRA significantly increased scores of behavior of breakfast consumption (p<0.01). After the intervention, a significant increase was revealed in all nutrition intakes, except for fat and sugar (p<0.01). Conclusion: The findings support application of the TRA in improving the intention and behavior of breakfast consumption. Applying this theory for designing interventions to increase breakfast eating is recommended. PMID:26913252

Variable Circumstellar Disks of “Classical” Be Stars

NASA Astrophysics Data System (ADS)

Gerhartz, Cody; Bjorkman, K. S.; Wisniewski, J. P.

2013-06-01

Circumstellar disks are common among many stars, all spectral types, and at different stages of their lifetimes. Among the near-main sequence “Classical” Be stars, there is growing evidence that these disks can form, dissipate, and reform, on timescales that are differ from case to case. We present data for a subset of cases where observations have been obtained throughout the different phases of the disk cycle. Using data obtained with the SpeX instrument at the NASA IRTF, we examine the IR spectral line variability of these stars to better understand the timescales and the physical mechanisms involved. The primary focus in this study are the V/R variations that are observed in the sample. The second stage of our project is to examine a sample of star clusters known to contain Be stars, with the goal to develop a more statistically significant sample of variable circumstellar disk systems. With a robust multi-epoch study we can determine whether these Be stars exhibit disk-loss or disk-renewal phases. The larger sample will enable a better understanding of the prevalence of these disk events.

Technical Report and Data File User's Manual for the 1992 National Adult Literacy Survey.

ERIC Educational Resources Information Center

Kirsch, Irwin; Yamamoto, Kentaro; Norris, Norma; Rock, Donald; Jungeblut, Ann; O'Reilly, Patricia; Berlin, Martha; Mohadjer, Leyla; Waksberg, Joseph; Goksel, Huseyin; Burke, John; Rieger, Susan; Green, James; Klein, Merle; Campbell, Anne; Jenkins, Lynn; Kolstad, Andrew; Mosenthal, Peter; Baldi, Stephane

Chapter 1 of this report and user's manual describes design and implementation of the 1992 National Adult Literacy Survey (NALS). Chapter 2 reviews stages of sampling for national and state survey components; presents weighted and unweighted response rates for the household component; and describes non-incentive and prison sample designs. Chapter…

Analysis of non-enzymatically glycated peptides: neutral-loss-triggered MS3 versus multi-stage activation tandem mass spectrometry

PubMed Central

Zhang, Qibin; Petyuk, Vladislav A.; Schepmoes, Athena A.; Orton, Daniel J.; Monroe, Matthew E.; Yang, Feng; Smith, Richard D.; Metz, Thomas O.

2009-01-01

Non-enzymatic glycation of tissue proteins has important implications in the development of complications of diabetes mellitus. While electron transfer dissociation (ETD) has been shown to outperform collision-induced dissociation (CID) in sequencing glycated peptides by tandem mass spectrometry, ETD instrumentation is not yet widely available and often suffers from significantly lower sensitivity than CID. In this study, we evaluated different advanced CID techniques (i.e., neutral-loss-triggered MS3 and multi-stage activation) during liquid chromatography/multi-stage mass spectrometric (LC/MSn) analyses of Amadori-modified peptides enriched from human serum glycated in vitro. During neutral-loss-triggered MS3 experiments, MS3 scans triggered by neutral losses of 3 H2O or 3 H2O + HCHO produced similar results in terms of glycated peptide identifications. However, neutral losses of 3 H2O resulted in significantly more glycated peptide identifications during multi-stage activation experiments. Overall, the multi-stage activation approach produced more glycated peptide identifications, while the neutral-loss-triggered MS3 approach resulted in much higher specificity. Both techniques are viable alternatives to ETD for identifying glycated peptides. PMID:18763275

Hierarchical combinatorial deep learning architecture for pancreas segmentation of medical computed tomography cancer images.

PubMed

Fu, Min; Wu, Wenming; Hong, Xiafei; Liu, Qiuhua; Jiang, Jialin; Ou, Yaobin; Zhao, Yupei; Gong, Xinqi

2018-04-24

Efficient computational recognition and segmentation of target organ from medical images are foundational in diagnosis and treatment, especially about pancreas cancer. In practice, the diversity in appearance of pancreas and organs in abdomen, makes detailed texture information of objects important in segmentation algorithm. According to our observations, however, the structures of previous networks, such as the Richer Feature Convolutional Network (RCF), are too coarse to segment the object (pancreas) accurately, especially the edge. In this paper, we extend the RCF, proposed to the field of edge detection, for the challenging pancreas segmentation, and put forward a novel pancreas segmentation network. By employing multi-layer up-sampling structure replacing the simple up-sampling operation in all stages, the proposed network fully considers the multi-scale detailed contexture information of object (pancreas) to perform per-pixel segmentation. Additionally, using the CT scans, we supply and train our network, thus get an effective pipeline. Working with our pipeline with multi-layer up-sampling model, we achieve better performance than RCF in the task of single object (pancreas) segmentation. Besides, combining with multi scale input, we achieve the 76.36% DSC (Dice Similarity Coefficient) value in testing data. The results of our experiments show that our advanced model works better than previous networks in our dataset. On the other words, it has better ability in catching detailed contexture information. Therefore, our new single object segmentation model has practical meaning in computational automatic diagnosis.

Two technicians apply insulation to S-II second stage

NASA Technical Reports Server (NTRS)

1964-01-01

Two technicians apply insulation to the outer surface of the S-II second stage booster for the Saturn V moon rocket. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Improved minimum cost and maximum power two stage genome-wide association study designs.

PubMed

Stanhope, Stephen A; Skol, Andrew D

2012-01-01

In a two stage genome-wide association study (2S-GWAS), a sample of cases and controls is allocated into two groups, and genetic markers are analyzed sequentially with respect to these groups. For such studies, experimental design considerations have primarily focused on minimizing study cost as a function of the allocation of cases and controls to stages, subject to a constraint on the power to detect an associated marker. However, most treatments of this problem implicitly restrict the set of feasible designs to only those that allocate the same proportions of cases and controls to each stage. In this paper, we demonstrate that removing this restriction can improve the cost advantages demonstrated by previous 2S-GWAS designs by up to 40%. Additionally, we consider designs that maximize study power with respect to a cost constraint, and show that recalculated power maximizing designs can recover a substantial amount of the planned study power that might otherwise be lost if study funding is reduced. We provide open source software for calculating cost minimizing or power maximizing 2S-GWAS designs.

Determination of Process Parameters in Multi-Stage Hydro-Mechanical Deep Drawing by FE Simulation

NASA Astrophysics Data System (ADS)

Kumar, D. Ravi; Manohar, M.

2017-09-01

In this work, analysis has been carried to simulate manufacturing of a near hemispherical bottom part with large depth by hydro-mechanical deep drawing with an aim to reduce the number of forming steps and to reduce the extent of thinning in the dome region. Inconel 718 has been considered as the material due to its importance in aerospace industry. It is a Ni-based super alloy and it is one of the most widely used of all super alloys primarily due to large-scale applications in aircraft engines. Using Finite Element Method (FEM), numerical simulations have been carried out for multi-stage hydro-mechanical deep drawing by using the same draw ratios and design parameters as in the case of conventional deep drawing in four stages. The results showed that the minimum thickness in the final part can be increased significantly when compared to conventional deep drawing. It has been found that the part could be deep drawn to the desired height (after trimming at the final stage) without any severe wrinkling. Blank holding force (BHF) and peak counter pressure have been found to have a strong influence on thinning in the component. Decreasing the coefficient of friction has marginally increased the minimum thickness in the final component. By increasing the draw ratio and optimizing BHF, counter pressure and die corner radius in the simulations, it has been found that it is possible to draw the final part in three stages. It has been found that thinning can be further reduced by decreasing the initial blank size without any reduction in the final height. This reduced the draw ratio at every stage and optimum combination of BHF and counter pressure have been found for the 3-stage process also.

Application of a territorial-based filtering algorithm in turbomachinery blade design optimization

NASA Astrophysics Data System (ADS)

Bahrami, Salman; Khelghatibana, Maryam; Tribes, Christophe; Yi Lo, Suk; von Fellenberg, Sven; Trépanier, Jean-Yves; Guibault, François

2017-02-01

A territorial-based filtering algorithm (TBFA) is proposed as an integration tool in a multi-level design optimization methodology. The design evaluation burden is split between low- and high-cost levels in order to properly balance the cost and required accuracy in different design stages, based on the characteristics and requirements of the case at hand. TBFA is in charge of connecting those levels by selecting a given number of geometrically different promising solutions from the low-cost level to be evaluated in the high-cost level. Two test case studies, a Francis runner and a transonic fan rotor, have demonstrated the robustness and functionality of TBFA in real industrial optimization problems.

A model for rigorously applying the Exploration, Preparation, Implementation, Sustainment (EPIS) framework in the design and measurement of a large scale collaborative multi-site study.

PubMed

Becan, Jennifer E; Bartkowski, John P; Knight, Danica K; Wiley, Tisha R A; DiClemente, Ralph; Ducharme, Lori; Welsh, Wayne N; Bowser, Diana; McCollister, Kathryn; Hiller, Matthew; Spaulding, Anne C; Flynn, Patrick M; Swartzendruber, Andrea; Dickson, Megan F; Fisher, Jacqueline Horan; Aarons, Gregory A

2018-04-13

This paper describes the means by which a United States National Institute on Drug Abuse (NIDA)-funded cooperative, Juvenile Justice-Translational Research on Interventions for Adolescents in the Legal System (JJ-TRIALS), utilized an established implementation science framework in conducting a multi-site, multi-research center implementation intervention initiative. The initiative aimed to bolster the ability of juvenile justice agencies to address unmet client needs related to substance use while enhancing inter-organizational relationships between juvenile justice and local behavioral health partners. The EPIS (Exploration, Preparation, Implementation, Sustainment) framework was selected and utilized as the guiding model from inception through project completion; including the mapping of implementation strategies to EPIS stages, articulation of research questions, and selection, content, and timing of measurement protocols. Among other key developments, the project led to a reconceptualization of its governing implementation science framework into cyclical form as the EPIS Wheel. The EPIS Wheel is more consistent with rapid-cycle testing principles and permits researchers to track both progressive and recursive movement through EPIS. Moreover, because this randomized controlled trial was predicated on a bundled strategy method, JJ-TRIALS was designed to rigorously test progress through the EPIS stages as promoted by facilitation of data-driven decision making principles. The project extended EPIS by (1) elucidating the role and nature of recursive activity in promoting change (yielding the circular EPIS Wheel), (2) by expanding the applicability of the EPIS framework beyond a single evidence-based practice (EBP) to address varying process improvement efforts (representing varying EBPs), and (3) by disentangling outcome measures of progression through EPIS stages from the a priori established study timeline. The utilization of EPIS in JJ-TRIALS provides a model for practical and applied use of implementation frameworks in real-world settings that span outer service system and inner organizational contexts in improving care for vulnerable populations. NCT02672150 . Retrospectively registered on 22 January 2016.

Transportation Demand Management Planning At Multi-Tenant Buildings, An Example Of Tdm Planning During Project

DOT National Transportation Integrated Search

1988-09-01

THIS GUIDE FOR DEVELOPERS, BUILDING OWNERS AND BUILDING MANAGERS IS ONE IN A SERIES OF SAMPLES OF TDM PLANS THAT ILLUSTRATE THE DESIGN AND PROPOSED APPLICATION OF TDM STRATEGIES. THIS SAMPLE PLAN WAS PREPARED FOR A FICTITIOUS BUILDING MANAGER NEAR DO...

INFORMATION MANAGEMENT AND RELATED QUALITY ASSURANCE FOR A LARGE SCALE, MULTI-SITE RESEARCH PROJECT

EPA Science Inventory

During the summer of 2000, as part of a U.S. Environmental Protection Agency study designed to improve microbial water quality monitoring protocols at public beaches, over 11,000 water samples were collected at five selected beaches across the country. At each beach, samples wer...

High frequency two-stage pulse tube cryocooler with base temperature below 20 K

NASA Astrophysics Data System (ADS)

Yang, L. W.; Thummes, G.

2005-02-01

High frequency (30-50 Hz) multi-stage pulse tube coolers that are capable of reaching temperatures close to 20 K or even lower are a subject of recent research and development activities. This paper reports on the design and test of a two-stage pulse tube cooler which is driven by a linear compressor with nominal input power of 200 W at an operating frequency of 30-45 Hz. A parallel configuration of the two pulse tubes is used with the warm ends of the pulse tubes located at ambient temperature. For both stages, the regenerator matrix consists of a stack of stainless steel screen. At an operating frequency of 35 Hz and with the first stage at 73 K a lowest stationary temperature of 19.6 K has been achieved at the second stage. The effects of input power, frequency, average pressure, and cold head orientation on the cooling performance are also reported. An even lower no-load temperature can be expected from the use of lead or other regenerator materials of high heat capacity in the second stage.

Analytical transmissibility based transfer path analysis for multi-energy-domain systems using four-pole parameter theory

NASA Astrophysics Data System (ADS)

Mashayekhi, Mohammad Jalali; Behdinan, Kamran

2017-10-01

The increasing demand to minimize undesired vibration and noise levels in several high-tech industries has generated a renewed interest in vibration transfer path analysis. Analyzing vibration transfer paths within a system is of crucial importance in designing an effective vibration isolation strategy. Most of the existing vibration transfer path analysis techniques are empirical which are suitable for diagnosis and troubleshooting purpose. The lack of an analytical transfer path analysis to be used in the design stage is the main motivation behind this research. In this paper an analytical transfer path analysis based on the four-pole theory is proposed for multi-energy-domain systems. Bond graph modeling technique which is an effective approach to model multi-energy-domain systems is used to develop the system model. In this paper an electro-mechanical system is used as a benchmark example to elucidate the effectiveness of the proposed technique. An algorithm to obtain the equivalent four-pole representation of a dynamical systems based on the corresponding bond graph model is also presented in this paper.

A note on sample size calculation for mean comparisons based on noncentral t-statistics.

PubMed

Chow, Shein-Chung; Shao, Jun; Wang, Hansheng

2002-11-01

One-sample and two-sample t-tests are commonly used in analyzing data from clinical trials in comparing mean responses from two drug products. During the planning stage of a clinical study, a crucial step is the sample size calculation, i.e., the determination of the number of subjects (patients) needed to achieve a desired power (e.g., 80%) for detecting a clinically meaningful difference in the mean drug responses. Based on noncentral t-distributions, we derive some sample size calculation formulas for testing equality, testing therapeutic noninferiority/superiority, and testing therapeutic equivalence, under the popular one-sample design, two-sample parallel design, and two-sample crossover design. Useful tables are constructed and some examples are given for illustration.

Differentially co-expressed interacting protein pairs discriminate samples under distinct stages of HIV type 1 infection.

PubMed

Yoon, Dukyong; Kim, Hyosil; Suh-Kim, Haeyoung; Park, Rae Woong; Lee, KiYoung

2011-01-01

Microarray analyses based on differentially expressed genes (DEGs) have been widely used to distinguish samples across different cellular conditions. However, studies based on DEGs have not been able to clearly determine significant differences between samples of pathophysiologically similar HIV-1 stages, e.g., between acute and chronic progressive (or AIDS) or between uninfected and clinically latent stages. We here suggest a novel approach to allow such discrimination based on stage-specific genetic features of HIV-1 infection. Our approach is based on co-expression changes of genes known to interact. The method can identify a genetic signature for a single sample as contrasted with existing protein-protein-based analyses with correlational designs. Our approach distinguishes each sample using differentially co-expressed interacting protein pairs (DEPs) based on co-expression scores of individual interacting pairs within a sample. The co-expression score has positive value if two genes in a sample are simultaneously up-regulated or down-regulated. And the score has higher absolute value if expression-changing ratios are similar between the two genes. We compared characteristics of DEPs with that of DEGs by evaluating their usefulness in separation of HIV-1 stage. And we identified DEP-based network-modules and their gene-ontology enrichment to find out the HIV-1 stage-specific gene signature. Based on the DEP approach, we observed clear separation among samples from distinct HIV-1 stages using clustering and principal component analyses. Moreover, the discrimination power of DEPs on the samples (70-100% accuracy) was much higher than that of DEGs (35-45%) using several well-known classifiers. DEP-based network analysis also revealed the HIV-1 stage-specific network modules; the main biological processes were related to "translation," "RNA splicing," "mRNA, RNA, and nucleic acid transport," and "DNA metabolism." Through the HIV-1 stage-related modules, changing stage-specific patterns of protein interactions could be observed. DEP-based method discriminated the HIV-1 infection stages clearly, and revealed a HIV-1 stage-specific gene signature. The proposed DEP-based method might complement existing DEG-based approaches in various microarray expression analyses.

Preliminary Design Considerations for Access and Operations in Earth-Moon L1/L2 Orbits

NASA Technical Reports Server (NTRS)

Folta, David C.; Pavlak, Thomas A.; Haapala, Amanda F.; Howell, Kathleen C.

2013-01-01

Within the context of manned spaceflight activities, Earth-Moon libration point orbits could support lunar surface operations and serve as staging areas for future missions to near-Earth asteroids and Mars. This investigation examines preliminary design considerations including Earth-Moon L1/L2 libration point orbit selection, transfers, and stationkeeping costs associated with maintaining a spacecraft in the vicinity of L1 or L2 for a specified duration. Existing tools in multi-body trajectory design, dynamical systems theory, and orbit maintenance are leveraged in this analysis to explore end-to-end concepts for manned missions to Earth-Moon libration points.

A new experimental apparatus for emissivity measurements of steel and the application of multi-wavelength thermometry to continuous casting billets

NASA Astrophysics Data System (ADS)

Wang, Peng; Hu, Zhenwei; Xie, Zhi; Yan, Ming

2018-05-01

An experimental apparatus has been designed for measuring the emissivity of a steel surface in both vacuum and oxidation atmosphere. The sample is heated with the method of electromagnetic induction in order to ensure the temperature uniformity. The radiance emitted from a sample is measured using a fiber-optic Fourier transform infrared spectrometer. Using this unique apparatus, we investigated the spectral (2-6 μm) and directional (0°-86°) emissivity of stainless steel 304 with different degrees of surface oxidation at temperatures ranging from 800 to 1100 °C. The experimental results show that the emissivity increases slightly with increasing temperature, which accords with the Hagen-Rubens relation. The emissivity increases rapidly at the initial stage of oxidation, but gradually reaches to a constant value after 20 min. In addition, the directional emissivity has a maximum value at the measuring angle of about 75°. The maximum uncertainty of emissivity is only 3.0% over all the measuring ranges, indicating that this experimental apparatus has a high reliability. In order to measure the surface temperature of casting billets based on multi-wavelength thermometry, the bivariate emissivity function with the two variables, wavelength and temperature, is determined. Temperature measurement results based on our technique are compared with those from common dual-wavelength radiation thermometry. Our approach reduces the measured temperature fluctuation from ±20.7 °C to ±2.8 °C and reflects the temperature variation with the changes of production parameters in real time.

Computer program for preliminary design analysis of axial-flow turbines

NASA Technical Reports Server (NTRS)

Glassman, A. J.

1972-01-01

The program method is based on a mean-diameter flow analysis. Input design requirements include power or pressure ratio, flow, temperature, pressure, and speed. Turbine designs are generated for any specified number of stages and for any of three types of velocity diagrams (symmetrical, zero exit swirl, or impulse). Exit turning vanes can be included in the design. Program output includes inlet and exit annulus dimensions, exit temperature and pressure, total and static efficiencies, blading angles, and last-stage critical velocity ratios. The report presents the analysis method, a description of input and output with sample cases, and the program listing.

A two-stage cluster sampling method using gridded population data, a GIS, and Google Earth(TM) imagery in a population-based mortality survey in Iraq.

PubMed

Galway, Lp; Bell, Nathaniel; Sae, Al Shatari; Hagopian, Amy; Burnham, Gilbert; Flaxman, Abraham; Weiss, Wiliam M; Rajaratnam, Julie; Takaro, Tim K

2012-04-27

Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

PubMed Central

2012-01-01

Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings. PMID:22540266

Multi-stage classification method oriented to aerial image based on low-rank recovery and multi-feature fusion sparse representation.

PubMed

Ma, Xu; Cheng, Yongmei; Hao, Shuai

2016-12-10

Automatic classification of terrain surfaces from an aerial image is essential for an autonomous unmanned aerial vehicle (UAV) landing at an unprepared site by using vision. Diverse terrain surfaces may show similar spectral properties due to the illumination and noise that easily cause poor classification performance. To address this issue, a multi-stage classification algorithm based on low-rank recovery and multi-feature fusion sparse representation is proposed. First, color moments and Gabor texture feature are extracted from training data and stacked as column vectors of a dictionary. Then we perform low-rank matrix recovery for the dictionary by using augmented Lagrange multipliers and construct a multi-stage terrain classifier. Experimental results on an aerial map database that we prepared verify the classification accuracy and robustness of the proposed method.

The Association between Socioeconomic Status and Obesity in Peruvian Women

PubMed Central

Poterico, J.A.; Stanojevic, S.; Ruiz, P.; Bernabe-Ortiz, A.; Miranda, J. J.

2012-01-01

Historically in developing countries, the prevalence of obesity has been greater in more advantaged socioeconomic groups. However, in recent years the association between socioeconomic status (SES) and obesity has changed and varies depending on the country’s development stage. This study examines the relationship between SES and obesity using two indicators of SES: education or possession assets. Using the cross-sectional 2008 National Demographic and Family Health Survey of Peru (ENDES 2008) we investigated this relationship in women aged 15 to 49 years living in rural and urban settings. Descriptive, linear and logistic regressions analyses were conducted accounting for the multi-staged nature of the sampling design. The overall prevalence of obesity in this study was 14.1% (95%CI: 13.3–14.8); 8.4% (95%CI: 7.5–9.3) in rural areas and 16.2% (95%CI: 15.2–17-2) in urban areas. Wealthier women were more likely to be obese, and this association was stronger in rural areas. Conversely, more educated women were less likely to be obese, especially in urban areas. The distribution of obesity in Peruvian women is strongly related to socioeconomic position, and differs whether measured as possession assets or by level of education. These findings could have important implications for policy development in Peru. PMID:21959344

SU-E-T-480: Radiobiological Dose Comparison of Single Fraction SRS, Multi-Fraction SRT and Multi-Stage SRS of Large Target Volumes Using the Linear-Quadratic Formula

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

Ding, C; Hrycushko, B; Jiang, S

2014-06-01

Purpose: To compare the radiobiological effect on large tumors and surrounding normal tissues from single fraction SRS, multi-fractionated SRT, and multi-staged SRS treatment. Methods: An anthropomorphic head phantom with a centrally located large volume target (18.2 cm{sup 3}) was scanned using a 16 slice large bore CT simulator. Scans were imported to the Multiplan treatment planning system where a total prescription dose of 20Gy was used for a single, three staged and three fractionated treatment. Cyber Knife treatment plans were inversely optimized for the target volume to achieve at least 95% coverage of the prescription dose. For the multistage plan,more » the target was segmented into three subtargets having similar volume and shape. Staged plans for individual subtargets were generated based on a planning technique where the beam MUs of the original plan on the total target volume are changed by weighting the MUs based on projected beam lengths within each subtarget. Dose matrices for each plan were export in DICOM format and used to calculate equivalent dose distributions in 2Gy fractions using an alpha beta ratio of 10 for the target and 3 for normal tissue. Results: Singe fraction SRS, multi-stage plan and multi-fractionated SRT plans had an average 2Gy dose equivalent to the target of 62.89Gy, 37.91Gy and 33.68Gy, respectively. The normal tissue within 12Gy physical dose region had an average 2Gy dose equivalent of 29.55Gy, 16.08Gy and 13.93Gy, respectively. Conclusion: The single fraction SRS plan had the largest predicted biological effect for the target and the surrounding normal tissue. The multi-stage treatment provided for a more potent biologically effect on target compared to the multi-fraction SRT treatments with less biological normal tissue than single-fraction SRS treatment.« less

Acoustic Analysis and Design of the E-STA MSA Simulator

NASA Technical Reports Server (NTRS)

Bittinger, Samantha A.

2016-01-01

The Orion European Service Module Structural Test Article (E-STA) Acoustic Test was completed in May 2016 to verify that the European Service Module (ESM) can withstand qualification acoustic environments. The test article required an aft closeout to simulate the Multi-Purpose Crew Vehicle (MPCV) Stage Adapter (MSA) cavity, however, the flight MSA design was too cost-prohibitive to build. NASA Glenn Research Center (GRC) had 6 months to design an MSA Simulator that could recreate the qualification prediction MSA cavity sound pressure level to within a reasonable tolerance. This paper summarizes the design and analysis process to arrive at a design for the MSA Simulator, and then compares its performance to the final prediction models created prior to test.

Optimization Strategies for Single-Stage, Multi-Stage and Continuous ADRs

NASA Technical Reports Server (NTRS)

Shirron, Peter J.

2014-01-01

Adiabatic Demagnetization Refrigerators (ADR) have many advantages that are prompting a resurgence in their use in spaceflight and laboratory applications. They are solid-state coolers capable of very high efficiency and very wide operating range. However, their low energy storage density translates to larger mass for a given cooling capacity than is possible with other refrigeration techniques. The interplay between refrigerant mass and other parameters such as magnetic field and heat transfer points in multi-stage ADRs gives rise to a wide parameter space for optimization. This paper first presents optimization strategies for single ADR stages, focusing primarily on obtaining the largest cooling capacity per stage mass, then discusses the optimization of multi-stage and continuous ADRs in the context of the coordinated heat transfer that must occur between stages. The goal for the latter is usually to obtain the largest cooling power per mass or volume, but there can also be many secondary objectives, such as limiting instantaneous heat rejection rates and producing intermediate temperatures for cooling of other instrument components.

Characteristics of Boundary Layer Transition in a Multi-Stage Low-Pressure Turbine

NASA Technical Reports Server (NTRS)

Wisler, Dave; Halstead, David E.; Okiishi, Ted

2007-01-01

An experimental investigation of boundary layer transition in a multi-stage turbine has been completed using surface-mounted hot-film sensors. Tests were carried out using the two-stage Low Speed Research Turbine of the Aerodynamics Research Laboratory of GE Aircraft Engines. Blading in this facility models current, state-of-the-art low pressure turbine configurations. The instrumentation technique involved arrays of densely-packed hot-film sensors on the surfaces of second stage rotor and nozzle blades. The arrays were located at mid-span on both the suction and pressure surfaces. Boundary layer measurements were acquired over a complete range of relevant Reynolds numbers. Data acquisition capabilities provided means for detailed data interrogation in both time and frequency domains. Data indicate that significant regions of laminar and transitional boundary layer flow exist on the rotor and nozzle suction surfaces. Evidence of relaminarization both near the leading edge of the suction surface and along much of the pressure surface was observed. Measurements also reveal the nature of the turbulent bursts occuring within and between the wake segments convecting through the blade row. The complex character of boundary layer transition resulting from flow unsteadiness due to nozzle/nozzle, rotor/nozzle, and nozzle/rotor wake interactions are elucidated using these data. These measurements underscore the need to provide turbomachinery designers with models of boundary layer transition to facilitate accurate prediction of aerodynamic loss and heat transfer.

Variable Circumstellar Disks of “Classical” Be Stars, Part 2

NASA Astrophysics Data System (ADS)

Gerhartz, Cody; Davidson, J. W.; Bjorkman, K. S.; Wisniewski, J. P.

2014-01-01

Circumstellar disks are common among many stars, all spectral types, and at different stages of their lifetimes. Among the near-main sequence “Classical” Be stars, there is growing evidence that these disks can form, dissipate, and reform, on timescales that are differ from case to case. We present data for a subset of cases where observations have been obtained throughout the different phases of the disk cycle. Using data obtained with the SpeX instrument at the NASA IRTF, we examine the IR spectral line variability of these stars to better understand the timescales and the physical mechanisms involved. The primary focus in this study are the V/R variations that are observed in the sample. A complete run of all double-peaked velocity profiles in the sample is now complete. The second stage of our project is to examine a sample of star clusters known to contain Be stars, with the goal to develop a more statistically significant sample of variable circumstellar disk systems. With a robust multi-epoch study we can determine whether these Be stars exhibit disk-loss or disk-renewal phases. The larger sample will enable an understanding of the prevalence of these disk events.

Use of focus groups in multi-site, multi-ethnic research projects for women's health: a Study of Women Across the Nation (swan) example.

PubMed

Kagawa-Singer, Marjorie; Adler, Shelley R; Mouton, Charles E; Ory, Marcia; Underwood, Lynne G

2009-01-01

To outline the lessons learned about the use of focus groups for the multisite, multi-ethnic longitudinal Study of Women Across the Nation (SWAN). Focus groups were designed to identify potential cultural differences in the incidence of symptoms and the meaning of transmenopause among women of diverse cultures, and to identify effective recruitment and retention strategies. Inductive and deductive focus groups for a multi-ethnic study. Seven community research sites across the United States conducted focus groups with six ethnic populations: African American, Chinese American, Japanese American, Mexican American, non-Hispanic white, and Puerto Rican. Community women from each ethnic group of color. A set of four/five focus groups in each ethnic group as the formative stage of the deductive, quantitative SWAN survey. Identification of methodological advantages and challenges to the successful implementation of formative focus groups in a multi-ethnic, multi-site population-based epidemiologic study. We provide recommendations from our lessons learned to improve the use of focus groups in future studies with multi-ethnic populations. Mixed methods using inductive and deductive approaches require the scientific integrity of both research paradigms. Adequate resources and time must be budgeted as essential parts of the overall strategy from the outset of study. Inductive cross-cultural researchers should be key team members, beginning with inception through each subsequent design phase to increase the scientific validity, generalizability, and comparability of the results across diverse ethnic groups, to assure the relevance, validity and applicability of the findings to the multicultural population of focus.

Organic-Inorganic Hybrid Materials: Multi-Functional Solids for Multi-Step Reaction Processes.

PubMed

Díaz, Urbano; Corma, Avelino

2018-03-15

The design of new hybrid materials with tailored properties at the nano-, meso-, and macro-scale, with the use of structural functional nanobuilding units, is carried out to obtain specific multi-functional materials. Organization into controlled 1D, 2D, and 3D architectures with selected functionalities is key for developing advanced catalysts, but this is hardly accomplished using conventional synthesis procedures. The use of pre-formed nanostructures, derived either from known materials or made with specific innovative synthetic methodologies, has enormous potential in the generation of multi-site catalytic materials for one-pot processes. The present concept article introduces a new archetype wherein self-assembled nanostructured builder units are the base for the design of multifunctional catalysts, which combine catalytic efficiency with fast reactant and product diffusion. The article addresses a new generation of versatile hybrid organic-inorganic multi-site catalytic materials for their use in the production of (chiral) high-added-value products within the scope of chemicals and fine chemicals production. The use of those multi-reactive solids for more nanotechnological applications, such as sensors, due to the inclusion of electron donor-acceptor structural arrays is also considered, together with the adsorption-desorption capacities due to the combination of hydrophobic and hydrophilic sub-domains. The innovative structured hybrid materials for multipurpose processes here considered, can allow the development of multi-stage one-pot reactions with industrial applications, using the materials as one nanoreactor systems, favoring more sustainable production pathways with economic, environmental and energetic advantages. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase II trial of CoQ10 for ALS finds insufficient evidence to justify Phase III

PubMed Central

Kaufmann, Petra; Thompson, John L.P.; Levy, Gilberto; Buchsbaum, Richard; Shefner, Jeremy; Krivickas, Lisa S.; Katz, Jonathan; Rollins, Yvonne; Barohn, Richard J.; Jackson, Carlayne E.; Tiryaki, Ezgi; Lomen-Hoerth, Catherine; Armon, Carmel; Tandan, Rup; Rudnicki, Stacy A.; Rezania, Kourosh; Sufit, Robert; Pestronk, Alan; Novella, Steven P.; Heiman-Patterson, Terry; Kasarskis, Edward J.; Pioro, Erik P.; Montes, Jacqueline; Arbing, Rachel; Vecchio, Darleen; Barsdorf, Alexandra; Mitsumoto, Hiroshi; Levin, Bruce

2010-01-01

Objective Amyotrophic lateral sclerosis (ALS) is a devastating, and currently incurable, neuromuscular disease in which oxidative stress and mitochondrial impairment are contributing to neuronal loss. Coenzyme Q10 (CoQ10), an antioxidant and mitochondrial cofactor, has shown promise in ALS transgenic mice, and in clinical trials for neurodegenerative diseases other than ALS. Our aims were to choose between two high doses of CoQ10 for ALS, and to determine if it merits testing in a Phase III clinical trial. Methods We designed and implemented a multi-center trial with an adaptive, two-stage, bias-adjusted, randomized, placebo-controlled, double-blind, Phase II design (n=185). The primary outcome in both stages was decline in the ALS Functional Rating Scale-revised (ALSFRSr) score over 9 months. Stage 1 (dose selection, 35 participants per group) compared CoQ10 doses of 1,800 and 2,700 mg/day. Stage 2 (futility test, 75 patients per group) compared the dose selected in Stage 1 against placebo. Results Stage 1 selected the 2,700 mg dose. In Stage 2, the pre-specified primary null hypothesis that this dose is superior to placebo was not rejected. It was rejected, however, in an accompanying pre-specified sensitivity test, and further supplementary analyses. Pre-specified secondary analyses showed no significant differences between CoQ10 at 2,700 mg/day and placebo. There were no safety concerns. Interpretation CoQ10 at 2,700 mg daily for 9 months shows insufficient promise to warrant Phase III testing. Given this outcome, the adaptive Phase II design incorporating a dose selection and a futility test avoided the need for a much larger conventional Phase III trial. PMID:19743457

Application of a multi-channel system for continuous monitoring and an early warning system.

PubMed

Lee, J H; Song, C H; Kim, B C; Gu, M B

2006-01-01

A multi-channel continuous toxicity monitoring system developed in our laboratory, based on two-stage mini-bioreactors, was successfully implemented in the form of computer-based data acquisition. The multi-channel system consists of a series of a two-stage minibioreactor systems connected by a fiber optic probe to a luminometer, and uses genetically engineered bioluminescent bacteria for the detection of the potential toxicity from the soluble chemicals. This system can be stably and continuously operated due to the separation of the culture reactor from the test reactor and accomplish easy and long-term monitoring without system shut down by abrupt inflows of severe polluting chemicals. Four different recombinant bioluminescent bacteria were used in different channels so that the modes of the samples toxicities can be reasonably identified and evaluated based upon the response signature of each channel. The bioluminescent signatures were delivered from four channels by switching one at once, while the data is automatically logged to an IBM compatible computer. We also achieved the enhancement of the system through the manipulation of the dilution rate and the use of thermo-lux fusion strains. Finally, this system is now being implemented to a drinking water reservoir and river for remote sensing as an early warning system.

An embedded multi-core parallel model for real-time stereo imaging

NASA Astrophysics Data System (ADS)

He, Wenjing; Hu, Jian; Niu, Jingyu; Li, Chuanrong; Liu, Guangyu

2018-04-01

The real-time processing based on embedded system will enhance the application capability of stereo imaging for LiDAR and hyperspectral sensor. The task partitioning and scheduling strategies for embedded multiprocessor system starts relatively late, compared with that for PC computer. In this paper, aimed at embedded multi-core processing platform, a parallel model for stereo imaging is studied and verified. After analyzing the computing amount, throughout capacity and buffering requirements, a two-stage pipeline parallel model based on message transmission is established. This model can be applied to fast stereo imaging for airborne sensors with various characteristics. To demonstrate the feasibility and effectiveness of the parallel model, a parallel software was designed using test flight data, based on the 8-core DSP processor TMS320C6678. The results indicate that the design performed well in workload distribution and had a speed-up ratio up to 6.4.

Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Hardware

NASA Astrophysics Data System (ADS)

Kang, Y.-W.; Byun, Y. I.; Rhee, J. H.; Oh, S. H.; Kim, D. K.

2007-12-01

We designed and developed a multi-purpose CCD camera system for three kinds of CCDs; KAF-0401E(768×512), KAF-1602E(1536×1024), KAF-3200E(2184×1472) made by KODAK Co.. The system supports fast USB port as well as parallel port for data I/O and control signal. The packing is based on two stage circuit boards for size reduction and contains built-in filter wheel. Basic hardware components include clock pattern circuit, A/D conversion circuit, CCD data flow control circuit, and CCD temperature control unit. The CCD temperature can be controlled with accuracy of approximately 0.4° C in the max. range of temperature, Δ 33° C. This CCD camera system has with readout noise 6 e^{-}, and system gain 5 e^{-}/ADU. A total of 10 CCD camera systems were produced and our tests show that all of them show passable performance.

Cloud-based image sharing network for collaborative imaging diagnosis and consultation

NASA Astrophysics Data System (ADS)

Yang, Yuanyuan; Gu, Yiping; Wang, Mingqing; Sun, Jianyong; Li, Ming; Zhang, Weiqiang; Zhang, Jianguo

2018-03-01

In this presentation, we presented a new approach to design cloud-based image sharing network for collaborative imaging diagnosis and consultation through Internet, which can enable radiologists, specialists and physicians locating in different sites collaboratively and interactively to do imaging diagnosis or consultation for difficult or emergency cases. The designed network combined a regional RIS, grid-based image distribution management, an integrated video conferencing system and multi-platform interactive image display devices together with secured messaging and data communication. There are three kinds of components in the network: edge server, grid-based imaging documents registry and repository, and multi-platform display devices. This network has been deployed in a public cloud platform of Alibaba through Internet since March 2017 and used for small lung nodule or early staging lung cancer diagnosis services between Radiology departments of Huadong hospital in Shanghai and the First Hospital of Jiaxing in Zhejiang Province.

Statistical properties of mean stand biomass estimators in a LIDAR-based double sampling forest survey design.

Treesearch

H.E. Anderson; J. Breidenbach

2007-01-01

Airborne laser scanning (LIDAR) can be a valuable tool in double-sampling forest survey designs. LIDAR-derived forest structure metrics are often highly correlated with important forest inventory variables, such as mean stand biomass, and LIDAR-based synthetic regression estimators have the potential to be highly efficient compared to single-stage estimators, which...

Prognostic Significance of Nodal Location and Ratio in Stage IIIC Endometrial Carcinoma Among a Multi-Institutional Academic Collaboration.

PubMed

Mayadev, Jyoti; Elshaikh, Mohamed A; Christie, Alana; Nagel, Christa; Kennedy, Vanessa; Khan, Nadia; Lea, Jayanthi; Ghanem, Ahmad; Miller, David; Xie, Xian-Jin; Folkert, Michael; Albuquerque, Kevin

2018-04-20

Stage IIIC endometrial carcinoma (EC) represents pathologically heterogenous patients with single/multiple pelvic (stage IIIC1) or paraaortic (stage IIIC2) lymph nodes (LNs). There is an increasing trend to offer adjuvant chemotherapy (CT) +/- radiation (RT) uniformly to these patients, regardless of substage. We investigate the prognostic significance of positive LN (pLN) number, ratio (%pLN), location (IIC1 vs. IIC2), and adjuvant treatment on patterns of failure and survival in a large collaborative multi-institutional series. Clinical data for stage III EC patients such as patient characteristics, surgery/pathologic details, adjuvant therapies (including CT, RT, and chemotherapy and radiation), and outcomes (including pelvic control [PC], disease-free survival [DFS], distant DFS, and overall survival [OS]) were collected from 3 academic institutions. Log-rank analyses, Cox regression univariate and multivariate analyses were performed. Of the 264 patients queried for stage III disease, 237 (73%) had pLN, and complete LN sampling for analysis. The mean number of pLN in the combined data were 3.9, with 26.1% of all LN sampled positive; 121 patients (51%) staged IIIC1, and 116 patients (49%) staged IIIC2. There was a significant difference in number of pLN (P=0.0006) and total LN sampled by institution (range, 13 to 35; P=0.0004), without a difference in %pLN (P=0.35). Ninety-seven of 220 (44.1%) have ≥20% pLN. While controlling for substage and institution, a decrease in DFS (hazard ratio [HR], 1.1; P=0.007), and OS (HR, 1.1; P=0.01) was observed with every increase of 10% in the pLN ratio. There was a significant difference in DFS (HR, 1.8; P=0.003), PC (HR, 1.9; P=0.004), and distant DFS (HR, 1.6; P=0.03), as well as a trend for decreased OS (HR, 1.6; P=0.08) for substage IIIC2 versus IIIC1 disease; 5 years DFS 40% versus 45%, OS 50% versus 57%. Patients received no adjuvant therapy (10%), CT alone (27%), RT alone (16%), or chemotherapy and radiation (47%). There was no significant difference in PC, DFS, or OS between the various treatment regimens. On univariate analysis, while pLN was significant, treatment type did not impact DFS or OS. On multivariate analysis for DFS, patient age, race, and IIIC1 versus IIIC2 substage retained significance (HR, 0.56; P=0.01). Stage III EC patients with substage IIIC2 disease have a significantly increased risk of local and distant disease recurrence and death from EC. A decrease in DFS and OS was observed with every increase of 10% in the pLN ratio. Stage IIIC2 patients represent a high-risk subpopulation for whom clinical trials, or targeted regimens should be explored to achieve improved oncologic outcomes.

TBCC Fan Stage Operability and Performance

NASA Technical Reports Server (NTRS)

Suder, Kenneth L.

2007-01-01

NASA s Fundamental Aeronautics Program is investigating turbine-based propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. Studies performed under NASA s NGLT and the NASP High Speed Propulsion Assessment (HiSPA) program indicated a variable cycle turbofan/ramjet was the best configuration to satisfy access-to-space mission requirements because this configuration maximizes the engine thrust-to-weight ratio while minimizing frontal area. To this end, NASA and GE teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10X), fan speed (7X), inlet mass flow (3.5X), inlet pressure (8X), and inlet temperature (3X). The primary goal of the fan stage was to provide a high pressure ratio level with good efficiency at takeoff through the mid range of engine operation, while avoiding stall and losses at the higher flight Mach numbers, without the use of variable inlet guide vanes. Overall fan performance and operability therefore requires major consideration, as competing goals at different operating points and aeromechanical issues become major drivers in the design. To mitigate risk of meeting the unique design requirements for the fan stage, NASA and GE teamed to design and build a 57% engine scaled fan stage to be tested in NASA s transonic compressor facility. The objectives of this test are to assess the aerodynamic and aero mechanic performance and operability characteristics of the fan stage over the entire range of engine operation including: 1) sea level static take-off, 2) transition over large swings in fan bypass ratio, 3) transition from turbofan to ramjet, and 4) fan windmilling operation at high Mach flight conditions. In addition, the fan stage design was validated by performing pre-test CFD analysis using both GE proprietary and NASA s APNASA codes. Herein we will discuss 1) the fan stage design, 2) the experiment including the unique facility and instrumentation, and 3) the comparison of pre-test CFD analysis to initial aerodynamic test results for the baseline fan stage configuration. Measurements and pre-test analysis will be compared at 37%, 50%, 80%, 90%, and 100% of design speed to assess the ability of state-of-the-art design and analysis tools to meet the fan stage performance and operability requirements for turbine based propulsion for access to space.

Second Stage (S-II) Arrives at Marshall Space Flight Center For Testing

NASA Technical Reports Server (NTRS)

2004-01-01

The business end of a Second Stage (S-II) slowly emerges from the shipping container as workers prepare to transport the Saturn V component to the testing facility at MSFC. The Second Stage (S-II) underwent vibration and engine firing tests. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Saturn Apollo Program

NASA Image and Video Library

1965-04-26

Two technicians watch carefully as cables prepare to lift a J-2 engine into a test stand. The J-2 powered the second stage and the third stage of the Saturn V moon rocket. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Applications of the Magnetocaloric Effect in Single-Stage, Multi-Stage and Continuous Adiabatic Demagnetization Refrigerators

NASA Technical Reports Server (NTRS)

Shirron, Peter J.

2014-01-01

Adiabatic demagnetization refrigerators (ADR), based on the magnetocaloric effect, are solid-state coolers that were the first to achieve cooling well into the sub-kelvin regime. Although supplanted by more powerful dilution refrigerators in the 1960s, ADRs have experienced a revival due to the needs of the space community for cooling astronomical instruments and detectors to temperatures below 100 mK. The earliest of these were single-stage refrigerators using superfluid helium as a heat sink. Their modest cooling power (<1 µW at 60 mK[1]) was sufficient for the small (6x6) detector arrays[2], but recent advances in arraying and multiplexing technologies[3] are generating a need for higher cooling power (5-10 µW), and lower temperature (<30 mK). Single-stage ADRs have both practical and fundamental limits to their operating range, as mass grows very rapidly as the operating range is expanded. This has led to the development of new architectures that introduce multi-staging as a way to improve operating range, efficiency and cooling power. Multi-staging also enables ADRs to be configured for continuous operation, which greatly improves cooling power per unit mass. This paper reviews the current field of adiabatic demagnetization refrigeration, beginning with a description of the magnetocaloric effect and its application in single-stage systems, and then describing the challenges and capabilities of multi-stage and continuous ADRs.

Multi-Wave Prospective Examination of the Stress-Reactivity Extension of Response Styles Theory of Depression in High-Risk Children and Early Adolescents

ERIC Educational Resources Information Center

Abela, John R. Z.; Hankin, Benjamin L.; Sheshko, Dana M.; Fishman, Michael B.; Stolow, Darren

2012-01-01

The current study tested the stress-reactivity extension of response styles theory of depression (Nolen-Hoeksema "Journal of Abnormal Psychology" 100:569-582, 1991) in a sample of high-risk children and early adolescents from a vulnerability-stress perspective using a multi-wave longitudinal design. In addition, we examined whether obtained…

Grouping methods for estimating the prevalences of rare traits from complex survey data that preserve confidentiality of respondents.

PubMed

Hyun, Noorie; Gastwirth, Joseph L; Graubard, Barry I

2018-03-26

Originally, 2-stage group testing was developed for efficiently screening individuals for a disease. In response to the HIV/AIDS epidemic, 1-stage group testing was adopted for estimating prevalences of a single or multiple traits from testing groups of size q, so individuals were not tested. This paper extends the methodology of 1-stage group testing to surveys with sample weighted complex multistage-cluster designs. Sample weighted-generalized estimating equations are used to estimate the prevalences of categorical traits while accounting for the error rates inherent in the tests. Two difficulties arise when using group testing in complex samples: (1) How does one weight the results of the test on each group as the sample weights will differ among observations in the same group. Furthermore, if the sample weights are related to positivity of the diagnostic test, then group-level weighting is needed to reduce bias in the prevalence estimation; (2) How does one form groups that will allow accurate estimation of the standard errors of prevalence estimates under multistage-cluster sampling allowing for intracluster correlation of the test results. We study 5 different grouping methods to address the weighting and cluster sampling aspects of complex designed samples. Finite sample properties of the estimators of prevalences, variances, and confidence interval coverage for these grouping methods are studied using simulations. National Health and Nutrition Examination Survey data are used to illustrate the methods. Copyright © 2018 John Wiley & Sons, Ltd.

Regional Geochemistry - an Introduction

NASA Astrophysics Data System (ADS)

Reimann, Clemens

2017-04-01

Building on the pioneering ideas and work of V. Vernadsky (1883-1945) and V.M. Goldschmidt (1888-1947) the Geological Surveys of Europe have more than 60 years experience with geochemical mapping at a large variety of scales. Surveys using hundreds of samples per km2 for mineral exploration projects, 1 to 4 sites per km2 for mapping the urban environment, 1 site per 2 to 10 km2 in county or country-wide mapping projects to 1 site per 1000 to 5000 km2 for mapping at the continental scale have been successfully completed. Sample materials for these surveys include groundwater, surface water, stream sediments, floodplain sediments, different soil horizons (preferably soil O, A, B and C horizon) and plant materials from moss to trees. Surveys combining several sample materials from local to sub-continental scale in multi-media, multi-element geochemical investigations reflecting the interplay of chemical elements between the different compartments (lithosphere, pedosphere, biosphere and hydrosphere) of the ecosystem have also been carried out. These surveys provide ample empirical evidence that different geochemical processes become visible at different scales. Not all sample materials are suitable for all scales. A variety of scales in combination with a variety of different sample materials are needed to fully understand geochemical processes in the critical zone. Examples are shown that highlight the importance of a strategy to optimize sampling density and design for the chosen scale already during the planning stages of a project. Anthropogenic element sources are visible at a local scale and the major impact of geology, mineralogy and climate (as a driving force for weathering) dominates geochemical maps at the continental scale. Interestingly, mineralisation can generate features which are visible at a variety of scales. Some further issues that need attention when carrying out geochemical surveys at a variety of scales are (a) the need for an excellent and well documented analytical quality control, (b) the choice of the elements to be analysed (as many as possible) (c) the required detection limits (the lowest possible) and (d) the choice of extraction (several if feasible).

An optimal design of wind turbine and ship structure based on neuro-response surface method

NASA Astrophysics Data System (ADS)

Lee, Jae-Chul; Shin, Sung-Chul; Kim, Soo-Young

2015-07-01

The geometry of engineering systems affects their performances. For this reason, the shape of engineering systems needs to be optimized in the initial design stage. However, engineering system design problems consist of multi-objective optimization and the performance analysis using commercial code or numerical analysis is generally time-consuming. To solve these problems, many engineers perform the optimization using the approximation model (response surface). The Response Surface Method (RSM) is generally used to predict the system performance in engineering research field, but RSM presents some prediction errors for highly nonlinear systems. The major objective of this research is to establish an optimal design method for multi-objective problems and confirm its applicability. The proposed process is composed of three parts: definition of geometry, generation of response surface, and optimization process. To reduce the time for performance analysis and minimize the prediction errors, the approximation model is generated using the Backpropagation Artificial Neural Network (BPANN) which is considered as Neuro-Response Surface Method (NRSM). The optimization is done for the generated response surface by non-dominated sorting genetic algorithm-II (NSGA-II). Through case studies of marine system and ship structure (substructure of floating offshore wind turbine considering hydrodynamics performances and bulk carrier bottom stiffened panels considering structure performance), we have confirmed the applicability of the proposed method for multi-objective side constraint optimization problems.

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

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I 3TEM) offers the unique ability to observe microstructural changes duemore » to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. As a result, this work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO 2.« less

Kinetics of the pyrolysis of arundo, sawdust, corn stover and switch grass biomass by thermogravimetric analysis using a multi-stage model.

PubMed

Biney, Paul O; Gyamerah, Michael; Shen, Jiacheng; Menezes, Bruna

2015-03-01

A new multi-stage kinetic model has been developed for TGA pyrolysis of arundo, corn stover, sawdust and switch grass that accounts for the initial biomass weight (W0). The biomass were decomposed in a nitrogen atmosphere from 23°C to 900°C in a TGA at a single 20°C/min ramp rate in contrast with the isoconversion technique. The decomposition was divided into multiple stages based on the absolute local minimum values of conversion derivative, (dx/dT), obtained from DTG curves. This resulted in three decomposition stages for arundo, corn stover and sawdust and four stages for switch grass. A linearized multi-stage model was applied to the TGA data for each stage to determine the pre-exponential factor, activation energy, and reaction order. The activation energies ranged from 54.7 to 60.9 kJ/mol, 62.9 to 108.7 kJ/mol, and 18.4 to 257.9 kJ/mol for the first, second and the third decomposition stages respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multiphase flow models for hydraulic fracturing technology

NASA Astrophysics Data System (ADS)

Osiptsov, Andrei A.

2017-10-01

The technology of hydraulic fracturing of a hydrocarbon-bearing formation is based on pumping a fluid with particles into a well to create fractures in porous medium. After the end of pumping, the fractures filled with closely packed proppant particles create highly conductive channels for hydrocarbon flow from far-field reservoir to the well to surface. The design of the hydraulic fracturing treatment is carried out with a simulator. Those simulators are based on mathematical models, which need to be accurate and close to physical reality. The entire process of fracture placement and flowback/cleanup can be conventionally split into the following four stages: (i) quasi-steady state effectively single-phase suspension flow down the wellbore, (ii) particle transport in an open vertical fracture, (iii) displacement of fracturing fluid by hydrocarbons from the closed fracture filled with a random close pack of proppant particles, and, finally, (iv) highly transient gas-liquid flow in a well during cleanup. The stage (i) is relatively well described by the existing hydralics models, while the models for the other three stages of the process need revisiting and considerable improvement, which was the focus of the author’s research presented in this review paper. For stage (ii), we consider the derivation of a multi-fluid model for suspension flow in a narrow vertical hydraulic fracture at moderate Re on the scale of fracture height and length and also the migration of particles across the flow on the scale of fracture width. At the stage of fracture cleanaup (iii), a novel multi-continua model for suspension filtration is developed. To provide closure relationships for permeability of proppant packings to be used in this model, a 3D direct numerical simulation of single phase flow is carried out using the lattice-Boltzmann method. For wellbore cleanup (iv), we present a combined 1D model for highly-transient gas-liquid flow based on the combination of multi-fluid and drift-flux approaches. The derivation of the drift-flux model from conservation olaws is criticall revisited in order to define the list of underlying assumptions and to mark the applicability margins of the model. All these fundamental problems share the same technological application (hydraulic fracturing) and the same method of research, namely, the multi-fluid approach to multiphase flow modeling and the consistent use of asymptotic methods. Multi-fluid models are then discussed in comparison with semi-empirical (often postulated) models widely used in the industry.

Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments

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

Wang, Anbo

This report summarizes technical progress on the program “Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology at Virginia Tech. The objective of this project is to develop a first-of-a-kind technology for remote fiber optic generation and detection of acoustic waves for structural health monitoring in harsh environments. During the project period, which is from April 1, 2013 to Septemeber 30, 2016, three different acoustic generation mechanisms were studied in detail for their applications inmore » building a fiber optic acoustic generation unit (AGU), including laser induced plasma breakdown (LIP), Erbium-doped fiber laser absorption, and metal laser absorption. By comparing the performance of the AGUs designed based on these three mechanisms and analyzing the experimental results with simulations, the metal laser absorption method was selected to build a complete fiber optic structure health monitoring (FO-SHM) system for the proposed high temperature multi-parameter structure health monitoring application. Based on the simulation of elastic wave propagation and fiber Bragg grating acoustic pulse detection, an FO-SHM element together with a completed interrogation system were designed and built. This system was first tested on an aluminum piece in the low-temperature range and successfully demonstrated its capability of multi-parameter monitoring and multi-point sensing. In the later stages of the project, the research was focused on improving the surface attachment design and preparing the FO-SHM element for high temperature environment tests. After several upgrades to the surface attachment methods, the FO-SHM element was able to work reliably up to 600oC when attached to P91 pipes, which are the target material of this project. In the final stage of this project, this FO-SHM sensing system was tested in the simulated harsh environment for its multi-parameter monitoring performance and high-temperature survivability.« less

Health condition identification of multi-stage planetary gearboxes using a mRVM-based method

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Liu, Zongyao; Wu, Xionghui; Li, Naipeng; Chen, Wu; Lin, Jing

2015-08-01

Multi-stage planetary gearboxes are widely applied in aerospace, automotive and heavy industries. Their key components, such as gears and bearings, can easily suffer from damage due to tough working environment. Health condition identification of planetary gearboxes aims to prevent accidents and save costs. This paper proposes a method based on multiclass relevance vector machine (mRVM) to identify health condition of multi-stage planetary gearboxes. In this method, a mRVM algorithm is adopted as a classifier, and two features, i.e. accumulative amplitudes of carrier orders (AACO) and energy ratio based on difference spectra (ERDS), are used as the input of the classifier to classify different health conditions of multi-stage planetary gearboxes. To test the proposed method, seven health conditions of a two-stage planetary gearbox are considered and vibration data is acquired from the planetary gearbox under different motor speeds and loading conditions. The results of three tests based on different data show that the proposed method obtains an improved identification performance and robustness compared with the existing method.

Driving under the influence of alcohol in Cali, Colombia: prevalence and consumption patterns, 2013.

PubMed

Bonilla-Escobar, Francisco J; Herrera-López, Martha L; Ortega-Lenis, Delia; Medina-Murillo, Jhon J; Fandiño-Losada, Andrés; Jaramillo-Molina, Ciro; Naranjo-Lujan, Salome; Izquierdo, Edda P; Vanlaar, Ward; Gutiérrez-Martínez, María I

2016-01-01

This study's goal was to establish the prevalence of driving under the influence of alcohol (DUI) and alcohol consumption patterns among drivers in Cali, Colombia, in 2013. A cross-sectional study based on a roadside survey using a stratified and multi-stage sampling design was developed. Thirty-two sites were chosen randomly for the selection of drivers who were then tested for blood alcohol concentration (BAC) and asked to participate in the survey. The prevalence of DUI was 0.88% (95% confidence intervals [95% CI] 0.26%-1.49%) with a lower prevalence when BAC was increasing. In addition, a higher prevalence was found during non-typical checkpoint hours (1.28, 95% CI -0.001%-0.03%). The overall prevalence is considered high, given the low alcohol consumption and vehicles per capita. Prevention measures are needed to reduce DUI during non-typical checkpoints and ongoing studies are required to monitor the trends and enable the assessment of interventions.

Prediction of binding poses to FXR using multi-targeted docking combined with molecular dynamics and enhanced sampling

NASA Astrophysics Data System (ADS)

Bhakat, Soumendranath; Åberg, Emil; Söderhjelm, Pär

2018-01-01

Advanced molecular docking methods often aim at capturing the flexibility of the protein upon binding to the ligand. In this study, we investigate whether instead a simple rigid docking method can be applied, if combined with multiple target structures to model the backbone flexibility and molecular dynamics simulations to model the sidechain and ligand flexibility. The methods are tested for the binding of 35 ligands to FXR as part of the first stage of the Drug Design Data Resource (D3R) Grand Challenge 2 blind challenge. The results show that the multiple-target docking protocol performs surprisingly well, with correct poses found for 21 of the ligands. MD simulations started on the docked structures are remarkably stable, but show almost no tendency of refining the structure closer to the experimentally found binding pose. Reconnaissance metadynamics enhances the exploration of new binding poses, but additional collective variables involving the protein are needed to exploit the full potential of the method.

Prediction of binding poses to FXR using multi-targeted docking combined with molecular dynamics and enhanced sampling.

PubMed

Bhakat, Soumendranath; Åberg, Emil; Söderhjelm, Pär

2018-01-01

Advanced molecular docking methods often aim at capturing the flexibility of the protein upon binding to the ligand. In this study, we investigate whether instead a simple rigid docking method can be applied, if combined with multiple target structures to model the backbone flexibility and molecular dynamics simulations to model the sidechain and ligand flexibility. The methods are tested for the binding of 35 ligands to FXR as part of the first stage of the Drug Design Data Resource (D3R) Grand Challenge 2 blind challenge. The results show that the multiple-target docking protocol performs surprisingly well, with correct poses found for 21 of the ligands. MD simulations started on the docked structures are remarkably stable, but show almost no tendency of refining the structure closer to the experimentally found binding pose. Reconnaissance metadynamics enhances the exploration of new binding poses, but additional collective variables involving the protein are needed to exploit the full potential of the method.

Clinical staging and operative reporting for multi-institutional trials in head and neck squamous cell carcinoma.

PubMed

Weymuller, E A

1997-12-01

A Strategic Planning Conference (jointly supported by NCI and NIDCD) was convened to consider potential improvements in surgical patient data for multi-institutional trials. The thesis underlying this project is that inadequacies in staging, pretreatment patient stratification, and the details of surgical resection may have obscured the detection of treatment effect. The goals of this project were multiple: (1) to consider the utility of new clinical stratification variables, (2) to increase the precision of tumor staging, and (3) to improve operative reporting for multi-institutional trials in head and neck cancer. The conference attendees came to a number of important conclusions: (1) TNM status is inadequate for describing head and neck cancer in a multi-institutional trial setting. A detailed anatomic reporting scheme is proposed; (2) comorbidity measures should be included as patient descriptors, especially those that meet the criteria "definitely important and easy to obtain"; (3) surgical reporting in multi-institutional trials should use a format that is compatible with computer analysis and use the same items as the revised (anatomic) staging system; (4) the surgeon should be personally responsible for data coding and should interact directly with the pathologist in marking the surgical specimen; (5) pathologic reporting should use an anatomic template identical to the staging and operative reporting formats.

Seafloor Topographic Analysis in Staged Ocean Resource Exploration

NASA Astrophysics Data System (ADS)

Ikeda, M.; Okawa, M.; Osawa, K.; Kadoshima, K.; Asakawa, E.; Sumi, T.

2017-12-01

J-MARES (Research and Development Partnership for Next Generation Technology of Marine Resources Survey, JAPAN) has been designing a low-expense and high-efficiency exploration system for seafloor hydrothermal massive sulfide deposits in "Cross-ministerial Strategic Innovation Promotion Program (SIP)" granted by the Cabinet Office, Government of Japan since 2014. We designed a method to focus mineral deposit prospective area in multi-stages (the regional survey, semi-detail survey and detail survey) by extracted topographic features of some well-known seafloor massive sulfide deposits from seafloor topographic analysis using seafloor topographic data acquired by the bathymetric survey. We applied this procedure to an area of interest more than 100km x 100km over Okinawa Trough, including some known seafloor massive sulfide deposits. In Addition, we tried to create a three-dimensional model of seafloor topography by SfM (Structure from Motion) technique using multiple image data of Chimney distributed around well-known seafloor massive sulfide deposit taken with Hi-Vision camera mounted on ROV in detail survey such as geophysical exploration. Topographic features of Chimney was extracted by measuring created three-dimensional model. As the result, it was possible to estimate shape of seafloor sulfide such as Chimney to be mined by three-dimensional model created from image data taken with camera mounted on ROV. In this presentation, we will discuss about focusing mineral deposit prospective area in multi-stages by seafloor topographic analysis using seafloor topographic data in exploration system for seafloor massive sulfide deposit and also discuss about three-dimensional model of seafloor topography created from seafloor image data taken with ROV.

Design of a Telescopic Linear Actuator Based on Hollow Shape Memory Springs

NASA Astrophysics Data System (ADS)

Spaggiari, Andrea; Spinella, Igor; Dragoni, Eugenio

2011-07-01

Shape memory alloys (SMAs) are smart materials exploited in many applications to build actuators with high power to mass ratio. Typical SMA drawbacks are: wires show poor stroke and excessive length, helical springs have limited mechanical bandwidth and high power consumption. This study is focused on the design of a large-scale linear SMA actuator conceived to maximize the stroke while limiting the overall size and the electric consumption. This result is achieved by adopting for the actuator a telescopic multi-stage architecture and using SMA helical springs with hollow cross section to power the stages. The hollow geometry leads to reduced axial size and mass of the actuator and to enhanced working frequency while the telescopic design confers to the actuator an indexable motion, with a number of different displacements being achieved through simple on-off control strategies. An analytical thermo-electro-mechanical model is developed to optimize the device. Output stroke and force are maximized while total size and power consumption are simultaneously minimized. Finally, the optimized actuator, showing good performance from all these points of view, is designed in detail.

Comparing Dynamic Treatment Regimes Using Repeated-Measures Outcomes: Modeling Considerations in SMART Studies

PubMed Central

Lu, Xi; Nahum-Shani, Inbal; Kasari, Connie; Lynch, Kevin G.; Oslin, David W.; Pelham, William E.; Fabiano, Gregory; Almirall, Daniel

2016-01-01

A dynamic treatment regime (DTR) is a sequence of decision rules, each of which recommends a treatment based on a patient’s past and current health status. Sequential, multiple assignment, randomized trials (SMARTs) are multi-stage trial designs that yield data specifically for building effective DTRs. Modeling the marginal mean trajectories of a repeated-measures outcome arising from a SMART presents challenges, because traditional longitudinal models used for randomized clinical trials do not take into account the unique design features of SMART. We discuss modeling considerations for various forms of SMART designs, emphasizing the importance of considering the timing of repeated measures in relation to the treatment stages in a SMART. For illustration, we use data from three SMART case studies with increasing level of complexity, in autism, child attention deficit hyperactivity disorder (ADHD), and adult alcoholism. In all three SMARTs we illustrate how to accommodate the design features along with the timing of the repeated measures when comparing DTRs based on mean trajectories of the repeated-measures outcome. PMID:26638988

Comparing dynamic treatment regimes using repeated-measures outcomes: modeling considerations in SMART studies.

PubMed

Lu, Xi; Nahum-Shani, Inbal; Kasari, Connie; Lynch, Kevin G; Oslin, David W; Pelham, William E; Fabiano, Gregory; Almirall, Daniel

2016-05-10

A dynamic treatment regime (DTR) is a sequence of decision rules, each of which recommends a treatment based on a patient's past and current health status. Sequential, multiple assignment, randomized trials (SMARTs) are multi-stage trial designs that yield data specifically for building effective DTRs. Modeling the marginal mean trajectories of a repeated-measures outcome arising from a SMART presents challenges, because traditional longitudinal models used for randomized clinical trials do not take into account the unique design features of SMART. We discuss modeling considerations for various forms of SMART designs, emphasizing the importance of considering the timing of repeated measures in relation to the treatment stages in a SMART. For illustration, we use data from three SMART case studies with increasing level of complexity, in autism, child attention deficit hyperactivity disorder, and adult alcoholism. In all three SMARTs, we illustrate how to accommodate the design features along with the timing of the repeated measures when comparing DTRs based on mean trajectories of the repeated-measures outcome. Copyright © 2015 John Wiley & Sons, Ltd.

Planning and processing multistage samples with a computer program—MUST.

Treesearch

John W. Hazard; Larry E. Stewart

1974-01-01

A computer program was written to handle multistage sampling designs in insect populations. It is, however, general enough to be used for any population where the number of stages does not exceed three. The program handles three types of sampling situations, all of which assume equal probability sampling. Option 1 takes estimates of sample variances, costs, and either...

Individual, Familial, Friends-Related and Contextual Predictors of Early Sexual Intercourse

ERIC Educational Resources Information Center

Boislard P., Marie-Aude; Poulin, Francois

2011-01-01

This study examined the unique and simultaneous contribution of adolescents' characteristics, parent-child relationship and friends' characteristics on early sexual intercourse, while accounting for family status. A longitudinal multi-sample design was used. The first sample was recruited in a suburban context (n = 265; 62% girls) and the second…

Multipurpose floating platform for hyperspectral imaging, sampling and sensing of surface water sources used in irrigation and recreation

USDA-ARS?s Scientific Manuscript database

The objective of this work was to design, construct, and test the self-propelled aquatic platform for imaging, multi-tier water sampling, water quality sensing, and depth profiling to document microbial content and environmental covariates in the interior of irrigation ponds and reservoirs. The plat...

Maximum type 1 error rate inflation in multiarmed clinical trials with adaptive interim sample size modifications.

PubMed

Graf, Alexandra C; Bauer, Peter; Glimm, Ekkehard; Koenig, Franz

2014-07-01

Sample size modifications in the interim analyses of an adaptive design can inflate the type 1 error rate, if test statistics and critical boundaries are used in the final analysis as if no modification had been made. While this is already true for designs with an overall change of the sample size in a balanced treatment-control comparison, the inflation can be much larger if in addition a modification of allocation ratios is allowed as well. In this paper, we investigate adaptive designs with several treatment arms compared to a single common control group. Regarding modifications, we consider treatment arm selection as well as modifications of overall sample size and allocation ratios. The inflation is quantified for two approaches: a naive procedure that ignores not only all modifications, but also the multiplicity issue arising from the many-to-one comparison, and a Dunnett procedure that ignores modifications, but adjusts for the initially started multiple treatments. The maximum inflation of the type 1 error rate for such types of design can be calculated by searching for the "worst case" scenarios, that are sample size adaptation rules in the interim analysis that lead to the largest conditional type 1 error rate in any point of the sample space. To show the most extreme inflation, we initially assume unconstrained second stage sample size modifications leading to a large inflation of the type 1 error rate. Furthermore, we investigate the inflation when putting constraints on the second stage sample sizes. It turns out that, for example fixing the sample size of the control group, leads to designs controlling the type 1 error rate. © 2014 The Author. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multi-Source Multi-Target Dictionary Learning for Prediction of Cognitive Decline.

PubMed

Zhang, Jie; Li, Qingyang; Caselli, Richard J; Thompson, Paul M; Ye, Jieping; Wang, Yalin

2017-06-01

Alzheimer's Disease (AD) is the most common type of dementia. Identifying correct biomarkers may determine pre-symptomatic AD subjects and enable early intervention. Recently, Multi-task sparse feature learning has been successfully applied to many computer vision and biomedical informatics researches. It aims to improve the generalization performance by exploiting the shared features among different tasks. However, most of the existing algorithms are formulated as a supervised learning scheme. Its drawback is with either insufficient feature numbers or missing label information. To address these challenges, we formulate an unsupervised framework for multi-task sparse feature learning based on a novel dictionary learning algorithm. To solve the unsupervised learning problem, we propose a two-stage Multi-Source Multi-Target Dictionary Learning (MMDL) algorithm. In stage 1, we propose a multi-source dictionary learning method to utilize the common and individual sparse features in different time slots. In stage 2, supported by a rigorous theoretical analysis, we develop a multi-task learning method to solve the missing label problem. Empirical studies on an N = 3970 longitudinal brain image data set, which involves 2 sources and 5 targets, demonstrate the improved prediction accuracy and speed efficiency of MMDL in comparison with other state-of-the-art algorithms.

Saturn V First Stage Leaves the Dynamic Test Stand

NASA Technical Reports Server (NTRS)

1967-01-01

This photo shows the Saturn V first stage being lowered to the ground following a successful test to determine the effects of continual vibrations simulating the effects of an actual launch. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

The impact of study design and diagnostic approach in a large multi-centre ADHD study. Part 1: ADHD symptom patterns

PubMed Central

2011-01-01

Background The International Multi-centre ADHD Genetics (IMAGE) project with 11 participating centres from 7 European countries and Israel has collected a large behavioural and genetic database for present and future research. Behavioural data were collected from 1068 probands with the combined type of attention deficit/hyperactivity disorder (ADHD-CT) and 1446 'unselected' siblings. The aim was to analyse the IMAGE sample with respect to demographic features (gender, age, family status, and recruiting centres) and psychopathological characteristics (diagnostic subtype, symptom frequencies, age at symptom detection, and comorbidities). A particular focus was on the effects of the study design and the diagnostic procedure on the homogeneity of the sample in terms of symptom-based behavioural data, and potential consequences for further analyses based on these data. Methods Diagnosis was based on the Parental Account of Childhood Symptoms (PACS) interview and the DSM-IV items of the Conners' teacher questionnaire. Demographics of the full sample and the homogeneity of a subsample (all probands) were analysed by using robust statistical procedures which were adjusted for unequal sample sizes and skewed distributions. These procedures included multi-way analyses based on trimmed means and winsorised variances as well as bootstrapping. Results Age and proband/sibling ratios differed between participating centres. There was no significant difference in the distribution of gender between centres. There was a significant interaction between age and centre for number of inattentive, but not number of hyperactive symptoms. Higher ADHD symptom frequencies were reported by parents than teachers. The diagnostic symptoms differed from each other in their frequencies. The face-to-face interview was more sensitive than the questionnaire. The differentiation between ADHD-CT probands and unaffected siblings was mainly due to differences in hyperactive/impulsive symptoms. Conclusions Despite a symptom-based standardized inclusion procedure according to DSM-IV criteria with defined symptom thresholds, centres may differ markedly in probands' ADHD symptom frequencies. Both the diagnostic procedure and the multi-centre design influence the behavioural characteristics of a sample and, thus, may bias statistical analyses, particularly in genetic or neurobehavioral studies. PMID:21473745

Numerical study of a VM type multi-bypass pulse tube cryocooler operating at 4K

NASA Astrophysics Data System (ADS)

Pan, Changzhao; Zhang, Tong; Wang, Jue; Chen, Liubiao; Cui, Chen; Wang, Junjie; Zhou, Yuan

2017-12-01

VM cryocooler is one kind of Stirling type cryocooler working at low frequency. At present, we have obtained the liquid helium temperature by using a two-stage VM/pulse tube hybrid cryocooler. As a new kind of 4K cryocooler, there are many aspects need to be studied and optimized in detail. In order to reducing the vibration and improving the stability of this cryocooler, a pulse tube cryocooler was designed to get rid of the displacer in the first stage. This paper presents a detail numerical investigation on this pulse tube cryocooler by using the SAGE software. The low temperature phase shifters were adopted in this cryocooler, which were low temperature gas reservoir, low temperature double-inlet and multi-bypass. After optimizing, the structure parameters and the best diameters of orifice, multi-bypass and double-inlet were obtained. With the pressure ratio of about 1.6 and operating frequency 2Hz, this cryocooler could supply above 40mW cooling power at 4.2K, and the total input power needs no more than 60W at 77K. Based on the highest efficiency of 77K high capacity cryocooler, the overall efficiency of this VM type pulse tube cryocooler is above 0.5% relative Carnot efficient.

Feasibility Studies for Production of Pellet Grade Concentrate from Sub Grade Iron Ore Using Multi Gravity Separator

NASA Astrophysics Data System (ADS)

Rao, Gottumukkala Venkateswara; Markandeya, R.; Kumar, Rajan

2018-04-01

An attempt has been made to utilise Sub Grade Iron Ore by producing pellet grade concentrate from Deposit 5, Bacheli Complex, Bailadila, Chhattisgarh, India. The `as received' Run of Mine (ROM) sample assayed 40.80% Fe, 40.90% SiO2. Mineralogical studies indicated that the main ore mineral is Hematite and lone gangue mineral is Quartz. Mineral liberation studies indicated that, the ore mineral Hematite and gangue mineral Quartz are getting liberated below 100 microns. The stage crushed and ground sample was subjected to concentration by using a Multi Gravity Separator (MGS). Rougher Multi Gravity Separation (MGS) experimental results were optimised to recover highest possible iron values. A concentrate of 55.80% Fe with a yield of 61.73% by weight with a recovery of 84.42% Iron values was obtained in rougher MGS concentrate. Further experiments were carried out with rougher MGS concentrate to produce a concentrate suitable for commercial grade pellet concentrate. It was proved that a concentrate assaying 66.67% Fe, 3.12% SiO2 with an yield of 45.08% by weight and with a recovery of 73.67% iron values in the concentrate.

Experimental early-stage coalification of a peat sample and a peatified wood sample from Indonesia

USGS Publications Warehouse

Orem, W.H.; Neuzil, S.G.; Lerch, H.E.; Cecil, C.B.

1996-01-01

Experimental coalification of a peat sample and a buried wood sample from domed peat deposits in Indonesia was carried out to examine chemical structural changes in organic matter during early-stage coalification. The experiment (125 C, 408 atm lithostatic pressure, and 177 atm fluid pressure for 75 days) was designed to maintain both lithostatic and fluid pressure on the sample, but allow by-products that may retard coalification to escape. We refer to this design as a geologically open system. Changes in the elemental composition, and 13C NMR and FTIR spectra of the peat and wood after experimental coalification suggest preferential thermal decomposition of O-containing aliphatic organic compounds (probably cellulose) during early-stage coalification. The elemental compositions and 13C NMR spectra of the experimentally coalified peat and wood were generally similar to those of Miocene coal and coalified wood samples from Indonesia. Yields of lignin phenols in the peat and wood samples decreased following experimental coalification; the wood sample exhibited a larger change. Lignin phenol yields from the experimentally coalified peat and wood were comparable to yields of lignin phenols from Miocene Indonesian lignite and coalified wood. Changes in syringyl/vanillyl and p-hydroxy/vanillyl ratios suggest direct demethoxylation as a secondary process to demethylation of methoxyl groups during early coalification, and changes in lignin phenol yields and acid/aldehyde ratios point to a coupling between demethoxylation processes and reactions in the alkyl side chain bonds of the ??-carbon in lignin phenols.

Multi-stage separations based on dielectrophoresis

DOEpatents

Mariella, Jr., Raymond P.

2004-07-13

A system utilizing multi-stage traps based on dielectrophoresis. Traps with electrodes arranged transverse to the flow and traps with electrodes arranged parallel to the flow with combinations of direct current and alternating voltage are used to trap, concentrate, separate, and/or purify target particles.

A SMALL WATERSHED CHARACTERIZATION, CLASSIFICATION, AND ASSESSMENT FOR WEST VIRGINIA UTILIZING EMAP DESIGN AND TOOLS

EPA Science Inventory

A multi-objective sampling design has been implemented through R-EMAP support of a cooperative agreement with the state of West Virginia. Goals of the project include: 1) development and testing of a temperature-adjusted fish IBI for the Central Appalachian Plateau and Western Al...

Cross-stage immunity for malaria vaccine development.

PubMed

Nahrendorf, Wiebke; Scholzen, Anja; Sauerwein, Robert W; Langhorne, Jean

2015-12-22

A vaccine against malaria is urgently needed for control and eventual eradication. Different approaches are pursued to induce either sterile immunity directed against pre-erythrocytic parasites or to mimic naturally acquired immunity by controlling blood-stage parasite densities and disease severity. Pre-erythrocytic and blood-stage malaria vaccines are often seen as opposing tactics, but it is likely that they have to be combined into a multi-stage malaria vaccine to be optimally safe and effective. Since many antigenic targets are shared between liver- and blood-stage parasites, malaria vaccines have the potential to elicit cross-stage protection with immune mechanisms against both stages complementing and enhancing each other. Here we discuss evidence from pre-erythrocytic and blood-stage subunit and whole parasite vaccination approaches that show that protection against malaria is not necessarily stage-specific. Parasites arresting at late liver-stages especially, can induce powerful blood-stage immunity, and similarly exposure to blood-stage parasites can afford pre-erythrocytic immunity. The incorporation of a blood-stage component into a multi-stage malaria vaccine would hence not only combat breakthrough infections in the blood should the pre-erythrocytic component fail to induce sterile protection, but would also actively enhance the pre-erythrocytic potency of this vaccine. We therefore advocate that future studies should concentrate on the identification of cross-stage protective malaria antigens, which can empower multi-stage malaria vaccine development. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Design and Initial Results of a Multi-Phase Randomized Trial of Ceftriaxone in Amyotrophic Lateral Sclerosis

PubMed Central

Berry, James D.; Shefner, Jeremy M.; Conwit, Robin; Schoenfeld, David; Keroack, Myles; Felsenstein, Donna; Krivickas, Lisa; David, William S.; Vriesendorp, Francine; Pestronk, Alan; Caress, James B.; Katz, Jonathan; Simpson, Ericka; Rosenfeld, Jeffrey; Pascuzzi, Robert; Glass, Jonathan; Rezania, Kourosh; Rothstein, Jeffrey D.; Greenblatt, David J.; Cudkowicz, Merit E.

2013-01-01

Objectives Ceftriaxone increases expression of the astrocytic glutamate transporter, EAAT2, which might protect from glutamate-mediated excitotoxicity. A trial using a novel three stage nonstop design, incorporating Phases I-III, tested ceftriaxone in ALS. Stage 1 determined the cerebrospinal fluid pharmacokinetics of ceftriaxone in subjects with ALS. Stage 2 evaluated safety and tolerability for 20-weeks. Analysis of the pharmacokinetics, tolerability, and safety was used to determine the ceftriaxone dosage for Stage 3 efficacy testing. Methods In Stage 1, 66 subjects at ten clinical sites were enrolled and randomized equally into three study groups receiving intravenous placebo, ceftriaxone 2 grams daily or ceftriaxone 4 grams daily divided BID. Participants provided serum and cerebrospinal fluid for pharmacokinetic analysis on study day 7. Participants continued their assigned treatment in Stage 2. The Data and Safety Monitoring Board (DSMB) reviewed the data after the last participants completed 20 weeks on study drug. Results Stage 1 analysis revealed linear pharmacokinetics, and CSF trough levels for both dosage levels exceeding the pre-specified target trough level of 1 µM (0.55 µg/mL). Tolerability (Stages 1 and 2) results showed that ceftriaxone at dosages up to 4 grams/day was well tolerated at 20 weeks. Biliary adverse events were more common with ceftriaxone but not dose-dependent and improved with ursodeoxycholic (ursodiol) therapy. Conclusions The goals of Stages 1 and 2 of the ceftriaxone trial were successfully achieved. Based on the pre-specified decision rules, the DSMB recommended the use of ceftriaxone 4 g/d (divided BID) for Stage 3, which recently closed. Trial Registration ClinicalTrials.gov NCT00349622. PMID:23613806

Robustness-Based Design Optimization Under Data Uncertainty

NASA Technical Reports Server (NTRS)

Zaman, Kais; McDonald, Mark; Mahadevan, Sankaran; Green, Lawrence

2010-01-01

This paper proposes formulations and algorithms for design optimization under both aleatory (i.e., natural or physical variability) and epistemic uncertainty (i.e., imprecise probabilistic information), from the perspective of system robustness. The proposed formulations deal with epistemic uncertainty arising from both sparse and interval data without any assumption about the probability distributions of the random variables. A decoupled approach is proposed in this paper to un-nest the robustness-based design from the analysis of non-design epistemic variables to achieve computational efficiency. The proposed methods are illustrated for the upper stage design problem of a two-stage-to-orbit (TSTO) vehicle, where the information on the random design inputs are only available as sparse point and/or interval data. As collecting more data reduces uncertainty but increases cost, the effect of sample size on the optimality and robustness of the solution is also studied. A method is developed to determine the optimal sample size for sparse point data that leads to the solutions of the design problem that are least sensitive to variations in the input random variables.

Using variance components to estimate power in a hierarchically nested sampling design improving monitoring of larval Devils Hole pupfish

USGS Publications Warehouse

Dzul, Maria C.; Dixon, Philip M.; Quist, Michael C.; Dinsomore, Stephen J.; Bower, Michael R.; Wilson, Kevin P.; Gaines, D. Bailey

2013-01-01

We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHP larvae on nine plots were counted plot by plot. Statistical analysis of larval abundance included three components: (1) evaluation of power from various sample size combinations, (2) comparison of power in fixed and random plot designs, and (3) assessment of yearly differences in the power of the survey. Results indicated that increasing the sample size at the lowest level of sampling represented the most realistic option to increase the survey's power, fixed plot designs had greater power than random plot designs, and the power of the larval survey varied by year. This study provides an example of how monitoring efforts may benefit from coupling variance components estimation with power analysis to assess sampling design.

An analytic-geometric model of the effect of spherically distributed injection errors for Galileo and Ulysses spacecraft - The multi-stage problem

NASA Technical Reports Server (NTRS)

Longuski, James M.; Mcronald, Angus D.

1988-01-01

In previous work the problem of injecting the Galileo and Ulysses spacecraft from low earth orbit into their respective interplanetary trajectories has been discussed for the single stage (Centaur) vehicle. The central issue, in the event of spherically distributed injection errors, is what happens to the vehicle? The difficulties addressed in this paper involve the multi-stage problem since both Galileo and Ulysses will be utilizing the two-stage IUS system. Ulysses will also include a third stage: the PAM-S. The solution is expressed in terms of probabilities for total percentage of escape, orbit decay and reentry trajectories. Analytic solutions are found for Hill's Equations of Relative Motion (more recently called Clohessy-Wiltshire Equations) for multi-stage injections. These solutions are interpreted geometrically on the injection sphere. The analytic-geometric models compare well with numerical solutions, provide insight into the behavior of trajectories mapped on the injection sphere and simplify the numerical two-dimensional search for trajectory families.

End-pumped 300 W continuous-wave ytterbium-doped all-fiber laser with master oscillator multi-stage power amplifiers configuration.

PubMed

Yin, Shupeng; Yan, Ping; Gong, Mali

2008-10-27

An end-pumped ytterbium-doped all-fiber laser with 300 W output in continuous regime was reported, which was based on master oscillator multi-stage power amplifiers configuration. Monolithic fiber laser system consisted of an oscillator stage and two amplifier stages. Total optical-optical efficiency of monolithic fiber laser was approximately 65%, corresponding to 462 W of pump power coupled into laser system. We proposed a new method to connect power amplifier stage, which was crucial for the application of end-pumped combiner in high power MOPAs all-fiber laser.

Thermodynamics and Kinetics of Prenucleation Clusters, Classical and Non-Classical Nucleation

PubMed Central

Zahn, Dirk

2015-01-01

Recent observations of prenucleation species and multi-stage crystal nucleation processes challenge the long-established view on the thermodynamics of crystal formation. Here, we review and generalize extensions to classical nucleation theory. Going beyond the conventional implementation as has been used for more than a century now, nucleation inhibitors, precursor clusters and non-classical nucleation processes are rationalized as well by analogous concepts based on competing interface and bulk energy terms. This is illustrated by recent examples of species formed prior to/instead of crystal nucleation and multi-step nucleation processes. Much of the discussed insights were obtained from molecular simulation using advanced sampling techniques, briefly summarized herein for both nucleation-controlled and diffusion-controlled aggregate formation. PMID:25914369

Computer code for preliminary sizing analysis of axial-flow turbines

NASA Technical Reports Server (NTRS)

Glassman, Arthur J.

1992-01-01

This mean diameter flow analysis uses a stage average velocity diagram as the basis for the computational efficiency. Input design requirements include power or pressure ratio, flow rate, temperature, pressure, and rotative speed. Turbine designs are generated for any specified number of stages and for any of three types of velocity diagrams (symmetrical, zero exit swirl, or impulse) or for any specified stage swirl split. Exit turning vanes can be included in the design. The program output includes inlet and exit annulus dimensions, exit temperature and pressure, total and static efficiencies, flow angles, and last stage absolute and relative Mach numbers. An analysis is presented along with a description of the computer program input and output with sample cases. The analysis and code presented herein are modifications of those described in NASA-TN-D-6702. These modifications improve modeling rigor and extend code applicability.

Disease detection in sugar beet fields: a multi-temporal and multi-sensoral approach on different scales

NASA Astrophysics Data System (ADS)

Mahlein, Anne-Katrin; Hillnhütter, Christian; Mewes, Thorsten; Scholz, Christine; Steiner, Ulrike; Dehne, Heinz-Willhelm; Oerke, Erich-Christian

2009-09-01

Depending on environmental factors fungal diseases of crops are often distributed heterogeneously in fields. Precision agriculture in plant protection implies a targeted fungicide application adjusted these field heterogeneities. Therefore an understanding of the spatial and temporal occurrence of pathogens is elementary. As shown in previous studies, remote sensing techniques can be used to detect and observe spectral anomalies in the field. In 2008, a sugar beet field site was observed at different growth stages of the crop using different remote sensing techniques. The experimental field site consisted of two treatments. One plot was sprayed with a fungicide to avoid fungal infections. In order to obtain sugar beet plants infected with foliar diseases the other plot was not sprayed. Remote sensing data were acquired from the high-resolution airborne hyperspectral imaging ROSIS in July 2008 at sugar beet growth stage 39 and from the HyMap sensor systems in August 2008 at sugar beet growth stage 45, respectively. Additionally hyperspectral signatures of diseased and non-diseased sugar beet plants were measured with a non-imaging hand held spectroradiometer at growth stage 49 in September. Ground truth data, in particular disease severity were collected at 50 sampling points in the field. Changes of reflection rates were related to disease severity increasing with time. Erysiphe betae causing powdery mildew was the most frequent leaf pathogen. A classification of healthy and diseased sugar beets in the field was possible by using hyperspectral vegetation indices calculated from canopy reflectance.

A Risk-Constrained Multi-Stage Decision Making Approach to the Architectural Analysis of Mars Missions

NASA Technical Reports Server (NTRS)

Kuwata, Yoshiaki; Pavone, Marco; Balaram, J. (Bob)

2012-01-01

This paper presents a novel risk-constrained multi-stage decision making approach to the architectural analysis of planetary rover missions. In particular, focusing on a 2018 Mars rover concept, which was considered as part of a potential Mars Sample Return campaign, we model the entry, descent, and landing (EDL) phase and the rover traverse phase as four sequential decision-making stages. The problem is to find a sequence of divert and driving maneuvers so that the rover drive is minimized and the probability of a mission failure (e.g., due to a failed landing) is below a user specified bound. By solving this problem for several different values of the model parameters (e.g., divert authority), this approach enables rigorous, accurate and systematic trade-offs for the EDL system vs. the mobility system, and, more in general, cross-domain trade-offs for the different phases of a space mission. The overall optimization problem can be seen as a chance-constrained dynamic programming problem, with the additional complexity that 1) in some stages the disturbances do not have any probabilistic characterization, and 2) the state space is extremely large (i.e, hundreds of millions of states for trade-offs with high-resolution Martian maps). To this purpose, we solve the problem by performing an unconventional combination of average and minimax cost analysis and by leveraging high efficient computation tools from the image processing community. Preliminary trade-off results are presented.

Relationship between happiness and tobacco smoking among high school students.

PubMed

Ataeiasl, Maryam; Sarbakhsh, Parvin; Dadashzadeh, Hossein; Augner, Christoph; Anbarlouei, Masoumeh; Mohammadpoorasl, Asghar

2018-01-01

Recent research has described negative relationship between happiness and habitual smoking among adolescents. No study of this relationship has been conducted among Iranian adolescents. The aim of the present study was to characterize the relationship between happiness and cigarette or hookah smoking among a sample of high school students. A sample of 1,161 10th-grade students in Tabriz (northwest Iran) was selected by multi-stage proportional cluster sampling. Participants completed a self-administered multiple-choice questionnaire including information on cigarette smoking, hookah smoking, happiness score, substance abuse, self-injury, general risk-taking behavior, attitudes towards smoking, socioeconomic information, and demographic characteristics. An ordinal logistic regression model was used for data analysis. It was found that 5.9 and 5.0% of students were regular cigarette smokers and regular hookah smokers, respectively. After controlling for potential confounders, higher happiness scores were found to protect students against more advanced stages of cigarette smoking (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97 to 0.99; p=0.013). However, no significant relationship was found between happiness scores and hookah smoking status (OR, 1.01; 95% CI, 0.97 to 1.02; p=0.523). Happiness scores were associated with less advanced stages of habitual cigarette smoking among high school students. Our findings underscore the necessity of conducting longitudinal or interventional studies aiming to determine the effects of enhancing happiness on preventing the transition through the stages of cigarette and hookah smoking.

Grouped fuzzy SVM with EM-based partition of sample space for clustered microcalcification detection.

PubMed

Wang, Huiya; Feng, Jun; Wang, Hongyu

2017-07-20

Detection of clustered microcalcification (MC) from mammograms plays essential roles in computer-aided diagnosis for early stage breast cancer. To tackle problems associated with the diversity of data structures of MC lesions and the variability of normal breast tissues, multi-pattern sample space learning is required. In this paper, a novel grouped fuzzy Support Vector Machine (SVM) algorithm with sample space partition based on Expectation-Maximization (EM) (called G-FSVM) is proposed for clustered MC detection. The diversified pattern of training data is partitioned into several groups based on EM algorithm. Then a series of fuzzy SVM are integrated for classification with each group of samples from the MC lesions and normal breast tissues. From DDSM database, a total of 1,064 suspicious regions are selected from 239 mammography, and the measurement of Accuracy, True Positive Rate (TPR), False Positive Rate (FPR) and EVL = TPR* 1-FPR are 0.82, 0.78, 0.14 and 0.72, respectively. The proposed method incorporates the merits of fuzzy SVM and multi-pattern sample space learning, decomposing the MC detection problem into serial simple two-class classification. Experimental results from synthetic data and DDSM database demonstrate that our integrated classification framework reduces the false positive rate significantly while maintaining the true positive rate.

An iterative and targeted sampling design informed by habitat suitability models for detecting focal plant species over extensive areas.

PubMed

Wang, Ophelia; Zachmann, Luke J; Sesnie, Steven E; Olsson, Aaryn D; Dickson, Brett G

2014-01-01

Prioritizing areas for management of non-native invasive plants is critical, as invasive plants can negatively impact plant community structure. Extensive and multi-jurisdictional inventories are essential to prioritize actions aimed at mitigating the impact of invasions and changes in disturbance regimes. However, previous work devoted little effort to devising sampling methods sufficient to assess the scope of multi-jurisdictional invasion over extensive areas. Here we describe a large-scale sampling design that used species occurrence data, habitat suitability models, and iterative and targeted sampling efforts to sample five species and satisfy two key management objectives: 1) detecting non-native invasive plants across previously unsampled gradients, and 2) characterizing the distribution of non-native invasive plants at landscape to regional scales. Habitat suitability models of five species were based on occurrence records and predictor variables derived from topography, precipitation, and remotely sensed data. We stratified and established field sampling locations according to predicted habitat suitability and phenological, substrate, and logistical constraints. Across previously unvisited areas, we detected at least one of our focal species on 77% of plots. In turn, we used detections from 2011 to improve habitat suitability models and sampling efforts in 2012, as well as additional spatial constraints to increase detections. These modifications resulted in a 96% detection rate at plots. The range of habitat suitability values that identified highly and less suitable habitats and their environmental conditions corresponded to field detections with mixed levels of agreement. Our study demonstrated that an iterative and targeted sampling framework can address sampling bias, reduce time costs, and increase detections. Other studies can extend the sampling framework to develop methods in other ecosystems to provide detection data. The sampling methods implemented here provide a meaningful tool when understanding the potential distribution and habitat of species over multi-jurisdictional and extensive areas is needed for achieving management objectives.

An Iterative and Targeted Sampling Design Informed by Habitat Suitability Models for Detecting Focal Plant Species over Extensive Areas

PubMed Central

Wang, Ophelia; Zachmann, Luke J.; Sesnie, Steven E.; Olsson, Aaryn D.; Dickson, Brett G.

2014-01-01

Prioritizing areas for management of non-native invasive plants is critical, as invasive plants can negatively impact plant community structure. Extensive and multi-jurisdictional inventories are essential to prioritize actions aimed at mitigating the impact of invasions and changes in disturbance regimes. However, previous work devoted little effort to devising sampling methods sufficient to assess the scope of multi-jurisdictional invasion over extensive areas. Here we describe a large-scale sampling design that used species occurrence data, habitat suitability models, and iterative and targeted sampling efforts to sample five species and satisfy two key management objectives: 1) detecting non-native invasive plants across previously unsampled gradients, and 2) characterizing the distribution of non-native invasive plants at landscape to regional scales. Habitat suitability models of five species were based on occurrence records and predictor variables derived from topography, precipitation, and remotely sensed data. We stratified and established field sampling locations according to predicted habitat suitability and phenological, substrate, and logistical constraints. Across previously unvisited areas, we detected at least one of our focal species on 77% of plots. In turn, we used detections from 2011 to improve habitat suitability models and sampling efforts in 2012, as well as additional spatial constraints to increase detections. These modifications resulted in a 96% detection rate at plots. The range of habitat suitability values that identified highly and less suitable habitats and their environmental conditions corresponded to field detections with mixed levels of agreement. Our study demonstrated that an iterative and targeted sampling framework can address sampling bias, reduce time costs, and increase detections. Other studies can extend the sampling framework to develop methods in other ecosystems to provide detection data. The sampling methods implemented here provide a meaningful tool when understanding the potential distribution and habitat of species over multi-jurisdictional and extensive areas is needed for achieving management objectives. PMID:25019621

Emergency department injury surveillance and aetiological research: bridging the gap with the two-stage case-control study design.

PubMed

Hagel, Brent E

2011-04-01

To provide an overview of the two-stage case-control study design and its potential application to ED injury surveillance data and to apply this approach to published ED data on the relation between brain injury and bicycle helmet use. Relevant background is presented on injury aetiology and case-control methodology with extension to the two-stage case-control design in the context of ED injury surveillance. The design is then applied to data from a published case-control study of the relation between brain injury and bicycle helmet use with motor vehicle involvement considered as a potential confounder. Taking into account the additional sampling at the second stage, the adjusted and corrected odds ratio and 95% confidence interval for the brain injury-helmet use relation is presented and compared with the estimate from the entire original dataset. Contexts where the two-stage case-control study design might be most appropriately applied to ED injury surveillance data are suggested. The adjusted odds ratio for the relation between brain injury and bicycle helmet use based on all data (n = 2833) from the original study was 0.34 (95% CI 0.25 to 0.46) compared with an estimate from a two-stage case-control design of 0.35 (95% CI 0.25 to 0.48) using only a fraction of the original subjects (n = 480). Application of the two-stage case-control study design to ED injury surveillance data has the potential to dramatically reduce study time and resource costs with acceptable losses in statistical efficiency.

Design Optimization of a Centrifugal Fan with Splitter Blades

NASA Astrophysics Data System (ADS)

Heo, Man-Woong; Kim, Jin-Hyuk; Kim, Kwang-Yong

2015-05-01

Multi-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.

Sample Size for Tablet Compression and Capsule Filling Events During Process Validation.

PubMed

Charoo, Naseem Ahmad; Durivage, Mark; Rahman, Ziyaur; Ayad, Mohamad Haitham

2017-12-01

During solid dosage form manufacturing, the uniformity of dosage units (UDU) is ensured by testing samples at 2 stages, that is, blend stage and tablet compression or capsule/powder filling stage. The aim of this work is to propose a sample size selection approach based on quality risk management principles for process performance qualification (PPQ) and continued process verification (CPV) stages by linking UDU to potential formulation and process risk factors. Bayes success run theorem appeared to be the most appropriate approach among various methods considered in this work for computing sample size for PPQ. The sample sizes for high-risk (reliability level of 99%), medium-risk (reliability level of 95%), and low-risk factors (reliability level of 90%) were estimated to be 299, 59, and 29, respectively. Risk-based assignment of reliability levels was supported by the fact that at low defect rate, the confidence to detect out-of-specification units would decrease which must be supplemented with an increase in sample size to enhance the confidence in estimation. Based on level of knowledge acquired during PPQ and the level of knowledge further required to comprehend process, sample size for CPV was calculated using Bayesian statistics to accomplish reduced sampling design for CPV. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Binge drinking as a risk factor for violence among secondary school students in a nationally representative sample in Puerto Rico.

PubMed

Reyes-Pulliza, Juan Carlos; Rodríguez-Figueroa, Linnette; Moscoso-Álvarez, Margarita R; Colón, Héctor; Cotto-Negrón, Coral; Rivera, Laura; Irizarry-Pérez, Marisela

2015-03-01

The objective of this study was to determine the association between binge drinking and violence in a representative sample of secondary-school students in Puerto Rico. Consulta Juvenil VII (a biennial survey of school-aged youths in Puerto Rico) has a representative sample of adolescent students in Puerto Rico. A multi-stage stratified cluster sampling design was used. The sampling frame of Consulta Juvenil VII includes all the public and private schools registered with the Department of Education and the Council of General Education in Puerto Rico. The study utilizes a self-administered questionnaire that was translated and adapted from the "Student Survey of Risk and Protective Factors and Prevalence of Alcohol, Tobacco, and Other Drug Use". "Binge drinking" was defined as having 5 or more alcoholic drinks in a row during the 30 days preceding the survey. Almost 20% of the sample members reported that at least 1 instance of binge drinking had taken place during the 2 weeks prior to the survey (17.7%). After controlling for gender, age, school level, the type of system, and the parents' educational levels, the odds of a given binge drinker reporting violent behaviors were 5 times greater than the odds among non-binge drinkers (OR: 5.6; 95% CI: 4.7-6.7). The study shows an association between binge drinking and violence in Puerto Rican adolescents, indicating that Hispanic youths who abuse alcohol may be at increased risk of violence. These findings suggest that violence prevention programs should be integrated with substance use prevention programs. [PR Health

Exergy analysis of large-scale helium liquefiers: Evaluating design trade-offs

NASA Astrophysics Data System (ADS)

Thomas, Rijo Jacob; Ghosh, Parthasarathi; Chowdhury, Kanchan

2014-01-01

It is known that higher heat exchanger area, more number of expanders with higher efficiency and more involved configuration with multi-pressure compression system increase the plant efficiency of a helium liquefier. However, they involve higher capital investment and larger size. Using simulation software Aspen Hysys v 7.0 and exergy analysis as the tool of analysis, authors have attempted to identify various trade-offs while selecting the number of stages, the pressure levels in compressor, the cold-end configuration, the heat exchanger surface area, the maximum allowable pressure drop in heat exchangers, the efficiency of expanders, the parallel/series connection of expanders etc. Use of more efficient cold ends reduces the number of refrigeration stages and the size of the plant. For achieving reliability along with performance, a configuration with a combination of expander and Joule-Thomson valve is found to be a better choice for cold end. Use of multi-pressure system is relevant only when the number of refrigeration stages is more than 5. Arrangement of expanders in series reduces the number of expanders as well as the heat exchanger size with slight expense of plant efficiency. Superior heat exchanger (having less pressure drop per unit heat transfer area) results in only 5% increase of plant performance even when it has 100% higher heat exchanger surface area.

Rigging Test Bed Development for Validation of Multi-Stage Decelerator Extractions

NASA Technical Reports Server (NTRS)

Kenig, Sivan J.; Gallon, John C.; Adams, Douglas S.; Rivellini, Tommaso P.

2013-01-01

The Low Density Supersonic Decelerator project is developing new decelerator systems for Mars entry which would include testing with a Supersonic Flight Dynamics Test Vehicle. One of the decelerator systems being developed is a large supersonic ringsail parachute. Due to the configuration of the vehicle it is not possible to deploy the parachute with a mortar which would be the preferred method for a spacecraft in a supersonic flow. Alternatively, a multi-stage extraction process using a ballute as a pilot is being developed for the test vehicle. The Rigging Test Bed is a test venue being constructed to perform verification and validation of this extraction process. The test bed consists of a long pneumatic piston device capable of providing a constant force simulating the ballute drag force during the extraction events. The extraction tests will take place both inside a high-bay for frequent tests of individual extraction stages and outdoors using a mobile hydraulic crane for complete deployment tests from initial pack pull out to canopy extraction. These tests will measure line tensions and use photogrammetry to track motion of the elements involved. The resulting data will be used to verify packing and rigging as well, as validate models and identify potential failure modes in order to finalize the design of the extraction system.

Multi-staged repair of contaminated primary and recurrent giant incisional herniae in the same hospital admission: a proposal for a new approach.

PubMed

Siddique, K; Shrestha, A; Basu, S

2014-02-01

Repair of primary and recurrent giant incisional herniae is extremely challenging and more so in the face of surgical field contamination. Literature supports the single- and multi-staged approaches including the use of biological meshes for these difficult patients with their associated benefits and limitations. This is a retrospective analysis of a prospective study of five patients who were successfully treated through a multi-staged approach but in the same hospital admission, not previously described, for the repair of contaminated primary and recurrent giant incisional herniae in a district general hospital between 2009 and 2012. Patient demographics including their BMI and ASA, previous and current operative history including complications and follow-up were collected in a secure database. The first stage involved the eradication of contamination, and the second stage was the definitive hernia repair with the new generation-coated synthetic meshes. Of the five patients, three were men and two women with a mean age of 58 (45-74) years. Two patients had grade 4 while the remaining had grade 3 hernia as per the hernia grading system with a mean BMI of 35 (30-46). All patients required extensive adhesiolysis, bowel resection and anastomoses and wash out. Hernial defect was measured as 204* (105-440) cm(2), size of mesh implant was 568* (375-930) cm(2) and the total duration of operation (1st + 2nd Stage) was 354* (270-540) min. Duration of hospital stay was 11* (7-19) days with a follow-up of 17* (6-36) months. We believe that our multi-staged approach in the same hospital admission (for the repair of contaminated primary and recurrent giant incisional herniae), excludes the disadvantages of a true multi-staged approach and simultaneously minimises the risks and complications associated with a single-staged repair, can be adopted for these challenging patients for a successful outcome (* indicates mean).

Performance improvement of multi-stage pulse tube cryocoolers with a self-precooled pulse tube

NASA Astrophysics Data System (ADS)

Qiu, L. M.; Zhi, X. Q.; Han, L.; Cao, Q.; Gan, Z. H.

2012-10-01

Reducing the pulse tube losses is significant for improving the cooling performance of pulse tube cryocoolers (PTCs) in particular for multi-stage ones, although ignored to a certain extent. A simple method called self-precooled pulse tube for multi-stage PTCs is comprehensively studied in order to reduce the entropy flow inside the pulse tube. Different from the complex multi-bypass or extra cryocooler or cryogens for precooling, the key of the idea is to directly precool some part of the lower stage pulse tube by using a small amount of cooling power from the upper stage through a thermal bridge. A two-stage separate Stirling PTC was chosen to demonstrate the effects of self-precooled pulse tube. Theoretical calculation showed that both the precooling temperature and position of the pulse tube affected the performance of the cryocooler. The experiment results showed that the cooling performance of the second stage with self-precooled pulse tube was remarkably improved as the bottom temperature decreased from 26.60 K to 18.02 K. The cooling power was notably increased with minor performance reduction of the first stage. By further optimizing the operation parameters, a no-load temperature of 15.87 K was achieved, which is the lowest temperature ever obtained by a two-stage Stirling PTC with only an inertance shifter. The study proves that the precooled pulse tube can help hot end heat exchanger reject the heat inside pulse tube, reduce the heat losses of the cold end and consequently improve the cooling performance of the cryocooler.