Reduction of EMC Emissions in Mixed Signal Integrated Circuits with Embedded LIN Driver

Directory of Open Access Journals (Sweden)

P. Hartl

2016-06-01

Full Text Available This paper describes several methods for reduction of electromagnetic emissions (EME of mixed signal integrated circuits (IC. The focus is on the impact that a LIN bus communication block has on a complex IC which contains analog blocks, noisy digital block, micro-core (µC and several types of memories. It is used in an automotive environment, where EMC emission reduction is one of the key success factors. Several proposed methods for EME reduction are described and implemented on three test chips. These methods include current consumption reduction, internal on-chip decoupling, ground separation and different linear voltage regulator topologies. Measurement results of several fabricated test chips are shown and discussed.

Dependable Digitally-Assisted Mixed-Signal IPs Based on Integrated Self-Test & Self-Calibration

NARCIS (Netherlands)

Kerkhoff, Hans G.; Wan, J.

2010-01-01

Heterogeneous SoC devices, including sensors, analogue and mixed-signal front-end circuits and the availability of massive digital processing capability, are being increasingly used in safety-critical applications like in the automotive, medical, and the security arena. Already a significant amount

Methods for Quantifying the Uncertainties of LSIT Test Parameters, Test Results, and Full-Scale Mixing Performance Using Models Developed from Scaled Test Data

International Nuclear Information System (INIS)

Piepel, Gregory F.; Cooley, Scott K.; Kuhn, William L.; Rector, David R.; Heredia-Langner, Alejandro

2015-01-01

This report discusses the statistical methods for quantifying uncertainties in 1) test responses and other parameters in the Large Scale Integrated Testing (LSIT), and 2) estimates of coefficients and predictions of mixing performance from models that relate test responses to test parameters. Testing at a larger scale has been committed to by Bechtel National, Inc. and the U.S. Department of Energy (DOE) to ''address uncertainties and increase confidence in the projected, full-scale mixing performance and operations'' in the Waste Treatment and Immobilization Plant (WTP).

Signal Based Mixing Analysis for the magnetohydrodynamic mode reconstruction from homodyne microwave reflectometry

International Nuclear Information System (INIS)

Ejiri, Akira; Sakakibara, Satoru; Kawahata, Kazuo.

1995-03-01

A new method 'Signal Based Mixing Analysis', to extract the components which are coherent to a certain reference signal from a noisy signal, has been developed. The method is applied to homodyne microwave reflectometry to reconstruct the radial structure of a magnetohydrodynamic (MHD) mode in heliotron/torsatron Compact Helical System (CHS) [K. Matsuoka et al. Plasma Phys. Control. Nuclear Fusion Research 1988 Vol. 2, IAEA, Vienna 411 (1989)]. In CHS plasmas, MHD fluctuations measured with magnetic probes show bursts, in which the amplitude and frequency quasi-periodically vary. The signal based mixing analysis uses a set of functions which have the same amplitude and the harmonic frequency as those of the magnetic fluctuations. The product (mixing) of the signal of reflectometer and the functions yields the amplitude and phase of the coherent components. When the plasma density gradually increases, the measuring position moves radially outward. Thus, the radial structure of MHD modes can be obtained by this method. The analysis indicates several peaks and nodes inside the resonance surface of the MHD mode. In addition, the structure does not propagate radially during a burst. (author)

Digital signal processing with kernel methods

CERN Document Server

Rojo-Alvarez, José Luis; Muñoz-Marí, Jordi; Camps-Valls, Gustavo

2018-01-01

A realistic and comprehensive review of joint approaches to machine learning and signal processing algorithms, with application to communications, multimedia, and biomedical engineering systems Digital Signal Processing with Kernel Methods reviews the milestones in the mixing of classical digital signal processing models and advanced kernel machines statistical learning tools. It explains the fundamental concepts from both fields of machine learning and signal processing so that readers can quickly get up to speed in order to begin developing the concepts and application software in their own research. Digital Signal Processing with Kernel Methods provides a comprehensive overview of kernel methods in signal processing, without restriction to any application field. It also offers example applications and detailed benchmarking experiments with real and synthetic datasets throughout. Readers can find further worked examples with Matlab source code on a website developed by the authors. * Presents the necess...

Test Functions for Three-Dimensional Control-Volume Mixed Finite-Element Methods on Irregular Grids

National Research Council Canada - National Science Library

Naff, R. L; Russell, T. F; Wilson, J. D

2000-01-01

.... For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error...

Property-Based Monitoring of Analog and Mixed-Signal Systems

Science.gov (United States)

Havlicek, John; Little, Scott; Maler, Oded; Nickovic, Dejan

In the recent past, there has been a steady growth of the market for consumer embedded devices such as cell phones, GPS and portable multimedia systems. In embedded systems, digital, analog and software components are combined on a single chip, resulting in increasingly complex designs that introduce richer functionality on smaller devices. As a consequence, the potential insertion of errors into a design becomes higher, yielding an increasing need for automated analog and mixed-signal validation tools. In the purely digital setting, formal verification based on properties expressed in industrial specification languages such as PSL and SVA is nowadays successfully integrated in the design flow. On the other hand, the validation of analog and mixed-signal systems still largely depends on simulation-based, ad-hoc methods. In this tutorial, we consider some ingredients of the standard verification methodology that can be successfully exported from digital to analog and mixed-signal setting, in particular property-based monitoring techniques. Property-based monitoring is a lighter approach to the formal verification, where the system is seen as a "black-box" that generates sets of traces, whose correctness is checked against a property, that is its high-level specification. Although incomplete, monitoring is effectively used to catch faults in systems, without guaranteeing their full correctness.

Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India

OpenAIRE

Sarkar, Archana; Mburu, Gitau; Shivkumar, Poonam Varma; Sharma, Pankhuri; Campbell, Fiona; Behera, Jagannath; Dargan, Ritu; Mishra, Surendra Kumar; Mehra, Sunil

2016-01-01

Introduction: HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India. Methods: A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick® HIV antibody test, and subse...

Testing the reliability and efficiency of the pilot Mixed Methods Appraisal Tool (MMAT) for systematic mixed studies review.

Science.gov (United States)

Pace, Romina; Pluye, Pierre; Bartlett, Gillian; Macaulay, Ann C; Salsberg, Jon; Jagosh, Justin; Seller, Robbyn

2012-01-01

Systematic literature reviews identify, select, appraise, and synthesize relevant literature on a particular topic. Typically, these reviews examine primary studies based on similar methods, e.g., experimental trials. In contrast, interest in a new form of review, known as mixed studies review (MSR), which includes qualitative, quantitative, and mixed methods studies, is growing. In MSRs, reviewers appraise studies that use different methods allowing them to obtain in-depth answers to complex research questions. However, appraising the quality of studies with different methods remains challenging. To facilitate systematic MSRs, a pilot Mixed Methods Appraisal Tool (MMAT) has been developed at McGill University (a checklist and a tutorial), which can be used to concurrently appraise the methodological quality of qualitative, quantitative, and mixed methods studies. The purpose of the present study is to test the reliability and efficiency of a pilot version of the MMAT. The Center for Participatory Research at McGill conducted a systematic MSR on the benefits of Participatory Research (PR). Thirty-two PR evaluation studies were appraised by two independent reviewers using the pilot MMAT. Among these, 11 (34%) involved nurses as researchers or research partners. Appraisal time was measured to assess efficiency. Inter-rater reliability was assessed by calculating a kappa statistic based on dichotomized responses for each criterion. An appraisal score was determined for each study, which allowed the calculation of an overall intra-class correlation. On average, it took 14 min to appraise a study (excluding the initial reading of articles). Agreement between reviewers was moderate to perfect with regards to MMAT criteria, and substantial with respect to the overall quality score of appraised studies. The MMAT is unique, thus the reliability of the pilot MMAT is promising, and encourages further development. Copyright © 2011 Elsevier Ltd. All rights reserved.

AnalogRF and mixed-signal circuit systematic design

CERN Document Server

Tlelo-Cuautle, Esteban; Castro-Lopez, Rafael

2013-01-01

Despite the fact that in the digital domain, designers can take full benefits of IPs and design automation tools to synthesize and design very complex systems, the analog designers’ task is still considered as a ‘handcraft’, cumbersome and very time consuming process. Thus, tremendous efforts are being deployed  to develop new design methodologies in the analog/RF and mixed-signal domains. This book collects 16 state-of-the-art contributions devoted to the topic of systematic design of analog, RF and mixed signal circuits. Divided in the two parts Methodologies and Techniques recent theories, synthesis techniques and design methodologies, as well as new sizing approaches in the field of robust analog and mixed signal design automation are presented for researchers and R/D engineers.  

A self-testing method of large analog circuits in electronic embedded systems

Energy Technology Data Exchange (ETDEWEB)

Czaja, Z, E-mail: zbczaja@pg.gda.p [Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, Department of Optoelectronics and Electronic Systems, ul. G. Narutowicza 11/12, 80-233 Gdansk (Poland)

2010-07-01

A new self-testing method of high-order filters consisting of a chain of first- or second-order filter units of mixed-signal electronic embedded systems controlled by microcontrollers or DSPs is presented in the paper. The main idea of the method bases on the fact that the signal response of the given filter unit is treated as the signal stimulation of the next filter unit. Thanks to this, a simple reconfigurable BIST consisting of only internal devices of the microcontroller controlling the system was obtained.

A self-testing method of large analog circuits in electronic embedded systems

International Nuclear Information System (INIS)

Czaja, Z

2010-01-01

A new self-testing method of high-order filters consisting of a chain of first- or second-order filter units of mixed-signal electronic embedded systems controlled by microcontrollers or DSPs is presented in the paper. The main idea of the method bases on the fact that the signal response of the given filter unit is treated as the signal stimulation of the next filter unit. Thanks to this, a simple reconfigurable BIST consisting of only internal devices of the microcontroller controlling the system was obtained.

A method for extracting chaotic signal from noisy environment

International Nuclear Information System (INIS)

Shang, L.-J.; Shyu, K.-K.

2009-01-01

In this paper, we propose a approach for extracting chaos signal from noisy environment where the chaotic signal has been contaminated by white Gaussian noise. The traditional type of independent component analysis (ICA) is capable of separating mixed signals and retrieving them independently; however, the separated signal shows unreal amplitude. The results of this study show with our method the real chaos signal can be effectively recovered.

Personnel planning in general practices: development and testing of a skill mix analysis method.

NARCIS (Netherlands)

Eitzen-Strassel, J. von; Vrijhoef, H.J.M.; Derckx, E.W.C.C.; Bakker, D.H. de

2014-01-01

Background: General practitioners (GPs) have to match patients’ demands with the mix of their practice staff’s competencies. However, apart from some general principles, there is little guidance on recruiting new staff. The purpose of this study was to develop and test a method which would allow GPs

Personnel planning in general practices : Development and testing of a skill mix analysis method

NARCIS (Netherlands)

von Eitzen-Strassel, J.; Vrijhoef, H.J.M.; Derckx, E.W.C.C.; de Bakker, D.H.

2014-01-01

Background General practitioners (GPs) have to match patients’ demands with the mix of their practice staff’s competencies. However, apart from some general principles, there is little guidance on recruiting new staff. The purpose of this study was to develop and test a method which would allow GPs

[Application of the mixed programming with Labview and Matlab in biomedical signal analysis].

Science.gov (United States)

Yu, Lu; Zhang, Yongde; Sha, Xianzheng

2011-01-01

This paper introduces the method of mixed programming with Labview and Matlab, and applies this method in a pulse wave pre-processing and feature detecting system. The method has been proved suitable, efficient and accurate, which has provided a new kind of approach for biomedical signal analysis.

The Value of Mixed Methods Research: A Mixed Methods Study

Science.gov (United States)

McKim, Courtney A.

2017-01-01

The purpose of this explanatory mixed methods study was to examine the perceived value of mixed methods research for graduate students. The quantitative phase was an experiment examining the effect of a passage's methodology on students' perceived value. Results indicated students scored the mixed methods passage as more valuable than those who…

Testing effects in mixed- versus pure-list designs.

Science.gov (United States)

Rowland, Christopher A; Littrell-Baez, Megan K; Sensenig, Amanda E; DeLosh, Edward L

2014-08-01

In the present study, we investigated the role of list composition in the testing effect. Across three experiments, participants learned items through study and initial testing or study and restudy. List composition was manipulated, such that tested and restudied items appeared either intermixed in the same lists (mixed lists) or in separate lists (pure lists). In Experiment 1, half of the participants received mixed lists and half received pure lists. In Experiment 2, all participants were given both mixed and pure lists. Experiment 3 followed Erlebacher's (Psychological Bulletin, 84, 212-219, 1977) method, such that mixed lists, pure tested lists, and pure restudied lists were given to independent groups. Across all three experiments, the final recall results revealed significant testing effects for both mixed and pure lists, with no reliable difference in the magnitude of the testing advantage across list designs. This finding suggests that the testing effect is not subject to a key boundary condition-list design-that impacts other memory phenomena, including the generation effect.

Applied Chaos Level Test for Validation of Signal Conditions Underlying Optimal Performance of Voice Classification Methods

Science.gov (United States)

Liu, Boquan; Polce, Evan; Sprott, Julien C.; Jiang, Jack J.

2018-01-01

Purpose: The purpose of this study is to introduce a chaos level test to evaluate linear and nonlinear voice type classification method performances under varying signal chaos conditions without subjective impression. Study Design: Voice signals were constructed with differing degrees of noise to model signal chaos. Within each noise power, 100…

A preliminary mixed-method investigation of trust and hidden signals in medical consultations.

Directory of Open Access Journals (Sweden)

Silvia Riva

Full Text Available Several factors influence patients' trust, and trust influences the doctor-patient relationship. Recent literature has investigated the quality of the personal relationship and its dynamics by considering the role of communication and the elements that influence trust giving in the frame of general practitioner (GP consultations.We analysed certain aspects of the interaction between patients and GPs to understand trust formation and maintenance by focusing on communication channels. The impact of socio-demographic variables in trust relationships was also evaluated.A cross-sectional design using concurrent mixed qualitative and quantitative research methods was employed. One hundred adults were involved in a semi-structured interview composed of both qualitative and quantitative items for descriptive and exploratory purposes. The study was conducted in six community-based departments adjacent to primary care clinics in Trento, Italy.The findings revealed that patients trusted their GP to a high extent by relying on simple signals that were based on the quality of the one-to-one communication and on behavioural and relational patterns. Patients inferred the ability of their GP by adopting simple heuristics based mainly on the so-called social "honest signals" rather than on content-dependent features. Furthermore, socio-demographic variables affected trust: less literate and elderly people tended to trust more.This study is unique in attempting to explore the role of simple signals in trust relationships within medical consultation: people shape trust and give meaning to their relationships through a powerful channel of communication that orbits not around words but around social relations. The findings have implications for both clinicians and researchers. For doctors, these results suggest a way of thinking about encounters with patients. For researchers, the findings underline the importance of analysing some new key factors around trust for

African and Caribbean Nurses' Decisions about HIV Testing: A Mixed Methods Study.

Science.gov (United States)

Harrowing, Jean N; Edwards, Nancy; Richter, Solina; Minnie, Karin; Rae, Tania

2018-02-01

Nurses in Jamaica, Kenya, South Africa, and Uganda are at risk for occupational exposure to HIV. Little is known about the experiences and policy supports related to nurses having themselves tested for the virus. This article reports a mixed-methods study about contextual influences on nurses' decision-making about HIV testing. Individual and focus group interviews, as well as a questionnaire on workplace polices and quality assurance and a human resource management assessment tool provided data. Fear of a positive diagnosis and stigma and lack of confidentiality along with gaps in the policy environment contributed to indecision about testing. There were significant differences in policy supports among countries. Institutional support must be addressed if improvements in HIV testing for health care workers are going to be effectively implemented. Future work is required to better understand how HRM policies intersect to create conditions of perceived vulnerability for HIV positive staff.

Addressing Research Design Problem in Mixed Methods Research

Science.gov (United States)

Alavi, Hamed; Hąbek, Patrycja

2016-03-01

Alongside other disciplines in social sciences, management researchers use mixed methods research more and more in conduct of their scientific investigations. Mixed methods approach can also be used in the field of production engineering. In comparison with traditional quantitative and qualitative research methods, reasons behind increasing popularity of mixed research method in management science can be traced in different factors. First of all, any particular discipline in management can be theoretically related to it. Second is that concurrent approach of mixed research method to inductive and deductive research logic provides researchers with opportunity to generate theory and test hypothesis in one study simultaneously. In addition, it provides a better justification for chosen method of investigation and higher validity for obtained answers to research questions. Despite increasing popularity of mixed research methods among management scholars, there is still need for a comprehensive approach to research design typology and process in mixed research method from the perspective of management science. The authors in this paper try to explain fundamental principles of mixed research method, its typology and different steps in its design process.

Research on Weak Fault Extraction Method for Alleviating the Mode Mixing of LMD

Directory of Open Access Journals (Sweden)

Lin Zhang

2018-05-01

Full Text Available Compared with the strong background noise, the energy entropy of early fault signals of bearings are weak under actual working conditions. Therefore, extracting the bearings’ early fault features has always been a major difficulty in fault diagnosis of rotating machinery. Based on the above problems, the masking method is introduced into the Local Mean Decomposition (LMD decomposition process, and a weak fault extraction method based on LMD and mask signal (MS is proposed. Due to the mode mixing of the product function (PF components decomposed by LMD in the noisy background, it is difficult to distinguish the authenticity of the fault frequency. Therefore, the MS method is introduced to deal with the PF components that are decomposed by the LMD and have strong correlation with the original signal, so as to suppress the modal aliasing phenomenon and extract the fault frequencies. In this paper, the actual fault signal of the rolling bearing is analyzed. By combining the MS method with the LMD method, the fault signal mixed with the noise is processed. The kurtosis value at the fault frequency is increased by eight-fold, and the signal-to-noise ratio (SNR is increased by 19.1%. The fault signal is successfully extracted by the proposed composite method.

Optimal Signal Design for Mixed Equilibrium Networks with Autonomous and Regular Vehicles

Directory of Open Access Journals (Sweden)

Nan Jiang

2017-01-01

Full Text Available A signal design problem is studied for efficiently managing autonomous vehicles (AVs and regular vehicles (RVs simultaneously in transportation networks. AVs and RVs move on separate lanes and two types of vehicles share the green times at the same intersections. The signal design problem is formulated as a bilevel program. The lower-level model describes a mixed equilibrium where autonomous vehicles follow the Cournot-Nash (CN principle and RVs follow the user equilibrium (UE principle. In the upper-level model, signal timings are optimized at signalized intersections to allocate appropriate green times to both autonomous and RVs to minimize system travel cost. The sensitivity analysis based method is used to solve the bilevel optimization model. Various signal control strategies are evaluated through numerical examples and some insightful findings are obtained. It was found that the number of phases at intersections should be reduced for the optimal control of the AVs and RVs in the mixed networks. More importantly, incorporating AVs into the transportation network would improve the system performance due to the value of AV technologies in reducing random delays at intersections. Meanwhile, travelers prefer to choose AVs when the networks turn to be congested.

A Mixed-Signal Embedded Platform for Automotive Sensor Conditioning

OpenAIRE

Emilio Volpi; Luca Fanucci; Adolfo Giambastiani; Alessandro Rocchi; Francesco D'Ascoli; Marco Tonarelli; Massimiliano Melani; Corrado Marino

2010-01-01

Abstract A mixed-signal embedded system called Intelligent Sensor InterFace (ISIF) suited to fast identify, trim, and verify an architecture to interface a given sensor is presented. This system has been developed according to a platform-based design approach, a methodology that has proved to be efficient for building complex mixed-signal embedded systems with short time-to-market. Such platform consists in a wide set of optimized high-performance analog, digital, and software intellectual pr...

Mixed methods research.

Science.gov (United States)

Halcomb, Elizabeth; Hickman, Louise

2015-04-08

Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

Standard test methods for determining chemical durability of nuclear, hazardous, and mixed waste glasses and multiphase glass ceramics: The product consistency test (PCT)

CERN Document Server

American Society for Testing and Materials. Philadelphia

2002-01-01

1.1 These product consistency test methods A and B evaluate the chemical durability of homogeneous glasses, phase separated glasses, devitrified glasses, glass ceramics, and/or multiphase glass ceramic waste forms hereafter collectively referred to as “glass waste forms” by measuring the concentrations of the chemical species released to a test solution. 1.1.1 Test Method A is a seven-day chemical durability test performed at 90 ± 2°C in a leachant of ASTM-Type I water. The test method is static and conducted in stainless steel vessels. Test Method A can specifically be used to evaluate whether the chemical durability and elemental release characteristics of nuclear, hazardous, and mixed glass waste forms have been consistently controlled during production. This test method is applicable to radioactive and simulated glass waste forms as defined above. 1.1.2 Test Method B is a durability test that allows testing at various test durations, test temperatures, mesh size, mass of sample, leachant volume, a...

Development of thermal mixing enhancement method for lower plenum of the High Temperature Test Facility

Energy Technology Data Exchange (ETDEWEB)

Gradecka, Malwina Joanna, E-mail: malgrad@gmail.com; Woods, Brian G., E-mail: brian.woods@oregonstate.edu

2016-08-15

Highlights: • Coolant mixing in lower plenum might be insufficient and pose operational issues. • Two mixing methods were developed to lower the coolant temperature variation. • The methods resulted with reduction of the temperature variation by 60% and 71%. - Abstract: The High Temperature Gas-cooled Reactor (HTGR) is one of the most mature Gen IV reactor concepts under development today. The High Temperature Test Facility (HTTF) at Oregon State University is a test facility that supports the R&D needs for HTGRs. This study focuses on the issue of helium mixing after the core section in the HTTF, the results of which are generally applicable in HTGRs. In the HTTF, hot helium jets at different temperatures are supposed to uniformly mix in the lower plenum (LP) chamber. However, the level of mixing is not sufficient to reduce the peak helium temperature before the hot jet impinges the LP structure, which can cause issues with structural materials and operational issues in the heat exchanger downstream. The maximum allowable temperature variation in the outlet duct connected to the lower plenum is defined as 40 K (±20 K from the average temperature), while the CFD simulations of this study indicate that the reference design suffers temperature variations in the duct as high as 100 K. To solve this issue, the installation of mixing-enhancing structures within the outlet duct were proposed and analyzed using CFD modeling. We show that using either an optimized “Kwiat” structure (developed in this study) or a motionless mixer installed in the outlet duct, the temperature variations can be brought dramatically, with acceptable increases in pressure drop. The optimal solution appears to be to install double motionless mixers with long blades in the outlet duct, which brings the temperature variation into the acceptable range (from 100 K down to 18 K), with a resulting pressure drop increase in the HTTF loop of 0.73 kPa (6% of total pressure drop).

Development of thermal mixing enhancement method for lower plenum of the High Temperature Test Facility

International Nuclear Information System (INIS)

Gradecka, Malwina Joanna; Woods, Brian G.

2016-01-01

Highlights: • Coolant mixing in lower plenum might be insufficient and pose operational issues. • Two mixing methods were developed to lower the coolant temperature variation. • The methods resulted with reduction of the temperature variation by 60% and 71%. - Abstract: The High Temperature Gas-cooled Reactor (HTGR) is one of the most mature Gen IV reactor concepts under development today. The High Temperature Test Facility (HTTF) at Oregon State University is a test facility that supports the R&D needs for HTGRs. This study focuses on the issue of helium mixing after the core section in the HTTF, the results of which are generally applicable in HTGRs. In the HTTF, hot helium jets at different temperatures are supposed to uniformly mix in the lower plenum (LP) chamber. However, the level of mixing is not sufficient to reduce the peak helium temperature before the hot jet impinges the LP structure, which can cause issues with structural materials and operational issues in the heat exchanger downstream. The maximum allowable temperature variation in the outlet duct connected to the lower plenum is defined as 40 K (±20 K from the average temperature), while the CFD simulations of this study indicate that the reference design suffers temperature variations in the duct as high as 100 K. To solve this issue, the installation of mixing-enhancing structures within the outlet duct were proposed and analyzed using CFD modeling. We show that using either an optimized “Kwiat” structure (developed in this study) or a motionless mixer installed in the outlet duct, the temperature variations can be brought dramatically, with acceptable increases in pressure drop. The optimal solution appears to be to install double motionless mixers with long blades in the outlet duct, which brings the temperature variation into the acceptable range (from 100 K down to 18 K), with a resulting pressure drop increase in the HTTF loop of 0.73 kPa (6% of total pressure drop).

Test signal generation for analog circuits

Directory of Open Access Journals (Sweden)

B. Burdiek

2003-01-01

Full Text Available In this paper a new test signal generation approach for general analog circuits based on the variational calculus and modern control theory methods is presented. The computed transient test signals also called test stimuli are optimal with respect to the detection of a given fault set by means of a predefined merit functional representing a fault detection criterion. The test signal generation problem of finding optimal test stimuli detecting all faults form the fault set is formulated as an optimal control problem. The solution of the optimal control problem representing the test stimuli is computed using an optimization procedure. The optimization procedure is based on the necessary conditions for optimality like the maximum principle of Pontryagin and adjoint circuit equations.

A mixed signal ECG processing platform with an adaptive sampling ADC for portable monitoring applications.

Science.gov (United States)

Kim, Hyejung; Van Hoof, Chris; Yazicioglu, Refet Firat

2011-01-01

This paper describes a mixed-signal ECG processing platform with an 12-bit ADC architecture that can adapt its sampling rate according to the input signals rate of change. This enables the sampling of ECG signals with significantly reduced data rate without loss of information. The presented adaptive sampling scheme reduces the ADC power consumption, enables the processing of ECG signals with lower power consumption, and reduces the power consumption of the radio while streaming the ECG signals. The test results show that running a CWT-based R peak detection algorithm using the adaptively sampled ECG signals consumes only 45.6 μW and it leads to 36% less overall system power consumption.

Simplified methods to assess thermal fatigue due to turbulent mixing

International Nuclear Information System (INIS)

Hannink, M.H.C.; Timperi, A.

2011-01-01

Thermal fatigue is a safety relevant damage mechanism in pipework of nuclear power plants. A well-known simplified method for the assessment of thermal fatigue due to turbulent mixing is the so-called sinusoidal method. Temperature fluctuations in the fluid are described by a sinusoidally varying signal at the inner wall of the pipe. Because of limited information on the thermal loading conditions, this approach generally leads to overconservative results. In this paper, a new assessment method is presented, which has the potential of reducing the overconservatism of existing procedures. Artificial fluid temperature signals are generated by superposition of harmonic components with different amplitudes and frequencies. The amplitude-frequency spectrum of the components is modelled by a formula obtained from turbulence theory, whereas the phase differences are assumed to be randomly distributed. Lifetime predictions generated with the new simplified method are compared with lifetime predictions based on real fluid temperature signals, measured in an experimental setup of a mixing tee. Also, preliminary steady-state Computational Fluid Dynamics (CFD) calculations of the total power of the fluctuations are presented. The total power is needed as an input parameter for the spectrum formula in a real-life application. Solution of the transport equation for the total power was included in a CFD code and comparisons with experiments were made. The newly developed simplified method for generating the temperature signal is shown to be adequate for the investigated geometry and flow conditions, and demonstrates possibilities of reducing the conservatism of the sinusoidal method. CFD calculations of the total power show promising results, but further work is needed to develop the approach. (author)

Updating and testing of a Finnish method for mixed municipal solid waste composition studies.

Science.gov (United States)

Liikanen, M; Sahimaa, O; Hupponen, M; Havukainen, J; Sorvari, J; Horttanainen, M

2016-06-01

More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of Design of Mixed-Signal Electronic Packaging

National Research Council Canada - National Science Library

Pileggi, Lawrence

1999-01-01

The objective of this project is to develop innovative algorithms and prototype tools that will help facilitate the design of mixed signal multi-chip modules and packaging in a manner that is similar...

Panel-basierte Mixed-Methods-Studien

OpenAIRE

Legewie, Nicolas; Tucci, Ingrid

2016-01-01

Mixed-Methods-Studien erfreuen sich wachsender Beliebtheit. Immer mehr Studien nutzen dabei auch Panel-basierte Mixed-Methods-Designs, in denen bestehende Längsschnittstudien durch qualitative Befragungsformen ergänzt werden. Innerhalb der reichhaltigen Veröffentlichungen zum Thema Mixed-Methods-Forschung finden sich bisher aber kaum Diskussionen solcher Mixed-Methods-Designs. Im vorliegenden Artikel diskutieren wir Design, Durchführung, sowie Potenzialeund Herausforderungen von Panel-basiert...

Gradient method for blind chaotic signal separation based on proliferation exponent

International Nuclear Information System (INIS)

Lü Shan-Xiang; Wang Zhao-Shan; Hu Zhi-Hui; Feng Jiu-Chao

2014-01-01

A new method to perform blind separation of chaotic signals is articulated in this paper, which takes advantage of the underlying features in the phase space for identifying various chaotic sources. Without incorporating any prior information about the source equations, the proposed algorithm can not only separate the mixed signals in just a few iterations, but also outperforms the fast independent component analysis (FastICA) method when noise contamination is considerable. (general)

lmerTest Package: Tests in Linear Mixed Effects Models

DEFF Research Database (Denmark)

Kuznetsova, Alexandra; Brockhoff, Per B.; Christensen, Rune Haubo Bojesen

2017-01-01

One of the frequent questions by users of the mixed model function lmer of the lme4 package has been: How can I get p values for the F and t tests for objects returned by lmer? The lmerTest package extends the 'lmerMod' class of the lme4 package, by overloading the anova and summary functions...... by providing p values for tests for fixed effects. We have implemented the Satterthwaite's method for approximating degrees of freedom for the t and F tests. We have also implemented the construction of Type I - III ANOVA tables. Furthermore, one may also obtain the summary as well as the anova table using...

10 CFR 431.224 - Uniform test method for the measurement of energy consumption for traffic signal modules and...

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Uniform test method for the measurement of energy consumption for traffic signal modules and pedestrian modules. 431.224 Section 431.224 Energy DEPARTMENT OF... measurement of energy consumption for traffic signal modules and pedestrian modules. (a) Scope. This section...

Comparison of two different high performance mixed signal controllers for DC/DC converters

DEFF Research Database (Denmark)

Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

2006-01-01

This paper describes how mixed signal controllers combining a cheap microcontroller with a simple analogue circuit can offer high performance digital control for DC/DC converters. Mixed signal controllers have the same versatility and performance as DSP based controllers. It is important to have...... an engineer experienced in microcontroller programming write the software algorithms to achieve optimal performance. Two mixed signal controller designs based on the same 8-bit microcontroller are compared both theoretically and experimentally. A 16-bit PID compensator with a sampling frequency of 200 k......Hz implemented in the 16 MIPS, 8-bit ATTiny26 microcontroller is demonstrated....

Test Pattern Generator for Mixed Mode BIST

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Sik; Lee, Hang Kyu; Kang, Sung Ho [Yonsei University (Korea, Republic of)

1998-07-01

As the increasing integrity of VLSI, the BIST (Built-In Self Test) is used as an effective method to test chips. Generally the pseudo-random test pattern generation is used for BIST. But it requires lots of test patterns when there exist random resistant faults. Therefore deterministic testing is an interesting BIST technique due to the minimal number of test patterns and to its high fault coverage. However this is not applicable since the existing deterministic test pattern generators require too much area overhead despite their efficiency. Therefore we propose a mixed test scheme which applies to the circuit under test, a deterministic test sequence followed by a pseudo-random one. This scheme allows the maximum fault coverage detection to be achieved, furthermore the silicon area overhead of the mixed hardware generator can be reduced. The deterministic test generator is made with a finite state machine and a pseudo-random test generator is made with LFSR(linear feedback shift register). The results of ISCAS circuits show that the maximum fault coverage is guaranteed with small number of test set and little hardware overhead. (author). 15 refs., 10 figs., 4 tabs.

A New Built-in Self Test Scheme for Phase-Locked Loops Using Internal Digital Signals

Science.gov (United States)

Kim, Youbean; Kim, Kicheol; Kim, Incheol; Kang, Sungho

Testing PLLs (phase-locked loops) is becoming an important issue that affects both time-to-market and production cost of electronic systems. Though a PLL is the most common mixed-signal building block, it is very difficult to test due to internal analog blocks and signals. In this paper, we propose a new PLL BIST (built-in self test) using the distorted frequency detector that uses only internal digital signals. The proposed BIST does not need to load any analog nodes of the PLL. Therefore, it provides an efficient defect-oriented structural test scheme, reduced area overhead, and improved test quality compared with previous approaches.

Sensing Methods for Detecting Analog Television Signals

Science.gov (United States)

Rahman, Mohammad Azizur; Song, Chunyi; Harada, Hiroshi

This paper introduces a unified method of spectrum sensing for all existing analog television (TV) signals including NTSC, PAL and SECAM. We propose a correlation based method (CBM) with a single reference signal for sensing any analog TV signals. In addition we also propose an improved energy detection method. The CBM approach has been implemented in a hardware prototype specially designed for participating in Singapore TV white space (WS) test trial conducted by Infocomm Development Authority (IDA) of the Singapore government. Analytical and simulation results of the CBM method will be presented in the paper, as well as hardware testing results for sensing various analog TV signals. Both AWGN and fading channels will be considered. It is shown that the theoretical results closely match with those from simulations. Sensing performance of the hardware prototype will also be presented in fading environment by using a fading simulator. We present performance of the proposed techniques in terms of probability of false alarm, probability of detection, sensing time etc. We also present a comparative study of the various techniques.

Estimation of the common cause failure probabilities on the component group with mixed testing scheme

International Nuclear Information System (INIS)

Hwang, Meejeong; Kang, Dae Il

2011-01-01

Highlights: ► This paper presents a method to estimate the common cause failure probabilities on the common cause component group with mixed testing schemes. ► The CCF probabilities are dependent on the testing schemes such as staggered testing or non-staggered testing. ► There are many CCCGs with specific mixed testing schemes in real plant operation. ► Therefore, a general formula which is applicable to both alternate periodic testing scheme and train level mixed testing scheme was derived. - Abstract: This paper presents a method to estimate the common cause failure (CCF) probabilities on the common cause component group (CCCG) with mixed testing schemes such as the train level mixed testing scheme or the alternate periodic testing scheme. In the train level mixed testing scheme, the components are tested in a non-staggered way within the same train, but the components are tested in a staggered way between the trains. The alternate periodic testing scheme indicates that all components in the same CCCG are tested in a non-staggered way during the planned maintenance period, but they are tested in a staggered way during normal plant operation. Since the CCF probabilities are dependent on the testing schemes such as staggered testing or non-staggered testing, CCF estimators have two kinds of formulas in accordance with the testing schemes. Thus, there are general formulas to estimate the CCF probability on the staggered testing scheme and non-staggered testing scheme. However, in real plant operation, there are many CCCGs with specific mixed testing schemes. Recently, Barros () and Kang () proposed a CCF factor estimation method to reflect the alternate periodic testing scheme and the train level mixed testing scheme. In this paper, a general formula which is applicable to both the alternate periodic testing scheme and the train level mixed testing scheme was derived.

Quantification, modelling and design for signal history dependent effects in mixed-signal SOI/SOS circuits

International Nuclear Information System (INIS)

Edwards, C.F.; Redman-White, W.; Bracey, M.; Tenbroek, B.M.; Lee, M.S.; Uren, M.J.; Brunson, K.M.

1999-01-01

This paper deals with how the radiation hardness of mixed signal SOI/SOS CMOS circuits is taken into account at both architectural terms as well as the the transistor level cell designs. The primary issue is to deal with divergent transistor threshold shifts, and to understand the effects of large amplitude non stationary signals on analogue cell behaviour. (authors)

Mixed Methods Research in School Psychology: A Mixed Methods Investigation of Trends in the Literature

Science.gov (United States)

Powell, Heather; Mihalas, Stephanie; Onwuegbuzie, Anthony J.; Suldo, Shannon; Daley, Christine E.

2008-01-01

This article illustrates the utility of mixed methods research (i.e., combining quantitative and qualitative techniques) to the field of school psychology. First, the use of mixed methods approaches in school psychology practice is discussed. Second, the mixed methods research process is described in terms of school psychology research. Third, the…

A Perceptually Reweighted Mixed-Norm Method for Sparse Approximation of Audio Signals

DEFF Research Database (Denmark)

Christensen, Mads Græsbøll; Sturm, Bob L.

2011-01-01

using standard software. A prominent feature of the new method is that it solves a problem that is closely related to the objective of coding, namely rate-distortion optimization. In computer simulations, we demonstrate the properties of the algorithm and its application to real audio signals.......In this paper, we consider the problem of finding sparse representations of audio signals for coding purposes. In doing so, it is of utmost importance that when only a subset of the present components of an audio signal are extracted, it is the perceptually most important ones. To this end, we...... propose a new iterative algorithm based on two principles: 1) a reweighted l1-norm based measure of sparsity; and 2) a reweighted l2-norm based measure of perceptual distortion. Using these measures, the considered problem is posed as a constrained convex optimization problem that can be solved optimally...

Medical Image Denoising Using Mixed Transforms

Directory of Open Access Journals (Sweden)

Jaleel Sadoon Jameel

2018-02-01

Full Text Available  In this paper,  a mixed transform method is proposed based on a combination of wavelet transform (WT and multiwavelet transform (MWT in order to denoise medical images. The proposed method consists of WT and MWT in cascade form to enhance the denoising performance of image processing. Practically, the first step is to add a noise to Magnetic Resonance Image (MRI or Computed Tomography (CT images for the sake of testing. The noisy image is processed by WT to achieve four sub-bands and each sub-band is treated individually using MWT before the soft/hard denoising stage. Simulation results show that a high peak signal to noise ratio (PSNR is improved significantly and the characteristic features are well preserved by employing mixed transform of WT and MWT due to their capability of separating noise signals from image signals. Moreover, the corresponding mean square error (MSE is decreased accordingly compared to other available methods.

Goodness-of-fit tests in mixed models

KAUST Repository

Claeskens, Gerda

2009-05-12

Mixed models, with both random and fixed effects, are most often estimated on the assumption that the random effects are normally distributed. In this paper we propose several formal tests of the hypothesis that the random effects and/or errors are normally distributed. Most of the proposed methods can be extended to generalized linear models where tests for non-normal distributions are of interest. Our tests are nonparametric in the sense that they are designed to detect virtually any alternative to normality. In case of rejection of the null hypothesis, the nonparametric estimation method that is used to construct a test provides an estimator of the alternative distribution. © 2009 Sociedad de Estadística e Investigación Operativa.

Eddy currents non-destructive testing. use of a numeric/symbolic method to separate and characterize the transitions of a signal

International Nuclear Information System (INIS)

Benas, J.C.; Lefevre, F.; Gaillard, P.; Georgel, B.

1995-01-01

This paper presents an original numeric/symbolic method for solving an inverse problem in the field of non-destructive testing. The purpose of this method is to characterize the transitions of a signal even when they are superimposed. Its principle is to solve as many direct problems as necessary to obtain the solution, and to use some hypothesis to manage the reasoning of the process. The direct problem calculation yields to a 'model signal', and the solution is reached when the model signal is close to the measured one. This method calculates the directions of minimization thanks to a symbolic reasoning based on the peaks of the residual signal. The results of the method are good and seem very promising. (authors). 13 refs., 13 figs., 5 tabs

10 best resources on ... mixed methods research in health systems.

Science.gov (United States)

Ozawa, Sachiko; Pongpirul, Krit

2014-05-01

Mixed methods research has become increasingly popular in health systems. Qualitative approaches are often used to explain quantitative results and help to develop interventions or survey instruments. Mixed methods research is especially important in low- and middle-income country (LMIC) settings, where understanding social, economic and cultural contexts are essential to assess health systems performance. To provide researchers and programme managers with a guide to mixed methods research in health systems, we review the best resources with a focus on LMICs. We selected 10 best resources (eight peer-reviewed articles and two textbooks) based on their importance and frequency of use (number of citations), comprehensiveness of content, usefulness to readers and relevance to health systems research in resource-limited contexts. We start with an overview on mixed methods research and discuss resources that are useful for a better understanding of the design and conduct of mixed methods research. To illustrate its practical applications, we provide examples from various countries (China, Vietnam, Kenya, Tanzania, Zambia and India) across different health topics (tuberculosis, malaria, HIV testing and healthcare costs). We conclude with some toolkits which suggest what to do when mixed methods findings conflict and provide guidelines for evaluating the quality of mixed methods research.

Identification of DNA-Binding Proteins Using Mixed Feature Representation Methods.

Science.gov (United States)

Qu, Kaiyang; Han, Ke; Wu, Song; Wang, Guohua; Wei, Leyi

2017-09-22

DNA-binding proteins play vital roles in cellular processes, such as DNA packaging, replication, transcription, regulation, and other DNA-associated activities. The current main prediction method is based on machine learning, and its accuracy mainly depends on the features extraction method. Therefore, using an efficient feature representation method is important to enhance the classification accuracy. However, existing feature representation methods cannot efficiently distinguish DNA-binding proteins from non-DNA-binding proteins. In this paper, a multi-feature representation method, which combines three feature representation methods, namely, K-Skip-N-Grams, Information theory, and Sequential and structural features (SSF), is used to represent the protein sequences and improve feature representation ability. In addition, the classifier is a support vector machine. The mixed-feature representation method is evaluated using 10-fold cross-validation and a test set. Feature vectors, which are obtained from a combination of three feature extractions, show the best performance in 10-fold cross-validation both under non-dimensional reduction and dimensional reduction by max-relevance-max-distance. Moreover, the reduced mixed feature method performs better than the non-reduced mixed feature technique. The feature vectors, which are a combination of SSF and K-Skip-N-Grams, show the best performance in the test set. Among these methods, mixed features exhibit superiority over the single features.

Identification of DNA-Binding Proteins Using Mixed Feature Representation Methods

Directory of Open Access Journals (Sweden)

Kaiyang Qu

2017-09-01

Full Text Available DNA-binding proteins play vital roles in cellular processes, such as DNA packaging, replication, transcription, regulation, and other DNA-associated activities. The current main prediction method is based on machine learning, and its accuracy mainly depends on the features extraction method. Therefore, using an efficient feature representation method is important to enhance the classification accuracy. However, existing feature representation methods cannot efficiently distinguish DNA-binding proteins from non-DNA-binding proteins. In this paper, a multi-feature representation method, which combines three feature representation methods, namely, K-Skip-N-Grams, Information theory, and Sequential and structural features (SSF, is used to represent the protein sequences and improve feature representation ability. In addition, the classifier is a support vector machine. The mixed-feature representation method is evaluated using 10-fold cross-validation and a test set. Feature vectors, which are obtained from a combination of three feature extractions, show the best performance in 10-fold cross-validation both under non-dimensional reduction and dimensional reduction by max-relevance-max-distance. Moreover, the reduced mixed feature method performs better than the non-reduced mixed feature technique. The feature vectors, which are a combination of SSF and K-Skip-N-Grams, show the best performance in the test set. Among these methods, mixed features exhibit superiority over the single features.

Advantages of the non-stationary approach: test on eddy current signals

International Nuclear Information System (INIS)

Brunel, P.

1993-12-01

Conventional signal processing is often unsuitable for the interpretation of intrinsically non-stationary signals, such as surveillance or non destructive testing signals. In these cases, ''advanced'' methods are required. This report presents two applications of non-stationary signal processing methods to the complex signals obtained in eddy current non destructive testing of steam generator tubes. The first application consists in segmenting the absolute channel, which can be likened to a piecewise constant signal. The Page-Hinkley cumulative sum algorithm is used, enabling detection of unknown mean amplitude jumps in a piecewise constant signal disturbed by a white noise. Results are comparable to those obtained with the empirical method currently in use. As easy to implement as the latter, the Page-Hinkley algorithm has the added advantage of being well formalized and of identifying whether the jumps in mean are positive or negative. The second application concerns assistance in detecting characteristic fault transients in the differential channels, using the continuous wavelet transform. The useful signal and noise spectra are fairly close, but not strictly identical. With the continuous wavelet transform, these frequency differences can be turned to account. The method was tested on synthetic signals obtained by summing noise and real defect signals. Using the continuous wavelet transform reduces the minimum signal-to-noise ratio by 5 dB for detection of a transient as compared with direct detection on the original signal. Finally, a summary of non-stationary methods using our data is presented. The two investigations described confirm that non-stationary methods may be considered as interesting signal and image analysis tools, as an efficient complement to conventional methods. (author). 24 figs., 13 refs

Mixed methods for telehealth research.

Science.gov (United States)

Caffery, Liam J; Martin-Khan, Melinda; Wade, Victoria

2017-10-01

Mixed methods research is important to health services research because the integrated qualitative and quantitative investigation can give a more comprehensive understanding of complex interventions such as telehealth than can a single-method study. Further, mixed methods research is applicable to translational research and program evaluation. Study designs relevant to telehealth research are described and supported by examples. Quality assessment tools, frameworks to assist in the reporting and review of mixed methods research, and related methodologies are also discussed.

Mixed-Methods Research Methodologies

Science.gov (United States)

Terrell, Steven R.

2012-01-01

Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

Stochastic resonance in a time-delayed asymmetric bistable system with mixed periodic signal

International Nuclear Information System (INIS)

Yong-Feng, Guo; Wei, Xu; Liang, Wang

2010-01-01

This paper studies the phenomenon of stochastic resonance in an asymmetric bistable system with time-delayed feedback and mixed periodic signal by using the theory of signal-to-noise ratio in the adiabatic limit. A general approximate Fokker–Planck equation and the expression of the signal-to-noise ratio are derived through the small time delay approximation at both fundamental harmonics and mixed harmonics. The effects of the additive noise intensity Q, multiplicative noise intensity D, static asymmetry r and delay time τ on the signal-to-noise ratio are discussed. It is found that the higher mixed harmonics and the static asymmetry r can restrain stochastic resonance, and the delay time τ can enhance stochastic resonance. Moreover, the longer the delay time τ is, the larger the additive noise intensity Q and the multiplicative noise intensity D are, when the stochastic resonance appears. (general)

13C mixed triglyceride breath test: a noninvasive method to assess lipase activity in children.

Science.gov (United States)

van Dijk-van Aalst, K; Van Den Driessche, M; van Der Schoor, S; Schiffelers, S; van't Westeinde, T; Ghoos, Y; Veereman-Wauters, G

2001-05-01

Results from the 13C mixed triglyceride (MTG) breath test correlate with duodenal lipase activity in adults. This noninvasive test is a potential screening and diagnostic tool for children with fat malabsorption. The aim of this study was to adapt the methodology of the MTG breath test to study test meals and sampling methods and to define normal values for healthy children of all age groups; premature and full-term infants have similar pancreatic lipase deficiencies. After parental consent was obtained, 12 premature infants ( 2 kg), 12 full-term infants (1-6 months old), 20 children (3-10 years old), and 20 teenagers (11-17 years old) were tested. All children were thriving well, had no gastrointestinal or respiratory problems, and had not received any medication that contained natural 13C. For the premature and full-term infants, a formula was prepared that had a low and stable natural 13C content mixed with 100 mg 13C-labeled MTG (1,3-distearyl, 2-[13C-carboxyl] octanoyl glycerol) and 1 g polyethylene-glycol 3350. The best accepted test meal for children over 3 years old was a slice of white bread with 5 g butter and 15 g chocolate paste, mixed with 250 mg 13C-labeled MTG, and a glass of 100 mL whole-fat milk. Children over 3 years old were able to blow through a straw in a vacutainer for collecting the breath samples. In children under 3 years old, expired air was collected by aspirating breath via a nasal prong. Carbon dioxide production was calculated according to weight, age, and sex. For healthy pediatric control participants, the mean values for cumulative excretion of 13CO2 as a percentage of the administered dose after 6 hours were 23.9 +/- 5.2% in premature infants, 31.9 +/- 7.7% in full-term infants, 32.5 +/- 5.3% in children, and 28.0 +/- 5.4% in teenagers. The mean value for healthy adults is 35.6% with a lower reference limit of 22.8%. Age-specific test meals and breath-sampling techniques for the MTG breath test were defined. The mean values for

A Mixed-Signal Embedded Platform for Automotive Sensor Conditioning

Directory of Open Access Journals (Sweden)

Emilio Volpi

2010-01-01

Full Text Available A mixed-signal embedded system called Intelligent Sensor InterFace (ISIF suited to fast identify, trim, and verify an architecture to interface a given sensor is presented. This system has been developed according to a platform-based design approach, a methodology that has proved to be efficient for building complex mixed-signal embedded systems with short time-to-market. Such platform consists in a wide set of optimized high-performance analog, digital, and software intellectual property (IP modules for various kinds of sensors. These IPs can be easily defined for fast prototyping of the interface circuit for the given sensor. Final ASIC implementation for the given sensor conditioning can be easily derived with reduced risk and short development time. Some case examples are presented to demonstrate the effectiveness and flexibility of this system.

A Mixed-Signal Embedded Platform for Automotive Sensor Conditioning

Directory of Open Access Journals (Sweden)

Giambastiani Adolfo

2010-01-01

Full Text Available Abstract A mixed-signal embedded system called Intelligent Sensor InterFace (ISIF suited to fast identify, trim, and verify an architecture to interface a given sensor is presented. This system has been developed according to a platform-based design approach, a methodology that has proved to be efficient for building complex mixed-signal embedded systems with short time-to-market. Such platform consists in a wide set of optimized high-performance analog, digital, and software intellectual property (IP modules for various kinds of sensors. These IPs can be easily defined for fast prototyping of the interface circuit for the given sensor. Final ASIC implementation for the given sensor conditioning can be easily derived with reduced risk and short development time. Some case examples are presented to demonstrate the effectiveness and flexibility of this system.

Analogue and Mixed-Signal Integrated Circuits for Space Applications

CERN Document Server

2014-01-01

The purpose of AMICSA 2014 (organised in collaboration of ESA and CERN) is to provide an international forum for the presentation and discussion of recent advances in analogue and mixed-signal VLSI design techniques and technologies for space applications.

Repeatability study of replicate crash tests: A signal analysis approach.

Science.gov (United States)

Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

2017-10-03

To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

Mixed methods research in mental health nursing.

Science.gov (United States)

Kettles, A M; Creswell, J W; Zhang, W

2011-08-01

Mixed methods research is becoming more widely used in order to answer research questions and to investigate research problems in mental health and psychiatric nursing. However, two separate literature searches, one in Scotland and one in the USA, revealed that few mental health nursing studies identified mixed methods research in their titles. Many studies used the term 'embedded' but few studies identified in the literature were mixed methods embedded studies. The history, philosophical underpinnings, definition, types of mixed methods research and associated pragmatism are discussed, as well as the need for mixed methods research. Examples of mental health nursing mixed methods research are used to illustrate the different types of mixed methods: convergent parallel, embedded, explanatory and exploratory in their sequential and concurrent combinations. Implementing mixed methods research is also discussed briefly and the problem of identifying mixed methods research in mental and psychiatric nursing are discussed with some possible solutions to the problem proposed. © 2011 Blackwell Publishing.

A demonstration of mixed-methods research in the health sciences.

Science.gov (United States)

Katz, Janet; Vandermause, Roxanne; McPherson, Sterling; Barbosa-Leiker, Celestina

2016-11-18

Background The growth of patient, community and population-centred nursing research is a rationale for the use of research methods that can examine complex healthcare issues, not only from a biophysical perspective, but also from cultural, psychosocial and political viewpoints. This need for multiple perspectives requires mixed-methods research. Philosophy and practicality are needed to plan, conduct, and make mixed-methods research more broadly accessible to the health sciences research community. The traditions and dichotomy between qualitative and quantitative research makes the application of mixed methods a challenge. Aim To propose an integrated model for a research project containing steps from start to finish, and to use the unique strengths brought by each approach to meet the health needs of patients and communities. Discussion Mixed-methods research is a practical approach to inquiry, that focuses on asking questions and how best to answer them to improve the health of individuals, communities and populations. An integrated model of research begins with the research question(s) and moves in a continuum. The lines dividing methods do not dissolve, but become permeable boundaries where two or more methods can be used to answer research questions more completely. Rigorous and expert methodologists work together to solve common problems. Conclusion Mixed-methods research enables discussion among researchers from varied traditions. There is a plethora of methodological approaches available. Combining expertise by communicating across disciplines and professions is one way to tackle large and complex healthcare issues. Implications for practice The model presented in this paper exemplifies the integration of multiple approaches in a unified focus on identified phenomena. The dynamic nature of the model signals a need to be open to the data generated and the methodological directions implied by findings.

Text-in-context: a method for extracting findings in mixed-methods mixed research synthesis studies.

Science.gov (United States)

Sandelowski, Margarete; Leeman, Jennifer; Knafl, Kathleen; Crandell, Jamie L

2013-06-01

Our purpose in this paper is to propose a new method for extracting findings from research reports included in mixed-methods mixed research synthesis studies. International initiatives in the domains of systematic review and evidence synthesis have been focused on broadening the conceptualization of evidence, increased methodological inclusiveness and the production of evidence syntheses that will be accessible to and usable by a wider range of consumers. Initiatives in the general mixed-methods research field have been focused on developing truly integrative approaches to data analysis and interpretation. The data extraction challenges described here were encountered, and the method proposed for addressing these challenges was developed, in the first year of the ongoing (2011-2016) study: Mixed-Methods Synthesis of Research on Childhood Chronic Conditions and Family. To preserve the text-in-context of findings in research reports, we describe a method whereby findings are transformed into portable statements that anchor results to relevant information about sample, source of information, time, comparative reference point, magnitude and significance and study-specific conceptions of phenomena. The data extraction method featured here was developed specifically to accommodate mixed-methods mixed research synthesis studies conducted in nursing and other health sciences, but reviewers might find it useful in other kinds of research synthesis studies. This data extraction method itself constitutes a type of integration to preserve the methodological context of findings when statements are read individually and in comparison to each other. © 2012 Blackwell Publishing Ltd.

Developing a reliable signal wire attachment method for rail.

Science.gov (United States)

2014-11-01

The goal of this project was to develop a better attachment method for rail signal wires to improve the reliability of signaling : systems. EWI conducted basic research into the failure mode of current attachment methods and developed and tested a ne...

Addressing Phase Errors in Fat-Water Imaging Using a Mixed Magnitude/Complex Fitting Method

Science.gov (United States)

Hernando, D.; Hines, C. D. G.; Yu, H.; Reeder, S.B.

2012-01-01

Accurate, noninvasive measurements of liver fat content are needed for the early diagnosis and quantitative staging of nonalcoholic fatty liver disease. Chemical shift-based fat quantification methods acquire images at multiple echo times using a multiecho spoiled gradient echo sequence, and provide fat fraction measurements through postprocessing. However, phase errors, such as those caused by eddy currents, can adversely affect fat quantification. These phase errors are typically most significant at the first echo of the echo train, and introduce bias in complex-based fat quantification techniques. These errors can be overcome using a magnitude-based technique (where the phase of all echoes is discarded), but at the cost of significantly degraded signal-to-noise ratio, particularly for certain choices of echo time combinations. In this work, we develop a reconstruction method that overcomes these phase errors without the signal-to-noise ratio penalty incurred by magnitude fitting. This method discards the phase of the first echo (which is often corrupted) while maintaining the phase of the remaining echoes (where phase is unaltered). We test the proposed method on 104 patient liver datasets (from 52 patients, each scanned twice), where the fat fraction measurements are compared to coregistered spectroscopy measurements. We demonstrate that mixed fitting is able to provide accurate fat fraction measurements with high signal-to-noise ratio and low bias over a wide choice of echo combinations. PMID:21713978

Automated Design Tools for Integrated Mixed-Signal Microsystems (NeoCAD)

National Research Council Canada - National Science Library

Petre, P; Visher, J; Shringarpure, R; Valley, F; Swaminathan, M

2005-01-01

Automated design tools and integrated design flow methodologies were developed that demonstrated more than an order- of-magnitude reduction in cycle time and cost for mixed signal (digital/analoglRF...

Effect of mixing methods and aggregate type on strength of hardened concrete

International Nuclear Information System (INIS)

Elhadi, S.

2006-01-01

The objective of the research contained in this paper is to study the effect on strength of concrete which can be caused by changing method of concrete mix with or without changing aggregate crushing value under hand or mechanical compaction, and to compare results obtained when nondestructive testing techniques are used. It has been found that all methods of mix design are nearly identical in predicting the strength under a known value of w/c ratio. Up to strength of about 30 N/mm 2 , hand and mechanical compaction seems to be identical in all methods of concrete mixing. Important results regarding destructive and non-destructive testing has been drawn from the study.(Author)

Pragmatism, Evidence, and Mixed Methods Evaluation

Science.gov (United States)

Hall, Jori N.

2013-01-01

Mixed methods evaluation has a long-standing history of enhancing the credibility of evaluation findings. However, using mixed methods in a utilitarian way implicitly emphasizes convenience over engaging with its philosophical underpinnings (Denscombe, 2008). Because of this, some mixed methods evaluators and social science researchers have been…

Why, and how, mixed methods research is undertaken in health services research in England: a mixed methods study

Science.gov (United States)

O'Cathain, Alicia; Murphy, Elizabeth; Nicholl, Jon

2007-01-01

Background Recently, there has been a surge of international interest in combining qualitative and quantitative methods in a single study – often called mixed methods research. It is timely to consider why and how mixed methods research is used in health services research (HSR). Methods Documentary analysis of proposals and reports of 75 mixed methods studies funded by a research commissioner of HSR in England between 1994 and 2004. Face-to-face semi-structured interviews with 20 researchers sampled from these studies. Results 18% (119/647) of HSR studies were classified as mixed methods research. In the documentation, comprehensiveness was the main driver for using mixed methods research, with researchers wanting to address a wider range of questions than quantitative methods alone would allow. Interviewees elaborated on this, identifying the need for qualitative research to engage with the complexity of health, health care interventions, and the environment in which studies took place. Motivations for adopting a mixed methods approach were not always based on the intrinsic value of mixed methods research for addressing the research question; they could be strategic, for example, to obtain funding. Mixed methods research was used in the context of evaluation, including randomised and non-randomised designs; survey and fieldwork exploratory studies; and instrument development. Studies drew on a limited number of methods – particularly surveys and individual interviews – but used methods in a wide range of roles. Conclusion Mixed methods research is common in HSR in the UK. Its use is driven by pragmatism rather than principle, motivated by the perceived deficit of quantitative methods alone to address the complexity of research in health care, as well as other more strategic gains. Methods are combined in a range of contexts, yet the emerging methodological contributions from HSR to the field of mixed methods research are currently limited to the single

Patch testing with the "sesquiterpene lactone mix"

DEFF Research Database (Denmark)

Ducombs, G; Benezra, C; Talaga, P

1990-01-01

6278 patients were patch tested with a sesquiterpene lactone mix (SL-mix) in 10 European clinics. 4011 patients were tested only with 0.1% SL-mix, 63 (approximately 1.5%) of whom were positive, with 26 (41%) of these cases being considered clinically relevant. There were no cases of active...

An adaptive image sparse reconstruction method combined with nonlocal similarity and cosparsity for mixed Gaussian-Poisson noise removal

Science.gov (United States)

Chen, Yong-fei; Gao, Hong-xia; Wu, Zi-ling; Kang, Hui

2018-01-01

Compressed sensing (CS) has achieved great success in single noise removal. However, it cannot restore the images contaminated with mixed noise efficiently. This paper introduces nonlocal similarity and cosparsity inspired by compressed sensing to overcome the difficulties in mixed noise removal, in which nonlocal similarity explores the signal sparsity from similar patches, and cosparsity assumes that the signal is sparse after a possibly redundant transform. Meanwhile, an adaptive scheme is designed to keep the balance between mixed noise removal and detail preservation based on local variance. Finally, IRLSM and RACoSaMP are adopted to solve the objective function. Experimental results demonstrate that the proposed method is superior to conventional CS methods, like K-SVD and state-of-art method nonlocally centralized sparse representation (NCSR), in terms of both visual results and quantitative measures.

Association between positive patch tests to epoxy resin and fragrance mix I ingredients

DEFF Research Database (Denmark)

Andersen, Klaus Ejner; Christensen, Lars Porskjaer; Vølund, Aage

2009-01-01

and possibly reproduce this association with the use of TRUE((R)) test data and supplementary tests with fragrance mix ingredients from the Department of Dermatology, Odense University Hospital. MATERIALS AND METHODS: Six thousand one hundred and fifteen consecutive eczema patients tested from 1995 to 2007......BACKGROUND: Both epoxy resin (diglycidyl ether of bisphenol A) and fragrance mix I are included in the European baseline series of contact allergens. A significant association between positive reactions to epoxy resin and fragrance mix has been reported by others. OBJECTIVE: To investigate...... were included, and test results from all patients tested with fragrance mix ingredients were analysed. RESULTS: One hundred and forty-five (2.4%) were positive to epoxy resin and 282 (4.6%) were positive to fragrance mix I. Nineteen were positive to both giving an odds ratio of 3.3, which...

Patch testing with constituents of Compositae mixes.

Science.gov (United States)

Paulsen, Evy; Andersen, Klaus E

2012-05-01

The development of mixes containing Compositae plant extracts has improved the diagnosis of Compositae contact allergy, but none of them has fulfilled the criteria for an ideal European plant mix. To evaluate which constituents of two commercial Compositae mixes were most useful as screening agents. These comprised 76 patients testing positive to Compositae mix 6% in petrolatum and 29 patients testing positive to Compositae mix 5% pet., all of whom were tested with constituents of the respective mixes. The majority of patients tested positive to parthenolide or parthenolide-containing extracts, followed by German chamomile, yarrow, and arnica. As German chamomile is a weak sensitizer, the results suggest cross-reactions or reactions to unknown allergens. No one was positive to Roman chamomile. Even though parthenolide seems to be a suitable supplement to the baseline series, the results emphasize that it is important to patch test with extracts of native or locally grown plants, not only because of the geographical variation, but also because of the potential unknown allergens contained in short ether preparations and the variability in the individual patient's exposure and cross-reaction patterns. © 2012 John Wiley & Sons A/S.

Qualitative Approaches to Mixed Methods Practice

Science.gov (United States)

Hesse-Biber, Sharlene

2010-01-01

This article discusses how methodological practices can shape and limit how mixed methods is practiced and makes visible the current methodological assumptions embedded in mixed methods practice that can shut down a range of social inquiry. The article argues that there is a "methodological orthodoxy" in how mixed methods is practiced…

The use of "mixing" procedure of mixed methods in health services research.

Science.gov (United States)

Zhang, Wanqing; Creswell, John

2013-08-01

Mixed methods research has emerged alongside qualitative and quantitative approaches as an important tool for health services researchers. Despite growing interest, among health services researchers, in using mixed methods designs, little has been done to identify the procedural aspects of doing so. To describe how mixed methods researchers mix the qualitative and quantitative aspects of their studies in health services research. We searched the PubMed for articles, using mixed methods in health services research, published between January 1, 2006 and December 30, 2010. We identified and reviewed 30 published health services research articles on studies in which mixed methods had been used. We selected 3 articles as illustrations to help health services researcher conceptualize the type of mixing procedures that they were using. Three main "mixing" procedures have been applied within these studies: (1) the researchers analyzed the 2 types of data at the same time but separately and integrated the results during interpretation; (2) the researchers connected the qualitative and quantitative portions in phases in such a way that 1 approach was built upon the findings of the other approach; and (3) the researchers mixed the 2 data types by embedding the analysis of 1 data type within the other. "Mixing" in mixed methods is more than just the combination of 2 independent components of the quantitative and qualitative data. The use of "mixing" procedure in health services research involves the integration, connection, and embedding of these 2 data components.

Numerical simulations of eddy current testing signals of steam generator tubes by 3-D finite element method

International Nuclear Information System (INIS)

Sakai, Takayuki; Soneda, Naoki

1996-01-01

In every inspection of Japanese PWR plants, all of steam generator tubes are inspected using Eddy Current Testing (ECT) method. However, the relationships between the ECT signals and the defect shapes are known only for the representative shapes of defects. In order to improve the reliability of inspections and the capability of ECT probes, development of numerical simulation technique of the ECT signals for arbitrarily shaped defects is essential. In this study, three-dimensional finite element code is developed to simulate the ECT signals for any kinds of defects in the SG tubes. The code is fully vectorized so that it runs on the supercomputers very efficiently. The simulation results agree very well with the experimental results. Sensitivity analyses are performed to investigate the relationships between the defect shapes and the ECT signals. (author)

Moments, Mixed Methods, and Paradigm Dialogs

Science.gov (United States)

Denzin, Norman K.

2010-01-01

I reread the 50-year-old history of the qualitative inquiry that calls for triangulation and mixed methods. I briefly visit the disputes within the mixed methods community asking how did we get to where we are today, the period of mixed-multiple-methods advocacy, and Teddlie and Tashakkori's third methodological moment. (Contains 10 notes.)

Mixed Methods Research: The "Thing-ness" Problem.

Science.gov (United States)

Hesse-Biber, Sharlene

2015-06-01

Contemporary mixed methods research (MMR) veers away from a "loosely bounded" to a "bounded" concept that has important negative implications for how qualitatively driven mixed methods approaches are positioned in the field of mixed methods and overall innovation in the praxis of MMR. I deploy the concept of reification defined as taking an object/abstraction and treating it as if it were real such that it takes on the quality of "thing-ness," having a concrete independent existence. I argue that the contemporary reification of mixed methods as a "thing" is fueled by three interrelated factors: (a) the growing formalization of mixed methods as design, (b) the unexamined belief in the "synergy" of mixed methods and, (c) the deployment of a "practical pragmatism" as the "philosophical partner" for mixed methods inquiry. © The Author(s) 2015.

Mixing it but not mixed-up: mixed methods research in medical education (a critical narrative review).

Science.gov (United States)

Maudsley, Gillian

2011-01-01

Some important research questions in medical education and health services research need 'mixed methods research' (particularly synthesizing quantitative and qualitative findings). The approach is not new, but should be more explicitly reported. The broad search question here, of a disjointed literature, was thus: What is mixed methods research - how should it relate to medical education research?, focused on explicit acknowledgement of 'mixing'. Literature searching focused on Web of Knowledge supplemented by other databases across disciplines. Five main messages emerged: - Thinking quantitative and qualitative, not quantitative versus qualitative - Appreciating that mixed methods research blends different knowledge claims, enquiry strategies, and methods - Using a 'horses for courses' [whatever works] approach to the question, and clarifying the mix - Appreciating how medical education research competes with the 'evidence-based' movement, health services research, and the 'RCT' - Being more explicit about the role of mixed methods in medical education research, and the required expertise Mixed methods research is valuable, yet the literature relevant to medical education is fragmented and poorly indexed. The required time, effort, expertise, and techniques deserve better recognition. More write-ups should explicitly discuss the 'mixing' (particularly of findings), rather than report separate components.

Multipath interference test method for distributed amplifiers

Science.gov (United States)

Okada, Takahiro; Aida, Kazuo

2005-12-01

A method for testing distributed amplifiers is presented; the multipath interference (MPI) is detected as a beat spectrum between the multipath signal and the direct signal using a binary frequency shifted keying (FSK) test signal. The lightwave source is composed of a DFB-LD that is directly modulated by a pulse stream passing through an equalizer, and emits the FSK signal of the frequency deviation of about 430MHz at repetition rate of 80-100 kHz. The receiver consists of a photo-diode and an electrical spectrum analyzer (ESA). The base-band power spectrum peak appeared at the frequency of the FSK frequency deviation can be converted to amount of MPI using a calibration chart. The test method has improved the minimum detectable MPI as low as -70 dB, compared to that of -50 dB of the conventional test method. The detailed design and performance of the proposed method are discussed, including the MPI simulator for calibration procedure, computer simulations for evaluating the error caused by the FSK repetition rate and the fiber length under test and experiments on singlemode fibers and distributed Raman amplifier.

An improved method based on wavelet coefficient correlation to filter noise in Doppler ultrasound blood flow signals

Science.gov (United States)

Wan, Renzhi; Zu, Yunxiao; Shao, Lin

2018-04-01

The blood echo signal maintained through Medical ultrasound Doppler devices would always include vascular wall pulsation signal .The traditional method to de-noise wall signal is using high-pass filter, which will also remove the lowfrequency part of the blood flow signal. Some scholars put forward a method based on region selective reduction, which at first estimates of the wall pulsation signals and then removes the wall signal from the mixed signal. Apparently, this method uses the correlation between wavelet coefficients to distinguish blood signal from wall signal, but in fact it is a kind of wavelet threshold de-noising method, whose effect is not so much ideal. In order to maintain a better effect, this paper proposes an improved method based on wavelet coefficient correlation to separate blood signal and wall signal, and simulates the algorithm by computer to verify its validity.

Adaptive variational mode decomposition method for signal processing based on mode characteristic

Science.gov (United States)

Lian, Jijian; Liu, Zhuo; Wang, Haijun; Dong, Xiaofeng

2018-07-01

Variational mode decomposition is a completely non-recursive decomposition model, where all the modes are extracted concurrently. However, the model requires a preset mode number, which limits the adaptability of the method since a large deviation in the number of mode set will cause the discard or mixing of the mode. Hence, a method called Adaptive Variational Mode Decomposition (AVMD) was proposed to automatically determine the mode number based on the characteristic of intrinsic mode function. The method was used to analyze the simulation signals and the measured signals in the hydropower plant. Comparisons have also been conducted to evaluate the performance by using VMD, EMD and EWT. It is indicated that the proposed method has strong adaptability and is robust to noise. It can determine the mode number appropriately without modulation even when the signal frequencies are relatively close.

Using mixed methods in health research.

OpenAIRE

Tariq, S.; Woodman, J.

2013-01-01

Mixed methods research is the use of quantitative and qualitative methods in a single study or series of studies. It is an emergent methodology which is increasingly used by health researchers, especially within health services research. There is a growing literature on the theory, design and critical appraisal of mixed methods research. However, there are few papers that summarize this methodological approach for health practitioners who wish to conduct or critically engage with mixed method...

Safety analysis of urban signalized intersections under mixed traffic.

Science.gov (United States)

S, Anjana; M V L R, Anjaneyulu

2015-02-01

This study examined the crash causative factors of signalized intersections under mixed traffic using advanced statistical models. Hierarchical Poisson regression and logistic regression models were developed to predict the crash frequency and severity of signalized intersection approaches. The prediction models helped to develop general safety countermeasures for signalized intersections. The study shows that exclusive left turn lanes and countdown timers are beneficial for improving the safety of signalized intersections. Safety is also influenced by the presence of a surveillance camera, green time, median width, traffic volume, and proportion of two wheelers in the traffic stream. The factors that influence the severity of crashes were also identified in this study. As a practical application, the safe values of deviation of green time provided from design green time, with varying traffic volume, is presented in this study. This is a useful tool for setting the appropriate green time for a signalized intersection approach with variations in the traffic volume. Copyright © 2014 Elsevier Ltd. All rights reserved.

RO1 Funding for Mixed Methods Research: Lessons learned from the Mixed-Method Analysis of Japanese Depression Project

OpenAIRE

Arnault, Denise Saint; Fetters, Michael D.

2011-01-01

Mixed methods research has made significant in-roads in the effort to examine complex health related phenomenon. However, little has been published on the funding of mixed methods research projects. This paper addresses that gap by presenting an example of an NIMH funded project using a mixed methods QUAL-QUAN triangulation design entitled “The Mixed-Method Analysis of Japanese Depression.” We present the Cultural Determinants of Health Seeking model that framed the study, the specific aims, ...

Mixed methods research in music therapy research.

Science.gov (United States)

Bradt, Joke; Burns, Debra S; Creswell, John W

2013-01-01

Music therapists have an ethical and professional responsibility to provide the highest quality care possible to their patients. Much of the time, high quality care is guided by evidence-based practice standards that integrate the most current, available research in making decisions. Accordingly, music therapists need research that integrates multiple ways of knowing and forms of evidence. Mixed methods research holds great promise for facilitating such integration. At this time, there have not been any methodological articles published on mixed methods research in music therapy. The purpose of this article is to introduce mixed methods research as an approach to address research questions relevant to music therapy practice. This article describes the core characteristics of mixed methods research, considers paradigmatic issues related to this research approach, articulates major challenges in conducting mixed methods research, illustrates four basic designs, and provides criteria for evaluating the quality of mixed methods articles using examples of mixed methods research from the music therapy literature. Mixed methods research offers unique opportunities for strengthening the evidence base in music therapy. Recommendations are provided to ensure rigorous implementation of this research approach.

A scoring system for appraising mixed methods research, and concomitantly appraising qualitative, quantitative and mixed methods primary studies in Mixed Studies Reviews.

Science.gov (United States)

Pluye, Pierre; Gagnon, Marie-Pierre; Griffiths, Frances; Johnson-Lafleur, Janique

2009-04-01

A new form of literature review has emerged, Mixed Studies Review (MSR). These reviews include qualitative, quantitative and mixed methods studies. In the present paper, we examine MSRs in health sciences, and provide guidance on processes that should be included and reported. However, there are no valid and usable criteria for concomitantly appraising the methodological quality of the qualitative, quantitative and mixed methods studies. To propose criteria for concomitantly appraising the methodological quality of qualitative, quantitative and mixed methods studies or study components. A three-step critical review was conducted. 2322 references were identified in MEDLINE, and their titles and abstracts were screened; 149 potentially relevant references were selected and the full-text papers were examined; 59 MSRs were retained and scrutinized using a deductive-inductive qualitative thematic data analysis. This revealed three types of MSR: convenience, reproducible, and systematic. Guided by a proposal, we conducted a qualitative thematic data analysis of the quality appraisal procedures used in the 17 systematic MSRs (SMSRs). Of 17 SMSRs, 12 showed clear quality appraisal procedures with explicit criteria but no SMSR used valid checklists to concomitantly appraise qualitative, quantitative and mixed methods studies. In two SMSRs, criteria were developed following a specific procedure. Checklists usually contained more criteria than needed. In four SMSRs, a reliability assessment was described or mentioned. While criteria for quality appraisal were usually based on descriptors that require specific methodological expertise (e.g., appropriateness), no SMSR described the fit between reviewers' expertise and appraised studies. Quality appraisal usually resulted in studies being ranked by methodological quality. A scoring system is proposed for concomitantly appraising the methodological quality of qualitative, quantitative and mixed methods studies for SMSRs. This

Mixed Methods, Triangulation, and Causal Explanation

Science.gov (United States)

Howe, Kenneth R.

2012-01-01

This article distinguishes a disjunctive conception of mixed methods/triangulation, which brings different methods to bear on different questions, from a conjunctive conception, which brings different methods to bear on the same question. It then examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates…

HIV Testing and Care in Canadian Aboriginal Youth: A community based mixed methods study

Directory of Open Access Journals (Sweden)

Myers Ted

2008-10-01

Full Text Available Abstract Background HIV infection is a serious concern in the Canadian Aboriginal population, particularly among youth; however, there is limited attention to this issue in research literature. The purpose of this national study was to explore HIV testing and care decisions of Canadian Aboriginal youth. Methods A community-based mixed-method design incorporating the Aboriginal research principles of Ownership, Control, Access and Possession (OCAP was used. Data were collected through surveys (n = 413 and qualitative interviews (n = 28. Eleven community-based organizations including urban Aboriginal AIDS service organizations and health and friendship centres in seven provinces and one territory assisted with the recruitment of youth (15 to 30 years. Results Average age of survey participants was 21.5 years (median = 21.0 years and qualitative interview participants was 24.4 years (median = 24.0. Fifty-one percent of the survey respondents (210 of 413 youth and 25 of 28 interview participants had been tested for HIV. The most common reason to seek testing was having sex without a condom (43.6% or pregnancy (35.4% while common reasons for not testing were the perception of being low HIV risk (45.3% or not having had sex with an infected person (34.5%. Among interviewees, a contributing reason for not testing was feeling invulnerable. Most surveyed youth tested in the community in which they lived (86.5% and 34.1% visited a physician for the test. The majority of surveyed youth (60.0% had tested once or twice in the previous 2 years, however, about one-quarter had tested more than twice. Among the 26 surveyed youth who reported that they were HIV-positive, 6 (23.1% had AIDS at the time of diagnosis. Delays in care-seeking after diagnosis varied from a few months to seven years from time of test. Conclusion It is encouraging that many youth who had tested for HIV did so based on a realistic self-assessment of HIV risk behaviours; however, for others

The MIXED framework: A novel approach to evaluating mixed-methods rigor.

Science.gov (United States)

Eckhardt, Ann L; DeVon, Holli A

2017-10-01

Evaluation of rigor in mixed-methods (MM) research is a persistent challenge due to the combination of inconsistent philosophical paradigms, the use of multiple research methods which require different skill sets, and the need to combine research at different points in the research process. Researchers have proposed a variety of ways to thoroughly evaluate MM research, but each method fails to provide a framework that is useful for the consumer of research. In contrast, the MIXED framework is meant to bridge the gap between an academic exercise and practical assessment of a published work. The MIXED framework (methods, inference, expertise, evaluation, and design) borrows from previously published frameworks to create a useful tool for the evaluation of a published study. The MIXED framework uses an experimental eight-item scale that allows for comprehensive integrated assessment of MM rigor in published manuscripts. Mixed methods are becoming increasingly prevalent in nursing and healthcare research requiring researchers and consumers to address issues unique to MM such as evaluation of rigor. © 2017 John Wiley & Sons Ltd.

Mapping Mixed Methods Research: Methods, Measures, and Meaning

Science.gov (United States)

Wheeldon, J.

2010-01-01

This article explores how concept maps and mind maps can be used as data collection tools in mixed methods research to combine the clarity of quantitative counts with the nuance of qualitative reflections. Based on more traditional mixed methods approaches, this article details how the use of pre/post concept maps can be used to design qualitative…

Mixing and sampling tests for Radiochemical Plant

International Nuclear Information System (INIS)

Ehinger, M.N.; Marfin, H.R.; Hunt, B.

1999-01-01

The paper describes results and test procedures used to evaluate uncertainly and basis effects introduced by the sampler systems of a radiochemical plant, and similar parameters associated with mixing. This report will concentrate on experiences at the Barnwell Nuclear Fuels Plant. Mixing and sampling tests can be conducted to establish the statistical parameters for those activities related to overall measurement uncertainties. Density measurements by state-of-the art, commercially availability equipment is the key to conducting those tests. Experience in the U.S. suggests the statistical contribution of mixing and sampling can be controlled to less than 0.01 % and with new equipment and new tests in operating facilities might be controlled to better accuracy [ru

Statistical Tests for Mixed Linear Models

CERN Document Server

Khuri, André I; Sinha, Bimal K

2011-01-01

An advanced discussion of linear models with mixed or random effects. In recent years a breakthrough has occurred in our ability to draw inferences from exact and optimum tests of variance component models, generating much research activity that relies on linear models with mixed and random effects. This volume covers the most important research of the past decade as well as the latest developments in hypothesis testing. It compiles all currently available results in the area of exact and optimum tests for variance component models and offers the only comprehensive treatment for these models a

Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India.

Science.gov (United States)

Sarkar, Archana; Mburu, Gitau; Shivkumar, Poonam Varma; Sharma, Pankhuri; Campbell, Fiona; Behera, Jagannath; Dargan, Ritu; Mishra, Surendra Kumar; Mehra, Sunil

2016-01-01

HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India. A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick(®) HIV antibody test, and subsequently asked to self-test under supervision of a community health worker. Test results were confirmed at a government-run integrated counselling and testing centre. A questionnaire was used to obtain information on patient demographics and the ease, acceptability and difficulties of self-testing. In-depth interviews were conducted with a sub-sample of 35 participants to understand their experiences. In total, 202 participants performed the non-invasive, oral fluid-based, rapid test under supervision for HIV screening. Acceptance rate was 100%. Motivators for self-testing included: ease of testing (43.4%), quick results (27.3%) and non-invasive procedure (23.2%). Sensitivity and specificity were 100% for 201 tests, and one test was invalid. Concordance of test result interpretation between community health workers and participants was 98.5% with a Cohen's Kappa (k) value of k=0.566 with pwomen in rural India. Participants were supportive of making self-testing publicly available. Policy guidelines and implementation research are required to advance HIV self-testing for larger populations at scale.

Method of signal analysis

International Nuclear Information System (INIS)

Berthomier, Charles

1975-01-01

A method capable of handling the amplitude and the frequency time laws of a certain kind of geophysical signals is described here. This method is based upon the analytical signal idea of Gabor and Ville, which is constructed either in the time domain by adding an imaginary part to the real signal (in-quadrature signal), or in the frequency domain by suppressing negative frequency components. The instantaneous frequency of the initial signal is then defined as the time derivative of the phase of the analytical signal, and his amplitude, or envelope, as the modulus of this complex signal. The method is applied to three types of magnetospheric signals: chorus, whistlers and pearls. The results obtained by analog and numerical calculations are compared to results obtained by classical systems using filters, i.e. based upon a different definition of the concept of frequency. The precision with which the frequency-time laws are determined leads then to the examination of the principle of the method and to a definition of instantaneous power density spectrum attached to the signal, and to the first consequences of this definition. In this way, a two-dimensional representation of the signal is introduced which is less deformed by the analysis system properties than the usual representation, and which moreover has the advantage of being obtainable practically in real time [fr

Estimation of the common cause failure probabilities of the components under mixed testing schemes

International Nuclear Information System (INIS)

Kang, Dae Il; Hwang, Mee Jeong; Han, Sang Hoon

2009-01-01

For the case where trains or channels of standby safety systems consisting of more than two redundant components are tested in a staggered manner, the standby safety components within a train can be tested simultaneously or consecutively. In this case, mixed testing schemes, staggered and non-staggered testing schemes, are used for testing the components. Approximate formulas, based on the basic parameter method, were developed for the estimation of the common cause failure (CCF) probabilities of the components under mixed testing schemes. The developed formulas were applied to the four redundant check valves of the auxiliary feed water system as a demonstration study for their appropriateness. For a comparison, we estimated the CCF probabilities of the four redundant check valves for the mixed, staggered, and non-staggered testing schemes. The CCF probabilities of the four redundant check valves for the mixed testing schemes were estimated to be higher than those for the staggered testing scheme, and lower than those for the non-staggered testing scheme.

Methodological Reporting in Qualitative, Quantitative, and Mixed Methods Health Services Research Articles

Science.gov (United States)

Wisdom, Jennifer P; Cavaleri, Mary A; Onwuegbuzie, Anthony J; Green, Carla A

2012-01-01

Objectives Methodologically sound mixed methods research can improve our understanding of health services by providing a more comprehensive picture of health services than either method can alone. This study describes the frequency of mixed methods in published health services research and compares the presence of methodological components indicative of rigorous approaches across mixed methods, qualitative, and quantitative articles. Data Sources All empirical articles (n = 1,651) published between 2003 and 2007 from four top-ranked health services journals. Study Design All mixed methods articles (n = 47) and random samples of qualitative and quantitative articles were evaluated to identify reporting of key components indicating rigor for each method, based on accepted standards for evaluating the quality of research reports (e.g., use of p-values in quantitative reports, description of context in qualitative reports, and integration in mixed method reports). We used chi-square tests to evaluate differences between article types for each component. Principal Findings Mixed methods articles comprised 2.85 percent (n = 47) of empirical articles, quantitative articles 90.98 percent (n = 1,502), and qualitative articles 6.18 percent (n = 102). There was a statistically significant difference (χ2(1) = 12.20, p = .0005, Cramer's V = 0.09, odds ratio = 1.49 [95% confidence interval = 1,27, 1.74]) in the proportion of quantitative methodological components present in mixed methods compared to quantitative papers (21.94 versus 47.07 percent, respectively) but no statistically significant difference (χ2(1) = 0.02, p = .89, Cramer's V = 0.01) in the proportion of qualitative methodological components in mixed methods compared to qualitative papers (21.34 versus 25.47 percent, respectively). Conclusion Few published health services research articles use mixed methods. The frequency of key methodological components is variable. Suggestions are provided to increase the

Mixed-Signal Hardware Security: Attacks and Countermeasures for ΔΣ ADC

Directory of Open Access Journals (Sweden)

Shayan Taheri

2017-08-01

Full Text Available Mixed-signal integrated circuits (ICs play an eminent and critical role in design and development of the embedded systems leveraged within smart weapons and military systems. These ICs can be a golden target for adversaries to compromise in order to function maliciously. In this work, we study the security aspects of a tunnel field effect transistor (TFET-based first-order one-bit delta-sigma ( Δ Σ analog to digital converter (ADC through proposing four attack and one defense models. The first attack manipulates the input signal to the Δ Σ modulator. The second attack manipulates the analog version of the modulator output bit and is triggered by the noise signal. The third attack manipulates the modulator output bit and has a controllable trigger mechanism. The fourth attack manipulates the analog version of the modulator output bit and is triggered by a victim capacitance within the chip. For the defense, a number of signal processing filters are used in order to purge the analog version of the modulator output bit for elimination of the malicious unwanted features, introduced by the attacks. According to the simulation results, the second threat model displays the strongest attack. Derived from the countermeasure evaluation, the best filter to confront the threat models is the robust regression using the least absolute residual computing method.

A general mixed boundary model reduction method for component mode synthesis

International Nuclear Information System (INIS)

Voormeeren, S N; Van der Valk, P L C; Rixen, D J

2010-01-01

A classic issue in component mode synthesis (CMS) methods is the choice for fixed or free boundary conditions at the interface degrees of freedom (DoF) and the associated vibration modes in the components reduction base. In this paper, a novel mixed boundary CMS method called the 'Mixed Craig-Bampton' method is proposed. The method is derived by dividing the substructure DoF into a set of internal DoF, free interface DoF and fixed interface DoF. To this end a simple but effective scheme is introduced that, for every pair of interface DoF, selects a free or fixed boundary condition for each DoF individually. Based on this selection a reduction basis is computed consisting of vibration modes, static constraint modes and static residual flexibility modes. In order to assemble the reduced substructures a novel mixed assembly procedure is developed. It is shown that this approach leads to relatively sparse reduced matrices, whereas other mixed boundary methods often lead to full matrices. As such, the Mixed Craig-Bampton method forms a natural generalization of the classic Craig-Bampton and more recent Dual Craig-Bampton methods. Finally, the method is applied to a finite element test model. Analysis reveals that the proposed method has comparable or better accuracy and superior versatility with respect to the existing methods.

Mixed price and load forecasting of electricity markets by a new iterative prediction method

International Nuclear Information System (INIS)

Amjady, Nima; Daraeepour, Ali

2009-01-01

Load and price forecasting are the two key issues for the participants of current electricity markets. However, load and price of electricity markets have complex characteristics such as nonlinearity, non-stationarity and multiple seasonality, to name a few (usually, more volatility is seen in the behavior of electricity price signal). For these reasons, much research has been devoted to load and price forecast, especially in the recent years. However, previous research works in the area separately predict load and price signals. In this paper, a mixed model for load and price forecasting is presented, which can consider interactions of these two forecast processes. The mixed model is based on an iterative neural network based prediction technique. It is shown that the proposed model can present lower forecast errors for both load and price compared with the previous separate frameworks. Another advantage of the mixed model is that all required forecast features (from load or price) are predicted within the model without assuming known values for these features. So, the proposed model can better be adapted to real conditions of an electricity market. The forecast accuracy of the proposed mixed method is evaluated by means of real data from the New York and Spanish electricity markets. The method is also compared with some of the most recent load and price forecast techniques. (author)

ADVANCING THE STUDY OF VIOLENCE AGAINST WOMEN USING MIXED METHODS: INTEGRATING QUALITATIVE METHODS INTO A QUANTITATIVE RESEARCH PROGRAM

Science.gov (United States)

Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol

2011-01-01

A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032

The Signal Validation method of Digital Process Instrumentation System on signal conditioner for SMART

International Nuclear Information System (INIS)

Moon, Hee Gun; Park, Sang Min; Kim, Jung Seon; Shon, Chang Ho; Park, Heui Youn; Koo, In Soo

2005-01-01

The function of PIS(Process Instrumentation System) for SMART is to acquire the process data from sensor or transmitter. The PIS consists of signal conditioner, A/D converter, DSP(Digital Signal Process) and NIC(Network Interface Card). So, It is fully digital system after A/D converter. The PI cabinet and PDAS(Plant Data Acquisition System) in commercial plant is responsible for data acquisition of the sensor or transmitter include RTD, TC, level, flow, pressure and so on. The PDAS has the software that processes each sensor data and PI cabinet has the signal conditioner, which is need for maintenance and test. The signal conditioner has the potentiometer to adjust the span and zero for test and maintenance. The PIS of SMART also has the signal conditioner which has the span and zero adjust same as the commercial plant because the signal conditioner perform the signal condition for AD converter such as 0∼10Vdc. But, To adjust span and zero is manual test and calibration. So, This paper presents the method of signal validation and calibration, which is used by digital feature in SMART. There are I/E(current to voltage), R/E(resistor to voltage), F/E(frequency to voltage), V/V(voltage to voltage). Etc. In this paper show only the signal validation and calibration about I/E converter that convert level, pressure, flow such as 4∼20mA into signal for AD conversion such as 0∼10Vdc

A Channelization-Based DOA Estimation Method for Wideband Signals

Directory of Open Access Journals (Sweden)

Rui Guo

2016-07-01

Full Text Available In this paper, we propose a novel direction of arrival (DOA estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR using direct wideband radio frequency (RF digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method.

Field measurement of mixing degree in coal mixer by later activable tracer method

International Nuclear Information System (INIS)

Yokooji, Makoto; Uemura, Katsumi; Adachi, Syoichi

1975-01-01

Mixing effectiveness in a rotary drum mixer for coke production was examined. Though the method to use the dispersion of characteristic values such as ash content or volatile components is common for measuring the mixing effectiveness, here the later activable tracer method with radioisotopes was employed, because the former method includes the dispersion of the characteristic values for raw materials themselves, and is poor in detectability. In a preliminary test, the expression for mixing degree was determined, and the tracer nuclide was selected. Coal mixture was irradiated in the TRIGA II reactor of St. Paul University for 4 hours at 100 kW. then further preliminary test was performed for La and Mn which were selected among the typical usable elements listed up by reviewing their γ-spectra. Finally, Mn was adopted by comparing both elements regarding their time required for activation analysis and economy. Manganese concentration originally contained in the coal mixture was 38 ppm. Mixing degree after passing through the coal mixer was 99.8%. The results of the regular test are shown in a table, and indicate that the mixer fully attained its aim. (Wakatsuki, Y.)

Efficiency test of filtering methods for the removal of transcranial magnetic stimulation artifacts on human electroencephalography with artificially transcranial magnetic stimulation-corrupted signals

Science.gov (United States)

Zilber, Nicolas A.; Katayama, Yoshinori; Iramina, Keiji; Erich, Wintermantel

2010-05-01

A new approach is proposed to test the efficiency of methods, such as the Kalman filter and the independent component analysis (ICA), when applied to remove the artifacts induced by transcranial magnetic stimulation (TMS) from electroencephalography (EEG). By using EEG recordings corrupted by TMS induction, the shape of the artifacts is approximately described with a model based on an equivalent circuit simulation. These modeled artifacts are subsequently added to other EEG signals—this time not influenced by TMS. The resulting signals prove of interest since we also know their form without the pseudo-TMS artifacts. Therefore, they enable us to use a fit test to compare the signals we obtain after removing the artifacts with the original signals. This efficiency test turned out very useful in comparing the methods between them, as well as in determining the parameters of the filtering that give satisfactory results with the automatic ICA.

Critical Appraisal of Mixed Methods Studies

Science.gov (United States)

Heyvaert, Mieke; Hannes, Karin; Maes, Bea; Onghena, Patrick

2013-01-01

In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

Application of orthogonal test method in mix proportion design of recycled lightweight aggregate concrete

Science.gov (United States)

Zhao, Zhanshan; An, Le; Zhang, Yijing; Yuan, Jie

2017-03-01

Recycled lightweight aggregate concrete was made with construction waste and ceramsite brick mainly including brick. Using the orthogonal test method, the mix proportion of recycled lightweight aggregate concrete was studied, and the Influence regularity and significance of water binder ratio, fly ash, sand ratio, the amount of recycled aggregate proportion on the compressive strength of concrete, the strong influence of mass ratio, slump expansion degree was studied. Through the mean and range analysis of the test results, the results show that the water binder ratio has the greatest influence on the 28d intensity of recycled lightweight aggregate concrete. Secondly, the fly ash content, the recycled aggregate replacement rate and the sand ratio have little influence. For the factors of expansion: the proportion of fly ash = water binder ratio sand >sand rate> recycled aggregate replacement rate. When the content of fly ash is about 30%, the expanded degree of recycled lightweight aggregate concrete is the highest, and the workability of that is better and the strength of concrete with 28d and 56d are the highest. When the content of brickbat is about 40% brick particles, the strength of concrete reaches the highest.

Methodological reporting in qualitative, quantitative, and mixed methods health services research articles.

Science.gov (United States)

Wisdom, Jennifer P; Cavaleri, Mary A; Onwuegbuzie, Anthony J; Green, Carla A

2012-04-01

Methodologically sound mixed methods research can improve our understanding of health services by providing a more comprehensive picture of health services than either method can alone. This study describes the frequency of mixed methods in published health services research and compares the presence of methodological components indicative of rigorous approaches across mixed methods, qualitative, and quantitative articles. All empirical articles (n = 1,651) published between 2003 and 2007 from four top-ranked health services journals. All mixed methods articles (n = 47) and random samples of qualitative and quantitative articles were evaluated to identify reporting of key components indicating rigor for each method, based on accepted standards for evaluating the quality of research reports (e.g., use of p-values in quantitative reports, description of context in qualitative reports, and integration in mixed method reports). We used chi-square tests to evaluate differences between article types for each component. Mixed methods articles comprised 2.85 percent (n = 47) of empirical articles, quantitative articles 90.98 percent (n = 1,502), and qualitative articles 6.18 percent (n = 102). There was a statistically significant difference (χ(2) (1) = 12.20, p = .0005, Cramer's V = 0.09, odds ratio = 1.49 [95% confidence interval = 1,27, 1.74]) in the proportion of quantitative methodological components present in mixed methods compared to quantitative papers (21.94 versus 47.07 percent, respectively) but no statistically significant difference (χ(2) (1) = 0.02, p = .89, Cramer's V = 0.01) in the proportion of qualitative methodological components in mixed methods compared to qualitative papers (21.34 versus 25.47 percent, respectively). Few published health services research articles use mixed methods. The frequency of key methodological components is variable. Suggestions are provided to increase the transparency of mixed methods studies and

Development of a Self-Rated Mixed Methods Skills Assessment: The NIH Mixed Methods Research Training Program for the Health Sciences

Science.gov (United States)

Guetterman, Timothy C.; Creswell, John W.; Wittink, Marsha; Barg, Fran K.; Castro, Felipe G.; Dahlberg, Britt; Watkins, Daphne C.; Deutsch, Charles; Gallo, Joseph J.

2017-01-01

Introduction Demand for training in mixed methods is high, with little research on faculty development or assessment in mixed methods. We describe the development of a Self-Rated Mixed Methods Skills Assessment and provide validity evidence. The instrument taps six research domains: “Research question,” “Design/approach,” “Sampling,” “Data collection,” “Analysis,” and “Dissemination.” Respondents are asked to rate their ability to define or explain concepts of mixed methods under each domain, their ability to apply the concepts to problems, and the extent to which they need to improve. Methods We administered the questionnaire to 145 faculty and students using an internet survey. We analyzed descriptive statistics and performance characteristics of the questionnaire using Cronbach’s alpha to assess reliability and an ANOVA that compared a mixed methods experience index with assessment scores to assess criterion-relatedness. Results Internal consistency reliability was high for the total set of items (.95) and adequate (>=.71) for all but one subscale. Consistent with establishing criterion validity, respondents who had more professional experiences with mixed methods (e.g., published a mixed methods paper) rated themselves as more skilled, which was statistically significant across the research domains. Discussion This Self-Rated Mixed Methods Assessment instrument may be a useful tool to assess skills in mixed methods for training programs. It can be applied widely at the graduate and faculty level. For the learner, assessment may lead to enhanced motivation to learn and training focused on self-identified needs. For faculty, the assessment may improve curriculum and course content planning. PMID:28562495

Pulse Jet Mixing Tests With Noncohesive Solids

Energy Technology Data Exchange (ETDEWEB)

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael K.; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro

2012-02-17

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.

Realism and Pragmatism in a mixed methods study.

Science.gov (United States)

Allmark, Peter; Machaczek, Katarzyna

2018-06-01

A discussion of how adopting a Realist rather than Pragmatist methodology affects the conduct of mixed methods research. Mixed methods approaches are now extensively employed in nursing and other healthcare research. At the same time, realist methodology is increasingly used as philosophical underpinning of research in these areas. However, the standard philosophical underpinning of mixed methods research is Pragmatism, which is generally considered incompatible or at least at odds with Realism. This paper argues that Realism can be used as the basis of mixed methods research and that doing so carries advantages over using Pragmatism. A mixed method study into patient handover reports is used to illustrate how Realism affected its design and how it would have differed had a Pragmatist approach been taken. Discussion Paper. Philosophers Index; Google Scholar. Those undertaking mixed methods research should consider the use of Realist methodology with the addition of some insights from Pragmatism to do with the start and end points of enquiry. Realism is a plausible alternative methodology for those undertaking mixed methods studies. © 2018 John Wiley & Sons Ltd.

Mitigating Wind Induced Noise in Outdoor Microphone Signals Using a Singular Spectral Subspace Method

Directory of Open Access Journals (Sweden)

Omar Eldwaik

2018-01-01

Full Text Available Wind induced noise is one of the major concerns of outdoor acoustic signal acquisition. It affects many field measurement and audio recording scenarios. Filtering such noise is known to be difficult due to its broadband and time varying nature. In this paper, a new method to mitigate wind induced noise in microphone signals is developed. Instead of applying filtering techniques, wind induced noise is statistically separated from wanted signals in a singular spectral subspace. The paper is presented in the context of handling microphone signals acquired outdoor for acoustic sensing and environmental noise monitoring or soundscapes sampling. The method includes two complementary stages, namely decomposition and reconstruction. The first stage decomposes mixed signals in eigen-subspaces, selects and groups the principal components according to their contributions to wind noise and wanted signals in the singular spectrum domain. The second stage reconstructs the signals in the time domain, resulting in the separation of wind noise and wanted signals. Results show that microphone wind noise is separable in the singular spectrum domain evidenced by the weighted correlation. The new method might be generalized to other outdoor sound acquisition applications.

The application of mixed methods designs to trauma research.

Science.gov (United States)

Creswell, John W; Zhang, Wanqing

2009-12-01

Despite the use of quantitative and qualitative data in trauma research and therapy, mixed methods studies in this field have not been analyzed to help researchers designing investigations. This discussion begins by reviewing four core characteristics of mixed methods research in the social and human sciences. Combining these characteristics, the authors focus on four select mixed methods designs that are applicable in trauma research. These designs are defined and their essential elements noted. Applying these designs to trauma research, a search was conducted to locate mixed methods trauma studies. From this search, one sample study was selected, and its characteristics of mixed methods procedures noted. Finally, drawing on other mixed methods designs available, several follow-up mixed methods studies were described for this sample study, enabling trauma researchers to view design options for applying mixed methods research in trauma investigations.

Phase III (full scale) agitated mixing test plan

International Nuclear Information System (INIS)

Ruff, D.T.

1994-01-01

Waste Receiving and Processing Facility Module 2A (WRAP 2A) is the proposed second module of the WRAP facility. This facility will provide the required treatment for contact Handled (CH) Low Level (LL) Mixed Waste (MW) to allow its permanent disposal. Solidification of a portion of this waste using a cement based grout has been selected in order to reduce the toxicity and mobility of the waste in the disposal site. Mixing of the waste with the cement paste and material handling constraints/requirements associated with the mixed material is, therefore, a key process in the overall treatment strategy. This test plan addresses Phase 3, Full Scale Testing. The objectives of these tests are to determine if there are scale-up issues associated with the mixing results obtained in Phase 1 and 2 mixing tests, verify the workability of mixtures resulting from previous formulation development efforts (Waste Immobilization Development [WID]), and provide a baseline for WRAP 2A mixing equipment design. To this end, the following objectives are of particular interest: determine geometric influence of mixing blade at full scale (i.e., size, type, and location: height/offset); determine if similar results in terms of mixing effectiveness and product quality are achievable at this scale; determine if vibration is as effective at this larger scale in fluidizing the mixture and aiding in cleaning the vessel; determine if baffles or sweeping blades are needed to aid in mixing at the larger size and for cleaning the vessel; and determine quality of the poured monolithic product and investigate exotherm and filling influences at this larger size

Mixed Methods and Action Research: similar or different?

OpenAIRE

Wiśniewska, Danuta

2011-01-01

This article attempts to analyse and compare ELT studies grounded solely in mixed methods and ELT action research studies based on a mixed methods approach in order to identify to what degree action research studies combining different methods in a single study comply with the principles of rigorous mixed methods study.

Mixed-methods research in nursing - a critical review.

Science.gov (United States)

Bressan, Valentina; Bagnasco, Annamaria; Aleo, Giuseppe; Timmins, Fiona; Barisone, Michela; Bianchi, Monica; Pellegrini, Ramona; Sasso, Loredana

2017-10-01

To review the use of mixed-methods research in nursing with a particular focus on the extent to which current practice informs nurse researchers. It also aimed to highlight gaps in current knowledge, understanding and reporting of this type of research. Mixed-methods research is becoming increasingly popular among nurses and healthcare professionals. Emergent findings from this type of research are very useful for nurses in practice. The combination of both quantitative and qualitative methods provides a scientific base for practice but also richness from the qualitative enquiry. However, at the same time mixed-methods research is underdeveloped. This study identified mixed-methods research papers and critically evaluated their usefulness for research practice. To support the analysis, we performed a two-stage search using CINAHL to find papers with titles that included the key term 'mixed method'. An analysis of studies that used mixed-methods research revealed some inconsistencies in application and reporting. Attempts to use two distinct research methods in these studies often meant that one or both aspects had limitations. Overall methods were applied in a less rigorous way. This has implications for providing somewhat limited direction for novice researchers. There is also potential for application of evidence in healthcare practice that limited validity. This study highlights current gaps in knowledge, understanding and reporting of mixed-methods research. While these methods are useful to gain insight into clinical problems nurses lack guidance with this type of research. This study revealed that the guidance provided by current mixed-methods research is inconsistent and incomplete and this compounds the lack of available direction. There is an urgent need to develop robust guidelines for using mixed-methods research so that findings may be critically implemented in practice. © 2016 John Wiley & Sons Ltd.

Challenges in Using Mix Methods in Evaluation

OpenAIRE

Stefan COJOCARU

2010-01-01

This article explores the debates between quantitative and qualitative methods in the evaluation process, analyzes the challenges about methodological mix in terms of credibility and validity of data and tools, and the evaluation findings. Beyond the epistemological contradictions, it seems that, in terms of usefulness, the mixing of methods is a practical solution, along with hybrids theories, able to provide information to improve the sufficiency of the program. Mixing methods is also a wa...

What is so new about mixed methods?

Science.gov (United States)

Pelto, Pertti J

2015-06-01

In this article, I dispute claims that mixed methods research emerged only recently in the social sciences. I argue that some anthropologists and sociologists (and others) have used mixed methods in fieldwork for at least 80 years, and there are studies from early in the 20th century that clearly fall within the definition of "mixed methods." I explore some of the history of the mixing of qualitative and quantitative data in earlier ethnographic works and show that in some sectors of social science research, the "emergence" and proliferation of mixed methods were particularly notable around the middle of the 20th century. Furthermore, concerning issues about "paradigms of research" in the social sciences, I identify some of the types of research in which the mixing of QUAL and QUAN approaches was more likely to occur. I suggest that some of the literature about research paradigms has involved a certain amount of "myth-making" in connection with descriptions of qualitative and quantitative research assumptions and styles. © The Author(s) 2015.

A multigrid solution method for mixed hybrid finite elements

Energy Technology Data Exchange (ETDEWEB)

Schmid, W. [Universitaet Augsburg (Germany)

1996-12-31

We consider the multigrid solution of linear equations arising within the discretization of elliptic second order boundary value problems of the form by mixed hybrid finite elements. Using the equivalence of mixed hybrid finite elements and non-conforming nodal finite elements, we construct a multigrid scheme for the corresponding non-conforming finite elements, and, by this equivalence, for the mixed hybrid finite elements, following guidelines from Arbogast/Chen. For a rectangular triangulation of the computational domain, this non-conforming schemes are the so-called nodal finite elements. We explicitly construct prolongation and restriction operators for this type of non-conforming finite elements. We discuss the use of plain multigrid and the multilevel-preconditioned cg-method and compare their efficiency in numerical tests.

Mixed Methods in Biomedical and Health Services Research

Science.gov (United States)

Curry, Leslie A.; Krumholz, Harlan M.; O’Cathain, Alicia; Plano Clark, Vicki L.; Cherlin, Emily; Bradley, Elizabeth H.

2013-01-01

Mixed methods studies, in which qualitative and quantitative methods are combined in a single program of inquiry, can be valuable in biomedical and health services research, where the complementary strengths of each approach can yield greater insight into complex phenomena than either approach alone. Although interest in mixed methods is growing among science funders and investigators, written guidance on how to conduct and assess rigorous mixed methods studies is not readily accessible to the general readership of peer-reviewed biomedical and health services journals. Furthermore, existing guidelines for publishing mixed methods studies are not well known or applied by researchers and journal editors. Accordingly, this paper is intended to serve as a concise, practical resource for readers interested in core principles and practices of mixed methods research. We briefly describe mixed methods approaches and present illustrations from published biomedical and health services literature, including in cardiovascular care, summarize standards for the design and reporting of these studies, and highlight four central considerations for investigators interested in using these methods. PMID:23322807

Generation and coherent detection of QPSK signal using a novel method of digital signal processing

Science.gov (United States)

Zhao, Yuan; Hu, Bingliang; He, Zhen-An; Xie, Wenjia; Gao, Xiaohui

2018-02-01

We demonstrate an optical quadrature phase-shift keying (QPSK) signal transmitter and an optical receiver for demodulating optical QPSK signal with homodyne detection and digital signal processing (DSP). DSP on the homodyne detection scheme is employed without locking the phase of the local oscillator (LO). In this paper, we present an extracting one-dimensional array of down-sampling method for reducing unwanted samples of constellation diagram measurement. Such a novel scheme embodies the following major advantages over the other conventional optical QPSK signal detection methods. First, this homodyne detection scheme does not need strict requirement on LO in comparison with linear optical sampling, such as having a flat spectral density and phase over the spectral support of the source under test. Second, the LabVIEW software is directly used for recovering the QPSK signal constellation without employing complex DSP circuit. Third, this scheme is applicable to multilevel modulation formats such as M-ary PSK and quadrature amplitude modulation (QAM) or higher speed signals by making minor changes.

Campbell's MSV method the neutron-gamma discrimination in mixed field of nuclear reactor

International Nuclear Information System (INIS)

Stankovic, S. J.; Loncar, B.; Avramovic, I.; Osmokrovic, P.

2003-10-01

In this paper it is carried out the analysis some capabilities of Campbell's MSV (Mean Square Value) measuring chain on base the principles derived by Campbell's theorem. Nevertheless, measurements have performed with digitized MSV method and results have compared related to they attained with classic measuring chain, when the mean value of signal from detector output has measured. In our case, detector element was uncompensated ionization chamber for mixed n-gamma fields. Thermal neutron flux, absorbed dose rate, equivalent dose rate and exposure rate in surrounding the reactor vessel of system HERBE, at nuclear reactor RB in 'VINCA' Institute, are determined. The examination of discrimination for gamma relate to neutron component in signal of detector output is performed whereby experimental work and the calculation according to linear theoretical model. The dependencies of changes for variance and mean value output detector signal versus four-decade change of fission reactor power, in range from 10 mW to 22W, are obtained. The advantage of MSV method is confirmed and concluded that the order n-gamma discrimination in MSV signal processing is around fifty times larger than classical measuring method. (author)

Subject-independent emotion recognition based on physiological signals: a three-stage decision method.

Science.gov (United States)

Chen, Jing; Hu, Bin; Wang, Yue; Moore, Philip; Dai, Yongqiang; Feng, Lei; Ding, Zhijie

2017-12-20

Collaboration between humans and computers has become pervasive and ubiquitous, however current computer systems are limited in that they fail to address the emotional component. An accurate understanding of human emotions is necessary for these computers to trigger proper feedback. Among multiple emotional channels, physiological signals are synchronous with emotional responses; therefore, analyzing physiological changes is a recognized way to estimate human emotions. In this paper, a three-stage decision method is proposed to recognize four emotions based on physiological signals in the multi-subject context. Emotion detection is achieved by using a stage-divided strategy in which each stage deals with a fine-grained goal. The decision method consists of three stages. During the training process, the initial stage transforms mixed training subjects to separate groups, thus eliminating the effect of individual differences. The second stage categorizes four emotions into two emotion pools in order to reduce recognition complexity. The third stage trains a classifier based on emotions in each emotion pool. During the testing process, a test case or test trial will be initially classified to a group followed by classification into an emotion pool in the second stage. An emotion will be assigned to the test trial in the final stage. In this paper we consider two different ways of allocating four emotions into two emotion pools. A comparative analysis is also carried out between the proposal and other methods. An average recognition accuracy of 77.57% was achieved on the recognition of four emotions with the best accuracy of 86.67% to recognize the positive and excited emotion. Using differing ways of allocating four emotions into two emotion pools, we found there is a difference in the effectiveness of a classifier on learning each emotion. When compared to other methods, the proposed method demonstrates a significant improvement in recognizing four emotions in the

Mixed Methods Research Prevalence Studies: Field-Specific Studies on the State of the Art of Mixed Methods Research

OpenAIRE

Molina-Azorín, José F.; Fetters, Michael D.

2016-01-01

The Journal of Mixed Methods Research (JMMR) has always welcomed two main kinds of manuscripts: original empirical articles and methodological/theoretical articles (Creswell & Tashakkori, 2007; Fetters & Freshwater, 2015a; Mertens, 2011). Both types of articles must clearly state methodological aims, review mixed methods literature relative to the methodological aim, and advance the field of mixed methods—empirical articles must address integration (Fetters & Freshwater, 2015b). In this edito...

Qualitative and mixed methods in public health

National Research Council Canada - National Science Library

Padgett, Deborah

2012-01-01

"This text has a large emphasis on mixed methods, examples relating to health research, new exercises pertaining to health research, and an introduction on qualitative and mixed methods in public health...

Educational Accountability: A Qualitatively Driven Mixed-Methods Approach

Science.gov (United States)

Hall, Jori N.; Ryan, Katherine E.

2011-01-01

This article discusses the importance of mixed-methods research, in particular the value of qualitatively driven mixed-methods research for quantitatively driven domains like educational accountability. The article demonstrates the merits of qualitative thinking by describing a mixed-methods study that focuses on a middle school's system of…

Design Patterns for Mixed-Method Research in HCI

NARCIS (Netherlands)

Robert Holwerda; Arthur Bennis; Lambert Zaad; René Bakker; Sabine Craenmehr; Stijn Hoppenbrouwers; Dick Lenior; Marjolein Jacobs; Koen van Turnhout; Ralph Niels

2014-01-01

In this paper we discuss mixed-method research in HCI. We report on an empirical literature study of the NordiCHI 2012 proceedings which aimed to uncover and describe common mixed-method approaches, and to identify good practices for mixed-methods research in HCI. We present our results as

Radioactive tracer method as an instrument for testing effectiveness of effluent treatment installations and mixing patterns in natural streams

Energy Technology Data Exchange (ETDEWEB)

Szpilowski, S; Strzelczak, G; Winnicki, R [Institute of Nuclear Research, Warsaw (Poland)

1976-01-01

The radiotracer methods of evaluation of sewage flow rate, testing of effluent treatment plants and mixing patterns in natural streams have been described. Experimental works were carried out for industrial installations and natural streams. As a tracer of liquid phase an aqueous KBr solution labelled with /sup 82/Br have been used. The sediment materials have been labelled with /sup 198/Au in the form of colloidal gold. The results of investigations have been utilized for treatment process analysis and water pollution control.

Reduction of heart sound interference from lung sound signals using empirical mode decomposition technique.

Science.gov (United States)

Mondal, Ashok; Bhattacharya, P S; Saha, Goutam

2011-01-01

During the recording time of lung sound (LS) signals from the chest wall of a subject, there is always heart sound (HS) signal interfering with it. This obscures the features of lung sound signals and creates confusion on pathological states, if any, of the lungs. A novel method based on empirical mode decomposition (EMD) technique is proposed in this paper for reducing the undesired heart sound interference from the desired lung sound signals. In this, the mixed signal is split into several components. Some of these components contain larger proportions of interfering signals like heart sound, environmental noise etc. and are filtered out. Experiments have been conducted on simulated and real-time recorded mixed signals of heart sound and lung sound. The proposed method is found to be superior in terms of time domain, frequency domain, and time-frequency domain representations and also in listening test performed by pulmonologist.

Investigating Learning with an Interactive Tutorial: A Mixed-Methods Strategy

Science.gov (United States)

de Villiers, M. R.; Becker, Daphne

2017-01-01

From the perspective of parallel mixed-methods research, this paper describes interactivity research that employed usability-testing technology to analyse cognitive learning processes; personal learning styles and times; and errors-and-recovery of learners using an interactive e-learning tutorial called "Relations." "Relations"…

Materials and test methods

International Nuclear Information System (INIS)

Kase, M.B.

1985-01-01

The objective of this study was to provide, in cooperation with ORNL and LANL, specimens required for studies to develop organic insulators having the cryogenic neutron irradiation resistance required for MFE systems utilizing superconducting magnetic confinement. To develop test methods and analytical procedures for assessing radiation damage. To stimulate and participate in international cooperation directed toward accomplishing these objectives. The system for producing uniaxially reinforced, 3-4 mm (0.125 in) diameter rod specimens has been refined and validated by production of excellent quality specimens using liquid-mix epoxy resin systems. The methodology is undergoing further modification to permit use of hot-melt epoxy and polyimide resin systems as will be required for the experimental program to be conducted in the NLTNIF reactor at ORNL. Preliminary studies indicate that short beam and torsional shear test methods will be useful in evaluating radiation degradation. Development of these and other applicable test methods are continuing. A cooperative program established with laboratories in Japan and in England has resulted in the production and testing of specimens having an identical configuration

Detection Of Cracks In Composite Materials Using Hybrid Non-Destructive Testing Method Based On Vibro-Thermography And Time-Frequency Analysis Of Ultrasonic Excitation Signal

Directory of Open Access Journals (Sweden)

Prokopowicz Wojciech

2015-09-01

Full Text Available The theme of the publication is to determine the possibility of diagnosing damage in composite materials using vibrio-thermography and frequency analysis and time-frequency of excitation signal. In order to verify the proposed method experiments were performed on a sample of the composite made in the technology of pressing prepregs. Analysis of the recorded signals and the thermograms were performed in MatLab environment. Hybrid non-destructive testing method based on thermogram and appropriate signal processing algorithm clearly showed damage in the sample composite material.

Rheological Method for Alpha Test Evaluation of Developing Superplasticizers’ Performance: Channel Flow Test

Directory of Open Access Journals (Sweden)

Jae Hong Kim

2017-01-01

Full Text Available Advance in high-range water-reducing admixture revolutionizes the workability and constructability of conventional vibrated concrete as well as self-consolidating concrete. Its need from construction fields has increased, and consequently a variety of new-type polycarboxylates, base polymers for the admixture, are being formulated in these days. Synthesizing new polymers needs a quick, but reliable, test to evaluate its performance on concrete. The test is also asked for selecting the best applicable brand of them before a test concrete will be mixed. This paper proposes a “channel flow test” and its usage for the purpose. The proposed procedure for the test includes the mix proportion of a test mortar, the test method, and rheological interpretation of the test results.

The promise of mixed-methods for advancing latino health research.

Science.gov (United States)

Apesoa-Varano, Ester Carolina; Hinton, Ladson

2013-09-01

Mixed-methods research in the social sciences has been conducted for quite some time. More recently, mixed-methods have become popular in health research, with the National Institutes of Health leading the impetus to fund studies that implement such an approach. The public health issues facing us today are great and they range from policy and other macro-level issues, to systems level problems to individuals' health behaviors. For Latinos, who are projected to become the largest minority group bearing a great deal of the burden of social inequality in the U.S., it is important to understand the deeply-rooted nature of these health disparities in order to close the gap in health outcomes. Mixed-methodology thus holds promise for advancing research on Latino heath by tackling health disparities from a variety of standpoints and approaches. The aim of this manuscript is to provide two examples of mixed methods research, each of which addresses a health topic of considerable importance to older Latinos and their families. These two examples will illustrate a) the complementary use of qualitative and quantitative methods to advance health of older Latinos in an area that is important from a public health perspective, and b) the "translation" of findings from observational studies (informed by social science and medicine) to the development and testing of interventions.

Combining the power of stories and the power of numbers: mixed methods research and mixed studies reviews.

Science.gov (United States)

Pluye, Pierre; Hong, Quan Nha

2014-01-01

This article provides an overview of mixed methods research and mixed studies reviews. These two approaches are used to combine the strengths of quantitative and qualitative methods and to compensate for their respective limitations. This article is structured in three main parts. First, the epistemological background for mixed methods will be presented. Afterward, we present the main types of mixed methods research designs and techniques as well as guidance for planning, conducting, and appraising mixed methods research. In the last part, we describe the main types of mixed studies reviews and provide a tool kit and examples. Future research needs to offer guidance for assessing mixed methods research and reporting mixed studies reviews, among other challenges.

Onset Detection in Surface Electromyographic Signals: A Systematic Comparison of Methods

Directory of Open Access Journals (Sweden)

Claus Flachenecker

2001-06-01

Full Text Available Various methods to determine the onset of the electromyographic activity which occurs in response to a stimulus have been discussed in the literature over the last decade. Due to the stochastic characteristic of the surface electromyogram (SEMG, onset detection is a challenging task, especially in weak SEMG responses. The performance of the onset detection methods were tested, mostly by comparing their automated onset estimations to the manually determined onsets found by well-trained SEMG examiners. But a systematic comparison between methods, which reveals the benefits and the drawbacks of each method compared to the other ones and shows the specific dependence of the detection accuracy on signal parameters, is still lacking. In this paper, several classical threshold-based approaches as well as some statistically optimized algorithms were tested on large samples of simulated SEMG data with well-known signal parameters. Rating between methods is performed by comparing their performance to that of a statistically optimal maximum likelihood estimator which serves as reference method. In addition, performance was evaluated on real SEMG data obtained in a reaction time experiment. Results indicate that detection behavior strongly depends on SEMG parameters, such as onset rise time, signal-to-noise ratio or background activity level. It is shown that some of the threshold-based signal-power-estimation procedures are very sensitive to signal parameters, whereas statistically optimized algorithms are generally more robust.

A mixed-methods exploration of an environment for learning computer programming

Directory of Open Access Journals (Sweden)

Richard Mather

2015-08-01

Full Text Available A mixed-methods approach is evaluated for exploring collaborative behaviour, acceptance and progress surrounding an interactive technology for learning computer programming. A review of literature reveals a compelling case for using mixed-methods approaches when evaluating technology-enhanced-learning environments. Here, ethnographic approaches used for the requirements engineering of computing systems are combined with questionnaire-based feedback and skill tests. These are applied to the ‘Ceebot’ animated 3D learning environment. Video analysis with workplace observation allowed detailed inspection of problem solving and tacit behaviours. Questionnaires and knowledge tests provided broad sample coverage with insights into subject understanding and overall response to the learning environment. Although relatively low scores in programming tests seemingly contradicted the perception that Ceebot had enhanced understanding of programming, this perception was nevertheless found to be correlated with greater test performance. Video analysis corroborated findings that the learning environment and Ceebot animations were engaging and encouraged constructive collaborative behaviours. Ethnographic observations clearly captured Ceebot's value in providing visual cues for problem-solving discussions and for progress through sharing discoveries. Notably, performance in tests was most highly correlated with greater programming practice (p≤0.01. It was apparent that although students had appropriated technology for collaborative working and benefitted from visual and tacit cues provided by Ceebot, they had not necessarily deeply learned the lessons intended. The key value of the ‘mixed-methods’ approach was that ethnographic observations captured the authenticity of learning behaviours, and thereby strengthened confidence in the interpretation of questionnaire and test findings.

A mixed signal multi-chip module with high speed serial output links for the ATLAS Level-1 trigger

CERN Document Server

Pfeiffer, U

2000-01-01

We have built and tested a mixed signal multi-chip module (MCM) to be used in the Level-1 Pre-Processor system for the Calorimeter Trigger of the ATLAS experiment at CERN. The MCM performs high speed digital signal processing on four analogue input signals. Results are transmitted serially at a serial data rate of 800 MBd. Nine chips of different technologies are mounted on a four layer Cu substrate. ADC converters and serialiser chips are the major consumers of electrical power on the MCM, which amounts to 9 W for all dies. Special cut-out areas are used to dissipate heat directly to the copper substrate. In this paper we report on design criteria, chosen MCM technology for substrate and die mounting, experiences with the MCM operation and measurement results. (4 refs).

ADDRESSING RESEARCH DESIGN PROBLEM IN MIXED METHODS RESEARCH

OpenAIRE

Hamed ALAVI; Patrycja HĄBEK

2016-01-01

Alongside other disciplines in social sciences, management researchers use mixed methods research more and more in conduct of their scientific investigations. Mixed methods approach can also be used in the field of production engineering. In comparison with traditional quantitative and qualitative research methods, reasons behind increasing popularity of mixed research method in management science can be traced in different factors. First of all, any particular discipline in management can be...

Mixed signal custom integrated circuit development for physics instrumentation

International Nuclear Information System (INIS)

Britton, C.L. Jr.; Bryan, W.L.; Emery, M.S.

1998-01-01

The Monolithic Systems Development Group at the Oak Ridge National Laboratory has been greatly involved in custom mixed-mode integrated circuit development for the PHENIX detector at the Relativistic Heavy Ion collider (RHIC) at Brookhaven National Laboratory and position-sensitive germanium spectrometer front-ends for the Naval Research Laboratory (NRL). This paper will outline the work done for both PHENIX and the Naval Research Laboratory in the area of full-custom, mixed-signal CMOS integrated electronics. This paper presents the architectures chosen for the various PHENIX detectors which include position-sensitive silicon, capacitive pixel, and phototube detectors, and performance results for the subsystems as well as a system description of the NRL germanium strip system and its performance. The performance of the custom preamplifiers, discriminators, analog memories, analog-digital converters, and control circuitry for all systems will be presented

Mixed signal custom integrated circuit development for physics instrumentation

Energy Technology Data Exchange (ETDEWEB)

Britton, C.L. Jr.; Bryan, W.L.; Emery, M.S. [and others

1998-10-01

The Monolithic Systems Development Group at the Oak Ridge National Laboratory has been greatly involved in custom mixed-mode integrated circuit development for the PHENIX detector at the Relativistic Heavy Ion collider (RHIC) at Brookhaven National Laboratory and position-sensitive germanium spectrometer front-ends for the Naval Research Laboratory (NRL). This paper will outline the work done for both PHENIX and the Naval Research Laboratory in the area of full-custom, mixed-signal CMOS integrated electronics. This paper presents the architectures chosen for the various PHENIX detectors which include position-sensitive silicon, capacitive pixel, and phototube detectors, and performance results for the subsystems as well as a system description of the NRL germanium strip system and its performance. The performance of the custom preamplifiers, discriminators, analog memories, analog-digital converters, and control circuitry for all systems will be presented.

Developing a bone mineral density test result letter to send to patients: a mixed-methods study

Directory of Open Access Journals (Sweden)

Edmonds SW

2014-06-01

Full Text Available Stephanie W Edmonds,1,2 Samantha L Solimeo,3 Xin Lu,1 Douglas W Roblin,4,8 Kenneth G Saag,5 Peter Cram6,7 1Department of Internal Medicine, 2College of Nursing, University of Iowa, Iowa City, IA, USA; 3Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, IA, USA; 4Kaiser Permanente of Atlanta, Atlanta, GA, USA; 5Department of Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA; 6Faculty of Medicine, University of Toronto, Toronto, ON, Canada; 7University Health Network and Mount Sinai Hospital, Toronto, ON, Canada; 8School of Public Health, Georgia State University, Atlanta, GA, USA Purpose: To use a mixed-methods approach to develop a letter that can be used to notify patients of their bone mineral density (BMD results by mail that may activate patients in their bone-related health care. Patients and methods: A multidisciplinary team developed three versions of a letter for reporting BMD results to patients. Trained interviewers presented these letters in a random order to a convenience sample of adults, aged 50 years and older, at two different health care systems. We conducted structured interviews to examine the respondents’ preferences and comprehension among the various letters. Results: A total of 142 participants completed the interview. A majority of the participants were female (64.1% and white (76.1%. A plurality of the participants identified a specific version of the three letters as both their preferred version (45.2%; P<0.001 and as the easiest to understand (44.6%; P<0.01. A majority of participants preferred that the letters include specific next steps for improving their bone health. Conclusion: Using a mixed-methods approach, we were able to develop and optimize a printed letter for communicating a complex test result (BMD to patients. Our results may offer guidance to clinicians, administrators, and researchers who are

Approaches to Mixed Methods Dissemination and Implementation Research: Methods, Strengths, Caveats, and Opportunities.

Science.gov (United States)

Green, Carla A; Duan, Naihua; Gibbons, Robert D; Hoagwood, Kimberly E; Palinkas, Lawrence A; Wisdom, Jennifer P

2015-09-01

Limited translation of research into practice has prompted study of diffusion and implementation, and development of effective methods of encouraging adoption, dissemination and implementation. Mixed methods techniques offer approaches for assessing and addressing processes affecting implementation of evidence-based interventions. We describe common mixed methods approaches used in dissemination and implementation research, discuss strengths and limitations of mixed methods approaches to data collection, and suggest promising methods not yet widely used in implementation research. We review qualitative, quantitative, and hybrid approaches to mixed methods dissemination and implementation studies, and describe methods for integrating multiple methods to increase depth of understanding while improving reliability and validity of findings.

Signal processing for non-destructive testing of railway tracks

Science.gov (United States)

Heckel, Thomas; Casperson, Ralf; Rühe, Sven; Mook, Gerhard

2018-04-01

Increased speed, heavier loads, altered material and modern drive systems result in an increasing number of rail flaws. The appearance of these flaws also changes continually due to the rapid change in damage mechanisms of modern rolling stock. Hence, interpretation has become difficult when evaluating non-destructive rail testing results. Due to the changed interplay between detection methods and flaws, the recorded signals may result in unclassified types of rail flaws. Methods for automatic rail inspection (according to defect detection and classification) undergo continual development. Signal processing is a key technology to master the challenge of classification and maintain resolution and detection quality, independent of operation speed. The basic ideas of signal processing, based on the Glassy-Rail-Diagram for classification purposes, are presented herein. Examples for the detection of damages caused by rolling contact fatigue also are given, and synergetic effects of combined evaluation of diverse inspection methods are shown.

Effect of mixing method on the mixing degree during the preparation of triturations.

Science.gov (United States)

Nakamura, Hitoshi; Yanagihara, Yoshitsugu; Sekiguchi, Hiroko; Komada, Fusao; Kawabata, Haruno; Ohtani, Michiteru; Saitoh, Yukiya; Kariya, Satoru; Suzuki, Hiroshi; Uchino, Katsuyoshi; Iga, Tatsuji

2004-03-01

By using lactose colored with erythrocin, we investigated the effects of mixing methods on mixing degree during the preparation of trituration with a mortar and pestle. The extent of powder dilution was set to 4 to 64 fold in the experiments. We compared the results obtained by using two methods: (1) one-step mixing of powders after addition of diluents and (2) gradual mixing of powders after addition of diluents. As diluents, we used crystallized lactose and powdered lactose for the preparation of trituration. In the preparation of 64-fold trituration, an excellent degree of mixing was obtained, with CV values of less than 6.08%, for both preparation methods and for the two kinds of diluents. The mixing of two kinds of powders whose distributions of particle sizes were similar resulted in much better degree of mixing, with CV values of less than 3.0%. However, the concentration of principal agents in 64-fold trituration was reduced by 20% due to the adsorption of dye to the apparatus. Under conditions in which a much higher dilution rate and/or much better degree of dilution was required, it must be necessary to dilute powders with considering their physicality and to determine the concentrations of principal agents after the mixing.

Collaboration Patterns as a Function of Article Genre among Mixed Researchers: A Mixed Methods Bibliometric Study

Science.gov (United States)

Jordan, John; Wachsmann, Melanie; Hoisington, Susan; Gonzalez, Vanessa; Valle, Rachel; Lambert, Jarod; Aleisa, Majed; Wilcox, Rachael; Benge, Cindy L.; Onwuegbuzie, Anthony J.

2017-01-01

Surprisingly, scant information exists regarding the collaboration patterns of mixed methods researchers. Thus, the purpose of this mixed methods bibliometric study was to examine (a) the distribution of the number of co-authors in articles published in the flagship mixed methods research journal (i.e., "Journal of Mixed Methods…

Hybrid electrokinetic method applied to mix contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Mansour, H.; Maria, E. [Dept. of Building Civil and Environmental Engineering, Concordia Univ., Montreal (Canada)

2001-07-01

Several industrials and municipal areas in North America are contaminated with heavy metals and petroleum products. This mix contamination presents a particularly difficult task for remediation when is exposed in clayey soil. The objective of this research was to find a method to cleanup mix contaminated clayey soils. Finally, a multifunctional hybrid electrokinetic method was investigated. Clayey soil was contaminated with lead and nickel (heavy metals) at the level of 1000 ppm and phenanthrene (PAH) of 600 ppm. Electrokinetic surfactant supply system was applied to mobilize, transport and removal of phenanthrene. A chelation agent (EDTA) was also electrokinetically supplied to mobilize heavy metals. The studies were performed on 8 lab scale electrokinetic cells. The mix contaminated clayey soil was subjected to DC total voltage gradient of 0.3 V/cm. Supplied liquids (surfactant and EDTA) were introduced in different periods of time (22 days, 42 days) in order to optimize the most excessive removal of contaminants. The ph, electrical parameters, volume supplied, and volume discharged was monitored continuously during each experiment. At the end of these tests soil and cathalyte were subjected to physico-chemical analysis. The paper discusses results of experiments including the optimal energy use, removal efficiency of phenanthrene, as well, transport and removal of heavy metals. The results of this study can be applied for in-situ hybrid electrokinetic technology to remediate clayey sites contaminated with petroleum product mixed with heavy metals (e.g. manufacture Gas Plant Sites). (orig.)

A mixed-methods approach to systematic reviews.

Science.gov (United States)

Pearson, Alan; White, Heath; Bath-Hextall, Fiona; Salmond, Susan; Apostolo, Joao; Kirkpatrick, Pamela

2015-09-01

There are an increasing number of published single-method systematic reviews that focus on different types of evidence related to a particular topic. As policy makers and practitioners seek clear directions for decision-making from systematic reviews, it is likely that it will be increasingly difficult for them to identify 'what to do' if they are required to find and understand a plethora of syntheses related to a particular topic.Mixed-methods systematic reviews are designed to address this issue and have the potential to produce systematic reviews of direct relevance to policy makers and practitioners.On the basis of the recommendations of the Joanna Briggs Institute International Mixed Methods Reviews Methodology Group in 2012, the Institute adopted a segregated approach to mixed-methods synthesis as described by Sandelowski et al., which consists of separate syntheses of each component method of the review. Joanna Briggs Institute's mixed-methods synthesis of the findings of the separate syntheses uses a Bayesian approach to translate the findings of the initial quantitative synthesis into qualitative themes and pooling these with the findings of the initial qualitative synthesis.

Mixed Methods in Biomedical and Health Services Research

OpenAIRE

Curry, Leslie A.; Krumholz, Harlan M.; O’Cathain, Alicia; Plano Clark, Vicki L.; Cherlin, Emily; Bradley, Elizabeth H.

2013-01-01

Mixed methods studies, in which qualitative and quantitative methods are combined in a single program of inquiry, can be valuable in biomedical and health services research, where the complementary strengths of each approach can yield greater insight into complex phenomena than either approach alone. Although interest in mixed methods is growing among science funders and investigators, written guidance on how to conduct and assess rigorous mixed methods studies is not readily accessible to th...

Compatible-strain mixed finite element methods for incompressible nonlinear elasticity

Science.gov (United States)

Faghih Shojaei, Mostafa; Yavari, Arash

2018-05-01

We introduce a new family of mixed finite elements for incompressible nonlinear elasticity - compatible-strain mixed finite element methods (CSFEMs). Based on a Hu-Washizu-type functional, we write a four-field mixed formulation with the displacement, the displacement gradient, the first Piola-Kirchhoff stress, and a pressure-like field as the four independent unknowns. Using the Hilbert complexes of nonlinear elasticity, which describe the kinematics and the kinetics of motion, we identify the solution spaces of the independent unknown fields. In particular, we define the displacement in H1, the displacement gradient in H (curl), the stress in H (div), and the pressure field in L2. The test spaces of the mixed formulations are chosen to be the same as the corresponding solution spaces. Next, in a conforming setting, we approximate the solution and the test spaces with some piecewise polynomial subspaces of them. Among these approximation spaces are the tensorial analogues of the Nédélec and Raviart-Thomas finite element spaces of vector fields. This approach results in compatible-strain mixed finite element methods that satisfy both the Hadamard compatibility condition and the continuity of traction at the discrete level independently of the refinement level of the mesh. By considering several numerical examples, we demonstrate that CSFEMs have a good performance for bending problems and for bodies with complex geometries. CSFEMs are capable of capturing very large strains and accurately approximating stress and pressure fields. Using CSFEMs, we do not observe any numerical artifacts, e.g., checkerboarding of pressure, hourglass instability, or locking in our numerical examples. Moreover, CSFEMs provide an efficient framework for modeling heterogeneous solids.

Breaking from binaries - using a sequential mixed methods design.

Science.gov (United States)

Larkin, Patricia Mary; Begley, Cecily Marion; Devane, Declan

2014-03-01

To outline the traditional worldviews of healthcare research and discuss the benefits and challenges of using mixed methods approaches in contributing to the development of nursing and midwifery knowledge. There has been much debate about the contribution of mixed methods research to nursing and midwifery knowledge in recent years. A sequential exploratory design is used as an exemplar of a mixed methods approach. The study discussed used a combination of focus-group interviews and a quantitative instrument to obtain a fuller understanding of women's experiences of childbirth. In the mixed methods study example, qualitative data were analysed using thematic analysis and quantitative data using regression analysis. Polarised debates about the veracity, philosophical integrity and motivation for conducting mixed methods research have largely abated. A mixed methods approach can contribute to a deeper, more contextual understanding of a variety of subjects and experiences; as a result, it furthers knowledge that can be used in clinical practice. The purpose of the research study should be the main instigator when choosing from an array of mixed methods research designs. Mixed methods research offers a variety of models that can augment investigative capabilities and provide richer data than can a discrete method alone. This paper offers an example of an exploratory, sequential approach to investigating women's childbirth experiences. A clear framework for the conduct and integration of the different phases of the mixed methods research process is provided. This approach can be used by practitioners and policy makers to improve practice.

Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade mixed oxides ((U, Pu)O2)

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade mixed oxides, (U, Pu)O2, powders and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Uranium in the Presence of Pu by Potentiometric Titration Plutonium by Controlled-Potential Coulometry Plutonium by Amperometric Titration with Iron (II) Nitrogen by Distillation Spectrophotometry Using Nessler Reagent 7 to 14 Carbon (Total) by Direct Combustion-Thermal Conductivity 15 to 26 Total Chlorine and Fluorine by Pyrohydrolysis 27 to 34 Sulfur by Distillation-Spectrophotometry 35 to 43 Moisture by the Coulometric, Electrolytic Moisture Analyzer 44 to 51 Isotopic Composition by Mass Spectrometry Rare Earths by Copper Spark Spectroscopy 52 to 59 Trace Impurities by Carrier Distillation Spectroscopy 60 to 69 Impurities by Spark-Source Mass Spectrography 70 to 76 Total Gas in Reactor-Grade Mixed Dioxide P...

Wavelet modeling of signals for non-destructive testing of concretes

International Nuclear Information System (INIS)

Shao, Zhixue; Shi, Lihua; Cai, Jian

2011-01-01

In a non-destructive test of concrete structures, ultrasonic pulses are commonly used to detect damage or embedded objects from their reflections. A wavelet modeling method is proposed here to identify the main reflections and to remove the interferences in the detected ultrasonic waves. This method assumes that if the structure is stimulated by a wavelet function with good time–frequency localization ability, the detected signal is a combination of time-delayed and amplitude-attenuated wavelets. Therefore, modeling of the detected signal by wavelets can give a straightforward and simple model of the original signal. The central time and amplitude of each wavelet represent the position and amplitude of the reflections in the detected structure. A signal processing method is also proposed to estimate the structure response to wavelet excitation from its response to a high-voltage pulse with a sharp leading edge. A signal generation card with a compact peripheral component interconnect extension for instrumentation interface is designed to produce this high-voltage pulse. The proposed method is applied to synthesized aperture focusing technology of concrete specimens and the image results are provided

A robust multi-frequency mixing algorithm for suppression of rivet signal in GMR inspection of riveted structures

Science.gov (United States)

Safdernejad, Morteza S.; Karpenko, Oleksii; Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

2016-02-01

The advent of Giant Magneto-Resistive (GMR) technology permits development of novel highly sensitive array probes for Eddy Current (EC) inspection of multi-layer riveted structures. Multi-frequency GMR measurements with different EC pene-tration depths show promise for detection of bottom layer notches at fastener sites. However, the distortion of the induced magnetic field due to flaws is dominated by the strong fastener signal, which makes defect detection and classification a challenging prob-lem. This issue is more pronounced for ferromagnetic fasteners that concentrate most of the magnetic flux. In the present work, a novel multi-frequency mixing algorithm is proposed to suppress rivet signal response and enhance defect detection capability of the GMR array probe. The algorithm is baseline-free and does not require any assumptions about the sample geometry being inspected. Fastener signal suppression is based upon the random sample consensus (RANSAC) method, which iteratively estimates parameters of a mathematical model from a set of observed data with outliers. Bottom layer defects at fastener site are simulated as EDM notches of different length. Performance of the proposed multi-frequency mixing approach is evaluated on finite element data and experimental GMR measurements obtained with unidirectional planar current excitation. Initial results are promising demonstrating the feasibility of the approach.

Mixed methods research for TESOL

CERN Document Server

Brown, James; Farr, Fiona

2014-01-01

Defining and discussing the relevance of theoretical and practical issues involved in mixed methods research. Covering the basics of research methodology, this textbook shows you how to choose and combine quantitative and qualitative research methods to b

College Students; Justification for Digital Piracy: A Mixed Methods Study

Science.gov (United States)

Yu, Szde

2012-01-01

A mixed methods project was devoted to understanding college students' justification for digital piracy. The project consisted of two studies, a qualitative one and a quantitative one. Qualitative interviews were conducted to identify main themes in students' justification for digital piracy, and then the findings were tested in a quantitative…

Optical mixing of microwave signals in a nonlinear semiconductor laser amplifier modulator.

Science.gov (United States)

Capmany, José; Sales, Salvador; Pastor, Daniel; Ortega, Beatriz

2002-02-11

In this paper we propose and evaluate the optical mixing of RF signals by means of exploiting the nonlinearity of a SLA modulator. The results show the potential for devices with low conversion losses (and even gain) and polarization insensitivity and reduced insertion losses.

Detection test of wireless network signal strength and GPS positioning signal in underground pipeline

Science.gov (United States)

Li, Li; Zhang, Yunwei; Chen, Ling

2018-03-01

In order to solve the problem of selecting positioning technology for inspection robot in underground pipeline environment, the wireless network signal strength and GPS positioning signal testing are carried out in the actual underground pipeline environment. Firstly, the strength variation of the 3G wireless network signal and Wi-Fi wireless signal provided by China Telecom and China Unicom ground base stations are tested, and the attenuation law of these wireless signals along the pipeline is analyzed quantitatively and described. Then, the receiving data of the GPS satellite signal in the pipeline are tested, and the attenuation of GPS satellite signal under underground pipeline is analyzed. The testing results may be reference for other related research which need to consider positioning in pipeline.

Mixed methods in psychotherapy research: A review of method(ology) integration in psychotherapy science.

Science.gov (United States)

Bartholomew, Theodore T; Lockard, Allison J

2018-06-13

Mixed methods can foster depth and breadth in psychological research. However, its use remains in development in psychotherapy research. Our purpose was to review the use of mixed methods in psychotherapy research. Thirty-one studies were identified via the PRISMA systematic review method. Using Creswell & Plano Clark's typologies to identify design characteristics, we assessed each study for rigor and how each used mixed methods. Key features of mixed methods designs and these common patterns were identified: (a) integration of clients' perceptions via mixing; (b) understanding group psychotherapy; (c) integrating methods with cases and small samples; (d) analyzing clinical data as qualitative data; and (e) exploring cultural identities in psychotherapy through mixed methods. The review is discussed with respect to the value of integrating multiple data in single studies to enhance psychotherapy research. © 2018 Wiley Periodicals, Inc.

Are partners of HIV-infected people being tested for HIV? A mixed-methods research from Gujarat, India.

Science.gov (United States)

Selvaraj, K; Kumar, A M V; Chawla, S; Shringarpure, K S; Thekkur, P; Palanivel, C; Verma, P B; Shah, A N; Pandya, K N; Roy, G; Singh, Z; Rewari, B B; Dongre, A R

2017-03-21

Setting: Four selected antiretroviral therapy (ART) centres of Gujarat State, India, which accounts for 8% of the human immunodeficiency virus (HIV) burden in India. Objectives: 1) To assess the proportion of people living with HIV (PLHIV) whose partners were not tested for HIV; 2) to assess sociodemographic and clinical characteristics of index cases associated with partner testing; and 3) to understand perceived facilitators and barriers to partner testing and make suggestions on how to improve testing from the perspective of the health-care provider. Design: A mixed-method design with a quantitative phase that involved reviewing the programme records of married PLHIV enrolled during 2011-2015, followed by a qualitative phase of key informant interviews. Results: Of 3884 married PLHIV, 1279 (33%) did not have their partners tested for HIV. Factors including index cases being male, illiterate, aged >25 years, belonging to key populations, substance use and being in advanced clinical stages were more likely to be associated with partner non-testing. Non-disclosure of HIV status (due to fear of marital discord) and lack of awareness and risk perception were the key barriers to testing. Conclusion: One third of PLHIV did not have their partners tested for HIV. Several factors were identified as being associated with the non-testing of partners, and solutions were explored that need to be implemented urgently if we are to achieve the 90-90-90 targets and end HIV.

Balanced detection for self-mixing interferometry.

Science.gov (United States)

Li, Kun; Cavedo, Federico; Pesatori, Alessandro; Zhao, Changming; Norgia, Michele

2017-01-15

We propose a new detection scheme for self-mixing interferometry using two photodiodes for implementing a differential acquisition. The method is based on the phase opposition of the self-mixing signal measured between the two laser diode facet outputs. The subtraction of the two outputs implements a sort of balanced detection that improves the signal quality, and allows canceling of unwanted signals due to laser modulation and disturbances on laser supply and transimpedance amplifier. Experimental results demonstrate the benefits of differential acquisition in a system for both absolute distance and displacement-vibration measurement. This Letter provides guidance for the design of self-mixing interferometers using balanced detection.

A new method research of monitoring low concentration NO and SO2 mixed gas

Science.gov (United States)

Bo, Peng; Gao, Chao; Guo, Yongcai; Chen, Fang

2018-01-01

In order to reduce the pollution of the environment, China has implemented a new ultra-low emission control regulations for polluting gas, requiring new coal-fired power plant emissions SO2 less than 30ppm, NO less than 75ppm, NO2 less than 50ppm, Monitoring low concentration of NO and SO2 mixed gases , DOAS technology facing new challenges, SO2 absorb significantly weaken at the original absorption peak, what more the SNR is very low, it is difficult to extract the characteristic signal, and thus cannot obtain its concentration. So it cannot separate the signal of NO from the mixed gas at the wavelength of 200 230nm through the law of spectral superposition, it cannot calculate the concentration of NO. The classical DOAS technology cannot meet the needs of monitoring. In this paper, we found another absorption spectrum segment of SO2, the SNR is 10 times higher than before, Will not be affected by NO, can calculate the concentration of SO2 accurately, A new method of segmentation and demagnetization separation technology of spectral signals is proposed, which achieves the monitoring the low concentration mixed gas accurately. This function cannot be achieved by the classical DOAS. Detection limit of this method is 0.1ppm per meter which is higher than before, The relative error below 5% when the concentration between 0 5ppm, the concentration of NO between 6 75ppm and SO2 between 6 30ppm the relative error below 1.5%, it has made a great breakthrough In the low concentration of NO and SO2 monitoring. It has great scientific significance and reference value for the development of coal-fired power plant emission control, atmospheric environmental monitoring and high-precision on-line instrumentation.

Mixing Methods in Assessing Coaches' Decision Making

Science.gov (United States)

Vergeer, Ineke; Lyle, John

2007-01-01

Mixing methods has recently achieved respectability as an appropriate approach to research design, offering a variety of advantages (Tashakkori & Teddlie, 2003). The purpose of this paper is to outline and evaluate a mixed methods approach within the domain of coaches' decision making. Illustrated with data from a policy-capturing study on…

FPGAs and wavelets on circuit testing based on current signal measurements

International Nuclear Information System (INIS)

Pouros, Sotirios; Vassios, Vassilios; Manolakis, Dimitrios; Bamnios, Georgios; Papakostas, Dimitrios K.; Hatzopoulos, Alkis A.; Hristov, Valentin

2015-01-01

The research team designed and implemented a prototype testing system using FPGAs, where test methods for analog and digital (mixed) electronics using wavelets can be incorporated. The prototype has been evaluated and the results are promising. Moreover, the usability and verification of the system’s functionality are presented. The current sensing unit is described in detail. The new automated fault testing system incorporates reconfigurability and parallel processing capabilities.

21 CFR 882.1430 - Electroencephalograph test signal generator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electroencephalograph test signal generator. 882.1430 Section 882.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is a...

Testing a Preliminary Live with Love Conceptual Framework for cancer couple dyads: A mixed-methods study.

Science.gov (United States)

Li, Qiuping; Xu, Yinghua; Zhou, Huiya; Loke, Alice Yuen

2015-12-01

The purpose of this study was to test the previous proposed Preliminary Live with Love Conceptual Framework (P-LLCF) that focuses on spousal caregiver-patient couples in their journey of coping with cancer as dyads. A mixed-methods study that included qualitative and quantitative approaches was conducted. Methods of concept and theory analysis, and structural equation modeling (SEM) were applied in testing the P-LLCF. In the qualitative approach in testing the concepts included in the P-LLCF, a comparison was made between the P-LLCF with a preliminary conceptual framework derived from focus group interviews among Chinese couples' coping with cancer. The comparison showed that the concepts identified in the P-LLCF are relevant to the phenomenon under scrutiny, and attributes of the concepts are consistent with those identified among Chinese cancer couple dyads. In the quantitative study, 117 cancer couples were recruited. The findings showed that inter-relationships exist among the components included in the P-LLCF: event situation, dyadic mediators, dyadic appraisal, dyadic coping, and dyadic outcomes. In that the event situation will impact the dyadic outcomes directly or indirectly through Dyadic Mediators. The dyadic mediators, dyadic appraisal, and dyadic coping are interrelated and work together to benefit the dyadic outcomes. This study provides evidence that supports the interlinked components and the relationship included in the P-LLCF. The findings of this study are important in that they provide healthcare professionals with guidance and directions according to the P-LLCF on how to plan supportive programs for couples coping with cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a Self-Rated Mixed Methods Skills Assessment: The National Institutes of Health Mixed Methods Research Training Program for the Health Sciences.

Science.gov (United States)

Guetterman, Timothy C; Creswell, John W; Wittink, Marsha; Barg, Fran K; Castro, Felipe G; Dahlberg, Britt; Watkins, Daphne C; Deutsch, Charles; Gallo, Joseph J

2017-01-01

Demand for training in mixed methods is high, with little research on faculty development or assessment in mixed methods. We describe the development of a self-rated mixed methods skills assessment and provide validity evidence. The instrument taps six research domains: "Research question," "Design/approach," "Sampling," "Data collection," "Analysis," and "Dissemination." Respondents are asked to rate their ability to define or explain concepts of mixed methods under each domain, their ability to apply the concepts to problems, and the extent to which they need to improve. We administered the questionnaire to 145 faculty and students using an internet survey. We analyzed descriptive statistics and performance characteristics of the questionnaire using the Cronbach alpha to assess reliability and an analysis of variance that compared a mixed methods experience index with assessment scores to assess criterion relatedness. Internal consistency reliability was high for the total set of items (0.95) and adequate (≥0.71) for all but one subscale. Consistent with establishing criterion validity, respondents who had more professional experiences with mixed methods (eg, published a mixed methods article) rated themselves as more skilled, which was statistically significant across the research domains. This self-rated mixed methods assessment instrument may be a useful tool to assess skills in mixed methods for training programs. It can be applied widely at the graduate and faculty level. For the learner, assessment may lead to enhanced motivation to learn and training focused on self-identified needs. For faculty, the assessment may improve curriculum and course content planning.

A Mixed Methods Sampling Methodology for a Multisite Case Study

Science.gov (United States)

Sharp, Julia L.; Mobley, Catherine; Hammond, Cathy; Withington, Cairen; Drew, Sam; Stringfield, Sam; Stipanovic, Natalie

2012-01-01

The flexibility of mixed methods research strategies makes such approaches especially suitable for multisite case studies. Yet the utilization of mixed methods to select sites for these studies is rarely reported. The authors describe their pragmatic mixed methods approach to select a sample for their multisite mixed methods case study of a…

Three-dimensional image signals: processing methods

Science.gov (United States)

Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

2010-11-01

Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

Hemodynamic signals of mixed messages during a social exchange.

Science.gov (United States)

Zucker, Nancy L; Green, Steven; Morris, James P; Kragel, Philip; Pelphrey, Kevin A; Bulik, Cynthia M; LaBar, Kevin S

2011-06-22

This study used functional magnetic resonance imaging to characterize hemodynamic activation patterns recruited when the participants viewed mixed social communicative messages during a common interpersonal exchange. Mixed messages were defined as conflicting sequences of biological motion and facial affect signals that are unexpected within a particular social context (e.g. observing the reception of a gift). Across four social vignettes, valenced facial expressions were crossed with rejecting and accepting gestures in a virtual avatar responding to presentation of a gift from the participant. The results indicate that conflicting facial affect and gesture activated superior temporal sulcus, a region implicated in expectancy violations, as well as inferior frontal gyrus and putamen. Scenarios conveying rejection differentially activated the insula and putamen, regions implicated in embodied cognition, and motivated learning, as well as frontoparietal cortex. Characterizing how meaning is inferred from integration of conflicting nonverbal communicative cues is essential to understand nuances and complexities of human exchange.

A hybrid Constraint Programming/Mixed Integer Programming framework for the preventive signaling maintenance crew scheduling problem

DEFF Research Database (Denmark)

Pour, Shahrzad M.; Drake, John H.; Ejlertsen, Lena Secher

2017-01-01

A railway signaling system is a complex and interdependent system which should ensure the safe operation of trains. We introduce and address a mixed integer optimisation model for the preventive signal maintenance crew scheduling problem in the Danish railway system. The problem contains many...... to feed as ‘warm start’ solutions to a Mixed Integer Programming (MIP) solver for further optimisation. We apply the CP/MIP framework to a section of the Danish rail network and benchmark our results against both direct application of a MIP solver and modelling the problem as a Constraint Optimisation...

Mixing Languages during Learning? Testing the One Subject—One Language Rule

Science.gov (United States)

2015-01-01

In bilingual communities, mixing languages is avoided in formal schooling: even if two languages are used on a daily basis for teaching, only one language is used to teach each given academic subject. This tenet known as the one subject-one language rule avoids mixing languages in formal schooling because it may hinder learning. The aim of this study was to test the scientific ground of this assumption by investigating the consequences of acquiring new concepts using a method in which two languages are mixed as compared to a purely monolingual method. Native balanced bilingual speakers of Basque and Spanish—adults (Experiment 1) and children (Experiment 2)—learnt new concepts by associating two different features to novel objects. Half of the participants completed the learning process in a multilingual context (one feature was described in Basque and the other one in Spanish); while the other half completed the learning phase in a purely monolingual context (both features were described in Spanish). Different measures of learning were taken, as well as direct and indirect indicators of concept consolidation. We found no evidence in favor of the non-mixing method when comparing the results of two groups in either experiment, and thus failed to give scientific support for the educational premise of the one subject—one language rule. PMID:26107624

Mixing Languages during Learning? Testing the One Subject-One Language Rule.

Directory of Open Access Journals (Sweden)

Eneko Antón

Full Text Available In bilingual communities, mixing languages is avoided in formal schooling: even if two languages are used on a daily basis for teaching, only one language is used to teach each given academic subject. This tenet known as the one subject-one language rule avoids mixing languages in formal schooling because it may hinder learning. The aim of this study was to test the scientific ground of this assumption by investigating the consequences of acquiring new concepts using a method in which two languages are mixed as compared to a purely monolingual method. Native balanced bilingual speakers of Basque and Spanish-adults (Experiment 1 and children (Experiment 2-learnt new concepts by associating two different features to novel objects. Half of the participants completed the learning process in a multilingual context (one feature was described in Basque and the other one in Spanish; while the other half completed the learning phase in a purely monolingual context (both features were described in Spanish. Different measures of learning were taken, as well as direct and indirect indicators of concept consolidation. We found no evidence in favor of the non-mixing method when comparing the results of two groups in either experiment, and thus failed to give scientific support for the educational premise of the one subject-one language rule.

What Do You Think You Are Measuring? A Mixed-Methods Procedure for Assessing the Content Validity of Test Items and Theory-Based Scaling

Science.gov (United States)

Koller, Ingrid; Levenson, Michael R.; Glück, Judith

2017-01-01

The valid measurement of latent constructs is crucial for psychological research. Here, we present a mixed-methods procedure for improving the precision of construct definitions, determining the content validity of items, evaluating the representativeness of items for the target construct, generating test items, and analyzing items on a theoretical basis. To illustrate the mixed-methods content-scaling-structure (CSS) procedure, we analyze the Adult Self-Transcendence Inventory, a self-report measure of wisdom (ASTI, Levenson et al., 2005). A content-validity analysis of the ASTI items was used as the basis of psychometric analyses using multidimensional item response models (N = 1215). We found that the new procedure produced important suggestions concerning five subdimensions of the ASTI that were not identifiable using exploratory methods. The study shows that the application of the suggested procedure leads to a deeper understanding of latent constructs. It also demonstrates the advantages of theory-based item analysis. PMID:28270777

Development of a PCR test for identification of Haemophilus somnus in pure and mixed cultures

DEFF Research Database (Denmark)

Angen, Øystein; Ahrens, Peter; Tegtmeier, Conny

1998-01-01

a single colony of H. somnus in the presence of 10(9) CFU of P. multocida even after 2 days of incubation. In conclusion, the present PCR test has been shown to represent a specific test for identification of H. somnus both in pure and mixed cultures. It represents a quick, sensitive and reliable method...... rise to an amplicon in the PCR test. The performance of the test on mixed cultures was evaluated by adding P. multocida to serial dilutions of H. somnus and incubating the agarplates for 1 and 2 days. This showed that the PCR test applied to the harvest from an agarplate can be expected to detect...

Can mixed assessment methods make biology classes more equitable?

Science.gov (United States)

Cotner, Sehoya; Ballen, Cissy J

2017-01-01

Many factors have been proposed to explain the attrition of women in science, technology, engineering and math fields, among them the lower performance of women in introductory courses resulting from deficits in incoming preparation. We focus on the impact of mixed methods of assessment, which minimizes the impact of high-stakes exams and rewards other methods of assessment such as group participation, low-stakes quizzes and assignments, and in-class activities. We hypothesized that these mixed methods would benefit individuals who otherwise underperform on high-stakes tests. Here, we analyze gender-based performance trends in nine large (N > 1000 students) introductory biology courses in fall 2016. Females underperformed on exams compared to their male counterparts, a difference that does not exist with other methods of assessment that compose course grade. Further, we analyzed three case studies of courses that transitioned their grading schemes to either de-emphasize or emphasize exams as a proportion of total course grade. We demonstrate that the shift away from an exam emphasis consequently benefits female students, thereby closing gaps in overall performance. Further, the exam performance gap itself is reduced when the exams contribute less to overall course grade. We discuss testable predictions that follow from our hypothesis, and advocate for the use of mixed methods of assessments (possibly as part of an overall shift to active learning techniques). We conclude by challenging the student deficit model, and suggest a course deficit model as explanatory of these performance gaps, whereby the microclimate of the classroom can either raise or lower barriers to success for underrepresented groups in STEM.

Centimeter-Level Positioning Using an Efficient New Baseband Mixing and Despreading Method for Software GNSS Receivers

Directory of Open Access Journals (Sweden)

G. Lachapelle

2007-10-01

Full Text Available This paper presents an efficient new method for performing the baseband mixing and despreading operations in a software-based GNSS receiver, and demonstrates that the method is capable of providing measurements for centimeter-level positioning accuracy. The method uses a single frequency carrier replica for the baseband mixing process, enabling all satellites to perform mixing simultaneously and yielding considerable computational savings. To compensate for signal-to-noise ratio (SNR losses caused by using a single frequency carrier replica, the integration interval after despreading is divided into subintervals, and the output from each subinterval then compensated for the known frequency error. Using this approach, receiver processing times are shown to be reduced by approximately 21% relative to the next fastest method when tracking seven satellites. The paper shows the mathematical derivation of the new algorithm, discusses practical considerations, and demonstrates its performance using simulations and real data. Results show that the new method is able to generate pseudorange and carrier phase measurements with the same accuracy as traditional methods. Stand-alone positioning accuracy is at the meter level, while differential processing can produce fixed ambiguity carrier phase positions accurate to the centimeter level.

An 8-year experience with routine SL mix patch testing supplemented with Compositae mix in Denmark

DEFF Research Database (Denmark)

Paulsen, E; Andersen, Klaus Ejner; Hausen, B M

2001-01-01

Routine patch testing with sesquiterpene lactone (SL) mix, supplemented with Compositae mix (CM) and other Compositae extracts and allergens where appropriate, was evaluated over an 8-year period. 190 of 4386 patients tested (4.3%) were Compositae-sensitive, 143 females (mean age 51.5 years) and ...

A New Wavelet Threshold Determination Method Considering Interscale Correlation in Signal Denoising

Directory of Open Access Journals (Sweden)

Can He

2015-01-01

Full Text Available Due to simple calculation and good denoising effect, wavelet threshold denoising method has been widely used in signal denoising. In this method, the threshold is an important parameter that affects the denoising effect. In order to improve the denoising effect of the existing methods, a new threshold considering interscale correlation is presented. Firstly, a new correlation index is proposed based on the propagation characteristics of the wavelet coefficients. Then, a threshold determination strategy is obtained using the new index. At the end of the paper, a simulation experiment is given to verify the effectiveness of the proposed method. In the experiment, four benchmark signals are used as test signals. Simulation results show that the proposed method can achieve a good denoising effect under various signal types, noise intensities, and thresholding functions.

Numerical evaluation of fluid mixing phenomena in boiling water reactor using advanced interface tracking method

International Nuclear Information System (INIS)

Yoshida, Hiroyuki; Takase, Kazuyuki

2008-01-01

Thermal-hydraulic design of the current boiling water reactor (BWR) is performed with the subchannel analysis codes which incorporated the correlations based on empirical results including actual-size tests. Then, for the Innovative Water Reactor for Flexible Fuel Cycle (FLWR) core, an actual size test of an embodiment of its design is required to confirm or modify such correlations. In this situation, development of a method that enables the thermal-hydraulic design of nuclear reactors without these actual size tests is desired, because these tests take a long time and entail great cost. For this reason, we developed an advanced thermal-hydraulic design method for FLWRs using innovative two-phase flow simulation technology. In this study, a detailed Two-Phase Flow simulation code using advanced Interface Tracking method: TPFIT is developed to calculate the detailed information of the two-phase flow. In this paper, firstly, we tried to verify the TPFIT code by comparing it with the existing 2-channel air-water mixing experimental results. Secondary, the TPFIT code was applied to simulation of steam-water two-phase flow in a model of two subchannels of a current BWRs and FLWRs rod bundle. The fluid mixing was observed at a gap between the subchannels. The existing two-phase flow correlation for fluid mixing is evaluated using detailed numerical simulation data. This data indicates that pressure difference between fluid channels is responsible for the fluid mixing, and thus the effects of the time average pressure difference and fluctuations must be incorporated in the two-phase flow correlation for fluid mixing. When inlet quality ratio of subchannels is relatively large, it is understood that evaluation precision of the existing two-phase flow correlations for fluid mixing are relatively low. (author)

A Preliminary Rubric Design to Evaluate Mixed Methods Research

Science.gov (United States)

Burrows, Timothy J.

2013-01-01

With the increase in frequency of the use of mixed methods, both in research publications and in externally funded grants there are increasing calls for a set of standards to assess the quality of mixed methods research. The purpose of this mixed methods study was to conduct a multi-phase analysis to create a preliminary rubric to evaluate mixed…

Signal Compression in Automatic Ultrasonic testing of Rails

Directory of Open Access Journals (Sweden)

Tomasz Ciszewski

2007-01-01

Full Text Available Full recording of the most important information carried by the ultrasonic signals allows realizing statistical analysis of measurement data. Statistical analysis of the results gathered during automatic ultrasonic tests gives data which lead, together with use of features of measuring method, differential lossy coding and traditional method of lossless data compression (Huffman’s coding, dictionary coding, to a comprehensive, efficient data compression algorithm. The subject of the article is to present the algorithm and the benefits got by using it in comparison to alternative compression methods. Storage of large amount  of data allows to create an electronic catalogue of ultrasonic defects. If it is created, the future qualification system training in the new solutions of the automat for test in rails will be possible.

Photon statistics of pulse-pumped four-wave mixing in fiber with weak signal injection

Science.gov (United States)

Nan-Nan, Liu; Yu-Hong, Liu; Jia-Min, Li; Xiao-Ying, Li

2016-07-01

We study the photon statistics of pulse-pumped four-wave mixing in fibers with weak coherent signal injection by measuring the intensity correlation functions of individual signal and idler fields. The experimental results show that the intensity correlation function of individual signal (idler) field decreases with the intensity of signal injection. After applying narrow band filter in signal (idler) band, the value of decreases from 1.9 ± 0.02 (1.9 ± 0.02) to 1.03 ± 0.02 (1.05 ± 0.02) when the intensity of signal injection varies from 0 to 120 photons/pulse. The results indicate that the photon statistics changes from Bose-Einstein distribution to Poisson distribution. We calculate the intensity correlation functions by using the multi-mode theory of four-wave mixing in fibers. The theoretical curves well fit the experimental results. Our investigation will be useful for mitigating the crosstalk between quantum and classical channels in a dense wavelength division multiplexing network. Project supported by the National Natural Science Foundation of China (Grant No. 11527808), the State Key Development Program for Basic Research of China (Grant No. 2014CB340103), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120032110055), the Natural Science Foundation of Tianjin, China (Grant No. 14JCQNJC02300), the Program for Changjiang Scholars and Innovative Research Team in University, China, and the Program of Introducing Talents of Discipline to Universities, China (Grant No. B07014).

Pulse Jet Mixing Tests With Noncohesive Solids

Energy Technology Data Exchange (ETDEWEB)

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro; Bailey, Sharon A.; Bower, John C.; Denslow, Kayte M.; Eakin, David E.; Elmore, Monte R.; Gauglitz, Phillip A.; Guzman, Anthony D.; Hatchell, Brian K.; Hopkins, Derek F.; Hurley, David E.; Johnson, Michael D.; Kirihara, Leslie J.; Lawler, Bruce D.; Loveland, Jesse S.; Mullen, O Dennis; Pekour, Mikhail S.; Peters, Timothy J.; Robinson, Peter J.; Russcher, Michael S.; Sande, Susan; Santoso, Christian; Shoemaker, Steven V.; Silva, Steve M.; Smith, Devin E.; Su, Yin-Fong; Toth, James J.; Wiberg, John D.; Yu, Xiao-Ying; Zuljevic, Nino

2009-05-11

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important to release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy

[Mixed methods research in public health: issues and illustration].

Science.gov (United States)

Guével, Marie-Renée; Pommier, Jeanine

2012-01-01

For many years, researchers in a range of fields have combined quantitative and qualitative methods. However, the combined use of quantitative and qualitative methods has only recently been conceptualized and defined as mixed methods research. Some authors have described the emerging field as a third methodological tradition (in addition to the qualitative and quantitative traditions). Mixed methods research combines different perspectives and facilitates the study of complex interventions or programs, particularly in public health, an area where interdisciplinarity is critical. However, the existing literature is primarily in English. By contrast, the literature in French remains limited. The purpose of this paper is to present the emergence of mixed methods research for francophone public health specialists. A literature review was conducted to identify the main characteristics of mixed methods research. The results provide an overall picture of the mixed methods approach through its history, definitions, and applications, and highlight the tools developed to clarify the approach (typologies) and to implement it (integration of results and quality standards). The tools highlighted in the literature review are illustrated by a study conducted in France. Mixed methods research opens new possibilities for examining complex research questions and provides relevant and promising opportunities for addressing current public health issues in France.

Writing a Mixed Methods Report in Social Work Research

Science.gov (United States)

Bronstein, Laura R.; Kovacs, Pamela J.

2013-01-01

This article briefly chronicles the development of mixed methods research and its use in social work. We then move onto a discussion of terms and designs, reasons for (and for not) using mixed methods. Drawing upon exemplars, we address how to write up a mixed methods study when (1) the sample is single; single for one part, with a subset for the…

The "movement" of mixed methods research and the role of educators

Directory of Open Access Journals (Sweden)

John W. Creswell

2008-08-01

Full Text Available The landscape of research is continually evolving, enabling researchers to study increasingly complex phenomena. Educational researchers have propelled much of this forward progress and have developed novel methodologies to provide increasingly sound and complete evidence. Mixed methods research has emerged alongside quantitative and qualitative approaches as an important tool for researchers. In this article our overall aim is to better acquaint educational scholars with the mixed methods field by articulating the development of the mixed methods field and by citing current trends and issues. The role of educational researchers in the evolution of mixed methods research is high-lighted. The early and ongoing dialogue of mixed methods research is multi-disciplinary in nature with current writings across fields. The current debate over key aspects of mixed methods research is now in progress and is ripe for future contributions. Even the very nature of what constitutes mixed methods research is being discussed among scholars. Understanding and advancing the mixed methods field is an important goal for methodologists and researchers. With the increased interest and enthusiasm for mixed methods research, it is likely that the dialogue surrounding mixed methods approaches will thrive, continuing the movement of the field.

Guidelines for Conducting Mixed-methods Research: An Extension and Illustration.

OpenAIRE

Venkatesh, Viswanath

2016-01-01

In this paper, we extend the guidelines of Venkatesh et al. (2013) for mixed-methods research by identifying and integrating variations in mixed-methods research. By considering 14 properties of mixed-methods research (e.g., purposes, research questions, epistemological assumptions), our guidelines demonstrate how researchers can flexibly identify the existing variations in mixed-methods research and proceed accordingly with a study design that suits their needs. To make the guide...

Single-Case Designs and Qualitative Methods: Applying a Mixed Methods Research Perspective

Science.gov (United States)

Hitchcock, John H.; Nastasi, Bonnie K.; Summerville, Meredith

2010-01-01

The purpose of this conceptual paper is to describe a design that mixes single-case (sometimes referred to as single-subject) and qualitative methods, hereafter referred to as a single-case mixed methods design (SCD-MM). Minimal attention has been given to the topic of applying qualitative methods to SCD work in the literature. These two…

Analysis research on mixing characteristics of lower plenum of Qinshan phase Ⅱ NPP by CFD method

International Nuclear Information System (INIS)

Mao Huihui; He Peifeng; Lu Chuan; Zhang Hongliang

2015-01-01

The flowing and mixing characteristics of the lower plenum of Qinshan Phase n NPP were analyzed by CFD method. The calculation results were compared with the results of the reactor hydraulic simulation test. On core inlet mass flow distributions, both upwind and high resolution advection schemes show good agreements with test results. While on lower plenum mixing characteristics, the calculation results from either upwind or high resolution advection schemes show relatively large differences to the test data. Relatively, upwind advection schemes predict better anticipations on maximum and minimum mixing factors. Furthermore, whether or not considering helix flow by main pump is the most possible key factor that leads to difference between CFD calculation and test results. (authors)

Reflections on Mixing Methods in Applied Linguistics Research

Science.gov (United States)

Hashemi, Mohammad R.

2012-01-01

This commentary advocates the use of mixed methods research--that is the integration of qualitative and quantitative methods in a single study--in applied linguistics. Based on preliminary findings from a research project in progress, some reflections on the current practice of mixing methods as a new trend in applied linguistics are put forward.…

Transformative, Mixed Methods Checklist for Psychological Research with Mexican Americans

Science.gov (United States)

Canales, Genevieve

2013-01-01

This is a description of the creation of a research methods tool, the "Transformative, Mixed Methods Checklist for Psychological Research With Mexican Americans." For conducting literature reviews of and planning mixed methods studies with Mexican Americans, it contains evaluative criteria calling for transformative mixed methods, perspectives…

Mathematical properties of a semi-classical signal analysis method: Noisy signal case

KAUST Repository

Liu, Dayan

2012-08-01

Recently, a new signal analysis method based on a semi-classical approach has been proposed [1]. The main idea in this method is to interpret a signal as a potential of a Schrodinger operator and then to use the discrete spectrum of this operator to analyze the signal. In this paper, we are interested in a mathematical analysis of this method in discrete case considering noisy signals. © 2012 IEEE.

Mathematical properties of a semi-classical signal analysis method: Noisy signal case

KAUST Repository

Liu, Dayan; Laleg-Kirati, Taous-Meriem

2012-01-01

Recently, a new signal analysis method based on a semi-classical approach has been proposed [1]. The main idea in this method is to interpret a signal as a potential of a Schrodinger operator and then to use the discrete spectrum of this operator to analyze the signal. In this paper, we are interested in a mathematical analysis of this method in discrete case considering noisy signals. © 2012 IEEE.

How can male rates of HIV testing be increased? Recommendations from a mixed methods study in southern Malawi.

Science.gov (United States)

Rankin-Williams, Amy C; Geoffroy, Elizabeth M; Schell, Ellen S; Mguntha, Andrew M

2017-11-01

In southern Malawi, 12.8% of adults are HIV positive. Men are less likely to have been tested than women. We investigated men's HIV knowledge and the attitudes, influencers, facilitators and barriers affecting HIV testing. We conducted an explanatory mixed-methods study with analysis of secondary quantitative data from 425 rural men collected in January 2014 (time 1) and April 2015 (time 2) and qualitative interviews with 50 men in September 2015. All respondents lived in villages receiving HIV education and testing. Quantitative data revealed that comprehensive HIV knowledge increased and was associated with having been tested by time 2. Educational level was positively associated with having been tested. Men's reasons for not getting tested were fear of learning their HIV status, fear of rejection by partners and wives and fear of discrimination. Wives influenced men's opinions about healthcare. The qualitative results demonstrated that men feared being seen at test sites and feared discrimination. Wives had the greatest reported influence on male testing. Men perceived services as female-oriented and stigmatizing. They preferred door-to-door testing. Providers can improve uptake by increasing men's HIV knowledge, leveraging the influence of spouses and offering door-to-door testing with male health workers. © The Author(s) 2017. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Achieving Integration in Mixed Methods Designs—Principles and Practices

OpenAIRE

Fetters, Michael D; Curry, Leslie A; Creswell, John W

2013-01-01

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participato...

The use of mixed methods research in interdisciplinary educational journals

OpenAIRE

López-Fernández, Olatz; Molina Azorín, José Francisco

2011-01-01

Mixed methods research is becoming increasingly important in several scientific areas. The analysis of prevalence rates is a new line of research that has emerged in mixed methods research, and this methodological approach has only been applied carefully in a handful of journals. The purpose of this article was to analyse the prevalence of mixed methods research in interdisciplinary educational journals. Moreover, the main characteristics of the mixed methods articles identified were examined...

A Novel Partial Discharge Ultra-High Frequency Signal De-Noising Method Based on a Single-Channel Blind Source Separation Algorithm

Directory of Open Access Journals (Sweden)

Liangliang Wei

2018-02-01

Full Text Available To effectively de-noise the Gaussian white noise and periodic narrow-band interference in the background noise of partial discharge ultra-high frequency (PD UHF signals in field tests, a novel de-noising method, based on a single-channel blind source separation algorithm, is proposed. Compared with traditional methods, the proposed method can effectively de-noise the noise interference, and the distortion of the de-noising PD signal is smaller. Firstly, the PD UHF signal is time-frequency analyzed by S-transform to obtain the number of source signals. Then, the single-channel detected PD signal is converted into multi-channel signals by singular value decomposition (SVD, and background noise is separated from multi-channel PD UHF signals by the joint approximate diagonalization of eigen-matrix method. At last, the source PD signal is estimated and recovered by the l1-norm minimization method. The proposed de-noising method was applied on the simulation test and field test detected signals, and the de-noising performance of the different methods was compared. The simulation and field test results demonstrate the effectiveness and correctness of the proposed method.

Algebraic Methods to Design Signals

Science.gov (United States)

2015-08-27

to date on designing signals using algebraic and combinatorial methods. Mathematical tools from algebraic number theory, representation theory and... combinatorial objects in designing signals for communication purposes. Sequences and arrays with desirable autocorrelation properties have many...multiple access methods in mobile radio communication systems. We continue our mathematical framework based on group algebras, character theory

Applications of mixed-methods methodology in clinical pharmacy research.

Science.gov (United States)

Hadi, Muhammad Abdul; Closs, S José

2016-06-01

Introduction Mixed-methods methodology, as the name suggests refers to mixing of elements of both qualitative and quantitative methodologies in a single study. In the past decade, mixed-methods methodology has gained popularity among healthcare researchers as it promises to bring together the strengths of both qualitative and quantitative approaches. Methodology A number of mixed-methods designs are available in the literature and the four most commonly used designs in healthcare research are: the convergent parallel design, the embedded design, the exploratory design, and the explanatory design. Each has its own unique advantages, challenges and procedures and selection of a particular design should be guided by the research question. Guidance on designing, conducting and reporting mixed-methods research is available in the literature, so it is advisable to adhere to this to ensure methodological rigour. When to use it is best suited when the research questions require: triangulating findings from different methodologies to explain a single phenomenon; clarifying the results of one method using another method; informing the design of one method based on the findings of another method, development of a scale/questionnaire and answering different research questions within a single study. Two case studies have been presented to illustrate possible applications of mixed-methods methodology. Limitations Possessing the necessary knowledge and skills to undertake qualitative and quantitative data collection, analysis, interpretation and integration remains the biggest challenge for researchers conducting mixed-methods studies. Sequential study designs are often time consuming, being in two (or more) phases whereas concurrent study designs may require more than one data collector to collect both qualitative and quantitative data at the same time.

The Role of Cohesive Particle Interactions on Solids Uniformity and Mobilization During Jet Mixing: Testing Recommendations

Energy Technology Data Exchange (ETDEWEB)

Gauglitz, Phillip A.; Wells, Beric E.; Bamberger, Judith A.; Fort, James A.; Chun, Jaehun; Jenks, Jeromy WJ

2010-04-01

Radioactive waste that is currently stored in large underground tanks at the Hanford Site will be staged in selected double-shell tanks (DSTs) and then transferred to the Waste Treatment and Immobilization Plant (WTP). Before being transferred, the waste will be mixed, sampled, and characterized to determine if the waste composition and meets the waste feed specifications. Washington River Protection Solutions is conducting a Tank Mixing and Sampling Demonstration Program to determine the mixing effectiveness of the current baseline mixing system that uses two jet mixer pumps and the adequacy of the planned sampling method. The overall purpose of the demonstration program is to mitigate the technical risk associated with the mixing and sampling systems meeting the feed certification requirements for transferring waste to the WTP.The purpose of this report is to analyze existing data and evaluate whether scaled mixing tests with cohesive simulants are needed to meet the overall objectives of the small-scale mixing demonstration program. This evaluation will focus on estimating the role of cohesive particle interactions on various physical phenomena that occur in parts of the mixing process. A specific focus of the evaluation will be on the uniformity of suspended solids in the mixed region. Based on the evaluation presented in this report and the absence of definitive studies, the recommendation is to conduct scaled mixing tests with cohesive particles and augment the initial testing with non-cohesive particles. In addition, planning for the quantitative tests would benefit from having test results from some scoping experiments that would provide results on the general behavior when cohesive inter-particle forces are important.

Designing A Mixed Methods Study In Primary Care

Science.gov (United States)

Creswell, John W.; Fetters, Michael D.; Ivankova, Nataliya V.

2004-01-01

BACKGROUND Mixed methods or multimethod research holds potential for rigorous, methodologically sound investigations in primary care. The objective of this study was to use criteria from the literature to evaluate 5 mixed methods studies in primary care and to advance 3 models useful for designing such investigations. METHODS We first identified criteria from the social and behavioral sciences to analyze mixed methods studies in primary care research. We then used the criteria to evaluate 5 mixed methods investigations published in primary care research journals. RESULTS Of the 5 studies analyzed, 3 included a rationale for mixing based on the need to develop a quantitative instrument from qualitative data or to converge information to best understand the research topic. Quantitative data collection involved structured interviews, observational checklists, and chart audits that were analyzed using descriptive and inferential statistical procedures. Qualitative data consisted of semistructured interviews and field observations that were analyzed using coding to develop themes and categories. The studies showed diverse forms of priority: equal priority, qualitative priority, and quantitative priority. Data collection involved quantitative and qualitative data gathered both concurrently and sequentially. The integration of the quantitative and qualitative data in these studies occurred between data analysis from one phase and data collection from a subsequent phase, while analyzing the data, and when reporting the results. DISCUSSION We recommend instrument-building, triangulation, and data transformation models for mixed methods designs as useful frameworks to add rigor to investigations in primary care. We also discuss the limitations of our study and the need for future research. PMID:15053277

Modeling Left-Turn Driving Behavior at Signalized Intersections with Mixed Traffic Conditions

Directory of Open Access Journals (Sweden)

Hong Li

2016-01-01

Full Text Available In many developing countries, mixed traffic is the most common type of urban transportation; traffic of this type faces many major problems in traffic engineering, such as conflicts, inefficiency, and security issues. This paper focuses on the traffic engineering concerns on the driving behavior of left-turning vehicles caused by different degrees of pedestrian violations. The traffic characteristics of left-turning vehicles and pedestrians in the affected region at a signalized intersection were analyzed and a cellular-automata-based “following-conflict” driving behavior model that mainly addresses four basic behavior modes was proposed to study the conflict and behavior mechanisms of left-turning vehicles by mathematic methodologies. Four basic driving behavior modes were reproduced in computer simulations, and a logit model of the behavior mode choice was also developed to analyze the relative share of each behavior mode. Finally, the microscopic characteristics of driving behaviors and the macroscopic parameters of traffic flow in the affected region were all determined. These data are important reference for geometry and capacity design for signalized intersections. The simulation results show that the proposed models are valid and can be used to represent the behavior of left-turning vehicles in the case of conflicts with illegally crossing pedestrians. These results will have potential applications on improving traffic safety and traffic capacity at signalized intersections with mixed traffic conditions.

Can mixed assessment methods make biology classes more equitable?

Directory of Open Access Journals (Sweden)

Sehoya Cotner

Full Text Available Many factors have been proposed to explain the attrition of women in science, technology, engineering and math fields, among them the lower performance of women in introductory courses resulting from deficits in incoming preparation. We focus on the impact of mixed methods of assessment, which minimizes the impact of high-stakes exams and rewards other methods of assessment such as group participation, low-stakes quizzes and assignments, and in-class activities. We hypothesized that these mixed methods would benefit individuals who otherwise underperform on high-stakes tests. Here, we analyze gender-based performance trends in nine large (N > 1000 students introductory biology courses in fall 2016. Females underperformed on exams compared to their male counterparts, a difference that does not exist with other methods of assessment that compose course grade. Further, we analyzed three case studies of courses that transitioned their grading schemes to either de-emphasize or emphasize exams as a proportion of total course grade. We demonstrate that the shift away from an exam emphasis consequently benefits female students, thereby closing gaps in overall performance. Further, the exam performance gap itself is reduced when the exams contribute less to overall course grade. We discuss testable predictions that follow from our hypothesis, and advocate for the use of mixed methods of assessments (possibly as part of an overall shift to active learning techniques. We conclude by challenging the student deficit model, and suggest a course deficit model as explanatory of these performance gaps, whereby the microclimate of the classroom can either raise or lower barriers to success for underrepresented groups in STEM.

Application of the stress wave method to automatic signal matching and to statnamic predictions

NARCIS (Netherlands)

Esposito, G.; Courage, W.M.G.; Foeken, R.J. van

2000-01-01

The Statnamic method is an increasingly popular technique to carry out loading tests on cast in-situ piles. The method bas proved to be a cost-effective alternative to a static loading test. As-sociated to Unloading Point Method (UPM) and to automatie signal matching, the Statnamic testing technique

Optimizing a portable biosensor system for bacterial detection in milk based mix for ice cream

Directory of Open Access Journals (Sweden)

A. Biscotti

2018-04-01

Full Text Available One of the primary focuses of the food industry is providing products compliant with safety standards. The microbiological analysis helps in the identification of the presence of pathogen microorganisms in the food. The analysis with Agar Plate is the classic method. This approach guarantees a high accuracy, but it needs a long detection time (twenty-four to forty-eight hours, beyond high costs and skilled technician. In recent times have been proposed many different methods to have a faster response, and between them there is the impedance method. One of its features is that it is fast, in fact it requires between three to fourteen hours to obtain a reliable measurement. The system is accurate, and suitable to be executed automatically. To test this method has been used UHT Ice Cream Mix. A known volume of mix has been inoculated with increasing percentage of cultures of E. coli. The measurement of the impedance of the inoculated mix has been done by an electronic board designed for the application, and by applying a sinusoidal voltage to the test tube. The signal was digitally generated by the microprocessor, and supplied externally through a D.A. converter. The signal was then filtered to delete from its spectrum the high frequency components typical of the digitally generated signals. The data obtained from impedance instrument showed a reliable correspondence with those from the plate count. By working in less time compared to traditional methods, this tool is well suited for in-situ preliminary analysis in commercial and professional foodservice environment.

Mixed-Methods Research in the Discipline of Nursing.

Science.gov (United States)

Beck, Cheryl Tatano; Harrison, Lisa

2016-01-01

In this review article, we examined the prevalence and characteristics of 294 mixed-methods studies in the discipline of nursing. Creswell and Plano Clark's typology was most frequently used along with concurrent timing. Bivariate statistics was most often the highest level of statistics reported in the results. As for qualitative data analysis, content analysis was most frequently used. The majority of nurse researchers did not specifically address the purpose, paradigm, typology, priority, timing, interaction, or integration of their mixed-methods studies. Strategies are suggested for improving the design, conduct, and reporting of mixed-methods studies in the discipline of nursing.

Toward a Conceptualization of Mixed Methods Phenomenological Research

OpenAIRE

Mayoh, Joanne; Onwuegbuzie, A.J.

2015-01-01

Increasingly, researchers are recognizing the benefits of expanding research designs that are rooted in one tradition (i.e., monomethod design) into a design that incorporates or interfaces with the other tradition. The flexibility of phenomenologically driven methods provides one such example. Indeed, phenomenological research methods work extremely well as a component of mixed methods research approaches. However, to date, a mixed methods version of phenomenological research has not been fo...

Using mixed methods in music therapy health care research

DEFF Research Database (Denmark)

Bonde, Lars Ole

2015-01-01

»Mixed methods« (or »multiple methods») is a fairly new concept in music therapy research. It is inspired by recent methodological developments in social science, covering the interaction of quantitative and qualitative methods in one and the same research study. Mixed methods are not the same...... as the diversity or pluralism of methods advocated by many scholars who are critical towards the principles of evidence-based medicine. This article presents a concrete example of mixed methods in music therapy research: a psycho-social study of music therapy with female cancer survivors. Problems related...

Integrated circuit test-port architecture and method and apparatus of test-port generation

Science.gov (United States)

Teifel, John

2016-04-12

A method and apparatus are provided for generating RTL code for a test-port interface of an integrated circuit. In an embodiment, a test-port table is provided as input data. A computer automatically parses the test-port table into data structures and analyzes it to determine input, output, local, and output-enable port names. The computer generates address-detect and test-enable logic constructed from combinational functions. The computer generates one-hot multiplexer logic for at least some of the output ports. The one-hot multiplexer logic for each port is generated so as to enable the port to toggle between data signals and test signals. The computer then completes the generation of the RTL code.

Qualitative and mixed methods in mental health services and implementation research.

Science.gov (United States)

Palinkas, Lawrence A

2014-01-01

Qualitative and mixed methods play a prominent role in mental health services research. However, the standards for their use are not always evident, especially for those not trained in such methods. This article reviews the rationale and common approaches to using qualitative and mixed methods in mental health services and implementation research based on a review of the articles included in this special series along with representative examples from the literature. Qualitative methods are used to provide a "thick description" or depth of understanding to complement breadth of understanding afforded by quantitative methods, elicit the perspective of those being studied, explore issues that have not been well studied, develop conceptual theories or test hypotheses, or evaluate the process of a phenomenon or intervention. Qualitative methods adhere to many of the same principles of scientific rigor as quantitative methods but often differ with respect to study design, data collection, and data analysis strategies. For instance, participants for qualitative studies are usually sampled purposefully rather than at random and the design usually reflects an iterative process alternating between data collection and analysis. The most common techniques for data collection are individual semistructured interviews, focus groups, document reviews, and participant observation. Strategies for analysis are usually inductive, based on principles of grounded theory or phenomenology. Qualitative methods are also used in combination with quantitative methods in mixed-method designs for convergence, complementarity, expansion, development, and sampling. Rigorously applied qualitative methods offer great potential in contributing to the scientific foundation of mental health services research.

Mixed Methods in Intervention Research: Theory to Adaptation

Science.gov (United States)

Nastasi, Bonnie K.; Hitchcock, John; Sarkar, Sreeroopa; Burkholder, Gary; Varjas, Kristen; Jayasena, Asoka

2007-01-01

The purpose of this article is to demonstrate the application of mixed methods research designs to multiyear programmatic research and development projects whose goals include integration of cultural specificity when generating or translating evidence-based practices. The authors propose a set of five mixed methods designs related to different…

Designing a mixed methods study in primary care.

Science.gov (United States)

Creswell, John W; Fetters, Michael D; Ivankova, Nataliya V

2004-01-01

Mixed methods or multimethod research holds potential for rigorous, methodologically sound investigations in primary care. The objective of this study was to use criteria from the literature to evaluate 5 mixed methods studies in primary care and to advance 3 models useful for designing such investigations. We first identified criteria from the social and behavioral sciences to analyze mixed methods studies in primary care research. We then used the criteria to evaluate 5 mixed methods investigations published in primary care research journals. Of the 5 studies analyzed, 3 included a rationale for mixing based on the need to develop a quantitative instrument from qualitative data or to converge information to best understand the research topic. Quantitative data collection involved structured interviews, observational checklists, and chart audits that were analyzed using descriptive and inferential statistical procedures. Qualitative data consisted of semistructured interviews and field observations that were analyzed using coding to develop themes and categories. The studies showed diverse forms of priority: equal priority, qualitative priority, and quantitative priority. Data collection involved quantitative and qualitative data gathered both concurrently and sequentially. The integration of the quantitative and qualitative data in these studies occurred between data analysis from one phase and data collection from a subsequent phase, while analyzing the data, and when reporting the results. We recommend instrument-building, triangulation, and data transformation models for mixed methods designs as useful frameworks to add rigor to investigations in primary care. We also discuss the limitations of our study and the need for future research.

Joint test rig for tests and calibration of different methods of two-phase mass flow measurement

International Nuclear Information System (INIS)

John, H.; Erbacher, F.; Wanner, E.

1975-01-01

On behalf of the Federal Ministry of Research and Technology, the Institute of Reactor Components (IRB) has begun building a test rig which will be used for testing and calibrating the methods of measuring non-steady state two-phase mass flows developed by various research agencies. The test rig is designed for the generation of steam-water mixtures of any mixing ratio and a maximum pressure of 160 data. Depending on the mixing ratio, the mass flow will reach a maximum level of 10 to 20 t/h. The conceptual design phase of the test rig has largely been finished, the component ordering phase has begun. (orig.) [de

New generation HMA mix designs : accelerated pavement testing of a type C mix with the ALF machine.

Science.gov (United States)

2012-09-01

Recent changes to the Texas hot-mix asphalt (HMA) mix-design procedures, such as the adaption of the higher-stiffer performance-grade asphalt-binder grades and the Hamburg test, have ensured that the mixes that are routinely used on Texas highways ar...

The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

Science.gov (United States)

Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

2015-08-01

Three different internal mixing methods (Core-Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20-70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20-50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core-Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC-sulfate aerosol is about -3.18 W/m2 for the external method and -6.91 W/m2 for the internal methods at the surface, and -3.03/-1.56/-1.85 W/m2 for the external/Core-Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause.

Method for traceable measurement of LTE signals

Science.gov (United States)

Sunder Dash, Soumya; Pythoud, Frederic; Leuchtmann, Pascal; Leuthold, Juerg

2018-04-01

This contribution presents a reference setup to measure the power of the cell-specific resource elements present in downlink long term evolution (LTE) signals in a way that the measurements are traceable to the international system of units. This setup can be used to calibrate the LTE code-selective field probes that are used to measure the radiation of base stations for mobile telephony. It can also be used to calibrate LTE signal generators and receivers. The method is based on traceable scope measurements performed directly at the output of a measuring antenna. It implements offline digital signal processing demodulation algorithms that consider the digital down-conversion, timing synchronization, frequency synchronization, phase synchronization and robust LTE cell identification to produce the downlink time-frequency LTE grid. Experimental results on conducted test scenarios, both single-input-single-output and multiple-input-multiple-output antenna configuration, show promising results confirming measurement uncertainties of the order of 0.05 dB with a coverage factor of 2.

Application of empirical mode decomposition method for characterization of random vibration signals

Directory of Open Access Journals (Sweden)

Setyamartana Parman

2016-07-01

Full Text Available Characterization of finite measured signals is a great of importance in dynamical modeling and system identification. This paper addresses an approach for characterization of measured random vibration signals where the approach rests on a method called empirical mode decomposition (EMD. The applicability of proposed approach is tested in one numerical and experimental data from a structural system, namely spar platform. The results are three main signal components, comprising: noise embedded in the measured signal as the first component, first intrinsic mode function (IMF called as the wave frequency response (WFR as the second component and second IMF called as the low frequency response (LFR as the third component while the residue is the trend. Band-pass filter (BPF method is taken as benchmark for the results obtained from EMD method.

Waste receiving and processing module 2A mixing tests status report

International Nuclear Information System (INIS)

Weber, J.R.; Hull, K.J.

1994-01-01

The purpose of this report is to document the Phase II test conditions, observations, and results of this work. This report provides additional mixing performance test data and rheologic data that provide further indications that there are clear and distinct advantages in the preliminary choice of high-shear mixing alone, and high-shear dispersion in combination with, or followed by, a low-speed type mixer/stirrer for WRAP 2A facility design. Another objective was to determine if significant scale-up problems might exist in the various mix and mixer designs. In the later Phase 2 tests the test material quantities were significantly larger than in the Phase 1 tests

Mixed Methods Research Designs in Counseling Psychology

Science.gov (United States)

Hanson, William E.; Creswell, John W.; Clark, Vicki L. Plano; Petska, Kelly S.; Creswell, David J.

2005-01-01

With the increased popularity of qualitative research, researchers in counseling psychology are expanding their methodologies to include mixed methods designs. These designs involve the collection, analysis, and integration of quantitative and qualitative data in a single or multiphase study. This article presents an overview of mixed methods…

A Methodology for Conducting Integrative Mixed Methods Research and Data Analyses

Science.gov (United States)

Castro, Felipe González; Kellison, Joshua G.; Boyd, Stephen J.; Kopak, Albert

2011-01-01

Mixed methods research has gained visibility within the last few years, although limitations persist regarding the scientific caliber of certain mixed methods research designs and methods. The need exists for rigorous mixed methods designs that integrate various data analytic procedures for a seamless transfer of evidence across qualitative and quantitative modalities. Such designs can offer the strength of confirmatory results drawn from quantitative multivariate analyses, along with “deep structure” explanatory descriptions as drawn from qualitative analyses. This article presents evidence generated from over a decade of pilot research in developing an integrative mixed methods methodology. It presents a conceptual framework and methodological and data analytic procedures for conducting mixed methods research studies, and it also presents illustrative examples from the authors' ongoing integrative mixed methods research studies. PMID:22167325

GRAPHICS-IMAGE MIXED METHOD FOR LARGE-SCALE BUILDINGS RENDERING

Directory of Open Access Journals (Sweden)

Y. Zhou

2018-05-01

Full Text Available Urban 3D model data is huge and unstructured, LOD and Out-of-core algorithm are usually used to reduce the amount of data that drawn in each frame to improve the rendering efficiency. When the scene is large enough, even the complex optimization algorithm is difficult to achieve better results. Based on the traditional study, a novel idea was developed. We propose a graphics and image mixed method for large-scale buildings rendering. Firstly, the view field is divided into several regions, the graphics-image mixed method used to render the scene on both screen and FBO, then blending the FBO with scree. The algorithm is tested on the huge CityGML model data in the urban areas of New York which contained 188195 public building models, and compared with the Cesium platform. The experiment result shows the system was running smoothly. The experimental results confirm that the algorithm can achieve more massive building scene roaming under the same hardware conditions, and can rendering the scene without vision loss.

Mixed-methods designs in mental health services research: a review.

Science.gov (United States)

Palinkas, Lawrence A; Horwitz, Sarah M; Chamberlain, Patricia; Hurlburt, Michael S; Landsverk, John

2011-03-01

Despite increased calls for use of mixed-methods designs in mental health services research, how and why such methods are being used and whether there are any consistent patterns that might indicate a consensus about how such methods can and should be used are unclear. Use of mixed methods was examined in 50 peer-reviewed journal articles found by searching PubMed Central and 60 National Institutes of Health (NIH)-funded projects found by searching the CRISP database over five years (2005-2009). Studies were coded for aims and the rationale, structure, function, and process for using mixed methods. A notable increase was observed in articles published and grants funded over the study period. However, most did not provide an explicit rationale for using mixed methods, and 74% gave priority to use of quantitative methods. Mixed methods were used to accomplish five distinct types of study aims (assess needs for services, examine existing services, develop new or adapt existing services, evaluate services in randomized controlled trials, and examine service implementation), with three categories of rationale, seven structural arrangements based on timing and weighting of methods, five functions of mixed methods, and three ways of linking quantitative and qualitative data. Each study aim was associated with a specific pattern of use of mixed methods, and four common patterns were identified. These studies offer guidance for continued progress in integrating qualitative and quantitative methods in mental health services research consistent with efforts by NIH and other funding agencies to promote their use.

Tests of Parameterized Langmuir Circulation Mixing in the Oceans Surface Mixed Layer II

Science.gov (United States)

2017-08-11

inertial oscillations in the ocean are governed by three-dimensional processes that are not accounted for in a one-dimensional simulation , and it was...Unlimited 52 Paul Martin (228) 688-5447 Recent large-eddy simulations (LES) of Langmuir circulation (LC) within the surface mixed layer (SML) of...used in the Navy Coastal Ocean Model (NCOM) and tested for (a) a simple wind-mixing case, (b) simulations of the upper ocean thermal structure at Ocean

Using mixed methods research in medical education: basic guidelines for researchers.

Science.gov (United States)

Schifferdecker, Karen E; Reed, Virginia A

2009-07-01

Mixed methods research involves the collection, analysis and integration of both qualitative and quantitative data in a single study. The benefits of a mixed methods approach are particularly evident when studying new questions or complex initiatives and interactions, which is often the case in medical education research. Basic guidelines for when to use mixed methods research and how to design a mixed methods study in medical education research are not readily available. The purpose of this paper is to remedy that situation by providing an overview of mixed methods research, research design models relevant for medical education research, examples of each research design model in medical education research, and basic guidelines for medical education researchers interested in mixed methods research. Mixed methods may prove superior in increasing the integrity and applicability of findings when studying new or complex initiatives and interactions in medical education research. They deserve an increased presence and recognition in medical education research.

Using mixed methods effectively in prevention science: designs, procedures, and examples.

Science.gov (United States)

Zhang, Wanqing; Watanabe-Galloway, Shinobu

2014-10-01

There is growing interest in using a combination of quantitative and qualitative methods to generate evidence about the effectiveness of health prevention, services, and intervention programs. With the emerging importance of mixed methods research across the social and health sciences, there has been an increased recognition of the value of using mixed methods for addressing research questions in different disciplines. We illustrate the mixed methods approach in prevention research, showing design procedures used in several published research articles. In this paper, we focused on two commonly used mixed methods designs: concurrent and sequential mixed methods designs. We discuss the types of mixed methods designs, the reasons for, and advantages of using a particular type of design, and the procedures of qualitative and quantitative data collection and integration. The studies reviewed in this paper show that the essence of qualitative research is to explore complex dynamic phenomena in prevention science, and the advantage of using mixed methods is that quantitative data can yield generalizable results and qualitative data can provide extensive insights. However, the emphasis of methodological rigor in a mixed methods application also requires considerable expertise in both qualitative and quantitative methods. Besides the necessary skills and effective interdisciplinary collaboration, this combined approach also requires an open-mindedness and reflection from the involved researchers.

Connecting the dots and merging meaning: using mixed methods to study primary care delivery transformation.

Science.gov (United States)

Scammon, Debra L; Tomoaia-Cotisel, Andrada; Day, Rachel L; Day, Julie; Kim, Jaewhan; Waitzman, Norman J; Farrell, Timothy W; Magill, Michael K

2013-12-01

To demonstrate the value of mixed methods in the study of practice transformation and illustrate procedures for connecting methods and for merging findings to enhance the meaning derived. An integrated network of university-owned, primary care practices at the University of Utah (Community Clinics or CCs). CC has adopted Care by Design, its version of the Patient Centered Medical Home. Convergent case study mixed methods design. Analysis of archival documents, internal operational reports, in-clinic observations, chart audits, surveys, semistructured interviews, focus groups, Centers for Medicare and Medicaid Services database, and the Utah All Payer Claims Database. Each data source enriched our understanding of the change process and understanding of reasons that certain changes were more difficult than others both in general and for particular clinics. Mixed methods enabled generation and testing of hypotheses about change and led to a comprehensive understanding of practice change. Mixed methods are useful in studying practice transformation. Challenges exist but can be overcome with careful planning and persistence. © Health Research and Educational Trust.

A low-jitter RF PLL frequency synthesizer with high-speed mixed-signal down-scaling circuits

International Nuclear Information System (INIS)

Tang Lu; Wang Zhigong; Xue Hong; He Xiaohu; Xu Yong; Sun Ling

2010-01-01

A low-jitter RF phase locked loop (PLL) frequency synthesizer with high-speed mixed-signal down-scaling circuits is proposed. Several techniques are proposed to reduce the design complexity and improve the performance of the mixed-signal down-scaling circuit in the PLL. An improved D-latch is proposed to increase the speed and the driving capability of the DMP in the down-scaling circuit. Through integrating the D-latch with 'OR' logic for dual-modulus operation, the delays associated with both the 'OR' and D-flip-flop (DFF) operations are reduced, and the complexity of the circuit is also decreased. The programmable frequency divider of the down-scaling circuit is realized in a new method based on deep submicron CMOS technology standard cells and a more accurate wire-load model. The charge pump in the PLL is also realized with a novel architecture to improve the current matching characteristic so as to reduce the jitter of the system. The proposed RF PLL frequency synthesizer is realized with a TSMC 0.18-μm CMOS process. The measured phase noise of the PLL frequency synthesizer output at 100 kHz offset from the center frequency is only -101.52 dBc/Hz. The circuit exhibits a low RMS jitter of 3.3 ps. The power consumption of the PLL frequency synthesizer is also as low as 36 mW at a 1.8 V power supply. (semiconductor integrated circuits)

Submicron InP DHBT technology for high-speed high-swing mixed-signal ICs

DEFF Research Database (Denmark)

Godin, Jean; Nodjiadjim, V.; Riet, Muriel

2008-01-01

We report on the development of a submicron InP DHBT technology, optimized for the fabrication of 50-GHz-clock mixed signal ICs. In-depth study of device geometry and structure has allowed to get the needed performances and yield. Special attention has been paid to critical thermal behavior. Vari...... applications of interest....

Wavelet analysis to decompose a vibration simulation signal to improve pre-distribution testing of packaging

Science.gov (United States)

Griffiths, K. R.; Hicks, B. J.; Keogh, P. S.; Shires, D.

2016-08-01

In general, vehicle vibration is non-stationary and has a non-Gaussian probability distribution; yet existing testing methods for packaging design employ Gaussian distributions to represent vibration induced by road profiles. This frequently results in over-testing and/or over-design of the packaging to meet a specification and correspondingly leads to wasteful packaging and product waste, which represent 15bn per year in the USA and €3bn per year in the EU. The purpose of the paper is to enable a measured non-stationary acceleration signal to be replaced by a constructed signal that includes as far as possible any non-stationary characteristics from the original signal. The constructed signal consists of a concatenation of decomposed shorter duration signals, each having its own kurtosis level. Wavelet analysis is used for the decomposition process into inner and outlier signal components. The constructed signal has a similar PSD to the original signal, without incurring excessive acceleration levels. This allows an improved and more representative simulated input signal to be generated that can be used on the current generation of shaker tables. The wavelet decomposition method is also demonstrated experimentally through two correlation studies. It is shown that significant improvements over current international standards for packaging testing are achievable; hence the potential for more efficient packaging system design is possible.

The Value of Developing a Mixed-Methods Program of Research.

Science.gov (United States)

Simonovich, Shannon

2017-07-01

This article contributes to the discussion of the value of utilizing mixed methodological approaches to conduct nursing research. To this end, the author of this article proposes creating a mixed-methods program of research over time, where both quantitative and qualitative data are collected and analyzed simultaneously, rather than focusing efforts on designing singular mixed-methods studies. A mixed-methods program of research would allow for the best of both worlds: precision through focus on one method at a time, and the benefits of creating a robust understanding of a phenomenon over the trajectory of one's career through examination from various methodological approaches.

Mixed-Methods Design in Biology Education Research: Approach and Uses

Science.gov (United States)

Warfa, Abdi-Rizak M.

2016-01-01

Educational research often requires mixing different research methodologies to strengthen findings, better contextualize or explain results, or minimize the weaknesses of a single method. This article provides practical guidelines on how to conduct such research in biology education, with a focus on mixed-methods research (MMR) that uses both quantitative and qualitative inquiries. Specifically, the paper provides an overview of mixed-methods design typologies most relevant in biology education research. It also discusses common methodological issues that may arise in mixed-methods studies and ways to address them. The paper concludes with recommendations on how to report and write about MMR. PMID:27856556

Analysis of mixed data methods & applications

CERN Document Server

de Leon, Alexander R

2013-01-01

A comprehensive source on mixed data analysis, Analysis of Mixed Data: Methods & Applications summarizes the fundamental developments in the field. Case studies are used extensively throughout the book to illustrate interesting applications from economics, medicine and health, marketing, and genetics. Carefully edited for smooth readability and seamless transitions between chaptersAll chapters follow a common structure, with an introduction and a concluding summary, and include illustrative examples from real-life case studies in developmental toxicolog

Mixed methods research design for pragmatic psychoanalytic studies.

Science.gov (United States)

Tillman, Jane G; Clemence, A Jill; Stevens, Jennifer L

2011-10-01

Calls for more rigorous psychoanalytic studies have increased over the past decade. The field has been divided by those who assert that psychoanalysis is properly a hermeneutic endeavor and those who see it as a science. A comparable debate is found in research methodology, where qualitative and quantitative methods have often been seen as occupying orthogonal positions. Recently, Mixed Methods Research (MMR) has emerged as a viable "third community" of research, pursuing a pragmatic approach to research endeavors through integrating qualitative and quantitative procedures in a single study design. Mixed Methods Research designs and the terminology associated with this emerging approach are explained, after which the methodology is explored as a potential integrative approach to a psychoanalytic human science. Both qualitative and quantitative research methods are reviewed, as well as how they may be used in Mixed Methods Research to study complex human phenomena.

An equivalent method of mixed dielectric constant in passive microwave/millimeter radiometric measurement

Science.gov (United States)

Su, Jinlong; Tian, Yan; Hu, Fei; Gui, Liangqi; Cheng, Yayun; Peng, Xiaohui

2017-10-01

Dielectric constant is an important role to describe the properties of matter. This paper proposes This paper proposes the concept of mixed dielectric constant(MDC) in passive microwave radiometric measurement. In addition, a MDC inversion method is come up, Ratio of Angle-Polarization Difference(RAPD) is utilized in this method. The MDC of several materials are investigated using RAPD. Brightness temperatures(TBs) which calculated by MDC and original dielectric constant are compared. Random errors are added to the simulation to test the robustness of the algorithm. Keywords: Passive detection, microwave/millimeter, radiometric measurement, ratio of angle-polarization difference (RAPD), mixed dielectric constant (MDC), brightness temperatures, remote sensing, target recognition.

Signal trend identification with fuzzy methods

International Nuclear Information System (INIS)

Reifman, J.; Tsoukalas, L. H.; Wang, X.; Wei, T. Y. C.

1999-01-01

A fuzzy-logic-based methodology for on-line signal trend identification is introduced. Although signal trend identification is complicated by the presence of noise, fuzzy logic can help capture important features of on-line signals and classify incoming power plant signals into increasing, decreasing and steady-state trend categories. In order to verify the methodology, a code named PROTREN is developed and tested using plant data. The results indicate that the code is capable of detecting transients accurately, identifying trends reliably, and not misinterpreting a steady-state signal as a transient one

ReMixT: clone-specific genomic structure estimation in cancer.

Science.gov (United States)

McPherson, Andrew W; Roth, Andrew; Ha, Gavin; Chauve, Cedric; Steif, Adi; de Souza, Camila P E; Eirew, Peter; Bouchard-Côté, Alexandre; Aparicio, Sam; Sahinalp, S Cenk; Shah, Sohrab P

2017-07-27

Somatic evolution of malignant cells produces tumors composed of multiple clonal populations, distinguished in part by rearrangements and copy number changes affecting chromosomal segments. Whole genome sequencing mixes the signals of sampled populations, diluting the signals of clone-specific aberrations, and complicating estimation of clone-specific genotypes. We introduce ReMixT, a method to unmix tumor and contaminating normal signals and jointly predict mixture proportions, clone-specific segment copy number, and clone specificity of breakpoints. ReMixT is free, open-source software and is available at http://bitbucket.org/dranew/remixt .

Test procedures for polyester immobilized salt-containing surrogate mixed wastes

International Nuclear Information System (INIS)

Biyani, R.K.; Hendrickson, D.W.

1997-01-01

These test procedures are written to meet the procedural needs of the Test Plan for immobilization of salt containing surrogate mixed waste using polymer resins, HNF-SD-RE-TP-026 and to ensure adequacy of conduct and collection of samples and data. This testing will demonstrate the use of four different polyester vinyl ester resins in the solidification of surrogate liquid and dry wastes, similar to some mixed wastes generated by DOE operations

Mixed and chelated waste test programs with bitumen solidification

International Nuclear Information System (INIS)

Simpson, S.I.; Morris, M.; Vidal, H.

1988-01-01

This paper presents the results of bitumen solidification tests on mixed wastes and chelated wastes. The French Atomic Energy Commission (CEA) performed demonstration tests on radioactive wastes contaminated with chelating agents for Associated Technologies, Inc. (ATI). The chelated wastes were produced and concentrated by Commonwealth Edison Co. as a result of reactor decontamination at Dresden Nuclear Station, Unit 1. Law Engineering in Charlotte, N. C. produced samples and performed tests on simulated heavy metal laden radioactive waste (mixed) to demonstrate the quality of the bituminous product. The simulation is intended to represent waste produced at Oak Ridge National Labs operated by Martin-Marietta

Apparatus and method for defect testing of integrated circuits

Science.gov (United States)

Cole, Jr., Edward I.; Soden, Jerry M.

2000-01-01

An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V.sub.DD, to an IC under test and measures a transient voltage component, V.sub.DDT, signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V.sub.DDT signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V.sub.DDT signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.

The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

International Nuclear Information System (INIS)

Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

2015-01-01

Three different internal mixing methods (Core–Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20–70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20–50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core–Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC–sulfate aerosol is about –3.18 W/m 2 for the external method and –6.91 W/m 2 for the internal methods at the surface, and –3.03/–1.56/–1.85 W/m 2 for the external/Core–Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause. - Highlights: • The aerosol optical properties with different mixing

Factors Affecting the Uptake of HIV Testing among Men: A Mixed-Methods Study in Rural Burkina Faso.

Directory of Open Access Journals (Sweden)

Manuela De Allegri

Full Text Available This study aimed to explore factors shaping the decision to undergo Human Immunodeficiency Virus (HIV testing among men in rural Burkina Faso.The study took place in 2009 in the Nouna Health District and adopted a triangulation mixed methods design. The quantitative component relied on data collected through a structured survey on a representative sample of 1130 households. The qualitative component relied on 38 in-depth interviews, with men purposely selected to represent variation in testing decision, age, and place of residence. A two-part model was conducted, with two distinct outcome variables, i.e. "being offered an HIV test" and "having done an HIV test". The qualitative data analysis relied on inductive coding conducted by three independent analysts.Of the 937 men, 357 had been offered an HIV test and 97 had taken the test. Younger age, household wealth, living in a village under demographic surveillance, and knowing that HIV testing is available at primary health facilities were all positively associated with the probability of being offered an HIV test. Household wealth and literacy were found to be positively associated, and distance was found to be negatively associated with the probability of having taken an HIV test. Qualitative findings indicated that the limited uptake of HIV testing was linked to poor knowledge on service availability and to low risk perceptions.With only 10% of the total sample ever having tested for HIV, our study confirmed that male HIV testing remains unacceptably low in Sub-Saharan Africa. This results from a combination of health system factors, indicating general barriers to access, and motivational factors, such as one's own knowledge of service availability and risk perceptions. Our findings suggested that using antenatal care and curative services as the exclusive entry points into HIV testing may not be sufficient to reach large portions of the male population. Thus, additional strategies are urgently

Neural Network Based Recognition of Signal Patterns in Application to Automatic Testing of Rails

Directory of Open Access Journals (Sweden)

Tomasz Ciszewski

2006-01-01

Full Text Available The paper describes the application of neural network for recognition of signal patterns in measuring data gathered by the railroad ultrasound testing car. Digital conversion of the measuring signal allows to store and process large quantities of data. The elaboration of smart, effective and automatic procedures recognizing the obtained patterns on the basisof measured signal amplitude has been presented. The test shows only two classes of pattern recognition. In authors’ opinion if we deliver big enough quantity of training data, presented method is applicable to a system that recognizes many classes.

Achieving Integration in Mixed Methods Designs—Principles and Practices

Science.gov (United States)

Fetters, Michael D; Curry, Leslie A; Creswell, John W

2013-01-01

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. PMID:24279835

A Novel Method Based on Oblique Projection Technology for Mixed Sources Estimation

Directory of Open Access Journals (Sweden)

Weijian Si

2014-01-01

Full Text Available Reducing the computational complexity of the near-field sources and far-field sources localization algorithms has been considered as a serious problem in the field of array signal processing. A novel algorithm caring for mixed sources location estimation based on oblique projection is proposed in this paper. The sources are estimated at two different stages and the sensor noise power is estimated and eliminated from the covariance which improve the accuracy of the estimation of mixed sources. Using the idea of compress, the range information of near-field sources is obtained by searching the partial area instead of the whole Fresnel area which can reduce the processing time. Compared with the traditional algorithms, the proposed algorithm has the lower computation complexity and has the ability to solve the two closed-spaced sources with high resolution and accuracy. The duplication of range estimation is also avoided. Finally, simulation results are provided to demonstrate the performance of the proposed method.

Mixed methods research: a design for emergency care research?

Science.gov (United States)

Cooper, Simon; Porter, Jo; Endacott, Ruth

2011-08-01

This paper follows previous publications on generic qualitative approaches, qualitative designs and action research in emergency care by this group of authors. Contemporary views on mixed methods approaches are considered, with a particular focus on the design choice and the amalgamation of qualitative and quantitative data emphasising the timing of data collection for each approach, their relative 'weight' and how they will be mixed. Mixed methods studies in emergency care are reviewed before the variety of methodological approaches and best practice considerations are presented. The use of mixed methods in clinical studies is increasing, aiming to answer questions such as 'how many' and 'why' in the same study, and as such are an important and useful approach to many key questions in emergency care.

Optimized Signaling Method for High-Speed Transmission Channels with Higher Order Transfer Function

Science.gov (United States)

Ševčík, Břetislav; Brančík, Lubomír; Kubíček, Michal

2017-08-01

In this paper, the selected results from testing of optimized CMOS friendly signaling method for high-speed communications over cables and printed circuit boards (PCBs) are presented and discussed. The proposed signaling scheme uses modified concept of pulse width modulated (PWM) signal which enables to better equalize significant channel losses during data high-speed transmission. Thus, the very effective signaling method to overcome losses in transmission channels with higher order transfer function, typical for long cables and multilayer PCBs, is clearly analyzed in the time and frequency domain. Experimental results of the measurements include the performance comparison of conventional PWM scheme and clearly show the great potential of the modified signaling method for use in low power CMOS friendly equalization circuits, commonly considered in modern communication standards as PCI-Express, SATA or in Multi-gigabit SerDes interconnects.

Mixed Methods in Emerging Academic Subdisciplines : The Case of Sport Management

NARCIS (Netherlands)

van der Roest, Jan Willem; Spaaij, Ramón; van Bottenburg, Maarten

2015-01-01

This article examines the prevalence and characteristics of mixed methods research in the relatively new subdiscipline of sport management. A mixed methods study is undertaken to evaluate the epistemological/philosophical, methodological, and technical levels of mixed methods design in sport

Mixed methods in emerging academic subdisciplines: the case of sport management

NARCIS (Netherlands)

van der Roest, J.-W.; Spaaij, R.; van Bottenburg, M.

2015-01-01

This article examines the prevalence and characteristics of mixed methods research in the relatively new subdiscipline of sport management. A mixed methods study is undertaken to evaluate the epistemological/philosophical, methodological, and technical levels of mixed methods design in sport

A brief measure of attitudes toward mixed methods research in psychology.

Science.gov (United States)

Roberts, Lynne D; Povee, Kate

2014-01-01

The adoption of mixed methods research in psychology has trailed behind other social science disciplines. Teaching psychology students, academics, and practitioners about mixed methodologies may increase the use of mixed methods within the discipline. However, tailoring and evaluating education and training in mixed methodologies requires an understanding of, and way of measuring, attitudes toward mixed methods research in psychology. To date, no such measure exists. In this article we present the development and initial validation of a new measure: Attitudes toward Mixed Methods Research in Psychology. A pool of 42 items developed from previous qualitative research on attitudes toward mixed methods research along with validation measures was administered via an online survey to a convenience sample of 274 psychology students, academics and psychologists. Principal axis factoring with varimax rotation on a subset of the sample produced a four-factor, 12-item solution. Confirmatory factor analysis on a separate subset of the sample indicated that a higher order four factor model provided the best fit to the data. The four factors; 'Limited Exposure,' '(in)Compatibility,' 'Validity,' and 'Tokenistic Qualitative Component'; each have acceptable internal reliability. Known groups validity analyses based on preferred research orientation and self-rated mixed methods research skills, and convergent and divergent validity analyses based on measures of attitudes toward psychology as a science and scientist and practitioner orientation, provide initial validation of the measure. This brief, internally reliable measure can be used in assessing attitudes toward mixed methods research in psychology, measuring change in attitudes as part of the evaluation of mixed methods education, and in larger research programs.

Demystifying Mixed Methods Research Design: A Review of the Literature

OpenAIRE

Gail D. Caruth

2013-01-01

Mixed methods research evolved in response to the observed limitations of both quantitative and qualitative designs and is a more complex method. The purpose of this paper was to examine mixed methods research in an attempt to demystify the design thereby allowing those less familiar with its design an opportunity to utilize it in future research. A review of the literature revealed that it has been gaining acceptance among researchers, researchers have begun using mixed methods research, it ...

Gray bootstrap method for estimating frequency-varying random vibration signals with small samples

Directory of Open Access Journals (Sweden)

Wang Yanqing

2014-04-01

Full Text Available During environment testing, the estimation of random vibration signals (RVS is an important technique for the airborne platform safety and reliability. However, the available methods including extreme value envelope method (EVEM, statistical tolerances method (STM and improved statistical tolerance method (ISTM require large samples and typical probability distribution. Moreover, the frequency-varying characteristic of RVS is usually not taken into account. Gray bootstrap method (GBM is proposed to solve the problem of estimating frequency-varying RVS with small samples. Firstly, the estimated indexes are obtained including the estimated interval, the estimated uncertainty, the estimated value, the estimated error and estimated reliability. In addition, GBM is applied to estimating the single flight testing of certain aircraft. At last, in order to evaluate the estimated performance, GBM is compared with bootstrap method (BM and gray method (GM in testing analysis. The result shows that GBM has superiority for estimating dynamic signals with small samples and estimated reliability is proved to be 100% at the given confidence level.

Development of a process for co-conversion of Pu-U nitrate mixed solutions to mixed oxide powder using microwave heating method

International Nuclear Information System (INIS)

Koizumi, Masumichi; Ohtsuka, Katsuyuki; Ohshima, Hirofumi; Isagawa, Hiroto; Akiyama, Hideo; Todokoro, Akio; Naruki, Kaoru

1983-01-01

For the complete nuclear fuel cycle, the development of a process for the co-conversion of Pu-U nitrate mixed solutions to mixed oxide powder has been performed along the line of non-proliferation policy of nuclear materials. A new co-conversion process using a microwave heating method has been developed and successfully demonstrated with good results using the test unit with a capacity of 2 kg MOX/d. Through the experiments and engineering test operations, several important data have been obtained concerning the feasibility of the test unit, powder characteristics and homogeneity of the product, and impurity pickups during denitration process. The results of these experimental operations show that the co-conversion process using a microwave heating method has many excellent advantages, such as good powder characteristics of the product, good homogeneity of Pu-U oxide, simplicity of the process, minimum liquid waste, no possibility of changing the Pu/U ratio and stable operability of the plant. Since August 1979, plutonium nitrate solution transported from the Tokai Reprocessing Plant has been converted to mixed oxide powder which has the Pu/U ratio = 1. The products have been processed to the ATR ''FUGEN'' reloading fuel. Based on the successful development of the co-conversion process, the microwave heating direct denitration facility with a 10 kg MOX/d capacity has been constructed adjacent to the reprocessing plant. This facility will come into hot operation by the fall of this year. For future development of the microwave heating method, a continuous direct denitration, a vitrification of high active liquid waste and a solidification of the plutonium-contaminated waste are investigated in Power Reactor and Nuclear Fuel Development Corp. (author)

How to Construct a Mixed Methods Research Design

OpenAIRE

Schoonenboom, Judith; Johnson, R. Burke

2017-01-01

This article provides researchers with knowledge of how to design a high quality mixed methods research study. To design a mixed study, researchers must understand and carefully consider each of the dimensions of mixed methods design, and always keep an eye on the issue of validity. We explain the seven major design dimensions: purpose, theoretical drive, timing (simultaneity and dependency), point of integration, typological versus interactive design approaches, planned versus emergent desig...

Expert system for eddy current signal analysis: non destructive testing of steam generator tubings

International Nuclear Information System (INIS)

Benoist, B.

1991-01-01

Automatic analysis, by computer, of defect signals in steam generator tubes, based on Eddy current multifrequency technique, is must often inefficient due to pilgrim noise. The first step is to use a method that allows us to eleminate the noise: the adaptative interpolation. Thanks to this method, which ensures reliable data on each channel, the analysis can be realised by taking into account the data corresponding to each basic or mixed channel. By correlating these diverse data, we can class the signals according to two types of defects: single defects (symmetrical), multiple defects (several in the same place). The second step is to use an expert system which allows a reliable diagnosis for whatever family the defect belongs to. According to this classification, analysis is continued and results in the characterization of the defect. The expert system has already been developed with the general purpose application expert system shell SUPER, which is briefly described. The knowledge base (SOCRATE) and the specific tools developed for this application are thoroughly described. The first results obtained with signals corresponding to real defects, that have been recorded in different places, are presented and discussed. The expert system is revealed efficient in all the studied cases, even with signals obtained in very noisy environments [fr

TESTING METHODS FOR MECHANICALLY IMPROVED SOILS: RELIABILITY AND VALIDITY

Directory of Open Access Journals (Sweden)

Ana Petkovšek

2017-10-01

Full Text Available A possibility of in-situ mechanical improvement for reducing the liquefaction potential of silty sands was investigated by using three different techniques: Vibratory Roller Compaction, Rapid Impact Compaction (RIC and Soil Mixing. Material properties at all test sites were investigated before and after improvement with the laboratory and the in situ tests (CPT, SDMT, DPSH B, static and dynamic load plate test, geohydraulic tests. Correlation between the results obtained by different test methods gave inconclusive answers.

Qualitative and Mixed Methods Social Media Research

Directory of Open Access Journals (Sweden)

Chareen L. Snelson

2016-02-01

Full Text Available Social media technologies have attracted substantial attention among many types of users including researchers who have published studies for several years. This article presents an overview of trends in qualitative and mixed methods social media research literature published from 2007 through 2013. A collection of 229 qualitative studies were identified through a systematic literature review process. A subset of 55 of these articles report studies involving a combination of qualitative and quantitative methods. Articles were reviewed, analyzed, and coded through a qualitative content analysis approach. Overall trends are presented with respect to the entire collection of articles followed by an analysis of mixed methods research approaches identified in the subset of 55 studies. The most commonly used research approaches involved collecting data from people through interview, focus group, and survey methodologies. Content analysis was the second most commonly used approach whereby researchers use Facebook posts, Tweets (Twitter posts, YouTube videos, or other social media content as a data source. Many of the studies involving combinations of quantitative and qualitative data followed a design resembling Creswell and Plano Clark’s basic mixed methods typology (e.g., convergent parallel, explanatory sequential, and exploratory sequential.

Bitumen rubber asphalt mix testing for South African pavement design method

CSIR Research Space (South Africa)

Anochie-Boateng, Joseph

2011-07-01

Full Text Available The South Africa National Road Agency Ltd has entered into a research and laboratory testing agreement with the CSIR to support the revision of the South African Pavement Design Method (SAPDM). The research includes characterising a bitumen...

A device for quantitative plutonium testing in mixed fuel by its neutron emission

International Nuclear Information System (INIS)

Gadzhiev, G.I.; Gorobets, A.K.; Golushko, V.V.; Dunaev, E.S.; Leshchenko, Yu.I.

1987-01-01

A device for quantitative plutonium testing in mixed fuel by its neutron emission is described. The method of ''assigned dead time'' for isolation of neutrons of spontaneous fission is used in the device. The main characteristics of the registrating equipment specifying the regime of measuring and affecting testing errors are presented. The results of spontaneous fission neutrons detection in the range up to 100 g of plutonium linearly depend on 240 Pu. Sensitivity of testing makes up about 28 pul./s per 1 g of 240 Pu

Mixed-methods research in pharmacy practice: recommendations for quality reporting. Part 2.

Science.gov (United States)

Hadi, Muhammad Abdul; Alldred, David Phillip; Closs, S José; Briggs, Michelle

2014-02-01

This is the second of two papers that explore the use of mixed-methods research in pharmacy practice. This paper discusses the rationale, applications, limitations and challenges of conducting mixed-methods research. As with other research methods, the choice of mixed-methods should always be justified because not all research questions require a mixed-methods approach. Mixed-methods research is particularly suitable when one dataset may be inadequate in answering the research question, an explanation of initial results is required, generalizability of qualitative findings is desired or broader and deeper understanding of a research problem is necessary. Mixed-methods research has its own challenges and limitations, which should be considered carefully while designing the study. There is a need to improve the quality of reporting of mixed-methods research. A framework for reporting mixed-methods research is proposed, for researchers and reviewers, with the intention of improving its quality. Pharmacy practice research can benefit from research that uses both 'numbers' (quantitative) and 'words' (qualitative) to develop a strong evidence base to support pharmacy-led services. © 2013 Royal Pharmaceutical Society.

Comparison of simultaneous patch testing with parthenolide and sesquiterpene lactone mix

DEFF Research Database (Denmark)

Orion, E; Paulsen, Evy; Andersen, Klaus Ejner

1998-01-01

Several studies have pointed out that the sesquiterpene lactone (SL) mix is a safe, though inadequate, screen for Compositae allergy. To test the usefulness of the sesquiterpene lactone parthenolide as a supplementary Compositae screening test to the mix, both were included in the standard series...

A brief measure of attitudes toward mixed methods research in psychology

Science.gov (United States)

Roberts, Lynne D.; Povee, Kate

2014-01-01

The adoption of mixed methods research in psychology has trailed behind other social science disciplines. Teaching psychology students, academics, and practitioners about mixed methodologies may increase the use of mixed methods within the discipline. However, tailoring and evaluating education and training in mixed methodologies requires an understanding of, and way of measuring, attitudes toward mixed methods research in psychology. To date, no such measure exists. In this article we present the development and initial validation of a new measure: Attitudes toward Mixed Methods Research in Psychology. A pool of 42 items developed from previous qualitative research on attitudes toward mixed methods research along with validation measures was administered via an online survey to a convenience sample of 274 psychology students, academics and psychologists. Principal axis factoring with varimax rotation on a subset of the sample produced a four-factor, 12-item solution. Confirmatory factor analysis on a separate subset of the sample indicated that a higher order four factor model provided the best fit to the data. The four factors; ‘Limited Exposure,’ ‘(in)Compatibility,’ ‘Validity,’ and ‘Tokenistic Qualitative Component’; each have acceptable internal reliability. Known groups validity analyses based on preferred research orientation and self-rated mixed methods research skills, and convergent and divergent validity analyses based on measures of attitudes toward psychology as a science and scientist and practitioner orientation, provide initial validation of the measure. This brief, internally reliable measure can be used in assessing attitudes toward mixed methods research in psychology, measuring change in attitudes as part of the evaluation of mixed methods education, and in larger research programs. PMID:25429281

Mixed Methods in Emerging Academic Subdisciplines: The Case of Sport Management

Science.gov (United States)

van der Roest, Jan-Willem; Spaaij, Ramón; van Bottenburg, Maarten

2015-01-01

This article examines the prevalence and characteristics of mixed methods research in the relatively new subdiscipline of sport management. A mixed methods study is undertaken to evaluate the epistemological/philosophical, methodological, and technical levels of mixed methods design in sport management research. The results indicate that mixed…

Twelve tips for getting started using mixed methods in medical education research.

Science.gov (United States)

Lavelle, Ellen; Vuk, Jasna; Barber, Carolyn

2013-04-01

Mixed methods research, which is gaining popularity in medical education, provides a new and comprehensive approach for addressing teaching, learning, and evaluation issues in the field. The aim of this article is to provide medical education researchers with 12 tips, based on consideration of current literature in the health professions and in educational research, for conducting and disseminating mixed methods research. Engaging in mixed methods research requires consideration of several major components: the mixed methods paradigm, types of problems, mixed method designs, collaboration, and developing or extending theory. Mixed methods is an ideal tool for addressing a full range of problems in medical education to include development of theory and improving practice.

Achieving integration in mixed methods designs-principles and practices.

Science.gov (United States)

Fetters, Michael D; Curry, Leslie A; Creswell, John W

2013-12-01

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs-exploratory sequential, explanatory sequential, and convergent-and through four advanced frameworks-multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. © Health Research and Educational Trust.

Goodness-of-fit tests in mixed models

KAUST Repository

Claeskens, Gerda; Hart, Jeffrey D.

2009-01-01

Mixed models, with both random and fixed effects, are most often estimated on the assumption that the random effects are normally distributed. In this paper we propose several formal tests of the hypothesis that the random effects and/or errors

Signal processing methods for in-situ creep specimen monitoring

Science.gov (United States)

Guers, Manton J.; Tittmann, Bernhard R.

2018-04-01

Previous work investigated using guided waves for monitoring creep deformation during accelerated life testing. The basic objective was to relate observed changes in the time-of-flight to changes in the environmental temperature and specimen gage length. The work presented in this paper investigated several signal processing strategies for possible application in the in-situ monitoring system. Signal processing methods for both group velocity (wave-packet envelope) and phase velocity (peak tracking) time-of-flight were considered. Although the Analytic Envelope found via the Hilbert transform is commonly applied for group velocity measurements, erratic behavior in the indicated time-of-flight was observed when this technique was applied to the in-situ data. The peak tracking strategies tested had generally linear trends, and tracking local minima in the raw waveform ultimately showed the most consistent results.

Mixed-methods research in pharmacy practice: basics and beyond (part 1).

Science.gov (United States)

Hadi, Muhammad Abdul; Alldred, David Phillip; Closs, S José; Briggs, Michelle

2013-10-01

This is the first of two papers which explore the use of mixed-methods research in pharmacy practice. In an era of evidence-based medicine and policy, high-quality research evidence is essential for the development of effective pharmacist-led services. Over the past decade, the use of mixed-methods research has become increasingly common in healthcare, although to date its use has been relatively limited in pharmacy practice research. In this article, the basic concepts of mixed-methods research including its definition, typologies and advantages in relation to pharmacy practice research are discussed. Mixed-methods research brings together qualitative and quantitative methodologies within a single study to answer or understand a research problem. There are a number of mixed-methods designs available, but the selection of an appropriate design must always be dictated by the research question. Importantly, mixed-methods research should not be seen as a 'tool' to collect qualitative and quantitative data, rather there should be some degree of 'integration' between the two data sets. If conducted appropriately, mixed-methods research has the potential to generate quality research evidence by combining strengths and overcoming the respective limitations of qualitative and quantitative methodologies. © 2012 Royal Pharmaceutical Society.

Patch tests with fragrance mix II and its components.

Science.gov (United States)

Pónyai, Györgyi; Németh, Ilona; Altmayer, Anita; Nagy, Gabriella; Irinyi, Beatrix; Battyáni, Zita; Temesvári, Erzsébet

2012-01-01

Fragrance mix II (FM II) was initiated to detect contact hypersenstitivity (CH) to fragrances that could not have been identified previously. The aim of this multicenter study was to map the frequency of CH to FM II and its components in Hungary. Six centers participated in the survey from 2009 to 2010. A total off 565 patients (434 women and 131 men) with former skin symptoms provoked by scented products were patch tested. The tests were performed with Brial GmbH D-Greven allergens. In the environmental patch test series, FM II, FM I, Myroxylon pereirae, colophonium, wood-tar mix, propolis, and sesquiterpene lactone mix were tested as fragrance allergens. The FM II components (citral, farnesol, coumarin, citronellol, α-hexyl-cinnamaldehyde, and hydroxy-isohexyl-3-cyclohexene-carboxaldehyde [Lyral]) were also tested. Contact hypersenstitivity to any fragrances was detected in 28.8%, to FM II in 17.2% of the patients. Contact hypersenstitivity to hydroxy-isohexyl-3-cyclohexene-carboxaldehyde was observed in 7.3%, to coumarin in 5.1%, to α-hexyl-cinnamaldehyde in 3.5%, to citral in 3.4%, to farnesol in 2.5%, and to citronellol in 1.2%. Of the FM II-positive cases, 48.4% showed isolated CH reaction. The frequency of CH to FM II is 17.2% in the tested, selected Hungarian population. The CH to FM II and its components could not have been revealed without the present test materials.

A Mixed Methods Content Analysis of the Research Literature in Science Education

Science.gov (United States)

Schram, Asta B.

2014-10-01

In recent years, more and more researchers in science education have been turning to the practice of combining qualitative and quantitative methods in the same study. This approach of using mixed methods creates possibilities to study the various issues that science educators encounter in more depth. In this content analysis, I evaluated 18 studies from science education journals as they relate to the definition, design, and overall practice of using mixed methods. I scrutinized a purposeful sample, derived from 3 journals (the International Journal of Science Education, the Journal of Research in Science Teaching, and the Research in Science Education) in terms of the type of data collected, timing, priority, design, the mixing of the 2 data strands in the studies, and the justifications authors provide for using mixed methods. Furthermore, the articles were evaluated in terms of how well they met contemporary definitions for mixed methods research. The studies varied considerably in the use and understanding of mixed methods. A systematic evaluation of the employment of mixed methods methodology was used to identify the studies that best reflected contemporary definitions. A comparison to earlier content analyses of mixed methods research indicates that researchers' knowledge of mixed methods methodology may be increasing. The use of this strategy in science education research calls, however, for an improved methodology, especially concerning the practice of mixing. Suggestions are given on how to best use this approach.

Development of Mix Design Method in Efforts to Increase Concrete Performance Using Portland Pozzolana Cement (PPC)

Science.gov (United States)

Krisnamurti; Soehardjono, A.; Zacoeb, A.; Wibowo, A.

2018-01-01

Earthquake disaster can cause infrastructure damage. Prevention of human casualties from disasters should do. Prevention efforts can do through improving the mechanical performance of building materials. To achieve high-performance concrete (HPC), usually used Ordinary Portland Cement (OPC). However, the most widely circulating cement types today are Portland Pozzolana Cement (PPC) or Portland Composite Cement (PCC). Therefore, the proportion of materials used in the HPC mix design needs to adjust to achieve the expected performance. This study aims to develop a concrete mix design method using PPC to fulfil the criteria of HPC. The study refers to the code/regulation of concrete mixtures that use OPC based on the results of laboratory testing. This research uses PPC material, gravel from Malang area, Lumajang sand, water, silica fume and superplasticizer of a polycarboxylate copolymer. The analyzed information includes the investigation results of aggregate properties, concrete mixed composition, water-binder ratio variation, specimen dimension, compressive strength and elasticity modulus of the specimen. The test results show that the concrete compressive strength achieves value between 25 MPa to 55 MPa. The mix design method that has developed can simplify the process of concrete mix design using PPC to achieve the certain desired performance of concrete.

Structural issues affecting mixed methods studies in health research: a qualitative study

Science.gov (United States)

2009-01-01

Background Health researchers undertake studies which combine qualitative and quantitative methods. Little attention has been paid to the structural issues affecting this mixed methods approach. We explored the facilitators and barriers to undertaking mixed methods studies in health research. Methods Face-to-face semi-structured interviews with 20 researchers experienced in mixed methods research in health in the United Kingdom. Results Structural facilitators for undertaking mixed methods studies included a perception that funding bodies promoted this approach, and the multidisciplinary constituency of some university departments. Structural barriers to exploiting the potential of these studies included a lack of education and training in mixed methods research, and a lack of templates for reporting mixed methods articles in peer-reviewed journals. The 'hierarchy of evidence' relating to effectiveness studies in health care research, with the randomised controlled trial as the gold standard, appeared to pervade the health research infrastructure. Thus integration of data and findings from qualitative and quantitative components of mixed methods studies, and dissemination of integrated outputs, tended to occur through serendipity and effort, further highlighting the presence of structural constraints. Researchers are agents who may also support current structures - journal reviewers and editors, and directors of postgraduate training courses - and thus have the ability to improve the structural support for exploiting the potential of mixed methods research. Conclusion The environment for health research in the UK appears to be conducive to mixed methods research but not to exploiting the potential of this approach. Structural change, as well as change in researcher behaviour, will be necessary if researchers are to fully exploit the potential of using mixed methods research. PMID:20003210

How to Construct a Mixed Methods Research Design.

Science.gov (United States)

Schoonenboom, Judith; Johnson, R Burke

2017-01-01

This article provides researchers with knowledge of how to design a high quality mixed methods research study. To design a mixed study, researchers must understand and carefully consider each of the dimensions of mixed methods design, and always keep an eye on the issue of validity. We explain the seven major design dimensions: purpose, theoretical drive, timing (simultaneity and dependency), point of integration, typological versus interactive design approaches, planned versus emergent design, and design complexity. There also are multiple secondary dimensions that need to be considered during the design process. We explain ten secondary dimensions of design to be considered for each research study. We also provide two case studies showing how the mixed designs were constructed.

Criteria for quantitative and qualitative data integration: mixed-methods research methodology.

Science.gov (United States)

Lee, Seonah; Smith, Carrol A M

2012-05-01

Many studies have emphasized the need and importance of a mixed-methods approach for evaluation of clinical information systems. However, those studies had no criteria to guide integration of multiple data sets. Integrating different data sets serves to actualize the paradigm that a mixed-methods approach argues; thus, we require criteria that provide the right direction to integrate quantitative and qualitative data. The first author used a set of criteria organized from a literature search for integration of multiple data sets from mixed-methods research. The purpose of this article was to reorganize the identified criteria. Through critical appraisal of the reasons for designing mixed-methods research, three criteria resulted: validation, complementarity, and discrepancy. In applying the criteria to empirical data of a previous mixed methods study, integration of quantitative and qualitative data was achieved in a systematic manner. It helped us obtain a better organized understanding of the results. The criteria of this article offer the potential to produce insightful analyses of mixed-methods evaluations of health information systems.

Mixed Methods Not Mixed Messages: Improving LibGuides with Student Usability Data

Directory of Open Access Journals (Sweden)

Nora Almeida

2017-12-01

Full Text Available Abstract Objective – This article describes a mixed methods usability study of research guides created using the LibGuides 2.0 platform conducted in 2016 at an urban, public university library. The goal of the study was to translate user design and learning modality preferences into executable design principles, and ultimately to improve the design and usage of LibGuides at the New York City College of Technology Library. Methods – User-centred design demands that stakeholders participate in each stage of an application’s development and that assumptions about user design preferences are validated through testing. Methods used for this usability study include: a task analysis on paper prototypes with a think aloud protocol (TAP, an advanced scribbling technique modeled on the work of Linek and Tochtermann (2015, and semi-structured interviews. The authors introduce specifics of each protocol in addition to data collection and analysis methods. Results – The authors present quantitative and qualitative student feedback on navigation layouts, terminology, and design elements and discuss concrete institutional and technical measures they will take to implement best practices. Additionally, the authors discuss students’ impressions of multimedia, text-based, and interactive instructional content in relation to specific research scenarios defined during the usability test. Conclusion – The authors translate study findings into best practices that can be incorporated into custom user-centric LibGuide templates and assets. The authors also discuss relevant correlations between students’ learning modality preferences and design feedback, and identify several areas that warrant further research. The authors believe this study will spark a larger discussion about relationships between instructional design, learning modalities, and research guide use contexts.

Net Analyte Signal Standard Additions Method for Simultaneous Determination of Sulfamethoxazole and Trimethoprim in Pharmaceutical Formulations and Biological Fluids

Directory of Open Access Journals (Sweden)

M. H. Givianrad

2012-01-01

Full Text Available The applicability of a novel net analyte signal standard addition method (NASSAM to the resolving of overlapping spectra corresponding to the sulfamethoxazole and trimethoprim was verified by UV-visible spectrophotometry. The results confirmed that the net analyte signal standard additions method with simultaneous addition of both analytes is suitable for the simultaneous determination of sulfamethoxazole and trimethoprim in aqueous media. Moreover, applying the net analyte signal standard additions method revealed that the two drugs could be determined simultaneously with the concentration ratios of sulfamethoxazole to trimethoprim varying from 1:35 to 60:1 in the mixed samples. In addition, the limits of detections were 0.26 and 0.23 μmol L-1 for sulfamethoxazole and trimethoprim, respectively. The proposed method has been effectively applied to the simultaneous determination of sulfamethoxazole and trimethoprim in some synthetic, pharmaceutical formulation and biological fluid samples.

Seizure classification in EEG signals utilizing Hilbert-Huang transform

Directory of Open Access Journals (Sweden)

Abdulhay Enas W

2011-05-01

Full Text Available Abstract Background Classification method capable of recognizing abnormal activities of the brain functionality are either brain imaging or brain signal analysis. The abnormal activity of interest in this study is characterized by a disturbance caused by changes in neuronal electrochemical activity that results in abnormal synchronous discharges. The method aims at helping physicians discriminate between healthy and seizure electroencephalographic (EEG signals. Method Discrimination in this work is achieved by analyzing EEG signals obtained from freely accessible databases. MATLAB has been used to implement and test the proposed classification algorithm. The analysis in question presents a classification of normal and ictal activities using a feature relied on Hilbert-Huang Transform. Through this method, information related to the intrinsic functions contained in the EEG signal has been extracted to track the local amplitude and the frequency of the signal. Based on this local information, weighted frequencies are calculated and a comparison between ictal and seizure-free determinant intrinsic functions is then performed. Methods of comparison used are the t-test and the Euclidean clustering. Results The t-test results in a P-value Conclusion An original tool for EEG signal processing giving physicians the possibility to diagnose brain functionality abnormalities is presented in this paper. The proposed system bears the potential of providing several credible benefits such as fast diagnosis, high accuracy, good sensitivity and specificity, time saving and user friendly. Furthermore, the classification of mode mixing can be achieved using the extracted instantaneous information of every IMF, but it would be most likely a hard task if only the average value is used. Extra benefits of this proposed system include low cost, and ease of interface. All of that indicate the usefulness of the tool and its use as an efficient diagnostic tool.

Application of the Fokker-Planck molecular mixing model to turbulent scalar mixing using moment methods

Science.gov (United States)

Madadi-Kandjani, E.; Fox, R. O.; Passalacqua, A.

2017-06-01

An extended quadrature method of moments using the β kernel density function (β -EQMOM) is used to approximate solutions to the evolution equation for univariate and bivariate composition probability distribution functions (PDFs) of a passive scalar for binary and ternary mixing. The key element of interest is the molecular mixing term, which is described using the Fokker-Planck (FP) molecular mixing model. The direct numerical simulations (DNSs) of Eswaran and Pope ["Direct numerical simulations of the turbulent mixing of a passive scalar," Phys. Fluids 31, 506 (1988)] and the amplitude mapping closure (AMC) of Pope ["Mapping closures for turbulent mixing and reaction," Theor. Comput. Fluid Dyn. 2, 255 (1991)] are taken as reference solutions to establish the accuracy of the FP model in the case of binary mixing. The DNSs of Juneja and Pope ["A DNS study of turbulent mixing of two passive scalars," Phys. Fluids 8, 2161 (1996)] are used to validate the results obtained for ternary mixing. Simulations are performed with both the conditional scalar dissipation rate (CSDR) proposed by Fox [Computational Methods for Turbulent Reacting Flows (Cambridge University Press, 2003)] and the CSDR from AMC, with the scalar dissipation rate provided as input and obtained from the DNS. Using scalar moments up to fourth order, the ability of the FP model to capture the evolution of the shape of the PDF, important in turbulent mixing problems, is demonstrated. Compared to the widely used assumed β -PDF model [S. S. Girimaji, "Assumed β-pdf model for turbulent mixing: Validation and extension to multiple scalar mixing," Combust. Sci. Technol. 78, 177 (1991)], the β -EQMOM solution to the FP model more accurately describes the initial mixing process with a relatively small increase in computational cost.

Testing and evaluation of alternative process systems for immobilizing radioactive mixed particulate waste in cement

International Nuclear Information System (INIS)

Weingardt, K.M.; Weber, J.R.

1994-03-01

Radioactive and Hazardous Mixed Wastes have accumulated at the Department of Energy (DOE) Hanford Site in south-central Washington State. Ongoing operations and planned facilities at Hanford will also contribute to this waste stream. To meet the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions most of this waste will need to be treated to permit disposal. In general this treatment will need to include stabilization/solidification either as a sole method or as part of a treatment train. A planned DOE facility, the Waste Receiving and Processing (WRAP) Module 2A, is scoped to provide this required treatment for containerized contact-handled (CH), mixed low-level waste (MLLW) at Hanford. An engineering development program has been conducted by Westinghouse Hanford Company (WHC) to select the best system for utilizing a cement based process in WRAP Module 2A. Three mixing processes were developed for analysis and testing; in-drum mixing, continuous mixing, and batch mixing. Some full scale tests were conducted and 55 gallon drums of solidified product were produced. These drums were core sampled and examined to evaluate mixing effectiveness. Total solids loading and the order of addition of waste and binder constituents were also varied. The highest confidence approach to meet the WRAP Module 2A waste immobilization system needs appears to be the out-of-drum batch mixing concept. This system is believed to offer the most flexibility and efficiency, given the highly variable and troublesome waste streams feeding the facility

A METHOD USING GNSS LH-REFLECTED SIGNALS FOR SOIL ROUGHNESS ESTIMATION

Directory of Open Access Journals (Sweden)

Y. Jia

2018-04-01

Full Text Available Global Navigation Satellite System Reflectometry (GNSS-R is based on the concept of receiving GPS signals reflected by the ground using a passive receiver. The receiver can be on the ground or installed on a small aircraft or UAV and collects the electromagnetic field scattered from the surface of the Earth. The received signals are then analyzed to determine the characteristics of the surface. Many research has been reported showing the capability of the GNSS-R technique. However, the roughness of the surface impacts the phase and amplitude of the received signals, which is still a worthwhile study. This paper presented a method can be used by GNSS-R to estimate the surface roughness. First, the data was calculated in the specular reflection with the assumption of a flat surface with different permittivity. Since the power reflectivity can be evaluated as the ratio of left-hand (LH reflected signal to the direct right-hand (RH signal. Then a semi-empirical roughness model was applied to the data for testing. The results showed the method can distinguish the water and the soil surface. The sensitivity of the parameters was also analyzed. It indicates this method for soil roughness estimation can be used by GNSS-R LH reflected signals. In the next step, several experiments need to be done for improving the model and exploring the way of the estimation.

a Method Using Gnss Lh-Reflected Signals for Soil Roughness Estimation

Science.gov (United States)

Jia, Y.; Li, W.; Chen, Y.; Lv, H.; Pei, Y.

2018-04-01

Global Navigation Satellite System Reflectometry (GNSS-R) is based on the concept of receiving GPS signals reflected by the ground using a passive receiver. The receiver can be on the ground or installed on a small aircraft or UAV and collects the electromagnetic field scattered from the surface of the Earth. The received signals are then analyzed to determine the characteristics of the surface. Many research has been reported showing the capability of the GNSS-R technique. However, the roughness of the surface impacts the phase and amplitude of the received signals, which is still a worthwhile study. This paper presented a method can be used by GNSS-R to estimate the surface roughness. First, the data was calculated in the specular reflection with the assumption of a flat surface with different permittivity. Since the power reflectivity can be evaluated as the ratio of left-hand (LH) reflected signal to the direct right-hand (RH) signal. Then a semi-empirical roughness model was applied to the data for testing. The results showed the method can distinguish the water and the soil surface. The sensitivity of the parameters was also analyzed. It indicates this method for soil roughness estimation can be used by GNSS-R LH reflected signals. In the next step, several experiments need to be done for improving the model and exploring the way of the estimation.

Fecal electrolyte testing for evaluation of unexplained diarrhea: Validation of body fluid test accuracy in the absence of a reference method.

Science.gov (United States)

Voskoboev, Nikolay V; Cambern, Sarah J; Hanley, Matthew M; Giesen, Callen D; Schilling, Jason J; Jannetto, Paul J; Lieske, John C; Block, Darci R

2015-11-01

Validation of tests performed on body fluids other than blood or urine can be challenging due to the lack of a reference method to confirm accuracy. The aim of this study was to evaluate alternate assessments of accuracy that laboratories can rely on to validate body fluid tests in the absence of a reference method using the example of sodium (Na(+)), potassium (K(+)), and magnesium (Mg(2+)) testing in stool fluid. Validations of fecal Na(+), K(+), and Mg(2+) were performed on the Roche cobas 6000 c501 (Roche Diagnostics) using residual stool specimens submitted for clinical testing. Spiked recovery, mixing studies, and serial dilutions were performed and % recovery of each analyte was calculated to assess accuracy. Results were confirmed by comparison to a reference method (ICP-OES, PerkinElmer). Mean recoveries for fecal electrolytes were Na(+) upon spiking=92%, mixing=104%, and dilution=105%; K(+) upon spiking=94%, mixing=96%, and dilution=100%; and Mg(2+) upon spiking=93%, mixing=98%, and dilution=100%. When autoanalyzer results were compared to reference ICP-OES results, Na(+) had a slope=0.94, intercept=4.1, and R(2)=0.99; K(+) had a slope=0.99, intercept=0.7, and R(2)=0.99; and Mg(2+) had a slope=0.91, intercept=-4.6, and R(2)=0.91. Calculated osmotic gap using both methods were highly correlated with slope=0.95, intercept=4.5, and R(2)=0.97. Acid pretreatment increased magnesium recovery from a subset of clinical specimens. A combination of mixing, spiking, and dilution recovery experiments are an acceptable surrogate for assessing accuracy in body fluid validations in the absence of a reference method. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Mixed methods in gerontological research: Do the qualitative and quantitative data “touch”?

Science.gov (United States)

Happ, Mary Beth

2010-01-01

This paper distinguishes between parallel and integrated mixed methods research approaches. Barriers to integrated mixed methods approaches in gerontological research are discussed and critiqued. The author presents examples of mixed methods gerontological research to illustrate approaches to data integration at the levels of data analysis, interpretation, and research reporting. As a summary of the methodological literature, four basic levels of mixed methods data combination are proposed. Opportunities for mixing qualitative and quantitative data are explored using contemporary examples from published studies. Data transformation and visual display, judiciously applied, are proposed as pathways to fuller mixed methods data integration and analysis. Finally, practical strategies for mixing qualitative and quantitative data types are explicated as gerontological research moves beyond parallel mixed methods approaches to achieve data integration. PMID:20077973

Structural issues affecting mixed methods studies in health research: a qualitative study.

Science.gov (United States)

O'Cathain, Alicia; Nicholl, Jon; Murphy, Elizabeth

2009-12-09

Health researchers undertake studies which combine qualitative and quantitative methods. Little attention has been paid to the structural issues affecting this mixed methods approach. We explored the facilitators and barriers to undertaking mixed methods studies in health research. Face-to-face semi-structured interviews with 20 researchers experienced in mixed methods research in health in the United Kingdom. Structural facilitators for undertaking mixed methods studies included a perception that funding bodies promoted this approach, and the multidisciplinary constituency of some university departments. Structural barriers to exploiting the potential of these studies included a lack of education and training in mixed methods research, and a lack of templates for reporting mixed methods articles in peer-reviewed journals. The 'hierarchy of evidence' relating to effectiveness studies in health care research, with the randomised controlled trial as the gold standard, appeared to pervade the health research infrastructure. Thus integration of data and findings from qualitative and quantitative components of mixed methods studies, and dissemination of integrated outputs, tended to occur through serendipity and effort, further highlighting the presence of structural constraints. Researchers are agents who may also support current structures - journal reviewers and editors, and directors of postgraduate training courses - and thus have the ability to improve the structural support for exploiting the potential of mixed methods research. The environment for health research in the UK appears to be conducive to mixed methods research but not to exploiting the potential of this approach. Structural change, as well as change in researcher behaviour, will be necessary if researchers are to fully exploit the potential of using mixed methods research.

System and method for traffic signal timing estimation

KAUST Repository

Dumazert, Julien; Claudel, Christian G.

2015-01-01

A method and system for estimating traffic signals. The method and system can include constructing trajectories of probe vehicles from GPS data emitted by the probe vehicles, estimating traffic signal cycles, combining the estimates, and computing the traffic signal timing by maximizing a scoring function based on the estimates. Estimating traffic signal cycles can be based on transition times of the probe vehicles starting after a traffic signal turns green.

System and method for traffic signal timing estimation

KAUST Repository

Dumazert, Julien

2015-12-30

A method and system for estimating traffic signals. The method and system can include constructing trajectories of probe vehicles from GPS data emitted by the probe vehicles, estimating traffic signal cycles, combining the estimates, and computing the traffic signal timing by maximizing a scoring function based on the estimates. Estimating traffic signal cycles can be based on transition times of the probe vehicles starting after a traffic signal turns green.

A Mixed Methods Portrait of Urban Instrumental Music Teaching

Science.gov (United States)

Fitzpatrick, Kate R.

2011-01-01

The purpose of this mixed methods study was to learn about the ways that instrumental music teachers in Chicago navigated the urban landscape. The design of the study most closely resembles Creswell and Plano Clark's (2007) two-part Triangulation Convergence Mixed Methods Design, with the addition of an initial exploratory focus group component.…

Method of Menu Selection by Gaze Movement Using AC EOG Signals

Science.gov (United States)

Kanoh, Shin'ichiro; Futami, Ryoko; Yoshinobu, Tatsuo; Hoshimiya, Nozomu

A method to detect the direction and the distance of voluntary eye gaze movement from EOG (electrooculogram) signals was proposed and tested. In this method, AC-amplified vertical and horizontal transient EOG signals were classified into 8-class directions and 2-class distances of voluntary eye gaze movements. A horizontal and a vertical EOGs during eye gaze movement at each sampling time were treated as a two-dimensional vector, and the center of gravity of the sample vectors whose norms were more than 80% of the maximum norm was used as a feature vector to be classified. By the classification using the k-nearest neighbor algorithm, it was shown that the averaged correct detection rates on each subject were 98.9%, 98.7%, 94.4%, respectively. This method can avoid strict EOG-based eye tracking which requires DC amplification of very small signal. It would be useful to develop robust human interfacing systems based on menu selection for severely paralyzed patients.

Design and implementation of a reconfigurable mixed-signal SoC based on field programmable analog arrays

Science.gov (United States)

Liu, Lintao; Gao, Yuhan; Deng, Jun

2017-11-01

This work presents a reconfigurable mixed-signal system-on-chip (SoC), which integrates switched-capacitor-based field programmable analog arrays (FPAA), analog-to-digital converter (ADC), digital-to-analog converter, digital down converter , digital up converter, 32-bit reduced instruction-set computer central processing unit (CPU) and other digital IPs on a single chip with 0.18 μm CMOS technology. The FPAA intellectual property could be reconfigured as different function circuits, such as gain amplifier, divider, sine generator, and so on. This single-chip integrated mixed-signal system is a complete modern signal processing system, occupying a die area of 7 × 8 mm 2 and consuming 719 mW with a clock frequency of 150 MHz for CPU and 200 MHz for ADC/DAC. This SoC chip can help customers to shorten design cycles, save board area, reduce the system power consumption and depress the system integration risk, which would afford a big prospect of application for wireless communication. Project supported by the National High Technology and Development Program of China (No. 2012AA012303).

On Self-Adaptive Method for General Mixed Variational Inequalities

Directory of Open Access Journals (Sweden)

Abdellah Bnouhachem

2008-01-01

Full Text Available We suggest and analyze a new self-adaptive method for solving general mixed variational inequalities, which can be viewed as an improvement of the method of (Noor 2003. Global convergence of the new method is proved under the same assumptions as Noor's method. Some preliminary computational results are given to illustrate the efficiency of the proposed method. Since the general mixed variational inequalities include general variational inequalities, quasivariational inequalities, and nonlinear (implicit complementarity problems as special cases, results proved in this paper continue to hold for these problems.

CAMAC based Test Signal Generator using Re-configurable device

International Nuclear Information System (INIS)

Sharma, Atish; Raval, Tushar; Srivastava, Amit K; Reddy, D Chenna

2010-01-01

There are many different types of signal generators, with different purposes and applications (and at varying levels of expense). In general, no device is suitable for all possible applications. Hence the selection of signal generator is as per requirements. For SST-1 Data Acquisition System requirements, we have developed a CAMAC based Test Signal Generator module using Re-configurable device (CPLD). This module is based on CAMAC interface but can be used for testing both CAMAC and PXI Data Acquisition Systems in SST-1 tokamak. It can also be used for other similar applications. Unlike traditional signal generators, which are embedded hardware, it is a flexible hardware unit, programmable through Graphical User Interface (GUI) developed in LabVIEW application development tool. The main aim of this work is to develop a signal generator for testing our data acquisition interface for a large number of channels simultaneously. The module front panel has various connectors like LEMO and D type connectors for signal interface. The module can be operated either in continuous signal generation mode or in triggered mode depending upon application. This can be done either by front panel switch or through CAMAC software commands (for remote operation). Similarly module reset and trigger generation operation can be performed either through front panel push button switch or through software CAMAC commands. The module has the facility to accept external TTL level trigger and clock through LEMO connectors. The module can also generate trigger and the clock signal, which can be delivered to other devices through LEMO connectors. The module generates two types of signals: Analog and digital (TTL level). The analog output (single channel) is generated from Digital to Analog Converter through CPLD for various types of waveforms like Sine, Square, Triangular and other wave shape that can vary in amplitude as well as in frequency. The module is quite useful to test up to 32 channels

Adaptative mixed methods to axisymmetric shells

International Nuclear Information System (INIS)

Malta, S.M.C.; Loula, A.F.D.; Garcia, E.L.M.

1989-09-01

The mixed Petrov-Galerkin method is applied to axisymmetric shells with uniform and non uniform meshes. Numerical experiments with a cylindrical shell showed a significant improvement in convergence and accuracy with adaptive meshes. (A.C.A.S.) [pt

Nurse educators' critical thinking: A mixed methods exploration.

Science.gov (United States)

Raymond, Christy; Profetto-McGrath, Joanne; Myrick, Florence; Strean, William B

2018-07-01

Nurse educator's critical thinking remains unexamined as a key factor in the development of students' critical thinking. The objective of this study is to understand how nurse educators reveal their critical thinking in the clinical setting while supervising students. This study uses a single-phase triangulation mixed methods design with multiple data gathering techniques. Participants for this study are clinical nurse educators from a large Western Canadian baccalaureate nursing program who teach 2nd or 3rd year students in medical-surgical settings. Participants for this study completed a demographic survey, the California Critical Thinking Skills Test (CCTST), the California Critical Thinking Disposition Inventory (CCTDI), participant observation in a clinical practice setting, and semi-structured interviews. The results from the California Critical Thinking assessments (CCTST and CCTDI) show that participants are positively inclined and have a moderate to strong ability to think critically, similar to other studies. Participants find it difficult to describe how they reveal their critical thinking in the clinical setting, yet all participants use role modeling and questioning to share their critical thinking with students. When the quantitative and qualitative results are compared, it is apparent that the confidence in reasoning subscale of the California Critical Thinking Skills Test is higher in those educators who more frequently demonstrate and voice engagement in reflective activities. Dispositions associated with critical thinking, as measured by the California Critical Thinking Disposition Inventory, are more easily observed compared to critical thinking skills. This study is a beginning exploration of nurse educators' critical thinking-in-action. Our mixed methods approach uncovers a valuable approach to understanding the complexity of nurse educators' critical thinking. Further study is needed to uncover how nurse educators' can specifically enact

Improved method for SNR prediction in machine-learning-based test

NARCIS (Netherlands)

Sheng, Xiaoqin; Kerkhoff, Hans G.

2010-01-01

This paper applies an improved method for testing the signal-to-noise ratio (SNR) of Analogue-to-Digital Converters (ADC). In previous work, a noisy and nonlinear pulse signal is exploited as the input stimulus to obtain the signature results of ADC. By applying a machine-learning-based approach,

On the optimization of a mixed speaker array in an enclosed space using the virtual-speaker weighting method

Science.gov (United States)

Peng, Bo; Zheng, Sifa; Liao, Xiangning; Lian, Xiaomin

2018-03-01

In order to achieve sound field reproduction in a wide frequency band, multiple-type speakers are used. The reproduction accuracy is not only affected by the signals sent to the speakers, but also depends on the position and the number of each type of speaker. The method of optimizing a mixed speaker array is investigated in this paper. A virtual-speaker weighting method is proposed to optimize both the position and the number of each type of speaker. In this method, a virtual-speaker model is proposed to quantify the increment of controllability of the speaker array when the speaker number increases. While optimizing a mixed speaker array, the gain of the virtual-speaker transfer function is used to determine the priority orders of the candidate speaker positions, which optimizes the position of each type of speaker. Then the relative gain of the virtual-speaker transfer function is used to determine whether the speakers are redundant, which optimizes the number of each type of speaker. Finally the virtual-speaker weighting method is verified by reproduction experiments of the interior sound field in a passenger car. The results validate that the optimum mixed speaker array can be obtained using the proposed method.

Extending existing structural identifiability analysis methods to mixed-effects models.

Science.gov (United States)

Janzén, David L I; Jirstrand, Mats; Chappell, Michael J; Evans, Neil D

2018-01-01

The concept of structural identifiability for state-space models is expanded to cover mixed-effects state-space models. Two methods applicable for the analytical study of the structural identifiability of mixed-effects models are presented. The two methods are based on previously established techniques for non-mixed-effects models; namely the Taylor series expansion and the input-output form approach. By generating an exhaustive summary, and by assuming an infinite number of subjects, functions of random variables can be derived which in turn determine the distribution of the system's observation function(s). By considering the uniqueness of the analytical statistical moments of the derived functions of the random variables, the structural identifiability of the corresponding mixed-effects model can be determined. The two methods are applied to a set of examples of mixed-effects models to illustrate how they work in practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Zero-inflated Poisson model based likelihood ratio test for drug safety signal detection.

Science.gov (United States)

Huang, Lan; Zheng, Dan; Zalkikar, Jyoti; Tiwari, Ram

2017-02-01

In recent decades, numerous methods have been developed for data mining of large drug safety databases, such as Food and Drug Administration's (FDA's) Adverse Event Reporting System, where data matrices are formed by drugs such as columns and adverse events as rows. Often, a large number of cells in these data matrices have zero cell counts and some of them are "true zeros" indicating that the drug-adverse event pairs cannot occur, and these zero counts are distinguished from the other zero counts that are modeled zero counts and simply indicate that the drug-adverse event pairs have not occurred yet or have not been reported yet. In this paper, a zero-inflated Poisson model based likelihood ratio test method is proposed to identify drug-adverse event pairs that have disproportionately high reporting rates, which are also called signals. The maximum likelihood estimates of the model parameters of zero-inflated Poisson model based likelihood ratio test are obtained using the expectation and maximization algorithm. The zero-inflated Poisson model based likelihood ratio test is also modified to handle the stratified analyses for binary and categorical covariates (e.g. gender and age) in the data. The proposed zero-inflated Poisson model based likelihood ratio test method is shown to asymptotically control the type I error and false discovery rate, and its finite sample performance for signal detection is evaluated through a simulation study. The simulation results show that the zero-inflated Poisson model based likelihood ratio test method performs similar to Poisson model based likelihood ratio test method when the estimated percentage of true zeros in the database is small. Both the zero-inflated Poisson model based likelihood ratio test and likelihood ratio test methods are applied to six selected drugs, from the 2006 to 2011 Adverse Event Reporting System database, with varying percentages of observed zero-count cells.

New mixed finite-element methods

International Nuclear Information System (INIS)

Franca, L.P.

1987-01-01

New finite-element methods are proposed for mixed variational formulations. The methods are constructed by adding to the classical Galerkin method various least-squares like terms. The additional terms involve integrals over element interiors, and include mesh-parameter dependent coefficients. The methods are designed to enhance stability. Consistency is achieved in the sense that exact solutions identically satisfy the variational equations.Applied to several problems, simple finite-element interpolations are rendered convergent, including convenient equal-order interpolations generally unstable within the Galerkin approach. The methods are subdivided into two classes according to the manner in which stability is attained: (1) circumventing Babuska-Brezzi condition methods; (2) satisfying Babuska-Brezzi condition methods. Convergence is established for each class of methods. Applications of the first class of methods to Stokes flow and compressible linear elasticity are presented. The second class of methods is applied to the Poisson, Timoshenko beam and incompressible elasticity problems. Numerical results demonstrate the good stability and accuracy of the methods, and confirm the error estimates

30 CFR 7.408 - Test for flame resistance of signaling cables.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of signaling cables..., Signaling Cables, and Cable Splice Kits § 7.408 Test for flame resistance of signaling cables. (a) Test... either and support and the center support. (6) After subjecting the test specimen to external flame for...

The effect of mixing method on tricalcium silicate-based cement.

Science.gov (United States)

Duque, J A; Fernandes, S L; Bubola, J P; Duarte, M A H; Camilleri, J; Marciano, M A

2018-01-01

To evaluate the effect of three methods of mixing on the physical and chemical properties of tricalcium silicate-based cements. The materials evaluated were MTA Angelus and Portland cement with 20% zirconium oxide (PC-20-Zr). The cements were mixed using a 3 : 1 powder-to-liquid ratio. The mixing methods were manual (m), trituration (tr) and ultrasonic (us) activation. The materials were characterized by means of scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy. Flowability was analysed according to ANSI/ADA 57/2012. Initial and final setting times were assessed following ASTM C266/08. Volume change was evaluated using a micro-CT volumetric method. Solubility was analysed according to ADA 57/2012. pH and calcium ion release were measured after 3, 24, 72 and 168 h. Statistical analysis was performed using two-way analysis of variance. The level of significance was set at P = 0.05. The SEM analysis revealed that ultrasonic activation was associated with a homogeneous distribution of particles. Flowability, volume change and initial setting time were not influenced by the mixing method (P > 0.05). Solubility was influenced by the mixing method (P < 0.05). For pH, at 168 h, significant differences were found between MTA-m and PC-20-Zr-m (P < 0.05). For calcium ion release, PC-20-Zr-tr had higher values than MTA-m at 3 h, and MTA-tr had higher values than PC-20-Zr-m at 168 h (P < 0.05). The ultrasonic and trituration methods led to higher calcium ion release and pH compared with manual mixing for all cements, whilst the ultrasonic method produced smaller particles for the PC-20-Zr cement. Flow, setting times and volume change were not influenced by the mixing method used; however, it did have an impact on solubility. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Source Signals Separation and Reconstruction Following Principal Component Analysis

Directory of Open Access Journals (Sweden)

WANG Cheng

2014-02-01

Full Text Available For separation and reconstruction of source signals from observed signals problem, the physical significance of blind source separation modal and independent component analysis is not very clear, and its solution is not unique. Aiming at these disadvantages, a new linear and instantaneous mixing model and a novel source signals separation reconstruction solving method from observed signals based on principal component analysis (PCA are put forward. Assumption of this new model is statistically unrelated rather than independent of source signals, which is different from the traditional blind source separation model. A one-to-one relationship between linear and instantaneous mixing matrix of new model and linear compound matrix of PCA, and a one-to-one relationship between unrelated source signals and principal components are demonstrated using the concept of linear separation matrix and unrelated of source signals. Based on this theoretical link, source signals separation and reconstruction problem is changed into PCA of observed signals then. The theoretical derivation and numerical simulation results show that, in despite of Gauss measurement noise, wave form and amplitude information of unrelated source signal can be separated and reconstructed by PCA when linear mixing matrix is column orthogonal and normalized; only wave form information of unrelated source signal can be separated and reconstructed by PCA when linear mixing matrix is column orthogonal but not normalized, unrelated source signal cannot be separated and reconstructed by PCA when mixing matrix is not column orthogonal or linear.

Demystifying Mixed Methods Research Design: A Review of the Literature

Science.gov (United States)

Caruth, Gail D.

2013-01-01

Mixed methods research evolved in response to the observed limitations of both quantitative and qualitative designs and is a more complex method. The purpose of this paper was to examine mixed methods research in an attempt to demystify the design thereby allowing those less familiar with its design an opportunity to utilize it in future research.…

Seizure classification in EEG signals utilizing Hilbert-Huang transform.

Science.gov (United States)

Oweis, Rami J; Abdulhay, Enas W

2011-05-24

Classification method capable of recognizing abnormal activities of the brain functionality are either brain imaging or brain signal analysis. The abnormal activity of interest in this study is characterized by a disturbance caused by changes in neuronal electrochemical activity that results in abnormal synchronous discharges. The method aims at helping physicians discriminate between healthy and seizure electroencephalographic (EEG) signals. Discrimination in this work is achieved by analyzing EEG signals obtained from freely accessible databases. MATLAB has been used to implement and test the proposed classification algorithm. The analysis in question presents a classification of normal and ictal activities using a feature relied on Hilbert-Huang Transform. Through this method, information related to the intrinsic functions contained in the EEG signal has been extracted to track the local amplitude and the frequency of the signal. Based on this local information, weighted frequencies are calculated and a comparison between ictal and seizure-free determinant intrinsic functions is then performed. Methods of comparison used are the t-test and the Euclidean clustering. The t-test results in a P-value with respect to its fast response and ease to use. An original tool for EEG signal processing giving physicians the possibility to diagnose brain functionality abnormalities is presented in this paper. The proposed system bears the potential of providing several credible benefits such as fast diagnosis, high accuracy, good sensitivity and specificity, time saving and user friendly. Furthermore, the classification of mode mixing can be achieved using the extracted instantaneous information of every IMF, but it would be most likely a hard task if only the average value is used. Extra benefits of this proposed system include low cost, and ease of interface. All of that indicate the usefulness of the tool and its use as an efficient diagnostic tool.

Full-Scale Turbofan Engine Noise-Source Separation Using a Four-Signal Method

Science.gov (United States)

Hultgren, Lennart S.; Arechiga, Rene O.

2016-01-01

Contributions from the combustor to the overall propulsion noise of civilian transport aircraft are starting to become important due to turbofan design trends and expected advances in mitigation of other noise sources. During on-ground, static-engine acoustic tests, combustor noise is generally sub-dominant to other engine noise sources because of the absence of in-flight effects. Consequently, noise-source separation techniques are needed to extract combustor-noise information from the total noise signature in order to further progress. A novel four-signal source-separation method is applied to data from a static, full-scale engine test and compared to previous methods. The new method is, in a sense, a combination of two- and three-signal techniques and represents an attempt to alleviate some of the weaknesses of each of those approaches. This work is supported by the NASA Advanced Air Vehicles Program, Advanced Air Transport Technology Project, Aircraft Noise Reduction Subproject and the NASA Glenn Faculty Fellowship Program.

Assessing and evaluating multidisciplinary translational teams: a mixed methods approach.

Science.gov (United States)

Wooten, Kevin C; Rose, Robert M; Ostir, Glenn V; Calhoun, William J; Ameredes, Bill T; Brasier, Allan R

2014-03-01

A case report illustrates how multidisciplinary translational teams can be assessed using outcome, process, and developmental types of evaluation using a mixed-methods approach. Types of evaluation appropriate for teams are considered in relation to relevant research questions and assessment methods. Logic models are applied to scientific projects and team development to inform choices between methods within a mixed-methods design. Use of an expert panel is reviewed, culminating in consensus ratings of 11 multidisciplinary teams and a final evaluation within a team-type taxonomy. Based on team maturation and scientific progress, teams were designated as (a) early in development, (b) traditional, (c) process focused, or (d) exemplary. Lessons learned from data reduction, use of mixed methods, and use of expert panels are explored.

New signals of quark-gluon-hadron mixed phase formation

Energy Technology Data Exchange (ETDEWEB)

Bugaev, K.A.; Sagun, V.V.; Ivanytskyi, A.I.; Zinovjev, G.M. [Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine); Oliinychenko, D.R. [Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine); Goethe University, FIAS, Frankfurt am Main (Germany); Ilgenfritz, E.M. [JINR, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation); Nikonov, E.G. [JINR, Laboratory for Information Technologies, Dubna (Russian Federation); Taranenko, A.V. [Moscow Engineering Physics Institute, National Research Nuclear University ' ' MEPhI' ' , Moscow (Russian Federation)

2016-08-15

Here we present several remarkable irregularities at chemical freeze-out which are found using an advanced version of the hadron resonance gas model. The most prominent of them are the sharp peak of the trace anomaly existing at chemical freeze-out at the center-of-mass energy 4.9 GeV and two sets of highly correlated quasi-plateaus in the collision energy dependence of the entropy per baryon, total pion number per baryon, and thermal pion number per baryon which we found at the center-of-mass energies 3.8-4.9 GeV and 7.6-10 GeV. The low-energy set of quasi-plateaus was predicted a long time ago. On the basis of the generalized shock-adiabat model we demonstrate that the low-energy correlated quasi-plateaus give evidence for the anomalous thermodynamic properties inside the quark-gluon-hadron mixed phase. It is also shown that the trace anomaly sharp peak at chemical freeze-out corresponds to the trace anomaly peak at the boundary between the mixed phase and quark gluon plasma. We argue that the high-energy correlated quasi-plateaus may correspond to a second phase transition and discuss its possible origin and location. Besides we suggest two new observables which may serve as clear signals of these phase transformations. (orig.)

Using mixed methods when researching communities.

Science.gov (United States)

Ochieng, Bertha M N; Meetoo, Danny

2015-09-01

To argue for the use of mixed methods when researching communities. Although research involving minority communities is now advanced, not enough effort has been made to formulate methodological linkages between qualitative and quantitative methods in most studies. For instance, the quantitative approaches used by epidemiologists and others in examining the wellbeing of communities are usually empirical. While the rationale for this is sound, quantitative findings can be expanded with data from in-depth qualitative approaches, such as interviews or observations, which are likely to provide insights into the experiences of people in those communities and their relationships with their wellbeing. Academic databases including The Cochrane Library, MEDLINE, CINAHL, AMED, INTERNURSE, Science Direct, Web of Knowledge and PubMed. An iterative process of identifying eligible literature was carried out by comprehensively searching electronic databases. Using mixed-methods approaches is likely to address any potential drawbacks of individual methods by exploiting the strengths of each at the various stages of research. Combining methods can provide additional ways of looking at a complex problem and improve the understanding of a community's experiences. However, it is important for researchers to use the different methods interactively during their research. The use of qualitative and quantitative methods is likely to enrich our understanding of the interrelationship between wellbeing and the experiences of communities. This should help researchers to explore socio-cultural factors and experiences of health and healthcare practice more effectively.

Nondestructive evaluation of warm mix asphalt through resonant column testing.

Science.gov (United States)

2014-02-01

Non-destructive testing has been used for decades to characterize engineering properties of hot-mix asphalt. Among such tests is the resonant column (RC) test, which is commonly used to characterize soil materials. The resonant column device at Penn ...

Properties Important To Mixing For WTP Large Scale Integrated Testing

International Nuclear Information System (INIS)

Koopman, D.; Martino, C.; Poirier, M.

2012-01-01

Large Scale Integrated Testing (LSIT) is being planned by Bechtel National, Inc. to address uncertainties in the full scale mixing performance of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. External review boards have raised questions regarding the overall representativeness of simulants used in previous mixing tests. Accordingly, WTP requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in LSIT. Among the first tasks assigned to SRNL was to develop a list of waste properties that matter to pulse-jet mixer (PJM) mixing of WTP tanks. This report satisfies Commitment 5.2.3.1 of the Department of Energy Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2010-2: physical properties important to mixing and scaling. In support of waste simulant development, the following two objectives are the focus of this report: (1) Assess physical and chemical properties important to the testing and development of mixing scaling relationships; (2) Identify the governing properties and associated ranges for LSIT to achieve the Newtonian and non-Newtonian test objectives. This includes the properties to support testing of sampling and heel management systems. The test objectives for LSIT relate to transfer and pump out of solid particles, prototypic integrated operations, sparger operation, PJM controllability, vessel level/density measurement accuracy, sampling, heel management, PJM restart, design and safety margin, Computational Fluid Dynamics (CFD) Verification and Validation (V and V) and comparison, performance testing and scaling, and high temperature operation. The slurry properties that are most important to Performance Testing and Scaling depend on the test objective and rheological classification of the slurry (i

PROPERTIES IMPORTANT TO MIXING FOR WTP LARGE SCALE INTEGRATED TESTING

Energy Technology Data Exchange (ETDEWEB)

Koopman, D.; Martino, C.; Poirier, M.

2012-04-26

Large Scale Integrated Testing (LSIT) is being planned by Bechtel National, Inc. to address uncertainties in the full scale mixing performance of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. External review boards have raised questions regarding the overall representativeness of simulants used in previous mixing tests. Accordingly, WTP requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in LSIT. Among the first tasks assigned to SRNL was to develop a list of waste properties that matter to pulse-jet mixer (PJM) mixing of WTP tanks. This report satisfies Commitment 5.2.3.1 of the Department of Energy Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2010-2: physical properties important to mixing and scaling. In support of waste simulant development, the following two objectives are the focus of this report: (1) Assess physical and chemical properties important to the testing and development of mixing scaling relationships; (2) Identify the governing properties and associated ranges for LSIT to achieve the Newtonian and non-Newtonian test objectives. This includes the properties to support testing of sampling and heel management systems. The test objectives for LSIT relate to transfer and pump out of solid particles, prototypic integrated operations, sparger operation, PJM controllability, vessel level/density measurement accuracy, sampling, heel management, PJM restart, design and safety margin, Computational Fluid Dynamics (CFD) Verification and Validation (V and V) and comparison, performance testing and scaling, and high temperature operation. The slurry properties that are most important to Performance Testing and Scaling depend on the test objective and rheological classification of the slurry (i

Clustering Methods with Qualitative Data: a Mixed-Methods Approach for Prevention Research with Small Samples.

Science.gov (United States)

Henry, David; Dymnicki, Allison B; Mohatt, Nathaniel; Allen, James; Kelly, James G

2015-10-01

Qualitative methods potentially add depth to prevention research but can produce large amounts of complex data even with small samples. Studies conducted with culturally distinct samples often produce voluminous qualitative data but may lack sufficient sample sizes for sophisticated quantitative analysis. Currently lacking in mixed-methods research are methods allowing for more fully integrating qualitative and quantitative analysis techniques. Cluster analysis can be applied to coded qualitative data to clarify the findings of prevention studies by aiding efforts to reveal such things as the motives of participants for their actions and the reasons behind counterintuitive findings. By clustering groups of participants with similar profiles of codes in a quantitative analysis, cluster analysis can serve as a key component in mixed-methods research. This article reports two studies. In the first study, we conduct simulations to test the accuracy of cluster assignment using three different clustering methods with binary data as produced when coding qualitative interviews. Results indicated that hierarchical clustering, K-means clustering, and latent class analysis produced similar levels of accuracy with binary data and that the accuracy of these methods did not decrease with samples as small as 50. Whereas the first study explores the feasibility of using common clustering methods with binary data, the second study provides a "real-world" example using data from a qualitative study of community leadership connected with a drug abuse prevention project. We discuss the implications of this approach for conducting prevention research, especially with small samples and culturally distinct communities.

Clustering Methods with Qualitative Data: A Mixed Methods Approach for Prevention Research with Small Samples

Science.gov (United States)

Henry, David; Dymnicki, Allison B.; Mohatt, Nathaniel; Allen, James; Kelly, James G.

2016-01-01

Qualitative methods potentially add depth to prevention research, but can produce large amounts of complex data even with small samples. Studies conducted with culturally distinct samples often produce voluminous qualitative data, but may lack sufficient sample sizes for sophisticated quantitative analysis. Currently lacking in mixed methods research are methods allowing for more fully integrating qualitative and quantitative analysis techniques. Cluster analysis can be applied to coded qualitative data to clarify the findings of prevention studies by aiding efforts to reveal such things as the motives of participants for their actions and the reasons behind counterintuitive findings. By clustering groups of participants with similar profiles of codes in a quantitative analysis, cluster analysis can serve as a key component in mixed methods research. This article reports two studies. In the first study, we conduct simulations to test the accuracy of cluster assignment using three different clustering methods with binary data as produced when coding qualitative interviews. Results indicated that hierarchical clustering, K-Means clustering, and latent class analysis produced similar levels of accuracy with binary data, and that the accuracy of these methods did not decrease with samples as small as 50. Whereas the first study explores the feasibility of using common clustering methods with binary data, the second study provides a “real-world” example using data from a qualitative study of community leadership connected with a drug abuse prevention project. We discuss the implications of this approach for conducting prevention research, especially with small samples and culturally distinct communities. PMID:25946969

Invisible nursing research: thoughts about mixed methods research and nursing practice.

Science.gov (United States)

Fawcett, Jacqueline

2015-04-01

In this this essay, the author addresses the close connection between mixed methods research and nursing practice. If the assertion that research and practice are parallel processes is accepted, then nursing practice may be considered "invisible mixed methods research," in that almost every encounter between a nurse and a patient involves collection and integration of qualitative (word) and quantitative (number) information that actually is single-case mixed methods research. © The Author(s) 2015.

Designing, Teaching, and Evaluating Two Complementary Mixed Methods Research Courses

Science.gov (United States)

Christ, Thomas W.

2009-01-01

Teaching mixed methods research is difficult. This longitudinal explanatory study examined how two classes were designed, taught, and evaluated. Curriculum, Research, and Teaching (EDCS-606) and Mixed Methods Research (EDCS-780) used a research proposal generation process to highlight the importance of the purpose, research question and…

The Structure of Mixed Method Studies in Educational Research: A Content Analysis

Science.gov (United States)

Bryant, Lauren H.

2011-01-01

Educational researchers are beginning to use mixed methods designs to answer complex research questions. This content analysis investigates the structure and use of mixed methods in educational research in order to work toward a more standardized presentation. I used a concurrent mixed methods approach to analyze 30 studies from three prominent…

Mixed-Methods Design in Biology Education Research: Approach and Uses.

Science.gov (United States)

Warfa, Abdi-Rizak M

Educational research often requires mixing different research methodologies to strengthen findings, better contextualize or explain results, or minimize the weaknesses of a single method. This article provides practical guidelines on how to conduct such research in biology education, with a focus on mixed-methods research (MMR) that uses both quantitative and qualitative inquiries. Specifically, the paper provides an overview of mixed-methods design typologies most relevant in biology education research. It also discusses common methodological issues that may arise in mixed-methods studies and ways to address them. The paper concludes with recommendations on how to report and write about MMR. © 2016 L. A.-R. M. Warfa. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Signal-noise separation based on self-similarity testing in 1D-timeseries data

Science.gov (United States)

Bourdin, Philippe A.

2015-08-01

The continuous improvement of the resolution delivered by modern instrumentation is a cost-intensive part of any new space- or ground-based observatory. Typically, scientists later reduce the resolution of the obtained raw-data, for example in the spatial, spectral, or temporal domain, in order to suppress the effects of noise in the measurements. In practice, only simple methods are used that just smear out the noise, instead of trying to remove it, so that the noise can nomore be seen. In high-precision 1D-timeseries data, this usually results in an unwanted quality-loss and corruption of power spectra at selected frequency ranges. Novel methods exist that are based on non-local averaging, which would conserve much of the initial resolution, but these methods are so far focusing on 2D or 3D data. We present here a method specialized for 1D-timeseries, e.g. as obtained by magnetic field measurements from the recently launched MMS satellites. To identify the noise, we use a self-similarity testing and non-local averaging method in order to separate different types of noise and signals, like the instrument noise, non-correlated fluctuations in the signal from heliospheric sources, and correlated fluctuations such as harmonic waves or shock fronts. In power spectra of test data, we are able to restore significant parts of a previously know signal from a noisy measurement. This method also works for high frequencies, where the background noise may have a larger contribution to the spectral power than the signal itself. We offer an easy-to-use software tools set, which enables scientists to use this novel technique on their own noisy data. This allows to use the maximum possible capacity of the instrumental hardware and helps to enhance the quality of the obtained scientific results.

Time reversal signal processing in acoustic emission testing

Czech Academy of Sciences Publication Activity Database

Převorovský, Zdeněk; Krofta, Josef; Kober, Jan; Dvořáková, Zuzana; Chlada, Milan; Dos Santos, S.

2014-01-01

Roč. 19, č. 12 (2014) ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] Institutional support: RVO:61388998 Keywords : acoustic emission (AE) * ultrasonic testing (UT) * signal processing * source location * time reversal acoustic s * acoustic emission * signal processing and transfer Subject RIV: BI - Acoustic s http://www.ndt.net/events/ECNDT2014/app/content/Slides/637_Prevorovsky.pdf

Combining Qualitative and Quantitative Approaches: Some Arguments for Mixed Methods Research

Science.gov (United States)

Lund, Thorleif

2012-01-01

One purpose of the present paper is to elaborate 4 general advantages of the mixed methods approach. Another purpose is to propose a 5-phase evaluation design, and to demonstrate its usefulness for mixed methods research. The account is limited to research on groups in need of treatment, i.e., vulnerable groups, and the advantages of mixed methods…

Effect of the Torrance Creative Thinking Test on Heart Rate Signal Features

Directory of Open Access Journals (Sweden)

Zakeri S.

2016-02-01

Full Text Available Aims: Showing a meta-cognitive aspect, creativity is related to higher mental processes such as thinking, intelligence, imagination, and information process. There are many studies on the physiological bases of creativity. The aim of this study was to investigate the effects of creative thinking on the heart rate signal. Materials & Methods: In this semi-experimental study, 52 medical engineering, electrical, and control students of Sahand University were studied in 2012. The subjects were selected via accessible sampling method. To assess the level of the students’ creative thinking, Torrance Tests of Creative Thinking (B form; figural was used. Before and during creative thinking test, heart signal in the rest position was recorded by 1000Hz sampling frequency. Data was analyzed using Wilcoxon non-parametric test.   Findings: There was an increase in the mean heart power amplitude during creative thinking than the rest position. However, passing time and conducting the last sessions of the creativity test, it showed a reduction. There was an increase in the heart rate in persons with high creativity than those with low creativity. In addition, based on the test scores, there was a higher creativity level in females and three-lingual persons than males and bi-lingual persons, respectively. There was an increase in the heart rate in females than males (p=0.0398. Nevertheless, there was no significant difference between three-lingual and bilingual persons (p>0.05.    Conclusion: Creative thinking results in an increase in the heart rate in persons with high creativity than persons with low creativity. Therefore, the creativity level can be detected via heart signal. 

The characterization of NMR signal for blood pressure monitoring system and its testing

Directory of Open Access Journals (Sweden)

Bambang Murdaka Eka Jati

2016-02-01

Full Text Available ABSTRACT A blood monitoring system based on NMR method has been designed on constructed. This set-up of equipment used magnetic permanent, radio frequency (RF, receiver coil (RC, function generator (FG, amplifier which included the filter, as well as the oscilloscope digital storage. The background of this research was based on the sensitivity of NMR signal. The signal must be separated from signals background. This method was done by adjusting the frequency on FG, which was connected to radio frequency (RF coil, on empty sample. Subsequently, NMR signal was received by RC, and that signal could be shown on oscilloscope at resonance condition. The true frequency on NMR signal was Larmor frequency, and the other was background. The two variables of this experiment were the position of RF coil and the location temperature (20 up to 30oC. In conclusion, the resonance frequency of NMR signal (as Larmor frequency was 4.7 MHz (at static magnetic field of 1,600 gauss and it could be separated from background signals (3.4 and 6.2 MHz, and that signal was almost constant to room temperature. The equipment was used for sample testing. It gave systole/diastole data of 110/70 mmHg (on sphygmomanometer that was similar to 17/9 mV (on NMR signal. ABSTRAK Telah dikembangkan alat pemantauan tekanan darah berdasar prinsip NMR.

Calculation of mixed mode stress intensity factors using an alternating method

International Nuclear Information System (INIS)

Sakai, Takayuki

1999-01-01

In this study, mixed mode stress intensity factors (K I and K II ) of a square plate with a notch were calculated using a finite element alternating method. The obtained results were compared with the ones by a finite element method, and it was shown that the finite element alternating method can accurately estimate mixed mode stress intensity factors. Then, using this finite element alternating method, mixed mode stress intensity factors were calculated as changing the size and position of the notch, and its simplified equations were proposed. (author)

Mixed-Methods Design in Biology Education Research: Approach and Uses

Science.gov (United States)

Warfa, Abdi-Rizak M.

2016-01-01

Educational research often requires mixing different research methodologies to strengthen findings, better contextualize or explain results, or minimize the weaknesses of a single method. This article provides practical guidelines on how to conduct such research in biology education, with a focus on mixed-methods research (MMR) that uses both…

Forgotten evidence: A mixed methods study of why sexual assault kits (SAKs) are not submitted for DNA forensic testing.

Science.gov (United States)

Campbell, Rebecca; Fehler-Cabral, Giannina; Bybee, Deborah; Shaw, Jessica

2017-10-01

Throughout the United States, hundreds of thousands of sexual assault kits (SAKs) (also termed "rape kits") have not been submitted by the police for forensic DNA testing. DNA evidence can help sexual assault investigations and prosecutions by identifying offenders, revealing serial offenders through DNA matches across cases, and exonerating those who have been wrongly accused. In this article, we describe a 5-year action research project conducted with 1 city that had large numbers of untested SAKs-Detroit, Michigan-and our examination into why thousands of rape kits in this city were never submitted for forensic DNA testing. This mixed methods study combined ethnographic observations and qualitative interviews to identify stakeholders' perspectives as to why rape kits were not routinely submitted for testing. Then, we quantitatively examined whether these factors may have affected police practices regarding SAK testing, as evidenced by predictable changes in SAK submission rates over time. Chronic resource scarcity only partially explained why the organizations that serve rape victims-the police, crime lab, prosecution, and victim advocacy-could not test all rape kits, investigate all reported sexual assaults, and support all rape survivors. SAK submission rates significantly increased once criminal justice professionals in this city had full access to the FBI DNA forensic database Combined DNA Index System (CODIS), but even then, most SAKs were still not submitted for DNA testing. Building crime laboratories' capacities for DNA testing and training police on the utility of forensic evidence and best practices in sexual assault investigations can help remedy, and possibly prevent, the problem of untested rape kits. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Spectrum Sensing Method Based on Signal Feature and Clustering Algorithm in Cognitive Wireless Multimedia Sensor Networks

Directory of Open Access Journals (Sweden)

Yongwei Zhang

2017-01-01

Full Text Available In order to solve the problem of difficulty in determining the threshold in spectrum sensing technologies based on the random matrix theory, a spectrum sensing method based on clustering algorithm and signal feature is proposed for Cognitive Wireless Multimedia Sensor Networks. Firstly, the wireless communication signal features are obtained according to the sampling signal covariance matrix. Then, the clustering algorithm is used to classify and test the signal features. Different signal features and clustering algorithms are compared in this paper. The experimental results show that the proposed method has better sensing performance.

A multiscale mortar multipoint flux mixed finite element method

KAUST Repository

Wheeler, Mary Fanett; Xue, Guangri; Yotov, Ivan

2012-01-01

In this paper, we develop a multiscale mortar multipoint flux mixed finite element method for second order elliptic problems. The equations in the coarse elements (or subdomains) are discretized on a fine grid scale by a multipoint flux mixed finite

Investigation of mixed saliva by optoelectronic methods

Science.gov (United States)

Savchenko, Ekaterina; Nepomnyashchaya, Elina; Baranov, Maksim; Velichko, Elena; Aksenov, Evgenii; Bogomaz, Tatyana

2018-04-01

At present, saliva and its properties are being actively studied. Human saliva is a unique biological material that has potential in clinical practice. A detailed analysis of the characteristics and properties of saliva is relevant for diagnostic purposes. In this paper, the properties and characteristics of saliva are studied using optoelectronic methods: dynamic light scattering, electrophoretic light scattering and optical microscopy. Mixed saliva from a healthy patient and patient with diabetes mellitus type 2 was used as an object of the study. The dynamics of the behavior of a healthy and patient with diabetes mellitus type 2 is visible according to the results obtained. All three methods confirm hypothesis of structural changes in mixed saliva in the disease of diabetes mellitus type 2.

Mixing Methods in Organizational Ethics and Organizational Innovativeness Research : Three Approaches to Mixed Methods Analysis

OpenAIRE

Riivari, Elina

2015-01-01

This chapter discusses three categories of mixed methods analysis techniques: variableoriented, case-oriented, and process/experience-oriented. All three categories combine qualitative and quantitative approaches to research methodology. The major differences among the categories are the focus of the study, available analysis techniques and timely aspect of the study. In variable-oriented analysis, the study focus is relationships between the research phenomena. In case-oriente...

Mixed-meal tolerance test versus glucagon stimulation test for the assessment of beta-cell function in therapeutic trials in type 1 diabetes

DEFF Research Database (Denmark)

Greenbaum, Carla J; Mandrup-Poulsen, Thomas; McGee, Paula Friedenberg

2008-01-01

OBJECTIVE: Beta-cell function in type 1 diabetes clinical trials is commonly measured by C-peptide response to a secretagogue in either a mixed-meal tolerance test (MMTT) or a glucagon stimulation test (GST). The Type 1 Diabetes TrialNet Research Group and the European C-peptide Trial (ECPT) Study...... Group conducted parallel randomized studies to compare the sensitivity, reproducibility, and tolerability of these procedures. RESEARCH DESIGN AND METHODS: In randomized sequences, 148 TrialNet subjects completed 549 tests with up to 2 MMTT and 2 GST tests on separate days, and 118 ECPT subjects...

A Novel Blind Source Separation Algorithm and Performance Analysis of Weak Signal against Strong Interference in Passive Radar Systems

Directory of Open Access Journals (Sweden)

Chengjie Li

2016-01-01

Full Text Available In Passive Radar System, obtaining the mixed weak object signal against the super power signal (jamming is still a challenging task. In this paper, a novel framework based on Passive Radar System is designed for weak object signal separation. Firstly, we propose an Interference Cancellation algorithm (IC-algorithm to extract the mixed weak object signals from the strong jamming. Then, an improved FastICA algorithm with K-means cluster is designed to separate each weak signal from the mixed weak object signals. At last, we discuss the performance of the proposed method and verify the novel method based on several simulations. The experimental results demonstrate the effectiveness of the proposed method.

Triangulation, Respondent Validation, and Democratic Participation in Mixed Methods Research

Science.gov (United States)

Torrance, Harry

2012-01-01

Over the past 10 years or so the "Field" of "Mixed Methods Research" (MMR) has increasingly been exerting itself as something separate, novel, and significant, with some advocates claiming paradigmatic status. Triangulation is an important component of mixed methods designs. Triangulation has its origins in attempts to validate research findings…

Coarse-mesh method for multidimensional, mixed-lattice diffusion calculations

International Nuclear Information System (INIS)

Dodds, H.L. Jr.; Honeck, H.C.; Hostetler, D.E.

1977-01-01

A coarse-mesh finite difference method has been developed for multidimensional, mixed-lattice reactor diffusion calculations, both statics and kinetics, in hexagonal geometry. Results obtained with the coarse-mesh (CM) method have been compared with a conventional mesh-centered finite difference method and with experiment. The results of this comparison indicate that the accuracy of the CM method for highly heterogeneous (mixed) lattices using one point per hexagonal mesh element (''hex'') is about the same as the conventional method with six points per hex. Furthermore, the computing costs (i.e., central processor unit time and core storage requirements) of the CM method with one point per hex are about the same as the conventional method with one point per hex

The role of mixed methods in improved cookstove research.

Science.gov (United States)

Stanistreet, Debbi; Hyseni, Lirije; Bashin, Michelle; Sadumah, Ibrahim; Pope, Daniel; Sage, Michael; Bruce, Nigel

2015-01-01

The challenge of promoting access to clean and efficient household energy for cooking and heating is a critical issue facing low- and middle-income countries today. Along with clean fuels, improved cookstoves (ICSs) continue to play an important part in efforts to reduce the 4 million annual premature deaths attributed to household air pollution. Although a range of ICSs are available, there is little empirical evidence on appropriate behavior change approaches to inform adoption and sustained used at scale. Specifically, evaluations using either quantitative or qualitative methods provide an incomplete picture of the challenges in facilitating ICS adoption. This article examines how studies that use the strengths of both these approaches can offer important insights into behavior change in relation to ICS uptake and scale-up. Epistemological approaches, study design frameworks, methods of data collection, analytical approaches, and issues of validity and reliability in the context of mixed methods ICS research are examined, and the article presents an example study design from an evaluation study in Kenya incorporating a nested approach and a convergent case oriented design. The authors discuss the benefits and methodological challenges of mixed-methods approaches in the context of researching behavior change and ICS use recognizing that such methods represent relatively uncharted territory. The authors propose that more published examples are needed to provide frameworks for other researchers seeking to apply mixed methods in this context and suggest a comprehensive research agenda is required that incorporates integrated mixed-methods approaches, to provide best evidence for future scale-up.

Frequency-domain method for separating signal and noise

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

A new method for separation of signal and noise (SSN) is put forward. Frequency is redefined according to the features of signal and its derivative in the sampl ing time interval, thus double orthogonal basis (DOB) is constructed so that a signal can be precisely signified with a linear combination of low-frequency DOB . Under joint consideration in time domain (TD) and frequency domain (FD), a method on SSN with high accuracy is derived and a matched algorithm is designed and analyzed. This method is applicable to SSN in multiple frequency bands, and convenient in applying signal characteristics in TD and FD synthetically with highe raccuracy.

Frequency-domain method for separating signal and noise

Institute of Scientific and Technical Information of China (English)

王正明; 段晓君

2000-01-01

A new method for separation of signal and noise (SSN) is put forward. Frequency is redefined according to the features of signal and its derivative in the sampling time interval, thus double orthogonal basis (DOB) is constructed so that a signal can be precisely signified with a linear combination of low-frequency DOB. Under joint consideration in time domain (TD) and frequency domain (FD), a method on SSN with high accuracy is derived and a matched algorithm is designed and analyzed. This method is applicable to SSN in multiple frequency bands, and convenient in applying signal characteristics in TD and FD synthetically with higher accuracy.

A variational EM method for pole-zero modeling of speech with mixed block sparse and Gaussian excitation

DEFF Research Database (Denmark)

Shi, Liming; Nielsen, Jesper Kjær; Jensen, Jesper Rindom

2017-01-01

The modeling of speech can be used for speech synthesis and speech recognition. We present a speech analysis method based on pole-zero modeling of speech with mixed block sparse and Gaussian excitation. By using a pole-zero model, instead of the all-pole model, a better spectral fitting can...... be expected. Moreover, motivated by the block sparse glottal flow excitation during voiced speech and the white noise excitation for unvoiced speech, we model the excitation sequence as a combination of block sparse signals and white noise. A variational EM (VEM) method is proposed for estimating...... in reconstructing of the block sparse excitation....

Relevance of positive patch-test reactions to fragrance mix.

Science.gov (United States)

Devos, Steven A; Constandt, Lieve; Tupker, Ron A; Noz, Kathy C; Lucker, Georges P H; Bruynzeel, Derk P; Schuttelaar, Marie-Louise A; Kruyswijk, Mente R J; van Zuuren, Esther J; Vink, Jaqueline; Coenraads, Pieter-Jan; Kiemeney, Lambertus A L M; van der Valk, Pieter G M

2008-01-01

Fragrances are an important cause of allergic contact dermatitis. We presume that the traditional fragrance mix (FM) detects 70 to 80% of fragrance-allergic patients. FM has an irritant potential. Weak positive reactions may have a greater chance of being irrelevant than strong reactions. To improve the appraisal of FM patch-test reactions, we studied the relevance of reactions of different strength. We also studied the predictive value of the following on the relevance of the initial FM patch-test results: patch-test results of a repeated FM test; results of patch tests with balsam of Peru, colophony, and ingredients of the mix; and (history of) atopic dermatitis. One hundred thirty-eight patients who had doubtful positive (?+) or positive (+ to +++) reactions were included in the study. We determined relevance by history taking, location and course of the dermatitis, and additional patch testing. Patients were retested with FM and with each ingredient separately. The relevance of reactions to FM increases with the strength of the reactions. Predictors of relevance are the results of retesting with FM, the results of tests with the ingredients, and a history and/or present symptoms of atopic dermatitis. Retesting with FM and its ingredients may add to the benefit of patch testing.

Acceptability of self-collection sampling for HPV-DNA testing in low-resource settings: a mixed methods approach.

Science.gov (United States)

Bansil, Pooja; Wittet, Scott; Lim, Jeanette L; Winkler, Jennifer L; Paul, Proma; Jeronimo, Jose

2014-06-12

Vaginal self-sampling with HPV-DNA tests is a promising primary screening method for cervical cancer. However, women's experiences, concerns and the acceptability of such tests in low-resource settings remain unknown. In India, Nicaragua, and Uganda, a mixed-method design was used to collect data from surveys (N = 3,863), qualitative interviews (N = 72; 20 providers and 52 women) and focus groups (N = 30 women) on women's and providers' experiences with self-sampling, women's opinions of sampling at home, and their future needs. Among surveyed women, 90% provided a self- collected sample. Of these, 75% reported it was easy, although 52% were initially concerned about hurting themselves and 24% were worried about not getting a good sample. Most surveyed women preferred self-sampling (78%). However it was not clear if they responded to the privacy of self-sampling or the convenience of avoiding a pelvic examination, or both. In follow-up interviews, most women reported that they didn't mind self-sampling, but many preferred to have a provider collect the vaginal sample. Most women also preferred clinic-based screening (as opposed to home-based self-sampling), because the sample could be collected by a provider, women could receive treatment if needed, and the clinic was sanitary and provided privacy. Self-sampling acceptability was higher when providers prepared women through education, allowed women to examine the collection brush, and were present during the self-collection process. Among survey respondents, aids that would facilitate self-sampling in the future were: staff help (53%), additional images in the illustrated instructions (31%), and a chance to practice beforehand with a doll/model (26%). Self-and vaginal-sampling are widely acceptable among women in low-resource settings. Providers have a unique opportunity to educate and prepare women for self-sampling and be flexible in accommodating women's preference for self-sampling.

An improved EMD method for modal identification and a combined static-dynamic method for damage detection

Science.gov (United States)

Yang, Jinping; Li, Peizhen; Yang, Youfa; Xu, Dian

2018-04-01

Empirical mode decomposition (EMD) is a highly adaptable signal processing method. However, the EMD approach has certain drawbacks, including distortions from end effects and mode mixing. In the present study, these two problems are addressed using an end extension method based on the support vector regression machine (SVRM) and a modal decomposition method based on the characteristics of the Hilbert transform. The algorithm includes two steps: using the SVRM, the time series data are extended at both endpoints to reduce the end effects, and then, a modified EMD method using the characteristics of the Hilbert transform is performed on the resulting signal to reduce mode mixing. A new combined static-dynamic method for identifying structural damage is presented. This method combines the static and dynamic information in an equilibrium equation that can be solved using the Moore-Penrose generalized matrix inverse. The combination method uses the differences in displacements of the structure with and without damage and variations in the modal force vector. Tests on a four-story, steel-frame structure were conducted to obtain static and dynamic responses of the structure. The modal parameters are identified using data from the dynamic tests and improved EMD method. The new method is shown to be more accurate and effective than the traditional EMD method. Through tests with a shear-type test frame, the higher performance of the proposed static-dynamic damage detection approach, which can detect both single and multiple damage locations and the degree of the damage, is demonstrated. For structures with multiple damage, the combined approach is more effective than either the static or dynamic method. The proposed EMD method and static-dynamic damage detection method offer improved modal identification and damage detection, respectively, in structures.

An adaptive segment method for smoothing lidar signal based on noise estimation

Science.gov (United States)

Wang, Yuzhao; Luo, Pingping

2014-10-01

An adaptive segmentation smoothing method (ASSM) is introduced in the paper to smooth the signal and suppress the noise. In the ASSM, the noise is defined as the 3σ of the background signal. An integer number N is defined for finding the changing positions in the signal curve. If the difference of adjacent two points is greater than 3Nσ, the position is recorded as an end point of the smoothing segment. All the end points detected as above are recorded and the curves between them will be smoothed separately. In the traditional method, the end points of the smoothing windows in the signals are fixed. The ASSM creates changing end points in different signals and the smoothing windows could be set adaptively. The windows are always set as the half of the segmentations and then the average smoothing method will be applied in the segmentations. The Iterative process is required for reducing the end-point aberration effect in the average smoothing method and two or three times are enough. In ASSM, the signals are smoothed in the spacial area nor frequent area, that means the frequent disturbance will be avoided. A lidar echo was simulated in the experimental work. The echo was supposed to be created by a space-born lidar (e.g. CALIOP). And white Gaussian noise was added to the echo to act as the random noise resulted from environment and the detector. The novel method, ASSM, was applied to the noisy echo to filter the noise. In the test, N was set to 3 and the Iteration time is two. The results show that, the signal could be smoothed adaptively by the ASSM, but the N and the Iteration time might be optimized when the ASSM is applied in a different lidar.

Using mixed methods research designs in health psychology: an illustrated discussion from a pragmatist perspective.

Science.gov (United States)

Bishop, Felicity L

2015-02-01

To outline some of the challenges of mixed methods research and illustrate how they can be addressed in health psychology research. This study critically reflects on the author's previously published mixed methods research and discusses the philosophical and technical challenges of mixed methods, grounding the discussion in a brief review of methodological literature. Mixed methods research is characterized as having philosophical and technical challenges; the former can be addressed by drawing on pragmatism, the latter by considering formal mixed methods research designs proposed in a number of design typologies. There are important differences among the design typologies which provide diverse examples of designs that health psychologists can adapt for their own mixed methods research. There are also similarities; in particular, many typologies explicitly orient to the technical challenges of deciding on the respective timing of qualitative and quantitative methods and the relative emphasis placed on each method. Characteristics, strengths, and limitations of different sequential and concurrent designs are identified by reviewing five mixed methods projects each conducted for a different purpose. Adapting formal mixed methods designs can help health psychologists address the technical challenges of mixed methods research and identify the approach that best fits the research questions and purpose. This does not obfuscate the need to address philosophical challenges of mixing qualitative and quantitative methods. Statement of contribution What is already known on this subject? Mixed methods research poses philosophical and technical challenges. Pragmatism in a popular approach to the philosophical challenges while diverse typologies of mixed methods designs can help address the technical challenges. Examples of mixed methods research can be hard to locate when component studies from mixed methods projects are published separately. What does this study add? Critical

Using mixed methods to develop and evaluate complex interventions in palliative care research.

Science.gov (United States)

Farquhar, Morag C; Ewing, Gail; Booth, Sara

2011-12-01

there is increasing interest in combining qualitative and quantitative research methods to provide comprehensiveness and greater knowledge yield. Mixed methods are valuable in the development and evaluation of complex interventions. They are therefore particularly valuable in palliative care research where the majority of interventions are complex, and the identification of outcomes particularly challenging. this paper aims to introduce the role of mixed methods in the development and evaluation of complex interventions in palliative care, and how they may be used in palliative care research. the paper defines mixed methods and outlines why and how mixed methods are used to develop and evaluate complex interventions, with a pragmatic focus on design and data collection issues and data analysis. Useful texts are signposted and illustrative examples provided of mixed method studies in palliative care, including a detailed worked example of the development and evaluation of a complex intervention in palliative care for breathlessness. Key challenges to conducting mixed methods in palliative care research are identified in relation to data collection, data integration in analysis, costs and dissemination and how these might be addressed. the development and evaluation of complex interventions in palliative care benefit from the application of mixed methods. Mixed methods enable better understanding of whether and how an intervention works (or does not work) and inform the design of subsequent studies. However, they can be challenging: mixed method studies in palliative care will benefit from working with agreed protocols, multidisciplinary teams and engaging staff with appropriate skill sets.

Creating and supporting a mixed methods health services research team.

Science.gov (United States)

Bowers, Barbara; Cohen, Lauren W; Elliot, Amy E; Grabowski, David C; Fishman, Nancy W; Sharkey, Siobhan S; Zimmerman, Sheryl; Horn, Susan D; Kemper, Peter

2013-12-01

To use the experience from a health services research evaluation to provide guidance in team development for mixed methods research. The Research Initiative Valuing Eldercare (THRIVE) team was organized by the Robert Wood Johnson Foundation to evaluate The Green House nursing home culture change program. This article describes the development of the research team and provides insights into how funders might engage with mixed methods research teams to maximize the value of the team. Like many mixed methods collaborations, the THRIVE team consisted of researchers from diverse disciplines, embracing diverse methodologies, and operating under a framework of nonhierarchical, shared leadership that required new collaborations, engagement, and commitment in the context of finite resources. Strategies to overcome these potential obstacles and achieve success included implementation of a Coordinating Center, dedicated time for planning and collaborating across researchers and methodologies, funded support for in-person meetings, and creative optimization of resources. Challenges are inevitably present in the formation and operation of effective mixed methods research teams. However, funders and research teams can implement strategies to promote success. © Health Research and Educational Trust.

Guidance for using mixed methods design in nursing practice research.

Science.gov (United States)

Chiang-Hanisko, Lenny; Newman, David; Dyess, Susan; Piyakong, Duangporn; Liehr, Patricia

2016-08-01

The mixed methods approach purposefully combines both quantitative and qualitative techniques, enabling a multi-faceted understanding of nursing phenomena. The purpose of this article is to introduce three mixed methods designs (parallel; sequential; conversion) and highlight interpretive processes that occur with the synthesis of qualitative and quantitative findings. Real world examples of research studies conducted by the authors will demonstrate the processes leading to the merger of data. The examples include: research questions; data collection procedures and analysis with a focus on synthesizing findings. Based on experience with mixed methods studied, the authors introduce two synthesis patterns (complementary; contrasting), considering application for practice and implications for research. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel signal compression method based on optimal ensemble empirical mode decomposition for bearing vibration signals

Science.gov (United States)