Designs of Empirical Evaluations of Nonexperimental Methods in Field Settings.

PubMed

Wong, Vivian C; Steiner, Peter M

2018-01-01

Over the last three decades, a research design has emerged to evaluate the performance of nonexperimental (NE) designs and design features in field settings. It is called the within-study comparison (WSC) approach or the design replication study. In the traditional WSC design, treatment effects from a randomized experiment are compared to those produced by an NE approach that shares the same target population. The nonexperiment may be a quasi-experimental design, such as a regression-discontinuity or an interrupted time-series design, or an observational study approach that includes matching methods, standard regression adjustments, and difference-in-differences methods. The goals of the WSC are to determine whether the nonexperiment can replicate results from a randomized experiment (which provides the causal benchmark estimate), and the contexts and conditions under which these methods work in practice. This article presents a coherent theory of the design and implementation of WSCs for evaluating NE methods. It introduces and identifies the multiple purposes of WSCs, required design components, common threats to validity, design variants, and causal estimands of interest in WSCs. It highlights two general approaches for empirical evaluations of methods in field settings, WSC designs with independent and dependent benchmark and NE arms. This article highlights advantages and disadvantages for each approach, and conditions and contexts under which each approach is optimal for addressing methodological questions.

Designing Studies That Would Address the Multilayered Nature of Health Care

PubMed Central

Pennell, Michael; Rhoda, Dale; Hade, Erinn M.; Paskett, Electra D.

2010-01-01

We review design and analytic methods available for multilevel interventions in cancer research with particular attention to study design, sample size requirements, and potential to provide statistical evidence for causal inference. The most appropriate methods will depend on the stage of development of the research and whether randomization is possible. Early on, fractional factorial designs may be used to screen intervention components, particularly when randomization of individuals is possible. Quasi-experimental designs, including time-series and multiple baseline designs, can be useful once the intervention is designed because they require few sites and can provide the preliminary evidence to plan efficacy studies. In efficacy and effectiveness studies, group-randomized trials are preferred when randomization is possible and regression discontinuity designs are preferred otherwise if assignment based on a quantitative score is possible. Quasi-experimental designs may be used, especially when combined with recent developments in analytic methods to reduce bias in effect estimates. PMID:20386057

Evaluating hospital design from an operations management perspective.

PubMed

Vos, Leti; Groothuis, Siebren; van Merode, Godefridus G

2007-12-01

This paper describes an evaluation method for the assessment of hospital building design from the viewpoint of operations management to assure that the building design supports the efficient and effective operating of care processes now and in the future. The different steps of the method are illustrated by a case study. In the case study an experimental design is applied to assess the effect of used logistical concepts, patient mix and technologies. The study shows that the evaluation method provides a valuable tool for the assessment of both functionality and the ability to meet future developments in operational control of a building design.

Topology Optimization using the Level Set and eXtended Finite Element Methods: Theory and Applications

NASA Astrophysics Data System (ADS)

Villanueva Perez, Carlos Hernan

Computational design optimization provides designers with automated techniques to develop novel and non-intuitive optimal designs. Topology optimization is a design optimization technique that allows for the evolution of a broad variety of geometries in the optimization process. Traditional density-based topology optimization methods often lack a sufficient resolution of the geometry and physical response, which prevents direct use of the optimized design in manufacturing and the accurate modeling of the physical response of boundary conditions. The goal of this thesis is to introduce a unified topology optimization framework that uses the Level Set Method (LSM) to describe the design geometry and the eXtended Finite Element Method (XFEM) to solve the governing equations and measure the performance of the design. The methodology is presented as an alternative to density-based optimization approaches, and is able to accommodate a broad range of engineering design problems. The framework presents state-of-the-art methods for immersed boundary techniques to stabilize the systems of equations and enforce the boundary conditions, and is studied with applications in 2D and 3D linear elastic structures, incompressible flow, and energy and species transport problems to test the robustness and the characteristics of the method. A comparison of the framework against density-based topology optimization approaches is studied with regards to convergence, performance, and the capability to manufacture the designs. Furthermore, the ability to control the shape of the design to operate within manufacturing constraints is developed and studied. The analysis capability of the framework is validated quantitatively through comparison against previous benchmark studies, and qualitatively through its application to topology optimization problems. The design optimization problems converge to intuitive designs and resembled well the results from previous 2D or density-based studies.

Statistical inference for the additive hazards model under outcome-dependent sampling.

PubMed

Yu, Jichang; Liu, Yanyan; Sandler, Dale P; Zhou, Haibo

2015-09-01

Cost-effective study design and proper inference procedures for data from such designs are always of particular interests to study investigators. In this article, we propose a biased sampling scheme, an outcome-dependent sampling (ODS) design for survival data with right censoring under the additive hazards model. We develop a weighted pseudo-score estimator for the regression parameters for the proposed design and derive the asymptotic properties of the proposed estimator. We also provide some suggestions for using the proposed method by evaluating the relative efficiency of the proposed method against simple random sampling design and derive the optimal allocation of the subsamples for the proposed design. Simulation studies show that the proposed ODS design is more powerful than other existing designs and the proposed estimator is more efficient than other estimators. We apply our method to analyze a cancer study conducted at NIEHS, the Cancer Incidence and Mortality of Uranium Miners Study, to study the risk of radon exposure to cancer.

Statistical inference for the additive hazards model under outcome-dependent sampling

PubMed Central

Yu, Jichang; Liu, Yanyan; Sandler, Dale P.; Zhou, Haibo

2015-01-01

Cost-effective study design and proper inference procedures for data from such designs are always of particular interests to study investigators. In this article, we propose a biased sampling scheme, an outcome-dependent sampling (ODS) design for survival data with right censoring under the additive hazards model. We develop a weighted pseudo-score estimator for the regression parameters for the proposed design and derive the asymptotic properties of the proposed estimator. We also provide some suggestions for using the proposed method by evaluating the relative efficiency of the proposed method against simple random sampling design and derive the optimal allocation of the subsamples for the proposed design. Simulation studies show that the proposed ODS design is more powerful than other existing designs and the proposed estimator is more efficient than other estimators. We apply our method to analyze a cancer study conducted at NIEHS, the Cancer Incidence and Mortality of Uranium Miners Study, to study the risk of radon exposure to cancer. PMID:26379363

Bias correction of risk estimates in vaccine safety studies with rare adverse events using a self-controlled case series design.

PubMed

Zeng, Chan; Newcomer, Sophia R; Glanz, Jason M; Shoup, Jo Ann; Daley, Matthew F; Hambidge, Simon J; Xu, Stanley

2013-12-15

The self-controlled case series (SCCS) method is often used to examine the temporal association between vaccination and adverse events using only data from patients who experienced such events. Conditional Poisson regression models are used to estimate incidence rate ratios, and these models perform well with large or medium-sized case samples. However, in some vaccine safety studies, the adverse events studied are rare and the maximum likelihood estimates may be biased. Several bias correction methods have been examined in case-control studies using conditional logistic regression, but none of these methods have been evaluated in studies using the SCCS design. In this study, we used simulations to evaluate 2 bias correction approaches-the Firth penalized maximum likelihood method and Cordeiro and McCullagh's bias reduction after maximum likelihood estimation-with small sample sizes in studies using the SCCS design. The simulations showed that the bias under the SCCS design with a small number of cases can be large and is also sensitive to a short risk period. The Firth correction method provides finite and less biased estimates than the maximum likelihood method and Cordeiro and McCullagh's method. However, limitations still exist when the risk period in the SCCS design is short relative to the entire observation period.

Synthesis of calculational methods for design and analysis of radiation shields for nuclear rocket systems

NASA Technical Reports Server (NTRS)

Capo, M. A.; Disney, R. K.; Jordan, T. A.; Soltesz, R. G.; Woodsum, H. C.

1969-01-01

Eight computer programs make up a nine volume synthesis containing two design methods for nuclear rocket radiation shields. The first design method is appropriate for parametric and preliminary studies, while the second accomplishes the verification of a final nuclear rocket reactor design.

Applying Case-Based Method in Designing Self-Directed Online Instruction: A Formative Research Study

ERIC Educational Resources Information Center

Luo, Heng; Koszalka, Tiffany A.; Arnone, Marilyn P.; Choi, Ikseon

2018-01-01

This study investigated the case-based method (CBM) instructional-design theory and its application in designing self-directed online instruction. The purpose of this study was to validate and refine the theory for a self-directed online instruction context. Guided by formative research methodology, this study first developed an online tutorial…

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

PubMed

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 reflections on the author's previously published mixed methods research illustrate how a range of different mixed methods designs can be adapted and applied to address health psychology research questions. The philosophical and technical challenges of mixed methods research should be considered together and in relation to the broader purpose of the research. © 2014 The British Psychological Society.

Using Finite Element and Eigenmode Expansion Methods to Investigate the Periodic and Spectral Characteristic of Superstructure Fiber Bragg Gratings

PubMed Central

He, Yue-Jing; Hung, Wei-Chih; Lai, Zhe-Ping

2016-01-01

In this study, a numerical simulation method was employed to investigate and analyze superstructure fiber Bragg gratings (SFBGs) with five duty cycles (50%, 33.33%, 14.28%, 12.5%, and 10%). This study focuses on demonstrating the relevance between design period and spectral characteristics of SFBGs (in the form of graphics) for SFBGs of all duty cycles. Compared with complicated and hard-to-learn conventional coupled-mode theory, the result of the present study may assist beginner and expert designers in understanding the basic application aspects, optical characteristics, and design techniques of SFBGs, thereby indirectly lowering the physical concepts and mathematical skills required for entering the design field. To effectively improve the accuracy of overall computational performance and numerical calculations and to shorten the gap between simulation results and actual production, this study integrated a perfectly matched layer (PML), perfectly reflecting boundary (PRB), object meshing method (OMM), and boundary meshing method (BMM) into the finite element method (FEM) and eigenmode expansion method (EEM). The integrated method enables designers to easily and flexibly design optical fiber communication systems that conform to the specific spectral characteristic by using the simulation data in this paper, which includes bandwidth, number of channels, and band gap size. PMID:26861322

Limitations of the method of characteristics when applied to axisymmetric hypersonic nozzle design

NASA Technical Reports Server (NTRS)

Edwards, Anne C.; Perkins, John N.; Benton, James R.

1990-01-01

A design study of axisymmetric hypersonic wind tunnel nozzles was initiated by NASA Langley Research Center with the objective of improving the flow quality of their ground test facilities. Nozzles for Mach 6 air, Mach 13.5 nitrogen, and Mach 17 nitrogen were designed using the Method of Characteristics/Boundary Layer (MOC/BL) approach and were analyzed with a Navier-Stokes solver. Results of the analysis agreed well with design for the Mach 6 case, but revealed oblique shock waves of increasing strength originating from near the inflection point of the Mach 13.5 and Mach 17 nozzles. The findings indicate that the MOC/BL design method has a fundamental limitation that occurs at some Mach number between 6 an 13.5. In order to define the limitation more exactly and attempt to discover the cause, a parametric study of hypersonic ideal air nozzles designed with the current MOC/BL method was done. Results of this study indicate that, while stagnations conditions have a moderate affect on the upper limit of the method, the method fails at Mach numbers above 8.0.

Investigating the Use of Design Methods by Capstone Design Students at Clemson University

ERIC Educational Resources Information Center

Miller, W. Stuart; Summers, Joshua D.

2013-01-01

The authors describe a preliminary study to understand the attitude of engineering students regarding the use of design methods in projects to identify the factors either affecting or influencing the use of these methods by novice engineers. A senior undergraduate capstone design course at Clemson University, consisting of approximately fifty…

Development of Design Guidelines for Tools to Promote Differentiated Instruction in Classroom Teaching

ERIC Educational Resources Information Center

Cha, H. J.; Ahn, M. L.

2014-01-01

The purpose of this study was to elicit design guidelines for a teacher tool to support students' diverse needs by facilitating differentiated instructions (DIs). The study used a framework based on activity theory and principles from universal design for learning. As for the research methods, design-based research methods were adopted, and as the…

Quantitative methods used in Australian health promotion research: a review of publications from 1992-2002.

PubMed

Smith, Ben J; Zehle, Katharina; Bauman, Adrian E; Chau, Josephine; Hawkshaw, Barbara; Frost, Steven; Thomas, Margaret

2006-04-01

This study examined the use of quantitative methods in Australian health promotion research in order to identify methodological trends and priorities for strengthening the evidence base for health promotion. Australian health promotion articles were identified by hand searching publications from 1992-2002 in six journals: Health Promotion Journal of Australia, Australian and New Zealand journal of Public Health, Health Promotion International, Health Education Research, Health Education and Behavior and the American Journal of Health Promotion. The study designs and statistical methods used in articles presenting quantitative research were recorded. 591 (57.7%) of the 1,025 articles used quantitative methods. Cross-sectional designs were used in the majority (54.3%) of studies with pre- and post-test (14.6%) and post-test only (9.5%) the next most common designs. Bivariate statistical methods were used in 45.9% of papers, multivariate methods in 27.1% and simple numbers and proportions in 25.4%. Few studies used higher-level statistical techniques. While most studies used quantitative methods, the majority were descriptive in nature. The study designs and statistical methods used provided limited scope for demonstrating intervention effects or understanding the determinants of change.

TLNS3D/CDISC Multipoint Design of the TCA Concept

NASA Technical Reports Server (NTRS)

Campbell, Richard L.; Mann, Michael J.

1999-01-01

This paper presents the work done to date by the authors on developing an efficient approach to multipoint design and applying it to the design of the HSR TCA (High Speed Research Technology Concept Aircraft) configuration. While the title indicates that this exploratory study has been performed using the TLNS3DMB flow solver and the CDISC (Constrained Direct Iterative Surface Curvature) design method, the CDISC method could have been used with any flow solver, and the multipoint design approach does not require the use of CDISC. The goal of the study was to develop a multipoint design method that could achieve a design in about the same time as 10 analysis runs.

Novel ergonomic postural assessment method (NERPA) using product-process computer aided engineering for ergonomic workplace design.

PubMed

Sanchez-Lite, Alberto; Garcia, Manuel; Domingo, Rosario; Angel Sebastian, Miguel

2013-01-01

Musculoskeletal disorders (MSDs) that result from poor ergonomic design are one of the occupational disorders of greatest concern in the industrial sector. A key advantage in the primary design phase is to focus on a method of assessment that detects and evaluates the potential risks experienced by the operative when faced with these types of physical injuries. The method of assessment will improve the process design identifying potential ergonomic improvements from various design alternatives or activities undertaken as part of the cycle of continuous improvement throughout the differing phases of the product life cycle. This paper presents a novel postural assessment method (NERPA) fit for product-process design, which was developed with the help of a digital human model together with a 3D CAD tool, which is widely used in the aeronautic and automotive industries. The power of 3D visualization and the possibility of studying the actual assembly sequence in a virtual environment can allow the functional performance of the parts to be addressed. Such tools can also provide us with an ergonomic workstation design, together with a competitive advantage in the assembly process. The method developed was used in the design of six production lines, studying 240 manual assembly operations and improving 21 of them. This study demonstrated the proposed method's usefulness and found statistically significant differences in the evaluations of the proposed method and the widely used Rapid Upper Limb Assessment (RULA) method.

Design methodology for micro-discrete planar optics with minimum illumination loss for an extended source.

PubMed

Shim, Jongmyeong; Park, Changsu; Lee, Jinhyung; Kang, Shinill

2016-08-08

Recently, studies have examined techniques for modeling the light distribution of light-emitting diodes (LEDs) for various applications owing to their low power consumption, longevity, and light weight. The energy mapping technique, a design method that matches the energy distributions of an LED light source and target area, has been the focus of active research because of its design efficiency and accuracy. However, these studies have not considered the effects of the emitting area of the LED source. Therefore, there are limitations to the design accuracy for small, high-power applications with a short distance between the light source and optical system. A design method for compensating for the light distribution of an extended source after the initial optics design based on a point source was proposed to overcome such limits, but its time-consuming process and limited design accuracy with multiple iterations raised the need for a new design method that considers an extended source in the initial design stage. This study proposed a method for designing discrete planar optics that controls the light distribution and minimizes the optical loss with an extended source and verified the proposed method experimentally. First, the extended source was modeled theoretically, and a design method for discrete planar optics with the optimum groove angle through energy mapping was proposed. To verify the design method, design for the discrete planar optics was achieved for applications in illumination for LED flash. In addition, discrete planar optics for LED illuminance were designed and fabricated to create a uniform illuminance distribution. Optical characterization of these structures showed that the design was optimal; i.e., we plotted the optical losses as a function of the groove angle, and found a clear minimum. Simulations and measurements showed that an efficient optical design was achieved for an extended source.

Contextualizing and assessing the social capital of seniors in congregate housing residences: study design and methods

PubMed Central

Moore, Spencer; Shiell, Alan; Haines, Valerie; Riley, Therese; Collier, Carrie

2005-01-01

Background This article discusses the study design and methods used to contextualize and assess the social capital of seniors living in congregate housing residences in Calgary, Alberta. The project is being funded as a pilot project under the Institute of Aging, Canadian Institutes for Health Research. Design/Methods Working with seniors living in 5 congregate housing residencies in Calgary, the project uses a mixed method approach to develop grounded measures of the social capital of seniors. The project integrates both qualitative and quantitative methods in a 3-phase research design: 1) qualitative, 2) quantitative, and 3) qualitative. Phase 1 uses gender-specific focus groups; phase 2 involves the administration of individual surveys that include a social network module; and phase 3 uses anamolous-case interviews. Not only does the study design allow us to develop grounded measures of social capital but it also permits us to test how well the three methods work separately, and how well they fit together to achieve project goals. This article describes the selection of the study population, the multiple methods used in the research and a brief discussion of our conceptualization and measurement of social capital. PMID:15836784

A Study of Trial and Error Learning in Technology, Engineering, and Design Education

ERIC Educational Resources Information Center

Franzen, Marissa Marie Sloan

2016-01-01

The purpose of this research study was to determine if trial and error learning was an effective, practical, and efficient learning method for Technology, Engineering, and Design Education students at the post-secondary level. A mixed methods explanatory research design was used to measure the viability of the learning source. The study sample was…

What Informs Practice and What Is Valued in Corporate Instructional Design? A Mixed Methods Study

ERIC Educational Resources Information Center

Thompson-Sellers, Ingrid N.

2012-01-01

This study used a two-phased explanatory mixed-methods design to explore in-depth what factors are perceived by Instructional Design and Technology (IDT) professionals as impacting instructional design practice, how these factors are valued in the field, and what differences in perspectives exist between IDT managers and non-managers. For phase 1…

The Influence of Elective Surgery on Functional Health in Veterans with PTSD

DTIC Science & Technology

2012-12-21

elective surgery in veterans with PTSD. Design : A longitudinal, mixed method, quasi-experimental, nonequivalent control group study was conducted...longitudinal, mixed method, quasi-experimental, nonequivalent control group study was conducted. Methods and Sample: Physical and mental health...Methods Procedures." In Research design : qualitative, quantitative , and mixed methods approaches, 203-226. Thousand Oaks, Calif.: Sage Publications

Shape design of an optimal comfortable pillow based on the analytic hierarchy process method

PubMed Central

Liu, Shuo-Fang; Lee, Yann-Long; Liang, Jung-Chin

2011-01-01

Objective Few studies have analyzed the shapes of pillows. The purpose of this study was to investigate the relationship between the pillow shape design and subjective comfort level for asymptomatic subjects. Methods Four basic pillow designs factors were selected on the basis of literature review and recombined into 8 configurations for testing the rank of degrees of comfort. The data were analyzed by the analytic hierarchy process method to determine the most comfortable pillow. Results Pillow number 4 was the most comfortable pillow in terms of head, neck, shoulder, height, and overall comfort. The design factors of pillow number 4 were using a combination of standard, cervical, and shoulder pillows. A prototype of this pillow was developed on the basis of the study results for designing future pillow shapes. Conclusions This study investigated the comfort level of particular users and redesign features of a pillow. A deconstruction analysis would simplify the process of determining the most comfortable pillow design and aid designers in designing pillows for groups. PMID:22654680

Examining Development of Curriculum Knowledge of Prospective Mathematics Teachers

ERIC Educational Resources Information Center

Sahin, Ömer; Soylu, Yasin

2017-01-01

Explanatory-confirmatory research design, one of the mixed methods research designs, was used in this study to investigate Curriculum Knowledge developments of prospective teachers regarding algebra. Cross-sectional study method, as a type of descriptive research and one of the non-experimental research designs, was used to collect quantitative…

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

PubMed

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.

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Quasi-Experimental Designs.

PubMed

Schweizer, Marin L; Braun, Barbara I; Milstone, Aaron M

2016-10-01

Quasi-experimental studies evaluate the association between an intervention and an outcome using experiments in which the intervention is not randomly assigned. Quasi-experimental studies are often used to evaluate rapid responses to outbreaks or other patient safety problems requiring prompt, nonrandomized interventions. Quasi-experimental studies can be categorized into 3 major types: interrupted time-series designs, designs with control groups, and designs without control groups. This methods paper highlights key considerations for quasi-experimental studies in healthcare epidemiology and antimicrobial stewardship, including study design and analytic approaches to avoid selection bias and other common pitfalls of quasi-experimental studies. Infect Control Hosp Epidemiol 2016;1-6.

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship – Quasi-Experimental Designs

PubMed Central

Schweizer, Marin L.; Braun, Barbara I.; Milstone, Aaron M.

2016-01-01

Quasi-experimental studies evaluate the association between an intervention and an outcome using experiments in which the intervention is not randomly assigned. Quasi-experimental studies are often used to evaluate rapid responses to outbreaks or other patient safety problems requiring prompt non-randomized interventions. Quasi-experimental studies can be categorized into three major types: interrupted time series designs, designs with control groups, and designs without control groups. This methods paper highlights key considerations for quasi-experimental studies in healthcare epidemiology and antimicrobial stewardship including study design and analytic approaches to avoid selection bias and other common pitfalls of quasi-experimental studies. PMID:27267457

[Discussion on development of four diagnostic information scale for clinical re-evaluation of postmarketing herbs].

PubMed

He, Wei; Xie, Yanming; Wang, Yongyan

2011-12-01

Post-marketing re-evaluation of Chinese herbs can well reflect Chinese medicine characteristics, which is the most easily overlooked the clinical re-evaluation content. Since little attention has been paid to this, study on the clinical trial design method was lost. It is difficult to improving the effectiveness and safety of traditional Chinese medicine. Therefore, more attention should be paid on re-evaluation of the clinical trial design method point about tcm syndrome such as the type of research program design, the study of Chinese medical information collection scale and statistical analysis methods, so as to improve the clinical trial design method study about tcm syndrome of Chinese herbs postmarketing re-evalutation status.

A Rapid Aerodynamic Design Procedure Based on Artificial Neural Networks

NASA Technical Reports Server (NTRS)

Rai, Man Mohan

2001-01-01

An aerodynamic design procedure that uses neural networks to model the functional behavior of the objective function in design space has been developed. This method incorporates several improvements to an earlier method that employed a strategy called parameter-based partitioning of the design space in order to reduce the computational costs associated with design optimization. As with the earlier method, the current method uses a sequence of response surfaces to traverse the design space in search of the optimal solution. The new method yields significant reductions in computational costs by using composite response surfaces with better generalization capabilities and by exploiting synergies between the optimization method and the simulation codes used to generate the training data. These reductions in design optimization costs are demonstrated for a turbine airfoil design study where a generic shape is evolved into an optimal airfoil.

METHODS ADVANCEMENT FOR MILK ANALYSIS: THE MAMA STUDY

EPA Science Inventory

The Methods Advancement for Milk Analysis (MAMA) study was designed by US EPA and CDC investigators to provide data to support the technological and study design needs of the proposed National Children=s Study (NCS). The NCS is a multi-Agency-sponsored study, authorized under the...

The Effectiveness of Teaching Methods Used in Graphic Design Pedagogy in Both Analogue and Digital Education Systems

ERIC Educational Resources Information Center

Alhajri, Salman

2016-01-01

Purpose: this paper investigates the effectiveness of teaching methods used in graphic design pedagogy in both analogue and digital education systems. Methodology and approach: the paper is based on theoretical study using a qualitative, case study approach. Comparison between the digital teaching methods and traditional teaching methods was…

LQAS: User Beware.

PubMed

Rhoda, Dale A; Fernandez, Soledad A; Fitch, David J; Lemeshow, Stanley

2010-02-01

Researchers around the world are using Lot Quality Assurance Sampling (LQAS) techniques to assess public health parameters and evaluate program outcomes. In this paper, we report that there are actually two methods being called LQAS in the world today, and that one of them is badly flawed. This paper reviews fundamental LQAS design principles, and compares and contrasts the two LQAS methods. We raise four concerns with the simply-written, freely-downloadable training materials associated with the second method. The first method is founded on sound statistical principles and is carefully designed to protect the vulnerable populations that it studies. The language used in the training materials for the second method is simple, but not at all clear, so the second method sounds very much like the first. On close inspection, however, the second method is found to promote study designs that are biased in favor of finding programmatic or intervention success, and therefore biased against the interests of the population being studied. We outline several recommendations, and issue a call for a new high standard of clarity and face validity for those who design, conduct, and report LQAS studies.

A Qualitative Study about Performance Based Assesment Methods Used in Information Technologies Lesson

ERIC Educational Resources Information Center

Daghan, Gökhan; Akkoyunlu, Buket

2014-01-01

In this study, Information Technologies teachers' views and usage cases on performance based assesment methods (PBAMs) are examined. It is aimed to find out which of the PBAMs are used frequently or not used, preference reasons of these methods and opinions about the applicability of them. Study is designed with the phenomenological design which…

[The mixed design in nursing sciences or when a question of research calls for qualitative and quantitative strategies].

PubMed

Bourgault, Patricia; Gallagher, Frances; Michaud, Cécile; Saint-Cyr-Tribble, Denise

2010-12-01

The use of a mixed method research design raises many questions, especially regarding the paradigmatic position. With this paradigm, we may consider the mixed method design as the best way of answering a research question and the latter orients to one of the different subtypes of mixed method design. To illustrate the use of this kind of design, we propose a study such as conducted in nursing sciences. In this article, the challenges raised by the mixed method design, and the place of this type of research in nursing sciences is discussed.

Design of spoke type motor and magnetizer for improving efficiency based rare-earth-free permanent-magnet motor

NASA Astrophysics Data System (ADS)

Kim, Young Hyun; Cheon, Byung Chul; Lee, Jung Ho

2018-05-01

This study proposes criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration. The optimal design of the stator and rotor can be enhanced using both a response surface method and finite element method. In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor. Finally, this study verifies that the proposed motor can efficiently replace interior permanent magnet synchronous motor in many industries.

Numerical studies of the thermal design sensitivity calculation for a reaction-diffusion system with discontinuous derivatives

NASA Technical Reports Server (NTRS)

Hou, Jean W.; Sheen, Jeen S.

1987-01-01

The aim of this study is to find a reliable numerical algorithm to calculate thermal design sensitivities of a transient problem with discontinuous derivatives. The thermal system of interest is a transient heat conduction problem related to the curing process of a composite laminate. A logical function which can smoothly approximate the discontinuity is introduced to modify the system equation. Two commonly used methods, the adjoint variable method and the direct differentiation method, are then applied to find the design derivatives of the modified system. The comparisons of numerical results obtained by these two methods demonstrate that the direct differentiation method is a better choice to be used in calculating thermal design sensitivity.

[The methods within the evaluation of disease management programmes in control-group designs using the example of diabetes mellitus - a systematic literature review].

PubMed

Drabik, A; Sawicki, P T; Müller, D; Passon, A; Stock, S

2012-08-01

Disease management programmes (DMPs) were implemented in Germany in 2002. Their evaluation is required by law. Beyond the mandatory evaluation, a growing number of published studies evaluate the DMP for diabetes mellitus type 2 in a control-group design. As patients opt into the programme on a voluntary basis it is necessary to adjust the inherent selection bias between groups. The aim of this study is to review published studies which evaluate the diabetes DMP using a control-group design with respect to the methods used. A systematic literature review of electronic databases (PUBMED, Cochrane Library, EMBASE, MEDPILOT) and a hand search of reference lists of the relevant publications was conducted to identify studies evaluating the DMP diabetes mellitus in a control-group design. 8 studies were included in the systematic literature review. 4 studies gathered retrospective claims data from sickness funds, one from physician's records, one study used prospective data from ambulatory care, and 2 studies were based on one patient survey. Methods used for adjustment of selection bias included exact matching, matching using propensity score methods, age-adjusted and sex-separated analysis, and adjustment in a regression model/analysis of covariance. One study did not apply adjustment methods. The intervention period ranged from 1 day to 4 years. Considered outcomes of studies (surrogate parameter, diabetes complications, mortality, quality of life, and claim data) depended on the database. In the evaluation of the DMP diabetes mellitus based on a control-group design neither the database nor the methods used for selection bias adjustment were consistent in the available studies. Effectiveness of DMPs cannot be judged based on this review due to heterogeneity of study designs. To allow for a comprehensive programme evaluation standardised minimum requirements for the evaluation of DMPs in the control group design are required. © Georg Thieme Verlag KG Stuttgart · New York.

Knowledge of Metabolic Syndrome in Chinese Adults: Implications for Health Education

ERIC Educational Resources Information Center

Lo, Sally Wai Sze; Chair, Sek Ying; Lee, Iris Fung Kam

2016-01-01

Objective: The objective of this study was to assess knowledge of metabolic syndrome (MS) among Chinese adults and provide directions for designing healthcare promotion schemes for improving MS awareness in the community. Design: The study adopted a cross-sectional design and a convenience sampling method. Method: Chinese adults aged 18-65 years…

Curiosity and Pedagogy: A Mixed-Methods Study of Student Experiences in the Design Studio

ERIC Educational Resources Information Center

Smith, Korydon H.

2010-01-01

Curiosity is often considered the foundation of learning. There is, however, little understanding of how (or if) pedagogy in higher education affects student curiosity, especially in the studio setting of architecture, interior design, and landscape architecture. This study used mixed-methods to investigate curiosity among design students in the…

Rationale, Design, and Methods of the Preschool ADHD Treatment Study (PATS)

ERIC Educational Resources Information Center

Kollins, Scott; Greenhill, Laurence; Swanson, James; Wigal, Sharon; Abikoff, Howard; McCracken, James; Riddle, Mark; McGough, James; Vitiello, Benedetto; Wigal, Tim; Skrobala, Anne; Posner, Kelly; Ghuman, Jaswinder; Davies, Mark; Cunningham, Charles; Bauzo, Audrey

2006-01-01

Objective: To describe the rationale and design of the Preschool ADHD Treatment Study (PATS). Method: PATS was a National Institutes of Mental Health-funded, multicenter, randomized, efficacy trial designed to evaluate the short-term (5 weeks) efficacy and long-term (40 weeks) safety of methylphenidate (MPH) in preschoolers with…

City Governments and Aging in Place: Community Design, Transportation and Housing Innovation Adoption

ERIC Educational Resources Information Center

Lehning, Amanda J.

2012-01-01

Purpose of the study: To examine the characteristics associated with city government adoption of community design, housing, and transportation innovations that could benefit older adults. Design and methods: A mixed-methods study with quantitative data collected via online surveys from 62 city planners combined with qualitative data collected via…

Tradeoff studies in multiobjective insensitive design of airplane control systems

NASA Technical Reports Server (NTRS)

Schy, A. A.; Giesy, D. P.

1983-01-01

A computer aided design method for multiobjective parameter-insensitive design of airplane control systems is described. Methods are presented for trading off nominal values of design objectives against sensitivities of the design objectives to parameter uncertainties, together with guidelines for designer utilization of the methods. The methods are illustrated by application to the design of a lateral stability augmentation system for two supersonic flight conditions of the Shuttle Orbiter. Objective functions are conventional handling quality measures and peak magnitudes of control deflections and rates. The uncertain parameters are assumed Gaussian, and numerical approximations of the stochastic behavior of the objectives are described. Results of applying the tradeoff methods to this example show that stochastic-insensitive designs are distinctly different from deterministic multiobjective designs. The main penalty for achieving significant decrease in sensitivity is decreased speed of response for the nominal system.

Quasi-experimental Studies in the Fields of Infection Control and Antibiotic Resistance, Ten Years Later: A Systematic Review.

PubMed

Alsaggaf, Rotana; O'Hara, Lyndsay M; Stafford, Kristen A; Leekha, Surbhi; Harris, Anthony D

2018-02-01

OBJECTIVE A systematic review of quasi-experimental studies in the field of infectious diseases was published in 2005. The aim of this study was to assess improvements in the design and reporting of quasi-experiments 10 years after the initial review. We also aimed to report the statistical methods used to analyze quasi-experimental data. DESIGN Systematic review of articles published from January 1, 2013, to December 31, 2014, in 4 major infectious disease journals. METHODS Quasi-experimental studies focused on infection control and antibiotic resistance were identified and classified based on 4 criteria: (1) type of quasi-experimental design used, (2) justification of the use of the design, (3) use of correct nomenclature to describe the design, and (4) statistical methods used. RESULTS Of 2,600 articles, 173 (7%) featured a quasi-experimental design, compared to 73 of 2,320 articles (3%) in the previous review (P<.01). Moreover, 21 articles (12%) utilized a study design with a control group; 6 (3.5%) justified the use of a quasi-experimental design; and 68 (39%) identified their design using the correct nomenclature. In addition, 2-group statistical tests were used in 75 studies (43%); 58 studies (34%) used standard regression analysis; 18 (10%) used segmented regression analysis; 7 (4%) used standard time-series analysis; 5 (3%) used segmented time-series analysis; and 10 (6%) did not utilize statistical methods for comparisons. CONCLUSIONS While some progress occurred over the decade, it is crucial to continue improving the design and reporting of quasi-experimental studies in the fields of infection control and antibiotic resistance to better evaluate the effectiveness of important interventions. Infect Control Hosp Epidemiol 2018;39:170-176.

efficient association study design via power-optimized tag SNP selection

PubMed Central

HAN, BUHM; KANG, HYUN MIN; SEO, MYEONG SEONG; ZAITLEN, NOAH; ESKIN, ELEAZAR

2008-01-01

Discovering statistical correlation between causal genetic variation and clinical traits through association studies is an important method for identifying the genetic basis of human diseases. Since fully resequencing a cohort is prohibitively costly, genetic association studies take advantage of local correlation structure (or linkage disequilibrium) between single nucleotide polymorphisms (SNPs) by selecting a subset of SNPs to be genotyped (tag SNPs). While many current association studies are performed using commercially available high-throughput genotyping products that define a set of tag SNPs, choosing tag SNPs remains an important problem for both custom follow-up studies as well as designing the high-throughput genotyping products themselves. The most widely used tag SNP selection method optimizes over the correlation between SNPs (r2). However, tag SNPs chosen based on an r2 criterion do not necessarily maximize the statistical power of an association study. We propose a study design framework that chooses SNPs to maximize power and efficiently measures the power through empirical simulation. Empirical results based on the HapMap data show that our method gains considerable power over a widely used r2-based method, or equivalently reduces the number of tag SNPs required to attain the desired power of a study. Our power-optimized 100k whole genome tag set provides equivalent power to the Affymetrix 500k chip for the CEU population. For the design of custom follow-up studies, our method provides up to twice the power increase using the same number of tag SNPs as r2-based methods. Our method is publicly available via web server at http://design.cs.ucla.edu. PMID:18702637

Visual Design Principles: An Empirical Study of Design Lore

ERIC Educational Resources Information Center

Kimball, Miles A.

2013-01-01

Many books, designers, and design educators talk about visual design principles such as balance, contrast, and alignment, but with little consistency. This study uses empirical methods to explore the lore surrounding design principles. The study took the form of two stages: a quantitative literature review to determine what design principles are…

Permanent Ground Anchors : Nicholson Design Criteria

DOT National Transportation Integrated Search

1982-09-01

This study discusses the methods used by Nicholson Construction Company in the design of permanent ground anchors specifically as related to retaining walls. Basic soil parameters, design concepts, drilling and grouting methods for ground anchors are...

A Study on the Spatial Abilities of Prospective Social Studies Teachers: A Mixed Method Research

ERIC Educational Resources Information Center

Yurt, Eyüp; Tünkler, Vural

2016-01-01

This study investigated prospective social studies teachers' spatial abilities. It was conducted with 234 prospective teachers attending Social Studies Teaching departments at Education Faculties of two universities in Central and Southern Anatolia. This study, designed according to the explanatory-sequential design, is a mixed research method,…

Usage of the back-propagation method for alphabet recognition

NASA Astrophysics Data System (ADS)

Shaila Sree, R. N.; Eswaran, Kumar; Sundararajan, N.

1999-03-01

Artificial Neural Networks play a pivotal role in the branch of Artificial Intelligence. They can be trained efficiently for a variety of tasks using different methods, of which the Back Propagation method is one among them. The paper studies the choosing of various design parameters of a neural network for the Back Propagation method. The study shows that when these parameters are properly assigned, the training task of the net is greatly simplified. The character recognition problem has been chosen as a test case for this study. A sample space of different handwritten characters of the English alphabet was gathered. A Neural net is finally designed taking many the design aspects into consideration and trained for different styles of writing. Experimental results are reported and discussed. It has been found that an appropriate choice of the design parameters of the neural net for the Back Propagation method reduces the training time and improves the performance of the net.

Development of a turbomachinery design optimization procedure using a multiple-parameter nonlinear perturbation method

NASA Technical Reports Server (NTRS)

Stahara, S. S.

1984-01-01

An investigation was carried out to complete the preliminary development of a combined perturbation/optimization procedure and associated computational code for designing optimized blade-to-blade profiles of turbomachinery blades. The overall purpose of the procedures developed is to provide demonstration of a rapid nonlinear perturbation method for minimizing the computational requirements associated with parametric design studies of turbomachinery flows. The method combines the multiple parameter nonlinear perturbation method, successfully developed in previous phases of this study, with the NASA TSONIC blade-to-blade turbomachinery flow solver, and the COPES-CONMIN optimization procedure into a user's code for designing optimized blade-to-blade surface profiles of turbomachinery blades. Results of several design applications and a documented version of the code together with a user's manual are provided.

An analytical study for the design of advanced rotor airfoils

NASA Technical Reports Server (NTRS)

Kemp, L. D.

1973-01-01

A theoretical study has been conducted to design and evaluate two airfoils for helicopter rotors. The best basic shape, designed with a transonic hodograph design method, was modified to meet subsonic criteria. One airfoil had an additional constraint for low pitching-moment at the transonic design point. Airfoil characteristics were predicted. Results of a comparative analysis of helicopter performance indicate that the new airfoils will produce reduced rotor power requirements compared to the NACA 0012. The hodograph design method, written in CDC Algol, is listed and described.

Using a mixed-methods design to examine nurse practitioner integration in British Columbia.

PubMed

Sangster-Gormley, Esther; Griffith, Janessa; Schreiber, Rita; Borycki, Elizabeth

2015-07-01

To discuss and provide examples of how mixed-methods research was used to evaluate the integration of nurse practitioners (NPs) into a Canadian province. Legislation enabling NPs to practise in British Columbia (BC) was enacted in 2005. This research evaluated the integration of NPs and their effect on the BC healthcare system. Data were collected using surveys, focus groups, participant interviews and case studies over three years. Data sources and methods were triangulated to determine how the findings addressed the research questions. The challenges and benefits of using the multiphase design are highlighted in the paper. The multiphase mixed-methods research design was selected because of its applicability to evaluation research. The design proved to be robust and flexible in answering research questions. As sub-studies within the multiphase design are often published separately, it can be difficult for researchers to find examples. This paper highlights ways that a multiphase mixed-methods design can be conducted for researchers unfamiliar with the process.

A systematic composite service design modeling method using graph-based theory.

PubMed

Elhag, Arafat Abdulgader Mohammed; Mohamad, Radziah; Aziz, Muhammad Waqar; Zeshan, Furkh

2015-01-01

The composite service design modeling is an essential process of the service-oriented software development life cycle, where the candidate services, composite services, operations and their dependencies are required to be identified and specified before their design. However, a systematic service-oriented design modeling method for composite services is still in its infancy as most of the existing approaches provide the modeling of atomic services only. For these reasons, a new method (ComSDM) is proposed in this work for modeling the concept of service-oriented design to increase the reusability and decrease the complexity of system while keeping the service composition considerations in mind. Furthermore, the ComSDM method provides the mathematical representation of the components of service-oriented design using the graph-based theoryto facilitate the design quality measurement. To demonstrate that the ComSDM method is also suitable for composite service design modeling of distributed embedded real-time systems along with enterprise software development, it is implemented in the case study of a smart home. The results of the case study not only check the applicability of ComSDM, but can also be used to validate the complexity and reusability of ComSDM. This also guides the future research towards the design quality measurement such as using the ComSDM method to measure the quality of composite service design in service-oriented software system.

A Systematic Composite Service Design Modeling Method Using Graph-Based Theory

PubMed Central

Elhag, Arafat Abdulgader Mohammed; Mohamad, Radziah; Aziz, Muhammad Waqar; Zeshan, Furkh

2015-01-01

The composite service design modeling is an essential process of the service-oriented software development life cycle, where the candidate services, composite services, operations and their dependencies are required to be identified and specified before their design. However, a systematic service-oriented design modeling method for composite services is still in its infancy as most of the existing approaches provide the modeling of atomic services only. For these reasons, a new method (ComSDM) is proposed in this work for modeling the concept of service-oriented design to increase the reusability and decrease the complexity of system while keeping the service composition considerations in mind. Furthermore, the ComSDM method provides the mathematical representation of the components of service-oriented design using the graph-based theoryto facilitate the design quality measurement. To demonstrate that the ComSDM method is also suitable for composite service design modeling of distributed embedded real-time systems along with enterprise software development, it is implemented in the case study of a smart home. The results of the case study not only check the applicability of ComSDM, but can also be used to validate the complexity and reusability of ComSDM. This also guides the future research towards the design quality measurement such as using the ComSDM method to measure the quality of composite service design in service-oriented software system. PMID:25928358

How Learning Designs, Teaching Methods and Activities Differ by Discipline in Australian Universities

ERIC Educational Resources Information Center

Cameron, Leanne

2017-01-01

This paper reports on the learning designs, teaching methods and activities most commonly employed within the disciplines in six universities in Australia. The study sought to establish if there were significant differences between the disciplines in learning designs, teaching methods and teaching activities in the current Australian context, as…

7 CFR 4280.103 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... established design, and installation procedures and practices. Professional service providers, trades, large... term without grant assistance. Design/build method. A method of project development whereby all design..., or encumbrances. Feasibility study. An analysis of the economic, market, technical, financial, and...

7 CFR 4280.103 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... established design, and installation procedures and practices. Professional service providers, trades, large... term without grant assistance. Design/build method. A method of project development whereby all design..., or encumbrances. Feasibility study. An analysis of the economic, market, technical, financial, and...

Novel Ergonomic Postural Assessment Method (NERPA) Using Product-Process Computer Aided Engineering for Ergonomic Workplace Design

PubMed Central

Sanchez-Lite, Alberto; Garcia, Manuel; Domingo, Rosario; Angel Sebastian, Miguel

2013-01-01

Background Musculoskeletal disorders (MSDs) that result from poor ergonomic design are one of the occupational disorders of greatest concern in the industrial sector. A key advantage in the primary design phase is to focus on a method of assessment that detects and evaluates the potential risks experienced by the operative when faced with these types of physical injuries. The method of assessment will improve the process design identifying potential ergonomic improvements from various design alternatives or activities undertaken as part of the cycle of continuous improvement throughout the differing phases of the product life cycle. Methodology/Principal Findings This paper presents a novel postural assessment method (NERPA) fit for product-process design, which was developed with the help of a digital human model together with a 3D CAD tool, which is widely used in the aeronautic and automotive industries. The power of 3D visualization and the possibility of studying the actual assembly sequence in a virtual environment can allow the functional performance of the parts to be addressed. Such tools can also provide us with an ergonomic workstation design, together with a competitive advantage in the assembly process. Conclusions The method developed was used in the design of six production lines, studying 240 manual assembly operations and improving 21 of them. This study demonstrated the proposed method’s usefulness and found statistically significant differences in the evaluations of the proposed method and the widely used Rapid Upper Limb Assessment (RULA) method. PMID:23977340

A Comparison of Methods to Test for Mediation in Multisite Experiments

ERIC Educational Resources Information Center

Pituch, Keenan A.; Whittaker, Tiffany A.; Stapleton, Laura M.

2005-01-01

A Monte Carlo study extended the research of MacKinnon, Lockwood, Hoffman, West, and Sheets (2002) for single-level designs by examining the statistical performance of four methods to test for mediation in a multilevel experimental design. The design studied was a two-group experiment that was replicated across several sites, included a single…

A Proposal for the use of the Consortium Method in the Design-build system

NASA Astrophysics Data System (ADS)

Miyatake, Ichiro; Kudo, Masataka; Kawamata, Hiroyuki; Fueta, Toshiharu

In view of the necessity for efficient implementation of public works projects, it is expected to utilize advanced technical skills of private firms, for the purpose of reducing project costs, improving performance and functions of construction objects, and reducing work periods, etc. The design-build system is a method to order design and construction as a single contract, including design of structural forms and main specifications of the construction object. This is a system in which high techniques of private firms can be utilized, as a means to ensure qualities of design and construction, rational design, and efficiency of the project. The objective of this study is to examine the use of a method to form a consortium of civil engineering consultants and construction companies, as it is an issue related to the implementation of the design-build method. Furthermore, by studying various forms of consortiums to be introduced in future, it proposes procedural items required to utilize this method, during the bid and after signing a contract, such as the estimate submission from the civil engineering consultants etc.

Methods to control for unmeasured confounding in pharmacoepidemiology: an overview.

PubMed

Uddin, Md Jamal; Groenwold, Rolf H H; Ali, Mohammed Sanni; de Boer, Anthonius; Roes, Kit C B; Chowdhury, Muhammad A B; Klungel, Olaf H

2016-06-01

Background Unmeasured confounding is one of the principal problems in pharmacoepidemiologic studies. Several methods have been proposed to detect or control for unmeasured confounding either at the study design phase or the data analysis phase. Aim of the Review To provide an overview of commonly used methods to detect or control for unmeasured confounding and to provide recommendations for proper application in pharmacoepidemiology. Methods/Results Methods to control for unmeasured confounding in the design phase of a study are case only designs (e.g., case-crossover, case-time control, self-controlled case series) and the prior event rate ratio adjustment method. Methods that can be applied in the data analysis phase include, negative control method, perturbation variable method, instrumental variable methods, sensitivity analysis, and ecological analysis. A separate group of methods are those in which additional information on confounders is collected from a substudy. The latter group includes external adjustment, propensity score calibration, two-stage sampling, and multiple imputation. Conclusion As the performance and application of the methods to handle unmeasured confounding may differ across studies and across databases, we stress the importance of using both statistical evidence and substantial clinical knowledge for interpretation of the study results.

Using Epidemiologic Methods to Test Hypotheses regarding Causal Influences on Child and Adolescent Mental Disorders

ERIC Educational Resources Information Center

Lahey, Benjamin B.; D'Onofrio, Brian M.; Waldman, Irwin D.

2009-01-01

Epidemiology uses strong sampling methods and study designs to test refutable hypotheses regarding the causes of important health, mental health, and social outcomes. Epidemiologic methods are increasingly being used to move developmental psychopathology from studies that catalogue correlates of child and adolescent mental health to designs that…

A Mixed Methods Portrait of Urban Instrumental Music Teaching

ERIC Educational Resources Information Center

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.…

Mixed methods research design for pragmatic psychoanalytic studies.

PubMed

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.

Implementing Quality Criteria in Designing and Conducting a Sequential Quan [right arrow] Qual Mixed Methods Study of Student Engagement with Learning Applied Research Methods Online

ERIC Educational Resources Information Center

Ivankova, Nataliya V.

2014-01-01

In spite of recent methodological developments related to quality assurance in mixed methods research, practical examples of how to implement quality criteria in designing and conducting sequential QUAN [right arrow] QUAL mixed methods studies to ensure the process is systematic and rigorous remain scarce. This article discusses a three-step…

Design and Analysis of a Subcritical Airfoil for High Altitude, Long Endurance Missions.

DTIC Science & Technology

1982-12-01

Airfoil Design and Analysis Method ......... .... 61 Appendix D: Boundary Layer Analysis Method ............. ... 81 Appendix E: Detailed Results ofr...attack. Computer codes designed by Richard Eppler were used for this study. The airfoil was anlayzed by using a viscous effects analysis program...inverse program designed by Eppler (Ref 5) was used in this study to accomplish this part. The second step involved the analysis of the airfoil under

Comparison of several asphalt design methods.

DOT National Transportation Integrated Search

1998-01-01

This laboratory study compared several methods of selecting the optimum asphalt content of surface mixes. Six surface mixes were tested using the 50-blow Marshall design, the 75-blow Marshall design, two brands of SHRP gyratory compactors, and the U....

Axisymmetric inlet minimum weight design method

NASA Technical Reports Server (NTRS)

Nadell, Shari-Beth

1995-01-01

An analytical method for determining the minimum weight design of an axisymmetric supersonic inlet has been developed. The goal of this method development project was to improve the ability to predict the weight of high-speed inlets in conceptual and preliminary design. The initial model was developed using information that was available from inlet conceptual design tools (e.g., the inlet internal and external geometries and pressure distributions). Stiffened shell construction was assumed. Mass properties were computed by analyzing a parametric cubic curve representation of the inlet geometry. Design loads and stresses were developed at analysis stations along the length of the inlet. The equivalent minimum structural thicknesses for both shell and frame structures required to support the maximum loads produced by various load conditions were then determined. Preliminary results indicated that inlet hammershock pressures produced the critical design load condition for a significant portion of the inlet. By improving the accuracy of inlet weight predictions, the method will improve the fidelity of propulsion and vehicle design studies and increase the accuracy of weight versus cost studies.

Consumers' Kansei Needs Clustering Method for Product Emotional Design Based on Numerical Design Structure Matrix and Genetic Algorithms.

PubMed

Yang, Yan-Pu; Chen, Deng-Kai; Gu, Rong; Gu, Yu-Feng; Yu, Sui-Huai

2016-01-01

Consumers' Kansei needs reflect their perception about a product and always consist of a large number of adjectives. Reducing the dimension complexity of these needs to extract primary words not only enables the target product to be explicitly positioned, but also provides a convenient design basis for designers engaging in design work. Accordingly, this study employs a numerical design structure matrix (NDSM) by parameterizing a conventional DSM and integrating genetic algorithms to find optimum Kansei clusters. A four-point scale method is applied to assign link weights of every two Kansei adjectives as values of cells when constructing an NDSM. Genetic algorithms are used to cluster the Kansei NDSM and find optimum clusters. Furthermore, the process of the proposed method is presented. The details of the proposed approach are illustrated using an example of electronic scooter for Kansei needs clustering. The case study reveals that the proposed method is promising for clustering Kansei needs adjectives in product emotional design.

Consumers' Kansei Needs Clustering Method for Product Emotional Design Based on Numerical Design Structure Matrix and Genetic Algorithms

PubMed Central

Chen, Deng-kai; Gu, Rong; Gu, Yu-feng; Yu, Sui-huai

2016-01-01

Consumers' Kansei needs reflect their perception about a product and always consist of a large number of adjectives. Reducing the dimension complexity of these needs to extract primary words not only enables the target product to be explicitly positioned, but also provides a convenient design basis for designers engaging in design work. Accordingly, this study employs a numerical design structure matrix (NDSM) by parameterizing a conventional DSM and integrating genetic algorithms to find optimum Kansei clusters. A four-point scale method is applied to assign link weights of every two Kansei adjectives as values of cells when constructing an NDSM. Genetic algorithms are used to cluster the Kansei NDSM and find optimum clusters. Furthermore, the process of the proposed method is presented. The details of the proposed approach are illustrated using an example of electronic scooter for Kansei needs clustering. The case study reveals that the proposed method is promising for clustering Kansei needs adjectives in product emotional design. PMID:27630709

Hybrid PV/diesel solar power system design using multi-level factor analysis optimization

NASA Astrophysics Data System (ADS)

Drake, Joshua P.

Solar power systems represent a large area of interest across a spectrum of organizations at a global level. It was determined that a clear understanding of current state of the art software and design methods, as well as optimization methods, could be used to improve the design methodology. Solar power design literature was researched for an in depth understanding of solar power system design methods and algorithms. Multiple software packages for the design and optimization of solar power systems were analyzed for a critical understanding of their design workflow. In addition, several methods of optimization were studied, including brute force, Pareto analysis, Monte Carlo, linear and nonlinear programming, and multi-way factor analysis. Factor analysis was selected as the most efficient optimization method for engineering design as it applied to solar power system design. The solar power design algorithms, software work flow analysis, and factor analysis optimization were combined to develop a solar power system design optimization software package called FireDrake. This software was used for the design of multiple solar power systems in conjunction with an energy audit case study performed in seven Tibetan refugee camps located in Mainpat, India. A report of solar system designs for the camps, as well as a proposed schedule for future installations was generated. It was determined that there were several improvements that could be made to the state of the art in modern solar power system design, though the complexity of current applications is significant.

A Methodology for Conducting Integrative Mixed Methods Research and Data Analyses

PubMed Central

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

Research Methods in Healthcare Epidemiology: Survey and Qualitative Research.

PubMed

Safdar, Nasia; Abbo, Lilian M; Knobloch, Mary Jo; Seo, Susan K

2016-11-01

Surveys are one of the most frequently employed study designs in healthcare epidemiology research. Generally easier to undertake and less costly than many other study designs, surveys can be invaluable to gain insights into opinions and practices in large samples and may be descriptive and/or be used to test associations. In this context, qualitative research methods may complement this study design either at the survey development phase and/or at the interpretation/extension of results stage. This methods article focuses on key considerations for designing and deploying surveys in healthcare epidemiology and antibiotic stewardship, including identification of whether or not de novo survey development is necessary, ways to optimally lay out and display a survey, denominator measurement, discussion of biases to keep in mind particularly in research using surveys, and the role of qualitative research methods to complement surveys. We review examples of surveys in healthcare epidemiology and antimicrobial stewardship and review the pros and cons of methods used. A checklist is provided to help aid design and deployment of surveys in healthcare epidemiology and antimicrobial stewardship. Infect Control Hosp Epidemiol 2016;1-6.

Research Methods in Healthcare Epidemiology: Survey and Qualitative Research

PubMed Central

Safdar, Nasia; Abbo, Lilian M.; Knobloch, Mary Jo; Seo, Susan K.

2017-01-01

Surveys are one of the most frequently employed study designs in healthcare epidemiology research. Generally easier to undertake and less costly than many other study designs, surveys can be invaluable to gain insights into opinions and practices in large samples and may be descriptive and/or be used to test associations. In this context, qualitative research methods may complement this study design either at the survey development phase and/or at the interpretation/extension of results stage. This methods article focuses on key considerations for designing and deploying surveys in healthcare epidemiology and antibiotic stewardship, including identification of whether or not de novo survey development is necessary, ways to optimally lay out and display a survey, denominator measurement, discussion of biases to keep in mind particularly in research using surveys, and the role of qualitative research methods to complement surveys. We review examples of surveys in healthcare epidemiology and antimicrobial stewardship and review the pros and cons of methods used. A checklist is provided to help aid design and deployment of surveys in healthcare epidemiology and antimicrobial stewardship. PMID:27514583

The Innovation Blaze-Method of Development Professional Thinking Designers in the Modern Higher Education

ERIC Educational Resources Information Center

Alekseeva, Irina V.; Barsukova, Natalia I.; Pallotta, Valentina I.; Skovorodnikova, Nadia A.

2017-01-01

This article proved the urgency of the problem of development of professional thinking of students studying design in modern conditions of higher education. The authors substantiate for the need of an innovative Blaise-method development of professional design thinking of students in higher education. "Blaise-method" named by us in…

Comparison study on flexible pavement design using FAA (Federal Aviation Administration) and LCN (Load Classification Number) code in Ahmad Yani international airport’s runway

NASA Astrophysics Data System (ADS)

Santoso, S. E.; Sulistiono, D.; Mawardi, A. F.

2017-11-01

FAA code for airport design has been broadly used by Indonesian Ministry of Aviation since decades ago. However, there is not much comprehensive study about its relevance and efficiency towards current situation in Indonesia. Therefore, a further comparison study on flexible pavement design for airport runway using comparable method has become essential. The main focus of this study is to compare which method between FAA and LCN that offer the most efficient and effective way in runway pavement planning. The comparative methods in this study mainly use the variety of variable approach. FAA code for instance, will use the approach on the aircraft’s maximum take-off weight and annual departure. Whilst LCN code use the variable of equivalent single wheel load and tire pressure. Based on the variables mentioned above, a further classification and rated method will be used to determine which code is best implemented. According to the analysis, it is clear that FAA method is the most effective way to plan runway design in Indonesia with consecutively total pavement thickness of 127cm and LCN method total pavement thickness of 70cm. Although, FAA total pavement is thicker that LCN its relevance towards sustainable and pristine condition in the future has become an essential aspect to consider in design and planning.

How Do High School Students Solve Probability Problems? A Mixed Methods Study on Probabilistic Reasoning

ERIC Educational Resources Information Center

Heyvaert, Mieke; Deleye, Maarten; Saenen, Lore; Van Dooren, Wim; Onghena, Patrick

2018-01-01

When studying a complex research phenomenon, a mixed methods design allows to answer a broader set of research questions and to tap into different aspects of this phenomenon, compared to a monomethod design. This paper reports on how a sequential equal status design (QUAN ? QUAL) was used to examine students' reasoning processes when solving…

An Analysis of Social, Literary and Technological Sources Used by Classroom Teachers in Social Studies Courses

ERIC Educational Resources Information Center

Fidan, Nuray Kurtdede; Ergün, Mustafa

2016-01-01

In this study, social, literary and technological sources used by classroom teachers in social studies courses are analyzed in terms of frequency. The study employs mixed methods research and is designed following the convergent parallel design. In the qualitative part of the study, phenomenological method was used and in the quantitative…

Connecting the Dots and Merging Meaning: Using Mixed Methods to Study Primary Care Delivery Transformation

PubMed Central

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

2013-01-01

Objective. 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. Data Source/Study Setting. 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. Study Design. Convergent case study mixed methods design. Data Collection/Extraction Methods. 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. Principal Findings. 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. Conclusions. Mixed methods are useful in studying practice transformation. Challenges exist but can be overcome with careful planning and persistence. PMID:24279836

The design of scenario-based training from the resilience engineering perspective: a study with grid electricians.

PubMed

Saurin, Tarcisio Abreu; Wachs, Priscila; Righi, Angela Weber; Henriqson, Eder

2014-07-01

Although scenario-based training (SBT) can be an effective means to help workers develop resilience skills, it has not yet been analyzed from the resilience engineering (RE) perspective. This study introduces a five-stage method for designing SBT from the RE view: (a) identification of resilience skills, work constraints and actions for re-designing the socio-technical system; (b) design of template scenarios, allowing the simulation of the work constraints and the use of resilience skills; (c) design of the simulation protocol, which includes briefing, simulation and debriefing; (d) implementation of both scenarios and simulation protocol; and (e) evaluation of the scenarios and simulation protocol. It is reported how the method was applied in an electricity distribution company, in order to train grid electricians. The study was framed as an application of design science research, and five research outputs are discussed: method, constructs, model of the relationships among constructs, instantiations of the method, and theory building. Concerning the last output, the operationalization of the RE perspective on three elements of SBT is presented: identification of training objectives; scenario design; and debriefing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Study of Method for Designing the Power and the Capacitance of Fuel Cells and Electric Double-Layer Capacitors of Hybrid Railway Vehicle

NASA Astrophysics Data System (ADS)

Takizawa, Kenji; Kondo, Keiichiro

A hybrid railway traction system with fuel cells (FCs) and electric double layer-capacitors (EDLCs) is discussed in this paper. This system can save FC costs and absorb the regenerative energy. A method for designing FCs and EDLCs on the basis of the output power and capacitance, respectively, has not been reported, even though their design is one of the most important technical issues encountered in the design of hybrid railway vehicles. Such design method is presented along with a train load profile and an energy management strategy. The design results obtained using the proposed method are verified by performing numerical simulations of a running train. These results reveal that the proposed method for designing the EDLCs and FCs on the basis of the capacitance and power, respectively, and by using a method for controlling the EDLC voltage is sufficiently effective in designing efficient EDLCs and FCs of hybrid railway traction systems.

Study/experimental/research design: much more than statistics.

PubMed

Knight, Kenneth L

2010-01-01

The purpose of study, experimental, or research design in scientific manuscripts has changed significantly over the years. It has evolved from an explanation of the design of the experiment (ie, data gathering or acquisition) to an explanation of the statistical analysis. This practice makes "Methods" sections hard to read and understand. To clarify the difference between study design and statistical analysis, to show the advantages of a properly written study design on article comprehension, and to encourage authors to correctly describe study designs. The role of study design is explored from the introduction of the concept by Fisher through modern-day scientists and the AMA Manual of Style. At one time, when experiments were simpler, the study design and statistical design were identical or very similar. With the complex research that is common today, which often includes manipulating variables to create new variables and the multiple (and different) analyses of a single data set, data collection is very different than statistical design. Thus, both a study design and a statistical design are necessary. Scientific manuscripts will be much easier to read and comprehend. A proper experimental design serves as a road map to the study methods, helping readers to understand more clearly how the data were obtained and, therefore, assisting them in properly analyzing the results.

Divertor target shape optimization in realistic edge plasma geometry

NASA Astrophysics Data System (ADS)

Dekeyser, W.; Reiter, D.; Baelmans, M.

2014-07-01

Tokamak divertor design for next-step fusion reactors heavily relies on numerical simulations of the plasma edge. Currently, the design process is mainly done in a forward approach, where the designer is strongly guided by his experience and physical intuition in proposing divertor shapes, which are then thoroughly assessed by numerical computations. On the other hand, automated design methods based on optimization have proven very successful in the related field of aerodynamic design. By recasting design objectives and constraints into the framework of a mathematical optimization problem, efficient forward-adjoint based algorithms can be used to automatically compute the divertor shape which performs the best with respect to the selected edge plasma model and design criteria. In the past years, we have extended these methods to automated divertor target shape design, using somewhat simplified edge plasma models and geometries. In this paper, we build on and extend previous work to apply these shape optimization methods for the first time in more realistic, single null edge plasma and divertor geometry, as commonly used in current divertor design studies. In a case study with JET-like parameters, we show that the so-called one-shot method is very effective is solving divertor target design problems. Furthermore, by detailed shape sensitivity analysis we demonstrate that the development of the method already at the present state provides physically plausible trends, allowing to achieve a divertor design with an almost perfectly uniform power load for our particular choice of edge plasma model and design criteria.

Shape design sensitivity analysis using domain information

NASA Technical Reports Server (NTRS)

Seong, Hwal-Gyeong; Choi, Kyung K.

1985-01-01

A numerical method for obtaining accurate shape design sensitivity information for built-up structures is developed and demonstrated through analysis of examples. The basic character of the finite element method, which gives more accurate domain information than boundary information, is utilized for shape design sensitivity improvement. A domain approach for shape design sensitivity analysis of built-up structures is derived using the material derivative idea of structural mechanics and the adjoint variable method of design sensitivity analysis. Velocity elements and B-spline curves are introduced to alleviate difficulties in generating domain velocity fields. The regularity requirements of the design velocity field are studied.

Dakota, a multilevel parallel object-oriented framework for design optimization, parameter estimation, uncertainty quantification, and sensitivity analysis :

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

Adams, Brian M.; Ebeida, Mohamed Salah; Eldred, Michael S.

The Dakota (Design Analysis Kit for Optimization and Terascale Applications) toolkit provides a exible and extensible interface between simulation codes and iterative analysis methods. Dakota contains algorithms for optimization with gradient and nongradient-based methods; uncertainty quanti cation with sampling, reliability, and stochastic expansion methods; parameter estimation with nonlinear least squares methods; and sensitivity/variance analysis with design of experiments and parameter study methods. These capabilities may be used on their own or as components within advanced strategies such as surrogate-based optimization, mixed integer nonlinear programming, or optimization under uncertainty. By employing object-oriented design to implement abstractions of the key components requiredmore » for iterative systems analyses, the Dakota toolkit provides a exible and extensible problem-solving environment for design and performance analysis of computational models on high performance computers. This report serves as a user's manual for the Dakota software and provides capability overviews and procedures for software execution, as well as a variety of example studies.« less

Incorporating Servqual-QFD with Taguchi Design for optimizing service quality design

NASA Astrophysics Data System (ADS)

Arbi Hadiyat, M.

2018-03-01

Deploying good service design in service companies has been updated issue in improving customer satisfaction, especially based on the level of service quality measured by Parasuraman’s SERVQUAL. Many researchers have been proposing methods in designing the service, and some of them are based on engineering viewpoint, especially by implementing the QFD method or even using robust Taguchi method. The QFD method would found the qualitative solution by generating the “how’s”, while Taguchi method gives more quantitative calculation in optimizing best solution. However, incorporating both QFD and Taguchi has been done in this paper and yields better design process. The purposes of this research is to evaluate the incorporated methods by implemented it to a case study, then analyze the result and see the robustness of those methods to customer perception of service quality. Started by measuring service attributes using SERVQUAL and find the improvement with QFD, the deployment of QFD solution then generated by defining Taguchi factors levels and calculating the Signal-to-noise ratio in its orthogonal array, and optimized Taguchi response then found. A case study was given for designing service in local bank. Afterward, the service design obtained from previous analysis was then evaluated and shows that it was still meet the customer satisfaction. Incorporating QFD and Taguchi has performed well and can be adopted and developed for another research for evaluating the robustness of result.

Design elements in implementation research: a structured review of child welfare and child mental health studies.

PubMed

Landsverk, John; Brown, C Hendricks; Rolls Reutz, Jennifer; Palinkas, Lawrence; Horwitz, Sarah McCue

2011-01-01

Implementation science is an emerging field of research with considerable penetration in physical medicine and less in the fields of mental health and social services. There remains a lack of consensus on methodological approaches to the study of implementation processes and tests of implementation strategies. This paper addresses the need for methods development through a structured review that describes design elements in nine studies testing implementation strategies for evidence-based interventions addressing mental health problems of children in child welfare and child mental health settings. Randomized trial designs were dominant with considerable use of mixed method designs in the nine studies published since 2005. The findings are discussed in reference to the limitations of randomized designs in implementation science and the potential for use of alternative designs.

Sample size determination for mediation analysis of longitudinal data.

PubMed

Pan, Haitao; Liu, Suyu; Miao, Danmin; Yuan, Ying

2018-03-27

Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design. To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product method and the bootstrap method. Among the three methods of testing the mediation effects, Sobel's method required the largest sample size to achieve 80% power. Bootstrapping and the distribution of the product method performed similarly and were more powerful than Sobel's method, as reflected by the relatively smaller sample sizes. For all three methods, the sample size required to achieve 80% power depended on the value of the ICC (i.e., within-subject correlation). A larger value of ICC typically required a larger sample size to achieve 80% power. Simulation results also illustrated the advantage of the longitudinal study design. The sample size tables for most encountered scenarios in practice have also been published for convenient use. Extensive simulations study showed that the distribution of the product method and bootstrapping method have superior performance to the Sobel's method, but the product method was recommended to use in practice in terms of less computation time load compared to the bootstrapping method. A R package has been developed for the product method of sample size determination in mediation longitudinal study design.

Scale Development and Initial Tests of the Multidimensional Complex Adaptive Leadership Scale for School Principals: An Exploratory Mixed Method Study

ERIC Educational Resources Information Center

Özen, Hamit; Turan, Selahattin

2017-01-01

This study was designed to develop the scale of the Complex Adaptive Leadership for School Principals (CAL-SP) and examine its psychometric properties. This was an exploratory mixed method research design (ES-MMD). Both qualitative and quantitative methods were used to develop and assess psychometric properties of the questionnaire. This study…

Core Professionalism Education in Surgery: A Systematic Review

PubMed Central

Sarıoğlu Büke, Akile; Karabilgin Öztürkçü, Özlem Sürel; Yılmaz, Yusuf; Sayek, İskender

2018-01-01

Background: Professionalism education is one of the major elements of surgical residency education. Aims: To evaluate the studies on core professionalism education programs in surgical professionalism education. Study Design: Systematic review. Methods: This systematic literature review was performed to analyze core professionalism programs for surgical residency education published in English with at least three of the following features: program developmental model/instructional design method, aims and competencies, methods of teaching, methods of assessment, and program evaluation model or method. A total of 27083 articles were retrieved using EBSCOHOST, PubMed, Science Direct, Web of Science, and manual search. Results: Eight articles met the selection criteria. The instructional design method was presented in only one article, which described the Analysis, Design, Development, Implementation, and Evaluation model. Six articles were based on the Accreditation Council for Graduate Medical Education criterion, although there was significant variability in content. The most common teaching method was role modeling with scenario- and case-based learning. A wide range of assessment methods for evaluating professionalism education were reported. The Kirkpatrick model was reported in one article as a method for program evaluation. Conclusion: It is suggested that for a core surgical professionalism education program, developmental/instructional design model, aims and competencies, content, teaching methods, assessment methods, and program evaluation methods/models should be well defined, and the content should be comparable. PMID:29553464

Probabilistic Methods for Uncertainty Propagation Applied to Aircraft Design

NASA Technical Reports Server (NTRS)

Green, Lawrence L.; Lin, Hong-Zong; Khalessi, Mohammad R.

2002-01-01

Three methods of probabilistic uncertainty propagation and quantification (the method of moments, Monte Carlo simulation, and a nongradient simulation search method) are applied to an aircraft analysis and conceptual design program to demonstrate design under uncertainty. The chosen example problems appear to have discontinuous design spaces and thus these examples pose difficulties for many popular methods of uncertainty propagation and quantification. However, specific implementation features of the first and third methods chosen for use in this study enable successful propagation of small uncertainties through the program. Input uncertainties in two configuration design variables are considered. Uncertainties in aircraft weight are computed. The effects of specifying required levels of constraint satisfaction with specified levels of input uncertainty are also demonstrated. The results show, as expected, that the designs under uncertainty are typically heavier and more conservative than those in which no input uncertainties exist.

Evaluating the utility of two gestural discomfort evaluation methods

PubMed Central

Son, Minseok; Jung, Jaemoon; Park, Woojin

2017-01-01

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

Mixed methods research: a design for emergency care research?

PubMed

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.

Optimization Design of Minimum Total Resistance Hull Form Based on CFD Method

NASA Astrophysics Data System (ADS)

Zhang, Bao-ji; Zhang, Sheng-long; Zhang, Hui

2018-06-01

In order to reduce the resistance and improve the hydrodynamic performance of a ship, two hull form design methods are proposed based on the potential flow theory and viscous flow theory. The flow fields are meshed using body-fitted mesh and structured grids. The parameters of the hull modification function are the design variables. A three-dimensional modeling method is used to alter the geometry. The Non-Linear Programming (NLP) method is utilized to optimize a David Taylor Model Basin (DTMB) model 5415 ship under the constraints, including the displacement constraint. The optimization results show an effective reduction of the resistance. The two hull form design methods developed in this study can provide technical support and theoretical basis for designing green ships.

Participatory design of healthcare technology with children.

PubMed

Sims, Tara

2018-02-12

Purpose There are many frameworks and methods for involving children in design research. Human-Computer Interaction provides rich methods for involving children when designing technologies. The paper aims to discuss these issues. Design/methodology/approach This paper examines various approaches to involving children in design, considering whether users view children as study objects or active participants. Findings The BRIDGE method is a sociocultural approach to product design that views children as active participants, enabling them to contribute to the design process as competent and resourceful partners. An example is provided, in which BRIDGE was successfully applied to developing upper limb prostheses with children. Originality/value Approaching design in this way can provide children with opportunities to develop social, academic and design skills and to develop autonomy.

Similitude design for the vibration problems of plates and shells: A review

NASA Astrophysics Data System (ADS)

Zhu, Yunpeng; Wang, You; Luo, Zhong; Han, Qingkai; Wang, Deyou

2017-06-01

Similitude design plays a vital role in the analysis of vibration and shock problems encountered in large engineering equipment. Similitude design, including dimensional analysis and governing equation method, is founded on the dynamic similitude theory. This study reviews the application of similitude design methods in engineering practice and summarizes the major achievements of the dynamic similitude theory in structural vibration and shock problems in different fields, including marine structures, civil engineering structures, and large power equipment. This study also reviews the dynamic similitude design methods for thin-walled and composite material plates and shells, including the most recent work published by the authors. Structure sensitivity analysis is used to evaluate the scaling factors to attain accurate distorted scaling laws. Finally, this study discusses the existing problems and the potential of the dynamic similitude theory for the analysis of vibration and shock problems of structures.

A direct approach to the design of linear multivariable systems

NASA Technical Reports Server (NTRS)

Agrawal, B. L.

1974-01-01

Design of multivariable systems is considered and design procedures are formulated in the light of the most recent work on model matching. The word model matching is used exclusively to mean matching the input-output behavior of two systems. The term is used in the frequency domain to indicate the comparison of two transfer matrices containing transfer functions as elements. Design methods where non-interaction is not used as a criteria were studied. Two design methods are considered. The first method of design is based solely upon the specification of generalized error coefficients for each individual transfer function of the overall system transfer matrix. The second design method is called the pole fixing method because all the system poles are fixed at preassigned positions. The zeros of terms either above or below the diagonal are partially fixed via steady state error coefficients. The advantages and disadvantages of each method are discussed and an example is worked to demonstrate their uses. The special cases of triangular decoupling and minimum constraints are discussed.

Stochastic Methods for Aircraft Design

NASA Technical Reports Server (NTRS)

Pelz, Richard B.; Ogot, Madara

1998-01-01

The global stochastic optimization method, simulated annealing (SA), was adapted and applied to various problems in aircraft design. The research was aimed at overcoming the problem of finding an optimal design in a space with multiple minima and roughness ubiquitous to numerically generated nonlinear objective functions. SA was modified to reduce the number of objective function evaluations for an optimal design, historically the main criticism of stochastic methods. SA was applied to many CFD/MDO problems including: low sonic-boom bodies, minimum drag on supersonic fore-bodies, minimum drag on supersonic aeroelastic fore-bodies, minimum drag on HSCT aeroelastic wings, FLOPS preliminary design code, another preliminary aircraft design study with vortex lattice aerodynamics, HSR complete aircraft aerodynamics. In every case, SA provided a simple, robust and reliable optimization method which found optimal designs in order 100 objective function evaluations. Perhaps most importantly, from this academic/industrial project, technology has been successfully transferred; this method is the method of choice for optimization problems at Northrop Grumman.

Performance of bias-correction methods for exposure measurement error using repeated measurements with and without missing data.

PubMed

Batistatou, Evridiki; McNamee, Roseanne

2012-12-10

It is known that measurement error leads to bias in assessing exposure effects, which can however, be corrected if independent replicates are available. For expensive replicates, two-stage (2S) studies that produce data 'missing by design', may be preferred over a single-stage (1S) study, because in the second stage, measurement of replicates is restricted to a sample of first-stage subjects. Motivated by an occupational study on the acute effect of carbon black exposure on respiratory morbidity, we compare the performance of several bias-correction methods for both designs in a simulation study: an instrumental variable method (EVROS IV) based on grouping strategies, which had been recommended especially when measurement error is large, the regression calibration and the simulation extrapolation methods. For the 2S design, either the problem of 'missing' data was ignored or the 'missing' data were imputed using multiple imputations. Both in 1S and 2S designs, in the case of small or moderate measurement error, regression calibration was shown to be the preferred approach in terms of root mean square error. For 2S designs, regression calibration as implemented by Stata software is not recommended in contrast to our implementation of this method; the 'problematic' implementation of regression calibration although substantially improved with use of multiple imputations. The EVROS IV method, under a good/fairly good grouping, outperforms the regression calibration approach in both design scenarios when exposure mismeasurement is severe. Both in 1S and 2S designs with moderate or large measurement error, simulation extrapolation severely failed to correct for bias. Copyright © 2012 John Wiley & Sons, Ltd.

The Obstacles for the Teaching of 8th Grade TR History of Revolution and Kemalism Course According to the Constructivist Approach (An Example of Exploratory Sequential Mixed Method Design)

ERIC Educational Resources Information Center

Karademir, Yavuz; Demir, Selcuk Besir

2015-01-01

The aim of this study is to ascertain the problems social studies teachers face in the teaching of topics covered in 8th grade TRHRK Course. The study was conducted in line with explanatory sequential mixed method design, which is one of the mixed research method, was used. The study involves three phases. In the first step, exploratory process…

Statistical power calculations for mixed pharmacokinetic study designs using a population approach.

PubMed

Kloprogge, Frank; Simpson, Julie A; Day, Nicholas P J; White, Nicholas J; Tarning, Joel

2014-09-01

Simultaneous modelling of dense and sparse pharmacokinetic data is possible with a population approach. To determine the number of individuals required to detect the effect of a covariate, simulation-based power calculation methodologies can be employed. The Monte Carlo Mapped Power method (a simulation-based power calculation methodology using the likelihood ratio test) was extended in the current study to perform sample size calculations for mixed pharmacokinetic studies (i.e. both sparse and dense data collection). A workflow guiding an easy and straightforward pharmacokinetic study design, considering also the cost-effectiveness of alternative study designs, was used in this analysis. Initially, data were simulated for a hypothetical drug and then for the anti-malarial drug, dihydroartemisinin. Two datasets (sampling design A: dense; sampling design B: sparse) were simulated using a pharmacokinetic model that included a binary covariate effect and subsequently re-estimated using (1) the same model and (2) a model not including the covariate effect in NONMEM 7.2. Power calculations were performed for varying numbers of patients with sampling designs A and B. Study designs with statistical power >80% were selected and further evaluated for cost-effectiveness. The simulation studies of the hypothetical drug and the anti-malarial drug dihydroartemisinin demonstrated that the simulation-based power calculation methodology, based on the Monte Carlo Mapped Power method, can be utilised to evaluate and determine the sample size of mixed (part sparsely and part densely sampled) study designs. The developed method can contribute to the design of robust and efficient pharmacokinetic studies.

Mixed Methods Research Designs in Counseling Psychology

ERIC Educational Resources Information Center

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…

[Comparison of two algorithms for development of design space-overlapping method and probability-based method].

PubMed

Shao, Jing-Yuan; Qu, Hai-Bin; Gong, Xing-Chu

2018-05-01

In this work, two algorithms (overlapping method and the probability-based method) for design space calculation were compared by using the data collected from extraction process of Codonopsis Radix as an example. In the probability-based method, experimental error was simulated to calculate the probability of reaching the standard. The effects of several parameters on the calculated design space were studied, including simulation number, step length, and the acceptable probability threshold. For the extraction process of Codonopsis Radix, 10 000 times of simulation and 0.02 for the calculation step length can lead to a satisfactory design space. In general, the overlapping method is easy to understand, and can be realized by several kinds of commercial software without coding programs, but the reliability of the process evaluation indexes when operating in the design space is not indicated. Probability-based method is complex in calculation, but can provide the reliability to ensure that the process indexes can reach the standard within the acceptable probability threshold. In addition, there is no probability mutation in the edge of design space by probability-based method. Therefore, probability-based method is recommended for design space calculation. Copyright© by the Chinese Pharmaceutical Association.

Anthropometric Procedures for Protective Equipment Sizing and Design

PubMed Central

Hsiao, Hongwei

2015-01-01

Objectives This article presented four anthropometric theories (univariate, bivariate/probability distribution, multivariate, and shape-based methods) for protective equipment design decisions. Background While the significance of anthropometric information for product design is well recognized, designers continue to face challenges in selecting efficient anthropometric data processing methods and translating the acquired information into effective product designs. Methods For this study, 100 farm tractor operators, 3,718 respirator users, 951 firefighters, and 816 civilian workers participated in four studies on the design of tractor roll-over protective structures (ROPS), respirator test panels, fire truck cabs, and fall-arrest harnesses, respectively. Their anthropometry and participant-equipment interfaces were evaluated. Results Study 1 showed a need to extend the 90-cm vertical clearance for tractor ROPS in the current industrial standards to 98.3 to 101.3 cm. Study 2 indicated that current respirator test panel would have excluded 10% of the male firefighter population; a systematic adjustment to the boundaries of test panel cells was suggested. Study 3 provided 24 principal component analysis-based firefighter body models to facilitate fire truck cab design. Study 4 developed an improved gender-based fall-arrest harness sizing scheme to supplant the current unisex system. Conclusions This article presented four anthropometric approaches and a six-step design paradigm for ROPS, respirator test panel, fire truck cab, and fall-arrest harness applications, which demonstrated anthropometric theories and practices for defining protective equipment fit and sizing schemes. Applications The study provided a basis for equipment designers, standards writers, and industry manufacturers to advance anthropometric applications for product design and improve product efficacy. PMID:23516791

Controlling lightwave in Riemann space by merging geometrical optics with transformation optics.

PubMed

Liu, Yichao; Sun, Fei; He, Sailing

2018-01-11

In geometrical optical design, we only need to choose a suitable combination of lenses, prims, and mirrors to design an optical path. It is a simple and classic method for engineers. However, people cannot design fantastical optical devices such as invisibility cloaks, optical wormholes, etc. by geometrical optics. Transformation optics has paved the way for these complicated designs. However, controlling the propagation of light by transformation optics is not a direct design process like geometrical optics. In this study, a novel mixed method for optical design is proposed which has both the simplicity of classic geometrical optics and the flexibility of transformation optics. This mixed method overcomes the limitations of classic optical design; at the same time, it gives intuitive guidance for optical design by transformation optics. Three novel optical devices with fantastic functions have been designed using this mixed method, including asymmetrical transmissions, bidirectional focusing, and bidirectional cloaking. These optical devices cannot be implemented by classic optics alone and are also too complicated to be designed by pure transformation optics. Numerical simulations based on both the ray tracing method and full-wave simulation method are carried out to verify the performance of these three optical devices.

Role of the Direct Teaching Method in the Academic Achievement of Students in English at the Secondary Level

ERIC Educational Resources Information Center

Hussain, Ishtiaq; Inamullah, Hafiz; Naseer-Ud-Din, Muhammad; Hafizatullah, Hafiz

2009-01-01

The major objective of this study was to determine the role of the direct teaching method in the academic achievement of students in English at the secondary level. To achieve the said objective, the "Solomon Four-Design pre-test/post-test equivalent group design" was considered to be the most useful design for this study. The pre-test…

Optimal Spatial Design of Capacity and Quantity of Rainwater Catchment Systems for Urban Flood Mitigation

NASA Astrophysics Data System (ADS)

Huang, C.; Hsu, N.

2013-12-01

This study imports Low-Impact Development (LID) technology of rainwater catchment systems into a Storm-Water runoff Management Model (SWMM) to design the spatial capacity and quantity of rain barrel for urban flood mitigation. This study proposes a simulation-optimization model for effectively searching the optimal design. In simulation method, we design a series of regular spatial distributions of capacity and quantity of rainwater catchment facilities, and thus the reduced flooding circumstances using a variety of design forms could be simulated by SWMM. Moreover, we further calculate the net benefit that is equal to subtract facility cost from decreasing inundation loss and the best solution of simulation method would be the initial searching solution of the optimization model. In optimizing method, first we apply the outcome of simulation method and Back-Propagation Neural Network (BPNN) for developing a water level simulation model of urban drainage system in order to replace SWMM which the operating is based on a graphical user interface and is hard to combine with optimization model and method. After that we embed the BPNN-based simulation model into the developed optimization model which the objective function is minimizing the negative net benefit. Finally, we establish a tabu search-based algorithm to optimize the planning solution. This study applies the developed method in Zhonghe Dist., Taiwan. Results showed that application of tabu search and BPNN-based simulation model into the optimization model not only can find better solutions than simulation method in 12.75%, but also can resolve the limitations of previous studies. Furthermore, the optimized spatial rain barrel design can reduce 72% of inundation loss according to historical flood events.

Optimal cure cycle design of a resin-fiber composite laminate

NASA Technical Reports Server (NTRS)

Hou, Jean W.; Sheen, Jeenson

1987-01-01

A unified computed aided design method was studied for the cure cycle design that incorporates an optimal design technique with the analytical model of a composite cure process. The preliminary results of using this proposed method for optimal cure cycle design are reported and discussed. The cure process of interest is the compression molding of a polyester which is described by a diffusion reaction system. The finite element method is employed to convert the initial boundary value problem into a set of first order differential equations which are solved simultaneously by the DE program. The equations for thermal design sensitivities are derived by using the direct differentiation method and are solved by the DE program. A recursive quadratic programming algorithm with an active set strategy called a linearization method is used to optimally design the cure cycle, subjected to the given design performance requirements. The difficulty of casting the cure cycle design process into a proper mathematical form is recognized. Various optimal design problems are formulated to address theses aspects. The optimal solutions of these formulations are compared and discussed.

Designing scalable product families by the radial basis function-high-dimensional model representation metamodelling technique

NASA Astrophysics Data System (ADS)

Pirmoradi, Zhila; Haji Hajikolaei, Kambiz; Wang, G. Gary

2015-10-01

Product family design is cost-efficient for achieving the best trade-off between commonalization and diversification. However, for computationally intensive design functions which are viewed as black boxes, the family design would be challenging. A two-stage platform configuration method with generalized commonality is proposed for a scale-based family with unknown platform configuration. Unconventional sensitivity analysis and information on variation in the individual variants' optimal design are used for platform configuration design. Metamodelling is employed to provide the sensitivity and variable correlation information, leading to significant savings in function calls. A family of universal electric motors is designed for product performance and the efficiency of this method is studied. The impact of the employed parameters is also analysed. Then, the proposed method is modified for obtaining higher commonality. The proposed method is shown to yield design solutions with better objective function values, allowable performance loss and higher commonality than the previously developed methods in the literature.

Comparing Impact Findings from Design-Based and Model-Based Methods: An Empirical Investigation. NCEE 2017-4026

ERIC Educational Resources Information Center

Kautz, Tim; Schochet, Peter Z.; Tilley, Charles

2017-01-01

A new design-based theory has recently been developed to estimate impacts for randomized controlled trials (RCTs) and basic quasi-experimental designs (QEDs) for a wide range of designs used in social policy research (Imbens & Rubin, 2015; Schochet, 2016). These methods use the potential outcomes framework and known features of study designs…

Novel methodology for wide-ranged multistage morphing waverider based on conical theory

NASA Astrophysics Data System (ADS)

Liu, Zhen; Liu, Jun; Ding, Feng; Xia, Zhixun

2017-11-01

This study proposes the wide-ranged multistage morphing waverider design method. The flow field structure and aerodynamic characteristics of multistage waveriders are also analyzed. In this method, the multistage waverider is generated in the same conical flowfield, which contains a free-stream surface and different compression-stream surfaces. The obtained results show that the introduction of the multistage waverider design method can solve the problem of aerodynamic performance deterioration in the off-design state and allow the vehicle to always maintain the optimal flight state. The multistage waverider design method, combined with transfiguration flight strategy, can lead to greater design flexibility and the optimization of hypersonic wide-ranged waverider vehicles.

Federal truck size and weight policy : looking beyond the comprehensive truck size and weight study : Irvine, California, May 10-11, 2000

DOT National Transportation Integrated Search

1997-05-01

This document presents a series of five design examples illustrating the principles and methods of geotechnical earthquake engineering and seismic design for highway facilities. These principles and methods are described in Volume I - Design Principl...

FODEM: A Multi-Threaded Research and Development Method for Educational Technology

ERIC Educational Resources Information Center

Suhonen, Jarkko; de Villiers, M. Ruth; Sutinen, Erkki

2012-01-01

Formative development method (FODEM) is a multithreaded design approach that was originated to support the design and development of various types of educational technology innovations, such as learning tools, and online study programmes. The threaded and agile structure of the approach provides flexibility to the design process. Intensive…

Assessing Creative Thinking in Design-Based Learning

ERIC Educational Resources Information Center

Doppelt, Yaron

2009-01-01

Infusing creative thinking competence through the design process of authentic projects requires not only changing the teaching methods and learning environment, but also adopting new assessment methods, such as portfolio assessment. The participants in this study were 128 high school pupils who have studied MECHATRONICS from 10th to 12th grades…

Domestic Violence Assessments in the Child Advocacy Center

ERIC Educational Resources Information Center

Thackeray, Jonathan D.; Scribano, Philip V.; Rhoda, Dale

2010-01-01

Objective: This study was designed to identify the frequency, methods, and practices of universal assessments for domestic violence (DV) within child advocacy centers (CACs) and determine which factors are associated with CACs that conduct universal DV assessments. Methods: The study design was a cross-sectional, web-based survey distributed to…

Sampling design by the core-food approach for the Taiwan total diet study on veterinary drugs.

PubMed

Chen, Chien-Chih; Tsai, Ching-Lun; Chang, Chia-Chin; Ni, Shih-Pei; Chen, Yi-Tzu; Chiang, Chow-Feng

2017-06-01

The core-food (CF) approach, first adopted in the United States in the 1980s, has been widely used by many countries to assess the exposure to dietary hazards at a population level. However, the reliability of exposure estimates (C × CR) depends critically on sampling methods designed for the detected chemical concentrations (C) of each CF to match with the corresponding consumption rate (CR) estimated from the surveyed intake data. In order to reduce the uncertainty of food matching, this study presents a sampling design scheme, namely the subsample method, for the 2016 Taiwan total diet study (TDS) on veterinary drugs. We first combined the four sets of national dietary recall data that covered the entire age strata (1-65+ years), and aggregated them into 307 CFs by their similarity in nutritional values, manufacturing and cooking methods. The 40 CFs pertinent to veterinary drug residues were selected for this study, and 16 subsamples for each CF were designed by weighing their quantities in CR, product brands, manufacturing, processing and cooking methods. The calculated food matching rates of each CF from this study were 84.3-97.3%, which were higher than those obtained from many previous studies using the representative food (RF) method (53.1-57.8%). The subsample method not only considers the variety of food processing and cooking methods, but also it provides better food matching and reduces the uncertainty of exposure assessment.

Study of metallic structural design concepts for an arrow wing supersonic cruise configuration

NASA Technical Reports Server (NTRS)

Turner, M. J.; Grande, D. L.

1977-01-01

A structural design study was made, to assess the relative merits of various metallic structural concepts and materials for an advanced supersonic aircraft cruising at Mach 2.7. Preliminary studies were made to ensure compliance of the configuration with general design criteria, integrate the propulsion system with the airframe, select structural concepts and materials, and define an efficient structural arrangement. An advanced computerized structural design system was used, in conjunction with a relatively large, complex finite element model, for detailed analysis and sizing of structural members to satisfy strength and flutter criteria. A baseline aircraft design was developed for assessment of current technology. Criteria, analysis methods, and results are presented. The effect on design methods of using the computerized structural design system was appraised, and recommendations are presented concerning further development of design tools, development of materials and structural concepts, and research on basic technology.

Novel parameter-based flexure bearing design method

NASA Astrophysics Data System (ADS)

Amoedo, Simon; Thebaud, Edouard; Gschwendtner, Michael; White, David

2016-06-01

A parameter study was carried out on the design variables of a flexure bearing to be used in a Stirling engine with a fixed axial displacement and a fixed outer diameter. A design method was developed in order to assist identification of the optimum bearing configuration. This was achieved through a parameter study of the bearing carried out with ANSYS®. The parameters varied were the number and the width of the arms, the thickness of the bearing, the eccentricity, the size of the starting and ending holes, and the turn angle of the spiral. Comparison was made between the different designs in terms of axial and radial stiffness, the natural frequency, and the maximum induced stresses. Moreover, the Finite Element Analysis (FEA) was compared to theoretical results for a given design. The results led to a graphical design method which assists the selection of flexure bearing geometrical parameters based on pre-determined geometric and material constraints.

Weapon System Costing Methodology for Aircraft Airframes and Basic Structures. Volume I. Technical Volume

DTIC Science & Technology

1975-06-01

the Air Force Flight Dynamics Laboratory for use in conceptual and preliminary designs pauses of weapon system development. The methods are a...trade study method provides ai\\ iterative capability stemming from a direct interface with design synthesis programs. A detailed cost data base ;ind...system for data expmjsion is provided. The methods are designed for ease in changing cost estimating relationships and estimating coefficients

An Engineering Method of Civil Jet Requirements Validation Based on Requirements Project Principle

NASA Astrophysics Data System (ADS)

Wang, Yue; Gao, Dan; Mao, Xuming

2018-03-01

A method of requirements validation is developed and defined to meet the needs of civil jet requirements validation in product development. Based on requirements project principle, this method will not affect the conventional design elements, and can effectively connect the requirements with design. It realizes the modern civil jet development concept, which is “requirement is the origin, design is the basis”. So far, the method has been successfully applied in civil jet aircraft development in China. Taking takeoff field length as an example, the validation process and the validation method of the requirements are detailed introduced in the study, with the hope of providing the experiences to other civil jet product design.

Acoustic Treatment Design Scaling Methods. Volume 1; Overview, Results, and Recommendations

NASA Technical Reports Server (NTRS)

Kraft, R. E.; Yu, J.

1999-01-01

Scale model fan rigs that simulate new generation ultra-high-bypass engines at about 1/5-scale are achieving increased importance as development vehicles for the design of low-noise aircraft engines. Testing at small scale allows the tests to be performed in existing anechoic wind tunnels, which provides an accurate simulation of the important effects of aircraft forward motion on the noise generation. The ability to design, build, and test miniaturized acoustic treatment panels on scale model fan rigs representative of the fullscale engine provides not only a cost-savings, but an opportunity to optimize the treatment by allowing tests of different designs. The primary objective of this study was to develop methods that will allow scale model fan rigs to be successfully used as acoustic treatment design tools. The study focuses on finding methods to extend the upper limit of the frequency range of impedance prediction models and acoustic impedance measurement methods for subscale treatment liner designs, and confirm the predictions by correlation with measured data. This phase of the program had as a goal doubling the upper limit of impedance measurement from 6 kHz to 12 kHz. The program utilizes combined analytical and experimental methods to achieve the objectives.

Outcome-Dependent Sampling Design and Inference for Cox's Proportional Hazards Model.

PubMed

Yu, Jichang; Liu, Yanyan; Cai, Jianwen; Sandler, Dale P; Zhou, Haibo

2016-11-01

We propose a cost-effective outcome-dependent sampling design for the failure time data and develop an efficient inference procedure for data collected with this design. To account for the biased sampling scheme, we derive estimators from a weighted partial likelihood estimating equation. The proposed estimators for regression parameters are shown to be consistent and asymptotically normally distributed. A criteria that can be used to optimally implement the ODS design in practice is proposed and studied. The small sample performance of the proposed method is evaluated by simulation studies. The proposed design and inference procedure is shown to be statistically more powerful than existing alternative designs with the same sample sizes. We illustrate the proposed method with an existing real data from the Cancer Incidence and Mortality of Uranium Miners Study.

Sample size for post-marketing safety studies based on historical controls.

PubMed

Wu, Yu-te; Makuch, Robert W

2010-08-01

As part of a drug's entire life cycle, post-marketing studies are an important part in the identification of rare, serious adverse events. Recently, the US Food and Drug Administration (FDA) has begun to implement new post-marketing safety mandates as a consequence of increased emphasis on safety. The purpose of this research is to provide exact sample size formula for the proposed hybrid design, based on a two-group cohort study with incorporation of historical external data. Exact sample size formula based on the Poisson distribution is developed, because the detection of rare events is our outcome of interest. Performance of exact method is compared to its approximate large-sample theory counterpart. The proposed hybrid design requires a smaller sample size compared to the standard, two-group prospective study design. In addition, the exact method reduces the number of subjects required in the treatment group by up to 30% compared to the approximate method for the study scenarios examined. The proposed hybrid design satisfies the advantages and rationale of the two-group design with smaller sample sizes generally required. 2010 John Wiley & Sons, Ltd.

Application of the CSCM method to the design of wedge cavities. [Conservative Supra Characteristic Method

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Nystrom, G. A.; Bardina, J.; Lombard, C. K.

1987-01-01

This paper describes the application of the conservative supra characteristic method (CSCM) to predict the flow around two-dimensional slot injection cooled cavities in hypersonic flow. Seven different numerical solutions are presented that model three different experimental designs. The calculations manifest outer flow conditions including the effects of nozzle/lip geometry, angle of attack, nozzle inlet conditions, boundary and shear layer growth and turbulance on the surrounding flow. The calculations were performed for analysis prior to wind tunnel testing for sensitivity studies early in the design process. Qualitative and quantitative understanding of the flows for each of the cavity designs and design recommendations are provided. The present paper demonstrates the ability of numerical schemes, such as the CSCM method, to play a significant role in the design process.

The Health Services Mobility Study Method of Task Analysis and Curriculum Design. Research Report No. 11. Volume 3: Using the Computer to Develop Job Ladders.

ERIC Educational Resources Information Center

Gilpatrick, Eleanor

This document is volume 3 of a four-volume report which describes the components of the Health Services Mobility Study (HSMS) method of task analysis, job ladder design, and curriculum development. Divided into four chapters, volume 3 is a manual for using HSMS computer based statistical procedures to design job structures and job ladders. Chapter…

Practicing Accounting Profession Criterial Skills in the Classroom: A Study of Collaborative Testing and the Impact on Final Exam Scores

ERIC Educational Resources Information Center

VanderLaan, Ski R.

2010-01-01

This mixed methods study (Creswell, 2008) was designed to test the influence of collaborative testing on learning using a quasi-experimental approach. This study used a modified embedded mixed method design in which the qualitative and quantitative data, associated with the secondary questions, provided a supportive role in a study based primarily…

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

ERIC Educational Resources Information Center

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

2014-01-01

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

Structural design of composite rotor blades with consideration of manufacturability, durability, and manufacturing uncertainties

NASA Astrophysics Data System (ADS)

Li, Leihong

A modular structural design methodology for composite blades is developed. This design method can be used to design composite rotor blades with sophisticate geometric cross-sections. This design method hierarchically decomposed the highly-coupled interdisciplinary rotor analysis into global and local levels. In the global level, aeroelastic response analysis and rotor trim are conduced based on multi-body dynamic models. In the local level, variational asymptotic beam sectional analysis methods are used for the equivalent one-dimensional beam properties. Compared with traditional design methodology, the proposed method is more efficient and accurate. Then, the proposed method is used to study three different design problems that have not been investigated before. The first is to add manufacturing constraints into design optimization. The introduction of manufacturing constraints complicates the optimization process. However, the design with manufacturing constraints benefits the manufacturing process and reduces the risk of violating major performance constraints. Next, a new design procedure for structural design against fatigue failure is proposed. This procedure combines the fatigue analysis with the optimization process. The durability or fatigue analysis employs a strength-based model. The design is subject to stiffness, frequency, and durability constraints. Finally, the manufacturing uncertainty impacts on rotor blade aeroelastic behavior are investigated, and a probabilistic design method is proposed to control the impacts of uncertainty on blade structural performance. The uncertainty factors include dimensions, shapes, material properties, and service loads.

Application of Taguchi methods to dual mixture ratio propulsion system optimization for SSTO vehicles

NASA Technical Reports Server (NTRS)

Stanley, Douglas O.; Unal, Resit; Joyner, C. R.

1992-01-01

The application of advanced technologies to future launch vehicle designs would allow the introduction of a rocket-powered, single-stage-to-orbit (SSTO) launch system early in the next century. For a selected SSTO concept, a dual mixture ratio, staged combustion cycle engine that employs a number of innovative technologies was selected as the baseline propulsion system. A series of parametric trade studies are presented to optimize both a dual mixture ratio engine and a single mixture ratio engine of similar design and technology level. The effect of varying lift-off thrust-to-weight ratio, engine mode transition Mach number, mixture ratios, area ratios, and chamber pressure values on overall vehicle weight is examined. The sensitivity of the advanced SSTO vehicle to variations in each of these parameters is presented, taking into account the interaction of each of the parameters with each other. This parametric optimization and sensitivity study employs a Taguchi design method. The Taguchi method is an efficient approach for determining near-optimum design parameters using orthogonal matrices from design of experiments (DOE) theory. Using orthogonal matrices significantly reduces the number of experimental configurations to be studied. The effectiveness and limitations of the Taguchi method for propulsion/vehicle optimization studies as compared to traditional single-variable parametric trade studies is also discussed.

Improving Design Understandings and Skills through Enhanced Metacognition: Reflective Design Journals

ERIC Educational Resources Information Center

Kurt, Mustafa; Kurt, Sevinc

2017-01-01

The main aim of this study was to investigate and discover whether going through the process of reflection by keeping reflective design journals (RDJ) enhances architecture students' metacognition and whether this enhanced metacognition improves their design understandings and skills. The study was a mixed-methods design and utilised content…

A Comparison of Kernel Equating and Traditional Equipercentile Equating Methods and the Parametric Bootstrap Methods for Estimating Standard Errors in Equipercentile Equating

ERIC Educational Resources Information Center

Choi, Sae Il

2009-01-01

This study used simulation (a) to compare the kernel equating method to traditional equipercentile equating methods under the equivalent-groups (EG) design and the nonequivalent-groups with anchor test (NEAT) design and (b) to apply the parametric bootstrap method for estimating standard errors of equating. A two-parameter logistic item response…

Structural analysis at aircraft conceptual design stage

NASA Astrophysics Data System (ADS)

Mansouri, Reza

In the past 50 years, computers have helped by augmenting human efforts with tremendous pace. The aircraft industry is not an exception. Aircraft industry is more than ever dependent on computing because of a high level of complexity and the increasing need for excellence to survive a highly competitive marketplace. Designers choose computers to perform almost every analysis task. But while doing so, existing effective, accurate and easy to use classical analytical methods are often forgotten, which can be very useful especially in the early phases of the aircraft design where concept generation and evaluation demands physical visibility of design parameters to make decisions [39, 2004]. Structural analysis methods have been used by human beings since the very early civilization. Centuries before computers were invented; the pyramids were designed and constructed by Egyptians around 2000 B.C, the Parthenon was built by the Greeks, around 240 B.C, Dujiangyan was built by the Chinese. Persepolis, Hagia Sophia, Taj Mahal, Eiffel tower are only few more examples of historical buildings, bridges and monuments that were constructed before we had any advancement made in computer aided engineering. Aircraft industry is no exception either. In the first half of the 20th century, engineers used classical method and designed civil transport aircraft such as Ford Tri Motor (1926), Lockheed Vega (1927), Lockheed 9 Orion (1931), Douglas DC-3 (1935), Douglas DC-4/C-54 Skymaster (1938), Boeing 307 (1938) and Boeing 314 Clipper (1939) and managed to become airborne without difficulty. Evidencing, while advanced numerical methods such as the finite element analysis is one of the most effective structural analysis methods; classical structural analysis methods can also be as useful especially during the early phase of a fixed wing aircraft design where major decisions are made and concept generation and evaluation demands physical visibility of design parameters to make decisions. Considering the strength and limitations of both methodologies, the question to be answered in this thesis is: How valuable and compatible are the classical analytical methods in today's conceptual design environment? And can these methods complement each other? To answer these questions, this thesis investigates the pros and cons of classical analytical structural analysis methods during the conceptual design stage through the following objectives: Illustrate structural design methodology of these methods within the framework of Aerospace Vehicle Design (AVD) lab's design lifecycle. Demonstrate the effectiveness of moment distribution method through four case studies. This will be done by considering and evaluating the strength and limitation of these methods. In order to objectively quantify the limitation and capabilities of the analytical method at the conceptual design stage, each case study becomes more complex than the one before.

Design Considerations and Experimental Verification of a Rail Brake Armature Based on Linear Induction Motor Technology

NASA Astrophysics Data System (ADS)

Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

This paper describes the design considerations and experimental verification of an LIM rail brake armature. In order to generate power and maximize the braking force density despite the limited area between the armature and the rail and the limited space available for installation, we studied a design method that is suitable for designing an LIM rail brake armature; we considered adoption of a ring winding structure. To examine the validity of the proposed design method, we developed a prototype ring winding armature for the rail brakes and examined its electromagnetic characteristics in a dynamic test system with roller rigs. By repeating various tests, we confirmed that unnecessary magnetic field components, which were expected to be present under high speed running condition or when a ring winding armature was used, were not present. Further, the necessary magnetic field component and braking force attained the desired values. These studies have helped us to develop a basic design method that is suitable for designing the LIM rail brake armatures.

On extracting design principles from biology: I. Method-General answers to high-level design questions for bioinspired robots.

PubMed

Haberland, M; Kim, S

2015-02-02

When millions of years of evolution suggest a particular design solution, we may be tempted to abandon traditional design methods and copy the biological example. However, biological solutions do not often translate directly into the engineering domain, and even when they do, copying eliminates the opportunity to improve. A better approach is to extract design principles relevant to the task of interest, incorporate them in engineering designs, and vet these candidates against others. This paper presents the first general framework for determining whether biologically inspired relationships between design input variables and output objectives and constraints are applicable to a variety of engineering systems. Using optimization and statistics to generalize the results beyond a particular system, the framework overcomes shortcomings observed of ad hoc methods, particularly those used in the challenging study of legged locomotion. The utility of the framework is demonstrated in a case study of the relative running efficiency of rotary-kneed and telescoping-legged robots.

Effect Size Calculations and Single Subject Designs

ERIC Educational Resources Information Center

Olive, Melissa L.; Smith, Benjamin W.

2005-01-01

This study compared visual analyses with five alternative methods for assessing the magnitude of effect with single subject designs. Each method was successful in detecting intervention effect. When rank ordered, each method was consistent in identifying the participants with the largest effect. We recommend the use of the standard mean difference…

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

ERIC Educational Resources Information Center

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…

Treatment of Early-Onset Schizophrenia Spectrum Disorders (TEOSS): Rationale, Design, and Methods

ERIC Educational Resources Information Center

McClellan, Jon; Sikich, Linmarie; Findling, Robert L.; Frazier, Jean A.; Vitiello, Benedetto; Hlastala, Stefanie A.; Williams, Emily; Ambler, Denisse; Hunt-Harrison, Tyehimba; Maloney, Ann E.; Ritz, Louise; Anderson, Robert; Hamer, Robert M.; Lieberman, Jeffrey A.

2007-01-01

Objective: The Treatment of Early Onset Schizophrenia Spectrum Disorders Study is a publicly funded clinical trial designed to compare the therapeutic benefits, safety, and tolerability of risperidone, olanzapine, and molindone in youths with early-onset schizophrenia spectrum disorders. The rationale, design, and methods of the Treatment of Early…

Rotor design for maneuver performance

NASA Technical Reports Server (NTRS)

Berry, John D.; Schrage, Daniel

1986-01-01

A method of determining the sensitivity of helicopter maneuver performance to changes in basic rotor design parameters is developed. Maneuver performance is measured by the time required, based on a simplified rotor/helicopter performance model, to perform a series of specified maneuvers. This method identifies parameter values which result in minimum time quickly because of the inherent simplicity of the rotor performance model used. For the specific case studied, this method predicts that the minimum time required is obtained with a low disk loading and a relatively high rotor solidity. The method was developed as part of the winning design effort for the American Helicopter Society student design competition for 1984/1985.

A study of commuter airplane design optimization

NASA Technical Reports Server (NTRS)

Keppel, B. V.; Eysink, H.; Hammer, J.; Hawley, K.; Meredith, P.; Roskam, J.

1978-01-01

The usability of the general aviation synthesis program (GASP) was enhanced by the development of separate computer subroutines which can be added as a package to this assembly of computerized design methods or used as a separate subroutine program to compute the dynamic longitudinal, lateral-directional stability characteristics for a given airplane. Currently available analysis methods were evaluated to ascertain those most appropriate for the design functions which the GASP computerized design program performs. Methods for providing proper constraint and/or analysis functions for GASP were developed as well as the appropriate subroutines.

Aerodynamic design of turbomachinery blading in three-dimensional flow - An application to radial inflow turbines

NASA Technical Reports Server (NTRS)

Yang, Y. L.; Tan, C. S.; Hawthorne, W. R.

1992-01-01

A computational method, based on a theory for turbomachinery blading design in three-dimensional inviscid flow, is applied to a parametric design study of a radial inflow turbine wheel. As the method requires the specification of swirl distribution, a technique for its smooth generation within the blade region is proposed. Excellent agreements have been obtained between the computed results from this design method and those from direct Euler computations, demonstrating the correspondence and consistency between the two. The computed results indicate the sensitivity of the pressure distribution to a lean in the stacking axis and a minor alteration in the hub/shroud profiles. Analysis based on Navier-Stokes solver shows no breakdown of flow within the designed blade passage and agreement with that from design calculation; thus the flow in the designed turbine rotor closely approximates that of an inviscid one. These calculations illustrate the use of a design method coupled to an analysis tool for establishing guidelines and criteria for designing turbomachinery blading.

A comparison of methods to estimate future sub-daily design rainfall

NASA Astrophysics Data System (ADS)

Li, J.; Johnson, F.; Evans, J.; Sharma, A.

2017-12-01

Warmer temperatures are expected to increase extreme short-duration rainfall due to the increased moisture-holding capacity of the atmosphere. While attention has been paid to the impacts of climate change on future design rainfalls at daily or longer time scales, the potential changes in short duration design rainfalls have been often overlooked due to the limited availability of sub-daily projections and observations. This study uses a high-resolution regional climate model (RCM) to predict the changes in sub-daily design rainfalls for the Greater Sydney region in Australia. Sixteen methods for predicting changes to sub-daily future extremes are assessed based on different options for bias correction, disaggregation and frequency analysis. A Monte Carlo cross-validation procedure is employed to evaluate the skill of each method in estimating the design rainfall for the current climate. It is found that bias correction significantly improves the accuracy of the design rainfall estimated for the current climate. For 1 h events, bias correcting the hourly annual maximum rainfall simulated by the RCM produces design rainfall closest to observations, whereas for multi-hour events, disaggregating the daily rainfall total is recommended. This suggests that the RCM fails to simulate the observed multi-duration rainfall persistence, which is a common issue for most climate models. Despite the significant differences in the estimated design rainfalls between different methods, all methods lead to an increase in design rainfalls across the majority of the study region.

Application of a Novel Collaboration Engineering Method for Learning Design: A Case Study

ERIC Educational Resources Information Center

Cheng, Xusen; Li, Yuanyuan; Sun, Jianshan; Huang, Jianqing

2016-01-01

Collaborative case studies and computer-supported collaborative learning (CSCL) play an important role in the modern education environment. A number of researchers have given significant attention to learning design in order to improve the satisfaction of collaborative learning. Although collaboration engineering (CE) is a mature method widely…

Development of a method of alignment between various SOLAR MAXIMUM MISSION experiments

NASA Technical Reports Server (NTRS)

1977-01-01

Results of an engineering study of the methods of alignment between various experiments for the solar maximum mission are described. The configuration studied consists of the instruments, mounts and instrument support platform located within the experiment module. Hardware design, fabrication methods and alignment techniques were studied with regard to optimizing the coalignment between the experiments and the fine sun sensor. The proposed hardware design was reviewed with regard to loads, stress, thermal distortion, alignment error budgets, fabrication techniques, alignment techniques and producibility. Methods of achieving comparable alignment accuracies on previous projects were also reviewed.

Effect of Direct Teaching Method on the Academic Achievement of High and Low Achievers in the Subject of English at the Secondary Level

ERIC Educational Resources Information Center

Hussain, Ishtiaq; Hamdani, Syed Nisar Hussain; Quraishi, Uzma; Zeeshan, Muhammad

2010-01-01

The major objective of the study was to determine the role of the direct teaching method in the academic achievement of students in English at the secondary level. To achieve the said objective, the Solomon Four-Design pre-test/post-test equivalent group design was considered to be the most useful design for this study. The pre-test was used to…

Discrete choice experiments of pharmacy services: a systematic review.

PubMed

Vass, Caroline; Gray, Ewan; Payne, Katherine

2016-06-01

Background Two previous systematic reviews have summarised the application of discrete choice experiments to value preferences for pharmacy services. These reviews identified a total of twelve studies and described how discrete choice experiments have been used to value pharmacy services but did not describe or discuss the application of methods used in the design or analysis. Aims (1) To update the most recent systematic review and critically appraise current discrete choice experiments of pharmacy services in line with published reporting criteria and; (2) To provide an overview of key methodological developments in the design and analysis of discrete choice experiments. Methods The review used a comprehensive strategy to identify eligible studies (published between 1990 and 2015) by searching electronic databases for key terms related to discrete choice and best-worst scaling (BWS) experiments. All healthcare choice experiments were then hand-searched for key terms relating to pharmacy. Data were extracted using a published checklist. Results A total of 17 discrete choice experiments eliciting preferences for pharmacy services were identified for inclusion in the review. No BWS studies were identified. The studies elicited preferences from a variety of populations (pharmacists, patients, students) for a range of pharmacy services. Most studies were from a United Kingdom setting, although examples from Europe, Australia and North America were also identified. Discrete choice experiments for pharmacy services tended to include more attributes than non-pharmacy choice experiments. Few studies reported the use of qualitative research methods in the design and interpretation of the experiments (n = 9) or use of new methods of analysis to identify and quantify preference and scale heterogeneity (n = 4). No studies reported the use of Bayesian methods in their experimental design. Conclusion Incorporating more sophisticated methods in the design of pharmacy-related discrete choice experiments could help researchers produce more efficient experiments which are better suited to valuing complex pharmacy services. Pharmacy-related discrete choice experiments could also benefit from more sophisticated analytical techniques such as investigations into scale and preference heterogeneity. Employing these sophisticated methods for both design and analysis could extend the usefulness of discrete choice experiments to inform health and pharmacy policy.

Neural network and multiple linear regression to predict school children dimensions for ergonomic school furniture design.

PubMed

Agha, Salah R; Alnahhal, Mohammed J

2012-11-01

The current study investigates the possibility of obtaining the anthropometric dimensions, critical to school furniture design, without measuring all of them. The study first selects some anthropometric dimensions that are easy to measure. Two methods are then used to check if these easy-to-measure dimensions can predict the dimensions critical to the furniture design. These methods are multiple linear regression and neural networks. Each dimension that is deemed necessary to ergonomically design school furniture is expressed as a function of some other measured anthropometric dimensions. Results show that out of the five dimensions needed for chair design, four can be related to other dimensions that can be measured while children are standing. Therefore, the method suggested here would definitely save time and effort and avoid the difficulty of dealing with students while measuring these dimensions. In general, it was found that neural networks perform better than multiple linear regression in the current study. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

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

ERIC Educational Resources Information Center

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

2017-01-01

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

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

PubMed

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.

Denoising Sparse Images from GRAPPA using the Nullspace Method (DESIGN)

PubMed Central

Weller, Daniel S.; Polimeni, Jonathan R.; Grady, Leo; Wald, Lawrence L.; Adalsteinsson, Elfar; Goyal, Vivek K

2011-01-01

To accelerate magnetic resonance imaging using uniformly undersampled (nonrandom) parallel imaging beyond what is achievable with GRAPPA alone, the Denoising of Sparse Images from GRAPPA using the Nullspace method (DESIGN) is developed. The trade-off between denoising and smoothing the GRAPPA solution is studied for different levels of acceleration. Several brain images reconstructed from uniformly undersampled k-space data using DESIGN are compared against reconstructions using existing methods in terms of difference images (a qualitative measure), PSNR, and noise amplification (g-factors) as measured using the pseudo-multiple replica method. Effects of smoothing, including contrast loss, are studied in synthetic phantom data. In the experiments presented, the contrast loss and spatial resolution are competitive with existing methods. Results for several brain images demonstrate significant improvements over GRAPPA at high acceleration factors in denoising performance with limited blurring or smoothing artifacts. In addition, the measured g-factors suggest that DESIGN mitigates noise amplification better than both GRAPPA and L1 SPIR-iT (the latter limited here by uniform undersampling). PMID:22213069

Recent theoretical developments and experimental studies pertinent to vortex flow aerodynamics - With a view towards design

NASA Technical Reports Server (NTRS)

Lamar, J. E.; Luckring, J. M.

1978-01-01

A review is presented of recent progress in a research program directed towards the development of an improved vortex-flow technology base. It is pointed out that separation induced vortex-flows from the leading and side edges play an important role in the high angle-of-attack aerodynamic characteristics of a wide range of modern aircraft. In the analysis and design of high-speed aircraft, a detailed knowledge of this type of separation is required, particularly with regard to critical wind loads and the stability and performance at various off-design conditions. A description of analytical methods is presented. The theoretical methods employed are divided into two classes which are dependent upon the underlying aerodynamic assumptions. One conical flow method is considered along with three different nonconical flow methods. Comparisons are conducted between the described methods and available aerodynamic data. Attention is also given to a vortex flow drag study and a vortex flow wing design using suction analogy.

User-Centered Iterative Design of a Collaborative Virtual Environment

DTIC Science & Technology

2001-03-01

cognitive task analysis methods to study land navigators. This study was intended to validate the use of user-centered design methodologies for the design of...have explored the cognitive aspects of collaborative human way finding and design for collaborative virtual environments. Further investigation of design paradigms should include cognitive task analysis and behavioral task analysis.

Design of transonic airfoil sections using a similarity theory

NASA Technical Reports Server (NTRS)

Nixon, D.

1978-01-01

A study of the available methods for transonic airfoil and wing design indicates that the most powerful technique is the numerical optimization procedure. However, the computer time for this method is relatively large because of the amount of computation required in the searches during optimization. The optimization method requires that base and calibration solutions be computed to determine a minimum drag direction. The design space is then computationally searched in this direction; it is these searches that dominate the computation time. A recent similarity theory allows certain transonic flows to be calculated rapidly from the base and calibration solutions. In this paper the application of the similarity theory to design problems is examined with the object of at least partially eliminating the costly searches of the design optimization method. An example of an airfoil design is presented.

Comparison of safety effect estimates obtained from empirical Bayes before-after study, propensity scores-potential outcomes framework, and regression model with cross-sectional data.

PubMed

Wood, Jonathan S; Donnell, Eric T; Porter, Richard J

2015-02-01

A variety of different study designs and analysis methods have been used to evaluate the performance of traffic safety countermeasures. The most common study designs and methods include observational before-after studies using the empirical Bayes method and cross-sectional studies using regression models. The propensity scores-potential outcomes framework has recently been proposed as an alternative traffic safety countermeasure evaluation method to address the challenges associated with selection biases that can be part of cross-sectional studies. Crash modification factors derived from the application of all three methods have not yet been compared. This paper compares the results of retrospective, observational evaluations of a traffic safety countermeasure using both before-after and cross-sectional study designs. The paper describes the strengths and limitations of each method, focusing primarily on how each addresses site selection bias, which is a common issue in observational safety studies. The Safety Edge paving technique, which seeks to mitigate crashes related to roadway departure events, is the countermeasure used in the present study to compare the alternative evaluation methods. The results indicated that all three methods yielded results that were consistent with each other and with previous research. The empirical Bayes results had the smallest standard errors. It is concluded that the propensity scores with potential outcomes framework is a viable alternative analysis method to the empirical Bayes before-after study. It should be considered whenever a before-after study is not possible or practical. Copyright © 2014 Elsevier Ltd. All rights reserved.

Designing Measurement Studies under Budget Constraints: Controlling Error of Measurement and Power.

ERIC Educational Resources Information Center

Marcoulides, George A.

1995-01-01

A methodology is presented for minimizing the mean error variance-covariance component in studies with resource constraints. The method is illustrated using a one-facet multivariate design. Extensions to other designs are discussed. (SLD)

Outcome-Dependent Sampling Design and Inference for Cox’s Proportional Hazards Model

PubMed Central

Yu, Jichang; Liu, Yanyan; Cai, Jianwen; Sandler, Dale P.; Zhou, Haibo

2016-01-01

We propose a cost-effective outcome-dependent sampling design for the failure time data and develop an efficient inference procedure for data collected with this design. To account for the biased sampling scheme, we derive estimators from a weighted partial likelihood estimating equation. The proposed estimators for regression parameters are shown to be consistent and asymptotically normally distributed. A criteria that can be used to optimally implement the ODS design in practice is proposed and studied. The small sample performance of the proposed method is evaluated by simulation studies. The proposed design and inference procedure is shown to be statistically more powerful than existing alternative designs with the same sample sizes. We illustrate the proposed method with an existing real data from the Cancer Incidence and Mortality of Uranium Miners Study. PMID:28090134

A standardized mean difference effect size for multiple baseline designs across individuals.

PubMed

Hedges, Larry V; Pustejovsky, James E; Shadish, William R

2013-12-01

Single-case designs are a class of research methods for evaluating treatment effects by measuring outcomes repeatedly over time while systematically introducing different condition (e.g., treatment and control) to the same individual. The designs are used across fields such as behavior analysis, clinical psychology, special education, and medicine. Emerging standards for single-case designs have focused attention on methods for summarizing and meta-analyzing findings and on the need for effect sizes indices that are comparable to those used in between-subjects designs. In the previous work, we discussed how to define and estimate an effect size that is directly comparable to the standardized mean difference often used in between-subjects research based on the data from a particular type of single-case design, the treatment reversal or (AB)(k) design. This paper extends the effect size measure to another type of single-case study, the multiple baseline design. We propose estimation methods for the effect size and its variance, study the estimators using simulation, and demonstrate the approach in two applications. Copyright © 2013 John Wiley & Sons, Ltd.

A Discourse on Human Systems Integration

DTIC Science & Technology

2010-09-01

criterion for one of the study tasks. 2. Research Design This was a mixed methods study. The first-phase quantitative portion of the study...used a quasi-experimental, posttest-only with nonequivalent groups design . The independent variables were defined as follows: • The categorical... Research Design ...............................................................................287 3. Instruments

The Development, Description and Appraisal of an Emergent Multimethod Research Design to Study Workforce Changes in Integrated Care Interventions

PubMed Central

Luijkx, Katrien; Calciolari, Stefano; González-Ortiz, Laura G.

2017-01-01

Introduction: In this paper, we provide a detailed and explicit description of the processes and decisions underlying and shaping the emergent multimethod research design of our study on workforce changes in integrated chronic care. Theory and methods: The study was originally planned as mixed method research consisting of a preliminary literature review and quantitative check of these findings via a Delphi panel. However, when the findings of the literature review were not appropriate for quantitative confirmation, we chose to continue our qualitative exploration of the topic via qualitative questionnaires and secondary analysis of two best practice case reports. Results: The resulting research design is schematically described as an emergent and interactive multimethod design with multiphase combination timing. In doing so, we provide other researchers with a set of theory- and experience-based options to develop their own multimethod research and provide an example for more detailed and structured reporting of emergent designs. Conclusion and discussion: We argue that the terminology developed for the description of mixed methods designs should also be used for multimethod designs such as the one presented here. PMID:29042843

Near Zero Energy House (NZEH) Design Optimization to Improve Life Cycle Cost Performance Using Genetic Algorithm

NASA Astrophysics Data System (ADS)

Latief, Y.; Berawi, M. A.; Koesalamwardi, A. B.; Supriadi, L. S. R.

2018-03-01

Near Zero Energy House (NZEH) is a housing building that provides energy efficiency by using renewable energy technologies and passive house design. Currently, the costs for NZEH are quite expensive due to the high costs of the equipment and materials for solar panel, insulation, fenestration and other renewable energy technology. Therefore, a study to obtain the optimum design of a NZEH is necessary. The aim of the optimum design is achieving an economical life cycle cost performance of the NZEH. One of the optimization methods that could be utilized is Genetic Algorithm. It provides the method to obtain the optimum design based on the combinations of NZEH variable designs. This paper discusses the study to identify the optimum design of a NZEH that provides an optimum life cycle cost performance using Genetic Algorithm. In this study, an experiment through extensive design simulations of a one-level house model was conducted. As a result, the study provide the optimum design from combinations of NZEH variable designs, which are building orientation, window to wall ratio, and glazing types that would maximize the energy generated by photovoltaic panel. Hence, the design would support an optimum life cycle cost performance of the house.

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

PubMed

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.

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

ERIC Educational Resources Information Center

South, Jane; Cattan, Mima

2014-01-01

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

The Effects of Web-Based Interactive Virtual Tours on the Development of Prospective Mathematics Teachers' Spatial Skills

ERIC Educational Resources Information Center

Kurtulus, Aytac

2013-01-01

The aim of this study was to investigate the effects of web-based interactive virtual tours on the development of prospective mathematics teachers' spatial skills. The study was designed based on experimental method. The "one-group pre-test post-test design" of this method was taken as the research model. The study was conducted with 3rd year…

A first principles based methodology for design of axial compressor configurations

NASA Astrophysics Data System (ADS)

Iyengar, Vishwas

Axial compressors are widely used in many aerodynamic applications. The design of an axial compressor configuration presents many challenges. Until recently, compressor design was done using 2-D viscous flow analyses that solve the flow field around cascades or in meridional planes or 3-D inviscid analyses. With the advent of modern computational methods it is now possible to analyze the 3-D viscous flow and accurately predict the performance of 3-D multistage compressors. It is necessary to retool the design methodologies to take advantage of the improved accuracy and physical fidelity of these advanced methods. In this study, a first-principles based multi-objective technique for designing single stage compressors is described. The study accounts for stage aerodynamic characteristics, rotor-stator interactions and blade elastic deformations. A parametric representation of compressor blades that include leading and trailing edge camber line angles, thickness and camber distributions was used in this study. A design of experiment approach is used to reduce the large combinations of design variables into a smaller subset. A response surface method is used to approximately map the output variables as a function of design variables. An optimized configuration is determined as the extremum of all extrema. This method has been applied to a rotor-stator stage similar to NASA Stage 35. The study has two parts: a preliminary study where a limited number of design variables were used to give an understanding of the important design variables for subsequent use, and a comprehensive application of the methodology where a larger, more complete set of design variables are used. The extended methodology also attempts to minimize the acoustic fluctuations at the rotor-stator interface by considering a rotor-wake influence coefficient (RWIC). Results presented include performance map calculations at design and off-design speed along with a detailed visualization of the flow field at design and off-design conditions. The present methodology provides a way to systematically screening through the plethora of design variables. By selecting the most influential design parameters and by optimizing the blade leading edge and trailing edge mean camber line angles, phenomenon's such as tip blockages, blade-to-blade shock structures and other loss mechanisms can be weakened or alleviated. It is found that these changes to the configuration can have a beneficial effect on total pressure ratio and stage adiabatic efficiency, thereby improving the performance of the axial compression system. Aeroacoustic benefits were found by minimizing the noise generating mechanisms associated with rotor wake-stator interactions. The new method presented is reliable, low time cost, and easily applicable to industry daily design optimization of turbomachinery blades.

Connecting Generations: Developing Co-Design Methods for Older Adults and Children

ERIC Educational Resources Information Center

Xie, Bo; Druin, Allison; Fails, Jerry; Massey, Sheri; Golub, Evan; Franckel, Sonia; Schneider, Kiki

2012-01-01

As new technologies emerge that can bring older adults together with children, little has been discussed by researchers concerning the design methods used to create these new technologies. Giving both children and older adults a voice in a shared design process comes with many challenges. This paper details an exploratory study focusing on…

Paragogy and Flipped Assessment: Experience of Designing and Running a MOOC on Research Methods

ERIC Educational Resources Information Center

Lee, Yenn; Rofe, J. Simon

2016-01-01

This study draws on the authors' first-hand experience of designing, developing and delivering (3Ds) a massive open online course (MOOC) entitled "Understanding Research Methods" since 2014, largely but not exclusively for learners in the humanities and social sciences. The greatest challenge facing us was to design an assessment…

Development of steel design details and selection criteria for cost effective and innovative steel bridges in Colorado : CDOT study no. 85-00 final report.

DOT National Transportation Integrated Search

2011-07-01

This research focuses on finding a method for creating cost effective and innovative steel bridges in Colorado. The design method that was discovered to create this cost efficiency was designing the beams as simply supported for non-composite dead lo...

Comparative performance of conventional OPC concrete and HPC designed by densified mixture design algorithm

NASA Astrophysics Data System (ADS)

Huynh, Trong-Phuoc; Hwang, Chao-Lung; Yang, Shu-Ti

2017-12-01

This experimental study evaluated the performance of normal ordinary Portland cement (OPC) concrete and high-performance concrete (HPC) that were designed by the conventional method (ACI) and densified mixture design algorithm (DMDA) method, respectively. Engineering properties and durability performance of both the OPC and HPC samples were studied using the tests of workability, compressive strength, water absorption, ultrasonic pulse velocity, and electrical surface resistivity. Test results show that the HPC performed good fresh property and further showed better performance in terms of strength and durability as compared to the OPC.

Deconstructing the complexity of substance use among young men who have sex with men (YMSM) by optimizing the role of qualitative strategies in a mixed methods study.

PubMed

Kubicek, Katrina; Weiss, George; Iverson, Ellen F; Kipke, Michele D

2010-04-01

Qualitative data can be a powerful tool in developing interventions for substance use and other HIV-risk behaviors. Mixed methods design offers researchers the ability to obtain data that provides both breadth and depth to their research questions. However, the integration of qualitative data in mixed methods research has been limited. This paper describes the qualitative study design of the Healthy Young Men's Study, a longitudinal mixed method study with an ethnically diverse cohort of young men who have sex with men (YMSM) (N = 526) in Los Angeles. Integral to this discussion is how a mixed methods study can address common challenges such as sampling, representation and integration of both datasets.

A study of commuter airplane design optimization

NASA Technical Reports Server (NTRS)

Roskam, J.; Wyatt, R. D.; Griswold, D. A.; Hammer, J. L.

1977-01-01

Problems of commuter airplane configuration design were studied to affect a minimization of direct operating costs. Factors considered were the minimization of fuselage drag, methods of wing design, and the estimated drag of an airplane submerged in a propellor slipstream; all design criteria were studied under a set of fixed performance, mission, and stability constraints. Configuration design data were assembled for application by a computerized design methodology program similar to the NASA-Ames General Aviation Synthesis Program.

The theoretical study of passive and active optical devices via planewave based transfer (scattering) matrix method and other approaches

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

Zhuo, Ye

2011-01-01

In this thesis, we theoretically study the electromagnetic wave propagation in several passive and active optical components and devices including 2-D photonic crystals, straight and curved waveguides, organic light emitting diodes (OLEDs), and etc. Several optical designs are also presented like organic photovoltaic (OPV) cells and solar concentrators. The first part of the thesis focuses on theoretical investigation. First, the plane-wave-based transfer (scattering) matrix method (TMM) is briefly described with a short review of photonic crystals and other numerical methods to study them (Chapter 1 and 2). Next TMM, the numerical method itself is investigated in details and developed inmore » advance to deal with more complex optical systems. In chapter 3, TMM is extended in curvilinear coordinates to study curved nanoribbon waveguides. The problem of a curved structure is transformed into an equivalent one of a straight structure with spatially dependent tensors of dielectric constant and magnetic permeability. In chapter 4, a new set of localized basis orbitals are introduced to locally represent electromagnetic field in photonic crystals as alternative to planewave basis. The second part of the thesis focuses on the design of optical devices. First, two examples of TMM applications are given. The first example is the design of metal grating structures as replacements of ITO to enhance the optical absorption in OPV cells (chapter 6). The second one is the design of the same structure as above to enhance the light extraction of OLEDs (chapter 7). Next, two design examples by ray tracing method are given, including applying a microlens array to enhance the light extraction of OLEDs (chapter 5) and an all-angle wide-wavelength design of solar concentrator (chapter 8). In summary, this dissertation has extended TMM which makes it capable of treating complex optical systems. Several optical designs by TMM and ray tracing method are also given as a full complement of this work.« less

Applying Item Response Theory Methods to Design a Learning Progression-Based Science Assessment

ERIC Educational Resources Information Center

Chen, Jing

2012-01-01

Learning progressions are used to describe how students' understanding of a topic progresses over time and to classify the progress of students into steps or levels. This study applies Item Response Theory (IRT) based methods to investigate how to design learning progression-based science assessments. The research questions of this study are: (1)…

Perception of Teachers and Administrators on the Teaching Methods That Influence the Acquisition of Generic Skills

ERIC Educational Resources Information Center

Audu, R.; Bin Kamin, Yusri; Bin Musta'amal, Aede Hatib; Bin Saud, Muhammad Sukri; Hamid, Mohd. Zolkifli Abd.

2014-01-01

This study is designed to identify the most significant teaching methods that influence the acquisition of generic skills of mechanical engineering trades students at technical college level. Descriptive survey research design was utilized in carrying out the study. One hundred and ninety (190) respondents comprised of mechanical engineering…

Design and analysis of multiple diseases genome-wide association studies without controls.

PubMed

Chen, Zhongxue; Huang, Hanwen; Ng, Hon Keung Tony

2012-11-15

In genome-wide association studies (GWAS), multiple diseases with shared controls is one of the case-control study designs. If data obtained from these studies are appropriately analyzed, this design can have several advantages such as improving statistical power in detecting associations and reducing the time and cost in the data collection process. In this paper, we propose a study design for GWAS which involves multiple diseases but without controls. We also propose corresponding statistical data analysis strategy for GWAS with multiple diseases but no controls. Through a simulation study, we show that the statistical association test with the proposed study design is more powerful than the test with single disease sharing common controls, and it has comparable power to the overall test based on the whole dataset including the controls. We also apply the proposed method to a real GWAS dataset to illustrate the methodologies and the advantages of the proposed design. Some possible limitations of this study design and testing method and their solutions are also discussed. Our findings indicate that the proposed study design and statistical analysis strategy could be more efficient than the usual case-control GWAS as well as those with shared controls. Copyright © 2012 Elsevier B.V. All rights reserved.

Comprehensive Design Reliability Activities for Aerospace Propulsion Systems

NASA Technical Reports Server (NTRS)

Christenson, R. L.; Whitley, M. R.; Knight, K. C.

2000-01-01

This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.

Prospective Mathematics Teachers' Opinions about Mathematical Modeling Method and Applicability of This Method

ERIC Educational Resources Information Center

Akgün, Levent

2015-01-01

The aim of this study is to identify prospective secondary mathematics teachers' opinions about the mathematical modeling method and the applicability of this method in high schools. The case study design, which is among the qualitative research methods, was used in the study. The study was conducted with six prospective secondary mathematics…

Structural optimization for joined-wing synthesis

NASA Technical Reports Server (NTRS)

Gallman, John W.; Kroo, Ilan M.

1992-01-01

The differences between fully stressed and minimum-weight joined-wing structures are identified, and these differences are quantified in terms of weight, stress, and direct operating cost. A numerical optimization method and a fully stressed design method are used to design joined-wing structures. Both methods determine the sizes of 204 structural members, satisfying 1020 stress constraints and five buckling constraints. Monotonic splines are shown to be a very effective way of linking spanwise distributions of material to a few design variables. Both linear and nonlinear analyses are employed to formulate the buckling constraints. With a constraint on buckling, the fully stressed design is shown to be very similar to the minimum-weight structure. It is suggested that a fully stressed design method based on nonlinear analysis is adequate for an aircraft optimization study.

Riser Feeding Evaluation Method for Metal Castings Using Numerical Analysis

NASA Astrophysics Data System (ADS)

Ahmad, Nadiah

One of the design aspects that continues to create a challenge for casting designers is the optimum design of casting feeders (risers). As liquid metal solidifies, the metal shrinks and forms cavities inside the casting. In order to avoid shrinkage cavities, risers are added to the casting shape to supply additional molten metal when shrinkage occurs during solidification. The shrinkage cavities in the casting are compensated by controlling the cooling rate to promote directional solidification. This control can be achieved by designing the casting such that the cooling begins at the sections that are farthest away from the risers and ends at the risers. Therefore, the risers will solidify last and feed the casting with the molten metal. As a result, the shrinkage cavities formed during solidification are in the risers which are later removed from the casting. Since casting designers have to usually go through iterative processes of validating the casting designs which are very costly due to expensive simulation processes or manual trials and errors on actual casting processes, this study investigates more efficient methods that will help casting designers utilize their casting experiences systematically to develop good initial casting designs. The objective is to reduce the casting design method iterations; therefore, reducing the cost involved in that design processes. The aim of this research aims at finding a method that can help casting designers design effective risers used in sand casting process of aluminum-silicon alloys by utilizing the analysis of solidification simulation. The analysis focuses on studying the significance of pressure distribution of the liquid metal at the early stage of casting solidification, when heat transfer and convective fluid flow are taken into account in the solidification simulation. The mathematical model of casting solidification was solved using the finite volume method (FVM). This study focuses to improve our understanding of the feeding behavior in aluminum-silicon alloys and the effective feeding by considering the pressure gradient distribution of the molten metal at casting dendrite coherency point. For this study, we will identify the relationship between feeding efficiency, shrinkage behavior and how the change in riser size affects the pressure gradient in the casting. This understanding will be used to help in the design of effective risers.

An improved design method based on polyphase components for digital FIR filters

NASA Astrophysics Data System (ADS)

Kumar, A.; Kuldeep, B.; Singh, G. K.; Lee, Heung No

2017-11-01

This paper presents an efficient design of digital finite impulse response (FIR) filter, based on polyphase components and swarm optimisation techniques (SOTs). For this purpose, the design problem is formulated as mean square error between the actual response and ideal response in frequency domain using polyphase components of a prototype filter. To achieve more precise frequency response at some specified frequency, fractional derivative constraints (FDCs) have been applied, and optimal FDCs are computed using SOTs such as cuckoo search and modified cuckoo search algorithms. A comparative study of well-proved swarm optimisation, called particle swarm optimisation and artificial bee colony algorithm is made. The excellence of proposed method is evaluated using several important attributes of a filter. Comparative study evidences the excellence of proposed method for effective design of FIR filter.

An approximate solution to improve computational efficiency of impedance-type payload load prediction

NASA Technical Reports Server (NTRS)

White, C. W.

1981-01-01

The computational efficiency of the impedance type loads prediction method was studied. Three goals were addressed: devise a method to make the impedance method operate more efficiently in the computer; assess the accuracy and convenience of the method for determining the effect of design changes; and investigate the use of the method to identify design changes for reduction of payload loads. The method is suitable for calculation of dynamic response in either the frequency or time domain. It is concluded that: the choice of an orthogonal coordinate system will allow the impedance method to operate more efficiently in the computer; the approximate mode impedance technique is adequate for determining the effect of design changes, and is applicable for both statically determinate and statically indeterminate payload attachments; and beneficial design changes to reduce payload loads can be identified by the combined application of impedance techniques and energy distribution review techniques.

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

PubMed

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

2015-06-07

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

A comparison of trends in research into home care services in Japan and Korea

PubMed Central

2013-01-01

Background The purpose of this study is to compare of the research trends for home care services in Japan and the Republic of Korea (Korea). In particular, it was compared as the research design, the method of data collection, and key words by literature review. Methods Original articles on home care services were selected from Japanese and Korean journals published from the year of 2004 to 2008. The articles were classified, and compared in terms of the number of articles per year. Results The research design was quite different. Quantitative research design was dominantly conducted in Korea, qualitative research design was used same level of design in Japan. In particular, outcome study was shown in Korean. Conclusions It is suggested that future collaboration be undertaken to improve the variety of research design and method especially in both countries under the aged society. In addition, it provides information concerning research concepts, which can be applied to optimize future home care services. PMID:23870373

Developing the DESCARTE Model: The Design of Case Study Research in Health Care.

PubMed

Carolan, Clare M; Forbat, Liz; Smith, Annetta

2016-04-01

Case study is a long-established research tradition which predates the recent surge in mixed-methods research. Although a myriad of nuanced definitions of case study exist, seminal case study authors agree that the use of multiple data sources typify this research approach. The expansive case study literature demonstrates a lack of clarity and guidance in designing and reporting this approach to research. Informed by two reviews of the current health care literature, we posit that methodological description in case studies principally focuses on description of case study typology, which impedes the construction of methodologically clear and rigorous case studies. We draw from the case study and mixed-methods literature to develop the DESCARTE model as an innovative approach to the design, conduct, and reporting of case studies in health care. We examine how case study fits within the overall enterprise of qualitatively driven mixed-methods research, and the potential strengths of the model are considered. © The Author(s) 2015.

Mixed Methods in CAM Research: A Systematic Review of Studies Published in 2012

PubMed Central

Bishop, Felicity L.; Holmes, Michelle M.

2013-01-01

Background. Mixed methods research uses qualitative and quantitative methods together in a single study or a series of related studies. Objectives. To review the prevalence and quality of mixed methods studies in complementary medicine. Methods. All studies published in the top 10 integrative and complementary medicine journals in 2012 were screened. The quality of mixed methods studies was appraised using a published tool designed for mixed methods studies. Results. 4% of papers (95 out of 2349) reported mixed methods studies, 80 of which met criteria for applying the quality appraisal tool. The most popular formal mixed methods design was triangulation (used by 74% of studies), followed by embedded (14%), sequential explanatory (8%), and finally sequential exploratory (5%). Quantitative components were generally of higher quality than qualitative components; when quantitative components involved RCTs they were of particularly high quality. Common methodological limitations were identified. Most strikingly, none of the 80 mixed methods studies addressed the philosophical tensions inherent in mixing qualitative and quantitative methods. Conclusions and Implications. The quality of mixed methods research in CAM can be enhanced by addressing philosophical tensions and improving reporting of (a) analytic methods and reflexivity (in qualitative components) and (b) sampling and recruitment-related procedures (in all components). PMID:24454489

Gaming in the Classroom: An Innovative Way to Teach Factorial Designs

ERIC Educational Resources Information Center

Stansbury, Jessica A.; Munro, Geoffrey D.

2013-01-01

This study tested the effectiveness of video game use for instruction of factorial designs in a research methods course. Students designed and conducted a mini study, playing "Dance, Dance, Revolution", using video game scores as the dependent variable. A mixed-design analysis of variance revealed a significantly greater increase from pretest to…

Generating Alternative Engineering Designs by Integrating Desktop VR with Genetic Algorithms

ERIC Educational Resources Information Center

Chandramouli, Magesh; Bertoline, Gary; Connolly, Patrick

2009-01-01

This study proposes an innovative solution to the problem of multiobjective engineering design optimization by integrating desktop VR with genetic computing. Although, this study considers the case of construction design as an example to illustrate the framework, this method can very much be extended to other engineering design problems as well.…

Systems modelling approaches to the design of safe healthcare delivery: ease of use and usefulness perceived by healthcare workers.

PubMed

Jun, Gyuchan Thomas; Ward, James; Clarkson, P John

2010-07-01

The UK health service, which had been diagnosed to be seriously out of step with good design practice, has been recommended to obtain knowledge of design and risk management practice from other safety-critical industries. While these other industries have benefited from a broad range of systems modelling approaches, healthcare remains a long way behind. In order to investigate the healthcare-specific applicability of systems modelling approaches, this study identified 10 distinct methods through meta-model analysis. Healthcare workers' perception on 'ease of use' and 'usefulness' was then evaluated. The characterisation of the systems modelling methods showed that each method had particular capabilities to describe specific aspects of a complex system. However, the healthcare workers found that some of the methods, although potentially very useful, would be difficult to understand, particularly without prior experience. This study provides valuable insights into a better use of the systems modelling methods in healthcare. STATEMENT OF RELEVANCE: The findings in this study provide insights into how to make a better use of various systems modelling approaches to the design and risk management of healthcare delivery systems, which have been a growing research interest among ergonomists and human factor professionals.

Urban Environment Development based on Universal Design Principles

NASA Astrophysics Data System (ADS)

Harsritanto, Bangun Ir

2018-02-01

Universal Design is a design which facilitated full range of human diversity. By applying Universal design principles, urban environment can be more functional and more user-friendly for everyone. This study examined five urban streets of South Korea as a country experienced on developing various urban street designs based on universal design. This study aimed to examine and compare the South Korea cases using seven principles of universal design. The research methods of this study are literature study, case study, and site observation. The results of this study are: South Korea cases are good practices, urgency of implementing the direction into local regulations; and change of urban development paradigm.

A factorial design experiment as a pilot study for noninvasive genetic sampling.

PubMed

Renan, Sharon; Speyer, Edith; Shahar, Naama; Gueta, Tomer; Templeton, Alan R; Bar-David, Shirli

2012-11-01

Noninvasive genetic sampling has increasingly been used in ecological and conservation studies during the last decade. A major part of the noninvasive genetic literature is dedicated to the search for optimal protocols, by comparing different methods of collection, preservation and extraction of DNA from noninvasive materials. However, the lack of quantitative comparisons among these studies and the possibility that different methods are optimal for different systems make it difficult to decide which protocol to use. Moreover, most studies that have compared different methods focused on a single factor - collection, preservation or extraction - while there could be interactions between these factors. We designed a factorial experiment, as a pilot study, aimed at exploring the effect of several collection, preservation and extraction methods, and the interactions between them, on the quality and amplification success of DNA obtained from Asiatic wild ass (Equus hemionus) faeces in Israel. The amplification success rates of one mitochondrial DNA and four microsatellite markers differed substantially as a function of collection, preservation and extraction methods and their interactions. The most efficient combination for our system integrated the use of swabs as a collection method with preservation at -20 °C and with the Qiagen DNA Stool Kit with modifications as the DNA extraction method. The significant interaction found between the collection, preservation methods and the extraction methods reinforces the importance of conducting a factorial design experiment, rather than examining each factor separately, as a pilot study before initiating a full-scale noninvasive research project. © 2012 Blackwell Publishing Ltd.

Sequential ensemble-based optimal design for parameter estimation: SEQUENTIAL ENSEMBLE-BASED OPTIMAL DESIGN

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

Man, Jun; Zhang, Jiangjiang; Li, Weixuan

2016-10-01

The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees ofmore » freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.« less

An Empirical Comparison of Five Linear Equating Methods for the NEAT Design

ERIC Educational Resources Information Center

Suh, Youngsuk; Mroch, Andrew A.; Kane, Michael T.; Ripkey, Douglas R.

2009-01-01

In this study, a data base containing the responses of 40,000 candidates to 90 multiple-choice questions was used to mimic data sets for 50-item tests under the "nonequivalent groups with anchor test" (NEAT) design. Using these smaller data sets, we evaluated the performance of five linear equating methods for the NEAT design with five levels of…

Performance-Based Seismic Design of Steel Frames Utilizing Colliding Bodies Algorithm

PubMed Central

Veladi, H.

2014-01-01

A pushover analysis method based on semirigid connection concept is developed and the colliding bodies optimization algorithm is employed to find optimum seismic design of frame structures. Two numerical examples from the literature are studied. The results of the new algorithm are compared to the conventional design methods to show the power or weakness of the algorithm. PMID:25202717

Performance-based seismic design of steel frames utilizing colliding bodies algorithm.

PubMed

Veladi, H

2014-01-01

A pushover analysis method based on semirigid connection concept is developed and the colliding bodies optimization algorithm is employed to find optimum seismic design of frame structures. Two numerical examples from the literature are studied. The results of the new algorithm are compared to the conventional design methods to show the power or weakness of the algorithm.

Rotational Critique System as a Method of Culture Change in an Architecture Design Studio: Urban Design Studio as Case Study

ERIC Educational Resources Information Center

Fasli, Mukaddes; Hassanpour, Badiossadat

2017-01-01

In this century, all educational efforts strive to achieve quality assurance standards. Therefore, it will be naive to deny the existence of problems in architectural education. The current design studio critique method has been developed upon generations of students and educators. Architectural education is changing towards educating critical…

NASA gear research and its probable effect on rotorcraft transmission design

NASA Technical Reports Server (NTRS)

Zaretsky, E. V.; Townsend, D. P.; Coy, J. J.

1979-01-01

The results of the NASA gear research is reviewed as well as those programs which are presently being undertaken. Research programs studying pitting fatigue, gear steels and processing, life prediction methods, gear design and dynamics, elastohydrodynamic lubrication, lubrication methods and gear noise are presented. The impact of advanced gear research technology on rotorcraft transmission design is discussed.

Effectiveness of Facebook Based Learning to Enhance Creativity among Islamic Studies Students by Employing Isman Instructional Design Model

ERIC Educational Resources Information Center

Alias, Norlidah; Siraj, Saedah; Daud, Mohd Khairul Azman Md; Hussin, Zaharah

2013-01-01

The study examines the effectiveness of Facebook based learning to enhance creativity among Islamic Studies students in the secondary educational setting in Malaysia. It describes the design process by employing the Isman Instructional Design Model. A quantitative study was carried out using experimental method and background survey. The…

CEREC Chairside System to Register and Design the Occlusion in Restorative Dentistry: A Systematic Literature Review.

PubMed

Bohner, Lauren Oliveira Lima; Neto, Pedro Tortamano; Ahmed, Ahad Shahid; Mori, Matsuyoshi; Laganá, Dalva Cruz; Sesma, Newton

2016-07-01

The aim of this review was to update the literature with regard to the digital methods available by CEREC Chairside system to register and design the occlusion, to report their efficacy and technical innovations in the field of Restorative Dentistry. A search strategy was performed using the key-words: "virtual articulator," or "CAD-CAM and occlusal recording," or "CAD-CAM and occlusion register," or "CAD-CAM and occlusal contacts," or "CAD-CAM and prosthesis." Inclusion criteria comprised studies evaluating the use of digital methods available by CEREC System for occlusal registration and design during prosthodontics treatment. PubMed and Cochrane library and reference lists were searched up to January 2016. The search resulted in 280 articles after removing duplicates. Subsequently, 233 records were excluded and 49 studies were selected for reading in full. Eleven articles were considered eligible for the systematic review (4 in vitro and 7 clinical studies). Scientific evidence suggests that digital methods were accurate to register and design the occlusion of dental prostheses. Nevertheless, further clinical studies are required to establish a conclusion with regard to its accuracy in prosthodontics treatment. Digital technologies allow the design of occlusal surfaces of CAD-CAM fabricated prostheses using innovative approaches. This systematic review aimed to update the literature to help dentists determine the most appropriate digital method to register and design the occlusal surface of CAD-CAM crowns. (J Esthet Restor Dent 28:208-220, 2016). © 2016 Wiley Periodicals, Inc.

An Investigation of the Artifacts and Process of Constructing Computers Games about Environmental Science in a Fifth Grade Classroom

ERIC Educational Resources Information Center

Baytak, Ahmet; Land, Susan M.

2011-01-01

This study employed a case study design (Yin, "Case study research, design and methods," 2009) to investigate the processes used by 5th graders to design and develop computer games within the context of their environmental science unit, using the theoretical framework of "constructionism." Ten fifth graders designed computer games using "Scratch"…

Characterizing Design Learning through the Use of Language: A Mixed-Methods Study of Engineering Designers. Research Brief

ERIC Educational Resources Information Center

Atman, Cindy; Kilgore, Deborah; McKenna, Ann

2009-01-01

This analysis, that utilizes data from part of the Academic Pathways Study (APS) of the Center for the Advancement of Engineering Education (CAEE), found that as a result of taking a course in engineering design and/or studying engineering for four years, students acquire engineering design language that is common to a larger community of practice…

A Homogenization Approach for Design and Simulation of Blast Resistant Composites

NASA Astrophysics Data System (ADS)

Sheyka, Michael

Structural composites have been used in aerospace and structural engineering due to their high strength to weight ratio. Composite laminates have been successfully and extensively used in blast mitigation. This dissertation examines the use of the homogenization approach to design and simulate blast resistant composites. Three case studies are performed to examine the usefulness of different methods that may be used in designing and optimizing composite plates for blast resistance. The first case study utilizes a single degree of freedom system to simulate the blast and a reliability based approach. The first case study examines homogeneous plates and the optimal stacking sequence and plate thicknesses are determined. The second and third case studies use the homogenization method to calculate the properties of composite unit cell made of two different materials. The methods are integrated with dynamic simulation environments and advanced optimization algorithms. The second case study is 2-D and uses an implicit blast simulation, while the third case study is 3-D and simulates blast using the explicit blast method. Both case studies 2 and 3 rely on multi-objective genetic algorithms for the optimization process. Pareto optimal solutions are determined in case studies 2 and 3. Case study 3 is an integrative method for determining optimal stacking sequence, microstructure and plate thicknesses. The validity of the different methods such as homogenization, reliability, explicit blast modeling and multi-objective genetic algorithms are discussed. Possible extension of the methods to include strain rate effects and parallel computation is also examined.

Cost model relationships between textile manufacturing processes and design details for transport fuselage elements

NASA Technical Reports Server (NTRS)

Metschan, Stephen L.; Wilden, Kurtis S.; Sharpless, Garrett C.; Andelman, Rich M.

1993-01-01

Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design.

The Importance of Considering Differences in Study Design in Network Meta-analysis: An Application Using Anti-Tumor Necrosis Factor Drugs for Ulcerative Colitis.

PubMed

Cameron, Chris; Ewara, Emmanuel; Wilson, Florence R; Varu, Abhishek; Dyrda, Peter; Hutton, Brian; Ingham, Michael

2017-11-01

Adaptive trial designs present a methodological challenge when performing network meta-analysis (NMA), as data from such adaptive trial designs differ from conventional parallel design randomized controlled trials (RCTs). We aim to illustrate the importance of considering study design when conducting an NMA. Three NMAs comparing anti-tumor necrosis factor drugs for ulcerative colitis were compared and the analyses replicated using Bayesian NMA. The NMA comprised 3 RCTs comparing 4 treatments (adalimumab 40 mg, golimumab 50 mg, golimumab 100 mg, infliximab 5 mg/kg) and placebo. We investigated the impact of incorporating differences in the study design among the 3 RCTs and presented 3 alternative methods on how to convert outcome data derived from one form of adaptive design to more conventional parallel RCTs. Combining RCT results without considering variations in study design resulted in effect estimates that were biased against golimumab. In contrast, using the 3 alternative methods to convert outcome data from one form of adaptive design to a format more consistent with conventional parallel RCTs facilitated more transparent consideration of differences in study design. This approach is more likely to yield appropriate estimates of comparative efficacy when conducting an NMA, which includes treatments that use an alternative study design. RCTs based on adaptive study designs should not be combined with traditional parallel RCT designs in NMA. We have presented potential approaches to convert data from one form of adaptive design to more conventional parallel RCTs to facilitate transparent and less-biased comparisons.

Application of mathematical model methods for optimization tasks in construction materials technology

NASA Astrophysics Data System (ADS)

Fomina, E. V.; Kozhukhova, N. I.; Sverguzova, S. V.; Fomin, A. E.

2018-05-01

In this paper, the regression equations method for design of construction material was studied. Regression and polynomial equations representing the correlation between the studied parameters were proposed. The logic design and software interface of the regression equations method focused on parameter optimization to provide the energy saving effect at the stage of autoclave aerated concrete design considering the replacement of traditionally used quartz sand by coal mining by-product such as argillite. The mathematical model represented by a quadric polynomial for the design of experiment was obtained using calculated and experimental data. This allowed the estimation of relationship between the composition and final properties of the aerated concrete. The surface response graphically presented in a nomogram allowed the estimation of concrete properties in response to variation of composition within the x-space. The optimal range of argillite content was obtained leading to a reduction of raw materials demand, development of target plastic strength of aerated concrete as well as a reduction of curing time before autoclave treatment. Generally, this method allows the design of autoclave aerated concrete with required performance without additional resource and time costs.

Deconstructing the complexity of substance use among young men who have sex with men (YMSM) by optimizing the role of qualitative strategies in a mixed methods study

PubMed Central

Kubicek, Katrina; Weiss, George; Iverson, Ellen F.; Kipke, Michele D.

2010-01-01

Qualitative data can be a powerful tool in developing interventions for substance use and other HIV-risk behaviors. Mixed-methods design offers researchers the ability to obtain data that provides both breadth and depth to their research. However, the integration of qualitative data in mixed-methods research has been limited. This paper describes the qualitative design of the Healthy Young Men’s Study, a longitudinal mixed-method study with an ethnically diverse cohort of young men who have sex with men (YMSM) (N=526) in Los Angeles. Integral to this discussion is how a mixed-methods study can address common challenges such as sampling, representation and integration. PMID:20222783

Equating TIMSS Mathematics Subtests with Nonlinear Equating Methods Using NEAT Design: Circle-Arc Equating Approaches

ERIC Educational Resources Information Center

Ozdemir, Burhanettin

2017-01-01

The purpose of this study is to equate Trends in International Mathematics and Science Study (TIMSS) mathematics subtest scores obtained from TIMSS 2011 to scores obtained from TIMSS 2007 form with different nonlinear observed score equating methods under Non-Equivalent Anchor Test (NEAT) design where common items are used to link two or more test…

The Effect of Teaching Methods and Learning Style on Learning Program Design in Web-Based Education Systems

ERIC Educational Resources Information Center

Hung, Yen-Chu

2012-01-01

The instructional value of web-based education systems has been an important area of research in information systems education. This study investigates the effect of various teaching methods on program design learning for students with specific learning styles in web-based education systems. The study takes first-year Computer Science and…

Training and Work Organisation: An Action-Research Study in a Sales and Distribution Company

ERIC Educational Resources Information Center

Bernardes, Alda Cristina; Lopes, Albino Pedro

2005-01-01

This study seeks to define a method of designing work-linked training, based on day-to-day work practices and the collaboration between all those involved. From diagnosis to evaluation, no training is designed or given without considering the opinions and interests of the parties involved. The method used is based on action research (AR) and on…

Applying Program Theory-Driven Approach to Design and Evaluate a Teacher Professional Development Program

ERIC Educational Resources Information Center

Lin, Su-ching; Wu, Ming-sui

2016-01-01

This study was the first year of a two-year project which applied a program theory-driven approach to evaluating the impact of teachers' professional development interventions on students' learning by using a mix of methods, qualitative inquiry, and quasi-experimental design. The current study was to show the results of using the method of…

Material selection and assembly method of battery pack for compact electric vehicle

NASA Astrophysics Data System (ADS)

Lewchalermwong, N.; Masomtob, M.; Lailuck, V.; Charoenphonphanich, C.

2018-01-01

Battery packs become the key component in electric vehicles (EVs). The main costs of which are battery cells and assembling processes. The battery cell is indeed priced from battery manufacturers while the assembling cost is dependent on battery pack designs. Battery pack designers need overall cost as cheap as possible, but it still requires high performance and more safety. Material selection and assembly method as well as component design are very important to determine the cost-effectiveness of battery modules and battery packs. Therefore, this work presents Decision Matrix, which can aid in the decision-making process of component materials and assembly methods for a battery module design and a battery pack design. The aim of this study is to take the advantage of incorporating Architecture Analysis method into decision matrix methods by capturing best practices for conducting design architecture analysis in full account of key design components critical to ensure efficient and effective development of the designs. The methodology also considers the impacts of choice-alternatives along multiple dimensions. Various alternatives for materials and assembly techniques of battery pack are evaluated, and some sample costs are presented. Due to many components in the battery pack, only seven components which are positive busbar and Z busbar are represented in this paper for using decision matrix methods.

Design Study: Integer Subtraction Operation Teaching Learning Using Multimedia in Primary School

ERIC Educational Resources Information Center

Aris, Rendi Muhammad; Putri, Ratu Ilma Indra

2017-01-01

This study aims to develop a learning trajectory to help students understand concept of subtraction of integers using multimedia in the fourth grade. This study is thematic integrative learning in Curriculum 2013 PMRI based. The method used is design research consists of three stages; preparing for the experiment, design experiment, retrospective…

75 FR 47592 - Final Test Guideline; Product Performance of Skin-applied Insect Repellents of Insect and Other...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-06

... considerations affecting the design and conduct of repellent studies when human subjects are involved. Any... recommendations for the design and execution of studies to evaluate the performance of pesticide products intended... recommends appropriate study designs and methods for selecting subjects, statistical analysis, and reporting...

Simple uncertainty propagation for early design phase aircraft sizing

NASA Astrophysics Data System (ADS)

Lenz, Annelise

Many designers and systems analysts are aware of the uncertainty inherent in their aircraft sizing studies; however, few incorporate methods to address and quantify this uncertainty. Many aircraft design studies use semi-empirical predictors based on a historical database and contain uncertainty -- a portion of which can be measured and quantified. In cases where historical information is not available, surrogate models built from higher-fidelity analyses often provide predictors for design studies where the computational cost of directly using the high-fidelity analyses is prohibitive. These surrogate models contain uncertainty, some of which is quantifiable. However, rather than quantifying this uncertainty, many designers merely include a safety factor or design margin in the constraints to account for the variability between the predicted and actual results. This can become problematic if a designer does not estimate the amount of variability correctly, which then can result in either an "over-designed" or "under-designed" aircraft. "Under-designed" and some "over-designed" aircraft will likely require design changes late in the process and will ultimately require more time and money to create; other "over-designed" aircraft concepts may not require design changes, but could end up being more costly than necessary. Including and propagating uncertainty early in the design phase so designers can quantify some of the errors in the predictors could help mitigate the extent of this additional cost. The method proposed here seeks to provide a systematic approach for characterizing a portion of the uncertainties that designers are aware of and propagating it throughout the design process in a procedure that is easy to understand and implement. Using Monte Carlo simulations that sample from quantified distributions will allow a systems analyst to use a carpet plot-like approach to make statements like: "The aircraft is 'P'% likely to weigh 'X' lbs or less, given the uncertainties quantified" without requiring the systems analyst to have substantial knowledge of probabilistic methods. A semi-empirical sizing study of a small single-engine aircraft serves as an example of an initial version of this simple uncertainty propagation. The same approach is also applied to a variable-fidelity concept study using a NASA-developed transonic Hybrid Wing Body aircraft.

Development of a Web-Based Health Care Intervention for Patients With Heart Disease: Lessons Learned From a Participatory Design Study

PubMed Central

2017-01-01

Background The use of telemedicine technologies in health care has increased substantially, together with a growing interest in participatory design methods when developing telemedicine approaches. Objective We present lessons learned from a case study involving patients with heart disease and health care professionals in the development of a personalized Web-based health care intervention. Methods We used a participatory design approach inspired by the method for feasibility studies in software development. We collected qualitative data using multiple methods in 3 workshops and analyzed the data using thematic analysis. Participants were 7 patients with diagnosis of heart disease, 2 nurses, 1 physician, 2 systems architects, 3 moderators, and 3 observers. Results We present findings in 2 parts. (1) Outcomes of the participatory design process: users gave valuable feedback on ease of use of the platforms’ tracking tools, platform design, terminology, and insights into patients’ monitoring needs, information and communication technologies skills, and preferences for self-management tools. (2) Experiences from the participatory design process: patients and health care professionals contributed different perspectives, with the patients using an experience-based approach and the health care professionals using a more attitude-based approach. Conclusions The essential lessons learned concern planning and organization of workshops, including the finding that patients engaged actively and willingly in a participatory design process, whereas it was more challenging to include and engage health care professionals. PMID:28526674

Design of large Francis turbine using optimal methods

NASA Astrophysics Data System (ADS)

Flores, E.; Bornard, L.; Tomas, L.; Liu, J.; Couston, M.

2012-11-01

Among a high number of Francis turbine references all over the world, covering the whole market range of heads, Alstom has especially been involved in the development and equipment of the largest power plants in the world : Three Gorges (China -32×767 MW - 61 to 113 m), Itaipu (Brazil- 20x750 MW - 98.7m to 127m) and Xiangjiaba (China - 8x812 MW - 82.5m to 113.6m - in erection). Many new projects are under study to equip new power plants with Francis turbines in order to answer an increasing demand of renewable energy. In this context, Alstom Hydro is carrying out many developments to answer those needs, especially for jumbo units such the planned 1GW type units in China. The turbine design for such units requires specific care by using the state of the art in computation methods and the latest technologies in model testing as well as the maximum feedback from operation of Jumbo plants already in operation. We present in this paper how a large Francis turbine can be designed using specific design methods, including the global and local optimization methods. The design of the spiral case, the tandem cascade profiles, the runner and the draft tube are designed with optimization loops involving a blade design tool, an automatic meshing software and a Navier-Stokes solver, piloted by a genetic algorithm. These automated optimization methods, presented in different papers over the last decade, are nowadays widely used, thanks to the growing computation capacity of the HPC clusters: the intensive use of such optimization methods at the turbine design stage allows to reach very high level of performances, while the hydraulic flow characteristics are carefully studied over the whole water passage to avoid any unexpected hydraulic phenomena.

Qualitative Methods in Mental Health Services Research

PubMed Central

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 paper 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 papers 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 semi-structured 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. PMID:25350675

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

PubMed

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.

Methods for comparative evaluation of propulsion system designs for supersonic aircraft

NASA Technical Reports Server (NTRS)

Tyson, R. M.; Mairs, R. Y.; Halferty, F. D., Jr.; Moore, B. E.; Chaloff, D.; Knudsen, A. W.

1976-01-01

The propulsion system comparative evaluation study was conducted to define a rapid, approximate method for evaluating the effects of propulsion system changes for an advanced supersonic cruise airplane, and to verify the approximate method by comparing its mission performance results with those from a more detailed analysis. A table look up computer program was developed to determine nacelle drag increments for a range of parametric nacelle shapes and sizes. Aircraft sensitivities to propulsion parameters were defined. Nacelle shapes, installed weights, and installed performance was determined for four study engines selected from the NASA supersonic cruise aircraft research (SCAR) engine studies program. Both rapid evaluation method (using sensitivities) and traditional preliminary design methods were then used to assess the four engines. The method was found to compare well with the more detailed analyses.

Simplified LCA and matrix methods in identifying the environmental aspects of a product system.

PubMed

Hur, Tak; Lee, Jiyong; Ryu, Jiyeon; Kwon, Eunsun

2005-05-01

In order to effectively integrate environmental attributes into the product design and development processes, it is crucial to identify the significant environmental aspects related to a product system within a relatively short period of time. In this study, the usefulness of life cycle assessment (LCA) and a matrix method as tools for identifying the key environmental issues of a product system were examined. For this, a simplified LCA (SLCA) method that can be applied to Electrical and Electronic Equipment (EEE) was developed to efficiently identify their significant environmental aspects for eco-design, since a full scale LCA study is usually very detailed, expensive and time-consuming. The environmentally responsible product assessment (ERPA) method, which is one of the matrix methods, was also analyzed. Then, the usefulness of each method in eco-design processes was evaluated and compared using the case studies of the cellular phone and vacuum cleaner systems. It was found that the SLCA and the ERPA methods provided different information but they complemented each other to some extent. The SLCA method generated more information on the inherent environmental characteristics of a product system so that it might be useful for new design/eco-innovation when developing a completely new product or method where environmental considerations play a major role from the beginning. On the other hand, the ERPA method gave more information on the potential for improving a product so that it could be effectively used in eco-redesign which intends to alleviate environmental impacts of an existing product or process.

Applying Semiotic Theories to Graphic Design Education: An Empirical Study on Poster Design Teaching

ERIC Educational Resources Information Center

Yang, Chao-Ming; Hsu, Tzu-Fan

2015-01-01

The rationales behind design are dissimilar to those behind art. Establishing an adequate theoretical foundation for conducting design education can facilitate scientising design methods. Thus, from the perspectives of the semiotic theories proposed by Saussure and Peirce, we investigated graphic design curricula by performing teaching…

Variation in choice of study design: findings from the Epidemiology Design Decision Inventory and Evaluation (EDDIE) survey.

PubMed

Stang, Paul E; Ryan, Patrick B; Overhage, J Marc; Schuemie, Martijn J; Hartzema, Abraham G; Welebob, Emily

2013-10-01

Researchers using observational data to understand drug effects must make a number of analytic design choices that suit the characteristics of the data and the subject of the study. Review of the published literature suggests that there is a lack of consistency even when addressing the same research question in the same database. To characterize the degree of similarity or difference in the method and analysis choices made by observational database research experts when presented with research study scenarios. On-line survey using research scenarios on drug-effect studies to capture method selection and analysis choices that follow a dependency branching based on response to key questions. Voluntary participants experienced in epidemiological study design solicited for participation through registration on the Observational Medical Outcomes Partnership website, membership in particular professional organizations, or links in relevant newsletters. Description (proportion) of respondents selecting particular methods and making specific analysis choices based on individual drug-outcome scenario pairs. The number of questions/decisions differed based on stem questions of study design, time-at-risk, outcome definition, and comparator. There is little consistency across scenarios, by drug or by outcome of interest, in the decisions made for design and analyses in scenarios using large healthcare databases. The most consistent choice was the cohort study design but variability in the other critical decisions was common. There is great variation among epidemiologists in the design and analytical choices that they make when implementing analyses in observational healthcare databases. These findings confirm that it will be important to generate empiric evidence to inform these decisions and to promote a better understanding of the impact of standardization on research implementation.

An improved design method of a tuned mass damper for an in-service footbridge

NASA Astrophysics Data System (ADS)

Shi, Weixing; Wang, Liangkun; Lu, Zheng

2018-03-01

Tuned mass damper (TMD) has a wide range of applications in the vibration control of footbridges. However, the traditional engineering design method may lead to a mistuned TMD. In this paper, an improved TMD design method based on the model updating is proposed. Firstly, the original finite element model (FEM) is studied and the natural characteristics of the in-service or newly built footbridge is identified by field test, and then the original FEM is updated. TMD is designed according to the new updated FEM, and it is optimized according to the simulation on vibration control effects. Finally, the installation and field measurement of TMD are carried out. The improved design method can be applied to both in-service and newly built footbridges. This paper illustrates the improved design method with an engineering example. The frequency identification results of field test and original FEM show that there is a relatively large difference between them. The TMD designed according to the updated FEM has better vibration control effect than the TMD designed according to the original FEM. The site test results show that TMD has good effect on controlling human-induced vibrations.

A minimum cost tolerance allocation method for rocket engines and robust rocket engine design

NASA Technical Reports Server (NTRS)

Gerth, Richard J.

1993-01-01

Rocket engine design follows three phases: systems design, parameter design, and tolerance design. Systems design and parameter design are most effectively conducted in a concurrent engineering (CE) environment that utilize methods such as Quality Function Deployment and Taguchi methods. However, tolerance allocation remains an art driven by experience, handbooks, and rules of thumb. It was desirable to develop and optimization approach to tolerancing. The case study engine was the STME gas generator cycle. The design of the major components had been completed and the functional relationship between the component tolerances and system performance had been computed using the Generic Power Balance model. The system performance nominals (thrust, MR, and Isp) and tolerances were already specified, as were an initial set of component tolerances. However, the question was whether there existed an optimal combination of tolerances that would result in the minimum cost without any degradation in system performance.

Design Fixation and Cooperative Learning in Elementary Engineering Design Project: A Case Study

ERIC Educational Resources Information Center

Luo, Yi

2015-01-01

This paper presents a case study examining 3rd, 4th and 5th graders' design fixation and cooperative learning in an engineering design project. A mixed methods instrument, the Cooperative Learning Observation Protocol (CLOP), was adapted to record frequency and class observation on cooperative learning engagement through detailed field notes.…

Design synthesis and optimization of permanent magnet synchronous machines based on computationally-efficient finite element analysis

NASA Astrophysics Data System (ADS)

Sizov, Gennadi Y.

In this dissertation, a model-based multi-objective optimal design of permanent magnet ac machines, supplied by sine-wave current regulated drives, is developed and implemented. The design procedure uses an efficient electromagnetic finite element-based solver to accurately model nonlinear material properties and complex geometric shapes associated with magnetic circuit design. Application of an electromagnetic finite element-based solver allows for accurate computation of intricate performance parameters and characteristics. The first contribution of this dissertation is the development of a rapid computational method that allows accurate and efficient exploration of large multi-dimensional design spaces in search of optimum design(s). The computationally efficient finite element-based approach developed in this work provides a framework of tools that allow rapid analysis of synchronous electric machines operating under steady-state conditions. In the developed modeling approach, major steady-state performance parameters such as, winding flux linkages and voltages, average, cogging and ripple torques, stator core flux densities, core losses, efficiencies and saturated machine winding inductances, are calculated with minimum computational effort. In addition, the method includes means for rapid estimation of distributed stator forces and three-dimensional effects of stator and/or rotor skew on the performance of the machine. The second contribution of this dissertation is the development of the design synthesis and optimization method based on a differential evolution algorithm. The approach relies on the developed finite element-based modeling method for electromagnetic analysis and is able to tackle large-scale multi-objective design problems using modest computational resources. Overall, computational time savings of up to two orders of magnitude are achievable, when compared to current and prevalent state-of-the-art methods. These computational savings allow one to expand the optimization problem to achieve more complex and comprehensive design objectives. The method is used in the design process of several interior permanent magnet industrial motors. The presented case studies demonstrate that the developed finite element-based approach practically eliminates the need for using less accurate analytical and lumped parameter equivalent circuit models for electric machine design optimization. The design process and experimental validation of the case-study machines are detailed in the dissertation.

LADES: a software for constructing and analyzing longitudinal designs in biomedical research.

PubMed

Vázquez-Alcocer, Alan; Garzón-Cortes, Daniel Ladislao; Sánchez-Casas, Rosa María

2014-01-01

One of the most important steps in biomedical longitudinal studies is choosing a good experimental design that can provide high accuracy in the analysis of results with a minimum sample size. Several methods for constructing efficient longitudinal designs have been developed based on power analysis and the statistical model used for analyzing the final results. However, development of this technology is not available to practitioners through user-friendly software. In this paper we introduce LADES (Longitudinal Analysis and Design of Experiments Software) as an alternative and easy-to-use tool for conducting longitudinal analysis and constructing efficient longitudinal designs. LADES incorporates methods for creating cost-efficient longitudinal designs, unequal longitudinal designs, and simple longitudinal designs. In addition, LADES includes different methods for analyzing longitudinal data such as linear mixed models, generalized estimating equations, among others. A study of European eels is reanalyzed in order to show LADES capabilities. Three treatments contained in three aquariums with five eels each were analyzed. Data were collected from 0 up to the 12th week post treatment for all the eels (complete design). The response under evaluation is sperm volume. A linear mixed model was fitted to the results using LADES. The complete design had a power of 88.7% using 15 eels. With LADES we propose the use of an unequal design with only 14 eels and 89.5% efficiency. LADES was developed as a powerful and simple tool to promote the use of statistical methods for analyzing and creating longitudinal experiments in biomedical research.

Evaluation of the pre-posterior distribution of optimized sampling times for the design of pharmacokinetic studies.

PubMed

Duffull, Stephen B; Graham, Gordon; Mengersen, Kerrie; Eccleston, John

2012-01-01

Information theoretic methods are often used to design studies that aim to learn about pharmacokinetic and linked pharmacokinetic-pharmacodynamic systems. These design techniques, such as D-optimality, provide the optimum experimental conditions. The performance of the optimum design will depend on the ability of the investigator to comply with the proposed study conditions. However, in clinical settings it is not possible to comply exactly with the optimum design and hence some degree of unplanned suboptimality occurs due to error in the execution of the study. In addition, due to the nonlinear relationship of the parameters of these models to the data, the designs are also locally dependent on an arbitrary choice of a nominal set of parameter values. A design that is robust to both study conditions and uncertainty in the nominal set of parameter values is likely to be of use clinically. We propose an adaptive design strategy to account for both execution error and uncertainty in the parameter values. In this study we investigate designs for a one-compartment first-order pharmacokinetic model. We do this in a Bayesian framework using Markov-chain Monte Carlo (MCMC) methods. We consider log-normal prior distributions on the parameters and investigate several prior distributions on the sampling times. An adaptive design was used to find the sampling window for the current sampling time conditional on the actual times of all previous samples.

Weight optimization of an aerobrake structural concept for a lunar transfer vehicle

NASA Technical Reports Server (NTRS)

Bush, Lance B.; Unal, Resit; Rowell, Lawrence F.; Rehder, John J.

1992-01-01

An aerobrake structural concept for a lunar transfer vehicle was weight optimized through the use of the Taguchi design method, finite element analyses, and element sizing routines. Six design parameters were chosen to represent the aerobrake structural configuration. The design parameters included honeycomb core thickness, diameter-depth ratio, shape, material, number of concentric ring frames, and number of radial frames. Each parameter was assigned three levels. The aerobrake structural configuration with the minimum weight was 44 percent less than the average weight of all the remaining satisfactory experimental configurations. In addition, the results of this study have served to bolster the advocacy of the Taguchi method for aerospace vehicle design. Both reduced analysis time and an optimized design demonstrated the applicability of the Taguchi method to aerospace vehicle design.

[Continual improvement of quantitative analytical method development of Panax notogineng saponins based on quality by design].

PubMed

Dai, Sheng-Yun; Xu, Bing; Shi, Xin-Yuan; Xu, Xiang; Sun, Ying-Qiang; Qiao, Yan-Jiang

2017-03-01

This study is aimed to propose a continual improvement strategy based on quality by design (QbD). An ultra high performance liquid chromatography (UPLC) method was developed to accomplish the method transformation from HPLC to UPLC of Panax notogineng saponins (PNS) and achieve the continual improvement of PNS based on QbD, for example. Plackett-Burman screening design and Box-Behnken optimization design were employed to further understand the relationship between the critical method parameters (CMPs) and critical method attributes (CMAs). And then the Bayesian design space was built. The separation degree of the critical peaks (ginsenoside Rg₁ and ginsenoside Re) was over 2.0 and the analysis time was less than 17 min by a method chosen from the design space with 20% of the initial concentration of the acetonitrile, 10 min of the isocratic time and 6%•min⁻¹ of the gradient slope. At last, the optimum method was validated by accuracy profile. Based on the same analytical target profile (ATP), the comparison of HPLC and UPLC including chromatograph method, CMA identification, CMP-CMA model and system suitability test (SST) indicated that the UPLC method could shorten the analysis time, improve the critical separation and satisfy the requirement of the SST. In all, HPLC method could be replaced by UPLC for the quantity analysis of PNS. Copyright© by the Chinese Pharmaceutical Association.

A case study on better iconographic design in electronic medical records' user interface.

PubMed

Tasa, Umut Burcu; Ozcan, Oguzhan; Yantac, Asim Evren; Unluer, Ayca

2008-06-01

It is a known fact that there is a conflict between what users expect and what user interface designers create in the field of medical informatics along with other fields of interface design. The objective of the study is to suggest, from the 'design art' perspective, a method for improving the usability of an electronic medical record (EMR) interface. The suggestion is based on the hypothesis that the user interface of an EMR should be iconographic. The proposed three-step method consists of a questionnaire survey on how hospital users perceive concepts/terms that are going to be used in the EMR user interface. Then icons associated with the terms are designed by a designer, following a guideline which is prepared according to the results of the first questionnaire. Finally the icons are asked back to the target group for proof. A case study was conducted with 64 medical staff and 30 professional designers for the first questionnaire, and with 30 medical staff for the second. In the second questionnaire 7.53 icons out of 10 were matched correctly with a standard deviation of 0.98. Also, all icons except three were matched correctly in at least 83.3% of the forms. The proposed new method differs from the majority of previous studies which are based on user requirements by leaning on user experiments instead. The study demonstrated that the user interface of EMRs should be designed according to a guideline that results from a survey on users' experiences on metaphoric perception of the terms.

Study on optimal design of 210kW traction IPMSM considering thermal demagnetization characteristics

NASA Astrophysics Data System (ADS)

Kim, Young Hyun; Lee, Seong Soo; Cheon, Byung Chul; Lee, Jung Ho

2018-04-01

This study analyses the permanent magnet (PM) used in the rotor of an interior permanent magnet synchronous motor (IPMSM) used for driving an electric railway vehicle (ERV) in the context of controllable shape, temperature, and external magnetic field. The positioning of the inserted magnets is a degree of freedom in the design of such machines. This paper describes a preliminary analysis using parametric finite-element method performed with the aim of achieving an effective design. Next, features of the experimental design, based on methods such as the central-composition method, Box-Behnken and Taguchi method, are explored to optimise the shape of the high power density. The results are used to produce an optimal design for IPMSMs, with design errors minimized using Maxwell 2D, a commercial program. Furthermore, the demagnetization process is analysed based on the magnetization and demagnetization theory for PM materials in computer simulation. The result of the analysis can be used to calculate the magnetization and demagnetization phenomenon according to the input B-H curve. This paper presents the conditions for demagnetization by the external magnetic field in the driving and stopped states, and proposes a simulation method that can analyse demagnetization phenomena according to each condition and design the IPMSM that maximizes efficiency and torque characteristics. Finally, operational characteristics are analysed in terms of the operation patterns of railway vehicles, and control conditions are deduced to achieve maximum efficiency in all sections. This was experimentally verified.

Mechanistic Indicators of Childhood Asthma (MICA): piloting an integrative design for evaluating environmental health

EPA Science Inventory

Background: Modem methods in molecular biology and advanced computational tools show promise in elucidating complex interactions that occur between genes and environmental factors in diseases such as asthma; however appropriately designed studies are critical for these methods to...

Using a Mixed Methods Research Design in a Study Investigating the "Heads of e-Learning" Perspective towards Technology Enhanced Learning

ERIC Educational Resources Information Center

Almpanis, Timos

2016-01-01

This paper outlines the research design, methodology and methods employed in research conducted in the context of Higher Education Institutions (HEIs) and focuses on the Heads of e-Learning (HeLs) perspective about Technology Enhanced Learning (TEL) by campus-based UK institutions. This paper aims to expand on the research design and the research…

Aerodynamic Shape Optimization of Supersonic Aircraft Configurations via an Adjoint Formulation on Parallel Computers

NASA Technical Reports Server (NTRS)

Reuther, James; Alonso, Juan Jose; Rimlinger, Mark J.; Jameson, Antony

1996-01-01

This work describes the application of a control theory-based aerodynamic shape optimization method to the problem of supersonic aircraft design. The design process is greatly accelerated through the use of both control theory and a parallel implementation on distributed memory computers. Control theory is employed to derive the adjoint differential equations whose solution allows for the evaluation of design gradient information at a fraction of the computational cost required by previous design methods. The resulting problem is then implemented on parallel distributed memory architectures using a domain decomposition approach, an optimized communication schedule, and the MPI (Message Passing Interface) Standard for portability and efficiency. The final result achieves very rapid aerodynamic design based on higher order computational fluid dynamics methods (CFD). In our earlier studies, the serial implementation of this design method was shown to be effective for the optimization of airfoils, wings, wing-bodies, and complex aircraft configurations using both the potential equation and the Euler equations. In our most recent paper, the Euler method was extended to treat complete aircraft configurations via a new multiblock implementation. Furthermore, during the same conference, we also presented preliminary results demonstrating that this basic methodology could be ported to distributed memory parallel computing architectures. In this paper, our concern will be to demonstrate that the combined power of these new technologies can be used routinely in an industrial design environment by applying it to the case study of the design of typical supersonic transport configurations. A particular difficulty of this test case is posed by the propulsion/airframe integration.

Using conceptual work products of health care to design health IT.

PubMed

Berry, Andrew B L; Butler, Keith A; Harrington, Craig; Braxton, Melissa O; Walker, Amy J; Pete, Nikki; Johnson, Trevor; Oberle, Mark W; Haselkorn, Jodie; Paul Nichol, W; Haselkorn, Mark

2016-02-01

This paper introduces a new, model-based design method for interactive health information technology (IT) systems. This method extends workflow models with models of conceptual work products. When the health care work being modeled is substantially cognitive, tacit, and complex in nature, graphical workflow models can become too complex to be useful to designers. Conceptual models complement and simplify workflows by providing an explicit specification for the information product they must produce. We illustrate how conceptual work products can be modeled using standard software modeling language, which allows them to provide fundamental requirements for what the workflow must accomplish and the information that a new system should provide. Developers can use these specifications to envision how health IT could enable an effective cognitive strategy as a workflow with precise information requirements. We illustrate the new method with a study conducted in an outpatient multiple sclerosis (MS) clinic. This study shows specifically how the different phases of the method can be carried out, how the method allows for iteration across phases, and how the method generated a health IT design for case management of MS that is efficient and easy to use. Copyright © 2015 Elsevier Inc. All rights reserved.

Optical designs for MWIR and four quadrant detectors by using beam steering methods in missile applications

NASA Astrophysics Data System (ADS)

Sakarya, Doǧan Uǧur

2017-10-01

Beam steering optical arrangement needs less volume envelope for same field of regard than other gimbal approaches. Both for imaging and four quadrant missile applications, volume is critical parameter limiting system performance. Therefore, a conceptual design of beam steering method has been focused on both imaging and four quadrant missiles. In this study; four different optical designs have been made by using both beam steering and regular method for mid-wave infra-red imaging and four quadrant systems. Optical designs performances have been illustrated in simulation results. By using manufactured Risley prisms, some experimental results are conducted to compare simulations results.

Research on an innovative design model

NASA Astrophysics Data System (ADS)

Fu, Y.; Fang, H.

2018-03-01

The design methods of furniture are different from east to west; it has been the hotspot of the scholars. However, in terms of the theory of modern design innovation, neither the early creation theory, the modern design theory, nor the widely applied TRIZ theory can fully fit the modern furniture design innovation, so it is urgent to study the modern furniture design theory. This paper is based on the idea of TRIZ theory, using lots of literatures as data, and uses the method of statistical stratification to analyze and sort out the research of modern sitting equipment, and finally put forward the modern furniture design model, which provides new ideas and perspectives for the modern design of Chinese furniture.

Statistical analysis and application of quasi experiments to antimicrobial resistance intervention studies.

PubMed

Shardell, Michelle; Harris, Anthony D; El-Kamary, Samer S; Furuno, Jon P; Miller, Ram R; Perencevich, Eli N

2007-10-01

Quasi-experimental study designs are frequently used to assess interventions that aim to limit the emergence of antimicrobial-resistant pathogens. However, previous studies using these designs have often used suboptimal statistical methods, which may result in researchers making spurious conclusions. Methods used to analyze quasi-experimental data include 2-group tests, regression analysis, and time-series analysis, and they all have specific assumptions, data requirements, strengths, and limitations. An example of a hospital-based intervention to reduce methicillin-resistant Staphylococcus aureus infection rates and reduce overall length of stay is used to explore these methods.

NTP technical report on comparative toxicity and carcinogenicity studies of o-nitrotoluene and o-toluidine hydrochloride. (Cas Nos. 88-72-2 and 636-21-5) administered in feed to male f344/n rats

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

Elwell, M.R.

1996-03-01

;Contents: Introduction (Physical and Chemical Properties, Production, Use, and Exposure, Disposition and Metabolism, Toxicity, Study Rationale and Design); Materials and Methods (Procurement and Characterization of 0-Nitroluene and o-Toluidine Hydrochloride, Preparation and Analysis of Dose Formulations, Preparation of Antibiotic Mixture, Toxicity Study Designs, Statistical Methods, Quality Assurance); Results (26-Week Feed Studies in Male F344/N Rats).

Using Participatory and Service Design to Identify Emerging Needs and Perceptions of Library Services among Science and Engineering Researchers Based at a Satellite Campus

ERIC Educational Resources Information Center

Johnson, Andrew; Kuglitsch, Rebecca; Bresnahan, Megan

2015-01-01

This study used participatory and service design methods to identify emerging research needs and existing perceptions of library services among science and engineering faculty, post-graduate, and graduate student researchers based at a satellite campus at the University of Colorado Boulder. These methods, and the results of the study, allowed us…

Assessment of Day Caring Methods among Civil Servant Mothers of Reproductive Age in Lagos State Nigeria

ERIC Educational Resources Information Center

Akinnubi, Caroline Funmbi

2016-01-01

This study examined the day caring methods among the civil servants of reproductive age with children between three months to four years in Lagos State Nigeria. The research design employed for this study was a descriptive research design. A total number of 212 teachers and 128 ministry workers making a total of 340 reproductive age mothers were…

Insights on Supporting Learning during Computing Science and Engineering Students' Transition to University: A Design-Oriented, Mixed Methods Exploration of Instructor and Student Perspectives

ERIC Educational Resources Information Center

Guloy, Sheryl; Salimi, Farimah; Cukierman, Diana; McGee Thompson, Donna

2017-01-01

Using a design-based orientation, this mixed-method study explored ways to support computing science and engineering students whose study strategies may be inadequate to meet coursework expectations. Learning support workshops, paired with university courses, have been found to assist students as they transition to university learning, thereby…

Using Blended Teaching to Teach Blended Learning: Lessons Learned from Pre-Service Teachers in an Instructional Methods Course

ERIC Educational Resources Information Center

Shand, Kristen; Farrelly, Susan Glassett

2017-01-01

In this study, we explore the design and delivery of a blended social studies teaching methods course to examine the elements of the blended design that pre-service teachers found most constructive. In focus groups at the completion of the course, pre-service teachers were asked to reflect on their experience in the blended course, identify the…

Insight into Evaluation Practice: A Content Analysis of Designs and Methods Used in Evaluation Studies Published in North American Evaluation-Focused Journals

ERIC Educational Resources Information Center

Christie, Christina A.; Fleischer, Dreolin Nesbitt

2010-01-01

To describe the recent practice of evaluation, specifically method and design choices, the authors performed a content analysis on 117 evaluation studies published in eight North American evaluation-focused journals for a 3-year period (2004-2006). The authors chose this time span because it follows the scientifically based research (SBR)…

Constructing experimental designs for discrete-choice experiments: report of the ISPOR Conjoint Analysis Experimental Design Good Research Practices Task Force.

PubMed

Reed Johnson, F; Lancsar, Emily; Marshall, Deborah; Kilambi, Vikram; Mühlbacher, Axel; Regier, Dean A; Bresnahan, Brian W; Kanninen, Barbara; Bridges, John F P

2013-01-01

Stated-preference methods are a class of evaluation techniques for studying the preferences of patients and other stakeholders. While these methods span a variety of techniques, conjoint-analysis methods-and particularly discrete-choice experiments (DCEs)-have become the most frequently applied approach in health care in recent years. Experimental design is an important stage in the development of such methods, but establishing a consensus on standards is hampered by lack of understanding of available techniques and software. This report builds on the previous ISPOR Conjoint Analysis Task Force Report: Conjoint Analysis Applications in Health-A Checklist: A Report of the ISPOR Good Research Practices for Conjoint Analysis Task Force. This report aims to assist researchers specifically in evaluating alternative approaches to experimental design, a difficult and important element of successful DCEs. While this report does not endorse any specific approach, it does provide a guide for choosing an approach that is appropriate for a particular study. In particular, it provides an overview of the role of experimental designs for the successful implementation of the DCE approach in health care studies, and it provides researchers with an introduction to constructing experimental designs on the basis of study objectives and the statistical model researchers have selected for the study. The report outlines the theoretical requirements for designs that identify choice-model preference parameters and summarizes and compares a number of available approaches for constructing experimental designs. The task-force leadership group met via bimonthly teleconferences and in person at ISPOR meetings in the United States and Europe. An international group of experimental-design experts was consulted during this process to discuss existing approaches for experimental design and to review the task force's draft reports. In addition, ISPOR members contributed to developing a consensus report by submitting written comments during the review process and oral comments during two forum presentations at the ISPOR 16th and 17th Annual International Meetings held in Baltimore (2011) and Washington, DC (2012). Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Achieving integration in mixed methods designs-principles and practices.

PubMed

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.

Explaining nutritional habits and behaviors of low socioeconomic status women in Sanandaj: a qualitative content analysis

PubMed Central

Abdi, Nasrin; Sadeghi, Roya; Zamani-alavijeh, Fereshteh; Taghdisi, Mohammad Hossein; Shojaeezadeh, Davoud

2016-01-01

Introduction Health and behavior are closely related subjects because disease is typically rooted in individuals’ unhealthy behaviors and habits. This study aims to identify women’s nutritional habits and behaviors in order to design interventions to promote nutritional literacy. Methods This qualitative research is part of a mixed method (quantitative-qualitative) study, conducted based on content analysis. Data were collected using semistructured interviews, group discussions, and in-depth interviews with married women, aged 18–50 years, who were referred to four health care centers in Sanandaj in 2013–2014. Results Nutritional habits and behaviors of participants were classified into two categories: representation of nutritional behavior based on consumption pattern and representation of nutritional behavior based on consumption method. For the former, eight consumption pattern subcategories were formed: meat, dairy, fast food, local foods, fruits and vegetables, soft drinks, and oils. The latter (representation of nutritional behavior based on consumption method), included two subcategories: consumption method in line with health and consumption method inconsistent with health. Conclusion Results of this qualitative study provide a solid foundation for development and designing interventions to nutritional literacy promotion based on needs. The designed intervention to healthy nutritional behavior should be based on empowering women and providing facilitator factors of a healthy diet. While designing this study, with a holistic perspective, individual and social aspects of a healthy diet should be taken into account. PMID:26955443

Teaching E-Commerce Web Page Evaluation and Design: A Pilot Study Using Tourism Destination Sites

ERIC Educational Resources Information Center

Susser, Bernard; Ariga, Taeko

2006-01-01

This study explores a teaching method for improving business students' skills in e-commerce page evaluation and making Web design majors aware of business content issues through cooperative learning. Two groups of female students at a Japanese university studying either tourism or Web page design were assigned tasks that required cooperation to…

Instructional Design and E-Learning: Examining Learners' Perspective in Malaysian Institutions of Higher Learning

ERIC Educational Resources Information Center

Hussin, Husnayati; Bunyarit, Fatimah; Hussein, Ramlah

2009-01-01

Purpose: This study aims to investigate the elements of effective instructional design in an e-learning environment in selected Malaysian higher learning institutions. In addition, the study also seeks to investigate the e-learning use behaviour among these e-learners. Design/methodology/approach: The study used the interview method of data…

Dose-finding design for multi-drug combinations

PubMed Central

Wages, Nolan A; Conaway, Mark R; O'Quigley, John

2012-01-01

Background Most of the current designs used for Phase I dose finding trials in oncology will either involve only a single cytotoxic agent or will impose some implicit ordering among the doses. The goal of the studies is to estimate the maximum tolerated dose (MTD), the highest dose that can be administered with an acceptable level of toxicity. A key working assumption of these methods is the monotonicity of the dose–toxicity curve. Purpose Here we consider situations in which the monotonicity assumption may fail. These studies are becoming increasingly common in practice, most notably, in phase I trials that involve combinations of agents. Our focus is on studies where there exist pairs of treatment combinations for which the ordering of the probabilities of a dose-limiting toxicity cannot be known a priori. Methods We describe a new dose-finding design which can be used for multiple-drug trials and can be applied to this kind of problem. Our methods proceed by laying out all possible orderings of toxicity probabilities that are consistent with the known orderings among treatment combinations and allowing the continual reassessment method (CRM) to provide efficient estimates of the MTD within these orders. The design can be seen to simplify to the CRM when the full ordering is known. Results We study the properties of the design via simulations that provide comparisons to the Bayesian approach to partial orders (POCRM) of Wages, Conaway, and O'Quigley. The POCRM was shown to perform well when compared to other suggested methods for partial orders. Therefore, we comapre our approach to it in order to assess the performance of the new design. Limitations A limitation concerns the number of possible orders. There are dose-finding studies with combinations of agents that can lead to a large number of possible orders. In this case, it may not be feasible to work with all possible orders. Conclusions The proposed design demonstrates the ability to effectively estimate MTD combinations in partially ordered dosefinding studies. Because it relaxes the monotonicity assumption, it can be considered a multivariate generalization of the CRM. Hence, it can serve as a link between single and multiple-agent dosefinding trials. PMID:21652689

User Interaction in Semi-Automatic Segmentation of Organs at Risk: a Case Study in Radiotherapy.

PubMed

Ramkumar, Anjana; Dolz, Jose; Kirisli, Hortense A; Adebahr, Sonja; Schimek-Jasch, Tanja; Nestle, Ursula; Massoptier, Laurent; Varga, Edit; Stappers, Pieter Jan; Niessen, Wiro J; Song, Yu

2016-04-01

Accurate segmentation of organs at risk is an important step in radiotherapy planning. Manual segmentation being a tedious procedure and prone to inter- and intra-observer variability, there is a growing interest in automated segmentation methods. However, automatic methods frequently fail to provide satisfactory result, and post-processing corrections are often needed. Semi-automatic segmentation methods are designed to overcome these problems by combining physicians' expertise and computers' potential. This study evaluates two semi-automatic segmentation methods with different types of user interactions, named the "strokes" and the "contour", to provide insights into the role and impact of human-computer interaction. Two physicians participated in the experiment. In total, 42 case studies were carried out on five different types of organs at risk. For each case study, both the human-computer interaction process and quality of the segmentation results were measured subjectively and objectively. Furthermore, different measures of the process and the results were correlated. A total of 36 quantifiable and ten non-quantifiable correlations were identified for each type of interaction. Among those pairs of measures, 20 of the contour method and 22 of the strokes method were strongly or moderately correlated, either directly or inversely. Based on those correlated measures, it is concluded that: (1) in the design of semi-automatic segmentation methods, user interactions need to be less cognitively challenging; (2) based on the observed workflows and preferences of physicians, there is a need for flexibility in the interface design; (3) the correlated measures provide insights that can be used in improving user interaction design.

On-Line Critiques in Collaborative Design Studio

ERIC Educational Resources Information Center

Sagun, Aysu; Demirkan, Halime

2009-01-01

In this study, the Design Collaboration Model (DCM) was developed to provide a medium for the on-line collaboration of the design courses. The model was based on the situated and reflective practice characteristics of the design process. The segmentation method was used to analyse the design process observed both in the design diaries and the…

Study of flutter related computational procedures for minimum weight structural sizing of advanced aircraft

NASA Technical Reports Server (NTRS)

Oconnell, R. F.; Hassig, H. J.; Radovcich, N. A.

1976-01-01

Results of a study of the development of flutter modules applicable to automated structural design of advanced aircraft configurations, such as a supersonic transport, are presented. Automated structural design is restricted to automated sizing of the elements of a given structural model. It includes a flutter optimization procedure; i.e., a procedure for arriving at a structure with minimum mass for satisfying flutter constraints. Methods of solving the flutter equation and computing the generalized aerodynamic force coefficients in the repetitive analysis environment of a flutter optimization procedure are studied, and recommended approaches are presented. Five approaches to flutter optimization are explained in detail and compared. An approach to flutter optimization incorporating some of the methods discussed is presented. Problems related to flutter optimization in a realistic design environment are discussed and an integrated approach to the entire flutter task is presented. Recommendations for further investigations are made. Results of numerical evaluations, applying the five methods of flutter optimization to the same design task, are presented.

Designing occupancy studies when false-positive detections occur

USGS Publications Warehouse

Clement, Matthew

2016-01-01

1.Recently, estimators have been developed to estimate occupancy probabilities when false-positive detections occur during presence-absence surveys. Some of these estimators combine different types of survey data to improve estimates of occupancy. With these estimators, there is a tradeoff between the number of sample units surveyed, and the number and type of surveys at each sample unit. Guidance on efficient design of studies when false positives occur is unavailable. 2.For a range of scenarios, I identified survey designs that minimized the mean square error of the estimate of occupancy. I considered an approach that uses one survey method and two observation states and an approach that uses two survey methods. For each approach, I used numerical methods to identify optimal survey designs when model assumptions were met and parameter values were correctly anticipated, when parameter values were not correctly anticipated, and when the assumption of no unmodelled detection heterogeneity was violated. 3.Under the approach with two observation states, false positive detections increased the number of recommended surveys, relative to standard occupancy models. If parameter values could not be anticipated, pessimism about detection probabilities avoided poor designs. Detection heterogeneity could require more or fewer repeat surveys, depending on parameter values. If model assumptions were met, the approach with two survey methods was inefficient. However, with poor anticipation of parameter values, with detection heterogeneity, or with removal sampling schemes, combining two survey methods could improve estimates of occupancy. 4.Ignoring false positives can yield biased parameter estimates, yet false positives greatly complicate the design of occupancy studies. Specific guidance for major types of false-positive occupancy models, and for two assumption violations common in field data, can conserve survey resources. This guidance can be used to design efficient monitoring programs and studies of species occurrence, species distribution, or habitat selection, when false positives occur during surveys.

Explaining nutritional habits and behaviors of low socioeconomic status women in Sanandaj: a qualitative content analysis.

PubMed

Abdi, Nasrin; Sadeghi, Roya; Zamani-Alavijeh, Fereshteh; Taghdisi, Mohammad Hossein; Shojaeezadeh, Davoud

2016-01-01

Health and behavior are closely related subjects because disease is typically rooted in individuals' unhealthy behaviors and habits. This study aims to identify women's nutritional habits and behaviors in order to design interventions to promote nutritional literacy. This qualitative research is part of a mixed method (quantitative-qualitative) study, conducted based on content analysis. Data were collected using semistructured interviews, group discussions, and in-depth interviews with married women, aged 18-50 years, who were referred to four health care centers in Sanandaj in 2013-2014. Nutritional habits and behaviors of participants were classified into two categories: representation of nutritional behavior based on consumption pattern and representation of nutritional behavior based on consumption method. For the former, eight consumption pattern subcategories were formed: meat, dairy, fast food, local foods, fruits and vegetables, soft drinks, and oils. The latter (representation of nutritional behavior based on consumption method), included two subcategories: consumption method in line with health and consumption method inconsistent with health. Results of this qualitative study provide a solid foundation for development and designing interventions to nutritional literacy promotion based on needs. The designed intervention to healthy nutritional behavior should be based on empowering women and providing facilitator factors of a healthy diet. While designing this study, with a holistic perspective, individual and social aspects of a healthy diet should be taken into account.

Methods to Enhance Students' Entrepreneurial Mindset: A Swedish Example

ERIC Educational Resources Information Center

Lindberg, Erik; Bohman, Håkan; Hultén, Peter

2017-01-01

Purpose: The purpose of this study is to examine the effects of intervention methods in an entrepreneurship education (EE) course that was designed to enhance the students' entrepreneurial mindset by targeting their opportunity identification, creativity and risk management capabilities (RMC). Design/methodology/approach: The authors formulate…

Methods of Microcomputer Research in Early Childhood Special Education.

ERIC Educational Resources Information Center

Fujiura, Glenn; Johnson, Lawrence J.

1986-01-01

The review of some recent studies on use of microcomputers in early childhood special education highlights methodological issues including the qualitative quantitative distinction and the interdependence of research design and interpretation. Imbedding qualitative methods into quasi- or true-experimental designs can provide more information than…

Exposure assessment for endocrine disruptors: some considerations in the design of studies.

PubMed Central

Rice, Carol; Birnbaum, Linda S; Cogliano, James; Mahaffey, Kathryn; Needham, Larry; Rogan, Walter J; vom Saal, Frederick S

2003-01-01

In studies designed to evaluate exposure-response relationships in children's development from conception through puberty, multiple factors that affect the generation of meaningful exposure metrics must be considered. These factors include multiple routes of exposure; the timing, frequency, and duration of exposure; need for qualitative and quantitative data; sample collection and storage protocols; and the selection and documentation of analytic methods. The methods for exposure data collection and analysis must be sufficiently robust to accommodate the a priori hypotheses to be tested, as well as hypotheses generated from the data. A number of issues that must be considered in study design are summarized here. PMID:14527851

The effects of user factors and symbol referents on public symbol design using the stereotype production method.

PubMed

Ng, Annie W Y; Siu, Kin Wai Michael; Chan, Chetwyn C H

2012-01-01

This study investigated the influence of user factors and symbol referents on public symbol design among older people, using the stereotype production method for collecting user ideas during the symbol design process. Thirty-one older adults were asked to draw images based on 28 public symbol referents and to indicate their familiarity with and ease with which they visualised each referent. Differences were found between the pictorial solutions generated by males and females. However, symbol design was not influenced by participants' education level, vividness of visual imagery, object imagery preference or spatial imagery preference. Both familiar and unfamiliar referents were illustrated pictorially without much difficulty by users. The more visual the referent, the less difficulty the users had in illustrating it. The findings of this study should aid the optimisation of the stereotype production method for user-involved symbol design. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Near-optimal experimental design for model selection in systems biology.

PubMed

Busetto, Alberto Giovanni; Hauser, Alain; Krummenacher, Gabriel; Sunnåker, Mikael; Dimopoulos, Sotiris; Ong, Cheng Soon; Stelling, Jörg; Buhmann, Joachim M

2013-10-15

Biological systems are understood through iterations of modeling and experimentation. Not all experiments, however, are equally valuable for predictive modeling. This study introduces an efficient method for experimental design aimed at selecting dynamical models from data. Motivated by biological applications, the method enables the design of crucial experiments: it determines a highly informative selection of measurement readouts and time points. We demonstrate formal guarantees of design efficiency on the basis of previous results. By reducing our task to the setting of graphical models, we prove that the method finds a near-optimal design selection with a polynomial number of evaluations. Moreover, the method exhibits the best polynomial-complexity constant approximation factor, unless P = NP. We measure the performance of the method in comparison with established alternatives, such as ensemble non-centrality, on example models of different complexity. Efficient design accelerates the loop between modeling and experimentation: it enables the inference of complex mechanisms, such as those controlling central metabolic operation. Toolbox 'NearOED' available with source code under GPL on the Machine Learning Open Source Software Web site (mloss.org).

Towards evidence-based computational statistics: lessons from clinical research on the role and design of real-data benchmark studies.

PubMed

Boulesteix, Anne-Laure; Wilson, Rory; Hapfelmeier, Alexander

2017-09-09

The goal of medical research is to develop interventions that are in some sense superior, with respect to patient outcome, to interventions currently in use. Similarly, the goal of research in methodological computational statistics is to develop data analysis tools that are themselves superior to the existing tools. The methodology of the evaluation of medical interventions continues to be discussed extensively in the literature and it is now well accepted that medicine should be at least partly "evidence-based". Although we statisticians are convinced of the importance of unbiased, well-thought-out study designs and evidence-based approaches in the context of clinical research, we tend to ignore these principles when designing our own studies for evaluating statistical methods in the context of our methodological research. In this paper, we draw an analogy between clinical trials and real-data-based benchmarking experiments in methodological statistical science, with datasets playing the role of patients and methods playing the role of medical interventions. Through this analogy, we suggest directions for improvement in the design and interpretation of studies which use real data to evaluate statistical methods, in particular with respect to dataset inclusion criteria and the reduction of various forms of bias. More generally, we discuss the concept of "evidence-based" statistical research, its limitations and its impact on the design and interpretation of real-data-based benchmark experiments. We suggest that benchmark studies-a method of assessment of statistical methods using real-world datasets-might benefit from adopting (some) concepts from evidence-based medicine towards the goal of more evidence-based statistical research.

Stereo Sound Field Controller Design Using Partial Model Matching on the Frequency Domain

NASA Astrophysics Data System (ADS)

Kumon, Makoto; Miike, Katsuhiro; Eguchi, Kazuki; Mizumoto, Ikuro; Iwai, Zenta

The objective of sound field control is to make the acoustic characteristics of a listening room close to those of the desired system. Conventional methods apply feedforward controllers, such as digital filters, to achieve this objective. However, feedback controllers are also necessary in order to attenuate noise or to compensate the uncertainty of the acoustic characteristics of the listening room. Since acoustic characteristics are well modeled on the frequency domain, it is efficient to design controllers with respect to frequency responses, but it is difficult to design a multi input multi output (MIMO) control system on a wide frequency domain. In the present study, a partial model matching method on the frequency domain was adopted because this method requires only sampled data, rather than complex mathematical models of the plant, in order to design controllers for MIMO systems. The partial model matching method was applied to design two-degree-of-freedom controllers for acoustic equalization and noise reduction. Experiments demonstrated effectiveness of the proposed method.

Corrected score estimation in the proportional hazards model with misclassified discrete covariates

PubMed Central

Zucker, David M.; Spiegelman, Donna

2013-01-01

SUMMARY We consider Cox proportional hazards regression when the covariate vector includes error-prone discrete covariates along with error-free covariates, which may be discrete or continuous. The misclassification in the discrete error-prone covariates is allowed to be of any specified form. Building on the work of Nakamura and his colleagues, we present a corrected score method for this setting. The method can handle all three major study designs (internal validation design, external validation design, and replicate measures design), both functional and structural error models, and time-dependent covariates satisfying a certain ‘localized error’ condition. We derive the asymptotic properties of the method and indicate how to adjust the covariance matrix of the regression coefficient estimates to account for estimation of the misclassification matrix. We present the results of a finite-sample simulation study under Weibull survival with a single binary covariate having known misclassification rates. The performance of the method described here was similar to that of related methods we have examined in previous works. Specifically, our new estimator performed as well as or, in a few cases, better than the full Weibull maximum likelihood estimator. We also present simulation results for our method for the case where the misclassification probabilities are estimated from an external replicate measures study. Our method generally performed well in these simulations. The new estimator has a broader range of applicability than many other estimators proposed in the literature, including those described in our own earlier work, in that it can handle time-dependent covariates with an arbitrary misclassification structure. We illustrate the method on data from a study of the relationship between dietary calcium intake and distal colon cancer. PMID:18219700

Perspective: Randomized Controlled Trials Are Not a Panacea for Diet-Related Research12

PubMed Central

Hébert, James R; Frongillo, Edward A; Adams, Swann A; Turner-McGrievy, Gabrielle M; Hurley, Thomas G; Miller, Donald R; Ockene, Ira S

2016-01-01

Research into the role of diet in health faces a number of methodologic challenges in the choice of study design, measurement methods, and analytic options. Heavier reliance on randomized controlled trial (RCT) designs is suggested as a way to solve these challenges. We present and discuss 7 inherent and practical considerations with special relevance to RCTs designed to study diet: 1) the need for narrow focus; 2) the choice of subjects and exposures; 3) blinding of the intervention; 4) perceived asymmetry of treatment in relation to need; 5) temporal relations between dietary exposures and putative outcomes; 6) strict adherence to the intervention protocol, despite potential clinical counter-indications; and 7) the need to maintain methodologic rigor, including measuring diet carefully and frequently. Alternatives, including observational studies and adaptive intervention designs, are presented and discussed. Given high noise-to-signal ratios interjected by using inaccurate assessment methods in studies with weak or inappropriate study designs (including RCTs), it is conceivable and indeed likely that effects of diet are underestimated. No matter which designs are used, studies will require continued improvement in the assessment of dietary intake. As technology continues to improve, there is potential for enhanced accuracy and reduced user burden of dietary assessments that are applicable to a wide variety of study designs, including RCTs. PMID:27184269

Recommendations for research design of telehealth studies.

PubMed

Chumbler, Neale R; Kobb, Rita; Brennan, David M; Rabinowitz, Terry

2008-11-01

Properly designed randomized controlled trials (RCTs) are the gold standard to use when examining the effectiveness of telehealth interventions on clinical outcomes. Some published telehealth studies have employed well-designed RCTs. However, such methods are not always feasible and practical in particular settings. This white paper addresses not only the need for properly designed RCTs, but also offers alternative research designs, such as quasi-experimental designs, and statistical techniques that can be employed to rigorously assess the effectiveness of telehealth studies. This paper further offers design and measurement recommendations aimed at and relevant to administrative decision-makers, policymakers, and practicing clinicians.

Probabilistic Design Storm Method for Improved Flood Estimation in Ungauged Catchments

NASA Astrophysics Data System (ADS)

Berk, Mario; Å pačková, Olga; Straub, Daniel

2017-12-01

The design storm approach with event-based rainfall-runoff models is a standard method for design flood estimation in ungauged catchments. The approach is conceptually simple and computationally inexpensive, but the underlying assumptions can lead to flawed design flood estimations. In particular, the implied average recurrence interval (ARI) neutrality between rainfall and runoff neglects uncertainty in other important parameters, leading to an underestimation of design floods. The selection of a single representative critical rainfall duration in the analysis leads to an additional underestimation of design floods. One way to overcome these nonconservative approximations is the use of a continuous rainfall-runoff model, which is associated with significant computational cost and requires rainfall input data that are often not readily available. As an alternative, we propose a novel Probabilistic Design Storm method that combines event-based flood modeling with basic probabilistic models and concepts from reliability analysis, in particular the First-Order Reliability Method (FORM). The proposed methodology overcomes the limitations of the standard design storm approach, while utilizing the same input information and models without excessive computational effort. Additionally, the Probabilistic Design Storm method allows deriving so-called design charts, which summarize representative design storm events (combinations of rainfall intensity and other relevant parameters) for floods with different return periods. These can be used to study the relationship between rainfall and runoff return periods. We demonstrate, investigate, and validate the method by means of an example catchment located in the Bavarian Pre-Alps, in combination with a simple hydrological model commonly used in practice.

Using network screening methods to determine locations with specific safety issues: A design consistency case study.

PubMed

Butsick, Andrew J; Wood, Jonathan S; Jovanis, Paul P

2017-09-01

The Highway Safety Manual provides multiple methods that can be used to identify sites with promise (SWiPs) for safety improvement. However, most of these methods cannot be used to identify sites with specific problems. Furthermore, given that infrastructure funding is often specified for use related to specific problems/programs, a method for identifying SWiPs related to those programs would be very useful. This research establishes a method for Identifying SWiPs with specific issues. This is accomplished using two safety performance functions (SPFs). This method is applied to identifying SWiPs with geometric design consistency issues. Mixed effects negative binomial regression was used to develop two SPFs using 5 years of crash data and over 8754km of two-lane rural roadway. The first SPF contained typical roadway elements while the second contained additional geometric design consistency parameters. After empirical Bayes adjustments, sites with promise (SWiPs) were identified. The disparity between SWiPs identified by the two SPFs was evident; 40 unique sites were identified by each model out of the top 220 segments. By comparing sites across the two models, candidate road segments can be identified where a lack design consistency may be contributing to an increase in expected crashes. Practitioners can use this method to more effectively identify roadway segments suffering from reduced safety performance due to geometric design inconsistency, with detailed engineering studies of identified sites required to confirm the initial assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Qualitative Measurement towards Emotional Feeling of Design for Product Development

NASA Astrophysics Data System (ADS)

Syaifoelida, Fevi; Megat Hamdan, M. A. M.; Murrad, M.; Aminuddin, Hazim

2018-04-01

To compete in today’s ever-growing technology market, a product needs to be well presentable to the customers. It is a challenge to design a product that is able to attract customer’s attention and to build their loyalty towards the product. A product needs to be designed with focus to give the maximum level of satisfaction to the end user which is the customer. That is the focus of this paper, to achieve customer’s satisfaction, by studying feelings and emotional value related to product designs using Kansei Engineering (KE) and to test how important that product element (level of satisfaction) by using Kano Method (KM). KE is a method of translating human emotions and feelings into product development. The method studies the human interaction and responses when a customer sees a product, then translates it into a new improved design. However, KE cannot stand on its own. It did not specify in which extends the feeling or emotions is important in a product. After we had the design appearance parameters from KE and existing design evaluation, it need to be classified which is more important than the other is. That is why Kano Method (KM) will also be used. Since this scope of study towards an emotional feeling of design (existing part/appearance) in Kano categories not in deep function of technical requirement, so KM will help to classify parts of product into categories, which part will give fully satisfaction while using it. It studies the more important attributes considered by the customers for improvement. The objective is to find out the design priority guide that can be used to maximize customer’s satisfaction. Therefore, in order to apply the qualitative measurement idea into the real situation, the headphone product is chosen (popular among students) as the product (the appearance of part, feeling when use it) domain for this study. As the results progressed, it was found out that the headband part of headphone is the most important part of the product. It needs to be durable and comfortably designed to give full satisfaction while using (Kano-functional). The research and development (R&D), and designing process of a product can be improved greatly to increase the customer’s satisfaction by capturing their emotional feeling in physiological design.

First-order design of geodetic networks using the simulated annealing method

NASA Astrophysics Data System (ADS)

Berné, J. L.; Baselga, S.

2004-09-01

The general problem of the optimal design for a geodetic network subject to any extrinsic factors, namely the first-order design problem, can be dealt with as a numeric optimization problem. The classic theory of this problem and the optimization methods are revised. Then the innovative use of the simulated annealing method, which has been successfully applied in other fields, is presented for this classical geodetic problem. This method, belonging to iterative heuristic techniques in operational research, uses a thermodynamical analogy to crystalline networks to offer a solution that converges probabilistically to the global optimum. Basic formulation and some examples are studied.

Methods for designing interventions to change healthcare professionals' behaviour: a systematic review.

PubMed

Colquhoun, Heather L; Squires, Janet E; Kolehmainen, Niina; Fraser, Cynthia; Grimshaw, Jeremy M

2017-03-04

Systematic reviews consistently indicate that interventions to change healthcare professional (HCP) behaviour are haphazardly designed and poorly specified. Clarity about methods for designing and specifying interventions is needed. The objective of this review was to identify published methods for designing interventions to change HCP behaviour. A search of MEDLINE, Embase, and PsycINFO was conducted from 1996 to April 2015. Using inclusion/exclusion criteria, a broad screen of abstracts by one rater was followed by a strict screen of full text for all potentially relevant papers by three raters. An inductive approach was first applied to the included studies to identify commonalities and differences between the descriptions of methods across the papers. Based on this process and knowledge of related literatures, we developed a data extraction framework that included, e.g. level of change (e.g. individual versus organization); context of development; a brief description of the method; tasks included in the method (e.g. barrier identification, component selection, use of theory). 3966 titles and abstracts and 64 full-text papers were screened to yield 15 papers included in the review, each outlining one design method. All of the papers reported methods developed within a specific context. Thirteen papers included barrier identification and 13 included linking barriers to intervention components; although not the same 13 papers. Thirteen papers targeted individual HCPs with only one paper targeting change across individual, organization, and system levels. The use of theory and user engagement were included in 13/15 and 13/15 papers, respectively. There is an agreement across methods of four tasks that need to be completed when designing individual-level interventions: identifying barriers, selecting intervention components, using theory, and engaging end-users. Methods also consist of further additional tasks. Examples of methods for designing the organisation and system-level interventions were limited. Further analysis of design tasks could facilitate the development of detailed guidelines for designing interventions.

Methods and Technologies Branch (MTB)

Cancer.gov

The Methods and Technologies Branch focuses on methods to address epidemiologic data collection, study design and analysis, and to modify technological approaches to better understand cancer susceptibility.

Parametric study of variation in cargo-airplane performance related to progression from current to spanloader designs

NASA Technical Reports Server (NTRS)

Toll, T. A.

1980-01-01

A parametric analysis was made to investigate the relationship between current cargo airplanes and possible future designs that may differ greatly in both size and configuration. The method makes use of empirical scaling laws developed from statistical studies of data from current and advanced airplanes and, in addition, accounts for payload density, effects of span distributed load, and variations in tail area ratio. The method is believed to be particularly useful for exploratory studies of design and technology options for large airplanes. The analysis predicts somewhat more favorable variations of the ratios of payload to gross weight and block fuel to payload as the airplane size is increased than has been generally understood from interpretations of the cube-square law. In terms of these same ratios, large all wing (spanloader) designs show an advantage over wing-fuselage designs.

Evaluating efficiency and statistical power of self-controlled case series and self-controlled risk interval designs in vaccine safety.

PubMed

Li, Rongxia; Stewart, Brock; Weintraub, Eric

2016-01-01

The self-controlled case series (SCCS) and self-controlled risk interval (SCRI) designs have recently become widely used in the field of post-licensure vaccine safety monitoring to detect potential elevated risks of adverse events following vaccinations. The SCRI design can be viewed as a subset of the SCCS method in that a reduced comparison time window is used for the analysis. Compared to the SCCS method, the SCRI design has less statistical power due to fewer events occurring in the shorter control interval. In this study, we derived the asymptotic relative efficiency (ARE) between these two methods to quantify this loss in power in the SCRI design. The equation is formulated as [Formula: see text] (a: control window-length ratio between SCRI and SCCS designs; b: ratio of risk window length and control window length in the SCCS design; and [Formula: see text]: relative risk of exposed window to control window). According to this equation, the relative efficiency declines as the ratio of control-period length between SCRI and SCCS methods decreases, or with an increase in the relative risk [Formula: see text]. We provide an example utilizing data from the Vaccine Safety Datalink (VSD) to study the potential elevated risk of febrile seizure following seasonal influenza vaccine in the 2010-2011 season.

Invisibility problem in acoustics, electromagnetism and heat transfer. Inverse design method

NASA Astrophysics Data System (ADS)

Alekseev, G.; Tokhtina, A.; Soboleva, O.

2017-10-01

Two approaches (direct design and inverse design methods) for solving problems of designing devices providing invisibility of material bodies of detection using different physical fields - electromagnetic, acoustic and static are discussed. The second method is applied for solving problems of designing cloaking devices for the 3D stationary thermal scattering model. Based on this method the design problems under study are reduced to respective control problems. The material parameters (radial and tangential heat conductivities) of the inhomogeneous anisotropic medium filling the thermal cloak and the density of auxiliary heat sources play the role of controls. A unique solvability of direct thermal scattering problem in the Sobolev space is proved and the new estimates of solutions are established. Using these results, the solvability of control problem is proved and the optimality system is derived. Based on analysis of optimality system, the stability estimates of optimal solutions are established and numerical algorithms for solving particular thermal cloaking problem are proposed.

Assessing the reliability of ecotoxicological studies: An overview of current needs and approaches.

PubMed

Moermond, Caroline; Beasley, Amy; Breton, Roger; Junghans, Marion; Laskowski, Ryszard; Solomon, Keith; Zahner, Holly

2017-07-01

In general, reliable studies are well designed and well performed, and enough details on study design and performance are reported to assess the study. For hazard and risk assessment in various legal frameworks, many different types of ecotoxicity studies need to be evaluated for reliability. These studies vary in study design, methodology, quality, and level of detail reported (e.g., reviews, peer-reviewed research papers, or industry-sponsored studies documented under Good Laboratory Practice [GLP] guidelines). Regulators have the responsibility to make sound and verifiable decisions and should evaluate each study for reliability in accordance with scientific principles regardless of whether they were conducted in accordance with GLP and/or standardized methods. Thus, a systematic and transparent approach is needed to evaluate studies for reliability. In this paper, 8 different methods for reliability assessment were compared using a number of attributes: categorical versus numerical scoring methods, use of exclusion and critical criteria, weighting of criteria, whether methods are tested with case studies, domain of applicability, bias toward GLP studies, incorporation of standard guidelines in the evaluation method, number of criteria used, type of criteria considered, and availability of guidance material. Finally, some considerations are given on how to choose a suitable method for assessing reliability of ecotoxicity studies. Integr Environ Assess Manag 2017;13:640-651. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Development of an ultra high performance liquid chromatography method for determining triamcinolone acetonide in hydrogels using the design of experiments/design space strategy in combination with process capability index.

PubMed

Oliva, Alexis; Monzón, Cecilia; Santoveña, Ana; Fariña, José B; Llabrés, Matías

2016-07-01

An ultra high performance liquid chromatography method was developed and validated for the quantitation of triamcinolone acetonide in an injectable ophthalmic hydrogel to determine the contribution of analytical method error in the content uniformity measurement. During the development phase, the design of experiments/design space strategy was used. For this, the free R-program was used as a commercial software alternative, a fast efficient tool for data analysis. The process capability index was used to find the permitted level of variation for each factor and to define the design space. All these aspects were analyzed and discussed under different experimental conditions by the Monte Carlo simulation method. Second, a pre-study validation procedure was performed in accordance with the International Conference on Harmonization guidelines. The validated method was applied for the determination of uniformity of dosage units and the reasons for variability (inhomogeneity and the analytical method error) were analyzed based on the overall uncertainty. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of quality by design concept to develop a dual gradient elution stability-indicating method for cloxacillin forced degradation studies using combined mixture-process variable models.

PubMed

Zhang, Xia; Hu, Changqin

2017-09-08

Penicillins are typical of complex ionic samples which likely contain large number of degradation-related impurities (DRIs) with different polarities and charge properties. It is often a challenge to develop selective and robust high performance liquid chromatography (HPLC) methods for the efficient separation of all DRIs. In this study, an analytical quality by design (AQbD) approach was proposed for stability-indicating method development of cloxacillin. The structures, retention and UV characteristics rules of penicillins and their impurities were summarized and served as useful prior knowledge. Through quality risk assessment and screen design, 3 critical process parameters (CPPs) were defined, including 2 mixture variables (MVs) and 1 process variable (PV). A combined mixture-process variable (MPV) design was conducted to evaluate the 3 CPPs simultaneously and a response surface methodology (RSM) was used to achieve the optimal experiment parameters. A dual gradient elution was performed to change buffer pH, mobile-phase type and strength simultaneously. The design spaces (DSs) was evaluated using Monte Carlo simulation to give their possibility of meeting the specifications of CQAs. A Plackett-Burman design was performed to test the robustness around the working points and to decide the normal operating ranges (NORs). Finally, validation was performed following International Conference on Harmonisation (ICH) guidelines. To our knowledge, this is the first study of using MPV design and dual gradient elution to develop HPLC methods and improve separations for complex ionic samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Design Study for a Free-piston Vuilleumier Cycle Heat Pump

NASA Astrophysics Data System (ADS)

Matsue, Junji; Hoshino, Norimasa; Ikumi, Yonezou; Shirai, Hiroyuki

Conceptual design for a free-piston Vuilleumier cycle heat pump machine was proposed. The machine was designed based upon the numerical results of a dynamic analysis method. The method included the effect of self excitation vibration with dissipation caused by the flow friction of an oscillating working gas flow and solid friction of seals. It was found that the design values of reciprocating masses and spring constants proposed in published papers related to this study were suitable for practical use. The fundamental effects of heat exchanger elements on dynamic behaviors of the machine were clarified. It has been pointed out that some improvements were required for thermodynamic analysis of heat exchangers and working spaces.

Efficient Computing Budget Allocation for Finding Simplest Good Designs

PubMed Central

Jia, Qing-Shan; Zhou, Enlu; Chen, Chun-Hung

2012-01-01

In many applications some designs are easier to implement, require less training data and shorter training time, and consume less storage than the others. Such designs are called simple designs, and are usually preferred over complex ones when they all have good performance. Despite the abundant existing studies on how to find good designs in simulation-based optimization (SBO), there exist few studies on finding simplest good designs. We consider this important problem in this paper, and make the following contributions. First, we provide lower bounds for the probabilities of correctly selecting the m simplest designs with top performance, and selecting the best m such simplest good designs, respectively. Second, we develop two efficient computing budget allocation methods to find m simplest good designs and to find the best m such designs, respectively; and show their asymptotic optimalities. Third, we compare the performance of the two methods with equal allocations over 6 academic examples and a smoke detection problem in wireless sensor networks. We hope that this work brings insight to finding the simplest good designs in general. PMID:23687404

Detecting Low Incidents Effects: The Value of Mixed Methods Research Designs in Low-N Studies

ERIC Educational Resources Information Center

Newman, Isadore; Ridenour, Carolyn S.; Newman, Carole; Smith, Shannon; Brown, Russell C.

2013-01-01

Many important educational situations such as traumatic brain injury among preschoolers, school gun violence, preadolescent eating disorders, and adolescent suicide happen relatively infrequently. In this article, the authors explain why mixed methods research designs offer more meaningful empirical results than do qualitative or quantitative…

An Artificial Intelligence Tutor: A Supplementary Tool for Teaching and Practicing Braille

ERIC Educational Resources Information Center

McCarthy, Tessa; Rosenblum, L. Penny; Johnson, Benny G.; Dittel, Jeffrey; Kearns, Devin M.

2016-01-01

Introduction: This study evaluated the usability and effectiveness of an artificial intelligence Braille Tutor designed to supplement the instruction of students with visual impairments as they learned to write braille contractions. Methods: A mixed-methods design was used, which incorporated a single-subject, adapted alternating treatments design…

Does Implementation Follow Design? A Case Study of a Workplace Health Promotion Program Using the 4-S Program Design and the PIPE Impact Metric Evaluation Models

PubMed Central

Äikäs, Antti Hermanni; Pronk, Nicolaas P.; Hirvensalo, Mirja Hannele; Absetz, Pilvikki

2017-01-01

Objective: The aim of this study was to describe the content of a multiyear market-based workplace health promotion (WHP) program and to evaluate design and implementation processes in a real-world setting. Methods: Data was collected from the databases of the employer and the service provider. It was classified using the 4-S (Size, Scope, Scalability, and Sustainability) and PIPE Impact Metric (Penetration, Implementation) models. Data analysis utilized both qualitative and quantitative methods. Results: Program design covered well the evidence-informed best practices except for clear path toward sustainability, cooperation with occupational health care, and support from middle-management supervisors. The penetration rate among participants was high (99%) and majority (81%) of services were implemented as designed. Conclusion: Study findings indicate that WHP market would benefit the use of evidence-based design principles and tendentious decisions to anticipate a long-term implementation process already during the planning phase. PMID:28665839

Innovative research methods for studying treatments for rare diseases: methodological review.

PubMed

Gagne, Joshua J; Thompson, Lauren; O'Keefe, Kelly; Kesselheim, Aaron S

2014-11-24

To examine methods for generating evidence on health outcomes in patients with rare diseases. Methodological review of existing literature. PubMed, Embase, and Academic Search Premier searched for articles describing innovative approaches to randomized trial design and analysis methods and methods for conducting observational research in patients with rare diseases. We assessed information related to the proposed methods, the specific rare disease being studied, and outcomes from the application of the methods. We summarize methods with respect to their advantages in studying health outcomes in rare diseases and provide examples of their application. We identified 46 articles that proposed or described methods for studying patient health outcomes in rare diseases. Articles covered a wide range of rare diseases and most (72%) were published in 2008 or later. We identified 16 research strategies for studying rare disease. Innovative clinical trial methods minimize sample size requirements (n=4) and maximize the proportion of patients who receive active treatment (n=2), strategies crucial to studying small populations of patients with limited treatment choices. No studies describing unique methods for conducting observational studies in patients with rare diseases were identified. Though numerous studies apply unique clinical trial designs and considerations to assess patient health outcomes in rare diseases, less attention has been paid to innovative methods for studying rare diseases using observational data. © Gagne et al 2014.

Designing a mixed methods study in primary care.

PubMed

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.

Health risk behaviours amongst school adolescents: protocol for a mixed methods study.

PubMed

El Achhab, Youness; El Ammari, Abdelghaffar; El Kazdouh, Hicham; Najdi, Adil; Berraho, Mohamed; Tachfouti, Nabil; Lamri, Driss; El Fakir, Samira; Nejjari, Chakib

2016-11-29

Determining risky behaviours of adolescents provides valuable information for designing appropriate intervention programmes for advancing adolescent's health. However, these behaviours are not fully addressed by researchers in a comprehensive approach. We report the protocol of a mixed methods study designed to investigate the health risk behaviours of Moroccan adolescents with the goal of identifying suitable strategies to address their health concerns. We used a sequential two-phase explanatory mixed method study design. The approach begins with the collection of quantitative data, followed by the collection of qualitative data to explain and enrich the quantitative findings. In the first phase, the global school-based student health survey (GSHS) was administered to 800 students who were between 14 and 19 years of age. The second phase engaged adolescents, parents and teachers in focus groups and assessed education documents to explore the level of coverage of health education in the programme learnt in the middle school. To obtain opinions about strategies to reduce Moroccan adolescents' health risk behaviours, a nominal group technique will be used. The findings of this mixed methods sequential explanatory study provide insights into the risk behaviours that need to be considered if intervention programmes and preventive strategies are to be designed to promote adolescent's health in the Moroccan school.

Design sensitivity analysis of rotorcraft airframe structures for vibration reduction

NASA Technical Reports Server (NTRS)

Murthy, T. Sreekanta

1987-01-01

Optimization of rotorcraft structures for vibration reduction was studied. The objective of this study is to develop practical computational procedures for structural optimization of airframes subject to steady-state vibration response constraints. One of the key elements of any such computational procedure is design sensitivity analysis. A method for design sensitivity analysis of airframes under vibration response constraints is presented. The mathematical formulation of the method and its implementation as a new solution sequence in MSC/NASTRAN are described. The results of the application of the method to a simple finite element stick model of the AH-1G helicopter airframe are presented and discussed. Selection of design variables that are most likely to bring about changes in the response at specified locations in the airframe is based on consideration of forced response strain energy. Sensitivity coefficients are determined for the selected design variable set. Constraints on the natural frequencies are also included in addition to the constraints on the steady-state response. Sensitivity coefficients for these constraints are determined. Results of the analysis and insights gained in applying the method to the airframe model are discussed. The general nature of future work to be conducted is described.

Grid Based Technologies for in silico Screening and Drug Design.

PubMed

Potemkin, Vladimir; Grishina, Maria

2018-03-08

Various techniques for rational drug design are presented in the paper. The methods are based on a substitution of antipharmacophore atoms of the molecules of training dataset by new atoms and/or group of atoms increasing the atomic bioactivity increments obtained at a SAR study. Furthermore, a design methodology based on the genetic algorithm DesPot for discrete optimization and generation of new drug candidate structures is described. Additionally, wide spectra of SAR approaches (3D/4D QSAR interior and exterior-based methods - BiS, CiS, ConGO, CoMIn, high-quality docking method - ReDock) using MERA force field and/or AlteQ quantum chemical method for correct prognosis of bioactivity and bioactive probability is described. The design methods are implemented now at www.chemosophia.com web-site for online computational services. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Designing A Mixed Methods Study In Primary Care

PubMed Central

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

Improvement of a stability-indicating method by Quality-by-Design versus Quality-by-Testing: a case of a learning process.

PubMed

Hubert, C; Lebrun, P; Houari, S; Ziemons, E; Rozet, E; Hubert, Ph

2014-01-01

The understanding of the method is a major concern when developing a stability-indicating method and even more so when dealing with impurity assays from complex matrices. In the presented case study, a Quality-by-Design approach was applied in order to optimize a routinely used method. An analytical issue occurring at the last stage of a long-term stability study involving unexpected impurities perturbing the monitoring of characterized impurities needed to be resolved. A compliant Quality-by-Design (QbD) methodology based on a Design of Experiments (DoE) approach was evaluated within the framework of a Liquid Chromatography (LC) method. This approach allows the investigation of Critical Process Parameters (CPPs), which have an impact on Critical Quality Attributes (CQAs) and, consequently, on LC selectivity. Using polynomial regression response modeling as well as Monte Carlo simulations for error propagation, Design Space (DS) was computed in order to determine robust working conditions for the developed stability-indicating method. This QbD compliant development was conducted in two phases allowing the use of the Design Space knowledge acquired during the first phase to define the experimental domain of the second phase, which constitutes a learning process. The selected working condition was then fully validated using accuracy profiles based on statistical tolerance intervals in order to evaluate the reliability of the results generated by this LC/ESI-MS stability-indicating method. A comparison was made between the traditional Quality-by-Testing (QbT) approach and the QbD strategy, highlighting the benefit of this QbD strategy in the case of an unexpected impurities issue. On this basis, the advantages of a systematic use of the QbD methodology were discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Statistical issues in the design, conduct and analysis of two large safety studies.

PubMed

Gaffney, Michael

2016-10-01

The emergence, post approval, of serious medical events, which may be associated with the use of a particular drug or class of drugs, is an important public health and regulatory issue. The best method to address this issue is through a large, rigorously designed safety study. Therefore, it is important to elucidate the statistical issues involved in these large safety studies. Two such studies are PRECISION and EAGLES. PRECISION is the primary focus of this article. PRECISION is a non-inferiority design with a clinically relevant non-inferiority margin. Statistical issues in the design, conduct and analysis of PRECISION are discussed. Quantitative and clinical aspects of the selection of the composite primary endpoint, the determination and role of the non-inferiority margin in a large safety study and the intent-to-treat and modified intent-to-treat analyses in a non-inferiority safety study are shown. Protocol changes that were necessary during the conduct of PRECISION are discussed from a statistical perspective. Issues regarding the complex analysis and interpretation of the results of PRECISION are outlined. EAGLES is presented as a large, rigorously designed safety study when a non-inferiority margin was not able to be determined by a strong clinical/scientific method. In general, when a non-inferiority margin is not able to be determined, the width of the 95% confidence interval is a way to size the study and to assess the cost-benefit of relative trial size. A non-inferiority margin, when able to be determined by a strong scientific method, should be included in a large safety study. Although these studies could not be called "pragmatic," they are examples of best real-world designs to address safety and regulatory concerns. © The Author(s) 2016.

Negotiating a Systems Development Method

NASA Astrophysics Data System (ADS)

Karlsson, Fredrik; Hedström, Karin

Systems development methods (or methods) are often applied in tailored version to fit the actual situation. Method tailoring is in most the existing literature viewed as either (a) a highly rational process with the method engineer as the driver where the project members are passive information providers or (b) an unstructured process where the systems developer makes individual choices, a selection process without any driver. The purpose of this chapter is to illustrate that important design decisions during method tailoring are made by project members through negotiation. The study has been carried out using the perspective of actor-network theory. Our narratives depict method tailoring as more complex than (a) and (b) show the driver role rotates between the project members, and design decisions are based on influences from several project members. However, these design decisions are not consensus decisions.

Effects of Drama Method on Speaking Anxieties of Pre-Service Teachers and Their Opinions about the Method

ERIC Educational Resources Information Center

Sevim, Oguzhan

2014-01-01

The aim of this study is to determine the effects of the drama method on speaking anxieties of pre-service teachers and their opinions about the method. In the study, mixed method including experimental design, quantitative, and basic qualitative research was used. The study was carried out with 77 first grade students from day-time and evening…

Developing a Conceptual Framework for Participatory Design of Psychosocial and Physical Learning Environments

ERIC Educational Resources Information Center

Mäkelä, Tiina; Helfenstein, Sacha

2016-01-01

The present study shows how the mixed-methods approach can be used in capturing and organising learning environment (LE) characteristics for the participatory design of psychosocial and physical LEs involving learners. Theoretical constructs were tested and further elaborated on in the analysis of two similar educational design research studies:…

The Design of Time-Series Comparisons under Resource Constraints.

ERIC Educational Resources Information Center

Willemain, Thomas R.; Hartunian, Nelson S.

1982-01-01

Two methods for dividing an interrupted time-series study between baseline and experimental phases when study resources are limited are compared. In fixed designs, the baseline duration is predetermined. In flexible designs the baseline duration is contingent on remaining resources and the match of results to prior expectations of the evaluator.…

Teachers as Co-Designers of Technology-Rich Learning Activities for Early Literacy

ERIC Educational Resources Information Center

Cviko, Amina; McKenney, Susan; Voogt, Joke

2015-01-01

Although kindergarten teachers often struggle with implementing technology, they are rarely involved in co-designing technology-rich learning activities. This study involved teachers in the co-design of technology-rich learning activities and sought to explore implementation and pupil learning outcomes. A case-study method was used to investigate:…

Design of two-channel filter bank using nature inspired optimization based fractional derivative constraints.

PubMed

Kuldeep, B; Singh, V K; Kumar, A; Singh, G K

2015-01-01

In this article, a novel approach for 2-channel linear phase quadrature mirror filter (QMF) bank design based on a hybrid of gradient based optimization and optimization of fractional derivative constraints is introduced. For the purpose of this work, recently proposed nature inspired optimization techniques such as cuckoo search (CS), modified cuckoo search (MCS) and wind driven optimization (WDO) are explored for the design of QMF bank. 2-Channel QMF is also designed with particle swarm optimization (PSO) and artificial bee colony (ABC) nature inspired optimization techniques. The design problem is formulated in frequency domain as sum of L2 norm of error in passband, stopband and transition band at quadrature frequency. The contribution of this work is the novel hybrid combination of gradient based optimization (Lagrange multiplier method) and nature inspired optimization (CS, MCS, WDO, PSO and ABC) and its usage for optimizing the design problem. Performance of the proposed method is evaluated by passband error (ϕp), stopband error (ϕs), transition band error (ϕt), peak reconstruction error (PRE), stopband attenuation (As) and computational time. The design examples illustrate the ingenuity of the proposed method. Results are also compared with the other existing algorithms, and it was found that the proposed method gives best result in terms of peak reconstruction error and transition band error while it is comparable in terms of passband and stopband error. Results show that the proposed method is successful for both lower and higher order 2-channel QMF bank design. A comparative study of various nature inspired optimization techniques is also presented, and the study singles out CS as a best QMF optimization technique. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Aerodynamic Shape Optimization of Supersonic Aircraft Configurations via an Adjoint Formulation on Parallel Computers

NASA Technical Reports Server (NTRS)

Reuther, James; Alonso, Juan Jose; Rimlinger, Mark J.; Jameson, Antony

1996-01-01

This work describes the application of a control theory-based aerodynamic shape optimization method to the problem of supersonic aircraft design. The design process is greatly accelerated through the use of both control theory and a parallel implementation on distributed memory computers. Control theory is employed to derive the adjoint differential equations whose solution allows for the evaluation of design gradient information at a fraction of the computational cost required by previous design methods (13, 12, 44, 38). The resulting problem is then implemented on parallel distributed memory architectures using a domain decomposition approach, an optimized communication schedule, and the MPI (Message Passing Interface) Standard for portability and efficiency. The final result achieves very rapid aerodynamic design based on higher order computational fluid dynamics methods (CFD). In our earlier studies, the serial implementation of this design method (19, 20, 21, 23, 39, 25, 40, 41, 42, 43, 9) was shown to be effective for the optimization of airfoils, wings, wing-bodies, and complex aircraft configurations using both the potential equation and the Euler equations (39, 25). In our most recent paper, the Euler method was extended to treat complete aircraft configurations via a new multiblock implementation. Furthermore, during the same conference, we also presented preliminary results demonstrating that the basic methodology could be ported to distributed memory parallel computing architectures [241. In this paper, our concem will be to demonstrate that the combined power of these new technologies can be used routinely in an industrial design environment by applying it to the case study of the design of typical supersonic transport configurations. A particular difficulty of this test case is posed by the propulsion/airframe integration.

New displacement-based methods for optimal truss topology design

NASA Technical Reports Server (NTRS)

Bendsoe, Martin P.; Ben-Tal, Aharon; Haftka, Raphael T.

1991-01-01

Two alternate methods for maximum stiffness truss topology design are presented. The ground structure approach is used, and the problem is formulated in terms of displacements and bar areas. This large, nonconvex optimization problem can be solved by a simultaneous analysis and design approach. Alternatively, an equivalent, unconstrained, and convex problem in the displacements only can be formulated, and this problem can be solved by a nonsmooth, steepest descent algorithm. In both methods, the explicit solving of the equilibrium equations and the assembly of the global stiffness matrix are circumvented. A large number of examples have been studied, showing the attractive features of topology design as well as exposing interesting features of optimal topologies.

Methodology on Investigating the Influences of Automated Material Handling System in Automotive Assembly Process

NASA Astrophysics Data System (ADS)

Saffar, Seha; Azni Jafar, Fairul; Jamaludin, Zamberi

2016-02-01

A case study was selected as a method to collect data in actual industry situation. The study aimed to assess the influences of automated material handling system in automotive industry by proposing a new design of integration system through simulation, and analyze the significant effect and influence of the system. The method approach tool will be CAD Software (Delmia & Quest). The process of preliminary data gathering in phase 1 will collect all data related from actual industry situation. It is expected to produce a guideline and limitation in designing a new integration system later. In phase 2, an idea or concept of design will be done by using 10 principles of design consideration for manufacturing. A full factorial design will be used as design of experiment in order to analyze the performance measured of the integration system with the current system in case study. From the result of the experiment, an ANOVA analysis will be done to study the performance measured. Thus, it is expected that influences can be seen from the improvement made in the system.

Quantitative Imaging Biomarkers: A Review of Statistical Methods for Technical Performance Assessment

PubMed Central

2017-01-01

Technological developments and greater rigor in the quantitative measurement of biological features in medical images have given rise to an increased interest in using quantitative imaging biomarkers (QIBs) to measure changes in these features. Critical to the performance of a QIB in preclinical or clinical settings are three primary metrology areas of interest: measurement linearity and bias, repeatability, and the ability to consistently reproduce equivalent results when conditions change, as would be expected in any clinical trial. Unfortunately, performance studies to date differ greatly in designs, analysis method and metrics used to assess a QIB for clinical use. It is therefore, difficult or not possible to integrate results from different studies or to use reported results to design studies. The Radiological Society of North America (RSNA) and the Quantitative Imaging Biomarker Alliance (QIBA) with technical, radiological and statistical experts developed a set of technical performance analysis methods, metrics and study designs that provide terminology, metrics and methods consistent with widely accepted metrological standards. This document provides a consistent framework for the conduct and evaluation of QIB performance studies so that results from multiple studies can be compared, contrasted or combined. PMID:24919831

Minimizing student’s faults in determining the design of experiment through inquiry-based learning

NASA Astrophysics Data System (ADS)

Nilakusmawati, D. P. E.; Susilawati, M.

2017-10-01

The purpose of this study were to describe the used of inquiry method in an effort to minimize student’s fault in designing an experiment and to determine the effectiveness of the implementation of the inquiry method in minimizing student’s faults in designing experiments on subjects experimental design. This type of research is action research participants, with a model of action research design. The data source were students of the fifth semester who took a subject of experimental design at Mathematics Department, Faculty of Mathematics and Natural Sciences, Udayana University. Data was collected through tests, interviews, and observations. The hypothesis was tested by t-test. The result showed that the implementation of inquiry methods to minimize of students fault in designing experiments, analyzing experimental data, and interpret them in cycle 1 students can reduce fault by an average of 10.5%. While implementation in Cycle 2, students managed to reduce fault by an average of 8.78%. Based on t-test results can be concluded that the inquiry method effectively used to minimize of student’s fault in designing experiments, analyzing experimental data, and interpreting them. The nature of the teaching materials on subject of Experimental Design that demand the ability of students to think in a systematic, logical, and critical in analyzing the data and interpret the test cases makes the implementation of this inquiry become the proper method. In addition, utilization learning tool, in this case the teaching materials and the students worksheet is one of the factors that makes this inquiry method effectively minimizes of student’s fault when designing experiments.

Linear Matrix Inequality Method for a Quadratic Performance Index Minimization Problem with a class of Bilinear Matrix Inequality Conditions

NASA Astrophysics Data System (ADS)

Tanemura, M.; Chida, Y.

2016-09-01

There are a lot of design problems of control system which are expressed as a performance index minimization under BMI conditions. However, a minimization problem expressed as LMIs can be easily solved because of the convex property of LMIs. Therefore, many researchers have been studying transforming a variety of control design problems into convex minimization problems expressed as LMIs. This paper proposes an LMI method for a quadratic performance index minimization problem with a class of BMI conditions. The minimization problem treated in this paper includes design problems of state-feedback gain for switched system and so on. The effectiveness of the proposed method is verified through a state-feedback gain design for switched systems and a numerical simulation using the designed feedback gains.

A method for the design of transonic flexible wings

NASA Technical Reports Server (NTRS)

Smith, Leigh Ann; Campbell, Richard L.

1990-01-01

Methodology was developed for designing airfoils and wings at transonic speeds which includes a technique that can account for static aeroelastic deflections. This procedure is capable of designing either supercritical or more conventional airfoil sections. Methods for including viscous effects are also illustrated and are shown to give accurate results. The methodology developed is an interactive system containing three major parts. A design module was developed which modifies airfoil sections to achieve a desired pressure distribution. This design module works in conjunction with an aerodynamic analysis module, which for this study is a small perturbation transonic flow code. Additionally, an aeroelastic module is included which determines the wing deformation due to the calculated aerodynamic loads. Because of the modular nature of the method, it can be easily coupled with any aerodynamic analysis code.

Methodology issues in implementation science.

PubMed

Newhouse, Robin; Bobay, Kathleen; Dykes, Patricia C; Stevens, Kathleen R; Titler, Marita

2013-04-01

Putting evidence into practice at the point of care delivery requires an understanding of implementation strategies that work, in what context and how. To identify methodological issues in implementation science using 4 studies as cases and make recommendations for further methods development. Four cases are presented and methodological issues identified. For each issue raised, evidence on the state of the science is described. Issues in implementation science identified include diverse conceptual frameworks, potential weaknesses in pragmatic study designs, and the paucity of standard concepts and measurement. Recommendations to advance methods in implementation include developing a core set of implementation concepts and metrics, generating standards for implementation methods including pragmatic trials, mixed methods designs, complex interventions and measurement, and endorsing reporting standards for implementation studies.

Quantifying electrical impacts on redundant wire insertion in 7nm unidirectional designs

NASA Astrophysics Data System (ADS)

Mohyeldin, Ahmed; Schroeder, Uwe Paul; Srinivasan, Ramya; Narisetty, Haritez; Malik, Shobhit; Madhavan, Sriram

2017-04-01

In nano-meter scale Integrated Circuits, via fails due to random defects is a well-known yield detractor, and via redundancy insertion is a common method to help enhance semiconductors yield. For the case of Self Aligned Double Patterning (SADP), which might require unidirectional design layers as in the case of some advanced technology nodes, the conventional methods of inserting redundant vias don't work any longer. This is because adding redundant vias conventionally requires adding metal shapes in the non-preferred direction, which will violate the SADP design constraints in that case. Therefore, such metal layers fabricated using unidirectional SADP require an alternative method for providing the needed redundancy. This paper proposes a post-layout Design for Manufacturability (DFM) redundancy insertion method tailored for the design requirements introduced by unidirectional metal layers. The proposed method adds redundant wires in the preferred direction - after searching for nearby vacant routing tracks - in order to provide redundant paths for electrical signals. This method opportunistically adds robustness against failures due to silicon defects without impacting area or incurring new design rule violations. Implementation details of this redundancy insertion method will be explained in this paper. One known challenge with similar DFM layout fixing methods is the possible introduction of undesired electrical impact, causing other unintentional failures in design functionality. In this paper, a study is presented to quantify the electrical impacts of such redundancy insertion scheme and to examine if that electrical impact can be tolerated. The paper will show results to evaluate DFM insertion rates and corresponding electrical impact for a given design utilization and maximum inserted wire length. Parasitic extraction and static timing analysis results will be presented. A typical digital design implemented using GLOBALFOUNDRIES 7nm technology is used for demonstration. The provided results can help evaluate such extensive DFM insertion method from an electrical standpoint. Furthermore, the results could provide guidance on how to implement the proposed method of adding electrical redundancy such that intolerable electrical impacts could be avoided.

Carotid Intima-Media Thickness Studies: Study Design and Data Analysis

PubMed Central

Bots, Michiel L.

2013-01-01

Background Carotid intima-media thickness (CIMT) measurements have been widely used as primary endpoint in studies into the effects of new interventions as alternative for cardiovascular morbidity and mortality. There are no accepted standards on the use of CIMT measurements in intervention studies and choices in the design and analysis of a CIMT study are generally based on experience and expert opinion. In the present review, we provide an overview of the current evidence on several aspects in the design and analysis of a CIMT study on the early effects of new interventions. Summary of Issues A balanced evaluation of the carotid segments, carotid walls, and image view to be used as CIMT study endpoint; the reading method (manual or semi-automated and continuously or in batch) to be employed, the required sample size, and the frequency of ultrasound examinations is provided. We also discuss the preferred methods to analyse longitudinal CIMT data and address the possible impact of, and methods to deal with missing and biologically implausible CIMT values. Conclusions Linear mixed effects models are the preferred way to analyse CIMT data and do appropriately handle missing and biologically implausible CIMT values. Furthermore, we recommend to use extensive CIMT designs that measure CIMT at regular points during the multiple carotid sites as such approach is likely to increase the success rates of CIMT intervention studies designed to evaluate the effects of new interventions on atherosclerotic burden. PMID:24324938

Critique of a practice-based pilot study in chiropractic practices in Western Australia.

PubMed

Amorin-Woods, Lyndon G; Parkin-Smith, Gregory F; Nedkoff, Lee; Fisher, Colleen

2016-01-01

Practice-based data collection can offer insight into the nature of chiropractic practice and contribute to resolving the conundrum of the chiropractic profession's role in contemporary healthcare, subsequently informing care service policy. However, there is little formal data available about chiropractic practice to inform decision-makers about the nature and role of chiropractic within the context of a modern multidisciplinary healthcare context in Australia, particularly at a local and regional level. This was a mixed-methods data transformation model (qualitative to quantitative) pilot study the purpose of which was to provide a critique of the research design and collect data from a selected sample of chiropractic practices in Western Australia, with a view to offer recommendations related to the design, feasibility and implementation of a future confirmatory study. A narrative critique of the research methods of this pilot study is offered in this paper covering: (a) practice and patient recruitment, (b) enrollment of patients, (c) data collection methods, (d) acceptability of the study methods, (e) sample size calculations, and (f) design critique. The result of this critique provides a sensible sample size estimate and recommendations as to the design and implementation of a future confirmatory study. Furthermore, we believe that a confirmatory study is not only feasible, but indeed necessary, with a view to offer meaningful insight into chiropractic practice in Western Australia. ACTRN12616000434493 Australian New Zealand Clinical Trials Registry (ANZCTR). Registered 5 April 2016. First participant enrolled 01 July 2014, retrospectively registered.

Assessment of watershed regionalization for the land use change parameterization

NASA Astrophysics Data System (ADS)

Randusová, Beata; Kohnová, Silvia; Studvová, Zuzana; Marková, Romana; Nosko, Radovan

2016-04-01

The estimation of design discharges and water levels of extreme floods is one of the most important parts of the design process for a large number of engineering projects and studies. Floods and other natural hazards initiated by climate, soil, and land use changes are highly important in the 21st century. Flood risks and design flood estimation is particularly challenging. Methods of design flood estimation can be applied either locally or regionally. To obtain the design values in such cases where no recorded data exist, many countries have adopted procedures that fit the local conditions and requirements. One of these methods is the Soil Conservation Service - Curve number (SCS-CN) method which is often used in design flood estimation for ungauged sites. The SCS-CN method is an empirical rainfall-runoff model developed by the USDA Natural Resources Conservation Service (formerly called the Soil Conservation Service or SCS). The runoff curve number (CN) is based on the hydrological soil characteristics, land use, land management and antecedent saturation conditions of soil. This study is focused on development of the SCS-CN methodology for the changing land use conditions in Slovak basins (with the pilot site of the Myjava catchment), which regionalize actual state of land use data and actual rainfall and discharge measurements of the selected river basins. In this study the state of the water erosion and sediment transport along with a subsequent proposal of erosion control measures was analyzed as well. The regionalized SCS-CN method was subsequently used for assessing the effectiveness of this control measure to reduce runoff from the selected basin. For the determination of the sediment transport from the control measure to the Myjava basin, the SDR (Sediment Delivery Ratio) model was used.

The Development, Description and Appraisal of an Emergent Multimethod Research Design to Study Workforce Changes in Integrated Care Interventions.

PubMed

Busetto, Loraine; Luijkx, Katrien; Calciolari, Stefano; González-Ortiz, Laura G; Vrijhoef, Hubertus J M

2017-03-08

In this paper, we provide a detailed and explicit description of the processes and decisions underlying and shaping the emergent multimethod research design of our study on workforce changes in integrated chronic care. The study was originally planned as mixed method research consisting of a preliminary literature review and quantitative check of these findings via a Delphi panel. However, when the findings of the literature review were not appropriate for quantitative confirmation, we chose to continue our qualitative exploration of the topic via qualitative questionnaires and secondary analysis of two best practice case reports. The resulting research design is schematically described as an emergent and interactive multimethod design with multiphase combination timing. In doing so, we provide other researchers with a set of theory- and experience-based options to develop their own multimethod research and provide an example for more detailed and structured reporting of emergent designs. We argue that the terminology developed for the description of mixed methods designs should also be used for multimethod designs such as the one presented here.

Small Independent Action Force (SIAF), Vegetation Classification Study

DTIC Science & Technology

1976-03-01

CONTENTS I. INTRODUCTION 8 II. BACKGBCUND and PORPOSE 10 III. METHOD 16 A. EXPERIMENTAL DESIGN 16 B. SUBJECTS .’ 17 C. APPARATUS 17 D. STIMULUS...reliability of subjects will be obtained. 15 III. METHOD A. EXPERIMENTAL DESIGN . The experiment involved a continous stream of stimuli. Phase 1 stimuli...the attribute to be scaled. The subjecr must designate one of the pair as greater. No equality judgments are permitted. In order to obtain data from

Precision, time, and cost: a comparison of three sampling designs in an emergency setting.

PubMed

Deitchler, Megan; Deconinck, Hedwig; Bergeron, Gilles

2008-05-02

The conventional method to collect data on the health, nutrition, and food security status of a population affected by an emergency is a 30 x 30 cluster survey. This sampling method can be time and resource intensive and, accordingly, may not be the most appropriate one when data are needed rapidly for decision making. In this study, we compare the precision, time and cost of the 30 x 30 cluster survey with two alternative sampling designs: a 33 x 6 cluster design (33 clusters, 6 observations per cluster) and a 67 x 3 cluster design (67 clusters, 3 observations per cluster). Data for each sampling design were collected concurrently in West Darfur, Sudan in September-October 2005 in an emergency setting. Results of the study show the 30 x 30 design to provide more precise results (i.e. narrower 95% confidence intervals) than the 33 x 6 and 67 x 3 design for most child-level indicators. Exceptions are indicators of immunization and vitamin A capsule supplementation coverage which show a high intra-cluster correlation. Although the 33 x 6 and 67 x 3 designs provide wider confidence intervals than the 30 x 30 design for child anthropometric indicators, the 33 x 6 and 67 x 3 designs provide the opportunity to conduct a LQAS hypothesis test to detect whether or not a critical threshold of global acute malnutrition prevalence has been exceeded, whereas the 30 x 30 design does not. For the household-level indicators tested in this study, the 67 x 3 design provides the most precise results. However, our results show that neither the 33 x 6 nor the 67 x 3 design are appropriate for assessing indicators of mortality. In this field application, data collection for the 33 x 6 and 67 x 3 designs required substantially less time and cost than that required for the 30 x 30 design. The findings of this study suggest the 33 x 6 and 67 x 3 designs can provide useful time- and resource-saving alternatives to the 30 x 30 method of data collection in emergency settings.

Precision, time, and cost: a comparison of three sampling designs in an emergency setting

PubMed Central

Deitchler, Megan; Deconinck, Hedwig; Bergeron, Gilles

2008-01-01

The conventional method to collect data on the health, nutrition, and food security status of a population affected by an emergency is a 30 × 30 cluster survey. This sampling method can be time and resource intensive and, accordingly, may not be the most appropriate one when data are needed rapidly for decision making. In this study, we compare the precision, time and cost of the 30 × 30 cluster survey with two alternative sampling designs: a 33 × 6 cluster design (33 clusters, 6 observations per cluster) and a 67 × 3 cluster design (67 clusters, 3 observations per cluster). Data for each sampling design were collected concurrently in West Darfur, Sudan in September-October 2005 in an emergency setting. Results of the study show the 30 × 30 design to provide more precise results (i.e. narrower 95% confidence intervals) than the 33 × 6 and 67 × 3 design for most child-level indicators. Exceptions are indicators of immunization and vitamin A capsule supplementation coverage which show a high intra-cluster correlation. Although the 33 × 6 and 67 × 3 designs provide wider confidence intervals than the 30 × 30 design for child anthropometric indicators, the 33 × 6 and 67 × 3 designs provide the opportunity to conduct a LQAS hypothesis test to detect whether or not a critical threshold of global acute malnutrition prevalence has been exceeded, whereas the 30 × 30 design does not. For the household-level indicators tested in this study, the 67 × 3 design provides the most precise results. However, our results show that neither the 33 × 6 nor the 67 × 3 design are appropriate for assessing indicators of mortality. In this field application, data collection for the 33 × 6 and 67 × 3 designs required substantially less time and cost than that required for the 30 × 30 design. The findings of this study suggest the 33 × 6 and 67 × 3 designs can provide useful time- and resource-saving alternatives to the 30 × 30 method of data collection in emergency settings. PMID:18454866

Alcohol Warning Label Awareness and Attention: A Multi-method Study.

PubMed

Pham, Cuong; Rundle-Thiele, Sharyn; Parkinson, Joy; Li, Shanshi

2018-01-01

Evaluation of alcohol warning labels requires careful consideration ensuring that research captures more than awareness given that labels may not be prominent enough to attract attention. This study investigates attention of current in market alcohol warning labels and examines whether attention can be enhanced through theoretically informed design. Attention scores obtained through self-report methods are compared to objective measures (eye-tracking). A multi-method experimental design was used delivering four conditions, namely control, colour, size and colour and size. The first study (n = 559) involved a self-report survey to measure attention. The second study (n = 87) utilized eye-tracking to measure fixation count and duration and time to first fixation. Analysis of Variance (ANOVA) was utilized. Eye-tracking identified that 60% of participants looked at the current in market alcohol warning label while 81% looked at the optimized design (larger and red). In line with observed attention self-reported attention increased for the optimized design. The current study casts doubt on dominant practices (largely self-report), which have been used to evaluate alcohol warning labels. Awareness cannot be used to assess warning label effectiveness in isolation in cases where attention does not occur 100% of the time. Mixed methods permit objective data collection methodologies to be triangulated with surveys to assess warning label effectiveness. Attention should be incorporated as a measure in warning label effectiveness evaluations. Colour and size changes to the existing Australian warning labels aided by theoretically informed design increased attention. © The Author 2017. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Method for the Study of Category III Airborne Procedure Reliability

DOT National Transportation Integrated Search

1973-03-01

A method for the study of Category 3 airborne-procedure reliability is presented. The method, based on PERT concepts, is considered to have utility at the outset of a procedure-design cycle and during the early accumulation of actual performance data...

Analytical Methods for a Learning Health System: 2. Design of Observational Studies

PubMed Central

Stoto, Michael; Oakes, Michael; Stuart, Elizabeth; Priest, Elisa L.; Savitz, Lucy

2017-01-01

The second paper in a series on how learning health systems can use routinely collected electronic health data (EHD) to advance knowledge and support continuous learning, this review summarizes study design approaches, including choosing appropriate data sources, and methods for design and analysis of natural and quasi-experiments. The primary strength of study design approaches described in this section is that they study the impact of a deliberate intervention in real-world settings, which is critical for external validity. These evaluation designs address estimating the counterfactual – what would have happened if the intervention had not been implemented. At the individual level, epidemiologic designs focus on identifying situations in which bias is minimized. Natural and quasi-experiments focus on situations where the change in assignment breaks the usual links that could lead to confounding, reverse causation, and so forth. And because these observational studies typically use data gathered for patient management or administrative purposes, the possibility of observation bias is minimized. The disadvantages are that one cannot necessarily attribute the effect to the intervention (as opposed to other things that might have changed), and the results do not indicate what about the intervention made a difference. Because they cannot rely on randomization to establish causality, program evaluation methods demand a more careful consideration of the “theory” of the intervention and how it is expected to play out. A logic model describing this theory can help to design appropriate comparisons, account for all influential variables in a model, and help to ensure that evaluation studies focus on the critical intermediate and long-term outcomes as well as possible confounders. PMID:29881745

Current State of Agile User-Centered Design: A Survey

NASA Astrophysics Data System (ADS)

Hussain, Zahid; Slany, Wolfgang; Holzinger, Andreas

Agile software development methods are quite popular nowadays and are being adopted at an increasing rate in the industry every year. However, these methods are still lacking usability awareness in their development lifecycle, and the integration of usability/User-Centered Design (UCD) into agile methods is not adequately addressed. This paper presents the preliminary results of a recently conducted online survey regarding the current state of the integration of agile methods and usability/UCD. A world wide response of 92 practitioners was received. The results show that the majority of practitioners perceive that the integration of agile methods with usability/UCD has added value to their adopted processes and to their teams; has resulted in the improvement of usability and quality of the product developed; and has increased the satisfaction of the end-users of the product developed. The top most used HCI techniques are low-fidelity prototyping, conceptual designs, observational studies of users, usability expert evaluations, field studies, personas, rapid iterative testing, and laboratory usability testing.

Field techniques and methods of data collection used in studies of wood storks of the Birdsville Colony and swamps of the Savannah River Plant

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

Coulter, M.C.; Bryan, A.L. Jr.

1988-10-01

The United States population of Wood Storks (Mycteria americana) has been declining over the last 50 years, although there has been disagreement as to the magnitude of the decrease. In 1984, the US Fish and Wildlife Service listed the US breeding population as endangered. In that year the University of Georgia's Savannah River Ecology Laboratory began an extensive research program on the breeding biology and foraging ecology of Wood Storks of the Birdsville colony in Millen, Jenkins county, east-central Georgia, USA. The SREL Wood Stork program was designed to evaluate the importance of foraging habitat on the Savannah River Plantmore » to storks, and to design and develop management plans for artificial foraging ponds at the National Audubon Society's Silver Bluff Plantation Sanctuary. It was necessary to develop an understanding of the general foraging ecology of the birds, and to understand their forage needs during the breeding season. We have summarized the methods that we developed during this program as an aid to researchers studying storks or other wading birds. Although the methods described here were designed to answer questions important to our program, we hope that they are general enough to be helpful to others. Some of the methods were designed in 1983, during a preliminary part of the study. All the methods have evolved during the program, improving from our experience. Many people have been involved in the study and all have contributed to the methods and their improvement.« less

Supporting BPMN choreography with system integration artefacts for enterprise process collaboration

NASA Astrophysics Data System (ADS)

Nie, Hongchao; Lu, Xudong; Duan, Huilong

2014-07-01

Business Process Model and Notation (BPMN) choreography modelling depicts externally visible message exchanges between collaborating processes of enterprise information systems. Implementation of choreography relies on designing system integration solutions to realise message exchanges between independently developed systems. Enterprise integration patterns (EIPs) are widely accepted artefacts to design integration solutions. If the choreography model represents coordination requirements between processes with behaviour mismatches, the integration designer needs to analyse the routing requirements and address these requirements by manually designing EIP message routers. As collaboration scales and complexity increases, manual design becomes inefficient. Thus, the research problem of this paper is to explore a method to automatically identify routing requirements from BPMN choreography model and to accordingly design routing in the integration solution. To achieve this goal, recurring behaviour mismatch scenarios are analysed as patterns, and corresponding solutions are proposed as EIP routers. Using this method, a choreography model can be analysed by computer to identify occurrences of mismatch patterns, leading to corresponding router selection. A case study demonstrates that the proposed method enables computer-assisted integration design to implement choreography. A further experiment reveals that the method is effective to improve the design quality and reduce time cost.

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

PubMed

Yu, Qingzhao; Zhu, Lin; Zhu, Han

2017-11-01

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

Multidisciplinary design of a rocket-based combined cycle SSTO launch vehicle using Taguchi methods

NASA Technical Reports Server (NTRS)

Olds, John R.; Walberg, Gerald D.

1993-01-01

Results are presented from the optimization process of a winged-cone configuration SSTO launch vehicle that employs a rocket-based ejector/ramjet/scramjet/rocket operational mode variable-cycle engine. The Taguchi multidisciplinary parametric-design method was used to evaluate the effects of simultaneously changing a total of eight design variables, rather than changing them one at a time as in conventional tradeoff studies. A combination of design variables was in this way identified which yields very attractive vehicle dry and gross weights.

Reply to “Ranking filter methods for concentrating pathogens in lake water”

USGS Publications Warehouse

Bushon, Rebecca N.; Francy, Donna S.; Gallardo, Vicente J.; Lindquist, H.D. Alan; Villegas, Eric N.; Ware, Michael W.

2013-01-01

Accurately comparing filtration methods is indeed difficult. Our method (1) and the method described by Borchardt et al. for determining recoveries are both acceptable approaches; however, each is designed to achieve a different research goal. Our study was designed to compare recoveries of multiple microorganisms in surface-water samples. Because, in practice, water-matrix effects come into play throughout filtration, concentration, and detection processes, we felt it important to incorporate those effects into the recovery results.

Breaking from binaries - using a sequential mixed methods design.

PubMed

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.

Understanding resilience in same-sex parented families: the work, love, play study

PubMed Central

2010-01-01

Background While families headed by same-sex couples have achieved greater public visibility in recent years, there are still many challenges for these families in dealing with legal and community contexts that are not supportive of same-sex relationships. The Work, Love, Play study is a large longitudinal study of same-sex parents. It aims to investigate many facets of family life among this sample and examine how they change over time. The study focuses specifically on two key areas missing from the current literature: factors supporting resilience in same-sex parented families; and health and wellbeing outcomes for same-sex couples who undergo separation, including the negotiation of shared parenting arrangements post-separation. The current paper aims to provide a comprehensive overview of the design and methods of this longitudinal study and discuss its significance. Methods/Design The Work, Love, Play study is a mixed design, three wave, longitudinal cohort study of same-sex attracted parents. The sample includes lesbian, gay, bisexual and transgender parents in Australia and New Zealand (including single parents within these categories) caring for any children under the age of 18 years. The study will be conducted over six years from 2008 to 2014. Quantitative data are to be collected via three on-line surveys in 2008, 2010 and 2012 from the cohort of parents recruited in Wave1. Qualitative data will be collected via interviews with purposively selected subsamples in 2012 and 2013. Data collection began in 2008 and 355 respondents to Wave One of the study have agreed to participate in future surveys. Work is currently underway to increase this sample size. The methods and survey instruments are described. Discussion This study will make an important contribution to the existing research on same-sex parented families. Strengths of the study design include the longitudinal method, which will allow understanding of changes over time within internal family relationships and social supports. Further, the mixed method design enables triangulation of qualitative and quantitative data. A broad recruitment strategy has already enabled a large sample size with the inclusion of both gay men and lesbians. PMID:20211027

The Path to Graduation: A Model Interactive Web Site Design Supporting Doctoral Students

ERIC Educational Resources Information Center

Simmons-Johnson, Nicole

2012-01-01

Objective. This 2-phase mixed method study assessed 2nd-year doctoral students' and dissertation students' perceptions of the current Graduate School of Education dissertation support Web site, with implications for designing a model dissertation support Web site. Methods. Phase 1 collected quantitative and qualitative data through an…

Sexual Health Promotion Programme: Participants' Perspectives on Capacity Building

ERIC Educational Resources Information Center

Keogh, Brian; Daly, Louise; Sharek, Danika; De Vries, Jan; McCann, Edward; Higgins, Agnes

2016-01-01

Objectives: The aim of this study was to evaluate a Health Service Executive (HSE) Foundation Programme in Sexual Health Promotion (FPSHP) with a specific emphasis on capacity building. Design: A mixed-method design using both quantitative and qualitative methods was used to collect the data. Setting: The FPSHP was delivered to staff working in…

Experimental Methodology in English Teaching and Learning: Method Features, Validity Issues, and Embedded Experimental Design

ERIC Educational Resources Information Center

Lee, Jang Ho

2012-01-01

Experimental methods have played a significant role in the growth of English teaching and learning studies. The paper presented here outlines basic features of experimental design, including the manipulation of independent variables, the role and practicality of randomised controlled trials (RCTs) in educational research, and alternative methods…

Using Blended Creative Teaching: Improving a Teacher Education Course on Designing Materials for Young Children

ERIC Educational Resources Information Center

Lou, Shi-Jer; Chen, Nai-Ci; Tsai, Huei-Yin; Tseng, Kuo-Hung; Shih, Ru-Chu

2012-01-01

This study combined traditional classroom teaching methods and blogs with blended creative teaching as a new teaching method for the course "Design and Applications of Teaching Aids for Young Children." It aimed to improve the shortcomings of the traditional teaching approach by incorporating the "Asking, Thinking, Doing, and…

Comparison of Performance Due to Guided Hyperlearning, Unguided Hyperlearning, and Conventional Learning in Mathematics: An Empirical Study

ERIC Educational Resources Information Center

Fathurrohman, Maman; Porter, Anne; Worthy, Annette L.

2014-01-01

In this paper, the use of guided hyperlearning, unguided hyperlearning, and conventional learning methods in mathematics are compared. The design of the research involved a quasi-experiment with a modified single-factor multiple treatment design comparing the three learning methods, guided hyperlearning, unguided hyperlearning, and conventional…

Quantitative Imaging Biomarkers: A Review of Statistical Methods for Computer Algorithm Comparisons

PubMed Central

2014-01-01

Quantitative biomarkers from medical images are becoming important tools for clinical diagnosis, staging, monitoring, treatment planning, and development of new therapies. While there is a rich history of the development of quantitative imaging biomarker (QIB) techniques, little attention has been paid to the validation and comparison of the computer algorithms that implement the QIB measurements. In this paper we provide a framework for QIB algorithm comparisons. We first review and compare various study designs, including designs with the true value (e.g. phantoms, digital reference images, and zero-change studies), designs with a reference standard (e.g. studies testing equivalence with a reference standard), and designs without a reference standard (e.g. agreement studies and studies of algorithm precision). The statistical methods for comparing QIB algorithms are then presented for various study types using both aggregate and disaggregate approaches. We propose a series of steps for establishing the performance of a QIB algorithm, identify limitations in the current statistical literature, and suggest future directions for research. PMID:24919829

Biomimetic design processes in architecture: morphogenetic and evolutionary computational design.

PubMed

Menges, Achim

2012-03-01

Design computation has profound impact on architectural design methods. This paper explains how computational design enables the development of biomimetic design processes specific to architecture, and how they need to be significantly different from established biomimetic processes in engineering disciplines. The paper first explains the fundamental difference between computer-aided and computational design in architecture, as the understanding of this distinction is of critical importance for the research presented. Thereafter, the conceptual relation and possible transfer of principles from natural morphogenesis to design computation are introduced and the related developments of generative, feature-based, constraint-based, process-based and feedback-based computational design methods are presented. This morphogenetic design research is then related to exploratory evolutionary computation, followed by the presentation of two case studies focusing on the exemplary development of spatial envelope morphologies and urban block morphologies.

Application of Optimization Techniques to Design of Unconventional Rocket Nozzle Configurations

NASA Technical Reports Server (NTRS)

Follett, W.; Ketchum, A.; Darian, A.; Hsu, Y.

1996-01-01

Several current rocket engine concepts such as the bell-annular tri-propellant engine, and the linear aerospike being proposed for the X-33 require unconventional three dimensional rocket nozzles which must conform to rectangular or sector shaped envelopes to meet integration constraints. These types of nozzles exist outside the current experience database, therefore, the application of efficient design methods for these propulsion concepts is critical to the success of launch vehicle programs. The objective of this work is to optimize several different nozzle configurations, including two- and three-dimensional geometries. Methodology includes coupling computational fluid dynamic (CFD) analysis to genetic algorithms and Taguchi methods as well as implementation of a streamline tracing technique. Results of applications are shown for several geometeries including: three dimensional thruster nozzles with round or super elliptic throats and rectangualar exits, two- and three-dimensional thrusters installed within a bell nozzle, and three dimensional thrusters with round throats and sector shaped exits. Due to the novel designs considered for this study, there is little experience which can be used to guide the effort and limit the design space. With a nearly infinite parameter space to explore, simple parametric design studies cannot possibly search the entire design space within the time frame required to impact the design cycle. For this reason, robust and efficient optimization methods are required to explore and exploit the design space to achieve high performance engine designs. Five case studies which examine the application of various techniques in the engineering environment are presented in this paper.

Automated a complex computer aided design concept generated using macros programming

NASA Astrophysics Data System (ADS)

Rizal Ramly, Mohammad; Asrokin, Azharrudin; Abd Rahman, Safura; Zulkifly, Nurul Ain Md

2013-12-01

Changing a complex Computer Aided design profile such as car and aircraft surfaces has always been difficult and challenging. The capability of CAD software such as AutoCAD and CATIA show that a simple configuration of a CAD design can be easily modified without hassle, but it is not the case with complex design configuration. Design changes help users to test and explore various configurations of the design concept before the production of a model. The purpose of this study is to look into macros programming as parametric method of the commercial aircraft design. Macros programming is a method where the configurations of the design are done by recording a script of commands, editing the data value and adding a certain new command line to create an element of parametric design. The steps and the procedure to create a macro programming are discussed, besides looking into some difficulties during the process of creation and advantage of its usage. Generally, the advantages of macros programming as a method of parametric design are; allowing flexibility for design exploration, increasing the usability of the design solution, allowing proper contained by the model while restricting others and real time feedback changes.

Hidden in Plain Sight: A Crowdsourced Public Art Contest to Make Automated External Defibrillators More Visible

PubMed Central

Griffis, Heather M.; Kilaru, Austin S.; Sellers, Allison M.; Hershey, John C.; Hill, Shawndra S.; Kramer-Golinkoff, Emily; Nadkarni, Lindsay; Debski, Margaret M.; Padrez, Kevin A.; Becker, Lance B.; Asch, David A.

2014-01-01

Objectives. We sought to explore the feasibility of using a crowdsourcing study to promote awareness about automated external defibrillators (AEDs) and their locations. Methods. The Defibrillator Design Challenge was an online initiative that asked the public to create educational designs that would enhance AED visibility, which took place over 8 weeks, from February 6, 2014, to April 6, 2014. Participants were encouraged to vote for AED designs and share designs on social media for points. Using a mixed-methods study design, we measured participant demographics and motivations, design characteristics, dissemination, and Web site engagement. Results. Over 8 weeks, there were 13 992 unique Web site visitors; 119 submitted designs and 2140 voted. The designs were shared 48 254 times on Facebook and Twitter. Most designers–voters reported that they participated to contribute to an important cause (44%) rather than to win money (0.8%). Design themes included: empowerment, location awareness, objects (e.g., wings, lightning, batteries, lifebuoys), and others. Conclusions. The Defibrillator Design Challenge engaged a broad audience to generate AED designs and foster awareness. This project provides a framework for using design and contest architecture to promote health messages. PMID:25320902

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

ERIC Educational Resources Information Center

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…

Modified Toxicity Probability Interval Design: A Safer and More Reliable Method Than the 3 + 3 Design for Practical Phase I Trials

PubMed Central

Ji, Yuan; Wang, Sue-Jane

2013-01-01

The 3 + 3 design is the most common choice among clinicians for phase I dose-escalation oncology trials. In recent reviews, more than 95% of phase I trials have been based on the 3 + 3 design. Given that it is intuitive and its implementation does not require a computer program, clinicians can conduct 3 + 3 dose escalations in practice with virtually no logistic cost, and trial protocols based on the 3 + 3 design pass institutional review board and biostatistics reviews quickly. However, the performance of the 3 + 3 design has rarely been compared with model-based designs in simulation studies with matched sample sizes. In the vast majority of statistical literature, the 3 + 3 design has been shown to be inferior in identifying true maximum-tolerated doses (MTDs), although the sample size required by the 3 + 3 design is often orders-of-magnitude smaller than model-based designs. In this article, through comparative simulation studies with matched sample sizes, we demonstrate that the 3 + 3 design has higher risks of exposing patients to toxic doses above the MTD than the modified toxicity probability interval (mTPI) design, a newly developed adaptive method. In addition, compared with the mTPI design, the 3 + 3 design does not yield higher probabilities in identifying the correct MTD, even when the sample size is matched. Given that the mTPI design is equally transparent, costless to implement with free software, and more flexible in practical situations, we highly encourage its adoption in early dose-escalation studies whenever the 3 + 3 design is also considered. We provide free software to allow direct comparisons of the 3 + 3 design with other model-based designs in simulation studies with matched sample sizes. PMID:23569307

Participatory Design in Gerontechnology: A Systematic Literature Review.

PubMed

Merkel, Sebastian; Kucharski, Alexander

2018-05-19

Participatory design (PD) is widely used within gerontechnology but there is no common understanding about which methods are used for what purposes. This review aims to examine what different forms of PD exist in the field of gerontechnology and how these can be categorized. We conducted a systematic literature review covering several databases. The search strategy was based on 3 elements: (1) participatory methods and approaches with (2) older persons aiming at developing (3) technology for older people. Our final review included 26 studies representing a variety of technologies designed/developed and methods/instruments applied. According to the technologies, the publications reviewed can be categorized in 3 groups: Studies that (1) use already existing technology with the aim to find new ways of use; (2) aim at creating new devices; (3) test and/or modify prototypes. The implementation of PD depends on the questions: Why a participatory approach is applied, who is involved as future user(s), when those future users are involved, and how they are incorporated into the innovation process. There are multiple ways, methods, and instruments to integrate users into the innovation process. Which methods should be applied, depends on the context. However, most studies do not evaluate if participatory approaches will lead to a better acceptance and/or use of the co-developed products. Therefore, participatory design should follow a comprehensive strategy, starting with the users' needs and ending with an evaluation if the applied methods have led to better results.

Use of experimental design in the investigation of stir bar sorptive extraction followed by ultra-high-performance liquid chromatography-tandem mass spectrometry for the analysis of explosives in water samples.

PubMed

Schramm, Sébastien; Vailhen, Dominique; Bridoux, Maxime Cyril

2016-02-12

A method for the sensitive quantification of trace amounts of organic explosives in water samples was developed by using stir bar sorptive extraction (SBSE) followed by liquid desorption and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The proposed method was developed and optimized using a statistical design of experiment approach. Use of experimental designs allowed a complete study of 10 factors and 8 analytes including nitro-aromatics, amino-nitro-aromatics and nitric esters. The liquid desorption study was performed using a full factorial experimental design followed by a kinetic study. Four different variables were tested here: the liquid desorption mode (stirring or sonication), the chemical nature of the stir bar (PDMS or PDMS-PEG), the composition of the liquid desorption phase and finally, the volume of solvent used for the liquid desorption. On the other hand, the SBSE extraction study was performed using a Doehlert design. SBSE extraction conditions such as extraction time profiles, sample volume, modifier addition, and acetic acid addition were examined. After optimization of the experimental parameters, sensitivity was improved by a factor 5-30, depending on the compound studied, due to the enrichment factors reached using the SBSE method. Limits of detection were in the ng/L level for all analytes studied. Reproducibility of the extraction with different stir bars was close to the reproducibility of the analytical method (RSD between 4 and 16%). Extractions in various water sample matrices (spring, mineral and underground water) have shown similar enrichment compared to ultrapure water, revealing very low matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

Numerical study of a permanent magnet linear generator for ship motion energy conversion

NASA Astrophysics Data System (ADS)

Mahmuddin, Faisal; Gunadin, Indar Chaerah; Akhir, Anshar Yaumil

2017-02-01

In order to harvest kinetic energy of a ship moving in waves, a permanent magnet linear generator is designed and simulated in the present study. For the sake of simplicity, only heave motion which will be considered in this preliminary study. The dimension of the generator is designed based on the dimension of the ship. Moreover, in order to designed an optimal design of rotor and stator, the average vertical displacement of heave motion is needed. For this purpose, a numerical method called New Strip Method (NSM) is employed to compute the motions of the ship. With NSM, the ship hull is divided into several strips and the hydrodynamics forces are computed on each strip. Moreover, because the ship is assumed to be slender, the total forces are obtained by integrating the force on each strip. After the motions can be determined, the optimal design of the generator is designed and simulated. The performance of the generator in terms of force, magnetic flux, losses, current and induced voltage which are the primary parameters of the linear generator performance, are evaluated using a finite element analysis software named Maxwell. From the study, a linear generator for converting heave motions is designed so that the produced power from the designed generator can be determined.

The role of mixed methods in improved cookstove research.

PubMed

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.

Comparing problem-based learning and lecture as methods to teach whole-systems design to engineering students

NASA Astrophysics Data System (ADS)

Dukes, Michael Dickey

The objective of this research is to compare problem-based learning and lecture as methods to teach whole-systems design to engineering students. A case study, Appendix A, exemplifying successful whole-systems design was developed and written by the author in partnership with the Rocky Mountain Institute. Concepts to be tested were then determined, and a questionnaire was developed to test students' preconceptions. A control group of students was taught using traditional lecture methods, and a sample group of students was taught using problem-based learning methods. After several weeks, the students were given the same questionnaire as prior to the instruction, and the data was analyzed to determine if the teaching methods were effective in correcting misconceptions. A statistically significant change in the students' preconceptions was observed in both groups on the topic of cost related to the design process. There was no statistically significant change in the students' preconceptions concerning the design process, technical ability within five years, and the possibility of drastic efficiency gains with current technologies. However, the results were inconclusive in determining that problem-based learning is more effective than lecture as a method for teaching the concept of whole-systems design, or vice versa.

EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 28, PCB'S (POLYCHLORINATED BIPHENYLS) IN OIL

EPA Science Inventory

This report describes the experimental design and the results of the validation study for two analytical methods to detect polychlorinated byphenyls in oil. The methods analyzed for four PCB Aroclors (1016, 1242, 1254, and 1260), 2-chlorobiphenyl, and decachlorobiphenyl. The firs...

Summary of lessons learned from the MDOT MEPDG materials library study.

DOT National Transportation Integrated Search

2010-06-01

From 2004 to 2009, Burns Cooley Dennis, Inc. (BCD) participated in two important research studies designed to populate the materials library for implementation of the new Mechanistic-Empirical pavement design method (MEPDG) in Mississippi. The purpos...

Quasi-experimental study designs series-paper 10: synthesizing evidence for effects collected from quasi-experimental studies presents surmountable challenges.

PubMed

Becker, Betsy Jane; Aloe, Ariel M; Duvendack, Maren; Stanley, T D; Valentine, Jeffrey C; Fretheim, Atle; Tugwell, Peter

2017-09-01

To outline issues of importance to analytic approaches to the synthesis of quasi-experiments (QEs) and to provide a statistical model for use in analysis. We drew on studies of statistics, epidemiology, and social-science methodology to outline methods for synthesis of QE studies. The design and conduct of QEs, effect sizes from QEs, and moderator variables for the analysis of those effect sizes were discussed. Biases, confounding, design complexities, and comparisons across designs offer serious challenges to syntheses of QEs. Key components of meta-analyses of QEs were identified, including the aspects of QE study design to be coded and analyzed. Of utmost importance are the design and statistical controls implemented in the QEs. Such controls and any potential sources of bias and confounding must be modeled in analyses, along with aspects of the interventions and populations studied. Because of such controls, effect sizes from QEs are more complex than those from randomized experiments. A statistical meta-regression model that incorporates important features of the QEs under review was presented. Meta-analyses of QEs provide particular challenges, but thorough coding of intervention characteristics and study methods, along with careful analysis, should allow for sound inferences. Copyright © 2017 Elsevier Inc. All rights reserved.

Inverse design of an ultra-compact broadband optical diode based on asymmetric spatial mode conversion

PubMed Central

Callewaert, Francois; Butun, Serkan; Li, Zhongyang; Aydin, Koray

2016-01-01

The objective-first inverse-design algorithm is used to design an ultra-compact optical diode. Based on silicon and air only, this optical diode relies on asymmetric spatial mode conversion between the left and right ports. The first even mode incident from the left port is transmitted to the right port after being converted into an odd mode. On the other hand, same mode incident from the right port is reflected back by the optical diode dielectric structure. The convergence and performance of the algorithm are studied, along with a transform method that converts continuous permittivity medium into a binary material design. The optimal device is studied with full-wave electromagnetic simulations to compare its behavior under right and left incidences, in 2D and 3D settings as well. A parametric study is designed to understand the impact of the design space size and initial conditions on the optimized devices performance. A broadband optical diode behavior is observed after optimization, with a large rejection ratio between the two transmission directions. This illustrates the potential of the objective-first inverse-design method to design ultra-compact broadband photonic devices. PMID:27586852

Development Research of a Teachers' Educational Performance Support System: The Practices of Design, Development, and Evaluation

ERIC Educational Resources Information Center

Hung, Wei-Chen; Smith, Thomas J.; Harris, Marian S.; Lockard, James

2010-01-01

This study adopted design and development research methodology (Richey & Klein, "Design and development research: Methods, strategies, and issues," 2007) to systematically investigate the process of applying instructional design principles, human-computer interaction, and software engineering to a performance support system (PSS) for behavior…

The design-build contracting methodology for transportation projects : a review of practice and evaluation for Connecticut applications.

DOT National Transportation Integrated Search

2010-06-10

Two primary contracting methods are used by most state transportation agencies to : design and build infrastructure: design-bid-build and design-build. The objective : of this study is to conduct a literature review to identify how ConnDOTs use of...

Using Story Structure for Lesson Design in Teaching about Sexual Assault

ERIC Educational Resources Information Center

Erbe, Ryan G.; Kearns, Katherine D.

2016-01-01

The present pilot study examines the use of story structure for lesson design to promote student engagement in a lesson focusing on sexual assault prevention. The effect of the story-based lesson on undergraduates' knowledge and perceptions of sexual assault was studied using a quasi-experimental mixed methods design. Results of the study…

Students' Preferences and Opinions on Design of a Mobile Marketing Education Application

ERIC Educational Resources Information Center

Ozata, Zeynep; Ozdama Keskin, Nilgun

2014-01-01

The purpose of this study was to define and better understand business school students' opinions and preferences on the design of a mobile marketing education application. To accomplish this purpose an explanatory mixed methods study design was used and the data was collected sequentially. First, a questionnaire was conducted with 168 business…

Interplay of Computer and Paper-Based Sketching in Graphic Design

ERIC Educational Resources Information Center

Pan, Rui; Kuo, Shih-Ping; Strobel, Johannes

2013-01-01

The purpose of this study is to investigate student designers' attitude and choices towards the use of computers and paper sketches when involved in a graphic design process. 65 computer graphic technology undergraduates participated in this research. A mixed method study with survey and in-depth interviews was applied to answer the research…

Youth as Design Partners: Age-Appropriate Websites for Middle and High School Students

ERIC Educational Resources Information Center

Chow, Anthony S.; Smith, Kathelene McCarty; Sun, Katherine

2012-01-01

This study explored the impact of using best practices identified in previous studies in designing age-appropriate websites for middle and high school youth. Utilizing a mixed-method approach, 31 middle and 22 high school youth took part in six focus groups across four states. Participants were introduced to a website specifically designed for…

Contemplating a New Model for Air Force Aerospace Medical Technician Skills Sustainment Training

DTIC Science & Technology

2006-03-01

qualitative research designs. The major designs described by these researchers included: grounded theory , narrative research ... phenomenological research , ethnographies , content analysis, and case study . Because each of these designs can stand alone as an individual research ...exploratory, embedded, single case study . A mixed methods research approach will be applied in an effort to discover

Refining a Competency Model for Instructional Designers in the Context of Online Higher Education

ERIC Educational Resources Information Center

Park, Jae-Young; Luo, Heng

2017-01-01

This study investigates the instructional designers (IDs) competencies essential for the context of online higher education, and has selected an instruction design unit in a research university as a case of investigation. To identify and compare IDs competencies at organizational and individual levels, this study employed a mixed method to collect…

The reduction of intoxication and disorder in premises licensed to serve alcohol: An exploratory randomised controlled trial

PubMed Central

2010-01-01

Background Licensed premises offer a valuable point of intervention to reduce alcohol-related harm. Objective To describe the research design for an exploratory trial examining the feasibility and acceptability of a premises-level intervention designed to reduce severe intoxication and related disorder. The study also aims to assess the feasibility of a potential future large scale effectiveness trial and provide information on key trial design parameters including inclusion criteria, premises recruitment methods, strategies to implement the intervention and trial design, outcome measures, data collection methods and intra-cluster correlations. Design A randomised controlled trial in licensed premises that had experienced at least one assault in the year preceding the intervention, documented in police or hospital Emergency Department (ED) records. Premises were recruited from four study areas by piloting four recruitment strategies of varying intensity. Thirty two licensed premises were grouped into matched pairs to reduce potential bias and randomly allocated to the control or intervention condition. The study included a nested process evaluation to provide information on intervention acceptability and implementation. Outcome measures included police-recorded violent incidents, assault-related attendances at each premises' local ED and patron Breath Alcohol Concentration assessed on exiting and entering study premises. Results The most successful recruitment method involved local police licensing officers and yielded a 100% success rate. Police-records of violence provided the most appropriate source of data about disorder at the premises level. Conclusion The methodology of an exploratory trial is presented and despite challenges presented by the study environment it is argued an exploratory trial is warranted. Initial investigations in recruitment methods suggest that study premises should be recruited with the assistance of police officers. Police data were of sufficient quality to identify disorder and street surveys are a feasible method for measuring intoxication at the individual level. Trial registration UKCRN 7090; ISRCTN: 80875696 Funding Medical Research Council (G0701758) to Simon Moore, Simon Murphy, Laurence Moore and Jonathan Shepherd PMID:20946634

Parametric design and analysis on the landing gear of a planet lander using the response surface method

NASA Astrophysics Data System (ADS)

Zheng, Guang; Nie, Hong; Luo, Min; Chen, Jinbao; Man, Jianfeng; Chen, Chuanzhi; Lee, Heow Pueh

2018-07-01

The purpose of this paper is to obtain the design parameter-landing response relation for designing the configuration of the landing gear in a planet lander quickly. To achieve this, parametric studies on the landing gear are carried out using the response surface method (RSM), based on a single landing gear landing model validated by experimental results. According to the design of experiment (DOE) results of the landing model, the RS (response surface)-functions of the three crucial landing responses are obtained, and the sensitivity analysis (SA) of the corresponding parameters is performed. Also, two multi-objective optimizations designs on the landing gear are carried out. The analysis results show that the RS (response surface)-model performs well for the landing response design process, with a minimum fitting accuracy of 98.99%. The most sensitive parameters for the three landing response are the design size of the buffers, struts friction and the diameter of the bending beam. Moreover, the good agreement between the simulated model and RS-model results are obtained in two optimized designs, which show that the RS-model coupled with the FE (finite element)-method is an efficient method to obtain the design configuration of the landing gear.

The system design and performance test of hybrid vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Dwiyantoro, Bambang Arip; Suphandani, Vivien

2017-04-01

Vertical axis wind turbine is a tool that is being developed to generate energy from wind. One cause is still little use of wind energy is the design of wind turbines that are less precise. Therefore in this study will be developed the system design of hybrid vertical axis wind turbine and tested performance with experimental methods. The design of hybrid turbine based on a straight bladed Darrieus turbine along with a double step Savonius turbine. The method used to design wind turbines is by studying literature, analyzing the critical parts of a wind turbine and the structure of the optimal design. Wind turbine prototype of the optimal design characteristic tests in the wind tunnel experimentally by varying the speed of the wind. From the experimental results show that the greater the wind speed, the greater the wind turbine rotation and torque is raised. The hybrid vertical axis wind turbine has much better self-starting and better conversion efficiency.

Multiple imputation of missing data in nested case-control and case-cohort studies.

PubMed

Keogh, Ruth H; Seaman, Shaun R; Bartlett, Jonathan W; Wood, Angela M

2018-06-05

The nested case-control and case-cohort designs are two main approaches for carrying out a substudy within a prospective cohort. This article adapts multiple imputation (MI) methods for handling missing covariates in full-cohort studies for nested case-control and case-cohort studies. We consider data missing by design and data missing by chance. MI analyses that make use of full-cohort data and MI analyses based on substudy data only are described, alongside an intermediate approach in which the imputation uses full-cohort data but the analysis uses only the substudy. We describe adaptations to two imputation methods: the approximate method (MI-approx) of White and Royston () and the "substantive model compatible" (MI-SMC) method of Bartlett et al. (). We also apply the "MI matched set" approach of Seaman and Keogh () to nested case-control studies, which does not require any full-cohort information. The methods are investigated using simulation studies and all perform well when their assumptions hold. Substantial gains in efficiency can be made by imputing data missing by design using the full-cohort approach or by imputing data missing by chance in analyses using the substudy only. The intermediate approach brings greater gains in efficiency relative to the substudy approach and is more robust to imputation model misspecification than the full-cohort approach. The methods are illustrated using the ARIC Study cohort. Supplementary Materials provide R and Stata code. © 2018, The International Biometric Society.

Multidisciplinary design optimization using genetic algorithms

NASA Technical Reports Server (NTRS)

Unal, Resit

1994-01-01

Multidisciplinary design optimization (MDO) is an important step in the conceptual design and evaluation of launch vehicles since it can have a significant impact on performance and life cycle cost. The objective is to search the system design space to determine values of design variables that optimize the performance characteristic subject to system constraints. Gradient-based optimization routines have been used extensively for aerospace design optimization. However, one limitation of gradient based optimizers is their need for gradient information. Therefore, design problems which include discrete variables can not be studied. Such problems are common in launch vehicle design. For example, the number of engines and material choices must be integer values or assume only a few discrete values. In this study, genetic algorithms are investigated as an approach to MDO problems involving discrete variables and discontinuous domains. Optimization by genetic algorithms (GA) uses a search procedure which is fundamentally different from those gradient based methods. Genetic algorithms seek to find good solutions in an efficient and timely manner rather than finding the best solution. GA are designed to mimic evolutionary selection. A population of candidate designs is evaluated at each iteration, and each individual's probability of reproduction (existence in the next generation) depends on its fitness value (related to the value of the objective function). Progress toward the optimum is achieved by the crossover and mutation operations. GA is attractive since it uses only objective function values in the search process, so gradient calculations are avoided. Hence, GA are able to deal with discrete variables. Studies report success in the use of GA for aircraft design optimization studies, trajectory analysis, space structure design and control systems design. In these studies reliable convergence was achieved, but the number of function evaluations was large compared with efficient gradient methods. Applicaiton of GA is underway for a cost optimization study for a launch-vehicle fuel-tank and structural design of a wing. The strengths and limitations of GA for launch vehicle design optimization is studied.

Using experimental design to define boundary manikins.

PubMed

Bertilsson, Erik; Högberg, Dan; Hanson, Lars

2012-01-01

When evaluating human-machine interaction it is central to consider anthropometric diversity to ensure intended accommodation levels. A well-known method is the use of boundary cases where manikins with extreme but likely measurement combinations are derived by mathematical treatment of anthropometric data. The supposition by that method is that the use of these manikins will facilitate accommodation of the expected part of the total, less extreme, population. In literature sources there are differences in how many and in what way these manikins should be defined. A similar field to the boundary case method is the use of experimental design in where relationships between affecting factors of a process is studied by a systematic approach. This paper examines the possibilities to adopt methodology used in experimental design to define a group of manikins. Different experimental designs were adopted to be used together with a confidence region and its axes. The result from the study shows that it is possible to adapt the methodology of experimental design when creating groups of manikins. The size of these groups of manikins depends heavily on the number of key measurements but also on the type of chosen experimental design.

Assessing Reflective Thinking in Solving Design Problems: The Development of a Questionnaire

ERIC Educational Resources Information Center

Hong, Yi-Chun; Choi, Ikseon

2015-01-01

Reflection is a critical factor in solving design problems. Using good methods to observe designers' reflection is essential to inform the design of the learning environments that support the development of design problem-solving skills. In this study, we have developed and validated a novel self-reporting questionnaire as an efficient instrument…

DAKOTA Design Analysis Kit for Optimization and Terascale

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

Adams, Brian M.; Dalbey, Keith R.; Eldred, Michael S.

2010-02-24

The DAKOTA (Design Analysis Kit for Optimization and Terascale Applications) toolkit provides a flexible and extensible interface between simulation codes (computational models) and iterative analysis methods. By employing object-oriented design to implement abstractions of the key components required for iterative systems analyses, the DAKOTA toolkit provides a flexible and extensible problem-solving environment for design and analysis of computational models on high performance computers.A user provides a set of DAKOTA commands in an input file and launches DAKOTA. DAKOTA invokes instances of the computational models, collects their results, and performs systems analyses. DAKOTA contains algorithms for optimization with gradient and nongradient-basedmore » methods; uncertainty quantification with sampling, reliability, polynomial chaos, stochastic collocation, and epistemic methods; parameter estimation with nonlinear least squares methods; and sensitivity/variance analysis with design of experiments and parameter study methods. These capabilities may be used on their own or as components within advanced strategies such as hybrid optimization, surrogate-based optimization, mixed integer nonlinear programming, or optimization under uncertainty. Services for parallel computing, simulation interfacing, approximation modeling, fault tolerance, restart, and graphics are also included.« less

Epidemiological designs for vaccine safety assessment: methods and pitfalls.

PubMed

Andrews, Nick

2012-09-01

Three commonly used designs for vaccine safety assessment post licensure are cohort, case-control and self-controlled case series. These methods are often used with routine health databases and immunisation registries. This paper considers the issues that may arise when designing an epidemiological study, such as understanding the vaccine safety question, case definition and finding, limitations of data sources, uncontrolled confounding, and pitfalls that apply to the individual designs. The example of MMR and autism, where all three designs have been used, is presented to help consider these issues. Copyright © 2011 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Alternating treatments design: one strategy for comparing the effects of two treatments in a single subject.

PubMed Central

Barlow, D H; Hayes, S C

1979-01-01

A little used and often confused design, capable of comparing two treatments within a single subject, has been termed, variously, a multielement baseline design, a multiple schedule design, and a randomization design. The background of these terms is reviewed, and a new, more descriptive term, Alternating Treatments Design, is proposed. Critical differences between this design and a Simultaneous Treatment Design are outlined, and experimental questions answerable by each design are noted. Potential problems with multiple treatment interference in this procedure are divided into sequential confounding, carryover effects, and alternation effects and the importance of these issues vis-a-vis other single-case experimental designs is considered. Methods of minimizing multiple treatment interference as well as methods of studying these effects are outlined. Finally, appropriate uses of Alternating Treatments Designs are described and discussed in the context of recent examples. PMID:489478

Optical System Design for Noncontact, Normal Incidence, THz Imaging of in vivo Human Cornea.

PubMed

Sung, Shijun; Dabironezare, Shahab; Llombart, Nuria; Selvin, Skyler; Bajwa, Neha; Chantra, Somporn; Nowroozi, Bryan; Garritano, James; Goell, Jacob; Li, Alex; Deng, Sophie X; Brown, Elliott; Grundfest, Warren S; Taylor, Zachary D

2018-01-01

Reflection mode Terahertz (THz) imaging of corneal tissue water content (CTWC) is a proposed method for early, accurate detection and study of corneal diseases. Despite promising results from ex vivo and in vivo cornea studies, interpretation of the reflectivity data is confounded by the contact between corneal tissue and dielectric windows used to flatten the imaging field. Herein, we present an optical design for non-contact THz imaging of cornea. A beam scanning methodology performs angular, normal incidence sweeps of a focused beam over the corneal surface while keeping the source, detector, and patient stationary. A quasioptical analysis method is developed to analyze the theoretical resolution and imaging field intensity profile. These results are compared to the electric field distribution computed with a physical optics analysis code. Imaging experiments validate the optical theories behind the design and suggest that quasioptical methods are sufficient for designing of THz corneal imaging systems. Successful imaging operations support the feasibility of non-contact in vivo imaging. We believe that this optical system design will enable the first, clinically relevant, in vivo exploration of CTWC using THz technology.

Finding gene clusters for a replicated time course study

PubMed Central

2014-01-01

Background Finding genes that share similar expression patterns across samples is an important question that is frequently asked in high-throughput microarray studies. Traditional clustering algorithms such as K-means clustering and hierarchical clustering base gene clustering directly on the observed measurements and do not take into account the specific experimental design under which the microarray data were collected. A new model-based clustering method, the clustering of regression models method, takes into account the specific design of the microarray study and bases the clustering on how genes are related to sample covariates. It can find useful gene clusters for studies from complicated study designs such as replicated time course studies. Findings In this paper, we applied the clustering of regression models method to data from a time course study of yeast on two genotypes, wild type and YOX1 mutant, each with two technical replicates, and compared the clustering results with K-means clustering. We identified gene clusters that have similar expression patterns in wild type yeast, two of which were missed by K-means clustering. We further identified gene clusters whose expression patterns were changed in YOX1 mutant yeast compared to wild type yeast. Conclusions The clustering of regression models method can be a valuable tool for identifying genes that are coordinately transcribed by a common mechanism. PMID:24460656

Joint design of large-tip-angle parallel RF pulses and blipped gradient trajectories.

PubMed

Cao, Zhipeng; Donahue, Manus J; Ma, Jun; Grissom, William A

2016-03-01

To design multichannel large-tip-angle kT-points and spokes radiofrequency (RF) pulses and gradient waveforms for transmit field inhomogeneity compensation in high field magnetic resonance imaging. An algorithm to design RF subpulse weights and gradient blip areas is proposed to minimize a magnitude least-squares cost function that measures the difference between realized and desired state parameters in the spin domain, and penalizes integrated RF power. The minimization problem is solved iteratively with interleaved target phase updates, RF subpulse weights updates using the conjugate gradient method with optimal control-based derivatives, and gradient blip area updates using the conjugate gradient method. Two-channel parallel transmit simulations and experiments were conducted in phantoms and human subjects at 7 T to demonstrate the method and compare it to small-tip-angle-designed pulses and circularly polarized excitations. The proposed algorithm designed more homogeneous and accurate 180° inversion and refocusing pulses than other methods. It also designed large-tip-angle pulses on multiple frequency bands with independent and joint phase relaxation. Pulses designed by the method improved specificity and contrast-to-noise ratio in a finger-tapping spin echo blood oxygen level dependent functional magnetic resonance imaging study, compared with circularly polarized mode refocusing. A joint RF and gradient waveform design algorithm was proposed and validated to improve large-tip-angle inversion and refocusing at ultrahigh field. © 2015 Wiley Periodicals, Inc.

The Correction of Myopia Evaluation Trial: lessons from the study design.

PubMed

Hyman, L; Gwiazda, J

2004-01-01

The Correction of Myopia Evaluation Trial (COMET), a multicentre clinical trial based in 4 schools of optometry in the United States, evaluated the effect of progressive addition lenses versus single vision lenses on myopia progression in an ethnically diverse group of 469 myopic children aged 6 to 11 years. Completion of the clinical trial phase of the study provides an opportunity to evaluate aspects of the study design that contribute to its success. This article describes aspects of the study design that were influential in ensuring the smooth conduct of COMET. These include a dedicated team of investigators, an organisational structure with strong leadership and an independent Co-ordinating Centre, regular communication among investigators, flexible and creative approaches to recruitment and retention, sensitivity to concerns for child safety and child participation, and methods for enhancing and monitoring data reliability. The experience with COMET has provided a number of valuable lessons for all aspects of the study design that should benefit the development and implementation of future clinical trials, particularly those done in similar populations of children. The use of a carefully designed protocol using standard methods by dedicated members of the study team is essential in ensuring achievement of the study aims.

A probabilistic approach to aircraft design emphasizing stability and control uncertainties

NASA Astrophysics Data System (ADS)

Delaurentis, Daniel Andrew

In order to address identified deficiencies in current approaches to aerospace systems design, a new method has been developed. This new method for design is based on the premise that design is a decision making activity, and that deterministic analysis and synthesis can lead to poor, or misguided decision making. This is due to a lack of disciplinary knowledge of sufficient fidelity about the product, to the presence of uncertainty at multiple levels of the aircraft design hierarchy, and to a failure to focus on overall affordability metrics as measures of goodness. Design solutions are desired which are robust to uncertainty and are based on the maximum knowledge possible. The new method represents advances in the two following general areas. 1. Design models and uncertainty. The research performed completes a transition from a deterministic design representation to a probabilistic one through a modeling of design uncertainty at multiple levels of the aircraft design hierarchy, including: (1) Consistent, traceable uncertainty classification and representation; (2) Concise mathematical statement of the Probabilistic Robust Design problem; (3) Variants of the Cumulative Distribution Functions (CDFs) as decision functions for Robust Design; (4) Probabilistic Sensitivities which identify the most influential sources of variability. 2. Multidisciplinary analysis and design. Imbedded in the probabilistic methodology is a new approach for multidisciplinary design analysis and optimization (MDA/O), employing disciplinary analysis approximations formed through statistical experimentation and regression. These approximation models are a function of design variables common to the system level as well as other disciplines. For aircraft, it is proposed that synthesis/sizing is the proper avenue for integrating multiple disciplines. Research hypotheses are translated into a structured method, which is subsequently tested for validity. Specifically, the implementation involves the study of the relaxed static stability technology for a supersonic commercial transport aircraft. The probabilistic robust design method is exercised resulting in a series of robust design solutions based on different interpretations of "robustness". Insightful results are obtained and the ability of the method to expose trends in the design space are noted as a key advantage.

Variation in Research Designs Used to Test the Effectiveness of Dissemination and Implementation Strategies: A Review.

PubMed

Mazzucca, Stephanie; Tabak, Rachel G; Pilar, Meagan; Ramsey, Alex T; Baumann, Ana A; Kryzer, Emily; Lewis, Ericka M; Padek, Margaret; Powell, Byron J; Brownson, Ross C

2018-01-01

The need for optimal study designs in dissemination and implementation (D&I) research is increasingly recognized. Despite the wide range of study designs available for D&I research, we lack understanding of the types of designs and methodologies that are routinely used in the field. This review assesses the designs and methodologies in recently proposed D&I studies and provides resources to guide design decisions. We reviewed 404 study protocols published in the journal Implementation Science from 2/2006 to 9/2017. Eligible studies tested the efficacy or effectiveness of D&I strategies (i.e., not effectiveness of the underlying clinical or public health intervention); had a comparison by group and/or time; and used ≥1 quantitative measure. Several design elements were extracted: design category (e.g., randomized); design type [e.g., cluster randomized controlled trial (RCT)]; data type (e.g., quantitative); D&I theoretical framework; levels of treatment assignment, intervention, and measurement; and country in which the research was conducted. Each protocol was double-coded, and discrepancies were resolved through discussion. Of the 404 protocols reviewed, 212 (52%) studies tested one or more implementation strategy across 208 manuscripts, therefore meeting inclusion criteria. Of the included studies, 77% utilized randomized designs, primarily cluster RCTs. The use of alternative designs (e.g., stepped wedge) increased over time. Fewer studies were quasi-experimental (17%) or observational (6%). Many study design categories (e.g., controlled pre-post, matched pair cluster design) were represented by only one or two studies. Most articles proposed quantitative and qualitative methods (61%), with the remaining 39% proposing only quantitative. Half of protocols (52%) reported using a theoretical framework to guide the study. The four most frequently reported frameworks were Consolidated Framework for Implementing Research and RE-AIM ( n  = 16 each), followed by Promoting Action on Research Implementation in Health Services and Theoretical Domains Framework ( n  = 12 each). While several novel designs for D&I research have been proposed (e.g., stepped wedge, adaptive designs), the majority of the studies in our sample employed RCT designs. Alternative study designs are increasing in use but may be underutilized for a variety of reasons, including preference of funders or lack of awareness of these designs. Promisingly, the prevalent use of quantitative and qualitative methods together reflects methodological innovation in newer D&I research.

Design of the superconducting magnet for 9.4 Tesla whole-body magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Li, Y.; Wang, Q.; Dai, Y.; Ni, Z.; Zhu, X.; Li, L.; Zhao, B.; Chen, S.

2017-02-01

A superconducting magnet for 9.4 Tesla whole-body magnetic resonance imaging is designed and fabricated in Institute of Electrical Engineering, Chinese Academy of Sciences. In this paper, the electromagnetic design methods of the main coils and compensating coils are presented. Sensitivity analysis is performed for all superconducting coils. The design of the superconducting shimming coils is also presented and the design of electromagnetic decoupling of the Z2 coils from the main coils is introduced. Stress and strain analysis with both averaged and detailed models is performed with finite element method. A quench simulation code with anisotropic continuum model and control volume method is developed by us and is verified by experimental study. By means of the quench simulation code, the quench protection system for the 9.4 T magnet is designed for the main coils, the compensating coils and the shimming coils. The magnet cryostat design with zero helium boiling-off technology is also introduced.

Remotely controlling of mobile robots using gesture captured by the Kinect and recognized by machine learning method

NASA Astrophysics Data System (ADS)

Hsu, Roy CHaoming; Jian, Jhih-Wei; Lin, Chih-Chuan; Lai, Chien-Hung; Liu, Cheng-Ting

2013-01-01

The main purpose of this paper is to use machine learning method and Kinect and its body sensation technology to design a simple, convenient, yet effective robot remote control system. In this study, a Kinect sensor is used to capture the human body skeleton with depth information, and a gesture training and identification method is designed using the back propagation neural network to remotely command a mobile robot for certain actions via the Bluetooth. The experimental results show that the designed mobile robots remote control system can achieve, on an average, more than 96% of accurate identification of 7 types of gestures and can effectively control a real e-puck robot for the designed commands.

Quasi-modal vibration control by means of active control bearings

NASA Technical Reports Server (NTRS)

Nonami, K.; Fleming, D. P.

1986-01-01

This paper investigates a design method of an active control bearing system with only velocity feedback. The study provides a new quasi-modal control method for a control system design of an active control bearing system in which feedback coefficients are determined on the basis of a modal analysis. Although the number of sensors and actuators is small, this quasi-modal control method produces a control effect close to an ideal modal control.

Changes in Instructional System Design (ISD): Improving Training Product Delivery to United States Army Soldiers

DTIC Science & Technology

2005-03-18

simulation. This model is a basis of what is called discovery learning. Discovery learning is constructionist method of instruction, which is a concept in...2005 PAGES: 48 CLASSIFICATION: Unclassified The purpose of this study is to identify methods that could speed up the instructional system design...became obvious as the enemy attacked using asymmetric means and methods . For instance: during the war, a mine identification-training product was

Aerodynamic shape optimization directed toward a supersonic transport using sensitivity analysis

NASA Technical Reports Server (NTRS)

Baysal, Oktay

1995-01-01

This investigation was conducted from March 1994 to August 1995, primarily, to extend and implement the previously developed aerodynamic design optimization methodologies for the problems related to a supersonic transport design. These methods had demonstrated promise to improve the designs (more specifically, the shape) of aerodynamic surfaces, by coupling optimization algorithms (OA) with Computational Fluid Dynamics (CFD) algorithms via sensitivity analyses (SA) with surface definition methods from Computer Aided Design (CAD). The present extensions of this method and their supersonic implementations have produced wing section designs, delta wing designs, cranked-delta wing designs, and nacelle designs, all of which have been reported in the open literature. Despite the fact that these configurations were highly simplified to be of any practical or commercial use, they served the algorithmic and proof-of-concept objectives of the study very well. The primary cause for the configurational simplifications, other than the usual simplify-to-study the fundamentals reason, were the premature closing of the project. Only after the first of the originally intended three-year term, both the funds and the computer resources supporting the project were abruptly cut due to their severe shortages at the funding agency. Nonetheless, it was shown that the extended methodologies could be viable options in optimizing the design of not only an isolated single-component configuration, but also a multiple-component configuration in supersonic and viscous flow. This allowed designing with the mutual interference of the components being one of the constraints all along the evolution of the shapes.

Guidance for using mixed methods design in nursing practice research.

PubMed

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.

The Study of the Relationship between Probabilistic Design and Axiomatic Design Methodology. Volume 2

NASA Technical Reports Server (NTRS)

Onwubiko, Chin-Yere; Onyebueke, Landon

1996-01-01

The structural design, or the design of machine elements, has been traditionally based on deterministic design methodology. The deterministic method considers all design parameters to be known with certainty. This methodology is, therefore, inadequate to design complex structures that are subjected to a variety of complex, severe loading conditions. A nonlinear behavior that is dependent on stress, stress rate, temperature, number of load cycles, and time is observed on all components subjected to complex conditions. These complex conditions introduce uncertainties; hence, the actual factor of safety margin remains unknown. In the deterministic methodology, the contingency of failure is discounted; hence, there is a use of a high factor of safety. It may be most useful in situations where the design structures are simple. The probabilistic method is concerned with the probability of non-failure performance of structures or machine elements. It is much more useful in situations where the design is characterized by complex geometry, possibility of catastrophic failure, sensitive loads and material properties. Also included: Comparative Study of the use of AGMA Geometry Factors and Probabilistic Design Methodology in the Design of Compact Spur Gear Set.

A Study of Fixed-Order Mixed Norm Designs for a Benchmark Problem in Structural Control

NASA Technical Reports Server (NTRS)

Whorton, Mark S.; Calise, Anthony J.; Hsu, C. C.

1998-01-01

This study investigates the use of H2, p-synthesis, and mixed H2/mu methods to construct full-order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodelled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full-order compensators that are robust to both unmodelled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H, design performance levels while providing the same levels of robust stability as the u designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H, designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

Tradeoff methods in multiobjective insensitive design of airplane control systems

NASA Technical Reports Server (NTRS)

Schy, A. A.; Giesy, D. P.

1984-01-01

The latest results of an ongoing study of computer-aided design of airplane control systems are given. Constrained minimization algorithms are used, with the design objectives in the constraint vector. The concept of Pareto optimiality is briefly reviewed. It is shown how an experienced designer can use it to find designs which are well-balanced in all objectives. Then the problem of finding designs which are insensitive to uncertainty in system parameters are discussed, introducing a probabilistic vector definition of sensitivity which is consistent with the deterministic Pareto optimal problem. Insensitivity is important in any practical design, but it is particularly important in the design of feedback control systems, since it is considered to be the most important distinctive property of feedback control. Methods of tradeoff between deterministic and stochastic-insensitive (SI) design are described, and tradeoff design results are presented for the example of the a Shuttle lateral stability augmentation system. This example is used because careful studies have been made of the uncertainty in Shuttle aerodynamics. Finally, since accurate statistics of uncertain parameters are usually not available, the effects of crude statistical models on SI designs are examined.

Improved design of special boundary elements for T-shaped reinforced concrete walls

NASA Astrophysics Data System (ADS)

Ji, Xiaodong; Liu, Dan; Qian, Jiaru

2017-01-01

This study examines the design provisions of the Chinese GB 50011-2010 code for seismic design of buildings for the special boundary elements of T-shaped reinforced concrete walls and proposes an improved design method. Comparison of the design provisions of the GB 50011-2010 code and those of the American code ACI 318-14 indicates a possible deficiency in the T-shaped wall design provisions in GB 50011-2010. A case study of a typical T-shaped wall designed in accordance with GB 50011-2010 also indicates the insufficient extent of the boundary element at the non-flange end and overly conservative design of the flange end boundary element. Improved designs for special boundary elements of T-shaped walls are developed using a displacement-based method. The proposed design formulas produce a longer boundary element at the non-flange end and a shorter boundary element at the flange end, relative to those of the GB 50011-2010 provisions. Extensive numerical analysis indicates that T-shaped walls designed using the proposed formulas develop inelastic drift of 0.01 for both cases of the flange in compression and in tension.

A global parallel model based design of experiments method to minimize model output uncertainty.

PubMed

Bazil, Jason N; Buzzard, Gregory T; Rundell, Ann E

2012-03-01

Model-based experiment design specifies the data to be collected that will most effectively characterize the biological system under study. Existing model-based design of experiment algorithms have primarily relied on Fisher Information Matrix-based methods to choose the best experiment in a sequential manner. However, these are largely local methods that require an initial estimate of the parameter values, which are often highly uncertain, particularly when data is limited. In this paper, we provide an approach to specify an informative sequence of multiple design points (parallel design) that will constrain the dynamical uncertainty of the biological system responses to within experimentally detectable limits as specified by the estimated experimental noise. The method is based upon computationally efficient sparse grids and requires only a bounded uncertain parameter space; it does not rely upon initial parameter estimates. The design sequence emerges through the use of scenario trees with experimental design points chosen to minimize the uncertainty in the predicted dynamics of the measurable responses of the system. The algorithm was illustrated herein using a T cell activation model for three problems that ranged in dimension from 2D to 19D. The results demonstrate that it is possible to extract useful information from a mathematical model where traditional model-based design of experiments approaches most certainly fail. The experiments designed via this method fully constrain the model output dynamics to within experimentally resolvable limits. The method is effective for highly uncertain biological systems characterized by deterministic mathematical models with limited data sets. Also, it is highly modular and can be modified to include a variety of methodologies such as input design and model discrimination.

Enhanced teaching and student learning through a simulator-based course in chemical unit operations design

NASA Astrophysics Data System (ADS)

Ghasem, Nayef

2016-07-01

This paper illustrates a teaching technique used in computer applications in chemical engineering employed for designing various unit operation processes, where the students learn about unit operations by designing them. The aim of the course is not to teach design, but rather to teach the fundamentals and the function of unit operation processes through simulators. A case study presenting the teaching method was evaluated using student surveys and faculty assessments, which were designed to measure the quality and effectiveness of the teaching method. The results of the questionnaire conclusively demonstrate that this method is an extremely efficient way of teaching a simulator-based course. In addition to that, this teaching method can easily be generalised and used in other courses. A student's final mark is determined by a combination of in-class assessments conducted based on cooperative and peer learning, progress tests and a final exam. Results revealed that peer learning can improve the overall quality of student learning and enhance student understanding.

Pareto Design of State Feedback Tracking Control of a Biped Robot via Multiobjective PSO in Comparison with Sigma Method and Genetic Algorithms: Modified NSGAII and MATLAB's Toolbox

PubMed Central

Mahmoodabadi, M. J.; Taherkhorsandi, M.; Bagheri, A.

2014-01-01

An optimal robust state feedback tracking controller is introduced to control a biped robot. In the literature, the parameters of the controller are usually determined by a tedious trial and error process. To eliminate this process and design the parameters of the proposed controller, the multiobjective evolutionary algorithms, that is, the proposed method, modified NSGAII, Sigma method, and MATLAB's Toolbox MOGA, are employed in this study. Among the used evolutionary optimization algorithms to design the controller for biped robots, the proposed method operates better in the aspect of designing the controller since it provides ample opportunities for designers to choose the most appropriate point based upon the design criteria. Three points are chosen from the nondominated solutions of the obtained Pareto front based on two conflicting objective functions, that is, the normalized summation of angle errors and normalized summation of control effort. Obtained results elucidate the efficiency of the proposed controller in order to control a biped robot. PMID:24616619

40 CFR 21.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., architectural, legal, fiscal, or economic investigations or studies; surveys, designs, plans, writings, drawings... one or more applicable standards. This can be determined with reference to design specifications..., alterations, or methods of operation the design specifications of which will provide a measure of treatment or...

40 CFR 21.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., architectural, legal, fiscal, or economic investigations or studies; surveys, designs, plans, writings, drawings... one or more applicable standards. This can be determined with reference to design specifications..., alterations, or methods of operation the design specifications of which will provide a measure of treatment or...

40 CFR 21.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., architectural, legal, fiscal, or economic investigations or studies; surveys, designs, plans, writings, drawings... one or more applicable standards. This can be determined with reference to design specifications..., alterations, or methods of operation the design specifications of which will provide a measure of treatment or...

40 CFR 21.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., architectural, legal, fiscal, or economic investigations or studies; surveys, designs, plans, writings, drawings... one or more applicable standards. This can be determined with reference to design specifications..., alterations, or methods of operation the design specifications of which will provide a measure of treatment or...

40 CFR 21.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., architectural, legal, fiscal, or economic investigations or studies; surveys, designs, plans, writings, drawings... one or more applicable standards. This can be determined with reference to design specifications..., alterations, or methods of operation the design specifications of which will provide a measure of treatment or...

An Evolution-Based Approach to De Novo Protein Design and Case Study on Mycobacterium tuberculosis

PubMed Central

Brender, Jeffrey R.; Czajka, Jeff; Marsh, David; Gray, Felicia; Cierpicki, Tomasz; Zhang, Yang

2013-01-01

Computational protein design is a reverse procedure of protein folding and structure prediction, where constructing structures from evolutionarily related proteins has been demonstrated to be the most reliable method for protein 3-dimensional structure prediction. Following this spirit, we developed a novel method to design new protein sequences based on evolutionarily related protein families. For a given target structure, a set of proteins having similar fold are identified from the PDB library by structural alignments. A structural profile is then constructed from the protein templates and used to guide the conformational search of amino acid sequence space, where physicochemical packing is accommodated by single-sequence based solvation, torsion angle, and secondary structure predictions. The method was tested on a computational folding experiment based on a large set of 87 protein structures covering different fold classes, which showed that the evolution-based design significantly enhances the foldability and biological functionality of the designed sequences compared to the traditional physics-based force field methods. Without using homologous proteins, the designed sequences can be folded with an average root-mean-square-deviation of 2.1 Å to the target. As a case study, the method is extended to redesign all 243 structurally resolved proteins in the pathogenic bacteria Mycobacterium tuberculosis, which is the second leading cause of death from infectious disease. On a smaller scale, five sequences were randomly selected from the design pool and subjected to experimental validation. The results showed that all the designed proteins are soluble with distinct secondary structure and three have well ordered tertiary structure, as demonstrated by circular dichroism and NMR spectroscopy. Together, these results demonstrate a new avenue in computational protein design that uses knowledge of evolutionary conservation from protein structural families to engineer new protein molecules of improved fold stability and biological functionality. PMID:24204234

Study design and implementation for population pharmacokinetics of Chinese medicine: An expert consensus.

PubMed

Jiang, Jun-jie; Zhang, Wen; Xie, Yan-ming; Wang, Jian-nong; He, Fu-yuan; Xiong, Xin

2016-02-01

Although many population pharmacokinetics (PPK) researches have been conducted on chemical drugs, few have been in the field of Chinese medicine (CM). Each ingredient in CMs possesses different pharmacokinetic characteristics, therefore, it is important to develop methods of PPK studies on them to identify the differences in CM drug safety and efficacy among the population subgroups and to conduct quantitative studies on the determinants of CM drug concentrations. To develop an expert consensus on study design and implementation for PPK of CM, in August 2013, 6 experts in the field of PPK, CMs pharmacology, and statistics discussed problems on the PPK research protocol of CMs, and a consensus was reached. The medicines with toxicity and narrow therapeutic windows and with wide range of target population or with frequent adverse reactions were selected. The compositions with definite therapeutic effects were selected as indices, and specific time points and sample sizes were designed according to standard PPK design methods. Target components were tested through various chromatography methods. Total quantity statistical moment analysis was used to estimate PPK parameters of each component and PPK models reflecting the trend of CMs (which assists in reasonable adjustments on clinical dosage). This consensus specifies the study design and implementation process of PPK. It provides guidance for the following: post-marketing clinical studies, in vivo investigations related to the metabolism in different populations, and development and clinical adjustment of dosages of CMs.

The Legacy of Florence Nightingale's Environmental Theory: Nursing Research Focusing on the Impact of Healthcare Environments.

PubMed

Zborowsky, Terri

2014-01-01

The purpose of this paper is to explore nursing research that is focused on the impact of healthcare environments and that has resonance with the aspects of Florence Nightingale's environmental theory. Nurses have a unique ability to apply their observational skills to understand the role of the designed environment to enable healing in their patients. This affords nurses the opportunity to engage in research studies that have immediate impact on the act of nursing. Descriptive statistics were performed on 67 healthcare design-related research articles from 25 nursing journals to discover the topical areas of interest of nursing research today. Data were also analyzed to reveal the research designs, research methods, and research settings. These data are part of an ongoing study. Descriptive statistics reveal that topics and settings most frequently cited are in keeping with the current healthcare foci of patient care quality and safety in acute and intensive care environments. Research designs and methods most frequently cited are in keeping with the early progression of a knowledge area. A few assertions can be made as a result of this study. First, education is important to continue the knowledge development in this area. Second, multiple method research studies should continue to be considered as important to healthcare research. Finally, bedside nurses are in the best position possible to begin to help us all, through research, understand how the design environment impacts patients during the act of nursing. Evidence-based design, literature review, nursing.

Core Professionalism Education in Surgery: A Systematic Review.

PubMed

Sarıoğlu Büke, Akile; Karabilgin Öztürkçü, Özlem Sürel; Yılmaz, Yusuf; Sayek, İskender

2018-03-15

Professionalism education is one of the major elements of surgical residency education. To evaluate the studies on core professionalism education programs in surgical professionalism education. Systematic review. This systematic literature review was performed to analyze core professionalism programs for surgical residency education published in English with at least three of the following features: program developmental model/instructional design method, aims and competencies, methods of teaching, methods of assessment, and program evaluation model or method. A total of 27083 articles were retrieved using EBSCOHOST, PubMed, Science Direct, Web of Science, and manual search. Eight articles met the selection criteria. The instructional design method was presented in only one article, which described the Analysis, Design, Development, Implementation, and Evaluation model. Six articles were based on the Accreditation Council for Graduate Medical Education criterion, although there was significant variability in content. The most common teaching method was role modeling with scenario- and case-based learning. A wide range of assessment methods for evaluating professionalism education were reported. The Kirkpatrick model was reported in one article as a method for program evaluation. It is suggested that for a core surgical professionalism education program, developmental/instructional design model, aims and competencies, content, teaching methods, assessment methods, and program evaluation methods/models should be well defined, and the content should be comparable.

Evaluation of Psychological Hardiness and Coping Style as Risk/Resilience Factors for Health Risk Behaviour

DTIC Science & Technology

2011-04-01

205 RESEARCH DESIGN & METHODS Objective/Hypothesis: The objective of the study is to evaluate the utility of a short hardiness-resilience...problems. Study Design & Methods : This research will evaluate the utility of hardiness, as measured by the DRS-15R, as a screening tool for...may take a toll on defense workers. This research points the way to new approaches for early identification of military workers at risk for stress

The state of the art and future opportunities for using longitudinal n-of-1 methods in health behaviour research: a systematic literature overview.

PubMed

McDonald, Suzanne; Quinn, Francis; Vieira, Rute; O'Brien, Nicola; White, Martin; Johnston, Derek W; Sniehotta, Falko F

2017-12-01

n-of-1 studies test hypotheses within individuals based on repeated measurement of variables within the individual over time. Intra-individual effects may differ from those found in between-participant studies. Using examples from a systematic review of n-of-1 studies in health behaviour research, this article provides a state of the art overview of the use of n-of-1 methods, organised according to key methodological considerations related to n-of-1 design and analysis, and describes future challenges and opportunities. A comprehensive search strategy (PROSPERO:CRD42014007258) was used to identify articles published between 2000 and 2016, reporting observational or interventional n-of-1 studies with health behaviour outcomes. Thirty-nine articles were identified which reported on n-of-1 observational designs and a range of n-of-1 interventional designs, including AB, ABA, ABABA, alternating treatments, n-of-1 randomised controlled trial, multiple baseline and changing criterion designs. Behaviours measured included treatment adherence, physical activity, drug/alcohol use, sleep, smoking and eating behaviour. Descriptive, visual or statistical analyses were used. We identify scope and opportunities for using n-of-1 methods to answer key questions in health behaviour research. n-of-1 methods provide the tools needed to help advance theoretical knowledge and personalise/tailor health behaviour interventions to individuals.

Does classroom-based Crew Resource Management training improve patient safety culture? A systematic review

PubMed Central

de Bruijne, Martine C; Zwijnenberg, Nicolien C; Jansma, Elise P; van Dyck, Cathy; Wagner, Cordula

2014-01-01

Aim: To evaluate the evidence of the effectiveness of classroom-based Crew Resource Management training on safety culture by a systematic review of literature. Methods: Studies were identified in PubMed, Cochrane Library, PsycINFO, and Educational Resources Information Center up to 19 December 2012. The Methods Guide for Comparative Effectiveness Reviews was used to assess the risk of bias in the individual studies. Results: In total, 22 manuscripts were included for review. Training settings, study designs, and evaluation methods varied widely. Most studies reporting only a selection of culture dimensions found mainly positive results, whereas studies reporting all safety culture dimensions of the particular survey found mixed results. On average, studies were at moderate risk of bias. Conclusion: Evidence of the effectiveness of Crew Resource Management training in health care on safety culture is scarce and the validity of most studies is limited. The results underline the necessity of more valid study designs, preferably using triangulation methods. PMID:26770720

How and Why of User Studies: RLG's RedLightGreen as a Case Study

ERIC Educational Resources Information Center

Proffitt, Merrilee

2006-01-01

This article documents a lifecycle approach to employing user-centered design, covering both qualitative and quantitative data gathering methods in support of using this approach for product design, usability testing, and market research. The author provides specific case studies of usability studies, focus groups, interviews, ethnographic…

The Uses of Time for Teaching and Learning. Volume III: Research Design and Method. Studies of Education Reform.

ERIC Educational Resources Information Center

Policy Studies Associates, Inc., Washington, DC.

This report describes the research design of a study that identified and evaluated a collection of reforms designed to enhance learning by altering the amount of and/or the quality of time devoted to learning. The study focused on the quantity and quality of time that teachers and students spent in school and, to a lesser extent, students'…

Experimental design and quantitative analysis of microbial community multiomics.

PubMed

Mallick, Himel; Ma, Siyuan; Franzosa, Eric A; Vatanen, Tommi; Morgan, Xochitl C; Huttenhower, Curtis

2017-11-30

Studies of the microbiome have become increasingly sophisticated, and multiple sequence-based, molecular methods as well as culture-based methods exist for population-scale microbiome profiles. To link the resulting host and microbial data types to human health, several experimental design considerations, data analysis challenges, and statistical epidemiological approaches must be addressed. Here, we survey current best practices for experimental design in microbiome molecular epidemiology, including technologies for generating, analyzing, and integrating microbiome multiomics data. We highlight studies that have identified molecular bioactives that influence human health, and we suggest steps for scaling translational microbiome research to high-throughput target discovery across large populations.

Reducing Physical Risk Factors in Construction Work Through a Participatory Intervention: Protocol for a Mixed-Methods Process Evaluation.

PubMed

Ajslev, Jeppe; Brandt, Mikkel; Møller, Jeppe Lykke; Skals, Sebastian; Vinstrup, Jonas; Jakobsen, Markus Due; Sundstrup, Emil; Madeleine, Pascal; Andersen, Lars Louis

2016-05-26

Previous research has shown that reducing physical workload among workers in the construction industry is complicated. In order to address this issue, we developed a process evaluation in a formative mixed-methods design, drawing on existing knowledge of the potential barriers for implementation. We present the design of a mixed-methods process evaluation of the organizational, social, and subjective practices that play roles in the intervention study, integrating technical measurements to detect excessive physical exertion measured with electromyography and accelerometers, video documentation of working tasks, and a 3-phased workshop program. The evaluation is designed in an adapted process evaluation framework, addressing recruitment, reach, fidelity, satisfaction, intervention delivery, intervention received, and context of the intervention companies. Observational studies, interviews, and questionnaires among 80 construction workers organized in 20 work gangs, as well as health and safety staff, contribute to the creation of knowledge about these phenomena. At the time of publication, the process of participant recruitment is underway. Intervention studies are challenging to conduct and evaluate in the construction industry, often because of narrow time frames and ever-changing contexts. The mixed-methods design presents opportunities for obtaining detailed knowledge of the practices intra-acting with the intervention, while offering the opportunity to customize parts of the intervention.

Using Single-Case Design and Personalized Behavior Change Projects to Teach Research Methods

ERIC Educational Resources Information Center

Morgan, David L.

2009-01-01

Students in research methods courses, especially those taught in an intense format, might be hard pressed to actually conduct research studies due to logistics and time constraints. I describe the use of single-case research design and a personalized behavior project as an alternative research project for students in an undergraduate psychology…

Plant disease severity assessment - How rater bias, assessment method and experimental design affect hypothesis testing and resource use efficiency

USDA-ARS?s Scientific Manuscript database

The impact of rater bias and assessment method on hypothesis testing was studied for different experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed ‘balanced’, and those ...

Using an Iterative Mixed-Methods Research Design to Investigate Schools Facing Exceptionally Challenging Circumstances within Trinidad and Tobago

ERIC Educational Resources Information Center

De Lisle, Jerome; Seunarinesingh, Krishna; Mohammed, Rhoda; Lee-Piggott, Rinnelle

2017-01-01

In this study, methodology and theory were linked to explicate the nature of education practice within schools facing exceptionally challenging circumstances (SFECC) in Trinidad and Tobago. The research design was an iterative quan>QUAL-quan>qual multi-method research programme, consisting of 3 independent projects linked together by overall…

Design in Context: A Conceptual Framework for the Study of Computer Software in Higher Education.

ERIC Educational Resources Information Center

Kozma, Robert B.; Bangert-Drowns, Robert L.

The conceptual groundwork needed to examine the impact of technology, primarily microcomputers, on student learning is presented. Medium, method, and context are tied with a science of design. In section I, research on technology in higher education is reviewed, medium and method are defined, and interaction with context is discussed. Taxonomies…

Application of Grey Relational Analysis to Decision-Making during Product Development

ERIC Educational Resources Information Center

Hsiao, Shih-Wen; Lin, Hsin-Hung; Ko, Ya-Chuan

2017-01-01

A multi-attribute decision-making (MADM) approach was proposed in this study as a prediction method that differs from the conventional production and design methods for a product. When a client has different dimensional requirements, this approach can quickly provide a company with design decisions for each product. The production factors of a…

Economic Education in the Social Studies Methods Course. A 12-Hour Instructional Module for Elementary Methods Professors.

ERIC Educational Resources Information Center

Williams, Elmer; Dalton, Don

This 12-hour module of instruction is designed to help undergraduates in social studies methods courses integrate economics education into the elementary school social studies curriculum. The major purposes of the module are to (1) demonstrate how economics concepts can be integrated into social studies instruction, (2) reinforce or extend teacher…

Do Bayesian adaptive trials offer advantages for comparative effectiveness research? Protocol for the RE-ADAPT study

PubMed Central

Luce, Bryan R; Broglio, Kristine R; Ishak, K Jack; Mullins, C Daniel; Vanness, David J; Fleurence, Rachael; Saunders, Elijah; Davis, Barry R

2013-01-01

Background Randomized clinical trials, particularly for comparative effectiveness research (CER), are frequently criticized for being overly restrictive or untimely for health-care decision making. Purpose Our prospectively designed REsearch in ADAptive methods for Pragmatic Trials (RE-ADAPT) study is a ‘proof of concept’ to stimulate investment in Bayesian adaptive designs for future CER trials. Methods We will assess whether Bayesian adaptive designs offer potential efficiencies in CER by simulating a re-execution of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study using actual data from ALLHAT. Results We prospectively define seven alternate designs consisting of various combinations of arm dropping, adaptive randomization, and early stopping and describe how these designs will be compared to the original ALLHAT design. We identify the one particular design that would have been executed, which incorporates early stopping and information-based adaptive randomization. Limitations While the simulation realistically emulates patient enrollment, interim analyses, and adaptive changes to design, it cannot incorporate key features like the involvement of data monitoring committee in making decisions about adaptive changes. Conclusion This article describes our analytic approach for RE-ADAPT. The next stage of the project is to conduct the re-execution analyses using the seven prespecified designs and the original ALLHAT data. PMID:23983160

Oasis Connections: Results from an Evaluation Study

ERIC Educational Resources Information Center

Czaja, Sara J.; Lee, Chin Chin; Branham, Janice; Remis, Peggy

2012-01-01

Purpose of the Study: The objectives of this study were to evaluate a community-based basic computer and Internet training program designed for older adults, provide recommendations for program refinement, and gather preliminary information on program sustainability. Design and Methods: The program was developed by the OASIS Institute, a nonprofit…

Shared-use bus priority lanes on city streets : case studies in design and management [research brief].

DOT National Transportation Integrated Search

2012-04-01

This study examines the design and operations of bus lanes in major congested urban centers. It focuses on shared-use bus lanes that operate in mixed traffic conditions. : Study Methods : The key questions addressed are: : 1. How do the many public a...

Discriminating between stabilizing and destabilizing protein design mutations via recombination and simulation.

PubMed

Johnson, Lucas B; Gintner, Lucas P; Park, Sehoo; Snow, Christopher D

2015-08-01

Accuracy of current computational protein design (CPD) methods is limited by inherent approximations in energy potentials and sampling. These limitations are often used to qualitatively explain design failures; however, relatively few studies provide specific examples or quantitative details that can be used to improve future CPD methods. Expanding the design method to include a library of sequences provides data that is well suited for discriminating between stabilizing and destabilizing design elements. Using thermophilic endoglucanase E1 from Acidothermus cellulolyticus as a model enzyme, we computationally designed a sequence with 60 mutations. The design sequence was rationally divided into structural blocks and recombined with the wild-type sequence. Resulting chimeras were assessed for activity and thermostability. Surprisingly, unlike previous chimera libraries, regression analysis based on one- and two-body effects was not sufficient for predicting chimera stability. Analysis of molecular dynamics simulations proved helpful in distinguishing stabilizing and destabilizing mutations. Reverting to the wild-type amino acid at destabilized sites partially regained design stability, and introducing predicted stabilizing mutations in wild-type E1 significantly enhanced thermostability. The ability to isolate stabilizing and destabilizing elements in computational design offers an opportunity to interpret previous design failures and improve future CPD methods. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Study on the supply chain of an enterprise based on axiomatic design

NASA Astrophysics Data System (ADS)

Fan, Shu-hai; Lin, Chao-qun; Ji, Chun; Zhou, Ce; Chen, Peng

2018-06-01

This paper first expounds the basic theoretical knowledge of axiomatic design, and then designs and improves the enterprise supply chain through two design axioms (axiom of independence and information axiom). In the axiomatic design of the axiom of independence, the user needs to determine the needs and problems to be solved, to determine the top total goals, the total goal decomposition, and to determine their own design equations. In the application of information axiom, the concept of cloud is used to quantify the amount of information, and the two schemes are evaluated and compared. Finally, through axiomatic design, we can get the best solution for the improvement of supply chain design. Axiomatic design is a generic, systematic and sophisticated approach to design that addresses the needs of different customers. Using this method to improve the level of supply chain management is creative. As a mature method, it will make the process efficient and convenient.

Receiver operating characteristic (ROC) curves: review of methods with applications in diagnostic medicine

NASA Astrophysics Data System (ADS)

Obuchowski, Nancy A.; Bullen, Jennifer A.

2018-04-01

Receiver operating characteristic (ROC) analysis is a tool used to describe the discrimination accuracy of a diagnostic test or prediction model. While sensitivity and specificity are the basic metrics of accuracy, they have many limitations when characterizing test accuracy, particularly when comparing the accuracies of competing tests. In this article we review the basic study design features of ROC studies, illustrate sample size calculations, present statistical methods for measuring and comparing accuracy, and highlight commonly used ROC software. We include descriptions of multi-reader ROC study design and analysis, address frequently seen problems of verification and location bias, discuss clustered data, and provide strategies for testing endpoints in ROC studies. The methods are illustrated with a study of transmission ultrasound for diagnosing breast lesions.

Relations between Prejudice, Cultural Intelligence and Level of Entrepreneurship: A Study of School Principals

ERIC Educational Resources Information Center

Baltaci, Ali

2017-01-01

The aim of this study is to determine the mediating role of prejudice in the relationship between the cultural intelligence of school principals and the level of entrepreneurship. The design of this study was classified as correlational survey research. This study was designed by quantitative research method. The universe of this study constitutes…

Combining qualitative and quantitative research within mixed method research designs: a methodological review.

PubMed

Östlund, Ulrika; Kidd, Lisa; Wengström, Yvonne; Rowa-Dewar, Neneh

2011-03-01

It has been argued that mixed methods research can be useful in nursing and health science because of the complexity of the phenomena studied. However, the integration of qualitative and quantitative approaches continues to be one of much debate and there is a need for a rigorous framework for designing and interpreting mixed methods research. This paper explores the analytical approaches (i.e. parallel, concurrent or sequential) used in mixed methods studies within healthcare and exemplifies the use of triangulation as a methodological metaphor for drawing inferences from qualitative and quantitative findings originating from such analyses. This review of the literature used systematic principles in searching CINAHL, Medline and PsycINFO for healthcare research studies which employed a mixed methods approach and were published in the English language between January 1999 and September 2009. In total, 168 studies were included in the results. Most studies originated in the United States of America (USA), the United Kingdom (UK) and Canada. The analytic approach most widely used was parallel data analysis. A number of studies used sequential data analysis; far fewer studies employed concurrent data analysis. Very few of these studies clearly articulated the purpose for using a mixed methods design. The use of the methodological metaphor of triangulation on convergent, complementary, and divergent results from mixed methods studies is exemplified and an example of developing theory from such data is provided. A trend for conducting parallel data analysis on quantitative and qualitative data in mixed methods healthcare research has been identified in the studies included in this review. Using triangulation as a methodological metaphor can facilitate the integration of qualitative and quantitative findings, help researchers to clarify their theoretical propositions and the basis of their results. This can offer a better understanding of the links between theory and empirical findings, challenge theoretical assumptions and develop new theory. Copyright © 2010 Elsevier Ltd. All rights reserved.

Preliminary Structural Sensitivity Study of Hypersonic Inflatable Aerodynamic Decelerator Using Probabilistic Methods

NASA Technical Reports Server (NTRS)

Lyle, Karen H.

2014-01-01

Acceptance of new spacecraft structural architectures and concepts requires validated design methods to minimize the expense involved with technology validation via flighttesting. This paper explores the implementation of probabilistic methods in the sensitivity analysis of the structural response of a Hypersonic Inflatable Aerodynamic Decelerator (HIAD). HIAD architectures are attractive for spacecraft deceleration because they are lightweight, store compactly, and utilize the atmosphere to decelerate a spacecraft during re-entry. However, designers are hesitant to include these inflatable approaches for large payloads or spacecraft because of the lack of flight validation. In the example presented here, the structural parameters of an existing HIAD model have been varied to illustrate the design approach utilizing uncertainty-based methods. Surrogate models have been used to reduce computational expense several orders of magnitude. The suitability of the design is based on assessing variation in the resulting cone angle. The acceptable cone angle variation would rely on the aerodynamic requirements.

An Introduction to the BFS Method and Its Use to Model Binary NiAl Alloys

NASA Technical Reports Server (NTRS)

Bozzolo, Guillermo; Noebe, Ronald D.; Ferrante, J.; Amador, C.

1998-01-01

We introduce the Bozzolo-Ferrante-Smith (BFS) method for alloys as a computationally efficient tool for aiding in the process of alloy design. An intuitive description of the BFS method is provided, followed by a formal discussion of its implementation. The method is applied to the study of the defect structure of NiAl binary alloys. The groundwork is laid for a detailed progression to higher order NiAl-based alloys linking theoretical calculations and computer simulations based on the BFS method and experimental work validating each step of the alloy design process.

Analysis of neighborhood behavior in lead optimization and array design.

PubMed

Papadatos, George; Cooper, Anthony W J; Kadirkamanathan, Visakan; Macdonald, Simon J F; McLay, Iain M; Pickett, Stephen D; Pritchard, John M; Willett, Peter; Gillet, Valerie J

2009-02-01

Neighborhood behavior describes the extent to which small structural changes defined by a molecular descriptor are likely to lead to small property changes. This study evaluates two methods for the quantification of neighborhood behavior: the optimal diagonal method of Patterson et al. and the optimality criterion method of Horvath and Jeandenans. The methods are evaluated using twelve different types of fingerprint (both 2D and 3D) with screening data derived from several lead optimization projects at GlaxoSmithKline. The principal focus of the work is the design of chemical arrays during lead optimization, and the study hence considers not only biological activity but also important drug properties such as metabolic stability, permeability, and lipophilicity. Evidence is provided to suggest that the optimality criterion method may provide a better quantitative description of neighborhood behavior than the optimal diagonal method.

Flux control coefficients determined by inhibitor titration: the design and analysis of experiments to minimize errors.

PubMed Central

Small, J R

1993-01-01

This paper is a study into the effects of experimental error on the estimated values of flux control coefficients obtained using specific inhibitors. Two possible techniques for analysing the experimental data are compared: a simple extrapolation method (the so-called graph method) and a non-linear function fitting method. For these techniques, the sources of systematic errors are identified and the effects of systematic and random errors are quantified, using both statistical analysis and numerical computation. It is shown that the graph method is very sensitive to random errors and, under all conditions studied, that the fitting method, even under conditions where the assumptions underlying the fitted function do not hold, outperformed the graph method. Possible ways of designing experiments to minimize the effects of experimental errors are analysed and discussed. PMID:8257434

Participatory interaction design in user requirements specification in healthcare.

PubMed

Martikainen, Susanna; Ikävalko, Pauliina; Korpela, Mikko

2010-01-01

Healthcare information systems are accused of poor usability even in the popular media in Finland. Doctors especially have been very critical and actively expressed their opinions in public. User involvement and user-centered design methods are seen as the key solution to usability problems. In this paper we describe a research case where participatory methods were experimented within healthcare information systems development in medicinal care in a hospital. The study was part of a larger research project on Activity-driven Information Systems Development in healthcare. The study started by finding out about and modeling the present state of medicinal care in the hospital. After that it was important to define and model the goal state. The goal state, facilitated by the would-be software package, was modeled with the help of user interface drawings as one way of prototyping. Traditional usability methods were extended during the study. According to the health professionals' feedback, the use of participatory and user-centered interaction design methods, particularly user interface drawings enabled them to describe their requirements and create common understanding with the system developers.

Experimental Design for Multi-drug Combination Studies Using Signaling Networks

PubMed Central

Huang, Hengzhen; Fang, Hong-Bin; Tan, Ming T.

2017-01-01

Summary Combinations of multiple drugs are an important approach to maximize the chance for therapeutic success by inhibiting multiple pathways/targets. Analytic methods for studying drug combinations have received increasing attention because major advances in biomedical research have made available large number of potential agents for testing. The preclinical experiment on multi-drug combinations plays a key role in (especially cancer) drug development because of the complex nature of the disease, the need to reduce development time and costs. Despite recent progresses in statistical methods for assessing drug interaction, there is an acute lack of methods for designing experiments on multi-drug combinations. The number of combinations grows exponentially with the number of drugs and dose-levels and it quickly precludes laboratory testing. Utilizing experimental dose-response data of single drugs and a few combinations along with pathway/network information to obtain an estimate of the functional structure of the dose-response relationship in silico, we propose an optimal design that allows exploration of the dose-effect surface with the smallest possible sample size in this paper. The simulation studies show our proposed methods perform well. PMID:28960231

Qualitative research methods for medical educators.

PubMed

Hanson, Janice L; Balmer, Dorene F; Giardino, Angelo P

2011-01-01

This paper provides a primer for qualitative research in medical education. Our aim is to equip readers with a basic understanding of qualitative research and prepare them to judge the goodness of fit between qualitative research and their own research questions. We provide an overview of the reasons for choosing a qualitative research approach and potential benefits of using these methods for systematic investigation. We discuss developing qualitative research questions, grounding research in a philosophical framework, and applying rigorous methods of data collection, sampling, and analysis. We also address methods to establish the trustworthiness of a qualitative study and introduce the reader to ethical concerns that warrant special attention when planning qualitative research. We conclude with a worksheet that readers may use for designing a qualitative study. Medical educators ask many questions that carefully designed qualitative research would address effectively. Careful attention to the design of qualitative studies will help to ensure credible answers that will illuminate many of the issues, challenges, and quandaries that arise while doing the work of medical education. Copyright © 2011 Academic Pediatric Association. All rights reserved.

The design and fabrication of two portal vein flow phantoms by different methods

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

Yunker, Bryan E., E-mail: bryan.yunker@ucdenver.edu; Lanning, Craig J.; Shandas, Robin

2014-02-15

Purpose: This study outlines the design and fabrication techniques for two portal vein flow phantoms. Methods: A materials study was performed as a precursor to this phantom fabrication effort and the desired material properties are restated for continuity. A three-dimensional portal vein pattern was created from the Visual Human database. The portal vein pattern was used to fabricate two flow phantoms by different methods with identical interior surface geometry using computer aided design software tools and rapid prototyping techniques. One portal flow phantom was fabricated within a solid block of clear silicone for use on a table with Ultrasound ormore » within medical imaging systems such as MRI, CT, PET, or SPECT. The other portal flow phantom was fabricated as a thin walled tubular latex structure for use in water tanks with Ultrasound imaging. Both phantoms were evaluated for usability and durability. Results: Both phantoms were fabricated successfully and passed durability criteria for flow testing in the next project phase. Conclusions: The fabrication methods and materials employed for the study yielded durable portal vein phantoms.« less

Economic Education in the Social Studies Methods Course. A 12-Hour Instructional Module for Secondary Methods Professors.

ERIC Educational Resources Information Center

Williams, Elmer; Dalton, Don

This 12-hour module of instruction is designed to help undergraduates in social studies methods courses integrate economics education into the secondary school social studies curriculum. The major purposes of the module are to (1) reinforce or extend teacher education students' understanding of selected basic economic concepts, (2) develop an…

Quantitative imaging biomarkers: a review of statistical methods for technical performance assessment.

PubMed

Raunig, David L; McShane, Lisa M; Pennello, Gene; Gatsonis, Constantine; Carson, Paul L; Voyvodic, James T; Wahl, Richard L; Kurland, Brenda F; Schwarz, Adam J; Gönen, Mithat; Zahlmann, Gudrun; Kondratovich, Marina V; O'Donnell, Kevin; Petrick, Nicholas; Cole, Patricia E; Garra, Brian; Sullivan, Daniel C

2015-02-01

Technological developments and greater rigor in the quantitative measurement of biological features in medical images have given rise to an increased interest in using quantitative imaging biomarkers to measure changes in these features. Critical to the performance of a quantitative imaging biomarker in preclinical or clinical settings are three primary metrology areas of interest: measurement linearity and bias, repeatability, and the ability to consistently reproduce equivalent results when conditions change, as would be expected in any clinical trial. Unfortunately, performance studies to date differ greatly in designs, analysis method, and metrics used to assess a quantitative imaging biomarker for clinical use. It is therefore difficult or not possible to integrate results from different studies or to use reported results to design studies. The Radiological Society of North America and the Quantitative Imaging Biomarker Alliance with technical, radiological, and statistical experts developed a set of technical performance analysis methods, metrics, and study designs that provide terminology, metrics, and methods consistent with widely accepted metrological standards. This document provides a consistent framework for the conduct and evaluation of quantitative imaging biomarker performance studies so that results from multiple studies can be compared, contrasted, or combined. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Material Development to Raise Awareness of Using Smart Boards: An Example Design and Development Research

ERIC Educational Resources Information Center

Günaydin, Serpil; Karamete, Aysen

2016-01-01

This study aims to develop training material that will help raise awareness in prospective teachers regarding the benefits of using smart boards in the classroom. In this study, a Type 2 design and development research method (DDR) was used. The material was developed by applying phases of ADDIE--an instructional systems design model. The…

Power Analysis in Two-Level Unbalanced Designs

ERIC Educational Resources Information Center

Konstantopoulos, Spyros

2010-01-01

Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs…

Reading Students' Minds: Design Assessment in Distance Education

ERIC Educational Resources Information Center

Jones, Derek

2014-01-01

This paper considers the design of assessment for students of design according to behaviourist versus experiential pedagogical approaches, relating these to output-oriented as opposed to process-oriented assessment methods. It is part case study and part recognition of the importance of process in design education and how this might be applied in…

A novel design solution to the fraenal notch of maxillary dentures.

PubMed

White, J A P; Bond, I P; Jagger, D C

2013-09-01

This study investigates a novel design feature for the fraenal notch of maxillary dentures, using computational and experimental methods, and shows that its use could significantly increase the longevity of the prosthesis. A two-step process can be used to create the design feature with current denture base materials, but would be highly dependent on the individual skill of the dental technician. Therefore, an alternative form of manufacture, multi-material additive layer manufacture (or '3D printing'), has been proposed as a future method for the direct production of complete dentures with multi-material design features.

Enhancing Learning Outcomes through Evaluation of Serious Gaming: A Mixed Methods Study

ERIC Educational Resources Information Center

Douglas, Kerrie Anna

2012-01-01

This study compared the change in counseling student's self-efficacy and skill related to suicide assessment and intervention through the use of a novel intervention-oriented evaluation method, evaluation focused discussion groups, in an experimental embedded mixed methods design. An innovation counselor pedagogical tool, Suicide Risk Assessment…

The Problem With the Placement Study.

ERIC Educational Resources Information Center

Miner, Norris

This study compared the effectiveness and efficiency of two alternative methods for determining the status of graduates of Seminole Community College. The first method involved the identification of graduates, design and mailing of a questionnaire, and analysis of response data, as mandated by the state. The second method compared computer data…

A Mixed-Methods Longitudinal Evaluation of a One-Day Mental Health Wellness Intervention

ERIC Educational Resources Information Center

Doyle, Louise; de Vries, Jan; Higgins, Agnes; Keogh, Brian; McBennett, Padraig; O'Shea, Marié T.

2017-01-01

Objectives: This study evaluated the impact of a one-day mental health Wellness Workshop on participants' mental health and attitudes towards mental health. Design: Convergent, longitudinal mixed-methods approach. Setting: The study evaluated Wellness Workshops which took place throughout the Republic of Ireland. Method: Questionnaires measuring…

Statistical methods for efficient design of community surveys of response to noise: Random coefficients regression models

NASA Technical Reports Server (NTRS)

Tomberlin, T. J.

1985-01-01

Research studies of residents' responses to noise consist of interviews with samples of individuals who are drawn from a number of different compact study areas. The statistical techniques developed provide a basis for those sample design decisions. These techniques are suitable for a wide range of sample survey applications. A sample may consist of a random sample of residents selected from a sample of compact study areas, or in a more complex design, of a sample of residents selected from a sample of larger areas (e.g., cities). The techniques may be applied to estimates of the effects on annoyance of noise level, numbers of noise events, the time-of-day of the events, ambient noise levels, or other factors. Methods are provided for determining, in advance, how accurately these effects can be estimated for different sample sizes and study designs. Using a simple cost function, they also provide for optimum allocation of the sample across the stages of the design for estimating these effects. These techniques are developed via a regression model in which the regression coefficients are assumed to be random, with components of variance associated with the various stages of a multi-stage sample design.

Establishing a design procedure for buried steel-reinforced high-density polyethylene pipes : a field study, [technical summary].

DOT National Transportation Integrated Search

2015-11-01

Several national standards and specification have been developed for design, installation, : and materials for precast concrete pipe, corrugated metal pipe, and HDPE pipes. However, : no national accepted installation standard or design method is ava...

Efficient Testing Combining Design of Experiment and Learn-to-Fly Strategies

NASA Technical Reports Server (NTRS)

Murphy, Patrick C.; Brandon, Jay M.

2017-01-01

Rapid modeling and efficient testing methods are important in a number of aerospace applications. In this study efficient testing strategies were evaluated in a wind tunnel test environment and combined to suggest a promising approach for both ground-based and flight-based experiments. Benefits of using Design of Experiment techniques, well established in scientific, military, and manufacturing applications are evaluated in combination with newly developing methods for global nonlinear modeling. The nonlinear modeling methods, referred to as Learn-to-Fly methods, utilize fuzzy logic and multivariate orthogonal function techniques that have been successfully demonstrated in flight test. The blended approach presented has a focus on experiment design and identifies a sequential testing process with clearly defined completion metrics that produce increased testing efficiency.

Designing electronic module based on learning content development system in fostering students’ multi representation skills

NASA Astrophysics Data System (ADS)

Resita, I.; Ertikanto, C.

2018-05-01

This study aims to develop electronic module design based on Learning Content Development System (LCDS) to foster students’ multi representation skills in physics subject material. This study uses research and development method to the product design. This study involves 90 students and 6 physics teachers who were randomly chosen from 3 different Senior High Schools in Lampung Province. The data were collected by using questionnaires and analyzed by using quantitative descriptive method. Based on the data, 95% of the students only use one form of representation in solving physics problems. Representation which is tend to be used by students is symbolic representation. Students are considered to understand the concept of physics if they are able to change from one form to the other forms of representation. Product design of LCDS-based electronic module presents text, image, symbolic, video, and animation representation.

Non-destructive testing method for determining the solvent diffusion coefficient in the porous materials products

NASA Astrophysics Data System (ADS)

Belyaev, V. P.; Mishchenko, S. V.; Belyaev, P. S.

2018-01-01

Ensuring non-destructive testing of products in industry is an urgent task. Most of the modern methods for determining the diffusion coefficient in porous materials have been developed for bodies of a given configuration and size. This leads to the need for finished products destruction to make experimental samples from them. The purpose of this study is the development of a dynamic method that allows operatively determine the diffusion coefficient in finished products from porous materials without destroying them. The method is designed to investigate the solvents diffusion coefficient in building constructions from materials having a porous structure: brick, concrete and aerated concrete, gypsum, cement, gypsum or silicate solutions, gas silicate blocks, heat insulators, etc. A mathematical model of the method is constructed. The influence of the design and measuring device operating parameters on the method accuracy is studied. The application results of the developed method for structural porous products are presented.

The Rocket Equation Improvement under ICF Implosion Experiment

NASA Astrophysics Data System (ADS)

Wang, Yanbin; Zheng, Zhijian

2013-10-01

The ICF explosion process has been studied in details. The rocket equation has been improved in explosive process by introducing the pressure parameter of fuel. Some methods could be drawn by the improved rocket equation. And the methods could be used to improve ICF target design, driving pulse design and experimental design. The First is to increase ablation pressure. The second is to decrease pressure of fuel. The third is to use larger diameter of target sphere. And the forth is to a shorten driving pulse.

Proceedingsof the International Conference on Inverse Design Concepts and Optimization in Engineering Sciences (3rd) ICIDES-III Held in Washington, DC 23-25 October 1991

DTIC Science & Technology

1991-09-01

jet engine (even rocket engine ) rotating components. Examples have been presented for compressor and turbine profile designs. Both methods are...used for experimental studies on plasmatrons and gasdynamic stands in which the gas jets are created by special aviation and rocket engines . Similar... Aviation Institute, Bd. Pacli 220, 77538 Bucharest, ROMANIA 45 --’, Inverse Airfoil Design Procedure .Uging a Mliitigrid Navier-Stokes ,Method) J.B

Space qualified Nd:YAG laser (phase 1 - design)

NASA Technical Reports Server (NTRS)

Foster, J. D.; Kirk, R. F.

1971-01-01

Results of a design study and preliminary design of a space qualified Nd:YAG laser are presented. A theoretical model of the laser was developed to allow the evaluation of the effects of various parameters on its performance. Various pump lamps were evaluated and sum pumping was considered. Cooling requirements were examined and cooling methods such as radiation, cryogenic and conductive were analysed. Power outputs and efficiences of various configurations and the pump and laser lifetime are discussed. Also considered were modulation and modulating methods.

A Case Study in Design Thinking Applied Through Aviation Mission Support Tactical Advancements for the Next Generation (TANG)

DTIC Science & Technology

2017-12-01

This is an examination of the research, execution, and follow- on developments supporting the Design Thinking event explored through Case Study ...research, execution, and follow- on developments supporting the Design Thinking event explored through case study methods. Additionally, the lenses of...total there have been two Naval Postgraduate School (NPS) case study theses on U.S. Navy innovation events as well as other works examining the

Statistical Design Model (SDM) of satellite thermal control subsystem

NASA Astrophysics Data System (ADS)

Mirshams, Mehran; Zabihian, Ehsan; Aarabi Chamalishahi, Mahdi

2016-07-01

Satellites thermal control, is a satellite subsystem that its main task is keeping the satellite components at its own survival and activity temperatures. Ability of satellite thermal control plays a key role in satisfying satellite's operational requirements and designing this subsystem is a part of satellite design. In the other hand due to the lack of information provided by companies and designers still doesn't have a specific design process while it is one of the fundamental subsystems. The aim of this paper, is to identify and extract statistical design models of spacecraft thermal control subsystem by using SDM design method. This method analyses statistical data with a particular procedure. To implement SDM method, a complete database is required. Therefore, we first collect spacecraft data and create a database, and then we extract statistical graphs using Microsoft Excel, from which we further extract mathematical models. Inputs parameters of the method are mass, mission, and life time of the satellite. For this purpose at first thermal control subsystem has been introduced and hardware using in the this subsystem and its variants has been investigated. In the next part different statistical models has been mentioned and a brief compare will be between them. Finally, this paper particular statistical model is extracted from collected statistical data. Process of testing the accuracy and verifying the method use a case study. Which by the comparisons between the specifications of thermal control subsystem of a fabricated satellite and the analyses results, the methodology in this paper was proved to be effective. Key Words: Thermal control subsystem design, Statistical design model (SDM), Satellite conceptual design, Thermal hardware

A Computational/Experimental Study of Two Optimized Supersonic Transport Designs and the Reference H Baseline

NASA Technical Reports Server (NTRS)

Cliff, Susan E.; Baker, Timothy J.; Hicks, Raymond M.; Reuther, James J.

1999-01-01

Two supersonic transport configurations designed by use of non-linear aerodynamic optimization methods are compared with a linearly designed baseline configuration. One optimized configuration, designated Ames 7-04, was designed at NASA Ames Research Center using an Euler flow solver, and the other, designated Boeing W27, was designed at Boeing using a full-potential method. The two optimized configurations and the baseline were tested in the NASA Langley Unitary Plan Supersonic Wind Tunnel to evaluate the non-linear design optimization methodologies. In addition, the experimental results are compared with computational predictions for each of the three configurations from the Enter flow solver, AIRPLANE. The computational and experimental results both indicate moderate to substantial performance gains for the optimized configurations over the baseline configuration. The computed performance changes with and without diverters and nacelles were in excellent agreement with experiment for all three models. Comparisons of the computational and experimental cruise drag increments for the optimized configurations relative to the baseline show excellent agreement for the model designed by the Euler method, but poorer comparisons were found for the configuration designed by the full-potential code.

Aerothermodynamic shape optimization of hypersonic blunt bodies

NASA Astrophysics Data System (ADS)

Eyi, Sinan; Yumuşak, Mine

2015-07-01

The aim of this study is to develop a reliable and efficient design tool that can be used in hypersonic flows. The flow analysis is based on the axisymmetric Euler/Navier-Stokes and finite-rate chemical reaction equations. The equations are coupled simultaneously and solved implicitly using Newton's method. The Jacobian matrix is evaluated analytically. A gradient-based numerical optimization is used. The adjoint method is utilized for sensitivity calculations. The objective of the design is to generate a hypersonic blunt geometry that produces the minimum drag with low aerodynamic heating. Bezier curves are used for geometry parameterization. The performances of the design optimization method are demonstrated for different hypersonic flow conditions.

An analytic model for footprint dispersions and its application to mission design

NASA Technical Reports Server (NTRS)

Rao, J. R. Jagannatha; Chen, Yi-Chao

1992-01-01

This is the final report on our recent research activities that are complementary to those conducted by our colleagues, Professor Farrokh Mistree and students, in the context of the Taguchi method. We have studied the mathematical model that forms the basis of the Simulation and Optimization of Rocket Trajectories (SORT) program and developed an analytic method for determining mission reliability with a reduced number of flight simulations. This method can be incorporated in a design algorithm to mathematically optimize different performance measures of a mission, thus leading to a robust and easy-to-use methodology for mission planning and design.

Design standards for experimental and field studies to evaluate diagnostic accuracy of tests for infectious diseases in aquatic animals.

PubMed

Laurin, E; Thakur, K K; Gardner, I A; Hick, P; Moody, N J G; Crane, M S J; Ernst, I

2018-05-01

Design and reporting quality of diagnostic accuracy studies (DAS) are important metrics for assessing utility of tests used in animal and human health. Following standards for designing DAS will assist in appropriate test selection for specific testing purposes and minimize the risk of reporting biased sensitivity and specificity estimates. To examine the benefits of recommending standards, design information from published DAS literature was assessed for 10 finfish, seven mollusc, nine crustacean and two amphibian diseases listed in the 2017 OIE Manual of Diagnostic Tests for Aquatic Animals. Of the 56 DAS identified, 41 were based on field testing, eight on experimental challenge studies and seven on both. Also, we adapted human and terrestrial-animal standards and guidelines for DAS structure for use in aquatic animal diagnostic research. Through this process, we identified and addressed important metrics for consideration at the design phase: study purpose, targeted disease state, selection of appropriate samples and specimens, laboratory analytical methods, statistical methods and data interpretation. These recommended design standards for DAS are presented as a checklist including risk-of-failure points and actions to mitigate bias at each critical step. Adherence to standards when designing DAS will also facilitate future systematic review and meta-analyses of DAS research literature. © 2018 John Wiley & Sons Ltd.

Analysis of Combined Data from Heterogeneous Study Designs: A Methodological Proposal from the Patient Navigation Research program

PubMed Central

Roetzheim, Richard G.; Freund, Karen M.; Corle, Don K.; Murray, David M.; Snyder, Frederick R.; Kronman, Andrea C.; Jean-Pierre, Pascal; Raich, Peter C.; Holden, Alan E. C.; Darnell, Julie S.; Warren-Mears, Victoria; Patierno, Steven; Design, PNRP; Committee, Analysis

2013-01-01

Background The Patient Navigation Research Program (PNRP) is a cooperative effort of nine research projects, each employing its own unique study design. To evaluate projects such as PNRP, it is desirable to perform a pooled analysis to increase power relative to the individual projects. There is no agreed upon prospective methodology, however, for analyzing combined data arising from different study designs. Expert opinions were thus solicited from members of the PNRP Design and Analysis Committee Purpose To review possible methodologies for analyzing combined data arising from heterogeneous study designs. Methods The Design and Analysis Committee critically reviewed the pros and cons of five potential methods for analyzing combined PNRP project data. Conclusions were based on simple consensus. The five approaches reviewed included: 1) Analyzing and reporting each project separately, 2) Combining data from all projects and performing an individual-level analysis, 3) Pooling data from projects having similar study designs, 4) Analyzing pooled data using a prospective meta analytic technique, 5) Analyzing pooled data utilizing a novel simulated group randomized design. Results Methodologies varied in their ability to incorporate data from all PNRP projects, to appropriately account for differing study designs, and in their impact from differing project sample sizes. Limitations The conclusions reached were based on expert opinion and not derived from actual analyses performed. Conclusions The ability to analyze pooled data arising from differing study designs may provide pertinent information to inform programmatic, budgetary, and policy perspectives. Multi-site community-based research may not lend itself well to the more stringent explanatory and pragmatic standards of a randomized controlled trial design. Given our growing interest in community-based population research, the challenges inherent in the analysis of heterogeneous study design are likely to become more salient. Discussion of the analytic issues faced by the PNRP and the methodological approaches we considered may be of value to other prospective community-based research programs. PMID:22273587

Co-brand strategy of evaluation of visual images in furniture design: Jimmy S.P.A. and STRAUSS as examples

NASA Astrophysics Data System (ADS)

Chen, Tien-Li; Pan, Fang-Ming; Tsai, Jen-Hui

2013-03-01

This study aimed to investigate the correlation of the image associated by the design Co-Brand (Jimmy S.P.A. and STRAUSS) and the impression perceived by subject of viewers. Visual images were used to examine the merit of the evaluation. The best result is provided using an object as an appropriate evaluation method. There are a lot of factors which influence to evaluation of a design. This study is limited to distinguish the appearance from Jimmy's picture books transform furniture and so on. Co-Brand of Jimmy S.P.A. and STRAUSS is not easy because there are not from the same cultural, and industry background and applying different marketing strategy, it is a way to combine the two brands by designing, used questionnaire of SD (Semantic differential evaluation) evaluation method to test out the perception of viewers, the objective of this study is to investigate and appraised the Co-Brands use by of the image in furniture from patrons. SD evaluation result showed, if design cannot understand the perception image of Jimmy S.P.A and STRAUSS with viewers mind, furniture design also can't transmit feeling with design.

Optimizing the Design of Preprinted Orders for Ambulatory Chemotherapy: Combining Oncology, Human Factors, and Graphic Design

PubMed Central

Jeon, Jennifer; White, Rachel E.; Hunt, Richard G.; Cassano-Piché, Andrea L.; Easty, Anthony C.

2012-01-01

Purpose: To establish a set of guidelines for developing ambulatory chemotherapy preprinted orders. Methods: Multiple methods were used to develop the preprinted order guidelines. These included (A) a comprehensive literature review and an environmental scan; (B) analyses of field study observations and incident reports; (C) critical review of evidence from the literature and the field study observation analyses; (D) review of the draft guidelines by a clinical advisory group; and (E) collaboration with graphic designers to develop sample preprinted orders, refine the design guidelines, and format the resulting content. Results: The Guidelines for Developing Ambulatory Chemotherapy Preprinted Orders, which consist of guidance on the design process, content, and graphic design elements of ambulatory chemotherapy preprinted orders, have been established. Conclusion: Health care is a safety critical, dynamic, and complex sociotechnical system. Identifying safety risks in such a system and effectively addressing them often require the expertise of multiple disciplines. This study illustrates how human factors professionals, clinicians, and designers can leverage each other's expertise to uncover commonly overlooked patient safety hazards and to provide health care professionals with innovative, practical, and user-centered tools to minimize those hazards. PMID:23077436

Systematic Development and Validation of a Thin-Layer Densitometric Bioanalytical Method for Estimation of Mangiferin Employing Analytical Quality by Design (AQbD) Approach

PubMed Central

Khurana, Rajneet Kaur; Rao, Satish; Beg, Sarwar; Katare, O.P.; Singh, Bhupinder

2016-01-01

The present work aims at the systematic development of a simple, rapid and highly sensitive densitometry-based thin-layer chromatographic method for the quantification of mangiferin in bioanalytical samples. Initially, the quality target method profile was defined and critical analytical attributes (CAAs) earmarked, namely, retardation factor (Rf), peak height, capacity factor, theoretical plates and separation number. Face-centered cubic design was selected for optimization of volume loaded and plate dimensions as the critical method parameters selected from screening studies employing D-optimal and Plackett–Burman design studies, followed by evaluating their effect on the CAAs. The mobile phase containing a mixture of ethyl acetate : acetic acid : formic acid : water in a 7 : 1 : 1 : 1 (v/v/v/v) ratio was finally selected as the optimized solvent for apt chromatographic separation of mangiferin at 262 nm with Rf 0.68 ± 0.02 and all other parameters within the acceptance limits. Method validation studies revealed high linearity in the concentration range of 50–800 ng/band for mangiferin. The developed method showed high accuracy, precision, ruggedness, robustness, specificity, sensitivity, selectivity and recovery. In a nutshell, the bioanalytical method for analysis of mangiferin in plasma revealed the presence of well-resolved peaks and high recovery of mangiferin. PMID:26912808

A regularized variable selection procedure in additive hazards model with stratified case-cohort design.

PubMed

Ni, Ai; Cai, Jianwen

2018-07-01

Case-cohort designs are commonly used in large epidemiological studies to reduce the cost associated with covariate measurement. In many such studies the number of covariates is very large. An efficient variable selection method is needed for case-cohort studies where the covariates are only observed in a subset of the sample. Current literature on this topic has been focused on the proportional hazards model. However, in many studies the additive hazards model is preferred over the proportional hazards model either because the proportional hazards assumption is violated or the additive hazards model provides more relevent information to the research question. Motivated by one such study, the Atherosclerosis Risk in Communities (ARIC) study, we investigate the properties of a regularized variable selection procedure in stratified case-cohort design under an additive hazards model with a diverging number of parameters. We establish the consistency and asymptotic normality of the penalized estimator and prove its oracle property. Simulation studies are conducted to assess the finite sample performance of the proposed method with a modified cross-validation tuning parameter selection methods. We apply the variable selection procedure to the ARIC study to demonstrate its practical use.

Acoustic Treatment Design Scaling Methods. Phase 2

NASA Technical Reports Server (NTRS)

Clark, L. (Technical Monitor); Parrott, T. (Technical Monitor); Jones, M. (Technical Monitor); Kraft, R. E.; Yu, J.; Kwan, H. W.; Beer, B.; Seybert, A. F.; Tathavadekar, P.

2003-01-01

The ability to design, build and test miniaturized acoustic treatment panels on scale model fan rigs representative of full scale engines provides not only cost-savings, but also an opportunity to optimize the treatment by allowing multiple tests. To use scale model treatment as a design tool, the impedance of the sub-scale liner must be known with confidence. This study was aimed at developing impedance measurement methods for high frequencies. A normal incidence impedance tube method that extends the upper frequency range to 25,000 Hz. without grazing flow effects was evaluated. The free field method was investigated as a potential high frequency technique. The potential of the two-microphone in-situ impedance measurement method was evaluated in the presence of grazing flow. Difficulties in achieving the high frequency goals were encountered in all methods. Results of developing a time-domain finite difference resonator impedance model indicated that a re-interpretation of the empirical fluid mechanical models used in the frequency domain model for nonlinear resistance and mass reactance may be required. A scale model treatment design that could be tested on the Universal Propulsion Simulator vehicle was proposed.

In-Flight System Identification

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

1998-01-01

A method is proposed and studied whereby the system identification cycle consisting of experiment design and data analysis can be repeatedly implemented aboard a test aircraft in real time. This adaptive in-flight system identification scheme has many advantages, including increased flight test efficiency, adaptability to dynamic characteristics that are imperfectly known a priori, in-flight improvement of data quality through iterative input design, and immediate feedback of the quality of flight test results. The technique uses equation error in the frequency domain with a recursive Fourier transform for the real time data analysis, and simple design methods employing square wave input forms to design the test inputs in flight. Simulation examples are used to demonstrate that the technique produces increasingly accurate model parameter estimates resulting from sequentially designed and implemented flight test maneuvers. The method has reasonable computational requirements, and could be implemented aboard an aircraft in real time.

Three dimensional finite element methods: Their role in the design of DC accelerator systems

NASA Astrophysics Data System (ADS)

Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W.

2013-04-01

High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 × 300 mm2. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

Design and integration of ethnography within an international behavior change HIV/sexually transmitted disease prevention trial

PubMed Central

2008-01-01

Objective To use a common ethnographic study protocol across five countries to provide data to confirm social and risk settings and risk behaviors, develop the assessment instruments, tailor the intervention, design a process evaluation of the intervention, and design an understandable informed consent process. Design Methods determined best for capturing the core data elements were selected. Standards for data collection methods were established to enable comparable implementation of the ethnographic study across the five countries. Methods The methods selected were participant observation, focus groups, open-ended interviews, and social mapping. Standards included adhering to core data elements, number of participants, mode of data collection, type of data collection instrument, number of data collectors at each type of activity, duration of each type of activity, and type of informed consent administered. Sites had discretion in selecting which methods to use to obtain specific data. Results The ethnographic studies provided input to the Trial’s methods for data collection, described social groups in the target communities, depicted sexual practices, and determined core opinion leader characteristics; thus providing information that drove the adaptation of the intervention and facilitated the selection of venues, behavioral outcomes, and community popular opinion leaders (C-POLs). Conclusion The described rapid ethnographic approach worked well across the five countries, where findings allowed local adaptation of the intervention. When introducing the C-POL intervention in new areas, local non-governmental and governmental community and health workers can use this rapid ethnographic approach to identify the communities, social groups, messages, and C-POLs best suited for local implementation. PMID:17413263

Open Vehicle Sketch Pad Aircraft Modeling Strategies

NASA Technical Reports Server (NTRS)

Hahn, Andrew S.

2013-01-01

Geometric modeling of aircraft during the Conceptual design phase is very different from that needed for the Preliminary or Detailed design phases. The Conceptual design phase is characterized by the rapid, multi-disciplinary analysis of many design variables by a small engineering team. The designer must walk a line between fidelity and productivity, picking tools and methods with the appropriate balance of characteristics to achieve the goals of the study, while staying within the available resources. Identifying geometric details that are important, and those that are not, is critical to making modeling and methodology choices. This is true for both the low-order analysis methods traditionally used in Conceptual design as well as the highest-order analyses available. This paper will highlight some of Conceptual design's characteristics that drive the designer s choices as well as modeling examples for several aircraft configurations using the open source version of the Vehicle Sketch Pad (Open VSP) aircraft Conceptual design geometry modeler.

A nonparametric method to generate synthetic populations to adjust for complex sampling design features.

PubMed

Dong, Qi; Elliott, Michael R; Raghunathan, Trivellore E

2014-06-01

Outside of the survey sampling literature, samples are often assumed to be generated by a simple random sampling process that produces independent and identically distributed (IID) samples. Many statistical methods are developed largely in this IID world. Application of these methods to data from complex sample surveys without making allowance for the survey design features can lead to erroneous inferences. Hence, much time and effort have been devoted to develop the statistical methods to analyze complex survey data and account for the sample design. This issue is particularly important when generating synthetic populations using finite population Bayesian inference, as is often done in missing data or disclosure risk settings, or when combining data from multiple surveys. By extending previous work in finite population Bayesian bootstrap literature, we propose a method to generate synthetic populations from a posterior predictive distribution in a fashion inverts the complex sampling design features and generates simple random samples from a superpopulation point of view, making adjustment on the complex data so that they can be analyzed as simple random samples. We consider a simulation study with a stratified, clustered unequal-probability of selection sample design, and use the proposed nonparametric method to generate synthetic populations for the 2006 National Health Interview Survey (NHIS), and the Medical Expenditure Panel Survey (MEPS), which are stratified, clustered unequal-probability of selection sample designs.

A nonparametric method to generate synthetic populations to adjust for complex sampling design features

PubMed Central

Dong, Qi; Elliott, Michael R.; Raghunathan, Trivellore E.

2017-01-01

Outside of the survey sampling literature, samples are often assumed to be generated by a simple random sampling process that produces independent and identically distributed (IID) samples. Many statistical methods are developed largely in this IID world. Application of these methods to data from complex sample surveys without making allowance for the survey design features can lead to erroneous inferences. Hence, much time and effort have been devoted to develop the statistical methods to analyze complex survey data and account for the sample design. This issue is particularly important when generating synthetic populations using finite population Bayesian inference, as is often done in missing data or disclosure risk settings, or when combining data from multiple surveys. By extending previous work in finite population Bayesian bootstrap literature, we propose a method to generate synthetic populations from a posterior predictive distribution in a fashion inverts the complex sampling design features and generates simple random samples from a superpopulation point of view, making adjustment on the complex data so that they can be analyzed as simple random samples. We consider a simulation study with a stratified, clustered unequal-probability of selection sample design, and use the proposed nonparametric method to generate synthetic populations for the 2006 National Health Interview Survey (NHIS), and the Medical Expenditure Panel Survey (MEPS), which are stratified, clustered unequal-probability of selection sample designs. PMID:29200608

A strategy for quantum algorithm design assisted by machine learning

NASA Astrophysics Data System (ADS)

Bang, Jeongho; Ryu, Junghee; Yoo, Seokwon; Pawłowski, Marcin; Lee, Jinhyoung

2014-07-01

We propose a method for quantum algorithm design assisted by machine learning. The method uses a quantum-classical hybrid simulator, where a ‘quantum student’ is being taught by a ‘classical teacher’. In other words, in our method, the learning system is supposed to evolve into a quantum algorithm for a given problem, assisted by a classical main-feedback system. Our method is applicable for designing quantum oracle-based algorithms. We chose, as a case study, an oracle decision problem, called a Deutsch-Jozsa problem. We showed by using Monte Carlo simulations that our simulator can faithfully learn a quantum algorithm for solving the problem for a given oracle. Remarkably, the learning time is proportional to the square root of the total number of parameters, rather than showing the exponential dependence found in the classical machine learning-based method.

Design of experiments for amino acid extraction from tobacco leaves and their subsequent determination by capillary zone electrophoresis.

PubMed

Hodek, Ondřej; Křížek, Tomáš; Coufal, Pavel; Ryšlavá, Helena

2017-03-01

In this study, we optimized a method for the determination of free amino acids in Nicotiana tabacum leaves. Capillary electrophoresis with contactless conductivity detector was used for the separation of 20 proteinogenic amino acids in acidic background electrolyte. Subsequently, the conditions of extraction with HCl were optimized for the highest extraction yield of the amino acids because sample treatment of plant materials brings some specific challenges. Central composite face-centered design with fractional factorial design was used in order to evaluate the significance of selected factors (HCl volume, HCl concentration, sonication, shaking) on the extraction process. In addition, the composite design helped us to find the optimal values for each factor using the response surface method. The limits of detection and limits of quantification for the 20 proteinogenic amino acids were found to be in the order of 10 -5 and 10 -4  mol l -1 , respectively. Addition of acetonitrile to the sample was tested as a method commonly used to decrease limits of detection. Ambiguous results of this experiment pointed out some features of plant extract samples, which often required specific approaches. Suitability of the method for metabolomic studies was tested by analysis of a real sample, in which all amino acids, except for L-methionine and L-cysteine, were successfully detected. The optimized extraction process together with the capillary electrophoresis method can be used for the determination of proteinogenic amino acids in plant materials. The resulting inexpensive, simple, and robust method is well suited for various metabolomic studies in plants. As such, the method represents a valuable tool for research and practical application in the fields of biology, biochemistry, and agriculture.

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

NASA Astrophysics Data System (ADS)

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.

The Topology Optimization Design Research for Aluminum Inner Panel of Automobile Engine Hood

NASA Astrophysics Data System (ADS)

Li, Minhao; Hu, Dongqing; Liu, Xiangzheng; Yuan, Huanquan

2017-11-01

This article discusses the topology optimization methods for automobile engine hood design. The aluminum inner panel of engine hood and mucilage glue regions are set as design areas, and the static performances of engine hood included modal frequency, lateral stiffness, torsional stiffness and indentation stiffness are set as the optimization objectives. The topology optimization results about different objective functions are contrasted for analysis. And based on the reasonable topology optimization result, a suited automobile engine hood designs are raised to further study. Finally, an automobile engine hood that good at all of static performances is designed, and a favorable topology optimization method is put forward for discussion.

An adaptive two-stage dose-response design method for establishing proof of concept.

PubMed

Franchetti, Yoko; Anderson, Stewart J; Sampson, Allan R

2013-01-01

We propose an adaptive two-stage dose-response design where a prespecified adaptation rule is used to add and/or drop treatment arms between the stages. We extend the multiple comparison procedures-modeling (MCP-Mod) approach into a two-stage design. In each stage, we use the same set of candidate dose-response models and test for a dose-response relationship or proof of concept (PoC) via model-associated statistics. The stage-wise test results are then combined to establish "global" PoC using a conditional error function. Our simulation studies showed good and more robust power in our design method compared to conventional and fixed designs.

Full potential methods for analysis/design of complex aerospace configurations

NASA Technical Reports Server (NTRS)

Shankar, Vijaya; Szema, Kuo-Yen; Bonner, Ellwood

1986-01-01

The steady form of the full potential equation, in conservative form, is employed to analyze and design a wide variety of complex aerodynamic shapes. The nonlinear method is based on the theory of characteristic signal propagation coupled with novel flux biasing concepts and body-fitted mapping procedures. The resulting codes are vectorized for the CRAY XMP and the VPS-32 supercomputers. Use of the full potential nonlinear theory is demonstrated for a single-point supersonic wing design and a multipoint design for transonic maneuver/supersonic cruise/maneuver conditions. Achievement of high aerodynamic efficiency through numerical design is verified by wind tunnel tests. Other studies reported include analyses of a canard/wing/nacelle fighter geometry.

Study on light weight design of truss structures of spacecrafts

NASA Astrophysics Data System (ADS)

Zeng, Fuming; Yang, Jianzhong; Wang, Jian

2015-08-01

Truss structure is usually adopted as the main structure form for spacecrafts due to its high efficiency in supporting concentrated loads. Light-weight design is now becoming the primary concern during conceptual design of spacecrafts. Implementation of light-weight design on truss structure always goes through three processes: topology optimization, size optimization and composites optimization. During each optimization process, appropriate algorithm such as the traditional optimality criterion method, mathematical programming method and the intelligent algorithms which simulate the growth and evolution processes in nature will be selected. According to the practical processes and algorithms, combined with engineering practice and commercial software, summary is made for the implementation of light-weight design on truss structure for spacecrafts.

An approach for aerodynamic optimization of transonic fan blades

NASA Astrophysics Data System (ADS)

Khelghatibana, Maryam

Aerodynamic design optimization of transonic fan blades is a highly challenging problem due to the complexity of flow field inside the fan, the conflicting design requirements and the high-dimensional design space. In order to address all these challenges, an aerodynamic design optimization method is developed in this study. This method automates the design process by integrating a geometrical parameterization method, a CFD solver and numerical optimization methods that can be applied to both single and multi-point optimization design problems. A multi-level blade parameterization is employed to modify the blade geometry. Numerical analyses are performed by solving 3D RANS equations combined with SST turbulence model. Genetic algorithms and hybrid optimization methods are applied to solve the optimization problem. In order to verify the effectiveness and feasibility of the optimization method, a singlepoint optimization problem aiming to maximize design efficiency is formulated and applied to redesign a test case. However, transonic fan blade design is inherently a multi-faceted problem that deals with several objectives such as efficiency, stall margin, and choke margin. The proposed multi-point optimization method in the current study is formulated as a bi-objective problem to maximize design and near-stall efficiencies while maintaining the required design pressure ratio. Enhancing these objectives significantly deteriorate the choke margin, specifically at high rotational speeds. Therefore, another constraint is embedded in the optimization problem in order to prevent the reduction of choke margin at high speeds. Since capturing stall inception is numerically very expensive, stall margin has not been considered as an objective in the problem statement. However, improving near-stall efficiency results in a better performance at stall condition, which could enhance the stall margin. An investigation is therefore performed on the Pareto-optimal solutions to demonstrate the relation between near-stall efficiency and stall margin. The proposed method is applied to redesign NASA rotor 67 for single and multiple operating conditions. The single-point design optimization showed +0.28 points improvement of isentropic efficiency at design point, while the design pressure ratio and mass flow are, respectively, within 0.12% and 0.11% of the reference blade. Two cases of multi-point optimization are performed: First, the proposed multi-point optimization problem is relaxed by removing the choke margin constraint in order to demonstrate the relation between near-stall efficiency and stall margin. An investigation on the Pareto-optimal solutions of this optimization shows that the stall margin has been increased with improving near-stall efficiency. The second multi-point optimization case is performed with considering all the objectives and constraints. One selected optimized design on the Pareto front presents +0.41, +0.56 and +0.9 points improvement in near-peak efficiency, near-stall efficiency and stall margin, respectively. The design pressure ratio and mass flow are, respectively, within 0.3% and 0.26% of the reference blade. Moreover the optimized design maintains the required choking margin. Detailed aerodynamic analyses are performed to investigate the effect of shape optimization on shock occurrence, secondary flows, tip leakage and shock/tip-leakage interactions in both single and multi-point optimizations.

Assessing the Effect of Dental Implants Thread Design on Distribution of Stress in Impact Loadings Using Three Dimensional Finite Element Method

PubMed Central

I, Zarei; S, Khajehpour; A, Sabouri; AZ, Haghnegahdar; K, Jafari

2016-01-01

Statement of Problem: Impacts and accidents are considered as the main fac- tors in losing the teeth, so the analysis and design of the implants that they can be more resistant against impacts is very important. One of the important nu- merical methods having widespread application in various fields of engineering sciences is the finite element method. Among its wide applications, the study of distribution of power in complex structures can be noted. Objectives: The aim of this research was to assess the geometric effect and the type of implant thread on its performance; we also made an attempt to determine the created stress using finite element method. Materials and Methods: In this study, the three dimensional model of bone by using Cone Beam Computerized Tomography (CBCT) of the patient has been provided. The implants in this study are designed by Solid Works software. Loading is simulated in explicit dynamic, by struck of a rigid body with the speed of 1 mm/s to implant vertically and horizontally; and the maximum level of induced stress for the cortical and trabecular bone in the ANSYS Workbench software was calculated. Results: By considering the results of this study, it was identified that, among the designed samples, the maximum imposed stress in the cortical bone layer occurred in the first group (straight threads) and the maximum stress value in the trabecular bone layer and implant occurred in the second group (tapered threads). Conclusions: Due to the limitations of this study, the implants with more depth thread, because of the increased contact surface of the implant with the bone, caused more stability; also, the implant with smaller thread and shorter pitch length caused more stress to the bone. PMID:28959748

Virtual screening and rational drug design method using structure generation system based on 3D-QSAR and docking.

PubMed

Chen, H F; Dong, X C; Zen, B S; Gao, K; Yuan, S G; Panaye, A; Doucet, J P; Fan, B T

2003-08-01

An efficient virtual and rational drug design method is presented. It combines virtual bioactive compound generation with 3D-QSAR model and docking. Using this method, it is possible to generate a lot of highly diverse molecules and find virtual active lead compounds. The method was validated by the study of a set of anti-tumor drugs. With the constraints of pharmacophore obtained by DISCO implemented in SYBYL 6.8, 97 virtual bioactive compounds were generated, and their anti-tumor activities were predicted by CoMFA. Eight structures with high activity were selected and screened by the 3D-QSAR model. The most active generated structure was further investigated by modifying its structure in order to increase the activity. A comparative docking study with telomeric receptor was carried out, and the results showed that the generated structures could form more stable complexes with receptor than the reference compound selected from experimental data. This investigation showed that the proposed method was a feasible way for rational drug design with high screening efficiency.

Space station ventilation study

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Allen, G. E.

1972-01-01

A ventilation system design and selection method which is applicable to any manned vehicle were developed. The method was used to generate design options for the NASA 33-foot diameter space station, all of which meet the ventilation system design requirements. System characteristics such as weight, volume, and power were normalized to dollar costs for each option. Total system costs for the various options ranged from a worst case $8 million to a group of four which were all approximately $2 million. A system design was then chosen from the $2 million group and is presented in detail. A ventilation system layout was designed for the MSFC space station mockup which provided comfortable, efficient ventilation of the mockup. A conditioned air distribution system design for the 14-foot diameter modular space station, using the same techniques, is also presented. The tradeoff study resulted in the selection of a system which costs $1.9 million, as compared to the alternate configuration which would have cost $2.6 million.

Methods to enable the design of bioactive small molecules targeting RNA

PubMed Central

Disney, Matthew D.; Yildirim, Ilyas; Childs-Disney, Jessica L.

2014-01-01

RNA is an immensely important target for small molecule therapeutics or chemical probes of function. However, methods that identify, annotate, and optimize RNA-small molecule interactions that could enable the design of compounds that modulate RNA function are in their infancies. This review describes recent approaches that have been developed to understand and optimize RNA motif-small molecule interactions, including Structure-Activity Relationships Through Sequencing (StARTS), quantitative structure-activity relationships (QSAR), chemical similarity searching, structure-based design and docking, and molecular dynamics (MD) simulations. Case studies described include the design of small molecules targeting RNA expansions, the bacterial A-site, viral RNAs, and telomerase RNA. These approaches can be combined to afford a synergistic method to exploit the myriad of RNA targets in the transcriptome. PMID:24357181

Methods to enable the design of bioactive small molecules targeting RNA.

PubMed

Disney, Matthew D; Yildirim, Ilyas; Childs-Disney, Jessica L

2014-02-21

RNA is an immensely important target for small molecule therapeutics or chemical probes of function. However, methods that identify, annotate, and optimize RNA-small molecule interactions that could enable the design of compounds that modulate RNA function are in their infancies. This review describes recent approaches that have been developed to understand and optimize RNA motif-small molecule interactions, including structure-activity relationships through sequencing (StARTS), quantitative structure-activity relationships (QSAR), chemical similarity searching, structure-based design and docking, and molecular dynamics (MD) simulations. Case studies described include the design of small molecules targeting RNA expansions, the bacterial A-site, viral RNAs, and telomerase RNA. These approaches can be combined to afford a synergistic method to exploit the myriad of RNA targets in the transcriptome.

Aircraft Conceptual Design and Risk Analysis Using Physics-Based Noise Prediction

NASA Technical Reports Server (NTRS)

Olson, Erik D.; Mavris, Dimitri N.

2006-01-01

An approach was developed which allows for design studies of commercial aircraft using physics-based noise analysis methods while retaining the ability to perform the rapid trade-off and risk analysis studies needed at the conceptual design stage. A prototype integrated analysis process was created for computing the total aircraft EPNL at the Federal Aviation Regulations Part 36 certification measurement locations using physics-based methods for fan rotor-stator interaction tones and jet mixing noise. The methodology was then used in combination with design of experiments to create response surface equations (RSEs) for the engine and aircraft performance metrics, geometric constraints and take-off and landing noise levels. In addition, Monte Carlo analysis was used to assess the expected variability of the metrics under the influence of uncertainty, and to determine how the variability is affected by the choice of engine cycle. Finally, the RSEs were used to conduct a series of proof-of-concept conceptual-level design studies demonstrating the utility of the approach. The study found that a key advantage to using physics-based analysis during conceptual design lies in the ability to assess the benefits of new technologies as a function of the design to which they are applied. The greatest difficulty in implementing physics-based analysis proved to be the generation of design geometry at a sufficient level of detail for high-fidelity analysis.

Sizing Firefighters: Method and Implications

PubMed Central

Hsiao, Hongwei; Whitestone, Jennifer; Kau, Tsui-Ying; Whisler, Richard; Routley, J. Gordon; Wilbur, Michael

2015-01-01

Objective This article reports new anthropometric information of U.S. firefighters for fire apparatus design applications (Study 1) and presents a data method to assist in firefighter anthropometric data usage for research-to-practice propositions (Study 2). Background Up-to-date anthropometric information of the U.S. firefighter population is needed for updating ergonomic and safety specifications for fire apparatus. Method A stratified sampling plan of three-age by three-race/ethnicity combinations was used to collect anthropometric data of 863 male and 88 female firefighters across the U.S. regions; 71 anthropometric dimensions were measured (Study 1). Differences among original, weighted, and normality transformed data from Study 1 were compared to allowable observer errors (Study 2). Results On average, male firefighters were 9.8 kg heavier and female firefighters were 29 mm taller than their counterparts in the general U.S. population. They also have larger upper-body builds than those of the general U.S. population. The data in weighted, unweighted, and normality transformed modes were compatible among each other with a few exceptions. Conclusion The data obtained in this study provide the first available U.S. national firefighter anthropometric information for fire apparatus designs. The data represent the demographic characteristics of the current firefighter population and, except for a few dimensions, can be directly employed into fire apparatus design applications without major weighting or nonnormality concerns. Application The up-to-date firefighter anthropometric data and data method will benefit the design of future fire apparatus and protective equipment, such as seats, body restraints, cabs, gloves, and bunker gear. PMID:25141595

77 FR 14036 - Draft Environmental Impact Statement for Experimental Removal of Barred Owls to Benefit...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... and location of study areas, the type of experimental design, duration of study, and method of barred... by the number and location of study areas, the type of experimental design, duration of the study...-FF01E00000] Draft Environmental Impact Statement for Experimental Removal of Barred Owls to Benefit...

A novel quality by design approach for developing an HPLC method to analyze herbal extracts: A case study of sugar content analysis.

PubMed

Shao, Jingyuan; Cao, Wen; Qu, Haibin; Pan, Jianyang; Gong, Xingchu

2018-01-01

The aim of this study was to present a novel analytical quality by design (AQbD) approach for developing an HPLC method to analyze herbal extracts. In this approach, critical method attributes (CMAs) and critical method parameters (CMPs) of the analytical method were determined using the same data collected from screening experiments. The HPLC-ELSD method for separation and quantification of sugars in Codonopsis Radix extract (CRE) samples and Astragali Radix extract (ARE) samples was developed as an example method with a novel AQbD approach. Potential CMAs and potential CMPs were found with Analytical Target Profile. After the screening experiments, the retention time of the D-glucose peak of CRE samples, the signal-to-noise ratio of the D-glucose peak of CRE samples, and retention time of the sucrose peak in ARE samples were considered CMAs. The initial and final composition of the mobile phase, flow rate, and column temperature were found to be CMPs using a standard partial regression coefficient method. The probability-based design space was calculated using a Monte-Carlo simulation method and verified by experiments. The optimized method was validated to be accurate and precise, and then it was applied in the analysis of CRE and ARE samples. The present AQbD approach is efficient and suitable for analysis objects with complex compositions.

Automated statistical experimental design approach for rapid separation of coenzyme Q10 and identification of its biotechnological process related impurities using UHPLC and UHPLC-APCI-MS.

PubMed

Talluri, Murali V N Kumar; Kalariya, Pradipbhai D; Dharavath, Shireesha; Shaikh, Naeem; Garg, Prabha; Ramisetti, Nageswara Rao; Ragampeta, Srinivas

2016-09-01

A novel ultra high performance liquid chromatography method development strategy was ameliorated by applying quality by design approach. The developed systematic approach was divided into five steps (i) Analytical Target Profile, (ii) Critical Quality Attributes, (iii) Risk Assessments of Critical parameters using design of experiments (screening and optimization phases), (iv) Generation of design space, and (v) Process Capability Analysis (Cp) for robustness study using Monte Carlo simulation. The complete quality-by-design-based method development was made automated and expedited by employing sub-2 μm particles column with an ultra high performance liquid chromatography system. Successful chromatographic separation of the Coenzyme Q10 from its biotechnological process related impurities was achieved on a Waters Acquity phenyl hexyl (100 mm × 2.1 mm, 1.7 μm) column with gradient elution of 10 mM ammonium acetate buffer (pH 4.0) and a mixture of acetonitrile/2-propanol (1:1) as the mobile phase. Through this study, fast and organized method development workflow was developed and robustness of the method was also demonstrated. The method was validated for specificity, linearity, accuracy, precision, and robustness in compliance to the International Conference on Harmonization, Q2 (R1) guidelines. The impurities were identified by atmospheric pressure chemical ionization-mass spectrometry technique. Further, the in silico toxicity of impurities was analyzed using TOPKAT and DEREK software. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed Central

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

2013-01-01

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

Exploring the Effects of Online Team-Based Learning and Co-Regulated Learning on Students' Development of Computing Skills

ERIC Educational Resources Information Center

Tsai, Chia-Wen

2016-01-01

As more and more educational institutions are providing online courses, it is necessary to design effective teaching methods integrated with technologies to benefit both teachers and students. The researcher in this study designed innovative online teaching methods of team-based learning (TBL) and co-regulated learning (CRL) to improve students'…

Designing Low Carbon Higher Education Systems: Environmental Impacts of Campus and Distance Learning Systems

ERIC Educational Resources Information Center

Roy, Robin; Potter, Stephen; Yarrow, Karen

2008-01-01

Purpose: This paper aims to summarise the methods and main findings of a study of the environmental impacts of providing higher education (HE) courses by campus-based and distance/open-learning methods. Design/methodology/approach: The approach takes the form of an environmental audit, with data from surveys of 20 UK courses--13 campus-based,…

Ambivalence and Fluidity in the Teenage Smoking and Quitting Experience: Lessons from a Qualitative Study at an English Secondary School

ERIC Educational Resources Information Center

Buswell, Marina; Duncan, Peter

2013-01-01

Objective: To evaluate a school-based stop smoking pilot project and to understand the teenage experience of smoking and quitting within that context. Design: Flexible design methods. Setting: A Kent (United Kingdom [UK]) secondary school. Methods: Semi-structured interviews analyzed following a grounded theory approach. Results: The main themes…

The Effect of Using the Creative Reversal Act in Science Education on Middle School Students' Creativity Levels

ERIC Educational Resources Information Center

Karaca, Tulin; Koray, Ozlem

2017-01-01

Purpose: The purpose of this study is to examine the effects of the creative reversal act (CREACT) used in teaching ecosystems topics on the creativity levels of middle school students. Research Methods: The research was conducted using a quasi-experimental design, a quantitative research method, and a pretest-posttest control group design. The…

An Analysis of the Design and Implementation of Elementary Science Methods Class Instruction in Colleges and Universities in Arkansas

ERIC Educational Resources Information Center

Lee, Carole K.

2010-01-01

This study aims to understand the design and implementation of elementary methods classes focused in science instruction by teacher educators in the colleges and universities in the state of Arkansas. All 18 institutions with an Early Childhood Education program approved by the Arkansas Department of Education were reviewed with interviews, site…

Discrete Optimization of Electronic Hyperpolarizabilities in a Chemical Subspace

DTIC Science & Technology

2009-05-01

molecular design. Methods for optimization in discrete spaces have been studied extensively and recently reviewed ( 5). Optimization methods include...integer programming, as in branch-and-bound techniques (including dead-end elimination [ 6]), simulated annealing ( 7), and genetic algorithms ( 8...These algorithms have found renewed interest and application in molecular and materials design (9- 12) . Recently, new approaches have been

An Evaluation of the Conservative Dual-Criterion Method for Teaching University Students to Visually Inspect AB-Design Graphs

ERIC Educational Resources Information Center

Stewart, Kelise K.; Carr, James E.; Brandt, Charles W.; McHenry, Meade M.

2007-01-01

The present study evaluated the effects of both a traditional lecture and the conservative dual-criterion (CDC) judgment aid on the ability of 6 university students to visually inspect AB-design line graphs. The traditional lecture reliably failed to improve visual inspection accuracy, whereas the CDC method substantially improved the performance…

A Comparison of Single Sample and Bootstrap Methods to Assess Mediation in Cluster Randomized Trials

ERIC Educational Resources Information Center

Pituch, Keenan A.; Stapleton, Laura M.; Kang, Joo Youn

2006-01-01

A Monte Carlo study examined the statistical performance of single sample and bootstrap methods that can be used to test and form confidence interval estimates of indirect effects in two cluster randomized experimental designs. The designs were similar in that they featured random assignment of clusters to one of two treatment conditions and…

The Development of a Robot-Based Learning Companion: A User-Centered Design Approach

ERIC Educational Resources Information Center

Hsieh, Yi-Zeng; Su, Mu-Chun; Chen, Sherry Y.; Chen, Gow-Dong

2015-01-01

A computer-vision-based method is widely employed to support the development of a variety of applications. In this vein, this study uses a computer-vision-based method to develop a playful learning system, which is a robot-based learning companion named RobotTell. Unlike existing playful learning systems, a user-centered design (UCD) approach is…

Bioelectrochemical Systems Workshop:Standardized Analyses, Design Benchmarks, and Reporting

DTIC Science & Technology

2012-01-01

related to the exoelectrogenic biofilm activity, and to investigate whether the community structure is a function of design and operational parameters...where should biofilm samples be collected? The most prevalent methods of community characterization in BES studies have entailed phylogenetic ...of function associated with this genetic marker, and in methods that involve polymerase chain reaction (PCR) amplification the quantitative