Science.gov

Sample records for systematic design methodology

  1. Systematic Controller Design Methodology for Variable-Speed Wind Turbines

    SciTech Connect

    Hand, M. M.; Balas, M. J.

    2002-02-01

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three operational regions. This paper provides a guide for controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship between the two opposing metrics is easily visualized.

  2. Systematic defect filtering and data analysis methodology for design based metrology

    NASA Astrophysics Data System (ADS)

    Yang, Hyunjo; Kim, Jungchan; Lee, Taehyeong; Jung, Areum; Yoo, Gyun; Yim, Donggyu; Park, Sungki; Hasebe, Toshiaki; Yamamoto, Masahiro; Cai, Jun

    2009-03-01

    Recently several Design Based Metrologies (DBMs) are introduced and being in use for wafer verification. The major applications of DBM are OPC accuracy improvement, DFM feed-back through Process Window Qualification (PWQ) and advanced process control. In general, however, the amount of output data from DBM is normally so large that it is very hard to handle the data for valuable feed-back. In case of PWQ, more than thousands of hot spots are detected on a single chip at the edge of process window. So, it takes much time and labor to review and analyze all the hot spots detected at PWQ. Design-related systematic defects, however, will be found repeatedly and if they can be classified into groups, it would be possible to save a lot of time for the analysis. We have demonstrated an EDA tool which can handle the large amount of output data from DBM by reducing pattern defects to groups. It can classify millions of patterns into less than thousands of pattern groups. It has been evaluated on the analysis of PWQ of metal layer in NAND Flash memory device and random contact hole patterns in a DRAM device. The result shows that this EDA tool can handle the CD measurement data easily and can save us a lot of time and labor for the analysis. The procedures of systematic defect filtering and data handling using an EDA tool are presented in detail

  3. Systematic design methodology for robust genetic transistors based on I/O specifications via promoter-RBS libraries

    PubMed Central

    2013-01-01

    Background Synthetic genetic transistors are vital for signal amplification and switching in genetic circuits. However, it is still problematic to efficiently select the adequate promoters, Ribosome Binding Sides (RBSs) and inducer concentrations to construct a genetic transistor with the desired linear amplification or switching in the Input/Output (I/O) characteristics for practical applications. Results Three kinds of promoter-RBS libraries, i.e., a constitutive promoter-RBS library, a repressor-regulated promoter-RBS library and an activator-regulated promoter-RBS library, are constructed for systematic genetic circuit design using the identified kinetic strengths of their promoter-RBS components. According to the dynamic model of genetic transistors, a design methodology for genetic transistors via a Genetic Algorithm (GA)-based searching algorithm is developed to search for a set of promoter-RBS components and adequate concentrations of inducers to achieve the prescribed I/O characteristics of a genetic transistor. Furthermore, according to design specifications for different types of genetic transistors, a look-up table is built for genetic transistor design, from which we could easily select an adequate set of promoter-RBS components and adequate concentrations of external inducers for a specific genetic transistor. Conclusion This systematic design method will reduce the time spent using trial-and-error methods in the experimental procedure for a genetic transistor with a desired I/O characteristic. We demonstrate the applicability of our design methodology to genetic transistors that have desirable linear amplification or switching by employing promoter-RBS library searching. PMID:24160305

  4. Design methodology of Dutch banknotes

    NASA Astrophysics Data System (ADS)

    de Heij, Hans A. M.

    2000-04-01

    Since the introduction of a design methodology for Dutch banknotes, the quality of Dutch paper currency has improved in more than one way. The methodology is question provides for (i) a design policy, which helps fix clear objectives; (ii) design management, to ensure a smooth cooperation between the graphic designer, printer, papermaker an central bank, (iii) a program of requirements, a banknote development guideline for all parties involved. This systematic approach enables an objective selection of design proposals, including security features. Furthermore, the project manager obtains regular feedback from the public by conducting market surveys. Each new design of a Netherlands Guilder banknote issued by the Nederlandsche Bank of the past 50 years has been an improvement on its predecessor in terms of value recognition, security and durability.

  5. Autonomous spacecraft design methodology

    SciTech Connect

    Divita, E.L.; Turner, P.R.

    1984-08-01

    A methodology for autonomous spacecraft design blends autonomy requirements with traditional mission requirements and assesses the impact of autonomy upon the total system resources available to support faulttolerance and automation. A baseline functional design can be examined for autonomy implementation impacts, and the costs, risk, and benefits of various options can be assessed. The result of the process is a baseline design that includes autonomous control functions.

  6. Variable-Speed Wind Turbine Controller Systematic Design Methodology: A Comparison of Non-Linear and Linear Model-Based Designs

    SciTech Connect

    Hand, M. M.

    1999-07-30

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. Traditional controller design generally consists of linearizing a model about an operating point. This step was taken for two different operating points, and the systematic design approach was used. A comparison of the optimal regions selected using the n on-linear model and the two linear models shows similarities. The linearization point selection does, however, affect the turbine performance slightly. Exploitation of the simplicity of the model allows surfaces consisting of operation under a wide range of gain values to be created. This methodology provides a means of visually observing turbine performance based upon the two metrics chosen for this study. Design of a PID controller is simplified, and it is possible to ascertain the best possible combination of controller parameters. The wide, flat surfaces indicate that a PID controller is very robust in this variable-speed wind turbine application.

  7. Systematic Review Methodology in Higher Education

    ERIC Educational Resources Information Center

    Bearman, Margaret; Smith, Calvin D.; Carbone, Angela; Slade, Susan; Baik, Chi; Hughes-Warrington, Marnie; Neumann, David L.

    2012-01-01

    Systematic review methodology can be distinguished from narrative reviews of the literature through its emphasis on transparent, structured and comprehensive approaches to searching the literature and its requirement for formal synthesis of research findings. There appears to be relatively little use of the systematic review methodology within the…

  8. Systematic Review Methodology in Higher Education

    ERIC Educational Resources Information Center

    Bearman, Margaret; Smith, Calvin D.; Carbone, Angela; Slade, Susan; Baik, Chi; Hughes-Warrington, Marnie; Neumann, David L.

    2012-01-01

    Systematic review methodology can be distinguished from narrative reviews of the literature through its emphasis on transparent, structured and comprehensive approaches to searching the literature and its requirement for formal synthesis of research findings. There appears to be relatively little use of the systematic review methodology within the…

  9. Methodological quality of systematic reviews addressing femoroacetabular impingement.

    PubMed

    Kowalczuk, Marcin; Adamich, John; Simunovic, Nicole; Farrokhyar, Forough; Ayeni, Olufemi R

    2015-09-01

    As the body of literature on femoroacetabular impingement (FAI) continues to grow, clinicians turn to systematic reviews to remain current with the best available evidence. The quality of systematic reviews in the FAI literature is currently unknown. The goal of this study was to assess the quality of the reporting of systematic reviews addressing FAI over the last 11 years (2003-2014) and to identify the specific methodological shortcomings and strengths. A search of the electronic databases, MEDLINE, EMBASE and PubMed, was performed to identify relevant systematic reviews. Methodological quality was assessed by two reviewers using the revised assessment of multiple systematic reviews (R-AMSTAR) scoring tool. An intraclass correlation coefficient (ICC) with 95 % confidence intervals (CI) was used to determine agreement between reviewers on R-AMSTAR quality scores. A total of 22 systematic reviews were assessed for methodological quality. The mean consensus R-AMSTAR score across all studies was 26.7 out of 40.0, indicating fair methodological quality. An ICC of 0.931, 95 % CI 0.843-0.971 indicated excellent agreement between reviewers during the scoring process. The systematic reviews addressing FAI are generally of fair methodological quality. Use of tools such as the R-AMSTAR score or PRISMA guidelines while designing future systematic reviews can assist in eliminating methodological shortcomings identified in this review. These shortcomings need to be kept in mind by clinicians when applying the current literature to their patient populations and making treatment decisions. Systematic reviews of highest methodological quality should be used by clinicians when possible to answer clinical questions.

  10. Methodological Issues in Questionnaire Design.

    PubMed

    Song, Youngshin; Son, Youn Jung; Oh, Doonam

    2015-06-01

    The process of designing a questionnaire is complicated. Many questionnaires on nursing phenomena have been developed and used by nursing researchers. The purpose of this paper was to discuss questionnaire design and factors that should be considered when using existing scales. Methodological issues were discussed, such as factors in the design of questions, steps in developing questionnaires, wording and formatting methods for items, and administrations methods. How to use existing scales, how to facilitate cultural adaptation, and how to prevent socially desirable responding were discussed. Moreover, the triangulation method in questionnaire development was introduced. Steps were recommended for designing questions such as appropriately operationalizing key concepts for the target population, clearly formatting response options, generating items and confirming final items through face or content validity, sufficiently piloting the questionnaire using item analysis, demonstrating reliability and validity, finalizing the scale, and training the administrator. Psychometric properties and cultural equivalence should be evaluated prior to administration when using an existing questionnaire and performing cultural adaptation. In the context of well-defined nursing phenomena, logical and systematic methods will contribute to the development of simple and precise questionnaires.

  11. RAMCAD Design Methodology

    DTIC Science & Technology

    1993-05-01

    fault detection and isolation , and reduces...elements during the design process. Fault detection and isolation are simplified when an entire function can be assigned to a single hardware design element...defining the fault detection and isolation constraints and goals) are met or all of the test resources have been committed. Alternative resource

  12. Permanent magnet design methodology

    NASA Technical Reports Server (NTRS)

    Leupold, Herbert A.

    1991-01-01

    Design techniques developed for the exploitation of high energy magnetically rigid materials such as Sm-Co and Nd-Fe-B have resulted in a revolution in kind rather than in degree in the design of a variety of electron guidance structures for ballistic and aerospace applications. Salient examples are listed. Several prototype models were developed. These structures are discussed in some detail: permanent magnet solenoids, transverse field sources, periodic structures, and very high field structures.

  13. Solid lubrication design methodology

    NASA Technical Reports Server (NTRS)

    Aggarwal, B. B.; Yonushonis, T. M.; Bovenkerk, R. L.

    1984-01-01

    A single element traction rig was used to measure the traction forces at the contact of a ball against a flat disc at room temperature under combined rolling and sliding. The load and speed conditions were selected to match those anticipated for bearing applications in adiabatic diesel engines. The test program showed that the magnitude of traction forces were almost the same for all the lubricants tested; a lubricant should, therefore, be selected on the basis of its ability to prevent wear of the contact surfaces. Traction vs. slide/roll ratio curves were similar to those for liquid lubricants but the traction forces were an order of magnitude higher. The test data was used to derive equations to predict traction force as a function of contact stress and rolling speed. Qualitative design guidelines for solid lubricated concentrated contacts are proposed.

  14. Unattended Monitoring System Design Methodology

    SciTech Connect

    Drayer, D.D.; DeLand, S.M.; Harmon, C.D.; Matter, J.C.; Martinez, R.L.; Smith, J.D.

    1999-07-08

    A methodology for designing Unattended Monitoring Systems starting at a systems level has been developed at Sandia National Laboratories. This proven methodology provides a template that describes the process for selecting and applying appropriate technologies to meet unattended system requirements, as well as providing a framework for development of both training courses and workshops associated with unattended monitoring. The design and implementation of unattended monitoring systems is generally intended to respond to some form of policy based requirements resulting from international agreements or domestic regulations. Once the monitoring requirements are established, a review of the associated process and its related facilities enables identification of strategic monitoring locations and development of a conceptual system design. The detailed design effort results in the definition of detection components as well as the supporting communications network and data management scheme. The data analyses then enables a coherent display of the knowledge generated during the monitoring effort. The resultant knowledge is then compared to the original system objectives to ensure that the design adequately addresses the fundamental principles stated in the policy agreements. Implementation of this design methodology will ensure that comprehensive unattended monitoring system designs provide appropriate answers to those critical questions imposed by specific agreements or regulations. This paper describes the main features of the methodology and discusses how it can be applied in real world situations.

  15. Vending machine assessment methodology. A systematic review.

    PubMed

    Matthews, Melissa A; Horacek, Tanya M

    2015-07-01

    The nutritional quality of food and beverage products sold in vending machines has been implicated as a contributing factor to the development of an obesogenic food environment. How comprehensive, reliable, and valid are the current assessment tools for vending machines to support or refute these claims? A systematic review was conducted to summarize, compare, and evaluate the current methodologies and available tools for vending machine assessment. A total of 24 relevant research studies published between 1981 and 2013 met inclusion criteria for this review. The methodological variables reviewed in this study include assessment tool type, study location, machine accessibility, product availability, healthfulness criteria, portion size, price, product promotion, and quality of scientific practice. There were wide variations in the depth of the assessment methodologies and product healthfulness criteria utilized among the reviewed studies. Of the reviewed studies, 39% evaluated machine accessibility, 91% evaluated product availability, 96% established healthfulness criteria, 70% evaluated portion size, 48% evaluated price, 52% evaluated product promotion, and 22% evaluated the quality of scientific practice. Of all reviewed articles, 87% reached conclusions that provided insight into the healthfulness of vended products and/or vending environment. Product healthfulness criteria and complexity for snack and beverage products was also found to be variable between the reviewed studies. These findings make it difficult to compare results between studies. A universal, valid, and reliable vending machine assessment tool that is comprehensive yet user-friendly is recommended. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Fixed or random effects meta-analysis? Common methodological issues in systematic reviews of effectiveness.

    PubMed

    Tufanaru, Catalin; Munn, Zachary; Stephenson, Matthew; Aromataris, Edoardo

    2015-09-01

    Systematic review aims to systematically identify, critically appraise, and summarize all relevant studies that match predefined criteria and answer predefined questions. The most common type of systematic review is that assessing the effectiveness of an intervention or therapy. In this article, we discuss some of the common methodological issues that arise when conducting systematic reviews and meta-analyses of effectiveness data, including issues related to study designs, meta-analysis, and the use and interpretation of effect sizes.

  17. Waste Package Design Methodology Report

    SciTech Connect

    D.A. Brownson

    2001-09-28

    The objective of this report is to describe the analytical methods and processes used by the Waste Package Design Section to establish the integrity of the various waste package designs, the emplacement pallet, and the drip shield. The scope of this report shall be the methodology used in criticality, risk-informed, shielding, source term, structural, and thermal analyses. The basic features and appropriateness of the methods are illustrated, and the processes are defined whereby input values and assumptions flow through the application of those methods to obtain designs that ensure defense-in-depth as well as satisfy requirements on system performance. Such requirements include those imposed by federal regulation, from both the U.S. Department of Energy (DOE) and U.S. Nuclear Regulatory Commission (NRC), and those imposed by the Yucca Mountain Project to meet repository performance goals. The report is to be used, in part, to describe the waste package design methods and techniques to be used for producing input to the License Application Report.

  18. Gas turbine combustor design methodology

    SciTech Connect

    Rizk, N.K.; Mongia, H.C.

    1986-01-01

    The detailed representation of flow and combustion processes offered by multidimensional models and the predictive tool of the proven empirical correlations are combined to form a basis for a gas turbine combustor design method. Provisions are made to fully utilize the output of the analytical computations by evaluating the values of relevant parameters within subdivisions of liner sector. By this means, the impact of a systematic modification to the detail of dome swirlers and liner configuration is easily determined. A heat transfer calculation method that utilizes the variation in combustor parameters in the three dimensions and evaluates radiation flux components through a view factor is considered. In comparison with experimental data obtained for a typical production liner, the predictions of the developed method in regard to emission formation, combustion performance, and wall temperature are quite satisfactory.

  19. Methodology for Designing Fault-Protection Software

    NASA Technical Reports Server (NTRS)

    Barltrop, Kevin; Levison, Jeffrey; Kan, Edwin

    2006-01-01

    A document describes a methodology for designing fault-protection (FP) software for autonomous spacecraft. The methodology embodies and extends established engineering practices in the technical discipline of Fault Detection, Diagnosis, Mitigation, and Recovery; and has been successfully implemented in the Deep Impact Spacecraft, a NASA Discovery mission. Based on established concepts of Fault Monitors and Responses, this FP methodology extends the notion of Opinion, Symptom, Alarm (aka Fault), and Response with numerous new notions, sub-notions, software constructs, and logic and timing gates. For example, Monitor generates a RawOpinion, which graduates into Opinion, categorized into no-opinion, acceptable, or unacceptable opinion. RaiseSymptom, ForceSymptom, and ClearSymptom govern the establishment and then mapping to an Alarm (aka Fault). Local Response is distinguished from FP System Response. A 1-to-n and n-to- 1 mapping is established among Monitors, Symptoms, and Responses. Responses are categorized by device versus by function. Responses operate in tiers, where the early tiers attempt to resolve the Fault in a localized step-by-step fashion, relegating more system-level response to later tier(s). Recovery actions are gated by epoch recovery timing, enabling strategy, urgency, MaxRetry gate, hardware availability, hazardous versus ordinary fault, and many other priority gates. This methodology is systematic, logical, and uses multiple linked tables, parameter files, and recovery command sequences. The credibility of the FP design is proven via a fault-tree analysis "top-down" approach, and a functional fault-mode-effects-and-analysis via "bottoms-up" approach. Via this process, the mitigation and recovery strategy(s) per Fault Containment Region scope (width versus depth) the FP architecture.

  20. Systematic Comparison of Operating Reserve Methodologies: Preprint

    SciTech Connect

    Ibanez, E.; Krad, I.; Ela, E.

    2014-04-01

    Operating reserve requirements are a key component of modern power systems, and they contribute to maintaining reliable operations with minimum economic impact. No universal method exists for determining reserve requirements, thus there is a need for a thorough study and performance comparison of the different existing methodologies. Increasing penetrations of variable generation (VG) on electric power systems are posed to increase system uncertainty and variability, thus the need for additional reserve also increases. This paper presents background information on operating reserve and its relationship to VG. A consistent comparison of three methodologies to calculate regulating and flexibility reserve in systems with VG is performed.

  1. Methodological quality of systematic reviews on influenza vaccination.

    PubMed

    Remschmidt, Cornelius; Wichmann, Ole; Harder, Thomas

    2014-03-26

    There is a growing body of evidence on the risks and benefits of influenza vaccination in various target groups. Systematic reviews are of particular importance for policy decisions. However, their methodological quality can vary considerably. To investigate the methodological quality of systematic reviews on influenza vaccination (efficacy, effectiveness, safety) and to identify influencing factors. A systematic literature search on systematic reviews on influenza vaccination was performed, using MEDLINE, EMBASE and three additional databases (1990-2013). Review characteristics were extracted and the methodological quality of the reviews was evaluated using the assessment of multiple systematic reviews (AMSTAR) tool. U-test, Kruskal-Wallis test, chi-square test, and multivariable linear regression analysis were used to assess the influence of review characteristics on AMSTAR-score. Fourty-six systematic reviews fulfilled the inclusion criteria. Average methodological quality was high (median AMSTAR-score: 8), but variability was large (AMSTAR range: 0-11). Quality did not differ significantly according to vaccination target group. Cochrane reviews had higher methodological quality than non-Cochrane reviews (p=0.001). Detailed analysis showed that this was due to better study selection and data extraction, inclusion of unpublished studies, and better reporting of study characteristics (all p<0.05). In the adjusted analysis, no other factor, including industry sponsorship or journal impact factor had an influence on AMSTAR score. Systematic reviews on influenza vaccination showed large differences regarding their methodological quality. Reviews conducted by the Cochrane collaboration were of higher quality than others. When using systematic reviews to guide the development of vaccination recommendations, the methodological quality of a review in addition to its content should be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Reliability based design optimization: Formulations and methodologies

    NASA Astrophysics Data System (ADS)

    Agarwal, Harish

    Modern products ranging from simple components to complex systems should be designed to be optimal and reliable. The challenge of modern engineering is to ensure that manufacturing costs are reduced and design cycle times are minimized while achieving requirements for performance and reliability. If the market for the product is competitive, improved quality and reliability can generate very strong competitive advantages. Simulation based design plays an important role in designing almost any kind of automotive, aerospace, and consumer products under these competitive conditions. Single discipline simulations used for analysis are being coupled together to create complex coupled simulation tools. This investigation focuses on the development of efficient and robust methodologies for reliability based design optimization in a simulation based design environment. Original contributions of this research are the development of a novel efficient and robust unilevel methodology for reliability based design optimization, the development of an innovative decoupled reliability based design optimization methodology, the application of homotopy techniques in unilevel reliability based design optimization methodology, and the development of a new framework for reliability based design optimization under epistemic uncertainty. The unilevel methodology for reliability based design optimization is shown to be mathematically equivalent to the traditional nested formulation. Numerical test problems show that the unilevel methodology can reduce computational cost by at least 50% as compared to the nested approach. The decoupled reliability based design optimization methodology is an approximate technique to obtain consistent reliable designs at lesser computational expense. Test problems show that the methodology is computationally efficient compared to the nested approach. A framework for performing reliability based design optimization under epistemic uncertainty is also developed

  3. A Systematic Methodology for Verifying Superscalar Microprocessors

    NASA Technical Reports Server (NTRS)

    Srivas, Mandayam; Hosabettu, Ravi; Gopalakrishnan, Ganesh

    1999-01-01

    We present a systematic approach to decompose and incrementally build the proof of correctness of pipelined microprocessors. The central idea is to construct the abstraction function by using completion functions, one per unfinished instruction, each of which specifies the effect (on the observables) of completing the instruction. In addition to avoiding the term size and case explosion problem that limits the pure flushing approach, our method helps localize errors, and also handles stages with interactive loops. The technique is illustrated on pipelined and superscalar pipelined implementations of a subset of the DLX architecture. It has also been applied to a processor with out-of-order execution.

  4. Nonlinear flight control design using backstepping methodology

    NASA Astrophysics Data System (ADS)

    Tran, Thanh Trung

    The subject of nonlinear flight control design using backstepping control methodology is investigated in the dissertation research presented here. Control design methods based on nonlinear models of the dynamic system provide higher utility and versatility because the design model more closely matches the physical system behavior. Obtaining requisite model fidelity is only half of the overall design process, however. Design of the nonlinear control loops can lessen the effects of nonlinearity, or even exploit nonlinearity, to achieve higher levels of closed-loop stability, performance, and robustness. The goal of the research is to improve control quality for a general class of strict-feedback dynamic systems and provide flight control architectures to augment the aircraft motion. The research is divided into two parts: theoretical control development for the strict-feedback form of nonlinear dynamic systems and application of the proposed theory for nonlinear flight dynamics. In the first part, the research is built on two components: transforming the nonlinear dynamic model to a canonical strict-feedback form and then applying backstepping control theory to the canonical model. The research considers a process to determine when this transformation is possible, and when it is possible, a systematic process to transfer the model is also considered when practical. When this is not the case, certain modeling assumptions are explored to facilitate the transformation. After achieving the canonical form, a systematic design procedure for formulating a backstepping control law is explored in the research. Starting with the simplest subsystem and ending with the full system, pseudo control concepts based on Lyapunov control functions are used to control each successive subsystem. Typically each pseudo control must be solved from a nonlinear algebraic equation. At the end of this process, the physical control input must be re-expressed in terms of the physical states by

  5. Integrated Design Methodology for Highly Reliable Liquid Rocket Engine

    NASA Astrophysics Data System (ADS)

    Kuratani, Naoshi; Aoki, Hiroshi; Yasui, Masaaki; Kure, Hirotaka; Masuya, Goro

    The Integrated Design Methodology is strongly required at the conceptual design phase to achieve the highly reliable space transportation systems, especially the propulsion systems, not only in Japan but also all over the world in these days. Because in the past some catastrophic failures caused some losses of mission and vehicle (LOM/LOV) at the operational phase, moreover did affect severely the schedule delays and cost overrun at the later development phase. Design methodology for highly reliable liquid rocket engine is being preliminarily established and investigated in this study. The sensitivity analysis is systematically performed to demonstrate the effectiveness of this methodology, and to clarify and especially to focus on the correlation between the combustion chamber, turbopump and main valve as main components. This study describes the essential issues to understand the stated correlations, the need to apply this methodology to the remaining critical failure modes in the whole engine system, and the perspective on the engine development in the future.

  6. Space Engineering Projects in Design Methodology

    NASA Technical Reports Server (NTRS)

    Crawford, R.; Wood, K.; Nichols, S.; Hearn, C.; Corrier, S.; DeKunder, G.; George, S.; Hysinger, C.; Johnson, C.; Kubasta, K.

    1993-01-01

    NASA/USRA is an ongoing sponsor of space design projects in the senior design courses of the Mechanical Engineering Department at The University of Texas at Austin. This paper describes the UT senior design sequence, focusing on the first-semester design methodology course. The philosophical basis and pedagogical structure of this course is summarized. A history of the Department's activities in the Advanced Design Program is then presented. The paper includes a summary of the projects completed during the 1992-93 Academic Year in the methodology course, and concludes with an example of two projects completed by student design teams.

  7. Space Engineering Projects in Design Methodology

    NASA Technical Reports Server (NTRS)

    Crawford, R.; Wood, K.; Nichols, S.; Hearn, C.; Corrier, S.; DeKunder, G.; George, S.; Hysinger, C.; Johnson, C.; Kubasta, K.

    1993-01-01

    NASA/USRA is an ongoing sponsor of space design projects in the senior design courses of the Mechanical Engineering Department at The University of Texas at Austin. This paper describes the UT senior design sequence, focusing on the first-semester design methodology course. The philosophical basis and pedagogical structure of this course is summarized. A history of the Department's activities in the Advanced Design Program is then presented. The paper includes a summary of the projects completed during the 1992-93 Academic Year in the methodology course, and concludes with an example of two projects completed by student design teams.

  8. Assuring data transparency through design methodologies

    NASA Technical Reports Server (NTRS)

    Williams, Allen

    1990-01-01

    This paper addresses the role of design methodologies and practices in the assurance of technology transparency. The development of several subsystems on large, long life cycle government programs was analyzed to glean those characteristics in the design, development, test, and evaluation that precluded or enabled the insertion of new technology. The programs examined were Minuteman, DSP, B1-B, and space shuttle. All these were long life cycle, technology-intensive programs. The design methodologies (or lack thereof) and design practices for each were analyzed in terms of the success or failure in incorporating evolving technology. Common elements contributing to the success or failure were extracted and compared to current methodologies being proposed by the Department of Defense and NASA. The relevance of these practices to the design and deployment of Space Station Freedom were evaluated. In particular, appropriate methodologies now being used on the core development contract were examined.

  9. Assuring data transparency through design methodologies

    NASA Technical Reports Server (NTRS)

    Williams, Allen

    1990-01-01

    This paper addresses the role of design methodologies and practices in the assurance of technology transparency. The development of several subsystems on large, long life cycle government programs was analyzed to glean those characteristics in the design, development, test, and evaluation that precluded or enabled the insertion of new technology. The programs examined were Minuteman, DSP, B1-B, and space shuttle. All these were long life cycle, technology-intensive programs. The design methodologies (or lack thereof) and design practices for each were analyzed in terms of the success or failure in incorporating evolving technology. Common elements contributing to the success or failure were extracted and compared to current methodologies being proposed by the Department of Defense and NASA. The relevance of these practices to the design and deployment of Space Station Freedom were evaluated. In particular, appropriate methodologies now being used on the core development contract were examined.

  10. Methodologic Quality of Systematic Reviews Published in the Plastic and Reconstructive Surgery Literature: A Systematic Review.

    PubMed

    Samargandi, Osama A; Hasan, Haroon; Thoma, Achilleas

    2016-01-01

    Well-conducted systematic reviews have a critical role in informing evidence-based decision-making in plastic surgery. The authors' objective was to assess the methodologic quality of systematic reviews in the plastic surgery literature. The authors systematically assessed all systematic reviews in 10 high-impact plastic surgery journals using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from 2003 to 2013. These were evaluated for methodologic quality using A Measurement Tool to Assess Systematic Reviews (AMSTAR), a validated 11-point instrument. After removal of duplicates and screening titles and abstracts, 190 systematic reviews met eligibility criteria. The majority of systematic reviews were published in Plastic and Reconstructive Surgery (n = 88). The most common domain covered was reconstruction (17.9 percent). Using AMSTAR, the median score was 4 (interquartile range, 2.25 to 6.00) on a scale of 1 to 11. No increase in AMSTAR score was observed with time (p = 0.18). Almost half of all systematic reviews (48.4 percent) included at least two independent data extractors, and less than one-third of them (15.3 percent) searched unpublished studies or provided a list of both included and excluded studies (14.8 percent). The methodologic quality of included primary studies was evaluated in 35.3 percent. Systematic reviews in plastic surgery demonstrated inadequate adherence to methodologic standards of quality, which raises concerns about validity. There has been an increase in the number of systematic reviews published in plastic surgery over the past decade, yet there has been no significant improvement observed in methodologic quality.

  11. General Methodology for Designing Spacecraft Trajectories

    NASA Technical Reports Server (NTRS)

    Condon, Gerald; Ocampo, Cesar; Mathur, Ravishankar; Morcos, Fady; Senent, Juan; Williams, Jacob; Davis, Elizabeth C.

    2012-01-01

    A methodology for designing spacecraft trajectories in any gravitational environment within the solar system has been developed. The methodology facilitates modeling and optimization for problems ranging from that of a single spacecraft orbiting a single celestial body to that of a mission involving multiple spacecraft and multiple propulsion systems operating in gravitational fields of multiple celestial bodies. The methodology consolidates almost all spacecraft trajectory design and optimization problems into a single conceptual framework requiring solution of either a system of nonlinear equations or a parameter-optimization problem with equality and/or inequality constraints.

  12. Economic Studies in Motor Neurone Disease: A Systematic Methodological Review.

    PubMed

    Moore, Alan; Young, Carolyn A; Hughes, Dyfrig A

    2017-04-01

    Motor neurone disease (MND) is a devastating condition which greatly diminishes patients' quality of life and limits life expectancy. Health technology appraisals of future interventions in MND need robust data on costs and utilities. Existing economic evaluations have been noted to be limited and fraught with challenges. The aim of this study was to identify and critique methodological aspects of all published economic evaluations, cost studies, and utility studies in MND. We systematically reviewed all relevant published studies in English from 1946 until January 2016, searching the databases of Medline, EMBASE, Econlit, NHS Economic Evaluation Database (NHS EED) and the Health Economics Evaluation Database (HEED). Key data were extracted and synthesised narratively. A total of 1830 articles were identified, of which 15 economic evaluations, 23 cost and 3 utility studies were included. Most economic studies focused on riluzole (n = 9). Six studies modelled the progressive decline in motor function using a Markov design but did not include mutually exclusive health states. Cost estimates for a number of evaluations were based on expert opinion and were hampered by high variability and location-specific characteristics. Few cost studies reported disease-stage-specific costs (n = 3) or fully captured indirect costs. Utilities in three studies of MND patients used the EuroQol EQ-5D questionnaire or standard gamble, but included potentially unrepresentative cohorts and did not consider any health impacts on caregivers. Economic evaluations in MND suffer from significant methodological issues such as a lack of data, uncertainty with the disease course and use of inappropriate modelling framework. Limitations may be addressed through the collection of detailed and representative data from large cohorts of patients.

  13. A new methodology for hospital design.

    PubMed

    Mejia, Ana Maria Silva

    2013-08-01

    According to architect, Ana Maria Silva Mejia, 'a new era for the design of hospitals in Guatemala has arrived', with a considerable growth in interest around good healthcare facility design. Here, in a slightly adapted version of an article, 'A new methodology for design', first published in the IFHE (International Federation of Hospital Engineering) Digest 2012, she reports on the application of a new methodology designed to optimise efficient use of space, and clinical and other adjacencies, in a district hospital in the City of Zacapa. The system has subsequently been successfully applied to a number of other Guatemalan healthcare facilities.

  14. Applying Software Design Methodology to Instructional Design

    ERIC Educational Resources Information Center

    East, J. Philip

    2004-01-01

    The premise of this paper is that computer science has much to offer the endeavor of instructional improvement. Software design processes employed in computer science for developing software can be used for planning instruction and should improve instruction in much the same manner that design processes appear to have improved software. Techniques…

  15. Poor methodological quality and reporting standards of systematic reviews in burn care management.

    PubMed

    Wasiak, Jason; Tyack, Zephanie; Ware, Robert; Goodwin, Nicholas; Faggion, Clovis M

    2016-12-18

    The methodological and reporting quality of burn-specific systematic reviews has not been established. The aim of this study was to evaluate the methodological quality of systematic reviews in burn care management. Computerised searches were performed in Ovid MEDLINE, Ovid EMBASE and The Cochrane Library through to February 2016 for systematic reviews relevant to burn care using medical subject and free-text terms such as 'burn', 'systematic review' or 'meta-analysis'. Additional studies were identified by hand-searching five discipline-specific journals. Two authors independently screened papers, extracted and evaluated methodological quality using the 11-item A Measurement Tool to Assess Systematic Reviews (AMSTAR) tool and reporting quality using the 27-item Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Characteristics of systematic reviews associated with methodological and reporting quality were identified. Descriptive statistics and linear regression identified features associated with improved methodological quality. A total of 60 systematic reviews met the inclusion criteria. Six of the 11 AMSTAR items reporting on 'a priori' design, duplicate study selection, grey literature, included/excluded studies, publication bias and conflict of interest were reported in less than 50% of the systematic reviews. Of the 27 items listed for PRISMA, 13 items reporting on introduction, methods, results and the discussion were addressed in less than 50% of systematic reviews. Multivariable analyses showed that systematic reviews associated with higher methodological or reporting quality incorporated a meta-analysis (AMSTAR regression coefficient 2.1; 95% CI: 1.1, 3.1; PRISMA regression coefficient 6·3; 95% CI: 3·8, 8·7) were published in the Cochrane library (AMSTAR regression coefficient 2·9; 95% CI: 1·6, 4·2; PRISMA regression coefficient 6·1; 95% CI: 3·1, 9·2) and included a randomised control trial (AMSTAR regression

  16. Electronic Assisted Living Technology: Interim Systematic Review Results - The Evidence for Creative Methodologies.

    PubMed

    Holliday, Nikki; Moody, Louise; Ward, Gillian

    2017-01-01

    Despite reported benefits of creative methodologies for the design and development of electronic Assisted Living Technologies (eALT), there exists a divide between design and health research, leaving health researchers wishing to pursue creative methods uninformed with regards choice of appropriate methods. This paper describes interim and emerging results from a systematic review which aimed to explore the value of creative methodologies for the design and development of eALT which may form part of the solution to the challenges of the ageing population.

  17. Design methodology and projects for space engineering

    NASA Technical Reports Server (NTRS)

    Nichols, S.; Kleespies, H.; Wood, K.; Crawford, R.

    1993-01-01

    NASA/USRA is an ongoing sponsor of space design projects in the senior design course of the Mechanical Engineering Department at The University of Texas at Austin. This paper describes the UT senior design sequence, consisting of a design methodology course and a capstone design course. The philosophical basis of this sequence is briefly summarized. A history of the Department's activities in the Advanced Design Program is then presented. The paper concludes with a description of the projects completed during the 1991-92 academic year and the ongoing projects for the Fall 1992 semester.

  18. Design methodology and projects for space engineering

    NASA Technical Reports Server (NTRS)

    Nichols, S.; Kleespies, H.; Wood, K.; Crawford, R.

    1993-01-01

    NASA/USRA is an ongoing sponsor of space design projects in the senior design course of the Mechanical Engineering Department at The University of Texas at Austin. This paper describes the UT senior design sequence, consisting of a design methodology course and a capstone design course. The philosophical basis of this sequence is briefly summarized. A history of the Department's activities in the Advanced Design Program is then presented. The paper concludes with a description of the projects completed during the 1991-92 academic year and the ongoing projects for the Fall 1992 semester.

  19. Integrating rock mechanics issues with repository design through design process principles and methodology

    SciTech Connect

    Bieniawski, Z.T.

    1996-04-01

    A good designer needs not only knowledge for designing (technical know-how that is used to generate alternative design solutions) but also must have knowledge about designing (appropriate principles and systematic methodology to follow). Concepts such as {open_quotes}design for manufacture{close_quotes} or {open_quotes}concurrent engineering{close_quotes} are widely used in the industry. In the field of rock engineering, only limited attention has been paid to the design process because design of structures in rock masses presents unique challenges to the designers as a result of the uncertainties inherent in characterization of geologic media. However, a stage has now been reached where we are be able to sufficiently characterize rock masses for engineering purposes and identify the rock mechanics issues involved but are still lacking engineering design principles and methodology to maximize our design performance. This paper discusses the principles and methodology of the engineering design process directed to integrating site characterization activities with design, construction and performance of an underground repository. Using the latest information from the Yucca Mountain Project on geology, rock mechanics and starter tunnel design, the current lack of integration is pointed out and it is shown how rock mechanics issues can be effectively interwoven with repository design through a systematic design process methodology leading to improved repository performance. In essence, the design process is seen as the use of design principles within an integrating design methodology, leading to innovative problem solving. In particular, a new concept of {open_quotes}Design for Constructibility and Performance{close_quotes} is introduced. This is discussed with respect to ten rock mechanics issues identified for repository design and performance.

  20. Failure detection system design methodology. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Chow, E. Y.

    1980-01-01

    The design of a failure detection and identification system consists of designing a robust residual generation process and a high performance decision making process. The design of these two processes are examined separately. Residual generation is based on analytical redundancy. Redundancy relations that are insensitive to modelling errors and noise effects are important for designing robust residual generation processes. The characterization of the concept of analytical redundancy in terms of a generalized parity space provides a framework in which a systematic approach to the determination of robust redundancy relations are developed. The Bayesian approach is adopted for the design of high performance decision processes. The FDI decision problem is formulated as a Bayes sequential decision problem. Since the optimal decision rule is incomputable, a methodology for designing suboptimal rules is proposed. A numerical algorithm is developed to facilitate the design and performance evaluation of suboptimal rules.

  1. Waste Package Component Design Methodology Report

    SciTech Connect

    D.C. Mecham

    2004-07-12

    This Executive Summary provides an overview of the methodology being used by the Yucca Mountain Project (YMP) to design waste packages and ancillary components. This summary information is intended for readers with general interest, but also provides technical readers a general framework surrounding a variety of technical details provided in the main body of the report. The purpose of this report is to document and ensure appropriate design methods are used in the design of waste packages and ancillary components (the drip shields and emplacement pallets). The methodology includes identification of necessary design inputs, justification of design assumptions, and use of appropriate analysis methods, and computational tools. This design work is subject to ''Quality Assurance Requirements and Description''. The document is primarily intended for internal use and technical guidance for a variety of design activities. It is recognized that a wide audience including project management, the U.S. Department of Energy (DOE), the U.S. Nuclear Regulatory Commission, and others are interested to various levels of detail in the design methods and therefore covers a wide range of topics at varying levels of detail. Due to the preliminary nature of the design, readers can expect to encounter varied levels of detail in the body of the report. It is expected that technical information used as input to design documents will be verified and taken from the latest versions of reference sources given herein. This revision of the methodology report has evolved with changes in the waste package, drip shield, and emplacement pallet designs over many years and may be further revised as the design is finalized. Different components and analyses are at different stages of development. Some parts of the report are detailed, while other less detailed parts are likely to undergo further refinement. The design methodology is intended to provide designs that satisfy the safety and operational

  2. Application of systematic review methodology to the field of nutrition.

    PubMed

    Lichtenstein, Alice H; Yetley, Elizabeth A; Lau, Joseph

    2008-12-01

    Systematic reviews represent a rigorous and transparent approach to synthesizing scientific evidence that minimizes bias. They evolved within the medical community to support development of clinical and public health practice guidelines, set research agendas, and formulate scientific consensus statements. The use of systematic reviews for nutrition-related topics is more recent. Systematic reviews provide independently conducted comprehensive and objective assessments of available information addressing precise questions. This approach to summarizing available data is a useful tool for identifying the state of science including knowledge gaps and associated research needs, supporting development of science-based recommendations and guidelines, and serving as the foundation for updates as new data emerge. Our objective is to describe the steps for performing systematic reviews and highlight areas unique to the discipline of nutrition that are important to consider in data assessment. The steps involved in generating systematic reviews include identifying staffing and planning for outside expert input, forming a research team, developing an analytic framework, developing and refining research questions, defining eligibility criteria, identifying search terms, screening abstracts according to eligibility criteria, retrieving articles for evaluation, constructing evidence and summary tables, assessing methodological quality and applicability, and synthesizing results including performing meta-analysis, if appropriate. Unique and at times challenging, nutrition-related considerations include baseline nutrient exposure, nutrient status, bioequivalence of bioactive compounds, bioavailability, multiple and interrelated biological functions, undefined nature of some interventions, and uncertainties in intake assessment. Systematic reviews are a valuable and independent component of decision-making processes by groups responsible for developing science-based recommendations

  3. Hardware design methodology for efficient reuse

    SciTech Connect

    Seepold, R.; Kunzmann, A.; Rosenstiel, W.

    1996-12-31

    The approach presented offers a design methodology for efficient reuse that is based on a Reuse Management System (RMS) and a detailed analysis of component reuse. After the presentation of the current level of work being done in this field, RMS is introduced and a basic model is shown to describe fundamental mechanisms before design for reuse techniques can be introduced. In contrast to conventional reuse approaches, which are restricted to specific support, this new approach bridges the gap between design and reuse integration. The new methodology incorporates RMS requirements and it achieves several initial targets requested for a powerful system to provide comprehensive reuse. Based on the object-oriented internal data model and the sketched architecture, easy access via common Internet services is offered, and therefore, quick access to reuse data is possible. In summary, the approach helps to reduce long term development costs, and therefore, it is an innovative way to reach the objectives of efficient cost management.

  4. Performance-based asphalt mixture design methodology

    NASA Astrophysics Data System (ADS)

    Ali, Al-Hosain Mansour

    Today, several State D.O.T.s are being investigating the use of tire rubber with local conventional materials. Several of the ongoing investigations identified potential benefits from the use of these materials, including improvements in material properties and performance. One of the major problems is being associated with the transferability of asphalt rubber technology without appropriately considering the effects of the variety of conventional materials on mixture behavior and performance. Typically, the design of these mixtures is being adapted to the physical properties of the conventional materials by using the empirical Marshall mixture design and without considering fundamental mixture behavior and performance. Use of design criteria related to the most common modes of failure for asphalt mixtures, such as rutting, fatigue cracking, and low temperature thermal cracking have to be developed and used for identifying the "best mixture," in term of performance, for the specific local materials and loading conditions. The main objective of this study was the development of a mixture design methodology that considers mixture behavior and performance. In order to achieve this objective a laboratory investigation able to evaluate mixture properties that can be related to mixture performance, (in terms of rutting, low temperature cracking, moisture damage and fatigue), and simulating the actual field loading conditions that the material is being exposed to, was conducted. The results proved that the inclusion of rubber into asphalt mixtures improved physical characteristics such as elasticity, flexibility, rebound, aging properties, increased fatigue resistance, and reduced rutting potential. The possibility of coupling the traditional Marshall mix design method with parameters related to mixture behavior and performance was investigated. Also, the SHRP SUPERPAVE mix design methodology was reviewed and considered in this study for the development of an integrated

  5. Methodological considerations for designing a community water fluoridation cessation study.

    PubMed

    Singhal, Sonica; Farmer, Julie; McLaren, Lindsay

    2017-02-22

    High-quality, up-to-date research on community water fluoridation (CWF), and especially on the implications of CWF cessation for dental health, is limited. Although CWF cessation studies have been conducted, they are few in number; one of the major reasons is the methodological complexity of conducting such a study. This article draws on a systematic review of existing cessation studies (n=15) to explore methodological considerations of conducting CWF cessation studies in future. We review nine important methodological aspects (study design, comparison community, target population, time frame, sampling strategy, clinical indicators, assessment criteria, covariates and biomarkers) and provide recommendations for planning future CWF cessation studies that examine effects on dental caries. There is no one ideal study design to answer a research question. However, recommendations proposed regarding methodological aspects to conduct an epidemiological study to observe the effects of CWF cessation on dental caries, coupled with our identification of important methodological gaps, will be useful for researchers who are looking to optimize resources to conduct such a study with standards of rigour.

  6. An Analysis of Software Design Methodologies

    DTIC Science & Technology

    1979-08-01

    Technical Report 401-, # "AN ANALYSIS OF SOFTWARE DESIGN METHODOLOGIES H. Rudy Ramsey, Michael E. Atwood , and Gary D. Campbell Science...H. Rudy Ramsey, Michael E. Atwood , and Gary D. Campbell Science Applications, Incorporated Submitted by: Edgar M. Johnson, Chief HUMAN FACTORS...expressed by members ot the Integrated Software Research and Development Working Group (ISRAD). The authors are indebted to Martha Cichelli, Margaret

  7. CAGE IIIA Distributed Simulation Design Methodology

    DTIC Science & Technology

    2014-05-01

    Greenach Mean Time GOTS Government Off The Shelf GPS Global Positioning System GW Gate Way HD Hard Drive HICON Higher Control HOA Horn of Africa HQ...Organisation SF Special Forces SME Subject Matter Expert SOCET GXP SOCET GXP is a geospatial-intelligence software package that uses imagery...Implementing Defence Experimentation (GUIDEx). The key challenges for this methodology are with understanding how to: • design it o define the

  8. Eligibility criteria in systematic reviews published in prominent medical journals: a methodological review.

    PubMed

    McCrae, Niall; Purssell, Edward

    2015-12-01

    Clear and logical eligibility criteria are fundamental to the design and conduct of a systematic review. This methodological review examined the quality of reporting and application of eligibility criteria in systematic reviews published in three leading medical journals. All systematic reviews in the BMJ, JAMA and The Lancet in the years 2013 and 2014 were extracted. These were assessed using a refined version of a checklist previously designed by the authors. A total of 113 papers were eligible, of which 65 were in BMJ, 17 in The Lancet and 31 in JAMA. Although a generally high level of reporting was found, eligibility criteria were often problematic. In 67% of papers, eligibility was specified after the search sources or terms. Unjustified time restrictions were used in 21% of reviews, and unpublished or unspecified data in 27%. Inconsistency between journals was apparent in the requirements for systematic reviews. The quality of reviews in these leading medical journals was high; however, there were issues that reduce the clarity and replicability of the review process. As well as providing a useful checklist, this methodological review informs the continued development of standards for systematic reviews. © 2015 John Wiley & Sons, Ltd.

  9. A Design Methodology for Optoelectronic VLSI

    DTIC Science & Technology

    2007-01-01

    soldered to a copper -clad printed circuit (PC) board, are no longer sufficient for today’s high-speed ICs. A processing chip that can compute data at a rate...design approach. A new design methodology has to be adopted to take advan- tage of the benefits that FSOI offers. Optoelectronic VLSI is the coupling of...and connections are made from chip to chip via traces of copper wire, as shown in Figure 2-2. The signal from a logic gate on one chip to a logic gate

  10. Conceptual design methodology for vibration isolation

    NASA Astrophysics Data System (ADS)

    Hyde, T. Tupper

    1997-06-01

    High performance dynamic structures have strict requirements on structural motion that are emphasized by the flexibility inherent in lightweight space systems. Vibration isolation is used to prevent disturbances from affecting critical payload components where motion is to be minimized. Isolation, however, is often an engineering solution that is not properly considered in the early conceptual design of the spacecraft. It is at this key stage of a program that mission driving performance targets and resource allocations are made yet little analysis has been performed. A conceptual design methodology for isolation is developed and applied to the conceptual design of a proposed space shuttle based telescope system. In the developed methodology, frequency domain computation of the closed loop performance without isolation pinpoints frequency regimes and disturbance to performance channels targeted for improvement. A coarse fidelity structural model, with well defined disturbance and performance characterization, is more useful than a costly high fidelity analysis when evaluating the many isolation options available early in a project. Isolation design choices are made by trading their performance improvement against their complexity/cost. Simple, idealized mechanical descriptions of the passive or active isolation system provide the needed frequency domain effect on performance without the costly analysis that a detailed isolator design entails. Similarly, the effects of other integrating subsystems, such as structural or optical control are approximated by frequency domain descriptions.

  11. Structural design methodology for large space structures

    NASA Astrophysics Data System (ADS)

    Dornsife, Ralph J.

    The Department of Defense requires research and development in designing, fabricating, deploying, and maintaining large space structures (LSS) in support of Army and Strategic Defense Initiative military objectives. Because of their large size, extreme flexibility, and the unique loading conditions in the space environment, LSS will present engineers with problems unlike those encountered in designing conventional civil engineering or aerospace structures. LSS will require sophisticated passive damping and active control systems in order to meet stringent mission requirements. These structures must also be optimally designed to minimize high launch costs. This report outlines a methodology for the structural design of LSS. It includes a definition of mission requirements, structural modeling and analysis, passive damping and active control system design, ground-based testing, payload integration, on-orbit system verification, and on-orbit assessment of structural damage. In support of this methodology, analyses of candidate LSS truss configurations are presented, and an algorithm correlating ground-based test behavior to expected microgravity behavior is developed.

  12. Structural design methodology for large space structures

    NASA Astrophysics Data System (ADS)

    Dornsife, Ralph J.

    1992-02-01

    The Department of Defense requires research and development in designing, fabricating, deploying, and maintaining large space structures (LSS) in support of Army and Strategic Defense Initiative military objectives. Because of their large size, extreme flexibility, and the unique loading conditions in the space environment, LSS will present engineers with problems unlike those encountered in designing conventional civil engineering or aerospace structures. LSS will require sophisticated passive damping and active control systems in order to meet stringent mission requirements. These structures must also be optimally designed to minimize high launch costs. This report outlines a methodology for the structural design of LSS. It includes a definition of mission requirements, structural modeling and analysis, passive damping and active control system design, ground-based testing, payload integration, on-orbit system verification, and on-orbit assessment of structural damage. In support of this methodology, analyses of candidate LSS truss configurations are presented, and an algorithm correlating ground-based test behavior to expected microgravity behavior is developed.

  13. Control/structure interaction design methodology

    NASA Technical Reports Server (NTRS)

    Briggs, Hugh C.; Layman, William E.

    1989-01-01

    The Control Structure Interaction Program is a technology development program for spacecraft that exhibit interactions between the control system and structural dynamics. The program objectives include development and verification of new design concepts (such as active structure) and new tools (such as a combined structure and control optimization algorithm) and their verification in ground and possibly flight test. The new CSI design methodology is centered around interdisciplinary engineers using new tools that closely integrate structures and controls. Verification is an important CSI theme and analysts will be closely integrated to the CSI Test Bed laboratory. Components, concepts, tools and algorithms will be developed and tested in the lab and in future Shuttle-based flight experiments. The design methodology is summarized in block diagrams depicting the evolution of a spacecraft design and descriptions of analytical capabilities used in the process. The multiyear JPL CSI implementation plan is described along with the essentials of several new tools. A distributed network of computation servers and workstations was designed that will provide a state-of-the-art development base for the CSI technologies.

  14. Saving Material with Systematic Process Designs

    NASA Astrophysics Data System (ADS)

    Kerausch, M.

    2011-08-01

    Global competition is forcing the stamping industry to further increase quality, to shorten time-to-market and to reduce total cost. Continuous balancing between these classical time-cost-quality targets throughout the product development cycle is required to ensure future economical success. In today's industrial practice, die layout standards are typically assumed to implicitly ensure the balancing of company specific time-cost-quality targets. Although die layout standards are a very successful approach, there are two methodical disadvantages. First, the capabilities for tool design have to be continuously adapted to technological innovations; e.g. to take advantage of the full forming capability of new materials. Secondly, the great variety of die design aspects have to be reduced to a generic rule or guideline; e.g. binder shape, draw-in conditions or the use of drawbeads. Therefore, it is important to not overlook cost or quality opportunities when applying die design standards. This paper describes a systematic workflow with focus on minimizing material consumption. The starting point of the investigation is a full process plan for a typical structural part. All requirements are definedaccording to a predefined set of die design standards with industrial relevance are fulfilled. In a first step binder and addendum geometry is systematically checked for material saving potentials. In a second step, blank shape and draw-in are adjusted to meet thinning, wrinkling and springback targets for a minimum blank solution. Finally the identified die layout is validated with respect to production robustness versus splits, wrinkles and springback. For all three steps the applied methodology is based on finite element simulation combined with a stochastical variation of input variables. With the proposed workflow a well-balanced (time-cost-quality) production process assuring minimal material consumption can be achieved.

  15. Experimental design methodology: the scientific tool for performance evaluation

    NASA Astrophysics Data System (ADS)

    Sadjadi, Firooz A.

    1990-09-01

    With the rapid growth of the signal and image processing technology in the last several decades has arisen the need for means of evaluating and comparing the numerous algorithms and systems that are created or are being developed. Performance evaluation, in the past, has been mostly ad hoc and incohesive. In this paper we present a systematic step by step approach for the scientific evaluation of signal and image processing algorithms and systems. This approach is based on the methodology of Experimental Design. We illustrate this method by means of an example from the field of automatic object recognition.

  16. Chinese herbal medicine for the treatment of primary hypertension: a methodology overview of systematic reviews.

    PubMed

    Xinke, Zhao; Yingdong, Li; Mingxia, Feng; Kai, Liu; Kaibing, Chen; Yuqing, Lu; Shaobo, Sun; Peng, Song; Bin, Liu

    2016-10-20

    Chinese herbal medicine has been used to treat hypertension in China and East Asia since centuries. In this study, we conduct an overview of systematic reviews of Chinese herbal medicine in the treatment of primary hypertension to 1) summarize the conclusions of these reviews, 2) evaluate the methodological quality of these reviews, and 3) rate the confidence in the effect on each outcome. We comprehensively searched six databases to retrieve systematic reviews of Chinese herbal medicine for primary hypertension from inception to December 31, 2015. We used AMSTAR to evaluate the methodological quality of included reviews, and we classified the quality of evidence for each outcome in included reviews using the GRADE approach. A total of 12 systematic reviews with 31 outcomes were included, among which 11 systematic reviews focus on the therapeutic effect of Chinese herbal medicine combined with conventional medicine or simple Chinese herbal medicine versus simple conventional medicine. Among the 11 items of AMSTAR, the lowest quality was "providing a priori design" item, none review conformed to this item, the next was "stating the conflict of interest" item, only three reviews conformed to this item. Five reviews scored less than seven in AMSTAR, which means that the overall methodological quality was fairly poor. For GRADE, of the 31 outcomes, the quality of evidence was high in none (0 %), moderate in three (10 %), low in 19 (61 %), and very low in nine (29 %). Of the five downgrading factors, risk of bias (100 %) was the most common downgrading factor in the included reviews, followed by imprecision (42 %), inconsistency (39 %), publication bias (39 %), and indirectness (0 %). The methodological quality of systematic reviews about Chinese herbal medicine for primary hypertension is fairly poor, and the quality of evidence level is low. Physicians should be cautious when applying the interventions in these reviews for primary hypertension patients in

  17. Searching for qualitative research for inclusion in systematic reviews: a structured methodological review.

    PubMed

    Booth, Andrew

    2016-05-04

    Qualitative systematic reviews or qualitative evidence syntheses (QES) are increasingly recognised as a way to enhance the value of systematic reviews (SRs) of clinical trials. They can explain the mechanisms by which interventions, evaluated within trials, might achieve their effect. They can investigate differences in effects between different population groups. They can identify which outcomes are most important to patients, carers, health professionals and other stakeholders. QES can explore the impact of acceptance, feasibility, meaningfulness and implementation-related factors within a real world setting and thus contribute to the design and further refinement of future interventions. To produce valid, reliable and meaningful QES requires systematic identification of relevant qualitative evidence. Although the methodologies of QES, including methods for information retrieval, are well-documented, little empirical evidence exists to inform their conduct and reporting. This structured methodological overview examines papers on searching for qualitative research identified from the Cochrane Qualitative and Implementation Methods Group Methodology Register and from citation searches of 15 key papers. A single reviewer reviewed 1299 references. Papers reporting methodological guidance, use of innovative methodologies or empirical studies of retrieval methods were categorised under eight topical headings: overviews and methodological guidance, sampling, sources, structured questions, search procedures, search strategies and filters, supplementary strategies and standards. This structured overview presents a contemporaneous view of information retrieval for qualitative research and identifies a future research agenda. This review concludes that poor empirical evidence underpins current information practice in information retrieval of qualitative research. A trend towards improved transparency of search methods and further evaluation of key search procedures offers

  18. Sketching Designs Using the Five Design-Sheet Methodology.

    PubMed

    Roberts, Jonathan C; Headleand, Chris; Ritsos, Panagiotis D

    2016-01-01

    Sketching designs has been shown to be a useful way of planning and considering alternative solutions. The use of lo-fidelity prototyping, especially paper-based sketching, can save time, money and converge to better solutions more quickly. However, this design process is often viewed to be too informal. Consequently users do not know how to manage their thoughts and ideas (to first think divergently, to then finally converge on a suitable solution). We present the Five Design Sheet (FdS) methodology. The methodology enables users to create information visualization interfaces through lo-fidelity methods. Users sketch and plan their ideas, helping them express different possibilities, think through these ideas to consider their potential effectiveness as solutions to the task (sheet 1); they create three principle designs (sheets 2,3 and 4); before converging on a final realization design that can then be implemented (sheet 5). In this article, we present (i) a review of the use of sketching as a planning method for visualization and the benefits of sketching, (ii) a detailed description of the Five Design Sheet (FdS) methodology, and (iii) an evaluation of the FdS using the System Usability Scale, along with a case-study of its use in industry and experience of its use in teaching.

  19. Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards

    ERIC Educational Resources Information Center

    Smith, Justin D.

    2012-01-01

    This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have…

  20. Case-Crossover Analysis of Air Pollution Health Effects: A Systematic Review of Methodology and Application

    PubMed Central

    Carracedo-Martínez, Eduardo; Taracido, Margarita; Tobias, Aurelio; Saez, Marc; Figueiras, Adolfo

    2010-01-01

    Background Case-crossover is one of the most used designs for analyzing the health-related effects of air pollution. Nevertheless, no one has reviewed its application and methodology in this context. Objective We conducted a systematic review of case-crossover (CCO) designs used to study the relationship between air pollution and morbidity and mortality, from the standpoint of methodology and application. Data sources and extraction A search was made of the MEDLINE and EMBASE databases. Reports were classified as methodologic or applied. From the latter, the following information was extracted: author, study location, year, type of population (general or patients), dependent variable(s), independent variable(s), type of CCO design, and whether effect modification was analyzed for variables at the individual level. Data synthesis The review covered 105 reports that fulfilled the inclusion criteria. Of these, 24 addressed methodological aspects, and the remainder involved the design’s application. In the methodological reports, the designs that yielded the best results in simulation were symmetric bidirectional CCO and time-stratified CCO. Furthermore, we observed an increase across time in the use of certain CCO designs, mainly symmetric bidirectional and time-stratified CCO. The dependent variables most frequently analyzed were those relating to hospital morbidity; the pollutants most often studied were those linked to particulate matter. Among the CCO-application reports, 13.6% studied effect modification for variables at the individual level. Conclusions The use of CCO designs has undergone considerable growth; the most widely used designs were those that yielded better results in simulation studies: symmetric bidirectional and time-stratified CCO. However, the advantages of CCO as a method of analysis of variables at the individual level are put to little use. PMID:20356818

  1. Methodology in conducting a systematic review of systematic reviews of healthcare interventions

    PubMed Central

    2011-01-01

    Background Hundreds of studies of maternity care interventions have been published, too many for most people involved in providing maternity care to identify and consider when making decisions. It became apparent that systematic reviews of individual studies were required to appraise, summarise and bring together existing studies in a single place. However, decision makers are increasingly faced by a plethora of such reviews and these are likely to be of variable quality and scope, with more than one review of important topics. Systematic reviews (or overviews) of reviews are a logical and appropriate next step, allowing the findings of separate reviews to be compared and contrasted, providing clinical decision makers with the evidence they need. Methods The methods used to identify and appraise published and unpublished reviews systematically, drawing on our experiences and good practice in the conduct and reporting of systematic reviews are described. The process of identifying and appraising all published reviews allows researchers to describe the quality of this evidence base, summarise and compare the review's conclusions and discuss the strength of these conclusions. Results Methodological challenges and possible solutions are described within the context of (i) sources, (ii) study selection, (iii) quality assessment (i.e. the extent of searching undertaken for the reviews, description of study selection and inclusion criteria, comparability of included studies, assessment of publication bias and assessment of heterogeneity), (iv) presentation of results, and (v) implications for practice and research. Conclusion Conducting a systematic review of reviews highlights the usefulness of bringing together a summary of reviews in one place, where there is more than one review on an important topic. The methods described here should help clinicians to review and appraise published reviews systematically, and aid evidence-based clinical decision-making. PMID:21291558

  2. Importance and methodologies of endodontic microleakage studies: A systematic review

    PubMed Central

    Jafari, Farnaz

    2017-01-01

    Introduction It is very important to obtain a tight seal in obturated root canal, making it necessary to conduct clinical or laboratory studies on the sealability of endodontic materials. Different methodologies have been historically used to assess microleakage of different endodontic materials. The aim of the present study was to comprehensively review different material testing methods used in microleakage studies, their interpretation and importance in endodontic literature. Material and Methods A systematic search was conducted in Medline, Cochrane, and Web of Science databases. In addition, the reference lists of review articles on the topic were searched. No language restriction was applied. Two independent reviewers screened the article. Results Microleakage is considered the single most important risk factor responsible for apical periodontitis. Dye penetration, dye diffusion, bacterial and endototoxin infiltration, fluid filtration, glucose, caffeine and protein infiltration, radioisotope penetration, animal studies, and electrochemical or 3D evaluation are different methodologies used to assess dental leakage. 91 out of 177 articles in the primary search were included in the study. These methods are very divergent in their viewpoints; that is why their results cannot be easily compared. It is necessary to standardize microleakage detection methods in order to more correctly evaluate the phenomena that are found between the root canal wall and the root canal filling materials. Conclusions All the methods are useful if studies are performed strictly with large sample sizes and proper control groups and if the technique can be standardized. Furthermore, more evaluations of the reliability of the methods are strongly recommended. Key words:Dental leakage, review, root canal, material testing methods, data interpretation. PMID:28638561

  3. Methodological Quality Assessment of Systematic Reviews on Autologous Platelet Concentrates for the Treatment of Periodontal Defects.

    PubMed

    Del Fabbro, Massimo; Lolato, Alessandra; Panda, Saurav; Corbella, Stefano; Satpathy, Anurag; Das, Abhaya Chandra; Kumar, Manoj; Taschieri, Silvio

    2017-09-01

    Evaluation of the methodological quality of systematic reviews (SRs) on the effectiveness of autologous platelet concentrates as an adjunct to regenerative procedures for the treatment of periodontal defects. After a literature screening, eligible SRs were qualitatively assessed using 2 validated instruments: A Measurement Tool to Assess systematic Reviews checklist and Overview Quality Assessment Questionnaire. The characteristics and findings of SRs were also reported. Ten SRs fulfilled the inclusion criteria and were evaluated. With A MeaSurement Tool to Assess systematic Reviews tool, SRs displayed a generally satisfying quality. Six SRs satisfied ≥8 items of 11 (high-quality score), and 4 were classified of medium quality (score 4-7). Using Overview Quality Assessment Questionnaire instrument, more than half SRs (N = 6) satisfied ≥7 items of 9, resulting to be of high quality; 3 were classified as medium quality (4-6 criteria met); and only 1 of low quality (3 items satisfied). A significant correlation between the results of the 2 questionnaires was found (Spearman's r = 0.915, P = .0005). SRs considered had an overall high methodological quality. However, some areas were not systematically addressed, like a thorough research strategy or publication bias assessment. Standard guidelines for designing, performing, and reporting SRs should always be followed. The use of platelet concentrates as an adjunct to periodontal surgery procedures may have beneficial effects for the treatment of periodontal defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Measuring service line competitive position. A systematic methodology for hospitals.

    PubMed

    Studnicki, J

    1991-01-01

    To mount a broad effort aimed at improving their competitive position for some service or group of services, hospitals have begun to pursue product line management techniques. A few hospitals have even reorganized completely under the product line framework. The benefits include focusing accountability for operations and results, facilitating coordination between departments and functions, stimulating market segmentation, and promoting rigorous examination of new and existing programs. As part of its strategic planning process, a suburban Baltimore hospital developed a product line management methodology with six basic steps: (1) define the service lines (which they did by grouping all existing diagnosis-related groups into 35 service lines), (2) determine the contribution of each service line to total inpatient volume, (3) determine trends in service line volumes (by comparing data over time), (4) derive a useful comparison group (competing hospitals or groups of hospitals with comparable size, scope of services, payer mix, and financial status), (5) review multiple time frames, and (6) summarize the long- and short-term performance of the hospital's service lines to focus further analysis. This type of systematic and disciplined analysis can become part of a permanent strategic intelligence program. When hospitals have such a program in place, their market research, planning, budgeting, and operations will be tied together in a true management decision support system.

  5. A systematic methodology to estimate added sugar content of foods.

    PubMed

    Louie, J C Y; Moshtaghian, H; Boylan, S; Flood, V M; Rangan, A M; Barclay, A W; Brand-Miller, J C; Gill, T P

    2015-02-01

    The effect of added sugar on health is a topical area of research. However, there is currently no analytical or other method to easily distinguish between added sugars and naturally occurring sugars in foods. This study aimed to develop a systematic methodology to estimate added sugar values on the basis of analytical data and ingredients of foods. A 10-step, stepwise protocol was developed, starting with objective measures (six steps) and followed by more subjective estimation (four steps) if insufficient objective data are available. The method developed was applied to an Australian food composition database (AUSNUT2007) as an example. Out of the 3874 foods available in AUSNUT2007, 2977 foods (77%) were assigned an estimated value on the basis of objective measures (steps 1-6), and 897 (23%) were assigned a subjectively estimated value (steps 7-10). Repeatability analysis showed good repeatability for estimated values in this method. We propose that this method can be considered as a standardised approach for the estimation of added sugar content of foods to improve cross-study comparison.

  6. Unshrouded Centrifugal Turbopump Impeller Design Methodology

    NASA Technical Reports Server (NTRS)

    Prueger, George H.; Williams, Morgan; Chen, Wei-Chung; Paris, John; Williams, Robert; Stewart, Eric

    2001-01-01

    Turbopump weight continues to be a dominant parameter in the trade space for reduction of engine weight. Space Shuttle Main Engine weight distribution indicates that the turbomachinery make up approximately 30% of the total engine weight. Weight reduction can be achieved through the reduction of envelope of the turbopump. Reduction in envelope relates to an increase in turbopump speed and an increase in impeller head coefficient. Speed can be increased until suction performance limits are achieved on the pump or due to alternate constraints the turbine or bearings limit speed. Once the speed of the turbopump is set the impeller tip speed sets the minimum head coefficient of the machine. To reduce impeller diameter the head coefficient must be increased. A significant limitation with increasing head coefficient is that the slope of the head-flow characteristic is affected and this can limit engine throttling range. Unshrouded impellers offer a design option for increased turbopump speed without increasing the impeller head coefficient. However, there are several issues with regard to using an unshrouded impeller: there is a pump performance penalty due to the front open face recirculation flow, there is a potential pump axial thrust problem from the unbalanced front open face and the back shroud face, and since test data is very limited for this configuration, there is uncertainty in the magnitude and phase of the rotordynamic forces due to the front impeller passage. The purpose of the paper is to discuss the design of an unshrouded impeller and to examine the hydrodynamic performance, axial thrust, and rotordynamic performance. The design methodology will also be discussed. This work will help provide some guidelines for unshrouded impeller design.

  7. Methodologies and study designs relevant to medical education research.

    PubMed

    Turner, Teri L; Balmer, Dorene F; Coverdale, John H

    2013-06-01

    Research is an important part of educational scholarship. Knowledge of research methodologies is essential for both conducting research as well as determining the soundness of the findings from published studies. Our goals for this paper therefore are to inform medical education researchers of the range and key components of educational research designs. We will discuss both qualitative and quantitative approaches to educational research. Qualitative methods will be presented according to traditions that have a distinguished history in particular disciplines. Quantitative methods will be presented according to an evidence-based hierarchy akin to that of evidence-based medicine with the stronger designs (systematic reviews and well conducted educational randomized controlled trials) at the top, and weaker designs (descriptive studies without comparison groups, or single case studies) at the bottom. It should be appreciated, however, that the research question determines the study design. Therefore, the onus is on the researcher to choose a design that is appropriate to answering the question. We conclude with an overview of how educational researchers should describe the study design and methods in order to provide transparency and clarity.

  8. Methodological quality and reporting of systematic reviews in hand and wrist pathology.

    PubMed

    Wasiak, J; Shen, A Y; Ware, R; O'Donohoe, T J; Faggion, C M

    2017-10-01

    The objective of this study was to assess methodological and reporting quality of systematic reviews in hand and wrist pathology. MEDLINE, EMBASE and Cochrane Library were searched from inception to November 2016 for relevant studies. Reporting quality was evaluated using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and methodological quality using a measurement tool to assess systematic reviews, the Assessment of Multiple Systematic Reviews (AMSTAR). Descriptive statistics and linear regression were used to identify features associated with improved methodological quality. A total of 91 studies were included in the analysis. Most reviews inadequately reported PRISMA items regarding study protocol, search strategy and bias and AMSTAR items regarding protocol, publication bias and funding. Systematic reviews published in a plastics journal, or which included more authors, were associated with higher AMSTAR scores. A large proportion of systematic reviews within hand and wrist pathology literature score poorly with validated methodological assessment tools, which may affect the reliability of their conclusions. I.

  9. Anti-tobacco mass media and socially disadvantaged groups: a systematic and methodological review.

    PubMed

    Guillaumier, Ashleigh; Bonevski, Billie; Paul, Chris

    2012-07-01

    Only a limited amount of research has been conducted to explore whether there are socioeconomic status differences in responses to mass media. However, the methodological quality of this evidence has not been assessed, limiting confidence in conclusions that can be drawn regarding study outcomes. A systematic review of the effectiveness of anti-tobacco mass media campaigns with socially disadvantaged groups was conducted, and the methodological quality of included studies was assessed. Medline, The Cochrane Library, PsycInfo, Embase and Web of Science were searched using MeSH and keywords for quantitative studies conducted in Western countries prior to March 2012. A methodological quality assessment and narrative analysis of included studies was undertaken. Seventeen relevant studies (reported in 18 papers) were identified; however, weak study designs and selection bias were common characteristics, limiting strong conclusions about effectiveness. Using predominantly non-cessation related outcome measures reviewed papers indicated mixed results for mass media tobacco control campaign effectiveness among various social groups. Most studies assessed mass media impact on low socioeconomic status groups rather than highly socially disadvantaged groups. Methodological rigour of evaluations in this field must be improved to aid understanding regarding the effectiveness of mass media campaigns in driving cessation among disadvantaged groups. The results of this review indicate a gap in methodologically rigorous research into the effectiveness of mass media campaigns among socially disadvantaged groups, particularly the highly disadvantaged. © 2012 Australasian Professional Society on Alcohol and other Drugs.

  10. Statins, cognition, and dementia—systematic review and methodological commentary

    PubMed Central

    Power, Melinda C.; Weuve, Jennifer; Sharrett, A. Richey; Blacker, Deborah

    2015-01-01

    Firm conclusions about whether mid-life or long-term statin use has an impact on cognitive decline and dementia remain elusive. Here, our objective was to systematically review, synthesize and critique the epidemiological literature that examines the relationship between statin use and cognition, so as to assess the current state of knowledge, identify gaps in our understanding, and make recommendations for future research. We summarize the findings of randomized controlled trials (RCTs) and observational studies, grouped according to study design. We discuss the methods for each, and consider likely sources of bias, such as reverse causation and confounding. Although observational studies that considered statin use at or near the time of dementia diagnosis suggest a protective effect of statins, these findings could be attributable to reverse causation. RCTs and well-conducted observational studies of baseline statin use and subsequent cognition over several years of follow-up do not support a causal preventative effect of late-life statin use on cognitive decline or dementia. Given that much of the human research on statins and cognition in the future will be observational, careful study design and analysis will be essential. PMID:25799928

  11. 'Spin' in published biomedical literature: A methodological systematic review.

    PubMed

    Chiu, Kellia; Grundy, Quinn; Bero, Lisa

    2017-09-01

    In the scientific literature, spin refers to reporting practices that distort the interpretation of results and mislead readers so that results are viewed in a more favourable light. The presence of spin in biomedical research can negatively impact the development of further studies, clinical practice, and health policies. This systematic review aims to explore the nature and prevalence of spin in the biomedical literature. We searched MEDLINE, PreMEDLINE, Embase, Scopus, and hand searched reference lists for all reports that included the measurement of spin in the biomedical literature for at least 1 outcome. Two independent coders extracted data on the characteristics of reports and their included studies and all spin-related outcomes. Results were grouped inductively into themes by spin-related outcome and are presented as a narrative synthesis. We used meta-analyses to analyse the association of spin with industry sponsorship of research. We included 35 reports, which investigated spin in clinical trials, observational studies, diagnostic accuracy studies, systematic reviews, and meta-analyses. The nature of spin varied according to study design. The highest (but also greatest) variability in the prevalence of spin was present in trials. Some of the common practices used to spin results included detracting from statistically nonsignificant results and inappropriately using causal language. Source of funding was hypothesised by a few authors to be a factor associated with spin; however, results were inconclusive, possibly due to the heterogeneity of the included papers. Further research is needed to assess the impact of spin on readers' decision-making. Editors and peer reviewers should be familiar with the prevalence and manifestations of spin in their area of research in order to ensure accurate interpretation and dissemination of research.

  12. CONCEPTUAL DESIGNS FOR A NEW HIGHWAY VEHICLE EMISSIONS ESTIMATION METHODOLOGY

    EPA Science Inventory

    The report discusses six conceptual designs for a new highway vehicle emissions estimation methodology and summarizes the recommendations of each design for improving the emissions and activity factors in the emissions estimation process. he complete design reports are included a...

  13. A critical appraisal of the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing interventions: a systematic review of reviews

    PubMed Central

    Jin, Ying-Hui; Wang, Guo-Hao; Sun, Yi-Rong; Li, Qi; Zhao, Chen; Li, Ge; Si, Jin-Hua; Li, Yan; Lu, Cui; Shang, Hong-Cai

    2016-01-01

    Objective To assess the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing (TCMN) interventions in Chinese journals. These interventions include acupressure, massage, Tai Chi, Qi Gong, electroacupuncture and use of Chinese herbal medicines—for example, in enemas, foot massage and compressing the umbilicus. Design A systematic literature search for systematic reviews and meta-analyses of TCMN interventions was performed. Review characteristics were extracted. The methodological quality and the quality of the evidence were evaluated using the Assessment of Multiple Systematic Reviews (AMSTAR) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) approaches. Result We included 20 systematic reviews and meta-analyses, and a total of 11 TCMN interventions were assessed in the 20 reviews. The compliance with AMSTAR checklist items ranged from 4.5 to 8 and systematic reviews/meta-analyses were, on average, of medium methodological quality. The quality of the evidence we assessed ranged from very low to moderate; no high-quality evidence was found. The top two causes for downrating confidence in effect estimates among the 31 bodies of evidence assessed were the risk of bias and inconsistency. Conclusions There is room for improvement in the methodological quality of systematic reviews/meta-analyses of TCMN interventions published in Chinese journals. Greater efforts should be devoted to ensuring a more comprehensive search strategy, clearer specification of the interventions of interest in the eligibility criteria and identification of meaningful outcomes for clinicians and patients (consumers). The overall quality of evidence among reviews remains suboptimal, which raise concerns about their roles in influencing clinical practice. Thus, the conclusions in reviews we assessed must be treated with caution and their roles in influencing clinical practice should be limited. A critical

  14. Methodology for Preliminary Design of Electrical Microgrids

    SciTech Connect

    Jensen, Richard P.; Stamp, Jason E.; Eddy, John P.; Henry, Jordan M; Munoz-Ramos, Karina; Abdallah, Tarek

    2015-09-30

    Many critical loads rely on simple backup generation to provide electricity in the event of a power outage. An Energy Surety Microgrid TM can protect against outages caused by single generator failures to improve reliability. An ESM will also provide a host of other benefits, including integration of renewable energy, fuel optimization, and maximizing the value of energy storage. The ESM concept includes a categorization for microgrid value proposi- tions, and quantifies how the investment can be justified during either grid-connected or utility outage conditions. In contrast with many approaches, the ESM approach explic- itly sets requirements based on unlikely extreme conditions, including the need to protect against determined cyber adversaries. During the United States (US) Department of Defense (DOD)/Department of Energy (DOE) Smart Power Infrastructure Demonstration for Energy Reliability and Security (SPIDERS) effort, the ESM methodology was successfully used to develop the preliminary designs, which direct supported the contracting, construction, and testing for three military bases. Acknowledgements Sandia National Laboratories and the SPIDERS technical team would like to acknowledge the following for help in the project: * Mike Hightower, who has been the key driving force for Energy Surety Microgrids * Juan Torres and Abbas Akhil, who developed the concept of microgrids for military installations * Merrill Smith, U.S. Department of Energy SPIDERS Program Manager * Ross Roley and Rich Trundy from U.S. Pacific Command * Bill Waugaman and Bill Beary from U.S. Northern Command * Melanie Johnson and Harold Sanborn of the U.S. Army Corps of Engineers Construc- tion Engineering Research Laboratory * Experts from the National Renewable Energy Laboratory, Idaho National Laboratory, Oak Ridge National Laboratory, and Pacific Northwest National Laboratory

  15. A New Methodology to Design Distributed Medical Diagnostic Centers

    DTIC Science & Technology

    2001-10-25

    METHODOLOGY TO DESIGN DISTRIBUTED MEDICAL DIAGNOSTIC CENTERS P. A. Baziana,. E. I. Karavatselou, D. K. Lymberopoulos, D. N. Serpanos Department of...Electrical and Computer Engineering, University of Patras, Patras, Hellas This paper introduces a new methodology for DDC design by controlling the above...TSPs) to design and support cooperative schemes among RUs and DUs in form of DDCs [2]. This paper introduces a global methodology for such a DDC’s

  16. Systematic Review of the Methodological Quality of Studies Aimed at Creating Gestational Weight Gain Charts12

    PubMed Central

    Ohadike, Corah O; Cheikh-Ismail, Leila; Ohuma, Eric O; Giuliani, Francesca; Bishop, Deborah; Kac, Gilberto; Puglia, Fabien; Maia-Schlüssel, Michael; Kennedy, Stephen H; Villar, José; Hirst, Jane E

    2016-01-01

    A range of adverse outcomes is associated with insufficient and excessive maternal weight gain in pregnancy, but there is no consensus regarding what constitutes optimal gestational weight gain (GWG). Differences in the methodological quality of GWG studies may explain the varying chart recommendations. The goal of this systematic review was to evaluate the methodological quality of studies that aimed to create GWG charts by scoring them against a set of predefined, independently agreed-upon criteria. These criteria were divided into 3 domains: study design (12 criteria), statistical methods (7 criteria), and reporting methods (4 criteria). The criteria were broken down further into items, and studies were assigned a quality score (QS) based on these criteria. For each item, studies were scored as either high (score = 0) or low (score = 1) risk of bias; a high QS correlated with a low risk of bias. The maximum possible QS was 34. The systematic search identified 12 eligible studies involving 2,268,556 women from 9 countries; their QSs ranged from 9 (26%) to 29 (85%) (median, 18; 53%). The most common sources for bias were found in study designs (i.e., not prospective); assessments of prepregnancy weight and gestational age; descriptions of weighing protocols; sample size calculations; and the multiple measurements taken at each visit. There is wide variation in the methodological quality of GWG studies constructing charts. High-quality studies are needed to guide future clinical recommendations. We recommend the following main requirements for future studies: prospective design, reliable evaluation of prepregnancy weight and gestational age, detailed description of measurement procedures and protocols, description of sample-size calculation, and the creation of smooth centile charts or z scores. PMID:26980814

  17. Systematic Review of the Methodological Quality of Studies Aimed at Creating Gestational Weight Gain Charts.

    PubMed

    Ohadike, Corah O; Cheikh-Ismail, Leila; Ohuma, Eric O; Giuliani, Francesca; Bishop, Deborah; Kac, Gilberto; Puglia, Fabien; Maia-Schlüssel, Michael; Kennedy, Stephen H; Villar, José; Hirst, Jane E

    2016-03-01

    A range of adverse outcomes is associated with insufficient and excessive maternal weight gain in pregnancy, but there is no consensus regarding what constitutes optimal gestational weight gain (GWG). Differences in the methodological quality of GWG studies may explain the varying chart recommendations. The goal of this systematic review was to evaluate the methodological quality of studies that aimed to create GWG charts by scoring them against a set of predefined, independently agreed-upon criteria. These criteria were divided into 3 domains: study design (12 criteria), statistical methods (7 criteria), and reporting methods (4 criteria). The criteria were broken down further into items, and studies were assigned a quality score (QS) based on these criteria. For each item, studies were scored as either high (score = 0) or low (score = 1) risk of bias; a high QS correlated with a low risk of bias. The maximum possible QS was 34. The systematic search identified 12 eligible studies involving 2,268,556 women from 9 countries; their QSs ranged from 9 (26%) to 29 (85%) (median, 18; 53%). The most common sources for bias were found in study designs (i.e., not prospective); assessments of prepregnancy weight and gestational age; descriptions of weighing protocols; sample size calculations; and the multiple measurements taken at each visit. There is wide variation in the methodological quality of GWG studies constructing charts. High-quality studies are needed to guide future clinical recommendations. We recommend the following main requirements for future studies: prospective design, reliable evaluation of prepregnancy weight and gestational age, detailed description of measurement procedures and protocols, description of sample-size calculation, and the creation of smooth centile charts or z scores. © 2016 American Society for Nutrition.

  18. Case-Only Designs in Pharmacoepidemiology: A Systematic Review

    PubMed Central

    Ravaud, Philippe; Esposito-Farèse, Marina; Tubach, Florence

    2012-01-01

    Background Case-only designs have been used since late 1980’s. In these, as opposed to case-control or cohort studies for instance, only cases are required and are self-controlled, eliminating selection biases and confounding related to control subjects, and time-invariant characteristics. The objectives of this systematic review were to analyze how the two main case-only designs – case-crossover (CC) and self-controlled case series (SCCS) – have been applied and reported in pharmacoepidemiology literature, in terms of applicability assumptions and specificities of these designs. Methodology/Principal Findings We systematically selected all reports in this field involving case-only designs from MEDLINE and EMBASE up to September 15, 2010. Data were extracted using a standardized form. The analysis included 93 reports 50 (54%) of CC and 45 (48%) SCCS, 2 reports combined both designs. In 12 (24%) CC and 18 (40%) SCCS articles, all applicable validity assumptions of the designs were fulfilled, respectively. Fifty (54%) articles (15 CC (30%) and 35 (78%) SCCS) adequately addressed the specificities of the case-only analyses in the way they reported results. Conclusions/Significance Our systematic review underlines that implementation of CC and SCCS designs needs to be more rigorous with regard to validity assumptions, as well as improvement in results reporting. PMID:23166668

  19. Enhancing the Front-End Phase of Design Methodology

    ERIC Educational Resources Information Center

    Elias, Erasto

    2006-01-01

    Design methodology (DM) is defined by the procedural path, expressed in design models, and techniques or methods used to untangle the various activities within a design model. Design education in universities is mainly based on descriptive design models. Much knowledge and organization have been built into DM to facilitate design teaching.…

  20. Application of systematic review methodology to the field of nutrition

    USDA-ARS?s Scientific Manuscript database

    Systematic reviews represent a rigorous and transparent approach of synthesizing scientific evidence that minimizes bias. They evolved within the medical community to support development of clinical and public health practice guidelines, set research agendas and formulate scientific consensus state...

  1. Lean management in health care: definition, concepts, methodology and effects reported (systematic review protocol)

    PubMed Central

    2014-01-01

    Background Lean is a set of operating philosophies and methods that help create a maximum value for patients by reducing waste and waits. It emphasizes the consideration of the customer’s needs, employee involvement and continuous improvement. Research on the application and implementation of lean principles in health care has been limited. Methods This is a protocol for a systematic review, following the Cochrane Effective Practice and Organisation of Care (EPOC) methodology. The review aims to document, catalogue and synthesize the existing literature on the effects of lean implementation in health care settings especially the potential effects on professional practice and health care outcomes. We have developed a Medline keyword search strategy, and this focused strategy will be translated into other databases. All search strategies will be provided in the review. The method proposed by the Cochrane EPOC group regarding randomized study designs, non-randomised controlled trials controlled before and after studies and interrupted time series will be followed. In addition, we will also include cohort, case–control studies, and relevant non-comparative publications such as case reports. We will categorize and analyse the review findings according to the study design employed, the study quality (low- versus high-quality studies) and the reported types of implementation in the primary studies. We will present the results of studies in a tabular form. Discussion Overall, the systematic review aims to identify, assess and synthesize the evidence to underpin the implementation of lean activities in health care settings as defined in this protocol. As a result, the review will provide an evidence base for the effectiveness of lean and implementation methodologies reported in health care. Systematic review registration PROSPERO CRD42014008853 PMID:25238974

  2. Toward systematic design of multi-standard converters

    NASA Astrophysics Data System (ADS)

    Rivas, V. J.; Castro-López, R.; Morgado, A.; Guerra, O.; Roca, E.; del Río, R.; de la Rosa, J. M.; Fernández, F. V.

    2007-05-01

    In the last few years, we are witnessing the convergence of more and more communication capabilities into a single terminal. A basic component of these communication transceivers is the multi-standard Analog-to-Digital-Converter (ADC). Many systematic, partially automated approaches for the design of ADCs dealing with a single communication standard have been reported. However, most multi-standard converters reported in the literature follow an ad-hoc approach, which do not guarantee either an efficient occupation of silicon area or its power efficiency in the different standards. This paper aims at the core of this problem by formulating a systematic design approach based on the following key elements: (1) Definition of a set of metrics for reconfigurability: impact in area and power consumption, design complexity and performances; (2) Definition of the reconfiguration capabilities of the component blocks at different hierarchical levels, with assessment of the associated metrics; (3) Exploration of candidate architectures by using a combination of simulated annealing and evolutionary algorithms; (4) Improved top-down synthesis with bottom-up generated low-level design information. The systematic design methodology is illustrated via the design of a multi-standard ΣΔ modulator meeting the specifications of three wireless communication standards.

  3. A Design Methodology for Medical Processes.

    PubMed

    Ferrante, Simona; Bonacina, Stefano; Pozzi, Giuseppe; Pinciroli, Francesco; Marceglia, Sara

    2016-01-01

    Healthcare processes, especially those belonging to the clinical domain, are acknowledged as complex and characterized by the dynamic nature of the diagnosis, the variability of the decisions made by experts driven by their experiences, the local constraints, the patient's needs, the uncertainty of the patient's response, and the indeterminacy of patient's compliance to treatment. Also, the multiple actors involved in patient's care need clear and transparent communication to ensure care coordination. In this paper, we propose a methodology to model healthcare processes in order to break out complexity and provide transparency. The model is grounded on a set of requirements that make the healthcare domain unique with respect to other knowledge domains. The modeling methodology is based on three main phases: the study of the environmental context, the conceptual modeling, and the logical modeling. The proposed methodology was validated by applying it to the case study of the rehabilitation process of stroke patients in the specific setting of a specialized rehabilitation center. The resulting model was used to define the specifications of a software artifact for the digital administration and collection of assessment tests that was also implemented. Despite being only an example, our case study showed the ability of process modeling to answer the actual needs in healthcare practices. Independently from the medical domain in which the modeling effort is done, the proposed methodology is useful to create high-quality models, and to detect and take into account relevant and tricky situations that can occur during process execution.

  4. Design Research: Theoretical and Methodological Issues

    ERIC Educational Resources Information Center

    Collins, Allan; Joseph, Diana; Bielaczyc, Katerine

    2004-01-01

    The term "design experiments" was introduced in 1992, in articles by Ann Brown (1992) and Allan Collins (1992). Design experiments were developed as a way to carry out formative research to test and refine educational designs based on principles derived from prior research. More recently the term design research has been applied to this kind of…

  5. Technical report on LWR design decision methodology. Phase I

    SciTech Connect

    1980-03-01

    Energy Incorporated (EI) was selected by Sandia Laboratories to develop and test on LWR design decision methodology. Contract Number 42-4229 provided funding for Phase I of this work. This technical report on LWR design decision methodology documents the activities performed under that contract. Phase I was a short-term effort to thoroughly review the curret LWR design decision process to assure complete understanding of current practices and to establish a well defined interface for development of initial quantitative design guidelines.

  6. Systematic Reviews of Animal Models: Methodology versus Epistemology

    PubMed Central

    Greek, Ray; Menache, Andre

    2013-01-01

    Systematic reviews are currently favored methods of evaluating research in order to reach conclusions regarding medical practice. The need for such reviews is necessitated by the fact that no research is perfect and experts are prone to bias. By combining many studies that fulfill specific criteria, one hopes that the strengths can be multiplied and thus reliable conclusions attained. Potential flaws in this process include the assumptions that underlie the research under examination. If the assumptions, or axioms, upon which the research studies are based, are untenable either scientifically or logically, then the results must be highly suspect regardless of the otherwise high quality of the studies or the systematic reviews. We outline recent criticisms of animal-based research, namely that animal models are failing to predict human responses. It is this failure that is purportedly being corrected via systematic reviews. We then examine the assumption that animal models can predict human outcomes to perturbations such as disease or drugs, even under the best of circumstances. We examine the use of animal models in light of empirical evidence comparing human outcomes to those from animal models, complexity theory, and evolutionary biology. We conclude that even if legitimate criticisms of animal models were addressed, through standardization of protocols and systematic reviews, the animal model would still fail as a predictive modality for human response to drugs and disease. Therefore, systematic reviews and meta-analyses of animal-based research are poor tools for attempting to reach conclusions regarding human interventions. PMID:23372426

  7. Systematic reviews of animal models: methodology versus epistemology.

    PubMed

    Greek, Ray; Menache, Andre

    2013-01-01

    Systematic reviews are currently favored methods of evaluating research in order to reach conclusions regarding medical practice. The need for such reviews is necessitated by the fact that no research is perfect and experts are prone to bias. By combining many studies that fulfill specific criteria, one hopes that the strengths can be multiplied and thus reliable conclusions attained. Potential flaws in this process include the assumptions that underlie the research under examination. If the assumptions, or axioms, upon which the research studies are based, are untenable either scientifically or logically, then the results must be highly suspect regardless of the otherwise high quality of the studies or the systematic reviews. We outline recent criticisms of animal-based research, namely that animal models are failing to predict human responses. It is this failure that is purportedly being corrected via systematic reviews. We then examine the assumption that animal models can predict human outcomes to perturbations such as disease or drugs, even under the best of circumstances. We examine the use of animal models in light of empirical evidence comparing human outcomes to those from animal models, complexity theory, and evolutionary biology. We conclude that even if legitimate criticisms of animal models were addressed, through standardization of protocols and systematic reviews, the animal model would still fail as a predictive modality for human response to drugs and disease. Therefore, systematic reviews and meta-analyses of animal-based research are poor tools for attempting to reach conclusions regarding human interventions.

  8. Methodology Series Module 6: Systematic Reviews and Meta-analysis

    PubMed Central

    Setia, Maninder Singh

    2016-01-01

    Systematic reviews and meta-analysis have become an important of biomedical literature, and they provide the “highest level of evidence” for various clinical questions. There are a lot of studies – sometimes with contradictory conclusions – on a particular topic in literature. Hence, as a clinician, which results will you believe? What will you tell your patient? Which drug is better? A systematic review or a meta-analysis may help us answer these questions. In addition, it may also help us understand the quality of the articles in literature or the type of studies that have been conducted and published (example, randomized trials or observational studies). The first step it to identify a research question for systematic review or meta-analysis. The next step is to identify the articles that will be included in the study. This will be done by searching various databases; it is important that the researcher should search for articles in more than one database. It will also be useful to form a group of researchers and statisticians that have expertise in conducting systematic reviews and meta-analysis before initiating them. We strongly encourage the readers to register their proposed review/meta-analysis with PROSPERO. Finally, these studies should be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis checklist. PMID:27904176

  9. Assessing the impact of healthcare research: A systematic review of methodological frameworks

    PubMed Central

    Keeley, Thomas J.; Calvert, Melanie J.

    2017-01-01

    Background Increasingly, researchers need to demonstrate the impact of their research to their sponsors, funders, and fellow academics. However, the most appropriate way of measuring the impact of healthcare research is subject to debate. We aimed to identify the existing methodological frameworks used to measure healthcare research impact and to summarise the common themes and metrics in an impact matrix. Methods and findings Two independent investigators systematically searched the Medical Literature Analysis and Retrieval System Online (MEDLINE), the Excerpta Medica Database (EMBASE), the Cumulative Index to Nursing and Allied Health Literature (CINAHL+), the Health Management Information Consortium, and the Journal of Research Evaluation from inception until May 2017 for publications that presented a methodological framework for research impact. We then summarised the common concepts and themes across methodological frameworks and identified the metrics used to evaluate differing forms of impact. Twenty-four unique methodological frameworks were identified, addressing 5 broad categories of impact: (1) ‘primary research-related impact’, (2) ‘influence on policy making’, (3) ‘health and health systems impact’, (4) ‘health-related and societal impact’, and (5) ‘broader economic impact’. These categories were subdivided into 16 common impact subgroups. Authors of the included publications proposed 80 different metrics aimed at measuring impact in these areas. The main limitation of the study was the potential exclusion of relevant articles, as a consequence of the poor indexing of the databases searched. Conclusions The measurement of research impact is an essential exercise to help direct the allocation of limited research resources, to maximise research benefit, and to help minimise research waste. This review provides a collective summary of existing methodological frameworks for research impact, which funders may use to inform the

  10. The methodological quality of systematic reviews published in high-impact nursing journals: a review of the literature.

    PubMed

    Pölkki, Tarja; Kanste, Outi; Kääriäinen, Maria; Elo, Satu; Kyngäs, Helvi

    2014-02-01

    To analyse systematic review articles published in the top 10 nursing journals to determine the quality of the methods employed within them. Systematic review is defined as a scientific research method that synthesises high-quality scientific knowledge on a given topic. The number of such reviews in nursing science has increased dramatically during recent years, but their methodological quality has not previously been assessed. A review of the literature using a narrative approach. Ranked impact factor scores for nursing journals were obtained from the Journal Citation Report database of the Institute of Scientific Information (ISI Web of Knowledge). All issues from the years 2009 and 2010 of the top 10 ranked journals were included. CINAHL and MEDLINE databases were searched to locate studies using the search terms 'systematic review' and 'systematic literature review'. A total of 39 eligible studies were identified. Their methodological quality was evaluated through the specific criteria of quality assessment, description of synthesis and strengths and weaknesses reported in the included studies. Most of the eligible systematic reviews included several different designs or types of quantitative study. The majority included a quality assessment, and a total of 17 different criteria were identified. The method of synthesis was mentioned in about half of the reviews, the most common being narrative synthesis. The weaknesses of reviews were discussed, while strengths were rarely highlighted. The methodological quality of the systematic reviews examined varied considerably, although they were all published in nursing journals with a high-impact factor. Despite the fact that systematic reviews are considered the most robust source of research evidence, they vary in methodological quality. This point is important to consider in clinical practice when applying the results to patient care. © 2013 Blackwell Publishing Ltd.

  11. A Design Methodology for Medical Processes

    PubMed Central

    Bonacina, Stefano; Pozzi, Giuseppe; Pinciroli, Francesco; Marceglia, Sara

    2016-01-01

    Summary Background Healthcare processes, especially those belonging to the clinical domain, are acknowledged as complex and characterized by the dynamic nature of the diagnosis, the variability of the decisions made by experts driven by their experiences, the local constraints, the patient’s needs, the uncertainty of the patient’s response, and the indeterminacy of patient’s compliance to treatment. Also, the multiple actors involved in patient’s care need clear and transparent communication to ensure care coordination. Objectives In this paper, we propose a methodology to model healthcare processes in order to break out complexity and provide transparency. Methods The model is grounded on a set of requirements that make the healthcare domain unique with respect to other knowledge domains. The modeling methodology is based on three main phases: the study of the environmental context, the conceptual modeling, and the logical modeling. Results The proposed methodology was validated by applying it to the case study of the rehabilitation process of stroke patients in the specific setting of a specialized rehabilitation center. The resulting model was used to define the specifications of a software artifact for the digital administration and collection of assessment tests that was also implemented. Conclusions Despite being only an example, our case study showed the ability of process modeling to answer the actual needs in healthcare practices. Independently from the medical domain in which the modeling effort is done, the proposed methodology is useful to create high-quality models, and to detect and take into account relevant and tricky situations that can occur during process execution. PMID:27081415

  12. Systematic design assessment techniques for solar buildings

    NASA Astrophysics Data System (ADS)

    Page, J. K.; Rodgers, G. G.; Souster, C. G.

    1980-02-01

    The paper describes the various approaches developed for the detailed modelling of the relevant climatic input variables for systematic design assessments for solar housing techniques. A report is made of the techniques developed to generate systematic short wave radiation data for vertical and inclined surfaces for different types of weather. The analysis is based on different types of days, such as sunny, average and overcast. Work on the accurate estimation of the magnitude of the associated weather variables affecting heat transfer in the external environment is also reported, covering air temperature, wind speed and long wave radiation exchanges.

  13. Environmental and Sustainability Education Policy Research: A Systematic Review of Methodological and Thematic Trends

    ERIC Educational Resources Information Center

    Aikens, Kathleen; McKenzie, Marcia; Vaughter, Philip

    2016-01-01

    This paper reports on a systematic literature review of policy research in the area of environmental and sustainability education. We analyzed 215 research articles, spanning four decades and representing 71 countries, and which engaged a range of methodologies. Our analysis combines quantification of geographic and methodological trends with…

  14. Environmental and Sustainability Education Policy Research: A Systematic Review of Methodological and Thematic Trends

    ERIC Educational Resources Information Center

    Aikens, Kathleen; McKenzie, Marcia; Vaughter, Philip

    2016-01-01

    This paper reports on a systematic literature review of policy research in the area of environmental and sustainability education. We analyzed 215 research articles, spanning four decades and representing 71 countries, and which engaged a range of methodologies. Our analysis combines quantification of geographic and methodological trends with…

  15. [Reporting specification of systematic reviews on Chinese medicine and methodological evaluation].

    PubMed

    Han, Mei; Wang, Yu-Yi; Mu, Yu-Jie

    2012-07-01

    Currently, the number of systematic reviews on Chinese medicine (CM) increases gradually. However, the quality of the reviews varied, which resulted in great limitations in guiding clinical practice. This article refers to the Cochrane Handbook and PRISMA Statement to introduce the reporting specification of the systematic review, including asking a research question, review methods, presentation of the results, discussion and conclusion. We analyzed the methodology issues in the published systematic reviews on CM in order to improve the quality of future reviews.

  16. A New Methodology for Systematic Exploitation of Technology Databases.

    ERIC Educational Resources Information Center

    Bedecarrax, Chantal; Huot, Charles

    1994-01-01

    Presents the theoretical aspects of a data analysis methodology that can help transform sequential raw data from a database into useful information, using the statistical analysis of patents as an example. Topics discussed include relational analysis and a technology watch approach. (Contains 17 references.) (LRW)

  17. Autism genetics: Methodological issues and experimental design.

    PubMed

    Sacco, Roberto; Lintas, Carla; Persico, Antonio M

    2015-10-01

    Autism is a complex neuropsychiatric disorder of developmental origin, where multiple genetic and environmental factors likely interact resulting in a clinical continuum between "affected" and "unaffected" individuals in the general population. During the last two decades, relevant progress has been made in identifying chromosomal regions and genes in linkage or association with autism, but no single gene has emerged as a major cause of disease in a large number of patients. The purpose of this paper is to discuss specific methodological issues and experimental strategies in autism genetic research, based on fourteen years of experience in patient recruitment and association studies of autism spectrum disorder in Italy.

  18. A Methodology for Total Hospital Design

    PubMed Central

    Delon, Gerald L.

    1970-01-01

    A procedure is described that integrates three techniques into a unified approach: a computerized method for estimating departmental areas and construction costs, a computerized layout routine that produces a space-relationship diagram based on qualitative factors, and a second layout program that establishes a final layout by a series of iterations. The methodology described utilizes as input the results of earlier phases of the research, with the output of each step in turn becoming the input for the succeeding step. The method is illustrated by application to a hypothetical pediatric hospital of 100 beds. PMID:5494263

  19. Forced vibration and flutter design methodology

    SciTech Connect

    Snyder, L.E.; Burns, D.W.

    1988-06-01

    The aeroelastic principles and considerations of designing blades, disks, and vanes to avoid high cycle fatigue failure is covered. Two types of vibration that can cause high cycle fatigue, flutter, and forced vibration, will first be defined and the basic governing equations discussed. Next, under forced vibration design the areas of source definition, types of components, vibratory mode shape definitions, and basic steps in design for adequate high cycle fatigue life will be presented. For clarification a forced vibration design example will be shown using a high performance turbine blade/disk component. Finally, types of flutter, dominant flutter parameters, and flutter procedures and design parameters will be discussed. The overall emphasis is on application to initial design of blades, disks, and vanes of aeroelastic criteria to prevent high cycle fatigue failures.

  20. The Study of the Relationship between Probabilistic Design and Axiomatic Design Methodology. Volume 1

    NASA Technical Reports Server (NTRS)

    Onwubiko, Chinyere; Onyebueke, Landon

    1996-01-01

    This program report is the final report covering all the work done on this project. The goal of this project is technology transfer of methodologies to improve design process. The specific objectives are: 1. To learn and understand the Probabilistic design analysis using NESSUS. 2. To assign Design Projects to either undergraduate or graduate students on the application of NESSUS. 3. To integrate the application of NESSUS into some selected senior level courses in Civil and Mechanical Engineering curricula. 4. To develop courseware in Probabilistic Design methodology to be included in a graduate level Design Methodology course. 5. To study the relationship between the Probabilistic design methodology and Axiomatic design methodology.

  1. Methodological guidance documents for evaluation of ethical considerations in health technology assessment: a systematic review.

    PubMed

    Assasi, Nazila; Schwartz, Lisa; Tarride, Jean-Eric; Campbell, Kaitryn; Goeree, Ron

    2014-04-01

    Despite the advances made in the development of ethical frameworks for health technology assessment (HTA), there is no clear agreement on the scope and details of a practical approach to address ethical aspects in HTA. This systematic review aimed to identify existing guidance documents for incorporation of ethics in HTA to provide an overview of their methodological features. The review identified 43 conceptual frameworks or practical guidelines, varying in their philosophical approach, structure, and comprehensiveness. They were designed for different purposes throughout the HTA process, ranging from helping HTA-producers in identification, appraisal and analysis of ethical data to supporting decision-makers in making value-sensitive decisions. They frequently promoted using analytical methods that combined normative reflection with participatory approaches. The choice of a method for collection and analysis of ethical data seems to depend on the context in which technology is being assessed, the purpose of analysis, and availability of required resources.

  2. Lean management in health care: definition, concepts, methodology and effects reported (systematic review protocol).

    PubMed

    Lawal, Adegboyega K; Rotter, Thomas; Kinsman, Leigh; Sari, Nazmi; Harrison, Liz; Jeffery, Cathy; Kutz, Mareike; Khan, Mohammad F; Flynn, Rachel

    2014-09-19

    Lean is a set of operating philosophies and methods that help create a maximum value for patients by reducing waste and waits. It emphasizes the consideration of the customer's needs, employee involvement and continuous improvement. Research on the application and implementation of lean principles in health care has been limited. This is a protocol for a systematic review, following the Cochrane Effective Practice and Organisation of Care (EPOC) methodology. The review aims to document, catalogue and synthesize the existing literature on the effects of lean implementation in health care settings especially the potential effects on professional practice and health care outcomes. We have developed a Medline keyword search strategy, and this focused strategy will be translated into other databases. All search strategies will be provided in the review. The method proposed by the Cochrane EPOC group regarding randomized study designs, non-randomised controlled trials controlled before and after studies and interrupted time series will be followed. In addition, we will also include cohort, case-control studies, and relevant non-comparative publications such as case reports. We will categorize and analyse the review findings according to the study design employed, the study quality (low- versus high-quality studies) and the reported types of implementation in the primary studies. We will present the results of studies in a tabular form. Overall, the systematic review aims to identify, assess and synthesize the evidence to underpin the implementation of lean activities in health care settings as defined in this protocol. As a result, the review will provide an evidence base for the effectiveness of lean and implementation methodologies reported in health care. PROSPERO CRD42014008853.

  3. The methodological and reporting quality of systematic reviews from China and the USA are similar.

    PubMed

    Tian, Jinhui; Zhang, Jun; Ge, Long; Yang, Kehu; Song, Fujian

    2017-05-01

    To compare the methodological and reporting quality of systematic reviews by authors from China and those from the United States (USA). From systematic reviews of randomized trials published in 2014 in English, we randomly selected 100 from China and 100 from the USA. The methodological quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool, and reporting quality assessed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) tool. Compared with systematic reviews from the USA, those from China were more likely to be a meta-analysis, published in low-impact journals, and a non-Cochrane review. The mean summary Assessing the Methodological Quality of Systematic Reviews score was 6.7 (95% confidence interval: 6.5, 7.0) for reviews from China and 6.6 (6.1, 7.1) for reviews from the USA, and the mean summary Preferred Reporting Items for Systematic Reviews and Meta-analyses score was 21.2 (20.7, 21.6) for reviews from China and 20.6 (19.9, 21.3) for reviews from the USA. The differences in summary quality scores between China and the USA were statistically nonsignificant after adjusting for multiple review factors. The overall methodological and reporting quality of systematic reviews by authors from China are similar to those from the USA, although the quality of systematic reviews from both countries could be further improved. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Design: The Only Methodology of Technology?

    ERIC Educational Resources Information Center

    Williams, P. John

    2000-01-01

    Technology education involves procedural knowledge related to technology activity and conceptual knowledge related to content. Technology processes include design, problem solving, systems approach, invention, and manufacturing. Using a range of processes in teaching can accommodate various learning styles. (SK)

  5. Systematic Experimental Designs For Mixed-species Plantings

    Treesearch

    Jeffery C. Goelz

    2001-01-01

    Systematic experimental designs provide splendid demonstration areas for scientists and land managers to observe the effects of a gradient of species composition. Systematic designs are based on large plots where species composition varies gradually. Systematic designs save considerable space and require many fewer seedlings than conventional mixture designs. One basic...

  6. A design optimization methodology for Li+ batteries

    NASA Astrophysics Data System (ADS)

    Golmon, Stephanie; Maute, Kurt; Dunn, Martin L.

    2014-05-01

    Design optimization for functionally graded battery electrodes is shown to improve the usable energy capacity of Li batteries predicted by computational simulations and numerically optimizing the electrode porosities and particle radii. A multi-scale battery model which accounts for nonlinear transient transport processes, electrochemical reactions, and mechanical deformations is used to predict the usable energy storage capacity of the battery over a range of discharge rates. A multi-objective formulation of the design problem is introduced to maximize the usable capacity over a range of discharge rates while limiting the mechanical stresses. The optimization problem is solved via a gradient based optimization. A LiMn2O4 cathode is simulated with a PEO-LiCF3SO3 electrolyte and both a Li Foil (half cell) and LiC6 anode. Studies were performed on both half and full cell configurations resulting in distinctly different optimal electrode designs. The numerical results show that the highest rate discharge drives the simulations and the optimal designs are dominated by Li+ transport rates. The results also suggest that spatially varying electrode porosities and active particle sizes provides an efficient approach to improve the power-to-energy density of Li+ batteries. For the half cell configuration, the optimal design improves the discharge capacity by 29% while for the full cell the discharge capacity was improved 61% relative to an initial design with a uniform electrode structure. Most of the improvement in capacity was due to the spatially varying porosity, with up to 5% of the gains attributed to the particle radii design variables.

  7. Design Study Methodology: Reflections from the Trenches and the Stacks.

    PubMed

    Sedlmair, M; Meyer, M; Munzner, T

    2012-12-01

    Design studies are an increasingly popular form of problem-driven visualization research, yet there is little guidance available about how to do them effectively. In this paper we reflect on our combined experience of conducting twenty-one design studies, as well as reading and reviewing many more, and on an extensive literature review of other field work methods and methodologies. Based on this foundation we provide definitions, propose a methodological framework, and provide practical guidance for conducting design studies. We define a design study as a project in which visualization researchers analyze a specific real-world problem faced by domain experts, design a visualization system that supports solving this problem, validate the design, and reflect about lessons learned in order to refine visualization design guidelines. We characterize two axes - a task clarity axis from fuzzy to crisp and an information location axis from the domain expert's head to the computer - and use these axes to reason about design study contributions, their suitability, and uniqueness from other approaches. The proposed methodological framework consists of 9 stages: learn, winnow, cast, discover, design, implement, deploy, reflect, and write. For each stage we provide practical guidance and outline potential pitfalls. We also conducted an extensive literature survey of related methodological approaches that involve a significant amount of qualitative field work, and compare design study methodology to that of ethnography, grounded theory, and action research.

  8. Implicit Shape Parameterization for Kansei Design Methodology

    NASA Astrophysics Data System (ADS)

    Nordgren, Andreas Kjell; Aoyama, Hideki

    Implicit shape parameterization for Kansei design is a procedure that use 3D-models, or concepts, to span a shape space for surfaces in the automotive field. A low-dimensional, yet accurate shape descriptor was found by Principal Component Analysis of an ensemble of point-clouds, which were extracted from mesh-based surfaces modeled in a CAD-program. A theoretical background of the procedure is given along with step-by-step instructions for the required data-processing. The results show that complex surfaces can be described very efficiently, and encode design features by an implicit approach that does not rely on error-prone explicit parameterizations. This provides a very intuitive way to explore shapes for a designer, because various design features can simply be introduced by adding new concepts to the ensemble. Complex shapes have been difficult to analyze with Kansei methods due to the large number of parameters involved, but implicit parameterization of design features provides a low-dimensional shape descriptor for efficient data collection, model-building and analysis of emotional content in 3D-surfaces.

  9. The methodology of database design in organization management systems

    NASA Astrophysics Data System (ADS)

    Chudinov, I. L.; Osipova, V. V.; Bobrova, Y. V.

    2017-01-01

    The paper describes the unified methodology of database design for management information systems. Designing the conceptual information model for the domain area is the most important and labor-intensive stage in database design. Basing on the proposed integrated approach to design, the conceptual information model, the main principles of developing the relation databases are provided and user’s information needs are considered. According to the methodology, the process of designing the conceptual information model includes three basic stages, which are defined in detail. Finally, the article describes the process of performing the results of analyzing user’s information needs and the rationale for use of classifiers.

  10. Design Methodology for Multiple Microcomputer Architectures.

    DTIC Science & Technology

    1982-07-01

    multimicro design knowledge is true both in industry and in university environments. In the industrial environment, it reduces productivity and increases...Real-Time Processor Problems," Proc. of ELECTRO-81 Tercer Seminario de Ingenieria Electronica, Nov. 9-13, 1981. 14 1981 "D Flip/Flop Substracts

  11. Army Design Methodology: Commander’s Resource

    DTIC Science & Technology

    2012-02-01

    This resource is intended to help bridge the gap from Design theory and classroom instruction to application of ADM in the field. It offers...to capture the knowledge, and that was immensely difficult. We drew a spaghetti diagram. It was awful. If you pulled it out today, we could

  12. A Design Methodology For Industrial Vision Systems

    NASA Astrophysics Data System (ADS)

    Batchelor, B. G.; Waltz, F. M.; Snyder, M. A.

    1988-11-01

    The cost of design, rather than that of target system hardware, represents the principal factor inhibiting the adoption of machine vision systems by manufacturing industry. To reduce design costs to a minimum, a number of software and hardware aids have been developed or are currently being built by the authors. These design aids are as follows: a. An expert system for giving advice about which image acquisition techniques (i.e. lighting/viewing techniques) might be appropriate in a given situation. b. A program to assist in the selection and setup of camera lenses. c. A rich repertoire of image processing procedures, integrated with the Al language Prolog. This combination (called ProVision) provides a facility for experimenting with intelligent image processing techniques and is intended to allow rapid prototyping of algorithms and/or heuristics. d. Fast image processing hardware, capable of implementing commands in the ProVision language. The speed of operation of this equipment is sufficiently high for it to be used, without modification, in many industrial applications. Where this is not possible, even higher execution speed may be achieved by adding extra modules to the processing hardware. In this way, it is possible to trade speed against the cost of the target system hardware. New and faster implementations of a given algorithm/heuristic can usually be achieved with the expenditure of only a small effort. Throughout this article, the emphasis is on designing an industrial vision system in a smooth and effortless manner. In order to illustrate our main thesis that the design of industrial vision systems can be made very much easier through the use of suitable utilities, the article concludes with a discussion of a case study: the dissection of tiny plants using a visually controlled robot.

  13. Philosophical and Methodological Beliefs of Instructional Design Faculty and Professionals

    ERIC Educational Resources Information Center

    Sheehan, Michael D.; Johnson, R. Burke

    2012-01-01

    The purpose of this research was to probe the philosophical beliefs of instructional designers using sound philosophical constructs and quantitative data collection and analysis. We investigated the philosophical and methodological beliefs of instructional designers, including 152 instructional design faculty members and 118 non-faculty…

  14. Philosophical and Methodological Beliefs of Instructional Design Faculty and Professionals

    ERIC Educational Resources Information Center

    Sheehan, Michael D.; Johnson, R. Burke

    2012-01-01

    The purpose of this research was to probe the philosophical beliefs of instructional designers using sound philosophical constructs and quantitative data collection and analysis. We investigated the philosophical and methodological beliefs of instructional designers, including 152 instructional design faculty members and 118 non-faculty…

  15. Development of Distributed Computing Systems Software Design Methodologies.

    DTIC Science & Technology

    1982-11-05

    R12i 941 DEVELOPMENT OF DISTRIBUTED COMPUTING SYSTEMS SOFTWARE ± DESIGN METHODOLOGIES(U) NORTHWESTERN UNIV EVANSTON IL DEPT OF ELECTRICAL...GUIRWAU OF STANDARDS -16 5 A Ax u FINAL REPORT Development of Distributed Computing System Software Design Methodologies C)0 Stephen S. Yau September 22...of Distributed Computing Systems Software pt.22,, 80 -OJu1, 2 * Dsig Mehodloges PERFORMING ORG REPORT NUMBERDesign th ol ies" 7. AUTHOR() .. CONTRACT

  16. Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist.

    PubMed

    Terwee, Caroline B; Mokkink, Lidwine B; Knol, Dirk L; Ostelo, Raymond W J G; Bouter, Lex M; de Vet, Henrica C W

    2012-05-01

    The COSMIN checklist is a standardized tool for assessing the methodological quality of studies on measurement properties. It contains 9 boxes, each dealing with one measurement property, with 5-18 items per box about design aspects and statistical methods. Our aim was to develop a scoring system for the COSMIN checklist to calculate quality scores per measurement property when using the checklist in systematic reviews of measurement properties. The scoring system was developed based on discussions among experts and testing of the scoring system on 46 articles from a systematic review. Four response options were defined for each COSMIN item (excellent, good, fair, and poor). A quality score per measurement property is obtained by taking the lowest rating of any item in a box ("worst score counts"). Specific criteria for excellent, good, fair, and poor quality for each COSMIN item are described. In defining the criteria, the "worst score counts" algorithm was taken into consideration. This means that only fatal flaws were defined as poor quality. The scores of the 46 articles show how the scoring system can be used to provide an overview of the methodological quality of studies included in a systematic review of measurement properties. Based on experience in testing this scoring system on 46 articles, the COSMIN checklist with the proposed scoring system seems to be a useful tool for assessing the methodological quality of studies included in systematic reviews of measurement properties.

  17. Systematic design for trait introgression projects.

    PubMed

    Cameron, John N; Han, Ye; Wang, Lizhi; Beavis, William D

    2017-06-24

    Using an Operations Research approach, we demonstrate design of optimal trait introgression projects with respect to competing objectives. We demonstrate an innovative approach for designing Trait Introgression (TI) projects based on optimization principles from Operations Research. If the designs of TI projects are based on clear and measurable objectives, they can be translated into mathematical models with decision variables and constraints that can be translated into Pareto optimality plots associated with any arbitrary selection strategy. The Pareto plots can be used to make rational decisions concerning the trade-offs between maximizing the probability of success while minimizing costs and time. The systematic rigor associated with a cost, time and probability of success (CTP) framework is well suited to designing TI projects that require dynamic decision making. The CTP framework also revealed that previously identified 'best' strategies can be improved to be at least twice as effective without increasing time or expenses.

  18. A wing design methodology for low-boom low-drag supersonic business jet

    NASA Astrophysics Data System (ADS)

    Le, Daniel B.

    2009-12-01

    The arguably most critical hindrance to the successful development of a commercial supersonic aircraft is the impact of the sonic boom signature. The sonic boom signature of a supersonic aircraft is predicted using sonic boom theory, which formulates a relationship between the complex three-dimensional geometry of the aircraft to the pressure distribution and decomposes the geometry in terms of simple geometrical components. The supersonic aircraft design process is typically based on boom minimization theory. This theory provides a theoretical equivalent area distribution which should be matched by the conceptual design in order to achieve the pre-determined sonic boom signature. The difference between the target equivalent area distribution and the actual equivalent area distribution is referred to here as the gap distribution. The primary intent of this dissertation is to provide the designer with a systematic and structured approach to designing the aircraft wings with limited changes to the baseline concept while achieving critical design goals. The design process can be easily overwhelmed and may be difficult to evaluate their effectiveness. The wing design is decoupled into two separate processes, one focused on the planform design and the other on the camber design. Moreover, this design methodology supplements the designer by allowing trade studies to be conducted between important design parameters and objectives. The wing planform design methodology incorporates a continuous gradient-based optimization scheme to supplement the design process. This is not meant to substitute the vast amount of knowledge and design decisions that are needed for a successful design. Instead, the numerical optimization helps the designer to refine creative concepts. Last, this dissertation integrates a risk mitigation scheme throughout the wing design process. The design methodology implements minimal design changes to the wing geometry white achieving the target design goal

  19. The methodological quality assessment tools for preclinical and clinical studies, systematic review and meta-analysis, and clinical practice guideline: a systematic review.

    PubMed

    Zeng, Xiantao; Zhang, Yonggang; Kwong, Joey S W; Zhang, Chao; Li, Sheng; Sun, Feng; Niu, Yuming; Du, Liang

    2015-02-01

    To systematically review the methodological assessment tools for pre-clinical and clinical studies, systematic review and meta-analysis, and clinical practice guideline. We searched PubMed, the Cochrane Handbook for Systematic Reviews of Interventions, Joanna Briggs Institute (JBI) Reviewers Manual, Centre for Reviews and Dissemination, Critical Appraisal Skills Programme (CASP), Scottish Intercollegiate Guidelines Network (SIGN), and the National Institute for Clinical Excellence (NICE) up to May 20th, 2014. Two authors selected studies and extracted data; quantitative analysis was performed to summarize the characteristics of included tools. We included a total of 21 assessment tools for analysis. A number of tools were developed by academic organizations, and some were developed by only a small group of researchers. The JBI developed the highest number of methodological assessment tools, with CASP coming second. Tools for assessing the methodological quality of randomized controlled studies were most abundant. The Cochrane Collaboration's tool for assessing risk of bias is the best available tool for assessing RCTs. For cohort and case-control studies, we recommend the use of the Newcastle-Ottawa Scale. The Methodological Index for Non-Randomized Studies (MINORS) is an excellent tool for assessing non-randomized interventional studies, and the Agency for Healthcare Research and Quality (ARHQ) methodology checklist is applicable for cross-sectional studies. For diagnostic accuracy test studies, the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool is recommended; the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk of bias tool is available for assessing animal studies; Assessment of Multiple Systematic Reviews (AMSTAR) is a measurement tool for systematic reviews/meta-analyses; an 18-item tool has been developed for appraising case series studies, and the Appraisal of Guidelines, Research and Evaluation (AGREE

  20. Surface design methodology - challenge the steel

    NASA Astrophysics Data System (ADS)

    Bergman, M.; Rosen, B.-G.; Eriksson, L.; Anderberg, C.

    2014-03-01

    The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or "feeling" for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA.

  1. A Methodology for the Neutronics Design of Space Nuclear Reactors

    SciTech Connect

    King, Jeffrey C.; El-Genk, Mohamed S.

    2004-02-04

    A methodology for the neutronics design of space power reactors is presented. This methodology involves balancing the competing requirements of having sufficient excess reactivity for the desired lifetime, keeping the reactor subcritical at launch and during submersion accidents, and providing sufficient control over the lifetime of the reactor. These requirements are addressed by three reactivity values for a given reactor design: the excess reactivity at beginning of mission, the negative reactivity at shutdown, and the negative reactivity margin in submersion accidents. These reactivity values define the control worth and the safety worth in submersion accidents, used for evaluating the merit of a proposed reactor type and design. The Heat Pipe-Segmented Thermoelectric Module Converters space reactor core design is evaluated and modified based on the proposed methodology. The final reactor core design has sufficient excess reactivity for 10 years of nominal operation at 1.82 MW of fission power and is subcritical at launch and in all water submersion accidents.

  2. Methodological issues and recommendations for systematic reviews of prognostic studies: an example from cardiovascular disease.

    PubMed

    Dretzke, Janine; Ensor, Joie; Bayliss, Sue; Hodgkinson, James; Lordkipanidzé, Marie; Riley, Richard D; Fitzmaurice, David; Moore, David

    2014-12-03

    Prognostic factors are associated with the risk of future health outcomes in individuals with a particular health condition. The prognostic ability of such factors is increasingly being assessed in both primary research and systematic reviews. Systematic review methodology in this area is continuing to evolve, reflected in variable approaches to key methodological aspects. The aim of this article was to (i) explore and compare the methodology of systematic reviews of prognostic factors undertaken for the same clinical question, (ii) to discuss implications for review findings, and (iii) to present recommendations on what might be considered to be 'good practice' approaches. The sample was comprised of eight systematic reviews addressing the same clinical question, namely whether 'aspirin resistance' (a potential prognostic factor) has prognostic utility relative to future vascular events in patients on aspirin therapy for secondary prevention. A detailed comparison of methods around study identification, study selection, quality assessment, approaches to analysis, and reporting of findings was undertaken and the implications discussed. These were summarised into key considerations that may be transferable to future systematic reviews of prognostic factors. Across systematic reviews addressing the same clinical question, there were considerable differences in the numbers of studies identified and overlap between included studies, which could only partially be explained by different study eligibility criteria. Incomplete reporting and differences in terminology within primary studies hampered study identification and selection process across reviews. Quality assessment was highly variable and only one systematic review considered a checklist for studies of prognostic questions. There was inconsistency between reviews in approaches towards analysis, synthesis, addressing heterogeneity and reporting of results. Different methodological approaches may ultimately affect

  3. Solid lubrication design methodology, phase 2

    NASA Technical Reports Server (NTRS)

    Pallini, R. A.; Wedeven, L. D.; Ragen, M. A.; Aggarwal, B. B.

    1986-01-01

    The high temperature performance of solid lubricated rolling elements was conducted with a specially designed traction (friction) test apparatus. Graphite lubricants containing three additives (silver, phosphate glass, and zinc orthophosphate) were evaluated from room temperature to 540 C. Two hard coats were also evaluated. The evaluation of these lubricants, using a burnishing method of application, shows a reasonable transfer of lubricant and wear protection for short duration testing except in the 200 C temperature range. The graphite lubricants containing silver and zinc orthophosphate additives were more effective than the phosphate glass material over the test conditions examined. Traction coefficients ranged from a low of 0.07 to a high of 0.6. By curve fitting the traction data, empirical equations for slope and maximum traction coefficient as a function of contact pressure (P), rolling speed (U), and temperature (T) can be developed for each lubricant. A solid lubricant traction model was incorporated into an advanced bearing analysis code (SHABERTH). For comparison purposes, preliminary heat generation calculations were made for both oil and solid lubricated bearing operation. A preliminary analysis indicated a significantly higher heat generation for a solid lubricated ball bearing in a deep groove configuration. An analysis of a cylindrical roller bearing configuration showed a potential for a low friction solid lubricated bearing.

  4. A systematic and methodological review of interventions for young people experiencing alcohol-related harm.

    PubMed

    Calabria, Bianca; Shakeshaft, Anthony P; Havard, Alys

    2011-08-01

    This review identified published studies evaluating interventions delivered outside educational settings, designed for young people with existing alcohol use problems, or who participate in behaviour that places them at high risk of alcohol-related harm, critiqued their methodology and identified opportunities for new interventions. A systematic search of the peer-reviewed literature interrogated 10 electronic databases using specific search strings, limited to 2005-09. No additional studies were found by a librarian searching other collections and clearing-houses, or by hand-searching review paper reference lists. The 1697 articles identified were reviewed against criteria from the Dictionary for the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies. The methodological quality of existing studies is variable, and needs to be both more rigorous and more consistent. Particular problems include the lack of blinding outcome assessors, a reliance solely on self-report measures, highly variable consent and follow-up rates, infrequent use of intention-to-treat analyses and the absence of any economic or cost analyses. The range of interventions evaluated is currently limited to individually focused approaches, almost exclusively implemented in the United States. There is a great need for more intervention trials for young people at high risk of experiencing alcohol-related harm that are both methodologically rigorous and have a broader community focus, to complement the psychological interventions that currently dominate the relevant literature. Such trials would improve outcomes for high-risk young people themselves and would improve the evidence base, both in their own right and by facilitating future meta-analyses. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

  5. Developing organ-on-a-chip concepts using bio-mechatronic design methodology.

    PubMed

    Christoffersson, Jonas; van Noort, Danny; Mandenius, Carl-Fredrik

    2017-05-26

    Mechatronic design is an engineering methodology for conceiving, configuring and optimising the design of a technical device or product to the needs and requirements of the final user. In this article, we show how the basic principles of this methodology can be exploited for in vitro cell cultures-often referred to as organ-on-a-chip devices. Due to the key role of the biological cells, we have introduced the term bio-mechatronic design, to highlight the complexity of designing a system that should integrate biology, mechanics and electronics in the same device structure. The strength of the mechatronic design is to match the needs of the potential users to a systematic evaluation of overall functional design alternative. It may be especially attractive for organs-on-chips where biological constituents such as cells and tissues in 3D settings and in a fluidic environment should be compared, screened and selected. Through this approach, design solutions ranked to customer needs are generated according to specified criteria, thereby defining the key constraints of the fabrication. As an example, the bio-mechatronic methodology is applied to a liver-on-a-chip based on information extrapolated from previous theoretical and experimental knowledge. It is concluded that the methodology can generate new fabrication solutions for devices, as well as efficient guidelines for refining the design and fabrication of many of today's organ-on-a-chip devices.

  6. Optimal Design and Purposeful Sampling: Complementary Methodologies for Implementation Research.

    PubMed

    Duan, Naihua; Bhaumik, Dulal K; Palinkas, Lawrence A; Hoagwood, Kimberly

    2015-09-01

    Optimal design has been an under-utilized methodology. However, it has significant real-world applications, particularly in mixed methods implementation research. We review the concept and demonstrate how it can be used to assess the sensitivity of design decisions and balance competing needs. For observational studies, this methodology enables selection of the most informative study units. For experimental studies, it entails selecting and assigning study units to intervention conditions in the most informative manner. We blend optimal design methods with purposeful sampling to show how these two concepts balance competing needs when there are multiple study aims, a common situation in implementation research.

  7. Optimal Design and Purposeful Sampling: Complementary Methodologies for Implementation Research

    PubMed Central

    Duan, Naihua; Bhaumik, Dulal K.; Palinkas, Lawrence A.; Hoagwood, Kimberly

    2015-01-01

    Optimal design has been an under-utilized methodology. However, it has significant real-world applications, particularly in mixed methods implementation research. We review the concept and demonstrate how it can be used to assess the sensitivity of design decisions and balance competing needs. For observational studies, this methodology enables selection of the most informative study units. For experimental studies, it entails selecting and assigning study units to intervention conditions in the most informative manner. We blend optimal design methods with purposeful sampling to show how these two concepts balance competing needs when there are multiple study aims, a common situation in implementation research. PMID:25491200

  8. PEM Fuel Cells Redesign Using Biomimetic and TRIZ Design Methodologies

    NASA Astrophysics Data System (ADS)

    Fung, Keith Kin Kei

    Two formal design methodologies, biomimetic design and the Theory of Inventive Problem Solving, TRIZ, were applied to the redesign of a Proton Exchange Membrane (PEM) fuel cell. Proof of concept prototyping was performed on two of the concepts for water management. The liquid water collection with strategically placed wicks concept demonstrated the potential benefits for a fuel cell. Conversely, the periodic flow direction reversal concepts might cause a potential reduction water removal from a fuel cell. The causes of this water removal reduction remain unclear. In additional, three of the concepts generated with biomimetic design were further studied and demonstrated to stimulate more creative ideas in the thermal and water management of fuel cells. The biomimetic design and the TRIZ methodologies were successfully applied to fuel cells and provided different perspectives to the redesign of fuel cells. The methodologies should continue to be used to improve fuel cells.

  9. Hydrogel design of experiments methodology to optimize hydrogel for iPSC-NPC culture.

    PubMed

    Lam, Jonathan; Carmichael, S Thomas; Lowry, William E; Segura, Tatiana

    2015-03-11

    Bioactive signals can be incorporated in hydrogels to direct encapsulated cell behavior. Design of experiments methodology methodically varies the signals systematically to determine the individual and combinatorial effects of each factor on cell activity. Using this approach enables the optimization of three ligands concentrations (RGD, YIGSR, IKVAV) for the survival and differentiation of neural progenitor cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Methodological Innovation in Practice-Based Design Doctorates

    ERIC Educational Resources Information Center

    Yee, Joyce S. R.

    2010-01-01

    This article presents a selective review of recent design PhDs that identify and analyse the methodological innovation that is occurring in the field, in order to inform future provision of research training. Six recently completed design PhDs are used to highlight possible philosophical and practical models that can be adopted by future PhD…

  11. Helicopter-V/STOL dynamic wind and turbulence design methodology

    NASA Technical Reports Server (NTRS)

    Bailey, J. Earl

    1987-01-01

    Aircraft and helicopter accidents due to severe dynamic wind and turbulence continue to present challenging design problems. The development of the current set of design analysis tools for a aircraft wind and turbulence design began in the 1940's and 1950's. The areas of helicopter dynamic wind and turbulence modeling and vehicle response to severe dynamic wind inputs (microburst type phenomena) during takeoff and landing remain as major unsolved design problems from a lack of both environmental data and computational methodology. The development of helicopter and V/STOL dynamic wind and turbulence response computation methology is reviewed, the current state of the design art in industry is outlined, and comments on design methodology are made which may serve to improve future flight vehicle design.

  12. Impact of searching clinical trial registries in systematic reviews of pharmaceutical treatments: methodological systematic review and reanalysis of meta-analyses.

    PubMed

    Baudard, Marie; Yavchitz, Amélie; Ravaud, Philippe; Perrodeau, Elodie; Boutron, Isabelle

    2017-02-17

    Objective To evaluate the impact of searching clinical trial registries in systematic reviews.Design Methodological systematic review and reanalyses of meta-analyses.Data sources Medline was searched to identify systematic reviews of randomised controlled trials (RCTs) assessing pharmaceutical treatments published between June 2014 and January 2015. For all systematic reviews that did not report a trial registry search but reported the information to perform it, the World Health Organization International Trials Registry Platform (WHO ICTRP search portal) was searched for completed or terminated RCTs not originally included in the systematic review.Data extraction For each systematic review, two researchers independently extracted the outcomes analysed, the number of patients included, and the treatment effect estimated. For each RCT identified, two researchers independently determined whether the results were available (ie, posted, published, or available on the sponsor website) and extracted the data. When additional data were retrieved, we reanalysed meta-analyses and calculated the weight of the additional RCTs and the change in summary statistics by comparison with the original meta-analysis.Results Among 223 selected systematic reviews, 116 (52%) did not report a search of trial registries; 21 of these did not report the information to perform the search (key words, search date). A search was performed for 95 systematic reviews; for 54 (57%), no additional RCTs were found and for 41 (43%) 122 additional RCTs were identified. The search allowed for increasing the number of patients by more than 10% in 19 systematic reviews, 20% in 10, 30% in seven, and 50% in four. Moreover, 63 RCTs had results available; the results for 45 could be included in a meta-analysis. 14 systematic reviews including 45 RCTs were reanalysed. The weight of the additional RCTs in the recalculated meta-analyses ranged from 0% to 58% and was greater than 10% in five of 14 systematic

  13. Summarizing systematic reviews: methodological development, conduct and reporting of an umbrella review approach.

    PubMed

    Aromataris, Edoardo; Fernandez, Ritin; Godfrey, Christina M; Holly, Cheryl; Khalil, Hanan; Tungpunkom, Patraporn

    2015-09-01

    With the increase in the number of systematic reviews available, a logical next step to provide decision makers in healthcare with the evidence they require has been the conduct of reviews of existing systematic reviews. Syntheses of existing systematic reviews are referred to by many different names, one of which is an umbrella review. An umbrella review allows the findings of reviews relevant to a review question to be compared and contrasted. An umbrella review's most characteristic feature is that this type of evidence synthesis only considers for inclusion the highest level of evidence, namely other systematic reviews and meta-analyses. A methodology working group was formed by the Joanna Briggs Institute to develop methodological guidance for the conduct of an umbrella review, including diverse types of evidence, both quantitative and qualitative. The aim of this study is to describe the development and guidance for the conduct of an umbrella review. Discussion and testing of the elements of methods for the conduct of an umbrella review were held over a 6-month period by members of a methodology working group. The working group comprised six participants who corresponded via teleconference, e-mail and face-to-face meeting during this development period. In October 2013, the methodology was presented in a workshop at the Joanna Briggs Institute Convention. Workshop participants, review authors and methodologists provided further testing, critique and feedback on the proposed methodology. This study describes the methodology and methods developed for the conduct of an umbrella review that includes published systematic reviews and meta-analyses as the analytical unit of the review. Details are provided regarding the essential elements of an umbrella review, including presentation of the review question in a Population, Intervention, Comparator, Outcome format, nuances of the inclusion criteria and search strategy. A critical appraisal tool with 10 questions to

  14. Systematic Design of Tuned Transmon Qubits

    NASA Astrophysics Data System (ADS)

    Abraham, David; Gambetta, Jay M.; Chow, Jerry M.; Srinivasan, Srikanth; Steffen, Matthias

    2014-03-01

    We demonstrate a systematic method for designing two-dimensional superconducting transmon qubits with highly controllable and reproducible properties, including anharmonicity, resonant frequency and the ratio Ej/Ec. The main source of variation in these qubit properties is shown to be due to spreads in the critical current of the Josephson junction connecting the transmon capacitor pads. This technique is illustrated in a series of qubits with a range of properties, culminating in a design which accurately meets the desired operating point for multiqubit operation, and in addition obtains coherence times 2x higher than previously obtained, using conventional materials and fabrication methods. We acknowledge support from IARPA under contract W911NF-10-1-0324.

  15. Application of an Integrated Methodology for Propulsion and Airframe Control Design to a STOVL Aircraft

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Mattern, Duane

    1994-01-01

    An advanced methodology for integrated flight propulsion control (IFPC) design for future aircraft, which will use propulsion system generated forces and moments for enhanced maneuver capabilities, is briefly described. This methodology has the potential to address in a systematic manner the coupling between the airframe and the propulsion subsystems typical of such enhanced maneuverability aircraft. Application of the methodology to a short take-off vertical landing (STOVL) aircraft in the landing approach to hover transition flight phase is presented with brief description of the various steps in the IFPC design methodology. The details of the individual steps have been described in previous publications and the objective of this paper is to focus on how the components of the control system designed at each step integrate into the overall IFPC system. The full nonlinear IFPC system was evaluated extensively in nonreal-time simulations as well as piloted simulations. Results from the nonreal-time evaluations are presented in this paper. Lessons learned from this application study are summarized in terms of areas of potential improvements in the STOVL IFPC design as well as identification of technology development areas to enhance the applicability of the proposed design methodology.

  16. Application of Resource Description Framework to Personalise Learning: Systematic Review and Methodology

    ERIC Educational Resources Information Center

    Jevsikova, Tatjana; Berniukevicius, Andrius; Kurilovas, Eugenijus

    2017-01-01

    The paper is aimed to present a methodology of learning personalisation based on applying Resource Description Framework (RDF) standard model. Research results are two-fold: first, the results of systematic literature review on Linked Data, RDF "subject-predicate-object" triples, and Web Ontology Language (OWL) application in education…

  17. Enhancing Instructional Design Efficiency: Methodologies Employed by Instructional Designers

    ERIC Educational Resources Information Center

    Roytek, Margaret A.

    2010-01-01

    Instructional systems design (ISD) has been frequently criticised as taking too long to implement, calling for a reduction in cycle time--the time that elapses between project initiation and delivery. While instructional design research has historically focused on increasing "learner" efficiencies, the study of what instructional designers do to…

  18. Enhancing Instructional Design Efficiency: Methodologies Employed by Instructional Designers

    ERIC Educational Resources Information Center

    Roytek, Margaret A.

    2010-01-01

    Instructional systems design (ISD) has been frequently criticised as taking too long to implement, calling for a reduction in cycle time--the time that elapses between project initiation and delivery. While instructional design research has historically focused on increasing "learner" efficiencies, the study of what instructional designers do to…

  19. A design methodology for nonlinear systems containing parameter uncertainty: Application to nonlinear controller design

    NASA Technical Reports Server (NTRS)

    Young, G.

    1982-01-01

    A design methodology capable of dealing with nonlinear systems, such as a controlled ecological life support system (CELSS), containing parameter uncertainty is discussed. The methodology was applied to the design of discrete time nonlinear controllers. The nonlinear controllers can be used to control either linear or nonlinear systems. Several controller strategies are presented to illustrate the design procedure.

  20. Instruments for Assessing Risk of Bias and Other Methodological Criteria of Published Animal Studies: A Systematic Review

    PubMed Central

    Krauth, David; Woodruff, Tracey J.

    2013-01-01

    Background: Results from animal toxicology studies are critical to evaluating the potential harm from exposure to environmental chemicals or the safety of drugs prior to human testing. However, there is significant debate about how to evaluate the methodology and potential biases of the animal studies. There is no agreed-upon approach, and a systematic evaluation of current best practices is lacking. Objective: We performed a systematic review to identify and evaluate instruments for assessing the risk of bias and/or other methodological criteria of animal studies. Method: We searched Medline (January 1966–November 2011) to identify all relevant articles. We extracted data on risk of bias criteria (e.g., randomization, blinding, allocation concealment) and other study design features included in each assessment instrument. Discussion: Thirty distinct instruments were identified, with the total number of assessed risk of bias, methodological, and/or reporting criteria ranging from 2 to 25. The most common criteria assessed were randomization (25/30, 83%), investigator blinding (23/30, 77%), and sample size calculation (18/30, 60%). In general, authors failed to empirically justify why these or other criteria were included. Nearly all (28/30, 93%) of the instruments have not been rigorously tested for validity or reliability. Conclusion: Our review highlights a number of risk of bias assessment criteria that have been empirically tested for animal research, including randomization, concealment of allocation, blinding, and accounting for all animals. In addition, there is a need for empirically testing additional methodological criteria and assessing the validity and reliability of a standard risk of bias assessment instrument. Citation: Krauth D, Woodruff TJ, Bero L. 2013. Instruments for assessing risk of bias and other methodological criteria of published animal studies: a systematic review. Environ Health Perspect 121:985–992 (2013); http://dx.doi.org/10

  1. Top-down methodology in industrial mixed-signals design

    NASA Astrophysics Data System (ADS)

    Liao, E.; Postula, A.; Ding, Y.

    2005-12-01

    Analogue and mixed-signal designs are fast becoming significant in System-On-Chip (SoC) designs as digital computational cores need to interface with the real world. Cellular phones, magnetic disk drives, speech recognition hardware and other 'digital' innovations in fact rely on a core of analogue circuitry. Mature digital CAD tools competently handle the digital portions of SoC designs. This is not true for analogue and mixed-signals components, still designed manually using time-consuming techniques. A good top-down design methodology can drastically reduce the design time of analogue components in SoCs and allow comprehensive functionality verification. This paper contains a critical survey of current design processes and tools, a top-down design case study and introduces MIX-SYN, a new platform for fast-tracking exploration and design time for the analogue and mixed-signals design industry.

  2. Epidemiology characteristics, reporting characteristics, and methodological quality of systematic reviews and meta-analyses on traditional Chinese medicine nursing interventions published in Chinese journals.

    PubMed

    Yang, Min; Jiang, Li; Wang, Aihong; Xu, Guihua

    2017-02-01

    To evaluate the epidemiological characteristics, reporting characteristics, and methodological quality of systematic reviews in the traditional Chinese medicine nursing field published in Chinese journals. The number of systematic reviews in the traditional Chinese medicine nursing field has increased, but their epidemiology, quality, and reporting characteristics have not been assessed completely. We generated an overview of reviews using a narrative approach. Four Chinese databases were searched for systematic reviews from inception to December 2015. The Preferred Reporting Items of Systematic Reviews and Meta-analyses and the Assessment of Multiple Systematic Reviews checklists were adopted to evaluate reporting and methodological quality, respectively. A total of 73 eligible systematic reviews, published from 2005 to 2015, were included. The deficiencies in reporting characteristics mainly lay in the lack of structured abstract or protocol, incomplete reporting of search strategies, study selection, and risk of bias. The deficiencies in methodological quality were reflected in the lack of a priori design and conflict of interest, incomplete literature searches, and assessment of publication bias. The quality of the evaluated reviews was unsatisfactory; attention should be paid to the improvement of reporting and methodological quality in the conduct of systematic reviews.

  3. A methodology for designing aircraft to low sonic boom constraints

    NASA Technical Reports Server (NTRS)

    Mack, Robert J.; Needleman, Kathy E.

    1991-01-01

    A method for designing conceptual supersonic cruise aircraft to meet low sonic boom requirements is outlined and described. The aircraft design is guided through a systematic evolution from initial three view drawing to a final numerical model description, while the designer using the method controls the integration of low sonic boom, high supersonic aerodynamic efficiency, adequate low speed handling, and reasonable structure and materials technologies. Some experience in preliminary aircraft design and in the use of various analytical and numerical codes is required for integrating the volume and lift requirements throughout the design process.

  4. Systematic risk assessment methodology for critical infrastructure elements - Oil and Gas subsectors

    NASA Astrophysics Data System (ADS)

    Gheorghiu, A.-D.; Ozunu, A.

    2012-04-01

    The concern for the protection of critical infrastructure has been rapidly growing in the last few years in Europe. The level of knowledge and preparedness in this field is beginning to develop in a lawfully organized manner, for the identification and designation of critical infrastructure elements of national and European interest. Oil and gas production, refining, treatment, storage and transmission by pipelines facilities, are considered European critical infrastructure sectors, as per Annex I of the Council Directive 2008/114/EC of 8 December 2008 on the identification and designation of European critical infrastructures and the assessment of the need to improve their protection. Besides identifying European and national critical infrastructure elements, member states also need to perform a risk analysis for these infrastructure items, as stated in Annex II of the above mentioned Directive. In the field of risk assessment, there are a series of acknowledged and successfully used methods in the world, but not all hazard identification and assessment methods and techniques are suitable for a given site, situation, or type of hazard. As Theoharidou, M. et al. noted (Theoharidou, M., P. Kotzanikolaou, and D. Gritzalis 2009. Risk-Based Criticality Analysis. In Critical Infrastructure Protection III. Proceedings. Third Annual IFIP WG 11.10 International Conference on Critical Infrastructure Protection. Hanover, New Hampshire, USA, March 23-25, 2009: revised selected papers, edited by C. Palmer and S. Shenoi, 35-49. Berlin: Springer.), despite the wealth of knowledge already created, there is a need for simple, feasible, and standardized criticality analyses. The proposed systematic risk assessment methodology includes three basic steps: the first step (preliminary analysis) includes the identification of hazards (including possible natural hazards) for each installation/section within a given site, followed by a criterial analysis and then a detailed analysis step

  5. Methodological Quality of Systematic Reviews Published in the Urological Literature from 1998 to 2012.

    PubMed

    Corbyons, Katherine; Han, Julia; Neuberger, Molly M; Dahm, Philipp

    2015-11-01

    Systematic reviews synthesize the current best evidence to address a clinical question. Given the growing emphasis on evidence-based clinical practice, systematic reviews are being increasingly sought after and published. We previously reported limitations in the methodological quality of 57 individual systematic reviews published from 1998 to 2008. We provide an update to our previous study, adding systematic reviews published from 2009 to 2012. We systematically searched PubMed® and hand searched the table of contents of 4 major urological journals to identify systematic reviews related to questions of prevention and therapy. Two independent reviewers with prior formal evidence-based medicine training assessed the methodological quality using the validated 11-point AMSTAR (A Measurement Tool to Assess Systematic Reviews) instrument. We performed predefined statistical hypothesis testing for differences by publication period (1998 to 2008 vs 2009 to 2012) and journal of publication. We performed statistical testing using SPSS®, version 23.0 with a 2-sided α of 0.05 using the Student t-test, ANOVA and the chi-square test. A total of 113 systematic reviews published from 2009 to 2012 met study inclusion criteria. The most common topics were oncology (44 reviews or 38.9%), voiding dysfunction (26 or 23.0%) and stones/endourology (13 or 11.5%). The largest contributor was European Urology (46 reviews or 40.7%), followed by BJU International (31 or 27.4%) and The Journal of Urology® (22 or 19.5%). The mean ± SD AMSTAR score for the 2009 to 2012 period was 5.3 ± 2.3 compared to 4.8 ± 2.0 for 1998 to 2008 with a mean difference of 0.5 (95% CI 0.2 to 1.2, p = 0.133). While the number of systematic reviews published in the urological literature has increased substantially, the methodological quality of these studies remains suboptimal. Systematic review authors and editors should make every effort to adhere to well established methodological standards to enhance

  6. The methodological quality of economic evaluations of guideline implementation into clinical practice: a systematic review of empiric studies.

    PubMed

    Hoomans, Ties; Evers, Silvia M A A; Ament, André J H A; Hübben, Mariette W A; van der Weijden, Trudy; Grimshaw, Jeremy M; Severens, Johan L

    2007-01-01

    Despite the emphasis on efficiency of health-care services delivery, there is an imperfect evidence base to inform decisions about whether and how to develop and implement guidelines into clinical practice. In general, studies evaluating the economics of guideline implementation lack methodological rigor. We conducted a systematic review of empiric studies to assess advances in the economic evaluations of guideline implementation. The Cochrane Effective Professional and Organisational Change Group specialized register and the MEDLINE database were searched for English publications between January 1998 and July 2004 that reported objective effect measures and implementation costs. We extracted data on study characteristics, quality of study design, and economic methodology. It was assessed whether the economic evaluations followed methodological guidance. We included 24 economic evaluations, involving 21 controlled trials and three interrupted time series designs. The studies involved varying settings, targeted professionals, targeted behaviors, clinical guidelines, and implementation strategies. Overall, it was difficult to determine the quality of study designs owing to poor reporting. In addition, most economic evaluations were methodologically flawed: studies did not follow guidelines for evaluation design, data collection, and data analysis. The increasing importance of the value for money of providing health care seems to be reflected by an increase in empiric economic evaluations of guideline implementation. Because of the heterogeneity and poor methodological quality of these studies, however, the resulting evidence is still of limited use in decision-making. There seems to be a need for more methodological guidance, especially in terms of data collection and data synthesis, to appropriately evaluate the economics of developing and implementing guidelines into clinical practice.

  7. Implementation of Probabilistic Design Methodology at Tennessee State University

    NASA Technical Reports Server (NTRS)

    Onwubiko, Chinyere

    1996-01-01

    Engineering Design is one of the most important areas in engineering education. Deterministic Design Methodology (DDM) is the only design method that is taught in most engineering schools. This method does not give a direct account of uncertainties in design parameters. Hence, it is impossible to quantify the uncertainties in the response and the actual safety margin remains unknown. The desire for a design methodology tha can identify the primitive (random) variables that affect the structural behavior has led to a growing interest on Probabilistic Design Methodology (PDM). This method is gaining more recognition in industries than in educational institutions. Some of the reasons for the limited use of the PDM at the moment are that many are unaware of its potentials, and most of the software developed for PDM are very recent. The central goal of the PDM project at Tennessee State University is to introduce engineering students to the method. The students participating in the project learn about PDM and the computer codes that are available to the design engineer. The software being used of this project is NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) developed under NASA probabilistic structural analysis program. NESSUS has three different modules which make it a very comprehensive computer code for PDM. A research in technology transfer through course offering in PDM is in effect a Tennessee State University. The aim is to familiarize students with the problem of uncertainties in engineering design. Included in the paper are some projects on PDM carried out by some students and faculty. The areas this method is being applied at the moment include, Design of Gears (spur and worm); Design of Shafts; Design of Statistically Indeterminate Frame Structures; Design of Helical Springs; and Design of Shock Absorbers. Some of the current results of these projects are presented.

  8. Implementation of Probabilistic Design Methodology at Tennessee State University

    NASA Technical Reports Server (NTRS)

    Onwubiko, Chinyere

    1996-01-01

    Engineering Design is one of the most important areas in engineering education. Deterministic Design Methodology (DDM) is the only design method that is taught in most engineering schools. This method does not give a direct account of uncertainties in design parameters. Hence, it is impossible to quantify the uncertainties in the response and the actual safety margin remains unknown. The desire for a design methodology tha can identify the primitive (random) variables that affect the structural behavior has led to a growing interest on Probabilistic Design Methodology (PDM). This method is gaining more recognition in industries than in educational institutions. Some of the reasons for the limited use of the PDM at the moment are that many are unaware of its potentials, and most of the software developed for PDM are very recent. The central goal of the PDM project at Tennessee State University is to introduce engineering students to the method. The students participating in the project learn about PDM and the computer codes that are available to the design engineer. The software being used of this project is NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) developed under NASA probabilistic structural analysis program. NESSUS has three different modules which make it a very comprehensive computer code for PDM. A research in technology transfer through course offering in PDM is in effect a Tennessee State University. The aim is to familiarize students with the problem of uncertainties in engineering design. Included in the paper are some projects on PDM carried out by some students and faculty. The areas this method is being applied at the moment include, Design of Gears (spur and worm); Design of Shafts; Design of Statistically Indeterminate Frame Structures; Design of Helical Springs; and Design of Shock Absorbers. Some of the current results of these projects are presented.

  9. Methodology used in studies reporting chronic kidney disease prevalence: a systematic literature review

    PubMed Central

    Brück, Katharina; Jager, Kitty J.; Dounousi, Evangelia; Kainz, Alexander; Nitsch, Dorothea; Ärnlöv, Johan; Rothenbacher, Dietrich; Browne, Gemma; Capuano, Vincenzo; Ferraro, Pietro Manuel; Ferrieres, Jean; Gambaro, Giovanni; Guessous, Idris; Hallan, Stein; Kastarinen, Mika; Navis, Gerjan; Gonzalez, Alfonso Otero; Palmieri, Luigi; Romundstad, Solfrid; Spoto, Belinda; Stengel, Benedicte; Tomson, Charles; Tripepi, Giovanni; Völzke, Henry; Wiȩcek, Andrzej; Gansevoort, Ron; Schöttker, Ben; Wanner, Christoph; Vinhas, Jose; Zoccali, Carmine; Van Biesen, Wim; Stel, Vianda S.

    2015-01-01

    Background Many publications report the prevalence of chronic kidney disease (CKD) in the general population. Comparisons across studies are hampered as CKD prevalence estimations are influenced by study population characteristics and laboratory methods. Methods For this systematic review, two researchers independently searched PubMed, MEDLINE and EMBASE to identify all original research articles that were published between 1 January 2003 and 1 November 2014 reporting the prevalence of CKD in the European adult general population. Data on study methodology and reporting of CKD prevalence results were independently extracted by two researchers. Results We identified 82 eligible publications and included 48 publications of individual studies for the data extraction. There was considerable variation in population sample selection. The majority of studies did not report the sampling frame used, and the response ranged from 10 to 87%. With regard to the assessment of kidney function, 67% used a Jaffe assay, whereas 13% used the enzymatic assay for creatinine determination. Isotope dilution mass spectrometry calibration was used in 29%. The CKD-EPI (52%) and MDRD (75%) equations were most often used to estimate glomerular filtration rate (GFR). CKD was defined as estimated GFR (eGFR) <60 mL/min/1.73 m2 in 92% of studies. Urinary markers of CKD were assessed in 60% of the studies. CKD prevalence was reported by sex and age strata in 54 and 50% of the studies, respectively. In publications with a primary objective of reporting CKD prevalence, 39% reported a 95% confidence interval. Conclusions The findings from this systematic review showed considerable variation in methods for sampling the general population and assessment of kidney function across studies reporting CKD prevalence. These results are utilized to provide recommendations to help optimize both the design and the reporting of future CKD prevalence studies, which will enhance comparability of study results

  10. An overview and methodological assessment of systematic reviews and meta-analyses of enhanced recovery programmes in colorectal surgery

    PubMed Central

    Chambers, Duncan; Paton, Fiona; Wilson, Paul; Eastwood, Alison; Craig, Dawn; Fox, Dave; Jayne, David; McGinnes, Erika

    2014-01-01

    Objectives To identify and critically assess the extent to which systematic reviews of enhanced recovery programmes for patients undergoing colorectal surgery differ in their methodology and reported estimates of effect. Design Review of published systematic reviews. We searched the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA) Database from 1990 to March 2013. Systematic reviews of enhanced recovery programmes for patients undergoing colorectal surgery were eligible for inclusion. Primary and secondary outcome measures The primary outcome was length of hospital stay. We assessed changes in pooled estimates of treatment effect over time and how these might have been influenced by decisions taken by researchers as well as by the availability of new trials. The quality of systematic reviews was assessed using the Centre for Reviews and Dissemination (CRD) DARE critical appraisal process. Results 10 systematic reviews were included. Systematic reviews of randomised controlled trials have consistently shown a reduction in length of hospital stay with enhanced recovery compared with traditional care. The estimated effect tended to increase from 2006 to 2010 as more trials were published but has not altered significantly in the most recent review, despite the inclusion of several unique trials. The best estimate appears to be an average reduction of around 2.5 days in primary postoperative length of stay. Differences between reviews reflected differences in interpretation of inclusion criteria, searching and analytical methods or software. Conclusions Systematic reviews of enhanced recovery programmes show a high level of research waste, with multiple reviews covering identical or very similar groups of trials. Where multiple reviews exist on a topic, interpretation may require careful attention to apparently minor differences between reviews. Researchers can help readers by

  11. A bio-inspired EAP actuator design methodology

    NASA Astrophysics Data System (ADS)

    Fernandez, Diego; Moreno, Luis; Baselga, Juan

    2005-05-01

    Current EAP actuator sheets or fibers perform reasonable well in the centimeter and mN range, but are not practical for larger force and deformation requirements. In order to make EAP actuators technology scalable a design methodology for polymer actuators is required. Design variables, optimization formulas and a general architecture are required, as it is usual in electromagnetic or hydraulic actuator design. This will allow the development of large EAP actuators specifically designed for a particular application. It will also help to enhance the EAP material final performance. This approach is not new, it is found in Nature. Skeletal muscle architecture has a profound influence on muscle force-generating properties and functionality. Based on existing literature on skeletal muscle biomechanics, the Nature design philosophy is inferred. Formulas and curves employed by Nature in the design of muscles are presented. Design units such as fiber, tendon, aponeurosis, and motor unit are compared with the equivalent design units to be taken into account in the design of EAP actuators. Finally a complete design methodology for the design of actuators based on multiple EAP fiber is proposed. In addition, the procedure gives an idea of the required parameters that must be clearly modeled and characterized at EAP material level.

  12. A methodological quality synthesis of systematic reviews on computer-mediated continuing education for healthcare providers.

    PubMed

    Militello, Lisa K; Gance-Cleveland, Bonnie; Aldrich, Heather; Kamal, Rabah

    2014-06-01

    Healthcare providers use continuing education (CE) to meet professional development requirements and to ensure optimal patient care. There has been a dramatic increase in computer-mediated CE (CMCE) programs. To synthesize the literature regarding the current state of the science on the efficacy of CMCE for healthcare professionals, particularly as it relates to provider learning and patient outcomes. Specifically, this review assesses the methodological quality of existing systematic reviews and meta-analyses. A literature search was conducted using Cochrane Library, PubMed, and CINAHL. Review articles evaluating the efficacy of CMCE for healthcare providers were included. Publications were searched between 2002 and 2013 and limited to those printed in English. An objective measurement tool, AMSTAR, was used to assess the methodological quality of each review. AMSTAR is an 11-item instrument, in which individual criteria were evaluated and a composite score of all 11 components was determined for each review. Outcomes of each review were also categorized based on Kirkpatrick's levels for summative evaluation: (i) Learner satisfaction, (ii) Learning outcomes, (iii) Performance improvement, (iv) Patient/health outcomes. Starting with 231 articles, 11 met the inclusion criteria for this evaluation. AMSTAR quality scores of the reviews ranged from 7 to 11, with 11 indicating the strongest quality. Although weak research design of many studies and heterogeneous topics covered make summative evaluations difficult, there were some common themes covered in the articles reviewed. Healthcare providers were largely satisfied with using CMCE programs. Overall, the studies comparing CMCE to traditional CE methods found the impact on learning outcomes to be comparable, with neither method necessarily superior. Additionally, all reviews lacked evaluation of practice outcomes. While results of this review show promise for CMCE, further evaluation and more rigorously conducted

  13. Prognostics and health management design for rotary machinery systems—Reviews, methodology and applications

    NASA Astrophysics Data System (ADS)

    Lee, Jay; Wu, Fangji; Zhao, Wenyu; Ghaffari, Masoud; Liao, Linxia; Siegel, David

    2014-01-01

    Much research has been conducted in prognostics and health management (PHM), an emerging field in mechanical engineering that is gaining interest from both academia and industry. Most of these efforts have been in the area of machinery PHM, resulting in the development of many algorithms for this particular application. The majority of these algorithms concentrate on applications involving common rotary machinery components, such as bearings and gears. Knowledge of this prior work is a necessity for any future research efforts to be conducted; however, there has not been a comprehensive overview that details previous and on-going efforts in PHM. In addition, a systematic method for developing and deploying a PHM system has yet to be established. Such a method would enable rapid customization and integration of PHM systems for diverse applications. To address these gaps, this paper provides a comprehensive review of the PHM field, followed by an introduction of a systematic PHM design methodology, 5S methodology, for converting data to prognostics information. This methodology includes procedures for identifying critical components, as well as tools for selecting the most appropriate algorithms for specific applications. Visualization tools are presented for displaying prognostics information in an appropriate fashion for quick and accurate decision making. Industrial case studies are included in this paper to show how this methodology can help in the design of an effective PHM system.

  14. Extensibility of a linear rapid robust design methodology

    NASA Astrophysics Data System (ADS)

    Steinfeldt, Bradley A.; Braun, Robert D.

    2016-05-01

    The extensibility of a linear rapid robust design methodology is examined. This analysis is approached from a computational cost and accuracy perspective. The sensitivity of the solution's computational cost is examined by analysing effects such as the number of design variables, nonlinearity of the CAs, and nonlinearity of the response in addition to several potential complexity metrics. Relative to traditional robust design methods, the linear rapid robust design methodology scaled better with the size of the problem and had performance that exceeded the traditional techniques examined. The accuracy of applying a method with linear fundamentals to nonlinear problems was examined. It is observed that if the magnitude of nonlinearity is less than 1000 times that of the nominal linear response, the error associated with applying successive linearization will result in ? errors in the response less than 10% compared to the full nonlinear error.

  15. Viability, Advantages and Design Methodologies of M-Learning Delivery

    ERIC Educational Resources Information Center

    Zabel, Todd W.

    2010-01-01

    The purpose of this study was to examine the viability and principle design methodologies of Mobile Learning models in developing regions. Demographic and market studies were utilized to determine the viability of M-Learning delivery as well as best uses for such technologies and methods given socioeconomic and political conditions within the…

  16. Chicken or Egg? Communicative Methodology or Communicative Syllabus Design.

    ERIC Educational Resources Information Center

    Yalden, Janice

    A consensus has emerged on many issues in communicative language teaching, but one question that needs attention is the question of what ought to constitute the appropriate starting point in the design and implementation of a second language program. Two positions to consider are the following: first, the development of communicative methodology,…

  17. Chicken or Egg? Communicative Methodology or Communicative Syllabus Design.

    ERIC Educational Resources Information Center

    Yalden, Janice

    A consensus has emerged on many issues in communicative language teaching, but one question that needs attention is the question of what ought to constitute the appropriate starting point in the design and implementation of a second language program. Two positions to consider are the following: first, the development of communicative methodology,…

  18. Comparison of methodological quality of positive versus negative comparative studies published in Indian medical journals: a systematic review

    PubMed Central

    Charan, Jaykaran; Chaudhari, Mayur; Jackson, Ryan; Mhaskar, Rahul; Reljic, Tea; Kumar, Ambuj

    2015-01-01

    Objectives Published negative studies should have the same rigour of methodological quality as studies with positive findings. However, the methodological quality of negative versus positive studies is not known. The objective was to assess the reported methodological quality of positive versus negative studies published in Indian medical journals. Design A systematic review (SR) was performed of all comparative studies published in Indian medical journals with a clinical science focus and impact factor >1 between 2011 and 2013. The methodological quality of randomised controlled trials (RCTs) was assessed using the Cochrane risk of bias tool, and the Newcastle-Ottawa scale for observational studies. The results were considered positive if the primary outcome was statistically significant and negative otherwise. When the primary outcome was not specified, we used data on the first outcome reported in the history followed by the results section. Differences in various methodological quality domains between positive versus negative studies were assessed by Fisher's exact test. Results Seven journals with 259 comparative studies were included in this SR. 24% (63/259) were RCTs, 24% (63/259) cohort studies, and 49% (128/259) case–control studies. 53% (137/259) of studies explicitly reported the primary outcome. Five studies did not report sufficient data to enable us to determine if results were positive or negative. Statistical significance was determined by p value in 78.3% (199/254), CI in 2.8% (7/254), both p value and CI in 11.8% (30/254), and only descriptive in 6.3% (16/254) of studies. The overall methodological quality was poor and no statistically significant differences between reporting of methodological quality were detected between studies with positive versus negative findings. Conclusions There was no difference in the reported methodological quality of positive versus negative studies. However, the uneven reporting of positive versus negative studies

  19. A computer simulator for development of engineering system design methodologies

    NASA Technical Reports Server (NTRS)

    Padula, S. L.; Sobieszczanski-Sobieski, J.

    1987-01-01

    A computer program designed to simulate and improve engineering system design methodology is described. The simulator mimics the qualitative behavior and data couplings occurring among the subsystems of a complex engineering system. It eliminates the engineering analyses in the subsystems by replacing them with judiciously chosen analytical functions. With the cost of analysis eliminated, the simulator is used for experimentation with a large variety of candidate algorithms for multilevel design optimization to choose the best ones for the actual application. Thus, the simulator serves as a development tool for multilevel design optimization strategy. The simulator concept, implementation, and status are described and illustrated with examples.

  20. Tornado missile simulation and design methodology. Volume 1: simulation methodology, design applications, and TORMIS computer code. Final report

    SciTech Connect

    Twisdale, L.A.; Dunn, W.L.

    1981-08-01

    A probabilistic methodology has been developed to predict the probabilities of tornado-propelled missiles impacting and damaging nuclear power plant structures. Mathematical models of each event in the tornado missile hazard have been developed and sequenced to form an integrated, time-history simulation methodology. The models are data based where feasible. The data include documented records of tornado occurrence, field observations of missile transport, results of wind tunnel experiments, and missile impact tests. Probabilistic Monte Carlo techniques are used to estimate the risk probabilities. The methodology has been encoded in the TORMIS computer code to facilitate numerical analysis and plant-specific tornado missile probability assessments. Sensitivity analyses have been performed on both the individual models and the integrated methodology, and risk has been assessed for a hypothetical nuclear power plant design case study.

  1. A design and implementation methodology for diagnostic systems

    NASA Technical Reports Server (NTRS)

    Williams, Linda J. F.

    1988-01-01

    A methodology for design and implementation of diagnostic systems is presented. Also discussed are the advantages of embedding a diagnostic system in a host system environment. The methodology utilizes an architecture for diagnostic system development that is hierarchical and makes use of object-oriented representation techniques. Additionally, qualitative models are used to describe the host system components and their behavior. The methodology architecture includes a diagnostic engine that utilizes a combination of heuristic knowledge to control the sequence of diagnostic reasoning. The methodology provides an integrated approach to development of diagnostic system requirements that is more rigorous than standard systems engineering techniques. The advantages of using this methodology during various life cycle phases of the host systems (e.g., National Aerospace Plane (NASP)) include: the capability to analyze diagnostic instrumentation requirements during the host system design phase, a ready software architecture for implementation of diagnostics in the host system, and the opportunity to analyze instrumentation for failure coverage in safety critical host system operations.

  2. Methodological quality assessment of paper-based systematic reviews published in oral health.

    PubMed

    Wasiak, J; Shen, A Y; Tan, H B; Mahar, R; Kan, G; Khoo, W R; Faggion, C M

    2016-04-01

    This study aimed to conduct a methodological assessment of paper-based systematic reviews (SR) published in oral health using a validated checklist. A secondary objective was to explore temporal trends on methodological quality. Two electronic databases (OVID Medline and OVID EMBASE) were searched for paper-based SR of interventions published in oral health from inception to October 2014. Manual searches of the reference lists of paper-based SR were also conducted. Methodological quality of included paper-based SR was assessed using an 11-item questionnaire, Assessment of Multiple Systematic Reviews (AMSTAR) checklist. Methodological quality was summarized using the median and inter-quartile range (IQR) of the AMSTAR score over different categories and time periods. A total of 643 paper-based SR were included. The overall median AMSTAR score was 4 (IQR 2-6). The highest median score (5) was found in the pain dentistry and periodontology fields, while the lowest median score (3) was found in implant dentistry, restorative dentistry, oral medicine, and prosthodontics. The number of paper-based SR per year and the median AMSTAR score increased over time (median score in 1990s was 2 (IQR 2-3), 2000s was 4 (IQR 2-5), and 2010 onwards was 5 (IQR 3-6)). Although the methodological quality of paper-based SR published in oral health has improved in the last few years, there is still scope for improving quality in most evaluated dental specialties. Large-scale assessment of methodological quality of dental SR highlights areas of methodological strengths and weaknesses that can be targeted in future publications to encourage better quality review methodology.

  3. Neuropsychological investigations in obsessive-compulsive disorder: A systematic review of methodological challenges.

    PubMed

    Abramovitch, Amitai; Mittelman, Andrew; Tankersley, Amelia P; Abramowitz, Jonathan S; Schweiger, Avraham

    2015-07-30

    The inconsistent nature of the neuropsychology literature pertaining to obsessive-compulsive disorder (OCD) has long been recognized. However, individual studies, systematic reviews, and recent meta-analytic reviews were unsuccessful in establishing a consensus regarding a disorder-specific neuropsychological profile. In an attempt to identify methodological factors that may contribute to the inconsistency that is characteristic of this body of research, a systematic review of methodological factors in studies comparing OCD patients and non-psychiatric controls on neuropsychological tests was conducted. This review covered 115 studies that included nearly 3500 patients. Results revealed a range of methodological weaknesses. Some of these weaknesses have been previously noted in the broader neuropsychological literature, while some are more specific to psychiatric disorders, and to OCD. These methodological shortcomings have the potential to hinder the identification of a specific neuropsychological profile associated with OCD as well as to obscure the association between neurocognitive dysfunctions and contemporary neurobiological models. Rectifying these weaknesses may facilitate replicability, and promote our ability to extract cogent, meaningful, and more unified inferences regarding the neuropsychology of OCD. To that end, we present a set of methodological recommendations to facilitate future neuropsychology research in psychiatric disorders in general, and in OCD in particular.

  4. FOREWORD: Computational methodologies for designing materials Computational methodologies for designing materials

    NASA Astrophysics Data System (ADS)

    Rahman, Talat S.

    2009-02-01

    It would be fair to say that in the past few decades, theory and computer modeling have played a major role in elucidating the microscopic factors that dictate the properties of functional novel materials. Together with advances in experimental techniques, theoretical methods are becoming increasingly capable of predicting properties of materials at different length scales, thereby bringing in sight the long-sought goal of designing material properties according to need. Advances in computer technology and their availability at a reasonable cost around the world have made tit all the more urgent to disseminate what is now known about these modern computational techniques. In this special issue on computational methodologies for materials by design we have tried to solicit articles from authors whose works collectively represent the microcosm of developments in the area. This turned out to be a difficult task for a variety of reasons, not the least of which is space limitation in this special issue. Nevertheless, we gathered twenty articles that represent some of the important directions in which theory and modeling are proceeding in the general effort to capture the ability to produce materials by design. The majority of papers presented here focus on technique developments that are expected to uncover further the fundamental processes responsible for material properties, and for their growth modes and morphological evolutions. As for material properties, some of the articles here address the challenges that continue to emerge from attempts at accurate descriptions of magnetic properties, of electronically excited states, and of sparse matter, all of which demand new looks at density functional theory (DFT). I should hasten to add that much of the success in accurate computational modeling of materials emanates from the remarkable predictive power of DFT, without which we would not be able to place the subject on firm theoretical grounds. As we know and will also

  5. Computer aided die design: A new open-source methodology

    NASA Astrophysics Data System (ADS)

    Carneiro, Olga Sousa; Rajkumar, Ananth; Ferrás, Luís Lima; Fernandes, Célio; Sacramento, Alberto; Nóbrega, João Miguel

    2017-05-01

    In this work we present a detailed description of how to use open source based computer codes to aid the design of complex profile extrusion dies, aiming to improve its flow distribution. The work encompasses the description of the overall open-source die design methodology, the implementation of the energy conservation equation in an existing OpenFOAM® solver, which will be then capable of simulating the steady non-isothermal flow of an incompressible generalized Newtonian fluid, and two case studies to illustrate the capabilities and practical usefulness of the developed methodology. The results obtained with these case studies, used to solve real industrial problems, demonstrate that the computational design aid is an excellent alternative, from economical and technical points of view, to the experimental trial-and-error procedure commonly used in industry.

  6. Engineering design methodology for bio-mechatronic products.

    PubMed

    Derelöv, Micael; Detterfelt, Jonas; Björkman, Mats; Mandenius, Carl-Fredrik

    2008-01-01

    Four complex biotechnology products/product systems (a protein purification system, a bioreactor system, a surface plasmon resonance biosensor, and an enzymatic glucose analyzer) are analyzed using conceptual design principles. A design model well-known in mechanical system design, the Hubka-Eder (HE) model, is adapted to biotechnology products that exemplify combined technical systems of mechanical, electronic, and biological components, here referred to as bio-mechatronic systems. The analysis concludes that an extension of the previous HE model with a separate biological systems entity significantly contributes to facilitating the functional and systematic analyses of bio-mechatronic systems.

  7. A bioclimatic design methodology for urban outdoor spaces

    NASA Astrophysics Data System (ADS)

    Swaid, H.; Bar-El, M.; Hoffman, M. E.

    1993-03-01

    The development of a bioclimatic urban design methodology is described. The cluster thermal time constant ( CTTC) model for predicting street-level urban air temperature variations is coupled with the wind-profile power law and the index of thermal stress (ITS.) for human comfort. The CTTC model and the power law produce the diurnal air temperature and wind speed variations in various canyonlike urban forms. The thermal comfort requirements for lightly-dressed, moderately-walking/seated persons in the outdoor space in summer are then obtained using the ITS. model. The proposed methodology enables a first-order assessment of the climatic implications of different features of the physical structure of the city such as street orientation, canyon height-to-width ratio, building density, and street shading. The application of the proposed methodology is demonstrated for Tel Aviv.

  8. A robust optimization methodology for preliminary aircraft design

    NASA Astrophysics Data System (ADS)

    Prigent, S.; Maréchal, P.; Rondepierre, A.; Druot, T.; Belleville, M.

    2016-05-01

    This article focuses on a robust optimization of an aircraft preliminary design under operational constraints. According to engineers' know-how, the aircraft preliminary design problem can be modelled as an uncertain optimization problem whose objective (the cost or the fuel consumption) is almost affine, and whose constraints are convex. It is shown that this uncertain optimization problem can be approximated in a conservative manner by an uncertain linear optimization program, which enables the use of the techniques of robust linear programming of Ben-Tal, El Ghaoui, and Nemirovski [Robust Optimization, Princeton University Press, 2009]. This methodology is then applied to two real cases of aircraft design and numerical results are presented.

  9. Aerodynamic configuration design using response surface methodology analysis

    NASA Astrophysics Data System (ADS)

    Engelund, Walter C.; Stanley, Douglas O.; Lepsch, Roger A.; McMillin, Mark M.; Unal, Resit

    1993-08-01

    An investigation has been conducted to determine a set of optimal design parameters for a single-stage-to-orbit reentry vehicle. Several configuration geometry parameters which had a large impact on the entry vehicle flying characteristics were selected as design variables: the fuselage fineness ratio, the nose to body length ratio, the nose camber value, the wing planform area scale factor, and the wing location. The optimal geometry parameter values were chosen using a response surface methodology (RSM) technique which allowed for a minimum dry weight configuration design that met a set of aerodynamic performance constraints on the landing speed, and on the subsonic, supersonic, and hypersonic trim and stability levels. The RSM technique utilized, specifically the central composite design method, is presented, along with the general vehicle conceptual design process. Results are presented for an optimized configuration along with several design trade cases.

  10. Aerodynamic configuration design using response surface methodology analysis

    NASA Technical Reports Server (NTRS)

    Engelund, Walter C.; Stanley, Douglas O.; Lepsch, Roger A.; Mcmillin, Mark M.; Unal, Resit

    1993-01-01

    An investigation has been conducted to determine a set of optimal design parameters for a single-stage-to-orbit reentry vehicle. Several configuration geometry parameters which had a large impact on the entry vehicle flying characteristics were selected as design variables: the fuselage fineness ratio, the nose to body length ratio, the nose camber value, the wing planform area scale factor, and the wing location. The optimal geometry parameter values were chosen using a response surface methodology (RSM) technique which allowed for a minimum dry weight configuration design that met a set of aerodynamic performance constraints on the landing speed, and on the subsonic, supersonic, and hypersonic trim and stability levels. The RSM technique utilized, specifically the central composite design method, is presented, along with the general vehicle conceptual design process. Results are presented for an optimized configuration along with several design trade cases.

  11. Changes in Clinical Trials Methodology Over Time: A Systematic Review of Six Decades of Research in Psychopharmacology

    PubMed Central

    Brunoni, André R.; Tadini, Laura; Fregni, Felipe

    2010-01-01

    Background There have been many changes in clinical trials methodology since the introduction of lithium and the beginning of the modern era of psychopharmacology in 1949. The nature and importance of these changes have not been fully addressed to date. As methodological flaws in trials can lead to false-negative or false-positive results, the objective of our study was to evaluate the impact of methodological changes in psychopharmacology clinical research over the past 60 years. Methodology/Principal Findings We performed a systematic review from 1949 to 2009 on MEDLINE and Web of Science electronic databases, and a hand search of high impact journals on studies of seven major drugs (chlorpromazine, clozapine, risperidone, lithium, fluoxetine and lamotrigine). All controlled studies published 100 months after the first trial were included. Ninety-one studies met our inclusion criteria. We analyzed the major changes in abstract reporting, study design, participants' assessment and enrollment, methodology and statistical analysis. Our results showed that the methodology of psychiatric clinical trials changed substantially, with quality gains in abstract reporting, results reporting, and statistical methodology. Recent trials use more informed consent, periods of washout, intention-to-treat approach and parametric tests. Placebo use remains high and unchanged over time. Conclusions/Significance Clinical trial quality of psychopharmacological studies has changed significantly in most of the aspects we analyzed. There was significant improvement in quality reporting and internal validity. These changes have increased study efficiency; however, there is room for improvement in some aspects such as rating scales, diagnostic criteria and better trial reporting. Therefore, despite the advancements observed, there are still several areas that can be improved in psychopharmacology clinical trials. PMID:20209133

  12. Reporting of various methodological and statistical parameters in negative studies published in prominent Indian Medical Journals: a systematic review.

    PubMed

    Charan, J; Saxena, D

    2014-01-01

    Biased negative studies not only reflect poor research effort but also have an impact on 'patient care' as they prevent further research with similar objectives, leading to potential research areas remaining unexplored. Hence, published 'negative studies' should be methodologically strong. All parameters that may help a reader to judge validity of results and conclusions should be reported in published negative studies. There is a paucity of data on reporting of statistical and methodological parameters in negative studies published in Indian Medical Journals. The present systematic review was designed with an aim to critically evaluate negative studies published in prominent Indian Medical Journals for reporting of statistical and methodological parameters. Systematic review. All negative studies published in 15 Science Citation Indexed (SCI) medical journals published from India were included in present study. Investigators involved in the study evaluated all negative studies for the reporting of various parameters. Primary endpoints were reporting of "power" and "confidence interval." Power was reported in 11.8% studies. Confidence interval was reported in 15.7% studies. Majority of parameters like sample size calculation (13.2%), type of sampling method (50.8%), name of statistical tests (49.1%), adjustment of multiple endpoints (1%), post hoc power calculation (2.1%) were reported poorly. Frequency of reporting was more in clinical trials as compared to other study designs and in journals having impact factor more than 1 as compared to journals having impact factor less than 1. Negative studies published in prominent Indian medical journals do not report statistical and methodological parameters adequately and this may create problems in the critical appraisal of findings reported in these journals by its readers.

  13. ProSAR: a new methodology for combinatorial library design.

    PubMed

    Chen, Hongming; Börjesson, Ulf; Engkvist, Ola; Kogej, Thierry; Svensson, Mats A; Blomberg, Niklas; Weigelt, Dirk; Burrows, Jeremy N; Lange, Tim

    2009-03-01

    A method is introduced for performing reagent selection for chemical library design based on topological (2D) pharmacophore fingerprints. Optimal reagent selection is achieved by optimizing the Shannon entropy of the 2D pharmacophore distribution for the reagent set. The method, termed ProSAR, is therefore expected to enumerate compounds that could serve as a good starting point for deriving a structure activity relationship (SAR) in combinatorial library design. This methodology is exemplified by library design examples where the active compounds were already known. The results show that most of the pharmacophores on the substituents for the active compounds are covered by the designed library. This strategy is further expanded to include product property profiles for aqueous solubility, hERG risk assessment, etc. in the optimization process so that the reagent pharmacophore diversity and the product property profile are optimized simultaneously via a genetic algorithm. This strategy is applied to a two-dimensional library design example and compared with libraries designed by a diversity based strategy which minimizes the average ensemble Tanimoto similarity. Our results show that by using the PSAR methodology, libraries can be designed with simultaneously good pharmacophore coverage and product property profile.

  14. Methodological quality and descriptive characteristics of prosthodontic-related systematic reviews.

    PubMed

    Aziz, T; Compton, S; Nassar, U; Matthews, D; Ansari, K; Flores-Mir, C

    2013-04-01

    Ideally, healthcare systematic reviews (SRs) should be beneficial to practicing professionals in making evidence-based clinical decisions. However, the conclusions drawn from SRs are directly related to the quality of the SR and of the included studies. The aim was to investigate the methodological quality and key descriptive characteristics of SRs published in prosthodontics. Methodological quality was analysed using the Assessment of Multiple Reviews (AMSTAR) tool. Several electronic resources (MEDLINE, EMBASE, Web of Science and American Dental Association's Evidence-based Dentistry website) were searched. In total 106 SRs were located. Key descriptive characteristics and methodological quality features were gathered and assessed, and descriptive and inferential statistical testing performed. Most SRs in this sample originated from the European continent followed by North America. Two to five authors conducted most SRs; the majority was affiliated with academic institutions and had prior experience publishing SRs. The majority of SRs were published in specialty dentistry journals, with implant or implant-related topics, the primary topics of interest for most. According to AMSTAR, most quality aspects were adequately fulfilled by less than half of the reviews. Publication bias and grey literature searches were the most poorly adhered components. Overall, the methodological quality of the prosthodontic-related systematic was deemed limited. Future recommendations would include authors to have prior training in conducting SRs and for journals to include a universal checklist that should be adhered to address all key characteristics of an unbiased SR process. © 2013 Blackwell Publishing Ltd.

  15. Development of a Design Methodology for Reconfigurable Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.; McLean, C.

    2000-01-01

    A methodology is presented for the design of flight control systems that exhibit stability and performance-robustness in the presence of actuator failures. The design is based upon two elements. The first element consists of a control law that will ensure at least stability in the presence of a class of actuator failures. This law is created by inner-loop, reduced-order, linear dynamic inversion, and outer-loop compensation based upon Quantitative Feedback Theory. The second element consists of adaptive compensators obtained from simple and approximate time-domain identification of the dynamics of the 'effective vehicle' with failed actuator(s). An example involving the lateral-directional control of a fighter aircraft is employed both to introduce the proposed methodology and to demonstrate its effectiveness and limitations.

  16. An automated methodology development. [software design for combat simulation

    NASA Technical Reports Server (NTRS)

    Hawley, L. R.

    1985-01-01

    The design methodology employed in testing the applicability of Ada in large-scale combat simulations is described. Ada was considered as a substitute for FORTRAN to lower life cycle costs and ease the program development efforts. An object-oriented approach was taken, which featured definitions of military targets, the capability of manipulating their condition in real-time, and one-to-one correlation between the object states and real world states. The simulation design process was automated by the problem statement language (PSL)/problem statement analyzer (PSA). The PSL/PSA system accessed the problem data base directly to enhance the code efficiency by, e.g., eliminating non-used subroutines, and provided for automated report generation, besides allowing for functional and interface descriptions. The ways in which the methodology satisfied the responsiveness, reliability, transportability, modifiability, timeliness and efficiency goals are discussed.

  17. An automated methodology development. [software design for combat simulation

    NASA Technical Reports Server (NTRS)

    Hawley, L. R.

    1985-01-01

    The design methodology employed in testing the applicability of Ada in large-scale combat simulations is described. Ada was considered as a substitute for FORTRAN to lower life cycle costs and ease the program development efforts. An object-oriented approach was taken, which featured definitions of military targets, the capability of manipulating their condition in real-time, and one-to-one correlation between the object states and real world states. The simulation design process was automated by the problem statement language (PSL)/problem statement analyzer (PSA). The PSL/PSA system accessed the problem data base directly to enhance the code efficiency by, e.g., eliminating non-used subroutines, and provided for automated report generation, besides allowing for functional and interface descriptions. The ways in which the methodology satisfied the responsiveness, reliability, transportability, modifiability, timeliness and efficiency goals are discussed.

  18. Design methodology of an automated scattering measurement facility

    NASA Astrophysics Data System (ADS)

    Mazur, D. G.

    1985-12-01

    This thesis addresses the design methodology surrounding an automated scattering measurement facility. A brief historical survey of radar cross-section (RCS) measurements is presented. The electromagnetic theory associated with a continuous wave (CW) background cancellation technique for measuring RCS is discussed as background. In addition, problems associated with interfacing test equipment, data storage and output are addressed. The facility used as a model for this thesis is located at the Air Force Institute of Technology, WPARB, OH. The design methodology applies to any automated scattering measurement facility. A software package incorporating features that enhance the operation of AFIT's facility by students is presented. Finally, sample output from the software package illustrate formats for displaying RCS data.

  19. Assessment of the methodological quality of systematic reviews published in the urological literature from 1998 to 2008.

    PubMed

    MacDonald, Susan L; Canfield, Steven E; Fesperman, Susan F; Dahm, Philipp

    2010-08-01

    Well done systematic reviews provide the highest quality evidence for clinical questions of therapeutic effectiveness. We assessed the methodological quality of systematic reviews in the urological literature. We systematically investigated all systematic reviews published in 4 major urological journals from 1998 to 2008. Studies were identified using a predefined search strategy in PubMed and confirmed by a hand search of journal tables of contents. A validated 11-point instrument to assess the methodological quality of systematic reviews was applied by 2 independent reviewers after a pilot testing phase. Disagreements were discussed and resolved by consensus. The systematic literature search identified 217 individual systematic reviews, of which 57 ultimately met study eligibility criteria. Ten (17.5%), 20 (35.1%) and 27 (47.4%) systematic reviews were published in 1998 to 2001, 2002 to 2005 and 2006 to 2008, respectively. Using the measurement tool to assess systematic reviews the mean +/- SD score was 4.8 +/- 2.0 points. Fewer than half of all systematic reviews performed a systematic literature search that included at least 2 databases (49.1%) or unpublished studies (31.6%), or provided a list of included and excluded studies (45.6%). Of the systematic reviews 63.2% assessed and documented the methodological quality of included studies. Systematic reviews with The Cochrane Collaboration authorship affiliation had a higher mean score than those with no such reported affiliation (6.5 +/- 1.2 vs 4.4 +/- 1.9 points, p <0.001). Results suggest that an increasing number of systematic reviews are published in the urological literature. However, many systematic reviews fail to meet established methodological standards, raising concerns about validity. Increased efforts are indicated to promote quality standards for performing systematic reviews among the authors and readership of the urological literature. Copyright (c) 2010 American Urological Association Education

  20. The use of the cluster randomized crossover design in clinical trials: protocol for a systematic review

    PubMed Central

    2014-01-01

    Background The cluster randomized crossover (CRXO) design is gaining popularity in trial settings where individual randomization or parallel group cluster randomization is not feasible or practical. In a CRXO trial, not only are clusters of individuals rather than individuals themselves randomized to trial arms, but also each cluster participates in each arm of the trial at least once in separate periods of time. We will review publications of clinical trials undertaken in humans that have used the CRXO design. The aim of this systematic review is to summarize, as reported: the motivations for using the CRXO design, the values of the CRXO design parameters, the justification and methodology for the sample size calculations and analyses, and the quality of reporting the CRXO design aspects. Methods/Design We will identify reports of CRXO trials by systematically searching MEDLINE, PubMed, Cochrane Methodology Register, EMBASE, and CINAHL Plus. In addition, we will search for methodological articles that describe the CRXO design and conduct citation searches to identify any further CRXO trials. The references of all eligible trials will also be searched. We will screen the identified abstracts, and retrieve and assess for inclusion the full text for any potentially relevant articles. Data will be extracted from the full text independently by two reviewers. Descriptive summary statistics will be presented for the extracted data. Discussion This systematic review will inform both researchers addressing CRXO methodology and trialists considering implementing the design. The results will allow focused methodological research of the CRXO design, provide practical examples for researchers of how CRXO trials have been conducted, including any shortcomings, and highlight areas where reporting and conduct may be improved. PMID:25115725

  1. Formulation of a methodology for power circuit design optimization

    NASA Technical Reports Server (NTRS)

    Yu, Y.; Bachmann, M.; Lee, F. C. Y.; Triner, J. E.

    1976-01-01

    A methodology for optimizing power-processor designs is described which achieves optimization with respect to some power-processor characteristic deemed particularly desirable by the designer, such as weight or efficiency. Optimization theory based on Lagrange multipliers is reviewed together with nonlinear programming techniques employing penalty functions. The methodology, the task of which is to minimize an objective function subject to design constraints, is demonstrated with the aid of four examples: optimum-weight core selection for an inductor with a predetermined winding size, optimum-weight inductor design with a given loss constraint, optimum-loss inductor design with a given weight constraint, and a comparison of optimum-weight single- and two-stage input-filter designs with identical loss and other requirement constraints. Closed-form solutions for the first three examples are obtained by applying the Lagrange-multiplier method, but solutions for the last example are found numerically through the use of the sequential unconstrained minimization technique.

  2. An integrated risk analysis methodology in a multidisciplinary design environment

    NASA Astrophysics Data System (ADS)

    Hampton, Katrina Renee

    Design of complex, one-of-a-kind systems, such as space transportation systems, is characterized by high uncertainty and, consequently, high risk. It is necessary to account for these uncertainties in the design process to produce systems that are more reliable. Systems designed by including uncertainties and managing them, as well, are more robust and less prone to poor operations as a result of parameter variability. The quantification, analysis and mitigation of uncertainties are challenging tasks as many systems lack historical data. In such an environment, risk or uncertainty quantification becomes subjective because input data is based on professional judgment. Additionally, there are uncertainties associated with the analysis tools and models. Both the input data and the model uncertainties must be considered for a multi disciplinary systems level risk analysis. This research synthesizes an integrated approach for developing a method for risk analysis. Expert judgment methodology is employed to quantify external risk. This methodology is then combined with a Latin Hypercube Sampling - Monte Carlo simulation to propagate uncertainties across a multidisciplinary environment for the overall system. Finally, a robust design strategy is employed to mitigate risk during the optimization process. This type of approach to risk analysis is conducive to the examination of quantitative risk factors. The core of this research methodology is the theoretical framework for uncertainty propagation. The research is divided into three stages or modules. The first two modules include the identification/quantification and propagation of uncertainties. The third module involves the management of uncertainties or response optimization. This final module also incorporates the integration of risk into program decision-making. The risk analysis methodology, is applied to a launch vehicle conceptual design study at NASA Langley Research Center. The launch vehicle multidisciplinary

  3. A methodological survey of the analysis, reporting and interpretation of Absolute Risk ReductiOn in systematic revieWs (ARROW): a study protocol

    PubMed Central

    2013-01-01

    Background Clinicians, providers and guideline panels use absolute effects to weigh the advantages and downsides of treatment alternatives. Relative measures have the potential to mislead readers. However, little is known about the reporting of absolute measures in systematic reviews. The objectives of our study are to determine the proportion of systematic reviews that report absolute measures of effect for the most important outcomes, and ascertain how they are analyzed, reported and interpreted. Methods/design We will conduct a methodological survey of systematic reviews published in 2010. We will conduct a 1:1 stratified random sampling of Cochrane vs. non-Cochrane systematic reviews. We will calculate the proportion of systematic reviews reporting at least one absolute estimate of effect for the most patient-important outcome for the comparison of interest. We will conduct multivariable logistic regression analyses with the reporting of an absolute estimate of effect as the dependent variable and pre-specified study characteristics as the independent variables. For systematic reviews reporting an absolute estimate of effect, we will document the methods used for the analysis, reporting and interpretation of the absolute estimate. Discussion Our methodological survey will inform current practices regarding reporting of absolute estimates in systematic reviews. Our findings may influence recommendations on reporting, conduct and interpretation of absolute estimates. Our results are likely to be of interest to systematic review authors, funding agencies, clinicians, guideline developers and journal editors. PMID:24330779

  4. Clinical trials in palliative care: a systematic review of their methodological characteristics and of the quality of their reporting.

    PubMed

    Bouça-Machado, Raquel; Rosário, Madalena; Alarcão, Joana; Correia-Guedes, Leonor; Abreu, Daisy; Ferreira, Joaquim J

    2017-01-25

    Over the past decades there has been a significant increase in the number of published clinical trials in palliative care. However, empirical evidence suggests that there are methodological problems in the design and conduct of studies, which raises questions about the validity and generalisability of the results and of the strength of the available evidence. We sought to evaluate the methodological characteristics and assess the quality of reporting of clinical trials in palliative care. We performed a systematic review of published clinical trials assessing therapeutic interventions in palliative care. Trials were identified using MEDLINE (from its inception to February 2015). We assessed methodological characteristics and describe the quality of reporting using the Cochrane Risk of Bias tool. We retrieved 107 studies. The most common medical field studied was oncology, and 43.9% of trials evaluated pharmacological interventions. Symptom control and physical dimensions (e.g. intervention on pain, breathlessness, nausea) were the palliative care-specific issues most studied. We found under-reporting of key information in particular on random sequence generation, allocation concealment, and blinding. While the number of clinical trials in palliative care has increased over time, methodological quality remains suboptimal. This compromises the quality of studies. Therefore, a greater effort is needed to enable the appropriate performance of future studies and increase the robustness of evidence-based medicine in this important field.

  5. Thin Film Heat Flux Sensors: Design and Methodology

    NASA Technical Reports Server (NTRS)

    Fralick, Gustave C.; Wrbanek, John D.

    2013-01-01

    Thin Film Heat Flux Sensors: Design and Methodology: (1) Heat flux is one of a number of parameters, together with pressure, temperature, flow, etc. of interest to engine designers and fluid dynamists, (2) The measurement of heat flux is of interest in directly determining the cooling requirements of hot section blades and vanes, and (3)In addition, if the surface and gas temperatures are known, the measurement of heat flux provides a value for the convective heat transfer coefficient that can be compared with the value provided by CFD codes.

  6. The landscape of systematic reviews in urology (1998 to 2015): an assessment of methodological quality.

    PubMed

    Han, Julia L; Gandhi, Shreyas; Bockoven, Crystal G; Narayan, Vikram M; Dahm, Philipp

    2017-04-01

    To assess the quality of published systematic reviews in the urology literature (an extension of our previously reported work), as high-quality systematic reviews play a paramount role in informing evidence-based clinical practice. Our focus was on systematic reviews in the urology literature that incorporated questions of prevention and therapy. To identify such reviews published during a 36-month period (2013-2015), we systematically searched PubMed and hand-searched the table of contents of four major urology journals. Two reviewers independently assessed the methodological quality of those reviews, using the 11-point 'Assessment of Multiple Systematic Reviews' (AMSTAR) instrument. We performed protocol-driven analyses of the data from our present study's 36-month period alone, as well as in aggregate with the data from our previously reported work's study periods (2009-2012 and 1998-2008). In our literature search of the 36-month period (2013-2015), we initially identified 490 possibly relevant reviews, of which 125 met our inclusion criteria. The most common topic of reviews for the 2013-2015 period was oncology (51.2%; n = 64), followed by voiding dysfunction (21.6%; n = 27). The mean [standard deviation (SD)] AMSTAR score in the 2013-2015 period (n = 125) was 4.8 (2.4); 2009-2012 (n = 113), 5.4 (2.3); and 1998-2008 (n = 57), 4.8 (2.0) (P = 0.127). In the 2013-2015 period, the mean (SD) AMSTAR score for the BJU International (n = 25) was 5.6 (2.9); for The Journal of Urology (n = 20), 5.1 (2.6); for European Urology (n = 60), 4.5 (2.2); and for Urology (n = 20), 4.4 (2.2) (P = 0.106). The number of systematic reviews published in the urology literature has exponentially increased, year by year, but their methodological quality has stagnated. To enhance the validity and impact of systematic reviews, all authors and editors must apply established methodological standards. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley

  7. When Playing Meets Learning: Methodological Framework for Designing Educational Games

    NASA Astrophysics Data System (ADS)

    Linek, Stephanie B.; Schwarz, Daniel; Bopp, Matthias; Albert, Dietrich

    Game-based learning builds upon the idea of using the motivational potential of video games in the educational context. Thus, the design of educational games has to address optimizing enjoyment as well as optimizing learning. Within the EC-project ELEKTRA a methodological framework for the conceptual design of educational games was developed. Thereby state-of-the-art psycho-pedagogical approaches were combined with insights of media-psychology as well as with best-practice game design. This science-based interdisciplinary approach was enriched by enclosed empirical research to answer open questions on educational game-design. Additionally, several evaluation-cycles were implemented to achieve further improvements. The psycho-pedagogical core of the methodology can be summarized by the ELEKTRA's 4Ms: Macroadaptivity, Microadaptivity, Metacognition, and Motivation. The conceptual framework is structured in eight phases which have several interconnections and feedback-cycles that enable a close interdisciplinary collaboration between game design, pedagogy, cognitive science and media psychology.

  8. Acceptance testing for PACS: from methodology to design to implementation

    NASA Astrophysics Data System (ADS)

    Liu, Brent J.; Huang, H. K.

    2004-04-01

    Acceptance Testing (AT) is a crucial step in the implementation process of a PACS within a clinical environment. AT determines whether the PACS is ready for clinical use and marks the official sign off of the PACS product. Most PACS vendors have Acceptance Testing (AT) plans, however, these plans do not provide a complete and robust evaluation of the full system. In addition, different sites will have different special requirements that vendor AT plans do not cover. The purpose of this paper is to introduce a protocol for AT design and present case studies of AT performed on clinical PACS. A methodology is presented that includes identifying testing components within PACS, quality assurance for both functionality and performance, and technical testing focusing on key single points-of-failure within the PACS product. Tools and resources that provide assistance in performing AT are discussed. In addition, implementation of the AT within the clinical environment and the overall implementation timeline of the PACS process are presented. Finally, case studies of actual AT of clinical PACS performed in the healthcare environment will be reviewed. The methodology for designing and implementing a robust AT plan for PACS was documented and has been used in PACS acceptance tests in several sites. This methodology can be applied to any PACS and can be used as a validation for the PACS product being acquired by radiology departments and hospitals. A methodology for AT design and implementation was presented that can be applied to future PACS installations. A robust AT plan for a PACS installation can increase both the utilization and satisfaction of a successful implementation of a PACS product that benefits both vendor and customer.

  9. Comparing EQ-5D valuation studies: a systematic review and methodological reporting checklist.

    PubMed

    Xie, Feng; Gaebel, Kathryn; Perampaladas, Kuhan; Doble, Brett; Pullenayegum, Eleanor

    2014-01-01

    There has been a growing interest around the world in developing country-specific scoring algorithms for the EQ-5D. This study systematically reviews all existing EQ-5D valuation studies to highlight their strengths and limitations, explores heterogeneity in observed utilities using meta-regression, and proposes a methodological checklist for reporting EQ-5D valuation studies. . We searched Medline, EMBASE, the National Health Service Economic Evaluation Database (NHS EED) via Wiley's Cochrane Library, and Wiley's Health Economic Evaluation Database from inception through November 2012, as well as bibliographies of key papers and the EuroQol Plenary Meeting Proceedings from 1991 to 2012 for English-language reports of EQ-5D valuation studies. Two reviewers independently screened the titles and abstracts for relevance. Three reviewers performed data extraction and compared the characteristics and scoring algorithms developed in the included valuation studies. . Of the 31 studies included in the review, 19 used the time trade-off (TTO) technique, 10 used the visual analogue scale (VAS) technique, and 2 used both TTO and VAS. Most studies included respondents from the general population selected by random or quota sampling and used face-to-face interviews or postal surveys. Studies valued between 7 and 198 total states, with 1-23 states valued per respondent. Different model specifications have been proposed for scoring. Some sample or demographic factors, including gender, education, percentage urban population, and national health care expenditure, were associated with differences in observed utilities for moderate or severe health states. . EQ-5D valuation studies conducted to date have varied widely in their design and in the resulting scoring algorithms. Therefore, we propose the Checklist for Reporting Valuation Studies of the EQ-5D (CREATE) for those conducting valuation studies.

  10. Changes in clinical trials methodology over time: a systematic review of six decades of research in psychopharmacology.

    PubMed

    Brunoni, André R; Tadini, Laura; Fregni, Felipe

    2010-03-03

    There have been many changes in clinical trials methodology since the introduction of lithium and the beginning of the modern era of psychopharmacology in 1949. The nature and importance of these changes have not been fully addressed to date. As methodological flaws in trials can lead to false-negative or false-positive results, the objective of our study was to evaluate the impact of methodological changes in psychopharmacology clinical research over the past 60 years. We performed a systematic review from 1949 to 2009 on MEDLINE and Web of Science electronic databases, and a hand search of high impact journals on studies of seven major drugs (chlorpromazine, clozapine, risperidone, lithium, fluoxetine and lamotrigine). All controlled studies published 100 months after the first trial were included. Ninety-one studies met our inclusion criteria. We analyzed the major changes in abstract reporting, study design, participants' assessment and enrollment, methodology and statistical analysis. Our results showed that the methodology of psychiatric clinical trials changed substantially, with quality gains in abstract reporting, results reporting, and statistical methodology. Recent trials use more informed consent, periods of washout, intention-to-treat approach and parametric tests. Placebo use remains high and unchanged over time. Clinical trial quality of psychopharmacological studies has changed significantly in most of the aspects we analyzed. There was significant improvement in quality reporting and internal validity. These changes have increased study efficiency; however, there is room for improvement in some aspects such as rating scales, diagnostic criteria and better trial reporting. Therefore, despite the advancements observed, there are still several areas that can be improved in psychopharmacology clinical trials.

  11. Instruments for assessing risk of bias and other methodological criteria of published animal studies: a systematic review.

    PubMed

    Krauth, David; Woodruff, Tracey J; Bero, Lisa

    2013-09-01

    Results from animal toxicology studies are critical to evaluating the potential harm from exposure to environmental chemicals or the safety of drugs prior to human testing. However, there is significant debate about how to evaluate the methodology and potential biases of the animal studies. There is no agreed-upon approach, and a systematic evaluation of current best practices is lacking. We performed a systematic review to identify and evaluate instruments for assessing the risk of bias and/or other methodological criteria of animal studies. We searched Medline (January 1966-November 2011) to identify all relevant articles. We extracted data on risk of bias criteria (e.g., randomization, blinding, allocation concealment) and other study design features included in each assessment instrument. Thirty distinct instruments were identified, with the total number of assessed risk of bias, methodological, and/or reporting criteria ranging from 2 to 25. The most common criteria assessed were randomization (25/30, 83%), investigator blinding (23/30, 77%), and sample size calculation (18/30, 60%). In general, authors failed to empirically justify why these or other criteria were included. Nearly all (28/30, 93%) of the instruments have not been rigorously tested for validity or reliability. Our review highlights a number of risk of bias assessment criteria that have been empirically tested for animal research, including randomization, concealment of allocation, blinding, and accounting for all animals. In addition, there is a need for empirically testing additional methodological criteria and assessing the validity and reliability of a standard risk of bias assessment instrument.

  12. Implementation of probabilistic design methodology at Tennessee State University

    NASA Technical Reports Server (NTRS)

    Onwubiko, Chinyere

    1995-01-01

    The fact that Deterministic Design Method no longer satisfies most design needs calls for methods that will cope with the high trend in technology. The advance in computer technology has reduced the rigors that normally accompany many design analysis methods that account for uncertainties in design parameters. Probabilistic Design Methodology (PDM) is beginning to make impact in engineering design. This method is gaining more recognition in industries than in educational institutions. Some of the reasons for the limited use of the PDM at the moment are that many are unaware of its potentials, and most of the software developed for PDM are very recent. The central goal of the PDM project at Tennessee State University is to introduce engineering students to this method. The students participating in the project learn about PDM and the computer codes that are available to the design engineer. The software being used for this project is NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) developed under NASA probabilistic structural analysis program. NESSUS has three different modules which make it a very comprehensive computer code for PDM. Since this method is new to the students, its introduction into the engineering curriculum is to be in stages. These range from the introduction of PDM and its software to the applications. While this program is being developed for its eventual inclusion into the engineering curriculum, some graduate and undergraduate students are already carrying out some projects using this method. As the students are increasing their understanding on PDM, they are at the same time applying it to some common design problems. The areas this method is being applied at the moment include, Design of Gears (spur and worm); Design of Brakes; Design of Heat Exchangers Design of Helical Springs; and Design of Shock Absorbers. Some of the current results of these projects are presented.

  13. Implementation of probabilistic design methodology at Tennessee State University

    NASA Technical Reports Server (NTRS)

    Onwubiko, Chinyere

    1995-01-01

    The fact that Deterministic Design Method no longer satisfies most design needs calls for methods that will cope with the high trend in technology. The advance in computer technology has reduced the rigors that normally accompany many design analysis methods that account for uncertainties in design parameters. Probabilistic Design Methodology (PDM) is beginning to make impact in engineering design. This method is gaining more recognition in industries than in educational institutions. Some of the reasons for the limited use of the PDM at the moment are that many are unaware of its potentials, and most of the software developed for PDM are very recent. The central goal of the PDM project at Tennessee State University is to introduce engineering students to this method. The students participating in the project learn about PDM and the computer codes that are available to the design engineer. The software being used for this project is NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) developed under NASA probabilistic structural analysis program. NESSUS has three different modules which make it a very comprehensive computer code for PDM. Since this method is new to the students, its introduction into the engineering curriculum is to be in stages. These range from the introduction of PDM and its software to the applications. While this program is being developed for its eventual inclusion into the engineering curriculum, some graduate and undergraduate students are already carrying out some projects using this method. As the students are increasing their understanding on PDM, they are at the same time applying it to some common design problems. The areas this method is being applied at the moment include, Design of Gears (spur and worm); Design of Brakes; Design of Heat Exchangers Design of Helical Springs; and Design of Shock Absorbers. Some of the current results of these projects are presented.

  14. The design and methodology of premature ejaculation interventional studies

    PubMed Central

    2016-01-01

    Large well-designed clinical efficacy and safety randomized clinical trials (RCTs) are required to achieve regulatory approval of new drug treatments. The objective of this article is to make recommendations for the criteria for defining and selecting the clinical trial study population, design and efficacy outcomes measures which comprise ideal premature ejaculation (PE) interventional trial methodology. Data on clinical trial design, epidemiology, definitions, dimensions and psychological impact of PE was reviewed, critiqued and incorporated into a series of recommendations for standardisation of PE clinical trial design, outcome measures and reporting using the principles of evidence based medicine. Data from PE interventional studies are only reliable, interpretable and capable of being generalised to patients with PE, when study populations are defined by the International Society for Sexual Medicine (ISSM) multivariate definition of PE. PE intervention trials should employ a double-blind RCT methodology and include placebo control, active standard drug control, and/or dose comparison trials. Ejaculatory latency time (ELT) and subject/partner outcome measures of control, personal/partner/relationship distress and other study-specific outcome measures should be used as outcome measures. There is currently no published literature which identifies a clinically significant threshold response to intervention. The ISSM definition of PE reflects the contemporary understanding of PE and represents the state-of-the-art multi-dimensional definition of PE and is recommended as the basis of diagnosis of PE for all PE clinical trials. PMID:27652224

  15. The design and methodology of premature ejaculation interventional studies.

    PubMed

    McMahon, Chris G

    2016-08-01

    Large well-designed clinical efficacy and safety randomized clinical trials (RCTs) are required to achieve regulatory approval of new drug treatments. The objective of this article is to make recommendations for the criteria for defining and selecting the clinical trial study population, design and efficacy outcomes measures which comprise ideal premature ejaculation (PE) interventional trial methodology. Data on clinical trial design, epidemiology, definitions, dimensions and psychological impact of PE was reviewed, critiqued and incorporated into a series of recommendations for standardisation of PE clinical trial design, outcome measures and reporting using the principles of evidence based medicine. Data from PE interventional studies are only reliable, interpretable and capable of being generalised to patients with PE, when study populations are defined by the International Society for Sexual Medicine (ISSM) multivariate definition of PE. PE intervention trials should employ a double-blind RCT methodology and include placebo control, active standard drug control, and/or dose comparison trials. Ejaculatory latency time (ELT) and subject/partner outcome measures of control, personal/partner/relationship distress and other study-specific outcome measures should be used as outcome measures. There is currently no published literature which identifies a clinically significant threshold response to intervention. The ISSM definition of PE reflects the contemporary understanding of PE and represents the state-of-the-art multi-dimensional definition of PE and is recommended as the basis of diagnosis of PE for all PE clinical trials.

  16. Fuel cell cathode air filters: Methodologies for design and optimization

    NASA Astrophysics Data System (ADS)

    Kennedy, Daniel M.; Cahela, Donald R.; Zhu, Wenhua H.; Westrom, Kenneth C.; Nelms, R. Mark; Tatarchuk, Bruce J.

    Proton exchange membrane (PEM) fuel cells experience performance degradation, such as reduction in efficiency and life, as a result of poisoning of platinum catalysts by airborne contaminants. Research on these contaminant effects suggests that the best possible solution to allowing fuel cells to operate in contaminated environments is by filtration of the harmful contaminants from the cathode air. A cathode air filter design methodology was created that connects properties of cathode air stream, filter design options, and filter footprint, to a set of adsorptive filter parameters that must be optimized to efficiently operate the fuel cell. Filter optimization requires a study of the trade off between two causal factors of power loss: first, a reduction in power production due to poisoning of the platinum catalyst by chemical contaminants and second, an increase in power requirements to operate the air compressor with a larger pressure drop from additional contaminant filtration. The design methodology was successfully applied to a 1.2 kW fuel cell using a programmable algorithm and predictions were made about the relationships between inlet concentration, breakthrough time, filter design, pressure drop, and compressor power requirements.

  17. Fast detection of manufacturing systematic design pattern failures causing device yield loss

    NASA Astrophysics Data System (ADS)

    Le Denmat, Jean-Christophe; Feldman, Nelly; Riewer, Olivia; Yesilada, Emek; Vallet, Michel; Suzor, Christophe; Talluto, Salvatore

    2015-03-01

    Starting from the 45nm technology node, systematic defectivity has a significant impact on device yield loss with each new technology node. The effort required to achieve patterning maturity with zero yield detractor is also significantly increasing with technology nodes. Within the manufacturing environment, new in-line wafer inspection methods have been developed to identify device systematic defects, including the process window qualification (PWQ) methodology used to characterize process robustness. Although patterning is characterized with PWQ methodology, some questions remain: How can we demonstrate that the measured process window is large enough to avoid design-based defects which will impact the device yield? Can we monitor the systematic yield loss on nominal wafers? From device test engineering point of view, systematic yield detractors are expected to be identified by Automated Test Pattern Generator (ATPG) test results diagnostics performed after electrical wafer sort (EWS). Test diagnostics can identify failed nets or cells causing systematic yield loss [1],[2]. Convergence from device failed nets and cells to failed manufacturing design pattern are usually based on assumptions that should be confirmed by an electrical failure analysis (EFA). However, many EFA investigations are required before the design pattern failures are found, and thus design pattern failure identification was costly in time and resources. With this situation, an opportunity to share knowledge exists between device test engineering and manufacturing environments to help with device yield improvement. This paper presents a new yield diagnostics flow dedicated to correlation of critical design patterns detected within manufacturing environment, with the observed device yield loss. The results obtained with this new flow on a 28nm technology device are described, with the defects of interest and the device yield impact for each design pattern. The EFA done to validate the design

  18. Behavioral headache research: methodologic considerations and research design alternatives.

    PubMed

    Hursey, Karl G; Rains, Jeanetta C; Penzien, Donald B; Nash, Justin M; Nicholson, Robert A

    2005-05-01

    Behavioral headache treatments have garnered solid empirical support in recent years, but there is substantial opportunity to strengthen the next generation of studies with improved methods and consistency across studies. Recently, Guidelines for Trials of Behavioral Treatments for Recurrent Headache were published to facilitate the production of high-quality research. The present article compliments the guidelines with a discussion of methodologic and research design considerations. Since there is no research design that is applicable in every situation, selecting an appropriate research design is fundamental to producing meaningful results. Investigators in behavioral headache and other areas of research consider the developmental phase of the research, the principle objectives of the project, and the sources of error or alternative interpretations in selecting a design. Phases of clinical trials typically include pilot studies, efficacy studies, and effectiveness studies. These trials may be categorized as primarily pragmatic or explanatory. The most appropriate research designs for these different phases and different objectives vary on such characteristics as sample size and assignment to condition, types of control conditions, periods or frequency of measurement, and the dimensions along which comparisons are made. A research design also must fit within constraints on available resources. There are a large number of potential research designs that can be used and considering these characteristics allows selection of appropriate research designs.

  19. [Methodological design of the National Health and Nutrition Survey 2016].

    PubMed

    Romero-Martínez, Martín; Shamah-Levy, Teresa; Cuevas-Nasu, Lucía; Gómez-Humarán, Ignacio Méndez; Gaona-Pineda, Elsa Berenice; Gómez-Acosta, Luz María; Rivera-Dommarco, Juan Ángel; Hernández-Ávila, Mauricio

    2017-01-01

    Describe the design methodology of the halfway health and nutrition national survey (Ensanut-MC) 2016. The Ensanut-MC is a national probabilistic survey whose objective population are the inhabitants of private households in Mexico. The sample size was determined to make inferences on the urban and rural areas in four regions. Describes main design elements: target population, topics of study, sampling procedure, measurement procedure and logistics organization. A final sample of 9 479 completed household interviews, and a sample of 16 591 individual interviews. The response rate for households was 77.9%, and the response rate for individuals was 91.9%. The Ensanut-MC probabilistic design allows valid statistical inferences about interest parameters for Mexico´s public health and nutrition, specifically on overweight, obesity and diabetes mellitus. Updated information also supports the monitoring, updating and formulation of new policies and priority programs.

  20. Applying a user centered design methodology in a clinical context.

    PubMed

    Kashfi, Hajar

    2010-01-01

    A clinical decision support system (CDSS) is an interactive application that is used to facilitate the process of decisionmaking in a clinical context. Developing a usable CDSS is a challenging process; mostly because of the complex nature of domain knowledge and the context of use of those systems. This paper describes how a user centered design (UCD) approach can be used in a clinical context for developing a CDSS. In our effort, a design-based research methodology has been used. The outcomes of this work are as follow; a customized UCD approach is suggested that combines UCD and openEHR. Moreover, the GUI developed in the design phase and the result of the GUI evaluation is briefly presented.

  1. Guidance on Conducting and REporting DElphi Studies (CREDES) in palliative care: Recommendations based on a methodological systematic review.

    PubMed

    Jünger, Saskia; Payne, Sheila A; Brine, Jenny; Radbruch, Lukas; Brearley, Sarah G

    2017-09-01

    The Delphi technique is widely used for the development of guidance in palliative care, having impact on decisions with relevance for patient care. To systematically examine the application of the Delphi technique for the development of best practice guidelines in palliative care. A methodological systematic review was undertaken using the databases PubMed, CINAHL, Web of Science, Academic Search Complete and EMBASE. Original articles (English language) were included when reporting on empirical studies that had used the Delphi technique to develop guidance for good clinical practice in palliative care. Data extraction included a quality appraisal on the rigour in conduct of the studies and the quality of reporting. A total of 30 empirical studies (1997-2015) were considered for full-text analysis. Considerable differences were identified regarding the rigour of the design and the reporting of essential process and outcome parameters. Furthermore, discrepancies regarding the use of terms for describing the method were observed, for example, concerning the understanding of a 'round' or a 'modified Delphi study'. Substantial variation was found concerning the quality of the study conduct and the transparency of reporting of Delphi studies used for the development of best practice guidance in palliative care. Since credibility of the resulting recommendations depends on the rigorous use of the Delphi technique, there is a need for consistency and quality both in the conduct and reporting of studies. To allow a critical appraisal of the methodology and the resulting guidance, a reporting standard for Conducting and REporting of DElphi Studies (CREDES) is proposed.

  2. Aircraft conceptual design - an adaptable parametric sizing methodology

    NASA Astrophysics Data System (ADS)

    Coleman, Gary John, Jr.

    Aerospace is a maturing industry with successful and refined baselines which work well for traditional baseline missions, markets and technologies. However, when new markets (space tourism) or new constrains (environmental) or new technologies (composite, natural laminar flow) emerge, the conventional solution is not necessarily best for the new situation. Which begs the question "how does a design team quickly screen and compare novel solutions to conventional solutions for new aerospace challenges?" The answer is rapid and flexible conceptual design Parametric Sizing. In the product design life-cycle, parametric sizing is the first step in screening the total vehicle in terms of mission, configuration and technology to quickly assess first order design and mission sensitivities. During this phase, various missions and technologies are assessed. During this phase, the designer is identifying design solutions of concepts and configurations to meet combinations of mission and technology. This research undertaking contributes the state-of-the-art in aircraft parametric sizing through (1) development of a dedicated conceptual design process and disciplinary methods library, (2) development of a novel and robust parametric sizing process based on 'best-practice' approaches found in the process and disciplinary methods library, and (3) application of the parametric sizing process to a variety of design missions (transonic, supersonic and hypersonic transports), different configurations (tail-aft, blended wing body, strut-braced wing, hypersonic blended bodies, etc.), and different technologies (composite, natural laminar flow, thrust vectored control, etc.), in order to demonstrate the robustness of the methodology and unearth first-order design sensitivities to current and future aerospace design problems. This research undertaking demonstrates the importance of this early design step in selecting the correct combination of mission, technologies and configuration to

  3. Design methodology for multilayer microwave filters and Balun circuits

    NASA Astrophysics Data System (ADS)

    Cho, Choonsik

    A systematic and efficient approach to the design for a broad class of passive microwave circuits in multilayer configurations is presented. Multilayer configurations are becoming popular at microwave frequencies due to their several advantages over single layer configurations. However, systematic design procedures for multilayer circuits have not been yet available. Design procedures for several types of microwave circuits in multilayer configurations have been developed. Parallel coupled-line band-pass filters, end-coupled bandpass filters and three-line baluns have been designed with the systematic design procedures developed. Procedures developed have been verified by comparing the results with full-wave electromagnetic simulations. These circuits have also been fabricated and measured to verify the design procedures. Wide bandwidth, size/volume compaction, flexible design and physically realizable dimensions are the factors that multilayer structures provide compared to single layer configurations. A network modeling is employed to characterize multilayer multi-conductor transmission line systems. Since the microwave circuits developed utilize multiple coupled lines in multilayer configurations, the characterization of these coupled lines plays a significant role in derivation of design equations and generation of design procedures. Using this modeling approach, a multiple coupled line system can be transformed to a multiple uncoupled line system. These equivalent uncoupled lines are used to derive network parameters ([S], [Y] or [Z] matrix) for coupled lines. The normal mode parameters (NMPs) for coupled lines derived in terms of system specifications are utilized to obtain the physical geometries. An optimization process is employed to find the geometries which yield the desired NMPs calculated from circuit specifications. For optimizing the geometry, a quasi-static field analysis program, Segmentation and Boundary Element Method (SBEM), is employed to

  4. Development and implementation of rotorcraft preliminary design methodology using multidisciplinary design optimization

    NASA Astrophysics Data System (ADS)

    Khalid, Adeel Syed

    Rotorcraft's evolution has lagged behind that of fixed-wing aircraft. One of the reasons for this gap is the absence of a formal methodology to accomplish a complete conceptual and preliminary design. Traditional rotorcraft methodologies are not only time consuming and expensive but also yield sub-optimal designs. Rotorcraft design is an excellent example of a multidisciplinary complex environment where several interdependent disciplines are involved. A formal framework is developed and implemented in this research for preliminary rotorcraft design using IPPD methodology. The design methodology consists of the product and process development cycles. In the product development loop, all the technical aspects of design are considered including the vehicle engineering, dynamic analysis, stability and control, aerodynamic performance, propulsion, transmission design, weight and balance, noise analysis and economic analysis. The design loop starts with a detailed analysis of requirements. A baseline is selected and upgrade targets are identified depending on the mission requirements. An Overall Evaluation Criterion (OEC) is developed that is used to measure the goodness of the design or to compare the design with competitors. The requirements analysis and baseline upgrade targets lead to the initial sizing and performance estimation of the new design. The digital information is then passed to disciplinary experts. This is where the detailed disciplinary analyses are performed. Information is transferred from one discipline to another as the design loop is iterated. To coordinate all the disciplines in the product development cycle, Multidisciplinary Design Optimization (MDO) techniques e.g. All At Once (AAO) and Collaborative Optimization (CO) are suggested. The methodology is implemented on a Light Turbine Training Helicopter (LTTH) design. Detailed disciplinary analyses are integrated through a common platform for efficient and centralized transfer of design

  5. The use of Lean and Six Sigma methodologies in surgery: a systematic review.

    PubMed

    Mason, S E; Nicolay, C R; Darzi, A

    2015-04-01

    Lean and Six Sigma are improvement methodologies developed in the manufacturing industry and have been applied to healthcare settings since the 1990 s. They use a systematic and reproducible approach to provide Quality Improvement (QI), with a flexible process that can be applied to a range of outcomes across different patient groups. This review assesses the literature with regard to the use and utility of Lean and Six Sigma methodologies in surgery. MEDLINE, Embase, PsycINFO, Allied and Complementary Medicine Database, British Nursing Index, Cumulative Index to Nursing and Allied Health Literature, Health Business Elite and the Health Management Information Consortium were searched in January 2014. Experimental studies were included if they assessed the use of Lean or Six Sigma on the ability to improve specified outcomes in surgical patients. Of the 124 studies returned, 23 were suitable for inclusion with 11 assessing Lean, 6 Six Sigma and 6 Lean Six Sigma. The broad range of outcomes can be collated into six common aims: to optimise outpatient efficiency, to improve operating theatre efficiency, to decrease operative complications, to reduce ward-based harms, to reduce mortality and to limit unnecessary cost and length of stay. The majority of studies (88%) demonstrate improvement; however high levels of systematic bias and imprecision were evident. Lean and Six Sigma QI methodologies have the potential to produce clinically significant improvement for surgical patients. However there is a need to conduct high-quality studies with low risk of systematic bias in order to further understand their role. Copyright © 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  6. External validation of multivariable prediction models: a systematic review of methodological conduct and reporting

    PubMed Central

    2014-01-01

    Background Before considering whether to use a multivariable (diagnostic or prognostic) prediction model, it is essential that its performance be evaluated in data that were not used to develop the model (referred to as external validation). We critically appraised the methodological conduct and reporting of external validation studies of multivariable prediction models. Methods We conducted a systematic review of articles describing some form of external validation of one or more multivariable prediction models indexed in PubMed core clinical journals published in 2010. Study data were extracted in duplicate on design, sample size, handling of missing data, reference to the original study developing the prediction models and predictive performance measures. Results 11,826 articles were identified and 78 were included for full review, which described the evaluation of 120 prediction models. in participant data that were not used to develop the model. Thirty-three articles described both the development of a prediction model and an evaluation of its performance on a separate dataset, and 45 articles described only the evaluation of an existing published prediction model on another dataset. Fifty-seven percent of the prediction models were presented and evaluated as simplified scoring systems. Sixteen percent of articles failed to report the number of outcome events in the validation datasets. Fifty-four percent of studies made no explicit mention of missing data. Sixty-seven percent did not report evaluating model calibration whilst most studies evaluated model discrimination. It was often unclear whether the reported performance measures were for the full regression model or for the simplified models. Conclusions The vast majority of studies describing some form of external validation of a multivariable prediction model were poorly reported with key details frequently not presented. The validation studies were characterised by poor design, inappropriate handling

  7. Systematic and progressive implementation of the centers of excellence for rheumatoid arthritis: a methodological proposal.

    PubMed

    Santos-Moreno, Pedro; Caballero-Uribe, Carlo V; Massardo, Maria Loreto; Maldonado, Claudio Galarza; Soriano, Enrique R; Pineda, Carlos; Cardiel, Mario; Benavides, Juan Alberto; Beltrán, Paula Andrea

    2017-08-24

    The implementation of excellence centers in specific diseases has been gaining recognition in the field of health; specifically in rheumatoid arthritis, where the prognosis of the disease is related to an early diagnosis and a timely intervention, it is necessary that the provision of health services is developed in an environment of quality, opportunity, and safety with the highest standards of care. A methodology that allows this implementation in such a way that is achievable by the most of the care centers is a priority to achieve a better attention to populations with this disease. In this paper, we propose a systematic and progressive methodology that will help all the institutions to develop successful models without faltering in the process. The expected impact on public health is defined by a better effective coverage of high-quality treatments, obtaining better health outcomes with safety and accessibility that reduces the budgetary impact for the health systems of our countries.

  8. EuroSkyWay Multipurpose Terminal: architecture and design methodology

    NASA Astrophysics Data System (ADS)

    Ciancarelli, C.; Macchia, G.

    2002-07-01

    This paper describes the architecture of the EuroSkyWay Multipurpose Terminal, aimed to satisfy the need of the Provider and Gateway Terminal of the EuroSkyWay system. First, an overview of the EuroSkyWay system is shown, with a short description of the proprietary EuroSkyWay protocol layer and of the terminals. The extension of the OMT methodology that has been used to design the system is described. Then, the architecture of the Multipurpose Terminal described in terms of configurations, hardware and software.

  9. Application of concept selection methodology in IC process design

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Kul

    1993-01-01

    Search for an effective methodology practical in IC manufacturing process development led to trial of quantitative 'concept selection' methodology in selecting the 'best' alternative for interlevel dielectric (ILD) processes. A cross-functional team selected multi-criteria with scoring guidelines to be used in the definition of the 'best'. The project was targeted for the 3 level metal backend process for sub-micron gate array product. The outcome of the project showed that the maturity of the alternatives has strong influence on the scores, because scores on the adopted criteria such as yield, reliability and maturity will depend on the maturity of a particular process. At the same time, the project took longer than expected since it required data for the multiple criteria. These observations suggest that adopting a simpler procedure that can analyze total inherent controllability of a process would be more effective. The methodology of the DFS (design for simplicity) tools used in analyzing the manufacturability of such electronics products as computers, phones and other consumer electronics products could be used as an 'analogy' in constructing an evaluation method for IC processes that produce devices used in those electronics products. This could be done by focusing on the basic process operation elements rather than the layers that are being built.

  10. Design methodology of microstructures for enhanced mechanical reliability

    NASA Astrophysics Data System (ADS)

    Wittler, Olaf; Walter, Hans; Vogel, Dietmar; Keller, Juergen; Michel, Bernd

    2005-04-01

    The achievement of reliability is a major task during the design process of microsystems (i.e. MEMS: mechanical-electrical microsystems). In this respect CAD (computer aided design) simulation methods play a major role in the dimensioning of mechanical structures. It can be observed that a pure CAD approach becomes difficult because of the complexity of these systems, which originates from the large variety of integrated materials and thus a diversity of the resulting failure mechanisms. Therefore strategies dealing with these uncertainties in reliability estimates need to be incorporated in the design process. The approach presented in this paper is based on the application of simulation and advanced deformation measurement methods named microDAC (micro deformation analysis by means of grey scale correlation) and nanoDAC. It is exemplified on different detail levels of the reliability assessment, with an emphasis on fracture. The first stage consists of a parametric simulation approach, which helps to develop design guidelines for the geometry. For a more absolute quantitative analysis and for material selection in a new design the mechanical properties need to be specified and evaluated with respect to reliability. Besides, the described systematics of reliability assessment needs a profound knowledge of the failure behavior, which is analyzed by the application of microDAC/nanoDAC techniques. In the prescribed way, it becomes possible to tackle mechanical reliability problems in early design phases.

  11. Guidance for updating clinical practice guidelines: a systematic review of methodological handbooks

    PubMed Central

    2014-01-01

    Background Updating clinical practice guidelines (CPGs) is a crucial process for maintaining the validity of recommendations. Methodological handbooks should provide guidance on both developing and updating CPGs. However, little is known about the updating guidance provided by these handbooks. Methods We conducted a systematic review to identify and describe the updating guidance provided by CPG methodological handbooks and included handbooks that provide updating guidance for CPGs. We searched in the Guidelines International Network library, US National Guidelines Clearinghouse and MEDLINE (PubMed) from 1966 to September 2013. Two authors independently selected the handbooks and extracted the data. We used descriptive statistics to analyze the extracted data and conducted a narrative synthesis. Results We included 35 handbooks. Most handbooks (97.1%) focus mainly on developing CPGs, including variable degrees of information about updating. Guidance on identifying new evidence and the methodology of assessing the need for an update is described in 11 (31.4%) and eight handbooks (22.8%), respectively. The period of time between two updates is described in 25 handbooks (71.4%), two to three years being the most frequent (40.0%). The majority of handbooks do not provide guidance for the literature search, evidence selection, assessment, synthesis, and external review of the updating process. Conclusions Guidance for updating CPGs is poorly described in methodological handbooks. This guidance should be more rigorous and explicit. This could lead to a more optimal updating process, and, ultimately to valid trustworthy guidelines. PMID:24383701

  12. Guidance for updating clinical practice guidelines: a systematic review of methodological handbooks.

    PubMed

    Vernooij, Robin W M; Sanabria, Andrea Juliana; Solà, Ivan; Alonso-Coello, Pablo; Martínez García, Laura

    2014-01-02

    Updating clinical practice guidelines (CPGs) is a crucial process for maintaining the validity of recommendations. Methodological handbooks should provide guidance on both developing and updating CPGs. However, little is known about the updating guidance provided by these handbooks. We conducted a systematic review to identify and describe the updating guidance provided by CPG methodological handbooks and included handbooks that provide updating guidance for CPGs. We searched in the Guidelines International Network library, US National Guidelines Clearinghouse and MEDLINE (PubMed) from 1966 to September 2013. Two authors independently selected the handbooks and extracted the data. We used descriptive statistics to analyze the extracted data and conducted a narrative synthesis. We included 35 handbooks. Most handbooks (97.1%) focus mainly on developing CPGs, including variable degrees of information about updating. Guidance on identifying new evidence and the methodology of assessing the need for an update is described in 11 (31.4%) and eight handbooks (22.8%), respectively. The period of time between two updates is described in 25 handbooks (71.4%), two to three years being the most frequent (40.0%). The majority of handbooks do not provide guidance for the literature search, evidence selection, assessment, synthesis, and external review of the updating process. Guidance for updating CPGs is poorly described in methodological handbooks. This guidance should be more rigorous and explicit. This could lead to a more optimal updating process, and, ultimately to valid trustworthy guidelines.

  13. Methodological considerations in cost of prostate cancer studies: a systematic review.

    PubMed

    Molinier, Laurent; Bauvin, Eric; Combescure, Christophe; Castelli, Christel; Rebillard, Xavier; Soulié, Michel; Daurès, Jean-Pierre; Grosclaude, Pascale

    2008-01-01

    Cost-of-illness (COI) studies estimate the overall economic burden of a specific disease, rather than simply treatment-related costs. While having been criticized for not allowing resource prioritization, COI studies can provide useful guidance, so long as they adhere to accepted methodology. Prostate cancer is an important disease in terms of economic implications because of its increasing incidence and health-care costs and therefore provides a relevant example with which to review COI study methodologies. The aim of this study was to review published COI studies on prostate cancer to analyze the methods used. First, we provide a general description of the COI method. COI studies relating to prostate cancer were then systematically reviewed, focussing on an analysis of the different methods used. The methods, data sources, and estimated cost categories in each study varied widely. The review showed that COI studies adopted significantly different approaches to estimate the costs of prostate cancer, reflecting a lack of consensus on the methodology of COI studies in this area. To increase its credibility, closer agreement among researchers on the methodological principles of the COI studies would be desirable.

  14. Systematic Review of the Application of Lean and Six Sigma Quality Improvement Methodologies in Radiology.

    PubMed

    Amaratunga, Thelina; Dobranowski, Julian

    2016-09-01

    Preventable yet clinically significant rates of medical error remain systemic, while health care spending is at a historic high. Industry-based quality improvement (QI) methodologies show potential for utility in health care and radiology because they use an empirical approach to reduce variability and improve workflow. The aim of this review was to systematically assess the literature with regard to the use and efficacy of Lean and Six Sigma (the most popular of the industrial QI methodologies) within radiology. MEDLINE, the Allied & Complementary Medicine Database, Embase Classic + Embase, Health and Psychosocial Instruments, and the Ovid HealthStar database, alongside the Cochrane Library databases, were searched on June 2015. Empirical studies in peer-reviewed journals were included if they assessed the use of Lean, Six Sigma, or Lean Six Sigma with regard to their ability to improve a variety of quality metrics in a radiology-centered clinical setting. Of the 278 articles returned, 23 studies were suitable for inclusion. Of these, 10 assessed Six Sigma, 7 assessed Lean, and 6 assessed Lean Six Sigma. The diverse range of measured outcomes can be organized into 7 common aims: cost savings, reducing appointment wait time, reducing in-department wait time, increasing patient volume, reducing cycle time, reducing defects, and increasing staff and patient safety and satisfaction. All of the included studies demonstrated improvements across a variety of outcomes. However, there were high rates of systematic bias and imprecision as per the Grading of Recommendations Assessment, Development and Evaluation guidelines. Lean and Six Sigma QI methodologies have the potential to reduce error and costs and improve quality within radiology. However, there is a pressing need to conduct high-quality studies in order to realize the true potential of these QI methodologies in health care and radiology. Recommendations on how to improve the quality of the literature are proposed

  15. Systematic review of the application of quality improvement methodologies from the manufacturing industry to surgical healthcare.

    PubMed

    Nicolay, C R; Purkayastha, S; Greenhalgh, A; Benn, J; Chaturvedi, S; Phillips, N; Darzi, A

    2012-03-01

    The demand for the highest-quality patient care coupled with pressure on funding has led to the increasing use of quality improvement (QI) methodologies from the manufacturing industry. The aim of this systematic review was to identify and evaluate the application and effectiveness of these QI methodologies to the field of surgery. MEDLINE, the Cochrane Database, Allied and Complementary Medicine Database, British Nursing Index, Cumulative Index to Nursing and Allied Health Literature, Embase, Health Business(™) Elite, the Health Management Information Consortium and PsycINFO(®) were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Empirical studies were included that implemented a described QI methodology to surgical care and analysed a named outcome statistically. Some 34 of 1595 articles identified met the inclusion criteria after consensus from two independent investigators. Nine studies described continuous quality improvement (CQI), five Six Sigma, five total quality management (TQM), five plan-do-study-act (PDSA) or plan-do-check-act (PDCA) cycles, five statistical process control (SPC) or statistical quality control (SQC), four Lean and one Lean Six Sigma; 20 of the studies were undertaken in the USA. The most common aims were to reduce complications or improve outcomes (11), to reduce infection (7), and to reduce theatre delays (7). There was one randomized controlled trial. QI methodologies from industry can have significant effects on improving surgical care, from reducing infection rates to increasing operating room efficiency. The evidence is generally of suboptimal quality, and rigorous randomized multicentre studies are needed to bring evidence-based management into the same league as evidence-based medicine. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  16. Impact of rehabilitation on self-concept following traumatic brain injury: An exploratory systematic review of intervention methodology and efficacy.

    PubMed

    Ownsworth, Tamara; Haslam, Catherine

    2016-01-01

    To date, reviews of rehabilitation efficacy after traumatic brain injury (TBI) have overlooked the impact on sense of self, focusing instead on functional impairment and psychological distress. The present review sought to address this gap by critically appraising the methodology and efficacy of intervention studies that assess changes in self-concept. A systematic search of PsycINFO, Medline, CINAHL and PubMed was conducted from inception to September 2013 to identify studies reporting pre- and post-intervention changes on validated measures of self-esteem or self-concept in adults with TBI. Methodological quality of randomised controlled trials (RCTs) was examined using the Physiotherapy Evidence Database (PEDro) scale. A total of 17 studies (10 RCTs, 4 non-RCT group studies, 3 case studies) was identified, which examined the impact of psychotherapy, family-based support, cognitive rehabilitation or activity-based interventions on self-concept. The findings on the efficacy of these interventions were mixed, with only 10 studies showing some evidence of improvement in self-concept based on within-group or pre-post comparisons. Such findings highlight the need for greater focus on the impact of rehabilitation on self-understanding with improved assessment and intervention methodology. We draw upon theories of identity reconstruction and highlight implications for the design and evaluation of identity-oriented interventions that can supplement existing rehabilitation programmes for people with TBI.

  17. Developing an evidence-based methodological framework to systematically compare HTA coverage decisions: A mixed methods study.

    PubMed

    Nicod, Elena; Kanavos, Panos

    2016-01-01

    Health Technology Assessment (HTA) often results in different coverage recommendations across countries for a same medicine despite similar methodological approaches. This paper develops and pilots a methodological framework that systematically identifies the reasons for these differences using an exploratory sequential mixed methods research design. The study countries were England, Scotland, Sweden and France. The methodological framework was built around three stages of the HTA process: (a) evidence, (b) its interpretation, and (c) its influence on the final recommendation; and was applied to two orphan medicinal products. The criteria accounted for at each stage were qualitatively analyzed through thematic analysis. Piloting the framework for two medicines, eight trials, 43 clinical endpoints and seven economic models were coded 155 times. Eighteen different uncertainties about this evidence were coded 28 times, 56% of which pertained to evidence commonly appraised and 44% to evidence considered by only some agencies. The poor agreement in interpreting this evidence (κ=0.183) was partly explained by stakeholder input (ns=48 times), or by agency-specific risk (nu=28 uncertainties) and value preferences (noc=62 "other considerations"), derived through correspondence analysis. Accounting for variability at each stage of the process can be achieved by codifying its existence and quantifying its impact through the application of this framework. The transferability of this framework to other disease areas, medicines and countries is ensured by its iterative and flexible nature, and detailed description.

  18. 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.

  19. Design Evolution and Methodology for Pumpkin Super-Pressure Balloons

    NASA Astrophysics Data System (ADS)

    Farley, Rodger

    The NASA Ultra Long Duration Balloon (ULDB) program has had many technical development issues discovered and solved along its road to success as a new vehicle. It has the promise of being a sub-satellite, a means to launch up to 2700 kg to 33.5 km altitude for 100 days from a comfortable mid-latitude launch point. Current high-lift long duration ballooning is accomplished out of Antarctica with zero-pressure balloons, which cannot cope with the rigors of diurnal cycles. The ULDB design is still evolving, the product of intense analytical effort, scaled testing, improved manufacturing, and engineering intuition. The past technical problems, in particular the s-cleft deformation, their solutions, future challenges, and the methodology of pumpkin balloon design will generally be described.

  20. Fast underdetermined BSS architecture design methodology for real time applications.

    PubMed

    Mopuri, Suresh; Reddy, P Sreenivasa; Acharyya, Amit; Naik, Ganesh R

    2015-01-01

    In this paper, we propose a high speed architecture design methodology for the Under-determined Blind Source Separation (UBSS) algorithm using our recently proposed high speed Discrete Hilbert Transform (DHT) targeting real time applications. In UBSS algorithm, unlike the typical BSS, the number of sensors are less than the number of the sources, which is of more interest in the real time applications. The DHT architecture has been implemented based on sub matrix multiplication method to compute M point DHT, which uses N point architecture recursively and where M is an integer multiples of N. The DHT architecture and state of the art architecture are coded in VHDL for 16 bit word length and ASIC implementation is carried out using UMC 90 - nm technology @V DD = 1V and @ 1MHZ clock frequency. The proposed architecture implementation and experimental comparison results show that the DHT design is two times faster than state of the art architecture.

  1. A methodology for double patterning compliant split and design

    NASA Astrophysics Data System (ADS)

    Wiaux, Vincent; Verhaegen, Staf; Iwamoto, Fumio; Maenhoudt, Mireille; Matsuda, Takashi; Postnikov, Sergei; Vandenberghe, Geert

    2008-11-01

    Double Patterning allows to further extend the use of water immersion lithography at its maximum numerical aperture NA=1.35. Splitting of design layers to recombine through Double Patterning (DP) enables an effective resolution enhancement. Single polygons may need to be split up (cut) depending on the pattern density and its 2D content. The split polygons recombine at the so-called 'stitching points'. These stitching points may affect the yield due to the sensitivity to process variations. We describe a methodology to ensure a robust double patterning by identifying proper split- and design- guidelines. Using simulations and experimental data, we discuss in particular metal1 first interconnect layers of random LOGIC and DRAM applications at 45nm half-pitch (hp) and 32nm hp where DP may become the only timely patterning solution.

  2. A systematic review of the methodological quality and outcomes of RCTs to teach medical undergraduates surgical and emergency procedures.

    PubMed

    Thomas, Roger E; Crutcher, Rodney; Lorenzetti, Diane

    2007-08-01

    There is no systematic review of the methodological quality of randomized controlled trials (RCTs) of teaching surgical and emergency skills to undergraduates. We searched the Cochrane Collaboration Controlled Trials Register, the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, ERIC, DARE and the University of Toronto Continuing Medical Education database for RCTs in all languages. We identified 19 RCTs. Four tested methods of IV access, 1 found intraosseous access faster than the umbilical vein in neonates, and 1 found that one type of intraosseous needle had higher success rates. Two RCTs of intubation skills did not identify a superior technique. One RCT of CPR found video instruction superior to the American Heart Association Heartsaver course. Of 2 RCTs of trauma skills, 1 found no improvement and 1 found improvement only on the day of instruction. One RCT found both computer and seminar training improved epistaxis management. One RCT gave students preoperative anatomy instruction, and they received higher ratings from surgeons. One RCT asked students to study surgical scenarios preoperatively, and they improved their surgical intensive care unit skills. One RCT gave students video and paper-cut instruction of the Whipple procedure; both groups improved, but there were no differences between groups. One RCT taught uteteroscopy and stone extraction and found groups that used low- and high-fidelity bench models improved, compared with the didactic group. Four of 5 RCTs of knot tying showed improvement. This systematic review assessed the quality of RCTs used in teaching undergraduates surgical and emergency skills. There are many positive study outcomes, but there are significant methodological weaknesses in the study design. Students varied in their skills, and most did not demonstrate optimal performance in any of the procedures. This review provides a baseline for further work important to both medical education and clinical practice.

  3. A systematic review of the methodological quality and outcomes of RCTs to teach medical undergraduates surgical and emergency procedures

    PubMed Central

    Thomas, Roger E.; Crutcher, Rodney; Lorenzetti, Diane

    2007-01-01

    Background There is no systematic review of the methodological quality of randomized controlled trials (RCTs) of teaching surgical and emergency skills to undergraduates. Methods We searched the Cochrane Collaboration Controlled Trials Register, the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, ERIC, DARE and the University of Toronto Continuing Medical Education database for RCTs in all languages. Results We identified 19 RCTs. Four tested methods of IV access, 1 found intraosseous access faster than the umbilical vein in neonates, and 1 found that one type of intraosseous needle had higher success rates. Two RCTs of intubation skills did not identify a superior technique. One RCT of CPR found video instruction superior to the American Heart Association Heartsaver course. Of 2 RCTs of trauma skills, 1 found no improvement and 1 found improvement only on the day of instruction. One RCT found both computer and seminar training improved epistaxis management. One RCT gave students preoperative anatomy instruction, and they received higher ratings from surgeons. One RCT asked students to study surgical scenarios preoperatively, and they improved their surgical intensive care unit skills. One RCT gave students video and paper-cut instruction of the Whipple procedure; both groups improved, but there were no differences between groups. One RCT taught uteteroscopy and stone extraction and found groups that used low-and high-fidelity bench models improved, compared with the didactic group. Four of 5 RCTs of knot tying showed improvement. Conclusions This systematic review assessed the quality of RCTs used in teaching undergraduates surgical and emergency skills. There are many positive study outcomes, but there are significant methodological weaknesses in the study design. Students varied in their skills, and most did not demonstrate optimal performance in any of the procedures. This review provides a baseline for further work important to both medical education

  4. A variable-gain output feedback control design methodology

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim; Moerder, Daniel D.; Broussard, John R.; Taylor, Deborah B.

    1989-01-01

    A digital control system design technique is developed in which the control system gain matrix varies with the plant operating point parameters. The design technique is obtained by formulating the problem as an optimal stochastic output feedback control law with variable gains. This approach provides a control theory framework within which the operating range of a control law can be significantly extended. Furthermore, the approach avoids the major shortcomings of the conventional gain-scheduling techniques. The optimal variable gain output feedback control problem is solved by embedding the Multi-Configuration Control (MCC) problem, previously solved at ICS. An algorithm to compute the optimal variable gain output feedback control gain matrices is developed. The algorithm is a modified version of the MCC algorithm improved so as to handle the large dimensionality which arises particularly in variable-gain control problems. The design methodology developed is applied to a reconfigurable aircraft control problem. A variable-gain output feedback control problem was formulated to design a flight control law for an AFTI F-16 aircraft which can automatically reconfigure its control strategy to accommodate failures in the horizontal tail control surface. Simulations of the closed-loop reconfigurable system show that the approach produces a control design which can accommodate such failures with relative ease. The technique can be applied to many other problems including sensor failure accommodation, mode switching control laws and super agility.

  5. A symbolic methodology to improve disassembly process design.

    PubMed

    Rios, Pedro; Blyler, Leslie; Tieman, Lisa; Stuart, Julie Ann; Grant, Ed

    2003-12-01

    Millions of end-of-life electronic components are retired annually due to the proliferation of new models and their rapid obsolescence. The recovery of resources such as plastics from these goods requires their disassembly. The time required for each disassembly and its associated cost is defined by the operator's familiarity with the product design and its complexity. Since model proliferation serves to complicate an operator's learning curve, it is worthwhile to investigate the benefits to be gained in a disassembly operator's preplanning process. Effective disassembly process design demands the application of green engineering principles, such as those developed by Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37, 94A-101A), which include regard for product complexity, structural commonality, separation energy, material value, and waste prevention. This paper introduces the concept of design symbolsto help the operator more efficiently survey product complexity with respect to location and number of fasteners to remove a structure that is common to all electronics: the housing. With a sample of 71 different computers, printers, and monitors, we demonstrate that appropriate symbols reduce the total disassembly planning time by 13.2 min. Such an improvement could well make efficient the separation of plastic that would otherwise be destined for waste-to-energy or landfill. The symbolic methodology presented may also improve Design for Recycling and Design for Maintenance and Support.

  6. SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation of multiple objectives is very important in designing environmentally benign processes. It requires a systematic procedure for solving multiobjective decision-making problems, due to the complex nature of the problems, the need for complex assessments, and complicated ...

  7. SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation of multiple objectives is very important in designing environmentally benign processes. It requires a systematic procedure for solving multiobjective decision-making problems, due to the complex nature of the problems, the need for complex assessments, and complicated ...

  8. A Practical Methodology for Quantifying Random and Systematic Components of Unexplained Variance in a Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Deloach, Richard; Obara, Clifford J.; Goodman, Wesley L.

    2012-01-01

    This paper documents a check standard wind tunnel test conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3M TCT) that was designed and analyzed using the Modern Design of Experiments (MDOE). The test designed to partition the unexplained variance of typical wind tunnel data samples into two constituent components, one attributable to ordinary random error, and one attributable to systematic error induced by covariate effects. Covariate effects in wind tunnel testing are discussed, with examples. The impact of systematic (non-random) unexplained variance on the statistical independence of sequential measurements is reviewed. The corresponding correlation among experimental errors is discussed, as is the impact of such correlation on experimental results generally. The specific experiment documented herein was organized as a formal test for the presence of unexplained variance in representative samples of wind tunnel data, in order to quantify the frequency with which such systematic error was detected, and its magnitude relative to ordinary random error. Levels of systematic and random error reported here are representative of those quantified in other facilities, as cited in the references.

  9. Systematic review of foodborne burden of disease studies: quality assessment of data and methodology.

    PubMed

    Haagsma, Juanita A; Polinder, Suzanne; Stein, Claudia E; Havelaar, Arie H

    2013-08-16

    Burden of disease (BoD) studies aim to identify the public health impact of different health problems and risk factors. To assess BoD, detailed knowledge is needed on epidemiology, disability and mortality in the population under study. This is particularly challenging for foodborne disease, because of the multitude of causative agents and their health effects. The purpose of this study is to systematically review the methodology of foodborne BoD studies. Three key questions were addressed: 1) which data sources and approaches were used to assess mortality, morbidity and disability?, 2) which methodological choices were made to calculate Disability Adjusted Life Years (DALY), and 3) were uncertainty analyses performed and if so, how? Studies (1990-June 2012) in international peer-reviewed journals and grey literature were identified with main inclusion criteria being that the study assessed disability adjusted life years related to foodborne disease. Twenty-four studies met our inclusion criteria. To assess incidence or prevalence of foodborne disease in the population, four approaches could be distinguished, each using a different data source as a starting point, namely 1) laboratory-confirmed cases, 2) cohort or cross-sectional data, 3) syndrome surveillance data and 4) exposure data. Considerable variation existed in BoD methodology (e.g. disability weights, discounting, age-weighting). Almost all studies analyzed the effect of uncertainty as a result of possible imprecision in the parameter values. Awareness of epidemiological and methodological rigor between foodborne BoD studies using the DALY approach is a critical priority for advancing burden of disease studies. Harmonization of methodology that is used and of modeling techniques and high quality data can enlarge the detection of real variation in DALY outcomes between pathogens, between populations or over time. This harmonization can be achieved by identifying substantial data gaps and uncertainty and

  10. Integrated design of the CSI evolutionary structure: A verification of the design methodology

    NASA Technical Reports Server (NTRS)

    Maghami, Peiman G.; Joshi, S. M.; Elliott, Kenny B.; Walz, J. E.

    1993-01-01

    One of the main objectives of the Controls-Structures Interaction (CSI) program is to develop and evaluate integrated controls-structures design methodology for flexible space structures. Thus far, integrated design methodologies for a class of flexible spacecraft, which require fine attitude pointing and vibration suppression with no payload articulation, have been extensively investigated. Various integrated design optimization approaches, such as single-objective optimization, and multi-objective optimization, have been implemented with an array of different objectives and constraints involving performance and cost measures such as total mass, actuator mass, steady-state pointing performance, transient performance, control power, and many more. These studies have been performed using an integrated design software tool (CSI-DESIGN CODE) which is under development by the CSI-ADM team at the NASA Langley Research Center. To date, all of these studies, irrespective of the type of integrated optimization posed or objectives and constraints used, have indicated that integrated controls-structures design results in an overall spacecraft design which is considerably superior to designs obtained through a conventional sequential approach. Consequently, it is believed that validation of some of these results through fabrication and testing of a structure which is designed through an integrated design approach is warranted. The objective of this paper is to present and discuss the efforts that have been taken thus far for the validation of the integrated design methodology.

  11. Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards

    PubMed Central

    Smith, Justin D.

    2013-01-01

    This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have precluded widespread implementation and acceptance of the SCED as a viable complementary methodology to the predominant group design. This article includes a description of the research design, measurement, and analysis domains distinctive to the SCED; a discussion of the results within the framework of contemporary standards and guidelines in the field; and a presentation of updated benchmarks for key characteristics (e.g., baseline sampling, method of analysis), and overall, it provides researchers and reviewers with a resource for conducting and evaluating SCED research. The results of the systematic review of 409 studies suggest that recently published SCED research is largely in accordance with contemporary criteria for experimental quality. Analytic method emerged as an area of discord. Comparison of the findings of this review with historical estimates of the use of statistical analysis indicates an upward trend, but visual analysis remains the most common analytic method and also garners the most support amongst those entities providing SCED standards. Although consensus exists along key dimensions of single-case research design and researchers appear to be practicing within these parameters, there remains a need for further evaluation of assessment and sampling techniques and data analytic methods. PMID:22845874

  12. An assessment of the methodological quality of published network meta-analyses: a systematic review.

    PubMed

    Chambers, James D; Naci, Huseyin; Wouters, Olivier J; Pyo, Junhee; Gunjal, Shalak; Kennedy, Ian R; Hoey, Mark G; Winn, Aaron; Neumann, Peter J

    2015-01-01

    To assess the methodological quality of published network meta-analysis. Systematic review. We searched the medical literature for network meta-analyses of pharmaceuticals. We assessed general study characteristics, study transparency and reproducibility, methodological approach, and reporting of findings. We compared studies published in journals with lower impact factors with those published in journals with higher impact factors, studies published prior to January 1st, 2013 with those published after that date, and studies supported financially by industry with those supported by non-profit institutions or that received no support. The systematic literature search identified 854 citations. Three hundred and eighteen studies met our inclusion criteria. The number of network meta-analyses has grown rapidly, with 48% of studies published since January 2013. The majority of network meta-analyses were supported by a non-profit institution or received no support (68%). We found considerable inconsistencies among reviewed studies. Eighty percent reported search terms, 61% a network diagram, 65% sufficient data to replicate the analysis, and 90% the characteristics of included trials. Seventy percent performed a risk of bias assessment of included trials, 40% an assessment of model fit, and 56% a sensitivity analysis. Among studies with a closed loop, 69% examined the consistency of direct and indirect evidence. Sixty-four percent of studies presented the full matrix of head-to-head treatment comparisons. For Bayesian studies, 41% reported the probability that each treatment was best, 31% reported treatment ranking, and 16% included the model code or referenced publicly-available code. Network meta-analyses published in higher impact factors journals and those that did not receive industry support performed better across the assessment criteria. We found few differences between older and newer studies. There is substantial variation in the network meta

  13. Design Validation Methodology Development for an Aircraft Sensor Deployment System

    NASA Astrophysics Data System (ADS)

    Wowczuk, Zenovy S.

    The OCULUS 1.0 Sensor Deployment concept design, was developed in 2004 at West Virginia University (WVU), outlined the general concept of a deployment system to be used on a C-130 aircraft. As a sequel, a new system, OCULUS 1.1, has been developed and designed. The new system transfers the concept system design to a safety of flight design, and also enhanced to a pre-production system to be used as the test bed to gain full military certification approval. The OCULUS 1.1 system has an implemented standard deployment system/procedure to go along with a design suited for military certification and implementation. This design process included analysis of the system's critical components and the generation of a critical component holistic model to be used as an analysis tool for future payload modification made to the system. Following the completion of the OCULUS 1.1 design, preparations and procedures for obtaining military airworthiness certification are described. The airworthiness process includes working with the agency overseeing all modifications to the normal operating procedures made to military C-130 aircraft and preparing the system for an experimental flight test. The critical steps in his process include developing a complete documentation package that details the analysis performed on the OCULUS 1.1 system and also the design of experiment flight test plan to analyze the system. Following the approval of the documentation and design of experiment an experimental flight test of the OCULUS 1.1 system was performed to verify the safety and airworthiness of the system. This test proved successfully that the OCULUS 1.1 system design was airworthy and approved for military use. The OCULUS 1.1 deployment system offers an open architecture design that is ideal for use as a sensor testing platform for developmental airborne sensors. The system's patented deployment methodology presents a simplistic approach to reaching the systems final operating position which

  14. Combustor design and analysis using the Rocket Combustor Interactive Design (ROCCID) methodology

    NASA Technical Reports Server (NTRS)

    Klem, Mark D.; Pieper, Jerry L.; Walker, Richard E.

    1990-01-01

    The ROCket Combustor Interactive Design (ROCCID) Methodology is a newly developed, interactive computer code for the design and analysis of a liquid propellant rocket combustion chamber. The application of ROCCID to design a liquid rocket combustion chamber is illustrated. Designs for a 50,000 lbf thrust and 1250 psi chamber pressure combustor using liquid oxygen (LOX)RP-1 propellants are developed and evaluated. Tradeoffs between key design parameters affecting combustor performance and stability are examined. Predicted performance and combustion stability margin for these designs are provided as a function of the combustor operating mixture ratio and chamber pressure.

  15. Combustor design and analysis using the ROCket Combustor Interactive Design (ROCCID) Methodology

    NASA Technical Reports Server (NTRS)

    Klem, Mark D.; Pieper, Jerry L.; Walker, Richard E.

    1990-01-01

    The ROCket Combustor Interactive Design (ROCCID) Methodology is a newly developed, interactive computer code for the design and analysis of a liquid propellant rocket combustion chamber. The application of ROCCID to design a liquid rocket combustion chamber is illustrated. Designs for a 50,000 lbf thrust and 1250 psi chamber pressure combustor using liquid oxygen (LOX)RP-1 propellants are developed and evaluated. Tradeoffs between key design parameters affecting combustor performance and stability are examined. Predicted performance and combustion stability margin for these designs are provided as a function of the combustor operating mixture ratio and chamber pressure.

  16. Evaluation and optimization of hepatocyte culture media factors by design of experiments (DoE) methodology.

    PubMed

    Dong, Jia; Mandenius, Carl-Fredrik; Lübberstedt, Marc; Urbaniak, Thomas; Nüssler, Andreas K N; Knobeloch, Daniel; Gerlach, Jörg C; Zeilinger, Katrin

    2008-07-01

    Optimization of cell culture media based on statistical experimental design methodology is a widely used approach for improving cultivation conditions. We applied this methodology to refine the composition of an established culture medium for growth of a human hepatoma cell line, C3A. A selection of growth factors and nutrient supplements were systematically screened according to standard design of experiments (DoE) procedures. The results of the screening indicated that the medium additives hepatocyte growth factor, oncostatin M, and fibroblast growth factor 4 significantly influenced the metabolic activities of the C3A cell line. Surface response methodology revealed that the optimum levels for these factors were 30 ng/ml for hepatocyte growth factor and 35 ng/ml for oncostatin M. Additional experiments on primary human hepatocyte cultures showed high variance in metabolic activities between cells from different individuals, making determination of optimal levels of factors more difficult. Still, it was possible to conclude that hepatocyte growth factor, epidermal growth factor, and oncostatin M had decisive effects on the metabolic functions of primary human hepatocytes.

  17. Systematic methodological review: developing a framework for a qualitative semi-structured interview guide.

    PubMed

    Kallio, Hanna; Pietilä, Anna-Maija; Johnson, Martin; Kangasniemi, Mari

    2016-12-01

    To produce a framework for the development of a qualitative semi-structured interview guide. Rigorous data collection procedures fundamentally influence the results of studies. The semi-structured interview is a common data collection method, but methodological research on the development of a semi-structured interview guide is sparse. Systematic methodological review. We searched PubMed, CINAHL, Scopus and Web of Science for methodological papers on semi-structured interview guides from October 2004-September 2014. Having examined 2,703 titles and abstracts and 21 full texts, we finally selected 10 papers. We analysed the data using the qualitative content analysis method. Our analysis resulted in new synthesized knowledge on the development of a semi-structured interview guide, including five phases: (1) identifying the prerequisites for using semi-structured interviews; (2) retrieving and using previous knowledge; (3) formulating the preliminary semi-structured interview guide; (4) pilot testing the guide; and (5) presenting the complete semi-structured interview guide. Rigorous development of a qualitative semi-structured interview guide contributes to the objectivity and trustworthiness of studies and makes the results more plausible. Researchers should consider using this five-step process to develop a semi-structured interview guide and justify the decisions made during it. © 2016 John Wiley & Sons Ltd.

  18. Methodological Considerations in Social Cost Studies of Addictive Substances: A Systematic Literature Review.

    PubMed

    Verhaeghe, Nick; Lievens, Delfine; Annemans, Lieven; Vander Laenen, Freya; Putman, Koen

    2016-01-01

    Alcohol, tobacco, illicit drugs, and psychoactive pharmaceuticals' use is associated with a higher likelihood of developing several diseases and injuries and, as a consequence, considerable health-care expenditures. There is yet a lack of consistent methodologies to estimate the economic impact of addictive substances to society. The aim was to assess the methodological approaches applied in social cost studies estimating the economic impact of alcohol, tobacco, illicit drugs, and psychoactive pharmaceuticals. A systematic literature review through the electronic databases, Medline (PubMed) and Web of Science, was performed. Studies in English published from 1997 examining the social costs of the addictive substances alcohol, tobacco, illicit drugs, and psychoactive pharmaceuticals were eligible for inclusion. Twelve social cost studies met the inclusion criteria. In all studies, the direct and indirect costs were measured, but the intangible costs were seldom taken into account. A wide variety in cost items included across studies was observed. Sensitivity analyses to address the uncertainty around certain cost estimates were conducted in eight studies considered in the review. Differences in cost items included in cost-of-illness studies limit the comparison across studies. It is clear that it is difficult to deal with all consequences of substance use in cost-of-illness studies. Future social cost studies should be based on sound methodological principles in order to result in more reliable cost estimates of the economic burden of substance use.

  19. Towards a Methodology for the Design of Multimedia Public Access Interfaces.

    ERIC Educational Resources Information Center

    Rowley, Jennifer

    1998-01-01

    Discussion of information systems methodologies that can contribute to interface design for public access systems covers: the systems life cycle; advantages of adopting information systems methodologies; soft systems methodologies; task-oriented approaches to user interface design; holistic design, the Star model, and prototyping; the…

  20. Towards a Methodology for the Design of Multimedia Public Access Interfaces.

    ERIC Educational Resources Information Center

    Rowley, Jennifer

    1998-01-01

    Discussion of information systems methodologies that can contribute to interface design for public access systems covers: the systems life cycle; advantages of adopting information systems methodologies; soft systems methodologies; task-oriented approaches to user interface design; holistic design, the Star model, and prototyping; the…

  1. Creating innovative research designs: the 10-year Methodological Think Tank case study.

    PubMed

    Katerndahl, David; Crabtree, Benjamin

    2006-01-01

    Addressing important but complex research questions often necessitates the creation of innovative mixed methods designs. This report describes an approach to developing research designs for studying important but methodologically challenging research questions. The Methodological Think Tank has been held annually in conjunction with the Primary Care Research Methods and Statistics Conference in San Antonio since 1994. A group of 3 to 4 methodologists with expertise balanced between quantitative and qualitative backgrounds is invited by the think tank coordinators to serve on a 2-day think tank to discuss a research question selected from those submitted in response to a call for proposals. During the first half-day, these experts explore the content area with the investigator, often challenging beliefs and assumptions. During the second half-day, the think tank participants systematically prune potential approaches until a desirable research method is identified. To date, the most recent 7 think tanks have produced fundable research designs, with 1 being funded by a K award and 4 by R01 grants. All participating investigators attributed much of their success to think tank participation. Lessons learned include (1) the importance of careful selection of participating methodologists, (2) all think tank communities of inquiry must go through 4 stages of development from pseudocommunity to community, and (3) the critical importance of listening by the investigator. Researchers and academic departments could use this process locally to develop innovative research designs.

  2. Creating Innovative Research Designs: The 10-Year Methodological Think Tank Case Study

    PubMed Central

    Katerndahl, David; Crabtree, Benjamin

    2006-01-01

    PURPOSE Addressing important but complex research questions often necessitates the creation of innovative mixed methods designs. This report describes an approach to developing research designs for studying important but methodologically challenging research questions. METHODS The Methodological Think Tank has been held annually in conjunction with the Primary Care Research Methods and Statistics Conference in San Antonio since 1994. A group of 3 to 4 methodologists with expertise balanced between quantitative and qualitative backgrounds is invited by the think tank coordinators to serve on a 2-day think tank to discuss a research question selected from those submitted in response to a call for proposals. During the first half-day, these experts explore the content area with the investigator, often challenging beliefs and assumptions. During the second half-day, the think tank participants systematically prune potential approaches until a desirable research method is identified. RESULTS To date, the most recent 7 think tanks have produced fundable research designs, with 1 being funded by a K award and 4 by R01 grants. All participating investigators attributed much of their success to think tank participation. Lessons learned include (1) the importance of careful selection of participating methodologists, (2) all think tank communities of inquiry must go through 4 stages of development from pseudocommunity to community, and (3) the critical importance of listening by the investigator. CONCLUSION Researchers and academic departments could use this process locally to develop innovative research designs. PMID:17003146

  3. A new hot gas cleanup filter design methodology

    SciTech Connect

    VanOsdol, J.G.; Dennis, R.A.; Shaffer, F.D.

    1996-12-31

    The fluid dynamics of Hot Gas Cleanup (HGCU) systems having complex geometrical configurations are typically analyzed using computational fluid dynamics codes (CFD) or bench-scale laboratory test facilities called cold-flow models (CFM). At the present time, both CFD and CFM can be effectively used for simple flows limited to one or two characteristic length scales with well defined boundary conditions. This is not the situation with HGCU devices. These devices have very complex geometries, low Reynolds number, multi-phase flows that operate on multiple-length scales. For this reason, both CFD and CFM analysis cannot yet be considered as a practical engineering analysis tool for modeling the entire flow field inside HGCU systems. The thrust of this work is to provide an aerodynamic analysis methodology that can be easily applied to the complex geometries characteristic of HGCU filter vessels, but would not require the tedious numerical solution to the entire set of transport equations. The analysis methodology performs the following tasks: Predicts problem areas where ash deposition will most likely occur; Predicts residence times for particles at various locations inside the filter vessel; Lends itself quickly to major design changes; Provides a sound technical basis for more appropriate use of CFD and CFM analysis; and Provides CFD and CFM analysis in a more focused way where if is needed.

  4. Variance estimation for systematic designs in spatial surveys.

    PubMed

    Fewster, R M

    2011-12-01

    In spatial surveys for estimating the density of objects in a survey region, systematic designs will generally yield lower variance than random designs. However, estimating the systematic variance is well known to be a difficult problem. Existing methods tend to overestimate the variance, so although the variance is genuinely reduced, it is over-reported, and the gain from the more efficient design is lost. The current approaches to estimating a systematic variance for spatial surveys are to approximate the systematic design by a random design, or approximate it by a stratified design. Previous work has shown that approximation by a random design can perform very poorly, while approximation by a stratified design is an improvement but can still be severely biased in some situations. We develop a new estimator based on modeling the encounter process over space. The new "striplet" estimator has negligible bias and excellent precision in a wide range of simulation scenarios, including strip-sampling, distance-sampling, and quadrat-sampling surveys, and including populations that are highly trended or have strong aggregation of objects. We apply the new estimator to survey data for the spotted hyena (Crocuta crocuta) in the Serengeti National Park, Tanzania, and find that the reported coefficient of variation for estimated density is 20% using approximation by a random design, 17% using approximation by a stratified design, and 11% using the new striplet estimator. This large reduction in reported variance is verified by simulation.

  5. Methodological quality of studies on the measurement properties of neck pain and disability questionnaires: a systematic review.

    PubMed

    Terwee, Caroline B; Schellingerhout, Jasper M; Verhagen, Arianne P; Koes, Bart W; de Vet, Henrica C W

    2011-05-01

    The aim of this study was to obtain an overview of the methodological quality of studies on the measurement properties of neck pain and disability questionnaires and to describe how well various aspects of the design and statistical analyses of studies on measurement properties are performed. A systematic review was performed of published studies on the measurement properties of neck pain and disability questionnaires. Two reviewers independently rated the quality of the studies using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. This checklist was developed in an international Delphi consensus study. A total of 47 articles were included on the measurement properties of 8 different questionnaires. The methodological quality of the included studies was adequate on some aspects (often, adequate statistical analyses are used for assessing reliability, measurement error, and construct validity) but can be improved on other aspects. The most important methodological aspects that need to be improved are as follows: assessing unidimensionality in internal consistency analysis, stable patients and similar test conditions in studies on reliability and measurement error, and more emphasis on the relevance and comprehensiveness of the items in content validity studies. Furthermore, it is recommended that studies on construct validity and responsiveness should be based on predefined hypotheses and that better statistical methods should be used in responsiveness studies. Considering the importance of adequate measurement properties, it is concluded that, in the field of measuring neck pain and disability, there is room for improvement in the methodological quality of studies measurement properties. Copyright © 2011 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  6. A design methodology for portable software on parallel computers

    NASA Technical Reports Server (NTRS)

    Nicol, David M.; Miller, Keith W.; Chrisman, Dan A.

    1993-01-01

    This final report for research that was supported by grant number NAG-1-995 documents our progress in addressing two difficulties in parallel programming. The first difficulty is developing software that will execute quickly on a parallel computer. The second difficulty is transporting software between dissimilar parallel computers. In general, we expect that more hardware-specific information will be included in software designs for parallel computers than in designs for sequential computers. This inclusion is an instance of portability being sacrificed for high performance. New parallel computers are being introduced frequently. Trying to keep one's software on the current high performance hardware, a software developer almost continually faces yet another expensive software transportation. The problem of the proposed research is to create a design methodology that helps designers to more precisely control both portability and hardware-specific programming details. The proposed research emphasizes programming for scientific applications. We completed our study of the parallelizability of a subsystem of the NASA Earth Radiation Budget Experiment (ERBE) data processing system. This work is summarized in section two. A more detailed description is provided in Appendix A ('Programming Practices to Support Eventual Parallelism'). Mr. Chrisman, a graduate student, wrote and successfully defended a Ph.D. dissertation proposal which describes our research associated with the issues of software portability and high performance. The list of research tasks are specified in the proposal. The proposal 'A Design Methodology for Portable Software on Parallel Computers' is summarized in section three and is provided in its entirety in Appendix B. We are currently studying a proposed subsystem of the NASA Clouds and the Earth's Radiant Energy System (CERES) data processing system. This software is the proof-of-concept for the Ph.D. dissertation. We have implemented and measured

  7. Sonic Boom Mitigation Through Aircraft Design and Adjoint Methodology

    NASA Technical Reports Server (NTRS)

    Rallabhandi, Siriam K.; Diskin, Boris; Nielsen, Eric J.

    2012-01-01

    This paper presents a novel approach to design of the supersonic aircraft outer mold line (OML) by optimizing the A-weighted loudness of sonic boom signature predicted on the ground. The optimization process uses the sensitivity information obtained by coupling the discrete adjoint formulations for the augmented Burgers Equation and Computational Fluid Dynamics (CFD) equations. This coupled formulation links the loudness of the ground boom signature to the aircraft geometry thus allowing efficient shape optimization for the purpose of minimizing the impact of loudness. The accuracy of the adjoint-based sensitivities is verified against sensitivities obtained using an independent complex-variable approach. The adjoint based optimization methodology is applied to a configuration previously optimized using alternative state of the art optimization methods and produces additional loudness reduction. The results of the optimizations are reported and discussed.

  8. Development of design and analysis methodology for composite bolted joints

    NASA Astrophysics Data System (ADS)

    Grant, Peter; Sawicki, Adam

    1991-05-01

    This paper summarizes work performed to develop composite joint design methodology for use on rotorcraft primary structure, determine joint characteristics which affect joint bearing and bypass strength, and develop analytical methods for predicting the effects of such characteristics in structural joints. Experimental results have shown that bearing-bypass interaction allowables cannot be defined using a single continuous function due to variance of failure modes for different bearing-bypass ratios. Hole wear effects can be significant at moderate stress levels and should be considered in the development of bearing allowables. A computer program has been developed and has successfully predicted bearing-bypass interaction effects for the (0/+/-45/90) family of laminates using filled hole and unnotched test data.

  9. Are we talking the same paradigm? Considering methodological choices in health education systematic review.

    PubMed

    Gordon, Morris

    2016-07-01

    For the past two decades, there have been calls for medical education to become more evidence-based. Whilst previous works have described how to use such methods, there are no works discussing when or why to select different methods from either a conceptual or pragmatic perspective. This question is not to suggest the superiority of such methods, but that having a clear rationale to underpin such choices is key and should be communicated to the reader of such works. Our goal within this manuscript is to consider the philosophical alignment of these different review and synthesis modalities and how this impacts on their suitability to answer different systematic review questions within health education. The key characteristic of a systematic review that should impact the synthesis choice is discussed in detail. By clearly defining this and the related outcome expected from the review and for educators who will receive this outcome, the alignment will become apparent. This will then allow deployment of an appropriate methodology that is fit for purpose and will indeed justify the significant work needed to complete a systematic. Key items discussed are the positivist synthesis methods meta-analysis and content analysis to address questions in the form of 'whether and what' education is effective. These can be juxtaposed with the constructivist aligned thematic analysis and meta-ethnography to address questions in the form of 'why'. The concept of the realist review is also considered. It is proposed that authors of such work should describe their research alignment and the link between question, alignment and evidence synthesis method selected. The process of exploring the range of modalities and their alignment highlights gaps in the researcher's arsenal. Future works are needed to explore the impact of such changes in writing from authors of medical education systematic review.

  10. Are we talking the same paradigm? Considering methodological choices in health education systematic review

    PubMed Central

    Gordon, Morris

    2016-01-01

    Abstract For the past two decades, there have been calls for medical education to become more evidence-based. Whilst previous works have described how to use such methods, there are no works discussing when or why to select different methods from either a conceptual or pragmatic perspective. This question is not to suggest the superiority of such methods, but that having a clear rationale to underpin such choices is key and should be communicated to the reader of such works. Our goal within this manuscript is to consider the philosophical alignment of these different review and synthesis modalities and how this impacts on their suitability to answer different systematic review questions within health education. The key characteristic of a systematic review that should impact the synthesis choice is discussed in detail. By clearly defining this and the related outcome expected from the review and for educators who will receive this outcome, the alignment will become apparent. This will then allow deployment of an appropriate methodology that is fit for purpose and will indeed justify the significant work needed to complete a systematic. Key items discussed are the positivist synthesis methods meta-analysis and content analysis to address questions in the form of ‘whether and what’ education is effective. These can be juxtaposed with the constructivist aligned thematic analysis and meta-ethnography to address questions in the form of ‘why’. The concept of the realist review is also considered. It is proposed that authors of such work should describe their research alignment and the link between question, alignment and evidence synthesis method selected. The process of exploring the range of modalities and their alignment highlights gaps in the researcher’s arsenal. Future works are needed to explore the impact of such changes in writing from authors of medical education systematic review. PMID:27007488

  11. SSME Investment in Turbomachinery Inducer Impeller Design Tools and Methodology

    NASA Technical Reports Server (NTRS)

    Zoladz, Thomas; Mitchell, William; Lunde, Kevin

    2010-01-01

    Within the rocket engine industry, SSME turbomachines are the de facto standards of success with regard to meeting aggressive performance requirements under challenging operational environments. Over the Shuttle era, SSME has invested heavily in our national inducer impeller design infrastructure. While both low and high pressure turbopump failures/anomaly resolution efforts spurred some of these investments, the SSME program was a major benefactor of key areas of turbomachinery inducer-impeller research outside of flight manifest pressures. Over the past several decades, key turbopump internal environments have been interrogated via highly instrumented hot-fire and cold-flow testing. Likewise, SSME has sponsored the advancement of time accurate and cavitating inducer impeller computation fluid dynamics (CFD) tools. These investments together have led to a better understanding of the complex internal flow fields within aggressive high performing inducers and impellers. New design tools and methodologies have evolved which intend to provide confident blade designs which strike an appropriate balance between performance and self induced load management.

  12. SSME Investment in Turbomachinery Inducer Impeller Design Tools and Methodology

    NASA Technical Reports Server (NTRS)

    Zoladz, Thomas; Mitchell, William; Lunde, Kevin

    2010-01-01

    Within the rocket engine industry, SSME turbomachines are the de facto standards of success with regard to meeting aggressive performance requirements under challenging operational environments. Over the Shuttle era, SSME has invested heavily in our national inducer impeller design infrastructure. While both low and high pressure turbopump failures/anomaly resolution efforts spurred some of these investments, the SSME program was a major benefactor of key areas of turbomachinery inducer-impeller research outside of flight manifest pressures. Over the past several decades, key turbopump internal environments have been interrogated via highly instrumented hot-fire and cold-flow testing. Likewise, SSME has sponsored the advancement of time accurate and cavitating inducer impeller computation fluid dynamics (CFD) tools. These investments together have led to a better understanding of the complex internal flow fields within aggressive high performing inducers and impellers. New design tools and methodologies have evolved which intend to provide confident blade designs which strike an appropriate balance between performance and self induced load management.

  13. An NAFP Project: Use of Object Oriented Methodologies and Design Patterns to Refactor Software Design

    NASA Technical Reports Server (NTRS)

    Shaykhian, Gholam Ali; Baggs, Rhoda

    2007-01-01

    In the early problem-solution era of software programming, functional decompositions were mainly used to design and implement software solutions. In functional decompositions, functions and data are introduced as two separate entities during the design phase, and are followed as such in the implementation phase. Functional decompositions make use of refactoring through optimizing the algorithms, grouping similar functionalities into common reusable functions, and using abstract representations of data where possible; all these are done during the implementation phase. This paper advocates the usage of object-oriented methodologies and design patterns as the centerpieces of refactoring software solutions. Refactoring software is a method of changing software design while explicitly preserving its external functionalities. The combined usage of object-oriented methodologies and design patterns to refactor should also benefit the overall software life cycle cost with improved software.

  14. Methodology used in comparative studies assessing programmes of transition from paediatrics to adult care programmes: a systematic review

    PubMed Central

    Le Roux, E; Mellerio, H; Guilmin-Crépon, S; Gottot, S; Jacquin, P; Boulkedid, R; Alberti, C

    2017-01-01

    Objective To explore the methodologies employed in studies assessing transition of care interventions, with the aim of defining goals for the improvement of future studies. Design Systematic review of comparative studies assessing transition to adult care interventions for young people with chronic conditions. Data sources MEDLINE, EMBASE, ClinicalTrial.gov. Eligibility criteria for selecting studies 2 reviewers screened comparative studies with experimental and quasi-experimental designs, published or registered before July 2015. Eligible studies evaluate transition interventions at least in part after transfer to adult care of young people with chronic conditions with at least one outcome assessed quantitatively. Results 39 studies were reviewed, 26/39 (67%) published their final results and 13/39 (33%) were in progress. In 9 studies (9/39, 23%) comparisons were made between preintervention and postintervention in a single group. Randomised control groups were used in 9/39 (23%) studies. 2 (2/39, 5%) reported blinding strategies. Use of validated questionnaires was reported in 28% (11/39) of studies. In terms of reporting in published studies 15/26 (58%) did not report age at transfer, and 6/26 (23%) did not report the time of collection of each outcome. Conclusions Few evaluative studies exist and their level of methodological quality is variable. The complexity of interventions, multiplicity of outcomes, difficulty of blinding and the small groups of patients have consequences on concluding on the effectiveness of interventions. The evaluation of the transition interventions requires an appropriate and common methodology which will provide access to a better level of evidence. We identified areas for improvement in terms of randomisation, recruitment and external validity, blinding, measurement validity, standardised assessment and reporting. Improvements will increase our capacity to determine effective interventions for transition care. PMID:28131998

  15. Qualitative systematic reviews of treatment burden in stroke, heart failure and diabetes - methodological challenges and solutions.

    PubMed

    Gallacher, Katie; Jani, Bhautesh; Morrison, Deborah; Macdonald, Sara; Blane, David; Erwin, Patricia; May, Carl R; Montori, Victor M; Eton, David T; Smith, Fiona; Batty, G David; Batty, David G; Mair, Frances S

    2013-01-28

    Treatment burden can be defined as the self-care practices that patients with chronic illness must perform to respond to the requirements of their healthcare providers, as well as the impact that these practices have on patient functioning and well being. Increasing levels of treatment burden may lead to suboptimal adherence and negative outcomes. Systematic review of the qualitative literature is a useful method for exploring the patient experience of care, in this case the experience of treatment burden. There is no consensus on methods for qualitative systematic review. This paper describes the methodology used for qualitative systematic reviews of the treatment burdens identified in three different common chronic conditions, using stroke as our exemplar. Qualitative studies in peer reviewed journals seeking to understand the patient experience of stroke management were sought. Limitations of English language and year of publication 2000 onwards were set. An exhaustive search strategy was employed, consisting of a scoping search, database searches (Scopus, CINAHL, Embase, Medline & PsycINFO) and reference, footnote and citation searching. Papers were screened, data extracted, quality appraised and analysed by two individuals, with a third party for disagreements. Data analysis was carried out using a coding framework underpinned by Normalization Process Theory (NPT). A total of 4364 papers were identified, 54 were included in the review. Of these, 51 (94%) were retrieved from our database search. Methodological issues included: creating an appropriate search strategy; investigating a topic not previously conceptualised; sorting through irrelevant data within papers; the quality appraisal of qualitative research; and the use of NPT as a novel method of data analysis, shown to be a useful method for the purposes of this review. The creation of our search strategy may be of particular interest to other researchers carrying out synthesis of qualitative studies

  16. A multidisciplinary systematic literature review on frailty: overview of the methodology used by the Canadian Initiative on Frailty and Aging.

    PubMed

    Karunananthan, Sathya; Wolfson, Christina; Bergman, Howard; Béland, François; Hogan, David B

    2009-10-12

    Over the past two decades, there has been a substantial growth in the body of literature on frailty in older persons. However, there is no consensus on its definition or the criteria used to identify frailty. In response to this lack of consensus, the Canadian Initiative on Frailty and Aging carried out a set of systematic reviews of the literature in ten areas of frailty research: biological basis; social basis; prevalence; risk factors; impact; identification; prevention and management; environment and technology; health services; health and social policy. This paper describes the methodology that was developed for the systematic reviews. A Central Coordination Group (CCG) was responsible for developing the methodology. This involved the development of search strategies and keywords, article selection processes, quality assessment tools, and guidelines for the synthesis of results. Each review was conducted by two experts in the content area, with the assistance of methodologists and statisticians from the CCG. Conducting a series of systematic literature reviews involving a range of disciplines on a concept that does not have a universally accepted definition posed several conceptual and methodological challenges. The most important conceptual challenge was determining what would qualify as literature on frailty. The methodological challenges arose from our goal of structuring a consistent methodology for reviewing literature from diverse fields of research. At the outset, certain methodological guidelines were deemed essential to ensure the validity of all the reviews. Nevertheless, it was equally important to permit flexibility in the application of the proposed methodology to capture the essence of frailty research within the given fields. The results of these reviews allowed us to establish the status of current knowledge on frailty and promote collaboration between disciplines. Conducting systematic literature reviews in health science that involve multiple

  17. Design of integrated pitch axis for autopilot/autothrottle and integrated lateral axis for autopilot/yaw damper for NASA TSRV airplane using integral LQG methodology

    NASA Technical Reports Server (NTRS)

    Kaminer, Isaac; Benson, Russell A.; Coleman, Edward E.; Ebrahimi, Yaghoob S.

    1990-01-01

    Two designs are presented for control systems for the NASA Transport System Research Vehicle (TSRV) using integral Linear Quadratic Gaussian (LQG) methodology. The first is an integrated longitudinal autopilot/autothrottle design and the second design is an integrated lateral autopilot/yaw damper/sideslip controller design. It is shown that a systematic top-down approach to a complex design problem combined with proper application of modern control synthesis techniques yields a satisfactory solution in a reasonable period of time.

  18. Systematically Designed Text Enhanced with Compressed Speech Audio.

    ERIC Educational Resources Information Center

    Fulford, Catherine P.

    This study was designed to determine whether systematically designed text augmented with compressed speech could increase the number of objectives achieved and reduce the amount of learning time needed for mastery of the objectives. Subjects were 78 students from 5 Florida schools with vocational education programs. Their reading levels ranged…

  19. [Comments on methodological quality of systematic review/meta-analysis on acupuncture therapy in China].

    PubMed

    Xiong, Jun; Du, Yuan-hao

    2011-02-01

    Along with the development of evidence-based medicine, more and more systematic review/Meta-analysis papers on acupuncture therapy have been published in China. Most researches have played an important part in guiding clinical study and practice on acupuncture. However, low quality researches may mislead the users. In the present paper, we analyze shortcomings of the published papers in China about systemic review/Meta-analysis on acupuncture therapy from the methodological quality according to the assessment tool: Oxman-Guyatt Overview Quality Assessment Questionnaire(OQAQ). Moreover, we also analyze some possible factors affecting the quality of systemic review/Meta-analysis and put forward a few of measures for improving the quality of systemic review.

  20. Most systematic reviews of high methodological quality on psoriasis interventions are classified as high risk of bias using ROBIS tool.

    PubMed

    Gómez-García, Francisco; Ruano, Juan; Gay-Mimbrera, Jesus; Aguilar-Luque, Macarena; Sanz-Cabanillas, Juan Luis; Alcalde-Mellado, Patricia; Maestre-López, Beatriz; Carmona-Fernández, Pedro Jesús; González-Padilla, Marcelino; García-Nieto, Antonio Vélez; Isla-Tejera, Beatriz

    2017-09-09

    No gold standard exists to assess methodological quality of systematic reviews (SRs). Although Assessing the Methodological Quality of Systematic Reviews (AMSTAR) is widely accepted for analyzing quality, the ROBIS instrument has recently been developed. This study aimed to compare the capacity of both instruments to capture the quality of SRs concerning psoriasis interventions. Systematic literature searches were undertaken on relevant databases. For each review, methodological quality and bias risk were evaluated using the AMSTAR and ROBIS tools. Descriptive and principal component analyses were conducted to describe similarities and discrepancies between both assessment tools. We classified 139 intervention SRs as displaying high/moderate/low methodological quality and as high/low risk of bias. A high risk of bias was detected for most SRs classified as displaying high or moderate methodological quality by AMSTAR. When comparing ROBIS result profiles, responses to domain 4 signaling questions showed the greatest differences between bias risk assessments, whereas domain 2 items showed the least. When considering SRs published about psoriasis, methodological quality remains suboptimal, and the risk of bias is elevated, even for SRs exhibiting high methodological quality. Furthermore, the AMSTAR and ROBIS tools may be considered as complementary when conducting quality assessment of SRs. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Octopus: A Design Methodology for Motion Capture Wearables.

    PubMed

    Marin, Javier; Blanco, Teresa; Marin, Jose J

    2017-08-15

    Human motion capture (MoCap) is widely recognised for its usefulness and application in different fields, such as health, sports, and leisure; therefore, its inclusion in current wearables (MoCap-wearables) is increasing, and it may be very useful in a context of intelligent objects interconnected with each other and to the cloud in the Internet of Things (IoT). However, capturing human movement adequately requires addressing difficult-to-satisfy requirements, which means that the applications that are possible with this technology are held back by a series of accessibility barriers, some technological and some regarding usability. To overcome these barriers and generate products with greater wearability that are more efficient and accessible, factors are compiled through a review of publications and market research. The result of this analysis is a design methodology called Octopus, which ranks these factors and schematises them. Octopus provides a tool that can help define design requirements for multidisciplinary teams, generating a common framework and offering a new method of communication between them.

  2. Octopus: A Design Methodology for Motion Capture Wearables

    PubMed Central

    2017-01-01

    Human motion capture (MoCap) is widely recognised for its usefulness and application in different fields, such as health, sports, and leisure; therefore, its inclusion in current wearables (MoCap-wearables) is increasing, and it may be very useful in a context of intelligent objects interconnected with each other and to the cloud in the Internet of Things (IoT). However, capturing human movement adequately requires addressing difficult-to-satisfy requirements, which means that the applications that are possible with this technology are held back by a series of accessibility barriers, some technological and some regarding usability. To overcome these barriers and generate products with greater wearability that are more efficient and accessible, factors are compiled through a review of publications and market research. The result of this analysis is a design methodology called Octopus, which ranks these factors and schematises them. Octopus provides a tool that can help define design requirements for multidisciplinary teams, generating a common framework and offering a new method of communication between them. PMID:28809786

  3. Permanent catheters for recurrent ascites-a critical and systematic review of study methodology.

    PubMed

    Christensen, Lars; Wildgaard, Lorna; Wildgaard, Kim

    2016-06-01

    Management of refractory ascites traditionally includes medical treatment with diuretics or intermittent paracentesis. Patients with recurrent ascites may benefit from the use of permanent intra-abdominal catheters with more frequent drainage without hospitalization. The objective was to systematically asses the methodology of factors and endpoints reported in studies investigating permanent catheters for recurrent ascites treatment. Using a systematic search strategy, we critically assessed the methodology when treating refractory ascites using a permanent catheter. Studies critically assessed included both retro- and prospective studies. A total of 715 unique articles were found via PubMed, The Cochrane Library and Embase. Twenty-nine studies (tunnelled catheter = 12, peritoneal ports = 6 and peritoneovenous shunts = 11) with three distinct types of permanent catheters fulfilled the inclusion criteria. Only three studies reported technical success less than 100 %. Data on complications and treatment were not available in all papers; peritonitis (48 %), cellulitis (41 %), prophylactic antibiotics (48 %) and complications to catheter insertion were difficult to distinguish from advanced co-morbidity of patients. Thirteen studies (45 %) reported some type of evaluating patient experience or functional outcome, but only three studies used validated reproducible scales when assessing outcomes. Fifteen of the 29 studies included 30 patients or less. Knowledge is limited because complications and outcomes are poorly defined. The expected increase in catheter treatment of refractory ascites necessitates comparative studies, using validated patient-related outcomes, and the reporting of unambiguous complications. A proposal of variables to include in future studies is presented.

  4. Database Design Methodology and Database Management System for Computer-Aided Structural Design Optimization.

    DTIC Science & Technology

    1984-12-01

    1983). Several researchers Lillehagen and Dokkar (1982), Grabowski, Eigener and Ranch (1978), and Eberlein and Wedekind (1982) have worked on database...Proceedings of International Federation of Information Processing. pp. 335-366. Eberlein, W. and Wedekind , H., 1982, "A Methodology for Embedding Design

  5. We!Design: A Student-Centred Participatory Methodology for the Design of Educational Applications

    ERIC Educational Resources Information Center

    Triantafyllakos, George N.; Palaigeorgiou, George E.; Tsoukalas, Ioannis A.

    2008-01-01

    The development of educational applications has always been a challenging and complex issue, mainly because of the complications imposed by the cognitive and psychological aspects of student-computer interactions. This article presents a methodology, named We!Design, that tries to encounter the complexity of educational applications development…

  6. Methodological developments in searching for studies for systematic reviews: past, present and future?

    PubMed Central

    2013-01-01

    The Cochrane Collaboration was established in 1993, following the opening of the UK Cochrane Centre in 1992, at a time when searching for studies for inclusion in systematic reviews was not well-developed. Review authors largely conducted their own searches or depended on medical librarians, who often possessed limited awareness and experience of systematic reviews. Guidance on the conduct and reporting of searches was limited. When work began to identify reports of randomized controlled trials (RCTs) for inclusion in Cochrane Reviews in 1992, there were only approximately 20,000 reports indexed as RCTs in MEDLINE and none indexed as RCTs in Embase. No search filters had been developed with the aim of identifying all RCTs in MEDLINE or other major databases. This presented The Cochrane Collaboration with a considerable challenge in identifying relevant studies. Over time, the number of studies indexed as RCTs in the major databases has grown considerably and the Cochrane Central Register of Controlled Trials (CENTRAL) has become the best single source of published controlled trials, with approximately 700,000 records, including records identified by the Collaboration from Embase and MEDLINE. Search filters for various study types, including systematic reviews and the Cochrane Highly Sensitive Search Strategies for RCTs, have been developed. There have been considerable advances in the evidence base for methodological aspects of information retrieval. The Cochrane Handbook for Systematic Reviews of Interventions now provides detailed guidance on the conduct and reporting of searches. Initiatives across The Cochrane Collaboration to improve the quality inter alia of information retrieval include: the recently introduced Methodological Expectations for Cochrane Intervention Reviews (MECIR) programme, which stipulates 'mandatory’ and 'highly desirable’ standards for various aspects of review conduct and reporting including searching, the development of Standard

  7. Methodological developments in searching for studies for systematic reviews: past, present and future?

    PubMed

    Lefebvre, Carol; Glanville, Julie; Wieland, L Susan; Coles, Bernadette; Weightman, Alison L

    2013-09-25

    The Cochrane Collaboration was established in 1993, following the opening of the UK Cochrane Centre in 1992, at a time when searching for studies for inclusion in systematic reviews was not well-developed. Review authors largely conducted their own searches or depended on medical librarians, who often possessed limited awareness and experience of systematic reviews. Guidance on the conduct and reporting of searches was limited. When work began to identify reports of randomized controlled trials (RCTs) for inclusion in Cochrane Reviews in 1992, there were only approximately 20,000 reports indexed as RCTs in MEDLINE and none indexed as RCTs in Embase. No search filters had been developed with the aim of identifying all RCTs in MEDLINE or other major databases. This presented The Cochrane Collaboration with a considerable challenge in identifying relevant studies.Over time, the number of studies indexed as RCTs in the major databases has grown considerably and the Cochrane Central Register of Controlled Trials (CENTRAL) has become the best single source of published controlled trials, with approximately 700,000 records, including records identified by the Collaboration from Embase and MEDLINE. Search filters for various study types, including systematic reviews and the Cochrane Highly Sensitive Search Strategies for RCTs, have been developed. There have been considerable advances in the evidence base for methodological aspects of information retrieval. The Cochrane Handbook for Systematic Reviews of Interventions now provides detailed guidance on the conduct and reporting of searches. Initiatives across The Cochrane Collaboration to improve the quality inter alia of information retrieval include: the recently introduced Methodological Expectations for Cochrane Intervention Reviews (MECIR) programme, which stipulates 'mandatory' and 'highly desirable' standards for various aspects of review conduct and reporting including searching, the development of Standard Training

  8. Supporting Space Systems Design via Systems Dependency Analysis Methodology

    NASA Astrophysics Data System (ADS)

    Guariniello, Cesare

    assess the behavior of each system based on its internal status and on the topology of its dependencies on systems connected to it. Designers and decision makers can therefore quickly analyze and explore the behavior of complex systems and evaluate different architectures under various working conditions. The methods support educated decision making both in the design and in the update process of systems architecture, reducing the need to execute extensive simulations. In particular, in the phase of concept generation and selection, the information given by the methods can be used to identify promising architectures to be further tested and improved, while discarding architectures that do not show the required level of global features. The methods, when used in conjunction with appropriate metrics, also allow for improved reliability and risk analysis, as well as for automatic scheduling and re-scheduling based on the features of the dependencies and on the accepted level of risk. This dissertation illustrates the use of the two methods in sample aerospace applications, both in the operational and in the developmental domain. The applications show how to use the developed methodology to evaluate the impact of failures, assess the criticality of systems, quantify metrics of interest, quantify the impact of delays, support informed decision making when scheduling the development of systems and evaluate the achievement of partial capabilities. A larger, well-framed case study illustrates how the Systems Operational Dependency Analysis method and the Systems Developmental Dependency Analysis method can support analysis and decision making, at the mid and high level, in the design process of architectures for the exploration of Mars. The case study also shows how the methods do not replace the classical systems engineering methodologies, but support and improve them.

  9. Idiopathic pulmonary fibrosis - a systematic review on methodology for the collection of epidemiological data

    PubMed Central

    2013-01-01

    Background Recent studies suggest that the incidence of idiopathic pulmonary fibrosis (IPF) is rising. Accurate epidemiological data on IPF, however, are sparse and the results of previous studies are contradictory. This study was undertaken to gain insight into the various methods used in the epidemiological research of IPF, and to get accurate and comparable data on these different methodologies. Methods A systematic database search was performed in order to identify all epidemiological studies on IPF after the previous guidelines for diagnosis and treatment were published in 2000. Medline (via Pubmed), Science Sitation Index (via Web of Science) and Embase databases were searched for original epidemiological articles published in English in international peer-reviewed journals starting from 2001. After pre-screening and a full-text review, 13 articles were accepted for data abstraction. Results Three different methodologies of epidemiological studies were most commonly used, namely: 1) national registry databases, 2) questionnaire-based studies, and 3) analysis of the health care system’s own registry databases. The overall prevalence and incidence of IPF varied in these studies between 0.5–27.9/100,000 and 0.22–8.8/100,000, respectively. According to four studies the mortality and incidence of IPF are rising. Conclusions We conclude that there are numerous ways to execute epidemiological research in the field of IPF. This review offers the possibility to compare the different methodologies that have been used, and this information could form a basis for future studies investigating the prevalence and incidence of IPF. PMID:23962167

  10. Systematic review of sensory integration therapy for individuals with disabilities: Single case design studies.

    PubMed

    Leong, H M; Carter, Mark; Stephenson, Jennifer

    2015-12-01

    Sensory integration therapy (SIT) is a controversial intervention that is widely used for people with disabilities. Systematic analysis was conducted on the outcomes of 17 single case design studies on sensory integration therapy for people with, or at-risk of, a developmental or learning disability, disorder or delay. An assessment of the quality of methodology of the studies found most used weak designs and poor methodology, with a tendency for higher quality studies to produce negative results. Based on limited comparative evidence, functional analysis-based interventions for challenging behavior were more effective that SIT. Overall the studies do not provide convincing evidence for the efficacy of sensory integration therapy. Given the findings of the present review and other recent analyses it is advised that the use of SIT be limited to experimental contexts. Issues with the studies and possible improvements for future research are discussed including the need to employ designs that allow for adequate demonstration of experimental control.

  11. Arab Teens Lifestyle Study (ATLS): objectives, design, methodology and implications

    PubMed Central

    Al-Hazzaa, Hazzaa M; Musaiger, Abdulrahman O

    2011-01-01

    Background There is a lack of comparable data on physical activity, sedentary behavior, and dietary habits among Arab adolescents, which limits our understanding and interpretation of the relationship between obesity and lifestyle parameters. Therefore, we initiated the Arab Teens Lifestyle Study (ATLS). The ATLS is a multicenter collaborative project for assessing lifestyle habits of Arab adolescents. The objectives of the ATLS project were to investigate the prevalence rates for overweight and obesity, physical activity, sedentary activity and dietary habits among Arab adolescents, and to examine the interrelationships between these lifestyle variables. This paper reports on the objectives, design, methodology, and implications of the ATLS. Design/Methods The ATLS is a school-based cross-sectional study involving 9182 randomly selected secondary-school students (14–19 years) from major Arab cities, using a multistage stratified sampling technique. The participating Arab cities included Riyadh, Jeddah, and Al-Khobar (Saudi Arabia), Bahrain, Dubai (United Arab Emirates), Kuwait, Amman (Jordan), Mosel (Iraq), Muscat (Oman), Tunisia (Tunisia) and Kenitra (Morocco). Measured variables included anthropometric measurements, physical activity, sedentary behavior, sleep duration, and dietary habits. Discussion The ATLS project will provide a unique opportunity to collect and analyze important lifestyle information from Arab adolescents using standardized procedures. This is the first time a collaborative Arab project will simultaneously assess broad lifestyle variables in a large sample of adolescents from numerous urbanized Arab regions. This joint research project will supply us with comprehensive and recent data on physical activity/inactivity and eating habits of Arab adolescents relative to obesity. Such invaluable lifestyle-related data are crucial for developing public health policies and regional strategies for health promotion and disease prevention. PMID

  12. Optimal input design for aircraft instrumentation systematic error estimation

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    1991-01-01

    A new technique for designing optimal flight test inputs for accurate estimation of instrumentation systematic errors was developed and demonstrated. A simulation model of the F-18 High Angle of Attack Research Vehicle (HARV) aircraft was used to evaluate the effectiveness of the optimal input compared to input recorded during flight test. Instrumentation systematic error parameter estimates and their standard errors were compared. It was found that the optimal input design improved error parameter estimates and their accuracies for a fixed time input design. Pilot acceptability of the optimal input design was demonstrated using a six degree-of-freedom fixed base piloted simulation of the F-18 HARV. The technique described in this work provides a practical, optimal procedure for designing inputs for data compatibility experiments.

  13. Optimal input design for aircraft instrumentation systematic error estimation

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    1991-01-01

    A new technique for designing optimal flight test inputs for accurate estimation of instrumentation systematic errors was developed and demonstrated. A simulation model of the F-18 High Angle of Attack Research Vehicle (HARV) aircraft was used to evaluate the effectiveness of the optimal input compared to input recorded during flight test. Instrumentation systematic error parameter estimates and their standard errors were compared. It was found that the optimal input design improved error parameter estimates and their accuracies for a fixed time input design. Pilot acceptability of the optimal input design was demonstrated using a six degree-of-freedom fixed base piloted simulation of the F-18 HARV. The technique described in this work provides a practical, optimal procedure for designing inputs for data compatibility experiments.

  14. Self-efficacy instruments for patients with chronic diseases suffer from methodological limitations - a systematic review

    PubMed Central

    Frei, Anja; Svarin, Anna; Steurer-Stey, Claudia; Puhan, Milo A

    2009-01-01

    instruments was often not specified and for most instruments, not all measurement properties that are important to support the specific aim of the instrument (for example responsiveness for evaluative instruments) were assessed. Researchers who develop and validate self-efficacy instruments should adhere more closely to important methodological concepts for development and validation of patient-reported outcomes and report their methods more transparently. We propose a systematic five step approach for the development and validation of self-efficacy instruments. PMID:19781095

  15. Gaining system design knowledge by systematic design space exploration with graph based design languages

    NASA Astrophysics Data System (ADS)

    Schmidt, Jens; Rudolph, Stephan

    2014-10-01

    The conceptual design phase in the design of complex systems such as satellite propulsion systems heavily relies on an exploration of the feasible design space. This exploration requires both: topological changes in the potential system architecture and consistent parametrical changes in the dimensioning of the existing system components. Since advanced engineering design techniques nowadays advocate a model-based systems engineering (MBSE) approach, graph-based design languages which embed a superset of MBSE-features are consequently used in this work to systematically explore the feasible design space. Design languages allow the design knowledge to be represented, modeled and executed using model-based transformations and combine this among other features with constraint processing techniques. The execution of the design language shown for the satellite propulsion systems in this work yields topologically varied designs (i.e. the selection of a monergol, a diergol or a coldgas system) with consistent parameters. Based on an a posteriori performance analysis of the automatically generated system designs, novel system knowledge (most notably in form of so-called "topology change points") can be gained and extracted from the original point cloud of numerical results.

  16. Case-crossover study design in pharmacoepidemiology: systematic review and recommendations.

    PubMed

    Consiglio, Giulia P; Burden, Andrea M; Maclure, Malcolm; McCarthy, Lisa; Cadarette, Suzanne M

    2013-11-01

    The purpose of this study is to systematically identify and review articles that use the case-crossover study design in the area of pharmacoepidemiology. A systematic search of MEDLINE® (Ovid Technologies, New York City, NY, USA), EMBASE® (Elsevier Inc., Philadelphia, PA, USA), and Web of Science® (Thomson Reuters, New York City, NY, USA) was completed to identify all English language articles that applied the case-crossover study design in the area of pharmacoepidemiology. The number of reviews, methodological contributions, and empirical pharmacoepidemiologic applications were summarized by publication year. Empirical applications were retrieved, and methodological details (outcome, exposure, exposure windows, sensitivity analysis, statistical reporting) were tabulated and compared to methodological recommendations based on exposure characteristics, exposure windows, and discordant pairs data display. Of 836 unique articles identified, 99 pharmacoepidemiologic studies were eligible: 20 methodological contributions, 9 review papers, and 70 empirical applications. Only three empirical applications in the area of pharmacoepidemiology were published before 2000. Since 2000, the number of empirical pharmacoepidemiologic applications published annually has generally increased over time, to before a high of 15 published in 2011. The design was mainly applied to examine drug safety (96%), and most applications investigated: psychotropic (24%) and analgesic (17%) exposure drug classes; and considered hospitalization (23%) and cardiovascular/cerebrovascular (21%) events. Only 31% of applications displayed sufficient data to enable readers to confirm odds ratios presented. Use of the case-crossover design in pharmacoepidemiology has increased rapidly in the last decade. As the application of the case-crossover design continues to increase, it is important to develop standards of practice, especially for display of data. Copyright © 2013 John Wiley & Sons, Ltd.

  17. Multidisciplinary design and optimization (MDO) methodology for the aircraft conceptual design

    NASA Astrophysics Data System (ADS)

    Iqbal, Liaquat Ullah

    An integrated design and optimization methodology has been developed for the conceptual design of an aircraft. The methodology brings higher fidelity Computer Aided Design, Engineering and Manufacturing (CAD, CAE and CAM) Tools such as CATIA, FLUENT, ANSYS and SURFCAM into the conceptual design by utilizing Excel as the integrator and controller. The approach is demonstrated to integrate with many of the existing low to medium fidelity codes such as the aerodynamic panel code called CMARC and sizing and constraint analysis codes, thus providing the multi-fidelity capabilities to the aircraft designer. The higher fidelity design information from the CAD and CAE tools for the geometry, aerodynamics, structural and environmental performance is provided for the application of the structured design methods such as the Quality Function Deployment (QFD) and the Pugh's Method. The higher fidelity tools bring the quantitative aspects of a design such as precise measurements of weight, volume, surface areas, center of gravity (CG) location, lift over drag ratio, and structural weight, as well as the qualitative aspects such as external geometry definition, internal layout, and coloring scheme early in the design process. The performance and safety risks involved with the new technologies can be reduced by modeling and assessing their impact more accurately on the performance of the aircraft. The methodology also enables the design and evaluation of the novel concepts such as the blended (BWB) and the hybrid wing body (HWB) concepts. Higher fidelity computational fluid dynamics (CFD) and finite element analysis (FEA) allow verification of the claims for the performance gains in aerodynamics and ascertain risks of structural failure due to different pressure distribution in the fuselage as compared with the tube and wing design. The higher fidelity aerodynamics and structural models can lead to better cost estimates that help reduce the financial risks as well. This helps in

  18. A combined stochastic feedforward and feedback control design methodology with application to autoland design

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim

    1987-01-01

    A combined stochastic feedforward and feedback control design methodology was developed. The objective of the feedforward control law is to track the commanded trajectory, whereas the feedback control law tries to maintain the plant state near the desired trajectory in the presence of disturbances and uncertainties about the plant. The feedforward control law design is formulated as a stochastic optimization problem and is embedded into the stochastic output feedback problem where the plant contains unstable and uncontrollable modes. An algorithm to compute the optimal feedforward is developed. In this approach, the use of error integral feedback, dynamic compensation, control rate command structures are an integral part of the methodology. An incremental implementation is recommended. Results on the eigenvalues of the implemented versus designed control laws are presented. The stochastic feedforward/feedback control methodology is used to design a digital automatic landing system for the ATOPS Research Vehicle, a Boeing 737-100 aircraft. The system control modes include localizer and glideslope capture and track, and flare to touchdown. Results of a detailed nonlinear simulation of the digital control laws, actuator systems, and aircraft aerodynamics are presented.

  19. A Synergy between the Technological Process and a Methodology for Web Design: Implications for Technological Problem Solving and Design

    ERIC Educational Resources Information Center

    Jakovljevic, Maria; Ankiewicz, Piet; De swardt, Estelle; Gross, Elna

    2004-01-01

    Traditional instructional methodology in the Information System Design (ISD) environment lacks explicit strategies for promoting the cognitive skills of prospective system designers. This contributes to the fragmented knowledge and low motivational and creative involvement of learners in system design tasks. In addition, present ISD methodologies,…

  20. A Synergy between the Technological Process and a Methodology for Web Design: Implications for Technological Problem Solving and Design

    ERIC Educational Resources Information Center

    Jakovljevic, Maria; Ankiewicz, Piet; De swardt, Estelle; Gross, Elna

    2004-01-01

    Traditional instructional methodology in the Information System Design (ISD) environment lacks explicit strategies for promoting the cognitive skills of prospective system designers. This contributes to the fragmented knowledge and low motivational and creative involvement of learners in system design tasks. In addition, present ISD methodologies,…

  1. Bioslurry phase remediation of chlorpyrifos contaminated soil: process evaluation and optimization by Taguchi design of experimental (DOE) methodology.

    PubMed

    Venkata Mohan, S; Sirisha, K; Sreenivasa Rao, R; Sarma, P N

    2007-10-01

    Design of experimental (DOE) methodology using Taguchi orthogonal array (OA) was applied to evaluate the influence of eight biotic and abiotic factors (substrate-loading rate, slurry phase pH, slurry phase dissolved oxygen (DO), soil water ratio, temperature, soil microflora load, application of bioaugmentation and humic substance concentration) on the soil bound chlorpyrifos bioremediation in bioslurry phase reactor. The selected eight factors were considered at three levels (18 experiments) in the experimental design. Substrate-loading rate showed significant influence on the bioremediation process among the selected factors. Derived optimum operating conditions obtained by the methodology showed enhanced chlorpyrifos degradation from 1479.99 to 2458.33microg/g (over all 39.82% enhancement). The proposed method facilitated systematic mathematical approach to understand the complex bioremediation process and the optimization of near optimum design parameters, only with a few well-defined experimental sets.

  2. Designs and Methods in School Improvement Research: A Systematic Review

    ERIC Educational Resources Information Center

    Feldhoff, Tobias; Radisch, Falk; Bischof, Linda Marie

    2016-01-01

    Purpose: The purpose of this paper is to focus on challenges faced by longitudinal quantitative analyses of school improvement processes and offers a systematic literature review of current papers that use longitudinal analyses. In this context, the authors assessed designs and methods that are used to analyze the relation between school…

  3. A SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation and analysis of multiple objectives are very important in designing environmentally benign processes. They require a systematic procedure for solving multi-objective decision-making problems due to the complex nature of the problems and the need for complex assessment....

  4. Designs and Methods in School Improvement Research: A Systematic Review

    ERIC Educational Resources Information Center

    Feldhoff, Tobias; Radisch, Falk; Bischof, Linda Marie

    2016-01-01

    Purpose: The purpose of this paper is to focus on challenges faced by longitudinal quantitative analyses of school improvement processes and offers a systematic literature review of current papers that use longitudinal analyses. In this context, the authors assessed designs and methods that are used to analyze the relation between school…

  5. A SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation and analysis of multiple objectives are very important in designing environmentally benign processes. They require a systematic procedure for solving multi-objective decision-making problems due to the complex nature of the problems and the need for complex assessment....

  6. Checklists of Methodological Issues for Review Authors to Consider When Including Non-Randomized Studies in Systematic Reviews

    ERIC Educational Resources Information Center

    Wells, George A.; Shea, Beverley; Higgins, Julian P. T.; Sterne, Jonathan; Tugwell, Peter; Reeves, Barnaby C.

    2013-01-01

    Background: There is increasing interest from review authors about including non-randomized studies (NRS) in their systematic reviews of health care interventions. This series from the Ottawa Non-Randomized Studies Workshop consists of six papers identifying methodological issues when doing this. Aim: To format the guidance from the preceding…

  7. Checklists of Methodological Issues for Review Authors to Consider When Including Non-Randomized Studies in Systematic Reviews

    ERIC Educational Resources Information Center

    Wells, George A.; Shea, Beverley; Higgins, Julian P. T.; Sterne, Jonathan; Tugwell, Peter; Reeves, Barnaby C.

    2013-01-01

    Background: There is increasing interest from review authors about including non-randomized studies (NRS) in their systematic reviews of health care interventions. This series from the Ottawa Non-Randomized Studies Workshop consists of six papers identifying methodological issues when doing this. Aim: To format the guidance from the preceding…

  8. Evaluation of methodology and quality characteristics of systematic reviews in orthodontics.

    PubMed

    Papageorgiou, S N; Papadopoulos, M A; Athanasiou, A E

    2011-08-01

    Systematic reviews (SRs) are published with an increasing rate in many fields of biomedical literature, including orthodontics. Although SRs should consolidate the evidence-based characteristics of contemporary orthodontic practice, doubts on the validity of their conclusions have been frequently expressed. The aim of this study was to evaluate the methodology and quality characteristics of orthodontic SRs as well as to assess their quality of reporting during the last years. Electronic databases were searched for SRs (without any meta-analytical data synthesis) in the field of orthodontics, indexed up to the start of 2010. The Assessment of Multiple Systematic Reviews (AMSTAR) tool was used for quality assessment of the included articles. Data were analyzed with Student's t-test, one-way ANOVA, and linear regression. Risk ratios (RR) with 95% confidence intervals were calculated to represent changes during the years in reporting of key items associated with quality. A total of 110 SRs were included in this evaluation. About half of the SRs (46.4%) were published in orthodontic journals, while few (5.5%) were updates of previously published reviews. Using the AMSTAR tool, thirty (27.3%) of the SRs were found to be of low quality, 63 (57.3%) of medium quality, and 17 (15.5%) of high quality. No significant trend for quality improvement was observed during the last years. The overall quality of orthodontic SRs may be considered as medium. Although the number of orthodontic SRs has increased over the last decade, their quality characteristics can be characterized as moderate.

  9. The uniqueness of the human dentition as forensic evidence: a systematic review on the technological methodology.

    PubMed

    Franco, Ademir; Willems, Guy; Souza, Paulo Henrique Couto; Bekkering, Geertruida E; Thevissen, Patrick

    2015-11-01

    The uniqueness of human dentition is routinely approached as identification evidence in forensic odontology. Specifically in bitemark and human identification cases, positive identifications are obtained under the hypothesis that two individuals do not have the same dental features. The present study compiles methodological information from articles on the uniqueness of human dentition to support investigations into the mentioned hypothesis. In April 2014, three electronic library databases (SciELO®, MEDLINE®/PubMed®, and LILACS®) were systematically searched. In parallel, reference lists of relevant studies were also screened. From the obtained articles (n = 1235), 13 full-text articles were considered eligible. They were examined according to the studied parameters: the sample size, the number of examined teeth, the registration technique for data collection, the methods for data analysis, and the study outcomes. Six combinations of studied data were detected: (1) dental shape, size, angulation, and position (n = 1); (2) dental shape, size, and angulation (n = 4); (3) dental shape and size (n = 5); (4) dental angulation and position (n = 2); (5) dental shape and angulation (n = 1); and (6) dental shape (n = 1). The sample size ranged between 10 and 1099 human dentitions. Ten articles examined the six anterior teeth, while three articles examined more teeth. Four articles exclusively addressed three-dimensional (3D) data registration, while six articles used two-dimensional (2D) imaging. In three articles, both imaging registrations were combined. Most articles (n = 9) explored the data using landmark placement. The other articles (n = 4) comprised digital comparison of superimposed dental contours. Although there were large methodological variations within the investigated articles, the uniqueness of human dentition remains unproved.

  10. 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

  11. Arab Teens Lifestyle Study (ATLS): objectives, design, methodology and implications.

    PubMed

    Al-Hazzaa, Hazzaa M; Musaiger, Abdulrahman O

    2011-01-01

    There is a lack of comparable data on physical activity, sedentary behavior, and dietary habits among Arab adolescents, which limits our understanding and interpretation of the relationship between obesity and lifestyle parameters. Therefore, we initiated the Arab Teens Lifestyle Study (ATLS). The ATLS is a multicenter collaborative project for assessing lifestyle habits of Arab adolescents. The objectives of the ATLS project were to investigate the prevalence rates for overweight and obesity, physical activity, sedentary activity and dietary habits among Arab adolescents, and to examine the interrelationships between these lifestyle variables. This paper reports on the objectives, design, methodology, and implications of the ATLS. The ATLS is a school-based cross-sectional study involving 9182 randomly selected secondary-school students (14-19 years) from major Arab cities, using a multistage stratified sampling technique. The participating Arab cities included Riyadh, Jeddah, and Al-Khobar (Saudi Arabia), Bahrain, Dubai (United Arab Emirates), Kuwait, Amman (Jordan), Mosel (Iraq), Muscat (Oman), Tunisia (Tunisia) and Kenitra (Morocco). Measured variables included anthropometric measurements, physical activity, sedentary behavior, sleep duration, and dietary habits. The ATLS project will provide a unique opportunity to collect and analyze important lifestyle information from Arab adolescents using standardized procedures. This is the first time a collaborative Arab project will simultaneously assess broad lifestyle variables in a large sample of adolescents from numerous urbanized Arab regions. This joint research project will supply us with comprehensive and recent data on physical activity/inactivity and eating habits of Arab adolescents relative to obesity. Such invaluable lifestyle-related data are crucial for developing public health policies and regional strategies for health promotion and disease prevention.

  12. An Examination of the MH-60S Common Cockpit from a Design Methodology and Acquisitions Standpoint

    DTIC Science & Technology

    2009-06-01

    HCI Design Methodology Based on the CCD Philosophy ...................................51 a. Use of Design Methodology Specifically Developed for...19 Figure 8. Lockheed Martin Human Computer Interface Requirements (HCIRS) contents (From: [6]).......36 Figure 9. Lockheed Martin eight step HCI ...function of time (From: [9]).....................................46 Figure 15. Systems engineering iterative HCI design process (From [10

  13. A rational design change methodology based on experimental and analytical modal analysis

    SciTech Connect

    Weinacht, D.J.; Bennett, J.G.

    1993-08-01

    A design methodology that integrates analytical modeling and experimental characterization is presented. This methodology represents a powerful tool for making rational design decisions and changes. An example of its implementation in the design, analysis, and testing of a precisions machine tool support structure is given.

  14. Methodological quality of systematic reviews referenced in clinical practice guidelines for the treatment of opioid use disorder.

    PubMed

    Ross, Andrew; Rankin, Justin; Beaman, Jason; Murray, Kelly; Sinnett, Philip; Riddle, Ross; Haskins, Jordan; Vassar, Matt

    2017-01-01

    With efforts to combat opioid use disorder, there is an increased interest in clinical practice guidelines (CPGs) for opioid use disorder treatments. No literature exists examining the quality of systematic reviews used in opioid use disorder CPGs. This study aims to describe the methodological quality and reporting clarity of systematic reviews (SRs) used to create CPGs for opioid use disorder. From June to July 2016 guideline clearinghouses and medical literature databases were searched for relevant CPGs used in the treatment of opioid use disorder. Included CPGs must have been recognized by a national organization. SRs from the reference section of each CPG was scored by using AMSTAR (a measurement tool to assess the methodological quality of systematic reviews) tool and PRISMA (preferred reporting items for systematic reviews and meta-analyses) checklist. Seventeen CPGs from 2006-2016 were included in the review. From these, 57 unique SRs were extracted. SRS comprised 0.28% to 17.92% of all references found in the CPGs. All SRs obtained moderate or high methodological quality score on the AMSTAR tool. All reviews met at least 70% of PRISMA criteria. In PRISMA, underperforming areas included accurate title labeling, protocol registration, and risk of bias. Underperforming areas in AMSTAR included conflicts of interest, funding, and publication bias. A positive correlation was found between AMSTAR and PRISMA scores (r = .79). Although the SRs in the CPGs were of good quality, there are still areas for improvement. Systematic reviewers should consult PRISMA and AMSTAR when conducting and reporting reviews. It is important for CPG developers to consider methodological quality as a factor when developing CPG recommendations, recognizing that the quality of systematic reviews underpinning guidelines does not necessarily correspond to the quality of the guideline itself.

  15. Methodological quality of systematic reviews referenced in clinical practice guidelines for the treatment of opioid use disorder

    PubMed Central

    Rankin, Justin; Beaman, Jason; Murray, Kelly; Sinnett, Philip; Riddle, Ross; Haskins, Jordan; Vassar, Matt

    2017-01-01

    Introduction With efforts to combat opioid use disorder, there is an increased interest in clinical practice guidelines (CPGs) for opioid use disorder treatments. No literature exists examining the quality of systematic reviews used in opioid use disorder CPGs. This study aims to describe the methodological quality and reporting clarity of systematic reviews (SRs) used to create CPGs for opioid use disorder. Methods From June to July 2016 guideline clearinghouses and medical literature databases were searched for relevant CPGs used in the treatment of opioid use disorder. Included CPGs must have been recognized by a national organization. SRs from the reference section of each CPG was scored by using AMSTAR (a measurement tool to assess the methodological quality of systematic reviews) tool and PRISMA (preferred reporting items for systematic reviews and meta-analyses) checklist. Results Seventeen CPGs from 2006–2016 were included in the review. From these, 57 unique SRs were extracted. SRS comprised 0.28% to 17.92% of all references found in the CPGs. All SRs obtained moderate or high methodological quality score on the AMSTAR tool. All reviews met at least 70% of PRISMA criteria. In PRISMA, underperforming areas included accurate title labeling, protocol registration, and risk of bias. Underperforming areas in AMSTAR included conflicts of interest, funding, and publication bias. A positive correlation was found between AMSTAR and PRISMA scores (r = .79). Conclusion Although the SRs in the CPGs were of good quality, there are still areas for improvement. Systematic reviewers should consult PRISMA and AMSTAR when conducting and reporting reviews. It is important for CPG developers to consider methodological quality as a factor when developing CPG recommendations, recognizing that the quality of systematic reviews underpinning guidelines does not necessarily correspond to the quality of the guideline itself. PMID:28771633

  16. Development of the Spanish version of the Systematized Nomenclature of Medicine: methodology and main issues.

    PubMed Central

    Reynoso, G. A.; March, A. D.; Berra, C. M.; Strobietto, R. P.; Barani, M.; Iubatti, M.; Chiaradio, M. P.; Serebrisky, D.; Kahn, A.; Vaccarezza, O. A.; Leguiza, J. L.; Ceitlin, M.; Luna, D. A.; Bernaldo de Quirós, F. G.; Otegui, M. I.; Puga, M. C.; Vallejos, M.

    2000-01-01

    This presentation features linguistic and terminology management issues related to the development of the Spanish version of the Systematized Nomenclature of Medicine (SNOMED). It aims at describing the aspects of translating and the difficulties encountered in delivering a natural and consistent medical nomenclature. Bunge's three-layered model is referenced to analyze the sequence of symbolic concept representations. It further explains how a communicative translation based on a concept-to-concept approach was used to achieve the highest level of flawlessness and naturalness for the Spanish rendition of SNOMED. Translation procedures and techniques are described and exemplified. Both the computer-aided and human translation methods are portrayed. The scientific and translation team tasks are detailed, with focus on Newmark's four-level principle for the translation process, extended with a fifth further level relevant to the ontology to control the consistency of the typology of concepts. Finally the convenience for a common methodology to develop non-English versions of SNOMED is suggested. PMID:11079973

  17. Methodological systematic review identifies major limitations in prioritization processes for updating.

    PubMed

    Martínez García, Laura; Pardo-Hernandez, Hector; Superchi, Cecilia; Niño de Guzman, Ena; Ballesteros, Monica; Ibargoyen Roteta, Nora; McFarlane, Emma; Posso, Margarita; Roqué I Figuls, Marta; Rotaeche Del Campo, Rafael; Sanabria, Andrea Juliana; Selva, Anna; Solà, Ivan; Vernooij, Robin W M; Alonso-Coello, Pablo

    2017-06-01

    The aim of the study was to identify and describe strategies to prioritize the updating of systematic reviews (SRs), health technology assessments (HTAs), or clinical guidelines (CGs). We conducted an SR of studies describing one or more methods to prioritize SRs, HTAs, or CGs for updating. We searched MEDLINE (PubMed, from 1966 to August 2016) and The Cochrane Methodology Register (The Cochrane Library, Issue 8 2016). We hand searched abstract books, reviewed reference lists, and contacted experts. Two reviewers independently screened the references and extracted data. We included 14 studies. Six studies were classified as descriptive (6 of 14, 42.9%) and eight as implementation studies (8 of 14, 57.1%). Six studies reported an updating strategy (6 of 14, 42.9%), six a prioritization process (6 of 14, 42.9%), and two a prioritization criterion (2 of 14, 14.2%). Eight studies focused on SRs (8 of 14, 57.1%), six studies focused on CGs (6 of 14, 42.9%), and none were about HTAs. We identified 76 prioritization criteria that can be applied when prioritizing documents for updating. The most frequently cited criteria were as follows: available evidence (19 of 76, 25.0%), clinical relevance (10 of 76; 13.2%), and users' interest (10 of 76; 13.2%). There is wide variability and suboptimal reporting of the methods used to develop and implement processes to prioritize updating of SRs, HTAs, and CGs. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Systematic CT Methodology for the Evaluation of Subclinical Leaflet Thrombosis.

    PubMed

    Jilaihawi, Hasan; Asch, Federico M; Manasse, Eric; Ruiz, Carlos E; Jelnin, Vladimir; Kashif, Mohammad; Kawamori, Hiroyuki; Maeno, Yoshio; Kazuno, Yoshio; Takahashi, Nobuyuki; Olson, Richard; Alkhatib, Joe; Berman, Daniel; Friedman, John; Gellada, Norman; Chakravarty, Tarun; Makkar, Raj R

    2017-04-01

    Subclinical leaflet thrombosis was recently described in a randomized trial of transcatheter aortic valve replacement. It was subsequently demonstrated in a series of registries that this was a commonly observed imaging finding seen in all transcatheter and surgical bioprostheses. The phenomenon has aroused considerable interest due to the as-yet-undefined risk for later clinical events and the possibility of pharmacological intervention with anticoagulation. Subclinical leaflet thrombosis is easily detected noninvasively by technically suitable computed tomography (CT) with a high degree of concordance to transesophageal echocardiography findings. The CT hallmarks were noted to be hypoattenuated leaflet thickening (HALT) associated with reduced leaflet motion (RELM). The combination of HALT and RELM signified hypoattenuation affecting motion, the standardized imaging endpoint used. This paper describes the systematic CT evaluation methodology that was devised during the Portico trial investigation and U.S. Food and Drug Administration submission; it also highlights the need for an ongoing discussion among experts to enable, with the help of the Valve Academic Research Consortium, standardization of reporting of this imaging finding to cater to the present and future needs of clinical trials.

  19. A critical appraisal of the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing interventions: a systematic review of reviews.

    PubMed

    Jin, Ying-Hui; Wang, Guo-Hao; Sun, Yi-Rong; Li, Qi; Zhao, Chen; Li, Ge; Si, Jin-Hua; Li, Yan; Lu, Cui; Shang, Hong-Cai

    2016-11-14

    To assess the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing (TCMN) interventions in Chinese journals. These interventions include acupressure, massage, Tai Chi, Qi Gong, electroacupuncture and use of Chinese herbal medicines-for example, in enemas, foot massage and compressing the umbilicus. A systematic literature search for systematic reviews and meta-analyses of TCMN interventions was performed. Review characteristics were extracted. The methodological quality and the quality of the evidence were evaluated using the Assessment of Multiple Systematic Reviews (AMSTAR) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) approaches. We included 20 systematic reviews and meta-analyses, and a total of 11 TCMN interventions were assessed in the 20 reviews. The compliance with AMSTAR checklist items ranged from 4.5 to 8 and systematic reviews/meta-analyses were, on average, of medium methodological quality. The quality of the evidence we assessed ranged from very low to moderate; no high-quality evidence was found. The top two causes for downrating confidence in effect estimates among the 31 bodies of evidence assessed were the risk of bias and inconsistency. There is room for improvement in the methodological quality of systematic reviews/meta-analyses of TCMN interventions published in Chinese journals. Greater efforts should be devoted to ensuring a more comprehensive search strategy, clearer specification of the interventions of interest in the eligibility criteria and identification of meaningful outcomes for clinicians and patients (consumers). The overall quality of evidence among reviews remains suboptimal, which raise concerns about their roles in influencing clinical practice. Thus, the conclusions in reviews we assessed must be treated with caution and their roles in influencing clinical practice should be limited. A critical appraisal of systematic reviews

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-05-01

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

  2. A systematic-heuristic approach for space trajectory design.

    PubMed

    Vasile, Massimiliano

    2004-05-01

    In this paper a novel algorithm is proposed for space trajectory design that combines a systematic and a heuristic method for global optimization. For the systematic part of the algorithm a branching technique is used, whereas a particular implementation of evolution programming forms the core of the heuristic part. The idea is to use a limited population evolving for a small number of generations, according to specific evolution rules, in subregions of the solution space defined by a branching procedure. On the other hand the branching rules are functions of the outcome from the evolution optimization. The proposed combined systematic-heuristic global optimization performs quite well on the cases analyzed in this paper, suggesting the possibility of more complex applications.

  3. Design methodology of the strength properties of medical knitted meshes

    NASA Astrophysics Data System (ADS)

    Mikołajczyk, Z.; Walkowska, A.

    2016-07-01

    One of the most important utility properties of medical knitted meshes intended for hernia and urological treatment is their bidirectional strength along the courses and wales. The value of this parameter, expected by the manufacturers and surgeons, is estimated at 100 N per 5 cm of the sample width. The most frequently, these meshes are produced on the basis of single- or double-guide stitches. They are made of polypropylene and polyester monofilament yarns with the diameter in the range from 0.6 to 1.2 mm, characterized by a high medical purity. The aim of the study was to develop the design methodology of meshes strength based on the geometrical construction of the stitch and strength of yarn. In the environment of the ProCAD warpknit 5 software the simulated stretching process of meshes together with an analysis of their geometry changes was carried out. Simulations were made for four selected representative stitches. Both on a built, unique measuring position and on the tensile testing machine the real parameters of the loops geometry of meshes were measured. Model of mechanical stretching of warp-knitted meshes along the courses and wales was developed. The thesis argument was made, that the force that breaks the loop of warp-knitted fabric is the lowest value of breaking forces of loop link yarns or yarns that create straight sections of loop. This thesis was associate with the theory of strength that uses the “the weakest link concept”. Experimental verification of model was carried out for the basic structure of the single-guide mesh. It has been shown that the real, relative strength of the mesh related to one course is equal to the strength of the yarn breakage in a loop, while the strength along the wales is close to breaking strength of a single yarn. In relation to the specific construction of the medical mesh, based on the knowledge of the density of the loops structure, the a-jour mesh geometry and the yarns strength, it is possible, with high

  4. Developing Risk Prediction Models for Postoperative Pancreatic Fistula: a Systematic Review of Methodology and Reporting Quality.

    PubMed

    Wen, Zhang; Guo, Ya; Xu, Banghao; Xiao, Kaiyin; Peng, Tao; Peng, Minhao

    2016-04-01

    Postoperative pancreatic fistula is still a major complication after pancreatic surgery, despite improvements of surgical technique and perioperative management. We sought to systematically review and critically access the conduct and reporting of methods used to develop risk prediction models for predicting postoperative pancreatic fistula. We conducted a systematic search of PubMed and EMBASE databases to identify articles published before January 1, 2015, which described the development of models to predict the risk of postoperative pancreatic fistula. We extracted information of developing a prediction model including study design, sample size and number of events, definition of postoperative pancreatic fistula, risk predictor selection, missing data, model-building strategies, and model performance. Seven studies of developing seven risk prediction models were included. In three studies (42 %), the number of events per variable was less than 10. The number of candidate risk predictors ranged from 9 to 32. Five studies (71 %) reported using univariate screening, which was not recommended in building a multivariate model, to reduce the number of risk predictors. Six risk prediction models (86 %) were developed by categorizing all continuous risk predictors. The treatment and handling of missing data were not mentioned in all studies. We found use of inappropriate methods that could endanger the development of model, including univariate pre-screening of variables, categorization of continuous risk predictors, and model validation. The use of inappropriate methods affects the reliability and the accuracy of the probability estimates of predicting postoperative pancreatic fistula.

  5. Empirical studies of clinical supervision in psychiatric nursing: A systematic literature review and methodological critique.

    PubMed

    Buus, Niels; Gonge, Henrik

    2009-08-01

    The objective of this paper was to systematically review and critically evaluate all English language research papers reporting empirical studies of clinical supervision in psychiatric nursing. The first part of the search strategy was a combination of brief and building block strategies in the PubMed, CINAHL, and PsycINFO databases. The second part was a citation pearl growing strategy with reviews of 179 reference lists. In total, the search strategy demonstrated a low level of precision and a high level of recall. Thirty four articles met the criteria of the review and were systematically evaluated using three checklists. The findings were summarized by using a new checklist with nine overall questions regarding the studies' design, methods, findings, and limitations. The studies were categorized as: (i) effect studies; (ii) survey studies; (iii) interview studies; and (iv) case studies. In general, the studies were relatively small scale; they used relatively new and basic methods for data collection and analysis, and rarely included sufficient strategies for identifying confounding factors or how the researchers' preconceptions influenced the analyses. Empirical research of clinical supervision in psychiatric nursing was characterized by a basic lack of agreement about which models and instruments to use. Challenges and recommendations for future research are discussed. Clinical supervision in psychiatric nursing was commonly perceived as a good thing, but there was limited empirical evidence supporting this claim.

  6. Uptake of newer methodological developments and the deployment of meta-analysis in diagnostic test research: a systematic review.

    PubMed

    Willis, Brian H; Quigley, Muireann

    2011-03-14

    The last decade has seen a number of methodological developments in meta-analysis of diagnostic test studies. However, it is unclear whether such developments have permeated the wider research community and on which applications they are being deployed. The objective was to assess the uptake and deployment of the main methodological developments in the meta-analysis of diagnostic tests, and identify the tests and target disorders most commonly evaluated by meta-analysis. Design--systematic review. Data Sources--Medline, EMBASE, CINAHL, Cochrane, PsychInfo, Global health, HMIC, and AMED were searched for studies published before 31st December 2008. Selection criteria--studies were included if they satisfied all of the following: evaluated a diagnostic test; measured test performance; searched two or more databases; stated search terms and inclusion criteria; used a statistical method to summarise performance. Data extraction--included the following data items: year; test; reference standard; target disorder; setting; statistical and quality methods. 236 studies were included. Over the last 5 years the number of meta-analyses published has increased, but the uptake of new statistical methods lags behind. Pooling the sensitivity and specificity and using the SROC remain the preferred methods for analysis in 70% of studies, with the bivariate random effects and HSROC model being used in only 22% and 5% of studies respectively. In contrast, between 2006 and 2008 the QUADAS tool was used in 40% of studies. Broadly, radiological imaging was the most frequent category of tests analysed (36%), with cancer (22%) and infection (21%) being the most common categories of target disorder. Nearly 80% of tests analysed were those normally used in specialist settings. Although quality assessment in meta-analyses has improved with the introduction of QUADAS, uptake of the newer statistical methods is still lagging behind. Furthermore, the focus of secondary research seems to be in

  7. Systematic review of the methodological quality of controlled trials evaluating Chinese herbal medicine in patients with rheumatoid arthritis

    PubMed Central

    Pan, Xin; Lopez-Olivo, Maria A; Song, Juhee; Pratt, Gregory; Suarez-Almazor, Maria E

    2017-01-01

    Objectives We appraised the methodological and reporting quality of randomised controlled clinical trials (RCTs) evaluating the efficacy and safety of Chinese herbal medicine (CHM) in patients with rheumatoid arthritis (RA). Design For this systematic review, electronic databases were searched from inception until June 2015. The search was limited to humans and non-case report studies, but was not limited by language, year of publication or type of publication. Two independent reviewers selected RCTs, evaluating CHM in RA (herbals and decoctions). Descriptive statistics were used to report on risk of bias and their adherence to reporting standards. Multivariable logistic regression analysis was performed to determine study characteristics associated with high or unclear risk of bias. Results Out of 2342 unique citations, we selected 119 RCTs including 18 919 patients: 10 108 patients received CHM alone and 6550 received one of 11 treatment combinations. A high risk of bias was observed across all domains: 21% had a high risk for selection bias (11% from sequence generation and 30% from allocation concealment), 85% for performance bias, 89% for detection bias, 4% for attrition bias and 40% for reporting bias. In multivariable analysis, fewer authors were associated with selection bias (allocation concealment), performance bias and attrition bias, and earlier year of publication and funding source not reported or disclosed were associated with selection bias (sequence generation). Studies published in non-English language were associated with reporting bias. Poor adherence to recommended reporting standards (<60% of the studies not providing sufficient information) was observed in 11 of the 23 sections evaluated. Limitations Study quality and data extraction were performed by one reviewer and cross-checked by a second reviewer. Translation to English was performed by one reviewer in 85% of the included studies. Conclusions Studies evaluating CHM often fail to

  8. [Based on evidence to establish reporting guidelines for TCM-featured acupuncture systematic reviews/Meta-analysis: a methodology discussion].

    PubMed

    Wang, Ya-Jun; Liu, Ya-Li; Yang, Ke-Hu; Guo, Yi

    2014-12-01

    Existing reporting guidelines for systematic reviews/Meta-analysis (SRs/MAs) cannot meet the requirements of clinical practice and scientific research, so based on evidence, methods and thoughts on establishing reporting guidelines for TCM-featured acupuncture systematic reviews/Meta-analysis were proposed. Through literature analysis, according to evidence-based principle, preliminary ideas on methodology of establishing reporting guidelines for TCM-featured acupuncture systematic reviews /Meta-analysis were proposed. With consensus as one main research method, it was proposed that in the consensus that was selected and established by experts, the pro- portion of Chinese scholars should be increased to fully declare the opinions of Chinese acupuncturists, and by verification of practice and application, the reporting guidelines for TCM-featured acupuncture systematic reviews/Meta-analysis can be finally made.

  9. [Principles and methodology for ecological rehabilitation and security pattern design in key project construction].

    PubMed

    Chen, Li-Ding; Lu, Yi-He; Tian, Hui-Ying; Shi, Qian

    2007-03-01

    Global ecological security becomes increasingly important with the intensive human activities. The function of ecological security is influenced by human activities, and in return, the efficiency of human activities will also be affected by the patterns of regional ecological security. Since the 1990s, China has initiated the construction of key projects "Yangtze Three Gorges Dam", "Qinghai-Tibet Railway", "West-to-East Gas Pipeline", "West-to-East Electricity Transmission" and "South-to-North Water Transfer" , etc. The interaction between these projects and regional ecological security has particularly attracted the attention of Chinese government. It is not only important for the regional environmental protection, but also of significance for the smoothly implementation of various projects aimed to develop an ecological rehabilitation system and to design a regional ecological security pattern. This paper made a systematic analysis on the types and characteristics of key project construction and their effects on the environment, and on the basis of this, brought forward the basic principles and methodology for ecological rehabilitation and security pattern design in this construction. It was considered that the following issues should be addressed in the implementation of a key project: 1) analysis and evaluation of current regional ecological environment, 2) evaluation of anthropogenic disturbances and their ecological risk, 3) regional ecological rehabilitation and security pattern design, 4) scenario analysis of environmental benefits of regional ecological security pattern, 5) re-optimization of regional ecological system framework, and 6) establishment of regional ecosystem management plan.

  10. Systematic search for major genes in schizophrenia: Methodological issues and results from chromosome 12

    SciTech Connect

    Dawson, E.; Powell, J.F.; Sham, P.

    1995-10-09

    We describe a method of systematically searching for major genes in disorders of unknown mode of inheritance, using linkage analysis. Our method is designed to minimize the probability of missing linkage due to inadequate exploration of data. We illustrate this method with the results of a search for a locus for schizophrenia on chromosome 12 using 22 highly polymorphic markers in 23 high density pedigrees. The markers span approximately 85-90% of the chromosome and are on average 9.35 cM apart. We have analysed the data using the most plausible current genetic models and allowing for the presence of genetic heterogeneity. None of the markers was supportive of linkage and the distribution of the heterogeneity statistics was in accordance with the null hypothesis. 53 refs., 2 figs., 4 tabs.

  11. A Formal Semantics for the SRI Hierarchical Program Design Methodology

    NASA Technical Reports Server (NTRS)

    Boyer, R. S.; Moore, J. S.

    1983-01-01

    A formal statement of what it means to use (a subset of) the methodology is presented. It is formally defined that some specified module exists and what it means to say that another module is paid correctly implemented on top of it. No attention is to motivation, either of the methodology or of the formal development of it. Concentration is entirely upon mathematical succinctness and precision. A discussion is presented of how to use certain INTERLISP programs which implement the formal definitions. Among these are a program which generates Floyd like verification conditions sufficient to imply the correctness of a module implementation.

  12. A Formal Semantics for the SRI Hierarchical Program Design Methodology

    NASA Technical Reports Server (NTRS)

    Boyer, R. S.; Moore, J. S.

    1983-01-01

    A formal statement of what it means to use (a subset of) the methodology is presented. It is formally defined that some specified module exists and what it means to say that another module is paid correctly implemented on top of it. No attention is to motivation, either of the methodology or of the formal development of it. Concentration is entirely upon mathematical succinctness and precision. A discussion is presented of how to use certain INTERLISP programs which implement the formal definitions. Among these are a program which generates Floyd like verification conditions sufficient to imply the correctness of a module implementation.

  13. The usefulness of systematic reviews of animal experiments for the design of preclinical and clinical studies.

    PubMed

    de Vries, Rob B M; Wever, Kimberley E; Avey, Marc T; Stephens, Martin L; Sena, Emily S; Leenaars, Marlies

    2014-01-01

    The question of how animal studies should be designed, conducted, and analyzed remains underexposed in societal debates on animal experimentation. This is not only a scientific but also a moral question. After all, if animal experiments are not appropriately designed, conducted, and analyzed, the results produced are unlikely to be reliable and the animals have in effect been wasted. In this article, we focus on one particular method to address this moral question, namely systematic reviews of previously performed animal experiments. We discuss how the design, conduct, and analysis of future (animal and human) experiments may be optimized through such systematic reviews. In particular, we illustrate how these reviews can help improve the methodological quality of animal experiments, make the choice of an animal model and the translation of animal data to the clinic more evidence-based, and implement the 3Rs. Moreover, we discuss which measures are being taken and which need to be taken in the future to ensure that systematic reviews will actually contribute to optimizing experimental design and thereby to meeting a necessary condition for making the use of animals in these experiments justified.

  14. The Usefulness of Systematic Reviews of Animal Experiments for the Design of Preclinical and Clinical Studies

    PubMed Central

    de Vries, Rob B. M.; Wever, Kimberley E.; Avey, Marc T.; Stephens, Martin L.; Sena, Emily S.; Leenaars, Marlies

    2014-01-01

    The question of how animal studies should be designed, conducted, and analyzed remains underexposed in societal debates on animal experimentation. This is not only a scientific but also a moral question. After all, if animal experiments are not appropriately designed, conducted, and analyzed, the results produced are unlikely to be reliable and the animals have in effect been wasted. In this article, we focus on one particular method to address this moral question, namely systematic reviews of previously performed animal experiments. We discuss how the design, conduct, and analysis of future (animal and human) experiments may be optimized through such systematic reviews. In particular, we illustrate how these reviews can help improve the methodological quality of animal experiments, make the choice of an animal model and the translation of animal data to the clinic more evidence-based, and implement the 3Rs. Moreover, we discuss which measures are being taken and which need to be taken in the future to ensure that systematic reviews will actually contribute to optimizing experimental design and thereby to meeting a necessary condition for making the use of animals in these experiments justified. PMID:25541545

  15. Staffing by Design: A Methodology for Staffing Reference

    ERIC Educational Resources Information Center

    Ward, David; Phetteplace, Eric

    2012-01-01

    The growth in number and kind of online reference services has resulted in both new users consulting library research services as well as new patterns of service use. Staffing in-person and virtual reference services desks adequately requires a systematic analysis of patterns of use across service points in order to successfully meet fluctuating…

  16. Staffing by Design: A Methodology for Staffing Reference

    ERIC Educational Resources Information Center

    Ward, David; Phetteplace, Eric

    2012-01-01

    The growth in number and kind of online reference services has resulted in both new users consulting library research services as well as new patterns of service use. Staffing in-person and virtual reference services desks adequately requires a systematic analysis of patterns of use across service points in order to successfully meet fluctuating…

  17. Author-paper affiliation network architecture influences the methodological quality of systematic reviews and meta-analyses of psoriasis.

    PubMed

    Sanz-Cabanillas, Juan Luis; Ruano, Juan; Gomez-Garcia, Francisco; Alcalde-Mellado, Patricia; Gay-Mimbrera, Jesus; Aguilar-Luque, Macarena; Maestre-Lopez, Beatriz; Gonzalez-Padilla, Marcelino; Carmona-Fernandez, Pedro J; Velez Garcia-Nieto, Antonio; Isla-Tejera, Beatriz

    2017-01-01

    Moderate-to-severe psoriasis is associated with significant comorbidity, an impaired quality of life, and increased medical costs, including those associated with treatments. Systematic reviews (SRs) and meta-analyses (MAs) of randomized clinical trials are considered two of the best approaches to the summarization of high-quality evidence. However, methodological bias can reduce the validity of conclusions from these types of studies and subsequently impair the quality of decision making. As co-authorship is among the most well-documented forms of research collaboration, the present study aimed to explore whether authors' collaboration methods might influence the methodological quality of SRs and MAs of psoriasis. Methodological quality was assessed by two raters who extracted information from full articles. After calculating total and per-item Assessment of Multiple Systematic Reviews (AMSTAR) scores, reviews were classified as low (0-4), medium (5-8), or high (9-11) quality. Article metadata and journal-related bibliometric indices were also obtained. A total of 741 authors from 520 different institutions and 32 countries published 220 reviews that were classified as high (17.2%), moderate (55%), or low (27.7%) methodological quality. The high methodological quality subnetwork was larger but had a lower connection density than the low and moderate methodological quality subnetworks; specifically, the former contained relatively fewer nodes (authors and reviews), reviews by authors, and collaborators per author. Furthermore, the high methodological quality subnetwork was highly compartmentalized, with several modules representing few poorly interconnected communities. In conclusion, structural differences in author-paper affiliation network may influence the methodological quality of SRs and MAs on psoriasis. As the author-paper affiliation network structure affects study quality in this research field, authors who maintain an appropriate balance between

  18. Integrated Controls-Structures Design Methodology for Flexible Spacecraft

    NASA Technical Reports Server (NTRS)

    Maghami, P. G.; Joshi, S. M.; Price, D. B.

    1995-01-01

    This paper proposes an approach for the design of flexible spacecraft, wherein the structural design and the control system design are performed simultaneously. The integrated design problem is posed as an optimization problem in which both the structural parameters and the control system parameters constitute the design variables, which are used to optimize a common objective function, thereby resulting in an optimal overall design. The approach is demonstrated by application to the integrated design of a geostationary platform, and to a ground-based flexible structure experiment. The numerical results obtained indicate that the integrated design approach generally yields spacecraft designs that are substantially superior to the conventional approach, wherein the structural design and control design are performed sequentially.

  19. Peer Review of a Formal Verification/Design Proof Methodology

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The role of formal verification techniques in system validation was examined. The value and the state of the art of performance proving for fault-tolerant compuers were assessed. The investigation, development, and evaluation of performance proving tools were reviewed. The technical issues related to proof methodologies are examined. The technical issues discussed are summarized.

  20. Loss Exposure and Risk Analysis Methodology (LERAM) Project Database Design.

    DTIC Science & Technology

    1996-06-01

    MISREPS) to more capably support system safety engineering concepts such as hazard analysis and risk management. As part of the Loss Exposure and Risk ... Analysis Methodology (LERAM) project, the research into the methods which we employ to report, track, and analyze hazards has resulted in a series of low

  1. Behavioral Methodology for Designing and Evaluating Applied Programs for Women.

    ERIC Educational Resources Information Center

    Thurston, Linda P.

    To be maximally effective in solving problems, researchers must place their methodological and theoretical models of science within social and political contexts. They must become aware of biases and assumptions and move toward a more valid perception of social realities. Psychologists must view women in the situational context within which…

  2. De/signing Research in Education: Patchwork(ing) Methodologies with Theory

    ERIC Educational Resources Information Center

    Higgins, Marc; Madden, Brooke; Berard, Marie-France; Lenz Kothe, Elsa; Nordstrom, Susan

    2017-01-01

    Four education scholars extend the methodological space inspired by Jackson and Mazzei's "Thinking with Theory" through focusing on research design. The notion of de/sign is presented and employed to counter prescriptive method/ology that often sutures over pedagogical possibilities in research and educational settings. Key…

  3. Methodology for designing accelerated aging tests for predicting life of photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Gaines, G. B.; Thomas, R. E.; Derringer, G. C.; Kistler, C. W.; Bigg, D. M.; Carmichael, D. C.

    1977-01-01

    A methodology for designing aging tests in which life prediction was paramount was developed. The methodology builds upon experience with regard to aging behavior in those material classes which are expected to be utilized as encapsulant elements, viz., glasses and polymers, and upon experience with the design of aging tests. The experiences were reviewed, and results are discussed in detail.

  4. De/signing Research in Education: Patchwork(ing) Methodologies with Theory

    ERIC Educational Resources Information Center

    Higgins, Marc; Madden, Brooke; Berard, Marie-France; Lenz Kothe, Elsa; Nordstrom, Susan

    2017-01-01

    Four education scholars extend the methodological space inspired by Jackson and Mazzei's "Thinking with Theory" through focusing on research design. The notion of de/sign is presented and employed to counter prescriptive method/ology that often sutures over pedagogical possibilities in research and educational settings. Key…

  5. Establishing Equivalence: Methodological Progress in Group-Matching Design and Analysis

    ERIC Educational Resources Information Center

    Kover, Sara T.; Atwood, Amy K.

    2013-01-01

    This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs used in behavioral research on cognition and…

  6. Establishing Equivalence: Methodological Progress in Group-Matching Design and Analysis

    ERIC Educational Resources Information Center

    Kover, Sara T.; Atwood, Amy K.

    2013-01-01

    This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs used in behavioral research on cognition and…

  7. Methodology of Computer-Aided Design of Variable Guide Vanes of Aircraft Engines

    ERIC Educational Resources Information Center

    Falaleev, Sergei V.; Melentjev, Vladimir S.; Gvozdev, Alexander S.

    2016-01-01

    The paper presents a methodology which helps to avoid a great amount of costly experimental research. This methodology includes thermo-gas dynamic design of an engine and its mounts, the profiling of compressor flow path and cascade design of guide vanes. Employing a method elaborated by Howell, we provide a theoretical solution to the task of…

  8. 77 FR 50514 - Post-Approval Studies 2012 Workshop: Design, Methodology, and Role in Evidence Appraisal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... experiences with post- approval studies, improvement of implementation strategies for post- approval studies... HUMAN SERVICES Food and Drug Administration Post-Approval Studies 2012 Workshop: Design, Methodology... ``Post-Approval Studies 2012 Workshop: Design, Methodology, and Role in Evidence Appraisal Throughout the...

  9. Game Methodology for Design Methods and Tools Selection

    ERIC Educational Resources Information Center

    Ahmad, Rafiq; Lahonde, Nathalie; Omhover, Jean-françois

    2014-01-01

    Design process optimisation and intelligence are the key words of today's scientific community. A proliferation of methods has made design a convoluted area. Designers are usually afraid of selecting one method/tool over another and even expert designers may not necessarily know which method is the best to use in which circumstances. This…

  10. Effectiveness and efficacy of nutritional therapy: A systematic review following Cochrane methodology.

    PubMed

    Muscaritoli, Maurizio; Krznarić, Zeljko; Singer, Pierre; Barazzoni, Rocco; Cederholm, Tommy; Golay, Alain; Van Gossum, André; Kennedy, Nicholas; Kreymann, Georg; Laviano, Alessandro; Pavić, Tajana; Puljak, Livia; Sambunjak, Dario; Utrobičić, Ana; Schneider, Stéphane M

    2017-08-01

    Disease-related malnutrition has deleterious consequences on patients' outcome and healthcare costs. The demonstration of improved outcome by appropriate nutritional management is on occasion difficult. The European Society of Clinical Nutrition and Metabolism (ESPEN) appointed the Nutrition Education Study Group (ESPEN-NESG) to increase recognition of nutritional knowledge and support in health services. To obtain the best available evidence on the potential effects of malnutrition on morbidity, mortality and hospital stay; cost of malnutrition; effect of nutritional treatment on outcome parameters and pharmaco-economics of nutritional therapy, a systematic review of the literature was performed following Cochrane methodology, to answer the following key questions: Q1) Is malnutrition an independent predictive factor for readmission within 30 days from hospital discharge? Q2) Does nutritional therapy reduce the risk of readmission within 30 days from hospital discharge? Q3) Is nutritional therapy cost-effective/does it reduce costs in hospitalized patients? and Q4) Is nutritional therapy cost effective/does it reduce costs in outpatients? For Q1 six of 15 identified observational studies indicated that malnutrition was predictive of re-admissions, whereas the remainder did not. For Q2 nine randomized controlled trials and two meta-analyses gave non-conclusive results whether re-admissions could be reduced by nutritional therapy. Economic benefit and cost-effectiveness of nutritional therapy was consistently reported in 16 identified studies for hospitalized patients (Q3), whereas the heterogeneous and limited corresponding data on out-patients (Q4) indicated cost-benefits in some selected sub-groups. This result of this review supports the use of nutritional therapy to reduce healthcare costs, most evident from large, homogeneous studies. In general, reports are too heterogeneous and overall of limited quality for conclusions on impact of malnutrition and its

  11. Variable methodological quality and use found in systematic reviews referenced in STEMI clinical practice guidelines.

    PubMed

    Scott, Jared; Howard, Benjamin; Sinnett, Philip; Schiesel, Michael; Baker, Jana; Henderson, Patrick; Vassar, Matt

    2017-06-14

    The objective of this study was to assess the methodological quality and clarity of reporting of the systematic reviews (SRs) supporting clinical practice guideline (CPG) recommendations in the management of ST-elevation myocardial infarction (STEMI) across international CPGs. We searched 13 guideline clearinghouses including the National Guideline Clearinghouse and Guidelines International Network (GIN). To meet inclusion criteria CPGs must be pertinent to the management of STEMI, endorsed by a governing body or national organization, and written in English. We retrieved SRs from the reference sections using a combination of keywords and hand searching. Two investigators scored eligible SRs using AMSTAR and PRISMA. We included four CPGs. We extracted 71 unique SRs. These SRs received AMSTAR scores ranging from 1 (low) to 9 (high) on an 11-point scale. All CPGs consistently underperformed in areas including disclosure of funding sources, risk of bias, and publication bias according to AMSTAR. PRISMA checklist completeness ranged from 44% to 96%. The PRISMA scores indicated that SRs did not provide a full search strategy, study protocol and registration, assessment of publication bias or report funding sources. Only one SR was referenced in all four CPGs. All CPGs omitted a large subset of available SRs cited by other guidelines. Our study demonstrates the variable quality of SRs used to establish recommendations within guidelines included in our sample. Although guideline developers have acknowledged this variability, it remains a significant finding that needs to be addressed further. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Designing directories in distributed systems: A systematic framework

    SciTech Connect

    Chandy, K.M.; Schooler, E.M.

    1996-12-31

    This paper proposes a framework for the systematic design of directory-based distributed applications. We evaluate a space of directory designs using our framework. We present a case study consisting of design, implementation and analysis of directories for a multicast application. Our framework is based on a model that extends the formal concept of process knowledge in distributed systems. This concept is used informally in phrases such as {open_quotes}process p knows when it is in state s that process q is active.{close_quotes} We show that this definition of knowledge is too strong for many distributed applications, including directory design. We propose a weaker concept: estimation. We describe the meaning of phrases of the form: {open_quotes}process p in state s estimates with probability 0.9 that process q is active.{close_quotes} We specify directory design as an optimization problem with the objective function of maximizing estimation probabilities, and with constraints on the amount of bandwidth, computation and storage used. We show how this specification helps in a systematic analysis of alternative directory designs.

  13. Response surface methodology and process optimization of sustained release pellets using Taguchi orthogonal array design and central composite design.

    PubMed

    Singh, Gurinder; Pai, Roopa S; Devi, V Kusum

    2012-01-01

    Furosemide is a powerful diuretic and antihypertensive drug which has low bioavailability due to hepatic first pass metabolism and has a short half-life of 2 hours. To overcome the above drawback, the present study was carried out to formulate and evaluate sustained release (SR) pellets of furosemide for oral administration prepared by extrusion/spheronization. Drug Coat L-100 was used within the pellet core along with microcrystalline cellulose as the diluent and concentration of selected binder was optimized to be 1.2%. The formulation was prepared with drug to polymer ratio 1:3. It was optimized using Design of Experiments by employing a 3(2) central composite design that was used to systematically optimize the process parameters combined with response surface methodology. Dissolution studies were carried out with USP apparatus Type I (basket type) in both simulated gastric and intestinal pH. The statistical technique, i.e., the two-tailed paired t test and one-way ANOVA of in vitro data has proposed that there was very significant (P≤0.05) difference in dissolution profile of furosemide SR pellets when compared with pure drug and commercial product. Validation of the process optimization study indicated an extremely high degree of prognostic ability. The study effectively undertook the development of optimized process parameters of pelletization of furosemide pellets with tremendous SR characteristics.

  14. Response surface methodology and process optimization of sustained release pellets using Taguchi orthogonal array design and central composite design

    PubMed Central

    Singh, Gurinder; Pai, Roopa S.; Devi, V. Kusum

    2012-01-01

    Furosemide is a powerful diuretic and antihypertensive drug which has low bioavailability due to hepatic first pass metabolism and has a short half-life of 2 hours. To overcome the above drawback, the present study was carried out to formulate and evaluate sustained release (SR) pellets of furosemide for oral administration prepared by extrusion/spheronization. Drug Coat L-100 was used within the pellet core along with microcrystalline cellulose as the diluent and concentration of selected binder was optimized to be 1.2%. The formulation was prepared with drug to polymer ratio 1:3. It was optimized using Design of Experiments by employing a 32 central composite design that was used to systematically optimize the process parameters combined with response surface methodology. Dissolution studies were carried out with USP apparatus Type I (basket type) in both simulated gastric and intestinal pH. The statistical technique, i.e., the two-tailed paired t test and one-way ANOVA of in vitro data has proposed that there was very significant (P≤0.05) difference in dissolution profile of furosemide SR pellets when compared with pure drug and commercial product. Validation of the process optimization study indicated an extremely high degree of prognostic ability. The study effectively undertook the development of optimized process parameters of pelletization of furosemide pellets with tremendous SR characteristics. PMID:22470891

  15. Design of a methodology for assessing an electrocardiographic telemonitoring system.

    PubMed

    Alfonzo, A; Huerta, M K; Wong, S; Passariello, G; Díaz, M; La Cruz, A; Cruz, J

    2007-01-01

    Recent studies in Bioengineering show a great interest in telemedicine projects, it is motivated mainly for the fast communication technologies reached during the last decade. Since then many telemedicine projects in different areas have been pursued, among them the electrocardiographic monitoring, as well as methodological reports for the evaluation of these projects. In this work a methodology to evaluate an electrocardiographic telemonitoring system is presented. A procedure to verify the operation of Data Acquisition Module (DAM) of an electrocardiographic telemonitoring system is given, taking as reference defined standards, and procedures for the measurement of the Quality of Service (QoS) parameters required by the system in a Local Area Network (LAN). Finally a graphical model and protocols of evaluation are proposed.

  16. ‘Spin’ in published biomedical literature: A methodological systematic review

    PubMed Central

    Chiu, Kellia; Grundy, Quinn

    2017-01-01

    In the scientific literature, spin refers to reporting practices that distort the interpretation of results and mislead readers so that results are viewed in a more favourable light. The presence of spin in biomedical research can negatively impact the development of further studies, clinical practice, and health policies. This systematic review aims to explore the nature and prevalence of spin in the biomedical literature. We searched MEDLINE, PreMEDLINE, Embase, Scopus, and hand searched reference lists for all reports that included the measurement of spin in the biomedical literature for at least 1 outcome. Two independent coders extracted data on the characteristics of reports and their included studies and all spin-related outcomes. Results were grouped inductively into themes by spin-related outcome and are presented as a narrative synthesis. We used meta-analyses to analyse the association of spin with industry sponsorship of research. We included 35 reports, which investigated spin in clinical trials, observational studies, diagnostic accuracy studies, systematic reviews, and meta-analyses. The nature of spin varied according to study design. The highest (but also greatest) variability in the prevalence of spin was present in trials. Some of the common practices used to spin results included detracting from statistically nonsignificant results and inappropriately using causal language. Source of funding was hypothesised by a few authors to be a factor associated with spin; however, results were inconclusive, possibly due to the heterogeneity of the included papers. Further research is needed to assess the impact of spin on readers’ decision-making. Editors and peer reviewers should be familiar with the prevalence and manifestations of spin in their area of research in order to ensure accurate interpretation and dissemination of research. PMID:28892482

  17. A Rapid Python-Based Methodology for Target-Focused Combinatorial Library Design.

    PubMed

    Li, Shiliang; Song, Yuwei; Liu, Xiaofeng; Li, Honglin

    2016-01-01

    The chemical space is so vast that only a small portion of it has been examined. As a complementary approach to systematically probe the chemical space, virtual combinatorial library design has extended enormous impacts on generating novel and diverse structures for drug discovery. Despite the favorable contributions, high attrition rates in drug development that mainly resulted from lack of efficacy and side effects make it increasingly challenging to discover good chemical starting points. In most cases, focused libraries, which are restricted to particular regions of the chemical space, are deftly exploited to maximize hit rate and improve efficiency at the beginning of the drug discovery and drug development pipeline. This paper presented a valid methodology for fast target-focused combinatorial library design in both reaction-based and production-based ways with the library creating rates of approximately 70,000 molecules per second. Simple, quick and convenient operating procedures are the specific features of the method. SHAFTS, a hybrid 3D similarity calculation software, was embedded to help refine the size of the libraries and improve hit rates. Two target-focused (p38-focused and COX2-focused) libraries were constructed efficiently in this study. This rapid library enumeration method is portable and applicable to any other targets for good chemical starting points identification collaborated with either structure-based or ligand-based virtual screening.

  18. Design methodology for optimal hardware implementation of wavelet transform domain algorithms

    NASA Astrophysics Data System (ADS)

    Johnson-Bey, Charles; Mickens, Lisa P.

    2005-05-01

    The work presented in this paper lays the foundation for the development of an end-to-end system design methodology for implementing wavelet domain image/video processing algorithms in hardware using Xilinx field programmable gate arrays (FPGAs). With the integration of the Xilinx System Generator toolbox, this methodology will allow algorithm developers to design and implement their code using the familiar MATLAB/Simulink development environment. By using this methodology, algorithm developers will not be required to become proficient in the intricacies of hardware design, thus reducing the design cycle and time-to-market.

  19. A Design Methodology for Complex (E)-Learning. Innovative Session.

    ERIC Educational Resources Information Center

    Bastiaens, Theo; van Merrienboer, Jeroen; Hoogveld, Bert

    Human resource development (HRD) specialists are searching for instructional design models that accommodate e-learning platforms. Van Merrienboer proposed the four-component instructional design model (4C/ID model) for competency-based education. The model's basic message is that well-designed learning environments can always be described in terms…

  20. Ethics of Engagement: User-Centered Design and Rhetorical Methodology.

    ERIC Educational Resources Information Center

    Salvo, Michael J.

    2001-01-01

    Explores the shift from observation of users to participation with users, describing and investigating three examples of user-centered design practice in order to consider the new ethical demands being made of technical communicators. Explores Pelle Ehn's participatory design method, Roger Whitehouse's design of tactile signage for blind users,…

  1. Methodological quality evaluation of systematic reviews or meta-analyses on ERCC1 in non-small cell lung cancer: a systematic review.

    PubMed

    Tao, Huan; Zhang, Yueyuan; Li, Qian; Chen, Jin

    2017-09-05

    To assess the methodological quality of systematic reviews (SRs) or meta-analysis concerning the predictive value of ERCC1 in platinum chemotherapy of non-small cell lung cancer. We searched the PubMed, EMbase, Cochrane library, international prospective register of systematic reviews, Chinese BioMedical Literature Database, China National Knowledge Infrastructure, Wan Fang and VIP database for SRs or meta-analysis. The methodological quality of included literatures was evaluated by risk of bias in systematic review (ROBIS) scale. Nineteen eligible SRs/meta-analysis were included. The most frequently searched databases were EMbase (74%), PubMed, Medline and CNKI. Fifteen SRs did additional retrieval manually, but none of them retrieved the registration platform. 47% described the two-reviewers model in the screening for eligible original articles, and seven SRs described the two reviewers to extract data. In methodological quality assessment, inter-rater reliability Kappa was 0.87 between two reviewers. Research question were well related to all SRs in phase 1 and the eligibility criteria was suitable for each SR, and rated as 'low' risk bias. But the 'high' risk bias existed in all the SRs regarding methods used to identify and/or select studies, and data collection and study appraisal. More than two-third of SRs or meta-analysis were finished with high risk of bias in the synthesis, findings and the final phase. The study demonstrated poor methodological quality of SRs/meta-analysis assessing the predictive value of ERCC1 in chemotherapy among the NSCLC patients, especially the high performance bias. Registration or publishing the protocol is recommended in future research.

  2. A transonic-small-disturbance wing design methodology

    NASA Technical Reports Server (NTRS)

    Phillips, Pamela S.; Waggoner, Edgar G.; Campbell, Richard L.

    1988-01-01

    An automated transonic design code has been developed which modifies an initial airfoil or wing in order to generate a specified pressure distribution. The design method uses an iterative approach that alternates between a potential-flow analysis and a design algorithm that relates changes in surface pressure to changes in geometry. The analysis code solves an extended small-disturbance potential-flow equation and can model a fuselage, pylons, nacelles, and a winglet in addition to the wing. A two-dimensional option is available for airfoil analysis and design. Several two- and three-dimensional test cases illustrate the capabilities of the design code.

  3. Methodologic quality of meta-analyses and systematic reviews on the Mediterranean diet and cardiovascular disease outcomes: a review.

    PubMed

    Huedo-Medina, Tania B; Garcia, Marissa; Bihuniak, Jessica D; Kenny, Anne; Kerstetter, Jane

    2016-03-01

    Several systematic reviews/meta-analyses published within the past 10 y have examined the associations of Mediterranean-style diets (MedSDs) on cardiovascular disease (CVD) risk. However, these reviews have not been evaluated for satisfying contemporary methodologic quality standards. This study evaluated the quality of recent systematic reviews/meta-analyses on MedSD and CVD risk outcomes by using an established methodologic quality scale. The relation between review quality and impact per publication value of the journal in which the article had been published was also evaluated. To assess compliance with current standards, we applied a modified version of the Assessment of Multiple Systematic Reviews (AMSTARMedSD) quality scale to systematic reviews/meta-analyses retrieved from electronic databases that had met our selection criteria: 1) used systematic or meta-analytic procedures to review the literature, 2) examined MedSD trials, and 3) had MedSD interventions independently or combined with other interventions. Reviews completely satisfied from 8% to 75% of the AMSTARMedSD items (mean ± SD: 31.2% ± 19.4%), with those published in higher-impact journals having greater quality scores. At a minimum, 60% of the 24 reviews did not disclose full search details or apply appropriate statistical methods to combine study findings. Only 5 of the reviews included participant or study characteristics in their analyses, and none evaluated MedSD diet characteristics. These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on CVD risk do not fully comply with contemporary methodologic quality standards. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects CVD risk or how these effects may be modified by the participant or MedSD characteristics. To clarify the associations between MedSD and CVD risk, future meta-analyses and systematic reviews should not only follow methodologic

  4. The Navigation Guide Systematic Review Methodology: A Rigorous and Transparent Method for Translating Environmental Health Science into Better Health Outcomes

    PubMed Central

    Sutton, Patrice

    2014-01-01

    Background: Synthesizing what is known about the environmental drivers of health is instrumental to taking prevention-oriented action. Methods of research synthesis commonly used in environmental health lag behind systematic review methods developed in the clinical sciences over the past 20 years. Objectives: We sought to develop a proof of concept of the “Navigation Guide,” a systematic and transparent method of research synthesis in environmental health. Discussion: The Navigation Guide methodology builds on best practices in research synthesis in evidence-based medicine and environmental health. Key points of departure from current methods of expert-based narrative review prevalent in environmental health include a prespecified protocol, standardized and transparent documentation including expert judgment, a comprehensive search strategy, assessment of “risk of bias,” and separation of the science from values and preferences. Key points of departure from evidence-based medicine include assigning a “moderate” quality rating to human observational studies and combining diverse evidence streams. Conclusions: The Navigation Guide methodology is a systematic and rigorous approach to research synthesis that has been developed to reduce bias and maximize transparency in the evaluation of environmental health information. Although novel aspects of the method will require further development and validation, our findings demonstrated that improved methods of research synthesis under development at the National Toxicology Program and under consideration by the U.S. Environmental Protection Agency are fully achievable. The institutionalization of robust methods of systematic and transparent review would provide a concrete mechanism for linking science to timely action to prevent harm. Citation: Woodruff TJ, Sutton P. 2014. The Navigation Guide systematic review methodology: a rigorous and transparent method for translating environmental health science into

  5. Aerospace structural design process improvement using systematic evolutionary structural modeling

    NASA Astrophysics Data System (ADS)

    Taylor, Robert Michael

    2000-10-01

    A multidisciplinary team tasked with an aircraft design problem must understand the problem requirements and metrics to produce a successful design. This understanding entails not only knowledge of what these requirements and metrics are, but also how they interact, which are most important (to the customer as well as to aircraft performance), and who in the organization can provide pertinent knowledge for each. In recent years, product development researchers and organizations have developed and successfully applied a variety of tools such as Quality Function Deployment (QFD) to coordinate multidisciplinary team members. The effectiveness of these methods, however, depends on the quality and fidelity of the information that team members can input. In conceptual aircraft design, structural information is of lower quality compared to aerodynamics or performance because it is based on experience rather than theory. This dissertation shows how advanced structural design tools can be used in a multidisciplinary team setting to improve structural information generation and communication through a systematic evolution of structural detail. When applied to conceptual design, finite element-based structural design tools elevate structural information to the same level as other computationally supported disciplines. This improved ability to generate and communicate structural information enables a design team to better identify and meet structural design requirements, consider producibility issues earlier, and evaluate structural concepts. A design process experiment of a wing structural layout in collaboration with an industrial partner illustrates and validates the approach.

  6. Design Features of Explicit Values Clarification Methods: A Systematic Review.

    PubMed

    Witteman, Holly O; Scherer, Laura D; Gavaruzzi, Teresa; Pieterse, Arwen H; Fuhrel-Forbis, Andrea; Chipenda Dansokho, Selma; Exe, Nicole; Kahn, Valerie C; Feldman-Stewart, Deb; Col, Nananda F; Turgeon, Alexis F; Fagerlin, Angela

    2016-05-01

    Values clarification is a recommended element of patient decision aids. Many different values clarification methods exist, but there is little evidence synthesis available to guide design decisions. To describe practices in the field of explicit values clarification methods according to a taxonomy of design features. MEDLINE, all EBM Reviews, CINAHL, EMBASE, Google Scholar, manual search of reference lists, and expert contacts. Articles were included if they described 1 or more explicit values clarification methods. We extracted data about decisions addressed; use of theories, frameworks, and guidelines; and 12 design features. We identified 110 articles describing 98 explicit values clarification methods. Most of these addressed decisions in cancer or reproductive health, and half addressed a decision between just 2 options. Most used neither theory nor guidelines to structure their design. "Pros and cons" was the most common type of values clarification method. Most methods did not allow users to add their own concerns. Few methods explicitly presented tradeoffs inherent in the decision, supported an iterative process of values exploration, or showed how different options aligned with users' values. Study selection criteria and choice of elements for the taxonomy may have excluded values clarification methods or design features. Explicit values clarification methods have diverse designs but can be systematically cataloged within the structure of a taxonomy. Developers of values clarification methods should carefully consider each of the design features in this taxonomy and publish adequate descriptions of their designs. More research is needed to study the effects of different design features. © The Author(s) 2016.

  7. Drift design methodology and preliminary application for the Yucca Mountain Site Characterization Project; Yucca Mountain Site Characterization Project

    SciTech Connect

    Hardy, M.P.; Bauer, S.J.

    1991-12-01

    Excavation stability in an underground nuclear waste repository is required during construction, emplacement, retrieval (if required), and closure phases to ensure worker health and safety, and to prevent development of potential pathways for radionuclide migration in the post-closure period. Stable excavations are developed by appropriate excavation procedures, design of the room shape, design and installation of rock support reinforcement systems, and implementation of appropriate monitoring and maintenance programs. In addition to the loads imposed by the in situ stress field, the repository drifts will be impacted by thermal loads developed after waste emplacement and, periodically, by seismic loads from naturally occurring earthquakes and underground nuclear events. A priori evaluation of stability is required for design of the ground support system, to confirm that the thermal loads are reasonable, and to support the license application process. In this report, a design methodology for assessing drift stability is presented. This is based on site conditions, together with empirical and analytical methods. Analytical numerical methods are emphasized at this time because empirical data are unavailable for excavations in welded tuff either at elevated temperatures or under seismic loads. The analytical methodology incorporates analysis of rock masses that are systematically jointed, randomly jointed, and sparsely jointed. In situ thermal and seismic loads are considered. Methods of evaluating the analytical results and estimating ground support requirements for all the full range of expected ground conditions are outlines. The results of a preliminary application of the methodology using the limited available data are presented. 26 figs., 55 tabs.

  8. Propulsion integration of hypersonic air-breathing vehicles utilizing a top-down design methodology

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Brad Kenneth

    In recent years, a focus of aerospace engineering design has been the development of advanced design methodologies and frameworks to account for increasingly complex and integrated vehicles. Techniques such as parametric modeling, global vehicle analyses, and interdisciplinary data sharing have been employed in an attempt to improve the design process. The purpose of this study is to introduce a new approach to integrated vehicle design known as the top-down design methodology. In the top-down design methodology, the main idea is to relate design changes on the vehicle system and sub-system level to a set of over-arching performance and customer requirements. Rather than focusing on the performance of an individual system, the system is analyzed in terms of the net effect it has on the overall vehicle and other vehicle systems. This detailed level of analysis can only be accomplished through the use of high fidelity computational tools such as Computational Fluid Dynamics (CFD) or Finite Element Analysis (FEA). The utility of the top-down design methodology is investigated through its application to the conceptual and preliminary design of a long-range hypersonic air-breathing vehicle for a hypothetical next generation hypersonic vehicle (NHRV) program. System-level design is demonstrated through the development of the nozzle section of the propulsion system. From this demonstration of the methodology, conclusions are made about the benefits, drawbacks, and cost of using the methodology.

  9. A Comparison of Angoff's Design I and Design II for Vertical Equating Using Traditional and IRT Methodology.

    ERIC Educational Resources Information Center

    Harris, Deborah J.

    1991-01-01

    Two data collection designs, counterbalanced and spiraling (Angoff's Design I and Angoff's Design II) were compared using item response theory and equipercentile equating methodology in the vertical equating of 2 mathematics achievement tests using 1,000 eleventh graders and 1,000 twelfth graders. The greater stability of Design II is discussed.…

  10. Toward More Effective Microcomputer Courseware through Application of Systematic Instructional Design Methods.

    ERIC Educational Resources Information Center

    Roblyer, M. D.

    1983-01-01

    Discusses some reasons courseware developers have not embraced the systematic approach to microcomputer courseware design and describes ways systematic design could have a positive impact on courseware acceptance in classrooms. Twenty-two references are listed. (MBR)

  11. Toward More Effective Microcomputer Courseware through Application of Systematic Instructional Design Methods.

    ERIC Educational Resources Information Center

    Roblyer, M. D.

    1983-01-01

    Discusses some reasons courseware developers have not embraced the systematic approach to microcomputer courseware design and describes ways systematic design could have a positive impact on courseware acceptance in classrooms. Twenty-two references are listed. (MBR)

  12. A Methodology for Quantifying Certain Design Requirements During the Design Phase

    NASA Technical Reports Server (NTRS)

    Adams, Timothy; Rhodes, Russel

    2005-01-01

    A methodology for developing and balancing quantitative design requirements for safety, reliability, and maintainability has been proposed. Conceived as the basis of a more rational approach to the design of spacecraft, the methodology would also be applicable to the design of automobiles, washing machines, television receivers, or almost any other commercial product. Heretofore, it has been common practice to start by determining the requirements for reliability of elements of a spacecraft or other system to ensure a given design life for the system. Next, safety requirements are determined by assessing the total reliability of the system and adding redundant components and subsystems necessary to attain safety goals. As thus described, common practice leaves the maintainability burden to fall to chance; therefore, there is no control of recurring costs or of the responsiveness of the system. The means that have been used in assessing maintainability have been oriented toward determining the logistical sparing of components so that the components are available when needed. The process established for developing and balancing quantitative requirements for safety (S), reliability (R), and maintainability (M) derives and integrates NASA s top-level safety requirements and the controls needed to obtain program key objectives for safety and recurring cost (see figure). Being quantitative, the process conveniently uses common mathematical models. Even though the process is shown as being worked from the top down, it can also be worked from the bottom up. This process uses three math models: (1) the binomial distribution (greaterthan- or-equal-to case), (2) reliability for a series system, and (3) the Poisson distribution (less-than-or-equal-to case). The zero-fail case for the binomial distribution approximates the commonly known exponential distribution or "constant failure rate" distribution. Either model can be used. The binomial distribution was selected for

  13. Designing trials for pressure ulcer risk assessment research: methodological challenges.

    PubMed

    Balzer, K; Köpke, S; Lühmann, D; Haastert, B; Kottner, J; Meyer, G

    2013-08-01

    For decades various pressure ulcer risk assessment scales (PURAS) have been developed and implemented into nursing practice despite uncertainty whether use of these tools helps to prevent pressure ulcers. According to current methodological standards, randomised controlled trials (RCTs) are required to conclusively determine the clinical efficacy and safety of this risk assessment strategy. In these trials, PURAS-aided risk assessment has to be compared to nurses' clinical judgment alone in terms of its impact on pressure ulcer incidence and adverse outcomes. However, RCTs evaluating diagnostic procedures are prone to specific risks of bias and threats to the statistical power which may challenge their validity and feasibility. This discussion paper critically reflects on the rigour and feasibility of experimental research needed to substantiate the clinical efficacy of PURAS-aided risk assessment. Based on reflections of the methodological literature, a critical appraisal of available trials on this subject and an analysis of a protocol developed for a methodologically robust cluster-RCT, this paper arrives at the following conclusions: First, available trials do not provide reliable estimates of the impact of PURAS-aided risk assessment on pressure ulcer incidence compared to nurses' clinical judgement alone due to serious risks of bias and insufficient sample size. Second, it seems infeasible to assess this impact by means of rigorous experimental studies since sample size would become extremely high if likely threats to validity and power are properly taken into account. Third, means of evidence linkages seem to currently be the most promising approaches for evaluating the clinical efficacy and safety of PURAS-aided risk assessment. With this kind of secondary research, the downstream effect of use of PURAS on pressure ulcer incidence could be modelled by combining best available evidence for single parts of this pathway. However, to yield reliable modelling

  14. Optimal color design of psychological counseling room by design of experiments and response surface methodology.

    PubMed

    Liu, Wenjuan; Ji, Jianlin; Chen, Hua; Ye, Chenyu

    2014-01-01

    Color is one of the most powerful aspects of a psychological counseling environment. Little scientific research has been conducted on color design and much of the existing literature is based on observational studies. Using design of experiments and response surface methodology, this paper proposes an optimal color design approach for transforming patients' perception into color elements. Six indices, pleasant-unpleasant, interesting-uninteresting, exciting-boring, relaxing-distressing, safe-fearful, and active-inactive, were used to assess patients' impression. A total of 75 patients participated, including 42 for Experiment 1 and 33 for Experiment 2. 27 representative color samples were designed in Experiment 1, and the color sample (L = 75, a = 0, b = -60) was the most preferred one. In Experiment 2, this color sample was set as the 'central point', and three color attributes were optimized to maximize the patients' satisfaction. The experimental results show that the proposed method can get the optimal solution for color design of a counseling room.

  15. Optimal Color Design of Psychological Counseling Room by Design of Experiments and Response Surface Methodology

    PubMed Central

    Chen, Hua; Ye, Chenyu

    2014-01-01

    Color is one of the most powerful aspects of a psychological counseling environment. Little scientific research has been conducted on color design and much of the existing literature is based on observational studies. Using design of experiments and response surface methodology, this paper proposes an optimal color design approach for transforming patients’ perception into color elements. Six indices, pleasant-unpleasant, interesting-uninteresting, exciting-boring, relaxing-distressing, safe-fearful, and active-inactive, were used to assess patients’ impression. A total of 75 patients participated, including 42 for Experiment 1 and 33 for Experiment 2. 27 representative color samples were designed in Experiment 1, and the color sample (L = 75, a = 0, b = -60) was the most preferred one. In Experiment 2, this color sample was set as the ‘central point’, and three color attributes were optimized to maximize the patients’ satisfaction. The experimental results show that the proposed method can get the optimal solution for color design of a counseling room. PMID:24594683

  16. Improved FTA Methodology and Application to Subsea Pipeline Reliability Design

    PubMed Central

    Lin, Jing; Yuan, Yongbo; Zhang, Mingyuan

    2014-01-01

    An innovative logic tree, Failure Expansion Tree (FET), is proposed in this paper, which improves on traditional Fault Tree Analysis (FTA). It describes a different thinking approach for risk factor identification and reliability risk assessment. By providing a more comprehensive and objective methodology, the rather subjective nature of FTA node discovery is significantly reduced and the resulting mathematical calculations for quantitative analysis are greatly simplified. Applied to the Useful Life phase of a subsea pipeline engineering project, the approach provides a more structured analysis by constructing a tree following the laws of physics and geometry. Resulting improvements are summarized in comparison table form. PMID:24667681

  17. Improved FTA methodology and application to subsea pipeline reliability design.

    PubMed

    Lin, Jing; Yuan, Yongbo; Zhang, Mingyuan

    2014-01-01

    An innovative logic tree, Failure Expansion Tree (FET), is proposed in this paper, which improves on traditional Fault Tree Analysis (FTA). It describes a different thinking approach for risk factor identification and reliability risk assessment. By providing a more comprehensive and objective methodology, the rather subjective nature of FTA node discovery is significantly reduced and the resulting mathematical calculations for quantitative analysis are greatly simplified. Applied to the Useful Life phase of a subsea pipeline engineering project, the approach provides a more structured analysis by constructing a tree following the laws of physics and geometry. Resulting improvements are summarized in comparison table form.

  18. Probabilistic Design Methodology and its Application to the Design of an Umbilical Retract Mechanism

    NASA Technical Reports Server (NTRS)

    Onyebueke, Landon; Ameye, Olusesan

    2002-01-01

    A lot has been learned from past experience with structural and machine element failures. The understanding of failure modes and the application of an appropriate design analysis method can lead to improved structural and machine element safety as well as serviceability. To apply Probabilistic Design Methodology (PDM), all uncertainties are modeled as random variables with selected distribution types, means, and standard deviations. It is quite difficult to achieve a robust design without considering the randomness of the design parameters which is the case in the use of the Deterministic Design Approach. The US Navy has a fleet of submarine-launched ballistic missiles. An umbilical plug joins the missile to the submarine in order to provide electrical and cooling water connections. As the missile leaves the submarine, an umbilical retract mechanism retracts the umbilical plug clear of the advancing missile after disengagement during launch and retrains the plug in the retracted position. The design of the current retract mechanism in use was based on the deterministic approach which puts emphasis on factor of safety. A new umbilical retract mechanism that is simpler in design, lighter in weight, more reliable, easier to adjust, and more cost effective has become desirable since this will increase the performance and efficiency of the system. This paper reports on a recent project performed at Tennessee State University for the US Navy that involved the application of PDM to the design of an umbilical retract mechanism. This paper demonstrates how the use of PDM lead to the minimization of weight and cost, and the maximization of reliability and performance.

  19. Probabilistic Design Methodology and its Application to the Design of an Umbilical Retract Mechanism

    NASA Technical Reports Server (NTRS)

    Onyebueke, Landon; Ameye, Olusesan

    2002-01-01

    A lot has been learned from past experience with structural and machine element failures. The understanding of failure modes and the application of an appropriate design analysis method can lead to improved structural and machine element safety as well as serviceability. To apply Probabilistic Design Methodology (PDM), all uncertainties are modeled as random variables with selected distribution types, means, and standard deviations. It is quite difficult to achieve a robust design without considering the randomness of the design parameters which is the case in the use of the Deterministic Design Approach. The US Navy has a fleet of submarine-launched ballistic missiles. An umbilical plug joins the missile to the submarine in order to provide electrical and cooling water connections. As the missile leaves the submarine, an umbilical retract mechanism retracts the umbilical plug clear of the advancing missile after disengagement during launch and retrains the plug in the retracted position. The design of the current retract mechanism in use was based on the deterministic approach which puts emphasis on factor of safety. A new umbilical retract mechanism that is simpler in design, lighter in weight, more reliable, easier to adjust, and more cost effective has become desirable since this will increase the performance and efficiency of the system. This paper reports on a recent project performed at Tennessee State University for the US Navy that involved the application of PDM to the design of an umbilical retract mechanism. This paper demonstrates how the use of PDM lead to the minimization of weight and cost, and the maximization of reliability and performance.

  20. Probabilistic Design Methodology and its Application to the Design of an Umbilical Retract Mechanism

    NASA Astrophysics Data System (ADS)

    Onyebueke, Landon; Ameye, Olusesan

    2002-10-01

    A lot has been learned from past experience with structural and machine element failures. The understanding of failure modes and the application of an appropriate design analysis method can lead to improved structural and machine element safety as well as serviceability. To apply Probabilistic Design Methodology (PDM), all uncertainties are modeled as random variables with selected distribution types, means, and standard deviations. It is quite difficult to achieve a robust design without considering the randomness of the design parameters which is the case in the use of the Deterministic Design Approach. The US Navy has a fleet of submarine-launched ballistic missiles. An umbilical plug joins the missile to the submarine in order to provide electrical and cooling water connections. As the missile leaves the submarine, an umbilical retract mechanism retracts the umbilical plug clear of the advancing missile after disengagement during launch and retrains the plug in the retracted position. The design of the current retract mechanism in use was based on the deterministic approach which puts emphasis on factor of safety. A new umbilical retract mechanism that is simpler in design, lighter in weight, more reliable, easier to adjust, and more cost effective has become desirable since this will increase the performance and efficiency of the system. This paper reports on a recent project performed at Tennessee State University for the US Navy that involved the application of PDM to the design of an umbilical retract mechanism. This paper demonstrates how the use of PDM lead to the minimization of weight and cost, and the maximization of reliability and performance.

  1. The Navigation Guide systematic review methodology: a rigorous and transparent method for translating environmental health science into better health outcomes.

    PubMed

    Woodruff, Tracey J; Sutton, Patrice

    2014-10-01

    Synthesizing what is known about the environmental drivers of health is instrumental to taking prevention-oriented action. Methods of research synthesis commonly used in environmental health lag behind systematic review methods developed in the clinical sciences over the past 20 years. We sought to develop a proof of concept of the "Navigation Guide," a systematic and transparent method of research synthesis in environmental health. The Navigation Guide methodology builds on best practices in research synthesis in evidence-based medicine and environmental health. Key points of departure from current methods of expert-based narrative review prevalent in environmental health include a prespecified protocol, standardized and transparent documentation including expert judgment, a comprehensive search strategy, assessment of "risk of bias," and separation of the science from values and preferences. Key points of departure from evidence-based medicine include assigning a "moderate" quality rating to human observational studies and combining diverse evidence streams. The Navigation Guide methodology is a systematic and rigorous approach to research synthesis that has been developed to reduce bias and maximize transparency in the evaluation of environmental health information. Although novel aspects of the method will require further development and validation, our findings demonstrated that improved methods of research synthesis under development at the National Toxicology Program and under consideration by the U.S. Environmental Protection Agency are fully achievable. The institutionalization of robust methods of systematic and transparent review would provide a concrete mechanism for linking science to timely action to prevent harm.

  2. Highly efficient design methodology for very large scale coupled microcavities

    NASA Astrophysics Data System (ADS)

    Swillam, Mohamed A.; Ahmed, Osman S.; Bakr, Mohamed H.; Li, Xun

    2012-10-01

    We propose a novel approach for efficient design of large number of coupled microcavities. This approach is based on formulating the design problem as an convex optimization problem. This formulation allows for fast, efficient solution of the desing problem. A filter design using 150 coupled microcavities has been achieved in less than one second of simulation using personal computer. The proposed technique require no initial desing to start the optimization process.

  3. Design Thinking: A Methodology towards Sustainable Problem Solving in Higher Education in South Africa

    ERIC Educational Resources Information Center

    Munyai, Keneilwe

    2016-01-01

    This short paper explores the potential contribution of design thinking methodology to the education and training system in South Africa. Design thinking is slowly gaining traction in South Africa. Design Thinking is gaining traction in South Africa. There is offered by the Hasso Plattner Institute of Design Thinking at the University of Cape Town…

  4. Which decision rules meet methodological standards in children with febrile neutropenia? Results of a systematic review and analysis.

    PubMed

    Delebarre, Mathilde; Macher, Emilie; Mazingue, Françoise; Martinot, Alain; Dubos, François

    2014-10-01

    Clinical decision rules (CDRs) have sought to identify the few children with chemotherapy-induced febrile neutropenia (FN) really at risk of severe infection to reduce the invasive procedures and costs for those at low risk. Several reports have shown that most rules do not perform well enough to be clinically useful. Our objective was to analyze the derivation methods and validation procedures of these CDRs. A systematic review using Medline, Ovid, Refdoc, and the Cochrane Library through December 2012 searched for all CDRs predicting the risk of severe infection and/or complications in children with chemotherapy-induced FN. Their methodological quality was analyzed by 17 criteria for deriving and validating a CDR identified in the literature. The criteria published by the Evidence Based Medicine Working Group were applied to the published validations of each CDR to assess their level of evidence. The systematic research identified 612 articles and retained 12 that derived CDRs. Overall, the CDRs met a median of 65% of the methodological criteria. The criteria met least often were that the rule made clinical sense, or described the course of action, or that the variables and the CDR were reproducible. Only one CDR, developed in South America, met all methodological criteria and provided the highest level of evidence; unfortunately it was not reproducible in Europe. Only one CDR developed for children with FN met all methodological standards and reached the highest level of evidence. © 2014 Wiley Periodicals, Inc.

  5. The HIV care cascade: a systematic review of data sources, methodology and comparability

    PubMed Central

    Medland, Nicholas A; McMahon, James H; Chow, Eric PF; Elliott, Julian H; Hoy, Jennifer F; Fairley, Christopher K

    2015-01-01

    Introduction The cascade of HIV diagnosis, care and treatment (HIV care cascade) is increasingly used to direct and evaluate interventions to increase population antiretroviral therapy (ART) coverage, a key component of treatment as prevention. The ability to compare cascades over time, sub-population, jurisdiction or country is important. However, differences in data sources and methodology used to construct the HIV care cascade might limit its comparability and ultimately its utility. Our aim was to review systematically the different methods used to estimate and report the HIV care cascade and their comparability. Methods A search of published and unpublished literature through March 2015 was conducted. Cascades that reported the continuum of care from diagnosis to virological suppression in a demographically definable population were included. Data sources and methods of measurement or estimation were extracted. We defined the most comparable cascade elements as those that directly measured diagnosis or care from a population-based data set. Results and discussions Thirteen reports were included after screening 1631 records. The undiagnosed HIV-infected population was reported in seven cascades, each of which used different data sets and methods and could not be considered to be comparable. All 13 used mandatory HIV diagnosis notification systems to measure the diagnosed population. Population-based data sets, derived from clinical data or mandatory reporting of CD4 cell counts and viral load tests from all individuals, were used in 6 of 12 cascades reporting linkage, 6 of 13 reporting retention, 3 of 11 reporting ART and 6 of 13 cascades reporting virological suppression. Cascades with access to population-based data sets were able to directly measure cascade elements and are therefore comparable over time, place and sub-population. Other data sources and methods are less comparable. Conclusions To ensure comparability, countries wishing to accurately measure

  6. Manufacturing-aware design methodologies for mixed-signal communication circuits

    NASA Astrophysics Data System (ADS)

    Carballo, Juan A.; Nassif, Sani

    2004-05-01

    Mixed-signal communication circuits are becoming a very common component of systems-on-a-chip as part of modern communication systems. The implementation of DFM and DFT methodologies is critical to enhance communication across the tape-out barrier critical for these circuits. We present a manufacturing-aware design methodology specifically targeting integrated communication circuits in systems-on-a-chip (SoC). The key principle behind the methodology is that flexible design methods which can effectively adjust a design"s power consumption and functionality to its application can also provide critical reductions in manufacturing-induced design risk. The methodology is based on the following four techniques: goal-based design that directly relates top level goals with low level manufacturing-dependent parameters; semi-custom voltage-island physical design techniques; adaptive architecture design; and intelligent on-line at-speed monitoring and problem determination techniques. We describe these four methodology features, and illustrate them on a multi-protocol CMOS 3.2 Gbits/second low-power serial communications core. The presented data shows how this methodology results in better and more cost-effective adaptability of the design to manufacturing and post-manufacturing conditions, thereby improving turnaround time, yield, and overall profit.

  7. Participant Observation, Anthropology Methodology and Design Anthropology Research Inquiry

    ERIC Educational Resources Information Center

    Gunn, Wendy; Løgstrup, Louise B.

    2014-01-01

    Within the design studio, and across multiple field sites, the authors compare involvement of research tools and materials during collaborative processes of designing. Their aim is to trace temporal dimensions (shifts/ movements) of where and when learning takes place along different sites of practice. They do so by combining participant…

  8. A Fundamental Methodology for Designing Management Information Systems for Schools.

    ERIC Educational Resources Information Center

    Visscher, Adrie J.

    Computer-assisted school information systems (SISs) are developed and used worldwide; however, the literature on strategies for their design and development is lacking. This paper presents the features of a fundamental approach to systems design that proved to be successful when developing SCHOLIS, a computer-assisted SIS for Dutch secondary…

  9. Participatory Pattern Workshops: A Methodology for Open Learning Design Inquiry

    ERIC Educational Resources Information Center

    Mor, Yishay; Warburton, Steven; Winters, Niall

    2012-01-01

    In order to promote pedagogically informed use of technology, educators need to develop an active, inquisitive, design-oriented mindset. Design Patterns have been demonstrated as powerful mediators of theory-praxis conversations yet widespread adoption by the practitioner community remains a challenge. Over several years, the authors and their…

  10. Participant Observation, Anthropology Methodology and Design Anthropology Research Inquiry

    ERIC Educational Resources Information Center

    Gunn, Wendy; Løgstrup, Louise B.

    2014-01-01

    Within the design studio, and across multiple field sites, the authors compare involvement of research tools and materials during collaborative processes of designing. Their aim is to trace temporal dimensions (shifts/ movements) of where and when learning takes place along different sites of practice. They do so by combining participant…

  11. An overview and methodological assessment of systematic reviews and meta-analyses of enhanced recovery programmes in colorectal surgery.

    PubMed

    Chambers, Duncan; Paton, Fiona; Wilson, Paul; Eastwood, Alison; Craig, Dawn; Fox, Dave; Jayne, David; McGinnes, Erika

    2014-05-30

    To identify and critically assess the extent to which systematic reviews of enhanced recovery programmes for patients undergoing colorectal surgery differ in their methodology and reported estimates of effect. Review of published systematic reviews. We searched the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA) Database from 1990 to March 2013. Systematic reviews of enhanced recovery programmes for patients undergoing colorectal surgery were eligible for inclusion. The primary outcome was length of hospital stay. We assessed changes in pooled estimates of treatment effect over time and how these might have been influenced by decisions taken by researchers as well as by the availability of new trials. The quality of systematic reviews was assessed using the Centre for Reviews and Dissemination (CRD) DARE critical appraisal process. 10 systematic reviews were included. Systematic reviews of randomised controlled trials have consistently shown a reduction in length of hospital stay with enhanced recovery compared with traditional care. The estimated effect tended to increase from 2006 to 2010 as more trials were published but has not altered significantly in the most recent review, despite the inclusion of several unique trials. The best estimate appears to be an average reduction of around 2.5 days in primary postoperative length of stay. Differences between reviews reflected differences in interpretation of inclusion criteria, searching and analytical methods or software. Systematic reviews of enhanced recovery programmes show a high level of research waste, with multiple reviews covering identical or very similar groups of trials. Where multiple reviews exist on a topic, interpretation may require careful attention to apparently minor differences between reviews. Researchers can help readers by acknowledging existing reviews and through clear reporting of key decisions

  12. Methodology Used to Assess Acceptability of Oral Pediatric Medicines: A Systematic Literature Search and Narrative Review.

    PubMed

    Mistry, Punam; Batchelor, Hannah

    2017-06-01

    Regulatory guidelines require that any new medicine designed for a pediatric population must be demonstrated as being acceptable to that population. There is currently no guidance on how to conduct or report on acceptability testing. Our objective was to undertake a review of the methods used to assess the acceptability of medicines within a pediatric population and use this review to propose the most appropriate methodology. We used a defined search strategy to identify literature reports of acceptability assessments of medicines conducted within pediatric populations and extracted information about the tools used in these studies for comparison across studies. In total, 61 articles were included in the analysis. Palatability was the most common (54/61) attribute measured when evaluating acceptability. Simple scale methods were most commonly used, with visual analog scales (VAS) and hedonic scales used both separately and in combination in 34 of the 61 studies. Hedonic scales alone were used in 14 studies and VAS alone in just five studies. Other tools included Likert scales; forced choice or preference; surveys or questionnaires; observations of facial expressions during administration, ease of swallowing, or ability to swallow the dosage; prevalence of complaints or refusal to take the medicine; and time taken for a nurse to administer the medicine. The best scale in terms of validity, reliability, feasibility, and preference to use when assessing acceptability remains unclear. Further work is required to select the most appropriate method to justify whether a medicine is acceptable to a pediatric population.

  13. Optimizing drug delivery systems using systematic "design of experiments." Part I: fundamental aspects.

    PubMed

    Singh, Bhupinder; Kumar, Rajiv; Ahuja, Naveen

    2005-01-01

    Design of an impeccable drug delivery product normally encompasses multiple objectives. For decades, this task has been attempted through trial and error, supplemented with the previous experience, knowledge, and wisdom of the formulator. Optimization of a pharmaceutical formulation or process using this traditional approach involves changing one variable at a time. Using this methodology, the solution of a specific problematic formulation characteristic can certainly be achieved, but attainment of the true optimal composition is never guaranteed. And for improvement in one characteristic, one has to trade off for degeneration in another. This customary approach of developing a drug product or process has been proved to be not only uneconomical in terms of time, money, and effort, but also unfavorable to fix errors, unpredictable, and at times even unsuccessful. On the other hand, the modern formulation optimization approaches, employing systematic Design of Experiments (DoE), are extensively practiced in the development of diverse kinds of drug delivery devices to improve such irregularities. Such systematic approaches are far more advantageous, because they require fewer experiments to achieve an optimum formulation, make problem tracing and rectification quite easier, reveal drug/polymer interactions, simulate the product performance, and comprehend the process to assist in better formulation development and subsequent scale-up. Optimization techniques using DoE represent effective and cost-effective analytical tools to yield the "best solution" to a particular "problem." Through quantification of drug delivery systems, these approaches provide a depth of understanding as well as an ability to explore and defend ranges for formulation factors, where experimentation is completed before optimization is attempted. The key elements of a DoE optimization methodology encompass planning the study objectives, screening of influential variables, experimental designs

  14. Application of optimal design methodologies in clinical pharmacology experiments.

    PubMed

    Ogungbenro, Kayode; Dokoumetzidis, Aristides; Aarons, Leon

    2009-01-01

    Pharmacokinetics and pharmacodynamics data are often analysed by mixed-effects modelling techniques (also known as population analysis), which has become a standard tool in the pharmaceutical industries for drug development. The last 10 years has witnessed considerable interest in the application of experimental design theories to population pharmacokinetic and pharmacodynamic experiments. Design of population pharmacokinetic experiments involves selection and a careful balance of a number of design factors. Optimal design theory uses prior information about the model and parameter estimates to optimize a function of the Fisher information matrix to obtain the best combination of the design factors. This paper provides a review of the different approaches that have been described in the literature for optimal design of population pharmacokinetic and pharmacodynamic experiments. It describes options that are available and highlights some of the issues that could be of concern as regards practical application. It also discusses areas of application of optimal design theories in clinical pharmacology experiments. It is expected that as the awareness about the benefits of this approach increases, more people will embrace it and ultimately will lead to more efficient population pharmacokinetic and pharmacodynamic experiments and can also help to reduce both cost and time during drug development.

  15. Design methodology and application of high speed gate arrays

    NASA Astrophysics Data System (ADS)

    Decker, R.

    A system to provide real-time signal averaging of waveforms from a 50 MHz analog to digital converter has been fabricated to operate over a wide temperature range. This system evolved from conception, through an initial simulated design for emitter coupled logic (ECL), to a pair of CMOS gate array designs. Changing the implementation technology to CMOS gate arrays resulted in savings in cost, size, weight, and power. Design rules employed to obtain working silicon on the first cycle, at double state-of-the-art gate array speeds, are discussed. Also discussed are built-in, run-time, self-test features.

  16. Developing risk prediction models for type 2 diabetes: a systematic review of methodology and reporting

    PubMed Central

    2011-01-01

    Background The World Health Organisation estimates that by 2030 there will be approximately 350 million people with type 2 diabetes. Associated with renal complications, heart disease, stroke and peripheral vascular disease, early identification of patients with undiagnosed type 2 diabetes or those at an increased risk of developing type 2 diabetes is an important challenge. We sought to systematically review and critically assess the conduct and reporting of methods used to develop risk prediction models for predicting the risk of having undiagnosed (prevalent) or future risk of developing (incident) type 2 diabetes in adults. Methods We conducted a systematic search of PubMed and EMBASE databases to identify studies published before May 2011 that describe the development of models combining two or more variables to predict the risk of prevalent or incident type 2 diabetes. We extracted key information that describes aspects of developing a prediction model including study design, sample size and number of events, outcome definition, risk predictor selection and coding, missing data, model-building strategies and aspects of performance. Results Thirty-nine studies comprising 43 risk prediction models were included. Seventeen studies (44%) reported the development of models to predict incident type 2 diabetes, whilst 15 studies (38%) described the derivation of models to predict prevalent type 2 diabetes. In nine studies (23%), the number of events per variable was less than ten, whilst in fourteen studies there was insufficient information reported for this measure to be calculated. The number of candidate risk predictors ranged from four to sixty-four, and in seven studies it was unclear how many risk predictors were considered. A method, not recommended to select risk predictors for inclusion in the multivariate model, using statistical significance from univariate screening was carried out in eight studies (21%), whilst the selection procedure was unclear in

  17. Modern design methodology and problems in training aircraft engineers

    NASA Technical Reports Server (NTRS)

    Liseitsev, N. K.

    1989-01-01

    A brief report on the problem of modern aircraft specialist education is presented that is devoted to the content and methods of teaching a course in General Aircraft Design in the Moscow Aviation Institute.

  18. Modern design methodology and problems in training aircraft engineers

    NASA Technical Reports Server (NTRS)

    Liseitsev, N. K.

    1989-01-01

    A brief report on the problem of modern aircraft specialist education is presented that is devoted to the content and methods of teaching a course in General Aircraft Design in the Moscow Aviation Institute.

  19. Information System Design Methodology Based on PERT/CPM Networking and Optimization Techniques.

    ERIC Educational Resources Information Center

    Bose, Anindya

    The dissertation attempts to demonstrate that the program evaluation and review technique (PERT)/Critical Path Method (CPM) or some modified version thereof can be developed into an information system design methodology. The methodology utilizes PERT/CPM which isolates the basic functional units of a system and sets them in a dynamic time/cost…

  20. Information System Design Methodology Based on PERT/CPM Networking and Optimization Techniques.

    ERIC Educational Resources Information Center

    Bose, Anindya

    The dissertation attempts to demonstrate that the program evaluation and review technique (PERT)/Critical Path Method (CPM) or some modified version thereof can be developed into an information system design methodology. The methodology utilizes PERT/CPM which isolates the basic functional units of a system and sets them in a dynamic time/cost…

  1. Uptake of newer methodological developments and the deployment of meta-analysis in diagnostic test research: a systematic review

    PubMed Central

    2011-01-01

    Background The last decade has seen a number of methodological developments in meta-analysis of diagnostic test studies. However, it is unclear whether such developments have permeated the wider research community and on which applications they are being deployed. The objective was to assess the uptake and deployment of the main methodological developments in the meta-analysis of diagnostic tests, and identify the tests and target disorders most commonly evaluated by meta-analysis. Methods Design - systematic review. Data Sources - Medline, EMBASE, CINAHL, Cochrane, PsychInfo, Global health, HMIC, and AMED were searched for studies published before 31st December 2008. Selection criteria - studies were included if they satisfied all of the following: evaluated a diagnostic test; measured test performance; searched two or more databases; stated search terms and inclusion criteria; used a statistical method to summarise performance. Data extraction - included the following data items: year; test; reference standard; target disorder; setting; statistical and quality methods. Results 236 studies were included. Over the last 5 years the number of meta-analyses published has increased, but the uptake of new statistical methods lags behind. Pooling the sensitivity and specificity and using the SROC remain the preferred methods for analysis in 70% of studies, with the bivariate random effects and HSROC model being used in only 22% and 5% of studies respectively. In contrast, between 2006 and 2008 the QUADAS tool was used in 40% of studies. Broadly, radiological imaging was the most frequent category of tests analysed (36%), with cancer (22%) and infection (21%) being the most common categories of target disorder. Nearly 80% of tests analysed were those normally used in specialist settings. Conclusion Although quality assessment in meta-analyses has improved with the introduction of QUADAS, uptake of the newer statistical methods is still lagging behind. Furthermore, the

  2. The quality of reporting methods and results of cost-effectiveness analyses in Spain: a methodological systematic review.

    PubMed

    Catalá-López, Ferrán; Ridao, Manuel; Alonso-Arroyo, Adolfo; García-Altés, Anna; Cameron, Chris; González-Bermejo, Diana; Aleixandre-Benavent, Rafael; Bernal-Delgado, Enrique; Peiró, Salvador; Tabarés-Seisdedos, Rafael; Hutton, Brian

    2016-01-07

    Cost-effectiveness analysis has been recognized as an important tool to determine the efficiency of healthcare interventions and services. There is a need for evaluating the reporting of methods and results of cost-effectiveness analyses and establishing their validity. We describe and examine reporting characteristics of methods and results of cost-effectiveness analyses conducted in Spain during more than two decades. A methodological systematic review was conducted with the information obtained through an updated literature review in PubMed and complementary databases (e.g. Scopus, ISI Web of Science, National Health Service Economic Evaluation Database (NHS EED) and Health Technology Assessment (HTA) databases from Centre for Reviews and Dissemination (CRD), Índice Médico Español (IME) Índice Bibliográfico Español en Ciencias de la Salud (IBECS)). We identified cost-effectiveness analyses conducted in Spain that used quality-adjusted life years (QALYs) as outcome measures (period 1989-December 2014). Two reviewers independently extracted the data from each paper. The data were analysed descriptively. In total, 223 studies were included. Very few studies (10; 4.5 %) reported working from a protocol. Most studies (200; 89.7 %) were simulation models and included a median of 1000 patients. Only 105 (47.1 %) studies presented an adequate description of the characteristics of the target population. Most study interventions were categorized as therapeutic (189; 84.8 %) and nearly half (111; 49.8 %) considered an active alternative as the comparator. Effectiveness of data was derived from a single study in 87 (39.0 %) reports, and only few (40; 17.9 %) used evidence synthesis-based estimates. Few studies (42; 18.8 %) reported a full description of methods for QALY calculation. The majority of the studies (147; 65.9 %) reported that the study intervention produced "more costs and more QALYs" than the comparator. Most studies (200; 89.7 %) reported favourable

  3. The relationship between maternal methadone dose at delivery and neonatal outcome: methodological and design considerations.

    PubMed

    Jones, Hendrée E; Jansson, Lauren M; O'Grady, Kevin E; Kaltenbach, Karol

    2013-01-01

    Compared to untreated opioid dependence, methadone maintenance treatment of opioid-dependent pregnant women has been found to be associated with better maternal and neonatal outcomes. Secondary analysis of data from 73 maternal and neonatal participants in the MOTHER study (H. E. Jones et al., New England Journal of Medicine, 2010) found no relationship between maternal methadone dose at delivery and any of 9 neonatal outcomes--peak neonatal abstinence syndrome (NAS) score, total amount of morphine needed to treat NAS, duration of neonatal hospital stay, duration of treatment for NAS, estimated gestational age at delivery, Apgar score at 5 min, and neonatal head circumference, length, and weight at birth. These results are consistent with a recent systematic review and meta-analysis (B. J. Cleary et al., Addiction, 2010) and extend findings to outcomes other than NAS. Methodological and design issues that might have adversely impacted the ability of researchers to establish the existence or non-existence of these relationships are considered. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. [Variations in the epidemiolgy of adverse events: methodology of the Harvard Medical Practice Design].

    PubMed

    Lessing, C; Schmitz, A; Schrappe, M

    2012-02-01

    The Harvard Medical Practice (HMP) Design is based on a multi-staged retrospective review of inpatient records and is used to assess the frequency of (preventable) adverse events ([P]AE) in large study populations. Up to now HMP studies have been conducted in 9 countries. Results differ largely from 2.9% to 3.7% of patients with AE in the USA up to 16.6% in Australia. In our analysis we systematically compare the methodology of 9 HMP studies published in the English language and discuss possible impacts on reported frequencies. Modifications in HMP studies can be individualised from each stage of planning, conducting, and reporting results. In doing so 2 studies from the USA with lowest rates of AE can be characterised by their context of liability and the absence of screening for nosocomial infections. Studies with a high proportion of AE are marked by an intense training of reviewers. Further conclusions are hindered by divergences in defining periods of observation, by presenting frequencies as cumulative prevalences, and differences in the reporting of study results. As a consequence future HMP studies should go for complete, consistent and transparent coverage. Further research should concentrate on advancing methods for collecting data on (P)AE.

  5. The relationship between maternal methadone dose at delivery and neonatal outcome: Methodological and design considerations

    PubMed Central

    Jones, Hendrée E.; Jansson, Lauren M.; O’Grady, Kevin E.; Kaltenbach, Karol

    2013-01-01

    Compared to untreated opioid dependence, methadone maintenance treatment of opioid-dependent pregnant women has been found to be associated with better maternal and neonatal outcomes. Secondary analysis of data from 73 maternal and neonatal participants in the MOTHER study (H. E. Jones et al., New England Journal of Medicine, 2010) found no relationship between maternal methadone dose at delivery and any of 9 neonatal outcomes – peak neonatal abstinence syndrome (NAS) score, total amount of morphine needed to treat NAS, duration of neonatal hospital stay, duration of treatment for NAS, estimated gestational age at delivery, Apgar score at 5 minutes, and neonatal head circumference, length, and weight at birth. These results are consistent with a recent systematic review and meta-analysis (B. J. Cleary et al., Addiction, 2010) and extend findings to outcomes other than NAS. Methodological and design issues that might have adversely impacted the ability of researchers to establish the existence or non-existence of these relationships are considered. PMID:24099621

  6. Structural Design Methodology Based on Concepts of Uncertainty

    NASA Technical Reports Server (NTRS)

    Lin, K. Y.; Du, Jiaji; Rusk, David

    2000-01-01

    In this report, an approach to damage-tolerant aircraft structural design is proposed based on the concept of an equivalent "Level of Safety" that incorporates past service experience in the design of new structures. The discrete "Level of Safety" for a single inspection event is defined as the compliment of the probability that a single flaw size larger than the critical flaw size for residual strength of the structure exists, and that the flaw will not be detected. The cumulative "Level of Safety" for the entire structure is the product of the discrete "Level of Safety" values for each flaw of each damage type present at each location in the structure. Based on the definition of "Level of Safety", a design procedure was identified and demonstrated on a composite sandwich panel for various damage types, with results showing the sensitivity of the structural sizing parameters to the relative safety of the design. The "Level of Safety" approach has broad potential application to damage-tolerant aircraft structural design with uncertainty.

  7. Methodology Series Module 8: Designing Questionnaires and Clinical Record Forms.

    PubMed

    Setia, Maninder Singh

    2017-01-01

    As researchers, we often collect data on a clinical record form or a questionnaire. It is an important part of study design. If the questionnaire is not well designed, the data collected will not be useful. In this section of the module, we have discussed some practical aspects of designing a questionnaire. It is useful to make a list of all the variables that will be assessed in the study before preparing the questionnaire. The researcher should review all the existing questionnaires. It may be efficient to use an existing standardized questionnaire or scale. Many of these scales are freely available and may be used with an appropriate reference. However, some may be under copyright protection and permissions may be required to use the same questionnaire. While designing their own questionnaire, researchers may use open- or close-ended questions. It is important to design the responses appropriately as the format of responses will influence the analysis. Sometimes, one can collect the same information in multiple ways - continuous or categorical response. Besides these, the researcher can also use visual analog scales or Likert's scale in the questionnaire. Some practical take-home points are: (1) Use specific language while framing the questions; (2) write detailed instructions in the questionnaire; (3) use mutually exclusive response categories; (4) use skip patterns; (5) avoid double-barreled questions; and (6) anchor the time period if required.

  8. Methodology Series Module 8: Designing Questionnaires and Clinical Record Forms

    PubMed Central

    Setia, Maninder Singh

    2017-01-01

    As researchers, we often collect data on a clinical record form or a questionnaire. It is an important part of study design. If the questionnaire is not well designed, the data collected will not be useful. In this section of the module, we have discussed some practical aspects of designing a questionnaire. It is useful to make a list of all the variables that will be assessed in the study before preparing the questionnaire. The researcher should review all the existing questionnaires. It may be efficient to use an existing standardized questionnaire or scale. Many of these scales are freely available and may be used with an appropriate reference. However, some may be under copyright protection and permissions may be required to use the same questionnaire. While designing their own questionnaire, researchers may use open- or close-ended questions. It is important to design the responses appropriately as the format of responses will influence the analysis. Sometimes, one can collect the same information in multiple ways - continuous or categorical response. Besides these, the researcher can also use visual analog scales or Likert's scale in the questionnaire. Some practical take-home points are: (1) Use specific language while framing the questions; (2) write detailed instructions in the questionnaire; (3) use mutually exclusive response categories; (4) use skip patterns; (5) avoid double-barreled questions; and (6) anchor the time period if required. PMID:28400630

  9. A systematic review of studies evaluating Australian indigenous community development projects: the extent of community participation, their methodological quality and their outcomes.

    PubMed

    Snijder, Mieke; Shakeshaft, Anthony; Wagemakers, Annemarie; Stephens, Anne; Calabria, Bianca

    2015-11-21

    Community development is a health promotion approach identified as having great potential to improve Indigenous health, because of its potential for extensive community participation. There has been no systematic examination of the extent of community participation in community development projects and little analysis of their effectiveness. This systematic review aims to identify the extent of community participation in community development projects implemented in Australian Indigenous communities, critically appraise the qualitative and quantitative methods used in their evaluation, and summarise their outcomes. Ten electronic peer-reviewed databases and two electronic grey literature databases were searched for relevant studies published between 1990 and 2015. The level of community participation and the methodological quality of the qualitative and quantitative components of the studies were assessed against standardised criteria. Thirty one evaluation studies of community development projects were identified. Community participation varied between different phases of project development, generally high during project implementation, but low during the evaluation phase. For the majority of studies, methodological quality was low and the methods were poorly described. Although positive qualitative or quantitative outcomes were reported in all studies, only two studies reported statistically significant outcomes. Partnerships between researchers, community members and service providers have great potential to improve methodological quality and community participation when research skills and community knowledge are integrated to design, implement and evaluate community development projects. The methodological quality of studies evaluating Australian Indigenous community development projects is currently too weak to confidently determine the cost-effectiveness of community development projects in improving the health and wellbeing of Indigenous Australians

  10. New methodology for shaft design based on life expectancy

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1986-01-01

    The design of power transmission shafting for reliability has not historically received a great deal of attention. However, weight sensitive aerospace and vehicle applications and those where the penalties of shaft failure are great, require greater confidence in shaft design than earlier methods provided. This report summarizes a fatigue strength-based, design method for sizing shafts under variable amplitude loading histories for limited or nonlimited service life. Moreover, applications factors such as press-fitted collars, shaft size, residual stresses from shot peening or plating, corrosive environments can be readily accommodated into the framework of the analysis. Examples are given which illustrate the use of the method, pointing out the large life penalties due to occasional cyclic overloads.

  11. Development of probabilistic rigid pavement design methodologies for military airfields

    NASA Astrophysics Data System (ADS)

    Witczak, M. W.; Uzan, J.; Johnson, M.

    1983-12-01

    The current Corps of Engineers design procedures for rigid airfield pavements is based on the Westergaard free edge stress slab theory, and a proposed procedure is based on the multilayer elastic theory. These two design procedures have been expanded to airfield pavement designs expressed in probabilistic and reliability terms. Further developments were required in these procedures to make the analysis more practicable. Two major investigations were conducted: (1) Evaluation and use of the composite modulus of elasticity for layers beneath the rigid pavement, and (2) Evaluation of the maximum tensile stress at the bottom of the slab for different aircraft types. Derivations obtained from the investigation of the composite modulus and maximum tensile stress are reported and are included in computer programs for probabilistic/reliability analysis of rigid pavements. The approximate closed form (Taylor series expansion) is utilized. Example runs of the computer program are presented.

  12. Graphene nanopores: electronic transport properties and design methodology.

    PubMed

    Qiu, Wanzhi; Nguyen, Phuong; Skafidas, Efstratios

    2014-01-28

    Graphene nanopores (GNPs) hold great promise as building blocks for electronic circuitry and sensors for biological and chemical sensing applications. Methods to design graphene nanopores that achieve desirable conduction performance and sensing characteristics have not been previously described. Here we present a study of the quantum transport properties of GNPs created by drilling pores in armchair and zigzag graphene ribbons. For the first time, our study reveals that the quantum transmission spectra of GNPs are highly tunable and GNPs with specific transport properties can be produced by properly designing pore shapes. Our investigation shows that the biological sensing capabilities of GNPs are transmission spectrum dependent, can vary dramatically, and are critically dependent on pore geometry. Our study provides design guidelines for creating graphene nanopores with specific transport properties to meet the needs of diverse applications and for developing sensitive biological/chemical sensors with required performance characteristics.

  13. A systematic approach to design for lifelong aircraft evolution

    NASA Astrophysics Data System (ADS)

    Lim, Dongwook

    This research proposes a systematic approach with which the decision makers can evaluate the value and risk of a new aircraft development program, including potential derivative development opportunities. The proposed Evaluation of Lifelong Vehicle Evolution (EvoLVE) method is a two- or multi-stage representation of the aircraft design process that accommodates initial development phases as well as follow-on phases. One of the key elements of this method is the Stochastic Programming with Recourse (SPR) technique, which accounts for uncertainties associated with future requirements. The remedial approach of SPR in its two distinctive problem-solving steps is well suited to aircraft design problems where derivatives, retrofits, and upgrades have been used to fix designs that were once but no longer optimal. The solution approach of SPR is complemented by the Risk-Averse Strategy Selection (RASS) technique to gauge risk associated with vehicle evolution options. In the absence of a full description of the random space, a scenario-based approach captures the randomness with a few probable scenarios and reveals implications of different future events. Last, an interactive framework for decision-making support allows simultaneous navigation of the current and future design space with a greater degree of freedom. A cantilevered beam design problem was set up and solved using the SPR technique to showcase its application to an engineering design setting. The full EvoLVE method was conducted on a notional multi-role fighter based on the F/A-18 Hornet.

  14. Structural design methodologies for ceramic-based material systems

    NASA Technical Reports Server (NTRS)

    Duffy, Stephen F.; Chulya, Abhisak; Gyekenyesi, John P.

    1991-01-01

    One of the primary pacing items for realizing the full potential of ceramic-based structural components is the development of new design methods and protocols. The focus here is on low temperature, fast-fracture analysis of monolithic, whisker-toughened, laminated, and woven ceramic composites. A number of design models and criteria are highlighted. Public domain computer algorithms, which aid engineers in predicting the fast-fracture reliability of structural components, are mentioned. Emphasis is not placed on evaluating the models, but instead is focused on the issues relevant to the current state of the art.

  15. Local Design Methodologies for a Hierarchic Control Architecture

    DTIC Science & Technology

    1990-04-12

    decentralized manner. This design is based on the concept of the disturbance information "flowing" along the structure as " waves ". A control...computer. This design is based on a view of the disturbances "flowing"along a structure as " waves ", and the implementation is done in such a way as to...Company, New York, 1986 [47] Miller, D., Modelling and Active Modification of Wave Scattering in Struc- tural Networks, ScD Thesis, MIT Department of

  16. New Methods in Design Education: The Systemic Methodology and the Use of Sketch in the Conceptual Design Stage

    ERIC Educational Resources Information Center

    Westermeyer, Juan Carlos Briede; Ortuno, Bernabe Hernandis

    2011-01-01

    This study describes the application of a new product concurrent design methodologies in the context in the education of industrial design. The use of the sketch has been utilized many times as a tool of creative expression especially in the conceptual design stage, in an intuitive way and a little out of the context of the reality needs that the…

  17. New systematic methodology for incorporating dynamic heat transfer modelling in multi-phase biochemical reactors.

    PubMed

    Fernández-Arévalo, T; Lizarralde, I; Grau, P; Ayesa, E

    2014-09-01

    This paper presents a new modelling methodology for dynamically predicting the heat produced or consumed in the transformations of any biological reactor using Hess's law. Starting from a complete description of model components stoichiometry and formation enthalpies, the proposed modelling methodology has integrated successfully the simultaneous calculation of both the conventional mass balances and the enthalpy change of reaction in an expandable multi-phase matrix structure, which facilitates a detailed prediction of the main heat fluxes in the biochemical reactors. The methodology has been implemented in a plant-wide modelling methodology in order to facilitate the dynamic description of mass and heat throughout the plant. After validation with literature data, as illustrative examples of the capability of the methodology, two case studies have been described. In the first one, a predenitrification-nitrification dynamic process has been analysed, with the aim of demonstrating the easy integration of the methodology in any system. In the second case study, the simulation of a thermal model for an ATAD has shown the potential of the proposed methodology for analysing the effect of ventilation and influent characterization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Design and Methodology of the Korean Early Psychosis Cohort Study

    PubMed Central

    Kim, Sung-Wan; Lee, Bong Ju; Kim, Jung Jin; Yu, Je-Chun; Lee, Kyu Young; Won, Seung-Hee; Lee, Seung-Hwan; Kim, Seung-Hyun; Kang, Shi Hyun

    2017-01-01

    The present study details the rationale and methodology of the Korean Early Psychosis Cohort Study (KEPS), which is a clinical cohort investigation of first episode psychosis patients from a Korean population. The KEPS is a prospective naturalistic observational cohort study that follows the participants for at least 2 years. This study includes patients between 18 and 45 years of age who fulfill the criteria for one of schizophrenia spectrum and other psychotic disorders according to the diagnostic criteria of DSM-5. Early psychosis is defined as first episode patients who received antipsychotic treatment for fewer than 4 consecutive weeks after the onset of illness or stabilized patients in the early stages of the disorder whose duration of illness was less than 2 years from the initiation of antipsychotic treatment. The primary outcome measures are treatment response, remission, recovery, and relapse. Additionally, several laboratory tests are conducted and a variety of objective and subjective psychiatric measures assessing early life trauma, lifestyle pattern, and social and cognitive functioning are administered. This long-term prospective cohort study may contribute to the development of early intervention strategies and the improvement of long-term outcomes in patients with schizophrenia. PMID:28096881

  19. Situated Research Design and Methodological Choices in Formative Program Evaluation

    ERIC Educational Resources Information Center

    Supovitz, Jonathan

    2013-01-01

    Design-based implementation research offers the opportunity to rethink the relationships between intervention, research, and situation to better attune research and evaluation to the program development process. Using a heuristic called the intervention development curve, I describe the rough trajectory that programs typically follow as they…

  20. Kids in the city study: research design and methodology

    PubMed Central

    2011-01-01

    Background Physical activity is essential for optimal physical and psychological health but substantial declines in children's activity levels have occurred in New Zealand and internationally. Children's independent mobility (i.e., outdoor play and traveling to destinations unsupervised), an integral component of physical activity in childhood, has also declined radically in recent decades. Safety-conscious parenting practices, car reliance and auto-centric urban design have converged to produce children living increasingly sedentary lives. This research investigates how urban neighborhood environments can support or enable or restrict children's independent mobility, thereby influencing physical activity accumulation and participation in daily life. Methods/Design The study is located in six Auckland, New Zealand neighborhoods, diverse in terms of urban design attributes, particularly residential density. Participants comprise 160 children aged 9-11 years and their parents/caregivers. Objective measures (global positioning systems, accelerometers, geographical information systems, observational audits) assessed children's independent mobility and physical activity, neighborhood infrastructure, and streetscape attributes. Parent and child neighborhood perceptions and experiences were assessed using qualitative research methods. Discussion This study is one of the first internationally to examine the association of specific urban design attributes with child independent mobility. Using robust, appropriate, and best practice objective measures, this study provides robust epidemiological information regarding the relationships between the built environment and health outcomes for this population. PMID:21781341

  1. Serration Design Methodology for Wind Turbine Noise Reduction

    NASA Astrophysics Data System (ADS)

    Mathew, J.; Singh, A.; Madsen, J.; Arce León, C.

    2016-09-01

    Trailing edge serrations are today an established method to reduce the aeroacoustic noise from wind turbine blades. In this paper, a brief introduction to the aerodynamic and acoustic design procedure used at LM Wind Power is given. Early field tests on serrations, retrofitted to the turbine blades, gave preliminary indication of their noise reduction potential. However, a multitude of challenges stand in the way of any proof of concept and a viable commercial product. LM undertook a methodical test and validation procedure to understand the impact of design parameters on serration performance, and quantify the uncertainties associated with the proposed designs. Aerodynamic and acoustic validation tests were carried out in number of wind tunnel facilities. Models were written to predict the aerodynamic, acoustic and structural performance of the serrations. LM serration designs have evolved over the period of time to address constraints imposed by aero performance, structural reliability, manufacturing and installation. The latest LM serration offering was tested in the field on three different wind turbines. A consistent noise reduction in excess of 1.5 dB was achieved in the field for all three turbines.

  2. Design Based Research Methodology for Teaching with Technology in English

    ERIC Educational Resources Information Center

    Jetnikoff, Anita

    2015-01-01

    Design based research (DBR) is an appropriate method for small scale educational research projects involving collaboration between teachers, students and researchers. It is particularly useful in collaborative projects where an intervention is implemented and evaluated in a grounded context. The intervention can be technological, or a new program…

  3. Design Based Research Methodology for Teaching with Technology in English

    ERIC Educational Resources Information Center

    Jetnikoff, Anita

    2015-01-01

    Design based research (DBR) is an appropriate method for small scale educational research projects involving collaboration between teachers, students and researchers. It is particularly useful in collaborative projects where an intervention is implemented and evaluated in a grounded context. The intervention can be technological, or a new program…

  4. Situated Research Design and Methodological Choices in Formative Program Evaluation

    ERIC Educational Resources Information Center

    Supovitz, Jonathan

    2013-01-01

    Design-based implementation research offers the opportunity to rethink the relationships between intervention, research, and situation to better attune research and evaluation to the program development process. Using a heuristic called the intervention development curve, I describe the rough trajectory that programs typically follow as they…

  5. Optimum design criteria for a synchronous reluctance motor with concentrated winding using response surface methodology

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ho; Park, Seong-June; Jeon, Su-Jin

    2006-04-01

    This paper presents an optimization procedure using response surface methodology (RSM) to determine design parameters for reducing torque ripple. The RSM has been achieved to use the experimental design method in combination with finite element method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables.

  6. Application of analytical methods for jointed rock as part of a drift design methodology for the Yucca Mountain Project

    SciTech Connect

    Costin, L.S.; Bauer, S.J.; Hardy, M.P.

    1989-12-08

    The Yucca Mountain Project, managed by the Nevada Operations Office of the US Department of Energy (DOE), is examining the feasibility of siting a repository for high-level nuclear waste at Yucca Mountain, on and adjacent to the Nevada Test Site. Excavation stability will be required during construction, waste emplacement, retrieval (if required), and closure, covering a period of approximately 100 years. In order to incorporate a means of evaluating excavation stability in the design process, a drift design methodology has been developed. This methodology uses both empirical and analytical methods in conjunction with detailed descriptions of site conditions to evaluate a proposed design. At present, the emphasis is on analytical numerical methods because of the limited experience, in tuff at elevated temperatures. This paper describes the proposed methods for analysis of systematically jointed, isotropically jointed, and widely spaced, discretely jointed rock masses. Loads resulting from in situ stress, thermal expansion, and seismic events are considered. Criteria for strength and failure of intact rock and the rock mass are applied to analysis results to assess the stability of proposed drift designs and to guide the design of the ground support system.

  7. Systematic design of highly birefringent photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Hsu, Jui-Ming

    2017-03-01

    This article systematically designs and theoretically investigates a highly birefringent photonic crystal fiber (HB-PCF) for reducing the effect of polarization mode dispersion in high-speed optical communication system. To achieve a high modal birefringence in the proposed HB-PCF, four types of HB-PCF were designed by adding some birefringence-enhancing factors step by step in sequence. Ultimately, as per the simulation results, in the condition of single-mode operation, the numeric values of modal birefringence and confinement loss of the proposed HB-PCF is about 21.85 × 10- 3 and 0.47 dB/km at the habitual wavelength λ = 1.55 µm of optical-fiber communications.

  8. SysSon - A Framework for Systematic Sonification Design

    NASA Astrophysics Data System (ADS)

    Vogt, Katharina; Goudarzi, Visda; Holger Rutz, Hanns

    2015-04-01

    SysSon is a research approach on introducing sonification systematically to a scientific community where it is not yet commonly used - e.g., in climate science. Thereby, both technical and socio-cultural barriers have to be met. The approach was further developed with climate scientists, who participated in contextual inquiries, usability tests and a workshop of collaborative design. Following from these extensive user tests resulted our final software framework. As frontend, a graphical user interface allows climate scientists to parametrize standard sonifications with their own data sets. Additionally, an interactive shell allows to code new sonifications for users competent in sound design. The framework is a standalone desktop application, available as open source (for details see http://sysson.kug.ac.at/) and works with data in NetCDF format.

  9. A general methodology and applications for conduction-like flow-channel design.

    SciTech Connect

    Cummings, Eric B.; Fiechtner, Gregory J.

    2004-02-01

    A novel design methodology is developed for creating conduction devices in which fields are piecewise uniform. This methodology allows the normally analytically intractable problem of Lagrangian transport to be solved using algebraic and trigonometric equations. Low-dispersion turns, manifolds, and expansions are developed. In this methodology, regions of piece-wise constant specific permeability (permeability per unit width) border each other with straight, generally tilted interfaces. The fields within each region are made uniform by satisfying a simple compatibility relation between the tilt angle and ratio of specific permeability of adjacent regions. This methodology has particular promise in the rational design of quasi-planar devices, in which the specific permeability is proportional to the depth of the channel. For such devices, the methodology can be implemented by connecting channel facets having two or more depths, fabricated, e.g., using a simple two-etch process.

  10. Designing a Methodology for Future Air Travel Scenarios

    NASA Technical Reports Server (NTRS)

    Wuebbles, Donald J.; Baughcum, Steven L.; Gerstle, John H.; Edmonds, Jae; Kinnison, Douglas E.; Krull, Nick; Metwally, Munir; Mortlock, Alan; Prather, Michael J.

    1992-01-01

    -subsonic future fleet. The methodology, procedures, and recommendations for the development of future HSCT and the subsonic fleet scenarios used for this evaluation are discussed.

  11. Systematic methodology for estimating direct capital costs for blanket tritium processing systems

    SciTech Connect

    Finn, P.A.

    1985-01-01

    This paper describes the methodology developed for estimating the relative capital costs of blanket processing systems. The capital costs of the nine blanket concepts selected in the Blanket Comparison and Selection Study are presented and compared.

  12. Memristor-Based Computing Architecture: Design Methodologies and Circuit Techniques

    DTIC Science & Technology

    2013-03-01

    simply consists of an NMOS transistor (Q) and a memristor. When the input Vin is low, the transistor Q is turned off. Thus, the output Vout is...connected to ground through the memristor. Conversely, when Vin is high, turning Q on, the memristance M and the equivalent transistor resistance (RQ...synapse design was dependent on the equivalent resistance (effectively, the size) of the Q transistor (RQ). A larger Q would offer a wider range of Vout

  13. Methodological Foundations for Designing Intelligent Computer-Based Training

    DTIC Science & Technology

    1991-09-03

    metacognitive processes (Derry, in press). To this list, we would add that FSM techniques need not be restricted to intelligent tutoring systems. As Chin (1989...systems (pp. 313-333). New York: Springer-Verlag. Derry, S. (in press). Metacognitive models of learning and instructional systems design. In P.H. Winne...15 3.1 Stocks Portfolio Profiler Example .............................. 15 3.1.1 Chart Classes

  14. Kids in the city study: research design and methodology.

    PubMed

    Oliver, Melody; Witten, Karen; Kearns, Robin A; Mavoa, Suzanne; Badland, Hannah M; Carroll, Penelope; Drumheller, Chelsea; Tavae, Nicola; Asiasiga, Lanuola; Jelley, Su; Kaiwai, Hector; Opit, Simon; Lin, En-Yi Judy; Sweetsur, Paul; Barnes, Helen Moewaka; Mason, Nic; Ergler, Christina

    2011-07-24

    Physical activity is essential for optimal physical and psychological health but substantial declines in children's activity levels have occurred in New Zealand and internationally. Children's independent mobility (i.e., outdoor play and traveling to destinations unsupervised), an integral component of physical activity in childhood, has also declined radically in recent decades. Safety-conscious parenting practices, car reliance and auto-centric urban design have converged to produce children living increasingly sedentary lives. This research investigates how urban neighborhood environments can support or enable or restrict children's independent mobility, thereby influencing physical activity accumulation and participation in daily life. The study is located in six Auckland, New Zealand neighborhoods, diverse in terms of urban design attributes, particularly residential density. Participants comprise 160 children aged 9-11 years and their parents/caregivers. Objective measures (global positioning systems, accelerometers, geographical information systems, observational audits) assessed children's independent mobility and physical activity, neighborhood infrastructure, and streetscape attributes. Parent and child neighborhood perceptions and experiences were assessed using qualitative research methods. This study is one of the first internationally to examine the association of specific urban design attributes with child independent mobility. Using robust, appropriate, and best practice objective measures, this study provides robust epidemiological information regarding the relationships between the built environment and health outcomes for this population.

  15. Systematic Reviews and Meta-Analyses of Home Telemonitoring Interventions for Patients With Chronic Diseases: A Critical Assessment of Their Methodological Quality

    PubMed Central

    2013-01-01

    . While several criteria were met satisfactorily by either all or nearly all reviews, such as the establishment of an a priori design with inclusion and exclusion criteria, use of electronic searches on multiple databases, and reporting of studies characteristics, there were other important areas that needed improvement. Duplicate data extraction, manual searches of highly relevant journals, inclusion of gray and non-English literature, assessment of the methodological quality of included studies and quality of evidence were key methodological procedures that were performed infrequently. Furthermore, certain methodological limitations identified in the synthesis of study results have affected the results and conclusions of some reviews. Conclusions Despite the availability of methodological guidelines that can be utilized to guide the proper conduct of systematic reviews and meta-analyses and eliminate potential risks of bias, this knowledge has not yet been fully integrated in the area of home telemonitoring. Further efforts should be made to improve the design, conduct, reporting, and publication of systematic reviews and meta-analyses in this area. PMID:23880072

  16. One Controller at a Time (1-CAT): A mimo design methodology

    NASA Technical Reports Server (NTRS)

    Mitchell, J. R.; Lucas, J. C.

    1987-01-01

    The One Controller at a Time (1-CAT) methodology for designing digital controllers for Large Space Structures (LSS's) is introduced and illustrated. The flexible mode problem is first discussed. Next, desirable features of a LSS control system design methodology are delineated. The 1-CAT approach is presented, along with an analytical technique for carrying out the 1-CAT process. Next, 1-CAT is used to design digital controllers for the proposed Space Based Laser (SBL). Finally, the SBL design is evaluated for dynamical performance, noise rejection, and robustness.

  17. Indigenous health program evaluation design and methods in Australia: a systematic review of the evidence.

    PubMed

    Lokuge, Kamalini; Thurber, Katherine; Calabria, Bianca; Davis, Meg; McMahon, Kathryn; Sartor, Lauren; Lovett, Raymond; Guthrie, Jill; Banks, Emily

    2017-10-01

    Indigenous Australians experience a disproportionately higher burden of disease compared to non-Indigenous Australians. High-quality evaluation of Indigenous health programs is required to inform health and health services improvement. We aimed to quantify methodological and other characteristics of Australian Indigenous health program evaluations published in the peer-reviewed literature. Systematic review of peer-reviewed literature (November 2009-2014) on Indigenous health program evaluation. We identified 118 papers describing evaluations of 109 interventions; 72.0% were university/research institution-led. 82.2% of evaluations included a quantitative component; 49.2% utilised quantitative data only and 33.1% used both quantitative and qualitative data. The most common design was a before/after comparison (30.5%, n=36/118). 7.6% of studies (n=9/118) used an experimental design: six individual-level and three cluster-randomised controlled trials. 56.8% (67/118) reported on service delivery/process outcomes (versus health or health risk factor outcomes) only. Given the number of Indigenous health programs that are implemented, few evaluations overall are published in the peer-reviewed literature and, of these, few use optimal methodologies such as mixed methods and experimental design. Implications for public health: Multiple strategies are required to increase high-quality, accessible evaluation in Indigenous health, including supporting stronger research-policy-practice partnerships and capacity building for evaluation by health services and government. © 2017 The Authors.

  18. Publications by the American Academy of Pediatrics Section on Urology: the quality of research design and statistical methodology.

    PubMed

    Afshar, K; Jafari, S; Seth, A; Lee, J K; MacNeily, A E

    2009-10-01

    We provide a systematic assessment of the quality of research methodology, statistical analysis and reporting in 2 recent pediatric supplements of The Journal of Urology. All original clinical publications in 2 Pediatric Supplements of The Journal of Urology (2005 and 2007) were identified for formal review. We collected data on variables indicating the quality of methodology and statistical analysis. Two independent reviewers with formal training in clinical epidemiology reviewed each article. Of the 103 published articles 92 met study inclusion criteria. Common study designs included a retrospective cohort in 68% of articles and a prospective cohort in 17%. Demographic statistics were incomplete in many articles, that is in 24% no measure of central tendency and in 18% no measures of dispersion were provided. In 40% of articles the statistical methods were not clearly described. Of all studies eligible for univariate or multivariate analysis only 52% and 23%, respectively, provided the appropriate analysis. Deficiencies in reporting and interpreting p values, ORs/RRs and CIs were noted in 53%, 83% and 78% of studies, respectively. Limitations of studies, such as biases and confounders, were only acknowledged in a third of articles. Comparison of articles published in 2005 vs 2007 revealed a significant improvement in reporting the results of multivariate analysis (p = 0.0297). Methodological and statistical shortcomings were common in our sampling of the pediatric urology literature. This may result in misleading conclusions. Pediatric urologists are encouraged to involve colleagues with formal training in research design from the outset of their studies.

  19. [Marxism as a theoretical and methodological framework in collective health: implications for systematic review and synthesis of evidence].

    PubMed

    Soares, Cassia Baldini; Campos, Celia Maria Sivalli; Yonekura, Tatiana

    2013-12-01

    In this study, we discuss the integration in systematic reviews of research developed from a Marxist perspective of knowledge production and their results as evidence in healthcare. The study objectives are to review the assumptions of dialectical and historical materialism (DHM) and discuss the implications of dialectics for a literature review and the synthesis of evidence. DHM is a powerful framework for knowledge generation and transformation of policies and practices in healthcare. It assumes that social contradictions underlie the health-disease process, the fundamental theoretical construction in the field of collective health. Currently, we observe a considerable influence of the critical paradigm, of Marxist origin, in the construction of knowledge in health. Studies based on this critical paradigm incorporate complex methods, which are inherent to the guidelines of dialect, to identify the object and arrive at results that constitute evidence in healthcare. Systematic reviews should address the methodological difficulties associated with entirely integrating these results to healthcare.

  20. Social Return on Investment (SROI) methodology to account for value for money of public health interventions: a systematic review.

    PubMed

    Banke-Thomas, Aduragbemi Oluwabusayo; Madaj, Barbara; Charles, Ameh; van den Broek, Nynke

    2015-06-24

    Increased scarcity of public resources has led to a concomitant drive to account for value-for-money of interventions. Traditionally, cost-effectiveness, cost-utility and cost-benefit analyses have been used to assess value-for-money of public health interventions. The social return on investment (SROI) methodology has capacity to measure broader socio-economic outcomes, analysing and computing views of multiple stakeholders in a singular monetary ratio. This review provides an overview of SROI application in public health, explores lessons learnt from previous studies and makes recommendations for future SROI application in public health. A systematic review of peer-reviewed and grey literature to identify SROI studies published between January 1996 and December 2014 was conducted. All articles describing conduct of public health SROI studies and which reported a SROI ratio were included. An existing 12-point framework was used to assess study quality. Data were extracted using pre-developed codes: SROI type, type of commissioning organisation, study country, public health area in which SROI was conducted, stakeholders included in study, discount rate used, SROI ratio obtained, time horizon of analysis and reported lessons learnt. 40 SROI studies, of varying quality, including 33 from high-income countries and 7 from low middle-income countries, met the inclusion criteria. SROI application increased since its first use in 2005 until 2011, declining afterwards. SROI has been applied across different public health areas including health promotion (12 studies), mental health (11), sexual and reproductive health (6), child health (4), nutrition (3), healthcare management (2), health education and environmental health (1 each). Qualitative and quantitative methods have been used to gather information for public health SROI studies. However, there remains a lack of consensus on who to include as beneficiaries, how to account for counterfactual and appropriate study

  1. Methodological Quality and Reporting of Generalized Linear Mixed Models in Clinical Medicine (2000–2012): A Systematic Review

    PubMed Central

    Casals, Martí; Girabent-Farrés, Montserrat; Carrasco, Josep L.

    2014-01-01

    Background Modeling count and binary data collected in hierarchical designs have increased the use of Generalized Linear Mixed Models (GLMMs) in medicine. This article presents a systematic review of the application and quality of results and information reported from GLMMs in the field of clinical medicine. Methods A search using the Web of Science database was performed for published original articles in medical journals from 2000 to 2012. The search strategy included the topic “generalized linear mixed models”,“hierarchical generalized linear models”, “multilevel generalized linear model” and as a research domain we refined by science technology. Papers reporting methodological considerations without application, and those that were not involved in clinical medicine or written in English were excluded. Results A total of 443 articles were detected, with an increase over time in the number of articles. In total, 108 articles fit the inclusion criteria. Of these, 54.6% were declared to be longitudinal studies, whereas 58.3% and 26.9% were defined as repeated measurements and multilevel design, respectively. Twenty-two articles belonged to environmental and occupational public health, 10 articles to clinical neurology, 8 to oncology, and 7 to infectious diseases and pediatrics. The distribution of the response variable was reported in 88% of the articles, predominantly Binomial (n = 64) or Poisson (n = 22). Most of the useful information about GLMMs was not reported in most cases. Variance estimates of random effects were described in only 8 articles (9.2%). The model validation, the method of covariate selection and the method of goodness of fit were only reported in 8.0%, 36.8% and 14.9% of the articles, respectively. Conclusions During recent years, the use of GLMMs in medical literature has increased to take into account the correlation of data when modeling qualitative data or counts. According to the current recommendations, the quality of

  2. Methodological quality of systematic reviews and clinical trials on women's health published in a Brazilian evidence-based health journal

    PubMed Central

    Macedo, Cristiane Rufino; Riera, Rachel; Torloni, Maria Regina

    2013-01-01

    OBJECTIVES: To assess the quality of systematic reviews and clinical trials on women's health recently published in a Brazilian evidence-based health journal. METHOD: All systematic reviews and clinical trials on women's health published in the last five years in the Brazilian Journal of Evidence-based Health were retrieved. Two independent reviewers critically assessed the methodological quality of reviews and trials using AMSTAR and the Cochrane Risk of Bias Table, respectively. RESULTS: Systematic reviews and clinical trials accounted for less than 10% of the 61 original studies on women's health published in the São Paulo Medical Journal over the last five years. All five reviews were considered to be of moderate quality; the worst domains were publication bias and the appropriate use of study quality in formulating conclusions. All three clinical trials were judged to have a high risk of bias. The participant blinding, personnel and outcome assessors and allocation concealment domains had the worst scores. CONCLUSIONS: Most of the systematic reviews and clinical trials on women's health recently published in a Brazilian evidence-based journal are of low to moderate quality. The quality of these types of studies needs improvement. PMID:23778332

  3. Application of an integrated flight/propulsion control design methodology to a STOVL aircraft

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Mattern, Duane L.

    1991-01-01

    The application of an emerging Integrated Flight/Propulsion Control design methodology to a STOVL aircraft in transition flight is reported. The methodology steps consist of: (1) design of a centralized feedback controller to provide command tracking and stability and performance robustness considering the fully integrated airframe/propulsion model as one high-order system; (2) partition of the centralized controller into a decentralized, hierarchical form compatible with implementation requirements; and (3) design of command shaping prefilters from pilot control effectors to commanded variables to provide the overall desired response to pilot inputs. Intermediate design results using this methodology are presented, the complete point control design with the propulsion system operating schedule and limit protection logic included is evaluated for sample pilot control inputs, and the response is compared with that of an 'ideal response model' derived from Level I handling qualities requirements.

  4. Development of a combustor analytical design methodology for liquid rocket engines

    NASA Technical Reports Server (NTRS)

    Pieper, Jerry L.; Muss, Jeff

    1989-01-01

    The development of a user friendly computerized methodology for the design and analysis of liquid propellant rocket engine combustion chambers is described. An overview of the methodology, consisting of a computer program containing an appropriate modular assembly of existing industry wide performance and combustion stability models, is presented. These models are linked with an interactive front end processor enabling the user to define the performance and stability traits of an existing design (point analysis) or to create the essential design features of a combustor to meet specific performance goals and combustion stability (point design). Plans for demonstration and verification of this methodology are also presented. These plans include the creation of combustor designs using the methodology, together with predictions of the performance and combustion stability for each design. A verification test program of 26 hot fire tests with up to four designs created using this methodology is described. This testing is planned using LOX/RP-1 propellants with a thrust level of approx. 220,000 N (50,000 lbf).

  5. Software Design Methodology Migration for a Distributed Ground System

    NASA Technical Reports Server (NTRS)

    Ritter, George; McNair, Ann R. (Technical Monitor)

    2002-01-01

    The Marshall Space Flight Center's (MSFC) Payload Operations Center (POC) ground system has been developed and has evolved over a period of about 10 years. During this time the software processes have migrated from more traditional to more contemporary development processes. The new Software processes still emphasize requirements capture, software configuration management, design documenting, and making sure the products that have been developed are accountable to initial requirements. This paper will give an overview of how the Software Process have evolved highlighting the positives as well as the negatives. In addition, we will mention the COTS tools that have been integrated into the processes and how the COTS have provided value to the project .

  6. Methodological criteria for the assessment of moderators in systematic reviews of randomised controlled trials: a consensus study

    PubMed Central

    2011-01-01

    Background Current methodological guidelines provide advice about the assessment of sub-group analysis within RCTs, but do not specify explicit criteria for assessment. Our objective was to provide researchers with a set of criteria that will facilitate the grading of evidence for moderators, in systematic reviews. Method We developed a set of criteria from methodological manuscripts (n = 18) using snowballing technique, and electronic database searches. Criteria were reviewed by an international Delphi panel (n = 21), comprising authors who have published methodological papers in this area, and researchers who have been active in the study of sub-group analysis in RCTs. We used the Research ANd Development/University of California Los Angeles appropriateness method to assess consensus on the quantitative data. Free responses were coded for consensus and disagreement. In a subsequent round additional criteria were extracted from the Cochrane Reviewers' Handbook, and the process was repeated. Results The recommendations are that meta-analysts report both confirmatory and exploratory findings for sub-groups analysis. Confirmatory findings must only come from studies in which a specific theory/evidence based a-priori statement is made. Exploratory findings may be used to inform future/subsequent trials. However, for inclusion in the meta-analysis of moderators, the following additional criteria should be applied to each study: Baseline factors should be measured prior to randomisation, measurement of baseline factors should be of adequate reliability and validity, and a specific test of the interaction between baseline factors and interventions must be presented. Conclusions There is consensus from a group of 21 international experts that methodological criteria to assess moderators within systematic reviews of RCTs is both timely and necessary. The consensus from the experts resulted in five criteria divided into two groups when synthesising evidence: confirmatory

  7. Methodological Quality Assessment of Meta-Analyses and Systematic Reviews of Probiotics in Inflammatory Bowel Disease and Pouchitis

    PubMed Central

    Teng, Guigen; Wei, Tiantong; Gao, Wen; Wang, Huahong

    2016-01-01

    Background Probiotics are widely used for the induction and maintenance of remission in inflammatory bowel disease (IBD) and pouchitis. There are a large number of meta-analyses (MAs)/ systematic reviews (SRs) on this subject, the methodological quality of which has not been evaluated. Objectives This study aimed to evaluate the methodological quality of and summarize the evidence obtained from MAs/SRs of probiotic treatments for IBD and pouchitis patients. Methods The PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched to identify Chinese and English language MAs/SRs of the use of probiotics for IBD and pouchitis. The Assessment of Multiple Systematic Reviews (AMSTAR) scale was used to assess the methodological quality of the studies. Results A total of 36 MAs/SRs were evaluated. The AMSTAR scores of the included studies ranged from 1 to 10, and the average score was 5.81. According to the Canadian Agency for Drugs and Technologies in Health, 4 articles were classified as high quality, 24 articles were classified as moderate quality, and 8 articles were classified as low quality. Most of the MAs/SRs suggested that probiotics had potential benefits for patients with ulcerative colitis (UC), but failed to show effectiveness in the induction and maintenance of remission in Crohn’s disease (CD). The probiotic preparation VSL#3 may play a beneficial role in pouchitis. Conclusion The overall methodological quality of the current MAs/SRs in the field of probiotics for IBD and pouchitis was found to be low to moderate. More MAs/SRs of high quality are required to support using probiotics to treat IBD and pouchitis. PMID:28005973

  8. "Distorted into clarity": a methodological case study illustrating the paradox of systematic review.

    PubMed

    Sandelowski, Margarete; Voils, Corrine I; Barroso, Julie; Lee, Eun-Jeong

    2008-10-01

    Systematic review is typically viewed in the health sciences as the most objective--that is, rigorous, transparent, and reproducible--method for summarizing the results of research. Yet, recent scholarship has shown systematic review to involve feats of interpretation producing less certain, albeit valuable, results. We found this to be the case when we tried to overcome the resistance to synthesis of a set of qualitative and quantitative findings on stigma in HIV-positive women. These findings were difficult to combine largely because of fuzzy conceptualizations of stigma and the volume of unique quantitative findings. Our encounter with findings resistant to synthesis heightened our awareness of the extent to which all systematic reviews are accomplished by practices that paradoxically "distort [research findings] into clarity." (c) 2008 Wiley Periodicals, Inc.

  9. USDA Nutrition Evidence Library: methodology used to identify topics and develop systematic review questions for the birth-to-24-mo population.

    PubMed

    Obbagy, Julie E; Blum-Kemelor, Donna M; Essery, Eve V; Lyon, Joan M G; Spahn, Joanne M

    2014-03-01

    The USDA's Nutrition Evidence Library (NEL) specializes in conducting food- and nutrition-related systematic reviews that are used to inform federal government decision making. To ensure the utility of NEL systematic reviews, the most relevant topics must be addressed, questions must be clearly focused and appropriate in scope, and review frameworks must reflect the state of the science. Identifying the optimal topics and questions requires input from a variety of stakeholders, including scientists with technical expertise, as well as government policy and program leaders. The objective of this article is to describe the rationale and NEL methodology for identifying topics and developing systematic review questions implemented as part of the "Evaluating the evidence base to support the inclusion of infants and children from birth to 24 months of age in the Dietary Guidelines for Americans--the B-24 Project." This is the first phase of a larger project designed to develop dietary guidance for the birth to 24-mo population in the United States.

  10. Weibull-Based Design Methodology for Rotating Aircraft Engine Structures

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin; Hendricks, Robert C.; Soditus, Sherry

    2002-01-01

    The NASA Energy Efficient Engine (E(sup 3)-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life and thus the engine's life is defined by high-cycle fatigue (HCF) or low-cycle fatigue (LCF). Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (95 % probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine maintenance practices without and with refurbishment. respectively. The individual high pressure turbine (HPT) blade lives necessary to obtain a blade system life L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 20,652 and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9 %, the predicted disk system life L(sub 0.1) can vary from 9,408 to 24,911 hr.

  11. Design Methodology for Low-Speed Variable Reluctance Motors

    NASA Astrophysics Data System (ADS)

    Suriano, John Riden

    Lowering the gear reduction in actuators by utilizing high-torque low-speed motors enables the use of less expensive and simpler gear systems and decreases the overall system inertia. Variable reluctance machines can produce high torque at low speeds. Their static torque, a critical quantity for determination of low speed operation, is compared for three variable reluctance motor design variations using linear analysis. Saturation effects, which are crucial to the accurate determination of static torque, are modeled using a dual energy technique first proposed by Lord Rayleigh. Dual energy techniques utilizing flux tubes and magnetomotive force slices are developed into a numerical method for predicting nonlinear three-dimensional magnetostatic field parameters. The dual energy method offers a compromise between the accurate but laborious finite element method and the speed of simplified lumped parameter magnetic circuit calculations. A two-dimensional dual energy model of a variable reluctance motor is developed. Results of calculations on a 4 kW Oulton machine are compared to measurements and other calculation methods. Finally, as a demonstration, the model is used to evaluate two competing variable reluctance motors for use as replacements for a DC windshield wiper motor.

  12. Exercise for Methamphetamine Dependence: Rationale, Design, and Methodology

    PubMed Central

    Mooney, Larissa J.; Cooper, Christopher; London, Edythe; Chudzynski, Joy; Dolezal, Brett; Dickerson, Daniel; Brecht, Mary-Lynn; Penante, Jose; Rawson, Richard A.

    2015-01-01

    Background Effective pharmacotherapies to treat methamphetamine (MA) dependence have not been identified, and behavioral therapies are marginally effective. Based on behavioral studies demonstrating the potential efficacy of aerobic exercise for improving depressive symptoms, anxiety, cognitive deficits, and substance use outcomes, the study described here is examining exercise as a potential treatment for MA-dependent individuals. Methods This study is randomizing 150 participants with MA dependence at a residential treatment facility for addictive disorders to receive either a thrice-weekly structured aerobic and resistance exercise intervention or a health education condition. Recruitment commenced in March, 2010. Enrollment and follow-up phases are ongoing, and recruitment is exceeding targeted enrollment rates. Conclusions Seeking evidence for a possibly effective adjunct to traditional behavioral approaches for treatment of MA dependence, this study is assessing the ability of an 8-week aerobic and resistance exercise protocol to reduce relapse to MA use during a 12-week follow-up period after discharge from residential-based treatment. The study also is evaluating improvements in health and functional outcomes during and after the protocol. This paper describes the design and methods of the study. PMID:24291456

  13. Thermo-mechanical Design Methodology for ITER Cryodistribution cold boxes

    NASA Astrophysics Data System (ADS)

    Shukla, Vinit; Patel, Pratik; Das, Jotirmoy; Vaghela, Hitensinh; Bhattacharya, Ritendra; Shah, Nitin; Choukekar, Ketan; Chang, Hyun-Sik; Sarkar, Biswanath

    2017-04-01

    The ITER cryo-distribution (CD) system is in charge of proper distribution of the cryogen at required mass flow rate, pressure and temperature level to the users; namely the superconducting (SC) magnets and cryopumps (CPs). The CD system is also capable to use the magnet structures as a thermal buffer in order to operate the cryo-plant as much as possible at a steady state condition. A typical CD cold box is equipped with mainly liquid helium (LHe) bath, heat exchangers (HX’s), cryogenic valves, filter, heaters, cold circulator, cold compressor and process piping. The various load combinations which are likely to occur during the life cycle of the CD cold boxes are imposed on the representative model and impacts on the system are analyzed. This study shows that break of insulation vacuum during nominal operation (NO) along with seismic event (Seismic Level-2) is the most stringent load combination having maximum stress of 224 MPa. However, NO+SMHV (Séismes Maximaux Historiquement Vraisemblables = Maximum Historically Probable Earthquakes) load combination is having the least safety margin and will lead the basis of the design of the CD system and its sub components. This paper presents and compares the results of different load combinations which are likely to occur on a typical CD cold box.

  14. Design guided data analysis for summarizing systematic pattern defects and process window

    NASA Astrophysics Data System (ADS)

    Xie, Qian; Venkatachalam, Panneerselvam; Lee, Julie; Chen, Zhijin; Zafar, Khurram

    2016-03-01

    As the semiconductor process technology moves into more advanced nodes, design and process induced systematic defects become increasingly significant yield limiters. Therefore, early detection of these defects is crucial. Focus Exposure Matrix (FEM) and Process Window Qualification (PWQ) are routine methods for discovering systematic patterning defects and establishing the lithography process window. These methods require the stepper to expose a reticle onto the wafer at various focus and exposure settings (also known as modulations). The wafer is subsequently inspected by a bright field, broadband plasma or an E-Beam Inspection tool using a high sensitivity inspection recipe (i.e. hot scan) that often reports a million or more defects. Analyzing this vast stream of data to identify the weak patterns and arrive at the optimal focus/exposure settings requires a significant amount of data reduction through aggressive sampling and nuisance filtering schemes. However, these schemes increase alpha risk, i.e. the probability of not catching some systematic or otherwise important defects within a modulation and thus reporting that modulation as a good condition for production wafers. In order to reduce this risk and establish a more accurate process window, we describe a technique that introduces image-and-design integration methodologies into the inspection data analysis workflow. These image-and-design integration methodologies include contour extraction and alignment to design, contour-to-design defect detection, defective/nuisance pattern retrieval, confirmed defective/nuisance pattern overlay with inspection data, and modulation-related weak-pattern ranking. The technique we present provides greater automation, from defect detection to defective pattern retrieval to decision-making steps, that allows for statistically summarized results and increased coverage of the wafer to be achieved without an adverse impact on cycle time. Statistically summarized results, lead

  15. Design-Based Research: Is This a Suitable Methodology for Short-Term Projects?

    ERIC Educational Resources Information Center

    Pool, Jessica; Laubscher, Dorothy

    2016-01-01

    This article reports on a design-based methodology of a thesis in which a fully face-to-face contact module was converted into a blended learning course. The purpose of the article is to report on how design-based phases, in the form of micro-, meso- and macro-cycles were applied to improve practice and to generate design principles. Design-based…

  16. Design-Based Research: Is This a Suitable Methodology for Short-Term Projects?

    ERIC Educational Resources Information Center

    Pool, Jessica; Laubscher, Dorothy

    2016-01-01

    This article reports on a design-based methodology of a thesis in which a fully face-to-face contact module was converted into a blended learning course. The purpose of the article is to report on how design-based phases, in the form of micro-, meso- and macro-cycles were applied to improve practice and to generate design principles. Design-based…

  17. A design methodology for evolutionary air transportation networks

    NASA Astrophysics Data System (ADS)

    Yang, Eunsuk

    The air transportation demand at large hubs in the U.S. is anticipated to double in the near future. Current runway construction plans at selected airports can relieve some capacity and delay problems, but many are doubtful that this solution is sufficient to accommodate the anticipated demand growth in the National Airspace System (NAS). With the worsening congestion problem, it is imperative to seek alternative solutions other than costly runway constructions. In this respect, many researchers and organizations have been building models and performing analyses of the NAS. However, the complexity and size of the problem results in an overwhelming task for transportation system modelers. This research seeks to compose an active design algorithm for an evolutionary airline network model so as to include network specific control properties. An airline network designer, referred to as a network architect, can use this tool to assess the possibilities of gaining more capacity by changing the network configuration. Since the Airline Deregulation Act of 1978, the airline service network has evolved into a distinct Hub-and-Spoke (H&S) network. Enplanement demand on the H&S network is the sum of Origin-Destination (O-D) demand and transfer demand. Even though the flight or enplanement demand is a function of O-D demand and passenger routings on the airline network, the distinction between enplanement and O-D demand is not often made. Instead, many demand forecast practices in current days are based on scale-ups from the enplanements, which include the demand to and from transferring network hubs. Based on this research, it was found that the current demand prediction practice can be improved by dissecting enplanements further into smaller pieces of information. As a result, enplanement demand is decomposed into intrinsic and variable parts. The proposed intrinsic demand model is based on the concept of 'true' O-D demand which includes the direction of each round trip

  18. Cocaine use reduction with buprenorphine (CURB): rationale, design, and methodology.

    PubMed

    Mooney, Larissa J; Nielsen, Suzanne; Saxon, Andrew; Hillhouse, Maureen; Thomas, Christie; Hasson, Albert; Stablein, Don; McCormack, Jennifer; Lindblad, Robert; Ling, Walter

    2013-03-01

    Effective medications to treat cocaine dependence have not been identified. Recent pharmacotherapy trials demonstrate the potential efficacy of buprenorphine (BUP) (alone or with naltrexone) for reducing cocaine use. The National Institute on Drug Abuse Clinical Trials Network (CTN) launched the Cocaine Use Reduction with Buprenorphine (CURB) investigation to examine the safety and efficacy of sublingual BUP (as Suboxone®) in the presence of extended-release injectable naltrexone (XR-NTX, as Vivitrol®) for the treatment of cocaine dependence. This paper describes the design and rationale for this study. This multi-site, double-blind, placebo-controlled study will randomize 300 participants across 11 sites. Participants must meet the DSM-IV criteria for cocaine dependence and past or current opioid dependence or abuse. Participants are inducted onto XR-NTX after self-reporting at least 7 days of abstinence from opioids and tolerating a naloxone challenge followed by oral naltrexone and are then randomly assigned to one of three medication conditions (4 mg BUP, 16 mg BUP, or placebo) for 8 weeks. Participants receive a second injection of XR-NTX 4 weeks after the initial injection, and follow-up visits are scheduled at 1 and 3 months post-treatment. Participants receive weekly cognitive behavioral therapy (CBT). Recruitment commenced in September, 2011. Enrollment, active medication, and follow-up phases are ongoing, and recruitment is exceeding targeted enrollment rates. This research using 2 medications will demonstrate whether BUP, administered in the presence of XR-NTX, reduces cocaine use in adults with cocaine dependence and opioid use disorders and will demonstrate if XR-NTX prevents development of physiologic dependence on BUP. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Theories and Research Methodologies for Design-Based Implementation Research: Examples from Four Cases

    ERIC Educational Resources Information Center

    Russell, Jennifer Lin; Jackson, Kara; Krumm, Andrew E.; Frank, Kenneth A.

    2013-01-01

    Design-Based Implementation Research is the process of engaging "learning scientists, policy researchers, and practitioners in a model of collaborative, iterative, and systematic research and development" designed to address persistent problems of teaching and learning. Addressing persistent problems of teaching and learning requires…

  20. Theories and Research Methodologies for Design-Based Implementation Research: Examples from Four Cases

    ERIC Educational Resources Information Center

    Russell, Jennifer Lin; Jackson, Kara; Krumm, Andrew E.; Frank, Kenneth A.

    2013-01-01

    Design-Based Implementation Research is the process of engaging "learning scientists, policy researchers, and practitioners in a model of collaborative, iterative, and systematic research and development" designed to address persistent problems of teaching and learning. Addressing persistent problems of teaching and learning requires…

  1. Advanced piloted aircraft flight control system design methodology. Volume 2: The FCX flight control design expert system

    NASA Technical Reports Server (NTRS)

    Myers, Thomas T.; Mcruer, Duane T.

    1988-01-01

    The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design states starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. The FCX expert system as presently developed is only a limited prototype capable of supporting basic lateral-directional FCS design activities related to the design example used. FCX presently supports design of only one FCS architecture (yaw damper plus roll damper) and the rules are largely focused on Class IV (highly maneuverable) aircraft. Despite this limited scope, the major elements which appear necessary for application of knowledge-based software concepts to flight control design were assembled and thus FCX represents a prototype which can be tested, critiqued and evolved in an ongoing process of development.

  2. Aerospace engineering design by systematic decomposition and multilevel optimization

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, J.; Barthelemy, J. F. M.; Giles, G. L.

    1984-01-01

    A method for systematic analysis and optimization of large engineering systems, by decomposition of a large task into a set of smaller subtasks that is solved concurrently is described. The subtasks may be arranged in hierarchical levels. Analyses are carried out in each subtask using inputs received from other subtasks, and are followed by optimizations carried out from the bottom up. Each optimization at the lower levels is augmented by analysis of its sensitivity to the inputs received from other subtasks to account for the couplings among the subtasks in a formal manner. The analysis and optimization operations alternate iteratively until they converge to a system design whose performance is maximized with all constraints satisfied. The method, which is still under development, is tentatively validated by test cases in structural applications and an aircraft configuration optimization.

  3. Object-oriented analysis and design: a methodology for modeling the computer-based patient record.

    PubMed

    Egyhazy, C J; Eyestone, S M; Martino, J; Hodgson, C L

    1998-08-01

    The article highlights the importance of an object-oriented analysis and design (OOAD) methodology for the computer-based patient record (CPR) in the military environment. Many OOAD methodologies do not adequately scale up, allow for efficient reuse of their products, or accommodate legacy systems. A methodology that addresses these issues is formulated and used to demonstrate its applicability in a large-scale health care service system. During a period of 6 months, a team of object modelers and domain experts formulated an OOAD methodology tailored to the Department of Defense Military Health System and used it to produce components of an object model for simple order processing. This methodology and the lessons learned during its implementation are described. This approach is necessary to achieve broad interoperability among heterogeneous automated information systems.

  4. Total Synthesis of Vinblastine, Related Natural Products, and Key Analogues and Development of Inspired Methodology Suitable for the Systematic Study of Their Structure–Function Properties

    PubMed Central

    2015-01-01

    Conspectus Biologically active natural products composed of fascinatingly complex structures are often regarded as not amenable to traditional systematic structure–function studies enlisted in medicinal chemistry for the optimization of their properties beyond what might be accomplished by semisynthetic modification. Herein, we summarize our recent studies on the Vinca alkaloids vinblastine and vincristine, often considered as prototypical members of such natural products, that not only inspired the development of powerful new synthetic methodology designed to expedite their total synthesis but have subsequently led to the discovery of several distinct classes of new, more potent, and previously inaccessible analogues. With use of the newly developed methodology and in addition to ongoing efforts to systematically define the importance of each embedded structural feature of vinblastine, two classes of analogues already have been discovered that enhance the potency of the natural products >10-fold. In one instance, remarkable progress has also been made on the refractory problem of reducing Pgp transport responsible for clinical resistance with a series of derivatives made accessible only using the newly developed synthetic methodology. Unlike the removal of vinblastine structural features or substituents, which typically has a detrimental impact, the additions of new structural features have been found that can enhance target tubulin binding affinity and functional activity while simultaneously disrupting Pgp binding, transport, and functional resistance. Already analogues are in hand that are deserving of full preclinical development, and it is a tribute to the advances in organic synthesis that they are readily accessible even on a natural product of a complexity once thought refractory to such an approach. PMID:25586069

  5. A Systematic Review of Brief Functional Analysis Methodology with Typically Developing Children

    ERIC Educational Resources Information Center

    Gardner, Andrew W.; Spencer, Trina D.; Boelter, Eric W.; DuBard, Melanie; Jennett, Heather K.

    2012-01-01

    Brief functional analysis (BFA) is an abbreviated assessment methodology derived from traditional extended functional analysis methods. BFAs are often conducted when time constraints in clinics, schools or homes are of concern. While BFAs have been used extensively to identify the function of problem behavior for children with disabilities, their…

  6. Nominating under Constraints: A Systematic Comparison of Unlimited and Limited Peer Nomination Methodologies in Elementary School

    ERIC Educational Resources Information Center

    Gommans, Rob; Cillessen, Antonius H. N.

    2015-01-01

    Children's peer relationships are frequently assessed with peer nominations. An important methodological issue is whether to collect unlimited or limited nominations. Some researchers have argued that the psychometric differences between both methods are negligible, while others have claimed that one is superior over the other. The current study…

  7. Analysis and Design of Fuselage Structures Including Residual Strength Prediction Methodology

    NASA Technical Reports Server (NTRS)

    Knight, Norman F.

    1998-01-01

    The goal of this research project is to develop and assess methodologies for the design and analysis of fuselage structures accounting for residual strength. Two primary objectives are included in this research activity: development of structural analysis methodology for predicting residual strength of fuselage shell-type structures; and the development of accurate, efficient analysis, design and optimization tool for fuselage shell structures. Assessment of these tools for robustness, efficient, and usage in a fuselage shell design environment will be integrated with these two primary research objectives.

  8. Comparison of methodological quality of positive versus negative comparative studies published in Indian medical journals: a systematic review.

    PubMed

    Charan, Jaykaran; Chaudhari, Mayur; Jackson, Ryan; Mhaskar, Rahul; Reljic, Tea; Kumar, Ambuj

    2015-06-24

    Published negative studies should have the same rigour of methodological quality as studies with positive findings. However, the methodological quality of negative versus positive studies is not known. The objective was to assess the reported methodological quality of positive versus negative studies published in Indian medical journals. A systematic review (SR) was performed of all comparative studies published in Indian medical journals with a clinical science focus and impact factor >1 between 2011 and 2013. The methodological quality of randomised controlled trials (RCTs) was assessed using the Cochrane risk of bias tool, and the Newcastle-Ottawa scale for observational studies. The results were considered positive if the primary outcome was statistically significant and negative otherwise. When the primary outcome was not specified, we used data on the first outcome reported in the history followed by the results section. Differences in various methodological quality domains between positive versus negative studies were assessed by Fisher's exact test. Seven journals with 259 comparative studies were included in this SR. 24% (63/259) were RCTs, 24% (63/259) cohort studies, and 49% (128/259) case-control studies. 53% (137/259) of studies explicitly reported the primary outcome. Five studies did not report sufficient data to enable us to determine if results were positive or negative. Statistical significance was determined by p value in 78.3% (199/254), CI in 2.8% (7/254), both p value and CI in 11.8% (30/254), and only descriptive in 6.3% (16/254) of studies. The overall methodological quality was poor and no statistically significant differences between reporting of methodological quality were detected between studies with positive versus negative findings. There was no difference in the reported methodological quality of positive versus negative studies. However, the uneven reporting of positive versus negative studies (72% vs 28%) indicates a publication

  9. A Step-by-Step Design Methodology for a Base Case Vanadium Redox-Flow Battery

    ERIC Educational Resources Information Center

    Moore, Mark; Counce, Robert M.; Watson, Jack S.; Zawodzinski, Thomas A.; Kamath, Haresh

    2012-01-01

    The purpose of this work is to develop an evolutionary procedure to be used by Chemical Engineering students for the base-case design of a Vanadium Redox-Flow Battery. The design methodology is based on the work of Douglas (1985) and provides a profitability analysis at each decision level so that more profitable alternatives and directions can be…

  10. A Step-by-Step Design Methodology for a Base Case Vanadium Redox-Flow Battery

    ERIC Educational Resources Information Center

    Moore, Mark; Counce, Robert M.; Watson, Jack S.; Zawodzinski, Thomas A.; Kamath, Haresh

    2012-01-01

    The purpose of this work is to develop an evolutionary procedure to be used by Chemical Engineering students for the base-case design of a Vanadium Redox-Flow Battery. The design methodology is based on the work of Douglas (1985) and provides a profitability analysis at each decision level so that more profitable alternatives and directions can be…

  11. Designing Trend-Monitoring Sounds for Helicopters: Methodological Issues and an Application

    ERIC Educational Resources Information Center

    Edworthy, Judy; Hellier, Elizabeth; Aldrich, Kirsteen; Loxley, Sarah

    2004-01-01

    This article explores methodological issues in sonification and sound design arising from the design of helicopter monitoring sounds. Six monitoring sounds (each with 5 levels) were tested for similarity and meaning with 3 different techniques: hierarchical cluster analysis, linkage analysis, and multidimensional scaling. In Experiment 1,…

  12. The Mediterranean diet and age-related cognitive functioning: A systematic review of study findings and neuropsychological assessment methodology.

    PubMed

    Knight, Alissa; Bryan, Janet; Murphy, Karen

    2017-10-01

    The primary aims of this review were to identify studies investigating the association between the MedDiet pattern and age-related cognitive function, to determine the current status of knowledge, and to ascertain whether a lack of standardization with the operationalization of age-related cognitive function and differences in the chosen neuropsychological assessment methodology impacted on the results and findings. The systematic review protocol for this paper was carried out following the statement and general principles of PRISMA and the UK Centre for Reviews and Dissemination (CRD). A systematic search of electronic databases yielded two cross-sectional studies, two cross-sectional/prospective studies, and 11 prospective studies for inclusion. Among this group of studies, conflicting results and conclusions regarding the efficacy of the MedDiet as a therapeutic approach for age-related cognitive function were found. Of importance, clear differences among studies in relation to neuropsychological assessment methodology were identified. Such disparity appeared to be one plausible factor contributing to the lack of consensus among study findings. One of the important challenges for future research will be to aim toward some kind of standardized neuropsychological assessment criteria. This type of endeavor will enable the ability to validate with greater confidence, whether or not adherence to a MedDiet does promote benefit for age-related cognitive function.

  13. Social cognition interventions for people with schizophrenia: a systematic review focussing on methodological quality and intervention modality.

    PubMed

    Grant, Nina; Lawrence, Megan; Preti, Antonio; Wykes, Til; Cella, Matteo

    2017-08-01

    People with a diagnosis of schizophrenia have significant social and functional difficulties. Social cognition was found to influences these outcomes and in recent years interventions targeting this domain were developed. This paper reviews the existing literature on social cognition interventions for people with a diagnosis of schizophrenia focussing on: i) comparing focussed (i.e. targeting only one social cognitive domain) and global interventions and ii) studies methodological quality. Systematic search was conducted on PubMed and PsycInfo. Studies were included if they were randomised control trials, participants had a diagnosis of schizophrenia or schizoaffective disorder, and the intervention targeted at least one out of four social cognition domains (i.e. theory of mind, affect recognition, social perception and attribution bias). All papers were assessed for methodological quality. Information on the intervention, control condition, study methodology and the main findings from each study were extracted and critically summarised. Data from 32 studies fulfilled the inclusion criteria, considering a total of 1440 participants. Taking part in social cognition interventions produced significant improvements in theory of mind and affect recognition compared to both passive and active control conditions. Results were less clear for social perception and attributional bias. Focussed and global interventions had similar results on outcomes. Overall study methodological quality was modest. There was very limited evidence showing that social cognitive intervention result in functional outcome improvement. The evidence considered suggests that social cognition interventions may be a valuable approach for people with a diagnosis of schizophrenia. However, evidence quality is limited by measure heterogeneity, modest study methodology and short follow-up periods. The findings point to a number of recommendations for future research, including measurement standardisation

  14. Three-dimensional viscous design methodology for advanced technology aircraft supersonic inlet systems

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.

    1983-01-01

    A broad program to develop advanced, reliable, and user oriented three-dimensional viscous design techniques for supersonic inlet systems, and encourage their transfer into the general user community is discussed. Features of the program include: (1) develop effective methods of computing three-dimensional flows within a zonal modeling methodology; (2) ensure reasonable agreement between said analysis and selective sets of benchmark validation data; (3) develop user orientation into said analysis; and (4) explore and develop advanced numerical methodology.

  15. Advanced piloted aircraft flight control system design methodology. Volume 1: Knowledge base

    NASA Technical Reports Server (NTRS)

    Mcruer, Duane T.; Myers, Thomas T.

    1988-01-01

    The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design stages starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. While theory and associated computational means are an important aspect of the design methodology, the lore, knowledge and experience elements, which guide and govern applications are critical features. This material is presented as summary tables, outlines, recipes, empirical data, lists, etc., which encapsulate a great deal of expert knowledge. Much of this is presented in topical knowledge summaries which are attached as Supplements. The composite of the supplements and the main body elements constitutes a first cut at a a Mark 1 Knowledge Base for manned-aircraft flight control.

  16. The inclusion of ergonomic tools in the informational, conceptual and preliminary phases of the product design methodology.

    PubMed

    Medeiros, Ivan Luiz de; Batiz, Eduardo Concepción

    2012-01-01

    The process of product development has received special attention as it is being recognized as a source of competitive gain. Through its systematic use companies reduce costs, increase quality and decrease development time. However, one can find products being launched on the market that cause dissatisfaction to its users, and in consequence if the customer feels harmed or injured he will no longer purchase a product from the same brand. This in regard only to the commercial aspect; usually the danger of an accident or injury is not even thought about. This paper is the basis of the dissertation master's degree and used a literature research to build the repertoire, analyzing the methodologies applied by product design engineers, designers and ergonomists. The analysis results demonstrate the inefficiency of the design methodologies ergonomic issues. The contribution of this work lies in the suggestion to include ergonomic tools in all phases of product development and the presentation of a table with the tools that points out its most suitable time of application and results.

  17. Integrated Controls-Structures Design Methodology: Redesign of an Evolutionary Test Structure

    NASA Technical Reports Server (NTRS)

    Maghami, Peiman G.; Gupta, Sandeep; Elliot, Kenny B.; Joshi, Suresh M.

    1997-01-01

    An optimization-based integrated controls-structures design methodology for a class of flexible space structures is described, and the phase-0 Controls-Structures-Integration evolutionary model, a laboratory testbed at NASA Langley, is redesigned using this integrated design methodology. The integrated controls-structures design is posed as a nonlinear programming problem to minimize the control effort required to maintain a specified line-of-sight pointing performance, under persistent white noise disturbance. Static and dynamic dissipative control strategies are employed for feedback control, and parameters of these controllers are considered as the control design variables. Sizes of strut elements in various sections of the CEM are used as the structural design variables. Design guides for the struts are developed and employed in the integrated design process, to ensure that the redesigned structure can be effectively fabricated. The superiority of the integrated design methodology over the conventional design approach is demonstrated analytically by observing a significant reduction in the average control power needed to maintain specified pointing performance with the integrated design approach.

  18. Patient education in osteoporosis prevention: a systematic review focusing on methodological quality of randomised controlled trials.

    PubMed

    Morfeld, Jana-Carina; Vennedey, Vera; Müller, Dirk; Pieper, Dawid; Stock, Stephanie

    2017-02-24

    This review summarizes evidence regarding the effects of patient education in osteoporosis prevention and treatment. The included studies reveal mixed results on a variety of endpoints. Methodological improvem ent of future RCTs (e.g. with regard to randomization and duration of follow-up) might yield more conclusive evidence on the effects of patient education in osteoporosis INTRODUCTION: This review aims to evaluate the effects of patient education on osteoporosis prevention and treatment results.

  19. Using QALYs in telehealth evaluations: a systematic review of methodology and transparency

    PubMed Central

    2014-01-01

    Background The quality-adjusted life-year (QALY) is a recognised outcome measure in health economic evaluations. QALY incorporates individual preferences and identifies health gains by combining mortality and morbidity into one single index number. A literature review was conducted to examine and discuss the use of QALYs to measure outcomes in telehealth evaluations. Methods Evaluations were identified via a literature search in all relevant databases. Only economic evaluations measuring both costs and QALYs using primary patient level data of two or more alternatives were included. Results A total of 17 economic evaluations estimating QALYs were identified. All evaluations used validated generic health related-quality of life (HRQoL) instruments to describe health states. They used accepted methods for transforming the quality scores into utility values. The methodology used varied between the evaluations. The evaluations used four different preference measures (EQ-5D, SF-6D, QWB and HUI3), and utility scores were elicited from the general population. Most studies reported the methodology used in calculating QALYs. The evaluations were less transparent in reporting utility weights at different time points and variability around utilities and QALYs. Few made adjustments for differences in baseline utilities. The QALYs gained in the reviewed evaluations varied from 0.001 to 0.118 in implying a small but positive effect of telehealth intervention on patient’s health. The evaluations reported mixed cost-effectiveness results. Conclusion The use of QALYs in telehealth evaluations has increased over the last few years. Different methodologies and utility measures have been used to calculate QALYs. A more harmonised methodology and utility measure is needed to ensure comparability across telehealth evaluations. PMID:25086443

  20. Methodology for the optimal design of an integrated first and second generation ethanol production plant combined with power cogeneration.

    PubMed

    Bechara, Rami; Gomez, Adrien; Saint-Antonin, Valérie; Schweitzer, Jean-Marc; Maréchal, François

    2016-08-01

    The application of methodologies for the optimal design of integrated processes has seen increased interest in literature. This article builds on previous works and applies a systematic methodology to an integrated first and second generation ethanol production plant with power cogeneration. The methodology breaks into process simulation, heat integration, thermo-economic evaluation, exergy efficiency vs. capital costs, multi-variable, evolutionary optimization, and process selection via profitability maximization. Optimization generated Pareto solutions with exergy efficiency ranging between 39.2% and 44.4% and capital costs from 210M$ to 390M$. The Net Present Value was positive for only two scenarios and for low efficiency, low hydrolysis points. The minimum cellulosic ethanol selling price was sought to obtain a maximum NPV of zero for high efficiency, high hydrolysis alternatives. The obtained optimal configuration presented maximum exergy efficiency, hydrolyzed bagasse fraction, capital costs and ethanol production rate, and minimum cooling water consumption and power production rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Clinical tests of the sacroiliac joint. A systematic methodological review. Part 1: Reliability.

    PubMed

    van der Wurff, P; Hagmeijer, R H; Meyne, W

    2000-02-01

    In the literature concerning the sacroiliac joint (SIJ) there are numerous specific tests used to detect joint mobility or pain provocation. In this article the authors have reviewed 11 studies which investigated the reliability of these tests. The methodological quality of the studies was tested by a list of criteria developed by the authors. This list consisted of three categories: (1) study population, (2) test procedures and (3) test results. To each criterion a weighting was attached. The methodological score for nine out of the 11 studies was found to be acceptable. The results of this review, however, could not demonstrate reliable outcomes and therefore no evidence on which to base acceptance of mobility tests of the SIJ into daily clinical practice. There are no indications that 'upgrading' of methodological quality would have improved the final conclusions. With respect to pain provocation tests, the findings did not show the same trend. Two studies demonstrated reliable results using the Gaenslen test and the Thigh thrust test. One study showed acceptable reliability for five other pain provocation tests; however, since other authors have described contradictory results, there is a necessity for further research in this area with an emphasis on multiple test scores and pain provocation tests of the SIJ.

  2. Co-design of RAD and ETHICS methodologies: a combination of information system development methods

    NASA Astrophysics Data System (ADS)

    Nasehi, Arezo; Shahriyari, Salman

    2011-12-01

    Co-design is a new trend in the social world which tries to capture different ideas in order to use the most appropriate features for a system. In this paper, co-design of two information system methodologies is regarded; rapid application development (RAD) and effective technical and human implementation of computer-based systems (ETHICS). We tried to consider the characteristics of these methodologies to see the possibility of having a co-design or combination of them for developing an information system. To reach this purpose, four different aspects of them are analyzed: social or technical approach, user participation and user involvement, job satisfaction, and overcoming change resistance. Finally, a case study using the quantitative method is analyzed in order to examine the possibility of co-design using these factors. The paper concludes that RAD and ETHICS are appropriate to be co-designed and brings some suggestions for the co-design.

  3. The Maltreatment-Offending Association: A Systematic Review of the Methodological Features of Prospective and Longitudinal Studies.

    PubMed

    Malvaso, Catia Gaetana; Delfabbro, Paul; Day, Andrew

    2015-12-09

    Although the association between childhood maltreatment and the subsequent development of offending behavior is well documented, the association does not necessarily reflect a causal relationship. This paper provides a systematic review of prospective and longitudinal studies using official records of maltreatment to gain insights into the extent to which methodological variations are likely to influence the conclusions drawn about the likely relationship between maltreatment and offending. Sixty-two original studies met the inclusion criteria. These studies were assessed according to a set of seven methodological criteria: (1) inclusion of comparison groups, (2) the use of statistical controls, (3) valid outcome measures, (4) operationalization of maltreatment, (5) proper temporal order of associations, (6) data relating to unsubstantiated maltreatment, and (7) consideration of mediating and moderating factors. The strength of evidence in support of the maltreatment-offending association was influenced by a number of methodological factors. Despite the increasing sophistication of studies, there is a need to be mindful of how these factors are taken into account in future research in order to gain a deeper understanding of the adverse consequences of maltreatment and how this might influence outcomes and inform interventions.

  4. ACL reconstruction in patients aged 40 years and older: a systematic review and introduction of a new methodology score for ACL studies.

    PubMed

    Brown, Christopher A; McAdams, Timothy R; Harris, Alex H S; Maffulli, Nicola; Safran, Marc R

    2013-09-01

    Treatment of the anterior cruciate ligament (ACL)-deficient knee in older patients remains a core debate. To perform a systematic review of studies that assessed outcomes in patients aged 40 years and older treated with ACL reconstruction and to provide a new methodological scoring system that is directed at critical assessment of studies evaluating ACL surgical outcomes: the ACL Methodology Score (AMS). Systematic review. A comprehensive literature search was performed from 1995 to 2012 using MEDLINE, EMBASE, and Scopus. Inclusion criteria for studies were primary ACL injury, patient age of 40 years and older, and mean follow-up of at least 21 months after reconstruction. Nineteen studies met the inclusion criteria from the 371 abstracts from MEDLINE and 880 abstracts from Scopus. Clinical outcomes (International Knee Documentation Committee [IKDC], Lysholm, and Tegner activity scores), joint stability measures (Lachman test, pivot-shift test, and instrumented knee arthrometer assessment), graft type, complications, and reported chondral or meniscal injury were evaluated in this review. A new methodology scoring system was developed to be specific at critically analyzing ACL outcome studies and used to examine each study design. Nineteen studies describing 627 patients (632 knees; mean age, 49.0 years; range, 42.6-60.0 years) were included in the review. The mean time to surgery was 32.0 months (range, 2.9-88.0 months), with a mean follow-up of 40.2 months (range, 21.0-114.0 months). The IKDC, Lysholm, and Tegner scores and knee laxity assessment indicated favorable results in the studies that reported these outcomes. Patients did not demonstrate a significant difference between graft types and functional outcome scores or stability assessment. The mean AMS was 43.9 ± 7.2 (range, 33.5-57.5). The level of evidence rating did not positively correlate with the AMS, which suggests that the new AMS system may be able to detect errors in methodology or reporting that

  5. Efficient preliminary floating offshore wind turbine design and testing methodologies and application to a concrete spar design

    PubMed Central

    Matha, Denis; Sandner, Frank; Molins, Climent; Campos, Alexis; Cheng, Po Wen

    2015-01-01

    The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design process. In this contribution, a brief review of current floating offshore wind turbine platform pre-design and scaled testing methodologies is provided, with a focus on their ability to accommodate the coupled dynamic behaviour of floating offshore wind systems. The exemplary design and testing methodology for a monolithic concrete spar platform as performed within the European KIC AFOSP project is presented. Results from the experimental tests compared to numerical simulations are presented and analysed and show very good agreement for relevant basic dynamic platform properties. Extreme and fatigue loads and cost analysis of the AFOSP system confirm the viability of the presented design process. In summary, the exemplary application of the reduced design and testing methodology for AFOSP confirms that it represents a viable procedure during pre-design of floating offshore wind turbine platforms. PMID:25583870

  6. Efficient preliminary floating offshore wind turbine design and testing methodologies and application to a concrete spar design.

    PubMed

    Matha, Denis; Sandner, Frank; Molins, Climent; Campos, Alexis; Cheng, Po Wen

    2015-02-28

    The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design process. In this contribution, a brief review of current floating offshore wind turbine platform pre-design and scaled testing methodologies is provided, with a focus on their ability to accommodate the coupled dynamic behaviour of floating offshore wind systems. The exemplary design and testing methodology for a monolithic concrete spar platform as performed within the European KIC AFOSP project is presented. Results from the experimental tests compared to numerical simulations are presented and analysed and show very good agreement for relevant basic dynamic platform properties. Extreme and fatigue loads and cost analysis of the AFOSP system confirm the viability of the presented design process. In summary, the exemplary application of the reduced design and testing methodology for AFOSP confirms that it represents a viable procedure during pre-design of floating offshore wind turbine platforms.

  7. Design for manufacturing: application of collaborative multidisciplinary decision-making methodology

    NASA Astrophysics Data System (ADS)

    Xiao, A.; Seepersad, C. C.; Allen, J. K.; Rosen, D. W.; Mistree, F.

    2007-06-01

    Design for manufacturing is often difficult for mechanical parts, since significant manufacturing knowledge is required to adjust part designs for manufacturability. The traditional trial-and-error approach usually leads to expensive iterations and compromises the quality of the final design. The authors believe the appropriate way to handle product design for manufacturing problems is not to formulate a large design problem that exhaustively incorporates design and manufacturing issues, but to separate the design and manufacturing activities and provide support for collaboration between engineering teams. In this article, the Collaborative Multidisciplinary Decision-making Methodology is used to solve a product design and manufacturing problem. First, the compromise Decision Support Problem is used as a mathematical model of each engineering teams' design decisions and as a medium for information exchange. Second, game-theoretic principles are employed to resolve couplings or interactions between the teams' decisions. Third, design-capability indices are used to maintain design freedom at the early stages of product realization in order to accommodate unexpected downstream design changes. A plastic robot-arm design and manufacturing scenario is presented to demonstrate the application of this methodology and its effectiveness for solving a complex design for manufacturing problem in a streamlined manner, with minimal expensive iterations.

  8. An AMSTAR assessment of the methodological quality of systematic reviews of oral healthcare interventions published in the Journal of Applied Oral Science (JAOS)

    PubMed Central

    SEQUEIRA-BYRON, Patrick; FEDOROWICZ, Zbys; JAGANNATH, Vanitha A.; SHARIF, Mohammad Owaise

    2011-01-01

    Background Systematic reviews are not an assembly of anecdotes but a distillation of current best available evidence on a particular topic and as such have an important role to play in evidence-based healthcare. A substantial proportion of these systematic reviews focus on interventions, and are able to provide clinicians with the opportunity to understand and translate the best available evidence on the effects of these healthcare interventions into clinical practice. The importance of systematic reviews in summarising and identifying the gaps in evidence which might inform new research initiatives is also widely acknowledged. Their potential impact on practice and research makes their methodological quality especially important as it may directly influence their utility for clinicians, patients and policy makers. The objectives of this study were to identify systematic reviews of oral healthcare interventions published in the Journal of Applied Oral Science (JAOS) and to evaluate their methodological quality using the evaluation tool, AMSTAR. Methods Potentially eligible systematic reviews in JAOS were identified through an electronic search of the Scientific Electronic Library Online (SciELO). Details of the relevant aspects of methodology as reported in these systematic reviews were extracted from the full text publications. Methodological quality was assessed independently by two reviewers using the AMSTAR questionnaire. Results Five systematic reviews were identified, one of which was subsequently excluded as it was a review of a diagnostic test. Summary AMSTAR scores for the four included reviews were: 1, 5, 2 and 4 out of a maximum score of 11 (range 1-5, mean 3) with only one of the reviews scoring 5. Conclusion AMSTAR evaluation of the methodological quality of the relatively small number of systematic reviews published in JAOS illustrated that there was room for improvement. Pre-publication and editorial appraisal of future systematic reviews might

  9. Passive and semi-active heave compensator: Project design methodology and control strategies.

    PubMed

    Cuellar Sanchez, William Humberto; Linhares, Tássio Melo; Neto, André Benine; Fortaleza, Eugênio Libório Feitosa

    2017-01-01

    Heave compensator is a system that mitigates transmission of heave movement from vessels to the equipment in the vessel. In drilling industry, a heave compensator enables drilling in offshore environments. Heave compensator attenuates movement transmitted from the vessel to the drill string and drill bit ensuring security and efficiency of the offshore drilling process. Common types of heave compensators are passive, active and semi-active compensators. This article presents 4 main points. First, a bulk modulus analysis obtains a simple condition to determine if the bulk modulus can be neglected in the design of hydropneumatic passive heave compensator. Second, the methodology to design passive heave compensators with the desired frequency response. Third, four control methodologies for semi-active heave compensator are tested and compared numerically. Lastly, we show experimental results obtained from a prototype with the methodology developed to design passive heave compensator.

  10. Passive and semi-active heave compensator: Project design methodology and control strategies

    PubMed Central

    Cuellar Sanchez, William Humberto; Neto, André Benine; Fortaleza, Eugênio Libório Feitosa

    2017-01-01

    Heave compensator is a system that mitigates transmission of heave movement from vessels to the equipment in the vessel. In drilling industry, a heave compensator enables drilling in offshore environments. Heave compensator attenuates movement transmitted from the vessel to the drill string and drill bit ensuring security and efficiency of the offshore drilling process. Common types of heave compensators are passive, active and semi-active compensators. This article presents 4 main points. First, a bulk modulus analysis obtains a simple condition to determine if the bulk modulus can be neglected in the design of hydropneumatic passive heave compensator. Second, the methodology to design passive heave compensators with the desired frequency response. Third, four control methodologies for semi-active heave compensator are tested and compared numerically. Lastly, we show experimental results obtained from a prototype with the methodology developed to design passive heave compensator. PMID:28813494

  11. Simplifying multiobjective optimization: An automated design methodology for the nondominated sorted genetic algorithm-II

    NASA Astrophysics Data System (ADS)

    Reed, Patrick; Minsker, Barbara S.; Goldberg, David E.

    2003-07-01

    Many water resources problems require careful balancing of fiscal, technical, and social objectives. Informed negotiation and balancing of objectives can be greatly aided through the use of evolutionary multiobjective optimization (EMO) algorithms, which can evolve entire tradeoff (or Pareto) surfaces within a single run. The primary difficulty in using these methods lies in the large number of parameters that must be specified to ensure that these algorithms effectively quantify design tradeoffs. This technical note addresses this difficulty by introducing a multipopulation design methodology that automates parameter specification for the nondominated sorted genetic algorithm-II (NSGA-II). The NSGA-II design methodology is successfully demonstrated on a multiobjective long-term groundwater monitoring application. Using this methodology, multiobjective optimization problems can now be solved automatically with only a few simple user inputs.

  12. Study designs and systematic reviews of interventions: building evidence across study designs.

    PubMed

    Sargeant, J M; Kelton, D F; O'Connor, A M

    2014-06-01

    This article is the second article in a series of six focusing on systematic reviews in animal agriculture and veterinary medicine. This article addresses the strengths and limitations of study designs commonly used in animal agriculture and veterinary research to assess interventions (preventive or therapeutic treatments) and discusses the appropriateness of their use in systematic reviews of interventions. Different study designs provide different evidentiary value for addressing questions about the efficacy of interventions. Experimental study designs range from in vivo proof of concept experiments to randomized controlled trials (RCTs) under real-world conditions. The key characteristic of experimental design in intervention studies is that the investigator controls the allocation of individuals or groups to different intervention strategies. The RCT is considered the gold standard for evaluating the efficacy of interventions and, if there are well-executed RCTs available for inclusion in a systematic review, that review may be restricted to only this design. In some instances, RCTs may not be feasible or ethical to perform, and there are fewer RCTs published in the veterinary literature compared to the human healthcare literature. Therefore, observational study designs, where the investigator does not control intervention allocation, may provide the only available evidence of intervention efficacy. While observational studies tend to be relevant to real-world use of an intervention, they are more prone to bias. Human healthcare researchers use a pyramid of evidence diagram to describe the evidentiary value of different study designs for assessing interventions. Modifications for veterinary medicine are presented in this article. © 2014 Blackwell Verlag GmbH.

  13. Implications of applying methodological shortcuts to expedite systematic reviews: three case studies using systematic reviews from agri-food public health.

    PubMed

    Pham, Mai T; Waddell, Lisa; Rajić, Andrijana; Sargeant, Jan M; Papadopoulos, Andrew; McEwen, Scott A

    2016-12-01

    The rapid review is an approach to synthesizing research evidence when a shorter timeframe is required. The implications of what is lost in terms of rigour, increased bias and accuracy when conducting a rapid review have not yet been elucidated. We assessed the potential implications of methodological shortcuts on the outcomes of three completed systematic reviews addressing agri-food public health topics. For each review, shortcuts were applied individually to assess the impact on the number of relevant studies included and whether omitted studies affected the direction, magnitude or precision of summary estimates from meta-analyses. In most instances, the shortcuts resulted in at least one relevant study being omitted from the review. The omission of studies affected 39 of 143 possible meta-analyses, of which 14 were no longer possible because of insufficient studies (<2). When meta-analysis was possible, the omission of studies generally resulted in less precise pooled estimates (i.e. wider confidence intervals) that did not differ in direction from the original estimate. The three case studies demonstrated the risk of missing relevant literature and its impact on summary estimates when methodological shortcuts are applied in rapid reviews. © 2016 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd. © 2016 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd.

  14. Systematic reviews of observational studies of risk of thrombosis and bleeding in urological surgery (ROTBUS): introduction and methodology.

    PubMed

    Tikkinen, Kari A O; Agarwal, Arnav; Craigie, Samantha; Cartwright, Rufus; Gould, Michael K; Haukka, Jari; Naspro, Richard; Novara, Giacomo; Sandset, Per Morten; Siemieniuk, Reed A; Violette, Philippe D; Guyatt, Gordon H

    2014-12-23

    Pharmacological thromboprophylaxis in the peri-operative period involves a trade-off between reduction in venous thromboembolism (VTE) and an increase in bleeding. Baseline risks, in the absence of prophylaxis, for VTE and bleeding are known to vary widely between urological procedures, but their magnitude is highly uncertain. Systematic reviews and meta-analyses addressing baseline risks are uncommon, needed, and require methodological innovation. In this article, we describe the rationale and methods for a series of systematic reviews of the risks of symptomatic VTE and bleeding requiring reoperation in urological surgery. We searched MEDLINE from January 1, 2000 until April 10, 2014 for observational studies reporting on symptomatic VTE or bleeding after urological procedures. Additional studies known to experts and studies cited in relevant review articles were added. Teams of two reviewers, independently assessed articles for eligibility, evaluated risk of bias, and abstracted data. We derived best estimates of risk from the median estimates among studies rated at the lowest risk of bias. The primary endpoints were 30-day post-operative risk estimates of symptomatic VTE and bleeding requiring reoperation, stratified by procedure and patient risk factors. This series of systematic reviews will inform clinicians and patients regarding the trade-off between VTE prevention and bleeding. Our work advances standards in systematic reviews of surgical complications, including assessment of risk of bias, criteria for arriving at best estimates of risk (including modeling of timing of events and dealing with suboptimal data reporting), dealing with subgroups at higher and lower risk of bias, and use of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate certainty in estimates of risk. The results will be incorporated in the upcoming European Association Urology Guideline on Thromboprophylaxis. PROSPERO CRD42014010342.

  15. A time-harmonic inverse methodology for the design of RF coils in MRI.

    PubMed

    Lawrence, Ben G; Crozier, Stuart; Yau, Desmond D; Doddrell, David M

    2002-01-01

    An inverse methodology is described to assist in the design of radio-frequency (RF) coils for magnetic resonance imaging (MRI) applications. The time-harmonic electromagnetic Green's functions are used to calculate current on the coil and shield cylinders that will generate a specified internal magnetic field. Stream function techniques and the method of moments are then used to implement this theoretical current density into an RF coil. A novel asymmetric coil operating for a 4.5 T MRI machine was designed and constructed using this methodology and the results are presented.

  16. Energy-Based Design Methodology for Air Vehicle Systems: Aerodynamic Correlation Study

    DTIC Science & Technology

    2005-03-01

    ENERGY -BASED DESIGN METHODOLOGY FOR AIR VEHICLE SYSTEMS : AERODYNAMIC CORRELATION STUDY AFOSR: FA9550-64-"t/Dr. John Schmisseur AFOSR-NA C>(4-1-0- I...drag estimation and vehicle-level utilization of energy . The exergy utilization of a wing in a steady, low subsonic, three-dimensional, viscous flow...5a. CONTRACT NUMBER Energy -Based Design Methodology For Air Vehicle 5b. GRANT NUMBER Systems : Aerodynamic Correlation Study FA9550,-64 (9 4-1-- !(1 5c

  17. A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies.

    PubMed

    Ogoma, Sheila B; Moore, Sarah J; Maia, Marta F

    2012-12-07

    Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control.

  18. A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies

    PubMed Central

    2012-01-01

    Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words “Mosquito coils” “Mosquito emanators” and “Spatial repellents”. It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose–response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control. PMID:23216844

  19. Narrowing the focus on the assessment of psychosis-related PTSD: a methodologically orientated systematic review

    PubMed Central

    Fornells-Ambrojo, Miriam; Gracie, Alison; Brewin, Chris R.; Hardy, Amy

    2016-01-01

    Background Posttraumatic stress disorder (PTSD) in response to psychosis and associated experiences (psychosis-related PTSD, or PR-PTSD) is the subject of a growing field of research. However, a wide range of PR-PTSD prevalence rates has been reported. This may be due to definitional and methodological inconsistencies in the assessment of PR-PTSD. Objective The focus of the review is two-fold. (1) To identify factors that enhance, or detract from, the robustness of PR-PTSD assessment and (2) to critically evaluate the evidence in relation to these identified criteria, including the impact on PR-PTSD prevalence rates. Method Four quality criteria, whose development was informed by mainstream PTSD research, were selected to evaluate findings on PR-PTSD prevalence. Two criteria related to assessment of psychosis-related stressors (participant identification of worst moments of discrete threat events; psychometrically robust trauma measure) and two focussed on PR-PTSD symptom measurement (adequate time elapsed since trauma; use of validated PTSD interview) in the context of psychosis. Results Twenty-one studies of PR-PTSD, with prevalence rates ranging from 11 to 51%, were evaluated. Fourteen studies (67%) used robust PTSD measures but PR-trauma was not specifically defined or assessed with validated measures. Eleven studies (52%) assessed PTSD before sufficient time had elapsed since the trauma. Due to significant methodological limitations, it was not possible to review PR-PTSD rates and provide a revised estimate of prevalence. Conclusions Methodological limitations are common in existing studies of PR-PTSD prevalence. Specific recommendations for improving assessment of psychosis-related trauma are made to guide the development of this new and emerging field. The review concludes with a proposed conceptualisation of PR-PTSD in the context of current diagnostic systems. The utility of the PR-PTSD term and its theoretical underpinnings are discussed. Highlights of

  20. A systematic review of methodology: time series regression analysis for environmental factors and infectious diseases.

    PubMed

    Imai, Chisato; Hashizume, Masahiro

    2015-03-01

    Time series analysis is suitable for investigations of relatively direct and short-term effects of exposures on outcomes. In environmental epidemiology studies, this method has been one of the standard approaches to assess impacts of environmental factors on acute non-infectious diseases (e.g. cardiovascular deaths), with conventionally generalized linear or additive models (GLM and GAM). However, the same analysis practices are often observed with infectious diseases despite of the substantial differences from non-infectious diseases that may result in analytical challenges. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, systematic review was conducted to elucidate important issues in assessing the associations between environmental factors and infectious diseases using time series analysis with GLM and GAM. Published studies on the associations between weather factors and malaria, cholera, dengue, and influenza were targeted. Our review raised issues regarding the estimation of susceptible population and exposure lag times, the adequacy of seasonal adjustments, the presence of strong autocorrelations, and the lack of a smaller observation time unit of outcomes (i.e. daily data). These concerns may be attributable to features specific to infectious diseases, such as transmission among individuals and complicated causal mechanisms. The consequence of not taking adequate measures to address these issues is distortion of the appropriate risk quantifications of exposures factors. Future studies should pay careful attention to details and examine alternative models or methods that improve studies using time series regression analysis for environmental determinants of infectious diseases.

  1. Minimally invasive metabolic testing for malignant hyperthermia susceptibility: a systematic review of the methodology and results.

    PubMed

    Metterlein, Thomas; Schuster, Frank; Kranke, Peter; Roewer, Norbert; Anetseder, Martin

    2010-03-01

    Malignant hyperthermia (MH) is a potentially lethal hypermetabolic syndrome that develops in susceptible individuals exposed to volatile anesthetics or depolarizing neuromuscular blocking agents. Because genetic screening is successful only in 30 - 50% of all suspected cases, contracture testing following an open muscle biopsy is performed to diagnose MH susceptibility. Two different protocols exist, the in vitro contracture test (IVCT) for Europe and the caffine halothane contracture test for the US. As replacement for the IVCT, an in vivo metabolic test might allow an equal discrimination of MH susceptible individuals. In this systematic review, all available metabolic testing methods are analyzed. The reader will gain insight in methods and results of alternative approaches to diagnose MH. Relevant studies involving in vivo metabolic testing were systematically searched (Medline) and reviewed. Their ability to discriminate MH susceptible individuals was analyzed and compared. Any systemic or local side effects were documented and evaluated in order to allow more robust conclusions based on larger sample sizes than the single trials. All discussed study protocols allowed an adequate discrimination of MH susceptible individuals. The latest study protocol reaches a specificity of 79% with a sensitivity of 100%. No severe systemic or local adverse effects could be seen in the pooled analysis. Minimally invasive metabolic testing is a promising novel approach to diagnose MH. Further multi-center studies have to be conducted to optimize the results in order to replace the IVCT.

  2. Methodological considerations in assessment of language lateralisation with fMRI: a systematic review

    PubMed Central

    Bishop, Dorothy V.M.; Woodhead, Zoe V.J.

    2017-01-01

    The involvement of the right and left hemispheres in mediating language functions has been measured in a variety of ways over the centuries since the relative dominance of the left hemisphere was first known. Functional magnetic resonance imaging (fMRI) presents a useful non-invasive method of assessing lateralisation that is being increasingly used in clinical practice and research. However, the methods used in the fMRI laterality literature currently are highly variable, making systematic comparisons across studies difficult. Here we consider the different methods of quantifying and classifying laterality that have been used in fMRI studies since 2000, with the aim of determining which give the most robust and reliable measurement. Recommendations are made with a view to informing future research to increase standardisation in fMRI laterality protocols. In particular, the findings reinforce the importance of threshold-independent methods for calculating laterality indices, and the benefits of assessing heterogeneity of language laterality across multiple regions of interest and tasks. This systematic review was registered as a protocol on Open Science Framework: https://osf.io/hyvc4/. PMID:28713656

  3. Space station definitions, design, and development. Task 5: Multiple