Probabilistic evaluation of damage potential in earthquake-induced liquefaction in a 3-D soil deposit

NASA Astrophysics Data System (ADS)

Halder, A.; Miller, F. J.

1982-03-01

A probabilistic model to evaluate the risk of liquefaction at a site and to limit or eliminate damage during earthquake induced liquefaction is proposed. The model is extended to consider three dimensional nonhomogeneous soil properties. The parameters relevant to the liquefaction phenomenon are identified, including: (1) soil parameters; (2) parameters required to consider laboratory test and sampling effects; and (3) loading parameters. The fundamentals of risk based design concepts pertient to liquefaction are reviewed. A detailed statistical evaluation of the soil parameters in the proposed liquefaction model is provided and the uncertainty associated with the estimation of in situ relative density is evaluated for both direct and indirect methods. It is found that the liquefaction potential the uncertainties in the load parameters could be higher than those in the resistance parameters.

Launch Vehicle Propulsion Parameter Design Multiple Selection Criteria

NASA Technical Reports Server (NTRS)

Shelton, Joey Dewayne

2004-01-01

The optimization tool described herein addresses and emphasizes the use of computer tools to model a system and focuses on a concept development approach for a liquid hydrogen/liquid oxygen single-stage-to-orbit system, but more particularly the development of the optimized system using new techniques. This methodology uses new and innovative tools to run Monte Carlo simulations, genetic algorithm solvers, and statistical models in order to optimize a design concept. The concept launch vehicle and propulsion system were modeled and optimized to determine the best design for weight and cost by varying design and technology parameters. Uncertainty levels were applied using Monte Carlo Simulations and the model output was compared to the National Aeronautics and Space Administration Space Shuttle Main Engine. Several key conclusions are summarized here for the model results. First, the Gross Liftoff Weight and Dry Weight were 67% higher for the design case for minimization of Design, Development, Test and Evaluation cost when compared to the weights determined by the minimization of Gross Liftoff Weight case. In turn, the Design, Development, Test and Evaluation cost was 53% higher for optimized Gross Liftoff Weight case when compared to the cost determined by case for minimization of Design, Development, Test and Evaluation cost. Therefore, a 53% increase in Design, Development, Test and Evaluation cost results in a 67% reduction in Gross Liftoff Weight. Secondly, the tool outputs define the sensitivity of propulsion parameters, technology and cost factors and how these parameters differ when cost and weight are optimized separately. A key finding was that for a Space Shuttle Main Engine thrust level the oxidizer/fuel ratio of 6.6 resulted in the lowest Gross Liftoff Weight rather than at 5.2 for the maximum specific impulse, demonstrating the relationships between specific impulse, engine weight, tank volume and tank weight. Lastly, the optimum chamber pressure for Gross Liftoff Weight minimization was 2713 pounds per square inch as compared to 3162 for the Design, Development, Test and Evaluation cost optimization case. This chamber pressure range is close to 3000 pounds per square inch for the Space Shuttle Main Engine.

Aeroelastic considerations for torsionally soft rotors

NASA Technical Reports Server (NTRS)

Mantay, W. R.; Yeager, W. T., Jr.

1985-01-01

A research study was initiated to systematically determine the impact of selected blade tip geometric parameters on conformable rotor performance and loads characteristics. The model articulated rotors included baseline and torsionally soft blades with interchangeable tips. Seven blade tip designs were evaluated on the baseline rotor and six tip designs were tested on the torsionally soft blades. The designs incorporated a systemmatic variation in geometric parameters including sweep, taper, and anhedral. The rotors were evaluated in the NASA Langley Transonic Dynamics Tunnel at several advance ratios, lift and propulsive force values, and tip Mach numbers. A track sensitivity study was also conducted at several advance ratios for both rotors. Based on the test results, tip parameter variations generated significant rotor performance and loads differences for both baseline and torsionally soft blades.

Three-meter telescope study

NASA Technical Reports Server (NTRS)

Wissinger, A.; Scott, R. M.; Peters, W.; Augustyn, W., Jr.; Arnold, R.; Offner, A.; Damast, M.; Boyce, B.; Kinnaird, R.; Mangus, J. D.

1971-01-01

A means is presented whereby the effect of various changes in the most important parameters of a three meter aperature space astronomy telescope can be evaluated to determine design trends and to optimize the optical design configuration. Methods are defined for evaluating the theoretical optical performance of axisymmetric, centrally obscured telescopes based upon the intended astronomy research usage. A series of design parameter variations is presented to determine the optimum telescope configuration. The design optimum requires very fast primary mirrors, so the study also examines the current state of the art in fabricating large, fast primary mirrors. The conclusion is that a 3-meter primary mirror having a focal ratio as low as f/2 is feasible using currently established techniques.

Precipitation-runoff modeling system; user's manual

USGS Publications Warehouse

Leavesley, G.H.; Lichty, R.W.; Troutman, B.M.; Saindon, L.G.

1983-01-01

The concepts, structure, theoretical development, and data requirements of the precipitation-runoff modeling system (PRMS) are described. The precipitation-runoff modeling system is a modular-design, deterministic, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on streamflow, sediment yields, and general basin hydrology. Basin response to normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water balance relationships, flow regimes, flood peaks and volumes, soil-water relationships, sediment yields, and groundwater recharge. Parameter-optimization and sensitivity analysis capabilites are provided to fit selected model parameters and evaluate their individual and joint effects on model output. The modular design provides a flexible framework for continued model system enhancement and hydrologic modeling research and development. (Author 's abstract)

Standard Operating Procedure for Accelerated Corrosion Testing at ARL

DTIC Science & Technology

2017-11-01

report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. Citation of...Parameters 2 4. Evaluation 3 4.1 Preparation for Rating 3 4.2 Evaluation of Creepage from Scribe 3 4.3 Evaluation of Unscribed Areas 4 5...operational parameters of the chamber. Test sample evaluations are explained with respect to both corrosion originating from the scribe and

Design and development of pressure and repressurization purge system for reusable space shuttle multilayer insulation system

NASA Technical Reports Server (NTRS)

1971-01-01

Preliminary design and analysis of purge system concepts and purge subsystem approaches are defined and evaluated. Acceptable purge subsystem approaches were combined into four predesign layouts which are presented for comparison and evaluation. Two predesigns were selected for further detailed design and evaluation for eventual selection of the best design for a full scale test configuration. An operation plan is included as an appendix for reference to shuttle-oriented operational parameters.

Efficient Bayesian experimental design for contaminant source identification

NASA Astrophysics Data System (ADS)

Zhang, Jiangjiang; Zeng, Lingzao; Chen, Cheng; Chen, Dingjiang; Wu, Laosheng

2015-01-01

In this study, an efficient full Bayesian approach is developed for the optimal sampling well location design and source parameters identification of groundwater contaminants. An information measure, i.e., the relative entropy, is employed to quantify the information gain from concentration measurements in identifying unknown parameters. In this approach, the sampling locations that give the maximum expected relative entropy are selected as the optimal design. After the sampling locations are determined, a Bayesian approach based on Markov Chain Monte Carlo (MCMC) is used to estimate unknown parameters. In both the design and estimation, the contaminant transport equation is required to be solved many times to evaluate the likelihood. To reduce the computational burden, an interpolation method based on the adaptive sparse grid is utilized to construct a surrogate for the contaminant transport equation. The approximated likelihood can be evaluated directly from the surrogate, which greatly accelerates the design and estimation process. The accuracy and efficiency of our approach are demonstrated through numerical case studies. It is shown that the methods can be used to assist in both single sampling location and monitoring network design for contaminant source identifications in groundwater.

Fault detection for discrete-time LPV systems using interval observers

NASA Astrophysics Data System (ADS)

Zhang, Zhi-Hui; Yang, Guang-Hong

2017-10-01

This paper is concerned with the fault detection (FD) problem for discrete-time linear parameter-varying systems subject to bounded disturbances. A parameter-dependent FD interval observer is designed based on parameter-dependent Lyapunov and slack matrices. The design method is presented by translating the parameter-dependent linear matrix inequalities (LMIs) into finite ones. In contrast to the existing results based on parameter-independent and diagonal Lyapunov matrices, the derived disturbance attenuation, fault sensitivity and nonnegative conditions lead to less conservative LMI characterisations. Furthermore, without the need to design the residual evaluation functions and thresholds, the residual intervals generated by the interval observers are used directly for FD decision. Finally, simulation results are presented for showing the effectiveness and superiority of the proposed method.

The conical scanner evaluation system design

NASA Technical Reports Server (NTRS)

Cumella, K. E.; Bilanow, S.; Kulikov, I. B.

1982-01-01

The software design for the conical scanner evaluation system is presented. The purpose of this system is to support the performance analysis of the LANDSAT-D conical scanners, which are infrared horizon detection attitude sensors designed for improved accuracy. The system consists of six functionally independent subsystems and five interface data bases. The system structure and interfaces of each of the subsystems is described and the content, format, and file structure of each of the data bases is specified. For each subsystem, the functional logic, the control parameters, the baseline structure, and each of the subroutines are described. The subroutine descriptions include a procedure definition and the input and output parameters.

A Design of Experiments Approach Defining the Relationships Between Processing and Microstructure for Ti-6Al-4V

NASA Technical Reports Server (NTRS)

Wallace, Terryl A.; Bey, Kim S.; Taminger, Karen M. B.; Hafley, Robert A.

2004-01-01

A study was conducted to evaluate the relative significance of input parameters on Ti- 6Al-4V deposits produced by an electron beam free form fabrication process under development at the NASA Langley Research Center. Five input parameters where chosen (beam voltage, beam current, translation speed, wire feed rate, and beam focus), and a design of experiments (DOE) approach was used to develop a set of 16 experiments to evaluate the relative importance of these parameters on the resulting deposits. Both single-bead and multi-bead stacks were fabricated using 16 combinations, and the resulting heights and widths of the stack deposits were measured. The resulting microstructures were also characterized to determine the impact of these parameters on the size of the melt pool and heat affected zone. The relative importance of each input parameter on the height and width of the multi-bead stacks will be discussed. .

Designing a Pediatric Study for an Antimalarial Drug by Using Information from Adults

PubMed Central

Jullien, Vincent; Samson, Adeline; Guedj, Jérémie; Kiechel, Jean-René; Zohar, Sarah; Comets, Emmanuelle

2015-01-01

The objectives of this study were to design a pharmacokinetic (PK) study by using information about adults and evaluate the robustness of the recommended design through a case study of mefloquine. PK data about adults and children were available from two different randomized studies of the treatment of malaria with the same artesunate-mefloquine combination regimen. A recommended design for pediatric studies of mefloquine was optimized on the basis of an extrapolated model built from adult data through the following approach. (i) An adult PK model was built, and parameters were estimated by using the stochastic approximation expectation-maximization algorithm. (ii) Pediatric PK parameters were then obtained by adding allometry and maturation to the adult model. (iii) A D-optimal design for children was obtained with PFIM by assuming the extrapolated design. Finally, the robustness of the recommended design was evaluated in terms of the relative bias and relative standard errors (RSE) of the parameters in a simulation study with four different models and was compared to the empirical design used for the pediatric study. Combining PK modeling, extrapolation, and design optimization led to a design for children with five sampling times. PK parameters were well estimated by this design with few RSE. Although the extrapolated model did not predict the observed mefloquine concentrations in children very accurately, it allowed precise and unbiased estimates across various model assumptions, contrary to the empirical design. Using information from adult studies combined with allometry and maturation can help provide robust designs for pediatric studies. PMID:26711749

Product design for energy reduction in concurrent engineering: An Inverted Pyramid Approach

NASA Astrophysics Data System (ADS)

Alkadi, Nasr M.

Energy factors in product design in concurrent engineering (CE) are becoming an emerging dimension for several reasons; (a) the rising interest in "green design and manufacturing", (b) the national energy security concerns and the dramatic increase in energy prices, (c) the global competition in the marketplace and global climate change commitments including carbon tax and emission trading systems, and (d) the widespread recognition of the need for sustainable development. This research presents a methodology for the intervention of energy factors in concurrent engineering product development process to significantly reduce the manufacturing energy requirement. The work presented here is the first attempt at integrating the design for energy in concurrent engineering framework. It adds an important tool to the DFX toolbox for evaluation of the impact of design decisions on the product manufacturing energy requirement early during the design phase. The research hypothesis states that "Product Manufacturing Energy Requirement is a Function of Design Parameters". The hypothesis was tested by conducting experimental work in machining and heat treating that took place at the manufacturing lab of the Industrial and Management Systems Engineering Department (IMSE) at West Virginia University (WVU) and at a major U.S steel manufacturing plant, respectively. The objective of the machining experiment was to study the effect of changing specific product design parameters (Material type and diameter) and process design parameters (metal removal rate) on a gear head lathe input power requirement through performing defined sets of machining experiments. The objective of the heat treating experiment was to study the effect of varying product charging temperature on the fuel consumption of a walking beams reheat furnace. The experimental work in both directions have revealed important insights into energy utilization in machining and heat-treating processes and its variance based on product, process, and system design parameters. In depth evaluation to how the design and manufacturing normally happen in concurrent engineering provided a framework to develop energy system levels in machining within the concurrent engineering environment using the method of "Inverted Pyramid Approach", (IPA). The IPA features varying levels of output energy based information depending on the input design parameters that is available during each stage (level) of the product design. The experimental work, the in-depth evaluation of design and manufacturing in CE, and the developed energy system levels in machining provided a solid base for the development of the model for the design for energy reduction in CE. The model was used to analyze an example part where 12 evolving designs were thoroughly reviewed to investigate the sensitivity of energy to design parameters in machining. The model allowed product design teams to address manufacturing energy concerns early during the design stage. As a result, ranges for energy sensitive design parameters impacting product manufacturing energy consumption were found in earlier levels. As designer proceeds to deeper levels in the model, this range tightens and results in significant energy reductions.

Bioremediation of chlorpyrifos contaminated soil by two phase bioslurry reactor: Processes evaluation and optimization by Taguchi's design of experimental (DOE) methodology.

PubMed

Pant, Apourv; Rai, J P N

2018-04-15

Two phase bioreactor was constructed, designed and developed to evaluate the chlorpyrifos remediation. Six biotic and abiotic factors (substrate-loading rate, slurry phase pH, slurry phase dissolved oxygen (DO), soil water ratio, temperature and soil micro flora load) were evaluated by design of experimental (DOE) methodology employing Taguchi's orthogonal array (OA). The selected six factors were considered at two levels L-8 array (2^7, 15 experiments) in the experimental design. The optimum operating conditions obtained from the methodology showed enhanced chlorpyrifos degradation from 283.86µg/g to 955.364µg/g by overall 70.34% of enhancement. In the present study, with the help of few well defined experimental parameters a mathematical model was constructed to understand the complex bioremediation process and optimize the approximate parameters upto great accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

Solid state d.c. power controller design philosophies and their evaluation.

NASA Technical Reports Server (NTRS)

Maus, L. G.; Williams, D. E.

1972-01-01

Evaluation of remote power controllers (RPC), which has enhanced knowledge of the capabilities of various design philosophies and has indicated certain limitations that RPC's exhibit. Additionally, this activity has clearly emphasized that certain RPC design parameters merit further consideration in development. The major design parameters to be analyzed in more detail are the rates of change of the rise and fall times of the output current. The major reason why transient voltages and currents should be reduced is the minimization of the reverse collector-to-emitter voltage. The requirement for higher bus voltage coupled with the present problem of improving the efficiency of power control points out the urgent need for improvement and advancement of higher current, voltage, and gain power semiconductors.

An optimal system design process for a Mars roving vehicle

NASA Technical Reports Server (NTRS)

Pavarini, C.; Baker, J.; Goldberg, A.

1971-01-01

The problem of determining the optimal design for a Mars roving vehicle is considered. A system model is generated by consideration of the physical constraints on the design parameters and the requirement that the system be deliverable to the Mars surface. An expression which evaluates system performance relative to mission goals as a function of the design parameters only is developed. The use of nonlinear programming techniques to optimize the design is proposed and an example considering only two of the vehicle subsystems is formulated and solved.

An algorithm for control system design via parameter optimization. M.S. Thesis

NASA Technical Reports Server (NTRS)

Sinha, P. K.

1972-01-01

An algorithm for design via parameter optimization has been developed for linear-time-invariant control systems based on the model reference adaptive control concept. A cost functional is defined to evaluate the system response relative to nominal, which involves in general the error between the system and nominal response, its derivatives and the control signals. A program for the practical implementation of this algorithm has been developed, with the computational scheme for the evaluation of the performance index based on Lyapunov's theorem for stability of linear invariant systems.

Systematic procedure for designing processes with multiple environmental objectives.

PubMed

Kim, Ki-Joo; Smith, Raymond L

2005-04-01

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 the complicated analysis of multidimensional results. In this paper, a novel systematic procedure is presented for designing processes with multiple environmental objectives. This procedure has four steps: initialization, screening, evaluation, and visualization. The first two steps are used for systematic problem formulation based on mass and energy estimation and order of magnitude analysis. In the third step, an efficient parallel multiobjective steady-state genetic algorithm is applied to design environmentally benign and economically viable processes and to provide more accurate and uniform Pareto optimal solutions. In the last step a new visualization technique for illustrating multiple objectives and their design parameters on the same diagram is developed. Through these integrated steps the decision-maker can easily determine design alternatives with respect to his or her preferences. Most importantly, this technique is independent of the number of objectives and design parameters. As a case study, acetic acid recovery from aqueous waste mixtures is investigated by minimizing eight potential environmental impacts and maximizing total profit. After applying the systematic procedure, the most preferred design alternatives and their design parameters are easily identified.

Generative Representations for Evolving Families of Designs

NASA Technical Reports Server (NTRS)

Hornby, Gregory S.

2003-01-01

Since typical evolutionary design systems encode only a single artifact with each individual, each time the objective changes a new set of individuals must be evolved. When this objective varies in a way that can be parameterized, a more general method is to use a representation in which a single individual encodes an entire class of artifacts. In addition to saving time by preventing the need for multiple evolutionary runs, the evolution of parameter-controlled designs can create families of artifacts with the same style and a reuse of parts between members of the family. In this paper an evolutionary design system is described which uses a generative representation to encode families of designs. Because a generative representation is an algorithmic encoding of a design, its input parameters are a way to control aspects of the design it generates. By evaluating individuals multiple times with different input parameters the evolutionary design system creates individuals in which the input parameter controls specific aspects of a design. This system is demonstrated on two design substrates: neural-networks which solve the 3/5/7-parity problem and three-dimensional tables of varying heights.

40 CFR 35.927-5 - Project procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... State, for example, of such parameters as per capita design flow, ratio of flow to design flow, flow... and, if required, an evaluation survey, is an essential element of step 1 facilities planning. It is a..., an adequate sewer system evaluation survey and, if required, a rehabilitation program must be...

40 CFR 35.927-5 - Project procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... State, for example, of such parameters as per capita design flow, ratio of flow to design flow, flow... and, if required, an evaluation survey, is an essential element of step 1 facilities planning. It is a..., an adequate sewer system evaluation survey and, if required, a rehabilitation program must be...

40 CFR 35.927-5 - Project procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... State, for example, of such parameters as per capita design flow, ratio of flow to design flow, flow... and, if required, an evaluation survey, is an essential element of step 1 facilities planning. It is a..., an adequate sewer system evaluation survey and, if required, a rehabilitation program must be...

40 CFR 35.927-5 - Project procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... State, for example, of such parameters as per capita design flow, ratio of flow to design flow, flow... and, if required, an evaluation survey, is an essential element of step 1 facilities planning. It is a..., an adequate sewer system evaluation survey and, if required, a rehabilitation program must be...

40 CFR 35.927-5 - Project procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... State, for example, of such parameters as per capita design flow, ratio of flow to design flow, flow... and, if required, an evaluation survey, is an essential element of step 1 facilities planning. It is a..., an adequate sewer system evaluation survey and, if required, a rehabilitation program must be...

Performance prediction evaluation of ceramic materials in point-focusing solar receivers

NASA Technical Reports Server (NTRS)

Ewing, J.; Zwissler, J.

1979-01-01

A performance prediction was adapted to evaluate the use of ceramic materials in solar receivers for point focusing distributed applications. System requirements were determined including the receiver operating environment and system operating parameters for various engine types. Preliminary receiver designs were evolved from these system requirements. Specific receiver designs were then evaluated to determine material functional requirements.

The acoustical design of vehicles-a challenge for qualitative evaluation

NASA Astrophysics Data System (ADS)

Schulte-Fortkamp, Brigitte; Genuit, Klaus; Fiebig, Andre

2005-09-01

Whenever the acoustical design of vehicles is explored, the crucial question about the appropriate method of evaluation arises. Research shows that not only acoustic but also non-acoustic parameters have a major influence on the way sounds are evaluated. Therefore, new methods of evaluation have to be implemented. Methods are needed which give the opportunity to test the quality of the given ambience and to register the effects and evaluations in their functional interdependence as well as the influence of personal and contextual factors. Moreover, new methods have to give insight into processes of evaluation and their contextual parameters. In other words, the task of evaluating acoustical ambiences consists of designating a set of social, psychological, and cultural conditions which are important to determine particular individual and collective behavior, attitudes, and also emotions relative to the given ambience. However, no specific recommendations exist yet which comprise particular descriptions of how to assess those specific sound effects. That is why there is a need to develop alternative methods of evaluation with whose help effects of acoustical ambiences can be better predicted. A method of evaluation will be presented which incorporates a new sensitive approach for the evaluation of vehicle sounds.

Accounting for human neurocognitive function in the design and evaluation of 360 degree situational awareness display systems

NASA Astrophysics Data System (ADS)

Metcalfe, Jason S.; Mikulski, Thomas; Dittman, Scott

2011-06-01

The current state and trajectory of development for display technologies supporting information acquisition, analysis and dissemination lends a broad informational infrastructure to operators of complex systems. The amount of information available threatens to outstrip the perceptual-cognitive capacities of operators, thus limiting their ability to effectively interact with targeted technologies. Therefore, a critical step in designing complex display systems is to find an appropriate match between capabilities, operational needs, and human ability to utilize complex information. The present work examines a set of evaluation parameters that were developed to facilitate the design of systems to support a specific military need; that is, the capacity to support the achievement and maintenance of real-time 360° situational awareness (SA) across a range of complex military environments. The focal point of this evaluation is on the reciprocity native to advanced engineering and human factors practices, with a specific emphasis on aligning the operator-systemenvironment fit. That is, the objective is to assess parameters for evaluation of 360° SA display systems that are suitable for military operations in tactical platforms across a broad range of current and potential operational environments. The approach is centered on five "families" of parameters, including vehicle sensors, data transmission, in-vehicle displays, intelligent automation, and neuroergonomic considerations. Parameters are examined under the assumption that displays designed to conform to natural neurocognitive processing will enhance and stabilize Soldier-system performance and, ultimately, unleash the human's potential to actively achieve and maintain the awareness necessary to enhance lethality and survivability within modern and future operational contexts.

Factorial Design Approach in Proportioning Prestressed Self-Compacting Concrete.

PubMed

Long, Wu-Jian; Khayat, Kamal Henri; Lemieux, Guillaume; Xing, Feng; Wang, Wei-Lun

2015-03-13

In order to model the effect of mixture parameters and material properties on the hardened properties of, prestressed self-compacting concrete (SCC), and also to investigate the extensions of the statistical models, a factorial design was employed to identify the relative significance of these primary parameters and their interactions in terms of the mechanical and visco-elastic properties of SCC. In addition to the 16 fractional factorial mixtures evaluated in the modeled region of -1 to +1, eight axial mixtures were prepared at extreme values of -2 and +2 with the other variables maintained at the central points. Four replicate central mixtures were also evaluated. The effects of five mixture parameters, including binder type, binder content, dosage of viscosity-modifying admixture (VMA), water-cementitious material ratio (w/cm), and sand-to-total aggregate ratio (S/A) on compressive strength, modulus of elasticity, as well as autogenous and drying shrinkage are discussed. The applications of the models to better understand trade-offs between mixture parameters and carry out comparisons among various responses are also highlighted. A logical design approach would be to use the existing model to predict the optimal design, and then run selected tests to quantify the influence of the new binder on the model.

[Application of Fourier amplitude sensitivity test in Chinese healthy volunteer population pharmacokinetic model of tacrolimus].

PubMed

Guan, Zheng; Zhang, Guan-min; Ma, Ping; Liu, Li-hong; Zhou, Tian-yan; Lu, Wei

2010-07-01

In this study, we evaluated the influence of different variance from each of the parameters on the output of tacrolimus population pharmacokinetic (PopPK) model in Chinese healthy volunteers, using Fourier amplitude sensitivity test (FAST). Besides, we estimated the index of sensitivity within whole course of blood sampling, designed different sampling times, and evaluated the quality of parameters' and the efficiency of prediction. It was observed that besides CL1/F, the index of sensitivity for all of the other four parameters (V1/F, V2/F, CL2/F and k(a)) in tacrolimus PopPK model showed relatively high level and changed fast with the time passing. With the increase of the variance of k(a), its indices of sensitivity increased obviously, associated with significant decrease in sensitivity index for the other parameters, and obvious change in peak time as well. According to the simulation of NONMEM and the comparison among different fitting results, we found that the sampling time points designed according to FAST surpassed the other time points. It suggests that FAST can access the sensitivities of model parameters effectively, and assist the design of clinical sampling times and the construction of PopPK model.

Probabilistic Modeling of Settlement Risk at Land Disposal Facilities - 12304

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

Foye, Kevin C.; Soong, Te-Yang

2012-07-01

The long-term reliability of land disposal facility final cover systems - and therefore the overall waste containment - depends on the distortions imposed on these systems by differential settlement/subsidence. The evaluation of differential settlement is challenging because of the heterogeneity of the waste mass (caused by inconsistent compaction, void space distribution, debris-soil mix ratio, waste material stiffness, time-dependent primary compression of the fine-grained soil matrix, long-term creep settlement of the soil matrix and the debris, etc.) at most land disposal facilities. Deterministic approaches to long-term final cover settlement prediction are not able to capture the spatial variability in the wastemore » mass and sub-grade properties which control differential settlement. An alternative, probabilistic solution is to use random fields to model the waste and sub-grade properties. The modeling effort informs the design, construction, operation, and maintenance of land disposal facilities. A probabilistic method to establish design criteria for waste placement and compaction is introduced using the model. Random fields are ideally suited to problems of differential settlement modeling of highly heterogeneous foundations, such as waste. Random fields model the seemingly random spatial distribution of a design parameter, such as compressibility. When used for design, the use of these models prompts the need for probabilistic design criteria. It also allows for a statistical approach to waste placement acceptance criteria. An example design evaluation was performed, illustrating the use of the probabilistic differential settlement simulation methodology to assemble a design guidance chart. The purpose of this design evaluation is to enable the designer to select optimal initial combinations of design slopes and quality control acceptance criteria that yield an acceptable proportion of post-settlement slopes meeting some design minimum. For this specific example, relative density, which can be determined through field measurements, was selected as the field quality control parameter for waste placement. This technique can be extended to include a rigorous performance-based methodology using other parameters (void space criteria, debris-soil mix ratio, pre-loading, etc.). As shown in this example, each parameter range, or sets of parameter ranges can be selected such that they can result in an acceptable, long-term differential settlement according to the probabilistic model. The methodology can also be used to re-evaluate the long-term differential settlement behavior at closed land disposal facilities to identify, if any, problematic facilities so that remedial action (e.g., reinforcement of upper and intermediate waste layers) can be implemented. Considering the inherent spatial variability in waste and earth materials and the need for engineers to apply sound quantitative practices to engineering analysis, it is important to apply the available probabilistic techniques to problems of differential settlement. One such method to implement probability-based differential settlement analyses for the design of landfill final covers has been presented. The design evaluation technique presented is one tool to bridge the gap from deterministic practice to probabilistic practice. (authors)« less

A Simulation Modeling Approach Method Focused on the Refrigerated Warehouses Using Design of Experiment

NASA Astrophysics Data System (ADS)

Cho, G. S.

2017-09-01

For performance optimization of Refrigerated Warehouses, design parameters are selected based on the physical parameters such as number of equipment and aisles, speeds of forklift for ease of modification. This paper provides a comprehensive framework approach for the system design of Refrigerated Warehouses. We propose a modeling approach which aims at the simulation optimization so as to meet required design specifications using the Design of Experiment (DOE) and analyze a simulation model using integrated aspect-oriented modeling approach (i-AOMA). As a result, this suggested method can evaluate the performance of a variety of Refrigerated Warehouses operations.

Gaussian beam profile shaping apparatus, method therefor and evaluation thereof

DOEpatents

Dickey, Fred M.; Holswade, Scott C.; Romero, Louis A.

1999-01-01

A method and apparatus maps a Gaussian beam into a beam with a uniform irradiance profile by exploiting the Fourier transform properties of lenses. A phase element imparts a design phase onto an input beam and the output optical field from a lens is then the Fourier transform of the input beam and the phase function from the phase element. The phase element is selected in accordance with a dimensionless parameter which is dependent upon the radius of the incoming beam, the desired spot shape, the focal length of the lens and the wavelength of the input beam. This dimensionless parameter can also be used to evaluate the quality of a system. In order to control the radius of the incoming beam, optics such as a telescope can be employed. The size of the target spot and the focal length can be altered by exchanging the transform lens, but the dimensionless parameter will remain the same. The quality of the system, and hence the value of the dimensionless parameter, can be altered by exchanging the phase element. The dimensionless parameter provides design guidance, system evaluation, and indication as to how to improve a given system.

Gaussian beam profile shaping apparatus, method therefore and evaluation thereof

DOEpatents

Dickey, F.M.; Holswade, S.C.; Romero, L.A.

1999-01-26

A method and apparatus maps a Gaussian beam into a beam with a uniform irradiance profile by exploiting the Fourier transform properties of lenses. A phase element imparts a design phase onto an input beam and the output optical field from a lens is then the Fourier transform of the input beam and the phase function from the phase element. The phase element is selected in accordance with a dimensionless parameter which is dependent upon the radius of the incoming beam, the desired spot shape, the focal length of the lens and the wavelength of the input beam. This dimensionless parameter can also be used to evaluate the quality of a system. In order to control the radius of the incoming beam, optics such as a telescope can be employed. The size of the target spot and the focal length can be altered by exchanging the transform lens, but the dimensionless parameter will remain the same. The quality of the system, and hence the value of the dimensionless parameter, can be altered by exchanging the phase element. The dimensionless parameter provides design guidance, system evaluation, and indication as to how to improve a given system. 27 figs.

Aeroelastic considerations for torsionally soft rotors

NASA Technical Reports Server (NTRS)

Mantay, W. R.; Yeager, W. T., Jr.

1986-01-01

A research study was initiated to systematically determine the impact of selected blade tip geometric parameters on conformable rotor performance and loads characteristics. The model articulated rotors included baseline and torsionally soft blades with interchangeable tips. Seven blade tip designs were evaluated on the baseline rotor and six tip designs were tested on the torsionally soft blades. The designs incorporated a systemmatic variation in geometric parameters including sweep, taper, and anhedral. The rotors were evaluated in the NASA Langley Transonic Dynamics Tunnel at several advance ratios, lift and propulsive force values, and tip Mach numbers. A track sensitivity study was also conducted at several advance ratios for both rotors. Based on the test results, tip parameter variations generated significant rotor performance and loads differences for both baseline and torsionally soft blades. Azimuthal variation of elastic twist generated by variations in the tip parameters strongly correlated with rotor performance and loads, but the magnitude of advancing blade elastic twist did not. In addition, fixed system vibratory loads and rotor track for potential conformable rotor candidates appears very sensitive to parametric rotor changes.

Efficient Bayesian experimental design for contaminant source identification

NASA Astrophysics Data System (ADS)

Zhang, J.; Zeng, L.

2013-12-01

In this study, an efficient full Bayesian approach is developed for the optimal sampling well location design and source parameter identification of groundwater contaminants. An information measure, i.e., the relative entropy, is employed to quantify the information gain from indirect concentration measurements in identifying unknown source parameters such as the release time, strength and location. In this approach, the sampling location that gives the maximum relative entropy is selected as the optimal one. Once the sampling location is determined, a Bayesian approach based on Markov Chain Monte Carlo (MCMC) is used to estimate unknown source parameters. In both the design and estimation, the contaminant transport equation is required to be solved many times to evaluate the likelihood. To reduce the computational burden, an interpolation method based on the adaptive sparse grid is utilized to construct a surrogate for the contaminant transport. The approximated likelihood can be evaluated directly from the surrogate, which greatly accelerates the design and estimation process. The accuracy and efficiency of our approach are demonstrated through numerical case studies. Compared with the traditional optimal design, which is based on the Gaussian linear assumption, the method developed in this study can cope with arbitrary nonlinearity. It can be used to assist in groundwater monitor network design and identification of unknown contaminant sources. Contours of the expected information gain. The optimal observing location corresponds to the maximum value. Posterior marginal probability densities of unknown parameters, the thick solid black lines are for the designed location. For comparison, other 7 lines are for randomly chosen locations. The true values are denoted by vertical lines. It is obvious that the unknown parameters are estimated better with the desinged location.

Stochastic Simulation Tool for Aerospace Structural Analysis

NASA Technical Reports Server (NTRS)

Knight, Norman F.; Moore, David F.

2006-01-01

Stochastic simulation refers to incorporating the effects of design tolerances and uncertainties into the design analysis model and then determining their influence on the design. A high-level evaluation of one such stochastic simulation tool, the MSC.Robust Design tool by MSC.Software Corporation, has been conducted. This stochastic simulation tool provides structural analysts with a tool to interrogate their structural design based on their mathematical description of the design problem using finite element analysis methods. This tool leverages the analyst's prior investment in finite element model development of a particular design. The original finite element model is treated as the baseline structural analysis model for the stochastic simulations that are to be performed. A Monte Carlo approach is used by MSC.Robust Design to determine the effects of scatter in design input variables on response output parameters. The tool was not designed to provide a probabilistic assessment, but to assist engineers in understanding cause and effect. It is driven by a graphical-user interface and retains the engineer-in-the-loop strategy for design evaluation and improvement. The application problem for the evaluation is chosen to be a two-dimensional shell finite element model of a Space Shuttle wing leading-edge panel under re-entry aerodynamic loading. MSC.Robust Design adds value to the analysis effort by rapidly being able to identify design input variables whose variability causes the most influence in response output parameters.

New parameters in adaptive testing of ferromagnetic materials utilizing magnetic Barkhausen noise

NASA Astrophysics Data System (ADS)

Pal'a, Jozef; Ušák, Elemír

2016-03-01

A new method of magnetic Barkhausen noise (MBN) measurement and optimization of the measured data processing with respect to non-destructive evaluation of ferromagnetic materials was tested. Using this method we tried to found, if it is possible to enhance sensitivity and stability of measurement results by replacing the traditional MBN parameter (root mean square) with some new parameter. In the tested method, a complex set of the MBN from minor hysteresis loops is measured. Afterward, the MBN data are collected into suitably designed matrices and optimal parameters of MBN with respect to maximum sensitivity to the evaluated variable are searched. The method was verified on plastically deformed steel samples. It was shown that the proposed measuring method and measured data processing bring an improvement of the sensitivity to the evaluated variable when comparing with measuring traditional MBN parameter. Moreover, we found a parameter of MBN, which is highly resistant to the changes of applied field amplitude and at the same time it is noticeably more sensitive to the evaluated variable.

Elaborate SMART MCNP Modelling Using ANSYS and Its Applications

NASA Astrophysics Data System (ADS)

Song, Jaehoon; Surh, Han-bum; Kim, Seung-jin; Koo, Bonsueng

2017-09-01

An MCNP 3-dimensional model can be widely used to evaluate various design parameters such as a core design or shielding design. Conventionally, a simplified 3-dimensional MCNP model is applied to calculate these parameters because of the cumbersomeness of modelling by hand. ANSYS has a function for converting the CAD `stp' format into an MCNP input in the geometry part. Using ANSYS and a 3- dimensional CAD file, a very detailed and sophisticated MCNP 3-dimensional model can be generated. The MCNP model is applied to evaluate the assembly weighting factor at the ex-core detector of SMART, and the result is compared with a simplified MCNP SMART model and assembly weighting factor calculated by DORT, which is a deterministic Sn code.

Implementation of the new AASHTO pavement design procedure in Louisiana : final report.

DOT National Transportation Integrated Search

1990-06-01

This study was undertaken to provide the LA DOTD with an implementation package to facilitate adoption of the new AASHTO Guide for Design of Pavement Structures. The study included evaluation of design parameters for rigid and flexible pavements, inc...

PFIM 4.0, an extended R program for design evaluation and optimization in nonlinear mixed-effect models.

PubMed

Dumont, Cyrielle; Lestini, Giulia; Le Nagard, Hervé; Mentré, France; Comets, Emmanuelle; Nguyen, Thu Thuy; Group, For The Pfim

2018-03-01

Nonlinear mixed-effect models (NLMEMs) are increasingly used for the analysis of longitudinal studies during drug development. When designing these studies, the expected Fisher information matrix (FIM) can be used instead of performing time-consuming clinical trial simulations. The function PFIM is the first tool for design evaluation and optimization that has been developed in R. In this article, we present an extended version, PFIM 4.0, which includes several new features. Compared with version 3.0, PFIM 4.0 includes a more complete pharmacokinetic/pharmacodynamic library of models and accommodates models including additional random effects for inter-occasion variability as well as discrete covariates. A new input method has been added to specify user-defined models through an R function. Optimization can be performed assuming some fixed parameters or some fixed sampling times. New outputs have been added regarding the FIM such as eigenvalues, conditional numbers, and the option of saving the matrix obtained after evaluation or optimization. Previously obtained results, which are summarized in a FIM, can be taken into account in evaluation or optimization of one-group protocols. This feature enables the use of PFIM for adaptive designs. The Bayesian individual FIM has been implemented, taking into account a priori distribution of random effects. Designs for maximum a posteriori Bayesian estimation of individual parameters can now be evaluated or optimized and the predicted shrinkage is also reported. It is also possible to visualize the graphs of the model and the sensitivity functions without performing evaluation or optimization. The usefulness of these approaches and the simplicity of use of PFIM 4.0 are illustrated by two examples: (i) an example of designing a population pharmacokinetic study accounting for previous results, which highlights the advantage of adaptive designs; (ii) an example of Bayesian individual design optimization for a pharmacodynamic study, showing that the Bayesian individual FIM can be a useful tool in therapeutic drug monitoring, allowing efficient prediction of estimation precision and shrinkage for individual parameters. PFIM 4.0 is a useful tool for design evaluation and optimization of longitudinal studies in pharmacometrics and is freely available at http://www.pfim.biostat.fr. Copyright © 2018 Elsevier B.V. All rights reserved.

A procedure for scaling sensory attributes based on multidimensional measurements: application to sensory sharpness of kitchen knives

NASA Astrophysics Data System (ADS)

Takatsuji, Toshiyuki; Tanaka, Ken-ichi

1996-06-01

A procedure is derived by which sensory attributes can be scaled as a function of various physical and/or chemical properties of the object to be tested. This procedure consists of four successive steps: (i) design and experiment, (ii) fabrication of specimens according to the design parameters, (iii) assessment of a sensory attribute using sensory evaluation and (iv) derivation of the relationship between the parameters and the sensory attribute. In these steps an experimental design using orthogonal arrays, analysis of variance and regression analyses are used strategically. When a specimen with the design parameters cannot be physically fabricated, an alternative specimen having parameters closest to the design is selected from a group of specimens which can be physically made. The influence of the deviation of actual parameters from the desired ones is also discussed. A method of confirming the validity of the regression equation is also investigated. The procedure is applied to scale the sensory sharpness of kitchen knives as a function of the edge angle and the roughness of the cutting edge.

Factorial Design Approach in Proportioning Prestressed Self-Compacting Concrete

PubMed Central

Long, Wu-Jian; Khayat, Kamal Henri; Lemieux, Guillaume; Xing, Feng; Wang, Wei-Lun

2015-01-01

In order to model the effect of mixture parameters and material properties on the hardened properties of, prestressed self-compacting concrete (SCC), and also to investigate the extensions of the statistical models, a factorial design was employed to identify the relative significance of these primary parameters and their interactions in terms of the mechanical and visco-elastic properties of SCC. In addition to the 16 fractional factorial mixtures evaluated in the modeled region of −1 to +1, eight axial mixtures were prepared at extreme values of −2 and +2 with the other variables maintained at the central points. Four replicate central mixtures were also evaluated. The effects of five mixture parameters, including binder type, binder content, dosage of viscosity-modifying admixture (VMA), water-cementitious material ratio (w/cm), and sand-to-total aggregate ratio (S/A) on compressive strength, modulus of elasticity, as well as autogenous and drying shrinkage are discussed. The applications of the models to better understand trade-offs between mixture parameters and carry out comparisons among various responses are also highlighted. A logical design approach would be to use the existing model to predict the optimal design, and then run selected tests to quantify the influence of the new binder on the model. PMID:28787990

Study on Ultra-deep Azimuthal Electromagnetic Resistivity LWD Tool by Influence Quantification on Azimuthal Depth of Investigation and Real Signal

NASA Astrophysics Data System (ADS)

Li, Kesai; Gao, Jie; Ju, Xiaodong; Zhu, Jun; Xiong, Yanchun; Liu, Shuai

2018-05-01

This paper proposes a new tool design of ultra-deep azimuthal electromagnetic (EM) resistivity logging while drilling (LWD) for deeper geosteering and formation evaluation, which can benefit hydrocarbon exploration and development. First, a forward numerical simulation of azimuthal EM resistivity LWD is created based on the fast Hankel transform (FHT) method, and its accuracy is confirmed under classic formation conditions. Then, a reasonable range of tool parameters is designed by analyzing the logging response. However, modern technological limitations pose challenges to selecting appropriate tool parameters for ultra-deep azimuthal detection under detectable signal conditions. Therefore, this paper uses grey relational analysis (GRA) to quantify the influence of tool parameters on voltage and azimuthal investigation depth. After analyzing thousands of simulation data under different environmental conditions, the random forest is used to fit data and identify an optimal combination of tool parameters due to its high efficiency and accuracy. Finally, the structure of the ultra-deep azimuthal EM resistivity LWD tool is designed with a theoretical azimuthal investigation depth of 27.42-29.89 m in classic different isotropic and anisotropic formations. This design serves as a reliable theoretical foundation for efficient geosteering and formation evaluation in high-angle and horizontal (HA/HZ) wells in the future.

Simultaneous versus sequential optimal experiment design for the identification of multi-parameter microbial growth kinetics as a function of temperature.

PubMed

Van Derlinden, E; Bernaerts, K; Van Impe, J F

2010-05-21

Optimal experiment design for parameter estimation (OED/PE) has become a popular tool for efficient and accurate estimation of kinetic model parameters. When the kinetic model under study encloses multiple parameters, different optimization strategies can be constructed. The most straightforward approach is to estimate all parameters simultaneously from one optimal experiment (single OED/PE strategy). However, due to the complexity of the optimization problem or the stringent limitations on the system's dynamics, the experimental information can be limited and parameter estimation convergence problems can arise. As an alternative, we propose to reduce the optimization problem to a series of two-parameter estimation problems, i.e., an optimal experiment is designed for a combination of two parameters while presuming the other parameters known. Two different approaches can be followed: (i) all two-parameter optimal experiments are designed based on identical initial parameter estimates and parameters are estimated simultaneously from all resulting experimental data (global OED/PE strategy), and (ii) optimal experiments are calculated and implemented sequentially whereby the parameter values are updated intermediately (sequential OED/PE strategy). This work exploits OED/PE for the identification of the Cardinal Temperature Model with Inflection (CTMI) (Rosso et al., 1993). This kinetic model describes the effect of temperature on the microbial growth rate and encloses four parameters. The three OED/PE strategies are considered and the impact of the OED/PE design strategy on the accuracy of the CTMI parameter estimation is evaluated. Based on a simulation study, it is observed that the parameter values derived from the sequential approach deviate more from the true parameters than the single and global strategy estimates. The single and global OED/PE strategies are further compared based on experimental data obtained from design implementation in a bioreactor. Comparable estimates are obtained, but global OED/PE estimates are, in general, more accurate and reliable. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Conditional statistical inference with multistage testing designs.

PubMed

Zwitser, Robert J; Maris, Gunter

2015-03-01

In this paper it is demonstrated how statistical inference from multistage test designs can be made based on the conditional likelihood. Special attention is given to parameter estimation, as well as the evaluation of model fit. Two reasons are provided why the fit of simple measurement models is expected to be better in adaptive designs, compared to linear designs: more parameters are available for the same number of observations; and undesirable response behavior, like slipping and guessing, might be avoided owing to a better match between item difficulty and examinee proficiency. The results are illustrated with simulated data, as well as with real data.

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

PubMed

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

2012-01-01

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

Evaluating the process parameters of the dry coating process using a 2(5-1) factorial design.

PubMed

Kablitz, Caroline Désirée; Urbanetz, Nora Anne

2013-02-01

A recent development of coating technology is dry coating, where polymer powder and liquid plasticizer are layered on the cores without using organic solvents or water. Several studies evaluating the process were introduced in literature, however, little information about the critical process parameters (CPPs) is given. Aim of the study was the investigation and optimization of CPPs with respect to one of the critical quality attributes (CQAs), the coating efficiency of the dry coating process in a rotary fluid bed. Theophylline pellets were coated with hydroxypropyl methylcellulose acetate succinate as enteric film former and triethyl citrate and acetylated monoglyceride as plasticizer. A 2(5-1) design of experiments (DOEs) was created investigating five independent process parameters namely coating temperature, curing temperature, feeding/spraying rate, air flow and rotor speed. The results were evaluated by multilinear regression using the software Modde(®) 7. It is shown, that generally, low feeding/spraying rates and low rotor speeds increase coating efficiency. High coating temperatures enhance coating efficiency, whereas medium curing temperatures have been found to be optimum in terms of coating efficiency. This study provides a scientific base for the design of efficient dry coating processes with respect to coating efficiency.

Evaluation of scour potential of cohesive soils - phase 2.

DOT National Transportation Integrated Search

2015-01-01

Determination of erosion parameters in order to predict scour depth is imperative to designing safe, : economic, and efficient bridge foundations. Scour behavior of granular soils is generally understood, : and design criteria have been established b...

Optimizing Parameters of Axial Pressure-Compounded Ultra-Low Power Impulse Turbines at Preliminary Design

NASA Astrophysics Data System (ADS)

Kalabukhov, D. S.; Radko, V. M.; Grigoriev, V. A.

2018-01-01

Ultra-low power turbine drives are used as energy sources in auxiliary power systems, energy units, terrestrial, marine, air and space transport within the confines of shaft power N td = 0.01…10 kW. In this paper we propose a new approach to the development of surrogate models for evaluating the integrated efficiency of multistage ultra-low power impulse turbine with pressure stages. This method is based on the use of existing mathematical models of ultra-low power turbine stage efficiency and mass. It has been used in a method for selecting the rational parameters of two-stage axial ultra-low power turbine. The article describes the basic features of an algorithm for two-stage turbine parameters optimization and for efficiency criteria evaluating. Pledged mathematical models are intended for use at the preliminary design of turbine drive. The optimization method was tested at preliminary design of an air starter turbine. Validation was carried out by comparing the results of optimization calculations and numerical gas-dynamic simulation in the Ansys CFX package. The results indicate a sufficient accuracy of used surrogate models for axial two-stage turbine parameters selection

Downstream processing from hot-melt extrusion towards tablets: A quality by design approach.

PubMed

Grymonpré, W; Bostijn, N; Herck, S Van; Verstraete, G; Vanhoorne, V; Nuhn, L; Rombouts, P; Beer, T De; Remon, J P; Vervaet, C

2017-10-05

Since the concept of continuous processing is gaining momentum in pharmaceutical manufacturing, a thorough understanding on how process and formulation parameters can impact the critical quality attributes (CQA) of the end product is more than ever required. This study was designed to screen the influence of process parameters and drug load during HME on both extrudate properties and tableting behaviour of an amorphous solid dispersion formulation using a quality-by-design (QbD) approach. A full factorial experimental design with 19 experiments was used to evaluate the effect of several process variables (barrel temperature: 160-200°C, screw speed: 50-200rpm, throughput: 0.2-0.5kg/h) and drug load (0-20%) as formulation parameter on the hot-melt extrusion (HME) process, extrudate and tablet quality of Soluplus ® -Celecoxib amorphous solid dispersions. A prominent impact of the formulation parameter on the CQA of the extrudates (i.e. solid state properties, moisture content, particle size distribution) and tablets (i.e. tabletability, compactibility, fragmentary behaviour, elastic recovery) was discovered. The resistance of the polymer matrix to thermo-mechanical stress during HME was confirmed throughout the experimental design space. In addition, the suitability of Raman spectroscopy as verification method for the active pharmaceutical ingredient (API) concentration in solid dispersions was evaluated. Incorporation of the Raman spectroscopy data in a PLS model enabled API quantification in the extrudate powders with none of the DOE-experiments resulting in extrudates with a CEL content deviating>3% of the label claim. This research paper emphasized that HME is a robust process throughout the experimental design space for obtaining amorphous glassy solutions and for tabletting of such formulations since only minimal impact of the process parameters was detected on the extrudate and tablet properties. However, the quality of extrudates and tablets can be optimized by adjusting specific formulations parameters (e.g. drug load). Copyright © 2017 Elsevier B.V. All rights reserved.

OPTIMAL EXPERIMENT DESIGN FOR MAGNETIC RESONANCE FINGERPRINTING

PubMed Central

Zhao, Bo; Haldar, Justin P.; Setsompop, Kawin; Wald, Lawrence L.

2017-01-01

Magnetic resonance (MR) fingerprinting is an emerging quantitative MR imaging technique that simultaneously acquires multiple tissue parameters in an efficient experiment. In this work, we present an estimation-theoretic framework to evaluate and design MR fingerprinting experiments. More specifically, we derive the Cramér-Rao bound (CRB), a lower bound on the covariance of any unbiased estimator, to characterize parameter estimation for MR fingerprinting. We then formulate an optimal experiment design problem based on the CRB to choose a set of acquisition parameters (e.g., flip angles and/or repetition times) that maximizes the signal-to-noise ratio efficiency of the resulting experiment. The utility of the proposed approach is validated by numerical studies. Representative results demonstrate that the optimized experiments allow for substantial reduction in the length of an MR fingerprinting acquisition, and substantial improvement in parameter estimation performance. PMID:28268369

Optimal experiment design for magnetic resonance fingerprinting.

PubMed

Bo Zhao; Haldar, Justin P; Setsompop, Kawin; Wald, Lawrence L

2016-08-01

Magnetic resonance (MR) fingerprinting is an emerging quantitative MR imaging technique that simultaneously acquires multiple tissue parameters in an efficient experiment. In this work, we present an estimation-theoretic framework to evaluate and design MR fingerprinting experiments. More specifically, we derive the Cramér-Rao bound (CRB), a lower bound on the covariance of any unbiased estimator, to characterize parameter estimation for MR fingerprinting. We then formulate an optimal experiment design problem based on the CRB to choose a set of acquisition parameters (e.g., flip angles and/or repetition times) that maximizes the signal-to-noise ratio efficiency of the resulting experiment. The utility of the proposed approach is validated by numerical studies. Representative results demonstrate that the optimized experiments allow for substantial reduction in the length of an MR fingerprinting acquisition, and substantial improvement in parameter estimation performance.

The effect of Fisher information matrix approximation methods in population optimal design calculations.

PubMed

Strömberg, Eric A; Nyberg, Joakim; Hooker, Andrew C

2016-12-01

With the increasing popularity of optimal design in drug development it is important to understand how the approximations and implementations of the Fisher information matrix (FIM) affect the resulting optimal designs. The aim of this work was to investigate the impact on design performance when using two common approximations to the population model and the full or block-diagonal FIM implementations for optimization of sampling points. Sampling schedules for two example experiments based on population models were optimized using the FO and FOCE approximations and the full and block-diagonal FIM implementations. The number of support points was compared between the designs for each example experiment. The performance of these designs based on simulation/estimations was investigated by computing bias of the parameters as well as through the use of an empirical D-criterion confidence interval. Simulations were performed when the design was computed with the true parameter values as well as with misspecified parameter values. The FOCE approximation and the Full FIM implementation yielded designs with more support points and less clustering of sample points than designs optimized with the FO approximation and the block-diagonal implementation. The D-criterion confidence intervals showed no performance differences between the full and block diagonal FIM optimal designs when assuming true parameter values. However, the FO approximated block-reduced FIM designs had higher bias than the other designs. When assuming parameter misspecification in the design evaluation, the FO Full FIM optimal design was superior to the FO block-diagonal FIM design in both of the examples.

CONSIDERATIONS FOR INNOVATIVE REMEDIATION TECHNOLOGY EVALUATION SAMPLING PLANS

EPA Science Inventory

Field trials of innovative subsurface cleanup technologies require the use of integrated site characterization approaches to obtain critical design parameters, to evaluate pre-treatment contaminant distributions, and to assess process efficiency. This review focuses on the trans...

A Multi-Week Behavioral Sampling Tag for Sound Effects Studies: Design Trade-Offs and Prototype Evaluation

DTIC Science & Technology

2013-09-30

performance of algorithms detecting dives, strokes , clicks, respiration and gait changes. (ii) Calibration errors: Size and power constraints in...acceptance parameters used to detect and classify events. For example, swim stroke detection requires parameters defining the minimum magnitude and the min...and max duration of a stroke . Species dependent parameters can be selected from existing DTAG data but other parameters depend on the size of the

Industrial laser welding evaluation study

NASA Technical Reports Server (NTRS)

Hella, R.; Locke, E.; Ream, S.

1974-01-01

High power laser welding was evaluated for fabricating space vehicle boosters. This evaluation was made for 1/4 in. and 1/2 in. aluminum (2219) and 1/4 in. and 1/2 in. D6AC steel. The Avco HPL 10 kW industrial laser was used to perform the evaluation. The objective has been achieved through the completion of the following technical tasks: (1) parameter study to optimize welding and material parameters; (2) preparation of welded panels for MSFC evaluation; and (3) demonstration of the repeatability of laser welding equipment. In addition, the design concept for a laser welding system capable of welding large space vehicle boosters has been developed.

A method of rapidly evaluating image quality of NED optical system

NASA Astrophysics Data System (ADS)

Sun, Qi; Qiu, Chuankai; Yang, Huan

2014-11-01

In recent years, with the development of technology of micro-display, advanced optics and the software and hardware, near-to-eye display ( NED) optical system will have a wide range of potential applications in the fields of amusement and virtual reality. However, research on the evaluating image quality of this kind optical system is comparatively lagging behind. Although now there are some methods and equipment for evaluation, they can't be applied in commercial production because of their complex operation and inaccuracy. In this paper, an academic method is proposed and a Rapid Evaluation System (RES) is designed to evaluate the image of optical system rapidly and exactly. Firstly, a set of parameters that eyes are sensitive to and also express the quality of system should be extracted and quantized to be criterion, so the evaluation standards can be established. Then, some parameters can be detected by RES consisted of micro-display, CCD camera and computer and so on. By process of scaling, the measuring results of the RES are exact and creditable, relationship between object measurement, subjective evaluation and the RES will be established. After that, image quality of optical system can be evaluated just by detecting parameters of that. The RES is simple and the results of evaluation are exact and keeping with human vision. So the method can be used not only for optimizing design of optical system, but also for evaluation in commercial production.

Laser application to measure vertical sea temperature and turbidity, design phase

NASA Technical Reports Server (NTRS)

Hirschberg, J. G.; Wouters, A. W.; Simon, K. M.; Byrne, J. D.; Deverdun, C. E.

1976-01-01

An experiment to test a new method was designed, using backscattered radiation from a laser beam to measure oceanographic parameters in a fraction of a second. Tyndall, Rayleigh, Brillouin, and Raman scattering all are utilized to evaluate the parameters. A beam from a continuous argon ion laser is used together with an interferometer and interference filters to gather the information. The results are checked by direct measurements. Future shipboard and airborne experiments are described.

Developing a quality by design approach to model tablet dissolution testing: an industrial case study.

PubMed

Yekpe, Ketsia; Abatzoglou, Nicolas; Bataille, Bernard; Gosselin, Ryan; Sharkawi, Tahmer; Simard, Jean-Sébastien; Cournoyer, Antoine

2018-07-01

This study applied the concept of Quality by Design (QbD) to tablet dissolution. Its goal was to propose a quality control strategy to model dissolution testing of solid oral dose products according to International Conference on Harmonization guidelines. The methodology involved the following three steps: (1) a risk analysis to identify the material- and process-related parameters impacting the critical quality attributes of dissolution testing, (2) an experimental design to evaluate the influence of design factors (attributes and parameters selected by risk analysis) on dissolution testing, and (3) an investigation of the relationship between design factors and dissolution profiles. Results show that (a) in the case studied, the two parameters impacting dissolution kinetics are active pharmaceutical ingredient particle size distributions and tablet hardness and (b) these two parameters could be monitored with PAT tools to predict dissolution profiles. Moreover, based on the results obtained, modeling dissolution is possible. The practicality and effectiveness of the QbD approach were demonstrated through this industrial case study. Implementing such an approach systematically in industrial pharmaceutical production would reduce the need for tablet dissolution testing.

Application of Quality by Design to the characterization of the cell culture process of an Fc-Fusion protein.

PubMed

Rouiller, Yolande; Solacroup, Thomas; Deparis, Véronique; Barbafieri, Marco; Gleixner, Ralf; Broly, Hervé; Eon-Duval, Alex

2012-06-01

The production bioreactor step of an Fc-Fusion protein manufacturing cell culture process was characterized following Quality by Design principles. Using scientific knowledge derived from the literature and process knowledge gathered during development studies and manufacturing to support clinical trials, potential critical and key process parameters with a possible impact on product quality and process performance, respectively, were determined during a risk assessment exercise. The identified process parameters were evaluated using a design of experiment approach. The regression models generated from the data allowed characterizing the impact of the identified process parameters on quality attributes. The main parameters having an impact on product titer were pH and dissolved oxygen, while those having the highest impact on process- and product-related impurities and variants were pH and culture duration. The models derived from characterization studies were used to define the cell culture process design space. The design space limits were set in such a way as to ensure that the drug substance material would consistently have the desired quality. Copyright © 2012 Elsevier B.V. All rights reserved.

Space qualified Nd:YAG laser (phase 1 - design)

NASA Technical Reports Server (NTRS)

Foster, J. D.; Kirk, R. F.

1971-01-01

Results of a design study and preliminary design of a space qualified Nd:YAG laser are presented. A theoretical model of the laser was developed to allow the evaluation of the effects of various parameters on its performance. Various pump lamps were evaluated and sum pumping was considered. Cooling requirements were examined and cooling methods such as radiation, cryogenic and conductive were analysed. Power outputs and efficiences of various configurations and the pump and laser lifetime are discussed. Also considered were modulation and modulating methods.

Evaluation of laminar flow control system concepts for subsonic commercial transport aircraft

NASA Technical Reports Server (NTRS)

1980-01-01

A study was conducted to evaluate alternatives in the design of laminar flow control (LFC) subsonic commercial transport aircraft for operation in the 1980's period. Analyses were conducted to select mission parameters and define optimum aircraft configurational parameters for the selected mission, defined by a passenger payload of 400 and a design range of 12,038 km (6500 n mi). The baseline aircraft developed for this mission was used as a vehicle for the evaluation and development of alternative LFC system concepts. Alternatives were evaluated in the areas of aerodynamics structures, materials, LFC systems, leading-edge region cleaning and integration of auxiliary systems. Based on these evaluations, concept in each area were selected for further development and testing and ultimate incorporation in the final study aircraft. Relative to a similarly-optimized advanced technology turbulent transport, the final LFC configuration is approximately equal in direct operating cost but provides decreases of 8.2% in gross weight and 21.7% in fuel consumption.

Application of a central composite design to evaluate the influence of colouring agents in lipstick formulation.

PubMed

Zibetti, F M; Cardoso, A C A; Desmarais, G C; de Almeida, K B; do Nascimento, L M; Rolim, L F; Rocha, M S; Duarte, N G D; Azevedo, P H R A; Araújo, J L; Mourão, S C; Falcão, D Q

2016-10-01

The aim of this study was to evaluate by central composite design the influence of colouring agents in lipstick colour, expressed by L*, a*, b* parameters (CIELab system) where L* indicates lightness, and a* and b* are the chromaticity coordinates. The a* indicates colour direction from red to green and b* from yellow to blue. Lipsticks were formulated as described by (Recent Adv. Prosp. Potent Med. Plants, 2009 and 39). The combined effect of three variables (dye, pigment and opacifier) was evaluated by different formulations in a central composite design. Colour parameters (L*, a*, b*) were analysed by reflectance spectrophotometry. Lipsticks were characterized by visual analyses and melting point. All formulations were integrate and homogeneous. The pigments and dye do not influence in colour transfer neither in melting point of lipsticks. On the other hand, results indicated that variables studied show influence only in parameter b*, whereas for L* and a* values there was no significant difference (P < 0.05). It was possible to verify that only the colour parameter b* was influenced by the variation in colouring agent's concentrations in lipstick formulation, leading to the production of the colour ranging between violet and light red. Such results are useful for developing new lipstick formulations to obtain the desired colour in the final product. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Simultaneous state-parameter estimation supports the evaluation of data assimilation performance and measurement design for soil-water-atmosphere-plant system

NASA Astrophysics Data System (ADS)

Hu, Shun; Shi, Liangsheng; Zha, Yuanyuan; Williams, Mathew; Lin, Lin

2017-12-01

Improvements to agricultural water and crop managements require detailed information on crop and soil states, and their evolution. Data assimilation provides an attractive way of obtaining these information by integrating measurements with model in a sequential manner. However, data assimilation for soil-water-atmosphere-plant (SWAP) system is still lack of comprehensive exploration due to a large number of variables and parameters in the system. In this study, simultaneous state-parameter estimation using ensemble Kalman filter (EnKF) was employed to evaluate the data assimilation performance and provide advice on measurement design for SWAP system. The results demonstrated that a proper selection of state vector is critical to effective data assimilation. Especially, updating the development stage was able to avoid the negative effect of ;phenological shift;, which was caused by the contrasted phenological stage in different ensemble members. Simultaneous state-parameter estimation (SSPE) assimilation strategy outperformed updating-state-only (USO) assimilation strategy because of its ability to alleviate the inconsistency between model variables and parameters. However, the performance of SSPE assimilation strategy could deteriorate with an increasing number of uncertain parameters as a result of soil stratification and limited knowledge on crop parameters. In addition to the most easily available surface soil moisture (SSM) and leaf area index (LAI) measurements, deep soil moisture, grain yield or other auxiliary data were required to provide sufficient constraints on parameter estimation and to assure the data assimilation performance. This study provides an insight into the response of soil moisture and grain yield to data assimilation in SWAP system and is helpful for soil moisture movement and crop growth modeling and measurement design in practice.

Effect of Electron Beam Freeform Fabrication (EBF3) Processing Parameters on Composition of Ti-6-4

NASA Technical Reports Server (NTRS)

Lach, Cynthia L.; Taminger, Karen; Schuszler, A. Bud, II; Sankaran, Sankara; Ehlers, Helen; Nasserrafi, Rahbar; Woods, Bryan

2007-01-01

The Electron Beam Freeform Fabrication (EBF3) process developed at NASA Langley Research Center was evaluated using a design of experiments approach to determine the effect of processing parameters on the composition and geometry of Ti-6-4 deposits. The effects of three processing parameters: beam power, translation speed, and wire feed rate, were investigated by varying one while keeping the remaining parameters constant. A three-factorial, three-level, fully balanced mutually orthogonal array (L27) design of experiments approach was used to examine the effects of low, medium, and high settings for the processing parameters on the chemistry, geometry, and quality of the resulting deposits. Single bead high deposits were fabricated and evaluated for 27 experimental conditions. Loss of aluminum in Ti-6-4 was observed in EBF3 processing due to selective vaporization of the aluminum from the sustained molten pool in the vacuum environment; therefore, the chemistries of the deposits were measured and compared with the composition of the initial wire and base plate to determine if the loss of aluminum could be minimized through careful selection of processing parameters. The influence of processing parameters and coupling between these parameters on bulk composition, measured by Direct Current Plasma (DCP), local microchemistries determined by Wavelength Dispersive Spectrometry (WDS), and deposit geometry will also be discussed.

Automatic design of optical systems by digital computer

NASA Technical Reports Server (NTRS)

Casad, T. A.; Schmidt, L. F.

1967-01-01

Computer program uses geometrical optical techniques and a least squares optimization method employing computing equipment for the automatic design of optical systems. It evaluates changes in various optical parameters, provides comprehensive ray-tracing, and generally determines the acceptability of the optical system characteristics.

Advanced Method to Estimate Fuel Slosh Simulation Parameters

NASA Technical Reports Server (NTRS)

Schlee, Keith; Gangadharan, Sathya; Ristow, James; Sudermann, James; Walker, Charles; Hubert, Carl

2005-01-01

The nutation (wobble) of a spinning spacecraft in the presence of energy dissipation is a well-known problem in dynamics and is of particular concern for space missions. The nutation of a spacecraft spinning about its minor axis typically grows exponentially and the rate of growth is characterized by the Nutation Time Constant (NTC). For launch vehicles using spin-stabilized upper stages, fuel slosh in the spacecraft propellant tanks is usually the primary source of energy dissipation. For analytical prediction of the NTC this fuel slosh is commonly modeled using simple mechanical analogies such as pendulums or rigid rotors coupled to the spacecraft. Identifying model parameter values which adequately represent the sloshing dynamics is the most important step in obtaining an accurate NTC estimate. Analytic determination of the slosh model parameters has met with mixed success and is made even more difficult by the introduction of propellant management devices and elastomeric diaphragms. By subjecting full-sized fuel tanks with actual flight fuel loads to motion similar to that experienced in flight and measuring the forces experienced by the tanks these parameters can be determined experimentally. Currently, the identification of the model parameters is a laborious trial-and-error process in which the equations of motion for the mechanical analog are hand-derived, evaluated, and their results are compared with the experimental results. The proposed research is an effort to automate the process of identifying the parameters of the slosh model using a MATLAB/SimMechanics-based computer simulation of the experimental setup. Different parameter estimation and optimization approaches are evaluated and compared in order to arrive at a reliable and effective parameter identification process. To evaluate each parameter identification approach, a simple one-degree-of-freedom pendulum experiment is constructed and motion is induced using an electric motor. By applying the estimation approach to a simple, accurately modeled system, its effectiveness and accuracy can be evaluated. The same experimental setup can then be used with fluid-filled tanks to further evaluate the effectiveness of the process. Ultimately, the proven process can be applied to the full-sized spinning experimental setup to quickly and accurately determine the slosh model parameters for a particular spacecraft mission. Automating the parameter identification process will save time, allow more changes to be made to proposed designs, and lower the cost in the initial design stages.

CAPS Simulation Environment Development

NASA Technical Reports Server (NTRS)

Murphy, Douglas G.; Hoffman, James A.

2005-01-01

The final design for an effective Comet/Asteroid Protection System (CAPS) will likely come after a number of competing designs have been simulated and evaluated. Because of the large number of design parameters involved in a system capable of detecting an object, accurately determining its orbit, and diverting the impact threat, a comprehensive simulation environment will be an extremely valuable tool for the CAPS designers. A successful simulation/design tool will aid the user in identifying the critical parameters in the system and eventually allow for automatic optimization of the design once the relationships of the key parameters are understood. A CAPS configuration will consist of space-based detectors whose purpose is to scan the celestial sphere in search of objects likely to make a close approach to Earth and to determine with the greatest possible accuracy the orbits of those objects. Other components of a CAPS configuration may include systems for modifying the orbits of approaching objects, either for the purpose of preventing a collision or for positioning the object into an orbit where it can be studied or used as a mineral resource. The Synergistic Engineering Environment (SEE) is a space-systems design, evaluation, and visualization software tool being leveraged to simulate these aspects of the CAPS study. The long-term goal of the SEE is to provide capabilities to allow the user to build and compare various CAPS designs by running end-to-end simulations that encompass the scanning phase, the orbit determination phase, and the orbit modification phase of a given scenario. Herein, a brief description of the expected simulation phases is provided, the current status and available features of the SEE software system is reported, and examples are shown of how the system is used to build and evaluate a CAPS detection design. Conclusions and the roadmap for future development of the SEE are also presented.

Design of an Inertial-Sensor-Based Data Glove for Hand Function Evaluation.

PubMed

Lin, Bor-Shing; Lee, I-Jung; Yang, Shu-Yu; Lo, Yi-Chiang; Lee, Junghsi; Chen, Jean-Lon

2018-05-13

Capturing hand motions for hand function evaluations is essential in the medical field. Various data gloves have been developed for rehabilitation and manual dexterity assessments. This study proposed a modular data glove with 9-axis inertial measurement units (IMUs) to obtain static and dynamic parameters during hand function evaluation. A sensor fusion algorithm is used to calculate the range of motion of joints. The data glove is designed to have low cost, easy wearability, and high reliability. Owing to the modular design, the IMU board is independent and extensible and can be used with various microcontrollers to realize more medical applications. This design greatly enhances the stability and maintainability of the glove.

Experimental Design for Stochastic Models of Nonlinear Signaling Pathways Using an Interval-Wise Linear Noise Approximation and State Estimation.

PubMed

Zimmer, Christoph

2016-01-01

Computational modeling is a key technique for analyzing models in systems biology. There are well established methods for the estimation of the kinetic parameters in models of ordinary differential equations (ODE). Experimental design techniques aim at devising experiments that maximize the information encoded in the data. For ODE models there are well established approaches for experimental design and even software tools. However, data from single cell experiments on signaling pathways in systems biology often shows intrinsic stochastic effects prompting the development of specialized methods. While simulation methods have been developed for decades and parameter estimation has been targeted for the last years, only very few articles focus on experimental design for stochastic models. The Fisher information matrix is the central measure for experimental design as it evaluates the information an experiment provides for parameter estimation. This article suggest an approach to calculate a Fisher information matrix for models containing intrinsic stochasticity and high nonlinearity. The approach makes use of a recently suggested multiple shooting for stochastic systems (MSS) objective function. The Fisher information matrix is calculated by evaluating pseudo data with the MSS technique. The performance of the approach is evaluated with simulation studies on an Immigration-Death, a Lotka-Volterra, and a Calcium oscillation model. The Calcium oscillation model is a particularly appropriate case study as it contains the challenges inherent to signaling pathways: high nonlinearity, intrinsic stochasticity, a qualitatively different behavior from an ODE solution, and partial observability. The computational speed of the MSS approach for the Fisher information matrix allows for an application in realistic size models.

Application of experimental design in geothermal resources assessment of Ciwidey-Patuha, West Java, Indonesia

NASA Astrophysics Data System (ADS)

Ashat, Ali; Pratama, Heru Berian

2017-12-01

The successful Ciwidey-Patuha geothermal field size assessment required integration data analysis of all aspects to determined optimum capacity to be installed. Resources assessment involve significant uncertainty of subsurface information and multiple development scenarios from these field. Therefore, this paper applied the application of experimental design approach to the geothermal numerical simulation of Ciwidey-Patuha to generate probabilistic resource assessment result. This process assesses the impact of evaluated parameters affecting resources and interacting between these parameters. This methodology have been successfully estimated the maximum resources with polynomial function covering the entire range of possible values of important reservoir parameters.

Design and operational parameters of a rooftop rainwater harvesting system: definition, sensitivity and verification.

PubMed

Mun, J S; Han, M Y

2012-01-01

The appropriate design and evaluation of a rainwater harvesting (RWH) system is necessary to improve system performance and the stability of the water supply. The main design parameters (DPs) of an RWH system are rainfall, catchment area, collection efficiency, tank volume and water demand. Its operational parameters (OPs) include rainwater use efficiency (RUE), water saving efficiency (WSE) and cycle number (CN). The sensitivity analysis of a rooftop RWH system's DPs to its OPs reveals that the ratio of tank volume to catchment area (V/A) for an RWH system in Seoul, South Korea is recommended between 0.03 and 0.08 in terms of rate of change in RUE. The appropriate design value of V/A is varied with D/A. The extra tank volume up to V/A of 0.15∼0.2 is also available, if necessary to secure more water. Accordingly, we should figure out suitable value or range of DPs based on the sensitivity analysis to optimize design of an RWH system or improve operation efficiency. The operational data employed in this study, which was carried out to validate the design and evaluation method of an RWH system, were obtained from the system in use at a dormitory complex at Seoul National University (SNU) in Korea. The results of these operational data are in good agreement with those used in the initial simulation. The proposed method and the results of this research will be useful in evaluating and comparing the performance of RWH systems. It is found that RUE can be increased by expanding the variety of rainwater uses, particularly in the high rainfall season. Copyright © 2011 Elsevier Ltd. All rights reserved.

Analysis and design of a capsule landing system and surface vehicle control system for Mars exporation

NASA Technical Reports Server (NTRS)

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1972-01-01

The problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars were investigated. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; navigation, terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks were studied: vehicle model design, mathematical modeling of dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement and transport parameter evaluation.

Computer aided design of digital controller for radial active magnetic bearings

NASA Technical Reports Server (NTRS)

Cai, Zhong; Shen, Zupei; Zhang, Zuming; Zhao, Hongbin

1992-01-01

A five degree of freedom Active Magnetic Bearing (AMB) system is developed which is controlled by digital controllers. The model of the radial AMB system is linearized and the state equation is derived. Based on the state variables feedback theory, digital controllers are designed. The performance of the controllers are evaluated according to experimental results. The Computer Aided Design (CAD) method is used to design controllers for magnetic bearings. The controllers are implemented with a digital signal processing (DSP) system. The control algorithms are realized with real-time programs. It is very easy to change the controller by changing or modifying the programs. In order to identify the dynamic parameters of the controlled magnetic system, a special experiment was carried out. Also, the online Recursive Least Squares (RLS) parameter identification method is studied. It can be realized with the digital controllers. Online parameter identification is essential for the realization of an adaptive controller.

Market-Based Coordination of Thermostatically Controlled Loads—Part I: A Mechanism Design Formulation

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

Li, Sen; Zhang, Wei; Lian, Jianming

This paper focuses on the coordination of a population of Thermostatically Controlled Loads (TCLs) with unknown parameters to achieve group objectives. The problem involves designing the bidding and market clearing strategy to motivate self-interested users to realize efficient energy allocation subject to a peak power constraint. Using the mechanism design approach, we propose a market-based coordination framework, which can effectively incorporate heterogeneous load dynamics, systematically deal with user preferences, account for the unknown load model parameters, and enable the real-world implementation with limited communication resources. This paper is divided into two parts. Part I presents a mathematical formulation of themore » problem and develops a coordination framework using the mechanism design approach. Part II presents a learning scheme to account for the unknown load model parameters, and evaluates the proposed framework through realistic simulations.« less

Performance Model and Sensitivity Analysis for a Solar Thermoelectric Generator

NASA Astrophysics Data System (ADS)

Rehman, Naveed Ur; Siddiqui, Mubashir Ali

2017-03-01

In this paper, a regression model for evaluating the performance of solar concentrated thermoelectric generators (SCTEGs) is established and the significance of contributing parameters is discussed in detail. The model is based on several natural, design and operational parameters of the system, including the thermoelectric generator (TEG) module and its intrinsic material properties, the connected electrical load, concentrator attributes, heat transfer coefficients, solar flux, and ambient temperature. The model is developed by fitting a response curve, using the least-squares method, to the results. The sample points for the model were obtained by simulating a thermodynamic model, also developed in this paper, over a range of values of input variables. These samples were generated employing the Latin hypercube sampling (LHS) technique using a realistic distribution of parameters. The coefficient of determination was found to be 99.2%. The proposed model is validated by comparing the predicted results with those in the published literature. In addition, based on the elasticity for parameters in the model, sensitivity analysis was performed and the effects of parameters on the performance of SCTEGs are discussed in detail. This research will contribute to the design and performance evaluation of any SCTEG system for a variety of applications.

New evaluation parameter for wearable thermoelectric generators

NASA Astrophysics Data System (ADS)

Wijethunge, Dimuthu; Kim, Woochul

2018-04-01

Wearable devices constitute a key application area for thermoelectric devices. However, owing to new constraints in wearable applications, a few conventional device optimization techniques are not appropriate and material evaluation parameters, such as figure of merit (zT) and power factor (PF), tend to be inadequate. We illustrated the incompleteness of zT and PF by performing simulations and considering different thermoelectric materials. The results indicate a weak correlation between device performance and zT and PF. In this study, we propose a new evaluation parameter, zTwearable, which is better suited for wearable applications compared to conventional zT. Owing to size restrictions, gap filler based device optimization is extremely critical in wearable devices. With respect to the occasions in which gap fillers are used, expressions for power, effective thermal conductivity (keff), and optimum load electrical ratio (mopt) are derived. According to the new parameters, the thermal conductivity of the material has become much more critical now. The proposed new evaluation parameter, namely, zTwearable, is extremely useful in the selection of an appropriate thermoelectric material among various candidates prior to the commencement of the actual design process.

Optimization of the Design of Pre-Signal System Using Improved Cellular Automaton

PubMed Central

Li, Yan; Li, Ke; Tao, Siran; Chen, Kuanmin

2014-01-01

The pre-signal system can improve the efficiency of intersection approach under rational design. One of the main obstacles in optimizing the design of pre-signal system is that driving behaviors in the sorting area cannot be well evaluated. The NaSch model was modified by considering slow probability, turning-deceleration rules, and lane changing rules. It was calibrated with field observed data to explore the interactions among design parameters. The simulation results of the proposed model indicate that the length of sorting area, traffic demand, signal timing, and lane allocation are the most important influence factors. The recommendations of these design parameters are demonstrated. The findings of this paper can be foundations for the design of pre-signal system and show promising improvement in traffic mobility. PMID:25435871

Design Protocols and Analytical Strategies that Incorporate Structural Reliability Models

NASA Technical Reports Server (NTRS)

Duffy, Stephen F.

1995-01-01

The general goal of this project is to establish design protocols that enable the engineer to analyze and predict certain types of behavior in ceramic composites. Sections of the final report addresses the following: Description of the Problem that Motivated the Technology Development, Description of the New Technology that was Developed, Unique and Novel Features of the Technology and Results/Benefits of Application (year by year accomplishments), and Utilization of New Technology in Non-Aerospace Applications. Activities for this reporting period included the development of a design analysis as part of a cooperative agreement with general Electric Aircraft Engines. The effort focused on modifying the Toughened Ceramics Analysis and Reliability Evaluation of Structures (TCARES) algorithm for use in the design of engine components fabricated from NiAl. Other activities related to the development of an ASTM standard practice for estimating Weibull parameters. The standard focuses on the evaluation and reporting of uniaxial strength data, and the estimation of probability distribution parameters for ceramics which fail in a brittle fashion.

40 CFR 86.1829-01 - Durability and emission testing requirements; waivers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... manufacturer's engineering evaluation of appropriate high-altitude emission testing, all light-duty vehicles..., development tests, or other appropriate information and good engineering judgment. (2) Evaporative/Refueling... manufacturer's engineering evaluation of appropriate testing and/or design parameters, all light-duty vehicles...

Multivariate Statistical Analysis of Cigarette Design Feature Influence on ISO TNCO Yields.

PubMed

Agnew-Heard, Kimberly A; Lancaster, Vicki A; Bravo, Roberto; Watson, Clifford; Walters, Matthew J; Holman, Matthew R

2016-06-20

The aim of this study is to explore how differences in cigarette physical design parameters influence tar, nicotine, and carbon monoxide (TNCO) yields in mainstream smoke (MSS) using the International Organization of Standardization (ISO) smoking regimen. Standardized smoking methods were used to evaluate 50 U.S. domestic brand cigarettes and a reference cigarette representing a range of TNCO yields in MSS collected from linear smoking machines using a nonintense smoking regimen. Multivariate statistical methods were used to form clusters of cigarettes based on their ISO TNCO yields and then to explore the relationship between the ISO generated TNCO yields and the nine cigarette physical design parameters between and within each cluster simultaneously. The ISO generated TNCO yields in MSS are 1.1-17.0 mg tar/cigarette, 0.1-2.2 mg nicotine/cigarette, and 1.6-17.3 mg CO/cigarette. Cluster analysis divided the 51 cigarettes into five discrete clusters based on their ISO TNCO yields. No one physical parameter dominated across all clusters. Predicting ISO machine generated TNCO yields based on these nine physical design parameters is complex due to the correlation among and between the nine physical design parameters and TNCO yields. From these analyses, it is estimated that approximately 20% of the variability in the ISO generated TNCO yields comes from other parameters (e.g., filter material, filter type, inclusion of expanded or reconstituted tobacco, and tobacco blend composition, along with differences in tobacco leaf origin and stalk positions and added ingredients). A future article will examine the influence of these physical design parameters on TNCO yields under a Canadian Intense (CI) smoking regimen. Together, these papers will provide a more robust picture of the design features that contribute to TNCO exposure across the range of real world smoking patterns.

Thermionic reactor power conditioner design for nuclear electric propulsion.

NASA Technical Reports Server (NTRS)

Jacobsen, A. S.; Tasca, D. M.

1971-01-01

Consideration of the effects of various thermionic reactor parameters and requirements upon spacecraft power conditioning design. A basic spacecraft is defined using nuclear electric propulsion, requiring approximately 120 kWe. The interrelationships of reactor operating characteristics and power conditioning requirements are discussed and evaluated, and the effects on power conditioner design and performance are presented.

A Module Experimental Process System Development Unit (MEPSDU)

NASA Technical Reports Server (NTRS)

1981-01-01

The purpose of this program is to demonstrate the technical readiness of a cost effective process sequence that has the potential for the production of flat plate photovoltaic modules which met the price goal in 1986 of $.70 or less per watt peak. Program efforts included: preliminary design review, preliminary cell fabrication using the proposed process sequence, verification of sandblasting back cleanup, study of resist parameters, evaluation of pull strength of the proposed metallization, measurement of contact resistance of Electroless Ni contacts, optimization of process parameter, design of the MEPSDU module, identification and testing of insulator tapes, development of a lamination process sequence, identification, discussions, demonstrations and visits with candidate equipment vendors, evaluation of proposals for tabbing and stringing machine.

Theoretical studies of system performance and adaptive optics design parameters

NASA Astrophysics Data System (ADS)

Tyson, Robert K.

1990-08-01

The ultimate performance of an adaptive optics (AO) system can be sensitive to specific design parameters of individual components. The type and configuration of a wavefront sensor or the shape of individual deformable mirror actuator influence functions can have a profound effect on the correctability of the AO system. This paper will discuss the results of a theoretical study which employed both closed form analytic solutions and computer models. A parametric analysis of wavefront sensor characteristics, noise, and subaperture geometry are independently evaluated against system response to an aberrated wave characteristic of atmospheric turbulence. Similarly, the shape and extent of the deformable mirror influence function and the placement and number of actuators is evaluated to characterize the effects of fitting error and coupling.

Contact Dermatitis for the Practicing Allergist.

PubMed

Bernstein, David I

2015-01-01

This article provides an overview of important practice recommendations from the recently updated Contact Dermatitis Practice Parameter. This updated parameter provides essential recommendations pertaining to clinical history, physical examination, and patch testing evaluation of patients suspected of allergic contact dermatitis. In addition to providing guidance for performing and interpreting closed patch testing, the updated parameter provides concrete recommendations for assessing metal hypersensitivity in patients receiving prosthetic devices, for evaluating workers with occupational contact dermatitis, and also for addressing allergic contact dermatitis in children. Finally, the document provides practical recommendations useful for educating patients regarding avoidance of exposure to known contact sensitizers in the home and at work. The Contact Dermatitis Parameter is designed as a practical, evidence-based clinical tool to be used by allergists and dermatologists who routinely are called upon to evaluate patients with skin disorders. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Advanced Information Systems Design: Technical Basis and Human Factors Review Guidance

DTIC Science & Technology

2000-03-01

D ., Wise, J ., and Hanes, L., "An Evaluation of Nuclear Power Plant Safety Parameter Display Systems," Proceedings of the Human Factors Society 25th...Reactor (PWR) (Source: Reprinted with permission from Woods, D ., Wise, J ., and Hanes, L., "An Evaluation of Nuclear Power Plant Safety Parameter...Dials display rpCJni?3 (b) Fluid-Tanks display B (c) Seesaw display I 72 CF \\^- J B ’ V ’II ’ ( d ) Mimic display B E * • \\ ^r 7

Land Mobile Satellite Service (LMSS) channel simulator: An end-to-end hardware simulation and study of the LMSS communications links

NASA Technical Reports Server (NTRS)

Salmasi, A. B. (Editor); Springett, J. C.; Sumida, J. T.; Richter, P. H.

1984-01-01

The design and implementation of the Land Mobile Satellite Service (LMSS) channel simulator as a facility for an end to end hardware simulation of the LMSS communications links, primarily with the mobile terminal is described. A number of studies are reported which show the applications of the channel simulator as a facility for validation and assessment of the LMSS design requirements and capabilities by performing quantitative measurements and qualitative audio evaluations for various link design parameters and channel impairments under simulated LMSS operating conditions. As a first application, the LMSS channel simulator was used in the evaluation of a system based on the voice processing and modulation (e.g., NBFM with 30 kHz of channel spacing and a 2 kHz rms frequency deviation for average talkers) selected for the Bell System's Advanced Mobile Phone Service (AMPS). The various details of the hardware design, qualitative audio evaluation techniques, signal to channel impairment measurement techniques, the justifications for criteria of different parameter selection in regards to the voice processing and modulation methods, and the results of a number of parametric studies are further described.

Architecture for space habitats. Role of architectural design in planning artificial environment for long time manned space missions

NASA Astrophysics Data System (ADS)

Martinez, Vera

2007-02-01

The paper discusses concepts about the role of architecture in the design of space habitats and the development of a general evaluation criteria of architectural design contribution. Besides the existing feasibility studies, the general requisites, the development studies, and the critical design review which are mainly based on the experience of human space missions and the standards of the NASA-STD-3000 manual and which analyze and evaluate the relation between man and environment and between man and machine mainly in its functionality, there is very few material about design of comfort and wellbeing of man in space habitat. Architecture for space habitat means the design of an artificial environment with much comfort in an "atmosphere" of wellbeing. These are mainly psychological effects of human factors which are very important in the case of a long time space mission. How can the degree of comfort and "wellbeing atmosphere" in an artificial environment be measured? How can the quality of the architectural contribution in space design be quantified? Definition of a criteria catalogue to reach a larger objectivity in architectural design evaluation. Definition of constant parameters as a result of project necessities to quantify the quality of the design. Architectural design analysis due the application and verification within the parameters and consequently overlapping and evaluating results. Interdisciplinary work between architects, astronautics, engineers, psychologists, etc. All the disciplines needed for planning a high quality habitat for humans in space. Analysis of the principles of well designed artificial environment. Good quality design for space architecture is the result of the interaction and interrelation between many different project necessities (technological, environmental, human factors, transportation, costs, etc.). Each of this necessities is interrelated in the design project and cannot be evaluated on its own. Therefore, the design process needs constant check ups to choose each time the best solution in relation to the whole. As well as for the main disciplines around human factors, architectural design for space has to be largely tested to produce scientific improvement.

Rational design of aerobic digestion systems

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

Rich, L.G.

1987-06-01

Deficiencies are identified in state-of-the-art procedures used in the design of systems for the aerobic digestion of waste-activated sludge solids. A procedure for the design of such systems on a rational basis is presented. Such a procedure not only includes a well-defined stabilization objective, but takes into account the stabilization that occurs in the activated sludge process. Related methods are discussed by which coefficients used in the design procedure can be evaluated. A design example is given. Further research and performance data derived from systems designed by the procedure are needed to better evaluate the parameters used and to testmore » the assumptions made in applying the procedure.« less

Rational design of aerobic digestion systems

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

Rich, L.G.

1987-06-01

Deficiencies are identified in state-of-the-art procedures used in the design of systems for the aerobic digestion of waste-activated sludge solids. A procedure for the design of such systems on a rational basis is presented. Such a procedure not only includes a well-defined stabilization objective, but takes into account the stabilization that occurs in the activated sludge process. Related methods are discussed by which coefficients used in the design procedure can be evaluated. A design example is given. Further research and performance data derived from systems designed by the procedure are needed to better evaluate the parameters used and to testmore » the assumptions made in applying the procedure. (Refs. 28).« less

The performance of a prototype device designed to evaluate general quality parameters of X-ray equipment

NASA Astrophysics Data System (ADS)

Murata, C. H.; Fernandes, D. C.; Lavínia, N. C.; Caldas, L. V. E.; Pires, S. R.; Medeiros, R. B.

2014-02-01

The performance of radiological equipment can be assessed using non-invasive methods and portable instruments that can analyze an X-ray beam with just one exposure. These instruments use either an ionization chamber or a state solid detector (SSD) to evaluate X-ray beam parameters. In Brazil, no such instruments are currently being manufactured; consequently, these instruments come at a higher cost to users due to importation taxes. Additionally, quality control tests are time consuming and impose a high workload on the X-ray tubes when evaluating their performance parameters. The assessment of some parameters, such as the half-value layer (HVL), requires several exposures; however, this can be reduced by using a SSD that requires only a single exposure. One such SSD uses photodiodes designed for high X-ray sensitivity without the use of scintillation crystals. This sensitivity allows one electron-hole pair to be created per 3.63 eV of incident energy, resulting in extremely high and stable quantum efficiencies. These silicon photodiodes operate by absorbing photons and generating a flow of current that is proportional to the incident power. The aim of this study was to show the response of the solid sensor PIN RD100A detector in a multifunctional X-ray analysis system that is designed to evaluate the average peak voltage (kVp), exposure time, and HVL of radiological equipment. For this purpose, a prototype board that uses four SSDs was developed to measure kVp, exposure time, and HVL using a single exposure. The reproducibility and accuracy of the results were compared to that of different X-ray beam analysis instruments. The kVp reproducibility and accuracy results were 2% and 3%, respectively; the exposure time reproducibility and accuracy results were 2% and 1%, respectively; and the HVL accuracy was ±2%. The prototype's methodology was able to calculate these parameters with appropriate reproducibility and accuracy. Therefore, the prototype can be considered a multifunctional instrument that can appropriately evaluate the performance of radiological equipment.

Analysis on design and optimization of dispersion-managed communication systems

NASA Astrophysics Data System (ADS)

El-Aasser, Mostafa A.; Dua, Puneit; Dutta, Niloy K.

2002-07-01

The variational method is a useful tool that can be used for design and optimization of dispersion-managed communication systems. Using this powerful tool, we evaluate the characteristics of a carrier signal for certain system parameters and describe several features of a dispersion-managed soliton.

Multiobjective sampling design for parameter estimation and model discrimination in groundwater solute transport

USGS Publications Warehouse

Knopman, Debra S.; Voss, Clifford I.

1989-01-01

Sampling design for site characterization studies of solute transport in porous media is formulated as a multiobjective problem. Optimal design of a sampling network is a sequential process in which the next phase of sampling is designed on the basis of all available physical knowledge of the system. Three objectives are considered: model discrimination, parameter estimation, and cost minimization. For the first two objectives, physically based measures of the value of information obtained from a set of observations are specified. In model discrimination, value of information of an observation point is measured in terms of the difference in solute concentration predicted by hypothesized models of transport. Points of greatest difference in predictions can contribute the most information to the discriminatory power of a sampling design. Sensitivity of solute concentration to a change in a parameter contributes information on the relative variance of a parameter estimate. Inclusion of points in a sampling design with high sensitivities to parameters tends to reduce variance in parameter estimates. Cost minimization accounts for both the capital cost of well installation and the operating costs of collection and analysis of field samples. Sensitivities, discrimination information, and well installation and sampling costs are used to form coefficients in the multiobjective problem in which the decision variables are binary (zero/one), each corresponding to the selection of an observation point in time and space. The solution to the multiobjective problem is a noninferior set of designs. To gain insight into effective design strategies, a one-dimensional solute transport problem is hypothesized. Then, an approximation of the noninferior set is found by enumerating 120 designs and evaluating objective functions for each of the designs. Trade-offs between pairs of objectives are demonstrated among the models. The value of an objective function for a given design is shown to correspond to the ability of a design to actually meet an objective.

Evaluation Parameters for Computer-Adaptive Testing

ERIC Educational Resources Information Center

Georgiadou, Elisabeth; Triantafillou, Evangelos; Economides, Anastasios A.

2006-01-01

With the proliferation of computers in test delivery today, adaptive testing has become quite popular, especially when examinees must be classified into two categories (passfail, master nonmaster). Several well-established organisations have provided standards and guidelines for the design and evaluation of educational and psychological testing.…

The vehicle design evaluation program - A computer-aided design procedure for transport aircraft

NASA Technical Reports Server (NTRS)

Oman, B. H.; Kruse, G. S.; Schrader, O. E.

1977-01-01

The vehicle design evaluation program is described. This program is a computer-aided design procedure that provides a vehicle synthesis capability for vehicle sizing, external load analysis, structural analysis, and cost evaluation. The vehicle sizing subprogram provides geometry, weight, and balance data for aircraft using JP, hydrogen, or methane fuels. The structural synthesis subprogram uses a multistation analysis for aerodynamic surfaces and fuselages to develop theoretical weights and geometric dimensions. The parts definition subprogram uses the geometric data from the structural analysis and develops the predicted fabrication dimensions, parts material raw stock buy requirements, and predicted actual weights. The cost analysis subprogram uses detail part data in conjunction with standard hours, realization factors, labor rates, and material data to develop the manufacturing costs. The program is used to evaluate overall design effects on subsonic commercial type aircraft due to parameter variations.

New Discrete Fibonacci Charge Pump Design, Evaluation and Measurement

NASA Astrophysics Data System (ADS)

Matoušek, David; Hospodka, Jiří; Šubrt, Ondřej

2017-06-01

This paper focuses on the practical aspects of the realisation of Dickson and Fibonacci charge pumps. Standard Dickson charge pump circuit solution and new Fibonacci charge pump implementation are compared. Both charge pumps were designed and then evaluated by LTspice XVII simulations and realised in a discrete form on printed circuit board (PCB). Finally, the key parameters as the output voltage, efficiency, rise time, variable power supply and clock frequency effects were measured.

Aircraft Maneuvers for the Evaluation of Flying Qualities and Agility. Volume 2. Maneuver Descriptions and Section Guide

DTIC Science & Technology

1993-08-01

Requirements to Design 2 Several of these maneuvers may be suitable for the development of design criteria or tactical utility studies . However, this...research was not intended to be a criteria development effort or a tactical ufiflity study . Instead, a sensitivity between each maneuver and various...utility studies because it contains measure of merit data and pilot comments for numerous desigp parameter variations. The Standard Evaluation

On predicting monitoring system effectiveness

NASA Astrophysics Data System (ADS)

Cappello, Carlo; Sigurdardottir, Dorotea; Glisic, Branko; Zonta, Daniele; Pozzi, Matteo

2015-03-01

While the objective of structural design is to achieve stability with an appropriate level of reliability, the design of systems for structural health monitoring is performed to identify a configuration that enables acquisition of data with an appropriate level of accuracy in order to understand the performance of a structure or its condition state. However, a rational standardized approach for monitoring system design is not fully available. Hence, when engineers design a monitoring system, their approach is often heuristic with performance evaluation based on experience, rather than on quantitative analysis. In this contribution, we propose a probabilistic model for the estimation of monitoring system effectiveness based on information available in prior condition, i.e. before acquiring empirical data. The presented model is developed considering the analogy between structural design and monitoring system design. We assume that the effectiveness can be evaluated based on the prediction of the posterior variance or covariance matrix of the state parameters, which we assume to be defined in a continuous space. Since the empirical measurements are not available in prior condition, the estimation of the posterior variance or covariance matrix is performed considering the measurements as a stochastic variable. Moreover, the model takes into account the effects of nuisance parameters, which are stochastic parameters that affect the observations but cannot be estimated using monitoring data. Finally, we present an application of the proposed model to a real structure. The results show how the model enables engineers to predict whether a sensor configuration satisfies the required performance.

Establishment and reliability evaluation of the design space for HPLC analysis of six alkaloids in Coptis chinensis (Huanglian) using Bayesian approach.

PubMed

Dai, Sheng-Yun; Xu, Bing; Zhang, Yi; Li, Jian-Yu; Sun, Fei; Shi, Xin-Yuan; Qiao, Yan-Jiang

2016-09-01

Coptis chinensis (Huanglian) is a commonly used traditional Chinese medicine (TCM) herb and alkaloids are the most important chemical constituents in it. In the present study, an isocratic reverse phase high performance liquid chromatography (RP-HPLC) method allowing the separation of six alkaloids in Huanglian was for the first time developed under the quality by design (QbD) principles. First, five chromatographic parameters were identified to construct a Plackett-Burman experimental design. The critical resolution, analysis time, and peak width were responses modeled by multivariate linear regression. The results showed that the percentage of acetonitrile, concentration of sodium dodecyl sulfate, and concentration of potassium phosphate monobasic were statistically significant parameters (P < 0.05). Then, the Box-Behnken experimental design was applied to further evaluate the interactions between the three parameters on selected responses. Full quadratic models were built and used to establish the analytical design space. Moreover, the reliability of design space was estimated by the Bayesian posterior predictive distribution. The optimal separation was predicted at 40% acetonitrile, 1.7 g·mL(-1) of sodium dodecyl sulfate and 0.03 mol·mL(-1) of potassium phosphate monobasic. Finally, the accuracy profile methodology was used to validate the established HPLC method. The results demonstrated that the QbD concept could be efficiently used to develop a robust RP-HPLC analytical method for Huanglian. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Demisability and survivability sensitivity to design-for-demise techniques

NASA Astrophysics Data System (ADS)

Trisolini, Mirko; Lewis, Hugh G.; Colombo, Camilla

2018-04-01

The paper is concerned with examining the effects that design-for-demise solutions can have not only on the demisability of components, but also on their survivability that is their capability to withstand impacts from space debris. First two models are introduced. A demisability model to predict the behaviour of spacecraft components during the atmospheric re-entry and a survivability model to assess the vulnerability of spacecraft structures against space debris impacts. Two indices that evaluate the level of demisability and survivability are also proposed. The two models are then used to study the sensitivity of the demisability and of the survivability indices as a function of typical design-for-demise options. The demisability and the survivability can in fact be influenced by the same design parameters in a competing fashion that is while the demisability is improved, the survivability is worsened and vice versa. The analysis shows how the design-for-demise solutions influence the demisability and the survivability independently. In addition, the effect that a solution has simultaneously on the two criteria is assessed. Results shows which, among the design-for-demise parameters mostly influence the demisability and the survivability. For such design parameters maps are presented, describing their influence on the demisability and survivability indices. These maps represent a useful tool to quickly assess the level of demisability and survivability that can be expected from a component, when specific design parameters are changed.

Prediction of contact mechanics in metal-on-metal Total Hip Replacement for parametrically comprehensive designs and loads.

PubMed

Donaldson, Finn E; Nyman, Edward; Coburn, James C

2015-07-16

Manufacturers and investigators of Total Hip Replacement (THR) bearings require tools to predict the contact mechanics resulting from diverse design and loading parameters. This study provides contact mechanics solutions for metal-on-metal (MoM) bearings that encompass the current design space and could aid pre-clinical design optimization and evaluation. Stochastic finite element (FE) simulation was used to calculate the head-on-cup contact mechanics for five thousand combinations of design and loading parameters. FE results were used to train a Random Forest (RF) surrogate model to rapidly predict the contact patch dimensions, contact area, pressures and plastic deformations for arbitrary designs and loading. In addition to widely observed polar and edge contact, FE results included ring-polar, asymmetric-polar, and transitional categories which have previously received limited attention. Combinations of design and load parameters associated with each contact category were identified. Polar contact pressures were predicted in the range of 0-200 MPa with no permanent deformation. Edge loading (with subluxation) was associated with pressures greater than 500 MPa and induced permanent deformation in 83% of cases. Transitional-edge contact (with little subluxation) was associated with intermediate pressures and permanent deformation in most cases, indicating that, even with ideal anatomical alignment, bearings may face extreme wear challenges. Surrogate models were able to accurately predict contact mechanics 18,000 times faster than FE analyses. The developed surrogate models enable rapid prediction of MoM bearing contact mechanics across the most comprehensive range of loading and designs to date, and may be useful to those performing bearing design optimization or evaluation. Published by Elsevier Ltd.

An experimental evaluation of S-duct inlet-diffuser configurations for turboprop offset gearbox applications

NASA Technical Reports Server (NTRS)

Mcdill, Paul L.

1986-01-01

A test program, utilizing a large scale model, was run in the NASA Lewis Research Center 10- by 10-ft wind tunnel to examine the influence on performance of design parameters of turboprop S-duct inlet/diffuser systems. The parametric test program investigated inlet lip thickness, inlet/diffuser cross-sectional geometry, throat design Mach number, and shaft fairing shape. The test program was run at angles of attack to 15 deg and tunnel Mach numbers to 0.35. Results of the program indicate that current design techniques can be used to design inlet/diffuser systems with acceptable total pressure recovery, but several of the design parameters, notably lip thickness (contraction ratio) and shaft fairing cross section, must be optimized to prevent excessive distortion at the compressor face.

Thermal study of bare tips with various system parameters and incision sizes.

PubMed

Osher, Robert H; Injev, Valentine P

2006-05-01

To identify major and minor surgeon-controlled parameters that affect incision temperature when performing microincision lens removal using the Alcon Infiniti Vision System. In vitro research and development laboratory, Alcon Research, Irvine, California, USA. Phacoemulsification was performed in eye-bank cadaver eyes and the following parameters evaluated: incision, duty cycle, ultrasound (US) power, aspiration flow rate (AFR), vacuum, pulse, bottle height and balanced salt solution temperature, and tip design/size. Each parameter was varied while the others remained constant. The resulting temperature of the incision and US tip was measured using a thermal camera. Major contributors to elevated incision temperature included incision size, US power, duty cycle, AFR, vacuum setting, tip design, and presence of an ophthalmic viscosurgical device (OVD). Minor contributors included pulse frequency, bottle height, and temperature of the infusate. Microincision lens removal can be performed at safe temperatures with the knowledgeable selection of surgeon-controlled parameters.

Study design considerations in evaluating environmental impacts

Treesearch

Stan T. Lebow; Paul A. Cooper; Patricia Lebow

2006-01-01

The purpose of this chapter is to make the reader aware of how choices in study parameters may influence the outcome of treated-wood environmental impact evaluations. Evaluation of the leaching and environmental accumulation of preservatives from treated wood is a complex process. and many factors can influence the results of such studies. In laboratory studies, the...

Nanoshells for photothermal therapy: a Monte-Carlo based numerical study of their design tolerance

PubMed Central

Grosges, Thomas; Barchiesi, Dominique; Kessentini, Sameh; Gréhan, Gérard; de la Chapelle, Marc Lamy

2011-01-01

The optimization of the coated metallic nanoparticles and nanoshells is a current challenge for biological applications, especially for cancer photothermal therapy, considering both the continuous improvement of their fabrication and the increasing requirement of efficiency. The efficiency of the coupling between illumination with such nanostructures for burning purposes depends unevenly on their geometrical parameters (radius, thickness of the shell) and material parameters (permittivities which depend on the illumination wavelength). Through a Monte-Carlo method, we propose a numerical study of such nanodevice, to evaluate tolerances (or uncertainty) on these parameters, given a threshold of efficiency, to facilitate the design of nanoparticles. The results could help to focus on the relevant parameters of the engineering process for which the absorbed energy is the most dependant. The Monte-Carlo method confirms that the best burning efficiency are obtained for hollow nanospheres and exhibit the sensitivity of the absorbed electromagnetic energy as a function of each parameter. The proposed method is general and could be applied in design and development of new embedded coated nanomaterials used in biomedicine applications. PMID:21698021

Design and application of an array extended blackbody

NASA Astrophysics Data System (ADS)

Zhang, Ya-zhou; Fan, Xiao-li; Lei, Hao; Zhou, Zhi-yuan

2018-02-01

An array extended blackbody is designed to quantitatively measure and evaluate the performance of infrared imaging systems. The theory, structure, control software and application of blackbody are introduced. The parameters of infrared imaging systems such as the maximum detectable range, detection sensitivity, spatial resolution and temperature resolution can be measured.

Single element injector cold flow testing for STME swirl coaxial injector element design

NASA Technical Reports Server (NTRS)

Hulka, J.; Schneider, J. A.

1993-01-01

An oxidizer-swirled coaxial element injector is being investigated for application in the Space Transportation Main Engine (STME). Single element cold flow experiments were conducted to provide characterization of the STME injector element for future analysis, design, and optimization. All tests were conducted to quiescent, ambient backpressure conditions. Spray angle, circumferential spray uniformity, dropsize, and dropsize distribution were measured in water-only and water/nitrogen flows. Rupe mixing efficiency was measured using water/sucrose solution flows with a large grid patternator for simple comparative evaluation of mixing. Factorial designs of experiment were used for statistical evaluation of injector geometrical design features and propellant flow conditions on mixing and atomization. Increasing the free swirl angle of the liquid oxidizer had the greatest influence on increasing the mixing efficiency. The addition of gas assistance had the most significant effect on reducing oxidizer droplet size parameters and increasing droplet size distribution. Increasing the oxidizer injection velocity had the greatest influence for reducing oxidizer droplet size parameters and increasing size distribution for non-gas assisted flows. Single element and multi-element subscale hot fire testing are recommended to verify optimized designs before committing to the STME design.

Hydrazine Gas Generator Program. [space shuttles

NASA Technical Reports Server (NTRS)

Kusak, L.; Marcy, R. D.

1975-01-01

The design and fabrication of a flight gas generator for the space shuttle were investigated. Critical performance parameters and stability criteria were evaluated as well as a scaling laws that could be applied in designing the flight gas generator. A test program to provide the necessary design information was included. A structural design, including thermal and stress analysis, and two gas generators were fabricated based on the results. Conclusions are presented.

Experimental Design for Stochastic Models of Nonlinear Signaling Pathways Using an Interval-Wise Linear Noise Approximation and State Estimation

PubMed Central

Zimmer, Christoph

2016-01-01

Background Computational modeling is a key technique for analyzing models in systems biology. There are well established methods for the estimation of the kinetic parameters in models of ordinary differential equations (ODE). Experimental design techniques aim at devising experiments that maximize the information encoded in the data. For ODE models there are well established approaches for experimental design and even software tools. However, data from single cell experiments on signaling pathways in systems biology often shows intrinsic stochastic effects prompting the development of specialized methods. While simulation methods have been developed for decades and parameter estimation has been targeted for the last years, only very few articles focus on experimental design for stochastic models. Methods The Fisher information matrix is the central measure for experimental design as it evaluates the information an experiment provides for parameter estimation. This article suggest an approach to calculate a Fisher information matrix for models containing intrinsic stochasticity and high nonlinearity. The approach makes use of a recently suggested multiple shooting for stochastic systems (MSS) objective function. The Fisher information matrix is calculated by evaluating pseudo data with the MSS technique. Results The performance of the approach is evaluated with simulation studies on an Immigration-Death, a Lotka-Volterra, and a Calcium oscillation model. The Calcium oscillation model is a particularly appropriate case study as it contains the challenges inherent to signaling pathways: high nonlinearity, intrinsic stochasticity, a qualitatively different behavior from an ODE solution, and partial observability. The computational speed of the MSS approach for the Fisher information matrix allows for an application in realistic size models. PMID:27583802

Analysis of the design and performance characteristics of pumpable roof supports

PubMed Central

Timothy, Batchler

2017-01-01

Pumpable roof supports are currently being used to provide a safe working environment for longwall mining. Because different pumpable supports are visually similar and installed fundamentally in the same manner as other supports, there is a tendency to believe they all perform the same way. However, there are several design parameters that can affect their performance, including the cementitious material properties and the bag construction practices that influence the degree of confinement provided. A full understanding of the impact of these design parameters is necessary to optimize the support application and to provide a foundation for making further improvements in the support performance. This paper evaluates the impact of various support design parameters by examining full-scale performance tests conducted using the National Institute for Occupational Safety and Health (NIOSH) Mine Roof Simulator (MRS) as part of manufacturers’ developmental and quality control testing. These tests were analyzed to identify correlations between the support design parameters and the resulting performance. Based on more than 160 tests over 7 years, quantifiable patterns were examined to assess the correlation between the support dimensions, cementitious material type, wire pitch, and single-wall vs. dual-walled bag designs to the support capacity, stiffness, load shedding events, and yield characteristics. PMID:28775910

Developments in Sensitivity Methodologies and the Validation of Reactor Physics Calculations

DOE PAGES

Palmiotti, Giuseppe; Salvatores, Massimo

2012-01-01

The sensitivity methodologies have been a remarkable story when adopted in the reactor physics field. Sensitivity coefficients can be used for different objectives like uncertainty estimates, design optimization, determination of target accuracy requirements, adjustment of input parameters, and evaluations of the representativity of an experiment with respect to a reference design configuration. A review of the methods used is provided, and several examples illustrate the success of the methodology in reactor physics. A new application as the improvement of nuclear basic parameters using integral experiments is also described.

A computer simulation of an adaptive noise canceler with a single input

NASA Astrophysics Data System (ADS)

Albert, Stuart D.

1991-06-01

A description of an adaptive noise canceler using Widrows' LMS algorithm is presented. A computer simulation of canceler performance (adaptive convergence time and frequency transfer function) was written for use as a design tool. The simulations, assumptions, and input parameters are described in detail. The simulation is used in a design example to predict the performance of an adaptive noise canceler in the simultaneous presence of both strong and weak narrow-band signals (a cosited frequency hopping radio scenario). On the basis of the simulation results, it is concluded that the simulation is suitable for use as an adaptive noise canceler design tool; i.e., it can be used to evaluate the effect of design parameter changes on canceler performance.

Evaluation of GaAs low noise and power MMIC technologies to neutron, ionizing dose and dose rate effects

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

Derewonko, H.; Bosella, A.; Pataut, G.

1996-06-01

An evaluation program of Thomson CSF-TCS GaAs low noise and power MMIC technologies to 1 MeV equivalent neutron fluence levels, up to 1 {times} 10{sup 15} n/cm{sup 2}, ionizing 1.17--1.33 MeV CO{sup 60} dose levels in excess of 200 Mrad(GaAs) and dose rate levels reaching 1.89 {times} 10{sup 11} rad(GaAs)/s is presented in terms of proper components and parameter choices, DC/RF electrical measurements and test methods under irradiation. Experimental results are explained together with drift analyses of electrical parameters that have determined threshold limits of component degradations. Modelling the effects of radiation on GaAs components relies on degradation analysis ofmore » active layer which appears to be the most sensitive factor. MMICs degradation under neutron fluence was simulated from irradiated FET data. Finally, based on sensitivity of technological parameters, rad-hard design including material, technology and MMIC design enhancement is discussed.« less

Study of parameter identification using hybrid neural-genetic algorithm in electro-hydraulic servo system

NASA Astrophysics Data System (ADS)

Moon, Byung-Young

2005-12-01

The hybrid neural-genetic multi-model parameter estimation algorithm was demonstrated. This method can be applied to structured system identification of electro-hydraulic servo system. This algorithms consist of a recurrent incremental credit assignment(ICRA) neural network and a genetic algorithm. The ICRA neural network evaluates each member of a generation of model and genetic algorithm produces new generation of model. To evaluate the proposed method, electro-hydraulic servo system was designed and manufactured. The experiment was carried out to figure out the hybrid neural-genetic multi-model parameter estimation algorithm. As a result, the dynamic characteristics were obtained such as the parameters(mass, damping coefficient, bulk modulus, spring coefficient), which minimize total square error. The result of this study can be applied to hydraulic systems in industrial fields.

Correlation of Electric Field and Critical Design Parameters for Ferroelectric Tunable Microwave Filters

NASA Technical Reports Server (NTRS)

Subramanyam, Guru; VanKeuls, Fred W.; Miranda, Felix A.; Canedy, Chadwick L.; Aggarwal, Sanjeev; Venkatesan, Thirumalai; Ramesh, Ramamoorthy

2000-01-01

The correlation of electric field and critical design parameters such as the insertion loss, frequency ability return loss, and bandwidth of conductor/ferroelectric/dielectric microstrip tunable K-band microwave filters is discussed in this work. This work is based primarily on barium strontium titanate (BSTO) ferroelectric thin film based tunable microstrip filters for room temperature applications. Two new parameters which we believe will simplify the evaluation of ferroelectric thin films for tunable microwave filters, are defined. The first of these, called the sensitivity parameter, is defined as the incremental change in center frequency with incremental change in maximum applied electric field (EPEAK) in the filter. The other, the loss parameter, is defined as the incremental or decremental change in insertion loss of the filter with incremental change in maximum applied electric field. At room temperature, the Au/BSTO/LAO microstrip filters exhibited a sensitivity parameter value between 15 and 5 MHz/cm/kV. The loss parameter varied for different bias configurations used for electrically tuning the filter. The loss parameter varied from 0.05 to 0.01 dB/cm/kV at room temperature.

Investigation of designated eye position and viewing zone for a two-view autostereoscopic display.

PubMed

Huang, Kuo-Chung; Chou, Yi-Heng; Lin, Lang-chin; Lin, Hoang Yan; Chen, Fu-Hao; Liao, Ching-Chiu; Chen, Yi-Han; Lee, Kuen; Hsu, Wan-Hsuan

2014-02-24

Designated eye position (DEP) and viewing zone (VZ) are important optical parameters for designing a two-view autostereoscopic display. Although much research has been done to date, little empirical evidence has been found to establish a direct relationship between design and measurement. More rigorous studies and verifications to investigate DEP and to ascertain the VZ criterion will be valuable. We propose evaluation metrics based on equivalent luminance (EL) and binocular luminance (BL) to figure out DEP and VZ for a two-view autostereoscopic display. Simulation and experimental results prove that our proposed evaluation metrics can be used to find the DEP and VZ accurately.

Optimum systems design with random input and output applied to solar water heating

NASA Astrophysics Data System (ADS)

Abdel-Malek, L. L.

1980-03-01

Solar water heating systems are evaluated. Models were developed to estimate the percentage of energy supplied from the Sun to a household. Since solar water heating systems have random input and output queueing theory, birth and death processes were the major tools in developing the models of evaluation. Microeconomics methods help in determining the optimum size of the solar water heating system design parameters, i.e., the water tank volume and the collector area.

Photoacoustic design parameter optimization for deep tissue imaging by numerical simulation

NASA Astrophysics Data System (ADS)

Wang, Zhaohui; Ha, Seunghan; Kim, Kang

2012-02-01

A new design of light illumination scheme for deep tissue photoacoustic (PA) imaging, a light catcher, is proposed and evaluated by in silico simulation. Finite element (FE)-based numerical simulation model was developed for photoacoustic (PA) imaging in soft tissues. In this in silico simulation using a commercially available FE simulation package (COMSOL MultiphysicsTM, COMSOL Inc., USA), a short-pulsed laser point source (pulse length of 5 ns) was placed in water on the tissue surface. Overall, four sets of simulation models were integrated together to describe the physical principles of PA imaging. Light energy transmission through background tissues from the laser source to the target tissue or contrast agent was described by diffusion equation. The absorption of light energy and its conversion to heat by target tissue or contrast agent was modeled using bio-heat equation. The heat then causes the stress and strain change, and the resulting displacement of the target surface produces acoustic pressure. The created wide-band acoustic pressure will propagate through background tissues to the ultrasound detector, which is governed by acoustic wave equation. Both optical and acoustical parameters in soft tissues such as scattering, absorption, and attenuation are incorporated in tissue models. PA imaging performance with different design parameters of the laser source and energy delivery scheme was investigated. The laser light illumination into the deep tissues can be significantly improved by up to 134.8% increase of fluence rate by introducing a designed compact light catcher with highly reflecting inner surface surrounding the light source. The optimized parameters through this simulation will guide the design of PA system for deep tissue imaging, and help to form the base protocols of experimental evaluations in vitro and in vivo.

Design of a compliant wheel for a miniature rover to be used on Mars

NASA Astrophysics Data System (ADS)

Carroll, Mark; Johnson, Jess; Yong, Jimmy

1991-12-01

The Jet Propulsion Laboratory has identified the need for a compliant wheel for a miniature martian rover vehicle. This wheel must meet requirements of minimum mass, linear radial deflection, and reliability in cryogenic conditions over a five year lifespan. Additionally, axial and tangential deflections must be no more than 10 percent of the radial value. The team designed a wheel by use of finite element and dimensionless parameter analysis. Due to the complex geometry of the wheel, a finite element model describing its behavior was constructed to investigate different wheel configurations. Axial and tangential deflections were greatly reduced but did not meet design criteria. A composite material was selected for its high strength, toughness, fatigue resistance, and damping characteristics. The team chose a Kevlar fiber filled thermoplastic composite. This report is divided into four primary sections. First, the introduction section gives background information, defines the task, and discusses the scope and limitations of the project. Second, the alternative designs section introduces alternative design solutions, addresses advantages and disadvantages of each, and identifies the parameters used to determine the best design. Third, the design solution section introduces the methods used to evaluate the alternates, and gives a description of the design process used. Finally, the conclusion and recommendations section evaluates the wheel design, and offers recommendations pertaining to improvement of the design solution.

Design of a compliant wheel for a miniature rover to be used on Mars

NASA Technical Reports Server (NTRS)

Carroll, Mark; Johnson, Jess; Yong, Jimmy

1991-01-01

The Jet Propulsion Laboratory has identified the need for a compliant wheel for a miniature martian rover vehicle. This wheel must meet requirements of minimum mass, linear radial deflection, and reliability in cryogenic conditions over a five year lifespan. Additionally, axial and tangential deflections must be no more than 10 percent of the radial value. The team designed a wheel by use of finite element and dimensionless parameter analysis. Due to the complex geometry of the wheel, a finite element model describing its behavior was constructed to investigate different wheel configurations. Axial and tangential deflections were greatly reduced but did not meet design criteria. A composite material was selected for its high strength, toughness, fatigue resistance, and damping characteristics. The team chose a Kevlar fiber filled thermoplastic composite. This report is divided into four primary sections. First, the introduction section gives background information, defines the task, and discusses the scope and limitations of the project. Second, the alternative designs section introduces alternative design solutions, addresses advantages and disadvantages of each, and identifies the parameters used to determine the best design. Third, the design solution section introduces the methods used to evaluate the alternates, and gives a description of the design process used. Finally, the conclusion and recommendations section evaluates the wheel design, and offers recommendations pertaining to improvement of the design solution.

Development of a design basis tornado and structural design criteria for the Nevada Test Site, Nevada. Final report

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

McDonald, J.R.; Minor, J.E.; Mehta, K.C.

1975-06-01

In order to evaluate the ability of critical facilities at the Nevada Test Site to withstand the possible damaging effects of extreme winds and tornadoes, parameters for the effects of tornadoes and extreme winds and structural design criteria for the design and evaluation of structures were developed. The meteorological investigations conducted are summarized, and techniques used for developing the combined tornado and extreme wind risk model are discussed. The guidelines for structural design include methods for calculating pressure distributions on walls and roofs of structures and methods for accommodating impact loads from wind-driven missiles. Calculations for determining the design loadsmore » for an example structure are included. (LCL)« less

Primary lithium organic electrolyte battery BA-5588

NASA Astrophysics Data System (ADS)

Rosansky, M. G.

1982-07-01

This program concerns the development, fabrication and evaluation of a Lithium organic electrolyte battery designated BA-5588 ()/U which incorporates five series connected, hermetically sealed cells housed in a plastic case. Significant effort was directed towards cell optimization through controlled experimentation and evaluation of various design parameters. Demonstration of the effectiveness of the finalized design was accomplished by the performance of various electrical and abuse tests which included environmental exposure, prolonged thermal storage, electrical discharge under various thermal profiles, short circuit and discharge to zero volts as well as forced discharge. The resulting evaluation demonstrated the batteries ability to operate safely under all of the specified abusive environments and provide 100% of the specified service life requirements.

Optimising sulfuric acid hard coat anodising for an Al-Mg-Si wrought aluminium alloy

NASA Astrophysics Data System (ADS)

Bartolo, N.; Sinagra, E.; Mallia, B.

2014-06-01

This research evaluates the effects of sulfuric acid hard coat anodising parameters, such as acid concentration, electrolyte temperature, current density and time, on the hardness and thickness of the resultant anodised layers. A small scale anodising facility was designed and set up to enable experimental investigation of the anodising parameters. An experimental design using the Taguchi method to optimise the parameters within an established operating window was performed. Qualitative and quantitative methods of characterisation of the resultant anodised layers were carried out. The anodised layer's thickness, and morphology were determined using a light optical microscope (LOM) and field emission gun scanning electron microscope (FEG-SEM). Hardness measurements were carried out using a nano hardness tester. Correlations between the various anodising parameters and their effect on the hardness and thickness of the anodised layers were established. Careful evaluation of these effects enabled optimum parameters to be determined using the Taguchi method, which were verified experimentally. Anodised layers having hardness varying between 2.4-5.2 GPa and a thickness of between 20-80 μm were produced. The Taguchi method was shown to be applicable to anodising. This finding could facilitate on-going and future research and development of anodising, which is attracting remarkable academic and industrial interest.

Evaluation of powertrain solutions for future tactical truck vehicle systems

NASA Astrophysics Data System (ADS)

Pisu, Pierluigi; Cantemir, Codrin-Gruie; Dembski, Nicholas; Rizzoni, Giorgio; Serrao, Lorenzo; Josephson, John R.; Russell, James

2006-05-01

The article presents the results of a large scale design space exploration for the hybridization of two off-road vehicles, part of the Future Tactical Truck System (FTTS) family: Maneuver Sustainment Vehicle (MSV) and Utility Vehicle (UV). Series hybrid architectures are examined. The objective of the paper is to illustrate a novel design methodology that allows for the choice of the optimal values of several vehicle parameters. The methodology consists in an extensive design space exploration, which involves running a large number of computer simulations with systematically varied vehicle design parameters, where each variant is paced through several different mission profiles, and multiple attributes of performance are measured. The resulting designs are filtered to choose the design tradeoffs that better satisfy the performance and fuel economy requirements. At the end, few promising vehicle configuration designs will be selected that will need additional detailed investigation including neglected metrics like ride and drivability. Several powertrain architectures have been simulated. The design parameters include the number of axles in the vehicle (2 or 3), the number of electric motors per axle (1 or 2), the type of internal combustion engine, the type and quantity of energy storage system devices (batteries, electrochemical capacitors or both together). An energy management control strategy has also been developed to provide efficiency and performance. The control parameters are tunable and have been included into the design space exploration. The results show that the internal combustion engine and the energy storage system devices are extremely important for the vehicle performance.

Structural dynamic analysis of the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Scott, L. P.; Jamison, G. T.; Mccutcheon, W. A.; Price, J. M.

1981-01-01

This structural dynamic analysis supports development of the SSME by evaluating components subjected to critical dynamic loads, identifying significant parameters, and evaluating solution methods. Engine operating parameters at both rated and full power levels are considered. Detailed structural dynamic analyses of operationally critical and life limited components support the assessment of engine design modifications and environmental changes. Engine system test results are utilized to verify analytic model simulations. The SSME main chamber injector assembly is an assembly of 600 injector elements which are called LOX posts. The overall LOX post analysis procedure is shown.

Parameter and observation importance in modelling virus transport in saturated porous media - Investigations in a homogenous system

USGS Publications Warehouse

Barth, Gilbert R.; Hill, M.C.

2005-01-01

This paper evaluates the importance of seven types of parameters to virus transport: hydraulic conductivity, porosity, dispersivity, sorption rate and distribution coefficient (representing physical-chemical filtration), and in-solution and adsorbed inactivation (representing virus inactivation). The first three parameters relate to subsurface transport in general while the last four, the sorption rate, distribution coefficient, and in-solution and adsorbed inactivation rates, represent the interaction of viruses with the porous medium and their ability to persist. The importance of four types of observations to estimate the virus-transport parameters are evaluated: hydraulic heads, flow, temporal moments of conservative-transport concentrations, and virus concentrations. The evaluations are conducted using one- and two-dimensional homogeneous simulations, designed from published field experiments, and recently developed sensitivity-analysis methods. Sensitivity to the transport-simulation time-step size is used to evaluate the importance of numerical solution difficulties. Results suggest that hydraulic conductivity, porosity, and sorption are most important to virus-transport predictions. Most observation types provide substantial information about hydraulic conductivity and porosity; only virus-concentration observations provide information about sorption and inactivation. The observations are not sufficient to estimate these important parameters uniquely. Even with all observation types, there is extreme parameter correlation between porosity and hydraulic conductivity and between the sorption rate and in-solution inactivation. Parameter estimation was accomplished by fixing values of porosity and in-solution inactivation.

Planning Coverage Campaigns for Mission Design and Analysis: CLASP for DESDynl

NASA Technical Reports Server (NTRS)

Knight, Russell L.; McLaren, David A.; Hu, Steven

2013-01-01

Mission design and analysis presents challenges in that almost all variables are in constant flux, yet the goal is to achieve an acceptable level of performance against a concept of operations, which might also be in flux. To increase responsiveness, automated planning tools are used that allow for the continual modification of spacecraft, ground system, staffing, and concept of operations, while returning metrics that are important to mission evaluation, such as area covered, peak memory usage, and peak data throughput. This approach was applied to the DESDynl mission design using the CLASP planning system, but since this adaptation, many techniques have changed under the hood for CLASP, and the DESDynl mission concept has undergone drastic changes. The software produces mission evaluation products, such as memory highwater marks, coverage percentages, given a mission design in the form of coverage targets, concept of operations, spacecraft parameters, and orbital parameters. It tries to overcome the lack of fidelity and timeliness of mission requirements coverage analysis during mission design. Previous techniques primarily use Excel in ad hoc fashion to approximate key factors in mission performance, often falling victim to overgeneralizations necessary in such an adaptation. The new program allows designers to faithfully represent their mission designs quickly, and get more accurate results just as quickly.

Wing optimization for space shuttle orbiter vehicles

NASA Technical Reports Server (NTRS)

Surber, T. E.; Bornemann, W. E.; Miller, W. D.

1972-01-01

The results were presented of a parametric study performed to determine the optimum wing geometry for a proposed space shuttle orbiter. The results of the study establish the minimum weight wing for a series of wing-fuselage combinations subject to constraints on aerodynamic heating, wing trailing edge sweep, and wing over-hang. The study consists of a generalized design evaluation which has the flexibility of arbitrarily varying those wing parameters which influence the vehicle system design and its performance. The study is structured to allow inputs of aerodynamic, weight, aerothermal, structural and material data in a general form so that the influence of these parameters on the design optimization process can be isolated and identified. This procedure displays the sensitivity of the system design of variations in wing geometry. The parameters of interest are varied in a prescribed fashion on a selected fuselage and the effect on the total vehicle weight is determined. The primary variables investigated are: wing loading, aspect ratio, leading edge sweep, thickness ratio, and taper ratio.

Design considerations of high-performance InGaAs/InP single-photon avalanche diodes for quantum key distribution.

PubMed

Ma, Jian; Bai, Bing; Wang, Liu-Jun; Tong, Cun-Zhu; Jin, Ge; Zhang, Jun; Pan, Jian-Wei

2016-09-20

InGaAs/InP single-photon avalanche diodes (SPADs) are widely used in practical applications requiring near-infrared photon counting such as quantum key distribution (QKD). Photon detection efficiency and dark count rate are the intrinsic parameters of InGaAs/InP SPADs, due to the fact that their performances cannot be improved using different quenching electronics given the same operation conditions. After modeling these parameters and developing a simulation platform for InGaAs/InP SPADs, we investigate the semiconductor structure design and optimization. The parameters of photon detection efficiency and dark count rate highly depend on the variables of absorption layer thickness, multiplication layer thickness, excess bias voltage, and temperature. By evaluating the decoy-state QKD performance, the variables for SPAD design and operation can be globally optimized. Such optimization from the perspective of specific applications can provide an effective approach to design high-performance InGaAs/InP SPADs.

Preliminary design of a mini-Brayton Compressor-Alternator-Turbine (CAT)

NASA Technical Reports Server (NTRS)

1973-01-01

The preliminary design of a mini-Brayton compressor-alternator-turbine system is discussed. The program design goals are listed. The optimum system characteristics over the entire range of power output were determined by performing a wide-range parametric study. The ability to develop the required components to the degree necessary within the limitations of present technology is evaluated. The sensitivity of the system to various individual design parameters was analyzed.

40 CFR 63.7941 - How do I conduct a performance test, design evaluation, or other type of initial compliance...

Code of Federal Regulations, 2011 CFR

2011-07-01

... evaluation, you must collect the appropriate operating parameter monitoring system data, average the... 760 °C or higher. (f) You must conduct a performance evaluation for each continuous monitoring system... Level 1 controls, § 63.1063(d) for Tank Level 2 controls, § 63.926(a) for Container Level 1 controls...

40 CFR 63.7941 - How do I conduct a performance test, design evaluation, or other type of initial compliance...

Code of Federal Regulations, 2013 CFR

2013-07-01

... evaluation, you must collect the appropriate operating parameter monitoring system data, average the... 760 °C or higher. (f) You must conduct a performance evaluation for each continuous monitoring system... Level 1 controls, § 63.1063(d) for Tank Level 2 controls, § 63.926(a) for Container Level 1 controls...

40 CFR 63.7941 - How do I conduct a performance test, design evaluation, or other type of initial compliance...

Code of Federal Regulations, 2012 CFR

2012-07-01

... evaluation, you must collect the appropriate operating parameter monitoring system data, average the... 760 °C or higher. (f) You must conduct a performance evaluation for each continuous monitoring system... Level 1 controls, § 63.1063(d) for Tank Level 2 controls, § 63.926(a) for Container Level 1 controls...

META-X Design Flow Tools

DTIC Science & Technology

2013-04-01

Forces can be computed at specific angular positions, and geometrical parameters can be evaluated. Much higher resolution models are required, along...composition engines (C#, C++, Python, Java ) Desert operates on the CyPhy model, converting from a design space alternative structure to a set of design...consists of scripts to execute dymola, post-processing of results to create metrics, and general management of the job sequence. An earlier version created

Optimum Design Parameters of Box Window DSF Office at Different Glazing Types under Sub Interval of Intermediate Sky Conditions (20-40 klux)

NASA Astrophysics Data System (ADS)

Elayeb, O. K.; Alghoul, M. A.; Sopian, K.; Khrita, N. G.

2017-11-01

Despite Double skin façade (DSF) buildings are widely deployed worldwide, daylighting strategy is not commonly incorporated in these buildings compare to other strategies. Therefore, further theoretical and experimental studies would lead to adopting daylighting strategy in DSF office buildings. The aim of this study is to investigate the daylighting performance of office building at different design parameters of box window DSF using different glazing types under sub interval of intermediate sky conditions (20-40) klux using the (IES VE) simulation tool from Integrated Environmental Solutions - Virtual Environment. The implemented design parameters are window wall ratio (WWR) of internal façade (10-100) %, cavity depth (CD) of DSF (1-2.5) m and different glazing types. The glazing types were selected from the list available in the (IES VE) simulation tool. After series of evaluations, bronze tinted coating (STOPSOL) is implemented for the exterior façade while clear float, clear reflective coating (STOPSOL), grey and brown tinted coating (Anti-sun float) and blue coating tinted (SUNCOOL float) are implemented for the interior façade. In this paper, several evaluation parameters are used to quantify the optimum design parameters that would balance the daylighting requirements of a box window DSF office versus sky conditions range (20-40) klux. The optimum design parameters of DSF office building obtained under different glazing types are highlighted as follows. When using bronze tinted coating (STOPSOL) for the exterior façade, the glazing types of interior façade that showed superior daylighting performance of DSF office at (CD of 1.0m with WWR of 70%), (CD of 1.5m with WWR of 70%), (CD of 2.0m with WWR of 70%) and (CD of 2.0m with WWR of 70%) are grey tinted coating (Anti-sun float), clear reflective coating (STOPSOL), brown tinted coating (Anti-sun float), and clear float glazing respectively. Blue Coating tinted (SUNCOOL float) of interior façade glazing failed to meet outstanding daylighting performance at any cavity depth.

A simplified design of the staggered herringbone micromixer for practical applications

PubMed Central

Du, Yan; Zhang, Zhiyi; Yim, ChaeHo; Lin, Min; Cao, Xudong

2010-01-01

We demonstrated a simple method for the device design of a staggered herringbone micromixer (SHM) using numerical simulation. By correlating the simulated concentrations with channel length, we obtained a series of concentration versus channel length profiles, and used mixing completion length Lm as the only parameter to evaluate the performance of device structure on mixing. Fluorescence quenching experiments were subsequently conducted to verify the optimized SHM structure for a specific application. Good agreement was found between the optimization and the experimental data. Since Lm is straightforward, easily defined and calculated parameter for characterization of mixing performance, this method for designing micromixers is simple and effective for practical applications. PMID:20697584

A simplified design of the staggered herringbone micromixer for practical applications.

PubMed

Du, Yan; Zhang, Zhiyi; Yim, Chaeho; Lin, Min; Cao, Xudong

2010-05-07

We demonstrated a simple method for the device design of a staggered herringbone micromixer (SHM) using numerical simulation. By correlating the simulated concentrations with channel length, we obtained a series of concentration versus channel length profiles, and used mixing completion length L(m) as the only parameter to evaluate the performance of device structure on mixing. Fluorescence quenching experiments were subsequently conducted to verify the optimized SHM structure for a specific application. Good agreement was found between the optimization and the experimental data. Since L(m) is straightforward, easily defined and calculated parameter for characterization of mixing performance, this method for designing micromixers is simple and effective for practical applications.

Graphical Evaluation of the Ridge-Type Robust Regression Estimators in Mixture Experiments

PubMed Central

Erkoc, Ali; Emiroglu, Esra

2014-01-01

In mixture experiments, estimation of the parameters is generally based on ordinary least squares (OLS). However, in the presence of multicollinearity and outliers, OLS can result in very poor estimates. In this case, effects due to the combined outlier-multicollinearity problem can be reduced to certain extent by using alternative approaches. One of these approaches is to use biased-robust regression techniques for the estimation of parameters. In this paper, we evaluate various ridge-type robust estimators in the cases where there are multicollinearity and outliers during the analysis of mixture experiments. Also, for selection of biasing parameter, we use fraction of design space plots for evaluating the effect of the ridge-type robust estimators with respect to the scaled mean squared error of prediction. The suggested graphical approach is illustrated on Hald cement data set. PMID:25202738

Graphical evaluation of the ridge-type robust regression estimators in mixture experiments.

PubMed

Erkoc, Ali; Emiroglu, Esra; Akay, Kadri Ulas

2014-01-01

In mixture experiments, estimation of the parameters is generally based on ordinary least squares (OLS). However, in the presence of multicollinearity and outliers, OLS can result in very poor estimates. In this case, effects due to the combined outlier-multicollinearity problem can be reduced to certain extent by using alternative approaches. One of these approaches is to use biased-robust regression techniques for the estimation of parameters. In this paper, we evaluate various ridge-type robust estimators in the cases where there are multicollinearity and outliers during the analysis of mixture experiments. Also, for selection of biasing parameter, we use fraction of design space plots for evaluating the effect of the ridge-type robust estimators with respect to the scaled mean squared error of prediction. The suggested graphical approach is illustrated on Hald cement data set.

Three types of solid state remote power controllers

NASA Technical Reports Server (NTRS)

Baker, D. E.

1975-01-01

Three types of solid state Remote Power Controller (RPC) circuits for 120 Vdc spacecraft distribution systems have been developed and evaluated. Both current limiting and noncurrent limiting modes of overload protection were developed and were demonstrated to be feasible. A second generation of circuits was developed which offers comparable performance with substantially less cost and complexity. Electrical efficiency for both generations is 98.5 to 99%. This paper describes various aspects of the circuit design, trade-off studies, and experimental test results. Comparisons of design parameters, component requirements, and engineering model evaluations will emphasize the high efficiency and reliability of the designs.

The Specification of Causal Models with Tetrad IV: A Review

ERIC Educational Resources Information Center

Landsheer, J. A.

2010-01-01

Tetrad IV is a program designed for the specification of causal models. It is specifically designed to search for causal relations, but also offers the possibility to estimate the parameters of a structural equation model. It offers a remarkable graphical user interface, which facilitates building, evaluating, and searching for causal models. The…

Mechanism and design of intermittent aeration activated sludge process for nitrogen removal.

PubMed

Hanhan, Oytun; Insel, Güçlü; Yagci, Nevin Ozgur; Artan, Nazik; Orhon, Derin

2011-01-01

The paper provided a comprehensive evaluation of the mechanism and design of intermittent aeration activated sludge process for nitrogen removal. Based on the specific character of the process the total cycle time, (T(C)), the aerated fraction, (AF), and the cycle time ratio, (CTR) were defined as major design parameters, aside from the sludge age of the system. Their impact on system performance was evaluated by means of process simulation. A rational design procedure was developed on the basis of basic stochiometry and mass balance related to the oxidation and removal of nitrogen under aerobic and anoxic conditions, which enabled selected of operation parameters of optimum performance. The simulation results indicated that the total nitrogen level could be reduced to a minimum level by appropriate manipulation of the aerated fraction and cycle time ratio. They also showed that the effluent total nitrogen could be lowered to around 4.0 mgN/L by adjusting the dissolved oxygen set-point to 0.5 mg/L, a level which promotes simultaneous nitrification and denitrification.

Thermal design of composite materials high temperature attachments

NASA Technical Reports Server (NTRS)

1972-01-01

The thermal aspects of using filamentary composite materials as primary airframe structures on advanced atmospheric entry spacecraft such as the space shuttle vehicle were investigated to identify and evaluate potential design approaches for maintaining composite structures within allowable temperature limits at thermal protection system (TPS) attachments and/or penetrations. The investigation included: (1) definition of thermophysical data for composite material structures; (2) parametric characterization and identification of the influence of the aerodynamic heating and attachment design parameters on composite material temperatures; (3) conceptual design, evaluation, and detailed thermal analyses of temperature limiting design concepts; and (4) the development of experimental data for assessment of the thermal design methodologies and data used for evaluation of the temperature-limiting design concepts. Temperature suppression attachment concepts were examined for relative merit. The simple isolator was identified as the most weight-effective concept and was selected for detail design, thermal analysis, and testing. Tests were performed on TPS standoff attachments to boron/aluminum, boron/polyimide and graphite/epoxy composite structures.

Workload-Driven Design and Evaluation of Large-Scale Data-Centric Systems

DTIC Science & Technology

2012-05-09

in the batch zone in and out of a low-power state, e.g., sending a “ hibernate ” command via ssh and using Wake-on-LAN or related technologies [85]. If...parameter values for experiments with stand-alone jobs. The mapred.child.java.opts parameter sets the maximum virtual memory of the Java child pro- cesses

Design parameters of a miniaturized piezoelectric underwater acoustic transmitter.

PubMed

Li, Huidong; Deng, Zhiqun Daniel; Yuan, Yong; Carlson, Thomas J

2012-01-01

PZT ceramics have been widely used in underwater acoustic transducers. However, literature available discussing the design parameters of a miniaturized PZT-based low-duty-cycle transmitter is very limited. This paper discusses some of the design parameters--the backing material, driving voltage, PZT material type, power consumption and the transducer length of a miniaturized acoustic fish tag using a PZT tube. Four different types of PZT were evaluated with respect to the source level, energy consumption and bandwidth of the transducer. The effect of the tube length on the source level is discussed. The results demonstrate that ultralow-density closed-cell foam is the best backing material for the PZT tube. The Navy Type VI PZTs provide the best source level with relatively low energy consumption and that a low transducer capacitance is preferred for high efficiency. A 35% reduction in the transducer length results in 2 dB decrease in source level.

Numerical method to determine mechanical parameters of engineering design in rock masses.

PubMed

Xue, Ting-He; Xiang, Yi-Qiang; Guo, Fa-Zhong

2004-07-01

This paper proposes a new continuity model for engineering in rock masses and a new schematic method for reporting the engineering of rock continuity. This method can be used to evaluate the mechanics of every kind of medium; and is a new way to determine the mechanical parameters used in engineering design in rock masses. In the numerical simulation, the experimental parameters of intact rock were combined with the structural properties of field rock. The experimental results for orthogonally-jointed rock are given. The results included the curves of the stress-strain relationship of some rock masses, the curve of the relationship between the dimension Delta and the uniaxial pressure-resistant strength sc of these rock masses, and pictures of the destructive procedure of some rock masses in uniaxial or triaxial tests, etc. Application of the method to engineering design in rock masses showed the potential of its application to engineering practice.

A Modified Penalty Parameter Approach for Optimal Estimation of UH with Simultaneous Estimation of Infiltration Parameters

NASA Astrophysics Data System (ADS)

Bhattacharjya, Rajib Kumar

2018-05-01

The unit hydrograph and the infiltration parameters of a watershed can be obtained from observed rainfall-runoff data by using inverse optimization technique. This is a two-stage optimization problem. In the first stage, the infiltration parameters are obtained and the unit hydrograph ordinates are estimated in the second stage. In order to combine this two-stage method into a single stage one, a modified penalty parameter approach is proposed for converting the constrained optimization problem to an unconstrained one. The proposed approach is designed in such a way that the model initially obtains the infiltration parameters and then searches the optimal unit hydrograph ordinates. The optimization model is solved using Genetic Algorithms. A reduction factor is used in the penalty parameter approach so that the obtained optimal infiltration parameters are not destroyed during subsequent generation of genetic algorithms, required for searching optimal unit hydrograph ordinates. The performance of the proposed methodology is evaluated by using two example problems. The evaluation shows that the model is superior, simple in concept and also has the potential for field application.

Additive Manufacturing of Fuel Injectors

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

Sadek Tadros, Dr. Alber Alphonse; Ritter, Dr. George W.; Drews, Charles Donald

Additive manufacturing (AM), also known as 3D-printing, has been shifting from a novelty prototyping paradigm to a legitimate manufacturing tool capable of creating components for highly complex engineered products. An emerging AM technology for producing metal parts is the laser powder bed fusion (L-PBF) process; however, industry manufacturing specifications and component design practices for L-PBF have not yet been established. Solar Turbines Incorporated (Solar), an industrial gas turbine manufacturer, has been evaluating AM technology for development and production applications with the desire to enable accelerated product development cycle times, overall turbine efficiency improvements, and supply chain flexibility relative to conventionalmore » manufacturing processes (casting, brazing, welding). Accordingly, Solar teamed with EWI on a joint two-and-a-half-year project with the goal of developing a production L-PBF AM process capable of consistently producing high-nickel alloy material suitable for high temperature gas turbine engine fuel injector components. The project plan tasks were designed to understand the interaction of the process variables and their combined impact on the resultant AM material quality. The composition of the high-nickel alloy powders selected for this program met the conventional cast Hastelloy X compositional limits and were commercially available in different particle size distributions (PSD) from two suppliers. Solar produced all the test articles and both EWI and Solar shared responsibility for analyzing them. The effects of powder metal input stock, laser parameters, heat treatments, and post-finishing methods were evaluated. This process knowledge was then used to generate tensile, fatigue, and creep material properties data curves suitable for component design activities. The key process controls for ensuring consistent material properties were documented in AM powder and process specifications. The basic components of the project were: • Powder metal input stock: Powder characterization, dimensional accuracy, metallurgical characterization, and mechanical properties evaluation. • Process parameters: Laser parameter effects, post-printing heat-treatment development, mechanical properties evaluation, and post-finishing technique. • Material design curves: Room and elevated temperature tensiles, low cycle fatigue, and creep rupture properties curves generated. • AM specifications: Key metal powder characteristics, laser parameters, and heat-treatment controls identified.« less

Self-Adaptive Stepsize Search Applied to Optimal Structural Design

NASA Astrophysics Data System (ADS)

Nolle, L.; Bland, J. A.

Structural engineering often involves the design of space frames that are required to resist predefined external forces without exhibiting plastic deformation. The weight of the structure and hence the weight of its constituent members has to be as low as possible for economical reasons without violating any of the load constraints. Design spaces are usually vast and the computational costs for analyzing a single design are usually high. Therefore, not every possible design can be evaluated for real-world problems. In this work, a standard structural design problem, the 25-bar problem, has been solved using self-adaptive stepsize search (SASS), a relatively new search heuristic. This algorithm has only one control parameter and therefore overcomes the drawback of modern search heuristics, i.e. the need to first find a set of optimum control parameter settings for the problem at hand. In this work, SASS outperforms simulated-annealing, genetic algorithms, tabu search and ant colony optimization.

Using prediction uncertainty analysis to design hydrologic monitoring networks: Example applications from the Great Lakes water availability pilot project

USGS Publications Warehouse

Fienen, Michael N.; Doherty, John E.; Hunt, Randall J.; Reeves, Howard W.

2010-01-01

The importance of monitoring networks for resource-management decisions is becoming more recognized, in both theory and application. Quantitative computer models provide a science-based framework to evaluate the efficacy and efficiency of existing and possible future monitoring networks. In the study described herein, two suites of tools were used to evaluate the worth of new data for specific predictions, which in turn can support efficient use of resources needed to construct a monitoring network. The approach evaluates the uncertainty of a model prediction and, by using linear propagation of uncertainty, estimates how much uncertainty could be reduced if the model were calibrated with addition information (increased a priori knowledge of parameter values or new observations). The theoretical underpinnings of the two suites of tools addressing this technique are compared, and their application to a hypothetical model based on a local model inset into the Great Lakes Water Availability Pilot model are described. Results show that meaningful guidance for monitoring network design can be obtained by using the methods explored. The validity of this guidance depends substantially on the parameterization as well; hence, parameterization must be considered not only when designing the parameter-estimation paradigm but also-importantly-when designing the prediction-uncertainty paradigm.

Fast and Accurate Circuit Design Automation through Hierarchical Model Switching.

PubMed

Huynh, Linh; Tagkopoulos, Ilias

2015-08-21

In computer-aided biological design, the trifecta of characterized part libraries, accurate models and optimal design parameters is crucial for producing reliable designs. As the number of parts and model complexity increase, however, it becomes exponentially more difficult for any optimization method to search the solution space, hence creating a trade-off that hampers efficient design. To address this issue, we present a hierarchical computer-aided design architecture that uses a two-step approach for biological design. First, a simple model of low computational complexity is used to predict circuit behavior and assess candidate circuit branches through branch-and-bound methods. Then, a complex, nonlinear circuit model is used for a fine-grained search of the reduced solution space, thus achieving more accurate results. Evaluation with a benchmark of 11 circuits and a library of 102 experimental designs with known characterization parameters demonstrates a speed-up of 3 orders of magnitude when compared to other design methods that provide optimality guarantees.

Reliability Based Geometric Design of Horizontal Circular Curves

NASA Astrophysics Data System (ADS)

Rajbongshi, Pabitra; Kalita, Kuldeep

2018-06-01

Geometric design of horizontal circular curve primarily involves with radius of the curve and stopping sight distance at the curve section. Minimum radius is decided based on lateral thrust exerted on the vehicles and the minimum stopping sight distance is provided to maintain the safety in longitudinal direction of vehicles. Available sight distance at site can be regulated by changing the radius and middle ordinate at the curve section. Both radius and sight distance depend on design speed. Speed of vehicles at any road section is a variable parameter and therefore, normally the 98th percentile speed is taken as the design speed. This work presents a probabilistic approach for evaluating stopping sight distance, considering the variability of all input parameters of sight distance. It is observed that the 98th percentile sight distance value is much lower than the sight distance corresponding to 98th percentile speed. The distribution of sight distance parameter is also studied and found to follow a lognormal distribution. Finally, the reliability based design charts are presented for both plain and hill regions, and considering the effect of lateral thrust.

A study in cost analysis of aggregate production as depending on drilling and blasting design

NASA Astrophysics Data System (ADS)

Bilim, Niyazi; Çelik, Arif; Kekeç, Bilgehan

2017-10-01

Since aggregate production has vital importance for many engineering projects-such as construction, highway and plant-mixed concrete production-this study was undertaken to determine how the costs for such production are affected by the design of drilling and blasting processes used. Aggregates are used in the production of concrete and asphalt, which are critical resources for the construction sector. The ongoing population increase and the growth of living standards around the world drive the increasing demand for these products. As demand grows, competition has naturally arisen among producers in the industry. Competition in the market has directly affected prices, which leads to the need for new measures and cost analysis on production costs. The cost calculation is one of the most important parameters in mining activities. Aggregate production operations include drilling, blasting, secondary crushing (if necessary), loading, hauling and crushing-screening, and each of these factors affects cost. In this study, drilling and blasting design parameters (such as hole diameter, hole depth, hole distance and burden) were investigated and evaluated for their effect on the total cost of quarrying these products, based on a particular quarry selected for this research. As the result of evaluation, the parameters actually driving costs have been identified, and their effects on the cost have been determined. In addition, some suggestions are presented regarding production design which may lead to avoiding increased production costs.

A critical evaluation of the experimental design of studies of mechanism based enzyme inhibition, with implications for in vitro-in vivo extrapolation.

PubMed

Ghanbari, F; Rowland-Yeo, K; Bloomer, J C; Clarke, S E; Lennard, M S; Tucker, G T; Rostami-Hodjegan, A

2006-04-01

The published literature on mechanism based inhibition (MBI) of CYPs was evaluated with respect to experimental design, methodology and data analysis. Significant variation was apparent in the dilution factor, ratio of preincubation to incubation times and probe substrate concentrations used, and there were some anomalies in the estimation of associated kinetic parameters (k(inact), K(I), r). The impact of the application of inaccurate values of k(inact) and K(I) when extrapolating to the extent of inhibition in vivo is likely to be greatest for those compounds of intermediate inhibitory potency, but this also depends on the fraction of the net clearance of substrate subject to MBI and the pre-systemic and systemic exposure to the inhibitor. For potent inhibitors, the experimental procedure is unlikely to have a material influence on the maximum inhibition. Nevertheless, the bias in the values of the kinetic parameters may influence the time for recovery of enzyme activity following re-synthesis of the enzyme. Careful attention to the design of in vitro experiments to obtain accurate kinetic parameters is necessary for a reliable prediction of different aspects of the in vivo consequences of MBI. The review calls for experimental studies to quantify the impact of study design in studies of MBI, with a view to better harmonisation of protocols.

Calculation of Weibull strength parameters and Batdorf flow-density constants for volume- and surface-flaw-induced fracture in ceramics

NASA Technical Reports Server (NTRS)

Shantaram, S. Pai; Gyekenyesi, John P.

1989-01-01

The calculation of shape and scale parametes of the two-parameter Weibull distribution is described using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. Detailed procedures are given for evaluating 90 percent confidence intervals for maximum likelihood estimates of shape and scale parameters, the unbiased estimates of the shape parameters, and the Weibull mean values and corresponding standard deviations. Furthermore, the necessary steps are described for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull distribution. It also shows how to calculate the Batdorf flaw-density constants by using the Weibull distribution statistical parameters. The techniques described were verified with several example problems, from the open literature, and were coded in the Structural Ceramics Analysis and Reliability Evaluation (SCARE) design program.

Handling Qualities Evaluations of Low Complexity Model Reference Adaptive Controllers for Reduced Pitch and Roll Damping Scenarios

NASA Technical Reports Server (NTRS)

Hanson, Curt; Schaefer, Jacob; Burken, John J.; Johnson, Marcus; Nguyen, Nhan

2011-01-01

National Aeronautics and Space Administration (NASA) researchers have conducted a series of flight experiments designed to study the effects of varying levels of adaptive controller complexity on the performance and handling qualities of an aircraft under various simulated failure or damage conditions. A baseline, nonlinear dynamic inversion controller was augmented with three variations of a model reference adaptive control design. The simplest design consisted of a single adaptive parameter in each of the pitch and roll axes computed using a basic gradient-based update law. A second design was built upon the first by increasing the complexity of the update law. The third and most complex design added an additional adaptive parameter to each axis. Flight tests were conducted using NASA s Full-scale Advanced Systems Testbed, a highly modified F-18 aircraft that contains a research flight control system capable of housing advanced flight controls experiments. Each controller was evaluated against a suite of simulated failures and damage ranging from destabilization of the pitch and roll axes to significant coupling between the axes. Two pilots evaluated the three adaptive controllers as well as the non-adaptive baseline controller in a variety of dynamic maneuvers and precision flying tasks designed to uncover potential deficiencies in the handling qualities of the aircraft, and adverse interactions between the pilot and the adaptive controllers. The work was completed as part of the Integrated Resilient Aircraft Control Project under NASA s Aviation Safety Program.

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

NASA Astrophysics Data System (ADS)

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

2017-01-01

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

Statistical optimization of process parameters for the production of tannase by Aspergillus flavus under submerged fermentation.

PubMed

Mohan, S K; Viruthagiri, T; Arunkumar, C

2014-04-01

Production of tannase by Aspergillus flavus (MTCC 3783) using tamarind seed powder as substrate was studied in submerged fermentation. Plackett-Burman design was applied for the screening of 12 medium nutrients. From the results, the significant nutrients were identified as tannic acid, magnesium sulfate, ferrous sulfate and ammonium sulfate. Further the optimization of process parameters was carried out using response surface methodology (RSM). RSM has been applied for designing of experiments to evaluate the interactive effects through a full 31 factorial design. The optimum conditions were tannic acid concentration, 3.22 %; fermentation period, 96 h; temperature, 35.1 °C; and pH 5.4. Higher value of the regression coefficient (R 2  = 0.9638) indicates excellent evaluation of experimental data by second-order polynomial regression model. The RSM revealed that a maximum tannase production of 139.3 U/ml was obtained at the optimum conditions.

Table look-up estimation of signal and noise parameters from quantized observables

NASA Technical Reports Server (NTRS)

Vilnrotter, V. A.; Rodemich, E. R.

1986-01-01

A table look-up algorithm for estimating underlying signal and noise parameters from quantized observables is examined. A general mathematical model is developed, and a look-up table designed specifically for estimating parameters from four-bit quantized data is described. Estimator performance is evaluated both analytically and by means of numerical simulation, and an example is provided to illustrate the use of the look-up table for estimating signal-to-noise ratios commonly encountered in Voyager-type data.

Aerospace Power Systems Design and Analysis (APSDA) Tool

NASA Technical Reports Server (NTRS)

Truong, Long V.

1998-01-01

The conceptual design of space and/or planetary electrical power systems has required considerable effort. Traditionally, in the early stages of the design cycle (conceptual design), the researchers have had to thoroughly study and analyze tradeoffs between system components, hardware architectures, and operating parameters (such as frequencies) to optimize system mass, efficiency, reliability, and cost. This process could take anywhere from several months to several years (as for the former Space Station Freedom), depending on the scale of the system. Although there are many sophisticated commercial software design tools for personal computers (PC's), none of them can support or provide total system design. To meet this need, researchers at the NASA Lewis Research Center cooperated with Professor George Kusic from the University of Pittsburgh to develop a new tool to help project managers and design engineers choose the best system parameters as quickly as possible in the early design stages (in days instead of months). It is called the Aerospace Power Systems Design and Analysis (APSDA) Tool. By using this tool, users can obtain desirable system design and operating parameters such as system weight, electrical distribution efficiency, bus power, and electrical load schedule. With APSDA, a large-scale specific power system was designed in a matter of days. It is an excellent tool to help designers make tradeoffs between system components, hardware architectures, and operation parameters in the early stages of the design cycle. user interface. It operates on any PC running the MS-DOS (Microsoft Corp.) operating system, version 5.0 or later. A color monitor (EGA or VGA) and two-button mouse are required. The APSDA tool was presented at the 30th Intersociety Energy Conversion Engineering Conference (IECEC) and is being beta tested at several NASA centers. Beta test packages are available for evaluation by contacting the author.

Apodized Pupil Lyot Coronagraphs designs for future segmented space telescopes

NASA Astrophysics Data System (ADS)

St. Laurent, Kathryn; Fogarty, Kevin; Zimmerman, Neil; N’Diaye, Mamadou; Stark, Chris; Sivaramakrishnan, Anand; Pueyo, Laurent; Vanderbei, Robert; Soummer, Remi

2018-01-01

A coronagraphic starlight suppression system situated on a future flagship space observatory offers a promising avenue to image Earth-like exoplanets and search for biomarkers in their atmospheric spectra. One NASA mission concept that could serve as the platform to realize this scientific breakthrough is the Large UV/Optical/IR Surveyor (LUVOIR). Such a mission would also address a broad range of topics in astrophysics with a multi-wavelength suite of instruments.In support of the community’s assessment of the scientific capability of a LUVOIR mission, the Exoplanet Exploration Program (ExEP) has launched a multi-team technical study: Segmented Coronagraph Design and Analysis (SCDA). The goal of this study is to develop viable coronagraph instrument concepts for a LUVOIR-type mission. Results of the SCDA effort will directly inform the mission concept evaluation being carried out by the LUVOIR Science and Technology Definition Team. The apodized pupil Lyot coronagraph (APLC) is one of several coronagraph design families that the SCDA study is assessing. The APLC is a Lyot-style coronagraph that suppresses starlight through a series of amplitude operations on the on-axis field. Given a suite of seven plausible segmented telescope apertures, we have developed an object-oriented software toolkit to automate the exploration of thousands of APLC design parameter combinations. In the course of exploring this parameter space we have established relationships between APLC throughput and telescope aperture geometry, Lyot stop, inner working angle, bandwidth, and contrast level. In parallel with the parameter space exploration, we have investigated several strategies to improve the robustness of APLC designs to fabrication and alignment errors and integrated a Design Reference Mission framework to evaluate designs with scientific yield metrics.

Analysis of the passive stabilization of the long duration exposure facility

NASA Technical Reports Server (NTRS)

Siegel, S. H.; Vishwanath, N. S.

1977-01-01

The nominal Long Duration Exposure Facility (LDEF) configurations and the anticipated orbit parameters are presented. A linear steady state analysis was performed using these parameters. The effects of orbit eccentricity, solar pressure, aerodynamic pressure, magnetic dipole, and the magnetically anchored rate damper were evaluated to determine the configuration sensitivity to variations in these parameters. The worst case conditions for steady state errors were identified, and the performance capability calculated. Garber instability bounds were evaluated for the range of configuration and damping coefficients under consideration. The transient damping capabilities of the damper were examined, and the time constant as a function of damping coefficient and spacecraft moment of inertia determined. The capture capabilities of the damper were calculated, and the results combined with steady state, transient, and Garber instability analyses to select damper design parameters.

Earth orbital teleoperator visual system evaluation program

NASA Technical Reports Server (NTRS)

Shields, N. L., Jr.; Kirkpatrick, M., III; Frederick, P. N.; Malone, T. B.

1975-01-01

Empirical tests of range estimation accuracy and resolution, via television, under monoptic and steroptic viewing conditions are discussed. Test data are used to derive man machine interface requirements and make design decisions for an orbital remote manipulator system. Remote manipulator system visual tasks are given and the effects of system parameters of these tasks are evaluated.

Nuclear Electric Vehicle Optimization Toolset (NEVOT)

NASA Technical Reports Server (NTRS)

Tinker, Michael L.; Steincamp, James W.; Stewart, Eric T.; Patton, Bruce W.; Pannell, William P.; Newby, Ronald L.; Coffman, Mark E.; Kos, Larry D.; Qualls, A. Lou; Greene, Sherrell

2004-01-01

The Nuclear Electric Vehicle Optimization Toolset (NEVOT) optimizes the design of all major nuclear electric propulsion (NEP) vehicle subsystems for a defined mission within constraints and optimization parameters chosen by a user. The tool uses a genetic algorithm (GA) search technique to combine subsystem designs and evaluate the fitness of the integrated design to fulfill a mission. The fitness of an individual is used within the GA to determine its probability of survival through successive generations in which the designs with low fitness are eliminated and replaced with combinations or mutations of designs with higher fitness. The program can find optimal solutions for different sets of fitness metrics without modification and can create and evaluate vehicle designs that might never be considered through traditional design techniques. It is anticipated that the flexible optimization methodology will expand present knowledge of the design trade-offs inherent in designing nuclear powered space vehicles and lead to improved NEP designs.

Economic evaluation of flying-qualities design criteria for a transport configured with relaxed static stability

NASA Technical Reports Server (NTRS)

Sliwa, S. M.

1980-01-01

Direct constrained parameter optimization was used to optimally size a medium range transport for minimum direct operating cost. Several stability and control constraints were varied to study the sensitivity of the configuration to specifying the unaugmented flying qualities of transports designed to take maximum advantage of relaxed static stability augmentation systems. Additionally, a number of handling qualities related design constants were studied with respect to their impact on the design.

Predictive design and interpretation of colliding pulse injected laser wakefield experiments

NASA Astrophysics Data System (ADS)

Cormier-Michel, Estelle; Ranjbar, Vahid H.; Cowan, Ben M.; Bruhwiler, David L.; Geddes, Cameron G. R.; Chen, Min; Ribera, Benjamin; Esarey, Eric; Schroeder, Carl B.; Leemans, Wim P.

2010-11-01

The use of colliding laser pulses to control the injection of plasma electrons into the plasma wake of a laser plasma accelerator is a promising approach to obtaining stable, tunable electron bunches with reduced emittance and energy spread. Colliding Pulse Injection (CPI) experiments are being performed by groups around the world. We will present recent particle-in-cell simulations, using the parallel VORPAL framework, of CPI for physical parameters relevant to ongoing experiments of the LOASIS program at LBNL. We evaluate the effect of laser and plasma tuning, on the trapped electron bunch and perform parameter scans in order to optimize the quality of the bunch. Impact of non-ideal effects such as imperfect laser modes and laser self focusing are also evaluated. Simulation data are validated against current experimental results, and are used to design future experiments.

Evaluation of Laminar Flow Control System Concepts for Subsonic Commercial Transport Aircraft

NASA Technical Reports Server (NTRS)

Sturgeon, R. F.

1980-01-01

Alternatives in the design of laminar flow control (LFC) subsonic commerical transport aircraft for opeation in the 1980's period were studied. Analyses were conducted to select mission parameters and define optimum aircraft configurational parameters for the selected mission, defined by a passenger payload of 400 and a design range of 12, 038 km (6500 n mi). The baseline aircraft developed for this mission was used as a vehicle for the evaluation and development of alternative LFC system concepts. Alternatices in the areas of aerodynamics, structures and materials, LFC systems, leading-edge region cleaning, and integration of auxiliary systems were studied. Relative to a similarly-optimized advanced technology turbulent transport, the final LFC configuration is approximately equal in DOC but provides descreases of 8.2% in gross weight and 21.7% in fuel consumption.

Optimum Design of Forging Process Parameters and Preform Shape under Uncertainties

NASA Astrophysics Data System (ADS)

Repalle, Jalaja; Grandhi, Ramana V.

2004-06-01

Forging is a highly complex non-linear process that is vulnerable to various uncertainties, such as variations in billet geometry, die temperature, material properties, workpiece and forging equipment positional errors and process parameters. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion and production risk. Identifying the sources of uncertainties, quantifying and controlling them will reduce risk in the manufacturing environment, which will minimize the overall cost of production. In this paper, various uncertainties that affect forging tool life and preform design are identified, and their cumulative effect on the forging process is evaluated. Since the forging process simulation is computationally intensive, the response surface approach is used to reduce time by establishing a relationship between the system performance and the critical process design parameters. Variability in system performance due to randomness in the parameters is computed by applying Monte Carlo Simulations (MCS) on generated Response Surface Models (RSM). Finally, a Robust Methodology is developed to optimize forging process parameters and preform shape. The developed method is demonstrated by applying it to an axisymmetric H-cross section disk forging to improve the product quality and robustness.

Parametric entry corridors for lunar/Mars aerocapture missions

NASA Technical Reports Server (NTRS)

Ling, Lisa M.; Baseggio, Franco M.; Fuhry, Douglas P.

1991-01-01

Parametric atmospheric entry corridor data are presented for Earth and Mars aerocapture. Parameter ranges were dictated by the range of mission designs currently envisioned as possibilities for the Human Exploration Initiative (HEI). This data, while not providing a means for exhaustive evaluation of aerocapture performance, should prove to be a useful aid for preliminary mission design and evaluation. Entry corridors are expressed as ranges of allowable vacuum periapse altitude of the planetary approach hyperbolic orbit, with chart provided for conversion to an approximate flight path angle corridor at entry interface (125 km altitude). The corridor boundaries are defined by open-loop aerocapture trajectories which satisfy boundary constraints while utilizing the full aerodynamic control capability of the vehicle (i.e., full lift-up or full lift-down). Parameters examined were limited to those of greatest importance from an aerocapture performance standpoint, including the approach orbit hyperbolic excess velocity, the vehicle lift to drag ratio, maximum aerodynamic load factor limit, and the apoapse of the target orbit. The impact of the atmospheric density bias uncertainties are also included. The corridor data is presented in graphical format, and examples of the utilization of these graphs for mission design and evaluation are included.

Optimization of Primary Drying in Lyophilization during Early Phase Drug Development using a Definitive Screening Design with Formulation and Process Factors.

PubMed

Goldman, Johnathan M; More, Haresh T; Yee, Olga; Borgeson, Elizabeth; Remy, Brenda; Rowe, Jasmine; Sadineni, Vikram

2018-06-08

Development of optimal drug product lyophilization cycles is typically accomplished via multiple engineering runs to determine appropriate process parameters. These runs require significant time and product investments, which are especially costly during early phase development when the drug product formulation and lyophilization process are often defined simultaneously. Even small changes in the formulation may require a new set of engineering runs to define lyophilization process parameters. In order to overcome these development difficulties, an eight factor definitive screening design (DSD), including both formulation and process parameters, was executed on a fully human monoclonal antibody (mAb) drug product. The DSD enables evaluation of several interdependent factors to define critical parameters that affect primary drying time and product temperature. From these parameters, a lyophilization development model is defined where near optimal process parameters can be derived for many different drug product formulations. This concept is demonstrated on a mAb drug product where statistically predicted cycle responses agree well with those measured experimentally. This design of experiments (DoE) approach for early phase lyophilization cycle development offers a workflow that significantly decreases the development time of clinically and potentially commercially viable lyophilization cycles for a platform formulation that still has variable range of compositions. Copyright © 2018. Published by Elsevier Inc.

A risk-based approach to management of leachables utilizing statistical analysis of extractables.

PubMed

Stults, Cheryl L M; Mikl, Jaromir; Whelehan, Oliver; Morrical, Bradley; Duffield, William; Nagao, Lee M

2015-04-01

To incorporate quality by design concepts into the management of leachables, an emphasis is often put on understanding the extractable profile for the materials of construction for manufacturing disposables, container-closure, or delivery systems. Component manufacturing processes may also impact the extractable profile. An approach was developed to (1) identify critical components that may be sources of leachables, (2) enable an understanding of manufacturing process factors that affect extractable profiles, (3) determine if quantitative models can be developed that predict the effect of those key factors, and (4) evaluate the practical impact of the key factors on the product. A risk evaluation for an inhalation product identified injection molding as a key process. Designed experiments were performed to evaluate the impact of molding process parameters on the extractable profile from an ABS inhaler component. Statistical analysis of the resulting GC chromatographic profiles identified processing factors that were correlated with peak levels in the extractable profiles. The combination of statistically significant molding process parameters was different for different types of extractable compounds. ANOVA models were used to obtain optimal process settings and predict extractable levels for a selected number of compounds. The proposed paradigm may be applied to evaluate the impact of material composition and processing parameters on extractable profiles and utilized to manage product leachables early in the development process and throughout the product lifecycle.

Formulation and evaluation of buccal patches for delivery of atenolol.

PubMed

Adhikari, Surya N Ratha; Nayak, Bhabani S; Nayak, Amit K; Mohanty, Biswaranjan

2010-09-01

Buccal patches for the delivery of atenolol using sodium alginate with various hydrophilic polymers like carbopol 934 P, sodium carboxymethyl cellulose, and hydroxypropyl methylcellulose in various proportions and combinations were fabricated by solvent casting technique. Various physicomechanical parameters like weight variation, thickness, folding endurance, drug content, moisture content, moisture absorption, and various ex vivo mucoadhesion parameters like mucoadhesive strength, force of adhesion, and bond strength were evaluated. An in vitro drug release study was designed, and it was carried out using commercial semipermeable membrane. All these fabricated patches were sustained for 24 h and obeyed first-order release kinetics. Ex vivo drug permeation study was also performed using porcine buccal mucosa, and various drug permeation parameters like flux and lag time were determined.

A pseudo-noise transponder design for low data rate users of the tracking and data relay satellite system

NASA Technical Reports Server (NTRS)

Birch, J. N.

1971-01-01

A compromise optimum design for the low data rate users of the Tracking and Data Relay Satellite System (TDRSS) is presented. Design goals for the TDRSS are employed in this report to arrive at the transponder design. Multipath, R.F.I., antenna pattern anomolies, other user signals, and other definable degrading factors are included as trade-off parameters in the design. Synchronization, emergency voice, user stabilization, polarization diversity and error control coding are also considered and their impact on the transponder design is evaluated.

Auditorium acoustics evaluation based on simulated impulse response

NASA Astrophysics Data System (ADS)

Wu, Shuoxian; Wang, Hongwei; Zhao, Yuezhe

2004-05-01

The impulse responses and other acoustical parameters of Huangpu Teenager Palace in Guangzhou were measured. Meanwhile, the acoustical simulation and auralization based on software ODEON were also made. The comparison between the parameters based on computer simulation and measuring is given. This case study shows that auralization technique based on computer simulation can be used for predicting the acoustical quality of a hall at its design stage.

Design of a Computer-Controlled, Random-Access Slide Projector Interface. Final Report (April 1974 - November 1974).

ERIC Educational Resources Information Center

Kirby, Paul J.; And Others

The design, development, test, and evaluation of an electronic hardware device interfacing a commercially available slide projector with a plasma panel computer terminal is reported. The interface device allows an instructional computer program to select slides for viewing based upon the lesson student situation parameters of the instructional…

Planning and evaluation parameters for offshore complexes

NASA Technical Reports Server (NTRS)

Sincoff, M. Z. (Editor); Dajani, J. S. (Editor)

1976-01-01

Issues are presented for consideration in the planning and design of offshore artificial complexes. The construction of such complexes, their social, economic, and ecological impacts, and the legal-political-institutional environments within which their development could occur, are discussed. Planning, design, and construction of near-shore complexes located off the Mid-Atlantic coast of the United States is emphasized.

Applicability of Monte-Carlo Simulation to Equipment Design of Radioactive Noble Gas Monitor

NASA Astrophysics Data System (ADS)

Sakai, Hirotaka; Hattori, Kanako; Umemura, Norihiro

In the nuclear facilities, radioactive noble gas is continuously monitored by using the radioactive noble gas monitor with beta-sensitive plastic scintillation radiation detector. The detection efficiency of the monitor is generally calibrated by using a calibration loop and standard radioactive noble gases such as 85Kr. In this study, the applicability of PHITS to the equipment design of the radioactive noble gas monitor was evaluated by comparing the calculated results to the test results obtained by actual calibration loop tests to simplify the radiation monitor design evaluation. It was confirmed that the calculated results were well matched to the test results of the monitor after the modeling. In addition, the key parameters for equipment design, such as thickness of detector window or depth of the sampler, were also specified and evaluated.

Integration of Energy Consumption and CO2 Emissions into the DES Tool with Lean Thinking

NASA Astrophysics Data System (ADS)

Nujoom, Reda; Wang, Qian

2018-01-01

Products are often made by accomplishing a number of manufacturing processes on a sequential flow line which is also known as manufacturing systems. In a traditional way, design or evaluation of a manufacturing system involves a determination or an analysis of the system performance by adjusting system parameters relating to such as system capacity, material processing time, material-handling and transportation and shop-floor layout. Environment related parameters, however, are not considered or considered as separate issues. In the past decade, there has been a growing concern about the environmental protection and governments almost in all over the world enforced certain rules and regulation to promote energy saving and reduce carbon dioxide (CO2) emissions in manufacturing industry. To date, development of a sustainable manufacturing system requires designers who need not merely to apply traditional methods of improving system efficiency and productivity but also examine the environmental issues in production of the developed manufacturing system. Most researchers, however, focused on operational systems, which do not incorporate the effect of environmental factors that may also affect the system performance. This paper presents a research work aiming to addresses these issues in design and evaluation of sustainable manufacturing systems incorporating parameters of energy consumption and CO2 emissions into a DES (discrete event simulation) tool.

Investigation into Improvement for Anti-Rollover Propensity of SUV

NASA Astrophysics Data System (ADS)

Xiong, Fei; Lan, Fengchong; Chen, Jiqing; Yang, Yuedong

2017-05-01

Currently, many research from domestic and foreign on improving anti-rollover performance of vehicle mainly focus on the electronic control of auxiliary equipment, do not make full use of suspension layout to optimize anti-rollover performance of vehicle. This investigation into anti-rollover propensity improvement concentrates on the vehicle parameters greatly influencing on anti-rollover propensity of vehicle. A simulation based on fishhook procedure is used to perform design trials and evaluations aimed at ensuring an optimal balance between vehicle's design parameters and various engineering capacities, the anti-rollover propensity is optimized at the detailed design stage of a new SUV model. Firstly a four-DOF theoretical kinematic model is established, then a complete multi-body dynamics model built in ADAMS/car based on the whole vehicle parameters is correlated to the objective handing and stability test results of a mule car. Secondly, in fishhook test simulations, the Design of Experiments method is used to quantify the effect of the vehicle parameters on the anti-rollover performance. By means of the simulation, the roll center height of front suspension should be more than 30 mm, that of rear suspension less than 150 mm, and the HCG less than 620 mm for the SUV. The ratio of front to rear suspension roll stiffness should be ranged from 1.4 to 1.6 for the SUV. As a result, at the detailed design stage of product, the anti-rollover performance of vehicle can be improved by optimizing chassis and integrated vehicle parameters.

A reliable algorithm for optimal control synthesis

NASA Technical Reports Server (NTRS)

Vansteenwyk, Brett; Ly, Uy-Loi

1992-01-01

In recent years, powerful design tools for linear time-invariant multivariable control systems have been developed based on direct parameter optimization. In this report, an algorithm for reliable optimal control synthesis using parameter optimization is presented. Specifically, a robust numerical algorithm is developed for the evaluation of the H(sup 2)-like cost functional and its gradients with respect to the controller design parameters. The method is specifically designed to handle defective degenerate systems and is based on the well-known Pade series approximation of the matrix exponential. Numerical test problems in control synthesis for simple mechanical systems and for a flexible structure with densely packed modes illustrate positively the reliability of this method when compared to a method based on diagonalization. Several types of cost functions have been considered: a cost function for robust control consisting of a linear combination of quadratic objectives for deterministic and random disturbances, and one representing an upper bound on the quadratic objective for worst case initial conditions. Finally, a framework for multivariable control synthesis has been developed combining the concept of closed-loop transfer recovery with numerical parameter optimization. The procedure enables designers to synthesize not only observer-based controllers but also controllers of arbitrary order and structure. Numerical design solutions rely heavily on the robust algorithm due to the high order of the synthesis model and the presence of near-overlapping modes. The design approach is successfully applied to the design of a high-bandwidth control system for a rotorcraft.

Advanced rotorcraft control using parameter optimization

NASA Technical Reports Server (NTRS)

Vansteenwyk, Brett; Ly, Uy-Loi

1991-01-01

A reliable algorithm for the evaluation of a quadratic performance index and its gradients with respect to the controller design parameters is presented. The algorithm is part of a design algorithm for an optimal linear dynamic output feedback controller that minimizes a finite time quadratic performance index. The numerical scheme is particularly robust when it is applied to the control law synthesis for systems with densely packed modes and where there is a high likelihood of encountering degeneracies in the closed loop eigensystem. This approach through the use of a accurate Pade series approximation does not require the closed loop system matrix to be diagonalizable. The algorithm has been included in a control design package for optimal robust low order controllers. Usefulness of the proposed numerical algorithm has been demonstrated using numerous practical design cases where degeneracies occur frequently in the closed loop system under an arbitrary controller design initialization and during the numerical search.

Design and analysis of multilayer x ray/XUV microscope

NASA Technical Reports Server (NTRS)

Shealy, David L.

1990-01-01

The design and analysis of a large number of normal incidence multilayer x ray microscopes based on the spherical mirror Schwarzschild configuration is examined. Design equations for the spherical mirror Schwarzschild microscopes are summarized and used to evaluate mirror parameters for microscopes with magnifications ranging from 2 to 50x. Ray tracing and diffraction analyses are carried out for many microscope configurations to determine image resolution as a function of system parameters. The results are summarized in three publication included herein. A preliminary study of advanced reflecting microscope configurations, where aspherics are used in place of the spherical microscope mirror elements, has indicated that the aspherical elements will improve off-axis image resolution and increase the effective field of view.

Parametric system identification of catamaran for improving controller design

NASA Astrophysics Data System (ADS)

Timpitak, Surasak; Prempraneerach, Pradya; Pengwang, Eakkachai

2018-01-01

This paper presents an estimation of simplified dynamic model for only surge- and yaw- motions of catamaran by using system identification (SI) techniques to determine associated unknown parameters. These methods will enhance the performance of designing processes for the motion control system of Unmanned Surface Vehicle (USV). The simulation results demonstrate an effective way to solve for damping forces and to determine added masses by applying least-square and AutoRegressive Exogenous (ARX) methods. Both methods are then evaluated according to estimated parametric errors from the vehicle’s dynamic model. The ARX method, which yields better estimated accuracy, can then be applied to identify unknown parameters as well as to help improving a controller design of a real unmanned catamaran.

An information theoretic approach to use high-fidelity codes to calibrate low-fidelity codes

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

Lewis, Allison, E-mail: lewis.allison10@gmail.com; Smith, Ralph; Williams, Brian

For many simulation models, it can be prohibitively expensive or physically infeasible to obtain a complete set of experimental data to calibrate model parameters. In such cases, one can alternatively employ validated higher-fidelity codes to generate simulated data, which can be used to calibrate the lower-fidelity code. In this paper, we employ an information-theoretic framework to determine the reduction in parameter uncertainty that is obtained by evaluating the high-fidelity code at a specific set of design conditions. These conditions are chosen sequentially, based on the amount of information that they contribute to the low-fidelity model parameters. The goal is tomore » employ Bayesian experimental design techniques to minimize the number of high-fidelity code evaluations required to accurately calibrate the low-fidelity model. We illustrate the performance of this framework using heat and diffusion examples, a 1-D kinetic neutron diffusion equation, and a particle transport model, and include initial results from the integration of the high-fidelity thermal-hydraulics code Hydra-TH with a low-fidelity exponential model for the friction correlation factor.« less

Revisiting Coiled Flocculator Performance for Particle Aggregation.

PubMed

2017-09-08

This work summarizes recent studies evaluating the torsion and curvature parameters in the flocculation efficiency using a hydraulic plug-flow flocculator named as Flocs Generator Reactor (FGR). Colloidal Fe(OH)3 and coal particles were used as suspension models and a cationic polyacrylamide was used for the flocculation. The effectiveness of the aggregation process (in the distinct curvature and torsion parameters and hydrodynamic conditions) was evaluated by the settling rate of the Fe(OH)3 flocs and flocs size by photographic analysis. Due to curvature, a secondary flow is induced and the profiles of the flow quantities differ from those for a straight pipe. Results showed that the difference in the flocculator design influences the Fe(OH)3 flocs size and settling rates, reaching values about 13 and 4 mh-1, for the coiled and straight pipes respectively. Coal flocs generation also showed to be dependent on the flocculator design and shear rate. Results showed that turbulent kinetic energy increases due to curvature when the torsion parameter is kept constant (pitch close to zero) enhancing the flocs formation.

Application of a Constant Gain Extended Kalman Filter for In-Flight Estimation of Aircraft Engine Performance Parameters

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.; Litt, Jonathan S.

2005-01-01

An approach based on the Constant Gain Extended Kalman Filter (CGEKF) technique is investigated for the in-flight estimation of non-measurable performance parameters of aircraft engines. Performance parameters, such as thrust and stall margins, provide crucial information for operating an aircraft engine in a safe and efficient manner, but they cannot be directly measured during flight. A technique to accurately estimate these parameters is, therefore, essential for further enhancement of engine operation. In this paper, a CGEKF is developed by combining an on-board engine model and a single Kalman gain matrix. In order to make the on-board engine model adaptive to the real engine s performance variations due to degradation or anomalies, the CGEKF is designed with the ability to adjust its performance through the adjustment of artificial parameters called tuning parameters. With this design approach, the CGEKF can maintain accurate estimation performance when it is applied to aircraft engines at offnominal conditions. The performance of the CGEKF is evaluated in a simulation environment using numerous component degradation and fault scenarios at multiple operating conditions.

Fracture mechanics concepts in reliability analysis of monolithic ceramics

NASA Technical Reports Server (NTRS)

Manderscheid, Jane M.; Gyekenyesi, John P.

1987-01-01

Basic design concepts for high-performance, monolithic ceramic structural components are addressed. The design of brittle ceramics differs from that of ductile metals because of the inability of ceramic materials to redistribute high local stresses caused by inherent flaws. Random flaw size and orientation requires that a probabilistic analysis be performed in order to determine component reliability. The current trend in probabilistic analysis is to combine linear elastic fracture mechanics concepts with the two parameter Weibull distribution function to predict component reliability under multiaxial stress states. Nondestructive evaluation supports this analytical effort by supplying data during verification testing. It can also help to determine statistical parameters which describe the material strength variation, in particular the material threshold strength (the third Weibull parameter), which in the past was often taken as zero for simplicity.

Simulation based evaluation of the designs of the Advanced Gamma-ray Imageing System (AGIS)

NASA Astrophysics Data System (ADS)

Bugaev, Slava; Buckley, James; Digel, Seth; Funk, Stephen; Konopelko, Alex; Krawczynski, Henric; Lebohec, Steohan; Maier, Gernot; Vassiliev, Vladimir

2009-05-01

The AGIS project under design study, is a large array of imaging atmospheric Cherenkov telescopes for gamma-rays astronomy between 40GeV and 100 TeV. In this paper we present the ongoing simulation effort to model the considered design approaches as a function of the main parameters such as array geometry, telescope optics and camera design in such a way the gamma ray observation capabilities can be optimized against the overall project cost.

Absorbable energy monitoring scheme: new design protocol to test vehicle structural crashworthiness.

PubMed

Ofochebe, Sunday M; Enibe, Samuel O; Ozoegwu, Chigbogu G

2016-05-01

In vehicle crashworthiness design optimization detailed system evaluation capable of producing reliable results are basically achieved through high-order numerical computational (HNC) models such as the dynamic finite element model, mesh-free model etc. However the application of these models especially during optimization studies is basically challenged by their inherent high demand on computational resources, conditional stability of the solution process, and lack of knowledge of viable parameter range for detailed optimization studies. The absorbable energy monitoring scheme (AEMS) presented in this paper suggests a new design protocol that attempts to overcome such problems in evaluation of vehicle structure for crashworthiness. The implementation of the AEMS involves studying crash performance of vehicle components at various absorbable energy ratios based on a 2DOF lumped-mass-spring (LMS) vehicle impact model. This allows for prompt prediction of useful parameter values in a given design problem. The application of the classical one-dimensional LMS model in vehicle crash analysis is further improved in the present work by developing a critical load matching criterion which allows for quantitative interpretation of the results of the abstract model in a typical vehicle crash design. The adequacy of the proposed AEMS for preliminary vehicle crashworthiness design is demonstrated in this paper, however its extension to full-scale design-optimization problem involving full vehicle model that shows greater structural detail requires more theoretical development.

An overview of the evaluation plan for PC/MISI: PC-based Multiple Information System Interface

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Lim, Bee Lee; Hall, Philip P.

1985-01-01

An initial evaluation plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intend to be used as a blueprint for the evaluation of this system. Each objective of the design project is discussed along with the evaluation parameters and methodology to be used in the evaluation of the implementation's achievement of those objectives. The potential of the system for research activities related to more general aspects of information retrieval is also discussed.

Conceptual spacecraft systems design and synthesis

NASA Technical Reports Server (NTRS)

Wright, R. L.; Deryder, D. D.; Ferebee, M. J., Jr.

1984-01-01

An interactive systems design and synthesis is performed on future spacecraft concepts using the Interactive Design and Evaluation of Advanced Systems (IDEAS) computer-aided design and analysis system. The capabilities and advantages of the systems-oriented interactive computer-aided design and analysis system are described. The synthesis of both large antenna and space station concepts, and space station evolutionary growth designs is demonstrated. The IDEAS program provides the user with both an interactive graphics and an interactive computing capability which consists of over 40 multidisciplinary synthesis and analysis modules. Thus, the user can create, analyze, and conduct parametric studies and modify earth-orbiting spacecraft designs (space stations, large antennas or platforms, and technologically advanced spacecraft) at an interactive terminal with relative ease. The IDEAS approach is useful during the conceptual design phase of advanced space missions when a multiplicity of parameters and concepts must be analyzed and evaluated in a cost-effective and timely manner.

Virtual parameter-estimation experiments in Bioprocess-Engineering education.

PubMed

Sessink, Olivier D T; Beeftink, Hendrik H; Hartog, Rob J M; Tramper, Johannes

2006-05-01

Cell growth kinetics and reactor concepts constitute essential knowledge for Bioprocess-Engineering students. Traditional learning of these concepts is supported by lectures, tutorials, and practicals: ICT offers opportunities for improvement. A virtual-experiment environment was developed that supports both model-related and experimenting-related learning objectives. Students have to design experiments to estimate model parameters: they choose initial conditions and 'measure' output variables. The results contain experimental error, which is an important constraint for experimental design. Students learn from these results and use the new knowledge to re-design their experiment. Within a couple of hours, students design and run many experiments that would take weeks in reality. Usage was evaluated in two courses with questionnaires and in the final exam. The faculties involved in the two courses are convinced that the experiment environment supports essential learning objectives well.

Coupled parametric design of flow control and duct shape

NASA Technical Reports Server (NTRS)

Florea, Razvan (Inventor); Bertuccioli, Luca (Inventor)

2009-01-01

A method for designing gas turbine engine components using a coupled parametric analysis of part geometry and flow control is disclosed. Included are the steps of parametrically defining the geometry of the duct wall shape, parametrically defining one or more flow control actuators in the duct wall, measuring a plurality of performance parameters or metrics (e.g., flow characteristics) of the duct and comparing the results of the measurement with desired or target parameters, and selecting the optimal duct geometry and flow control for at least a portion of the duct, the selection process including evaluating the plurality of performance metrics in a pareto analysis. The use of this method in the design of inter-turbine transition ducts, serpentine ducts, inlets, diffusers, and similar components provides a design which reduces pressure losses and flow profile distortions.

The Ultrasonic Directional Tidal Breathing Pattern Sensor: Equitable Design Realization Based on Phase Information

PubMed Central

Sinharay, Arijit; Rakshit, Raj; Chakravarty, Tapas; Ghosh, Deb; Pal, Arpan

2017-01-01

Pulmonary ailments are conventionally diagnosed by spirometry. The complex forceful breathing maneuver as well as the extreme cost of spirometry renders it unsuitable in many situations. This work is aimed to facilitate an emerging direction of tidal breathing-based pulmonary evaluation by designing a novel, equitable, precise and portable device for acquisition and analysis of directional tidal breathing patterns, in real time. The proposed system primarily uses an in-house designed blow pipe, 40-kHz air-coupled ultrasound transreceivers, and a radio frequency (RF) phase-gain integrated circuit (IC). Moreover, in order to achieve high sensitivity in a cost-effective design philosophy, we have exploited the phase measurement technique, instead of selecting the contemporary time-of-flight (TOF) measurement; since application of the TOF principle in tidal breathing assessments requires sub-micro to nanosecond time resolution. This approach, which depends on accurate phase measurement, contributed to enhanced sensitivity using a simple electronics design. The developed system has been calibrated using a standard 3-L calibration syringe. The parameters of this system are validated against a standard spirometer, with maximum percentage error below 16%. Further, the extracted respiratory parameters related to tidal breathing have been found to be comparable with relevant prior works. The error in detecting respiration rate only is 3.9% compared to manual evaluation. These encouraging insights reveal the definite potential of our tidal breathing pattern (TBP) prototype for measuring tidal breathing parameters in order to extend the reach of affordable healthcare in rural regions and developing areas. PMID:28800103

Ignitability test method

NASA Technical Reports Server (NTRS)

Bement, Laurence J.; Schimmel, Morry L.

1989-01-01

To overcome serious weaknesses in determining the performance of initiating devices, a novel 'ignitability test method', representing actual design interfaces and ignition materials, has been developed. Ignition device output consists of heat, light, gas an burning particles. Past research methods have evaluated these parameters individually. This paper describes the development and demonstration of an ignitability test method combining all these parameters, and the quantitative assessment of the ignition performance of two widely used percussion primers, the M42C1-PA101 and the M42C2-793. The ignition materials used for this evaluation were several powder, granule and pellet sizes of black powder and boron-potassium nitrate. This test method should be useful for performance evaluation of all initiator types, quality assurance, evaluation of ignition interfaces, and service life studies of initiators and ignition materials.

Quantitative analysis of spatial variability of geotechnical parameters

NASA Astrophysics Data System (ADS)

Fang, Xing

2018-04-01

Geotechnical parameters are the basic parameters of geotechnical engineering design, while the geotechnical parameters have strong regional characteristics. At the same time, the spatial variability of geotechnical parameters has been recognized. It is gradually introduced into the reliability analysis of geotechnical engineering. Based on the statistical theory of geostatistical spatial information, the spatial variability of geotechnical parameters is quantitatively analyzed. At the same time, the evaluation of geotechnical parameters and the correlation coefficient between geotechnical parameters are calculated. A residential district of Tianjin Survey Institute was selected as the research object. There are 68 boreholes in this area and 9 layers of mechanical stratification. The parameters are water content, natural gravity, void ratio, liquid limit, plasticity index, liquidity index, compressibility coefficient, compressive modulus, internal friction angle, cohesion and SP index. According to the principle of statistical correlation, the correlation coefficient of geotechnical parameters is calculated. According to the correlation coefficient, the law of geotechnical parameters is obtained.

Thematic Mapper: Design through flight evaluation

NASA Technical Reports Server (NTRS)

1984-01-01

LANDSAT 4 and 5, launched in 1982 and 1984, not only carried the Thematic Mapper, but were redesigned to handle the increased data rates associated with it, and to communicate that data to Earth via geosynchronous orbiting Tracking and Data Relay Satellites (TDRS). The TM development program is summarized. A brief historical perspective is presented of the evolution of design requirements and hardware development. The basic performance parameters that serve as sensor design guidelines are presented.

Structural similitude and design of scaled down laminated models

NASA Technical Reports Server (NTRS)

Simitses, G. J.; Rezaeepazhand, J.

1993-01-01

The excellent mechanical properties of laminated composite structures make them prime candidates for wide variety of applications in aerospace, mechanical and other branches of engineering. The enormous design flexibility of advanced composites is obtained at the cost of large number of design parameters. Due to complexity of the systems and lack of complete design based informations, designers tend to be conservative in their design. Furthermore, any new design is extensively evaluated experimentally until it achieves the necessary reliability, performance and safety. However, the experimental evaluation of composite structures are costly and time consuming. Consequently, it is extremely useful if a full-scale structure can be replaced by a similar scaled-down model which is much easier to work with. Furthermore, a dramatic reduction in cost and time can be achieved, if available experimental data of a specific structure can be used to predict the behavior of a group of similar systems. This study investigates problems associated with the design of scaled models. Such study is important since it provides the necessary scaling laws, and the factors which affect the accuracy of the scale models. Similitude theory is employed to develop the necessary similarity conditions (scaling laws). Scaling laws provide relationship between a full-scale structure and its scale model, and can be used to extrapolate the experimental data of a small, inexpensive, and testable model into design information for a large prototype. Due to large number of design parameters, the identification of the principal scaling laws by conventional method (dimensional analysis) is tedious. Similitude theory based on governing equations of the structural system is more direct and simpler in execution. The difficulty of making completely similar scale models often leads to accept certain type of distortion from exact duplication of the prototype (partial similarity). Both complete and partial similarity are discussed. The procedure consists of systematically observing the effect of each parameter and corresponding scaling laws. Then acceptable intervals and limitations for these parameters and scaling laws are discussed. In each case, a set of valid scaling factors and corresponding response scaling laws that accurately predict the response of prototypes from experimental models is introduced. The examples used include rectangular laminated plates under destabilizing loads, applied individually, vibrational characteristics of same plates, as well as cylindrical bending of beam-plates.

Cycling transport safety quantification

NASA Astrophysics Data System (ADS)

Drbohlav, Jiri; Kocourek, Josef

2018-05-01

Dynamic interest in cycling transport brings the necessity to design safety cycling infrastructure. In las few years, couple of norms with safety elements have been designed and suggested for the cycling infrastructure. But these were not fully examined. The main parameter of suitable and fully functional transport infrastructure is the evaluation of its safety. Common evaluation of transport infrastructure safety is based on accident statistics. These statistics are suitable for motor vehicle transport but unsuitable for the cycling transport. Cycling infrastructure evaluation of safety is suitable for the traffic conflicts monitoring. The results of this method are fast, based on real traffic situations and can be applied on any traffic situations.

Gallium-arsenide process evaluation based on a RISC microprocessor example

NASA Astrophysics Data System (ADS)

Brown, Richard B.; Upton, Michael; Chandna, Ajay; Huff, Thomas R.; Mudge, Trevor N.; Oettel, Richard E.

1993-10-01

This work evaluates the features of a gallium-arsenide E/D MESFET process in which a 32-b RISC microprocessor was implemented. The design methodology and architecture of this prototype CPU are described. The performance sensitivity of the microprocessor and other large circuit blocks to different process parameters is analyzed, and recommendations for future process features, circuit approaches, and layout styles are made. These recommendations are reflected in the design of a second microprocessor using a more advanced process that achieves much higher density and performance.

Factorial design application in photocatalytic wastewater degradation from TNT industry-red water.

PubMed

Guz, Ricardo; de Moura, Cristiane; da Cunha, Mário Antônio Alves; Rodrigues, Marcio Barreto

2017-03-01

In trinitrotoluene (TNT) purification process, realized in industries, there are two washes carried out at the end of the procedure. The first is performed with vaporized water, from which the first effluent, called yellow water, is originated. Then, a second wash is performed using sodium sulfite, generating the red water effluent. The objective of this work was to get the best conditions for photocatalytic degradation of the second effluent, red water, in order to reduce toxicity and adjust legal parameters according to regulatory agencies for dumping these effluents into waterways. It has used a statistical evaluation for factor interaction (pH, concentration) that affects heterogeneous photocatalysis with titanium dioxide (TiO 2 ). Thus, the treatment applied in the factorial experimental design consisted of using a volume equal to 500 mL of the effluent to 0.1 % by batch treatment, which has changed TiO 2  pH and concentration, according to the design, with 20 min time for evaluation, where it was used as response to the reduction of UV-Vis absorption. According to the design responses, it has obtained optimum values for the parameters evaluated: pH = 6.5 and concentration of 100 mg/L of TiO 2 were shown to be efficient when applied to red water effluent, obtaining approximately 91 % of discoloration.

Probabilistic seismic hazard characterization and design parameters for the Pantex Plant

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

Bernreuter, D. L.; Foxall, W.; Savy, J. B.

1998-10-19

The Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) updated the seismic hazard and design parameters at the Pantex Plant. The probabilistic seismic hazard (PSH) estimates were first updated using the latest available data and knowledge from LLNL (1993, 1998), Frankel et al. (1996), and other relevant recent studies from several consulting companies. Special attention was given to account for the local seismicity and for the system of potentially active faults associated with the Amarillo-Wichita uplift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was taken from results of similar studies. Special attentionmore » was given to soil amplification factors for the site. Horizontal Peak Ground Acceleration (PGA) and 5% damped uniform hazard spectra were calculated for six return periods (100 yr., 500 yr., 1000 yr., 2000 yr., 10,000 yr., and 100,000 yr.). The design parameters were calculated following DOE standards (DOE-STD-1022 to 1024). Response spectra for design or evaluation of Performance Category 1 through 4 structures, systems, and components are presented.« less

Design of geometric phase measurement in EAST Tokamak

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

Lan, T.; Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031; Liu, H. Q., E-mail: hqliu@ipp.ac.cn

2016-07-15

The optimum scheme for geometric phase measurement in EAST Tokamak is proposed in this paper. The theoretical values of geometric phase for the probe beams of EAST Polarimeter-Interferometer (POINT) system are calculated by path integration in parameter space. Meanwhile, the influences of some controllable parameters on geometric phase are evaluated. The feasibility and challenge of distinguishing geometric effect in the POINT signal are also assessed in detail.

Computer-Based Model Calibration and Uncertainty Analysis: Terms and Concepts

DTIC Science & Technology

2015-07-01

uncertainty analyses throughout the lifecycle of planning, designing, and operating of Civil Works flood risk management projects as described in...value 95% of the time. In the frequentist approach to PE, model parameters area regarded as having true values, and their estimate is based on the...in catchment models. 1. Evaluating parameter uncertainty. Water Resources Research 19(5):1151–1172. Lee, P. M. 2012. Bayesian statistics: An

Global design of satellite constellations: a multi-criteria performance comparison of classical walker patterns and new design patterns

NASA Astrophysics Data System (ADS)

Lansard, Erick; Frayssinhes, Eric; Palmade, Jean-Luc

Basically, the problem of designing a multisatellite constellation exhibits a lot of parameters with many possible combinations: total number of satellites, orbital parameters of each individual satellite, number of orbital planes, number of satellites in each plane, spacings between satellites of each plane, spacings between orbital planes, relative phasings between consecutive orbital planes. Hopefully, some authors have theoretically solved this complex problem under simplified assumptions: the permanent (or continuous) coverage by a single and multiple satellites of the whole Earth and zonal areas has been entirely solved from a pure geometrical point of view. These solutions exhibit strong symmetry properties (e.g. Walker, Ballard, Rider, Draim constellations): altitude and inclination are identical, orbital planes and satellites are regularly spaced, etc. The problem with such constellations is their oversimplified and restricted geometrical assumption. In fact, the evaluation function which is used implicitly only takes into account the point-to-point visibility between users and satellites and does not deal with very important constraints and considerations that become mandatory when designing a real satellite system (e.g. robustness to satellite failures, total system cost, common view between satellites and ground stations, service availability and satellite reliability, launch and early operations phase, production constraints, etc.). An original and global methodology relying on a powerful optimization tool based on genetic algorithms has been developed at ALCATEL ESPACE. In this approach, symmetrical constellations can be used as initial conditions of the optimization process together with specific evaluation functions. A multi-criteria performance analysis is conducted and presented here in a parametric way in order to identify and evaluate the main sensitive parameters. Quantitative results are given for three examples in the fields of navigation, telecommunication and multimedia satellite systems. In particular, a new design pattern with very efficient properties in terms of robustness to satellite failures is presented and compared with classical Walker patterns.

Highway noise reduction barriers : a literature review.

DOT National Transportation Integrated Search

1973-01-01

This report describes the various parameters that must be considered in evaluating highway noise barriers. The information presented is based on the current state of the art and covers the effectiveness, designs, materials and costs of barriers.

On the estimation algorithm used in adaptive performance optimization of turbofan engines

NASA Technical Reports Server (NTRS)

Espana, Martin D.; Gilyard, Glenn B.

1993-01-01

The performance seeking control algorithm is designed to continuously optimize the performance of propulsion systems. The performance seeking control algorithm uses a nominal model of the propulsion system and estimates, in flight, the engine deviation parameters characterizing the engine deviations with respect to nominal conditions. In practice, because of measurement biases and/or model uncertainties, the estimated engine deviation parameters may not reflect the engine's actual off-nominal condition. This factor has a necessary impact on the overall performance seeking control scheme exacerbated by the open-loop character of the algorithm. The effects produced by unknown measurement biases over the estimation algorithm are evaluated. This evaluation allows for identification of the most critical measurements for application of the performance seeking control algorithm to an F100 engine. An equivalence relation between the biases and engine deviation parameters stems from an observability study; therefore, it is undecided whether the estimated engine deviation parameters represent the actual engine deviation or whether they simply reflect the measurement biases. A new algorithm, based on the engine's (steady-state) optimization model, is proposed and tested with flight data. When compared with previous Kalman filter schemes, based on local engine dynamic models, the new algorithm is easier to design and tune and it reduces the computational burden of the onboard computer.

Development of high strength, high temperature ceramics

NASA Technical Reports Server (NTRS)

Hall, W. B.

1982-01-01

Improvement in the high-pressure turbopumps, both fuel and oxidizer, in the Space Shuttle main engine were considered. The operation of these pumps is limited by temperature restrictions of the metallic components used in these pumps. Ceramic materials that retain strength at high temperatures and appear to be promising candidates for use as turbine blades and impellers are discussed. These high strength materials are sensitive to many related processing parameters such as impurities, sintering aids, reaction aids, particle size, processing temperature, and post thermal treatment. The specific objectives of the study were to: (1) identify and define the processing parameters that affect the properties of Si3N4 ceramic materials, (2) design and assembly equipment required for processing high strength ceramics, (3) design and assemble test apparatus for evaluating the high temperature properties of Si3N4, and (4) conduct a research program of manufacturing and evaluating Si3N4 materials as applicable to rocket engine applications.

An Analysis of Document Category Prediction Responses to Classifier Model Parameter Treatment Permutations within the Software Design Patterns Subject Domain

ERIC Educational Resources Information Center

Pankau, Brian L.

2009-01-01

This empirical study evaluates the document category prediction effectiveness of Naive Bayes (NB) and K-Nearest Neighbor (KNN) classifier treatments built from different feature selection and machine learning settings and trained and tested against textual corpora of 2300 Gang-Of-Four (GOF) design pattern documents. Analysis of the experiment's…

Structural analysis of three space crane articulated-truss joint concepts

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Sutter, Thomas R.

1992-01-01

Three space crane articulated truss joint concepts are studied to evaluate their static structural performance over a range of geometric design parameters. Emphasis is placed on maintaining the four longeron reference truss performance across the joint while allowing large angle articulation. A maximum positive articulation angle and the actuator length ratio required to reach the angle are computed for each concept as the design parameters are varied. Configurations with a maximum articulation angle less than 120 degrees or actuators requiring a length ratio over two are not considered. Tip rotation and lateral deflection of a truss beam with an articulated truss joint at the midspan are used to select a point design for each concept. Deflections for one point design are up to 40 percent higher than for the other two designs. Dynamic performance of the three point design is computed as a function of joint articulation angle. The two lowest frequencies of each point design are relatively insensitive to large variations in joint articulation angle. One point design has a higher maximum tip velocity for the emergency stop than the other designs.

Development of a design basis tornado and structural design criteria for Lawrence Livermore Laboratory's Site 300

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

McDonald, J.R.; Minor, J.E.; Mehta, K.C.

1975-11-01

Criteria are prescribed and guidance is provided for professional personnel who are involved with the evaluation of existing buildings and facilities at Site 300 near Livermore, California to resist the possible effects of extreme winds and tornadoes. The development of parameters for the effects of tornadoes and extreme winds and guidelines for evaluation and design of structures are presented. The investigations conducted are summarized and the techniques used for arriving at the combined tornado and extreme wind risk model are discussed. The guidelines for structural design methods for calculating pressure distributions on walls and roofs of structures and methods formore » accommodating impact loads from missiles are also presented. (auth)« less

Computational Analysis of an effect of aerodynamic pressure on the side view mirror geometry

NASA Astrophysics Data System (ADS)

Murukesavan, P.; Mu'tasim, M. A. N.; Sahat, I. M.

2013-12-01

This paper describes the evaluation of aerodynamic flow effects on side mirror geometry for a passenger car using ANSYS Fluent CFD simulation software. Results from analysis of pressure coefficient on side view mirror designs is evaluated to analyse the unsteady forces that cause fluctuations to mirror surface and image blurring. The fluctuation also causes drag forces that increase the overall drag coefficient, with an assumption resulting in higher fuel consumption and emission. Three features of side view mirror design were investigated with two input velocity parameters of 17 m/s and 33 m/s. Results indicate that the half-sphere design shows the most effective design with less pressure coefficient fluctuation and drag coefficient.

High-Level Performance Modeling of SAR Systems

NASA Technical Reports Server (NTRS)

Chen, Curtis

2006-01-01

SAUSAGE (Still Another Utility for SAR Analysis that s General and Extensible) is a computer program for modeling (see figure) the performance of synthetic- aperture radar (SAR) or interferometric synthetic-aperture radar (InSAR or IFSAR) systems. The user is assumed to be familiar with the basic principles of SAR imaging and interferometry. Given design parameters (e.g., altitude, power, and bandwidth) that characterize a radar system, the software predicts various performance metrics (e.g., signal-to-noise ratio and resolution). SAUSAGE is intended to be a general software tool for quick, high-level evaluation of radar designs; it is not meant to capture all the subtleties, nuances, and particulars of specific systems. SAUSAGE was written to facilitate the exploration of engineering tradeoffs within the multidimensional space of design parameters. Typically, this space is examined through an iterative process of adjusting the values of the design parameters and examining the effects of the adjustments on the overall performance of the system at each iteration. The software is designed to be modular and extensible to enable consideration of a variety of operating modes and antenna beam patterns, including, for example, strip-map and spotlight SAR acquisitions, polarimetry, burst modes, and squinted geometries.

Evaluation of EIT system performance.

PubMed

Yasin, Mamatjan; Böhm, Stephan; Gaggero, Pascal O; Adler, Andy

2011-07-01

An electrical impedance tomography (EIT) system images internal conductivity from surface electrical stimulation and measurement. Such systems necessarily comprise multiple design choices from cables and hardware design to calibration and image reconstruction. In order to compare EIT systems and study the consequences of changes in system performance, this paper describes a systematic approach to evaluate the performance of the EIT systems. The system to be tested is connected to a saline phantom in which calibrated contrasting test objects are systematically positioned using a position controller. A set of evaluation parameters are proposed which characterize (i) data and image noise, (ii) data accuracy, (iii) detectability of single contrasts and distinguishability of multiple contrasts, and (iv) accuracy of reconstructed image (amplitude, resolution, position and ringing). Using this approach, we evaluate three different EIT systems and illustrate the use of these tools to evaluate and compare performance. In order to facilitate the use of this approach, all details of the phantom, test objects and position controller design are made publicly available including the source code of the evaluation and reporting software.

Evaluation of High-Speed Civil Transport Handling Qualities Criteria with Supersonic Flight Data

NASA Technical Reports Server (NTRS)

Cox, Timothy H.; Jackson, Dante W.

1997-01-01

Most flying qualities criteria have been developed from data in the subsonic flight regime. Unique characteristics of supersonic flight raise questions about whether these criteria successfully extend into the supersonic flight regime. Approximately 25 years ago NASA Dryden Flight Research Center addressed this issue with handling qualities evaluations of the XB-70 and YF-12. Good correlations between some of the classical handling qualities parameters, such as the control anticipation parameter as a function of damping, were discovered. More criteria have been developed since these studies. Some of these more recent criteria are being used in designing the High-Speed Civil Transport (HSCT). A second research study recently addressed this issue through flying qualities evaluations of the SR-71 at Mach 3. The research goal was to extend the high-speed flying qualities experience of large airplanes and to evaluate more recent MIL-STD-1797 criteria against pilot comments and ratings. Emphasis was placed on evaluating the criteria used for designing the HSCT. XB-70 and YF-12 data from the previous research supplemented the SR-71 data. The results indicate that the criteria used in the HSCT design are conservative and should provide good flying qualities for typical high-speed maneuvering. Additional results show correlation between the ratings and comments and criteria for gradual maneuvering with precision control. Correlation is shown between ratings and comments and an extension of the Neal/Smith criterion using normal acceleration instead of pitch rate.

Support the Design of Improved IUE NEWSIPS High Dispersion Extraction Algorithms: Improved IUE High Dispersion Extraction Algorithms

NASA Technical Reports Server (NTRS)

Lawton, Pat

2004-01-01

The objective of this work was to support the design of improved IUE NEWSIPS high dispersion extraction algorithms. The purpose of this work was to evaluate use of the Linearized Image (LIHI) file versus the Re-Sampled Image (SIHI) file, evaluate various extraction, and design algorithms for evaluation of IUE High Dispersion spectra. It was concluded the use of the Re-Sampled Image (SIHI) file was acceptable. Since the Gaussian profile worked well for the core and the Lorentzian profile worked well for the wings, the Voigt profile was chosen for use in the extraction algorithm. It was found that the gamma and sigma parameters varied significantly across the detector, so gamma and sigma masks for the SWP detector were developed. Extraction code was written.

Linear laser diode arrays for improvement in optical disk recording for space stations

NASA Technical Reports Server (NTRS)

Alphonse, G. A.; Carlin, D. B.; Connolly, J. C.

1990-01-01

The design and fabrication of individually addressable laser diode arrays for high performance magneto-optic recording systems are presented. Ten diode arrays with 30 mW cW light output, linear light vs. current characteristics and single longitudinal mode spectrum were fabricated using channel substrate planar (CSP) structures. Preliminary results on the inverse CSP structure, whose fabrication is less critically dependent on device parameters than the CSP, are also presented. The impact of systems parameters and requirements, in particular, the effect of feedback on laser design is assessed, and techniques to reduce feedback or minimize its effect on systems performance, including mode-stabilized structures, are evaluated.

Experimental design for estimating parameters of rate-limited mass transfer: Analysis of stream tracer studies

USGS Publications Warehouse

Wagner, Brian J.; Harvey, Judson W.

1997-01-01

Tracer experiments are valuable tools for analyzing the transport characteristics of streams and their interactions with shallow groundwater. The focus of this work is the design of tracer studies in high-gradient stream systems subject to advection, dispersion, groundwater inflow, and exchange between the active channel and zones in surface or subsurface water where flow is stagnant or slow moving. We present a methodology for (1) evaluating and comparing alternative stream tracer experiment designs and (2) identifying those combinations of stream transport properties that pose limitations to parameter estimation and therefore a challenge to tracer test design. The methodology uses the concept of global parameter uncertainty analysis, which couples solute transport simulation with parameter uncertainty analysis in a Monte Carlo framework. Two general conclusions resulted from this work. First, the solute injection and sampling strategy has an important effect on the reliability of transport parameter estimates. We found that constant injection with sampling through concentration rise, plateau, and fall provided considerably more reliable parameter estimates than a pulse injection across the spectrum of transport scenarios likely encountered in high-gradient streams. Second, for a given tracer test design, the uncertainties in mass transfer and storage-zone parameter estimates are strongly dependent on the experimental Damkohler number, DaI, which is a dimensionless combination of the rates of exchange between the stream and storage zones, the stream-water velocity, and the stream reach length of the experiment. Parameter uncertainties are lowest at DaI values on the order of 1.0. When DaI values are much less than 1.0 (owing to high velocity, long exchange timescale, and/or short reach length), parameter uncertainties are high because only a small amount of tracer interacts with storage zones in the reach. For the opposite conditions (DaI ≫ 1.0), solute exchange rates are fast relative to stream-water velocity and all solute is exchanged with the storage zone over the experimental reach. As DaI increases, tracer dispersion caused by hyporheic exchange eventually reaches an equilibrium condition and storage-zone exchange parameters become essentially nonidentifiable.

IN718 Additive Manufacturing Properties and Influences

NASA Technical Reports Server (NTRS)

Lambert, Dennis M.

2015-01-01

The results of tensile, fracture, and fatigue testing of IN718 coupons produced using the selective laser melting (SLM) additive manufacturing technique are presented. The data have been "sanitized" to remove the numerical values, although certain references to material standards are provided. This document provides some knowledge of the effect of variation of controlled build parameters used in the SLM process, a snapshot of the capabilities of SLM in industry at present, and shares some of the lessons learned along the way. For the build parameter characterization, the parameters were varied over a range that was centered about the machine manufacturer's recommended value, and in each case they were varied individually, although some co-variance of those parameters would be expected. Tensile, fracture, and high-cycle fatigue properties equivalent to wrought IN718 are achievable with SLM-produced IN718. Build and post-build processes need to be determined and then controlled to established limits to accomplish this. It is recommended that a multi-variable evaluation, e.g., design-of experiment (DOE), of the build parameters be performed to better evaluate the co-variance of the parameters.

IN718 Additive Manufacturing Properties and Influences

NASA Technical Reports Server (NTRS)

Lambert, Dennis M.

2015-01-01

The results of tensile, fracture, and fatigue testing of IN718 coupons produced using the selective laser melting (SLM) additive manufacturing technique are presented. The data has been "generalized" to remove the numerical values, although certain references to material standards are provided. This document provides some knowledge of the effect of variation of controlled build parameters used in the SLM process, a snapshot of the capabilities of SLM in industry at present, and shares some of the lessons learned along the way. For the build parameter characterization, the parameters were varied over a range about the machine manufacturer's recommended value, and in each case they were varied individually, although some co-variance of those parameters would be expected. SLM-produced IN718, tensile, fracture, and high-cycle fatigue properties equivalent to wrought IN718 are achievable. Build and post-build processes need to be determined and then controlled to established limits to accomplish this. It is recommended that a multi-variable evaluation, e.g., design-of-experiment (DOE), of the build parameters be performed to better evaluate the co-variance of the parameters.

Calculation of Weibull strength parameters and Batdorf flow-density constants for volume- and surface-flaw-induced fracture in ceramics

NASA Technical Reports Server (NTRS)

Pai, Shantaram S.; Gyekenyesi, John P.

1988-01-01

The calculation of shape and scale parameters of the two-parameter Weibull distribution is described using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. Detailed procedures are given for evaluating 90 percent confidence intervals for maximum likelihood estimates of shape and scale parameters, the unbiased estimates of the shape parameters, and the Weibull mean values and corresponding standard deviations. Furthermore, the necessary steps are described for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull distribution. It also shows how to calculate the Batdorf flaw-density constants by uing the Weibull distribution statistical parameters. The techniques described were verified with several example problems, from the open literature, and were coded. The techniques described were verified with several example problems from the open literature, and were coded in the Structural Ceramics Analysis and Reliability Evaluation (SCARE) design program.

An analysis of fuel conserving operational procedures and design modifications for bomber/transport aircraft. Volume I. Executive summary. Final report, 7 June 1976-7 July 1978

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

Aggarwal, R.

1978-07-01

Various proposed improvements in the design and operational procedures for bomber/transport aircraft are evaluated. The evaluation is performed in terms of the estimated savings in fuel consumption and in Direct Operating Cost (DOC). As an aid in the evaluation of design modifications, graphs of fuel and DOC savings as a function of the design parameters are developed. These graphs are based on actual mission trajectory data rather than some type trajectory profile. The actual mission data is presented in terms of histograms which provide statistical information concerning altitude, air speed, take-off weight, landing weights, and mission time. Separate analyses aremore » performed on the following aircraft: the B-52G, the B-52H, the KC-135, the C-141, the C-130, and the C-5A.« less

An analysis of fuel conserving operational procedures and design modifications for bomber/transport aircraft. volume ii. Final report, 7 June 1976-7 July 1978

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

Aggarwal, R.K.

1978-07-01

Various proposed improvements in the design and operational procedures for bomber/transport aircraft are evaluated. The evaluation is performed in terms of the estimated savings in fuel consumption and in Direct Operating Cost (DOC). As an aid in the evaluation of design modifications, graphs of fuel and DOC savings as a function of the design parameters are developed. These graphs are based on actual mission trajectory data rather than some typical trajectory profile. The actual mission data is presented in terms of histograms which provide statistical information concerning altitude, air speed, take-off weight, landing weight, and mission time. Separate analyses aremore » performed on the following aircraft: the B-52G, the B-52H, the KC-135, the C-141, the C-130, and the C-5A. (Author)« less

Impact of Contact Lens Material, Design, and Fitting on Discomfort.

PubMed

Stapleton, Fiona; Tan, Jacqueline

2017-01-01

To review the effect of contact lens (CL) material, design, and fitting characteristics on CL discomfort. A PubMed search identified publications describing subjective comfort and CL material, fitting, and design parameters. The review included clinical signs associated with discomfort that may be a consequence of these parameters. Reduced lens movement or more CL tightness were associated with improved comfort. Increased lens-induced paralimbal conjunctival staining and indentation, considered as quasi-indicators of CL fitting or edge design, were also associated with better comfort. No recent studies have evaluated varying CL design parameters and subjective comfort. Silicone hydrogel CLs are no different in comfort compared with hydrogel CLs. Lower equilibrium water content is associated with improved comfort in hydrogel CL wear. Coefficient of friction shows promise as a material factor potentially associated with comfort. Lid wiper epitheliopathy and lid-parallel conjunctival folds have been linked with comfort in established wearers. Recent studies have confirmed the association between more mobile CLs and more discomfort, whereas closer conformity of the CL to the bulbar conjunctiva improved subjective comfort. There is no evidence to support the perceived comfort difference between silicone hydrogel and hydrogel CL. There has been limited progress in understanding the impact of varying specific CL design parameters. Although specific clinical signs may be predictive of discomfort, their role in the natural history of discomfort remains unclear. A better understanding of the relationship between coefficient of friction and comfort and strategies to improve lubricity may hold promise for limiting CL discomfort.

ASRM test report: Autoclave cure process development

NASA Technical Reports Server (NTRS)

Nachbar, D. L.; Mitchell, Suzanne

1992-01-01

ASRM insulated segments will be autoclave cured following insulation pre-form installation and strip wind operations. Following competitive bidding, Aerojet ASRM Division (AAD) Purchase Order 100142 was awarded to American Fuel Cell and Coated Fabrics Company, Inc. (Amfuel), Magnolia, AR, for subcontracted insulation autoclave cure process development. Autoclave cure process development test requirements were included in Task 3 of TM05514, Manufacturing Process Development Specification for Integrated Insulation Characterization and Stripwind Process Development. The test objective was to establish autoclave cure process parameters for ASRM insulated segments. Six tasks were completed to: (1) evaluate cure parameters that control acceptable vulcanization of ASRM Kevlar-filled EPDM insulation material; (2) identify first and second order impact parameters on the autoclave cure process; and (3) evaluate insulation material flow-out characteristics to support pre-form configuration design.

Interactive systems design and synthesis of future spacecraft concepts

NASA Technical Reports Server (NTRS)

Wright, R. L.; Deryder, D. D.; Ferebee, M. J., Jr.

1984-01-01

An interactive systems design and synthesis is performed on future spacecraft concepts using the Interactive Design and Evaluation of Advanced spacecraft (IDEAS) computer-aided design and analysis system. The capabilities and advantages of the systems-oriented interactive computer-aided design and analysis system are described. The synthesis of both large antenna and space station concepts, and space station evolutionary growth is demonstrated. The IDEAS program provides the user with both an interactive graphics and an interactive computing capability which consists of over 40 multidisciplinary synthesis and analysis modules. Thus, the user can create, analyze and conduct parametric studies and modify Earth-orbiting spacecraft designs (space stations, large antennas or platforms, and technologically advanced spacecraft) at an interactive terminal with relative ease. The IDEAS approach is useful during the conceptual design phase of advanced space missions when a multiplicity of parameters and concepts must be analyzed and evaluated in a cost-effective and timely manner.

Designing a capacitated multi-configuration logistics network under disturbances and parameter uncertainty: a real-world case of a drug supply chain

NASA Astrophysics Data System (ADS)

Shishebori, Davood; Babadi, Abolghasem Yousefi

2018-03-01

This study investigates the reliable multi-configuration capacitated logistics network design problem (RMCLNDP) under system disturbances, which relates to locating facilities, establishing transportation links, and also allocating their limited capacities to the customers conducive to provide their demand on the minimum expected total cost (including locating costs, link constructing costs, and also expected costs in normal and disturbance conditions). In addition, two types of risks are considered; (I) uncertain environment, (II) system disturbances. A two-level mathematical model is proposed for formulating of the mentioned problem. Also, because of the uncertain parameters of the model, an efficacious possibilistic robust optimization approach is utilized. To evaluate the model, a drug supply chain design (SCN) is studied. Finally, an extensive sensitivity analysis was done on the critical parameters. The obtained results show that the efficiency of the proposed approach is suitable and is worthwhile for analyzing the real practical problems.

Nuclear Electric Vehicle Optimization Toolset (NEVOT): Integrated System Design Using Genetic Algorithms

NASA Technical Reports Server (NTRS)

Tinker, Michael L.; Steincamp, James W.; Stewart, Eric T.; Patton, Bruce W.; Pannell, William P.; Newby, Ronald L.; Coffman, Mark E.; Qualls, A. L.; Bancroft, S.; Molvik, Greg

2003-01-01

The Nuclear Electric Vehicle Optimization Toolset (NEVOT) optimizes the design of all major Nuclear Electric Propulsion (NEP) vehicle subsystems for a defined mission within constraints and optimization parameters chosen by a user. The tool uses a Genetic Algorithm (GA) search technique to combine subsystem designs and evaluate the fitness of the integrated design to fulfill a mission. The fitness of an individual is used within the GA to determine its probability of survival through successive generations in which the designs with low fitness are eliminated and replaced with combinations or mutations of designs with higher fitness. The program can find optimal solutions for different sets of fitness metrics without modification and can create and evaluate vehicle designs that might never be conceived of through traditional design techniques. It is anticipated that the flexible optimization methodology will expand present knowledge of the design trade-offs inherent in designing nuclear powered space vehicles and lead to improved NEP designs.

SU-F-T-366: Dosimetric Parameters Enhancement of 120-Leaf Millennium MLC Using EGSnrc and IAEA Phase-Space Data

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

Haddad, K; Alopoor, H

Purpose: Recently, the multileaf collimators (MLC) have become an important part of any LINAC collimation systems because they reduce the treatment planning time and improves the conformity. Important factors that affects the MLCs collimation performance are leaves material composition and their thickness. In this study, we investigate the main dosimetric parameters of 120-leaf Millennium MLC including dose in the buildup point, physical penumbra as well as average and end leaf leakages. Effects of the leaves geometry and density on these parameters are evaluated Methods: From EGSnrc Monte Carlo code, BEAMnrc and DOSXYZnrc modules are used to evaluate the dosimetric parametersmore » of a water phantom exposed to a Varian xi for 100cm SSD. Using IAEA phasespace data just above MLC (Z=46cm) and BEAMnrc, for the modified 120-leaf Millennium MLC a new phase space data at Z=52cm is produces. The MLC is modified both in leaf thickness and material composition. EGSgui code generates 521ICRU library for tungsten alloys. DOSXYZnrc with the new phase space evaluates the dose distribution in a water phantom of 60×60×20 cm3 with voxel size of 4×4×2 mm3. Using DOSXYZnrc dose distributions for open beam and closed beam as well as the leakages definition, end leakage, average leakage and physical penumbra are evaluated. Results: A new MLC with improved dosimetric parameters is proposed. The physical penumbra for proposed MLC is 4.7mm compared to 5.16 mm for Millennium. Average leakage in our design is reduced to 1.16% compared to 1.73% for Millennium, the end leaf leakage suggested design is also reduced to 4.86% compared to 7.26% of Millennium. Conclusion: The results show that the proposed MLC with enhanced dosimetric parameters could improve the conformity of treatment planning.« less

Development and Evaluation of Titanium Spacesuit Bearings

NASA Technical Reports Server (NTRS)

Rhodes, Richard; Battisti, Brian; Ytuarte, Raymond, Jr.; Schultz, Bradley

2016-01-01

The Z-2 Prototype Planetary Extravehicular Space Suit Assembly is a continuation of NASA's Z-series of spacesuits, designed with the intent of meeting a wide variety of exploration mission objectives, including human exploration of the Martian surface. Incorporating titanium bearings into the Z-series space suit architecture allows us to reduce mass by an estimated 23 lbs per suit system compared to the previously used stainless steel bearing race designs, without compromising suit functionality. There are two obstacles to overcome when using titanium for a bearing race- 1) titanium is flammable when exposed to the oxygen wetted environment inside the space suit and 2) titanium's poor wear properties are often challenging to overcome in tribology applications. In order to evaluate the ignitability of a titanium space suit bearing, a series of tests were conducted at White Sands Test Facility (WSTF) that introduced the bearings to an extreme test profile, with multiple failures imbedded into the test bearings. The testing showed no signs of ignition in the most extreme test cases; however, substantial wear of the bearing races was observed. In order to design a bearing that can last an entire exploration mission (approx. 3 years), design parameters for maximum contact stress need to be identified. To identify these design parameters, bearing test rigs were developed that allow for the quick evaluation of various bearing ball loads, ball diameters, lubricants, and surface treatments. This test data will allow designers to minimize the titanium bearing mass for a specific material and lubricant combination and design around a cycle life requirement for an exploration mission. This paper reviews the current research and testing that has been performed on titanium bearing races to evaluate the use of such materials in an enriched oxygen environment and to optimize the bearing assembly mass and tribological properties to accommodate for the high bearing cycle life for an exploration mission.

Systematic modelling and design evaluation of unperturbed tumour dynamics in xenografts.

PubMed

Parra Guillen, Zinnia P Patricia; Mangas Sanjuan, Victor; Garcia-Cremades, Maria; Troconiz, Inaki F; Mo, Gary; Pitou, Celine; Iversen, Philip W; Wallin, Johan E

2018-04-24

Xenograft mice are largely used to evaluate the efficacy of oncological drugs during preclinical phases of drug discovery and development. Mathematical models provide a useful tool to quantitatively characterise tumour growth dynamics and also optimise upcoming experiments. To the best of our knowledge, this is the first report where unperturbed growth of a large set of tumour cell lines (n=28) has been systematically analysed using the model proposed by Simeoni in the context of non-linear mixed effect (NLME). Exponential growth was identified as the governing mechanism in the majority of the cell lines, with constant rate values ranging from 0.0204 to 0.203 day -1 No common patterns could be observed across tumour types, highlighting the importance of combining information from different cell lines when evaluating drug activity. Overall, typical model parameters were precisely estimated using designs where tumour size measurements were taken every two days. Moreover, reducing the number of measurement to twice per week, or even once per week for cell lines with low growth rates, showed little impact on parameter precision. However, in order to accurately characterise parameter variability (i.e. relative standard errors below 50%), a sample size of at least 50 mice is needed. This work illustrates the feasibility to systematically apply NLME models to characterise tumour growth in drug discovery and development, and constitutes a valuable source of data to optimise experimental designs by providing an a priori sampling window and minimising the number of samples required. The American Society for Pharmacology and Experimental Therapeutics.

Quantitative comparison of randomization designs in sequential clinical trials based on treatment balance and allocation randomness.

PubMed

Zhao, Wenle; Weng, Yanqiu; Wu, Qi; Palesch, Yuko

2012-01-01

To evaluate the performance of randomization designs under various parameter settings and trial sample sizes, and identify optimal designs with respect to both treatment imbalance and allocation randomness, we evaluate 260 design scenarios from 14 randomization designs under 15 sample sizes range from 10 to 300, using three measures for imbalance and three measures for randomness. The maximum absolute imbalance and the correct guess (CG) probability are selected to assess the trade-off performance of each randomization design. As measured by the maximum absolute imbalance and the CG probability, we found that performances of the 14 randomization designs are located in a closed region with the upper boundary (worst case) given by Efron's biased coin design (BCD) and the lower boundary (best case) from the Soares and Wu's big stick design (BSD). Designs close to the lower boundary provide a smaller imbalance and a higher randomness than designs close to the upper boundary. Our research suggested that optimization of randomization design is possible based on quantified evaluation of imbalance and randomness. Based on the maximum imbalance and CG probability, the BSD, Chen's biased coin design with imbalance tolerance method, and Chen's Ehrenfest urn design perform better than popularly used permuted block design, EBCD, and Wei's urn design. Copyright © 2011 John Wiley & Sons, Ltd.

Neural-genetic synthesis for state-space controllers based on linear quadratic regulator design for eigenstructure assignment.

PubMed

da Fonseca Neto, João Viana; Abreu, Ivanildo Silva; da Silva, Fábio Nogueira

2010-04-01

Toward the synthesis of state-space controllers, a neural-genetic model based on the linear quadratic regulator design for the eigenstructure assignment of multivariable dynamic systems is presented. The neural-genetic model represents a fusion of a genetic algorithm and a recurrent neural network (RNN) to perform the selection of the weighting matrices and the algebraic Riccati equation solution, respectively. A fourth-order electric circuit model is used to evaluate the convergence of the computational intelligence paradigms and the control design method performance. The genetic search convergence evaluation is performed in terms of the fitness function statistics and the RNN convergence, which is evaluated by landscapes of the energy and norm, as a function of the parameter deviations. The control problem solution is evaluated in the time and frequency domains by the impulse response, singular values, and modal analysis.

Thermal stress analysis of ceramic gas-path seal components for aircraft turbines

NASA Technical Reports Server (NTRS)

Kennedy, F. E.; Bill, R. C.

1979-01-01

Stress and temperature distributions were evaluated numerically for a blade-tip seal system proposed for gas turbine applications. The seal consists of an abradable ceramic layer on metallic backing with intermediate layers between the ceramic layer and metal substrate. The most severe stresses in the seal, as far as failure is concerned, are tensile stresses at the top of the ceramic layer and shear and normal stresses at the layer interfaces. All these stresses reach their maximum values during the deceleration phase of a test engine cycle. A parametric study was carried out to evaluate the influence of various design parameters on these critical stress values. The influences of material properties and geometric parameters of the ceramic, intermediate, and backing layers were investigated. After the parametric study was completed, a seal system was designed which incorporated materials with beneficial elastic and thermal properties in each layer of the seal. An analysis of the proposed seal design shows an appreciable decrease in the magnitude of the maximum critical stresses over those obtained with earlier configurations.

External fuel vaporization study, phase 2

NASA Technical Reports Server (NTRS)

Szetela, E. J.; Chiappetta, L.

1981-01-01

An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

Post-Optimality Analysis In Aerospace Vehicle Design

NASA Technical Reports Server (NTRS)

Braun, Robert D.; Kroo, Ilan M.; Gage, Peter J.

1993-01-01

This analysis pertains to the applicability of optimal sensitivity information to aerospace vehicle design. An optimal sensitivity (or post-optimality) analysis refers to computations performed once the initial optimization problem is solved. These computations may be used to characterize the design space about the present solution and infer changes in this solution as a result of constraint or parameter variations, without reoptimizing the entire system. The present analysis demonstrates that post-optimality information generated through first-order computations can be used to accurately predict the effect of constraint and parameter perturbations on the optimal solution. This assessment is based on the solution of an aircraft design problem in which the post-optimality estimates are shown to be within a few percent of the true solution over the practical range of constraint and parameter variations. Through solution of a reusable, single-stage-to-orbit, launch vehicle design problem, this optimal sensitivity information is also shown to improve the efficiency of the design process, For a hierarchically decomposed problem, this computational efficiency is realized by estimating the main-problem objective gradient through optimal sep&ivity calculations, By reducing the need for finite differentiation of a re-optimized subproblem, a significant decrease in the number of objective function evaluations required to reach the optimal solution is obtained.

Study to investigate and evaluate means of optimizing the radar function. [systems engineering of pulse radar for the space shuttle

NASA Technical Reports Server (NTRS)

1975-01-01

The investigations for a rendezvous radar system design and an integrated radar/communication system design are presented. Based on these investigations, system block diagrams are given and system parameters are optimized for the noncoherent pulse and coherent pulse Doppler radar modulation types. Both cooperative (transponder) and passive radar operation are examined including the optimization of the corresponding transponder design for the cooperative mode of operation.

Does an alteration of dialyzer design and geometry affect biocompatibility parameters?

PubMed

Opatrný, Karel; Krouzzecký, Ales; Polanská, Kamila; Mares, Jan; Tomsů, Martina; Bowry, Sudhir K; Vienken, Jörg

2006-04-01

The aim of the study was to assess the biocompatibility profile of a newly developed high-flux polysulfone dialyzer type (FX-class dialyzer). The new class of dialyzers incorporates a number of novel design features (including a new membrane) that have been developed specifically in order to enhance the removal of small- and middle-size molecules. The new FX dialyzer series was compared with the classical routinely used high-flux polysulfone F series of dialyzers. In an open prospective, randomized, crossover clinical study, concentrations of the C5a complement component, and leukocyte count in blood and various thrombogenicity parameters were evaluated before, and at 15 and 60 min of hemodialysis at both dialyzer inlet and outlet in 9 long-term hemodialysis patients using the FX60S dialyzers and, after crossover, the classical F60S, while in another 9 patients, the evaluation was made with the dialyzers used in reverse order. The comparison of dialyzers based on evaluation of the group including all procedures with the FX60S and the group including procedures with the F60S did not reveal significant differences in platelet count, activated partial thromboplastin times, plasma heparin levels, platelet factor-4, D-dimer, C5a, and leukocyte count at any point of the collecting period. Both dialyzer types showed a significant increase in the plasma levels of the thrombin-antithrombin III complexes; however, the measured levels were only slightly elevated compared with the upper end of the normal range. Biocompatibility parameters reflecting the behavior of platelets, fibrinolysis, complement activation, and leukopenia do not differ during dialysis with either the FX60S or the F60S despite their large differences in design and geometry features. Although coagulation activation, as evaluated by one of the parameters used, was slightly higher with the FX60S, it was still within the range seen with other highly biocompatible dialyzers and therefore is not indicative of any appreciable activation of the coagulation system. Thus, the incorporation of various performance-enhancing design features into the new FX class of dialyzers does not result in a deterioration of their biocompatibility profile, which is comparable to that of the classical F series of dialyzers.

A Systematic Approach of Employing Quality by Design Principles: Risk Assessment and Design of Experiments to Demonstrate Process Understanding and Identify the Critical Process Parameters for Coating of the Ethylcellulose Pseudolatex Dispersion Using Non-Conventional Fluid Bed Process.

PubMed

Kothari, Bhaveshkumar H; Fahmy, Raafat; Claycamp, H Gregg; Moore, Christine M V; Chatterjee, Sharmista; Hoag, Stephen W

2017-05-01

The goal of this study was to utilize risk assessment techniques and statistical design of experiments (DoE) to gain process understanding and to identify critical process parameters for the manufacture of controlled release multiparticulate beads using a novel disk-jet fluid bed technology. The material attributes and process parameters were systematically assessed using the Ishikawa fish bone diagram and failure mode and effect analysis (FMEA) risk assessment methods. The high risk attributes identified by the FMEA analysis were further explored using resolution V fractional factorial design. To gain an understanding of the processing parameters, a resolution V fractional factorial study was conducted. Using knowledge gained from the resolution V study, a resolution IV fractional factorial study was conducted; the purpose of this IV study was to identify the critical process parameters (CPP) that impact the critical quality attributes and understand the influence of these parameters on film formation. For both studies, the microclimate, atomization pressure, inlet air volume, product temperature (during spraying and curing), curing time, and percent solids in the coating solutions were studied. The responses evaluated were percent agglomeration, percent fines, percent yield, bead aspect ratio, median particle size diameter (d50), assay, and drug release rate. Pyrobuttons® were used to record real-time temperature and humidity changes in the fluid bed. The risk assessment methods and process analytical tools helped to understand the novel disk-jet technology and to systematically develop models of the coating process parameters like process efficiency and the extent of curing during the coating process.

Rotorcraft system identification techniques for handling qualities and stability and control evaluation

NASA Technical Reports Server (NTRS)

Hall, W. E., Jr.; Gupta, N. K.; Hansen, R. S.

1978-01-01

An integrated approach to rotorcraft system identification is described. This approach consists of sequential application of (1) data filtering to estimate states of the system and sensor errors, (2) model structure estimation to isolate significant model effects, and (3) parameter identification to quantify the coefficient of the model. An input design algorithm is described which can be used to design control inputs which maximize parameter estimation accuracy. Details of each aspect of the rotorcraft identification approach are given. Examples of both simulated and actual flight data processing are given to illustrate each phase of processing. The procedure is shown to provide means of calibrating sensor errors in flight data, quantifying high order state variable models from the flight data, and consequently computing related stability and control design models.

[Design of low-intermediate frequency electrotherapy and pain assessment system].

PubMed

Liang, Chunyan; Tian, Xuelong; Yu, Xuehong; Luo, Hongyan

2014-06-01

Aiming at the single treatment and the design separation between treatment and assessment in electrotherapy equipment, a kind of system including low-intermediate frequency treatment and efficacy evaluation was developed. With C8051F020 single-chip microcomputer as the core and the circuit design and software programming used, the system realized the random switch of therapeutic parameters, the collection, display and data storage of pressure pain threshold in the assessment. Experiment results showed that the stimulus waveform, current intensity, frequency, duty ratio of the system output were adjustable, accurate and reliable. The obtained pressure pain threshold had a higher accuracy (< 0.3 N) and better stability, guiding the parameter choice in the precise electrical stimulation. It, therefore, provides a reliable technical support for the treatment and curative effect assessment.

Bayesian experimental design for models with intractable likelihoods.

PubMed

Drovandi, Christopher C; Pettitt, Anthony N

2013-12-01

In this paper we present a methodology for designing experiments for efficiently estimating the parameters of models with computationally intractable likelihoods. The approach combines a commonly used methodology for robust experimental design, based on Markov chain Monte Carlo sampling, with approximate Bayesian computation (ABC) to ensure that no likelihood evaluations are required. The utility function considered for precise parameter estimation is based upon the precision of the ABC posterior distribution, which we form efficiently via the ABC rejection algorithm based on pre-computed model simulations. Our focus is on stochastic models and, in particular, we investigate the methodology for Markov process models of epidemics and macroparasite population evolution. The macroparasite example involves a multivariate process and we assess the loss of information from not observing all variables. © 2013, The International Biometric Society.

Scalability of surrogate-assisted multi-objective optimization of antenna structures exploiting variable-fidelity electromagnetic simulation models

NASA Astrophysics Data System (ADS)

Koziel, Slawomir; Bekasiewicz, Adrian

2016-10-01

Multi-objective optimization of antenna structures is a challenging task owing to the high computational cost of evaluating the design objectives as well as the large number of adjustable parameters. Design speed-up can be achieved by means of surrogate-based optimization techniques. In particular, a combination of variable-fidelity electromagnetic (EM) simulations, design space reduction techniques, response surface approximation models and design refinement methods permits identification of the Pareto-optimal set of designs within a reasonable timeframe. Here, a study concerning the scalability of surrogate-assisted multi-objective antenna design is carried out based on a set of benchmark problems, with the dimensionality of the design space ranging from six to 24 and a CPU cost of the EM antenna model from 10 to 20 min per simulation. Numerical results indicate that the computational overhead of the design process increases more or less quadratically with the number of adjustable geometric parameters of the antenna structure at hand, which is a promising result from the point of view of handling even more complex problems.

Empirical Validation of Indices for Consideration in the Revision of Recommended Senior School Financial Accounting Textbooks in Southwestern Nigeria

ERIC Educational Resources Information Center

Oyetoro, Oyebode Stephen; Ojo, Oloyede Ezekiel

2017-01-01

The study determined a significant difference in teachers' overall evaluations of six recommended Financial Accounting Textbooks in Southwestern Nigeria. It also assessed the specific evaluation parameters that account for the difference. It adopted the survey research design. The multistage sampling technique was used to select a total of 80…

Updating the limit efficiency of silicon solar cells

NASA Technical Reports Server (NTRS)

Wolf, M.

1979-01-01

Evaluation of the limit efficiency based on the simplest, most basic mathematical method that is appropriate for the conditions imposed by the cell model is discussed. The methodology, the solar cell structure, and the selection of the material parameters used in the evaluation are described. The results are discussed including a set of design goals derived from the limit efficiency.

Probabilistic Structural Evaluation of Uncertainties in Radiator Sandwich Panel Design

NASA Technical Reports Server (NTRS)

Kuguoglu, Latife; Ludwiczak, Damian

2006-01-01

The Jupiter Icy Moons Orbiter (JIMO) Space System is part of the NASA's Prometheus Program. As part of the JIMO engineering team at NASA Glenn Research Center, the structural design of the JIMO Heat Rejection Subsystem (HRS) is evaluated. An initial goal of this study was to perform sensitivity analyses to determine the relative importance of the input variables on the structural responses of the radiator panel. The desire was to let the sensitivity analysis information identify the important parameters. The probabilistic analysis methods illustrated here support this objective. The probabilistic structural performance evaluation of a HRS radiator sandwich panel was performed. The radiator panel structural performance was assessed in the presence of uncertainties in the loading, fabrication process variables, and material properties. The stress and displacement contours of the deterministic structural analysis at mean probability was performed and results presented. It is followed by a probabilistic evaluation to determine the effect of the primitive variables on the radiator panel structural performance. Based on uncertainties in material properties, structural geometry and loading, the results of the displacement and stress analysis are used as an input file for the probabilistic analysis of the panel. The sensitivity of the structural responses, such as maximum displacement and maximum tensile and compressive stresses of the facesheet in x and y directions and maximum VonMises stresses of the tube, to the loading and design variables is determined under the boundary condition where all edges of the radiator panel are pinned. Based on this study, design critical material and geometric parameters of the considered sandwich panel are identified.

Study on Topology Optimization Design, Manufacturability, and Performance Evaluation of Ti-6Al-4V Porous Structures Fabricated by Selective Laser Melting (SLM)

PubMed Central

Xu, Yangli; Zhang, Dongyun; Zhou, Yan; Wang, Weidong; Cao, Xuanyang

2017-01-01

The combination of topology optimization (TOP) and selective laser melting (SLM) provides the possibility of fabricating the complex, lightweight and high performance geometries overcoming the traditional manufacturing “bottleneck”. This paper evaluates the biomechanical properties of porous structures with porosity from 40% to 80% and unit cell size from 2 to 8 mm, which are designed by TOP and manufactured by SLM. During manufacturability exploration, three typical structures including spiral structure, arched bridge structure and structures with thin walls and small holes are abstracted and investigated, analyzing their manufacturing limits and forming reason. The property tests show that dynamic elastic modulus and compressive strength of porous structures decreases with increases of porosity (constant unit cell size) or unit cell size (constant porosity). Based on the Gibson-Ashby model, three failure models are proposed to describe their compressive behavior, and the structural parameter λ is used to evaluate the stability of the porous structure. Finally, a numerical model for the correlation between porous structural parameters (unit cell size and porosity) and elastic modulus is established, which provides a theoretical reference for matching the elastic modulus of human bones from different age, gender and skeletal sites during innovative medical implant design and manufacturing. PMID:28880229

Study on Topology Optimization Design, Manufacturability, and Performance Evaluation of Ti-6Al-4V Porous Structures Fabricated by Selective Laser Melting (SLM).

PubMed

Xu, Yangli; Zhang, Dongyun; Zhou, Yan; Wang, Weidong; Cao, Xuanyang

2017-09-07

The combination of topology optimization (TOP) and selective laser melting (SLM) provides the possibility of fabricating the complex, lightweight and high performance geometries overcoming the traditional manufacturing "bottleneck". This paper evaluates the biomechanical properties of porous structures with porosity from 40% to 80% and unit cell size from 2 to 8 mm, which are designed by TOP and manufactured by SLM. During manufacturability exploration, three typical structures including spiral structure, arched bridge structure and structures with thin walls and small holes are abstracted and investigated, analyzing their manufacturing limits and forming reason. The property tests show that dynamic elastic modulus and compressive strength of porous structures decreases with increases of porosity (constant unit cell size) or unit cell size (constant porosity). Based on the Gibson-Ashby model, three failure models are proposed to describe their compressive behavior, and the structural parameter λ is used to evaluate the stability of the porous structure. Finally, a numerical model for the correlation between porous structural parameters (unit cell size and porosity) and elastic modulus is established, which provides a theoretical reference for matching the elastic modulus of human bones from different age, gender and skeletal sites during innovative medical implant design and manufacturing.

SIPSim: A Modeling Toolkit to Predict Accuracy and Aid Design of DNA-SIP Experiments.

PubMed

Youngblut, Nicholas D; Barnett, Samuel E; Buckley, Daniel H

2018-01-01

DNA Stable isotope probing (DNA-SIP) is a powerful method that links identity to function within microbial communities. The combination of DNA-SIP with multiplexed high throughput DNA sequencing enables simultaneous mapping of in situ assimilation dynamics for thousands of microbial taxonomic units. Hence, high throughput sequencing enabled SIP has enormous potential to reveal patterns of carbon and nitrogen exchange within microbial food webs. There are several different methods for analyzing DNA-SIP data and despite the power of SIP experiments, it remains difficult to comprehensively evaluate method accuracy across a wide range of experimental parameters. We have developed a toolset (SIPSim) that simulates DNA-SIP data, and we use this toolset to systematically evaluate different methods for analyzing DNA-SIP data. Specifically, we employ SIPSim to evaluate the effects that key experimental parameters (e.g., level of isotopic enrichment, number of labeled taxa, relative abundance of labeled taxa, community richness, community evenness, and beta-diversity) have on the specificity, sensitivity, and balanced accuracy (defined as the product of specificity and sensitivity) of DNA-SIP analyses. Furthermore, SIPSim can predict analytical accuracy and power as a function of experimental design and community characteristics, and thus should be of great use in the design and interpretation of DNA-SIP experiments.

SIPSim: A Modeling Toolkit to Predict Accuracy and Aid Design of DNA-SIP Experiments

PubMed Central

Youngblut, Nicholas D.; Barnett, Samuel E.; Buckley, Daniel H.

2018-01-01

DNA Stable isotope probing (DNA-SIP) is a powerful method that links identity to function within microbial communities. The combination of DNA-SIP with multiplexed high throughput DNA sequencing enables simultaneous mapping of in situ assimilation dynamics for thousands of microbial taxonomic units. Hence, high throughput sequencing enabled SIP has enormous potential to reveal patterns of carbon and nitrogen exchange within microbial food webs. There are several different methods for analyzing DNA-SIP data and despite the power of SIP experiments, it remains difficult to comprehensively evaluate method accuracy across a wide range of experimental parameters. We have developed a toolset (SIPSim) that simulates DNA-SIP data, and we use this toolset to systematically evaluate different methods for analyzing DNA-SIP data. Specifically, we employ SIPSim to evaluate the effects that key experimental parameters (e.g., level of isotopic enrichment, number of labeled taxa, relative abundance of labeled taxa, community richness, community evenness, and beta-diversity) have on the specificity, sensitivity, and balanced accuracy (defined as the product of specificity and sensitivity) of DNA-SIP analyses. Furthermore, SIPSim can predict analytical accuracy and power as a function of experimental design and community characteristics, and thus should be of great use in the design and interpretation of DNA-SIP experiments. PMID:29643843

Space Storable Propellant Performance Gas/Liquid Like-Doublet Injector Characterization

NASA Technical Reports Server (NTRS)

Falk, A. Y.

1972-01-01

A 30-month applied research program was conducted, encompassing an analytical, design, and experimental effort to relate injector design parameters to simultaneous attainment of high performance and component (injector/thrust chamber) compatibility for gas/liquid space-storable propellants. The gas/liquid propellant combination selected for study was FLOX (82.6% F2)/ambient temperature gaseous methane. The injector pattern characterized was the like-(self)-impinging doublet. Program effort was apportioned into four basic technical tasks: injector and thrust chamber design, injector and thrust chamber fabrication, performance evaluation testing, and data evaluation and reporting. Analytical parametric combustion analyses and cold flow distribution and atomization experiments were conducted with injector segment models to support design of injector/thrust chamber combinations for hot fire evaluation. Hot fire tests were conducted to: (1) optimize performance of the injector core elements, and (2) provide design criteria for the outer zone elements so that injector/thrust chamber compatibility could be achieved with only minimal performance losses.

Determination of the influence of factors (ethanol, pH and a(w) ) on the preservation of cosmetics using experimental design.

PubMed

Berthele, H; Sella, O; Lavarde, M; Mielcarek, C; Pense-Lheritier, A-M; Pirnay, S

2014-02-01

Ethanol, pH and water activity are three well-known parameters that can influence the preservation of cosmetic products. With the new constraints regarding the antimicrobial effectiveness and the restrictive use of preservatives, a D-optimal design was set up to evaluate the influence of these three parameters on the microbiological conservation. To monitor the effectiveness of the different combination of these set parameters, a challenge test in compliance with the International standard ISO 11930: 2012 was implemented. The formulations established in our study could support wide variations of ethanol concentration, pH values and glycerin concentration without noticeable effects on the stability of the products. In the conditions of the study, determining the value of a single parameter, with the tested concentration, could not guarantee microbiological conservation. However, a high concentration of ethanol associated with an extreme pH could inhibit bacteria growth from the first day (D0). Besides, it appears that despite an aw above 0.6 (even 0.8) and without any preservatives incorporated in formulas, it was possible to guarantee the microbiological stability of the cosmetic product when maintaining the right combination of the selected parameters. Following the analysis of the different values obtained during the experimentation, there seems to be a correlation between the aw and the selected parameters aforementioned. An application of this relationship could be to define the aw of cosmetic products by using the formula, thus avoiding the evaluation of this parameter with a measuring device. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

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.

Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma

PubMed Central

Begum, Viquar Unnisa; Addepalli, Uday Kumar; Senthil, Sirisha; Garudadri, Chandra Sekhar; Rao, Harsha Laxmana

2016-01-01

Background: Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma. Purpose: To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma. Design: Cross-sectional analysis. Methods: 35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations. Statistical Analysis: Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR). Results: Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P < 0.001 for all comparisons). AUCs of all HD-OCT ONH parameters (0.90-0.97 in perimetric and 0.62-0.71 in preperimetric glaucoma) were comparable (P > 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma. Conclusions: ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma. PMID:27221679

Computer-Assisted Optimization of Electrodeposited Hydroxyapatite Coating Parameters on Medical Alloys

NASA Astrophysics Data System (ADS)

Coşkun, M. İbrahim; Karahan, İsmail H.; Yücel, Yasin; Golden, Teresa D.

2016-04-01

CoCrMo bio-metallic alloys were coated with a hydroxyapatite (HA) film by electrodeposition using various electrochemical parameters. Response surface methodology and central composite design were used to optimize deposition parameters such as electrolyte pH, deposition potential, and deposition time. The effects of the coating parameters were evaluated within the limits of solution pH (3.66 to 5.34), deposition potential (-1.13 to -1.97 V), and deposition time (6.36 to 73.64 minutes). A 5-level-3-factor experimental plan was used to determine ideal deposition parameters. Optimum conditions for the deposition parameters of the HA coating with high in vitro corrosion performance were determined as electrolyte pH of 5.00, deposition potential of -1.8 V, and deposition time of 20 minutes.

Impact investigation of reactor fuel operating parameters on reactivity for use in burnup credit applications

NASA Astrophysics Data System (ADS)

Sloma, Tanya Noel

When representing the behavior of commercial spent nuclear fuel (SNF), credit is sought for the reduced reactivity associated with the net depletion of fissile isotopes and the creation of neutron-absorbing isotopes, a process that begins when a commercial nuclear reactor is first operated at power. Burnup credit accounts for the reduced reactivity potential of a fuel assembly and varies with the fuel burnup, cooling time, and the initial enrichment of fissile material in the fuel. With regard to long-term SNF disposal and transportation, tremendous benefits, such as increased capacity, flexibility of design and system operations, and reduced overall costs, provide an incentive to seek burnup credit for criticality safety evaluations. The Nuclear Regulatory Commission issued Interim Staff Guidance 8, Revision 2 in 2002, endorsing burnup credit of actinide composition changes only; credit due to actinides encompasses approximately 30% of exiting pressurized water reactor SNF inventory and could potentially be increased to 90% if fission product credit were accepted. However, one significant issue for utilizing full burnup credit, compensating for actinide and fission product composition changes, is establishing a set of depletion parameters that produce an adequately conservative representation of the fuel's isotopic inventory. Depletion parameters can have a significant effect on the isotopic inventory of the fuel, and thus the residual reactivity. This research seeks to quantify the reactivity impact on a system from dominant depletion parameters (i.e., fuel temperature, moderator density, burnable poison rod, burnable poison rod history, and soluble boron concentration). Bounding depletion parameters were developed by statistical evaluation of a database containing reactor operating histories. The database was generated from summary reports of commercial reactor criticality data. Through depletion calculations, utilizing the SCALE 6 code package, several light water reactor assembly designs and in-core locations are analyzed in establishing a combination of depletion parameters that conservatively represent the fuel's isotopic inventory as an initiative to take credit for fuel burnup in criticality safety evaluations for transportation and storage of SNF.

Simulation study of gust alleviation in a tilt rotor aircraft, volume 1

NASA Technical Reports Server (NTRS)

Amos, A. K.; Alexander, H. R.

1977-01-01

The response to vertical turbulence in cruise of the HTR XV-15 design is studied using simulation techniques. This design is a modified version of the XV-15 with a hingeless fiberglass soft-in-plane rotor system. The parameters of a gust alleviation system are determined and the performance of the system is evaluated over a range of cruise velocities and altitudes.

[Personal emergency call system based on human vital and system technical parameters in a Smart Home environment].

PubMed

Hampicke, M; Schadow, B; Rossdeutscher, W; Fellbaum, K; Boenick, U

2002-11-01

Progress in microtechnology and radio transmission technology has enabled the development of highly reliable emergency-call systems. The present article describes systems that have been specially designed to improve the safety and independence of handicapped and elderly persons living at home. For such persons immediate help in an emergency situation is of crucial importance. The technical state of the art of emergency-call systems specially developed for use by the elderly, is briefly discussed, in particular the well-known radio emergency-call button, with the aid of which an alarm can be activated manually. This system, however, does not offer adequate safety in all emergency situations. Alternative or complementary systems designed to automatically trigger an alarm on the basis of the recording and evaluation of so-called vital parameters, are therefore proposed. In addition, in a smart-home environment with networked devices, further parameters--so-called environment parameters can be used. It is found that the identification of an emergency situation becomes more reliable as the number of parameters employed increases.

Design and Calibration of the X-33 Flush Airdata Sensing (FADS) System

NASA Technical Reports Server (NTRS)

Whitmore, Stephen A.; Cobleigh, Brent R.; Haering, Edward A.

1998-01-01

This paper presents the design of the X-33 Flush Airdata Sensing (FADS) system. The X-33 FADS uses a matrix of pressure orifices on the vehicle nose to estimate airdata parameters. The system is designed with dual-redundant measurement hardware, which produces two independent measurement paths. Airdata parameters that correspond to the measurement path with the minimum fit error are selected as the output values. This method enables a single sensor failure to occur with minimal degrading of the system performance. The paper shows the X-33 FADS architecture, derives the estimating algorithms, and demonstrates a mathematical analysis of the FADS system stability. Preliminary aerodynamic calibrations are also presented here. The calibration parameters, the position error coefficient (epsilon), and flow correction terms for the angle of attack (delta alpha), and angle of sideslip (delta beta) are derived from wind tunnel data. Statistical accuracy of' the calibration is evaluated by comparing the wind tunnel reference conditions to the airdata parameters estimated. This comparison is accomplished by applying the calibrated FADS algorithm to the sensed wind tunnel pressures. When the resulting accuracy estimates are compared to accuracy requirements for the X-33 airdata, the FADS system meets these requirements.

Experimental Assessment of the Hydraulics of a Miniature Axial-Flow Left Ventricular Assist Device

NASA Astrophysics Data System (ADS)

Smith, P. Alex; Cohn, William; Metcalfe, Ralph

2017-11-01

A minimally invasive partial-support left ventricular assist device (LVAD) has been proposed with a flow path from the left atrium to the arterial system to reduce left ventricular stroke work. In LVAD design, peak and average efficiency must be balanced over the operating range to reduce blood trauma. Axial flow pumps have many geometric parameters. Until recently, testing all these parameters was impractical, but modern 3D printing technology enables multi-parameter studies. Following theoretical design, experimental hydraulic evaluation in steady state conditions examines pressure, flow, pressure-flow gradient, efficiency, torque, and axial force as output parameters. Preliminary results suggest that impeller blades and stator vanes with higher inlet angles than recommended by mean line theory (MLT) produce flatter gradients and broader efficiency curves, increasing compatibility with heart physiology. These blades also produce less axial force, which reduces bearing load. However, they require slightly higher torque, which is more demanding of the motor. MLT is a low order, empirical model developed on large pumps. It does not account for the significant viscous losses in small pumps like LVADs. This emphasizes the importance of experimental testing for hydraulic design. Roderick D MacDonald Research Fund.

Development and evaluation of a predictive algorithm for telerobotic task complexity

NASA Technical Reports Server (NTRS)

Gernhardt, M. L.; Hunter, R. C.; Hedgecock, J. C.; Stephenson, A. G.

1993-01-01

There is a wide range of complexity in the various telerobotic servicing tasks performed in subsea, space, and hazardous material handling environments. Experience with telerobotic servicing has evolved into a knowledge base used to design tasks to be 'telerobot friendly.' This knowledge base generally resides in a small group of people. Written documentation and requirements are limited in conveying this knowledge base to serviceable equipment designers and are subject to misinterpretation. A mathematical model of task complexity based on measurable task parameters and telerobot performance characteristics would be a valuable tool to designers and operational planners. Oceaneering Space Systems and TRW have performed an independent research and development project to develop such a tool for telerobotic orbital replacement unit (ORU) exchange. This algorithm was developed to predict an ORU exchange degree of difficulty rating (based on the Cooper-Harper rating used to assess piloted operations). It is based on measurable parameters of the ORU, attachment receptacle and quantifiable telerobotic performance characteristics (e.g., link length, joint ranges, positional accuracy, tool lengths, number of cameras, and locations). The resulting algorithm can be used to predict task complexity as the ORU parameters, receptacle parameters, and telerobotic characteristics are varied.

Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

NASA Technical Reports Server (NTRS)

1981-01-01

The development of several types of graphite/polyimide (GR/PI) bonded and bolted joints is reported. The program consists of two concurrent tasks: (1) design and test of specific built up attachments; and (2) evaluation of standard advanced bonded joint concepts. A data base for the design and analysis of advanced composite joints for use at elevated temperatures (561K (550 deg F)) to design concepts for specific joining applications, and the fundamental parameters controlling the static strength characteristics of such joints are evaluated. Data for design and build GR/PI of lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Results for compression and interlaminar shear strengths of Celion 6000/PMR-15 laminates are given. Static discriminator test results for type 3 and type 4 bonded and bolted joints and final joint designs for TASK 1.4 scale up fabrication and testing are presented.

Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design.

PubMed

Ballarini, E; Bauer, S; Eberhardt, C; Beyer, C

2012-06-01

Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Application of a quality by design approach to the cell culture process of monoclonal antibody production, resulting in the establishment of a design space.

PubMed

Nagashima, Hiroaki; Watari, Akiko; Shinoda, Yasuharu; Okamoto, Hiroshi; Takuma, Shinya

2013-12-01

This case study describes the application of Quality by Design elements to the process of culturing Chinese hamster ovary cells in the production of a monoclonal antibody. All steps in the cell culture process and all process parameters in each step were identified by using a cause-and-effect diagram. Prospective risk assessment using failure mode and effects analysis identified the following four potential critical process parameters in the production culture step: initial viable cell density, culture duration, pH, and temperature. These parameters and lot-to-lot variability in raw material were then evaluated by process characterization utilizing a design of experiments approach consisting of a face-centered central composite design integrated with a full factorial design. Process characterization was conducted using a scaled down model that had been qualified by comparison with large-scale production data. Multivariate regression analysis was used to establish statistical prediction models for performance indicators and quality attributes; with these, we constructed contour plots and conducted Monte Carlo simulation to clarify the design space. The statistical analyses, especially for raw materials, identified set point values, which were most robust with respect to the lot-to-lot variability of raw materials while keeping the product quality within the acceptance criteria. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

Evaluation of design flood estimates with respect to sample size

NASA Astrophysics Data System (ADS)

Kobierska, Florian; Engeland, Kolbjorn

2016-04-01

Estimation of design floods forms the basis for hazard management related to flood risk and is a legal obligation when building infrastructure such as dams, bridges and roads close to water bodies. Flood inundation maps used for land use planning are also produced based on design flood estimates. In Norway, the current guidelines for design flood estimates give recommendations on which data, probability distribution, and method to use dependent on length of the local record. If less than 30 years of local data is available, an index flood approach is recommended where the local observations are used for estimating the index flood and regional data are used for estimating the growth curve. For 30-50 years of data, a 2 parameter distribution is recommended, and for more than 50 years of data, a 3 parameter distribution should be used. Many countries have national guidelines for flood frequency estimation, and recommended distributions include the log Pearson II, generalized logistic and generalized extreme value distributions. For estimating distribution parameters, ordinary and linear moments, maximum likelihood and Bayesian methods are used. The aim of this study is to r-evaluate the guidelines for local flood frequency estimation. In particular, we wanted to answer the following questions: (i) Which distribution gives the best fit to the data? (ii) Which estimation method provides the best fit to the data? (iii) Does the answer to (i) and (ii) depend on local data availability? To answer these questions we set up a test bench for local flood frequency analysis using data based cross-validation methods. The criteria were based on indices describing stability and reliability of design flood estimates. Stability is used as a criterion since design flood estimates should not excessively depend on the data sample. The reliability indices describe to which degree design flood predictions can be trusted.

Evaluation of rotor-bearing system dynamic response to unbalance. [air conditioning equipment

NASA Technical Reports Server (NTRS)

Thaller, R. E.; Ozimek, D. W.

1979-01-01

The vibration environment within air conditioner rotating machinery referred to as an air cycle machine (ACM) was investigated to effectively increase ACM reliability. To assist in the selection of design changes which would result in improved ACM performance, various design modifications were incorporated into a baseline ACM configuration. For each design change, testing was conducted with the best balance achieveable (baseline) and with various degrees of unbalance. Relationships between unbalance (within the context of design changes) and the parameters associated with design goals were established. The results of rotor dynamics tests used to establish these relationships are presented.

Quality-by-Design II: Application of Quantitative Risk Analysis to the Formulation of Ciprofloxacin Tablets.

PubMed

Claycamp, H Gregg; Kona, Ravikanth; Fahmy, Raafat; Hoag, Stephen W

2016-04-01

Qualitative risk assessment methods are often used as the first step to determining design space boundaries; however, quantitative assessments of risk with respect to the design space, i.e., calculating the probability of failure for a given severity, are needed to fully characterize design space boundaries. Quantitative risk assessment methods in design and operational spaces are a significant aid to evaluating proposed design space boundaries. The goal of this paper is to demonstrate a relatively simple strategy for design space definition using a simplified Bayesian Monte Carlo simulation. This paper builds on a previous paper that used failure mode and effects analysis (FMEA) qualitative risk assessment and Plackett-Burman design of experiments to identity the critical quality attributes. The results show that the sequential use of qualitative and quantitative risk assessments can focus the design of experiments on a reduced set of critical material and process parameters that determine a robust design space under conditions of limited laboratory experimentation. This approach provides a strategy by which the degree of risk associated with each known parameter can be calculated and allocates resources in a manner that manages risk to an acceptable level.

Evaluating an Online Resourcefulness Training Intervention Pilot Test Using Six Critical Parameters.

PubMed

Musil, Carol M; Zauszniewski, Jaclene A; Burant, Christopher J; Toly, Valerie B; Warner, Camille B

2015-12-01

Few resources are available to help grandmother caregivers to grandchildren manage their complex family situations that may have immediate and long-term consequences for themselves and their families. Resourcefulness training is an intervention designed to help grandmothers improve their ability to deal with these problems. The purpose of this pilot study was to evaluate the necessity, feasibility, acceptability, fidelity, safety, and effectiveness (i.e., effect sizes) of an online, computer-based resourcefulness training intervention that was adapted from a face-to-face intervention. Twelve grandmothers raising or living with grandchildren participated in the pilot intervention that included (a) watching an instructional video on resourcefulness, (b) completing two online questionnaires over a 6-week time period, and (c) writing in an online journal every day for 4 weeks. Data are evaluated within the context of the six parameters important to intervention development. Qualitative and quantitative results provide initial support for all six parameters. Recommendations to improve aspects of the intervention are discussed. © The Author(s) 2015.

Chance of Vulnerability Reduction in Application-Specific NoC through Distance Aware Mapping Algorithm

NASA Astrophysics Data System (ADS)

Janidarmian, Majid; Fekr, Atena Roshan; Bokharaei, Vahhab Samadi

2011-08-01

Mapping algorithm which means which core should be linked to which router is one of the key issues in the design flow of network-on-chip. To achieve an application-specific NoC design procedure that minimizes the communication cost and improves the fault tolerant property, first a heuristic mapping algorithm that produces a set of different mappings in a reasonable time is presented. This algorithm allows the designers to identify the set of most promising solutions in a large design space, which has low communication costs while yielding optimum communication costs in some cases. Another evaluated parameter, vulnerability index, is then considered as a principle of estimating the fault-tolerance property in all produced mappings. Finally, in order to yield a mapping which considers trade-offs between these two parameters, a linear function is defined and introduced. It is also observed that more flexibility to prioritize solutions within the design space is possible by adjusting a set of if-then rules in fuzzy logic.

Next Generation Ship-Borne ASW-System: An Exemplary Exertion of Methodologies and Tools Applied According to the German Military Acquisition Guidelines

DTIC Science & Technology

2013-06-01

as well as the evaluation of product parameters, operational test and functional limits. The product will be handed over to the designated ...which results in a system design that can be tested , produced, and fielded to satisfy the need. The concept development phase enables us to determine...specifications that can be tested or verified. The requirements presented earlier are the minimum necessary to allow the design process to find

Evaluation of two flap designs on the mandibular second molar after third molar extractions

PubMed Central

Alqahtani, Nabeeh A; Khaleelahmed, S; Desai, Farheen

2017-01-01

Background: The extraction of third molars is associated with some clinical outcomes and periodontal problems. It is imperative to note that the type of incision used in the surgery for the removal of the impacted third molar is critical. The design of the flap influences the healing of the surgically created defect and damage to the distal periodontal area of the adjacent second molar. However, till date, there have been conflicting reports on the influence of different flap designs used for the surgical removal of impacted third molars. Aim: The present study aimed to comparatively evaluate the clinical outcomes and periodontal status of the adjacent second molar, when two different flap designs, namely, the envelope and the modified triangular flap designs were used. Materials and Methods: Sixty female patients with bilateral impacted third molars completed the study with envelope flap on one side and modified triangular flap design on the other side of the mandible for third molar removal. Clinical parameters including pain, dehiscence and swelling were assessed postoperatively and periodontal probing depth (PPD) on the distal aspect of adjacent second molar were assessed both pre- and post-operatively. Results: The results were assessed on 1, 3 and 8 days for pain using visual analog scale. The subjective perception of swelling was evaluated on 3, 7 and 15 days postoperatively in a similar manner. The results of the periodontal parameters were evaluated both preoperatively and 3 months postoperatively, with cautious exploration using a University of North Carolina (UNC)-15 periodontal probe. The statistically significant results for swelling and PPD were noted for the two flap groups using the Chi-square test (P < 0.05). Conclusion: The study revealed that the modified triangular flap had lesser postoperative PPDs and dehiscence. The envelope flap was better when swelling was analyzed. The pain scores, though slightly higher for the modified triangular flap group, were not statistically significant. PMID:28932049

D-Optimal Experimental Design for Contaminant Source Identification

NASA Astrophysics Data System (ADS)

Sai Baba, A. K.; Alexanderian, A.

2016-12-01

Contaminant source identification seeks to estimate the release history of a conservative solute given point concentration measurements at some time after the release. This can be mathematically expressed as an inverse problem, with a linear observation operator or a parameter-to-observation map, which we tackle using a Bayesian approach. Acquisition of experimental data can be laborious and expensive. The goal is to control the experimental parameters - in our case, the sparsity of the sensors, to maximize the information gain subject to some physical or budget constraints. This is known as optimal experimental design (OED). D-optimal experimental design seeks to maximize the expected information gain, and has long been considered the gold standard in the statistics community. Our goal is to develop scalable methods for D-optimal experimental designs involving large-scale PDE constrained problems with high-dimensional parameter fields. A major challenge for the OED, is that a nonlinear optimization algorithm for the D-optimality criterion requires repeated evaluation of objective function and gradient involving the determinant of large and dense matrices - this cost can be prohibitively expensive for applications of interest. We propose novel randomized matrix techniques that bring down the computational costs of the objective function and gradient evaluations by several orders of magnitude compared to the naive approach. The effect of randomized estimators on the accuracy and the convergence of the optimization solver will be discussed. The features and benefits of our new approach will be demonstrated on a challenging model problem from contaminant source identification involving the inference of the initial condition from spatio-temporal observations in a time-dependent advection-diffusion problem.

Floor vibration evaluations for medical facilities

NASA Astrophysics Data System (ADS)

Himmel, Chad N.

2003-10-01

The structural floor design for new medical facilities is often selected early in the design phase and in renovation projects, the floor structure already exists. Because the floor structure can often have an influence on the location of vibration sensitive medical equipment and facilities, it is becoming necessary to identify the best locations for equipment and facilities early in the design process. Even though specific criteria for vibration-sensitive uses and equipment may not always be available early in the design phase, it should be possible to determine compatible floor structures for planned vibration-sensitive uses by comparing conceptual layouts with generic floor vibration criteria. Relatively simple evaluations of planned uses and generic criteria, combined with on-site vibration and noise measurements early in design phase, can significantly reduce future design problems and expense. Concepts of evaluation procedures and analyses will be presented in this paper. Generic floor vibration criteria and appropriate parameters to control resonant floor vibration and noise will be discussed for typical medical facilities and medical research facilities. Physical, economic, and logistical limitations that affect implementation will be discussed through case studies.

Uncertainty Analysis of Simulated Hydraulic Fracturing

NASA Astrophysics Data System (ADS)

Chen, M.; Sun, Y.; Fu, P.; Carrigan, C. R.; Lu, Z.

2012-12-01

Artificial hydraulic fracturing is being used widely to stimulate production of oil, natural gas, and geothermal reservoirs with low natural permeability. Optimization of field design and operation is limited by the incomplete characterization of the reservoir, as well as the complexity of hydrological and geomechanical processes that control the fracturing. Thus, there are a variety of uncertainties associated with the pre-existing fracture distribution, rock mechanics, and hydraulic-fracture engineering that require evaluation of their impact on the optimized design. In this study, a multiple-stage scheme was employed to evaluate the uncertainty. We first define the ranges and distributions of 11 input parameters that characterize the natural fracture topology, in situ stress, geomechanical behavior of the rock matrix and joint interfaces, and pumping operation, to cover a wide spectrum of potential conditions expected for a natural reservoir. These parameters were then sampled 1,000 times in an 11-dimensional parameter space constrained by the specified ranges using the Latin-hypercube method. These 1,000 parameter sets were fed into the fracture simulators, and the outputs were used to construct three designed objective functions, i.e. fracture density, opened fracture length and area density. Using PSUADE, three response surfaces (11-dimensional) of the objective functions were developed and global sensitivity was analyzed to identify the most sensitive parameters for the objective functions representing fracture connectivity, which are critical for sweep efficiency of the recovery process. The second-stage high resolution response surfaces were constructed with dimension reduced to the number of the most sensitive parameters. An additional response surface with respect to the objective function of the fractal dimension for fracture distributions was constructed in this stage. Based on these response surfaces, comprehensive uncertainty analyses were conducted among input parameters and objective functions. In addition, reduced-order emulation models resulting from this analysis can be used for optimal control of hydraulic fracturing. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Coupled neutronics and thermal-hydraulics numerical simulations of a Molten Fast Salt Reactor (MFSR)

NASA Astrophysics Data System (ADS)

Laureau, A.; Rubiolo, P. R.; Heuer, D.; Merle-Lucotte, E.; Brovchenko, M.

2014-06-01

Coupled neutronics and thermalhydraulic numerical analyses of a molten salt fast reactor are presented. These preliminary numerical simulations are carried-out using the Monte Carlo code MCNP and the Computation Fluid Dynamic code OpenFOAM. The main objectives of this analysis performed at steady-reactor conditions are to confirm the acceptability of the current neutronic and thermalhydraulic designs of the reactor, to study the effects of the reactor operating conditions on some of the key MSFR design parameters such as the temperature peaking factor. The effects of the precursor's motion on the reactor safety parameters such as the effective fraction of delayed neutrons have been evaluated.

Flight data processing with the F-8 adaptive algorithm

NASA Technical Reports Server (NTRS)

Hartmann, G.; Stein, G.; Petersen, K.

1977-01-01

An explicit adaptive control algorithm based on maximum likelihood estimation of parameters has been designed for NASA's DFBW F-8 aircraft. To avoid iterative calculations, the algorithm uses parallel channels of Kalman filters operating at fixed locations in parameter space. This algorithm has been implemented in NASA/DFRC's Remotely Augmented Vehicle (RAV) facility. Real-time sensor outputs (rate gyro, accelerometer and surface position) are telemetered to a ground computer which sends new gain values to an on-board system. Ground test data and flight records were used to establish design values of noise statistics and to verify the ground-based adaptive software. The software and its performance evaluation based on flight data are described

Comparison of information theoretic divergences for sensor management

NASA Astrophysics Data System (ADS)

Yang, Chun; Kadar, Ivan; Blasch, Erik; Bakich, Michael

2011-06-01

In this paper, we compare the information-theoretic metrics of the Kullback-Leibler (K-L) and Renyi (α) divergence formulations for sensor management. Information-theoretic metrics have been well suited for sensor management as they afford comparisons between distributions resulting from different types of sensors under different actions. The difference in distributions can also be measured as entropy formulations to discern the communication channel capacity (i.e., Shannon limit). In this paper, we formulate a sensor management scenario for target tracking and compare various metrics for performance evaluation as a function of the design parameter (α) so as to determine which measures might be appropriate for sensor management given the dynamics of the scenario and design parameter.

Design tradeoffs in long-term research for stream salamanders

USGS Publications Warehouse

Brand, Adrianne B,; Grant, Evan H. Campbell

2017-01-01

Long-term research programs can benefit from early and periodic evaluation of their ability to meet stated objectives. In particular, consideration of the spatial allocation of effort is key. We sampled 4 species of stream salamanders intensively for 2 years (2010–2011) in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA to evaluate alternative distributions of sampling locations within stream networks, and then evaluated via simulation the ability of multiple survey designs to detect declines in occupancy and to estimate dynamic parameters (colonization, extinction) over 5 years for 2 species. We expected that fine-scale microhabitat variables (e.g., cobble, detritus) would be the strongest determinants of occupancy for each of the 4 species; however, we found greater support for all species for models including variables describing position within the stream network, stream size, or stream microhabitat. A monitoring design focused on headwater sections had greater power to detect changes in occupancy and the dynamic parameters in each of 3 scenarios for the dusky salamander (Desmognathus fuscus) and red salamander (Pseudotriton ruber). Results for transect length were more variable, but across all species and scenarios, 25-m transects are most suitable as a balance between maximizing detection probability and describing colonization and extinction. These results inform sampling design and provide a general framework for setting appropriate goals, effort, and duration in the initial planning stages of research programs on stream salamanders in the eastern United States.

Taguchi Method Applied in Optimization of Shipley SJR 5740 Positive Resist Deposition

NASA Technical Reports Server (NTRS)

Hui, A.; Blosiu, J. O.; Wiberg, D. V.

1998-01-01

Taguchi Methods of Robust Design presents a way to optimize output process performance through an organized set of experiments by using orthogonal arrays. Analysis of variance and signal-to-noise ratio is used to evaluate the contribution of each of the process controllable parameters in the realization of the process optimization. In the photoresist deposition process, there are numerous controllable parameters that can affect the surface quality and thickness of the final photoresist layer.

Parameter sensitivity analysis of the mixed Green-Ampt/Curve-Number method for rainfall excess estimation in small ungauged catchments

NASA Astrophysics Data System (ADS)

Romano, N.; Petroselli, A.; Grimaldi, S.

2012-04-01

With the aim of combining the practical advantages of the Soil Conservation Service - Curve Number (SCS-CN) method and Green-Ampt (GA) infiltration model, we have developed a mixed procedure, which is referred to as CN4GA (Curve Number for Green-Ampt). The basic concept is that, for a given storm, the computed SCS-CN total net rainfall amount is used to calibrate the soil hydraulic conductivity parameter of the Green-Ampt model so as to distribute in time the information provided by the SCS-CN method. In a previous contribution, the proposed mixed procedure was evaluated on 100 observed events showing encouraging results. In this study, a sensitivity analysis is carried out to further explore the feasibility of applying the CN4GA tool in small ungauged catchments. The proposed mixed procedure constrains the GA model with boundary and initial conditions so that the GA soil hydraulic parameters are expected to be insensitive toward the net hyetograph peak. To verify and evaluate this behaviour, synthetic design hyetograph and synthetic rainfall time series are selected and used in a Monte Carlo analysis. The results are encouraging and confirm that the parameter variability makes the proposed method an appropriate tool for hydrologic predictions in ungauged catchments. Keywords: SCS-CN method, Green-Ampt method, rainfall excess, ungauged basins, design hydrograph, rainfall-runoff modelling.

Grey Relational Analysis Coupled with Principal Component Analysis for Optimization of Stereolithography Process to Enhance Part Quality

NASA Astrophysics Data System (ADS)

Raju, B. S.; Sekhar, U. Chandra; Drakshayani, D. N.

2017-08-01

The paper investigates optimization of stereolithography process for SL5530 epoxy resin material to enhance part quality. The major characteristics indexed for performance selected to evaluate the processes are tensile strength, Flexural strength, Impact strength and Density analysis and corresponding process parameters are Layer thickness, Orientation and Hatch spacing. In this study, the process is intrinsically with multiple parameters tuning so that grey relational analysis which uses grey relational grade as performance index is specially adopted to determine the optimal combination of process parameters. Moreover, the principal component analysis is applied to evaluate the weighting values corresponding to various performance characteristics so that their relative importance can be properly and objectively desired. The results of confirmation experiments reveal that grey relational analysis coupled with principal component analysis can effectively acquire the optimal combination of process parameters. Hence, this confirm that the proposed approach in this study can be an useful tool to improve the process parameters in stereolithography process, which is very useful information for machine designers as well as RP machine users.

Simulation and Flight Evaluation of a Parameter Estimation Input Design Method for Hybrid-Wing-Body Aircraft

NASA Technical Reports Server (NTRS)

Taylor, Brian R.; Ratnayake, Nalin A.

2010-01-01

As part of an effort to improve emissions, noise, and performance of next generation aircraft, it is expected that future aircraft will make use of distributed, multi-objective control effectors in a closed-loop flight control system. Correlation challenges associated with parameter estimation will arise with this expected aircraft configuration. Research presented in this paper focuses on addressing the correlation problem with an appropriate input design technique and validating this technique through simulation and flight test of the X-48B aircraft. The X-48B aircraft is an 8.5 percent-scale hybrid wing body aircraft demonstrator designed by The Boeing Company (Chicago, Illinois, USA), built by Cranfield Aerospace Limited (Cranfield, Bedford, United Kingdom) and flight tested at the National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California, USA). Based on data from flight test maneuvers performed at Dryden Flight Research Center, aerodynamic parameter estimation was performed using linear regression and output error techniques. An input design technique that uses temporal separation for de-correlation of control surfaces is proposed, and simulation and flight test results are compared with the aerodynamic database. This paper will present a method to determine individual control surface aerodynamic derivatives.

Methods for comparative evaluation of propulsion system designs for supersonic aircraft

NASA Technical Reports Server (NTRS)

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

1976-01-01

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

RACLETTE: a model for evaluating the thermal response of plasma facing components to slow high power plasma transients. Part II: Analysis of ITER plasma facing components

NASA Astrophysics Data System (ADS)

Federici, Gianfranco; Raffray, A. René

1997-04-01

The transient thermal model RACLETTE (acronym of Rate Analysis Code for pLasma Energy Transfer Transient Evaluation) described in part I of this paper is applied here to analyse the heat transfer and erosion effects of various slow (100 ms-10 s) high power energy transients on the actively cooled plasma facing components (PFCs) of the International Thermonuclear Experimental Reactor (ITER). These have a strong bearing on the PFC design and need careful analysis. The relevant parameters affecting the heat transfer during the plasma excursions are established. The temperature variation with time and space is evaluated together with the extent of vaporisation and melting (the latter only for metals) for the different candidate armour materials considered for the design (i.e., Be for the primary first wall, Be and CFCs for the limiter, Be, W, and CFCs for the divertor plates) and including for certain cases low-density vapour shielding effects. The critical heat flux, the change of the coolant parameters and the possible severe degradation of the coolant heat removal capability that could result under certain conditions during these transients, for example for the limiter, are also evaluated. Based on the results, the design implications on the heat removal performance and erosion damage of the variuos ITER PFCs are critically discussed and some recommendations are made for the selection of the most adequate protection materials and optimum armour thickness.

Optimizing RF gun cavity geometry within an automated injector design system

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

Alicia Hofler ,Pavel Evtushenko

2011-03-28

RF guns play an integral role in the success of several light sources around the world, and properly designed and optimized cw superconducting RF (SRF) guns can provide a path to higher average brightness. As the need for these guns grows, it is important to have automated optimization software tools that vary the geometry of the gun cavity as part of the injector design process. This will allow designers to improve existing designs for present installations, extend the utility of these guns to other applications, and develop new designs. An evolutionary algorithm (EA) based system can provide this capability becausemore » EAs can search in parallel a large parameter space (often non-linear) and in a relatively short time identify promising regions of the space for more careful consideration. The injector designer can then evaluate more cavity design parameters during the injector optimization process against the beam performance requirements of the injector. This paper will describe an extension to the APISA software that allows the cavity geometry to be modified as part of the injector optimization and provide examples of its application to existing RF and SRF gun designs.« less

Deep ocean corrosion research in support of Oman India gas pipeline

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

Graham, F.W.; McKeehan, D.S.

1995-12-01

The increasing interest in deepwater exploration and production has motivated the development of technologies required to accomplish tasks heretofore possible only onshore and in shallow water. The tremendous expense of technology development and the cost of specialized equipment has created concerns that the design life of these facilities may be compromised by corrosion. The requirements to develop and prove design parameters to meet these demands will require an ongoing environmental testing and materials evaluation and development program. This paper describes a two-fold corrosion testing program involving: (1) the installation of two corrosion test devices installed in-situ, and (2) a laboratorymore » test conducted in simulated site-specific seawater. These tests are expected to qualify key parameters necessary to design a cathodic protection system to protect the Oman-to-India pipeline.« less

Improving alignment in Tract-based spatial statistics: evaluation and optimization of image registration.

PubMed

de Groot, Marius; Vernooij, Meike W; Klein, Stefan; Ikram, M Arfan; Vos, Frans M; Smith, Stephen M; Niessen, Wiro J; Andersson, Jesper L R

2013-08-01

Anatomical alignment in neuroimaging studies is of such importance that considerable effort is put into improving the registration used to establish spatial correspondence. Tract-based spatial statistics (TBSS) is a popular method for comparing diffusion characteristics across subjects. TBSS establishes spatial correspondence using a combination of nonlinear registration and a "skeleton projection" that may break topological consistency of the transformed brain images. We therefore investigated feasibility of replacing the two-stage registration-projection procedure in TBSS with a single, regularized, high-dimensional registration. To optimize registration parameters and to evaluate registration performance in diffusion MRI, we designed an evaluation framework that uses native space probabilistic tractography for 23 white matter tracts, and quantifies tract similarity across subjects in standard space. We optimized parameters for two registration algorithms on two diffusion datasets of different quality. We investigated reproducibility of the evaluation framework, and of the optimized registration algorithms. Next, we compared registration performance of the regularized registration methods and TBSS. Finally, feasibility and effect of incorporating the improved registration in TBSS were evaluated in an example study. The evaluation framework was highly reproducible for both algorithms (R(2) 0.993; 0.931). The optimal registration parameters depended on the quality of the dataset in a graded and predictable manner. At optimal parameters, both algorithms outperformed the registration of TBSS, showing feasibility of adopting such approaches in TBSS. This was further confirmed in the example experiment. Copyright © 2013 Elsevier Inc. All rights reserved.

Scenarios and performance measures for advanced ISDN satellite design and experiments

NASA Technical Reports Server (NTRS)

Pepin, Gerard R.

1991-01-01

Described here are the contemplated input and expected output for the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and Full Service ISDN Satellite (FSIS) Models. The discrete event simulations of these models are presented with specific scenarios that stress ISDN satellite parameters. Performance measure criteria are presented for evaluating the advanced ISDN communication satellite designs of the NASA Satellite Communications Research (SCAR) Program.

Material Stream Strategy for Lithium and Inorganics (U)

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

Safarik, Douglas Joseph; Dunn, Paul Stanton; Korzekwa, Deniece Rochelle

Design Agency Responsibilities: Manufacturing Support to meet Stockpile Stewardship goals for maintaining the nuclear stockpile through experimental and predictive modeling capability. Development and maintenance of Manufacturing Science expertise to assess material specifications and performance boundaries, and their relationship to processing parameters. Production Engineering Evaluations with competence in design requirements, material specifications, and manufacturing controls. Maintenance and enhancement of Aging Science expertise to support Stockpile Stewardship predictive science capability.

HPLC-MS/MS method for dexmedetomidine quantification with Design of Experiments approach: application to pediatric pharmacokinetic study.

PubMed

Szerkus, Oliwia; Struck-Lewicka, Wiktoria; Kordalewska, Marta; Bartosińska, Ewa; Bujak, Renata; Borsuk, Agnieszka; Bienert, Agnieszka; Bartkowska-Śniatkowska, Alicja; Warzybok, Justyna; Wiczling, Paweł; Nasal, Antoni; Kaliszan, Roman; Markuszewski, Michał Jan; Siluk, Danuta

2017-02-01

The purpose of this work was to develop and validate a rapid and robust LC-MS/MS method for the determination of dexmedetomidine (DEX) in plasma, suitable for analysis of a large number of samples. Systematic approach, Design of Experiments, was applied to optimize ESI source parameters and to evaluate method robustness, therefore, a rapid, stable and cost-effective assay was developed. The method was validated according to US FDA guidelines. LLOQ was determined at 5 pg/ml. The assay was linear over the examined concentration range (5-2500 pg/ml), Results: Experimental design approach was applied for optimization of ESI source parameters and evaluation of method robustness. The method was validated according to the US FDA guidelines. LLOQ was determined at 5 pg/ml. The assay was linear over the examined concentration range (R 2 > 0.98). The accuracies, intra- and interday precisions were less than 15%. The stability data confirmed reliable behavior of DEX under tested conditions. Application of Design of Experiments approach allowed for fast and efficient analytical method development and validation as well as for reduced usage of chemicals necessary for regular method optimization. The proposed technique was applied to determination of DEX pharmacokinetics in pediatric patients undergoing long-term sedation in the intensive care unit.

Quality by design approach for viral clearance by protein a chromatography

PubMed Central

Zhang, Min; Miesegaes, George R; Lee, Michael; Coleman, Daniel; Yang, Bin; Trexler-Schmidt, Melody; Norling, Lenore; Lester, Philip; Brorson, Kurt A; Chen, Qi

2014-01-01

Protein A chromatography is widely used as a capture step in monoclonal antibody (mAb) purification processes. Antibodies and Fc fusion proteins can be efficiently purified from the majority of other complex components in harvested cell culture fluid (HCCF). Protein A chromatography is also capable of removing modest levels of viruses and is often validated for viral clearance. Historical data mining of Genentech and FDA/CDER databases systematically evaluated the removal of model viruses by Protein A chromatography. First, we found that for each model virus, removal by Protein A chromatography varies significantly across mAbs, while remains consistent within a specific mAb product, even across the acceptable ranges of the process parameters. In addition, our analysis revealed a correlation between retrovirus and parvovirus removal, with retrovirus data generally possessing a greater clearance factor. Finally, we describe a multivariate approach used to evaluate process parameter impacts on viral clearance, based on the levels of retrovirus-like particles (RVLP) present among process characterization study samples. It was shown that RVLP removal by Protein A is robust, that is, parameter effects were not observed across the ranges tested. Robustness of RVLP removal by Protein A also correlates with that for other model viruses such as X-MuLV, MMV, and SV40. The data supports that evaluating RVLP removal using process characterization study samples can establish multivariate acceptable ranges for virus removal by the protein A step for QbD. By measuring RVLP instead of a model retrovirus, it may alleviate some of the technical and economic challenges associated with performing large, design-of-experiment (DoE)—type virus spiking studies. This approach could also serve to provide useful insight when designing strategies to ensure viral safety in the manufacturing of a biopharmaceutical product. PMID:23860745

A designed experiment in stitched/RTM composites

NASA Technical Reports Server (NTRS)

Dickinson, Larry C.

1993-01-01

The damage tolerance of composite laminates can be significantly improved by the addition of through-the-thickness fibrous reinforcement such as stitching. However, there are numerous stitching parameters which can be independently varied, and their separate and combined effects on mechanical properties need to be determined. A statistically designed experiment (a 2(sup 5-1) fractional factorial, also known as a Taguchi L16 test matrix) used to evaluate five important parameters is described. The effects and interactions of stitch thread material, stitch thread strength, stitch row spacing and stitch pitch are examined for both thick (48 ply) and thin (16 ply) carbon/epoxy (AS4/E905L) composites. Tension, compression and compression after impact tests are described. Preliminary results of completed tension testing are discussed. Larger threads decreased tensile strength. Panel thickness was found not to be an important stitching parameter for tensile properties. Tensile modulus was unaffected by stitching.

[Optimization of succinic acid fermentation with Actinobacillus succinogenes by response surface methodology].

PubMed

Shen, Naikun; Qin, Yan; Wang, Qingyan; Xie, Nengzhong; Mi, Huizhi; Zhu, Qixia; Liao, Siming; Huang, Ribo

2013-10-01

Succinic acid is an important C4 platform chemical in the synthesis of many commodity and special chemicals. In the present work, different compounds were evaluated for succinic acid production by Actinobacillus succinogenes GXAS 137. Important parameters were screened by the single factor experiment and Plackeet-Burman design. Subsequently, the highest production of succinic acid was approached by the path of steepest ascent. Then, the optimum values of the parameters were obtained by Box-Behnken design. The results show that the important parameters were glucose, yeast extract and MgCO3 concentrations. The optimum condition was as follows (g/L): glucose 70.00, yeast extract 9.20 and MgCO3 58.10. Succinic acid yield reached 47.64 g/L at the optimal condition. Succinic acid increased by 29.14% than that before the optimization (36.89 g/L). Response surface methodology was proven to be a powerful tool to optimize succinic acid production.

Design of multi-energy Helds coupling testing system of vertical axis wind power system

NASA Astrophysics Data System (ADS)

Chen, Q.; Yang, Z. X.; Li, G. S.; Song, L.; Ma, C.

2016-08-01

The conversion efficiency of wind energy is the focus of researches and concerns as one of the renewable energy. The present methods of enhancing the conversion efficiency are mostly improving the wind rotor structure, optimizing the generator parameters and energy storage controller and so on. Because the conversion process involves in energy conversion of multi-energy fields such as wind energy, mechanical energy and electrical energy, the coupling effect between them will influence the overall conversion efficiency. In this paper, using system integration analysis technology, a testing system based on multi-energy field coupling (MEFC) of vertical axis wind power system is proposed. When the maximum efficiency of wind rotor is satisfied, it can match to the generator function parameters according to the output performance of wind rotor. The voltage controller can transform the unstable electric power to the battery on the basis of optimizing the parameters such as charging times, charging voltage. Through the communication connection and regulation of the upper computer system (UCS), it can make the coupling parameters configure to an optimal state, and it improves the overall conversion efficiency. This method can test the whole wind turbine (WT) performance systematically and evaluate the design parameters effectively. It not only provides a testing method for system structure design and parameter optimization of wind rotor, generator and voltage controller, but also provides a new testing method for the whole performance optimization of vertical axis wind energy conversion system (WECS).

Comparison of Mann-Kendall and innovative trend method for water quality parameters of the Kizilirmak River, Turkey

NASA Astrophysics Data System (ADS)

Kisi, Ozgur; Ay, Murat

2014-05-01

Low, medium and high values of a parameter are very important issues in climatological, meteorological and hydrological events. Moreover these values are used to decide various design parameters based on scientific aspects and real applications everywhere in the world. With this concept, a new trend method recently proposed by Şen was used for water parameters, pH, T, EC, Na+, K+, CO3-2, HCO3-, Cl-, SO4-2, B+3 and Q recorded at five different stations (station numbers and locations: 1535-Sogutluhan (Sivas), 1501-Yamula (Kayseri), 1546-Tuzkoy (Kayseri), 1503-Yahsihan (Kirsehir), and 1533-Inozu (Samsun)) selected from the Kizilirmak River in Turkey. Low, medium and high values of the parameters were graphically evaluated with this method. For comparison purposes, the Mann-Kendall trend test was also applied to the same data. Differences of the two trend tests were also emphasised. It was found that the Şen trend test compared with the MK trend test had several advantages. The results also revealed that the Şen trend test could be successfully used for trend analysis of water parameters especially in terms of evaluation of low, medium and high values of data.

Workflow for Criticality Assessment Applied in Biopharmaceutical Process Validation Stage 1.

PubMed

Zahel, Thomas; Marschall, Lukas; Abad, Sandra; Vasilieva, Elena; Maurer, Daniel; Mueller, Eric M; Murphy, Patrick; Natschläger, Thomas; Brocard, Cécile; Reinisch, Daniela; Sagmeister, Patrick; Herwig, Christoph

2017-10-12

Identification of critical process parameters that impact product quality is a central task during regulatory requested process validation. Commonly, this is done via design of experiments and identification of parameters significantly impacting product quality (rejection of the null hypothesis that the effect equals 0). However, parameters which show a large uncertainty and might result in an undesirable product quality limit critical to the product, may be missed. This might occur during the evaluation of experiments since residual/un-modelled variance in the experiments is larger than expected a priori. Estimation of such a risk is the task of the presented novel retrospective power analysis permutation test. This is evaluated using a data set for two unit operations established during characterization of a biopharmaceutical process in industry. The results show that, for one unit operation, the observed variance in the experiments is much larger than expected a priori, resulting in low power levels for all non-significant parameters. Moreover, we present a workflow of how to mitigate the risk associated with overlooked parameter effects. This enables a statistically sound identification of critical process parameters. The developed workflow will substantially support industry in delivering constant product quality, reduce process variance and increase patient safety.

Population models for passerine birds: structure, parameterization, and analysis

USGS Publications Warehouse

Noon, B.R.; Sauer, J.R.; McCullough, D.R.; Barrett, R.H.

1992-01-01

Population models have great potential as management tools, as they use infonnation about the life history of a species to summarize estimates of fecundity and survival into a description of population change. Models provide a framework for projecting future populations, determining the effects of management decisions on future population dynamics, evaluating extinction probabilities, and addressing a variety of questions of ecological and evolutionary interest. Even when insufficient information exists to allow complete identification of the model, the modelling procedure is useful because it forces the investigator to consider the life history of the species when determining what parameters should be estimated from field studies and provides a context for evaluating the relative importance of demographic parameters. Models have been little used in the study of the population dynamics of passerine birds because of: (1) widespread misunderstandings of the model structures and parameterizations, (2) a lack of knowledge of life histories of many species, (3) difficulties in obtaining statistically reliable estimates of demographic parameters for most passerine species, and (4) confusion about functional relationships among demographic parameters. As a result, studies of passerine demography are often designed inappropriately and fail to provide essential data. We review appropriate models for passerine bird populations and illustrate their possible uses in evaluating the effects of management or other environmental influences on population dynamics. We identify environmental influences on population dynamics. We identify parameters that must be estimated from field data, briefly review existing statistical methods for obtaining valid estimates, and evaluate the present status of knowledge of these parameters.

Slice simulation from a model of the parenchymous vascularization to evaluate texture features: work in progress.

PubMed

Rolland, Y; Bézy-Wendling, J; Duvauferrier, R; Coatrieux, J L

1999-03-01

To demonstrate the usefulness of a model of the parenchymous vascularization to evaluate texture analysis methods. Slices with thickness varying from 1 to 4 mm were reformatted from a 3D vascular model corresponding to either normal tissue perfusion or local hypervascularization. Parameters of statistical methods were measured on 16128x128 regions of interest, and mean values and standard deviation were calculated. For each parameter, the performances (discrimination power and stability) were evaluated. Among 11 calculated statistical parameters, three (homogeneity, entropy, mean of gradients) were found to have a good discriminating power to differentiate normal perfusion from hypervascularization, but only the gradient mean was found to have a good stability with respect to the thickness. Five parameters (run percentage, run length distribution, long run emphasis, contrast, and gray level distribution) were found to have intermediate results. In the remaining three, curtosis and correlation was found to have little discrimination power, skewness none. This 3D vascular model, which allows the generation of various examples of vascular textures, is a powerful tool to assess the performance of texture analysis methods. This improves our knowledge of the methods and should contribute to their a priori choice when designing clinical studies.

Product modular design incorporating preventive maintenance issues

NASA Astrophysics Data System (ADS)

Gao, Yicong; Feng, Yixiong; Tan, Jianrong

2016-03-01

Traditional modular design methods lead to product maintenance problems, because the module form of a system is created according to either the function requirements or the manufacturing considerations. For solving these problems, a new modular design method is proposed with the considerations of not only the traditional function related attributes, but also the maintenance related ones. First, modularity parameters and modularity scenarios for product modularity are defined. Then the reliability and economic assessment models of product modularity strategies are formulated with the introduction of the effective working age of modules. A mathematical model used to evaluate the difference among the modules of the product so that the optimal module of the product can be established. After that, a multi-objective optimization problem based on metrics for preventive maintenance interval different degrees and preventive maintenance economics is formulated for modular optimization. Multi-objective GA is utilized to rapidly approximate the Pareto set of optimal modularity strategy trade-offs between preventive maintenance cost and preventive maintenance interval difference degree. Finally, a coordinate CNC boring machine is adopted to depict the process of product modularity. In addition, two factorial design experiments based on the modularity parameters are constructed and analyzed. These experiments investigate the impacts of these parameters on the optimal modularity strategies and the structure of module. The research proposes a new modular design method, which may help to improve the maintainability of product in modular design.

Digital frequency synthesizer for radar astronomy

NASA Technical Reports Server (NTRS)

Sadr, R.; Satorius, E.; Robinett, L.; Olson, E.

1990-01-01

The digital frequency synthesizer (DFS) is an integral part of the programmable local oscillator (PLO) which is being developed for the NASA's Deep Space Network (DSN) and radar astronomy. Here, the theory of operation and the design of the DFS are discussed, and the design parameters in application for the Goldstone Solar System Radar (GSSR) are specified. The spectral purity of the DFS is evaluated by analytically evaluating the output spectrum of the DFS. A novel architecture is proposed for the design of the DFS with a frequency resolution of 1/2(exp 48) of the clock frequency (0.35 mu Hz at 100 MHz), a phase resolution of 0.0056 degrees (16 bits), and a frequency spur attenuation of -96 dBc.

Optimization of thiamethoxam adsorption parameters using multi-walled carbon nanotubes by means of fractional factorial design.

PubMed

Panić, Sanja; Rakić, Dušan; Guzsvány, Valéria; Kiss, Erne; Boskovic, Goran; Kónya, Zoltán; Kukovecz, Ákos

2015-12-01

The aim of this work was to evaluate significant factors affecting the thiamethoxam adsorption efficiency using oxidized multi-walled carbon nanotubes (MWCNTs) as adsorbents. Five factors (initial solution concentration of thiamethoxam in water, temperature, solution pH, MWCNTs weight and contact time) were investigated using 2V(5-1) fractional factorial design. The obtained linear model was statistically tested using analysis of variance (ANOVA) and the analysis of residuals was used to investigate the model validity. It was observed that the factors and their second-order interactions affecting the thiamethoxam removal can be divided into three groups: very important, moderately important and insignificant ones. The initial solution concentration was found to be the most influencing parameter on thiamethoxam adsorption from water. Optimization of the factors levels was carried out by minimizing those parameters which are usually critical in real life: the temperature (energy), contact time (money) and weight of MWCNTs (potential health hazard), in order to maximize the adsorbed amount of the pollutant. The results of maximal adsorbed thiamethoxam amount in both real and optimized experiments indicate that among minimized parameters the adsorption time is one that makes the largest difference. The results of this study indicate that fractional factorial design is very useful tool for screening the higher number of parameters and reducing the number of adsorption experiments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechanical Analog Approach to Parameter Estimation of Lateral Spacecraft Fuel Slosh

NASA Technical Reports Server (NTRS)

Chatman, Yadira; Gangadharan, Sathya; Schlee, Keith; Sudermann, James; Walker, Charles; Ristow, James; Hubert, Carl

2007-01-01

The nutation (wobble) of a spinning spacecraft in the presence of energy dissipation is a well-known problem in dynamics and is of particular concern for space missions. Even with modern computing systems, CFD type simulations are not fast enough to allow for large scale Monte Carlo analyses of spacecraft and launch vehicle dynamic behavior with slosh included. Simplified mechanical analogs for the slosh are preferred during the initial stages of design to reduce computational time and effort to evaluate the Nutation Time Constant (NTC). Analytic determination of the slosh analog parameters has met with mixed success and is made even more difficult by the introduction of propellant management devices such as elastomeric diaphragms. By subjecting full-sized fuel tanks with actual flight fuel loads to motion similar to that experienced in flight and measuring the forces experienced by the tanks, these parameters can be determined experimentally. Currently, the identification of the model parameters is a laborious trial-and-error process in which the hand-derived equations of motion for the mechanical analog are evaluated and their results compared with the experimental results. Of particular interest is the effect of diaphragms and bladders on the slosh dynamics and how best to model these devices. An experimental set-up is designed and built to include a diaphragm in the simulated spacecraft fuel tank subjected to lateral slosh. This research paper focuses on the parameter estimation of a SimMechanics model of the simulated spacecraft propellant tank with and without diaphragms using lateral fuel slosh experiments. Automating the parameter identification process will save time and thus allow earlier identification of potential vehicle problems.

Control Method Stretches Suspensions by Measuring the Sag of Strands in Cable-Stayed Bridges

NASA Astrophysics Data System (ADS)

Bętkowski, Piotr

2017-10-01

In the article is described the method that allows on evaluation and validation of measurement correctness of dynamometers (strain gauges, tension meters) used in systems of suspensions. Control of monitoring devices such as dynamometers is recommended in inspections of suspension bridges. Control device (dynamometer) works with an anchor, and the degree of this cooperation could have a decisive impact on the correctness of the results. Method, which determines the stress in the strand (cable), depending on the sag of stayed cable, is described. This method can be used to control the accuracy of measuring devices directly on the bridge. By measuring the strand sag, it is possible to obtain information about the strength (force) which occurred in the suspension cable. Digital camera is used for the measurement of cable sag. Control measurement should be made independently from the controlled parameter but should verify this parameter directly (it is the best situation). In many cases in practice the controlled parameter is not designation by direct measurement, but the calculations, i.e. relation measured others parameters, as in the method described in the article. In such cases occurred the problem of overlapping error of measurement of intermediate parameters (data) and the evaluation of the reliability of the results. Method of control calculations made in relation to installed in the bridge measuring devices is doubtful without procedure of uncertainty estimation. Such an assessment of the accuracy can be performed using the interval numbers. With the interval numbers are possible the analysis of parametric relationship accuracy of the designation of individual parameters and uncertainty of results. Method of measurements, relations and analytical formulas, and numerical example can be found in the text of the article.

Loads and performance data from a wind-tunnel test of model articulated helicopter rotors with 2 different blade torsional stiffnesses

NASA Technical Reports Server (NTRS)

Yeager, W. T., Jr.; Mantay, W. R.

1983-01-01

A passive means of tailoring helicopter rotor blades to improve performance and reduce loads was evaluated. The parameters investigated were blade torsional stiffness, blade section camber, and distance between blade structural elastic axis and blade tip aerodynamic center. This offset was accomplished by sweeping the tip. The investigation was conducted at advance ratios of 0.20, 0.30, and 0.40. Data are presented without analysis; however, cross referencing of performance data and harmonic loads data may be useful to the analyst for validating aeroelastic theories and design methodologies as well as for evaluating passive aeroelastic tailoring or rotor blade parameters.

Vehicle performance evaluation in side impact (MDB) using ES-II dummy

NASA Astrophysics Data System (ADS)

Ganessh, T. S.; Bansode, Praveen; Revankar, Vidyakant; Kumar, Sunil

2018-02-01

Side impact collision is one of the leading causes of death. Protection of people during lateral collision is challenging because of relatively small space available to restraint occupant compared to front. Hence, it is imperative to protect the occupants in side collision. It is a function of vehicle type and restraints for side protection. This paper focuses on evaluation of injury parameters of the ES II dummy during the lateral collision of different vehicles with different spaces, sections and materials. Thus the comparison will enable us to understand the sensitivity of space, B-pillar section and material which affects the injury parameters. This study will help automotive engineers to design side impact crashworthy vehicles.

Measurements of female genital appearance in Chinese adults seeking genital cosmetic surgery: a preliminary report from a gynecological center.

PubMed

Cao, Yujiao; Li, Qiang; Zhou, Chuande; Li, Fengyong; Li, Senkai; Zhou, Yu

2015-05-01

Accurate and comprehensive measurements of the external genitalia in female adults are of great significance in surgery designs and for aesthetic evaluation in genital plastic surgeries. The authors carried out a 319-case study and provided baseline data and morphometric reference for plastic surgery involving the genital deformity caused by trauma or burns and male-to-female transsexual operations. Our study design recruited 319 women referred to the out-patient clinic from August 2010 to August 2013. From each individual we measured 16 parameters and assessed the significance of variations in age, height, weight, BMI, and marital status (as a proxy for parity). We tried to establish a female external genitalia database of the population presenting for cosmetic surgery and define the general proportions of female genitalia in Chinese adults from the data we obtained. A wide range of values was noted in female genital measurements especially in labia minora parameters. Four parameters, including clitoral prepuce length, clitoris to urethra, labial length, and perineal body length had a proportional relationship to some extent. The position of the clitoris and urethral orifice was found to be regular in female adults. Compared with unmarried women, perineal body length decreased (P = 0.048), while the apex to perineum (bilateral) and labial length increased (P = 0.005, 0.006, <0.0001) in those who were married. Several parameters were statistically significantly associated with age, height, weight, BMI, and marital status. We presented an external genitalia database of Chinese female adults asking for cosmetic surgery. Although the ranges of genital measurements vary, there is a proportional relationship in female genital appearance, which should be heeded in surgical designs and genital aesthetic evaluation.

Physicochemical, nutritional and infrared spectroscopy evaluation of an optimized soybean/corn flour extrudate

USDA-ARS?s Scientific Manuscript database

A central composite design using RMS successfully described the effect of independent variables (feed moisture, die temperature and soybean proportion) on the specific parameters of product quality (expansion index, water absorption index, water solubility index and total color difference) studied. ...

Estimating the Variance of Design Parameters

ERIC Educational Resources Information Center

Hedberg, E. C.; Hedges, L. V.; Kuyper, A. M.

2015-01-01

Randomized experiments are generally considered to provide the strongest basis for causal inferences about cause and effect. Consequently randomized field trials have been increasingly used to evaluate the effects of education interventions, products, and services. Populations of interest in education are often hierarchically structured (such as…

14 CFR 1215.108 - Defining user service requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Defining user service requirements. 1215.108 Section 1215.108 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA..., spacecraft design, operations planning, and other significant mission parameters. When these user evaluations...

Drilled shaft bridge foundation design parameters and procedures for bearing in SGC soils.

DOT National Transportation Integrated Search

2006-04-01

This report provides a simplified method to be used for evaluating the skin friction and tip resistance of : axially loaded drilled shafts. A summary of literature and current practice was completed and then a : comprehensive set of field and laborat...

Comparison of growth curve parameters of organs and body components in meat- (Coturnix coturnix coturnix) and laying-type (Coturnix coturnix japonica) quail show interactions between gender and genotype.

PubMed

Grieser, D O; Marcato, S M; Furlan, A C; Zancanela, V; Ton, A P S; Batista, E; Perine, T P; Pozza, P C; Sakomura, N K

2015-01-01

1. The objective of this study was to estimate growth parameters of carcass components (wing, thighs and drumsticks, back and breast) and organs (heart, liver, gizzard and gut) in males and females of one meat-type quail strain (Coturnix coturnix coturnix) and two laying strains (Coturnix coturnix japonica) designated either yellow or red. 2. A total of 1350 quail from 1 to 42 d old were distributed in a completely randomised design, with 5 replicates of each strain. The carcass component weights and body organs were analysed weekly and evaluated using the Gompertz function; growth rates were evaluated through derivative equations. 3. The meat-type strain presented the highest growth rates in carcass components and organs. Across strains, females showed the highest weight of internal organs at maturity compared to males. 4. Females had greater growth potential in breast, wings and back than males for both yellow and red laying quail.

Evaluation of Dry, Rough Vacuum Pumps

NASA Technical Reports Server (NTRS)

Hunter, Brian

2006-01-01

This document provides information on the testing and evaluation of thirteen dry rough vacuum pumps of various designs and from various manufacturers. Several types of rough vacuum pumps were evaluated, including scroll, roots, and diaphragm pumps. Tests included long term testing, speed curve generation, voltage variance, vibrations emissions and susceptibility, electromagnetic interference emissions and susceptibility, static leak rate, exhaust restriction, response/recovery time tests, and a contamination analysis for scroll pumps. Parameters were found for operation with helium, which often is not provided from the manufacturer

Sediment transport modeling in deposited bed sewers: unified form of May's equations using the particle swarm optimization algorithm.

PubMed

Safari, Mir Jafar Sadegh; Shirzad, Akbar; Mohammadi, Mirali

2017-08-01

May proposed two dimensionless parameters of transport (η) and mobility (F s ) for self-cleansing design of sewers with deposited bed condition. The relationships between those two parameters were introduced in conditional form for specific ranges of F s , which makes it difficult to use as a practical tool for sewer design. In this study, using the same experimental data used by May and employing the particle swarm optimization algorithm, a unified equation is recommended based on η and F s . The developed model is compared with original May relationships as well as corresponding models available in the literature. A large amount of data taken from the literature is used for the models' evaluation. The results demonstrate that the developed model in this study is superior to May and other existing models in the literature. Due to the fact that in May's dimensionless parameters more effective variables in the sediment transport process in sewers with deposited bed condition are considered, it is concluded that the revised May equation proposed in this study is a reliable model for sewer design.

Optimization of the intravenous glucose tolerance test in T2DM patients using optimal experimental design.

PubMed

Silber, Hanna E; Nyberg, Joakim; Hooker, Andrew C; Karlsson, Mats O

2009-06-01

Intravenous glucose tolerance test (IVGTT) provocations are informative, but complex and laborious, for studying the glucose-insulin system. The objective of this study was to evaluate, through optimal design methodology, the possibilities of more informative and/or less laborious study design of the insulin modified IVGTT in type 2 diabetic patients. A previously developed model for glucose and insulin regulation was implemented in the optimal design software PopED 2.0. The following aspects of the study design of the insulin modified IVGTT were evaluated; (1) glucose dose, (2) insulin infusion, (3) combination of (1) and (2), (4) sampling times, (5) exclusion of labeled glucose. Constraints were incorporated to avoid prolonged hyper- and/or hypoglycemia and a reduced design was used to decrease run times. Design efficiency was calculated as a measure of the improvement with an optimal design compared to the basic design. The results showed that the design of the insulin modified IVGTT could be substantially improved by the use of an optimized design compared to the standard design and that it was possible to use a reduced number of samples. Optimization of sample times gave the largest improvement followed by insulin dose. The results further showed that it was possible to reduce the total sample time with only a minor loss in efficiency. Simulations confirmed the predictions from PopED. The predicted uncertainty of parameter estimates (CV) was low in all tested cases, despite the reduction in the number of samples/subject. The best design had a predicted average CV of parameter estimates of 19.5%. We conclude that improvement can be made to the design of the insulin modified IVGTT and that the most important design factor was the placement of sample times followed by the use of an optimal insulin dose. This paper illustrates how complex provocation experiments can be improved by sequential modeling and optimal design.

Computational Design of a Krueger Flap Targeting Conventional Slat Aerodynamics

NASA Technical Reports Server (NTRS)

Akaydin, H. Dogus; Housman, Jeffrey A.; Kiris, Cetin C.; Bahr, Christopher J.; Hutcheson, Florence V.

2016-01-01

In this study, we demonstrate the design of a Krueger flap as a substitute for a conventional slat in a high-lift system. This notional design, with the objective of matching equivalent-mission performance on aircraft approach, was required for a comparative aeroacoustic study with computational and experimental components. We generated a family of high-lift systems with Krueger flaps based on a set of design parameters. Then, we evaluated the high-lift systems using steady 2D RANS simulations to find a good match for the conventional slat, based on total lift coefficients in free-air. Finally, we evaluated the mean aerodynamics of the high-lift systems with Krueger flap and conventional slat as they were installed in an open-jet wind tunnel flow. The surface pressures predicted with the simulations agreed well with experimental results.

Development and testing of a high cycle life 30 A-h sealed AgO-Zn battery

NASA Technical Reports Server (NTRS)

Bogner, R. S.

1972-01-01

A two-phase program was initiated to investigate design parameters and technology to develop an improved AgO-Zn battery. The basic performance goal was 100 charge/discharge cycles (22 h/2 h) at 50 percent depth of discharge following a six-month period of charged stand at room temperature. Phase 1, cell evaluation, involved testing 70 cells in five-cell groups. The major design variables were active material ratios, electrolyte concentrations, separator systems, and negative plate shape. Phase 1 testing showed that cycle life could be improved 10 percent to 20 percent by using greater ratios of zinc to silver oxide and higher electrolyte concentrations. Wedge-shaped negatives increased cycle life by nearly 100 percent. Phase 2 battery evaluation, which was initiated before the Phase 1 results were known completely, involved evaluation of six designs as 19-cell batteries. Only one battery exceeded 100 cycles following nine months charged stand.

Evaluating 1-, 2- and 3- Parameter Logistic Models Using Model-Based and Empirically-Based Simulations under Homogeneous and Heterogeneous Set Conditions

ERIC Educational Resources Information Center

Rizavi, Saba; Way, Walter D.; Lu, Ying; Pitoniak, Mary; Steffen, Manfred

2004-01-01

The purpose of this study was to use realistically simulated data to evaluate various CAT designs for use with the verbal reasoning measure of the Medical College Admissions Test (MCAT). Factors such as item pool depth, content constraints, and item formats often cause repeated adaptive administrations of an item at ability levels that are not…

Evaluation of an Integrated Read-Out Layer Prototype

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

Abu-Ajamieh, Fayez

2011-07-01

This thesis presents evaluation results of an Integrated Read-out Layer (IRL), a proposed concept in scintillator-based calorimetry intended to meet the exceptional calorimetric requirements of the envisaged International Linear Collider (ILC). This study presents a full characterization of the prototype IRL, including exploration of relevant parameters, calibration performance, and the uniformity of response. The study represents proof of the IRL concept. Finally, proposed design enhancements are presented.

Evaluation of an Integrated Read-Out Layer Prototype

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

Abu-Ajamieh, Fayez; /NIU

2011-08-18

This thesis presents evaluation results of an Integrated Read-out Layer (IRL), a proposed concept in scintillator-based calorimetry intended to meet the exceptional calorimetric requirements of the envisaged International Linear Collider (ILC). This study presents a full characterization of the prototype IRL, including exploration of relevant parameters, calibration performance, and the uniformity of response. The study represents proof of the IRL concept. Finally, proposed design enhancements are presented.

Process and assembly plans for low cost commercial fuselage structure

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, Stephen; Starkey, Val

1991-01-01

Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization.

Developing the multiple stress-strain creep recovery (MS-SCR) test

NASA Astrophysics Data System (ADS)

Elnasri, Mahmoud; Airey, Gordon; Thom, Nick

2018-04-01

While most published work from Europe has been concerned with evaluating binders' resistance to rutting based on their stiffness (deformation resistance), work originating in the US has mainly been concerned with ranking binders based on their recoverability in a multiple stress form. This paper details the design of a new modified multiple stress-strain creep recovery (MS-SCR) test. The test is designed to evaluate binders' rutting resistance based on two rutting resistance mechanisms: stiffness and recoverability. A preliminary investigation is presented in this paper followed by details of the design of the new modified test. A 40/60 penetration grade bitumen and bitumen-filler mastics prepared with three filler concentrations (35%, 50%, and 65% filler content by mass of mastic) were tested. In addition, two polymer modified bitumens (PMBs) using the same base bitumen type were examined for validation. Two parameters are introduced to characterise the short and long recovery in the new test. In terms of stiffness, the test allows the behaviour of binders at different stress levels and loading cycles to be studied and produces a new parameter that can quantify the degree of modification. Finally, a relationship between nonlinearity and normal force in the test was investigated.

Analytical Modelling of the Effects of Different Gas Turbine Cooling Techniques on Engine Performance =

NASA Astrophysics Data System (ADS)

Uysal, Selcuk Can

In this research, MATLAB SimulinkRTM was used to develop a cooled engine model for industrial gas turbines and aero-engines. The model consists of uncooled on-design, mean-line turbomachinery design and a cooled off-design analysis in order to evaluate the engine performance parameters by using operating conditions, polytropic efficiencies, material information and cooling system details. The cooling analysis algorithm involves a 2nd law analysis to calculate losses from the cooling technique applied. The model is used in a sensitivity analysis that evaluates the impacts of variations in metal Biot number, thermal barrier coating Biot number, film cooling effectiveness, internal cooling effectiveness and maximum allowable blade temperature on main engine performance parameters of aero and industrial gas turbine engines. The model is subsequently used to analyze the relative performance impact of employing Anti-Vortex Film Cooling holes (AVH) by means of data obtained for these holes by Detached Eddy Simulation-CFD Techniques that are valid for engine-like turbulence intensity conditions. Cooled blade configurations with AVH and other different external cooling techniques were used in a performance comparison study. (Abstract shortened by ProQuest.).

Rapid Airplane Parametric Input Design (RAPID)

NASA Technical Reports Server (NTRS)

Smith, Robert E.

1995-01-01

RAPID is a methodology and software system to define a class of airplane configurations and directly evaluate surface grids, volume grids, and grid sensitivity on and about the configurations. A distinguishing characteristic which separates RAPID from other airplane surface modellers is that the output grids and grid sensitivity are directly applicable in CFD analysis. A small set of design parameters and grid control parameters govern the process which is incorporated into interactive software for 'real time' visual analysis and into batch software for the application of optimization technology. The computed surface grids and volume grids are suitable for a wide range of Computational Fluid Dynamics (CFD) simulation. The general airplane configuration has wing, fuselage, horizontal tail, and vertical tail components. The double-delta wing and tail components are manifested by solving a fourth order partial differential equation (PDE) subject to Dirichlet and Neumann boundary conditions. The design parameters are incorporated into the boundary conditions and therefore govern the shapes of the surfaces. The PDE solution yields a smooth transition between boundaries. Surface grids suitable for CFD calculation are created by establishing an H-type topology about the configuration and incorporating grid spacing functions in the PDE equation for the lifting components and the fuselage definition equations. User specified grid parameters govern the location and degree of grid concentration. A two-block volume grid about a configuration is calculated using the Control Point Form (CPF) technique. The interactive software, which runs on Silicon Graphics IRIS workstations, allows design parameters to be continuously varied and the resulting surface grid to be observed in real time. The batch software computes both the surface and volume grids and also computes the sensitivity of the output grid with respect to the input design parameters by applying the precompiler tool ADIFOR to the grid generation program. The output of ADIFOR is a new source code containing the old code plus expressions for derivatives of specified dependent variables (grid coordinates) with respect to specified independent variables (design parameters). The RAPID methodology and software provide a means of rapidly defining numerical prototypes, grids, and grid sensitivity of a class of airplane configurations. This technology and software is highly useful for CFD research for preliminary design and optimization processes.

Evaluating Management Information Systems, A Protocol for Automated Peer Review Systems

PubMed Central

Black, Gordon C.

1980-01-01

This paper discusses key issues in evaluating an automated Peer Review System. Included are the conceptual base, design, steps in planning structural components, operation parameters, criteria, costs and a detailed outline or protocol for use in the evaluation. At the heart of the Peer Review System is the criteria utilized for measuring quality. Criteria evaluation should embrace, as a minimum, appropriateness, validity and reliability, and completemess or comprehensiveness of content. Such an evaluation is not complete without determining the impact (clinical outcome) of the service system or the patient and the population served.

Effect of environmental parameters on habitat structural weight and cost

NASA Technical Reports Server (NTRS)

Bock, E.; Lambrou, F., Jr.; Simon, M.

1979-01-01

Space-settlement conceptual designs were previously accomplished using earth-normal physiological conditions. The habitat weight and cost penalties associated with this conservative design approach are quantified. These penalties are identified by comparison of conservative earth-normal designs with habitats designed to less than earth-normal conditions. Physiological research areas are also recommended as a necessary prerequisite to realizing these potential weight and cost savings. Major habitat structural elements, that is, pressure shell and radiation shielding, for populations of 100, 10,000, and 1,000,000, are evaluated for effects of atmospheric pressure, pseudogravity level, radiation shielding thickness, and habitat configuration.

Evaluation of Signal Regeneration Impact on the Power Efficiency of Long-Haul DWDM Systems

NASA Astrophysics Data System (ADS)

Pavlovs, D.; Bobrovs, V.; Parfjonovs, M.; Alsevska, A.; Ivanovs, G.

2017-10-01

Due to potential economic benefits and expected environmental impact, the power consumption issue in wired networks has become a major challenge. Furthermore, continuously increasing global Internet traffic demands high spectral efficiency values. As a result, the relationship between spectral efficiency and energy consumption of telecommunication networks has become a popular topic of academic research over the past years, where a critical parameter is power efficiency. The present research contains calculation results that can be used by optical network designers and operators as guidance for developing more power efficient communication networks if the planned system falls within the scope of this paper. The research results are presented as average aggregated traffic curves that provide more flexible data for the systems with different spectrum availability. Further investigations could be needed in order to evaluate the parameters under consideration taking into account particular spectral parameters, e.g., the entire C-band.

AST Combustion Workshop: Diagnostics Working Group Report

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Hicks, Yolanda R.; Hanson, Ronald K.

1996-01-01

A workshop was convened under NASA's Advanced Subsonics Technologies (AST) Program. Many of the principal combustion diagnosticians from industry, academia, and government laboratories were assembled in the Diagnostics/Testing Subsection of this workshop to discuss the requirements and obstacles to the successful implementation of advanced diagnostic techniques to the test environment of the proposed AST combustor. The participants, who represented the major relevant areas of advanced diagnostic methods currently applied to combustion and related fields, first established the anticipated AST combustor flowfield conditions. Critical flow parameters were then examined and prioritized as to their importance to combustor/fuel injector design and manufacture, environmental concerns, and computational interests. Diagnostic techniques were then evaluated in terms of current status, merits and obstacles for each flow parameter. All evaluations are presented in tabular form and recommendations are made on the best-suited diagnostic method to implement for each flow parameter in order of applicability and intrinsic value.

Optimization of a sensor cluster for determination of trajectories and velocities of supersonic objects

NASA Astrophysics Data System (ADS)

Cannella, Marco; Sciuto, Salvatore Andrea

2001-04-01

An evaluation of errors for a method for determination of trajectories and velocities of supersonic objects is conducted. The analytical study of a cluster, composed of three pressure transducers and generally used as an apparatus for cinematic determination of parameters of supersonic objects, is developed. Furthermore, detailed investigation into the accuracy of this cluster on determination of the slope of an incoming shock wave is carried out for optimization of the device. In particular, a specific non-dimensional parameter is proposed in order to evaluate accuracies for various values of parameters and reference graphs are provided in order to properly design the sensor cluster. Finally, on the basis of the error analysis conducted, a discussion on the best estimation of the relative distance for the sensor as a function of temporal resolution of the measuring system is presented.

Consumer perception of dry-cured sheep meat products: Influence of process parameters under different evoked contexts.

PubMed

de Andrade, Juliana Cunha; Nalério, Elen Silveira; Giongo, Citieli; de Barcellos, Marcia Dutra; Ares, Gastón; Deliza, Rosires

2017-08-01

The development of high-quality air-dried cured sheep meat products adapted to meet consumer demands represent an interesting option to add value to the meat of adult animals. The present study aimed to evaluate the influence of process parameters on consumer choice of two products from sheep meat under different evoked contexts, considering product concepts. A total of 375 Brazilian participants completed a choice-based conjoint task with three 2-level variables for each product: maturation time, smoking, and sodium reduction for dry-cured sheep ham, and natural antioxidant, smoking, and sodium reduction for sheep meat coppa. A between-subjects experimental design was used to evaluate the influence of consumption context on consumer choices. All the process parameters significantly influenced consumer choice. However, their relative importance was affected by evoked context. Copyright © 2017. Published by Elsevier Ltd.

Deformable Surface Accommodating Intraocular Lens: Second Generation Prototype Design Methodology and Testing.

PubMed

McCafferty, Sean J; Schwiegerling, Jim T

2015-04-01

Present an analysis methodology for developing and evaluating accommodating intraocular lenses incorporating a deformable interface. The next generation design of extruded gel interface intraocular lens is presented. A prototype based upon similar previously in vivo proven design was tested with measurements of actuation force, lens power, interface contour, optical transfer function, and visual Strehl ratio. Prototype verified mathematical models were used to optimize optical and mechanical design parameters to maximize the image quality and minimize the required force to accommodate. The prototype lens produced adequate image quality with the available physiologic accommodating force. The iterative mathematical modeling based upon the prototype yielded maximized optical and mechanical performance through maximum allowable gel thickness to extrusion diameter ratio, maximum feasible refractive index change at the interface, and minimum gel material properties in Poisson's ratio and Young's modulus. The design prototype performed well. It operated within the physiologic constraints of the human eye including the force available for full accommodative amplitude using the eye's natural focusing feedback, while maintaining image quality in the space available. The parameters that optimized optical and mechanical performance were delineated as those, which minimize both asphericity and actuation pressure. The design parameters outlined herein can be used as a template to maximize the performance of a deformable interface intraocular lens. The article combines a multidisciplinary basic science approach from biomechanics, optical science, and ophthalmology to optimize an intraocular lens design suitable for preliminary animal trials.

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

PubMed

Zhang, Xia; Hu, Changqin

2017-09-08

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

Application of the quality by design approach to the drug substance manufacturing process of an Fc fusion protein: towards a global multi-step design space.

PubMed

Eon-duval, Alex; Valax, Pascal; Solacroup, Thomas; Broly, Hervé; Gleixner, Ralf; Strat, Claire L E; Sutter, James

2012-10-01

The article describes how Quality by Design principles can be applied to the drug substance manufacturing process of an Fc fusion protein. First, the quality attributes of the product were evaluated for their potential impact on safety and efficacy using risk management tools. Similarly, process parameters that have a potential impact on critical quality attributes (CQAs) were also identified through a risk assessment. Critical process parameters were then evaluated for their impact on CQAs, individually and in interaction with each other, using multivariate design of experiment techniques during the process characterisation phase. The global multi-step Design Space, defining operational limits for the entire drug substance manufacturing process so as to ensure that the drug substance quality targets are met, was devised using predictive statistical models developed during the characterisation study. The validity of the global multi-step Design Space was then confirmed by performing the entire process, from cell bank thawing to final drug substance, at its limits during the robustness study: the quality of the final drug substance produced under different conditions was verified against predefined targets. An adaptive strategy was devised whereby the Design Space can be adjusted to the quality of the input material to ensure reliable drug substance quality. Finally, all the data obtained during the process described above, together with data generated during additional validation studies as well as manufacturing data, were used to define the control strategy for the drug substance manufacturing process using a risk assessment methodology. Copyright © 2012 Wiley-Liss, Inc.

High-volume image quality assessment systems: tuning performance with an interactive data visualization tool

NASA Astrophysics Data System (ADS)

Bresnahan, Patricia A.; Pukinskis, Madeleine; Wiggins, Michael

1999-03-01

Image quality assessment systems differ greatly with respect to the number and types of mags they need to evaluate, and their overall architectures. Managers of these systems, however, all need to be able to tune and evaluate system performance, requirements often overlooked or under-designed during project planning. Performance tuning tools allow users to define acceptable quality standards for image features and attributes by adjusting parameter settings. Performance analysis tools allow users to evaluate and/or predict how well a system performs in a given parameter state. While image assessment algorithms are becoming quite sophisticated, duplicating or surpassing the human decision making process in their speed and reliability, they often require a greater investment in 'training' or fine tuning of parameters in order to achieve optimum performance. This process may involve the analysis of hundreds or thousands of images, generating a large database of files and statistics that can be difficult to sort through and interpret. Compounding the difficulty is the fact that personnel charged with tuning and maintaining the production system may not have the statistical or analytical background required for the task. Meanwhile, hardware innovations have greatly increased the volume of images that can be handled in a given time frame, magnifying the consequences of running a production site with an inadequately tuned system. In this paper, some general requirements for a performance evaluation and tuning data visualization system are discussed. A custom engineered solution to the tuning and evaluation problem is then presented, developed within the context of a high volume image quality assessment, data entry, OCR, and image archival system. A key factor influencing the design of the system was the context-dependent definition of image quality, as perceived by a human interpreter. This led to the development of a five-level, hierarchical approach to image quality evaluation. Lower-level pass-fail conditions and decision rules were coded into the system. Higher-level image quality states were defined by allowing the users to interactively adjust the system's sensitivity to various image attributes by manipulating graphical controls. Results were presented in easily interpreted bar graphs. These graphs were mouse- sensitive, allowing the user to more fully explore the subsets of data indicated by various color blocks. In order to simplify the performance evaluation and tuning process, users could choose to view the results of (1) the existing system parameter state, (2) the results of any arbitrary parameter values they chose, or (3) the results of a quasi-optimum parameter state, derived by applying a decision rule to a large set of possible parameter states. Giving managers easy- to-use tools for defining the more subjective aspects of quality resulted in a system that responded to contextual cues that are difficult to hard-code. It had the additional advantage of allowing the definition of quality to evolve over time, as users became more knowledgeable as to the strengths and limitations of an automated quality inspection system.

Evaluation of Cooling Conditions for a High Heat Flux Testing Facility Based on Plasma-Arc Lamps

DOE PAGES

Charry, Carlos H.; Abdel-khalik, Said I.; Yoda, Minami; ...

2015-07-31

The new Irradiated Material Target Station (IMTS) facility for fusion materials at Oak Ridge National Laboratory (ORNL) uses an infrared plasma-arc lamp (PAL) to deliver incident heat fluxes as high as 27 MW/m 2. The facility is being used to test irradiated plasma-facing component materials as part of the joint US-Japan PHENIX program. The irradiated samples are to be mounted on molybdenum sample holders attached to a water-cooled copper rod. Depending on the size and geometry of samples, several sample holders and copper rod configurations have been fabricated and tested. As a part of the effort to design sample holdersmore » compatible with the high heat flux (HHF) testing to be conducted at the IMTS facility, numerical simulations have been performed for two different water-cooled sample holder designs using the ANSYS FLUENT 14.0 commercial computational fluid dynamics (CFD) software package. The primary objective of this work is to evaluate the cooling capability of different sample holder designs, i.e. to estimate their maximum allowable incident heat flux values. 2D axisymmetric numerical simulations are performed using the realizable k-ε turbulence model and the RPI nucleate boiling model within ANSYS FLUENT 14.0. The results of the numerical model were compared against the experimental data for two sample holder designs tested in the IMTS facility. The model has been used to parametrically evaluate the effect of various operational parameters on the predicted temperature distributions. The results were used to identify the limiting parameter for safe operation of the two sample holders and the associated peak heat flux limits. The results of this investigation will help guide the development of new sample holder designs.« less

Least-squares/parabolized Navier-Stokes procedure for optimizing hypersonic wind tunnel nozzles

NASA Technical Reports Server (NTRS)

Korte, John J.; Kumar, Ajay; Singh, D. J.; Grossman, B.

1991-01-01

A new procedure is demonstrated for optimizing hypersonic wind-tunnel-nozzle contours. The procedure couples a CFD computer code to an optimization algorithm, and is applied to both conical and contoured hypersonic nozzles for the purpose of determining an optimal set of parameters to describe the surface geometry. A design-objective function is specified based on the deviation from the desired test-section flow-field conditions. The objective function is minimized by optimizing the parameters used to describe the nozzle contour based on the solution to a nonlinear least-squares problem. The effect of the changes in the nozzle wall parameters are evaluated by computing the nozzle flow using the parabolized Navier-Stokes equations. The advantage of the new procedure is that it directly takes into account the displacement effect of the boundary layer on the wall contour. The new procedure provides a method for optimizing hypersonic nozzles of high Mach numbers which have been designed by classical procedures, but are shown to produce poor flow quality due to the large boundary layers present in the test section. The procedure is demonstrated by finding the optimum design parameters for a Mach 10 conical nozzle and a Mach 6 and a Mach 15 contoured nozzle.

Comparative evaluation of subgrade resilient modulus from non-destructive, in-situ, and laboratory methods : technical summary report.

DOT National Transportation Integrated Search

2008-09-01

The Resilient Modulus (Mr) of pavement materials and subgrades is an important input : parameter for the design of pavement structures. The Repeated Loading Triaxial (RLT) test : typically determines Mr. However, the RLT test requires well trained pe...

Classification of hydrological parameter sensitivity and evaluation of parameter transferability across 431 US MOPEX basins

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

Ren, Huiying; Hou, Zhangshuan; Huang, Maoyi

The Community Land Model (CLM) represents physical, chemical, and biological processes of the terrestrial ecosystems that interact with climate across a range of spatial and temporal scales. As CLM includes numerous sub-models and associated parameters, the high-dimensional parameter space presents a formidable challenge for quantifying uncertainty and improving Earth system predictions needed to assess environmental changes and risks. This study aims to evaluate the potential of transferring hydrologic model parameters in CLM through sensitivity analyses and classification across watersheds from the Model Parameter Estimation Experiment (MOPEX) in the United States. The sensitivity of CLM-simulated water and energy fluxes to hydrologicalmore » parameters across 431 MOPEX basins are first examined using an efficient stochastic sampling-based sensitivity analysis approach. Linear, interaction, and high-order nonlinear impacts are all identified via statistical tests and stepwise backward removal parameter screening. The basins are then classified accordingly to their parameter sensitivity patterns (internal attributes), as well as their hydrologic indices/attributes (external hydrologic factors) separately, using a Principal component analyses (PCA) and expectation-maximization (EM) –based clustering approach. Similarities and differences among the parameter sensitivity-based classification system (S-Class), the hydrologic indices-based classification (H-Class), and the Koppen climate classification systems (K-Class) are discussed. Within each S-class with similar parameter sensitivity characteristics, similar inversion modeling setups can be used for parameter calibration, and the parameters and their contribution or significance to water and energy cycling may also be more transferrable. This classification study provides guidance on identifiable parameters, and on parameterization and inverse model design for CLM but the methodology is applicable to other models. Inverting parameters at representative sites belonging to the same class can significantly reduce parameter calibration efforts.« less

Design of compact long-period gratings imprinted in optimized photonic crystal fibers

NASA Astrophysics Data System (ADS)

Seraji, F. E.; Chehreghani Anzabi, L.; Farsinezhad, S.

2009-10-01

To imprint a long-period grating (LPG) in a photonic crystal fiber (PCF) with an optimum response, first the parameters of the PCF should be optimized. In this paper, by using a semi-analytical enhanced improved vectorial effective index method, the optimized PCF parameters are determined by dividing the single-mode operation of the PCF into two regions in terms of air-hole spacing Λ ( Λ>3 μm and Λ≤3 μm). For each region appropriate expressions are suggested to evaluate the PCF parameters. By calculating the effective refractive index difference between the optimized core and cladding of the PCF under a phase-matching condition, the optimum grating period in terms of the PCF parameters is obtained.

Modeling polyvinyl chloride Plasma Modification by Neural Networks

NASA Astrophysics Data System (ADS)

Wang, Changquan

2018-03-01

Neural networks model were constructed to analyze the connection between dielectric barrier discharge parameters and surface properties of material. The experiment data were generated from polyvinyl chloride plasma modification by using uniform design. Discharge voltage, discharge gas gap and treatment time were as neural network input layer parameters. The measured values of contact angle were as the output layer parameters. A nonlinear mathematical model of the surface modification for polyvinyl chloride was developed based upon the neural networks. The optimum model parameters were obtained by the simulation evaluation and error analysis. The results of the optimal model show that the predicted value is very close to the actual test value. The prediction model obtained here are useful for discharge plasma surface modification analysis.

Study of the zinc-silver oxide battery system

NASA Technical Reports Server (NTRS)

Nanis, L.

1973-01-01

Theoretical and experimental models for the evaluation of current distribution in flooded, porous electrodes are discussed. An approximation for the local current distribution function was derived for conditions of a linear overpotential, a uniform concentration, and a very conductive matrix. By considering the porous electrode to be an analog of chemical catalyst structures, a dimensionless performance parameter was derived from the approximated current distribution function. In this manner the electrode behavior was characterized in terms of an electrochemical Thiele parameter and an effectiveness factor. It was shown that the electrochemical engineering approach makes possible the organizations of theoretical descriptions and of practical experience in the form of dimensionless parameters, such as the electrochemical Thiele parameters, and hence provides useful information for the design of new electrochemical systems.

AEROSOL PARTICLE COLLECTOR DESIGN STUDY

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

Lee, S; Richard Dimenna, R

2007-09-27

A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitfulmore » areas for further study are proposed.« less

Stress Regression Analysis of Asphalt Concrete Deck Pavement Based on Orthogonal Experimental Design and Interlayer Contact

NASA Astrophysics Data System (ADS)

Wang, Xuntao; Feng, Jianhu; Wang, Hu; Hong, Shidi; Zheng, Supei

2018-03-01

A three-dimensional finite element box girder bridge and its asphalt concrete deck pavement were established by ANSYS software, and the interlayer bonding condition of asphalt concrete deck pavement was assumed to be contact bonding condition. Orthogonal experimental design is used to arrange the testing plans of material parameters, and an evaluation of the effect of different material parameters in the mechanical response of asphalt concrete surface layer was conducted by multiple linear regression model and using the results from the finite element analysis. Results indicated that stress regression equations can well predict the stress of the asphalt concrete surface layer, and elastic modulus of waterproof layer has a significant influence on stress values of asphalt concrete surface layer.

Nondimensional Representations for Occulter Design and Performance Evaluation

NASA Technical Reports Server (NTRS)

Cady, Eric

2011-01-01

An occulter is a spacecraft with a precisely-shaped optical edges which ies in formation with a telescope, blocking light from a star while leaving light from nearby planets una ected. Using linear optimization, occulters can be designed for use with telescopes over a wide range of telescope aperture sizes, science bands, and starlight suppression levels. It can be shown that this optimization depends primarily on a small number of independent nondimensional parameters, which correspond to Fresnel numbers and physical scales and enter the optimization only as constraints. We show how these can be used to span the parameter space of possible optimized occulters; this data set can then be mined to determine occulter sizes for various mission scenarios and sets of engineering constraints.

Comparative evaluation of the powder and compression properties of various grades and brands of microcrystalline cellulose by multivariate methods.

PubMed

Haware, Rahul V; Bauer-Brandl, Annette; Tho, Ingunn

2010-01-01

The present work challenges a newly developed approach to tablet formulation development by using chemically identical materials (grades and brands of microcrystalline cellulose). Tablet properties with respect to process and formulation parameters (e.g. compression speed, added lubricant and Emcompress fractions) were evaluated by 2(3)-factorial designs. Tablets of constant true volume were prepared on a compaction simulator at constant pressure (approx. 100 MPa). The highly repeatable and accurate force-displacement data obtained was evaluated by simple 'in-die' Heckel method and work descriptors. Relationships and interactions between formulation, process and tablet parameters were identified and quantified by multivariate analysis techniques; principal component analysis (PCA) and partial least square regressions (PLS). The method proved to be able to distinguish between different grades of MCC and even between two different brands of the same grade (Avicel PH 101 and Vivapur 101). One example of interaction was studied in more detail by mixed level design: The interaction effect of lubricant and Emcompress on elastic recovery of Avicel PH 102 was demonstrated to be complex and non-linear using the development tool under investigation.

Cubesat in-situ degradation detector (CIDD)

NASA Astrophysics Data System (ADS)

Rievers, Benny; Milke, Alexander; Salden, Daniel

2015-07-01

The design of the thermal control and management system (TCS) is a central task in satellite design. In order to evaluate and dimensionize the properties of the TCS, material parameters specifying the conductive and radiative properties of the different TCS components have to be known including their respective variations within the mission lifetime. In particular the thermo-optical properties of the outer surfaces including critical TCS components such as radiators and thermal insulation are subject to degradation caused by interaction with the space environment. The evaluation of these material parameters by means of ground testing is a time-consuming and expensive endeavor. Long-term in-situ measurements on board the ISS or large satellites not only realize a better implementation of the influence of the space environment but also imply high costs. Motivated by this we propose the utilization of low-cost nano-satellite systems to realize material tests within space at a considerably reduced cost. We present a nanosat-scale degradation sensor concept which realizes low power consumption and data rates compatible with nanosat boundaries at UHF radio. By means of a predefined measurement and messaging cycle temperature curves are measured and evaluated on ground to extract the change of absorptivity and emissivity over mission lifetime.

Design of experiment (DOE) study of biodegradable magnesium alloy synthesized by mechanical alloying using fractional factorial design

NASA Astrophysics Data System (ADS)

Salleh, Emee Marina; Ramakrishnan, Sivakumar; Hussain, Zuhailawati

2014-06-01

The biodegradable nature of magnesium (Mg) makes it a most highlighted and attractive to be used as implant materials. However, rapid corrosion rate of Mg alloys especially in electrolytic aqueous environment limits its performance. In this study, Mg alloy was mechanically milled by incorporating manganese (Mn) as alloying element. An attempt was made to study both effect of mechanical alloying and subsequent consolidation processes on the bulk properties of Mg-Mn alloys. 2k-2 factorial design was employed to determine the significant factors in producing Mg alloy which has properties closes to that of human bones. The design considered six factors (i.e. milling time, milling speed, weight percentage of Mn, compaction pressure, sintering temperature and sintering time). Density and hardness were chosen as the responses for assessing the most significant parameters that affected the bulk properties of Mg-Mn alloys. The experimental variables were evaluated using ANOVA and regression model. The main parameter investigated was compaction pressure.

Design of Backpack to Aid Elderly for the Mazu Touring Procession in Taiwan

NASA Astrophysics Data System (ADS)

Chao, F. L.; Huang, Y. C.; Su, J. Y.; Sun, C. L.; Chen, C. C.

2017-09-01

The Dajia Mazu Touring Procession is a 9-day long religious event held annually. However, for the elderly participants, it is a big burden especially in regards to physical strength. The goal of designing backpack is to reduce the physiological stress of elderly during the procession. Firstly, physical parameters were measured to explore the dimension parameters by testing. The height of the chair is different from that of the kneeling pad; a smooth curve was chosen to coordinate the two as the main outline of the backpack. Secondly, material selections based on following limits were considered: (1) acceptable weight and size, (2) intermediate price and (3) a design that is fitting to the Dajia event. The material and structural strength were evaluated for wood, bamboo, stainless steel. Two design concept were proposed, wood is selected for construction and testing by users. The texture of the backpack is Rush grass, it was built successfully to cover the backpack’s external surface to meet local culture features.

Effect of flame stabilizer design on performance and exhaust pollutants of a two-row 72-module swirl-can combustor

NASA Technical Reports Server (NTRS)

Biaglow, J. A.; Trout, A. M.

1976-01-01

A test program was conducted to evaluate the effects of four flame stabilizer designs on the performance and gaseous pollutant levels of an experimental full-annular swirl-can combustor. Combustor operating parameters, including inlet-air temperature, reference velocity, and fuel-air ratio, were set to simulate conditions in a 30:1 pressure ratio engine. Combustor inlet total pressure was held constant at 6 atm due to the facility limit. Combustor performance and gaseous pollutant levels were strongly affected by the geometry and resulting total pressure loss of the four flame stabilizer designs investigated. The addition of shrouds to two designs produced an 18 to 22% decrease in the combustion chamber pressure loss and thus resulted in doubling the exit temperature pattern factor and up to 42% higher levels of oxides of nitrogen. A previously developed oxides of nitrogen correlating parameter agreed with each model within an emission index of plus or minus 1 but was not capable of correlating all models together.

Suggestion of Design Evaluation Plan based on Star Life Cycle to introduce the Information Minimalism Concept of KOREA Nuclear Plant

NASA Astrophysics Data System (ADS)

Jang, Gwi-sook; Lee, Seung-min; Park, Gee-yong

2018-01-01

The design of Korea Nuclear Power Plant (NPP) main control rooms (MCR) has been changed to be fully digitalized. Five or six display devices are assigned to each operator in NPP MCR to provide the information of safety parameter and plant status, and various control functions by connecting computerized control devices. Under this circumstance, the distributed displays can induce a dispersion of the operators' attention and increase the workload while conducting monitoring and control tasks efficiently. In addition, to support human operators to reduce their workload and increase the performance, the concepts of the ecological interface design (EID) and the operator-centered design were applied to the design HMI display. However these designs are applied to a limited set of screens and did not differ largely from the traditional HMI design in that the layout of the information is somewhere similar to P&IDs. In this paper, we propose a design evaluation plan based on star life cycle to introduce the information minimalism concept for designing an HMI display.

Design of a prototype flow microreactor for synthetic biology in vitro.

PubMed

Boehm, Christian R; Freemont, Paul S; Ces, Oscar

2013-09-07

As a reference platform for in vitro synthetic biology, we have developed a prototype flow microreactor for enzymatic biosynthesis. We report the design, implementation, and computer-aided optimisation of a three-step model pathway within a microfluidic reactor. A packed bed format was shown to be optimal for enzyme compartmentalisation after experimental evaluation of several approaches. The specific substrate conversion efficiency could significantly be improved by an optimised parameter set obtained by computational modelling. Our microreactor design provides a platform to explore new in vitro synthetic biology solutions for industrial biosynthesis.

An Interactive Program for the Calculation and Analysis of the Parameter Sensitivities in a Linear, Time-Invariant System.

DTIC Science & Technology

1981-03-01

tifiability is imposed; and the system designer now has a tool to evaluate how well the model describes the system . The algorithm is verified by checking its...xi I. Introduction In analyzing a system , the design engineer uses a mathematical model. The model, by its very definition, represents the system . It...number of G (See Eq (23).) can 18 give the designer a good indication of just how well the model defined by Eqs (1) through (3) describes the system

CO2 laser ranging systems study

NASA Technical Reports Server (NTRS)

Filippi, C. A.

1975-01-01

The conceptual design and error performance of a CO2 laser ranging system are analyzed. Ranging signal and subsystem processing alternatives are identified, and their comprehensive evaluation yields preferred candidate solutions which are analyzed to derive range and range rate error contributions. The performance results are presented in the form of extensive tables and figures which identify the ranging accuracy compromises as a function of the key system design parameters and subsystem performance indexes. The ranging errors obtained are noted to be within the high accuracy requirements of existing NASA/GSFC missions with a proper system design.

Development and Evaluation of a Sandia Cooler-based Refrigerator Condenser

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

Johnson, Terry A.; Kariya, Harumichi Arthur; Leick, Michael T.

This report describes the first design of a refrigerator condenser using the Sandia Cooler, i.e. air - bearing supported rotating heat - sink impeller. The project included ba seline performance testing of a residential refrigerator, analysis and design development of a Sandia Cooler condenser assembly including a spiral channel baseplate, and performance measurement and validation of this condenser system as incorporated into the residential refrigerator. Comparable performance was achieved in a 60% smaller volume package. The improved modeling parameters can now be used to guide more optimized designs and more accurately predict performance.

Application of Climate Impact Metrics to Rotorcraft Design

NASA Technical Reports Server (NTRS)

Russell, Carl; Johnson, Wayne

2013-01-01

Multiple metrics are applied to the design of large civil rotorcraft, integrating minimum cost and minimum environmental impact. The design mission is passenger transport with similar range and capacity to a regional jet. Separate aircraft designs are generated for minimum empty weight, fuel burn, and environmental impact. A metric specifically developed for the design of aircraft is employed to evaluate emissions. The designs are generated using the NDARC rotorcraft sizing code, and rotor analysis is performed with the CAMRAD II aeromechanics code. Design and mission parameters such as wing loading, disk loading, and cruise altitude are varied to minimize both cost and environmental impact metrics. This paper presents the results of these parametric sweeps as well as the final aircraft designs.

Application of Climate Impact Metrics to Civil Tiltrotor Design

NASA Technical Reports Server (NTRS)

Russell, Carl R.; Johnson, Wayne

2013-01-01

Multiple metrics are applied to the design of a large civil tiltrotor, integrating minimum cost and minimum environmental impact. The design mission is passenger transport with similar range and capacity to a regional jet. Separate aircraft designs are generated for minimum empty weight, fuel burn, and environmental impact. A metric specifically developed for the design of aircraft is employed to evaluate emissions. The designs are generated using the NDARC rotorcraft sizing code, and rotor analysis is performed with the CAMRAD II aeromechanics code. Design and mission parameters such as wing loading, disk loading, and cruise altitude are varied to minimize both cost and environmental impact metrics. This paper presents the results of these parametric sweeps as well as the final aircraft designs.

Particle Flow Calorimetry for the ILC

NASA Astrophysics Data System (ADS)

Magill, Stephen

2006-04-01

The Particle Flow approach to detector design is seen as the best way to achieve dijet mass resolutions suitable for the precision measurements anticipated at a future e^+e^- Linear Collider (LC). Particle Flow Algorithms (PFAs) affect not only the way data is analyzed, but are necessary and crucial elements used even in initial stages of detector design. In particular, the Calorimeter design parameters are almost entirely dependent on the optimized performance of the PFA. Use of PFAs imposes constraints on the granularity and segmentation of the readout cells, the choices of absorber and active media, and overall detector parameters such as the strength of the B-field, magnet bore, hermeticity, etc. PFAs must be flexible and modular in order to evaluate many detector models in simulation. The influence of PFA development on calorimetry is presented here with particular emphasis on results from the use of PFAs on several LC detector models.

The effect of structural design parameters on FPGA-based feed-forward space-time trellis coding-orthogonal frequency division multiplexing channel encoders

NASA Astrophysics Data System (ADS)

Passas, Georgios; Freear, Steven; Fawcett, Darren

2010-08-01

Orthogonal frequency division multiplexing (OFDM)-based feed-forward space-time trellis code (FFSTTC) encoders can be synthesised as very high speed integrated circuit hardware description language (VHDL) designs. Evaluation of their FPGA implementation can lead to conclusions that help a designer to decide the optimum implementation, given the encoder structural parameters. VLSI architectures based on 1-bit multipliers and look-up tables (LUTs) are compared in terms of FPGA slices and block RAMs (area), as well as in terms of minimum clock period (speed). Area and speed graphs versus encoder memory order are provided for quadrature phase shift keying (QPSK) and 8 phase shift keying (8-PSK) modulation and two transmit antennas, revealing best implementation under these conditions. The effect of number of modulation bits and transmit antennas on the encoder implementation complexity is also investigated.

The 3D Hough Transform for plane detection in point clouds: A review and a new accumulator design

NASA Astrophysics Data System (ADS)

Borrmann, Dorit; Elseberg, Jan; Lingemann, Kai; Nüchter, Andreas

2011-03-01

The Hough Transform is a well-known method for detecting parameterized objects. It is the de facto standard for detecting lines and circles in 2-dimensional data sets. For 3D it has attained little attention so far. Even for the 2D case high computational costs have lead to the development of numerous variations for the Hough Transform. In this article we evaluate different variants of the Hough Transform with respect to their applicability to detect planes in 3D point clouds reliably. Apart from computational costs, the main problem is the representation of the accumulator. Usual implementations favor geometrical objects with certain parameters due to uneven sampling of the parameter space. We present a novel approach to design the accumulator focusing on achieving the same size for each cell and compare it to existing designs. [Figure not available: see fulltext.

Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter

PubMed Central

Li, Huidong; Deng, Zhiqun Daniel; Yuan, Yong; Carlson, Thomas J.

2012-01-01

PZT ceramics have been widely used in underwater acoustic transducers. However, literature available discussing the design parameters of a miniaturized PZT-based low-duty-cycle transmitter is very limited. This paper discusses some of the design parameters—the backing material, driving voltage, PZT material type, power consumption and the transducer length of a miniaturized acoustic fish tag using a PZT tube. Four different types of PZT were evaluated with respect to the source level, energy consumption and bandwidth of the transducer. The effect of the tube length on the source level is discussed. The results demonstrate that ultralow-density closed-cell foam is the best backing material for the PZT tube. The Navy Type VI PZTs provide the best source level with relatively low energy consumption and that a low transducer capacitance is preferred for high efficiency. A 35% reduction in the transducer length results in 2 dB decrease in source level. PMID:23012534

Preliminary evaluation of turbofan cycle parameters and acoustical suppression on the noise and direct operating cost of a commercial Mach 0.85 transport

NASA Technical Reports Server (NTRS)

Eisenberg, J. D.

1975-01-01

A study was made of the effects of turbofan cycle parameters and the use of acoustic noise suppression material to quiet 200 passenger, Mach 0.85 trijets having design ranges of 2778, 4630, and 9260 kilometers (1500, 2500, and 5000 n. mi). Aircraft gross weight and direct operating cost, which varied with amount of suppression and cycle selection, are presented as functions of both EPNdB traded and 90 EPNdB contour footprint area. Noise levels 10.9 EPNdB below FAR 36 requirements result in a 5 percent increase in DOC for an aircraft designed for a range of 9260 kilometers (5000 n. mi.). An aircraft designed for a 2778 kilometer (1500 n. mi.) range would have an EPNdB level 14 below FAR 36 for this same economic penalty. In this range of noise level, fan-machinery noise is the principal source.

Remote sensing-aided systems for snow qualification, evapotranspiration estimation, and their application in hydrologic models

NASA Technical Reports Server (NTRS)

Korram, S.

1977-01-01

The design of general remote sensing-aided methodologies was studied to provide the estimates of several important inputs to water yield forecast models. These input parameters are snow area extent, snow water content, and evapotranspiration. The study area is Feather River Watershed (780,000 hectares), Northern California. The general approach involved a stepwise sequence of identification of the required information, sample design, measurement/estimation, and evaluation of results. All the relevent and available information types needed in the estimation process are being defined. These include Landsat, meteorological satellite, and aircraft imagery, topographic and geologic data, ground truth data, and climatic data from ground stations. A cost-effective multistage sampling approach was employed in quantification of all the required parameters. The physical and statistical models for both snow quantification and evapotranspiration estimation was developed. These models use the information obtained by aerial and ground data through appropriate statistical sampling design.

Optimum design of bridges with superelastic-friction base isolators against near-field earthquakes

NASA Astrophysics Data System (ADS)

Ozbulut, Osman E.; Hurlebaus, Stefan

2010-04-01

The seismic response of a multi-span continuous bridge isolated with novel superelastic-friction base isolator (S-FBI) is investigated under near-field earthquakes. The isolation system consists of a flat steel-Teflon sliding bearing and a superelastic NiTi shape memory alloy (SMA) device. Sliding bearings limit the maximum seismic forces transmitted to the superstructure to a certain value that is a function of friction coefficient of sliding interface. Superelastic SMA device provides restoring capability to the isolation system together with additional damping characteristics. The key design parameters of an S-FBI system are the natural period of the isolated, yielding displacement of SMA device, and the friction coefficient of the sliding bearings. The goal of this study is to obtain optimal values for each design parameter by performing sensitivity analyses of the isolated bridge. First, a three-span continuous bridge is modeled as a two-degrees-of-freedom with S-FBI system. A neuro-fuzzy model is used to capture rate-dependent nonlinear behavior of SMA device. A time-dependent method which employs wavelets to adjust accelerograms to match a target response spectrum with minimum changes on the other characteristics of ground motions is used to generate ground motions used in the simulations. Then, a set of nonlinear time history analyses of the isolated bridge is performed. The variation of the peak response quantities of the isolated bridge is shown as a function of design parameters. Also, the influence of temperature variations on the effectiveness of S-FBI system is evaluated. The results show that the optimum design of the isolated bridge with S-FBI system can be achieved by a judicious specification of design parameters.

Inverse modeling approach for evaluation of kinetic parameters of a biofilm reactor using tabu search.

PubMed

Kumar, B Shiva; Venkateswarlu, Ch

2014-08-01

The complex nature of biological reactions in biofilm reactors often poses difficulties in analyzing such reactors experimentally. Mathematical models could be very useful for their design and analysis. However, application of biofilm reactor models to practical problems proves somewhat ineffective due to the lack of knowledge of accurate kinetic models and uncertainty in model parameters. In this work, we propose an inverse modeling approach based on tabu search (TS) to estimate the parameters of kinetic and film thickness models. TS is used to estimate these parameters as a consequence of the validation of the mathematical models of the process with the aid of measured data obtained from an experimental fixed-bed anaerobic biofilm reactor involving the treatment of pharmaceutical industry wastewater. The results evaluated for different modeling configurations of varying degrees of complexity illustrate the effectiveness of TS for accurate estimation of kinetic and film thickness model parameters of the biofilm process. The results show that the two-dimensional mathematical model with Edward kinetics (with its optimum parameters as mu(max)rho(s)/Y = 24.57, Ks = 1.352 and Ki = 102.36) and three-parameter film thickness expression (with its estimated parameters as a = 0.289 x 10(-5), b = 1.55 x 10(-4) and c = 15.2 x 10(-6)) better describes the biofilm reactor treating the industry wastewater.

Process to evaluate hematological parameters that reflex to manual differential cell counts in a pediatric institution.

PubMed

Guarner, Jeannette; Atuan, Maria Ana; Nix, Barbara; Mishak, Christopher; Vejjajiva, Connie; Curtis, Cheri; Park, Sunita; Mullins, Richard

2010-01-01

Each institution sets specific parameters obtained by automated hematology analyzers to trigger manual counts. We designed a process to decrease the number of manual differential cell counts without impacting patient care. We selected new criteria that prompt manual counts and studied the impact these changes had in 2 days of work and in samples of patients with newly diagnosed leukemia, sickle cell disease, and presence of left shift. By using fewer parameters and expanding our ranges we decreased the number of manual counts by 20%. The parameters that prompted manual counts most frequently were the presence of blast flags and nucleated red blood cells, 2 parameters that were not changed. The parameters that accounted for a decrease in the number of manual counts were the white blood cell count and large unstained cells. Eight of 32 patients with newly diagnosed leukemia did not show blast flags; however, other parameters triggered manual counts. In 47 patients with sickle cell disease, nucleated red cells and red cell variability prompted manual review. Bands were observed in 18% of the specimens and 4% would not have been counted manually with the new criteria, for the latter the mean band count was 2.6%. The process we followed to evaluate hematological parameters that reflex to manual differential cell counts increased efficiency without compromising patient care in our hospital system.

Challenges of Developing Design Discharge Estimates with Uncertain Data and Information

NASA Astrophysics Data System (ADS)

Senarath, S. U. S.

2016-12-01

This study focuses on design discharge estimates obtained for gauged basins through flood flow frequency analysis. Bulletin 17B (B17B) guidelines are widely used in the USA for developing these design estimates, which are required for many water resources engineering design applications. A set of outlier and historical data, and distribution parameter selection options is included in these guidelines. These options are provided in the guidelines as a means of accounting for uncertain data and information, primarily in the flow record. The individual as well as the cumulative effects of each of these preferences on design discharge estimates are evaluated in this study by using data from several gauges that are part of the United States Geological Survey's Hydro-Climatic Data Network. The results of this study show that despite the availability of rigorous and detailed guidelines for flood frequency analysis, the design discharge estimates can still vary substantially, from user to user, based on data and model parameter selection options chosen by each user. Thus, the findings of this study have strong implications for water resources engineers and other professionals who use B17B-based design discharge estimates in their work.

Robust optimal design of diffusion-weighted magnetic resonance experiments for skin microcirculation

NASA Astrophysics Data System (ADS)

Choi, J.; Raguin, L. G.

2010-10-01

Skin microcirculation plays an important role in several diseases including chronic venous insufficiency and diabetes. Magnetic resonance (MR) has the potential to provide quantitative information and a better penetration depth compared with other non-invasive methods such as laser Doppler flowmetry or optical coherence tomography. The continuous progress in hardware resulting in higher sensitivity must be coupled with advances in data acquisition schemes. In this article, we first introduce a physical model for quantifying skin microcirculation using diffusion-weighted MR (DWMR) based on an effective dispersion model for skin leading to a q-space model of the DWMR complex signal, and then design the corresponding robust optimal experiments. The resulting robust optimal DWMR protocols improve the worst-case quality of parameter estimates using nonlinear least squares optimization by exploiting available a priori knowledge of model parameters. Hence, our approach optimizes the gradient strengths and directions used in DWMR experiments to robustly minimize the size of the parameter estimation error with respect to model parameter uncertainty. Numerical evaluations are presented to demonstrate the effectiveness of our approach as compared to conventional DWMR protocols.

Experimental analysis of pressure controlled atomization process (PCAP) coatings for replacement of hard chromium plating

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

Tierney, J.C.; Glovan, R.J.; Witt, S.J.

1995-12-31

A four-phase experimental design was utilized to evaluate the abrasive wear and corrosion protection characteristics of VERSAlloy 50 coatings applied to AISI 4130 steel sheet. The coatings were applied with the Pressure Controlled Atomization Process (PCAP), a new thermal spray process being developed for the United States Air Force to replace hard chromium plating. Phase 1 of the design consisted of an evaluation of deposit profiles that were sprayed at five different standoff distances. Profile measurements yielded standard deviations ({sigma}) of the plume at each of the spray distances. Phase 2 consisted of a completely randomized series of eight spraymore » tests in which the track gap or distance between consecutive spray passes was varied by amounts of 0.5{sigma}, 1{sigma}, 2{sigma}, and 3{sigma}. The sprayed test coupons were then evaluated for corrosion protection, abrasive wear resistance, microhardness, and porosity. Results from Phase 2 were used to determine the best track gap or overlap for Phase 3 and Phase 4 testing. Phase 3 consisted of 22-run central composite design. The test coupons were evaluated the same as in Phase 2. Statistical analysis of Phase 3 data revealed that the optimal system operating parameters produced coatings that would either provide superior corrosion protection or resistance to abrasive wear. Phase 4 consisted of four spray tests to validate the results obtained in Phase 3. Phase 4 test coupons were again evaluated with the same analysis as in Phases 2 and 3. The validation tests indicated that PCAP system operating parameters could be controlled to produce VERSAlloy 50 coatings with superior corrosion protection or resistance to abrasive wear.« less

Bayesian uncertainty analysis for complex systems biology models: emulation, global parameter searches and evaluation of gene functions.

PubMed

Vernon, Ian; Liu, Junli; Goldstein, Michael; Rowe, James; Topping, Jen; Lindsey, Keith

2018-01-02

Many mathematical models have now been employed across every area of systems biology. These models increasingly involve large numbers of unknown parameters, have complex structure which can result in substantial evaluation time relative to the needs of the analysis, and need to be compared to observed data of various forms. The correct analysis of such models usually requires a global parameter search, over a high dimensional parameter space, that incorporates and respects the most important sources of uncertainty. This can be an extremely difficult task, but it is essential for any meaningful inference or prediction to be made about any biological system. It hence represents a fundamental challenge for the whole of systems biology. Bayesian statistical methodology for the uncertainty analysis of complex models is introduced, which is designed to address the high dimensional global parameter search problem. Bayesian emulators that mimic the systems biology model but which are extremely fast to evaluate are embeded within an iterative history match: an efficient method to search high dimensional spaces within a more formal statistical setting, while incorporating major sources of uncertainty. The approach is demonstrated via application to a model of hormonal crosstalk in Arabidopsis root development, which has 32 rate parameters, for which we identify the sets of rate parameter values that lead to acceptable matches between model output and observed trend data. The multiple insights into the model's structure that this analysis provides are discussed. The methodology is applied to a second related model, and the biological consequences of the resulting comparison, including the evaluation of gene functions, are described. Bayesian uncertainty analysis for complex models using both emulators and history matching is shown to be a powerful technique that can greatly aid the study of a large class of systems biology models. It both provides insight into model behaviour and identifies the sets of rate parameters of interest.

Bayesian Parameter Estimation for Heavy-Duty Vehicles

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

Miller, Eric; Konan, Arnaud; Duran, Adam

2017-03-28

Accurate vehicle parameters are valuable for design, modeling, and reporting. Estimating vehicle parameters can be a very time-consuming process requiring tightly-controlled experimentation. This work describes a method to estimate vehicle parameters such as mass, coefficient of drag/frontal area, and rolling resistance using data logged during standard vehicle operation. The method uses Monte Carlo to generate parameter sets which is fed to a variant of the road load equation. Modeled road load is then compared to measured load to evaluate the probability of the parameter set. Acceptance of a proposed parameter set is determined using the probability ratio to the currentmore » state, so that the chain history will give a distribution of parameter sets. Compared to a single value, a distribution of possible values provides information on the quality of estimates and the range of possible parameter values. The method is demonstrated by estimating dynamometer parameters. Results confirm the method's ability to estimate reasonable parameter sets, and indicates an opportunity to increase the certainty of estimates through careful selection or generation of the test drive cycle.« less

Friction Stir Welding in Wrought and Cast Aluminum Alloys: Weld Quality Evaluation and Effects of Processing Parameters on Microstructure and Mechanical Properties

NASA Astrophysics Data System (ADS)

Pan, Yi; Lados, Diana A.

2017-04-01

Friction stir welding (FSW) is a solid-state process widely used for joining similar and dissimilar materials for critical applications in the transportation sector. Understanding the effects of the process on microstructure and mechanical properties is critical in design for structural integrity. In this study, four aluminum alloy systems (wrought 6061-T651 and cast A356, 319, and A390) were processed in both as-fabricated and pre-weld heat-treated (T6) conditions using various processing parameters. The effects of processing and heat treatment on the resulting microstructures, macro-/micro-hardness, and tensile properties were systematically investigated and mechanistically correlated to changes in grain size, characteristic phases, and strengthening precipitates. Tensile tests were performed at room temperature both along and across the welding zones. A new method able to evaluate weld quality (using a weld quality index) was developed based on the stress concentration calculated under tensile loading. Optimum processing parameter domains that provide both defect-free welds and good mechanical properties were determined for each alloy and associated with the thermal history of the process. These results were further related to characteristic microstructural features, which can be used for component design and materials/process optimization.

Quality by design case study: an integrated multivariate approach to drug product and process development.

PubMed

Huang, Jun; Kaul, Goldi; Cai, Chunsheng; Chatlapalli, Ramarao; Hernandez-Abad, Pedro; Ghosh, Krishnendu; Nagi, Arwinder

2009-12-01

To facilitate an in-depth process understanding, and offer opportunities for developing control strategies to ensure product quality, a combination of experimental design, optimization and multivariate techniques was integrated into the process development of a drug product. A process DOE was used to evaluate effects of the design factors on manufacturability and final product CQAs, and establish design space to ensure desired CQAs. Two types of analyses were performed to extract maximal information, DOE effect & response surface analysis and multivariate analysis (PCA and PLS). The DOE effect analysis was used to evaluate the interactions and effects of three design factors (water amount, wet massing time and lubrication time), on response variables (blend flow, compressibility and tablet dissolution). The design space was established by the combined use of DOE, optimization and multivariate analysis to ensure desired CQAs. Multivariate analysis of all variables from the DOE batches was conducted to study relationships between the variables and to evaluate the impact of material attributes/process parameters on manufacturability and final product CQAs. The integrated multivariate approach exemplifies application of QbD principles and tools to drug product and process development.

The impact of new partial AUC parameters for evaluating the bioequivalence of prolonged-release formulations.

PubMed

Boily, Michaël; Dussault, Catherine; Massicotte, Julie; Guibord, Pascal; Lefebvre, Marc

2015-01-23

To demonstrate bioequivalence (BE) between two prolonged-release (PR) drug formulations, single dose studies under fasting and fed state as well as at least one steady-state study are currently required by the European Medicines Agency (EMA). Recently, however, there have been debates regarding the relevance of steady-state studies. New requirements in single-dose investigations have also been suggested by the EMA to address the absence of a parameter that can adequately assess the equivalence of the shape of the curves. In the draft guideline issued in 2013, new partial area under the curve (pAUC) pharmacokinetic (PK) parameters were introduced to that effect. In light of these potential changes, there is a need of supportive clinical evidence to evaluate the impact of pAUCs on the evaluation of BE between PR formulations. In this retrospective analysis, it was investigated whether the newly defined parameters were associated with an increase in discriminatory ability or a change in variability compared to the conventional PK parameters. Among the single dose studies that met the requirements already in place, 20% were found unable to meet the EMA's new requirements in regards to the pAUC PK parameters. When pairing fasting and fed studies for a same formulation, the failure rate increased to 40%. In some cases, due to the high variability of these parameters, an increase of the sample size would be required to prove BE. In other cases however, the pAUC parameters demonstrated a robust ability to detect differences between the shapes of the curves of PR formulations. The present analysis should help to better understand the impact of the upcoming changes in European regulations on PR formulations and in the design of future BE studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Design of a Fission 99 Mo Recovery Process and Implications toward Mo Adsorption Mechanism on Titania and Alumina Sorbents

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

Stepinski, Dominique C.; Youker, Amanda J.; Krahn, Elizabeth O.

2017-03-01

Molybdenum-99 is a parent of the most widely used medical isotope technetium-99m. Proliferation concerns have prompted development of alternative Mo production methods utilizing low enriched uranium. Alumina and titania sorbents were evaluated for separation of Mo from concentrated uranyl nitrate solutions. System, mass transfer, and isotherm parameters were determined to enable design of Mo separation processes under a wide range of conditions. A model-based approach was utilized to design representative commercial-scale column processes. The designs and parameters were verified with bench-scale experiments. The results are essential for design of Mo separation processes from irradiated uranium solutions, selection of support materialmore » and process optimization. Mo uptake studies show that adsorption decreases with increasing concentration of uranyl nitrate; howeveL, examination of Mo adsorption as a function of nitrate ion concentration shows no dependency, indicating that uranium competes with Mo for adsorption sites. These results are consistent with reports indicating that Mo forms inner-sphere complexes with titania and alumina surface groups.« less

Optimal design of focused experiments and surveys

NASA Astrophysics Data System (ADS)

Curtis, Andrew

1999-10-01

Experiments and surveys are often performed to obtain data that constrain some previously underconstrained model. Often, constraints are most desired in a particular subspace of model space. Experiment design optimization requires that the quality of any particular design can be both quantified and then maximized. This study shows how the quality can be defined such that it depends on the amount of information that is focused in the particular subspace of interest. In addition, algorithms are presented which allow one particular focused quality measure (from the class of focused measures) to be evaluated efficiently. A subclass of focused quality measures is also related to the standard variance and resolution measures from linearized inverse theory. The theory presented here requires that the relationship between model parameters and data can be linearized around a reference model without significant loss of information. Physical and financial constraints define the space of possible experiment designs. Cross-well tomographic examples are presented, plus a strategy for survey design to maximize information about linear combinations of parameters such as bulk modulus, κ =λ+ 2μ/3.

DEVELOPMENT AND LABORATORY CHARACTERIZATION OF A PROTOTYPE COARSE PARTICLE CONCENTRATOR FOR INHALATION TOXICOLOGICAL STUDIES. (R825270)

EPA Science Inventory

This paper presents the development and laboratory characterization of a prototype slit nozzle virtual impactor that can be used to concentrate coarse particles. A variety of physical design and flow parameters were evaluated including different acceleration and collection sli...

Operation, Maintenance and Performance Evaluation of the Potomac Estuary Experimental Water Treatment Plant. Executive Summary.

DTIC Science & Technology

1983-09-01

tion of appropriate isotherm and rate model parameters for TOC and one SOC. - Evaluation of GAC design alternatives at different treatment...permits an estimate of corrosion rates , based on weight loss of pipe inserts maintained in continuous contact with the finished water. With respect to the...coagulation, sedimentation, recarbonation, gravity filtration, GAC adsorption at twice the contact time, ozone and chloramine for final disinfection. An

Evaluation program for secondary spacecraft cells. Initial evaluation tests of General Electric Company 4.0 ampere-hour nickel-cadmium spacecraft cells for the AMPTE satellite program

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1984-01-01

Cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open circuit voltage above 1.150 volts during the internal short test are addressed. The Active Magnetic Particle Tracer Explorer (AMPTE) cell design was characterized and the effects of specific mission parameters on cell life were demonstrated.

Non-destructive evaluation of composite materials using ultrasound

NASA Technical Reports Server (NTRS)

Miller, J. G.

1984-01-01

Investigation of the nondestructive evaluation of advanced composite-laminates is summarized. Indices derived from the measurement of fundamental acoustic parameters are used in order to quantitatively estimate the local material properties of the laminate. The following sections describe ongoing studies of phase insensitive attenuation measurements, and discuss several phenomena which influences the previously reported technique of polar backscatter. A simple and effective programmable gate circuit designed for use in estimating attenuation from backscatter is described.

Time-saving design of experiment protocol for optimization of LC-MS data processing in metabolomic approaches.

PubMed

Zheng, Hong; Clausen, Morten Rahr; Dalsgaard, Trine Kastrup; Mortensen, Grith; Bertram, Hanne Christine

2013-08-06

We describe a time-saving protocol for the processing of LC-MS-based metabolomics data by optimizing parameter settings in XCMS and threshold settings for removing noisy and low-intensity peaks using design of experiment (DoE) approaches including Plackett-Burman design (PBD) for screening and central composite design (CCD) for optimization. A reliability index, which is based on evaluation of the linear response to a dilution series, was used as a parameter for the assessment of data quality. After identifying the significant parameters in the XCMS software by PBD, CCD was applied to determine their values by maximizing the reliability and group indexes. Optimal settings by DoE resulted in improvements of 19.4% and 54.7% in the reliability index for a standard mixture and human urine, respectively, as compared with the default setting, and a total of 38 h was required to complete the optimization. Moreover, threshold settings were optimized by using CCD for further improvement. The approach combining optimal parameter setting and the threshold method improved the reliability index about 9.5 times for a standards mixture and 14.5 times for human urine data, which required a total of 41 h. Validation results also showed improvements in the reliability index of about 5-7 times even for urine samples from different subjects. It is concluded that the proposed methodology can be used as a time-saving approach for improving the processing of LC-MS-based metabolomics data.

Theoretical Tools and Software for Modeling, Simulation and Control Design of Rocket Test Facilities

NASA Technical Reports Server (NTRS)

Richter, Hanz

2004-01-01

A rocket test stand and associated subsystems are complex devices whose operation requires that certain preparatory calculations be carried out before a test. In addition, real-time control calculations must be performed during the test, and further calculations are carried out after a test is completed. The latter may be required in order to evaluate if a particular test conformed to specifications. These calculations are used to set valve positions, pressure setpoints, control gains and other operating parameters so that a desired system behavior is obtained and the test can be successfully carried out. Currently, calculations are made in an ad-hoc fashion and involve trial-and-error procedures that may involve activating the system with the sole purpose of finding the correct parameter settings. The goals of this project are to develop mathematical models, control methodologies and associated simulation environments to provide a systematic and comprehensive prediction and real-time control capability. The models and controller designs are expected to be useful in two respects: 1) As a design tool, a model is the only way to determine the effects of design choices without building a prototype, which is, in the context of rocket test stands, impracticable; 2) As a prediction and tuning tool, a good model allows to set system parameters off-line, so that the expected system response conforms to specifications. This includes the setting of physical parameters, such as valve positions, and the configuration and tuning of any feedback controllers in the loop.

Algorithmic Mechanism Design of Evolutionary Computation.

PubMed

Pei, Yan

2015-01-01

We consider algorithmic design, enhancement, and improvement of evolutionary computation as a mechanism design problem. All individuals or several groups of individuals can be considered as self-interested agents. The individuals in evolutionary computation can manipulate parameter settings and operations by satisfying their own preferences, which are defined by an evolutionary computation algorithm designer, rather than by following a fixed algorithm rule. Evolutionary computation algorithm designers or self-adaptive methods should construct proper rules and mechanisms for all agents (individuals) to conduct their evolution behaviour correctly in order to definitely achieve the desired and preset objective(s). As a case study, we propose a formal framework on parameter setting, strategy selection, and algorithmic design of evolutionary computation by considering the Nash strategy equilibrium of a mechanism design in the search process. The evaluation results present the efficiency of the framework. This primary principle can be implemented in any evolutionary computation algorithm that needs to consider strategy selection issues in its optimization process. The final objective of our work is to solve evolutionary computation design as an algorithmic mechanism design problem and establish its fundamental aspect by taking this perspective. This paper is the first step towards achieving this objective by implementing a strategy equilibrium solution (such as Nash equilibrium) in evolutionary computation algorithm.

Algorithmic Mechanism Design of Evolutionary Computation

PubMed Central

2015-01-01

We consider algorithmic design, enhancement, and improvement of evolutionary computation as a mechanism design problem. All individuals or several groups of individuals can be considered as self-interested agents. The individuals in evolutionary computation can manipulate parameter settings and operations by satisfying their own preferences, which are defined by an evolutionary computation algorithm designer, rather than by following a fixed algorithm rule. Evolutionary computation algorithm designers or self-adaptive methods should construct proper rules and mechanisms for all agents (individuals) to conduct their evolution behaviour correctly in order to definitely achieve the desired and preset objective(s). As a case study, we propose a formal framework on parameter setting, strategy selection, and algorithmic design of evolutionary computation by considering the Nash strategy equilibrium of a mechanism design in the search process. The evaluation results present the efficiency of the framework. This primary principle can be implemented in any evolutionary computation algorithm that needs to consider strategy selection issues in its optimization process. The final objective of our work is to solve evolutionary computation design as an algorithmic mechanism design problem and establish its fundamental aspect by taking this perspective. This paper is the first step towards achieving this objective by implementing a strategy equilibrium solution (such as Nash equilibrium) in evolutionary computation algorithm. PMID:26257777

General principles of control method of passenger car bodies bending vibration parameters

NASA Astrophysics Data System (ADS)

Skachkov, A. N.; Samoshkin, S. L.; Korshunov, S. D.; Kobishchanov, V. V.; Antipin, D. Ya

2018-03-01

Weight reduction of passenger cars is a promising direction of reducing the cost of their production and increasing transportation profitability. One way to reduce the weight of passenger cars is the lightweight metal body design by means of using of high-strength aluminum alloys, low-alloy and stainless steels. However, it has been found that the limit of the lightweight metal body design is not determined by the total mode of deformation, but its flexural rigidity, as the latter influences natural frequencies of body bending vibrations. With the introduction of mandatory certification for compliance with the Customs Union technical regulations, the following index was confirmed: “first natural frequency of body bending vibrations in the vertical plane”. This is due to the fact that vibration, noise and car motion depend on this index. To define the required indexes, the principles of the control method of bending vibration parameters of passenger car bodies are proposed in this paper. This method covers all stages of car design – development of design documentation, manufacturing and testing experimental and pilot models, launching the production. The authors also developed evaluation criteria and the procedure of using the results for introduction of control method of bending vibration parameters of passenger car bodies.

Optimal supplementary frequency controller design using the wind farm frequency model and controller parameters stability region.

PubMed

Toulabi, Mohammadreza; Bahrami, Shahab; Ranjbar, Ali Mohammad

2018-03-01

In most of the existing studies, the frequency response in the variable speed wind turbines (VSWTs) is simply realized by changing the torque set-point via appropriate inputs such as frequency deviations signal. However, effective dynamics and systematic process design have not been comprehensively discussed yet. Accordingly, this paper proposes a proportional-derivative frequency controller and investigates its performance in a wind farm consisting of several VSWTs. A band-pass filter is deployed before the proposed controller to avoid responding to either steady state frequency deviations or high rate of change of frequency. To design the controller, the frequency model of the wind farm is first characterized. The proposed controller is then designed based on the obtained open loop system. The stability region associated with the controller parameters is analytically determined by decomposing the closed-loop system's characteristic polynomial into the odd and even parts. The performance of the proposed controller is evaluated through extensive simulations in MATLAB/Simulink environment in a power system comprising a high penetration of VSWTs equipped with the proposed controller. Finally, based on the obtained feasible area and appropriate objective function, the optimal values associated with the controller parameters are determined using the genetic algorithm (GA). Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Distributed sensor architecture for intelligent control that supports quality of control and quality of service.

PubMed

Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Simarro, Raúl; Benet, Ginés

2015-02-25

This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems.

Distributed Sensor Architecture for Intelligent Control that Supports Quality of Control and Quality of Service

PubMed Central

Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Simarro, Raúl; Benet, Ginés

2015-01-01

This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems. PMID:25723145

The optimization of wireless power transmission: design and realization.

PubMed

Jia, Zhiwei; Yan, Guozheng; Liu, Hua; Wang, Zhiwu; Jiang, Pingping; Shi, Yu

2012-09-01

A wireless power transmission system is regarded as a practical way of solving power-shortage problems in multifunctional active capsule endoscopes. The uniformity of magnetic flux density, frequency stability and orientation stability are used to evaluate power transmission stability, taking into consideration size and safety constraints. Magnetic field safety and temperature rise are also considered. Test benches are designed to measure the relevent parameters. Finally, a mathematical programming model in which these constraints are considered is proposed to improve transmission efficiency. To verify the feasibility of the proposed method, various systems for a wireless active capsule endoscope are designed and evaluated. The optimal power transmission system has the capability to supply continuously at least 500 mW of power with a transmission efficiency of 4.08%. The example validates the feasibility of the proposed method. Introduction of novel designs enables further improvement of this method. Copyright © 2012 John Wiley & Sons, Ltd.

Conceptual design and cost analysis of hydraulic output unit for 15 kW free-piston Stirling engine

NASA Technical Reports Server (NTRS)

White, M. A.

1982-01-01

A long-life hydraulic converter with unique features was conceptually designed to interface with a specified 15 kW(e) free-piston Stirling engine in a solar thermal dish application. Hydraulic fluid at 34.5 MPa (5000 psi) is produced to drive a conventional hydraulic motor and rotary alternator. Efficiency of the low-maintenance converter design was calculated at 93.5% for a counterbalanced version and 97.0% without the counterbalance feature. If the converter were coupled to a Stirling engine with design parameters more typcial of high-technology Stirling engines, counterbalanced converter efficiency could be increased to 99.6%. Dynamic computer simulation studies were conducted to evaluate performance and system sensitivities. Production costs of the complete Stirling hydraulic/electric power system were evaluated at $6506 which compared with $8746 for an alternative Stirling engine/linear alternator system.

Enhanced Attitude Control Experiment for SSTI Lewis Spacecraft

NASA Technical Reports Server (NTRS)

Maghami, Peoman G.

1997-01-01

The enhanced attitude control system experiment is a technology demonstration experiment on the NASA's small spacecraft technology initiative program's Lewis spacecraft to evaluate advanced attitude control strategies. The purpose of the enhanced attitude control system experiment is to evaluate the feasibility of designing and implementing robust multi-input/multi-output attitude control strategies for enhanced pointing performance of spacecraft to improve the quality of the measurements of the science instruments. Different control design strategies based on modern and robust control theories are being considered for the enhanced attitude control system experiment. This paper describes the experiment as well as the design and synthesis of a mixed H(sub 2)/H(sub infinity) controller for attitude control. The control synthesis uses a nonlinear programming technique to tune the controller parameters and impose robustness and performance constraints. Simulations are carried out to demonstrate the feasibility of the proposed attitude control design strategy. Introduction

A robust approach to optimal matched filter design in ultrasonic non-destructive evaluation (NDE)

NASA Astrophysics Data System (ADS)

Li, Minghui; Hayward, Gordon

2017-02-01

The matched filter was demonstrated to be a powerful yet efficient technique to enhance defect detection and imaging in ultrasonic non-destructive evaluation (NDE) of coarse grain materials, provided that the filter was properly designed and optimized. In the literature, in order to accurately approximate the defect echoes, the design utilized the real excitation signals, which made it time consuming and less straightforward to implement in practice. In this paper, we present a more robust and flexible approach to optimal matched filter design using the simulated excitation signals, and the control parameters are chosen and optimized based on the real scenario of array transducer, transmitter-receiver system response, and the test sample, as a result, the filter response is optimized and depends on the material characteristics. Experiments on industrial samples are conducted and the results confirm the great benefits of the method.

An Extreme Meteorological Events Analysis For Nuclear Power Plant (NPP) Siting Project at Bangka Island, Indonesia

NASA Astrophysics Data System (ADS)

Septiadi, Deni; S, Yarianto Sugeng B.; Sriyana; Anzhar, Kurnia; Suntoko, Hadi

2018-03-01

The potential sources of meteorological phenomena in Nuclear Power Plant (NPP) area of interest are identified and the extreme values of the possible resulting hazards associated which such phenomena are evaluated to derive the appropriate design bases for the NPP. The appropriate design bases shall be determined according to the Nuclear Energy Regulatory Agency (Bapeten) applicable regulations, which presently do not indicate quantitative criteria for purposes of determining the design bases for meteorological hazards. These meteorological investigations are also carried out to evaluate the regional and site specific meteorological parameters which affect the transport and dispersion of radioactive effluents on the environment of the region around the NPP site. The meteorological hazards are to be monitored and assessed periodically over the lifetime of the plant to ensure that consistency with the design assumptions is maintained throughout the full lifetime of the facility.

Design and evaluation of a GaAs MMIC X-band active RC quadrature power divider

NASA Astrophysics Data System (ADS)

Henkus, J. C.

1991-03-01

The design and evaluation of a GaAs MMIC (Microwave Monolithic Integrated Circuit) X-band active RC Quadrature Power Divider (QPD) is addressed. This QPD can be used as part of a vector modulator. The chosen QPD topology consists of two active first order RC all pass networks and was converted into an MMIC design. The design is completely symmetrical except for two key resistors. On-wafer S parameter measurements were carried out; a special probe head configuration was composed in order to avoid measurement accuracy degradation associated with the reversal of the active output of the QPD. The measured nominal RF behavior of the chips complies with the simulated behavior to a very high degree. The optical, DC, and RF yield is very large (97, 83, and 74 percent respectively). A modification to Takashi's all pass network was proposed which offers gain/frequency slope control and compensation ability.

Design and fabrication of a prototype for an automatic transport system for transferring human and other wastes to an incinerator unit onboard spacecraft, phase A

NASA Technical Reports Server (NTRS)

Labak, L. J.; Remus, G. A.; Mansnerus, R.

1971-01-01

Three transport system concepts were experimentally evaluated for transferring human and nonhuman wastes from a collection site to an incineration unit onboard spacecraft. The operating parameters, merits, and shortcomings of a porous-pneumatic, nozzle-pneumatic, and a mechanical screw-feed system were determined. An analysis of the test data was made and a preliminary design of two prototype systems was prepared.

The 1981 NASA/ASEE Summer Faculty Fellowship Program: Research reports

NASA Technical Reports Server (NTRS)

Karr, G. R.; Dozier, J. B.; Kent, M. I.; Barfield, B. F.

1982-01-01

Research reports related to spacecraft industry technological advances, requirements, and applications were considered. Some of the topic areas addressed were: (1) Fabrication, evaluation, and use of high performance composites and ceramics, (2) antenna designs, (3) electronics and microcomputer applications and mathematical modeling and programming techniques, (4) design, fabrication, and failure detection methods for structural materials, components, and total systems, and (5) chemical studies of bindary organic mixtures and polymer synthesis. Space environment parameters were also discussed.

Design of helicopter rotor blades with actuators made of a piezomacrofiber composite

NASA Astrophysics Data System (ADS)

Glukhikh, S.; Barkanov, E.; Kovalev, A.; Masarati, P.; Morandini, M.; Riemenschneider, J.; Wierach, P.

2008-01-01

For reducing the vibration and noise of helicopter rotor blades, the method of their controlled twisting by using built-in deformation actuators is employed. In this paper, the influence of various design parameters of the blades, including the location of actuators made of a piezomacrofiber material, on the twist angle is evaluated. The results of a parametric analysis performed allowed us to refine the statement of an optimization problem for the rotor blades.

Periapical and endodontic status scale based on periapical bone lesions and endodontic treatment quality evaluation using cone-beam computed tomography.

PubMed

Venskutonis, Tadas; Plotino, Gianluca; Tocci, Luigi; Gambarini, Gianluca; Maminskas, Julius; Juodzbalys, Gintaras

2015-02-01

The purpose of this study was to present a new periapical and endodontic status scale (PESS) that is based on the complex periapical index (COPI), which was designed for the identification and classification of periapical bone lesions in cases of apical periodontitis, and the endodontically treated tooth index, which was designed for endodontic treatment quality evaluation by means of cone-beam computed tomographic (CBCT) analysis. Periapical and endodontic status parameters were selected from the already known indexes and scientific literature for radiologic evaluation. Radiographic images (CBCT imaging, digital orthopantomography [DOR], and digital periapical radiography) from 55 patients were analyzed. All parameters were evaluated on CBCT, DOR, and digital periapical radiographic images by 2 external observers. The statistical analysis was performed with software SPSS version 19.0 (SPSS Inc, Chicago, IL). Chi-square tests were used to compare frequencies of qualitative variables. The level of significance was set at P ≤ .05. Overall intraobserver and interobserver agreements were very good and good, respectively. CBCT analysis found more lesions and lesions of bigger dimension (P < .001). CBCT imaging was also superior in locating lesions in the apical part on the side compared with DOR and in the diagnosis of cortical bone destruction compared with both methods (P < .001). Through CBCT analysis, more root canals and more canals associated with lesions were found. The most informative and reproducible periapical and endodontic status parameters were selected, and a new PESS was proposed. The classification proposed in the present study seems to be reproducible and objective and adds helpful information with respect to the existing indexes. Future studies need to be conducted to validate PESS. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Research on Product Conceptual Design Based on Integrated of TRIZ and HOQ

NASA Astrophysics Data System (ADS)

Xie, Jianmin; Tang, Xiaowo; Shao, Yunfei

The conceptual design determines the success of the final product quality and competition of market. The determination of design parameters and the effective method to resolve parameters contradiction are the key to success. In this paper, the concept of HOQ products designed to determine the parameters, then using the TRIZ contradiction matrix and inventive principles of design parameters to solve the problem of contradictions. Facts have proved that the effective method is to obtain the product concept design parameters and to resolve contradictions line parameters.

Neuroeconomics and public health

PubMed Central

Larsen, Torben

2010-01-01

Objective To design an economic evaluation strategy for general health promotion projects. Method Identification of key parameters of behavioral health from neuroeconomic studies. Results The Frontal Power of Concentration (C) is a quadripartite executive integrator depending on four key parameters: 1) The Limbic system originating ambivalent emotions (L). 2) Volition in the Prefrontal Cortex (c) controlling cognitive prediction and emotions with a view on Frontopolar long-term goals. 3) Semantic memories in the Temporal lobe (R). 4) An intuitive visuospatial sketchpad in the Parietal lobe (I). C aiming to minimize error between preferences and predictions is directly determined by the following equation including I as a stochastic knowledge component: C =Rc2/L +εI→ 1 Discussion All of the parameters of C are object to improvement by training: Cognitive predictions are improved by open-mindedness towards feedback (R).The effect of emotional regrets is reinforced by an appropriate level of fitness (c, L).Our imagination may be unfolded by in-depth-relaxation-procedures and visualization (I). Conclusion Economic evaluation of general public health should focus on the subset of separate and integrated interventions that directly affect the parameters of Formula C in individuals.

Compressed Sensing for Metrics Development

NASA Astrophysics Data System (ADS)

McGraw, R. L.; Giangrande, S. E.; Liu, Y.

2012-12-01

Models by their very nature tend to be sparse in the sense that they are designed, with a few optimally selected key parameters, to provide simple yet faithful representations of a complex observational dataset or computer simulation output. This paper seeks to apply methods from compressed sensing (CS), a new area of applied mathematics currently undergoing a very rapid development (see for example Candes et al., 2006), to FASTER needs for new approaches to model evaluation and metrics development. The CS approach will be illustrated for a time series generated using a few-parameter (i.e. sparse) model. A seemingly incomplete set of measurements, taken at a just few random sampling times, is then used to recover the hidden model parameters. Remarkably there is a sharp transition in the number of required measurements, beyond which both the model parameters and time series are recovered exactly. Applications to data compression, data sampling/collection strategies, and to the development of metrics for model evaluation by comparison with observation (e.g. evaluation of model predictions of cloud fraction using cloud radar observations) are presented and discussed in context of the CS approach. Cited reference: Candes, E. J., Romberg, J., and Tao, T. (2006), Robust uncertainty principles: Exact signal reconstruction from highly incomplete frequency information, IEEE Transactions on Information Theory, 52, 489-509.

[Assessment in Medical Education].

PubMed

Ramírez, Martha Delgado; Gómez-Restrepo, Carlos

2012-01-01

The assessment of medical education is fundamental for proper feedback and evaulation of students. The overall purpose of the evaluation is numerically and formatively revised. The suggested evaluation processes is described taking into account the Miller competence pyramid as a tool for designing evaluations and concepts of validity and reproducibility in assessments. The utility of student and the teacher is also raised. The issue of assessment should leave the knowledge parameters that are usually used. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Design, Development, and Testing of a Compound Wing V/TOL small UAS

NASA Technical Reports Server (NTRS)

Logan, Michael J.; Vranas, Thomas L.

2015-01-01

This paper discusses the development and testing of an innovative small UAS (Unmanned Aircraft System). The design of the vehicle was driven by the need to both have long endurance yet still have the convenience of V/TOL (Vertical Take-Off and Landing) operation. The paper discusses some of the design considerations and configurations evaluated in searching for a configuration that met the demanding mission requirements. The paper also discusses some aspects of the compound wing and experimental testing conducted to discern the optimum parameters for the wing's design. The paper discusses the results of the preliminary flight testing and outlines further research to be conducted.

Application of a Computer Model to Various Specifications of Fuel Injection System for DI Diesel Engines

NASA Astrophysics Data System (ADS)

Yamanishi, Manabu

A combined experimental and computational investigation was performed in order to evaluate the effects of various design parameters of an in-line injection pump on the nozzle exit characteristics for DI diesel engines. Measurements of the pump chamber pressure and the delivery valve lift were included for validation by using specially designed transducers installed inside the pump. The results confirm that the simulation model is capable of predicting the pump operation for all the different designs investigated pump operating conditions. Following the successful validation of this model, parametric studies were performed which allow for improved fuel injection system design.

Material, process, and product design of thermoplastic composite materials

NASA Astrophysics Data System (ADS)

Dai, Heming

Thermoplastic composites made of polypropylene (PP) and E-glass fibers were investigated experimentally as well as theoretically for two new classes of product designs. The first application was for reinforcement of wood. Commingled PP/glass yarn was consolidated and bonded on wood panel using a tie layer. The processing parameters, including temperature, pressure, heating time, cooling time, bonding strength, and bending strength were tested experimentally and evaluated analytically. The thermoplastic adhesive interface was investigated with environmental scanning electron microscopy. The wood/composite structural design was optimized and evaluated using a Graphic Method. In the second application, we evaluated use of thermoplastic composites for explosion containment in an arrester. PP/glass yarn was fabricated in a sleeve form and wrapped around the arrester. After consolidation, the flexible composite sleeve forms a solid composite shell. The composite shell acts as a protection layer in a surge test to contain the fragments of the arrester. The manufacturing process for forming the composite shell was designed. Woven, knitted, and braided textile composite shells made of commingled PP/glass yarn were tested and evaluated. Mechanical performance of the woven, knitted, and braided composite shells was examined analytically. The theoretical predictions were used to verify the experimental results.

Automated optimization techniques for aircraft synthesis

NASA Technical Reports Server (NTRS)

Vanderplaats, G. N.

1976-01-01

Application of numerical optimization techniques to automated conceptual aircraft design is examined. These methods are shown to be a general and efficient way to obtain quantitative information for evaluating alternative new vehicle projects. Fully automated design is compared with traditional point design methods and time and resource requirements for automated design are given. The NASA Ames Research Center aircraft synthesis program (ACSYNT) is described with special attention to calculation of the weight of a vehicle to fly a specified mission. The ACSYNT procedures for automatically obtaining sensitivity of the design (aircraft weight, performance and cost) to various vehicle, mission, and material technology parameters are presented. Examples are used to demonstrate the efficient application of these techniques.

Closed-loop stability of linear quadratic optimal systems in the presence of modeling errors

NASA Technical Reports Server (NTRS)

Toda, M.; Patel, R.; Sridhar, B.

1976-01-01

The well-known stabilizing property of linear quadratic state feedback design is utilized to evaluate the robustness of a linear quadratic feedback design in the presence of modeling errors. Two general conditions are obtained for allowable modeling errors such that the resulting closed-loop system remains stable. One of these conditions is applied to obtain two more particular conditions which are readily applicable to practical situations where a designer has information on the bounds of modeling errors. Relations are established between the allowable parameter uncertainty and the weighting matrices of the quadratic performance index, thereby enabling the designer to select appropriate weighting matrices to attain a robust feedback design.

Quantitative EEG features selection in the classification of attention and response control in the children and adolescents with attention deficit hyperactivity disorder.

PubMed

Bashiri, Azadeh; Shahmoradi, Leila; Beigy, Hamid; Savareh, Behrouz A; Nosratabadi, Masood; N Kalhori, Sharareh R; Ghazisaeedi, Marjan

2018-06-01

Quantitative EEG gives valuable information in the clinical evaluation of psychological disorders. The purpose of the present study is to identify the most prominent features of quantitative electroencephalography (QEEG) that affect attention and response control parameters in children with attention deficit hyperactivity disorder. The QEEG features and the Integrated Visual and Auditory-Continuous Performance Test ( IVA-CPT) of 95 attention deficit hyperactivity disorder subjects were preprocessed by Independent Evaluation Criterion for Binary Classification. Then, the importance of selected features in the classification of desired outputs was evaluated using the artificial neural network. Findings uncovered the highest rank of QEEG features in each IVA-CPT parameters related to attention and response control. Using the designed model could help therapists to determine the existence or absence of defects in attention and response control relying on QEEG.

Automated Design Space Exploration with Aspen

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

Spafford, Kyle L.; Vetter, Jeffrey S.

Architects and applications scientists often use performance models to explore a multidimensional design space of architectural characteristics, algorithm designs, and application parameters. With traditional performance modeling tools, these explorations forced users to first develop a performance model and then repeatedly evaluate and analyze the model manually. These manual investigations proved laborious and error prone. More importantly, the complexity of this traditional process often forced users to simplify their investigations. To address this challenge of design space exploration, we extend our Aspen (Abstract Scalable Performance Engineering Notation) language with three new language constructs: user-defined resources, parameter ranges, and a collection ofmore » costs in the abstract machine model. Then, we use these constructs to enable automated design space exploration via a nonlinear optimization solver. We show how four interesting classes of design space exploration scenarios can be derived from Aspen models and formulated as pure nonlinear programs. The analysis tools are demonstrated using examples based on Aspen models for a three-dimensional Fast Fourier Transform, the CoMD molecular dynamics proxy application, and the DARPA Streaming Sensor Challenge Problem. Our results show that this approach can compose and solve arbitrary performance modeling questions quickly and rigorously when compared to the traditional manual approach.« less

Automated Design Space Exploration with Aspen

DOE PAGES

Spafford, Kyle L.; Vetter, Jeffrey S.

2015-01-01

Architects and applications scientists often use performance models to explore a multidimensional design space of architectural characteristics, algorithm designs, and application parameters. With traditional performance modeling tools, these explorations forced users to first develop a performance model and then repeatedly evaluate and analyze the model manually. These manual investigations proved laborious and error prone. More importantly, the complexity of this traditional process often forced users to simplify their investigations. To address this challenge of design space exploration, we extend our Aspen (Abstract Scalable Performance Engineering Notation) language with three new language constructs: user-defined resources, parameter ranges, and a collection ofmore » costs in the abstract machine model. Then, we use these constructs to enable automated design space exploration via a nonlinear optimization solver. We show how four interesting classes of design space exploration scenarios can be derived from Aspen models and formulated as pure nonlinear programs. The analysis tools are demonstrated using examples based on Aspen models for a three-dimensional Fast Fourier Transform, the CoMD molecular dynamics proxy application, and the DARPA Streaming Sensor Challenge Problem. Our results show that this approach can compose and solve arbitrary performance modeling questions quickly and rigorously when compared to the traditional manual approach.« less

Parametric study of closed wet cooling tower thermal performance

NASA Astrophysics Data System (ADS)

Qasim, S. M.; Hayder, M. J.

2017-08-01

The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

Performance verification and system parameter identification of spacecraft tape recorder control servo

NASA Technical Reports Server (NTRS)

Mukhopadhyay, A. K.

1979-01-01

Design adequacy of the lead-lag compensator of the frequency loop, accuracy checking of the analytical expression for the electrical motor transfer function, and performance evaluation of the speed control servo of the digital tape recorder used on-board the 1976 Viking Mars Orbiters and Voyager 1977 Jupiter-Saturn flyby spacecraft are analyzed. The transfer functions of the most important parts of a simplified frequency loop used for test simulation are described and ten simulation cases are reported. The first four of these cases illustrate the method of selecting the most suitable transfer function for the hysteresis synchronous motor, while the rest verify and determine the servo performance parameters and alternative servo compensation schemes. It is concluded that the linear methods provide a starting point for the final verification/refinement of servo design by nonlinear time response simulation and that the variation of the parameters of the static/dynamic Coulomb friction is as expected in a long-life space mission environment.

AVR Microcontroller-based automated technique for analysis of DC motors

NASA Astrophysics Data System (ADS)

Kaur, P.; Chatterji, S.

2014-01-01

This paper provides essential information on the development of a 'dc motor test and analysis control card' using AVR series ATMega32 microcontroller. This card can be interfaced to PC and calculates parameters like motor losses, efficiency and plot characteristics for dc motors. Presently, there are different tests and methods available to evaluate motor parameters, but a single and universal user-friendly automated set-up has been discussed in this paper. It has been accomplished by designing a data acquisition and SCR bridge firing hardware based on AVR ATMega32 microcontroller. This hardware has the capability to drive the phase-controlled rectifiers and acquire real-time values of current, voltage, temperature and speed of motor. Various analyses feasible with the designed hardware are of immense importance for dc motor manufacturers and quality-sensitive users. Authors, through this paper aim to provide details of this AVR-based hardware which can be used for dc motor parameter analysis and also for motor control applications.

Performance evaluation of matrix gradient coils.

PubMed

Jia, Feng; Schultz, Gerrit; Testud, Frederik; Welz, Anna Masako; Weber, Hans; Littin, Sebastian; Yu, Huijun; Hennig, Jürgen; Zaitsev, Maxim

2016-02-01

In this paper, we present a new performance measure of a matrix coil (also known as multi-coil) from the perspective of efficient, local, non-linear encoding without explicitly considering target encoding fields. An optimization problem based on a joint optimization for the non-linear encoding fields is formulated. Based on the derived objective function, a figure of merit of a matrix coil is defined, which is a generalization of a previously known resistive figure of merit for traditional gradient coils. A cylindrical matrix coil design with a high number of elements is used to illustrate the proposed performance measure. The results are analyzed to reveal novel features of matrix coil designs, which allowed us to optimize coil parameters, such as number of coil elements. A comparison to a scaled, existing multi-coil is also provided to demonstrate the use of the proposed performance parameter. The assessment of a matrix gradient coil profits from using a single performance parameter that takes the local encoding performance of the coil into account in relation to the dissipated power.

Biodiesel production from Spirulina microalgae feedstock using direct transesterification near supercritical methanol condition.

PubMed

Mohamadzadeh Shirazi, Hamed; Karimi-Sabet, Javad; Ghotbi, Cyrus

2017-09-01

Microalgae as a candidate for production of biodiesel, possesses a hard cell wall that prevents intracellular lipids leaving out from the cells. Direct or in situ supercritical transesterification has the potential for destruction of microalgae hard cell wall and conversion of extracted lipids to biodiesel that consequently reduces the total energy consumption. Response surface methodology combined with central composite design was applied to investigate process parameters including: Temperature, Time, Methanol-to-dry algae, Hexane-to-dry algae, and Moisture content. Thirty-two experiments were designed and performed in a batch reactor, and biodiesel efficiency between 0.44% and 99.32% was obtained. According to fatty acid methyl ester yields, a quadratic experimental model was adjusted and the significance of parameters was evaluated using analysis of variance (ANOVA). Effects of single and interaction parameters were also interpreted. In addition, the effect of supercritical process on the ultrastructure of microalgae cell wall using scanning electron spectrometry (SEM) was surveyed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infography use to requirements specification for the design of the building

NASA Astrophysics Data System (ADS)

Losev, Konstantin; Sinenko, Sergey

2017-10-01

The study contributes to a growing body of research Transport infrastructure in a construction object life cycle management and presents areas in which further investigation is needed. The object of study are Railway buildings and structures and the Employer’s information requirements (EIR) for design of individual residential building. The task of the study was to determine necessary and sufficient scope of parameters which contained in inforaphic form of EIR comparing with traditional text form of EIR. Also, the task was to determine what categories of the traditional EIR are transferred to an infographic representation form and what categories are ignored in case of a relatively low complexity building. Methods that have been used in the study were infographical representation of text and further expert evaluation. Conclusions of the study present the necessary and sufficient scope of parameters for inforaphic form of EIR, the relations between infographic parameters and categories of the EIR traditional form and subcategories of the traditional EIR that are ignored in case of a relatively low complexity building.

Collocation and Pattern Recognition Effects on System Failure Remediation

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.; Press, Hayes N.

2007-01-01

Previous research found that operators prefer to have status, alerts, and controls located on the same screen. Unfortunately, that research was done with displays that were not designed specifically for collocation. In this experiment, twelve subjects evaluated two displays specifically designed for collocating system information against a baseline that consisted of dial status displays, a separate alert area, and a controls panel. These displays differed in the amount of collocation, pattern matching, and parameter movement compared to display size. During the data runs, subjects kept a randomly moving target centered on a display using a left-handed joystick and they scanned system displays to find a problem in order to correct it using the provided checklist. Results indicate that large parameter movement aided detection and then pattern recognition is needed for diagnosis but the collocated displays centralized all the information subjects needed, which reduced workload. Therefore, the collocated display with large parameter movement may be an acceptable display after familiarization because of the possible pattern recognition developed with training and its use.

Dimensionless Analysis and Mathematical Modeling of Electromagnetic Levitation (EML) of Metals

NASA Astrophysics Data System (ADS)

Gao, Lei; Shi, Zhe; Li, Donghui; Yang, Yindong; Zhang, Guifang; McLean, Alexander; Chattopadhyay, Kinnor

2016-02-01

Electromagnetic levitation (EML), a contactless metal melting method, can be used to produce ultra-pure metals and alloys. In the EML process, the levitation force exerted on the droplet is of paramount importance and is affected by many parameters. In this paper, the relationship between levitation force and parameters affecting the levitation process were investigated by dimensionless analysis. The general formula developed by dimensionless analysis was tested and evaluated by numerical modeling. This technique can be employed to design levitation systems for a variety of materials.

MaRIE Undulator & XFEL Systems

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

Nguyen, Dinh Cong; Marksteiner, Quinn R.; Anisimov, Petr Mikhaylovich

The 22 slides in this presentation treat the subject under the following headings: MaRIE XFEL Performance Parameters, Input Electron Beam Parameters, Undulator Design, Genesis Simulations, Risks, and Summary It is concluded that time-dependent Genesis simulations show the MaRIE XFEL can deliver the number of photons within the required bandwidth, provided a number of assumptions are met; the highest risks are associated with the electron beam driving the XFEL undulator; and risks associated with the undulator and/or distributed seeding technique may be evaluated or retired by performing early validation experiments.

Model-based optimal design of experiments - semidefinite and nonlinear programming formulations

PubMed Central

Duarte, Belmiro P.M.; Wong, Weng Kee; Oliveira, Nuno M.C.

2015-01-01

We use mathematical programming tools, such as Semidefinite Programming (SDP) and Nonlinear Programming (NLP)-based formulations to find optimal designs for models used in chemistry and chemical engineering. In particular, we employ local design-based setups in linear models and a Bayesian setup in nonlinear models to find optimal designs. In the latter case, Gaussian Quadrature Formulas (GQFs) are used to evaluate the optimality criterion averaged over the prior distribution for the model parameters. Mathematical programming techniques are then applied to solve the optimization problems. Because such methods require the design space be discretized, we also evaluate the impact of the discretization scheme on the generated design. We demonstrate the techniques for finding D–, A– and E–optimal designs using design problems in biochemical engineering and show the method can also be directly applied to tackle additional issues, such as heteroscedasticity in the model. Our results show that the NLP formulation produces highly efficient D–optimal designs but is computationally less efficient than that required for the SDP formulation. The efficiencies of the generated designs from the two methods are generally very close and so we recommend the SDP formulation in practice. PMID:26949279

Model-based optimal design of experiments - semidefinite and nonlinear programming formulations.

PubMed

Duarte, Belmiro P M; Wong, Weng Kee; Oliveira, Nuno M C

2016-02-15

We use mathematical programming tools, such as Semidefinite Programming (SDP) and Nonlinear Programming (NLP)-based formulations to find optimal designs for models used in chemistry and chemical engineering. In particular, we employ local design-based setups in linear models and a Bayesian setup in nonlinear models to find optimal designs. In the latter case, Gaussian Quadrature Formulas (GQFs) are used to evaluate the optimality criterion averaged over the prior distribution for the model parameters. Mathematical programming techniques are then applied to solve the optimization problems. Because such methods require the design space be discretized, we also evaluate the impact of the discretization scheme on the generated design. We demonstrate the techniques for finding D -, A - and E -optimal designs using design problems in biochemical engineering and show the method can also be directly applied to tackle additional issues, such as heteroscedasticity in the model. Our results show that the NLP formulation produces highly efficient D -optimal designs but is computationally less efficient than that required for the SDP formulation. The efficiencies of the generated designs from the two methods are generally very close and so we recommend the SDP formulation in practice.

An approach for cooling by solar energy

NASA Astrophysics Data System (ADS)

Rabeih, S. M.; Wahhab, M. A.; Asfour, H. M.

The present investigation is concerned with the possibility to base the operation of a household refrigerator on solar energy instead of gas fuel. The currently employed heating system is to be replaced by a solar collector with an absorption area of two sq m. Attention is given to the required changes in the generator design, the solar parameters at the location of refrigerator installation, the mathematical approach for the thermal analysis of the solar collector, the development of a computer program for the evaluation of the important parameters, the experimental test rig, and the measurement of the experimental parameters. A description is given of the obtained optimum operating conditions for the considered system.

Solar energy system economic evaluation for IBM System 3, Glendo, Wyoming

NASA Technical Reports Server (NTRS)

1980-01-01

This analysis was based on the technical and economic models in f-chart design procedures with inputs based on the characteristics of the parameters of present worth of system cost over a projected twenty year life: life cycle savings, year of positive savings, and year of payback for the optimized solar energy system at each of the analysis sites. The sensitivity of the economic evaluation to uncertainties in constituent system and economic variables was also investigated.

Design of telehealth trials--introducing adaptive approaches.

PubMed

Law, Lisa M; Wason, James M S

2014-12-01

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

Probabilistic Analysis of Solid Oxide Fuel Cell Based Hybrid Gas Turbine System

NASA Technical Reports Server (NTRS)

Gorla, Rama S. R.; Pai, Shantaram S.; Rusick, Jeffrey J.

2003-01-01

The emergence of fuel cell systems and hybrid fuel cell systems requires the evolution of analysis strategies for evaluating thermodynamic performance. A gas turbine thermodynamic cycle integrated with a fuel cell was computationally simulated and probabilistically evaluated in view of the several uncertainties in the thermodynamic performance parameters. Cumulative distribution functions and sensitivity factors were computed for the overall thermal efficiency and net specific power output due to the uncertainties in the thermodynamic random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design and make it cost effective. The analysis leads to the selection of criteria for gas turbine performance.

Space station thermal control surfaces. [space radiators

NASA Technical Reports Server (NTRS)

Maag, C. R.; Millard, J. M.; Jeffery, J. A.; Scott, R. R.

1979-01-01

Mission planning documents were used to analyze the radiator design and thermal control surface requirements for both space station and 25-kW power module, to analyze the missions, and to determine the thermal control technology needed to satisfy both sets of requirements. Parameters such as thermal control coating degradation, vehicle attitude, self eclipsing, variation in solar constant, albedo, and Earth emission are considered. Four computer programs were developed which provide a preliminary design and evaluation tool for active radiator systems in LEO and GEO. Two programs were developed as general programs for space station analysis. Both types of programs find the radiator-flow solution and evaluate external heat loads in the same way. Fortran listings are included.

Optimal design of disc-type magneto-rheological brake for mid-sized motorcycle: experimental evaluation

NASA Astrophysics Data System (ADS)

Sohn, Jung Woo; Jeon, Juncheol; Nguyen, Quoc Hung; Choi, Seung-Bok

2015-08-01

In this paper, a disc-type magneto-rheological (MR) brake is designed for a mid-sized motorcycle and its performance is experimentally evaluated. The proposed MR brake consists of an outer housing, a rotating disc immersed in MR fluid, and a copper wire coiled around a bobbin to generate a magnetic field. The structural configuration of the MR brake is first presented with consideration of the installation space for the conventional hydraulic brake of a mid-sized motorcycle. The design parameters of the proposed MR brake are optimized to satisfy design requirements such as the braking torque, total mass of the MR brake, and cruising temperature caused by the magnetic-field friction of the MR fluid. In the optimization procedure, the braking torque is calculated based on the Herschel-Bulkley rheological model, which predicts MR fluid behavior well at high shear rate. An optimization tool based on finite element analysis is used to obtain the optimized dimensions of the MR brake. After manufacturing the MR brake, mechanical performances regarding the response time, braking torque and cruising temperature are experimentally evaluated.

Scramjet fuel injector design parameters and considerations: Development of a two-dimensional tangential fuel injector with constant pressure at the flame

NASA Technical Reports Server (NTRS)

Agnone, A. M.

1972-01-01

The factors affecting a tangential fuel injector design for scramjet operation are reviewed and their effect on the efficiency of the supersonic combustion process is evaluated using both experimental data and theoretical predictions. A description of the physical problem of supersonic combustion and method of analysis is followed by a presentation and evaluation of some standard and exotic types of fuel injectors. Engineering fuel injector design criteria and hydrogen ignition schemes are presented along with a cursory review of available experimental data. A two-dimensional tangential fuel injector design is developed using analyses as a guide in evaluating the effects on the combustion process of various initial and boundary conditions including splitter plate thickness, injector wall temperature, pressure gradients, etc. The fuel injector wall geometry is shaped so as to maintain approximately constant pressure at the flame as required by a cycle analysis. A viscous characteristics program which accounts for lateral as well as axial pressure variations due to the mixing and combustion process is used in determining the wall geometry.

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

PubMed

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

2012-08-01

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

Application of quality by design principles to the development and technology transfer of a major process improvement for the manufacture of a recombinant protein.

PubMed

Looby, Mairead; Ibarra, Neysi; Pierce, James J; Buckley, Kevin; O'Donovan, Eimear; Heenan, Mary; Moran, Enda; Farid, Suzanne S; Baganz, Frank

2011-01-01

This study describes the application of quality by design (QbD) principles to the development and implementation of a major manufacturing process improvement for a commercially distributed therapeutic protein produced in Chinese hamster ovary cell culture. The intent of this article is to focus on QbD concepts, and provide guidance and understanding on how the various components combine together to deliver a robust process in keeping with the principles of QbD. A fed-batch production culture and a virus inactivation step are described as representative examples of upstream and downstream unit operations that were characterized. A systematic approach incorporating QbD principles was applied to both unit operations, involving risk assessment of potential process failure points, small-scale model qualification, design and execution of experiments, definition of operating parameter ranges and process validation acceptance criteria followed by manufacturing-scale implementation and process validation. Statistical experimental designs were applied to the execution of process characterization studies evaluating the impact of operating parameters on product quality attributes and process performance parameters. Data from process characterization experiments were used to define the proven acceptable range and classification of operating parameters for each unit operation. Analysis of variance and Monte Carlo simulation methods were used to assess the appropriateness of process design spaces. Successful implementation and validation of the process in the manufacturing facility and the subsequent manufacture of hundreds of batches of this therapeutic protein verifies the approaches taken as a suitable model for the development, scale-up and operation of any biopharmaceutical manufacturing process. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Student Acceptance of the TICCIT System: A Preliminary Study.

ERIC Educational Resources Information Center

Asay, Calvin S.; Schneider, Edward W.

Twenty male and female students from a high school psychology class participated in a formative evaluation of student acceptance and performance with the Primary Instruction Logic of the TICCIT delivery system. A secondary goal was a pilot effort to design a carrel that would optimize certain parameters of the physical/environmental conditions…

40 CFR Appendix A to Subpart K of... - Criteria for evaluating a State's proposed NEPA-Like process

Code of Federal Regulations, 2014 CFR

2014-07-01

... SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2) A...) Present and future conditions; (5) Land use and other social parameters including recreation and open... (residential, commercial, institutional and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart K of... - Criteria for evaluating a State's proposed NEPA-Like process

Code of Federal Regulations, 2011 CFR

2011-07-01

... SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2) A...) Present and future conditions; (5) Land use and other social parameters including recreation and open... (residential, commercial, institutional and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart L - Criteria for Evaluating a State's Proposed NEPA-Like Process

Code of Federal Regulations, 2012 CFR

2012-07-01

... consider: (1) Designation of a study area comparable to the final system; (2) A range of feasible... conditions; (5) Land use and other social parameters including relevant recreation and open-space..., institutional, and industrial) within the project study area; and (8) Other anticipated public works projects...

40 CFR Appendix A to Subpart L - Criteria for Evaluating a State's Proposed NEPA-Like Process

Code of Federal Regulations, 2010 CFR

2010-07-01

... consider: (1) Designation of a study area comparable to the final system; (2) A range of feasible... conditions; (5) Land use and other social parameters including relevant recreation and open-space..., institutional, and industrial) within the project study area; and (8) Other anticipated public works projects...

40 CFR Appendix A to Subpart L of... - Criteria for Evaluating a State's Proposed NEPA-Like Process

Code of Federal Regulations, 2013 CFR

2013-07-01

... the SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2... impacts; (4) Present and future conditions; (5) Land use and other social parameters including relevant... (residential, commercial, institutional, and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart K of... - Criteria for evaluating a State's proposed NEPA-Like process

Code of Federal Regulations, 2012 CFR

2012-07-01

... SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2) A...) Present and future conditions; (5) Land use and other social parameters including recreation and open... (residential, commercial, institutional and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart K of... - Criteria for evaluating a State's proposed NEPA-Like process

Code of Federal Regulations, 2010 CFR

2010-07-01

... SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2) A...) Present and future conditions; (5) Land use and other social parameters including recreation and open... (residential, commercial, institutional and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart K of... - Criteria for evaluating a State's proposed NEPA-Like process

Code of Federal Regulations, 2013 CFR

2013-07-01

... SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2) A...) Present and future conditions; (5) Land use and other social parameters including recreation and open... (residential, commercial, institutional and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart L of... - Criteria for Evaluating a State's Proposed NEPA-Like Process

Code of Federal Regulations, 2014 CFR

2014-07-01

... the SERP will adequately consider: (1) Designation of a study area comparable to the final system; (2... impacts; (4) Present and future conditions; (5) Land use and other social parameters including relevant... (residential, commercial, institutional, and industrial) within the project study area; and (8) Other...

40 CFR Appendix A to Subpart L - Criteria for Evaluating a State's Proposed NEPA-Like Process

Code of Federal Regulations, 2011 CFR

2011-07-01

... consider: (1) Designation of a study area comparable to the final system; (2) A range of feasible... conditions; (5) Land use and other social parameters including relevant recreation and open-space..., institutional, and industrial) within the project study area; and (8) Other anticipated public works projects...

Development of cryogenic PRD-49-1 filament-wound tanks

NASA Technical Reports Server (NTRS)

Hoggatt, J. T.

1971-01-01

A high modulus polymeric fiber was evaluated as a reinforcement for filament wound pressure vessels. Winding parameters and design data were established for the fiber with two different epoxy resin systems. Comparison was made between the performance factors of the polymeric fiber and those of S-glass and high modulus graphite vessels.

Population Invariance of Vertical Scaling Results

ERIC Educational Resources Information Center

Powers, Sonya; Turhan, Ahmet; Binici, Salih

2012-01-01

The population sensitivity of vertical scaling results was evaluated for a state reading assessment spanning grades 3-10 and a state mathematics test spanning grades 3-8. Subpopulations considered included males and females. The 3-parameter logistic model was used to calibrate math and reading items and a common item design was used to construct…

Evaluation of the AnnAGNPS model for predicting runoff and sediment yield in a small Mediterranean agricultural watershed in Navarre (Spain)

USDA-ARS?s Scientific Manuscript database

AnnAGNPS (Annualized Agricultural Non-Point Source Pollution Model) is a system of computer models developed to predict non-point source pollutant loadings within agricultural watersheds. It contains a daily time step distributed parameter continuous simulation surface runoff model designed to assis...

Thematic mapper design parameter investigation

NASA Technical Reports Server (NTRS)

Colby, C. P., Jr.; Wheeler, S. G.

1978-01-01

This study simulated the multispectral data sets to be expected from three different Thematic Mapper configurations, and the ground processing of these data sets by three different resampling techniques. The simulated data sets were then evaluated by processing them for multispectral classification, and the Thematic Mapper configuration, and resampling technique which provided the best classification accuracy were identified.

Improvements in safety testing of lithium cells

NASA Astrophysics Data System (ADS)

Stinebring, R. C.; Krehl, P.

1985-07-01

A systematic approach was developed for evaluating the basic safety parameters of high power lithium soluble cathode cells. This approach consists of performing a series of tests on each cell model during the design, prototype and production phases. Abusive testing is performed in a facility where maximum protection is given to test personnel.

Improvements in safety testing of lithium cells

NASA Technical Reports Server (NTRS)

Stinebring, R. C.; Krehl, P.

1985-01-01

A systematic approach was developed for evaluating the basic safety parameters of high power lithium soluble cathode cells. This approach consists of performing a series of tests on each cell model during the design, prototype and production phases. Abusive testing is performed in a facility where maximum protection is given to test personnel.

Design, Test, and Evaluation of a Transonic Axial Compressor Rotor with Splitter Blades

DTIC Science & Technology

2013-09-01

parameters .......................................................17 Figure 13. Third-order spline fit for blade camber line distribution...18 Figure 14. Third-order spline fit for blade thickness distribution .....................................19 Figure 15. Blade...leading edge: third-order spline fit for thickness distribution ...............20 Figure 16. Blade leading edge and trailing edge slope blending

In-situ evaluation of design parameters and procedures for cementitiously treated weak subgrades using cyclic plate load tests : project capsule.

DOT National Transportation Integrated Search

2013-06-01

Due to the soft nature of subsurface soils in southern Louisiana, roads often have to : be constructed on very weak subgrade soils with high in-situ moisture contents that : do not have the suffi cient strength/stiff ness to support the construction/...

Alternative Education for Disruptive Youth: Recommended Parameters and Best Practices for Effective Programs

ERIC Educational Resources Information Center

Pennsylvania Department of Education, 2005

2005-01-01

This document was prepared to serve as an aid in the planning, design, implementation, and ongoing evaluation of Alternative Education for Disruptive Youth Programs in Pennsylvania. School Codes and Public Laws are cited for guidance on mandatory issues. The suggestions and implementation strategies provided in this document are not requirements…

Evidence-based practice guidelines for instructing individuals with neurogenic memory impairments: what have we learned in the past 20 years?

PubMed

Ehlhardt, Laurie A; Sohlberg, McKay Moore; Kennedy, Mary; Coelho, Carl; Ylvisaker, Mark; Turkstra, Lyn; Yorkston, Kathryn

2008-06-01

This article examines the instructional research literature pertinent to teaching procedures or information to individuals with acquired memory impairments due to brain injury or related conditions. The purpose is to evaluate the available evidence in order to generate practice guidelines for clinicians working in the field of cognitive rehabilitation. A systematic review of the instructional literature from 1986 to 2006 revealed 51 studies meeting search criteria. Studies were analysed and coded within the following four key domains: Population Sample, Intervention, Study Design, and Treatment Outcomes. Coding included 17 characteristics of the population sample; seven intervention parameters; five study design features; and five treatment outcome parameters. Interventions that were evaluated included systematic instructional techniques such as method of vanishing cues and errorless learning. The majority of the studies reported positive outcomes in favour of systematic instruction. However, issues related to the design and execution of effective instruction lack clarity and require further study. The interaction between the target learning objective and the individual learner profile is not well understood. The evidence review concludes with clinical recommendations based on the instructional literature and a call to clinicians to incorporate these methods into their practice to maximise patient outcomes.

NR/EPDM elastomeric rubber blend miscibility evaluation by two-level fractional factorial design of experiment

NASA Astrophysics Data System (ADS)

Razak, Jeefferie Abd; Ahmad, Sahrim Haji; Ratnam, Chantara Thevy; Mahamood, Mazlin Aida; Yaakub, Juliana; Mohamad, Noraiham

2014-09-01

Fractional 25 two-level factorial design of experiment (DOE) was applied to systematically prepare the NR/EPDM blend using Haake internal mixer set-up. The process model of rubber blend preparation that correlates the relationships between the mixer process input parameters and the output response of blend compatibility was developed. Model analysis of variance (ANOVA) and model fitting through curve evaluation finalized the R2 of 99.60% with proposed parametric combination of A = 30/70 NR/EPDM blend ratio; B = 70°C mixing temperature; C = 70 rpm of rotor speed; D = 5 minutes of mixing period and E = 1.30 phr EPDM-g-MAH compatibilizer addition, with overall 0.966 desirability. Model validation with small deviation at +2.09% confirmed the repeatability of the mixing strategy with valid maximum tensile strength output representing the blend miscibility. Theoretical calculation of NR/EPDM blend compatibility is also included and compared. In short, this study provides a brief insight on the utilization of DOE for experimental simplification and parameter inter-correlation studies, especially when dealing with multiple variables during elastomeric rubber blend preparation.

ThermoData Engine (TDE): software implementation of the dynamic data evaluation concept. 5. Experiment planning and product design.

PubMed

Diky, Vladimir; Chirico, Robert D; Kazakov, Andrei F; Muzny, Chris D; Magee, Joseph W; Abdulagatov, Ilmutdin; Kang, Jeong Won; Kroenlein, Kenneth; Frenkel, Michael

2011-01-24

ThermoData Engine (TDE) is the first full-scale software implementation of the dynamic data evaluation concept, as reported recently in this journal. In the present paper, we describe development of an algorithmic approach to assist experiment planning through assessment of the existing body of knowledge, including availability of experimental thermophysical property data, variable ranges studied, associated uncertainties, state of prediction methods, and parameters for deployment of prediction methods and how these parameters can be obtained using targeted measurements, etc., and, indeed, how the intended measurement may address the underlying scientific or engineering problem under consideration. A second new feature described here is the application of the software capabilities for aid in the design of chemical products through identification of chemical systems possessing desired values of thermophysical properties within defined ranges of tolerance. The algorithms and their software implementation to achieve this are described. Finally, implementation of a new data validation and weighting system is described for vapor-liquid equilibrium (VLE) data, and directions for future enhancements are outlined.

Comparison of empirical strategies to maximize GENEHUNTER lod scores.

PubMed

Chen, C H; Finch, S J; Mendell, N R; Gordon, D

1999-01-01

We compare four strategies for finding the settings of genetic parameters that maximize the lod scores reported in GENEHUNTER 1.2. The four strategies are iterated complete factorial designs, iterated orthogonal Latin hypercubes, evolutionary operation, and numerical optimization. The genetic parameters that are set are the phenocopy rate, penetrance, and disease allele frequency; both recessive and dominant models are considered. We selected the optimization of a recessive model on the Collaborative Study on the Genetics of Alcoholism (COGA) data of chromosome 1 for complete analysis. Convergence to a setting producing a local maximum required the evaluation of over 100 settings (for a time budget of 800 minutes on a Pentium II 300 MHz PC). Two notable local maxima were detected, suggesting the need for a more extensive search before claiming that a global maximum had been found. The orthogonal Latin hypercube design was the best strategy for finding areas that produced high lod scores with small numbers of evaluations. Numerical optimization starting from a region producing high lod scores was the strategy that found the highest maximum observed.

Using Central Composite Experimental Design to Optimize the Degradation of Tylosin from Aqueous Solution by Photo-Fenton Reaction

PubMed Central

Sarrai, Abd Elaziz; Hanini, Salah; Merzouk, Nachida Kasbadji; Tassalit, Djilali; Szabó, Tibor; Hernádi, Klára; Nagy, László

2016-01-01

The feasibility of the application of the Photo-Fenton process in the treatment of aqueous solution contaminated by Tylosin antibiotic was evaluated. The Response Surface Methodology (RSM) based on Central Composite Design (CCD) was used to evaluate and optimize the effect of hydrogen peroxide, ferrous ion concentration and initial pH as independent variables on the total organic carbon (TOC) removal as the response function. The interaction effects and optimal parameters were obtained by using MODDE software. The significance of the independent variables and their interactions was tested by means of analysis of variance (ANOVA) with a 95% confidence level. Results show that the concentration of the ferrous ion and pH were the main parameters affecting TOC removal, while peroxide concentration had a slight effect on the reaction. The optimum operating conditions to achieve maximum TOC removal were determined. The model prediction for maximum TOC removal was compared to the experimental result at optimal operating conditions. A good agreement between the model prediction and experimental results confirms the soundness of the developed model. PMID:28773551

Cavity Heating Experiments Supporting Shuttle Columbia Accident Investigation

NASA Technical Reports Server (NTRS)

Everhart, Joel L.; Berger, Karen T.; Bey, Kim S.; Merski, N. Ronald; Wood, William A.

2011-01-01

The two-color thermographic phosphor method has been used to map the local heating augmentation of scaled idealized cavities at conditions simulating the windward surface of the Shuttle Orbiter Columbia during flight STS-107. Two experiments initiated in support of the Columbia Accident Investigation were conducted in the Langley 20-Inch Mach 6 Tunnel. Generally, the first test series evaluated open (length-to-depth less than 10) rectangular cavity geometries proposed as possible damage scenarios resulting from foam and ice impact during launch at several discrete locations on the vehicle windward surface, though some closed (length-to-depth greater than 13) geometries were briefly examined. The second test series was designed to parametrically evaluate heating augmentation in closed rectangular cavities. The tests were conducted under laminar cavity entry conditions over a range of local boundary layer edge-flow parameters typical of re-entry. Cavity design parameters were developed using laminar computational predictions, while the experimental boundary layer state conditions were inferred from the heating measurements. An analysis of the aeroheating caused by cavities allowed exclusion of non-breeching damage from the possible loss scenarios being considered during the investigation.

Optimization of ciprofloxacin complex loaded PLGA nanoparticles for pulmonary treatment of cystic fibrosis infections: Design of experiments approach.

PubMed

Günday Türeli, Nazende; Türeli, Akif Emre; Schneider, Marc

2016-12-30

Design of Experiments (DoE) is a powerful tool for systematic evaluation of process parameters' effect on nanoparticle (NP) quality with minimum number of experiments. DoE was employed for optimization of ciprofloxacin loaded PLGA NPs for pulmonary delivery against Pseudomonas aeruginosa infections in cystic fibrosis (CF) lungs. Since the biofilm produced by bacteria was shown to be a complicated 3D barrier with heterogeneous meshes ranging from 100nm to 500nm, nanoformulations small enough to travel through those channels were assigned as target quality. Nanoprecipitation was realized utilizing MicroJet Reactor (MJR) technology based on impinging jets principle. Effect of MJR parameters flow rate, temperature and gas pressure on particle size and PDI was investigated using Box-Behnken design. The relationship between process parameters and particle quality was demonstrated by constructed fit functions (R 2 =0.9934 p<0.0001 and R 2 =0.9983 p<0.0001, for particle size and PDI, respectively). Prepared nanoformulations varied between 145.2 and 979.8nm with PDI ranging from 0.050 to 1.00 and showed encapsulation efficiencies >65%. Response surface plots provided experimental data-based understanding of MJR parameters' effect, thus NP quality. Presented work enables ciprofloxacin loaded PLGA nanoparticle preparations with pre-defined quality to fulfill the requirements of local drug delivery under CF disease conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

A Gaussian Approximation Approach for Value of Information Analysis.

PubMed

Jalal, Hawre; Alarid-Escudero, Fernando

2018-02-01

Most decisions are associated with uncertainty. Value of information (VOI) analysis quantifies the opportunity loss associated with choosing a suboptimal intervention based on current imperfect information. VOI can inform the value of collecting additional information, resource allocation, research prioritization, and future research designs. However, in practice, VOI remains underused due to many conceptual and computational challenges associated with its application. Expected value of sample information (EVSI) is rooted in Bayesian statistical decision theory and measures the value of information from a finite sample. The past few years have witnessed a dramatic growth in computationally efficient methods to calculate EVSI, including metamodeling. However, little research has been done to simplify the experimental data collection step inherent to all EVSI computations, especially for correlated model parameters. This article proposes a general Gaussian approximation (GA) of the traditional Bayesian updating approach based on the original work by Raiffa and Schlaifer to compute EVSI. The proposed approach uses a single probabilistic sensitivity analysis (PSA) data set and involves 2 steps: 1) a linear metamodel step to compute the EVSI on the preposterior distributions and 2) a GA step to compute the preposterior distribution of the parameters of interest. The proposed approach is efficient and can be applied for a wide range of data collection designs involving multiple non-Gaussian parameters and unbalanced study designs. Our approach is particularly useful when the parameters of an economic evaluation are correlated or interact.

Semi-physical Simulation of the Airborne InSAR based on Rigorous Geometric Model and Real Navigation Data

NASA Astrophysics Data System (ADS)

Changyong, Dou; Huadong, Guo; Chunming, Han; yuquan, Liu; Xijuan, Yue; Yinghui, Zhao

2014-03-01

Raw signal simulation is a useful tool for the system design, mission planning, processing algorithm testing, and inversion algorithm design of Synthetic Aperture Radar (SAR). Due to the wide and high frequent variation of aircraft's trajectory and attitude, and the low accuracy of the Position and Orientation System (POS)'s recording data, it's difficult to quantitatively study the sensitivity of the key parameters, i.e., the baseline length and inclination, absolute phase and the orientation of the antennas etc., of the airborne Interferometric SAR (InSAR) system, resulting in challenges for its applications. Furthermore, the imprecise estimation of the installation offset between the Global Positioning System (GPS), Inertial Measurement Unit (IMU) and the InSAR antennas compounds the issue. An airborne interferometric SAR (InSAR) simulation based on the rigorous geometric model and real navigation data is proposed in this paper, providing a way for quantitatively studying the key parameters and for evaluating the effect from the parameters on the applications of airborne InSAR, as photogrammetric mapping, high-resolution Digital Elevation Model (DEM) generation, and surface deformation by Differential InSAR technology, etc. The simulation can also provide reference for the optimal design of the InSAR system and the improvement of InSAR data processing technologies such as motion compensation, imaging, image co-registration, and application parameter retrieval, etc.

Analysis of the influence of passenger vehicles front-end design on pedestrian lower extremity injuries by means of the LLMS model.

PubMed

Scattina, Alessandro; Mo, Fuhao; Masson, Catherine; Avalle, Massimiliano; Arnoux, Pierre Jean

2018-01-30

This work aims at investigating the influence of some front-end design parameters of a passenger vehicle on the behavior and damage occurring in the human lower limbs when impacted in an accident. The analysis is carried out by means of finite element analysis using a generic car model for the vehicle and the lower limbs model for safety (LLMS) for the purpose of pedestrian safety. Considering the pedestrian standardized impact procedure (as in the 2003/12/EC Directive), a parametric analysis, through a design of experiments plan, was performed. Various material properties, bumper thickness, position of the higher and lower bumper beams, and position of pedestrian, were made variable in order to identify how they influence the injury occurrence. The injury prediction was evaluated from the knee lateral flexion, ligament elongation, and state of stress in the bone structure. The results highlighted that the offset between the higher and lower bumper beams is the most influential parameter affecting the knee ligament response. The influence is smaller or absent considering the other responses and the other considered parameters. The stiffness characteristics of the bumper are, instead, more notable on the tibia. Even if an optimal value of the variables could not be identified trends were detected, with the potential of indicating strategies for improvement. The behavior of a vehicle front end in the impact against a pedestrian can be improved optimizing its design. The work indicates potential strategies for improvement. In this work, each parameter was changed independently one at a time; in future works, the interaction between the design parameters could be also investigated. Moreover, a similar parametric analysis can be carried out using a standard mechanical legform model in order to understand potential diversities or correlations between standard tools and human models.

Design Evaluation of Wind Turbine Spline Couplings Using an Analytical Model: Preprint

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

Guo, Y.; Keller, J.; Wallen, R.

2015-02-01

Articulated splines are commonly used in the planetary stage of wind turbine gearboxes for transmitting the driving torque and improving load sharing. Direct measurement of spline loads and performance is extremely challenging because of limited accessibility. This paper presents an analytical model for the analysis of articulated spline coupling designs. For a given torque and shaft misalignment, this analytical model quickly yields insights into relationships between the spline design parameters and resulting loads; bending, contact, and shear stresses; and safety factors considering various heat treatment methods. Comparisons of this analytical model against previously published computational approaches are also presented.

Aircraft IR/acoustic detection evaluation. Volume 2: Development of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft

NASA Technical Reports Server (NTRS)

Kraft, Robert E.

1992-01-01

The design and performance of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft is described and specified. The acoustic detection system performance criteria will subsequently be used to determine target detection ranges for the subject contract. Although the defined system has never been built and demonstrated in the field, the design parameters were chosen on the basis of achievable technology and overall system practicality. Areas where additional information is needed to substantiate the design are identified.

Design and analysis microstrip dipole using fractal Koch for 433 MHz applications

NASA Astrophysics Data System (ADS)

Zulfin, M.; Rambe, A. H.; Budi, B.

2018-02-01

This paper discussed the dipole microstrip antenna design using fractal Koch for working on frequency of 433 MHz. The fractal Koch was used to reduce the size of the microstrip antenna. The smaller the antenna size, the lighter the equipment. AWR simulator was employed to evaluate antenna parameters such as return loss, gain and radiation pattern. The antenna was designed on a FR4 substrate with relative permittivity of 4.4 and thickness 1.6 mm. The result shows that the fractal Koch reduce antenna size about 41.2% and decrease return loss about 30%.

Heat pipes for spacecraft temperature control: Their usefulness and limitations

NASA Technical Reports Server (NTRS)

Ollendorf, S.; Stipandic, E.

1972-01-01

Heat pipes are used in spacecraft to equalize the temperature of structures and maintain temperature control of electronic components. Information is provided for a designer on: (1) a typical mounting technique, (2) choices available in wick geometries and fluids, (3) tests involved in flight-qualifying the design, and (4) heat pipe limitations. An evaluation of several heat pipe designs showed that the behavior of heat pipes at room temperature does not necessarily correlate with the classic equations used to predict their performance. They are sensitive to such parameters as temperature, fluid inventory, orientation, and noncondensable gases.

Planar Microstrip Ring Resonators for Microwave-Based Gas Sensing: Design Aspects and Initial Transducers for Humidity and Ammonia Sensing.

PubMed

Bogner, Andreas; Steiner, Carsten; Walter, Stefanie; Kita, Jaroslaw; Hagen, Gunter; Moos, Ralf

2017-10-24

A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additional planar heater will be included on the reverse side of the resonator structure to allow for testing of gas-sensitive materials under sensor conditions.

Constellation Coverage Analysis

NASA Technical Reports Server (NTRS)

Lo, Martin W. (Compiler)

1997-01-01

The design of satellite constellations requires an understanding of the dynamic global coverage provided by the constellations. Even for a small constellation with a simple circular orbit propagator, the combinatorial nature of the analysis frequently renders the problem intractable. Particularly for the initial design phase where the orbital parameters are still fluid and undetermined, the coverage information is crucial to evaluate the performance of the constellation design. We have developed a fast and simple algorithm for determining the global constellation coverage dynamically using image processing techniques. This approach provides a fast, powerful and simple method for the analysis of global constellation coverage.

HF propagation factors affecting the design and operation of real time, channel evaluation, adaptive systems

NASA Astrophysics Data System (ADS)

Aarons, J.; Grossi, M. D.

1982-08-01

To develop and operate an adaptive system, propagation factors of the ionospheric medium must be given to the designer. The operation of the system must change as a function of multipath spread, Doppler spread, path losses, channel correlation functions, etc. In addition, NATO mid-latitude HF transmission and transauroral paths require varying system operation, which must fully utilize automatic path diversity across transauroral paths. Current research and literature are reviewed to estimate the extent of the available technical information. Additional investigations to allow designers to orient new systems on realistic models of these parameters are suggested.

Planar Microstrip Ring Resonators for Microwave-Based Gas Sensing: Design Aspects and Initial Transducers for Humidity and Ammonia Sensing

PubMed Central

Bogner, Andreas; Steiner, Carsten; Walter, Stefanie; Kita, Jaroslaw; Hagen, Gunter; Moos, Ralf

2017-01-01

A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additional planar heater will be included on the reverse side of the resonator structure to allow for testing of gas-sensitive materials under sensor conditions. PMID:29064438

Optimisation of lateral car dynamics taking into account parameter uncertainties

NASA Astrophysics Data System (ADS)

Busch, Jochen; Bestle, Dieter

2014-02-01

Simulation studies on an active all-wheel-steering car show that disturbance of vehicle parameters have high influence on lateral car dynamics. This motivates the need of robust design against such parameter uncertainties. A specific parametrisation is established combining deterministic, velocity-dependent steering control parameters with partly uncertain, velocity-independent vehicle parameters for simultaneous use in a numerical optimisation process. Model-based objectives are formulated and summarised in a multi-objective optimisation problem where especially the lateral steady-state behaviour is improved by an adaption strategy based on measurable uncertainties. The normally distributed uncertainties are generated by optimal Latin hypercube sampling and a response surface based strategy helps to cut down time consuming model evaluations which offers the possibility to use a genetic optimisation algorithm. Optimisation results are discussed in different criterion spaces and the achieved improvements confirm the validity of the proposed procedure.

A comparison of Stokes parameters for sky and a soybean canopy

NASA Technical Reports Server (NTRS)

Schutt, John B.; Holben, Brent N.; Mcmurtrey, James E., III

1991-01-01

An evaluation of the polarization signatures obtained from the four Stokes parameters is reported for the atmosphere and a soybean canopy. The polarimeter design and operation are set forth, and the Stokes parameters' relationships are discussed. The canopy polarization was different from the sky at azimuths of 90 and 270 degrees, demonstrating a response that reflecting the sky polarization signatures across a plane parallel to the polarization axis and passing through a phase angle of about 90 degrees would produce. Classical behavior in terms of electromagnetic theory was found in the fourth Stokes parameter of the canopy which was obtained in the principal plane. Only the third Stokes parameter is demonstrated to be unambiguously affected in a comparison of sky polarization signatures and aerosol optical densities. The similarity between the sky at azimuth 180 degrees and the soybean canopy data at the principal plane is interesting considering the disparity of the subjects.

Hierarchical Bayesian Model Averaging for Chance Constrained Remediation Designs

NASA Astrophysics Data System (ADS)

Chitsazan, N.; Tsai, F. T.

2012-12-01

Groundwater remediation designs are heavily relying on simulation models which are subjected to various sources of uncertainty in their predictions. To develop a robust remediation design, it is crucial to understand the effect of uncertainty sources. In this research, we introduce a hierarchical Bayesian model averaging (HBMA) framework to segregate and prioritize sources of uncertainty in a multi-layer frame, where each layer targets a source of uncertainty. The HBMA framework provides an insight to uncertainty priorities and propagation. In addition, HBMA allows evaluating model weights in different hierarchy levels and assessing the relative importance of models in each level. To account for uncertainty, we employ a chance constrained (CC) programming for stochastic remediation design. Chance constrained programming was implemented traditionally to account for parameter uncertainty. Recently, many studies suggested that model structure uncertainty is not negligible compared to parameter uncertainty. Using chance constrained programming along with HBMA can provide a rigorous tool for groundwater remediation designs under uncertainty. In this research, the HBMA-CC was applied to a remediation design in a synthetic aquifer. The design was to develop a scavenger well approach to mitigate saltwater intrusion toward production wells. HBMA was employed to assess uncertainties from model structure, parameter estimation and kriging interpolation. An improved harmony search optimization method was used to find the optimal location of the scavenger well. We evaluated prediction variances of chloride concentration at the production wells through the HBMA framework. The results showed that choosing the single best model may lead to a significant error in evaluating prediction variances for two reasons. First, considering the single best model, variances that stem from uncertainty in the model structure will be ignored. Second, considering the best model with non-dominant model weight may underestimate or overestimate prediction variances by ignoring other plausible propositions. Chance constraints allow developing a remediation design with a desirable reliability. However, considering the single best model, the calculated reliability will be different from the desirable reliability. We calculated the reliability of the design for the models at different levels of HBMA. The results showed that by moving toward the top layers of HBMA, the calculated reliability converges to the chosen reliability. We employed the chance constrained optimization along with the HBMA framework to find the optimal location and pumpage for the scavenger well. The results showed that using models at different levels in the HBMA framework, the optimal location of the scavenger well remained the same, but the optimal extraction rate was altered. Thus, we concluded that the optimal pumping rate was sensitive to the prediction variance. Also, the prediction variance was changed by using different extraction rate. Using very high extraction rate will cause prediction variances of chloride concentration at the production wells to approach zero regardless of which HBMA models used.

Comparison of Different Mo/Au TES Designs for Radiation Detectors

NASA Astrophysics Data System (ADS)

Pobes, Carlos; Fàbrega, Lourdes; Camón, Agustín; Strichovanec, Pavel; Moral-Vico, Javier; Casañ-Pastor, Nieves; Jáudenes, Rosa M.; Sesé, Javier

2018-05-01

We report on the fabrication and characterization of Mo/Au-based transition-edge sensors (TES), intended to be used in X-ray detectors. We have performed complete dark characterization using I-V curves, complex impedance and noise measurements at different bath temperatures and biases. Devices with two designs, different sizes and different membranes have been characterized, some of them with a central bismuth absorber. This has allowed extraction of the relevant parameters of the TES, analyses of their standard behavior and evaluation of their prospects.

Nuclear Data Uncertainty Propagation to Reactivity Coefficients of a Sodium Fast Reactor

NASA Astrophysics Data System (ADS)

Herrero, J. J.; Ochoa, R.; Martínez, J. S.; Díez, C. J.; García-Herranz, N.; Cabellos, O.

2014-04-01

The assessment of the uncertainty levels on the design and safety parameters for the innovative European Sodium Fast Reactor (ESFR) is mandatory. Some of these relevant safety quantities are the Doppler and void reactivity coefficients, whose uncertainties are quantified. Besides, the nuclear reaction data where an improvement will certainly benefit the design accuracy are identified. This work has been performed with the SCALE 6.1 codes suite and its multigroups cross sections library based on ENDF/B-VII.0 evaluation.

Effect of design selection on response surface performance

NASA Technical Reports Server (NTRS)

Carpenter, William C.

1993-01-01

Artificial neural nets and polynomial approximations were used to develop response surfaces for several test problems. Based on the number of functional evaluations required to build the approximations and the number of undetermined parameters associated with the approximations, the performance of the two types of approximations was found to be comparable. A rule of thumb is developed for determining the number of nodes to be used on a hidden layer of an artificial neural net and the number of designs needed to train an approximation is discussed.

Evaluation of an Al-Ce alloy for laser additive manufacturing

DOE PAGES

Plotkowski, A.; Rios, O.; Sridharan, N.; ...

2016-12-27

Our present research in metal additive manufacturing (AM) focuses on designing processing parameters around existing alloys designed for traditional manufacturing. However, to maximize the benefits of AM, alloys should be designed to specifically take advantage of the unique thermal conditions of these processes. Furthermore, our study focuses on the development of a design methodology for alloys in AM, using a newly developed Al-Ce alloy as an initial case study. To evaluate the candidacy of this system for fusion based additive manufacturing, single-line laser melts were made on cast Al-12Ce plates using three different beam velocities (100, 200, and 300 mm/min).more » The microstructure was evaluated in the as-melted and heat treated conditions (24 hrs at 300°C). An extremely fine microstructure was observed within the weld pools, evolving from eutectic at the outer solid-liquid boundaries to a primary Al FCC dendritic/cellular structure nearer the melt-pool centerline. We rationalized the observed microstructures through the construction of a microstructure selection map for the Al-Ce binary system, which will be used to enable future alloy design. Interestingly, the heat treated samples exhibited no microstructural coarsening.« less

Evaluation of camouflage effectiveness using hyperspectral images

NASA Astrophysics Data System (ADS)

Zavvartorbati, Ahmad; Dehghani, Hamid; Rashidi, Ali Jabar

2017-10-01

Recent advances in camouflage engineering have made it more difficult to detect targets. Assessing the effectiveness of camouflage against different target detection methods leads to identifying the strengths and weaknesses of camouflage designs. One of the target detection methods is to analyze the content of the scene using remote sensing hyperspectral images. In the process of evaluating camouflage designs, there must be comprehensive and efficient evaluation criteria. Three parameters were considered as the main factors affecting the target detection and based on these factors, camouflage effectiveness assessment criteria were proposed. To combine the criteria in the form of a single equation, the equation used in target visual search models was employed and for determining the criteria, a model was presented based on the structure of the computational visual attention systems. Also, in software implementations on the HyMap hyperspectral image, a variety of camouflage levels were created for the real targets in the image. Assessing the camouflage levels using the proposed criteria, comparing and analyzing the results can show that the provided criteria and model are effective for the evaluation of camouflage designs using hyperspectral images.

The combined effect of wet granulation process parameters and dried granule moisture content on tablet quality attributes.

PubMed

Gabbott, Ian P; Al Husban, Farhan; Reynolds, Gavin K

2016-09-01

A pharmaceutical compound was used to study the effect of batch wet granulation process parameters in combination with the residual moisture content remaining after drying on granule and tablet quality attributes. The effect of three batch wet granulation process parameters was evaluated using a multivariate experimental design, with a novel constrained design space. Batches were characterised for moisture content, granule density, crushing strength, porosity, disintegration time and dissolution. Mechanisms of the effect of the process parameters on the granule and tablet quality attributes are proposed. Water quantity added during granulation showed a significant effect on granule density and tablet dissolution rate. Mixing time showed a significant effect on tablet crushing strength, and mixing speed showed a significant effect on the distribution of tablet crushing strengths obtained. The residual moisture content remaining after granule drying showed a significant effect on tablet crushing strength. The effect of moisture on tablet tensile strength has been reported before, but not in combination with granulation parameters and granule properties, and the impact on tablet dissolution was not assessed. Correlations between the energy input during granulation, the density of granules produced, and the quality attributes of the final tablets were also identified. Understanding the impact of the granulation and drying process parameters on granule and tablet properties provides a basis for process optimisation and scaling. Copyright © 2016 Elsevier B.V. All rights reserved.

A sensitivity analysis of process design parameters, commodity prices and robustness on the economics of odour abatement technologies.

PubMed

Estrada, José M; Kraakman, N J R Bart; Lebrero, Raquel; Muñoz, Raúl

2012-01-01

The sensitivity of the economics of the five most commonly applied odour abatement technologies (biofiltration, biotrickling filtration, activated carbon adsorption, chemical scrubbing and a hybrid technology consisting of a biotrickling filter coupled with carbon adsorption) towards design parameters and commodity prices was evaluated. Besides, the influence of the geographical location on the Net Present Value calculated for a 20 years lifespan (NPV20) of each technology and its robustness towards typical process fluctuations and operational upsets were also assessed. This comparative analysis showed that biological techniques present lower operating costs (up to 6 times) and lower sensitivity than their physical/chemical counterparts, with the packing material being the key parameter affecting their operating costs (40-50% of the total operating costs). The use of recycled or partially treated water (e.g. secondary effluent in wastewater treatment plants) offers an opportunity to significantly reduce costs in biological techniques. Physical/chemical technologies present a high sensitivity towards H2S concentration, which is an important drawback due to the fluctuating nature of malodorous emissions. The geographical analysis evidenced high NPV20 variations around the world for all the technologies evaluated, but despite the differences in wage and price levels, biofiltration and biotrickling filtration are always the most cost-efficient alternatives (NPV20). When, in an economical evaluation, the robustness is as relevant as the overall costs (NPV20), the hybrid technology would move up next to BTF as the most preferred technologies. Copyright © 2012 Elsevier Inc. All rights reserved.

HuMOVE: a low-invasive wearable monitoring platform in sexual medicine.

PubMed

Ciuti, Gastone; Nardi, Matteo; Valdastri, Pietro; Menciassi, Arianna; Basile Fasolo, Ciro; Dario, Paolo

2014-10-01

To investigate an accelerometer-based wearable system, named Human Movement (HuMOVE) platform, designed to enable quantitative and continuous measurement of sexual performance with minimal invasiveness and inconvenience for users. Design, implementation, and development of HuMOVE, a wearable platform equipped with an accelerometer sensor for monitoring inertial parameters for sexual performance assessment and diagnosis, were performed. The system enables quantitative measurement of movement parameters during sexual intercourse, meeting the requirements of wearability, data storage, sampling rate, and interfacing methods, which are fundamental for human sexual intercourse performance analysis. HuMOVE was validated through characterization using a controlled experimental test bench and evaluated in a human model during simulated sexual intercourse conditions. HuMOVE demonstrated to be a robust and quantitative monitoring platform and a reliable candidate for sexual performance evaluation and diagnosis. Characterization analysis on the controlled experimental test bench demonstrated an accurate correlation between the HuMOVE system and data from a reference displacement sensor. Experimental tests in the human model during simulated intercourse conditions confirmed the accuracy of the sexual performance evaluation platform and the effectiveness of the selected and derived parameters. The obtained outcomes also established the project expectations in terms of usability and comfort, evidenced by the questionnaires that highlighted the low invasiveness and acceptance of the device. To the best of our knowledge, HuMOVE platform is the first device for human sexual performance analysis compatible with sexual intercourse; the system has the potential to be a helpful tool for physicians to accurately classify sexual disorders, such as premature or delayed ejaculation. Copyright © 2014 Elsevier Inc. All rights reserved.

Controlling Microbial Byproducts using Model-Based Substrate Monitoring and Control Strategies

NASA Technical Reports Server (NTRS)

Smernoff, David T.; Blackwell, Charles; Mancinelli, Rocco L.; DeVincenzi, Donald (Technical Monitor)

2000-01-01

We have developed a computer-controlled bioreactor system to study various aspects of microbially-mediated nitrogen cycling. The system has been used to investigate methods for controlling microbial denitrification (the dissimilatory reduction of nitrate to N2O and N2) in hydroponic plant growth chambers. Such chambers are key elements of advanced life support systems being designed for use on long duration space missions, but nitrogen use efficiency in them is reduced by denitrification. Control software architecture was designed which permits the heterogeneous control of system hardware using traditional feedback control, and quantitative and qualitative models of various system features. Model-based feed forward control entails prediction of future systems in states and automated regulation of system parameters to achieve desired and avoid undesirable system states. A bacterial growth rate model based on the classic Monod model of saturation kinetics was used to evaluate the response of several individual denitrifying species to varying environmental conditions. The system and models are now being applied to mixed microbial communities harvested from the root zone of a hydroponic growth chamber. The use of a modified Monod organism interaction model was evaluated as a means of achieving more accurate description of the dynamic behavior of the communities. A minimum variance parameter estimation routine was also' used to calibrate the constant parameters in the model by iterative evaluation of substrate (nitrate) uptake and growth kinetics. This representation of processes and interactions aids in the formulation of control laws. The feed forward control strategy being developed will increase system autonomy, reduce crew intervention and limit the accumulation of undesirable waste products (NOx).

Predicting the effectiveness of road safety campaigns through alternative research designs.

PubMed

Adamos, Giannis; Nathanail, Eftihia

2016-12-01

A large number of road safety communication campaigns have been designed and implemented in the recent years; however their explicit impact on driving behavior and road accident rates has been estimated in a rather low proportion. Based on the findings of the evaluation of three road safety communication campaigns addressing the issues of drinking and driving, seat belt usage, and driving fatigue, this paper applies different types of research designs (i.e., experimental, quasi-experimental, and non-experimental designs), when estimating the effectiveness of road safety campaigns, implements a cross-design assessment, and conducts a cross-campaign evaluation. An integrated evaluation plan was developed, taking into account the structure of evaluation questions, the definition of measurable variables, the separation of the target audience into intervention (exposed to the campaign) and control (not exposed to the campaign) groups, the selection of alternative research designs, and the appropriate data collection methods and techniques. Evaluating the implementation of different research designs in estimating the effectiveness of road safety campaigns, results showed that the separate pre-post samples design demonstrated better predictability than other designs, especially in data obtained from the intervention group after the realization of the campaign. The more constructs that were added to the independent variables, the higher the values of the predictability were. The construct that most affects behavior is intention, whereas the rest of the constructs have a lower impact on behavior. This is particularly significant in the Health Belief Model (HBM). On the other hand, behavioral beliefs, normative beliefs, and descriptive norms, are significant parameters for predicting intention according to the Theory of Planned Behavior (TPB). The theoretical and applied implications of alternative research designs and their applicability in the evaluation of road safety campaigns are provided by this study. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

Cost Effectiveness Analysis of Quasi-In-Motion Wireless Power Transfer for Plug-In Hybrid Electric Transit Buses from Fleet Perspective

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

Wang, Lijuan; Gonder, Jeff; Brooker, Aaron

This study evaluated the costs and benefits associated with the use of stationary-wireless-power-transfer-enabled plug-in hybrid electric buses and determined the cost effectiveness relative to conventional buses and hybrid electric buses. A factorial design was performed over a number of different battery sizes, charging power levels, and f bus stop charging stations. The net present costs were calculated for each vehicle design and provided the basis for design evaluation. In all cases, given the assumed economic conditions, the conventional bus achieved the lowest net present cost while the optimal plug-in hybrid electric bus scenario beat out the hybrid electric comparison scenario.more » The parameter sensitivity was also investigated under favorable and unfavorable market penetration assumptions.« less