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Sample records for evolutionary design principle

  1. Evolutionary principles and their practical application

    PubMed Central

    Hendry, Andrew P; Kinnison, Michael T; Heino, Mikko; Day, Troy; Smith, Thomas B; Fitt, Gary; Bergstrom, Carl T; Oakeshott, John; Jørgensen, Peter S; Zalucki, Myron P; Gilchrist, George; Southerton, Simon; Sih, Andrew; Strauss, Sharon; Denison, Robert F; Carroll, Scott P

    2011-01-01

    Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design of harvesting regimes that minimize unwanted life-history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently in these different fields, even though the underlying fundamental concepts are the same. We explore these fundamental concepts under four main themes: variation, selection, connectivity, and eco-evolutionary dynamics. Within each theme, we present several key evolutionary principles and illustrate their use in addressing applied problems. We hope that the resulting primer of evolutionary concepts and their practical utility helps to advance a unified multidisciplinary field of applied evolutionary biology. PMID:25567966

  2. The evolutionary diversity of insect retinal mosaics: common design principles and emerging molecular logic.

    PubMed

    Wernet, Mathias F; Perry, Michael W; Desplan, Claude

    2015-06-01

    Independent evolution has resulted in a vast diversity of eyes. Despite the lack of a common Bauplan or ancestral structure, similar developmental strategies are used. For instance, different classes of photoreceptor cells (PRs) are distributed stochastically and/or localized in different regions of the retina. Here, we focus on recent progress made towards understanding the molecular principles behind patterning retinal mosaics of insects, one of the most diverse groups of animals adapted to life on land, in the air, under water, or on the water surface. Morphological, physiological, and behavioral studies from many species provide detailed descriptions of the vast variation in retinal design and function. By integrating this knowledge with recent progress in the characterization of insect Rhodopsins as well as insight from the model organism Drosophila melanogaster, we seek to identify the molecular logic behind the adaptation of retinal mosaics to the habitat and way of life of an animal. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. The evolutionary diversity of insect retinal mosaics: Common design principles and emerging molecular logic

    PubMed Central

    Wernet, Mathias F.; Perry, Michael W.; Desplan, Claude

    2015-01-01

    Independent evolution has resulted in a vast diversity of eyes. Despite the lack of a common Bauplan or ancestral structure, similar developmental strategies are used. For instance, different classes of photoreceptor cells (PRs) are distributed stochastically and/or localized in different regions of the retina. Here we focus on recent progress made towards understanding the molecular principles behind patterning retinal mosaics of insects, one of the most diverse groups of animals adapted to life on land, in the air, under water, or on the water surface. Morphological, physiological, and behavioral studies from many species provide detailed descriptions of the vast variation in retinal design and function. By integrating this knowledge with recent progress in the characterization of insect Rhodopsins as well as insight from the model organism Drosophila melanogaster, we seek to identify the molecular logic behind the adaptation of retinal mosaics to an animal’s habitat and way of life. PMID:26025917

  4. Principled Design and Runtime Analysis of Abstract Convex Evolutionary Search.

    PubMed

    Moraglio, Alberto; Sudholt, Dirk

    2017-01-01

    Geometric crossover is a formal class of crossovers that includes many well-known recombination operators across representations. In previous work, it was shown that all evolutionary algorithms with geometric crossover (but no mutation) do the same form of convex search regardless of the underlying representation, the specific selection mechanism, offspring distribution, search space, and problem at hand. Furthermore, it was suggested that the generalised convex search could perform well on generalised forms of concave and approximately concave fitness landscapes regardless of the underlying space and representation. In this article, we deepen this line of enquiry and study the runtime of generalised convex search on concave fitness landscapes. This is a first step toward linking a geometric theory of representations and runtime analysis in the attempt to (1) set the basis for a more general, unified approach for the runtime analysis of evolutionary algorithms across representations, and (2) identify the essential matching features of evolutionary search behaviour and landscape topography that cause polynomial performance. We present a general runtime result that can be systematically instantiated to specific search spaces and representations and present its specifications to three search spaces. As a corollary, we obtain that the convex search algorithm optimises LeadingOnes in [Formula: see text] fitness evaluations, which is faster than all unbiased unary black box algorithms.

  5. Evolutionary Design in Art

    NASA Astrophysics Data System (ADS)

    McCormack, Jon

    Evolution is one of the most interesting and creative processes we currently understand, so it should come as no surprise that artists and designers are embracing the use of evolution in problems of artistic creativity. The material in this section illustrates the diversity of approaches being used by artists and designers in relation to evolution at the boundary of art and science. While conceptualising human creativity as an evolutionary process in itself may be controversial, what is clear is that evolutionary processes can be used to complement, even enhance human creativity, as the chapters in this section aptly demonstrate.

  6. Evolutionary Multiobjective Optimization: Principles, Procedures, and Practices

    NASA Astrophysics Data System (ADS)

    Deb, Kalyanmoy

    2010-10-01

    Multi-objective optimization problems deal with multiple conflicting objectives. In principle, they give rise to a set of trade-off Pareto-optimal solutions. Over the past one-and-half decade, evolutionary multi-objective optimization (EMO) has established itself as a mature field of research and application with an extensive literature, commercial softwares, numerous freely downloadable codes, a dedicated biannual conference running successfully five times so far since 2001, special sessions and workshops held at all major evolutionary computing conferences, and full-time researchers from universities and industries from all around the globe. This is because evolutionary algorithms (EAs) work with a population of solutions and in solving multi-objective optimization problems, EAs can be modified to find and capture multiple solutions in a single simulation run. In this article, we make a brief outline of EMO principles, discuss one specific EMO algorithm, and present some current research issues of EMO.

  7. Evolutionary dynamics from a variational principle.

    PubMed

    Klimek, Peter; Thurner, Stefan; Hanel, Rudolf

    2010-07-01

    We demonstrate with a thought experiment that fitness-based population dynamical approaches to evolution are not able to make quantitative, falsifiable predictions about the long-term behavior of some evolutionary systems. A key characteristic of evolutionary systems is the ongoing endogenous production of new species. These novel entities change the conditions for already existing species. Even Darwin's Demon, a hypothetical entity with exact knowledge of the abundance of all species and their fitness functions at a given time, could not prestate the impact of these novelties on established populations. We argue that fitness is always a posteriori knowledge--it measures but does not explain why a species has reproductive success or not. To overcome these conceptual limitations, a variational principle is proposed in a spin-model-like setup of evolutionary systems. We derive a functional which is minimized under the most general evolutionary formulation of a dynamical system, i.e., evolutionary trajectories causally emerge as a minimization of a functional. This functional allows the derivation of analytic solutions of the asymptotic diversity for stochastic evolutionary systems within a mean-field approximation. We test these approximations by numerical simulations of the corresponding model and find good agreement in the position of phase transitions in diversity curves. The model is further able to reproduce stylized facts of timeseries from several man-made and natural evolutionary systems. Light will be thrown on how species and their fitness landscapes dynamically coevolve.

  8. Evolutionary Design in Biology

    NASA Astrophysics Data System (ADS)

    Wiese, Kay C.

    Much progress has been achieved in recent years in molecular biology and genetics. The sheer volume of data in the form of biological sequences has been enormous and efficient methods for dealing with these huge amounts of data are needed. In addition, the data alone does not provide information on the workings of biological systems; hence much research effort has focused on designing mathematical and computational models to address problems from molecular biology. Often, the terms bioinformatics and computational biology are used to refer to the research fields concerning themselves with designing solutions to molecular problems in biology. However, there is a slight distinction between bioinformatics and computational biology: the former is concerned with managing the enormous amounts of biological data and extracting information from it, while the latter is more concerned with the design and development of new algorithms to address problems such as protein or RNA folding. However, the boundary is blurry, and there is no consistent usage of the terms. We will use the term bioinformatics to encompass both fields. To cover all areas of research in bioinformatics is beyond the scope of this section and we refer the interested reader to [2] for a general introduction. A large part of what bioinformatics is concerned about is evolution and function of biological systems on a molecular level. Evolutionary computation and evolutionary design are concerned with developing computational systems that "mimic" certain aspects of natural evolution (mutation, crossover, selection, fitness). Much of the inner workings of natural evolutionary systems have been copied, sometimes in modified format into evolutionary computation systems. Artificial neural networks mimic the functioning of simple brain cell clusters. Fuzzy systems are concerned with the "fuzzyness" in decision making, similar to a human expert. These three computational paradigms fall into the category of

  9. Algorithmic Mechanism Design of Evolutionary Computation

    PubMed Central

    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. PMID:26257777

  10. 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.

  11. Instructional Software Design Principles.

    ERIC Educational Resources Information Center

    Hazen, Margret

    1985-01-01

    Discusses learner/computer interaction, learner control, sequencing of instructional events, and graphic screen design as effective principles for the design of instructional software, including tutorials. (MBR)

  12. Instructional Software Design Principles.

    ERIC Educational Resources Information Center

    Hazen, Margret

    1985-01-01

    Discusses learner/computer interaction, learner control, sequencing of instructional events, and graphic screen design as effective principles for the design of instructional software, including tutorials. (MBR)

  13. Quantitative evolutionary design

    PubMed Central

    Diamond, Jared

    2002-01-01

    The field of quantitative evolutionary design uses evolutionary reasoning (in terms of natural selection and ultimate causation) to understand the magnitudes of biological reserve capacities, i.e. excesses of capacities over natural loads. Ratios of capacities to loads, defined as safety factors, fall in the range 1.2-10 for most engineered and biological components, even though engineered safety factors are specified intentionally by humans while biological safety factors arise through natural selection. Familiar examples of engineered safety factors include those of buildings, bridges and elevators (lifts), while biological examples include factors of bones and other structural elements, of enzymes and transporters, and of organ metabolic performances. Safety factors serve to minimize the overlap zone (resulting in performance failure) between the low tail of capacity distributions and the high tail of load distributions. Safety factors increase with coefficients of variation of load and capacity, with capacity deterioration with time, and with cost of failure, and decrease with costs of initial construction, maintenance, operation, and opportunity. Adaptive regulation of many biological systems involves capacity increases with increasing load; several quantitative examples suggest sublinear increases, such that safety factors decrease towards 1.0. Unsolved questions include safety factors of series systems, parallel or branched pathways, elements with multiple functions, enzyme reaction chains, and equilibrium enzymes. The modest sizes of safety factors imply the existence of costs that penalize excess capacities. Those costs are likely to involve wasted energy or space for large or expensive components, but opportunity costs of wasted space at the molecular level for minor components. PMID:12122135

  14. Achieving sustainable plant disease management through evolutionary principles.

    PubMed

    Zhan, Jiasui; Thrall, Peter H; Burdon, Jeremy J

    2014-09-01

    Plants and their pathogens are engaged in continuous evolutionary battles and sustainable disease management requires novel systems to create environments conducive for short-term and long-term disease control. In this opinion article, we argue that knowledge of the fundamental factors that drive host-pathogen coevolution in wild systems can provide new insights into disease development in agriculture. Such evolutionary principles can be used to guide the formulation of sustainable disease management strategies which can minimize disease epidemics while simultaneously reducing pressure on pathogens to evolve increased infectivity and aggressiveness. To ensure agricultural sustainability, disease management programs that reflect the dynamism of pathogen population structure are essential and evolutionary biologists should play an increasing role in their design. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Designing and engineering evolutionary robust genetic circuits

    PubMed Central

    2010-01-01

    Background One problem with engineered genetic circuits in synthetic microbes is their stability over evolutionary time in the absence of selective pressure. Since design of a selective environment for maintaining function of a circuit will be unique to every circuit, general design principles are needed for engineering evolutionary robust circuits that permit the long-term study or applied use of synthetic circuits. Results We first measured the stability of two BioBrick-assembled genetic circuits propagated in Escherichia coli over multiple generations and the mutations that caused their loss-of-function. The first circuit, T9002, loses function in less than 20 generations and the mutation that repeatedly causes its loss-of-function is a deletion between two homologous transcriptional terminators. To measure the effect between transcriptional terminator homology levels and evolutionary stability, we re-engineered six versions of T9002 with a different transcriptional terminator at the end of the circuit. When there is no homology between terminators, the evolutionary half-life of this circuit is significantly improved over 2-fold and is independent of the expression level. Removing homology between terminators and decreasing expression level 4-fold increases the evolutionary half-life over 17-fold. The second circuit, I7101, loses function in less than 50 generations due to a deletion between repeated operator sequences in the promoter. This circuit was re-engineered with different promoters from a promoter library and using a kanamycin resistance gene (kanR) within the circuit to put a selective pressure on the promoter. The evolutionary stability dynamics and loss-of-function mutations in all these circuits are described. We also found that on average, evolutionary half-life exponentially decreases with increasing expression levels. Conclusions A wide variety of loss-of-function mutations are observed in BioBrick-assembled genetic circuits including point

  16. Incorporating evolutionary principles into environmental management and policy

    PubMed Central

    Lankau, Richard; Jørgensen, Peter Søgaard; Harris, David J; Sih, Andrew

    2011-01-01

    As policymakers and managers work to mitigate the effects of rapid anthropogenic environmental changes, they need to consider organisms’ responses. In light of recent evidence that evolution can be quite rapid, this now includes evolutionary responses. Evolutionary principles have a long history in conservation biology, and the necessary next step for the field is to consider ways in which conservation policy makers and managers can proactively manipulate evolutionary processes to achieve their goals. In this review, we aim to illustrate the potential conservation benefits of an increased understanding of evolutionary history and prescriptive manipulation of three basic evolutionary factors: selection, variation, and gene flow. For each, we review and propose ways that policy makers and managers can use evolutionary thinking to preserve threatened species, combat pest species, or reduce undesirable evolutionary changes. Such evolution-based management has potential to be a highly efficient and consistent way to create greater ecological resilience to widespread, rapid, and multifaceted environmental change. PMID:25567975

  17. Guiding deployment of resistance in cereals using evolutionary principles

    PubMed Central

    Burdon, Jeremy J; Barrett, Luke G; Rebetzke, Greg; Thrall, Peter H

    2014-01-01

    Genetically controlled resistance provides plant breeders with an efficient means of controlling plant disease, but this approach has been constrained by practical difficulties associated with combining many resistance genes together and strong evolutionary responses from pathogen populations leading to subsequent resistance breakdown. However, continuing advances in molecular marker technologies are revolutionizing the ability to rapidly and reliably manipulate resistances of all types – major gene, adult plant and quantitative resistance loci singly or multiply into individual host lines. Here, we argue that these advances provide major opportunities to deliberately design deployment strategies in cereals that can take advantage of the evolutionary pressures faced by target pathogens. Different combinations of genes deployed either within single host individuals or between different individuals within or among crops, can be used to reduce the size of pathogen populations and generate patterns of disruptive selection. This will simultaneously limit immediate epidemic development and reduce the probability of subsequent evolutionary change in the pathogen for broader infectivity or increased aggressiveness. The same general principles are relevant to the control of noncereal diseases, but the most efficacious controls will vary reflecting the range of genetic options available and their fit with specific ecology and life-history combinations. PMID:25067946

  18. Can Evolutionary Principles Explain Patterns of Family Violence?

    ERIC Educational Resources Information Center

    Archer, John

    2013-01-01

    The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated…

  19. Can Evolutionary Principles Explain Patterns of Family Violence?

    ERIC Educational Resources Information Center

    Archer, John

    2013-01-01

    The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated…

  20. Subwavelength lattice optics by evolutionary design.

    PubMed

    Huntington, Mark D; Lauhon, Lincoln J; Odom, Teri W

    2014-12-10

    This paper describes a new class of structured optical materials--lattice opto-materials--that can manipulate the flow of visible light into a wide range of three-dimensional profiles using evolutionary design principles. Lattice opto-materials are based on the discretization of a surface into a two-dimensional (2D) subwavelength lattice whose individual lattice sites can be controlled to achieve a programmed optical response. To access a desired optical property, we designed a lattice evolutionary algorithm that includes and optimizes contributions from every element in the lattice. Lattice opto-materials can exhibit simple properties, such as on- and off-axis focusing, and can also concentrate light into multiple, discrete spots. We expanded the unit cell shapes of the lattice to achieve distinct, polarization-dependent optical responses from the same 2D patterned substrate. Finally, these lattice opto-materials can also be combined into architectures that resemble a new type of compound flat lens.

  1. Principles of smile design

    PubMed Central

    Bhuvaneswaran, Mohan

    2010-01-01

    An organized and systematic approach is required to evaluate, diagnose and resolve esthetic problems predictably. It is of prime importance that the final result is not dependent only on the looks alone. Our ultimate goal as clinicians is to achieve pleasing composition in the smile by creating an arrangement of various esthetic elements. This article reviews the various principles that govern the art of smile designing. The literature search was done using PubMed search and Medline. This article will provide a basic knowledge to the reader to bring out a functional stable smile. PMID:21217950

  2. Application of evolutionary principles to cancer therapy

    PubMed Central

    Enriquez-Navas, Pedro M.; Wojtkowiak, Jonathan W.; Gatenby, Robert A.

    2015-01-01

    The dynamic cancer ecosystem, with its rich temporal and spatial diversity in environmental conditions and heritable cell phenotypes, is remarkably robust to therapeutic perturbations. Even when response to therapy is clinically complete, adaptive tumor strategies almost inevitably emerge and the tumor returns. Although evolution of resistance remains the proximate cause of death in most cancer patients, a recent analysis (1) found that evolutionary terms were included in less than 1% of manuscripts on the cancer treatment outcomes and this has not changed in 30 years. Here we review treatment methods that attempt to understand and exploit intratumoral evolution to prolong response to therapy. In general, we find that treating metastatic (i.e. non-curable) cancers using the traditional strategy aimed at killing the maximum number of tumor cells is evolutionarily unsound because, by eliminating all treatment-sensitive cells, it enables rapid proliferation of resistant populations – a well-known evolutionary phenomenon termed “competitive release (2, 3).” Alternative strategies such as adaptive therapy (4, 5), “ersatzdroges (6),” and double bind treatments (7) shift focus from eliminating tumor cells to evolution-based methods that suppress growth of resistant populations to maintain long term control. PMID:26527288

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

    PubMed

    Menges, Achim

    2012-03-01

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

  4. Can evolutionary principles explain patterns of family violence?

    PubMed

    Archer, John

    2013-03-01

    The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated by (a) parents to unrelated children, (b) parents to genetic offspring, and (c) offspring to parents and between (d) siblings and (e) sexual partners. Precise figures for risks have been calculated where possible. The major conclusions are that most of the evidence is consistent with evolutionary predictions derived from kin selection and reproductive value: There were (a) higher rates of violence to stepchildren, (b) a decline in violence with the age of offspring, and (c) an increase in violence with parental age, while (d) violence between siblings was generally at a low level and concerned resource disputes. The issue of distinguishing evolutionary from alternative explanations is addressed throughout and is problematic for predictions derived from reproductive value. The main evolutionary explanation for male partner violence, mate guarding as a result of paternity uncertainty, cannot explain Western studies where sex differences in control and violence between partners were absent, although other aspects of male partner violence are consistent with it, and it may explain sex differences in traditional cultures. Recurrent problems in evaluating the evidence were to control for possible confounds and thus to distinguish evolutionary from alternative explanations. Suggestions are outlined to address this and other issues arising from the review. © 2013 American Psychological Association

  5. EPR: an Advanced Evolutionary Design

    SciTech Connect

    Czech, Juergen; Bouteille, Francois; Hudson, Greg

    2004-07-01

    This paper presents the main features of the EPR, an evolutionary design product that builds on French N4 plants (Chooz and Civaux) and Konvoi, the most recent reactor series built in Germany. This Franco-German project was driven by a common French and German desire to cooperate in several areas. In January 2001, Framatome SA and Siemens AG merged their nuclear activities to form Framatome ANP with three regional entities in France, Germany and the USA. The recent decision of Teollisuuden Voima Oy (TVO) to select the EPR for construction in Olkiluoto of the fifth Nuclear Power Plant in Finland gave a new impetus to the project. Framatome ANP is committed to put the FOAK EPR in commercial operation on May 1, 2009. This challenging time schedule will set a new reference for 'Generation III +' LWR's. (authors)

  6. Subwavelength Lattice Optics by Evolutionary Design

    PubMed Central

    2015-01-01

    This paper describes a new class of structured optical materials—lattice opto-materials—that can manipulate the flow of visible light into a wide range of three-dimensional profiles using evolutionary design principles. Lattice opto-materials are based on the discretization of a surface into a two-dimensional (2D) subwavelength lattice whose individual lattice sites can be controlled to achieve a programmed optical response. To access a desired optical property, we designed a lattice evolutionary algorithm that includes and optimizes contributions from every element in the lattice. Lattice opto-materials can exhibit simple properties, such as on- and off-axis focusing, and can also concentrate light into multiple, discrete spots. We expanded the unit cell shapes of the lattice to achieve distinct, polarization-dependent optical responses from the same 2D patterned substrate. Finally, these lattice opto-materials can also be combined into architectures that resemble a new type of compound flat lens. PMID:25380062

  7. The Evolutionary Design of Proteins

    NASA Astrophysics Data System (ADS)

    Poelwijk, Frank J.; Raman, Arjun S.; Leibler, Stanislas; Ranganathan, Rama

    2011-03-01

    Proteins fold spontaneously into precise, well-packed 3D structures, and execute complex functions such as specificity in molecular recognition, and efficient catalysis. Despite this, many studies show that proteins are robust to random mutagenesis. Additionally, proteins are evolvable. What principles underlying the design of natural proteins explain these properties? Recent work examining correlated evolution of amino acid positions shows that many positions in proteins are nearly statistically independent while 10-20% are organized into groups of co-evolving positions - termed ``protein sectors'' - that underlie conserved, independently varying biological activities. These findings suggest that the basic design of natural proteins is fundamentally tied to the nature of fluctuations in the selection pressures during evolution. We propose to test this hypothesis using a system for high-speed laboratory evolution and determine how variation in selection pressures influences the architecture of amino acid interactions within a protein.

  8. Evolutionary objections to "alien design" models.

    NASA Astrophysics Data System (ADS)

    Coffey, E. J.

    A previous paper demonstrated that the principal supporters of SETI have ignored the biological and evolutionary consequences of a creature's body form. In fact, the supporting evidence they provide actually contradicts their view. The approach they employ is that of the engineer: the process of "designing" a hypothetical creature to a specification irrespective of biological or evolutionary considerations. The principal types of "alien designs" which have been employed shall be discussed, and the evolutionary objections to them given.

  9. Evolutionary Design of Controlled Structures

    NASA Technical Reports Server (NTRS)

    Masters, Brett P.; Crawley, Edward F.

    1997-01-01

    Basic physical concepts of structural delay and transmissibility are provided for simple rod and beam structures. Investigations show the sensitivity of these concepts to differing controlled-structures variables, and to rational system modeling effects. An evolutionary controls/structures design method is developed. The basis of the method is an accurate model formulation for dynamic compensator optimization and Genetic Algorithm based updating of sensor/actuator placement and structural attributes. One and three dimensional examples from the literature are used to validate the method. Frequency domain interpretation of these controlled structure systems provide physical insight as to how the objective is optimized and consequently what is important in the objective. Several disturbance rejection type controls-structures systems are optimized for a stellar interferometer spacecraft application. The interferometric designs include closed loop tracking optics. Designs are generated for differing structural aspect ratios, differing disturbance attributes, and differing sensor selections. Physical limitations in achieving performance are given in terms of average system transfer function gains and system phase loss. A spacecraft-like optical interferometry system is investigated experimentally over several different optimized controlled structures configurations. Configurations represent common and not-so-common approaches to mitigating pathlength errors induced by disturbances of two different spectra. Results show that an optimized controlled structure for low frequency broadband disturbances achieves modest performance gains over a mass equivalent regular structure, while an optimized structure for high frequency narrow band disturbances is four times better in terms of root-mean-square pathlength. These results are predictable given the nature of the physical system and the optimization design variables. Fundamental limits on controlled performance are discussed

  10. Properties of Artifact Representations for Evolutionary Design

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2004-01-01

    To achieve evolutionary design systems that scale to the levels achieved by man-made artifacts we can look to their characteristics of modularity, hierarchy and regularity to guide us. For this we focus on design representations, since they strongly determine the ability of evolutionary design systems to evolve artifacts with these characteristics. We identify three properties of design representations - combination, control-flow and abstraction - and discuss how they relate to hierarchy, modularity and regularity.

  11. Properties of Artifact Representations for Evolutionary Design

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2004-01-01

    To achieve evolutionary design systems that scale to the levels achieved by man-made artifacts we can look to their characteristics of modularity, hierarchy and regularity to guide us. For this we focus on design representations, since they strongly determine the ability of evolutionary design systems to evolve artifacts with these characteristics. We identify three properties of design representations - combination, control-flow and abstraction - and discuss how they relate to hierarchy, modularity and regularity.

  12. An Evolutionary Approach to Designing Neural Networks

    DTIC Science & Technology

    1991-10-01

    Feature-Map Networks .. .. .. .. ... ... .... ... ... ... .... 42 4.5 Evolution of Learning: A Population Genetics Approach. .. .. .. .. ... .... .. 44...principles of biological evolution and population genetics provide the basis for such behavior. The processes of variation and selection, operating at...better understanding of the relationship among neural network theory, evolutionary and population genetics , and some aspects of dynamical systems

  13. Energy principles in architectural design

    SciTech Connect

    Dean, E.

    1981-01-01

    A foundation of basic information pertaining to design and energy use in buildings is presented with emphasis on principles and concepts rather than applications of particular solution. Energy impacts of landforms and topography, vegetation, wind and ventilation, and sun on planning and designing the site are discused. General design considerations involving passive heating, cooling, and lighting systems are detailed. For the design of active building systems, heating, cooling, lighting, and HVAC systems are described. (MCW)

  14. Automated Hardware Design via Evolutionary Search

    NASA Technical Reports Server (NTRS)

    Lohn, Jason D.; Colombano, Silvano P.

    2000-01-01

    The goal of this research is to investigate the application of evolutionary search to the process of automated engineering design. Evolutionary search techniques involve the simulation of Darwinian mechanisms by computer algorithms. In recent years, such techniques have attracted much attention because they are able to tackle a wide variety of difficult problems and frequently produce acceptable solutions. The results obtained are usually functional, often surprising, and typically "messy" because the algorithms are told to concentrate on the overriding objective and not elegance or simplicity. advantages. First, faster design cycles translate into time and, hence, cost savings. Second, automated design techniques can be made to scale well and hence better deal with increasing amounts of design complexity. Third, design quality can increase because design properties can be specified a priori. For example, size and weight specifications of a device, smaller and lighter than the best known design, might be optimized by the automated design technique. The domain of electronic circuit design is an advantageous platform in which to study automated design techniques because it is a rich design space that is well understood, permitting human-created designs to be compared to machine- generated designs. developed for circuit design was to automatically produce high-level integrated electronic circuit designs whose properties permit physical implementation in silicon. This process entailed designing an effective evolutionary algorithm and solving a difficult multiobjective optimization problem. FY 99 saw many accomplishments in this effort.

  15. Aesthetic Principles for Instructional Design

    ERIC Educational Resources Information Center

    Parrish, Patrick E.

    2009-01-01

    This article offers principles that contribute to developing the aesthetics of instructional design. Rather than describing merely the surface qualities of things and events, the concept of aesthetics as applied here pertains to heightened, integral experience. Aesthetic experiences are those that are immersive, infused with meaning, and felt as…

  16. Four Principles for Designing Instructions.

    DTIC Science & Technology

    1983-04-01

    D-AI28 923 FOUR PRINCIPLES FOR DVSIONINO INSTRUCTIONS IU COLORADO / UNIV AT BOULDER INS OF COGNITIE SCIENCE P BAGGET APR 83 TR-121ONR N0OC 4 R -C...TEST CAR PMIVM.BUEA i SANARS-96- Four Principles for Designing Instructions ntTechnical Report No. 121-ONR This remearch was sormored by the Persnne...DOCUMENTATION PAGE sar n u S 1O NUR GOVT ACCESSION i. N itii[Nti CATALMOG UM1190121-0NRl 1 %01 jd1 4. TITLE (and lde) S. TYPE OF REPORT & PERIOD COVERED Four

  17. Evolutionary Multi-objective Optimization for landscape system design

    NASA Astrophysics Data System (ADS)

    Roberts, S. A.; Hall, G. B.; Calamai, P. H.

    2011-09-01

    Increasing recognition of the extent and speed of habitat fragmentation and loss, particularly in the urban fringe, is driving the need to analyze qualitatively and quantitatively regional landscape structures in land-use planning and environmental policy implementation. This paper introduces an Evolutionary Multi-objective Optimization (EMO) methodology to estimate the Pareto optimal set of landscape designs generated from a series of underlying ecological principles. The results of applying these principles via EMO to a study site are presented and a hierarchical clustering methodology is introduced to assist in evaluating the population of solutions generated.

  18. Automated Antenna Design with Evolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.; Globus, Al; Linden, Derek S.; Lohn, Jason D.

    2006-01-01

    Current methods of designing and optimizing antennas by hand are time and labor intensive, and limit complexity. Evolutionary design techniques can overcome these limitations by searching the design space and automatically finding effective solutions. In recent years, evolutionary algorithms have shown great promise in finding practical solutions in large, poorly understood design spaces. In particular, spacecraft antenna design has proven tractable to evolutionary design techniques. Researchers have been investigating evolutionary antenna design and optimization since the early 1990s, and the field has grown in recent years as computer speed has increased and electromagnetic simulators have improved. Two requirements-compliant antennas, one for ST5 and another for TDRS-C, have been automatically designed by evolutionary algorithms. The ST5 antenna is slated to fly this year, and a TDRS-C phased array element has been fabricated and tested. Such automated evolutionary design is enabled by medium-to-high quality simulators and fast modern computers to evaluate computer-generated designs. Evolutionary algorithms automate cut-and-try engineering, substituting automated search though millions of potential designs for intelligent search by engineers through a much smaller number of designs. For evolutionary design, the engineer chooses the evolutionary technique, parameters and the basic form of the antenna, e.g., single wire for ST5 and crossed-element Yagi for TDRS-C. Evolutionary algorithms then search for optimal configurations in the space defined by the engineer. NASA's Space Technology 5 (ST5) mission will launch three small spacecraft to test innovative concepts and technologies. Advanced evolutionary algorithms were used to automatically design antennas for ST5. The combination of wide beamwidth for a circularly-polarized wave and wide impedance bandwidth made for a challenging antenna design problem. From past experience in designing wire antennas, we chose to

  19. An Evolutionary Optimization System for Spacecraft Design

    NASA Technical Reports Server (NTRS)

    Fukunaga, A.; Stechert, A.

    1997-01-01

    Spacecraft design optimization is a domian that can benefit from the application of optimization algorithms such as genetic algorithms. In this paper, we describe DEVO, an evolutionary optimization system that addresses these issues and provides a tool that can be applied to a number of real-world spacecraft design applications. We describe two current applications of DEVO: physical design if a Mars Microprobe Soil Penetrator, and system configuration optimization for a Neptune Orbiter.

  20. Plasmonic nanoantenna design and fabrication based on evolutionary optimization.

    PubMed

    Feichtner, Thorsten; Selig, Oleg; Hecht, Bert

    2017-05-15

    Nanoantennas can tailor light-matter interaction for optical communication, sensing, and spectroscopy. Their design is inspired by radio-frequency rules which partly break down at optical frequencies. Here we find unexpected nanoantenna designs exhibiting strong light localization and enhancement by using a general and scalable evolutionary algorithm based on FDTD simulations that also accounts for geometrical fabrication constraints. The resulting nanoantennas are "printed" directly by focused-ion beam milling and their fitness ranking is validated experimentally by two-photon photoluminescence. We find the best antennas' operation principle deviating from that of classical radio wave-inspired designs. Our work sets the stage for a widespread application of evolutionary optimization in nano photonics.

  1. Developmental and Evolutionary Lexicon Acquisition in Cognitive Agents/Robots with Grounding Principle: A Short Review

    PubMed Central

    Rasheed, Nadia; Amin, Shamsudin H. M.

    2016-01-01

    Grounded language acquisition is an important issue, particularly to facilitate human-robot interactions in an intelligent and effective way. The evolutionary and developmental language acquisition are two innovative and important methodologies for the grounding of language in cognitive agents or robots, the aim of which is to address current limitations in robot design. This paper concentrates on these two main modelling methods with the grounding principle for the acquisition of linguistic ability in cognitive agents or robots. This review not only presents a survey of the methodologies and relevant computational cognitive agents or robotic models, but also highlights the advantages and progress of these approaches for the language grounding issue. PMID:27069470

  2. Evolutionary design of corrugated horn antennas

    NASA Technical Reports Server (NTRS)

    Hoorfar, F.; Manshadi, V.; Jamnejad, A.

    2002-01-01

    An evolutionary progranirnitzg (EP) algorithm is used to optimize pattern of a corrugated circularhorn subject to various constraints on return loss and antenna beamwidth and pattern circularity and low crosspolarization. The EP algorithm uses a Gaussian mutation operator. Examples on design synthesis of a 45 section corrugated horn, with a total of 90 optimization parameters, are presented. The results show excellent and efficient optimization of the desired horn parameters.

  3. Evolutionary design of corrugated horn antennas

    NASA Technical Reports Server (NTRS)

    Hoorfar, F.; Manshadi, V.; Jamnejad, A.

    2002-01-01

    An evolutionary progranirnitzg (EP) algorithm is used to optimize pattern of a corrugated circularhorn subject to various constraints on return loss and antenna beamwidth and pattern circularity and low crosspolarization. The EP algorithm uses a Gaussian mutation operator. Examples on design synthesis of a 45 section corrugated horn, with a total of 90 optimization parameters, are presented. The results show excellent and efficient optimization of the desired horn parameters.

  4. How evolutionary principles improve the understanding of human health and disease

    PubMed Central

    Gluckman, Peter D; Low, Felicia M; Buklijas, Tatjana; Hanson, Mark A; Beedle, Alan S

    2011-01-01

    An appreciation of the fundamental principles of evolutionary biology provides new insights into major diseases and enables an integrated understanding of human biology and medicine. However, there is a lack of awareness of their importance amongst physicians, medical researchers, and educators, all of whom tend to focus on the mechanistic (proximate) basis for disease, excluding consideration of evolutionary (ultimate) reasons. The key principles of evolutionary medicine are that selection acts on fitness, not health or longevity; that our evolutionary history does not cause disease, but rather impacts on our risk of disease in particular environments; and that we are now living in novel environments compared to those in which we evolved. We consider these evolutionary principles in conjunction with population genetics and describe several pathways by which evolutionary processes can affect disease risk. These perspectives provide a more cohesive framework for gaining insights into the determinants of health and disease. Coupled with complementary insights offered by advances in genomic, epigenetic, and developmental biology research, evolutionary perspectives offer an important addition to understanding disease. Further, there are a number of aspects of evolutionary medicine that can add considerably to studies in other domains of contemporary evolutionary studies. PMID:25567971

  5. Visual Design Principles: An Empirical Study of Design Lore

    ERIC Educational Resources Information Center

    Kimball, Miles A.

    2013-01-01

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

  6. Visual Design Principles: An Empirical Study of Design Lore

    ERIC Educational Resources Information Center

    Kimball, Miles A.

    2013-01-01

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

  7. Principles of Intelligence: On Evolutionary Logic of the Brain.

    PubMed

    Tsien, Joe Z

    2015-01-01

    Humans and animals may encounter numerous events, objects, scenes, foods and countless social interactions in a lifetime. This means that the brain is constructed by evolution to deal with uncertainties and various possibilities. What is the architectural abstraction of intelligence that enables the brain to discover various possible patterns and knowledge about complex, evolving worlds? Here, I discuss the Theory of Connectivity-a "power-of-two" based, operational principle that can serve as a unified wiring and computational logic for organizing and constructing cell assemblies into the microcircuit-level building block, termed as functional connectivity motif (FCM). Defined by the power-of-two based equation, N = 2 (i) -1, each FCM consists of the principal projection neuron cliques (N), ranging from those specific cliques receiving specific information inputs (i) to those general and sub-general cliques receiving various combinatorial convergent inputs. As the evolutionarily conserved logic, its validation requires experimental demonstrations of the following three major properties: (1) Anatomical prevalence-FCMs are prevalent across neural circuits, regardless of gross anatomical shapes; (2) Species conservancy-FCMs are conserved across different animal species; and (3) Cognitive universality-FCMs serve as a universal computational logic at the cell assembly level for processing a variety of cognitive experiences and flexible behaviors. More importantly, this Theory of Connectivity further predicts that the specific-to-general combinatorial connectivity pattern within FCMs should be preconfigured by evolution, and emerge innately from development as the brain's computational primitives. This proposed design-principle can also explain the general purpose of the layered cortex and serves as its core computational algorithm.

  8. Principles of Intelligence: On Evolutionary Logic of the Brain

    PubMed Central

    Tsien, Joe Z.

    2016-01-01

    Humans and animals may encounter numerous events, objects, scenes, foods and countless social interactions in a lifetime. This means that the brain is constructed by evolution to deal with uncertainties and various possibilities. What is the architectural abstraction of intelligence that enables the brain to discover various possible patterns and knowledge about complex, evolving worlds? Here, I discuss the Theory of Connectivity–a “power-of-two” based, operational principle that can serve as a unified wiring and computational logic for organizing and constructing cell assemblies into the microcircuit-level building block, termed as functional connectivity motif (FCM). Defined by the power-of-two based equation, N = 2i−1, each FCM consists of the principal projection neuron cliques (N), ranging from those specific cliques receiving specific information inputs (i) to those general and sub-general cliques receiving various combinatorial convergent inputs. As the evolutionarily conserved logic, its validation requires experimental demonstrations of the following three major properties: (1) Anatomical prevalence—FCMs are prevalent across neural circuits, regardless of gross anatomical shapes; (2) Species conservancy—FCMs are conserved across different animal species; and (3) Cognitive universality—FCMs serve as a universal computational logic at the cell assembly level for processing a variety of cognitive experiences and flexible behaviors. More importantly, this Theory of Connectivity further predicts that the specific-to-general combinatorial connectivity pattern within FCMs should be preconfigured by evolution, and emerge innately from development as the brain’s computational primitives. This proposed design-principle can also explain the general purpose of the layered cortex and serves as its core computational algorithm. PMID:26869892

  9. Evolutionary Technique for Designing Optimized Arrays

    NASA Astrophysics Data System (ADS)

    Villazón, J.; Ibañez, A.

    2011-06-01

    Many ultrasonic inspection applications in the industry could benefit from the use of phased array distributions specifically designed for them. Some common design requirements are: to adapt the shape of the array to that of the part to be inspected, to use large apertures for increasing lateral resolution, to find a layout of elements that avoids artifacts produced by lateral and/or grating lobes, to maintain the total number of independent elements (and the number of control channels) as low as possible to reduce complexity and cost of the inspection system. Recent advances in transducer technology have made possible to design and build arrays whit non-regular layout of elements. In this paper we propose to use Evolutionary Algorithms to find layouts of ultrasonic arrays (whether 1D or 2D array) that approach a set of specified beampattern characteristics using a low number of elements.

  10. Genetic variation and human disease: Principles and evolutionary approaches

    SciTech Connect

    Weiss, K.M.

    1993-12-31

    The context of the book here reviewed is the evolution of human phenotypes, with an emphasis on those complex characteristics that produce the prevailing disorders of an adult population. This is achieved with a background of evolution and population genetics, with human diseases placed in the context of mutation rates, selection, genetic drift and evolutionary history.

  11. Evolutionary Process: An Organizing Principle for General Education.

    ERIC Educational Resources Information Center

    Mears, John A.

    1986-01-01

    Proposes a science-oriented general education core, stressing the importance of serious scientific study in understanding contemporary human existence. Describes the four courses comprising the core, which use the evolutionary process as the unifying concept for the study of physics, astronomy, geology, chemistry, biology, anthropology,…

  12. Materials design principles of ancient fish armour.

    PubMed

    Bruet, Benjamin J F; Song, Juha; Boyce, Mary C; Ortiz, Christine

    2008-09-01

    Knowledge of the structure-property-function relationships of dermal scales of armoured fish could enable pathways to improved bioinspired human body armour, and may provide clues to the evolutionary origins of mineralized tissues. Here, we present a multiscale experimental and computational approach that reveals the materials design principles present within individual ganoid scales from the 'living fossil' Polypterus senegalus. This fish belongs to the ancient family Polypteridae, which first appeared 96 million years ago during the Cretaceous period and still retains many of their characteristics. The mechanistic origins of penetration resistance (approximating a biting attack) were investigated and found to include the juxtaposition of multiple distinct reinforcing composite layers that each undergo their own unique deformation mechanisms, a unique spatial functional form of mechanical properties with regions of differing levels of gradation within and between material layers, and layers with an undetectable gradation, load-dependent effective material properties, circumferential surface cracking, orthogonal microcracking in laminated sublayers and geometrically corrugated junctions between layers.

  13. Building synthetic systems to learn nature's design principles.

    PubMed

    Davidson, Eric A; Windram, Oliver P F; Bayer, Travis S

    2012-01-01

    Evolution undoubtedly shapes the architecture of biological systems, yet it is unclear which features of regulatory, metabolic, and signalling circuits have adaptive significance and how the architecture of these circuits constrains or promotes evolutionary processes, such as adaptation to new environments. Experimentally rewiring circuits using genetic engineering and constructing novel circuits in living cells allows direct testing and validation of hypotheses in evolutionary systems biology. Building synthetic genetic systems enables researchers to explore regions of the genotype-phenotype and fitness landscapes that may be inaccessible to more traditional analysis. Here, we review the strategies that allow synthetic systems to be constructed and how evolutionary design principles have advanced these technologies. We also describe how building small genetic regulatory systems can provide insight on the trade-offs that constrain adaptation and can shape the structure of biological networks. In the future, the possibility of building biology de novo at the genome scale means that increasingly sophisticated models of the evolutionary dynamics of networks can be proposed and validated, and will allow us to recreate ancestral systems in the lab. This interplay between evolutionary systems theory and engineering design may illuminate the fundamental limits of performance, robustness, and evolvability of living systems.

  14. Universal Instructional Design Principles for Moodle

    ERIC Educational Resources Information Center

    Elias, Tanya

    2010-01-01

    This paper identifies a set of universal instructional design (UID) principles appropriate to distance education (DE) and specifically tailored to the needs of instructional designers and instructors teaching online. These principles are then used to assess the accessibility level of a sample online course and the availability of options in its…

  15. First principles prediction of amorphous phases using evolutionary algorithms.

    PubMed

    Nahas, Suhas; Gaur, Anshu; Bhowmick, Somnath

    2016-07-07

    We discuss the efficacy of evolutionary method for the purpose of structural analysis of amorphous solids. At present, ab initio molecular dynamics (MD) based melt-quench technique is used and this deterministic approach has proven to be successful to study amorphous materials. We show that a stochastic approach motivated by Darwinian evolution can also be used to simulate amorphous structures. Applying this method, in conjunction with density functional theory based electronic, ionic and cell relaxation, we re-investigate two well known amorphous semiconductors, namely silicon and indium gallium zinc oxide. We find that characteristic structural parameters like average bond length and bond angle are within ∼2% of those reported by ab initio MD calculations and experimental studies.

  16. First principles prediction of amorphous phases using evolutionary algorithms

    NASA Astrophysics Data System (ADS)

    Nahas, Suhas; Gaur, Anshu; Bhowmick, Somnath

    2016-07-01

    We discuss the efficacy of evolutionary method for the purpose of structural analysis of amorphous solids. At present, ab initio molecular dynamics (MD) based melt-quench technique is used and this deterministic approach has proven to be successful to study amorphous materials. We show that a stochastic approach motivated by Darwinian evolution can also be used to simulate amorphous structures. Applying this method, in conjunction with density functional theory based electronic, ionic and cell relaxation, we re-investigate two well known amorphous semiconductors, namely silicon and indium gallium zinc oxide. We find that characteristic structural parameters like average bond length and bond angle are within ˜2% of those reported by ab initio MD calculations and experimental studies.

  17. The Molecular Apgar Score: A Key to Unlocking Evolutionary Principles.

    PubMed

    Torday, John S; Nielsen, Heber C

    2017-01-01

    such, these molecular elements can be examined using a Molecular Apgar evaluation of keystone evolutionary events that predict successful evolutionary adaptation of physiologic functions necessary for neonatal transition and survival.

  18. Evolutionary approach for determining first-principles hamiltonians.

    PubMed

    Hart, Gus L W; Blum, Volker; Walorski, Michael J; Zunger, Alex

    2005-05-01

    Modern condensed-matter theory from first principles is highly successful when applied to materials of given structure-type or restricted unit-cell size. But this approach is limited where large cells or searches over millions of structure types become necessary. To treat these with first-principles accuracy, one 'coarse-grains' the many-particle Schrodinger equation into 'model hamiltonians' whose variables are configurational order parameters (atomic positions, spin and so on), connected by a few 'interaction parameters' obtained from a microscopic theory. But to construct a truly quantitative model hamiltonian, one must know just which types of interaction parameters to use, from possibly 10(6)-10(8) alternative selections. Here we show how genetic algorithms, mimicking biological evolution ('survival of the fittest'), can be used to distil reliable model hamiltonian parameters from a database of first-principles calculations. We demonstrate this for a classic dilemma in solid-state physics, structural inorganic chemistry and metallurgy: how to predict the stable crystal structure of a compound given only its composition. The selection of leading parameters based on a genetic algorithm is general and easily applied to construct any other type of complex model hamiltonian from direct quantum-mechanical results.

  19. The Molecular Apgar Score: A Key to Unlocking Evolutionary Principles

    PubMed Central

    Torday, John S.; Nielsen, Heber C.

    2017-01-01

    Apgar Score. As such, these molecular elements can be examined using a Molecular Apgar evaluation of keystone evolutionary events that predict successful evolutionary adaptation of physiologic functions necessary for neonatal transition and survival. PMID:28373969

  20. Designing and Implementing Multicultural Initiatives: Guiding Principles

    ERIC Educational Resources Information Center

    Watt, Sherry K.

    2013-01-01

    This chapter provides guiding principles for designing and implementing successful multicultural initiatives. A rationale for why these elements transcend both higher education and student affairs settings is presented. In addition to providing guiding principles, this chapter includes advice for socially and politically conscious-minded…

  1. Evolutionary optimization methods for accelerator design

    NASA Astrophysics Data System (ADS)

    Poklonskiy, Alexey A.

    Many problems from the fields of accelerator physics and beam theory can be formulated as optimization problems and, as such, solved using optimization methods. Despite growing efficiency of the optimization methods, the adoption of modern optimization techniques in these fields is rather limited. Evolutionary Algorithms (EAs) form a relatively new and actively developed optimization methods family. They possess many attractive features such as: ease of the implementation, modest requirements on the objective function, a good tolerance to noise, robustness, and the ability to perform a global search efficiently. In this work we study the application of EAs to problems from accelerator physics and beam theory. We review the most commonly used methods of unconstrained optimization and describe the GATool, evolutionary algorithm and the software package, used in this work, in detail. Then we use a set of test problems to assess its performance in terms of computational resources, quality of the obtained result, and the tradeoff between them. We justify the choice of GATool as a heuristic method to generate cutoff values for the COSY-GO rigorous global optimization package for the COSY Infinity scientific computing package. We design the model of their mutual interaction and demonstrate that the quality of the result obtained by GATool increases as the information about the search domain is refined, which supports the usefulness of this model. We Giscuss GATool's performance on the problems suffering from static and dynamic noise and study useful strategies of GATool parameter tuning for these and other difficult problems. We review the challenges of constrained optimization with EAs and methods commonly used to overcome them. We describe REPA, a new constrained optimization method based on repairing, in exquisite detail, including the properties of its two repairing techniques: REFIND and REPROPT. We assess REPROPT's performance on the standard constrained

  2. Evolutionary Multiobjective Design Targeting a Field Programmable Transistor Array

    NASA Technical Reports Server (NTRS)

    Aguirre, Arturo Hernandez; Zebulum, Ricardo S.; Coello, Carlos Coello

    2004-01-01

    This paper introduces the ISPAES algorithm for circuit design targeting a Field Programmable Transistor Array (FPTA). The use of evolutionary algorithms is common in circuit design problems, where a single fitness function drives the evolution process. Frequently, the design problem is subject to several goals or operating constraints, thus, designing a suitable fitness function catching all requirements becomes an issue. Such a problem is amenable for multi-objective optimization, however, evolutionary algorithms lack an inherent mechanism for constraint handling. This paper introduces ISPAES, an evolutionary optimization algorithm enhanced with a constraint handling technique. Several design problems targeting a FPTA show the potential of our approach.

  3. Evolutionary Multiobjective Design Targeting a Field Programmable Transistor Array

    NASA Technical Reports Server (NTRS)

    Aguirre, Arturo Hernandez; Zebulum, Ricardo S.; Coello, Carlos Coello

    2004-01-01

    This paper introduces the ISPAES algorithm for circuit design targeting a Field Programmable Transistor Array (FPTA). The use of evolutionary algorithms is common in circuit design problems, where a single fitness function drives the evolution process. Frequently, the design problem is subject to several goals or operating constraints, thus, designing a suitable fitness function catching all requirements becomes an issue. Such a problem is amenable for multi-objective optimization, however, evolutionary algorithms lack an inherent mechanism for constraint handling. This paper introduces ISPAES, an evolutionary optimization algorithm enhanced with a constraint handling technique. Several design problems targeting a FPTA show the potential of our approach.

  4. Compound prism design principles, I

    PubMed Central

    Hagen, Nathan; Tkaczyk, Tomasz S.

    2011-01-01

    Prisms have been needlessly neglected as components used in modern optical design. In optical throughput, stray light, flexibility, and in their ability to be used in direct-view geometry, they excel over gratings. Here we show that even their well-known weak dispersion relative to gratings has been overrated by designing doublet and double Amici direct-vision compound prisms that have 14° and 23° of dispersion across the visible spectrum, equivalent to 800 and 1300 lines/mm gratings. By taking advantage of the multiple degrees of freedom available in a compound prism design, we also show prisms whose angular dispersion shows improved linearity in wavelength. In order to achieve these designs, we exploit the well-behaved nature of prism design space to write customized algorithms that optimize directly in the nonlinear design space. Using these algorithms, we showcase a number of prism designs that illustrate a performance and flexibility that goes beyond what has often been considered possible with prisms. PMID:22423145

  5. Photovoltaics: Basic Design Principles and Components

    SciTech Connect

    1997-03-01

    This publication will introduce you to the basic design principles and components of PV systems. It will also help you discuss these systems knowledgeably with an equipment supplier or system installer.

  6. The application of evolutionary medicine principles for sustainable malaria control: a scoping study.

    PubMed

    Ocampo, Denise; Booth, Mark

    2016-07-22

    Current interventions against malaria have significantly reduced the number of people infected and the number of deaths. Concerns about emerging resistance of both mosquitoes and parasites to intervention have been raised, and questions remain about how best to generate wider knowledge of the underlying evolutionary processes. The pedagogical and research principles of evolutionary medicine may provide an answer to this problem. Eight programme managers and five academic researchers were interviewed by telephone or videoconference to elicit their first-hand views and experiences of malaria control given that evolution is a constant threat to sustainable control. Interviewees were asked about their views on the relationship between practit groups and academics and for their thoughts on whether or not evolutionary medicine may provide a solution to reported tensions. There was broad agreement that evolution of both parasites and vectors presents an obstacle to sustainable control. It was also widely agreed that through more efficient monitoring, evolution could be widely monitored. Interviewees also expressed the view that even well planned interventions may fail if the evolutionary biology of the disease is not considered, potentially making current tools redundant. This scoping study suggests that it is important to make research, including evolutionary principles, available and easily applicable for programme managers and key decision-makers, including donors and politicians. The main conclusion is that sharing knowledge through the educational and research processes embedded within evolutionary medicine has potential to relieve tensions and facilitate sustainable control of malaria and other parasitic infections.

  7. Directionality theory: a computational study of an entropic principle in evolutionary processes.

    PubMed

    Kowald, Axel; Demetrius, Lloyd

    2005-04-07

    Analytical studies of evolutionary processes based on the demographic parameter entropy-a measure of the uncertainty in the age of the mother of a randomly chosen newborn-show that evolutionary changes in entropy are contingent on environmental constraints and can be characterized in terms of three tenets: (i) a unidirectional increase in entropy for populations subject to bounded growth constraints; (ii) a unidirectional decrease in entropy for large populations subject to unbounded growth constraints; (iii) random, non-directional change in entropy for small populations subject to unbounded growth constraints. This article aims to assess the robustness of these analytical tenets by computer simulation. The results of the computational study are shown to be consistent with the analytical predictions. Computational analysis, together with complementary empirical studies of evolutionary changes in entropy underscore the universality of the entropic principle as a model of the evolutionary process.

  8. Team learning center design principles

    SciTech Connect

    Daily, B.; Loveland, J.; Whatley, A.

    1995-06-01

    This is a preliminary report of a multi-year collaboration of the authors addressing the subject: Can a facility be designed for team learning and would it improve the efficiency and effectiveness of team interactions? Team learning in this context is a broad definition that covers all activities where small to large groups of people come together to work, to learn, and to share through team activities. Multimedia, networking, such as World Wide Web and other tools, are greatly enhancing the capability of individual learning. This paper addresses the application of technology and design to facilitate group or team learning. Many organizational meetings need tens of people to come together to do work as a large group and then divide into smaller subgroups of five to ten to work and then to return and report and interact with the larger group. Current facilities were not, in general, designed for this type of meeting. Problems with current facilities are defined and a preliminary design solution to many of the identified problems is presented.

  9. Principles of Communicative Task Design.

    ERIC Educational Resources Information Center

    Nunan, David

    The use of the learning task as a basic planning and instructional tool for communicative second language instruction is discussed, and considerations and procedures for designing such tasks are outlined. A task is defined as a piece of classroom work that involves learners in comprehending, manipulating, producing, or interacting in the target…

  10. Training Principles and Program Design

    ERIC Educational Resources Information Center

    Plisk, Steven

    2005-01-01

    This article focuses on standards specific to Domain 3: Physical Preparation and Conditioning of the National Standards for Sport Coaches (NASPE, 2004b). It discusses program design concepts that coaches can apply to prepare athletes for the demands of their sport, and is based on both research and best professional practice. Sport preparation has…

  11. Training Principles and Program Design

    ERIC Educational Resources Information Center

    Plisk, Steven

    2005-01-01

    This article focuses on standards specific to Domain 3: Physical Preparation and Conditioning of the National Standards for Sport Coaches (NASPE, 2004b). It discusses program design concepts that coaches can apply to prepare athletes for the demands of their sport, and is based on both research and best professional practice. Sport preparation has…

  12. Automatic Molecular Design using Evolutionary Techniques

    NASA Technical Reports Server (NTRS)

    Globus, Al; Lawton, John; Wipke, Todd; Saini, Subhash (Technical Monitor)

    1998-01-01

    Molecular nanotechnology is the precise, three-dimensional control of materials and devices at the atomic scale. An important part of nanotechnology is the design of molecules for specific purposes. This paper describes early results using genetic software techniques to automatically design molecules under the control of a fitness function. The fitness function must be capable of determining which of two arbitrary molecules is better for a specific task. The software begins by generating a population of random molecules. The population is then evolved towards greater fitness by randomly combining parts of the better individuals to create new molecules. These new molecules then replace some of the worst molecules in the population. The unique aspect of our approach is that we apply genetic crossover to molecules represented by graphs, i.e., sets of atoms and the bonds that connect them. We present evidence suggesting that crossover alone, operating on graphs, can evolve any possible molecule given an appropriate fitness function and a population containing both rings and chains. Prior work evolved strings or trees that were subsequently processed to generate molecular graphs. In principle, genetic graph software should be able to evolve other graph representable systems such as circuits, transportation networks, metabolic pathways, computer networks, etc.

  13. Principles of Inorganic Materials Design

    NASA Astrophysics Data System (ADS)

    Lalena, John N.; Cleary, David

    2005-04-01

    A unique interdisciplinary approach to inorganic materials design Textbooks intended for the training of chemists in the inorganic materials field often omit many relevant topics. With its interdisciplinary approach, this book fills that gap by presenting concepts from chemistry, physics, materials science, metallurgy, and ceramics in a unified treatment targeted towards the chemistry audience. Semiconductors, metal alloys and intermetallics, as well as ceramic substances are covered. Accordingly, the book should also be useful to students and working professionals in a variety of other disciplines. This book discusses a number of topics that are pertinent to the design of new inorganic materials but are typically not covered in standard solid-state chemistry books. The authors start with an introduction to structure at the mesoscopic level and progress to smaller-length scales. Next, detailed consideration is given to both phenomenological and atomistic-level descriptions of transport properties, the metal-nonmetal transition, magnetic and dielectric properties, optical properties, and mechanical properties. Finally, the authors present introductions to phase equilibria, synthesis, and nanomaterials. Other features include: Worked examples demonstrating concepts unfamiliar to the chemist Extensive references to related literature, leading readers to more in-depth coverage of particular topics Biographies introducing the reader to great contributors to the field of inorganic materials science in the twentieth century With their interdisciplinary approach, the authors have set the groundwork for communication and understanding among professionals in varied disciplines who are involved with inorganic materials engineering. Armed with this publication, students and researchers in inorganic and physical chemistry, physics, materials science, and engineering will be better equipped to face today's complex design challenges. This textbook is appropriate for senior

  14. Ariane 5 - Design principles and development status

    NASA Astrophysics Data System (ADS)

    Hergott, R.

    1990-03-01

    The missions, design principles, main design features, and development status of the Ariane 5 are discussed. The special arrangements made for the launch of commercial payloads and for the Hermes launch are pointed out. The present status of the launch vehicle system, cryotechnic stage, solid propellant booster, upper stage, and vehicle equipment bay are described.

  15. Principles in Call Software Design and Implementation.

    ERIC Educational Resources Information Center

    Gimeno, Ana

    2002-01-01

    Discusses a number of principles to bear in mind when designing and implementing multimedia language learning materials. A general overview is provided on the template approach to designing and creating a multimedia computer assisted language learning package. Examples are given from experience in multimedia development for language learning…

  16. Design Principles for Augmented Reality Learning

    ERIC Educational Resources Information Center

    Dunleavy, Matt

    2014-01-01

    Augmented reality is an emerging technology that utilizes mobile, context-aware devices (e.g., smartphones, tablets) that enable participants to interact with digital information embedded within the physical environment. This overview of design principles focuses on specific strategies that instructional designers can use to develop AR learning…

  17. Design Principles for Augmented Reality Learning

    ERIC Educational Resources Information Center

    Dunleavy, Matt

    2014-01-01

    Augmented reality is an emerging technology that utilizes mobile, context-aware devices (e.g., smartphones, tablets) that enable participants to interact with digital information embedded within the physical environment. This overview of design principles focuses on specific strategies that instructional designers can use to develop AR learning…

  18. Mechatronics design principles for biotechnology product development.

    PubMed

    Mandenius, Carl-Fredrik; Björkman, Mats

    2010-05-01

    Traditionally, biotechnology design has focused on the manufacture of chemicals and biologics. Still, a majority of biotechnology products that appear on the market today is the result of mechanical-electric (mechatronic) construction. For these, the biological components play decisive roles in the design solution; the biological entities are either integral parts of the design, or are transformed by the mechatronic system. This article explains how the development and production engineering design principles used for typical mechanical products can be adapted to the demands of biotechnology products, and how electronics, mechanics and biology can be integrated more successfully. We discuss three emerging areas of biotechnology in which mechatronic design principles can apply: stem cell manufacture, artificial organs, and bioreactors.

  19. An Evolutionary Comparison of the Handicap Principle and Hybrid Equilibrium Theories of Signaling.

    PubMed

    Kane, Patrick; Zollman, Kevin J S

    2015-01-01

    The handicap principle has come under significant challenge both from empirical studies and from theoretical work. As a result, a number of alternative explanations for honest signaling have been proposed. This paper compares the evolutionary plausibility of one such alternative, the "hybrid equilibrium," to the handicap principle. We utilize computer simulations to compare these two theories as they are instantiated in Maynard Smith's Sir Philip Sidney game. We conclude that, when both types of communication are possible, evolution is unlikely to lead to handicap signaling and is far more likely to result in the partially honest signaling predicted by hybrid equilibrium theory.

  20. An Evolutionary Comparison of the Handicap Principle and Hybrid Equilibrium Theories of Signaling

    PubMed Central

    Kane, Patrick; Zollman, Kevin J. S.

    2015-01-01

    The handicap principle has come under significant challenge both from empirical studies and from theoretical work. As a result, a number of alternative explanations for honest signaling have been proposed. This paper compares the evolutionary plausibility of one such alternative, the “hybrid equilibrium,” to the handicap principle. We utilize computer simulations to compare these two theories as they are instantiated in Maynard Smith’s Sir Philip Sidney game. We conclude that, when both types of communication are possible, evolution is unlikely to lead to handicap signaling and is far more likely to result in the partially honest signaling predicted by hybrid equilibrium theory. PMID:26348617

  1. Design Principles for New Systems of Assessment

    ERIC Educational Resources Information Center

    Shepard, Lorrie A.; Penuel, William R.; Davidson, Kristen L.

    2017-01-01

    The Every Student Succeeds Act grants states new flexibility to create more balanced assessment systems with a greater role for formative assessment. Drawing on lessons learned over three decades of research and reform, we argue that state and local leaders should take the lead in designing new assessments guided by two core principles: First,…

  2. Ten Principles of Effective School Design

    ERIC Educational Resources Information Center

    New Visions for Public Schools, 2006

    2006-01-01

    This brief document offers ten principles of effective school design. They are: (1) Clear Focus and High Expectations for staff and students are defining features of an effective school; (2) A Rigorous Instructional Program provides equitable opportunities to learn and enables every student to master challenging content, skills, and learning…

  3. Design Principles of the ESCOT Math Environments.

    ERIC Educational Resources Information Center

    Underwood, Jody S.; Hoadley, Chris; DiGiano, Chris; Stohl, Hollylynne; Hollebrands, Karen

    This paper describes the Educational Software Components of Tomorrow (ESCOT) project. The focus of the project was on principles that support problem-solving and learner-centered design issues, and the purpose was to garner lessons from a large educational software development project to share with the learning sciences and other interested…

  4. New robotics: design principles for intelligent systems.

    PubMed

    Pfeifer, Rolf; Iida, Fumiya; Bongard, Josh

    2005-01-01

    New robotics is an approach to robotics that, in contrast to traditional robotics, employs ideas and principles from biology. While in the traditional approach there are generally accepted methods (e. g., from control theory), designing agents in the new robotics approach is still largely considered an art. In recent years, we have been developing a set of heuristics, or design principles, that on the one hand capture theoretical insights about intelligent (adaptive) behavior, and on the other provide guidance in actually designing and building systems. In this article we provide an overview of all the principles but focus on the principles of ecological balance, which concerns the relation between environment, morphology, materials, and control, and sensory-motor coordination, which concerns self-generated sensory stimulation as the agent interacts with the environment and which is a key to the development of high-level intelligence. As we argue, artificial evolution together with morphogenesis is not only "nice to have" but is in fact a necessary tool for designing embodied agents.

  5. Principles for Designing Language Teaching Materials.

    ERIC Educational Resources Information Center

    Nunan, David

    1988-01-01

    Key principles for designing language teaching materials are presented. They relate to the following: links with the curriculum; authenticity regarding text and task; stimulating interaction; allowing focus on formal aspects of the language; encouraging development of learning skills; and applying language skills to the wider world. (10…

  6. Devising Principles of Design for Numeracy Tasks

    ERIC Educational Resources Information Center

    Geiger, Vince; Forgasz, Helen; Goos, Merrilyn; Bennison, Anne

    2014-01-01

    Numeracy is a fundamental component of the Australian National Curriculum as a General Capability identified in each F-10 subject. In this paper, we consider the principles of design necessary for the development of numeracy tasks specific to subjects other than mathematics--in this case, the subject of English. We explore the nature of potential…

  7. Principles of Space Plasma Wave Instrument Design

    NASA Technical Reports Server (NTRS)

    Gurnett, Donald A.

    1998-01-01

    Space plasma waves span the frequency range from somewhat below the ion cyclotron frequency to well above the electron cyclotron frequency and plasma frequency. Because of the large frequency range involved, the design of space plasma wave instrumentation presents many interesting challenges. This chapter discusses the principles of space plasma wave instrument design. The topics covered include: performance requirements, electric antennas, magnetic antennas, and signal processing. Where appropriate, comments are made on the likely direction of future developments.

  8. A Protocol for Evaluating Contextual Design Principles

    PubMed Central

    Stamps, Arthur

    2014-01-01

    This paper explains how scientific data can be incorporated into urban design decisions, such as evaluating contextual design principles. The recommended protocols are based on the Cochrane Reviews that have been widely used in medical research. The major concepts of a Cochrane Review are explained, as well as the underlying mathematics. The underlying math is meta-analysis. Data are reported for three applications and seven contextual design policies. It is suggested that use of the Cochrane protocols will be of great assistance to planners by providing scientific data that can be used to evaluate the efficacies of contextual design policies prior to implementing those policies. PMID:25431448

  9. A Bright Future for Evolutionary Methods in Drug Design.

    PubMed

    Le, Tu C; Winkler, David A

    2015-08-01

    Most medicinal chemists understand that chemical space is extremely large, essentially infinite. Although high-throughput experimental methods allow exploration of drug-like space more rapidly, they are still insufficient to fully exploit the opportunities that such large chemical space offers. Evolutionary methods can synergistically blend automated synthesis and characterization methods with computational design to identify promising regions of chemical space more efficiently. We describe how evolutionary methods are implemented, and provide examples of published drug development research in which these methods have generated molecules with increased efficacy. We anticipate that evolutionary methods will play an important role in future drug discovery.

  10. Designing Interactive Learning Environments: An Approach from First Principles

    ERIC Educational Resources Information Center

    Scott, Bernard; Cong, Chunyu

    2007-01-01

    Purpose: Today's technology supports the design of more and more sophisticated interactive learning environments. This paper aims to argue that such design should develop from first principles. Design/methodology/approach: In the paper by first principles is meant: learning theory and principles of course design. These principles are briefly…

  11. Designing for Success: Developing Engineers Who Consider Universal Design Principles

    ERIC Educational Resources Information Center

    Bigelow, Kimberly Edginton

    2012-01-01

    Engineers must design for a diverse group of potential users of their products; however, engineering curricula rarely include an emphasis on universal design principles. This research article details the effectiveness of a design project implemented in a first-year engineering course in an effort to raise awareness of the need for engineers to be…

  12. Multiobjective satisfaction within an interactive evolutionary design environment.

    PubMed

    Parmee, I C; Cvetković, D; Watson, A H; Bonham, C R

    2000-01-01

    The paper introduces the concept of an Interactive Evolutionary Design System (IEDS) that supports the engineering designer during the conceptual/preliminary stages of the design process. Requirement during these early stages relates primarily to design search and exploration across a poorly defined space as the designer's knowledge base concerning the problem area develops. Multiobjective satisfaction plays a major role, and objectives are likely to be ill-defined and their relative importance uncertain. Interactive evolutionary search and exploration provides information to the design team that contributes directly to their overall understanding of the problem domain in terms of relevant objectives, constraints, and variable ranges. This paper describes the development of certain elements within an interactive evolutionary conceptual design environment that allows off-line processing of such information leading to a redefinition of the design space. Such redefinition may refer to the inclusion or removal of objectives, changes concerning their relative importance, or the reduction of variable ranges as a better understanding of objective sensitivity is established. The emphasis, therefore, moves from a multiobjective optimization over a preset number of generations to a relatively continuous interactive evolutionary search that results in the optimal definition of both the variable and objective space relating to the design problem at hand. The paper describes those elements of the IEDS relating to such multiobjective information gathering and subsequent design space redefinition.

  13. Principles and techniques for designing precision machines

    SciTech Connect

    Hale, Layton Carter

    1999-02-01

    This thesis is written to advance the reader's knowledge of precision-engineering principles and their application to designing machines that achieve both sufficient precision and minimum cost. It provides the concepts and tools necessary for the engineer to create new precision machine designs. Four case studies demonstrate the principles and showcase approaches and solutions to specific problems that generally have wider applications. These come from projects at the Lawrence Livermore National Laboratory in which the author participated: the Large Optics Diamond Turning Machine, Accuracy Enhancement of High- Productivity Machine Tools, the National Ignition Facility, and Extreme Ultraviolet Lithography. Although broad in scope, the topics go into sufficient depth to be useful to practicing precision engineers and often fulfill more academic ambitions. The thesis begins with a chapter that presents significant principles and fundamental knowledge from the Precision Engineering literature. Following this is a chapter that presents engineering design techniques that are general and not specific to precision machines. All subsequent chapters cover specific aspects of precision machine design. The first of these is Structural Design, guidelines and analysis techniques for achieving independently stiff machine structures. The next chapter addresses dynamic stiffness by presenting several techniques for Deterministic Damping, damping designs that can be analyzed and optimized with predictive results. Several chapters present a main thrust of the thesis, Exact-Constraint Design. A main contribution is a generalized modeling approach developed through the course of creating several unique designs. The final chapter is the primary case study of the thesis, the Conceptual Design of a Horizontal Machining Center.

  14. An Evolutionary Approach to Designing Neural Networks

    DTIC Science & Technology

    1990-09-01

    the face of a changing environment. Our hypothesis is that the principles of biological evolution and population genetics provide the basis for such...capabilities in massively parallel architecture using population genetics theory REPRESENTATIVE RESEARCH AT SRI (since 1985) Analysis of images of mail...of 1-D and 2-D signals Medical applications of signal processing Image Processing, Department Manager, Elco Robotics Population genetics and

  15. Automated protein design: Landmarks and operational principles.

    PubMed

    Kumar, Anil; Ranbhor, Ranjit; Patel, Kirti; Ramakrishnan, Vibin; Durani, Susheel

    2017-05-01

    Protein design has an eventful history spanning over three decades, with handful of success stories reported, and numerous failures not reported. Design practices have benefited tremendously from improvements in computer hardware and advances in scientific algorithms. Though protein folding problem still remains unsolved, the possibility of having multiple sequence solutions for a single fold makes protein design a more tractable problem than protein folding. One of the most significant advancement in this area is the implementation of automated design algorithms on pre-defined templates or completely new folds, optimized through deterministic and heuristic search algorithms. This progress report provides a succinct presentation of important landmarks in automated design attempts, followed by brief account of operational principles in automated design methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Regulatory RNA design through evolutionary computation and strand displacement.

    PubMed

    Rostain, William; Landrain, Thomas E; Rodrigo, Guillermo; Jaramillo, Alfonso

    2015-01-01

    The discovery and study of a vast number of regulatory RNAs in all kingdoms of life over the past decades has allowed the design of new synthetic RNAs that can regulate gene expression in vivo. Riboregulators, in particular, have been used to activate or repress gene expression. However, to accelerate and scale up the design process, synthetic biologists require computer-assisted design tools, without which riboregulator engineering will remain a case-by-case design process requiring expert attention. Recently, the design of RNA circuits by evolutionary computation and adapting strand displacement techniques from nanotechnology has proven to be suited to the automated generation of DNA sequences implementing regulatory RNA systems in bacteria. Herein, we present our method to carry out such evolutionary design and how to use it to create various types of riboregulators, allowing the systematic de novo design of genetic control systems in synthetic biology.

  17. Y-12 Sustainable Design Principles for Building Design and Construction

    SciTech Connect

    Jackson, J. G.

    2008-11-01

    B&W Y-12 is committed to modernizing the Y-12 complex to meet future needs with a sustainable and responsive infrastructure and to integrating sustainability principles and practices into Y-12 work (Y72-001, B&W Y-12 Environmental, Safety and Health Policy). This commitment to sustainability and specifically sustainable design of buildings is also incorporated into Presidential Executive Orders (EO), DOE Orders (DOE O), and goals. Sustainable building design is an approach to design, construct, and operate facilities in an efficient and environmentally sound manner that will produce a healthful, resource-efficient and productive working environment that is inherently protective of the environment. The DOE has established the following 5 Guiding Principles for High Performance Sustainable Building (HPSB), and has issued directives that require Y-12 to incorporate the principles and a number of supporting specific practices and techniques into building design, construction and renovation projects: (1) Employ Integrated Design Principles; (2) Optimize Energy Performance; (3) Protect and Conserve Water; (4) Enhance Indoor Environmental Quality; and (5) Reduce Environmental Impact of Materials. The purpose of this document is to present the required sustainable building principles, practices and techniques, summarize the key drivers for incorporating them into Y-12 projects, and present additional recommendations and resources that can be used to support sustainable buildings to enhance the environmental and economic performance of the Y-12 Complex.

  18. Design principles for shift current photovoltaics

    PubMed Central

    Cook, Ashley M.; M. Fregoso, Benjamin; de Juan, Fernando; Coh, Sinisa; Moore, Joel E.

    2017-01-01

    While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W−1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells. PMID:28120823

  19. Design principles for shift current photovoltaics.

    PubMed

    Cook, Ashley M; M Fregoso, Benjamin; de Juan, Fernando; Coh, Sinisa; Moore, Joel E

    2017-01-25

    While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W(-1). Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells.

  20. Design principles for shift current photovoltaics

    NASA Astrophysics Data System (ADS)

    Cook, Ashley M.; M. Fregoso, Benjamin; de Juan, Fernando; Coh, Sinisa; Moore, Joel E.

    2017-01-01

    While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W-1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells.

  1. DESIGN PRINCIPLES OF INSECT AND VERTEBRATE VISUAL SYSTEMS

    PubMed Central

    Sanes, Joshua R.; Zipursky, S. Lawrence

    2010-01-01

    A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have provided strong support for Cajal’s view. In parallel, genetic studies have revealed some common molecular mechanisms controlling development of vertebrate and fly visual systems and suggested that they share a common evolutionary origin. Here, we review these shared features, focusing on the first several layers - retina, optic tectum (superior colliculus) and lateral geniculate nucleus in vertebrates, and retina, lamina and medulla in fly. We argue that vertebrate and fly visual circuits utilize common design principles, and that taking advantage of this phylogenetic conservation will speed progress in elucidating both functional strategies and developmental mechanisms, as has already occurred in other areas of neurobiology ranging from electrical signaling and synaptic plasticity to neurogenesis and axon guidance. PMID:20399726

  2. Morphogen rules: design principles of gradient-mediated embryo patterning.

    PubMed

    Briscoe, James; Small, Stephen

    2015-12-01

    The Drosophila blastoderm and the vertebrate neural tube are archetypal examples of morphogen-patterned tissues that create precise spatial patterns of different cell types. In both tissues, pattern formation is dependent on molecular gradients that emanate from opposite poles. Despite distinct evolutionary origins and differences in time scales, cell biology and molecular players, both tissues exhibit striking similarities in the regulatory systems that establish gene expression patterns that foreshadow the arrangement of cell types. First, signaling gradients establish initial conditions that polarize the tissue, but there is no strict correspondence between specific morphogen thresholds and boundary positions. Second, gradients initiate transcriptional networks that integrate broadly distributed activators and localized repressors to generate patterns of gene expression. Third, the correct positioning of boundaries depends on the temporal and spatial dynamics of the transcriptional networks. These similarities reveal design principles that are likely to be broadly applicable to morphogen-patterned tissues.

  3. Morphogen rules: design principles of gradient-mediated embryo patterning

    PubMed Central

    Briscoe, James; Small, Stephen

    2015-01-01

    The Drosophila blastoderm and the vertebrate neural tube are archetypal examples of morphogen-patterned tissues that create precise spatial patterns of different cell types. In both tissues, pattern formation is dependent on molecular gradients that emanate from opposite poles. Despite distinct evolutionary origins and differences in time scales, cell biology and molecular players, both tissues exhibit striking similarities in the regulatory systems that establish gene expression patterns that foreshadow the arrangement of cell types. First, signaling gradients establish initial conditions that polarize the tissue, but there is no strict correspondence between specific morphogen thresholds and boundary positions. Second, gradients initiate transcriptional networks that integrate broadly distributed activators and localized repressors to generate patterns of gene expression. Third, the correct positioning of boundaries depends on the temporal and spatial dynamics of the transcriptional networks. These similarities reveal design principles that are likely to be broadly applicable to morphogen-patterned tissues. PMID:26628090

  4. Design principles of insect and vertebrate visual systems.

    PubMed

    Sanes, Joshua R; Zipursky, S Lawrence

    2010-04-15

    A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have provided strong support for Cajal's view. In parallel, genetic studies have revealed some common molecular mechanisms controlling development of vertebrate and fly visual systems and suggested that they share a common evolutionary origin. Here, we review these shared features, focusing on the first several layers-retina, optic tectum (superior colliculus), and lateral geniculate nucleus in vertebrates; and retina, lamina, and medulla in fly. We argue that vertebrate and fly visual circuits utilize common design principles and that taking advantage of this phylogenetic conservation will speed progress in elucidating both functional strategies and developmental mechanisms, as has already occurred in other areas of neurobiology ranging from electrical signaling and synaptic plasticity to neurogenesis and axon guidance.

  5. Design principles for therapeutic angiogenic materials

    NASA Astrophysics Data System (ADS)

    Briquez, Priscilla S.; Clegg, Lindsay E.; Martino, Mikaël M.; Gabhann, Feilim Mac; Hubbell, Jeffrey A.

    2016-01-01

    Despite extensive research, pro-angiogenic drugs have failed to translate clinically, and therapeutic angiogenesis, which has potential in the treatment of various cardiovascular diseases, remains a major challenge. Physiologically, angiogenesis — the process of blood-vessel growth from existing vasculature — is regulated by a complex interplay of biophysical and biochemical cues from the extracellular matrix (ECM), angiogenic factors and multiple cell types. The ECM can be regarded as the natural 3D material that regulates angiogenesis. Here, we leverage knowledge of ECM properties to derive design rules for engineering pro-angiogenic materials. We propose that pro-angiogenic materials should be biomimetic, incorporate angiogenic factors and mimic cooperative interactions between growth factors and the ECM. We highlight examples of material designs that demonstrate these principles and considerations for designing better angiogenic materials.

  6. Generative Representations for Computer-Automated Evolutionary Design

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2006-01-01

    With the increasing computational power of computers, software design systems are progressing from being tools for architects and designers to express their ideas to tools capable of creating designs under human guidance. One of the main limitations for these computer-automated design systems is the representation with which they encode designs. If the representation cannot encode a certain design, then the design system cannot produce it. To be able to produce new types of designs, and not just optimize pre-defined parameterizations, evolutionary design systems must use generative representations. Generative representations are assembly procedures, or algorithms, for constructing a design thereby allowing for truly novel design solutions to be encoded. In addition, by enabling modularity, regularity and hierarchy, the level of sophistication that can be evolved is increased. We demonstrate the advantages of generative representations on two different design domains: the evolution of spacecraft antennas and the evolution of 3D objects.

  7. Evolutionary Design and Simulation of a Tube Crawling Inspection Robot

    NASA Technical Reports Server (NTRS)

    Craft, Michael; Howsman, Tom; ONeil, Daniel; Howell, Joe T. (Technical Monitor)

    2002-01-01

    The Space Robotics Assembly Team Simulation (SpaceRATS) is an expansive concept that will hopefully lead to a space flight demonstration of a robotic team cooperatively assembling a system from its constitutive parts. A primary objective of the SpaceRATS project is to develop a generalized evolutionary design approach for multiple classes of robots. The portion of the overall SpaceRats program associated with the evolutionary design and simulation of an inspection robot's morphology is the subject of this paper. The vast majority of this effort has concentrated on the use and modification of Darwin2K, a robotic design and simulation software package, to analyze the design of a tube crawling robot. This robot is designed for carrying out inspection duties in relatively inaccessible locations within a liquid rocket engine similar to the SSME. A preliminary design of the tube crawler robot was completed, and the mechanical dynamics of the system were simulated. An evolutionary approach to optimizing a few parameters of the system was utilized, resulting in a more optimum design.

  8. Study of Screen Design Principles for Visualizing Medical Records.

    PubMed

    Fujita, Kenichiro; Takemura, Tadamasa; Kuroda, Tomohiro

    2015-01-01

    To improve UX of EMR/EHR, the screen design principles for the visualization are required. Through the study of common attributes of medical records, we present four principles and show three screen designs by applying them.

  9. Automatic design of decision-tree algorithms with evolutionary algorithms.

    PubMed

    Barros, Rodrigo C; Basgalupp, Márcio P; de Carvalho, André C P L F; Freitas, Alex A

    2013-01-01

    This study reports the empirical analysis of a hyper-heuristic evolutionary algorithm that is capable of automatically designing top-down decision-tree induction algorithms. Top-down decision-tree algorithms are of great importance, considering their ability to provide an intuitive and accurate knowledge representation for classification problems. The automatic design of these algorithms seems timely, given the large literature accumulated over more than 40 years of research in the manual design of decision-tree induction algorithms. The proposed hyper-heuristic evolutionary algorithm, HEAD-DT, is extensively tested using 20 public UCI datasets and 10 microarray gene expression datasets. The algorithms automatically designed by HEAD-DT are compared with traditional decision-tree induction algorithms, such as C4.5 and CART. Experimental results show that HEAD-DT is capable of generating algorithms which are significantly more accurate than C4.5 and CART.

  10. Two Eyes, 3D: Stereoscopic Design Principles

    NASA Astrophysics Data System (ADS)

    Price, Aaron; Subbarao, M.; Wyatt, R.

    2013-01-01

    Two Eyes, 3D is a NSF-funded research project about how people perceive highly spatial objects when shown with 2D or stereoscopic ("3D") representations. As part of the project, we produced a short film about SN 2011fe. The high definition film has been rendered in both 2D and stereoscopic formats. It was developed according to a set of stereoscopic design principles we derived from the literature and past experience producing and studying stereoscopic films. Study participants take a pre- and post-test that involves a spatial cognition assessment and scientific knowledge questions about Type-1a supernovae. For the evaluation, participants use iPads in order to record spatial manipulation of the device and look for elements of embodied cognition. We will present early results and also describe the stereoscopic design principles and the rationale behind them. All of our content and software is available under open source licenses. More information is at www.twoeyes3d.org.

  11. Designing novel kinases using evolutionary sequence analysis

    NASA Astrophysics Data System (ADS)

    Mody, Areez; Weiner, Joan; Iyer, Lakshman; Ramanathan, Sharad

    2006-03-01

    Cellular pathways with new functions are thought to arise from the duplication and divergence of proteins in existing pathways. The MAP kinase pathways in eukaryotes provide one example of this. These pathways consist of the MAP kinase proteins which are responsible for evoking the correct response to external stimuli. In the yeast Saccharomyces cerevisiae these pathways detect pheromones, osmolar stresses and nutrient levels, leading the cell into dramatic changes of morphology. Despite being homologous to each other, the MAP kinase proteins show specificity of function. We investigate the nature of the amino acid sequences conferring this specificity. To this end, we i) search the sequences of similar proteins in other Eukaryote species, ii) make a study of simple theoretical models exploring the constraints felt by these protein segments and iii) experimentally construct, a large suite of hybrid proteins made of segments taken from the homologous proteins. These are then expressed in Yeast cells to see what function they are able to perform. Particularly we also ask whether it is possible to design a new kinase protein possessing new function and specificity.

  12. Robust Design of Biological Circuits: Evolutionary Systems Biology Approach

    PubMed Central

    Chen, Bor-Sen; Hsu, Chih-Yuan; Liou, Jing-Jia

    2011-01-01

    Artificial gene circuits have been proposed to be embedded into microbial cells that function as switches, timers, oscillators, and the Boolean logic gates. Building more complex systems from these basic gene circuit components is one key advance for biologic circuit design and synthetic biology. However, the behavior of bioengineered gene circuits remains unstable and uncertain. In this study, a nonlinear stochastic system is proposed to model the biological systems with intrinsic parameter fluctuations and environmental molecular noise from the cellular context in the host cell. Based on evolutionary systems biology algorithm, the design parameters of target gene circuits can evolve to specific values in order to robustly track a desired biologic function in spite of intrinsic and environmental noise. The fitness function is selected to be inversely proportional to the tracking error so that the evolutionary biological circuit can achieve the optimal tracking mimicking the evolutionary process of a gene circuit. Finally, several design examples are given in silico with the Monte Carlo simulation to illustrate the design procedure and to confirm the robust performance of the proposed design method. The result shows that the designed gene circuits can robustly track desired behaviors with minimal errors even with nontrivial intrinsic and external noise. PMID:22187523

  13. Robust design of biological circuits: evolutionary systems biology approach.

    PubMed

    Chen, Bor-Sen; Hsu, Chih-Yuan; Liou, Jing-Jia

    2011-01-01

    Artificial gene circuits have been proposed to be embedded into microbial cells that function as switches, timers, oscillators, and the Boolean logic gates. Building more complex systems from these basic gene circuit components is one key advance for biologic circuit design and synthetic biology. However, the behavior of bioengineered gene circuits remains unstable and uncertain. In this study, a nonlinear stochastic system is proposed to model the biological systems with intrinsic parameter fluctuations and environmental molecular noise from the cellular context in the host cell. Based on evolutionary systems biology algorithm, the design parameters of target gene circuits can evolve to specific values in order to robustly track a desired biologic function in spite of intrinsic and environmental noise. The fitness function is selected to be inversely proportional to the tracking error so that the evolutionary biological circuit can achieve the optimal tracking mimicking the evolutionary process of a gene circuit. Finally, several design examples are given in silico with the Monte Carlo simulation to illustrate the design procedure and to confirm the robust performance of the proposed design method. The result shows that the designed gene circuits can robustly track desired behaviors with minimal errors even with nontrivial intrinsic and external noise.

  14. EvoOligo: oligonucleotide probe design with multiobjective evolutionary algorithms.

    PubMed

    Shin, Soo-Yong; Lee, In-Hee; Cho, Young-Min; Yang, Kyung-Ae; Zhang, Byoung-Tak

    2009-12-01

    Probe design is one of the most important tasks in successful deoxyribonucleic acid microarray experiments. We propose a multiobjective evolutionary optimization method for oligonucleotide probe design based on the multiobjective nature of the probe design problem. The proposed multiobjective evolutionary approach has several distinguished features, compared with previous methods. First, the evolutionary approach can find better probe sets than existing simple filtering methods with fixed threshold values. Second, the multiobjective approach can easily incorporate the user's custom criteria or change the existing criteria. Third, our approach tries to optimize the combination of probes for the given set of genes, in contrast to other tools that independently search each gene for qualifying probes. Lastly, the multiobjective optimization method provides various sets of probe combinations, among which the user can choose, depending on the target application. The proposed method is implemented as a platform called EvoOligo and is available for service on the web. We test the performance of EvoOligo by designing probe sets for 19 types of Human Papillomavirus and 52 genes in the Arabidopsis Calmodulin multigene family. The design results from EvoOligo are proven to be superior to those from well-known existing probe design tools, such as OligoArray and OligoWiz.

  15. Using evolutionary computations to understand the design and evolution of gene and cell regulatory networks.

    PubMed

    Spirov, Alexander; Holloway, David

    2013-07-15

    This paper surveys modeling approaches for studying the evolution of gene regulatory networks (GRNs). Modeling of the design or 'wiring' of GRNs has become increasingly common in developmental and medical biology, as a means of quantifying gene-gene interactions, the response to perturbations, and the overall dynamic motifs of networks. Drawing from developments in GRN 'design' modeling, a number of groups are now using simulations to study how GRNs evolve, both for comparative genomics and to uncover general principles of evolutionary processes. Such work can generally be termed evolution in silico. Complementary to these biologically-focused approaches, a now well-established field of computer science is Evolutionary Computations (ECs), in which highly efficient optimization techniques are inspired from evolutionary principles. In surveying biological simulation approaches, we discuss the considerations that must be taken with respect to: (a) the precision and completeness of the data (e.g. are the simulations for very close matches to anatomical data, or are they for more general exploration of evolutionary principles); (b) the level of detail to model (we proceed from 'coarse-grained' evolution of simple gene-gene interactions to 'fine-grained' evolution at the DNA sequence level); (c) to what degree is it important to include the genome's cellular context; and (d) the efficiency of computation. With respect to the latter, we argue that developments in computer science EC offer the means to perform more complete simulation searches, and will lead to more comprehensive biological predictions. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Evolutionary Connectionism: Algorithmic Principles Underlying the Evolution of Biological Organisation in Evo-Devo, Evo-Eco and Evolutionary Transitions.

    PubMed

    Watson, Richard A; Mills, Rob; Buckley, C L; Kouvaris, Kostas; Jackson, Adam; Powers, Simon T; Cox, Chris; Tudge, Simon; Davies, Adam; Kounios, Loizos; Power, Daniel

    2016-01-01

    The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term "evolutionary connectionism" to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary

  17. Basic design principles of colorimetric vision systems

    NASA Astrophysics Data System (ADS)

    Mumzhiu, Alex M.

    1998-10-01

    Color measurement is an important part of overall production quality control in textile, coating, plastics, food, paper and other industries. The color measurement instruments such as colorimeters and spectrophotometers, used for production quality control have many limitations. In many applications they cannot be used for a variety of reasons and have to be replaced with human operators. Machine vision has great potential for color measurement. The components for color machine vision systems, such as broadcast quality 3-CCD cameras, fast and inexpensive PCI frame grabbers, and sophisticated image processing software packages are available. However the machine vision industry has only started to approach the color domain. The few color machine vision systems on the market, produced by the largest machine vision manufacturers have very limited capabilities. A lack of understanding that a vision based color measurement system could fail if it ignores the basic principles of colorimetry is the main reason for the slow progress of color vision systems. the purpose of this paper is to clarify how color measurement principles have to be applied to vision systems and how the electro-optical design features of colorimeters have to be modified in order to implement them for vision systems. The subject of this presentation far exceeds the limitations of a journal paper so only the most important aspects will be discussed. An overview of the major areas of applications for colorimetric vision system will be discussed. Finally, the reasons why some customers are happy with their vision systems and some are not will be analyzed.

  18. Design principles of shift current photovoltaics

    NASA Astrophysics Data System (ADS)

    Cook, Ashley; Fregoso, Benjamin; de Juan, Fernando; Moore, Joel

    While the basic principles and limitations of conventional solar cells are well understood, relatively little attention has gone toward evaluating and maximizing the potential efficiency of photovoltaic devices based on shift currents. In this work, a sum rule approach is introduced and used to outline design principles for optimizing shift currents for photon energies near the band gap, which depend on wavefunctions via Berry connections as well as standard band structure. Using these we identify two new classes of shift current photovoltaics, ferroelectric polymer films and orthorhombic monochalcogenides, both of which exhibit peak photoresponsivities larger than predictions for previously-known photovoltaics of this type. Using physically-motivated tight-binding models, the full frequency dependent response of these materials is obtained. Exploring the phase space of these models, we find photoresponsivities that can exceed 100 mA/W. These results show that considering the microscopic origin of shift current via effective models allows one to improve the possible efficiency of devices using this mechanism and better grasp their potential to compete with conventional solar cells. This work was completed with the support of an NSERC Michael Smith Foreign Study Supplement.

  19. Design principles of photosynthetic light-harvesting.

    PubMed

    Fleming, Graham R; Schlau-Cohen, Gabriela S; Amarnath, Kapil; Zaks, Julia

    2012-01-01

    Photosynthetic organisms are capable of harvesting solar energy with near unity quantum efficiency. Even more impressively, this efficiency can be regulated in response to the demands of photosynthetic reactions and the fluctuating light-levels of natural environments. We discuss the distinctive design principles through which photosynthetic light-harvesting functions. These emergent properties of photosynthesis appear both within individual pigment-protein complexes and in how these complexes integrate to produce a functional, regulated apparatus that drives downstream photochemistry. One important property is how the strong interactions and resultant quantum coherence, produced by the dense packing of photosynthetic pigments, provide a tool to optimize for ultrafast, directed energy transfer. We also describe how excess energy is quenched to prevent photodamage under high-light conditions, which we investigate through theory and experiment. We conclude with comments on the potential of using these features to improve solar energy devices.

  20. Buck-boost converter feedback controller design via evolutionary search

    NASA Astrophysics Data System (ADS)

    Sundareswaran, K.; Devi, V.; Nadeem, S. K.; Sreedevi, V. T.; Palani, S.

    2010-11-01

    Buck-boost converters are switched power converters. The model of the converter system varies from the ON state to the OFF state and hence traditional methods of controller design based on approximate transfer function models do not yield good dynamic response at different operating points of the converter system. This article attempts to design a feedback controller for a buck-boost type dc-dc converter using a genetic algorithm. The feedback controller design is perceived as an optimisation problem and a robust controller is estimated through an evolutionary search. Extensive simulation and experimental results provided in the article show the effectiveness of the new approach.

  1. Hybrid multiobjective evolutionary design for artificial neural networks.

    PubMed

    Goh, Chi-Keong; Teoh, Eu-Jin; Tan, Kay Chen

    2008-09-01

    Evolutionary algorithms are a class of stochastic search methods that attempts to emulate the biological process of evolution, incorporating concepts of selection, reproduction, and mutation. In recent years, there has been an increase in the use of evolutionary approaches in the training of artificial neural networks (ANNs). While evolutionary techniques for neural networks have shown to provide superior performance over conventional training approaches, the simultaneous optimization of network performance and architecture will almost always result in a slow training process due to the added algorithmic complexity. In this paper, we present a geometrical measure based on the singular value decomposition (SVD) to estimate the necessary number of neurons to be used in training a single-hidden-layer feedforward neural network (SLFN). In addition, we develop a new hybrid multiobjective evolutionary approach that includes the features of a variable length representation that allow for easy adaptation of neural networks structures, an architectural recombination procedure based on the geometrical measure that adapts the number of necessary hidden neurons and facilitates the exchange of neuronal information between candidate designs, and a microhybrid genetic algorithm ( microHGA) with an adaptive local search intensity scheme for local fine-tuning. In addition, the performances of well-known algorithms as well as the effectiveness and contributions of the proposed approach are analyzed and validated through a variety of data set types.

  2. Evolutionary design of interfacial phase change van der Waals heterostructures.

    PubMed

    Kalikka, Janne; Zhou, Xilin; Behera, Jitendra; Nannicini, Giacomo; Simpson, Robert E

    2016-10-27

    We use an evolutionary algorithm to explore the design space of hexagonal Ge2Sb2Te5; a van der Waals layered two dimensional crystal heterostructure. The Ge2Sb2Te5 structure is more complicated than previously thought. Predominant features include layers of Ge3Sb2Te6 and Ge1Sb2Te4 two dimensional crystals that interact through Te-Te van der Waals bonds. Interestingly, (Ge/Sb)-Te-(Ge/Sb)-Te alternation is a common feature for the most stable structures of each generation's evolution. This emergent rule provides an important structural motif that must be included in the design of high performance Sb2Te3-GeTe van der Waals heterostructure superlattices with interfacial atomic switching capability. The structures predicted by the algorithm agree well with experimental measurements on highly oriented, and single crystal Ge2Sb2Te5 samples. By analysing the evolutionary algorithm optimised structures, we show that diffusive atomic switching is probable by Ge atoms undergoing a transition at the van der Waals interface from layers of Ge3Sb2Te6 to Ge1Sb2Te4 thus producing two blocks of Ge2Sb2Te5. Evolutionary methods present an efficient approach to explore the enormous multi-dimensional design parameter space of van der Waals bonded heterostructure superlattices.

  3. Evolutionary design of discrete controllers for hybrid mechatronic systems

    NASA Astrophysics Data System (ADS)

    Dupuis, Jean-Francois; Fan, Zhun; Goodman, Erik

    2015-01-01

    This paper investigates the issue of evolutionary design of controllers for hybrid mechatronic systems. Finite State Automaton (FSA) is selected as the representation for a discrete controller due to its interpretability, fast execution speed and natural extension to a statechart, which is very popular in industrial applications. A case study of a two-tank system is used to demonstrate that the proposed evolutionary approach can lead to a successful design of an FSA controller for the hybrid mechatronic system, represented by a hybrid bond graph. Generalisation of the evolved FSA controller to unknown control targets is also tested. Further, a comparison with another type of controller, a lookahead controller, is conducted, with advantages and disadvantages of each discussed. The comparison sheds light on which type of controller representation is a better choice to use in various stages of the evolutionary design of controllers for hybrid mechatronic systems. Finally, some important future research directions are pointed out, leading to the major work of the succeeding part of the research.

  4. Using evolutionary computations to understand the design and evolution of gene and cell regulatory networks

    PubMed Central

    Spirov, Alexander; Holloway, David

    2013-01-01

    This paper surveys modeling approaches for studying the evolution of gene regulatory networks (GRNs). Modeling of the design or ‘wiring’ of GRNs has become increasingly common in developmental and medical biology, as a means of quantifying gene-gene interactions, the response to perturbations, and the overall dynamic motifs of networks. Drawing from developments in GRN ‘design’ modeling, a number of groups are now using simulations to study how GRNs evolve, both for comparative genomics and to uncover general principles of evolutionary processes. Such work can generally be termed evolution in silico. Complementary to these biologically-focused approaches, a now well-established field of computer science is Evolutionary Computations (EC), in which highly efficient optimization techniques are inspired from evolutionary principles. In surveying biological simulation approaches, we discuss the considerations that must be taken with respect to: a) the precision and completeness of the data (e.g. are the simulations for very close matches to anatomical data, or are they for more general exploration of evolutionary principles); b) the level of detail to model (we proceed from ‘coarse-grained’ evolution of simple gene-gene interactions to ‘fine-grained’ evolution at the DNA sequence level); c) to what degree is it important to include the genome’s cellular context; and d) the efficiency of computation. With respect to the latter, we argue that developments in computer science EC offer the means to perform more complete simulation searches, and will lead to more comprehensive biological predictions. PMID:23726941

  5. A Review: Principles of Design and Analysis of Learning Systems

    ERIC Educational Resources Information Center

    Durney, Carl H.

    1973-01-01

    Analyzes a traditional and an innovative course in terms of learning principles, involving Erickson's management methods and Gagne's learning activities. Suggests that learning systems should be designed by applying all principles rather than emphasizing one or two of them. (CC)

  6. ACIS design compliance with principle accelerator safety interlock design requirements.

    SciTech Connect

    Knott, M.

    2005-02-23

    Prior to and during the design of the APS's Access Control Interlock System (ACIS), an effort was made to insure that the design complied with the relevant DOE and ANL requirements as well as those set forth in other recognized documents then in circulation. A paragraph-by-paragraph listing of the requirements (in some cases, recommended practices) and the corresponding ACIS design features was compiled for use by the review committees then in place. This tabulation was incorporated in the APS Safety Analysis Document (SAD) as Appendix A. With the evolutionary changes that have occurred to the APS and to the documents referenced, some of the details of these compliances have evolved as well. It has been decided to maintain the SAD as a ''living'' document, editing it in close time proximity to the evolving APS. Since Appendix A depicted the ACIS's original design compliance to an also-evolving set of documents, it was decided to remove Appendix A but to retain it as a reference document. This LS Note now contains that set of original design compliances. As the APS and the ACIS continue to evolve, the changes made will be subject to internal review and approval and will always be subject to the requirements set forth by the DOE and ANL.

  7. Design principles of interfacial thermal conductance

    NASA Astrophysics Data System (ADS)

    Polanco, Carlos; Rastgarkafshgarkolaei, Rouzbeh; Zhang, Jingjie; Le, Nam; Norris, Pamela; Ghosh, Avik

    We explore fundamental principles to design the thermal conductance across solid interfaces by changing the composition and disorder of an intermediate matching layer. In absence of phonon-phonon interactions, the layer addition involves two competing effects that influence the conductance. The layer can act as an impedance matching 'bridge' to increase the mode-averaged phonon transmission. However, it also reduces the relevant modes that conserve their momenta transverse to the interface, so that the net result depends on features such as the overlap of conserving modes and the dispersivity of the transverse subbands. Moving into the interacting anharmonic regime, we find that the added layer aids conductance when the decreased resistances at the contact-layer boundaries compensate for the layer resistance. In fact, we show that the maximum conductance corresponds to an exact matching of the two separate contact-layer resistances. For instance, if we vary just the atomic mass across layers, then maximum conductance happens when the intervening layer mass is the geometric mean of the contact masses. We conjecture that the best interfacial layer is one that is compositionally graded into many geometric means - in other words, an exponential variation in thermal impedance.

  8. Using biological principles to design MEMS

    NASA Astrophysics Data System (ADS)

    Scherge, M.; Gorb, S. N.

    2000-09-01

    In micromechanics the handling and positioning of microparts involves sophisticated assembly procedures and a good understanding of microtribological phenomena. Due to the very low object mass, adhesion between the micropart and the handling tool (usually a mechanical gripper) becomes a performance-limiting factor. Adhesion effects can be even larger than the force that frees the micropart from the handling tool thus making correct positioning impossible. Many useful design principles for optimized adhesion properties can be found in biological systems. In this paper adhesion between the foot of an insect and a surface was evaluated. The attachment pads of the great green bush cricket (Tettigonia viridissima) - used to attach the insect safely to a variety of different surfaces - were investigated to draw conclusions that could be implemented in future technical microsystems. It is shown that the attachment pads are flexible micromechanical units capable of self-adjusting to different scales of roughness. The erratic influence of capillary action due to adsorbed water is presumably suppressed by a hydrophobic layer on the pads. Attaching and releasing mechanisms as well as accurate measurement of the adhesion force are discussed in detail.

  9. Perceptual and Design Principles for Effective Interactive Visualisations

    NASA Astrophysics Data System (ADS)

    Hicks, Martin

    This chapter reviews some influential theories and design principles for informing the design of effective interactive visualisation user interfaces (UIs). Several theories and principles are reviewed encompassing perceptual organisation, data graphics, and design principles (e.g. Gestalt laws, data graphics, interaction design and Human-Computer Interaction guidelines). Some example case studies are included in order to illustrate the principal benefits of applying these design principles within the UI. The objective of this review of the principles and approaches to graphical presentation is to highlight how they can be used to emphasise and reveal the most salient properties of a data visualisation, whether it is intended for scientific or for business use. Certain principles are further proposed as a generic set of guidelines for the design of interactive visualisations, which are summarised at the end of the chapter.

  10. Human Factors Principles in Information Dashboard Design

    SciTech Connect

    Hugo, Jacques V.; St. Germain, Shawn

    2016-06-01

    strategic modernization program at a nuclear power plant where legacy systems are upgraded to advanced digital technologies through a systematic process that links human factors principles to the systems engineering process. This approach will help to create an integrated control room architecture beyond what is possible for individual subsystem upgrades alone. In addition, several human factors design and evaluation methods were used to develop the end-state concept, including interactive sessions with operators in INL’s Human System Simulation Laboratory, three-dimensional modeling to visualize control board changes.

  11. Design principles for advanced carburized bearing steels

    NASA Astrophysics Data System (ADS)

    Wright, James Anthony

    Rolling contact fatigue behavior of carburized C69-1 steel was measured and analyzed using an NTN rolling contact fatigue tester. Core precipitation of nanoscale 6 phase in C69-2 steel was measured with 1DAP microanalysis. Precipitation behavior in M50NiL-0.38C was examined using small angle neutron scattering, transmission electron microscopy, one-dimensional atom probe microanalysis, three-dimensional atom probe microanalysis, Vickers microhardness, and ThermoCalc thermodynamic modeling software. Five different carbide phases were tentatively identified as Fe3C, M2C, MC, M6C, and M 23C6. The hardness evolution was modeled with the measured microstructural data and scaled to measured microhardness. A multiphase precipitation model was developed to predict the volume fraction of each phase during tempering. Stress relaxation during tempering of M50NiL-0.38C was shown to be controlled by carbide precipitation kinetics using tensile and split-ring methods. From these experiments design principles for advanced carburized steels were deduced. Because of their role in fatigue nucleation, no primary carbides should be present after solution treatment. A single phase M2C precipitate dispersion should be over-aged to be slightly larger than its peak strength state to avoid cyclic shearing and improve rolling contact fatigue resistance. Other carbide phases can be avoided because they are less efficient strengtheners than the M2C phase. The embrittling sigma phase should be avoided in the low carbon core by reducing the driving force for precipitation. The steel should have some residual austenite in the carburized case after quenching from the solution treatment; this retained austenite should be completely transformed upon a cryogenic treatment after tempering to restore favorable, residual compressive stress in the case.

  12. Evolutionary design of a fuzzy classifier from data.

    PubMed

    Chang, Xiaoguang; Lilly, John H

    2004-08-01

    Genetic algorithms show powerful capabilities for automatically designing fuzzy systems from data, but many proposed methods must be subjected to some minimal structure assumptions, such as rule base size. In this paper, we also address the design of fuzzy systems from data. A new evolutionary approach is proposed for deriving a compact fuzzy classification system directly from data without any a priori knowledge or assumptions on the distribution of the data. At the beginning of the algorithm, the fuzzy classifier is empty with no rules in the rule base and no membership functions assigned to fuzzy variables. Then, rules and membership functions are automatically created and optimized in an evolutionary process. To accomplish this, parameters of the variable input spread inference training (VISIT) algorithm are used to code fuzzy systems on the training data set. Therefore, we can derive each individual fuzzy system via the VISIT algorithm, and then search the best one via genetic operations. To evaluate the fuzzy classifier, a fuzzy expert system acts as the fitness function. This fuzzy expert system can effectively evaluate the accuracy and compactness at the same time. In the application section, we consider four benchmark classification problems: the iris data, wine data, Wisconsin breast cancer data, and Pima Indian diabetes data. Comparisons of our method with others in the literature show the effectiveness of the proposed method.

  13. Design Principles for Learning to Guide Teacher Walk Throughs

    ERIC Educational Resources Information Center

    Feeney, Eric

    2014-01-01

    Design principles for learning provide a framework for creating a collaborative culture, structures, and dispositions as part of an effective professional learning system to continuously inform and improve teaching and learning. Design principles engage teachers in continuous, accelerated, and sustained learning about instructional practices in…

  14. De novo drug design using multiobjective evolutionary graphs.

    PubMed

    Nicolaou, Christos A; Apostolakis, Joannis; Pattichis, Costas S

    2009-02-01

    Drug discovery and development is a complex, lengthy process, and failure of a candidate molecule can occur as a result of a combination of reasons, such as poor pharmacokinetics, lack of efficacy, or toxicity. Successful drug candidates necessarily represent a compromise between the numerous, sometimes competing objectives so that the benefits to patients outweigh potential drawbacks and risks. De novo drug design involves searching an immense space of feasible, druglike molecules to select those with the highest chances of becoming drugs using computational technology. Traditionally, de novo design has focused on designing molecules satisfying a single objective, such as similarity to a known ligand or an interaction score, and ignored the presence of the multiple objectives required for druglike behavior. Recently, methods have appeared in the literature that attempt to design molecules satisfying multiple predefined objectives and thereby produce candidate solutions with a higher chance of serving as viable drug leads. This paper describes the Multiobjective Evolutionary Graph Algorithm (MEGA), a new multiobjective optimization de novo design algorithmic framework that can be used to design structurally diverse molecules satisfying one or more objectives. The algorithm combines evolutionary techniques with graph-theory to directly manipulate graphs and perform an efficient global search for promising solutions. In the Experimental Section we present results from the application of MEGA for designing molecules that selectively bind to a known pharmaceutical target using the ChillScore interaction score family. The primary constraints applied to the design are based on the identified structure of the protein target and a known ligand currently marketed as a drug. A detailed explanation of the key elements of the specific implementation of the algorithm is given, including the methods for obtaining molecular building blocks, evolving the chemical graphs, and

  15. Evolutionary algorithms applied to reliable communication network design

    NASA Astrophysics Data System (ADS)

    Nesmachnow, Sergio; Cancela, Hector; Alba, Enrique

    2007-10-01

    Several evolutionary algorithms (EAs) applied to a wide class of communication network design problems modelled under the generalized Steiner problem (GSP) are evaluated. In order to provide a fault-tolerant design, a solution to this problem consists of a preset number of independent paths linking each pair of potentially communicating terminal nodes. This usually requires considering intermediate non-terminal nodes (Steiner nodes), which are used to ensure path redundancy, while trying to minimize the overall cost. The GSP is an NP-hard problem for which few algorithms have been proposed. This article presents a comparative study of pure and hybrid EAs applied to the GSP, codified over MALLBA, a general purpose library for combinatorial optimization. The algorithms were tested on several GSPs, and asset efficient numerical results are reported for both serial and distributed models of the evaluated algorithms.

  16. Teaching Elements and Principles of Bridge Design

    ERIC Educational Resources Information Center

    Beck, Charles

    2005-01-01

    Bridge construction is a popular classroom activity. However, the basic principles of tension, compression, and counterbalance are not always clearly represented and defined. The common materials used to construct model bridges, such as straws, toothpicks, Legos[TM], and building blocks, are often too flexible or stationary to demonstrate the…

  17. Teaching Elements and Principles of Bridge Design

    ERIC Educational Resources Information Center

    Beck, Charles

    2005-01-01

    Bridge construction is a popular classroom activity. However, the basic principles of tension, compression, and counterbalance are not always clearly represented and defined. The common materials used to construct model bridges, such as straws, toothpicks, Legos[TM], and building blocks, are often too flexible or stationary to demonstrate the…

  18. The Value of the Operational Principle in Instructional Design

    ERIC Educational Resources Information Center

    Gibbons, Andrew S.

    2009-01-01

    Formal design studies are increasing our insight into design processes, including those of instructional design. Lessons are being learned from other design fields, and new techniques and concepts can be imported as they are demonstrated effective. The purpose of this article is to introduce a design concept--the "operational principle"--for…

  19. The Value of the Operational Principle in Instructional Design

    ERIC Educational Resources Information Center

    Gibbons, Andrew S.

    2009-01-01

    Formal design studies are increasing our insight into design processes, including those of instructional design. Lessons are being learned from other design fields, and new techniques and concepts can be imported as they are demonstrated effective. The purpose of this article is to introduce a design concept--the "operational principle"--for…

  20. An evolutionary based Bayesian design optimization approach under incomplete information

    NASA Astrophysics Data System (ADS)

    Srivastava, Rupesh; Deb, Kalyanmoy

    2013-02-01

    Design optimization in the absence of complete information about uncertain quantities has been recently gaining consideration, as expensive repetitive computation tasks are becoming tractable due to the invention of faster and parallel computers. This work uses Bayesian inference to quantify design reliability when only sample measurements of the uncertain quantities are available. A generalized Bayesian reliability based design optimization algorithm has been proposed and implemented for numerical as well as engineering design problems. The approach uses an evolutionary algorithm (EA) to obtain a trade-off front between design objectives and reliability. The Bayesian approach provides a well-defined link between the amount of available information and the reliability through a confidence measure, and the EA acts as an efficient optimizer for a discrete and multi-dimensional objective space. Additionally, a GPU-based parallelization study shows computational speed-up of close to 100 times in a simulated scenario wherein the constraint qualification checks may be time consuming and could render a sequential implementation that can be impractical for large sample sets. These results show promise for the use of a parallel implementation of EAs in handling design optimization problems under uncertainties.

  1. Evolutionary mechanics: new engineering principles for the emergence of flexibility in a dynamic and uncertain world.

    PubMed

    Whitacre, James M; Rohlfshagen, Philipp; Bender, Axel; Yao, Xin

    2012-09-01

    Engineered systems are designed to deftly operate under predetermined conditions yet are notoriously fragile when unexpected perturbations arise. In contrast, biological systems operate in a highly flexible manner; learn quickly adequate responses to novel conditions, and evolve new routines and traits to remain competitive under persistent environmental change. A recent theory on the origins of biological flexibility has proposed that degeneracy-the existence of multi-functional components with partially overlapping functions-is a primary determinant of the robustness and adaptability found in evolved systems. While degeneracy's contribution to biological flexibility is well documented, there has been little investigation of degeneracy design principles for achieving flexibility in systems engineering. Actually, the conditions that can lead to degeneracy are routinely eliminated in engineering design. With the planning of transportation vehicle fleets taken as a case study, this article reports evidence that degeneracy improves the robustness and adaptability of a simulated fleet towards unpredicted changes in task requirements without incurring costs to fleet efficiency. We find that degeneracy supports faster rates of design adaptation and ultimately leads to better fleet designs. In investigating the limitations of degeneracy as a design principle, we consider decision-making difficulties that arise from degeneracy's influence on fleet complexity. While global decision-making becomes more challenging, we also find degeneracy accommodates rapid distributed decision-making leading to (near-optimal) robust system performance. Given the range of conditions where favorable short-term and long-term performance outcomes are observed, we propose that degeneracy may fundamentally alter the propensity for adaptation and is useful within different engineering and planning contexts.

  2. Universal Design: Process, Principles, and Applications

    ERIC Educational Resources Information Center

    Burgstahler, Sheryl

    2009-01-01

    Designing any product or environment involves the consideration of many factors, including aesthetics, engineering options, environmental issues, safety concerns, industry standards, and cost. Typically, designers focus their attention on the average user. In contrast, universal design (UD), according to the Center for Universal Design," is…

  3. Enhancing the Therapy Experience Using Principles of Video Game Design.

    PubMed

    Folkins, John Wm; Brackenbury, Tim; Krause, Miriam; Haviland, Allison

    2016-02-01

    This article considers the potential benefits that applying design principles from contemporary video games may have on enhancing therapy experiences. Six principles of video game design are presented, and their relevance for enriching clinical experiences is discussed. The motivational and learning benefits of each design principle have been discussed in the education literature as having positive impacts on student motivation and learning and are related here to aspects of clinical practice. The essential experience principle suggests connecting all aspects of the experience around a central emotion or cognitive connection. The discovery principle promotes indirect learning in focused environments. The risk-taking principle addresses the uncertainties clients face when attempting newly learned skills in novel situations. The generalization principle encourages multiple opportunities for skill transfer. The reward system principle directly relates to the scaffolding of frequent and varied feedback in treatment. Last, the identity principle can assist clients in using their newly learned communication skills to redefine self-perceptions. These principles highlight areas for research and interventions that may be used to reinforce or advance current practice.

  4. How eco-evolutionary principles can guide tree breeding and tree biotechnology for enhanced productivity.

    PubMed

    Franklin, Oskar; Palmroth, Sari; Näsholm, Torgny

    2014-11-01

    Tree breeding and biotechnology can enhance forest productivity and help alleviate the rising pressure on forests from climate change and human exploitation. While many physiological processes and genes are targeted in search of genetically improved tree productivity, an overarching principle to guide this search is missing. Here, we propose a method to identify the traits that can be modified to enhance productivity, based on the differences between trees shaped by natural selection and 'improved' trees with traits optimized for productivity. We developed a tractable model of plant growth and survival to explore such potential modifications under a range of environmental conditions, from non-water limited to severely drought-limited sites. We show how key traits are controlled by a trade-off between productivity and survival, and that productivity can be increased at the expense of long-term survival by reducing isohydric behavior (stomatal regulation of leaf water potential) and allocation to defense against pests compared with native trees. In contrast, at dry sites occupied by naturally drought-resistant trees, the model suggests a better strategy may be to select trees with slightly lower wood density than the native trees and to augment isohydric behavior and allocation to defense. Thus, which traits to modify, and in which direction, depend on the original tree species or genotype, the growth environment and wood-quality versus volume production preferences. In contrast to this need for customization of drought and pest resistances, consistent large gains in productivity for all genotypes can be obtained if root traits can be altered to reduce competition for water and nutrients. Our approach illustrates the potential of using eco-evolutionary theory and modeling to guide plant breeding and genetic technology in selecting target traits in the quest for higher forest productivity.

  5. Universal Design in Education: Principles and Applications

    ERIC Educational Resources Information Center

    Burgstahler, Sheryl

    2009-01-01

    While courses, technology, and student services are typically designed for the narrow range of characteristics of the average student, the practice of universal design in education (UDE) considers people with a broad range of characteristics in the design of all educational products and environments. "UDE" goes beyond accessible design…

  6. Evolutionary Design of a Phased Array Antenna Element

    NASA Technical Reports Server (NTRS)

    Globus, Al; Linden, Derek; Lohn, Jason

    2006-01-01

    We present an evolved S-band phased array antenna element design that meets the requirements of NASA's TDRS-C communications satellite scheduled for launch early next decade. The original specification called for two types of elements, one for receive only and one for transmit/receive. We were able to evolve a single element design that meets both specifications thereby simplifying the antenna and reducing testing and integration costs. The highest performance antenna found using a genetic algorithm and stochastic hill-climbing has been fabricated and tested. Laboratory results are largely consistent with simulation. Researchers have been investigating evolutionary antenna design and optimization since the early 1990s, and the field has grown in recent years its computer speed has increased and electromagnetic simulators have improved. Many antenna types have been investigated, including wire antennas, antenna arrays and quadrifilar helical antennas. In particular, our laboratory evolved a wire antenna design for NASA's Space Technology 5 (ST5) spacecraft. This antenna has been fabricated, tested, and is scheduled for launch on the three spacecraft in 2006.

  7. Evolutionary Design of a Robotic Material Defect Detection System

    NASA Technical Reports Server (NTRS)

    Ballard, Gary; Howsman, Tom; Craft, Mike; ONeil, Daniel; Steincamp, Jim; Howell, Joe T. (Technical Monitor)

    2002-01-01

    During the post-flight inspection of SSME engines, several inaccessible regions must be disassembled to inspect for defects such as cracks, scratches, gouges, etc. An improvement to the inspection process would be the design and development of very small robots capable of penetrating these inaccessible regions and detecting the defects. The goal of this research was to utilize an evolutionary design approach for the robotic detection of these types of defects. A simulation and visualization tool was developed prior to receiving the hardware as a development test bed. A small, commercial off-the-shelf (COTS) robot was selected from several candidates as the proof of concept robot. The basic approach to detect the defects was to utilize Cadmium Sulfide (CdS) sensors to detect changes in contrast of an illuminated surface. A neural network, optimally designed utilizing a genetic algorithm, was employed to detect the presence of the defects (cracks). By utilization of the COTS robot and US sensors, the research successfully demonstrated that an evolutionarily designed neural network can detect the presence of surface defects.

  8. Utilization of Design Principles for Hybrid Learning Configurations by Interprofessional Design Teams

    ERIC Educational Resources Information Center

    Cremers, Petra H. M.; Wals, Arjen E. J.; Wesselink, Renate; Mulder, Martin

    2017-01-01

    Educational design research yields design knowledge, often in the form of design principles or guidelines that provide the rationale or "know-why" for the design of educational interventions. As such, design principles can be utilized by designers in contexts other than the research context in which they were generated. Although research…

  9. Epidemiology and Clinical Research Design, Part 2: Principles.

    PubMed

    Manja, Veena; Lakshminrusimha, Satyan

    This is the third article covering core knowledge in scholarly activities for neonatal physicians. In this article, we discuss various principles of epidemiology and clinical research design. A basic knowledge of these principles is necessary for conducting clinical research and for proper interpretation of studies. This article reviews bias and confounding, causation, incidence and prevalence, decision analysis, cost-effectiveness, sensitivity analysis, and measurement.

  10. Toward Instructional Design Principles: Inducing Faraday's Law with Contrasting Cases

    ERIC Educational Resources Information Center

    Kuo, Eric; Wieman, Carl E.

    2016-01-01

    Although physics education research (PER) has improved instructional practices, there are not agreed upon principles for designing effective instructional materials. Here, we illustrate how close comparison of instructional materials could support the development of such principles. Specifically, in discussion sections of a large, introductory…

  11. Toward Instructional Design Principles: Inducing Faraday's Law with Contrasting Cases

    ERIC Educational Resources Information Center

    Kuo, Eric; Wieman, Carl E.

    2016-01-01

    Although physics education research (PER) has improved instructional practices, there are not agreed upon principles for designing effective instructional materials. Here, we illustrate how close comparison of instructional materials could support the development of such principles. Specifically, in discussion sections of a large, introductory…

  12. Proficiency-Based Curriculum Design: Principles Derived from Government Experience.

    ERIC Educational Resources Information Center

    Lowe, Pardee, Jr.

    1985-01-01

    Describes principles for designing a proficiency-based course to prepare students for the ACTFL/ETS Advanced Plus/Superior level according to Interagency Language Roundtable guidelines. Proposes ways to combine grammatical and "functional/notional" syllabuses with a proficiency approach. Examines the implications of these principles for…

  13. Multidisciplinary Multiobjective Optimal Design for Turbomachinery Using Evolutionary Algorithm

    NASA Technical Reports Server (NTRS)

    2005-01-01

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

  14. On Polymorphic Circuits and Their Design Using Evolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Stoica, Adrian; Zebulum, Ricardo; Keymeulen, Didier; Lohn, Jason; Clancy, Daniel (Technical Monitor)

    2002-01-01

    This paper introduces the concept of polymorphic electronics (polytronics) - referring to electronics with superimposed built-in functionality. A function change does not require switches/reconfiguration as in traditional approaches. Instead the change comes from modifications in the characteristics of devices involved in the circuit, in response to controls such as temperature, power supply voltage (VDD), control signals, light, etc. The paper illustrates polytronic circuits in which the control is done by temperature, morphing signals, and VDD respectively. Polytronic circuits are obtained by evolutionary design/evolvable hardware techniques. These techniques are ideal for the polytronics design, a new area that lacks design guidelines, know-how,- yet the requirements/objectives are easy to specify and test. The circuits are evolved/synthesized in two different modes. The first mode explores an unstructured space, in which transistors can be interconnected freely in any arrangement (in simulations only). The second mode uses a Field Programmable Transistor Array (FPTA) model, and the circuit topology is sought as a mapping onto a programmable architecture (these experiments are performed both in simulations and on FPTA chips). The experiments demonstrated the synthesis. of polytronic circuits by evolution. The capacity of storing/hiding "extra" functions provides for watermark/invisible functionality, thus polytronics may find uses in intelligence/security applications.

  15. A design methodology for evolutionary air transportation networks

    NASA Astrophysics Data System (ADS)

    Yang, Eunsuk

    The air transportation demand at large hubs in the U.S. is anticipated to double in the near future. Current runway construction plans at selected airports can relieve some capacity and delay problems, but many are doubtful that this solution is sufficient to accommodate the anticipated demand growth in the National Airspace System (NAS). With the worsening congestion problem, it is imperative to seek alternative solutions other than costly runway constructions. In this respect, many researchers and organizations have been building models and performing analyses of the NAS. However, the complexity and size of the problem results in an overwhelming task for transportation system modelers. This research seeks to compose an active design algorithm for an evolutionary airline network model so as to include network specific control properties. An airline network designer, referred to as a network architect, can use this tool to assess the possibilities of gaining more capacity by changing the network configuration. Since the Airline Deregulation Act of 1978, the airline service network has evolved into a distinct Hub-and-Spoke (H&S) network. Enplanement demand on the H&S network is the sum of Origin-Destination (O-D) demand and transfer demand. Even though the flight or enplanement demand is a function of O-D demand and passenger routings on the airline network, the distinction between enplanement and O-D demand is not often made. Instead, many demand forecast practices in current days are based on scale-ups from the enplanements, which include the demand to and from transferring network hubs. Based on this research, it was found that the current demand prediction practice can be improved by dissecting enplanements further into smaller pieces of information. As a result, enplanement demand is decomposed into intrinsic and variable parts. The proposed intrinsic demand model is based on the concept of 'true' O-D demand which includes the direction of each round trip

  16. On the search for design principles in biological systems.

    PubMed

    Poyatos, Juan F

    2012-01-01

    The search for basic concepts and underlying principles was at the core of the systems approach to science and technology. This approach was somehow abandoned in mainstream biology after its initial proposal, due to the rise and success of molecular biology. This situation has changed. The accumulated knowledge of decades of molecular studies in combination with new technological advances, while further highlighting the intricacies of natural systems, is also bringing back the quest-for-principles research program. Here, I present two lessons that I derived from my own quest: the importance of studying biological information processing to identify common principles in seemingly unrelated contexts and the adequacy of using known design principles at one level of biological organization as a valuable tool to help recognizing principles at an alternative one. These and additional lessons should contribute to the ultimate goal of establishing principles able to integrate the many scales of biological complexity.

  17. Design Principles to Accommodate Older Adults

    PubMed Central

    Farage, Miranda A.; Miller, Kenneth W.; Ajayi, Funmi; Hutchins, Deborah

    2012-01-01

    The global population is aging. In many industrial countries, almost one in five people are over age 65. As people age, gradual changes ensue in vision, hearing, balance, coordination, and memory. Products, communication materials, and the physical environment must be thoughtfully designed to meet the needs of people of all ages. This article summarizes normal changes in sensory function, mobility, balance, memory, and attention that occur with age. It presents practical guidelines that allow design professionals to accommodate these changes and better meet the needs of older adults. Designing for older adults is inclusive design: it accommodates a range of physical and cognitive abilities and promotes simplicity, flexibility, and ease of use for people of any age. PMID:22980147

  18. Design principles to accommodate older adults.

    PubMed

    Farage, Miranda A; Miller, Kenneth W; Ajayi, Funmi; Hutchins, Deborah

    2012-02-29

    The global population is aging. In many industrial countries, almost one in five people are over age 65. As people age, gradual changes ensue in vision, hearing, balance, coordination, and memory. Products, communication materials, and the physical environment must be thoughtfully designed to meet the needs of people of all ages. This article summarizes normal changes in sensory function, mobility, balance, memory, and attention that occur with age. It presents practical guidelines that allow design professionals to accommodate these changes and better meet the needs of older adults. Designing for older adults is inclusive design: it accommodates a range of physical and cognitive abilities and promotes simplicity, flexibility, and ease of use for people of any age.

  19. Universal Design for Online Courses: Applying Principles to Pedagogy

    ERIC Educational Resources Information Center

    Rao, Kavita; Edelen-Smith, Patricia; Wailehua, Cat-Uyen

    2015-01-01

    Universal design (UD) educational frameworks provide useful guidelines for designing accessible learning environments with the intention of supporting students with and without disabilities. This article describes how one university instructor defined and applied the principles of Universal Instructional Design (UID) to pedagogy, while designing…

  20. Universal Design for Online Courses: Applying Principles to Pedagogy

    ERIC Educational Resources Information Center

    Rao, Kavita; Edelen-Smith, Patricia; Wailehua, Cat-Uyen

    2015-01-01

    Universal design (UD) educational frameworks provide useful guidelines for designing accessible learning environments with the intention of supporting students with and without disabilities. This article describes how one university instructor defined and applied the principles of Universal Instructional Design (UID) to pedagogy, while designing…

  1. Conceptual Learning in a Principled Design Problem Solving Environment

    ERIC Educational Resources Information Center

    Prusak, Naomi; Hershkowitz, Rina; Schwarz, Baruch B.

    2013-01-01

    To what extent can instructional design be based on principles for instilling a culture of problem solving and conceptual learning? This is the main focus of the study described in this paper, in which third grade students participated in a one-year course designed to foster problem solving and mathematical reasoning. The design relied on five…

  2. [Design and optical principles of multifocal lenses].

    PubMed

    Auffarth, G U; Rabsilber, T M; Kohnen, T; Holzer, M P

    2008-06-01

    Multifocal intraocular lenses (MIOLs) of different designs have been used for more than 20 years in modern cataract surgery. The first IOLs were either refractive 2-3-zone designs or of diffractive concept. All MIOL types, regardless of manufacturer, show reduced contrast sensitivity and increased glare for years. Nevertheless, even first-generation MIOL patients had very good functional results when patient selection, IOL calculation, and surgical techniques were appropriate. Today's gold standard is foldable, aspherical diffractive, or refractive MIOLS. Advancements in technology allow the possibility that MIOLs will be used for aphakia correction as well as presbyopia correction.

  3. Principles of Designing Interpretable Optogenetic Behavior Experiments

    ERIC Educational Resources Information Center

    Allen, Brian D.; Singer, Annabelle C.; Boyden, Edward S.

    2015-01-01

    Over the last decade, there has been much excitement about the use of optogenetic tools to test whether specific cells, regions, and projection pathways are necessary or sufficient for initiating, sustaining, or altering behavior. However, the use of such tools can result in side effects that can complicate experimental design or interpretation.…

  4. Principles of Designing Interpretable Optogenetic Behavior Experiments

    ERIC Educational Resources Information Center

    Allen, Brian D.; Singer, Annabelle C.; Boyden, Edward S.

    2015-01-01

    Over the last decade, there has been much excitement about the use of optogenetic tools to test whether specific cells, regions, and projection pathways are necessary or sufficient for initiating, sustaining, or altering behavior. However, the use of such tools can result in side effects that can complicate experimental design or interpretation.…

  5. Design principles for efficient, repeated jumpgliding.

    PubMed

    Desbiens, Alexis Lussier; Pope, Morgan T; Christensen, David L; Hawkes, Elliot W; Cutkosky, Mark R

    2014-06-01

    Combined jumping and gliding locomotion, or 'jumpgliding', can be an efficient way for small robots or animals to travel over cluttered terrain. This paper presents functional requirements and models for a simple jumpglider which formalize the benefits and limitations of using aerodynamic surfaces to augment jumping ability. Analysis of the model gives insight into design choices and control strategies for higher performance and to accommodate special conditions such as a slippery launching surface. The model informs the design of a robotic platform that can perform repeated jumps using a carbon fiber spring and a pivoting wing. Experiments with two different versions of the platform agree with predictions from the model and demonstrate a significantly greater range, and lower cost-of-transport, than a comparable ballistic jumper.

  6. Design principles of a cooperative robot controller

    NASA Technical Reports Server (NTRS)

    Hayward, Vincent; Hayati, Samad

    1987-01-01

    The paper describes the design of a controller for cooperative robots being designed at McGill University in a collaborative effort with the Jet Propulsion Laboratory. The first part of the paper discusses the background and motivation for multiple arm control. Then, a set of programming primitives, which are based on the RCCL system and which permit a programmer to specify cooperative tasks are described. The first group of primitives are motion primitives which specify asynchronous motions, master/slave motions, and cooperative motions. In the context of cooperative robots, trajectory generation issues will be discussed and the implementation described. A second set of primitives provides for the specification of spatial relationships. The relations between programming and control in the case of multiple robot are examined. Finally, the paper describes the allocation of various tasks among a set of microprocessors sharing a common bus.

  7. SPICA/SAFARI Fourier transform spectrometer mechanism evolutionary design

    NASA Astrophysics Data System (ADS)

    van den Dool, Teun C.; Kruizinga, Bob; Braam, Ben C.; Hamelinck, Roger F. M. M.; Loix, Nicolas; Van Loon, Dennis; Dams, Johan

    2012-09-01

    TNO, together with its partners, have designed a cryogenic scanning mechanism for use in the SAFARI1 Fourier Transform Spectrometer (FTS) on board of the SPICA mission. SPICA is one of the M-class missions competing to be launched in ESA's Cosmic Vision Programme2 in 2022. JAXA3 leads the development of the SPICA satellite and SRON is the prime investigator of the Safari instrument. The FTS scanning mechanism (FTSM) has to meet a 35 mm stroke requirement with an Optical Path Difference resolution of less then 15 nm and must fit in a small volume. It consists of two back-to-back roof-top mirrors mounted on a small carriage, which is moved using a magnetic bearing linear guiding system in combination with a magnetic linear motor serving as the OPD actuator. The FTSM will be used at cryogenic temperatures of 4 Kelvin inducing challenging requirements on the thermal power dissipation and heat leak. The magnetic bearing enables movements over a scanning stroke of 35.5 mm in a small volume. It supports the optics in a free-floating way with no friction, or other non-linearities, with sub-nanometer accuracy. This solution is based on the design of the breadboard ODL (Optical Delay Line) developed for the ESA Darwin mission4 and the MABE mechanism developed by Micromega Dynamics. During the last couple of years the initial design of the SAFARI instrument, as described in an earlier SPIE 2010 paper5, was adapted by the SAFARI team in an evolutionary way to meet the changing requirements of the SPICA payload module. This presentation will focus on the evolution of the FTSM to meet these changing requirements. This work is supported by the Netherlands Space Office (NSO).

  8. Exploiting evolutionary principles to prolong tumor control in preclinical models of breast cancer

    PubMed Central

    Enriquez-Navas, Pedro M.; Kam, Yoonseok; Das, Tuhin; Hassan, Sabrina; Silva, Ariosto; Foroutan, Parastou; Ruiz, Epifanio; Martinez, Gary; Minton, Susan; Gillies, Robert J.; Gatenby, Robert A.

    2016-01-01

    Conventional cancer treatment strategies assume that maximum patient benefit is achieved through maximum killing of tumor cells. However, by eliminating the therapy-sensitive population, this strategy accelerates emergence of resistant clones that proliferate unopposed by competitors—an evolutionary phenomenon termed “competitive release.” We present an evolution-guided treatment strategy designed to maintain a stable population of chemosensitive cells that limit proliferation of resistant clones by exploiting the fitness cost of the resistant phenotype. We treated MDA-MB-231/luc triple-negative and MCF7 estrogen receptor–positive (ER+) breast cancers growing orthotopically in a mouse mammary fat pad with paclitaxel, using algorithms linked to tumor response monitored by magnetic resonance imaging. We found that initial control required more intensive therapy with regular application of drug to deflect the exponential tumor growth curve onto a plateau. Dose-skipping algorithms during this phase were less successful than variable dosing algorithms. However, once initial tumor control was achieved, it was maintained with progressively smaller drug doses. In 60 to 80% of animals, continued decline in tumor size permitted intervals as long as several weeks in which no treatment was necessary. Magnetic resonance images and histological analysis of tumors controlled by adaptive therapy demonstrated increased vascular density and less necrosis, suggesting that vascular normalization resulting from enforced stabilization of tumor volume may contribute to ongoing tumor control with lower drug doses. Our study demonstrates that an evolution-based therapeutic strategy using an available chemotherapeutic drug and conventional clinical imaging can prolong the progression-free survival in different preclinical models of breast cancer. PMID:26912903

  9. Parsimonious design principles for motor unit models.

    PubMed

    Ban, Lan; Shapiro, Nicholas P; Lee, Robert H

    2007-01-01

    Motor units are known to display type-specific differences in passive and active electrical properties, and attempts to predict motor unit type based on the measurement of membrane properties have been rather successful. Quantitative models of motoneurons have also grown in complexity and their predictive power is predicated upon the accurate description of basic membrane properties. This paper presents results from a modeling study which sought to specify a small and simple set of "design rules" that motoneurons might obey during type-specific differentiation.

  10. Preserving SSC Design Function Using RCM Principles

    SciTech Connect

    Mohammadi, K

    2009-02-04

    Reliability-Centered Maintenance (RCM) can be defined as an approach that employs preventive, predictive, proactive, and reactive maintenance practices and strategies in an integrated manner to increase the probability that a Structure, System, or Component (SSC) will function as designed over its life cycle with optimum maintenance. The goal of RCM is to preserve the SSC intended design function at the lowest cost by developing a maintenance strategy that is supported by sound technical and economic justification. RCM has been used extensively by the aircraft, space, defense, power generation, and manufacturing industries where functional failures of SSCs can have the potential to compromise worker or public safety, cause adverse environmental impact, cause loss of production, and/or result in excessive damage to critical SSCs. This paper provides a framework for performing an RCM analysis in support of DOE Order 430.1A (Life Cycle Asset Management) and DOE Order 420.1B (Facility Safety). The influence of RCM on the various aspects of the maintenance program including the work control process is also discussed.

  11. Design principles for nickel-hydrogen cells and batteries

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.; Manzo, M. A.; Gonzalez-Sanabria, O. D.

    1985-01-01

    Nickel-hydrogen cells and, more recently, bipolar batteries have been built by a variety of organizations. The design principles that have been used by the technology group at the NASA Lewis Research Center draw upon their extensive background in separator technology, alkaline fuel cell technology, and several alkaline cell technology areas. These design principles have been incorporated into both the more contemporary individual pressure vessel (IPV) designs that were pioneered by other groups, as well as the more recent bipolar battery designs using active cooling that are being developed at NASA Lewis Research Center and under contract. These principles are rather straightforward applications of capillary force formalisms, coupled with the slowly developing data base resulting from careful post test analyses. The objective of this overall effort is directed towards the low-Earth-orbit (LEO) application where the cycle life requirements are much more severe than the geosynchronous-orbit (GEO) application. A summary of the design principles employed is presented along with a discussion of the recommendations for component pore sizes and pore size distributions, as well as suggested materials of construction. These will be made based on our experience in these areas to show how these design principles have been translated into operating hardware.

  12. Design principles for nickel-hydrogen cells and batteries

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.; Manzo, M. A.; Gonzalez-Sanabria, O. D.

    1985-01-01

    Nickel-hydrogen cells and, more recently, bipolar batteries have been built by a variety of organizations. The design principles that have been used by the technology group at the NASA Lewis Research Center draw upon their extensive background in separator technology, alkaline fuel cell technology, and several alkaline cell technology areas. These design principles have been incorporated into both the more contemporary individual pressure vessel (IPV) designs that were pioneered by other groups, as well as the more recent bipolar battery designs using active cooling that are being developed at NASA Lewis Research Center and under contract. These principles are rather straightforward applications of capillary force formalisms, coupled with the slowly developing data base resulting from careful post test analyses. The objective of this overall effort is directed towards the low-earth-orbit (LEO) application where the cycle life requirements are much more severe than the geosynchronous-orbit (GEO) application. A summary of the design principles employed is presented along with a discussion of the recommendations for component pore sizes and pore size distributions, as well as suggested materials of construction. These will be made based on our experience in these areas to show how these design principles have been translated into operating hardware.

  13. Design principles for nickel-hydrogen cells and batteries

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.; Manzo, M. A.; Gonzalez-Sanabria, O. D.

    1985-01-01

    Nickel-hydrogen cells and, more recently, bipolar batteries have been built by a variety of organizations. The design principles that have been used by the technology group at the NASA Lewis Research Center draw upon their extensive background in separator technology, alkaline fuel cell technology, and several alkaline cell technology areas. These design principles have been incorporated into both the more contemporary individual pressure vessel (IPV) designs that were pioneered by other groups, as well as the more recent bipolar battery designs using active cooling that are being developed at NASA Lewis Research Center and under contract. These principles are rather straightforward applications of capillary force formalisms, coupled with the slowly developing data base resulting from careful post test analyses. The objective of this overall effort is directed towards the low-earth-orbit (LEO) application where the cycle life requirements are much more severe than the geosynchronous-orbit (GEO) application. A summary of the design principles employed is presented along with a discussion of the recommendations for component pore sizes and pore size distributions, as well as suggested materials of construction. These will be made based on our experience in these areas to show how these design principles have been translated into operating hardware.

  14. Design Principles of Nonimaging Waveguide Illumination Systems

    NASA Astrophysics Data System (ADS)

    Hough, Thomas Arthur

    1995-01-01

    design and analysis of waveguide illumination systems. As an example, we apply the streamlined design technique to the design of a waveguide illumination system that back -illuminates an automobile radio control panel push button.

  15. Guideline Principles for Designing Astronomy Activities

    NASA Astrophysics Data System (ADS)

    Strubbe, Linda

    2015-03-01

    We astronomy outreachers are passionate about sharing astronomy widely-but many astronomy outreach activities are designed more by how we hope things will work than in a careful intentional way. We also rarely evaluate how well our activities are achieving our goals. As a result, many educational activities must be significantly less effective than they could be. Fortunately, there is a large body of education research on how people learn. If we are serious about sharing astronomy widely and effectively, we must treat our teaching like research: (1) Have clear goals for our outreach, evaluate how well we are achieving our goals, and revise our strategies in light of what we learn; and (2) Use appropriate teaching techniques supported by education research wherever possible.

  16. Design principles for nickel hydrogen cells and batteries

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1985-01-01

    Nickel hydrogen cells, and more recently, bipolar batteries have been built by a variety of organizations. The design principles that have been used by the technology group at the Lewis Research Center draw upon their extensive background in separator technology, alkaline fuel cell technology, and several alkaline cell technology areas. These design principles have been incorporated into both the more contemporary individual pressure vessel (IPV) designs that were pioneered by other groups, as well as the more recent bipolar battery designs using active cooling that are being developed at LeRC and their contractors. These principles are rather straightforward applications of capillary force formalisms, coupled with the slowly developing data base resulting from careful post test analyses. The objective of this overall effort is directed towards the low Earth orbit (LEO) application where the cycle life requirements are much more severe than the geosynchronous orbit (GEO) application. Nickel hydrogen cells have already been successfully flown in an increasing number of GEO missions.

  17. Evaluating Course Design Principles for Multimedia Learning Materials

    ERIC Educational Resources Information Center

    Scott, Bernard; Cong, Chunyu

    2010-01-01

    Purpose: This paper aims to report on evaluation studies of principles of course design for interactive multimedia learning materials. Design/methodology/approach: At the Defence Academy of the UK, Cranfield University has worked with military colleagues to produce multimedia learning materials for courses on "Military Knowledge". The…

  18. Findings in Experimental Psychology as Functioning Principles of Theatrical Design.

    ERIC Educational Resources Information Center

    Caldwell, George

    A gestalt approach to theatrical design seems to provide some ready and stable explanations for a number of issues in the scenic arts. Gestalt serves as the theoretical base for a number of experiments in psychology whose findings appear to delineate the principles of art to be used in scene design. The fundamental notion of gestalt theory…

  19. Pedagogical Screen Design Principles for Graphics in Teleconferencing.

    ERIC Educational Resources Information Center

    McGreal, Rory

    1994-01-01

    Presents principles of screen design applied to the use of visuals on computer monitors during teleconferencing, including formatting; color; text design; lists; graphic images; and charts. Print materials are considered, and strategies to support the interactive use of the computer screen are discussed. (LRW)

  20. Collaborative Knowledge Building Using the Design Principles Database

    ERIC Educational Resources Information Center

    Kali, Yael

    2006-01-01

    In this study we describe a mechanism for supporting a community of learning scientists who are exploring educational technologies by helping them to share and collaboratively build design knowledge. The Design Principles Database (DPD) is intended to be built and used by this community to provide an infrastructure for participants to publish,…

  1. Evaluating Course Design Principles for Multimedia Learning Materials

    ERIC Educational Resources Information Center

    Scott, Bernard; Cong, Chunyu

    2010-01-01

    Purpose: This paper aims to report on evaluation studies of principles of course design for interactive multimedia learning materials. Design/methodology/approach: At the Defence Academy of the UK, Cranfield University has worked with military colleagues to produce multimedia learning materials for courses on "Military Knowledge". The…

  2. Principled Assessment Strategy Design for Online Courses and Programs

    ERIC Educational Resources Information Center

    McCracken, Janet; Cho, Sunah; Sharif, Afsaneh; Wilson, Brian; Miller, Jeff

    2012-01-01

    As the demand for online learning environments grow in higher education, so does the need for systematic application of learning and educational theory to the design, development and delivery of assessment strategies within these environments. However, there is little guidance in the form of principled design frameworks that can assist the design…

  3. Design Principles of Next-Generation Digital Gaming for Education.

    ERIC Educational Resources Information Center

    Squire, Kurt; Jenkins, Henry; Holland, Walter; Miller, Heather; O'Driscoll, Alice; Tan, Katie Philip; Todd, Katie.

    2003-01-01

    Discusses the rapid growth of digital games, describes research at MIT that is exploring the potential of digital games for supporting learning, and offers hypotheses about the design of next-generation educational video and computer games. Highlights include simulations and games; and design principles, including context and using information to…

  4. The Elements and Principles of Design: A Baseline Study

    ERIC Educational Resources Information Center

    Adams, Erin

    2013-01-01

    Critical to the discipline, both professionally and academically, are the fundamentals of interior design. These fundamentals include the elements and principles of interior design: the commonly accepted tools and vocabulary used to create and communicate successful interior environments. Research indicates a lack of consistency in both the…

  5. The Elements and Principles of Design: A Baseline Study

    ERIC Educational Resources Information Center

    Adams, Erin

    2013-01-01

    Critical to the discipline, both professionally and academically, are the fundamentals of interior design. These fundamentals include the elements and principles of interior design: the commonly accepted tools and vocabulary used to create and communicate successful interior environments. Research indicates a lack of consistency in both the…

  6. Design Principles of Next-Generation Digital Gaming for Education.

    ERIC Educational Resources Information Center

    Squire, Kurt; Jenkins, Henry; Holland, Walter; Miller, Heather; O'Driscoll, Alice; Tan, Katie Philip; Todd, Katie.

    2003-01-01

    Discusses the rapid growth of digital games, describes research at MIT that is exploring the potential of digital games for supporting learning, and offers hypotheses about the design of next-generation educational video and computer games. Highlights include simulations and games; and design principles, including context and using information to…

  7. Epidemiology and Clinical Research Design, Part 2: Principles

    PubMed Central

    Manja, Veena; Lakshminrusimha, Satyan

    2015-01-01

    This is the third article covering core knowledge in scholarly activities for neonatal physicians. In this article, we discuss various principles of epidemiology and clinical research design. A basic knowledge of these principles is necessary for conducting clinical research and for proper interpretation of studies. This article reviews bias and confounding, causation, incidence and prevalence, decision analysis, cost-effectiveness, sensitivity analysis, and measurement. PMID:26236171

  8. Dual adaptive control: Design principles and applications

    NASA Technical Reports Server (NTRS)

    Mookerjee, Purusottam

    1988-01-01

    The design of an actively adaptive dual controller based on an approximation of the stochastic dynamic programming equation for a multi-step horizon is presented. A dual controller that can enhance identification of the system while controlling it at the same time is derived for multi-dimensional problems. This dual controller uses sensitivity functions of the expected future cost with respect to the parameter uncertainties. A passively adaptive cautious controller and the actively adaptive dual controller are examined. In many instances, the cautious controller is seen to turn off while the latter avoids the turn-off of the control and the slow convergence of the parameter estimates, characteristic of the cautious controller. The algorithms have been applied to a multi-variable static model which represents a simplified linear version of the relationship between the vibration output and the higher harmonic control input for a helicopter. Monte Carlo comparisons based on parametric and nonparametric statistical analysis indicate the superiority of the dual controller over the baseline controller.

  9. A comparative study of corrugated horn design by evolutionary techniques

    NASA Technical Reports Server (NTRS)

    Hoorfar, A.

    2003-01-01

    Here an evolutionary programming algorithm is used to optimize the pattern of a corrugated circular horn subject to various constraints on return loss, antenna beamwidth, pattern circularity, and low cross polarization.

  10. Multi-objective analysis of a component-based representation within an interactive evolutionary design system

    NASA Astrophysics Data System (ADS)

    Machwe, A. T.; Parmee, I. C.

    2007-07-01

    This article describes research relating to a user-centered evolutionary design system that evaluates both engineering and aesthetic aspects of design solutions during early-stage conceptual design. The experimental system comprises several components relating to user interaction, problem representation, evolutionary search and exploration and online learning. The main focus of the article is the evolutionary aspect of the system when using a single quantitative objective function plus subjective judgment of the user. Additionally, the manner in which the user-interaction aspect affects system output is assessed by comparing Pareto frontiers generated with and without user interaction via a multi-objective evolutionary algorithm (MOEA). A solution clustering component is also introduced and it is shown how this can improve the level of support to the designer when dealing with a complex design problem involving multiple objectives. Supporting results are from the application of the system to the design of urban furniture which, in this case, largely relates to seating design.

  11. Design of an Evolutionary Approach for Intrusion Detection

    PubMed Central

    2013-01-01

    A novel evolutionary approach is proposed for effective intrusion detection based on benchmark datasets. The proposed approach can generate a pool of noninferior individual solutions and ensemble solutions thereof. The generated ensembles can be used to detect the intrusions accurately. For intrusion detection problem, the proposed approach could consider conflicting objectives simultaneously like detection rate of each attack class, error rate, accuracy, diversity, and so forth. The proposed approach can generate a pool of noninferior solutions and ensembles thereof having optimized trade-offs values of multiple conflicting objectives. In this paper, a three-phase, approach is proposed to generate solutions to a simple chromosome design in the first phase. In the first phase, a Pareto front of noninferior individual solutions is approximated. In the second phase of the proposed approach, the entire solution set is further refined to determine effective ensemble solutions considering solution interaction. In this phase, another improved Pareto front of ensemble solutions over that of individual solutions is approximated. The ensemble solutions in improved Pareto front reported improved detection results based on benchmark datasets for intrusion detection. In the third phase, a combination method like majority voting method is used to fuse the predictions of individual solutions for determining prediction of ensemble solution. Benchmark datasets, namely, KDD cup 1999 and ISCX 2012 dataset, are used to demonstrate and validate the performance of the proposed approach for intrusion detection. The proposed approach can discover individual solutions and ensemble solutions thereof with a good support and a detection rate from benchmark datasets (in comparison with well-known ensemble methods like bagging and boosting). In addition, the proposed approach is a generalized classification approach that is applicable to the problem of any field having multiple conflicting

  12. Instructional Audio Guidelines: Four Design Principles to Consider for Every Instructional Audio Design Effort

    ERIC Educational Resources Information Center

    Carter, Curtis W.

    2012-01-01

    This article contends that instructional designers and developers should attend to four particular design principles when creating instructional audio. Support for this view is presented by referencing the limited research that has been done in this area, and by indicating how and why each of the four principles is important to the design process.…

  13. Integrating principles and multidisciplinary projects in design education

    NASA Technical Reports Server (NTRS)

    Nevill, Gale E., Jr.

    1992-01-01

    The critical need to improve engineering design education in the U.S. is presented and a number of actions to achieve that end are discussed. The importance of teaching undergraduates the latest methods and principles through the means of team design in multidisciplinary projects leading to a testable product is emphasized. Desirable training for design instructors is described and techniques for selecting and managing projects that teach effectively are discussed.

  14. Integrating principles and multidisciplinary projects in design education

    NASA Technical Reports Server (NTRS)

    Nevill, Gale E., Jr.

    1992-01-01

    The critical need to improve engineering design education in the U.S. is presented and a number of actions to achieve that end are discussed. The importance of teaching undergraduates the latest methods and principles through the means of team design in multidisciplinary projects leading to a testable product is emphasized. Desirable training for design instructors is described and techniques for selecting and managing projects that teach effectively are discussed.

  15. Applying multimedia design principles enhances learning in medical education.

    PubMed

    Issa, Nabil; Schuller, Mary; Santacaterina, Susan; Shapiro, Michael; Wang, Edward; Mayer, Richard E; DaRosa, Debra A

    2011-08-01

    The Association of American Medical Colleges' Institute for Improving Medical Education's report entitled 'Effective Use of Educational Technology' called on researchers to study the effectiveness of multimedia design principles. These principles were empirically shown to result in superior learning when used with college students in laboratory studies, but have not been studied with undergraduate medical students as participants. A pre-test/post-test control group design was used, in which the traditional-learning group received a lecture on shock using traditionally designed slides and the modified-design group received the same lecture using slides modified in accord with Mayer's principles of multimedia design. Participants included Year 3 medical students at a private, midwestern medical school progressing through their surgery clerkship during the academic year 2009-2010. The medical school divides students into four groups; each group attends the surgery clerkship during one of the four quarters of the academic year. Students in the second and third quarters served as the modified-design group (n=91) and students in the fourth-quarter clerkship served as the traditional-design group (n=39). Both student cohorts had similar levels of pre-lecture knowledge. Both groups showed significant improvements in retention (p<0.0001), transfer (p<0.05) and total scores (p<0.0001) between the pre- and post-tests. Repeated-measures anova analysis showed statistically significant greater improvements in retention (F=10.2, p=0.0016) and total scores (F=7.13, p=0.0081) for those students instructed using principles of multimedia design compared with those instructed using the traditional design. Multimedia design principles are easy to implement and result in improved short-term retention among medical students, but empirical research is still needed to determine how these principles affect transfer of learning. Further research on applying the principles of multimedia

  16. The application of design principles to innovate clinical care delivery.

    PubMed

    Brennan, Michael D; Duncan, Alan K; Armbruster, Ryan R; Montori, Victor M; Feyereisn, Wayne L; LaRusso, Nicholas F

    2009-01-01

    Clinical research centers that support hypothesis-driven investigation have long been a feature of academic medical centers but facilities in which clinical care delivery can be systematically assessed and evaluated have heretofore been nonexistent. The Institute of Medicine report "Crossing the Quality Chasm" identified six core attributes of an ideal care delivery system that in turn relied heavily on system redesign. Although manufacturing and service industries have leveraged modern design principles in new product development, healthcare has lagged behind. In this article, we describe a methodology utilized by our facility to study the clinical care delivery system that incorporates modern design principles.

  17. Development of X-TOOLSS: Preliminary Design of Space Systems Using Evolutionary Computation

    NASA Technical Reports Server (NTRS)

    Schnell, Andrew R.; Hull, Patrick V.; Turner, Mike L.; Dozier, Gerry; Alverson, Lauren; Garrett, Aaron; Reneau, Jarred

    2008-01-01

    Evolutionary computational (EC) techniques such as genetic algorithms (GA) have been identified as promising methods to explore the design space of mechanical and electrical systems at the earliest stages of design. In this paper the authors summarize their research in the use of evolutionary computation to develop preliminary designs for various space systems. An evolutionary computational solver developed over the course of the research, X-TOOLSS (Exploration Toolset for the Optimization of Launch and Space Systems) is discussed. With the success of early, low-fidelity example problems, an outline of work involving more computationally complex models is discussed.

  18. Design principles and developmental mechanisms underlying retinal mosaics.

    PubMed

    Reese, Benjamin E; Keeley, Patrick W

    2015-08-01

    Most structures within the central nervous system (CNS) are composed of different types of neuron that vary in both number and morphology, but relatively little is known about the interplay between these two features, i.e. about the population dynamics of a given cell type. How such arrays of neurons are distributed within a structure, and how they differentiate their dendrites relative to each other, are issues that have recently drawn attention in the invertebrate nervous system, where the genetic and molecular underpinnings of these organizing principles are being revealed in exquisite detail. The retina is one of the few locations where these principles have been extensively studied in the vertebrate CNS, indeed, where the design principles of 'mosaic regularity' and 'uniformity of coverage' were first explicitly defined, quantified, and related to each other. Recent studies have revealed a number of genes that influence the formation of these histotypical features in the retina, including homologues of those invertebrate genes, although close inspection reveals that they do not always mediate comparable developmental processes nor elucidate fundamental design principles. The present review considers just how pervasive these features of 'mosaic regularity' and 'uniform dendritic coverage' are within the mammalian retina, discussing the means by which such features can be assessed in the mature and developing nervous system and examining the limitations associated with those assessments. We then address the extent to which these two design principles co-exist within different populations of neurons, and how they are achieved during development. Finally, we consider the neural phenotypes obtained in mutant nervous systems, to address whether a prospective gene of interest underlies those very design principles. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  19. Applying Minimalist Design Principles to the Problem of Computer Anxiety.

    ERIC Educational Resources Information Center

    Reznich, Christopher B.

    1996-01-01

    Minimalist design principles were used to test whether instructional intervention could decrease computer anxiety of subjects learning basic word-processing skills. Subjects were pre- and posttested on anxiety during each session. Findings indicated that the method as well as increased computer use decreased anxiety. (Author/AEF)

  20. Designing future landscapes from principles of form and function

    Treesearch

    Larry D. Harris; Patrick Kangas

    1979-01-01

    Future landscapes will consist of a gradient of types ranging from wilderness areas to totally "humanized" environments. The man-dominated landscapes will be required to fulfill multiple functions only one of which is aesthetic enjoyment. It is suggested that basic principles of form and function may contribute to design criteria. Applications to the...

  1. Design Principles for Computer-Aided Vocabulary Learning.

    ERIC Educational Resources Information Center

    Goodfellow, Robin

    1994-01-01

    Presents six principles for the design of adaptive computer-assisted language learning (CALL) programs for vocabulary that incorporate a theory describing quality in the learning outcome and linking it to the learner's approach. Highlights include interactivity; general architecture of a software system; and diagnosis and modification. (Contains…

  2. Visual Design Principles Applied To World Wide Web Construction.

    ERIC Educational Resources Information Center

    Luck, Donald D.; Hunter, J. Mark

    This paper describes basic types of World Wide Web pages and presents design criteria for page layout based on principles of visual literacy. Discussion focuses on pages that present information in the following styles: billboard; directory/index; textual; and graphics. Problems and solutions in Web page construction are explored according to…

  3. Design Principles for Cell Phone Learning in EFL

    ERIC Educational Resources Information Center

    Wang, Feihong

    2010-01-01

    Cell phone learning (C-learning), as an instructional approach, has been gaining more and more attention in the field of teaching English as a foreign language (EFL) in the last 10 years. While studies have proved C-learning an effective instructional approach in research settings, a review of literature indicates the lack of design principles to…

  4. Elements and Principles of Design Posters. Teacher's Guide.

    ERIC Educational Resources Information Center

    1996

    This book accompanies a poster series and allows the teacher to pre-plan a lesson or activity for students with the objectives shown for each element or principle of design to be presented. Along with a black-and-white reproduction of each poster, major concepts are discussed. Suggested student activities relating to a particular element or…

  5. Adult Learning Principles in Designing Learning Activities for Teacher Development

    ERIC Educational Resources Information Center

    Gravani, Maria N.

    2012-01-01

    The research reported in this paper is an investigation of the application of adult learning principles in designing learning activities for teachers' life-long development. The exploration is illustrated by qualitative data from a case study of adult educators' and adult learners' insights and experiences of a teacher development course organised…

  6. CASTE Revisited: Principles of Course Design in a Hypertext Environment.

    ERIC Educational Resources Information Center

    Scott, Bernard

    2000-01-01

    Describes CASTE (Course Assembly System and Tutorial Environment) that was developed to help students choose appropriate learning strategies in a hypertext environment. Highlights include the need for principles of course design; resource-based learning and computer-aided learning; conversation theory; and a comparison to other approaches.…

  7. Web Interface Design Principles for Adults' Self-Directed Learning

    ERIC Educational Resources Information Center

    Firat, Mehmet; Sakar, A. Nurhan; Kabakci Yurdakul, Isil

    2016-01-01

    One of the most important features which e-learning tools and environments must possess within the scope of lifelong learning is self-directed learning, which can be considered as a form of self-learning. The aim of this study was to determine, based on the views and recommendations of experts, interface design principles for the development of…

  8. Virtual Worlds; Real Learning: Design Principles for Engaging Immersive Environments

    NASA Technical Reports Server (NTRS)

    Wu (u. Sjarpm)

    2012-01-01

    The EMDT master's program at Full Sail University embarked on a small project to use a virtual environment to teach graduate students. The property used for this project has evolved our several iterations and has yielded some basic design principles and pedagogy for virtual spaces. As a result, students are emerging from the program with a better grasp of future possibilities.

  9. Some Novel Design Principles for Collective Behaviors in Mobile Robots

    SciTech Connect

    OSBOURN, GORDON C.

    2002-09-01

    We present a set of novel design principles to aid in the development of complex collective behaviors in fleets of mobile robots. The key elements are: the use of a graph algorithm that we have created, with certain proven properties, that guarantee scalable local communications for fleets of arbitrary size; the use of artificial forces to simplify the design of motion control; the use of certain proximity values in the graph algorithm to simplify the sharing of robust navigation and sensor information among the robots. We describe these design elements and present a computer simulation that illustrates the behaviors readily achievable with these design tools.

  10. DeafSpace and the principles of universal design.

    PubMed

    Edwards, Claire; Harold, Gill

    2014-01-01

    Recent debates about the epistemological origins of Universal Design (UD) have questioned how far universalist design approaches can address the particularities and diversities of the human form through a series of standardised, technical responses. This article contributes to these debates by discussing an emergent architectural paradigm known as DeafSpace, which articulates a set of design principles originating from the d/Deaf community in the US. Commentary. DeafSpace has emerged as a design paradigm rooted in an expression of d/Deaf cultural identity based around sign language, rather than as a response designed to compensate for, or minimise, impairment. It distinguishes itself from UD by articulating a more user-centred design process, but its principles are arguably rooted in notions of d/Deaf identity based around consensus and homogeneity, with less attention paid to the socio-political contexts which shape diverse experiences of d/Deafness and the exclusion(s) of d/Deaf people from the built environment. While proponents of DeafSpace argue that UD and DeafSpace are not mutually exclusive, nor DeafSpace principles applicable only to d/Deaf people, questions remain about the type of spaces DeafSpace creates, most notably whether they lead to the creation of particularist spaces of and for the d/Deaf community, or reflect a set of design principles which can be embedded across a range of different environments. Implications for Rehabilitation UD as a basis for rehabilitation has been critiqued on the basis that creates "standardised", or universal solutions, thus negating the particularities of the human form. DeafSpace is an architectural paradigm rooted in socio-linguistic understandings of Deafness and the cultural identity of the Deaf community. It challenges UD's technocratic emphasis on minimising impairment and asserts design which is rooted in a more qualitative understanding of individuals' relationship with their environment. DeafSpace seeks to

  11. ENPDA: an evolutionary structure-based de novo peptide design algorithm

    NASA Astrophysics Data System (ADS)

    Belda, Ignasi; Madurga, Sergio; Llorà, Xavier; Martinell, Marc; Tarragó, Teresa; Piqueras, Mireia G.; Nicolás, Ernesto; Giralt, Ernest

    2005-08-01

    One of the goals of computational chemists is to automate the de novo design of bioactive molecules. Despite significant advances in computational approaches to ligand design and binding energy evaluation, novel procedures for ligand design are required. Evolutionary computation provides a new approach to this design endeavor. We propose an evolutionary tool for de novo peptide design, based on the evaluation of energies for peptide binding to a user-defined protein surface patch. Special emphasis has been placed on the evaluation of the proposed peptides, leading to two different evaluation heuristics. The software developed was successfully tested on the design of ligands for the proteins prolyl oligopeptidase, p53, and DNA gyrase.

  12. Bionics, biological systems and the principle of optimal design.

    PubMed

    Popescu, A I

    The living world is an exciting and inexhaustible source of high performance solutions to the multitude of biological problems, which were attained as a result of a natural selection, during the millions and millions years evolution of life on Earth. This work presents and comments some examples of high performances of living beings, in the light of the universal principle governing the realm of living matter: Optimal Design Principle. At the same time, the transfer of these optimal solutions, from living matter to the technologies, is also discussed. This transfer is offering new and fertile perspectives to future technologies, which must be more efficient, cheaper and in perfect harmony with the biosphere.

  13. Elastohydrodynamic principles applied to the design of helicopter components

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1973-01-01

    Elastohydrodynamic principles affecting the lubrication of transmission components are presented and discussed. Surface temperature of the transmission bearings and gears affect elastohydrodynamic film thickness. Traction forces and sliding as well as the inlet temperature determine surface temperatures. High contact ratio gears cause increased sliding and may run at higher surface temperatures. Component life is a function of the ratio of elastohydrodynamic film thickness to composite surface roughness. Lubricant starvation reduces elastrohydrodynamic film thickness and increases surface temperatures. Methods are presented which allow for the application of elastohydrodynamic principles to transmission design in order to increase system life and reliability.

  14. Design Principles for Effective Knowledge Discovery from Big Data

    SciTech Connect

    Begoli, Edmon; Horey, James L

    2012-01-01

    Big data phenomenon refers to the practice of collection and processing of very large data sets and associated systems and algorithms used to analyze these massive datasets. Architectures for big data usually range across multiple machines and clusters, and they commonly consist of multiple special purpose sub-systems. Coupled with the knowledge discovery process, big data movement offers many unique opportunities for organizations to benefit (with respect to new insights, business optimizations, etc.). However, due to the difficulty of analyzing such large datasets, big data presents unique systems engineering and architectural challenges. In this paper, we present three sys- tem design principles that can inform organizations on effective analytic and data collection processes, system organization, and data dissemination practices. The principles presented derive from our own research and development experiences with big data problems from various federal agencies, and we illustrate each principle with our own experiences and recommendations.

  15. Babinet principle applied to the design of metasurfaces and metamaterials.

    PubMed

    Falcone, F; Lopetegi, T; Laso, M A G; Baena, J D; Bonache, J; Beruete, M; Marqués, R; Martín, F; Sorolla, M

    2004-11-05

    The electromagnetic theory of diffraction and the Babinet principle are applied to the design of artificial metasurfaces and metamaterials. A new particle, the complementary split rings resonator, is proposed for the design of metasurfaces with high frequency selectivity and planar metamaterials with a negative dielectric permittivity. Applications in the fields of frequency selective surfaces and polarizers, as well as in microwave antennas and filter design, can be envisaged. The tunability of all these devices by an applied dc voltage is also achievable if these particles are etched on the appropriate substrate.

  16. Design principles for achieving integrated healthcare information systems.

    PubMed

    Jensen, Tina Blegind

    2013-03-01

    Achieving integrated healthcare information systems has become a common goal for many countries in their pursuit of obtaining coordinated and comprehensive healthcare services. This article focuses on how a small local project termed 'Standardized pull of patient data' expanded and is now used on a large scale providing a majority of hospitals, general practitioners and citizens across Denmark with the possibility of accessing healthcare data from different electronic patient record systems and other systems. I build on design theory for information infrastructures, as presented by Hanseth and Lyytinen, to examine the design principles that facilitated this smallscale project to expand and become widespread. As a result of my findings, I outline three lessons learned that emphasize: (i) principles of flexibility, (ii) expansion from the installed base through modular strategies and (iii) identification of key healthcare actors to provide them with immediate benefits.

  17. Graphic design principles for automated document segmentation and understanding

    NASA Astrophysics Data System (ADS)

    Vega-Riveros, J. Fernando; Santos Villalobos, Hector J.

    2006-01-01

    When designers develop a document layout their objective is to convey a specific message and provoke a specific response from the audience. Design principles provide the foundation for identifying document components and relations among them to extract implicit knowledge from the layout. Variable Data Printing enables the production of personalized printing jobs for which traditional proofing of all the job instances could result unfeasible. This paper explains a rule-based system that uses design principles to segment and understand document context. The system uses the design principles of repetition, proximity, alignment, similarity, and contrast as the foundation for the strategy in document segmentation and understanding which holds a strong relation with the recognition of artifacts produced by the infringement of the constraints articulated in the document layout. There are two main modules in the tool: the geometric analysis module; and the design rule engine. The geometric analysis module extracts explicit knowledge from the data provided in the document. The design rule module uses the information provided by the geometric analysis to establish logical units inside the document. We used a subset of XSL-FO, sufficient for designing documents with an adequate amount complexity. The system identifies components such as headers, paragraphs, lists, images and determines the relations between them, such as header-paragraph, header-list, etc. The system provides accurate information about the geometric properties of the components, detects the elements of the documents and identifies corresponding components between a proofed instance and the rest of the instances in a Variable Data Printing Job.

  18. Design principles of a rotating medium speed mechanism

    NASA Technical Reports Server (NTRS)

    Hostenkamp, R. G.; Achtermann, E.; Bentall, R. H.

    1976-01-01

    Design principles of a medium speed mechanism (MSM) are presented, including discussion on the relative merits of beryllium and aluminium as structural materials. Rotating at a speed of 60 rpm, the application envisaged for the MSM was as a despin bearing for the despun platform or despun antenna of a spin stabilized satellite. The MSM was built and tested to qualification level and is currently undergoing real time life testing.

  19. Natural product inspired compound collections: evolutionary principle, chemical synthesis, phenotypic screening, and target identification.

    PubMed

    Laraia, Luca; Waldmann, Herbert

    2017-03-01

    Natural products have been an excellent and abundant source of therapeutics for many decades. To expand on their success, and explore areas of chemical space not covered by biosynthesis, the synthesis of natural product-inspired compound collections has emerged as a viable strategy. Herein we describe the principles behind biology-oriented synthesis and related approaches, the requirements for development of novel chemistry and how phenotypic screens are a very fruitful way to explore the bioactivity of compounds made using these approaches. Finally, we summarize state-of-the-art techniques to identify the biological targets of any hits identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Application of an evolutionary algorithm in the optimal design of micro-sensor.

    PubMed

    Lu, Qibing; Wang, Pan; Guo, Sihai; Sheng, Buyun; Liu, Xingxing; Fan, Zhun

    2015-01-01

    This paper introduces an automatic bond graph design method based on genetic programming for the evolutionary design of micro-resonator. First, the system-level behavioral model is discussed, which based on genetic programming and bond graph. Then, the geometry parameters of components are automatically optimized, by using the genetic algorithm with constraints. To illustrate this approach, a typical device micro-resonator is designed as an example in biomedicine. This paper provides a new idea for the automatic optimization design of biomedical sensors by evolutionary calculation.

  1. How mutualisms arise in phytoplankton communities: building eco-evolutionary principles for aquatic microbes.

    PubMed

    Kazamia, Elena; Helliwell, Katherine Emma; Purton, Saul; Smith, Alison Gail

    2016-07-01

    Extensive sampling and metagenomics analyses of plankton communities across all aquatic environments are beginning to provide insights into the ecology of microbial communities. In particular, the importance of metabolic exchanges that provide a foundation for ecological interactions between microorganisms has emerged as a key factor in forging such communities. Here we show how both studies of environmental samples and physiological experimentation in the laboratory with defined microbial co-cultures are being used to decipher the metabolic and molecular underpinnings of such exchanges. In addition, we explain how metabolic modelling may be used to conduct investigations in reverse, deducing novel molecular exchanges from analysis of large-scale data sets, which can identify persistently co-occurring species. Finally, we consider how knowledge of microbial community ecology can be built into evolutionary theories tailored to these species' unique lifestyles. We propose a novel model for the evolution of metabolic auxotrophy in microorganisms that arises as a result of symbiosis, termed the Foraging-to-Farming hypothesis. The model has testable predictions, fits several known examples of mutualism in the aquatic world, and sheds light on how interactions, which cement dependencies within communities of microorganisms, might be initiated.

  2. Design Principles for Nickel/Hydrogen Cells and Batteries

    NASA Technical Reports Server (NTRS)

    Thaller, Lawrence H.; Manzo, Michelle A.; Gonzalez-Sanabria, Olga D.

    1987-01-01

    Individual-pressure-vessel (IPV) nickel/hydrogen cells and bipolar batteries developed for use as energy-storage subsystems for satelite applications. Design principles applied draw upon extensive background in separator technology, alkaline-fuel-cell technology and several alkaline-cell technology areas. Principals are rather straightforward applications of capillary-force formalisms, coupled with slowly developing data base resulting from careful post-test analyses. Based on preconceived assumptions relative to how devices work and how to be designed so they display longer cycle lives at deep discharge.

  3. Ergonomics and design: its principles applied in the industry.

    PubMed

    Tavares, Ademario Santos; Silva, Francisco Nilson da

    2012-01-01

    Industrial Design encompasses both product development and optimization of production process. In this sense, Ergonomics plays a fundamental role, because its principles, methods and techniques can help operators to carry out their tasks most successfully. A case study carried out in an industry shows that the interaction among Design, Production Engineering and Materials Engineering departments may improve some aspects concerned security, comfort, efficiency and performance. In this process, Ergonomics had shown to be of essential importance to strategic decision making to the improvement of production section.

  4. Design Principles for Nickel/Hydrogen Cells and Batteries

    NASA Technical Reports Server (NTRS)

    Thaller, Lawrence H.; Manzo, Michelle A.; Gonzalez-Sanabria, Olga D.

    1987-01-01

    Individual-pressure-vessel (IPV) nickel/hydrogen cells and bipolar batteries developed for use as energy-storage subsystems for satelite applications. Design principles applied draw upon extensive background in separator technology, alkaline-fuel-cell technology and several alkaline-cell technology areas. Principals are rather straightforward applications of capillary-force formalisms, coupled with slowly developing data base resulting from careful post-test analyses. Based on preconceived assumptions relative to how devices work and how to be designed so they display longer cycle lives at deep discharge.

  5. The structural analysis of shark IgNAR antibodies reveals evolutionary principles of immunoglobulins

    PubMed Central

    Feige, Matthias J.; Gräwert, Melissa A.; Marcinowski, Moritz; Hennig, Janosch; Behnke, Julia; Ausländer, David; Herold, Eva M.; Peschek, Jirka; Castro, Caitlin D.; Flajnik, Martin; Hendershot, Linda M.; Sattler, Michael; Groll, Michael; Buchner, Johannes

    2014-01-01

    Sharks and other cartilaginous fish are the phylogenetically oldest living organisms that rely on antibodies as part of their adaptive immune system. They produce the immunoglobulin new antigen receptor (IgNAR), a homodimeric heavy chain-only antibody, as a major part of their humoral adaptive immune response. Here, we report the atomic resolution structure of the IgNAR constant domains and a structural model of this heavy chain-only antibody. We find that despite low sequence conservation, the basic Ig fold of modern antibodies is already present in the evolutionary ancient shark IgNAR domains, highlighting key structural determinants of the ubiquitous Ig fold. In contrast, structural differences between human and shark antibody domains explain the high stability of several IgNAR domains and allowed us to engineer human antibodies for increased stability and secretion efficiency. We identified two constant domains, C1 and C3, that act as dimerization modules within IgNAR. Together with the individual domain structures and small-angle X-ray scattering, this allowed us to develop a structural model of the complete IgNAR molecule. Its constant region exhibits an elongated shape with flexibility and a characteristic kink in the middle. Despite the lack of a canonical hinge region, the variable domains are spaced appropriately wide for binding to multiple antigens. Thus, the shark IgNAR domains already display the well-known Ig fold, but apart from that, this heavy chain-only antibody employs unique ways for dimerization and positioning of functional modules. PMID:24830426

  6. The structural analysis of shark IgNAR antibodies reveals evolutionary principles of immunoglobulins.

    PubMed

    Feige, Matthias J; Gräwert, Melissa A; Marcinowski, Moritz; Hennig, Janosch; Behnke, Julia; Ausländer, David; Herold, Eva M; Peschek, Jirka; Castro, Caitlin D; Flajnik, Martin; Hendershot, Linda M; Sattler, Michael; Groll, Michael; Buchner, Johannes

    2014-06-03

    Sharks and other cartilaginous fish are the phylogenetically oldest living organisms that rely on antibodies as part of their adaptive immune system. They produce the immunoglobulin new antigen receptor (IgNAR), a homodimeric heavy chain-only antibody, as a major part of their humoral adaptive immune response. Here, we report the atomic resolution structure of the IgNAR constant domains and a structural model of this heavy chain-only antibody. We find that despite low sequence conservation, the basic Ig fold of modern antibodies is already present in the evolutionary ancient shark IgNAR domains, highlighting key structural determinants of the ubiquitous Ig fold. In contrast, structural differences between human and shark antibody domains explain the high stability of several IgNAR domains and allowed us to engineer human antibodies for increased stability and secretion efficiency. We identified two constant domains, C1 and C3, that act as dimerization modules within IgNAR. Together with the individual domain structures and small-angle X-ray scattering, this allowed us to develop a structural model of the complete IgNAR molecule. Its constant region exhibits an elongated shape with flexibility and a characteristic kink in the middle. Despite the lack of a canonical hinge region, the variable domains are spaced appropriately wide for binding to multiple antigens. Thus, the shark IgNAR domains already display the well-known Ig fold, but apart from that, this heavy chain-only antibody employs unique ways for dimerization and positioning of functional modules.

  7. Semiconductor-inspired design principles for superconducting quantum computing

    NASA Astrophysics Data System (ADS)

    Shim, Yun-Pil; Tahan, Charles

    2016-03-01

    Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit-based quantum computing. Here we begin to explore how selective design principles deduced from spin-based systems could be used to advance superconducting qubit science. We take an initial step along this path proposing an encoded qubit approach realizable with state-of-the-art tunable Josephson junction qubits. Our results show that this design philosophy holds promise, enables microwave-free control, and offers a pathway to future qubit designs with new capabilities such as with higher fidelity or, perhaps, operation at higher temperature. The approach is also especially suited to qubits on the basis of variable super-semi junctions.

  8. Semiconductor-inspired design principles for superconducting quantum computing.

    PubMed

    Shim, Yun-Pil; Tahan, Charles

    2016-03-17

    Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit-based quantum computing. Here we begin to explore how selective design principles deduced from spin-based systems could be used to advance superconducting qubit science. We take an initial step along this path proposing an encoded qubit approach realizable with state-of-the-art tunable Josephson junction qubits. Our results show that this design philosophy holds promise, enables microwave-free control, and offers a pathway to future qubit designs with new capabilities such as with higher fidelity or, perhaps, operation at higher temperature. The approach is also especially suited to qubits on the basis of variable super-semi junctions.

  9. Principles of nanostructure design with protein building blocks.

    PubMed

    Tsai, Chung-Jung; Zheng, Jie; Zanuy, David; Haspel, Nurit; Wolfson, Haim; Alemán, Carlos; Nussinov, Ruth

    2007-07-01

    Currently there is increasing interest in nanostructures and their design. Nanostructure design involves the ability to predictably manipulate the properties of the self-assembly of autonomous units. Autonomous units have preferred conformational states. The units can be synthetic material science-based or derived from functional biological macromolecules. Autonomous biological building blocks with available structures provide an extremely rich and useful resource for design. For proteins, the structural databases contain large libraries of protein molecules and their building blocks with a range of shapes, surfaces, and chemical properties. The introduction of engineered synthetic residues or short peptides into these can expand the available chemical space and enhance the desired properties. Here we focus on the principles of nanostructure design with protein building blocks.

  10. Design principles for rapid folding of knotted DNA nanostructures.

    PubMed

    Kočar, Vid; Schreck, John S; Čeru, Slavko; Gradišar, Helena; Bašić, Nino; Pisanski, Tomaž; Doye, Jonathan P K; Jerala, Roman

    2016-02-18

    Knots are some of the most remarkable topological features in nature. Self-assembly of knotted polymers without breaking or forming covalent bonds is challenging, as the chain needs to be threaded through previously formed loops in an exactly defined order. Here we describe principles to guide the folding of highly knotted single-chain DNA nanostructures as demonstrated on a nano-sized square pyramid. Folding of knots is encoded by the arrangement of modules of different stability based on derived topological and kinetic rules. Among DNA designs composed of the same modules and encoding the same topology, only the one with the folding pathway designed according to the 'free-end' rule folds efficiently into the target structure. Besides high folding yield on slow annealing, this design also folds rapidly on temperature quenching and dilution from chemical denaturant. This strategy could be used to design folding of other knotted programmable polymers such as RNA or proteins.

  11. Semiconductor-inspired design principles for superconducting quantum computing

    PubMed Central

    Shim, Yun-Pil; Tahan, Charles

    2016-01-01

    Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit-based quantum computing. Here we begin to explore how selective design principles deduced from spin-based systems could be used to advance superconducting qubit science. We take an initial step along this path proposing an encoded qubit approach realizable with state-of-the-art tunable Josephson junction qubits. Our results show that this design philosophy holds promise, enables microwave-free control, and offers a pathway to future qubit designs with new capabilities such as with higher fidelity or, perhaps, operation at higher temperature. The approach is also especially suited to qubits on the basis of variable super-semi junctions. PMID:26983379

  12. Toward instructional design principles: Inducing Faraday's law with contrasting cases

    NASA Astrophysics Data System (ADS)

    Kuo, Eric; Wieman, Carl E.

    2016-06-01

    Although physics education research (PER) has improved instructional practices, there are not agreed upon principles for designing effective instructional materials. Here, we illustrate how close comparison of instructional materials could support the development of such principles. Specifically, in discussion sections of a large, introductory physics course, a pair of studies compare two instructional strategies for teaching a physics concept: having students (i) explain a set of contrasting cases or (ii) apply and build on previously learned concepts. We compare these strategies for the teaching of Faraday's law, showing that explaining a set of related contrasting cases not only improves student performance on Faraday's law questions over building on a previously learned concept (i.e., Lorentz force), but also prepares students to better learn subsequent topics, such as Lenz's law. These differences persist to the final exam. We argue that early exposure to contrasting cases better focuses student attention on a key feature related to both concepts: change in magnetic flux. Importantly, the benefits of contrasting cases for both learning and enjoyment are enhanced for students who did not first attend a Faraday's law lecture, consistent with previous research suggesting that being told a solution can circumvent the benefits of its discovery. These studies illustrate an experimental approach for understanding how the structure of activities affects learning and performance outcomes, a first step toward design principles for effective instructional materials.

  13. Designing the Electronic Classroom: Applying Learning Theory and Ergonomic Design Principles.

    ERIC Educational Resources Information Center

    Emmons, Mark; Wilkinson, Frances C.

    2001-01-01

    Applies learning theory and ergonomic principles to the design of effective learning environments for library instruction. Discusses features of electronic classroom ergonomics, including the ergonomics of physical space, environmental factors, and workstations; and includes classroom layouts. (Author/LRW)

  14. Designing the Electronic Classroom: Applying Learning Theory and Ergonomic Design Principles.

    ERIC Educational Resources Information Center

    Emmons, Mark; Wilkinson, Frances C.

    2001-01-01

    Applies learning theory and ergonomic principles to the design of effective learning environments for library instruction. Discusses features of electronic classroom ergonomics, including the ergonomics of physical space, environmental factors, and workstations; and includes classroom layouts. (Author/LRW)

  15. Principle of bio-inspired insect wing rotational hinge design

    NASA Astrophysics Data System (ADS)

    Fei, Fan

    A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is shown to be applicable to a wide range of wing designs with different sizes and shapes. With the selected hinge stiffness value, aspects of the rotational joint design is discussed and an integrated wing-hinge structure design using laminated carbon fiber and polymer film is presented. Manufacturing process of such composite structure is developed to achieve high accuracy and repeatability. The yielded hinge stiffness is verified by measurements. To validate the proposed model, flapping wing experiments were conducted. A flapping actuation set up is built using DC motor and a controller is implemented on a microcontroller to track desired wing stroke kinematic. Wing stroke and rotation kinematic were extracted using a high speed camera and the lift generation is evaluated. A total of 49 flapping experiments were presented, experimental data shows good correlation with the model's prediction. With the wing rotational hinge stiffness designed so that the rotational resonant frequency is twice as the stroke frequency, the resulting wing rotation generates near optimal lift. With further simulation, the proposed model shows low sensitivity to wing parameter variation. As a result, giving a design parameter of a flapping wing robot platform, the proposed principle can

  16. Teaching for understanding in medical classrooms using multimedia design principles.

    PubMed

    Issa, Nabil; Mayer, Richard E; Schuller, Mary; Wang, Edward; Shapiro, Michael B; DaRosa, Debra A

    2013-04-01

    In line with a recent report entitled Effective Use of Educational Technology in Medical Education from the Association of American Medical Colleges Institute for Improving Medical Education (AAMC-IME), this study examined whether revising a medical lecture based on evidence-based principles of multimedia design would lead to improved long-term transfer and retention in Year 3 medical students. A previous study yielded positive effects on an immediate retention test, but did not investigate long-term effects. In a pre-test/post-test control design, a cohort of 37 Year 3 medical students at a private, midwestern medical school received a bullet point-based PowerPoint™ lecture on shock developed by the instructor as part of their core curriculum (the traditional condition group). Another cohort of 43 similar medical students received a lecture covering identical content using slides redesigned according to Mayer's evidence-based principles of multimedia design (the modified condition group). Findings showed that the modified condition group significantly outscored the traditional condition group on delayed tests of transfer given 1 week (d = 0.83) and 4 weeks (d = 1.17) after instruction, and on delayed tests of retention given 1 week (d = 0.83) and 4 weeks (d = 0.79) after instruction. The modified condition group also significantly outperformed the traditional condition group on immediate tests of retention (d = 1.49) and transfer (d = 0.76). This study provides the first evidence that applying multimedia design principles to an actual medical lecture has significant effects on measures of learner understanding (i.e. long-term transfer and long-term retention). This work reinforces the need to apply the science of learning and instruction in medical education. © Blackwell Publishing Ltd 2013.

  17. Playfulness-Based Design in Educational Games: A Perspective on an Evolutionary Contest Game

    ERIC Educational Resources Information Center

    Hong, Jon-Chao; Hwang, Ming-Yueh; Lu, Chin-Hsieh; Cheng, Ching-Ling; Lee, Yu-Chen; Lin, Chan-Li

    2009-01-01

    Playfulness steering is an emerging approach in educational game design and play. The integration of arithmetical computation, game strategy, and teamwork into one game allows players to interactively "steer" the playfulness and enhance learning. In this paper an evolutionary contest game was designed and implemented to examine the…

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

    SciTech Connect

    Bieniawski, Z.T.

    1996-04-01

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

  19. An Exploratory Review of Design Principles in Constructivist Gaming Learning Environments

    ERIC Educational Resources Information Center

    Rosario, Roberto A. Munoz; Widmeyer, George R.

    2009-01-01

    Creating a design theory for Constructivist Gaming Learning Environment necessitates, among other things, the establishment of design principles. These principles have the potential to help designers produce games, where users achieve higher levels of learning. This paper focuses on twelve design principles: Probing, Distributed, Multiple Routes,…

  20. An Exploratory Review of Design Principles in Constructivist Gaming Learning Environments

    ERIC Educational Resources Information Center

    Rosario, Roberto A. Munoz; Widmeyer, George R.

    2009-01-01

    Creating a design theory for Constructivist Gaming Learning Environment necessitates, among other things, the establishment of design principles. These principles have the potential to help designers produce games, where users achieve higher levels of learning. This paper focuses on twelve design principles: Probing, Distributed, Multiple Routes,…

  1. Proof of principle for epitope-focused vaccine design

    PubMed Central

    Correia, Bruno E.; Bates, John T.; Loomis, Rebecca J.; Baneyx, Gretchen; Carrico, Christopher; Jardine, Joseph G.; Rupert, Peter; Correnti, Colin; Kalyuzhniy, Oleksandr; Vittal, Vinayak; Connell, Mary J.; Stevens, Eric; Schroeter, Alexandria; Chen, Man; MacPherson, Skye; Serra, Andreia M.; Adachi, Yumiko; Holmes, Margaret A.; Li, Yuxing; Klevit, Rachel E.; Graham, Barney S.; Wyatt, Richard T.; Baker, David; Strong, Roland K.; Crowe, James E.; Johnson, Philip R.; Schief, William R.

    2014-01-01

    Summary Vaccines prevent infectious disease largely by inducing protective neutralizing antibodies against vulnerable epitopes. Multiple major pathogens have resisted traditional vaccine development, although vulnerable epitopes targeted by neutralizing antibodies have been identified for several such cases. Hence, new vaccine design methods to induce epitope-specific neutralizing antibodies are needed. Here we show, with a neutralization epitope from respiratory syncytial virus (RSV), that computational protein design can generate small, thermally and conformationally stable protein scaffolds that accurately mimic the viral epitope structure and induce potent neutralizing antibodies. These scaffolds represent promising leads for research and development of a human RSV vaccine needed to protect infants, young children and the elderly. More generally, the results provide proof of principle for epitope-focused and scaffold-based vaccine design, and encourage the evaluation and further development of these strategies for a variety of other vaccine targets including antigenically highly variable pathogens such as HIV and influenza. PMID:24499818

  2. Proof of principle for epitope-focused vaccine design

    NASA Astrophysics Data System (ADS)

    Correia, Bruno E.; Bates, John T.; Loomis, Rebecca J.; Baneyx, Gretchen; Carrico, Chris; Jardine, Joseph G.; Rupert, Peter; Correnti, Colin; Kalyuzhniy, Oleksandr; Vittal, Vinayak; Connell, Mary J.; Stevens, Eric; Schroeter, Alexandria; Chen, Man; MacPherson, Skye; Serra, Andreia M.; Adachi, Yumiko; Holmes, Margaret A.; Li, Yuxing; Klevit, Rachel E.; Graham, Barney S.; Wyatt, Richard T.; Baker, David; Strong, Roland K.; Crowe, James E.; Johnson, Philip R.; Schief, William R.

    2014-03-01

    Vaccines prevent infectious disease largely by inducing protective neutralizing antibodies against vulnerable epitopes. Several major pathogens have resisted traditional vaccine development, although vulnerable epitopes targeted by neutralizing antibodies have been identified for several such cases. Hence, new vaccine design methods to induce epitope-specific neutralizing antibodies are needed. Here we show, with a neutralization epitope from respiratory syncytial virus, that computational protein design can generate small, thermally and conformationally stable protein scaffolds that accurately mimic the viral epitope structure and induce potent neutralizing antibodies. These scaffolds represent promising leads for the research and development of a human respiratory syncytial virus vaccine needed to protect infants, young children and the elderly. More generally, the results provide proof of principle for epitope-focused and scaffold-based vaccine design, and encourage the evaluation and further development of these strategies for a variety of other vaccine targets, including antigenically highly variable pathogens such as human immunodeficiency virus and influenza.

  3. Spatial design principles for sustainable hydropower development in river basins

    DOE PAGES

    Jager, Henriëtte I.; Efroymson, Rebecca A.; Opperman, Jeff J.; ...

    2015-02-27

    How can dams be arranged within a river basin such that they benefit society? Recent interest in this question has grown in response to the worldwide trend toward developing hydropower as a source of renewable energy in Asia and South America, and the movement toward removing unnecessary dams in the US. Environmental and energy sustainability are important practical concerns, and yet river development has rarely been planned with the goal of providing society with a portfolio of ecosystem services into the future. We organized a review and synthesis of the growing research in sustainable river basin design around four spatialmore » decisions: Is it better to build fewer mainstem dams or more tributary dams? Should dams be clustered or distributed among distant subbasins? Where should dams be placed along a river? At what spatial scale should decisions be made? We came up with the following design principles for increasing ecological sustainability: (i) concentrate dams within a subset of tributary watersheds and avoid downstream mainstems of rivers, (ii) disperse freshwater reserves among the remaining tributary catchments, (iii) ensure that habitat provided between dams will support reproduction and retain offspring, and (iv) formulate spatial decision problems at the scale of large river basins. Based on our review, we discuss trade-offs between hydropower and ecological objectives when planning river basin development. We hope that future testing and refinement of principles extracted from our review will define a path toward sustainable river basin design.« less

  4. Spatial design principles for sustainable hydropower development in river basins

    SciTech Connect

    Jager, Henriëtte I.; Efroymson, Rebecca A.; Opperman, Jeff J.; Kelly, Michael R.

    2015-02-27

    How can dams be arranged within a river basin such that they benefit society? Recent interest in this question has grown in response to the worldwide trend toward developing hydropower as a source of renewable energy in Asia and South America, and the movement toward removing unnecessary dams in the US. Environmental and energy sustainability are important practical concerns, and yet river development has rarely been planned with the goal of providing society with a portfolio of ecosystem services into the future. We organized a review and synthesis of the growing research in sustainable river basin design around four spatial decisions: Is it better to build fewer mainstem dams or more tributary dams? Should dams be clustered or distributed among distant subbasins? Where should dams be placed along a river? At what spatial scale should decisions be made? We came up with the following design principles for increasing ecological sustainability: (i) concentrate dams within a subset of tributary watersheds and avoid downstream mainstems of rivers, (ii) disperse freshwater reserves among the remaining tributary catchments, (iii) ensure that habitat provided between dams will support reproduction and retain offspring, and (iv) formulate spatial decision problems at the scale of large river basins. Based on our review, we discuss trade-offs between hydropower and ecological objectives when planning river basin development. We hope that future testing and refinement of principles extracted from our review will define a path toward sustainable river basin design.

  5. Using Green Chemistry and Engineering Principles to Design ...

    EPA Pesticide Factsheets

    The concepts of green chemistry and engineering (GC&E) have been promoted as an effective qualitative framework for developing more sustainable chemical syntheses, processes, and material management techniques. This has been demonstrated by many theoretical and practical cases. In addition, there are several approaches and frameworks focused on demonstrating that improvements were achieved through GC&E technologies. However, the application of these principles is not always straightforward. We propose using systematic frameworks and tools that help practitioners when deciding which principles can be applied, the levels of implementation, prospective of obtaining simultaneous improvements in all sustainability aspects, and ways to deal with multiobjective problems. Therefore, this contribution aims to provide a systematic combination of three different and complementary design tools for assisting designers in evaluating, developing, and improving chemical manufacturing and material management systems under GC&E perspectives. The WAR Algorithm, GREENSCOPE, and SustainPro were employed for this synergistic approach of incorporating sustainability at early stages of process development. In this demonstration, simulated ammonia production is used as a case study to illustrate this advancement. Results show how to identify process design areas for improvements, key factors, multi-criteria decision-making solutions, and optimal tradeoffs. Finally, conclusions were pre

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

    NASA Astrophysics Data System (ADS)

    Taylor, Robert Michael

    2000-10-01

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

  7. Coherent electron cooling proof of principle instrumentation design

    SciTech Connect

    Gassner D. M.; Litvinenko, V.; Michnoff, R.; Miller, T.; Minty, M.; Pinayev, I.

    2012-04-15

    The goal of the Coherent Electron Cooling Proof-of-Principle (CeC PoP) experiment being designed at RHIC is to demonstrate longitudinal (energy spread) cooling before the expected CD-2 for eRHIC. The scope of the experiment is to longitudinally cool a single bunch of 40 GeV/u gold ions in RHIC. This paper will describe the instrumentation systems proposed to meet the diagnostics challenges. These include measurements of beam intensity, emittance, energy spread, bunch length, position, orbit stability, and transverse and temporal alignment of electron and ion beams.

  8. Design principles and algorithms for automated air traffic management

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    1995-01-01

    This paper presents design principles and algorithm for building a real time scheduler. The primary objective of the scheduler is to assign arrival aircraft to a favorable landing runway and schedule them to land at times that minimize delays. A further objective of the scheduler is to allocate delays between high altitude airspace far from the airport and low altitude airspace near the airport. A method of delay allocation is described that minimizes the average operating cost in the presence of errors in controlling aircraft to a specified landing time.

  9. Design principles for noninvasive brain-machine interfaces.

    PubMed

    Contreras-Vidal, José L; Bradberry, Trent J

    2011-01-01

    With the advent of sophisticated prosthetic limbs, the challenge is now to develop and demonstrate optimal closed-loop control of the these limbs using neural measurements from single/multiple unit activity (SUA/MUA), electrocorticography (ECoG), local field potentials (LFP), scalp electroencephalography (EEG) or even electromyography (EMG) after targeted muscle reinnervation (TMR) in subjects with upper limb disarticulation. In this paper we propose design principles for developing a noninvasive EEG-based brain-machine interface (BMI) for dexterous control of a high degree-of-freedom, biologically realistic limb.

  10. Design principles and algorithms for automated air traffic management

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    1995-01-01

    This paper presents design principles and algorithm for building a real time scheduler. The primary objective of the scheduler is to assign arrival aircraft to a favorable landing runway and schedule them to land at times that minimize delays. A further objective of the scheduler is to allocate delays between high altitude airspace far from the airport and low altitude airspace near the airport. A method of delay allocation is described that minimizes the average operating cost in the presence of errors in controlling aircraft to a specified landing time.

  11. Physical limits and design principles for plant and fungal movements.

    PubMed

    Skotheim, Jan M; Mahadevan, L

    2005-05-27

    The typical scales for plant and fungal movements vary over many orders of magnitude in time and length, but they are ultimately based on hydraulics and mechanics. We show that quantification of the length and time scales involved in plant and fungal motions leads to a natural classification, whose physical basis can be understood through an analysis of the mechanics of water transport through an elastic tissue. Our study also suggests a design principle for nonmuscular hydraulically actuated structures: Rapid actuation requires either small size or the enhancement of motion on large scales via elastic instabilities.

  12. Design for Natural Breast Augmentation: The ICE Principle.

    PubMed

    Mallucci, Patrick; Branford, Olivier Alexandre

    2016-06-01

    The authors' published studies have helped define breast beauty in outlining key parameters that contribute to breast attractiveness. The "ICE" principle puts design into practice. It is a simplified formula for inframammary fold incision planning as part of the process for determining implant selection and placement to reproduce the 45:55 ratio previously described as fundamental to natural breast appearance. The formula is as follows: implant dimensions (I) - capacity of the breast (C) = excess tissue required (E). The aim of this study was to test the accuracy of the ICE principle for producing consistent natural beautiful results in breast augmentation. A prospective analysis of 50 consecutive women undergoing primary breast augmentation by means of an inframammary fold incision with anatomical or round implants was performed. The ICE principle was applied to all cases to determine implant selection, placement, and incision position. Changes in parameters between preoperative and postoperative digital clinical photographs were analyzed. The mean upper pole-to-lower pole ratio changed from 52:48 preoperatively to 45:55 postoperatively (p < 0.0001). Mean nipple angulation was also statistically significantly elevated from 11 degrees to 19 degrees skyward (p ≤ 0.0005). Accuracy of incision placement in the fold was 99.7 percent on the right and 99.6 percent on the left, with a standard error of only 0.2 percent. There was a reduction in variability for all key parameters. The authors have shown using the simple ICE principle for surgical planning in breast augmentation that attractive natural breasts may be achieved consistently and with precision. Therapeutic, IV.

  13. Architectural design of heterogeneous metallic nanocrystals--principles and processes.

    PubMed

    Yu, Yue; Zhang, Qingbo; Yao, Qiaofeng; Xie, Jianping; Lee, Jim Yang

    2014-12-16

    CONSPECTUS: Heterogeneous metal nanocrystals (HMNCs) are a natural extension of simple metal nanocrystals (NCs), but as a research topic, they have been much less explored until recently. HMNCs are formed by integrating metal NCs of different compositions into a common entity, similar to the way atoms are bonded to form molecules. HMNCs can be built to exhibit an unprecedented architectural diversity and complexity by programming the arrangement of the NC building blocks ("unit NCs"). The architectural engineering of HMNCs involves the design and fabrication of the architecture-determining elements (ADEs), i.e., unit NCs with precise control of shape and size, and their relative positions in the design. Similar to molecular engineering, where structural diversity is used to create more property variations for application explorations, the architectural engineering of HMNCs can similarly increase the utility of metal NCs by offering a suite of properties to support multifunctionality in applications. The architectural engineering of HMNCs calls for processes and operations that can execute the design. Some enabling technologies already exist in the form of classical micro- and macroscale fabrication techniques, such as masking and etching. These processes, when used singly or in combination, are fully capable of fabricating nanoscopic objects. What is needed is a detailed understanding of the engineering control of ADEs and the translation of these principles into actual processes. For simplicity of execution, these processes should be integrated into a common reaction system and yet retain independence of control. The key to architectural diversity is therefore the independent controllability of each ADE in the design blueprint. The right chemical tools must be applied under the right circumstances in order to achieve the desired outcome. In this Account, after a short illustration of the infinite possibility of combining different ADEs to create HMNC design

  14. Evolutionary design of non-frustrated networks of phase-repulsive oscillators

    PubMed Central

    Levnajić, Zoran

    2012-01-01

    Evolutionary optimisation algorithm is employed to design networks of phase-repulsive oscillators that achieve an anti-phase synchronised state. By introducing the link frustration, the evolutionary process is implemented by rewiring the links with probability proportional to their frustration, until the final network displaying a unique non-frustrated dynamical state is reached. Resulting networks are bipartite and with zero clustering. In addition, the designed non-frustrated anti-phase synchronised networks display a clear topological scale. This contrasts usually studied cases of networks with phase-attractive dynamics, whose performance towards full synchronisation is typically enhanced by the presence of a topological hierarchy. PMID:23243494

  15. Evolutionary engineering for industrial microbiology.

    PubMed

    Vanee, Niti; Fisher, Adam B; Fong, Stephen S

    2012-01-01

    Superficially, evolutionary engineering is a paradoxical field that balances competing interests. In natural settings, evolution iteratively selects and enriches subpopulations that are best adapted to a particular ecological niche using random processes such as genetic mutation. In engineering desired approaches utilize rational prospective design to address targeted problems. When considering details of evolutionary and engineering processes, more commonality can be found. Engineering relies on detailed knowledge of the problem parameters and design properties in order to predict design outcomes that would be an optimized solution. When detailed knowledge of a system is lacking, engineers often employ algorithmic search strategies to identify empirical solutions. Evolution epitomizes this iterative optimization by continuously diversifying design options from a parental design, and then selecting the progeny designs that represent satisfactory solutions. In this chapter, the technique of applying the natural principles of evolution to engineer microbes for industrial applications is discussed to highlight the challenges and principles of evolutionary engineering.

  16. Top 10 principles for designing healthy coastal ecosystems

    USGS Publications Warehouse

    Gaydos, Joseph K.; Dierauf, Leslie; Kirby, Grant; Brosnan, Deborah; Gilardi, Kirsten; Davis, Gary E.

    2008-01-01

    Like other coastal zones around the world, the inland sea ecosystem of Washington (USA) and British Columbia (Canada), an area known as the Salish Sea, is changing under pressure from a growing human population, conversion of native forest and shoreline habitat to urban development, toxic contamination of sediments and species, and overharvest of resources. While billions of dollars have been spent trying to restore other coastal ecosystems around the world, there still is no successful model for restoring estuarine or marine ecosystems like the Salish Sea. Despite the lack of a guiding model, major ecological principles do exist that should be applied as people work to design the Salish Sea and other large marine ecosystems for the future. We suggest that the following 10 ecological principles serve as a foundation for educating the public and for designing a healthy Salish Sea and other coastal ecosystems for future generations: (1) Think ecosystem: political boundaries are arbitrary; (2) Account for ecosystem connectivity; (3) Understand the food web; (4) Avoid fragmentation; (5) Respect ecosystem integrity; (6) Support nature's resilience; (7) Value nature: it's money in your pocket; (8) Watch wildlife health; (9) Plan for extremes; and (10) Share the knowledge.

  17. Achieving integration in mixed methods designs-principles and practices.

    PubMed

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

    2013-12-01

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

  18. Seeing is believing: good graphic design principles for medical research.

    PubMed

    Duke, Susan P; Bancken, Fabrice; Crowe, Brenda; Soukup, Mat; Botsis, Taxiarchis; Forshee, Richard

    2015-09-30

    Have you noticed when you browse a book, journal, study report, or product label how your eye is drawn to figures more than to words and tables? Statistical graphs are powerful ways to transparently and succinctly communicate the key points of medical research. Furthermore, the graphic design itself adds to the clarity of the messages in the data. The goal of this paper is to provide a mechanism for selecting the appropriate graph to thoughtfully construct quality deliverables using good graphic design principles. Examples are motivated by the efforts of a Safety Graphics Working Group that consisted of scientists from the pharmaceutical industry, Food and Drug Administration, and academic institutions. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Design principles for clinical network-based proteomics.

    PubMed

    Goh, Wilson Wen Bin; Wong, Limsoon

    2016-07-01

    Integrating biological networks with proteomics is a tantalizing option for system-level analysis; for example it can help remove false-positives from proteomics data and improve coverage by detecting false-negatives, as well as resolving inconsistent inter-sample protein expression due to biological heterogeneity. Yet, designing a robust network-based analysis strategy on proteomics data is nontrivial. The issues include dealing with test set bias caused by, for example, inappropriate normalization procedure, devising appropriate benchmarking criteria and formulating statistically robust feature-selection techniques. Given the increasing importance of proteomics in contemporary clinical studies, more powerful network-based approaches are needed. We provide some design principles and considerations that can help achieve this, while taking into account the idiosyncrasies of proteomics data.

  20. First Principles Design of Non-Centrosymmetric Metal Oxides

    NASA Astrophysics Data System (ADS)

    Young, Joshua Aaron

    The lack of an inversion center in a material's crystal structure can result in many useful material properties, such as ferroelectricity, piezoelectricity and non-linear optical behavior. Recently, the desire for low power, high efficiency electronic devices has spurred increased interest in these phenomena, especially ferroelectricity, as well as their coupling to other material properties. By studying and understanding the fundamental structure-property relationships present in non-centrosymmetric materials, it is possible to purposefully engineer new compounds with the desired "acentric" qualities through crystal engineering. The families of ABO3 perovskite and ABO2.5 perovskite-derived brownmillerite oxides are ideal for such studies due to their wide range of possible chemistries, as well as ground states that are highly tunable owing to strong electron-lattice coupling. Furthermore, control over the B-O-B bond angles through epitaxial strain or chemical substitution allows for the rapid development of new emergent properties. In this dissertation, I formulate the crystal-chemistry criteria necessary to design functional non-centrosymmetric oxides using first-principles density functional theory calculations. Recently, chemically ordered (AA')B2O 6 oxides have been shown to display a new form of rotation-induced ferroelectric polarizations. I now extend this property-design methodology to alternative compositions and crystal classes and show it is possible to induce a host of new phenomena. This dissertation will address: 1) the formulation of predictive models allowing for a priori design of polar oxides, 2) the optimization of properties exhibited by these materials through chemical substitution and cation ordering, and 3) the use of strain to control the stability of new phases. Completion of this work has led to a deeper understanding of how atomic structural features determine the physical properties of oxides, as well as the successful elucidation of

  1. Designing Aquatic Exercise Programs--Three Guiding Principles.

    ERIC Educational Resources Information Center

    White, Sue W.; Landis, Larry M.

    1989-01-01

    Three guiding principles provide the planner of aquatic exercise programs with a model that helps to ensure an effective program: principles of resource availability and allocation; the principle of fit, which involves matching instructor leadership style with program objectives; and the principle of attitude and perception modification. (IAH)

  2. Taking evolutionary circuit design from experimentation to implementation: some useful techniques and a silicon demonstration

    NASA Technical Reports Server (NTRS)

    Stoica, A.; Zebulum, R. S.; Guo, X.; Keymeulen, D.; Ferguson, M. I.; Duong, V.

    2004-01-01

    Current techniques in evolutionary synthesis of analogue and digital circuits designed at transistor level have focused on achieving the desired functional response, without paying sufficient attention to issues needed for a practical implementation of the resulting solution. No silicon fabrication of circuits with topologies designed by evolution has been done before, leaving open questions on the feasibility of the evolutionary circuit design approach, as well as on how high-performance, robust, or portable such designs could be when implemented in hardware. It is argued that moving from evolutionary 'design-for experimentation' to 'design-for-implementation' requires, beyond inclusion in the fitness function of measures indicative of circuit evaluation factors such as power consumption and robustness to temperature variations, the addition of certain evaluation techniques that are not common in conventional design. Several such techniques that were found to be useful in evolving designs for implementation are presented; some are general, and some are particular to the problem domain of transistor-level logic design, used here as a target application. The example used here is a multifunction NAND/NOR logic gate circuit, for which evolution obtained a creative circuit topology more compact than what has been achieved by multiplexing a NAND and a NOR gate. The circuit was fabricated in a 0.5 mum CMOS technology and silicon tests showed good correspondence with the simulations.

  3. Taking evolutionary circuit design from experimentation to implementation: some useful techniques and a silicon demonstration

    NASA Technical Reports Server (NTRS)

    Stoica, A.; Zebulum, R. S.; Guo, X.; Keymeulen, D.; Ferguson, M. I.; Duong, V.

    2004-01-01

    Current techniques in evolutionary synthesis of analogue and digital circuits designed at transistor level have focused on achieving the desired functional response, without paying sufficient attention to issues needed for a practical implementation of the resulting solution. No silicon fabrication of circuits with topologies designed by evolution has been done before, leaving open questions on the feasibility of the evolutionary circuit design approach, as well as on how high-performance, robust, or portable such designs could be when implemented in hardware. It is argued that moving from evolutionary 'design-for experimentation' to 'design-for-implementation' requires, beyond inclusion in the fitness function of measures indicative of circuit evaluation factors such as power consumption and robustness to temperature variations, the addition of certain evaluation techniques that are not common in conventional design. Several such techniques that were found to be useful in evolving designs for implementation are presented; some are general, and some are particular to the problem domain of transistor-level logic design, used here as a target application. The example used here is a multifunction NAND/NOR logic gate circuit, for which evolution obtained a creative circuit topology more compact than what has been achieved by multiplexing a NAND and a NOR gate. The circuit was fabricated in a 0.5 mum CMOS technology and silicon tests showed good correspondence with the simulations.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-05-01

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

  6. Design Principles for Oxygen Reduction and Evolution on Oxide Catalysts

    NASA Astrophysics Data System (ADS)

    Shao-Horn, Yang

    2012-02-01

    Driven by growing concerns about global warming and the depletion of petroleum resources, developing renewable energy production and storage technologies represent one of the major scientific challenges of the 21^st century. A critical element in pursuit of this quest is the discovery of efficient and cost-effective catalysts used in solar fuel production via electrochemical energy conversion processes such as oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), both of which are central to the efficiencies of direct-solar and electrolytic water-splitting devices, fuel cells, and metal-air batteries. Although the Sabatier's principle provides a qualitative argument in tuning catalytic activity by varying the bond strength between catalyst surface and reactant/product (neither too strong nor too weak leading to the maximum activity at moderate bond strength), it has no predictive power to find catalysts with enhanced activity. Identifying a ``design principle'' that links catalyst properties to the catalytic activity is critical to accelerate the search for highly active catalysts based on abundant elements, and minimize the use of precious metals. Here we establish a molecular principle that governs the activities of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) for oxide catalysts, where the activities primarily correlate to the σ* orbital (``eg'') occupation of surface transition-metal cations established by systematic examination of more than ten to fifteen transition-metal oxides. The intrinsic ORR and OER activities exhibit a volcano-shaped dependence on the eg occupancy and the activities peak at an eg occupancy close to unity. Our findings reflect the critical influence of the σ* orbital on the energetics of surface reaction intermediates on surface transition metal ions such as the O2^2-/OH^- displacement and the OH^- regeneration, and thus highlight the importance of surface oxide electronic structure in controlling

  7. Synthetic RNAs for Gene Regulation: Design Principles and Computational Tools

    PubMed Central

    Laganà, Alessandro; Shasha, Dennis; Croce, Carlo Maria

    2014-01-01

    The use of synthetic non-coding RNAs for post-transcriptional regulation of gene expression has not only become a standard laboratory tool for gene functional studies but it has also opened up new perspectives in the design of new and potentially promising therapeutic strategies. Bioinformatics has provided researchers with a variety of tools for the design, the analysis, and the evaluation of RNAi agents such as small-interfering RNA (siRNA), short-hairpin RNA (shRNA), artificial microRNA (a-miR), and microRNA sponges. More recently, a new system for genome engineering based on the bacterial CRISPR-Cas9 system (Clustered Regularly Interspaced Short Palindromic Repeats), was shown to have the potential to also regulate gene expression at both transcriptional and post-transcriptional level in a more specific way. In this mini review, we present RNAi and CRISPRi design principles and discuss the advantages and limitations of the current design approaches. PMID:25566532

  8. Design of synthetic biological logic circuits based on evolutionary algorithm.

    PubMed

    Chuang, Chia-Hua; Lin, Chun-Liang; Chang, Yen-Chang; Jennawasin, Tanagorn; Chen, Po-Kuei

    2013-08-01

    The construction of an artificial biological logic circuit using systematic strategy is recognised as one of the most important topics for the development of synthetic biology. In this study, a real-structured genetic algorithm (RSGA), which combines general advantages of the traditional real genetic algorithm with those of the structured genetic algorithm, is proposed to deal with the biological logic circuit design problem. A general model with the cis-regulatory input function and appropriate promoter activity functions is proposed to synthesise a wide variety of fundamental logic gates such as NOT, Buffer, AND, OR, NAND, NOR and XOR. The results obtained can be extended to synthesise advanced combinational and sequential logic circuits by topologically distinct connections. The resulting optimal design of these logic gates and circuits are established via the RSGA. The in silico computer-based modelling technology has been verified showing its great advantages in the purpose.

  9. Artificial Metamorphosis: Evolutionary Design of Transforming, Soft-Bodied Robots.

    PubMed

    Joachimczak, Michał; Suzuki, Reiji; Arita, Takaya

    2016-01-01

    We show how the concept of metamorphosis, together with a biologically inspired model of multicellular development, can be used to evolve soft-bodied robots that are adapted to two very different tasks, such as being able to move in an aquatic and in a terrestrial environment. Each evolved solution defines two pairs of morphologies and controllers, together with a process of transforming one pair into the other. Animats develop from a single cell and grow through cellular divisions and deaths until they reach an initial larval form adapted to a first environment. To obtain the adult form adapted to a second environment, the larva undergoes metamorphosis, during which new cells are added or removed and its controller is modified. Importantly, our approach assumes nothing about what morphologies or methods of locomotion are preferred. Instead, it successfully searches the vast space of possible designs and comes up with complex, surprising, lifelike solutions that are reminiscent of amphibian metamorphosis. We analyze obtained solutions and investigate whether the morphological changes during metamorphosis are indeed adaptive. We then compare the effectiveness of three different types of selective pressures used to evolve metamorphic individuals. Finally, we investigate potential advantages of using metamorphosis to automatically produce soft-bodied designs by comparing the performance of metamorphic individuals with their specialized counterparts and designs that are robust to both environments.

  10. Evolutionary computing for the design search and optimization of space vehicle power subsystems

    NASA Technical Reports Server (NTRS)

    Kordon, M.; Klimeck, G.; Hanks, D.

    2004-01-01

    Evolutionary computing has proven to be a straightforward and robust approach for optimizing a wide range of difficult analysis and design problems. This paper discusses the application of these techniques to an existing space vehicle power subsystem resource and performance analysis simulation in a parallel processing environment.

  11. Rapid Preliminary Design of Interplanetary Trajectories Using the Evolutionary Mission Trajectory Generator

    NASA Technical Reports Server (NTRS)

    Englander, Jacob

    2016-01-01

    This set of tutorial slides is an introduction to the Evolutionary Mission Trajectory Generator (EMTG), NASA Goddard Space Flight Center's autonomous tool for preliminary design of interplanetary missions. This slide set covers the basics of creating and post-processing simple interplanetary missions in EMTG using both high-thrust chemical and low-thrust electric propulsion along with a variety of operational constraints.

  12. Design Principles for a Compact High Average Power IR FEL

    SciTech Connect

    Lia Merminga; Steve Benson

    2001-08-01

    Progress in superconducting rf (srf) technology has led to dramatic changes in cryogenic losses, cavity gradients, and microphonic levels. Design principles for a compact high average power Energy Recovery FEL at IR wavelengths, consistent with the state of the art in srf, are outlined, High accelerating gradients, of order 20 MV/m at Q{sub 0}{approx}1x10{sup 10} possible at rf frequencies of 1300 MHz and 1500 MHz, allow for a single-cryomodule linac, with minimum cryogenic losses. Filling every rf bucket, at these high frequencies, results in high average current at relatively low charge per bunch, thereby greatly ameliorating all single bunch phenomena, such as wakefields and coherent synchrotron radiation. These principles are applied to derive self-consistent sets of parameters for 100 kW and 1 MW average power IR FELs and are compared with low frequency solutions. This work supported by U.S. DOE Contract No. DE-AC05-84ER40150, the Commonwealth of Virginia and the Laser Processing Consortium.

  13. Ionomer Design Principles for Single Ion-Conducting Energy Materials

    NASA Astrophysics Data System (ADS)

    Colby, Ralph; Liang, Siwei; Liu, Wenjuan; Hyeok Choi, U.; Runt, James; Shiau, Huai-Suen; Janik, Michael

    2012-02-01

    Single-ion conducting ionomers with low glass transition temperature, high dielectric constant and containing bulky ions with diffuse charge, are needed for polymer membranes that transport small counterions. Overarching design principles emerging from quantum chemistry calculations suggest that diffuse charge can be attained from simple considerations of atomic electronegativity. For lithium or sodium batteries, perfluorinated tetraphenyl borate ionomers with solvating polar comonomers are proposed. For fluoride or hydroxide batteries and for iodide transporting solar cells, tetra-alkyl phosphonium ionomers with anion receptors are proposed. First attempts to construct such ionomers to test these ideas will be discussed, with results from dielectric spectroscopy to measure conductivity, dielectric constant and number density of simultaneously conducting ions.

  14. Design (and) principles of nuclear dynamics in Stockholm

    PubMed Central

    Shav-Tal, Yaron; Lammerding, Jan

    2015-01-01

    The structural organization of the nucleus and its content has drawn increasing interest in recent years, as it is has become evident that the spatial and temporal arrangement of the genome and associated structures plays a crucial role in transcriptional regulation and numerous other functions. Shining light on the dynamic nature of this organization, along with the processes controlling it, were the topics of the Wenner-Gren Foundations international symposium "Nuclear Dynamics: Design (and) Principles." The meeting, organized by Piorgiogio Percipalle, Maria Vartiainen, Neus Visa, and Ann-Kristin Östlund-Farrants, brought over 60 participants, including 20 international speakers, to Stockholm, Sweden from August 19–22, 2015 to share the latest developments in the field. Given the unpublished nature of many of the talks, we have focused on covering the discussed topics and highlighting the latest trends in this exciting and rapidly evolving field. PMID:26730816

  15. Carbon-rich icosahedral boron carbide designed from first principles

    SciTech Connect

    Jay, Antoine; Vast, Nathalie; Sjakste, Jelena; Duparc, Olivier Hardouin

    2014-07-21

    The carbon-rich boron-carbide (B{sub 11}C)C-C has been designed from first principles within the density functional theory. With respect to the most common boron carbide at 20% carbon concentration B{sub 4}C, the structural modification consists in removing boron atoms from the chains linking (B{sub 11}C) icosahedra. With C-C instead of C-B-C chains, the formation of vacancies is shown to be hindered, leading to enhanced mechanical strength with respect to B{sub 4}C. The phonon frequencies and elastic constants turn out to prove the stability of the carbon-rich phase, and important fingerprints for its characterization have been identified.

  16. Design principles and specificity in biological networks with cross activation

    NASA Astrophysics Data System (ADS)

    Hu, Bo; Levine, Herbert; Rappel, Wouter-Jan

    2011-04-01

    Cells sense and respond to diverse environmental stimuli using a set of intracellular signaling components. Often, the signal transduction pathways contain shared components which lead to cross activation at different levels of the pathway. To discover the design principles that ensure signaling specificity is a challenging task, especially for pathways that contain numerous components. Here, we present an analysis of cross-activating pathways and show that a general inhibitory scheme, asymmetric hierarchical inhibition, is sufficient to ensure signaling specificity. Based on this inhibitory scheme, we are able to enumerate all possible network topologies containing two inhibitory links that guarantee specificity. Furthermore, we apply our methodology to the mating and filamentous growth pathways of the yeast model system Saccharomyces cerevisiae. We enumerate the possible ways to wire this model system and determine which topology is consistent with experimental data.

  17. Using the principles of circadian physiology enhances shift schedule design

    SciTech Connect

    Connolly, J.J.; Moore-Ede, M.C.

    1987-01-01

    Nuclear power plants must operate 24 h, 7 days a week. For the most part, shift schedules currently in use at nuclear power plants have been designed to meet operational needs without considering the biological clocks of the human operators. The development of schedules that also take circadian principles into account is a positive step that can be taken to improve plant safety by optimizing operator alertness. These schedules reduce the probability of human errors especially during backshifts. In addition, training programs that teach round-the-clock workers how to deal with the problems of shiftwork can help to optimize performance and alertness. These programs teach shiftworkers the underlying causes of the sleep problems associated with shiftwork and also provide coping strategies for improving sleep and dealing with the transition between shifts. When these training programs are coupled with an improved schedule, the problems associated with working round-the-clock can be significantly reduced.

  18. Evolutionary algorithm for the neutrino factory front end design

    SciTech Connect

    Poklonskiy, Alexey A.; Neuffer, David; /Fermilab

    2009-01-01

    The Neutrino Factory is an important tool in the long-term neutrino physics program. Substantial effort is put internationally into designing this facility in order to achieve desired performance within the allotted budget. This accelerator is a secondary beam machine: neutrinos are produced by means of the decay of muons. Muons, in turn, are produced by the decay of pions, produced by hitting the target by a beam of accelerated protons suitable for acceleration. Due to the physics of this process, extra conditioning of the pion beam coming from the target is needed in order to effectively perform subsequent acceleration. The subsystem of the Neutrino Factory that performs this conditioning is called Front End, its main performance characteristic is the number of the produced muons.

  19. Design principles for hydrogen evolution reaction catalyst materials

    DOE PAGES

    Strmcnik, Dusan; Lopes, Pietro Papa; Genorio, Bostjan; ...

    2016-04-19

    Design and synthesis of active, stable and cost-effective materials for efficient hydrogen production (hydrogen evolution reaction, HER) is of paramount importance for the successful deployment of hydrogen -based alternative energy technologies. The HER, seemingly one of the simplest electrochemical reactions, has served for decades to bridge the gap between fundamental electrocatalysis and practical catalyst design. However, there are still many open questions that need to be answered before it would be possible to claim that design principles of catalyst materials are fully developed for the efficient hydrogen production. Here in this review, by summarizing key results for the HER onmore » well-characterized electrochemical interfaces in acidic and alkaline media, we have broadened our understanding of the HER in the whole range of pH by considering three main parameters: the nature of the proton donor (H3O+ in acid and H2O in alkaline), the energy of adsorption of Had and OHad, and the presence of spectator species. Simply by considering these three parameters we show that great deal has already been learned and new trends are beginning to emerge, giving some predictive ability with respect to the nature of electrochemical interface and electrocatalytic activity of the HER.« less

  20. Design principles for hydrogen evolution reaction catalyst materials

    SciTech Connect

    Strmcnik, Dusan; Lopes, Pietro Papa; Genorio, Bostjan; Stamenkovic, Vojislav R.; Markovic, Nenad M.

    2016-04-19

    Design and synthesis of active, stable and cost-effective materials for efficient hydrogen production (hydrogen evolution reaction, HER) is of paramount importance for the successful deployment of hydrogen -based alternative energy technologies. The HER, seemingly one of the simplest electrochemical reactions, has served for decades to bridge the gap between fundamental electrocatalysis and practical catalyst design. However, there are still many open questions that need to be answered before it would be possible to claim that design principles of catalyst materials are fully developed for the efficient hydrogen production. Here in this review, by summarizing key results for the HER on well-characterized electrochemical interfaces in acidic and alkaline media, we have broadened our understanding of the HER in the whole range of pH by considering three main parameters: the nature of the proton donor (H3O+ in acid and H2O in alkaline), the energy of adsorption of Had and OHad, and the presence of spectator species. Simply by considering these three parameters we show that great deal has already been learned and new trends are beginning to emerge, giving some predictive ability with respect to the nature of electrochemical interface and electrocatalytic activity of the HER.

  1. High throughput exploration of ZrxSi1 - xO2 dielectrics by evolutionary first-principles approaches

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Zeng, Qingfeng; Oganov, Artem R.; Dong, Dong; Liu, Yunfang

    2014-11-01

    The high throughput approaches aim to discover, screen and optimize materials in a cost-effective way and to shorten their time-to-market. However, computational approaches typically involve a combinatorial explosion problem, to deal with which, we adopted hybrid evolutionary algorithms together with first-principle calculations to explore possible stable and metastable crystal structures of ZrO2-SiO2 dielectrics. The calculation reproduced two already known structures (I41 / amd-ZrSiO4 and I41 / a-ZrSiO4) and predicted two new thermodynamically metastable structures Zr3SiO8 (P 4 bar 3 m) and ZrSi2O6 (P 3 bar 1 m). At ambient pressure, the only thermodynamically stable zirconium silicate is I41 / amd-ZrSiO4 (zircon). Dynamical stability of the new phases has been verified by phonon calculations, and their static dielectric constants are higher than that of the known phases of ZrSiO4. Band structure, density of state, electron localization function and Bader charges are presented and discussed. The new metastable structures are insulators with the DFT band gaps of 3.65 and 3.52 eV, respectively. Calculations show that P 4 bar 3 m-Zr3SiO8 has high dielectric constant (∼20.7), high refractive index (∼2.4) and strong dispersion of light. Global optimization of the dielectric fitness (electric energy density) shows that among crystalline phases of ZrO2-SiO2, maximum occurs for I41 / a-ZrSiO4.

  2. Principles and designs of the iseikonic lenses for near vision.

    PubMed

    Wang, Guang-Ji

    2006-12-01

    The purposes of this study were to find the problems of afocal iseikonic lenses as used for near vision and to elaborate the principles and designs of the ideal near iseikonic lenses. By analyzing the image-object relationship and imaging processes, the formulae were derived to quantitatively and qualitatively describe two errors of afocal iseikonic lenses as used for near vision: 1) inequality of accommodative demands to both eyes and 2) the difference between the actual and the nominal magnification. Formulae were derived to calculate and design the ideal near iseikonic lenses. For iseikonic lenses now used for near vision, inequality of accommodative demands to both eyes and difference between the actual and nominal magnification increased as the magnification increased and the viewing distance decreased. Afocal iseikonic lenses have significant inequality of accommodative demands to both eyes with 3% magnification at a viewing distance of 25 cm or with 5% magnification at 40 cm. The ideal near iseikonic lenses were found to be flatter than the afocal ones. A series of the ideal near iseikonic lenses were designed with some practical considerations. The central thickness and the refractive index of the lenses affect magnification and lens shape. The thicker the lenses, the higher the magnification. The higher refractive index also gives higher magnification. Iseikonic lens design is much different for distance and near vision. When the iseikonic lenses are used at a distance other than the designated distance, they will cause blurred vision and artificial aniseikonia as a result of inequality of accommodative demands to both eyes. In research as well as clinical settings, it is necessary to apply the ideal near iseikonic lenses for near vision.

  3. Three Principles of Perception for Instructional Interface Design.

    ERIC Educational Resources Information Center

    Lohr, Linda L.

    2000-01-01

    Discusses graphical user interfaces used for instructional purposes in educational environments, which promote learning goals, and in support environments, which promote performance goals. Explains three key principles of perception and gives guidelines for their use, including the figure/ground principle, the hierarchy principle, and the gestalt…

  4. Design principles for developing an efficient clinical anatomy course.

    PubMed

    Rizzolo, Lawrence J; Stewart, William B; O'Brien, Michael; Haims, Andrew; Rando, William; Abrahams, James; Dunne, Shane; Wang, Silas; Aden, Marcus

    2006-03-01

    The exponential growth of medical knowledge presents a challenge for the medical school curriculum. Because anatomy is traditionally a long course, it is an attractive target to reduce course hours, yet designing courses that produce students with less understanding of human anatomy is not a viable option. Faced with the challenge of teaching more anatomy with less time, we set out to understand how students employ instructional media to learn anatomy inside and outside of the classroom. We developed a series of pilot programs to explore how students learn anatomy and, in particular, how they combine instructional technology with more traditional classroom and laboratory-based learning. We then integrated what we learned with principles of effective instruction to design a course that makes the most efficient use of students' in-class and out-of-class learning. Overall, we concluded that our new anatomy course needed to focus on transforming how medical students think, reason, and learn. We are currently testing the hypothesis that this novel approach will enhance the ability of students to recall and expand their base of anatomical knowledge throughout their medical school training and beyond.

  5. First-principles structural design of superhard materials.

    PubMed

    Zhang, Xinxin; Wang, Yanchao; Lv, Jian; Zhu, Chunye; Li, Qian; Zhang, Miao; Li, Quan; Ma, Yanming

    2013-03-21

    We reported a developed methodology to design superhard materials for given chemical systems under external conditions (here, pressure). The new approach is based on the CALYPSO algorithm and requires only the chemical compositions to predict the hardness vs. energy map, from which the energetically preferable superhard structures are readily accessible. In contrast to the traditional ground state structure prediction method where the total energy was solely used as the fitness function, here we adopted hardness as the fitness function in combination with the first-principles calculation to construct the hardness vs. energy map by seeking a proper balance between hardness and energy for a better mechanical description of given chemical systems. To allow a universal calculation on the hardness for the predicted structure, we have improved the earlier hardness model based on bond strength by applying the Laplacian matrix to account for the highly anisotropic and molecular systems. We benchmarked our approach in typical superhard systems, such as elemental carbon, binary B-N, and ternary B-C-N compounds. Nearly all the experimentally known and most of the earlier theoretical superhard structures have been successfully reproduced. The results suggested that our approach is reliable and can be widely applied into design of new superhard materials.

  6. System Design under Uncertainty: Evolutionary Optimization of the Gravity Probe-B Spacecraft

    NASA Technical Reports Server (NTRS)

    Pullen, Samuel P.; Parkinson, Bradford W.

    1994-01-01

    This paper discusses the application of evolutionary random-search algorithms (Simulated Annealing and Genetic Algorithms) to the problem of spacecraft design under performance uncertainty. Traditionally, spacecraft performance uncertainty has been measured by reliability. Published algorithms for reliability optimization are seldom used in practice because they oversimplify reality. The algorithm developed here uses random-search optimization to allow us to model the problem more realistically. Monte Carlo simulations are used to evaluate the objective function for each trial design solution. These methods have been applied to the Gravity Probe-B (GP-B) spacecraft being developed at Stanford University for launch in 1999, Results of the algorithm developed here for GP-13 are shown, and their implications for design optimization by evolutionary algorithms are discussed.

  7. Design principles for engaging and retaining virtual citizen scientists.

    PubMed

    Wald, Dara M; Longo, Justin; Dobell, A R

    2016-06-01

    Citizen science initiatives encourage volunteer participants to collect and interpret data and contribute to formal scientific projects. The growth of virtual citizen science (VCS), facilitated through websites and mobile applications since the mid-2000s, has been driven by a combination of software innovations and mobile technologies, growing scientific data flows without commensurate increases in resources to handle them, and the desire of internet-connected participants to contribute to collective outputs. However, the increasing availability of internet-based activities requires individual VCS projects to compete for the attention of volunteers and promote their long-term retention. We examined program and platform design principles that might allow VCS initiatives to compete more effectively for volunteers, increase productivity of project participants, and retain contributors over time. We surveyed key personnel engaged in managing a sample of VCS projects to identify the principles and practices they pursued for these purposes and led a team in a heuristic evaluation of volunteer engagement, website or application usability, and participant retention. We received 40 completed survey responses (33% response rate) and completed a heuristic evaluation of 20 VCS program sites. The majority of the VCS programs focused on scientific outcomes, whereas the educational and social benefits of program participation, variables that are consistently ranked as important for volunteer engagement and retention, were incidental. Evaluators indicated usability, across most of the VCS program sites, was higher and less variable than the ratings for participant engagement and retention. In the context of growing competition for the attention of internet volunteers, increased attention to the motivations of virtual citizen scientists may help VCS programs sustain the necessary engagement and retention of their volunteers.

  8. Principles for designing future regimens for multidrug-resistant tuberculosis.

    PubMed

    Brigden, Grania; Nyang'wa, Bern-Thomas; du Cros, Philipp; Varaine, Francis; Hughes, Jennifer; Rich, Michael; Horsburgh, C Robert; Mitnick, Carole D; Nuermberger, Eric; McIlleron, Helen; Phillips, Patrick P J; Balasegaram, Manica

    2014-01-01

    Fewer than 20% of patients with multidrug-resistant (MDR) tuberculosis are receiving treatment and there is an urgent need to scale up treatment programmes. One of the biggest barriers to scale-up is the treatment regimen, which is lengthy, complex, ineffective, poorly tolerated and expensive. For the first time in over 50 years, new drugs have been developed specifically to treat tuberculosis, with bedaquiline and potentially delamanid expected to be available soon for treatment of MDR cases. However, if the new drugs are merely added to the current treatment regimen, the new regimen will be at least as lengthy, cumbersome and toxic as the existing one. There is an urgent need for strategy and evidence on how to maximize the potential of the new drugs to improve outcomes and shorten treatment. We devised eight key principles for designing future treatment regimens to ensure that, once they are proven safe in clinical trials, they will be clinically effective and programmatically practicable. Regimens should contain at least one new class of drug; be broadly applicable for use against MDR and extensively drug-resistant Mycobacterium tuberculosis complex strains; contain three to five effective drugs, each from a different drug class; be delivered orally; have a simple dosing schedule; have a good side-effect profile that allows limited monitoring; last a maximum of 6 months; and have minimal interaction with antiretrovirals. Following these principles will maximize the potential of new compounds and help to overcome the clinical and programmatic disadvantages and scale-up constraints that plague the current regimen.

  9. Principles for designing future regimens for multidrug-resistant tuberculosis

    PubMed Central

    Nyang’wa, Bern-Thomas; du Cros, Philipp; Varaine, Francis; Hughes, Jennifer; Rich, Michael; Horsburgh, C Robert; Mitnick, Carole D; Nuermberger, Eric; McIlleron, Helen; Phillips, Patrick PJ; Balasegaram, Manica

    2014-01-01

    Abstract Fewer than 20% of patients with multidrug-resistant (MDR) tuberculosis are receiving treatment and there is an urgent need to scale up treatment programmes. One of the biggest barriers to scale-up is the treatment regimen, which is lengthy, complex, ineffective, poorly tolerated and expensive. For the first time in over 50 years, new drugs have been developed specifically to treat tuberculosis, with bedaquiline and potentially delamanid expected to be available soon for treatment of MDR cases. However, if the new drugs are merely added to the current treatment regimen, the new regimen will be at least as lengthy, cumbersome and toxic as the existing one. There is an urgent need for strategy and evidence on how to maximize the potential of the new drugs to improve outcomes and shorten treatment. We devised eight key principles for designing future treatment regimens to ensure that, once they are proven safe in clinical trials, they will be clinically effective and programmatically practicable. Regimens should contain at least one new class of drug; be broadly applicable for use against MDR and extensively drug-resistant Mycobacterium tuberculosis complex strains; contain three to five effective drugs, each from a different drug class; be delivered orally; have a simple dosing schedule; have a good side-effect profile that allows limited monitoring; last a maximum of 6 months; and have minimal interaction with antiretrovirals. Following these principles will maximize the potential of new compounds and help to overcome the clinical and programmatic disadvantages and scale-up constraints that plague the current regimen. PMID:24391302

  10. Design of a dynamic model of genes with multiple autonomous regulatory modules by evolutionary computations

    PubMed Central

    Spirov, Alexander V.; Holloway, David M.

    2010-01-01

    A new approach to design a dynamic model of genes with multiple autonomous regulatory modules by evolutionary computations is proposed. The approach is based on Genetic Algorithms (GA), with new crossover operators especially designed for these purposes. The new operators use local homology between parental strings to preserve building blocks found by the algorithm. The approach exploits the subbasin-portal architecture of the fitness functions suitable for this kind of evolutionary modeling. This architecture is significant for Royal Road class fitness functions. Two real-life Systems Biology problems with such fitness functions are implemented here: evolution of the bacterial promoter rrnPl and of the enhancer of the Drosophila even-skipped gene. The effectiveness of the approach compared to standard GA is demonstrated on several benchmark and real-life tasks. PMID:20930945

  11. Design Principles in the Development of (Public) Health Information Infrastructures

    PubMed Central

    Neame, Roderick

    2012-01-01

    In this article the author outlines the key issues in the development of a regional health information infrastructure suitable for public health data collections. A set of 10 basic design and development principles as used and validated in the development of the successful New Zealand National Health Information Infrastructure in 1993 are put forward as a basis for future developments. The article emphasises the importance of securing clinical input into any health data that is collected, and suggests strategies whereby this may be achieved, including creating an information economy alongside the care economy. It is suggested that the role of government in such developments is to demonstrate leadership, to work with the sector to develop data, messaging and security standards, to establish key online indexes, to develop data warehouses and to create financial incentives for adoption of the infrastructure and the services it delivers to users. However experience suggests that government should refrain from getting involved in local care services data infrastructure, technology and management issues. PMID:23569626

  12. Design Principles and Algorithms for Air Traffic Arrival Scheduling

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Itoh, Eri

    2014-01-01

    This report presents design principles and algorithms for building a real-time scheduler of arrival aircraft based on a first-come-first-served (FCFS) scheduling protocol. The algorithms provide the conceptual and computational foundation for the Traffic Management Advisor (TMA) of the Center/terminal radar approach control facilities (TRACON) automation system, which comprises a set of decision support tools for managing arrival traffic at major airports in the United States. The primary objective of the scheduler is to assign arrival aircraft to a favorable landing runway and schedule them to land at times that minimize delays. A further objective of the scheduler is to allocate delays between high-altitude airspace far away from the airport and low-altitude airspace near the airport. A method of delay allocation is described that minimizes the average operating cost in the presence of errors in controlling aircraft to a specified landing time. This report is a revision of an earlier paper first presented as part of an Advisory Group for Aerospace Research and Development (AGARD) lecture series in September 1995. The authors, during vigorous discussions over the details of this paper, felt it was important to the air-trafficmanagement (ATM) community to revise and extend the original 1995 paper, providing more detail and clarity and thereby allowing future researchers to understand this foundational work as the basis for the TMA's scheduling algorithms.

  13. Design principles for radiation-resistant solid solutions

    NASA Astrophysics Data System (ADS)

    Schuler, Thomas; Trinkle, Dallas R.; Bellon, Pascal; Averback, Robert

    2017-05-01

    We develop a multiscale approach to quantify the increase in the recombined fraction of point defects under irradiation resulting from dilute solute additions to a solid solution. This methodology provides design principles for radiation-resistant materials. Using an existing database of solute diffusivities, we identify Sb as one of the most efficient solutes for this purpose in a Cu matrix. We perform density-functional-theory calculations to obtain binding and migration energies of Sb atoms, vacancies, and self-interstitial atoms in various configurations. The computed data informs the self-consistent mean-field formalism to calculate transport coefficients, allowing us to make quantitative predictions of the recombined fraction of point defects as a function of temperature and irradiation rate using homogeneous rate equations. We identify two different mechanisms according to which solutes lead to an increase in the recombined fraction of point defects; at low temperature, solutes slow down vacancies (kinetic effect), while at high temperature, solutes stabilize vacancies in the solid solution (thermodynamic effect). Extension to other metallic matrices and solutes are discussed.

  14. Biologically inspired binaural hearing aid algorithms: Design principles and effectiveness

    NASA Astrophysics Data System (ADS)

    Feng, Albert

    2002-05-01

    Despite rapid advances in the sophistication of hearing aid technology and microelectronics, listening in noise remains problematic for people with hearing impairment. To solve this problem two algorithms were designed for use in binaural hearing aid systems. The signal processing strategies are based on principles in auditory physiology and psychophysics: (a) the location/extraction (L/E) binaural computational scheme determines the directions of source locations and cancels noise by applying a simple subtraction method over every frequency band; and (b) the frequency-domain minimum-variance (FMV) scheme extracts a target sound from a known direction amidst multiple interfering sound sources. Both algorithms were evaluated using standard metrics such as signal-to-noise-ratio gain and articulation index. Results were compared with those from conventional adaptive beam-forming algorithms. In free-field tests with multiple interfering sound sources our algorithms performed better than conventional algorithms. Preliminary intelligibility and speech reception results in multitalker environments showed gains for every listener with normal or impaired hearing when the signals were processed in real time with the FMV binaural hearing aid algorithm. [Work supported by NIH-NIDCD Grant No. R21DC04840 and the Beckman Institute.

  15. Stomatal design principles in synthetic and real leaves.

    PubMed

    Zwieniecki, Maciej A; Haaning, Katrine S; Boyce, C Kevin; Jensen, Kaare H

    2016-11-01

    Stomata are portals in plant leaves that control gas exchange for photosynthesis, a process fundamental to life on Earth. Gas fluxes and plant productivity depend on external factors such as light, water and CO2 availability and on the geometrical properties of the stoma pores. The link between stoma geometry and environmental factors has informed a wide range of scientific fields-from agriculture to climate science, where observed variations in stoma size and density are used to infer prehistoric atmospheric CO2 content. However, the physical mechanisms and design principles responsible for major trends in stomatal patterning are not well understood. Here, we use a combination of biomimetic experiments and theory to rationalize the observed changes in stoma geometry. We show that the observed correlations between stoma size and density are consistent with the hypothesis that plants favour efficient use of space and maximum control of dynamic gas conductivity, and that the capacity for gas exchange in plants has remained constant over at least the last 325 Myr. Our analysis provides a new measure to gauge the relative performance of species based on their stomatal characteristics.

  16. Emerging engineering principles for yield improvement in microbial cell design

    PubMed Central

    Comba, Santiago; Arabolaza, Ana; Gramajo, Hugo

    2012-01-01

    Metabolic Engineering has undertaken a rapid transformation in the last ten years making real progress towards the production of a wide range of molecules and fine chemicals using a designed cellular host. However, the maximization of product yields through pathway optimization is a constant and central challenge of this field. Traditional methods used to improve the production of target compounds from engineered biosynthetic pathways in non-native hosts include: codon usage optimization, elimination of the accumulation of toxic intermediates or byproducts, enhanced production of rate-limiting enzymes, selection of appropriate promoter and ribosome binding sites, application of directed evolution of enzymes, and chassis re-circuit. Overall, these approaches tend to be specific for each engineering project rather than a systematic practice based on a more generalizable strategy. In this mini-review, we highlight some novel and extensive approaches and tools intended to address the improvement of a target product formation, founded in sophisticated principles such as dynamic control, pathway genes modularization, and flux modeling. PMID:24688676

  17. Emerging engineering principles for yield improvement in microbial cell design.

    PubMed

    Comba, Santiago; Arabolaza, Ana; Gramajo, Hugo

    2012-01-01

    Metabolic Engineering has undertaken a rapid transformation in the last ten years making real progress towards the production of a wide range of molecules and fine chemicals using a designed cellular host. However, the maximization of product yields through pathway optimization is a constant and central challenge of this field. Traditional methods used to improve the production of target compounds from engineered biosynthetic pathways in non-native hosts include: codon usage optimization, elimination of the accumulation of toxic intermediates or byproducts, enhanced production of rate-limiting enzymes, selection of appropriate promoter and ribosome binding sites, application of directed evolution of enzymes, and chassis re-circuit. Overall, these approaches tend to be specific for each engineering project rather than a systematic practice based on a more generalizable strategy. In this mini-review, we highlight some novel and extensive approaches and tools intended to address the improvement of a target product formation, founded in sophisticated principles such as dynamic control, pathway genes modularization, and flux modeling.

  18. Degeneracy: a design principle for achieving robustness and evolvability.

    PubMed

    Whitacre, James; Bender, Axel

    2010-03-07

    Robustness, the insensitivity of some of a biological system's functionalities to a set of distinct conditions, is intimately linked to fitness. Recent studies suggest that it may also play a vital role in enabling the evolution of species. Increasing robustness, so is proposed, can lead to the emergence of evolvability if evolution proceeds over a neutral network that extends far throughout the fitness landscape. Here, we show that the design principles used to achieve robustness dramatically influence whether robustness leads to evolvability. In simulation experiments, we find that purely redundant systems have remarkably low evolvability while degenerate, i.e. partially redundant, systems tend to be orders of magnitude more evolvable. Surprisingly, the magnitude of observed variation in evolvability can neither be explained by differences in the size nor the topology of the neutral networks. This suggests that degeneracy, a ubiquitous characteristic in biological systems, may be an important enabler of natural evolution. More generally, our study provides valuable new clues about the origin of innovations in complex adaptive systems. 2009 Elsevier Ltd. All rights reserved.

  19. Design principles in the development of (public) health information infrastructures.

    PubMed

    Neame, Roderick

    2012-01-01

    In this article the author outlines the key issues in the development of a regional health information infrastructure suitable for public health data collections. A set of 10 basic design and development principles as used and validated in the development of the successful New Zealand National Health Information Infrastructure in 1993 are put forward as a basis for future developments. The article emphasises the importance of securing clinical input into any health data that is collected, and suggests strategies whereby this may be achieved, including creating an information economy alongside the care economy. It is suggested that the role of government in such developments is to demonstrate leadership, to work with the sector to develop data, messaging and security standards, to establish key online indexes, to develop data warehouses and to create financial incentives for adoption of the infrastructure and the services it delivers to users. However experience suggests that government should refrain from getting involved in local care services data infrastructure, technology and management issues.

  20. ACTIVE Louisville: incorporating active living principles into planning and design.

    PubMed

    Walfoort, Nina L; Clark, Jennifer J; Bostock, Marigny J; O'Neil, Kathleen

    2009-12-01

    ACTIVE Louisville was a collaboration working to introduce active living principles into a downtown redevelopment planning and design process, in order to create more vibrant neighborhoods where residents incorporate healthy habits into daily routines. ACTIVE Louisville worked to increase physical activity and health awareness in three low-income neighborhoods undergoing redevelopment related to the replacement of a public housing project with a new, mixed-income community under a federal HOPE VI grant. Working with local planners, neighborhood groups, community organizers, and housing officials, ACTIVE Louisville helped expand physical activity awareness and opportunities. ACTIVE Louisville leveraged limited funding to accomplish an ambitious work program and to generate resources through creative collaborations that influenced policy and practices. ACTIVE Louisville had a considerable impact on the design of the HOPE VI project, the mission of a local community center, and the approach of the Mayor's Healthy Hometown Movement of the Louisville Metro Department of Public Health and Wellness. Introducing healthy lifestyles to communities with high levels of inactivity requires an interdisciplinary approach that will have an enduring effect only if it is absorbed into policies and practices of local institutions. ACTIVE Louisville's association with the Louisville Metro Housing Authority and the housing authority's high-profile housing redevelopment project amplified ACTIVE Louisville's impact. ACTIVE Louisville's public health interventions were well timed: physical improvements were underway in its target neighborhoods, and ACTIVE Louisville was able to coordinate with and have influence on the community and government groups that were involved in the HOPE VI project and related neighborhood redevelopment.

  1. Integrating bioinformatics into senior high school: design principles and implications.

    PubMed

    Machluf, Yossy; Yarden, Anat

    2013-09-01

    Bioinformatics is an integral part of modern life sciences. It has revolutionized and redefined how research is carried out and has had an enormous impact on biotechnology, medicine, agriculture and related areas. Yet, it is only rarely integrated into high school teaching and learning programs, playing almost no role in preparing the next generation of information-oriented citizens. Here, we describe the design principles of bioinformatics learning environments, including our own, that are aimed at introducing bioinformatics into senior high school curricula through engaging learners in scientifically authentic inquiry activities. We discuss the bioinformatics-related benefits and challenges that high school teachers and students face in the course of the implementation process, in light of previous studies and our own experience. Based on these lessons, we present a new approach for characterizing the questions embedded in bioinformatics teaching and learning units, based on three criteria: the type of domain-specific knowledge required to answer each question (declarative knowledge, procedural knowledge, strategic knowledge, situational knowledge), the scientific approach from which each question stems (biological, bioinformatics, a combination of the two) and the associated cognitive process dimension (remember, understand, apply, analyze, evaluate, create). We demonstrate the feasibility of this approach using a learning environment, which we developed for the high school level, and suggest some of its implications. This review sheds light on unique and critical characteristics related to broader integration of bioinformatics in secondary education, which are also relevant to the undergraduate level, and especially on curriculum design, development of suitable learning environments and teaching and learning processes.

  2. Evolutionary Design and Prototyping of Single Crystalline Titanium Nitride Lattice Optics (Postprint)

    DTIC Science & Technology

    2017-01-17

    balanced intensities at the light spots. We also demonstrated a simple, efficient technique to prototype these lattice designs in large-area TiN...evolutionary algorithm with a multiobjective fitness function was developed to produce a variety of three- dimensional (3D) light profiles with balanced ...prototype technique. Figure 2. Calculations using the inverse fitness function can produce balanced intensity at all light points. Schemes of lattice

  3. Dynamic sealing principles. [design configurations for fluid leakage control

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamental principles governing dynamic sealing operation are discussed. Different seals are described in terms of these principles. Despite the large variety of detailed construction, there appear to be some basic principles, or combinations of basic principles, by which all seals function. They are: (1) selection and control of seal geometry, (2) control of leakage fluid properties, and (3) control of forces acting on leakage fluids. Theoretical and practical considerations in the application of these principles are discussed. Advantages, disadvantages, limitations, and application examples of various conventional and special seals are presented. Fundamental equations governing liquid and gas flows in thin-film seals, which enable leakage calculations to be made, are also presented.

  4. School Building Designs: Principles and Challenges of the 21st Century.

    ERIC Educational Resources Information Center

    Chan, T. C.

    2002-01-01

    Reviews school-facility challenges and design principles described in 2000 U.S. Department of Education report on school planning and design. Describes additional school-facility design challenges and planning principles. Describes five critical facility-planning issues for the 21st Century. (Contains 14 references.) (PKP)

  5. Effective Principles in Designing E-Course in Light of Learning Theories

    ERIC Educational Resources Information Center

    Afifi, Muhammad K.; Alamri, Saad S.

    2014-01-01

    The researchers conducted an exploratory study to determine the design quality of some E-courses delivered via the web to a number of colleagues at the university. Results revealed a number of shortcomings in the design of these courses, mostly due to the absence of effective principles in the design of these E-courses, especially principles of…

  6. [In Silico Drug Design Using an Evolutionary Algorithm and Compound Database].

    PubMed

    Kawai, Kentaro; Takahashi, Yoshimasa

    2016-01-01

      Computational drug design plays an important role in the discovery of new drugs. Recently, we proposed an algorithm for designing new drug-like molecules utilizing the structure of a known active molecule. To design molecules, three types of fragments (ring, linker, and side-chain fragments) were defined as building blocks, and a fragment library was prepared from molecules listed in G protein-coupled receptor (GPCR)-SARfari database. An evolutionary algorithm which executes evolutionary operations, such as crossover, mutation, and selection, was implemented to evolve the molecules. As a case study, some GPCRs were selected for computational experiments in which we tried to design ligands from simple seed fragments using the Tanimoto coefficient as a fitness function. The results showed that the algorithm could be used successfully to design new molecules with structural similarity, scaffold variety, and chemical validity. In addition, a docking study revealed that these designed molecules also exhibited shape complementarity with the binding site of the target protein. Therefore, this is expected to become a powerful tool for designing new drug-like molecules in drug discovery projects.

  7. Measuring, Enabling and Comparing Modularity, Regularity and Hierarchy in Evolutionary Design

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2005-01-01

    For computer-automated design systems to scale to complex designs they must be able to produce designs that exhibit the characteristics of modularity, regularity and hierarchy - characteristics that are found both in man-made and natural designs. Here we claim that these characteristics are enabled by implementing the attributes of combination, control-flow and abstraction in the representation. To support this claim we use an evolutionary algorithm to evolve solutions to different sizes of a table design problem using five different representations, each with different combinations of modularity, regularity and hierarchy enabled and show that the best performance happens when all three of these attributes are enabled. We also define metrics for modularity, regularity and hierarchy in design encodings and demonstrate that high fitness values are achieved with high values of modularity, regularity and hierarchy and that there is a positive correlation between increases in fitness and increases in modularity. regularity and hierarchy.

  8. Design principles for robust vesiculation in clathrin-mediated endocytosis

    PubMed Central

    Hassinger, Julian E.; Oster, George; Drubin, David G.; Rangamani, Padmini

    2017-01-01

    A critical step in cellular-trafficking pathways is the budding of membranes by protein coats, which recent experiments have demonstrated can be inhibited by elevated membrane tension. The robustness of processes like clathrin-mediated endocytosis (CME) across a diverse range of organisms and mechanical environments suggests that the protein machinery in this process has evolved to take advantage of some set of physical design principles to ensure robust vesiculation against opposing forces like membrane tension. Using a theoretical model for membrane mechanics and membrane protein interaction, we have systematically investigated the influence of membrane rigidity, curvature induced by the protein coat, area covered by the protein coat, membrane tension, and force from actin polymerization on bud formation. Under low tension, the membrane smoothly evolves from a flat to budded morphology as the coat area or spontaneous curvature increases, whereas the membrane remains essentially flat at high tensions. At intermediate, physiologically relevant, tensions, the membrane undergoes a “snap-through instability” in which small changes in the coat area, spontaneous curvature or membrane tension cause the membrane to “snap” from an open, U-shape to a closed bud. This instability can be smoothed out by increasing the bending rigidity of the coat, allowing for successful budding at higher membrane tensions. Additionally, applied force from actin polymerization can bypass the instability by inducing a smooth transition from an open to a closed bud. Finally, a combination of increased coat rigidity and force from actin polymerization enables robust vesiculation even at high membrane tensions. PMID:28126722

  9. Design of acoustic metamaterials using the covariance matrix adaptation evolutionary strategy

    NASA Astrophysics Data System (ADS)

    Huang, Bei; Cheng, Qiang; Song, Gang Yong; Cui, Tie Jun

    2017-03-01

    Acoustic metamaterials can manipulate sound waves in surprising ways, including the focusing, cloaking, and extraordinary transmitting of sound waves. With the increasing requirements for acoustic metamaterials with extreme parameters, we propose the design of acoustic meta-atoms with a large refraction index using the covariance matrix adaptation evolutionary optimization strategy. To validate the procedure, we propose an optimized metamaterial to construct an acoustic deflection lens. The full-wave simulation results are consistent with the theoretical predictions, showing the efficacy and accuracy of the proposed method, and indicating that the optimization algorithm is a powerful tool for designing meta-atoms with excellent applications.

  10. Seat design principles to reduce neck injuries in rear impacts.

    PubMed

    Viano, David C

    2008-12-01

    In the 1990s, research was conducted at General Motors R&D Center on seat safety in rear impacts. It led to the development of high retention seats and an active head restraint to improve occupant safety. This article provides an overview of the design principles found from that research and focuses on seat characteristics that lower whiplash risks. Sled and quasistatic seat testing showed how occupants interact with the seat in rear impacts and what seat characteristics improve occupant retention, energy management, and support of the head-neck, lowering injury risks. Neck displacements, moments, and forces were used to assess whiplash and more severe injury risks. A QST test was developed to quasi-statically push a dummy rearward into the seat to determine seat stiffness (k), frame strength (j), and peak bending moment (M(Hpt)). These parameters were related to neck displacements associated with whiplash. Sled tests were run with in-position and out-of-position male and female Hybrid III dummies to assess performance. A high retention seat and active head restraint were developed and put into production in 1997. High retention seats have 2.3 times greater moment, develop 2.2 times greater load, but have the same stiffness as earlier yielding seats. Seat stiffness was found to be a principle characteristic related to neck displacements associated with whiplash. The combination of a stronger frame, yielding seatback, and high-forward head restraint in the high retention seat provides early head support and low neck displacements in rear impacts. Larger reductions in neck displacement were obtained by adding an active head restraint that moves the head restraint forward and upward by occupant penetration into the seatback. This substantially reduces head contact time, neck displacements, and loads. Whiplash risks are related to seat stiffness, the position of the head restraint, and frame strength. Low seat stiffness allows the occupant to move into the seatback

  11. Contact mechanisms and design principles for Schottky contacts to group-III nitrides

    NASA Astrophysics Data System (ADS)

    Mohammad, S. Noor

    2005-03-01

    Contact mechanisms and design principles for Schottky contacts to group-III nitrides have been studied. These contacts, made generally by using simple principles and past experiences, suffer from serious drawbacks. The importance of various parameters such as surface morphology, surface treatment, metal/semiconductor interactions at the interface, thermal stability, minimization of doping by metal deposition and etching, elimination of edge electric field, etc., for them has been thoroughly investigated. Several design principles have been proposed. Both theoretical and experimental data have been presented to justify the validity of the proposed contact mechanisms and design principles. While theoretical calculations provide fundamental physics underlying heavy doping, leakage, etc., the experimental data provide verification of the contact mechanisms and design principles. The proposed principles are general enough to be applicable to most, if not all, Schottky contacts.

  12. Design of Learning Objects for Concept Learning: Effects of Multimedia Learning Principles and an Instructional Approach

    ERIC Educational Resources Information Center

    Chiu, Thomas K. F.; Churchill, Daniel

    2016-01-01

    Literature suggests using multimedia learning principles in the design of instructional material. However, these principles may not be sufficient for the design of learning objects for concept learning in mathematics. This paper reports on an experimental study that investigated the effects of an instructional approach, which includes two teaching…

  13. Design of Learning Objects for Concept Learning: Effects of Multimedia Learning Principles and an Instructional Approach

    ERIC Educational Resources Information Center

    Chiu, Thomas K. F.; Churchill, Daniel

    2016-01-01

    Literature suggests using multimedia learning principles in the design of instructional material. However, these principles may not be sufficient for the design of learning objects for concept learning in mathematics. This paper reports on an experimental study that investigated the effects of an instructional approach, which includes two teaching…

  14. Representing Clarity: Using Universal Design Principles to Create Effective Hybrid Course Learning Materials

    ERIC Educational Resources Information Center

    Spiegel, Cheri Lemieux

    2012-01-01

    This article describes how the author applied principles of universal design to hybrid course materials to increase student understanding and, ultimately, success. Pulling the three principles of universal design--consistency, color, and icon representation--into the author's Blackboard course allowed her to change the types of reading skills…

  15. Representing Clarity: Using Universal Design Principles to Create Effective Hybrid Course Learning Materials

    ERIC Educational Resources Information Center

    Spiegel, Cheri Lemieux

    2012-01-01

    This article describes how the author applied principles of universal design to hybrid course materials to increase student understanding and, ultimately, success. Pulling the three principles of universal design--consistency, color, and icon representation--into the author's Blackboard course allowed her to change the types of reading skills…

  16. Integrating Quality Matters into Hybrid Course Design: A Principles of Marketing Case Study

    ERIC Educational Resources Information Center

    Young, Mark R.

    2014-01-01

    Previous research supports the idea that the success of hybrid or online delivery modes is more a function of course design than delivery media. This article describes a case study of a hybrid Principles of Marketing course that implemented a comprehensive redesign based on design principles espoused by the Quality Matters Program, a center for…

  17. Designing Novel Health ICTs to Support Work, Not Generate It: Five Principles.

    PubMed

    Peddie, David; Small, Serena; Wickham, Maeve; Bailey, Chantelle; Hohl, Corinne; Balka, Ellen

    2017-01-01

    In this paper, we offer five principles to inform how health ICT designers and healthcare organizations address and mitigate issues relating to clinician documentation burden. We draw on our experience and empirical work designing an ICT intervention, ActionADE, to illustrate how our team developed and will use these principles to ease documentation burden for clinician-users.

  18. Guiding Principles for Designing and Growing a Campus Network for the Future.

    ERIC Educational Resources Information Center

    Long, Philip E.

    2000-01-01

    Offers guidelines to help colleges and universities ensure a course of telecommunications network growth and renewal, provide continuous network upgrades, and maintain a position of flexibility. Discusses focuses on principles that guide network planning and design; how to apply principles to standard building blocks and network design; voice,…

  19. Integrating Quality Matters into Hybrid Course Design: A Principles of Marketing Case Study

    ERIC Educational Resources Information Center

    Young, Mark R.

    2014-01-01

    Previous research supports the idea that the success of hybrid or online delivery modes is more a function of course design than delivery media. This article describes a case study of a hybrid Principles of Marketing course that implemented a comprehensive redesign based on design principles espoused by the Quality Matters Program, a center for…

  20. The Design and Transformation of Biofundamentals: A Nonsurvey Introductory Evolutionary and Molecular Biology Course.

    PubMed

    Klymkowsky, Michael W; Rentsch, Jeremy D; Begovic, Emina; Cooper, Melanie M

    2016-01-01

    Many introductory biology courses amount to superficial surveys of disconnected topics. Often, foundational observations and the concepts derived from them and students' ability to use these ideas appropriately are overlooked, leading to unrealistic expectations and unrecognized learning obstacles. The result can be a focus on memorization at the expense of the development of a meaningful framework within which to consider biological phenomena. About a decade ago, we began a reconsideration of what an introductory course should present to students and the skills they need to master. The original Web-based course's design presaged many of the recommendations of the Vision and Change report; in particular, a focus on social evolutionary mechanisms, stochastic (evolutionary and molecular) processes, and core ideas (cellular continuity, evolutionary homology, molecular interactions, coupled chemical reactions, and molecular machines). Inspired by insights from the Chemistry, Life, the Universe & Everything general chemistry project, we transformed the original Web version into a (freely available) book with a more unified narrative flow and a set of formative assessments delivered through the beSocratic system. We outline how student responses to course materials are guiding future course modifications, in particular a more concerted effort at helping students to construct logical, empirically based arguments, explanations, and models.

  1. The Design and Transformation of Biofundamentals: A Nonsurvey Introductory Evolutionary and Molecular Biology Course

    PubMed Central

    Klymkowsky, Michael W.; Rentsch, Jeremy D.; Begovic, Emina; Cooper, Melanie M.

    2016-01-01

    Many introductory biology courses amount to superficial surveys of disconnected topics. Often, foundational observations and the concepts derived from them and students’ ability to use these ideas appropriately are overlooked, leading to unrealistic expectations and unrecognized learning obstacles. The result can be a focus on memorization at the expense of the development of a meaningful framework within which to consider biological phenomena. About a decade ago, we began a reconsideration of what an introductory course should present to students and the skills they need to master. The original Web-based course’s design presaged many of the recommendations of the Vision and Change report; in particular, a focus on social evolutionary mechanisms, stochastic (evolutionary and molecular) processes, and core ideas (cellular continuity, evolutionary homology, molecular interactions, coupled chemical reactions, and molecular machines). Inspired by insights from the Chemistry, Life, the Universe & Everything general chemistry project, we transformed the original Web version into a (freely available) book with a more unified narrative flow and a set of formative assessments delivered through the beSocratic system. We outline how student responses to course materials are guiding future course modifications, in particular a more concerted effort at helping students to construct logical, empirically based arguments, explanations, and models. PMID:27909020

  2. Integrated Controls-Structures Design Methodology: Redesign of an Evolutionary Test Structure

    NASA Technical Reports Server (NTRS)

    Maghami, Peiman G.; Gupta, Sandeep; Elliot, Kenny B.; Joshi, Suresh M.

    1997-01-01

    An optimization-based integrated controls-structures design methodology for a class of flexible space structures is described, and the phase-0 Controls-Structures-Integration evolutionary model, a laboratory testbed at NASA Langley, is redesigned using this integrated design methodology. The integrated controls-structures design is posed as a nonlinear programming problem to minimize the control effort required to maintain a specified line-of-sight pointing performance, under persistent white noise disturbance. Static and dynamic dissipative control strategies are employed for feedback control, and parameters of these controllers are considered as the control design variables. Sizes of strut elements in various sections of the CEM are used as the structural design variables. Design guides for the struts are developed and employed in the integrated design process, to ensure that the redesigned structure can be effectively fabricated. The superiority of the integrated design methodology over the conventional design approach is demonstrated analytically by observing a significant reduction in the average control power needed to maintain specified pointing performance with the integrated design approach.

  3. Science Curricula Design: Analysis of Authors' Ideological and Pedagogical Principles

    ERIC Educational Resources Information Center

    Ferreira, Silvia; Morais, Ana M.; Neves, Isabel P.

    2011-01-01

    The study analyses the extent to which the sociological message transmitted by the Official Pedagogic Discourse of the curriculum for Portuguese middle schools contains the ideological and pedagogical principles of its authors. The research is epistemologically and sociologically grounded, placing particular emphasis on Bernstein theory of…

  4. Design Principles for the Development of the Balanced Scorecard

    ERIC Educational Resources Information Center

    Keser Ozmantar, Zehra; Gedikoglu, Tokay

    2016-01-01

    Purpose: The purpose of this paper is to investigate the development and implementation process of the balanced scorecard (BSC) approach in an educational institution in the context of the Turkish educational system. It also aims, on the basis of the results of the applications in a particular school, to define principles through which the…

  5. Design Principles for the Development of the Balanced Scorecard

    ERIC Educational Resources Information Center

    Keser Ozmantar, Zehra; Gedikoglu, Tokay

    2016-01-01

    Purpose: The purpose of this paper is to investigate the development and implementation process of the balanced scorecard (BSC) approach in an educational institution in the context of the Turkish educational system. It also aims, on the basis of the results of the applications in a particular school, to define principles through which the…

  6. Design principles for data- and change-oriented organisational analysis in workplace health promotion.

    PubMed

    Inauen, A; Jenny, G J; Bauer, G F

    2012-06-01

    This article focuses on organizational analysis in workplace health promotion (WHP) projects. It shows how this analysis can be designed such that it provides rational data relevant to the further context-specific and goal-oriented planning of WHP and equally supports individual and organizational change processes implied by WHP. Design principles for organizational analysis were developed on the basis of a narrative review of the guiding principles of WHP interventions and organizational change as well as the scientific principles of data collection. Further, the practical experience of WHP consultants who routinely conduct organizational analysis was considered. This resulted in a framework with data-oriented and change-oriented design principles, addressing the following elements of organizational analysis in WHP: planning the overall procedure, data content, data-collection methods and information processing. Overall, the data-oriented design principles aim to produce valid, reliable and representative data, whereas the change-oriented design principles aim to promote motivation, coherence and a capacity for self-analysis. We expect that the simultaneous consideration of data- and change-oriented design principles for organizational analysis will strongly support the WHP process. We finally illustrate the applicability of the design principles to health promotion within a WHP case study.

  7. Evolutionary computing for the design search and optimization of space vehicle power subsystems

    NASA Technical Reports Server (NTRS)

    Kordon, Mark; Klimeck, Gerhard; Hanks, David; Hua, Hook

    2004-01-01

    Evolutionary computing has proven to be a straightforward and robust approach for optimizing a wide range of difficult analysis and design problems. This paper discusses the application of these techniques to an existing space vehicle power subsystem resource and performance analysis simulation in a parallel processing environment. Out preliminary results demonstrate that this approach has the potential to improve the space system trade study process by allowing engineers to statistically weight subsystem goals of mass, cost and performance then automatically size power elements based on anticipated performance of the subsystem rather than on worst-case estimates.

  8. The Langley Research Center CSI phase-0 evolutionary model testbed-design and experimental results

    NASA Technical Reports Server (NTRS)

    Belvin, W. K.; Horta, Lucas G.; Elliott, K. B.

    1991-01-01

    A testbed for the development of Controls Structures Interaction (CSI) technology is described. The design philosophy, capabilities, and early experimental results are presented to introduce some of the ongoing CSI research at NASA-Langley. The testbed, referred to as the Phase 0 version of the CSI Evolutionary model (CEM), is the first stage of model complexity designed to show the benefits of CSI technology and to identify weaknesses in current capabilities. Early closed loop test results have shown non-model based controllers can provide an order of magnitude increase in damping in the first few flexible vibration modes. Model based controllers for higher performance will need to be robust to model uncertainty as verified by System ID tests. Data are presented that show finite element model predictions of frequency differ from those obtained from tests. Plans are also presented for evolution of the CEM to study integrated controller and structure design as well as multiple payload dynamics.

  9. Universal Design in Postsecondary Education: Process, Principles, and Applications

    ERIC Educational Resources Information Center

    Burgstahler, Sheryl

    2009-01-01

    Designing any product or environment involves the consideration of many factors, including aesthetics, engineering options, environmental issues, safety concerns, industry standards, and cost. Typically, designers focus their attention on the average user. In contrast, universal design (UD), according to the Center for Universal Design, "is…

  10. Principles of thermal design with nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Fumeron, S.; Pereira, E.; Moraes, F.

    2014-02-01

    Highly engineered materials are arousing great interest because of their ability to manipulate heat, as described by the coordinate transformation approach. Based on recently developed analog gravity models, we present how a simple device based on nematic liquid crystals can achieve in principle either thermal concentration or expulsion. These outcomes are shown to stem from the topological properties of a disclination-like structure, induced in the nematic phase by anchoring conditions.

  11. Some General Principles in Cryogenic Design, Implementation, and Testing

    NASA Technical Reports Server (NTRS)

    Dipirro, Michael James

    2015-01-01

    Brief Course Description: In 2 hours only the most basic principles of cryogenics can be presented. I will concentrate on the differences between a room temperature thermal analysis and cryogenic thermal analysis, namely temperature dependent properties. I will talk about practical materials for thermal contact and isolation. I will finish by describing the verification process and instrumentation used that is unique to cryogenic (in general less than 100K) systems.

  12. Developing Multiple Diverse Potential Designs for Heat Transfer Utilizing Graph Based Evolutionary Algorithms

    SciTech Connect

    David J. Muth Jr.

    2006-09-01

    This paper examines the use of graph based evolutionary algorithms (GBEAs) to find multiple acceptable solutions for heat transfer in engineering systems during the optimization process. GBEAs are a type of evolutionary algorithm (EA) in which a topology, or geography, is imposed on an evolving population of solutions. The rates at which solutions can spread within the population are controlled by the choice of topology. As in nature geography can be used to develop and sustain diversity within the solution population. Altering the choice of graph can create a more or less diverse population of potential solutions. The choice of graph can also affect the convergence rate for the EA and the number of mating events required for convergence. The engineering system examined in this paper is a biomass fueled cookstove used in developing nations for household cooking. In this cookstove wood is combusted in a small combustion chamber and the resulting hot gases are utilized to heat the stove’s cooking surface. The spatial temperature profile of the cooking surface is determined by a series of baffles that direct the flow of hot gases. The optimization goal is to find baffle configurations that provide an even temperature distribution on the cooking surface. Often in engineering, the goal of optimization is not to find the single optimum solution but rather to identify a number of good solutions that can be used as a starting point for detailed engineering design. Because of this a key aspect of evolutionary optimization is the diversity of the solutions found. The key conclusion in this paper is that GBEA’s can be used to create multiple good solutions needed to support engineering design.

  13. Design Optimization of an Axial Fan Blade Through Multi-Objective Evolutionary Algorithm

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Hyuk; Choi, Jae-Ho; Husain, Afzal; Kim, Kwang-Yong

    2010-06-01

    This paper presents design optimization of an axial fan blade with hybrid multi-objective evolutionary algorithm (hybrid MOEA). Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model are discretized by the finite volume approximations and solved on hexahedral grids for the flow analyses. The validation of the numerical results was performed with the experimental data for the axial and tangential velocities. Six design variables related to the blade lean angle and blade profile are selected and the Latin hypercube sampling of design of experiments is used to generate design points within the selected design space. Two objective functions namely total efficiency and torque are employed and the multi-objective optimization is carried out to enhance total efficiency and to reduce the torque. The flow analyses are performed numerically at the designed points to obtain values of the objective functions. The Non-dominated Sorting of Genetic Algorithm (NSGA-II) with ɛ -constraint strategy for local search coupled with surrogate model is used for multi-objective optimization. The Pareto-optimal solutions are presented and trade-off analysis is performed between the two competing objectives in view of the design and flow constraints. It is observed that total efficiency is enhanced and torque is decreased as compared to the reference design by the process of multi-objective optimization. The Pareto-optimal solutions are analyzed to understand the mechanism of the improvement in the total efficiency and reduction in torque.

  14. Neural-Network-Biased Genetic Algorithms for Materials Design: Evolutionary Algorithms That Learn.

    PubMed

    Patra, Tarak K; Meenakshisundaram, Venkatesh; Hung, Jui-Hsiang; Simmons, David S

    2017-02-13

    Machine learning has the potential to dramatically accelerate high-throughput approaches to materials design, as demonstrated by successes in biomolecular design and hard materials design. However, in the search for new soft materials exhibiting properties and performance beyond those previously achieved, machine learning approaches are frequently limited by two shortcomings. First, because they are intrinsically interpolative, they are better suited to the optimization of properties within the known range of accessible behavior than to the discovery of new materials with extremal behavior. Second, they require large pre-existing data sets, which are frequently unavailable and prohibitively expensive to produce. Here we describe a new strategy, the neural-network-biased genetic algorithm (NBGA), for combining genetic algorithms, machine learning, and high-throughput computation or experiment to discover materials with extremal properties in the absence of pre-existing data. Within this strategy, predictions from a progressively constructed artificial neural network are employed to bias the evolution of a genetic algorithm, with fitness evaluations performed via direct simulation or experiment. In effect, this strategy gives the evolutionary algorithm the ability to "learn" and draw inferences from its experience to accelerate the evolutionary process. We test this algorithm against several standard optimization problems and polymer design problems and demonstrate that it matches and typically exceeds the efficiency and reproducibility of standard approaches including a direct-evaluation genetic algorithm and a neural-network-evaluated genetic algorithm. The success of this algorithm in a range of test problems indicates that the NBGA provides a robust strategy for employing informatics-accelerated high-throughput methods to accelerate materials design in the absence of pre-existing data.

  15. Universal Design in Higher Education: From Principles to Practice

    ERIC Educational Resources Information Center

    Burgstahler, Sheryl E., Ed.; Cory, Rebecca C., Ed.

    2008-01-01

    "Universal Design in Higher Education" looks at the design of physical and technological environments at institutions of higher education; at issues pertaining to curriculum and instruction; and at the full array of student services. "Universal Design in Higher Education" is a comprehensive guide for researchers and…

  16. Universal Design in Higher Education: From Principles to Practice

    ERIC Educational Resources Information Center

    Burgstahler, Sheryl E., Ed.; Cory, Rebecca C., Ed.

    2008-01-01

    "Universal Design in Higher Education" looks at the design of physical and technological environments at institutions of higher education; at issues pertaining to curriculum and instruction; and at the full array of student services. "Universal Design in Higher Education" is a comprehensive guide for researchers and…

  17. Study Design in fMRI: Basic Principles

    ERIC Educational Resources Information Center

    Amaro, Edson, Jr.; Barker, Gareth J.

    2006-01-01

    There is a wide range of functional magnetic resonance imaging (fMRI) study designs available for the neuroscientist who wants to investigate cognition. In this manuscript we review some aspects of fMRI study design, including cognitive comparison strategies (factorial, parametric designs), and stimulus presentation possibilities (block,…

  18. Principles for Predicting RNA Secondary Structure Design Difficulty.

    PubMed

    Anderson-Lee, Jeff; Fisker, Eli; Kosaraju, Vineet; Wu, Michelle; Kong, Justin; Lee, Jeehyung; Lee, Minjae; Zada, Mathew; Treuille, Adrien; Das, Rhiju

    2016-02-27

    Designing RNAs that form specific secondary structures is enabling better understanding and control of living systems through RNA-guided silencing, genome editing and protein organization. Little is known, however, about which RNA secondary structures might be tractable for downstream sequence design, increasing the time and expense of design efforts due to inefficient secondary structure choices. Here, we present insights into specific structural features that increase the difficulty of finding sequences that fold into a target RNA secondary structure, summarizing the design efforts of tens of thousands of human participants and three automated algorithms (RNAInverse, INFO-RNA and RNA-SSD) in the Eterna massive open laboratory. Subsequent tests through three independent RNA design algorithms (NUPACK, DSS-Opt and MODENA) confirmed the hypothesized importance of several features in determining design difficulty, including sequence length, mean stem length, symmetry and specific difficult-to-design motifs such as zigzags. Based on these results, we have compiled an Eterna100 benchmark of 100 secondary structure design challenges that span a large range in design difficulty to help test future efforts. Our in silico results suggest new routes for improving computational RNA design methods and for extending these insights to assess "designability" of single RNA structures, as well as of switches for in vitro and in vivo applications.

  19. EvoDesign: De novo protein design based on structural and evolutionary profiles.

    PubMed

    Mitra, Pralay; Shultis, David; Zhang, Yang

    2013-07-01

    Protein design aims to identify new protein sequences of desirable structure and biological function. Most current de novo protein design methods rely on physics-based force fields to search for low free-energy states following Anfinsen's thermodynamic hypothesis. A major obstacle of such approaches is the inaccuracy of the force field design, which cannot accurately describe the atomic interactions or distinguish correct folds. We developed a new web server, EvoDesign, to design optimal protein sequences of given scaffolds along with multiple sequence and structure-based features to assess the foldability and goodness of the designs. EvoDesign uses an evolution-profile-based Monte Carlo search with the profiles constructed from homologous structure families in the Protein Data Bank. A set of local structure features, including secondary structure, torsion angle and solvation, are predicted by single-sequence neural-network training and used to smooth the sequence motif and accommodate the physicochemical packing. The EvoDesign algorithm has been extensively tested in large-scale protein design experiments, which demonstrate enhanced foldability and structural stability of designed sequences compared with the physics-based designing methods. The EvoDesign server is freely available at http://zhanglab.ccmb.med.umich.edu/EvoDesign.

  20. New design principle for cryptographic modules in computer security systems

    SciTech Connect

    Moldovyan, A.A.; Moldovyan, N.A.

    1994-05-01

    The development of information technology is leading to the rapid replacement of paper storage and transmission of data by electronic means. The thorough penetration of electronics into data processing, storage, and transmission along with the appearance of local- and wide-area computer networks has made it necessary to standardize the principles and systems of information technology and their hardware. This simplifies information acquisition and complicates the legal protection of its confidentiality. Comprehensive information security is a fairly complicated task, which includes a set of legal, organizational, scientific, and engineering measures. Encryption is the most universal, convenient, and reliable method for ensuring data confidentiality.

  1. Design and Optimization of Low-thrust Orbit Transfers Using Q-law and Evolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon; vonAllmen, Paul; Fink, Wolfgang; Petropoulos, Anastassios; Terrile, Richard

    2005-01-01

    Future space missions will depend more on low-thrust propulsion (such as ion engines) thanks to its high specific impulse. Yet, the design of low-thrust trajectories is complex and challenging. Third-body perturbations often dominate the thrust, and a significant change to the orbit requires a long duration of thrust. In order to guide the early design phases, we have developed an efficient and efficacious method to obtain approximate propellant and flight-time requirements (i.e., the Pareto front) for orbit transfers. A search for the Pareto-optimal trajectories is done in two levels: optimal thrust angles and locations are determined by Q-law, while the Q-law is optimized with two evolutionary algorithms: a genetic algorithm and a simulated-annealing-related algorithm. The examples considered are several types of orbit transfers around the Earth and the asteroid Vesta.

  2. Design and Optimization of Low-thrust Orbit Transfers Using Q-law and Evolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon; vonAllmen, Paul; Fink, Wolfgang; Petropoulos, Anastassios; Terrile, Richard

    2005-01-01

    Future space missions will depend more on low-thrust propulsion (such as ion engines) thanks to its high specific impulse. Yet, the design of low-thrust trajectories is complex and challenging. Third-body perturbations often dominate the thrust, and a significant change to the orbit requires a long duration of thrust. In order to guide the early design phases, we have developed an efficient and efficacious method to obtain approximate propellant and flight-time requirements (i.e., the Pareto front) for orbit transfers. A search for the Pareto-optimal trajectories is done in two levels: optimal thrust angles and locations are determined by Q-law, while the Q-law is optimized with two evolutionary algorithms: a genetic algorithm and a simulated-annealing-related algorithm. The examples considered are several types of orbit transfers around the Earth and the asteroid Vesta.

  3. Applying an instance selection method to an evolutionary neural classifier design

    NASA Astrophysics Data System (ADS)

    Khritonenko, Dmitrii; Stanovov, Vladimir; Semenkin, Eugene

    2017-02-01

    In this paper the application of an instance selection algorithm to the design of a neural classifier is considered. A number of existing instance selection methods are presented. A new wrapper-method, whose main difference compared to other approaches is an iterative procedure for selecting training subsets from the dataset, is described. The approach is based on using training subsample selection probabilities for every instance. The value of these probabilities depends on the classification success for each measurement. An evolutionary algorithm for the design of a neural classifier is presented, which was used to test the efficiency of the presented approach. The described approach has been implemented and tested on a set of classification problems. The testing has shown that the presented algorithm allows the computational complexity to be decreased and the quality of the obtained classifiers to be increased. Compared to analogues found in scientific literature, it was shown that the presented algorithm is an effective tool for classification problem solving.

  4. Structure and stability of silicon nanoclusters passivated by hydrogen and oxygen: evolutionary algorithm and first- principles study

    NASA Astrophysics Data System (ADS)

    Baturin, V. S.; Lepeshkin, S. V.; Matsko, N. L.; Uspenskii, Yu A.

    2016-02-01

    We investigate the structural and thermodynamical properties of small silicon clusters. Using the graph theory applied to previously obtained structures of Si10H2m clusters we trace the connection between geometry and passivation degree. The existing data on these clusters and structures of Si10O4n clusters obtained here using evolutionary calculations allowed to analyze the features of Si10H2m clusters in hydrogen atmosphere and Si10O4n clusters in oxygen atmosphere. We have shown the basic differences between structures and thermodynamical properties of silicon clusters, passivated by hydrogen and silicon oxide clusters.

  5. Principles for predicting RNA secondary structure design difficulty

    PubMed Central

    Anderson-Lee, Jeff; Fisker, Eli; Kosaraju, Vineet; Wu, Michelle; Kong, Justin; Lee, Jeehyung; Lee, Minjae; Zada, Mathew; Treuille, Adrien; Das, Rhiju

    2015-01-01

    Designing RNAs that form specific secondary structures is enabling better understanding and control of living systems through RNA-guided silencing, genome editing and protein organization. Little is known, however, about which RNA secondary structures might be tractable for downstream sequence design, increasing the time and expense of design efforts due to inefficient secondary structure choices. Here, we present insights into specific structural features that increase the difficulty of finding sequences that fold into a target RNA secondary structure, summarizing the design efforts of tens of thousands of human participants and three automated algorithms (RNAInverse, INFO-RNA and RNA-SSD) in the Eterna massive open laboratory. Subsequent tests through three independent RNA design algorithms (NUPACK, DSS-Opt, MODENA) confirmed the hypothesized importance of several features in determining design difficulty, including sequence length, mean stem length, symmetry, and specific difficult-to-design motifs like zig-zags. Based on these results, we have compiled an Eterna100 benchmark of 100 secondary structure design challenges that span a large range in design difficulty to help test future efforts. Our in silico results suggest new routes for improving computational RNA design methods and for extending these insights to assessing “designability” of single RNA structures as well as of switches for in vitro and in vivo applications. PMID:26902426

  6. Friction reduction using discrete surface textures: principle and design

    NASA Astrophysics Data System (ADS)

    Hsu, Stephen M.; Jing, Yang; Hua, Diann; Zhang, Huan

    2014-08-01

    There have been many reports on the use of dimples, grooves, and other surface textures to control friction in sliding interfaces. The effectiveness of surface textures in friction reduction has been demonstrated in conformal contacts under high speed low load applications such as mechanical seals and automotive water pump seals, etc., resulting in reduced friction and longer durability. For sliding components with higher contact pressures or lower speeds, conflicting results were reported. Reasons for the inconsistency may be due to the differences in texture fabrication techniques, lack of dimple size and shape uniformity, and different tester used. This paper examines the basic principles on which surface textural patterns influence friction under the three principle lubrication regimes: hydrodynamic, elastohydrodynamic, and boundary lubrication regimes. Our findings suggest that each regime requires specific dimple size, shape, depth, and areal density to achieve friction reduction. Control experiments were also conducted to explore mechanisms of friction reduction. The dimple geometric shape and the dimple's orientation with respect to the sliding direction influence friction significantly. The underlying mechanisms for friction control via textures are discussed.

  7. Performance Assessment Design Principles Gleaned from Constructivist Learning Theory (Part 2)

    ERIC Educational Resources Information Center

    Zane, Thomas W.

    2009-01-01

    Just as objectivist theories have provided foundations for traditional tests, constructivist theories can offer foundations for performance assessment design and development methods. The tenets and principles embedded in various learning theories provide a solid foundation that can be combined with psychometric principles to help assessment…

  8. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Sustainable principles for siting, design and construction. 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.6 Sustainable principles...

  9. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Sustainable principles for siting, design and construction. 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.6 Sustainable principles...

  10. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Sustainable principles for siting, design and construction. 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.6 Sustainable principles...

  11. Using principles of learning to inform language therapy design for children with specific language impairment.

    PubMed

    Alt, Mary; Meyers, Christina; Ancharski, Alexandra

    2012-01-01

    Language treatment for children with specific language impairment (SLI) often takes months to achieve moderate results. Interventions often do not incorporate the principles that are known to affect learning in unimpaired learners. To outline some key findings about learning in typical populations and to suggest a model of how they might be applied to language treatment design as a catalyst for further research and discussion. Three main principles of implicit learning are reviewed: variability, complexity and sleep-dependent consolidation. After explaining these principles, evidence is provided as to how they influence learning tasks in unimpaired learners. Information is reviewed on principles of learning as they apply to impaired populations, current treatment designs are also reviewed that conform to the principles, and ways in which principles of learning might be incorporated into language treatment design are demonstrated. This paper provides an outline for how theoretical knowledge might be applied to clinical practice in an effort to promote discussion. Although the authors look forward to more specific details on how the principles of learning relate to impaired populations, there is ample evidence to suggest that these principles should be considered during treatment design. © 2012 Royal College of Speech and Language Therapists.

  12. Design Principles and Concepts for Enhancing Long-Term Cap Performance and Confidence

    SciTech Connect

    Steven J. Piet; Robert P. Breckenridge; Gregory J. White; Jacob J. Jacobson; Hilary I. Inyang

    2005-10-01

    The siting of new landfills is becoming increasing difficult as the public and stakeholders want more confidence of performance for longer times and landfill owners want to store more waste in the least area while knowing and limiting their long-term liabilities. These changes motivate re-examination of long-term performance mechanisms and their implications for cap and barrier designs. Accordingly, in this paper we first consider design principles from the standpoint of long-term performance and management, including the ability to monitor and repair barriers. We then consider some design concepts that may implement these principles, especially evapo-transpiration (ET) caps. We suggest five design principles based on experience in the cap and barrier field as well as other engineering disciplines. These principles are as follows: · Establish a clear and defendable design basis. · Design for ease of monitoring and repair. · Analyze the barrier as a dynamic system, not static. · Work with nature, not against. · Recognize that increased complexity can reduce, not enhance, net performance. ET caps are an excellent embodiment of these design principles. We apply the design principles to ET caps, as well as variants such as erosion armor, capillary breaks, bio-intrusion layers, and low permeability material layers.

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  14. Evolutionary patterns of metazoan microRNAs reveal targeting principles in the let-7 and miR-10 families

    PubMed Central

    Le, Hoai Huang Thi; Linse, Alexander; Godlove, Victoria A.; Nguyen, Thuy-Duyen; Kotagama, Kasuen; Lynch, Alissa; Rawls, Alan

    2017-01-01

    MicroRNAs (miRNAs) regulate gene output by targeting degenerate elements in mRNAs and have undergone drastic expansions in higher metazoan genomes. The evolutionary advantage of maintaining copies of highly similar miRNAs is not well understood, nor is it clear what unique functions, if any, miRNA family members possess. Here, we study evolutionary patterns of metazoan miRNAs, focusing on the targeting preferences of the let-7 and miR-10 families. These studies reveal hotspots for sequence evolution with implications for targeting and secondary structure. High-throughput screening for functional targets reveals that each miRNA represses sites with distinct features and regulates a large number of genes with cooperative function in regulatory networks. Unexpectedly, given the high degree of similarity, single-nucleotide changes grant miRNA family members with distinct targeting preferences. Together, our data suggest complex functional relationships among miRNA duplications, novel expression patterns, sequence change, and the acquisition of new targets. PMID:27927717

  15. Design principles in telescope development: invariance, innocence, and the costs

    NASA Astrophysics Data System (ADS)

    Steinbach, Manfred

    1997-03-01

    Instrument design is, for the most part, a battle against errors and costs. Passive methods of error damping are in many cases effective and inexpensive. This paper shows examples of error minimization in our design of telescopes, instrumentation and evaluation instruments.

  16. Resisting Technological Gravity: Using Guiding Principles for Instructional Design

    ERIC Educational Resources Information Center

    McDonald, Jason K.

    2010-01-01

    Instructional designers face tremendous pressure to abandon the essential characteristics of educational approaches, and settle instead for routine practices that do not preserve the level of quality those approaches originally expressed. Because this pressure can be strong enough to affect designers almost as gravity affects objects in the…

  17. Resisting Technological Gravity: Using Guiding Principles for Instructional Design

    ERIC Educational Resources Information Center

    McDonald, Jason K.

    2010-01-01

    Instructional designers face tremendous pressure to abandon the essential characteristics of educational approaches, and settle instead for routine practices that do not preserve the level of quality those approaches originally expressed. Because this pressure can be strong enough to affect designers almost as gravity affects objects in the…

  18. Modeling the allocation system: principles for robust design before restructuring.

    PubMed

    Mehrotra, Sanjay; Kilambi, Vikram; Gilroy, Richard; Ladner, Daniela P; Klintmalm, Goran B; Kaplan, Bruce

    2015-02-01

    The United Network for Organ Sharing is poised to resolve geographic disparity in liver transplantation and promote allocation based on medical urgency. At the time of writing, United Network for Organ Sharing is considering redistricting the organ procurement and transplantation network so that patient model for end-stage liver disease scores at transplant is more uniform across regions.We review the proposal with a systems-engineering focus and find that although the proposal is promising, it currently lacks evidence that it would perform effectively under realistic departures from its underlying data and assumptions. Moreover, we caution against prematurely focusing on redistricting as the only method to mitigate disparity. We describe system modeling principles which, if followed, will ensure that the redesigned allocation system is effective and efficient in achieving the intended goals.

  19. Design Principles of Length Control of Cytoskeletal Structures

    PubMed Central

    Mohapatra, Lishibanya; Goode, Bruce L.; Jelenkovic, Predrag; Phillips, Rob; Kondev, Jane

    2017-01-01

    Cells contain elaborate and interconnected networks of protein polymers, which make up the cytoskeleton. The cytoskeleton governs the internal positioning and movement of vesicles and organelles and controls dynamic changes in cell polarity, shape, and movement. Many of these processes require tight control of the size and shape of cytoskeletal structures, which is achieved despite rapid turnover of their molecular components. Here we review mechanisms by which cells control the size of filamentous cytoskeletal structures, from the point of view of simple quantitative models that take into account stochastic dynamics of their assembly and disassembly. Significantly, these models make experimentally testable predictions that distinguish different mechanisms of length control. Although the primary focus of this review is on cytoskeletal structures, we believe that the broader principles and mechanisms discussed herein will apply to a range of other subcellular structures whose sizes are tightly controlled and are linked to their functions. PMID:27145876

  20. Design and statistical principles of the SHIVA trial.

    PubMed

    Paoletti, Xavier; Asselain, Bernard; Kamal, Maud; Servant, Nicolas; Huppé, Philippe; Bieche, Ivan; Le Tourneau, Christophe

    2015-09-01

    Most molecularly targeted agents (MTAs) are expected to work in subgroups of cancer patients characterized by the presence of molecular alterations in the tumor cells. However, clinical development is generally carried out according to tumor type. The SHIVA randomized trial on the contrary has been set up to investigate which of tumor biology or tumor location and histology is the most important to select treatment in patients with cancer refractory to standard of care. Statistical principles, specificities, strengths and limitations of this trial that evaluates an omic-based algorithm to select the targeted agent are reviewed. In particular, the need for a randomized trial where the various steps to build the algorithm are explicitly described and standardized is emphasized. The impact of an algorithm that would be partly misspecified (i.e., that would lead to correct treatment selection for some tumor molecular profile but not for all) is quantified.

  1. Bio-inspired novel design principles for artificial molecular motors.

    PubMed

    Hugel, Thorsten; Lumme, Christina

    2010-10-01

    Since we have learned that biological organisms like ourselves are driven by tiny biological molecular motors we try to design and produce artificial molecular motors. However, despite the huge efforts since decades, man-made artificial molecular motors are still far from biological molecular motors or macroscopic motors with regard to performance, especially with respect to energy efficiency. This review highlights recent progress towards artificial molecular motors and discusses how their design and development can be guided by the design concepts of biological molecular motors or macroscopic motors.

  2. Mechanism Design Principle for Optical-Precision, Deployable Instruments

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Hachkowski, M. Roman

    2000-01-01

    The present paper is intended to be a guide for the design of 'microdynamically quiet' deployment mechanisms for optical-precision structures, such as deployable telescope mirrors and optical benches. Many of the guidelines included herein come directly from the field of optomechanical engineering, and are neither newly developed guidelines nor are they uniquely applicable to high-precision deployment mechanisms. However, the application of these guidelines to the design of deployment mechanisms is a rather new practice, so efforts are made herein to illustrate the process through the discussion of specific examples. The present paper summarizes a more extensive set of design guidelines for optical-precision mechanisms that are under development.

  3. Multi-criteria optimal pole assignment robust controller design for uncertainty systems using an evolutionary algorithm

    NASA Astrophysics Data System (ADS)

    Sarjaš, Andrej; Chowdhury, Amor; Svečko, Rajko

    2016-09-01

    This paper presents the synthesis of an optimal robust controller design using the polynomial pole placement technique and multi-criteria optimisation procedure via an evolutionary computation algorithm - differential evolution. The main idea of the design is to provide a reliable fixed-order robust controller structure and an efficient closed-loop performance with a preselected nominally characteristic polynomial. The multi-criteria objective functions have quasi-convex properties that significantly improve convergence and the regularity of the optimal/sub-optimal solution. The fundamental aim of the proposed design is to optimise those quasi-convex functions with fixed closed-loop characteristic polynomials, the properties of which are unrelated and hard to present within formal algebraic frameworks. The objective functions are derived from different closed-loop criteria, such as robustness with metric ?∞, time performance indexes, controller structures, stability properties, etc. Finally, the design results from the example verify the efficiency of the controller design and also indicate broader possibilities for different optimisation criteria and control structures.

  4. Design, analysis, and testing of the Phase 1 CSI Evolutionary Model erectable truss

    NASA Technical Reports Server (NTRS)

    Gronet, M. J.; Davis, D. A.; Kintis, D. H.; Brillhart, R. D.; Atkins, E. M.

    1992-01-01

    This report addressed the design, analysis, and testing of the erectable truss structure for the Phase 1 CSI Evolutionary Model (CEM) testbed. The Phase 1 CEM testbed is the second testbed to form part of an ongoing program of focused research at NASA/LaRC in the development of Controls-Structures Integration (CSI) technology. The Phase 1 CEM contains the same overall geometry, weight, and sensor locations as the Phase 0 CEM, but is based in an integrated controller and structure design, whereby both structure and controller design variables are sized simultaneously. The Phase 1 CEM design features seven truss sections composed of struts with tailored mass and stiffness properties. A common erectable joint is used and the strut stiffness is tailored by varying the cross-sectional area. To characterize the structure, static tests were conducted on individual struts and 10-bay truss assemblies. Dynamic tests were conducted on 10-bay truss assemblies as well as the fully-assembled CEM truss. The results indicate that the static and dynamic properties of the structure are predictable, well-characterized, and within the performance requirements established during the Phase 1 CEM integrated controller/structure design analysis.

  5. Principles of Experimental Design for Big Data Analysis

    PubMed Central

    Drovandi, Christopher C; Holmes, Christopher; McGree, James M; Mengersen, Kerrie; Richardson, Sylvia; Ryan, Elizabeth G

    2016-01-01

    Big Datasets are endemic, but are often notoriously difficult to analyse because of their size, heterogeneity and quality. The purpose of this paper is to open a discourse on the potential for modern decision theoretic optimal experimental design methods, which by their very nature have traditionally been applied prospectively, to improve the analysis of Big Data through retrospective designed sampling in order to answer particular questions of interest. By appealing to a range of examples, it is suggested that this perspective on Big Data modelling and analysis has the potential for wide generality and advantageous inferential and computational properties. We highlight current hurdles and open research questions surrounding efficient computational optimisation in using retrospective designs, and in part this paper is a call to the optimisation and experimental design communities to work together in the field of Big Data analysis. PMID:28883686

  6. Principles of Experimental Design for Big Data Analysis.

    PubMed

    Drovandi, Christopher C; Holmes, Christopher; McGree, James M; Mengersen, Kerrie; Richardson, Sylvia; Ryan, Elizabeth G

    2017-08-01

    Big Datasets are endemic, but are often notoriously difficult to analyse because of their size, heterogeneity and quality. The purpose of this paper is to open a discourse on the potential for modern decision theoretic optimal experimental design methods, which by their very nature have traditionally been applied prospectively, to improve the analysis of Big Data through retrospective designed sampling in order to answer particular questions of interest. By appealing to a range of examples, it is suggested that this perspective on Big Data modelling and analysis has the potential for wide generality and advantageous inferential and computational properties. We highlight current hurdles and open research questions surrounding efficient computational optimisation in using retrospective designs, and in part this paper is a call to the optimisation and experimental design communities to work together in the field of Big Data analysis.

  7. Execution Of Systems Integration Principles During Systems Engineering Design

    DTIC Science & Technology

    2016-09-01

    Very Idea Some Thoughts about Why They Work When they Work.” Science of Computer Programming, 42.1: 11–27. Blanchard, Benjamin S., and Wolter J...degree of MASTER OF SCIENCE IN SYSTEMS ENGINEERING MANAGEMENT from the NAVAL POSTGRADUATE SCHOOL September 2016 Approved by...acceptable period of time.” References Brooks, Frederick P. 2010. The Design of the Design, Essays from a Computer Scientist. Boston, MA: Pearson

  8. In Search of Design Principles for Developing Digital Learning and Performance Support for a Student Design Task

    ERIC Educational Resources Information Center

    Bollen, Lars; van der Meij, Hans; Leemkuil, Henny; McKenney, Susan

    2015-01-01

    A digital learning and performance support environment for university student design tasks was developed. This paper describes on the design rationale, process, and the usage results to arrive at a core set of design principles for the construction of such an environment. We present a collection of organizational, technical, and course-related…

  9. Compound prism design principles, II: triplet and Janssen prisms

    PubMed Central

    Hagen, Nathan; Tkaczyk, Tomasz S.

    2011-01-01

    Continuing the work of the first paper in this series [Appl. Opt. 50, 4998–5011 (2011)], we extend our design methods to compound prisms composed of three independent elements. The increased degrees of freedom of these asymmetric prisms allow designers to achieve greatly improved dispersion linearity. They also, however, require a more careful tailoring of the merit function to achieve design targets, and so we present several new operands for manipulating the compound prisms’ design algorithm. We show that with asymmetric triplet prisms, one can linearize the angular dispersion such that the spectral sampling rate varies by no more than 4% across the entire visible spectral range. Doing this, however, requires large prisms and causes beam compression. By adding a beam compression penalty to the merit function, we show that one can compromise between dispersion linearity and beam compression in order to produce practical systems. For prisms that do not deviate the beam, we show that Janssen prisms provide a form that maintains the degrees of freedom of the triplet and that are capable of up to 32° of dispersion across the visible spectral range. Finally, in order to showcase some of the design flexibility of three-element prisms, we also show how to design for higher-order spectral dispersion to create a two-dimensional spectrum. PMID:22423146

  10. Compound prism design principles, II: triplet and Janssen prisms.

    PubMed

    Hagen, Nathan; Tkaczyk, Tomasz S

    2011-09-01

    Continuing the work of the first paper in this series [Appl. Opt. 50, 4998-5011 (2011)], we extend our design methods to compound prisms composed of three independent elements. The increased degrees of freedom of these asymmetric prisms allow designers to achieve greatly improved dispersion linearity. They also, however, require a more careful tailoring of the merit function to achieve design targets, and so we present several new operands for manipulating the compound prisms' design algorithm. We show that with asymmetric triplet prisms, one can linearize the angular dispersion such that the spectral sampling rate varies by no more than 4% across the entire visible spectral range. Doing this, however, requires large prisms and causes beam compression. By adding a beam compression penalty to the merit function, we show that one can compromise between dispersion linearity and beam compression in order to produce practical systems. For prisms that do not deviate the beam, we show that Janssen prisms provide a form that maintains the degrees of freedom of the triplet and that are capable of up to 32° of dispersion across the visible spectral range. Finally, in order to showcase some of the design flexibility of three-element prisms, we also show how to design for higher-order spectral dispersion to create a two-dimensional spectrum.

  11. A Sequential Design Laboratory Experiment for Separating Particles by Fluidization Principles.

    ERIC Educational Resources Information Center

    Joye, Donald D.

    1985-01-01

    Describes a semester-long project in which students designed, built, and operated an apparatus to separate particles by fluidization principles. Each laboratory group worked on a separate step of the design in a sequence selected by the instructor in a manner similar to the way a design team might function. (JN)

  12. Thirty-Three Educational Design Principles for Schools & Community Learning Centers.

    ERIC Educational Resources Information Center

    Lackney, Jeffrey A.

    This document provides a framework of educational design principles from which educators and design professionals can structure the content of their educational facility development process, from the earliest strategic and educational planning stage to design, construction, occupancy, and facility management. Each of the 33 educational design…

  13. Emergent features and perceptual objects: re-examining fundamental principles in analogical display design.

    PubMed

    Holt, Jerred; Bennett, Kevin B; Flach, John M

    2015-01-01

    Two sets of design principles for analogical visual displays, based on the concepts of emergent features and perceptual objects, are described. An interpretation of previous empirical findings for three displays (bar graph, polar graphic, alphanumeric) is provided from both perspectives. A fourth display (configural coordinate) was designed using principles of ecological interface design (i.e. direct perception). An experiment was conducted to evaluate performance (accuracy and latency of state identification) with these four displays. Numerous significant effects were obtained and a clear rank ordering of performance emerged (from best to worst): configural coordinate, bar graph, alphanumeric and polar graphic. These findings are consistent with principles of design based on emergent features; they are inconsistent with principles based on perceptual objects. Some limitations of the configural coordinate display are discussed and a redesign is provided. Practitioner Summary: Principles of ecological interface design, which emphasise the quality of very specific mappings between domain, display and observer constraints, are described; these principles are applicable to the design of all analogical graphical displays.

  14. The design principles of edutainment system for autistic children with communication difficulties

    NASA Astrophysics Data System (ADS)

    Hussain, Azham; Abdullah, Adil; Husni, Husniza

    2016-08-01

    Approximately 50% of all individuals with Autism have difficulties in developing functional language owing to communication deterioration. Mobile devices with installed educational games help these individuals feel more comfortable and relaxed doing such activities. Although numerous mobile applications are available for individuals with Autism, they are difficult to use; particularly in terms of user-interface design. From the analysis of existing apps for autistic children, an app design principles are proposed based on interaction design (IxD), that would fulfil the users' requirements in a better manner. Five applications were involved in this analysis. The analysis identified fifteen suggestions for the design principles. These recommendations are offered by this paper towards designing and developing a prototype app for autistic children. This paper introduces an edutainment-system design principle formulated to help develop the communication skills of children with Autism-spectrum disorders.

  15. Fuzzy Controller Design Using Evolutionary Techniques for Twin Rotor MIMO System: A Comparative Study

    PubMed Central

    Hashim, H. A.; Abido, M. A.

    2015-01-01

    This paper presents a comparative study of fuzzy controller design for the twin rotor multi-input multioutput (MIMO) system (TRMS) considering most promising evolutionary techniques. These are gravitational search algorithm (GSA), particle swarm optimization (PSO), artificial bee colony (ABC), and differential evolution (DE). In this study, the gains of four fuzzy proportional derivative (PD) controllers for TRMS have been optimized using the considered techniques. The optimization techniques are developed to identify the optimal control parameters for system stability enhancement, to cancel high nonlinearities in the model, to reduce the coupling effect, and to drive TRMS pitch and yaw angles into the desired tracking trajectory efficiently and accurately. The most effective technique in terms of system response due to different disturbances has been investigated. In this work, it is observed that GSA is the most effective technique in terms of solution quality and convergence speed. PMID:25960738

  16. Evolutionary design of a generalized polynomial neural network for modelling sediment transport in clean pipes

    NASA Astrophysics Data System (ADS)

    Ebtehaj, Isa; Bonakdari, Hossein; Khoshbin, Fatemeh

    2016-10-01

    To determine the minimum velocity required to prevent sedimentation, six different models were proposed to estimate the densimetric Froude number (Fr). The dimensionless parameters of the models were applied along with a combination of the group method of data handling (GMDH) and the multi-target genetic algorithm. Therefore, an evolutionary design of the generalized GMDH was developed using a genetic algorithm with a specific coding scheme so as not to restrict connectivity configurations to abutting layers only. In addition, a new preserving mechanism by the multi-target genetic algorithm was utilized for the Pareto optimization of GMDH. The results indicated that the most accurate model was the one that used the volumetric concentration of sediment (CV), relative hydraulic radius (d/R), dimensionless particle number (Dgr) and overall sediment friction factor (λs) in estimating Fr. Furthermore, the comparison between the proposed method and traditional equations indicated that GMDH is more accurate than existing equations.

  17. Fuzzy Controller Design Using Evolutionary Techniques for Twin Rotor MIMO System: A Comparative Study.

    PubMed

    Hashim, H A; Abido, M A

    2015-01-01

    This paper presents a comparative study of fuzzy controller design for the twin rotor multi-input multioutput (MIMO) system (TRMS) considering most promising evolutionary techniques. These are gravitational search algorithm (GSA), particle swarm optimization (PSO), artificial bee colony (ABC), and differential evolution (DE). In this study, the gains of four fuzzy proportional derivative (PD) controllers for TRMS have been optimized using the considered techniques. The optimization techniques are developed to identify the optimal control parameters for system stability enhancement, to cancel high nonlinearities in the model, to reduce the coupling effect, and to drive TRMS pitch and yaw angles into the desired tracking trajectory efficiently and accurately. The most effective technique in terms of system response due to different disturbances has been investigated. In this work, it is observed that GSA is the most effective technique in terms of solution quality and convergence speed.

  18. Can evolutionary design of social networks make it easier to be 'green'?

    PubMed

    Dickinson, Janis L; Crain, Rhiannon L; Reeve, H Kern; Schuldt, Jonathon P

    2013-09-01

    The social Web is swiftly becoming a living laboratory for understanding human cooperation on massive scales. It has changed how we organize, socialize, and tackle problems that benefit from the efforts of a large crowd. A new, applied, behavioral ecology has begun to build on theoretical and empirical studies of cooperation, integrating research in the fields of evolutionary biology, social psychology, social networking, and citizen science. Here, we review the ways in which these disciplines inform the design of Internet environments to support collective pro-environmental behavior, tapping into proximate prosocial mechanisms and models of social evolution, as well as generating opportunities for 'field studies' to discover how we can support massive collective action and shift environmental social norms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Signal design using nonlinear oscillators and evolutionary algorithms: application to phase-locked loop disruption.

    PubMed

    Olson, C C; Nichols, J M; Michalowicz, J V; Bucholtz, F

    2011-06-01

    This work describes an approach for efficiently shaping the response characteristics of a fixed dynamical system by forcing with a designed input. We obtain improved inputs by using an evolutionary algorithm to search a space of possible waveforms generated by a set of nonlinear, ordinary differential equations (ODEs). Good solutions are those that result in a desired system response subject to some input efficiency constraint, such as signal power. In particular, we seek to find inputs that best disrupt a phase-locked loop (PLL). Three sets of nonlinear ODEs are investigated and found to have different disruption capabilities against a model PLL. These differences are explored and implications for their use as input signal models are discussed. The PLL was chosen here as an archetypal example but the approach has broad applicability to any input∕output system for which a desired input cannot be obtained analytically.

  20. Picbreeder: a case study in collaborative evolutionary exploration of design space.

    PubMed

    Secretan, Jimmy; Beato, Nicholas; D'Ambrosio, David B; Rodriguez, Adelein; Campbell, Adam; Folsom-Kovarik, Jeremiah T; Stanley, Kenneth O

    2011-01-01

    For domains in which fitness is subjective or difficult to express formally, interactive evolutionary computation (IEC) is a natural choice. It is possible that a collaborative process combining feedback from multiple users can improve the quality and quantity of generated artifacts. Picbreeder, a large-scale online experiment in collaborative interactive evolution (CIE), explores this potential. Picbreeder is an online community in which users can evolve and share images, and most importantly, continue evolving others' images. Through this process of branching from other images, and through continually increasing image complexity made possible by the underlying neuroevolution of augmenting topologies (NEAT) algorithm, evolved images proliferate unlike in any other current IEC system. This paper discusses not only the strengths of the Picbreeder approach, but its challenges and shortcomings as well, in the hope that lessons learned will inform the design of future CIE systems.

  1. Linear versus branching depictions of evolutionary history: implications for diagram design.

    PubMed

    Novick, Laura R; Shade, Courtney K; Catley, Kefyn M

    2011-07-01

    This article reports the results of an experiment involving 108 college students with varying backgrounds in biology. Subjects answered questions about the evolutionary history of sets of hominid and equine taxa. Each set of taxa was presented in one of three diagrammatic formats: a noncladogenic diagram found in a contemporary biology textbook or a cladogram in either the ladder or tree format. As predicted, the textbook diagrams, which contained linear components, were more likely than the cladogram formats to yield explanations of speciation as an anagenic process, a common misconception among students. In contrast, the branching cladogram formats yielded more appropriate explanations concerning levels of ancestry than did the textbook diagrams. Although students with stronger backgrounds in biology did better than those with weaker biology backgrounds, they generally showed the same effects of diagrammatic format. Implications of these results for evolution education and for diagram design more generally are discussed.

  2. Fundamental Design Principles for Transcription-Factor-Based Metabolite Biosensors.

    PubMed

    Mannan, Ahmad A; Liu, Di; Zhang, Fuzhong; Oyarzún, Diego A

    2017-08-09

    Metabolite biosensors are central to current efforts toward precision engineering of metabolism. Although most research has focused on building new biosensors, their tunability remains poorly understood and is fundamental for their broad applicability. Here we asked how genetic modifications shape the dose-response curve of biosensors based on metabolite-responsive transcription factors. Using the lac system in Escherichia coli as a model system, we built promoter libraries with variable operator sites that reveal interdependencies between biosensor dynamic range and response threshold. We developed a phenomenological theory to quantify such design constraints in biosensors with various architectures and tunable parameters. Our theory reveals a maximal achievable dynamic range and exposes tunable parameters for orthogonal control of dynamic range and response threshold. Our work sheds light on fundamental limits of synthetic biology designs and provides quantitative guidelines for biosensor design in applications such as dynamic pathway control, strain optimization, and real-time monitoring of metabolism.

  3. Design principles and realization of electro-optical circuit boards

    NASA Astrophysics Data System (ADS)

    Betschon, Felix; Lamprecht, Tobias; Halter, Markus; Beyer, Stefan; Peterson, Harry

    2013-02-01

    The manufacturing of electro-optical circuit boards (EOCB) is based to a large extent on established technologies. First products with embedded polymer waveguides are currently produced in series. The range of applications within the sensor and data communication markets is growing with the increasing maturity level. EOCBs require design flows, processes and techniques similar to existing printed circuit board (PCB) manufacturing and appropriate for optical signal transmission. A key aspect is the precise and automated assembly of active and passive optical components to the optical waveguides which has to be supported by the technology. The design flow is described after a short introduction into the build-up of EOCBs and the motivation for the usage of this technology within the different application fields. Basis for the design of EOCBs are the required optical signal transmission properties. Thereafter, the devices for the electro-optical conversion are chosen and the optical coupling approach is defined. Then, the planar optical elements (waveguides, splitters, couplers) are designed and simulated. This phase already requires co-design of the optical and electrical domain using novel design flows. The actual integration of an optical system into a PCB is shown in the last part. The optical layer is thereby laminated to the purely electrical PCB using a conventional PCB-lamination process to form the EOCB. The precise alignment of the various electrical and optical layers is thereby essential. Electrical vias are then generated, penetrating also the optical layer, to connect the individual electrical layers. Finally, the board has to be tested electrically and optically.

  4. Evolutionary multiobjective design of a flexible caudal fin for robotic fish.

    PubMed

    Clark, Anthony J; Tan, Xiaobo; McKinley, Philip K

    2015-11-25

    Robotic fish accomplish swimming by deforming their bodies or other fin-like appendages. As an emerging class of embedded computing system, robotic fish are anticipated to play an important role in environmental monitoring, inspection of underwater structures, tracking of hazardous wastes and oil spills, and the study of live fish behaviors. While integration of flexible materials (into the fins and/or body) holds the promise of improved swimming performance (in terms of both speed and maneuverability) for these robots, such components also introduce significant design challenges due to the complex material mechanics and hydrodynamic interactions. The problem is further exacerbated by the need for the robots to meet multiple objectives (e.g., both speed and energy efficiency). In this paper, we propose an evolutionary multiobjective optimization approach to the design and control of a robotic fish with a flexible caudal fin. Specifically, we use the NSGA-II algorithm to investigate morphological and control parameter values that optimize swimming speed and power usage. Several evolved fin designs are validated experimentally with a small robotic fish, where fins of different stiffness values and sizes are printed with a multi-material 3D printer. Experimental results confirm the effectiveness of the proposed design approach in balancing the two competing objectives.

  5. Design principles for Fresnel lenses in telecentric applications

    NASA Astrophysics Data System (ADS)

    McCall, Brian; Claytor, Nelson

    2016-09-01

    Fresnel lenses have been found by some optical systems designers to be useful in combination with a main lens to provide quality telecentric images. Aspheric Fresnel lenses are an ideal choice for this application because they achieve a high degree of telecentricity across the entire field of view and introduce very little distortion. In a telecentric system consisting of an aspheric Fresnel lens and an off the shelf non-telecentric main lens, the design parameters are few. Aberration theory, constraints on the visibility of the grooves, and physical constraints can effectively be used to quickly determine if a solution exists for a given application and identify the solution space if it does.

  6. Design Principles, Implementation And Evaluation For Inquiry-Based Astronomy:

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Michael

    2015-09-01

    This thesis is situated in the context of an Australian high school level astronomy intervention project which aimed to enable students to undertake real science with professional grade 2-metre class telescopes. The thesis explores the context and background within which the project was situated and the main blocking factors preventing successful implementation culminating in an outline of the education design used in, and the evaluation of, the project. This work has illustrated that with careful design and sufficient teacher training and support, inquiry-based astronomy can feasibly be undertaken in the high-school classroom.

  7. Serious game design principles: The impact of game design on learning outcomes

    NASA Astrophysics Data System (ADS)

    Martin, Michael W.

    This dissertation examines the research question "How do video game design principles affect learning outcomes in serious games?" This research first develops a theoretical foundation concerning the meaning of the terms "game" and "serious game". This conceptual clarification is broken down into analytic propositions, which state that games have participants, rules, goals and challenges, and synthetic propositions, which state that the games should be intrinsically compelling, provide meaningful choices, and be self encapsulated. Based on these synthetic propositions, three hypotheses were developed. The hypotheses are that games with an enhanced aesthetic presentation, more meaningful choices, or provide player competition will elicit higher learning outcomes than identical games without these factors. These hypotheses were tested via a quantitative experiment involving 172 undergraduate students in the Old Dominion University Chemistry Department. The students were asked to play a chemistry-oriented serious game entitled Element Solitaire©, which was created by the research author. The students were randomly given different treatments of the Element Solitaire© game to play, and the difference between their learning outcomes were compared. The experimental results demonstrated that the aesthetic presentation of a game can have a significant impact upon the learning outcome. The experiment was not able to discern significant effects from the choice or competition conditions, but further examination of the experimental data did reveal some insight into these aspects of serious game design. Choices need to provide the player with options that have a sufficient value that they will be considered and the application of competition within games needs to be judiciously implemented to promote a positive affect for all players. The results of the theoretical foundations and empirical evidence were then combined with additional theoretical research to develop a set of

  8. Evolutionary bridges to new protein folds: design of C-terminal Cro protein chameleon sequences

    PubMed Central

    Anderson, William J.; Van Dorn, Laura O.; Ingram, Wendy M.; Cordes, Matthew H. J.

    2011-01-01

    Regions of amino-acid sequence that are compatible with multiple folds may facilitate evolutionary transitions in protein structure. In a previous study, we described a heuristically designed chameleon sequence (SASF1, structurally ambivalent sequence fragment 1) that could adopt either of two naturally occurring conformations (α-helical or β-sheet) when incorporated as part of the C-terminal dimerization subdomain of two structurally divergent transcription factors, P22 Cro and λ Cro. Here we describe longer chameleon designs (SASF2 and SASF3) that in the case of SASF3 correspond to the full C-terminal half of the ordered region of a P22 Cro/λ Cro sequence alignment (residues 34–57). P22-SASF2 and λWDD-SASF2 show moderate thermal stability in denaturation curves monitored by circular dichroism (Tm values of 46 and 55°C, respectively), while P22-SASF3 and λWDD-SASF3 have somewhat reduced stability (Tm values of 33 and 49°C, respectively). 13C and 1H NMR secondary chemical shift analysis confirms two C-terminal α-helices for P22-SASF2 (residues 36–45 and 54–57) and two C-terminal β-strands for λWDD-SASF2 (residues 40–45 and 50–52), corresponding to secondary structure locations in the two parent sequences. Backbone relaxation data show that both chameleon sequences have a relatively well-ordered structure. Comparisons of 15N-1H correlation spectra for SASF2 and SASF3-containing proteins strongly suggest that SASF3 retains the chameleonism of SASF2. Both Cro C-terminal conformations can be encoded in a single sequence, showing the plausibility of linking different Cro folds by smooth evolutionary transitions. The N-terminal subdomain, though largely conserved in structure, also exerts an important contextual influence on the structure of the C-terminal region. PMID:21676898

  9. Mammalian designer cells: Engineering principles and biomedical applications.

    PubMed

    Xie, Mingqi; Fussenegger, Martin

    2015-07-01

    Biotechnology is a widely interdisciplinary field focusing on the use of living cells or organisms to solve established problems in medicine, food production and agriculture. Synthetic biology, the science of engineering complex biological systems that do not exist in nature, continues to provide the biotechnology industry with tools, technologies and intellectual property leading to improved cellular performance. One key aspect of synthetic biology is the engineering of deliberately reprogrammed designer cells whose behavior can be controlled over time and space. This review discusses the most commonly used techniques to engineer mammalian designer cells; while control elements acting on the transcriptional and translational levels of target gene expression determine the kinetic and dynamic profiles, coupling them to a variety of extracellular stimuli permits their remote control with user-defined trigger signals. Designer mammalian cells with novel or improved biological functions not only directly improve the production efficiency during biopharmaceutical manufacturing but also open the door for cell-based treatment strategies in molecular and translational medicine. In the future, the rational combination of multiple sets of designer cells could permit the construction and regulation of higher-order systems with increased complexity, thereby enabling the molecular reprogramming of tissues, organisms or even populations with highest precision.

  10. MANUAL: BIOVENTING PRINCIPLES AND PRACTICE VOLUME II. BIOVENTING DESIGN

    EPA Science Inventory

    The results from bioventing research and development efforts and from the pilot-scale bioventing systems have been used to produce this two-volume manual. Although this design manual has been written based on extensive experience with petroleum hydrocarbons (and thus, many exampl...

  11. MANUAL: BIOVENTING PRINCIPLES AND PRACTICE VOLUME II. BIOVENTING DESIGN

    EPA Science Inventory

    The results from bioventing research and development efforts and from the pilot-scale bioventing systems have been used to produce this two-volume manual. Although this design manual has been written based on extensive experience with petroleum hydrocarbons (and thus, many exampl...

  12. Five Principles for MOOC Design: With a Case Study

    ERIC Educational Resources Information Center

    Drake, John R.; O'Hara, Margaret; Seeman, Elaine

    2015-01-01

    New web technologies have enabled online education to take on a massive scale, prompting many universities to create massively open online courses (MOOCs) that take advantage of these technologies in a seemingly effortless manner. Designing a MOOC, however, is anything but trivial. It involves developing content, learning activities, and…

  13. Five Principles for MOOC Design: With a Case Study

    ERIC Educational Resources Information Center

    Drake, John R.; O'Hara, Margaret; Seeman, Elaine

    2015-01-01

    New web technologies have enabled online education to take on a massive scale, prompting many universities to create massively open online courses (MOOCs) that take advantage of these technologies in a seemingly effortless manner. Designing a MOOC, however, is anything but trivial. It involves developing content, learning activities, and…

  14. A possibilistic approach to rotorcraft design through a multi-objective evolutionary algorithm

    NASA Astrophysics Data System (ADS)

    Chae, Han Gil

    Most of the engineering design processes in use today in the field may be considered as a series of successive decision making steps. The decision maker uses information at hand, determines the direction of the procedure, and generates information for the next step and/or other decision makers. However, the information is often incomplete, especially in the early stages of the design process of a complex system. As the complexity of the system increases, uncertainties eventually become unmanageable using traditional tools. In such a case, the tools and analysis values need to be "softened" to account for the designer's intuition. One of the methods that deals with issues of intuition and incompleteness is possibility theory. Through the use of possibility theory coupled with fuzzy inference, the uncertainties estimated by the intuition of the designer are quantified for design problems. By involving quantified uncertainties in the tools, the solutions can represent a possible set, instead of a crisp spot, for predefined levels of certainty. From a different point of view, it is a well known fact that engineering design is a multi-objective problem or a set of such problems. The decision maker aims to find satisfactory solutions, sometimes compromising the objectives that conflict with each other. Once the candidates of possible solutions are generated, a satisfactory solution can be found by various decision-making techniques. A number of multi-objective evolutionary algorithms (MOEAs) have been developed, and can be found in the literature, which are capable of generating alternative solutions and evaluating multiple sets of solutions in one single execution of an algorithm. One of the MOEA techniques that has been proven to be very successful for this class of problems is the strength Pareto evolutionary algorithm (SPEA) which falls under the dominance-based category of methods. The Pareto dominance that is used in SPEA, however, is not enough to account for the

  15. Laser beam riding guided system principle and design research

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Jin, Yi; Xu, Zhou; Xing, Hao

    2016-01-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  16. An evolutionary scenario for the origin of pentaradial echinoderms-implications from the hydraulic principles of form determination.

    PubMed

    Gudo, Michael

    2005-01-01

    The early evolutionary history of echinoderms was reconstructed on the basis of structural-functional considerations and application of the quasi-engineering approach of 'Konstruktions-Morphologie'. According to the presented evolutionary scenario, a bilaterally symmetrical ancestor, such as an enteropneust-like organism, became gradually modified into a pentaradial echinoderm by passing through an intermediate pterobranch-like stage. The arms of a pentaradial echinoderm are identified as hydraulic outgrowths from the central coelomic cavity of the bilateral ancestor which developed due to a shortening of the body in length but widening in the diameter. The resulting pentaradial symmetry is a consequence of mechanical laws that dictate minimal contact surface areas among hydraulic pneumatic entities. These developed in the coelomic cavity (metacoel) in the bilaterally symmetrical ancestor, when from the already U-shaped mesentery with the intestinal tract two additional U-shaped bows developed directly or subsequently. During the subsequent development tensile chords of the mesentery 'sewed' the gut with the body wall first in three and secondly in five 'seams'. During the direct development five 'seams' between tensile chords and body wall developed straightly. These internal tensile chords subdivide the body coelom into five hydraulic subsystems ('pneus'), which eventually arrange in a pentaradial pattern. The body could then enlarge only between the tensile chords, which means that five hydraulic bulges developed. These bulges initially supported the tentacles and finally each of them enclosed the tentacle until only the feather-like appendages of the tentacles projected over the surface. The tentacles with their feathers were transformed into the ambulacral system, and the bulges become the arms. These morphological transformations were accompanied and partly determined by specific histological modifications, such as the development of mutable connective

  17. Wideband Waveform Design principles for Solid-state Weather Radars

    SciTech Connect

    Bharadwaj, Nitin; Chandrasekar, V.

    2012-01-01

    The use of solid-state transmitter is becoming a key part of the strategy to realize a network of low cost electronically steered radars. However, solid-state transmitters have low peak powers and this necessitates the use of pulse compression waveforms. In this paper a frequency diversity wideband waveforms design is proposed to mitigate low sensitivity of solid-state transmitters. In addition, the waveforms mitigate the range eclipsing problem associated with long pulse compression. An analysis of the performance of pulse compression using mismatched compression filters designed to minimize side lobe levels is presented. The impact of range side lobe level on the retrieval of Doppler moments are presented. Realistic simulations are performed based on CSU-CHILL radar data and Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) Integrated Project I (IP1) radar data.

  18. Bridging the gaps in design methodologies by evolutionary optimization of the stability and proficiency of designed Kemp eliminase KE59

    PubMed Central

    Khersonsky, Olga; Kiss, Gert; Röthlisberger, Daniela; Dym, Orly; Albeck, Shira; Houk, Kendall N.; Baker, David; Tawfik, Dan S.

    2012-01-01

    Computational design is a test of our understanding of enzyme catalysis and a means of engineering novel, tailor-made enzymes. While the de novo computational design of catalytically efficient enzymes remains a challenge, designed enzymes may comprise unique starting points for further optimization by directed evolution. Directed evolution of two computationally designed Kemp eliminases, KE07 and KE70, led to low to moderately efficient enzymes (kcat/Km values of ≤ 5 × 104 M-1s-1). Here we describe the optimization of a third design, KE59. Although KE59 was the most catalytically efficient Kemp eliminase from this design series (by kcat/Km, and by catalyzing the elimination of nonactivated benzisoxazoles), its impaired stability prevented its evolutionary optimization. To boost KE59’s evolvability, stabilizing consensus mutations were included in the libraries throughout the directed evolution process. The libraries were also screened with less activated substrates. Sixteen rounds of mutation and selection led to > 2,000-fold increase in catalytic efficiency, mainly via higher kcat values. The best KE59 variants exhibited kcat/Km values up to 0.6 × 106 M-1s-1, and kcat/kuncat values of ≤ 107 almost regardless of substrate reactivity. Biochemical, structural, and molecular dynamics (MD) simulation studies provided insights regarding the optimization of KE59. Overall, the directed evolution of three different designed Kemp eliminases, KE07, KE70, and KE59, demonstrates that computational designs are highly evolvable and can be optimized to high catalytic efficiencies. PMID:22685214

  19. Design Principles for Covalent Organic Frameworks in Energy Storage Applications.

    PubMed

    Alahakoon, Sampath B; Thompson, Christina M; Occhialini, Gino; Smaldone, Ronald Alexander

    2017-03-16

    Covalent organic frameworks (COFs) are an exciting class of microporous materials that have been explored as energy storage materials for more than a decade. This review will discusses the efforts to develop these materials for applications in gas and electrical power storage. This review will also discuss some of the design strategies for developing the gas sorption properties of COFs and mechanistic studies on their formation.

  20. Designing sensory-substitution devices: Principles, pitfalls and potential1

    PubMed Central

    Kristjánsson, Árni; Moldoveanu, Alin; Jóhannesson, Ómar I.; Balan, Oana; Spagnol, Simone; Valgeirsdóttir, Vigdís Vala; Unnthorsson, Rúnar

    2016-01-01

    An exciting possibility for compensating for loss of sensory function is to augment deficient senses by conveying missing information through an intact sense. Here we present an overview of techniques that have been developed for sensory substitution (SS) for the blind, through both touch and audition, with special emphasis on the importance of training for the use of such devices, while highlighting potential pitfalls in their design. One example of a pitfall is how conveying extra information about the environment risks sensory overload. Related to this, the limits of attentional capacity make it important to focus on key information and avoid redundancies. Also, differences in processing characteristics and bandwidth between sensory systems severely constrain the information that can be conveyed. Furthermore, perception is a continuous process and does not involve a snapshot of the environment. Design of sensory substitution devices therefore requires assessment of the nature of spatiotemporal continuity for the different senses. Basic psychophysical and neuroscientific research into representations of the environment and the most effective ways of conveying information should lead to better design of sensory substitution systems. Sensory substitution devices should emphasize usability, and should not interfere with other inter- or intramodal perceptual function. Devices should be task-focused since in many cases it may be impractical to convey too many aspects of the environment. Evidence for multisensory integration in the representation of the environment suggests that researchers should not limit themselves to a single modality in their design. Finally, we recommend active training on devices, especially since it allows for externalization, where proximal sensory stimulation is attributed to a distinct exterior object. PMID:27567755

  1. Learning Technology Specification: Principles for Army Training Designers and Developers

    DTIC Science & Technology

    2013-09-01

    large cognitive load spread 7 across modalities than it is to have one overloaded modality (Moreno & Mayer, 2007). Haptic simulators have taken... haptic simulations (San Diego et al., 2012, Shönborn, Bivall, & Tibell, 2011). The literature described in this section results in several...Weil, & Bareket, 1994). When designing a haptic simulator for training dental school students to drill teeth, San Diego et al. (2012) specifically

  2. Novel Natural Convection Heat Sink Design Concepts From First Principles

    DTIC Science & Technology

    2016-06-01

    Appendix B. Upon the conclusion of this study, Plunkett Associates used a Direct Metal Laser Sintering process to construct novel heat sinks that...on the design, pin-fins in the horizontal and upward vertical direction can be comparable while the downward vertical direction provides the worst...number of tubes were varied and all additional variations are a direct result of the manipulation of these three parameters. Table 1. Governing

  3. Design principles for Bernal spirals and helices with tunable pitch

    NASA Astrophysics Data System (ADS)

    Fejer, Szilard N.; Chakrabarti, Dwaipayan; Kusumaatmaja, Halim; Wales, David J.

    2014-07-01

    Using the framework of potential energy landscape theory, we describe two in silico designs for self-assembling helical colloidal superstructures based upon dipolar dumbbells and Janus-type building blocks, respectively. Helical superstructures with controllable pitch length are obtained using external magnetic field driven assembly of asymmetric dumbbells involving screened electrostatic as well as magnetic dipolar interactions. The pitch of the helix is tuned by modulating the Debye screening length over an experimentally accessible range. The second design is based on building blocks composed of rigidly linked spheres with short-range anisotropic interactions, which are predicted to self-assemble into Bernal spirals. These spirals are quite flexible, and longer helices undergo rearrangements via cooperative, hinge-like moves, in agreement with experiment.Using the framework of potential energy landscape theory, we describe two in silico designs for self-assembling helical colloidal superstructures based upon dipolar dumbbells and Janus-type building blocks, respectively. Helical superstructures with controllable pitch length are obtained using external magnetic field driven assembly of asymmetric dumbbells involving screened electrostatic as well as magnetic dipolar interactions. The pitch of the helix is tuned by modulating the Debye screening length over an experimentally accessible range. The second design is based on building blocks composed of rigidly linked spheres with short-range anisotropic interactions, which are predicted to self-assemble into Bernal spirals. These spirals are quite flexible, and longer helices undergo rearrangements via cooperative, hinge-like moves, in agreement with experiment. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00324a

  4. Application of Systems Engineering Principles for Concept Design of New Products

    NASA Astrophysics Data System (ADS)

    Kumar, Karunakaran Nair Ajith; Jagathy Raj, Vettuvila Purushothaman

    2017-04-01

    A successful engineering design is one that meets the user requirements completely. Design essentially starts with concept design followed by detailed design. The importance of concept design is brought out in this paper. Systems engineering principles and practices are used to build the concept design starting from user requirements and user specified reference scenarios. Systems engineering methodology helps in proper understanding of the user requirements, identifying multiple solutions, short listing the candidate solutions and finally selecting one or two feasible designs. A case study analysis is presented to demonstrate the systems engineering practices followed for concept abstraction and preliminary design of a typical engineering system.

  5. Fixed structure compensator design using a constrained hybrid evolutionary optimization approach.

    PubMed

    Ghosh, Subhojit; Samanta, Susovon

    2014-07-01

    This paper presents an efficient technique for designing a fixed order compensator for compensating current mode control architecture of DC-DC converters. The compensator design is formulated as an optimization problem, which seeks to attain a set of frequency domain specifications. The highly nonlinear nature of the optimization problem demands the use of an initial parameterization independent global search technique. In this regard, the optimization problem is solved using a hybrid evolutionary optimization approach, because of its simple structure, faster execution time and greater probability in achieving the global solution. The proposed algorithm involves the combination of a population search based optimization approach i.e. Particle Swarm Optimization (PSO) and local search based method. The op-amp dynamics have been incorporated during the design process. Considering the limitations of fixed structure compensator in achieving loop bandwidth higher than a certain threshold, the proposed approach also determines the op-amp bandwidth, which would be able to achieve the same. The effectiveness of the proposed approach in meeting the desired frequency domain specifications is experimentally tested on a peak current mode control dc-dc buck converter.

  6. Attribute index and uniform design based multiobjective association rule mining with evolutionary algorithm.

    PubMed

    Zhang, Jie; Wang, Yuping; Feng, Junhong

    2013-01-01

    In association rule mining, evaluating an association rule needs to repeatedly scan database to compare the whole database with the antecedent, consequent of a rule and the whole rule. In order to decrease the number of comparisons and time consuming, we present an attribute index strategy. It only needs to scan database once to create the attribute index of each attribute. Then all metrics values to evaluate an association rule do not need to scan database any further, but acquire data only by means of the attribute indices. The paper visualizes association rule mining as a multiobjective problem rather than a single objective one. In order to make the acquired solutions scatter uniformly toward the Pareto frontier in the objective space, elitism policy and uniform design are introduced. The paper presents the algorithm of attribute index and uniform design based multiobjective association rule mining with evolutionary algorithm, abbreviated as IUARMMEA. It does not require the user-specified minimum support and minimum confidence anymore, but uses a simple attribute index. It uses a well-designed real encoding so as to extend its application scope. Experiments performed on several databases demonstrate that the proposed algorithm has excellent performance, and it can significantly reduce the number of comparisons and time consumption.

  7. Design and Characterization of Photoelectrodes from First Principles

    SciTech Connect

    Ogitsu, T; Wood, B; Choi, W; Huda, M; Wei, S

    2012-05-11

    Although significant performance improvements have been realized since the first demonstration of sunlight-driven water splitting in 1972, mainstream adoption of photoelectrochemical (PEC) cells remains limited by an absence of cost-effective electrodes that show simultaneously high conversion efficiency and good durability. Here we outline current and future efforts to use advanced theoretical techniques to guide the development of a durable, high-performance PEC electrode material. Working in close collaboration with experimental synthesis and characterization teams, we use a twofold approach focusing on: (1) rational design of novel high-performance electrode materials; and (2) characterization and optimization of the electrode-electrolyte interface.

  8. Designing thin film materials — Ternary borides from first principles

    PubMed Central

    Euchner, H.; Mayrhofer, P.H.

    2015-01-01

    Exploiting the mechanisms responsible for the exceptional properties of aluminum based nitride coatings, we apply ab initio calculations to develop a recipe for designing functional thin film materials based on ternary diborides. The combination of binary diborides, preferring different structure types, results in supersaturated metastable ternary systems with potential for phase transformation induced effects. For the exemplary cases of MxW1 − xB2 (with M = Al, Ti, V) we show by detailed ab initio calculations that the respective ternary solid solutions are likely to be experimentally accessible by modern depositions techniques. PMID:26082562

  9. Limitations on Design Principles for Public Key Protocols

    DTIC Science & Technology

    1996-01-01

    receiving the increase such as a full name, employee ID number, etc. There are bearer authorizations, messages which apply to the bearer of that...protocol is that Alice’s signature on the unencrypted H and T is useless. If Bob wants to argue before a judge that Alice engaged in this protocol run...ACM Press, New York, November 1993. [5] R. Bird, I. Gopal, A. Herzberg , P. Janson, S. Kut- ten, R. Molva, and M. Yung. Systematic Design of a Family

  10. Design principles for a flywheel energy store for road vehicles

    SciTech Connect

    Acarnley, P.P.; Mecrow, B.C.; Burdess, J.S.; Fawcett, J.N.; Kelly, J.G.; Dickinson, P.G.

    1996-11-01

    This paper introduces a flywheel energy storage device capable of enhancing the fuel economy of a hybrid-type road vehicle. A number of possible drive types are considered and the permanent magnet machine drive is shown to provide the best solution. Reasons for selecting a device using an axial-field configuration with single-rotor and double-stator sections are described. Electrical, magnetic, and mechanical design data are presented for a full-scale prototype device with 240 KJ of usable energy storage and 25 kW of power transfer, operating at speeds up to 50,000 r/min, with a 10% duty cycle.

  11. Design principles for a flywheel energy store for road vehicles

    SciTech Connect

    Acarnley, P.P.; Mecrow, B.C.; Burdess, J.S.; Fawcett, J.N.; Kelly, J.G.; Dickinson, P.G.

    1995-12-31

    This paper introduces a flywheel energy storage device capable of enhancing the fuel economy of a hybrid-type road vehicle. A number of possible drive types is considered and the permanent magnet machine drive is shown to provide the best solution. Reasons for selecting a device using an axial-field configuration with single rotor and double stator sections are described. Electrical, magnetic and mechanical design data are presented for a full-scale prototype device with 240 kJ of usable energy storage and 25 kW of power transfer, operating at speeds up to 50,000 revs per minute, with a 10% duty cycle.

  12. Design Principles of Biological Oscillators through Optimization: Forward and Reverse Analysis.

    PubMed

    Otero-Muras, Irene; Banga, Julio R

    2016-01-01

    From cyanobacteria to human, sustained oscillations coordinate important biological functions. Although much has been learned concerning the sophisticated molecular mechanisms underlying biological oscillators, design principles linking structure and functional behavior are not yet fully understood. Here we explore design principles of biological oscillators from a multiobjective optimization perspective, taking into account the trade-offs between conflicting performance goals or demands. We develop a comprehensive tool for automated design of oscillators, based on multicriteria global optimization that allows two modes: (i) the automatic design (forward problem) and (ii) the inference of design principles (reverse analysis problem). From the perspective of synthetic biology, the forward mode allows the solution of design problems that mimic some of the desirable properties appearing in natural oscillators. The reverse analysis mode facilitates a systematic exploration of the design space based on Pareto optimality concepts. The method is illustrated with two case studies: the automatic design of synthetic oscillators from a library of biological parts, and the exploration of design principles in 3-gene oscillatory systems.

  13. Design Principles of Biological Oscillators through Optimization: Forward and Reverse Analysis

    PubMed Central

    Otero-Muras, Irene; Banga, Julio R.

    2016-01-01

    From cyanobacteria to human, sustained oscillations coordinate important biological functions. Although much has been learned concerning the sophisticated molecular mechanisms underlying biological oscillators, design principles linking structure and functional behavior are not yet fully understood. Here we explore design principles of biological oscillators from a multiobjective optimization perspective, taking into account the trade-offs between conflicting performance goals or demands. We develop a comprehensive tool for automated design of oscillators, based on multicriteria global optimization that allows two modes: (i) the automatic design (forward problem) and (ii) the inference of design principles (reverse analysis problem). From the perspective of synthetic biology, the forward mode allows the solution of design problems that mimic some of the desirable properties appearing in natural oscillators. The reverse analysis mode facilitates a systematic exploration of the design space based on Pareto optimality concepts. The method is illustrated with two case studies: the automatic design of synthetic oscillators from a library of biological parts, and the exploration of design principles in 3-gene oscillatory systems. PMID:27977695

  14. Primate Anatomy, Kinematics, and Principles for Humanoid Design

    NASA Technical Reports Server (NTRS)

    Ambrose, Robert O.; Ambrose, Catherine G.

    2004-01-01

    The primate order of animals is investigated for clues in the design of Humanoid Robots. The pursuit is directed with a theory that kinematics, musculature, perception, and cognition can be optimized for specific tasks by varying the proportions of limbs, and in particular, the points of branching in kinematic trees such as the primate skeleton. Called the Bifurcated Chain Hypothesis, the theory is that the branching proportions found in humans may be superior to other animals and primates for the tasks of dexterous manipulation and other human specialties. The primate taxa are defined, contemporary primate evolution hypotheses are critiqued, and variations within the order are noted. The kinematic branching points of the torso, limbs and fingers are studied for differences in proportions across the order, and associated with family and genus capabilities and behaviors. The human configuration of a long waist, long neck, and short arms is graded using a kinematic workspace analysis and a set of design axioms for mobile manipulation robots. It scores well. The re emergence of the human waist, seen in early Prosimians and Monkeys for arboreal balance, but lost in the terrestrial Pongidae, is postulated as benefiting human dexterity. The human combination of an articulated waist and neck will be shown to enable the use of smaller arms, achieving greater regions of workspace dexterity than the larger limbs of Gorillas and other Hominoidea.

  15. Primate Anatomy, Kinematics, and Principles for Humanoid Design

    NASA Technical Reports Server (NTRS)

    Ambrose, Robert O.; Ambrose, Catherine G.

    2004-01-01

    The primate order of animals is investigated for clues in the design of Humanoid Robots. The pursuit is directed with a theory that kinematics, musculature, perception, and cognition can be optimized for specific tasks by varying the proportions of limbs, and in particular, the points of branching in kinematic trees such as the primate skeleton. Called the Bifurcated Chain Hypothesis, the theory is that the branching proportions found in humans may be superior to other animals and primates for the tasks of dexterous manipulation and other human specialties. The primate taxa are defined, contemporary primate evolution hypotheses are critiqued, and variations within the order are noted. The kinematic branching points of the torso, limbs and fingers are studied for differences in proportions across the order, and associated with family and genus capabilities and behaviors. The human configuration of a long waist, long neck, and short arms is graded using a kinematic workspace analysis and a set of design axioms for mobile manipulation robots. It scores well. The re emergence of the human waist, seen in early Prosimians and Monkeys for arboreal balance, but lost in the terrestrial Pongidae, is postulated as benefiting human dexterity. The human combination of an articulated waist and neck will be shown to enable the use of smaller arms, achieving greater regions of workspace dexterity than the larger limbs of Gorillas and other Hominoidea.

  16. Medicinal chemistry design principles for liver targeting through OATP transporters.

    PubMed

    Tu, Meihua; Mathiowetz, Alan M; Pfefferkorn, Jeffrey A; Cameron, Kimberly O; Dow, Robert L; Litchfield, John; Di, Li; Feng, Bo; Liras, Spiros

    2013-01-01

    The tissue distribution of a drug can have significant impact on both its efficacy and safety. As a consequence, selective tissue targeting has become an attractive approach for optimizing the window between efficacy and safety for drug targets that are ubiquitously expressed and important in key physiological processes. Given the liver's key role in metabolic regulation and the fact that it is the principal tissue affected by diseases such as hepatitis B and C viruses as well as hepatocellular carcinoma, designing drugs with hepatoselective distribution profiles is an important strategy in developing safe cardiovascular, metabolic, antiviral and oncology drug candidates. In this paper, we analyze a diverse set of compounds from four different projects within Pfizer that specifically pursued liver targeting strategies. A number of key in vitro and in vivo ADME endpoints were collected including in vivo tissue exposure, oral bioavailability, clearance in preclinical species and in vitro hepatic OATP uptake, in vitro rat liver microsomal stability, permeability, solubility, logD, and others. From this analysis, we determined a set of general structure-liver-selectivity guides for designing orally bioavailable, liver-targeted candidates using liver specific OATP transporters. The guidelines have been formulated using straightforward molecular descriptors and in vitro properties that medicinal chemists routinely optimize. Our analysis emphasizes the need to focus on a chemical space with balanced lipophilicity, high aqueous solubility and low passive permeability in order to achieve the desired hepatoselectivity while maintaining fraction absorbed.

  17. Evolutionary molecular medicine.

    PubMed

    Nesse, Randolph M; Ganten, Detlev; Gregory, T Ryan; Omenn, Gilbert S

    2012-05-01

    Evolution has long provided a foundation for population genetics, but some major advances in evolutionary biology from the twentieth century that provide foundations for evolutionary medicine are only now being applied in molecular medicine. They include the need for both proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, competition between alleles, co-evolution, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are transforming evolutionary biology in ways that create even more opportunities for progress at its interfaces with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and related principles to speed the development of evolutionary molecular medicine.

  18. Design of a proof of principle high current transport experiment

    SciTech Connect

    Lund, S.M.; Bangerter, R.O.; Barnard, J.J.; Celata, C.M.; Faltens, A.; Friedman, A.; Kwan, J.W.; Lee, E.P.; Seidl, P.A.

    2000-01-15

    Preliminary designs of an intense heavy-ion beam transport experiment to test issues for Heavy Ion Fusion (HIF) are presented. This transport channel will represent a single high current density beam at full driver scale and will evaluate practical issues such as aperture filling factors, electrons, halo, imperfect vacuum, etc., that cannot be fully tested using scaled experiments. Various machine configurations are evaluated in the context of the range of physics and technology issues that can be explored in a manner relevant to a full scale driver. it is anticipated that results from this experiment will allow confident construction of next generation ''Integrated Research Experiments'' leading to a full scale driver for energy production.

  19. The fern cavitation catapult: mechanism and design principles.

    PubMed

    Llorens, C; Argentina, M; Rojas, N; Westbrook, J; Dumais, J; Noblin, X

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

  20. The fern cavitation catapult: mechanism and design principles

    PubMed Central

    Llorens, C.; Argentina, M.; Rojas, N.; Westbrook, J.; Dumais, J.; Noblin, X.

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12–25 cells, which successively: (i) stores energy by evaporation of the cells’ content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s–1). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately −100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised. PMID:26763327

  1. Making Blended Instruction Better: Integrating the Principles of Universal Design for Instruction into Course Design and Delivery

    ERIC Educational Resources Information Center

    Dukes, Lyman L., III; Koorland, Mark A.; Scott, Sally S.

    2009-01-01

    Online instruction in general and blended instruction in particular have gained a sizable and permanent foothold in postsecondary educational environments. In addition, student diversity has become the norm. Universal design for instruction is a framework that consists of nine principles for instructional design and delivery; it proposes that…

  2. First principles design of a core bioenergetic transmembrane electron transfer protein

    PubMed Central

    Goparaju, Geetha; Fry, Bryan A.; Chobot, Sarah E.; Wiedman, Gregory; Moser, Christopher C.; Dutton, P. Leslie; Discher, Bohdana M.

    2016-01-01

    Here we describe the design, E. coli expression and characterization of a simplified, adaptable and functionally transparent single chain 4-α-helix transmembrane protein frame that binds multiple heme and light activatable porphyrins. Such man-made cofactor-binding oxidoreductases, designed from first principles with minimal reference to natural protein sequences, are known as maquettes. This design is an adaptable frame aiming to uncover core engineering principles governing bioenergetic transmembrane electron-transfer function and recapitulate protein archetypes proposed to represent the origins of photosynthesis. PMID:26672896

  3. Design principles for wave plate metasurfaces using plasmonic L-shaped nanoantennas

    NASA Astrophysics Data System (ADS)

    Tahir, Asad A.; Schulz, Sebastian A.; De Leon, Israel; Boyd, Robert W.

    2017-03-01

    Plasmonic L-shaped antennas are an important building block of metasurfaces and have been used to fabricate ultra-thin wave plates. In this work we present principles that can be used to design wave plates at a wavelength of choice and for diverse application requirements using arrays of L-shaped plasmonic antennas. We derive these design principles by studying the behavior of the vast parameter space of these antenna arrays. We show that there are two distinct regimes: a weak inter-particle coupling and a strong inter-particle coupling regime. We describe the behavior of the antenna array in each regime with regards to wave plate functionality, without resorting to approximate theoretical models. Our work is the first to explain these design principles and serves as a guide for designing wave plates for specific application requirements using plasmonic L-shaped antenna arrays.

  4. Ten Guiding Principles for Designing Online Modules That Involve International Collaborations

    ERIC Educational Resources Information Center

    Porcaro, David; Carrier, Carol

    2014-01-01

    As ideas and personnel flow across borders, there are many opportunities for instructional designers to collaboratively design online modules with international teams. These collaborations can take many shapes, as varying levels of localization and within-team communication are employed. This paper looks at ten guiding principles that are shaping…

  5. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train operation...

  6. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train operation...

  7. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train operation...

  8. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train operation...

  9. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train operation...

  10. 75 FR 80571 - Core Principles and Other Requirements for Designated Contract Markets

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ... Contract Markets; Proposed Rule #0;#0;Federal Register / Vol. 75 , No. 245 / Wednesday, December 22, 2010... Principles and Other Requirements for Designated Contract Markets AGENCY: Commodity Futures Trading... the designation and operation of contract markets, implement the Dodd-Frank Act's new statutory...

  11. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Sustainable principles for siting, design and construction. 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND CONSTRUCTION OF NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS...

  12. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Sustainable principles for siting, design and construction. 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND CONSTRUCTION OF NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS...

  13. Researching Principles of Lesson Design to Realize the Pedagogical Opportunities of Mathematics Analysis Software

    ERIC Educational Resources Information Center

    Pierce, Robyn; Stacey, Kaye

    2009-01-01

    Taking advantage of pedagogical opportunities afforded by new technology requires appropriately designed lessons. This article reports on the use of "lesson study" to research principles for the design of a lesson aiming to take advantage of multiple representations. The lesson, for year 10 students who had personal access to TI-Nspire, focused on…

  14. Principle design of a protontherapy, rapid-cycling, variable energy spiral FFAG

    NASA Astrophysics Data System (ADS)

    Antoine, S.; Autin, B.; Beeckman, W.; Collot, J.; Conjat, M.; Forest, F.; Fourrier, J.; Froidefond, E.; Lancelot, J. L.; Mandrillon, J.; Mandrillon, P.; Méot, F.; Mori, Y.; Neuvéglise, D.; Ohmori, C.; Pasternak, J.; Planche, T.

    2009-04-01

    The FFAG method is nowadays seen as a potential candidate for the acceleration of protons and light ions for hadrontherapy. This has motivated the design of a principle protontherapy installation, in the frame of the RACCAM project. This article presents the design study, a medical spiral scaling FFAG assembly, capable of producing variable energy proton beams, with potentially high repetition and dose delivery rates.

  15. Learning Effects of a Science Textbook Designed with Adapted Cognitive Process Principles on Grade 5 Students

    ERIC Educational Resources Information Center

    Cheng, Ming-Chang; Chou, Pei-I; Wang, Ya-Ting; Lin, Chih-Ho

    2015-01-01

    This study investigates how the illustrations in a science textbook, with their design modified according to cognitive process principles, affected students' learning performance. The quasi-experimental design recruited two Grade 5 groups (N?=?58) as the research participants. The treatment group (n?=?30) used the modified version of the textbook,…

  16. Designing a Community of Practice: Principles and Practices of the GIsML Community.

    ERIC Educational Resources Information Center

    Palincsar, AnneMarie Sullivan; Magnusson, Shirley J.; Marano, Nancy; Ford, Danielle; Brown, Nancy

    1998-01-01

    Describes an elementary-level professional-development project designed to build a community of practice focused on inquiry-based science teaching (Guided Inquiry supporting Multiple Literacies). Presents the basic tenets that guided the development of learning experiences for teachers and illustrates how the principles influenced the design of…

  17. Developing design principles for a Virtual Hospice: improving access to care.

    PubMed

    Taylor, Andrea; French, Tara; Raman, Sneha

    2017-08-23

    Providing access to hospice services will become increasingly difficult due to the pressures of an ageing population and limited resources. To help address this challenge, a small number of services called Virtual Hospice have been established. This paper presents early-stage design work on a Virtual Hospice to improve access to services provided by a hospice (Highland Hospice) serving a largely remote and rural population in Scotland, UK. The study was structured as a series of Experience Labs with Highland Hospice staff, healthcare professionals and patients. Experience Labs employ a participatory design approach where participants are placed at the centre of the design process, helping to ensure that the resultant service meets their needs. Data from the Experience Labs were analysed using qualitative thematic analysis and design analysis. A number of themes and barriers to accessing Highland Hospice services were identified. In response, an initial set of seven design principles was developed. Design principles are high-level guidelines that are used to improve prioritisation and decision making during the design process by ensuring alignment with research insights. The design principles were piloted with a group of stakeholders and gained positive feedback. The design principles are intended to guide the ongoing development of the Highland Hospice Virtual Hospice. However, the challenges faced by Highland Hospice in delivering services in a largely remote and rural setting are not unique. The design principles, encompassing digital and non-digital guidelines, or the design approach could be applied by other hospices in the UK or overseas. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. Design Principles of Perovskites for Thermochemical Oxygen Separation.

    PubMed

    Ezbiri, Miriam; Allen, Kyle M; Gàlvez, Maria E; Michalsky, Ronald; Steinfeld, Aldo

    2015-06-08

    Separation and concentration of O2 from gas mixtures is central to several sustainable energy technologies, such as solar-driven synthesis of liquid hydrocarbon fuels from CO2 , H2 O, and concentrated sunlight. We introduce a rationale for designing metal oxide redox materials for oxygen separation through "thermochemical pumping" of O2 against a pO2 gradient with low-grade process heat. Electronic structure calculations show that the activity of O vacancies in metal oxides pinpoints the ideal oxygen exchange capacity of perovskites. Thermogravimetric analysis and high-temperature X-ray diffraction for SrCoO3-δ , BaCoO3-δ and BaMnO3-δ perovskites and Ag2 O and Cu2 O references confirm the predicted performance of SrCoO3-δ , which surpasses the performance of state-of-the-art Cu2 O at these conditions with an oxygen exchange capacity of 44 mmol O 2 mol SrCoO 3-δ(-1) exchanged at 12.1 μmol O 2 min(-1)  g(-1) at 600-900 K. The redox trends are understood due to lattice expansion and electronic charge transfer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Design Principles of Perovskites for Thermochemical Oxygen Separation

    PubMed Central

    Ezbiri, Miriam; Allen, Kyle M.; Gàlvez, Maria E.; Steinfeld, Aldo

    2015-01-01

    Abstract Separation and concentration of O2 from gas mixtures is central to several sustainable energy technologies, such as solar‐driven synthesis of liquid hydrocarbon fuels from CO2, H2O, and concentrated sunlight. We introduce a rationale for designing metal oxide redox materials for oxygen separation through “thermochemical pumping” of O2 against a pO2 gradient with low‐grade process heat. Electronic structure calculations show that the activity of O vacancies in metal oxides pinpoints the ideal oxygen exchange capacity of perovskites. Thermogravimetric analysis and high‐temperature X‐ray diffraction for SrCoO3−δ, BaCoO3−δ and BaMnO3−δ perovskites and Ag2O and Cu2O references confirm the predicted performance of SrCoO3−δ, which surpasses the performance of state‐of‐the‐art Cu2O at these conditions with an oxygen exchange capacity of 44 mmol O 2 mol SrCoO 3−δ −1 exchanged at 12.1 μmol O 2 min−1 g−1 at 600–900 K. The redox trends are understood due to lattice expansion and electronic charge transfer. PMID:25925955

  20. Dental education in Queensland: II. Principles of curriculum design.

    PubMed

    Walsh, L J; Seymour, G J

    2001-03-01

    A modern dental curriculum must produce graduates who are competent to practise in a variety of settings immediately upon graduation; cognisant of community needs and the social milieu in which they serve their patients' health needs; able to anticipate and cope with changes following graduation; committed to self-improvement, willing to change to reflect best clinical practice; and equipped with skills for self-assessment and lifelong learning. This requires the appropriate balance of emphasis on educational content and educational process. This paper outlines the design considerations underlying the new BDSc curriculum at the University of Queensland. This curriculum uses an integrated rather than subject-based approach, with student-centred modes of learning as the principal learning style. Active learning strategies develop critical thinking and clinical problem-solving skills. Learning occurs in the context of a clinical situation (either overt or implied). Year 2 provides the major scientific foundations, and later years build upon this base, particularly through problem-based learning. Senior clinical staff involved in teaching in earlier parts of the course, help provide an overt clinical context to learning activities. The integrated curriculum model provides clinically relevant education in basic sciences and scientifically based education in clinical care. The curriculum has a focus on outcomes and on preparation for general practice. Importantly, it has an open and transparent structure, and each component is linked explicitly with the competencies expected of the new dental graduate.

  1. Biological differences between the evolutionary lineages within Phytophthora ramorum and Phytophthora lateralis: Should the lineages be formally taxonomically designated?

    Treesearch

    Clive Brasier

    2017-01-01

    It is now generally accepted that the four evolutionary lineages of Phytophthora ramorum (informally designated NA1, NA2, EU1, and EU2) are relatively anciently divergent populations, recently introduced into Europe and North America from different, unknown geographic locations; that recombinants between them are genetically unstable and probably...

  2. Application of hybrid evolutionary algorithms to low exhaust emission diesel engine design

    NASA Astrophysics Data System (ADS)

    Jeong, S.; Obayashi, S.; Minemura, Y.

    2008-01-01

    A hybrid evolutionary algorithm, consisting of a genetic algorithm (GA) and particle swarm optimization (PSO), is proposed. Generally, GAs maintain diverse solutions of good quality in multi-objective problems, while PSO shows fast convergence to the optimum solution. By coupling these algorithms, GA will compensate for the low diversity of PSO, while PSO will compensate for the high computational costs of GA. The hybrid algorithm was validated using standard test functions. The results showed that the hybrid algorithm has better performance than either a pure GA or pure PSO. The method was applied to an engineering design problem—the geometry of diesel engine combustion chamber reducing exhaust emissions such as NOx, soot and CO was optimized. The results demonstrated the usefulness of the present method to this engineering design problem. To identify the relation between exhaust emissions and combustion chamber geometry, data mining was performed with a self-organising map (SOM). The results indicate that the volume near the lower central part of the combustion chamber has a large effect on exhaust emissions and the optimum chamber geometry will vary depending on fuel injection angle.

  3. Designing Crop Simulation Web Service with Service Oriented Architecture Principle

    NASA Astrophysics Data System (ADS)

    Chinnachodteeranun, R.; Hung, N. D.; Honda, K.

    2015-12-01

    Crop simulation models are efficient tools for simulating crop growth processes and yield. Running crop models requires data from various sources as well as time-consuming data processing, such as data quality checking and data formatting, before those data can be inputted to the model. It makes the use of crop modeling limited only to crop modelers. We aim to make running crop models convenient for various users so that the utilization of crop models will be expanded, which will directly improve agricultural applications. As the first step, we had developed a prototype that runs DSSAT on Web called as Tomorrow's Rice (v. 1). It predicts rice yields based on a planting date, rice's variety and soil characteristics using DSSAT crop model. A user only needs to select a planting location on the Web GUI then the system queried historical weather data from available sources and expected yield is returned. Currently, we are working on weather data connection via Sensor Observation Service (SOS) interface defined by Open Geospatial Consortium (OGC). Weather data can be automatically connected to a weather generator for generating weather scenarios for running the crop model. In order to expand these services further, we are designing a web service framework consisting of layers of web services to support compositions and executions for running crop simulations. This framework allows a third party application to call and cascade each service as it needs for data preparation and running DSSAT model using a dynamic web service mechanism. The framework has a module to manage data format conversion, which means users do not need to spend their time curating the data inputs. Dynamic linking of data sources and services are implemented using the Service Component Architecture (SCA). This agriculture web service platform demonstrates interoperability of weather data using SOS interface, convenient connections between weather data sources and weather generator, and connecting

  4. A new theoretical approach to terrestrial ecosystem science based on multiscale observations and eco-evolutionary optimality principles

    NASA Astrophysics Data System (ADS)

    Prentice, Iain Colin; Wang, Han; Cornwell, William; Davis, Tyler; Dong, Ning; Evans, Bradley; Keenan, Trevor; Peng, Changhui; Stocker, Benjamin; Togashi, Henrique; Wright, Ian

    2016-04-01

    Ecosystem science focuses on biophysical interactions of organisms and their abiotic environment, and comprises vital aspects of Earth system function such as the controls of carbon, water and energy exchanges between ecosystems and the atmosphere. Global numerical models of these processes have proliferated, and have been incorporated as standard components of Earth system models whose ambitious goal is to predict the coupled behaviour of the oceans, atmosphere and land on time scales from minutes to millennia. Unfortunately, however, the performance of most current terrestrial ecosystem models is highly unsatisfactory. Models typically fail the most basic observational benchmarks, and diverge greatly from one another when called upon to predict the response of ecosystem function and composition to environmental changes beyond the narrow range for which they were developed. This situation seems to have arisen for two inter-related reasons. First, general principles underlying many basic terrestrial biogeochemical processes have been neither clearly formulated nor adequately tested. Second, extensive observational data sets that could be used to test process formulations have become available only quite recently, long postdating the emergence of the current modelling paradigm. But the situation has changed now and ecosystem science needs to change too, to reflect both recent theoretical advances and the vast increase in the availability of relevant data sets at scales from the leaf to the globe. This presentation will outline an emerging mathematical theory that links biophysical plant and ecosystem processes through testable hypotheses derived from the principle of optimization by natural selection. The development and testing of this theory has depended on the availability of extensive data sets on climate, leaf traits (including δ13C measurements), and ecosystem properties including green vegetation cover and land-atmosphere CO2 fluxes. Achievements to date

  5. Integrated active and passive control design methodology for the LaRC CSI evolutionary model

    NASA Technical Reports Server (NTRS)

    Voth, Christopher T.; Richards, Kenneth E., Jr.; Schmitz, Eric; Gehling, Russel N.; Morgenthaler, Daniel R.

    1994-01-01

    A general design methodology to integrate active control with passive damping was demonstrated on the NASA LaRC CSI Evolutionary Model (CEM), a ground testbed for future large, flexible spacecraft. Vibration suppression controllers designed for Line-of Sight (LOS) minimization were successfully implemented on the CEM. A frequency-shaped H2 methodology was developed, allowing the designer to specify the roll-off of the MIMO compensator. A closed loop bandwidth of 4 Hz, including the six rigid body modes and the first three dominant elastic modes of the CEM was achieved. Good agreement was demonstrated between experimental data and analytical predictions for the closed loop frequency response and random tests. Using the Modal Strain Energy (MSE) method, a passive damping treatment consisting of 60 viscoelastically damped struts was designed, fabricated and implemented on the CEM. Damping levels for the targeted modes were more than an order of magnitude larger than for the undamped structure. Using measured loss and stiffness data for the individual damped struts, analytical predictions of the damping levels were very close to the experimental values in the (1-10) Hz frequency range where the open loop model matched the experimental data. An integrated active/passive controller was successfully implemented on the CEM and was evaluated against an active-only controller. A two-fold increase in the effective control bandwidth and further reductions of 30 percent to 50 percent in the LOS RMS outputs were achieved compared to an active-only controller. Superior performance was also obtained compared to a High-Authority/Low-Authority (HAC/LAC) controller.

  6. Integrated active and passive control design methodology for the LaRC CSI evolutionary model

    NASA Astrophysics Data System (ADS)

    Voth, Christopher T.; Richards, Kenneth E., Jr.; Schmitz, Eric; Gehling, Russel N.; Morgenthaler, Daniel R.

    1994-04-01

    A general design methodology to integrate active control with passive damping was demonstrated on the NASA LaRC CSI Evolutionary Model (CEM), a ground testbed for future large, flexible spacecraft. Vibration suppression controllers designed for Line-of Sight (LOS) minimization were successfully implemented on the CEM. A frequency-shaped H2 methodology was developed, allowing the designer to specify the roll-off of the MIMO compensator. A closed loop bandwidth of 4 Hz, including the six rigid body modes and the first three dominant elastic modes of the CEM was achieved. Good agreement was demonstrated between experimental data and analytical predictions for the closed loop frequency response and random tests. Using the Modal Strain Energy (MSE) method, a passive damping treatment consisting of 60 viscoelastically damped struts was designed, fabricated and implemented on the CEM. Damping levels for the targeted modes were more than an order of magnitude larger than for the undamped structure. Using measured loss and stiffness data for the individual damped struts, analytical predictions of the damping levels were very close to the experimental values in the (1-10) Hz frequency range where the open loop model matched the experimental data. An integrated active/passive controller was successfully implemented on the CEM and was evaluated against an active-only controller. A two-fold increase in the effective control bandwidth and further reductions of 30 percent to 50 percent in the LOS RMS outputs were achieved compared to an active-only controller. Superior performance was also obtained compared to a High-Authority/Low-Authority (HAC/LAC) controller.

  7. Efficient algorithms for protein sequence design and the analysis of certain evolutionary fitness landscapes.

    PubMed

    Kleinberg, J M

    1999-01-01

    Protein sequence design is a natural inverse problem to protein structure prediction: given a target structure in three dimensions, we wish to design an amino acid sequence that is likely fold to it. A model of Sun, Brem, Chan, and Dill casts this problem as an optimization on a space of sequences of hydrophobic (H) and polar (P) monomers; the goal is to find a sequence that achieves a dense hydrophobic core with few solvent-exposed hydrophobic residues. Sun et al. developed a heuristic method to search the space of sequences, without a guarantee of optimality or near-optimality; Hart subsequently raised the computational tractability of constructing an optimal sequence in this model as an open question. Here we resolve this question by providing an efficient algorithm to construct optimal sequences; our algorithm has a polynomial running time, and performs very efficiently in practice. We illustrate the implementation of our method on structures drawn from the Protein Data Bank. We also consider extensions of the model to larger amino acid alphabets, as a way to overcome the limitations of the binary H/P alphabet. We show that for a natural class of arbitrarily large alphabets, it remains possible to design optimal sequences efficiently. Finally, we analyze some of the consequences of this sequence design model for the study of evolutionary fitness landscapes. A given target structure may have many sequences that are optimal in the model of Sun et al.; following a notion raised by the work of J. Maynard Smith, we can ask whether these optimal sequences are "connected" by successive point mutations. We provide a polynomial-time algorithm to decide this connectedness property, relative to a given target structure. We develop the algorithm by first solving an analogous problem expressed in terms of submodular functions, a fundamental object of study in combinatorial optimization.

  8. Using Persuasive Design Principles in Motivational Feeling towards Children Dental Anxiety (CDA)

    NASA Astrophysics Data System (ADS)

    Salam, Sobihatun Nur-Abdul; Yahaya, Wan Ahmad Jaafar-Wan; Ali, Azillah-Mohd

    This paper is focusing the potential use of persuasive design principles in motivating children's dental anxiety. The main intention of the paper is to emphasize an attempt of how persuasive design principle can be designed into educational material using CD ROM based multimedia learning environment to overcome the CDA. Firstly, we describe a problem domain which discuss about the universal feeling of CDA and secondly the current practices in handling those negative feelings. Thirdly, the conceptual background of PMLE and how the principle has been applied in designing the information interfaces and presentation of a persuasive multimedia learning environment (PMLE) are described. Fourthly, an experimental design was used to validate the effects of prototype which assessed children dental anxiety level before and after the demonstration and utilization of a PMLE. Primary school children age between seven and nine years old are selected as respondents. Fifthly, the result of the study has revealed the feedback from children regarding baseline test and children dental anxiety test. It shows how by using persuasive design principles as an overall strategy in designing PMLE was able to motivate children feelings towards dental anxiety and could let the children behave in a good manner for dental visit in the future.

  9. Evolutionary bridges to new protein folds: design of C-terminal Cro protein chameleon sequences.

    PubMed

    Anderson, William J; Van Dorn, Laura O; Ingram, Wendy M; Cordes, Matthew H J

    2011-09-01

    Regions of amino-acid sequence that are compatible with multiple folds may facilitate evolutionary transitions in protein structure. In a previous study, we described a heuristically designed chameleon sequence (SASF1, structurally ambivalent sequence fragment 1) that could adopt either of two naturally occurring conformations (α-helical or β-sheet) when incorporated as part of the C-terminal dimerization subdomain of two structurally divergent transcription factors, P22 Cro and λ Cro. Here we describe longer chameleon designs (SASF2 and SASF3) that in the case of SASF3 correspond to the full C-terminal half of the ordered region of a P22 Cro/λ Cro sequence alignment (residues 34-57). P22-SASF2 and λ(WDD)-SASF2 show moderate thermal stability in denaturation curves monitored by circular dichroism (T(m) values of 46 and 55°C, respectively), while P22-SASF3 and λ(WDD)-SASF3 have somewhat reduced stability (T(m) values of 33 and 49°C, respectively). (13)C and (1)H NMR secondary chemical shift analysis confirms two C-terminal α-helices for P22-SASF2 (residues 36-45 and 54-57) and two C-terminal β-strands for λ(WDD)-SASF2 (residues 40-45 and 50-52), corresponding to secondary structure locations in the two parent sequences. Backbone relaxation data show that both chameleon sequences have a relatively well-ordered structure. Comparisons of (15)N-(1)H correlation spectra for SASF2 and SASF3-containing proteins strongly suggest that SASF3 retains the chameleonism of SASF2. Both Cro C-terminal conformations can be encoded in a single sequence, showing the plausibility of linking different Cro folds by smooth evolutionary transitions. The N-terminal subdomain, though largely conserved in structure, also exerts an important contextual influence on the structure of the C-terminal region.

  10. Human experience and product usability: principles to assist the design of user-product interactions.

    PubMed

    Chamorro-Koc, Marianella; Popovic, Vesna; Emmison, Michael

    2009-07-01

    This paper introduces research that investigates how human experience influences people's understandings of product usability. It describes an experiment that employs visual representation of concepts to elicit participants' ideas of a product's use. Results from the experiment lead to the identification of relationships between human experience, knowledge, and context-of-use--relationships that influence designers' and users' concepts of product usability. These relationships are translated into design principles that inform the design activity with respect to the aspects of experience that trigger people's understanding of a product's use. A design tool (ECEDT) is devised to aid designers in the application of these principles. This tool is then trialled in the context of a design task in order to verify applicability of the findings.

  11. Part 1: Evidence-based facility design using Transforming Care at the Bedside principles.

    PubMed

    Devine, Deborah A; Wenger, Barb; Krugman, Mary; Zwink, Jennifer E; Shiskowsky, Kaycee; Hagman, Jan; Limon, Shelly; Sanders, Carolyn; Reeves, Catherine

    2015-02-01

    An academic hospital used Transforming Care at the Bedside (TCAB) principles as the framework for generating evidence-based recommendations for the design of an expansion of the current hospital. The interdisciplinary team used the table of evidence-based data to advocate for a patient- and family-centered, safe, and positive work environment. A nurse project manager acted as liaison between the TCAB design team, architects, and facilities and design consultants. Part 2 of this series describes project evaluation outcomes.

  12. Objects and mappings: incompatible principles of display design - a critique of Marino and Mahan.

    PubMed

    Bennett, Kevin B

    2005-01-01

    Representation aiding (and similar approaches that share the general orientation) has a great deal of utility, predictive ability, and explanatory power. Marino and Mahan (2005) discuss principles that are critical to the RA approach (configurality, emergent features, and mappings) in a reasonable fashion. However, the application of these principles is far from reasonable. The authors explicitly realize the potential for interactions between nutrients: "The nutritional quality of a food product is a multidimensional concept, and higher order interactions between nutrients may exist" (p. 126). However, they made no effort to discover the nature of these interactions: "No attempt was made to identify contingent interactions between nutrients" (p. 126). Despite not knowing the nature of the interactions between nutrients, they purposely chose a highly configural display that produced numerous emergent features dependent upon these interactions: "A radial spoke display was selected because of the strong configural properties of such display formats (Bennett & Flach, 1992)" (p. 124). Finally, the authors show apparent disdain for the specific mappings among domain, agent, and display that are fundamental to the RA approach: "[O]ther configural display formats could have been used" (p. 124). It is impossible to reconcile these statements and the RA approach to display design. However, these statements make perfect sense if a perceptual object is a guiding principle in one's approach to display design. Marino and Mahan (2005) draw heavily upon the principle of a perceptual object in their design justifications, experimental predictions, and interpretations of results. As we have indicated here and elsewhere (Bennett & Flach, 1992), we believe that these two sets of organizing principles for display design (i.e., objects and mappings) are incompatible. Display design will never be an exact science; there will always be elements of art and creativity. However, the guiding

  13. A pilot study designed to acquaint medical educators with basic pedagogic principles.

    PubMed

    McLeod, P J; Brawer, J; Steinert, Y; Chalk, C; McLeod, A

    2008-02-01

    Faculty development activities in medical schools regularly target teaching behaviours but rarely address basic pedagogic principles underlying those behaviours. Although many teachers have an intuitive or tacit knowledge of basic pedagogic principles, overt knowledge of fundamental educational principles is rare. We conducted a short-term pilot study designed to transform teachers' tacit knowledge into explicit knowledge of pedagogic principles. We hypothesized that conscious awareness of these principles will positively influence their teaching effectiveness. The intervention included a workshop, provision of a workbook on pedagogic principles and free access to educational consultants. For the intervention, we chose a purposive sample of experienced teachers at our medical school. Evaluation of the impact of the intervention using questionnaires and semi-structured interviews revealed three notable findings; 1. Participants were surprised to discover the existence of an extensive body of pedagogic science underlying teaching and learning. 2. They were enthusiastic about the intervention and expressed interest in learning more about basic pedagogic principles. 3. The knowledge acquired had an immediate impact on their teaching.

  14. A study of usability principles and interface design for mobile e-books.

    PubMed

    Wang, Chao-Ming; Huang, Ching-Hua

    2015-01-01

    This study examined usability principles and interface designs in order to understand the relationship between the intentions of mobile e-book interface designs and users' perceptions. First, this study summarised 4 usability principles and 16 interface attributes, in order to conduct usability testing and questionnaire survey by referring to Nielsen (1993), Norman (2002), and Yeh (2010), who proposed the usability principles. Second, this study used the interviews to explore the perceptions and behaviours of user operations through senior users of multi-touch prototype devices. The results of this study are as follows: (1) users' behaviour of operating an interactive interface is related to user prior experience; (2) users' rating of the visibility principle is related to users' subjective perception but not related to user prior experience; however, users' ratings of the ease, efficiency, and enjoyment principles are related to user prior experience; (3) the interview survey reveals that the key attributes affecting users' behaviour of operating an interface include aesthetics, achievement, and friendliness. This study conducts experiments to explore the effects of users’ prior multi-touch experience on users’ behaviour of operating a mobile e-book interface and users’ rating of usability principles. Both qualitative and quantitative data analyses were performed. By applying protocol analysis, key attributes affecting users’ behaviour of operation were determined.

  15. Combining Interactive Infrastructure Modeling and Evolutionary Algorithm Optimization for Sustainable Water Resources Design

    NASA Astrophysics Data System (ADS)

    Smith, R.; Kasprzyk, J. R.; Zagona, E. A.

    2013-12-01

    Population growth and climate change, combined with difficulties in building new infrastructure, motivate portfolio-based solutions to ensuring sufficient water supply. Powerful simulation models with graphical user interfaces (GUI) are often used to evaluate infrastructure portfolios; these GUI based models require manual modification of the system parameters, such as reservoir operation rules, water transfer schemes, or system capacities. Multiobjective evolutionary algorithm (MOEA) based optimization can be employed to balance multiple objectives and automatically suggest designs for infrastructure systems, but MOEA based decision support typically uses a fixed problem formulation (i.e., a single set of objectives, decisions, and constraints). This presentation suggests a dynamic framework for linking GUI-based infrastructure models with MOEA search. The framework begins with an initial formulation which is solved using a MOEA. Then, stakeholders can interact with candidate solutions, viewing their properties in the GUI model. This is followed by changes in the formulation which represent users' evolving understanding of exigent system properties. Our case study is built using RiverWare, an object-oriented, data-centered model that facilitates the representation of a diverse array of water resources systems. Results suggest that assumptions within the initial MOEA search are violated after investigating tradeoffs and reveal how formulations should be modified to better capture stakeholders' preferences.

  16. Microstructure provides insights into evolutionary design and resilience of Coscinodiscus sp. frustule

    PubMed Central

    Aitken, Zachary H.; Luo, Shi; Reynolds, Stephanie N.; Thaulow, Christian; Greer, Julia R.

    2016-01-01

    We conducted in situ three-point bending experiments on beams with roughly square cross-sections, which we fabricated from the frustule of Coscinodiscus sp. We observe failure by brittle fracture at an average stress of 1.1 GPa. Analysis of crack propagation and shell morphology reveals a differentiation in the function of the frustule layers with the basal layer pores, which deflect crack propagation. We calculated the relative density of the frustule to be ∼30% and show that at this density the frustule has the highest strength-to-density ratio of 1,702 kN⋅m/kg, a significant departure from all reported biologic materials. We also performed nanoindentation on both the single basal layer of the frustule as well as the girdle band and show that these components display similar mechanical properties that also agree well with bending tests. Transmission electron microscopy analysis reveals that the frustule is made almost entirely of amorphous silica with a nanocrystalline proximal layer. No flaws are observed within the frustule material down to 2 nm. Finite element simulations of the three-point bending experiments show that the basal layer carries most of the applied load whereas stresses within the cribrum and areolae layer are an order of magnitude lower. These results demonstrate the natural development of architecture in live organisms to simultaneously achieve light weight, strength, and exceptional structural integrity and may provide insight into evolutionary design. PMID:26858446

  17. Microstructure provides insights into evolutionary design and resilience of Coscinodiscus sp. frustule.

    PubMed

    Aitken, Zachary H; Luo, Shi; Reynolds, Stephanie N; Thaulow, Christian; Greer, Julia R

    2016-02-23

    We conducted in situ three-point bending experiments on beams with roughly square cross-sections, which we fabricated from the frustule of Coscinodiscus sp. We observe failure by brittle fracture at an average stress of 1.1 GPa. Analysis of crack propagation and shell morphology reveals a differentiation in the function of the frustule layers with the basal layer pores, which deflect crack propagation. We calculated the relative density of the frustule to be ∼30% and show that at this density the frustule has the highest strength-to-density ratio of 1,702 kN⋅m/kg, a significant departure from all reported biologic materials. We also performed nanoindentation on both the single basal layer of the frustule as well as the girdle band and show that these components display similar mechanical properties that also agree well with bending tests. Transmission electron microscopy analysis reveals that the frustule is made almost entirely of amorphous silica with a nanocrystalline proximal layer. No flaws are observed within the frustule material down to 2 nm. Finite element simulations of the three-point bending experiments show that the basal layer carries most of the applied load whereas stresses within the cribrum and areolae layer are an order of magnitude lower. These results demonstrate the natural development of architecture in live organisms to simultaneously achieve light weight, strength, and exceptional structural integrity and may provide insight into evolutionary design.

  18. Structural and evolutionary divergence of cyclic nucleotide binding domains in eukaryotic pathogens: Implications for drug design.

    PubMed

    Mohanty, Smita; Kennedy, Eileen J; Herberg, Friedrich W; Hui, Raymond; Taylor, Susan S; Langsley, Gordon; Kannan, Natarajan

    2015-10-01

    Many cellular functions in eukaryotic pathogens are mediated by the cyclic nucleotide binding (CNB) domain, which senses second messengers such as cyclic AMP and cyclic GMP. Although CNB domain-containing proteins have been identified in many pathogenic organisms, an incomplete understanding of how CNB domains in pathogens differ from other eukaryotic hosts has hindered the development of selective inhibitors for CNB domains associated with infectious diseases. Here, we identify and classify CNB domain-containing proteins in eukaryotic genomes to understand the evolutionary basis for CNB domain functional divergence in pathogens. We identify 359 CNB domain-containing proteins in 31 pathogenic organisms and classify them into distinct subfamilies based on sequence similarity within the CNB domain as well as functional domains associated with the CNB domain. Our study reveals novel subfamilies with pathogen-specific variations in the phosphate-binding cassette. Analyzing these variations in light of existing structural and functional data provides new insights into ligand specificity and promiscuity and clues for drug design. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases. Copyright © 2015. Published by Elsevier B.V.

  19. Evolutionary Agent-based Models to design distributed water management strategies

    NASA Astrophysics Data System (ADS)

    Giuliani, M.; Castelletti, A.; Reed, P. M.

    2012-12-01

    There is growing awareness in the scientific community that the traditional centralized approach to water resources management, as described in much of the water resources literature, provides an ideal optimal solution, which is certainly useful to quantify the best physically achievable performance, but is generally inapplicable. Most real world water resources management problems are indeed characterized by the presence of multiple, distributed and institutionally-independent decision-makers. Multi-Agent Systems provide a potentially more realistic alternative framework to model multiple and self-interested decision-makers in a credible context. Each decision-maker can be represented by an agent who, being self-interested, acts according to local objective functions and produces negative externalities on system level objectives. Different levels of coordination can potentially be included in the framework by designing coordination mechanisms to drive the current decision-making structure toward the global system efficiency. Yet, the identification of effective coordination strategies can be particularly complex in modern institutional contexts and current practice is dependent on largely ad-hoc coordination strategies. In this work we propose a novel Evolutionary Agent-based Modeling (EAM) framework that enables a mapping of fully uncoordinated and centrally coordinated solutions into their relative "many-objective" tradeoffs using multiobjective evolutionary algorithms. Then, by analysing the conflicts between local individual agent and global system level objectives it is possible to more fully understand the causes, consequences, and potential solution strategies for coordination failures. Game-theoretic criteria have value for identifying the most interesting alternatives from a policy making point of view as well as the coordination mechanisms that can be applied to obtain these interesting solutions. The proposed approach is numerically tested on a

  20. Advanced Targeting Cost Function Design for Evolutionary Optimization of Control of Logistic Equation

    NASA Astrophysics Data System (ADS)

    Senkerik, Roman; Zelinka, Ivan; Davendra, Donald; Oplatkova, Zuzana

    2010-06-01

    This research deals with the optimization of the control of chaos by means of evolutionary algorithms. This work is aimed on an explanation of how to use evolutionary algorithms (EAs) and how to properly define the advanced targeting cost function (CF) securing very fast and precise stabilization of desired state for any initial conditions. As a model of deterministic chaotic system, the one dimensional Logistic equation was used. The evolutionary algorithm Self-Organizing Migrating Algorithm (SOMA) was used in four versions. For each version, repeated simulations were conducted to outline the effectiveness and robustness of used method and targeting CF.

  1. Use of physiological constraints to identify quantitative design principles for gene expression in yeast adaptation to heat shock

    PubMed Central

    Vilaprinyo, Ester; Alves, Rui; Sorribas, Albert

    2006-01-01

    Background Understanding the relationship between gene expression changes, enzyme activity shifts, and the corresponding physiological adaptive response of organisms to environmental cues is crucial in explaining how cells cope with stress. For example, adaptation of yeast to heat shock involves a characteristic profile of changes to the expression levels of genes coding for enzymes of the glycolytic pathway and some of its branches. The experimental determination of changes in gene expression profiles provides a descriptive picture of the adaptive response to stress. However, it does not explain why a particular profile is selected for any given response. Results We used mathematical models and analysis of in silico gene expression profiles (GEPs) to understand how changes in gene expression correlate to an efficient response of yeast cells to heat shock. An exhaustive set of GEPs, matched with the corresponding set of enzyme activities, was simulated and analyzed. The effectiveness of each profile in the response to heat shock was evaluated according to relevant physiological and functional criteria. The small subset of GEPs that lead to effective physiological responses after heat shock was identified as the result of the tuning of several evolutionary criteria. The experimentally observed transcriptional changes in response to heat shock belong to this set and can be explained by quantitative design principles at the physiological level that ultimately constrain changes in gene expression. Conclusion Our theoretical approach suggests a method for understanding the combined effect of changes in the expression of multiple genes on the activity of metabolic pathways, and consequently on the adaptation of cellular metabolism to heat shock. This method identifies quantitative design principles that facilitate understating the response of the cell to stress. PMID:16584550

  2. Urban Principle of Water Sensitive Design in Kampung Kamboja at Pontianak City

    NASA Astrophysics Data System (ADS)

    Hasriyanti, N.; Ryanti, E.

    2017-07-01

    This study will define the design principles of settlement area banks of the Kapuas Pontianak to approach the concept of water sensitive urban design (WSUD) in densely populated residential areas. Using a case study of a region densely located on the banks of the river with engineering literature to formulate the aspects taken into consideration and the components are arranged in the design, analysis descriptive paradigm rationalistic to identify the characteristics of residential areas riverbank with consideration of elements WSUD and formulate design principles residential area that is sensitive to water. This research is important to do because of problems related to the water management system in the settlement bank of the river in the city of Pontianak do not maximize. So that the primacy of this study contains several objectives to be achieved is to identify the characteristics of the settlement area riverbanks under consideration aspects areas design that is sensitive to water and principle areas design that will formulate the structure of the existing problems related to the needs of the community infrastructure facilities infrastructure neighborhoods and formulate and create guidelines for appropriate technology for integrated water management systems in the residential area of the riverbank and engineering design for the settlements are sensitive to water (WSUD). The final aim of the study is expected to achieve water management systems in residential areas by utilizing the abundant rainwater availability by using LID (Low Impact Development) through the concept of urban design that sensitive water

  3. Mechanical-Kinetic Modeling of a Molecular Walker from a Modular Design Principle

    NASA Astrophysics Data System (ADS)

    Hou, Ruizheng; Loh, Iong Ying; Li, Hongrong; Wang, Zhisong

    2017-02-01

    Artificial molecular walkers beyond burnt-bridge designs are complex nanomachines that potentially replicate biological walkers in mechanisms and functionalities. Improving the man-made walkers up to performance for widespread applications remains difficult, largely because their biomimetic design principles involve entangled kinetic and mechanical effects to complicate the link between a walker's construction and ultimate performance. Here, a synergic mechanical-kinetic model is developed for a recently reported DNA bipedal walker, which is based on a modular design principle, potentially enabling many directional walkers driven by a length-switching engine. The model reproduces the experimental data of the walker, and identifies its performance-limiting factors. The model also captures features common to the underlying design principle, including counterintuitive performance-construction relations that are explained by detailed balance, entropy production, and bias cancellation. While indicating a low directional fidelity for the present walker, the model suggests the possibility of improving the fidelity above 90% by a more powerful engine, which may be an improved version of the present engine or an entirely new engine motif, thanks to the flexible design principle. The model is readily adaptable to aid these experimental developments towards high-performance molecular walkers.

  4. A design principle underlying the paradoxical roles of E3 ubiquitin ligases

    PubMed Central

    Lee, Daewon; Kim, Minjin; Cho, Kwang-Hyun

    2014-01-01

    E3 ubiquitin ligases are important cellular components that determine the specificity of proteolysis in the ubiquitin-proteasome system. However, an increasing number of studies have indicated that E3 ubiquitin ligases also participate in transcription. Intrigued by the apparently paradoxical functions of E3 ubiquitin ligases in both proteolysis and transcriptional activation, we investigated the underlying design principles using mathematical modeling. We found that the antagonistic functions integrated in E3 ubiquitin ligases can prevent any undesirable sustained activation of downstream genes when E3 ubiquitin ligases are destabilized by unexpected perturbations. Interestingly, this design principle of the system is similar to the operational principle of a safety interlock device in engineering systems, which prevents a system from abnormal operation unless stability is guaranteed. PMID:24994517

  5. The principle of parallelism in the design of studies to estimate treatment effects.

    PubMed

    Reichardt, Charles S

    2006-03-01

    An effect is a function of a cause as well as of 4 other factors: recipient, setting, time, and outcome variable. The principle of parallelism states that if a design option exists for any 1 of these 4 factors, a parallel option exists for each of the others. For example, effects are often estimated by drawing a comparison across recipients who receive different treatments. The principle of parallelism implies that an effect can also be estimated by drawing a comparison across settings, times, or outcome variables. Typologies of methodological options are derived from the principle of parallelism. The typologies can help researchers recognize a broader set of options than they would otherwise and thereby improve the quality of research designs. ((c) 2006 APA, all rights reserved).

  6. A design principle underlying the paradoxical roles of E3 ubiquitin ligases

    NASA Astrophysics Data System (ADS)

    Lee, Daewon; Kim, Minjin; Cho, Kwang-Hyun

    2014-07-01

    E3 ubiquitin ligases are important cellular components that determine the specificity of proteolysis in the ubiquitin-proteasome system. However, an increasing number of studies have indicated that E3 ubiquitin ligases also participate in transcription. Intrigued by the apparently paradoxical functions of E3 ubiquitin ligases in both proteolysis and transcriptional activation, we investigated the underlying design principles using mathematical modeling. We found that the antagonistic functions integrated in E3 ubiquitin ligases can prevent any undesirable sustained activation of downstream genes when E3 ubiquitin ligases are destabilized by unexpected perturbations. Interestingly, this design principle of the system is similar to the operational principle of a safety interlock device in engineering systems, which prevents a system from abnormal operation unless stability is guaranteed.

  7. Four principles for user interface design of computerised clinical decision support systems.

    PubMed

    Kanstrup, Anne Marie; Christiansen, Marion Berg; Nøhr, Christian

    2011-01-01

    The paper presents results from a design research project of a user interface (UI) for a Computerised Clinical Decision Support System (CDSS). The ambition has been to design Human-Computer Interaction (HCI) that can minimise medication errors. Through an iterative design process a digital prototype for prescription of medicine has been developed. This paper presents results from the formative evaluation of the prototype conducted in a simulation laboratory with ten participating physicians. Data from the simulation is analysed by use of theory on how users perceive information. The conclusion is a model, which sum up four principles of interaction for design of CDSS. The four principles for design of user interfaces for CDSS are summarised as four A's: All in one, At a glance, At hand and Attention. The model emphasises integration of all four interaction principles in the design of user interfaces for CDSS, i.e. the model is an integrated model which we suggest as a guide for interaction design when working with preventing medication errors.

  8. Three Design Principles of Language: The Search for Parsimony in Redundancy

    ERIC Educational Resources Information Center

    Beekhuizen, Barend; Bod, Rens; Zuidema, Willem

    2013-01-01

    In this paper we present three design principles of language--experience, heterogeneity and redundancy--and present recent developments in a family of models incorporating them, namely Data-Oriented Parsing/Unsupervised Data-Oriented Parsing. Although the idea of some form of redundant storage has become part and parcel of parsing technologies and…

  9. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Sustainable principles for siting, design and construction. 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise...

  10. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Sustainable principles for siting, design and construction. 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise...

  11. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Sustainable principles for siting, design and construction. 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise...

  12. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Sustainable principles for siting, design and construction. 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise...

  13. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Sustainable principles for siting, design and construction. 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise...

  14. Key principles to guide development of consumer medicine information--content analysis of information design texts.

    PubMed

    Raynor, David K; Dickinson, David

    2009-04-01

    Effective written consumer medicines information is essential to support safe and effective medicine taking, but the wording and layout of currently provided materials do not meet patients' needs. To identify principles from the wider discipline of information design for use by health professionals when developing or assessing written drug information for patients. Six experts in information design nominated texts on best practice in information design applicable to consumer medicines information. A content analysis identified key principles that were tabulated to bring out key themes. Six texts that met the inclusion criteria, were identified, and content analysis indentified 4 themes: words, type, lines, and layout. Within these main themes, there were 24 subthemes. Selected principles relating to these subthemes were: use short familiar words, short sentences, and short headings that stand out from the text; use a conversational tone of voice, addressing the reader as "you"; use a large type size while retaining sufficient white space; use bullet points to organize lists; use unjustified text (ragged right) and bold, lower-case text for emphasis. Pictures or graphics do not necessarily improve a document. Applying the good information design principles identified to written consumer medicines information could support health professionals when developing and assessing drug information for patients.

  15. Seven Principles of Effective Case Design for a Problem-Based Curriculum.

    ERIC Educational Resources Information Center

    Dolmans, Diana H. J. M.; Snellen-Balendong, Hetty; Wolfhagen, Ineke H. A. P.; van der Vleuten, Cees P. M.

    1997-01-01

    Lends support to the idea that the quality of the cases used in problem-based learning affects the nature of student learning in this context. Outlines seven principles adapted from research on learning and cognition that can help guide case design. Contains 22 references. (DDR)

  16. Teacher Viewpoints of Instructional Design Principles for Visuals in a Middle School Math Curriculum

    ERIC Educational Resources Information Center

    Clinton, Virginia; Cooper, Jennifer L.

    2015-01-01

    Instructional design principles for visuals in student materials have been developed through findings based on student-level measures. However, teacher viewpoints may be a rich source of information to better understand how visuals can be optimized for student learning. This study's purpose is to examine teacher viewpoints on visuals. In a…

  17. Applying Principles of Collaboration to Videodisc Design: Profile of a Successful Project.

    ERIC Educational Resources Information Center

    Campbell-Bonar, Katy; Grisdale, Louise

    1991-01-01

    Discusses the collaborative team approach to instructional design. Collaborative principles are explained, and a collaborative project between the Faculty of Education at the University of Alberta and the Edmonton Public Schools is described that resulted in an interactive videodisc that could be used for preservice and inservice teacher…

  18. "Citizen Jane": Rethinking Design Principles for Closing the Gender Gap in Computing.

    ERIC Educational Resources Information Center

    Raphael, Chad

    This paper identifies three rationales in the relevant literature for closing the gender gap in computing: economic, cultural and political. Each rationale implies a different set of indicators of present inequalities, disparate goals for creating equality, and distinct principles for software and web site design that aims to help girls overcome…

  19. Creating, Evaluating, and Improving Humorous Cartoons Related to Design Principles for Gifted Education Programs

    ERIC Educational Resources Information Center

    Rule, Audrey C.; Schneider, Jean S.

    2009-01-01

    Humor through cartoons is an interesting way to engage students in learning course content. The purpose of this study was to document the process of graduate student-made cartoons that portrayed content about principles of designing gifted education programs. Seventeen graduate students enrolled in an introductory gifted education course…

  20. Three Design Principles of Language: The Search for Parsimony in Redundancy

    ERIC Educational Resources Information Center

    Beekhuizen, Barend; Bod, Rens; Zuidema, Willem

    2013-01-01

    In this paper we present three design principles of language--experience, heterogeneity and redundancy--and present recent developments in a family of models incorporating them, namely Data-Oriented Parsing/Unsupervised Data-Oriented Parsing. Although the idea of some form of redundant storage has become part and parcel of parsing technologies and…

  1. Successfully Teaching Biblical Languages Online at the Seminary Level: Guiding Principles of Course Design and Delivery

    ERIC Educational Resources Information Center

    Harlow, Joel

    2007-01-01

    Reformed Theological Seminary's Virtual Campus has successfully taught the biblical languages online since 1999. This article describes the theoretical principles that underlie the design and asynchronous delivery of online Greek and Hebrew to part-time adult distance students. The structure and administration of the courses is discussed, as well…

  2. Accessible by Design: Applying UDL Principles in a First Year Undergraduate Course

    ERIC Educational Resources Information Center

    Kumar, Kari Lynne; Wideman, Maureen

    2014-01-01

    This article presents a case study of a technology-enhanced face-to-face health sciences course in which the principles of Universal Design for Learning (UDL) were applied. Students were offered a variety of means of representation, engagement, and expression throughout the course, and were surveyed and interviewed at the end of the term to…

  3. [Principles of design of neural-network analog-to-digital converters of bioelectric signals].

    PubMed

    Loktiukhin, V N; Chelebaev, S V

    2007-01-01

    A design principle and a procedure for synthesis of neural-network analog-to-digital converters of bioelectric signals are suggested. An example of implementation of an FPGA-based neural-network converter for classification of bioparameters is presented.

  4. Using Design Principles to Foster Understanding of Complex Health Concepts in Consumer Informatics Tools

    PubMed Central

    Misra, Rupananda; Mark, Jessica H.; Khan, Sharib; Kukafka, Rita

    2010-01-01

    Consumer health informatics tools can only be effective if patients comprehend their content. Optimal design may foster better patient comprehension and health literacy, which can improve health outcomes. We developed a patient-centric decision aid, Tailored Lifestyle Conversations (TLC), to help patients comprehend behavioral risks and set behavior change priorities for reducing risk of cardiovascular disease. The TLC decision aid was developed using a design framework based on Gestalt Principles of Perception. Further iteration was informed by qualitative user feedback. Preliminary analysis showed that the TLC decision aid helped patients understand their risk and supported their decisions on health behavior change. We identified design elements that supported patient comprehension, and other elements that were not effective, to inform iterative revision. This paper describes an effective methodology for the development of consumer health informatics tools that includes grounding in design principles complemented by iterative revision based on user testing and feedback. PMID:21347027

  5. First principles design of a core bioenergetic transmembrane electron-transfer protein.

    PubMed

    Goparaju, Geetha; Fry, Bryan A; Chobot, Sarah E; Wiedman, Gregory; Moser, Christopher C; Leslie Dutton, P; Discher, Bohdana M

    2016-05-01

    Here we describe the design, Escherichia coli expression and characterization of a simplified, adaptable and functionally transparent single chain 4-α-helix transmembrane protein frame that binds multiple heme and light activatable porphyrins. Such man-made cofactor-binding oxidoreductases, designed from first principles with minimal reference to natural protein sequences, are known as maquettes. This design is an adaptable frame aiming to uncover core engineering principles governing bioenergetic transmembrane electron-transfer function and recapitulate protein archetypes proposed to represent the origins of photosynthesis. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Using design principles to foster understanding of complex health concepts in consumer informatics tools.

    PubMed

    Misra, Rupananda; Mark, Jessica H; Khan, Sharib; Kukafka, Rita

    2010-11-13

    Consumer health informatics tools can only be effective if patients comprehend their content. Optimal design may foster better patient comprehension and health literacy, which can improve health outcomes. We developed a patient-centric decision aid, Tailored Lifestyle Conversations (TLC), to help patients comprehend behavioral risks and set behavior change priorities for reducing risk of cardiovascular disease. The TLC decision aid was developed using a design framework based on Gestalt Principles of Perception. Further iteration was informed by qualitative user feedback. Preliminary analysis showed that the TLC decision aid helped patients understand their risk and supported their decisions on health behavior change. We identified design elements that supported patient comprehension, and other elements that were not effective, to inform iterative revision. This paper describes an effective methodology for the development of consumer health informatics tools that includes grounding in design principles complemented by iterative revision based on user testing and feedback.

  7. First principles design of a core bioenergetic transmembrane electron-transfer protein

    SciTech Connect

    Goparaju, Geetha; Fry, Bryan A.; Chobot, Sarah E.; Wiedman, Gregory; Moser, Christopher C.; Leslie Dutton, P.; Discher, Bohdana M.

    2016-05-01

    Here we describe the design, Escherichia coli expression and characterization of a simplified, adaptable and functionally transparent single chain 4-α-helix transmembrane protein frame that binds multiple heme and light activatable porphyrins. Such man-made cofactor-binding oxidoreductases, designed from first principles with minimal reference to natural protein sequences, are known as maquettes. This design is an adaptable frame aiming to uncover core engineering principles governing bioenergetic transmembrane electron-transfer function and recapitulate protein archetypes proposed to represent the origins of photosynthesis. This article is part of a Special Issue entitled Biodesign for Bioenergetics — the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  8. Optimal input design for aircraft parameter estimation using dynamic programming principles

    NASA Technical Reports Server (NTRS)

    Klein, Vladislav; Morelli, Eugene A.

    1990-01-01

    A new technique was developed for designing optimal flight test inputs for aircraft parameter estimation experiments. The principles of dynamic programming were used for the design in the time domain. This approach made it possible to include realistic practical constraints on the input and output variables. A description of the new approach is presented, followed by an example for a multiple input linear model describing the lateral dynamics of a fighter aircraft. The optimal input designs produced by the new technique demonstrated improved quality and expanded capability relative to the conventional multiple input design method.

  9. Optimal input design for aircraft parameter estimation using dynamic programming principles

    NASA Technical Reports Server (NTRS)

    Klein, Vladislav; Morelli, Eugene A.

    1990-01-01

    A new technique was developed for designing optimal flight test inputs for aircraft parameter estimation experiments. The principles of dynamic programming were used for the design in the time domain. This approach made it possible to include realistic practical constraints on the input and output variables. A description of the new approach is presented, followed by an example for a multiple input linear model describing the lateral dynamics of a fighter aircraft. The optimal input designs produced by the new technique demonstrated improved quality and expanded capability relative to the conventional multiple input design method.

  10. Optimal Input Design for Aircraft Parameter Estimation using Dynamic Programming Principles

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.; Klein, Vladislav

    1990-01-01

    A new technique was developed for designing optimal flight test inputs for aircraft parameter estimation experiments. The principles of dynamic programming were used for the design in the time domain. This approach made it possible to include realistic practical constraints on the input and output variables. A description of the new approach is presented, followed by an example for a multiple input linear model describing the lateral dynamics of a fighter aircraft. The optimal input designs produced by the new technique demonstrated improved quality and expanded capability relative to the conventional multiple input design method.

  11. High-throughput spectrometer designs in a compact form-factor: principles and applications

    NASA Astrophysics Data System (ADS)

    Norton, S. M.

    2013-05-01

    Many compact, portable Raman spectrometers have entered the market in the past few years with applications in narcotics and hazardous material identification, as well as verification applications in pharmaceuticals and security screening. Often, the required compact form-factor has forced designers to sacrifice throughput and sensitivity for portability and low-cost. We will show that a volume phase holographic (VPH)-based spectrometer design can achieve superior throughput and thus sensitivity over conventional Czerny-Turner reflective designs. We will look in depth at the factors influencing throughput and sensitivity and illustrate specific VPH-based spectrometer examples that highlight these design principles.

  12. Applications of Evolutionary Algorithms to Electromagnetic Materials Characterization and Design Problems

    NASA Astrophysics Data System (ADS)

    Frasch, Jonathan Lemoine

    Determining the electrical permittivity and magnetic permeability of materials is an important task in electromagnetics research. The method using reflection and transmission scattering parameters to determine these constants has been widely employed for many years, ever since the work of Nicolson, Ross, and Weir in the 1970's. For general materials that are homogeneous, linear, and isotropic, the method they developed (the NRW method) works very well and provides an analytical solution. For materials which possess a metal backing or are applied as a coating to a metal surface, it can be difficult or even impossible to obtain a transmission measurement, especially when the coating is thin. In such a circumstance, it is common to resort to a method which uses two reflection type measurements. There are several such methods for free-space measurements, using multiple angles or polarizations for example. For waveguide measurements, obtaining two independent sources of information from which to extract two complex parameters can be a challenge. This dissertation covers three different topics. Two of these involve different techniques to characterize conductor-backed materials, and the third proposes a method for designing synthetic validation standards for use with standard NRW measurements. All three of these topics utilize modal expansions of electric and magnetic fields to analyze propagation in stepped rectangular waveguides. Two of the projects utilize evolutionary algorithms (EA) to design waveguide structures. These algorithms were developed specifically for these projects and utilize fairly recent innovations within the optimization community. The first characterization technique uses two different versions of a single vertical step in the waveguide. Samples to be tested lie inside the steps with the conductor reflection plane behind them. If the two reflection measurements are truly independent it should be possible to recover the values of two complex

  13. Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries.

    PubMed

    Sevov, Christo S; Brooner, Rachel E M; Chénard, Etienne; Assary, Rajeev S; Moore, Jeffrey S; Rodríguez-López, Joaquín; Sanford, Melanie S

    2015-11-18

    The integration of renewable energy sources into the electric grid requires low-cost energy storage systems that mediate the variable and intermittent flux of energy associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale energy storage applications. Because the cost of the system scales with mass, the electroactive materials must have a low equivalent weight (ideally 150 g/(mol·e(-)) or less), and must function with low molecular weight supporting electrolytes such as LiBF4. However, soluble anolyte materials that undergo reversible redox processes in the presence of Li-ion supports are rare. We report the evolutionary design of a series of pyridine-based anolyte materials that exhibit up to two reversible redox couples at low potentials in the presence of Li-ion supporting electrolytes. A combination of cyclic voltammetry of anolyte candidates and independent synthesis of their corresponding charged-states was performed to rapidly screen for the most promising candidates. Results of this workflow provided evidence for possible decomposition pathways of first-generation materials and guided synthetic modifications to improve the stability of anolyte materials under the targeted conditions. This iterative process led to the identification of a promising anolyte material, N-methyl 4-acetylpyridinium tetrafluoroborate. This compound is soluble in nonaqueous solvents, is prepared in a single synthetic step, has a low equivalent weight of 111 g/(mol·e(-)), and undergoes two reversible 1e(-) reductions in the presence of LiBF4 to form reduced products that are stable over days in solution.

  14. Evolutionary and Comparative Genomics to Drive Rational Drug Design, with Particular Focus on Neuropeptide Seven-Transmembrane Receptors

    PubMed Central

    Furlong, Michael; Seong, Jae Young

    2017-01-01

    Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples. PMID:28035082

  15. Operationalising the Lean principles in maternity service design using 3P methodology.

    PubMed

    Smith, Iain

    2016-01-01

    The last half century has seen significant changes to Maternity services in England. Though rates of maternal and infant mortality have fallen to very low levels, this has been achieved largely through hospital admission. It has been argued that maternity services may have become over-medicalised and service users have expressed a preference for more personalised care. NHS England's national strategy sets out a vision for a modern maternity service that continues to deliver safe care whilst also adopting the principles of personalisation. Therefore, there is a need to develop maternity services that balance safety with personal choice. To address this challenge, a maternity unit in North East England considered improving their service through refurbishment or building new facilities. Using a design process known as the production preparation process (or 3P), the Lean principles of understanding user value, mapping value-streams, creating flow, developing pull processes and continuous improvement were applied to the design of a new maternity department. Multiple stakeholders were engaged in the design through participation in a time-out (3P) workshop in which an innovative pathway and facility for maternity services were co-designed. The team created a hybrid model that they described as "wrap around care" in which the Lean concept of pull was applied to create a service and facility design in which expectant mothers were put at the centre of care with clinicians, skills, equipment and supplies drawn towards them in line with acuity changes as needed. Applying the Lean principles using the 3P method helped stakeholders to create an innovative design in line with the aspirations and objectives of the National Maternity Review. The case provides a practical example of stakeholders applying the Lean principles to maternity services and demonstrates the potential applicability of the Lean 3P approach to design healthcare services in line with policy requirements.

  16. Operationalising the Lean principles in maternity service design using 3P methodology

    PubMed Central

    Smith, Iain

    2016-01-01

    The last half century has seen significant changes to Maternity services in England. Though rates of maternal and infant mortality have fallen to very low levels, this has been achieved largely through hospital admission. It has been argued that maternity services may have become over-medicalised and service users have expressed a preference for more personalised care. NHS England's national strategy sets out a vision for a modern maternity service that continues to deliver safe care whilst also adopting the principles of personalisation. Therefore, there is a need to develop maternity services that balance safety with personal choice. To address this challenge, a maternity unit in North East England considered improving their service through refurbishment or building new facilities. Using a design process known as the production preparation process (or 3P), the Lean principles of understanding user value, mapping value-streams, creating flow, developing pull processes and continuous improvement were applied to the design of a new maternity department. Multiple stakeholders were engaged in the design through participation in a time-out (3P) workshop in which an innovative pathway and facility for maternity services were co-designed. The team created a hybrid model that they described as “wrap around care” in which the Lean concept of pull was applied to create a service and facility design in which expectant mothers were put at the centre of care with clinicians, skills, equipment and supplies drawn towards them in line with acuity changes as needed. Applying the Lean principles using the 3P method helped stakeholders to create an innovative design in line with the aspirations and objectives of the National Maternity Review. The case provides a practical example of stakeholders applying the Lean principles to maternity services and demonstrates the potential applicability of the Lean 3P approach to design healthcare services in line with policy requirements

  17. Applying design principles to fusion reactor configurations for propulsion in space

    NASA Technical Reports Server (NTRS)

    Carpenter, Scott A.; Deveny, Marc E.; Schulze, Norman R.

    1993-01-01

    We applied three design principles (DPs) to adapt and optimize three candidate-terrestrial-fusion-reactor configurations for propulsion in space. The three design principles are: (1) provide maximum direct access to space for waste radiation, (2) operate components as passive radiators to minimize cooling-system mass, and (3) optimize the plasma fuel, fuel mix, and temperature for best specific Jet power. The three candidate-terrestrial-fusion-reactor configurations are: (1) the thermal-barrier-tandem-mirror (TBTM), (2) field-reversed-mirror (FRM), and (3) levitated-dipole-field (LDF). The resulting three candidate-space-fusion-propulsion systems have their initial-mass-to-LEO minimized and their specific jet power and reusability maximized. We performed a preliminary rating of these configurations and concluded that the leading engineering-design solution to space fusion propulsion is a modified TBTM that we call the Mirror Fusion Propulsion System.

  18. Rational, computer-enabled peptide drug design: principles, methods, applications and future directions.

    PubMed

    Diller, David J; Swanson, Jon; Bayden, Alexander S; Jarosinski, Mark; Audie, Joseph

    2015-01-01

    Peptides provide promising templates for developing drugs to occupy a middle space between small molecules and antibodies and for targeting 'undruggable' intracellular protein-protein interactions. Importantly, rational or in cerebro design, especially when coupled with validated in silico tools, can be used to efficiently explore chemical space and identify islands of 'drug-like' peptides to satisfy diverse drug discovery program objectives. Here, we consider the underlying principles of and recent advances in rational, computer-enabled peptide drug design. In particular, we consider the impact of basic physicochemical properties, potency and ADME/Tox opportunities and challenges, and recently developed computational tools for enabling rational peptide drug design. Key principles and practices are spotlighted by recent case studies. We close with a hypothetical future case study.

  19. Open-Shell-Character-Based Molecular Design Principles: Applications to Nonlinear Optics and Singlet Fission.

    PubMed

    Nakano, Masayoshi

    2017-01-01

    Open-shell character, e. g., diradical character, is a quantum chemically well-defined quantity in ground-state molecular systems, which is not an observable but can quantify the degree of effective bond weakness in the chemical sense or electron correlation strength in the physical sense. Because this quantity also correlates to specific excited states, physicochemical properties concerned with those states are expected to strongly correlate to the open-shell character. This feature enables us to open a new path to revealing the mechanism of these properties as well as to realizing new design principles for efficient functional molecular systems. This account explains the open-shell-character-based molecular design principles and introduces their applications to the rational design of highly efficient nonlinear optical and singlet fission molecular systems. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Zebrafish housing systems: a review of basic operating principles and considerations for design and functionality.

    PubMed

    Lawrence, Christian; Mason, Timothy

    2012-01-01

    The strategies for housing zebrafish used in biomedical research have evolved considerably over the past three decades. To keep pace with the rapid expansion and development of the zebrafish model system, the field has generally moved from keeping fish at the level of aquarium hobbyist to that of industrialized, recirculating aquaculture. Numerous commercial system vendors now offer increasingly sophisticated housing systems based on design principles that maximize the number of animals that can be housed in a given space footprint, and they are thus able to support large and diverse research programs. This review is designed to provide managers, lab animal veterinarians, investigators, and other parties responsible for care and use of these animals with a comprehensive overview of the basic operating and design principles of zebrafish housing systems. This information can be used to help plan the construction of new facilities and/or the upgrade and maintenance of existing operations.