Science.gov

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 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

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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)

  8. 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.

  9. 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

  10. 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…

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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…

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  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. 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…

  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. 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,…

  11. 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.

  12. 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…

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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…

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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…

  4. 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…

  5. 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.

  6. 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

  7. 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…

  8. 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.

  9. 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.

  10. 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…

  11. 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…

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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…

  17. 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…

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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…

  8. 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…

  9. 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.

  10. 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…

  11. 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.

  12. 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.

  13. 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…

  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. 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.

  16. 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…

  17. 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…

  18. 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

  19. 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

  20. 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.

  1. 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…

  2. 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…

  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. 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.

  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. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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…

  13. 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,…

  14. 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)

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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…

  5. 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…

  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. 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…

  8. 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…

  9. 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.

  10. 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…

  11. 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)

  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. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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…

  9. 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)

  10. 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.

  11. 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,…

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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)

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  19. 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

  20. 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…

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. [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.

  13. 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.

  14. 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…

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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…

  20. 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…

  1. 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…

  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. 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.

  6. 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.

  7. 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.

  8. 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…

  9. 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.

  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. 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.

  12. 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.

  13. 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…

  14. 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,…

  15. 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.

  16. 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.

  17. 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

  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. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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…

  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. 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.

  6. 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…

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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…

  13. 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.

  14. 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.

  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. 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.

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. 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

  3. Designing an Advanced Instructional Design Advisor: Principles of Instructional Design. Volume 2

    DTIC Science & Technology

    1991-05-01

    Computers in Human Behavior , 5, 167-174. Palincsar, A.S. and Brown...strategies to improve creativity. Computers in Human Behavior , 4, 23-28. Reigeluth, C.M. (1983) (Ed.) Instructional Design Theories and Models...Tennyson, R.D., Thurlow, R., and Breuer, K. (1988). Problem oriented simulations to develop and improve higher thinking strategies. Computers in Human Behavior ,

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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…

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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...

  11. 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...

  12. 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,…

  13. 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…

  14. 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...

  15. 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.

  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. 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.

  18. 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.

  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. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... 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 Residential Buildings. § 435.6 Sustainable principles for siting, design and construction....

  16. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... 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 Residential Buildings. § 435.6 Sustainable principles for siting, design and construction....

  17. 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...

  18. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... 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 Residential Buildings. § 435.6 Sustainable principles for siting, design and construction....

  19. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... 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 Residential Buildings. § 435.6 Sustainable principles for siting, design and construction....

  20. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... 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 Residential Buildings. § 435.6 Sustainable principles for siting, design and construction....

  1. 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...

  2. 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...

  3. 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…

  4. 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…

  5. 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…

  6. "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…

  7. [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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Zebrafish Housing Systems: A Review of Basic Operating Principles and Considerations for Design and Functionality

    PubMed Central

    Lawrence, Christian; Mason, Timothy

    2015-01-01

    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. PMID:23382349

  19. A multi-purpose SAIL demonstrator design and its principle experimental verification

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Yan, Aimin; Xu, Nan; Wang, Lijuan; Luan, Zhu; Sun, Jianfeng; Liu, Liren

    2009-08-01

    A fully 2-D synthetic aperture imaging ladar (SAIL) demonstrator is designed and being fabricated to experimentally investigate and theoretically analyze the beam diffraction properties, antenna function, imaging resolution and signal processing algorithm of SAIL. The design details of the multi-purpose SAIL demonstrator are given and, as the first phase, a laboratory-scaled SAIL system based on bulk optical elements has been built to verify the principle of design, which is similar in construction to the demonstrator but without the major antenna telescope. The system has the aperture diameter of about 1mm and the target distance of 3.2m.

  20. Using the uncertainty principle to design simple interactions for targeted self-assembly.

    PubMed

    Edlund, E; Lindgren, O; Jacobi, M Nilsson

    2013-07-14

    We present a method that systematically simplifies isotropic interactions designed for targeted self-assembly. The uncertainty principle is used to show that an optimal simplification is achieved by a combination of heat kernel smoothing and Gaussian screening of the interaction potential in real and reciprocal space. We use this method to analytically design isotropic interactions for self-assembly of complex lattices and of materials with functional properties. The derived interactions are simple enough to narrow the gap between theory and experimental implementation of theory based designed self-assembling materials.

  1. Incorporating Eco-Evolutionary Processes into Population Models:Design and Applications

    EPA Science Inventory

    Eco-evolutionary population models are powerful new tools for exploring howevolutionary processes influence plant and animal population dynamics andvice-versa. The need to manage for climate change and other dynamicdisturbance regimes is creating a demand for the incorporation of...

  2. Accelerated materials design of fast oxygen ionic conductors based on first principles calculations

    NASA Astrophysics Data System (ADS)

    He, Xingfeng; Mo, Yifei

    Over the past decades, significant research efforts have been dedicated to seeking fast oxygen ion conductor materials, which have important technological applications in electrochemical devices such as solid oxide fuel cells, oxygen separation membranes, and sensors. Recently, Na0.5Bi0.5TiO3 (NBT) was reported as a new family of fast oxygen ionic conductor. We will present our first principles computation study aims to understand the O diffusion mechanisms in the NBT material and to design this material with enhanced oxygen ionic conductivity. Using the NBT materials as an example, we demonstrate the computation capability to evaluate the phase stability, chemical stability, and ionic diffusion of the ionic conductor materials. We reveal the effects of local atomistic configurations and dopants on oxygen diffusion and identify the intrinsic limiting factors in increasing the ionic conductivity of the NBT materials. Novel doping strategies were predicted and demonstrated by the first principles calculations. In particular, the K doped NBT compound achieved good phase stability and an order of magnitude increase in oxygen ionic conductivity of up to 0.1 S cm-1 at 900 K compared to the experimental Mg doped compositions. Our results provide new avenues for the future design of the NBT materials and demonstrate the accelerated design of new ionic conductor materials based on first principles techniques. This computation methodology and workflow can be applied to the materials design of any (e.g. Li +, Na +) fast ion-conducting materials.

  3. The Effect of Content Representation Design Principles on Users' Intuitive Beliefs and Use of E-Learning Systems

    ERIC Educational Resources Information Center

    Al-Samarraie, Hosam; Selim, Hassan; Zaqout, Fahed

    2016-01-01

    A model is proposed to assess the effect of different content representation design principles on learners' intuitive beliefs about using e-learning. We hypothesized that the impact of the representation of course contents is mediated by the design principles of alignment, quantity, clarity, simplicity, and affordance, which influence the…

  4. EVOLUTIONARY FOUNDATIONS FOR MOLECULAR MEDICINE

    PubMed Central

    Nesse, Randolph M.; Ganten, Detlev; Gregory, T. Ryan; Omenn, Gilbert S.

    2015-01-01

    Evolution has long provided a foundation for population genetics, but many major advances in evolutionary biology from the 20th century are only now being applied in molecular medicine. They include the distinction between proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are further transforming evolutionary biology and creating yet more opportunities for progress at the interface of evolution 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 others to speed the development of evolutionary molecular medicine. PMID:22544168

  5. Design principles of regulatory networks: searching for the molecular algorithms of the cell.

    PubMed

    Lim, Wendell A; Lee, Connie M; Tang, Chao

    2013-01-24

    A challenge in biology is to understand how complex molecular networks in the cell execute sophisticated regulatory functions. Here we explore the idea that there are common and general principles that link network structures to biological functions, principles that constrain the design solutions that evolution can converge upon for accomplishing a given cellular task. We describe approaches for classifying networks based on abstract architectures and functions, rather than on the specific molecular components of the networks. For any common regulatory task, can we define the space of all possible molecular solutions? Such inverse approaches might ultimately allow the assembly of a design table of core molecular algorithms that could serve as a guide for building synthetic networks and modulating disease networks.

  6. Using engineering control principles to inform the design of adaptive interventions: a conceptual introduction.

    PubMed

    Rivera, Daniel E; Pew, Michael D; Collins, Linda M

    2007-05-01

    The goal of this paper is to describe the role that control engineering principles can play in developing and improving the efficacy of adaptive, time-varying interventions. It is demonstrated that adaptive interventions constitute a form of feedback control system in the context of behavioral health. Consequently, drawing from ideas in control engineering has the potential to significantly inform the analysis, design, and implementation of adaptive interventions, leading to improved adherence, better management of limited resources, a reduction of negative effects, and overall more effective interventions. This article illustrates how to express an adaptive intervention in control engineering terms, and how to use this framework in a computer simulation to investigate the anticipated impact of intervention design choices on efficacy. The potential benefits of operationalizing decision rules based on control engineering principles are particularly significant for adaptive interventions that involve multiple components or address co-morbidities, situations that pose significant challenges to conventional clinical practice.

  7. Design Principles of Regulatory Networks: Searching for the Molecular Algorithms of the Cell

    PubMed Central

    Lim, Wendell A.; Lee, Connie M.; Tang, Chao

    2013-01-01

    A challenge in biology is to understand how complex molecular networks in the cell execute sophisticated regulatory functions. Here we explore the idea that there are common and general principles that link network structures to biological functions, principles that constrain the design solutions that evolution can converge upon for accomplishing a given cellular task. We describe approaches for classifying networks based on abstract architectures and functions, rather than on the specific molecular components of the networks. For any common regulatory task, can we define the space of all possible molecular solutions? Such inverse approaches might ultimately allow the assembly of a design table of core molecular algorithms that could serve as a guide for building synthetic networks and modulating disease networks. PMID:23352241

  8. Design principles for problem-driven learning laboratories in biomedical engineering education.

    PubMed

    Newstetter, Wendy C; Behravesh, Essy; Nersessian, Nancy J; Fasse, Barbara B

    2010-10-01

    This article presents a translational model of curricular design in which findings from investigating learning in university BME research laboratories (in vivo sites) are translated into design principles for educational laboratories (in vitro sites). Using these principles, an undergraduate systems physiology lab class was redesigned and then evaluated in a comparative study. Learning outcomes in a control section that utilized a technique-driven approach were compared to those found in an experimental class that embraced a problem-driven approach. Students in the experimental section demonstrated increased learning gains even when they were tasked with solving complex, ill structured problems on the bench top. The findings suggest the need for the development of new, more authentic models of learning that better approximate practices from industry and academia.

  9. Application of Instructional Design Principles in Developing an Online Information Literacy Curriculum.

    PubMed

    Mi, Misa

    2016-01-01

    An online information literacy curriculum was developed as an intervention to engage students in independent study and self-assessment of their learning needs and learning outcomes, develop proficiency in information skills, and foster lifelong learning. This column demonstrates how instructional design principles were applied to create the learning experiences integrated into various courses of the medical curriculum to promote active learning of information skills and maximize self-directed learning outcomes for lifelong learning.

  10. Principles of Good School Building Design. School Buildings Planning, Design, and Construction Series No. 3.

    ERIC Educational Resources Information Center

    Odell, John H.

    A school construction guide offers key personnel in school development projects information on the complex task of master planning and construction of schools in Australia. This chapter of the guide provides advice on school building design issues, such as the fundamentals of good design and designs that accommodate change, issues affecting…

  11. 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

    The application of fusion power to space propulsion requires rethinking the engineering-design solution to controlled-fusion energy. Whereas the unit cost of electricity (COE) drives the engineering-design solution for utility-based fusion reactor configurations; initial mass to low earth orbit (IMLEO), specific jet power (kW(thrust)/kg(engine)), and reusability drive the engineering-design solution for successful application of fusion power to space propulsion. We applied three design principles (DP's) to adapt and optimize three candidate-terrestrial-fusion-reactor configurations for propulsion in space. The three design principles are: provide maximum direct access to space for waste radiation, operate components as passive radiators to minimize cooling-system mass, and optimize the plasma fuel, fuel mix, and temperature for best specific jet power. The three candidate terrestrial fusion reactor configurations are: the thermal barrier tandem mirror (TBTM), field reversed mirror (FRM), and levitated dipole field (LDF). The resulting three candidate space fusion propulsion systems have their IMLEO 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 (MFPS).

  12. Structural principles for computational and de novo design of 4Fe-4S metalloproteins.

    PubMed

    Nanda, Vikas; Senn, Stefan; Pike, Douglas H; Rodriguez-Granillo, Agustina; Hansen, Will A; Khare, Sagar D; Noy, Dror

    2016-05-01

    Iron-sulfur centers in metalloproteins can access multiple oxidation states over a broad range of potentials, allowing them to participate in a variety of electron transfer reactions and serving as catalysts for high-energy redox processes. The nitrogenase FeMoCO cluster converts di-nitrogen to ammonia in an eight-electron transfer step. The 2(Fe4S4) containing bacterial ferredoxin is an evolutionarily ancient metalloprotein fold and is thought to be a primordial progenitor of extant oxidoreductases. Controlling chemical transformations mediated by iron-sulfur centers such as nitrogen fixation, hydrogen production as well as electron transfer reactions involved in photosynthesis are of tremendous importance for sustainable chemistry and energy production initiatives. As such, there is significant interest in the design of iron-sulfur proteins as minimal models to gain fundamental understanding of complex natural systems and as lead-molecules for industrial and energy applications. Herein, we discuss salient structural characteristics of natural iron-sulfur proteins and how they guide principles for design. Model structures of past designs are analyzed in the context of these principles and potential directions for enhanced designs are presented, and new areas of iron-sulfur protein design are proposed. This article is part of a Special issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, protein networks, edited by Ronald L. Koder and J.L Ross Anderson.

  13. Using articulation and inscription as catalysts for reflection: Design principles for reflective inquiry

    NASA Astrophysics Data System (ADS)

    Loh, Ben Tun-Bin

    2003-07-01

    The demand for students to engage in complex student-driven and information-rich inquiry investigations poses challenges to existing learning environments. Students are not familiar with this style of work, and lack the skills, tools, and expectations it demands, often forging blindly forward in the investigation. If students are to be successful, they need to learn to be reflective inquirers, periodically stepping back from an investigation to evaluate their work. The fundamental goal of my dissertation is to understand how to design learning environments to promote and support reflective inquiry. I have three basic research questions: how to define this mode of work, how to help students learn it, and understanding how it facilitates reflection when enacted in a classroom. I take an exploratory approach in which, through iterative cycles of design, development, and reflection, I develop principles of design for reflective inquiry, instantiate those principles in the design of a software environment, and test that software in the context of classroom work. My work contributes to the understanding of reflective inquiry in three ways: First, I define a task model that describes the kinds of operations (cognitive tasks) that students should engage in as reflective inquirers. These operations are defined in terms of two basic tasks: articulation and inscription, which serve as catalysts for externalizing student thinking as objects of and triggers for reflection. Second, I instantiate the task model in the design of software tools (the Progress Portfolio). And, through proof of concept pilot studies, I examine how the task model and tools helped students with their investigative classroom work. Finally, I take a step back from these implementations and articulate general design principles for reflective inquiry with the goal of informing the design of other reflective inquiry learning environments. There are three design principles: (1) Provide a designated work space

  14. Designing nanomaterials to maximize performance and minimize undesirable implications guided by the Principles of Green Chemistry.

    PubMed

    Gilbertson, Leanne M; Zimmerman, Julie B; Plata, Desiree L; Hutchison, James E; Anastas, Paul T

    2015-08-21

    The Twelve Principles of Green Chemistry were first published in 1998 and provide a framework that has been adopted not only by chemists, but also by design practitioners and decision-makers (e.g., materials scientists and regulators). The development of the Principles was initially motivated by the need to address decades of unintended environmental pollution and human health impacts from the production and use of hazardous chemicals. Yet, for over a decade now, the Principles have been applied to the synthesis and production of engineered nanomaterials (ENMs) and the products they enable. While the combined efforts of the global scientific community have led to promising advances in the field of nanotechnology, there remain significant research gaps and the opportunity to leverage the potential global economic, societal and environmental benefits of ENMs safely and sustainably. As such, this tutorial review benchmarks the successes to date and identifies critical research gaps to be considered as future opportunities for the community to address. A sustainable material design framework is proposed that emphasizes the importance of establishing structure-property-function (SPF) and structure-property-hazard (SPH) relationships to guide the rational design of ENMs. The goal is to achieve or exceed the functional performance of current materials and the technologies they enable, while minimizing inherent hazard to avoid risk to human health and the environment at all stages of the life cycle.

  15. Novel Principles and Techniques to Create a Natural Design in Female Hairline Correction Surgery

    PubMed Central

    2015-01-01

    Abstract Background: Female hairline correction surgery is becoming increasingly popular. However, no guidelines or methods of female hairline design have been introduced to date. Methods: The purpose of this study was to create an initial framework based on the novel principles of female hairline design and then use artistic ability and experience to fine tune this framework. An understanding of the concept of 5 areas (frontal area, frontotemporal recess area, temporal peak, infratemple area, and sideburns) and 5 points (C, A, B, T, and S) is required for female hairline correction surgery (the 5A5P principle). The general concepts of female hairline correction surgery and natural design methods are, herein, explained with a focus on the correlations between these 5 areas and 5 points. Results: A natural and aesthetic female hairline can be created with application of the above-mentioned concepts. Conclusion: The 5A5P principle of forming the female hairline is very useful in female hairline correction surgery. PMID:26894014

  16. Designing and implementing reflective practice programs--key principles and considerations.

    PubMed

    Parrish, Dominique R; Crookes, Kay

    2014-05-01

    This paper reports on an educational evaluation study that sought to identify key principles that could inform the design and implementation of undergraduate nursing reflection programs and thereby enhance the potential that nursing students will develop sound reflective practice. Semi-structured interviews were conducted with nursing graduates to explore their perceptions of an undergraduate Bachelor of Nursing reflection subject and explicate the factors that could enhance the implementation of this subject. Subsequent validation and refinement of these factors was managed by correlating the factors with students' qualitative feedback, gathered through a formal subject evaluation of the undergraduate reflective practice subject. The correlation analysis, ascertained three principles that are posited as highly significant in the design and implementation of undergraduate reflective practice nursing programs. These principles, which are explained in this paper, despite being conceptualised in an Australian University have relevance and are appropriate across national and discipline boundaries and could be used in the design and implementation of any reflection subject, particularly those in undergraduate programs.

  17. Designing a parallel evolutionary algorithm for inferring gene networks on the cloud computing environment

    PubMed Central

    2014-01-01

    Background To improve the tedious task of reconstructing gene networks through testing experimentally the possible interactions between genes, it becomes a trend to adopt the automated reverse engineering procedure instead. Some evolutionary algorithms have been suggested for deriving network parameters. However, to infer large networks by the evolutionary algorithm, it is necessary to address two important issues: premature convergence and high computational cost. To tackle the former problem and to enhance the performance of traditional evolutionary algorithms, it is advisable to use parallel model evolutionary algorithms. To overcome the latter and to speed up the computation, it is advocated to adopt the mechanism of cloud computing as a promising solution: most popular is the method of MapReduce programming model, a fault-tolerant framework to implement parallel algorithms for inferring large gene networks. Results This work presents a practical framework to infer large gene networks, by developing and parallelizing a hybrid GA-PSO optimization method. Our parallel method is extended to work with the Hadoop MapReduce programming model and is executed in different cloud computing environments. To evaluate the proposed approach, we use a well-known open-source software GeneNetWeaver to create several yeast S. cerevisiae sub-networks and use them to produce gene profiles. Experiments have been conducted and the results have been analyzed. They show that our parallel approach can be successfully used to infer networks with desired behaviors and the computation time can be largely reduced. Conclusions Parallel population-based algorithms can effectively determine network parameters and they perform better than the widely-used sequential algorithms in gene network inference. These parallel algorithms can be distributed to the cloud computing environment to speed up the computation. By coupling the parallel model population-based optimization method and the parallel

  18. Comparative respiratory morphology: themes and principles in the design and construction of the gas exchangers.

    PubMed

    Maina, J N

    2000-02-15

    Along the evolutionary continuum, a kaleidoscope of gas exchangers has evolved from the simple cell membrane of the primeval unicells. The most momentous events in this process were: the intensification of molecular oxygen in the biosphere and its appropriation into aerobic metabolism, the rise of multicellular organisms, the development of a circulatory system and carrier pigments in blood, the advocacy of air breathing, adoption of suctional breathing, and the shift to endothermy. To satisfy species-specific needs for oxygen, some constraints were overcome through transactions that obliged certain compromises and trade-offs. Optimal designs of the gas exchangers for particular phylogenetic levels of development, habitat, and lifestyle have developed only so far as to satisfy prescribed needs. The efficiency of the human lung, for example, falls well below those of certain taxa that are considered to be relatively "less advanced." Utilizing different resources and strategies, in fascinating processes of conformity, different groups of animals have developed similar respiratory structures. In most cases, the analogy reflects evolutionary convergence in response to corresponding selective pressures rather than common ancestry. Anat Rec (New Anat) 261:25-44, 2000.

  19. New class of planar ferroelectric Mott insulators via first-principles design

    SciTech Connect

    Kim, Chanul; Park, Hyowon; Marianetti, Chris A.

    2015-12-11

    which is not common in known materials. Here we use first-principles calculations to design layered double perovskite oxides AABBO6 which achieve the aforementioned properties in the context of Mott insulators. In our design rules, the gap is dictated by B/B electronegativity difference in a Mott state, while the polarization is obtained via nominal d0 filling on the B-site, A-type cations bearing lone-pair electrons, and A = A size mismatch. Successful execution is demonstrated in BaBiCuVO6, BaBiNiVO6, BaLaCuVO6, and PbLaCuVO6.

  20. Designation and Implementation of Microcomputer Principle and Interface Technology Virtual Experimental Platform Website

    NASA Astrophysics Data System (ADS)

    Gao, JinYue; Tang, Yin

    This paper explicitly discusses the designation and implementation thought and method of Microcomputer Principle and Interface Technology virtual experimental platform website construction. The instructional design of this platform mainly follows with the students-oriented constructivism learning theory, and the overall structure is subject to the features of teaching aims, teaching contents and interactive methods. Virtual experiment platform production and development should fully take the characteristics of network operation into consideration and adopt relevant technologies to improve the effect and speed of network software application in internet.

  1. Comparing State-of-the-Art Evolutionary Multi-Objective Algorithms for Long-Term Groundwater Monitoring Design

    NASA Astrophysics Data System (ADS)

    Reed, P. M.; Kollat, J. B.

    2005-12-01

    This study demonstrates the effectiveness of a modified version of Deb's Non-Dominated Sorted Genetic Algorithm II (NSGAII), which the authors have named the Epsilon-Dominance Non-Dominated Sorted Genetic Algorithm II (Epsilon-NSGAII), at solving a four objective long-term groundwater monitoring (LTM) design test case. The Epsilon-NSGAII incorporates prior theoretical competent evolutionary algorithm (EA) design concepts and epsilon-dominance archiving to improve the original NSGAII's efficiency, reliability, and ease-of-use. This algorithm eliminates much of the traditional trial-and-error parameterization associated with evolutionary multi-objective optimization (EMO) through epsilon-dominance archiving, dynamic population sizing, and automatic termination. The effectiveness and reliability of the new algorithm is compared to the original NSGAII as well as two other benchmark multi-objective evolutionary algorithms (MOEAs), the Epsilon-Dominance Multi-Objective Evolutionary Algorithm (Epsilon-MOEA) and the Strength Pareto Evolutionary Algorithm 2 (SPEA2). These MOEAs have been selected because they have been demonstrated to be highly effective at solving numerous multi-objective problems. The results presented in this study indicate superior performance of the Epsilon-NSGAII in terms of the hypervolume indicator, unary Epsilon-indicator, and first-order empirical attainment function metrics. In addition, the runtime metric results indicate that the diversity and convergence dynamics of the Epsilon-NSGAII are competitive to superior relative to the SPEA2, with both algorithms greatly outperforming the NSGAII and Epsilon-MOEA in terms of these metrics. The improvements in performance of the Epsilon-NSGAII over its parent algorithm the NSGAII demonstrate that the application of Epsilon-dominance archiving, dynamic population sizing with archive injection, and automatic termination greatly improve algorithm efficiency and reliability. In addition, the usability of

  2. Structural principles for computational and de novo design of 4Fe-4S metalloproteins

    PubMed Central

    Nanda, Vikas; Senn, Stefan; Pike, Douglas H.; Rodriguez-Granillo, Agustina; Hansen, Will; Khare, Sagar D.; Noy, Dror

    2017-01-01

    Iron-sulfur centers in metalloproteins can access multiple oxidation states over a broad range of potentials, allowing them to participate in a variety of electron transfer reactions and serving as catalysts for high-energy redox processes. The nitrogenase FeMoCO cluster converts di-nitrogen to ammonia in an eight-electron transfer step. The 2(Fe4S4) containing bacterial ferredoxin is an evolutionarily ancient metalloprotein fold and is thought to be a primordial progenitor of extant oxidoreductases. Controlling chemical transformations mediated by iron-sulfur centers such as nitrogen fixation, hydrogen production as well as electron transfer reactions involved in photosynthesis are of tremendous importance for sustainable chemistry and energy production initiatives. As such, there is significant interest in the design of iron-sulfur proteins as minimal models to gain fundamental understanding of complex natural systems and as lead-molecules for industrial and energy applications. Herein, we discuss salient structural characteristics of natural iron-sulfur proteins and how they guide principles for design. Model structures of past designs are analyzed in the context of these principles and potential directions for enhanced designs are presented, and new areas of iron-sulfur protein design are proposed. PMID:26449207

  3. Designing health care environments: Part I. Basic concepts, principles, and issues related to evidence-based design.

    PubMed

    Cesario, Sandra K

    2009-06-01

    A 2001 Institute of Medicine report captured the nation's attention regarding the dangers that can result from the health care environment. This report, fueled by the need for new facilities to be constructed, led to an explosion of research that now links the physical structure and design of health care facilities to the health and well-being of patients, nurses, other health care workers, and visitors. Continuing nursing education that highlights the importance of evidence-based design has been associated with measurable improvement in health care facilities' clinical outcomes, economic performance, employee productivity, customer satisfaction, and cultural congruency. Three major categories of outcomes can be impacted by evidence-based design: stress reduction, safety, and overall health care quality and ecology. In this article, Part I of a two-part series, the basic concepts, principles, and issues related to evidence-based design are introduced. Part II will describe continuing education programs available for nurses.

  4. Novice Designers' Myths about Usability Sessions: Guidelines To Implementing User-Centered Design Principles.

    ERIC Educational Resources Information Center

    Sugar, William A.

    1999-01-01

    Details myths that illustrate novice instructional designers' perspectives on usability sessions and their users. Then offers suggestions for integrating creativity and developing enhanced perspective-taking. Two tables list the myths and guidelines, and potential effects of usability-session guidelines on novice designers' myths are charted. (AEF)

  5. Human Factors Principles in Design of Computer-Mediated Visualization for Robot Missions

    SciTech Connect

    David I Gertman; David J Bruemmer

    2008-12-01

    With increased use of robots as a resource in missions supporting countermine, improvised explosive devices (IEDs), and chemical, biological, radiological nuclear and conventional explosives (CBRNE), fully understanding the best means by which to complement the human operator’s underlying perceptual and cognitive processes could not be more important. Consistent with control and display integration practices in many other high technology computer-supported applications, current robotic design practices rely highly upon static guidelines and design heuristics that reflect the expertise and experience of the individual designer. In order to use what we know about human factors (HF) to drive human robot interaction (HRI) design, this paper reviews underlying human perception and cognition principles and shows how they were applied to a threat detection domain.

  6. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas

    PubMed Central

    Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

    2014-01-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas. PMID:25081193

  7. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas.

    PubMed

    Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

    2014-08-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas.

  8. Design Principles for Rapid Prototyping Forces Sensors using 3D Printing

    PubMed Central

    Kesner, Samuel B.; Howe, Robert D.

    2011-01-01

    Force sensors provide critical information for robot manipulators, manufacturing processes, and haptic interfaces. Commercial force sensors, however, are generally not adapted to specific system requirements, resulting in sensors with excess size, cost, and fragility. To overcome these issues, 3D printers can be used to create components for the quick and inexpensive development of force sensors. Limitations of this rapid prototyping technology, however, require specialized design principles. In this paper, we discuss techniques for rapidly developing simple force sensors, including selecting and attaching metal flexures, using inexpensive and simple displacement transducers, and 3D printing features to aid in assembly. These design methods are illustrated through the design and fabrication of a miniature force sensor for the tip of a robotic catheter system. The resulting force sensor prototype can measure forces with an accuracy of as low as 2% of the 10 N measurement range. PMID:21874102

  9. Design principles for clinical efficacy of cancer nanomedicine: a look into the basics

    PubMed Central

    Sengupta, Shiladitya; Kulkarni, Ashish

    2013-01-01

    With the advances in cancer nanomedicine, there is an increasing expectation for clinical translation. However, what are the parameters of a nanomedicine that will define clinical success, which will be measured by increased efficacy and not just ease of delivery or reduction in toxicity? This perspective builds on a fundamental study by Stefanick et al on the significance of the right design principles in the engineering of a nanomedicine, such as peptide-PEG-linker length and ligand density in cellular uptake of liposomal nanoparticles. The perspective addresses additional design parameters that can potentially facilitate clinical translation as well as how emerging insights into tumor biology will inspire the next generation cancer nanomedicines. SUMMARY: As we rapidly race cancer nanomedicines towards the clinics, what are the fundamental design parameters that will influence outcome? What can we learn from antibody-drug conjugates that will facilitate nanomedicines passing the 'efficacy test'? This perspective addresses some of these questions. PMID:23607425

  10. Design Principles for Rapid Prototyping Forces Sensors using 3D Printing.

    PubMed

    Kesner, Samuel B; Howe, Robert D

    2011-07-21

    Force sensors provide critical information for robot manipulators, manufacturing processes, and haptic interfaces. Commercial force sensors, however, are generally not adapted to specific system requirements, resulting in sensors with excess size, cost, and fragility. To overcome these issues, 3D printers can be used to create components for the quick and inexpensive development of force sensors. Limitations of this rapid prototyping technology, however, require specialized design principles. In this paper, we discuss techniques for rapidly developing simple force sensors, including selecting and attaching metal flexures, using inexpensive and simple displacement transducers, and 3D printing features to aid in assembly. These design methods are illustrated through the design and fabrication of a miniature force sensor for the tip of a robotic catheter system. The resulting force sensor prototype can measure forces with an accuracy of as low as 2% of the 10 N measurement range.

  11. Plant cell walls throughout evolution: towards a molecular understanding of their design principles.

    PubMed

    Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

    2009-01-01

    Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche, which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

  12. Plant cell walls throughout evolution: towards a molecular understanding of their design principles

    SciTech Connect

    Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

    2009-02-16

    Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche,which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

  13. Supporting Teachers in Designing CSCL Activities: A Case Study of Principle-Based Pedagogical Patterns in Networked Second Language Classrooms

    ERIC Educational Resources Information Center

    Wen, Yun; Looi, Chee-Kit; Chen, Wenli

    2012-01-01

    This paper proposes the identification and use of principle-based pedagogical patterns to help teachers to translate design principles into actionable teaching activities, and to scaffold student learning with sufficient flexibility and creativity. A set of pedagogical patterns for networked Second language (L2) learning, categorized and…

  14. 41 CFR 102-76.55 - What sustainable development principles must Federal agencies apply to the siting, design, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Construction Sustainable Development § 102-76.55 What sustainable development principles must... Acquisition,” Federal agencies must apply sustainable development principles to the siting, design, and... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What...

  15. Design Principles for High School Engineering Design Challenges: Experiences from High School Science Classrooms

    ERIC Educational Resources Information Center

    Schunn, Christian

    2011-01-01

    At the University of Pittsburgh, the author and his colleagues have been exploring a range of approaches to design challenges for implementation in high school science classrooms. In general, their approach has always involved students working during class time over the course of many weeks. So, their understanding of what works must be…

  16. Message Design for Mobile Learning: Learning Theories, Human Cognition and Design Principles

    ERIC Educational Resources Information Center

    Wang, Minjuan; Shen, Ruimin

    2012-01-01

    The demands of an increasingly knowledge-based society and the dramatic advances in mobile phone technology are combining to spur the growth of mobile learning (mLearning). However, for mLearning to attain its full potential, it is essential to develop pedagogy and instructional design tailored to the needs of this new learning environment. At…

  17. A game plan: Gamification design principles in mHealth applications for chronic disease management.

    PubMed

    Miller, Aaron S; Cafazzo, Joseph A; Seto, Emily

    2016-06-01

    Effective chronic disease management is essential to improve positive health outcomes, and incentive strategies are useful in promoting self-care with longevity. Gamification, applied with mHealth (mobile health) applications, has the potential to better facilitate patient self-management. This review article addresses a knowledge gap around the effective use of gamification design principles, or mechanics, in developing mHealth applications. Badges, leaderboards, points and levels, challenges and quests, social engagement loops, and onboarding are mechanics that comprise gamification. These mechanics are defined and explained from a design and development perspective. Health and fitness applications with gamification mechanics include: bant which uses points, levels, and social engagement, mySugr which uses challenges and quests, RunKeeper which uses leaderboards as well as social engagement loops and onboarding, Fitocracy which uses badges, and Mango Health, which uses points and levels. Specific design considerations are explored, an example of the efficacy of a gamified mHealth implementation in facilitating improved self-management is provided, limitations to this work are discussed, a link between the principles of gaming and gamification in health and wellness technologies is provided, and suggestions for future work are made. We conclude that gamification could be leveraged in developing applications with the potential to better facilitate self-management in persons with chronic conditions.

  18. Design principles and issues of rights expression languages for digital rights management

    NASA Astrophysics Data System (ADS)

    Wang, Xin

    2005-07-01

    Digital rights management (DRM) provides a unified approach to specifying, interpreting, enforcing and managing digital rights throughout the entire life cycle of digital assets. Using a declarative rights expression language (REL) for specifying rights and conditions in the form of licenses, as opposite to some other approaches (such as data structures and imperative languages), has been considered and adopted as a superior technology for implementing effective, interoperable and scalable DRM systems. This paper discusses some principles and issues for designing RELs, based on the experiences of developing a family of REL"s (DPRL, XrML 1.x, XrML 2.0 and MPEG REL). It starts with an overview of a family tree of the past and current REL"s, and their development history, followed by an analysis of their data models and a comparison with access-control oriented models. It then presents a number of primary design principles such as syntactic and semantic un-ambiguity, system interoperability, expressiveness in supporting business models and future extensibility, and discusses a number of key design issues such as maintaining stateful information, multi-tier issuance of rights, meta rights, identification of individual and aggregate objects, late-binding of to-beidentified entities, as well as some advanced ones on revocation and delegation of rights. The paper concludes with some remarks on REL profiling and extension for specific application domains.

  19. Design and Evaluation of Potentiometric Principles for Bladder Volume Monitoring: A Preliminary Study

    PubMed Central

    Chen, Shih-Ching; Hsieh, Tsung-Hsun; Fan, Wen-Jia; Lai, Chien-Hung; Chen, Chun-Lung; Wei, Wei-Feng; Peng, Chih-Wei

    2015-01-01

    Recent advances in microelectronics and wireless transmission technology have led to the development of various implantable sensors for real-time monitoring of bladder conditions. Although various sensing approaches for monitoring bladder conditions were reported, most such sensors have remained at the laboratory stage due to the existence of vital drawbacks. In the present study, we explored a new concept for monitoring the bladder capacity on the basis of potentiometric principles. A prototype of a potentiometer module was designed and fabricated and integrated with a commercial wireless transmission module and power unit. A series of in vitro pig bladder experiments was conducted to determine the best design parameters for implementing the prototype potentiometric device and to prove its feasibility. We successfully implemented the potentiometric module in a pig bladder model in vitro, and the error of the accuracy of bladder volume detection was <±3%. Although the proposed potentiometric device was built using a commercial wireless module, the design principles and animal experience gathered from this research can serve as a basis for developing new implantable bladder sensors in the future. PMID:26039421

  20. From First Principles Design to Realization of Bimetallic Catalysts for Enhanced Selectivity

    SciTech Connect

    Lobo, Raul F.; Crooks, Richard M.; Mavrikakis, Manos

    2014-04-08

    “Catalysis by design” has been a dream for decades. To specify the composition and structure of matter to effect a desired catalytic transformation with desired and predicted rate and selectivity remains a monumental challenge, especially in heterogeneous catalysis. Our research thrusts have been chosen not only for their practical and scientific relevance, e.g. for more efficient and sustainable chemicals and fuels production, but also because they provide a foundation for developing and exploring broadly applicable principles and strategies for catalyst design.

  1. Automatic feature design for optical character recognition using an evolutionary search procedure.

    PubMed

    Stentiford, F W

    1985-03-01

    An automatic evolutionary search is applied to the problem of feature extraction in an OCR application. A performance measure based on feature independence is used to generate features which do not appear to suffer from peaking effects [17]. Features are extracted from a training set of 30 600 machine printed 34 class alphanumeric characters derived from British mail. Classification results on the training set and a test set of 10 200 characters are reported for an increasing number of features. A 1.01 percent forced decision error rate is obtained on the test data using 316 features. The hardware implementation should be cheap and fast to operate. The performance compares favorably with current low cost OCR page readers.

  2. Space Science Education with Mathematica: Interactive Design Modular Space Station Structures with Computer Algebra: Principles, Functional Units, Motions, Examples

    NASA Astrophysics Data System (ADS)

    Kabai, S.; Miyazaki, K.; Bérczi, Sz.

    2002-03-01

    We worked out a course with interactive Mathematica program to design Space Stations with icosahedral/dodecahedral tiling system of subunits, with motions for observing maneuvering space. Constraints/principles from geometry are also discussed.

  3. Chemical Frustration. A Design Principle for the Discovery of New Complex Alloy and Intermetallic Phases, Final Report

    SciTech Connect

    Fredrickson, Daniel C

    2015-06-23

    Final technical report for "Chemical Frustration: A Design Principle for the Discovery of New Complex Alloy and Intermetallic Phases" funded by the Office of Science through the Materials Chemistry Program of the Office of Basic Energy Sciences.

  4. Magnetoelectic multiferroic superlattices and interfaces: Designing spintronic materials from first principles

    NASA Astrophysics Data System (ADS)

    Zanolli, Zeila

    2015-03-01

    The research challenges of the near and far future in electronics focus on the quest for new materials and novel device concepts to achieve low energy consumption, increased reliability and high device density. These can be obtained by designing active elements and interconnects whose operating principle is not (only) based on the electron charge but on the spin degree of freedom of the electron. The nanoscopic size of the materials calls for atomistic and parameter free (ab initio) simulations, which have proven to be crucial in achieving the necessary accuracy and predictive power. Materials which present a coupling between ferroelectricity and magnetism, i.e. magnetoelectric (ME) multiferroics, have been proposed as fundamental building blocks for spintronic devices. However ferroelectricity and magnetism are often exclusive or weakly coupled in bulk. In this talk, we will discuss how superlattices of perovskites can be designed from first principles to achieve strongly coupled ME and, hence, achieve control the weak magnetization via an electric field. Most important, advanced epitaxial techniques allow one to actually grow such magnetoelectric superlattices. Another route to optimize spintronic devices is to exploit the unique electronic and transport properties of Carbon-based nanomaterials. The latter present spin diffusion lengths up to 100 μm and high electron velocity. However, a large spin diffusion length comes at the price of small Spin Orbit coupling, which limits the possibility of manipulating electrons via an external applied field. Further, to achieve graphene-based devices one also needs to open its vanishing electronic gap. We use first principle techniques to show that placing graphene on a ME substrate can overcome these limitations by inducing magnetism and opening an electronic band-gap in the hybrid organic-multiferroic material. Z.Z. acknowledges EC support under the Marie-Curie IEF (PIEF-Ga-2011-300036), computational resources from the

  5. 41 CFR 102-76.55 - What sustainable development principles must Federal agencies apply to the siting, design, and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 76-DESIGN AND CONSTRUCTION Design... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What sustainable development principles must Federal agencies apply to the siting, design, and construction of new...

  6. 41 CFR 102-76.55 - What sustainable development principles must Federal agencies apply to the siting, design, and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 76-DESIGN AND CONSTRUCTION Design... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false What sustainable development principles must Federal agencies apply to the siting, design, and construction of new...

  7. 41 CFR 102-76.55 - What sustainable development principles must Federal agencies apply to the siting, design, and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 76-DESIGN AND CONSTRUCTION Design... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What sustainable development principles must Federal agencies apply to the siting, design, and construction of new...

  8. 41 CFR 102-76.55 - What sustainable development principles must Federal agencies apply to the siting, design, and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 76-DESIGN AND CONSTRUCTION Design... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What sustainable development principles must Federal agencies apply to the siting, design, and construction of new...

  9. Top 10 principles for designing healthy coastal ecosystems like the Salish Sea

    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.

  10. Sensor of total hip arthoplasty wear designed on principle of scanning profilometry

    NASA Astrophysics Data System (ADS)

    Rössler, Tomas; Mandat, Dusan; Gallo, Jiri; Hrabovsky, Miroslav; Pochmon, Michal; Havranek, Vitezslav

    2008-12-01

    Total hip arthroplasty significantly improves the quality of life in majority of patients with osteoarthritis. However, prosthetic wear is a problem because of inducing the development of aseptic loosening and periprosthetic osteolysis which needs the revision surgery. Thus, the polyethylene wear measurement is the central to contemporary orthopaedics and this interesting has encouraged the development and improvement of both radiologic (in vivo) and non-radiologic (in vitro) methods for polyethylene wear quantification. The principles of polyethylene liner wear measurements are predominantly geometric; nevertheless, the realization of individual types of in vivo measurements brings with it the necessity of many simplifications and compromising steps to acquire approximately accurate values. In fact, the volumetric wear can be obtained by mathematical conversion based on the most linear shift of femoral head in the cup. However, such approach is understood to be somewhat insufficient. Our ongoing research pointed to the development of optical non-contact method for wear measurement and its results are introduced in this paper including the methodology designed for the usability validation of the method for the given purpose and the description of sensor, its principle, technical realization, design and parameters.

  11. Design principle for absorption enhancement with nanoparticles in thin-film silicon solar cells

    NASA Astrophysics Data System (ADS)

    Xu, Yuanpei; Xuan, Yimin

    2015-07-01

    The use of nanoparticles in solar cells has created many controversies. In this paper, different mechanisms of nanoparticles with different materials with diameters varying from 50 to 200 nm, surface coverage at 5, 20, and 60 %, and different locations are analyzed systematically for efficient light trapping in a thin-film c-Si solar cell. Mie theory and the finite difference time domain method are used for analysis to give a design principle with nanoparticles for the solar cell application. Metals exhibit plasmonic resonances and angular scattering, while dielectrics show anti-reflection and scattering in the incident direction. A table is given to summarize the advantages and disadvantages in different conditions. The silicon absorption enhancement with nanoparticles on top is mainly in the shorter wavelengths below 700 nm, and both Al and SiO2 nanoparticles with diameter around 100 nm show the most significant enhancement. The silicon absorption enhancement with embedded nanoparticles takes place in the longer wavelengths over 700 nm, and Ag and SiO2 nanoparticles with larger diameter around 200 nm perform better. However, the light absorbed by Ag nanoparticles will be converted to heat and will lead to decrease in cell efficiency; hence, the choice of metallic nanoparticles in applications to solar cells should be carefully considered. The design principle proposed in this work gives a guideline by choosing reasonable parameters for the different requirements in the application of thin-film solar cells.

  12. Design and Properties Prediction of AMCO3F by First-Principles Calculations.

    PubMed

    Tian, Meng; Gao, Yurui; Ouyang, Chuying; Wang, Zhaoxiang; Chen, Liquan

    2017-04-10

    Computer simulation accelerates the rate of identification and application of new materials. To search for new materials to meet the increasing demands of secondary batteries with higher energy density, the properties of some transition-metal fluorocarbonates ([CO3F](3-)) were simulated in this work as cathode materials for Li- and Na-ion batteries based on first-principles calculations. These materials were designed by substituting the K(+) ions in KCuCO3F with Li(+) or Na(+) ions and the Cu(2+) ions with transition-metal ions such as Fe(2+), Co(2+), Ni(2+), and Mn(2+) ions, respectively. The phase stability, electronic conductivity, ionic diffusion, and electrochemical potential of these materials were calculated by first-principles calculations. After taking comprehensive consideration of the kinetic and thermodynamic properties, LiCoCO3F and LiFeCO3F are believed to be promising novel cathode materials in all of the calculated AMCO3F (A = Li and Na; M = Fe, Mn, Co, and Ni). These results will help the design and discovery of new materials for secondary batteries.

  13. Top 10 principles for designing healthy coastal ecosystems like the Salish Sea.

    PubMed

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

    2008-12-01

    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.

  14. Investigations into the design principles in the chemotactic behavior of Escherichia coli.

    PubMed

    Kim, Tae-Hwan; Jung, Sung Hoon; Cho, Kwang-Hyun

    2008-01-01

    Inspired by the recent studies on the analysis of biased random walk behavior of Escherichia coli[Passino, K.M., 2002. Biomimicry of bacterial foraging for distributed optimization and control. IEEE Control Syst. Mag. 22 (3), 52-67; Passino, K.M., 2005. Biomimicry for Optimization, Control and Automation. Springer-Verlag, pp. 768-798; Liu, Y., Passino, K.M., 2002. Biomimicry of social foraging bacteria for distributed optimization: models, principles, and emergent behaviors. J. Optim. Theory Appl. 115 (3), 603-628], we have developed a model describing the motile behavior of E. coli by specifying some simple rules on the chemotaxis. Based on this model, we have analyzed the role of some key parameters involved in the chemotactic behavior to unravel the underlying design principles. By investigating the target tracking capability of E. coli in a maze through computer simulations, we found that E. coli clusters can be controlled as target trackers in a complex micro-scale-environment. In addition, we have explored the dynamical characteristics of this target tracking mechanism through perturbation of parameters under noisy environments. It turns out that the E. coli chemotaxis mechanism might be designed such that it is sensitive enough to efficiently track the target and also robust enough to overcome environmental noises.

  15. Design principles for high efficiency small-grain polysilicon solar cells, with supporting experimental studies

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.; Sah, C. T.

    1982-01-01

    Design principles suggested here aim toward high conversion efficiency (greater than 15 percent) in polysilicon cells. The principles seek to decrease the liabilities of both intragranular and grain-boundary-surface defects. The advantages of a phosphorus atom concentration gradient in a thin (less than 50 microns) base of a p(+)/n(x)/n(+) drift-field solar cell, which produces favorable gradients in chemical potential, minority-carrier mobility and diffusivity, and recombination lifetime (via phosphorus gettering) are suggested. The degrading effects of grain boundaries are reduced by these three gradients and by substituting atoms (P, H, F or Li) for vacancies on the grain-boundary surface. From recent experiments comes support for the benefits of P diffusion down grain boundaries and, for quasi-grain-boundary-free and related structures. New analytic solutions for the n(x)-base include the effect of a power-law dependence between P concentration and lifetime. These provide an upper-bound estimate on the open circuit voltage. Finite-difference numerical solutions of the six Shockley equations furnish complete information about all solar-cell parameters and add insight concerning design.

  16. Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory

    PubMed Central

    Marino, Kristen A.; Hinnemann, Berit; Carter, Emily A.

    2011-01-01

    To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are comprised. This feat is accomplished in part via the deposition of a multilayer, multicomponent thermal barrier coating (TBC), which lasts up to approximately 40,000 h before failing. Understanding failure mechanisms can aid in designing circumvention strategies. We review results of quantum mechanics calculations used to test hypotheses about impurities that harm TBCs and transition metal (TM) additives that render TBCs more robust. In particular, we discovered a number of roles that Pt and early TMs such as Hf and Y additives play in extending the lifetime of TBCs. Fundamental insight into the nature of the bonding created by such additives and its effect on high-temperature evolution of the TBCs led to design principles that can be used to create materials for even more efficient engines.

  17. A design principle of polymers processable into 2D homeotropic order

    PubMed Central

    Chen, Zhen; Chan, Yi-Tsu; Miyajima, Daigo; Kajitani, Takashi; Kosaka, Atsuko; Fukushima, Takanori; Lobez, Jose M.; Aida, Takuzo

    2016-01-01

    How to orient polymers homeotropically in thin films has been a long-standing issue in polymer science because polymers intrinsically prefer to lie down. Here we provide a design principle for polymers that are processable into a 2D homeotropic order. The key to this achievement was a recognition that cylindrical polymers can be designed to possess oppositely directed local dipoles in their cross-section, which possibly force polymers to tightly connect bilaterally, affording a 2D rectangular assembly. With a physical assistance of the surface grooves on Teflon sheets that sandwich polymer samples, homeotropic ordering is likely nucleated and gradually propagates upon hot-pressing towards the interior of the film. Consequently, the 2D rectangular lattice is constructed such that its b axis (side chains) aligns along the surface grooves, while its c axis (polymer backbone) aligns homeotropically on a Teflon sheet. This finding paves the way to molecularly engineered 2D polymers with anomalous functions. PMID:27897189

  18. The principle and main structure design on national database of poverty, environment, and development in China

    NASA Astrophysics Data System (ADS)

    Wang, Yingjie; Feng, Xiangfeng; Yu, Zhuoyuan; Cui, Jing

    2009-07-01

    Poverty is listed as the one of eight "Millennium Development Goals" by UN Summit. From 1978 to 2004, rural poverty population in China is cut to 26.1 million from 250 million. In order to support the decision maker to make nice planning in elimination of poverty and promotion of regional sustainable development in China, the GIS based systemic and comprehensive database for poverty, environment and development is proposed and designed in the paper. Additionally, the design principle and main content of the database is discussed by utilization modern technology, such as spatialtemporal and tree-ring data models for data structuring and coding, in order to represent current poverty status, spatial distribution and temporal variations, and to explore the relationship among poverty, environment and development ultimately.

  19. A design principle of polymers processable into 2D homeotropic order

    NASA Astrophysics Data System (ADS)

    Chen, Zhen; Chan, Yi-Tsu; Miyajima, Daigo; Kajitani, Takashi; Kosaka, Atsuko; Fukushima, Takanori; Lobez, Jose M.; Aida, Takuzo

    2016-11-01

    How to orient polymers homeotropically in thin films has been a long-standing issue in polymer science because polymers intrinsically prefer to lie down. Here we provide a design principle for polymers that are processable into a 2D homeotropic order. The key to this achievement was a recognition that cylindrical polymers can be designed to possess oppositely directed local dipoles in their cross-section, which possibly force polymers to tightly connect bilaterally, affording a 2D rectangular assembly. With a physical assistance of the surface grooves on Teflon sheets that sandwich polymer samples, homeotropic ordering is likely nucleated and gradually propagates upon hot-pressing towards the interior of the film. Consequently, the 2D rectangular lattice is constructed such that its b axis (side chains) aligns along the surface grooves, while its c axis (polymer backbone) aligns homeotropically on a Teflon sheet. This finding paves the way to molecularly engineered 2D polymers with anomalous functions.

  20. New class of planar ferroelectric Mott insulators via first-principles design

    NASA Astrophysics Data System (ADS)

    Kim, Chanul; Park, Hyowon; Marianetti, Chris A.

    2015-12-01

    The bulk photovoltaic effect requires a low electronic band gap (i.e., ≈1 -2 eV) and large electronic polarization, which is not common in known materials. Here we use first-principles calculations to design layered double perovskite oxides AA'BB'O6 which achieve the aforementioned properties in the context of Mott insulators. In our design rules, the gap is dictated by B/B' electronegativity difference in a Mott state, while the polarization is obtained via nominal d0 filling on the B-site, A-type cations bearing lone-pair electrons, and A ≠A' size mismatch. Successful execution is demonstrated in BaBiCuVO6, BaBiNiVO6, BaLaCuVO6, and PbLaCuVO6.

  1. Impact of first-principles properties of deuterium–tritium on inertial confinement fusion target designs

    SciTech Connect

    Hu, S. X.; Goncharov, V. N.; Boehly, T. R.; McCrory, R. L.; Skupsky, S.; Collins, L. A.; Kress, J. D.; Militizer, B.

    2015-04-20

    In this study, a comprehensive knowledge of the properties of high-energy-density plasmas is crucial to understanding and designing low-adiabat, inertial confinement fusion (ICF) implosions through hydrodynamic simulations. Warm-dense-matter (WDM) conditions are routinely accessed by low-adiabat ICF implosions, in which strong coupling and electron degeneracy often play an important role in determining the properties of warm dense plasmas. The WDM properties of deuterium–tritium (DT) mixtures and ablator materials, such as the equation of state, thermal conductivity, opacity, and stopping power, were usually estimated by models in hydro-codes used for ICF simulations. In these models, many-body and quantum effects were only approximately taken into account in the WMD regime. Moreover, the self-consistency among these models was often missing. To examine the accuracy of these models, we have systematically calculated the static, transport, and optical properties of warm dense DT plasmas, using first-principles (FP) methods over a wide range of densities and temperatures that cover the ICF “path” to ignition. These FP methods include the path-integral Monte Carlo (PIMC) and quantum-molecular dynamics (QMD) simulations, which treat electrons with many-body quantum theory. The first-principles equation-of-state table, thermal conductivities (KQMD), and first principles opacity table of DT have been self-consistently derived from the combined PIMC and QMD calculations. They have been compared with the typical models, and their effects to ICF simulations have been separately examined in previous publications. In this paper, we focus on their combined effects to ICF implosions through hydro-simulations using these FP-based properties of DT in comparison with the usual model simulations. We found that the predictions of ICF neutron yield could change by up to a factor of –2.5; the lower the adiabat of DT capsules, the more variations in hydro

  2. Impact of first-principles properties of deuterium–tritium on inertial confinement fusion target designs

    SciTech Connect

    Hu, S. X. Goncharov, V. N.; Boehly, T. R.; McCrory, R. L.; Skupsky, S.; Collins, L. A.; Kress, J. D.; Militzer, B.

    2015-05-15

    A comprehensive knowledge of the properties of high-energy-density plasmas is crucial to understanding and designing low-adiabat, inertial confinement fusion (ICF) implosions through hydrodynamic simulations. Warm-dense-matter (WDM) conditions are routinely accessed by low-adiabat ICF implosions, in which strong coupling and electron degeneracy often play an important role in determining the properties of warm dense plasmas. The WDM properties of deuterium–tritium (DT) mixtures and ablator materials, such as the equation of state, thermal conductivity, opacity, and stopping power, were usually estimated by models in hydro-codes used for ICF simulations. In these models, many-body and quantum effects were only approximately taken into account in the WMD regime. Moreover, the self-consistency among these models was often missing. To examine the accuracy of these models, we have systematically calculated the static, transport, and optical properties of warm dense DT plasmas, using first-principles (FP) methods over a wide range of densities and temperatures that cover the ICF “path” to ignition. These FP methods include the path-integral Monte Carlo (PIMC) and quantum-molecular dynamics (QMD) simulations, which treat electrons with many-body quantum theory. The first-principles equation-of-state table, thermal conductivities (κ{sub QMD}), and first principles opacity table of DT have been self-consistently derived from the combined PIMC and QMD calculations. They have been compared with the typical models, and their effects to ICF simulations have been separately examined in previous publications. In this paper, we focus on their combined effects to ICF implosions through hydro-simulations using these FP-based properties of DT in comparison with the usual model simulations. We found that the predictions of ICF neutron yield could change by up to a factor of ∼2.5; the lower the adiabat of DT capsules, the more variations in hydro-simulations. The FP

  3. Impact of first-principles properties of deuterium–tritium on inertial confinement fusion target designs

    DOE PAGES

    Hu, S. X.; Goncharov, V. N.; Boehly, T. R.; ...

    2015-04-20

    In this study, a comprehensive knowledge of the properties of high-energy-density plasmas is crucial to understanding and designing low-adiabat, inertial confinement fusion (ICF) implosions through hydrodynamic simulations. Warm-dense-matter (WDM) conditions are routinely accessed by low-adiabat ICF implosions, in which strong coupling and electron degeneracy often play an important role in determining the properties of warm dense plasmas. The WDM properties of deuterium–tritium (DT) mixtures and ablator materials, such as the equation of state, thermal conductivity, opacity, and stopping power, were usually estimated by models in hydro-codes used for ICF simulations. In these models, many-body and quantum effects were only approximatelymore » taken into account in the WMD regime. Moreover, the self-consistency among these models was often missing. To examine the accuracy of these models, we have systematically calculated the static, transport, and optical properties of warm dense DT plasmas, using first-principles (FP) methods over a wide range of densities and temperatures that cover the ICF “path” to ignition. These FP methods include the path-integral Monte Carlo (PIMC) and quantum-molecular dynamics (QMD) simulations, which treat electrons with many-body quantum theory. The first-principles equation-of-state table, thermal conductivities (KQMD), and first principles opacity table of DT have been self-consistently derived from the combined PIMC and QMD calculations. They have been compared with the typical models, and their effects to ICF simulations have been separately examined in previous publications. In this paper, we focus on their combined effects to ICF implosions through hydro-simulations using these FP-based properties of DT in comparison with the usual model simulations. We found that the predictions of ICF neutron yield could change by up to a factor of –2.5; the lower the adiabat of DT capsules, the more variations in hydro

  4. Bioinformatical parsing of folding-on-binding proteins reveals their compositional and evolutionary sequence design.

    PubMed

    Narasumani, Mohanalakshmi; Harrison, Paul M

    2015-12-18

    Intrinsic disorder occurs when (part of) a protein remains unfolded during normal functioning. Intrinsically-disordered regions can contain segments that 'fold on binding' to another molecule. Here, we perform bioinformatical parsing of human 'folding-on-binding' (FB) proteins, into four subsets: Ordered regions, FB regions, Disordered regions that surround FB regions ('Disordered-around-FB'), and Other-Disordered regions. We examined the composition and evolutionary behaviour (across vertebrate orthologs) of these subsets. From a convergence of three separate analyses, we find that for hydrophobicity, Ordered regions segregate from the other subsets, but the Ordered and FB regions group together as highly conserved, and the Disordered-around-FB and Other-Disordered regions as less conserved (with a lesser significant difference between Ordered and FB regions). FB regions are highly-conserved with net positive charge, whereas Disordered-around-FB have net negative charge and are relatively less hydrophobic than FB regions. Indeed, these Disordered-around-FB regions are excessively hydrophilic compared to other disordered regions generally. We describe how our results point towards a possible compositionally-based steering mechanism of folding-on-binding.

  5. The Spatial Vision Tree: A Generic Pattern Recognition Engine- Scientific Foundations, Design Principles, and Preliminary Tree Design

    NASA Technical Reports Server (NTRS)

    Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

    2010-01-01

    New foundational ideas are used to define a novel approach to generic visual pattern recognition. These ideas proceed from the starting point of the intrinsic equivalence of noise reduction and pattern recognition when noise reduction is taken to its theoretical limit of explicit matched filtering. This led us to think of the logical extension of sparse coding using basis function transforms for both de-noising and pattern recognition to the full pattern specificity of a lexicon of matched filter pattern templates. A key hypothesis is that such a lexicon can be constructed and is, in fact, a generic visual alphabet of spatial vision. Hence it provides a tractable solution for the design of a generic pattern recognition engine. Here we present the key scientific ideas, the basic design principles which emerge from these ideas, and a preliminary design of the Spatial Vision Tree (SVT). The latter is based upon a cryptographic approach whereby we measure a large aggregate estimate of the frequency of occurrence (FOO) for each pattern. These distributions are employed together with Hamming distance criteria to design a two-tier tree. Then using information theory, these same FOO distributions are used to define a precise method for pattern representation. Finally the experimental performance of the preliminary SVT on computer generated test images and complex natural images is assessed.

  6. Convergent setal morphology in sand-covering spiders suggests a design principle for particle capture.

    PubMed

    Duncan, Rebecca P; Autumn, Kellar; Binford, Greta J

    2007-12-22

    Sicarius and Homalonychus are unrelated, desert-dwelling spiders that independently evolved the ability to cover themselves in fine sand particles, making them cryptic against their background. Observations that particles associate with these spiders' setae inspired us to investigate the role of setal microstructure in particle capture and retention. Here we report that Sicarius and Homalonychus convergently evolved numerous high aspect ratio, flexible fibres that we call 'hairlettes' protruding from the setal shaft. We demonstrate that particles attach more densely to regions of Homalonychus with hairlettes than to other regions of the same animal where hairlettes are absent, and document close contact of hairlettes to sand particles that persists after applying force. Mathematical models further suggest that adhesion of hairlettes to sand particles is a sufficient mechanism of particle capture and retention. Together, these data provide the first evidence that hairlettes facilitate sand retention through intermolecular adhesion to particles. Their independent evolutionary origins in Sicarius and Homalonychus suggest that the unique setal structure is adaptive and represents a general biomechanical mechanism for sand capture to cuticle. This discovery has implications for the design of inventions inspired by this system, from camouflage to the management of granular systems.

  7. Towards first-principles molecular design of liquid crystal-based chemoresponsive systems

    NASA Astrophysics Data System (ADS)

    Roling, Luke T.; Scaranto, Jessica; Herron, Jeffrey A.; Yu, Huaizhe; Choi, Sangwook; Abbott, Nicholas L.; Mavrikakis, Manos

    2016-11-01

    Nematic liquid crystals make promising chemoresponsive systems, but their development is currently limited by extensive experimental screening. Here we report a computational model to understand and predict orientational changes of surface-anchored nematic liquid crystals in response to chemical stimuli. In particular, we use first-principles calculations to evaluate the binding energies of benzonitrile, a model for 4'-pentyl-4-biphenylcarbonitrile, and dimethyl methylphosphonate to metal cation models representing the substrate chemical sensing surface. We find a correlation between these quantities and the experimental response time useful for predicting the response time of cation-liquid crystal combinations. Consideration of charge donation from chemical species in the surface environment is critical for obtaining agreement between theory and experiment. Our model may be extended to the design of improved chemoresponsive liquid crystals for selectively detecting other chemicals of practical interest by choosing appropriate combinations of metal cations with liquid crystals of suitable molecular structure.

  8. Equilibrium and dynamic design principles for binding molecules engineered for reagentless biosensors.

    PubMed

    de Picciotto, Seymour; Imperiali, Barbara; Griffith, Linda G; Wittrup, K Dane

    2014-09-01

    Reagentless biosensors rely on the interaction of a binding partner and its target to generate a change in fluorescent signal using an environment-sensitive fluorophore or Förster resonance energy transfer. Binding affinity can exert a significant influence on both the equilibrium and the dynamic response characteristics of such a biosensor. We here develop a kinetic model for the dynamic performance of a reagentless biosensor. Using a sinusoidal signal for ligand concentration, our findings suggest that it is optimal to use a binding moiety whose equilibrium dissociation constant matches that of the average predicted input signal, while maximizing both the association rate constant and the dissociation rate constant at the necessary ratio to create the desired equilibrium constant. Although practical limitations constrain the attainment of these objectives, the derivation of these design principles provides guidance for improved reagentless biosensor performance and metrics for quality standards in the development of biosensors. These concepts are broadly relevant to reagentless biosensor modalities.

  9. Towards first-principles molecular design of liquid crystal-based chemoresponsive systems

    PubMed Central

    Roling, Luke T.; Scaranto, Jessica; Herron, Jeffrey A.; Yu, Huaizhe; Choi, Sangwook; Abbott, Nicholas L.; Mavrikakis, Manos

    2016-01-01

    Nematic liquid crystals make promising chemoresponsive systems, but their development is currently limited by extensive experimental screening. Here we report a computational model to understand and predict orientational changes of surface-anchored nematic liquid crystals in response to chemical stimuli. In particular, we use first-principles calculations to evaluate the binding energies of benzonitrile, a model for 4′-pentyl-4-biphenylcarbonitrile, and dimethyl methylphosphonate to metal cation models representing the substrate chemical sensing surface. We find a correlation between these quantities and the experimental response time useful for predicting the response time of cation–liquid crystal combinations. Consideration of charge donation from chemical species in the surface environment is critical for obtaining agreement between theory and experiment. Our model may be extended to the design of improved chemoresponsive liquid crystals for selectively detecting other chemicals of practical interest by choosing appropriate combinations of metal cations with liquid crystals of suitable molecular structure. PMID:27804955

  10. Design Principles of Electronic Couplings for Intramolecular Singlet Fission in Covalently-Linked Systems.

    PubMed

    Ito, Soichi; Nagami, Takanori; Nakano, Masayoshi

    2016-08-11

    We theoretically investigate the singlet fission in three types of covalently-linked systems, that is, ortho-, meta- and para-linked pentacene dimers, where these are shown to have significantly different singlet fission rates. Each molecule is composed of two chromophores (pentacenes), which are active sites for singlet fission, and covalent bridges linking them. We clarify the origin of the difference in the electronic couplings in these systems, which are found to well support a recent experimental observation. It is also found that the next-nearest-neighbor interaction is indispensable for intramolecular singlet fission in these systems. On the basis of these results, we present design principles for efficient intramolecular singlet fission in covalently-linked systems and demonstrate the performance by using several novel conjugated linkers.

  11. Design of a speed meter interferometer proof-of-principle experiment

    NASA Astrophysics Data System (ADS)

    Gräf, C.; Barr, B. W.; Bell, A. S.; Campbell, F.; Cumming, A. V.; Danilishin, S. L.; Gordon, N. A.; Hammond, G. D.; Hennig, J.; Houston, E. A.; Huttner, S. H.; Jones, R. A.; Leavey, S. S.; Lück, H.; Macarthur, J.; Marwick, M.; Rigby, S.; Schilling, R.; Sorazu, B.; Spencer, A.; Steinlechner, S.; Strain, K. A.; Hild, S.

    2014-11-01

    The second generation of large scale interferometric gravitational wave (GW) detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter (SSM) interferometer, which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify SSM for further research towards an implementation in a future generation large scale GW detector, such as the planned Einstein telescope observatory.

  12. Ab initio identified design principles of solid-solution strengthening in Al.

    PubMed

    Ma, Duancheng; Friák, Martin; von Pezold, Johann; Raabe, Dierk; Neugebauer, Jörg

    2013-04-01

    Solid-solution strengthening in six Al-X binary systems is investigated using first-principle methods. The volumetric mismatch parameter and the solubility enthalpy per solute were calculated. We derive three rules for designing solid-solution strengthened alloys: (i) the solubility enthalpy per solute is related to the volumetric mismatch by a power law; (ii) for each annealing temperature, there exists an optimal solute-volume mismatch to achieve maximum strength; and (iii) the strengthening potential of high volumetric mismatch solutes is severely limited by their low solubility. Our results thus show that the thermodynamic properties of the system (here Al-X alloys) set clear upper bounds to the achievable strengthening effects owing to the reduced solubility with increasing volume mismatch.

  13. Principles and Design of a Zeeman–Sisyphus Decelerator for Molecular Beams

    PubMed Central

    Tarbutt, M. R.

    2016-01-01

    Abstract We explore a technique for decelerating molecules using a static magnetic field and optical pumping. Molecules travel through a spatially varying magnetic field and are repeatedly pumped into a weak‐field seeking state as they move towards each strong field region, and into a strong‐field seeking state as they move towards weak field. The method is time‐independent and so is suitable for decelerating both pulsed and continuous molecular beams. By using guiding magnets at each weak field region, the beam can be simultaneously guided and decelerated. By tapering the magnetic field strength in the strong field regions, and exploiting the Doppler shift, the velocity distribution can be compressed during deceleration. We develop the principles of this deceleration technique, provide a realistic design, use numerical simulations to evaluate its performance for a beam of CaF, and compare this performance to other deceleration methods. PMID:27629547

  14. EQUILIBRIUM AND DYNAMIC DESIGN PRINCIPLES FOR BINDING MOLECULES ENGINEERED FOR REAGENTLESS BIOSENSORS

    PubMed Central

    de Picciotto, Seymour; Imperiali, Barbara; Griffith, Linda G.; Wittrup, K. Dane

    2014-01-01

    Reagentless biosensors rely on the interaction of a binding partner and its target to generate a change in fluorescent signal using an environment sensitive fluorophore or Förster Resonance Energy Transfer. Binding affinity can exert a significant influence on both the equilibrium and the dynamic response characteristics of such a biosensor. We here develop a kinetic model for the dynamic performance of a reagentless biosensor. Using a sinusoidal signal for ligand concentration, our findings suggest that it is optimal to use a binding moiety whose equilibrium dissociation constant matches that of the average predicted input signal, while maximizing both the association rate constant and the dissociation rate constant at the necessary ratio to create the desired equilibrium constant. Although practical limitations constrain the attainment of these objectives, the derivation of these design principles provides guidance for improved reagentless biosensor performance and metrics for quality standards in the development of biosensors. These concepts are broadly relevant to reagentless biosensor modalities. PMID:24814226

  15. Three design principles of language: the search for parsimony in redundancy.

    PubMed

    Beekhuizen, Barend; Bod, Rens; Zuidema, Willem

    2013-09-01

    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 usage-based linguistic approaches alike, the question how much of it is cognitively realistic and/or computationally optimally efficient is an open one. We argue that a segmentation-based approach (Bayesian Model Merging) combined with an all-subtrees approach reduces the number of rules needed to achieve an optimal performance, thus making the parser more efficient. At the same time, starting from unsegmented wholes comes closer to the acquisitional situation of a language learner, and thus adds to the cognitive plausibility of the model.

  16. Multi-objective optimal design of lithium-ion battery packs based on evolutionary algorithms

    NASA Astrophysics Data System (ADS)

    Severino, Bernardo; Gana, Felipe; Palma-Behnke, Rodrigo; Estévez, Pablo A.; Calderón-Muñoz, Williams R.; Orchard, Marcos E.; Reyes, Jorge; Cortés, Marcelo

    2014-12-01

    Lithium-battery energy storage systems (LiBESS) are increasingly being used on electric mobility and stationary applications. Despite its increasing use and improvements of the technology there are still challenges associated with cost reduction, increasing lifetime and capacity, and higher safety. A correct battery thermal management system (BTMS) design is critical to achieve these goals. In this paper, a general framework for obtaining optimal BTMS designs is proposed. Due to the trade-off between the BTMS's design goals and the complex modeling of thermal response inside the battery pack, this paper proposes to solve this problem using a novel Multi-Objective Particle Swarm Optimization (MOPSO) approach. A theoretical case of a module with 6 cells and a real case of a pack used in a Solar Race Car are presented. The results show the capabilities of the proposal methodology, in which improved designs for battery packs are obtained.

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

    NASA Technical Reports Server (NTRS)

    Englander, Jacob

    2016-01-01

    Preliminary design of interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated. This can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on notional high-thrust chemical and low-thrust electric propulsion missions. In the low-thrust case, the hybrid optimal control problem is augmented to include systems design optimization.

  18. Synergy as design principle for metabolic engineering of 1-propanol production in Escherichia coli.

    PubMed

    Shen, Claire R; Liao, James C

    2013-05-01

    Synthesis of a desired product can often be achieved via more than one metabolic pathway. Whether naturally evolved or synthetically engineered, these pathways often exhibit specific properties that are suitable for production under distinct conditions and host organisms. Synergy between pathways arises when the underlying pathway characteristics, such as reducing equivalent demand, ATP requirement, intermediate utilization, and cofactor preferences, are complementary to each other. Utilization of such pathways in combination leads to an increased metabolite productivity and/or yield compared to using each pathway alone. This work illustrates the principle of synergy between two different pathways for 1-propanol production in Escherichia coli. A model-guided design based on maximum theoretical yield calculations identified synergy of the native threonine pathway and the heterologous citramalate pathway in terms of production yield across all flux ratios between the two pathways. Characterization of the individual pathways by host gene deletions demonstrates their distinct metabolic characteristics: the necessity of TCA cycle for threonine pathway and the independence of TCA cycle for the citramalate pathway. The two pathways are also complementary in driving force demands. Production experiments verified the synergistic effects predicted by the yield model, in which the platform with dual pathway for 2-ketobutyrate synthesis achieved higher yield (0.15g/g of glucose) and productivity (0.12g/L/h) of 1-propanol than individual ones alone: the threonine pathway (0.09g/g; 0.04g/L/h) or the citramalate pathway (0.11g/g; 0.04g/L/h). Thus, incorporation of synergy into the design principle of metabolic engineering may improve the production yield and rate of the desired compound.

  19. Developing an approach for first-principles catalyst design: application to carbon-capture catalysis.

    PubMed

    Kulik, Heather J; Wong, Sergio E; Baker, Sarah E; Valdez, Carlos A; Satcher, Joe H; Aines, Roger D; Lightstone, Felice C

    2014-02-01

    An approach to catalyst design is presented in which local potential energy surface models are first built to elucidate design principles and then used to identify larger scaffold motifs that match the target geometries. Carbon sequestration via hydration is used as the model reaction, and three- and four-coordinate sp(2) or sp(3) nitrogen-ligand motifs are considered for Zn(II) metals. The comparison of binding, activation and product release energies over a large range of interaction distances and angles suggests that four-coordinate short Zn(II)-Nsp(3) bond distances favor a rapid turnover for CO2 hydration. This design strategy is then confirmed by computationally characterizing the reactivity of a known mimic over a range of metal-nitrogen bond lengths. A search of existing catalysts in a chemical database reveals structures that match the target geometry from model calculations, and subsequent calculations have identified these structures as potentially effective for CO2 hydration and sequestration.

  20. Extending the generality of leaf economic design principles in the cycads, an ancient lineage.

    PubMed

    Zhang, Yong-Jiang; Cao, Kun-Fang; Sack, Lawren; Li, Nan; Wei, Xue-Mei; Goldstein, Guillermo

    2015-04-01

    Cycads are the most ancient lineage of living seed plants, but the design of their leaves has received little study. We tested whether cycad leaves are governed by the same fundamental design principles previously established for ferns, conifers and angiosperms, and characterized the uniqueness of this relict lineage in foliar trait relationships. Leaf structure, photosynthesis, hydraulics and nutrient composition were studied in 33 cycad species from nine genera and three families growing in two botanical gardens. Cycads varied greatly in leaf structure and physiology. Similarly to other lineages, light-saturated photosynthetic rate per mass (Am ) was related negatively to leaf mass per area and positively to foliar concentrations of chlorophyll, nitrogen (N), phosphorus and iron, but unlike angiosperms, leaf photosynthetic rate was not associated with leaf hydraulic conductance. Cycads had lower photosynthetic N use efficiency and higher photosynthetic performance relative to hydraulic capacity compared with other lineages. These findings extend the relationships shown for foliar traits in angiosperms to the cycads. This functional convergence supports the modern synthetic understanding of leaf design, with common constraints operating across lineages, even as they highlight exceptional aspects of the biology of this key relict lineage.

  1. Design principles of natural light-harvesting as revealed by single molecule spectroscopy

    NASA Astrophysics Data System (ADS)

    Krüger, T. P. J.; van Grondelle, R.

    2016-01-01

    Biology offers a boundless source of adaptation, innovation, and inspiration. A wide range of photosynthetic organisms exist that are capable of harvesting solar light in an exceptionally efficient way, using abundant and low-cost materials. These natural light-harvesting complexes consist of proteins that strongly bind a high density of chromophores to capture solar photons and rapidly transfer the excitation energy to the photochemical reaction centre. The amount of harvested light is also delicately tuned to the level of solar radiation to maintain a constant energy throughput at the reaction centre and avoid the accumulation of the products of charge separation. In this Review, recent developments in the understanding of light-harvesting by plants will be discussed, based on results obtained from single molecule spectroscopy studies. Three design principles of the main light-harvesting antenna of plants will be highlighted: (a) fine, photoactive control over the intrinsic protein disorder to efficiently use intrinsically available thermal energy dissipation mechanisms; (b) the design of the protein microenvironment of a low-energy chromophore dimer to control the amount of shade absorption; (c) the design of the exciton manifold to ensure efficient funneling of the harvested light to the terminal emitter cluster.

  2. Determination of critical quality attributes for monoclonal antibodies using quality by design principles.

    PubMed

    Alt, Nadja; Zhang, Taylor Y; Motchnik, Paul; Taticek, Ron; Quarmby, Valerie; Schlothauer, Tilman; Beck, Hermann; Emrich, Thomas; Harris, Reed J

    2016-09-01

    Quality by design (QbD) is a global regulatory initiative with the goal of enhancing pharmaceutical development through the proactive design of pharmaceutical manufacturing process and controls to consistently deliver the intended performance of the product. The principles of pharmaceutical development relevant to QbD are described in the ICH guidance documents (ICHQ8-11). An integrated set of risk assessments and their related elements developed at Roche/Genentech were designed to provide an overview of product and process knowledge for the production of a recombinant monoclonal antibody. This chapter describes the identification of critical quality attributes (CQAs) as an important first step for QbD development of biopharmaceuticals. A systematic scientific based risk ranking and filtering approach allows a thorough understanding of quality attributes and an assignment of criticality for their impact on drug safety and efficacy. To illustrate the application of the approach and tools, a few examples from monoclonal antibodies are shown. The identification of CQAs is a continuous process and will further drive the structure and function characterization of therapeutic proteins.

  3. Design concepts and principle of operation of the HeartWare ventricular assist system.

    PubMed

    Larose, Jeffrey A; Tamez, Daniel; Ashenuga, Michael; Reyes, Carlos

    2010-01-01

    Implantable left ventricular assist devices provide circulatory support for patients at risk of death from refractory, end-stage heart failure. Rotary blood pumps have been designed for increased reliability and smaller size for use in a broader population of patients than the first-generation pulsatile devices. The design concepts and principle of operation of the HeartWare System are discussed. The HeartWare Ventricular Assist System (HVAD) is a small centrifugal flow pump with a displacement volume of 50 ml and an output capacity of 10 L/min. A unique wide-blade impeller is suspended by hybrid passive magnets and hydrodynamic forces. An integrated inflow cannula is inserted into the left ventricle and is held in position by an adjustable sewing ring; the pump is positioned in the pericardial space. The 10-mm outflow graft is anastomosed to the ascending aorta. External system components include the microprocessor-based controller, a monitor, lithium-ion battery packs, alternating current and direct current power adapters, and a battery charger. Physiologic control algorithms are incorporated for safe operation. Preclinical life cycle tests have shown the HVAD to be highly reliable. This system design offers reliability, portability, and ease of use for ambulatory patients.

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

    PubMed

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

    2007-03-01

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

  5. Development and characterization of a cell culture manufacturing process using quality by design (QbD) principles.

    PubMed

    Marasco, Daniel M; Gao, Jinxin; Griffiths, Kristi; Froggatt, Christopher; Wang, Tongtong; Wei, Gan

    2014-01-01

    The principles of quality by design (QbD) have been applied in cell culture manufacturing process development and characterization in the biotech industry. Here we share our approach and practice in developing and characterizing a cell culture manufacturing process using QbD principles for establishing a process control strategy. Process development and characterization start with critical quality attribute identification, followed by process parameter and incoming raw material risk assessment, design of experiment, and process parameter classification, and conclude with a design space construction. Finally, a rational process control strategy is established and documented.

  6. A backbone design principle for covalent organic frameworks: the impact of weakly interacting units on CO2 adsorption.

    PubMed

    Zhai, Lipeng; Huang, Ning; Xu, Hong; Chen, Qiuhong; Jiang, Donglin

    2017-03-31

    Covalent organic frameworks are designed to have backbones with different yet discrete contents of triarylamine units that interact weakly with CO2. Adsorption experiments indicate that the triarylamine units dominate the CO2 adsorption process and the CO2 uptake increases monotonically with the triarylamine content. These profound collective effects reveal a principle for designing backbones targeting for CO2 capture and separation.

  7. An Analysis of Factors that Inhibit Business Use of User-Centered Design Principles: A Delphi Study

    ERIC Educational Resources Information Center

    Hilton, Tod M.

    2010-01-01

    The use of user-centered design (UCD) principles has a positive impact on the use of web-based interactive systems in customer-centric organizations. User-centered design methodologies are not widely adopted in organizations due to intraorganizational factors. A qualitative study using a modified Delphi technique was used to identify the factors…

  8. Active vibration absorber for CSI evolutionary model: Design and experimental results

    NASA Technical Reports Server (NTRS)

    Bruner, Anne M.; Belvin, W. Keith; Horta, Lucas G.; Juang, Jer-Nan

    1991-01-01

    The development of control of large flexible structures technology must include practical demonstration to aid in the understanding and characterization of controlled structures in space. To support this effort, a testbed facility was developed to study practical implementation of new control technologies under realistic conditions. The design is discussed of a second order, acceleration feedback controller which acts as an active vibration absorber. This controller provides guaranteed stability margins for collocated sensor/actuator pairs in the absence of sensor/actuator dynamics and computational time delay. The primary performance objective considered is damping augmentation of the first nine structural modes. Comparison of experimental and predicted closed loop damping is presented, including test and simulation time histories for open and closed loop cases. Although the simulation and test results are not in full agreement, robustness of this design under model uncertainty is demonstrated. The basic advantage of this second order controller design is that the stability of the controller is model independent.

  9. Evolutionary exploitation of design options by the first animals with hard skeletons.

    PubMed

    Thomas, R D; Shearman, R M; Stewart, G W

    2000-05-19

    The set of viable design elements available for animals to use in building skeletons has been fully exploited. Analysis of animal skeletons in relation to the multivariate, theoretical "Skeleton Space" has shown that a large proportion of these options are used in each phylum. Here, we show that structural elements deployed in the skeletons of Burgess Shale animals (Middle Cambrian) incorporate 146 of 182 character pairs defined in this morphospace. Within 15 million years of the appearance of crown groups of phyla with substantial hard parts, at least 80 percent of skeletal design elements recognized among living and extinct marine metazoans were exploited.

  10. A novel evolutionary approach to image enhancement filter design: method and applications.

    PubMed

    Hong, Jin-Hyuk; Cho, Sung-Bae; Cho, Ung-Keun

    2009-12-01

    Image enhancement is an important issue in digital image processing. Various approaches have been developed to solve image enhancement problems, but most of them require deep expert knowledge to design appropriate image filters. To automatically design a filter, we propose a novel approach based on the genetic algorithm that optimizes a set of standard filters by determining their types and order. Moreover, the proposed method is able to manage various types of noise factors. We applied the proposed method to local and global image enhancement problems such as impulsive noise reduction, interpolation, and orientation enhancement. In terms of subjective and objective evaluations, the results show the superiority of the proposed method.

  11. Active vibration absorber for the CSI evolutionary model - Design and experimental results. [Controls Structures Interaction

    NASA Technical Reports Server (NTRS)

    Bruner, Anne M.; Belvin, W. Keith; Horta, Lucas G.; Juang, Jer-Nan

    1991-01-01

    The development of control of large flexible structures technology must include practical demonstrations to aid in the understanding and characterization of controlled structures in space. To support this effort, a testbed facility has been developed to study practical implementation of new control technologies under realistic conditions. The paper discusses the design of a second order, acceleration feedback controller which acts as an active vibration absorber. This controller provides guaranteed stability margins for collocated sensor/actuator pairs in the absence of sensor/actuator dynamics and computational time delay. Experimental results in the presence of these factors are presented and discussed. The robustness of this design under model uncertainty is demonstrated.

  12. Evolutionary and Cognitive Motivations for Fractal Art in Art and Design Education

    ERIC Educational Resources Information Center

    Joye, Yannick

    2005-01-01

    Humans are endowed with cognitive modules specialised in processing information about the class of natural things. Due to their naturalness, fractal art and design can contribute to developing these modules, and trigger affective responses that are associated with certain natural objects. It is argued that exposure to fractals in an art and design…

  13. Evolutionary Development: A Model for the Design, Implementation, and Evaluation of ICT for Education Programmes

    ERIC Educational Resources Information Center

    Rodriguez, P.; Nussbaum, M.; Dombrovskaia, L.

    2012-01-01

    The impact of information and communication technology (ICT) in primary and secondary education is still an open question. Following review of the available literature, we classify the causes of the lack of impact on students' attainment in four dimensions: (1) the design and implementation of ICT in educational settings; (2) the evaluation of its…

  14. First-principles modeling of biological systems and structure-based drug-design.

    PubMed

    Sgrignani, Jacopo; Magistrato, Alessandra

    2013-03-01

    Molecular modeling techniques play a relevant role in drug design providing detailed information at atomistic level on the structural, dynamical, mechanistic and electronic properties of biological systems involved in diseases' onset, integrating and supporting commonly used experimental approaches. These information are often not accessible to the experimental techniques taken singularly, but are of crucial importance for drug design. Due to the enormous increase of the computer power in the last decades, quantum mechanical (QM) or first-principles-based methods have become often used to address biological issues of pharmaceutical relevance, providing relevant information for drug design. Due to their complexity and their size, biological systems are often investigated by means of a mixed quantum-classical (QM/MM) approach, which treats at an accurate QM level a limited chemically relevant portion of the system and at the molecular mechanics (MM) level the remaining of the biomolecule and its environment. This method provides a good compromise between computational cost and accuracy, allowing to characterize the properties of the biological system and the (free) energy landscape of the process in study with the accuracy of a QM description. In this review, after a brief introduction of QM and QM/MM methods, we will discuss few representative examples, taken from our work, of the application of these methods in the study of metallo-enzymes of pharmaceutical interest, of metal-containing anticancer drugs targeting the DNA as well as of neurodegenerative diseases. The information obtained from these studies may provide the basis for a rationale structure-based drug design of new and more efficient inhibitors or drugs.

  15. Evolutionary Science as a Method to Facilitate Higher Level Thinking and Reasoning in Medical Training.

    PubMed

    Graves, Joseph L; Reiber, Chris; Thanukos, Anna; Hurtado, Magdalena; Wolpaw, Terry

    2016-10-15

    Evolutionary science is indispensable for understanding biological processes. Effective medical treatment must be anchored in sound biology. However, currently the insights available from evolutionary science are not adequately incorporated in either pre-medical or medical school curricula. To illuminate how evolution may be helpful in these areas, examples in which the insights of evolutionary science are already improving medical treatment and ways in which evolutionary reasoning can be practiced in the context of medicine are provided. In order to facilitate the learning of evolutionary principles, concepts derived from evolutionary science that medical students and professionals should understand are outlined. These concepts are designed to be authoritative and at the same time easily accessible for anyone with the general biological knowledge of a first-year medical student. Thus we conclude that medical practice informed by evolutionary principles will be more effective and lead to better patient outcomes.Furthermore, it is argued that evolutionary medicine complements general medical training because it provides an additional means by which medical students can practice the critical thinking skills that will be important in their future practice. We argue that core concepts from evolutionary science have the potential to improve critical thinking and facilitate more effective learning in medical training.

  16. Evolutionary science as a method to facilitate higher level thinking and reasoning in medical training

    PubMed Central

    Graves, Joseph L.; Reiber, Chris; Thanukos, Anna; Hurtado, Magdalena; Wolpaw, Terry

    2016-01-01

    Evolutionary science is indispensable for understanding biological processes. Effective medical treatment must be anchored in sound biology. However, currently the insights available from evolutionary science are not adequately incorporated in either pre-medical or medical school curricula. To illuminate how evolution may be helpful in these areas, examples in which the insights of evolutionary science are already improving medical treatment and ways in which evolutionary reasoning can be practiced in the context of medicine are provided. To facilitate the learning of evolutionary principles, concepts derived from evolutionary science that medical students and professionals should understand are outlined. These concepts are designed to be authoritative and at the same time easily accessible for anyone with the general biological knowledge of a first-year medical student. Thus, we conclude that medical practice informed by evolutionary principles will be more effective and lead to better patient outcomes. Furthermore, it is argued that evolutionary medicine complements general medical training because it provides an additional means by which medical students can practice the critical thinking skills that will be important in their future practice. We argue that core concepts from evolutionary science have the potential to improve critical thinking and facilitate more effective learning in medical training. PMID:27744353

  17. Design principles and field performance of a solar spectral irradiance meter

    SciTech Connect

    Tatsiankou, V.; Hinzer, K.; Haysom, J.; Schriemer, H.; Emery, K.; Beal, R.

    2016-08-01

    A solar spectral irradiance meter (SSIM), designed for measuring the direct normal irradiance (DNI) in six wavelength bands, has been combined with models to determine key atmospheric transmittances and the resulting spectral irradiance distribution of DNI under all sky conditions. The design principles of the SSIM, implementation of a parameterized transmittance model, and field performance comparisons of modeled solar spectra with reference radiometer measurements are presented. Two SSIMs were tested and calibrated at the National Renewable Energy Laboratory (NREL) against four spectroradiometers and an absolute cavity radiometer. The SSIMs' DNI was on average within 1% of the DNI values reported by one of NREL's primary absolute cavity radiometers. An additional SSIM was installed at the SUNLAB Outdoor Test Facility in September 2014, with ongoing collection of environmental and spectral data. The SSIM's performance in Ottawa was compared against a commercial pyrheliometer and a spectroradiometer over an eight month study. The difference in integrated daily spectral irradiance between the SSIM and the ASD spectroradiometer was found to be less than 1%. The cumulative energy density collected by the SSIM over this duration agreed with that measured by an Eppley model NIP pyrheliometer to within 0.5%. No degradation was observed.

  18. Ultra-high resolution flat-panel volume CT: fundamental principles, design architecture, and system characterization.

    PubMed

    Gupta, Rajiv; Grasruck, Michael; Suess, Christoph; Bartling, Soenke H; Schmidt, Bernhard; Stierstorfer, Karl; Popescu, Stefan; Brady, Tom; Flohr, Thomas

    2006-06-01

    Digital flat-panel-based volume CT (VCT) represents a unique design capable of ultra-high spatial resolution, direct volumetric imaging, and dynamic CT scanning. This innovation, when fully developed, has the promise of opening a unique window on human anatomy and physiology. For example, the volumetric coverage offered by this technology enables us to observe the perfusion of an entire organ, such as the brain, liver, or kidney, tomographically (e.g., after a transplant or ischemic event). By virtue of its higher resolution, one can directly visualize the trabecular structure of bone. This paper describes the basic design architecture of VCT. Three key technical challenges, viz., scatter correction, dynamic range extension, and temporal resolution improvement, must be addressed for successful implementation of a VCT scanner. How these issues are solved in a VCT prototype and the modifications necessary to enable ultra-high resolution volumetric scanning are described. The fundamental principles of scatter correction and dose reduction are illustrated with the help of an actual prototype. The image quality metrics of this prototype are characterized and compared with a multi-detector CT (MDCT).

  19. Inverse Problem Optimization Method to Design Passive Samplers for Volatile Organic Compounds: Principle and Application.

    PubMed

    Cao, Jianping; Du, Zhengjian; Mo, Jinhan; Li, Xinxiao; Xu, Qiujian; Zhang, Yinping

    2016-12-20

    Passive sampling is an alternative to active sampling for measuring concentrations of gas-phase volatile organic compounds (VOCs). However, the uncertainty or relative error of the measurements have not been minimized due to the limitations of existing design methods. In this paper, we have developed a novel method, the inverse problem optimization method, to address the problems associated with designing accurate passive samplers. The principle is to determine the most appropriate physical properties of the materials, and the optimal geometry of a passive sampler, by minimizing the relative sampling error based on the mass transfer model of VOCs for a passive sampler. As an example application, we used our proposed method to optimize radial passive samplers for the sampling of benzene and formaldehyde in a normal indoor environment. A new passive sampler, which we have called the Tsinghua Passive Diffusive Sampler (THPDS), for indoor benzene measurement was developed according to the optimized results. Silica zeolite was selected as the sorbent for the THPDS. The measured overall uncertainty of THPDS (22% for benzene) is lower than that of most commercially available passive samplers but is quite a bit larger than the modeled uncertainty (4.8% for benzene, the optimized result), suggesting that further research is required.

  20. Structural design principles for delivery of bioactive components in nutraceuticals and functional foods.

    PubMed

    McClements, David Julian; Decker, Eric Andrew; Park, Yeonhwa; Weiss, Jochen

    2009-06-01

    There have been major advances in the design and fabrication of structured delivery systems for the encapsulation of nutraceutical and functional food components. A wide variety of delivery systems is now available, each with its own advantages and disadvantages for particular applications. This review begins by discussing some of the major nutraceutical and functional food components that need to be delivered and highlights the main limitations to their current utilization within the food industry. It then discusses the principles underpinning the rational design of structured delivery systems: the structural characteristics of the building blocks; the nature of the forces holding these building blocks together; and, the different ways of assembling these building blocks into structured delivery systems. Finally, we review the major types of structured delivery systems that are currently available to food scientists: lipid-based (simple, multiple, multilayer, and solid lipid particle emulsions); surfactant-based (simple micelles, mixed micelles, vesicles, and microemulsions) and biopolymer-based (soluble complexes, coacervates, hydrogel droplets, and particles). For each type of delivery system we describe its preparation, properties, advantages, and limitations.

  1. A master-slave parallel hybrid multi-objective evolutionary algorithm for groundwater remediation design under general hydrogeological conditions

    NASA Astrophysics Data System (ADS)

    Wu, J.; Yang, Y.; Luo, Q.; Wu, J.

    2012-12-01

    This study presents a new hybrid multi-objective evolutionary algorithm, the niched Pareto tabu search combined with a genetic algorithm (NPTSGA), whereby the global search ability of niched Pareto tabu search (NPTS) is improved by the diversification of candidate solutions arose from the evolving nondominated sorting genetic algorithm II (NSGA-II) population. Also, the NPTSGA coupled with the commonly used groundwater flow and transport codes, MODFLOW and MT3DMS, is developed for multi-objective optimal design of groundwater remediation systems. The proposed methodology is then applied to a large-scale field groundwater remediation system for cleanup of large trichloroethylene (TCE) plume at the Massachusetts Military Reservation (MMR) in Cape Cod, Massachusetts. Furthermore, a master-slave (MS) parallelization scheme based on the Message Passing Interface (MPI) is incorporated into the NPTSGA to implement objective function evaluations in distributed processor environment, which can greatly improve the efficiency of the NPTSGA in finding Pareto-optimal solutions to the real-world application. This study shows that the MS parallel NPTSGA in comparison with the original NPTS and NSGA-II can balance the tradeoff between diversity and optimality of solutions during the search process and is an efficient and effective tool for optimizing the multi-objective design of groundwater remediation systems under complicated hydrogeologic conditions.

  2. The design of free structure granular mappings: the use of the principle of justifiable granularity.

    PubMed

    Pedrycz, Witold; Al-Hmouz, Rami; Morfeq, Ali; Balamash, Abdullah

    2013-12-01

    The study introduces a concept of mappings realized in presence of information granules and offers a design framework supporting the formation of such mappings. Information granules are conceptually meaningful entities formed on a basis of a large number of experimental input–output numeric data available for the construction of the model. We develop a conceptually and algorithmically sound way of forming information granules. Considering the directional nature of the mapping to be formed, this directionality aspect needs to be taken into account when developing information granules. The property of directionality implies that while the information granules in the input space could be constructed with a great deal of flexibility, the information granules formed in the output space have to inherently relate to those built in the input space. The input space is granulated by running a clustering algorithm; for illustrative purposes, the focus here is on fuzzy clustering realized with the aid of the fuzzy C-means algorithm. The information granules in the output space are constructed with the aid of the principle of justifiable granularity (being one of the underlying fundamental conceptual pursuits of Granular Computing). The construct exhibits two important features. First, the constructed information granules are formed in the presence of information granules already constructed in the input space (and this realization is reflective of the direction of the mapping from the input to the output space). Second, the principle of justifiable granularity does not confine the realization of information granules to a single formalism such as fuzzy sets but helps form the granules expressed any required formalism of information granulation. The quality of the granular mapping (viz. the mapping realized for the information granules formed in the input and output spaces) is expressed in terms of the coverage criterion (articulating how well the experimental data are

  3. Water, Resilience and the Law: From General Concepts and Governance Design Principles to Actionable Mechanisms

    NASA Astrophysics Data System (ADS)

    Hill Clarvis, M.; Allan, A.; Hannah, D. M.

    2013-12-01

    least data infrastructure. The article aims to contribute to both theory and practice, enabling policy makers to translate resilience based terminology and adaptive governance principles into clear instructions for incorporating uncertainty into legislation and policy design.

  4. A mechanical design principle for tissue structure and function in the airway tree.

    PubMed

    LaPrad, Adam S; Lutchen, Kenneth R; Suki, Béla

    2013-01-01

    With every breath, the dynamically changing mechanical pressures must work in unison with the cells and soft tissue structures of the lung to permit air to efficiently traverse the airway tree and undergo gas exchange in the alveoli. The influence of mechanics on cell and tissue function is becoming apparent, raising the question: how does the airway tree co-exist within its mechanical environment to maintain normal cell function throughout its branching structure of diminishing dimensions? We introduce a new mechanical design principle for the conducting airway tree in which mechanotransduction at the level of cells is driven to orchestrate airway wall structural changes that can best maintain a preferred mechanical microenvironment. To support this principle, we report in vitro radius-transmural pressure relations for a range of airway radii obtained from healthy bovine lungs and model the data using a strain energy function together with a thick-walled cylinder description. From this framework, we estimate circumferential stresses and incremental Young's moduli throughout the airway tree. Our results indicate that the conducting airways consistently operate within a preferred mechanical homeostatic state, termed mechanical homeostasis, that is characterized by a narrow range of circumferential stresses and Young's moduli. This mechanical homeostatic state is maintained for all airways throughout the tree via airway wall dimensional and mechanical relationships. As a consequence, cells within the airway walls throughout the airway tree experience similar oscillatory strains during breathing that are much smaller than previously thought. Finally, we discuss the potential implications of how the maintenance of mechanical homeostasis, while facilitating healthy tissue-level alterations necessary for maturation, may lead to airway wall structural changes capable of chronic asthma.

  5. Evolutionary Design of an X-Band Antenna for NASA's Space Technology 5 Mission

    NASA Technical Reports Server (NTRS)

    Lohn, Jason D.; Hornby, Gregory S.; Rodriguez-Arroyo, Adan; Linden, Derek S.; Kraus, William F.; Seufert, Stephen E.

    2003-01-01

    We present an evolved X-band antenna design and flight prototype currently on schedule to be deployed on NASA s Space Technology 5 spacecraft in 2004. The mission consists of three small satellites that wall take science measurements in Earth s magnetosphere. The antenna was evolved to meet a challenging set of mission requirements, most notably the combination of wide beamwidth for a circularly-polarized wave and wide bandwidth. Two genetic algorithms were used: one allowed branching an the antenna arms and the other did not. The highest performance antennas from both algorithms were fabricated and tested. A handdesigned antenna was produced by the contractor responsible for the design and build of the mission antennas. The hand-designed antenna is a quadrifilar helix, and we present performance data for comparison to the evolved antennas. As of this writing, one of our evolved antenna prototypes is undergoing flight qualification testing. If successful, the resulting antenna would represent the first evolved hardware in space, and the first deployed evolved antenna.

  6. Development of next generation digital flat panel catheterization system: design principles and validation methodology

    NASA Astrophysics Data System (ADS)

    Belanger, B.; Betraoui, F.; Dhawale, P.; Gopinath, P.; Tegzes, Pal; Vagvolgyi, B.

    2006-03-01

    The design principles that drove the development of a new cardiovascular x-ray digital flat panel (DFP) detector system are presented, followed by assessments of imaging and dose performance achieved relative to other state of the art FPD systems. The new system (GE Innova 2100 IQ TM) incorporates a new detector with substantially improved DQE at fluoroscopic (73%@1μR) and record (79%@114uR) doses, an x-ray tube with higher continuous fluoro power (3.2kW), a collimator with a wide range of copper spectral filtration (up to 0.9mm), and an improved automatic x-ray exposure management system. The performance of this new system was compared to that of the previous generation GE product (Innova 2000) and to state-of-the art cardiac digital x-ray flat panel systems from two other major manufacturers. Performance was assessed with the industry standard Cardiac X-ray NEMA/SCA and I phantom, and a new moving coronary artery stent (MCAS) phantom, designed to simulate cardiac clinical imaging conditions, composed of an anthropomorphic chest section with stents moving in a manner simulating normal coronary arteries. The NEMA/SCA&I phantom results showed the Innova 2100 IQ to exceed or equal the Innova 2000 in all of the performance categories, while operating at 28% lower dose on average, and to exceed the other DFP systems in most of the performance categories. The MCAS phantom tests showed the Innova 2100 IQ to be significantly better (p << 0.05) than the Innova 2000, and significantly better than the other DFP systems in most cases at comparable or lower doses, thereby verifying excellent performance against design goals.

  7. An intelligent control and virtual display system for evolutionary space station workstation design

    NASA Technical Reports Server (NTRS)

    Feng, Xin; Niederjohn, Russell J.; Mcgreevy, Michael W.

    1992-01-01

    Research and development of the Advanced Display and Computer Augmented Control System (ADCACS) for the space station Body-Ported Cupola Virtual Workstation (BP/VCWS) were pursued. The potential applications were explored of body ported virtual display and intelligent control technology for the human-system interfacing applications is space station environment. The new system is designed to enable crew members to control and monitor a variety of space operations with greater flexibility and efficiency than existing fixed consoles. The technologies being studied include helmet mounted virtual displays, voice and special command input devices, and microprocessor based intelligent controllers. Several research topics, such as human factors, decision support expert systems, and wide field of view, color displays are being addressed. The study showed the significant advantages of this uniquely integrated display and control system, and its feasibility for human-system interfacing applications in the space station command and control environment.

  8. Buridan's Principle

    NASA Astrophysics Data System (ADS)

    Lamport, Leslie

    2012-08-01

    Buridan's principle asserts that a discrete decision based upon input having a continuous range of values cannot be made within a bounded length of time. It appears to be a fundamental law of nature. Engineers aware of it can design devices so they have an infinitessimal probability of not making a decision quickly enough. Ignorance of the principle could have serious consequences.

  9. Cell surface receptors for signal transduction and ligand transport - a design principles study

    SciTech Connect

    Shankaran, Harish; Resat, Haluk; Wiley, H. S.

    2007-06-01

    Although many different receptors undergo endocytosis, the system-level design principles that govern the evolution of receptor dynamics are far from fully understood. We have constructed a generalized mathematical model to understand how receptor internalization dynamics encodes receptor function and regulation. Parametric analysis of the response of receptor systems to ligand inputs reveals that receptors can be categorized a being: i) avidity-controlled where the response control depends primarily on the extracelluar ligand capture efficiency, ii) consumption-controlled where the ability to internalize surface-bound ligand is the primary control parameter, and iii) dual-sensitivity where both the avidity and consumption parameters are important. We show that the transferrin and low-density lipoprotein receptors are avidity-controlled, the vitellogenin receptor is consumption-controlled and epidermal growth factor receptor is a dual-sensitivity receptor. Significantly, we show that ligand-induced endocytosis is a mechanism to anhance the accuracy of signaling receptors rather than serving to attenuate signaling. Our analysis reveals that the location of a receptor system in the avidity-consumption parameter space can be used to understand both its function and its regulations.

  10. Stomatal design principles for gas exchange in synthetic and real leaves

    NASA Astrophysics Data System (ADS)

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

    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 geometric properties of the stomata pores. The link between stomata geometry and environmental factors have informed a wide range of scientific fields - from agriculture to climate science, where observed variations in stomata size and density is 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 stomatal geometry. We show that the observed correlations between stomatal size and density are consistent with the hypothesis that plants favor efficient use of space and maximum control of dynamic gas conductivity, and - surprisingly - that the capacity for gas exchange in plants has remained constant over at least the last 325 million years. Our analysis provides a new measure to gauge the relative performance of species based on their stomatal characteristics. Supported by the Carlsberg Foundation (2013-01-0449), VILLUM FONDEN (13166) and the National Science Foundation (EAR-1024041).

  11. Principles underlying the design of "The Number Race", an adaptive computer game for remediation of dyscalculia

    PubMed Central

    Wilson, Anna J; Dehaene, Stanislas; Pinel, Philippe; Revkin, Susannah K; Cohen, Laurent; Cohen, David

    2006-01-01

    Background Adaptive game software has been successful in remediation of dyslexia. Here we describe the cognitive and algorithmic principles underlying the development of similar software for dyscalculia. Our software is based on current understanding of the cerebral representation of number and the hypotheses that dyscalculia is due to a "core deficit" in number sense or in the link between number sense and symbolic number representations. Methods "The Number Race" software trains children on an entertaining numerical comparison task, by presenting problems adapted to the performance level of the individual child. We report full mathematical specifications of the algorithm used, which relies on an internal model of the child's knowledge in a multidimensional "learning space" consisting of three difficulty dimensions: numerical distance, response deadline, and conceptual complexity (from non-symbolic numerosity processing to increasingly complex symbolic operations). Results The performance of the software was evaluated both by mathematical simulations and by five weeks of use by nine children with mathematical learning difficulties. The results indicate that the software adapts well to varying levels of initial knowledge and learning speeds. Feedback from children, parents and teachers was positive. A companion article [1] describes the evolution of number sense and arithmetic scores before and after training. Conclusion The software, open-source and freely available online, is designed for learning disabled children aged 5–8, and may also be useful for general instruction of normal preschool children. The learning algorithm reported is highly general, and may be applied in other domains. PMID:16734905

  12. Guiding principles for printed education materials: design preferences of people with aphasia.

    PubMed

    Rose, Tanya A; Worrall, Linda E; Hickson, Louise M; Hoffmann, Tammy C

    2012-02-01

    The objectives of this study were to obtain the preferences of people with aphasia for the design of stroke and aphasia printed education materials (PEMs) and to compare these preferences with recommendations in the literature for developing written information for other populations. A face-to-face quantitative questionnaire was completed with 40 adults with aphasia post-stroke. The questionnaire explored preferences for: (1) the representation of numbers, (2) font size and type, (3) line spacing, (4) document length, and (5) graphic type. Most preferences (62.4%, n = 146) were for numbers expressed as figures rather than words. The largest proportion of participants selected 14 point (28.2%, n = 11) and Verdana ref (33.3%, n = 13) as the easiest font size and type to read, and a preference for 1.5 line spacing (41.0%, n = 16) was identified. Preference for document length was not related to the participant's reading ability or aphasia severity. Most participants (95.0%, n = 38) considered graphics to be helpful, with photographs more frequently reported as a helpful graphic type. The identified preferences support many of the formatting recommendations found within the literature. This research provides guiding principles for developing PEMs in preferred formats for people with aphasia.

  13. How quantitative measures unravel design principles in multi-stage phosphorylation cascades.

    PubMed

    Frey, Simone; Millat, Thomas; Hohmann, Stefan; Wolkenhauer, Olaf

    2008-09-07

    We investigate design principles of linear multi-stage phosphorylation cascades by using quantitative measures for signaling time, signal duration and signal amplitude. We compare alternative pathway structures by varying the number of phosphorylations and the length of the cascade. We show that a model for a weakly activated pathway does not reflect the biological context well, unless it is restricted to certain parameter combinations. Focusing therefore on a more general model, we compare alternative structures with respect to a multivariate optimization criterion. We test the hypothesis that the structure of a linear multi-stage phosphorylation cascade is the result of an optimization process aiming for a fast response, defined by the minimum of the product of signaling time and signal duration. It is then shown that certain pathway structures minimize this criterion. Several popular models of MAPK cascades form the basis of our study. These models represent different levels of approximation, which we compare and discuss with respect to the quantitative measures.

  14. The great opportunity: Evolutionary applications to medicine and public health

    PubMed Central

    Nesse, Randolph M; Stearns, Stephen C

    2008-01-01

    Abstract Evolutionary biology is an essential basic science for medicine, but few doctors and medical researchers are familiar with its most relevant principles. Most medical schools have geneticists who understand evolution, but few have even one evolutionary biologist to suggest other possible applications. The canyon between evolutionary biology and medicine is wide. The question is whether they offer each other enough to make bridge building worthwhile. What benefits could be expected if evolution were brought fully to bear on the problems of medicine? How would studying medical problems advance evolutionary research? Do doctors need to learn evolution, or is it valuable mainly for researchers? What practical steps will promote the application of evolutionary biology in the areas of medicine where it offers the most? To address these questions, we review current and potential applications of evolutionary biology to medicine and public health. Some evolutionary technologies, such as population genetics, serial transfer production of live vaccines, and phylogenetic analysis, have been widely applied. Other areas, such as infectious disease and aging research, illustrate the dramatic recent progress made possible by evolutionary insights. In still other areas, such as epidemiology, psychiatry, and understanding the regulation of bodily defenses, applying evolutionary principles remains an open opportunity. In addition to the utility of specific applications, an evolutionary perspective fundamentally challenges the prevalent but fundamentally incorrect metaphor of the body as a machine designed by an engineer. Bodies are vulnerable to disease – and remarkably resilient – precisely because they are not machines built from a plan. They are, instead, bundles of compromises shaped by natural selection in small increments to maximize reproduction, not health. Understanding the body as a product of natural selection, not design, offers new research questions and a

  15. Evolutionary-based Design and Control of Geometry Aims for AMD-manufacturing of Ti-6Al-4V Parts

    NASA Astrophysics Data System (ADS)

    Möller, Mauritz; Baramsky, Nicolaj; Ewald, Ake; Emmelmann, Claus; Schlattmann, Josef

    Additive Metal Deposition (AMD) is an additive manufacturing process building parts based on a nozzle-fed powder by laser assisted solidification. The AMD technology offers unique advantages for the production of near net-shape parts. In contrast to the powder bed-based technologies it provides a high productivity grade. Today AMD lacks reproducible process strategies manufacturing large parts in narrow tolerances. The building height of a single layer and the geometrical shape of a whole part alter progressively with increasing part dimensions - consecutively leading to a higher effort in the manufacturing-process development for such parts. To reduce this effort, in this paper first an iterative identification of optimal process parameters is performed by following an evolutionary algorithm under varied BC. Based on the geometry-related parameter sets, tolerances are defined. The process strategies and tolerances are validated for a prototype application considering the defined quality aims. Finally the results are discussed and summarized in an a-priori process design guideline for AMD Ti6Al4V-parts.

  16. Design Principles of Nanoparticles as Contrast Agents for Magnetic Resonance Imaging

    NASA Astrophysics Data System (ADS)

    Shan, Liang; Gu, Xinbin; Wang, Paul

    2013-09-01

    Molecular imaging is an emerging field that introduces molecular agents into traditional imaging techniques, enabling visualization, characterization and measurement of biological processes at the molecular and cellular levels in humans and other living systems. The promise of molecular imaging lies in its potential for selective potency by targeting biomarkers or molecular targets and the imaging agents serve as reporters for the selectivity of targeting. Development of an efficient molecular imaging agent depends on well-controlled high-quality experiment design involving target selection, agent synthesis, in vitro characterization, and in vivo animal characterization before it is applied in humans. According to the analysis from the Molecular Imaging and Contrast Agent Database (MICAD, ), more than 6000 molecular imaging agents with sufficient preclinical evaluation have been reported to date in the literature and this number increases by 250-300 novel agents each year. The majority of these agents are radionuclides, which are developed for positron emission tomography (PET) and single photon emission computed tomography (SPECT). Contrast agents for magnetic resonance imaging (MRI) account for only a small part. This is largely due to the fact that MRI is currently not a fully quantitative imaging technique and is less sensitive than PET and SPECT. However, because of the superior ability to simultaneously extract molecular and anatomic information, molecular MRI is attracting significant interest and various targeted nanoparticle contrast agents have been synthesized for MRI. The first and one of the most critical steps in developing a targeted nanoparticle contrast agent is target selection, which plays the central role and forms the basis for success of molecular imaging. This chapter discusses the design principles of targeted contrast agents in the emerging frontiers of molecular MRI.

  17. Design principles for high-pressure force fields: Aqueous TMAO solutions from ambient to kilobar pressures.

    PubMed

    Hölzl, Christoph; Kibies, Patrick; Imoto, Sho; Frach, Roland; Suladze, Saba; Winter, Roland; Marx, Dominik; Horinek, Dominik; Kast, Stefan M

    2016-04-14

    Accurate force fields are one of the major pillars on which successful molecular dynamics simulations of complex biomolecular processes rest. They have been optimized for ambient conditions, whereas high-pressure simulations become increasingly important in pressure perturbation studies, using pressure as an independent thermodynamic variable. Here, we explore the design of non-polarizable force fields tailored to work well in the realm of kilobar pressures--while avoiding complete reparameterization. Our key is to first compute the pressure-induced electronic and structural response of a solute by combining an integral equation approach to include pressure effects on solvent structure with a quantum-chemical treatment of the solute within the embedded cluster reference interaction site model (EC-RISM) framework. Next, the solute's response to compression is taken into account by introducing pressure-dependence into selected parameters of a well-established force field. In our proof-of-principle study, the full machinery is applied to N,N,N-trimethylamine-N-oxide (TMAO) in water being a potent osmolyte that counteracts pressure denaturation. EC-RISM theory is shown to describe well the charge redistribution upon compression of TMAO(aq) to 10 kbar, which is then embodied in force field molecular dynamics by pressure-dependent partial charges. The performance of the high pressure force field is assessed by comparing to experimental and ab initio molecular dynamics data. Beyond its broad usefulness for designing non-polarizable force fields for extreme thermodynamic conditions, a good description of the pressure-response of solutions is highly recommended when constructing and validating polarizable force fields.

  18. Principles of appendage design in robots and animals determining terradynamic performance on flowable ground.

    PubMed

    Qian, Feifei; Zhang, Tingnan; Korff, Wyatt; Umbanhowar, Paul B; Full, Robert J; Goldman, Daniel I

    2015-10-08

    Natural substrates like sand, soil, leaf litter and snow vary widely in penetration resistance. To search for principles of appendage design in robots and animals that permit high performance on such flowable ground, we developed a ground control technique by which the penetration resistance of a dry granular substrate could be widely and rapidly varied. The approach was embodied in a device consisting of an air fluidized bed trackway in which a gentle upward flow of air through the granular material resulted in a decreased penetration resistance. As the volumetric air flow, Q, increased to the fluidization transition, the penetration resistance decreased to zero. Using a bio-inspired hexapedal robot as a physical model, we systematically studied how locomotor performance (average forward speed, v(x)) varied with ground penetration resistance and robot leg frequency. Average robot speed decreased with increasing Q, and decreased more rapidly for increasing leg frequency, ω. A universal scaling model revealed that the leg penetration ratio (foot pressure relative to penetration force per unit area per depth and leg length) determined v(x) for all ground penetration resistances and robot leg frequencies. To extend our result to include continuous variation of locomotor foot pressure, we used a resistive force theory based terradynamic approach to perform numerical simulations. The terradynamic model successfully predicted locomotor performance for low resistance granular states. Despite variation in morphology and gait, the performance of running lizards, geckos and crabs on flowable ground was also influenced by the leg penetration ratio. In summary, appendage designs which reduce foot pressure can passively maintain minimal leg penetration ratio as the ground weakens, and consequently permits maintenance of effective locomotion over a range of terradynamically challenging surfaces.

  19. CALL Design: Principles and Practice. Proceedings of the 2014 EUROCALL Conference (Groningen, The Netherlands, August 20-23, 2014)

    ERIC Educational Resources Information Center

    Jager, Sake, Ed.; Bradley, Linda, Ed.; Meima, Estelle J., Ed.; Thouësny, Sylvie, Ed.

    2014-01-01

    The theme of EUROCALL 2014 was "CALL Design: Principles and Practice," which attracted approximately 280 practitioners, researchers and students from computer-assisted language learning (CALL) and related disciplines of more than 40 different nationalities. Over 170 presentations were delivered on topics related to this overarching…

  20. Improving the Quality of Online Discussion: The Effects of Strategies Designed Based on Cognitive Load Theory Principles

    ERIC Educational Resources Information Center

    Darabi, Aubteen; Jin, Li

    2013-01-01

    This article focuses on heavy cognitive load as the reason for the lack of quality associated with conventional online discussion. Using the principles of cognitive load theory, four online discussion strategies were designed specifically aiming at reducing the discussants' cognitive load and thus enhancing the quality of their online discussion.…

  1. Design principle and calculations of a Scheffler fixed focus concentrator for medium temperature applications

    SciTech Connect

    Munir, A.; Hensel, O.; Scheffler, W.

    2010-08-15

    Scheffler fixed focus concentrators are successfully used for medium temperature applications in different parts of the world. These concentrators are taken as lateral sections of paraboloids and provide fixed focus away from the path of incident beam radiations throughout the year. The paper presents a complete description about the design principle and construction details of an 8 m{sup 2} surface area Scheffler concentrator. The first part of the paper presents the mathematical calculations to design the reflector parabola curve and reflector elliptical frame with respect to equinox (solar declination = 0) by selecting a specific lateral part of a paraboloid. Crossbar equations and their ellipses, arc lengths and their radii are also calculated to form the required lateral section of the paraboloid. Thereafter, the seasonal parabola equations are calculated for two extreme positions of summer and winter in the northern hemisphere (standing reflectors). The slopes of the parabola equations for equinox (solar declination = 0), summer (solar declination = +23.5) and winter (solar declination = -23.5) for the Scheffler reflector (8 m{sup 2} surface area) are calculated to be 0.17, 0.28, and 0.13 respectively. The y-intercepts of the parabola equations for equinox, summer and winter are calculated as 0, 0.54, and -0.53 respectively. By comparing with the equinox parabola curve, the summer parabola is found to be smaller in size and uses the top part of the parabola curve while the winter parabola is bigger in size and uses the lower part of the parabola curve to give the fixed focus. For this purpose, the reflector assembly is composed of flexible crossbars and a frame to induce the required change of the parabola curves with the changing solar declination. The paper also presents the calculation procedure of seasonal parabola equations for standing reflectors in the southern hemisphere as well as for laying reflectors in the northern and southern hemispheres. Highly

  2. Evolutionary Industrial Physical Model Generation

    NASA Astrophysics Data System (ADS)

    Carrascal, Alberto; Alberdi, Amaia

    Both complexity and lack of knowledge associated to physical processes makes physical models design an arduous task. Frequently, the only available information about the physical processes are the heuristic data obtained from experiments or at best a rough idea on what are the physical principles and laws that underlie considered physical processes. Then the problem is converted to find a mathematical expression which fits data. There exist traditional approaches to tackle the inductive model search process from data, such as regression, interpolation, finite element method, etc. Nevertheless, these methods either are only able to solve a reduced number of simple model typologies, or the given black-box solution does not contribute to clarify the analyzed physical process. In this paper a hybrid evolutionary approach to search complex physical models is proposed. Tests carried out on a real-world industrial physical process (abrasive water jet machining) demonstrate the validity of this approach.

  3. Dynamics and Design Principles of a Basic Regulatory Architecture Controlling Metabolic Pathways

    PubMed Central

    Jolly, Emmitt R; DeRisi, Joe; Li, Hao

    2008-01-01

    The dynamic features of a genetic network's response to environmental fluctuations represent essential functional specifications and thus may constrain the possible choices of network architecture and kinetic parameters. To explore the connection between dynamics and network design, we have analyzed a general regulatory architecture that is commonly found in many metabolic pathways. Such architecture is characterized by a dual control mechanism, with end product feedback inhibition and transcriptional regulation mediated by an intermediate metabolite. As a case study, we measured with high temporal resolution the induction profiles of the enzymes in the leucine biosynthetic pathway in response to leucine depletion, using an automated system for monitoring protein expression levels in single cells. All the genes in the pathway are known to be coregulated by the same transcription factors, but we observed drastically different dynamic responses for enzymes upstream and immediately downstream of the key control point—the intermediate metabolite α-isopropylmalate (αIPM), which couples metabolic activity to transcriptional regulation. Analysis based on genetic perturbations suggests that the observed dynamics are due to differential regulation by the leucine branch-specific transcription factor Leu3, and that the downstream enzymes are strictly controlled and highly expressed only when αIPM is available. These observations allow us to build a simplified mathematical model that accounts for the observed dynamics and can correctly predict the pathway's response to new perturbations. Our model also suggests that transient dynamics and steady state can be separately tuned and that the high induction levels of the downstream enzymes are necessary for fast leucine recovery. It is likely that principles emerging from this work can reveal how gene regulation has evolved to optimize performance in other metabolic pathways with similar architecture. PMID:18563967

  4. Unraveling Biological Design Principles Using Engineering Methods: The Heat Shock Response as a Case Study

    NASA Astrophysics Data System (ADS)

    El-Samad, Hana

    2006-03-01

    The bacterial heat shock response refers to the mechanism by which bacteria react to a sudden increase in the ambient temperature. The consequences of such an unmediated temperature increase at the cellular level is the unfolding, misfolding, or aggregation of cell proteins, which threatens the life of the cell. To combat such effects, cells have evolved an intricate set of feedback and feedforward mechanisms. In this talk, we present a mathematical model that describes the core functionality of these mechanisms. We illustrate how such a model provides valuable insight, explaining dynamic phenomena exhibited by wild type and mutant heat shock responses, corroborating experimental data and guiding novel biological experiments. Furthermore, we demonstrate, through the careful control analysis of the model, several design principles that appear to have shaped the feedback structure of the heat shock system. Specifically, we itemize the roles of the various feedback strategies and demonstrate their necessity in achieving performance objectives such as efficiency, robustness, stability, good transient response, and noise rejection in the presence of limited cellular energies and materials. Examined from this perspective, the heat shock model can be decomposed, both conceptually and mathematically, into functional modules. These modules possess the characteristics of more familiar modular structures: sensors, actuators and controllers present in a typical technological control system. We finally point to various theoretical research challenges inspired by the heat shock response system, and discuss the crucial relevance of these challenges in the modeling and analysis of many classes of systems that are likely to arise in the study of gene regulatory networks.

  5. Proton Management as a Design Principle for Hydrogenase-inspired Catalysts

    SciTech Connect

    Muckerman, J.T.; Small, Y.A.; DuBois, D.L.; Fujita, E.

    2011-08-01

    The properties of the hydrogenase-inspired [Ni(PNP){sub 2}]{sup 2+} (PNP = Et{sub 2}PCH{sub 2}NMeCH{sub 2}PEt{sub 2}) catalyst for homogeneous hydrogen oxidation in acetonitrile solution are explored from a theoretical perspective for hydrogen production. The defining characteristic of this catalyst is the presence of pendent bases in the second coordination sphere that function as proton relays between the solution and the metal center. DFT calculations of the possible intermediates along proposed catalytic pathways are carried out and used to construct coupled Pourbaix diagrams of the redox processes and free-energy profiles along the reaction pathways. Analysis of the coupled Pourbaix diagrams reveals insights into the intermediate species and the mechanisms favored at different pH values of the solution. Consideration of the acid-base behavior of the metal hydride and H{sub 2} adduct species imposes additional constraints on the reaction mechanism, which can involve intramolecular as well as intermolecular proton-coupled electron-transfer steps. The efficacy of the catalyst is shown to depend critically on the pK{sub a} values of these potential intermediates, as they control both the species in solution at a given pH and the free-energy profile of reaction pathways. Optimal relationships among these pK{sub a} values can be identified, and it is demonstrated that 'proton management', i.e., the manipulation of these pK{sub a} values (e.g., through choice of metal or substituents on ligands), can serve as a design principle for improved catalytic behavior.

  6. Guided-mode resonant filters and reflectors: Principles, design, and fabrication

    NASA Astrophysics Data System (ADS)

    Niraula, Manoj

    In this dissertation, we overview the operational principles of these resonant periodic structures, discuss the methods of their design and fabrication, and propose and demonstrate novel functionalities for spatial and spectral filtering, and unpolarized wideband reflection. Fashioned with materially sparse gratings, these optical devices are easy to fabricate and integration friendly compared to their traditional multi-layer counterparts making their research and development critical for practical applications. We study, theoretically, modal properties and parametric dependence of resonant periodic bandpass filters operating in the mid- and near-infrared spectral domains. We investigate three different device architectures consisting of single, double, and triple layers based on all-transparent dielectric and semiconductor thin films. We present three modal coupling configurations forming complex mixtures of two or three distinct leaky modes coupling at different evanescent diffraction orders. Our modal analysis demonstrates key attributes of subwavelength periodic thin-film structures in multiple-modal blending to achieve desired transmission spectra. We provide the first experimental demonstration of high-efficiency and narrow-linewidth resonant bandpass filter applying a single patterned silicon layer on a quartz substrate. Its performance corresponds to bandpass filters requiring 15 traditional Si/SiO2 thin-film layers. The feasibility of sparse narrowband, high-efficiency bandpass filters with extremely wide, flat, and low sidebands is thereby demonstrated. The proposed technology is integration-friendly and opens doors for further development in various disciplines and spectral regions where thin-film solutions are traditionally applied. We demonstrate concurrent spatial and spectral filtering as a new outstanding attribute of resonant periodic devices. This functionality is enabled by a unique, near-complete, reflection state that is discrete in both

  7. Design Principles for Covalent Organic Frameworks as Efficient Electrocatalysts in Clean Energy Conversion and Green Oxidizer Production.

    PubMed

    Lin, Chun-Yu; Zhang, Lipeng; Zhao, Zhenghang; Xia, Zhenhai

    2017-02-23

    Covalent organic frameworks (COFs), an emerging class of framework materials linked by covalent bonds, hold potential for various applications such as efficient electrocatalysts, photovoltaics, and sensors. To rationally design COF-based electrocatalysts for oxygen reduction and evolution reactions in fuel cells and metal-air batteries, activity descriptors, derived from orbital energy and bonding structures, are identified with the first-principle calculations for the COFs, which correlate COF structures with their catalytic activities. The calculations also predict that alkaline-earth metal-porphyrin COFs could catalyze the direct production of H2 O2 , a green oxidizer and an energy carrier. These predictions are supported by experimental data, and the design principles derived from the descriptors provide an approach for rational design of new electrocatalysts for both clean energy conversion and green oxidizer production.

  8. Incorporating café design principles into End-of-Life discussions: an innovative method for continuing education.

    PubMed

    Kanaskie, Mary Louise

    2011-04-01

    Café design provides an innovative method for conducting continuing education activities. This method was chosen to elicit meaningful conversation based on issues related to End-of-Life care. Café design principles incorporate the following: setting the context, creating hospitable space, exploring questions that matter, encouraging everyone's contributions, connecting diverse perspectives, listening together for insights, and sharing collective discoveries. Key discussion questions were identified from the End-of Life Nursing Education Consortium Core Curriculum. Questions were revised to incorporate the principles of appreciative inquiry, which encourage a shift from traditional methods of problem identification to creation of a positive vision. Participants rated the café design method as an effective way to share their ideas and to stimulate conversation.

  9. Design principles and common pool resource management: an institutional approach to evaluating community management in semi-arid Tanzania.

    PubMed

    Quinn, Claire H; Huby, Meg; Kiwasila, Hilda; Lovett, Jon C

    2007-07-01

    This paper analyses the role of institutions in the management of common pool resources (CPRs) in semi-arid Tanzania. Common property regimes have often been considered inadequate for the management of CPRs because of the problems of excludability, but they are becoming more widely supported as the way forward to overcome the problems of resource use and degradation in developing countries. A series of design principles for long enduring common property institutions have been proposed by Ostrom, but there is concern that they are not applicable to a wide range of real life situations or that they may be specific to certain types of CPR. Here, we compare these principles to the situation prevailing in 12 villages in six districts in semi-arid Tanzania. Data on management institutions were collected through semi-structured interviews and meetings at district and village level. The combined information was used to make a qualitative assessment of the strength with which each design principle appeared to operate in the management of forest, pasture and water resources. Boundaries, conflict and negotiation in CPR management are of key importance in semi-arid regions. However, the need for flexibility in order to deal with ecological uncertainty means that many management institutions would be considered weak or absent according to the design principle approach. This supports the view that the design principles should not be used as a 'blueprint to be imposed on resource management regimes' rather that they provide a framework for investigating common property regimes with the proviso that, certainly for semi-arid regions, they may highlight where management cannot be explained by institutional theory alone.

  10. A framework for evolutionary systems biology

    PubMed Central

    Loewe, Laurence

    2009-01-01

    Background Many difficult problems in evolutionary genomics are related to mutations that have weak effects on fitness, as the consequences of mutations with large effects are often simple to predict. Current systems biology has accumulated much data on mutations with large effects and can predict the properties of knockout mutants in some systems. However experimental methods are too insensitive to observe small effects. Results Here I propose a novel framework that brings together evolutionary theory and current systems biology approaches in order to quantify small effects of mutations and their epistatic interactions in silico. Central to this approach is the definition of fitness correlates that can be computed in some current systems biology models employing the rigorous algorithms that are at the core of much work in computational systems biology. The framework exploits synergies between the realism of such models and the need to understand real systems in evolutionary theory. This framework can address many longstanding topics in evolutionary biology by defining various 'levels' of the adaptive landscape. Addressed topics include the distribution of mutational effects on fitness, as well as the nature of advantageous mutations, epistasis and robustness. Combining corresponding parameter estimates with population genetics models raises the possibility of testing evolutionary hypotheses at a new level of realism. Conclusion EvoSysBio is expected to lead to a more detailed understanding of the fundamental principles of life by combining knowledge about well-known biological systems from several disciplines. This will benefit both evolutionary theory and current systems biology. Understanding robustness by analysing distributions of mutational effects and epistasis is pivotal for drug design, cancer research, responsible genetic engineering in synthetic biology and many other practical applications. PMID:19239699

  11. Recommendations for sex/gender neuroimaging research: key principles and implications for research design, analysis, and interpretation.

    PubMed

    Rippon, Gina; Jordan-Young, Rebecca; Kaiser, Anelis; Fine, Cordelia

    2014-01-01

    Neuroimaging (NI) technologies are having increasing impact in the study of complex cognitive and social processes. In this emerging field of social cognitive neuroscience, a central goal should be to increase the understanding of the interaction between the neurobiology of the individual and the environment in which humans develop and function. The study of sex/gender is often a focus for NI research, and may be motivated by a desire to better understand general developmental principles, mental health problems that show female-male disparities, and gendered differences in society. In order to ensure the maximum possible contribution of NI research to these goals, we draw attention to four key principles-overlap, mosaicism, contingency and entanglement-that have emerged from sex/gender research and that should inform NI research design, analysis and interpretation. We discuss the implications of these principles in the form of constructive guidelines and suggestions for researchers, editors, reviewers and science communicators.

  12. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume V. Vacuum-pumping system. Preliminary design report

    SciTech Connect

    Not Available

    1982-02-26

    This report summarizes Title I Preliminary Design of the EBT-P Vacuum Pumping System. The Vacuum Pumping System has been designed by the McDonnell Douglas Astronautics Co. - St. Louis (MDAC). It includes the necessary vacuum pumps and vacuum valves to evacuate the torus, the Mirror Coil Dewars (MC Dewars), and the Gyrotron Magnet Dewars. The pumping ducts, manifolds, and microwave protection system are also included. A summary of the function of each subsystem and a description of its principle components is provided below. The analyses performed during the system design are also identified.

  13. Evolutionary behavioral genetics

    PubMed Central

    Zietsch, Brendan P.; de Candia, Teresa R; Keller, Matthew C.

    2014-01-01

    We describe the scientific enterprise at the intersection of evolutionary psychology and behavioral genetics—a field that could be termed Evolutionary Behavioral Genetics—and how modern genetic data is revolutionizing our ability to test questions in this field. We first explain how genetically informative data and designs can be used to investigate questions about the evolution of human behavior, and describe some of the findings arising from these approaches. Second, we explain how evolutionary theory can be applied to the investigation of behavioral genetic variation. We give examples of how new data and methods provide insight into the genetic architecture of behavioral variation and what this tells us about the evolutionary processes that acted on the underlying causal genetic variants. PMID:25587556

  14. Applying human factors principles to alert design increases efficiency and reduces prescribing errors in a scenario-based simulation

    PubMed Central

    Russ, Alissa L; Zillich, Alan J; Melton, Brittany L; Russell, Scott A; Chen, Siying; Spina, Jeffrey R; Weiner, Michael; Johnson, Elizabette G; Daggy, Joanne K; McManus, M Sue; Hawsey, Jason M; Puleo, Anthony G; Doebbeling, Bradley N; Saleem, Jason J

    2014-01-01

    Objective To apply human factors engineering principles to improve alert interface design. We hypothesized that incorporating human factors principles into alerts would improve usability, reduce workload for prescribers, and reduce prescribing errors. Materials and methods We performed a scenario-based simulation study using a counterbalanced, crossover design with 20 Veterans Affairs prescribers to compare original versus redesigned alerts. We redesigned drug–allergy, drug–drug interaction, and drug–disease alerts based upon human factors principles. We assessed usability (learnability of redesign, efficiency, satisfaction, and usability errors), perceived workload, and prescribing errors. Results Although prescribers received no training on the design changes, prescribers were able to resolve redesigned alerts more efficiently (median (IQR): 56 (47) s) compared to the original alerts (85 (71) s; p=0.015). In addition, prescribers rated redesigned alerts significantly higher than original alerts across several dimensions of satisfaction. Redesigned alerts led to a modest but significant reduction in workload (p=0.042) and significantly reduced the number of prescribing errors per prescriber (median (range): 2 (1–5) compared to original alerts: 4 (1–7); p=0.024). Discussion Aspects of the redesigned alerts that likely contributed to better prescribing include design modifications that reduced usability-related errors, providing clinical data closer to the point of decision, and displaying alert text in a tabular format. Displaying alert text in a tabular format may help prescribers extract information quickly and thereby increase responsiveness to alerts. Conclusions This simulation study provides evidence that applying human factors design principles to medication alerts can improve usability and prescribing outcomes. PMID:24668841

  15. Evolutionary thinking

    PubMed Central

    Hunt, Tam

    2014-01-01

    Evolution as an idea has a lengthy history, even though the idea of evolution is generally associated with Darwin today. Rebecca Stott provides an engaging and thoughtful overview of this history of evolutionary thinking in her 2013 book, Darwin's Ghosts: The Secret History of Evolution. Since Darwin, the debate over evolution—both how it takes place and, in a long war of words with religiously-oriented thinkers, whether it takes place—has been sustained and heated. A growing share of this debate is now devoted to examining how evolutionary thinking affects areas outside of biology. How do our lives change when we recognize that all is in flux? What can we learn about life more generally if we study change instead of stasis? Carter Phipps’ book, Evolutionaries: Unlocking the Spiritual and Cultural Potential of Science's Greatest Idea, delves deep into this relatively new development. Phipps generally takes as a given the validity of the Modern Synthesis of evolutionary biology. His story takes us into, as the subtitle suggests, the spiritual and cultural implications of evolutionary thinking. Can religion and evolution be reconciled? Can evolutionary thinking lead to a new type of spirituality? Is our culture already being changed in ways that we don't realize by evolutionary thinking? These are all important questions and Phipps book is a great introduction to this discussion. Phipps is an author, journalist, and contributor to the emerging “integral” or “evolutionary” cultural movement that combines the insights of Integral Philosophy, evolutionary science, developmental psychology, and the social sciences. He has served as the Executive Editor of EnlightenNext magazine (no longer published) and more recently is the co-founder of the Institute for Cultural Evolution, a public policy think tank addressing the cultural roots of America's political challenges. What follows is an email interview with Phipps. PMID:26478766

  16. Teaching students to think spatially through embodied actions: Design principles for learning environments in science, technology, engineering, and mathematics.

    PubMed

    DeSutter, D; Stieff, M

    2017-01-01

    Spatial thinking is a vital component of the science, technology, engineering, and mathematics curriculum. However, to date, broad development of learning environments that target domain-specific spatial thinking is incomplete. The present article visits the problem of improving spatial thinking by first reviewing the evidence that the human mind is embodied: that cognition, memory, and knowledge representation maintain traces of sensorimotor impressions from acting and perceiving in a physical environment. In particular, we review the evidence that spatial cognition and the ways that humans perceive and conceive of space are embodied. We then propose a set of design principles to aid researchers, designers, and practitioners in creating and evaluating learning environments that align principled embodied actions to targets of spatial thinking in science, technology, engineering, and mathematics.

  17. Applications of electromagnetic principles in the design and development of proximity wireless sensors

    NASA Astrophysics Data System (ADS)

    Alam, Md Nazmul

    Sensors and sensing system are playing dominant roles in monitoring the health of infrastructure, such as bridges, power lines, gas pipelines, rail roads etc. Sensing modalities employing Surface Acoustic Waves (SAW), Electromagnetic (EM) and optical have been investigated and reported. Sensors that utilize the perturbation of EM fields as function of the change in the physical structural or material phenomenon are of particular interest because of their inherent synergy with electronic system and diagnostic techniques, e.g. Time Domain Reflectometry (TDR), Joint-Time-Frequency-Domain-Reflectometry (JTFDR). The focus of this work is to study and develop new sensing and monitoring concepts that are based on EM principles. First, the analyses, design and development of a static electric field type sensor are presented for application in embedded concrete moisture content measurement. The analytical formulation and results based on conformal mapping method for an interdigitated sensor clearly show the dependency of the field penetration depth and the inter-electrode capacitance on the electrode sizes and their spacings. It is observed that larger electrode size and small separation are needed in order to achieve substantially higher capacitance or large field penetration depth. A meander and a circular sensor are fabricated and tested to demonstrate concrete moisture content measurements that show that moisture content is a linear function of sensor interelectrode capacitance. Second, sub-wavelength dimension non-intrusive wave launchers are designed and tested that can launch TDR or JTFDR type broadband surface wave waveforms in the VHF-UHF bands in order to detect cable faults. Greater than 3:1 transmission bandwidth (100-300 MHz) is obtained with a cylindrical launcher on square orthogonal ground plane while with a CSW launcher more than an octave (100-240 MHz) bandwidth is achieved. Open circuit faults are detected using surface waves and TDR on two XLPE cables

  18. Framework for Asynchronous Discussion Design Decisions: Applied Principles from Special Issue Authors

    ERIC Educational Resources Information Center

    Grabowski, Barbara L.

    2011-01-01

    After a discussion of the state of both misaligned and informative online and distance education research, the authors in this special issue (hereafter called the collective) extract evidence-based principles about strategies that work. Both are addressed in this article. First, their criticisms centered on the value of comparative research. Those…

  19. Using Instructional Design Principles To Amplify Learning on the World Wide Web.

    ERIC Educational Resources Information Center

    Ritchie, Donn C.; Hoffman, Bob

    Many educators have explored the World Wide Web, and some are now publishing their own materials for student access. Throughout the brief history of the Web, the overriding educational principle has been to view this resource as a storehouse of information which provides unparalleled avenues of research. The potential for the Web, however, is…

  20. Using Principles of Learning to Inform Language Therapy Design for Children with Specific Language Impairment

    ERIC Educational Resources Information Center

    Alt, Mary; Meyers, Christina; Ancharski, Alexandra

    2012-01-01

    Background: 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. Aims: To outline some key findings about learning in typical populations and to suggest a model of how…

  1. Application of Multimedia Design Principles to Visuals Used in Course-Books: An Evaluation Tool

    ERIC Educational Resources Information Center

    Kuzu, Abdullah; Akbulut, Yavuz; Sahin, Mehmet Can

    2007-01-01

    This paper introduces an evaluation tool prepared to examine the quality of visuals in course-books. The tool is based on Mayer's Cognitive Theory of Multimedia Learning (i.e. Generative Theory) and its principles regarding the correct use of illustrations within text. The reason to generate the tool, the development process along with the…

  2. Engineering microbial systems to explore ecological and evolutionary dynamics.

    PubMed

    Tanouchi, Yu; Smith, Robert P; You, Lingchong

    2012-10-01

    A major goal of biological research is to provide a mechanistic understanding of diverse biological processes. To this end, synthetic biology offers a powerful approach, whereby biological questions can be addressed in a well-defined framework. By constructing simple gene circuits, such studies have generated new insights into the design principles of gene regulatory networks. Recently, this strategy has been applied to analyze ecological and evolutionary questions, where population-level interactions are critical. Here, we highlight recent development of such systems and discuss how they were used to address problems in ecology and evolutionary biology. As illustrated by these examples, synthetic ecosystems provide a unique platform to study ecological and evolutionary phenomena that are challenging to study in their natural contexts.

  3. A novel driving principle by means of the parasitic motion of the microgripper and its preliminary application in the design of the linear actuator

    NASA Astrophysics Data System (ADS)

    Huang, Hu; Zhao, Hongwei; Yang, Zhaojun; Mi, Jie; Fan, Zunqiang; Wan, Shunguang; Shi, Chengli; Ma, Zhichao

    2012-05-01

    This paper presents a novel driving principle by means of the parasitic motion of the microgripper. Actuators based on this principle can realize the large displacement range and high speed easily. Also the structure can be simple. A parasitic motion principle linear actuator mainly consisting of two piezoelectric stacks, two microgrippers and a mover was designed. Experimental results indicate that at a low driving frequency of 5 Hz, large velocity over 40 μm/s is obtained with the driving voltage of 100 V. Backward motion was observed and analyzed. Experimental results verify the feasibility of the new principle and it can be used to design new linear or rotary actuators.

  4. First Principles and Genetic Algorithm Studies of Lanthanide Metal Oxides for Optimal Fuel Cell Electrolyte Design

    NASA Astrophysics Data System (ADS)

    Ismail, Arif

    As the demand for clean and renewable energy sources continues to grow, much attention has been given to solid oxide fuel cells (SOFCs) due to their efficiency and low operating temperature. However, the components of SOFCs must still be improved before commercialization can be reached. Of particular interest is the solid electrolyte, which conducts oxygen ions from the cathode to the anode. Samarium-doped ceria (SDC) is the electrolyte of choice in most SOFCs today, due mostly to its high ionic conductivity at low temperatures. However, the underlying principles that contribute to high ionic conductivity in doped ceria remain unknown, and so it is difficult to improve upon the design of SOFCs. This thesis focuses on identifying the atomistic interactions in SDC which contribute to its favourable performance in the fuel cell. Unfortunately, information as basic as the structure of SDC has not yet been found due to the difficulty in experimentally characterizing and computationally modelling the system. For instance, to evaluate 10.3% SDC, which is close to the 11.1% concentration used in fuel cells, one must investigate 194 trillion configurations, due to the numerous ways of arranging the Sm ions and oxygen vacancies in the simulation cell. As an exhaustive search method is clearly unfeasible, we develop a genetic algorithm (GA) to search the vast potential energy surface for the low-energy configurations, which will be most prevalent in the real material. With the GA, we investigate the structure of SDC for the first time at the DFT+U level of theory. Importantly, we find key differences in our results from prior calculations of this system which used less accurate methods, which demonstrate the importance of accurately modelling the system. Overall, our simulation results of the structure of SDC agree with experimental measurements. We identify the structural significance of defects in the doped ceria lattice which contribute to oxygen ion conductivity. Thus

  5. Metal-insulator-metal diodes towards THz and optical energy harvesting: Development of materials design principles

    NASA Astrophysics Data System (ADS)

    Periasamy, Prakash

    Metal-Insulator-Metal (MIM) structures are attractive candidates for high-frequency rectification applications such as THz imaging and sensors, and infrared/visible energy harvesting (rectenna) devices. This thesis develops materials selection principles to guide the choice of material pairs for MIM stacks with desired rectification performance. In particular, a first-of-its kind MIM materials space map is developed that correlates materials properties to rectification performance for different MIM combinations. The materials space diagram is generated based on systematic experimental studies that explore the role of both the metals and the insulator in the MIM stack in determining MIM device performance by evaluating the current-voltage response of a combinatorial set of MIM materials at low frequencies. A novel modified point-contact geometry is developed to rapidly examine a number of MIM material combinations. Material properties such as work function (phiM) of the metals and electron affinity (chi) of the insulator, as well as the thermodynamic chemical stability of the interface are identified as crucial elements for MIM materials selection. Investigations performed to identify the role of metals revealed that it is sufficient to choose the metals such that their Deltaphi is > ~ 300 meV to achieve desired rectification characteristics (high asymmetry and nonlinearity). Using the Nb/Nb2O5 bilayer as the model system, the asymmetry and the nonlinearity were found to be only weakly dependent on Deltaphi above ˜ 0.4 eV. A hypothesis is developed and tested that guides the insulator selection criteria. The proposed hypothesis states that, "to minimize the turn-on voltage and maximize asymmetry and nonlinearity, the electron affinity of the insulator should be close to one of the metal work function values so as to produce a low barrier height". Although the study validated the hypothesis across the material systems studied, preliminary experiments on two

  6. Integrating Evolutionary Game Theory into Mechanistic Genotype-Phenotype Mapping.

    PubMed

    Zhu, Xuli; Jiang, Libo; Ye, Meixia; Sun, Lidan; Gragnoli, Claudia; Wu, Rongling

    2016-05-01

    Natural selection has shaped the evolution of organisms toward optimizing their structural and functional design. However, how this universal principle can enhance genotype-phenotype mapping of quantitative traits has remained unexplored. Here we show that the integration of this principle and functional mapping through evolutionary game theory gains new insight into the genetic architecture of complex traits. By viewing phenotype formation as an evolutionary system, we formulate mathematical equations to model the ecological mechanisms that drive the interaction and coordination of its constituent components toward population dynamics and stability. Functional mapping provides a procedure for estimating the genetic parameters that specify the dynamic relationship of competition and cooperation and predicting how genes mediate the evolution of this relationship during trait formation.

  7. Evolutionary developmental psychology.

    PubMed

    King, Ashley C; Bjorklund, David F

    2010-02-01

    The field of evolutionary developmental psychology can potentially broaden the horizons of mainstream evolutionary psychology by combining the principles of Darwinian evolution by natural selection with the study of human development, focusing on the epigenetic effects that occur between humans and their environment in a way that attempts to explain how evolved psychological mechanisms become expressed in the phenotypes of adults. An evolutionary developmental perspective includes an appreciation of comparative research and we, among others, argue that contrasting the cognition of humans with that of nonhuman primates can provide a framework with which to understand how human cognitive abilities and intelligence evolved. Furthermore, we argue that several aspects of childhood (e.g., play and immature cognition) serve both as deferred adaptations as well as imparting immediate benefits. Intense selection pressure was surely exerted on childhood over human evolutionary history and, as a result, neglecting to consider the early developmental period of children when studying their later adulthood produces an incomplete picture of the evolved adaptations expressed through human behavior and cognition.

  8. Recommendations for sex/gender neuroimaging research: key principles and implications for research design, analysis, and interpretation

    PubMed Central

    Rippon, Gina; Jordan-Young, Rebecca; Kaiser, Anelis; Fine, Cordelia

    2014-01-01

    Neuroimaging (NI) technologies are having increasing impact in the study of complex cognitive and social processes. In this emerging field of social cognitive neuroscience, a central goal should be to increase the understanding of the interaction between the neurobiology of the individual and the environment in which humans develop and function. The study of sex/gender is often a focus for NI research, and may be motivated by a desire to better understand general developmental principles, mental health problems that show female-male disparities, and gendered differences in society. In order to ensure the maximum possible contribution of NI research to these goals, we draw attention to four key principles—overlap, mosaicism, contingency and entanglement—that have emerged from sex/gender research and that should inform NI research design, analysis and interpretation. We discuss the implications of these principles in the form of constructive guidelines and suggestions for researchers, editors, reviewers and science communicators. PMID:25221493

  9. Using in-cell SHAPE-Seq and simulations to probe structure–function design principles of RNA transcriptional regulators

    PubMed Central

    Takahashi, Melissa K.; Watters, Kyle E.; Gasper, Paul M.; Abbott, Timothy R.; Carlson, Paul D.; Chen, Alan A.

    2016-01-01

    Antisense RNA-mediated transcriptional regulators are powerful tools for controlling gene expression and creating synthetic gene networks. RNA transcriptional repressors derived from natural mechanisms called attenuators are particularly versatile, though their mechanistic complexity has made them difficult to engineer. Here we identify a new structure–function design principle for attenuators that enables the forward engineering of new RNA transcriptional repressors. Using in-cell SHAPE-Seq to characterize the structures of attenuator variants within Escherichia coli, we show that attenuator hairpins that facilitate interaction with antisense RNAs require interior loops for proper function. Molecular dynamics simulations of these attenuator variants suggest these interior loops impart structural flexibility. We further observe hairpin flexibility in the cellular structures of natural RNA mechanisms that use antisense RNA interactions to repress translation, confirming earlier results from in vitro studies. Finally, we design new transcriptional attenuators in silico using an interior loop as a structural requirement and show that they function as desired in vivo. This work establishes interior loops as an important structural element for designing synthetic RNA gene regulators. We anticipate that the coupling of experimental measurement of cellular RNA structure and function with computational modeling will enable rapid discovery of structure–function design principles for a diverse array of natural and synthetic RNA regulators. PMID:27103533

  10. Evolutionary Determinants of Cancer

    PubMed Central

    Greaves, Mel

    2015-01-01

    ‘Nothing in biology makes sense except in the light of evolution’ Th. Dobzhansky, 1973 Our understanding of cancer is being transformed by exploring clonal diversity, drug resistance and causation within an evolutionary framework. The therapeutic resilience of advanced cancer is a consequence of its character as complex, dynamic and adaptive ecosystem engendering robustness, underpinned by genetic diversity and epigenetic plasticity. The risk of mutation-driven escape by self-renewing cells is intrinsic to multicellularity but is countered by multiple restraints facilitating increasing complexity and longevity of species. But our own has disrupted this historical narrative by rapidly escalating intrinsic risk. Evolutionary principles illuminate these challenges and provide new avenues to explore for more effective control. PMID:26193902

  11. On evolutionary systems.

    PubMed

    Alvarez de Lorenzana, J M; Ward, L M

    1987-01-01

    This paper develops a metatheoretical framework for understanding evolutionary systems (systems that develop in ways that increase their own variety). The framework addresses shortcomings seen in other popular systems theories. It concerns both living and nonliving systems, and proposes a metahierarchy of hierarchical systems. Thus, it potentially addresses systems at all descriptive levels. We restrict our definition of system to that of a core system whose parts have a different ontological status than the system, and characterize the core system in terms of five global properties: minimal length interval, minimal time interval, system cycle, total receptive capacity, and system potential. We propose two principles through the interaction of which evolutionary systems develop. The Principle of Combinatorial Expansion describes how a core system realizes its developmental potential through a process of progressive differentiation of the single primal state up to a limit stage. The Principle of Generative Condensation describes how the components of the last stage of combinatorial expansion condense and become the environment for and components of new, enriched systems. The early evolution of the Universe after the "big bang" is discussed in light of these ideas as an example of the application of the framework.

  12. Design Principles and Practices for Implementation of MIL-STD-1760 in Aircraft and Stores

    DTIC Science & Technology

    1987-06-01

    its crew. Without some limitattons on the amount of fault induced energy which can be dumped into the store , it is considered not practical for the...TIC FJILE COP’ ASD-TR-87-5028 AD-A 183 724 ’ DISIGN PRINCIPLES AND PRACTICES FO’Z IMPLEMENTATION OF MZL-STD-1760 IN AIRCRAFT AND STORES .•AUG 3 1 a...il Aircraft an Stores 12. PERSONAL AUTHOR(S) TIP.- T.mirnpr.. A-..J. Marpk. -JM- Dritm- R..R- EPrnqr.,dez 13a. TYPE OF REPORT 3.TIME COVERED 14. DATE

  13. Design Principles as a Guide for Constraint Based and Dynamic Modeling: Towards an Integrative Workflow

    PubMed Central

    Sehr, Christiana; Kremling, Andreas; Marin-Sanguino, Alberto

    2015-01-01

    During the last 10 years, systems biology has matured from a fuzzy concept combining omics, mathematical modeling and computers into a scientific field on its own right. In spite of its incredible potential, the multilevel complexity of its objects of study makes it very difficult to establish a reliable connection between data and models. The great number of degrees of freedom often results in situations, where many different models can explain/fit all available datasets. This has resulted in a shift of paradigm from the initially dominant, maybe naive, idea of inferring the system out of a number of datasets to the application of different techniques that reduce the degrees of freedom before any data set is analyzed. There is a wide variety of techniques available, each of them can contribute a piece of the puzzle and include different kinds of experimental information. But the challenge that remains is their meaningful integration. Here we show some theoretical results that enable some of the main modeling approaches to be applied sequentially in a complementary manner, and how this workflow can benefit from evolutionary reasoning to keep the complexity of the problem in check. As a proof of concept, we show how the synergies between these modeling techniques can provide insight into some well studied problems: Ammonia assimilation in bacteria and an unbranched linear pathway with end-product inhibition. PMID:26501332

  14. Examining the Use of First Principles of Instruction by Instructional Designers in a Short-Term, High Volume, Rapid Production of Online K-12 Teacher Professional Development Modules

    ERIC Educational Resources Information Center

    Mendenhall, Anne M.

    2012-01-01

    Merrill (2002a) created a set of fundamental principles of instruction that can lead to effective, efficient, and engaging (e[superscript 3]) instruction. The First Principles of Instruction (Merrill, 2002a) are a prescriptive set of interrelated instructional design practices that consist of activating prior knowledge, using specific portrayals…

  15. On extracting design principles from biology: II. Case study-the effect of knee direction on bipedal robot running efficiency.

    PubMed

    Haberland, M; Kim, S

    2015-02-02

    Comparing the leg of an ostrich to that of a human suggests an important question to legged robot designers: should a robot's leg joint bend in the direction of running ('forwards') or opposite ('backwards')? Biological studies cannot answer this question for engineers due to significant differences between the biological and engineering domains. Instead, we investigated the inherent effect of joint bending direction on bipedal robot running efficiency by comparing energetically optimal gaits of a wide variety of robot designs sampled at random from a design space. We found that the great majority of robot designs have several locally optimal gaits with the knee bending backwards that are more efficient than the most efficient gait with the knee bending forwards. The most efficient backwards gaits do not exhibit lower touchdown losses than the most efficient forward gaits; rather, the improved efficiency of backwards gaits stems from lower torque and reduced motion at the hip. The reduced hip use of backwards gaits is enabled by the ability of the backwards knee, acting alone, to (1) propel the robot upwards and forwards simultaneously and (2) lift and protract the foot simultaneously. In the absence of other information, designers interested in building efficient bipedal robots with two-segment legs driven by electric motors should design the knee to bend backwards rather than forwards. Compared to common practices for choosing robot knee direction, application of this principle would have a strong tendency to improve robot efficiency and save design resources.

  16. Ecological and evolutionary traps

    USGS Publications Warehouse

    Schlaepfer, Martin A.; Runge, M.C.; Sherman, P.W.

    2002-01-01

    Organisms often rely on environmental cues to make behavioral and life-history decisions. However, in environments that have been altered suddenly by humans, formerly reliable cues might no longer be associated with adaptive outcomes. In such cases, organisms can become 'trapped' by their evolutionary responses to the cues and experience reduced survival or reproduction. Ecological traps occur when organisms make poor habitat choices based on cues that correlated formerly with habitat quality. Ecological traps are part of a broader phenomenon, evolutionary traps, involving a dissociation between cues that organisms use to make any behavioral or life-history decision and outcomes normally associated with that decision. A trap can lead to extinction if a population falls below a critical size threshold before adaptation to the novel environment occurs. Conservation and management protocols must be designed in light of, rather than in spite of, the behavioral mechanisms and evolutionary history of populations and species to avoid 'trapping' them.

  17. Design principles for innovative workspaces to increase efficiency in pharmaceutical R&D: lessons learned from the Novartis campus.

    PubMed

    Zoller, Frank A; Boutellier, Roman

    2013-04-01

    When managing R&D departments for increased efficiency and effectiveness the focus has often been on organizational structure. Space is, however, of outstanding importance in an environment of large task uncertainty, which is the case in pharmaceutical R&D. Based on case studies about the Novartis campus in Basel, Switzerland, we propose some design principles for laboratory and office workspace to support the strong and weak ties of scientist networks. We address the diversity of technologies and specialization, as well as the pressure on time-to-market, as major challenges in pharmaceutical R&D.

  18. The Crisis in Astrophysics and Planetary Science: How Commercial Space and Program Design Principles will let us Escape

    NASA Astrophysics Data System (ADS)

    Elvis, Martin

    2017-01-01

    Astrophysics and planetary science are in crisis. The large missions we need for the next generation of observations cost too much to let us do more than one at a time. This spreads the science out onto a generational timescale, inhibiting progress in both fields. There are two escape paths. In the long run, but still well within our planning horizon, commercial space will bring mission costs down substantially allowing parallel missions at multiple wavelengths or to multiple destinations. In the short run, adopting prudent principles for designing a research program will let us maintain vitality in the field by retaining breadth at a modest cost in depth.

  19. Applying Evolutionary Anthropology

    PubMed Central

    Gibson, Mhairi A; Lawson, David W

    2015-01-01

    Evolutionary anthropology provides a powerful theoretical framework for understanding how both current environments and legacies of past selection shape human behavioral diversity. This integrative and pluralistic field, combining ethnographic, demographic, and sociological methods, has provided new insights into the ultimate forces and proximate pathways that guide human adaptation and variation. Here, we present the argument that evolutionary anthropological studies of human behavior also hold great, largely untapped, potential to guide the design, implementation, and evaluation of social and public health policy. Focusing on the key anthropological themes of reproduction, production, and distribution we highlight classic and recent research demonstrating the value of an evolutionary perspective to improving human well-being. The challenge now comes in transforming relevance into action and, for that, evolutionary behavioral anthropologists will need to forge deeper connections with other applied social scientists and policy-makers. We are hopeful that these developments are underway and that, with the current tide of enthusiasm for evidence-based approaches to policy, evolutionary anthropology is well positioned to make a strong contribution. PMID:25684561

  20. Applying evolutionary anthropology.

    PubMed

    Gibson, Mhairi A; Lawson, David W

    2015-01-01

    Evolutionary anthropology provides a powerful theoretical framework for understanding how both current environments and legacies of past selection shape human behavioral diversity. This integrative and pluralistic field, combining ethnographic, demographic, and sociological methods, has provided new insights into the ultimate forces and proximate pathways that guide human adaptation and variation. Here, we present the argument that evolutionary anthropological studies of human behavior also hold great, largely untapped, potential to guide the design, implementation, and evaluation of social and public health policy. Focusing on the key anthropological themes of reproduction, production, and distribution we highlight classic and recent research demonstrating the value of an evolutionary perspective to improving human well-being. The challenge now comes in transforming relevance into action and, for that, evolutionary behavioral anthropologists will need to forge deeper connections with other applied social scientists and policy-makers. We are hopeful that these developments are underway and that, with the current tide of enthusiasm for evidence-based approaches to policy, evolutionary anthropology is well positioned to make a strong contribution.

  1. 77 FR 36611 - Core Principles and Other Requirements for Designated Contract Markets

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ... and Other Requirements for Designated Contract Markets; Final Rule #0;#0;Federal Register / Vol. 77... Contract Markets AGENCY: Commodity Futures Trading Commission. ACTION: Final rule. SUMMARY: The Commodity... practices, which apply to the designation and operation of contract markets, implement the Dodd-Frank...

  2. 78 FR 32988 - Core Principles and Other Requirements for Designated Contract Markets; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-03

    ... Markets; Correction AGENCY: Commodity Futures Trading Commission. ACTION: Final rule; correction. SUMMARY... Other Requirements for Designated Contract Markets by inserting a missing instruction to add Appendix C... and Other Requirements for Designated Contract Markets (77 FR 36612, June 19, 2012). The final...

  3. Design-Based Research Principles for Student Orientation to Online Study: Capturing the Lessons Learnt

    ERIC Educational Resources Information Center

    Wozniak, Helen; Pizzica, Jenny; Mahony, Mary Jane

    2012-01-01

    Few institutions have reported research on students' "use" of orientation programs designed for mature students returning to study in contemporary learning environments now regularly amalgamating distance and online strategies. We report within a design-based research framework the student experience of "GetLearning," the third…

  4. The Structuration of Blended Learning: Putting Holistic Design Principles into Practice

    ERIC Educational Resources Information Center

    Stubbs, Mark; Martin, Ian; Endlar, Lewis

    2006-01-01

    This paper considers the challenges faced by those seeking to design effective blended learning. Using a 2-year case study involving cohorts of approximately 200 students, it demonstrates how Anthony Giddens structuration theory can provide a metaframework for assisting educational designers in creating coherent blended learning experiences that…

  5. Sustainability as a Design Principle for Composition: Situational Creativity as a Habit of Mind

    ERIC Educational Resources Information Center

    Newcomb, Matthew

    2012-01-01

    Design is a rhetorical activity that requires creative thinking in response to difficult situations. That creative work ultimately builds new relationships and new contexts. Sustainable design can become an approach to composition that alters ways of thinking about writing situations, keeping ethical and contextual factors in focus, and…

  6. Intentional Teaching, Intentional Scholarship: Applying Backward Design Principles in a Faculty Writing Group

    ERIC Educational Resources Information Center

    Linder, Kathryn E.; Cooper, Frank Rudy; McKenzie, Elizabeth M.; Raesch, Monika; Reeve, Patricia A.

    2014-01-01

    Backward design is a course creation method that encourages teachers to identify their goals for student understanding and measurable objectives for learning from the outset. In this article we explore the application of backward design to the production of scholarly articles. Specifically, we report on a writing group program that encourages…

  7. On the design of neuro-controllers for individual and social learning behaviour in autonomous robots: an evolutionary approach

    NASA Astrophysics Data System (ADS)

    Pini, Giovanni; Tuci, Elio

    2008-06-01

    In biology/psychology, the capability of natural organisms to learn from the observation/interaction with conspecifics is referred to as social learning. Roboticists have recently developed an interest in social learning, since it might represent an effective strategy to enhance the adaptivity of a team of autonomous robots. In this study, we show that a methodological approach based on artifcial neural networks shaped by evolutionary computation techniques can be successfully employed to synthesise the individual and social learning mechanisms for robots required to learn a desired action (i.e. phototaxis or antiphototaxis).

  8. A principled approach to bio-inspired design of legged locomotion systems

    NASA Astrophysics Data System (ADS)

    Koditschek, Daniel E.; Full, Robert J.; Buehler, Martin

    2004-09-01

    Casual daily observation provides convincing evidence that animals offer a wealth of inspiration for legged machines. However the lessons of animal motor science are largely written in the grammar of materials properties, and their meaning hidden by the complex interaction of multiply layered functional hierarchies. This paper will review some of the lessons of biological running that we have been able to articulate and begin to prescribe rigorously as manifest in the hexapod robot RHex. Although there is a long way to go before our mathematical analysis catches up with the full range of behaviors this remarkable machine exhibits, we are nevertheless able to make increasingly precise statements about certain control principles and the role they may play in RHex's performance. This ongoing research effort serves as a test case to underscore the huge and still largely untapped potential for mining bioinspiration in legged locomotion systems.

  9. Principle and Uncertainty Quantification of an Experiment Designed to Infer Actinide Neutron Capture Cross-Sections

    SciTech Connect

    G. Youinou; G. Palmiotti; M. Salvatorre; G. Imel; R. Pardo; F. Kondev; M. Paul

    2010-01-01

    An integral reactor physics experiment devoted to infer higher actinide (Am, Cm, Bk, Cf) neutron cross sections will take place in the US. This report presents the principle of the planned experiment as well as a first exercise aiming at quantifying the uncertainties related to the inferred quantities. It has been funded in part by the DOE Office of Science in the framework of the Recovery Act and has been given the name MANTRA for Measurement of Actinides Neutron TRAnsmutation. The principle is to irradiate different pure actinide samples in a test reactor like INL’s Advanced Test Reactor, and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after neutron irradiation allows the energy integrated neutron cross-sections to be inferred since the relation between the two are the well-known neutron-induced transmutation equations. This approach has been used in the past and the principal novelty of this experiment is that the atom densities of the different transmutation products will be determined with the Accelerator Mass Spectroscopy (AMS) facility located at ANL. While AMS facilities traditionally have been limited to the assay of low-to-medium atomic mass materials, i.e., A < 100, there has been recent progress in extending AMS to heavier isotopes – even to A > 200. The detection limit of AMS being orders of magnitude lower than that of standard mass spectroscopy techniques, more transmutation products could be measured and, potentially, more cross-sections could be inferred from the irradiation of a single sample. Furthermore, measurements will be carried out at the INL using more standard methods in order to have another set of totally uncorrelated information.

  10. Note: Design principles of a linear array multi-channel effusive metal-vapor atom source

    SciTech Connect

    Jana, B.; Majumder, A.; Thakur, K. B.; Das, A. K.

    2013-10-15

    Atomic beams can easily be produced by allowing atoms to effuse through a channel. In an earlier investigation [A. Majumder et al., Vacuum 83, 989 (2009)], we had designed, fabricated, and characterized an effusive metal-vapor source using collinear-array of multi-channel. In this note, we describe the theoretical basis of designing the source. Atom density in atomic beam has been estimated using a set of analytical expressions for long-channel operated in transparent mode. Parametric studies on aspect ratio of channel, inter-channel separation, beam width, and vertical distance from the source are carried out. They are useful in providing physical picture and optimizing design parameters.

  11. Principles of Design And Operations Of Wastewater Treatment Pond Systems For Plant Operators, Engineers, And Managers

    EPA Science Inventory

    Wastewater pond systems provide reliable, low cost, and relatively low maintenance treatment for municipal and industrial discharges. However, they do have certain design, operations, and maintenance requirements. While the basic models have not changed in the 30-odd years sinc...

  12. Combat Systems Vision 2030 Combat System Architecture: Design Principles and Methodology

    DTIC Science & Technology

    1991-12-01

    infrastructure to support it. Currently, industry activity in the area of information system development is high. In essence, corporations have automated their...lifecycle costs , etc., and distributes or allocates them to the subsystems of the functional architecture. At this point, the functional architecture... cost , etc., to the combat system elements. The third step in developing a feasibility design is that of tradeoff and optimization. The best design is

  13. Evolutionary Computing

    SciTech Connect

    Patton, Robert M; Cui, Xiaohui; Jiao, Yu; Potok, Thomas E

    2008-01-01

    The rate at which information overwhelms humans is significantly more than the rate at which humans have learned to process, analyze, and leverage this information. To overcome this challenge, new methods of computing must be formulated, and scientist and engineers have looked to nature for inspiration in developing these new methods. Consequently, evolutionary computing has emerged as new paradigm for computing, and has rapidly demonstrated its ability to solve real-world problems where traditional techniques have failed. This field of work has now become quite broad and encompasses areas ranging from artificial life to neural networks. This chapter focuses specifically on two sub-areas of nature-inspired computing: Evolutionary Algorithms and Swarm Intelligence.

  14. Applying evolutionary genetics to developmental toxicology and risk assessment.

    PubMed

    Leung, Maxwell C K; Procter, Andrew C; Goldstone, Jared V; Foox, Jonathan; DeSalle, Robert; Mattingly, Carolyn J; Siddall, Mark E; Timme-Laragy, Alicia R

    2017-03-04

    Evolutionary thinking continues to challenge our views on health and disease. Yet, there is a communication gap between evolutionary biologists and toxicologists in recognizing the connections among developmental pathways, high-throughput screening, and birth defects in humans. To increase our capability in identifying potential developmental toxicants in humans, we propose to apply evolutionary genetics to improve the experimental design and data interpretation with various in vitro and whole-organism models. We review five molecular systems of stress response and update 18 consensual cell-cell signaling pathways that are the hallmark for early development, organogenesis, and differentiation; and revisit the principles of teratology in light of recent advances in high-throughput screening, big data techniques, and systems toxicology. Multiscale systems modeling plays an integral role in the evolutionary approach to cross-species extrapolation. Phylogenetic analysis and comparative bioinformatics are both valuable tools in identifying and validating the molecular initiating events that account for adverse developmental outcomes in humans. The discordance of susceptibility between test species and humans (ontogeny) reflects their differences in evolutionary history (phylogeny). This synthesis not only can lead to novel applications in developmental toxicity and risk assessment, but also can pave the way for applying an evo-devo perspective to the study of developmental origins of health and disease.

  15. 'To preserve unity while almost allowing for chaos': Testing the aesthetic principle of unity-in-variety in product design.

    PubMed

    Post, R A G; Blijlevens, J; Hekkert, P

    2016-01-01

    Unity-in-variety is considered to be one of the oldest-known universal principles of beauty. However, little empirical research exists on how unity and variety together influence aesthetic appreciation. In three studies we investigated how unity and variety predict the aesthetic appreciation of a range of product designs, and further assessed whether perceived visual complexity and individual differences in regulatory focus influence this relationship. Our findings reveal that both unity and variety, while suppressing each other's effect, positively affect aesthetic appreciation. Hence, product designs that exhibit an optimum balance between unity and variety are aesthetically preferred. Furthermore, the research reveals that unity is the dominant factor in this relationship and facilitates the appreciation of variety. We discuss several theoretical and practical implications resulting from these studies.

  16. Allergen Immunotherapy Clinical Trial Outcomes and Design: Working Toward Harmonization of Methods and Principles.

    PubMed

    Nelson, Harold S; Calderon, Moises A; Bernstein, David I; Casale, Thomas B; Durham, Stephen R; Andersen, Jens S; Esch, Robert; Cox, Linda S; Nolte, Hendrik

    2017-03-01

    Progress has been made in the harmonization of efficacy and safety outcome measures for allergen immunotherapy (AIT) trials, but unresolved issues still remain. Furthermore, there are discrepancies in recommendations from professional medical societies and regulatory agencies regarding requirements for AIT trials. In this article, we reviewed published recommendations and current data from recent clinical trials, as well as the criteria applied by regulatory authorities for approval of AIT products, to provide updated considerations for conducting phase 3 AIT trials. Topics discussed include analysis of outcomes and trial designs for pediatric and asthma indications, as well as trial designs for perennial allergic rhinoconjunctivitis. In addition, the need for harmonization of safety reporting is emphasized. Considerations presented in this article may further effort to find common ground among professional medical societies and government agencies in developing future recommendations for AIT trial design.

  17. Human-Automation Integration: Principle and Method for Design and Evaluation

    NASA Technical Reports Server (NTRS)

    Billman, Dorrit; Feary, Michael

    2012-01-01

    Future space missions will increasingly depend on integration of complex engineered systems with their human operators. It is important to ensure that the systems that are designed and developed do a good job of supporting the needs of the work domain. Our research investigates methods for needs analysis. We included analysis of work products (plans for regulation of the space station) as well as work processes (tasks using current software), in a case study of Attitude Determination and Control Officers (ADCO) planning work. This allows comparing how well different designs match the structure of the work to be supported. Redesigned planning software that better matches the structure of work was developed and experimentally assessed. The new prototype enabled substantially faster and more accurate performance in plan revision tasks. This success suggests the approach to needs assessment and use in design and evaluation is promising, and merits investigatation in future research.

  18. Ergonomics principles to design clothing work for electrical workers in Colombia.

    PubMed

    Castillo, Juan; Cubillos, A

    2012-01-01

    The recent development of the Colombian legislation, have been identified the need to develop protective clothing to work according to specifications from the work done and in compliance with international standards. These involve the development and design of new strategies and measures for work clothing design. In this study we analyzes the activities of the workers in the electrical sector, the method analyzes the risks activity data in various activities, that activities include power generation plants, local facilities, industrial facilities and maintenance of urban and rural networks. The analyses method is focused on ergonomic approach, risk analysis is done, we evaluate the role of security expert and we use a design algorithm developed for this purpose. The result of this study is the identification of constraints and variables that contribute to the development of a model of analysis that leads to the development the work protective clothes.

  19. Developing Research Capabilities in Energy Biosciences: Design principles of photosynthetic biofuel production.

    SciTech Connect

    Donald D. Brown; David Savage

    2012-06-30

    The current fossil fuel-based energy infrastructure is not sustainable. Solar radiation is a plausible alternative, but realizing it as such will require significant technological advances in the ability to harvest light energy and convert it into suitable fuels. The biological system of photosynthesis can carry out these reactions, and in principle could be engineered using the tools of synthetic biology. One desirable implementation would be to rewire the reactions of a photosynthetic bacterium to direct the energy harvested from solar radiation into the synthesis of the biofuel H2. Proposed here is a series of experiments to lay the basic science groundwork for such an attempt. The goal is to elucidate the transcriptional network of photosynthesis using a novel driver-reporter screen, evolve more robust hydrogenases for improved catalysis, and to test the ability of the photosynthetic machinery to directly produce H2 in vivo. The results of these experiments will have broad implications for the understanding of photosynthesis, enzyme function, and the engineering of biological systems for sustainable energy production. The ultimate impact could be a fundamental transformation of the world's energy economy.

  20. Design of BAs-AlN monolayered honeycomb heterojunction structures: A first-principles study

    NASA Astrophysics Data System (ADS)

    Camacho-Mojica, Dulce C.; López-Urías, Florentino

    2016-04-01

    BAs and AlN are semiconductor materials with an indirect and direct gap respectively in the bulk phase. Recently, electronic calculations have demonstrated that a single-layer or few layers of BAs and AlN exhibit a graphite-like structure with interesting electronic properties. In this work, infinite sheets single-layer heterojunction structures based on alternated strips with honeycomb BAs and AlN layers are investigated using first-principles density functional theory calculations. Optimized geometries, density of states, band-gaps, formation energies, and wave functions are studied for different strip widths joined along zigzag and armchair edges. Results in optimized heterojunction geometries revealed that BAs narrow strips exhibit a corrugation effect due to a lattice mismatch. It was found that zigzag heterojunctions are more energetically favored than armchair heterojunctions. Furthermore, the formation energy presents a maximum at the point where the heterojunction becomes a planar structure. Electronic charge density results yielded a more ionic behavior in Alsbnd N bonds than the Bsbnd As bonds in accordance with monolayer results. It was observed that the conduction band minimum for both heterojunctions exhibit confined states located mainly at the entire AlN strips whereas the valence band maximum exhibits confined states located mainly at BAs strips. We expect that the present investigation will motivate more experimental and theoretical studies on new layered materials made of III-V semiconductors.