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Sample records for heuristic mastermind strategies

  1. Properties of heuristic search strategies

    NASA Technical Reports Server (NTRS)

    Vanderbrug, G. J.

    1973-01-01

    A directed graph is used to model the search space of a state space representation with single input operators, an AND/OR is used for problem reduction representations, and a theorem proving graph is used for state space representations with multiple input operators. These three graph models and heuristic strategies for searching them are surveyed. The completeness, admissibility, and optimality properties of search strategies which use the evaluation function f = (1 - omega)g = omega(h) are presented and interpreted using a representation of the search process in the plane. The use of multiple output operators to imply dependent successors, and thus obtain a formalism which includes all three types of representations, is discussed.

  2. Heuristical Strategies on the Study Theme "The Unsaturated Hydrocarbons -- Alkenes"

    ERIC Educational Resources Information Center

    Naumescu, Adrienne Kozan; Pasca, Roxana-Diana

    2011-01-01

    The influence of heuristical strategies upon the level of two experimental classes is studied in this paper. The didactic experiment took place at secondary school in Cluj-Napoca, in 2008-2009 school year. The study theme "The Unsaturated Hydrocarbons--Alkenes" has been efficiently learned by using the most active methods: laboratory…

  3. Compensatory Reading among ESL Learners: A Reading Strategy Heuristic

    ERIC Educational Resources Information Center

    Ismail, Shaik Abdul Malik Mohamed; Petras, Yusof Ede; Mohamed, Abdul Rashid; Eng, Lin Siew

    2015-01-01

    This paper aims to gain an insight to the relationship of two different concepts about reading comprehension, namely, the linear model of comprehension and the interactive compensatory theory. Drawing on both the above concepts, a heuristic was constructed about three different reading strategies determined by the specific ways the literal,…

  4. Analysis of complex network performance and heuristic node removal strategies

    NASA Astrophysics Data System (ADS)

    Jahanpour, Ehsan; Chen, Xin

    2013-12-01

    Removing important nodes from complex networks is a great challenge in fighting against criminal organizations and preventing disease outbreaks. Six network performance metrics, including four new metrics, are applied to quantify networks' diffusion speed, diffusion scale, homogeneity, and diameter. In order to efficiently identify nodes whose removal maximally destroys a network, i.e., minimizes network performance, ten structured heuristic node removal strategies are designed using different node centrality metrics including degree, betweenness, reciprocal closeness, complement-derived closeness, and eigenvector centrality. These strategies are applied to remove nodes from the September 11, 2001 hijackers' network, and their performance are compared to that of a random strategy, which removes randomly selected nodes, and the locally optimal solution (LOS), which removes nodes to minimize network performance at each step. The computational complexity of the 11 strategies and LOS is also analyzed. Results show that the node removal strategies using degree and betweenness centralities are more efficient than other strategies.

  5. Cracking Bank PINs by Playing Mastermind

    NASA Astrophysics Data System (ADS)

    Focardi, Riccardo; Luccio, Flaminia L.

    The bank director was pretty upset noticing Joe, the system administrator, spending his spare time playing Mastermind, an old useless game of the 70ies. He had fought the instinct of telling him how to better spend his life, just limiting to look at him in disgust long enough to be certain to be noticed. No wonder when the next day the director fell on his chair astonished while reading, on the newspaper, about a huge digital fraud on the ATMs of his bank, with millions of Euros stolen by a team of hackers all around the world. The article mentioned how the hackers had 'played with the bank computers just like playing Mastermind', being able to disclose thousands of user PINs during the one-hour lunch break. That precise moment, a second before falling senseless, he understood the subtle smile on Joe's face the day before, while training at his preferred game, Mastermind.

  6. Fieldwork Game Play: Masterminding Evidentiality in Desano

    ERIC Educational Resources Information Center

    Silva, Wilson; AnderBois, Scott

    2016-01-01

    In this paper, we propose a methodology for collecting naturally occurring data on evidentials and epistemic modals. We use Desano (Eastern Tukanoan) as a case study. This language has a complex evidential system with six evidential forms. The methodology in question consists of having Desano speakers to play a logic game, "Mastermind".…

  7. A philosophical evaluation of adaptationism as a heuristic strategy.

    PubMed

    Green, Sara

    2014-12-01

    Adaptationism has prompted many a debate in philosophy of biology but the focus is usually on empirical and explanatory issues rather than methodological adaptationism (MA). Likewise, the context of evolutionary biology has provided the grounding for most discussions of the heuristic role of adaptationism. This paper extends the debate by drawing on case studies from physiology and systems biology to discuss the productive and problematic aspects of adaptationism in functional as well as evolutionary studies at different levels of biological organization. Gould and Lewontin's Spandrels-paper famously criticized adaptationist methodology for implying a risk of generating 'blind spots' with respect to non-selective effects on evolution. Some have claimed that this bias can be accommodated through the testing of evolutionary hypotheses. Although this is an important aspect of overcoming the pitfalls of adaptationism, I argue that the issue of methodological biases is broader than the question of testability. I demonstrate the productivity of adaptationist heuristics but also discuss the deeper problematic aspects associated with the imperialistic tendencies of the strong account of MA. PMID:24992988

  8. The Development of a Culture of Problem Solving with Secondary Students through Heuristic Strategies

    ERIC Educational Resources Information Center

    Eisenmann, Petr; Novotná, Jarmila; Pribyl, Jirí; Brehovský, Jirí

    2015-01-01

    The article reports the results of a longitudinal research study conducted in three mathematics classes in Czech schools with 62 pupils aged 12-18 years. The pupils were exposed to the use of selected heuristic strategies in mathematical problem solving for a period of 16 months. This was done through solving problems where the solution was the…

  9. Superheroes and masterminds of plant domestication.

    PubMed

    Martínez-Ainsworth, Natalia E; Tenaillon, Maud I

    2016-01-01

    Domestication is one of the most fundamental changes in the evolution of human societies. The geographical origins of domesticated plants are inferred from archaeology, ecology and genetic data. Scenarios vary among species and include single, diffuse or multiple independent domestications. Cultivated plants present a panel of traits, the "domestication syndrome" that distinguish them from their wild relatives. It encompasses yield-, food usage-, and cultivation-related traits. Most genes underlying those traits are "masterminds" affecting the regulation of gene networks. Phenotypic convergence of domestication traits across species or within species between independently domesticated forms rarely coincides with convergence at the gene level. We review here current data/models that propose a protracted transition model for domestication and investigate the impact of mating system, life cycle and gene flow on the pace of domestication. Finally, we discuss the cost of domestication, pointing to the importance of characterizing adaptive functional variation in wild resources. PMID:27317057

  10. The development of a culture of problem solving with secondary students through heuristic strategies

    NASA Astrophysics Data System (ADS)

    Eisenmann, Petr; Novotná, Jarmila; Přibyl, Jiří; Břehovský, Jiří

    2015-12-01

    The article reports the results of a longitudinal research study conducted in three mathematics classes in Czech schools with 62 pupils aged 12-18 years. The pupils were exposed to the use of selected heuristic strategies in mathematical problem solving for a period of 16 months. This was done through solving problems where the solution was the most efficient if heuristic strategies were used. The authors conducted a two-dimensional classification of the use of heuristic strategies based on the work of Pólya (2004) and Schoenfeld (1985). We developed a tool that allows for the description of a pupil's ability to solve problems. Named, the Culture of Problem Solving (CPS), this tool consists of four components: intelligence, text comprehension, creativity and the ability to use existing knowledge. The pupils' success rate in problem solving and the changes in some of the CPS factors pre- and post-experiment were monitored. The pupils appeared to considerably improve in the creativity component. In addition, the results indicate a positive change in the students' attitude to problem solving. As far as the teachers participating in the experiment are concerned, a significant change was in their teaching style to a more constructivist, inquiry-based approach, as well as their willingness to accept a student's non-standard approach to solving a problem. Another important outcome of the research was the identification of the heuristic strategies that can be taught via long-term guided solutions of suitable problems and those that cannot. Those that can be taught include systematic experimentation, guess-check-revise and introduction of an auxiliary element. Those that cannot be taught (or can only be taught with difficulty) include the strategies of specification and generalization and analogy.

  11. Industrial waste recycling strategies optimization problem: mixed integer programming model and heuristics

    NASA Astrophysics Data System (ADS)

    Tang, Jiafu; Liu, Yang; Fung, Richard; Luo, Xinggang

    2008-12-01

    Manufacturers have a legal accountability to deal with industrial waste generated from their production processes in order to avoid pollution. Along with advances in waste recovery techniques, manufacturers may adopt various recycling strategies in dealing with industrial waste. With reuse strategies and technologies, byproducts or wastes will be returned to production processes in the iron and steel industry, and some waste can be recycled back to base material for reuse in other industries. This article focuses on a recovery strategies optimization problem for a typical class of industrial waste recycling process in order to maximize profit. There are multiple strategies for waste recycling available to generate multiple byproducts; these byproducts are then further transformed into several types of chemical products via different production patterns. A mixed integer programming model is developed to determine which recycling strategy and which production pattern should be selected with what quantity of chemical products corresponding to this strategy and pattern in order to yield maximum marginal profits. The sales profits of chemical products and the set-up costs of these strategies, patterns and operation costs of production are considered. A simulated annealing (SA) based heuristic algorithm is developed to solve the problem. Finally, an experiment is designed to verify the effectiveness and feasibility of the proposed method. By comparing a single strategy to multiple strategies in an example, it is shown that the total sales profit of chemical products can be increased by around 25% through the simultaneous use of multiple strategies. This illustrates the superiority of combinatorial multiple strategies. Furthermore, the effects of the model parameters on profit are discussed to help manufacturers organize their waste recycling network.

  12. Heuristic Chemistry--A Qualitative Study on Teaching Domain-Specific Strategies for the Six-Electron Case

    ERIC Educational Resources Information Center

    Graulich, Nicole; Tiemann, Rudiger; Schreiner, Peter R.

    2012-01-01

    We investigate the efficiency of domain-specific heuristic strategies in mastering and predicting pericyclic six-electron rearrangements. Based on recent research findings on these types of reactions a new concept has been developed that should help students identify and describe six-electron rearrangements more readily in complex molecules. The…

  13. On the asymptotic optimality and improved strategies of SPTB heuristic for open-shop scheduling problem

    NASA Astrophysics Data System (ADS)

    Bai, Danyu; Zhang, Zhihai

    2014-08-01

    This article investigates the open-shop scheduling problem with the optimal criterion of minimising the sum of quadratic completion times. For this NP-hard problem, the asymptotic optimality of the shortest processing time block (SPTB) heuristic is proven in the sense of limit. Moreover, three different improvements, namely, the job-insert scheme, tabu search and genetic algorithm, are introduced to enhance the quality of the original solution generated by the SPTB heuristic. At the end of the article, a series of numerical experiments demonstrate the convergence of the heuristic, the performance of the improvements and the effectiveness of the quadratic objective.

  14. Durga: A heuristically-optimized data collection strategy for volumetric magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Anand, Christopher Kumar; Curtis, Andrew Thomas; Kumar, Rakshit

    2008-02-01

    A heuristic design method for rapid volumetric magnetic resonance imaging data acquisition trajectories is presented, using a series of second-order cone optimization subproblems. Other researchers have considered non-raster data collection trajectories and under-sampled data patterns. This work demonstrates that much higher rates of under-sampling are possible with an asymmetric set of trajectories, with very little loss in resolution, but the addition of noise-like artefacts. The proposed data collection trajectory, Durga, further minimizes collection time by incorporating short un-refocused excitation pulses, resulting in above 98% collection efficiency for balanced steady state free precession imaging. The optimization subproblems are novel, in that they incorporate all requirements, including data collection (coverage), physicality (device limits), and signal generation (zeroth- and higher- moment properties) in a single convex problem, which allows the resulting trajectories to exhibit a higher collection efficiency than any existing trajectory design.

  15. Heuristic decision making in medicine

    PubMed Central

    Marewski, Julian N.; Gigerenzer, Gerd

    2012-01-01

    Can less information be more helpful when it comes to making medical decisions? Contrary to the common intuition that more information is always better, the use of heuristics can help both physicians and patients to make sound decisions. Heuristics are simple decision strategies that ignore part of the available information, basing decisions on only a few relevant predictors. We discuss: (i) how doctors and patients use heuristics; and (ii) when heuristics outperform information-greedy methods, such as regressions in medical diagnosis. Furthermore, we outline those features of heuristics that make them useful in health care settings. These features include their surprising accuracy, transparency, and wide accessibility, as well as the low costs and little time required to employ them. We close by explaining one of the statistical reasons why heuristics are accurate, and by pointing to psychiatry as one area for future research on heuristics in health care. PMID:22577307

  16. A Heuristic for Generating and Organizing the Strategy or Policy Report.

    ERIC Educational Resources Information Center

    Kelly, Kathleen; Weaver, Natalie Taylor

    1997-01-01

    Describes a model organization tree for the typical report expected of students in the strategy or policy course. Argues that, by defining relationships between the various analytical tasks and the overall strategy recommendation, the model helps students not only organize the final report but also understand the process by which they arrive at a…

  17. Heuristic status polling

    DOEpatents

    Archer, Charles J.; Blocksome, Michael A.; Heidelberger, Philip; Kumar, Sameer; Parker, Jeffrey J.; Ratterman, Joseph D.

    2011-06-07

    Methods, compute nodes, and computer program products are provided for heuristic status polling of a component in a computing system. Embodiments include receiving, by a polling module from a requesting application, a status request requesting status of a component; determining, by the polling module, whether an activity history for the component satisfies heuristic polling criteria; polling, by the polling module, the component for status if the activity history for the component satisfies the heuristic polling criteria; and not polling, by the polling module, the component for status if the activity history for the component does not satisfy the heuristic criteria.

  18. Search and heuristics

    SciTech Connect

    Pearl, J.

    1983-01-01

    This work is comprised of articles which are representative of current research on search and heuristics. The general theme is the quest for understanding the workings of heuristic knowledge; how it is acquired, stored and used by people, how it can be represented and utilized by machines and what makes one heuristic succeed where others fail. Topics covered include the following: search and reasoning in problem solving; theory formation by heuristic search; the nature of heuristics II: background and examples; Eurisko: a program that learns new heuristics and domain concepts; the nature of heuristics III: program design and results; searching for an optimal path in a tree with random costs; search rearrangement backtracking and polynomial average time; consistent-labeling problems and their algorithms: expected-complexities and theory-based heuristics; general branch and bound formulation for understanding and synthesizing and/or tree search procedures; a minimax algorithm better than alpha-beta. yes and no; and pathology on game trees revisited, and an alternative to minimaxing.

  19. Recursive heuristic classification

    NASA Technical Reports Server (NTRS)

    Wilkins, David C.

    1994-01-01

    The author will describe a new problem-solving approach called recursive heuristic classification, whereby a subproblem of heuristic classification is itself formulated and solved by heuristic classification. This allows the construction of more knowledge-intensive classification programs in a way that yields a clean organization. Further, standard knowledge acquisition and learning techniques for heuristic classification can be used to create, refine, and maintain the knowledge base associated with the recursively called classification expert system. The method of recursive heuristic classification was used in the Minerva blackboard shell for heuristic classification. Minerva recursively calls itself every problem-solving cycle to solve the important blackboard scheduler task, which involves assigning a desirability rating to alternative problem-solving actions. Knowing these ratings is critical to the use of an expert system as a component of a critiquing or apprenticeship tutoring system. One innovation of this research is a method called dynamic heuristic classification, which allows selection among dynamically generated classification categories instead of requiring them to be prenumerated.

  20. Testing Mars Exploration Rover-inspired operational strategies for semi-autonomous rovers on the moon II: The GeoHeuristic operational Strategies Test in Alaska

    NASA Astrophysics Data System (ADS)

    Yingst, R. A.; Cohen, B. A.; Hynek, B.; Schmidt, M. E.; Schrader, C.; Rodriguez, A.

    2014-06-01

    We used MER-derived semi-autonomous rover science operations strategies to determine best practices suitable for remote semi-autonomous lunar rover geology. Two field teams studied two glacial moraines as analogs for potential ice-bearing lunar regolith. At each site a Rover Team commanded a human rover to execute observations based on common MER sequences; the resulting data were used to identify and characterize targets of interest. A Tiger Team followed the Rover Team using traditional terrestrial field methods, and the results of the two teams were compared. Narrowly defined goals that can be addressed using cm-scale or coarser resolution may be met sufficiently by the operational strategies adapted from MER survey mode. When reconnaissance is the primary goal, the strategies tested are necessary but not sufficient. Further, there may be a set of optimal observations for such narrowly defined, hypothesis-driven science goals, such that collecting further data would result in diminishing returns. We confirm results of previous tests that indicated systematic observations might improve efficiency during strategic planning, and improve science output during data analysis. This strategy does not markedly improve the rate at which a science team can ingest data to feed back into tactical decision-making. Other methods should be tested to separate the strategic and tactical processes, and to build in time for data analysis.

  1. Pitfalls in Teaching Judgment Heuristics

    ERIC Educational Resources Information Center

    Shepperd, James A.; Koch, Erika J.

    2005-01-01

    Demonstrations of judgment heuristics typically focus on how heuristics can lead to poor judgments. However, exclusive focus on the negative consequences of heuristics can prove problematic. We illustrate the problem with the representativeness heuristic and present a study (N = 45) that examined how examples influence understanding of the…

  2. ALMA Pipeline Heuristics

    NASA Astrophysics Data System (ADS)

    Lightfoot, J.; Wyrowski, F.; Muders, D.; Boone, F.; Davis, L.; Shepherd, D.; Wilson, C.

    2006-07-01

    The ALMA (Atacama Large Millimeter Array) Pipeline Heuristics system is being developed to automatically reduce data taken with the standard observing modes. The goal is to make ALMA user-friendly to astronomers who are not experts in radio interferometry. The Pipeline Heuristics system must capture the expert knowledge required to provide data products that can be used without further processing. Observing modes to be processed by the system include single field interferometry, mosaics and single dish `on-the-fly' maps, and combinations of these modes. The data will be produced by the main ALMA array, the ALMA Compact Array (ACA) and single dish antennas. The Pipeline Heuristics system is being developed as a set of Python scripts. For interferometry these use as data processing engines the CASA/AIPS++ libraries and their bindings as CORBA objects within the ALMA Common Software (ACS). Initial development has used VLA and Plateau de Bure data sets to build and test a heuristic script capable of reducing single field data. In this paper we describe the reduction datapath and the algorithms used at each stage. Test results are presented. The path for future development is outlined.

  3. Heuristic Reasoning in Chemistry: Making decisions about acid strength

    NASA Astrophysics Data System (ADS)

    McClary, LaKeisha; Talanquer, Vicente

    2011-07-01

    The characterization of students' reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more analytical ways of thinking. The central goal of this qualitative study was thus to investigate heuristic reasoning as used by organic chemistry college students, focusing our attention on their ability to predict the relative acid strength of chemical compounds represented using explicit composition and structural features (i.e., structural formulas). Our results indicated that many study participants relied heavily on one or more of the following heuristics to make most of their decisions: reduction, representativeness, and lexicographic. Despite having visual access to reach structural information about the substances included in each ranking task, many students relied on isolated composition features to make their decisions. However, the specific characteristics of the tasks seemed to trigger heuristic reasoning in different ways. Although the use of heuristics allowed students to simplify some components of the ranking tasks and generate correct responses, it often led them astray. Very few study participants predicted the correct trends based on scientifically acceptable arguments. Our results suggest the need for instructional interventions that explicitly develop college chemistry students' abilities to monitor their thinking and evaluate the effectiveness of analytical versus heuristic reasoning strategies in different contexts.

  4. Heuristic Reasoning in Chemistry: Making Decisions about Acid Strength

    ERIC Educational Resources Information Center

    McClary, Lakeisha; Talanquer, Vicente

    2011-01-01

    The characterization of students' reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more…

  5. Obtaining Maxwell's equations heuristically

    NASA Astrophysics Data System (ADS)

    Diener, Gerhard; Weissbarth, Jürgen; Grossmann, Frank; Schmidt, Rüdiger

    2013-02-01

    Starting from the experimental fact that a moving charge experiences the Lorentz force and applying the fundamental principles of simplicity (first order derivatives only) and linearity (superposition principle), we show that the structure of the microscopic Maxwell equations for the electromagnetic fields can be deduced heuristically by using the transformation properties of the fields under space inversion and time reversal. Using the experimental facts of charge conservation and that electromagnetic waves propagate with the speed of light, together with Galilean invariance of the Lorentz force, allows us to finalize Maxwell's equations and to introduce arbitrary electrodynamics units naturally.

  6. The recognition heuristic: a review of theory and tests.

    PubMed

    Pachur, Thorsten; Todd, Peter M; Gigerenzer, Gerd; Schooler, Lael J; Goldstein, Daniel G

    2011-01-01

    The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a) that recognition is often an ecologically valid cue; (b) that people often follow recognition when making inferences; (c) that recognition supersedes further cue knowledge; (d) that its use can produce the less-is-more effect - the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference). PMID:21779266

  7. The Recognition Heuristic: A Review of Theory and Tests

    PubMed Central

    Pachur, Thorsten; Todd, Peter M.; Gigerenzer, Gerd; Schooler, Lael J.; Goldstein, Daniel G.

    2011-01-01

    The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a) that recognition is often an ecologically valid cue; (b) that people often follow recognition when making inferences; (c) that recognition supersedes further cue knowledge; (d) that its use can produce the less-is-more effect – the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference). PMID:21779266

  8. Reexamining Our Bias against Heuristics

    ERIC Educational Resources Information Center

    McLaughlin, Kevin; Eva, Kevin W.; Norman, Geoff R.

    2014-01-01

    Using heuristics offers several cognitive advantages, such as increased speed and reduced effort when making decisions, in addition to allowing us to make decision in situations where missing data do not allow for formal reasoning. But the traditional view of heuristics is that they trade accuracy for efficiency. Here the authors discuss sources…

  9. The nuclear protein encoded by the Drosophila neurogenic gene mastermind is widely expressed and associates with specific chromosomal regions

    SciTech Connect

    Bettler, D.; Pearson, S.; Yedvobnick, B.

    1996-06-01

    The Drosophila neurogenic loci encode a diverse group of proteins that comprise an inhibitory signal transduction pathway. The pathway is used throughout development in numerous contexts. We have examined the distribution of the neurogenic locus mastermind protein (Mam). Mam is expressed through all germlayers during early embryogenesis, including ectodermal precursors to both neuroblasts and epidermoblasts. Mam is subsequently down-regulated within the nervous system and then reexpressed. It persists in the nervous system through late embryogenesis and postembryonically. Mam is ubiquitously expressed in wing and leg imaginal discs and is not down-regulated in sensory organ precursor cells of the wing margin or notum. In the eye disc, Mam shows most prominent expression posterior to the morphogenetic furrow. Expression of the protein during oogenesis appears limited to follicle cells. Immunohistochemical detection of Mam on polytene chromosomes revealed binding at >100 sites. Chromosome colocalization studies with RNA polymerase and the groucho corepressor protein implicate Mam in transcriptional regulation. 94 refs., 8 figs., 1 tab.

  10. Hypoxia but not normoxia promotes Smoothened transcription through upregulation of RBPJ and Mastermind-like 3 in pancreatic cancer.

    PubMed

    Onishi, Hideya; Yamasaki, Akio; Kawamoto, Makoto; Imaizumi, Akira; Katano, Mitsuo

    2016-02-28

    We previously demonstrated that Hedgehog (Hh) signaling is activated under hypoxia through upregulation of transcription of Smoothened (SMO) gene. However, the mechanism of hypoxia-induced activation of SMO transcription remains unclear. In the analysis of altered expressions of genes related to Hh signaling between under normoxia and hypoxia by DNA microarray analysis, we picked up 2 genes, a transcriptional regulator, recombination signal binding protein for immunoglobulin-kappa-J region (RBPJ) and a transcriptional co-activator, Mastermind-like 3 (MAML3). Expressions of SMO, MAML3 and RBPJ were increased under hypoxia in pancreatic ductal adenocarcinoma cells (PDAC). RBPJ and MAML3 inhibition under hypoxia led to decreased SMO and GLI1 expressions, whereas SMO expression in MAML3-inhibited and RBPJ-inhibited cells under normoxia showed no change. However, overexpression of RBPJ under normoxia led to increased SMO expression. Additionally, cells knocked down for MAML3 and RBPJ inhibition under hypoxia showed decreased invasiveness through matrix metalloproteinase-2 suppression and decreased proliferation. Xenograft mouse models showed that MAML3 and RBPJ knockdown inhibited tumorigenicity and tumor volume. Our results suggest that hypoxia promotes SMO transcription through upregulation of MAML3 and RBPJ to induce proliferation, invasiveness and tumorigenesis in pancreatic cancer. PMID:26655998

  11. A parallel graph coloring heuristic

    SciTech Connect

    Jones, M.T.; Plassmann, P.E. )

    1993-05-01

    The problem of computing good graph colorings arises in many diverse applications, such as in the estimation of sparse Jacobians and in the development of efficient, parallel iterative methods for solving sparse linear systems. This paper presents an asynchronous graph coloring heuristic well suited to distributed memory parallel computers. Experimental results obtained on an Intel iPSC/860 are presented, which demonstrate that, for graphs arising from finite element applications, the heuristic exhibits scalable performance and generates colorings usually within three or four colors of the best-known linear time sequential heuristics. For bounded degree graphs, it is shown that the expected running time of the heuristic under the P-Ram computation model is bounded by EO(log(n)/log log(n)). This bound is an improvement over the previously known best upper bound for the expected running time of a random heuristic for the graph coloring problem.

  12. Heuristic-biased stochastic sampling

    SciTech Connect

    Bresina, J.L.

    1996-12-31

    This paper presents a search technique for scheduling problems, called Heuristic-Biased Stochastic Sampling (HBSS). The underlying assumption behind the HBSS approach is that strictly adhering to a search heuristic often does not yield the best solution and, therefore, exploration off the heuristic path can prove fruitful. Within the HBSS approach, the balance between heuristic adherence and exploration can be controlled according to the confidence one has in the heuristic. By varying this balance, encoded as a bias function, the HBSS approach encompasses a family of search algorithms of which greedy search and completely random search are extreme members. We present empirical results from an application of HBSS to the realworld problem of observation scheduling. These results show that with the proper bias function, it can be easy to outperform greedy search.

  13. New insights into diversification of hyper-heuristics.

    PubMed

    Ren, Zhilei; Jiang, He; Xuan, Jifeng; Hu, Yan; Luo, Zhongxuan

    2014-10-01

    There has been a growing research trend of applying hyper-heuristics for problem solving, due to their ability of balancing the intensification and the diversification with low level heuristics. Traditionally, the diversification mechanism is mostly realized by perturbing the incumbent solutions to escape from local optima. In this paper, we report our attempt toward providing a new diversification mechanism, which is based on the concept of instance perturbation. In contrast to existing approaches, the proposed mechanism achieves the diversification by perturbing the instance under solving, rather than the solutions. To tackle the challenge of incorporating instance perturbation into hyper-heuristics, we also design a new hyper-heuristic framework HIP-HOP (recursive acronym of HIP-HOP is an instance perturbation-based hyper-heuristic optimization procedure), which employs a grammar guided high level strategy to manipulate the low level heuristics. With the expressive power of the grammar, the constraints, such as the feasibility of the output solution could be easily satisfied. Numerical results and statistical tests over both the Ising spin glass problem and the p -median problem instances show that HIP-HOP is able to achieve promising performances. Furthermore, runtime distribution analysis reveals that, although being relatively slow at the beginning, HIP-HOP is able to achieve competitive solutions once given sufficient time. PMID:25222719

  14. Heuristic Learning and Programmed Learning

    ERIC Educational Resources Information Center

    Okon, Wincenty

    1969-01-01

    Flexibility in the application of instructional methods is the best approach to a teaching situation. Insofar as possible, a combination of traditional learning methods with heuristic (problem solving) and programed ones should be used. (CK)

  15. Heuristic dynamic complexity coding

    NASA Astrophysics Data System (ADS)

    Škorupa, Jozef; Slowack, Jürgen; Mys, Stefaan; Lambert, Peter; Van de Walle, Rik

    2008-04-01

    Distributed video coding is a new video coding paradigm that shifts the computational intensive motion estimation from encoder to decoder. This results in a lightweight encoder and a complex decoder, as opposed to the predictive video coding scheme (e.g., MPEG-X and H.26X) with a complex encoder and a lightweight decoder. Both schemas, however, do not have the ability to adapt to varying complexity constraints imposed by encoder and decoder, which is an essential ability for applications targeting a wide range of devices with different complexity constraints or applications with temporary variable complexity constraints. Moreover, the effect of complexity adaptation on the overall compression performance is of great importance and has not yet been investigated. To address this need, we have developed a video coding system with the possibility to adapt itself to complexity constraints by dynamically sharing the motion estimation computations between both components. On this system we have studied the effect of the complexity distribution on the compression performance. This paper describes how motion estimation can be shared using heuristic dynamic complexity and how distribution of complexity affects the overall compression performance of the system. The results show that the complexity can indeed be shared between encoder and decoder in an efficient way at acceptable rate-distortion performance.

  16. Memory-Based Decision-Making with Heuristics: Evidence for a Controlled Activation of Memory Representations

    ERIC Educational Resources Information Center

    Khader, Patrick H.; Pachur, Thorsten; Meier, Stefanie; Bien, Siegfried; Jost, Kerstin; Rosler, Frank

    2011-01-01

    Many of our daily decisions are memory based, that is, the attribute information about the decision alternatives has to be recalled. Behavioral studies suggest that for such decisions we often use simple strategies (heuristics) that rely on controlled and limited information search. It is assumed that these heuristics simplify decision-making by…

  17. A dynamic multiarmed bandit-gene expression programming hyper-heuristic for combinatorial optimization problems.

    PubMed

    Sabar, Nasser R; Ayob, Masri; Kendall, Graham; Qu, Rong

    2015-02-01

    Hyper-heuristics are search methodologies that aim to provide high-quality solutions across a wide variety of problem domains, rather than developing tailor-made methodologies for each problem instance/domain. A traditional hyper-heuristic framework has two levels, namely, the high level strategy (heuristic selection mechanism and the acceptance criterion) and low level heuristics (a set of problem specific heuristics). Due to the different landscape structures of different problem instances, the high level strategy plays an important role in the design of a hyper-heuristic framework. In this paper, we propose a new high level strategy for a hyper-heuristic framework. The proposed high-level strategy utilizes a dynamic multiarmed bandit-extreme value-based reward as an online heuristic selection mechanism to select the appropriate heuristic to be applied at each iteration. In addition, we propose a gene expression programming framework to automatically generate the acceptance criterion for each problem instance, instead of using human-designed criteria. Two well-known, and very different, combinatorial optimization problems, one static (exam timetabling) and one dynamic (dynamic vehicle routing) are used to demonstrate the generality of the proposed framework. Compared with state-of-the-art hyper-heuristics and other bespoke methods, empirical results demonstrate that the proposed framework is able to generalize well across both domains. We obtain competitive, if not better results, when compared to the best known results obtained from other methods that have been presented in the scientific literature. We also compare our approach against the recently released hyper-heuristic competition test suite. We again demonstrate the generality of our approach when we compare against other methods that have utilized the same six benchmark datasets from this test suite. PMID:24951713

  18. Heuristics for chemical compound matching.

    PubMed

    Hattori, Masahiro; Okuno, Yasushi; Goto, Susumu; Kanehisa, Minoru

    2003-01-01

    We have developed an efficient algorithm for comparing two chemical compounds, where the chemical structure is treated as a 2D graph consisting of atoms as vertices and covalent bonds as edges. Based on the concept of functional groups in chemistry, 68 atom types (vertex types) are defined for carbon, nitrogen, oxygen, and other atomic species with different environments, which has enabled detection of biochemically meaningful features. Maximal common subgraphs of two graphs can be found by searching for maximal cliques in the association graph, and we have introduced heuristics to accelerate the clique finding. Our heuristic procedure is controlled by some adjustable parameters. Here we applied our procedure to the latest KEGG/LIGAND database with different sets of parameters, and demonstrated the correlation of parameters in our algorithm with the distribution of similarity scores and/or the execution time. Finally, we showed the effectiveness of our heuristics for compound pairs along metabolic pathways. PMID:15706529

  19. Using Heuristic Evaluation to Foster Visualization Analysis and Design Skills.

    PubMed

    Sousa Santos, Beatriz; Quintino Ferreira, Beatriz; Dias, Paulo

    2016-01-01

    In an effort to develop visualization analysis and design skills in master's level information visualization students, the authors use a well-known analytical usability evaluation method, heuristic evaluation, with different sets of heuristics to teach students to analyze visualization applications. The proposed approach, used for three consecutive years, has successfully stimulated critical analysis and discussion sessions as well as helped raise students' awareness concerning the benefit of using systematic analysis methods and the strategies and guidelines that should be used to design visualization applications. PMID:26780763

  20. Regarding Chilcott's "Structural Functionalism as a Heuristic Device" Heuristically.

    ERIC Educational Resources Information Center

    Blot, Richard K.

    1998-01-01

    The heuristic value of Chilcott's essay lies less in its support for structural functionalism and more in its concern to reexamine theory in the work of earlier educational anthropologists for what earlier theories and practices can add to current research. (SLD)

  1. Rubrics: Heuristics for Developing Writing Strategies

    ERIC Educational Resources Information Center

    De La Paz, Susan

    2009-01-01

    Rubrics are an integral part of many writing programs, and they represent elements of good writing in essays, stories, poems, as well as other genres and forms of text. Although it is possible to use rubrics to teach students about the processes underlying effective writing, a more common practice is to use rubrics as a means of assessment, after…

  2. Social biases determine spatiotemporal sparseness of ciliate mating heuristics.

    PubMed

    Clark, Kevin B

    2012-01-01

    Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate's initial subjective bias, responsiveness, or preparedness, as defined by Stevens' Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present

  3. Application of heuristic optimization in aircraft design

    NASA Astrophysics Data System (ADS)

    Hu, Zhenning

    Genetic algorithms and the related heuristic optimization strategies are introduced and their applications in the aircraft design are developed. Generally speaking, genetic algorithms belong to non-deterministic direct search methods, which are most powerful in finding optimum or near-optimum solutions of a very complex system where a little priori knowledge is known. Therefore they have a wide application in aerospace systems. Two major aircraft optimal design projects are illustrated in this dissertation. The first is the application of material optimization of aligned fiber laminate composites in the presence of stress concentrations. After a large number of tests on laminates with different layers, genetic algorithms find an alignment pattern in a certain range for the Boeing Co. specified material. The second project is the application of piezoelectric actuator placement on a generic tail skins to reduce the 2nd mode vibration caused by buffet, which is part of a Boeing project to control the buffet effect on aircraft. In this project, genetic algorithms are closely involved with vibration analysis and finite element analysis. Actuator optimization strategies are first tested on the theoretical beam models to gain experience, and then the generic tail model is applied. Genetic algorithms achieve a great success in optimizing up to 888 actuator parameters on the tail skins.

  4. A Heuristic Approach to Scheduling University Timetables.

    ERIC Educational Resources Information Center

    Loo, E. H.; And Others

    1986-01-01

    Categories of facilities utilization and scheduling requirements to be considered when using a heuristic approach to timetabling are described together with a nine-step algorithm and the computerized timetabling system, Timetable Schedules System (TTS); TTS utilizes heuristic approach. An example demonstrating use of TTS and a program flowchart…

  5. Heuristics in an Educational System Design.

    ERIC Educational Resources Information Center

    Imbrogno, Salvatore

    Using a heuristic system design is the most cost effective means for confronting unstructured policy problems that require action in cases in which there is a limited empirical data base or a diversity of opinion concerning preferred ends and feasible means. This paper discusses heuristic principles that can serve as guides to problem solving and…

  6. "A Heuristic for Visual Thinking in History"

    ERIC Educational Resources Information Center

    Staley, David J.

    2007-01-01

    This article details a heuristic history teachers can use in assigning and evaluating multimedia projects in history. To use this heuristic successfully, requires more than simply following the steps in the list or stages in a recipe: in many ways, it requires a reorientation in what it means to think like an historian. This article, as much as…

  7. Minimizing conflicts: A heuristic repair method for constraint-satisfaction and scheduling problems

    NASA Technical Reports Server (NTRS)

    Minton, Steve; Johnston, Mark; Philips, Andrew; Laird, Phil

    1992-01-01

    This paper describes a simple heuristic approach to solving large-scale constraint satisfaction and scheduling problems. In this approach one starts with an inconsistent assignment for a set of variables and searches through the space of possible repairs. The search can be guided by a value-ordering heuristic, the min-conflicts heuristic, that attempts to minimize the number of constraint violations after each step. The heuristic can be used with a variety of different search strategies. We demonstrate empirically that on the n-queens problem, a technique based on this approach performs orders of magnitude better than traditional backtracking techniques. We also describe a scheduling application where the approach has been used successfully. A theoretical analysis is presented both to explain why this method works well on certain types of problems and to predict when it is likely to be most effective.

  8. The Role of Intuitive Heuristics in Students' Thinking: Ranking Chemical Substances

    ERIC Educational Resources Information Center

    Maeyer, Jenine; Talanquer, Vicente

    2010-01-01

    The characterization of students' cognitive biases is of central importance in the development of curriculum and teaching strategies that better support student learning in science. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to foster the…

  9. Automatic Generation of Heuristics for Scheduling

    NASA Technical Reports Server (NTRS)

    Morris, Robert A.; Bresina, John L.; Rodgers, Stuart M.

    1997-01-01

    This paper presents a technique, called GenH, that automatically generates search heuristics for scheduling problems. The impetus for developing this technique is the growing consensus that heuristics encode advice that is, at best, useful in solving most, or typical, problem instances, and, at worst, useful in solving only a narrowly defined set of instances. In either case, heuristic problem solvers, to be broadly applicable, should have a means of automatically adjusting to the idiosyncrasies of each problem instance. GenH generates a search heuristic for a given problem instance by hill-climbing in the space of possible multi-attribute heuristics, where the evaluation of a candidate heuristic is based on the quality of the solution found under its guidance. We present empirical results obtained by applying GenH to the real world problem of telescope observation scheduling. These results demonstrate that GenH is a simple and effective way of improving the performance of an heuristic scheduler.

  10. Heuristic Approach to the Schwarzschild Geometry

    NASA Astrophysics Data System (ADS)

    Visser, Matt

    In this article I present a simple Newtonian heuristic for motivating a weak-field approximation for the spacetime geometry of a point particle. The heuristic is based on Newtonian gravity, the notion of local inertial frames (the Einstein equivalence principle), plus the use of Galilean coordinate transformations to connect the freely falling local inertial frames back to the "fixed stars." Because of the heuristic and quasi-Newtonian manner in which the specific choice of spacetime geometry is motivated, we are at best justified in expecting it to be a weak-field approximation to the true spacetime geometry. However, in the case of a spherically symmetric point mass the result is coincidentally an exact solution of the full vacuum Einstein field equations — it is the Schwarzschild geometry in Painlevé-Gullstrand coordinates. This result is much stronger than the well-known result of Michell and Laplace whereby a Newtonian argument correctly estimates the value of the Schwarzschild radius — using the heuristic presented in this article one obtains the entire Schwarzschild geometry. The heuristic also gives sensible results — a Riemann flat geometry — when applied to a constant gravitational field. Furthermore, a subtle extension of the heuristic correctly reproduces the Reissner-Nordström geometry and even the de Sitter geometry. Unfortunately the heuristic construction is not truly generic. For instance, it is incapable of generating the Kerr geometry or anti-de Sitter space. Despite this limitation, the heuristic does have useful pedagogical value in that it provides a simple and direct plausibility argument (not a derivation) for the Schwarzschild geometry — suitable for classroom use in situations where the full power and technical machinery of general relativity might be inappropriate. The extended heuristic provides more challenging problems — suitable for use at the graduate level.

  11. Bidding Heuristics for Simultaneous Auctions: Lessons from TAC Travel

    NASA Astrophysics Data System (ADS)

    Greenwald, Amy; Naroditskiy, Victor; Lee, Seong Jae

    We undertake an experimental study of heuristics designed for the Travel division of the Trading Agent Competition. Our primary goal is to analyze the performance of the sample average approximation (SAA) heuristic, which is approximately optimal in the decision-theoretic (DT) setting, in this game-theoretic (GT) setting. To this end, we conduct experiments in four settings, three DT and one GT. The relevant distinction between the DT and the GT settings is: in the DT settings, agents' strategies do not affect the distribution of prices. Because of this distinction, the DT experiments are easier to analyze than the GT experiments. Moreover, settings with normally distributed prices, and controlled noise, are easier to analyze than those with competitive equilibrium prices. In the studied domain, analysis of the DT settings with possibly noisy normally distributed prices informs our analysis of the richer DT and GT settings with competitive equilibrium prices. In future work, we plan to investigate whether this experimental methodology - namely, transferring knowledge gained in a DT setting with noisy signals to a GT setting - can be applied to analyze heuristics for playing other complex games.

  12. Establishing usability heuristics for heuristics evaluation in a specific domain: Is there a consensus?

    PubMed

    Hermawati, Setia; Lawson, Glyn

    2016-09-01

    Heuristics evaluation is frequently employed to evaluate usability. While general heuristics are suitable to evaluate most user interfaces, there is still a need to establish heuristics for specific domains to ensure that their specific usability issues are identified. This paper presents a comprehensive review of 70 studies related to usability heuristics for specific domains. The aim of this paper is to review the processes that were applied to establish heuristics in specific domains and identify gaps in order to provide recommendations for future research and area of improvements. The most urgent issue found is the deficiency of validation effort following heuristics proposition and the lack of robustness and rigour of validation method adopted. Whether domain specific heuristics perform better or worse than general ones is inconclusive due to lack of validation quality and clarity on how to assess the effectiveness of heuristics for specific domains. The lack of validation quality also affects effort in improving existing heuristics for specific domain as their weaknesses are not addressed. PMID:27184309

  13. Parallel Heuristics for Scalable Community Detection

    SciTech Connect

    Lu, Howard; Kalyanaraman, Anantharaman; Halappanavar, Mahantesh; Choudhury, Sutanay

    2014-05-17

    Community detection has become a fundamental operation in numerous graph-theoretic applications. It is used to reveal natural divisions that exist within real world networks without imposing prior size or cardinality constraints on the set of communities. Despite its potential for application, there is only limited support for community detection on large-scale parallel computers, largely owing to the irregular and inherently sequential nature of the underlying heuristics. In this paper, we present parallelization heuristics for fast community detection using the Louvain method as the serial template. The Louvain method is an iterative heuristic for modularity optimization. Originally developed by Blondel et al. in 2008, the method has become increasingly popular owing to its ability to detect high modularity community partitions in a fast and memory-efficient manner. However, the method is also inherently sequential, thereby limiting its scalability to problems that can be solved on desktops. Here, we observe certain key properties of this method that present challenges for its parallelization, and consequently propose multiple heuristics that are designed to break the sequential barrier. Our heuristics are agnostic to the underlying parallel architecture. For evaluation purposes, we implemented our heuristics on shared memory (OpenMP) and distributed memory (MapReduce-MPI) machines, and tested them over real world graphs derived from multiple application domains (internet, biological, natural language processing). Experimental results demonstrate the ability of our heuristics to converge to high modularity solutions comparable to those output by the serial algorithm in nearly the same number of iterations, while also drastically reducing time to solution.

  14. Using tree diversity to compare phylogenetic heuristics

    PubMed Central

    Sul, Seung-Jin; Matthews, Suzanne; Williams, Tiffani L

    2009-01-01

    Background Evolutionary trees are family trees that represent the relationships between a group of organisms. Phylogenetic heuristics are used to search stochastically for the best-scoring trees in tree space. Given that better tree scores are believed to be better approximations of the true phylogeny, traditional evaluation techniques have used tree scores to determine the heuristics that find the best scores in the fastest time. We develop new techniques to evaluate phylogenetic heuristics based on both tree scores and topologies to compare Pauprat and Rec-I-DCM3, two popular Maximum Parsimony search algorithms. Results Our results show that although Pauprat and Rec-I-DCM3 find the trees with the same best scores, topologically these trees are quite different. Furthermore, the Rec-I-DCM3 trees cluster distinctly from the Pauprat trees. In addition to our heatmap visualizations of using parsimony scores and the Robinson-Foulds distance to compare best-scoring trees found by the two heuristics, we also develop entropy-based methods to show the diversity of the trees found. Overall, Pauprat identifies more diverse trees than Rec-I-DCM3. Conclusion Overall, our work shows that there is value to comparing heuristics beyond the parsimony scores that they find. Pauprat is a slower heuristic than Rec-I-DCM3. However, our work shows that there is tremendous value in using Pauprat to reconstruct trees—especially since it finds identical scoring but topologically distinct trees. Hence, instead of discounting Pauprat, effort should go in improving its implementation. Ultimately, improved performance measures lead to better phylogenetic heuristics and will result in better approximations of the true evolutionary history of the organisms of interest. PMID:19426451

  15. Prediction-based dynamic load-sharing heuristics

    NASA Technical Reports Server (NTRS)

    Goswami, Kumar K.; Devarakonda, Murthy; Iyer, Ravishankar K.

    1993-01-01

    The authors present dynamic load-sharing heuristics that use predicted resource requirements of processes to manage workloads in a distributed system. A previously developed statistical pattern-recognition method is employed for resource prediction. While nonprediction-based heuristics depend on a rapidly changing system status, the new heuristics depend on slowly changing program resource usage patterns. Furthermore, prediction-based heuristics can be more effective since they use future requirements rather than just the current system state. Four prediction-based heuristics, two centralized and two distributed, are presented. Using trace driven simulations, they are compared against random scheduling and two effective nonprediction based heuristics. Results show that the prediction-based centralized heuristics achieve up to 30 percent better response times than the nonprediction centralized heuristic, and that the prediction-based distributed heuristics achieve up to 50 percent improvements relative to their nonprediction counterpart.

  16. Heuristics as a Basis for Assessing Creative Potential: Measures, Methods, and Contingencies

    ERIC Educational Resources Information Center

    Vessey, William B.; Mumford, Michael D.

    2012-01-01

    Studies of creative thinking skills have generally measured a single aspect of creativity, divergent thinking. A number of other processes involved in creative thought have been identified. Effective execution of these processes is held to depend on the strategies applied in process execution, or heuristics. In this article, we review prior…

  17. Common-Sense Chemistry: The Use of Assumptions and Heuristics in Problem Solving

    ERIC Educational Resources Information Center

    Maeyer, Jenine Rachel

    2013-01-01

    Students experience difficulty learning and understanding chemistry at higher levels, often because of cognitive biases stemming from common sense reasoning constraints. These constraints can be divided into two categories: assumptions (beliefs held about the world around us) and heuristics (the reasoning strategies or rules used to build…

  18. Principals Reflecting on Their Leadership Learning with an Heuristic: A Pilot Study

    ERIC Educational Resources Information Center

    Dempster, Neil; Fluckiger, Bev; Lovett, Susan

    2012-01-01

    The purpose of this paper is to report on a small pilot study in which an heuristic was used to enable principals to reflect on the confidence they have in their existing leadership knowledge and how they might add to that knowledge in the future. The motivation for the study arose from a literature review of strategies for leadership development…

  19. The effects of Polya's heuristic and diary writing on children's problem solving

    NASA Astrophysics Data System (ADS)

    Hensberry, Karina K. R.; Jacobbe, Tim

    2012-03-01

    This paper presents the results of a study that aimed at increasing students' problem-solving skills. Polya's (1985) heuristic for problem solving was used and students were required to articulate their thought processes through the use of a structured diary. The diary prompted students to answer questions designed to engage them in the phases of Polya's (1985) heuristic. While it appeared as though most students did not internalise the diary questions, further analysis of students' responses indicated that most students showed improvement in their solution strategies. These results indicate that having students write about their thinking may be beneficial for developing their problem-solving skills.

  20. (Re)theorizing Integrated Knowledge Translation: A Heuristic for Knowledge-As-Action.

    PubMed

    Hartrick Doane, Gweneth; Reimer-Kirkham, Sheryl; Antifeau, Elisabeth; Stajduhar, Kelli

    2015-01-01

    Approaches to knowledge translation (KT) have undergone substantial transformation in an effort to find more effective strategies to ensure the best available knowledge informs nursing practice. However, the fundamental epistemology underpinning KT itself has gone largely unquestioned. Of particular concern is the inadequacy of current representational models to depict the complex, social process of KT. To address the limitations of representational models we propose an inquiry heuristic that conceptualizes KT as a knowledge-as-action process. Developed through a series of KT research projects, the heuristic is intended to guide the KT process and support effective navigation in the complexities of contemporary health care milieus. PMID:26244475

  1. Heuristics for scheduling Earth observing satellites

    NASA Astrophysics Data System (ADS)

    Wolfe, William J.; Sorensen, Stephen E.

    1999-09-01

    This paper describes several methods for assigning tasks to Earth Observing Systems Satellites (EOS). We present empirical results for three heuristics, called: Priority Dispatch (PD), Look Ahead (LA), and Genetic Algorithm (GA). These heuristics progress from simple to complex, from less accurate to more accurate, and from fast to slow. We present empirical results as applied to the Window-Constrained Packing problem (WCP). The WCP is a simplified version of the EOS scheduling problem. We discuss the problem of having more than one optimization criteria. We will also discuss the relationship between the WCP and the more traditional Knapsack and Weighted Early/Tardy problems.

  2. Draw: A Heuristic for Expressive Writing.

    ERIC Educational Resources Information Center

    Taylor, Michael

    1985-01-01

    Proposes a heuristic to generate specific and vivid phrasing and to draw on the right hemisphere of the brain for the substance of the essay. Describes stages of process as DRAW (Delineate, Ruminate, Analogize, and Write). Emphasizes creative description and expressive language rather than generation of ideas. (JG)

  3. Heuristic Classification. Technical Report Number 12.

    ERIC Educational Resources Information Center

    Clancey, William J.

    A broad range of well-structured problems--embracing forms of diagnosis, catalog selection, and skeletal planning--are solved in expert computer systems by the method of heuristic classification. These programs have a characteristic inference structure that systematically relates data to a pre-enumerated set of solutions by abstraction, heuristic…

  4. Investigating Heuristic Evaluation: A Case Study.

    ERIC Educational Resources Information Center

    Goldman, Kate Haley; Bendoly, Laura

    When museum professionals speak of evaluating a web site, they primarily mean formative evaluation, and by that they primarily mean testing the usability of the site. In the for-profit world, usability testing is a multi-million dollar industry, while non-profits often rely on far too few dollars to do too much. Hence, heuristic evaluation is one…

  5. Engineering applications of heuristic multilevel optimization methods

    NASA Technical Reports Server (NTRS)

    Barthelemy, Jean-Francois M.

    1989-01-01

    Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.

  6. Engineering applications of heuristic multilevel optimization methods

    NASA Technical Reports Server (NTRS)

    Barthelemy, Jean-Francois M.

    1988-01-01

    Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.

  7. Structural Functionalism as a Heuristic Device.

    ERIC Educational Resources Information Center

    Chilcott, John H.

    1998-01-01

    Argues that structural functionalism as a method for conducting fieldwork and as a format for the analysis of ethnographic data remains a powerful model, one that is easily understood by professional educators. As a heuristic device, functionalist theory can help in the solution of a problem that is otherwise incapable of theoretical…

  8. The Heuristic Interpretation of Box Plots

    ERIC Educational Resources Information Center

    Lem, Stephanie; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2013-01-01

    Box plots are frequently used, but are often misinterpreted by students. Especially the area of the box in box plots is often misinterpreted as representing number or proportion of observations, while it actually represents their density. In a first study, reaction time evidence was used to test whether heuristic reasoning underlies this…

  9. Heuristic Presentations: The Role of Structuring.

    ERIC Educational Resources Information Center

    Leron, Uri

    1985-01-01

    Discusses insufficiency of the linear method and some informal practices (or heuristics) used by expositors in trying to alleviate it. Uses the Cantor-Bernstein theorem to illustrate the linear proof, structuring, and the structure proof. Argues that the informal practices considered be consistently applied to the presentation of pivots and…

  10. A Variable-Selection Heuristic for K-Means Clustering.

    ERIC Educational Resources Information Center

    Brusco, Michael J.; Cradit, J. Dennis

    2001-01-01

    Presents a variable selection heuristic for nonhierarchical (K-means) cluster analysis based on the adjusted Rand index for measuring cluster recovery. Subjected the heuristic to Monte Carlo testing across more than 2,200 datasets. Results indicate that the heuristic is extremely effective at eliminating masking variables. (SLD)

  11. Heuristics Made Easy: An Effort-Reduction Framework

    ERIC Educational Resources Information Center

    Shah, Anuj K.; Oppenheimer, Daniel M.

    2008-01-01

    In this article, the authors propose a new framework for understanding and studying heuristics. The authors posit that heuristics primarily serve the purpose of reducing the effort associated with a task. As such, the authors propose that heuristics can be classified according to a small set of effort-reduction principles. The authors use this…

  12. Heuristic Diagrams as a Tool to Teach History of Science

    ERIC Educational Resources Information Center

    Chamizo, Jose A.

    2012-01-01

    The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The…

  13. Heuristic control of the Utah/MIT dextrous robot hand

    NASA Technical Reports Server (NTRS)

    Bass, Andrew H., Jr.

    1987-01-01

    Basic hand grips and sensor interactions that a dextrous robot hand will need as part of the operation of an EVA Retriever are analyzed. What is to be done with a dextrous robot hand is examined along with how such a complex machine might be controlled. It was assumed throughout that an anthropomorphic robot hand should perform tasks just as a human would; i.e., the most efficient approach to developing control strategies for the hand would be to model actual hand actions and do the same tasks in the same ways. Therefore, basic hand grips that human hands perform, as well as hand grip action were analyzed. It was also important to examine what is termed sensor fusion. This is the integration of various disparate sensor feedback paths. These feedback paths can be spatially and temporally separated, as well as, of different sensor types. Neural networks are seen as a means of integrating these varied sensor inputs and types. Basic heuristics of hand actions and grips were developed. These heuristics offer promise of control dextrous robot hands in a more natural and efficient way.

  14. Heuristic Evaluation of E-Learning Courses: A Comparative Analysis of Two E-Learning Heuristic Sets

    ERIC Educational Resources Information Center

    Zaharias, Panagiotis; Koutsabasis, Panayiotis

    2012-01-01

    Purpose: The purpose of this paper is to discuss heuristic evaluation as a method for evaluating e-learning courses and applications and more specifically to investigate the applicability and empirical use of two customized e-learning heuristic protocols. Design/methodology/approach: Two representative e-learning heuristic protocols were chosen…

  15. Learning process mapping heuristics under stochastic sampling overheads

    NASA Technical Reports Server (NTRS)

    Ieumwananonthachai, Arthur; Wah, Benjamin W.

    1991-01-01

    A statistical method was developed previously for improving process mapping heuristics. The method systematically explores the space of possible heuristics under a specified time constraint. Its goal is to get the best possible heuristics while trading between the solution quality of the process mapping heuristics and their execution time. The statistical selection method is extended to take into consideration the variations in the amount of time used to evaluate heuristics on a problem instance. The improvement in performance is presented using the more realistic assumption along with some methods that alleviate the additional complexity.

  16. On the heuristic nature of medical decision-support systems.

    PubMed

    Aliferis, C F; Miller, R A

    1995-03-01

    In the realm of medical decision-support systems, the term "heuristic systems" is often considered to be synonymous with "medical artificial intelligence systems" or with "systems employing informal model(s) of problem solving". Such a view may be inaccurate and possibly impede the conceptual development of future systems. This article examines the nature of heuristics and the levels at which heuristic solutions are introduced during system design and implementation. The authors discuss why heuristics are ubiquitous in all medical decision-support systems operating at non-trivial domains, and propose a unifying definition of heuristics that encompasses formal and ad hoc systems. System developers should be aware of the heuristic nature of all problem solving done in complex real world domains, and characterize their own use of heuristics in describing system development and implementation. PMID:9082138

  17. More than one way to see it: Individual heuristics in avian visual computation.

    PubMed

    Ravignani, Andrea; Westphal-Fitch, Gesche; Aust, Ulrike; Schlumpp, Martin M; Fitch, W Tecumseh

    2015-10-01

    Comparative pattern learning experiments investigate how different species find regularities in sensory input, providing insights into cognitive processing in humans and other animals. Past research has focused either on one species' ability to process pattern classes or different species' performance in recognizing the same pattern, with little attention to individual and species-specific heuristics and decision strategies. We trained and tested two bird species, pigeons (Columba livia) and kea (Nestor notabilis, a parrot species), on visual patterns using touch-screen technology. Patterns were composed of several abstract elements and had varying degrees of structural complexity. We developed a model selection paradigm, based on regular expressions, that allowed us to reconstruct the specific decision strategies and cognitive heuristics adopted by a given individual in our task. Individual birds showed considerable differences in the number, type and heterogeneity of heuristic strategies adopted. Birds' choices also exhibited consistent species-level differences. Kea adopted effective heuristic strategies, based on matching learned bigrams to stimulus edges. Individual pigeons, in contrast, adopted an idiosyncratic mix of strategies that included local transition probabilities and global string similarity. Although performance was above chance and quite high for kea, no individual of either species provided clear evidence of learning exactly the rule used to generate the training stimuli. Our results show that similar behavioral outcomes can be achieved using dramatically different strategies and highlight the dangers of combining multiple individuals in a group analysis. These findings, and our general approach, have implications for the design of future pattern learning experiments, and the interpretation of comparative cognition research more generally. PMID:26113444

  18. More than one way to see it: Individual heuristics in avian visual computation

    PubMed Central

    Ravignani, Andrea; Westphal-Fitch, Gesche; Aust, Ulrike; Schlumpp, Martin M.; Fitch, W. Tecumseh

    2015-01-01

    Comparative pattern learning experiments investigate how different species find regularities in sensory input, providing insights into cognitive processing in humans and other animals. Past research has focused either on one species’ ability to process pattern classes or different species’ performance in recognizing the same pattern, with little attention to individual and species-specific heuristics and decision strategies. We trained and tested two bird species, pigeons (Columba livia) and kea (Nestor notabilis, a parrot species), on visual patterns using touch-screen technology. Patterns were composed of several abstract elements and had varying degrees of structural complexity. We developed a model selection paradigm, based on regular expressions, that allowed us to reconstruct the specific decision strategies and cognitive heuristics adopted by a given individual in our task. Individual birds showed considerable differences in the number, type and heterogeneity of heuristic strategies adopted. Birds’ choices also exhibited consistent species-level differences. Kea adopted effective heuristic strategies, based on matching learned bigrams to stimulus edges. Individual pigeons, in contrast, adopted an idiosyncratic mix of strategies that included local transition probabilities and global string similarity. Although performance was above chance and quite high for kea, no individual of either species provided clear evidence of learning exactly the rule used to generate the training stimuli. Our results show that similar behavioral outcomes can be achieved using dramatically different strategies and highlight the dangers of combining multiple individuals in a group analysis. These findings, and our general approach, have implications for the design of future pattern learning experiments, and the interpretation of comparative cognition research more generally. PMID:26113444

  19. Computational Experiments with the RAVE Heuristic

    NASA Astrophysics Data System (ADS)

    Tom, David; Müller, Martin

    The Monte-Carlo tree search algorithm Upper Confidence bounds applied to Trees (UCT) has become extremely popular in computer games research. The Rapid Action Value Estimation (RAVE) heuristic is a strong estimator that often improves the performance of UCT-based algorithms. However, there are situations where RAVE misleads the search whereas pure UCT search can find the correct solution. Two games, the simple abstract game Sum of Switches (SOS) and the game of Go, are used to study the behavior of the RAVE heuristic. In SOS, RAVE updates are manipulated to mimic game situations where RAVE misleads the search. Such false RAVE updates are used to create RAVE overestimates and underestimates. A study of the distributions of mean and RAVE values reveals great differences between Go and SOS. While the RAVE-max update rule is able to correct extreme cases of RAVE underestimation, it is not effective in closer to practical settings and in Go.

  20. A System for Automatically Generating Scheduling Heuristics

    NASA Technical Reports Server (NTRS)

    Morris, Robert

    1996-01-01

    The goal of this research is to improve the performance of automated schedulers by designing and implementing an algorithm by automatically generating heuristics by selecting a schedule. The particular application selected by applying this method solves the problem of scheduling telescope observations, and is called the Associate Principal Astronomer. The input to the APA scheduler is a set of observation requests submitted by one or more astronomers. Each observation request specifies an observation program as well as scheduling constraints and preferences associated with the program. The scheduler employs greedy heuristic search to synthesize a schedule that satisfies all hard constraints of the domain and achieves a good score with respect to soft constraints expressed as an objective function established by an astronomer-user.

  1. Heuristics, LPs, and treeds on trees

    SciTech Connect

    Mirchandani, P.; Magnanti, T.L.; Balakrishnan, A.

    1994-12-31

    We discuss the worst-case behavior of heuristics and linear programming relaxations for a class of overlay optimization problems that combine linked subproblems by {open_quotes}overlaying{close_quotes} higher level subproblems on top of the solution of the lower level subproblems. Even though the subproblems (for example, shortest path, minimum spanning tree, etc.) might independently be polynomially solvable, the simplest special cases of the overlay optimization problems are NP-hard. Using bounds on the heuristics of the underlying subproblems, our analysis develops worst-case bounds of {open_quotes}composite{close_quotes} heuristics for several classes of the overlay optimization problem; we also develop bounds on the degree of suboptimality of the linear programming relaxation of the overlay optimization model. As a part of this development, we introduce a new class of multi-tier multi-connected network design problems; these models generalize several telecommunication survivability models in the literature. We also discuss how our general analysis of the overly optimization extends to these survivable network design problems.

  2. Heuristic Programming of Educational - Research Activity

    NASA Astrophysics Data System (ADS)

    Stoev, Alexey

    HEURISTIC PROGRAMMING OF EDUCATIONAL - RESEARCH ACTIVITY OF THE STUDENTS OF ASTRONOMY AT PUBLIC ASTRONOMICAL OBSERVATORIES A.Stoev Yu. Gagarin Public Astronomical Observatory Stara Zagora Bulgaria Seeking for optimal conditions of the students’ investigation skills development is exceptionally actual task in Astronomy school at Public astronomical observatory. The didactic plan of its solving is connected with a realization of the concept of the problematic approach in astronomical education. In addition different means of astronomical educative activity organization are used depending on the didactic task. In some cases they are algorithmic but in others - mainly heuristic. Educational - research skills are defined as skills of scientific method use in the conditions of seeking for educational problem solving the astronomical educational - research task. The influence of the system of heuristic programming didactic means on the process of teaching and the use of system of didactic means for out of the school education on astronomy aimed mainly to this activity rule are analyzed. In conclusion the process of optimization of the didactic conditions for students’ self-organization during the individual or collective completion of the educational - research astronomical tasks at the transition from secondary to high education.

  3. Common-sense chemistry: The use of assumptions and heuristics in problem solving

    NASA Astrophysics Data System (ADS)

    Maeyer, Jenine Rachel

    Students experience difficulty learning and understanding chemistry at higher levels, often because of cognitive biases stemming from common sense reasoning constraints. These constraints can be divided into two categories: assumptions (beliefs held about the world around us) and heuristics (the reasoning strategies or rules used to build predictions and make decisions). A better understanding and characterization of these constraints are of central importance in the development of curriculum and teaching strategies that better support student learning in science. It was the overall goal of this thesis to investigate student reasoning in chemistry, specifically to better understand and characterize the assumptions and heuristics used by undergraduate chemistry students. To achieve this, two mixed-methods studies were conducted, each with quantitative data collected using a questionnaire and qualitative data gathered through semi-structured interviews. The first project investigated the reasoning heuristics used when ranking chemical substances based on the relative value of a physical or chemical property, while the second study characterized the assumptions and heuristics used when making predictions about the relative likelihood of different types of chemical processes. Our results revealed that heuristics for cue selection and decision-making played a significant role in the construction of answers during the interviews. Many study participants relied frequently on one or more of the following heuristics to make their decisions: recognition, representativeness, one-reason decision-making, and arbitrary trend. These heuristics allowed students to generate answers in the absence of requisite knowledge, but often led students astray. When characterizing assumptions, our results indicate that students relied on intuitive, spurious, and valid assumptions about the nature of chemical substances and processes in building their responses. In particular, many

  4. Paging Doctor Google! Heuristics vs. technology

    PubMed Central

    Jhaveri, Kenar D

    2013-01-01

    The most dramatic development in medical decision-making technology has been the advent of the Internet. This has had an impact not only on clinicians, but has also become an important resource for patients who often approach their doctors with medical information they have obtained from the Internet.  Increasingly, medical students, residents and attending physicians have been using the Internet as a tool for diagnosing and treating disease. Internet-based resources that are available take various forms, including informational websites, online journals and textbooks, and social media.  Search engines such as Google have been increasingly used to help in making diagnoses of disease entities. Do these search methods fare better than experienced heuristic methods? In a small study, we examined the comparative role of heuristics versus the 'Google' mode of thinking. Internal medicine residents were asked to “google” key words to come up with a diagnosis. Their results were compared to experienced nephrology faculty and fellows in training using heuristics and no additional help of internet. Overall, with the aid of Google, the novices (internal medicine residents) correctly diagnosed renal diseases less often than the experts (the attendings) but with the same frequency as the intermediates (nephrology fellows).  However, in a subgroup analysis of both common diseases and rare diseases, the novices correctly diagnosed renal diseases less often than the experts but more often than the intermediates in each analysis.  The novices correctly diagnosed renal diseases with the same frequency as nephrology fellows in training. PMID:24627777

  5. Paging Doctor Google! Heuristics vs. technology.

    PubMed

    Jhaveri, Kenar D; Schrier, Peter B; Mattana, Joseph

    2013-01-01

    The most dramatic development in medical decision-making technology has been the advent of the Internet. This has had an impact not only on clinicians, but has also become an important resource for patients who often approach their doctors with medical information they have obtained from the Internet.  Increasingly, medical students, residents and attending physicians have been using the Internet as a tool for diagnosing and treating disease. Internet-based resources that are available take various forms, including informational websites, online journals and textbooks, and social media.  Search engines such as Google have been increasingly used to help in making diagnoses of disease entities. Do these search methods fare better than experienced heuristic methods? In a small study, we examined the comparative role of heuristics versus the 'Google' mode of thinking. Internal medicine residents were asked to "google" key words to come up with a diagnosis. Their results were compared to experienced nephrology faculty and fellows in training using heuristics and no additional help of internet. Overall, with the aid of Google, the novices (internal medicine residents) correctly diagnosed renal diseases less often than the experts (the attendings) but with the same frequency as the intermediates (nephrology fellows).  However, in a subgroup analysis of both common diseases and rare diseases, the novices correctly diagnosed renal diseases less often than the experts but more often than the intermediates in each analysis.  The novices correctly diagnosed renal diseases with the same frequency as nephrology fellows in training. PMID:24627777

  6. A general heuristic for genome rearrangement problems.

    PubMed

    Dias, Ulisses; Galvão, Gustavo Rodrigues; Lintzmayer, Carla Négri; Dias, Zanoni

    2014-06-01

    In this paper, we present a general heuristic for several problems in the genome rearrangement field. Our heuristic does not solve any problem directly, it is rather used to improve the solutions provided by any non-optimal algorithm that solve them. Therefore, we have implemented several algorithms described in the literature and several algorithms developed by ourselves. As a whole, we implemented 23 algorithms for 9 well known problems in the genome rearrangement field. A total of 13 algorithms were implemented for problems that use the notions of prefix and suffix operations. In addition, we worked on 5 algorithms for the classic problem of sorting by transposition and we conclude the experiments by presenting results for 3 approximation algorithms for the sorting by reversals and transpositions problem and 2 approximation algorithms for the sorting by reversals problem. Another algorithm with better approximation ratio can be found for the last genome rearrangement problem, but it is purely theoretical with no practical implementation. The algorithms we implemented in addition to our heuristic lead to the best practical results in each case. In particular, we were able to improve results on the sorting by transpositions problem, which is a very special case because many efforts have been made to generate algorithms with good results in practice and some of these algorithms provide results that equal the optimum solutions in many cases. Our source codes and benchmarks are freely available upon request from the authors so that it will be easier to compare new approaches against our results. PMID:24969750

  7. Intelligent process mapping through systematic improvement of heuristics

    NASA Technical Reports Server (NTRS)

    Ieumwananonthachai, Arthur; Aizawa, Akiko N.; Schwartz, Steven R.; Wah, Benjamin W.; Yan, Jerry C.

    1992-01-01

    The present system for automatic learning/evaluation of novel heuristic methods applicable to the mapping of communication-process sets on a computer network has its basis in the testing of a population of competing heuristic methods within a fixed time-constraint. The TEACHER 4.1 prototype learning system implemented or learning new postgame analysis heuristic methods iteratively generates and refines the mappings of a set of communicating processes on a computer network. A systematic exploration of the space of possible heuristic methods is shown to promise significant improvement.

  8. Heuristic determination of quantitative data for knowledge acquisition in medicine.

    PubMed

    Giuse, D A; Giuse, N B; Bankowitz, R A; Miller, R A

    1991-06-01

    Knowledge acquisition for medical knowledge bases can be aided by programs that suggest possible values for portions of the data. The paper presents an experiment which was used in designing a heuristic to help the process of knowledge acquisition. The heuristic helps to determine numerical data from stylized literature excerpts in the context of knowledge acquisition for the QMR medical knowledge base. Quantitative suggestions from the heuristics are shown to agree substantially with the data incorporated in the final version of the knowledge base. The experiment shows the potential of knowledge base specific heuristics in simplifying the task of knowledge base creation. PMID:1868695

  9. A Heuristic Approach for International Crude Oil Transportation Scheduling Problems

    NASA Astrophysics Data System (ADS)

    Yin, Sisi; Nishi, Tatsushi; Izuno, Tsukasa

    In this paper, we propose a heuristic algorithm to solve a practical ship scheduling problem for international crude oil transportation. The problem is considered as a vehicle routing problem with split deliveries. The objective of this paper is to find an optimal assignment of tankers, a sequence of visiting and loading volume simultaneously in order to minimize the total distance satisfying the capacity of tankers. A savings-based meta-heuristic algorithm with lot sizing parameters and volume assignment heuristic is developed. The proposed method is applied to solve a case study with real data. Computational results demonstrate the effectiveness of the heuristic algorithm compared with that of human operators.

  10. A Graph Search Heuristic for Shortest Distance Paths

    SciTech Connect

    Chow, E

    2005-03-24

    This paper presents a heuristic for guiding A* search for finding the shortest distance path between two vertices in a connected, undirected, and explicitly stored graph. The heuristic requires a small amount of data to be stored at each vertex. The heuristic has application to quickly detecting relationships between two vertices in a large information or knowledge network. We compare the performance of this heuristic with breadth-first search on graphs with various topological properties. The results show that one or more orders of magnitude improvement in the number of vertices expanded is possible for large graphs, including Poisson random graphs.

  11. Heuristic theory of positron-helium scattering.

    NASA Technical Reports Server (NTRS)

    Drachman, R. J.

    1971-01-01

    An error in a previous modified adiabatic approximation (Drachman, 1966), due to a lack of generality in the form of the short-range correlation part of the wave function for L greater than zero, is corrected heuristically by allowing the monopole suppression parameter to depend on L. An L-dependent local potential is constructed to fit the well-known positron-hydrogen s, p, and d wave phase shifts below the rearrangement threshold. The same form of potential yields a positron-helium cross-section in agreement with a recent experimental measurement near threshold.

  12. Hegemony, hermeneutics, and the heuristic of hope.

    PubMed

    Dorcy, Kathleen Shannon

    2010-01-01

    Hope has become a commodity, one that society expects those who suffer to invest in and one that healthcare providers are expected to promote as an outcome. In nursing research, a single hegemonic epistemology/ontology has been implemented through an exclusive hermeneutic (interpretation of data) and has resulted in hope being designated as an external objective heuristic for those who suffer. Evidence is articulated in this article for adopting a broader method of analysis and interpretation (genealogy) that can facilitate fuller apprehension of hope in the human experience of suffering and despair. PMID:20154528

  13. A heuristic method for reactive power planning

    SciTech Connect

    Mantovani, J.R.S.

    1996-02-01

    An approach for solving reactive power planning problems is presented, which is based on binary search techniques and the use of a special heuristic to obtain a discrete solution. Two versions were developed, one to run on conventional (sequential) computers and the other to run on a distributed memory (hypercube) machine. This latter parallel processing version employs an asynchronous programming model. Once the set of candidate bases has been defined, the program gives the location and size of the reactive sources needed (if any) in keeping with operating and security constraints.

  14. Risky Choice with Heuristics: Reply to Birnbaum (2008), Johnson, Schulte-Mecklenbeck, and Willemsen (2008), and Rieger and Wang (2008)

    ERIC Educational Resources Information Center

    Brandstatter, Eduard; Gigerenzer, Gerd; Hertwig, Ralph

    2008-01-01

    E. Brandstatter, G. Gigerenzer, and R. Hertwig (2006) showed that the priority heuristic matches or outperforms modifications of expected utility theory in predicting choice in 4 diverse problem sets. M. H. Birnbaum (2008) argued that sets exist in which the opposite is true. The authors agree--but stress that all choice strategies have regions of…

  15. University Research Centers: Heuristic Categories, Issues, and Administrative Strategies

    ERIC Educational Resources Information Center

    Hall, Kelly

    2011-01-01

    University-based research centers can bring prestige and revenue to the institutions of higher education with which they are affiliated. Collaborating with corporations, units of government, and foundations, centers provide services to organizational leaders, policy makers, and communities. University research centers continue to increase in…

  16. How do people judge risks: availability heuristic, affect heuristic, or both?

    PubMed

    Pachur, Thorsten; Hertwig, Ralph; Steinmann, Florian

    2012-09-01

    How does the public reckon which risks to be concerned about? The availability heuristic and the affect heuristic are key accounts of how laypeople judge risks. Yet, these two accounts have never been systematically tested against each other, nor have their predictive powers been examined across different measures of the public's risk perception. In two studies, we gauged risk perception in student samples by employing three measures (frequency, value of a statistical life, and perceived risk) and by using a homogeneous (cancer) and a classic set of heterogeneous causes of death. Based on these judgments of risk, we tested precise models of the availability heuristic and the affect heuristic and different definitions of availability and affect. Overall, availability-by-recall, a heuristic that exploits people's direct experience of occurrences of risks in their social network, conformed to people's responses best. We also found direct experience to carry a high degree of ecological validity (and one that clearly surpasses that of affective information). However, the relative impact of affective information (as compared to availability) proved more pronounced in value-of-a-statistical-life and perceived-risk judgments than in risk-frequency judgments. Encounters with risks in the media, in contrast, played a negligible role in people's judgments. Going beyond the assumption of exclusive reliance on either availability or affect, we also found evidence for mechanisms that combine both, either sequentially or in a composite fashion. We conclude with a discussion of policy implications of our results, including how to foster people's risk calibration and the success of education campaigns. PMID:22564084

  17. Memorability in Context: A Heuristic Story.

    PubMed

    Geurten, Marie; Meulemans, Thierry; Willems, Sylvie

    2015-01-01

    We examined children's ability to employ a metacognitive heuristic based on memorability expectations to reduce false recognitions, and explored whether these expectations depend on the context in which the items are presented. Specifically, 4-, 6-, and 9-year-old children were presented with high-, medium-, and low-memorability words, either mixed together (Experiment 1) or separated into two different lists (Experiment 2). Results revealed that only children with a higher level of executive functioning (9-year-olds) used the memorability-based heuristic when all types of items were presented within the same list. However, all children, regardless of age or executive level, implemented the metacognitive rule when high- and low-memorability words were presented in two separate lists. Moreover, the results of Experiment 2 showed that participants processed medium-memorability words more conservatively when they were presented in a low- than in a high-memorability list, suggesting that children's memorability expectations are sensitive to list-context effects. PMID:26592531

  18. Calibration of Biokinetic and Biological Parameters for a Groundwater Bioremediation Model using Heuristics and Function Approximation Optimization

    NASA Astrophysics Data System (ADS)

    Mugunthan, P.; Shoemaker, C. A.; Regis, R. G.

    2003-12-01

    Heuristics and function approximation optimization methods were applied in calibrating biological and biokinetic parameters for a computationally expensive groundwater bioremediation model for engineered reductive dechlorination of chlorinated ethenes. Multi-species groundwater bioremediation models that use monod type kinetics are often not amenable to traditional derivative based optimization due to stiff biokinetic equations. The performance of three heuristic methods, Stochastic Greedy Search (GS), Real Genetic Algorithm (RGA), Derandomized Evolution Strategy (DES), and, Function Approximation Optimization based on Radial Basis Function (FA-RBF) were compared on three-dimensional hypothetical and field problems. GS was implemented so as to perform a more global search. Optimization results on hypothetical problem indicated that FA-RBF performed statistically significantly better than heuristic based evolutionary algorithms at a 10% significance level. Further, this particular implementation of GS performed well and proved superior to RGA. These heuristic methods and FA-RBF, with the exception of RGA, were applied to calibrate biological and biokinetic parameters using treatability test data for enhanced bioremediation at a Naval Air Station in Alameda Point, CA. All three methods performed well and identified similar solutions. The approximate simulation times for the hypothetical and real problems were 7 min and 2.5 hours respectively. Calibration of such computationally expensive models by heuristic and function approximation methods appears promising.

  19. Instructional Design for Heuristic-Based Problem Solving.

    ERIC Educational Resources Information Center

    Ingram, Albert L.

    1988-01-01

    Discussion of instructional design models focuses on a study concerned with developing effective instruction in heuristic-based problem solving for computer programing. Highlights include distinctions between algorithms and heuristics; pretests and posttests; revised instructional design procedures; student attitudes; task analysis; and…

  20. On Dual Processing and Heuristic Approaches to Moral Cognition

    ERIC Educational Resources Information Center

    Lapsley, Daniel K.; Hill, Patrick L.

    2008-01-01

    We examine the implications of dual-processing theories of cognition for the moral domain, with particular emphasis upon "System 1" theories: the Social Intuitionist Model (Haidt), moral heuristics (Sunstein), fast-and-frugal moral heuristics (Gigerenzer), schema accessibility (Lapsley & Narvaez) and moral expertise (Narvaez). We argue that these…

  1. HEURISTIC OPTIMIZATION AND ALGORITHM TUNING APPLIED TO SORPTIVE BARRIER DESIGN

    EPA Science Inventory

    While heuristic optimization is applied in environmental applications, ad-hoc algorithm configuration is typical. We use a multi-layer sorptive barrier design problem as a benchmark for an algorithm-tuning procedure, as applied to three heuristics (genetic algorithms, simulated ...

  2. Heuristic Inquiry: A Personal Journey of Acculturation and Identity Reconstruction

    ERIC Educational Resources Information Center

    Djuraskovic, Ivana; Arthur, Nancy

    2010-01-01

    Heuristic methodology attempts to discover the nature and meaning of phenomenon through internal self-search, exploration, and discovery. Heuristic methodology encourages the researcher to explore and pursue the creative journey that begins inside one's being and ultimately uncovers its direction and meaning through internal discovery (Douglass &…

  3. Inferring heuristic classification hierarchies from natural language input

    NASA Technical Reports Server (NTRS)

    Hull, Richard; Gomez, Fernando

    1993-01-01

    A methodology for inferring hierarchies representing heuristic knowledge about the check out, control, and monitoring sub-system (CCMS) of the space shuttle launch processing system from natural language input is explained. Our method identifies failures explicitly and implicitly described in natural language by domain experts and uses those descriptions to recommend classifications for inclusion in the experts' heuristic hierarchies.

  4. Swift and Smart Decision Making: Heuristics that Work

    ERIC Educational Resources Information Center

    Hoy, Wayne K.; Tarter, C. J.

    2010-01-01

    Purpose: The aim of this paper is to examine the research literature on decision making and identify and develop a set of heuristics that work for school decision makers. Design/methodology/approach: This analysis is a synthesis of the research on decision-making heuristics that work. Findings: A set of nine rules for swift and smart decision…

  5. Cultural Heuristics: Topics of Invention Based on Human Behavior.

    ERIC Educational Resources Information Center

    DeGeorge, James M.

    Heuristic models help writers recall information, sometimes revealing unique combinations of information in ways not conceived previously. This makes heuristics a valuable technique for helping beginning writers generate writing ideas. Observing that all culture is communication, Edward Hall has organized Primary Message Systems (PMS), a framework…

  6. Experimental Matching of Instances to Heuristics for Constraint Satisfaction Problems.

    PubMed

    Moreno-Scott, Jorge Humberto; Ortiz-Bayliss, José Carlos; Terashima-Marín, Hugo; Conant-Pablos, Santiago Enrique

    2016-01-01

    Constraint satisfaction problems are of special interest for the artificial intelligence and operations research community due to their many applications. Although heuristics involved in solving these problems have largely been studied in the past, little is known about the relation between instances and the respective performance of the heuristics used to solve them. This paper focuses on both the exploration of the instance space to identify relations between instances and good performing heuristics and how to use such relations to improve the search. Firstly, the document describes a methodology to explore the instance space of constraint satisfaction problems and evaluate the corresponding performance of six variable ordering heuristics for such instances in order to find regions on the instance space where some heuristics outperform the others. Analyzing such regions favors the understanding of how these heuristics work and contribute to their improvement. Secondly, we use the information gathered from the first stage to predict the most suitable heuristic to use according to the features of the instance currently being solved. This approach proved to be competitive when compared against the heuristics applied in isolation on both randomly generated and structured instances of constraint satisfaction problems. PMID:26949383

  7. Experimental Matching of Instances to Heuristics for Constraint Satisfaction Problems

    PubMed Central

    Moreno-Scott, Jorge Humberto; Ortiz-Bayliss, José Carlos; Terashima-Marín, Hugo; Conant-Pablos, Santiago Enrique

    2016-01-01

    Constraint satisfaction problems are of special interest for the artificial intelligence and operations research community due to their many applications. Although heuristics involved in solving these problems have largely been studied in the past, little is known about the relation between instances and the respective performance of the heuristics used to solve them. This paper focuses on both the exploration of the instance space to identify relations between instances and good performing heuristics and how to use such relations to improve the search. Firstly, the document describes a methodology to explore the instance space of constraint satisfaction problems and evaluate the corresponding performance of six variable ordering heuristics for such instances in order to find regions on the instance space where some heuristics outperform the others. Analyzing such regions favors the understanding of how these heuristics work and contribute to their improvement. Secondly, we use the information gathered from the first stage to predict the most suitable heuristic to use according to the features of the instance currently being solved. This approach proved to be competitive when compared against the heuristics applied in isolation on both randomly generated and structured instances of constraint satisfaction problems. PMID:26949383

  8. Automating the packing heuristic design process with genetic programming.

    PubMed

    Burke, Edmund K; Hyde, Matthew R; Kendall, Graham; Woodward, John

    2012-01-01

    The literature shows that one-, two-, and three-dimensional bin packing and knapsack packing are difficult problems in operational research. Many techniques, including exact, heuristic, and metaheuristic approaches, have been investigated to solve these problems and it is often not clear which method to use when presented with a new instance. This paper presents an approach which is motivated by the goal of building computer systems which can design heuristic methods. The overall aim is to explore the possibilities for automating the heuristic design process. We present a genetic programming system to automatically generate a good quality heuristic for each instance. It is not necessary to change the methodology depending on the problem type (one-, two-, or three-dimensional knapsack and bin packing problems), and it therefore has a level of generality unmatched by other systems in the literature. We carry out an extensive suite of experiments and compare with the best human designed heuristics in the literature. Note that our heuristic design methodology uses the same parameters for all the experiments. The contribution of this paper is to present a more general packing methodology than those currently available, and to show that, by using this methodology, it is possible for a computer system to design heuristics which are competitive with the human designed heuristics from the literature. This represents the first packing algorithm in the literature able to claim human competitive results in such a wide variety of packing domains. PMID:21609273

  9. Heuristic Diagrams as a Tool to Teach History of Science

    NASA Astrophysics Data System (ADS)

    Chamizo, José A.

    2012-05-01

    The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The left side originally related in Gowin's Vee with philosophies, theories, models, laws or regularities now agrees with Toulmin's concepts (language, models as representation techniques and application procedures). Mexican science teachers without experience in science education research used the heuristic diagram to learn about the history of chemistry considering also in the left side two different historical times: past and present. Through a semantic differential scale teachers' attitude to the heuristic diagram was evaluated and its usefulness was demonstrated.

  10. An extended abstract: A heuristic repair method for constraint-satisfaction and scheduling problems

    NASA Technical Reports Server (NTRS)

    Minton, Steven; Johnston, Mark D.; Philips, Andrew B.; Laird, Philip

    1992-01-01

    The work described in this paper was inspired by a surprisingly effective neural network developed for scheduling astronomical observations on the Hubble Space Telescope. Our heuristic constraint satisfaction problem (CSP) method was distilled from an analysis of the network. In the process of carrying out the analysis, we discovered that the effectiveness of the network has little to do with its connectionist implementation. Furthermore, the ideas employed in the network can be implemented very efficiently within a symbolic CSP framework. The symbolic implementation is extremely simple. It also has the advantage that several different search strategies can be employed, although we have found that hill-climbing methods are particularly well-suited for the applications that we have investigated. We begin the paper with a brief review of the neural network. Following this, we describe our symbolic method for heuristic repair.

  11. Model-Free Dual Heuristic Dynamic Programming.

    PubMed

    Ni, Zhen; He, Haibo; Zhong, Xiangnan; Prokhorov, Danil V

    2015-08-01

    Model-based dual heuristic dynamic programming (MB-DHP) is a popular approach in approximating optimal solutions in control problems. Yet, it usually requires offline training for the model network, and thus resulting in extra computational cost. In this brief, we propose a model-free DHP (MF-DHP) design based on finite-difference technique. In particular, we adopt multilayer perceptron with one hidden layer for both the action and the critic networks design, and use delayed objective functions to train both the action and the critic networks online over time. We test both the MF-DHP and MB-DHP approaches with a discrete time example and a continuous time example under the same parameter settings. Our simulation results demonstrate that the MF-DHP approach can obtain a control performance competitive with that of the traditional MB-DHP approach while requiring less computational resources. PMID:25955997

  12. A Synthesized Heuristic Task Scheduling Algorithm

    PubMed Central

    Dai, Yanyan; Zhang, Xiangli

    2014-01-01

    Aiming at the static task scheduling problems in heterogeneous environment, a heuristic task scheduling algorithm named HCPPEFT is proposed. In task prioritizing phase, there are three levels of priority in the algorithm to choose task. First, the critical tasks have the highest priority, secondly the tasks with longer path to exit task will be selected, and then algorithm will choose tasks with less predecessors to schedule. In resource selection phase, the algorithm is selected task duplication to reduce the interresource communication cost, besides forecasting the impact of an assignment for all children of the current task permits better decisions to be made in selecting resources. The algorithm proposed is compared with STDH, PEFT, and HEFT algorithms through randomly generated graphs and sets of task graphs. The experimental results show that the new algorithm can achieve better scheduling performance. PMID:25254244

  13. Heuristic segmentation of a nonstationary time series

    NASA Astrophysics Data System (ADS)

    Fukuda, Kensuke; Eugene Stanley, H.; Nunes Amaral, Luís A.

    2004-02-01

    Many phenomena, both natural and human influenced, give rise to signals whose statistical properties change under time translation, i.e., are nonstationary. For some practical purposes, a nonstationary time series can be seen as a concatenation of stationary segments. However, the exact segmentation of a nonstationary time series is a hard computational problem which cannot be solved exactly by existing methods. For this reason, heuristic methods have been proposed. Using one such method, it has been reported that for several cases of interest—e.g., heart beat data and Internet traffic fluctuations—the distribution of durations of these stationary segments decays with a power-law tail. A potential technical difficulty that has not been thoroughly investigated is that a nonstationary time series with a (scalefree) power-law distribution of stationary segments is harder to segment than other nonstationary time series because of the wider range of possible segment lengths. Here, we investigate the validity of a heuristic segmentation algorithm recently proposed by Bernaola-Galván et al. [Phys. Rev. Lett. 87, 168105 (2001)] by systematically analyzing surrogate time series with different statistical properties. We find that if a given nonstationary time series has stationary periods whose length is distributed as a power law, the algorithm can split the time series into a set of stationary segments with the correct statistical properties. We also find that the estimated power-law exponent of the distribution of stationary-segment lengths is affected by (i) the minimum segment length and (ii) the ratio R≡σɛ/σx¯, where σx¯ is the standard deviation of the mean values of the segments and σɛ is the standard deviation of the fluctuations within a segment. Furthermore, we determine that the performance of the algorithm is generally not affected by uncorrelated noise spikes or by weak long-range temporal correlations of the fluctuations within segments.

  14. Interim Report on Heuristics about Inspection Parameters: Updates to Heuristics Resulting from Refinement on Projects

    NASA Technical Reports Server (NTRS)

    Shull, Forrest; Seaman, Carolyn; Feldman, Raimund; Haingaertner, Ralf; Regardie, Myrna

    2008-01-01

    In 2008, we have continued analyzing the inspection data in an effort to better understand the applicability and effect of the inspection heuristics on inspection outcomes. Our research goals during this period are: 1. Investigate the effect of anomalies in the dataset (e.g. the very large meeting length values for some inspections) on our results 2. Investigate the effect of the heuristics on other inspection outcome variables (e.g. effort) 3. Investigate whether the recommended ranges can be modified to give inspection planners more flexibility without sacrificing effectiveness 4. Investigate possible refinements or modifications to the heuristics for specific subdomains (partitioned, e.g., by size, domain, or Center) This memo reports our results to date towards addressing these goals. In the next section, the first goal is addressed by describing the types of anomalies we have found in our dataset, how we have addressed them, and the effect of these changes on our previously reported results. In the following section, on "methodology", we describe the analyses we have conducted to address the other three goals and the results of these analyses are described in the "results" section. Finally, we conclude with future plans for continuing our investigation.

  15. Innovative Meta-Heuristic Approach Application for Parameter Estimation of Probability Distribution Model

    NASA Astrophysics Data System (ADS)

    Lee, T. S.; Yoon, S.; Jeong, C.

    2012-12-01

    The primary purpose of frequency analysis in hydrology is to estimate the magnitude of an event with a given frequency of occurrence. The precision of frequency analysis depends on the selection of an appropriate probability distribution model (PDM) and parameter estimation techniques. A number of PDMs have been developed to describe the probability distribution of the hydrological variables. For each of the developed PDMs, estimated parameters are provided based on alternative estimation techniques, such as the method of moments (MOM), probability weighted moments (PWM), linear function of ranked observations (L-moments), and maximum likelihood (ML). Generally, the results using ML are more reliable than the other methods. However, the ML technique is more laborious than the other methods because an iterative numerical solution, such as the Newton-Raphson method, must be used for the parameter estimation of PDMs. In the meantime, meta-heuristic approaches have been developed to solve various engineering optimization problems (e.g., linear and stochastic, dynamic, nonlinear). These approaches include genetic algorithms, ant colony optimization, simulated annealing, tabu searches, and evolutionary computation methods. Meta-heuristic approaches use a stochastic random search instead of a gradient search so that intricate derivative information is unnecessary. Therefore, the meta-heuristic approaches have been shown to be a useful strategy to solve optimization problems in hydrology. A number of studies focus on using meta-heuristic approaches for estimation of hydrological variables with parameter estimation of PDMs. Applied meta-heuristic approaches offer reliable solutions but use more computation time than derivative-based methods. Therefore, the purpose of this study is to enhance the meta-heuristic approach for the parameter estimation of PDMs by using a recently developed algorithm known as a harmony search (HS). The performance of the HS is compared to the

  16. Teaching Evolution: A Heuristic Study of Personal and Cultural Dissonance

    NASA Astrophysics Data System (ADS)

    Grimes, Larry G.

    Darwinian evolution is a robustly supported scientific theory. Yet creationists continue to challenge its teaching in American public schools. Biology teachers in all 50 states are responsible for teaching science content standards that include evolution. As products of their backgrounds and affiliations teachers bring personal attitudes and beliefs to their teaching. The purpose of this study was to explore how biology teachers perceive, describe, and value their teaching of evolution. This research question was explored through a heuristic qualitative methodology. Eight veteran California high school biology teachers were queried as to their beliefs, perceptions, experiences and practices of teaching evolution. Both personal and professional documents were collected. Data was presented in the form of biographical essays that highlight teachers' backgrounds, experiences, perspectives and practices of teaching evolution. Of special interest was how they describe pressure over teaching evolution during a decade of standards and No Child Left Behind high-stakes testing mandates. Five common themes emerged. Standards have increased the overall amount of evolution that is taught. High-stakes testing has decreased the depth at which evolution is taught. Teacher belief systems strongly influence how evolution is taught. Fear of creationist challenges effect evolution teaching strategies. And lastly, concern over the potential effects of teaching evolution on student worldviews was mixed. Three categories of teacher concern over the potential impact of evolution on student worldviews were identified: Concerned, Strategist, and Carefree. In the final analysis teacher beliefs and attitudes still appeared to he the most important factor influencing how evolution is taught.

  17. A quantum heuristic algorithm for the traveling salesman problem

    NASA Astrophysics Data System (ADS)

    Bang, Jeongho; Ryu, Junghee; Lee, Changhyoup; Yoo, Seokwon; Lim, James; Lee, Jinhyoung

    2012-12-01

    We propose a quantum heuristic algorithm to solve the traveling salesman problem by generalizing the Grover search. Sufficient conditions are derived to greatly enhance the probability of finding the tours with the cheapest costs reaching almost to unity. These conditions are characterized by the statistical properties of tour costs and are shown to be automatically satisfied in the large-number limit of cities. In particular for a continuous distribution of the tours along the cost, we show that the quantum heuristic algorithm exhibits a quadratic speedup compared to its classical heuristic algorithm.

  18. Effective heuristics and meta-heuristics for the quadratic assignment problem with tuned parameters and analytical comparisons

    NASA Astrophysics Data System (ADS)

    Bashiri, Mahdi; Karimi, Hossein

    2012-07-01

    Quadratic assignment problem (QAP) is a well-known problem in the facility location and layout. It belongs to the NP-complete class. There are many heuristic and meta-heuristic methods, which are presented for QAP in the literature. In this paper, we applied 2-opt, greedy 2-opt, 3-opt, greedy 3-opt, and VNZ as heuristic methods and tabu search (TS), simulated annealing, and particle swarm optimization as meta-heuristic methods for the QAP. This research is dedicated to compare the relative percentage deviation of these solution qualities from the best known solution which is introduced in QAPLIB. Furthermore, a tuning method is applied for meta-heuristic parameters. Results indicate that TS is the best in 31%of QAPs, and the IFLS method, which is in the literature, is the best in 58 % of QAPs; these two methods are the same in 11 % of test problems. Also, TS has a better computational time among heuristic and meta-heuristic methods.

  19. Economic tour package model using heuristic

    NASA Astrophysics Data System (ADS)

    Rahman, Syariza Abdul; Benjamin, Aida Mauziah; Bakar, Engku Muhammad Nazri Engku Abu

    2014-07-01

    A tour-package is a prearranged tour that includes products and services such as food, activities, accommodation, and transportation, which are sold at a single price. Since the competitiveness within tourism industry is very high, many of the tour agents try to provide attractive tour-packages in order to meet tourist satisfaction as much as possible. Some of the criteria that are considered by the tourist are the number of places to be visited and the cost of the tour-packages. Previous studies indicate that tourists tend to choose economical tour-packages and aiming to visit as many places as they can cover. Thus, this study proposed tour-package model using heuristic approach. The aim is to find economical tour-packages and at the same time to propose as many places as possible to be visited by tourist in a given geographical area particularly in Langkawi Island. The proposed model considers only one starting point where the tour starts and ends at an identified hotel. This study covers 31 most attractive places in Langkawi Island from various categories of tourist attractions. Besides, the allocation of period for lunch and dinner are included in the proposed itineraries where it covers 11 popular restaurants around Langkawi Island. In developing the itinerary, the proposed heuristic approach considers time window for each site (hotel/restaurant/place) so that it represents real world implementation. We present three itineraries with different time constraints (1-day, 2-day and 3-day tour-package). The aim of economic model is to minimize the tour-package cost as much as possible by considering entrance fee of each visited place. We compare the proposed model with our uneconomic model from our previous study. The uneconomic model has no limitation to the cost with the aim to maximize the number of places to be visited. Comparison between the uneconomic and economic itinerary has shown that the proposed model have successfully achieved the objective that

  20. The Priority Heuristic: Making Choices Without Trade-Offs

    PubMed Central

    Brandstätter, Eduard; Gigerenzer, Gerd; Hertwig, Ralph

    2010-01-01

    Bernoulli's framework of expected utility serves as a model for various psychological processes, including motivation, moral sense, attitudes, and decision making. To account for evidence at variance with expected utility, we generalize the framework of fast and frugal heuristics from inferences to preferences. The priority heuristic predicts (i) Allais' paradox, (ii) risk aversion for gains if probabilities are high, (iii) risk seeking for gains if probabilities are low (lottery tickets), (iv) risk aversion for losses if probabilities are low (buying insurance), (v) risk seeking for losses if probabilities are high, (vi) certainty effect, (vii) possibility effect, and (viii) intransitivities. We test how accurately the heuristic predicts people's choices, compared to previously proposed heuristics and three modifications of expected utility theory: security-potential/aspiration theory, transfer-of-attention-exchange model, and cumulative prospect theory. PMID:16637767

  1. Plying Your Craft: Instructional Development and the Use of Heuristics.

    ERIC Educational Resources Information Center

    Noel, Kent L.; Hewlett, Brent

    1981-01-01

    Examines an instructional systems design (ISD) model used by Bell Laboratories as an illustration of how heuristics can be brought to bear upon the design and development of instructional materials. Ten references are listed. (Author/MER)

  2. The Ecosystem Approach: Perspectives, Heuristics and Interpretations

    NASA Astrophysics Data System (ADS)

    Kim, J.; Kang, M.; Malla Thakuri, B.; Yun, J.

    2012-12-01

    Based on the perspective of self-organization and complexity, we employed the ecosystem approach to translate the observed forest water and carbon dynamics into narratives. Multi-years' time series of the eddy covariance flux measurements from 2007 to 2010 are used to examine the ecohydrology in two adjacent deciduous and coniferous forest ecosystems in central Korea. Traditional descriptive analysis revealed contrasting interannual variability in net carbon uptake and evapotranspiration between the two forests, consistent with the interpretation on the basis of resilience framework. In a thermodynamic sense, net entropy production of the two forests was different in magnitude but their seasonal and interannual variability was consistent. The analysis of information entropy using the same data enabled to delineate the systems' state in terms of process network with an indication of self-organization through hierarchical aggregations of the subsystems. Finally, the ecosystem approach not only provided us with new perspectives, heuristics and interpretation, but also shed a light to prediction through parsimonious parameterization based on the maximum entropy production principle, for instance. (This study was supported by the Korea Meteorological Administration Research and Development Program under Grant CATER2012-3030. The flux data were provided by KoFlux and CarboEastAsia - A3 Foresight Program.)

  3. Scheduling constrained tools using heuristic techniques

    NASA Astrophysics Data System (ADS)

    Maram, Venkataramana; Rahman, Syariza Abdul; Maram, Sandhya Rani

    2015-12-01

    One of the main challenge to the current manufacturing production planning is to provide schedules of operations to maximize resource utilization to yield highest overall productivity. This is achieved by scheduling available resources to activities. There can be many different real time scenarios with different combination of input resources to produce parts. In this paper, the problem is simplified to single machine with individual process times and due dates to represent the real world scheduling problem. The main objective function is to minimize the total tardiness or late jobs. Nearest greedy method of assignment problem algorithm is used to find the initial solution followed by Simulated Annealing (SA) algorithm for the improvement part. Simulated Annealing is one of the meta-heuristic techniques in solving combinatorial optimization problem. The general purpose Microsoft Visual C++ is used to developed algorithm for finding the best solution. The proposed hybrid approach able to generate best schedule in 7th and optimal in 170th iteration with tardiness 8 and 7 hours respectively.

  4. Heuristic Modeling for TRMM Lifetime Predictions

    NASA Technical Reports Server (NTRS)

    Jordan, P. S.; Sharer, P. J.; DeFazio, R. L.

    1996-01-01

    Analysis time for computing the expected mission lifetimes of proposed frequently maneuvering, tightly altitude constrained, Earth orbiting spacecraft have been significantly reduced by means of a heuristic modeling method implemented in a commercial-off-the-shelf spreadsheet product (QuattroPro) running on a personal computer (PC). The method uses a look-up table to estimate the maneuver frequency per month as a function of the spacecraft ballistic coefficient and the solar flux index, then computes the associated fuel use by a simple engine model. Maneuver frequency data points are produced by means of a single 1-month run of traditional mission analysis software for each of the 12 to 25 data points required for the table. As the data point computations are required only a mission design start-up and on the occasion of significant mission redesigns, the dependence on time consuming traditional modeling methods is dramatically reduced. Results to date have agreed with traditional methods to within 1 to 1.5 percent. The spreadsheet approach is applicable to a wide variety of Earth orbiting spacecraft with tight altitude constraints. It will be particularly useful to such missions as the Tropical Rainfall Measurement Mission scheduled for launch in 1997, whose mission lifetime calculations are heavily dependent on frequently revised solar flux predictions.

  5. Critics and advisors: Heuristic knowledge and manufacturability

    SciTech Connect

    Rivera, J.J.; Stubblefield, W.A.; Ames, A.L.

    1996-06-01

    In recent years, much of the progress in Computer-Aided Manufacturing has emphasized the use of simulation, finite-element analysis, and other science-based techniques to plan and evaluate manufacturing processes. These approaches are all based on the idea that we can build sufficiently faithful models of complex manufacturing processes such as machining, welding, and casting. Although there has been considerable progress in this area, it continues to suffer from difficulties: the first of these is that the kind of highly accurate models that this approach requires may take many person months to construct, and the second is the large amount of computing resources needed to run these simulations. Two design advisors, Near Net-Shape Advisor and Design for Machinability Advisor, are being developed to explore the role of heuristic, knowledge-based systems for manufacturing processes, both as an alternative to more analytical techniques, and also in support of these techniques. Currently the advisors are both in the prototype stage. All indications lead to the conclusion that the advisors will be successful and lay the groundwork for additional systems such as these in the future.

  6. Heuristic Medicine: The Methodists and Metalepsis.

    PubMed

    Webster, Colin

    2015-09-01

    In the first century B.C.E., a group of Greek physicians called the Methodists denied that medicine could be based on such "hidden causes" as humors, atoms, or elements. They argued that the inner workings of the body were ultimately unknowable, existing beyond the limits of human knowledge and inference. Yet they insisted that medical certainty was still possible, claiming that every disease shared one of three directly apprehensible "manifest commonalities"--stricture, laxity, or some mixture of the two. Medicine could therefore be a science; it was simply noncausal in structure. This essay examines these medical theories in light of Herbert Simon's concept of "bounded rationality," suggesting that the Methodists were proposing a type of medical "heuristic" in response to the limitations of human knowledge and processing power. At the same time, the essay suggests that such an epistemology had its consequences, setting up an ontological crunch whereby the demands formerly placed on diseases and their causes transferred to "affections" and the commonalities, with successive generations of Methodists disagreeing about the status of symptoms, signs, and diseased states. Borrowing vocabulary from the Methodists themselves, the essay calls the consequent ontological slippage between causes and effects "metalepsis". PMID:26685524

  7. Climate adaptation heuristics and the science/policy divide

    SciTech Connect

    Preston, Benjamin L.; Mustelin, Johanna; Maloney, Megan C.

    2013-09-05

    The adaptation science enterprise has expanded rapidly in recent years, presumably in response to growth in demand for knowledge that can facilitate adaptation policy and practice. However, evidence suggests such investments in adaptation science have not necessarily translated into adaptation implementation. One potential constraint on adaptation may be the underlying heuristics that are used as the foundation for both adaptation research and practice. In this paper, we explore the adaptation academic literature with the objective of identifying adaptation heuristics, assessing the extent to which they have become entrenched within the adaptation discourse, and discussing potential weaknesses in their framing that could undermine adaptation efforts. This investigation is supported by a multi-method analysis that includes both a quantitative content analysis of the adaptation literature that evidences the use of adaptation heuristics and a qualitative analysis of the implications of such heuristics for enhancing or hindering the implementation of adaptation. Results demonstrate that a number of heuristic devices are commonly used in both the peer-reviewed adaptation literature as well as within grey literature designed to inform adaptation practitioners. Furthermore, the apparent lack of critical reflection upon the robustness of these heuristics for diverse contexts may contribute to potential cognitive bias with respect to the framing of adaptation by both researchers and practitioners. Finally, we discuss this phenomenon by drawing upon heuristic-analytic theory, which has explanatory utility in understanding both the origins of such heuristics as well as the measures that can be pursued toward the co-generation of more robust approaches to adaptation problem-solving.

  8. Climate adaptation heuristics and the science/policy divide

    DOE PAGESBeta

    Preston, Benjamin L.; Mustelin, Johanna; Maloney, Megan C.

    2013-09-05

    The adaptation science enterprise has expanded rapidly in recent years, presumably in response to growth in demand for knowledge that can facilitate adaptation policy and practice. However, evidence suggests such investments in adaptation science have not necessarily translated into adaptation implementation. One potential constraint on adaptation may be the underlying heuristics that are used as the foundation for both adaptation research and practice. In this paper, we explore the adaptation academic literature with the objective of identifying adaptation heuristics, assessing the extent to which they have become entrenched within the adaptation discourse, and discussing potential weaknesses in their framing thatmore » could undermine adaptation efforts. This investigation is supported by a multi-method analysis that includes both a quantitative content analysis of the adaptation literature that evidences the use of adaptation heuristics and a qualitative analysis of the implications of such heuristics for enhancing or hindering the implementation of adaptation. Results demonstrate that a number of heuristic devices are commonly used in both the peer-reviewed adaptation literature as well as within grey literature designed to inform adaptation practitioners. Furthermore, the apparent lack of critical reflection upon the robustness of these heuristics for diverse contexts may contribute to potential cognitive bias with respect to the framing of adaptation by both researchers and practitioners. Finally, we discuss this phenomenon by drawing upon heuristic-analytic theory, which has explanatory utility in understanding both the origins of such heuristics as well as the measures that can be pursued toward the co-generation of more robust approaches to adaptation problem-solving.« less

  9. Neural Basis of Scientific Innovation Induced by Heuristic Prototype

    PubMed Central

    Qiu, Jiang; Wei, Dongtao; Liu, Yijun; Zhang, Qinlin

    2013-01-01

    A number of major inventions in history have been based on bionic imitation. Heuristics, by applying biological systems to the creation of artificial devices and machines, might be one of the most critical processes in scientific innovation. In particular, prototype heuristics propositions that innovation may engage automatic activation of a prototype such as a biological system to form novel associations between a prototype's function and problem-solving. We speculated that the cortical dissociation between the automatic activation and forming novel associations in innovation is critical point to heuristic creativity. In the present study, novel and old scientific innovations (NSI and OSI) were selected as experimental materials in using learning-testing paradigm to explore the neural basis of scientific innovation induced by heuristic prototype. College students were required to resolve NSI problems (to which they did not know the answers) and OSI problems (to which they knew the answers). From two fMRI experiments, our results showed that the subjects could resolve NSI when provided with heuristic prototypes. In Experiment 1, it was found that the lingual gyrus (LG; BA18) might be related to prototype heuristics in college students resolving NSI after learning a relative prototype. In Experiment 2, the LG (BA18) and precuneus (BA31) were significantly activated for NSI compared to OSI when college students learned all prototypes one day before the test. In addition, the mean beta-values of these brain regions of NSI were all correlated with the behavior accuracy of NSI. As our hypothesis indicated, the findings suggested that the LG might be involved in forming novel associations using heuristic information, while the precuneus might be involved in the automatic activation of heuristic prototype during scientific innovation. PMID:23372641

  10. Automated discovery of local search heuristics for satisfiability testing.

    PubMed

    Fukunaga, Alex S

    2008-01-01

    The development of successful metaheuristic algorithms such as local search for a difficult problem such as satisfiability testing (SAT) is a challenging task. We investigate an evolutionary approach to automating the discovery of new local search heuristics for SAT. We show that several well-known SAT local search algorithms such as Walksat and Novelty are composite heuristics that are derived from novel combinations of a set of building blocks. Based on this observation, we developed CLASS, a genetic programming system that uses a simple composition operator to automatically discover SAT local search heuristics. New heuristics discovered by CLASS are shown to be competitive with the best Walksat variants, including Novelty+. Evolutionary algorithms have previously been applied to directly evolve a solution for a particular SAT instance. We show that the heuristics discovered by CLASS are also competitive with these previous, direct evolutionary approaches for SAT. We also analyze the local search behavior of the learned heuristics using the depth, mobility, and coverage metrics proposed by Schuurmans and Southey. PMID:18386995

  11. Generating effective project scheduling heuristics by abstraction and reconstitution

    NASA Technical Reports Server (NTRS)

    Janakiraman, Bhaskar; Prieditis, Armand

    1992-01-01

    A project scheduling problem consists of a finite set of jobs, each with fixed integer duration, requiring one or more resources such as personnel or equipment, and each subject to a set of precedence relations, which specify allowable job orderings, and a set of mutual exclusion relations, which specify jobs that cannot overlap. No job can be interrupted once started. The objective is to minimize project duration. This objective arises in nearly every large construction project--from software to hardware to buildings. Because such project scheduling problems are NP-hard, they are typically solved by branch-and-bound algorithms. In these algorithms, lower-bound duration estimates (admissible heuristics) are used to improve efficiency. One way to obtain an admissible heuristic is to remove (abstract) all resources and mutual exclusion constraints and then obtain the minimal project duration for the abstracted problem; this minimal duration is the admissible heuristic. Although such abstracted problems can be solved efficiently, they yield inaccurate admissible heuristics precisely because those constraints that are central to solving the original problem are abstracted. This paper describes a method to reconstitute the abstracted constraints back into the solution to the abstracted problem while maintaining efficiency, thereby generating better admissible heuristics. Our results suggest that reconstitution can make good admissible heuristics even better.

  12. Of mental models, assumptions and heuristics: The case of acids and acid strength

    NASA Astrophysics Data System (ADS)

    McClary, Lakeisha Michelle

    This study explored what cognitive resources (i.e., units of knowledge necessary to learn) first-semester organic chemistry students used to make decisions about acid strength and how those resources guided the prediction, explanation and justification of trends in acid strength. We were specifically interested in the identifying and characterizing the mental models, assumptions and heuristics that students relied upon to make their decisions, in most cases under time constraints. The views about acids and acid strength were investigated for twenty undergraduate students. Data sources for this study included written responses and individual interviews. The data was analyzed using a qualitative methodology to answer five research questions. Data analysis regarding these research questions was based on existing theoretical frameworks: problem representation (Chi, Feltovich & Glaser, 1981), mental models (Johnson-Laird, 1983); intuitive assumptions (Talanquer, 2006), and heuristics (Evans, 2008). These frameworks were combined to develop the framework from which our data were analyzed. Results indicated that first-semester organic chemistry students' use of cognitive resources was complex and dependent on their understanding of the behavior of acids. Expressed mental models were generated using prior knowledge and assumptions about acids and acid strength; these models were then employed to make decisions. Explicit and implicit features of the compounds in each task mediated participants' attention, which triggered the use of a very limited number of heuristics, or shortcut reasoning strategies. Many students, however, were able to apply more effortful analytic reasoning, though correct trends were predicted infrequently. Most students continued to use their mental models, assumptions and heuristics to explain a given trend in acid strength and to justify their predicted trends, but the tasks influenced a few students to shift from one model to another model. An

  13. Post-game analysis: An initial experiment for heuristic-based resource management in concurrent systems

    NASA Technical Reports Server (NTRS)

    Yan, Jerry C.

    1987-01-01

    In concurrent systems, a major responsibility of the resource management system is to decide how the application program is to be mapped onto the multi-processor. Instead of using abstract program and machine models, a generate-and-test framework known as 'post-game analysis' that is based on data gathered during program execution is proposed. Each iteration consists of (1) (a simulation of) an execution of the program; (2) analysis of the data gathered; and (3) the proposal of a new mapping that would have a smaller execution time. These heuristics are applied to predict execution time changes in response to small perturbations applied to the current mapping. An initial experiment was carried out using simple strategies on 'pipeline-like' applications. The results obtained from four simple strategies demonstrated that for this kind of application, even simple strategies can produce acceptable speed-up with a small number of iterations.

  14. Heuristic optimization of the scanning path of particle therapy beams

    SciTech Connect

    Pardo, J.; Donetti, M.; Bourhaleb, F.; Ansarinejad, A.; Attili, A.; Cirio, R.; Garella, M. A.; Giordanengo, S.; Givehchi, N.; La Rosa, A.; Marchetto, F.; Monaco, V.; Pecka, A.; Peroni, C.; Russo, G.; Sacchi, R.

    2009-06-15

    Quasidiscrete scanning is a delivery strategy for proton and ion beam therapy in which the beam is turned off when a slice is finished and a new energy must be set but not during the scanning between consecutive spots. Different scanning paths lead to different dose distributions due to the contribution of the unintended transit dose between spots. In this work an algorithm to optimize the scanning path for quasidiscrete scanned beams is presented. The classical simulated annealing algorithm is used. It is a heuristic algorithm frequently used in combinatorial optimization problems, which allows us to obtain nearly optimal solutions in acceptable running times. A study focused on the best choice of operational parameters on which the algorithm performance depends is presented. The convergence properties of the algorithm have been further improved by using the next-neighbor algorithm to generate the starting paths. Scanning paths for two clinical treatments have been optimized. The optimized paths are found to be shorter than the back-and-forth, top-to-bottom (zigzag) paths generally provided by the treatment planning systems. The gamma method has been applied to quantify the improvement achieved on the dose distribution. Results show a reduction of the transit dose when the optimized paths are used. The benefit is clear especially when the fluence per spot is low, as in the case of repainting. The minimization of the transit dose can potentially allow the use of higher beam intensities, thus decreasing the treatment time. The algorithm implemented for this work can optimize efficiently the scanning path of quasidiscrete scanned particle beams. Optimized scanning paths decrease the transit dose and lead to better dose distributions.

  15. Meta-heuristic algorithms as tools for hydrological science

    NASA Astrophysics Data System (ADS)

    Yoo, Do Guen; Kim, Joong Hoon

    2014-12-01

    In this paper, meta-heuristic optimization techniques are introduced and their applications to water resources engineering, particularly in hydrological science are introduced. In recent years, meta-heuristic optimization techniques have been introduced that can overcome the problems inherent in iterative simulations. These methods are able to find good solutions and require limited computation time and memory use without requiring complex derivatives. Simulation-based meta-heuristic methods such as Genetic algorithms (GAs) and Harmony Search (HS) have powerful searching abilities, which can occasionally overcome the several drawbacks of traditional mathematical methods. For example, HS algorithms can be conceptualized from a musical performance process and used to achieve better harmony; such optimization algorithms seek a near global optimum determined by the value of an objective function, providing a more robust determination of musical performance than can be achieved through typical aesthetic estimation. In this paper, meta-heuristic algorithms and their applications (focus on GAs and HS) in hydrological science are discussed by subject, including a review of existing literature in the field. Then, recent trends in optimization are presented and a relatively new technique such as Smallest Small World Cellular Harmony Search (SSWCHS) is briefly introduced, with a summary of promising results obtained in previous studies. As a result, previous studies have demonstrated that meta-heuristic algorithms are effective tools for the development of hydrological models and the management of water resources.

  16. Multicriteria meta-heuristics for AGV dispatching control based on computational intelligence.

    PubMed

    Naso, David; Turchiano, Biagio

    2005-04-01

    In many manufacturing environments, automated guided vehicles are used to move the processed materials between various pickup and delivery points. The assignment of vehicles to unit loads is a complex problem that is often solved in real-time with simple dispatching rules. This paper proposes an automated guided vehicles dispatching approach based on computational intelligence. We adopt a fuzzy multicriteria decision strategy to simultaneously take into account multiple aspects in every dispatching decision. Since the typical short-term view of dispatching rules is one of the main limitations of such real-time assignment heuristics, we also incorporate in the multicriteria algorithm a specific heuristic rule that takes into account the empty-vehicle travel on a longer time-horizon. Moreover, we also adopt a genetic algorithm to tune the weights associated to each decision criteria in the global decision algorithm. The proposed approach is validated by means of a comparison with other dispatching rules, and with other recently proposed multicriteria dispatching strategies also based on computational Intelligence. The analysis of the results obtained by the proposed dispatching approach in both nominal and perturbed operating conditions (congestions, faults) confirms its effectiveness. PMID:15828651

  17. Discovery and problem solving: Triangulation as a weak heuristic

    NASA Technical Reports Server (NTRS)

    Rochowiak, Daniel

    1987-01-01

    Recently the artificial intelligence community has turned its attention to the process of discovery and found that the history of science is a fertile source for what Darden has called compiled hindsight. Such hindsight generates weak heuristics for discovery that do not guarantee that discoveries will be made but do have proven worth in leading to discoveries. Triangulation is one such heuristic that is grounded in historical hindsight. This heuristic is explored within the general framework of the BACON, GLAUBER, STAHL, DALTON, and SUTTON programs. In triangulation different bases of information are compared in an effort to identify gaps between the bases. Thus, assuming that the bases of information are relevantly related, the gaps that are identified should be good locations for discovery and robust analysis.

  18. The min-conflicts heuristic: Experimental and theoretical results

    NASA Technical Reports Server (NTRS)

    Minton, Steven; Philips, Andrew B.; Johnston, Mark D.; Laird, Philip

    1991-01-01

    This paper describes a simple heuristic method for solving large-scale constraint satisfaction and scheduling problems. Given an initial assignment for the variables in a problem, the method operates by searching through the space of possible repairs. The search is guided by an ordering heuristic, the min-conflicts heuristic, that attempts to minimize the number of constraint violations after each step. We demonstrate empirically that the method performs orders of magnitude better than traditional backtracking techniques on certain standard problems. For example, the one million queens problem can be solved rapidly using our approach. We also describe practical scheduling applications where the method has been successfully applied. A theoretical analysis is presented to explain why the method works so well on certain types of problems and to predict when it is likely to be most effective.

  19. Applications of Meta-heuristics to Power and Energy Fields

    NASA Astrophysics Data System (ADS)

    Fukuyama, Yoshikazu

    Considering deregulation in power systems and the energy conservation law, power and energy systems require more cost and energy reduction for system planning, operation, and control. Optimization techniques such as linear and nonlinear programming techniques have been utilized as one of the methods for realization of the reduction. Recently, meta-heuristics such as genetic algorithm, simulated annealing, tabu search, and particle swarm optimization have been paid attention as other options for realization of the reduction. In power and energy society, we had one technical committee and one special issue on applications of meta-heuristics for power system. Moreover, panel sessions and tutorials have been held in IEEE and IFAC. This paper presents applications of meta-heuristics to power and energy fields from the practical application point of view.

  20. Plan-graph Based Heuristics for Conformant Probabilistic Planning

    NASA Technical Reports Server (NTRS)

    Ramakrishnan, Salesh; Pollack, Martha E.; Smith, David E.

    2004-01-01

    In this paper, we introduce plan-graph based heuristics to solve a variation of the conformant probabilistic planning (CPP) problem. In many real-world problems, it is the case that the sensors are unreliable or take too many resources to provide knowledge about the environment. These domains are better modeled as conformant planning problems. POMDP based techniques are currently the most successful approach for solving CPP but have the limitation of state- space explosion. Recent advances in deterministic and conformant planning have shown that plan-graphs can be used to enhance the performance significantly. We show that this enhancement can also be translated to CPP. We describe our process for developing the plan-graph heuristics and estimating the probability of a partial plan. We compare the performance of our planner PVHPOP when used with different heuristics. We also perform a comparison with a POMDP solver to show over a order of magnitude improvement in performance.

  1. A Comparison of Genetic Programming Variants for Hyper-Heuristics

    SciTech Connect

    Harris, Sean

    2015-03-01

    Modern society is faced with ever more complex problems, many of which can be formulated as generate-and-test optimization problems. General-purpose optimization algorithms are not well suited for real-world scenarios where many instances of the same problem class need to be repeatedly and efficiently solved, such as routing vehicles over highways with constantly changing traffic flows, because they are not targeted to a particular scenario. Hyper-heuristics automate the design of algorithms to create a custom algorithm for a particular scenario. Hyper-heuristics typically employ Genetic Programming (GP) and this project has investigated the relationship between the choice of GP and performance in Hyper-heuristics. Results are presented demonstrating the existence of problems for which there is a statistically significant performance differential between the use of different types of GP.

  2. The inherence heuristic as a source of essentialist thought.

    PubMed

    Salomon, Erika; Cimpian, Andrei

    2014-10-01

    Humans are essentialists: They believe hidden "essences" underlie membership in natural and social kinds. Although essentialism has well-established implications for important societal issues (e.g., discrimination), little is known about its origins. According to a recent proposal, essentialism emerges from a broader inherence heuristic-an intuitive tendency to explain patterns in terms of the inherent properties of their constituents (e.g., we have orange juice for breakfast [pattern] because citrus aromas [inherent feature] wake us up). We tested two predictions of this proposal-that reliance on the inherence heuristic predicts endorsement of essentialist beliefs, even when adjusting for potentially confounding variables (Studies 1 and 2), and that reducing reliance on the inherence heuristic produces a downstream reduction in essentialist thought (Studies 3 and 4). The results were consistent with these predictions and thus provided evidence for a new theoretical perspective on the cognitive underpinnings of psychological essentialism. PMID:25037751

  3. Reasoning by analogy as an aid to heuristic theorem proving.

    NASA Technical Reports Server (NTRS)

    Kling, R. E.

    1972-01-01

    When heuristic problem-solving programs are faced with large data bases that contain numbers of facts far in excess of those needed to solve any particular problem, their performance rapidly deteriorates. In this paper, the correspondence between a new unsolved problem and a previously solved analogous problem is computed and invoked to tailor large data bases to manageable sizes. This paper outlines the design of an algorithm for generating and exploiting analogies between theorems posed to a resolution-logic system. These algorithms are believed to be the first computationally feasible development of reasoning by analogy to be applied to heuristic theorem proving.

  4. Heuristic judgment of mass ratio in two-body collisions.

    PubMed

    Gilden, D L; Proffitt, D R

    1994-12-01

    The logic of judging relative mass from a two-body collision is developed from data presented by Runeson and Vedeler (1993). Data from two experiments are analyzed on a point-by-point basis, and strong support for the theory that mass-ratio judgments are mediated by separate speed and angle heuristics is shown. This analysis is accomplished by reducing the collision event to two elementary features: the presence of ricochet and the ratio of exit speeds. The heuristics that both ricochet and greater exit speed specify relative lightness are shown to explain the basic patterns of data presented by Runeson and Vedeler. PMID:7816541

  5. Automated unit-level testing with heuristic rules

    NASA Technical Reports Server (NTRS)

    Carlisle, W. Homer; Chang, Kai-Hsiung; Cross, James H.; Keleher, William; Shackelford, Keith

    1990-01-01

    Software testing plays a significant role in the development of complex software systems. Current testing methods generally require significant effort to generate meaningful test cases. The QUEST/Ada system is a prototype system designed using CLIPS to experiment with expert system based test case generation. The prototype is designed to test for condition coverage, and attempts to generate test cases to cover all feasible branches contained in an Ada program. This paper reports on heuristics sued by the system. These heuristics vary according to the amount of knowledge obtained by preprocessing and execution of the boolean conditions in the program.

  6. Philosophic Heuristic Instruction (PHI)--II.

    ERIC Educational Resources Information Center

    Coole, Walter A.

    This publication contains a course outline and syllabus, self-study units, and testing materials finished and tested in the Open Classroom, an auto-tutorial learning laboratory at Skagit Valley College (Washington). This self-contained course in informal logic is organized around problem-solving strategy and a collection of modules for extensive…

  7. Why distinctive information reduces false memories: evidence for both impoverished relational-encoding and distinctiveness heuristic accounts.

    PubMed

    Hege, Amanda C G; Dodson, Chad S

    2004-07-01

    Two accounts explain why studying pictures reduces false memories within the Deese-Roediger-McDermott paradigm (J. Deese, 1959; H. L. Roediger & K. B. McDermott, 1995). The impoverished relational-encoding account suggests that studying pictures interferes with the encoding of relational information, which is the primary basis for false memories in this paradigm. Alternatively, the distinctiveness heuristic assumes that critical lures are actively withheld by the use of a retrieval strategy. When participants were given inclusion recall instructions to report studied items as well as related items, they still reported critical lures less often after picture encoding than they did after word encoding. As the impoverished relational-encoding account suggests, critical lures appear less likely to come to mind after picture encoding than they do after word encoding. However, the results from a postrecall recognition test provide evidence in favor of the distinctiveness heuristic. PMID:15238023

  8. Chain Gang: A Framegame for Teaching Algorithms and Heuristics.

    ERIC Educational Resources Information Center

    Thiagarajan, Sivasailam; Pasigna, Aida L.

    1985-01-01

    Describes basic structure of a framegame, Chain Gang, in which self-instructional modules teach a cognitive skill. Procedures are presented for loading new content into the game's basic framework to teach algorithms or heuristics and for game modification to suit different situations. Handouts used in the basic game are appended. (MBR)

  9. Computer-Assisted Test Assembly Using Optimization Heuristics.

    ERIC Educational Resources Information Center

    Leucht, Richard M.

    1998-01-01

    Presents a variation of a "greedy" algorithm that can be used in test-assembly problems. The algorithm, the normalized weighted absolute-deviation heuristic, selects items to have a locally optimal fit to a moving set of average criterion values. Demonstrates application of the model. (SLD)

  10. A Heuristic Parsing Procedure for a Language Learning Program.

    ERIC Educational Resources Information Center

    Lindsay, Robert K.

    This paper reports a portion of a research effort to develop a program which will simulate the language learning behavior of humans. Here presented is a heuristic parsing procedure which accepts natural language sentences and produces for each a form of analysis called a "labeled dependency tree." The formal grammar on which the procedure is based…

  11. The Electrophysiological Correlates of Scientific Innovation Induced by Heuristic Information

    ERIC Educational Resources Information Center

    Luo, Junlong; Du, Xiumin; Tang, Xiaochen; Zhang, Entao; Li, Haijiang; Zhang, Qinglin

    2013-01-01

    In this study, novel and old scientific innovations (NSI and OSI) were selected as materials to explore the electrophysiological correlates of scientific innovation induced by heuristic information. Using event-related brain potentials (ERPs) to do so, college students solved NSI problems (for which they did not know the answers) and OSI problems…

  12. Heuristic Evaluation on Mobile Interfaces: A New Checklist

    PubMed Central

    Yáñez Gómez, Rosa; Cascado Caballero, Daniel; Sevillano, José-Luis

    2014-01-01

    The rapid evolution and adoption of mobile devices raise new usability challenges, given their limitations (in screen size, battery life, etc.) as well as the specific requirements of this new interaction. Traditional evaluation techniques need to be adapted in order for these requirements to be met. Heuristic evaluation (HE), an Inspection Method based on evaluation conducted by experts over a real system or prototype, is based on checklists which are desktop-centred and do not adequately detect mobile-specific usability issues. In this paper, we propose a compilation of heuristic evaluation checklists taken from the existing bibliography but readapted to new mobile interfaces. Selecting and rearranging these heuristic guidelines offer a tool which works well not just for evaluation but also as a best-practices checklist. The result is a comprehensive checklist which is experimentally evaluated as a design tool. This experimental evaluation involved two software engineers without any specific knowledge about usability, a group of ten users who compared the usability of a first prototype designed without our heuristics, and a second one after applying the proposed checklist. The results of this experiment show the usefulness of the proposed checklist for avoiding usability gaps even with nontrained developers. PMID:25295300

  13. Heuristic Techniques Application In A 3-D Space

    NASA Astrophysics Data System (ADS)

    Mazouz, A. Kader

    1989-02-01

    This paper discusses the application of a heuristic technique to stack regular and irregular shapes objects on the same container or on the same pallet. The computer representation of any object is based on the recursive octree method where each unit volume element is a voxel. Then, the choice of the space taken by any shape object within the volume is made through the heuristic approach. The heuristic technique developed is an evaluation function that compares all the available spaces based on weighing factors and threshold levels. The parameters used are shape, space available, contents of the object, and dimensions. The goal is to choose the most feasible available space every time an object is ready to be stacked. The heuristic algorithm is implemented within a knowledge based system to control a flexible material handling cell. Generally the cell comprises a material handling robot, a conveyance system that brings the objects to the cell where objects are distributed randomly to the cell, a vision system to identify the objects and verify the stacking procedure, and a computer to control and initiate the decision making process to stack all shape objects on the same volume.

  14. Divergence of Scientific Heuristic Method and Direct Algebraic Instruction

    ERIC Educational Resources Information Center

    Calucag, Lina S.

    2016-01-01

    This is an experimental study, made used of the non-randomized experimental and control groups, pretest-posttest designs. The experimental and control groups were two separate intact classes in Algebra. For a period of twelve sessions, the experimental group was subjected to the scientific heuristic method, but the control group instead was given…

  15. Resolution of seven-axis manipulator redundancy: A heuristic issue

    NASA Technical Reports Server (NTRS)

    Chen, I.

    1990-01-01

    An approach is presented for the resolution of the redundancy of a seven-axis manipulator arm from the AI and expert systems point of view. This approach is heuristic, analytical, and globally resolves the redundancy at the position level. When compared with other approaches, this approach has several improved performance capabilities, including singularity avoidance, repeatability, stability, and simplicity.

  16. Heuristics for multiextremal optimization on a hyperrectangle: Some experiments

    SciTech Connect

    Hendrix, E.; Roosma, J.

    1994-12-31

    The problem of finding the best point of a multiextremal oracle function on a hyperrectangle given a budget of (relatively expensive) function evaluations, is considered. Global optimization can be seen as combining covering actions and local searches. The combination can be adapted during the search depending on the roughness, number of optima found. Various heuristics are formulated and outcomes of experiments are shown.

  17. Implementing the Science Writing Heuristic in the Chemistry Laboratory

    ERIC Educational Resources Information Center

    Burke, K. A.; Greenbowe, Thomas J.; Hand, Brian M.

    2006-01-01

    The Science Writing Heuristic (SWH) is an instructional technique that combines inquiry, collaborative learning, and writing to change the nature of the chemistry laboratory for students and instructors. The SWH provides a format for students to guide their discussions, their thinking, and writing about how science activities relate to their own…

  18. How cognitive heuristics can explain social interactions in spatial movement.

    PubMed

    Seitz, Michael J; Bode, Nikolai W F; Köster, Gerta

    2016-08-01

    The movement of pedestrian crowds is a paradigmatic example of collective motion. The precise nature of individual-level behaviours underlying crowd movements has been subject to a lively debate. Here, we propose that pedestrians follow simple heuristics rooted in cognitive psychology, such as 'stop if another step would lead to a collision' or 'follow the person in front'. In other words, our paradigm explicitly models individual-level behaviour as a series of discrete decisions. We show that our cognitive heuristics produce realistic emergent crowd phenomena, such as lane formation and queuing behaviour. Based on our results, we suggest that pedestrians follow different cognitive heuristics that are selected depending on the context. This differs from the widely used approach of capturing changes in behaviour via model parameters and leads to testable hypotheses on changes in crowd behaviour for different motivation levels. For example, we expect that rushed individuals more often evade to the side and thus display distinct emergent queue formations in front of a bottleneck. Our heuristics can be ranked according to the cognitive effort that is required to follow them. Therefore, our model establishes a direct link between behavioural responses and cognitive effort and thus facilitates a novel perspective on collective behaviour. PMID:27581483

  19. Development of Heuristic Bias Detection in Elementary School

    ERIC Educational Resources Information Center

    De Neys, Wim; Feremans, Vicky

    2013-01-01

    Although human reasoning is often biased by intuitive heuristics, recent studies have shown that adults and adolescents detect the biased nature of their judgments. The present study focused on the development of this critical bias sensitivity by examining the detection skills of young children in elementary school. Third and 6th graders were…

  20. Ethical Reasoning: A Heuristic Approach for Business Educators.

    ERIC Educational Resources Information Center

    Molberg, Diane R.

    For the teaching of business report writing, ethical reasoning can be used as a heuristic for thinking that will encourage a more effective communication pattern for business students. Writing processes can be applied to thinking processes to help students approach theoretical concepts, make decisions, and write more effective business reports. A…

  1. Heuristics Applied in the Development of Advanced Space Mission Concepts

    NASA Technical Reports Server (NTRS)

    Nilsen, Erik N.

    1998-01-01

    Advanced mission studies are the first step in determining the feasibility of a given space exploration concept. A space scientist develops a science goal in the exploration of space. This may be a new observation method, a new instrument or a mission concept to explore a solar system body. In order to determine the feasibility of a deep space mission, a concept study is convened to determine the technology needs and estimated cost of performing that mission. Heuristics are one method of defining viable mission and systems architectures that can be assessed for technology readiness and cost. Developing a viable architecture depends to a large extent upon extending the existing body of knowledge, and applying it in new and novel ways. These heuristics have evolved over time to include methods for estimating technical complexity, technology development, cost modeling and mission risk in the unique context of deep space missions. This paper examines the processes involved in performing these advanced concepts studies, and analyzes the application of heuristics in the development of an advanced in-situ planetary mission. The Venus Surface Sample Return mission study provides a context for the examination of the heuristics applied in the development of the mission and systems architecture. This study is illustrative of the effort involved in the initial assessment of an advance mission concept, and the knowledge and tools that are applied.

  2. A Heuristic for Disassembly Planning in Remanufacturing System

    PubMed Central

    2014-01-01

    This study aims to improve the efficiency of disassembly planning in remanufacturing environment. Even though disassembly processes are considered as the reverse of the corresponding assembly processes, under some technological and management constraints the feasible and efficient disassembly planning can be achieved by only well-designed algorithms. In this paper, we propose a heuristic for disassembly planning with the existence of disassembled part/subassembly demands. A mathematical model is formulated for solving this problem to determine the sequence and quantity of disassembly operations to minimize the disassembly costs under sequence-dependent setup and capacity constraints. The disassembly costs consist of the setup cost, part inventory holding cost, disassembly processing cost, and purchasing cost that resulted from unsatisfied demand. A simple but efficient heuristic algorithm is proposed to improve the quality of solution and computational efficiency. The main idea of heuristic is to divide the planning horizon into the smaller planning windows and improve the computational efficiency without much loss of solution quality. Performances of the heuristic are investigated through the computational experiments. PMID:24895679

  3. A heuristic for disassembly planning in remanufacturing system.

    PubMed

    Sung, Jinmo; Jeong, Bongju

    2014-01-01

    This study aims to improve the efficiency of disassembly planning in remanufacturing environment. Even though disassembly processes are considered as the reverse of the corresponding assembly processes, under some technological and management constraints the feasible and efficient disassembly planning can be achieved by only well-designed algorithms. In this paper, we propose a heuristic for disassembly planning with the existence of disassembled part/subassembly demands. A mathematical model is formulated for solving this problem to determine the sequence and quantity of disassembly operations to minimize the disassembly costs under sequence-dependent setup and capacity constraints. The disassembly costs consist of the setup cost, part inventory holding cost, disassembly processing cost, and purchasing cost that resulted from unsatisfied demand. A simple but efficient heuristic algorithm is proposed to improve the quality of solution and computational efficiency. The main idea of heuristic is to divide the planning horizon into the smaller planning windows and improve the computational efficiency without much loss of solution quality. Performances of the heuristic are investigated through the computational experiments. PMID:24895679

  4. Making Predictions about Chemical Reactivity: Assumptions and Heuristics

    ERIC Educational Resources Information Center

    Maeyer, Jenine; Talanquer, Vicente

    2013-01-01

    Diverse implicit cognitive elements seem to support but also constrain reasoning in different domains. Many of these cognitive constraints can be thought of as either implicit assumptions about the nature of things or reasoning heuristics for decision-making. In this study we applied this framework to investigate college students'…

  5. The Priority Heuristic: Making Choices without Trade-Offs

    ERIC Educational Resources Information Center

    Brandstatter, Eduard; Gigerenzer, Gerd; Hertwig, Ralph

    2006-01-01

    Bernoulli's framework of expected utility serves as a model for various psychological processes, including motivation, moral sense, attitudes, and decision making. To account for evidence at variance with expected utility, the authors generalize the framework of fast and frugal heuristics from inferences to preferences. The priority heuristic…

  6. Heuristics guide cooperative behaviors in public goods game

    NASA Astrophysics Data System (ADS)

    Wang, Yongjie; Chen, Tong

    2015-12-01

    In public goods game (PGG), player's cooperative behavior is not pure economical rationality, but social preference and prosocial intuition play extremely important roles as well. Social preference and prosocial intuition can be guided by heuristics from one's neighbors in daily life. To better investigate the impacts of heuristics on the evolution of cooperation, four types of agents are introduced into our spatial PGG. Through numerical simulations, results show that the larger percentages of cooperators with independent thought, the easier emergence and maintenance of collective cooperative behaviors. Additionally, we find that differentia heuristic capability has great effect on the equilibrium of PGG. Cooperation can be obviously promoted, when heuristic capability of cooperators with independent thought is stronger than that of defectors with independent thought. Finally, we observe that cooperators with independent thought and defectors with independent thought are favorable for the formation of some high quality clusters, which can resist the invasion between each other. Our work may help us understand more clearly the mechanism of cooperation in real world.

  7. Prototypes Are Key Heuristic Information in Insight Problem Solving

    ERIC Educational Resources Information Center

    Yang, Wenjing; Dietrich, Arne; Liu, Peiduo; Ming, Dan; Jin, Yule; Nusbaum, Howard C.; Qiu, Jiang; Zhang, Qinglin

    2016-01-01

    Evidence from a range of fields indicates that inventions are often inspired by drawing a parallel to solutions found in nature. However, the cognitive mechanism of this process is not well understood. The cognitive mechanism of heuristic prototype in scientific innovation was tested with 3 experiments. First, 84 historical accounts of important…

  8. Algo-Heuristic Theory of Performance, Learning, and Instruction: Subject, Problems, Principles.

    ERIC Educational Resources Information Center

    Landa, Lev N.

    1984-01-01

    The algo-heuristic theory is concerned with identifying unobservable cognitive processes and their unconscious component cognitive operations, including learning how to describe them algorithmically and heuristically, and how to devise specific instructional tools (algorithmic and heuristic) to develop cognitive processes much faster. (BW)

  9. Automated Detection of Heuristics and Biases among Pathologists in a Computer-Based System

    ERIC Educational Resources Information Center

    Crowley, Rebecca S.; Legowski, Elizabeth; Medvedeva, Olga; Reitmeyer, Kayse; Tseytlin, Eugene; Castine, Melissa; Jukic, Drazen; Mello-Thoms, Claudia

    2013-01-01

    The purpose of this study is threefold: (1) to develop an automated, computer-based method to detect heuristics and biases as pathologists examine virtual slide cases, (2) to measure the frequency and distribution of heuristics and errors across three levels of training, and (3) to examine relationships of heuristics to biases, and biases to…

  10. Fluency Heuristic: A Model of How the Mind Exploits a By-Product of Information Retrieval

    ERIC Educational Resources Information Center

    Hertwig, Ralph; Herzog, Stefan M.; Schooler, Lael J.; Reimer, Torsten

    2008-01-01

    Boundedly rational heuristics for inference can be surprisingly accurate and frugal for several reasons. They can exploit environmental structures, co-opt complex capacities, and elude effortful search by exploiting information that automatically arrives on the mental stage. The fluency heuristic is a prime example of a heuristic that makes the…

  11. Heuristic Literacy Development and Its Relation to Mathematical Achievements of Middle School Students

    ERIC Educational Resources Information Center

    Koichu, Boris; Berman, Abraham; Moore, Michael

    2007-01-01

    The relationships between heuristic literacy development and mathematical achievements of middle school students were explored during a 5-month classroom experiment in two 8th grade classes (N = 37). By heuristic literacy we refer to an individual's capacity to use heuristic vocabulary in problem-solving discourse and to approach scholastic…

  12. Investigating the Impacts of Design Heuristics on Idea Initiation and Development

    ERIC Educational Resources Information Center

    Kramer, Julia; Daly, Shanna R.; Yilmaz, Seda; Seifert, Colleen M.; Gonzalez, Richard

    2015-01-01

    This paper presents an analysis of engineering students' use of Design Heuristics as part of a team project in an undergraduate engineering design course. Design Heuristics are an empirically derived set of cognitive "rules of thumb" for use in concept generation. We investigated heuristic use in the initial concept generation phase,…

  13. Sequential Insertion Heuristic with Adaptive Bee Colony Optimisation Algorithm for Vehicle Routing Problem with Time Windows

    PubMed Central

    Jawarneh, Sana; Abdullah, Salwani

    2015-01-01

    This paper presents a bee colony optimisation (BCO) algorithm to tackle the vehicle routing problem with time window (VRPTW). The VRPTW involves recovering an ideal set of routes for a fleet of vehicles serving a defined number of customers. The BCO algorithm is a population-based algorithm that mimics the social communication patterns of honeybees in solving problems. The performance of the BCO algorithm is dependent on its parameters, so the online (self-adaptive) parameter tuning strategy is used to improve its effectiveness and robustness. Compared with the basic BCO, the adaptive BCO performs better. Diversification is crucial to the performance of the population-based algorithm, but the initial population in the BCO algorithm is generated using a greedy heuristic, which has insufficient diversification. Therefore the ways in which the sequential insertion heuristic (SIH) for the initial population drives the population toward improved solutions are examined. Experimental comparisons indicate that the proposed adaptive BCO-SIH algorithm works well across all instances and is able to obtain 11 best results in comparison with the best-known results in the literature when tested on Solomon’s 56 VRPTW 100 customer instances. Also, a statistical test shows that there is a significant difference between the results. PMID:26132158

  14. Heuristic Identification of Biological Architectures for Simulating Complex Hierarchical Genetic Interactions

    PubMed Central

    Moore, Jason H; Amos, Ryan; Kiralis, Jeff; Andrews, Peter C

    2015-01-01

    Simulation plays an essential role in the development of new computational and statistical methods for the genetic analysis of complex traits. Most simulations start with a statistical model using methods such as linear or logistic regression that specify the relationship between genotype and phenotype. This is appealing due to its simplicity and because these statistical methods are commonly used in genetic analysis. It is our working hypothesis that simulations need to move beyond simple statistical models to more realistically represent the biological complexity of genetic architecture. The goal of the present study was to develop a prototype genotype–phenotype simulation method and software that are capable of simulating complex genetic effects within the context of a hierarchical biology-based framework. Specifically, our goal is to simulate multilocus epistasis or gene–gene interaction where the genetic variants are organized within the framework of one or more genes, their regulatory regions and other regulatory loci. We introduce here the Heuristic Identification of Biological Architectures for simulating Complex Hierarchical Interactions (HIBACHI) method and prototype software for simulating data in this manner. This approach combines a biological hierarchy, a flexible mathematical framework, a liability threshold model for defining disease endpoints, and a heuristic search strategy for identifying high-order epistatic models of disease susceptibility. We provide several simulation examples using genetic models exhibiting independent main effects and three-way epistatic effects. PMID:25395175

  15. Heuristic use of perceptual evidence leads to dissociation between performance and metacognitive sensitivity.

    PubMed

    Maniscalco, Brian; Peters, Megan A K; Lau, Hakwan

    2016-04-01

    Zylberberg et al. [Zylberberg, Barttfeld, & Sigman (Frontiers in Integrative Neuroscience, 6; 79, 2012), Frontiers in Integrative Neuroscience 6:79] found that confidence decisions, but not perceptual decisions, are insensitive to evidence against a selected perceptual choice. We present a signal detection theoretic model to formalize this insight, which gave rise to a counter-intuitive empirical prediction: that depending on the observer's perceptual choice, increasing task performance can be associated with decreasing metacognitive sensitivity (i.e., the trial-by-trial correspondence between confidence and accuracy). The model also provides an explanation as to why metacognitive sensitivity tends to be less than optimal in actual subjects. These predictions were confirmed robustly in a psychophysics experiment. In a second experiment we found that, in at least some subjects, the effects were replicated even under performance feedback designed to encourage optimal behavior. However, some subjects did show improvement under feedback, suggesting the tendency to ignore evidence against a selected perceptual choice may be a heuristic adopted by the perceptual decision-making system, rather than reflecting inherent biological limitations. We present a Bayesian modeling framework that explains why this heuristic strategy may be advantageous in real-world contexts. PMID:26791233

  16. Heuristics to Evaluate Interactive Systems for Children with Autism Spectrum Disorder (ASD)

    PubMed Central

    Khowaja, Kamran; Salim, Siti Salwah

    2015-01-01

    In this paper, we adapted and expanded a set of guidelines, also known as heuristics, to evaluate the usability of software to now be appropriate for software aimed at children with autism spectrum disorder (ASD). We started from the heuristics developed by Nielsen in 1990 and developed a modified set of 15 heuristics. The first 5 heuristics of this set are the same as those of the original Nielsen set, the next 5 heuristics are improved versions of Nielsen's, whereas the last 5 heuristics are new. We present two evaluation studies of our new heuristics. In the first, two groups compared Nielsen’s set with the modified set of heuristics, with each group evaluating two interactive systems. The Nielsen’s heuristics were assigned to the control group while the experimental group was given the modified set of heuristics, and a statistical analysis was conducted to determine the effectiveness of the modified set, the contribution of 5 new heuristics and the impact of 5 improved heuristics. The results show that the modified set is significantly more effective than the original, and we found a significant difference between the five improved heuristics and their corresponding heuristics in the original set. The five new heuristics are effective in problem identification using the modified set. The second study was conducted using a system which was developed to ascertain if the modified set was effective at identifying usability problems that could be fixed before the release of software. The post-study analysis revealed that the majority of the usability problems identified by the experts were fixed in the updated version of the system. PMID:26196385

  17. Worst-case analysis of self-organizing sequential search heuristics

    SciTech Connect

    Bentley, J.L.; McGeoch, C.C.

    1983-03-01

    The performance of sequential search can be enhanced by the use of heuristics that move elements closer to the front of the list as they are found. Previous analyses have characterized the performance of such heuristics probabilitically. In this paper we show that the heuristics can also be analyzed in the worst-case sense, and that the relative merit of the heuristics under this analysis is different than in the probabilistic analyses. Simulations show that the relative merit of the heuristics on real data is closer to that of the new worst-case analyses rather than that of the previous probabilistic analyses.

  18. Task Assignment Heuristics for Parallel and Distributed CFD Applications

    NASA Technical Reports Server (NTRS)

    Lopez-Benitez, Noe; Djomehri, M. Jahed; Biswas, Rupak

    2003-01-01

    This paper proposes a task graph (TG) model to represent a single discrete step of multi-block overset grid computational fluid dynamics (CFD) applications. The TG model is then used to not only balance the computational workload across the overset grids but also to reduce inter-grid communication costs. We have developed a set of task assignment heuristics based on the constraints inherent in this class of CFD problems. Two basic assignments, the smallest task first (STF) and the largest task first (LTF), are first presented. They are then systematically costs. To predict the performance of the proposed task assignment heuristics, extensive performance evaluations are conducted on a synthetic TG with tasks defined in terms of the number of grid points in predetermined overlapping grids. A TG derived from a realistic problem with eight million grid points is also used as a test case.

  19. A heuristic approach to incremental and reactive scheduling

    NASA Technical Reports Server (NTRS)

    Odubiyi, Jide B.; Zoch, David R.

    1989-01-01

    An heuristic approach to incremental and reactive scheduling is described. Incremental scheduling is the process of modifying an existing schedule if the initial schedule does not meet its stated initial goals. Reactive scheduling occurs in near real-time in response to changes in available resources or the occurrence of targets of opportunity. Only minor changes are made during both incremental and reactive scheduling because a goal of re-scheduling procedures is to minimally impact the schedule. The described heuristic search techniques, which are employed by the Request Oriented Scheduling Engine (ROSE), a prototype generic scheduler, efficiently approximate the cost of reaching a goal from a given state and effective mechanisms for controlling search.

  20. Unsafe sex: decision-making biases and heuristics.

    PubMed

    Kaplan, B J; Shayne, V T

    1993-01-01

    This paper suggests that continued high-risk behavior is the result of the heuristics used to make judgments under uncertainty, and that the same heuristics may be mobilized to increase the use of safer-sex practices. In order to explain why it is that individuals fail to make effective use of the information they may have concerning rates of infection, consequences of infection and their own at-risk status, theory and research in several areas will be considered. Developments in the breadth of areas to which basic research on decision-making has been applied continue to provide new approaches toward understanding and overcoming the processes by which we reason (Kahnemann, 1991). It is worth reminding ourselves that public health campaigns in other areas have led to changes in behavior. Reasoning, even with its biases, is still the route by which we make decisions, most of them effective and self-protective. PMID:8297709

  1. The source of the truth bias: Heuristic processing?

    PubMed

    Street, Chris N H; Masip, Jaume

    2015-06-01

    People believe others are telling the truth more often than they actually are; this is called the truth bias. Surprisingly, when a speaker is judged at multiple points across their statement the truth bias declines. Previous claims argue this is evidence of a shift from (biased) heuristic processing to (reasoned) analytical processing. In four experiments we contrast the heuristic-analytic model (HAM) with alternative accounts. In Experiment 1, the decrease in truth responding was not the result of speakers appearing more deceptive, but was instead attributable to the rater's processing style. Yet contrary to HAMs, across three experiments we found the decline in bias was not related to the amount of processing time available (Experiments 1-3) or the communication channel (Experiment 2). In Experiment 4 we found support for a new account: that the bias reflects whether raters perceive the statement to be internally consistent. PMID:25707774

  2. Deterministic algorithm with agglomerative heuristic for location problems

    NASA Astrophysics Data System (ADS)

    Kazakovtsev, L.; Stupina, A.

    2015-10-01

    Authors consider the clustering problem solved with the k-means method and p-median problem with various distance metrics. The p-median problem and the k-means problem as its special case are most popular models of the location theory. They are implemented for solving problems of clustering and many practically important logistic problems such as optimal factory or warehouse location, oil or gas wells, optimal drilling for oil offshore, steam generators in heavy oil fields. Authors propose new deterministic heuristic algorithm based on ideas of the Information Bottleneck Clustering and genetic algorithms with greedy heuristic. In this paper, results of running new algorithm on various data sets are given in comparison with known deterministic and stochastic methods. New algorithm is shown to be significantly faster than the Information Bottleneck Clustering method having analogous preciseness.

  3. A simple heuristic for blindfolded record linkage

    PubMed Central

    Lowe, Henry; Das, Amar; Ferris, Todd

    2012-01-01

    Objectives To address the challenge of balancing privacy with the need to create cross-site research registry records on individual patients, while matching the data for a given patient as he or she moves between participating sites. To evaluate the strategy of generating anonymous identifiers based on real identifiers in such a way that the chances of a shared patient being accurately identified were maximized, and the chances of incorrectly joining two records belonging to different people were minimized. Methods Our hypothesis was that most variation in names occurs after the first two letters, and that date of birth is highly reliable, so a single match variable consisting of a hashed string built from the first two letters of the patient's first and last names plus their date of birth would have the desired characteristics. We compared and contrasted the match algorithm characteristics (rate of false positive v. rate of false negative) for our chosen variable against both Social Security Numbers and full names. Results In a data set of 19 000 records, a derived match variable consisting of a 2-character prefix from both first and last names combined with date of birth has a 97% sensitivity; by contrast, an anonymized identifier based on the patient's full names and date of birth has a sensitivity of only 87% and SSN has sensitivity 86%. Conclusion The approach we describe is most useful in situations where privacy policies preclude the full exchange of the identifiers required by more sophisticated and sensitive linkage algorithms. For data sets of sufficiently high quality this effective approach, while producing a lower rate of matching than more complex algorithms, has the merit of being easy to explain to institutional review boards, adheres to the minimum necessary rule of the HIPAA privacy rule, and is faster and less cumbersome to implement than a full probabilistic linkage. PMID:22298567

  4. Humans use Compression Heuristics to Improve the Recall of Social Networks

    PubMed Central

    Brashears, Matthew E.

    2013-01-01

    The ability of primates, including humans, to maintain large social networks appears to depend on the ratio of the neocortex to the rest of the brain. However, observed human network size frequently exceeds predictions based on this ratio (e.g., “Dunbar’s Number”), implying that human networks are too large to be cognitively managed. Here I show that humans adaptively use compression heuristics to allow larger amounts of social information to be stored in the same brain volume. I find that human adults can remember larger numbers of relationships in greater detail when a network exhibits triadic closure and kin labels than when it does not. These findings help to explain how humans manage large and complex social networks with finite cognitive resources and suggest that many of the unusual properties of human social networks are rooted in the strategies necessary to cope with cognitive limitations. PMID:23515066

  5. A heuristic finite-state model of the human driver in a car-following situation

    NASA Technical Reports Server (NTRS)

    Burnham, G. O.; Bekey, G. A.

    1976-01-01

    An approach to modeling human driver behavior in single-lane car following which is based on a finite-state decision structure is considered. The specific strategy at each point in the decision tree was obtained from observations of typical driver behavior. The synthesis of the decision logic is based on position and velocity thresholds and four states defined by regions in the phase plane. The performance of the resulting assumed intuitively logical model was compared with actual freeway data. The match of the model to the data was optimized by adapting the model parameters using a modified PARTAN algorithm. The results indicate that the heuristic model behavior matches actual car-following performance better during deceleration and constant velocity phases than during acceleration periods.

  6. Symbolic Heuristic Search for Factored Markov Decision Processes

    NASA Technical Reports Server (NTRS)

    Morris, Robert (Technical Monitor); Feng, Zheng-Zhu; Hansen, Eric A.

    2003-01-01

    We describe a planning algorithm that integrates two approaches to solving Markov decision processes with large state spaces. State abstraction is used to avoid evaluating states individually. Forward search from a start state, guided by an admissible heuristic, is used to avoid evaluating all states. We combine these two approaches in a novel way that exploits symbolic model-checking techniques and demonstrates their usefulness for decision-theoretic planning.

  7. VHP - An environment for the remote visualization of heuristic processes

    NASA Technical Reports Server (NTRS)

    Crawford, Stuart L.; Leiner, Barry M.

    1991-01-01

    A software system called VHP is introduced which permits the visualization of heuristic algorithms on both resident and remote hardware platforms. The VHP is based on the DCF tool for interprocess communication and is applicable to remote algorithms which can be on different types of hardware and in languages other than VHP. The VHP system is of particular interest to systems in which the visualization of remote processes is required such as robotics for telescience applications.

  8. Multiobjective hyper heuristic scheme for system design and optimization

    NASA Astrophysics Data System (ADS)

    Rafique, Amer Farhan

    2012-11-01

    As system design is becoming more and more multifaceted, integrated, and complex, the traditional single objective optimization trends of optimal design are becoming less and less efficient and effective. Single objective optimization methods present a unique optimal solution whereas multiobjective methods present pareto front. The foremost intent is to predict a reasonable distributed pareto-optimal solution set independent of the problem instance through multiobjective scheme. Other objective of application of intended approach is to improve the worthiness of outputs of the complex engineering system design process at the conceptual design phase. The process is automated in order to provide the system designer with the leverage of the possibility of studying and analyzing a large multiple of possible solutions in a short time. This article presents Multiobjective Hyper Heuristic Optimization Scheme based on low level meta-heuristics developed for the application in engineering system design. Herein, we present a stochastic function to manage meta-heuristics (low-level) to augment surety of global optimum solution. Generic Algorithm, Simulated Annealing and Swarm Intelligence are used as low-level meta-heuristics in this study. Performance of the proposed scheme is investigated through a comprehensive empirical analysis yielding acceptable results. One of the primary motives for performing multiobjective optimization is that the current engineering systems require simultaneous optimization of conflicting and multiple. Random decision making makes the implementation of this scheme attractive and easy. Injecting feasible solutions significantly alters the search direction and also adds diversity of population resulting in accomplishment of pre-defined goals set in the proposed scheme.

  9. Bose-Einstein condensates form in heuristics learned by ciliates deciding to signal 'social' commitments.

    PubMed

    Clark, Kevin B

    2010-03-01

    Fringe quantum biology theories often adopt the concept of Bose-Einstein condensation when explaining how consciousness, emotion, perception, learning, and reasoning emerge from operations of intact animal nervous systems and other computational media. However, controversial empirical evidence and mathematical formalism concerning decoherence rates of bioprocesses keep these frameworks from satisfactorily accounting for the physical nature of cognitive-like events. This study, inspired by the discovery that preferential attachment rules computed by complex technological networks obey Bose-Einstein statistics, is the first rigorous attempt to examine whether analogues of Bose-Einstein condensation precipitate learned decision making in live biological systems as bioenergetics optimization predicts. By exploiting the ciliate Spirostomum ambiguum's capacity to learn and store behavioral strategies advertising mating availability into heuristics of topologically invariant computational networks, three distinct phases of strategy use were found to map onto statistical distributions described by Bose-Einstein, Fermi-Dirac, and classical Maxwell-Boltzmann behavior. Ciliates that sensitized or habituated signaling patterns to emit brief periods of either deceptive 'harder-to-get' or altruistic 'easier-to-get' serial escape reactions began testing condensed on initially perceived fittest 'courting' solutions. When these ciliates switched from their first strategy choices, Bose-Einstein condensation of strategy use abruptly dissipated into a Maxwell-Boltzmann computational phase no longer dominated by a single fittest strategy. Recursive trial-and-error strategy searches annealed strategy use back into a condensed phase consistent with performance optimization. 'Social' decisions performed by ciliates showing no nonassociative learning were largely governed by Fermi-Dirac statistics, resulting in degenerate distributions of strategy choices. These findings corroborate

  10. Heuristic approach to deriving models for gene finding.

    PubMed

    Besemer, J; Borodovsky, M

    1999-10-01

    Computer methods of accurate gene finding in DNA sequences require models of protein coding and non-coding regions derived either from experimentally validated training sets or from large amounts of anonymous DNA sequence. Here we propose a new, heuristic method producing fairly accurate inhomogeneous Markov models of protein coding regions. The new method needs such a small amount of DNA sequence data that the model can be built 'on the fly' by a web server for any DNA sequence >400 nt. Tests on 10 complete bacterial genomes performed with the GeneMark.hmm program demonstrated the ability of the new models to detect 93.1% of annotated genes on average, while models built by traditional training predict an average of 93.9% of genes. Models built by the heuristic approach could be used to find genes in small fragments of anonymous prokaryotic genomes and in genomes of organelles, viruses, phages and plasmids, as well as in highly inhomogeneous genomes where adjustment of models to local DNA composition is needed. The heuristic method also gives an insight into the mechanism of codon usage pattern evolution. PMID:10481031

  11. Bflinks: Reliable Bugfix Links via Bidirectional References and Tuned Heuristics

    PubMed Central

    2014-01-01

    Background. Data from software version archives and defect databases can be used for defect insertion circumstance analysis and defect prediction. The first step in such analyses is identifying defect-correcting changes in the version archive (bugfix commits) and enriching them with additional metadata by establishing bugfix links to corresponding entries in the defect database. Candidate bugfix commits are typically identified via heuristic string matching on the commit message. Research Questions. Which filters could be used to obtain a set of bugfix links? How to tune their parameters? What accuracy is achieved? Method. We analyze a modular set of seven independent filters, including new ones that make use of reverse links, and evaluate visual heuristics for setting cutoff parameters. For a commercial repository, a product expert manually verifies over 2500 links to validate the results with unprecedented accuracy. Results. The heuristics pick a very good parameter value for five filters and a reasonably good one for the sixth. The combined filtering, called bflinks, provides 93% precision and only 7% results loss. Conclusion. Bflinks can provide high-quality results and adapts to repositories with different properties. PMID:27433506

  12. Recipient design in human communication: simple heuristics or perspective taking?

    PubMed Central

    Blokpoel, Mark; van Kesteren, Marlieke; Stolk, Arjen; Haselager, Pim; Toni, Ivan; van Rooij, Iris

    2012-01-01

    Humans have a remarkable capacity for tuning their communicative behaviors to different addressees, a phenomenon also known as recipient design. It remains unclear how this tuning of communicative behavior is implemented during live human interactions. Classical theories of communication postulate that recipient design involves perspective taking, i.e., the communicator selects her behavior based on her hypotheses about beliefs and knowledge of the recipient. More recently, researchers have argued that perspective taking is computationally too costly to be a plausible mechanism in everyday human communication. These researchers propose that computationally simple mechanisms, or heuristics, are exploited to perform recipient design. Such heuristics may be able to adapt communicative behavior to an addressee with no consideration for the addressee's beliefs and knowledge. To test whether the simpler of the two mechanisms is sufficient for explaining the “how” of recipient design we studied communicators' behaviors in the context of a non-verbal communicative task (the Tacit Communication Game, TCG). We found that the specificity of the observed trial-by-trial adjustments made by communicators is parsimoniously explained by perspective taking, but not by simple heuristics. This finding is important as it suggests that humans do have a computationally efficient way of taking beliefs and knowledge of a recipient into account. PMID:23055960

  13. General heuristics algorithms for solving capacitated arc routing problem

    NASA Astrophysics Data System (ADS)

    Fadzli, Mohammad; Najwa, Nurul; Masran, Hafiz

    2015-05-01

    In this paper, we try to determine the near-optimum solution for the capacitated arc routing problem (CARP). In general, NP-hard CARP is a special graph theory specifically arises from street services such as residential waste collection and road maintenance. By purpose, the design of the CARP model and its solution techniques is to find optimum (or near-optimum) routing cost for a fleet of vehicles involved in operation. In other words, finding minimum-cost routing is compulsory in order to reduce overall operation cost that related with vehicles. In this article, we provide a combination of various heuristics algorithm to solve a real case of CARP in waste collection and benchmark instances. These heuristics work as a central engine in finding initial solutions or near-optimum in search space without violating the pre-setting constraints. The results clearly show that these heuristics algorithms could provide good initial solutions in both real-life and benchmark instances.

  14. Heuristic and analytic processing in online sports betting.

    PubMed

    d'Astous, Alain; Di Gaspero, Marc

    2015-06-01

    This article presents the results of two studies that examine the occurrence of heuristic (i.e., intuitive and fast) and analytic (i.e., deliberate and slow) processes among people who engage in online sports betting on a regular basis. The first study was qualitative and was conducted with a convenience sample of 12 regular online sports gamblers who described the processes by which they arrive at a sports betting decision. The results of this study showed that betting online on sports events involves a mix of heuristic and analytic processes. The second study consisted in a survey of 161 online sports gamblers where performance in terms of monetary gains, experience in online sports betting, propensity to collect and analyze relevant information prior to betting, and use of bookmaker odds were measured. This study showed that heuristic and analytic processes act as mediators of the relationship between experience and performance. The findings stemming of these two studies give some insights into gamblers' modes of thinking and behaviors in an online sports betting context and show the value of the dual mediation process model for research that looks at gambling activities from a judgment and decision making perspective. PMID:24390714

  15. Visualization for Hyper-Heuristics: Back-End Processing

    SciTech Connect

    Simon, Luke

    2015-03-01

    Modern society is faced with increasingly complex problems, many of which can be formulated as generate-and-test optimization problems. Yet, general-purpose optimization algorithms may sometimes require too much computational time. In these instances, hyperheuristics may be used. Hyper-heuristics automate the design of algorithms to create a custom algorithm for a particular scenario, finding the solution significantly faster than its predecessor. However, it may be difficult to understand exactly how a design was derived and why it should be trusted. This project aims to address these issues by creating an easy-to-use graphical user interface (GUI) for hyper-heuristics and an easy-to-understand scientific visualization for the produced solutions. To support the development of this GUI, my portion of the research involved developing algorithms that would allow for parsing of the data produced by the hyper-heuristics. This data would then be sent to the front-end, where it would be displayed to the end user.

  16. Tuning Parameters in Heuristics by Using Design of Experiments Methods

    NASA Technical Reports Server (NTRS)

    Arin, Arif; Rabadi, Ghaith; Unal, Resit

    2010-01-01

    With the growing complexity of today's large scale problems, it has become more difficult to find optimal solutions by using exact mathematical methods. The need to find near-optimal solutions in an acceptable time frame requires heuristic approaches. In many cases, however, most heuristics have several parameters that need to be "tuned" before they can reach good results. The problem then turns into "finding best parameter setting" for the heuristics to solve the problems efficiently and timely. One-Factor-At-a-Time (OFAT) approach for parameter tuning neglects the interactions between parameters. Design of Experiments (DOE) tools can be instead employed to tune the parameters more effectively. In this paper, we seek the best parameter setting for a Genetic Algorithm (GA) to solve the single machine total weighted tardiness problem in which n jobs must be scheduled on a single machine without preemption, and the objective is to minimize the total weighted tardiness. Benchmark instances for the problem are available in the literature. To fine tune the GA parameters in the most efficient way, we compare multiple DOE models including 2-level (2k ) full factorial design, orthogonal array design, central composite design, D-optimal design and signal-to-noise (SIN) ratios. In each DOE method, a mathematical model is created using regression analysis, and solved to obtain the best parameter setting. After verification runs using the tuned parameter setting, the preliminary results for optimal solutions of multiple instances were found efficiently.

  17. Investigating the effectiveness of implementing the Science Writing Heuristic on student performance in general chemistry

    NASA Astrophysics Data System (ADS)

    Poock, Jason Ray

    This research investigated the effectiveness at how the Science Writing Heuristic in the freshman chemistry laboratory for science and engineering majors at Iowa State University during the fall and spring semesters of the 2002--2003 academic year, was implemented. The Science Writing Heuristic (SWH) consists of two components, writing to learn strategies and conducting the laboratory session in a student-centered, guided-inquiry fashion. The writing component replaced the standard laboratory report with a series of questions that guided the students' critical thinking along the lines of scientific investigation. The writing process helped students construct knowledge. Also critical to the successful implementation of the SWH was conducting the laboratory experiments in a student-centered, guided-inquiry fashion. Through the SWH the students became engaged in meaningful scientific dialogue that promoted knowledge construction. For the SWH to be properly implemented, a classroom dynamic between the teacher and the students should be established. The teacher provides the framework within which the laboratory experiment is conducted and the students respond to that guidance by becoming engaged in the learning process. Results of the study showed that student scores improved when the teacher properly implemented the SWH, when the students responded positively to the implementation of the SWH, and when there was a proper classroom dynamic created between the teacher and the students. This study revealed that successful implementation of the SWH was beneficial to females and low ability students. This research also demonstrated a connection between the implementation of a learning strategy in the laboratory component of a course and the subsequent benefit in student performance in the lecture component of the course.

  18. Extending Students' Practice of Metacognitive Regulation Skills with the Science Writing Heuristic

    NASA Astrophysics Data System (ADS)

    van Opstal, Mary T.; Daubenmire, Patrick L.

    2015-05-01

    Metacognition can be described as an internal conversation that seeks to answer the questions, 'how much do I really know about what I am learning' and, 'how am I monitoring what I am learning?' Metacognitive regulation skills are critical to meaningful learning because they facilitate the abilities to recognize the times when one's current level of understanding is insufficient and to identify the needs for closing the gap in understanding. This research explored how using the Science Writing Heuristic (SWH) as an instructional approach in a laboratory classroom affected students' practice of metacognitive skills while solving open-ended laboratory problems. Within our qualitative research design, results demonstrate that students in the SWH environment, compared to non-SWH students, used metacognitive strategies to a different degree and to a different depth when solving open-ended laboratory problems. As students engaged in higher levels of metacognitive regulation, peer collaboration became a prominent path for supporting the use of metacognitive strategies. Students claimed that the structure of the SWH weekly laboratory experiments improved their ability to solve open-ended lab problems. Results from this study suggest that using instruction that encourages practice of metacognitive strategies can improve students' use of these strategies.

  19. Planning collision free paths for two cooperating robots using a divide-and-conquer C-space traversal heuristic

    NASA Technical Reports Server (NTRS)

    Weaver, Johnathan M.

    1993-01-01

    A method was developed to plan feasible and obstacle-avoiding paths for two spatial robots working cooperatively in a known static environment. Cooperating spatial robots as referred to herein are robots which work in 6D task space while simultaneously grasping and manipulating a common, rigid payload. The approach is configuration space (c-space) based and performs selective rather than exhaustive c-space mapping. No expensive precomputations are required. A novel, divide-and-conquer type of heuristic is used to guide the selective mapping process. The heuristic does not involve any robot, environment, or task specific assumptions. A technique was also developed which enables solution of the cooperating redundant robot path planning problem without requiring the use of inverse kinematics for a redundant robot. The path planning strategy involves first attempting to traverse along the configuration space vector from the start point towards the goal point. If an unsafe region is encountered, an intermediate via point is identified by conducting a systematic search in the hyperplane orthogonal to and bisecting the unsafe region of the vector. This process is repeatedly applied until a solution to the global path planning problem is obtained. The basic concept behind this strategy is that better local decisions at the beginning of the trouble region may be made if a possible way around the 'center' of the trouble region is known. Thus, rather than attempting paths which look promising locally (at the beginning of a trouble region) but which may not yield overall results, the heuristic attempts local strategies that appear promising for circumventing the unsafe region.

  20. Stick or Switch: A Selection Heuristic Predicts when People Take the Perspective of Others or Communicate Egocentrically.

    PubMed

    Rogers, Shane L; Fay, Nicolas

    2016-01-01

    This paper examines a cognitive mechanism that drives perspective-taking and egocentrism in interpersonal communication. Using a conceptual referential communication task, in which participants describe a range of abstract geometric shapes, Experiment 1 shows that perspective-taking and egocentric communication are frequent communication strategies. Experiment 2 tests a selection heuristic account of perspective-taking and egocentric communication. It uses participants' shape description ratings to predict their communication strategy. Participants' communication strategy was predicted by how informative they perceived the different shape descriptions to be. When participants' personal shape description was perceived to be more informative than their addressee's shape description, there was a strong bias to communicate egocentrically. By contrast, when their addressee's shape description was perceived to be more informative, there was a strong bias to take their addressee's perspective. When the shape descriptions were perceived to be equally informative, there was a moderate bias to communicate egocentrically. This simple, but powerful, selection heuristic may be critical to the cumulative cultural evolution of human communication systems, and cumulative cultural evolution more generally. PMID:27437694

  1. Stick or Switch: A Selection Heuristic Predicts when People Take the Perspective of Others or Communicate Egocentrically

    PubMed Central

    Rogers, Shane L.; Fay, Nicolas

    2016-01-01

    This paper examines a cognitive mechanism that drives perspective-taking and egocentrism in interpersonal communication. Using a conceptual referential communication task, in which participants describe a range of abstract geometric shapes, Experiment 1 shows that perspective-taking and egocentric communication are frequent communication strategies. Experiment 2 tests a selection heuristic account of perspective-taking and egocentric communication. It uses participants’ shape description ratings to predict their communication strategy. Participants’ communication strategy was predicted by how informative they perceived the different shape descriptions to be. When participants’ personal shape description was perceived to be more informative than their addressee’s shape description, there was a strong bias to communicate egocentrically. By contrast, when their addressee’s shape description was perceived to be more informative, there was a strong bias to take their addressee’s perspective. When the shape descriptions were perceived to be equally informative, there was a moderate bias to communicate egocentrically. This simple, but powerful, selection heuristic may be critical to the cumulative cultural evolution of human communication systems, and cumulative cultural evolution more generally. PMID:27437694

  2. From Metaphors to Formalism: A Heuristic Approach to Holistic Assessments of Ecosystem Health

    PubMed Central

    Kraus, Gerd

    2016-01-01

    Environmental policies employ metaphoric objectives such as ecosystem health, resilience and sustainable provision of ecosystem services, which influence corresponding sustainability assessments by means of normative settings such as assumptions on system description, indicator selection, aggregation of information and target setting. A heuristic approach is developed for sustainability assessments to avoid ambiguity and applications to the EU Marine Strategy Framework Directive (MSFD) and OSPAR assessments are presented. For MSFD, nineteen different assessment procedures have been proposed, but at present no agreed assessment procedure is available. The heuristic assessment framework is a functional-holistic approach comprising an ex-ante/ex-post assessment framework with specifically defined normative and systemic dimensions (EAEPNS). The outer normative dimension defines the ex-ante/ex-post framework, of which the latter branch delivers one measure of ecosystem health based on indicators and the former allows to account for the multi-dimensional nature of sustainability (social, economic, ecological) in terms of modeling approaches. For MSFD, the ex-ante/ex-post framework replaces the current distinction between assessments based on pressure and state descriptors. The ex-ante and the ex-post branch each comprise an inner normative and a systemic dimension. The inner normative dimension in the ex-post branch considers additive utility models and likelihood functions to standardize variables normalized with Bayesian modeling. Likelihood functions allow precautionary target setting. The ex-post systemic dimension considers a posteriori indicator selection by means of analysis of indicator space to avoid redundant indicator information as opposed to a priori indicator selection in deconstructive-structural approaches. Indicator information is expressed in terms of ecosystem variability by means of multivariate analysis procedures. The application to the OSPAR

  3. From Metaphors to Formalism: A Heuristic Approach to Holistic Assessments of Ecosystem Health.

    PubMed

    Fock, Heino O; Kraus, Gerd

    2016-01-01

    Environmental policies employ metaphoric objectives such as ecosystem health, resilience and sustainable provision of ecosystem services, which influence corresponding sustainability assessments by means of normative settings such as assumptions on system description, indicator selection, aggregation of information and target setting. A heuristic approach is developed for sustainability assessments to avoid ambiguity and applications to the EU Marine Strategy Framework Directive (MSFD) and OSPAR assessments are presented. For MSFD, nineteen different assessment procedures have been proposed, but at present no agreed assessment procedure is available. The heuristic assessment framework is a functional-holistic approach comprising an ex-ante/ex-post assessment framework with specifically defined normative and systemic dimensions (EAEPNS). The outer normative dimension defines the ex-ante/ex-post framework, of which the latter branch delivers one measure of ecosystem health based on indicators and the former allows to account for the multi-dimensional nature of sustainability (social, economic, ecological) in terms of modeling approaches. For MSFD, the ex-ante/ex-post framework replaces the current distinction between assessments based on pressure and state descriptors. The ex-ante and the ex-post branch each comprise an inner normative and a systemic dimension. The inner normative dimension in the ex-post branch considers additive utility models and likelihood functions to standardize variables normalized with Bayesian modeling. Likelihood functions allow precautionary target setting. The ex-post systemic dimension considers a posteriori indicator selection by means of analysis of indicator space to avoid redundant indicator information as opposed to a priori indicator selection in deconstructive-structural approaches. Indicator information is expressed in terms of ecosystem variability by means of multivariate analysis procedures. The application to the OSPAR

  4. A heuristic re-mapping algorithm reducing inter-level communication in SAMR applications.

    SciTech Connect

    Steensland, Johan; Ray, Jaideep

    2003-07-01

    This paper aims at decreasing execution time for large-scale structured adaptive mesh refinement (SAMR) applications by proposing a new heuristic re-mapping algorithm and experimentally showing its effectiveness in reducing inter-level communication. Tests were done for five different SAMR applications. The overall goal is to engineer a dynamically adaptive meta-partitioner capable of selecting and configuring the most appropriate partitioning strategy at run-time based on current system and application state. Such a metapartitioner can significantly reduce execution times for general SAMR applications. Computer simulations of physical phenomena are becoming increasingly popular as they constitute an important complement to real-life testing. In many cases, such simulations are based on solving partial differential equations by numerical methods. Adaptive methods are crucial to efficiently utilize computer resources such as memory and CPU. But even with adaption, the simulations are computationally demanding and yield huge data sets. Thus parallelization and the efficient partitioning of data become issues of utmost importance. Adaption causes the workload to change dynamically, calling for dynamic (re-) partitioning to maintain efficient resource utilization. The proposed heuristic algorithm reduced inter-level communication substantially. Since the complexity of the proposed algorithm is low, this decrease comes at a relatively low cost. As a consequence, we draw the conclusion that the proposed re-mapping algorithm would be useful to lower overall execution times for many large SAMR applications. Due to its usefulness and its parameterization, the proposed algorithm would constitute a natural and important component of the meta-partitioner.

  5. Money Earlier or Later? Simple Heuristics Explain Intertemporal Choices Better than Delay Discounting1

    PubMed Central

    Marzilli Ericson, Keith M.; White, John Myles; Laibson, David; Cohen, Jonathan D.

    2015-01-01

    Heuristic models have been proposed for many domains of choice. We compare heuristic models of intertemporal choice, which can account for many of the known intertemporal choice anomalies, to discounting models. We conduct an out-of-sample, cross-validated comparison of intertemporal choice models. Heuristic models outperform traditional utility discounting models, including models of exponential and hyperbolic discounting. The best performing models predict choices by using a weighted average of absolute differences and relative (percentage) differences of the attributes of the goods in a choice set. We conclude that heuristic models explain time-money tradeoff choices in experiments better than utility discounting models. PMID:25911124

  6. SMMH - A Parallel Heuristic for Combinatorial Optimization Problems

    SciTech Connect

    Domingues, Guilherme; Morie, Yoshiyuki; Gu, Feng Long; Nanri, Takeshi; Murakami, Kazuaki

    2007-12-26

    The process of finding one or more optimal solutions for answering combinatorial optimization problems bases itself on the use of algorithms instances. Those instances usually have to explore a very large search spaces. Heuristics search focusing on the use of High-Order Hopfield neural networks is a largely deployed technique for very large search space. It can be established a very powerful analogy towards the dynamics evolution of a physics spin-glass system while minimizing its own energy and the energy function of the network. This paper presents a new approach for solving combinatorial optimization problems through parallel simulations, based on a High-Order Hopfield neural network using MPI specification.

  7. SMMH--A Parallel Heuristic for Combinatorial Optimization Problems

    SciTech Connect

    Domingues, Guilherme; Morie, Yoshiyuki; Gu, Feng Long; Nanri, Takeshi; Murakami, Kazuaki

    2007-12-26

    The process of finding one or more optimal solutions for answering combinatorial optimization problems bases itself on the use of algorithms instances. Those instances usually have to explore a very large search spaces. Heuristics search focusing on the use of High-Order Hopfield neural networks is a largely deployed technique for very large search space. It can be established a very powerful analogy towards the dynamics evolution of a physics spin-glass system while minimizing its own energy and the energy function of the network. This paper presents a new approach for solving combinatorial optimization problems through parallel simulations, based on a High-Order Hopfield neural network using MPI specification.

  8. Heuristic-based scheduling algorithm for high level synthesis

    NASA Technical Reports Server (NTRS)

    Mohamed, Gulam; Tan, Han-Ngee; Chng, Chew-Lye

    1992-01-01

    A new scheduling algorithm is proposed which uses a combination of a resource utilization chart, a heuristic algorithm to estimate the minimum number of hardware units based on operator mobilities, and a list-scheduling technique to achieve fast and near optimal schedules. The schedule time of this algorithm is almost independent of the length of mobilities of operators as can be seen from the benchmark example (fifth order digital elliptical wave filter) presented when the cycle time was increased from 17 to 18 and then to 21 cycles. It is implemented in C on a SUN3/60 workstation.

  9. An architecture for heuristic control of real-time processes

    NASA Technical Reports Server (NTRS)

    Raulefs, P.; Thorndyke, P. W.

    1987-01-01

    Abstract Process management combines complementary approaches of heuristic reasoning and analytical process control. Management of a continuous process requires monitoring the environment and the controlled system, assessing the ongoing situation, developing and revising planned actions, and controlling the execution of the actions. For knowledge-intensive domains, process management entails the potentially time-stressed cooperation among a variety of expert systems. By redesigning a blackboard control architecture in an object-oriented framework, researchers obtain an approach to process management that considerably extends blackboard control mechanisms and overcomes limitations of blackboard systems.

  10. Heuristic optimization in penumbral image for high resolution reconstructed image

    SciTech Connect

    Azuma, R.; Nozaki, S.; Fujioka, S.; Chen, Y. W.; Namihira, Y.

    2010-10-15

    Penumbral imaging is a technique which uses the fact that spatial information can be recovered from the shadow or penumbra that an unknown source casts through a simple large circular aperture. The size of the penumbral image on the detector can be mathematically determined as its aperture size, object size, and magnification. Conventional reconstruction methods are very sensitive to noise. On the other hand, the heuristic reconstruction method is very tolerant of noise. However, the aperture size influences the accuracy and resolution of the reconstructed image. In this article, we propose the optimization of the aperture size for the neutron penumbral imaging.

  11. Some heuristic procedures for analyzing random vibration of nonlinear oscillators.

    NASA Technical Reports Server (NTRS)

    Crandall, S. H.

    1971-01-01

    The stationary response of a lightly damped nonlinear oscillator subjected to wideband random excitation can be examined as an example of thermal equilibrium. It may be assumed that the response consists of a series of free-vibration cycles with small random fluctuations in phase and amplitude. Certain statistical properties of the response can be estimated by averaging corresponding properties of the free vibration with respect to cycle amplitude distributions. Such heuristic procedures for determining the expected frequency and the autocorrelation function of the stationary response are outlined. Some additional results concerning first-passage problems for nonlinear oscillators are included.

  12. Mixed Integer Programming and Heuristic Scheduling for Space Communication Networks

    NASA Technical Reports Server (NTRS)

    Lee, Charles H.; Cheung, Kar-Ming

    2012-01-01

    In this paper, we propose to solve the constrained optimization problem in two phases. The first phase uses heuristic methods such as the ant colony method, particle swarming optimization, and genetic algorithm to seek a near optimal solution among a list of feasible initial populations. The final optimal solution can be found by using the solution of the first phase as the initial condition to the SQP algorithm. We demonstrate the above problem formulation and optimization schemes with a large-scale network that includes the DSN ground stations and a number of spacecraft of deep space missions.

  13. TORC3: Token-ring clearing heuristic for currency circulation

    NASA Astrophysics Data System (ADS)

    Humes, Carlos, Jr.; Lauretto, Marcelo S.; Nakano, Fábio; Pereira, Carlos A. B.; Rafare, Guilherme F. G.; Stern, Julio Michael

    2012-10-01

    Clearing algorithms are at the core of modern payment systems, facilitating the settling of multilateral credit messages with (near) minimum transfers of currency. Traditional clearing procedures use batch processing based on MILP - mixed-integer linear programming algorithms. The MILP approach demands intensive computational resources; moreover, it is also vulnerable to operational risks generated by possible defaults during the inter-batch period. This paper presents TORC3 - the Token-Ring Clearing Algorithm for Currency Circulation. In contrast to the MILP approach, TORC3 is a real time heuristic procedure, demanding modest computational resources, and able to completely shield the clearing operation against the participating agents' risk of default.

  14. Heuristic theory of nonlocally broken gyro-Bohm scaling

    SciTech Connect

    Waltz, R.E.; Candy, J.

    2005-07-15

    Global gyrokinetic simulations of ion temperature gradient turbulent transport with piecewise-flat profiles are given to illustrate the breaking of gyro-Bohm scaling by a nonlocal mechanism. The nonlocal drainage of the turbulence from unstable regions spreading into stable (or less unstable) regions breaks the gyro-Bohm scaling toward Bohm in unstable regions and toward super-gyro-Bohm in stable (or less unstable) regions. A heuristic model for this nonlocal process is formulated in terms of a nonlocal growth rate resulting from a locally weighted radial average of the local linear ballooning mode growth rate. A nonlocality length L measured in ion gyroradii provides the exponential scale for the local weighting. The nonlocal growth rate can be incorporated into a local gyro-Bohm-scaled transport model in place of the local growth rate. The resulting nonlocal transport model will provide some transport in stable regions. A heuristic theory of this nonlocal transport mechanism based on the partial formation of global modes in toroidal geometry is detailed. The theory argues that the nonlocality length L increases with relative gyroradius and decreases with the linear growth rate.

  15. Synergistic Integration Of Heuristic Reasoning In Image Understanding Systems

    NASA Astrophysics Data System (ADS)

    Gilmore, John F.; Shapiro, Sondra S.

    1988-03-01

    The application of knowledge-based processing in image understanding systems has always occurred at a high level. These approaches have generated great claims, but limited results as they are basically simple forward chaining rule systems (e.g., if object on a road, then object is a vehicle). The application of heuristic reasoning to the low-level processing (e.g., image enhancement, segmentation, feature extraction, and classification) is a requirement to provide more accurate object and region information for high-level analysis, and truly integrate artificial intelligence throughout the entire system rather than as a post processing afterthought. This paper addresses the design and development of an integrated knowledge-based vision system in three phases. First, the application of knowledge base system techniques to image understanding is analyzed in light of deficiencies and limitations. This analysis is then exploited to produce a synergistically integrated system design. Second, the application of heuristics to low-level processing is discussed with specific application in the areas of image enhancement and segmentation. Finally, conclusions drawn to date on system performance will be presented in association with a mapping of how they are directing future work in this area.

  16. Facing the grand challenges through heuristics and mindfulness

    NASA Astrophysics Data System (ADS)

    Powietrzynska, Malgorzata; Tobin, Kenneth; Alexakos, Konstantinos

    2015-03-01

    We address the nature of mindfulness and its salience to education generally and to science education specifically. In a context of the historical embeddedness of mindfulness in Buddhism we discuss research in social neuroscience, presenting evidence for neuronal plasticity of the brain and six emotional styles, which are not biologically predetermined, but are responsive to adaptation through life experiences. We raise questions about the role of science education in mediating the structure and function of the brain. Also, we discuss interventions to increase Mindfulness in Education, including meditation and heuristics, that act as reflexive objects to heighten awareness of characteristics of mindfulness and increase the likelihood of changes in the conduct of social life—increasing the mindfulness of those who engage the characteristics included in the heuristic. We present mindfulness and the development of a toolkit for ameliorating emotions when and as necessary as a component of a science curriculum that orientates toward wellness and sustainability. We advocate for changes in the nature of science education to reflect the priorities of the twenty first century that relate to sustainability of the living and nonliving universe and wellness of sentient beings.

  17. A manpower scheduling heuristic for aircraft maintenance application

    NASA Astrophysics Data System (ADS)

    Sze, San-Nah; Sze, Jeeu-Fong; Chiew, Kang-Leng

    2012-09-01

    This research studies a manpower scheduling for aircraft maintenance, focusing on in-flight food loading operation. A group of loading teams with flexible shifts is required to deliver and upload packaged meals from the ground kitchen to aircrafts in multiple trips. All aircrafts must be served within predefined time windows. The scheduling process takes into account of various constraints such as meal break allocation, multi-trip traveling and food exposure time limit. Considering the aircrafts movement and predefined maximum working hours for each loading team, the main objective of this study is to form an efficient roster by assigning a minimum number of loading teams to the aircrafts. We proposed an insertion based heuristic to generate the solutions in a short period of time for large instances. This proposed algorithm is implemented in various stages for constructing trips due to the presence of numerous constraints. The robustness and efficiency of the algorithm is demonstrated in computational results. The results show that the insertion heuristic more efficiently outperforms the company's current practice.

  18. Goal representation heuristic dynamic programming on maze navigation.

    PubMed

    Ni, Zhen; He, Haibo; Wen, Jinyu; Xu, Xin

    2013-12-01

    Goal representation heuristic dynamic programming (GrHDP) is proposed in this paper to demonstrate online learning in the Markov decision process. In addition to the (external) reinforcement signal in literature, we develop an adaptively internal goal/reward representation for the agent with the proposed goal network. Specifically, we keep the actor-critic design in heuristic dynamic programming (HDP) and include a goal network to represent the internal goal signal, to further help the value function approximation. We evaluate our proposed GrHDP algorithm on two 2-D maze navigation problems, and later on one 3-D maze navigation problem. Compared to the traditional HDP approach, the learning performance of the agent is improved with our proposed GrHDP approach. In addition, we also include the learning performance with two other reinforcement learning algorithms, namely Sarsa(λ) and Q-learning, on the same benchmarks for comparison. Furthermore, in order to demonstrate the theoretical guarantee of our proposed method, we provide the characteristics analysis toward the convergence of weights in neural networks in our GrHDP approach. PMID:24805221

  19. Hybrid Evolutionary-Heuristic Algorithm for Capacitor Banks Allocation

    NASA Astrophysics Data System (ADS)

    Barukčić, Marinko; Nikolovski, Srete; Jović, Franjo

    2010-11-01

    The issue of optimal allocation of capacitor banks concerning power losses minimization in distribution networks are considered in this paper. This optimization problem has been recently tackled by application of contemporary soft computing methods such as: genetic algorithms, neural networks, fuzzy logic, simulated annealing, ant colony methods, and hybrid methods. An evolutionaryheuristic method has been proposed for optimal capacitor allocation in radial distribution networks. An evolutionary method based on genetic algorithm is developed. The proposed method has a reduced number of parameters compared to the usual genetic algorithm. A heuristic stage is used for improving the optimal solution given by the evolutionary stage. A new cost-voltage node index is used in the heuristic stage in order to improve the quality of solution. The efficiency of the proposed two-stage method has been tested on different test networks. The quality of solution has been verified by comparison tests with other methods on the same test networks. The proposed method has given significantly better solutions for time dependent load in the 69-bus network than found in references.

  20. Automatic Overset Grid Generation with Heuristic Feedback Control

    NASA Technical Reports Server (NTRS)

    Robinson, Peter I.

    2001-01-01

    An advancing front grid generation system for structured Overset grids is presented which automatically modifies Overset structured surface grids and control lines until user-specified grid qualities are achieved. The system is demonstrated on two examples: the first refines a space shuttle fuselage control line until global truncation error is achieved; the second advances, from control lines, the space shuttle orbiter fuselage top and fuselage side surface grids until proper overlap is achieved. Surface grids are generated in minutes for complex geometries. The system is implemented as a heuristic feedback control (HFC) expert system which iteratively modifies the input specifications for Overset control line and surface grids. It is developed as an extension of modern control theory, production rules systems and subsumption architectures. The methodology provides benefits over the full knowledge lifecycle of an expert system for knowledge acquisition, knowledge representation, and knowledge execution. The vector/matrix framework of modern control theory systematically acquires and represents expert system knowledge. Missing matrix elements imply missing expert knowledge. The execution of the expert system knowledge is performed through symbolic execution of the matrix algebra equations of modern control theory. The dot product operation of matrix algebra is generalized for heuristic symbolic terms. Constant time execution is guaranteed.

  1. A heuristic model of stone comminution in shock wave lithotripsy

    PubMed Central

    Smith, Nathan B.; Zhong, Pei

    2013-01-01

    A heuristic model is presented to describe the overall progression of stone comminution in shock wave lithotripsy (SWL), accounting for the effects of shock wave dose and the average peak pressure, P+(avg), incident on the stone during the treatment. The model is developed through adaptation of the Weibull theory for brittle fracture, incorporating threshold values in dose and P+(avg) that are required to initiate fragmentation. The model is validated against experimental data of stone comminution from two stone types (hard and soft BegoStone) obtained at various positions in lithotripter fields produced by two shock wave sources of different beam width and pulse profile both in water and in 1,3-butanediol (which suppresses cavitation). Subsequently, the model is used to assess the performance of a newly developed acoustic lens for electromagnetic lithotripters in comparison with its original counterpart both under static and simulated respiratory motion. The results have demonstrated the predictive value of this heuristic model in elucidating the physical basis for improved performance of the new lens. The model also provides a rationale for the selection of SWL treatment protocols to achieve effective stone comminution without elevating the risk of tissue injury. PMID:23927195

  2. A heuristic for efficient data distribution management in distributed simulation

    NASA Astrophysics Data System (ADS)

    Gupta, Pankaj; Guha, Ratan K.

    2005-05-01

    In this paper, we propose an algorithm for reducing the complexity of region matching and efficient multicasting in data distribution management component of High Level Architecture (HLA) Run Time Infrastructure (RTI). The current data distribution management (DDM) techniques rely on computing the intersection between the subscription and update regions. When a subscription region and an update region of different federates overlap, RTI establishes communication between the publisher and the subscriber. It subsequently routes the updates from the publisher to the subscriber. The proposed algorithm computes the update/subscription regions matching for dynamic allocation of multicast group. It provides new multicast routines that exploit the connectivity of federation by communicating updates regarding interactions and routes information only to those federates that require them. The region-matching problem in DDM reduces to clique-covering problem using the connections graph abstraction where the federations represent the vertices and the update/subscribe relations represent the edges. We develop an abstract model based on connection graph for data distribution management. Using this abstract model, we propose a heuristic for solving the region-matching problem of DDM. We also provide complexity analysis of the proposed heuristics.

  3. GYutsis: heuristic based calculation of general recoupling coefficients

    NASA Astrophysics Data System (ADS)

    Van Dyck, D.; Fack, V.

    2003-08-01

    General angular momentum recoupling coefficients can be expressed as a summation formula over products of 6- j coefficients. Yutsis, Levinson and Vanagas developed graphical techniques for representing the general recoupling coefficient as a cubic graph and they describe a set of reduction rules allowing a stepwise generation of the corresponding summation formula. This paper is a follow up to [Van Dyck and Fack, Comput. Phys. Comm. 151 (2003) 353-368] where we described a heuristic algorithm based on these techniques. In this article we separate the heuristic from the algorithm and describe some new heuristic approaches which can be plugged into the generic algorithm. We show that these new heuristics lead to good results: in many cases we get a more efficient summation formula than our previous approach, in particular for problems of higher order. In addition the new features and the use of our program GYutsis, which implements these techniques, is described both for end users and application programmers. Program summaryTitle of program: CycleCostAlgorithm, GYutsis Catalogue number: ADSA Program Summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSA Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland. Users may obtain the program also by downloading either the compressed tar file gyutsis.tgz (for Unix and Linux) or the zip file gyutsis.zip (for Windows) from our website ( http://caagt.rug.ac.be/yutsis/). An applet version of the program is also available on our website and can be run in a web browser from the URL http://caagt.rug.ac.be/yutsis/GYutsisApplet.html. Licensing provisions: none Computers for which the program is designed: any computer with Sun's Java Runtime Environment 1.4 or higher installed. Programming language used: Java 1.2 (Compiler: Sun's SDK 1.4.0) No. of lines in program: approximately 9400 No. of bytes in distributed program, including test data, etc.: 544 117 Distribution format: tar gzip file Nature of

  4. Avoiding reification. Heuristic effectiveness of mathematics and the prediction of the Ω- particle

    NASA Astrophysics Data System (ADS)

    Ginammi, Michele

    2016-02-01

    According to Steiner (1998), in contemporary physics new important discoveries are often obtained by means of strategies which rely on purely formal mathematical considerations. In such discoveries, mathematics seems to have a peculiar and controversial role, which apparently cannot be accounted for by means of standard methodological criteria. M. Gell-Mann and Y. Ne'eman's prediction of the Ω- particle is usually considered a typical example of application of this kind of strategy. According to Bangu (2008), this prediction is apparently based on the employment of a highly controversial principle-what he calls the "reification principle". Bangu himself takes this principle to be methodologically unjustifiable, but still indispensable to make the prediction logically sound. In the present paper I will offer a new reconstruction of the reasoning that led to this prediction. By means of this reconstruction, I will show that we do not need to postulate any "reificatory" role of mathematics in contemporary physics and I will contextually clarify the representative and heuristic role of mathematics in science.

  5. An Action Dependent Heuristic Dynamic Programming-controlled Superconducting Magnetic Energy Storage for Transient Stability Augmentation

    NASA Astrophysics Data System (ADS)

    Wang, Xinpu; Yang, Jun; Zhang, Xiaodong; Yu, Xiaopeng

    To enhance the stability of power system, the active power and reactive power can be absorbed from or released to Superconducting magnetic energy storage (SMES) unit according to system power requirements. This paper proposes a control strategy based on action dependent heuristic dynamic programing (ADHDP) which can control SMES to improve the stability of electric power system with on-line learning ability. Based on back propagation (BP) neural network, ADHDP approximates the optimal control solution of nonlinear system through iteration step by step. This on-line learning ability improves its performance by learning from its own mistakes through reinforcement signal from external environment, so that it can adjust the neural network weights according to the back propagation error to achieve optimal control performance. To investigate the effectiveness of the proposed control strategy, simulation tests are carried out in Matlab/Simulink. And a conventional Proportional-Integral (PI) controlled method is used to compare the performance of ADHDP. Simulation results show that the proposed controller demonstrates superior damping performance on power system oscillation caused by three-phase fault and wind power fluctuation over the PI controller.

  6. A Model and Heuristic for Solving Very Large Item Selection Problems.

    ERIC Educational Resources Information Center

    Swanson, Len; Stocking, Martha L.

    1993-01-01

    A model for solving very large item selection problems is presented. The model builds on binary programming applied to test construction. A heuristic for selecting items that satisfy the constraints in the model is also presented, and various problems are solved using the model and heuristic. (SLD)

  7. Heuristic Reasoning and Beliefs on Immigration: An Approach to an Intercultural Education Programme

    ERIC Educational Resources Information Center

    Navarro, Santiago Palacios; Lopez de Arechavaleta, Blanca Olalde

    2010-01-01

    People use mental shortcuts to simplify the amount of information they receive from the environment. Heuristic reasoning can be included among these mental shortcuts. In general, heuristics is useful for making fast decisions and judgements, but in certain cases, it may lead to systematic errors because some relevant aspects presented in the given…

  8. Structuring Decisions: The Role of Structuring Heuristics. Final Report. Technical Report 542.

    ERIC Educational Resources Information Center

    Humphreys, Patrick; And Others

    This paper discusses the incorporation of heuristics in computerized decision aids that are used for structuring decision problems. Decision theory is described in terms of linked subsystems, and sites where it is necessary to employ heuristic rather than normative, algorithmic procedures are identified. Production systems are then used to…

  9. Managing Heuristics as a Method of Inquiry in Autobiographical Graphic Design Theses

    ERIC Educational Resources Information Center

    Ings, Welby

    2011-01-01

    This article draws on case studies undertaken in postgraduate research at AUT University, Auckland. It seeks to address a number of issues related to heuristic inquiries employed by graphic design students who use autobiographical approaches when developing research-based theses. For this type of thesis, heuristics as a system of inquiry may…

  10. Heuristic algorithms for constructing optimized structures of linear multihop lightwave networks

    NASA Astrophysics Data System (ADS)

    Banerjee, Subrata; Mukherjee, Biswanath; Sarkar, Dillip

    1994-02-01

    We propose to exploit the capabilities of emerging lightwave technology in order to construct photonic implementations of 'adaptive' and 'optimized' distributed queue dual bus (DQDB) structures. Two sets of heuristic optimization algorithms are formulated. The performance of these heuristics are compared, some of their properties are analyzed, while their other attractive properties are highlighted via numerical examples.

  11. Social Outcomes in Childhood Brain Disorder: A Heuristic Integration of Social Neuroscience and Developmental Psychology

    ERIC Educational Resources Information Center

    Yeates, Keith Owen; Bigler, Erin D.; Dennis, Maureen; Gerhardt, Cynthia A.; Rubin, Kenneth H.; Stancin, Terry; Taylor, H. Gerry; Vannatta, Kathryn

    2007-01-01

    The authors propose a heuristic model of the social outcomes of childhood brain disorder that draws on models and methods from both the emerging field of social cognitive neuroscience and the study of social competence in developmental psychology/psychopathology. The heuristic model characterizes the relationships between social adjustment, peer…

  12. Using Heuristic Task Analysis to Create Web-Based Instructional Design Theory

    ERIC Educational Resources Information Center

    Fiester, Herbert R.

    2010-01-01

    The first purpose of this study was to identify procedural and heuristic knowledge used when creating web-based instruction. The second purpose of this study was to develop suggestions for improving the Heuristic Task Analysis process, a technique for eliciting, analyzing, and representing expertise in cognitively complex tasks. Three expert…

  13. Effects of Narrated Heuristic Feedback and Gender on College Students' Calculus Problem Solving Performance

    ERIC Educational Resources Information Center

    Xie, Ying; Coffland, David; Yang, Fangyun

    2012-01-01

    Multimodal feedback could promote college students' conceptual, procedural and heuristic knowledge learning. This study used an experimental design to investigate the interaction effects of instructor's narrated feedback (with procedural feedback delivered visually and heuristic feedback auditorily) and gender on their post-test performance of a…

  14. A Behavior Analysis of Individuals' Use of the Fairness Heuristic when Interacting with Groups and Organizations

    ERIC Educational Resources Information Center

    Goltz, Sonia M.

    2013-01-01

    In the present analysis the author utilizes the groups as patches model (Goltz, 2009, 2010) to extend fairness heuristic theory (Lind, 2001) in which the concept of fairness is thought to be a heuristic that allows individuals to match responses to consequences they receive from groups. In this model, individuals who are reviewing possible groups…

  15. A near-optimal heuristic for minimum weight triangulation of convex polygons

    SciTech Connect

    Levcopoulos, C.; Krznaric, D.

    1997-06-01

    A linear-time heuristic for minimum weight triangulation of convex polygons is presented. This heuristic produces a triangulation of length within a factor 1 + {epsilon} from the optimum, where {epsilon} is an arbitrarily small positive constant. This is the first sub-cubic algorithm which guarantees such an approximation factor, and it has interesting applications.

  16. Towards an Understanding of Instructional Design Heuristics: An Exploratory Delphi Study

    ERIC Educational Resources Information Center

    York, Cindy S.; Ertmer, Peggy A.

    2011-01-01

    Evidence suggests that experienced instructional designers often use heuristics and adapted models when engaged in the instructional design problem-solving process. This study used the Delphi technique to identify a core set of heuristics designers reported as being important to the success of the design process. The overarching purpose of the…

  17. Estimation of Post-Test Probabilities by Residents: Bayesian Reasoning versus Heuristics?

    ERIC Educational Resources Information Center

    Hall, Stacey; Phang, Sen Han; Schaefer, Jeffrey P.; Ghali, William; Wright, Bruce; McLaughlin, Kevin

    2014-01-01

    Although the process of diagnosing invariably begins with a heuristic, we encourage our learners to support their diagnoses by analytical cognitive processes, such as Bayesian reasoning, in an attempt to mitigate the effects of heuristics on diagnosing. There are, however, limited data on the use ± impact of Bayesian reasoning on the accuracy of…

  18. The Generation and Resemblance Heuristics in Face Recognition: Cooperation and Competition

    ERIC Educational Resources Information Center

    Kleider, Heather M.; Goldinger, Stephen D.

    2006-01-01

    Like all probabilistic decisions, recognition memory judgments are based on inferences about the strength and quality of stimulus familiarity. In recent articles, B. W. A. Whittlesea and J. Leboe (2000; J. Leboe & B. W. A. Whittlesea, 2002) proposed that such memory decisions entail various heuristics, similar to well-known heuristics in overt…

  19. Answer first: Applying the heuristic-analytic theory of reasoning to examine student intuitive thinking in the context of physics

    NASA Astrophysics Data System (ADS)

    Kryjevskaia, Mila; Stetzer, MacKenzie R.; Grosz, Nathaniel

    2014-12-01

    We have applied the heuristic-analytic theory of reasoning to interpret inconsistencies in student reasoning approaches to physics problems. This study was motivated by an emerging body of evidence that suggests that student conceptual and reasoning competence demonstrated on one task often fails to be exhibited on another. Indeed, even after instruction specifically designed to address student conceptual and reasoning difficulties identified by rigorous research, many undergraduate physics students fail to build reasoning chains from fundamental principles even though they possess the required knowledge and skills to do so. Instead, they often rely on a variety of intuitive reasoning strategies. In this study, we developed and employed a methodology that allowed for the disentanglement of student conceptual understanding and reasoning approaches through the use of sequences of related questions. We have shown that the heuristic-analytic theory of reasoning can be used to account for, in a mechanistic fashion, the observed inconsistencies in student responses. In particular, we found that students tended to apply their correct ideas in a selective manner that supported a specific and likely anticipated conclusion while neglecting to employ the same ideas to refute an erroneous intuitive conclusion. The observed reasoning patterns were consistent with the heuristic-analytic theory, according to which reasoners develop a "first-impression" mental model and then construct an argument in support of the answer suggested by this model. We discuss implications for instruction and argue that efforts to improve student metacognition, which serves to regulate the interaction between intuitive and analytical reasoning, is likely to lead to improved student reasoning.

  20. Combination of graph heuristics in producing initial solution of curriculum based course timetabling problem

    NASA Astrophysics Data System (ADS)

    Wahid, Juliana; Hussin, Naimah Mohd

    2016-08-01

    The construction of population of initial solution is a crucial task in population-based metaheuristic approach for solving curriculum-based university course timetabling problem because it can affect the convergence speed and also the quality of the final solution. This paper presents an exploration on combination of graph heuristics in construction approach in curriculum based course timetabling problem to produce a population of initial solutions. The graph heuristics were set as single and combination of two heuristics. In addition, several ways of assigning courses into room and timeslot are implemented. All settings of heuristics are then tested on the same curriculum based course timetabling problem instances and are compared with each other in terms of number of population produced. The result shows that combination of saturation degree followed by largest degree heuristic produce the highest number of population of initial solutions. The results from this study can be used in the improvement phase of algorithm that uses population of initial solutions.

  1. Usability Heuristics and Qualitative Indicators for the Usability Evaluation of Touch Screen Ventilator Systems

    NASA Astrophysics Data System (ADS)

    Katre, Dinesh; Bhutkar, Ganesh; Karmarkar, Shekhar

    A ventilator system provides respiratory support to critically ill patients in the Intensive Care Unit. Increasing complexity in the user interface, features and functionalities of ventilator systems can cause medical errors and cost the life of a patient. Therefore, the usability of ventilator systems is most crucial to ensure patient safety. We have evolved a specialized set of heuristics combined with objectively defined usability indicators for the usability evaluation of touch screen based ventilator systems. Our study presents the heuristic evaluation of three touch screen based ventilator systems manufactured by three different companies. The heuristic evaluation has been performed by four different usability evaluators to ensure the reliability of heuristics proposed in this paper. The specialized set of heuristics linked with user interface components and the objectively defined usability indicators are found more reliable in identifying specific usability problems of ventilator systems.

  2. Combining factual and heuristic knowledge in knowledge acquisition

    NASA Technical Reports Server (NTRS)

    Gomez, Fernando; Hull, Richard; Karr, Clark; Hosken, Bruce; Verhagen, William

    1992-01-01

    A knowledge acquisition technique that combines heuristic and factual knowledge represented as two hierarchies is described. These ideas were applied to the construction of a knowledge acquisition interface to the Expert System Analyst (OPERA). The goal of OPERA is to improve the operations support of the computer network in the space shuttle launch processing system. The knowledge acquisition bottleneck lies in gathering knowledge from human experts and transferring it to OPERA. OPERA's knowledge acquisition problem is approached as a classification problem-solving task, combining this approach with the use of factual knowledge about the domain. The interface was implemented in a Symbolics workstation making heavy use of windows, pull-down menus, and other user-friendly devices.

  3. A comparison of heuristic search algorithms for molecular docking.

    PubMed

    Westhead, D R; Clark, D E; Murray, C W

    1997-05-01

    This paper describes the implementation and comparison of four heuristic search algorithms (genetic algorithm, evolutionary programming, simulated annealing and tabu search) and a random search procedure for flexible molecular docking. To our knowledge, this is the first application of the tabu search algorithm in this area. The algorithms are compared using a recently described fast molecular recognition potential function and a diverse set of five protein-ligand systems. Statistical analysis of the results indicates that overall the genetic algorithm performs best in terms of the median energy of the solutions located. However, tabu search shows a better performance in terms of locating solutions close to the crystallographic ligand conformation. These results suggest that a hybrid search algorithm may give superior results to any of the algorithms alone. PMID:9263849

  4. A Heuristic Framework to Solve a General Delivery Problem

    NASA Astrophysics Data System (ADS)

    Lian, Lian; Castelain, Emmanuel

    2010-06-01

    This paper presents a new distribution and route planning problem, General Delivery Problem (GDP) which is more general than the well-known Vehicle Routing Problem. To solve a GDP, a three-phase framework heuristic approach based on decomposition techniques is introduced. The decomposition techniques are employed to divide an original problem into a set of sub-problems, which can reduce the problem size. A kind of decomposition technique, Capacity Clustering Algorithm (CCA), is embedded into the framework with Simulated Annealing (SA) to solve a special GDP. The proposed three-phase framework with the above two algorithms is compared with five other decomposition methods in a distribution instance of the Regional Fire and Emergency Center in the north of France.

  5. Heuristic reusable dynamic programming: efficient updates of local sequence alignment.

    PubMed

    Hong, Changjin; Tewfik, Ahmed H

    2009-01-01

    Recomputation of the previously evaluated similarity results between biological sequences becomes inevitable when researchers realize errors in their sequenced data or when the researchers have to compare nearly similar sequences, e.g., in a family of proteins. We present an efficient scheme for updating local sequence alignments with an affine gap model. In principle, using the previous matching result between two amino acid sequences, we perform a forward-backward alignment to generate heuristic searching bands which are bounded by a set of suboptimal paths. Given a correctly updated sequence, we initially predict a new score of the alignment path for each contour to select the best candidates among them. Then, we run the Smith-Waterman algorithm in this confined space. Furthermore, our heuristic alignment for an updated sequence shows that it can be further accelerated by using reusable dynamic programming (rDP), our prior work. In this study, we successfully validate "relative node tolerance bound" (RNTB) in the pruned searching space. Furthermore, we improve the computational performance by quantifying the successful RNTB tolerance probability and switch to rDP on perturbation-resilient columns only. In our searching space derived by a threshold value of 90 percent of the optimal alignment score, we find that 98.3 percent of contours contain correctly updated paths. We also find that our method consumes only 25.36 percent of the runtime cost of sparse dynamic programming (sDP) method, and to only 2.55 percent of that of a normal dynamic programming with the Smith-Waterman algorithm. PMID:19875856

  6. Heuristic modeling of macromolecule release from PLGA microspheres.

    PubMed

    Szlęk, Jakub; Pacławski, Adam; Lau, Raymond; Jachowicz, Renata; Mendyk, Aleksander

    2013-01-01

    Dissolution of protein macromolecules from poly(lactic-co-glycolic acid) (PLGA) particles is a complex process and still not fully understood. As such, there are difficulties in obtaining a predictive model that could be of fundamental significance in design, development, and optimization for medical applications and toxicity evaluation of PLGA-based multiparticulate dosage form. In the present study, two models with comparable goodness of fit were proposed for the prediction of the macromolecule dissolution profile from PLGA micro- and nanoparticles. In both cases, heuristic techniques, such as artificial neural networks (ANNs), feature selection, and genetic programming were employed. Feature selection provided by fscaret package and sensitivity analysis performed by ANNs reduced the original input vector from a total of 300 input variables to 21, 17, 16, and eleven; to achieve a better insight into generalization error, two cut-off points for every method was proposed. The best ANNs model results were obtained by monotone multi-layer perceptron neural network (MON-MLP) networks with a root-mean-square error (RMSE) of 15.4, and the input vector consisted of eleven inputs. The complicated classical equation derived from a database consisting of 17 inputs was able to yield a better generalization error (RMSE) of 14.3. The equation was characterized by four parameters, thus feasible (applicable) to standard nonlinear regression techniques. Heuristic modeling led to the ANN model describing macromolecules release profiles from PLGA microspheres with good predictive efficiency. Moreover genetic programming technique resulted in classical equation with comparable predictability to the ANN model. PMID:24348037

  7. Identification of structural domains in proteins by a graph heuristic.

    PubMed

    Wernisch, L; Hunting, M; Wodak, S J

    1999-05-15

    A novel automatic procedure for identifying domains from protein atomic coordinates is presented. The procedure, termed STRUDL (STRUctural Domain Limits), does not take into account information on secondary structures and handles any number of domains made up of contiguous or non-contiguous chain segments. The core algorithm uses the Kernighan-Lin graph heuristic to partition the protein into residue sets which display minimum interactions between them. These interactions are deduced from the weighted Voronoi diagram. The generated partitions are accepted or rejected on the basis of optimized criteria, representing basic expected physical properties of structural domains. The graph heuristic approach is shown to be very effective, it approximates closely the exact solution provided by a branch and bound algorithm for a number of test proteins. In addition, the overall performance of STRUDL is assessed on a set of 787 representative proteins from the Protein Data Bank by comparison to domain definitions in the CATH protein classification. The domains assigned by STRUDL agree with the CATH assignments in at least 81% of the tested proteins. This result is comparable to that obtained previously using PUU (Holm and Sander, Proteins 1994;9:256-268), the only other available algorithm designed to identify domains with any number of non-contiguous chain segments. A detailed discussion of the structures for which our assignments differ from those in CATH brings to light some clear inconsistencies between the concept of structural domains based on minimizing inter-domain interactions and that of delimiting structural motifs that represent acceptable folding topologies or architectures. Considering both concepts as complementary and combining them in a layered approach might be the way forward. PMID:10328269

  8. Heuristic modeling of macromolecule release from PLGA microspheres

    PubMed Central

    Szlęk, Jakub; Pacławski, Adam; Lau, Raymond; Jachowicz, Renata; Mendyk, Aleksander

    2013-01-01

    Dissolution of protein macromolecules from poly(lactic-co-glycolic acid) (PLGA) particles is a complex process and still not fully understood. As such, there are difficulties in obtaining a predictive model that could be of fundamental significance in design, development, and optimization for medical applications and toxicity evaluation of PLGA-based multiparticulate dosage form. In the present study, two models with comparable goodness of fit were proposed for the prediction of the macromolecule dissolution profile from PLGA micro- and nanoparticles. In both cases, heuristic techniques, such as artificial neural networks (ANNs), feature selection, and genetic programming were employed. Feature selection provided by fscaret package and sensitivity analysis performed by ANNs reduced the original input vector from a total of 300 input variables to 21, 17, 16, and eleven; to achieve a better insight into generalization error, two cut-off points for every method was proposed. The best ANNs model results were obtained by monotone multi-layer perceptron neural network (MON-MLP) networks with a root-mean-square error (RMSE) of 15.4, and the input vector consisted of eleven inputs. The complicated classical equation derived from a database consisting of 17 inputs was able to yield a better generalization error (RMSE) of 14.3. The equation was characterized by four parameters, thus feasible (applicable) to standard nonlinear regression techniques. Heuristic modeling led to the ANN model describing macromolecules release profiles from PLGA microspheres with good predictive efficiency. Moreover genetic programming technique resulted in classical equation with comparable predictability to the ANN model. PMID:24348037

  9. Conceptual space Systems Design using Meta-Heuristic Algorithms

    NASA Astrophysics Data System (ADS)

    Kim, Byoungsoo; Morgenthaler, George W.

    2002-01-01

    easily and explicitly by new design-to-cost philosophy, "faster, better, cheaper" (fast-track, innovative, lower-cost, small-sat). The objective of the Space Systems Design has moved from maximizing space mission performance under weak time and cost constraints (almost regardless of cost) but with technology risk constraints, to maximizing mission goals under cost and schedule constraints but with prudent technology risk constraints, or maximizing space mission performance per unit cost. Within this mindset, Conceptual Space Systems Design models were formulated as constrained combinatorial optimization problems with estimated Total Mission Cost (TMC) as its objective function to be minimized and subsystems trade-offs as decision variables in its design space, using parametric estimating relationships (PERs) and cost estimating relationships (CERs).Here a constrained combinatorial optimized "solution" is defined as achieving the most favorable alternative for the system on the basis of the decision-making design criteria. Two non-traditional meta-heuristic optimization algorithms, Genetic Algorithms (GAs) and Simulated Annealing (SA), were used to solve the formulated combinatorial optimization model for the Conceptual Space Systems Design. GAs and SA were demonstrated on SAMPEX. The model simulation statistics show that the estimated TMCs obtained by GAs and SA are statistically equal and consistent. These statistics also show that Conceptual Space Systems Design Model can be used as a guidance tool to evaluate and validate space research proposals. Also, the non-traditional meta-heuristic constrained optimization techniques, GAs and SA, can be applied to all manner of space, civil or commercial design problems.

  10. Use of Heuristics to Facilitate Scientific Discovery Learning in a Simulation Learning Environment in a Physics Domain

    ERIC Educational Resources Information Center

    Veermans, Koen; van Joolingen, Wouter; de Jong, Ton

    2006-01-01

    This article describes a study into the role of heuristic support in facilitating discovery learning through simulation-based learning. The study compares the use of two such learning environments in the physics domain of collisions. In one learning environment (implicit heuristics) heuristics are only used to provide the learner with guidance…

  11. Communication patterns and allocation strategies.

    SciTech Connect

    Leung, Vitus Joseph; Mache, Jens Wolfgang; Bunde, David P.

    2004-01-01

    Motivated by observations about job runtimes on the CPlant system, we use a trace-driven microsimulator to begin characterizing the performance of different classes of allocation algorithms on jobs with different communication patterns in space-shared parallel systems with mesh topology. We show that relative performance varies considerably with communication pattern. The Paging strategy using the Hilbert space-filling curve and the Best Fit heuristic performed best across several communication patterns.

  12. Scalable Heuristics for Planning, Placement and Sizing of Flexible AC Transmission System Devices

    SciTech Connect

    Frolov, Vladmir; Backhaus, Scott N.; Chertkov, Michael

    2015-07-02

    Aiming to relieve transmission grid congestion and improve or extend feasibility domain of the operations, we build optimization heuristics, generalizing standard AC Optimal Power Flow (OPF), for placement and sizing of Flexible Alternating Current Transmission System (FACTS) devices of the Series Compensation (SC) and Static VAR Compensation (SVC) type. One use of these devices is in resolving the case when the AC OPF solution does not exist because of congestion. Another application is developing a long-term investment strategy for placement and sizing of the SC and SVC devices to reduce operational cost and improve power system operation. SC and SVC devices are represented by modification of the transmission line inductances and reactive power nodal corrections respectively. We find one placement and sizing of FACTs devices for multiple scenarios and optimal settings for each scenario simultaneously. Our solution of the nonlinear and nonconvex generalized AC-OPF consists of building a convergent sequence of convex optimizations containing only linear constraints and shows good computational scaling to larger systems. The approach is illustrated on single- and multi-scenario examples of the Matpower case-30 model.

  13. Decision precision or holistic heuristic?: Insights on on-site selection of student nurses and midwives.

    PubMed

    Macduff, Colin; Stephen, Audrey; Taylor, Ruth

    2016-01-01

    Concerns about quality of care delivery in the UK have led to more scrutiny of criteria and methods for the selection of student nurses. However few substantive research studies of on-site selection processes exist. This study elicited and interpreted perspectives on interviewing processes and related decision making involved in on-site selection of student nurses and midwives. Individual and focus group interviews were undertaken with 36 lecturers, 5 clinical staff and 72 students from seven Scottish universities. Enquiry focused primarily on interviewing of candidates on-site. Qualitative content analysis was used as a primary strategy, followed by in-depth thematic analysis. Students had very mixed experiences of interview processes. Staff typically took into account a range of candidate attributes that they valued in order to achieve holistic assessments. These included: interpersonal skills, team working, confidence, problem-solving, aptitude for caring, motivations, and commitment. Staff had mixed views of the validity and reliability of interview processes. A holistic heuristic for overall decision making predominated over belief in the precision of, and evidence base for, particular attribute measurement processes. While the development of measurement tools for particular attributes continues apace, tension between holism and precision is likely to persist within on-site selection procedures. PMID:26213147

  14. Heuristics guide the implementation of social preferences in one-shot Prisoner's Dilemma experiments.

    PubMed

    Capraro, Valerio; Jordan, Jillian J; Rand, David G

    2014-01-01

    Cooperation in one-shot anonymous interactions is a widely documented aspect of human behaviour. Here we shed light on the motivations behind this behaviour by experimentally exploring cooperation in a one-shot continuous-strategy Prisoner's Dilemma (i.e. one-shot two-player Public Goods Game). We examine the distribution of cooperation amounts, and how that distribution varies based on the benefit-to-cost ratio of cooperation (b/c). Interestingly, we find a trimodal distribution at all b/c values investigated. Increasing b/c decreases the fraction of participants engaging in zero cooperation and increases the fraction engaging in maximal cooperation, suggesting a role for efficiency concerns. However, a substantial fraction of participants consistently engage in 50% cooperation regardless of b/c. The presence of these persistent 50% cooperators is surprising, and not easily explained by standard models of social preferences. We present evidence that this behaviour is a result of social preferences guided by simple decision heuristics, rather than the rational examination of payoffs assumed by most social preference models. We also find a strong correlation between play in the Prisoner's Dilemma and in a subsequent Dictator Game, confirming previous findings suggesting a common prosocial motivation underlying altruism and cooperation. PMID:25348470

  15. Parameter Identification of Robot Manipulators: A Heuristic Particle Swarm Search Approach

    PubMed Central

    Yan, Danping; Lu, Yongzhong; Levy, David

    2015-01-01

    Parameter identification of robot manipulators is an indispensable pivotal process of achieving accurate dynamic robot models. Since these kinetic models are highly nonlinear, it is not easy to tackle the matter of identifying their parameters. To solve the difficulty effectively, we herewith present an intelligent approach, namely, a heuristic particle swarm optimization (PSO) algorithm, which we call the elitist learning strategy (ELS) and proportional integral derivative (PID) controller hybridized PSO approach (ELPIDSO). A specified PID controller is designed to improve particles’ local and global positions information together with ELS. Parameter identification of robot manipulators is conducted for performance evaluation of our proposed approach. Experimental results clearly indicate the following findings: Compared with standard PSO (SPSO) algorithm, ELPIDSO has improved a lot. It not only enhances the diversity of the swarm, but also features better search effectiveness and efficiency in solving practical optimization problems. Accordingly, ELPIDSO is superior to least squares (LS) method, genetic algorithm (GA), and SPSO algorithm in estimating the parameters of the kinetic models of robot manipulators. PMID:26039090

  16. Parameter identification of robot manipulators: a heuristic particle swarm search approach.

    PubMed

    Yan, Danping; Lu, Yongzhong; Levy, David

    2015-01-01

    Parameter identification of robot manipulators is an indispensable pivotal process of achieving accurate dynamic robot models. Since these kinetic models are highly nonlinear, it is not easy to tackle the matter of identifying their parameters. To solve the difficulty effectively, we herewith present an intelligent approach, namely, a heuristic particle swarm optimization (PSO) algorithm, which we call the elitist learning strategy (ELS) and proportional integral derivative (PID) controller hybridized PSO approach (ELPIDSO). A specified PID controller is designed to improve particles' local and global positions information together with ELS. Parameter identification of robot manipulators is conducted for performance evaluation of our proposed approach. Experimental results clearly indicate the following findings: Compared with standard PSO (SPSO) algorithm, ELPIDSO has improved a lot. It not only enhances the diversity of the swarm, but also features better search effectiveness and efficiency in solving practical optimization problems. Accordingly, ELPIDSO is superior to least squares (LS) method, genetic algorithm (GA), and SPSO algorithm in estimating the parameters of the kinetic models of robot manipulators. PMID:26039090

  17. Making decisions at the end of life when caring for a person with dementia: a literature review to explore the potential use of heuristics in difficult decision-making

    PubMed Central

    Mathew, R; Davies, N; Manthorpe, J; Iliffe, S

    2016-01-01

    Objective Decision-making, when providing care and treatment for a person with dementia at the end of life, can be complex and challenging. There is a lack of guidance available to support practitioners and family carers, and even those experienced in end of life dementia care report a lack of confidence in decision-making. It is thought that the use of heuristics (rules of thumb) may aid decision-making. The aim of this study is to identify whether heuristics are used in end of life dementia care, and if so, to identify the context in which they are being used. Design A narrative literature review was conducted taking a systematic approach to the search strategy, using the Centre for Reviews and Dissemination guidelines. Rapid appraisal methodology was used in order to source specific and relevant literature regarding the use of heuristics in end of life dementia care. Data sources A search using terms related to dementia, palliative care and decision-making was conducted across 4 English language electronic databases (MEDLINE, EMBASE, PsycINFO and CINAHL) in 2015. Results The search identified 12 papers that contained an algorithm, guideline, decision tool or set of principles that we considered compatible with heuristic decision-making. The papers addressed swallowing and feeding difficulties, the treatment of pneumonia, management of pain and agitation, rationalising medication, ending life-sustaining treatment, and ensuring a good death. Conclusions The use of heuristics in palliative or end of life dementia care is not described in the research literature. However, this review identified important decision-making principles, which are largely a reflection of expert opinion. These principles may have the potential to be developed into simple heuristics that could be used in practice. PMID:27436665

  18. A multi-stage heuristic algorithm for matching problem in the modified miniload automated storage and retrieval system of e-commerce

    NASA Astrophysics Data System (ADS)

    Wang, Wenrui; Wu, Yaohua; Wu, Yingying

    2016-05-01

    E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

  19. A multi-stage heuristic algorithm for matching problem in the modified miniload automated storage and retrieval system of e-commerce

    NASA Astrophysics Data System (ADS)

    Wang, Wenrui; Wu, Yaohua; Wu, Yingying

    2016-04-01

    E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

  20. Design of high-performing hybrid meta-heuristics for unrelated parallel machine scheduling with machine eligibility and precedence constraints

    NASA Astrophysics Data System (ADS)

    Afzalirad, Mojtaba; Rezaeian, Javad

    2016-04-01

    This study involves an unrelated parallel machine scheduling problem in which sequence-dependent set-up times, different release dates, machine eligibility and precedence constraints are considered to minimize total late works. A new mixed-integer programming model is presented and two efficient hybrid meta-heuristics, genetic algorithm and ant colony optimization, combined with the acceptance strategy of the simulated annealing algorithm (Metropolis acceptance rule), are proposed to solve this problem. Manifestly, the precedence constraints greatly increase the complexity of the scheduling problem to generate feasible solutions, especially in a parallel machine environment. In this research, a new corrective algorithm is proposed to obtain the feasibility in all stages of the algorithms. The performance of the proposed algorithms is evaluated in numerical examples. The results indicate that the suggested hybrid ant colony optimization statistically outperformed the proposed hybrid genetic algorithm in solving large-size test problems.

  1. Social welfare as small-scale help: evolutionary psychology and the deservingness heuristic.

    PubMed

    Petersen, Michael Bang

    2012-01-01

    Public opinion concerning social welfare is largely driven by perceptions of recipient deservingness. Extant research has argued that this heuristic is learned from a variety of cultural, institutional, and ideological sources. The present article provides evidence supporting a different view: that the deservingness heuristic is rooted in psychological categories that evolved over the course of human evolution to regulate small-scale exchanges of help. To test predictions made on the basis of this view, a method designed to measure social categorization is embedded in nationally representative surveys conducted in different countries. Across the national- and individual-level differences that extant research has used to explain the heuristic, people categorize welfare recipients on the basis of whether they are lazy or unlucky. This mode of categorization furthermore induces people to think about large-scale welfare politics as its presumed ancestral equivalent: small-scale help giving. The general implications for research on heuristics are discussed. PMID:22375300

  2. The White ceiling heuristic and the underestimation of Asian-American income.

    PubMed

    Martin, Chris C; Nezlek, John B

    2014-01-01

    The belief that ethnic majorities dominate ethnic minorities informs research on intergroup processes. This belief can lead to the social heuristic that the ethnic majority sets an upper limit that minority groups cannot surpass, but this possibility has not received much attention. In three studies of perceived income, we examined how this heuristic, which we term the White ceiling heuristic leads people to inaccurately estimate the income of a minority group that surpasses the majority. We found that Asian Americans, whose median income has surpassed White median income for nearly three decades, are still perceived as making less than Whites, with the least accurate estimations being made by people who strongly believe that Whites are privileged. In contrast, income estimates for other minorities were fairly accurate. Thus, perceptions of minorities are shaped both by stereotype content and a heuristic. PMID:25268366

  3. Optimization of pressurized water reactor shuffling by simulated annealing with heuristics

    SciTech Connect

    Stevens, J.G.; Smith, K.S.; Rempe, K.R.; Downar, T.J.

    1995-09-01

    Simulated-annealing optimization of reactor core loading patterns is implemented with support for design heuristics during candidate pattern generation. The SIMAN optimization module uses the advanced nodal method of SIMULATE-3 and the full cross-section detail of CASMO-3 to evaluate accurately the neutronic performance of each candidate, resulting in high-quality patterns. The use of heuristics within simulated annealing is explored. Heuristics improve the consistency of optimization results for both fast- and slow-annealing runs with no penalty from the exclusion of unusual candidates. Thus, the heuristic application of designer judgment during automated pattern generation is shown to be effective. The capability of the SIMAN module to find and evaluate families of loading patterns that satisfy design constraints and have good objective performance within practical run times is demonstrated. The use of automated evaluations of successive cycles to explore multicycle effects of design decisions is discussed.

  4. The White Ceiling Heuristic and the Underestimation of Asian-American Income

    PubMed Central

    Martin, Chris C.; Nezlek, John B.

    2014-01-01

    The belief that ethnic majorities dominate ethnic minorities informs research on intergroup processes. This belief can lead to the social heuristic that the ethnic majority sets an upper limit that minority groups cannot surpass, but this possibility has not received much attention. In three studies of perceived income, we examined how this heuristic, which we term the White ceiling heuristic leads people to inaccurately estimate the income of a minority group that surpasses the majority. We found that Asian Americans, whose median income has surpassed White median income for nearly three decades, are still perceived as making less than Whites, with the least accurate estimations being made by people who strongly believe that Whites are privileged. In contrast, income estimates for other minorities were fairly accurate. Thus, perceptions of minorities are shaped both by stereotype content and a heuristic. PMID:25268366

  5. Using the Science Writing Heuristic in the General Chemistry Laboratory to Improve Students' Academic Performance

    ERIC Educational Resources Information Center

    Poock, Jason R.; Burke, K. A.; Greenbowe, Thomas J.; Hand, Brian M.

    2007-01-01

    The analysis describes the effects of using the science writing heuristic (SWH) in the general chemistry laboratory on the students' academic performance. The technique has found to be extremely important factor in a student's learning process and achievement in science.

  6. Does interaction matter? Testing whether a confidence heuristic can replace interaction in collective decision-making.

    PubMed

    Bang, Dan; Fusaroli, Riccardo; Tylén, Kristian; Olsen, Karsten; Latham, Peter E; Lau, Jennifer Y F; Roepstorff, Andreas; Rees, Geraint; Frith, Chris D; Bahrami, Bahador

    2014-05-01

    In a range of contexts, individuals arrive at collective decisions by sharing confidence in their judgements. This tendency to evaluate the reliability of information by the confidence with which it is expressed has been termed the 'confidence heuristic'. We tested two ways of implementing the confidence heuristic in the context of a collective perceptual decision-making task: either directly, by opting for the judgement made with higher confidence, or indirectly, by opting for the faster judgement, exploiting an inverse correlation between confidence and reaction time. We found that the success of these heuristics depends on how similar individuals are in terms of the reliability of their judgements and, more importantly, that for dissimilar individuals such heuristics are dramatically inferior to interaction. Interaction allows individuals to alleviate, but not fully resolve, differences in the reliability of their judgements. We discuss the implications of these findings for models of confidence and collective decision-making. PMID:24650632

  7. Unified heuristics to solve routing problem of reverse logistics in sustainable supply chain

    NASA Astrophysics Data System (ADS)

    Anbuudayasankar, S. P.; Ganesh, K.; Lenny Koh, S. C.; Mohandas, K.

    2010-03-01

    A reverse logistics problem, motivated by many real-life applications, is examined where bottles/cans in which products are delivered from a processing depot to customers in one period are available for return to the depot in the following period. The picked-up bottles/cans need to be adjusted in the place of delivery load. This problem is termed as simultaneous delivery and pick-up problem with constrained capacity (SDPC). We develop three unified heuristics based on extended branch and bound heuristic, genetic algorithm and simulated annealing to solve SDPC. These heuristics are also designed to solve standard travelling salesman problem (TSP) and TSP with simultaneous delivery and pick-up (TSDP). We tested the heuristics on standard, derived and randomly generated datasets of TSP, TSDP and SDPC and obtained satisfying results with high convergence in reasonable time.

  8. Probabilistic dual heuristic programming-based adaptive critic

    NASA Astrophysics Data System (ADS)

    Herzallah, Randa

    2010-02-01

    Adaptive critic (AC) methods have common roots as generalisations of dynamic programming for neural reinforcement learning approaches. Since they approximate the dynamic programming solutions, they are potentially suitable for learning in noisy, non-linear and non-stationary environments. In this study, a novel probabilistic dual heuristic programming (DHP)-based AC controller is proposed. Distinct to current approaches, the proposed probabilistic (DHP) AC method takes uncertainties of forward model and inverse controller into consideration. Therefore, it is suitable for deterministic and stochastic control problems characterised by functional uncertainty. Theoretical development of the proposed method is validated by analytically evaluating the correct value of the cost function which satisfies the Bellman equation in a linear quadratic control problem. The target value of the probabilistic critic network is then calculated and shown to be equal to the analytically derived correct value. Full derivation of the Riccati solution for this non-standard stochastic linear quadratic control problem is also provided. Moreover, the performance of the proposed probabilistic controller is demonstrated on linear and non-linear control examples.

  9. Runway Operations Planning: A Two-Stage Heuristic Algorithm

    NASA Technical Reports Server (NTRS)

    Anagnostakis, Ioannis; Clarke, John-Paul

    2003-01-01

    The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, can also be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. This paper introduces a two stage heuristic algorithm for solving the Runway Operations Planning (ROP) problem. In the first stage, sequences of departure class slots and runway crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the departure class slots are populated with specific flights from the pool of available aircraft, by solving an integer program with a Branch & Bound algorithm implementation. Preliminary results from this implementation of the two-stage algorithm on real-world traffic data are presented.

  10. Farley Buneman wave heating: Confirming heuristics with radar observations

    NASA Astrophysics Data System (ADS)

    Miceli, R. J.; Hysell, D. L.; Munk, J.; Huba, J. D.

    2013-12-01

    Combined observations from the Poker Flat incoherent scatter radar (PFISR) and a 30 MHz coherent scatter radar in Homer, Alaska were made during geomagnetic storms in November 2012 and March 2013. Enhanced electron temperature and density in the E region were measured by the PFISR and strong echoes from field aligned irregularities were measured by the coherent scatter radar. We compare these observations with a heuristic model of Farley Buneman waves based on the formulations of Milikh and Dimant (2002) and the SAMI2 global model of the ionosphere. The model predicts phase speed and magnetic aspect width profiles, as well as profiles of ionospheric state variables as functions of the convective electric field. By accounting for the thickness of the region where Farley Buneman waves exist and weighting the profiles accordingly, the model is capable of estimating the phase velocity and magnetic aspect width that would be observed by a coherent scatter radar. We then use the comparison to assess the empirical relationships of coherent scatter radar observations of Farley Buneman waves.

  11. Geometry optimization of bimetallic clusters using an efficient heuristic method

    NASA Astrophysics Data System (ADS)

    Lai, Xiangjing; Xu, Ruchu; Huang, Wenqi

    2011-10-01

    In this paper, an efficient heuristic algorithm for geometry optimization of bimetallic clusters is proposed. The algorithm is mainly composed of three ingredients: the monotonic basin-hopping method with guided perturbation (MBH-GP), surface optimization method, and iterated local search (ILS) method, where MBH-GP and surface optimization method are used to optimize the geometric structure of a cluster, and the ILS method is used to search the optimal homotop for a fixed geometric structure. The proposed method is applied to Cu38-nAun (0 ≤ n ≤ 38), Ag55-nAun (0 ≤ n ≤ 55), and Cu55-nAun (0 ≤ n ≤ 55) clusters modeled by the many-body Gupta potential. Comparison with the results reported in the literature indicates that the present method is highly efficient and a number of new putative global minima missed in the previous papers are found. The present method should be a promising tool for the theoretical determination of ground-state structure of bimetallic clusters. Additionally, some key elements and properties of the present method are also analyzed.

  12. Using Heuristic Algorithms to Optimize Observing Target Sequences

    NASA Astrophysics Data System (ADS)

    Sosnowska, D.; Ouadahi, A.; Buchschacher, N.; Weber, L.; Pepe, F.

    2014-05-01

    The preparation of observations is normally carried out at the telescope by the visiting observer. In order to help the observer, we propose several algorithms to automatically optimize the sequence of targets. The optimization consists of assuring that all the chosen targets are observable within the given time interval, and to find their best execution order in terms of the observation quality and the shortest telescope displacement time. Since an exhaustive search is too expensive in time, we researched heuristic algorithms, specifically: Min-Conflict, Non-Sorting Genetic Algorithms and Simulated Annealing. Multiple metaheuristics are used in parallel to swiftly give an approximation of the best solution, with all the constraints satisfied and the total execution time minimized. The optimization process has a duration on the order of tens of seconds, allowing for quick re-adaptation in case of changing atmospheric conditions. The graphical user interface allows the user to control the parameters of the optimization process. Therefore, the search can be adjusted in real time. The module was coded in a way to allow easily the addition of new constraints, and thus ensure its compatibility with different instruments. For now, the application runs as a plug-in to the observation preparation tool called New Short Term Scheduler, which is used on three spectrographs dedicated to the exoplanets search: HARPS at the La Silla observatory, HARPS North at the La Palma observatory and SOPHIE at the Observatoire de Haute-Provence.

  13. Mixed Integer Programming and Heuristic Scheduling for Space Communication Networks

    NASA Technical Reports Server (NTRS)

    Cheung, Kar-Ming; Lee, Charles H.

    2012-01-01

    We developed framework and the mathematical formulation for optimizing communication network using mixed integer programming. The design yields a system that is much smaller, in search space size, when compared to the earlier approach. Our constrained network optimization takes into account the dynamics of link performance within the network along with mission and operation requirements. A unique penalty function is introduced to transform the mixed integer programming into the more manageable problem of searching in a continuous space. The constrained optimization problem was proposed to solve in two stages: first using the heuristic Particle Swarming Optimization algorithm to get a good initial starting point, and then feeding the result into the Sequential Quadratic Programming algorithm to achieve the final optimal schedule. We demonstrate the above planning and scheduling methodology with a scenario of 20 spacecraft and 3 ground stations of a Deep Space Network site. Our approach and framework have been simple and flexible so that problems with larger number of constraints and network can be easily adapted and solved.

  14. Formal versus heuristic modeling for multitarget Bayes filtering

    NASA Astrophysics Data System (ADS)

    Mahler, Ronald P. S.

    2004-08-01

    The multisensor-multitarget Bayes filter is the foundation for multi-sensor-multitarget detection, tracking, and identification. This paper addresses the question of principled implementation of this filter. Algorithms can always be cobbled together using catch-as-catch-can heuristic techniques. In formal Bayes modeling one instead derives statistically precise, implementation-independent equations from which principle approximations can then be derived. Indeed, this has become the accepted methodology for single-sensor, single-target tracking R&D. In the case of the multitarget filter, however, partisans of a so-called "plain-vanilla Bayesian approach" have disparaged formal Bayes modelling, and have protrayed specific, ad hoc implementations as completely general, "powerful and robust computational methods." In this and a companion paper I expose the speciousness of such claims. This paper reviews the elements of formal Bayes modeling and approximation, describes what they must look like in the multitarget case, and contrasts them with the "plain-vanilla Bayesian approach."

  15. A Hierarchy of Heuristic-Based Models of Crowd Dynamics

    NASA Astrophysics Data System (ADS)

    Degond, P.; Appert-Rolland, C.; Moussaïd, M.; Pettré, J.; Theraulaz, G.

    2013-09-01

    We derive a hierarchy of kinetic and macroscopic models from a noisy variant of the heuristic behavioral Individual-Based Model of Ngai et al. (Disaster Med. Public Health Prep. 3:191-195, 2009) where pedestrians are supposed to have constant speeds. This IBM supposes that pedestrians seek the best compromise between navigation towards their target and collisions avoidance. We first propose a kinetic model for the probability distribution function of pedestrians. Then, we derive fluid models and propose three different closure relations. The first two closures assume that the velocity distribution function is either a Dirac delta or a von Mises-Fisher distribution respectively. The third closure results from a hydrodynamic limit associated to a Local Thermodynamical Equilibrium. We develop an analogy between this equilibrium and Nash equilibria in a game theoretic framework. In each case, we discuss the features of the models and their suitability for practical use.

  16. A Heuristic Approach to Examining Volatile Equilibrium at Titan's Surface

    NASA Technical Reports Server (NTRS)

    Samuelson, Robert E.

    1999-01-01

    R. D. Lorenz, J. I. Lunine, and C. P. McKay have shown in a manuscript accepted for publication that, for a given ethane abundance and surface temperature, the nitrogen and methane abundances in Titan's atmosphere can be calculated, yielding a surface pressure that can be compared with the observed value. This is potentially a very valuable tool for examining the evolution of Titan's climatology. Its validity does depend on two important assumptions, however: 1) that the atmosphere of Titan is in global radiative equilibrium, and 2) that volatiles present are in vapor equilibrium with the surface. The former assumption has been shown to be likely, but the latter has not. Water vapor in the Earth's atmosphere, in fact, is generally not very close to equilibrium in a global sense. In the present work a heuristic approach is used to examine the likelihood that methane vapor is in equilibrium with Titan's surface. Plausible climate scenerios are examined that are consistent with methane vapor abundances derived from Voyager IRIS data. Simple precipitation and surface diffusion models are incorporated into the analysis. It is tentatively inferred that methane may be in surface equilibrium near the poles, but that equilibrium at low latitudes is more difficult to establish.

  17. Cardiac Arrest and Gastrointestinal Bleeding: A Case of Medical Heuristics

    PubMed Central

    Ajayi, Tokunbo; Okudo, Jerome

    2016-01-01

    Insufficient clinical data from patients is a major cause of errors in medical diagnostics. In an attempt to make a diagnosis, initial clinical information provided to the physician may be overly relied on as the only information required in making diagnosis leading to anchoring. Failure to rely on differential diagnoses in spite of new signs and symptoms or rethinking of initial hypothesis may lead to fixation on a certain diagnosis, which may lead to significant morbidity and mortality. In the event that there is an anchoring heuristic, like in our patient, it is important to consider differential diagnoses; however, it is not wrong to rely on some form of anchor. We report a case of a 62-year-old male with a history of multiple medical conditions and a history of acetaminophen overdose who presented to the hospital with large amounts of coffee ground emesis. He was subsequently transferred to the liver transplant center on discovery that he was in fulminant hepatic failure and died two days later in spite of aggressive medical treatment. PMID:27366152

  18. A heuristic for the distribution of point counts for random curves over a finite field

    PubMed Central

    Achter, Jeffrey D.; Erman, Daniel; Kedlaya, Kiran S.; Wood, Melanie Matchett; Zureick-Brown, David

    2015-01-01

    How many rational points are there on a random algebraic curve of large genus g over a given finite field ? We propose a heuristic for this question motivated by a (now proven) conjecture of Mumford on the cohomology of moduli spaces of curves; this heuristic suggests a Poisson distribution with mean q+1+1/(q−1). We prove a weaker version of this statement in which g and q tend to infinity, with q much larger than g. PMID:25802415

  19. A heuristic criterion for instability to fragmentation in rotating, interstellar clouds

    NASA Technical Reports Server (NTRS)

    Boss, A. P.

    1982-01-01

    A heuristic criterion, based on linear perturbation analysis, is applied to the initial growth of density perturbations in isothermal or adiabatic gas clouds, with initially uniform density and uniform rotation. The heuristic criterion is shown to be consistent with the available results from numerical calculations of cloud collapse. The criterion predicts that perturbations varying as cos(m-phi) will be most likely to grow when m is small, unless the cloud is nearly pressureless.

  20. A Heuristic Criterion for Instability to Fragmentation in Rotating, Interstellar Clouds

    NASA Technical Reports Server (NTRS)

    Boss, Alan Paul

    1982-01-01

    A heuristic criterion, based on linear perturbation analysis, is applied to the initial growth of density perturbations in isothermal or adiabatic gas clouds, with initially uniform density and uniform rotation. The heuristic criterion is shown to be consistent with the available results from numerical calculations of cloud collapse. The criterion predicts that perturbations varying as cos (m(phi)) will be most likely to grow when )pi is small, unless the cloud is nearly pressureless.

  1. The inherence heuristic across development: systematic differences between children's and adults' explanations for everyday facts.

    PubMed

    Cimpian, Andrei; Steinberg, Olivia D

    2014-12-01

    The inherence heuristic is a basic cognitive process that supplies quick-and-easy answers to what are, in reality, incredibly complex questions about why the broad patterns of the world are as they are (Cimpian & Salomon, 2014-a, 2014-b). This explanatory heuristic satisfies the human need to understand, but it is also a source of bias because the heuristic relies too often on the (easily accessible) inherent features of the entities in the patterns being explained. Here, we investigated the developmental trajectory of this heuristic. Given that the cognitive resources that help override the typical output of the inherence heuristic are scarce in childhood, we hypothesized that the heuristic's output would be more broadly endorsed by children than by adults. Five experiments involving young children and adults (N=480) provided consistent support for this hypothesis. The first three experiments (Part I) investigated participants' explanations for broad patterns (e.g., fire trucks are red) and suggested that, consistent with our predictions, children were particularly likely to endorse inherence-based explanations. The last two experiments (Part II) investigated two intuitions that accompany the output of the inherence heuristic: namely, that the patterns being explained cannot be changed and are temporally stable. As predicted, participants' judgments on these dimensions showed the same developmental differences as the explanations investigated in Part I, with children being particularly likely to see patterns as inalterable and temporally stable. The developmental differences found across these five experiments suggest that children start out with a broad reliance on the explanatory output of the inherence heuristic, a reliance that narrows in scope to some extent as children develop. PMID:25291062

  2. TRStalker: an efficient heuristic for finding fuzzy tandem repeats

    PubMed Central

    Pellegrini, Marco; Renda, M. Elena; Vecchio, Alessio

    2010-01-01

    Motivation: Genomes in higher eukaryotic organisms contain a substantial amount of repeated sequences. Tandem Repeats (TRs) constitute a large class of repetitive sequences that are originated via phenomena such as replication slippage and are characterized by close spatial contiguity. They play an important role in several molecular regulatory mechanisms, and also in several diseases (e.g. in the group of trinucleotide repeat disorders). While for TRs with a low or medium level of divergence the current methods are rather effective, the problem of detecting TRs with higher divergence (fuzzy TRs) is still open. The detection of fuzzy TRs is propaedeutic to enriching our view of their role in regulatory mechanisms and diseases. Fuzzy TRs are also important as tools to shed light on the evolutionary history of the genome, where higher divergence correlates with more remote duplication events. Results: We have developed an algorithm (christened TRStalker) with the aim of detecting efficiently TRs that are hard to detect because of their inherent fuzziness, due to high levels of base substitutions, insertions and deletions. To attain this goal, we developed heuristics to solve a Steiner version of the problem for which the fuzziness is measured with respect to a motif string not necessarily present in the input string. This problem is akin to the ‘generalized median string’ that is known to be an NP-hard problem. Experiments with both synthetic and biological sequences demonstrate that our method performs better than current state of the art for fuzzy TRs and that the fuzzy TRs of the type we detect are indeed present in important biological sequences. Availability: TRStalker will be integrated in the web-based TRs Discovery Service (TReaDS) at bioalgo.iit.cnr.it. Contact: marco.pellegrini@iit.cnr.it Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20529928

  3. A Simple Heuristic Model of Nutrient Cycling in an Estuary

    NASA Astrophysics Data System (ADS)

    Kimmerer, W. J.; Smith, S. V.; Hollibaugh, J. T.

    1993-08-01

    Three decades of discussion and study have not resolved the apparent discrepancy between N-limitation of primary production and the ability of marine ecosystems to fix N. We use a simple model as a heuristic tool to examine controls on nutrient cycling in a shallow estuary, with Tomales Bay, California as the prototype. The model is a steady-state, one-box model with inputs and losses of nutrients and organic matter, and terms representing N-fixation and denitrification. The physical description of the system is deliberately kept simple to permit a focus on the key biogeochemical reactions. Growth of autotrophs in the model can be limited either by dissolved inorganic nitrogen (DIN) or dissolved inorganic phosphorus (DIP). Nitrogen-fixation is controlled by the availability of DIP or limited by excess amounts of DIN. Model results demonstrate that, for a system with a long residence time, autotroph biomass and total organic matter are controlled primarily by the rate of delivery of P to the system, either as DIP or in organic matter. Increasing the delivery rate of DIN raises autotroph biomass slightly but has little effect on total organic matter. This is because the rates of input of P as DIP or organic matter control the N-fixation rate, and denitrification limits the build-up of DIN in the system. Thus, denitrification and N-fixation act as opposing negative feedbacks, insuring that the supply of N remains roughly commensurate with that of P. When exchange with the ocean is increased, reducing residence time, the relative importance of DIN input increases relative to that of DIP.

  4. Mixed Integer Programming and Heuristic Scheduling for Space Communication

    NASA Technical Reports Server (NTRS)

    Lee, Charles H.; Cheung, Kar-Ming

    2013-01-01

    Optimal planning and scheduling for a communication network was created where the nodes within the network are communicating at the highest possible rates while meeting the mission requirements and operational constraints. The planning and scheduling problem was formulated in the framework of Mixed Integer Programming (MIP) to introduce a special penalty function to convert the MIP problem into a continuous optimization problem, and to solve the constrained optimization problem using heuristic optimization. The communication network consists of space and ground assets with the link dynamics between any two assets varying with respect to time, distance, and telecom configurations. One asset could be communicating with another at very high data rates at one time, and at other times, communication is impossible, as the asset could be inaccessible from the network due to planetary occultation. Based on the network's geometric dynamics and link capabilities, the start time, end time, and link configuration of each view period are selected to maximize the communication efficiency within the network. Mathematical formulations for the constrained mixed integer optimization problem were derived, and efficient analytical and numerical techniques were developed to find the optimal solution. By setting up the problem using MIP, the search space for the optimization problem is reduced significantly, thereby speeding up the solution process. The ratio of the dimension of the traditional method over the proposed formulation is approximately an order N (single) to 2*N (arraying), where N is the number of receiving antennas of a node. By introducing a special penalty function, the MIP problem with non-differentiable cost function and nonlinear constraints can be converted into a continuous variable problem, whose solution is possible.

  5. On two heuristic viewpoints concerning the study of light

    NASA Astrophysics Data System (ADS)

    Bi, Siwen

    2015-02-01

    It has been a debatable problem that what the essence of light is, and how it is produced. Since the modern times, as James Clerk Maxwell setting the theory of electromagnetic up, the mainstream consciousness was occupied gradually by the wave theory of light. But at the end of 19th century, a series experimental phenomenon weren't precisely explained by the wave theory of light such as photoelectric effect experiment. Then Albert Einstein published his famous paper "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", which laid the foundation of light quantum hypothesis. While solving these problems perfectly, a new problem was caused that because the wave theory and the quantum theory are both applicable to interpret some of the experiment of light, what is the essence of light. This paper first outlines the history of optical development and current status, and states the difficulties and deficiencies of the study of light. Then we put forward the key concept of the paper called lightstring which consults some points of the theory of modern optics and physics which called the optical frequency comb and the string theory, then presents the essence of light based on the light string concept in order to make the concept of photons specific. And then we put forward the production mechanism of light ---- the String-Light effect based on the concept of light string. In this paper, we attempt to put forward a new idea of the study of the essence of light and the production mechanism of it.

  6. The heuristic value of redundancy models of aging.

    PubMed

    Boonekamp, Jelle J; Briga, Michael; Verhulst, Simon

    2015-11-01

    Molecular studies of aging aim to unravel the cause(s) of aging bottom-up, but linking these mechanisms to organismal level processes remains a challenge. We propose that complementary top-down data-directed modelling of organismal level empirical findings may contribute to developing these links. To this end, we explore the heuristic value of redundancy models of aging to develop a deeper insight into the mechanisms causing variation in senescence and lifespan. We start by showing (i) how different redundancy model parameters affect projected aging and mortality, and (ii) how variation in redundancy model parameters relates to variation in parameters of the Gompertz equation. Lifestyle changes or medical interventions during life can modify mortality rate, and we investigate (iii) how interventions that change specific redundancy parameters within the model affect subsequent mortality and actuarial senescence. Lastly, as an example of data-directed modelling and the insights that can be gained from this, (iv) we fit a redundancy model to mortality patterns observed by Mair et al. (2003; Science 301: 1731-1733) in Drosophila that were subjected to dietary restriction and temperature manipulations. Mair et al. found that dietary restriction instantaneously reduced mortality rate without affecting aging, while temperature manipulations had more transient effects on mortality rate and did affect aging. We show that after adjusting model parameters the redundancy model describes both effects well, and a comparison of the parameter values yields a deeper insight in the mechanisms causing these contrasting effects. We see replacement of the redundancy model parameters by more detailed sub-models of these parameters as a next step in linking demographic patterns to underlying molecular mechanisms. PMID:26362219

  7. Using an Enhanced Conflict Map in the Classroom (Photoelectric Effect) Based on Lakatosian Heuristic Principle Strategies

    ERIC Educational Resources Information Center

    Oh, Jun-Young

    2011-01-01

    Researchers have shown that most students resist changes to their core beliefs by offering auxiliary hypotheses at the first sign of the development of conceptual change. Studies have viewed student reaction to discrepant events as an important clue in helping researchers understand not only the structure of alternative concepts (Niaz, "Science &…

  8. Conceptual space systems design using meta-heuristic algorithms

    NASA Astrophysics Data System (ADS)

    Kim, Byoungsoo

    criteria. Two meta-heuristic optimization algorithms, Genetic Algorithms (GAs) and Simulated Annealing (SA), were used to optimize the formulated (simply bounded) Constrained Combinatorial Conceptual Space Systems Design Model. GAs and SA were demonstrated on the SAMPEX (Solar Anomalous & Magnetospheric Particle Explorer) Space System. The Conceptual Space Systems Design Model developed in this thesis can be used as an assessment tool to evaluate and validate Space System proposals.

  9. The power of simplicity: a fast-and-frugal heuristics approach to performance science

    PubMed Central

    Raab, Markus; Gigerenzer, Gerd

    2015-01-01

    Performance science is a fairly new multidisciplinary field that integrates performance domains such as sports, medicine, business, and the arts. To give its many branches a structure and its research a direction, it requires a theoretical framework. We demonstrate the applications of this framework with examples from sport and medicine. Because performance science deals mainly with situations of uncertainty rather than known risks, the needed framework can be provided by the fast-and-frugal heuristics approach. According to this approach, experts learn to rely on heuristics in an adaptive way in order to make accurate decisions. We investigate the adaptive use of heuristics in three ways: the descriptive study of the heuristics in the cognitive “adaptive toolbox;” the prescriptive study of their “ecological rationality,” that is, the characterization of the situations in which a given heuristic works; and the engineering study of “intuitive design,” that is, the design of transparent aids for making better decisions. PMID:26579051

  10. Meta-Heuristic Combining Prior Online and Offline Information for the Quadratic Assignment Problem.

    PubMed

    Sun, Jianyong; Zhang, Qingfu; Yao, Xin

    2014-03-01

    The construction of promising solutions for NP-hard combinatorial optimization problems (COPs) in meta-heuristics is usually based on three types of information, namely a priori information, a posteriori information learned from visited solutions during the search procedure, and online information collected in the solution construction process. Prior information reflects our domain knowledge about the COPs. Extensive domain knowledge can surely make the search effective, yet it is not always available. Posterior information could guide the meta-heuristics to globally explore promising search areas, but it lacks local guidance capability. On the contrary, online information can capture local structures, and its application can help exploit the search space. In this paper, we studied the effects of using this information on metaheuristic's algorithmic performances for the COPs. The study was illustrated by a set of heuristic algorithms developed for the quadratic assignment problem. We first proposed an improved scheme to extract online local information, then developed a unified framework under which all types of information can be combined readily. Finally, we studied the benefits of the three types of information to meta-heuristics. Conclusions were drawn from the comprehensive study, which can be used as principles to guide the design of effective meta-heuristic in the future. PMID:23757559

  11. Knee model: Comparison between heuristic and rigorous solutions for the Schumann resonance problem

    NASA Astrophysics Data System (ADS)

    Galuk, Yu. P.; Nickolaenko, A. P.; Hayakawa, M.

    2015-12-01

    Rapid development of computers allows for application of the direct numerical solution of the global electromagnetic resonance problem in the Earth-ionosphere cavity. Direct numerical solutions exploit the cavity models with the given conductivity profile of atmosphere such as exponential or the knee profiles. These profiles are usually derived from the knee model by Mushtak and Williams (2002) developed for obtaining the realistic ELF propagation constant. It is usually forgotten that profiles of the knee model are only a convenient approximate interpretation for the heuristic relations used in computations. We demonstrate that the rigorous full wave solution of the electromagnetic problem for such profiles deviates from that obtained in the knee model. Therefore the direct numerical solutions must also depart from the heuristic one. We evaluate deviations of the heuristic knee model data from those pertinent to equivalent profile of atmospheric conductivity.

  12. Performance of heuristic methods driven by chaotic dynamics for ATSP and applications to DNA fragment assembly

    NASA Astrophysics Data System (ADS)

    Kato, Tomohiro; Hasegawa, Mikio

    Chaotic dynamics has been shown to be effective in improving the performance of combinatorial optimization algorithms. In this paper, the performance of chaotic dynamics in the asymmetric traveling salesman problem (ATSP) is investigated by introducing three types of heuristic solution update methods. Numerical simulation has been carried out to compare its performance with simulated annealing and tabu search; thus, the effectiveness of the approach using chaotic dynamics for driving heuristic methods has been shown. The chaotic method is also evaluated in the case of a combinatorial optimization problem in the real world, which can be solved by the same heuristic operation as that for the ATSP. We apply the chaotic method to the DNA fragment assembly problem, which involves building a DNA sequence from several hundred fragments obtained by the genome sequencer. Our simulation results show that the proposed algorithm using chaotic dynamics in a block shift operation exhibits the best performance for the DNA fragment assembly problem.

  13. A practical implementation science heuristic for organizational readiness: R = MC2

    PubMed Central

    Cook, Brittany S.; Lamont, Andrea; Wandersman, Abraham; Castellow, Jennifer; Katz, Jason; Beidas, Rinad S.

    2015-01-01

    There are many challenges when an innovation (i.e., a program, process, or policy that is new to an organization) is actively introduced into an organization. One critical component for successful implementation is the organization’s readiness for the innovation. In this article, we propose a practical implementation science heuristic, abbreviated as R= MC2. We propose that organizational readiness involves: 1) the motivation to implement an innovation, 2) the general capacities of an organization, and 3) the innovation-specific capacities needed for a particular innovation. Each of these components can be assessed independently and be used formatively. The heuristic can be used by organizations to assess readiness to implement and by training and technical assistance providers to help build organizational readiness. We present an illustration of the heuristic by showing how behavioral health organizations differ in readiness to implement a peer specialist initiative. Implications for research and practice of organizational readiness are discussed. PMID:26668443

  14. Biases and Heuristics in Decision Making and Their Impact on Autonomy.

    PubMed

    Blumenthal-Barby, J S

    2016-05-01

    Cognitive scientists have identified a wide range of biases and heuristics in human decision making over the past few decades. Only recently have bioethicists begun to think seriously about the implications of these findings for topics such as agency, autonomy, and consent. This article aims to provide an overview of biases and heuristics that have been identified and a framework in which to think comprehensively about the impact of them on the exercise of autonomous decision making. I analyze the impact that these biases and heuristics have on the following dimensions of autonomy: understanding, intentionality, absence of alienating or controlling influence, and match between formally autonomous preferences or decisions and actual choices or actions. PMID:27111357

  15. Monolingual, bilingual, trilingual: infants' language experience influences the development of a word-learning heuristic.

    PubMed

    Byers-Heinlein, Krista; Werker, Janet F

    2009-09-01

    How infants learn new words is a fundamental puzzle in language acquisition. To guide their word learning, infants exploit systematic word-learning heuristics that allow them to link new words to likely referents. By 17 months, infants show a tendency to associate a novel noun with a novel object rather than a familiar one, a heuristic known as disambiguation. Yet, the developmental origins of this heuristic remain unknown. We compared disambiguation in 17- to 18-month-old infants from different language backgrounds to determine whether language experience influences its development, or whether disambiguation instead emerges as a result of maturation or social experience. Monolinguals showed strong use of disambiguation, bilinguals showed marginal use, and trilinguals showed no disambiguation. The number of languages being learned, but not vocabulary size, predicted performance. The results point to a key role for language experience in the development of disambiguation, and help to distinguish among theoretical accounts of its emergence. PMID:19702772

  16. Developing Biology Lessons Aimed at Teaching for Understanding: A Domain-specific Heuristic for Student Teachers

    NASA Astrophysics Data System (ADS)

    Janssen, Fred J. J. M.; Tigelaar, Dineke E. H.; Verloop, Nico

    2009-02-01

    Teaching for understanding requires teachers to organize thought-demanding activities which continually challenge students to apply and extend their prior knowledge. Research shows that student teachers often are unable to develop lessons in teaching for understanding. We explored how a domain-specific heuristic can assist student biology teachers in developing problem-posing lessons according to teaching for understanding. Worksheets of lesson plans were analyzed according to criteria for problem-posing lessons. Furthermore, student teachers’ perceptions of the design heuristic’s usefulness were categorized in a cyclical process. In general, the heuristic appeared helpful to most student teachers for designing problem-posing lessons satisfactory according to the criteria. Furthermore, teachers indicated that using the heuristic deepened their subject matter knowledge and their awareness of pupils’ prior knowledge.

  17. Social Outcomes in Childhood Brain Disorder: A Heuristic Integration of Social Neuroscience and Developmental Psychology

    PubMed Central

    Yeates, Keith Owen; Bigler, Erin D.; Dennis, Maureen; Gerhardt, Cynthia A.; Rubin, Kenneth H.; Stancin, Terry; Taylor, H. Gerry; Vannatta, Kathryn

    2010-01-01

    The authors propose a heuristic model of the social outcomes of childhood brain disorder that draws on models and methods from both the emerging field of social cognitive neuroscience and the study of social competence in developmental psychology/psychopathology. The heuristic model characterizes the relationships between social adjustment, peer interactions and relationships, social problem solving and communication, social-affective and cognitive-executive processes, and their neural substrates. The model is illustrated by research on a specific form of childhood brain disorder, traumatic brain injury. The heuristic model may promote research regarding the neural and cognitive-affective substrates of children’s social development. It also may engender more precise methods of measuring impairments and disabilities in children with brain disorder and suggest ways to promote their social adaptation. PMID:17469991

  18. Does interaction matter? Testing whether a confidence heuristic can replace interaction in collective decision-making

    PubMed Central

    Bang, Dan; Fusaroli, Riccardo; Tylén, Kristian; Olsen, Karsten; Latham, Peter E.; Lau, Jennifer Y.F.; Roepstorff, Andreas; Rees, Geraint; Frith, Chris D.; Bahrami, Bahador

    2014-01-01

    In a range of contexts, individuals arrive at collective decisions by sharing confidence in their judgements. This tendency to evaluate the reliability of information by the confidence with which it is expressed has been termed the ‘confidence heuristic’. We tested two ways of implementing the confidence heuristic in the context of a collective perceptual decision-making task: either directly, by opting for the judgement made with higher confidence, or indirectly, by opting for the faster judgement, exploiting an inverse correlation between confidence and reaction time. We found that the success of these heuristics depends on how similar individuals are in terms of the reliability of their judgements and, more importantly, that for dissimilar individuals such heuristics are dramatically inferior to interaction. Interaction allows individuals to alleviate, but not fully resolve, differences in the reliability of their judgements. We discuss the implications of these findings for models of confidence and collective decision-making. PMID:24650632

  19. Application of heuristic satellite plan synthesis algorithms to requirements of the WARC-88 allotment plan

    NASA Technical Reports Server (NTRS)

    Heyward, Ann O.; Reilly, Charles H.; Walton, Eric K.; Mata, Fernando; Olen, Carl

    1990-01-01

    Creation of an Allotment Plan for the Fixed Satellite Service at the 1988 Space World Administrative Radio Conference (WARC) represented a complex satellite plan synthesis problem, involving a large number of planned and existing systems. Solutions to this problem at WARC-88 required the use of both automated and manual procedures to develop an acceptable set of system positions. Development of an Allotment Plan may also be attempted through solution of an optimization problem, known as the Satellite Location Problem (SLP). Three automated heuristic procedures, developed specifically to solve SLP, are presented. The heuristics are then applied to two specific WARC-88 scenarios. Solutions resulting from the fully automated heuristics are then compared with solutions obtained at WARC-88 through a combination of both automated and manual planning efforts.

  20. A Case Study of Controlling Crossover in a Selection Hyper-heuristic Framework Using the Multidimensional Knapsack Problem.

    PubMed

    Drake, John H; Özcan, Ender; Burke, Edmund K

    2016-01-01

    Hyper-heuristics are high-level methodologies for solving complex problems that operate on a search space of heuristics. In a selection hyper-heuristic framework, a heuristic is chosen from an existing set of low-level heuristics and applied to the current solution to produce a new solution at each point in the search. The use of crossover low-level heuristics is possible in an increasing number of general-purpose hyper-heuristic tools such as HyFlex and Hyperion. However, little work has been undertaken to assess how best to utilise it. Since a single-point search hyper-heuristic operates on a single candidate solution, and two candidate solutions are required for crossover, a mechanism is required to control the choice of the other solution. The frameworks we propose maintain a list of potential solutions for use in crossover. We investigate the use of such lists at two conceptual levels. First, crossover is controlled at the hyper-heuristic level where no problem-specific information is required. Second, it is controlled at the problem domain level where problem-specific information is used to produce good-quality solutions to use in crossover. A number of selection hyper-heuristics are compared using these frameworks over three benchmark libraries with varying properties for an NP-hard optimisation problem: the multidimensional 0-1 knapsack problem. It is shown that allowing crossover to be managed at the domain level outperforms managing crossover at the hyper-heuristic level in this problem domain. PMID:25635698

  1. Aging and strategic retrieval processes: reducing false memories with a distinctiveness heuristic.

    PubMed

    Dodson, Chad S; Schacter, Daniel L

    2002-09-01

    The authors show that a strategic retrieval process--the distinctiveness heuristic--is a powerful mechanism for reducing false memories in the elderly. Individuals studied words, pictures, or both types of items and then completed a recognition test on which the studied items appeared once, whereas the new words appeared twice. After studying either pictures only or a mixture of pictures and words, both younger and older adults falsely recognized fewer repeated new words than did participants who studied words. Studying pictures provided a basis for using a distinctiveness heuristic during the recognition test: Individuals inferred that the absence of memory for picture information indicates that an item is "new." PMID:12243382

  2. Application of a hybrid generation/utility assessment heuristic to a class of scheduling problems

    NASA Technical Reports Server (NTRS)

    Heyward, Ann O.

    1989-01-01

    A two-stage heuristic solution approach for a class of multiobjective, n-job, 1-machine scheduling problems is described. Minimization of job-to-job interference for n jobs is sought. The first stage generates alternative schedule sequences by interchanging pairs of schedule elements. The set of alternative sequences can represent nodes of a decision tree; each node is reached via decision to interchange job elements. The second stage selects the parent node for the next generation of alternative sequences through automated paired comparison of objective performance for all current nodes. An application of the heuristic approach to communications satellite systems planning is presented.

  3. Individual differences in use of the recognition heuristic are stable across time, choice objects, domains, and presentation formats.

    PubMed

    Michalkiewicz, Martha; Erdfelder, Edgar

    2016-04-01

    The recognition heuristic (RH) is a simple decision strategy that performs surprisingly well in many domains. According to the RH, people decide on the basis of recognition alone and ignore further knowledge when faced with a recognized and an unrecognized choice object. Previous research has revealed noteworthy individual differences in RH use, suggesting that people have preferences for using versus avoiding this strategy that might be causally linked to cognitive or personality traits. However, trying to explain differences in RH use in terms of traits presupposes temporal and cross-situational stability in use of the RH, an important prerequisite that has not been scrutinized so far. In a series of four experiments, we therefore assessed the stability in RH use across (1) time, (2) choice objects, (3) domains, and (4) presentation formats of the choice objects. In Experiment 1, participants worked on the same inference task and choice objects twice, separated by a delay of either one day or one week. Experiment 2 replicated Experiment 1 using two different object sets from the same domain, whereas Experiment 3 assessed the stability of RH use across two different domains. Finally, in Experiment 4 we investigated stability across verbal and pictorial presentation formats of the choice objects. For all measures of RH use proposed so far, we found strong evidence for both temporal and cross-situational stability in use of the RH. Thus, RH use at least partly reflects a person-specific style of decision making whose determinants await further research. PMID:26573057

  4. Personal Agency in Leadership Learning Using an Australian Heuristic

    ERIC Educational Resources Information Center

    Lovett, Susan; Dempster, Neil; Flückiger, Bev

    2015-01-01

    The starting point for this article is the lack of a robust research base regarding details of what works and why for school leaders' professional development. The article extends work undertaken for a recent commissioned literature review of selected international reports on supporting school leaders' development strategies. The authors…

  5. Fast and Frugal Heuristics Are Plausible Models of Cognition: Reply to Dougherty, Franco-Watkins, and Thomas (2008)

    ERIC Educational Resources Information Center

    Gigerenzer, Gerd; Hoffrage, Ulrich; Goldstein, Daniel G.

    2008-01-01

    M. R. Dougherty, A. M. Franco-Watkins, and R. Thomas (2008) conjectured that fast and frugal heuristics need an automatic frequency counter for ordering cues. In fact, only a few heuristics order cues, and these orderings can arise from evolutionary, social, or individual learning, none of which requires automatic frequency counting. The idea that…

  6. Trends Concerning Four Misconceptions in Students' Intuitively-Based Probabilistic Reasoning Sourced in the Heuristic of Representativeness

    ERIC Educational Resources Information Center

    Kustos, Paul Nicholas

    2010-01-01

    Student difficulty in the study of probability arises in intuitively-based misconceptions derived from heuristics. One such heuristic, the one of note for this research study, is that of representativeness, in which an individual informally assesses the probability of an event based on the degree to which the event is similar to the sample from…

  7. Rising above My Raisin'?: Using Heuristic Inquiry to Explore the Effects of the Lumbee Dialect on Ethnic Identity Development

    ERIC Educational Resources Information Center

    Scott, Chris; Brown, Kathleen

    2008-01-01

    Using heuristic inquiry, this study investigates how dialect affects the ethnic identity development of the first author as well as fellow Lumbee students attending a predominantly white university. Heuristic inquiry is a process that begins with a question or problem that the researcher seeks to illuminate or answer. Findings from this study…

  8. At the Crossroads: Portrait of an Undergraduate Composition Teacher Whose Heuristics Were Transformed by Computer-Technology

    ERIC Educational Resources Information Center

    Grover, Susan Hendricks

    2010-01-01

    Heuristics are deeply-held, tacit knowledge structures connected to our feelings. A heuristic study explores a phenomenon crucial to the researcher's self-discovery (Moustakas, 1990). Like me, many undergraduate composition instructors feel both fear and hope at the crossroads of composition and technology. Technology and composition shape one…

  9. The Effectiveness of Local Culture-Based Mathematical Heuristic-KR Learning towards Enhancing Student's Creative Thinking Skill

    ERIC Educational Resources Information Center

    Tandiseru, Selvi Rajuaty

    2015-01-01

    The problem in this research is the lack of creative thinking skills of students. One of the learning models that is expected to enhance student's creative thinking skill is the local culture-based mathematical heuristic-KR learning model (LC-BMHLM). Heuristic-KR is a learning model which was introduced by Krulik and Rudnick (1995) that is the…

  10. Evaluation of the Priority Heuristic as a Descriptive Model of Risky Decision Making: Comment on Brandstatter, Gigerenzer, and Hertwig (2006)

    ERIC Educational Resources Information Center

    Birnbaum, Michael H.

    2008-01-01

    E. Brandstatter, G. Gigerenzer, and R. Hertwig (2006) contended that their priority heuristic, a type of lexicographic semiorder model, is more accurate than cumulative prospect theory (CPT) or transfer of attention exchange (TAX) models in describing risky decisions. However, there are 4 problems with their argument. First, their heuristic is not…

  11. Improving Critical Thinking Skills Using Learning Model Logan Avenue Problem Solving (LAPS)-Heuristic

    ERIC Educational Resources Information Center

    Anggrianto, Desi; Churiyah, Madziatul; Arief, Mohammad

    2016-01-01

    This research was conducted in order to know the effect of Logan Avenue Problem Solving (LAPS)-Heuristic learning model towards critical thinking skills of students of class X Office Administration (APK) in SMK Negeri 1 Ngawi, East Java, Indonesia on material curve and equilibrium of demand and supply, subject Introduction to Economics and…

  12. A Comparison of Heuristic Procedures for Minimum within-Cluster Sums of Squares Partitioning

    ERIC Educational Resources Information Center

    Brusco, Michael J.; Steinley, Douglas

    2007-01-01

    Perhaps the most common criterion for partitioning a data set is the minimization of the within-cluster sums of squared deviation from cluster centroids. Although optimal solution procedures for within-cluster sums of squares (WCSS) partitioning are computationally feasible for small data sets, heuristic procedures are required for most practical…

  13. Heuristic Social Information Processing and Its Implications for Behavioral Measurement: An Example Based on Leadership Categorization.

    ERIC Educational Resources Information Center

    Lord, Robert G.

    Behavioral measurement using untrained organizational members as raters is highly dependent on heuristic or automatic processes. Such processes direct attention, simplify encoding and storage, and guide recall of behavioral information by using pre-existing schema to simplify processing; however, such processing results in systematic rather than…

  14. The Impact of Using the Heuristic Teaching Method on Jordanian Mathematics Students

    ERIC Educational Resources Information Center

    Al-Fayez, Mona Qutefan; Jubran, Sereen Mousa

    2012-01-01

    This study investigates the impact of using the heuristic teaching approach for teaching mathematics to tenth grade students in Jordan. The researchers followed the equivalent pre/post T test two group designs. To achieve the goal of the study, a pre/post- test was constructed to measure student achievement in mathematics. The sample for this…

  15. Psychological Plausibility of the Theory of Probabilistic Mental Models and the Fast and Frugal Heuristics

    ERIC Educational Resources Information Center

    Dougherty, Michael R.; Franco-Watkins, Ana M.; Thomas, Rick

    2008-01-01

    The theory of probabilistic mental models (PMM; G. Gigerenzer, U. Hoffrage, & H. Kleinbolting, 1991) has had a major influence on the field of judgment and decision making, with the most recent important modifications to PMM theory being the identification of several fast and frugal heuristics (G. Gigerenzer & D. G. Goldstein, 1996). These…

  16. Introducing Heuristics of Cultural Dimensions into the Service-Level Technical Communication Classroom

    ERIC Educational Resources Information Center

    Schafer, Robert

    2009-01-01

    A significant problem for practitioners of technical communication is to gain the skills to compete in a global, multicultural work environment. Instructors of technical communication can provide future practitioners with the tools to compete and excel in this global environment by introducing heuristics of cultural dimensions into the…

  17. Example-Based Learning in Heuristic Domains: A Cognitive Load Theory Account

    ERIC Educational Resources Information Center

    Renkl, Alexander; Hilbert, Tatjana; Schworm, Silke

    2009-01-01

    One classical instructional effect of cognitive load theory (CLT) is the worked-example effect. Although the vast majority of studies have focused on well-structured and algorithmic sub-domains of mathematics or physics, more recent studies have also analyzed learning with examples from complex domains in which only heuristic solution strategies…

  18. The Historical Ideal-Type as a Heuristic Device for Academic Storytelling by Sport Scholars

    ERIC Educational Resources Information Center

    Tutka, Patrick; Seifried, Chad

    2015-01-01

    The goal of this research endeavor is to take the previous calls of sport scholars to expand into alternative research approaches (e.g., history, case study, law reviews, philosophy, etc.) and to show how storytelling can be an effective tool through the use of a heuristic device. The present analysis attempts to focus on the usage of the…

  19. The Role of Heuristic Knowledge in Vietnamese American Students' Success at a Midwestern Community College

    ERIC Educational Resources Information Center

    Bottrell, Cynthia A.; Banning, James H.; Harbour, Clifford P.; Krahnke, Keiko

    2007-01-01

    This qualitative research study investigated the development of heuristic knowledge and its role in the academic and social journeys of five Vietnamese American students enrolled at a community college located in the American Midwest. The participants were interviewed in depth to understand their "lived experiences" while attending the community…

  20. Using the Science Writing Heuristic to Improve Students' Understanding of General Equilibrium

    ERIC Educational Resources Information Center

    Rudd, James A., II; Greenbowe, Thomas J.; Hand, Brian M.

    2007-01-01

    This study compared the performance of students using the Science Writing Heuristic (SWH) approach and students using a standard or traditional laboratory curriculum on lecture exams and a laboratory practical exam on a specific topic, chemical equilibrium. The SWH helps students do inquiry science laboratory work by structuring the laboratory…

  1. Twilight of the Slogans: A Heuristic Investigation of Linguistic Memes Using Mixed Methods

    ERIC Educational Resources Information Center

    Duffy, Curt Paul

    2013-01-01

    Slogans, or linguistic memes, are short, memorable phrases that are present in commercial, political, and everyday discourse. Slogans propagate similarly to other memes, or cultural units, through an evolutionary mechanism first proposed by Dawkins (1976). Heuristic inquiry, as presented by Moustakas (1990), provided a template from which to…

  2. A Heuristic Tool for Teaching Business Writing: Self-Assessment, Knowledge Transfer, and Writing Exercises

    ERIC Educational Resources Information Center

    Ortiz, Lorelei A.

    2013-01-01

    To teach effective business communication, instructors must target students’ current weaknesses in writing. One method for doing so is by assigning writing exercises. When used heuristically, writing exercises encourage students to practice self-assessment, self-evaluation, active learning, and knowledge transfer, all while reinforcing the basics…

  3. A Comparison of Heuristic and Human Performance on Open Versions of the Traveling Salesperson Problem

    ERIC Educational Resources Information Center

    MacGregor, James N.; Chronicle, Edward P.; Ormerod, Thomas C.

    2006-01-01

    We compared the performance of three heuristics with that of subjects on variants of a well-known combinatorial optimization task, the Traveling Salesperson Problem (TSP). The present task consisted of finding the shortest path through an array of points from one side of the array to the other. Like the standard TSP, the task is computationally…

  4. The Nature of Elementary Student Science Discourse in the Context of the Science Writing Heuristic Approach

    ERIC Educational Resources Information Center

    Cavagnetto, Andy; Hand, Brian M.; Norton-Meier, Lori

    2010-01-01

    This case study aimed to determine the nature of student interactions in small groups in an elementary classroom utilizing the Science Writing Heuristic approach. Fifth grade students were audio-recorded over four units of study while working in small groups to generate knowledge claims after conducting student-directed investigations. Analysis…

  5. Compound Cue Processing within the Fast and Frugal Heuristics Approach in Nonlinearly Separable Environments

    ERIC Educational Resources Information Center

    Garcia-Retamero, Rocio; Hoffrage, Ulrich; Dieckmann, Anja; Ramos, Manuel

    2007-01-01

    Three experiments investigated whether participants used Take The Best (TTB) Configural, a fast and frugal heuristic that processes configurations of cues when making inferences concerning which of two alternatives has a higher criterion value. Participants were presented with a compound cue that was nonlinearly separable from its elements. The…

  6. Multi-objective Decision Based Available Transfer Capability in Deregulated Power System Using Heuristic Approaches

    NASA Astrophysics Data System (ADS)

    Pasam, Gopi Krishna; Manohar, T. Gowri

    2015-07-01

    Determination of available transfer capability (ATC) requires the use of experience, intuition and exact judgment in order to meet several significant aspects in the deregulated environment. Based on these points, this paper proposes two heuristic approaches to compute ATC. The first proposed heuristic algorithm integrates the five methods known as continuation repeated power flow, repeated optimal power flow, radial basis function neural network, back propagation neural network and adaptive neuro fuzzy inference system to obtain ATC. The second proposed heuristic model is used to obtain multiple ATC values. Out of these, a specific ATC value will be selected based on a number of social, economic, deregulated environmental constraints and related to specific applications like optimization, on-line monitoring, and ATC forecasting known as multi-objective decision based optimal ATC. The validity of results obtained through these proposed methods are scrupulously verified on various buses of the IEEE 24-bus reliable test system. The results presented and derived conclusions in this paper are very useful for planning, operation, maintaining of reliable power in any power system and its monitoring in an on-line environment of deregulated power system. In this way, the proposed heuristic methods would contribute the best possible approach to assess multiple objective ATC using integrated methods.

  7. Ignorance- versus Evidence-Based Decision Making: A Decision Time Analysis of the Recognition Heuristic

    ERIC Educational Resources Information Center

    Hilbig, Benjamin E.; Pohl, Rudiger F.

    2009-01-01

    According to part of the adaptive toolbox notion of decision making known as the recognition heuristic (RH), the decision process in comparative judgments--and its duration--is determined by whether recognition discriminates between objects. By contrast, some recently proposed alternative models predict that choices largely depend on the amount of…

  8. One-Reason Decision Making Unveiled: A Measurement Model of the Recognition Heuristic

    ERIC Educational Resources Information Center

    Hilbig, Benjamin E.; Erdfelder, Edgar; Pohl, Rudiger F.

    2010-01-01

    The fast-and-frugal recognition heuristic (RH) theory provides a precise process description of comparative judgments. It claims that, in suitable domains, judgments between pairs of objects are based on recognition alone, whereas further knowledge is ignored. However, due to the confound between recognition and further knowledge, previous…

  9. Getting Smart with Computers: Computer-Aided Heuristics for Student Writers.

    ERIC Educational Resources Information Center

    Kemp, Fred

    1987-01-01

    Evaluates several views of the relationship between computers and education, and criticizes the use of artificial intelligence and natural language processing software for evaluating student writing. Recommends utilizing programs that use heuristic methods to ask students a series of questions to help them organize and compose papers. (SKC)

  10. Experimental studies of access graph based heuristics: Beating the LRU standard?

    SciTech Connect

    Fiat, A.; Rosen, Z.

    1997-06-01

    In this paper we devise new paging heuristics motivated by the access graph model of paging. Unlike the access graph model and the related Markov paging model our heuristics are truly on-line in that we do not assume any prior knowledge of the program just about to be executed. The Least Recently Used heuristic for paging is remarkably good, and is known experimentally to be superior to many of the suggested alternatives on real program traces. Experiments we`ve performed suggest that our heuristics beat LRU fairly consistently, over a wide range of cache sizes and programs. The number of page faults can be as low as {1/2} the number of page faults for LRU and is on average 7 to 9 percent less than the number of faults for LRU. (Depending on how this average is computed.) We have built a program tracer that gives the page access sequence for real program executions of 200 - 3,300 thousand page access requests, and our simulations are based on 25 of these program traces. Overall, we have performed several thousand such simulations. While we have no real evidence to suggest that the programs we`ve traced are typical in any sense, we have made use of an experimental {open_quotes}protocol{close_quotes} designed to avoid experimenter bias. We strongly emphasize that our results are only preliminary and that much further work needs to be done.

  11. Teaching High School Students to Use Heuristics while Reading Historical Texts

    ERIC Educational Resources Information Center

    Nokes, Jeffery D.; Dole, Janice A.; Hacker, Douglas J.

    2007-01-01

    The purpose of this study was to test the effectiveness of different types of instruction and texts on high schools students' learning of (a) history content and (b) a set of heuristics that historians use to think critically about texts. Participants for the study were 128 male and 118 female students, ages 16 and 17 years, from 2 high schools in…

  12. The Effects of Polya's Heuristic and Diary Writing on Children's Problem Solving

    ERIC Educational Resources Information Center

    Hensberry, Karina K. R.; Jacobbe, Tim

    2012-01-01

    This paper presents the results of a study that aimed at increasing students' problem-solving skills. Polya's (1985) heuristic for problem solving was used and students were required to articulate their thought processes through the use of a structured diary. The diary prompted students to answer questions designed to engage them in the phases of…

  13. Using the Science Writing Heuristic Approach to Enhance Student Understanding in Chemical Change and Mixture

    ERIC Educational Resources Information Center

    Kingir, Sevgi; Geban, Omer; Gunel, Murat

    2013-01-01

    This study investigated the effect of the Science Writing Heuristic (SWH) approach on grade 9 students' understanding of chemical change and mixture concepts. Four intact classes taught by two chemistry teachers from a Turkish public high school were selected for the study; one class was assigned as the treatment group, and the other class…

  14. Transformative Learning and Spirituality: A Heuristic Inquiry into the Experience of Spiritual Learning

    ERIC Educational Resources Information Center

    Campbell, Karen P.

    2010-01-01

    The purpose of this heuristic study was to explore the ways in which spirituality informed and impacted educators' own experience of learning as a transformative inner encounter. It inquired into the experience of learning from a spiritual perspective in order to determine the extent to which transformative learning could be described as a…

  15. The Measurement of Creativity: From Definitional Consensus to the Introduction of a New Heuristic Framework

    ERIC Educational Resources Information Center

    Batey, Mark

    2012-01-01

    The scientific study of creativity has proven a difficult undertaking. Researchers have employed a diversity of definitions and measurement methods. As a result, creativity research is underrepresented in the literature and the findings of different studies often prove difficult to draw into a coherent body of understanding. A heuristic framework…

  16. Simple Heuristic Approach to Introduction of the Black-Scholes Model

    ERIC Educational Resources Information Center

    Yalamova, Rossitsa

    2010-01-01

    A heuristic approach to explaining of the Black-Scholes option pricing model in undergraduate classes is described. The approach draws upon the method of protocol analysis to encourage students to "think aloud" so that their mental models can be surfaced. It also relies upon extensive visualizations to communicate relationships that are…

  17. Approach to design neural cryptography: A generalized architecture and a heuristic rule

    NASA Astrophysics Data System (ADS)

    Mu, Nankun; Liao, Xiaofeng; Huang, Tingwen

    2013-06-01

    Neural cryptography, a type of public key exchange protocol, is widely considered as an effective method for sharing a common secret key between two neural networks on public channels. How to design neural cryptography remains a great challenge. In this paper, in order to provide an approach to solve this challenge, a generalized network architecture and a significant heuristic rule are designed. The proposed generic framework is named as tree state classification machine (TSCM), which extends and unifies the existing structures, i.e., tree parity machine (TPM) and tree committee machine (TCM). Furthermore, we carefully study and find that the heuristic rule can improve the security of TSCM-based neural cryptography. Therefore, TSCM and the heuristic rule can guide us to designing a great deal of effective neural cryptography candidates, in which it is possible to achieve the more secure instances. Significantly, in the light of TSCM and the heuristic rule, we further expound that our designed neural cryptography outperforms TPM (the most secure model at present) on security. Finally, a series of numerical simulation experiments are provided to verify validity and applicability of our results.

  18. QoE collaborative evaluation method based on fuzzy clustering heuristic algorithm.

    PubMed

    Bao, Ying; Lei, Weimin; Zhang, Wei; Zhan, Yuzhuo

    2016-01-01

    At present, to realize or improve the quality of experience (QoE) is a major goal for network media transmission service, and QoE evaluation is the basis for adjusting the transmission control mechanism. Therefore, a kind of QoE collaborative evaluation method based on fuzzy clustering heuristic algorithm is proposed in this paper, which is concentrated on service score calculation at the server side. The server side collects network transmission quality of service (QoS) parameter, node location data, and user expectation value from client feedback information. Then it manages the historical data in database through the "big data" process mode, and predicts user score according to heuristic rules. On this basis, it completes fuzzy clustering analysis, and generates service QoE score and management message, which will be finally fed back to clients. Besides, this paper mainly discussed service evaluation generative rules, heuristic evaluation rules and fuzzy clustering analysis methods, and presents service-based QoE evaluation processes. The simulation experiments have verified the effectiveness of QoE collaborative evaluation method based on fuzzy clustering heuristic rules. PMID:27398281

  19. An Exploration of Administrative Heuristics in the United States and the United Kingdom

    ERIC Educational Resources Information Center

    English, Fenwick W.; Bolton, Cheryl L.

    2008-01-01

    This article is a report on a study of the use of heuristics, shortcuts, and rules of thumb by middle-line managers in institutions of higher education in the United States and the United Kingdom. Using a nonprobability convenience sample, the coinvestigators interviewed 13 middle-line managers over 5 months from eight institutions. The results…

  20. Lagrange Multipliers, Adjoint Equations, the Pontryagin Maximum Principle and Heuristic Proofs

    ERIC Educational Resources Information Center

    Ollerton, Richard L.

    2013-01-01

    Deeper understanding of important mathematical concepts by students may be promoted through the (initial) use of heuristic proofs, especially when the concepts are also related back to previously encountered mathematical ideas or tools. The approach is illustrated by use of the Pontryagin maximum principle which is then illuminated by reference to…

  1. Developing Biology Lessons Aimed at Teaching for Understanding: A Domain-Specific Heuristic for Student Teachers

    ERIC Educational Resources Information Center

    Janssen, Fred J. J. M.; Tigelaar, Dineke E. H.; Verloop, Nico

    2009-01-01

    Teaching for understanding requires teachers to organize thought-demanding activities which continually challenge students to apply and extend their prior knowledge. Research shows that student teachers often are unable to develop lessons in teaching for understanding. We explored how a domain-specific heuristic can assist student biology teachers…

  2. Testing Bayesian and heuristic predictions of mass judgments of colliding objects

    PubMed Central

    Sanborn, Adam N.

    2014-01-01

    Mass judgments of colliding objects have been used to explore people's understanding of the physical world because they are ecologically relevant, yet people display biases that are most easily explained by a small set of heuristics. Recent work has challenged the heuristic explanation, by producing the same biases from a model that copes with perceptual uncertainty by using Bayesian inference with a prior based on the correct combination rules from Newtonian mechanics (noisy Newton). Here I test the predictions of the leading heuristic model (Gilden and Proffitt, 1989) against the noisy Newton model using a novel manipulation of the standard mass judgment task: making one of the objects invisible post-collision. The noisy Newton model uses the remaining information to predict above-chance performance, while the leading heuristic model predicts chance performance when one or the other final velocity is occluded. An experiment using two different types of occlusion showed better-than-chance performance and response patterns that followed the predictions of the noisy Newton model. The results demonstrate that people can make sensible physical judgments even when information critical for the judgment is missing, and that a Bayesian model can serve as a guide in these situations. Possible algorithmic-level accounts of this task that more closely correspond to the noisy Newton model are explored. PMID:25206345

  3. Take the First Heuristic, Self-Efficacy, and Decision-Making in Sport

    ERIC Educational Resources Information Center

    Hepler, Teri J.; Feltz, Deborah L.

    2012-01-01

    Can taking the first (TTF) option in decision-making lead to the best decisions in sports contexts? And, is one's decision-making self-efficacy in that context linked to TTF decisions? The purpose of this study was to examine the role of the TTF heuristic and self-efficacy in decision-making on a simulated sports task. Undergraduate and graduate…

  4. A New Heuristic Algorithm for Protein Folding in the HP Model.

    PubMed

    Traykov, Metodi; Angelov, Slav; Yanev, Nicola

    2016-08-01

    This article presents an efficient heuristic for protein folding. The protein folding problem is to predict the compact three-dimensional structure of a protein based on its amino acid sequence. The focus is on an original integer programming model derived from a platform used for Contact Map Overlap problem. PMID:27153764

  5. Heuristics and Biases as Measures of Critical Thinking: Associations with Cognitive Ability and Thinking Dispositions

    ERIC Educational Resources Information Center

    West, Richard F.; Toplak, Maggie E.; Stanovich, Keith E.

    2008-01-01

    In this article, the authors argue that there are a range of effects usually studied within cognitive psychology that are legitimately thought of as aspects of critical thinking: the cognitive biases studied in the heuristics and biases literature. In a study of 793 student participants, the authors found that the ability to avoid these biases was…

  6. Displacements Of Brownian Particles In Terms Of Marian Von Smoluchowski's Heuristic Model

    ERIC Educational Resources Information Center

    Klein, Hermann; Woermann, Dietrich

    2005-01-01

    Albert Einstein's theory of the Brownian motion, Marian von Smoluchowski's heuristic model, and Perrin's experimental results helped to bring the concept of molecules from a state of being a useful hypothesis in chemistry to objects existing in reality. Central to the theory of Brownian motion is the relation between mean particle displacement and…

  7. Relating Local to Global Spatial Knowledge: Heuristic Influence of Local Features on Direction Estimates

    ERIC Educational Resources Information Center

    Phillips, Daniel W.; Montello, Daniel R.

    2015-01-01

    Previous research has examined heuristics--simplified decision-making rules-of-thumb--for geospatial reasoning. This study examined at two locations the influence of beliefs about local coastline orientation on estimated directions to local and distant places; estimates were made immediately or after fifteen seconds. This study goes beyond…

  8. An Approach to Protein Name Extraction Using Heuristics and a Dictionary.

    ERIC Educational Resources Information Center

    Seki, Kazuhiro; Mostafa, Javed

    2003-01-01

    Proposes a method for protein name extraction from biological texts. The method exploits hand-crafted rules based on heuristics and a set of protein names (dictionary). The approach avoids use of natural language processing tools so as to improve processing speed. Evaluation experiments were conducted in terms of: accuracy, generalizability, and…

  9. Academic Freedom in Classroom Speech: A Heuristic Model for U.S. Catholic Higher Education

    ERIC Educational Resources Information Center

    Jacobs, Richard M.

    2010-01-01

    As the nation's Catholic universities and colleges continually clarify their identity, this article examines academic freedom in classroom speech, offering a heuristic model for use as board members, academic administrators, and faculty leaders discuss, evaluate, and judge allegations of misconduct in classroom speech. Focusing upon the practice…

  10. Information Processing and Risk Perception: An Adaptation of the Heuristic-Systematic Model.

    ERIC Educational Resources Information Center

    Trumbo, Craig W.

    2002-01-01

    Describes heuristic-systematic information-processing model and risk perception--the two major conceptual areas of the analysis. Discusses the proposed model, describing the context of the data collections (public health communication involving cancer epidemiology) and providing the results of a set of three replications using the proposed model.…

  11. Design Heuristics in Academic, Corporate, and Military Instruction: More Similar than Different

    ERIC Educational Resources Information Center

    York, Cindy S.; Ertmer, Peggy A.

    2013-01-01

    Despite the fact that the practice of instructional design (ID) began in the U. S. military (Branson et al., 1975; Jeffrey & Bratton-Jeffrey, 2004; Reiser, 2102), there is little known regarding which design and development heuristics military instructional designers deem important to the ID process. The study reported in this article was…

  12. On the Psychology of the Recognition Heuristic: Retrieval Primacy as a Key Determinant of Its Use

    ERIC Educational Resources Information Center

    Pachur, Thorsten; Hertwig, Ralph

    2006-01-01

    The recognition heuristic is a prime example of a boundedly rational mind tool that rests on an evolved capacity, recognition, and exploits environmental structures. When originally proposed, it was conjectured that no other probabilistic cue reverses the recognition-based inference (D. G. Goldstein & G. Gigerenzer, 2002). More recent studies…

  13. Balancing Self-Directed Learning with Expert Mentoring: The Science Writing Heuristic Approach

    ERIC Educational Resources Information Center

    Shelley, Mack; Fostvedt, Luke; Gonwa-Reeves, Christopher; Baenziger, Joan; McGill, Michael; Seefeld, Ashley; Hand, Brian; Therrien, William; Taylor, Jonte; Villanueva, Mary Grace

    2012-01-01

    This study focuses on the implementation of the Science Writing Heuristic (SWH) curriculum (Hand, 2007), which combines current understandings of learning as a cognitive and negotiated process with the techniques of argument-based inquiry, critical thinking skills, and writing to strengthen student outcomes. Success of SWH is dependent on the…

  14. Developing Critical Thinking Skills Using the Science Writing Heuristic in the Chemistry Laboratory

    ERIC Educational Resources Information Center

    Stephenson, N. S.; Sadler-McKnight, N. P.

    2016-01-01

    The Science Writing Heuristic (SWH) laboratory approach is a teaching and learning tool which combines writing, inquiry, collaboration and reflection, and provides scaffolding for the development of critical thinking skills. In this study, the California Critical Thinking Skills Test (CCTST) was used to measure the critical thinking skills of…

  15. The Effect of General Versus Specific Heuristics in Mathematical Problem-Solving Tasks.

    ERIC Educational Resources Information Center

    Smith, James Philip

    This study investigated differences in problem-solving performance following instruction varying in the type of heuristic advice given. The subjects, 176 college students with two years of high school mathematics experience, were provided programed instruction over a three-week period in three topic areas: finite geometry, Boolean algebra, and…

  16. Investigating the Decision Heuristics of Candidate Teachers Who Are Different in Their Responsibility Controls

    ERIC Educational Resources Information Center

    Özen, Yener

    2016-01-01

    In this study, decision heuristics used by individuals with different responsibility controls were investigated. In the research, 370 final grade university students studying at Erzincan University Faculty of Education were included. In order to collect data, Internally Controlled Responsibility-Externally Controlled Responsibility Scale of Özen…

  17. A Scrabble Heuristic Based on Probability That Performs at Championship Level

    NASA Astrophysics Data System (ADS)

    Ramírez, Arturo; Acuña, Francisco González; Romero, Alejandro González; Alquézar, René; Hernández, Enric; Aguilar, Amador Roldán; Olmedo, Ian García

    The game of Scrabble, in its competitive form (one vs. one), has been tackled mostly by using Monte Carlo simulation. Recently [1], Probability Theory (Bayes’ theorem) was used to gain knowledge about the opponents’ tiles; this proved to be a good approach to improve even more Computer Scrabble. We used probability to evaluate Scrabble leaves (rack residues); then using this evaluation, a heuristic function that dictates a move can be constructed. To calculate these probabilities it is necessary to have a lexicon, in our case a Spanish lexicon. To make proper investigations in the domain of Scrabble it is important to have the same lexicon as the one used by humans in official tournaments. We did a huge amount of work to build this free lexicon. In this paper a heuristic function that involves leaves probabilities is given. We have now an engine, Heuri, that uses this heuristic, and we have been able to perform some experiments to test it. The tests include matches against highly expert players; the games played so far give us promising results. For instance, recently a match between the current World Scrabble Champion (in Spanish) and Heuri was played. Heuri defeated the World Champion 6-0 ! Heuri includes a move generator which, using a lot of memory, is faster than using DAWG [2] or GADDAG [3]. Another plan to build a stronger Heuri that combines heuristics using probabilities, opponent modeling and Monte Carlo simulation is also proposed.

  18. Autobiographical Elaboration Reduces Memory Distortion: Cognitive Operations and the Distinctiveness Heuristic

    ERIC Educational Resources Information Center

    McDonough, Ian M.; Gallo, David A.

    2008-01-01

    Retrieval monitoring enhances episodic memory accuracy. For instance, false recognition is reduced when participants base their decisions on more distinctive recollections, a retrieval monitoring process called the distinctiveness heuristic. The experiments reported here tested the hypothesis that autobiographical elaboration during study (i.e.,…

  19. The Lived Experience of Psychotherapists Working with Older Clients: An Heuristic Study

    ERIC Educational Resources Information Center

    Atkins, Dianne; Loewenthal, Del

    2004-01-01

    This paper presents the results of an heuristic study based on the research question: 'How do psychotherapists experience working with older clients?' The question came from the researchers' experience and interest in working with older clients in general practice. It started from the researchers' desire to examine more closely feelings and…

  20. Acquisition of strategies depending on the opponents' competence level.

    PubMed

    Wontorra, H; Krems, J

    1989-01-01

    The development of problem-solving skills from novices to advanced subjects in dependence of the competence level of the opponent is examined in a two-person zero-sum game (Othello). In a repeated-measurement design 18 Ss. (6 Ss in 3 groups) played 10 games against one of three opponent-strategies (implemented on a computer): one "expertlike" strategy, which uses domain specific knowledge and local heuristics (minimax-algorithm with alpha-beta pruning); one "novicelike" strategy, in which global, domain independent problem solving strategies (means-ends analysis, goal-reduction) are implemented; and one strategy, which contradicts the supposed heuristics of the novices, but which results in a "weak" performance (minimization in move-selection). Contrary to our assumptions no significant effects of experience could be verified (win versus loss during single runs). An experience dependent differentiation of global problem solving strategies could not be shown for any of the groups. Neither could a general improving effect of the model for acquiring local, task specific heuristics be proved. PMID:2624531

  1. Neural substrates of similarity and rule-based strategies in judgment

    PubMed Central

    von Helversen, Bettina; Karlsson, Linnea; Rasch, Björn; Rieskamp, Jörg

    2014-01-01

    Making accurate judgments is a core human competence and a prerequisite for success in many areas of life. Plenty of evidence exists that people can employ different judgment strategies to solve identical judgment problems. In categorization, it has been demonstrated that similarity-based and rule-based strategies are associated with activity in different brain regions. Building on this research, the present work tests whether solving two identical judgment problems recruits different neural substrates depending on people's judgment strategies. Combining cognitive modeling of judgment strategies at the behavioral level with functional magnetic resonance imaging (fMRI), we compare brain activity when using two archetypal judgment strategies: a similarity-based exemplar strategy and a rule-based heuristic strategy. Using an exemplar-based strategy should recruit areas involved in long-term memory processes to a larger extent than a heuristic strategy. In contrast, using a heuristic strategy should recruit areas involved in the application of rules to a larger extent than an exemplar-based strategy. Largely consistent with our hypotheses, we found that using an exemplar-based strategy led to relatively higher BOLD activity in the anterior prefrontal and inferior parietal cortex, presumably related to retrieval and selective attention processes. In contrast, using a heuristic strategy led to relatively higher activity in areas in the dorsolateral prefrontal and the temporal-parietal cortex associated with cognitive control and information integration. Thus, even when people solve identical judgment problems, different neural substrates can be recruited depending on the judgment strategy involved. PMID:25360099

  2. Parameter estimation with bio-inspired meta-heuristic optimization: modeling the dynamics of endocytosis

    PubMed Central

    2011-01-01

    Background We address the task of parameter estimation in models of the dynamics of biological systems based on ordinary differential equations (ODEs) from measured data, where the models are typically non-linear and have many parameters, the measurements are imperfect due to noise, and the studied system can often be only partially observed. A representative task is to estimate the parameters in a model of the dynamics of endocytosis, i.e., endosome maturation, reflected in a cut-out switch transition between the Rab5 and Rab7 domain protein concentrations, from experimental measurements of these concentrations. The general parameter estimation task and the specific instance considered here are challenging optimization problems, calling for the use of advanced meta-heuristic optimization methods, such as evolutionary or swarm-based methods. Results We apply three global-search meta-heuristic algorithms for numerical optimization, i.e., differential ant-stigmergy algorithm (DASA), particle-swarm optimization (PSO), and differential evolution (DE), as well as a local-search derivative-based algorithm 717 (A717) to the task of estimating parameters in ODEs. We evaluate their performance on the considered representative task along a number of metrics, including the quality of reconstructing the system output and the complete dynamics, as well as the speed of convergence, both on real-experimental data and on artificial pseudo-experimental data with varying amounts of noise. We compare the four optimization methods under a range of observation scenarios, where data of different completeness and accuracy of interpretation are given as input. Conclusions Overall, the global meta-heuristic methods (DASA, PSO, and DE) clearly and significantly outperform the local derivative-based method (A717). Among the three meta-heuristics, differential evolution (DE) performs best in terms of the objective function, i.e., reconstructing the output, and in terms of convergence. These

  3. Hierarchical multiobjective routing model in Multiprotocol Label Switching networks with two service classes - a Pareto archive strategy

    NASA Astrophysics Data System (ADS)

    Girão-Silva, Rita; Craveirinha, José; Clímaco, João

    2012-05-01

    The article begins by reviewing a two-level hierarchical multicriteria routing model for Multiprotocol Label Switching networks with two service classes (QoS, i.e. with Quality of Service requirements, and Best Effort services) and alternative routing, as well as the foundations of a heuristic resolution approach, previously proposed by the authors. Afterwards a new variant of this heuristic approach, which includes a Pareto archive strategy, is described. In this archive, non-dominated solutions obtained throughout the heuristic are kept. At the end of the main procedure of the heuristic, these solutions are evaluated and a final solution for the routing problem is chosen using a reference point-based approach. The application of this procedure to two test networks will show, with analytic and discrete-event simulation models, that, in certain initial conditions, this approach provides improvements in the final results concerning the top-level objective functions, especially in more 'difficult' situations detected through sensitivity analysis.

  4. A comparative analysis of static and dynamic load balancing strategies

    NASA Technical Reports Server (NTRS)

    Iqbal, M. Ashraf; Bokhari, Shahid H.; Saltz, Joel H.

    1986-01-01

    The problem of uniformly distributing the load of a parallel program over a multiprocessor system was considered. A program was analyzed whose structure permits the computation of the optimal static solution. Then four strategies for load balancing were described and their performance compared. The strategies are: (1) the optimal static assignment algorithm which is guaranteed to yield the best static solution, (2) the static binary dissection method which is very fast but suboptimal, (3) the greedy algorithm, a static fully polynomial time approximation scheme, which estimates the optimal solution to arbitrary accuracy, and (4) the predictive dynamic load balancing heuristic which uses information on the precedence relationships within the program and outperforms any of the static methods. It is also shown that the overhead incurred by the dynamic heuristic is reduced considerably if it is started off with a static assignment provided by either of the three strategies.

  5. Performance tradeoffs in static and dynamic load balancing strategies

    NASA Technical Reports Server (NTRS)

    Iqbal, M. A.; Saltz, J. H.; Bokhart, S. H.

    1986-01-01

    The problem of uniformly distributing the load of a parallel program over a multiprocessor system was considered. A program was analyzed whose structure permits the computation of the optimal static solution. Then four strategies for load balancing were described and their performance compared. The strategies are: (1) the optimal static assignment algorithm which is guaranteed to yield the best static solution, (2) the static binary dissection method which is very fast but sub-optimal, (3) the greedy algorithm, a static fully polynomial time approximation scheme, which estimates the optimal solution to arbitrary accuracy, and (4) the predictive dynamic load balancing heuristic which uses information on the precedence relationships within the program and outperforms any of the static methods. It is also shown that the overhead incurred by the dynamic heuristic is reduced considerably if it is started off with a static assignment provided by either of the other three strategies.

  6. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics.

    PubMed

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system. PMID:26710335

  7. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics

    PubMed Central

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M.

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system. PMID:26710335

  8. Greedy heuristic algorithm for solving series of eee components classification problems*

    NASA Astrophysics Data System (ADS)

    Kazakovtsev, A. L.; Antamoshkin, A. N.; Fedosov, V. V.

    2016-04-01

    Algorithms based on using the agglomerative greedy heuristics demonstrate precise and stable results for clustering problems based on k- means and p-median models. Such algorithms are successfully implemented in the processes of production of specialized EEE components for using in space systems which include testing each EEE device and detection of homogeneous production batches of the EEE components based on results of the tests using p-median models. In this paper, authors propose a new version of the genetic algorithm with the greedy agglomerative heuristic which allows solving series of problems. Such algorithm is useful for solving the k-means and p-median clustering problems when the number of clusters is unknown. Computational experiments on real data show that the preciseness of the result decreases insignificantly in comparison with the initial genetic algorithm for solving a single problem.

  9. The early stop heuristic: A new convergence criterion for K-means

    NASA Astrophysics Data System (ADS)

    Mexicano, A.; Rodríguez, R.; Cervantes, S.; Montes, P.; Jiménez, M.; Almanza, N.; Abrego, A.

    2016-06-01

    In this paper, an enhanced version of the K-Means algorithm that incorporates a new convergence criterion is presented. The largest centroid displacement at each iteration was used as mean to define whether the algorithm stops or not its execution. Computational experiments showed that in general, the Early Stop Heuristic is able to reduce the execution time of the standard version without a significant quality reduction. According to the experimentation, the Early Stop Heuristic reached a time reduction up to 87.06% only a quality reduction of 2.46% for the Transactions dataset, the worst case occurred when the Skin instance was grouped into 200 clusters obtaining a 79.04% in reduction time, and a 4.27% in quality reduction.

  10. Participatory Heuristic Evaluation of the Second Iteration of the eWALL Interface Application.

    PubMed

    Hangaard, Stine; Schaarup, Clara; Hejlesen, Ole K

    2016-01-01

    The number of people having a chronic disease is increasing. Telehealth may provide an alternative to traditional medicine as telehealth solutions have shown to have a positive influence on quality of live and to decrease the number of hospital visits. A new telehealth solution is the eWALL system. Previously, the eWALL interface application has been evaluated using participatory heuristic evaluation (PHE). The previous round of PHE lead to drastic changes of the eWALL interface application. Consequently, a second round of PHE was performed. Five usability experts and two work-domain professionals inspected the eWALL interface application and identified usability problems (n = 384). The work domain professionals had a tendency to use other heuristics than the usability experts highlighting the relevance of using PHE in an interface development process. PMID:27577454

  11. PROOF OF CONCEPT FOR A HUMAN RELIABILITY ANALYSIS METHOD FOR HEURISTIC USABILITY EVALUATION OF SOFTWARE

    SciTech Connect

    Ronald L. Boring; David I. Gertman; Jeffrey C. Joe; Julie L. Marble

    2005-09-01

    An ongoing issue within human-computer interaction (HCI) is the need for simplified or “discount” methods. The current economic slowdown has necessitated innovative methods that are results driven and cost effective. The myriad methods of design and usability are currently being cost-justified, and new techniques are actively being explored that meet current budgets and needs. Recent efforts in human reliability analysis (HRA) are highlighted by the ten-year development of the Standardized Plant Analysis Risk HRA (SPAR-H) method. The SPAR-H method has been used primarily for determining humancentered risk at nuclear power plants. The SPAR-H method, however, shares task analysis underpinnings with HCI. Despite this methodological overlap, there is currently no HRA approach deployed in heuristic usability evaluation. This paper presents an extension of the existing SPAR-H method to be used as part of heuristic usability evaluation in HCI.

  12. Judgement heuristics and bias in evidence interpretation: The effects of computer generated exhibits.

    PubMed

    Norris, Gareth

    2015-01-01

    The increasing use of multi-media applications, trial presentation software and computer generated exhibits (CGE) has raised questions as to the potential impact of the use of presentation technology on juror decision making. A significant amount of the commentary on the manner in which CGE exerts legal influence is largely anecdotal; empirical examinations too are often devoid of established theoretical rationalisations. This paper will examine a range of established judgement heuristics (for example, the attribution error, representativeness, simulation), in order to establish their appropriate application for comprehending legal decisions. Analysis of both past cases and empirical studies will highlight the potential for heuristics and biases to be restricted or confounded by the use of CGE. The paper will conclude with some wider discussion on admissibility, access to justice, and emerging issues in the use of multi-media in court. PMID:26341308

  13. Scatter search heuristic for least-cost design of water distribution networks

    NASA Astrophysics Data System (ADS)

    Lin, Min-Der; Liu, Yu-Hsin; Liu, Gee-Fon; Chu, Chien-Wei

    2007-10-01

    The optimization problems of water distribution networks are complex, multi-modal and discrete-variable problems that cannot be easily solved with conventional optimization algorithms. Heuristic algorithms such as genetic algorithms, simulated annealing, tabu search and ant colony optimization have been extensively employed over the last decade. This article proposed an optimization procedure based on the scatter search (SS) framework, which is also a heuristic algorithm, to obtain the least-cost designs of three well-known looped water distribution networks (two-loop, Hanoi and New York networks). The computational results obtained with the three benchmark instances indicate that SS is able to find solutions comparable to those provided by some of the most competitive algorithms published in the literature.

  14. RSQRT: AN HEURISTIC FOR ESTIMATING THE NUMBER OF CLUSTERS TO REPORT.

    PubMed

    Carlis, John; Bruso, Kelsey

    2012-03-01

    Clustering can be a valuable tool for analyzing large datasets, such as in e-commerce applications. Anyone who clusters must choose how many item clusters, K, to report. Unfortunately, one must guess at K or some related parameter. Elsewhere we introduced a strongly-supported heuristic, RSQRT, which predicts K as a function of the attribute or item count, depending on attribute scales. We conducted a second analysis where we sought confirmation of the heuristic, analyzing data sets from theUCImachine learning benchmark repository. For the 25 studies where sufficient detail was available, we again found strong support. Also, in a side-by-side comparison of 28 studies, RSQRT best-predicted K and the Bayesian information criterion (BIC) predicted K are the same. RSQRT has a lower cost of O(log log n) versus O(n(2)) for BIC, and is more widely applicable. Using RSQRT prospectively could be much better than merely guessing. PMID:22773923

  15. A heuristic to bandwidth allocation and sales limit setting for Internet service providers

    NASA Astrophysics Data System (ADS)

    You, Peng Sheng; Hsieh, Yi-Chih; Ikuta, Seizo

    2012-11-01

    When requesting on-line, many subscribers have experienced the situation in which their on-line requests are denied or their connection speeds are far below their contracted speed limits. This bad customer experience may result from the situation in which Internet service providers (ISPs) accept customers' subscriptions without setting sales limits. As subscribers are potential on-line users, controlling the number of subscribers can be considered as an approach to overcome this problem. The goal of this article is to develop decisions to maximise revenues of ISPs while guaranteeing the expected service quality for distinct service classes. The developed model was a resource constrained nonlinear integer problem, and a heuristic approach was provided to acquire a near-optimal solution. Limited numerical results showed that the proposed heuristic approach can solve this problem efficiently.

  16. Analysis of utility-theoretic heuristics for intelligent adaptive network routing

    SciTech Connect

    Mikler, A.R.; Honavar, V.; Wong, J.S.K.

    1996-12-31

    Utility theory offers an elegant and powerful theoretical framework for design and analysis of autonomous adaptive communication networks. Routing of messages in such networks presents a real-time instance of a multi-criterion optimization problem in a dynamic and uncertain environment. In this paper, we incrementally develop a set of heuristic decision functions that can be used to guide messages along a near-optimal (e.g., minimum delay) path in a large network. We present an analysis of properties of such heuristics under a set of simplifying assumptions about the network topology and load dynamics and identify the conditions under which they are guaranteed to route messages along an optimal path. The paper concludes with a discussion of the relevance of the theoretical results presented in the paper to the design of intelligent autonomous adaptive communication networks and an outline of some directions of future research.

  17. A Library of Local Search Heuristics for the Vehicle Routing Problem

    SciTech Connect

    Groer, Christopher S; Golden, Bruce; Edward, Wasil

    2010-01-01

    The vehicle routing problem (VRP) is a difficult and well-studied combinatorial optimization problem. Real-world instances of the VRP can contain hundreds and even thousands of customer locations and can involve many complicating constraints, necessitating the use of heuristic methods. We present a software library of local search heuristics that allow one to quickly generate good solutions to VRP instances. The code has a logical, object-oriented design and uses efficient data structures to store and modify solutions. The core of the library is the implementation of seven local search operators that share a similar interface and are designed to be extended to handle additional options with minimal code change. The code is well-documented, is straightforward to compile, and is freely available for download at http://sites.google.com/site/vrphlibrary/ . The distribution of the code contains several applications that can be used to generate solutions to instances of the capacitated VRP.

  18. An Empirical Comparison of Seven Iterative and Evolutionary Function Optimization Heuristics

    NASA Technical Reports Server (NTRS)

    Baluja, Shumeet

    1995-01-01

    This report is a repository of the results obtained from a large scale empirical comparison of seven iterative and evolution-based optimization heuristics. Twenty-seven static optimization problems, spanning six sets of problem classes which are commonly explored in genetic algorithm literature, are examined. The problem sets include job-shop scheduling, traveling salesman, knapsack, binpacking, neural network weight optimization, and standard numerical optimization. The search spaces in these problems range from 2368 to 22040. The results indicate that using genetic algorithms for the optimization of static functions does not yield a benefit, in terms of the final answer obtained, over simpler optimization heuristics. Descriptions of the algorithms tested and the encodings of the problems are described in detail for reproducibility.

  19. A simple, heuristic derivation of our ‘no backreaction’ results

    NASA Astrophysics Data System (ADS)

    Green, Stephen R.; Wald, Robert M.

    2016-06-01

    We provide a simple discussion of our results on the backreaction effects of density inhomogeneities in cosmology without mentioning one-parameter families or weak limits. Emphasis is placed on the manner in which ‘averaging’ is done and the fact that one is solving Einstein’s equation. The key assumptions and results that we rigorously derived within our original mathematical framework are thereby explained in a heuristic way.

  20. Join routing and dimensioning heuristic for dynamic WDM optical mesh networks with wavelength conversion

    NASA Astrophysics Data System (ADS)

    Vallejos, Reinaldo; Jara, Nicolas

    2014-06-01

    Network operators face the challenge of solving routing and wavelength dimensioning problems while aiming to simultaneously minimize the network cost and ensure that the network performance meets the level established in the Service Level Agreement (SLA). We call this problem the routing and wavelength dimensioning (R&WD) problem. Finding the optimal solution to this problem is hard. Thus, in practice, heuristics are used to obtain a good solution with low computational complexity.

  1. An approach to combining heuristic and qualitative reasoning in an expert system

    NASA Technical Reports Server (NTRS)

    Jiang, Wei-Si; Han, Chia Yung; Tsai, Lian Cheng; Wee, William G.

    1988-01-01

    An approach to combining the heuristic reasoning from shallow knowledge and the qualitative reasoning from deep knowledge is described. The shallow knowledge is represented in production rules and under the direct control of the inference engine. The deep knowledge is represented in frames, which may be put in a relational DataBase Management System. This approach takes advantage of both reasoning schemes and results in improved efficiency as well as expanded problem solving ability.

  2. Graph coloring heuristics for solving examination timetabling problem at Universiti Utara Malaysia

    NASA Astrophysics Data System (ADS)

    Abdul-Rahman, Syariza; Sobri, Nur Suriani; Omar, Mohd Faizal; Benjamin, Aida Mauziah; Ramli, Razamin

    2014-12-01

    Examination timetabling is a well-studied combinatorial optimization problem involving scheduling a set of examinations into a restricted number of time-slots while satisfying a defined set of constraints. This paper presents a real-world, capacitated examination timetabling problem from Universiti Utara Malaysia (UUM), Malaysia. This dataset differs from the others reported in the literature with respect to its size, complexity and constraints. Until recently, examination timetabling in UUM is done manually with a little guidance from spreadsheet computer software for checking clashes. The propriety system is unable to do the examination timetabling automatically. Besides, the introduced datasets also consider a new constraint that has never been modeled before in timetabling literature, which is lecturer's preference. Moreover, splitting examination across several rooms and a number of hard constraints such as no mixed duration of examination within individual periods, clashes free schedule and room capacity requirement are also need to be adhered. These constraints provide an additional challenge in solving the examination timetabling problem, mainly at UUM. In this paper, graph coloring heuristics are employed to schedule examinations at each step during timetable construction. We used the concept of bin packing heuristics to assign examination to room with respect to the capacity. Since this is a new dataset and no solutions have been published in the literature yet, we only compare the results with an existing manual solution. It is found that the proposed constructive heuristic able to produce good quality solution for the tested problem. The proposed graph coloring heuristics are proved to be superior to the current method employed by the University and found to perform well in comparison.

  3. Experimental evidence for convergent evolution of maternal care heuristics in industrialized and small-scale populations

    PubMed Central

    Kushnick, Geoff; Hanowell, Ben; Kim, Jun-Hong; Langstieh, Banrida; Magnano, Vittorio; Oláh, Katalin

    2015-01-01

    Maternal care decision rules should evolve responsiveness to factors impinging on the fitness pay-offs of care. Because the caretaking environments common in industrialized and small-scale societies vary in predictable ways, we hypothesize that heuristics guiding maternal behaviour will also differ between these two types of populations. We used a factorial vignette experiment to elicit third-party judgements about likely caretaking decisions of a hypothetical mother and her child when various fitness-relevant factors (maternal age and access to resources, and offspring age, sex and quality) were varied systematically in seven populations—three industrialized and four small-scale. Despite considerable variation in responses, we found that three of five main effects, and the two severity effects, exhibited statistically significant industrialized/ small-scale population differences. All differences could be explained as adaptive solutions to industrialized versus small-scale caretaking environments. Further, we found gradients in the relationship between the population-specific estimates and national-level socio-economic indicators, further implicating important aspects of the variation in industrialized and small-scale caretaking environments in shaping heuristics. Although there is mounting evidence for a genetic component to human maternal behaviour, there is no current evidence for interpopulation variation in candidate genes. We nonetheless suggest that heuristics guiding maternal behaviour in diverse societies emerge via convergent evolution in response to similar selective pressures. PMID:26543577

  4. Neural model of gene regulatory network: a survey on supportive meta-heuristics.

    PubMed

    Biswas, Surama; Acharyya, Sriyankar

    2016-06-01

    Gene regulatory network (GRN) is produced as a result of regulatory interactions between different genes through their coded proteins in cellular context. Having immense importance in disease detection and drug finding, GRN has been modelled through various mathematical and computational schemes and reported in survey articles. Neural and neuro-fuzzy models have been the focus of attraction in bioinformatics. Predominant use of meta-heuristic algorithms in training neural models has proved its excellence. Considering these facts, this paper is organized to survey neural modelling schemes of GRN and the efficacy of meta-heuristic algorithms towards parameter learning (i.e. weighting connections) within the model. This survey paper renders two different structure-related approaches to infer GRN which are global structure approach and substructure approach. It also describes two neural modelling schemes, such as artificial neural network/recurrent neural network based modelling and neuro-fuzzy modelling. The meta-heuristic algorithms applied so far to learn the structure and parameters of neutrally modelled GRN have been reviewed here. PMID:27048512

  5. Applied tagmemics: A heuristic approach to the use of graphic aids in technical writing

    NASA Technical Reports Server (NTRS)

    Brownlee, P. P.; Kirtz, M. K.

    1981-01-01

    In technical report writing, two needs which must be met if reports are to be useable by an audience are the language needs and the technical needs of that particular audience. A heuristic analysis helps to decide the most suitable format for information; that is, whether the information should be presented verbally or visually. The report writing process should be seen as an organic whole which can be divided and subdivided according to the writer's purpose, but which always functions as a totality. The tagmemic heuristic, because it itself follows a process of deconstructing and reconstructing information, lends itself to being a useful approach to the teaching of technical writing. By applying the abstract questions this heuristic asks to specific parts of the report. The language and technical needs of the audience are analyzed by examining the viability of the solution within the givens of the corporate structure, and by deciding which graphic or verbal format will best suit the writer's purpose. By following such a method, answers which are both specific and thorough in their range of application are found.

  6. Reconciliation of Decision-Making Heuristics Based on Decision Trees Topologies and Incomplete Fuzzy Probabilities Sets

    PubMed Central

    Doubravsky, Karel; Dohnal, Mirko

    2015-01-01

    Complex decision making tasks of different natures, e.g. economics, safety engineering, ecology and biology, are based on vague, sparse, partially inconsistent and subjective knowledge. Moreover, decision making economists / engineers are usually not willing to invest too much time into study of complex formal theories. They require such decisions which can be (re)checked by human like common sense reasoning. One important problem related to realistic decision making tasks are incomplete data sets required by the chosen decision making algorithm. This paper presents a relatively simple algorithm how some missing III (input information items) can be generated using mainly decision tree topologies and integrated into incomplete data sets. The algorithm is based on an easy to understand heuristics, e.g. a longer decision tree sub-path is less probable. This heuristic can solve decision problems under total ignorance, i.e. the decision tree topology is the only information available. But in a practice, isolated information items e.g. some vaguely known probabilities (e.g. fuzzy probabilities) are usually available. It means that a realistic problem is analysed under partial ignorance. The proposed algorithm reconciles topology related heuristics and additional fuzzy sets using fuzzy linear programming. The case study, represented by a tree with six lotteries and one fuzzy probability, is presented in details. PMID:26158662

  7. Reconciliation of Decision-Making Heuristics Based on Decision Trees Topologies and Incomplete Fuzzy Probabilities Sets.

    PubMed

    Doubravsky, Karel; Dohnal, Mirko

    2015-01-01

    Complex decision making tasks of different natures, e.g. economics, safety engineering, ecology and biology, are based on vague, sparse, partially inconsistent and subjective knowledge. Moreover, decision making economists / engineers are usually not willing to invest too much time into study of complex formal theories. They require such decisions which can be (re)checked by human like common sense reasoning. One important problem related to realistic decision making tasks are incomplete data sets required by the chosen decision making algorithm. This paper presents a relatively simple algorithm how some missing III (input information items) can be generated using mainly decision tree topologies and integrated into incomplete data sets. The algorithm is based on an easy to understand heuristics, e.g. a longer decision tree sub-path is less probable. This heuristic can solve decision problems under total ignorance, i.e. the decision tree topology is the only information available. But in a practice, isolated information items e.g. some vaguely known probabilities (e.g. fuzzy probabilities) are usually available. It means that a realistic problem is analysed under partial ignorance. The proposed algorithm reconciles topology related heuristics and additional fuzzy sets using fuzzy linear programming. The case study, represented by a tree with six lotteries and one fuzzy probability, is presented in details. PMID:26158662

  8. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect Reciprocity.

    PubMed

    Whitaker, Roger M; Colombo, Gualtiero B; Allen, Stuart M; Dunbar, Robin I M

    2016-01-01

    Cooperation is a fundamental human trait but our understanding of how it functions remains incomplete. Indirect reciprocity is a particular case in point, where one-shot donations are made to unrelated beneficiaries without any guarantee of payback. Existing insights are largely from two independent perspectives: i) individual-level cognitive behaviour in decision making, and ii) identification of conditions that favour evolution of cooperation. We identify a fundamental connection between these two areas by examining social comparison as a means through which indirect reciprocity can evolve. Social comparison is well established as an inherent human disposition through which humans navigate the social world by self-referential evaluation of others. Donating to those that are at least as reputable as oneself emerges as a dominant heuristic, which represents aspirational homophily. This heuristic is found to be implicitly present in the current knowledge of conditions that favour indirect reciprocity. The effective social norms for updating reputation are also observed to support this heuristic. We hypothesise that the cognitive challenge associated with social comparison has contributed to cerebral expansion and the disproportionate human brain size, consistent with the social complexity hypothesis. The findings have relevance for the evolution of autonomous systems that are characterised by one-shot interactions. PMID:27515119

  9. A heuristic based fuzzy reasoning approach for distribution system service restoration

    SciTech Connect

    Hsu, Y.Y.; Kuo, H.C. . Dept. of Electrical Engineering)

    1994-04-01

    A fuzzy reasoning approach is proposed for the service restoration of a distribution system. After the location of a fault has been identified and the faulted zone has been isolated, it is important for the operators to reach a proper service restoration plan in order to restore the electricity service outside the faulted zone. The operators tend to use their past experience and heuristic rules to devise such a restoration plan because it must satisfy a lot of practical needs and objectives such as minimal number of switching operations, no interrupted customers, no overloaded components,..., etc. Thus, service restoration is a multiple-objective problem with some objectives contradictory to each other. In most cases, compromise must be made in order to reach a plan which meets the operators' practical needs. In addition, the operators' needs and heuristic rules are often expressed in imprecise linguistic terms. In this paper, fuzzy set notation is employed to deal with these imprecise linguistic variables and a set of fuzzy reasoning procedures are developed to implement the operators' heuristic rules. These procedures can be employed to solve the multiple-objective problem of service restoration described in imprecise linguistic variables. To demonstrate the effectiveness of the proposed fuzzy reasoning approach, service restoration on a distribution system within the service area of Taipei West District Office of Taiwan Power Company is examined. It is found that a proper restoration plan can be reached very efficiently by the proposed approach.

  10. Anticipation and Choice Heuristics in the Dynamic Consumption of Pain Relief

    PubMed Central

    Story, Giles W.; Vlaev, Ivo; Dayan, Peter; Seymour, Ben; Darzi, Ara; Dolan, Raymond J.

    2015-01-01

    Humans frequently need to allocate resources across multiple time-steps. Economic theory proposes that subjects do so according to a stable set of intertemporal preferences, but the computational demands of such decisions encourage the use of formally less competent heuristics. Few empirical studies have examined dynamic resource allocation decisions systematically. Here we conducted an experiment involving the dynamic consumption over approximately 15 minutes of a limited budget of relief from moderately painful stimuli. We had previously elicited the participants’ time preferences for the same painful stimuli in one-off choices, allowing us to assess self-consistency. Participants exhibited three characteristic behaviors: saving relief until the end, spreading relief across time, and early spending, of which the last was markedly less prominent. The likelihood that behavior was heuristic rather than normative is suggested by the weak correspondence between one-off and dynamic choices. We show that the consumption choices are consistent with a combination of simple heuristics involving early-spending, spreading or saving of relief until the end, with subjects predominantly exhibiting the last two. PMID:25793302

  11. Experimental evidence for convergent evolution of maternal care heuristics in industrialized and small-scale populations.

    PubMed

    Kushnick, Geoff; Hanowell, Ben; Kim, Jun-Hong; Langstieh, Banrida; Magnano, Vittorio; Oláh, Katalin

    2015-06-01

    Maternal care decision rules should evolve responsiveness to factors impinging on the fitness pay-offs of care. Because the caretaking environments common in industrialized and small-scale societies vary in predictable ways, we hypothesize that heuristics guiding maternal behaviour will also differ between these two types of populations. We used a factorial vignette experiment to elicit third-party judgements about likely caretaking decisions of a hypothetical mother and her child when various fitness-relevant factors (maternal age and access to resources, and offspring age, sex and quality) were varied systematically in seven populations-three industrialized and four small-scale. Despite considerable variation in responses, we found that three of five main effects, and the two severity effects, exhibited statistically significant industrialized/ small-scale population differences. All differences could be explained as adaptive solutions to industrialized versus small-scale caretaking environments. Further, we found gradients in the relationship between the population-specific estimates and national-level socio-economic indicators, further implicating important aspects of the variation in industrialized and small-scale caretaking environments in shaping heuristics. Although there is mounting evidence for a genetic component to human maternal behaviour, there is no current evidence for interpopulation variation in candidate genes. We nonetheless suggest that heuristics guiding maternal behaviour in diverse societies emerge via convergent evolution in response to similar selective pressures. PMID:26543577

  12. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect Reciprocity

    PubMed Central

    Whitaker, Roger M.; Colombo, Gualtiero B.; Allen, Stuart M.; Dunbar, Robin I. M.

    2016-01-01

    Cooperation is a fundamental human trait but our understanding of how it functions remains incomplete. Indirect reciprocity is a particular case in point, where one-shot donations are made to unrelated beneficiaries without any guarantee of payback. Existing insights are largely from two independent perspectives: i) individual-level cognitive behaviour in decision making, and ii) identification of conditions that favour evolution of cooperation. We identify a fundamental connection between these two areas by examining social comparison as a means through which indirect reciprocity can evolve. Social comparison is well established as an inherent human disposition through which humans navigate the social world by self-referential evaluation of others. Donating to those that are at least as reputable as oneself emerges as a dominant heuristic, which represents aspirational homophily. This heuristic is found to be implicitly present in the current knowledge of conditions that favour indirect reciprocity. The effective social norms for updating reputation are also observed to support this heuristic. We hypothesise that the cognitive challenge associated with social comparison has contributed to cerebral expansion and the disproportionate human brain size, consistent with the social complexity hypothesis. The findings have relevance for the evolution of autonomous systems that are characterised by one-shot interactions. PMID:27515119

  13. Anticipation and choice heuristics in the dynamic consumption of pain relief.

    PubMed

    Story, Giles W; Vlaev, Ivo; Dayan, Peter; Seymour, Ben; Darzi, Ara; Dolan, Raymond J

    2015-03-01

    Humans frequently need to allocate resources across multiple time-steps. Economic theory proposes that subjects do so according to a stable set of intertemporal preferences, but the computational demands of such decisions encourage the use of formally less competent heuristics. Few empirical studies have examined dynamic resource allocation decisions systematically. Here we conducted an experiment involving the dynamic consumption over approximately 15 minutes of a limited budget of relief from moderately painful stimuli. We had previously elicited the participants' time preferences for the same painful stimuli in one-off choices, allowing us to assess self-consistency. Participants exhibited three characteristic behaviors: saving relief until the end, spreading relief across time, and early spending, of which the last was markedly less prominent. The likelihood that behavior was heuristic rather than normative is suggested by the weak correspondence between one-off and dynamic choices. We show that the consumption choices are consistent with a combination of simple heuristics involving early-spending, spreading or saving of relief until the end, with subjects predominantly exhibiting the last two. PMID:25793302

  14. Fitness landscapes, heuristics and technological paradigms: A critique on random search models in evolutionary economics

    NASA Astrophysics Data System (ADS)

    Frenken, Koen

    2001-06-01

    The biological evolution of complex organisms, in which the functioning of genes is interdependent, has been analyzed as "hill-climbing" on NK fitness landscapes through random mutation and natural selection. In evolutionary economics, NK fitness landscapes have been used to simulate the evolution of complex technological systems containing elements that are interdependent in their functioning. In these models, economic agents randomly search for new technological design by trial-and-error and run the risk of ending up in sub-optimal solutions due to interdependencies between the elements in a complex system. These models of random search are legitimate for reasons of modeling simplicity, but remain limited as these models ignore the fact that agents can apply heuristics. A specific heuristic is one that sequentially optimises functions according to their ranking by users of the system. To model this heuristic, a generalized NK-model is developed. In this model, core elements that influence many functions can be distinguished from peripheral elements that affect few functions. The concept of paradigmatic search can then be analytically defined as search that leaves core elements in tact while concentrating on improving functions by mutation of peripheral elements.

  15. Interplay of approximate planning strategies.

    PubMed

    Huys, Quentin J M; Lally, Níall; Faulkner, Paul; Eshel, Neir; Seifritz, Erich; Gershman, Samuel J; Dayan, Peter; Roiser, Jonathan P

    2015-03-10

    Humans routinely formulate plans in domains so complex that even the most powerful computers are taxed. To do so, they seem to avail themselves of many strategies and heuristics that efficiently simplify, approximate, and hierarchically decompose hard tasks into simpler subtasks. Theoretical and cognitive research has revealed several such strategies; however, little is known about their establishment, interaction, and efficiency. Here, we use model-based behavioral analysis to provide a detailed examination of the performance of human subjects in a moderately deep planning task. We find that subjects exploit the structure of the domain to establish subgoals in a way that achieves a nearly maximal reduction in the cost of computing values of choices, but then combine partial searches with greedy local steps to solve subtasks, and maladaptively prune the decision trees of subtasks in a reflexive manner upon encountering salient losses. Subjects come idiosyncratically to favor particular sequences of actions to achieve subgoals, creating novel complex actions or "options." PMID:25675480

  16. Comparing the performance of expert user heuristics and an integer linear program in aircraft carrier deck operations.

    PubMed

    Ryan, Jason C; Banerjee, Ashis Gopal; Cummings, Mary L; Roy, Nicholas

    2014-06-01

    Planning operations across a number of domains can be considered as resource allocation problems with timing constraints. An unexplored instance of such a problem domain is the aircraft carrier flight deck, where, in current operations, replanning is done without the aid of any computerized decision support. Rather, veteran operators employ a set of experience-based heuristics to quickly generate new operating schedules. These expert user heuristics are neither codified nor evaluated by the United States Navy; they have grown solely from the convergent experiences of supervisory staff. As unmanned aerial vehicles (UAVs) are introduced in the aircraft carrier domain, these heuristics may require alterations due to differing capabilities. The inclusion of UAVs also allows for new opportunities for on-line planning and control, providing an alternative to the current heuristic-based replanning methodology. To investigate these issues formally, we have developed a decision support system for flight deck operations that utilizes a conventional integer linear program-based planning algorithm. In this system, a human operator sets both the goals and constraints for the algorithm, which then returns a proposed schedule for operator approval. As a part of validating this system, the performance of this collaborative human-automation planner was compared with that of the expert user heuristics over a set of test scenarios. The resulting analysis shows that human heuristics often outperform the plans produced by an optimization algorithm, but are also often more conservative. PMID:23934675

  17. The cellular mastermind(?) – Mechanotransduction and the nucleus

    PubMed Central

    Kaminski, Ashley; Fedorchak, Gregory R.; Lammerding, Jan

    2015-01-01

    Cells respond to mechanical stimulation by activation of specific signaling pathways and genes that allow the cell to adapt to its dynamic physical environment. How cells sense the various mechanical inputs and translate them into biochemical signals remains an area of active investigation. Recent reports suggest that the cell nucleus may be directly implicated in this cellular mechanotransduction process. In this chapter, we discuss how forces applied to the cell surface and cytoplasm induce changes in nuclear structure and organization, which could directly affect gene expression, while also highlighting the complex interplay between nuclear structural proteins and transcriptional regulators that may further modulate mechanotransduction signaling. Taken together, these findings paint a picture of the nucleus as a central hub in cellular mechanotransduction—both structurally and biochemically—with important implications in physiology and disease. PMID:25081618

  18. Ernst Rüdin: Hitler's Racial Hygiene Mastermind.

    PubMed

    Joseph, Jay; Wetzel, Norbert A

    2013-01-01

    Ernst Rüdin (1874-1952) was the founder of psychiatric genetics and was also a founder of the German racial hygiene movement. Throughout his long career he played a major role in promoting eugenic ideas and policies in Germany, including helping formulate the 1933 Nazi eugenic sterilization law and other governmental policies directed against the alleged carriers of genetic defects. In the 1940s Rüdin supported the killing of children and mental patients under a Nazi program euphemistically called "Euthanasia." The authors document these crimes and discuss their implications, and also present translations of two publications Rüdin co-authored in 1938 showing his strong support for Hitler and his policies. The authors also document what they see as revisionist historical accounts by leading psychiatric genetic authors. They outline three categories of contemporary psychiatric genetic accounts of Rüdin and his work: (A) those who write about German psychiatric genetics in the Nazi period, but either fail to mention Rüdin at all, or cast him in a favorable light; (B) those who acknowledge that Rüdin helped promote eugenic sterilization and/or may have worked with the Nazis, but generally paint a positive picture of Rüdin's research and fail to mention his participation in the "euthanasia" killing program; and (C) those who have written that Rüdin committed and supported unspeakable atrocities. The authors conclude by calling on the leaders of psychiatric genetics to produce a detailed and complete account of their field's history, including all of the documented crimes committed by Rüdin and his associates. PMID:23180223

  19. Heuristic pairwise alignment of de Bruijn graphs to facilitate simultaneous transcript discovery in related organisms from RNA-Seq data

    PubMed Central

    2015-01-01

    Background The advance of high-throughput sequencing has made it possible to obtain new transcriptomes and study splicing mechanisms in non-model organisms. In these studies, there is often a need to investigate the transcriptomes of two related organisms at the same time in order to find the similarities and differences between them. The traditional approach to address this problem is to perform de novo transcriptome assemblies to obtain predicted transcripts for these organisms independently and then employ similarity comparison algorithms to study them. Results Instead of obtaining predicted transcripts for these organisms separately from the intermediate de Bruijn graph structures employed by de novo transcriptome assembly algorithms, we develop an algorithm to allow direct comparisons between paths in two de Bruijn graphs by first enumerating short paths in both graphs, and iteratively extending paths in one graph that have high similarity to paths in the other graph to obtain longer corresponding paths between the two graphs. These paths represent predicted transcripts that are present in both organisms. We show that our algorithm recovers significantly more shared transcripts than traditional approaches by applying it to simultaneously recover transcripts in mouse against rat and in mouse against human from publicly available RNA-Seq libraries. Our strategy utilizes sequence similarity information within the paths that is often more reliable than coverage information. Conclusions Our approach generalizes the pairwise sequence alignment problem to allow the input to be non-linear structures, and provides a heuristic to reliably recover similar paths from the two structures. Our algorithm allows detailed investigation of the similarities and differences in alternative splicing between the two organisms at both the sequence and structure levels, even in the absence of reference transcriptomes or a closely related model organism. PMID:26576690

  20. Heuristic Evaluation of Ehealth Interventions: Establishing Standards That Relate to the Therapeutic Process Perspective.

    PubMed

    Baumel, Amit; Muench, Fred

    2016-01-01

    In recent years, the number of available eHealth interventions aimed at treating behavioral and mental health challenges has been growing. From the perspective of health care providers, there is a need for eHealth interventions to be evaluated prior to clinical trials and for the limited resources allocated to empirical research to be invested in the most promising products. Following a literature review, a gap was found in the availability of eHealth interventions evaluation principles related to the patient experience of the therapeutic process. This paper introduces principles and concepts for the evaluation of eHealth interventions developed as a first step in a process to outline general evaluation guidelines that relate to the clinical context from health care providers' perspective. Our approach was to conduct a review of literature that relates to the examination of eHealth interventions. We identified the literature that was most relevant to our study and used it to define guidelines that relate to the clinical context. We then compiled a list of heuristics we found to be useful for the evaluation of eHealth intervention products' suitability for empirical examination. Four heuristics were identified with respect to the therapeutic process: (1) the product's ease of use (ie, usability), (2) the eHealth intervention's compatibility with the clinical setting, (3) the presence of tools that make it easier for the user to engage in therapeutic activities, and (4) the provision of a feasible therapeutic pathway to growth. We then used this set of heuristics to conduct a detailed examination of MyFitnessPal. This line of work could help to set the bar higher for product developers and to inform health care providers about preferred eHealth intervention designs. PMID:26764209

  1. Pain as a fact and heuristic: how pain neuroimaging illuminates moral dimensions of law.

    PubMed

    Pustilnik, Amanda C

    2012-05-01

    In legal domains ranging from tort to torture, pain and its degree do important definitional work by delimiting boundaries of lawfulness and of entitlements. Yet, for all the work done by pain as a term in legal texts and practice, it has a confounding lack of external verifiability. Now, neuroimaging is rendering pain and myriad other subjective states at least partly ascertainable. This emerging ability to ascertain and quantify subjective states is prompting a "hedonic" or a "subjectivist" turn in legal scholarship, which has sparked a vigorous debate as to whether the quantification of subjective states might affect legal theory and practice. Subjectivists contend that much values-talk in law has been a necessary but poor substitute for quantitative determinations of subjective states--determinations that will be possible in the law's "experiential future." This Article argues the converse: that pain discourse in law frequently is a heuristic for values. Drawing on interviews and laboratory visits with neuroimaging researchers, this Article shows current and in-principle limitations of pain quantification through neuroimaging. It then presents case studies on torture-murder, torture, the death penalty, and abortion to show the largely heuristic role of pain discourse in law. Introducing the theory of "embodied morality," the Article describes how moral conceptions of rights and duties are informed by human physicality and constrained by the limits of empathic identification. Pain neuroimaging helps reveal this dual factual and heuristic nature of pain in the law, and thus itself points to the translational work required for neuroimaging to influence, much less transform, legal practice and doctrine. PMID:22754972

  2. Walking tree heuristics for biological string alignment, gene location, and phylogenies

    NASA Astrophysics Data System (ADS)

    Cull, P.; Holloway, J. L.; Cavener, J. D.

    1999-03-01

    Basic biological information is stored in strings of nucleic acids (DNA, RNA) or amino acids (proteins). Teasing out the meaning of these strings is a central problem of modern biology. Matching and aligning strings brings out their shared characteristics. Although string matching is well-understood in the edit-distance model, biological strings with transpositions and inversions violate this model's assumptions. We propose a family of heuristics called walking trees to align biologically reasonable strings. Both edit-distance and walking tree methods can locate specific genes within a large string when the genes' sequences are given. When we attempt to match whole strings, the walking tree matches most genes, while the edit-distance method fails. We also give examples in which the walking tree matches substrings even if they have been moved or inverted. The edit-distance method was not designed to handle these problems. We include an example in which the walking tree "discovered" a gene. Calculating scores for whole genome matches gives a method for approximating evolutionary distance. We show two evolutionary trees for the picornaviruses which were computed by the walking tree heuristic. Both of these trees show great similarity to previously constructed trees. The point of this demonstration is that WHOLE genomes can be matched and distances calculated. The first tree was created on a Sequent parallel computer and demonstrates that the walking tree heuristic can be efficiently parallelized. The second tree was created using a network of work stations and demonstrates that there is suffient parallelism in the phylogenetic tree calculation that the sequential walking tree can be used effectively on a network.

  3. Heuristic Evaluation of Ehealth Interventions: Establishing Standards That Relate to the Therapeutic Process Perspective

    PubMed Central

    Muench, Fred

    2016-01-01

    In recent years, the number of available eHealth interventions aimed at treating behavioral and mental health challenges has been growing. From the perspective of health care providers, there is a need for eHealth interventions to be evaluated prior to clinical trials and for the limited resources allocated to empirical research to be invested in the most promising products. Following a literature review, a gap was found in the availability of eHealth interventions evaluation principles related to the patient experience of the therapeutic process. This paper introduces principles and concepts for the evaluation of eHealth interventions developed as a first step in a process to outline general evaluation guidelines that relate to the clinical context from health care providers’ perspective. Our approach was to conduct a review of literature that relates to the examination of eHealth interventions. We identified the literature that was most relevant to our study and used it to define guidelines that relate to the clinical context. We then compiled a list of heuristics we found to be useful for the evaluation of eHealth intervention products’ suitability for empirical examination. Four heuristics were identified with respect to the therapeutic process: (1) the product’s ease of use (ie, usability), (2) the eHealth intervention’s compatibility with the clinical setting, (3) the presence of tools that make it easier for the user to engage in therapeutic activities, and (4) the provision of a feasible therapeutic pathway to growth. We then used this set of heuristics to conduct a detailed examination of MyFitnessPal. This line of work could help to set the bar higher for product developers and to inform health care providers about preferred eHealth intervention designs. PMID:26764209

  4. The development of a heuristic-based excel scheduling support system for nurses.

    PubMed

    Cheng, Shih-Tsu; Wung, Shin-Huey; Chang, Polun

    2006-01-01

    The purpose of this study was to develop a nurse-self-made scheduling support system based on the heuristic approach. A Pediatric ICU unit, staffed with 35 nurses, was taken as the case in this study. Nurses' preferred scheduling principles were surveyed. The Excel VBA was used to develop the support system by an informatics nurse. The system was composed of five components: personal scheduling request setting, auto-scheduling, shift modification, report generating and inquiry. The scheduling results were widely accepted by the nurses and the time to plan a monthly schedule was reduced from 4-5 hours to 30 minutes. PMID:17102384

  5. On a heuristic point of view concerning the citation distribution: introducing the Wakeby distribution.

    PubMed

    Katchanov, Yurij L; Markova, Yulia V

    2015-01-01

    The paper proposes a heuristic approach to modeling the cumulative distribution of citations of papers in scientific journals by means of the Wakeby distribution. The Markov process of citation leading to the Wakeby distribution is analyzed using the terminal time formalism. The Wakeby distribution is derived in the paper from the simple and general inhomogeneous Choquet-Deny convolution equation for a non-probability measure. We give statistical evidence that the Wakeby distribution is a reasonable approximation of the empirical citation distributions. AMS Subject Classification: 91D30; 91D99. PMID:25763305

  6. Radial distribution function for hard spheres in fractal dimensions: A heuristic approximation

    NASA Astrophysics Data System (ADS)

    Santos, Andrés; de Haro, Mariano López

    2016-06-01

    Analytic approximations for the radial distribution function, the structure factor, and the equation of state of hard-core fluids in fractal dimension d (1 ≤d ≤3 ) are developed as heuristic interpolations from the knowledge of the exact and Percus-Yevick results for the hard-rod and hard-sphere fluids, respectively. In order to assess their value, such approximate results are compared with those of recent Monte Carlo simulations and numerical solutions of the Percus-Yevick equation for a fractal dimension [M. Heinen et al., Phys. Rev. Lett. 115, 097801 (2015), 10.1103/PhysRevLett.115.097801], a good agreement being observed.

  7. Developing and Validating Personas in e-Commerce: A Heuristic Approach

    NASA Astrophysics Data System (ADS)

    Thoma, Volker; Williams, Bryn

    A multi-method persona development process in a large e-commerce business is described. Personas are fictional representations of customers that describe typical user attributes to facilitate a user-centered approach in interaction design. In the current project persona attributes were derived from various data sources, such as stakeholder interviews, user tests and interviews, data mining, customer surveys, and ethnographic (direct observation, diary studies) research. The heuristic approach of using these data sources conjointly allowed for an early validation of relevant persona dimensions.

  8. Hanke-Raus heuristic rule for variational regularization in Banach spaces

    NASA Astrophysics Data System (ADS)

    Jin, Qinian

    2016-08-01

    We generalize the heuristic parameter choice rule of Hanke-Raus for quadratic regularization to general variational regularization for solving linear as well as nonlinear ill-posed inverse problems in Banach spaces. Under source conditions formulated as variational inequalities, we obtain a posteriori error estimates in term of the Bregman distance. By imposing certain conditions on the random noise, we establish four convergence results; one relies on the source conditions and the other three do not depend on any source conditions. Numerical results are presented to illustrate the performance.

  9. Heuristic reduction of gyro drift in IMU-based personnel tracking systems

    NASA Astrophysics Data System (ADS)

    Borenstein, Johann; Ojeda, Lauro; Kwanmuang, Surat

    2009-05-01

    The paper pertains to the reduction of measurement errors in gyroscopes used for tracking the position of walking persons. Some of these tracking systems commonly use inertial or other means to measure distance traveled, and one or more gyros to measure changes in heading. MEMS-type gyros or IMUs are best suited for this task because of their small size and low weight. However, these gyros have large drift rates and can be sensitive to accelerations. The Heuristic Drift Reduction (HDR) method presented in this paper estimates the drift component and eliminates it, reducing heading errors by almost one order of magnitude.

  10. A Heuristic Approach Based on Clarke-Wright Algorithm for Open Vehicle Routing Problem

    PubMed Central

    2013-01-01

    We propose a heuristic approach based on the Clarke-Wright algorithm (CW) to solve the open version of the well-known capacitated vehicle routing problem in which vehicles are not required to return to the depot after completing service. The proposed CW has been presented in four procedures composed of Clarke-Wright formula modification, open-route construction, two-phase selection, and route postimprovement. Computational results show that the proposed CW is competitive and outperforms classical CW in all directions. Moreover, the best known solution is also obtained in 97% of tested instances (60 out of 62). PMID:24382948

  11. A Modified User-Oriented Heuristic Evaluation of a Mobile Health System for Diabetes Self-management Support

    PubMed Central

    Georgsson, Mattias; Staggers, Nancy; Weir, Charlene

    2016-01-01

    Mobile health platforms offer significant opportunities for improving diabetic self-care, but only if adequate usability exists. Expert evaluations such as heuristic evaluation can provide distinct usability information about systems. The purpose of this study was to complete a usability evaluation of a mobile health system for diabetes patients using a modified heuristic evaluation technique of (1) dual-domain experts (healthcare professionals, usability experts), (2) validated scenarios and user tasks related to patients’ self-care, and (3) in-depth severity factor ratings. Experts identified 129 usability problems with 274 heuristic violations for the system. The categories Consistency and Standards dominated at 24.1% (n = 66), followed by Match Between System and Real World at 22.3% (n = 61). Average severity ratings across system views were 2.8 (of 4), with 9.3% (n = 12) rated as catastrophic and 53.5% (n = 69) as major. The large volume of violations with severe ratings indicated clear priorities for redesign. The modified heuristic approach allowed evaluators to identify unique and important issues, including ones related to self-management and patient safety. This article provides a template for one type of expert evaluation adding to the informaticists’ toolbox when needing to conduct a fast, resource-efficient and user-oriented heuristic evaluation. PMID:26657618

  12. A Modified User-Oriented Heuristic Evaluation of a Mobile Health System for Diabetes Self-management Support.

    PubMed

    Georgsson, Mattias; Staggers, Nancy; Weir, Charlene

    2016-02-01

    Mobile health platforms offer significant opportunities for improving diabetic self-care, but only if adequate usability exists. Expert evaluations such as heuristic evaluation can provide distinct usability information about systems. The purpose of this study was to complete a usability evaluation of a mobile health system for diabetes patients using a modified heuristic evaluation technique of (1) dual-domain experts (healthcare professionals, usability experts), (2) validated scenarios and user tasks related to patients' self-care, and (3) in-depth severity factor ratings. Experts identified 129 usability problems with 274 heuristic violations for the system. The categories Consistency and Standards dominated at 24.1% (n = 66), followed by Match Between System and Real World at 22.3% (n = 61). Average severity ratings across system views were 2.8 (of 4), with 9.3% (n = 12) rated as catastrophic and 53.5% (n = 69) as major. The large volume of violations with severe ratings indicated clear priorities for redesign. The modified heuristic approach allowed evaluators to identify unique and important issues, including ones related to self-management and patient safety. This article provides a template for one type of expert evaluation adding to the informaticists' toolbox when needing to conduct a fast, resource-efficient and user-oriented heuristic evaluation. PMID:26657618

  13. Meta-heuristic algorithms for parallel identical machines scheduling problem with weighted late work criterion and common due date.

    PubMed

    Xu, Zhenzhen; Zou, Yongxing; Kong, Xiangjie

    2015-01-01

    To our knowledge, this paper investigates the first application of meta-heuristic algorithms to tackle the parallel machines scheduling problem with weighted late work criterion and common due date ([Formula: see text]). Late work criterion is one of the performance measures of scheduling problems which considers the length of late parts of particular jobs when evaluating the quality of scheduling. Since this problem is known to be NP-hard, three meta-heuristic algorithms, namely ant colony system, genetic algorithm, and simulated annealing are designed and implemented, respectively. We also propose a novel algorithm named LDF (largest density first) which is improved from LPT (longest processing time first). The computational experiments compared these meta-heuristic algorithms with LDF, LPT and LS (list scheduling), and the experimental results show that SA performs the best in most cases. However, LDF is better than SA in some conditions, moreover, the running time of LDF is much shorter than SA. PMID:26702371

  14. Parallel machine scheduling problem with ready times, due times and sequence-dependent setup times using meta-heuristic algorithms

    NASA Astrophysics Data System (ADS)

    Joo, Cheol Min; Kim, Byung Soo

    2012-09-01

    This article considers a parallel machine scheduling problem with ready times, due times and sequence-dependent setup times. The objective of this problem is to determine the allocation policy of jobs and the scheduling policy of machines to minimize the weighted sum of setup times, delay times and tardy times. A mathematical model for optimal solution is derived. An in-depth analysis of the model shows that it is very complicated and difficult to obtain optimal solutions as the problem size becomes large. Therefore, two meta-heuristics, genetic algorithm (GA) and a new population-based evolutionary meta-heuristic called self-evolution algorithm (SEA), are proposed. The performances of the meta-heuristic algorithms are evaluated through comparison with optimal solutions using several randomly generated examples.

  15. Non-uniform cosine modulated filter banks using meta-heuristic algorithms in CSD space.

    PubMed

    Kalathil, Shaeen; Elias, Elizabeth

    2015-11-01

    This paper presents an efficient design of non-uniform cosine modulated filter banks (CMFB) using canonic signed digit (CSD) coefficients. CMFB has got an easy and efficient design approach. Non-uniform decomposition can be easily obtained by merging the appropriate filters of a uniform filter bank. Only the prototype filter needs to be designed and optimized. In this paper, the prototype filter is designed using window method, weighted Chebyshev approximation and weighted constrained least square approximation. The coefficients are quantized into CSD, using a look-up-table. The finite precision CSD rounding, deteriorates the filter bank performances. The performances of the filter bank are improved using suitably modified meta-heuristic algorithms. The different meta-heuristic algorithms which are modified and used in this paper are Artificial Bee Colony algorithm, Gravitational Search algorithm, Harmony Search algorithm and Genetic algorithm and they result in filter banks with less implementation complexity, power consumption and area requirements when compared with those of the conventional continuous coefficient non-uniform CMFB. PMID:26644921

  16. Minimizing impacts of land use change on ecosystem services using multi-criteria heuristic analysis.

    PubMed

    Keller, Arturo A; Fournier, Eric; Fox, Jessica

    2015-06-01

    Development of natural landscapes to support human activities impacts the capacity of the landscape to provide ecosystem services. Typically, several ecosystem services are impacted at a single development site and various footprint scenarios are possible, thus a multi-criteria analysis is needed. Restoration potential should also be considered for the area surrounding the permanent impact site. The primary objective of this research was to develop a heuristic approach to analyze multiple criteria (e.g. impacts to various ecosystem services) in a spatial configuration with many potential development sites. The approach was to: (1) quantify the magnitude of terrestrial ecosystem service (biodiversity, carbon sequestration, nutrient and sediment retention, and pollination) impacts associated with a suite of land use change scenarios using the InVEST model; (2) normalize results across categories of ecosystem services to allow cross-service comparison; (3) apply the multi-criteria heuristic algorithm to select sites with the least impact to ecosystem services, including a spatial criterion (separation between sites). As a case study, the multi-criteria impact minimization algorithm was applied to InVEST output to select 25 potential development sites out of 204 possible locations (selected by other criteria) within a 24,000 ha property. This study advanced a generally applicable spatial multi-criteria approach for 1) considering many land use footprint scenarios, 2) balancing impact decisions across a suite of ecosystem services, and 3) determining the restoration potential of ecosystem services after impacts. PMID:25794964

  17. A heuristic two-dimensional presentation of microsatellite-based data applied to dogs and wolves

    PubMed Central

    Veit-Kensch, Claudia E; Medugorac, Ivica; Jedrzejewski, Włodzimierz; Bunevich, Aleksei N; Foerster, Martin

    2007-01-01

    Methods based on genetic distance matrices usually lose information during the process of tree-building by converting a multi-dimensional matrix into a phylogenetic tree. We applied a heuristic method of two-dimensional presentation to achieve a better resolution of the relationship between breeds and individuals investigated. Four hundred and nine individuals from nine German dog breed populations and one free-living wolf population were analysed with a marker set of 23 microsatellites. The result of the two-dimensional presentation was partly comparable with and complemented a model-based analysis that uses genotype patterns. The assignment test and the neighbour-joining tree based on allele sharing estimate allocated 99% and 97% of the individuals according to their breed, respectively. The application of the two-dimensional presentation to distances on the basis of the proportion of shared alleles resulted in comparable and further complementary insight into inferred population structure by multilocus genotype data. We expect that the inference of population structure in domesticated species with complex breeding histories can be strongly supported by the two-dimensional presentation based on the described heuristic method. PMID:17612483

  18. The compatibility heuristic in non-categorical hypothetical reasoning: inferences between conditionals and disjunctions.

    PubMed

    Espino, Orlando; Byrne, Ruth M J

    2013-11-01

    A new theory explains how people make hypothetical inferences from a premise consistent with several alternatives to a conclusion consistent with several alternatives. The key proposal is that people rely on a heuristic that identifies compatible possibilities. It is tested in 7 experiments that examine inferences between conditionals and disjunctions. Participants accepted inferences between conditionals and inclusive disjunctions when a compatible possibility was immediately available, in their binary judgments that a conclusion followed or not (Experiment 1a) and ternary judgments that included it was not possible to know (Experiment 1b). The compatibility effect was amplified when compatible possibilities were more readily available, e.g., for 'A only if B' conditionals (Experiment 2). It was eliminated when compatible possibilities were not available, e.g., for 'if and only if A B' bi-conditionals and exclusive disjunctions (Experiment 3). The compatibility heuristic occurs even for inferences based on implicit negation e.g., 'A or B, therefore if C D' (Experiment 4), and between universals 'All A's are B's' and disjunctions (Experiment 5a) and universals and conditionals (Experiment 5b). The implications of the results for alternative theories of the cognitive processes underlying hypothetical deductions are discussed. PMID:23968595

  19. Robot navigation in unknown terrains: Introductory survey of non-heuristic algorithms

    SciTech Connect

    Rao, N.S.V.; Kareti, S.; Shi, Weimin; Iyengar, S.S.

    1993-07-01

    A formal framework for navigating a robot in a geometric terrain by an unknown set of obstacles is considered. Here the terrain model is not a priori known, but the robot is equipped with a sensor system (vision or touch) employed for the purpose of navigation. The focus is restricted to the non-heuristic algorithms which can be theoretically shown to be correct within a given framework of models for the robot, terrain and sensor system. These formulations, although abstract and simplified compared to real-life scenarios, provide foundations for practical systems by highlighting the underlying critical issues. First, the authors consider the algorithms that are shown to navigate correctly without much consideration given to the performance parameters such as distance traversed, etc. Second, they consider non-heuristic algorithms that guarantee bounds on the distance traversed or the ratio of the distance traversed to the shortest path length (computed if the terrain model is known). Then they consider the navigation of robots with very limited computational capabilities such as finite automata, etc.

  20. Heuristics for multiobjective optimization of two-sided assembly line systems.

    PubMed

    Jawahar, N; Ponnambalam, S G; Sivakumar, K; Thangadurai, V

    2014-01-01

    Products such as cars, trucks, and heavy machinery are assembled by two-sided assembly line. Assembly line balancing has significant impacts on the performance and productivity of flow line manufacturing systems and is an active research area for several decades. This paper addresses the line balancing problem of a two-sided assembly line in which the tasks are to be assigned at L side or R side or any one side (addressed as E). Two objectives, minimum number of workstations and minimum unbalance time among workstations, have been considered for balancing the assembly line. There are two approaches to solve multiobjective optimization problem: first approach combines all the objectives into a single composite function or moves all but one objective to the constraint set; second approach determines the Pareto optimal solution set. This paper proposes two heuristics to evolve optimal Pareto front for the TALBP under consideration: Enumerative Heuristic Algorithm (EHA) to handle problems of small and medium size and Simulated Annealing Algorithm (SAA) for large-sized problems. The proposed approaches are illustrated with example problems and their performances are compared with a set of test problems. PMID:24790568

  1. Maximizing the nurses' preferences in nurse scheduling problem: mathematical modeling and a meta-heuristic algorithm

    NASA Astrophysics Data System (ADS)

    Jafari, Hamed; Salmasi, Nasser

    2015-04-01

    The nurse scheduling problem (NSP) has received a great amount of attention in recent years. In the NSP, the goal is to assign shifts to the nurses in order to satisfy the hospital's demand during the planning horizon by considering different objective functions. In this research, we focus on maximizing the nurses' preferences for working shifts and weekends off by considering several important factors such as hospital's policies, labor laws, governmental regulations, and the status of nurses at the end of the previous planning horizon in one of the largest hospitals in Iran i.e., Milad Hospital. Due to the shortage of available nurses, at first, the minimum total number of required nurses is determined. Then, a mathematical programming model is proposed to solve the problem optimally. Since the proposed research problem is NP-hard, a meta-heuristic algorithm based on simulated annealing (SA) is applied to heuristically solve the problem in a reasonable time. An initial feasible solution generator and several novel neighborhood structures are applied to enhance performance of the SA algorithm. Inspired from our observations in Milad hospital, random test problems are generated to evaluate the performance of the SA algorithm. The results of computational experiments indicate that the applied SA algorithm provides solutions with average percentage gap of 5.49 % compared to the upper bounds obtained from the mathematical model. Moreover, the applied SA algorithm provides significantly better solutions in a reasonable time than the schedules provided by the head nurses.

  2. Heuristics can produce surprisingly rational probability estimates: Comment on Costello and Watts (2014).

    PubMed

    Nilsson, Håkan; Juslin, Peter; Winman, Anders

    2016-01-01

    Costello and Watts (2014) present a model assuming that people's knowledge of probabilities adheres to probability theory, but that their probability judgments are perturbed by a random noise in the retrieval from memory. Predictions for the relationships between probability judgments for constituent events and their disjunctions and conjunctions, as well as for sums of such judgments were derived from probability theory. Costello and Watts (2014) report behavioral data showing that subjective probability judgments accord with these predictions. Based on the finding that subjective probability judgments follow probability theory, Costello and Watts (2014) conclude that the results imply that people's probability judgments embody the rules of probability theory and thereby refute theories of heuristic processing. Here, we demonstrate the invalidity of this conclusion by showing that all of the tested predictions follow straightforwardly from an account assuming heuristic probability integration (Nilsson, Winman, Juslin, & Hansson, 2009). We end with a discussion of a number of previous findings that harmonize very poorly with the predictions by the model suggested by Costello and Watts (2014). PMID:26709414

  3. Heuristic ternary error-correcting output codes via weight optimization and layered clustering-based approach.

    PubMed

    Zhang, Xiao-Lei

    2015-02-01

    One important classifier ensemble for multiclass classification problems is error-correcting output codes (ECOCs). It bridges multiclass problems and binary-class classifiers by decomposing multiclass problems to a serial binary-class problems. In this paper, we present a heuristic ternary code, named weight optimization and layered clustering-based ECOC (WOLC-ECOC). It starts with an arbitrary valid ECOC and iterates the following two steps until the training risk converges. The first step, named layered clustering-based ECOC (LC-ECOC), constructs multiple strong classifiers on the most confusing binary-class problem. The second step adds the new classifiers to ECOC by a novel optimized weighted (OW) decoding algorithm, where the optimization problem of the decoding is solved by the cutting plane algorithm. Technically, LC-ECOC makes the heuristic training process not blocked by some difficult binary-class problem. OW decoding guarantees the nonincrease of the training risk for ensuring a small code length. Results on 14 UCI datasets and a music genre classification problem demonstrate the effectiveness of WOLC-ECOC. PMID:25486660

  4. Performance evaluation of the GA/SA hybrid heuristic optimum filter for optical pattern recognition

    NASA Astrophysics Data System (ADS)

    Yeun, Jin S.; Kim, Nam; Pan, Jae Kyung; Kim, R. S.; Um, J. U.; Kim, Sang H.

    1997-04-01

    In this paper, we newly apply a genetic and simulated annealing hybrid heuristic to encode optimal filter for optical pattern recognition. Simulated annealing as a stochastic computational technique allows for finding near globally-minimum-cost solutions with cooling schedule. Using the advantages of a parallelizable genetic algorithm (GA) and a simulated annealing algorithm (SA), the optimum filters are designed and implemented. The filter having 128 multiplied by 128 pixel size consists of the stepped phase that causes the discrete phase delay. The structure of this can be divided into rectangular cells such that each cell imparts a discrete phase delay of 0 approximately equals 2 pi[rad] to the incident wave front. Eight-phase stepped filters that we designed are compared with phase only matched filter and cosine-binary phase only filter. It is deeply focused on investigating the performance of the optimum filter in terms of recognition characteristics on the translation, scale and rotation variations of the image, and discrimination properties against similar images. By GA/SA hybrid heuristic, the optimum filter is realized for high efficiency optical reconstruction in spite of decreasing iteration number needed to encode it by respective algorithms.

  5. Efficient GRASP based heuristics for the capacitated continuous location-allocation problem

    NASA Astrophysics Data System (ADS)

    Luis, Martino; Ramli, Mohammad Fadzli; Saputra, Ruswiati Surya

    2015-05-01

    This paper explores the np-hard capacitated continuous location-allocation problem, where the number of facilities to be located is specified and each of which has a constant capacity. Efficient greedy randomised adaptive search procedure (GRASP) based heuristics are proposed to tackle the problem. A scheme that applies the furthest distance rule (FDR) and self-adjusted threshold parameters to generate initial facility locations that are situated sparsely within GRASP framework is also put forward. The construction of the restricted candidate list (RCL) within GRASP is also guided by applying a concept of restricted regions that prevents new facility locations to be sited too close to the previous selected facility locations. The performance of the proposed GRASP heuristics is evaluated by conducting experiments using data sets taken from the literature typically used for the uncapacitated continuous location-allocation problem. The preliminary computational experiments show that the proposed methods provide encouraging solutions when compared to recently published papers. Some future research avenues on the subject are also briefly highlighted.

  6. Social heuristics and social roles: Intuition favors altruism for women but not for men.

    PubMed

    Rand, David G; Brescoll, Victoria L; Everett, Jim A C; Capraro, Valerio; Barcelo, Hélène

    2016-04-01

    Are humans intuitively altruistic, or does altruism require self-control? A theory of social heuristics, whereby intuitive responses favor typically successful behaviors, suggests that the answer may depend on who you are. In particular, evidence suggests that women are expected to behave altruistically, and are punished for failing to be altruistic, to a much greater extent than men. Thus, women (but not men) may internalize altruism as their intuitive response. Indeed, a meta-analysis of 13 new experiments and 9 experiments from other groups found that promoting intuition relative to deliberation increased giving in a Dictator Game among women, but not among men (Study 1, N = 4,366). Furthermore, this effect was shown to be moderated by explicit sex role identification (Study 2, N = 1,831): the more women described themselves using traditionally masculine attributes (e.g., dominance, independence) relative to traditionally feminine attributes (e.g., warmth, tenderness), the more deliberation reduced their altruism. Our findings shed light on the connection between gender and altruism, and highlight the importance of social heuristics in human prosociality. PMID:26913619

  7. The scarcity heuristic impacts reward processing within the medial-frontal cortex.

    PubMed

    Williams, Chad C; Saffer, Boaz Y; McCulloch, Robert B; Krigolson, Olave E

    2016-05-01

    Objects that are rare are often perceived to be inherently more valuable than objects that are abundant - a bias brought about in part by the scarcity heuristic. In the present study, we sought to test whether perception of rarity impacted reward evaluation within the human medial-frontal cortex. Here, participants played a gambling game in which they flipped rare and abundant 'cards' on a computer screen to win financial rewards while electroencephalographic data were recorded. Unbeknownst to participants, reward outcome and frequency was random and equivalent for both rare and abundant cards; thus, only a perception of scarcity was true. Analysis of the electroencephalographic data indicated that the P300 component of the event-related brain potential differed in amplitude for wins and losses following the selection of rare cards, but not following the selection of abundant cards. Importantly, then, we found that the perception of card rarity impacted reward processing even though reward feedback was independent of and subsequent to card selection. Our data indicate a top-down influence of the scarcity heuristic on reward evaluation, and specifically the processing of reward magnitude, within the human medial-frontal cortex. PMID:27031875

  8. Visualization for Hyper-Heuristics. Front-End Graphical User Interface

    SciTech Connect

    Kroenung, Lauren

    2015-03-01

    Modern society is faced with ever more complex problems, many of which can be formulated as generate-and-test optimization problems. General-purpose optimization algorithms are not well suited for real-world scenarios where many instances of the same problem class need to be repeatedly and efficiently solved because they are not targeted to a particular scenario. Hyper-heuristics automate the design of algorithms to create a custom algorithm for a particular scenario. While such automated design has great advantages, it can often be difficult to understand exactly how a design was derived and why it should be trusted. This project aims to address these issues of usability by creating an easy-to-use graphical user interface (GUI) for hyper-heuristics to support practitioners, as well as scientific visualization of the produced automated designs. My contributions to this project are exhibited in the user-facing portion of the developed system and the detailed scientific visualizations created from back-end data.

  9. Parsimony score of phylogenetic networks: hardness results and a linear-time heuristic.

    PubMed

    Jin, Guohua; Nakhleh, Luay; Snir, Sagi; Tuller, Tamir

    2009-01-01

    Phylogenies-the evolutionary histories of groups of organisms-play a major role in representing the interrelationships among biological entities. Many methods for reconstructing and studying such phylogenies have been proposed, almost all of which assume that the underlying history of a given set of species can be represented by a binary tree. Although many biological processes can be effectively modeled and summarized in this fashion, others cannot: recombination, hybrid speciation, and horizontal gene transfer result in networks of relationships rather than trees of relationships. In previous works, we formulated a maximum parsimony (MP) criterion for reconstructing and evaluating phylogenetic networks, and demonstrated its quality on biological as well as synthetic data sets. In this paper, we provide further theoretical results as well as a very fast heuristic algorithm for the MP criterion of phylogenetic networks. In particular, we provide a novel combinatorial definition of phylogenetic networks in terms of "forbidden cycles," and provide detailed hardness and hardness of approximation proofs for the "small" MP problem. We demonstrate the performance of our heuristic in terms of time and accuracy on both biological and synthetic data sets. Finally, we explain the difference between our model and a similar one formulated by Nguyen et al., and describe the implications of this difference on the hardness and approximation results. PMID:19644176

  10. Monte Carlo Method with Heuristic Adjustment for Irregularly Shaped Food Product Volume Measurement

    PubMed Central

    Siswantoro, Joko; Idrus, Bahari

    2014-01-01

    Volume measurement plays an important role in the production and processing of food products. Various methods have been proposed to measure the volume of food products with irregular shapes based on 3D reconstruction. However, 3D reconstruction comes with a high-priced computational cost. Furthermore, some of the volume measurement methods based on 3D reconstruction have a low accuracy. Another method for measuring volume of objects uses Monte Carlo method. Monte Carlo method performs volume measurements using random points. Monte Carlo method only requires information regarding whether random points fall inside or outside an object and does not require a 3D reconstruction. This paper proposes volume measurement using a computer vision system for irregularly shaped food products without 3D reconstruction based on Monte Carlo method with heuristic adjustment. Five images of food product were captured using five cameras and processed to produce binary images. Monte Carlo integration with heuristic adjustment was performed to measure the volume based on the information extracted from binary images. The experimental results show that the proposed method provided high accuracy and precision compared to the water displacement method. In addition, the proposed method is more accurate and faster than the space carving method. PMID:24892069

  11. Parallel iterative solution of sparse linear systems using orderings from graph coloring heuristics

    SciTech Connect

    Jones, M.T.; Plassmann, P.E.

    1990-12-01

    The efficiency of a parallel implementation of the conjugate gradient method preconditioned by an incomplete Cholesky factorization can vary dramatically depending on the column ordering chosen. One method to minimize the number of major parallel steps is to choose an ordering based on a coloring of the symmetric graph representing the nonzero adjacency structure of the matrix. In this paper, we compare the performance of the preconditioned conjugate gradient method using these coloring orderings with a number of standard orderings on matrices arising from applications in structural engineering. Because optimal colorings for these systems may not be a priori known: we employ several graph coloring heuristics to obtain consistent colorings. Based on lower bounds obtained from the local structure of these systems, we find that the colorings determined by these heuristics are nearly optimal. For these problems, we find that the increase in parallelism afforded by the coloring-based orderings more than offsets any increase in the number of iterations required for the convergence of the conjugate gradient algorithm.

  12. Job-shop scheduling with a combination of evolutionary and heuristic methods

    NASA Astrophysics Data System (ADS)

    Patkai, Bela; Torvinen, Seppo

    1999-08-01

    Since almost all of the scheduling problems are NP-hard-- cannot be solved in polynomial time--those companies that need a realistic scheduling system face serious limitations of available methods for finding an optimal schedule, especially if the given environment requires adaptation to dynamic variations. Exact methods do find an optimal schedule, but the size of the problem they can solve is very limited, excluding this way the required scalability. The solution presented in this paper is a simple, multi-pass heuristic method, which aims to avoid the limitations of other well-known formulations. Even though the dispatching rules are fast and provide near-optimal solutions in most cases, they are severely limited in efficiency--especially in case the schedule builder satisfies a significant number of constraints. That is the main motivation for adding a simplified genetic algorithm to the dispatching rules, which--due to its stochastic nature--belongs to heuristic, too. The scheduling problem is of a middle size Finnish factory, throughout the investigations their up-to-date manufacturing data has been used for the sake of realistic calculations.

  13. Heuristics for Multiobjective Optimization of Two-Sided Assembly Line Systems

    PubMed Central

    Jawahar, N.; Ponnambalam, S. G.; Sivakumar, K.; Thangadurai, V.

    2014-01-01

    Products such as cars, trucks, and heavy machinery are assembled by two-sided assembly line. Assembly line balancing has significant impacts on the performance and productivity of flow line manufacturing systems and is an active research area for several decades. This paper addresses the line balancing problem of a two-sided assembly line in which the tasks are to be assigned at L side or R side or any one side (addressed as E). Two objectives, minimum number of workstations and minimum unbalance time among workstations, have been considered for balancing the assembly line. There are two approaches to solve multiobjective optimization problem: first approach combines all the objectives into a single composite function or moves all but one objective to the constraint set; second approach determines the Pareto optimal solution set. This paper proposes two heuristics to evolve optimal Pareto front for the TALBP under consideration: Enumerative Heuristic Algorithm (EHA) to handle problems of small and medium size and Simulated Annealing Algorithm (SAA) for large-sized problems. The proposed approaches are illustrated with example problems and their performances are compared with a set of test problems. PMID:24790568

  14. How Smart Do You Need to Be to Get It Wrong? The Role of Cognitive Capacity in the Development of Heuristic-Based Judgment

    ERIC Educational Resources Information Center

    Morsanyi, Kinga; Handley, Simon J.

    2008-01-01

    We examined the relationship between cognitive capacity and heuristic responding on four types of reasoning and decision-making tasks. A total of 84 children, between 5 years 2 months and 11 years 7 months of age, participated in the study. There was a marked increase in heuristic responding with age that was related to increases in cognitive…

  15. Effects of Cognitive Strategy Interventions and Cognitive Moderators on Word Problem Solving in Children at Risk for Problem Solving Difficulties

    ERIC Educational Resources Information Center

    Swanson, H. Lee; Lussier, Cathy; Orosco, Michael

    2013-01-01

    This study investigated the role of strategy instruction and cognitive abilities on word problem solving accuracy in children with math difficulties (MD). Elementary school children (N = 120) with and without MD were randomly assigned to 1 of 4 conditions: general-heuristic (e.g., underline question sentence), visual-schematic presentation…

  16. Methodological Drawbacks of Current Educational Software and Suggestions for Radical Improvement Based on Algo-Heuristic Theory.

    ERIC Educational Resources Information Center

    Landa, Lev N.

    1998-01-01

    After reviewing 50 educational software titles produced by 21 companies to assess how thinking and thinking skills were developed, the author found most had similar methodological drawbacks. Describes the algo-heuristic methodological position and outlines drawbacks of current software. (PEN)

  17. Teaching Problem Solving; the Effect of Algorithmic and Heuristic Problem Solving Training in Relation to Task Complexity and Relevant Aptitudes.

    ERIC Educational Resources Information Center

    de Leeuw, L.

    Sixty-four fifth and sixth-grade pupils were taught number series extrapolation by either an algorithm, fully prescribed problem-solving method or a heuristic, less prescribed method. The trained problems were within categories of two degrees of complexity. There were 16 subjects in each cell of the 2 by 2 design used. Aptitude Treatment…

  18. What Is behind the Priority Heuristic? A Mathematical Analysis and Comment on Brandstatter, Gigerenzer, and Hertwig (2006)

    ERIC Educational Resources Information Center

    Rieger, Marc Oliver; Wang, Mei

    2008-01-01

    Comments on the article by E. Brandstatter, G. Gigerenzer, and R. Hertwig (2006). The authors discuss the priority heuristic, a recent model for decisions under risk. They reanalyze the experimental validity of this approach and discuss how these results compare with cumulative prospect theory, the currently most established model in behavioral…

  19. The Tip-of-the-Tongue Heuristic: How Tip-of-the-Tongue States Confer Perceptibility on Inaccessible Words

    ERIC Educational Resources Information Center

    Cleary, Anne M.; Claxton, Alexander B.

    2015-01-01

    This study shows that the presence of a tip-of-the-tongue (TOT) state--the sense that a word is in memory when its retrieval fails--is used as a heuristic for inferring that an inaccessible word has characteristics that are consistent with greater word perceptibility. When reporting a TOT state, people judged an unretrieved word as more likely to…

  20. Answer First: Applying the Heuristic-Analytic Theory of Reasoning to Examine Student Intuitive Thinking in the Context of Physics

    ERIC Educational Resources Information Center

    Kryjevskaia, Mila; Stetzer, MacKenzie R.; Grosz, Nathaniel

    2014-01-01

    We have applied the heuristic-analytic theory of reasoning to interpret inconsistencies in student reasoning approaches to physics problems. This study was motivated by an emerging body of evidence that suggests that student conceptual and reasoning competence demonstrated on one task often fails to be exhibited on another. Indeed, even after…

  1. Programming strategies in the game of push-over

    SciTech Connect

    Le-ngoc, T.; Vroomen, L.C.

    1982-08-01

    Some heuristic techniques used in programming games, and particularly techniques applied to the game of push-over, are discussed. Push-over is a simple, two-person, strictly competitive game. By a strictly competitive (or zero-sum) game is meant one in which one player always wins and his opponent always loses, making cooperation never worthwhile. In push-over, one can develop what is known as a strategic-value function, which serves as a heuristic to optimise a player's response to a given situation. The choice of the strategic-value function, the characteristics of three different strategies and the details of the game's data and program structures are examined. 4 references.

  2. A Heuristic Model of Consciousness with Applications to the Development of Science and Society

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.

    2010-01-01

    A working model of consciousness is fundamental to understanding of the interactions of the observer in science. This paper examines contemporary understanding of consciousness. A heuristic model of consciousness is suggested that is consistent with psycophysics measurements of bandwidth of consciousness relative to unconscious perception. While the self reference nature of consciousness confers a survival benefit by assuring the all points of view regarding a problem are experienced in sufficiently large population, conscious bandwidth is constrained by design to avoid chaotic behavior. The multiple hypotheses provided by conscious reflection enable the rapid progression of science and technology. The questions of free will and the problem of attention are discussed in relation to the model. Finally the combination of rapid technology growth with the assurance of many unpredictable points of view is considered in respect to contemporary constraints to the development of society.

  3. Heuristic method for searches on large data-sets organised using network models

    NASA Astrophysics Data System (ADS)

    Ruiz-Fernández, D.; Quintana-Pacheco, Y.

    2016-05-01

    Searches on large data-sets have become an important issue in recent years. An alternative, which has achieved good results, is the use of methods relying on data mining techniques, such as cluster-based retrieval. This paper proposes a heuristic search that is based on an organisational model that reflects similarity relationships among data elements. The search is guided by using quality estimators of model nodes, which are obtained by the progressive evaluation of the given target function for the elements associated with each node. The results of the experiments confirm the effectiveness of the proposed algorithm. High-quality solutions are obtained evaluating a relatively small percentage of elements in the data-sets.

  4. Selection of actuator locations for static shape control of large space structures by heuristic integer programing

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Adelman, H. M.

    1984-01-01

    Orbiting spacecraft such as large space antennas have to maintain a highly accurate space to operate satisfactorily. Such structures require active and passive controls to mantain an accurate shape under a variety of disturbances. Methods for the optimum placement of control actuators for correcting static deformations are described. In particular, attention is focused on the case were control locations have to be selected from a large set of available sites, so that integer programing methods are called for. The effectiveness of three heuristic techniques for obtaining a near-optimal site selection is compared. In addition, efficient reanalysis techniques for the rapid assessment of control effectiveness are presented. Two examples are used to demonstrate the methods: a simple beam structure and a 55m space-truss-parabolic antenna.

  5. Selection of actuator locations for static shape control of large space structures by heuristic integer programing

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Adelman, H. M.

    1985-01-01

    Orbiting spacecraft such as large space antennas have to maintain a highly accurate shape to operate satisfactorily. Such structures require active and passive controls to maintain an accurate shape under a variety of disturbances. Methods for the optimum placement of control actuators for correcting static deformations are described. In particular, attention is focused on the case were control locations have to be selected from a large set of available sites, so that integer programing methods are called for. The effectiveness of three heuristic techniques for obtaining a near-optimal site selection is compared. In addition, efficient reanalysis techniques for the rapid assessment of control effectiveness are presented. Two examples are used to demonstrate the methods: a simple beam structure and a 55m space-truss-parabolic antenna.

  6. Radial distribution function for hard spheres in fractal dimensions: A heuristic approximation.

    PubMed

    Santos, Andrés; de Haro, Mariano López

    2016-06-01

    Analytic approximations for the radial distribution function, the structure factor, and the equation of state of hard-core fluids in fractal dimension d (1≤d≤3) are developed as heuristic interpolations from the knowledge of the exact and Percus-Yevick results for the hard-rod and hard-sphere fluids, respectively. In order to assess their value, such approximate results are compared with those of recent Monte Carlo simulations and numerical solutions of the Percus-Yevick equation for a fractal dimension [M. Heinen et al., Phys. Rev. Lett. 115, 097801 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.097801], a good agreement being observed. PMID:27415227

  7. Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers

    NASA Astrophysics Data System (ADS)

    Quiroz, Felipe García; Chilkoti, Ashutosh

    2015-11-01

    Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesizing intrinsically disordered, repeat proteins to test motifs that we hypothesized would encode phase behaviour, we show that the proteins can be designed to exhibit tunable lower or upper critical solution temperature (LCST and UCST, respectively) transitions in physiological solutions. We also show that mutation of key residues at the repeat level abolishes phase behaviour or encodes an orthogonal transition. Furthermore, we provide heuristics to identify, at the proteome level, proteins that might exhibit phase behaviour and to design novel protein polymers consisting of biologically active peptide repeats that exhibit LCST or UCST transitions. These findings set the foundation for the prediction and encoding of phase behaviour at the sequence level.

  8. The Dynamical Recollection of Interconnected Neural Networks Using Meta-heuristics

    NASA Astrophysics Data System (ADS)

    Kuremoto, Takashi; Watanabe, Shun; Kobayashi, Kunikazu; Feng, Laing-Bing; Obayashi, Masanao

    The interconnected recurrent neural networks are well-known with their abilities of associative memory of characteristic patterns. For example, the traditional Hopfield network (HN) can recall stored pattern stably, meanwhile, Aihara's chaotic neural network (CNN) is able to realize dynamical recollection of a sequence of patterns. In this paper, we propose to use meta-heuristic (MH) methods such as the particle swarm optimization (PSO) and the genetic algorithm (GA) to improve traditional associative memory systems. Using PSO or GA, for CNN, optimal parameters are found to accelerate the recollection process and raise the rate of successful recollection, and for HN, optimized bias current is calculated to improve the network with dynamical association of a series of patterns. Simulation results of binary pattern association showed effectiveness of the proposed methods.

  9. Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers

    PubMed Central

    Quiroz, Felipe García; Chilkoti, Ashutosh

    2015-01-01

    Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesizing intrinsically disordered, repeat proteins to test motifs that we hypothesized would encode phase behaviour, we show that the proteins can be designed to exhibit tunable lower or upper critical solution temperature (LCST and UCST, respectively) transitions in physiological solutions. We also show that mutation of key residues at the repeat level abolishes phase behaviour or encodes an orthogonal transition. Furthermore, we provide heuristics to identify, at the proteome level, proteins that might exhibit phase behaviour and to design novel protein polymers consisting of biologically active peptide repeats that exhibit LCST or UCST transitions. These findings set the foundation for the prediction and encoding of phase behaviour at the sequence level. PMID:26390327

  10. Identifying and Addressing Stakeholder Interests in Design Science Research: An Analysis Using Critical Systems Heuristics

    NASA Astrophysics Data System (ADS)

    Venable, John R.

    This paper utilises the Critical Systems Heuristics (CSH) framework developed by Werner Ulrich to critically consider the stakeholders and design goals that should be considered as relevant by researchers conducing Design Science Research (DSR). CSH provides a philosophically and theoretically grounded framework and means for critical consideration of the choices of stakeholders considered to be relevant to any system under design consideration. The paper recommends that legitimately undertaken DSR should include witnesses to represent the interests of the future consumers of the outcomes of DSR, i.e., the future clients, decision makers, professionals, and other non-included stakeholders in the future use of the solution technologies to be invented in DSR. The paper further discusses options for how witnesses might be included, who should be witnessed for and obstacles to implementing the recommendations.

  11. An explanatory heuristic gives rise to the belief that words are well suited for their referents.

    PubMed

    Sutherland, Shelbie L; Cimpian, Andrei

    2015-10-01

    The mappings between the words of a language and their meanings are arbitrary. There is, for example, nothing inherently dog-like about the word dog. And yet, building on prior evidence (e.g., Brook, 1970; Piaget, 1967), the six studies reported here (N=1062) suggest that both children and (at least to some extent) adults see a special "fit" between objects and their names, as if names were particularly suitable or appropriate for the objects they denote. These studies also provide evidence for a novel proposal concerning the source of these nominal fit beliefs. Specifically, beliefs about nominal fit may be a byproduct of the heuristic processes that people use to make sense of the world more generally (Cimpian & Salomon, 2014a). In sum, the present studies provide new insights into how people conceive of language and demonstrate that these conceptions are rooted in the processes that underlie broader explanatory reasoning. PMID:26226428

  12. On Vortex Genesis. An Heuristic Model of Convection-Advection Linkages

    NASA Astrophysics Data System (ADS)

    Bouali, S.

    2003-04-01

    We connect to a model of convection roll an appropriate feedback loop (i.e., the advection retroaction) which unfolds a wide range of vorticity behavior. The 3D numerical computations display the conservative aerologic flows of waterspouts and tropical cyclones. Moreover, several simulations exhibit the singular topology of the structure of cyclones eventually trapped in period-2 orbit. On the other hand, additional advection linkages provide our dynamical system with an explicative proof of the tornadogenesis. These amendements modify the model. The airflows are now dissipatives and we investigate the kinematics of these short life span phenomena. The extended model leads the trajectories of air pockets to one or more vortices. The downbursts and microbursts described in the Fujita classification are also simulated. Our heuristic dynamical system lays the foundation of an unified modelisation of vortices. Theory and Direct Numerical Simulation of the vortex genesis are associated in a new perspective.

  13. Lagrangian heuristic method for the wireless sensor network design problem in railway structural health monitoring

    NASA Astrophysics Data System (ADS)

    Hada, Akio; Soga, Kenichi; Liu, Ruoshui; Wassell, Ian J.

    2012-04-01

    In this paper, we study a design method for minimizing the total cost of a wireless sensor network (WSN) used for health monitoring of railway structures. First, we present the problem, that is to simultaneously determine the number of relays and their deployment locations, the transmission power level for each sensor and relay, and the routes for transferring sensor data to a gateway using multi-hop wireless communication. Second, we formulate this task as a mathematical programming problem, and to solve this problem, we propose a near optimal algorithm based on the Lagrangian heuristic method. Finally, we verify the effectiveness of our algorithm through computational experiments carried out using data acquired from a real WSN used for railway structural health monitoring.

  14. An efficient heuristic method for dynamic portfolio selection problem under transaction costs and uncertain conditions

    NASA Astrophysics Data System (ADS)

    Najafi, Amir Abbas; Pourahmadi, Zahra

    2016-04-01

    Selecting the optimal combination of assets in a portfolio is one of the most important decisions in investment management. As investment is a long term concept, looking into a portfolio optimization problem just in a single period may cause loss of some opportunities that could be exploited in a long term view. Hence, it is tried to extend the problem from single to multi-period model. We include trading costs and uncertain conditions to this model which made it more realistic and complex. Hence, we propose an efficient heuristic method to tackle this problem. The efficiency of the method is examined and compared with the results of the rolling single-period optimization and the buy and hold method which shows the superiority of the proposed method.

  15. Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers.

    PubMed

    Quiroz, Felipe García; Chilkoti, Ashutosh

    2015-11-01

    Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesizing intrinsically disordered, repeat proteins to test motifs that we hypothesized would encode phase behaviour, we show that the proteins can be designed to exhibit tunable lower or upper critical solution temperature (LCST and UCST, respectively) transitions in physiological solutions. We also show that mutation of key residues at the repeat level abolishes phase behaviour or encodes an orthogonal transition. Furthermore, we provide heuristics to identify, at the proteome level, proteins that might exhibit phase behaviour and to design novel protein polymers consisting of biologically active peptide repeats that exhibit LCST or UCST transitions. These findings set the foundation for the prediction and encoding of phase behaviour at the sequence level. PMID:26390327

  16. Stellar occultations by turbulent planetary atmospheres. I - A heuristic scattering model. II - The Beta Scorpii events

    NASA Technical Reports Server (NTRS)

    Hubbard, W. B.; Jokipii, J. R.

    1977-01-01

    Effects of atmospheric turbulence on stellar-occultation inversion procedures are investigated using a heuristic scattering model that is believed to reproduce the essential features of turbulence. A quantitative estimate is made of the size of the error in deducing the mean refractivity profile of a planetary atmosphere, taking into account constant as well as exponential scattering. It is shown that ordinary turbulence has no important effect on the average intensity profile in a stellar occultation but could have an important instantaneous effect. A critical examination of possible manifestations of turbulent scattering during occultations of Beta Sco by Jupiter indicates that all observed phenomena during these events can be understood in terms of scintillations produced by turbulence.

  17. Human and nature-caused hazards: the affect heuristic causes biased decisions.

    PubMed

    Siegrist, Michael; Sütterlin, Bernadette

    2014-08-01

    People are more concerned about the negative consequences of human hazards compared with natural hazards. Results of four experiments show that the same negative outcome (e.g., number of birds killed by an oil spill) was more negatively evaluated when caused by humans than when caused by nature. Results further show that when identical risk information was provided, participants evaluated nuclear power more negatively compared with solar power. The affect associated with the hazard per se influenced the interpretation of the new information. Furthermore, the affect experienced in the situation fully mediated the evaluation of the negative outcomes of a hazard. People's reliance on the affect heuristic is a challenge for acceptance of cost-benefit analyses because equally negative outcomes are differently evaluated depending on the cause. Symbolically significant information and the affect evoked by this information may result in biased and riskier decisions. PMID:24576178

  18. An illustrated heuristic prototype facilitates scientific inventive problem solving: A functional magnetic resonance imaging study.

    PubMed

    Tong, Dandan; Li, Wenfu; Tang, Chaoying; Yang, Wenjing; Tian, Yan; Zhang, Lei; Zhang, Meng; Qiu, Jiang; Liu, Yijun; Zhang, Qinglin

    2015-07-01

    Many scientific inventions (SI) throughout history were inspired by heuristic prototypes (HPs). For instance, an event or piece of knowledge similar to displaced water from a tub inspired Archimedes' principle. However, the neural mechanisms underlying this insightful problem solving are not very clear. Thus, the present study explored the neural correlates used to solve SI problems facilitated by HPs. Each HP had two versions: a literal description with an illustration (LDI) and a literal description with no illustration (LDNI). Thirty-two participants were divided randomly into these two groups. Blood oxygenation level-dependent fMRI contrasts between LDI and LDNI groups were measured. Greater activity in the right middle occipital gyrus (RMOG, BA19), right precentral gyrus (RPCG, BA4), and left middle frontal gyrus (LMFG, BA46) were found within the LDI group as compared to the LDNI group. We discuss these results in terms cognitive functions within these regions related to problem solving and memory retrieval. PMID:25840359

  19. Heuristic optimization of pressurized water reactor fuel cycle design under general constraints

    SciTech Connect

    Moon, H.; Levine, S.H. ); Mahgerefteh, M. )

    1989-12-01

    Optimization techniques in fuel management have directed modern fuel cycle designs to use low-leakage loading patterns. Future optimization calculations involving low-leakage patterns must utilize nucleonic models that are both fast operationally and rigorous. A two-dimensional two-group diffusion theory code is developed and lattice homogenization constants are generated using a modified LEOPARD code to fulfill these criteria. Based on these two codes, a heuristic optimization study is performed that considers the general constraints (e.g., spent-fuel storage limit and mechanical burnup limit) given to a utility fuel cycle designer. The optimum cycle length that minimizes the fuel cost is {approximately} 600 effective full-power days for the conditions assumed.

  20. A Multi-Inner-World Genetic Algorithm Using Multiple Heuristics to Optimize Delivery Schedule

    NASA Astrophysics Data System (ADS)

    Sakurai, Yoshitaka; Onoyama, Takashi; Tsukamoto, Natsuki; Takada, Kouhei; Tsuruta, Setsuo

    A delivery route optimization that improves the efficiency of real time delivery or a distribution network requires to solve several tens to hundreds cities Traveling Salesman Problems (TSP) (1)(2) within interactive response time, with expert-level accuracy (less than about 3% of error rate). To meet these requirements, a multi-inner-world Genetic Algorithm (Miw-GA) method is developed. This method combines several types of GA's inner worlds. Each world of this method uses a different type of heuristics such as a 2-opt type mutation world and a block (Nearest Insertion) type mutation world. Comparison based on the results of experiments proved the method is superior to others and our previously proposed method.

  1. Test Scheduling for Core-Based SOCs Using Genetic Algorithm Based Heuristic Approach

    NASA Astrophysics Data System (ADS)

    Giri, Chandan; Sarkar, Soumojit; Chattopadhyay, Santanu

    This paper presents a Genetic algorithm (GA) based solution to co-optimize test scheduling and wrapper design for core based SOCs. Core testing solutions are generated as a set of wrapper configurations, represented as rectangles with width equal to the number of TAM (Test Access Mechanism) channels and height equal to the corresponding testing time. A locally optimal best-fit heuristic based bin packing algorithm has been used to determine placement of rectangles minimizing the overall test times, whereas, GA has been utilized to generate the sequence of rectangles to be considered for placement. Experimental result on ITC'02 benchmark SOCs shows that the proposed method provides better solutions compared to the recent works reported in the literature.

  2. A Heuristic Indication and Warning Staging Model for Detection and Assessment of Biological Events

    PubMed Central

    Wilson, James M.; Polyak, Marat G.; Blake, Jane W.; Collmann, Jeff

    2008-01-01

    Objective This paper presents a model designed to enable rapid detection and assessment of biological threats that may require swift intervention by the international public health community. Design We utilized Strauss’ grounded theory to develop an expanded model of social disruption due to biological events based on retrospective and prospective case studies. We then applied this model to the temporal domain and propose a heuristic staging model, the Wilson–Collmann Scale for assessing biological event evolution. Measurements We retrospectively and manually examined hard copy archival local media reports in the native vernacular for three biological events associated with substantial social disruption. The model was then tested prospectively through media harvesting based on keywords corresponding to the model parameters. Results Our heuristic staging model provides valuable information about the features of a biological event that can be used to determine the level of concern warranted, such as whether the pathogen in question is responding to established public health disease control measures, including the use of antimicrobials or vaccines; whether the public health and medical infrastructure of the country involved is adequate to mount the necessary response; whether the country’s officials are providing an appropriate level of information to international public health authorities; and whether the event poses a international threat. The approach is applicable for monitoring open-source (public-domain) media for indications and warnings of such events, and specifically for markers of the social disruption that commonly occur as these events unfold. These indications and warnings can then be used as the basis for staging the biological threat in the same manner that the United States National Weather Service currently uses storm warning models (such as the Saffir-Simpson Hurricane Scale) to detect and assess threatening weather conditions. Conclusion

  3. A set-covering based heuristic algorithm for the periodic vehicle routing problem.

    PubMed

    Cacchiani, V; Hemmelmayr, V C; Tricoire, F

    2014-01-30

    We present a hybrid optimization algorithm for mixed-integer linear programming, embedding both heuristic and exact components. In order to validate it we use the periodic vehicle routing problem (PVRP) as a case study. This problem consists of determining a set of minimum cost routes for each day of a given planning horizon, with the constraints that each customer must be visited a required number of times (chosen among a set of valid day combinations), must receive every time the required quantity of product, and that the number of routes per day (each respecting the capacity of the vehicle) does not exceed the total number of available vehicles. This is a generalization of the well-known vehicle routing problem (VRP). Our algorithm is based on the linear programming (LP) relaxation of a set-covering-like integer linear programming formulation of the problem, with additional constraints. The LP-relaxation is solved by column generation, where columns are generated heuristically by an iterated local search algorithm. The whole solution method takes advantage of the LP-solution and applies techniques of fixing and releasing of the columns as a local search, making use of a tabu list to avoid cycling. We show the results of the proposed algorithm on benchmark instances from the literature and compare them to the state-of-the-art algorithms, showing the effectiveness of our approach in producing good quality solutions. In addition, we report the results on realistic instances of the PVRP introduced in Pacheco et al. (2011)  [24] and on benchmark instances of the periodic traveling salesman problem (PTSP), showing the efficacy of the proposed algorithm on these as well. Finally, we report the new best known solutions found for all the tested problems. PMID:24748696

  4. Optimization Model of Water Distribution System Using Heuristic Algorithm to Sketch Vulnerability Map

    NASA Astrophysics Data System (ADS)

    Hsieh, Y.-C.; Tung, C.-P.

    2012-04-01

    With the development of society, more and more people move to a city, which results in heavily increase of clean water demand. The study area, Kaohsiung city, is the second largest city with many industrial activities in Taiwan, and rainfall concentrates extremely in the wet season. The ratio of rainfall for wet and dry season is 9:1, and thus water supply for agriculture, industry and increasing population becomes more and more difficult while this city develops further and especially when droughts happen. To solve above problem, a robust pipe network with well-designed water supply distribution system becomes much more important. The purpose of this research is to find the optimal solution for water distribution system, which decides the amount of water for all nodes in the network and results in the smallest amount of people affected by shortage of water when the water network faces different degree of droughts. In this research, EPANET2 is used to simulate water distribution for different drought conditions. On the other hand, EPANET2 simulation and GIS population information are combined to calculate how many people are affected for each node in the network; then we can know the total affected people in the whole city for each water distribution alternative. Finally, heuristic algorithm is applied to find the optimal solution for different degree of droughts. Furthermore, by comparing the optimal solutions, the water supply vulnerability map can be drawn for Kaohsiung city, which reveals the weaker part of Kaohsiung and should be strengthened first for future extreme climate. Keywords: Water Supply Distribution System, Heuristic Algorithm, EPANET2, Vulnerability Map, and Optimization Model

  5. Automatic tuning of liver tissue model using simulated annealing and genetic algorithm heuristic approaches

    NASA Astrophysics Data System (ADS)

    Sulaiman, Salina; Bade, Abdullah; Lee, Rechard; Tanalol, Siti Hasnah

    2014-07-01

    Mass Spring Model (MSM) is a highly efficient model in terms of calculations and easy implementation. Mass, spring stiffness coefficient and damping constant are three major components of MSM. This paper focuses on identifying the coefficients of spring stiffness and damping constant using automated tuning method by optimization in generating human liver model capable of responding quickly. To achieve the objective two heuristic approaches are used, namely Simulated Annealing (SA) and Genetic Algorithm (GA) on the human liver model data set. The properties of the mechanical heart, which are taken into consideration, are anisotropy and viscoelasticity. Optimization results from SA and GA are then implemented into the MSM to model two human hearts, each with its SA or GA construction parameters. These techniques are implemented while making FEM construction parameters as benchmark. Step size response of both models are obtained after MSMs were solved using Fourth Order Runge-Kutta (RK4) to compare the elasticity response of both models. Remodelled time using manual calculation methods was compared against heuristic optimization methods of SA and GA in showing that model with automatic construction is more realistic in terms of realtime interaction response time. Liver models generated using SA and GA optimization techniques are compared with liver model from manual calculation. It shows that the reconstruction time required for 1000 repetitions of SA and GA is faster than the manual method. Meanwhile comparison between construction time of SA and GA model indicates that model SA is faster than GA with varying rates of time 0.110635 seconds/1000 repetitions. Real-time interaction of mechanical properties is dependent on rate of time and speed of remodelling process. Thus, the SA and GA have proven to be suitable in enhancing realism of simulated real-time interaction in liver remodelling.

  6. A simple heuristic for Internet-based evidence search in primary care: a randomized controlled trial

    PubMed Central

    Eberbach, Andreas; Becker, Annette; Rochon, Justine; Finkemeler, Holger; Wagner, Achim; Donner-Banzhoff, Norbert

    2016-01-01

    Background General practitioners (GPs) are confronted with a wide variety of clinical questions, many of which remain unanswered. Methods In order to assist GPs in finding quick, evidence-based answers, we developed a learning program (LP) with a short interactive workshop based on a simple three-step-heuristic to improve their search and appraisal competence (SAC). We evaluated the LP effectiveness with a randomized controlled trial (RCT). Participants (intervention group [IG] n=20; control group [CG] n=31) rated acceptance and satisfaction and also answered 39 knowledge questions to assess their SAC. We controlled for previous knowledge in content areas covered by the test. Results Main outcome – SAC: within both groups, the pre–post test shows significant (P=0.00) improvements in correctness (IG 15% vs CG 11%) and confidence (32% vs 26%) to find evidence-based answers. However, the SAC difference was not significant in the RCT. Other measures Most workshop participants rated “learning atmosphere” (90%), “skills acquired” (90%), and “relevancy to my practice” (86%) as good or very good. The LP-recommendations were implemented by 67% of the IG, whereas 15% of the CG already conformed to LP recommendations spontaneously (odds ratio 9.6, P=0.00). After literature search, the IG showed a (not significantly) higher satisfaction regarding “time spent” (IG 80% vs CG 65%), “quality of information” (65% vs 54%), and “amount of information” (53% vs 47%). Conclusion Long-standing established GPs have a good SAC. Despite high acceptance, strong learning effects, positive search experience, and significant increase of SAC in the pre–post test, the RCT of our LP showed no significant difference in SAC between IG and CG. However, we suggest that our simple decision heuristic merits further investigation. PMID:27563264

  7. Ovarian Hormone Fluctuation, Neurosteroids and HPA Axis Dysregulation in Perimenopausal Depression: A Novel Heuristic Model

    PubMed Central

    Gordon, Jennifer L.; Girdler, Susan S.; Meltzer-Brody, Samantha E.; Stika, Catherine S.; Thurston, Rebecca C.; Clark, Crystal T.; Prairie, Beth A.; Moses-Kolko, Eydie; Joffe, Hadine; Wisner, Katherine L.

    2015-01-01

    Objective In this conceptual review, we propose a novel mechanistic candidate in the etiology of depression with onset in the menopause transition (a.k.a. perimenopausal depression) involving alterations in stress-responsive pathways, induced by ovarian hormone fluctuation. Methods The relevant literature in perimenopausal depression was reviewed, including its prevalence, predictors, and treatment with estrogen therapy. Subsequently, the growing evidence from animal models and clinical research in other reproductive mood disorders was synthesized to describe a heuristic model of perimenopausal depression development. Results The rate of major depressive disorder and of clinically meaningful elevations in depressive symptoms increases two- to threefold during the menopause transition. While the mechanisms by which ovarian hormone fluctuation might impact mood are poorly understood, growing evidence from basic and clinical research suggests that fluctuations in ovarian hormones and their derived neurosteroids result in altered GABAergic regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Our heuristic model suggests that for some women, failure of the GABAA receptor to regulate overall GABAergic tone in the face of shifting levels of these neurosteroids may induce HPA axis dysfunction, thereby increasing sensitivity to stress, and generating a period of greater vulnerability to depression. Conclusions The proposed model provides a basis for understanding the mechanisms by which the changing hormonal environment of the menopause transition may interact with the psychosocial environment of mid-life to contribute to perimenopausal depression risk. Future research investigating this model may inform the development of novel pharmacological treatments for perimenopausal depression and related disorders such as postpartum depression and premenstrual dysphoric disorder. PMID:25585035

  8. An analysis on the load balancing strategies in wavelength-routed optical networks

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Fu, Minglei; Le, Zichun

    2008-11-01

    Routing and wavelength assignment (RWA) is one of the key issues in the wavelength-routed optical networks. Although some RWA algorithms have been well performed to meet the need of certain networks requirement, they usually neglect the performance of the whole networks, especially the load balancing of the whole networks. This is quite likely to lead to some links bearing excessive ligthpaths and traffic load, while other links being at an idle state. In this paper, the load distribution vector ( LDV ) is introduced to describe the links load of the networks firstly. Then by means of minimizing the LDV of the networks, the load balancing of the whole networks is tried to improve. Based on this, a heuristic load balancing (HLB) strategy is presented. Moreover, a novel RWA algorithm adopting the heuristic load balancing strategy is developed, as well as two other RWA algorithms adopting other load balancing strategies. At last, the simulations of the three RWA algorithms with different load balancing strategies are done for comparison on the basis of both the regular topology and the irregular topology networks. The simulation results show that the key performance parameters such as the average variance of links, the maximum link load and the number of established lightpath are improved by means of our novel RWA algorithm with the heuristic load balancing strategy.

  9. How should "hot" players in basketball be defended? The use of fast-and-frugal heuristics by basketball coaches and players in response to streakiness.

    PubMed

    Csapo, Peter; Avugos, Simcha; Raab, Markus; Bar-Eli, Michael

    2015-01-01

    Previous research has shown that changes in shot difficulty may have rendered the hot-hand effect in basketball unobservable and are potentially a result of defensive adjustments. However, it has not been directly analysed whether strategic changes indeed take place in response to streakiness and whether they are effective with respect to winning games. The current work consists of an experimental study with 18 professional coaches and 20 players based on video sequences from National Basketball Association games, where the shown player displayed a streaky performance in half of the sequences. While coaches were asked to devise a defensive strategy after each viewed sequence, players had to assume the role of the shown player and decide whether to shoot or pass the ball. We find that coaches tended to increase the defensive pressure significantly more often on presumably hot players and thus make use of the hot-hand heuristic. Meanwhile, players chose to shoot more frequently in low-pressure and streaky situations but selected "pass" regardless of the previous performance when they faced increased defensive pressure. Assuming that a streaky player's performance is indeed elevated during hot phases, hot-hand behaviour can be considered adaptive in certain situations as it led hot players to pass instead of shoot. PMID:25567138

  10. Two-edge disjoint survivable network design problem with relays: a hybrid genetic algorithm and Lagrangian heuristic approach

    NASA Astrophysics Data System (ADS)

    Konak, Abdullah

    2014-01-01

    This article presents a network design problem with relays considering the two-edge network connectivity. The problem arises in telecommunications and logistic networks where a constraint is imposed on the distance that a commodity can travel on a route without being processed by a relay, and the survivability of the network is critical in case of a component failure. The network design problem involves selecting two-edge disjoint paths between source and destination node pairs and determining the location of relays to minimize the network design cost. The formulated problem is solved by a hybrid approach of a genetic algorithm (GA) and a Lagrangian heuristic such that the GA searches for two-edge disjoint paths for each commodity, and the Lagrangian heuristic is used to determine relays on these paths. The performance of the proposed hybrid approach is compared to the previous approaches from the literature, with promising results.

  11. Solving large-scale fixed cost integer linear programming models for grid-based location problems with heuristic techniques

    NASA Astrophysics Data System (ADS)

    Noor-E-Alam, Md.; Doucette, John

    2015-08-01

    Grid-based location problems (GBLPs) can be used to solve location problems in business, engineering, resource exploitation, and even in the field of medical sciences. To solve these decision problems, an integer linear programming (ILP) model is designed and developed to provide the optimal solution for GBLPs considering fixed cost criteria. Preliminary results show that the ILP model is efficient in solving small to moderate-sized problems. However, this ILP model becomes intractable in solving large-scale instances. Therefore, a decomposition heuristic is proposed to solve these large-scale GBLPs, which demonstrates significant reduction of solution runtimes. To benchmark the proposed heuristic, results are compared with the exact solution via ILP. The experimental results show that the proposed method significantly outperforms the exact method in runtime with minimal (and in most cases, no) loss of optimality.

  12. The enduring value of Gánti's chemoton model and life criteria: Heuristic pursuit of exact theoretical biology.

    PubMed

    Griesemer, James

    2015-09-21

    Gánti's chemoton model of the minimal chemical organization of living systems and life criteria for the living state and a living world are characterized. It is argued that these are better interpreted as part of a heuristic pursuit of an exact theoretical biology than as a "definition of life." Several problems with efforts to define life are discussed. Clarifying the proper use of Gánti's ideas to serve constructive engineering idealizations helps to show their enduring value. PMID:25997793

  13. Helping Reasoners Succeed in the Wason Selection Task: When Executive Learning Discourages Heuristic Response but Does Not Necessarily Encourage Logic

    PubMed Central

    Rossi, Sandrine; Cassotti, Mathieu; Moutier, Sylvain; Delcroix, Nicolas; Houdé, Olivier

    2015-01-01

    Reasoners make systematic logical errors by giving heuristic responses that reflect deviations from the logical norm. Influential studies have suggested first that our reasoning is often biased because we minimize cognitive effort to surpass a cognitive conflict between heuristic response from system 1 and analytic response from system 2 thinking. Additionally, cognitive control processes might be necessary to inhibit system 1 responses to activate a system 2 response. Previous studies have shown a significant effect of executive learning (EL) on adults who have transferred knowledge acquired on the Wason selection task (WST) to another isomorphic task, the rule falsification task (RFT). The original paradigm consisted of teaching participants to inhibit a classical matching heuristic that sufficed the first problem and led to significant EL transfer on the second problem. Interestingly, the reasoning tasks differed in inhibiting-heuristic metacognitive cost. Success on the WST requires half-suppression of the matching elements. In contrast, the RFT necessitates a global rejection of the matching elements for a correct answer. Therefore, metacognitive learning difficulty most likely differs depending on whether one uses the first or second task during the learning phase. We aimed to investigate this difficulty and various matching-bias inhibition effects in a new (reversed) paradigm. In this case, the transfer effect from the RFT to the WST could be more difficult because the reasoner learns to reject all matching elements in the first task. We observed that the EL leads to a significant reduction in matching selections on the WST without increasing logical performances. Interestingly, the acquired metacognitive knowledge was too “strictly” transferred and discouraged matching rather than encouraging logic. This finding underlines the complexity of learning transfer and adds new evidence to the pedagogy of reasoning. PMID:25849555

  14. LateBiclustering: Efficient Heuristic Algorithm for Time-Lagged Bicluster Identification.

    PubMed

    Gonçalves, Joana P; Madeira, Sara C

    2014-01-01

    Identifying patterns in temporal data is key to uncover meaningful relationships in diverse domains, from stock trading to social interactions. Also of great interest are clinical and biological applications, namely monitoring patient response to treatment or characterizing activity at the molecular level. In biology, researchers seek to gain insight into gene functions and dynamics of biological processes, as well as potential perturbations of these leading to disease, through the study of patterns emerging from gene expression time series. Clustering can group genes exhibiting similar expression profiles, but focuses on global patterns denoting rather broad, unspecific responses. Biclustering reveals local patterns, which more naturally capture the intricate collaboration between biological players, particularly under a temporal setting. Despite the general biclustering formulation being NP-hard, considering specific properties of time series has led to efficient solutions for the discovery of temporally aligned patterns. Notably, the identification of biclusters with time-lagged patterns, suggestive of transcriptional cascades, remains a challenge due to the combinatorial explosion of delayed occurrences. Herein, we propose LateBiclustering, a sensible heuristic algorithm enabling a polynomial rather than exponential time solution for the problem. We show that it identifies meaningful time-lagged biclusters relevant to the response of Saccharomyces cerevisiae to heat stress. PMID:26356854

  15. Amoeba-Inspired Heuristic Search Dynamics for Exploring Chemical Reaction Paths

    NASA Astrophysics Data System (ADS)

    Aono, Masashi; Wakabayashi, Masamitsu

    2015-09-01

    We propose a nature-inspired model for simulating chemical reactions in a computationally resource-saving manner. The model was developed by extending our previously proposed heuristic search algorithm, called "AmoebaSAT [Aono et al. 2013]," which was inspired by the spatiotemporal dynamics of a single-celled amoeboid organism that exhibits sophisticated computing capabilities in adapting to its environment efficiently [Zhu et al. 2013]. AmoebaSAT is used for solving an NP-complete combinatorial optimization problem [Garey and Johnson 1979], "the satisfiability problem," and finds a constraint-satisfying solution at a speed that is dramatically faster than one of the conventionally known fastest stochastic local search methods [Iwama and Tamaki 2004] for a class of randomly generated problem instances [http://www.cs.ubc.ca/~hoos/5/benchm.html]. In cases where the problem has more than one solution, AmoebaSAT exhibits dynamic transition behavior among a variety of the solutions. Inheriting these features of AmoebaSAT, we formulate "AmoebaChem," which explores a variety of metastable molecules in which several constraints determined by input atoms are satisfied and generates dynamic transition processes among the metastable molecules. AmoebaChem and its developed forms will be applied to the study of the origins of life, to discover reaction paths for which expected or unexpected organic compounds may be formed via unknown unstable intermediates and to estimate the likelihood of each of the discovered paths.

  16. Using the Science Writing Heuristic to Improve Undergraduate Writing in Biology

    NASA Astrophysics Data System (ADS)

    Cronje, Ruth; Murray, Kelly; Rohlinger, Spencer; Wellnitz, Todd

    2013-11-01

    Our objective was to investigate the impact of the Science Writing Heuristic (SWH) on undergraduates' ability to express logical conclusions and include appropriate evidence in formal writing assignments. Students in three laboratory sections were randomly allocated to the SWH treatment (n = 51 students) with another three sections serving as a control (n = 47 students). All sections received an identical formal writing assignment to report results of laboratory activities. Four blinded raters used a 6-point rating scheme to evaluate the quality of students' writing performance. Raters' independent scoring agreement was evaluated using Cronbach's α. Paper scores were compared using a t-test, then papers were combined into low-scoring (3.5 of 6 points) or high-scoring (>3.5 of 6 points) sets and SWH and control cohorts were compared using Pearson's chi-square test. Papers from the SWH cohort were significantly (P = 0.02) more likely to receive a high score than those from the control cohort. Overall scores of SWH cohort papers tended to be higher (P = 0.07) than those from the control cohort. Gains in student conceptual understanding elicited by the SWH approach improved student ability to express logical conclusions about their data and include appropriate evidence to support those conclusions in formal research reports. Extending the writing tasks of the SWH to formal writing assignments can improve the ability of undergraduates to argue effectively for their research findings.

  17. Hierarchical heuristic search using a Gaussian mixture model for UAV coverage planning.

    PubMed

    Lin, Lanny; Goodrich, Michael A

    2014-12-01

    During unmanned aerial vehicle (UAV) search missions, efficient use of UAV flight time requires flight paths that maximize the probability of finding the desired subject. The probability of detecting the desired subject based on UAV sensor information can vary in different search areas due to environment elements like varying vegetation density or lighting conditions, making it likely that the UAV can only partially detect the subject. This adds another dimension of complexity to the already difficult (NP-Hard) problem of finding an optimal search path. We present a new class of algorithms that account for partial detection in the form of a task difficulty map and produce paths that approximate the payoff of optimal solutions. The algorithms use the mode goodness ratio heuristic that uses a Gaussian mixture model to prioritize search subregions. The algorithms search for effective paths through the parameter space at different levels of resolution. We compare the performance of the new algorithms against two published algorithms (Bourgault's algorithm and LHC-GW-CONV algorithm) in simulated searches with three real search and rescue scenarios, and show that the new algorithms outperform existing algorithms significantly and can yield efficient paths that yield payoffs near the optimal. PMID:24691199

  18. Heuristics-enhanced dead-reckoning (HEDR) for accurate position tracking of tele-operated UGVs

    NASA Astrophysics Data System (ADS)

    Borenstein, Johann; Borrell, Adam; Miller, Russell; Thomas, David

    2010-04-01

    This paper introduces a new approach for precision indoor tracking of tele-operated robots, called "Heuristics-Enhanced Dead-reckoning" (HEDR). HEDR does not rely on GPS, or external references; it uses odometry and a low-cost MEMS-based gyro. Our method corrects heading errors incurred by the high drift rate of the gyro by exploiting the structured nature of most indoor environments, but without having to directly measure features of the environment. The only operator feedback offered by most tele-operated robots is the view from a low to the ground onboard camera. Live video lets the operator observe the robot's immediate surroundings, but does not establish the orientation or whereabouts of the robot in its environment. Mentally keeping track of the robot's trajectory is difficult, and operators easily become disoriented. Our goal is to provide the tele-operator with a map view of the robot's current location and heading, as well as its previous trajectory, similar to the information provided by an automotive GPS navigation system. This frees tele-operators to focus on controlling the robot and achieving other mission goals, and provides the precise location of the robot if it becomes disabled and needs to be recovered.

  19. Using the Science Writing Heuristic Approach to Enhance Student Understanding in Chemical Change and Mixture

    NASA Astrophysics Data System (ADS)

    Kingir, Sevgi; Geban, Omer; Gunel, Murat

    2013-08-01

    This study investigated the effect of the Science Writing Heuristic (SWH) approach on grade 9 students' understanding of chemical change and mixture concepts. Four intact classes taught by two chemistry teachers from a Turkish public high school were selected for the study; one class was assigned as the treatment group, and the other class was assigned as the comparison group. Students in the treatment group were instructed by the SWH approach, while those in the comparison group were instructed with traditionally designed chemistry instruction. Tests measuring students' conceptual understanding in the units of chemical change and mixture were administered as pre- and posttest for both groups. At the end of the instruction, semistructured interviews were conducted with 13 students from the treatment group and eight students from the comparison group. ANCOVA results revealed that the SWH approach was superior to the traditional approach on students' understanding of chemical change and mixture concepts. Interview results indicated that students in the treatment group demonstrated better scientific understanding of chemical change and mixture concepts compared to those in the comparison group.

  20. Meta-heuristic CRPS minimization for the calibration of short-range probabilistic forecasts

    NASA Astrophysics Data System (ADS)

    Mohammadi, Seyedeh Atefeh; Rahmani, Morteza; Azadi, Majid

    2016-01-01

    This paper deals with the probabilistic short-range temperature forecasts over synoptic meteorological stations across Iran using non-homogeneous Gaussian regression (NGR). NGR creates a Gaussian forecast probability density function (PDF) from the ensemble output. The mean of the normal predictive PDF is a bias-corrected weighted average of the ensemble members and its variance is a linear function of the raw ensemble variance. The coefficients for the mean and variance are estimated by minimizing the continuous ranked probability score (CRPS) during a training period. CRPS is a scoring rule for distributional forecasts. In the paper of Gneiting et al. (Mon Weather Rev 133:1098-1118, 2005), Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is used to minimize the CRPS. Since BFGS is a conventional optimization method with its own limitations, we suggest using the particle swarm optimization (PSO), a robust meta-heuristic method, to minimize the CRPS. The ensemble prediction system used in this study consists of nine different configurations of the weather research and forecasting model for 48-h forecasts of temperature during autumn and winter 2011 and 2012. The probabilistic forecasts were evaluated using several common verification scores including Brier score, attribute diagram and rank histogram. Results show that both BFGS and PSO find the optimal solution and show the same evaluation scores, but PSO can do this with a feasible random first guess and much less computational complexity.

  1. A heuristic evaluation of long-term global sea level acceleration

    NASA Astrophysics Data System (ADS)

    Spada, Giorgio; Olivieri, Marco; Galassi, Gaia

    2015-05-01

    In view of the scientific and social implications, the global mean sea level rise (GMSLR) and its possible causes and future trend have been a challenge for so long. For the twentieth century, reconstructions generally indicate a rate of GMSLR in the range of 1.5 to 2.0 mm yr-1. However, the existence of nonlinear trends is still debated, and current estimates of the secular acceleration are subject to ample uncertainties. Here we use various GMSLR estimates published on scholarly journals since the 1940s for a heuristic assessment of global sea level acceleration. The approach, alternative to sea level reconstructions, is based on simple statistical methods and exploits the principles of meta-analysis. Our results point to a global sea level acceleration of 0.54 ± 0.27 mm/yr/century (1σ) between 1898 and 1975. This supports independent estimates and suggests that a sea level acceleration since the early 1900s is more likely than currently believed.

  2. A heuristic approach using multiple criteria for environmentally benign 3PLs selection

    NASA Astrophysics Data System (ADS)

    Kongar, Elif

    2005-11-01

    Maintaining competitiveness in an environment where price and quality differences between competing products are disappearing depends on the company's ability to reduce costs and supply time. Timely responses to rapidly changing market conditions require an efficient Supply Chain Management (SCM). Outsourcing logistics to third-party logistics service providers (3PLs) is one commonly used way of increasing the efficiency of logistics operations, while creating a more "core competency focused" business environment. However, this alone may not be sufficient. Due to recent environmental regulations and growing public awareness regarding environmental issues, 3PLs need to be not only efficient but also environmentally benign to maintain companies' competitiveness. Even though an efficient and environmentally benign combination of 3PLs can theoretically be obtained using exhaustive search algorithms, heuristics approaches to the selection process may be superior in terms of the computational complexity. In this paper, a hybrid approach that combines a multiple criteria Genetic Algorithm (GA) with Linear Physical Weighting Algorithm (LPPW) to be used in efficient and environmentally benign 3PLs is proposed. A numerical example is also provided to illustrate the method and the analyses.

  3. A Heuristic Ranking Approach on Capacity Benefit Margin Determination Using Pareto-Based Evolutionary Programming Technique

    PubMed Central

    Othman, Muhammad Murtadha; Abd Rahman, Nurulazmi; Musirin, Ismail; Fotuhi-Firuzabad, Mahmud; Rajabi-Ghahnavieh, Abbas

    2015-01-01

    This paper introduces a novel multiobjective approach for capacity benefit margin (CBM) assessment taking into account tie-line reliability of interconnected systems. CBM is the imperative information utilized as a reference by the load-serving entities (LSE) to estimate a certain margin of transfer capability so that a reliable access to generation through interconnected system could be attained. A new Pareto-based evolutionary programming (EP) technique is used to perform a simultaneous determination of CBM for all areas of the interconnected system. The selection of CBM at the Pareto optimal front is proposed to be performed by referring to a heuristic ranking index that takes into account system loss of load expectation (LOLE) in various conditions. Eventually, the power transfer based available transfer capability (ATC) is determined by considering the firm and nonfirm transfers of CBM. A comprehensive set of numerical studies are conducted on the modified IEEE-RTS79 and the performance of the proposed method is numerically investigated in detail. The main advantage of the proposed technique is in terms of flexibility offered to an independent system operator in selecting an appropriate solution of CBM simultaneously for all areas. PMID:25879068

  4. Two fast and accurate heuristic RBF learning rules for data classification.

    PubMed

    Rouhani, Modjtaba; Javan, Dawood S

    2016-03-01

    This paper presents new Radial Basis Function (RBF) learning methods for classification problems. The proposed methods use some heuristics to determine the spreads, the centers and the number of hidden neurons of network in such a way that the higher efficiency is achieved by fewer numbers of neurons, while the learning algorithm remains fast and simple. To retain network size limited, neurons are added to network recursively until termination condition is met. Each neuron covers some of train data. The termination condition is to cover all training data or to reach the maximum number of neurons. In each step, the center and spread of the new neuron are selected based on maximization of its coverage. Maximization of coverage of the neurons leads to a network with fewer neurons and indeed lower VC dimension and better generalization property. Using power exponential distribution function as the activation function of hidden neurons, and in the light of new learning approaches, it is proved that all data became linearly separable in the space of hidden layer outputs which implies that there exist linear output layer weights with zero training error. The proposed methods are applied to some well-known datasets and the simulation results, compared with SVM and some other leading RBF learning methods, show their satisfactory and comparable performance. PMID:26797472

  5. A self-adapting heuristic for automatically constructing terrain appreciation exercises

    NASA Astrophysics Data System (ADS)

    Nanda, S.; Lickteig, C. L.; Schaefer, P. S.

    2008-04-01

    Appreciating terrain is a key to success in both symmetric and asymmetric forms of warfare. Training to enable Soldiers to master this vital skill has traditionally required their translocation to a selected number of areas, each affording a desired set of topographical features, albeit with limited breadth of variety. As a result, the use of such methods has proved to be costly and time consuming. To counter this, new computer-aided training applications permit users to rapidly generate and complete training exercises in geo-specific open and urban environments rendered by high-fidelity image generation engines. The latter method is not only cost-efficient, but allows any given exercise and its conditions to be duplicated or systematically varied over time. However, even such computer-aided applications have shortcomings. One of the principal ones is that they usually require all training exercises to be painstakingly constructed by a subject matter expert. Furthermore, exercise difficulty is usually subjectively assessed and frequently ignored thereafter. As a result, such applications lack the ability to grow and adapt to the skill level and learning curve of each trainee. In this paper, we present a heuristic that automatically constructs exercises for identifying key terrain. Each exercise is created and administered in a unique iteration, with its level of difficulty tailored to the trainee's ability based on the correctness of that trainee's responses in prior iterations.

  6. Meta-heuristic CRPS minimization for the calibration of short-range probabilistic forecasts

    NASA Astrophysics Data System (ADS)

    Mohammadi, Seyedeh Atefeh; Rahmani, Morteza; Azadi, Majid

    2016-08-01

    This paper deals with the probabilistic short-range temperature forecasts over synoptic meteorological stations across Iran using non-homogeneous Gaussian regression (NGR). NGR creates a Gaussian forecast probability density function (PDF) from the ensemble output. The mean of the normal predictive PDF is a bias-corrected weighted average of the ensemble members and its variance is a linear function of the raw ensemble variance. The coefficients for the mean and variance are estimated by minimizing the continuous ranked probability score (CRPS) during a training period. CRPS is a scoring rule for distributional forecasts. In the paper of Gneiting et al. (Mon Weather Rev 133:1098-1118, 2005), Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is used to minimize the CRPS. Since BFGS is a conventional optimization method with its own limitations, we suggest using the particle swarm optimization (PSO), a robust meta-heuristic method, to minimize the CRPS. The ensemble prediction system used in this study consists of nine different configurations of the weather research and forecasting model for 48-h forecasts of temperature during autumn and winter 2011 and 2012. The probabilistic forecasts were evaluated using several common verification scores including Brier score, attribute diagram and rank histogram. Results show that both BFGS and PSO find the optimal solution and show the same evaluation scores, but PSO can do this with a feasible random first guess and much less computational complexity.

  7. Heuristic modeling of spectral plasma emission for laser-induced breakdown spectroscopy

    SciTech Connect

    Wester, Rolf; Noll, Reinhard

    2009-12-15

    A heuristic model was developed to describe the spectral emission of laser-induced plasmas generated for laser-induced breakdown spectroscopy under the assumption that the composition of the plasma and the plasma state is known. The plasma is described by a stationary spherical shell model surrounded by an ambient gas, which partially absorbs the emitted radiation. The radiation transport equation is used to calculate the spectrum emitted by the plasma. Simulations of a multiline iron spectrum and a self-reversed Al line are compared with experimental spectra. For the iron spectrum, the degree of congruence is moderate to good, which may be attributed to a lack of precise atomic and Stark broadening data as well as a simplified plasma model. The line profile of the Al resonance line with self reversal can be simulated with a high degree of agreement. Simulated spectra of a steel sample in the vacuum ultraviolet spectral range demonstrate the strong influence of the ambient atmosphere in the spectral range between 178 and 194 nm. The number of free parameters of the plasma model of 8 can be further reduced down to 3, taking into account the integral parameters of the plasma that are accessible experimentally.

  8. Damage identification of a TLP floating wind turbine by meta-heuristic algorithms

    NASA Astrophysics Data System (ADS)

    Ettefagh, M. M.

    2015-12-01

    Damage identification of the offshore floating wind turbine by vibration/dynamic signals is one of the important and new research fields in the Structural Health Monitoring (SHM). In this paper a new damage identification method is proposed based on meta-heuristic algorithms using the dynamic response of the TLP (Tension-Leg Platform) floating wind turbine structure. The Genetic Algorithms (GA), Artificial Immune System (AIS), Particle Swarm Optimization (PSO), and Artificial Bee Colony (ABC) are chosen for minimizing the object function, defined properly for damage identification purpose. In addition to studying the capability of mentioned algorithms in correctly identifying the damage, the effect of the response type on the results of identification is studied. Also, the results of proposed damage identification are investigated with considering possible uncertainties of the structure. Finally, for evaluating the proposed method in real condition, a 1/100 scaled experimental setup of TLP Floating Wind Turbine (TLPFWT) is provided in a laboratory scale and the proposed damage identification method is applied to the scaled turbine.

  9. Theoretical aspects and practical implications of the heuristic drift SOL model

    NASA Astrophysics Data System (ADS)

    Goldston, R. J.

    2015-08-01

    The heuristic drift (HD) model for the tokamak power scrape-off layer width provides remarkable agreement in both absolute magnitude and scalings with the measured width of the exponential component of the heat flux at divertors targets, in low gas-puff H-Mode tokamaks. This motivates further exploration of its theoretical aspects and practical implications. The HD model requires a small non-ambipolar electron particle diffusivity ∼10-2 m2/s. It also implies large parallel heat flux in ITER and suggests that more radical approaches will be needed to handle the ∼20 GW/m2 parallel heat flux expected in Demo. Remarkably, the HD model is also in good agreement with recent near-SOL heat flux profiles measured in a number of limiter L-Mode experiments, implying ubiquity of the underlying mechanism. Finally, the HD model suggests that the H-Mode and more generally Greenwald density limit may be caused by MHD instability in the SOL, rather than originating in the core plasma or pedestal. If the SOL width in stellarators is set by magnetic topology rather than by drifts, this would be consistent with the absence of the Greenwald density limit in stellarators.

  10. Conceptual heuristic models of the interrelationships between obesity and the occupational environment

    PubMed Central

    Pandalai, Sudha P; Schulte, Paul A; Miller, Diane B

    2015-01-01

    Objective Research and interventions targeting the relationship between work, its attendant occupational hazards, and obesity are evolving but merit further consideration in the public health arena. In this discussion paper, conceptual heuristic models are described examining the role of obesity as both a risk factor and health outcome in the occupational setting. Methods PubMed was searched using specific criteria from 2000 and onwards for evidence to support conceptual models in which obesity serves as a risk factor for occupational disease or an outcome of occupational exposures. Nine models are presented: four where obesity is a risk factor and five where it is an adverse effect. Results A broad range of work-related health effects are associated with obesity including musculoskeletal disorders, asthma, liver disease, and cardiovascular disease, among others. Obesity can be associated with occupational hazards such as shift work, sedentary work, job stress, and exposure to some chemicals. Conclusion Identification of combinations of risk factors pertinent to obesity in the occupational environment will provide important guidance for research and prevention. PMID:23588858

  11. Ehrlichia Meningitis Mimicking Aneurysmal Subarachnoid Hemorrhage: A Case Study for Medical Decision-Making Heuristics.

    PubMed

    Dredla, Brynn; Freeman, William D

    2016-04-01

    Thunderclap headache is a sudden and severe headache that can occur after an aneurysmal subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage is a medical emergency that requires prompt attention and hospitalization. Patients with thunderclap headache often undergo a noncontrast head computed tomography (CT) scan to ascertain SAH bleeding and, if the scan is negative, then undergo a lumbar puncture to look for cerebrospinal fluid (CSF) red blood cells (RBCs), which would be consistent with an aneurysmal leak. If the initial CT is negative and CSF is positive for RBCs, patients are usually admitted to the hospital for evaluation of intracranial aneurysm. We encountered a patient with thunderclap headache whose initial head CT was negative for SAH and whose CSF tested positive for RBCs. The patient was referred to our center for evaluation and management of aneurysmal SAH. However, on careful review of the patient's medical history, serum laboratory values, and spinal fluid values, the patient was diagnosed with Ehrlichia chaffeensis meningitis. While Ehrlichia meningitis is rare, it is important to recognize the clinical clues that could help avoid formal cerebral angiography, a costly and potentially unnecessary procedure. We present how this case represented a cognitive framing bias and anchoring heuristic as well as steps that medical providers can use to prevent such cognitive errors in diagnosis. PMID:27053985

  12. Improving N(6)-methyladenosine site prediction with heuristic selection of nucleotide physical-chemical properties.

    PubMed

    Zhang, Ming; Sun, Jia-Wei; Liu, Zi; Ren, Ming-Wu; Shen, Hong-Bin; Yu, Dong-Jun

    2016-09-01

    N(6)-methyladenosine (m(6)A) is one of the most common and abundant post-transcriptional RNA modifications found in viruses and most eukaryotes. m(6)A plays an essential role in many vital biological processes to regulate gene expression. Because of its widespread distribution across the genomes, the identification of m(6)A sites from RNA sequences is of significant importance for better understanding the regulatory mechanism of m(6)A. Although progress has been achieved in m(6)A site prediction, challenges remain. This article aims to further improve the performance of m(6)A site prediction by introducing a new heuristic nucleotide physical-chemical property selection (HPCS) algorithm. The proposed HPCS algorithm can effectively extract an optimized subset of nucleotide physical-chemical properties under the prescribed feature representation for encoding an RNA sequence into a feature vector. We demonstrate the efficacy of the proposed HPCS algorithm under different feature representations, including pseudo dinucleotide composition (PseDNC), auto-covariance (AC), and cross-covariance (CC). Based on the proposed HPCS algorithm, we implemented an m(6)A site predictor, called M6A-HPCS, which is freely available at http://csbio.njust.edu.cn/bioinf/M6A-HPCS. Experimental results over rigorous jackknife tests on benchmark datasets demonstrated that the proposed M6A-HPCS achieves higher success rates and outperforms existing state-of-the-art sequence-based m(6)A site predictors. PMID:27293216

  13. Parsing heuristic and forward search in first-graders' game-play behavior.

    PubMed

    Paz, Luciano; Goldin, Andrea P; Diuk, Carlos; Sigman, Mariano

    2015-07-01

    Seventy-three children between 6 and 7 years of age were presented with a problem having ambiguous subgoal ordering. Performance in this task showed reliable fingerprints: (a) a non-monotonic dependence of performance as a function of the distance between the beginning and the end-states of the problem, (b) very high levels of performance when the first move was correct, and (c) states in which accuracy of the first move was significantly below chance. These features are consistent with a non-Markov planning agent, with an inherently inertial decision process, and that uses heuristics and partial problem knowledge to plan its actions. We applied a statistical framework to fit and test the quality of a proposed planning model (Monte Carlo Tree Search). Our framework allows us to parse out independent contributions to problem-solving based on the construction of the value function and on general mechanisms of the search process in the tree of solutions. We show that the latter are correlated with children's performance on an independent measure of planning, while the former is highly domain specific. PMID:25302559

  14. Energy-Efficient Next-Generation Passive Optical Networks Based on Sleep Mode and Heuristic Optimization

    NASA Astrophysics Data System (ADS)

    Zulai, Luis G. T.; Durand, Fábio R.; Abrão, Taufik

    2015-05-01

    In this article, an energy-efficiency mechanism for next-generation passive optical networks is investigated through heuristic particle swarm optimization. Ten-gigabit Ethernet-wavelength division multiplexing optical code division multiplexing-passive optical network next-generation passive optical networks are based on the use of a legacy 10-gigabit Ethernet-passive optical network with the advantage of using only an en/decoder pair of optical code division multiplexing technology, thus eliminating the en/decoder at each optical network unit. The proposed joint mechanism is based on the sleep-mode power-saving scheme for a 10-gigabit Ethernet-passive optical network, combined with a power control procedure aiming to adjust the transmitted power of the active optical network units while maximizing the overall energy-efficiency network. The particle swarm optimization based power control algorithm establishes the optimal transmitted power in each optical network unit according to the network pre-defined quality of service requirements. The objective is controlling the power consumption of the optical network unit according to the traffic demand by adjusting its transmitter power in an attempt to maximize the number of transmitted bits with minimum energy consumption, achieving maximal system energy efficiency. Numerical results have revealed that it is possible to save 75% of energy consumption with the proposed particle swarm optimization based sleep-mode energy-efficiency mechanism compared to 55% energy savings when just a sleeping-mode-based mechanism is deployed.

  15. An auto-focusing heuristic model to increase the reliability of a scientific mission

    NASA Astrophysics Data System (ADS)

    Gualdesi, Lavinio

    2006-11-01

    Researchers invest a lot of time and effort on the design and development of components used in a scientific mission. To capitalize on this investment and on the operational experience of the researchers, it is useful to adopt a quantitative data base to monitor the history and usage of the components. This work describes a model to monitor the reliability level of components. The model is very flexible and allows users to compose systems using the same components in different configurations as required by each mission. This tool provides availability and reliability figures for the configuration requested, derived from historical data of the components' previous performance. The system is based on preliminary checklists to establish standard operating procedures (SOP) for all components life phases. When an infringement to the SOP occurs, a quantitative ranking is provided in order to quantify the risk associated with this deviation. The final agreement between field data and expected performance of the component makes the model converge onto a heuristic monitoring system. The model automatically focuses on points of failure at the detailed component element level, calculates risks, provides alerts when a demonstrated risk to safety is encountered, and advises when there is a mismatch between component performance and mission requirements. This model also helps the mission to focus resources on critical tasks where they are most needed.

  16. A heuristic for constrained T-shape cutting patterns of circular items

    NASA Astrophysics Data System (ADS)

    Cui, Yaodong; Huang, Baixiong

    2011-08-01

    The cutting and stamping process is often used to divide metal plate into circular items. It contains the cutting and stamping stages. A guillotine machine divides the plate into strips at the cutting stage. Each strip contains items of the same type. A press stamps out the items from the strips at the stamping stage. T-shape patterns are often used at the cutting stage. A cut divides a T-shape pattern into an X-segment of horizontal strips and a Y-segment of vertical strips. The position of the dividing cut should be determined such that the pattern value is maximized. A heuristic for constrained T-shape patterns is presented. For each position of the dividing cut, it generates an optimal strip layout on the Y-segment using all items, and generates another optimal strip layout on the X-segment using the remaining items. Computational results indicate that the algorithm is efficient in improving material utilization.

  17. Optimizing the warranty period by cuckoo meta-heuristic algorithm in heterogeneous customers' population

    NASA Astrophysics Data System (ADS)

    Roozitalab, Ali; Asgharizadeh, Ezzatollah

    2013-12-01

    Warranty is now an integral part of each product. Since its length is directly related to the cost of production, it should be set in such a way that it would maximize revenue generation and customers' satisfaction. Furthermore, based on the behavior of customers, it is assumed that increasing the warranty period to earn the trust of more customers leads to more sales until the market is saturated. We should bear in mind that different groups of consumers have different consumption behaviors and that performance of the product has a direct impact on the failure rate over the life of the product. Therefore, the optimum duration for every group is different. In fact, we cannot present different warranty periods for various customer groups. In conclusion, using cuckoo meta-heuristic optimization algorithm, we try to find a common period for the entire population. Results with high convergence offer a term length that will maximize the aforementioned goals simultaneously. The study was tested using real data from Appliance Company. The results indicate a significant increase in sales when the optimization approach was applied; it provides a longer warranty through increased revenue from selling, not only reducing profit margins but also increasing it.

  18. A heuristic method for consumable resource allocation in multi-class dynamic PERT networks

    NASA Astrophysics Data System (ADS)

    Yaghoubi, Saeed; Noori, Siamak; Mazdeh, Mohammad Mahdavi

    2013-06-01

    This investigation presents a heuristic method for consumable resource allocation problem in multi-class dynamic Project Evaluation and Review Technique (PERT) networks, where new projects from different classes (types) arrive to system according to independent Poisson processes with different arrival rates. Each activity of any project is operated at a devoted service station located in a node of the network with exponential distribution according to its class. Indeed, each project arrives to the first service station and continues its routing according to precedence network of its class. Such system can be represented as a queuing network, while the discipline of queues is first come, first served. On the basis of presented method, a multi-class system is decomposed into several single-class dynamic PERT networks, whereas each class is considered separately as a minisystem. In modeling of single-class dynamic PERT network, we use Markov process and a multi-objective model investigated by Azaron and Tavakkoli-Moghaddam in 2007. Then, after obtaining the resources allocated to service stations in every minisystem, the final resources allocated to activities are calculated by the proposed method.

  19. Amoeba-Inspired Heuristic Search Dynamics for Exploring Chemical Reaction Paths.

    PubMed

    Aono, Masashi; Wakabayashi, Masamitsu

    2015-09-01

    We propose a nature-inspired model for simulating chemical reactions in a computationally resource-saving manner. The model was developed by extending our previously proposed heuristic search algorithm, called "AmoebaSAT [Aono et al. 2013]," which was inspired by the spatiotemporal dynamics of a single-celled amoeboid organism that exhibits sophisticated computing capabilities in adapting to its environment efficiently [Zhu et al. 2013]. AmoebaSAT is used for solving an NP-complete combinatorial optimization problem [Garey and Johnson 1979], "the satisfiability problem," and finds a constraint-satisfying solution at a speed that is dramatically faster than one of the conventionally known fastest stochastic local search methods [Iwama and Tamaki 2004] for a class of randomly generated problem instances [ http://www.cs.ubc.ca/~hoos/5/benchm.html ]. In cases where the problem has more than one solution, AmoebaSAT exhibits dynamic transition behavior among a variety of the solutions. Inheriting these features of AmoebaSAT, we formulate "AmoebaChem," which explores a variety of metastable molecules in which several constraints determined by input atoms are satisfied and generates dynamic transition processes among the metastable molecules. AmoebaChem and its developed forms will be applied to the study of the origins of life, to discover reaction paths for which expected or unexpected organic compounds may be formed via unknown unstable intermediates and to estimate the likelihood of each of the discovered paths. PMID:26129639

  20. Heuristic Search for Planning with Different Forced Goal-Ordering Constraints

    PubMed Central

    Zhang, Weiming; Cui, Jing; Zhu, Cheng; Huang, Jincai; Liu, Zhong

    2013-01-01

    Planning with forced goal-ordering (FGO) constraints has been proposed many times over the years, but there are still major difficulties in realizing these FGOs in plan generation. In certain planning domains, all the FGOs exist in the initial state. No matter which approach is adopted to achieve a subgoal, all the subgoals should be achieved in a given sequence from the initial state. Otherwise, the planning may arrive at a deadlock. For some other planning domains, there is no FGO in the initial state. However, FGO may occur during the planning process if certain subgoal is achieved by an inappropriate approach. This paper contributes to illustrate that it is the excludable constraints among the goal achievement operations (GAO) of different subgoals that introduce the FGOs into the planning problem, and planning with FGO is still a challenge for the heuristic search based planners. Then, a novel multistep forward search algorithm is proposed which can solve the planning problem with different FGOs efficiently. PMID:23935443