Geoscience Data Puzzles: Developing Students' Ability to Make Meaning from Data

Science.gov (United States)

Kastens, K. A.; Turrin, M.

2010-12-01

One of the most fundamental aspects of geoscience expertise is the ability to extract insights from observational earth data. Where an expert might see trends, patterns, processes, and candidate causal relationships, a novice could look at the same data representation and see dots, wiggles and blotches of color. The problem is compounded when the student was not personally involved in collecting the data or samples and thus has no experiential knowledge of the Earth setting that the data represent. In other words, the problem is especially severe when students tap into the vast archives of professionally-collected data that the geoscience community has worked so hard to make available for instructional use over the internet. Moreover, most high school and middle school teachers did not themselves learn Earth Science through analyzing data, and they may lack skills and/or confidence needed to scaffold students through the process of learning to interpret realistically-complex data sets. We have developed “Geoscience Data Puzzles” with the paired goals of (a) helping students learn about the earth from data, and (b) helping teachers learn to teach with data. Geoscience Data Puzzles are data-using activities that purposefully present a low barrier-to-entry for teachers and a high ratio of insight-to-effort for students. Each Puzzle uses authentic geoscience data, but the data are carefully pre-selected in order to illuminate a fundamental Earth process within tractable snippets of data. Every Puzzle offers "Aha" moments, when the connection between data and process comes clear in a rewarding burst of insight. Every Puzzle is accompanied by a Pedagogical Content Knowledge (PCK) guide, which explicates the chain of reasoning by which the puzzle-solver can use the evidence provided by the data to construct scientific claims. Four types of reasoning are stressed: spatial reasoning, in which students make inferences from observations about location, orientation, shape

Sublime Imperfections : Annotated Reading List

NARCIS (Netherlands)

Rutten, E.

2016-01-01

In this reading list, I share thoughts on scholars and journalists from which the Sublime Imperfections project takes its inspiration. The authors of the texts that I clustered ponder the nexus between the imperfect and the sublime, they rethink repair and breakdown, they critically interrogate and

The PPP Puzzle

DEFF Research Database (Denmark)

Juselius, Katarina

The persistent movements away from long-run benchmark values in real exchange rates, dubbed the PPP puzzle, observed in many real exchange rates during periods of currency float have been subject to much empirical research without resolving the puzzle. The paper demonstrates how the cointegrated...... VAR approach by grouping together components of similar persistence can be used to uncover structures in the data that ultimately may help to explain theoretically the forces underlying such puzzling movements. The charaterization of the data into components which are empirically I(0), I(1), and I(2......) is shown to be a powerful organizing principle allowing us to structure the data in long-run, medium-run, and short-run behavior. Its main advantage is the ability to associate persistent movements away from fundamental benchmark values in one variable/relation with similar persistent movements somewhere...

Basic Functional Analysis Puzzles of Spectral Flow

DEFF Research Database (Denmark)

Booss-Bavnbek, Bernhelm

2011-01-01

We explain an array of basic functional analysis puzzles on the way to general spectral flow formulae and indicate a direction of future topological research for dealing with these puzzles.......We explain an array of basic functional analysis puzzles on the way to general spectral flow formulae and indicate a direction of future topological research for dealing with these puzzles....

Astroparticle physics: puzzles and discoveries

International Nuclear Information System (INIS)

Berezinsky, V

2008-01-01

Puzzles often give birth to the great discoveries, the false discoveries sometimes stimulate the exiting ideas in theoretical physics. The historical examples of both are described in Introduction and in section 'Cosmological Puzzles'. From existing puzzles most attention is given to Ultra High Energy Cosmic Ray (UHECR) puzzle and to cosmological constant problem. The 40-years old UHECR problem consisted in absence of the sharp steepening in spectrum of extragalactic cosmic rays caused by interaction with CMB radiation. This steepening is known as Greisen-Zatsepin-Kuzmin (GZK) cutoff. It is demonstrated here that the features of interaction of cosmic ray protons with CMB are seen now in the spectrum in the form of the dip and beginning of the GZK cutoff. The most serious cosmological problem is caused by large vacuum energy of the known elementary-particle fields which exceeds at least by 45 orders of magnitude the cosmological vacuum energy. The various ideas put forward to solve this problem during last 40 years, have weaknesses and cannot be accepted as the final solution of this puzzle. The anthropic approach is discussed

Current puzzles in nuclear physics

International Nuclear Information System (INIS)

1985-01-01

A meeting on ''Current puzzles in nuclear physics'' was held at Research Center for Nuclear Physics, Osaka University, on June 27 - 28, 1984. The meeting put emphasis on several puzzles which have not been solved for a long time in nuclear physics, and also on the puzzles. This collective report is composed of following eleven papers presented at the meeting. Almost all the papers are witten in English : (1) M1, GT excitations and configuration mixing (in Japanese). (2) Hadronic excitation of pionic states. (3) Microscopic analyses of 28 Si(α,α') 28 Si scattering and single particle strength in A = 29 nuclei. (4) Few-body physics and its incentives to nuclear physics. (5) Is it necessary to introduce three body interactions ? (in Japanese). (6) Puzzles in the neutron-deuteron elastic scattering. (7) Puzzles in NN, NΔ, πN and Nanti N interactions. (8) Problems in Hadron-Nucleus interaction. (9) Unified approach to the meson- and quark- theory of nuclear forces and currents. (10) Pion photoproduction in two Chiral bag models. (11) The dynamic bag model : The electromagnetic properties of nucleon. (Aoki, K.)

Traditional theory about the origin of the Latin imperfect

Directory of Open Access Journals (Sweden)

Matej Hribersek

2003-12-01

Full Text Available The imperfect tense expresses a continuous past action which is unfinished, as the name itself indicates - im-perfectum. This characteristic accounts for its three uses: a  pure, durative imperfect b  iterative imperfect and c  imperfect de conatu. These uses are best preserved  in Greek but were also used in Latin, where the forms of the old imperfect  disappeared.  In Proto-Germanic,  the IE imperfect, the aorist and the perfect  continue partly in the old perfect  and partly in its counterpart, the preterite,  while, in Proto-Slavonic,  the old imperfect for non­ momentary  actions was replaced  by forms ending in *-ahb.lIn Italic languages, the functions  of the IE imperfect  passed  on into the compounds with  *bh7Jam.

The Anatomy Puzzle Book.

Science.gov (United States)

Jacob, Willis H.; Carter, Robert, III

This document features review questions, crossword puzzles, and word search puzzles on human anatomy. Topics include: (1) Anatomical Terminology; (2) The Skeletal System and Joints; (3) The Muscular System; (4) The Nervous System; (5) The Eye and Ear; (6) The Circulatory System and Blood; (7) The Respiratory System; (8) The Urinary System; (9) The…

Tangrams: Puzzles of Art

Science.gov (United States)

Fee, Brenda

2009-01-01

Challenging one's brain is the beginning of making great art. Tangrams are a great way to keep students thinking about their latest art project long after leaving the classroom. A tangram is a Chinese puzzle. The earliest known reference to tangrams appears in a Chinese book dated 1813, but the puzzles existed long before that date. The puzzle…

Stress in pressurized spheres with imperfections

International Nuclear Information System (INIS)

Godoy, L.A.; Flores, F.G.

1986-01-01

Stresses due to geometric imperfections in pressurized thin spherical shells, which are used in containments of nuclear reactors and steam generation systems are studied. The analysis is carried out discretizing the imperfect geometry by finite element method. (Author) [pt

Imperfect information facilitates the evolution of reciprocity.

Science.gov (United States)

Kurokawa, Shun

2016-06-01

The existence of cooperation demands explanation since cooperation is costly to the actor. Reciprocity has long been regarded as a potential explanatory mechanism for the existence of cooperation. Reciprocity is a mechanism wherein a cooperator responds to an opponent's behavior by switching his/her own behavior. Hence, a possible problematic case relevant to the theory of reciprocity evolution arises when the mechanism is such that the information regarding an opponent's behavior is imperfect. Although it has been confirmed also by previous theoretical studies that imperfect information interferes with the evolution of reciprocity, this argument is based on the assumption that there are no mistakes in behavior. And, a previous study presumed that it might be expected that when such mistakes occur, reciprocity can more readily evolve in the case of imperfect information than in the case of perfect information. The reason why the previous study considers so is that in the former case, reciprocators can miss defections incurred by other reciprocators' mistakes due to imperfect information, allowing cooperation to persist when such reciprocators meet. However, contrary to this expectation, the previous study has shown that even when mistakes occur, imperfect information interferes with the evolution of reciprocity. Nevertheless, the previous study assumed that payoffs are linear (i.e., that the effect of behavior is additive and there are no synergetic effects). In this study, we revisited the same problem but removed the assumption that payoffs are linear. We used evolutionarily stable strategy analysis to compare the condition for reciprocity to evolve when mistakes occur and information is imperfect with the condition for reciprocity to evolve when mistakes occur and information is perfect. Our study revealed that when payoffs are not linear, imperfect information can facilitate the evolution of reciprocity when mistakes occur; while when payoffs are linear

Dynamic imperfections and optimized feedback design in the Compact Linear Collider main linac

Directory of Open Access Journals (Sweden)

Peder Eliasson

2008-05-01

Full Text Available The Compact Linear Collider (CLIC main linac is sensitive to dynamic imperfections such as element jitter, injected beam jitter, and ground motion. These effects cause emittance growth that, in case of ground motion, has to be counteracted by a trajectory feedback system. The feedback system itself will, due to jitter effects and imperfect beam position monitors (BPMs, indirectly cause emittance growth. Fast and accurate simulations of both the direct and indirect effects are desirable, but due to the many elements of the CLIC main linac, simulations may become very time consuming. In this paper, an efficient way of simulating linear (or nearly linear dynamic effects is described. The method is also shown to facilitate the analytic determination of emittance growth caused by the different dynamic imperfections while using a trajectory feedback system. Emittance growth expressions are derived for quadrupole, accelerating structure, and beam jitter, for ground motion, and for noise in the feedback BPMs. Finally, it is shown how the method can be used to design a feedback system that is optimized for the optics of the machine and the ground motion spectrum of the particular site. This feedback system gives an emittance growth rate that is approximately 10 times lower than that of traditional trajectory feedbacks. The robustness of the optimized feedback system is studied for a number of additional imperfections, e.g., dipole corrector imperfections and faulty knowledge about the machine optics, with promising results.

Dynamic imperfections and optimized feedback design in the Compact Linear Collider main linac

Science.gov (United States)

Eliasson, Peder

2008-05-01

The Compact Linear Collider (CLIC) main linac is sensitive to dynamic imperfections such as element jitter, injected beam jitter, and ground motion. These effects cause emittance growth that, in case of ground motion, has to be counteracted by a trajectory feedback system. The feedback system itself will, due to jitter effects and imperfect beam position monitors (BPMs), indirectly cause emittance growth. Fast and accurate simulations of both the direct and indirect effects are desirable, but due to the many elements of the CLIC main linac, simulations may become very time consuming. In this paper, an efficient way of simulating linear (or nearly linear) dynamic effects is described. The method is also shown to facilitate the analytic determination of emittance growth caused by the different dynamic imperfections while using a trajectory feedback system. Emittance growth expressions are derived for quadrupole, accelerating structure, and beam jitter, for ground motion, and for noise in the feedback BPMs. Finally, it is shown how the method can be used to design a feedback system that is optimized for the optics of the machine and the ground motion spectrum of the particular site. This feedback system gives an emittance growth rate that is approximately 10 times lower than that of traditional trajectory feedbacks. The robustness of the optimized feedback system is studied for a number of additional imperfections, e.g., dipole corrector imperfections and faulty knowledge about the machine optics, with promising results.

Effect of hole imperfection on adiabatic film cooling effectiveness

International Nuclear Information System (INIS)

Jovanovic, M.B.; Lange, H.C.; Steenhoven, A.A. van

2008-01-01

The influence of a discrete imperfection on film cooling is studied by means of thermochromic liquid crystals measurements of the adiabatic film cooling effectiveness. As a benchmark, the effect of a jet ejected through a perfect hole is used. The film cooling effectiveness achieved with an imperfect hole is compared to the benchmark. A half torus plays the role of the discrete imperfection. The influence of the presence of the imperfection, its position and the turbulence intensity of the free stream are analyzed. The measurement data are depicted as two-dimensional plots but also as integral values. It is found that the imperfection, placed one diameter from the hole leading edge, deteriorates the effectiveness at moderate velocity ratios. Under the same conditions, the same imperfection fixed at the hole exit improves the effectiveness. At the velocity ratio of 1.50, the exit imperfection improves the integral effectiveness relatively for more than two times. The turbulence intensity and imperfections placed deeper in the hole do not have a significant influence

Puzzles of large scale structure and gravitation

International Nuclear Information System (INIS)

Sidharth, B.G.

2006-01-01

We consider the puzzle of cosmic voids bounded by two-dimensional structures of galactic clusters as also a puzzle pointed out by Weinberg: How can the mass of a typical elementary particle depend on a cosmic parameter like the Hubble constant? An answer to the first puzzle is proposed in terms of 'Scaled' Quantum Mechanical like behaviour which appears at large scales. The second puzzle can be answered by showing that the gravitational mass of an elementary particle has a Machian character (see Ahmed N. Cantorian small worked, Mach's principle and the universal mass network. Chaos, Solitons and Fractals 2004;21(4))

Modified economic order quantity (EOQ model for items with imperfect quality: Game-theoretical approaches

Directory of Open Access Journals (Sweden)

Milad Elyasi

2014-04-01

Full Text Available In the recent decade, studying the economic order quantity (EOQ models with imperfect quality has appealed to many researchers. Only few papers are published discussing EOQ models with imperfect items in a supply chain. In this paper, a two-echelon decentralized supply chain consisting of a manufacture and a supplier that both face just in time (JIT inventory problem is considered. It is sought to find the optimal number of the shipments and the quantity of each shipment in a way that minimizes the both manufacturer’s and the supplier’s cost functions. To the authors’ best knowledge, this is the first paper that deals with imperfect items in a decentralized supply chain. Thereby, three different game theoretical solution approaches consisting of two non-cooperative games and a cooperative game are proposed. Comparing the results of three different scenarios with those of the centralized model, the conclusions are drawn to obtain the best approach.

Sleep for Kids: Games and Puzzles

Science.gov (United States)

... and puzzles can help you learn more about sleep! Learn about sleep with this fun crossword puzzle! Test your memory and learn how to get better sleep! Find the hidden sleep words! Avoid things that ...

Phthalate Puzzle

Indian Academy of Sciences (India)

Abstract. The most common plasticizer, phthalates, are facing stricterregulations due to their omnipresence and possible effects onhuman health, and environment. But high cost, lack of applicationrange, and unknown long-term effects of non-phthalatealternatives make the scenario puzzling.

Musings on the puzzle piece.

Science.gov (United States)

Goin-Kochel, Robin P

2016-02-01

Following is a brief musing on Roy Grinker's discussion of what the puzzle piece symbolizes for autism during his presentation at the 2015 International Meeting for Autism Research. In his words, "The puzzle piece is ubiquitous." It likely holds a different meaning for each of us, and this is how one autism researcher sees it. © The Author(s) 2015.

Imaginary Cubes and Their Puzzles

Directory of Open Access Journals (Sweden)

Hideki Tsuiki

2012-05-01

Full Text Available Imaginary cubes are three dimensional objects which have square silhouette projections in three orthogonal ways just as a cube has. In this paper, we study imaginary cubes and present assembly puzzles based on them. We show that there are 16 equivalence classes of minimal convex imaginary cubes, among whose representatives are a hexagonal bipyramid imaginary cube and a triangular antiprism imaginary cube. Our main puzzle is to put three of the former and six of the latter pieces into a cube-box with an edge length of twice the size of the original cube. Solutions of this puzzle are based on remarkable properties of these two imaginary cubes, in particular, the possibility of tiling 3D Euclidean space.

Influence of hole imperfection on jet cross flow interaction

International Nuclear Information System (INIS)

Jovanovic, M.B.; Lange, H.C. de; Steenhoven, A.A. van

2006-01-01

The influence of a small hole geometry variation on the jet cross flow interaction is investigated experimentally using particle image velocimetry and liquid crystal thermography. The flow characteristics correspond to film cooling in gas turbines. A production imperfection is represented with the small variation of the hole geometry. The experiments were conducted without and with the hole imperfection at three velocity ratios. If the imperfection is absent, the flow field is stable and clockwise vortices are detected downstream. The imperfection blocks the hole, accelerates the jet and changes the formation of large vortical structures. It produces the additional windward vortices, which influence the flow field and enhance the inflow of the cross-stream towards the cooled surface. The imperfection reduces the film cooling effectiveness

Spanish Imperfect Revisited: Exploring L1 Influence in the Reassembly of Imperfective Features onto New L2 Forms

Science.gov (United States)

Domínguez, Laura; Arche, María J.; Myles, Florence

2017-01-01

This study investigates the acquisition of the Spanish Imperfect by 60 English learners of Spanish at three different proficiency levels (beginner, intermediate and advanced). Two oral production tasks and one interpretation task show that although the Imperfect is used from early on, the full array of interpretations associated with this form…

Hadronic decay puzzle in charmonium physics

International Nuclear Information System (INIS)

Gu Yifan

1996-01-01

Recent experimental results obtained at Beijing Electron-proton Collider sensitivity level the crisply defined nature of the hadronic decay puzzle in charmonium physics. Discovery of new anomalous decay modes breaks with the previously established pattern of the puzzle, and poses new challenges for its theoretical understanding

3D satellite puzzles for young and old kids

Science.gov (United States)

Biondi, Riccardo; Galoforo, Germana

2017-04-01

The Italian Space Agency (ASI) is active in outreach willing to increase the interest of young generations and general public toward the space activities. ASI proposes educational programmes for supporting and encouraging the development of European society based on knowledge, inspiring and motivating the young generations. One of the initiatives promoted by ASI on this regards is the 3D satellite puzzles. The idea was born in 2007 from the will to conceive an educational product for promoting and explaining to students the small all-Italian mission AGILE (Astrorivelatore Gamma ad Immagini ultra Leggero) thought as a tool for students aged 8-13. Working with this slot of students is very productive in terms of the imprints left on the kids, in fact it is useful to produce things they can use, touch and play with, with an active approach instead of a passive one. Therefore it was decided to produce something that kids could build and use at home with their parents or friends, or all together at school with teachers and mates. Other puzzles followed AGILE, one about the COSMO-SkyMED satellites about Earth Observation and also a broader one of the International Space Station. During these 10 years the puzzles were mostly used as outreach tools for school children, but they surprisingly received a great success also within older generations. So far the 3D puzzles have been printed in more than 10 thousand copies and distributed for free to students of hundreds of schools in Italy, and to the general public through science associations, planetaria and museums. Recently they have been used also during special events such as the international Geoscience Communication School (as best practice outreach tool), the EXPO 2015 and the European Researcheŕs Night at the Parlamentarium in Brussels 2016. While the students are building the puzzles, the tutor explains them the different components that they are assembling, what the importance of the satellite is and how it works

PSQP: Puzzle Solving by Quadratic Programming.

Science.gov (United States)

Andalo, Fernanda A; Taubin, Gabriel; Goldenstein, Siome

2017-02-01

In this article we present the first effective method based on global optimization for the reconstruction of image puzzles comprising rectangle pieces-Puzzle Solving by Quadratic Programming (PSQP). The proposed novel mathematical formulation reduces the problem to the maximization of a constrained quadratic function, which is solved via a gradient ascent approach. The proposed method is deterministic and can deal with arbitrary identical rectangular pieces. We provide experimental results showing its effectiveness when compared to state-of-the-art approaches. Although the method was developed to solve image puzzles, we also show how to apply it to the reconstruction of simulated strip-shredded documents, broadening its applicability.

A new periodic imperfect quasi axisymmetric shell element

International Nuclear Information System (INIS)

Combescure, A.; Garuti, G.

1983-08-01

The object of this paper is to give the formulation and the validation of a ''quasi axisymmetric'' shell element: the main idea is to develop the theory of an imperfect quasi axisymmetric shell element. The imperfection is a variation of the circumferential radius of curvature rsub(theta). The equations are obtained by transporting the equilibrium equations from the actual geometry onto the theoretical axisymmetric (rsub(theta)=r 0 geometry. It is shown that the main hypothesis convenient to perform simply this transformation is that the membrane strains associated with that variation of geometry are less than 1% (that is always the case if you suppose that the imperfect structure is obtained from the perfect one by an inextensional displacement field). The formulation of the element is given in the general case. The rigidity matrices, are given in the particular case in which the imperfection has a component on a single Fourier harmonic. The comparison of theoretical and computed, 3D and quasi axisymmetric, solution or a very simple case shows the influence of the number of the Fourier harmonics chosen on the response of the structure. The influence of the initial imperfections on the natural frequency are studied with element and compared with 3D calculations. Comparison of 3D, quasi axisymmetric, and analytical buckling loads are given and explained. This element gives a very efficient tool for the calculation of thin shells of revolution (which are always imperfect) and especially unables easy parametric study of the variation of the buckling load and eigen frequencies with the amplitude and shapes of non axisymmetric imperfections

Accounting for imperfect detection in ecology: a quantitative review.

Science.gov (United States)

Kellner, Kenneth F; Swihart, Robert K

2014-01-01

Detection in studies of species abundance and distribution is often imperfect. Assuming perfect detection introduces bias into estimation that can weaken inference upon which understanding and policy are based. Despite availability of numerous methods designed to address this assumption, many refereed papers in ecology fail to account for non-detection error. We conducted a quantitative literature review of 537 ecological articles to measure the degree to which studies of different taxa, at various scales, and over time have accounted for imperfect detection. Overall, just 23% of articles accounted for imperfect detection. The probability that an article incorporated imperfect detection increased with time and varied among taxa studied; studies of vertebrates were more likely to incorporate imperfect detection. Among articles that reported detection probability, 70% contained per-survey estimates of detection that were less than 0.5. For articles in which constancy of detection was tested, 86% reported significant variation. We hope that our findings prompt more ecologists to consider carefully the detection process when designing studies and analyzing results, especially for sub-disciplines where incorporation of imperfect detection in study design and analysis so far has been lacking.

The Magnets Puzzle is NP-Complete

DEFF Research Database (Denmark)

Kölker, Jonas

2012-01-01

In a Magnets puzzle, one must pack magnets in a box subjet to polarity and numeric constraints. We show that solvability of Magnets instances is NP-complete.......In a Magnets puzzle, one must pack magnets in a box subjet to polarity and numeric constraints. We show that solvability of Magnets instances is NP-complete....

Early puzzle play: a predictor of preschoolers' spatial transformation skill.

Science.gov (United States)

Levine, Susan C; Ratliff, Kristin R; Huttenlocher, Janellen; Cannon, Joanna

2012-03-01

Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examined the relation between children's early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 min every 4 months (6 times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2-dimensional shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than for girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not for boys. Implications of these findings as well as future directions for research on the role of puzzle play in the development of spatial skill are discussed. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Early Puzzle Play: A predictor of preschoolers’ spatial transformation skill

Science.gov (United States)

Levine, S.C.; Ratliff, K.R.; Huttenlocher, J.; Cannon, J.

2011-01-01

Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examines the relation between children’s early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 minutes every four months (six times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2D shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not boys. Implications of these findings as well as future directions for research on the role of the role of puzzle play in the development of spatial skill are discussed. PMID:22040312

Deductive Puzzling

Science.gov (United States)

Wanko, Jeffrey J.

2010-01-01

To help fifth- through eighth-grade students develop their deductive reasoning skills, the author used a ten-week supplementary curriculum so that students could answer logic questions. The curriculum, a series of lessons built around language-independent logic puzzles, has been used in classrooms of fifth through eighth grades. In most cases,…

Emissions trading under market imperfections

Energy Technology Data Exchange (ETDEWEB)

Lappi, P.

2013-08-15

In this thesis we consider emissions trading under various market imperfections such as uncertainty over permit price, imperfect competition and noncompliance. First, we study the effects of uncertain permit price on the firms choice of emission intensive and clean inputs in an multi-input production process. We also assess the risk aversion factors of some Finnish heat and power producers. Second, we study imperfect competition in output and permit markets with a two-stage model, where output decision is made before permit trades. The emphasis is on the strategic interaction between firms and on the efficiency increasing regulation. Third, we turn back to uncertainty and analyse the welfare difference between emissions trading and emission tax, when some of the firms may be noncompliant. The main finding is that welfare is greater with emission tax than with emissions trading, when at least one firm is noncompliant. Finally, we extend some existing models of permit banking and borrowing to encompass also noncompliant behavior of firms. Here, we analyse the incentives of compliant firms to become noncompliant at some point in time and also the time paths of the choice variables. (orig.)

Firms’ behavior in conditions of imperfect competitive environments

Directory of Open Access Journals (Sweden)

Ján Kantor

2007-12-01

Full Text Available This article deals with the analysis of market structure on the imperfect competitive market, measuring market power, its effect on the price of products and reasons for origin of imperfect competition at the market. Described are the market conditions issues and possibilities of their manufacturing influence on the market price with graphical expressions. Prices are higher and capacity of production is lower. It characterizes monopoly, oligopoly, and monopolistic competition. With its content it expresses, that imperfect competitive environment differs from perfect competition environment disparity of demand curve and in the market economics it has a more frequent application.

Puzzle Pedagogy: A Use of Riddles in Mathematics Education

Science.gov (United States)

Farnell, Elin

2017-01-01

In this article, I present a collection of puzzles appropriate for use in a variety of undergraduate courses, along with suggestions for relevant discussion. Logic puzzles and riddles have long been sources of amusement for mathematicians and the general public alike. I describe the use of puzzles in a classroom setting, and argue for their use as…

Methodological imperfection and formalizations in scientific activity

International Nuclear Information System (INIS)

Svetlichny, G.

1987-01-01

Any mathematical formalization of scientific activity allows for imperfections in the methodology that is formalized. These can be of three types, dirty, rotten, and dammed. Restricting mathematical attention to those methods that cannot be construed to be imperfect drastically reduces the class of objects that must be analyzed, and related all other objects to these more regular ones. Examples are drawn from empirical logic

Famous puzzles of great mathematicians

CERN Document Server

Petković, Miodrag S

2009-01-01

This entertaining book presents a collection of 180 famous mathematical puzzles and intriguing elementary problems that great mathematicians have posed, discussed, and/or solved. The selected problems do not require advanced mathematics, making this book accessible to a variety of readers. Mathematical recreations offer a rich playground for both amateur and professional mathematicians. Believing that creative stimuli and aesthetic considerations are closely related, great mathematicians from ancient times to the present have always taken an interest in puzzles and diversions. The goal of this

The Economics of Imperfect Labor Markets : Second Edition

NARCIS (Netherlands)

Boeri, T.; van Ours, J.C.

2013-01-01

Most labor economics textbooks pay little attention to actual labor markets, taking as reference a perfectly competitive market in which losing a job is not a big deal.The Economics of Imperfect Labor Markets is the only textbook to focus on imperfect labor markets and to provide a systematic

Nonlinear analysis of wiggler-imperfections in free-electron lasers

Energy Technology Data Exchange (ETDEWEB)

Freund, H.P. [Naval Research Lab., Washington, DC (United States); Yu, L.H. [Brookhaven National Lab., Upton, NY (United States)

1995-12-31

We present an analysis of the effect of wiggler imperfections in FELs using a variety of techniques. Our basic intention is to compare wiggler averaged nonlinear simulations to determine the effect of various approximations on the estimates of gain degradation due to wiggler imperfections. The fundamental assumption in the wiggler-averaged formulations is that the electrons are described by a random walk model, and an analytic representation of the orbits is made. This is fundamentally different from the approach taken for the non-wiggler-averaged formulation in which the wiggler imperfections are specified at the outset, and the orbits are integrated using a field model that is consistent with the Maxwell equations. It has been conjectured on the basis of prior studies using the non-wiggler-averaged formalism that electrons follow a {open_quotes}meander line{close_quotes} through the wiggler governed by the specific imperfections; hence, the electrons behave more as a ball-in-groove than as a random walk. This conjecture is tested by comparison of the wiggler-averaged and non-wiggler-averaged simulations. In addition, two different wiggler models are employed in the non-wiggler-averaged simulation: one based upon a parabolic pole face wiggler which is not curl and divergence free in the presence of wiggler imperfections, and a second model in which the divergence and z-component of the curl vanish identically. This will gauge the effect of inconsistencies in the wiggler model on the estimation of the effect of the imperfections. Preliminary results indicate that the inconsistency introduced by the non-vanishing curl and divergence result in an overestimation of the effect of wiggler imperfections on the orbit. The wiggler-averaged simulation is based upon the TDA code, and the non-wiggler-averaged simulation is a variant of the ARACHNE and WIGGLIN codes called MEDUSA developed to treat short-wavelength Gauss-Hermite modes.

CROSSWORD PUZZLE INCREASE ATTENTION OF CHILDREN WITH ADHD

Directory of Open Access Journals (Sweden)

Ah. Yusuf

2017-07-01

Full Text Available Introduction: Attention deficit is one of three main problems of children with Attention Deficit Hyperactivity Disorder (ADHD. Children experience difficulty of paying attention and concentrating to one or more things or objects. As a results these children cannot perform the task well. Crossword puzzle is one of games that may increase attention and concentration. The aim of this study was to analyze the effect of crossword puzzle to increase attention of children with ADHD. Method: Pre-experimental design was employed in this study. The population was ADHD students in Cakra Autisme Therapy. Seven students were recruited by means of purposive sampling. The independent variable was crossword puzzle and the dependent variable was the increase of attention. Data were collected using observation sheet and analyzed using Wilcoxon Signed Rank Test with level of significance of α≤ 0.05. Result: Result showed that crossword puzzle could increase attention. Respondent’s attention improved from less to good attention, particularly in playing activities (p=0.014. Analysis: This finding suggests that there was differences of attention between pre and post-test. It can be concluded that crossword puzzle can increase attention of the students with ADHD. Discussion: It is recommended for teachers and parents of ADHD children to give them crossword puzzle game everyday at school or at home. Further studies should involve larger sample size and employs another game not only to increase attention, but also reduce hyperactivity and impulsivity of ADHD child.

Evaluation of the three-nucleon analyzing power puzzle

International Nuclear Information System (INIS)

Tornow, W.; Witala, H.

1998-01-01

The current status of the three-nucleon analyzing power puzzle is reviewed. Applying tight constraints on the allowed deviations between calculated predictions and accepted values for relevant nucleon-nucleon observables reveals that energy independent correction factors applied to the 3 P j nucleon-nucleon interactions can not solve the puzzle. Furthermore, using the same constraints, charge-independence breaking in the 3 P j nucleon-nucleon interactions can be ruled out as a possible tool to improve the agreement between three-nucleon calculations and data. The study of the energy dependence of the three-nucleon analyzing power puzzle gives clear evidence that the 3 P j nucleon-nucleon interaction obtained from phase-shift analyses and used in potential models are correct above about 25 MeV, i.e., the 3 P j nucleon-nucleon interactions have to be modified only at lower energies in order to solve the three-nucleon analyzing power puzzle, unless new three-nucleon forces can be found that account for the three-nucleon analyzing power puzzle without destroying the beautiful agreement between rigorous three-nucleon calculations and a large body of accurate three-nucleon data. (orig.)

Evaluation of the three-nucleon analyzing power puzzle

Energy Technology Data Exchange (ETDEWEB)

Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics]|[Triangle Univ. Nuclear Lab., Durham, NC (United States); Witala, H. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki

1998-07-20

The current status of the three-nucleon analyzing power puzzle is reviewed. Applying tight constraints on the allowed deviations between calculated predictions and accepted values for relevant nucleon-nucleon observables reveals that energy independent correction factors applied to the {sup 3}P{sub j} nucleon-nucleon interactions can not solve the puzzle. Furthermore, using the same constraints, charge-independence breaking in the {sup 3}P{sub j} nucleon-nucleon interactions can be ruled out as a possible tool to improve the agreement between three-nucleon calculations and data. The study of the energy dependence of the three-nucleon analyzing power puzzle gives clear evidence that the {sup 3}P{sub j} nucleon-nucleon interaction obtained from phase-shift analyses and used in potential models are correct above about 25 MeV, i.e., the {sup 3}P{sub j} nucleon-nucleon interactions have to be modified only at lower energies in order to solve the three-nucleon analyzing power puzzle, unless new three-nucleon forces can be found that account for the three-nucleon analyzing power puzzle without destroying the beautiful agreement between rigorous three-nucleon calculations and a large body of accurate three-nucleon data. (orig.) 18 refs.

Optimum policies for a system with general imperfect maintenance

International Nuclear Information System (INIS)

Sheu, S.-H.; Lin, Y.-B.; Liao, G.-L.

2006-01-01

This study considers periodic preventive maintenance policies, which maximizes the availability of a repairable system with major repair at failure. Three types of preventive maintenance are performed, namely: imperfect preventive maintenance (IPM), perfect preventive maintenance (PPM) and failed preventive maintenance (FPM). The probability that preventive maintenance is perfect depends on the number of imperfect maintenances conducted since the previous renewal cycle, and the probability that preventive maintenance remains imperfect is not increasing. The optimum preventive maintenance time that maximizes availability is derived. Various special cases are considered. A numerical example is given

Algorithmic Puzzles: History, Taxonomies, and Applications in Human Problem Solving

Science.gov (United States)

Levitin, Anany

2017-01-01

The paper concerns an important but underappreciated genre of algorithmic puzzles, explaining what these puzzles are, reviewing milestones in their long history, and giving two different ways to classify them. Also covered are major applications of algorithmic puzzles in cognitive science research, with an emphasis on insight problem solving, and…

Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

International Nuclear Information System (INIS)

Sanchez, Ana; Carlos, Sofia; Martorell, Sebastian; Villanueva, Jose F.

2009-01-01

Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral

Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Ana [Department of Statistics and Operational Research, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Carlos, Sofia [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Martorell, Sebastian [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)], E-mail: smartore@iqn.upv.es; Villanueva, Jose F. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)

2009-01-15

Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral.

Idiosyncratic Volatility Puzzle

DEFF Research Database (Denmark)

Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos

from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong...

Teaching the Blue-Eyed Islanders Puzzle in a Liberal Arts Mathematics Course

Science.gov (United States)

Shea, Stephen

2012-01-01

The blue-eyed islanders puzzle is an old and challenging logic puzzle. This is a narrative of an experience introducing a variation of this puzzle on the first day of classes in a liberal arts mathematics course for non-majors. I describe an exercise that was used to facilitate the class's understanding of the puzzle.

Sampling Random Bioinformatics Puzzles using Adaptive Probability Distributions

DEFF Research Database (Denmark)

Have, Christian Theil; Appel, Emil Vincent; Bork-Jensen, Jette

2016-01-01

We present a probabilistic logic program to generate an educational puzzle that introduces the basic principles of next generation sequencing, gene finding and the translation of genes to proteins following the central dogma in biology. In the puzzle, a secret "protein word" must be found by asse...

Benefits of the S/F cask impact limiter weldment imperfection

International Nuclear Information System (INIS)

Ku, Jeong Hoe; Lee, Ju Chan; Kim, Jong Hun; Park, Seong Won; Park, Hyun Soo

2000-01-01

This paper describes the beneficial effect of weldment imperfection of the cask impact limiter, by applying intermittent-weld, for impact energy absorbing behavior. From the point of view of energy absorbing efficiency of an energy absorber, it is desirable to reduce the crush load resistance and increase the deformation of the energy absorber within certain limit. This paper presents the test results of intermittent-weldment and the analysis results of cask impacts and the discussions of the improvement of impact mitigating effect by the imperfect-weldment. The rupture of imperfect weldment of an impact limiter improves the energy-absorbing efficiency by reducing the crush load amplitude without loss of total energy absorption. The beneficial effect of weldment imperfection should be considered to the cask impact limiter design. (author)

Performance of Pre-processing Schemes with Imperfect Channel State Information

DEFF Research Database (Denmark)

Christensen, Søren Skovgaard; Kyritsi, Persa; De Carvalho, Elisabeth

2006-01-01

Pre-processing techniques have several benefits when the CSI is perfect. In this work we investigate three linear pre-processing filters, assuming imperfect CSI caused by noise degradation and channel temporal variation. Results indicate, that the LMMSE filter achieves the lowest BER and the high......Pre-processing techniques have several benefits when the CSI is perfect. In this work we investigate three linear pre-processing filters, assuming imperfect CSI caused by noise degradation and channel temporal variation. Results indicate, that the LMMSE filter achieves the lowest BER...... and the highest SINR when the CSI is perfect, whereas the simple matched filter may be a good choice when the CSI is imperfect. Additionally the results give insight into the inherent trade-off between robustness against CSI imperfections and spatial focusing ability....

Characterization of a multilayer Laue lens with imperfections

International Nuclear Information System (INIS)

Yan, H.; Kang, H.C.; Maser, J.; Macrander, A.T.; Kewish, C.M.; Liu, C.; Conley, R.; Stephenson, G.B.

2007-01-01

We present a simulation result of the focusing performance of a multilayer Laue lens (MLL) with imperfections. Imperfections we have studied correspond to deviations of sequence of layers in the fabricated structure from the zone plate law. The actual sequence of layers of the MLL is measured by scanning electron microscope (SEM), and fitted by second order polynomials. X-ray characterization of the MLL structures is performed using coherent X-rays at the Advanced Photon Source. We observe very good agreement between experiment and simulation. This demonstrates that our simulation method can serve as an efficient tool to characterize the focusing performance of MLLs with imperfections, and thereby allows us to provide feedback following deposition and fabrication of the MLL structures and optimization of focusing structures prior to X-ray characterization

Incomplete Puzzle

Science.gov (United States)

2006-01-01

15 April 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of a portion of the south polar residual cap of Mars. The large, relatively flat-lying, puzzle-like pieces in this scene are mesas composed largely of solid carbon dioxide. Location near: 85.5oS, 76.8oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

The diagnostic significance of clinical and radiological findings in osteogenesis imperfection

International Nuclear Information System (INIS)

Xu Deyong; Xu Zushan; Shen Qijie

1997-01-01

Purpose: To define the diagnostic criteria of osteogenesis imperfection. Materials and methods: The clinical and radiologic manifestations of 68 patients with osteogenesis imperfection were studied retrospectively. Results: (1) A generalized decrease in osseous density (osteoporosis or osteopenia) with abnormal fragility of bone (68 cases). (2) Blue sclera (61 cases). (3) Dentinogenesis imperfection with opalescent bluish-gray tint (49 cases). (4) Progressive hearing loss (prior to the age of 40 years)-premature otosclerosis (38 cases). Other abnormalities such as abnormal contour and structure (68 cases), growth retardation (49 cases), episodic diaphoresis (24 cases), with abnormal temperature regulation (16 cases), hyperplastic scars (11 cases) and tendency of subcutaneous bruise (6 cases), all these were not characteristic features. Conclusion: Among all clinical and radiological findings, osteopenia with abnormal fragility of bone; blue sclera dentinogenesis imperfection with opalescent bluish-gray tint and premature otosclerosis are the most common and characteristic findings which can be taken as the diagnostic criteria of osteogenesis imperfection

Three Modes of Hydrogeophysical Investigation: Puzzles, Mysteries, and Conundrums

Science.gov (United States)

Ferre, P. A.

2011-12-01

In an article in the New Yorker in 2007, Malcolm Gladwell discussed the distinction that national security expert Gregory Treverton has made between puzzles and mysteries. Specifically, puzzles are problems that we understand and that will eventually be solved when we amass enough information. (Think crossword puzzles.) Mysteries are problems for which we have the necessary information, but it is often overwhelmed by irrelevant or misleading input. To solve a mystery, we require improved analysis. (Think find-a-word.) Gladwell goes on to explain that, in the national security realm, the Cold War was a puzzle while the current national security condition is a mystery. I will discuss the past, current, and future trajectories of hydrogeophysics in terms of puzzles and mysteries. I will also add a third class of problem: conundrums - those for which we lack sufficient information about their structure to know how to solve them. A conundrum is a mystery with an unexpected twist. I hope to make the case that the future growth of hydrogeophysics lies in our ability to address this more challenging and more interesting class of problem.

A Puzzle Used to Teach the Cardiac Cycle

Science.gov (United States)

Marcondes, Fernanda K.; Moura, Maria J. C. S.; Sanches, Andrea; Costa, Rafaela; Oliveira de Lima, Patricia; Groppo, Francisco Carlos; Amaral, Maria E. C.; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H.

2015-01-01

The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided…

The B→πK puzzle and supersymmetry

International Nuclear Information System (INIS)

Imbeault, Maxime; Baek, Seungwon; London, David

2008-01-01

At present, there are discrepancies between the measurements of several observables in B→πK decays and the predictions of the Standard Model (the 'B→πK puzzle'). Although the effect is not yet statistically significant-it is at the level of ≥3σ-it does hint at the presence of new physics. In this Letter, we explore whether supersymmetry (SUSY) can explain the B→πK puzzle. In particular, we consider the SUSY model of Grossman, Neubert and Kagan (GNK). We find that it is extremely unlikely that GNK explains the B→πK data. We also find a similar conclusion in many other models of SUSY. And there are serious criticisms of the two SUSY models that do reproduce the B→πK data. If the B→πK puzzle remains, it could pose a problem for SUSY models

A proactive condition-based maintenance strategy with both perfect and imperfect maintenance actions

International Nuclear Information System (INIS)

Do, Phuc; Voisin, Alexandre; Levrat, Eric; Iung, Benoit

2015-01-01

This paper deals with a proactive condition-based maintenance (CBM) considering both perfect and imperfect maintenance actions for a deteriorating system. Perfect maintenance actions restore completely the system to the ‘as good as new’ state. Their related cost are however often high. The first objective of the paper is to investigate the impacts of imperfect maintenance actions. In fact, both positive and negative impacts are considered. Positive impact means that the imperfect maintenance cost is usually low. Negative impact implies that (i) the imperfect maintenance restores a system to a state between good-as-new and bad-as-old and (ii) each imperfect preventive action may accelerate the speed of the system's deterioration process. The second objective of the paper is to propose an adaptive maintenance policy which can help to select optimally maintenance actions (perfect or imperfect actions), if needed, at each inspection time. Moreover, the time interval between two successive inspection points is determined according to a remaining useful life (RUL) based-inspection policy. To illustrate the use of the proposed maintenance policy, a numerical example finally is introduced. - Highlights: • A new imperfect maintenance model for deterioration system is proposed. • Both positive and negative impacts of an imperfect maintenance action are investigated. • An adaptive condition-based maintenance policy is introduced. • The optimal number of useful imperfect maintenance actions for each life cycle is optimally provided

The Entrepreneurial Earnings Puzzle

DEFF Research Database (Denmark)

Chen, Jing; Åstebro, Thomas

2014-01-01

A review of recent evidence on relative earnings from entrepreneurship versus wage work presents a puzzle: why do individuals become entrepreneurs when entrepreneurs on average apparently earn less than employees? After considering several potential explanations, we empirically analyze one: income...

Decoding Codewords: Statistical Analysis of a Newspaper Puzzle

Science.gov (United States)

Meacock, Susan; Meacock, Geoff

2012-01-01

In recent years English newspapers have started featuring a number of puzzles other than the ubiquitous crossword. Many of the puzzles are of Japanese origin such as Sudoku, Kakuro or Hidato. However, one recent one is very English and is called variously Cross-code, Alphapuzzle or some other name. In this article, it will be known as Codeword.…

The individual life-cycle, annuity market imperfections and economic growth

NARCIS (Netherlands)

Heijdra, Ben J.; Mierau, Jochen O.

We study the effects of an annuity market imperfection on individual agents' life-cycle decisions and on the macroeconomic growth rate in an overlapping generations model with single-sector endogenous growth. Our model features both age-dependent mortality and labour productivity. We model imperfect

Endogenous, Imperfectly Competitive Business Cycles

DEFF Research Database (Denmark)

Whitta-Jacobsen, Hans Jørgen

We investigate how imperfect competition affects the occurrence and the properties of endogenous, rational expectations business cycles in an overlapping generations model with constant returns to scale in production. The model has explicit product and labor markets all characterized...... by monopolistic competition. An implicit assumption of barriers to entry justifies that the number of firms is fixed even when positive profits occur. It turns out that both market power of firms on the product markets and market power of unions on the labor markets make the occurrence of cycles more likely....... In particular, imperfect competition on the product markets and the positive profits associated with it may have the effect that there is a cycle even if the labor supply curve is increasing in the real-wage rate. For competitive cycles is required not only a decreasing labor supply curve, but a wage elasticity...

Current puzzles and future possibilities

International Nuclear Information System (INIS)

Nagamiya, S.

1982-02-01

Four current puzzles and several future experimental possibilities in high-energy nuclear collision research are discussed. These puzzles are (1) entropy, (2) hydrodynamic flow, (3) anomalon, and (4) particle emission at backward angles in proton-nucleus collisions. The last one seems not to be directly related to the subject of the present school. But it is, because particle emission into the region far beyond the nucleon-nucleon kinematical limit is an interesting subject common for both proton-nucleus and nucleus-nucleus collisions, and the basic mechanism involved is strongly related in these two cases. Future experimental possibilities are described which include: (1) possibilities of studying multibaryonic excited states, (2) applications of neutron-rich isotopes, and (3) other needed experimental tasks. 72 references

The Imperfect Unbound : A Cognitive Linguistic Approach to Greek Aspect

NARCIS (Netherlands)

Allan, R.J.; Bentein, Klaas; Janse, Mark; Soltic, Jorie

2017-01-01

In Ancient Greek narrative, the imperfect typically presents the state of affairs as ongoing in order to serve as a temporal framework for the occurrence of one or more other states of affairs. However, in narrative we also find a considerable number of imperfects (especially with verbs of motion

Crossword Puzzles as Learning Tools in Introductory Soil Science

Science.gov (United States)

Barbarick, K. A.

2010-01-01

Students in introductory courses generally respond favorably to novel approaches to learning. To this end, I developed and used three crossword puzzles in spring and fall 2009 semesters in Introductory Soil Science Laboratory at Colorado State University. The first hypothesis was that crossword puzzles would improve introductory soil science…

Failure in imperfect anisotropic materials

DEFF Research Database (Denmark)

Legarth, Brian Nyvang

2005-01-01

The fundamental cause of crack growth, namely nucleation and growth of voids, is investigated numerically for a two phase imperfect anisotropic material. A unit cell approach is adopted from which the overall stress strain is evaluated. Failure is observed as a sudden stress drop and depending...

Optical identification using imperfections in 2D materials

Science.gov (United States)

Cao, Yameng; Robson, Alexander J.; Alharbi, Abdullah; Roberts, Jonathan; Woodhead, Christopher S.; Noori, Yasir J.; Bernardo-Gavito, Ramón; Shahrjerdi, Davood; Roedig, Utz; Fal'ko, Vladimir I.; Young, Robert J.

2017-12-01

The ability to uniquely identify an object or device is important for authentication. Imperfections, locked into structures during fabrication, can be used to provide a fingerprint that is challenging to reproduce. In this paper, we propose a simple optical technique to read unique information from nanometer-scale defects in 2D materials. Imperfections created during crystal growth or fabrication lead to spatial variations in the bandgap of 2D materials that can be characterized through photoluminescence measurements. We show a simple setup involving an angle-adjustable transmission filter, simple optics and a CCD camera can capture spatially-dependent photoluminescence to produce complex maps of unique information from 2D monolayers. Atomic force microscopy is used to verify the origin of the optical signature measured, demonstrating that it results from nanometer-scale imperfections. This solution to optical identification with 2D materials could be employed as a robust security measure to prevent counterfeiting.

Teaching Proofs and Algorithms in Discrete Mathematics with Online Visual Logic Puzzles

Science.gov (United States)

Cigas, John; Hsin, Wen-Jung

2005-01-01

Visual logic puzzles provide a fertile environment for teaching multiple topics in discrete mathematics. Many puzzles can be solved by the repeated application of a small, finite set of strategies. Explicitly reasoning from a strategy to a new puzzle state illustrates theorems, proofs, and logic principles. These provide valuable, concrete…

Market imperfections on the power markets in northern Europe: A survey paper

DEFF Research Database (Denmark)

Skytte, K.

1999-01-01

Up till now, most analyses of the northern European electricity liberalisation have assumed that a perfect competitive electricity market can be obtained. It has not been taken into account that a number of imperfections will inevitably occur - at least during the transition period. These imperfe...... not be achieved. The aim of this paper is to survey market imperfections and their influence on the liberalisation processes in northern Europe......Up till now, most analyses of the northern European electricity liberalisation have assumed that a perfect competitive electricity market can be obtained. It has not been taken into account that a number of imperfections will inevitably occur - at least during the transition period....... These imperfections can be technical, economic or tradition-bound, and can also have political characteristics. It is important to recognise and incorporate the market imperfections in the liberalisation policy and analysis. Otherwise, the purposes of the liberalisation and other energy policy goals may...

Selection of security system design via games of imperfect information and multi-objective genetic algorithm

International Nuclear Information System (INIS)

Lins, Isis Didier; Rêgo, Leandro Chaves; Moura, Márcio das Chagas

2013-01-01

This work analyzes the strategic interaction between a defender and an intelligent attacker by means of a game and reliability framework involving a multi-objective approach and imperfect information so as to support decision-makers in choosing efficiently designed security systems. A multi-objective genetic algorithm is used to determine the optimal security system's configurations representing the tradeoff between the probability of a successful defense and the acquisition and operational costs. Games with imperfect information are considered, in which the attacker has limited knowledge about the actual security system. The types of security alternatives are readily observable, but the number of redundancies actually implemented in each security subsystem is not known. The proposed methodology is applied to an illustrative example considering power transmission lines in the Northeast of Brazil, which are often targets for attackers who aims at selling the aluminum conductors. The empirical results show that the framework succeeds in handling this sort of strategic interaction. -- Highlights: ► Security components must have feasible costs and must be reliable. ► The optimal design of security systems considers a multi-objective approach. ► Games of imperfect information enable the choice of non-dominated configurations. ► MOGA, reliability and games support the entire defender's decision process. ► The selection of effective security systems may discourage attacker's actions

Statistical inference from imperfect photon detection

International Nuclear Information System (INIS)

Audenaert, Koenraad M R; Scheel, Stefan

2009-01-01

We consider the statistical properties of photon detection with imperfect detectors that exhibit dark counts and less than unit efficiency, in the context of tomographic reconstruction. In this context, the detectors are used to implement certain positive operator-valued measures (POVMs) that would allow us to reconstruct the quantum state or quantum process under consideration. Here we look at the intermediate step of inferring outcome probabilities from measured outcome frequencies, and show how this inference can be performed in a statistically sound way in the presence of detector imperfections. Merging outcome probabilities for different sets of POVMs into a consistent quantum state picture has been treated elsewhere (Audenaert and Scheel 2009 New J. Phys. 11 023028). Single-photon pulsed measurements as well as continuous wave measurements are covered.

Pull-in instability tuning in imperfect nonlinear circular microplates under electrostatic actuation

Energy Technology Data Exchange (ETDEWEB)

Jallouli, A.; Kacem, N., E-mail: najib.kacem@univ-fcomte.fr; Bourbon, G.; Le Moal, P.; Walter, V.; Lardies, J.

2016-12-01

Highlights: • Dynamic range improvement of electrostatically actuated circular microplates. • Pull-in instability tuning based on geometric nonlinearity and imperfections. • Predictive computational model for the nonlinear behavior of circular microplates. - Abstract: Dynamic range improvement based on geometric nonlinearity and initial deflection is demonstrated with imperfect circular microplates under electrostatic actuation. Depending on design parameters, we prove how the von Kármán nonlinearity and the plate imperfections lead to a significant delay in pull-in occurrence. These promising results open the way towards an accurate identification of static parameters of circular microplates and the development of a predictive model for the nonlinear dynamics of imperfect capacitive micromachined ultrasonic transducers.

Puzzles in B physics

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 67; Issue 5. Puzzles in physics. Hsiang-Nan Li ... Author Affiliations. Hsiang-Nan Li1 2. Institute of Physics, Academia Sinica, Taipei, Taiwan 115, Republic of China; Department of Physics, National Cheng-Kung University, Tainan, Taiwan 701, Republic of China ...

La Francophonie. Puzzle Corner.

Science.gov (United States)

Andrews, Ian A.

2000-01-01

Discusses the organization La Francophonie, which is an international community of people who speak French and convene to address issues. Presents a crossword puzzle that introduces readers to some of the nations involved in La Francophonie. Provides the across and down clues, a word list, and answer key. (CMK)

Rotation capacity of imperfect gable frames commonly used in nuclear reactors

International Nuclear Information System (INIS)

Ahmed, K.M.F.

1998-01-01

As for real structures, initial geometric imperfections are inevitable and may have a destabilizing effect on the structures. The present research deals with the study of the imperfections and their direct influence on the load carrying capacity of various types of tapered steel frames. as such an efficient and realistic analytical model capable of dealing with non-linear behavior of steel frames with imperfections is introduced. The model is formulated within the framework of the finite element displacement approach. The frame elements are modeled through use of the conventional beam - column

Puzzling through General Chemistry: A Light-Hearted Approach to Engaging Students with Chemistry Content

Science.gov (United States)

Boyd, Susan L.

2007-01-01

Several puzzles are designed to be used by chemistry students as learning tools and teach them basic chemical concepts. The topics of the puzzles are based on the chapters from Chemistry, The Central Science used in general chemistry course and the puzzles are in various forms like crosswords, word searches, number searches, puzzles based on…

The Clock Is Ticking: Library Orientation as Puzzle Room

Science.gov (United States)

Reade, Tripp

2017-01-01

Tripp Reade is the school librarian at Cardinal Gibbons High School in Raleigh, North Carolina. This article describes how he redesigned his school's library orientation program after learning about escape rooms and a variant known as puzzle rooms. Puzzle rooms present players with a set of challenges to solve; they require "teamwork,…

Imperfect Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Mirzagholi, Leila; Vikman, Alexander, E-mail: l.mirzagholi@physik.uni-muenchen.de, E-mail: alexander.vikman@lmu.de [Arnold Sommerfeld Center for Theoretical Physics, Ludwig Maximilian University Munich, Theresienstr. 37, Munich, D-80333 Germany (Germany)

2015-06-01

We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

Imperfect Dark Matter

International Nuclear Information System (INIS)

Mirzagholi, Leila; Vikman, Alexander

2015-01-01

We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models

Imperfect Dark Matter

Science.gov (United States)

Mirzagholi, Leila; Vikman, Alexander

2015-06-01

We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

How to price imperfect certification

Czech Academy of Sciences Publication Activity Database

Mysliveček, Jan

-, č. 364 (2008), s. 1-37 ISSN 1211-3298 R&D Projects: GA MŠk LC542 Grant - others:Univerzita Karlova(CZ) 7743/2007 Institutional research plan: CEZ:AV0Z70850503 Keywords : certification * imperfect testing * competition Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp364.pdf

Puzzle-Based Learning in Engineering Mathematics: Students' Attitudes

Science.gov (United States)

Klymchuk, Sergiy

2017-01-01

The article reports on the results of two case studies on the impact of the regular use of puzzles as a pedagogical strategy in the teaching and learning of engineering mathematics. The intention of using puzzles is to engage students' emotions, creativity and curiosity and also to enhance their generic thinking skills and lateral thinking…

On IBM's Millennial Puzzle

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 10. On IBM's Millennial Puzzle. A Sarangarajan. Classroom Volume 5 Issue 10 October 2000 pp 81-89. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/005/10/0081-0089. Author Affiliations.

Robust Sex Differences in Jigsaw Puzzle Solving-Are Boys Really Better in Most Visuospatial Tasks?

Science.gov (United States)

Kocijan, Vid; Horvat, Marina; Majdic, Gregor

2017-01-01

Sex differences are consistently reported in different visuospatial tasks with men usually performing better in mental rotation tests while women are better on tests for memory of object locations. In the present study, we investigated sex differences in solving jigsaw puzzles in children. In total 22 boys and 24 girls were tested using custom build tablet application representing a jigsaw puzzle consisting of 25 pieces and featuring three different pictures. Girls outperformed boys in solving jigsaw puzzles regardless of the picture. Girls were faster than boys in solving the puzzle, made less incorrect moves with the pieces of the puzzle, and spent less time moving the pieces around the tablet. It appears that the strategy of solving the jigsaw puzzle was the main factor affecting differences in success, as girls tend to solve the puzzle more systematically while boys performed more trial and error attempts, thus having more incorrect moves with the puzzle pieces. Results of this study suggest a very robust sex difference in solving the jigsaw puzzle with girls outperforming boys by a large margin.

Robust Sex Differences in Jigsaw Puzzle Solving—Are Boys Really Better in Most Visuospatial Tasks?

Science.gov (United States)

Kocijan, Vid; Horvat, Marina; Majdic, Gregor

2017-01-01

Sex differences are consistently reported in different visuospatial tasks with men usually performing better in mental rotation tests while women are better on tests for memory of object locations. In the present study, we investigated sex differences in solving jigsaw puzzles in children. In total 22 boys and 24 girls were tested using custom build tablet application representing a jigsaw puzzle consisting of 25 pieces and featuring three different pictures. Girls outperformed boys in solving jigsaw puzzles regardless of the picture. Girls were faster than boys in solving the puzzle, made less incorrect moves with the pieces of the puzzle, and spent less time moving the pieces around the tablet. It appears that the strategy of solving the jigsaw puzzle was the main factor affecting differences in success, as girls tend to solve the puzzle more systematically while boys performed more trial and error attempts, thus having more incorrect moves with the puzzle pieces. Results of this study suggest a very robust sex difference in solving the jigsaw puzzle with girls outperforming boys by a large margin. PMID:29109682

Dynamic Response of Three-Layered Annular Plate with Imperfections

Directory of Open Access Journals (Sweden)

Pawlus Dorota

2015-02-01

Full Text Available This paper presents the imperfection sensitivity of annular plate with three-layered structure. The plate composed of thin elastic facings and a thicker elastic core is loaded in facing plane. The classical issue of a three-layered plate was solved for dynamic deflection problem using the approximation methods: orthogonalization and finite difference. The solution includes the axisymmetric and asymmetric plate modes of the dynamic stability loss. The evaluation of the rate of plate sensitivity to imperfection of plate preliminary geometry has been enriched by the analysis of plate models built of finite elements. The ABAQUS program has been used. The numerous calculation results in the form of deflection characteristics, buckling modes, values of critical parameters create the view of response of dynamic plate structure with different rate of imperfection and linear in time loading growth, too.

MHD pressure drop in ducts with imperfectly insulating coatings

International Nuclear Information System (INIS)

Malang, S.; Buehler, L.

1994-08-01

Liquid metal cooled blankets in fusion tokamak's are feasible only with electrically insulating coatings at the coolant channel walls. The requirements of such coatings are investigated and a simple analytical model is developed to determine the influence of imperfections in the coatings on the magneto-hydrodynamic pressure drop. This model is compared with the results of a 3D-MHD code based on the core flow approach. Both methods are in good agreement as long as the imperfections do not increase the pressure drop by more than 20%. The analytical model over-estimates the pressure drop for values larger than 20%. The importance of self-healing of coatings in case of cracking or flaking is quantified and an equation for the equilibrium conditions between the generation of imperfection and the healing of such spots is provided

Lepton mixing and the ''solar neutrino puzzle''

International Nuclear Information System (INIS)

Bilenky, S.M.; Pontecorvo, B.

1977-01-01

The results of the well known solar neutrino experiment of Davis et al. are discussed, in which the Cl-Ar method is used. The result of the experiment, a too small neutrino signal (the so-called ''solar neutrino puzzle'), has been tentatively accounted for in a number of quite exotic explanations. It appears that the explanation in terms of lepton mixing and neutrino sterility is quite attractive from the point of view of present day elementary particle physics and is much more natural than the other explanations of the ''puzzle''

International trade network: fractal properties and globalization puzzle.

Science.gov (United States)

Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

2014-12-12

Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade.

Distress risk and leverage puzzles: Evidence from Taiwan

Directory of Open Access Journals (Sweden)

Kung-Cheng Ho

2016-05-01

Full Text Available Financial distress has been invoked in the asset pricing literature to explain the anomalous patterns in the cross-section of stock returns. The risk of financial distress can be measured using indexes. George and Hwang (2010 suggest that leverage can explain the distress risk puzzle and that firms with high costs choose low leverage to reduce distress intensities and earn high returns. This study investigates whether this relationship exists in the Taiwan market. When examined separately, distress intensity is found to be negatively related to stock returns, but leverage is found to not be significantly related to stock returns. The results are the same when distress intensity and leverage are examined simultaneously. After assessing the robustness by using O-scores, distress risk puzzle is found to exist in the Taiwan market, but the leverage puzzle is not

Discounting with Imperfect Collateral

OpenAIRE

Lou, Wujiang

2017-01-01

Cash collateral is perfect in that it provides simultaneous counterparty credit risk protection and derivatives funding. Securities are imperfect collateral, because of collateral segregation or differences in CSA haircuts and repo haircuts. Moreover, the collateral rate term structure is not observable in the repo market, for derivatives netting sets are perpetual while repo tenors are typically in months. This article synthesizes these effects into a derivative financing rate that replaces ...

Stateless Puzzles for Real Time Online Fraud Preemption

OpenAIRE

Rahman, Mizanur; Recabarren, Ruben; Carbunar, Bogdan; Lee, Dongwon

2017-01-01

The profitability of fraud in online systems such as app markets and social networks marks the failure of existing defense mechanisms. In this paper, we propose FraudSys, a real-time fraud preemption approach that imposes Bitcoin-inspired computational puzzles on the devices that post online system activities, such as reviews and likes. We introduce and leverage several novel concepts that include (i) stateless, verifiable computational puzzles, that impose minimal performance overhead, but e...

Hamlet — An Imperfect Humanist%Hamlet—An Imperfect Humanist

Institute of Scientific and Technical Information of China (English)

闫莹莹

2017-01-01

Hamlet is an eternal classic written by William Shakespeare. It drew much attention from the first edition and got a mixed reception. People argued about the characteristic of Hamlet during more than 400 years. Many western critics concerned Hamlet was hesitated, cowardly, oedipal and was not a humanist. However, investigators in China regarded Hamlet as a perfect humanist. It argues that the characteristic of Hamlet is so complicated, it can't be summarized in one sentence. It is sensible to make a comprehensive study on the limitation of Hamlet as a pure person in a world which the god withdraws. Began with cow-ardice and ended with peaceful death, Hamlet shows the soul of an imperfect humanist.

Studying the proton 'radius' puzzle with μp elastic scattering

International Nuclear Information System (INIS)

Gilman, R.

2013-01-01

The disagreement between the proton radius determined from muonic hydrogen and from electronic measurements is called the proton radius puzzle. The resolution of the puzzle remains unclear and appears to require new experimental results. An experiment to measure muon-proton elastic scattering is presented here

Combination of uncertainty theories and decision-aiding methods for natural risk management in a context of imperfect information

Science.gov (United States)

Tacnet, Jean-Marc; Dupouy, Guillaume; Carladous, Simon; Dezert, Jean; Batton-Hubert, Mireille

2017-04-01

In mountain areas, natural phenomena such as snow avalanches, debris-flows and rock-falls, put people and objects at risk with sometimes dramatic consequences. Risk is classically considered as a combination of hazard, the combination of the intensity and frequency of the phenomenon, and vulnerability which corresponds to the consequences of the phenomenon on exposed people and material assets. Risk management consists in identifying the risk level as well as choosing the best strategies for risk prevention, i.e. mitigation. In the context of natural phenomena in mountainous areas, technical and scientific knowledge is often lacking. Risk management decisions are therefore based on imperfect information. This information comes from more or less reliable sources ranging from historical data, expert assessments, numerical simulations etc. Finally, risk management decisions are the result of complex knowledge management and reasoning processes. Tracing the information and propagating information quality from data acquisition to decisions are therefore important steps in the decision-making process. One major goal today is therefore to assist decision-making while considering the availability, quality and reliability of information content and sources. A global integrated framework is proposed to improve the risk management process in a context of information imperfection provided by more or less reliable sources: uncertainty as well as imprecision, inconsistency and incompleteness are considered. Several methods are used and associated in an original way: sequential decision context description, development of specific multi-criteria decision-making methods, imperfection propagation in numerical modeling and information fusion. This framework not only assists in decision-making but also traces the process and evaluates the impact of information quality on decision-making. We focus and present two main developments. The first one relates to uncertainty and imprecision

Discrete Material Buckling Optimization of Laminated Composite Structures considering "Worst" Shape Imperfections

DEFF Research Database (Denmark)

Henrichsen, Søren Randrup; Lindgaard, Esben; Lund, Erik

2015-01-01

Robust design of laminated composite structures is considered in this work. Because laminated composite structures are often thin walled, buckling failure can occur prior to material failure, making it desirable to maximize the buckling load. However, as a structure always contains imperfections...... and “worst” shape imperfection optimizations to design robust composite structures. The approach is demonstrated on an U-profile where the imperfection sensitivity is monitored, and based on the example it can be concluded that robust designs can be obtained....

Vibration of imperfect rotating disk

Czech Academy of Sciences Publication Activity Database

Půst, Ladislav; Pešek, Luděk

2011-01-01

Roč. 5, č. 2 (2011), s. 205-216 ISSN 1802-680X R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : bladed disk * imperfect disk * travelling waves Subject RIV: BI - Acoustics http://www.kme.zcu.cz/acm/index.php/acm/article/view/86

The Effect of Monetary Policy on Exchange Rates : How to Solve the Puzzles

NARCIS (Netherlands)

Kumah, F.Y.

1996-01-01

Recent empirical research on the effects of monetary policy shocks on exchange rate fluctuations have encountered the exchange rate puzzle and th e forward discount bias puzzle.The exchange rate puzzle is the tendency of the domestic currency (of non-US G-7 countries) to depreciate against the US

Imperfect chemical female mimicry in males of the ant Cardiocondyla obscurior

Science.gov (United States)

Cremer, Sylvia; D'Ettorre, Patrizia; Drijfhout, Falko P.; Sledge, Matthew F.; Turillazzi, Stefano; Heinze, Jürgen

2008-11-01

Winged and wingless males coexist in the ant Cardiocondyla obscurior. Wingless (“ergatoid”) males never leave their maternal colony and fight remorselessly among each other for the access to emerging females. The peaceful winged males disperse after about 10 days, but beforehand also mate in the nest. In the first 5 days of their life, winged males perform a chemical female mimicry that protects them against attack and even makes them sexually attractive to ergatoid males. When older, the chemical profile of winged males no longer matches that of virgin females; nevertheless, they are still tolerated, which so far has been puzzling. Contrasting this general pattern, we have identified a single aberrant colony in which all winged males were attacked and killed by the ergatoid males. A comparative analysis of the morphology and chemical profile of these untypical attacked winged males and the tolerated males from several normal colonies revealed that normal old males are still performing some chemical mimicry to the virgin queens, though less perfect than in their young ages. The anomalous attacked winged males, on the other hand, had a very different odour to the females. Our study thus exemplifies that the analysis of rare malfunctioning can add valuable insight on functioning under normal conditions and allows the conclusion that older winged males from normal colonies of the ant C. obscurior are guarded through an imperfect chemical female mimicry, still close enough to protect against attacks by the wingless fighters yet dissimilar enough not to elicit their sexual interest.

Coupon advertising under imperfect price information

NARCIS (Netherlands)

Moraga-Gonzälez, José Luis; Petrakis, Emmanuel

1999-01-01

This paper studies sales promotions through coupons in an oligopoly under imperfect price information. Sellers can distribute either ordinary coupons, or coupon (price) advertising, or both types of coupons, at distant locations to attract consumers from their rivals' markets. A unique symmetric

THE EQUITY PREMIUM PUZZLE AND EMOTIONAL ASSET PRICING

OpenAIRE

MARC GÜRTLER; NORA HARTMANN

2007-01-01

"Since the equity premium as well as the risk-free rate puzzle question the concepts central to financial and economic modeling, we apply behavioral decision theory to asset pricing in view of solving these puzzles. U.S. stock market data for the period 1960-2003 and German stock market data for the period 1977-2003 show that emotional investors who act in accordance to Bell's (1985) disappointment theory -a special case of prospect theory- and additionally administer mental accounts demand a...

The π+-emission puzzle in 4ΛHe decay

International Nuclear Information System (INIS)

Gibson, B.F.; Timmermans, R.G.E.

1998-01-01

We re-examine the puzzling π + emission from the weak decay of 4 Λ He and propose an explanation in terms of a three-body decay of the virtual Σ + . Such a resolution of the π + decay puzzle is consistent with the calculated Σ + probability in light Λ hypernuclei as well as the experimentally observed π + energy spectrum and s-wave angular distribution. (orig.)

METODE BERMAIN PUZZLE BERPENGARUH PADA PERKEMBANGAN MOTORIK HALUS ANAK USIA PRASEKOLAH

Directory of Open Access Journals (Sweden)

Lilis Maghfuroh

2018-03-01

Full Text Available Pre-school is a period to increase fine motor development of children. This research aims to determine the increasing of fine motor development using the puzzle for preschoolers. his research is using one-group pre-post test design without control and procedures for statistical analysis through Wilcoxon Sign Rank Test with a confidence level of 95% and α: 5%. The subjects of this study were 40 children. The results of the analysis showed that there was effect of the intervention method by playing puzzle through the development of fine motor skills at pre-school children in mind that the value of Z sign p = 0.001 where significant value of p <0.05. Puzzle play method can improve child language development. The results of this research can be used as the basic for doing the puzzles therapy in children because it can improve fine motor skills development of children. Masa prasekolah merupakan masa peningkatan perkembangan motorik halus. Motorik halus adalah gerakan yang dilakukan oleh sekelompok otot-otot kecil seperti jari-jemari. Pada survey awal hampir sebagian anak mengalami perkembangan motorik suspek. Penelitian ini untuk mengetahui pengaruh metode puzzle terhadap perkembangan motorik halus anak pra sekolah. Penelitian ini menggunakan one-group pra-post test design tanpa control dan analisis statistik menggunakan Uji Wilcoxon Sign Rank Test dengan tingkat  kepercayaan 95% dan α : 5%. Populasi penelitian 50 anak dan sample 40 anak dengan tehnik Simple Random Sampling. Setelah data terkumpul dengan menggunakan DDST selanjutnya dianalisa. Hasil penelitian ini menunjukkan ada pengaruh metode bermain puzzle terhadap perkembangan motorik halus diketahui p sign = 0,001 dimana nilai signifikan p < 0,05. Hasil penelitian ini dapat dijadikan dasar untuk melakukan terapi puzzle pada anak untuk meningkatkan perkembangan motorik halus anak.

Quantum feedback for rapid state preparation in the presence of control imperfections

International Nuclear Information System (INIS)

Combes, Joshua; Wiseman, Howard M

2011-01-01

Quantum feedback control protocols can improve the operation of quantum devices. Here we examine the performance of a purification protocol when there are imperfections in the controls. The ideal feedback protocol produces an x-eigenstate from a mixed state in the minimum time, and is known as rapid state preparation. The imperfections we examine include time delays in the feedback loop, finite strength feedback, calibration errors and inefficient detection. We analyse these imperfections using the Wiseman-Milburn feedback master equation and related formalism. We find that the protocol is most sensitive to time delays in the feedback loop. For systems with slow dynamics, however, our analysis suggests that inefficient detection would be the bigger problem. We also show how system imperfections, such as dephasing and damping, can be included in a model via the feedback master equation.

Association of Crossword Puzzle Participation with Memory Decline in Persons Who Develop Dementia

Science.gov (United States)

Pillai, Jagan A.; Hall, Charles B.; Dickson, Dennis W.; Buschke, Herman; Lipton, Richard B.; Verghese, Joe

2013-01-01

Participation in cognitively stimulating leisure activities such as crossword puzzles may delay onset of the memory decline in the preclinical stages of dementia, possibly via its effect on improving cognitive reserve. We followed 488 initially cognitively intact community residing individuals with clinical and cognitive assessments every 12–18 months in the Bronx Aging Study. We assessed the influence of crossword puzzle participation on the onset of accelerated memory decline as measured by the Buschke Selective Reminding Test in 101 individuals who developed incident dementia using a change point model. Crossword puzzle participation at baseline delayed onset of accelerated memory decline by 2.54 years. Inclusion of education or participation in other cognitively stimulating activities did not significantly add to the fit of the model beyond the effect of puzzles. Our findings show that late life crossword puzzle participation, independent of education, was associated with delayed onset of memory decline in persons who developed dementia. Given the wide availability and accessibility of crossword puzzles, their role in preventing cognitive decline should be validated in future clinical trials. PMID:22040899

Effect of imperfect Faraday mirrors on the security of a Faraday–Michelson quantum cryptography system

International Nuclear Information System (INIS)

Wang, Wei-Long; Gao, Ming; Ma, Zhi

2013-01-01

The one-way Faraday–Michelson system is a very useful practical quantum cryptography system where Faraday mirrors (FMs) play an important role. In this paper we analyze the security of this system against imperfect FMs. We consider the security loophole caused by imperfect FMs in Alice’s and Bob’s security zones. Then we implement a passive FM attack in this system. By changing the values of the imperfection parameters of Alice’s FMs, we calculate the quantum bit error rate between Alice and Bob induced by Eve and the probability that Eve obtains outcomes successfully. It is shown that the imperfection of one of Alice’s two FMs makes the system sensitive to an attack. Finally we give a modified key rate as a function of the FM imperfections. The security analysis indicates that both Alice’s and Bob’s imperfect FMs can compromise the secure key. (paper)

Nature's Greatest Puzzles

International Nuclear Information System (INIS)

Quigg, Chris

2005-01-01

It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit

Construction-Paper Puzzle Masterpieces

Science.gov (United States)

Vance, Shelly

2010-01-01

Creating an appreciation of art history in her junior-high students has always been one of the author's greatest challenges as an art teacher. In this article, the author describes how her eighth-grade students re-created a famous work of art--piece by piece, like a puzzle or a stained-glass window--out of construction paper. (Contains 1 resource.)

The Ay puzzle and the nuclear force

International Nuclear Information System (INIS)

Hueber, D.

1999-01-01

The nucleon-deuteron analyzing power A y in elastic nucleon-deuteron scattering poses a longstanding puzzle. At energies E lab below approximately 30 MeV, A y cannot be described by any realistic NN force. The inclusion of existing three-nucleon forces does not improve the situation. Because of recent questions about the 3 P J NN phases, we examine whether reasonable changes in the NN force can resolve the puzzle. In order to do this, we investigate the effect on the 3 P J waves produced by changes in different parts of the potential (viz., the central force, tensor force, etc.), as well as on the 2-body observables and on A y . We find that it is not possible with reasonable changes in the NN potential to increase the 3-body A y , and at the same time to keep the 2-body observables unchanged. We therefore conclude that the A y puzzle is likely to be solved by new three-nucleon forces, such as those of spin-orbit type, which have not yet been taken into account. Refs. 7, tab. 1 (author)

The Ay puzzle and the nuclear force

International Nuclear Information System (INIS)

Hueber, D.; Friar, J.L.

1998-01-01

The nucleon-deuteron analyzing power A y in elastic nucleon-deuteron scattering poses a longstanding puzzle. At energies E lab below approximately 30 MeV A y cannot be described by any realistic nucleon-nucleon (NN) force. The inclusion of existing three-nucleon forces does not improve the situation. Because of recent questions about the 3 P J NN phases, we examine whether reasonable changes in the NN force can resolve the puzzle. In order to do this we investigate the effect on the 3 P J waves produced by changes in different parts of the potential (viz., the central force, tensor force, etc.), as well as on the two-body observables and on A y . We find that it is not possible with reasonable changes in the NN potential to increase the three-body A y and at the same time to keep the two-body observables unchanged. We therefore conclude that the A y puzzle is likely to be solved by new three-nucleon forces, such as those of the spin-orbit type, which have not yet been taken into account. copyright 1998 The American Physical Society

An Alternative Evaluation: Online Puzzle as a Course-End Activity

Science.gov (United States)

Genç, Zülfü; Aydemir, Emrah

2015-01-01

Purpose: The purpose of this study is to determine whether the use of online puzzles in the instructional process has an effect on student achievement and learning retention. This study examined students ' perception and experiences on use of puzzle as an alternative evaluation tool. To achieve this aim, the following hypotheses were tested: using…

The effect of linear imperfection in [001] direction on the thermal properties of silver crystal

Directory of Open Access Journals (Sweden)

J Davoodi

2013-09-01

Full Text Available  The aim of this investigation was to calculate the thermal properties of silver crystal in the presence of linear imperfection. The simulations were performed by molecular dynamics simulation technique in NPT as well as NVT ensemble based on quantum Sutton-Chen many body potential. The thermal properties including cohesive energy, melting temperature, isobaric heat capacity and thermal expansion of imperfect silver crystal were calculated and compared to those of the perfect crystal. Moreover, the quantities such as radial distribution function, order parameter and lindemann index were calculated in order to obtain information on crystal structure and disorder in atoms. All calculations were done both with liner imperfection in [001] direction and without imperfection at different temperature. The simulation results show that cohesive energy, linear thermal expansion coefficient increase and melting temperature, latent heat of fusion decrease with increasing linear imperfection. Also, the results show that linear imperfection has no effect on the heat capacity.

Teaching Imperfect Competition at the Principles Level.

Science.gov (United States)

Weber, William V.; Highfill, Jannett K.

1990-01-01

Argues that, although most economics textbooks' explanations of imperfect competition may involve three to five models, the concept can be taught using a single, simple model. Uses several business/economic examples as illustrations. (DB)

On the optimal degree of imperfect repair

International Nuclear Information System (INIS)

Finkelstein, Maxim

2015-01-01

A simple cost-wise comparison between the minimal and perfect repair of a system is discussed first using a relevant example. The main focus of this note, however, is on imperfect (general) repair. The best repair for our system in this case is defined as the one that corresponds to the optimal level (extent) of repair actions that minimize the long-run expected cost per unit of time. This complex optimization problem is considered for a specific imperfect repair model (Kijima II), using the developed earlier asymptotic approach to the corresponding virtual age modelling. It is shown that the optimal solution exists when the failure rate of a system tends to infinity as t tends to infinity and the corresponding cost function decreases sufficiently fast. An example illustrating the optimization procedure is considered

Make or buy decision model with multi-stage manufacturing process and supplier imperfect quality

Science.gov (United States)

Pratama, Mega Aria; Rosyidi, Cucuk Nur

2017-11-01

This research develops an make or buy decision model considering supplier imperfect quality. This model can be used to help companies make the right decision in case of make or buy component with the best quality and the least cost in multistage manufacturing process. The imperfect quality is one of the cost component that must be minimizing in this model. Component with imperfect quality, not necessarily defective. It still can be rework and used for assembly. This research also provide a numerical example and sensitivity analysis to show how the model work. We use simulation and help by crystal ball to solve the numerical problem. The sensitivity analysis result show that percentage of imperfect generally not affect to the model significantly, and the model is not sensitive to changes in these parameters. This is because the imperfect cost are smaller than overall total cost components.

Teaching Inductive Reasoning with Puzzles

Science.gov (United States)

Wanko, Jeffrey J.

2017-01-01

Working with language-independent logic structures can help students develop both inductive and deductive reasoning skills. The Japanese publisher Nikoli (with resources available both in print and online) produces a treasure trove of language-independent logic puzzles. The Nikoli print resources are mostly in Japanese, creating the extra…

Assessment of redundant systems with imperfect coverage by means of binary decision diagrams

Energy Technology Data Exchange (ETDEWEB)

Myers, Albert F. [Northrop Grumman Corporation, 1840 Century Park East, Los Angeles, CA 90067-2199 (United States)], E-mail: Al.Myers@ngc.com; Rauzy, Antoine [IML/CNRS, 163, Avenue de Luminy, 13288 Marseille Cedex 09 (France)], E-mail: arauzy@iml.univ-mrs.fr

2008-07-15

In this article, we study the assessment of the reliability of redundant systems with imperfect fault coverage. We term fault coverage as the ability of a system to isolate and correctly accommodate failures of redundant elements. For highly reliable systems, such as avionic and space systems, fault coverage is in general imperfect and has a significant impact on system reliability. We review here the different models of imperfect fault coverage. We propose efficient algorithms to assess them separately (as k-out-of-n selectors). We show how to implement these algorithms into a binary decision diagrams engine. Finally, we report experimental results on real life test cases that show on the one hand the importance of imperfect coverage and on the other hand the efficiency of the proposed approach.

The optimal production-run time for a stock-dependent imperfect production process

Directory of Open Access Journals (Sweden)

Jain Divya

2013-01-01

Full Text Available This paper develops an inventory model for a hypothesized volume flexible manufacturing system in which the production rate is stock-dependent and the system produces both perfect and imperfect quality items. The demand rate of perfect quality items is known and constant, whereas the demand rate of imperfect (non-conforming to specifications quality items is a function of discount offered in the selling price. In this paper, we determine an optimal production-run time and the optimal discount that should be offered in the selling price to influence the sale of imperfect quality items produced by the manufacturing system. The considered model aims to maximize the net profit obtained through the sales of both perfect and imperfect quality items subject to certain constraints of the system. The solution procedure suggests the use of ‘Interior Penalty Function Method’ to solve the associated constrained maximization problem. Finally, a numerical example demonstrating the applicability of proposed model has been included.

NICHD Research Networks Help Piece Together the Puzzle of Polycystic Ovary Syndrome

Science.gov (United States)

... Print NICHD research networks help piece together the puzzle of polycystic ovary syndrome Many people think that ... more like putting together a thousand-piece jigsaw puzzle. Except that you can’t check the cover ...

Robust buckling optimization of laminated composite structures using discrete material optimization considering “worst” shape imperfections

DEFF Research Database (Denmark)

Henrichsen, Søren Randrup; Lindgaard, Esben; Lund, Erik

2015-01-01

Robust buckling optimal design of laminated composite structures is conducted in this work. Optimal designs are obtained by considering geometric imperfections in the optimization procedure. Discrete Material Optimization is applied to obtain optimal laminate designs. The optimal geometric...... imperfection is represented by the “worst” shape imperfection. The two optimization problems are combined through the recurrence optimization. Hereby the imperfection sensitivity of the considered structures can be studied. The recurrence optimization is demonstrated through a U-profile and a cylindrical panel...... example. The imperfection sensitivity of the optimized structure decreases during the recurrence optimization for both examples, hence robust buckling optimal structures are designed....

Effect of geometric imperfections on the ultimate moment capacity of cold-formed sigma-shape se

Directory of Open Access Journals (Sweden)

Bassem L. Gendy

2017-08-01

Full Text Available In recent years, cold formed steel sections are used more and more as primary framing components and as a secondary structural system. They are used as purlins and side rails or floor joist, and after that in the building envelops. Beams are not perfectly straight and are usually associated with geometric imperfections. Initial geometric imperfections can significantly influence the stability response of cold-formed steel members. This paper reports a numerical investigation concerning the effect of these imperfections on the behavior of the simply supported beams subjected to a uniform bending moment. The beam profile is cold formed sigma sections. Group of beams with different overall member slenderness ratios were studied. Several approaches have been utilized to model the geometric imperfections. First, the elastic buckling modes were considered as the imperfect beam shape. In this approach, the elastic buckling analysis was done first to get the elastic buckling modes. In the second approach, the imperfections were considered by assuming the beam bent in a half sine wave along its length. Finally, combination of these two approaches was considered. Results reveal that, the ultimate bending moments of beams with short and intermediate overall slenderness ratios are sensitive to the imperfect shape that comprise compression flange local buckling.

On Non-Parallelizable Deterministic Client Puzzle Scheme with Batch Verification Modes

NARCIS (Netherlands)

Tang, Qiang; Jeckmans, Arjan

A (computational) client puzzle scheme enables a client to prove to a server that a certain amount of computing resources (CPU cycles and/or Memory look-ups) has been dedicated to solve a puzzle. Researchers have identified a number of potential applications, such as constructing timed cryptography,

Attenuation of thermal neutrons by an imperfect single crystal

Energy Technology Data Exchange (ETDEWEB)

Naguib, K.; Adib, M. [National Research Centre, Cairo (Egypt). Reactor and Neutron Physics Dept.

1996-06-14

A semi-empirical formula is given which allows one to calculate the total thermal cross section of an imperfect single crystal as a function of crystal constants, temperature and neutron energy E, in the energy range between 3 meV and 10 eV. The formula also includes the contribution of the parasitic Bragg scattering to the total cross section that takes into account the crystal mosaic spread value and its orientation with respect to the neutron beam direction. A computer program (ISCANF) was developed to calculate the total attenuation of neutrons using the proposed formula. The ISCANF program was applied to investigate the neutron attenuation through a copper single crystal. The calculated values of the neutron transmission through the imperfect copper single crystal were fitted to the measured ones in the energy range 3-40 meV at different crystal orientations. The result of fitting shows that use of the computer program ISCANF allows one to predict the behaviour of the total cross section of an imperfect copper single crystal for the whole energy range. (author).

Attenuation of thermal neutrons by an imperfect single crystal

Science.gov (United States)

Naguib, K.; Adib, M.

1996-06-01

A semi-empirical formula is given which allows one to calculate the total thermal cross section of an imperfect single crystal as a function of crystal constants, temperature and neutron energy E, in the energy range between 3 meV and 10 eV. The formula also includes the contribution of the parasitic Bragg scattering to the total cross section that takes into account the crystal mosaic spread value and its orientation with respect to the neutron beam direction. A computer program (ISCANF) was developed to calculate the total attenuation of neutrons using the proposed formula. The ISCANF program was applied to investigate the neutron attenuation through a copper single crystal. The calculated values of the neutron transmission through the imperfect copper single crystal were fitted to the measured ones in the energy range 3 - 40 meV at different crystal orientations. The result of fitting shows that use of the computer program ISCANF allows one to predict the behaviour of the total cross section of an imperfect copper single crystal for the whole energy range.

Lepton mixing and the 'solar neutrino puzzle'

International Nuclear Information System (INIS)

Bilenky, S.M.; Pontecorvo, B.

1977-01-01

The results of the well-known solar neutrino experiments in which the Cl-Ar method was employed are discussed; the results of this experiment gave a too-small neutrino signal and were referred to as the 'solar neutrino puzzle'. A number of explanations have been offered to account for the results, but it is stated that the explanation in terms of lepton mixing and neutrino sterility is attractive in terms of present day elementary particle physics and much more natural than the other explanations offered. Headings are as follows: neutrino oscillations and lepton charge, oscillations and solar neutrino experiments, lepton mixing according to old and present ideas, neutrino oscillations and the 'solar neutrino puzzle'. (U.K.)

"It's like a puzzle": Pregnant women's perceptions of professional support in midwifery care.

Science.gov (United States)

Bäckström, Caroline A; Mårtensson, Lena B; Golsäter, Marie H; Thorstensson, Stina A

2016-12-01

Pregnant women are not always satisfied with the professional support they receive during their midwifery care. More knowledge is needed to understand what professional support pregnant women need for childbirth and parenting. Childbearing and the transition to becoming a parent is a sensitive period in one's life during which one should have the opportunity to receive professional support. Professional support does not always correspond to pregnant women's needs. To understand pregnant women's needs for professional support within midwifery care, it is crucial to further illuminate women's experiences of this support. To explore pregnant women's perceptions of professional support in midwifery care. A qualitative study using semi-structured interviews. Fifteen women were interviewed during gestational weeks 36-38. Data was analysed using phenomenography. The women perceived professional support in midwifery care to be reassuring and emotional, to consist of reliable information, and to be mediated with pedagogical creativity. The professional support facilitated new social contacts, partner involvement and contributed to mental preparedness. The findings of the study were presented in six categories and the category Professional support contributes to mental preparedness was influenced by the five other categories. Pregnant women prepare for childbirth and parenting by using several different types of professional support in midwifery care: a strategy that could be described as piecing together a puzzle. When the women put the puzzle together, each type of professional support works as a valuable piece in the whole puzzle. Through this, professional support could contribute to women's mental preparedness for childbirth and parenting. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

The impact of memory load and perceptual cues on puzzle learning by 24-month olds.

Science.gov (United States)

Barr, Rachel; Moser, Alecia; Rusnak, Sylvia; Zimmermann, Laura; Dickerson, Kelly; Lee, Herietta; Gerhardstein, Peter

2016-11-01

Early childhood is characterized by memory capacity limitations and rapid perceptual and motor development [Rovee-Collier (1996). Infant Behavior & Development, 19, 385-400]. The present study examined 2-year olds' reproduction of a sliding action to complete an abstract fish puzzle under different levels of memory load and perceptual feature support. Experimental groups were compared to baseline controls to assess spontaneous rates of production of the target actions; baseline production was low across all experiments. Memory load was manipulated in Exp. 1 by adding pieces to the puzzle, increasing sequence length from 2 to 3 items, and to 3 items plus a distractor. Although memory load did not influence how toddlers learned to manipulate the puzzle pieces, it did influence toddlers' achievement of the goal-constructing the fish. Overall, girls were better at constructing the puzzle than boys. In Exp. 2, the perceptual features of the puzzle were altered by changing shape boundaries to create a two-piece horizontally cut puzzle (displaying bilateral symmetry), and by adding a semantically supportive context to the vertically cut puzzle (iconic). Toddlers were able to achieve the goal of building the fish equally well across the 2-item puzzle types (bilateral symmetry, vertical, iconic), but how they learned to manipulate the puzzle pieces varied as a function of the perceptual features. Here, as in Exp. 1, girls showed a different pattern of performance from the boys. This study demonstrates that changes in memory capacity and perceptual processing influence both goal-directed imitation learning and motoric performance. © 2016 Wiley Periodicals, Inc.

DNA is structured as a linear "jigsaw puzzle" in the genomes of Arabidopsis, rice, and budding yeast.

Science.gov (United States)

Liu, Yun-Hua; Zhang, Meiping; Wu, Chengcang; Huang, James J; Zhang, Hong-Bin

2014-01-01

Knowledge of how a genome is structured and organized from its constituent elements is crucial to understanding its biology and evolution. Here, we report the genome structuring and organization pattern as revealed by systems analysis of the sequences of three model species, Arabidopsis, rice and yeast, at the whole-genome and chromosome levels. We found that all fundamental function elements (FFE) constituting the genomes, including genes (GEN), DNA transposable elements (DTE), retrotransposable elements (RTE), simple sequence repeats (SSR), and (or) low complexity repeats (LCR), are structured in a nonrandom and correlative manner, thus leading to a hypothesis that the DNA of the species is structured as a linear "jigsaw puzzle". Furthermore, we showed that different FFE differ in their importance in the formation and evolution of the DNA jigsaw puzzle structure between species. DTE and RTE play more important roles than GEN, LCR, and SSR in Arabidopsis, whereas GEN and RTE play more important roles than LCR, SSR, and DTE in rice. The genes having multiple recognized functions play more important roles than those having single functions. These results provide useful knowledge necessary for better understanding genome biology and evolution of the species and for effective molecular breeding of rice.

Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

International Nuclear Information System (INIS)

Hirano, Shin'ichi; Nishi, Sakine; Kobayashi, Tsutomu

2017-01-01

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

Energy Technology Data Exchange (ETDEWEB)

Hirano, Shin' ichi; Nishi, Sakine; Kobayashi, Tsutomu, E-mail: s.hirano@rikkyo.ac.jp, E-mail: sakine@rikkyo.ac.jp, E-mail: tsutomu@rikkyo.ac.jp [Department of Physics, Rikkyo University, Toshima, Tokyo 171-8501 (Japan)

2017-07-01

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

Fossil Fuels, Backstop Technologies, and Imperfect Substitution

NARCIS (Netherlands)

van der Meijden, G.C.; Pittel, Karen; van der Ploeg, Frederick; Withagen, Cees

2014-01-01

This chapter studies the transition from fossil fuels to backstop technologies in a general equilibrium model in which growth is driven by research and development. The analysis generalizes the existing literature by allowing for imperfect substitution between fossil fuels and the new energy

Soft cooperative spectrum sensing performance under imperfect and non identical reporting channels

KAUST Repository

Ben Ghorbel, Mahdi

2015-02-01

Cooperation among cognitive radio users improves the spectrum sensing performance by combining local decisions measured over independent sensing channels, allowing reduction of miss-detection and false alarm probabilities. While most of the works in cooperative spectrum sensing techniques assume perfect channels between the cooperating users, this paper studies the effect of imperfect channels when local users report their sensed information to the fusion center. Cooperative detection and false-alarm probabilities are derived for a general scheme of imperfect reporting channels under non necessarily identical sensing and reporting channels. Numerical simulations show that imperfect reporting channels should be considered to optimize the cooperative sensing in terms of consumed energy and probability of error.

Robust topology optimization accounting for geometric imperfections

DEFF Research Database (Denmark)

Schevenels, M.; Jansen, M.; Lombaert, Geert

2013-01-01

performance. As a consequence, the actual structure may be far from optimal. In this paper, a robust approach to topology optimization is presented, taking into account two types of geometric imperfections: variations of (1) the crosssections and (2) the locations of structural elements. The first type...... is modeled by means of a scalar non-Gaussian random field, which is represented as a translation process. The underlying Gaussian field is simulated by means of the EOLE method. The second type of imperfections is modeled as a Gaussian vector-valued random field, which is simulated directly by means...... of the EOLE method. In each iteration of the optimization process, the relevant statistics of the structural response are evaluated by means of a Monte Carlo simulation. The proposed methodology is successfully applied to a test problem involving the design of a compliant mechanism (for the first type...

New data and an old puzzle

DEFF Research Database (Denmark)

Lee, S Hong; Byrne, Enda M; Hultman, Christina M

2015-01-01

BACKGROUND: A long-standing epidemiological puzzle is the reduced rate of rheumatoid arthritis (RA) in those with schizophrenia (SZ) and vice versa. Traditional epidemiological approaches to determine if this negative association is underpinned by genetic factors would test for reduced rates of one...

Panel data estimates of the production function and product and labor market imperfections

NARCIS (Netherlands)

Dobbelaere, S.; Mairesse, J.

2013-01-01

Consistent with two models of imperfect competition in the labor market-the efficient bargaining model and the monopsony model-we provide two extensions of a microeconomic version of Hall's framework for estimating price-cost margins. We show that both product and labor market imperfections generate

Europe vs. the U.S. A New Look at the Syndicated Loan Pricing Puzzle

OpenAIRE

Burietz, Aurore; Oosterlinck, Kim; Szafarz, Ariane

2017-01-01

According to the syndicated loan pricing puzzle (Carey and Nini, Journal of Finance, 2007) interest rates charged to corporate borrowers are lower in Europe than in the U.S. Our investigation suggests that controlling for region-specific credit ratings makes the Europe-U.S. gap insignificant, and solves the puzzle. We speculate that the puzzle originates from the lack of uniformity of accounting standards.

Fatigue Strength Assessment of Welded Mild Steel Joints Containing Bulk Imperfections

Directory of Open Access Journals (Sweden)

Martin Leitner

2018-04-01

Full Text Available This work investigates the effect of gas pores, as bulk imperfections, on the fatigue strength of welded mild steel joints. Two test series containing different butt joint geometries and weld process parameters are included in order to achieve two variable types of pore sizes. Based on the √area-parameter by Murakami, the test series can be grouped into imperfections exhibiting √area < 1000 µm and √area > 1000 µm. Fatigue tests at a load stress ratio of R = 0.1 are performed, which act as comparison for the subsequent fatigue estimation. To assess the fatigue resistance, the approaches by Murakami, De Kazinczy, and Mitchell are utilized, which highlight certain differences in the applicability depending on the imperfection size. It is found that, on one hand, Murakami’s approach is well suitable for both small and large gas pores depending on the applied model parameters. On the other hand, the fatigue concepts by De Kazinczy and Mitchell are preferably practicable for large defects with √area > 1000 µm. In addition, the method by Mitchell incorporates the stress concentration factor of the imperfection, which can be numerically computed considering the size, shape, and location of the gas pore, as presented in this paper.

Using imperfect advance demand information in forecasting

NARCIS (Netherlands)

Tan, T.

2008-01-01

In this paper, we consider the demand-forecasting problem of a make-to-stock system operating in a business-to-business environment where some customers provide information on their future orders, which are subject to changes in time, hence constituting imperfect advance demand information (ADI).

Puzzle Imaging: Using Large-Scale Dimensionality Reduction Algorithms for Localization.

Science.gov (United States)

Glaser, Joshua I; Zamft, Bradley M; Church, George M; Kording, Konrad P

2015-01-01

Current high-resolution imaging techniques require an intact sample that preserves spatial relationships. We here present a novel approach, "puzzle imaging," that allows imaging a spatially scrambled sample. This technique takes many spatially disordered samples, and then pieces them back together using local properties embedded within the sample. We show that puzzle imaging can efficiently produce high-resolution images using dimensionality reduction algorithms. We demonstrate the theoretical capabilities of puzzle imaging in three biological scenarios, showing that (1) relatively precise 3-dimensional brain imaging is possible; (2) the physical structure of a neural network can often be recovered based only on the neural connectivity matrix; and (3) a chemical map could be reproduced using bacteria with chemosensitive DNA and conjugative transfer. The ability to reconstruct scrambled images promises to enable imaging based on DNA sequencing of homogenized tissue samples.

Puzzles in studies of quantum chaos

International Nuclear Information System (INIS)

Xu Gongou

1994-01-01

Puzzles in studies of quantum chaos are discussed. From the view of global properties of quantum states, it is clarified that quantum chaos originates from the break-down of invariant properties of quantum canonical transformations. There exist precise correspondences between quantum and classical chaos

The Closed-End Funds Puzzle: A Survey Review

Directory of Open Access Journals (Sweden)

Marta Charrón

2009-09-01

Full Text Available The main objective of this paper is to explore the most salient research aimed at explaining the closed-end fund puzzle from both the traditional and behavioral finance perspectives. It provides a better understanding of closed-end fund behavior and motivates further research of closed-end funds, market efficiency, asset pricing and the traditional and behavioral finance paradigms. So far, none of the possible explanations from either traditional finance or behavioral finance have been able to fully account for the occurrence of the puzzle. It continues to be an important issue in the long standing debate between traditional finance and behavioral finance.

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students--a pilot study.

Science.gov (United States)

Rubinstein, Jack; Dhoble, Abhijeet; Ferenchick, Gary

2009-01-13

Most medical professionals are expected to possess basic electrocardiogram (EKG) interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9) received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6) received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. The average score after only traditional teaching was 4.07 +/- 2.08 while after only the puzzle session was 4.04 +/- 2.36 (p = 0.97). The average improvement after the traditional session was followed up with a puzzle session was 2.53 +/- 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 +/- 1.73 (p = 0.67). The final EKG exam score for this cohort (n = 15) was 84.1 compared to 86.6 (p = 0.22) for a comparable sample of medical students (n = 15) at a different campus. Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale.

JIGSAW PUZZLE IMPROVE FINE MOTOR ABILITIES OF UPPER EXTREMITIES IN POST-STROKE ISCHEMIC CLIENTS

Directory of Open Access Journals (Sweden)

Kusnanto Kusnanto

2017-06-01

Full Text Available Introduction: Ischemic stroke is a disease caused by focal cerebral ischemia, where is a decline in blood flow that needed for neuronal metabolism, leading to neurologic deficit include motor deficit such as fine motor skills impairment. Therapy of fine motor skills disorders is to improve motor function, prevent contractures and complications. These study aimed to identify the effect of playing Jigsaw Puzzle on muscle strength, extensive motion, and upper extremity fine motor skills in patients with ischemic stroke at Dr. Moewardi Hospital, Surakarta. Methods: Experimental Quasi pre-posttest one group control. The number of samples were 34 respondents selected using purposive sampling technique. The samples were divided into intervention and control groups. The intervention group was 17 respondents who were given standard treatment hospital and played Jigsaw Puzzle 2 times a day for six days. Control group is one respondent given by hospital standard therapy without given additional Jigsaw Puzzle game. Evaluation of these research is done on the first and seventh day for those groups. Result: The results showed that muscle strength, the range of joint motion and fine motor skills of upper extremities increased (p = 0.001 significantly after being given the Jigsaw Puzzle games. These means playing Jigsaw Puzzle increase muscle strength, the range of joint motion and upper extremity fine motor skill of ischemic stroke patients. Discussion and conclusion: Jigsaw puzzle game administration as additional rehabilitation therapy in upper extremity fine motor to minimize the occurrence of contractures and motor disorders in patients with ischemic stroke. Jigsaw puzzle game therapy capable of creating repetitive motion as a key of neurological rehabilitation in Ischemic Stroke. This study recommends using jigsaw puzzle game as one of intervention in the nursing care of Ischemic Stroke patients.

Initial stresses in two-layer metal domes due to imperfections of their production and assemblage

Directory of Open Access Journals (Sweden)

Lebed Evgeniy Vasil’evich

2015-04-01

Full Text Available The process of construction of two-layer metal domes is analyzed to illustrate the causes of initial stresses in the bars of their frames. It has been noticed that it is impossible to build such structures with ideal geometric parameters because of imperfections caused by objective reasons. These imperfections cause difficulties in the process of connection of the elements in the joints. The paper demonstrates the necessity of fitting operations during assemblage that involve force fitting and yield initial stresses due to imperfections. The authors propose a special method of computer modeling of enforced elimination of possible imperfections caused by assemblage process and further confirm the method by an analysis of a concrete metal dome.

Puzzles in modern biology. I. Male sterility, failure reveals design [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Steven A. Frank

2016-09-01

Full Text Available Many human males produce dysfunctional sperm. Various plants frequently abort pollen. Hybrid matings often produce sterile males. Widespread male sterility is puzzling. Natural selection prunes reproductive failure. Puzzling failure implies something that we do not understand about how organisms are designed. Solving the puzzle reveals the hidden processes of design.

A puzzling aspect of the effect of advance notice on unemployment

DEFF Research Database (Denmark)

Addision, John; Blackburn, McKinley L.

1995-01-01

Displaced male workers with generous periods of advance notice tend to move directly into reemployment faster than their non-notified counterparts but once unemployed tend to escape from unemployment much more slowly. We examine three potential explanations for this puzzle associated with unemplo......Displaced male workers with generous periods of advance notice tend to move directly into reemployment faster than their non-notified counterparts but once unemployed tend to escape from unemployment much more slowly. We examine three potential explanations for this puzzle associated...... with unemployment insurance, the endogeneity of notice, and differential search intensity. Of these alternatives, the evidence suggests that it is the additional but less productive search time during the notice interval that creates the appearance of a puzzle....

The infinity puzzle

CERN Document Server

Close, Frank

2011-01-01

We are living in a Golden Age of Physics. Forty or so years ago, three brilliant, yet little-known scientists - an American, a Dutchman, and an Englishman - made breakthroughs which later inspired the construction of the Large Hadron Collider at CERN in Geneva: a 27 kilometer-long machine which has already costs ten billion dollars, taken twenty years to build, and now promises to reveal how the universe itself came to be. The Infinity Puzzle is the inside story of those forty years of research, breakthrough, and endeavour. Peter Higgs, Gerard 't Hooft and James Bjorken, were the three scienti

Bullet-Block Science Video Puzzle

Science.gov (United States)

Shakur, Asif

2015-01-01

A science video blog, which has gone viral, shows a wooden block shot by a vertically aimed rifle. The video shows that the block hit dead center goes exactly as high as the one shot off-center. (Fig. 1). The puzzle is that the block shot off-center carries rotational kinetic energy in addition to the gravitational potential energy. This leads a…

Mechanism of formation and growth of sunflower-shaped imperfections in anodic oxide films on niobium

Energy Technology Data Exchange (ETDEWEB)

Nagahara, K. [Graduate School of Engineering, Hokkaido University, N13 W8 Kita-ku, Sapporo 060-8628 (Japan); Sakairi, M. [Graduate School of Engineering, Hokkaido University, N13 W8 Kita-ku, Sapporo 060-8628 (Japan); Takahashi, H. [Graduate School of Engineering, Hokkaido University, N13 W8 Kita-ku, Sapporo 060-8628 (Japan)]. E-mail: Takahasi@elechem1-mc.eng.hokudai.ac.jp; Matsumoto, K. [Cabot Supermetals K.K., Higashinagahara Works, 111 Nagayachi, Kawahigashi-machi, Kawanuma-gun, Fukushima-ken 969-3431 (Japan); Takayama, K. [Cabot Supermetals K.K., Higashinagahara Works, 111 Nagayachi, Kawahigashi-machi, Kawanuma-gun, Fukushima-ken 969-3431 (Japan); Oda, Y. [Cabot Supermetals K.K., Higashinagahara Works, 111 Nagayachi, Kawahigashi-machi, Kawanuma-gun, Fukushima-ken 969-3431 (Japan)

2007-01-01

Anodizing of niobium has been investigated to develop niobium solid electrolytic capacitors. Chemically polished niobium specimens were anodized in a diluted phosphoric acid solution, initially galvanostatically at i {sub a} = 4 A m{sup -2} up to E {sub a} = 100 V, and then potentiostatically at E {sub a} = 100 V for t {sub pa} = 43.2 ks. During the galvanostatic anodizing, the anode potential increased almost linearly with time, while, during potentiostatic anodizing, the anodic current decreased up to t {sub pa} = 3.6 ks, and then increased slowly before decreasing again after t {sub pa} = 30.0 ks. Images of FE-SEM and in situ AFM showed that nuclei of imperfections were formed at the ridge of cell structures before t {sub pa} = 3.6 ks. After formation, the imperfection nuclei grew, showing cracking and rolling-up of the anodic oxide film, and crystalline oxide was formed at the center of imperfections after t {sub pa} = 3.6 ks. The growth of imperfections caused increases in the anodic current between t {sub pa} = 3.6 and 30.0 ks. Long-term anodizing caused a coalescence of the imperfections, leading to decreases in the anodic current after t {sub pa} = 30.0 ks. As the imperfections grew, the dielectric dispersion of the anodic oxide films became serious, showing a bias voltage dependence of the parallel equivalent capacitance, C {sub p}, and a dielectric dissipation factor, tan {delta}. The mechanism of formation and growth of the imperfections, and the correlation between the structure and dielectric properties of anodic oxide films is discussed.

On Entry Deterrence and Imperfectly Observable Commitment

DEFF Research Database (Denmark)

Poulsen, Anders

2001-01-01

We analyse a simple entry-deterrence game, where a `Potential Intruder' only imperfectly observes the decision of an `Incumbent' to commit or to not commit to fight any entry by the Potential Intruder. Our game generalises the one studied in Bonanno (1992) by allowing for a richer information tec...

The Puzzle of the Scandinavian Welfare State and Social Trust

DEFF Research Database (Denmark)

Svendsen, Gunnar Lind Haase; Svendsen, Gert Tinggaard

2015-01-01

The Scandinavian welfare model is a puzzle to economists: It works economically, even though free-riding should prevail with its explosive cocktail of high taxation and high social benefits. One overlooked solution to the puzzle could be the unique stock of social trust present in Scandinavia. Here......, the four Scandinavian countries (Norway, Denmark, Sweden, and Finland) form the top three with scores above 60 percent social trust on a ranking that covers 94 countries from all over the world....

Crossword Puzzle Makes It Fun: Introduce Green Manufacturing in Wood Technology Courses

Science.gov (United States)

Iley, John L.; Hague, Doug

2012-01-01

Sustainable, or "green," manufacturing and its practices are becoming more and more a part of today's industry, including wood product manufacturing. This article provides introductory information on green manufacturing in wood technology and a crossword puzzle based on green manufacturing terms. The authors use the puzzle at the college level to…

What Puzzles Teachers in Rio de janeiro, and What Keeps Them Going?

Science.gov (United States)

Lyra, Isolina; Fish, Solange; Braga, Walewska Gomes

2003-01-01

Focuses on the key mechanism of "puzzling" in Exploratory Practice (EP), a form of practitioner research, and the critical issue of sustainability in the context of volunteer teacher development work in Rio de Janeiro, Brazil. Investigated puzzles (concerns) of language teachers and grouped them into six categories; motivation, anxiety,…

Penyelesaian Masalah 8-Puzzle dengan Algoritma Steepest-Ascent Hill Climbing

Directory of Open Access Journals (Sweden)

David Abraham

2016-03-01

Full Text Available 8 puzzle merupakan salah satu implementasi dari Artificial Intelegence. Dalam proses penyelesaiannya banyak terdapat algoritma-algoritma pencarian yang dapat diterapkan. Solusi 8 puzzle akan lebih cepat diperoleh jika digunakan prinsip array dengan variasi algoritma Steepest-Ascent Hill Climbing (Hill Climbing dengan memilih kemiringan yang paling tajam / curam dengan parameter heuristik posisi yang benar dan heuristik jarak serta dikombinasikan dengan LogList sebagai penyimpanan state state yang pernah dilalui untuk menanggulangi permasalah pada algoritma hill climbing itu sendiri dan terhindar dari looping state yang pernah dilalui. Metode-metode yang termasuk ke dalam teknik pencarian yang berdasarkan pada fungsi heuristik salah satu diantaranya adalah Hill Climbing, Best First Search, A* (A Bintang. Loglist merupakan tempat penyimpanan setiap kunjungan dari state-state puzzle yang telah dilakukan untuk menghindari looping atau pengulangan terhadap state yang pernah dilalui. Untuk menanggulangi permasalahan pada SteepestAscent Hill Climbing.

Peelle's pertinent puzzle: Way of solution

International Nuclear Information System (INIS)

Pronyaev, V.G.

2003-01-01

The effect of evident bias of evaluated data below the majority of experimental data observed in general least-squares model fitting of these data is called as Peelle's Pertinent Puzzle (PPP). Since the transformation of the central values is trivial, the solution by transformation of covariance matrices is deducted

Strategic Information Disclosure and Competition for an Imperfectly Protected Innovation

DEFF Research Database (Denmark)

Jansen, Jos

2010-01-01

The imperfect appropriability of revenues from innovation affects the incentives of firms to invest, and to disclose information about their innovative productivity. It creates a free-rider effect in the competition for the innovation that countervails the familiar business-stealing effect. Moreo...... appropriability and strategic disclosure for the firms’ profits and the probability of innovation.......The imperfect appropriability of revenues from innovation affects the incentives of firms to invest, and to disclose information about their innovative productivity. It creates a free-rider effect in the competition for the innovation that countervails the familiar business-stealing effect...

Parameter identification of an electrically actuated imperfect microbeam

KAUST Repository

Ruzziconi, Laura

2013-12-01

In this study we consider a microelectromechanical system (MEMS) and focus on extracting analytically the model parameters that describe its non-linear dynamic features accurately. The device consists of a clamped-clamped polysilicon microbeam electrostatically and electrodynamically actuated. The microbeam has imperfections in the geometry, which are related to the microfabrication process, resulting in many unknown and uncertain parameters of the device. The objective of the present paper is to introduce a simple but appropriate model which, despite the inevitable approximations, is able to describe and predict the most relevant aspects of the experimental response in a neighborhood of the first symmetric resonance. The modeling includes the main imperfections in the microstructure. The unknown parameters are settled via parametric identification. The approach is developed in the frequency domain and is based on matching both the frequency values and, remarkably, the frequency response curves, which are considered as the most salient features of the device response. Non-linearities and imperfections considerably complicate the identification process. Via the combined use of linear analysis and non-linear dynamic simulations, a single first symmetric mode reduced-order model is derived. Extensive numerical simulations are performed at increasing values of electrodynamic excitation. Comparison with experimental data shows a satisfactory concurrence of results not only at low electrodynamic voltage, but also at higher ones. This validates the proposed theoretical approach. We highlight its applicability, both in similar case-studies and, more in general, in systems. © 2013 Elsevier Ltd.

Imperfect Gold Standards for Kidney Injury Biomarker Evaluation

Science.gov (United States)

Betensky, Rebecca A.; Emerson, Sarah C.; Bonventre, Joseph V.

2012-01-01

Clinicians have used serum creatinine in diagnostic testing for acute kidney injury for decades, despite its imperfect sensitivity and specificity. Novel tubular injury biomarkers may revolutionize the diagnosis of acute kidney injury; however, even if a novel tubular injury biomarker is 100% sensitive and 100% specific, it may appear inaccurate when using serum creatinine as the gold standard. Acute kidney injury, as defined by serum creatinine, may not reflect tubular injury, and the absence of changes in serum creatinine does not assure the absence of tubular injury. In general, the apparent diagnostic performance of a biomarker depends not only on its ability to detect injury, but also on disease prevalence and the sensitivity and specificity of the imperfect gold standard. Assuming that, at a certain cutoff value, serum creatinine is 80% sensitive and 90% specific and disease prevalence is 10%, a new perfect biomarker with a true 100% sensitivity may seem to have only 47% sensitivity compared with serum creatinine as the gold standard. Minimizing misclassification by using more strict criteria to diagnose acute kidney injury will reduce the error when evaluating the performance of a biomarker under investigation. Apparent diagnostic errors using a new biomarker may be a reflection of errors in the imperfect gold standard itself, rather than poor performance of the biomarker. The results of this study suggest that small changes in serum creatinine alone should not be used to define acute kidney injury in biomarker or interventional studies. PMID:22021710

An Empirical Evaluation of Puzzle-Based Learning as an Interest Approach for Teaching Introductory Computer Science

Science.gov (United States)

Merrick, K. E.

2010-01-01

This correspondence describes an adaptation of puzzle-based learning to teaching an introductory computer programming course. Students from two offerings of the course--with and without the puzzle-based learning--were surveyed over a two-year period. Empirical results show that the synthesis of puzzle-based learning concepts with existing course…

Supersymmetry, the flavour puzzle and rare B decays

International Nuclear Information System (INIS)

Straub, David Michael

2010-01-01

The gauge hierarchy problem and the flavour puzzle belong to the most pressing open questions in the Standard Model of particle physics. Supersymmetry is arguably the most popular framework of physics beyond the Standard Model and provides an elegant solution to the gauge hierarchy problem; however, it aggravates the flavour puzzle. In the first part of this thesis, I discuss several approaches to address the flavour puzzle in the minimal supersymmetric extension of the Standard Model and experimental tests thereof: supersymmetric grand unified theories with a unification of Yukawa couplings at high energies, theories with minimal flavour violation and additional sources of CP violation and theories with gauge mediation of supersymmetry breaking and a large ratio of Higgs vacuum expectation values. In the second part of the thesis, I discuss the phenomenology of two rare B meson decay modes which are promising probes of physics beyond the Standard Model: The exclusive B → K * l + l - decay, whose angular decay distribution will be studied at LHC and gives access to a large number of observables and the b→sνanti ν decays, which are in the focus of planned high-luminosity Super B factories. I discuss the predictions for these observables in the Standard Model and their sensitivity to New Physics. (orig.)

An overview of heavy quark energy loss puzzle at RHIC

International Nuclear Information System (INIS)

Djordjevic, Magdalena

2006-01-01

We give a theoretical overview of the heavy quark tomography puzzle posed by recent non-photonic single electron data from central Au+Au collisions at √s = 200A GeV. We show that radiative energy loss mechanisms alone are not able to explain large single electron suppression data, as long as realistic parameter values are assumed. We argue that a combined collisional and radiative pQCD approach can solve a substantial part of the non-photonic single electron puzzle

Dissolving the Puzzle of Resultant Moral Luck.

Science.gov (United States)

Levy, Neil

The puzzle of resultant moral luck arises when we are disposed to think that an agent who caused a harm deserves to be blamed more than an otherwise identical agent who did not. One popular (but controversial) perspective on resultant moral luck explains our dispositions to produce different judgments with regard to the agents who feature in these cases as a product not of what they genuinely deserve but of our epistemic situation. On this account, there is no genuine resultant moral luck; there is only luck in what evidence becomes available to observers. In this paper, I develop an evolutionary account of our inclination to take the results of actions as evidence for the mental states of agents, thereby explaining why the resulting intuitions are recalcitrant to correction. The account explains why the puzzle of resultant moral luck arises: because our disposition to take the harms agents cause as evidence of their mental states can produce intuitions which conflict with those that arise when we examine agents' mental states without reference to the results of their actions. The account also helps to solve the puzzle of resultant moral luck, by providing a strong reason to ignore the intuitions caused by our disposition to regard actual harms as evidence of mental states. Since these intuitions arise using an unreliable proxy for agents' mental states, they ought to be trumped by more reliable evidence.

Do Market Regulation and Financial Imperfections Affect Firm Size? New Empirical Evidence

OpenAIRE

Raquel Fonseca; Natalia Utrero González

2004-01-01

This paper investigates the importance that market regulation and financial imperfections have in firm size. We analyse institutions affecting labour market as Employment Protection Laws (EPL) and Product Market Regulation (PMR). Moreover, we study the effects of these institutions on firm growth. We use data from 29 industrial sectors across 15 developed countries. We find that market regulations related to financial imperfections help to explain differences in firm structure across countries.

Jigsaw Puzzles As Cognitive Enrichment (PACE) - the effect of solving jigsaw puzzles on global visuospatial cognition in adults 50 years of age and older: study protocol for a randomized controlled trial.

Science.gov (United States)

Fissler, Patrick; Küster, Olivia C; Loy, Laura S; Laptinskaya, Daria; Rosenfelder, Martin J; von Arnim, Christine A F; Kolassa, Iris-Tatjana

2017-09-06

Neurocognitive disorders are an important societal challenge and the need for early prevention is increasingly recognized. Meta-analyses show beneficial effects of cognitive activities on cognition. However, high financial costs, low intrinsic motivation, logistic challenges of group-based activities, or the need to operate digital devices prevent their widespread application in clinical practice. Solving jigsaw puzzles is a cognitive activity without these hindering characteristics, but cognitive effects have not been investigated yet. With this study, we aim to evaluate the effect of solving jigsaw puzzles on visuospatial cognition, daily functioning, and psychological outcomes. The pre-posttest, assessor-blinded study will include 100 cognitively healthy adults 50 years of age or older, who will be randomly assigned to a jigsaw puzzle group or a cognitive health counseling group. Within the 5-week intervention period, participants in the jigsaw puzzle group will engage in 30 days of solving jigsaw puzzles for at least 1 h per day and additionally receive cognitive health counseling. The cognitive health counseling group will receive the same counseling intervention but no jigsaw puzzles. The primary outcome, global visuospatial cognition, will depict the average of the z-standardized performance scores in visuospatial tests of perception, constructional praxis, mental rotation, processing speed, flexibility, working memory, reasoning, and episodic memory. As secondary outcomes, we will assess the eight cognitive abilities, objective and subjective visuospatial daily functioning, psychological well-being, general self-efficacy, and perceived stress. The primary data analysis will be based on mixed-effects models in an intention-to-treat approach. Solving jigsaw puzzles is a low-cost, intrinsically motivating, cognitive leisure activity, which can be executed alone or with others and without the need to operate a digital device. In the case of positive results

Effect of a puzzle on the process of students' learning about cardiac physiology.

Science.gov (United States)

Cardozo, Lais Tono; Miranda, Aline Soares; Moura, Maria José Costa Sampaio; Marcondes, Fernanda Klein

2016-09-01

The aim of the present study was to evaluate the effects of using a puzzle to learn about cardiac physiology. Students were divided into control and game groups. In class 1, the control group had a 2-h theoretical class about cardiac physiology, including a detailed description of the phases of the cardiac cycle, whereas the game group had a 50-min theoretical class without the description of the cardiac cycle. In class 2, the control group did an assessment exercise before an activity with the cardiac puzzle and the game group answered questions after the above-mentioned activity. While solving the puzzle, the students had to describe the cardiac cycle by relating the concepts of heart morphology and physiology. To evaluate short-term learning, the number of wrong answers and grades in the assessment exercise were compared between the control and game groups. To evaluate medium-term learning, we compared the grades obtained by students of the control and game groups in questions about cardiac physiology that formed part of the academic exam. In the assessment exercise, the game group presented a lower number of errors and higher score compared with the control group. In the academic exam, applied after both groups had used the puzzle, there was no difference in the scores obtained by the control and game groups in questions about cardiac physiology. These results showed a positive effect of the puzzle on students' learning about cardiac physiology compared with those not using the puzzle. Copyright © 2016 The American Physiological Society.

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students – a pilot study

Science.gov (United States)

Rubinstein, Jack; Dhoble, Abhijeet; Ferenchick, Gary

2009-01-01

Background Most medical professionals are expected to possess basic electrocardiogram (EKG) interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. Methods This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9) received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6) received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. Results The average score after only traditional teaching was 4.07 ± 2.08 while after only the puzzle session was 4.04 ± 2.36 (p = 0.97). The average improvement after the traditional session was followed up with a puzzle session was 2.53 ± 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 ± 1.73 (p = 0.67). The final EKG exam score for this cohort (n = 15) was 84.1 compared to 86.6 (p = 0.22) for a comparable sample of medical students (n = 15) at a different campus. Conclusion Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale. PMID:19144134

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students – a pilot study

Directory of Open Access Journals (Sweden)

Dhoble Abhijeet

2009-01-01

Full Text Available Abstract Background Most medical professionals are expected to possess basic electrocardiogram (EKG interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. Methods This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9 received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6 received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. Results The average score after only traditional teaching was 4.07 ± 2.08 while after only the puzzle session was 4.04 ± 2.36 (p = 0.97. The average improvement after the traditional session was followed up with a puzzle session was 2.53 ± 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 ± 1.73 (p = 0.67. The final EKG exam score for this cohort (n = 15 was 84.1 compared to 86.6 (p = 0.22 for a comparable sample of medical students (n = 15 at a different campus. Conclusion Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale.

Solving jigsaw puzzles using image features

DEFF Research Database (Denmark)

Nielsen, Ture R.; Drewsen, Peter; Hansen, Klaus

2008-01-01

In this article, we describe a method for automatic solving of the jigsaw puzzle problem based on using image features instead of the shape of the pieces. The image features are used for obtaining an accurate measure for edge similarity to be used in a new edge matching algorithm. The algorithm i...

A generalization of the Pasadena puzzle

NARCIS (Netherlands)

Peterson, M.B.

2013-01-01

By generalizing the Pasadena puzzle introduced by Nover and Hájek (2004) we show that the sum total of value produced by an act can be made to converge to any real number by applying the Riemann rearrangement theorem, even if the scenario faced by the decision maker is non-probabilistic and fully

Effects of mask imperfections on InP etching profiles

International Nuclear Information System (INIS)

Huo, D.T.C.; Yan, M.F.; Wynn, J.D.; Wilt, D.P.

1990-01-01

The authors have demonstrated that the quality of etch masks has a significant effect on the InP etching profiles. In particular, the authors have shown that mask imperfections can cause defective etching profiles, such as vertical sidewalls and extra mask undercutting in InP. The authors also discovered that the geometry of these defective profiles is determined by the orientation of the substrate relative to the direction of the mask imperfections. Along a left-angle 110 right-angle line mask defect, the downward etching process changes the left-angle 110 right-angle v-grooves to vertical sidewalls without extra undercutting. For v-grooves aligned along the left-angle 110 right-angle direction, defects on the mask give a significant extra undercutting without changing the etching profile

Strongly nonlinear free vibration of four edges simply supported stiffened plates with geometric imperfections

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhaoting; Wang, Rong Hui; Chen, Li; Dong, Chung Uang [School of Civil Engineering and Transportation, South China University of Technology, Guangzhou (China)

2016-08-15

This article investigated the strongly nonlinear free vibration of four edges simply supported stiffened plates with geometric imperfections. The von Karman nonlinear strain-displacement relationships are applied. The nonlinear vibration of stiffened plate is reduced to a one-degree-of-freedom nonlinear system by assuming mode shapes. The Multiple scales Lindstedt-Poincare method (MSLP) and Modified Lindstedt-Poincare method (MLP) are used to solve the governing equations of vibration. Numerical examples for stiffened plates with different initial geometric imperfections are presented in order to discuss the influences to the strongly nonlinear free vibration of the stiffened plate. The results showed that: the frequency ratio reduced as the initial geometric imperfections of plate increased, which showed that the increase of the initial geometric imperfections of plate can lead to the decrease of nonlinear effect; by comparing the results calculated by MSLP method, using MS method to study strongly nonlinear vibration can lead to serious mistakes.

PuzzleArt Therapy: Connecting the Pieces in Search of Answers

Directory of Open Access Journals (Sweden)

Jennifer Fortuna

2016-10-01

Full Text Available Alli Berman, a New York based artist, provided the cover art for the Fall 2016 issue of The Open Journal of Occupational Therapy (OJOT. “Sunlight Underwater” is a 12 piece PuzzleArt painting made from acrylic on American maple that measures 22x30. The PuzzleArt concept began as a simple exercise that evolved into a therapeutic modality. When a sudden stroke impacted Berman’s well-being and quality of life, it was art that helped her to make connections during recovery.

Propagation of SH waves in a piezoelectric/piezomagnetic plate: Effects of interfacial imperfection couplings and the related physical mechanisms

Energy Technology Data Exchange (ETDEWEB)

Wei, Hong-Xing [Beijing Advanced Innovation Center for Imaging Technology, Capital Normal University, Beijing 100048 (China); Li, Yong-Dong, E-mail: LYDbeijing@163.com [Beijing Advanced Innovation Center for Imaging Technology, Capital Normal University, Beijing 100048 (China); Department of Mechanical Engineering, Academy of Armored Force Engineering, Beijing 100072 (China); Xiong, Tao [Department of Mechanical Engineering, Academy of Armored Force Engineering, Beijing 100072 (China); Guan, Yong [Beijing Advanced Innovation Center for Imaging Technology, Capital Normal University, Beijing 100048 (China)

2016-09-07

The problem of dispersive SH wave in a piezoelectric/piezomagnetic plate that contains an imperfect interface is considered in the present work. An imperfection coupling model is adopted to describe the magnetic, electric and mechanical imperfections on the interface. A transcendental dispersion equation is derived and numerically solved to get the phase velocity. The validity of the numerical procedure is verified in a degenerated case. The effects of the coupled interfacial imperfections on the dispersion behavior of SH waves are discussed in detail and the related underlying physical mechanisms are explained. - Highlights: • SH-wave is investigated in a multiferroic plate with coupled interfacial imperfections. • SH-wave is affected by both interfacial imperfections and their inter-couplings. • Physical mechanisms of the effects are explained via energy transformations.

Propagation of SH waves in a piezoelectric/piezomagnetic plate: Effects of interfacial imperfection couplings and the related physical mechanisms

International Nuclear Information System (INIS)

Wei, Hong-Xing; Li, Yong-Dong; Xiong, Tao; Guan, Yong

2016-01-01

The problem of dispersive SH wave in a piezoelectric/piezomagnetic plate that contains an imperfect interface is considered in the present work. An imperfection coupling model is adopted to describe the magnetic, electric and mechanical imperfections on the interface. A transcendental dispersion equation is derived and numerically solved to get the phase velocity. The validity of the numerical procedure is verified in a degenerated case. The effects of the coupled interfacial imperfections on the dispersion behavior of SH waves are discussed in detail and the related underlying physical mechanisms are explained. - Highlights: • SH-wave is investigated in a multiferroic plate with coupled interfacial imperfections. • SH-wave is affected by both interfacial imperfections and their inter-couplings. • Physical mechanisms of the effects are explained via energy transformations.

Free-style puzzle flap: the concept of recycling a perforator flap.

Science.gov (United States)

Feng, Kuan-Ming; Hsieh, Ching-Hua; Jeng, Seng-Feng

2013-02-01

Theoretically, a flap can be supplied by any perforator based on the angiosome theory. In this study, the technique of free-style perforator flap dissection was used to harvest a pedicled or free skin flap from a previous free flap for a second difficult reconstruction. The authors call this a free-style puzzle flap. For the past 3 years, the authors treated 13 patients in whom 12 pedicled free-style puzzle flaps were harvested from previous redundant free flaps and recycled to reconstruct soft-tissue defects at various anatomical locations. One free-style free puzzle flap was harvested from a previous anterolateral thigh flap for buccal cancer to reconstruct a foot defect. Total flap survival was attained in 12 of 13 flaps. One transferred flap failed completely. This patient had received postoperative radiotherapy after the initial cancer ablation and free anterolateral thigh flap reconstruction. Another free flap was used to close and reconstruct the wound. All the donor sites could be closed primarily. The free-style puzzle flap, harvested from a previous redundant free flap and used as a perforator flap to reconstruct a new defect, has proven to be versatile and reliable. When indicated, it is an alternative donor site for further reconstruction of soft-tissue defects.

Managerial Meta-knowledge, Uncertainty, and Adaptation

DEFF Research Database (Denmark)

Jensen, Henrik; Foss, Nicolai Juul

"Managerial Meta-Knowledge, Uncertainty, and Adaptation: Governance Choice when Firms do not Know their Capabilities" Much research on economic organization (e.g., transaction cost economics) is based on an assumption that firms accurately know their own capabilities. In terms of what managers know...... about the resources of the firm (including employee knowledge) we argue that this amounts to an assumption of perfect managerial meta-knowledge. However, research streams on resource cognition, transaction memory and organizational self- knowledge suggests that this assumption is not in general...... warranted. We examine the implications for economic organization of less-than-perfect managerial meta-knowledge. Specifically, we show that imperfect managerial meta- knowledge is a cause of surprises in contractual relationships, affects the ability of coordinated adaptation, and an opportunism...

Family caregivers of palliative cancer patients at home: the puzzle of pain management.

Science.gov (United States)

Mehta, Anita; Cohen, S Robin; Carnevale, Franco A; Ezer, Hélène; Ducharme, Francine

2010-01-01

The purpose of this grounded theory study was to understand the processes used by family caregivers to manage the pain of cancer patients at home. A total of 24 family caregivers participated. They were recruited using purposeful then theoretical sampling. The data sources were taped, transcribed (semi-structured) interviews and field notes. Data analysis was based on Strauss and Corbin's (1998) requirements for open, axial, and selective coding. The result was an explanatory model titled "the puzzle of pain management," which includes four main processes: "drawing on past experiences"; "strategizing a game plan"; "striving to respond to pain"; and "gauging the best fit," a decision-making process that joins the puzzle pieces. Understanding how family caregivers assemble their puzzle pieces can help health care professionals make decisions related to the care plans they create for pain control and help them to recognize the importance of providing information as part of resolving the puzzle of pain management.

The 20th anniversary of the three-nucleon analyzing power puzzle - a personal recollection

International Nuclear Information System (INIS)

Tornow, W. . Author

2008-01-01

The history of the three-nucleon analyzing power puzzle is described by an experimentalist who has been collaborating with few-body theoreticians in trying to unravel the physics of this long-standing phenomenon. Although surprising effects have been discovered along the way, the puzzle is still unexplained. Hopefully, some of the long-range three-nucleon force terms predicted by chiral effective field theory in N 3 LO will eventually solve the puzzle. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

Neutron star news and puzzles

International Nuclear Information System (INIS)

Prakash, Madappa

2014-01-01

Gerry Brown has had the most influence on my career in Physics, and my life after graduate studies. This article gives a brief account of some of the many ways in which Gerry shaped my research. Focus is placed on the significant strides on neutron star research made by the group at Stony Brook, which Gerry built from scratch. Selected puzzles about neutron stars that remain to be solved are noted

ESTIMATION OF THE KNOWLEDGE SPILLOVER EFFECTS BETWEEN FIRMS IN BIO-RELATED INDUSTRIES

OpenAIRE

Kim, Hanho; Kim, Jae-Kyung

2005-01-01

Knowledge spillover is a kind of externality originating from imperfect appropriation of R&D performances, which implies that the knowledge created by one agent could be transmitted to other related agents by affecting their R&D or other economic performances. For the estimation of knowledge spillover effects based on firm-level patent data between firms in bio-related industries, patents production function, as a proxy of knowledge production function, is formulated and estimated. Knowledge ...

A Puzzle Guide to Gödel

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Forever Undecided: A Puzzle Guide to Gödel. R Ramanujam. Book Review Volume 6 Issue 7 July 2001 pp 97-98. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/006/07/0097-0098 ...

The Forward-Bias Puzzle: A Solution Based on Covered Interest Parity

OpenAIRE

Pippenger, John

2009-01-01

The forward-bias puzzle is probably the most important puzzle in international macroeconomics. After more than 20 years, there is no accepted solution. My solution is based on covered interest parity (CIP). CIP implies: (1) Forward rates are not rational expectations of future spot rates. Those expectations depend on future spot rates and interest rate differentials. (2) The forward bias is the result of a specification error, replacing future forward exchange rates with current forward ...

Study of the nonlinear imperfect software debugging model

International Nuclear Information System (INIS)

Wang, Jinyong; Wu, Zhibo

2016-01-01

In recent years there has been a dramatic proliferation of research on imperfect software debugging phenomena. Software debugging is a complex process and is affected by a variety of factors, including the environment, resources, personnel skills, and personnel psychologies. Therefore, the simple assumption that debugging is perfect is inconsistent with the actual software debugging process, wherein a new fault can be introduced when removing a fault. Furthermore, the fault introduction process is nonlinear, and the cumulative number of nonlinearly introduced faults increases over time. Thus, this paper proposes a nonlinear, NHPP imperfect software debugging model in consideration of the fact that fault introduction is a nonlinear process. The fitting and predictive power of the NHPP-based proposed model are validated through related experiments. Experimental results show that this model displays better fitting and predicting performance than the traditional NHPP-based perfect and imperfect software debugging models. S-confidence bounds are set to analyze the performance of the proposed model. This study also examines and discusses optimal software release-time policy comprehensively. In addition, this research on the nonlinear process of fault introduction is significant given the recent surge of studies on software-intensive products, such as cloud computing and big data. - Highlights: • Fault introduction is a nonlinear changing process during the debugging phase. • The assumption that the process of fault introduction is nonlinear is credible. • Our proposed model can better fit and accurately predict software failure behavior. • Research on fault introduction case is significant to software-intensive products.

Regulation of Danish energy markets with imperfect competition

International Nuclear Information System (INIS)

Goertz, M.; Hansen, J.V.

1999-01-01

In this paper we use a new CGE model of the Danish economy with the acronym ECOSMEC (Economic COuncil Simulation Model with Energy markets and Carbon taxation). The model is a hybrid of two existing static models developed by respectively the Secretariat of the Danish Economic Council and by the MobiDK project in the Ministry of Business and Industry. Distinct features of the ECOSMEC model are a rather disaggregated modelling of energy demand and supply, introduction of various market structures in the energy sector, and a consistent specification of different household types. The simulations presented in the paper have the following implications: First, a uniform CO 2 tax of approximately 300 DKK per ton CO 2 could reduce emissions by 20 per cent in a scenario with perfect competition in the energy sector. However, assuming different market structures in the energy sector influences the uniform CO 2 tax needed to reach a given emission target. In the paper we assume that the Danish energy sector is a natural monopoly regulated to comply with average cost pricing, but we also discuss alternative descriptions of imperfect competition. Second, the empirical arguments for differentiated CO 2 taxes motivated by imperfect energy markets are weak. This is in line with earlier international studies on environmental taxes and imperfect competition. Third, the Danish economy could benefit from a deregulation of the electricity and district heating sector with respect to welfare and economic activity. This result holds also if CO 2 emissions are kept constant. (au)

Statistical inference for imperfect maintenance models with missing data

International Nuclear Information System (INIS)

Dijoux, Yann; Fouladirad, Mitra; Nguyen, Dinh Tuan

2016-01-01

The paper considers complex industrial systems with incomplete maintenance history. A corrective maintenance is performed after the occurrence of a failure and its efficiency is assumed to be imperfect. In maintenance analysis, the databases are not necessarily complete. Specifically, the observations are assumed to be window-censored. This situation arises relatively frequently after the purchase of a second-hand unit or in the absence of maintenance record during the burn-in phase. The joint assessment of the wear-out of the system and the maintenance efficiency is investigated under missing data. A review along with extensions of statistical inference procedures from an observation window are proposed in the case of perfect and minimal repair using the renewal and Poisson theories, respectively. Virtual age models are employed to model imperfect repair. In this framework, new estimation procedures are developed. In particular, maximum likelihood estimation methods are derived for the most classical virtual age models. The benefits of the new estimation procedures are highlighted by numerical simulations and an application to a real data set. - Highlights: • New estimation procedures for window-censored observations and imperfect repair. • Extensions of inference methods for perfect and minimal repair with missing data. • Overview of maximum likelihood method with complete and incomplete observations. • Benefits of the new procedures highlighted by simulation studies and real application.

The role of helioseismology in the knowledge of the solar interior dynamics and in the solar neutrino puzzle

International Nuclear Information System (INIS)

Couvidat, Sebastien

2002-01-01

This dissertation focuses on the solar interior dynamics and the neutrino puzzle, using helioseismology and more specifically the SoHO/GOLF data as a tool to probe the radiative interior of the Sun. We show how helioseismology gives us a direct access to the deep-layer dynamics through the solar rotation profile. Our data favor a decrease of the rotation velocity near the nuclear core. This can be used to constrain the angular momentum distribution processes, and to set an upper bound on the intensity of the magnetic field in this part of the Sun. The search for gravity modes with an original method is another topic of this dissertation. Several candidates are detected that need now to be confirmed. Gravity modes will give us a precious insight into the solar core structure and dynamics. We also use the stellar evolution code CESAM. By combining seismic data and solar modelling, we produce solar seismic models. The neutrino flux predictions from these models are partly derived on an observational basis. The comparison of these fluxes with the SNO results gives the solution to the solar neutrino puzzle: neutrinos have masses and they oscillate between different lepton flavors. This explains the deficit of detections observed since the sixties. We also work on the internal magnetic fields that take part to the dynamic processes. In particular, we start to study the impact of these fields on the neutrino production and transport. Finally, we reach the limits of the 1D stellar codes: they cannot take into account the dynamic processes efficiently. This justifies the current development of 2D or 3D codes. (author) [fr

On the low SNR capacity of MIMO fading channels with imperfect channel state information

KAUST Repository

Benkhelifa, Fatma

2014-06-01

The capacity of multiple-input multiple-output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low signal-to-noise ratio (SNR) essentially as SNR log(1/SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In this paper, we mainly focus on the low SNR regime, and we show that the capacity scales as (1-α) SNR log(1/SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can be also extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 1972-2012 IEEE.

On the low SNR capacity of MIMO fading channels with imperfect channel state information

KAUST Repository

Benkhelifa, Fatma

2014-05-01

The capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low Signal-to-Noise Ratio (SNR) essentially as SNR log(1=SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In our work, we mainly focus on the low SNR regime and we show that the capacity scales as (1-α) SNR log(1=SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can also be extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 2014 IFIP.

Vibration of circular bladed disk with imperfections

Czech Academy of Sciences Publication Activity Database

Půst, Ladislav; Pešek, Luděk

2011-01-01

Roč. 21, č. 10 (2011), s. 2893-2904 ISSN 0218-1274 R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : circular bladed disk * vibration * imperfection * nonlinear damping Subject RIV: BI - Acoustics Impact factor: 0.755, year: 2011 http://www.worldscinet.com/ijbc/21/2110/S0218127411030210.html

The Meissner effect puzzle and the quantum force in superconductor

International Nuclear Information System (INIS)

Nikulov, A.V.

2012-01-01

The puzzle of the acceleration of the mobile charge carriers and the ions in the superconductor in direction opposite to the electromagnetic force revealed formerly in the Meissner effect is considered in the case of the transition of a narrow ring from normal to superconducting state. It is elucidated that the azimuthal quantum force was deduced eleven years ago from the experimental evidence of this acceleration but it cannot solve this puzzle. This quantum force explains other paradoxical phenomena connected with reiterated switching of the ring between normal and superconducting states.

Analytical predictions for vibration phase shifts along fluid-conveying pipes due to Coriolis forces and imperfections

DEFF Research Database (Denmark)

Thomsen, Jon Juel; Dahl, Jonas

2010-01-01

-shift measuring devices such as Coriolis mass flowmeters in particular. Small imperfections related to elastic and dissipative support conditions are specifically addressed, but the suggested approach is readily applicable to other kinds of imperfection, e.g. non-uniform stiffness or mass, non......-proportional damping, weak nonlinearity, and flow pulsation. A multiple time scaling perturbation analysis is employed for a simple model of an imperfect fluid-conveying pipe. This leads to simple analytical expressions for the approximate prediction of phase shift, providing direct insight into which imperfections...... the symmetric part of damping as well as non-uniformity in mass or stiffness do not affect phase shift. The validity of such hypotheses can be tested using detailed fluid-structure interaction computer models or laboratory experiments....

Isotope puzzle in sputtering

International Nuclear Information System (INIS)

Zheng Liping

1998-01-01

Mechanisms affecting multicomponent material sputtering are complex. Isotope sputtering is the simplest in the multicomponent materials sputtering. Although only mass effect plays a dominant role in the isotope sputtering, there is still an isotope puzzle in sputtering by ion bombardment. The major arguments are as follows: (1) At the zero fluence, is the isotope enrichment ejection-angle-independent or ejection-angle-dependent? (2) Is the isotope angular effect the primary or the secondary sputter effect? (3) How to understand the action of momentum asymmetry in collision cascade on the isotope sputtering?

Supersymmetry, the flavour puzzle and rare B decays

Energy Technology Data Exchange (ETDEWEB)

Straub, David Michael

2010-07-14

The gauge hierarchy problem and the flavour puzzle belong to the most pressing open questions in the Standard Model of particle physics. Supersymmetry is arguably the most popular framework of physics beyond the Standard Model and provides an elegant solution to the gauge hierarchy problem; however, it aggravates the flavour puzzle. In the first part of this thesis, I discuss several approaches to address the flavour puzzle in the minimal supersymmetric extension of the Standard Model and experimental tests thereof: supersymmetric grand unified theories with a unification of Yukawa couplings at high energies, theories with minimal flavour violation and additional sources of CP violation and theories with gauge mediation of supersymmetry breaking and a large ratio of Higgs vacuum expectation values. In the second part of the thesis, I discuss the phenomenology of two rare B meson decay modes which are promising probes of physics beyond the Standard Model: The exclusive B {yields} K{sup *}l{sup +}l{sup -} decay, whose angular decay distribution will be studied at LHC and gives access to a large number of observables and the b{yields}s{nu}anti {nu} decays, which are in the focus of planned high-luminosity Super B factories. I discuss the predictions for these observables in the Standard Model and their sensitivity to New Physics. (orig.)

KEEFEKTIFAN MODEL PEMBELAJARAN WORD SQUARE BERBANTU MEDIA PUZZLE PADA MATA PELAJARAN IPS SD

Directory of Open Access Journals (Sweden)

IBNATUL IZZATI

2018-01-01

Full Text Available Abstract                The problems of this research was: how the effectiveness of Word Square learning model supported by Puzzle media to improve learning outcome of Social subject of third grade at Public Elementary School of Wonopringgo 01 (SDN 01 Wonopringgo? The type of this research was True Experiment Design with type of pretest-posttest control group design one kind of treatment. The samples were taken from students of the third grade of A SDN 01 Wonopringgo in the academic year 2016/2017. The data in this study was obtained through tests and documentation. Experimental research on the third grade of A which was given Word Square learning model supported by Puzzle media and the third grade of B was not given Word Square learning model supported by Puzzle media. Posttest results showed that the percentage of posttest grade of the experimental class was 95% of students expressed thoroughly, while the control class is 70%, and based on t test one-party analysis obtained ttest > ttable = 3,100816112> 1.72. Thus, it could be concluded that the learning with Word Square model supported by Puzzle media was effective against student learning outcomes in Social subjects (IPS the third grade at SDN 01 Wonopringgo Pekalongan. Keywords : effectiveness, word square, puzzle

A Hierarchical Interface Design of a Puzzle Game for Elementary Education

OpenAIRE

Eun-Young Park; Young-Ho Park

2010-01-01

A basic instinct of humans for perfect completion usually drives us happy. Basically, humans purchase a certain complete match for scattered facts. The satisfaction of completing the scattered pieces gives us great pleasure. Thus many people put in their time and effort in the puzzle, and they gain strong satisfaction. The paper solves the importance of the general effects of a puzzle in building the edu-game design. Legacy online education has following problems. First, educational effects b...

The Imperfect Child in Early Twentieth-Century Russia

Science.gov (United States)

Byford, Andy

2017-01-01

The article discusses the role that conceptualisations of child "imperfection" played in the rise and fall of Russian "child study" between the 1900s and the 1930s. Drawing on Georges Canguilhem's ideas on "the normal" and "the pathological", the article analyses practices centred on diagnosing subnormality…

A solution to B→ππ puzzle and B→KK

International Nuclear Information System (INIS)

Baek, Seungwon

2008-01-01

The large ratio of color-suppressed tree amplitude to color-allowed one in B→ππ decays is difficult to understand within the Standard Model, which is known as the 'B→ππ puzzle'. The two tree diagrams contain the up- and charm-quark component of penguin amplitude, P uc , which cannot be separated by measuring B→ππ decays alone. We show that the measurements of the branching ratio and direct CP asymmetry of B + →K + K 0 -bar decay enable one to disentangle the P uc with two-fold ambiguity. One of the two degenerate solutions of the P uc can solve the B→ππ puzzle by giving |C/T|∼0.3 which is consistent with the expectation in the Standard Model. We also show that the two solutions can be discriminated by the measurement of the indirect CP asymmetry of B 0 →K 0 K 0 -bar. We point out that the corresponding puzzle in B→πK decays is not solved in this way

From static to rotating to conformal static solutions: rotating imperfect fluid wormholes with(out) electric or magnetic field

Energy Technology Data Exchange (ETDEWEB)

Azreg-Ainou, Mustapha [Baskent University, Department of Mathematics, Ankara (Turkey)

2014-05-15

We derive a shortcut stationary metric formula for generating imperfect fluid rotating solutions, in Boyer-Lindquist coordinates, from spherically symmetric static ones. We explore the properties of the curvature scalar and stress-energy tensor for all types of rotating regular solutions we can generate without restricting ourselves to specific examples of regular solutions (regular black holes or wormholes). We show through examples how it is generally possible to generate an imperfect fluid regular rotating solution via radial coordinate transformations. We derive rotating wormholes that are modeled as imperfect fluids and discuss their physical properties. These are independent on the way the stress-energy tensor is interpreted. A solution modeling an imperfect fluid rotating loop black hole is briefly discussed. We then specialize to the recently discussed stable exotic dust Ellis wormhole as emerged in a source-free radial electric or magnetic field, and we generate its, conjecturally stable, rotating counterpart. This turns out to be an exotic imperfect fluid wormhole, and we determine the stress-energy tensor of both the imperfect fluid and the electric or magnetic field. (orig.)

From static to rotating to conformal static solutions: rotating imperfect fluid wormholes with(out) electric or magnetic field

International Nuclear Information System (INIS)

Azreg-Ainou, Mustapha

2014-01-01

We derive a shortcut stationary metric formula for generating imperfect fluid rotating solutions, in Boyer-Lindquist coordinates, from spherically symmetric static ones. We explore the properties of the curvature scalar and stress-energy tensor for all types of rotating regular solutions we can generate without restricting ourselves to specific examples of regular solutions (regular black holes or wormholes). We show through examples how it is generally possible to generate an imperfect fluid regular rotating solution via radial coordinate transformations. We derive rotating wormholes that are modeled as imperfect fluids and discuss their physical properties. These are independent on the way the stress-energy tensor is interpreted. A solution modeling an imperfect fluid rotating loop black hole is briefly discussed. We then specialize to the recently discussed stable exotic dust Ellis wormhole as emerged in a source-free radial electric or magnetic field, and we generate its, conjecturally stable, rotating counterpart. This turns out to be an exotic imperfect fluid wormhole, and we determine the stress-energy tensor of both the imperfect fluid and the electric or magnetic field. (orig.)

Accounting for imperfect detection of groups and individuals when estimating abundance.

Science.gov (United States)

Clement, Matthew J; Converse, Sarah J; Royle, J Andrew

2017-09-01

If animals are independently detected during surveys, many methods exist for estimating animal abundance despite detection probabilities account for imperfect detection of groups, while assuming that individuals within groups are detected perfectly. However, this assumption is often unsupported. We introduce an abundance estimator for grouped animals when detection of groups is imperfect and group size may be under-counted, but not over-counted. The estimator combines an MRDS model with an N-mixture model to account for imperfect detection of individuals. The new MRDS-Nmix model requires the same data as an MRDS model (independent detection histories, an estimate of distance to transect, and an estimate of group size), plus a second estimate of group size provided by the second observer. We extend the model to situations in which detection of individuals within groups declines with distance. We simulated 12 data sets and used Bayesian methods to compare the performance of the new MRDS-Nmix model to an MRDS model. Abundance estimates generated by the MRDS-Nmix model exhibited minimal bias and nominal coverage levels. In contrast, MRDS abundance estimates were biased low and exhibited poor coverage. Many species of conservation interest reside in groups and could benefit from an estimator that better accounts for imperfect detection. Furthermore, the ability to relax the assumption of perfect detection of individuals within detected groups may allow surveyors to re-allocate resources toward detection of new groups instead of extensive surveys of known groups. We believe the proposed estimator is feasible because the only additional field data required are a second estimate of group size.

Effect of geometrical imperfection on buckling failure of ITER VVPSS tank

International Nuclear Information System (INIS)

Jha, Saroj Kumar; Gupta, Girish Kumar; Pandey, Manish Kumar; Bhattacharya, Avik; Jogi, Gaurav; Bhardwaj, Anil Kumar

2015-01-01

The 'Vacuum Vessel Pressure Suppression System' (VVPSS) is Part of ITER machine, which is designed to protect the ITER Vacuum Vessel and its connected systems, from an over-pressure situation. It is comprised of a partially evacuated tank of stainless steel approximately 46 meters long and 6 meters in diameter and thickness 30mm. It is to hold approximately 675 tonnes of water at room temperature to condense the steam resulting from the adverse water leakage into the Vacuum Vessel chamber. For any vacuum vessel, geometrical imperfection has significant effect on buckling failure and structural integrity. Major geometrical imperfection in VVPSS tank depends on form tolerances. To study the effect of geometrical imperfection on buckling failure of VVPSS tank, finite element analysis (FEA) has been performed in line with ASME section VIII division 2 part 5, 'design by analysis method'. Linear buckling analysis has been performed to get the buckled shape and displacement. Geometrical imperfection due to form tolerance is incorporated in FEA model of VVPSS tank by scaling the resulted buckled shape by a factor '60'. This buckled shape model is used as input geometry for plastic collapse and buckling failure assessment. Plastic collapse and buckling failure of VVPSS tank has been assessed by using the elastic-plastic analysis method. This analysis has been performed for different values of form tolerance. The results of analysis show that displacement and load proportionality factor (LPF) vary inversely with form tolerance. For higher values of form tolerance LPF reduces significantly with high values of displacement. (author)

Precedents, Patterns and Puzzles: Feminist Reflections on the First Women Lawyers

Directory of Open Access Journals (Sweden)

Mary Jane Mossman

2016-10-01

Full Text Available This paper initially examines the historical precedents established by some of the first women who entered the “gentleman’s profession” of law in different jurisdictions, as well as the biographical patterns that shaped some women’s ambitions to enter the legal professions. The paper then uses feminist methods and theories to interpret “puzzles that remain unsolved” about early women lawyers, focusing especially on two issues. One puzzle is the repeated claims on the part of many of these early women lawyers that they were “lawyers”, and not “women lawyers”, even as they experienced exclusionary practices and discrimination on the part of male lawyers and judges—a puzzle that suggests how professional culture required women lawyers to conform to existing patterns in order to succeed. A second puzzle relates to the public voices of early women lawyers, which tended to suppress disappointments, difficulties and discriminatory practices. In this context, feminist theories suggest a need to be attentive to the “silences” in women’s stories, including the stories of the lives of early women lawyers. Moreover, these insights may have continuing relevance for contemporary women lawyers because it is at least arguable that, while there have been changes in women’s experiences, there has been very little transformation in their work status in relation to men.

Formative Assessment Probes: Mountaintop Fossil: A Puzzling Phenomenon

Science.gov (United States)

Keeley, Page

2015-01-01

This column focuses on promoting learning through assessment. This month's issue describes using formative assessment probes to uncover several ways of thinking about the puzzling discovery of a marine fossil on top of a mountain.

The DS86 neutron dosimetry enigma: Some missing pieces to the puzzle

International Nuclear Information System (INIS)

Gold, R.

1994-01-01

International programs have been conducted over the last four decades to quantify the exposure of atom bomb survivors from Hiroshima and Nagasaki. Unfortunately, the quest for accurate gamma-ray and neutron exposure doses of atom bomb survivors has proven illusive. Efforts in the most recent of these programs, designated as Dosimetry System 1986 (DS86), have revealed a serious and persistent discrepancy between neutron transport calculations and thermal neutron activation measurements at the Hiroshima site, which will be called the DS86 neutron dosimetry enigma. It is established that this enigma is a complex puzzle that precludes simple solutions. This conclusion is deduced through the identification of a number of missing pieces to the puzzle. Implications and conclusions that can be inferred from these missing puzzle pieces are advanced

Welfare improving barter in imperfect competition

OpenAIRE

CRESTI, Barbara

2002-01-01

This paper offers a rationale for the development of the barter industry in industrialized economies. It argues that, in a context of imperfect competition, barter represents a profitable and efficient system of exchange. Thanks to barter, even if already at the optimum, a monopolist can still reduce the production costs and thus increase profits. Moreover, by adopting a barter strategy, he also improves social welfare, as he raises total output and decreases market price. Social welfare impr...

Effect of imperfections on the hyperuniformity of many-body systems

Science.gov (United States)

Kim, Jaeuk; Torquato, Salvatore

2018-02-01

A hyperuniform many-body system is characterized by a structure factor S (k ) that vanishes in the small-wave-number limit or equivalently by a local number variance σN2(R ) associated with a spherical window of radius R that grows more slowly than Rd in the large-R limit. Thus, the hyperuniformity implies anomalous suppression of long-wavelength density fluctuations relative to those in typical disordered systems, i.e., σN2(R ) ˜Rd as R →∞ . Hyperuniform systems include perfect crystals, quasicrystals, and special disordered systems. Disordered hyperuniform systems are amorphous states of matter that lie between a liquid and crystal [S. Torquato et al., Phys. Rev. X 5, 021020 (2015), 10.1103/PhysRevX.5.021020], and have been the subject of many recent investigations due to their novel properties. In the same way that there is no perfect crystal in practice due to the inevitable presence of imperfections, such as vacancies and dislocations, there is no "perfect" hyperuniform system, whether it is ordered or not. Thus, it is practically and theoretically important to quantitatively understand the extent to which imperfections introduced in a perfectly hyperuniform system can degrade or destroy its hyperuniformity and corresponding physical properties. This paper begins such a program by deriving explicit formulas for S (k ) in the small-wave-number regime for three types of imperfections: (1) uncorrelated point defects, including vacancies and interstitials, (2) stochastic particle displacements, and (3) thermal excitations in the classical harmonic regime. We demonstrate that our results are in excellent agreement with numerical simulations. We find that "uncorrelated" vacancies or interstitials destroy hyperuniformity in proportion to the defect concentration p . We show that "uncorrelated" stochastic displacements in perfect lattices can never destroy the hyperuniformity but it can be degraded such that the perturbed lattices fall into class III

Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties.

Science.gov (United States)

Jiao, Da; Liu, Zengqian; Zhang, Zhenjun; Zhang, Zhefeng

2015-07-22

Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials.

Integrated preventive maintenance and production decisions for imperfect processes

International Nuclear Information System (INIS)

Nourelfath, Mustapha; Nahas, Nabil; Ben-Daya, Mohamed

2016-01-01

This paper integrates production, maintenance, and quality for an imperfect process in a multi-period multi-product capacitated lot-sizing context. The production system is modeled as an imperfect machine, whose the status is considered to be either in-control or out-of-control. When the machine is out of control, it produces a fraction of nonconforming items. During each period, this machine is inspected and imperfect preventive maintenance activities are simultaneously performed to reduce its age, proportional to the preventive maintenance level. The objective is to minimize the total cost, while satisfying the demand for all products. Our optimization model allows for a joint selection of the optimal values of production plan, and the maintenance policy, while taking into account quality related costs. A solution algorithm is developed and illustrative numerical examples are presented. It is found that the increase in PM level leads to reductions in quality control costs. Furthermore, if the cost of performing PM is high to the point where it is not compensated for by reductions in the quality related costs, then performing PM is not justifiable. Finally, using non-periodic preventive maintenance with the possibility of different preventive maintenance levels may result in an improvement of the total cost. - Highlights: • We integrate production, maintenance, and quality. • We evaluate all the expected costs. • Our model allows for a joint selection of the optimal values. • A solution algorithm is developed. • Increasing PM level will decrease quality control costs.

Two-phonon bound states in imperfect crystals

International Nuclear Information System (INIS)

Behera, S.N.; Samsur, Sk.

1980-01-01

The question of the occurrence of two-phonon bound states in imperfect crystals is investigated. It is shown that the anharmonicity mediated two-phonon bound state which is present in perfect crystals gets modified due to the presence of impurities. Moreover, the possibility of the occurrence of a purely impurity mediated two-phonon bound state is demonstrated. The bound state frequencies are calculated using the simple Einstein oscillator model for the host phonons. The two-phonon density of states for the imperfect crystal thus obtained has peaks at the combination and difference frequencies of two host phonons besides the peaks at the bound state frequencies. For a perfect crystal the theory predicts a single peak at the two-phonon bound state frequency in conformity with experimental observations and other theoretical calculations. Experimental data on the two-phonon infrared absorption and Raman scattering from mixed crystals of Gasub(1-c)Alsub(c)P and Gesub(1-c)Sisub(c) are analysed to provide evidence in support of impurity-mediated two-phonon bound states. The relevance of the zero frequency (difference spectrum) peak to the central peak, observed in structural phase transitions, is conjectured. (author)

Engineering Application Way of Faults Knowledge Discovery Based on Rough Set Theory

International Nuclear Information System (INIS)

Zhao Rongzhen; Deng Linfeng; Li Chao

2011-01-01

For the knowledge acquisition puzzle of intelligence decision-making technology in mechanical industry, to use the Rough Set Theory (RST) as a kind of tool to solve the puzzle was researched. And the way to realize the knowledge discovery in engineering application is explored. A case extracting out the knowledge rules from a concise data table shows out some important information. It is that the knowledge discovery similar to the mechanical faults diagnosis is an item of complicated system engineering project. In where, first of all-important tasks is to preserve the faults knowledge into a table with data mode. And the data must be derived from the plant site and should also be as concise as possible. On the basis of the faults knowledge data obtained so, the methods and algorithms to process the data and extract the knowledge rules from them by means of RST can be processed only. The conclusion is that the faults knowledge discovery by the way is a process of rising upward. But to develop the advanced faults diagnosis technology by the way is a large-scale knowledge engineering project for long time. Every step in which should be designed seriously according to the tool's demands firstly. This is the basic guarantees to make the knowledge rules obtained have the values of engineering application and the studies have scientific significance. So, a general framework is designed for engineering application to go along the route developing the faults knowledge discovery technology.

Novel Robust Optimization and Power Allocation of Time Reversal-MIMO-UWB Systems in an Imperfect CSI

Directory of Open Access Journals (Sweden)

Sajjad Alizadeh

2013-03-01

Full Text Available Time Reversal (TR technique is an attractive solution for a scenario where the transmission system employs low complexity receivers with multiple antennas at both transmitter and receiver sides. The TR technique can be combined with a high data rate MIMO-UWB system as TR-MIMO-UWB system. In spite of TR's good performance in MIMO-UWB systems, it suffers from performance degradation in an imperfect Channel State Information (CSI case. In this paper, at first a robust TR pre-filter is designed together with a MMSE equalizer in TR-MIMO-UWB system where is robust against channel imperfection conditions. We show that the robust pre-filter optimization technique, considerably improves the BER performance of TR-MIMO-UWB system in imperfect CSI, where temporal focusing of the TR technique is kept, especially for high SNR values. Then, in order to improve the system performance more than ever, a power loading scheme is developed by minimizing the average symbol error rate in an imperfect CSI. Numerical and simulation results are presented to confirm the performance advantage attained by the proposed robust optimization and power loading in an imperfect CSI scenario.

Piecing It Together: The Effect of Background Music on Children's Puzzle Assembly.

Science.gov (United States)

Koolidge, Louis; Holmes, Robyn M

2018-04-01

This study explored the effects of background music on cognitive (puzzle assembly) task performance in young children. Participants were 87 primarily European-American children (38 boys, 49 girls; mean age = 4.77 years) enrolled in early childhood classes in the northeastern United States. Children were given one minute to complete a 12-piece puzzle task in one of three background music conditions: music with lyrics, music without lyrics, and no music. The music selection was "You're Welcome" from the Disney movie "Moana." Results revealed that children who heard the music without lyrics completed more puzzle pieces than children in either the music with lyrics or no music condition. Background music without distracting lyrics may be beneficial and superior to background music with lyrics for young children's cognitive performance even when they are engaged independently in a nonverbal task.

Homogenized Finite Element Analysis on Effective Elastoplastic Mechanical Behaviors of Composite with Imperfect Interfaces

Directory of Open Access Journals (Sweden)

Wu-Gui Jiang

2014-12-01

Full Text Available A three-dimensional (3D representative volume element (RVE model was developed for analyzing effective mechanical behavior of fiber-reinforced ceramic matrix composites with imperfect interfaces. In the model, the fiber is assumed to be perfectly elastic until its tensile strength, and the ceramic material is modeled by an elasto-plastic Drucker-Prager constitutive law. The RVE model is then used to study the elastic properties and the tensile strength of composites with imperfect interfaces and validated through experiments. The imperfect interfaces between the fiber and the matrix are taken into account by introducing some cohesive contact surfaces. The influences of the interface on the elastic constants and the tensile strengths are examined through these interface models.

Knowledge formalization for vector data matching using belief theory

Directory of Open Access Journals (Sweden)

Ana-Maria Olteanu-Raimond

2015-06-01

Full Text Available Nowadays geographic vector data is produced both by public and private institutions using well defined specifications or crowdsourcing via Web 2.0 mapping portals. As a result, multiple representations of the same real world objects exist, without any links between these different representations. This becomes an issue when integration, updates, or multi-level analysis needs to be performed, as well as for data quality assessment. In this paper a multi-criteria data matching approach allowing the automatic definition of links between identical features is proposed. The originality of the approach is that the process is guided by an explicit representation and fusion of knowledge from various sources. Moreover the imperfection (imprecision, uncertainty, and incompleteness is explicitly modeled in the process. Belief theory is used to represent and fuse knowledge from different sources, to model imperfection, and make a decision. Experiments are reported on real data coming from different producers, having different scales and either representing relief (isolated points or road networks (linear data.

Experimental status of the E/ι puzzle

International Nuclear Information System (INIS)

Lanaro, A.

1996-11-01

Despite the prolonged experimental effort devoted to the spectroscopy of the E/ι mesons, and the intense theoretical debate around this subject, many puzzling issues still prevent from a full understanding of the true scenario. The advent of new and more precise experimental measurements motivates a review on this topic

Standards vs. labels with imperfect competition and asymmetric information

DEFF Research Database (Denmark)

Baltzer, Kenneth Thomas

2012-01-01

I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical differentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

Standards vs. labels with imperfect competition and asymmetric information

DEFF Research Database (Denmark)

Baltzer, Kenneth Thomas

I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical dierentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

Imperfect Tests and Natural Insurance Monopolies

OpenAIRE

Emons, Winand

1997-01-01

This paper considers a housing insurance market in which buildings have different damage probabilities. Insurers use imperfect tests to find out about buildings’ damage types. The insurance market is a natural monopoly. If more than one insurer is active, high risk house owners continue to apply to insurers until they are eventually assigned to a low-risk class. First we show that the natural insurance monopoly need not be sustainable. Then we show that in the equilibrium industry structure t...

Non-axisymmetric dynamic response of imperfectly bonded buried ...

African Journals Online (AJOL)

Using thin shell theory, the effect of shear deformation and rotary inertia is not considered. The pipeline is modeled as an infinite thin cylindrical shell imperfectly bonded to surrounding. A thin layer is assumed between the shell and the surrounding medium (soil) such that this layer possesses the properties of stiffness and ...

Investigations on the ultimate compressive strength of composite plates with geometrical imperfections

DEFF Research Database (Denmark)

Misirlis, K.; Downes, J.; Dow, R.S.

2009-01-01

with initial geometric imperfections. This paper presents the validation of finite element models against a series of plate tests that were performed within this framework and parametric studies that were carried out to identify the effects of geometric imperfections on the ultimate compressive strength......A series of studies has been performed within the MARSTRUCT Network of Excellence on Marine Structures in order to investigate the buckling response of glass fibre reinforced polymer plates. These studies include the fabrication, testing and finite element analysis of a large number of plates...

Synchronizing spatio-temporal chaos with imperfect models: A stochastic surface growth picture

International Nuclear Information System (INIS)

Pazó, Diego; López, Juan M.; Rodríguez, Miguel A.; Gallego, Rafael

2014-01-01

We study the synchronization of two spatially extended dynamical systems where the models have imperfections. We show that the synchronization error across space can be visualized as a rough surface governed by the Kardar-Parisi-Zhang equation with both upper and lower bounding walls corresponding to nonlinearities and model discrepancies, respectively. Two types of model imperfections are considered: parameter mismatch and unresolved fast scales, finding in both cases the same qualitative results. The consistency between different setups and systems indicates that the results are generic for a wide family of spatially extended systems

Study of the influence of imperfections on the dynamic stability of tanks

International Nuclear Information System (INIS)

Uras, R.A.; Liu, Wing Kam; Chen, Yi-Jung

1990-01-01

The influence of geometrical imperfections on the dynamic stability of liquid-filled shells under horizontal ground excitation is studied. Some basic concepts in the large deformation and large deformation thin shell theory are recalled. The work done by inertial and internal forces are given in the Gaussian surface coordinate system. A general imperfection pattern in the circumferential direction is introduced. The emphasis is particularly dedicated to the analysis of the geometrical stiffness term. Different patterns are studied to explain the occurrence of additional instability regions. 6 refs., 1 fig., 3 tabs

Nature's Greatest Puzzles

Energy Technology Data Exchange (ETDEWEB)

Quigg, Chris; /Fermilab

2005-02-01

It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit.

The Incomplete Glutathione Puzzle: Just Guessing at Numbers and Figures?

Science.gov (United States)

Deponte, Marcel

2017-11-20

Glutathione metabolism is comparable to a jigsaw puzzle with too many pieces. It is supposed to comprise (i) the reduction of disulfides, hydroperoxides, sulfenic acids, and nitrosothiols, (ii) the detoxification of aldehydes, xenobiotics, and heavy metals, and (iii) the synthesis of eicosanoids, steroids, and iron-sulfur clusters. In addition, glutathione affects oxidative protein folding and redox signaling. Here, I try to provide an overview on the relevance of glutathione-dependent pathways with an emphasis on quantitative data. Recent Advances: Intracellular redox measurements reveal that the cytosol, the nucleus, and mitochondria contain very little glutathione disulfide and that oxidative challenges are rapidly counterbalanced. Genetic approaches suggest that iron metabolism is the centerpiece of the glutathione puzzle in yeast. Furthermore, recent biochemical studies provide novel insights on glutathione transport processes and uncoupling mechanisms. Which parts of the glutathione puzzle are most relevant? Does this explain the high intracellular concentrations of reduced glutathione? How can iron-sulfur cluster biogenesis, oxidative protein folding, or redox signaling occur at high glutathione concentrations? Answers to these questions not only seem to depend on the organism, cell type, and subcellular compartment but also on different ideologies among researchers. A rational approach to compare the relevance of glutathione-dependent pathways is to combine genetic and quantitative kinetic data. However, there are still many missing pieces and too little is known about the compartment-specific repertoire and concentration of numerous metabolites, substrates, enzymes, and transporters as well as rate constants and enzyme kinetic patterns. Gathering this information might require the development of novel tools but is crucial to address potential kinetic competitions and to decipher uncoupling mechanisms to solve the glutathione puzzle. Antioxid. Redox Signal

The puzzle of the ultra-high energy cosmic rays

CERN Document Server

Tkachev, I I

2003-01-01

In early years the cosmic ray studies were ahead of accelerator research, starting from the discovery of positrons, through muons, to that of pions and strange particles. Today we are facing the situation that the puzzling saga of cosmic rays of the highest energies may again unfold in the discovery of new physics, now beyond the Standard Model; or it may bring to life an "extreme" astrophysics. After a short review of the Greisen-Zatsepin-Kuzmin puzzle, I discuss different models which were suggested for its resolution. Are there any hints pointing to the correct model? I argue that the small-scale clustering of arrival directions of cosmic rays gives a clue, and BL Lacs are the probable sources of the observed events. (58 refs).

Food puzzles for cats: Feeding for physical and emotional wellbeing.

Science.gov (United States)

Dantas, Leticia Ms; Delgado, Mikel M; Johnson, Ingrid; Buffington, Ca Tony

2016-09-01

Many pet cats are kept indoors for a variety of reasons (eg, safety, health, avoidance of wildlife predation) in conditions that are perhaps the least natural to them. Indoor housing has been associated with health issues, such as chronic lower urinary tract signs, and development of problem behaviors, which can cause weakening of the human-animal bond and lead to euthanasia of the cat. Environmental enrichment may mitigate the effects of these problems and one approach is to take advantage of cats' natural instinct to work for their food. In this article we aim to equip veterinary professionals with the tools to assist clients in the use of food puzzles for their cats as a way to support feline physical health and emotional wellbeing. We outline different types of food puzzles, and explain how to introduce them to cats and how to troubleshoot challenges with their use. The effect of food puzzles on cats is a relatively new area of study, so as well as reviewing the existing empirical evidence, we provide case studies from our veterinary and behavioral practices showing health and behavioral benefits resulting from their use. © The Author(s) 2016.

The Crossword Puzzle as a Teaching Tool.

Science.gov (United States)

Crossman, Edward K.

1983-01-01

In courses such as the history of psychology, it is necessary to learn a variety of relationships, events, and sequences, in addition to the task of having to pair certain key concepts with related names, e.g., phrenology--Hall. One tool useful in this type of learning is the crossword puzzle. (RM)

PENERAPAN JIGSAW PUZZLE COMPETITION DALAM PEMBELAJARAN KONTEKSTUAL UNTUK MENINGKATKAN MINAT DAN HASIL BELAJAR FISIKA SISWA SMP

Directory of Open Access Journals (Sweden)

D. Yulianti

2012-01-01

Full Text Available Untuk mengatasi kurangnya minat dan hasil belajar fisika siswa dilakukan penelitian melalui kegiatan pembelajaran fisikakontekstual berbantuan jigsaw puzzle competititon. Subjek penelitian ini adalah siswa kelas VII H SMP Negeri 18 Semarang.Penelitian ini telah dilakukan pembelajaran dengan pendekatan kontekstual berbantuan jigsaw puzzle competition. Hasilpenelitian menunjukkan bahwa pembelajaran kontekstual berbantuan jigsaw puzzle competition mampu meningkatan minat danhasil belajar siswa kelas VII H SMPNegeri 18 Semarang tahun pelajaran 2008/2009 secara signifikan. Agar lebih efektif sebaiknyadikembangkan pembelajaran kontekstual dengan metode lain agar diperoleh peningkatan minat dan hasil belajar Model ini perludiaplikasikan dalam pembelajaran fisika untuk materi yang lain. To overcome the problem of lack of students' interest as well as their achievements a Jigsaw Puzzle Competition in physicscontextual learning process was done. The students from VIIHclass of Junior High School 18 Semarang academic year 2008/2009were chosen as the subjects. The result of this research shows that contextual teaching and learning using Jigsaw PuzzleCompetition approach was not only increase the students' interest but also improve their achievements. In order to get moreeffective result, it is necessary to develop contextual teaching and learning by combining them with other method. Because of thegreat benefit of this model, it is necessary to apply this model to other physics learning concepts.Keywords: Jigsaw Puzzle Competition, contextual, interest;

Machine Imperfection Studies of the RAON Superconducting Linac

Science.gov (United States)

Jeon, D.; Jang, J.-H.; Jin, H.

2018-05-01

Studies of the machine imperfections in the RAON superconducting linac (SCL) that employs normal conducting (NC) quadrupoles were done to assess the tolerable error budgets of the machine imperfections that ensure operation of the beam. The studies show that the beam loss requirement is met even before the orbit correction and that the beam loss requirement is met even without the MHB (multi-harmonic buncher) and VE (velocity equalizer) thanks to the RAON's radio-frequency quadrupole (RFQ) design feature. For the low energy section of the linac (SCL3), a comparison is made between the two superconducting linac lattice types: one lattice that employs NC quadrupoles and the other that employs SC solenoids. The studies show that both lattices meet the beam loss requirement after the orbit correction. However, before the orbit correction, the lattice employing SC solenoids does not meet the beam loss requirement and can cause a significant beam loss, while the lattice employing NC quadrupoles meets the requirement. For the lattice employing SC solenoids, care must be taken during the beam commissioning.

Decision Making with Imperfect Decision Makers

CERN Document Server

Guy, Tatiana Valentine; Wolpert, David H

2012-01-01

Prescriptive Bayesian decision making has reached a high level of maturity and is well-supported algorithmically. However, experimental data shows that real decision makers choose such Bayes-optimal decisions surprisingly infrequently, often making decisions that are badly sub-optimal. So prevalent is such imperfect decision-making that it should be accepted as an inherent feature of real decision makers living within interacting societies. To date such societies have been investigated from an economic and gametheoretic perspective, and even to a degree from a physics perspective. However, lit

Pollution permits allocation and imperfect competition; Allocation de permis de pollution et concurrence imparfaite

Energy Technology Data Exchange (ETDEWEB)

Schwartz, S.

2004-12-15

The aim of this thesis is to highlight the imperfections on the permits markets and to analyze their consequences on markets' efficiency. More precisely, we try to identify the implications of the initial allocation of permits when such imperfections are present. We try to draw some conclusions for the regulator concerning the different forms of the permits' allocation. After having described and compared these forms, we define in which circumstances the initial allocation matters in terms of efficiency. Then, we study different forms of imperfections. First, we take into account the information asymmetry between firms and the regulator and we define an optimal mechanism to sell pollution permits. Then, we analyze a market power on a differentiated pollution permits market. At last, we study the exclusionary manipulation of pollution permits market. (author)

Security analysis on some experimental quantum key distribution systems with imperfect optical and electrical devices

Science.gov (United States)

Liang, Lin-Mei; Sun, Shi-Hai; Jiang, Mu-Sheng; Li, Chun-Yan

2014-10-01

In general, quantum key distribution (QKD) has been proved unconditionally secure for perfect devices due to quantum uncertainty principle, quantum noncloning theorem and quantum nondividing principle which means that a quantum cannot be divided further. However, the practical optical and electrical devices used in the system are imperfect, which can be exploited by the eavesdropper to partially or totally spy the secret key between the legitimate parties. In this article, we first briefly review the recent work on quantum hacking on some experimental QKD systems with respect to imperfect devices carried out internationally, then we will present our recent hacking works in details, including passive faraday mirror attack, partially random phase attack, wavelength-selected photon-number-splitting attack, frequency shift attack, and single-photon-detector attack. Those quantum attack reminds people to improve the security existed in practical QKD systems due to imperfect devices by simply adding countermeasure or adopting a totally different protocol such as measurement-device independent protocol to avoid quantum hacking on the imperfection of measurement devices [Lo, et al., Phys. Rev. Lett., 2012, 108: 130503].

Meson spectroscopy experiment at KEK - E/iota puzzle

International Nuclear Information System (INIS)

Tsuru, Tsuneaki

1985-01-01

Physics interests at the KEK (National Laboratory for High Energy Physics) are (1) search for exotic mesons such as glueballs (gg), meiktons (q anti q g) and multiquark states (q sup(2 - )q 2 ), (2) search for missing ordinary mesons (q anti q) and confirmation of unestablished mesons, and (3) new informations of quark contents of mesons, mixing angles of SU(3) singlet-octet and tests of conservations law. Special interest is in search for exotics such as glueballs and meiktons. (2) is a so-called meson spectroscopy experiment. This is important not only in itself but also in identifying newly discovered states as exotics because exotics have often same quantum numbers as ordinary mesons. Contents are the following: glueballs and E/iota puzzles, spectrometer system, experiments, performance of the spectrometer, physics outputs, E/iota puzzles and πI experiment, future plans. (Mori, K.)

The King and Prisoner Puzzle: A Way of Introducing the Components of Logical Structures

Science.gov (United States)

Roh, Kyeong Hah; Lee, Yong Hah; Tanner, Austin

2016-01-01

The purpose of this paper is to provide issues related to student understanding of logical components that arise when solving word problems. We designed a logic problem called the King and Prisoner Puzzle--a linguistically simple, yet logically challenging problem. In this paper, we describe various student solutions to the puzzle and discuss the…

On puzzles and non-puzzles in B→ππ,πK decays

International Nuclear Information System (INIS)

Fleischer, R.; Recksiegel, S.; Schwab, F.

2007-01-01

Recently, we have seen interesting progress in the exploration of CP violation in B d 0 →π + π - : the measurements of mixing-induced CP violation by the BaBar and Belle collaborations are now in good agreement with each other, whereas the picture of direct CP violation is still unclear. Using the branching ratio and direct CP asymmetry of B d 0 →π - K + , this situation can be clarified. We predict A CP dir (B d →π + π - )=-0.24±0.04, which favours the BaBar result, and we extract γ=(70.0 -4.3 +3.8 ) , which agrees with the unitarity triangle fits. Extending our analysis to other B→πK modes and B s 0 →K + K - with the help of the SU(3) flavour symmetry and plausible dynamical assumptions, we find that all observables with colour-suppressed electroweak penguin contributions are measured to be in excellent agreement with the standard model. As far as the ratios R c,n of the charged and neutral B→πK branching ratios are concerned, which are sizeably affected by electroweak penguin contributions, our standard-model predictions have almost unchanged central values but significantly reduced errors. Since the new data have moved quite a bit towards these results, the ''B→πK puzzle'' for the CP conserving quantities has been significantly reduced. However, the mixing-induced CP violation of B d 0 →π 0 K S does look puzzling; if confirmed by future measurements, this effect could be accommodated through a modified electroweak penguin sector with a large CP violating new-physics phase. Finally, we point out that the established difference between the direct CP asymmetries of B ± →π 0 K ± and B d →π -+ K ± appears to be generated by hadronic and not by new physics. (orig.)

Decodoku: Quantum error rorrection as a simple puzzle game

Science.gov (United States)

Wootton, James

To build quantum computers, we need to detect and manage any noise that occurs. This will be done using quantum error correction. At the hardware level, QEC is a multipartite system that stores information non-locally. Certain measurements are made which do not disturb the stored information, but which do allow signatures of errors to be detected. Then there is a software problem. How to take these measurement outcomes and determine: a) The errors that caused them, and (b) how to remove their effects. For qubit error correction, the algorithms required to do this are well known. For qudits, however, current methods are far from optimal. We consider the error correction problem of qubit surface codes. At the most basic level, this is a problem that can be expressed in terms of a grid of numbers. Using this fact, we take the inherent problem at the heart of quantum error correction, remove it from its quantum context, and presented in terms of simple grid based puzzle games. We have developed three versions of these puzzle games, focussing on different aspects of the required algorithms. These have been presented and iOS and Android apps, allowing the public to try their hand at developing good algorithms to solve the puzzles. For more information, see www.decodoku.com. Funding from the NCCR QSIT.

A puzzle form of a non-verbal intelligence test gives significantly higher performance measures in children with severe intellectual disability.

Science.gov (United States)

Bello, Katrina D; Goharpey, Nahal; Crewther, Sheila G; Crewther, David P

2008-08-01

Assessment of 'potential intellectual ability' of children with severe intellectual disability (ID) is limited, as current tests designed for normal children do not maintain their interest. Thus a manual puzzle version of the Raven's Coloured Progressive Matrices (RCPM) was devised to appeal to the attentional and sensory preferences and language limitations of children with ID. It was hypothesized that performance on the book and manual puzzle forms would not differ for typically developing children but that children with ID would perform better on the puzzle form. The first study assessed the validity of this puzzle form of the RCPM for 76 typically developing children in a test-retest crossover design, with a 3 week interval between tests. A second study tested performance and completion rate for the puzzle form compared to the book form in a sample of 164 children with ID. In the first study, no significant difference was found between performance on the puzzle and book forms in typically developing children, irrespective of the order of completion. The second study demonstrated a significantly higher performance and completion rate for the puzzle form compared to the book form in the ID population. Similar performance on book and puzzle forms of the RCPM by typically developing children suggests that both forms measure the same construct. These findings suggest that the puzzle form does not require greater cognitive ability but demands sensory-motor attention and limits distraction in children with severe ID. Thus, we suggest the puzzle form of the RCPM is a more reliable measure of the non-verbal mentation of children with severe ID than the book form.

Imperfection effects on the buckling of hydrostatically loaded cylinders

DEFF Research Database (Denmark)

Pinna, Rodney; Madsen, Søren

2015-01-01

imperfection sensitivity. Work on cylinders with other loading conditions, such as hydrostatic loading, is more limited. Similarly, there is limited work on cylinders with boundary conditions other than simply-supported ends. This paper looks at the case of cylinders under hydrostatic load, which is often...

Geometrical optics analysis of the structural imperfection of retroreflection corner cubes with a nonlinear conjugate gradient method.

Science.gov (United States)

Kim, Hwi; Min, Sung-Wook; Lee, Byoungho

2008-12-01

Geometrical optics analysis of the structural imperfection of retroreflection corner cubes is described. In the analysis, a geometrical optics model of six-beam reflection patterns generated by an imperfect retroreflection corner cube is developed, and its structural error extraction is formulated as a nonlinear optimization problem. The nonlinear conjugate gradient method is employed for solving the nonlinear optimization problem, and its detailed implementation is described. The proposed method of analysis is a mathematical basis for the nondestructive optical inspection of imperfectly fabricated retroreflection corner cubes.

Towards a security model for computational puzzle schemes

NARCIS (Netherlands)

Tang, Qiang; Jeckmans, Arjan

2011-01-01

In the literature, computational puzzle schemes have been considered as a useful tool for a number of applications, such as constructing timed cryptography, fighting junk emails, and protecting critical infrastructure from denial-of-service attacks. However, there is a lack of a general security

Dynamic imperfections and optimized feedback design in the Compact Linear Collider main linac

CERN Document Server

Eliasson, Peder

2008-01-01

The Compact Linear Collider (CLIC) main linac is sensitive to dynamic imperfections such as element jitter, injected beam jitter, and ground motion. These effects cause emittance growth that, in case of ground motion, has to be counteracted by a trajectory feedback system. The feedback system itself will, due to jitter effects and imperfect beam position monitors (BPMs), indirectly cause emittance growth. Fast and accurate simulations of both the direct and indirect effects are desirable, but due to the many elements of the CLIC main linac, simulations may become very time consuming. In this paper, an efficient way of simulating linear (or nearly linear) dynamic effects is described. The method is also shown to facilitate the analytic determination of emittance growth caused by the different dynamic imperfections while using a trajectory feedback system. Emittance growth expressions are derived for quadrupole, accelerating structure, and beam jitter, for ground motion, and for noise in the feedback BPMs. Fina...

Buckling And Postbuckling Of An Imperfect Plate Subjected To The Shear Load

Directory of Open Access Journals (Sweden)

Psotný Martin

2015-12-01

Full Text Available The stability analysis of an imperfect plate subjected to the shear load is presented. To solve this problem, a specialized computer program based on FEM has been created. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To obtain the nonlinear equilibrium paths, the Newton-Raphson iteration algorithm is used. Corresponding levels of the total potential energy are defined. Special attention is paid to the influence of imperfections on the post-critical buckling mode. Obtained results are compared with those gained using ANSYS system.

Mathematical History: Activities, Puzzles, Stories, and Games.

Science.gov (United States)

Mitchell, Merle

Based on the history of mathematics, these materials have been planned to enrich the teaching of mathematics in grades four, five, and six. Puzzles and games are based on stories about topics such as famous mathematicians, numerals of ancient peoples, and numerology. The sheets are arranged by grade level and are designed for easy duplication.…

(Mis)perception of sleep in insomnia: a puzzle and a resolution.

Science.gov (United States)

Harvey, Allison G; Tang, Nicole K Y

2012-01-01

Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not universal). Resolving this puzzle has clinical, theoretical, and public health importance. There are implications for assessment, definition, and treatment. Moreover, solving the puzzle creates an opportunity for real-world applications of theories from clinical, perceptual, and social psychology as well as neuroscience. Herein we evaluate 13 possible resolutions to the puzzle. Specifically, we consider the possible contribution, to misperception, of (1) features inherent to the context of sleep (e.g., darkness); (2) the definition of sleep onset, which may lack sensitivity for insomnia patients; (3) insomnia being an exaggerated sleep complaint; (4) psychological distress causing magnification; (5) a deficit in time estimation ability; (6) sleep being misperceived as wake; (7) worry and selective attention toward sleep-related threats; (8) a memory bias influenced by current symptoms and emotions, a confirmation bias/belief bias, or a recall bias linked to the intensity/recency of symptoms; (9) heightened physiological arousal; (10) elevated cortical arousal; (11) the presence of brief awakenings; (12) a fault in neuronal circuitry; and (13) there being 2 insomnia subtypes (one with and one without misperception). The best supported resolutions were misperception of sleep as wake, worry, and brief awakenings. A deficit in time estimation ability was not supported. We conclude by proposing several integrative solutions.

Imperfection Sensitivity of Nonlinear Vibration of Curved Single-Walled Carbon Nanotubes Based on Nonlocal Timoshenko Beam Theory

Directory of Open Access Journals (Sweden)

Iman Eshraghi

2016-09-01

Full Text Available Imperfection sensitivity of large amplitude vibration of curved single-walled carbon nanotubes (SWCNTs is considered in this study. The SWCNT is modeled as a Timoshenko nano-beam and its curved shape is included as an initial geometric imperfection term in the displacement field. Geometric nonlinearities of von Kármán type and nonlocal elasticity theory of Eringen are employed to derive governing equations of motion. Spatial discretization of governing equations and associated boundary conditions is performed using differential quadrature (DQ method and the corresponding nonlinear eigenvalue problem is iteratively solved. Effects of amplitude and location of the geometric imperfection, and the nonlocal small-scale parameter on the nonlinear frequency for various boundary conditions are investigated. The results show that the geometric imperfection and non-locality play a significant role in the nonlinear vibration characteristics of curved SWCNTs.

Spectroscopy of muonic atoms and the proton radius puzzle

Science.gov (United States)

Antognini, Aldo

2017-09-01

We have measured several 2 S -2 P transitions in muonic hydrogen (μp), muonic deuterium (μd) and muonic helium ions (μ3He, μ4He). From muonic hydrogen we extracted a proton charge radius 20 times more precise than obtained from electron-proton scattering and hydrogen high-precision laser spectroscopy but at a variance of 7 σ from these values. This discrepancy is nowadays referred to as the proton radius puzzle. New insight has been recently provided by the first determination of the deuteron charge radius from laser spectroscopy of μd. The status of the proton charge radius puzzle including the new insights obtained by μd spectroscopy will be discussed. Work supported by the Swiss National Science Foundation SNF-200021-165854 and the ERC CoG. #725039.

The Monotonicity Puzzle: An Experimental Investigation of Incentive Structures

Directory of Open Access Journals (Sweden)

Jeannette Brosig

2010-05-01

Full Text Available Non-monotone incentive structures, which - according to theory - are able to induce optimal behavior, are often regarded as empirically less relevant for labor relationships. We compare the performance of a theoretically optimal non-monotone contract with a monotone one under controlled laboratory conditions. Implementing some features relevant to real-world employment relationships, our paper demonstrates that, in fact, the frequency of income-maximizing decisions made by agents is higher under the monotone contract. Although this observed behavior does not change the superiority of the non-monotone contract for principals, they do not choose this contract type in a significant way. This is what we call the monotonicity puzzle. Detailed investigations of decisions provide a clue for solving the puzzle and a possible explanation for the popularity of monotone contracts.

Initially Imperfect MEMS Microplates Under Electrostatic Actuation: Theory and Experiment

KAUST Repository

Saghir, Shahid; Bellaredj, Mohammed Lamine Faycal; Younis, Mohammad I.

2016-01-01

Microplates are building blocks of many Micro-Electro-Mechanical Systems (MEMS). It is common for them to undergo imperfections due to residual stresses caused by the micro fabrication process. Such plates are essentially different from perfectly

Efficient logistic regression designs under an imperfect population identifier.

Science.gov (United States)

Albert, Paul S; Liu, Aiyi; Nansel, Tonja

2014-03-01

Motivated by actual study designs, this article considers efficient logistic regression designs where the population is identified with a binary test that is subject to diagnostic error. We consider the case where the imperfect test is obtained on all participants, while the gold standard test is measured on a small chosen subsample. Under maximum-likelihood estimation, we evaluate the optimal design in terms of sample selection as well as verification. We show that there may be substantial efficiency gains by choosing a small percentage of individuals who test negative on the imperfect test for inclusion in the sample (e.g., verifying 90% test-positive cases). We also show that a two-stage design may be a good practical alternative to a fixed design in some situations. Under optimal and nearly optimal designs, we compare maximum-likelihood and semi-parametric efficient estimators under correct and misspecified models with simulations. The methodology is illustrated with an analysis from a diabetes behavioral intervention trial. © 2013, The International Biometric Society.

Stability analysis of an open shallow cylindrical shell with imperfection under external pressure

Directory of Open Access Journals (Sweden)

Psotny Martin

2017-01-01

Full Text Available Elastic shallow generalized cylindrical shells of an open cross-section subjected to the various forms of external pressure are analysed in the paper numerically using the finite element method. Load - displacement paths are calculated for the perfect and imperfect geometry, respectively. Special attention is paid to the influence of initial geometric imperfection on the limit load level of fundamental equilibrium path of nonlinear analysis. ANSYS system was used for analysis, arc-length method was chosen for obtaining fundamental load - displacement path of solution.

The puzzle of neutron lifetime

International Nuclear Information System (INIS)

Paul, Stephan

2009-01-01

In this paper we review the role of the neutron lifetime and discuss the present status of measurements. In view of the large discrepancy observed by the two most precise individual measurements so far we describe the different techniques and point out the principle strengths and weaknesses. In particular we discuss the estimation of systematic uncertainties and its correlation to the statistical ones. In order to solve the present puzzle, many new experiments are either ongoing or being proposed. An overview on their possible contribution to this field will be given.

Evaluation Strategies in Financial Education: Evaluation with Imperfect Instruments

Science.gov (United States)

Robinson, Lauren; Dudensing, Rebekka; Granovsky, Nancy L.

2016-01-01

Program evaluation often suffers due to time constraints, imperfect instruments, incomplete data, and the need to report standardized metrics. This article about the evaluation process for the Wi$eUp financial education program showcases the difficulties inherent in evaluation and suggests best practices for assessing program effectiveness. We…

Production inventory policies for defective items with inspection errors, sales return, imperfect rework process and backorders

Science.gov (United States)

Jaggi, Chandra K.; Khanna, Aditi; Kishore, Aakanksha

2016-03-01

In order to sustain the challenges of maintaining good quality and perfect screening process, rework process becomes a rescue to compensate for the imperfections present in the production system. The proposed model attempts to explore the existing real-life situation with a more practical approach by incorporating the concept of imperfect rework as this occurs as an unavoidable problem to the firm due to irreparable disorders even in the reworked items. Hence, a production inventory model is formulated here to study the combined effect of imperfect quality items, faulty inspection process and imperfect rework process on the optimal production quantity and optimal backorder level. An analytical method is employed to maximize the expected total profit per unit time. Moreover, the results of several previous research articles namely Chiu et al (2006), Chiu et al (2005), Salameh and Hayek (2001), and classical EPQ with shortages are deduced as special cases. To demonstrate the applicability of the model, and to observe the effects of key parameters on the optimal replenishment policy, a numerical example along with a comprehensive sensitivity analysis has been presented. The pertinence of the model can be found in most of the manufacturing industries like textile, electronics, furniture, footwear, plastics etc. A production lot size model has been explored for defectives items with inspection errors and an imperfect rework process.

A cost effective degradation-based maintenance strategy under imperfect repair

International Nuclear Information System (INIS)

Wu, Fan; Niknam, Seyed A.; Kobza, John E.

2015-01-01

An optimization model is developed to minimize the total cost of imperfect degradation-based maintenance by determining an optimal interval of condition monitoring and the degradation level after imperfect preventive repairs. The decision model is based on a novel cost model that considers functional relationship between the expected degradation reduction and the cost of preventive repairs. The decision model is applied to simulated vibration signals with a variety of specifications of cost values and degradation model parameters. This study has initiated a new area for the research of cost effective maintenance strategies. The results clearly indicate the significance of the proposed model and the decision variables under the objective of minimal cost. For instance, the results indicate direct relationship between the optimal length of monitoring interval and the monitoring cost. However, longer monitoring interval increases the risk of failure, and therefore, more degradation reduction is needed. By increasing the slope of cumulative degradation, the cost effective strategy advocates taking more frequent monitoring. The optimal degradation level after each preventive repair is not so sensitive to the change in the degradation slope due to the uncertainty associated with degradation patterns. - Highlights: • Discuss the relationship of degradation reduction and maintenance cost. • Determine the optimal interval of condition monitoring with minimal cost. • Identify the optimal degradation level after imperfect preventive repairs. • Discuss the effects of change in the slope of cumulative degradation.

On a randomly imperfect spherical cap pressurized by a random ...

African Journals Online (AJOL)

On a randomly imperfect spherical cap pressurized by a random dynamic load. ... In this paper, we investigate a dynamical system in a random setting of dual ... characterization of the random process for determining the dynamic buckling load ...

Initially Imperfect MEMS Microplates Under Electrostatic Actuation: Theory and Experiment

KAUST Repository

Saghir, Shahid

2016-12-05

Microplates are building blocks of many Micro-Electro-Mechanical Systems (MEMS). It is common for them to undergo imperfections due to residual stresses caused by the micro fabrication process. Such plates are essentially different from perfectly flat plates and cannot be modeled using the governing equations of flat plates. In this article, we adopt the governing equations of imperfect plates employing the modified von-Karman strains. These equations then are used to develop a Reduced Order Model based on the Galerkin procedure to simulate the static and dynamic behavior of an electrostatically actuated microplate. Also, microplates made of silicon nitride are fabricated and tested. First, the static behaviour of the microplate is investigated when applying a static voltage Vdc. To study the dynamic behaviour we apply a harmonic voltage, Vac, superimposed to Vdc. Simulation results show good agreement with the experimentally measured responses.

Pedagogy Corner: The Architect's Puzzle

Science.gov (United States)

Lovitt, Charles

2017-01-01

Some years back, the author found the following problem in a spatial puzzle book: how many ways can you put four blocks together, face to face (with no vertical rotation symmetry)? He gave each student just four blocks and they collectively tried combinations to eventually agree on the answer of 15. He used to think it was a halfway decent task,…

The Problem of Controlling for Imperfectly Measured Confounders on Dissimilar Populations: A Database Simulation Study

Science.gov (United States)

Schonberger, Robert B; Gilbertsen, Todd; Dai, Feng

2013-01-01

Objective(s) Observational database research frequently relies on imperfect administrative markers to determine comorbid status, and it is difficult to infer to what extent the associated misclassification impacts validity in multivariable analyses. The effect that imperfect markers of disease will have on validity in situations where researchers attempt to match populations that have strong baseline health differences is underemphasized as a limitation in some otherwise high-quality observational studies. The present simulations were designed as a quantitative demonstration of the importance of this common and underappreciated issue. Design Two groups of Monte Carlo simulations were performed. The first demonstrated the degree to which controlling for a series of imperfect markers of disease between different populations taking 2 hypothetically harmless drugs would lead to spurious associations between drug assignment and mortality. The second Monte Carlo simulation applied this principle to a recent study in the field of anesthesiology that purported to show increased perioperative mortality in patients taking metoprolol versus atenolol. Setting/Participants/Interventions None. Measurements and Main Results Simulation 1: High type 1 error (ie, false positive findings of an independent association between drug assignment and mortality) was observed as sensitivity and specificity declined and as systematic differences in disease prevalence increased. Simulation 2: Propensity score matching across several imperfect markers was unlikely to eliminate important baseline health disparities in the referenced study. Conclusions In situations where large baseline health disparities exist between populations, matching on imperfect markers of disease may result in strong bias away from the null hypothesis. PMID:23962461

Using the Tower of Hanoi Puzzle to Infuse Your Mathematics Classroom with Computer Science Concepts

Science.gov (United States)

Marzocchi, Alison S.

2016-01-01

This article suggests that logic puzzles, such as the well-known Tower of Hanoi puzzle, can be used to introduce computer science concepts to mathematics students of all ages. Mathematics teachers introduce their students to computer science concepts that are enacted spontaneously and subconsciously throughout the solution to the Tower of Hanoi…

Topological derivatives of eigenvalues and neural networks in identification of imperfections

International Nuclear Information System (INIS)

Grzanek, M; Nowakowski, A; Sokolowski, J

2008-01-01

Numerical method for identification of imperfections is devised for elliptic spectral problems. The neural networks are employed for numerical solution. The topological derivatives of eigenvalues are used in the learning procedure of the neural networks. The topological derivatives of eigenvalues are determined by the methods of asymptotic analysis in singularly perturbed geometrical domains. The convergence of the numerical method in a probabilistic setting is analysed. The method is presented for the identification of small singular perturbations of the boundary of geometrical domain, however the framework is general and can be used for numerical solutions of inverse problems in the presence of small imperfections in the interior of the domain. Some numerical results are given for elliptic spectral problem in two spatial dimensions.

Features of state industrial policy under imperfect technological and institutional environment

Directory of Open Access Journals (Sweden)

Denisov Igor Vladimirovich

2011-07-01

Full Text Available For all countries with imperfect technology and the institutional environment (low culture and organization of production, high levels of corruption, the small middle class, not necessarily the execution of laws, etc., even such strong measures to support the economy like a direct financing of firms and territories, protectionism, stimulation of demand, etc. does not give significant effect. For Russia, which objectively have to be attributed to such countries, extremely relevant management system development, capable of overcoming difficulties, starting with the knees and the resistance of the imperfect (bad technological and institutional environment. Several theoretical solutions recently obtained through the development of the theory of economic-technological development of civilization, can create the mechanism and conditions of such a system.

Dentinogenesis imperfect a type II: A case report with 17 years of follow-up

Energy Technology Data Exchange (ETDEWEB)

Gama, Francisco Jose Reis; Correa, Isabella Sousa; Valerio, Claudia Scigliano; Fatima Ferreira, Emanuelle; Manzi, Flavio Ricardo [Pontifical Catholic University of Minas Gerais, Belo Horizonte (Brazil)

2017-06-15

Dentinogenesis imperfect a is a dominant autosomal hereditary disorder of dentin formation that affects the deciduous and permanent teeth. Its etiology is characterized by inadequate cell differentiation during odontogenesis. The clinical characteristics of dentinogenesis imperfect a are discolored teeth with a translucency that varies from gray to brown or amber. Radiographically, the teeth exhibit pulp obliteration, thin and short roots, bell-shaped crowns, and periapical bone rarefaction. The aim of this report was to present a case of dentinogenesis imperfect a type II that was followed up over a 17-year period. This report also presents scanning electron microscopy images of the enamel and dentin, showing that both were altered in the affected teeth. The disease characteristics and the treatments that were administered are reported in this study to guide dentists with respect to the need for early diagnosis and adequate follow-up to avoid major sequelae.

Dentinogenesis imperfect a type II: A case report with 17 years of follow-up

International Nuclear Information System (INIS)

Gama, Francisco Jose Reis; Correa, Isabella Sousa; Valerio, Claudia Scigliano; Fatima Ferreira, Emanuelle; Manzi, Flavio Ricardo

2017-01-01

Dentinogenesis imperfect a is a dominant autosomal hereditary disorder of dentin formation that affects the deciduous and permanent teeth. Its etiology is characterized by inadequate cell differentiation during odontogenesis. The clinical characteristics of dentinogenesis imperfect a are discolored teeth with a translucency that varies from gray to brown or amber. Radiographically, the teeth exhibit pulp obliteration, thin and short roots, bell-shaped crowns, and periapical bone rarefaction. The aim of this report was to present a case of dentinogenesis imperfect a type II that was followed up over a 17-year period. This report also presents scanning electron microscopy images of the enamel and dentin, showing that both were altered in the affected teeth. The disease characteristics and the treatments that were administered are reported in this study to guide dentists with respect to the need for early diagnosis and adequate follow-up to avoid major sequelae

Algorithm for the Evaluation of Imperfections in Auto Bodywork Using Profiles from a Retroreflective Image

Directory of Open Access Journals (Sweden)

Ramon Barber

2014-02-01

Full Text Available Nowadays the automobile industry is becoming more and more demanding as far as quality is concerned. Within the wide variety of processes in which this quality must be ensured, those regarding the squeezing of the auto bodywork are especially important due to the fact that the quality of the resulting product is tested manually by experts, leading to inaccuracies of all types. In this paper, an algorithm is proposed for the automated evaluation of the imperfections in the sheets of the bodywork after the squeezing process. The algorithm processes the profile signals from a retroreflective image and characterizes an imperfection. It is based on a convergence criterion that follows the line of the maximum gradient of the imperfection and gives its geometrical characteristics as a result: maximum gradient, length, width, and area.

Imperfect twinning: a clinical and ethical dilemma.

Science.gov (United States)

Denardin, Daniela; Telles, Jorge Alberto B; Betat, Rosilene da Silveira; Fell, Paulo Renato K; Cunha, André Campos da; Targa, Luciano Vieira; Zen, Paulo Ricardo G; Rosa, Rafael Fabiano M

2013-09-01

OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family.

Efficient Environmental Policy with Imperfect Compliance

Energy Technology Data Exchange (ETDEWEB)

Sandmo, A. [Norwegian School of Economics and Business Administration, Bergen (Norway)

2002-09-01

Discussions of efficient environmental policy tend to recommend taxes rather than quotas on grounds of efficiency; a uniform tax will equalize marginal abatement cost between polluters. When polluters' actions are imperfectly observable, the distinction between taxes and quotas becomes less clear. Taxes may be evaded by underreporting of emissions, while quota violations will not always be discovered. This paper explores the conditions under which the efficiency properties of taxes continue to hold even when evasion is possible, and the extent to which the fine for quota violations plays the same role as a tax on emissions with similar efficiency properties.

Theory of imperfect magnetosphere-ionosphere coupling

International Nuclear Information System (INIS)

Kan, J.R.; Lee, L.C.

1980-01-01

Atheory of magnetosphere-ionosphere coupling in the presence of field-aligned potential drops is formulated within the framework of magnetohydrodynamic equations. Our formulation allows the magnetosphere as well as the ionosphere to respond self-consistently to the parallel potential drop along auroral field lines. Equipotential contours are distorted into a V-shaped structure near the convection reversal boundary and S-shaped on the equatorward side, each gives rise to an inverted V precipitation band. The loading effect of the imperfect coupling results in a valley in the electric field profile which occurs equatorward of the convection reversal boundary

Coupled electromechanical model of an imperfect piezoelectric vibrating cylinder gyroscope

CSIR Research Space (South Africa)

Loveday, PW

1996-01-01

Full Text Available which is closed at one end with discrete piezoceramic actuation and sensing elements bonded close to the open end. The operation of the gyroscope and the effect of imperfections are briefly described. The model allows direct comparison with experimental...

Box-Cox transformation for resolving the Peelle's Pertinent Puzzle in a curve fitting

International Nuclear Information System (INIS)

Oh, S. Y.; Seo, C. G.

2004-01-01

Incorporating the Box-Cox transformation into a curve fitting is presented as one of methods for resolving an anomaly known as the Peelle's Pertinent Puzzle in the nuclear data community. The Box-Cox transformation is a strategy to make non-normal distribution data resemble normal distribution data. The proposed method consists of the following steps: transform the raw data to be fitted with the optimized Box-Cox transformation parameter, fit the transformed data using a conventional curve fitting tool, the least-squares method in this study, then inverse-transform the fitted results to the final estimates. Covariance matrices are correspondingly transformed and inverse-transformed with the aid of the law of error propagation. In addition to a sensible answer to the Puzzle, the proposed method resulted in reasonable estimates for a test evaluation with pseudo-experimental 6 Li(n, t) cross sections in several to 800 keV energy region, while the GMA code resulted in systematic underestimates that characterize the Puzzle. Meanwhile, it is observed that the present method and the Chiba-Smith method yield almost the same estimates for the test evaluation on 6 Li(n, t). Conceptually, however, two methods are very different from each other and further discussions are needed for a consensus on the issue of how to resolve the Puzzle. (authors)

A possible explanation of the 'exchange rate disconnect puzzle': A common solution to three major macroeconomic puzzles?

OpenAIRE

Horioka, Charles Yuji; Ford, Nicholas

2016-01-01

Meese and Rogoff (1983) and subsequent studies find that economic fundamentals are apparently not able to explain exchange rate movements, but we argue that this so-called "Exchange Rate Disconnect Puzzle" arose because researchers such as Meese and Rogoff (1983) did not use the right fundamentals and because they did not allow for the forward-looking nature of exchange rate determination. Further, because they apparently were not aware that financial markets by themselves could not equalise ...

Study on the Single Scattering of Elastic Waves by a Cylindrical Fiber with a Partially Imperfect Bonding Using the Collocation Point Method

Directory of Open Access Journals (Sweden)

Jun Zhang

2018-01-01

Full Text Available The single scattering of P- and SV-waves by a cylindrical fiber with a partially imperfect bonding to the surrounding matrix is investigated, which benefits the characterization of the behavior of elastic waves in composite materials. The imperfect interface is modelled by the spring model. To solve the corresponding single scattering problem, a collocation point (CP method is introduced. Based on this method, influence of various aspects of the imperfect interface on the scattering of P- and SV-waves is studied. Results indicate that (i the total scattering cross section (SCS is almost symmetric about the axis α=π/2 with respect to the location (α of the imperfect interface, (ii imperfect interfaces located at α=0 and α=π highly reduce the total SCS under a P-wave incidence and imperfect interfaces located at α=π/2 reduce the total SCS most significantly under SV-incidence, and (iii under a P-wave incidence the SCS has a high sensitivity to the bonding level of imperfect interfaces when α is small, while it becomes more sensitive to the bonding level when α is larger under SV-wave incidence.

Which is more effective for suppressing an infectious disease: imperfect vaccination or defense against contagion?

Science.gov (United States)

Kuga, Kazuki; Tanimoto, Jun

2018-02-01

We consider two imperfect ways to protect against an infectious disease such as influenza, namely vaccination giving only partial immunity and a defense against contagion such as wearing a mask. We build up a new analytic framework considering those two cases instead of perfect vaccination, conventionally assumed as a premise, with the assumption of an infinite and well-mixed population. Our framework also considers three different strategy-updating rules based on evolutionary game theory: conventional pairwise comparison with one randomly selected agent, another concept of pairwise comparison referring to a social average, and direct alternative selection not depending on the usual copying concept. We successfully obtain a phase diagram in which vaccination coverage at equilibrium can be compared when assuming the model of either imperfect vaccination or a defense against contagion. The obtained phase diagram reveals that a defense against contagion is marginally inferior to an imperfect vaccination as long as the same coefficient value is used. Highlights - We build a new analytical framework for a vaccination game combined with the susceptible-infected-recovered (SIR) model. - Our model can evaluate imperfect provisions such as vaccination giving only partial immunity and a defense against contagion. - We obtain a phase diagram with which to compare the quantitative effects of partial vaccination and a defense against contagion.

Equilibrium paths of an imperfect plate with respect to its aspect ratio

Science.gov (United States)

Psotny, Martin

2017-07-01

The stability analysis of a rectangular plate loaded in compression is presented, a specialized code based on FEM has been created. Special finite element with 48 degrees of freedom has been used for analysis. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To trace the complete nonlinear equilibrium paths, the Newton-Raphson iteration algorithm is used, load versus displacement control was changed during the calculation process. The peculiarities of the effects of the initial imperfections on the load-deflection paths are investigated with respect to aspect ratio of the plate. Special attention is paid to the influence of imperfections on the post-critical buckling mode.

How Rural Market Imperfections Shape the Relation Between Farm Size and Productivity

DEFF Research Database (Denmark)

Heltberg, Rasmus

The subject of this article is the alleged inverse relationship between farm size and productivity in developing countries. The recent controversy is reviewed, and a framework is provided to explain the inverse relationship based on plausible assumptions about imperfections in the markets for labor......, credit and land. On this basis testable hypotheses are derived. Using fram.level panel data from Pakistan, the framework is assessed by regressing output on operational fram size, size of owned holding, family size, tenurial status and irrigation status of the land. Household fixed effects are used...... to account for remaining unobserved heterogenity. It is concluded that an inverse relationship is present in Pakistan, and that the market imperfections framework performs well with the data...

Learning structural bioinformatics and evolution with a snake puzzle

Directory of Open Access Journals (Sweden)

Gonzalo S. Nido

2016-12-01

Full Text Available We propose here a working unit for teaching basic concepts of structural bioinformatics and evolution through the example of a wooden snake puzzle, strikingly similar to toy models widely used in the literature of protein folding. In our experience, developed at a Master’s course at the Universidad Autónoma de Madrid (Spain, the concreteness of this example helps to overcome difficulties caused by the interdisciplinary nature of this field and its high level of abstraction, in particular for students coming from traditional disciplines. The puzzle will allow us discussing a simple algorithm for finding folded solutions, through which we will introduce the concept of the configuration space and the contact matrix representation. This is a central tool for comparing protein structures, for studying simple models of protein energetics, and even for a qualitative discussion of folding kinetics, through the concept of the Contact Order. It also allows a simple representation of misfolded conformations and their free energy. These concepts will motivate evolutionary questions, which we will address by simulating a structurally constrained model of protein evolution, again modelled on the snake puzzle. In this way, we can discuss the analogy between evolutionary concepts and statistical mechanics that facilitates the understanding of both concepts. The proposed examples and literature are accessible, and we provide supplementary material (see ‘Data Availability’ to reproduce the numerical experiments. We also suggest possible directions to expand the unit. We hope that this work will further stimulate the adoption of games in teaching practice.

The height of Tennessee convicts: another piece of the "antebellum puzzle".

Science.gov (United States)

Sunder, Marco

2004-03-01

Average height of the free population in the United States born in the mid-1830s began to decline despite growing per capita incomes. Explanations for this "antebellum puzzle" revolve around a possibly deteriorating disease environment promoted by urban agglomeration and increases in the relative price of protein-rich foods. However, several groups were immune to the effect, including members of the middle class, whose income was high enough, and increased enough to overcome the adverse developments and maintain their nutritional status. Although at the opposite end of the social spectrum, the height of male slaves also increased, as it was in their owners' interest to raise their slaves' food allotments. The height of Tennessee convicts, analyzed in this article, also increased in the late-1830s, being the third exception to the "antebellum puzzle." Mid-19th century Tennessee was integrated into interstate commerce in cotton and tobacco and experienced considerable movement of people who would have brought with them diseases from elsewhere, hence, it would have been integrated into the US disease pool, and the fact that heights did not decline in the 1830s is therefore an indication that the antebellum puzzle cannot be explained exclusively by the spread of diseases. Yet, Tennessee's economy was quite different to that of the rest of the country. Although it did export live swine to the South, these exports did not increase during the antebellum decades. Hence, Tennessee remained self-sufficient in pork, and consumption of pork did not decline. Thus, the evidence presented here is consistent with the economic interpretation of the "antebellum puzzle": self-sufficiency in protein production protected even the members of the lower-classes of Tennessee from the negative externalities associated with the onset of industrialization.

Jigsaw puzzle metasurface for multiple functions: polarization conversion, anomalous reflection and diffusion.

Science.gov (United States)

Zhao, Yi; Cao, Xiangyu; Gao, Jun; Liu, Xiao; Li, Sijia

2016-05-16

We demonstrate a simple reconfigurable metasurface with multiple functions. Anisotropic tiles are investigated and manufactured as fundamental elements. Then, the tiles are combined in a certain sequence to construct a metasurface. Each of the tiles can be adjusted independently which is like a jigsaw puzzle and the whole metasurface can achieve diverse functions by different layouts. For demonstration purposes, we realize polarization conversion, anomalous reflection and diffusion by a jigsaw puzzle metasurface with 6 × 6 pieces of anisotropic tile. Simulated and measured results prove that our method offers a simple and effective strategy for metasurface design.

The puzzling assembly of the Milky Way halo – contributions from dwarf Spheroidals and globular clusters

Directory of Open Access Journals (Sweden)

Lépine S.

2012-02-01

Full Text Available While recent sky surveys have uncovered large numbers of ever fainter Milky Way satellites, their classification as star clusters, low-luminosity galaxies, or tidal overdensities remains often unclear. Likewise, their contributions to the build-up of the halo is yet debated. In this contribution we will discuss the current knowledge of the stellar populations and chemo-dynamics in these puzzling satellites, with a particular focus on dwarf spheroidal galaxies and the globular clusters in the outer Galactic halo. Also the question of whether some of the outermost halo objects are dynamically associated with the (Milky Way halo at all is addressed in terms of proper measurements in the remote Leo I and II dwarf galaxies.

An EPQ model with imperfect items using interval grey numbers

Directory of Open Access Journals (Sweden)

Erdal Aydemir

2015-01-01

Full Text Available The classic economic production quantity (EPQ model has been widely used to determine the optimal production quantity. However, the analysis for finding an EPQ model has many weaknesses which lead many researchers and practitioners to make extensions in several aspects on the original EPQ model. The basic assumption of EPQ model is that 100% of manufactured products are non-defective that is not valid for many production processes generally. The purpose of this paper is to develop an EPQ model with grey demand rate and cost values with maximum backorder level allowed with the good quality items in units under an imperfect production process. The imperfect items are considered to be low quality items which are sold to a particular purchaser at a lower price and, the others are reworked and scrapped. A mathematical model is developed and then an industrial example is presented on the wooden chipboard production process for illustration of the proposed model.

Influence of initial imperfections on ultimate strength of spherical shells

Directory of Open Access Journals (Sweden)

Chang-Li Yu

2017-09-01

Full Text Available Comprehensive consideration regarding influence mechanisms of initial imperfections on ultimate strength of spherical shells is taken to satisfy requirement of deep-sea structural design. The feasibility of innovative numerical procedure that combines welding simulation and non-linear buckling analysis is verified by a good agreement to experimental and theoretical results. Spherical shells with a series of wall thicknesses to radius ratios are studied. Residual stress and deformations from welding process are investigated separately. Variant influence mechanisms are discovered. Residual stress is demonstrated to be influential to stress field and buckling behavior but not to the ultimate strength. Deformations are proved to have a significant impact on ultimate strength. When central angles are less than critical value, concave magnitudes reduce ultimate strengths linearly. However, deformations with central angles above critical value are of much greater harm. Less imperfection susceptibility is found in spherical shells with larger wall thicknesses to radius ratios.

High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors

International Nuclear Information System (INIS)

Blaschke, David; Alvarez-Castillo, David E.

2016-01-01

We aim at contributing to the resolution of three of the fundamental puzzles related to the still unsolved problem of the structure of the dense core of compact stars (CS): (i) the hyperon puzzle: how to reconcile pulsar masses of 2 M ⊙ with the hyperon softening of the equation of state (EoS); (ii) the masquerade problem: modern EoS for cold, high density hadronic and quark matter are almost identical; and (iii) the reconfinement puzzle: what to do when after a deconfinement transition the hadronic EoS becomes favorable again? We show that taking into account the compositeness of baryons (by excluded volume and/or quark Pauli blocking) on the hadronic side and confining and stiffening effects on the quark matter side results in an early phase transition to quark matter with sufficient stiffening at high densities which removes all three present-day puzzles of CS interiors. Moreover, in this new class of EoS for hybrid CS falls the interesting case of a strong first order phase transition which results in the observable high mass twin star phenomenon, an astrophysical observation of a critical endpoint in the QCD phase diagram

Asset pricing puzzles explained by incomplete Brownian equilibria

DEFF Research Database (Denmark)

Christensen, Peter Ove; Larsen, Kasper

We examine a class of Brownian based models which produce tractable incomplete equilibria. The models are based on finitely many investors with heterogeneous exponential utilities over intermediate consumption who receive partially unspanned income. The investors can trade continuously on a finit...... markets. Consequently, our model can simultaneously help explaining the risk-free rate and equity premium puzzles....

Iterative Equalization and Interference Alignment for Multiuser MIMO HetNets with Imperfect CSI

Directory of Open Access Journals (Sweden)

Daniel Castanheira

2015-01-01

Full Text Available In this paper we consider a scenario, where several small-cells work under the same coverage area and spectrum of a macrocell. The signals stemming from the small-cell (macrocell users if not carefully dealt with will generate harmful interference into the macrocell (small-cell. To tackle this problem interference alignment and iterative equalization techniques are considered. By using IA all interference generated by the small-cell (macrocell users is aligned along a low dimensional subspace, at the macrocell (small-cells. This reduces considerably the amount of resources allocated, to enable the coexistence of the two systems. However, perfect IA requires the availability of error-free channel state information (CSI at the transmitters. Due to CSI errors one can have substantial performance degradation due to imperfect alignments. Since in this work the IA precoders are based on imperfect CSI, an efficient iterative space-frequency equalization is designed at the receiver side to cope with the residual aligned interference. The results demonstrate that iterative equalization is robust to imperfect CSI and removes efficiently the interference generated by the poorly aligned interference. Close to matched filter bound performance is achieved, with a very few number of iterations.

Yet another possible explanation of the solar-neutrino puzzle

International Nuclear Information System (INIS)

Kolb, E.W.; Turner, M.S.; Walker, T.P.

1986-01-01

Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m 2 2 -m 2 1 approx.=6x10 -5 eV 2 , and the mixing angle satisfies sin THETAsub(v)>0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0x10 -8 2 2 -m 2 1 )(sin 2 2THETAsub(v)/cos2THETAsub(v)) -8 eV 2 . Our solutions result in a much smaller flux of neutrinos from the p-p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p-p process that is about the same as standard solar models. (orig.)

May heavy neutrinos solve underground and cosmic-ray puzzles?

International Nuclear Information System (INIS)

Belotsky, K. M.; Fargion, D.; Khlopov, M. Yu.; Konoplich, R. V.

2008-01-01

Primordial heavy neutrinos of the fourth generation might explain different astrophysical puzzles. The simplest fourth-neutrino scenario is consistent with known fourth-neutrino physics, cosmic ray antimatter, cosmic gamma fluxes, and positive signals in underground detectors for a very narrow neutrino mass window (46–47 GeV). However, accounting for the constraint of underground experiment CDMS prohibits solution of cosmic-ray puzzles in this scenario. We have analyzed extended heavy-neutrino models related to the clumpiness of neutrino density, new interactions in heavy-neutrino annihilation, neutrino asymmetry, and neutrino decay. We found that, in these models, the cosmic-ray imprint may fit the positive underground signals in DAMA/Nal experiment in the entire mass range 46–70 GeV allowed from uncertainties of electroweak parameters, while satisfaction of the CDMS constraint reduces the mass range to around 50 GeV, where all data can come to consent in the framework of the considered hypothesis.

Status of particle physics solutions to the UHECR puzzle

International Nuclear Information System (INIS)

Kachelrieb, M.

2004-01-01

The status of solutions to the ultra-high energy cosmic ray (UHECR) puzzle that involve particle physics beyond the standard model is reviewed. Signatures and experimental constraints are discussed for most proposals such as the Z burst model and topological defects (both allowed only as sub-dominant contributions), supermassive dark matter (no positive evidence from its key signatures galactic anisotropy and photon dominance), strongly interacting neutrinos or new primaries (no viable models known), and violation of Lorentz invariance (viable). Lorentz invariance violation should be considered seriously as an explanation for the UHECR puzzle, if there is not a considerable fraction of photon primaries at the highest energies, correlations with sources at cosmological distance can be established, and the spectrum extends well beyond the GZK (Greisen-Zatsepin-Kuzmin) cutoff. If only the two first conditions are found to be true, and the UHECR spectrum is close to the one measured in the HiRes experiment, then bottom-up scenarios are a sufficient explanation for the data

May heavy neutrinos solve underground and cosmic-ray puzzles?

International Nuclear Information System (INIS)

Belotsky, K. M.; Fargion, D.; Khlopov, M. Yu.; Konoplich, R. V.

2008-01-01

Primordial heavy neutrinos of the fourth generation might explain different astrophysical puzzles. The simplest fourth-neutrino scenario is consistent with known fourth-neutrino physics, cosmic ray antimatter, cosmic gamma fluxes, and positive signals in underground detectors for a very narrow neutrino mass window (46-47 GeV). However, accounting for the constraint of underground experiment CDMS prohibits solution of cosmic-ray puzzles in this scenario. We have analyzed extended heavy-neutrino models related to the clumpiness of neutrino density, new interactions in heavy-neutrino annihilation, neutrino asymmetry, and neutrino decay. We found that, in these models, the cosmic-ray imprint may fit the positive underground signals in DAMA/Nal experiment in the entire mass range 46-70 GeV allowed from uncertainties of electroweak parameters, while satisfaction of the CDMS constraint reduces the mass range to around 50 GeV, where all data can come to consent in the framework of the considered hypothesis

Yet another possible explanation of the solar-neutrino puzzle

International Nuclear Information System (INIS)

Kolb, E.W.; Turner, M.S.; Walker, T.P.

1986-04-01

Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m 2 2 - m 1 2 approx. = 6 x 10 -5 eV 2 , and the mixing angle satisfies sin theta/sub v/ > 0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0 x 10 -8 2 2 - m 1 2 ) (sin 2 2theta/sub v//cos 2theta/sub v/) -8 eV 2 . Our solutions result in a much smaller flux of neutrinos from the p - p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p - process that is about the same as standard solar models

Using imperfect advance demand information in lost-sales inventory systems

NARCIS (Netherlands)

Topan, E.; Tan, T.; van Houtum, G.J.J.A.N.; Dekker, Rommert

Motivated by real-life applications, we consider an inventory system where it is possible to collect information about the quantity and timing of future demand in advance. However, this advance demand information (ADI) is imperfect because (i) it may turn out to be false, (ii) a time interval is

An Easy & Fun Way to Teach about How Science "Works": Popularizing Haack's Crossword-Puzzle Analogy

Science.gov (United States)

Pavlova, Iglika V.; Lewis, Kayla C.

2013-01-01

Science is a complex process, and we must not teach our students overly simplified versions of "the" scientific method. We propose that students can uncover the complex realities of scientific thinking by exploring the similarities and differences between solving the familiar crossword puzzles and scientific "puzzles."…

Quantum top secret. The solution of the quantum puzzle. Metamorphosis of a picture of world

International Nuclear Information System (INIS)

Wingert, M.

2008-01-01

Many physicists believe that because of unexplained causes, which must anyway be concerned with the quantum puzzle and the mysterious consciousness, it would be no more possible to understand the real structure of the reality - this subtle smiling of the nature, which irritates the physicists since 100 years and the disturbed the theoretical physics so much that they threw the towel. Since nature is considered as absurd, strange, and crazy - and quantum theory as very complicated. But in reality the basic experiments are of a touching simplicity, which seems only completely unintelligible in the picture of world of mechanics. For these experiments show that the concept of body of mechanics and the body conceptions of the thinking cannot at all match the structure of nature. If this is objectively taken notice of without doubting on the existence of a reality, the experiments show the real, unveiled face of the nature. Light and matter must then consist of fields, which can themselves divide by non-mechanical way, so with wholeness, comparable only with cell division and branching processes in biology. Either it is completely crazy - or the only logic interpretation, which hitherto only no physicist risked to think. For these experiments disprove the atom and elementary-particle hypothesis, the picture of world of mechanics, and also the quantum-mechanical interpretation - and indeed uniquely. This knowledge could break the Gordian knot, solve the quantum puzzle, and also give away the secret of the thinking spirit

Cryptographic Puzzles and Game Theory against DoS and DDoS attacks in Networks

DEFF Research Database (Denmark)

Mikalas, Antonis; Komninos, Nikos; Prasad, Neeli R.

2008-01-01

In this chapter, we present techniques to defeat Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks. In the _rst part, we describe client puzzle techniques that are based on the idea of computationally exhausting a malicious user when he attempts to launch an attack. In the ......In this chapter, we present techniques to defeat Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks. In the _rst part, we describe client puzzle techniques that are based on the idea of computationally exhausting a malicious user when he attempts to launch an attack....... In the second part we are introducing some basic principles of game theory and we discuss how game theoretical frameworks can protect computer networks. Finally, we show techniques that combine client puzzles with game theory in order to provide DoS and DDoS resilience....

Optimal tax progressivity in imperfect labour markets

DEFF Research Database (Denmark)

Sørensen, Peter Birch

1999-01-01

that there may be an optimal degree of tax progressivity where the marginal welfare gain from reduced involuntary unemployment is just offset by the marginal welfare loss from lower productivity. This paper sets up four different models of an imperfect labour market in order to identify the degree of tax......All modern labour market theories capable of explaining involuntary unemployment as an equilibrium phenomenon imply that increased income tax progressivity reduces unemployment, but they also imply that higher progressivity tends to reduce work effort and labour productivity. This suggests...

Chaos in an imperfectly premixed model combustor.

Science.gov (United States)

Kabiraj, Lipika; Saurabh, Aditya; Karimi, Nader; Sailor, Anna; Mastorakos, Epaminondas; Dowling, Ann P; Paschereit, Christian O

2015-02-01

This article reports nonlinear bifurcations observed in a laboratory scale, turbulent combustor operating under imperfectly premixed mode with global equivalence ratio as the control parameter. The results indicate that the dynamics of thermoacoustic instability correspond to quasi-periodic bifurcation to low-dimensional, deterministic chaos, a route that is common to a variety of dissipative nonlinear systems. The results support the recent identification of bifurcation scenarios in a laminar premixed flame combustor (Kabiraj et al., Chaos: Interdiscip. J. Nonlinear Sci. 22, 023129 (2012)) and extend the observation to a practically relevant combustor configuration.

Study of Weld Imperfections on Thin Aluminum Tubes According To ISO 10042

CERN Document Server

Rizkallah, Rabel

2014-01-01

The following report presents the work done as part of my summer student internship at CERN in the EN/MME group, and is divided into two parts. Part I of the report is a continuation of the work started previously by the student Quentin Drouhet, which aims at studying and classifying welding imperfections on various materials of small thicknesses. Drouhet worked on the welding imperfections found on thin Stainless Steel plates of thicknesses of 2 and 6 millimeters, welded using the GTAW (or TIG welding) process. My job was to conduct a similar study on thin Aluminum tubes welded using this same process. Part II of the report will introduce a new method for defect analysis that is still not available at CERN: the micro-tomographic testing

Padrão dos fluxos de capitais: teoria, evidência e puzzle

Directory of Open Access Journals (Sweden)

Aderbal Oliveira Damasceno

2014-04-01

Full Text Available Este trabalho desenvolve uma análise teórica e empírica sobre o padrão de longo prazo dos fluxos de capitais. Com uma amostra de 105 países e dados para o período 1980-2004, a metodologia econométrica abrange modelos para cross-section e para dados em painel. Os resultados apresentados sugerem: i incoerência entre as previsões do modelo neoclássico e o padrão observado dos fluxos de capitais, o que caracteriza o puzzle ; ii no âmbito da abordagem convencional, as explicações para o puzzle são diferenças de fundamentos entre países e imperfeições no mercado financeiro; iii não há evidências de que diferenças entre os países relativas ao ambiente institucional, estoque de capital humano, integração financeira, política macroeconòmica e desenvolvimento financeiro expliquem o puzzle. Considerando os resultados apresentados, esboça-se uma explicação alternativa de inspiração heterodoxa para o padrão dos fluxos de capitais.

A puzzle assembly strategy for fabrication of large engineered cartilage tissue constructs.

Science.gov (United States)

Nover, Adam B; Jones, Brian K; Yu, William T; Donovan, Daniel S; Podolnick, Jeremy D; Cook, James L; Ateshian, Gerard A; Hung, Clark T

2016-03-21

Engineering of large articular cartilage tissue constructs remains a challenge as tissue growth is limited by nutrient diffusion. Here, a novel strategy is investigated, generating large constructs through the assembly of individually cultured, interlocking, smaller puzzle-shaped subunits. These constructs can be engineered consistently with more desirable mechanical and biochemical properties than larger constructs (~4-fold greater Young׳s modulus). A failure testing technique was developed to evaluate the physiologic functionality of constructs, which were cultured as individual subunits for 28 days, then assembled and cultured for an additional 21-35 days. Assembled puzzle constructs withstood large deformations (40-50% compressive strain) prior to failure. Their ability to withstand physiologic loads may be enhanced by increases in subunit strength and assembled culture time. A nude mouse model was utilized to show biocompatibility and fusion of assembled puzzle pieces in vivo. Overall, the technique offers a novel, effective approach to scaling up engineered tissues and may be combined with other techniques and/or applied to the engineering of other tissues. Future studies will aim to optimize this system in an effort to engineer and integrate robust subunits to fill large defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Crossword Puzzles as a Learning Tool for Vocabulary Development

Science.gov (United States)

Orawiwatnakul, Wiwat

2013-01-01

Introduction: Since vocabulary is a key basis on which reading achievement depends, various vocabulary acquisition techniques have become pivotal. Among the many teaching approaches, traditional or otherwise, the use of crossword puzzles seems to offer potential and a solution for the problem of learning vocabulary. Method: This study was…

Action and puzzle video games prime different speed/accuracy tradeoffs.

Science.gov (United States)

Nelson, Rolf A; Strachan, Ian

2009-01-01

To understand the way in which video-game play affects subsequent perception and cognitive strategy, two experiments were performed in which participants played either a fast-action game or a puzzle-solving game. Before and after video-game play, participants performed a task in which both speed and accuracy were emphasized. In experiment 1 participants engaged in a location task in which they clicked a mouse on the spot where a target had appeared, and in experiment 2 they were asked to judge which of four shapes was most similar to a target shape. In both experiments, participants were much faster but less accurate after playing the action game, while they were slower but more accurate after playing the puzzle game. Results are discussed in terms of a taxonomy of video games by their cognitive and perceptual demands.

Children's Task Engagement during Challenging Puzzle Tasks

Science.gov (United States)

Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha

2017-01-01

We examined children's task engagement during a challenging puzzle task in the presence of their primary caregivers by using a representative sample of rural children from six high-poverty counties across two states. Weighted longitudinal confirmatory factor analysis and structural equation modeling were used to identify a task engagement factor…

Mankiw's Puzzle on Consumer Durables: A Misspecification

OpenAIRE

Tam Bang Vu

2005-01-01

Mankiw (1982) shows that consumer durables expenditures should follow a linear ARMA(1,1) process, but the data analyzed supports an AR(1) process instead; thus, a puzzle. In this paper, we employ a more general utility function than Mankiw's quadratic one. Further, the disturbance and depreciation rate are respecified, respectively, as multiplicative and stochastic. The analytical consequence is a nonlinear ARMA(infinity,1) process, which implies that the linear ARMA(1,1) is a misspecificatio...

Social Security and the Equity Premium Puzzle

OpenAIRE

Olovsson, Conny

2004-01-01

This paper shows that social security may be an important factor in explaining the equity premium puzzle. In the absence of shortselling constraints, the young shortsell bonds to the middle-aged and buy equity. Social security reduces the bond demand of the middle-aged, thereby restricting the possibilities of the young to finance their equity purchases. Their equity demand increases as does the average return to equity. Social security also increases the covariance between future consumption...

COMPARISON OF EIGENMODE-BASED AND RANDOM FIELD-BASED IMPERFECTION MODELING FOR THE STOCHASTIC BUCKLING ANALYSIS OF I-SECTION BEAM–COLUMNS

KAUST Repository

STAVREV, A.; STEFANOV, D.; SCHILLINGER, D.; RANK, E.

2013-01-01

The uncertainty of geometric imperfections in a series of nominally equal I-beams leads to a variability of corresponding buckling loads. Its analysis requires a stochastic imperfection model, which can be derived either by the simple variation

Characterization of imperfect bonding qualities of layered substrate using generalized leaky lamb waves

International Nuclear Information System (INIS)

Kwon, Sung Suk; Kim, Hak Joon; Song, Sung Jin

2006-01-01

Generalized Lamb waves that exist on layered substrates have been adopted as a tool for the bonding quality evaluation. A dispersion simulation by introducing an effective interface layer shows that all the dispersion curves for imperfect interfaces are in a form of concave curves and vary with the stiffness constants that can quantitatively represent the bonding quality. The characteristics of dispersion curves of TiN coating specimens with different wear conditions was experimentally determined by use of an ultrasonic backward radiation measurement technique. Results showed that the lowest velocity mode (Rayleigh-like) of the generalized Lamb waves are sensitively affected by the bonding quality and could be applied in the quantitative evaluation of imperfect bonding quality.

The RPA Atomization Energy Puzzle.

Science.gov (United States)

Ruzsinszky, Adrienn; Perdew, John P; Csonka, Gábor I

2010-01-12

There is current interest in the random phase approximation (RPA), a "fifth-rung" density functional for the exchange-correlation energy. RPA has full exact exchange and constructs the correlation with the help of the unoccupied Kohn-Sham orbitals. In many cases (uniform electron gas, jellium surface, and free atom), the correction to RPA is a short-ranged effect that is captured by a local spin density approximation (LSDA) or a generalized gradient approximation (GGA). Nonempirical density functionals for the correction to RPA were constructed earlier at the LSDA and GGA levels (RPA+), but they are constructed here at the fully nonlocal level (RPA++), using the van der Waals density functional (vdW-DF) of Langreth, Lundqvist, and collaborators. While they make important and helpful corrections to RPA total and ionization energies of free atoms, they correct the RPA atomization energies of molecules by only about 1 kcal/mol. Thus, it is puzzling that RPA atomization energies are, on average, about 10 kcal/mol lower than those of accurate values from experiment. We find here that a hybrid of 50% Perdew-Burke-Ernzerhof GGA with 50% RPA+ yields atomization energies much more accurate than either one does alone. This suggests a solution to the puzzle: While the proper correction to RPA is short-ranged in some systems, its contribution to the correlation hole can spread out in a molecule with multiple atomic centers, canceling part of the spread of the exact exchange hole (more so than in RPA or RPA+), making the true exchange-correlation hole more localized than in RPA or RPA+. This effect is not captured even by the vdW-DF nonlocality, but it requires the different kind of full nonlocality present in a hybrid functional.

Games and puzzles for English as a second language

CERN Document Server

Fremont, Victoria

2011-01-01

Students can hone their verbal and grammatical skills with this entertaining workbook. Search-a-words, crossword puzzles, anagrams, and other challenges build vocabulary and spelling skills. They also help students understand and identify idioms, irregular past tenses and participles, and other linguistic stumbling blocks. Perfect for individual study or as a course supplement.

On a randomly imperfect spherical cap pressurized by a random ...

African Journals Online (AJOL)

In this paper, we investigate a dynamical system in a random setting of dual randomness in space and time variables in which both the imperfection of the structure and the load function are considered random , each with a statistical zero-mean .The auto- covariance of the load is correlated as an exponentially decaying ...

Soft cooperative spectrum sensing performance under imperfect and non identical reporting channels

KAUST Repository

Ben Ghorbel, Mahdi; Nam, Haewoon; Alouini, Mohamed-Slim

2015-01-01

in cooperative spectrum sensing techniques assume perfect channels between the cooperating users, this paper studies the effect of imperfect channels when local users report their sensed information to the fusion center. Cooperative detection and false

Pulling Helices inside Bacteria: Imperfect Helices and Rings

Science.gov (United States)

Allard, Jun F.; Rutenberg, Andrew D.

2009-04-01

We study steady-state configurations of intrinsically-straight elastic filaments constrained within rod-shaped bacteria that have applied forces distributed along their length. Perfect steady-state helices result from axial or azimuthal forces applied at filament ends, however azimuthal forces are required for the small pitches observed for MreB filaments within bacteria. Helix-like configurations can result from distributed forces, including coexistence between rings and imperfect helices. Levels of expression and/or bundling of the polymeric protein could mediate this coexistence.

Exfoliation syndrome: assembling the puzzle pieces.

Science.gov (United States)

Pasquale, Louis R; Borrás, Terete; Fingert, John H; Wiggs, Janey L; Ritch, Robert

2016-09-01

To summarize various topics and the cutting edge approaches to refine XFS pathogenesis that were discussed at the 21st annual Glaucoma Foundation Think Tank meeting in New York City, Sept. 19-20, 2014. The highlights of three categories of talks on cutting edge research in the field were summarized. Exfoliation syndrome (XFS) is a systemic disorder with a substantial ocular burden, including high rates of cataract, cataract surgery complications, glaucoma and retinal vein occlusion. New information about XFS is akin to puzzle pieces that do not quite join together to reveal a clear picture regarding how exfoliation material (XFM) forms. Meeting participants concluded that it is unclear how the mild homocysteinemia seen in XFS might contribute to the disarrayed extracellular aggregates characteristic of this syndrome. Lysyl oxidase-like 1 (LOXL1) variants are unequivocally genetic risk factors for XFS but exactly how these variants contribute to the assembly of exfoliation material (XFM) remains unclear. Variants in a new genomic region, CACNA1A associated with XFS, may alter calcium concentrations at the cell surface and facilitate XFM formation but much more work is needed before we can place this new finding in proper context. It is hoped that various animal model and ex vivo systems will emerge that will allow for proper assembly of the puzzle pieces into a coherent picture of XFS pathogenesis. A clear understanding of XFS pathogenesis may lead to 'upstream solutions' to reduce the ocular morbidity produced by XFS. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Puzzling with potential : dynamic testing of analogical reasoning in children

NARCIS (Netherlands)

Stevenson, Claire Elisabeth

2012-01-01

Assessment procedures are frequent in children's school careers; however, measuring potential for learning has remained a puzzle. Dynamic testing is a method to assess cognitive potential that includes training in the assessment process. The goal of this thesis project was to develop a new dynamic

Influence of stochastic geometric imperfections on the load-carrying behaviour of thin-walled structures using constrained random fields

Science.gov (United States)

Lauterbach, S.; Fina, M.; Wagner, W.

2018-04-01

Since structural engineering requires highly developed and optimized structures, the thickness dependency is one of the most controversially debated topics. This paper deals with stability analysis of lightweight thin structures combined with arbitrary geometrical imperfections. Generally known design guidelines only consider imperfections for simple shapes and loading, whereas for complex structures the lower-bound design philosophy still holds. Herein, uncertainties are considered with an empirical knockdown factor representing a lower bound of existing measurements. To fully understand and predict expected bearable loads, numerical investigations are essential, including geometrical imperfections. These are implemented into a stand-alone program code with a stochastic approach to compute random fields as geometric imperfections that are applied to nodes of the finite element mesh of selected structural examples. The stochastic approach uses the Karhunen-Loève expansion for the random field discretization. For this approach, the so-called correlation length l_c controls the random field in a powerful way. This parameter has a major influence on the buckling shape, and also on the stability load. First, the impact of the correlation length is studied for simple structures. Second, since most structures for engineering devices are more complex and combined structures, these are intensively discussed with the focus on constrained random fields for e.g. flange-web-intersections. Specific constraints for those random fields are pointed out with regard to the finite element model. Further, geometrical imperfections vanish where the structure is supported.

The Simple Past Puzzle. A Study of Some Aspects of the Syntax and Semantics of Tense

Directory of Open Access Journals (Sweden)

Nino Gulli

2014-05-01

Full Text Available In this paper, I claim that the so-called present perfect puzzle is, in reality, a puzzle about the simple past. It is the latter, I argue, that shows a puzzling behavior, given that it can be used not only in definite contexts but also in seemingly indefinite ones. I employ the notions of time frame and specifiability to show how the obvious distinction between the two tenses in terms of temporal logic can be accounted for. I also propose that the past morpheme -ed be considered a kind of verb determiner which selects a temporal XP as a complement. Such complement can be (and usually is expressed either in the sentence or in the larger discourse; however, it can also remain implicit, or covert.

Simultaneous explanation of the RK and R (D (*)) puzzles

Science.gov (United States)

Bhattacharya, Bhubanjyoti; Datta, Alakabha; London, David; Shivashankara, Shanmuka

2015-03-01

At present, there are several hints of lepton flavor non-universality. The LHCb Collaboration has measured RK ≡ B (B+ →K+μ+μ-) / B (B+ →K+e+e-), and the BaBar Collaboration has measured R (D (*)) ≡ B (B bar →D (*) +τ-νbarτ) / B (B bar →D (*) +ℓ-νbarℓ) (ℓ = e , μ). In all cases, the experimental results differ from the standard model predictions by 2- 3 σ. Recently, an explanation of the RK puzzle was proposed in which new physics (NP) generates a neutral-current operator involving only third-generation particles. Now, assuming the scale of NP is much larger than the weak scale, this NP operator must be made invariant under the full SU (3)C × SU (2)L × U(1)Y gauge group. In this Letter, we note that, when this is done, a new charged-current operator can appear, and this can explain the R (D (*)) puzzle. A more precise measurement of the double ratio R (D) / R (D*) can rule out this model.

[Poisoning by exhaust gas of the imperfect combustion of natural gas: 22 cases study].

Science.gov (United States)

Dong, Li-Min; Zhao, Hai; Zhang, Ming-Chang; He, Meng

2014-10-01

To analyze the case characteristics of poisoning by exhaust gas of the imperfect combustion of natural gas and provide references for forensic identification and prevention of such accidents. Twenty-two cases of poisoning by exhaust gas of the imperfect combustion of natural gas in Minhang District during 2004 to 2013 were collected. Some aspects such as general conditions of deaths, incidence time, weather, field investigation, and autopsy were retrospectively analyzed. In the 22 cases, there were 15 males and 16 females. The age range was between 2 and 82 years old. The major occurring time was in January or February (8 cases in each) and the cases almost occurred in small area room (21 cases). There was wide crack next to the exhaust port when the gas water heater was been used in all cases. There are more prone to occurrence of exhaust gas poisoning of imperfect combustion of natural gas in small area room with a ventilation window near the exhaust port of gas water heated. It shows that the scene of combustion exhaust gas poisoning should be more concerned in the cold season.

Importance sampling with imperfect cloning for the computation of generalized Lyapunov exponents

Science.gov (United States)

Anteneodo, Celia; Camargo, Sabrina; Vallejos, Raúl O.

2017-12-01

We revisit the numerical calculation of generalized Lyapunov exponents, L (q ) , in deterministic dynamical systems. The standard method consists of adding noise to the dynamics in order to use importance sampling algorithms. Then L (q ) is obtained by taking the limit noise-amplitude → 0 after the calculation. We focus on a particular method that involves periodic cloning and pruning of a set of trajectories. However, instead of considering a noisy dynamics, we implement an imperfect (noisy) cloning. This alternative method is compared with the standard one and, when possible, with analytical results. As a workbench we use the asymmetric tent map, the standard map, and a system of coupled symplectic maps. The general conclusion of this study is that the imperfect-cloning method performs as well as the standard one, with the advantage of preserving the deterministic dynamics.

Simulations to investigate the eect of circuit imperfections on the slow extraction process

CERN Document Server

Van De Pontseele, Wouter

2016-01-01

The Super Proton Synchrotron (SPS) is a 400 GeV proton accelerator at CERN. Its main purpose is the last step in pre-acceleration of particles before injecting them into the Large Hadron Collider. Besides that, it is used for experiments directly connected to the SPS. For these xed target experiments, a steady slow extraction of the SPS beam is necessary over thousands of turns. The SPS slow extraction process makes use of the third-integer resonance in combination with an electrostatic septum. The stability of the extracted intensity and the losses at the septum are in uenced by the imperfections of the current circuit that drives the SPS quadrupoles. This report summarizes the studies that were carried out with MAD-X to simulate these imperfections.

The puzzling unsolved mysteries of liquid water: Some recent progress

Science.gov (United States)

Stanley, H. E.; Kumar, P.; Xu, L.; Yan, Z.; Mazza, M. G.; Buldyrev, S. V.; Chen, S.-H.; Mallamace, F.

2007-12-01

Water is perhaps the most ubiquitous, and the most essential, of any molecule on earth. Indeed, it defies the imagination of even the most creative science fiction writer to picture what life would be like without water. Despite decades of research, however, water's puzzling properties are not understood and 63 anomalies that distinguish water from other liquids remain unsolved. We introduce some of these unsolved mysteries, and demonstrate recent progress in solving them. We present evidence from experiments and computer simulations supporting the hypothesis that water displays a special transition point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell). The general idea is that when the liquid is near this “tipping point,” it suddenly separates into two distinct liquid phases. This concept of a new critical point is finding application to other liquids as well as water, such as silicon and silica. We also discuss related puzzles, such as the mysterious behavior of water near a protein.

Remaining useful life prediction of degrading systems subjected to imperfect maintenance: Application to draught fans

Science.gov (United States)

Wang, Zhao-Qiang; Hu, Chang-Hua; Si, Xiao-Sheng; Zio, Enrico

2018-02-01

Current degradation modeling and remaining useful life prediction studies share a common assumption that the degrading systems are not maintained or maintained perfectly (i.e., to an as-good-as new state). This paper concerns the issues of how to model the degradation process and predict the remaining useful life of degrading systems subjected to imperfect maintenance activities, which can restore the health condition of a degrading system to any degradation level between as-good-as new and as-bad-as old. Toward this end, a nonlinear model driven by Wiener process is first proposed to characterize the degradation trajectory of the degrading system subjected to imperfect maintenance, where negative jumps are incorporated to quantify the influence of imperfect maintenance activities on the system's degradation. Then, the probability density function of the remaining useful life is derived analytically by a space-scale transformation, i.e., transforming the constructed degradation model with negative jumps crossing a constant threshold level to a Wiener process model crossing a random threshold level. To implement the proposed method, unknown parameters in the degradation model are estimated by the maximum likelihood estimation method. Finally, the proposed degradation modeling and remaining useful life prediction method are applied to a practical case of draught fans belonging to a kind of mechanical systems from steel mills. The results reveal that, for a degrading system subjected to imperfect maintenance, our proposed method can obtain more accurate remaining useful life predictions than those of the benchmark model in literature.

Modeling Real Exchange Rate Persistence in Chile

Directory of Open Access Journals (Sweden)

Leonardo Salazar

2017-07-01

Full Text Available The long and persistent swings in the real exchange rate have for a long time puzzled economists. Recent models built on imperfect knowledge economics seem to provide a theoretical explanation for this persistence. Empirical results, based on a cointegrated vector autoregressive (CVAR model, provide evidence of error-increasing behavior in prices and interest rates, which is consistent with the persistence observed in the data. The movements in the real exchange rate are compensated by movements in the interest rate spread, which restores the equilibrium in the product market when the real exchange rate moves away from its long-run benchmark value. Fluctuations in the copper price also explain the deviations of the real exchange rate from its long-run equilibrium value.

Economic analysis of e-waste market under imperfect information

OpenAIRE

Prudence Dato

2015-01-01

Despite international regulations that prohibit the trans-boundary movement of electronic and electric waste (e-waste), non-reusable e-waste is often illegally mixed with reusable e-waste and results in being sent to developing countries. As developing countries are not well prepared to properly manage e-waste, this illegal trade has important negative externalities, and creates ‘environmental injustice’. The two main information problems on the e-waste market are imperfect monitoring and imp...

Hybrid Charmonium and the p-n Puzzle

International Nuclear Information System (INIS)

Kisslinger, L.S.; Parno, D.; Riordan, S.

2008-01-01

Using the method of QCD sum rules, we estimate the energy of the lowest hybrid charmonium state, and find it to be at the energy of the Ψ (2S) state, about 600 MeV above the J/Ψ(1S) state. Since our solution is not consistent with a pure hybrid at this energy, we conclude that the Ψ (2S) state is probably an admixed cc - and hybrid cc - g state. From this conjecture, we find a possible explanation of the famous ρ-p puzzle.

Tiny bubbles challenge giant turbines: Three Gorges puzzle.

Science.gov (United States)

Li, Shengcai

2015-10-06

Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element 'draft-tube' that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700-1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences.

Solving the BM Camelopardalis puzzle

Science.gov (United States)

Teke, Mathias; Busby, Michael R.; Hall, Douglas S.

1989-01-01

BM Camelopardalis (=12 Cam) is a chromospherically active binary star with a relatively large orbital eccentricity. Systems with large eccentricities usually rotate pseudosynchronously. However, BM Cam has been a puzzle since its observed rotation rate is virtually equal to its orbital period indicating synchronization. All available photometry data for BM Cam have been collected and analyzed. Two models of modulated ellipticity effect are proposed, one based on equilibrium tidal deformation of the primary star and the other on a dynamical tidal effect. When the starspot variability is removed from the data, the dynamical tidal model was the better approximation to the real physical situation. The analysis indicates that BM Cam is not rotating pseudosynchronously but rotating in virtual synchronism after all.

Public knowledge and common secrets. Secrecy and its limits in the early modern Netherlands

NARCIS (Netherlands)

Davids, C.A.

2005-01-01

Openness of knowledge was in the Dutch Republic no more a natural state of affairs than in other parts of Europe at the time, but it became dominant there at an earlier date than elsewhere. This puzzling phenomenon is the subject of this essay. The article shows that tendencies to secrecy in crafts

Well-Defined Cyclic Triblock Terpolymers: A Missing Piece of the Morphology Puzzle

KAUST Repository

Polymeropoulos, George; Bilalis, Panayiotis; Hadjichristidis, Nikolaos

2016-01-01

Two well-defined cyclic triblock terpolymers, missing pieces of the terpolymer morphology puzzle, consisting of poly(isoprene), polystyrene, and poly(2-vinylpyridine), were synthesized by combining the Glaser coupling reaction with anionic

Understanding the Puzzling Risk-Return Relationship for Housing

OpenAIRE

Lu Han

2013-01-01

Standard theory predicts a positive relationship between risk and return, yet recent data show that housing returns vary positively with risk in some markets but negatively in others. This paper rationalizes these cross-market differences in the risk-return relationship for housing, and in so doing, explains the puzzling negative relationship. The paper shows that when the current house provides a hedge against the risk associated with the future housing consumption, households are willing to...

Solar Twins and the Barium Puzzle

International Nuclear Information System (INIS)

Reddy, Arumalla B. S.; Lambert, David L.

2017-01-01

Several abundance analyses of Galactic open clusters (OCs) have shown a tendency for Ba but not for other heavy elements (La−Sm) to increase sharply with decreasing age such that Ba was claimed to reach [Ba/Fe] ≃ +0.6 in the youngest clusters (ages < 100 Myr) rising from [Ba/Fe] = 0.00 dex in solar-age clusters. Within the formulation of the s -process, the difficulty to replicate higher Ba abundance and normal La−Sm abundances in young clusters is known as the barium puzzle. Here, we investigate the barium puzzle using extremely high-resolution and high signal-to-noise spectra of 24 solar twins and measured the heavy elements Ba, La, Ce, Nd, and Sm with a precision of 0.03 dex. We demonstrate that the enhanced Ba ii relative to La−Sm seen among solar twins, stellar associations, and OCs at young ages (<100 Myr) is unrelated to aspects of stellar nucleosynthesis but has resulted from overestimation of Ba by standard methods of LTE abundance analysis in which the microturbulence derived from the Fe lines formed deep in the photosphere is insufficient to represent the true line broadening imposed on Ba ii lines by the upper photospheric layers from where the Ba ii lines emerge. Because the young stars have relatively active photospheres, Ba overabundances most likely result from the adoption of a too low value of microturbulence in the spectrum synthesis of the strong Ba ii lines but the change of microturbulence in the upper photosphere has only a minor affect on La−Sm abundances measured from the weak lines.

Solar Twins and the Barium Puzzle

Energy Technology Data Exchange (ETDEWEB)

Reddy, Arumalla B. S.; Lambert, David L., E-mail: bala@astro.as.utexas.edu [W.J. McDonald Observatory and Department of Astronomy, The University of Texas at Austin, Austin, TX 78712-1205 (United States)

2017-08-20

Several abundance analyses of Galactic open clusters (OCs) have shown a tendency for Ba but not for other heavy elements (La−Sm) to increase sharply with decreasing age such that Ba was claimed to reach [Ba/Fe] ≃ +0.6 in the youngest clusters (ages < 100 Myr) rising from [Ba/Fe] = 0.00 dex in solar-age clusters. Within the formulation of the s -process, the difficulty to replicate higher Ba abundance and normal La−Sm abundances in young clusters is known as the barium puzzle. Here, we investigate the barium puzzle using extremely high-resolution and high signal-to-noise spectra of 24 solar twins and measured the heavy elements Ba, La, Ce, Nd, and Sm with a precision of 0.03 dex. We demonstrate that the enhanced Ba ii relative to La−Sm seen among solar twins, stellar associations, and OCs at young ages (<100 Myr) is unrelated to aspects of stellar nucleosynthesis but has resulted from overestimation of Ba by standard methods of LTE abundance analysis in which the microturbulence derived from the Fe lines formed deep in the photosphere is insufficient to represent the true line broadening imposed on Ba ii lines by the upper photospheric layers from where the Ba ii lines emerge. Because the young stars have relatively active photospheres, Ba overabundances most likely result from the adoption of a too low value of microturbulence in the spectrum synthesis of the strong Ba ii lines but the change of microturbulence in the upper photosphere has only a minor affect on La−Sm abundances measured from the weak lines.

Automated knowledge-base refinement

Science.gov (United States)

Mooney, Raymond J.

1994-01-01

Over the last several years, we have developed several systems for automatically refining incomplete and incorrect knowledge bases. These systems are given an imperfect rule base and a set of training examples and minimally modify the knowledge base to make it consistent with the examples. One of our most recent systems, FORTE, revises first-order Horn-clause knowledge bases. This system can be viewed as automatically debugging Prolog programs based on examples of correct and incorrect I/O pairs. In fact, we have already used the system to debug simple Prolog programs written by students in a programming language course. FORTE has also been used to automatically induce and revise qualitative models of several continuous dynamic devices from qualitative behavior traces. For example, it has been used to induce and revise a qualitative model of a portion of the Reaction Control System (RCS) of the NASA Space Shuttle. By fitting a correct model of this portion of the RCS to simulated qualitative data from a faulty system, FORTE was also able to correctly diagnose simple faults in this system.

Graph-based stochastic control with constraints: A unified approach with perfect and imperfect measurements

KAUST Repository

Agha-mohammadi, Ali-akbar

2013-06-01

This paper is concerned with the problem of stochastic optimal control (possibly with imperfect measurements) in the presence of constraints. We propose a computationally tractable framework to address this problem. The method lends itself to sampling-based methods where we construct a graph in the state space of the problem, on which a Dynamic Programming (DP) is solved and a closed-loop feedback policy is computed. The constraints are seamlessly incorporated to the control policy selection by including their effect on the transition probabilities of the graph edges. We present a unified framework that is applicable both in the state space (with perfect measurements) and in the information space (with imperfect measurements).

The Potential of Crossword Puzzles in Aiding English Language Learners

Science.gov (United States)

Merkel, Warren

2016-01-01

In an academic environment, teachers utilize crossword puzzles to help students learn or remember terminology. Outside the classroom, typically in daily newspapers, crosswords aid in vocabulary development, used as a learning tool, a leisure activity, or both. However, both the content and the grid structure of the crosswords in these two…

Desain Pembelajaran Bangun Datar Menggunakan Fable “Dog Catches Cat” And Puzzle Tangram Di Kelas II SD

Directory of Open Access Journals (Sweden)

Lisnani Lisnani

2013-06-01

Full Text Available Tujuan penelitian ini adalah mengembangkan kemampuan berpikir kreatif matematis siswa dalam pengenalan dan pengelompokkan bangun datar melalui fable “dog catches cat”, puzzle tangram, dan kreasi origami. Metode yang digunakan adalah design research terdiri dari tiga tahap, yaitu: preliminary, design experiment (pilot experiment dan teaching experiment, dan analysis retrospective.  Penelitian ini mengembangkan hasil pembelajaran tentang bangun datar melalui serangkaian aktivitas, prosedur, dan strategi bagi siswa dalam menemukan kemampuan berpikir kreatif melalui Pendekatan Pendidikan Matematika Realistik Indonesia (PMRI melalui konteks tangram melalui fable “dog catches cat”. Puzzle tangram, dan kreasi origami menjadi starting point materi pengenalan dan pengelompokkan bangun datar. Hasil dari penelitian ini berupa learning trajectory pada masing-masing aktivitas yaitu: 1 Aktivitas 1, siswa mengenal berbagai bentuk bangun datar melalui penggunaan fable. 2 Aktivitas 2, siswa mampu menyebutkan dan mengelompokkan berbagai bangun datar melalui puzzle tangram. 3 Aktivitas 3, membentuk dan mengelompokkan bangun datar dan terbentuk suatu kreasi baru berupa kucing, anjing, dan lainnya.The purpose of this research is to develop mathematical creative thinking abilities and grouping students in the introduction of a flat wake through the fable “dog catches paint " , tangram puzzles, and origami creations. The method used is the research design consists of three stages: preliminary, design of experiments (pilot experiments and teaching experiments, and a retrospective analysis. This study develops learning outcomes on a flat wake through a series of activities, procedures, and strategies for students in finding creative thinking abilities through Realistic Mathematics Education Approach Indonesia (PMRI through tangram context through fable “dog catches the paint “. Tangram puzzles, and origami creations become the starting point and the

Shear viscosity and imperfect fluidity in bosonic and fermionic superfluids

Science.gov (United States)

Boyack, Rufus; Guo, Hao; Levin, K.

2014-12-01

In this paper we address the ratio of the shear viscosity to entropy density η /s in bosonic and fermionic superfluids. A small η /s is associated with nearly perfect fluidity, and more general measures of the fluidity perfection/imperfection are of wide interest to a number of communities. We use a Kubo approach to concretely address this ratio via low-temperature transport associated with the quasiparticles. Our analysis for bosonic superfluids utilizes the framework of the one-loop Bogoliubov approximation, whereas for fermionic superfluids we apply BCS theory and its BCS-BEC extension. Interestingly, we find that the transport properties of strict BCS and Bogoliubov superfluids have very similar structures, albeit with different quasiparticle dispersion relations. While there is a dramatic contrast between the power law and exponential temperature dependence for η alone, the ratio η /s for both systems is more similar. Specifically, we find the same linear dependence (on the ratio of temperature T to inverse lifetime γ (T ) ) with η /s ∝T /γ (T ) , corresponding to imperfect fluidity. By contrast, near the unitary limit of BCS-BEC superfluids a very different behavior results, which is more consistent with near-perfect fluidity.

Efficient growth of complex graph states via imperfect path erasure

International Nuclear Information System (INIS)

Campbell, Earl T; Fitzsimons, Joseph; Benjamin, Simon C; Kok, Pieter

2007-01-01

Given a suitably large and well connected (complex) graph state, any quantum algorithm can be implemented purely through local measurements on the individual qubits. Measurements can also be used to create the graph state: path erasure techniques allow one to entangle multiple qubits by determining only global properties of the qubits. Here, this powerful approach is extended by demonstrating that even imperfect path erasure can produce the required graph states with high efficiency. By characterizing the degree of error in each path erasure attempt, one can subsume the resulting imperfect entanglement into an extended graph state formalism. The subsequent growth of the improper graph state can be guided, through a series of strategic decisions, in such a way as to bound the growth of the error and eventually yield a high-fidelity graph state. As an implementation of these techniques, we develop an analytic model for atom (or atom-like) qubits in mismatched cavities, under the double-heralding entanglement procedure of Barrett and Kok (2005 Phys. Rev. A 71 060310). Compared to straightforward post-selection techniques our protocol offers a dramatic improvement in growing complex high-fidelity graph states

Two-Echelon Inventory Optimization for Imperfect Production System under Quality Competition Environment

Directory of Open Access Journals (Sweden)

Xinfeng Lai

2015-01-01

Full Text Available This paper develops two integrated optimization models of two-echelon inventory for imperfect production system under quality competition environment, in which the vendor’s production process is assumed to be imperfect, and JIT delivery policy is implemented to ship product from the vendor to the buyer. In the first model, product defect rate is fixed, and, in the second model, quality improvement investment is function of defect rate. The optimal policies of ordering quantity of buyer and shipment from vendor to buyer are obtained to minimize the expected annual total cost of vendor and buyer. Numerical examples are used to demonstrate the effectiveness and feasibility of the models. Sensitivity analysis is taken to analyze the impact of demand, production rate, and defect rate on the solution. Implications are highlighted in that both the vendor and the buyer can benefit from the vendor’s investing in quality improvement.

Benefits of Imperfect Conflict Resolution Advisory Aids for Future Air Traffic Control.

Science.gov (United States)

Trapsilawati, Fitri; Wickens, Christopher D; Qu, Xingda; Chen, Chun-Hsien

2016-11-01

The aim of this study was to examine the human-automation interaction issues and the interacting factors in the context of conflict detection and resolution advisory (CRA) systems. The issues of imperfect automation in air traffic control (ATC) have been well documented in previous studies, particularly in conflict-alerting systems. The extent to which the prior findings can be applied to an integrated conflict detection and resolution system in future ATC remains unknown. Twenty-four participants were evenly divided into two groups corresponding to a medium- and a high-traffic density condition, respectively. In each traffic density condition, participants were instructed to perform simulated ATC tasks under four automation conditions, including reliable, unreliable with short time allowance to secondary conflict (TAS), unreliable with long TAS, and manual conditions. Dependent variables accounted for conflict resolution performance, workload, situation awareness, and trust in and dependence on the CRA aid, respectively. Imposing the CRA automation did increase performance and reduce workload as compared with manual performance. The CRA aid did not decrease situation awareness. The benefits of the CRA aid were manifest even when it was imperfectly reliable and were apparent across traffic loads. In the unreliable blocks, trust in the CRA aid was degraded but dependence was not influenced, yet the performance was not adversely affected. The use of CRA aid would benefit ATC operations across traffic densities. CRA aid offers benefits across traffic densities, regardless of its imperfection, as long as its reliability level is set above the threshold of assistance, suggesting its application for future ATC. © 2016, Human Factors and Ergonomics Society.

Exploring imperfect squeezing flow measurements in a Teflon geometry for semisolid foods.

Science.gov (United States)

Terpstra, M E J; Janssen, A M; Linden, E van der

2007-11-01

The method of imperfect lubricated squeezing flow in a Teflontrade mark geometry has been explored for the characterization of elongational behavior of custard and mayonnaise. Two Newtonian products, one of low (0.07 Pas) and one of high (18 Pas) shear viscosity, were used as references. Measurements of custards and mayonnaises did not behave according to either the theory of lubricated or nonlubricated squeezing flow, as there were effects of the initial sample height and compression speed. Also, calculated values for the flow index were not as we had expected. The same was true for the Newtonian samples. An important factor explaining the effect of compression speed was the presence of a certain amount of friction, rendering both lubricated theory and nonlubricated theory nonapplicable. Correcting for (pseudo-) thixotropic behavior of custard and mayonnaise appears to be an effective way of obtaining realistic values for the flow index. The presence of buoyancy also affected the results, especially in the case of low viscous products and the effect of initial sample height. Other factors that played a role in the results were yield stress for custard and mayonnaise and instrumental artifacts associated with the imperfect setup of the measurement, especially for the highly viscous products. Quantitatively correcting the results for all of these factors is not possible at this point. Although the imperfect squeezing flow technique in a Teflon geometry is a very practical way to measure semisolids such as custard and mayonnaise under (partly) elongational deformation, the results should be regarded as more qualitative than quantitative.

Last piece of the puzzle for ATLAS

CERN Multimedia

Clare Ryan

At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern. Each of ATLAS' small wheels are 9.3 metres in diameter and weigh 100 tonnes including the massive shielding elements. They are the final parts of ATLAS' muon spectrometer. The first piece of ATLAS was installed in 2003 and since then many detector elements have journeyed down the 100 metre shaft into the ATLAS underground cavern. This last piece completes this gigantic puzzle.

A Play on Words: Using Cognitive Computing as a Basis for AI Solvers in Word Puzzles

Science.gov (United States)

Manzini, Thomas; Ellis, Simon; Hendler, James

2015-12-01

In this paper we offer a model, drawing inspiration from human cognition and based upon the pipeline developed for IBM's Watson, which solves clues in a type of word puzzle called syllacrostics. We briefly discuss its situation with respect to the greater field of artificial general intelligence (AGI) and how this process and model might be applied to other types of word puzzles. We present an overview of a system that has been developed to solve syllacrostics.

Vibration of imperfect rotating disk

Directory of Open Access Journals (Sweden)

Půst L.

2011-12-01

Full Text Available This study is concerned with the theoretical and numerical calculations of the flexural vibrations of a bladed disk. The main focus of this study is to elaborate the basic background for diagnostic and identification methods for ascertaining the main properties of the real structure or an experimental model of turbine disks. The reduction of undesirable vibrations of blades is proposed by using damping heads, which on the experimental model of turbine disk are applied only on a limited number of blades. This partial setting of damping heads introduces imperfection in mass, stiffness and damping distribution on the periphery and leads to more complicated dynamic properties than those of a perfect disk. Calculation of FEM model and analytic—numerical solution of disk behaviour in the limited (two modes frequency range shows the splitting of resonance with an increasing speed of disk rotation. The spectrum of resonance is twice denser than that of a perfect disk.

Imperfect tax competition for profits, asymmetric equilibrium and beneficial tax havens

DEFF Research Database (Denmark)

Johannesen, Niels

2010-01-01

We present a model of tax competition for real investment and profits and show that the presence of tax havens in some cases increases the tax revenue of countries. In the first part of the paper, we argue that tax competition for profits is likely to be imperfect in the sense that the jurisdicti...... countries. We demonstrate that the latter effect may dominate the former effects so that countries, on balance, benefit from the presence of tax havens.......We present a model of tax competition for real investment and profits and show that the presence of tax havens in some cases increases the tax revenue of countries. In the first part of the paper, we argue that tax competition for profits is likely to be imperfect in the sense that the jurisdiction...... countries. In the second part of the paper, we introduce tax havens. Starting from a symmetric equilibrium, tax havens unambiguously reduce the tax revenue of countries due to a ‘leakage effect' - tax havens attract tax base from countries - and a 'competition effect' - the optimal response to the increased...

Imperfection and radiation damage in protein crystals studied with coherent radiation

Energy Technology Data Exchange (ETDEWEB)

Nave, Colin, E-mail: colin.nave@diamond.ac.uk [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom); Sutton, Geoff [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Evans, Gwyndaf; Owen, Robin; Rau, Christoph [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom); Robinson, Ian [University College London, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Stuart, David Ian [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom)

2016-01-01

Coherent diffraction observations from polyhedra crystals at cryotemperature are reported. Information is obtained about the lattice strain and the changes with radiation damage. Fringes and speckles occur within diffraction spots when a crystal is illuminated with coherent radiation during X-ray diffraction. The additional information in these features provides insight into the imperfections in the crystal at the sub-micrometre scale. In addition, these features can provide more accurate intensity measurements (e.g. by model-based profile fitting), detwinning (by distinguishing the various components), phasing (by exploiting sampling of the molecular transform) and refinement (by distinguishing regions with different unit-cell parameters). In order to exploit these potential benefits, the features due to coherent diffraction have to be recorded and any change due to radiation damage properly modelled. Initial results from recording coherent diffraction at cryotemperatures from polyhedrin crystals of approximately 2 µm in size are described. These measurements allowed information about the type of crystal imperfections to be obtained at the sub-micrometre level, together with the changes due to radiation damage.

Imperfection and radiation damage in protein crystals studied with coherent radiation

International Nuclear Information System (INIS)

Nave, Colin; Sutton, Geoff; Evans, Gwyndaf; Owen, Robin; Rau, Christoph; Robinson, Ian; Stuart, David Ian

2016-01-01

Coherent diffraction observations from polyhedra crystals at cryotemperature are reported. Information is obtained about the lattice strain and the changes with radiation damage. Fringes and speckles occur within diffraction spots when a crystal is illuminated with coherent radiation during X-ray diffraction. The additional information in these features provides insight into the imperfections in the crystal at the sub-micrometre scale. In addition, these features can provide more accurate intensity measurements (e.g. by model-based profile fitting), detwinning (by distinguishing the various components), phasing (by exploiting sampling of the molecular transform) and refinement (by distinguishing regions with different unit-cell parameters). In order to exploit these potential benefits, the features due to coherent diffraction have to be recorded and any change due to radiation damage properly modelled. Initial results from recording coherent diffraction at cryotemperatures from polyhedrin crystals of approximately 2 µm in size are described. These measurements allowed information about the type of crystal imperfections to be obtained at the sub-micrometre level, together with the changes due to radiation damage

Correcting length-frequency distributions for imperfect detection

Science.gov (United States)

Breton, André R.; Hawkins, John A.; Winkelman, Dana L.

2013-01-01

Sampling gear selects for specific sizes of fish, which may bias length-frequency distributions that are commonly used to assess population size structure, recruitment patterns, growth, and survival. To properly correct for sampling biases caused by gear and other sources, length-frequency distributions need to be corrected for imperfect detection. We describe a method for adjusting length-frequency distributions when capture and recapture probabilities are a function of fish length, temporal variation, and capture history. The method is applied to a study involving the removal of Smallmouth Bass Micropterus dolomieu by boat electrofishing from a 38.6-km reach on the Yampa River, Colorado. Smallmouth Bass longer than 100 mm were marked and released alive from 2005 to 2010 on one or more electrofishing passes and removed on all other passes from the population. Using the Huggins mark–recapture model, we detected a significant effect of fish total length, previous capture history (behavior), year, pass, year×behavior, and year×pass on capture and recapture probabilities. We demonstrate how to partition the Huggins estimate of abundance into length frequencies to correct for these effects. Uncorrected length frequencies of fish removed from Little Yampa Canyon were negatively biased in every year by as much as 88% relative to mark–recapture estimates for the smallest length-class in our analysis (100–110 mm). Bias declined but remained high even for adult length-classes (≥200 mm). The pattern of bias across length-classes was variable across years. The percentage of unadjusted counts that were below the lower 95% confidence interval from our adjusted length-frequency estimates were 95, 89, 84, 78, 81, and 92% from 2005 to 2010, respectively. Length-frequency distributions are widely used in fisheries science and management. Our simple method for correcting length-frequency estimates for imperfect detection could be widely applied when mark–recapture data

The Retrofit Puzzle Extended: Optimal Fleet Owner Behavior over Multiple Time Periods

Science.gov (United States)

2009-08-04

In "The Retrofit Puzzle: Optimal Fleet Owner Behavior in the Context of Diesel Retrofit Incentive Programs" (1) an integer program was developed to model profit-maximizing diesel fleet owner behavior when selecting pollution reduction retrofits. Flee...

The Hiroshima neutron dosimetry enigma: Missing puzzle piece No. 6

International Nuclear Information System (INIS)

Gold, Raymond

1999-01-01

More than a decade has elapsed since the serious nature of the discrepancy between neutron dosimetry experiments (E) and neutron transport calculations (C) for the Hiroshima site was identified. Since that time extensive efforts to resolve this Hiroshima neutron dosimetry enigma have not only failed, but now demonstrate that the magnitude of this discrepancy is much greater than initially estimated. The currently evaluated E/C ratio for thermal neutron fluence at the Hiroshima site increases rapidly with increasing slant range from the epicenter. In the slant range region beyond 1000 m, E/C exceeds unity by one to two orders of magnitude depending on the specific dosimetry data that are utilized. Principal features that characterize the Hiroshima neutron dosimetry enigma are summarized. Puzzle Piece No. 6: In-situ production and Prompt fallout of radionuclides from Little Boy is advanced as a possible contributory phenomenon to this enigma. (The atom bomb detonated over Hiroshima was called Little Boy.) Measurements of 60 Co and 152 Eu specific activity at the Hiroshima site are used to obtain order of magnitude numerical estimates that show this conjecture is plausible. Comparison of different 60 Co measurements at the Hiroshima site reveals that the variation of E/C with slant range depends on the method used to quantify 60 Co specific activity as well as the type of dosimetry samples that are employed. These 60 Co comparisons lend additional qualitative credence to this conjecture. Within the limits of presently available data, these assessments show that Puzzle Piece No. 6 qualitatively satisfies the principal features that characterize the Hiroshima neutron dosimetry enigma. Nevertheless, current lack of data prevent this conjecture from being conclusively confirmed or refuted. Consequently, specific recommendations are advanced to resolve the Hiroshima neutron dosimetry enigma with emphasis on experimental tests that can quantitatively evaluate Puzzle Piece

Unraveling "Braid": Puzzle Games and Storytelling in the Imperative Mood

Science.gov (United States)

Arnott, Luke

2012-01-01

"Unraveling Braid" analyzes how unconventional, non-linear narrative fiction can help explain the ways in which video games signify. Specifically, this essay looks at the links between the semiotic features of Jonathan Blow's 2008 puzzle-platform video game Braid and similar elements in Georges Perec's 1978 novel "Life A User's Manual," as well as…

Signatures of the artist the vital imperfections that make our universe habitable

CERN Document Server

Vigdor, Steven E

2018-01-01

How does the scientific enterprise really work to illuminate the origins of life and the universe itself? The quest to understand our universe, how it may have originated and evolved, and especially the conditions that allow it to support the existence of life forms, has been a central theme in religion for millennia and in science for centuries. In the past half-century, in particular, enormous progress in particle and nuclear physics and cosmology has clarified the essential role of imperfections - deviations from perfect symmetry or homogeneity or predictability - in establishing conditions that allow for structure in the universe that can support the development of life. Many of these deviations are tiny and seem mysteriously fine-tuned to allow for life. The goal of this book is to review the recent and ongoing scientific research exploring these imperfections, in a broad-ranging, non-mathematical approach with an emphasis on the intricate tapestry of elegant experiments that bear on the conditions for...

Buckling behaviour of imperfect ring-stiffened cone-cylinder intersections under internal pressure

International Nuclear Information System (INIS)

Zhao, Y.

2005-01-01

Cone-cylinder intersections are used commonly in pressure vessels and piping. In the case of a cone large end-to-cylinder intersection under internal pressure, the intersection is subject to a large circumferential compressive force. While both the cone and the cylinder may be locally thickened to strengthen the intersection, it is often desirable and convenient to provide an annular plate ring at the cone-to-cylinder joint to supplement local thickening or as an alternative strengthening measure, leading to a ring-stiffened cone-cylinder intersection. Only limited work has been carried out specifically on ring-stiffened cone-cylinder intersections under internal pressure. This paper presents the first experimental study on such intersections. In addition to the presentation of test results including geometric imperfections, failure behaviour and the determination of buckling mode and load based on displacement measurements, results from nonlinear bifurcation analysis using the perfect shape and nonlinear analysis using the measured imperfect shape are presented and compared with the experimental results

Moral knowledge and moral factuality

Directory of Open Access Journals (Sweden)

Ron Wilburn

2010-12-01

Full Text Available http://dx.doi.org/10.5007/1677-2954.2008v7n1p69For naturalistic and non-intuitionistic moral realists, moral knowledge is more problematic than ordinary and scientific factual knowledge. For without special faculties of moral discernment, how could we ever detect moral facts and properties? Physical facts and properties may be accessible to perceptual recognition. But how could moral facts and properties ever be similarly accessible? To address this challenge, we need a meta-ethical account that does two things. First, it must explain how the discernment of moral facts and properties ultimately consists only of the detection of appropriate physical items. Second, it must explain why, despite this fact, moral perception seems so very puzzling. In this paper I endeavor to provide such an account. It is largely because of the relational nature of moral properties, and the corresponding externalistically determined normative content of moral property terms, I argue, that our epistemic access to moral knowledge appears mysterious. The metaphysics of moral factuality does a lot to explain the seeming elusiveness of moral knowledge, and in ways that are surprisingly mundane.

A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles

Directory of Open Access Journals (Sweden)

Ricardo Soto

2015-01-01

Full Text Available The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n2 × n2 grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n2. Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods.

Advanced postbuckling and imperfection sensitivity of the elastic-plastic Shanley-Hutchinson model column

DEFF Research Database (Denmark)

Christensen, Claus Dencker; Byskov, Esben

2008-01-01

The postbuckling behavior and imperfection sensitivity of the Shanley-Hutchinson plastic model column introduced by Hutchinson in 1973 are examined. The study covers the initial, buckled state and the advanced postbuckling regime of the geometrically perfect realization as well as its sensitivity...... to geometric imperfections. In Section 1, which is concerned with the perfect structure, a new, simple explicit upper bound for all solutions to the problem is found when the tangent modulus at bifurcation vanishes compared to the linear elastic (unloading) modulus. The difference between the upper bound...... and the solution to an actual problem is determined by an asymptotic expansion involving hyperbolic trial functions (instead of polynomials) which fulfill general boundary conditions at bifurcation and infinity. The method provides an accurate estimate of the maximum load even if it occurs in an advanced...

Crystal imperfection studies of pure and silicon substituted hydroxyapatite using Raman and XRD.

Science.gov (United States)

Zou, Shuo; Huang, Jie; Best, Serena; Bonfield, William

2005-12-01

Hydroxyapatite (HA) is important in biomedical applications because of its chemical similarity to the mineral content of bone and its consequent bioactivity. Silicon substitution into the hydroxyapatite crystal lattice was found to enhance its bioactivity both in vitro and in vivo [1, 2]. However, the mechanism for the enhancement is still not well understood. In this paper, the crystal imperfections introduced by silicon substitution were studied using XRD and Raman spectroscopy. It was found that silicon substitution did not introduce microstrain, but deceased the crystal size in the hk0 direction. Three new vibration modes and peak broadening were observed in Raman spectra following silicon incorporation. The imperfections introduced by silicon substitution may play a role in enhancing bioactivity. A phenomenological relationship between the width of the PO4 v1 peak and crystal size was established.

(Mis)perception of Sleep in Insomnia: A Puzzle and a Resolution

Science.gov (United States)

Harvey, Allison G.; Tang, Nicole K. Y.

2012-01-01

Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not…

Exploring Imperfect Squeezing Flow Measurements in a Teflon Geometry for Semisolid Foods

NARCIS (Netherlands)

Terpstra, M.E.J.; Janssen, A.M.; Linden, van der E.

2007-01-01

The method of imperfect lubricated squeezing flow in a Teflon¿ geometry has been explored for the characterization of elongational behavior of custard and mayonnaise. Two Newtonian products, one of low (0.07 Pas) and one of high (18 Pas) shear viscosity, were used as references. Measurements of

Adding a Piece to the Leaf Epidermal Cell Shape Puzzle.

Science.gov (United States)

von Wangenheim, Daniel; Wells, Darren M; Bennett, Malcolm J

2017-11-06

The jigsaw puzzle-shaped pavement cells in the leaf epidermis collectively function as a load-bearing tissue that controls organ growth. In this issue of Developmental Cell, Majda et al. (2017) shed light on how the jigsaw shape can arise from localized variations in wall stiffness between adjacent epidermal cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Hidden imperfect synchronization of wall turbulence.

Science.gov (United States)

Tardu, Sedat F

2010-03-01

Instantaneous amplitude and phase concept emerging from analytical signal formulation is applied to the wavelet coefficients of streamwise velocity fluctuations in the buffer layer of a near wall turbulent flow. Experiments and direct numerical simulations show both the existence of long periods of inert zones wherein the local phase is constant. These regions are separated by random phase jumps. The local amplitude is globally highly intermittent, but not in the phase locked regions wherein it varies smoothly. These behaviors are reminiscent of phase synchronization phenomena observed in stochastic chaotic systems. The lengths of the constant phase inert (laminar) zones reveal a type I intermittency behavior, in concordance with saddle-node bifurcation, and the periodic orbits of saddle nature recently identified in Couette turbulence. The imperfect synchronization is related to the footprint of coherent Reynolds shear stress producing eddies convecting in the low buffer.

Extended great deluge algorithm for the imperfect preventive maintenance optimization of multi-state systems

International Nuclear Information System (INIS)

Nahas, Nabil; Khatab, Abdelhakim; Ait-Kadi, Daoud; Nourelfath, Mustapha

2008-01-01

This paper deals with preventive maintenance optimization problem for multi-state systems (MSS). This problem was initially addressed and solved by Levitin and Lisnianski [Optimization of imperfect preventive maintenance for multi-state systems. Reliab Eng Syst Saf 2000;67:193-203]. It consists on finding an optimal sequence of maintenance actions which minimizes maintenance cost while providing the desired system reliability level. This paper proposes an approach which improves the results obtained by genetic algorithm (GENITOR) in Levitin and Lisnianski [Optimization of imperfect preventive maintenance for multi-state systems. Reliab Eng Syst Saf 2000;67:193-203]. The considered MSS have a range of performance levels and their reliability is defined to be the ability to meet a given demand. This reliability is evaluated by using the universal generating function technique. An optimization method based on the extended great deluge algorithm is proposed. This method has the advantage over other methods to be simple and requires less effort for its implementation. The developed algorithm is compared to than in Levitin and Lisnianski [Optimization of imperfect preventive maintenance for multi-state systems. Reliab Eng Syst Saf 2000;67:193-203] by using a reference example and two newly generated examples. This comparison shows that the extended great deluge gives the best solutions (i.e. those with minimal costs) for 8 instances among 10

Can the magnetic moment contribution explain the Ay puzzle?

International Nuclear Information System (INIS)

Stoks, V.G.

1998-01-01

We evaluate the full one-photon-exchange Born amplitude for Nd scattering. We include the contributions due to the magnetic moment of the proton or neutron, and the magnetic moment and quadrupole moment of the deuteron. It is found that the inclusion of the magnetic-moment interaction in the theoretical description of the Nd scattering observables cannot resolve the long-standing A y puzzle. copyright 1998 The American Physical Society

Microstructural and crystallographic imperfections of MgB2 superconducting wire and their correlation with the critical current density

Science.gov (United States)

Shahabuddin, Mohammed; Alzayed, Nasser S.; Oh, Sangjun; Choi, Seyong; Maeda, Minoru; Hata, Satoshi; Shimada, Yusuke; Hossain, Md Shahriar Al; Kim, Jung Ho

2014-01-01

A comprehensive study of the effects of structural imperfections in MgB2 superconducting wire has been conducted. As the sintering temperature becomes lower, the structural imperfections of the MgB2 material are increased, as reflected by detailed X-ray refinement and the normal state resistivity. The crystalline imperfections, caused by lattice disorder, directly affect the impurity scattering between the π and σ bands of MgB2, resulting in a larger upper critical field. In addition, low sintering temperature keeps the grain size small, which leads to a strong enhancement of pinning, and thereby, enhanced critical current density. Owing to both the impurity scattering and the grain boundary pinning, the critical current density, irreversibility field, and upper critical field are enhanced. Residual voids or porosities obviously remain in the MgB2, however, even at low sintering temperature, and thus block current transport paths.

Secure Communication for Two-Way Relay Networks with Imperfect CSI

Directory of Open Access Journals (Sweden)

Cong Sun

2017-09-01

Full Text Available This paper considers a two-way relay network, where two legitimate users exchange messages through several cooperative relays in the presence of an eavesdropper, and the Channel State Information (CSI of the eavesdropper is imperfectly known. The Amplify-and-Forward (AF relay protocol is used. We design the relay beamforming weights to minimize the total relay transmit power, while requiring the Signal-to-Noise-Ratio (SNRs of the legitimate users to be higher than the given thresholds and the achievable rate of the eavesdropper to be upper-bounded. Due to the imperfect CSI, a robust optimization problem is summarized. A novel iterative algorithm is proposed, where the line search technique is applied, and the feasibility is preserved during iterations. In each iteration, two Quadratically-Constrained Quadratic Programming (QCQP subproblems and a one-dimensional subproblem are optimally solved. The optimality property of the robust optimization problem is analyzed. Simulation results show that the proposed algorithm performs very close to the non-robust model with perfect CSI, in terms of the obtained relay transmit power; it~achieves higher secrecy rate compared to the existing work. Numerically, the proposed algorithm converges very quickly, and more than 85% of the problems are solved optimally.

Nuclear clustering and the electron screening puzzle

Science.gov (United States)

Bertulani, C. A.; Spitaleri, C.

2018-01-01

Electron screening changes appreciably the magnitude of astrophysical nuclear reactions within stars. This effect is also observed in laboratory experiments on Earth, where atomic electrons are present in the nuclear targets. Theoretical models were developed over the past 30 years and experimental measurements have been carried out to study electron screening in thermonuclear reactions. None of the theoretical models were able to explain the high values of the experimentally determined screening potentials. We explore the possibility that the "electron screening puzzle" is due to nuclear clusterization and polarization e_ects in the fusion reactions. We will discuss the supporting arguments for this scenario.

Market Design and Supply Security in Imperfect Power Markets

DEFF Research Database (Denmark)

Schwenen, Sebastian

2014-01-01

Supply security in imperfect power markets is modelled under different market designs. In a uniform price auction for electricity with two firms, strategic behaviour may leave firms offering too few capacities and unable to supply all realized demand. Market design that relies oncapacity markets...... increases available generation capacities for sufficiently high capacity prices and consequently decreases energy prices. However, equilibrium capacity prices are non-competitive. Capacity markets can increase security of supply, but cannot mitigate market power, which is exercised in the capacity market...

Simulation study on effects of machine imperfections in the KEK B-factory

International Nuclear Information System (INIS)

Koiso, Haruyo; Funakoshi, Yoshihiro

1994-01-01

Effects of machine imperfections in a low beta lattice with noninterleaved sextupoles are studied with computer simulations. Misalignments of quadrupoles and sextupoles significantly degrade the dynamic aperture and the vertical-to-horizontal emittance ratio. However, orbit corrections at sextupoles effectively recover both the dynamic aperture and the emittance ratio. (author)

The Dispersion of the Axisymmetric Longitudinal Waves in the Pre-Strained Bi-Material Hollow Cylinder with the Imperfect Interface Conditions

Science.gov (United States)

Akbarov, S. D.; Ipek, C.

This work studies the influence of the imperfectness of the interface conditions on the dispersion of the axisymmetric longitudinal waves in the pre-strained bi-material hollow cylinder. The investigations are made within the 3D linearized theory of elastic waves in elastic bodies with initial stresses. It is assumed that the materials of the layers of the hollow cylinder are made from hyper elastic compressible materials and the elasticity relations of those are given through the harmonic potential. The shear spring type imperfectness of the interface conditions is considered and the degree of this imperfectness is estimated by the shear-spring parameter. Numerical results on the influence of this parameter on the behavior of the dispersion curves are presented and discussed.

Competing for Customers' Attention: Advertising When Consumers Have Imperfect Memory

OpenAIRE

Oksana Loginova

2005-01-01

This paper applies the theory of memory for advertising, developed in the consumer behavior literature, to an industrial organization setting to provide insight into advertising strategies in imperfectly competitive markets. There are two firms and infinitely many identical consumers. The firms produce a homogeneous product and distribute their brands through a common retailer. Consumers randomly arrive and are willing to buy one unit of the product. They are unaware of the existence of a par...

Foreword in "RF imperfections in high-rate wireless systems: impact and digital compensation"

NARCIS (Netherlands)

Linnartz, J.P.M.G.; Schenk, Tim

2008-01-01

Foreword This book takes a modern, multidisciplinary view on radio system design: the advantages of digital signal processing are exploited to satisfy the ever increasing demands on better performing, flexible radio frequency (RF) circuits. By accepting that analog circuits are inherently imperfect,

Application-Based Crossword Puzzles: Players’ Perception and Vocabulary Retention

Directory of Open Access Journals (Sweden)

Dzulfikri Dzulfikri

2016-09-01

Full Text Available This study investigates the perceptions of students towards Application-Based Crossword Puzzles and how playing this game can affect the development of vocabulary amongst students. Drawing on Vygostky’s Socio-Cultural Theory which states that the human mind is mediated by cultural artifacts, the nature of this game poses challenges and builds curiosity, allowing players to pay more attention to the words to fill in the boxes which subsequently enhances their retention of vocabulary. This game has very good potential to build positive perceptions and to develop cognition in the linguistic domain of players, i.e. the amount of their vocabulary. In this study, the researcher conducted interviews with eligible or selected student players to find out their perceptions toward this game and administered a vocabulary test to find out how this game had added to the retention in memory of new words acquired by the players from the game. The study findings showed that the participants perceive this game positively and it affects the players’ vocabulary retention positively as indicated by their test results. It is recommended that English teachers consider using Application-Based Crossword Puzzles to help students build their vocabularies especially as part of extracurricular activities.

Having Fun and Accepting Challenges Are Natural Instincts: Jigsaw Puzzles to Challenge Students and Test Their Abilities While Having Fun!

Science.gov (United States)

Rodenbaugh, Hanna R.; Lujan, Heidi L.; Rodenbaugh, David W.; DiCarlo, Stephen E.

2014-01-01

Because jigsaw puzzles are fun, and challenging, students will endure and discover that persistence and grit are rewarded. Importantly, play and fun have a biological place just like sleep and dreams. Students also feel a sense of accomplishment when they have completed a puzzle. Importantly, the reward of mastering a challenge builds confidence…

General intelligence is an emerging property, not an evolutionary puzzle.

Science.gov (United States)

Ramus, Franck

2017-01-01

Burkart et al. contend that general intelligence poses a major evolutionary puzzle. This assertion presupposes a reification of general intelligence - that is, assuming that it is one "thing" that must have been selected as such. However, viewing general intelligence as an emerging property of multiple cognitive abilities (each with their own selective advantage) requires no additional evolutionary explanation.

Economic production quantity concerning learning and the reworking of imperfect items

Directory of Open Access Journals (Sweden)

Tsai Deng-Maw

2012-01-01

Full Text Available The classical economic production quantity (EPQ model assumes that items produced are of perfect quality and the production rate is constant. However, production quality depends on the condition of the process. Due to process deterioration or other factors, the production process may shift and produce imperfect quality items. These imperfect quality items sometimes can be reworked and repaired; hence, overall production-inventory costs can be reduced significantly. In addition, it can be found in practice that the time or cost required to repetitively produce a unit of a product decreases when the number of units produced by a worker or a group of workers increases. Under this circumstance, the unit production cost cannot be regarded as constant and, therefore, cannot be ignored when taking account of the total cost. This paper incorporates the effects of learning and the reworking of defective items on the EPQ model since they were not considered in existing models. An optimal operation policy that minimizes the expected total cost per unit time is derived. A numerical example is provided to illustrate the proposed model. In addition, sensitivity analysis is performed and discussed.

Right frontal gamma and beta band enhancement while solving a spatial puzzle with insight.

Science.gov (United States)

Rosen, A; Reiner, M

2017-12-01

Solving a problem with an "a-ha" effect is known as insight. Unlike incremental problem solving, insight is sudden and unique, and the question about its distinct brain activity, intrigues many researchers. In this study, electroencephalogram signals were recorded from 12 right handed, human participants before (baseline) and while they solved a spatial puzzle known as the '10 coin puzzle' that could be solved incrementally or by insight. Participants responded as soon as they reached a solution and reported whether the process was incremental or by sudden insight. EEG activity was recorded from 19 scalp locations. We found significant differences between insight and incremental solvers in the Gamma and Beta 2 bands in frontal areas (F8) and in the alpha band in right temporal areas (T6). The right-frontal gamma indicates a process of restructuring which leads to an insight solution, in spatial problems, further suggesting a universal role of gamma in restructuring. These results further suggest that solving a spatial puzzle via insight requires exclusive brain areas and neurological-cognitive processes which may be important for meta-cognitive components of insight solutions, including attention and monitoring of the solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Changes in food intake and abnormal behavior using a puzzle feeder in newly acquired sub-adult rhesus monkeys (Macaca mulatta): a short term study.

Science.gov (United States)

Lee, Jae-Il; Lee, Chi-Woo; Kwon, Hyouk-Sang; Kim, Young-Tae; Park, Chung-Gyu; Kim, Sang-Joon; Kang, Byeong-Cheol

2008-10-01

The majority of newly acquired nonhuman primates encounter serious problems adapting themselves to new environments or facilities. In particular, loss of appetite and abnormal behavior can occur in response to environmental stresses. These adaptation abnormalities can ultimately have an affect on the animal's growth and well-being. In this study, we evaluated the affects of a puzzle feeder on the food intake and abnormal behavior of newly acquired rhesus monkeys for a short period. The puzzle feeder was applied to 47- to 58-month-old animals that had never previously encountered one. We found that there was no difference in the change of food intake between the bucket condition and the puzzle feeder condition. In contrast, the time spent for consumption of food was three times longer in the puzzle feeder condition than in the bucket condition. Two monkeys initially exhibited stereotypic behavior. One showed a decreasing, and the other an increasing pattern of abnormal behavior after introduction of the puzzle feeder. In conclusion, this result suggests that over a short period, the puzzle feeder can only affect the time for food consumption since it failed to affect the food intake and did not consistently influence stereotypic behaviors in newly acquired rhesus monkeys.

Changes in the transmission properties of multi-tooth plasmonic nano-filters (multi-TPNFs) caused by geometrical imperfection

International Nuclear Information System (INIS)

Khaksar, A; Fatemi, H

2012-01-01

To model the filtering behavior of a multi-tooth plasmonic nano-filter (multi-TPNF), an equivalent circuitry composed of a set of serried impedances is considered. The changes caused in its filtering behavior are proposed as a measuring tool to investigate the effect of the geometrical imperfections occurring during the manufacture of the device. Consequently, the effects of changes in the nominal size of each of the geometrical parameters of a multi-TPNF sample, such as its tooth height, d, its tooth width, w, and the separation between two successive teeth, Δ, on its transmittance are investigated. It is observed that each single tooth of the multi-TPNF and also the waveguide between any of its two successive teeth exhibit a very Fabry–Perot interferometer like behavior. The variation of the transmission spectra of a multi-TPNF whose geometrical parameters are imperfect is compared with the desired filter, and also the effect of the number of geometrically imperfect teeth of the multi-TPNF on the filtering spectra is examined. (paper)

Stability of continuous-time quantum filters with measurement imperfections

Science.gov (United States)

Amini, H.; Pellegrini, C.; Rouchon, P.

2014-07-01

The fidelity between the state of a continuously observed quantum system and the state of its associated quantum filter, is shown to be always a submartingale. The observed system is assumed to be governed by a continuous-time Stochastic Master Equation (SME), driven simultaneously by Wiener and Poisson processes and that takes into account incompleteness and errors in measurements. This stability result is the continuous-time counterpart of a similar stability result already established for discrete-time quantum systems and where the measurement imperfections are modelled by a left stochastic matrix.

Imperfect linear-optical photonic gates with number-resolving photodetection

International Nuclear Information System (INIS)

Smith, A. Matthew; Uskov, D. B.; Ying, L. H.; Kaplan, L.

2011-01-01

We use the numerical optimization techniques of Uskov et al.[Phys. Rev. A 81, 012303 (2010)] to investigate the behavior of the success rates for Knill-Laflamme-Milburn-style [Knill et al., Nature (London) 409, 46 (2001)] two- and three-qubit entangling gates. The methods are first demonstrated at perfect fidelity and then extended to imperfect gates. We find that as the perfect fidelity condition is relaxed, the maximum attainable success rates increase in a predictable fashion depending on the size of the system, and we compare that rate of increase for several gates.

Imperfect Preventive Maintenance Model Study Based On Reliability Limitation

Directory of Open Access Journals (Sweden)

Zhou Qian

2016-01-01

Full Text Available Effective maintenance is crucial for equipment performance in industry. Imperfect maintenance conform to actual failure process. Taking the dynamic preventive maintenance cost into account, the preventive maintenance model was constructed by using age reduction factor. The model regards the minimization of repair cost rate as final target. It use allowed smallest reliability as the replacement condition. Equipment life was assumed to follow two parameters Weibull distribution since it was one of the most commonly adopted distributions to fit cumulative failure problems. Eventually the example verifies the rationality and benefits of the model.

Fluctuation-induced forces in confined ideal and imperfect Bose gases.

Science.gov (United States)

Diehl, H W; Rutkevich, Sergei B

2017-06-01

Fluctuation-induced ("Casimir") forces caused by thermal and quantum fluctuations are investigated for ideal and imperfect Bose gases confined to d-dimensional films of size ∞^{d-1}×D under periodic (P), antiperiodic (A), Dirichlet-Dirichlet (DD), Neumann-Neumann (NN), and Robin (R) boundary conditions (BCs). The full scaling functions Υ_{d}^{BC}(x_{λ}=D/λ_{th},x_{ξ}=D/ξ) of the residual reduced grand potential per area φ_{res,d}^{BC}(T,μ,D)=D^{-(d-1)}Υ_{d}^{BC}(x_{λ},x_{ξ}) are determined for the ideal gas case with these BCs, where λ_{th} and ξ are the thermal de Broglie wavelength and the bulk correlation length, respectively. The associated limiting scaling functions Θ_{d}^{BC}(x_{ξ})≡Υ_{d}^{BC}(∞,x_{ξ}) describing the critical behavior at the bulk condensation transition are shown to agree with those previously determined from a massive free O(2) theory for BC=P,A,DD,DN,NN. For d=3, they are expressed in closed analytical form in terms of polylogarithms. The analogous scaling functions Υ_{d}^{BC}(x_{λ},x_{ξ},c_{1}D,c_{2}D) and Θ_{d}^{R}(x_{ξ},c_{1}D,c_{2}D) under the RBCs (∂_{z}-c_{1})ϕ|_{z=0}=(∂_{z}+c_{2})ϕ|_{z=D}=0 with c_{1}≥0 and c_{2}≥0 are also determined. The corresponding scaling functions Υ_{∞,d}^{P}(x_{λ},x_{ξ}) and Θ_{∞,d}^{P}(x_{ξ}) for the imperfect Bose gas are shown to agree with those of the interacting Bose gas with n internal degrees of freedom in the limit n→∞. Hence, for d=3, Θ_{∞,d}^{P}(x_{ξ}) is known exactly in closed analytic form. To account for the breakdown of translation invariance in the direction perpendicular to the boundary planes implied by free BCs such as DDBCs, a modified imperfect Bose gas model is introduced that corresponds to the limit n→∞ of this interacting Bose gas. Numerically and analytically exact results for the scaling function Θ_{∞,3}^{DD}(x_{ξ}) therefore follow from those of the O(2n)ϕ^{4} model for n→∞.

Freestyle multiple propeller flap reconstruction (jigsaw puzzle approach) for complicated back defects.

Science.gov (United States)

Park, Sung Woo; Oh, Tae Suk; Eom, Jin Sup; Sun, Yoon Chi; Suh, Hyun Suk; Hong, Joon Pio

2015-05-01

The reconstruction of the posterior trunk remains to be a challenge as defects can be extensive, with deep dead space, and fixation devices exposed. Our goal was to achieve a tension-free closure for complex defects on the posterior trunk. From August 2006 to May 2013, 18 cases were reconstructed with multiple flaps combining perforator(s) and local skin flaps. The reconstructions were performed using freestyle approach. Starting with propeller flap(s) in single or multilobed design and sequentially in conjunction with adjacent random pattern flaps such as fitting puzzle. All defects achieved tensionless primary closure. The final appearance resembled a jigsaw puzzle-like appearance. The average size of defect was 139.6 cm(2) (range, 36-345 cm(2)). A total of 26 perforator flaps were used in addition to 19 random pattern flaps for 18 cases. In all cases, a single perforator was used for each propeller flap. The defect and the donor site all achieved tension-free closure. The reconstruction was 100% successful without flap loss. One case of late infection was noted at 12 months after surgery. Using multiple lobe designed propeller flaps in conjunction with random pattern flaps in a freestyle approach, resembling putting a jigsaw puzzle together, we can achieve a tension-free closure by distributing the tension to multiple flaps, supplying sufficient volume to obliterate dead space, and have reliable vascularity as the flaps do not need to be oversized. This can be a viable approach to reconstruct extensive defects on the posterior trunk. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A new piece of the puzzle

CERN Multimedia

2005-01-01

The team responsible for the installation of the hadronic calorimeter's central barrel after completion of the assembly work. Assembly of the great ATLAS puzzle continues underground. On 10 December, the final module of the central barrel of the tile hadronic calorimeter was assembled. This piece of the tile calorimeter had already been assembled above ground during a "dress rehearsal" in 2003 (see Bulletin no 46/2003, 10 November 2003). The hadronic calorimeter's two other barrels, the so-called "extended barrels", remain to be assembled with this first central barrel, which now surrounds the electromagnetic calorimeter barrel that was lowered into the cavern at the end of October. At the end of November, the second of the eight barrel toroid coils was also installed.

The proton radius puzzle

Science.gov (United States)

Bonesini, Maurizio

2017-12-01

The FAMU (Fisica degli Atomi Muonici) experiment has the goal to measure precisely the proton Zemach radius, thus contributing to the solution of the so-called proton radius "puzzle". To this aim, it makes use of a high-intensity pulsed muon beam at RIKEN-RAL impinging on a cryogenic hydrogen target with an high-Z gas admixture and a tunable mid-IR high power laser, to measure the hyperfine (HFS) splitting of the 1S state of the muonic hydrogen. From the value of the exciting laser frequency, the energy of the HFS transition may be derived with high precision ( 10-5) and thus, via QED calculations, the Zemach radius of the proton. The experimental apparatus includes a precise fiber-SiPMT beam hodoscope and a crown of eight LaBr3 crystals and a few HPGe detectors for detection of the emitted characteristic X-rays. Preliminary runs to optimize the gas target filling and its operating conditions have been taken in 2014 and 2015-2016. The final run, with the pump laser to drive the HFS transition, is expected in 2018.

Pengaruh Model Pembelajaran Kooperatif Tipe Time Token Berbantu Puzzle Terhadap Kemampuan Berpikir Kritis Peserta Didik Kelas X Pada Materi Gelombang

Directory of Open Access Journals (Sweden)

Sri Latifah

2015-04-01

Full Text Available The purpose in this research is to know the influence of cooperative Learning Models Time Type Token with puzzle toward critical thought abilityof the students grade X on Wave material at MA Al Hikmah Bandar Lampung year2014/2015 This research is quantitative with quasi experiment. Reasearch design that used is Nonequivalent Control Group Design with the population of all the students in grade X semestre even at MA Al Hikmah, Bandar Lampung year 2014/2015. The Sample of this research are used 2 classes; experiment and control class, where as experiment class (XA used cooperative time type token model with puzzle and control class (XB used cooperative learning model with pictures as media. Data colecting is using test (pretest and posttest, observation and documentation. After the data test collected, then it is analyzed by using normality test of statistic analysis, homoginity test and test-t. According to the result, it can be concluded that time type token with puzzle application influence significantly ttoward the ability of critical thinking of the students on Wave material at MA Al Hikmah Bandar Lampung year 2014/2015. Tujuan penelitian ini adalah untuk mengetahui pengaruh model pembelajaran kooperatif tipe time token berbantu puzzle terhadap kemampuan berpikir kritis peserta didik kelas X pada materi Gelombang di MA Al Hikmah Bandar Lampung Tahun Pelajaran 2014/2015 .Penelitian ini termasuk kedalam penelitian kuantitatif dengan jenis penelitian Quasi Eksperimen. Desain penelitian ini menggunakan Nonequivalent Control Group Design dengan populasi yaitu seluruh peserta didik kelas X semester genap di MA Al Hikmah Bandar Lampung T.P 2014/2015. Sampel penelitian ini menggunakan 2 kelas yaitu kelas eksperimen dan kontrol, dimana kelas eksperimen (XA menggunakan model kooperatif tipe time token berbantu puzzle dan kelas kontrol (XB menggunakan model pembelajaran kooperatif media gambar. Teknik pengambilan data menggunakan test (pretest dan

ysteries, Puzzles, and Paradoxes in Quantum Mechanics. Proceedings

International Nuclear Information System (INIS)

Rodolfo, B.

1999-01-01

These proceedings represent papers presented at the Mysteries, Puzzles, and Paradoxes in Quantum Mechanics Workshop held in Italy, in August 1998. The Workshop was devoted to recent experimental and theoretical advances such as new interference, effects, the quantum eraser, non-disturbing and Schroedinger-cat-like states, experiments, EPR correlations, teleportation, superluminal effects, quantum information and computing, locality and causality, decoherence and measurement theory. Tachyonic information transfer was also discussed. There were 45 papers presented at the conference,out of which 2 have been abstracted for the Energy, Science and Technology database

Information structures in economics studies in the theory of markets with imperfect information

CERN Document Server

Nermuth, Manfred

1982-01-01

This book is intended as a contribution to the theory of markets with imperfect information. The subject being nearly limitless, only certain selected topics are discussed. These are outlined in the Introduction (Ch. 0). The remainder of the book is divided into three parts. All results of economic significance are contained in Parts II & III. Part I introduces the main tools for the analysis, in particular the concept of an information structure. Although most of the material presented in Part I is not original, it is hoped that the detailed and self-contained exposition will help the reader to understand not only the following pages, but also the existing technical and variegated literature on markets with imperfect information. The mathematical prerequisites needed, but not explained in the text rarely go beyond elementary calculus and probability theory. Whenever more advanced concepts are used, I have made an effort to give an intuitive explanation as well, so that the argument can also be followed o...

Dynamic instability of imperfect laminated sandwich plates with in-plane partial edge load

Directory of Open Access Journals (Sweden)

Anupam Chakrabarti

Full Text Available Dynamic instability of laminated sandwich plates having inter-laminar imperfections with in-plane partial edge loading is studied for the first time using an efficient finite element plate model. The plate model is based on a refined higher order shear deformation plate theory, where the transverse shear stresses are continuous at the layer interfaces with stress free conditions at plate top and bottom surfaces. A linear spring-layer model is used to model the inter-laminar imperfection by considering in-plane displacement jumps at the interfaces. Interestingly the plate model having all these refined features requires unknowns at the reference plane only. However, this theory requires C1 continuity of transverse displacement (w i.e., w and its derivatives should be continuous at the common edges between two elements, which is difficult to satisfy arbitrarily in any existing finite element. To deal with this, a new triangular element developed by the authors is used in the present paper.

Reduction of shock induced noise in imperfectly expanded supersonic jets using convex optimization

Science.gov (United States)

Adhikari, Sam

2007-11-01

Imperfectly expanded jets generate screech noise. The imbalance between the backpressure and the exit pressure of the imperfectly expanded jets produce shock cells and expansion or compression waves from the nozzle. The instability waves and the shock cells interact to generate the screech sound. The mathematical model consists of cylindrical coordinate based full Navier-Stokes equations and large-eddy-simulation turbulence modeling. Analytical and computational analysis of the three-dimensional helical effects provide a model that relates several parameters with shock cell patterns, screech frequency and distribution of shock generation locations. Convex optimization techniques minimize the shock cell patterns and the instability waves. The objective functions are (convex) quadratic and the constraint functions are affine. In the quadratic optimization programs, minimization of the quadratic functions over a set of polyhedrons provides the optimal result. Various industry standard methods like regression analysis, distance between polyhedra, bounding variance, Markowitz optimization, and second order cone programming is used for Quadratic Optimization.

Microstructural and crystallographic imperfections of MgB{sub 2} superconducting wire and their correlation with the critical current density

Energy Technology Data Exchange (ETDEWEB)

Shahabuddin, Mohammed; Alzayed, Nasser S. [Department of Physics and Astronomy, College of Science, P. O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia); Oh, Sangjun [Materials Research Team, National Fusion Research Institute, Yueeong, Daejeon 305-333 (Korea, Republic of); Choi, Seyong [Busan Center, Korea Basic Science Institute, Geumjeong, Busan 609-735 (Korea, Republic of); Maeda, Minoru [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Hata, Satoshi; Shimada, Yusuke [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Hossain, Md Shahriar Al [Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia); Kim, Jung Ho, E-mail: jhk@uow.edu.au [Department of Physics and Astronomy, College of Science, P. O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia); Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia)

2014-01-15

A comprehensive study of the effects of structural imperfections in MgB{sub 2} superconducting wire has been conducted. As the sintering temperature becomes lower, the structural imperfections of the MgB{sub 2} material are increased, as reflected by detailed X-ray refinement and the normal state resistivity. The crystalline imperfections, caused by lattice disorder, directly affect the impurity scattering between the π and σ bands of MgB{sub 2}, resulting in a larger upper critical field. In addition, low sintering temperature keeps the grain size small, which leads to a strong enhancement of pinning, and thereby, enhanced critical current density. Owing to both the impurity scattering and the grain boundary pinning, the critical current density, irreversibility field, and upper critical field are enhanced. Residual voids or porosities obviously remain in the MgB{sub 2}, however, even at low sintering temperature, and thus block current transport paths.

Can Equity Volatility Explain the Global Loan Pricing Puzzle?

OpenAIRE

Lewis Gaul; Pinar Uysal

2013-01-01

This paper examines whether unobservable differences in firm volatility are responsible for the global loan pricing puzzle, which is the observation that corporate loan interest rates appear to be lower in Europe than in the United States. We analyze whether equity volatility, an error prone measure of firm volatility, can explain this difference in loan spreads. We show that using equity volatility in OLS regressions will result in biased and inconsistent estimates of the difference in U.S. ...

Black-hole information puzzle: a generic string-inspired approach

International Nuclear Information System (INIS)

Nikolic, H.

2008-01-01

Given the insight stemming from string theory, the origin of the black-hole (BH) information puzzle is traced back to the assumption that it is physically meaningful to trace out the density matrix over negative-frequency Hawking particles. Instead, treating them as virtual particles necessarily absorbed by the BH in a manner consistent with the laws of BH thermodynamics, and tracing out the density matrix only over physical BH states, complete evaporation becomes compatible with unitarity. (orig.)

Relay Precoder Optimization in MIMO-Relay Networks With Imperfect CSI

KAUST Repository

Pandarakkottilil, Ubaidulla

2011-11-01

In this paper, we consider robust joint designs of relay precoder and destination receive filters in a nonregenerative multiple-input multiple-output (MIMO) relay network. The network consists of multiple source-destination node pairs assisted by a MIMO-relay node. The channel state information (CSI) available at the relay node is assumed to be imperfect. We consider robust designs for two models of CSI error. The first model is a stochastic error (SE) model, where the probability distribution of the CSI error is Gaussian. This model is applicable when the imperfect CSI is mainly due to errors in channel estimation. For this model, we propose robust minimum sum mean square error (SMSE), MSE-balancing, and relay transmit power minimizing precoder designs. The next model for the CSI error is a norm-bounded error (NBE) model, where the CSI error can be specified by an uncertainty set. This model is applicable when the CSI error is dominated by quantization errors. In this case, we adopt a worst-case design approach. For this model, we propose a robust precoder design that minimizes total relay transmit power under constraints on MSEs at the destination nodes. We show that the proposed robust design problems can be reformulated as convex optimization problems that can be solved efficiently using interior-point methods. We demonstrate the robust performance of the proposed design through simulations. © 2011 IEEE.

Transitioning to future air traffic management: effects of imperfect automation on controller attention and performance.

Science.gov (United States)

Rovira, Ericka; Parasuraman, Raja

2010-06-01

This study examined whether benefits of conflict probe automation would occur in a future air traffic scenario in which air traffic service providers (ATSPs) are not directly responsible for freely maneuvering aircraft but are controlling other nonequipped aircraft (mixed-equipage environment). The objective was to examine how the type of automation imperfection (miss vs. false alarm) affects ATSP performance and attention allocation. Research has shown that the type of automation imperfection leads to differential human performance costs. Participating in four 30-min scenarios were 12 full-performance-level ATSPs. Dependent variables included conflict detection and resolution performance, eye movements, and subjective ratings of trust and self confidence. ATSPs detected conflicts faster and more accurately with reliable automation, as compared with manual performance. When the conflict probe automation was unreliable, conflict detection performance declined with both miss (25% conflicts detected) and false alarm automation (50% conflicts detected). When the primary task of conflict detection was automated, even highly reliable yet imperfect automation (miss or false alarm) resulted in serious negative effects on operator performance. The further in advance that conflict probe automation predicts a conflict, the greater the uncertainty of prediction; thus, designers should provide users with feedback on the state of the automation or other tools that allow for inspection and analysis of the data underlying the conflict probe algorithm.

On the ergodic secrecy capacity of the wiretap channel under imperfect main channel estimation

KAUST Repository

Rezki, Zouheir; Khisti, Ashish J.; Alouini, Mohamed-Slim

2011-01-01

imperfect main channel estimation at the transmitter. Inner and outer bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate is a simple on-off scheme using a

An Imperfect Understanding: The Air Forces Transition to Diversity and Inclusion

Science.gov (United States)

2016-01-01

Summer 2016 | 79 An Imperfect Understanding The Air Force’s Transition to Diversity and Inclusion Maj Gregory M. Blom, USAF Mrs. Brittany B. Davis... inclusion program. The service’s senior leaders have determined that di- versity and inclusion are requisites for effective operations, and in March...2015 they unveiled new proposals for increasing them within the Air Force.2 Designed to strengthen the service, the nine diversity and inclusion

MHD pressure drop of imperfect insulation of liquid metal flow

International Nuclear Information System (INIS)

Horiike, H.; Nishiura, R.; Inoue, S.; Miyazaki, K.

2000-01-01

An experiment was performed to study magnetohydrodynamic (MHD) pressure gradient in the case of an imperfect electric insulation coating when using NaK loop. Test channels with uniform defects in their coating were made by painting inner surface with acrylic lacquer insulation. It was found that the exponent to B -- which is 1 for insulated walls, and 2 for conducting ones, was very sensitive to crack fractions lower than 25%. The pressure gradient was found to increase almost linearly with the fraction

Accounting for imperfect detection in Hill numbers for biodiversity studies

Science.gov (United States)

Broms, Kristin M.; Hooten, Mevin B.; Fitzpatrick, Ryan M.

2015-01-01

Hill numbers unify biodiversity metrics by combining several into one expression. For example, species richness, Shannon's diversity index and the Gini–Simpson index are a few of the most used diversity measures, and they can be expressed as Hill numbers. Traditionally, Hill numbers have been calculated from relative abundance data, but the expression has been modified to use incidence data as well. We demonstrate an approach for estimating Hill numbers using an occupancy modelling framework that accounts for imperfect detection.

Surface impedance and optimum surface resistance of a superconductor with an imperfect surface

Science.gov (United States)

Gurevich, Alex; Kubo, Takayuki

2017-11-01

We calculate a low-frequency surface impedance of a dirty, s -wave superconductor with an imperfect surface incorporating either a thin layer with a reduced pairing constant or a thin, proximity-coupled normal layer. Such structures model realistic surfaces of superconducting materials which can contain oxide layers, absorbed impurities, or nonstoichiometric composition. We solved the Usadel equations self-consistently and obtained spatial distributions of the order parameter and the quasiparticle density of states which then were used to calculate a low-frequency surface resistance Rs(T ) and the magnetic penetration depth λ (T ) as functions of temperature in the limit of local London electrodynamics. It is shown that the imperfect surface in a single-band s -wave superconductor results in a nonexponential temperature dependence of Z (T ) at T ≪Tc which can mimic the behavior of multiband or d -wave superconductors. The imperfect surface and the broadening of the gap peaks in the quasiparticle density of states N (ɛ ) in the bulk give rise to a weakly temperature-dependent residual surface resistance. We show that the surface resistance can be optimized and even reduced below its value for an ideal surface by engineering N (ɛ ) at the surface using pair-breaking mechanisms, particularly by incorporating a small density of magnetic impurities or by tuning the thickness and conductivity of the normal layer and its contact resistance. The results of this work address the limit of Rs in superconductors at T ≪Tc , and the ways of engineering the optimal density of states by surface nanostructuring and impurities to reduce losses in superconducting microresonators, thin-film strip lines, and radio-frequency cavities for particle accelerators.

Insecurity of imperfect quantum bit seal

International Nuclear Information System (INIS)

Chau, H.F.

2006-01-01

Quantum bit seal is a way to encode a classical bit quantum mechanically so that everyone can obtain non-zero information on the value of the bit. Moreover, such an attempt should have a high chance of being detected by an authorized verifier. Surely, a reader looks for a way to get the maximum amount of information on the sealed bit and at the same time to minimize her chance of being caught. And a verifier picks a sealing scheme that maximizes his chance of detecting any measurement of the sealed bit. Here, I report a strategy that passes all measurement detection procedures at least half of the time for all quantum bit sealing schemes. This strategy also minimizes a reader's chance of being caught under a certain scheme. In this way, I extend the result of Bechmann-Pasquinucci et al. by proving that quantum seal is insecure in the case of imperfect sealed bit recovery

Nonlinear dynamics of an electrically actuated imperfect microbeam resonator: Experimental investigation and reduced-order modeling

KAUST Repository

Ruzziconi, Laura; Bataineh, Ahmad M.; Younis, Mohammad I.; Cui, Weili; Lenci, Stefano

2013-01-01

We present a study of the dynamic behavior of a microelectromechanical systems (MEMS) device consisting of an imperfect clamped-clamped microbeam subjected to electrostatic and electrodynamic actuation. Our objective is to develop a theoretical

Pilot Dependence on Imperfect Diagnostic Automation in Simulated UAV Flights: An Attentional Visual Scanning Analysis

National Research Council Canada - National Science Library

Wickens, Christopher; Dixon, Stephen; Goh, Juliana; Hammer, Ben

2005-01-01

An unmanned air vehicle (UAV) simulation was designed to reveal the effects of imperfectly reliable diagnostic automation a monitor of system health parameters on pilot attention, as the latter was assessed via visual scanning...

A new robust design for imperfection sensitive stiffened cylinders used in aerospace engineering

NARCIS (Netherlands)

Liang, K.; Zhang, Y.; Sun, Q.; Ruess, M.

2015-01-01

A knock-down factor is commonly used to take into account the obvious decline of the buckling load in a cylindrical shell caused by the inevitable imperfections. In 1968, NASA guideline SP-8007 gave knock-down factors which rely on a lower-bound curve taken from experimental data. Recent research

On imperfect node protection in complex communication networks

International Nuclear Information System (INIS)

Xiao Shi; Xiao Gaoxi

2011-01-01

Motivated by recent research on complex networks, we study enhancing complex communication networks against intentional attack which takes down network nodes in a decreasing order of their degrees. Specifically, we evaluate an effect which has been largely ignored in existing studies; many real-life systems, especially communication systems, have protection mechanisms for their important components. Due to the existence of such protection, it is generally quite difficult to totally crash a protected node, though partially paralyzing it may still be feasible. Our analytical and simulation results show that such 'imperfect' protections generally speaking still help significantly enhance network robustness. Such insight may be helpful for the future developments of efficient network attack and protection schemes.

On imperfect node protection in complex communication networks

Energy Technology Data Exchange (ETDEWEB)

Xiao Shi [Hubei Province Key Laboratory of Intelligent Robot and School of Computer Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Xiao Gaoxi, E-mail: xiao_moon2002@yahoo.com.cn, E-mail: egxxiao@ntu.edu.sg [Division of Communication Engineering, School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 (Singapore)

2011-02-04

Motivated by recent research on complex networks, we study enhancing complex communication networks against intentional attack which takes down network nodes in a decreasing order of their degrees. Specifically, we evaluate an effect which has been largely ignored in existing studies; many real-life systems, especially communication systems, have protection mechanisms for their important components. Due to the existence of such protection, it is generally quite difficult to totally crash a protected node, though partially paralyzing it may still be feasible. Our analytical and simulation results show that such 'imperfect' protections generally speaking still help significantly enhance network robustness. Such insight may be helpful for the future developments of efficient network attack and protection schemes.

The Puzzle of a Marble in a Spinning Pipe

Science.gov (United States)

2015-05-01

MAY 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE The Puzzle of a Marble in a Spinning Pipe 5a. CONTRACT...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT What trajectory does a marble follow if it is held...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Physics Education 50 (3) 279 1. Problem statement A marble is placed one-third of the length along a

Analysis of imperfections in the coherent optical excitation of single atoms to Rydberg states

Science.gov (United States)

de Léséleuc, Sylvain; Barredo, Daniel; Lienhard, Vincent; Browaeys, Antoine; Lahaye, Thierry

2018-05-01

We study experimentally various physical limitations and technical imperfections that lead to damping and finite contrast of optically driven Rabi oscillations between ground and Rydberg states of a single atom. Finite contrast is due to preparation and detection errors, and we show how to model and measure them accurately. Part of these errors originates from the finite lifetime of Rydberg states, and we observe its n3 scaling with the principal quantum number n . To explain the damping of Rabi oscillations, we use simple numerical models taking into account independently measured experimental imperfections and show that the observed damping actually results from the accumulation of several small effects, each at the level of a few percent. We discuss prospects for improving the coherence of ground-Rydberg Rabi oscillations in view of applications in quantum simulation and quantum information processing with arrays of single Rydberg atoms.

The Puzzle of Male Chronophilias.

Science.gov (United States)

Seto, Michael C

2017-01-01

In this article, I return to the idea that pedophilia, a sexual interest in prepubescent children, can be considered a sexual orientation for age, in conjunction with the much more widely acknowledged and discussed sexual orientation for gender. Here, I broaden the scope to consider other chronophilias, referring to paraphilias for age/maturity categories other than young sexually mature adults. The puzzle of chronophilias includes questions about etiology and course, how chronophilias are related to each other, and what they can tell us about how human (male) sexuality is organized. In this article, I briefly review research on nepiophilia (infant/toddlers), pedophilia (prepubescent children), hebephilia (pubescent children), ephebophilia (postpubescent, sexually maturing adolescents), teleiophilia (young sexually mature adults, typically 20s and 30s), mesophilia (middle-aged adults, typically 40s and 50s), and gerontophilia (elderly adults, typically 60s and older) in the context of a multidimensional sexual orientations framework. Relevant research, limitations, and testable hypotheses for future work are identified.

The Eco-Efficiency Premium Puzzle

International Nuclear Information System (INIS)

Guenster, N.; Derwall, J.; Bauer, R.; Koedijk, K.

2004-09-01

Conventional investment theory suggests that socially responsible investing (SRI) leads to inferior, rather than superior, portfolio performance. Using Innovest's well-established corporate eco-efficiency scores, we provide evidence supporting the contrary. We compose two equity portfolios that differ in ecoefficiency characteristics and find that our high-ranked portfolio provided substantially higher average returns compared to its low-ranked counterpart over the period 1995-2003. Using a wide range of performance attribution techniques to address common methodological concerns, we show that this performance differential cannot be explained by differences in market sensitivity, investment style, or industry-specific components. We finally investigate whether this ecoefficiency premium puzzle withstands the inclusion of transaction costs scenarios, and evaluate how excess returns can be earned in a practical setting via a best-in-class stock selection strategy. The results remain significant under all levels of transactions costs, thus suggesting that the incremental benefits of SRI can be substantial

Effects of age and type of picture on visuospatial working memory assessed with a computerized jigsaw-puzzle task.

Science.gov (United States)

Toril, Pilar; Reales, José M; Mayas, Julia; Ballesteros, Soledad

2017-09-15

We investigated the effect of age and color in a computerized version of the jigsaw-puzzle task. In Experiment 1, young and older adults were presented with puzzles in color and black-and-white line drawings, varying in difficulty from 4 to 9 pieces. Older adults performed the task better with the black-and-white stimuli and younger adults performed better with the color ones. In Experiment 2, new older and young adults identified the same fragmented pictures as fast and accurately as possible. The older group identified the black-and-white stimuli faster than those presented in color, while the younger adults identified both similarly. In Experiment 3A, new older and young groups performed the puzzle task with the same color pictures and their monochrome versions. In Experiment 3B, participants performed a speeded identification task with the two sets. The findings of these experiments showed that older adults have a memory not a perceptual difficulty.

Economic production quantity models for imperfect product and service with rework

OpenAIRE

Tai, Allen H.

2012-01-01

When imperfect quality products are produced in a production process, rework may be performed to make them become serviceable. In an inventory system, items may deteriorate. Selling deteriorated items to customers will create negative impact on corporate image. In this paper, two economic production quantity (EPQ) models are proposed for deteriorating items with rework process. A single production-rework plant system and a system consists of $n$ production plants and one rework plant are cons...

Uncertainty management using bayesian networks in student knowledge diagnosis

Directory of Open Access Journals (Sweden)

Adina COCU

2005-12-01

Full Text Available In intelligent tutoring systems, student or user modeling implies dealing with imperfect and uncertain knowledge. One of the artificial intelligence techniques used for uncertainty management is that of Bayesian networks. This paradigm is recommended in the situation when exist dependencies between data and qualitative information about these data. In this work we present a student knowledge diagnosis model based on representation with Bayesian networks. The educational system incorporate a multimedia interface for accomplishes the testing tools. The results of testing sessions are represented and interpreted with probability theory in order to ensure an adapted support for the student. The aims of the computer assisted application that contains this diagnose module are to support the student in personalized learning process and errors explanation.

Precautionary Borrowing and the Credit Card Debt Puzzle

DEFF Research Database (Denmark)

Druedahl, Jeppe; Jørgensen, Casper Nordal

2015-01-01

This paper addresses the credit card debt puzzle using a generalization of the buffer-stock consumption model with long-term revolving debt contracts. Closely resembling actual US credit card law, we assume that card issuers can always deny their cardholders access to new debt, but that they cannot...... to simultaneously hold positive gross debt and positive gross assets even though the interest rate on the debt is much higher than the return rate on the assets. Including a risk of being excluded from new borrowing which is positively correlated with unemployment, we are able to simultaneously explain...

Improving imperfect data from health management information systems in Africa using space-time geostatistics.

Directory of Open Access Journals (Sweden)

Peter W Gething

2006-06-01

Full Text Available Reliable and timely information on disease-specific treatment burdens within a health system is critical for the planning and monitoring of service provision. Health management information systems (HMIS exist to address this need at national scales across Africa but are failing to deliver adequate data because of widespread underreporting by health facilities. Faced with this inadequacy, vital public health decisions often rely on crudely adjusted regional and national estimates of treatment burdens.This study has taken the example of presumed malaria in outpatients within the largely incomplete Kenyan HMIS database and has defined a geostatistical modelling framework that can predict values for all data that are missing through space and time. The resulting complete set can then be used to define treatment burdens for presumed malaria at any level of spatial and temporal aggregation. Validation of the model has shown that these burdens are quantified to an acceptable level of accuracy at the district, provincial, and national scale.The modelling framework presented here provides, to our knowledge for the first time, reliable information from imperfect HMIS data to support evidence-based decision-making at national and sub-national levels.

INHERENT ASPECT: A SOCIOFUNCTIONALIST APPROACH OF PAST IMPERFECTIVE VERBAL FORMS IN SPANISH

Directory of Open Access Journals (Sweden)

Márluce Coan

2014-03-01

Full Text Available : We deal with the category aspect in a lexical dimension – an inherent aspect - and its interaction with the grammatical aspect, in order to inquire the convergences and divergences in the compositional shaping of the aspect. Our data come from twenty four short stories written in Spanish language, selected based on the cultural region parameter: Caribe; Mexico and Central America; Andes, Rio of the Prata; Chile and Spain. It was obtained a total of 2.093 data: 290 of them are imperfective periphrasis of past, that is, 13,85% of the total. These forms encode variably the descriptive, narrative, habitual and desiderative functions. The other identified functions – interactive, politeness, present, future, simultaneity, contrariety and playful – were only encoded by the imperfective past tense. The analysis of the correlation between the inherent aspect and the grammatical one corroborates the range of imperfectiviness by Givón (2001, which issupported by criteria of Vendler’s typology (2005 [1967]: states, the ones less marked and predicable, present more occurrences; followed at scale by activities, culminated processes, and culminations, the ones which are more marked and less predictable.

INHERENT ASPECT: A SOCIOFUNCTIONALIST APPROACH OF PAST IMPERFECTIVE VERBAL FORMS IN SPANISH

Directory of Open Access Journals (Sweden)

Márluce COAN

2013-12-01

Full Text Available We deal with the category aspect in a lexical dimension – an inherent aspect - and its interaction with the grammatical aspect, in order to inquire the convergences and divergences in the compositional shaping of the aspect. Our data come from twenty four short stories written in Spanish language, selected based on the cultural region parameter: Caribe; Mexico and Central America; Andes, Rio of the Prata; Chile and Spain. It was obtained a total of 2.093 data: 290 of them are imperfective periphrasis of past, that is, 13,85% of the total. These forms encode variably the descriptive, narrative, habitual and desiderative functions. The other identified functions – interactive, politeness, present, future, simultaneity, contrariety and playful – were only encoded by the imperfective past tense. The analysis of the correlation between the inherent aspect and the grammatical one corroborates the range of imperfectiviness by Givón (2001, which issupported by criteria of Vendler’s typology (2005 [1967]: states, the ones less marked and predicable, present more occurrences; followed at scale by activities, culminated processes, and culminations, the ones which are more marked and less predictable.

Method of fault diagnosis in nuclear power plant base on genetic algorithm and knowledge base

International Nuclear Information System (INIS)

Zhou Yangping; Zhao Bingquan

2000-01-01

Via using the knowledge base, combining Genetic Algorithm and classical probability and contraposing the characteristic of the fault diagnosis of NPP. The authors put forward a method of fault diagnosis. In the process of fault diagnosis, this method contact the state of NPP with the colony in GA and transform the colony to get the individual that adapts to the condition. On the 950MW full size simulator in Beijing NPP simulation training center, experimentation shows it has comparative adaptability to the imperfection of expert knowledge, illusive signal and other instance

The birth order puzzle.

Science.gov (United States)

Zajonc, R B; Markus, H; Markus, G B

1979-08-01

Studies relating intellectual performance to birth order report conflicting results, some finding intellectual scores to increase, others to decrease with birth order. In contrast, the relationship between intellectual performance and family size is stable and consistently replicable. Why do these two highly related variables generate such divergent results? This birth order puzzle is resolved by means of the confluence model that quantifies the influences upon intellectual growth arising within the family context. At the time of a new birth, two opposing influences act upon intellectual growth of the elder sibling: (a) his or her intellectual environment is "diluted" and (b) he or she loses the "last-born's handicap" and begins serving as an intellectual resource to the younger sibling. Since these opposite effects are not equal in magnitude, the differences in intellectual performance among birth ranks are shown to be age dependent. While elder children may surpass their younger siblings in intellectual performance at some ages, they may be overtaken by them at others. Thus when age is taken into consideration, the birth order literature loses its chaotic character and an orderly pattern of results emerges.

Fluctuation-induced forces in confined ideal and imperfect Bose gases

Science.gov (United States)

Diehl, H. W.; Rutkevich, Sergei B.

2017-06-01

Fluctuation-induced ("Casimir") forces caused by thermal and quantum fluctuations are investigated for ideal and imperfect Bose gases confined to d -dimensional films of size ∞d -1×D under periodic (P), antiperiodic (A), Dirichlet-Dirichlet (DD), Neumann-Neumann (NN), and Robin (R) boundary conditions (BCs). The full scaling functions ΥdBC(xλ=D /λth ,xξ=D /ξ ) of the residual reduced grand potential per area φres,dBC(T ,μ ,D ) =D-(d -1 )ΥdBC(xλ,xξ) are determined for the ideal gas case with these BCs, where λth and ξ are the thermal de Broglie wavelength and the bulk correlation length, respectively. The associated limiting scaling functions ΘdBC(xξ) ≡ΥdBC(∞ ,xξ) describing the critical behavior at the bulk condensation transition are shown to agree with those previously determined from a massive free O (2 ) theory for BC=P,A,DD,DN,NN . For d =3 , they are expressed in closed analytical form in terms of polylogarithms. The analogous scaling functions ΥdBC(xλ,xξ,c1D ,c2D ) and ΘdR(xξ,c1D ,c2D ) under the RBCs (∂z-c1) ϕ |z=0=(∂z+c2) ϕ | z =D=0 with c1≥0 and c2≥0 are also determined. The corresponding scaling functions Υ∞,d P(xλ,xξ) and Θ∞,d P(xξ) for the imperfect Bose gas are shown to agree with those of the interacting Bose gas with n internal degrees of freedom in the limit n →∞ . Hence, for d =3 , Θ∞,d P(xξ) is known exactly in closed analytic form. To account for the breakdown of translation invariance in the direction perpendicular to the boundary planes implied by free BCs such as DDBCs, a modified imperfect Bose gas model is introduced that corresponds to the limit n →∞ of this interacting Bose gas. Numerically and analytically exact results for the scaling function Θ∞,3 DD(xξ) therefore follow from those of the O (2 n ) ϕ4 model for n →∞ .

Electric vehicles in imperfect electricity markets: The case of Germany

International Nuclear Information System (INIS)

Schill, Wolf-Peter

2011-01-01

We use a game-theoretic model to analyze the impacts of a hypothetical fleet of plug-in electric vehicles on the imperfectly competitive German electricity market. Electric vehicles bring both additional demand and additional storage capacity to the market. We determine the effects on prices, welfare, and electricity generation for various cases with different players in charge of vehicle operations. Vehicle loading increases generator profits, but decreases consumer surplus in the power market. If excess vehicle batteries can be used for storage, welfare results are reversed: generating firms suffer from the price-smoothing effect of additional storage, whereas power consumers benefit despite increasing overall demand. Strategic players tend to under-utilize the storage capacity of the vehicle fleet, which may have negative welfare implications. In contrast, we find a market power-mitigating effect of electric vehicle recharging on oligopolistic generators. Overall, electric vehicles are unlikely to be a relevant source of market power in Germany in the foreseeable future. - Highlights: → We study the effect of electric vehicles on an imperfectly competitive electricity market. → We apply a game-theoretic model to the German market. → There is a market power-mitigating effect of vehicle loading on oligopolistic generating firms. → Consumers benefit from electric vehicles if excess battery capacity can be used for grid storage. → Electric vehicles are unlikely to be a source of market power in Germany in the near future.

Optimizing production and imperfect preventive maintenance planning's integration in failure-prone manufacturing systems

International Nuclear Information System (INIS)

Aghezzaf, El-Houssaine; Khatab, Abdelhakim; Tam, Phuoc Le

2016-01-01

This paper investigates the issue of integrating production and maintenance planning in a failure-prone manufacturing system. It is assumed that the system's operating state is stochastically predictable, in terms of its operating age, and that it can accordingly be preventively maintained during preplanned periods. Preventive maintenance is assumed to be imperfect, that is when performed, it brings the manufacturing system to an operating state that lies between ‘as bad as old’ and ‘as good as new’. Only an overhauling of the system brings it to a ‘as good as new’ operating state again. A practical integrated production and preventive maintenance planning model, that takes into account the system's manufacturing capacity and its operational reliability state, is developed. The model is naturally formulated as a mixed-integer non-linear optimization problem, for which an extended mixed-integer linear reformulation is proposed. This reformulation, while it solves the proposed integrated planning problem to optimality, remains quite demanding in terms of computational time. A fix-and-optimize procedure, that takes advantage of some properties of the original model, is then proposed. The reformulation and the fix-and-optimize procedure are tested on some test instances adapted from those available in the literature. The results show that the proposed fix-and-optimize procedure performs quite well and opens new research direction for future improvements. - Highlights: • Integration of production planning and imperfect preventive maintenance is explored. • Imperfect maintenance is modeled using a fitting age reduction hybrid hazard rate. • A practical approximate optimization model for this integration is proposed. • The resulting naturally MINL optimization model is reformulated and solved as a MILP. • An effective fix-and-optimize procedure is proposed for large instances of this MILP.

Does Intrinsic Habit Formation Actually Resolve the Equity Premium Puzzle?

OpenAIRE

David A. Chapman

2002-01-01

Constantinides (1990) describes a simple model of intrinsic habit formation that appears to resolve the "equity premium puzzle" of Mehra and Prescott (1985). This finding is particularly important, since it has motivated a broader consideration of the implications of habit formation preferences in dynamic equilibrium models. However, consumption growth actually behaves very differently pre- and post-1948, and the explanatory power of the habit formation model is driven by the pre-1948 data. U...

Puzzling with potential: dynamic testing of analogical reasoning in children

OpenAIRE

Stevenson, Claire Elisabeth

2012-01-01

Assessment procedures are frequent in children's school careers; however, measuring potential for learning has remained a puzzle. Dynamic testing is a method to assess cognitive potential that includes training in the assessment process. The goal of this thesis project was to develop a new dynamic test of analogical reasoning for school children. The main aims were to (1) investigate factors that influence children’s differences in performance and change during dynamic testing and (2) examine...

Puzzles, paradoxes, and problem solving an introduction to mathematical thinking

CERN Document Server

Reba, Marilyn A

2014-01-01

Graphs: Puzzles and Optimization Graphical Representation and Search Greedy Algorithms and Dynamic Programming Shortest Paths, DNA Sequences, and GPS Systems Routing Problems and Optimal Circuits Traveling Salesmen and Optimal Orderings Vertex Colorings and Edge Matchings Logic: Rational Inference and Computer Circuits Inductive and Deductive Arguments Deductive Arguments and Truth-Tables Deductive Arguments and Derivations Deductive Logic and Equivalence Modeling Using Deductive Logic Probability: Predictions and Expectations Probability and Counting Counting and Unordered Outcomes Independen

Multi-state systems with selective propagated failures and imperfect individual and group protections

International Nuclear Information System (INIS)

Levitin, Gregory; Xing Liudong; Ben-Haim, Hanoch; Da, Yuanshun

2011-01-01

The paper presents an algorithm for evaluating performance distribution of complex series–parallel multi-state systems with propagated failures and imperfect protections. The failure propagation can have a selective effect, which means that the failures originated from different system elements can cause failures of different subsets of elements. Individual elements or some disjoint groups of elements can be protected from propagation of failures originated outside the group. The protections can fail with given probabilities. The suggested algorithm is based on the universal generating function approach and a generalized reliability block diagram method. The performance distribution evaluation procedure is repeated for each combination of propagated failures and protection failures. Both an analytical example and a numerical example are provided to illustrate the suggested algorithm. - Highlights: ► Systems with propagated failures and imperfect protections are considered. ► Failures originated from different elements can affect different subsets of elements. ► Protections of individual elements or groups of elements can fail with given probabilities. ► An algorithm for evaluating multi-state system performance distribution is suggested.

Optimization and maintenance tests considering multiple failure modes, aging and imperfect maintenance

International Nuclear Information System (INIS)

Martorell, S.; Marton, I.; Sanchez, A.; Carlos, S.

2014-01-01

The paper focuses on the optimization of the test and maintenance intervals under the criteria of unavailability or cost including the effect of the aging of the components and models of imperfect maintenance. The results obtained in the case of application, which focuses on a system of safety of a nuclear power station, show differences, mainly in the outage when you consider the aging. (Author)

Prediction of vibration characteristics of a planar mechanism having imperfect joints using neural network

International Nuclear Information System (INIS)

Erkaya, Selcuk

2012-01-01

Clearance is inevitable in the joints of mechanisms due primarily to the design, manufacturing and assembly processes or a wear effect. Excessive value of joint clearance plays a crucial role and has a significant effect on the kinematic and dynamic performances of the mechanism. In this study, effects of joint clearances on bearing vibrations of mechanism are investigated. An experimental test rig is set up, and a planar slider-crank mechanism having two imperfect joints with radial clearance is used as a model mechanism. Three accelerometers are positioned at different points to measure the bearing vibrations during the mechanism motion. For the different running speeds and clearance sizes, this work provides a neural model to predict and estimate the bearing vibrations of the mechanical systems having imperfect joints. The results show that radial basis function (RBF) neural network has a superior performance for predicting and estimating the vibration characteristics of the mechanical system

Climate agreements under limited participation, asymmetric information and market imperfections

Energy Technology Data Exchange (ETDEWEB)

Hagem, Cathrine

1996-12-31

This thesis relates to climate agreements and cost efficiency by analysing the formation of a system of quota leading to distributed discharge of emissions between countries. Main fields concerned are the greenhouse effect, the political process, efficient and cost-effective climate agreements, and climate agreements under limited participation, asymmetric information and market imperfections covering fields like limited participation in climate agreements, limited participation and indirect impact on non-participating countries` emissions, limited participation and direct impact on non-participating countries` emissions under asymmetric information, and non-competitive market for tradeable quotas. 166 refs., 7 tabs.

Asset prices and rents in a GE model with imperfect competition

OpenAIRE

Pierre Lafourcade

2003-01-01

This paper analyses the general equilibrium effects on asset valuation and capital accumulation of an exogenous drop in the rate of return required by investors in a model of production with imperfectly competitive product markets. The model improves substantially on the standard perfectly competitive neo-classical framework, by dissociating the behavior of marginal and average q. It tracks more closely current observed data on the ratio of stock-market value to the economy's capital base, wh...

Drag Induced by Flat-Plate Imperfections in Compressible Turbulent Flow Regimes

OpenAIRE

Molton , Pascal; Hue , David; Bur , Reynald

2014-01-01

International audience; This paper presents the results of a coupled experimental and numerical study aimed at evaluating the influence of typical aircraft surface imperfections on the flat-plate drag production in fully turbulent conditions. A test campaign involving high-level measurement techniques, such as microdrag evaluation, near-wall laser Doppler velocimetry, and oil-film interferometry, has been carried out at several Mach numbers from 0.5 to 1.3 to quantify the impact of a large ra...

Analysis of resonance-driving imperfections in the AGS Booster

International Nuclear Information System (INIS)

Gardner, C.; Shoji, Y.; Danby, G.; Glenn, J.W.; Jackson, G.J.; Soukas, A.; van Asselt, W.; Whalen, C.

1994-01-01

At the design intensity of 1.5 x 10 13 ppp, the space charge tune shift in the AGS Booster at injection has been estimated to be about 0.35. The beam tunes are therefore spread over many lower order resonance lines and the associated stopbands must be corrected in order to minimize the amplitude growth due to resonance excitation. This requires proper compensation of the resonance-driving harmonics which result from random magnetic field errors. The observation and correction of second and third order resonance stopbands in the AGS Booster is reviewed, and an analysis of magnetic field imperfections based on the required corrections is given

New Nuclear Magnetic Moment of 209Bi: Resolving the Bismuth Hyperfine Puzzle

Science.gov (United States)

Skripnikov, Leonid V.; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F.; Scheibe, Benjamin; Shabaev, Vladimir M.; Vogel, Michael; Volotka, Andrey V.

2018-03-01

A recent measurement of the hyperfine splitting in the ground state of Li-like 80+208Bi has established a "hyperfine puzzle"—the experimental result exhibits a 7 σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017), 10.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017), 10.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μI) of 209Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μI(209ipts>) and combine it with nuclear magnetic resonance measurements of Bi (NO3 )3 in nitric acid solutions and of the hexafluoridobismuthate(V) BiF6- ion in acetonitrile. The result clearly reveals that μI(209Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

New Nuclear Magnetic Moment of ^{209}Bi: Resolving the Bismuth Hyperfine Puzzle.

Science.gov (United States)

Skripnikov, Leonid V; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F; Scheibe, Benjamin; Shabaev, Vladimir M; Vogel, Michael; Volotka, Andrey V

2018-03-02

A recent measurement of the hyperfine splitting in the ground state of Li-like ^{208}Bi^{80+} has established a "hyperfine puzzle"-the experimental result exhibits a 7σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017)NCAOBW2041-172310.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017)NPAHAX1745-247310.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μ_{I}) of ^{209}Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μ_{I}(^{209}Bi) and combine it with nuclear magnetic resonance measurements of Bi(NO_{3})_{3} in nitric acid solutions and of the hexafluoridobismuthate(V) BiF_{6}^{-} ion in acetonitrile. The result clearly reveals that μ_{I}(^{209}Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

The puzzle of the 6Li quadrupole moment: steps toward the solution

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Kukulin, V.I.; Pomerantsev, V.N.

2005-01-01

The problem of origin of the ground-state 6 Li quadrupole deformation has been investigated with account of the three-deuteron component of this nucleus wave function. two long-standing puzzles related to the tensor interaction in 6 Li are known. The first one lies in the anomalously small value of the 6 Li quadrupole moment which, being negative, is in absolute magnitude smaller by the factor of 5 than that of 6 Li. The second puzzle consists in the anomalous behavior of the tensor analyzing power T 2q in scattering of polarized 6 Li nuclei from various targets. It is shown that the large (in absolute magnitude) negative contribution to the 6 Li quadrupole moment resulting from the three-deuteron configuration cancels almost completely the direct positive contribution due to the folding αd-potential. As a result, the total quadrupole moment turns out to be close to zero and highly sensitive to fine details of the tensor NN interaction and of the 4 He wave function [ru

Chinese American and Caucasian American Family Interaction Patterns in Spatial Rotation Puzzle Solutions.

Science.gov (United States)

Hutsinger, Carol S.; Jose, Paul E.

1995-01-01

Examined sociocultural influences on mathematics achievement. First generation Chinese American and Caucasian American mother-father-daughter triads were audiotaped as the fifth- and sixth-grade girls solved a spatial puzzle. Chinese American triads were quieter, more respectful, more serious, and more orderly, whereas Caucasian American triads…

Review of Experimental and Theoretical Status of the Proton Radius Puzzle

Energy Technology Data Exchange (ETDEWEB)

Hill, Richard J. [TRIUMF

2017-01-01

The discrepancy between the measured Lamb shift in muonic hydrogen and expectations from electron-proton scattering and regular hydrogen spectroscopy has become known as the proton radius puzzle, whose most “mundane” resolution requires a > 5σ shift in the value of the fundamental Rydberg constant. I briefly review the status of spectroscopic and scattering measurements, recent theoretical developments, and implications for fundamental physics.

Impact of interfacial imperfection on transverse wave in a functionally graded piezoelectric material structure with corrugated boundaries

Science.gov (United States)

Kumar Singh, Abhishek; Kumar, Santan; Kumari, Richa

2018-03-01

The propagation behavior of Love-type wave in a corrugated functionally graded piezoelectric material layered structure has been taken into account. Concretely, the layered structure incorporates a corrugated functionally graded piezoelectric material layer imperfectly bonded to a functionally graded piezoelectric material half-space. An analytical treatment has been employed to determine the dispersion relation for both cases of electrically open condition and electrically short condition. The phase velocity of the Love-type wave has been computed numerically and its dependence on the wave number has been depicted graphically for a specific type of corrugated boundary surfaces for both said conditions. The crux of the study lies in the fact that the imperfect bonding of the interface, the corrugated boundaries present in the layer, and the material properties of the layer and the half-space strongly influence the phase velocity of the Love-type wave. It can be remarkably noted that the imperfect bonding of the interface reduces the phase velocity of the Love-type wave significantly. As a special case of the problem, it is noticed that the procured dispersion relation for both cases of electrically open and electrically short conditions is in accordance with the classical Love wave equation.

Puzzle of magnetic moments of Ni clusters revisited using quantum Monte Carlo method.

Science.gov (United States)

Lee, Hung-Wen; Chang, Chun-Ming; Hsing, Cheng-Rong

2017-02-28

The puzzle of the magnetic moments of small nickel clusters arises from the discrepancy between values predicted using density functional theory (DFT) and experimental measurements. Traditional DFT approaches underestimate the magnetic moments of nickel clusters. Two fundamental problems are associated with this puzzle, namely, calculating the exchange-correlation interaction accurately and determining the global minimum structures of the clusters. Theoretically, the two problems can be solved using quantum Monte Carlo (QMC) calculations and the ab initio random structure searching (AIRSS) method correspondingly. Therefore, we combined the fixed-moment AIRSS and QMC methods to investigate the magnetic properties of Ni n (n = 5-9) clusters. The spin moments of the diffusion Monte Carlo (DMC) ground states are higher than those of the Perdew-Burke-Ernzerhof ground states and, in the case of Ni 8-9 , two new ground-state structures have been discovered using the DMC calculations. The predicted results are closer to the experimental findings, unlike the results predicted in previous standard DFT studies.

Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression and fragmentation.

Science.gov (United States)

Djordjevic, Magdalena

2014-01-31

Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultrarelativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which--contrary to pQCD expectations--may suggest similar energy losses for light quarks and gluons in the QCD medium. We here use our recently developed energy loss formalism in a finite-size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC." We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns and, in fact, does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of charged hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data.

Investigation on imperfection sensitivity of composite cylindrical shells using the nonlinearity reduction technique and the polynomial chaos method

Science.gov (United States)

Liang, Ke; Sun, Qin; Liu, Xiaoran

2018-05-01

The theoretical buckling load of a perfect cylinder must be reduced by a knock-down factor to account for structural imperfections. The EU project DESICOS proposed a new robust design for imperfection-sensitive composite cylindrical shells using the combination of deterministic and stochastic simulations, however the high computational complexity seriously affects its wider application in aerospace structures design. In this paper, the nonlinearity reduction technique and the polynomial chaos method are implemented into the robust design process, to significantly lower computational costs. The modified Newton-type Koiter-Newton approach which largely reduces the number of degrees of freedom in the nonlinear finite element model, serves as the nonlinear buckling solver to trace the equilibrium paths of geometrically nonlinear structures efficiently. The non-intrusive polynomial chaos method provides the buckling load with an approximate chaos response surface with respect to imperfections and uses buckling solver codes as black boxes. A fast large-sample study can be applied using the approximate chaos response surface to achieve probability characteristics of buckling loads. The performance of the method in terms of reliability, accuracy and computational effort is demonstrated with an unstiffened CFRP cylinder.

The Puzzle of Non-proliferation and Disarmament (Part II)

International Nuclear Information System (INIS)

Ponga, J. de

2011-01-01

Since, in 1945, the World was aware of the devastating power of nuclear weapons there have been many initiatives at international level to avoid nuclear weapon proliferation: the foundation of the IAEA, the NPT, the Safeguards Agreements, the Nuclear Weapon Free Zones, the treaties banning nuclear tests or the export control regime of the NSG, among others. This article aims to offer a general picture of all of them as pieces of a puzzle the purpose of which is not to allow gaps to non pacific uses of nuclear energy. (Author)

Imperfect repair and lifesaving in heterogeneous populations

Energy Technology Data Exchange (ETDEWEB)

Finkelstein, Maxim [Department of Mathematical Statistics, University of the Free State, PO Box 339, 9300 Bloemfontein (South Africa) and Max Planck Institute for Demographic Research, Rostock (Germany)]. E-mail: FinkelM.SCl@mail.uovs.ac.za

2007-12-15

In this theoretical paper we generalize the notion of minimal repair to the heterogeneous case, when the lifetime distribution function can be modeled by continuous or a discrete mixture of distributions. The statistical (black box) minimal repair and the minimal repair based on information just before the failure of an object are considered. The corresponding failure (intensity) rate processes are defined and analyzed. Demographic lifesaving model is also considered: each life is saved (cured) with some probability (or equivalently a proportion of individuals who would have died are now resuscitated and given another chance). Those who are saved experience the statistical minimal repair. Both of these models are based on the Poisson or non-homogeneous Poisson processes of underlying events, which allow for considering heterogeneity. We also consider the new model of imperfect repair in the homogeneous case and present generalizations to the heterogeneous setting.

Transmit selection algorithms for imperfect threshold-based receive MRC in the presence of co-channel interference

KAUST Repository

Radaydeh, Redha Mahmoud Mesleh; Alouini, Mohamed-Slim

2010-01-01

The performance of transmit antenna selection for threshold-based maximal ratio combining (MRC) diversity receivers in the presence of multiple co-channel interfering signals is studied. The impact of imperfect channel estimation of desired user

Sex and the Imperfect Fungi.

Science.gov (United States)

Dyer, Paul S; Kück, Ulrich

2017-06-01

Approximately 20% of species in the fungal kingdom are only known to reproduce by asexual means despite the many supposed advantages of sexual reproduction. However, in recent years, sexual cycles have been induced in a series of emblematic "asexual" species. We describe how these discoveries were made, building on observations of evidence for sexual potential or "cryptic sexuality" from population genetic analyses; the presence, distribution, and functionality of mating-type genes; genome analyses revealing the presence of genes linked to sexuality; the functionality of sex-related genes; and formation of sex-related developmental structures. We then describe specific studies that led to the discovery of mating and sex in certain Candida , Aspergillus , Penicillium , and Trichoderma species and discuss the implications of sex including the beneficial exploitation of the sexual cycle. We next consider whether there might be any truly asexual fungal species. We suggest that, although rare, imperfect fungi may genuinely be present in nature and that certain human activities, combined with the genetic flexibility that is a hallmark of the fungal kingdom, might favor the evolution of asexuality under certain conditions. Finally, we argue that fungal species should not be thought of as simply asexual or sexual, but rather as being composed of isolates on a continuum of sexual fertility.

A resolution of the inclusive flavor-breaking τ |Vus| puzzle

Science.gov (United States)

Hudspith, Renwick J.; Lewis, Randy; Maltman, Kim; Zanotti, James

2018-06-01

We revisit the puzzle of |Vus | values obtained from the conventional implementation of hadronic-τ- decay-based flavor-breaking finite-energy sum rules lying > 3 σ below the expectations of three-family unitarity. Significant unphysical dependences of |Vus | on the choice of weight, w, and upper limit, s0, of the experimental spectral integrals entering the analysis are confirmed, and a breakdown of assumptions made in estimating higher dimension, D > 4, OPE contributions identified as the main source of these problems. A combination of continuum and lattice results is shown to suggest a new implementation of the flavor-breaking sum rule approach in which not only |Vus |, but also D > 4 effective condensates, are fit to data. Lattice results are also used to clarify how to reliably treat the slowly converging D = 2 OPE series. The new sum rule implementation is shown to cure the problems of the unphysical w- and s0-dependence of |Vus | and to produce results ∼0.0020 higher than those of the conventional implementation employing the same data. With B-factory input, and using, in addition, dispersively constrained results for the Kπ branching fractions, we find |Vus | = 0.2231(27)exp(4)th, in excellent agreement with the result from Kℓ3, and compatible within errors with the expectations of three-family unitarity, thus resolving the long-standing inclusive τ |Vus | puzzle.

Imperfectly geometric shapes of nanograting structures as solar absorbers with superior performance for solar cells.

Science.gov (United States)

Nguyen-Huu, Nghia; Cada, Michael; Pištora, Jaromír

2014-03-10

The expectation of perfectly geometric shapes of subwavelength grating (SWG) structures such as smoothness of sidewalls and sharp corners and nonexistence of grating defects is not realistic due to micro/nanofabrication processes. This work numerically investigates optical properties of an optimal solar absorber comprising a single-layered silicon (Si) SWG deposited on a finite Si substrate, with a careful consideration given to effects of various types of its imperfect geometry. The absorptance spectra of the solar absorber with different geometric shapes, namely, the grating with attached nanometer-sized features at the top and bottom of sidewalls and periodic defects within four and ten grating periods are investigated comprehensively. It is found that the grating with attached features at the bottom absorbs more energy than both the one at the top and the perfect grating. In addition, it is shown that the grating with defects in each fourth period exhibits the highest average absorptance (91%) compared with that of the grating having defects in each tenth period (89%), the grating with attached features (89%), and the perfect one (86%). Moreover, the results indicate that the absorptance spectrum of the imperfect structures is insensitive to angles of incidence. Furthermore, the absorptance enhancement is clearly demonstrated by computing magnetic field, energy density, and Poynting vector distributions. The results presented in this study prove that imperfect geometries of the nanograting structure display a higher absorptance than the perfect one, and provide such a practical guideline for nanofabrication capabilities necessary to be considered by structure designers.

An Analysis of Closed-end Fund Puzzle for Emerging Capital Markets

Directory of Open Access Journals (Sweden)

Victor Dragota

2008-10-01

Full Text Available This paper analyzes the closed-end fund puzzle for an emerging capital market, respectively the Romanian one. Comparatively to more developed markets, as long as small markets are often very illiquid, it has to be used some specific valuation techniques in order to estimate the market values for closed-end funds. Also, one problem is this estimation can be made only in some (punctual moments.

Marginal CO2 cost pass-through under imperfect competition in power markets

International Nuclear Information System (INIS)

Chernyavs'ka, Liliya; Gulli, Francesco

2008-01-01

In line with economic theory, carbon ETS determines a rise in marginal cost equal to the carbon opportunity cost regardless of whether carbon allowances are allocated free of charge or not. This paper aims at evaluating to what extent firms in imperfectly competitive markets will pass-through into electricity prices the increase in cost. By using the load duration curve approach and the dominant firm with competitive fringe model, we show that the result is ambiguous. The increase in price can be either lower or higher than the marginal CO 2 cost, depending on several structural factors: the degree of market concentration, the available capacity (whether there is excess capacity or not), the power plant mix in the market and the power demand level (peak vs. off-peak hours). The empirical analysis of the Italian context (an emblematic case of imperfectly competitive market), which can be split into four sub-markets with different structural features, provides a contribution supporting the model predictions. Market power, therefore, would determine a significant deviation from the 'full pass-through' rule but we cannot know the sign of this deviation, a priori, i.e. without before taking carefully into account the structural features of the power market. (author)

SOLVING THE PUZZLE OF SUBHALO SPINS

Energy Technology Data Exchange (ETDEWEB)

Wang, Yang; Lin, Weipeng [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Shanghai 200030 (China); Pearce, Frazer R.; Lux, Hanni; Onions, Julian [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Muldrew, Stuart I., E-mail: wangyang@shao.ac.cn, E-mail: linwp@shao.ac.cn [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom)

2015-03-10

Investigating the spin parameter distribution of subhalos in two high-resolution isolated halo simulations, recent work by Onions et al. suggested that typical subhalo spins are consistently lower than the spin distribution found for field halos. To further examine this puzzle, we have analyzed simulations of a cosmological volume with sufficient resolution to resolve a significant subhalo population. We confirm the result of Onions et al. and show that the typical spin of a subhalo decreases with decreasing mass and increasing proximity to the host halo center. We interpret this as the growing influence of tidal stripping in removing the outer layers, and hence the higher angular momentum particles, of the subhalos as they move within the host potential. Investigating the redshift dependence of this effect, we find that the typical subhalo spin is smaller with decreasing redshift. This indicates a temporal evolution, as expected in the tidal stripping scenario.

Resolutions of Several Puzzles at Intermediate pT and Recent Developments in Correlation

International Nuclear Information System (INIS)

Hwa, Rudolph C.

2006-01-01

Some of the puzzles on hadron production at intermediate p T found at RHIC are explained as natural consequences of parton recombination. In that framework for hadronization the correlation among hadrons produced in jets can be calculated. Some new results on both near-side and away-side jet structures are presented

Induced mutation and somatic recombination as tools for genetic analysis and breeding of imperfect fungi

NARCIS (Netherlands)

Bos, C.J.

1986-01-01

Many fungi which are important in Agriculture as plant pathogens or in Biotechnology as producers of organic acids, antibiotics or enzymes, are imperfect fungi. These fungi do not have a sexual stage, which implies that they lack a meiotic recombination mechanism.

However, many

Optimal control of an invasive species with imperfect information about the level of infestation

Science.gov (United States)

Robert G. Haight; Stephen. Polasky

2010-01-01

The presence of invasive species is often not realized until well after the species becomes established. Discovering the location and extent of infestation before the invasive species causes widespread damage typically requires intensive monitoring efforts. In this paper, we analyze the problem of controlling an invasive species when there is imperfect information...

Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

Directory of Open Access Journals (Sweden)

Ji Chen

2016-01-01

Full Text Available We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

Can the consumption-free nonexpected utility model solve the risk premium puzzle? An empirical study of the Japanese stock market

OpenAIRE

Kang, Myong-Il

2010-01-01

This paper investigates whether the consumption-free two-beta intertemporal capital asset-pricing model developed by Campbell and Vuolteenaho (2004) is able to solve the risk premium puzzle in the Japanese stock market over the period 1984-2002. Using the cash flow and discount rate betas as risk factors, the model is able to explain about half of the market returns by selection of suitable vector autoregression variables. On this basis, the model proposed solves the risk premium puzzle in Ja...

Bias in logistic regression due to imperfect diagnostic test results and practical correction approaches.

Science.gov (United States)

Valle, Denis; Lima, Joanna M Tucker; Millar, Justin; Amratia, Punam; Haque, Ubydul

2015-11-04

Logistic regression is a statistical model widely used in cross-sectional and cohort studies to identify and quantify the effects of potential disease risk factors. However, the impact of imperfect tests on adjusted odds ratios (and thus on the identification of risk factors) is under-appreciated. The purpose of this article is to draw attention to the problem associated with modelling imperfect diagnostic tests, and propose simple Bayesian models to adequately address this issue. A systematic literature review was conducted to determine the proportion of malaria studies that appropriately accounted for false-negatives/false-positives in a logistic regression setting. Inference from the standard logistic regression was also compared with that from three proposed Bayesian models using simulations and malaria data from the western Brazilian Amazon. A systematic literature review suggests that malaria epidemiologists are largely unaware of the problem of using logistic regression to model imperfect diagnostic test results. Simulation results reveal that statistical inference can be substantially improved when using the proposed Bayesian models versus the standard logistic regression. Finally, analysis of original malaria data with one of the proposed Bayesian models reveals that microscopy sensitivity is strongly influenced by how long people have lived in the study region, and an important risk factor (i.e., participation in forest extractivism) is identified that would have been missed by standard logistic regression. Given the numerous diagnostic methods employed by malaria researchers and the ubiquitous use of logistic regression to model the results of these diagnostic tests, this paper provides critical guidelines to improve data analysis practice in the presence of misclassification error. Easy-to-use code that can be readily adapted to WinBUGS is provided, enabling straightforward implementation of the proposed Bayesian models.

The Imperfect Fluid behind Kinetic Gravity Braiding

CERN Document Server

Pujolas, Oriol; Vikman, Alexander

2011-01-01

We present a standard hydrodynamical description for non-canonical scalar field theories with kinetic gravity braiding. In particular, this picture applies to the simplest galileons and k-essence. The fluid variables not only have a clear physical meaning but also drastically simplify the analysis of the system. The fluid carries charges corresponding to shifts in field space. This shift-charge current contains a spatial part responsible for diffusion of the charges. Moreover, in the incompressible limit, the equation of motion becomes the standard diffusion equation. The fluid is indeed imperfect because the energy flows neither along the field gradient nor along the shift current. The fluid has zero vorticity and is not dissipative: there is no entropy production, the energy-momentum is exactly conserved, the temperature vanishes and there is no shear viscosity. Still, in an expansion around a perfect fluid one can identify terms which correct the pressure in the manner of bulk viscosity. We close by formul...

The paradox of imperfect duty in Kant's moral philosophy: A problem in 'applying' ethics'

Directory of Open Access Journals (Sweden)

Richter Phillip

2015-01-01

Full Text Available The Applied Ethics debate has not yet sufficiently clarified what application of ethics exactly is. The issue of application is considered to be especially problematic in Kantian ethics or in discourse ethics. This article describes the concept of applying ethics in Kant. In discussing the duty of helping others and the theory of its application in Metaphysics of Morals it is shown that a strict separation of justification and application in ethical theory results in the paradox of imperfect duty. The paradox says that the duty to help others would be fulfilled without ever being fulfilled in action. To overcome the paradox it is necessary to form submaximes of helping, which are not arbitrarily but instructed by a theory of casuistry. This casuistry, if it is considered as a doctrine of application in Kantian ethics, can overcome the paradox of imperfect duty. However, the casuistry can overcome this paradox only if it is understood as a philosophy of prudence, which can be found in Aristotle or Descartes.

Clarifying some remaining questions in the anomaly puzzle

International Nuclear Information System (INIS)

Huang, Xing; Parker, Leonard

2011-01-01

We discuss several points that may help to clarify some questions that remain about the anomaly puzzle in supersymmetric theories. In particular, we consider a general N=1 supersymmetric Yang-Mills theory. The anomaly puzzle concerns the question of whether there is a consistent way in the quantized theory to put the R-current and the stress tensor in a single supermultiplet called the supercurrent, even though in the classical theory they are in the same supermultiplet. It was proposed that the classically conserved supercurrent bifurcates into two supercurrents having different anomalies in the quantum regime. The most interesting result we obtain is an explicit expression for the lowest component of one of the two supercurrents in 4-dimensional spacetime, namely the supercurrent that has the energy-momentum tensor as one of its components. This expression for the lowest component is an energy-dependent linear combination of two chiral currents, which itself does not correspond to a classically conserved chiral current. The lowest component of the other supercurrent, namely, the R-current, satisfies the Adler-Bardeen theorem. The lowest component of the first supercurrent has an anomaly, which we show is consistent with the anomaly of the trace of the energy-momentum tensor. Therefore, we conclude that there is no consistent way to construct a single supercurrent multiplet that contains the R-current and the stress tensor in the straightforward way originally proposed. We also discuss and try to clarify some technical points in the derivations of the two supercurrents in the literature. These latter points concern the significance of infrared contributions to the NSVZ β-function and the role of the equations of motion in deriving the two supercurrents. (orig.)

COMPARISON OF EIGENMODE-BASED AND RANDOM FIELD-BASED IMPERFECTION MODELING FOR THE STOCHASTIC BUCKLING ANALYSIS OF I-SECTION BEAM–COLUMNS

KAUST Repository

STAVREV, A.

2013-03-01

The uncertainty of geometric imperfections in a series of nominally equal I-beams leads to a variability of corresponding buckling loads. Its analysis requires a stochastic imperfection model, which can be derived either by the simple variation of the critical eigenmode with a scalar random variable, or with the help of the more advanced theory of random fields. The present paper first provides a concise review of the two different modeling approaches, covering theoretical background, assumptions and calibration, and illustrates their integration into commercial finite element software to conduct stochastic buckling analyses with the Monte-Carlo method. The stochastic buckling behavior of an example beam is then simulated with both stochastic models, calibrated from corresponding imperfection measurements. The simulation results show that for different load cases, the response statistics of the buckling load obtained with the eigenmode-based and the random field-based models agree very well. A comparison of our simulation results with corresponding Eurocode 3 limit loads indicates that the design standard is very conservative for compression dominated load cases. © 2013 World Scientific Publishing Company.

Exciting imperfection. Real-structure effects in magnesium-, cadmium-, and zinc-oxide

Energy Technology Data Exchange (ETDEWEB)

Schleife, Andre

2010-07-01

We employ recent ab-initio methods and theoretical spectroscopy techniques that rely on heavy numerical calculations to describe electronic excitations in non-ideal crystals of three group-II oxides. We study the ideal equilibrium polymorphs of these oxides, for gaining a thorough understanding as well as the necessary confidence in our approaches to generalize and apply them to the electronic excitations in imperfect crystals. As such imperfections we take the influence of strain, the alloying of the different oxides, an intrinsic point defect, and free electrons in the lowest conduction band into account. We employ the DFT results as input in order to compute quasiparticle electronic structures, which are in good agreement with experimental findings. According to Hedin's equations for interacting electrons, the electron-hole interaction is taken into account by solving a Bethe-Salpeter equation for the polarization function. Thereafter the equilibrium polymorphs of ideal bulk MgO, ZnO, and CdO and investigates the structure of their valence and conduction bands are described. We present densities of states and effective masses, as well as natural band discontinuities. Furthermore, our description of the dielectric function, which takes excitonic effects into account, enables us to derive the electron-energy loss function. The influence of uniaxial and biaxial strain on the ordering of the valence bands in ZnO is investigated. In addition, we explore the electronic band structure of the non-equilibrium wurtzite structures of MgO and CdO. We predict valence-band splittings and band gaps as they might occur at interfaces of Mgo or CdO with ZnO substrates. Thereafter we study pseudobinary alloys by means of a cluster expansion method. Due to the different crystal structures of the respective oxides, i.e. rocksalt and wurtzite, the description of their heterostructural combination has to be achieved. The electronic and optical properties of the group-II oxide

Exciting imperfection. Real-structure effects in magnesium-, cadmium-, and zinc-oxide

International Nuclear Information System (INIS)

Schleife, Andre

2010-01-01

We employ recent ab-initio methods and theoretical spectroscopy techniques that rely on heavy numerical calculations to describe electronic excitations in non-ideal crystals of three group-II oxides. We study the ideal equilibrium polymorphs of these oxides, for gaining a thorough understanding as well as the necessary confidence in our approaches to generalize and apply them to the electronic excitations in imperfect crystals. As such imperfections we take the influence of strain, the alloying of the different oxides, an intrinsic point defect, and free electrons in the lowest conduction band into account. We employ the DFT results as input in order to compute quasiparticle electronic structures, which are in good agreement with experimental findings. According to Hedin's equations for interacting electrons, the electron-hole interaction is taken into account by solving a Bethe-Salpeter equation for the polarization function. Thereafter the equilibrium polymorphs of ideal bulk MgO, ZnO, and CdO and investigates the structure of their valence and conduction bands are described. We present densities of states and effective masses, as well as natural band discontinuities. Furthermore, our description of the dielectric function, which takes excitonic effects into account, enables us to derive the electron-energy loss function. The influence of uniaxial and biaxial strain on the ordering of the valence bands in ZnO is investigated. In addition, we explore the electronic band structure of the non-equilibrium wurtzite structures of MgO and CdO. We predict valence-band splittings and band gaps as they might occur at interfaces of Mgo or CdO with ZnO substrates. Thereafter we study pseudobinary alloys by means of a cluster expansion method. Due to the different crystal structures of the respective oxides, i.e. rocksalt and wurtzite, the description of their heterostructural combination has to be achieved. The electronic and optical properties of the group-II oxide alloys

Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

Energy Technology Data Exchange (ETDEWEB)

Maskaly, Karlene Rosera [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2005-06-01

Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with

Performance of Reverse-Link Synchronous DS-CDMA System on a Frequency-Selective Multipath Fading Channel with Imperfect Power Control

Directory of Open Access Journals (Sweden)

Duk Kyung Kim

2002-08-01

Full Text Available We analyze the performance for reverse-link synchronous DS-CDMA system in a frequency-selective Rayleigh fading channel with an imperfect power control scheme. The performance degradation due to power control error (PCE, which is approximated by a log-normally distributed random variable, is estimated as a function of the standard deviation of the PCE. In addition, we investigate the impacts of the multipath intensity profile (MIP shape and the number of resolvable paths on the performance. Finally, the coded bit error performance is evaluated in order to estimate the system capacity. Comparing with the conventional CDMA system, we show an achievable gain of from 59% to 23% for reverse-link synchronous transmission technique (RLSTT in the presence of imperfect power control over asynchronous transmission for BER=10−6. As well, the effect of tradeoff between orthogonality and diversity can be seen according to the number of multipaths, and the tendency is kept even in the presence of PCE. We conclude that the capacity can be further improved via the RLSTT, because the DS-CDMA system is very sensitive to power control imperfections.

Puzzling the Jesus of the Parables: A response to Ruben Zimmermann

Directory of Open Access Journals (Sweden)

Llewellyn Howes

2017-07-01

Full Text Available This article responds to Ruben Zimmermann’s latest book, Puzzling the Parables of Jesus (2015. In particular, one aspect of his proposed method is challenged, namely, his conscious attempt to do away with considerations of the pre-Easter context when interpreting the parables. The article finishes by proposing a variant methodology of parable interpretation, featuring the parable of the Good Samaritan as a working example.

HIV in Japan: Epidemiologic puzzles and ethnographic explanations

Directory of Open Access Journals (Sweden)

Anthony S. DiStefano

2016-12-01

Full Text Available Japan is widely perceived to have a low level of HIV occurrence; however, its HIV epidemics also have been the subject of considerable misunderstanding globally. I used a ground truthing conceptual framework to meet two aims: first, to determine how accurately official surveillance data represented Japan's two largest epidemics (urban Kansai and Tokyo as understood and experienced on the ground; and second, to identify explanations for why the HIV epidemics were unfolding as officially reported. I used primarily ethnographic methods while drawing upon epidemiology, and compared government surveillance data to observations at community and institutional sites (459 pages of field notes; 175 persons observed, qualitative interviews with stakeholders in local HIV epidemics (n = 32, and document research (n = 116. This revealed seven epidemiologic puzzles involving officially reported trends and conspicuously missing information. Ethnographically grounded explanations are presented for each. These included factors driving the epidemics, which ranged from waning government and public attention to HIV, to gaps in sex education and disruptive leadership changes in public institutions approximately every two years. Factors constraining the epidemics also contributed to explanations. These ranged from subsidized medical treatment for most people living with HIV, to strong partnerships between government and a well-developed, non-governmental sector of HIV interventionists, and protective norms and built environments in the sex industry. Local and regional HIV epidemics were experienced and understood as worse than government reports indicated, and ground-level data often contradicted official knowledge. Results thus call into question epidemiologic trends, including recent stabilization of the national epidemic, and suggest the need for revisions to the surveillance system and strategies that address factors driving and constraining the epidemics. Based

The orthopositronium lifetime puzzle and its final solution

International Nuclear Information System (INIS)

Liu Feng; Wu Jianda; Zhan Liang; Ye Bangjiao

2004-01-01

The ortho-positronium (o-Ps), which consists of an electron and positron, is a pure lepton bound system. The o-Ps lifetime can be calculated accurately by quantum electrodynamics, but there is a long-standing discrepancy between the theoretical calculations and the experimental results. Theoretical and experimental physicists have worked hard for a long time to solve the problem, and recently finally solved this lifetime puzzle. The authors briefly outline the discrepancy between the theoretical calculations of the o-Ps annihilation decay rate and some of the experimental measurements, as well as recent developments of experimental techniques, and its final solution. In particular, the final results of the Tokyo and michigan groups are discussed

Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

Science.gov (United States)

Taylor, Wendy; Stacey, Kaye

2014-01-01

This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

Independent attacks in imperfect settings: A case for a two-way quantum key distribution scheme

International Nuclear Information System (INIS)

Shaari, J.S.; Bahari, Iskandar

2010-01-01

We review the study on a two-way quantum key distribution protocol given imperfect settings through a simple analysis of a toy model and show that it can outperform a BB84 setup. We provide the sufficient condition for this as a ratio of optimal intensities for the protocols.

Matter-antimatter puzzle: LHCb improves resolution

CERN Multimedia

Antonella Del Rosso

2012-01-01

In 2010, Fermilab’s DØ experiment reported a one percent difference in the properties of matter and antimatter in decays of B mesons (that is, particles containing beauty quarks) to muons. Saturday, at the ICHEP Conference in Melbourne, the LHCb experiment at CERN presents new results, which do not confirm this anomaly and are consistent with the Standard Model predictions. The same experiment has also presented the first evidence of asymmetry arising in other decays of the same family of mesons. The image becomes clearer but the puzzle has not yet been solved.   Inside the LHCb detector. The matter-antimatter imbalance in the Universe is a very hot topic in physics. The conundrum arises from the fact that, although objects made of antimatter are not observed in the Universe, theory predicts that matter and antimatter be created equally in particle interactions and in the Big Bang. Only small deviations from this very symmetric behaviour are incorporated in the theory. E...

Heavy quarkonium: progress, puzzles, and opportunities

CERN Document Server

Brambilla, N; Heltsley, B K; Vogt, R; Bodwin, G T; Eichten, E; Frawley, A D; Meyer, A B; Mitchell, R E; Papadimitriou, V; Petreczky, P; Petrov, A A; Robbe, P; Vairo, A; Andronic, A; Arnaldi, R; Artoisenet, P; Bali, G; Bertolin, A; Bettoni, D; Brodzicka, J; Bruno, G E; Caldwell, A; Catmore, J; Chang, C H; Chao, K T; Chudakov, E; Cortese, P; Crochet, P; Drutskoy, A; Ellwanger, U; Faccioli, P; Gabareen Mokhtar, A; Garcia i Tormo, X; Hanhart, C; Harris, F A; Kaplan, D M; Klein, S R; Kowalski, H; Lansberg, J P; Levichev, E; Lombardo, V; Lourenco, C; Maltoni, F; Mocsy, A; Mussa, R; Navarra, F S; Negrini, M; Nielsen, M; Olsen, S L; Pakhlov, P; Pakhlova, G; Peters, K; Polosa, A D; Qian, W; Qiu, J W; Rong, G; Sanchis-Lozano, M A; Scomparin, E; Senger, P; Simon, F; Stracka, S; Sumino, Y; Voloshin, M; Weiss, C; Wohri, H K; Yuan, C Z

2011-01-01

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA, JLab, and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing ...

Long-distance quantum key distribution with imperfect devices

International Nuclear Information System (INIS)

Lo Piparo, Nicoló; Razavi, Mohsen

2014-01-01

Quantum key distribution over probabilistic quantum repeaters is addressed. We compare, under practical assumptions, two such schemes in terms of their secure key generation rate per memory, R QKD . The two schemes under investigation are the one proposed by Duan et al. in [Nat. 414, 413 (2001)] and that of Sangouard et al. proposed in [Phys. Rev. A 76, 050301 (2007)]. We consider various sources of imperfections in the latter protocol, such as a nonzero double-photon probability for the source, dark count per pulse, channel loss and inefficiencies in photodetectors and memories, to find the rate for different nesting levels. We determine the maximum value of the double-photon probability beyond which it is not possible to share a secret key anymore. We find the crossover distance for up to three nesting levels. We finally compare the two protocols

Robust Centered Element Concentric Circular Antenna Array with Low Side Lobe Using Variable Loading and Tapering Windows in the Presence of Array Imperfections

Directory of Open Access Journals (Sweden)

M. F. Reza

2017-01-01

Full Text Available This paper presents centered element concentric circular antenna array (CECCAA using variable diagonal loading (VDL technique and different filtering windows. The different filtering windows are modified to apply in the CECCAA system. The modified novel technique not only is able to reduce the side lobe level (SLL but also has the ability to detect and highly attenuate the directional interferences. However, the performance of CECCAA system is degraded in the presence of array imperfections. This performance degradation problem due to array imperfections can be improved by using robust techniques. The proposed technique is also robust against array imperfections and improves the performance. Moreover, the performance of the proposed structure is better than a concentric circular antenna array (CCAA. Several examples are presented to analyze the performance of proposed beamformer by using different tapering windows.

Nonlinear dynamic response of an electrically actuated imperfect microbeam resonator

KAUST Repository

Ruzziconi, Laura

2013-08-04

We present a study of the dynamic behavior of a MEMS device constituted of an imperfect clamped-clamped microbeam subjected to electrostatic and electrodynamic actuation. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. Extensive experimental investigation is conducted, where the main imperfections coming from microfabrication are detected and the nonlinear dynamics are explored at increasing values of electrodynamic excitation, in a neighborhood of the first symmetric resonance. The nonlinear behavior is highlighted, which includes ranges of multistability, where the non-resonant and the resonant branch coexist, and intervals where superharmonic resonances are clearly visible. Numerical simulations are performed. Initially, two single mode reduced-order models are considered. One is generated via the Galerkin technique, and the other one via the combined use of the Ritz method and the Padé approximation. Both of them are able to provide a satisfactory agreement with the experimental data. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Their computational efficiency is discussed in detail, since this is an essential aspect for systematic local and global simulations. Finally, the theoretical analysis is further improved and a two-degree-of-freedom reduced-order model is developed, which is capable also to capture the measured second symmetric superharmonic resonance. Despite the apparent simplicity, it is shown that all the proposed reduced-order models are able to describe the experimental complex nonlinear dynamics of the device accurately and properly, which validates the proposed theoretical approach. Copyright © 2013 by ASME.

Control-limit preventive maintenance policies for components subject to imperfect preventive maintenance and variable operational conditions

International Nuclear Information System (INIS)

You Mingyi; Li Hongguang; Meng Guang

2011-01-01

This paper develops two component-level control-limit preventive maintenance (PM) policies for systems subject to the joint effect of partial recovery PM acts (imperfect PM acts) and variable operational conditions, and investigates the properties of the proposed policies. The extended proportional hazards model (EPHM) is used to model the system failure likelihood influenced by both factors. Several numerical experiments are conducted for policy property analysis, using real lifetime and operational condition data and typical characterization of imperfect PM acts and maintenance durations. The experimental results demonstrate the necessity of considering both factors when they do exist, characterize the joint effect of the two factors on the performance of an optimized PM policy, and explore the influence of the loading sequence of time-varying operational conditions on the performance of an optimized PM policy. The proposed policies extend the applicability of PM optimization techniques.

The Quark Puzzle: A Novel Approach to Visualizing the Color Symmetries of Quarks

Science.gov (United States)

Gettrust, Eric

2010-01-01

This paper describes a simple hands-on and visual-method designed to introduce physics students of many age groups to the topic of quarks and their role in forming composite particles (baryons and mesons). A set of puzzle pieces representing individual quarks that fit together in ways consistent with known restrictions of flavor, color, and charge…

Research on the Mechanism of Cross Organizational Knowledge Sharing in BIM Competitive Environment

Directory of Open Access Journals (Sweden)

Zhong Wei

2017-01-01

Full Text Available Co-opetition under the environment of BIM implementation process because the level is not high resulting in the project BIM application value of incomplete knowledge sharing among organizations, thus establishing good knowledge can effectively solve this problem and achieve the overall benefit and benefit sharing mechanism in the project organization. This paper defines five competing modes according to the competing degree of organization between different BIM applications, including imperfect competition, competition, competition and cooperation, full cooperation and cooperation, and put forward the conceptual model and related assumptions. Analysis of the effect of path and effect of project determined in BIM application mode, the concurrence of knowledge sharing, efficiency and overall efficiency of the project within the organization through the survey and empirical results, and according to the proposed contract, the distribution of benefits and work three kinds of knowledge sharing mechanism implementation path.

DC microgrids providing frequency regulation in electrical power system - imperfect communication issues

DEFF Research Database (Denmark)

Bašić, Hrvoje; Dragicevic, Tomislav; Pandžić, Hrvoje

2017-01-01

This paper presents a model of multiple DC microgrids with battery energy storage systems and demand response capability, taking part in primary frequency regulation of electrical power system. Although DC microgrids can contribute to stability and efficiency of frequency regulation, these complex...... systems may cause serious stability issues due to the imperfect communication. This work presents possible scenarios of unstable primary frequency regulation in a simplified model of electrical power system with DC microgrids, which are controlled through communication network....

The Role of Inhibitory Control in Children's Cooperative Behaviors during a Structured Puzzle Task

Science.gov (United States)

Giannotta, Fabrizia; Burk, William J.; Ciairano, Silvia

2011-01-01

This study examined the role of inhibitory control (measured by Stroop interference) in children's cooperative behaviors during a structured puzzle task. The sample consisted of 250 8-, 10-, and 12-year-olds (117 girls and 133 boys) attending classrooms in three primary schools in Northern Italy. Children individually completed an elaborated…

The Puzzle of Democratic Monopolies: Single Party Dominance and Decline in India

OpenAIRE

Dasgupta, Aditya

2016-01-01

How to explain political monopolies in democratic institutional settings? Dominant parties in countries with robust formal democratic institutions are surprisingly frequent, yet poorly understood. Existing theories explain away the puzzle by characterizing dominant parties as `catch-all' parties that survive on the basis of historically imbued mass voter legitimacy. This dissertation develops a theory of how dominant parties in fact routinely win free and fair elections despite counter-majori...

The Equity Premium Puzzle: Analysis in Brazil after the Real Plan

Directory of Open Access Journals (Sweden)

Fábio Augusto Reis Gomes

2013-04-01

Full Text Available Our paper investigates whether there is evidence of an Equity Premium Puzzle (EPP in Brazil, applying two different methodologies. The EPP was identified by Mehra and Prescott (1985 since the Consumption Capital Asset Pricing Model (CCAPM, when calibrated with reasonable preference parameters, could not explain high historical average risk premiums in the United States. In our first approach, we consider Mehra’s (2003 model and calibrate the coefficient of risk aversion, using 1995:2-2012:1 quarterly data. The Ibovespa index was used as a measure of the market return, whereas the risk-free rate was proxied by the Selic interbank rate and by the savings account rate. In our second approach, we propose a new method to test the puzzle. We jointly estimate, via generalized method of moments, the parameters of interest using a moment condition that has not been previously explored, as far as we are aware of. The two approaches produced a high risk aversion coefficient, however the second approach indicated that we cannot reject the hypothesis of the risk aversion coefficient being statistically equal to zero. A possible explanation for this result might be that in Brazil the equity premium is not statistically different from zero. Therefore there is no evidence of EPP in Brazil for the studied period.

Wireless Powered Relaying Networks Under Imperfect Channel State Information: System Performance and Optimal Policy for Instantaneous Rate

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D. T. Do

2017-09-01

Full Text Available In this investigation, we consider wireless powered relaying systems, where energy is scavenged by a relay via radio frequency (RF signals. We explore hybrid time switching-based and power splitting-based relaying protocol (HTPSR and compare performance of Amplify-and-Forward (AF with Decode-and-Forward (DF scheme under imperfect channel state information (CSI. Most importantly, the instantaneous rate, achievable bit error rate (BER are determined in the closed-form expressions under the impact of imperfect CSI. Through numerical analysis, we evaluate system insights via different parameters such as power splitting (PS and time switching (TS ratio of the considered HTPSR which affect outage performance and BER. It is noted that DF relaying networks outperform AF relaying networks. Besides that, the numerical results are given to prove the optimization problems of PS and TS ratio to obtain optimal instantaneous rate.

Ambiguity aversion and household portfolio choice puzzles: Empirical evidence*

Science.gov (United States)

Dimmock, Stephen G.; Kouwenberg, Roy; Mitchell, Olivia S.; Peijnenburg, Kim

2017-01-01

We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks. PMID:28458446

Ambiguity aversion and household portfolio choice puzzles: Empirical evidence.

Science.gov (United States)

Dimmock, Stephen G; Kouwenberg, Roy; Mitchell, Olivia S; Peijnenburg, Kim

2016-03-01

We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks.