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Sample records for chapman-ferraro problem

  1. Problems

    Directory of Open Access Journals (Sweden)

    Yekini Shehu

    2010-01-01

    real Banach space which is also uniformly smooth using the properties of generalized f-projection operator. Using this result, we discuss strong convergence theorem concerning general H-monotone mappings and system of generalized mixed equilibrium problems in Banach spaces. Our results extend many known recent results in the literature.

  2. Problem Solving

    Science.gov (United States)

    Kinsella, John J.

    1970-01-01

    Discussed are the nature of a mathematical problem, problem solving in the traditional and modern mathematics programs, problem solving and psychology, research related to problem solving, and teaching problem solving in algebra and geometry. (CT)

  3. Balance Problems

    Science.gov (United States)

    ... you are having balance problems, see your doctor. Balance disorders can be signs of other health problems, such ... cases, treating the illness that is causing the disorder will help with the balance problem. Exercises, a change in diet, and some ...

  4. Hemiequilibrium problems

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2004-01-01

    Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.

  5. Walking Problems

    Science.gov (United States)

    ... your legs or feet Movement disorders such as Parkinson's disease Diseases such as arthritis or multiple sclerosis Vision or balance problems Treatment of walking problems depends on the cause. Physical therapy, surgery, or mobility aids may help.

  6. Prostate Problems

    Science.gov (United States)

    ... know the exact cause of your prostate problem. Prostatitis The cause of prostatitis depends on whether you ... prostate problem in men older than age 50. Prostatitis If you have a UTI, you may be ...

  7. LAMB PROBLEM

    Directory of Open Access Journals (Sweden)

    Terent'eva Elena Olegovna

    2013-09-01

    Full Text Available Inner and outer Lamb problems are of extreme importance for various applications in geophysics, as these problems are often used for simulation of wave fields accompanying earthquakes. Solutions of the outer Lamb problem of concentrated force impact applied to the free surface of an elastic half-plane are analyzed in this article. Two solutions are compared: the analytical solution obtained in 1984 and the solution obtained in a modern FEM complex Abaqus.

  8. LAMB PROBLEM

    OpenAIRE

    Terent'eva Elena Olegovna

    2013-01-01

    Inner and outer Lamb problems are of extreme importance for various applications in geophysics, as these problems are often used for simulation of wave fields accompanying earthquakes. Solutions of the outer Lamb problem of concentrated force impact applied to the free surface of an elastic half-plane are analyzed in this article. Two solutions are compared: the analytical solution obtained in 1984 and the solution obtained in a modern FEM complex Abaqus.

  9. Knee Problems

    Science.gov (United States)

    ... BMI Calculator myhealthfinder Immunization Schedules Nutrient Shortfall Questionnaire Knee ProblemsPain, swelling, stiffness and "water" on the knee are common symptoms. Follow this chart for more ...

  10. Popular Problems

    Science.gov (United States)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…

  11. Tongue problems

    Science.gov (United States)

    ... Tongue pain may also occur with: Diabetic neuropathy Leukoplakia Mouth ulcers Oral cancer After menopause, some women ... problem. Medicine may be prescribed for mouth ulcers, leukoplakia, oral cancer, and other mouth sores. Anti-inflammatory ...

  12. Erection problems

    Science.gov (United States)

    ... monitoring to test how strong your erection is Psychological tests to check for depression and other emotional problems ... the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should ...

  13. Kidney Problems

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & Information The kidneys are two ... the production of red blood cells. What are Kidney Diseases? For about one-third of older people, ...

  14. Popular Problems

    DEFF Research Database (Denmark)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2016-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....

  15. Sleep Problems

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... PDF 474KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  16. Eyelid Problems

    Science.gov (United States)

    ... Ear Nose & Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth ... an irregular shape (astigmatism), it will threaten normal vision development and must be corrected as early as ...

  17. Breathing Problems

    Science.gov (United States)

    ... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.

  18. Sociale problemer

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter;

    Sociale problemer kan betragtes som selve udgangspunktet for socialt arbejde, hvor ambitionen er at råde bod på problemerne og sikre, at udsatte borgere får en bedre tilværelse. Det betyder også, at diskussionen af sociale problemer er afgørende for den sociale grundfaglighed. I denne bog sætter en...

  19. Knapsack problems

    CERN Document Server

    Kellerer, Hans; Pisinger, David

    2004-01-01

    Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num­ ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...

  20. Calculus problems

    CERN Document Server

    Baronti, Marco; van der Putten, Robertus; Venturi, Irene

    2016-01-01

    This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...

  1. Optimization Problems

    Directory of Open Access Journals (Sweden)

    Yaping Hu

    2015-01-01

    the nonsmooth convex optimization problem. First, by using Moreau-Yosida regularization, we convert the original objective function to a continuously differentiable function; then we use approximate function and gradient values of the Moreau-Yosida regularization to substitute the corresponding exact values in the algorithm. The global convergence is proved under suitable assumptions. Numerical experiments are presented to show the effectiveness of this algorithm.

  2. Complementarity Problems

    Directory of Open Access Journals (Sweden)

    Xin-He Miao

    2012-01-01

    Full Text Available This paper investigates the Lipschitz continuity of the solution mapping of symmetric cone (linear or nonlinear complementarity problems (SCLCP or SCCP, resp. over Euclidean Jordan algebras. We show that if the transformation has uniform Cartesian P-property, then the solution mapping of the SCCP is Lipschitz continuous. Moreover, we establish that the monotonicity of mapping and the Lipschitz continuity of solutions of the SCLCP imply ultra P-property, which is a concept recently developed for linear transformations on Euclidean Jordan algebra. For a Lyapunov transformation, we prove that the strong monotonicity property, the ultra P-property, the Cartesian P-property, and the Lipschitz continuity of the solutions are all equivalent to each other.

  3. Class and Home Problems: Optimization Problems

    Science.gov (United States)

    Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard

    2011-01-01

    Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…

  4. The Chicken Problem.

    Science.gov (United States)

    Reeves, Charles A.

    2000-01-01

    Uses the chicken problem for sixth grade students to scratch the surface of systems of equations using intuitive approaches. Provides students responses to the problem and suggests similar problems for extensions. (ASK)

  5. Constipation and Defecation Problems

    Science.gov (United States)

    ... Home / Digestive Health Topic / Constipation and Defecation Problems Constipation and Defecation Problems Basics Resources Overview Constipation is one of the most frequent gastrointestinal complaints ...

  6. Quadratic eigenvalue problems.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Day, David Minot

    2007-04-01

    In this report we will describe some nonlinear eigenvalue problems that arise in the areas of solid mechanics, acoustics, and coupled structural acoustics. We will focus mostly on quadratic eigenvalue problems, which are a special case of nonlinear eigenvalue problems. Algorithms for solving the quadratic eigenvalue problem will be presented, along with some example calculations.

  7. PROBLEMS OF MIGRANT LABOR.

    Science.gov (United States)

    WALLS, FOREST

    PRESENT MIGRANT LABOR PROBLEMS AND SOLUTIONS WHICH HAVE BEEN PROPOSED ARE PRESENTED. THE FIRST PROBLEM AREA IS PROVIDING EDUCATION FOR MIGRANT CHILDREN. THIS IS HINDERED BY THE PROBLEM OF SECURING COMPLIANCE WITH MINIMUM EDUCATION LAWS AND BY LAWS PROHIBITING EMPLOYMENT OF CHILDREN DURING SCHOOL HOURS. A SECOND PROBLEM AREA IS THAT OF CHILD LABOR.…

  8. Problem solving III: factors influencing classroom problem

    Directory of Open Access Journals (Sweden)

    Sayonara Salvador Cabral da Costa

    1997-05-01

    Full Text Available This paper presents a review of the literature in the area of problem solving, particularly in physics, focusing only on factors that influence classroom problem solving. Fifty-seven papers have been analyzed in terms of theoretical basis, investigated factors/methodology and findings/relevant factors, which were organized in a table that served as support for a synthesis made by the authors. It is the third of a four-paper series reviewing different aspects of the problem solving subject.

  9. Differential equations problem solver

    CERN Document Server

    Arterburn, David R

    2012-01-01

    REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and

  10. Creativity for Problem Solvers

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    2009-01-01

    This paper presents some modern and interdisciplinary concepts about creativity and creative processes specially related to problem solving. Central publications related to the theme are briefly reviewed. Creative tools and approaches suitable to support problem solving are also presented. Finall...

  11. Types of Learning Problems

    Science.gov (United States)

    ... Ear Nose & Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth ... important distinction is that this is not a vision problem ; rather, the brain is reversing, inverting or ...

  12. Challenging problems in algebra

    CERN Document Server

    Posamentier, Alfred S

    1996-01-01

    Over 300 unusual problems, ranging from easy to difficult, involving equations and inequalities, Diophantine equations, number theory, quadratic equations, logarithms, more. Detailed solutions, as well as brief answers, for all problems are provided.

  13. Mathematics as Problem Solving.

    Science.gov (United States)

    Soifer, Alexander

    This book contains about 200 problems. It is suggested that it be used by students, teachers or anyone interested in exploring mathematics. In addition to a general discussion on problem solving, there are problems concerned with number theory, algebra, geometry, and combinatorics. (PK)

  14. Vehicle Routing Problem Models

    Directory of Open Access Journals (Sweden)

    Tonči Carić

    2004-01-01

    Full Text Available The Vehicle Routing Problem cannot always be solved exactly,so that in actual application this problem is solved heuristically.The work describes the concept of several concrete VRPmodels with simplified initial conditions (all vehicles are ofequal capacity and start from a single warehouse, suitable tosolve problems in cases with up to 50 users.

  15. Optimal obstacle control problem

    Institute of Scientific and Technical Information of China (English)

    ZHU Li; LI Xiu-hua; GUO Xing-ming

    2008-01-01

    In the paper we discuss some properties of the state operators of the optimal obstacle control problem for elliptic variational inequality. Existence, uniqueness and regularity of the optimal control problem are established. In addition, the approximation of the optimal obstacle problem is also studied.

  16. Classifying IS Project Problems

    DEFF Research Database (Denmark)

    Munk-Madsen, Andreas

    2006-01-01

    The literature contains many lists of IS project problems, often in the form of risk factors. The problems sometimes appear unordered and overlapping, which reduces their usefulness to practitioners as well as theoreticians. This paper proposes a list of criteria for formulating project problems...

  17. Sonet Network Design Problems

    Directory of Open Access Journals (Sweden)

    Marie Pelleau

    2009-10-01

    Full Text Available This paper presents a new method and a constraint-based objective function to solve two problems related to the design of optical telecommunication networks, namely the Synchronous Optical Network Ring Assignment Problem (SRAP and the Intra-ring Synchronous Optical Network Design Problem (IDP. These network topology problems can be represented as a graph partitioning with capacity constraints as shown in previous works. We present here a new objective function and a new local search algorithm to solve these problems. Experiments conducted in Comet allow us to compare our method to previous ones and show that we obtain better results.

  18. Sonet Network Design Problems

    CERN Document Server

    Pelleau, Marie; Truchet, Charlotte

    2009-01-01

    This paper presents a new method and a constraint-based objective function to solve two problems related to the design of optical telecommunication networks, namely the Synchronous Optical Network Ring Assignment Problem (SRAP) and the Intra-ring Synchronous Optical Network Design Problem (IDP). These network topology problems can be represented as a graph partitioning with capacity constraints as shown in previous works. We present here a new objective function and a new local search algorithm to solve these problems. Experiments conducted in Comet allow us to compare our method to previous ones and show that we obtain better results.

  19. Path Problems in Networks

    CERN Document Server

    Baras, John

    2010-01-01

    The algebraic path problem is a generalization of the shortest path problem in graphs. Various instances of this abstract problem have appeared in the literature, and similar solutions have been independently discovered and rediscovered. The repeated appearance of a problem is evidence of its relevance. This book aims to help current and future researchers add this powerful tool to their arsenal, so that they can easily identify and use it in their own work. Path problems in networks can be conceptually divided into two parts: A distillation of the extensive theory behind the algebraic path pr

  20. The Accelerated Kepler Problem

    CERN Document Server

    Namouni, Fathi

    2007-01-01

    The accelerated Kepler problem is obtained by adding a constant acceleration to the classical two-body Kepler problem. This setting models the dynamics of a jet-sustaining accretion disk and its content of forming planets as the disk loses linear momentum through the asymmetric jet-counterjet system it powers. The dynamics of the accelerated Kepler problem is analyzed using physical as well as parabolic coordinates. The latter naturally separate the problem's Hamiltonian into two unidimensional Hamiltonians. In particular, we identify the origin of the secular resonance in the accelerated Kepler problem and determine analytically the radius of stability boundary of initially circular orbits that are of particular interest to the problem of radial migration in binary systems as well as to the truncation of accretion disks through stellar jet acceleration.

  1. Matrix interdiction problem

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

    2010-01-01

    In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.

  2. Group Problem Solving

    CERN Document Server

    Laughlin, Patrick R

    2011-01-01

    Experimental research by social and cognitive psychologists has established that cooperative groups solve a wide range of problems better than individuals. Cooperative problem solving groups of scientific researchers, auditors, financial analysts, air crash investigators, and forensic art experts are increasingly important in our complex and interdependent society. This comprehensive textbook--the first of its kind in decades--presents important theories and experimental research about group problem solving. The book focuses on tasks that have demonstrably correct solutions within mathematical

  3. Problems in real analysis

    OpenAIRE

    Rǎdulescu, Teodora-Liliana T.; Andreescu, Titu; Rǎdulescu, Vicenţiu

    2015-01-01

    This book ontains a collection of challenging problems in elementary mathematical analysis, uses competition-inspired problems as a platform for training typical inventive skills, develops basic valuable techniques for solving problems in mathematical analysis on the real axis, assumes only a basic knowledge of the topic but opens the path to competitive research in the field, includes interesting and valuable historical accounts of ideas and methods in analysis, presents a connection between...

  4. Location-routing problems

    Energy Technology Data Exchange (ETDEWEB)

    Laporte, G.

    1987-01-01

    Location-routing problems involve simultaneously locating a number of facilities among candidate sites and establishing delivery routes to a set of users in such a way that the total system cost is minimized. This paper presents a survey of such problems. It includes some applications and examples of location-routing problems, a description of the main heuristics that have been developed for such problems, and reviews of various formulations and algorithms used in solving these problems. A more detailed review is given of exact algorithms for the vehicle routing problem, three-index vehicle flow formulations, and two-index vehicle flow formulations and algorithms for symmetrical and non-symmetrical problems. It is concluded that location-routing problem research is a fast-growing area, with most developments occurring over the past few years; however, research is relatively fragmented, often addresses problems which are too specific and contains several voids which have yet to be filled. A number of promising research areas are identified. 137 refs., 3 figs.

  5. Numerical problems in physics

    CERN Document Server

    Singh, Devraj

    2015-01-01

    Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

  6. Known TCP Implementation Problems

    Science.gov (United States)

    Paxson, Vern (Editor); Allman, Mark; Dawson, Scott; Fenner, William; Griner, Jim; Heavens, Ian; Lahey, K.; Semke, J.; Volz, B.

    1999-01-01

    This memo catalogs a number of known TCP implementation problems. The goal in doing so is to improve conditions in the existing Internet by enhancing the quality of current TCP/IP implementations. It is hoped that both performance and correctness issues can be resolved by making implementors aware of the problems and their solutions. In the long term, it is hoped that this will provide a reduction in unnecessary traffic on the network, the rate of connection failures due to protocol errors, and load on network servers due to time spent processing both unsuccessful connections and retransmitted data. This will help to ensure the stability of the global Internet. Each problem is defined as follows: Name of Problem The name associated with the problem. In this memo, the name is given as a subsection heading. Classification one or more problem categories for which the problem is classified: "congestion control", "performance", "reliability", "resource management". Description A definition of the problem, succinct but including necessary background material. Significance A brief summary of the sorts of environments for which the problem is significant.

  7. Problems in quantum mechanics

    CERN Document Server

    Goldman, Iosif Ilich; Geilikman, B T

    2006-01-01

    This challenging book contains a comprehensive collection of problems in nonrelativistic quantum mechanics of varying degrees of difficulty. It features answers and completely worked-out solutions to each problem. Geared toward advanced undergraduates and graduate students, it provides an ideal adjunct to any textbook in quantum mechanics.

  8. Simon on problem solving

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul

    2006-01-01

    as a general approach to problem solving. We apply these Simonian ideas to organisational issues, specifically new organisational forms. Specifically, Simonian ideas allow us to develop a morphology of new organisational forms and to point to some design problems that characterise these forms....

  9. Problems in baryon spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Capstick, S. [Florida State Univ., Tallahassee, FL (United States)

    1994-04-01

    Current issues and problems in the physics of ground- and excited-state baryons are considered, and are classified into those which should be resolved by CEBAF in its present form, and those which may require CEBAF to undergo an energy upgrade to 8 GeV or more. Recent theoretical developments designed to address these problems are outlined.

  10. Problem Solving Techniques Seminar.

    Science.gov (United States)

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. Six problem-solving techniques are developed in the booklet to assist individuals and groups in making better decisions: problem identification, data gathering, data analysis, solution analysis,…

  11. A Stochastic Employment Problem

    Science.gov (United States)

    Wu, Teng

    2013-01-01

    The Stochastic Employment Problem(SEP) is a variation of the Stochastic Assignment Problem which analyzes the scenario that one assigns balls into boxes. Balls arrive sequentially with each one having a binary vector X = (X[subscript 1], X[subscript 2],...,X[subscript n]) attached, with the interpretation being that if X[subscript i] = 1 the ball…

  12. The Problem Revisited

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2015-01-01

    Problem-based learning (PBL) is becoming increasingly popular in design educations, but how is it taught and practiced? This paper presents a case study of a three-day workshop that has the purpose of introducing PBL to design students. A theoretical background on PBL and problems in design is es...

  13. Wicked Problems: Inescapable Wickedity

    Science.gov (United States)

    Jordan, Michelle E.; Kleinsasser, Robert C.; Roe, Mary F.

    2014-01-01

    The article explores the concept of wicked problems and proposes a reinvigorated application of this concept for wider educational use. This recommendation stems from the contributions of a number of scholars who frame some of the most contentious and recalcitrant educational issues as wicked problems. The present authors build upon these previous…

  14. CHRONIC PROBLEM FAMILIES.

    Science.gov (United States)

    STONE, EDWARD

    THE REPORT POINTS OUT THAT, IN GENERAL, CHRONIC PROBLEM PARENTS GREW UP IN ENVIRONMENTS OF EMOTIONAL IMPOVERISHMENT, INCONSISTENCY, CONFUSION, AND DISORDER, OFTEN WITH DEPRIVATION OF FOOD, CLOTHING, AND SHELTER. THESE PARENTS CATEGORIZE PEOPLE AS THOSE WHO GIVE AND THOSE WHO TAKE. THEY BLAME THEIR PROBLEMS ON EXTERNAL CIRCUMSTANCES NOT UNDER THEIR…

  15. Dynamical inverse problems

    CERN Document Server

    Gladwell, Graham ML

    2011-01-01

    The papers in this volume present an overview of the general aspects and practical applications of dynamic inverse methods, through the interaction of several topics, ranging from classical and advanced inverse problems in vibration, isospectral systems, dynamic methods for structural identification, active vibration control and damage detection, imaging shear stiffness in biological tissues, wave propagation, to computational and experimental aspects relevant for engineering problems.

  16. PROBLEMS OF TURKISH LEXICOGRAPHY.

    Science.gov (United States)

    TIETZE, ANDREAS

    THE LEXICOGRAPHICAL PROBLEMS IN THE TURKISH LANGUAGE WERE DISCUSSED. HISTORICAL REVIEW OF THE LANGUAGE WAS PRESENTED WITH PROBLEMS OF LEXICOGRAPHY THAT EXISTED IN THE PAST COMPARED WITH THOSE OF THE PRESENT. DISCUSSION TOPICS OF THE REPORT INCLUDED (1) NAME OF THE LANGUAGE, (2) DELIMITATION COMPARED WITH RELATED LANGUAGES, (3) DELIMINATION…

  17. Reconfigurable layout problem

    NARCIS (Netherlands)

    Meng, G.; Heragu, S.S.; Zijm, H.

    2004-01-01

    This paper addresses the reconfigurable layout problem, which differs from traditional, robust and dynamic layout problems mainly in two aspects: first, it assumes that production data are available only for the current and upcoming production period. Second, it considers queuing performance measure

  18. Current Social Problem Novels.

    Science.gov (United States)

    Kenney, Donald J.

    This review of social problem novels for young adults opens with a brief background of the genre, then lists the dominant themes of social problem fiction and nonfiction novels that have been published in the last two years, such as alcoholism, alienation, death, growing up and self-awarness, drugs, and divorce. Other themes mentioned are…

  19. Student-Posed Problems

    Science.gov (United States)

    Harper, Kathleen A.; Etkina, Eugenia

    2002-10-01

    As part of weekly reports,1 structured journals in which students answer three standard questions each week, they respond to the prompt, If I were the instructor, what questions would I ask or problems assign to determine if my students understood the material? An initial analysis of the results shows that some student-generated problems indicate fundamental misunderstandings of basic physical concepts. A further investigation explores the relevance of the problems to the week's material, whether the problems are solvable, and the type of problems (conceptual or calculation-based) written. Also, possible links between various characteristics of the problems and conceptual achievement are being explored. The results of this study spark many more questions for further work. A summary of current findings will be presented, along with its relationship to previous work concerning problem posing.2 1Etkina, E. Weekly Reports;A Two-Way Feedback Tool, Science Education, 84, 594-605 (2000). 2Mestre, J.P., Probing Adults Conceptual Understanding and Transfer of Learning Via Problem Posing, Journal of Applied Developmental Psychology, 23, 9-50 (2002).

  20. Simplifying Complex Problems

    Directory of Open Access Journals (Sweden)

    Dan Ophir

    2011-12-01

    Full Text Available The process of making complex and controversial decisions, that is, dealing with moral or ethical dilemmas, have intrigued people and inspired writers from time immemorial. Dilemmas give both color and depth to characters in good literary works. But beyond literary fiction, dilemmas occupy society in every day issues such as in introducing legislation or solving current political problems. One example of a current political dilemma is how to deal with Iran’s quest for nuclear weapons. If it were possible to assess and quantify each of the alternative solutions for a given problem, the process of decision making would be much easier. If a problem involves only two optional solutions, game theory techniques can be used. However, real life problems are usually multi-unit, multi-optional problems, as in Iran

  1. The interval ordering problem

    CERN Document Server

    Dürr, Christoph; Spieksma, Frits C R; Nobibon, Fabrice Talla; Woeginger, Gerhard J

    2011-01-01

    For a given set of intervals on the real line, we consider the problem of ordering the intervals with the goal of minimizing an objective function that depends on the exposed interval pieces (that is, the pieces that are not covered by earlier intervals in the ordering). This problem is motivated by an application in molecular biology that concerns the determination of the structure of the backbone of a protein. We present polynomial-time algorithms for several natural special cases of the problem that cover the situation where the interval boundaries are agreeably ordered and the situation where the interval set is laminar. Also the bottleneck variant of the problem is shown to be solvable in polynomial time. Finally we prove that the general problem is NP-hard, and that the existence of a constant-factor-approximation algorithm is unlikely.

  2. Two-Manifold Problems

    CERN Document Server

    Boots, Byron

    2011-01-01

    Recently, there has been much interest in spectral approaches to learning manifolds---so-called kernel eigenmap methods. These methods have had some successes, but their applicability is limited because they are not robust to noise. To address this limitation, we look at two-manifold problems, in which we simultaneously reconstruct two related manifolds, each representing a different view of the same data. By solving these interconnected learning problems together and allowing information to flow between them, two-manifold algorithms are able to succeed where a non-integrated approach would fail: each view allows us to suppress noise in the other, reducing bias in the same way that an instrumental variable allows us to remove bias in a {linear} dimensionality reduction problem. We propose a class of algorithms for two-manifold problems, based on spectral decomposition of cross-covariance operators in Hilbert space. Finally, we discuss situations where two-manifold problems are useful, and demonstrate that sol...

  3. The Guderley problem revisited

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Scott D [Los Alamos National Laboratory; Kamm, James R [Los Alamos National Laboratory; Bolstad, John H [NON LANL

    2009-01-01

    The self-similar converging-diverging shock wave problem introduced by Guderley in 1942 has been the source of numerous investigations since its publication. In this paper, we review the simplifications and group invariance properties that lead to a self-similar formulation of this problem from the compressible flow equations for a polytropic gas. The complete solution to the self-similar problem reduces to two coupled nonlinear eigenvalue problems: the eigenvalue of the first is the so-called similarity exponent for the converging flow, and that of the second is a trajectory multiplier for the diverging regime. We provide a clear exposition concerning the reflected shock configuration. Additionally, we introduce a new approximation for the similarity exponent, which we compare with other estimates and numerically computed values. Lastly, we use the Guderley problem as the basis of a quantitative verification analysis of a cell-centered, finite volume, Eulerian compressible flow algorithm.

  4. Structural Identification Problem

    Directory of Open Access Journals (Sweden)

    Suvorov Aleksei

    2016-01-01

    Full Text Available The identification problem of the existing structures though the Quasi-Newton and its modification, Trust region algorithms is discussed. For the structural problems, which could be represented by means of the mathematical modelling of the finite element code discussed method is extremely useful. The nonlinear minimization problem of the L2 norm for the structures with linear elastic behaviour is solved by using of the Optimization Toolbox of Matlab. The direct and inverse procedures for the composition of the desired function to minimize are illustrated for the spatial 3D truss structure as well as for the problem of plane finite elements. The truss identification problem is solved with 2 and 3 unknown parameters in order to compare the computational efforts and for the graphical purposes. The particular commands of the Matlab codes are present in this paper.

  5. Problems in equilibrium theory

    CERN Document Server

    Aliprantis, Charalambos D

    1996-01-01

    In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

  6. The road coloring problem

    CERN Document Server

    Trahtman, A N

    2007-01-01

    The synchronizing word of deterministic automaton is a word in the alphabet of colors (considered as letters) of its edges that maps the automaton to a single state. A coloring of edges of a directed graph is synchronizing if the coloring turns the graph into deterministic finite automaton possessing a synchronizing word. The road coloring problem is a problem of synchronizing coloring of directed finite strongly connected graph with constant outdegree of all its vertices if the greatest common divisor of lengths of all its cycles is one. The problem was posed by Adler, Goodwyn and Weiss over 30 years ago and evoked a noticeable interest among the specialists in theory of graphs, deterministic automata and symbolic dynamics. The problem is described even in "Vikipedia" - the popular Internet Encyclopedia. The positive solution of the road coloring problem is presented.

  7. Problem Solving and Learning

    CERN Document Server

    Singh, Chandralekha

    2016-01-01

    One finding of cognitive research is that people do not automatically acquire usable knowledge by spending lots of time on task. Because students' knowledge hierarchy is more fragmented, "knowledge chunks" are smaller than those of experts. The limited capacity of short term memory makes the cognitive load high during problem solving tasks, leaving few cognitive resources available for metacognition. The abstract nature of the laws of physics and the chain of reasoning required to draw meaningful inferences makes these issues critical. In order to help students, it is crucial to consider the difficulty of a problem from the perspective of students. We are developing and evaluating interactive problem-solving tutorials to help students in the introductory physics courses learn effective problem-solving strategies while solidifying physics concepts. The self-paced tutorials can provide guidance and support for a variety of problem solving techniques, and opportunity for knowledge and skill acquisition.

  8. The Interaction Programming Problem

    Institute of Scientific and Technical Information of China (English)

    LI Rong-sheng; CHENG Ying

    2001-01-01

    Based upon the research to the economic equilibrium problems, we present a kind of new mathematical programming problem-interaction programming problem (abbreviated by IPP). The IPP is composed of two or multiple parametric programming problems which is interrelated with each other. The IPP reflects the equality and mutual benefit relationship between two (or among multiple) economic planners in an economic system. In essence, the IPP is similar to the generalized Nash equilibria (GNE) game which has been given several names in the literature: social equilibria games, pseudo-Nash equilibria games, and equilibrium programming problems. In this paper, we establish the mathematical model and some basic concepts to the IPP. We investigate the structure and the properties of the IPP. We also give a necessary and sufficient conditions for the existence of the equilibrium points to a kind of linear IPP.

  9. Problems of energy supply. Probleme der Energieversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Frank, W.

    1983-01-01

    Political education is to enable judgement of present-day questions. This requires knowledge of the essential facts in the field of energy supply. The brochure on hand is meant to make it easier for the reader to put forward his own arguments. The reader is to see that it is due to the many motives determining energy policy which aggravate an understanding about ways of solving problems of energy supply. This brochure is designed to enhance political education by giving a survey of tasks in energy policy to be solved on an international level and in Austria.

  10. Generalized emissivity inverse problem.

    Science.gov (United States)

    Ming, DengMing; Wen, Tao; Dai, XianXi; Dai, JiXin; Evenson, William E

    2002-04-01

    Inverse problems have recently drawn considerable attention from the physics community due to of potential widespread applications [K. Chadan and P. C. Sabatier, Inverse Problems in Quantum Scattering Theory, 2nd ed. (Springer Verlag, Berlin, 1989)]. An inverse emissivity problem that determines the emissivity g(nu) from measurements of only the total radiated power J(T) has recently been studied [Tao Wen, DengMing Ming, Xianxi Dai, Jixin Dai, and William E. Evenson, Phys. Rev. E 63, 045601(R) (2001)]. In this paper, a new type of generalized emissivity and transmissivity inverse (GETI) problem is proposed. The present problem differs from our previous work on inverse problems by allowing the unknown (emissivity) function g(nu) to be temperature dependent as well as frequency dependent. Based on published experimental information, we have developed an exact solution formula for this GETI problem. A universal function set suggested for numerical calculation is shown to be robust, making this inversion method practical and convenient for realistic calculations.

  11. Cumulative Vehicle Routing Problems

    OpenAIRE

    Kara, &#;mdat; Kara, Bahar Yeti&#;; Yeti&#;, M. Kadri

    2008-01-01

    This paper proposes a new objective function and corresponding formulations for the vehicle routing problem. The new cost function defined as the product of the distance of the arc and the flow on that arc. We call a vehicle routing problem with this new objective function as the Cumulative Vehicle Routing Problem (CumVRP). Integer programming formulations with O(n2) binary variables and O(n2) constraints are developed for both collection and delivery cases. We show that the CumVRP is a gener...

  12. Translating a wicked problem

    DEFF Research Database (Denmark)

    Tietjen, Anne; Jørgensen, Gertrud

    2016-01-01

    In a time of increasing globalisation and urbanisation, shrinking peripheral rural areas have become a truly wicked planning problem in many European countries. Although a problem can be easily perceived and measured by various indicators, the precise definition of the problem is problematic. Based......, place-based and project-oriented process directed at concrete physical outcomes. We frame strategic planning as a translation process where the interaction between human and non-human actors translates a unique, complex and contested situation into an innovated situation. We find that local physical...

  13. Problems Digesting Dairy Products?

    Science.gov (United States)

    ... Consumers Home For Consumers Consumer Updates Problems Digesting Dairy Products? Share Tweet Linkedin Pin it More sharing ... the natural sugar found in milk and other dairy products. People who cannot digest lactose have a ...

  14. The Problem of Heroin

    Science.gov (United States)

    Wilson, James Q.; And Others

    1972-01-01

    Argues that most of the underlying assumptions of presently recommended solutions to the problem of heroin addiction are unreasonable, unwarranted, or at least open to more than one interpretation. (DM)

  15. Enuresis: A Social Problem.

    Science.gov (United States)

    McDonald, James E.

    1978-01-01

    Several theories and treatments of enuresis are described. The authors conclude that enuresis is a social problem (perhaps due to maturational lag, developmental delay or faulty learning) which requires teacher and parental tolerance and understanding. (SE)

  16. Open problems in mathematics

    CERN Document Server

    Nash, Jr, John Forbes

    2016-01-01

    The goal in putting together this unique compilation was to present the current status of the solutions to some of the most essential open problems in pure and applied mathematics. Emphasis is also given to problems in interdisciplinary research for which mathematics plays a key role. This volume comprises highly selected contributions by some of the most eminent mathematicians in the international mathematical community on longstanding problems in very active domains of mathematical research. A joint preface by the two volume editors is followed by a personal farewell to John F. Nash, Jr. written by Michael Th. Rassias. An introduction by Mikhail Gromov highlights some of Nash’s legendary mathematical achievements. The treatment in this book includes open problems in the following fields: algebraic geometry, number theory, analysis, discrete mathematics, PDEs, differential geometry, topology, K-theory, game theory, fluid mechanics, dynamical systems and ergodic theory, cryptography, theoretical computer sc...

  17. Diabetic Eye Problems

    Science.gov (United States)

    ... damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause of blindness ... You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your ...

  18. Creative Problem Solving

    Institute of Scientific and Technical Information of China (English)

    岳科来

    2016-01-01

    There have considerable number of design philosophies and design methods in this world,but today I’d like to intorduce a new design problem solving system which comes from Chinese traditonal religion Dao.

  19. The Congruence Subgroup Problem

    Indian Academy of Sciences (India)

    M S Raghunathan

    2004-11-01

    This is a short survey of the progress on the congruence subgroup problem since the sixties when the first major results on the integral unimodular groups appeared. It is aimed at the non-specialists and avoids technical details.

  20. Problems in optics

    CERN Document Server

    Rousseau, Madeleine; Ter Haar, D

    1973-01-01

    This collection of problems and accompanying solutions provide the reader with a full introduction to physical optics. The subject coverage is fairly traditional, with chapters on interference and diffraction, and there is a general emphasis on spectroscopy.

  1. Menstruation and Menstrual Problems

    Science.gov (United States)

    ... and Menstrual Problems: Condition Information Skip sharing on social media links Share this: Page Content What is menstruation? What is the menstrual cycle? When happens when a pregnancy occurs? What is menstruation? Menstruation (pronounced men-stroo- ...

  2. Translating a wicked problem

    DEFF Research Database (Denmark)

    Tietjen, Anne; Jørgensen, Gertrud

    2016-01-01

    In a time of increasing globalisation and urbanisation, shrinking peripheral rural areas have become a truly wicked planning problem in many European countries. Although a problem can be easily perceived and measured by various indicators, the precise definition of the problem is problematic. Based...... on the case of a Danish planning process which was carried out in collaboration with a charitable trust, this paper discusses an emerging strategic planning approach at the municipal level. We use the concept of wicked problems, strategic planning theory and Actor-Network-Theory to study a collaborative......, place-based and project-oriented process directed at concrete physical outcomes. We frame strategic planning as a translation process where the interaction between human and non-human actors translates a unique, complex and contested situation into an innovated situation. We find that local physical...

  3. [Oral problems in divers].

    Science.gov (United States)

    Scheper, W A; Lobbezoo, F; Eijkman, M A J

    2005-05-01

    Divers can have several oral problems. Firstly, problems caused by pressure changes. These are barodontalgia and odontocrexis. Barodontalgia is toothache by barotrauma. Odontocrexis is restorations coming lose or breaking or tooth fractures by expansion of air beneath restorations. Other problems can occur by cements used to fix casted restorations, by inflammations in the orofacial region, and by not yet fully healed oral wounds. Secondly, there are problems related to the diver's mouthpiece. To keep the mouthpiece in place, the mandible has to be forced in a forward position. Holding this position often and for long periods of time, may develop or aggravate temporomandibular dysfunction. Insufficient fit of the mouthpiece may induce oral mucosal lesions. Therefore, it is recommended to produce individual diver mouthpieces. It is also recommended to produce individual diver mouthpieces for complete dentures wearing divers and for divers with fixed orthodontic appliances.

  4. Escape in Hill's Problem

    CERN Document Server

    Heggie, D C

    2000-01-01

    This didactic paper is motivated by the problem of understanding how stars escape from globular star clusters. One formulation of this problem is known, in dynamical astronomy, as Hill's problem. Originally intended as a model for the motion of the moon around the earth with perturbations by the sun, with simple modifications it also serves as a model for the motion of a star in a star cluster with perturbations by the galaxy. The paper includes introductory sections on the derivation of the equations of motion of Hill's problem, their elementary properties, and extensions to deal with non-point masses and non-circular orbits. We then show how the rate of escape may be calculated numerically and estimated theoretically, and discuss how this simple picture is modified if the stars in a cluster are also undergoing two-body relaxation. Finally we introduce some established ideas for obtaining the distribution of escape times.

  5. Problem/science/society

    Directory of Open Access Journals (Sweden)

    Dr Jane Gregory

    2016-11-01

    Full Text Available Framing ‘science and society’ as a conflict has diverted us from more important problems. Our economic environment urges the commercialisation and social acceptance of new technologies, and science communicators and their publics contribute work to these ends. These activities neglect existing, uncontroversial technologies that, in a collaboration between responsible scientists and their publics, could be deployed to address global problems.

  6. The Byzantine Brides Problem

    CERN Document Server

    Dubois, Swan; Zhu, Nini

    2012-01-01

    We investigate the hardness of establishing as many stable marriages (that is, marriages that last forever) in a population whose memory is placed in some arbitrary state with respect to the considered problem, and where traitors try to jeopardize the whole process by behaving in a harmful manner. On the negative side, we demonstrate that no solution that is completely insensitive to traitors can exist, and we propose a protocol for the problem that is optimal with respect to the traitor containment radius.

  7. The basketball problem

    Science.gov (United States)

    Schröer, H.

    In basketball there is the problem of hitting a basket at a determined distance and a determined height. The quantities that can be changed during the inclined throw are the initial velocity and the angle of throw. At first we neglect the air resistance. Then we treat the same problem in a medium (liquid, gas) with constant density. We obtain two differential equations. Then we view special cases of the retarding force. There is an english and a german edition.

  8. Distributed Storage Allocation Problems

    OpenAIRE

    Leong, Derek; Dimakis, Alexandros G.; Ho, Tracey

    2009-01-01

    We investigate the problem of using several storage nodes to store a data object, subject to an aggregate storage budget or redundancy constraint. It is challenging to find the optimal allocation that maximizes the probability of successful recovery by the data collector because of the large space of possible symmetric and nonsymmetric allocations, and the nonconvexity of the problem. For the special case of probability-l recovery, we show that the optimal allocatio...

  9. Colored Traveling Salesman Problem.

    Science.gov (United States)

    Li, Jun; Zhou, MengChu; Sun, Qirui; Dai, Xianzhong; Yu, Xiaolong

    2015-11-01

    The multiple traveling salesman problem (MTSP) is an important combinatorial optimization problem. It has been widely and successfully applied to the practical cases in which multiple traveling individuals (salesmen) share the common workspace (city set). However, it cannot represent some application problems where multiple traveling individuals not only have their own exclusive tasks but also share a group of tasks with each other. This work proposes a new MTSP called colored traveling salesman problem (CTSP) for handling such cases. Two types of city groups are defined, i.e., each group of exclusive cities of a single color for a salesman to visit and a group of shared cities of multiple colors allowing all salesmen to visit. Evidences show that CTSP is NP-hard and a multidepot MTSP and multiple single traveling salesman problems are its special cases. We present a genetic algorithm (GA) with dual-chromosome coding for CTSP and analyze the corresponding solution space. Then, GA is improved by incorporating greedy, hill-climbing (HC), and simulated annealing (SA) operations to achieve better performance. By experiments, the limitation of the exact solution method is revealed and the performance of the presented GAs is compared. The results suggest that SAGA can achieve the best quality of solutions and HCGA should be the choice making good tradeoff between the solution quality and computing time.

  10. The Steiner tree problem

    CERN Document Server

    Hwang, FK; Winter, P

    1992-01-01

    The Steiner problem asks for a shortest network which spans a given set of points. Minimum spanning networks have been well-studied when all connections are required to be between the given points. The novelty of the Steiner tree problem is that new auxiliary points can be introduced between the original points so that a spanning network of all the points will be shorter than otherwise possible. These new points are called Steiner points - locating them has proved problematic and research has diverged along many different avenues. This volume is devoted to the assimilation of the rich field of intriguing analyses and the consolidation of the fragments. A section has been given to each of the three major areas of interest which have emerged. The first concerns the Euclidean Steiner Problem, historically the original Steiner tree problem proposed by Jarník and Kössler in 1934. The second deals with the Steiner Problem in Networks, which was propounded independently by Hakimi and Levin and has enjoyed the most...

  11. Bicriteria network design problems

    Energy Technology Data Exchange (ETDEWEB)

    Marathe, M.V. [Los Alamos National Lab., NM (United States); Ravi, R. [Princeton Univ., NJ (United States); Sundaram, R. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Ravi, S.S.; Rosenkrantz, D.J.; Hunt, H.B. III [State Univ. of New York, Albany, NY (United States). Dept. of Computer Science

    1997-11-20

    The authors study a general class of bicriteria network design problems. A generic problem in this class is as follows: Given an undirected graph and two minimization objectives (under different cost functions), with a budget specified on the first, find a subgraph from a given subgraph class that minimizes the second objective subject to the budget on the first. They consider three different criteria -- the total edge cost, the diameter and the maximum degree of the network. Here, they present the first polynomial-time approximation algorithms for a large class of bicriteria network design problems for the above mentioned criteria. The following general types of results are presented. First, they develop a framework for bicriteria problems and their approximations. Second, when the two criteria are the same they present a black box parametric search technique. This black box takes in as input an (approximation) algorithm for the criterion situation and generates an approximation algorithm for the bicriteria case with only a constant factor loss in the performance guarantee. Third, when the two criteria are the diameter and the total edge costs they use a cluster based approach to devise approximation algorithms. The solutions violate both the criteria by a logarithmic factor. Finally, for the class of treewidth-bounded graphs, they provide pseudopolynomial-time algorithms for a number of bicriteria problems using dynamic programming. The authors show how these pseudopolynomial-time algorithms can be converted to fully polynomial-time approximation schemes using a scaling technique.

  12. Computational problems in engineering

    CERN Document Server

    Mladenov, Valeri

    2014-01-01

    This book provides readers with modern computational techniques for solving variety of problems from electrical, mechanical, civil and chemical engineering. Mathematical methods are presented in a unified manner, so they can be applied consistently to problems in applied electromagnetics, strength of materials, fluid mechanics, heat and mass transfer, environmental engineering, biomedical engineering, signal processing, automatic control and more.   • Features contributions from distinguished researchers on significant aspects of current numerical methods and computational mathematics; • Presents actual results and innovative methods that provide numerical solutions, while minimizing computing times; • Includes new and advanced methods and modern variations of known techniques that can solve difficult scientific problems efficiently.  

  13. [Halitosis. A common problem].

    Science.gov (United States)

    Laine, M L; Slot, D E; Danser, M M

    2011-12-01

    Halitosis is a frequently occurring problem, the cause of which is generally to be found in the mouth. The challenge for oral health care providers is to diagnose it correctly and treat it effectively. Differential diagnosis is of great importance in making a distinction between halitosis which originates in the mouth and which does not originate in the mouth. Oral halitosis can be treated effectively by good oral health care. Plaque accumulation on the tongue is the most common cause of oral halitosis. Tongue cleansing, possibly in combination with a specific mouth wash, is consequently recommended as an element of oral hygiene care. Other oral health problems, such as periodontal disease, caries and ill-fitting removable dentures should be treated adequately to eliminate these problems as potential causes of halitosis.

  14. Solved problems in electromagnetics

    CERN Document Server

    Salazar Bloise, Félix; Bayón Rojo, Ana; Gascón Latasa, Francisco

    2017-01-01

    This book presents the fundamental concepts of electromagnetism through problems with a brief theoretical introduction at the beginning of each chapter. The present book has a strong  didactic character. It explains all the mathematical steps and the theoretical concepts connected with the development of the problem. It guides the reader to understand the employed procedures to learn to solve the exercises independently. The exercises are structured in a similar way: The chapters begin with easy problems increasing progressively in the level of difficulty. This book is written for students of physics and engineering in the framework of the new European Plans of Study for Bachelor and Master and also for tutors and lecturers. .

  15. Revisiting the Lambert's Problem

    CERN Document Server

    Izzo, Dario

    2014-01-01

    The orbital boundary value problem, also known as Lambert Problem, is revisited. Building upon Lancaster and Blanchard approach, new relations are revealed and a new variable representing all problem classes, under L-similarity, is used to express the time of flight equation. In the new variable, the time of flight curves have two oblique asymptotes and they mostly appear to be conveniently approximated by piecewise continuous lines. We use and invert such a simple approximation to provide an efficient initial guess to an Householder iterative method that is then able to converge, for the single revoltuion case, in only two iterations. The resulting algorithm is compared to Gooding's procedure revealing to be numerically as accurate, while having a smaller computational complexity.

  16. Urban Air Pollution Problems

    Energy Technology Data Exchange (ETDEWEB)

    Sivertsen, B.

    1995-09-01

    This document focuses on the specific problems of urban air pollution related to emissions, urban climate, meteorology, smog potential, specific locations, air pollution measurements and trends. Examples are given with cases from European cities in particular. The north south differences, coastal and inland problems and data from various parts of Europe are presented. Global trends and results from the UNEP programme are used to illustrate the magnitude of the problem. Special emphasis is placed on the impact of different sources and their importance in selected cities. Different types of atmospheric dispersion models, their development and use, is outlined. The importance of local and regional meteorological data for explanation purposes and for estimating and forecasting urban air quality is presented. Finally, monitoring programmes, mapping, impact assessment and optimum abatement strategy planning are illustrated with examples from different areas in the world. 9 refs., 56 figs., 1 table

  17. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...... in Engineering Education. In answer to the requests for visits the Aalborg Centre for Problem Based Learning in Engineering Science and Sustainability under the auspices of UNESCO (UCPBL) a two days programme for visitors is offered two times a year. The workshop is an introduction workshop to the Aalborg PBL...

  18. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  19. A Survey of Transportation Problems

    OpenAIRE

    2014-01-01

    This paper aims at being a guide to understand the different types of transportation problems by presenting a survey of mathematical models and algorithms used to solve different types of transportation modes (ship, plane, train, bus, truck, Motorcycle, Cars, and others) by air, water, space, cables, tubes, and road. Some problems are as follows: bus scheduling problem, delivery problem, combining truck trip problem, open vehicle routing problem, helicopter routing problem, truck loading p...

  20. Problems over Information Systems

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    The problems of estimation of the minimum average time complexity of decision trees and design of efficient algorithms are complex in general case. The upper bounds described in Chap. 2.4.3 can not be applied directly due to large computational complexity of the parameter M(z). Under reasonable assumptions about the relation of P and NP, there are no polynomial time algorithms with good approximation ratio [12, 32]. One of the possible solutions is to consider particular classes of problems and improve the existing results using characteristics of the considered classes. © Springer-Verlag Berlin Heidelberg 2011.

  1. Problems in quantum mechanics

    CERN Document Server

    Kogan, VI; Gersch, Harold

    2011-01-01

    Written by a pair of distinguished Soviet mathematicians, this compilation presents 160 lucidly expressed problems in nonrelativistic quantum mechanics plus completely worked-out solutions. Some were drawn from the authors' courses at the Moscow Institute of Engineering, but most were prepared especially for this book. A high-level supplement rather than a primary text, it constitutes a masterful complement to advanced undergraduate and graduate texts and courses in quantum mechanics.The mathematics employed in the proofs of the problems-asymptotic expansions of functions, Green's functions, u

  2. Calculus problems and solutions

    CERN Document Server

    Ginzburg, A

    2011-01-01

    Ideal for self-instruction as well as for classroom use, this text helps students improve their understanding and problem-solving skills in analysis, analytic geometry, and higher algebra. More than 1,200 problems appear in the text, with concise explanations of the basic notions and theorems to be used in their solution. Many are followed by complete answers; solutions for the others appear at the end of the book. Topics include sequences, functions of a single variable, limit of a function, differential calculus for functions of a single variable, fundamental theorems and applications of dif

  3. Advanced calculus problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of advanced calculus currently av

  4. On current trace problem

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The pricing of electricity trasmission requires determining how much use each generator is making of a transmission line and what is each generator's contribution to the system losses. Such problems cannot be solved by only using Kirchoff's laws. This paper proposes two current decomposition axioms based on which the theories and models are established for the current trace problem. To create an efficient algorithm the graph theory is employed. It is proved that there is no directed circuit in a directed current distribution graph. According to this theorem a very simple and efficient algorithm based on recursive elimination process is suggested. A simple example is used to explain the algorithm.

  5. Matrices in Engineering Problems

    CERN Document Server

    Tobias, Marvin

    2011-01-01

    This book is intended as an undergraduate text introducing matrix methods as they relate to engineering problems. It begins with the fundamentals of mathematics of matrices and determinants. Matrix inversion is discussed, with an introduction of the well known reduction methods. Equation sets are viewed as vector transformations, and the conditions of their solvability are explored. Orthogonal matrices are introduced with examples showing application to many problems requiring three dimensional thinking. The angular velocity matrix is shown to emerge from the differentiation of the 3-D orthogo

  6. Problems in classical mechanics

    CERN Document Server

    Katkar, L N

    2014-01-01

    Problems in classical mechanics presents a lucid treatment of the formulations of Lagrangian, Hamiltonian, and the Principles of Calculus of Variations etc. important for the study of modern physics. The study of classical mechanics prepares students to apply the principles and the mathematical tools to solve real life problems. The book also incorporates and discusses in detail topics such as Central Force Motion, Rigid Body Motion and Canonical Transformations. KEY FEATURES: Around 200 solved examples with complete mathematical theory Around 70 examples given as an exercise to test and develop students understanding The physical interpretation of the Hamiltonian is highlighted

  7. Classic Problems of Probability

    CERN Document Server

    Gorroochurn, Prakash

    2012-01-01

    "A great book, one that I will certainly add to my personal library."—Paul J. Nahin, Professor Emeritus of Electrical Engineering, University of New Hampshire Classic Problems of Probability presents a lively account of the most intriguing aspects of statistics. The book features a large collection of more than thirty classic probability problems which have been carefully selected for their interesting history, the way they have shaped the field, and their counterintuitive nature. From Cardano's 1564 Games of Chance to Jacob Bernoulli's 1713 Golden Theorem to Parrondo's 1996 Perplexin

  8. Minimal Controllability Problems

    OpenAIRE

    Olshevsky, Alex

    2013-01-01

    Given a linear system, we consider the problem of finding a small set of variables to affect with an input so that the resulting system is controllable. We show that this problem is NP-hard; indeed, we show that even approximating the minimum number of variables that need to be affected within a multiplicative factor of $c \\log n$ is NP-hard for some positive $c$. On the positive side, we show it is possible to find sets of variables matching this inapproximability barrier in polynomial time....

  9. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av

  10. The Problem Revisited

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2015-01-01

    Problem-based learning (PBL) is becoming increasingly popular in design educations, but how is it taught and practiced? This paper presents a case study of a three-day workshop that has the purpose of introducing PBL to design students. A theoretical background on PBL and problems in design...... is established and is backing up the case study. The study shows that design engineering and architectural students without experience in PBL in general finds the approach to be beneficial when working on a design challenge in a student team....

  11. Problem Based Game Design

    DEFF Research Database (Denmark)

    Reng, Lars; Schoenau-Fog, Henrik

    2011-01-01

    At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various...... projects and how they learn to analyse, design, and develop for innovation by using it. We will present various cases to exemplify the approach and focus on how the method engages students and aspires for innovation in digital entertainment and games....

  12. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  13. The information recovery problem

    CERN Document Server

    Baccetti, Valentina; Terno, Daniel R

    2016-01-01

    The problem of rescuing unitary matter evolution on a black hole spacetime remains unresolved. We argue that some prominent cures are more troubling than the disease, demonstrate that their central element --- forming of the event horizon before the evaporation begins --- is not necessarily true, and describe a fully coupled matter-gravity system which is manifestly unitary.

  14. Free discontinuity problems

    CERN Document Server

    Pratelli, Aldo

    2016-01-01

    This book presents a series of lectures on three of the best known examples of free discontinuity problems: the Mumford-Shah model for image segmentation, a variational model for the epitaxial growth of thin films, and the sharp interface limit of the Ohta-Kawasaki model for pattern formation in dyblock copolymers.

  15. Managing soil remediation problems.

    Science.gov (United States)

    Okx, J P; Hordijk, L; Stein, A

    1996-12-01

    Soil remediation has only a short history but the problem addressed is a significant one. Cost estimates for the clean-up of contaminated sites in the European Union and the United States are in the order of magnitude of 1,400 billion ECU. Such an enormous operation deserves the best management it can get. Reliable cost estimations per contaminated site are an important prerequisite. This paper addresses the problems related to site-wise estimations.When solving soil remediation problems, we have to deal with a large number of scientific disciplines. Too often solutions are presented from the viewpoint of only one discipline. In order to benefit from the combined disciplinary knowledge and experience, we think that it is necessary to describe the interrelations between these disciplines. This can be realized by developing an adequate model of the desired process which enables to consider and evaluate the essential factors as interdependent components of the total system.The resulting model provides a binding paradigm to the contributing disciplines which will result in improved efficiency and effectivity of the decision and the cost estimation process. In the near future, we will release the "Biosparging and Bioventing Expert Support System", an expert support system for problem owners, consultants and authorities dealing with the design and operation of a biosparging and/or a bioventing system.

  16. The Vehicle Rescheduling Problem

    NARCIS (Netherlands)

    R. Spliet (Remy); A.F. Gabor (Adriana); R. Dekker (Rommert)

    2009-01-01

    textabstractThe capacitated vehicle routing problem is to find a routing schedule describing the order in which geographically dispersed customers are visited to satisfy demand by supplying goods stored at the depot, such that the traveling costs are minimized. In many practical applications, a long

  17. Aeroelastic problems in turbomachines

    Science.gov (United States)

    Bendiksen, Oddvar O.

    1993-01-01

    An overview is given of aeroelastic problems in turbomachines, emphasizing recent research. Unsteady flow in cascade and turbomachinery rotors is discussed, including supersonic and transonic linearized potential flow and nonlinear flow models. Computational and modeling aspects of the flutter of fan and compressor blades are examined. The correlation of the findings with experimental data is considered. Future directions in turbomachinery aeroelasticity are addressed.

  18. The Eight Queens Problem.

    Science.gov (United States)

    Olson, Alton T.

    1993-01-01

    Presents a series of solution methods to the Eight Queens Problem of placing eight queens on a chess board so that no one queen can capture another. Solution methods progress from empirical approaches to the use of computer algorithms. Geometric transformations are used to find other solutions. (MDH)

  19. Expertise in Problem Solving.

    Science.gov (United States)

    1981-05-18

    obstacles that were not encountered previously in puzzle-like problems. Basically, the exact operators to be used are usually not given, the goal state...same height on other side 5. IF something goes down frictionless surface THEN can find acceleration of gravity on the incline using trigonometry 6

  20. The Problem of Population

    Institute of Scientific and Technical Information of China (English)

    刘香情; 钱丹

    2002-01-01

    With the population growing, a lot of problems have come out, Nowadays a lot of tall buildings have been built, but the houses are still very short; A lot of cars and buses have increased, but they are still crowded with people; A lot of schools have been built,

  1. Solving Problems through Circles

    Science.gov (United States)

    Grahamslaw, Laura; Henson, Lisa H.

    2015-01-01

    Several problem-solving interventions that utilise a "circle" approach have been applied within the field of educational psychology, for example, Circle Time, Circle of Friends, Sharing Circles, Circle of Adults and Solution Circles. This research explored two interventions, Solution Circles and Circle of Adults, and used thematic…

  2. Children Solve Problems.

    Science.gov (United States)

    De Bono, Edward

    A group of children were presented with several tasks, including the invention of a sleep machine and a machine to weigh elephants. The tasks were chosen to involve the children in coping with problems of a distinct character. A study of the children's drawings and interpretations shows that children's thinking ability is not very different from…

  3. Unfolding a Problem

    Science.gov (United States)

    Currier, Sarah Cox

    2015-01-01

    In this article, Sarah Currier, a math specialist at Elizabeth Hall International School in Minnesota, describes how she used origami in a deliberate manner to teach content. She shares how she uses paper folding to teach mathematical concepts, reinforce vocabulary, and as a problem-solving model. She also offers ideas for using origami in other…

  4. The CP Violation Problem

    CERN Document Server

    Naboulsi, R

    2003-01-01

    A review on CP violation in the B and K mesons systems is given, which, we hope may familiarize new Belle members in the basic ingredients of this topic, which is one of the most challenging problems of experimental high energy physics.

  5. Team Learning on Messy Problems

    NARCIS (Netherlands)

    Rouwette, E.A.J.A.; Vennix, J.A.M.

    2007-01-01

    Concentrates on procedures used to foster group learning for a particular type of problem, the so-called messy problem. The distinctive feature of messy problems is that the people involved have different ideas on what the problem is or whether there even is a problem. Nevertheless, those involved i

  6. A model for routing problem in quay management problem

    Science.gov (United States)

    Zirour, Mourad; Oughalime, Ahmed; Liong, Choong-Yeun; Ismail, Wan Rosmanira; Omar, Khairuddin

    2014-06-01

    Quadratic Assignment Problem (QAP), like Vehicle Routing Problem, is one of those optimization problems that interests many researchers in the last decades. The Quay Management Problem is a specific problem which could be presented as a QAP which involves a double assignment of customers and products toward loading positions using lifting trucks. This study focuses on the routing problem while delivering the customers' demands. In this problem, lifting trucks will route around the storage sections to collect the products then deliver to the customers who are assigned to specific loading positions. The objective of minimizing the residence time for each customer is sought. This paper presents the problem and the proposed model.

  7. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production...... costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra...... methods. Two important problem variants are the knapsack packing problem and the strip-packing problem. In the knapsack packing problem, each item is given a profit value, and the problem asks for the subset with maximal profit that can be placed within one container. The strip-packing problem asks...

  8. How to solve mathematical problems

    CERN Document Server

    Wickelgren, Wayne A

    1995-01-01

    Seven problem-solving techniques include inference, classification of action sequences, subgoals, contradiction, working backward, relations between problems, and mathematical representation. Also, problems from mathematics, science, and engineering with complete solutions.

  9. Common Sleep Problems (For Teens)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Common Sleep Problems KidsHealth > For Teens > Common Sleep Problems Print ... have emotional problems, like depression. What Happens During Sleep? You don't notice it, of course, but ...

  10. No Problem? No Research, Little Learning ... Big Problem!

    Directory of Open Access Journals (Sweden)

    Fernando Ornelas Marques

    2012-06-01

    Full Text Available The motivation to carry out this study stemmed from the generalized perception that nowadays youth lacks the skills for the 21st century. Especially the high-level competences like critical thinking, problem solving and autonomy. Several tools can help to improve these competences (e.g. the SCRATCH programming language, but, as researchers and educators, we are mostly concerned with the skill to recognize problems. What if we do not find problems to solve? What if we do not even feel the need to find or solve problems? The problem is to recognize the problem; the next step is to equate the problem; finally we have to feel the need to solve it. No need? No invention. Recognizing a problem is probably the biggest problem of everyday life, because we are permanently faced with problems (many ill-defined problems, which we need to identify, equate and solve.

  11. Scattering problems in elastodynamics

    Science.gov (United States)

    Diatta, Andre; Kadic, Muamer; Wegener, Martin; Guenneau, Sebastien

    2016-09-01

    In electromagnetism, acoustics, and quantum mechanics, scattering problems can routinely be solved numerically by virtue of perfectly matched layers (PMLs) at simulation domain boundaries. Unfortunately, the same has not been possible for general elastodynamic wave problems in continuum mechanics. In this Rapid Communication, we introduce a corresponding scattered-field formulation for the Navier equation. We derive PMLs based on complex-valued coordinate transformations leading to Cosserat elasticity-tensor distributions not obeying the minor symmetries. These layers are shown to work in two dimensions, for all polarizations, and all directions. By adaptative choice of the decay length, the deep subwavelength PMLs can be used all the way to the quasistatic regime. As demanding examples, we study the effectiveness of cylindrical elastodynamic cloaks of the Cosserat type and approximations thereof.

  12. Scattering problems in elastodynamics

    CERN Document Server

    Diatta, Andre; Wegener, Martin; Guenneau, Sebastien

    2016-01-01

    In electromagnetism, acoustics, and quantum mechanics, scattering problems can routinely be solved numerically by virtue of perfectly matched layers (PMLs) at simulation domain boundaries. Unfortunately, the same has not been possible for general elastodynamic wave problems in continuum mechanics. In this paper, we introduce a corresponding scattered-field formulation for the Navier equation. We derive PMLs based on complex-valued coordinate transformations leading to Cosserat elasticity-tensor distributions not obeying the minor symmetries. These layers are shown to work in two dimensions, for all polarizations, and all directions. By adaptative choice of the decay length, the deep subwavelength PMLs can be used all the way to the quasi-static regime. As demanding examples, we study the effectiveness of cylindrical elastodynamic cloaks of the Cosserat type and approximations thereof.

  13. The Potluck Problem

    CERN Document Server

    Enumula, Prabodh K

    2008-01-01

    This paper proposes the Potluck Problem as a model for the behavior of independent producers and consumers under standard economic assumptions. We model this by using resource allocation in a multi-agent system in which there is no explicit communication among the agents. The model proposed has many applications in modeling systems like electrical power grids with many consumers and producers, service-on-demand in grid computing and peer-to-peer computing environments, maintaining a good ratio between demand and inventory in supply chain management, etc. It is observed that a rational learning approach is unable to achieve equilibrium or near-equilibrium in the Potluck Problem. Instead, a weighted majority learning algorithm is applied, which does much better in maintaining parity of supply and demand in varying-demand situations.

  14. Problems in Cybersemiotic Modelling

    DEFF Research Database (Denmark)

    Brier, Søren

    2014-01-01

    the Peircean theory of the observer as the phaneroscopic foundation. 4. Cobley points out that both models, as they are combined in Cybersemiotics lacks to integrate a theory of interest and power. They are too consensual in their view on communication. This is a general problem in both theories. Still Luhmann......Going from an empirical to an informational paradigm of cognition and communication, does not really help us to analyze, how the living systems manage to make a meaningful interpretation of environment that is useful for their survival and procreation. Other models are needed. 1. There is von...... Uexküll’s cybernetic-behavioral model, which has the problem of being placed in a Platonic, static worldview. The Umwelt of an animal is a construction limited of its functional realism of survival. It is connected to the species. 2. Ture von Uexküll and Søren Brier both realized that Maturana and Varela...

  15. Medical problems in pregnancy.

    Science.gov (United States)

    Narayan, Bhaskar; Nelson-Piercy, Catherine

    2016-12-01

    The prevalence of medical problems in pregnancy is increasing because of a complex interplay between demographic and lifestyle factors, and developments in modern medicine. Maternal mortality and morbidity resulting from treatable medical conditions, such as venous thromboembolism, epilepsy and autoimmune disease, have not decreased in recent years. This is despite a marked decrease in overall maternal mortality. It is vital that all physicians acquire a basic knowledge and understanding of medical problems in pregnancy. This includes prepregnancy measures such as counselling and optimisation of medical therapy, as well as multidisciplinary management throughout pregnancy and the postpartum period. Prompt recognition and treatment of acute and chronic illness is of clear benefit, and most drugs and many radiological investigations may be used in pregnancy.

  16. Solving A Corrosion Problem

    Science.gov (United States)

    1979-01-01

    The corrosion problem, it turned out, stemmed from the process called electrolysis. When two different metals are in contact, an electrical potential is set up between them; when the metals are surrounded by an electrolyte, or a conducting medium, the resulting reaction causes corrosion, often very rapid corrosion. In this case the different metals were the copper grounding system and the ferry's aluminum hull; the dockside salt water in which the hull was resting served as the electrolyte. After identifying the source of the trouble, the Ames engineer provided a solution: a new wire-and-rod grounding system made of aluminum like the ferry's hull so there would no longer be dissimilar metals in contact. Ames research on the matter disclosed that the problem was not unique to the Golden Gate ferries. It is being experienced by many pleasure boat operators who are probably as puzzled about it as was the Golden Gate Transit Authority.

  17. On current trace problem

    Institute of Scientific and Technical Information of China (English)

    王锡凡; 王秀丽

    2000-01-01

    The pricing of electricity trasmission requires determining how much use each generator is making of a transmission line and what is each generator’s contribution to the system losses. Such problems cannot be solved by only using Kirchoff’s laws. This paper proposes two current decomposition axioms based on which the theories and models are established for the current trace problem. To create an efficient algorithm the graph theory is employed. It is proved that there is no directed circuit in a directed current distribution graph. According to this theorem a very simple and efficient algorithm based on recursive elimination process is suggested. A simple example is used to explain the algorithm .

  18. Problem discourse of textbook

    Directory of Open Access Journals (Sweden)

    Pešić Jelena M.

    2005-01-01

    Full Text Available This paper deals with various reasons for treating the problematisation of textbook discourse as an important aspect of its educational design. These reasons are derived from: the nature of learning process, the nature of scientific knowledge and both motivational and cognitive saint achieved through a problematisation of learning material. Implications drawn from these considerations, along with textbook genre possibilities and constrains, lead us to define some basic strategies of textbook discourse problematisation. They refer to: way of presenting knowledge (problem structuring of text, presenting the history of knowledge and different perspectives; use of specific questions and tasks; metacognitive support of the learning process and specific type of textbook language (dialogical problem focused, language of thinking.

  19. The Boolean Isomorphism problem

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, M. [Indian Institute of Technology, Kanpur (India); Thierauf, T. [Universitaet Ulm (Germany)

    1996-12-31

    We investigate the computational complexity of the Boolean Isomorphism problem (BI): on input of two Boolean formulas F and G decide whether there exists a permutation of the variables of G such that F and G become equivalent. Our main result is a one-round interactive proof for BI, where the verifier has access to an NP oracle. To obtain this, we use a recent result from learning theory by Bshouty et.al. that Boolean formulas can be learned probabilistically with equivalence queries and access to an NP oracle. As a consequence, BI cannot be {sigma}{sup p}{sub 2} complete unless the Polynomial Hierarchy collapses. This solves an open problem posed in [BRS95]. Further properties of BI are shown: BI has And- and Or-functions, the counting version, No. BI, can be computed in polynomial time relative to BI, and BI is self-reducible.

  20. Appreciative Problem Solving

    DEFF Research Database (Denmark)

    Hansen, David

    2012-01-01

    employee strengths in continuou simprovements of the work system. The research question was: “How can Lean problem solving and Appreciative Inquiry be combined for optimized work system innovation?” The research project was carried out as a co-creation process with close cooperation between researcher......Many industrial production work systems have increased in complexity, and their new business model scompete on innovation, rather than low cost.At a medical device production facility committed to Lean Production, a research project was carried out to use Appreciative Inquiry to better engage...... and participants and was documented by qualitative methods. This paper presents an academic literature review on Appreciative Inquiry and problem solving for continuous improvements that did not reveal successful attempts in combining the two.Both the literature and the empirical study showed one of the main...

  1. Appreciative Problem Solving

    OpenAIRE

    Hansen, David

    2012-01-01

    Many industrial production work systems have increased in complexity, and their new business model scompete on innovation, rather than low cost.At a medical device production facility committed to Lean Production, a research project was carried out to use Appreciative Inquiry to better engage employee strengths in continuou simprovements of the work system. The research question was: “How can Lean problem solving and Appreciative Inquiry be combined for optimized work system innovation?”The r...

  2. Problems in quantum mechanics

    CERN Document Server

    Gol'dman, I I

    2010-01-01

    A comprehensive collection of problems of varying degrees of difficulty in nonrelativistic quantum mechanics, with answers and completely worked-out solutions. Among the topics: one-dimensional motion, transmission through a potential barrier, commutation relations, angular momentum and spin, and motion of a particle in a magnetic field. An ideal adjunct to any textbook in quantum mechanics, useful in courses in atomic and nuclear physics, mathematical methods in physics, quantum statistics and applied differential equations. 1961 edition.

  3. The Fukushima Inverse Problem

    OpenAIRE

    Martinez-Camara, Marta; Dokmanic, Ivan; Ranieri, Juri; Scheibler, Robin; Vetterli, Martin; STOHL Andreas

    2013-01-01

    Knowing what amount of radioactive material was released from Fukushima in March 2011 and at what time instants is crucial to assess the risk, the pollution, and to understand the scope of the consequences. Moreover, it could be used in forward simulations to obtain accurate maps of deposition. But these data are often not publicly available. We propose to estimate the emission waveforms by solving an inverse problem. Previous approaches have relied on a detailed expert guess of how the relea...

  4. Creativity and problem Solving

    Directory of Open Access Journals (Sweden)

    René Victor Valqui Vidal

    2004-12-01

    Full Text Available This paper presents some modern and interdisciplinary concepts about creativity and creative processes of special relevance for Operational Research workers. Central publications in the area Creativity-Operational Research are shortly reviewed. Some creative tools and the Creative Problem Solving approach are also discussed. Finally, some applications of these concepts and tools are outlined. Some central references are presented for further study of themes related to creativity or creative tools.

  5. Creativity and Problem Solving

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    2004-01-01

    This paper presents some modern and interdisciplinary concepts about creativity and creative processes of special relevance for Operational Research workers. Central publications in the area Creativity-Operational Research are shortly reviewed. Some creative tools and the Creative Problem Solving...... approach are also discussed. Finally, some applications of these concepts and tools are outlined. Some central references are presented for further study of themes related to creativity or creative tools....

  6. LINGUISTIC INVENTORY PROBLEMS

    OpenAIRE

    CHIH HSUN HSIEH

    2011-01-01

    The work presented in this paper has been motivated primarily by Zadeh's idea of linguistic variables intended to provide rigorous mathematical modeling of natural language and CWW, Computing With Words. This paper reports some modeling of the linguistic inventory problems where CWW have been implemented: linguistic production inventory, linguistic inventory models under linguistic demand and linguistic lead time, linguistic production inventory models based on the preference of a decision ma...

  7. Localized Geometric Query Problems

    CERN Document Server

    Augustine, John; Maheshwari, Anil; Nandy, Subhas C; Roy, Sasanka; Sarvattomananda, Swami

    2011-01-01

    A new class of geometric query problems are studied in this paper. We are required to preprocess a set of geometric objects $P$ in the plane, so that for any arbitrary query point $q$, the largest circle that contains $q$ but does not contain any member of $P$, can be reported efficiently. The geometric sets that we consider are point sets and boundaries of simple polygons.

  8. The Thinnest Path Problem

    Science.gov (United States)

    2016-07-22

    problem in 2-D networks. We then develop two polynomial-time approximation algorithms that offer and approximation ratios for general directed hypergraphs...for both 1-Dand1.5-Dnetworks.This algorithmdoes not require the knowledge of eavesdropper locations and achieves the best performance offered by any...received October 22, 2013; revised February 28, 2014; accepted April 12, 2014; approved by IEEE/ACM TRANSACTIONS ON NETWORKING Ed- itor G. Xue. Date of

  9. Ear problems in swimmers.

    Science.gov (United States)

    Wang, Mao-Che; Liu, Chia-Yu; Shiao, An-Suey; Wang, Tyrone

    2005-08-01

    Acute diffuse otitis externa (swimmer's ear), otomycosis, exostoses, traumatic eardrum perforation, middle ear infection, and barotraumas of the inner ear are common problems in swimmers and people engaged in aqua activities. The most common ear problem in swimmers is acute diffuse otitis externa, with Pseudomonas aeruginosa being the most common pathogen. The symptoms are itching, otalgia, otorrhea, and conductive hearing loss. The treatment includes frequent cleansing of the ear canal, pain control, oral or topical medications, acidification of the ear canal, and control of predisposing factors. Swimming in polluted waters and ear-canal cleaning with cotton-tip applicators should be avoided. Exostoses are usually seen in people who swim in cold water and present with symptoms of accumulated debris, otorrhea and conductive hearing loss. The treatment for exostoses is transmeatal surgical removal of the tumors. Traumatic eardrum perforations may occur during water skiing or scuba diving and present with symptoms of hearing loss, otalgia, otorrhea, tinnitus and vertigo. Tympanoplasty might be needed if the perforations do not heal spontaneously. Patients with chronic otitis media with active drainage should avoid swimming, while patients who have undergone mastoidectomy and who have no cavity problems may swim. For children with ventilation tubes, surface swimming is safe in a clean, chlorinated swimming pool. Sudden sensorineural hearing loss and some degree of vertigo may occur after diving because of rupture of the round or oval window membrane.

  10. Quantum Counterfeit Coin Problems

    CERN Document Server

    Iwama, Kazuo; Raymond, Rudy; Teruyama, Junichi

    2010-01-01

    The counterfeit coin problem requires us to find all false coins from a given bunch of coins using a balance scale. We assume that the balance scale gives us only ``balanced'' or ``tilted'' information and that we know the number k of false coins in advance. The balance scale can be modeled by a certain type of oracle and its query complexity is a measure for the cost of weighing algorithms (the number of weighings). In this paper, we study the quantum query complexity for this problem. Let Q(k,N) be the quantum query complexity of finding all k false coins from the N given coins. We show that for any k and N such that k < N/2, Q(k,N)=O(k^{1/4}), contrasting with the classical query complexity, \\Omega(k\\log(N/k)), that depends on N. So our quantum algorithm achieves a quartic speed-up for this problem. We do not have a matching lower bound, but we show some evidence that the upper bound is tight: any algorithm, including our algorithm, that satisfies certain properties needs \\Omega(k^{1/4}) queries.

  11. The Feline Josephus Problem

    Science.gov (United States)

    Ruskey, Frank; Williams, Aaron

    In the classic Josephus problem, elements 1, 2,...,n are placed in order around a circle and a skip value k is chosen. The problem proceeds in n rounds, where each round consists of traveling around the circle from the current position, and selecting the kth remaining element to be eliminated from the circle. After n rounds, every element is eliminated. Special attention is given to the last surviving element, denote it by j. We generalize this popular problem by introducing a uniform number of lives ℓ, so that elements are not eliminated until they have been selected for the ℓth time. We prove two main results: 1) When n and k are fixed, then j is constant for all values of ℓ larger than the nth Fibonacci number. In other words, the last surviving element stabilizes with respect to increasing the number of lives. 2) When n and j are fixed, then there exists a value of k that allows j to be the last survivor simultaneously for all values of ℓ. In other words, certain skip values ensure that a given position is the last survivor, regardless of the number of lives. For the first result we give an algorithm for determining j (and the entire sequence of selections) that uses O(n 2) arithmetic operations.

  12. Random eigenvalue problems revisited

    Indian Academy of Sciences (India)

    S Adhikari

    2006-08-01

    The description of real-life engineering structural systems is associated with some amount of uncertainty in specifying material properties, geometric parameters, boundary conditions and applied loads. In the context of structural dynamics it is necessary to consider random eigenvalue problems in order to account for these uncertainties. Within the engineering literature, current methods to deal with such problems are dominated by approximate perturbation methods. Some exact methods to obtain joint distribution of the natural frequencies are reviewed and their applicability in the context of real-life engineering problems is discussed. A new approach based on an asymptotic approximation of multi-dimensional integrals is proposed. A closed-form expression for general order joint moments of arbitrary numbers of natural frequencies of linear stochastic systems is derived. The proposed method does not employ the ‘small randomness’ assumption usually used in perturbation based methods. Joint distributions of the natural frequencies are investigated using numerical examples and the results are compared with Monte Carlo simulation.

  13. Characteristics of Problems in Problem-based Learning

    NARCIS (Netherlands)

    N. Sockalingam (Nachamma)

    2010-01-01

    textabstractThis thesis focuses on characteristics of problems in Problem-based Learning (PBL). Problems initiate the students’ learning process in PBL. Several studies have shown that the quality of problems has a positive influence on students’ academic achievement and interest. In addition, the q

  14. Thinking Process of Naive Problem Solvers to Solve Mathematical Problems

    Science.gov (United States)

    Mairing, Jackson Pasini

    2017-01-01

    Solving problems is not only a goal of mathematical learning. Students acquire ways of thinking, habits of persistence and curiosity, and confidence in unfamiliar situations by learning to solve problems. In fact, there were students who had difficulty in solving problems. The students were naive problem solvers. This research aimed to describe…

  15. Obstacle problems in mathematical physics

    CERN Document Server

    Rodrigues, J-F

    1987-01-01

    The aim of this research monograph is to present a general account of the applicability of elliptic variational inequalities to the important class of free boundary problems of obstacle type from a unifying point of view of classical Mathematical Physics.The first part of the volume introduces some obstacle type problems which can be reduced to variational inequalities. Part II presents some of the main aspects of the theory of elliptic variational inequalities, from the abstract hilbertian framework to the smoothness of the variational solution, discussing in general the properties of the free boundary and including some results on the obstacle Plateau problem. The last part examines the application to free boundary problems, namely the lubrication-cavitation problem, the elastoplastic problem, the Signorini (or the boundary obstacle) problem, the dam problem, the continuous casting problem, the electrochemical machining problem and the problem of the flow with wake in a channel past a profile.

  16. Problem Order Implications for Learning

    Science.gov (United States)

    Li, Nan; Cohen, William W.; Koedinger, Kenneth R.

    2013-01-01

    The order of problems presented to students is an important variable that affects learning effectiveness. Previous studies have shown that solving problems in a blocked order, in which all problems of one type are completed before the student is switched to the next problem type, results in less effective performance than does solving the problems…

  17. Analysis of the tracing problem

    Institute of Scientific and Technical Information of China (English)

    Nanfeng Jie; Hui Wang; YunqingSun

    2005-01-01

    Here the tracing problems are researched from two thoroughly different approaches: calculus method and numerical analysis. Generally speaking, the calculus method give a universal qualitative way to deal with such kind of problem, but the numerical analysis method can offer more further quantitative result for such kind of problem. Our research shows the detail results of application of these two methods in tracing problem.

  18. Creating Games from Mathematical Problems

    Science.gov (United States)

    Pinter, Klara

    2011-01-01

    The emphasis on problem solving and problem solving courses has become a standard staple of most teacher preparation programs in mathematics. While opinions differ on whether problem solving should be integrated throughout the preparatory courses or teachers should also have a dedicated course for it, everybody agrees that problem solving skills…

  19. Extended Mixed Vector Equilibrium Problems

    Directory of Open Access Journals (Sweden)

    Mijanur Rahaman

    2014-01-01

    Full Text Available We study extended mixed vector equilibrium problems, namely, extended weak mixed vector equilibrium problem and extended strong mixed vector equilibrium problem in Hausdorff topological vector spaces. Using generalized KKM-Fan theorem (Ben-El-Mechaiekh et al.; 2005, some existence results for both problems are proved in noncompact domain.

  20. XML problem, design, solution

    CERN Document Server

    Amiano, Mitch; Ethier, Kay; Thomas, Michael D

    2006-01-01

    Offering a unique approach to learning XML, this book walks readers through the process of building a complete, functional, end-to-end XML solutionFeatured case study is an online business product catalog that includes reports, data input/output, workflow, stylesheet formatting, RSS feeds, and integration with external services like Google, eBay, and AmazonThe format of presenting a problem and working through the design to come up with a solution enables readers to understand how XML markup allows a business to share data across applications internally or with partners or customers even thoug

  1. Elementary topology problem textbook

    CERN Document Server

    Viro, O Ya; Netsvetaev, N Yu; Kharlamov, V M

    2008-01-01

    This textbook on elementary topology contains a detailed introduction to general topology and an introduction to algebraic topology via its most classical and elementary segment centered at the notions of fundamental group and covering space. The book is tailored for the reader who is determined to work actively. The proofs of theorems are separated from their formulations and are gathered at the end of each chapter. This makes the book look like a pure problem book and encourages the reader to think through each formulation. A reader who prefers a more traditional style can either find the pr

  2. Problems of Massive Gravities

    CERN Document Server

    Deser, S; Ong, Y C; Waldron, A

    2014-01-01

    The method of characteristics is a key tool for studying consistency of equations of motion; it allows issues such as predictability, maximal propagation speed, superluminality, unitarity and acausality to be addressed without requiring explicit solutions. We review this method and its application to massive gravity theories to show the limitations of these models' physical viability: Among their problems are loss of unique evolution, superluminal signals, matter coupling inconsistencies and micro-acausality (propagation of signals around local closed timelike/causal curves). We extend previous no-go results to the entire three-parameter range of massive gravity theories. It is also argued that bimetric models suffer a similar fate.

  3. Planning and Problem Solving

    Science.gov (United States)

    1982-10-01

    Artificial Intelig ~ence (Vol. III, edited by Paul R. Cohen and’ Edward A.. Feigenbaum)’, The chapter was written B’ Paul Cohen, with contributions... Artificial Intelligence (Vol. III, edited by Paul R. Cohen and EdWard A. Feigenbaum). The chapter was written by Paul R. Cohen, with contributions by Stephen...Wheevoats"EntermdI’ Planning and Problem ’Solving by Paul R. Cohen Chaptb-rXV-of Volumec III’of the Handbook of Artificial Intelligence edited by Paul R

  4. The Gilbert Arborescence Problem

    CERN Document Server

    Volz, M G; Ras, C J; Swanepoel, K J; Thomas, D A

    2009-01-01

    We investigate the problem of designing a minimum cost flow network interconnecting n sources and a single sink, each with known locations and flows. The network may contain other unprescribed nodes, known as Steiner points. For concave increasing cost functions, a minimum cost network of this sort has a tree topology, and hence can be called a Minimum Gilbert Arborescence (MGA). We characterise the local topological structure of Steiner points in MGAs, showing, in particular, that for a wide range of metrics and cost-functions the degree of each Steiner point is 3.

  5. The Container Stowage Problem

    DEFF Research Database (Denmark)

    Janstrup, Kira; Rose, Trine Høyer; Andersen, Kent Høj

    The main purpose of this project is to use integer programming to create a model that minimizes the costs for container transportation by ship. To make the model as realistic as possible it will be based on information from a large shipping company about the vessel layout and container types....... In addition to our project two other projects are made where an optimal solution to the container stowage problem also is tried to be found, but by using constraint programming and local search instead respectively. We will therefore in the end compare these three methods and the achieved results on fastness...

  6. The Container Stowage Problem

    DEFF Research Database (Denmark)

    Janstrup, Kira

    2010-01-01

    The main purpose of this project is to use integer programming to create a model that minimizes the costs for container transportation by ship. To make the model as realistic as possible it will be based on information from a large shipping company about the vessel layout and container types....... In addition to our project two other projects are made where an optimal solution to the container stowage problem also is tried to be found, but by using constraint programming and local search instead respectively. We will therefore in the end compare these three methods and the achieved results on fastness...

  7. Double pendulum contact problem

    Directory of Open Access Journals (Sweden)

    Špička J.

    2014-06-01

    Full Text Available The work concerns contact problems focused on biomechanical systems modelled by a multibody approach. The example is modelling of impact between a body and an infrastructure. The paper firstly presents algorithm for minimum distance calculation. An analytical approach using a tangential plain perpendicular to an initial one is applied. Contact force generated during impact is compared by three different continuous force models, namely the Hertz’s model, the spring-dashpot model and the non-linear damping model. In order to identify contact parameters of these particular models, the method of numerical optimization is used. Purpose of this method is to find the most corresponding results of numerical simulation to the original experiment. Numerical optimization principle is put upon a bouncing ball example for the purpose of evaluation of desirable contact force parameters. The contact modelling is applied to a double pendulum problem. The equation of motion of the double pendulum system is derived using Lagrange equation of the second kind with multipliers, respecting the contact phenomena. Applications in biomechanical research are hinted at arm gravity motion and a double pendulum impact example.

  8. Some Undecidable Problems on Approximability of NP Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    黄雄

    1996-01-01

    In this paper some undecidable problems on approximability of NP optimization problems are investigated.In particular,the following problems are all undecidable:(1) Given an NP optimization problem,is it approximable in polynomial time?(2)For any polynomial-time computable function r(n),given a polynomial time approximable NP optimization problem,has it a polynomial-time approximation algorithm with approximation performance ratio r(n) (r(n)-approximable)?(3)For any polynomial-time computable functions r(n),r'(n),where r'(n)problem,is it r'(n)-approximable?

  9. Understanding the Problem. Problem Solving and Communication Activity Series. The Math Forum: Problems of the Week

    Science.gov (United States)

    Math Forum @ Drexel, 2009

    2009-01-01

    Different techniques for understanding a problem can lead to ideas for never-used-before solutions. Good problem-solvers use a problem-solving strategy and may come back to it frequently while they are working on the problem to refine their strategy, see if they can find better solutions, or find other questions. Writing is an integral part of…

  10. Abstraction and Problem Reformulation

    Science.gov (United States)

    Giunchiglia, Fausto

    1992-01-01

    In work done jointly with Toby Walsh, the author has provided a sound theoretical foundation to the process of reasoning with abstraction (GW90c, GWS9, GW9Ob, GW90a). The notion of abstraction formalized in this work can be informally described as: (property 1), the process of mapping a representation of a problem, called (following historical convention (Sac74)) the 'ground' representation, onto a new representation, called the 'abstract' representation, which, (property 2) helps deal with the problem in the original search space by preserving certain desirable properties and (property 3) is simpler to handle as it is constructed from the ground representation by "throwing away details". One desirable property preserved by an abstraction is provability; often there is a relationship between provability in the ground representation and provability in the abstract representation. Another can be deduction or, possibly inconsistency. By 'throwing away details' we usually mean that the problem is described in a language with a smaller search space (for instance a propositional language or a language without variables) in which formulae of the abstract representation are obtained from the formulae of the ground representation by the use of some terminating rewriting technique. Often we require that the use of abstraction results in more efficient .reasoning. However, it might simply increase the number of facts asserted (eg. by allowing, in practice, the exploration of deeper search spaces or by implementing some form of learning). Among all abstractions, three very important classes have been identified. They relate the set of facts provable in the ground space to those provable in the abstract space. We call: TI abstractions all those abstractions where the abstractions of all the provable facts of the ground space are provable in the abstract space; TD abstractions all those abstractions wllere the 'unabstractions' of all the provable facts of the abstract space are

  11. The Astropy Problem

    CERN Document Server

    Muna, Demitri; Allen, Alice; Ashley, Richard; Asmus, Daniel; Azzollini, Ruyman; Bannister, Michele; Beaton, Rachael; Benson, Andrew; Berriman, G Bruce; Bilicki, Maciej; Boyce, Peter; Bridge, Joanna; Cami, Jan; Cangi, Eryn; Chen, Xian; Christiny, Nicholas; Clark, Christopher; Collins, Michelle; Comparat, Johan; Cook, Neil; Croton, Darren; Davids, Isak Delberth; Depagne, Éric; Donor, John; Santos, Leonardo A dos; Douglas, Stephanie; Du, Alan; Durbin, Meredith; Erb, Dawn; Faes, Daniel; Fernández-Trincado, J G; Foley, Anthony; Fotopoulou, Sotiria; Frimann, Søren; Frinchaboy, Peter; Garcia-Dias, Rafael; Gawryszczak, Artur; George, Elizabeth; Gonzalez, Sebastian; Gordon, Karl; Gorgone, Nicholas; Gosmeyer, Catherine; Grasha, Katie; Greenfield, Perry; Grellmann, Rebekka; Guillochon, James; Gurwell, Mark; Haas, Marcel; Hagen, Alex; Haggard, Daryl; Haines, Tim; Hall, Patrick; Hellwing, Wojciech; Herenz, Edmund Christian; Hinton, Samuel; Hlozek, Renee; Hoffman, John; Holman, Derek; Holwerda, Benne Willem; Horton, Anthony; Hummels, Cameron; Jacobs, Daniel; Jensen, Jens Juel; Jones, David; Karick, Arna; Kelley, Luke; Kenworthy, Matthew; Kitchener, Ben; Klaes, Dominik; Kohn, Saul; Konorski, Piotr; Krawczyk, Coleman; Kuehn, Kyler; Kuutma, Teet; Lam, Michael T; Lane, Richard; Liske, Jochen; Lopez-Camara, Diego; Mack, Katherine; Mangham, Sam; Mao, Qingqing; Marsh, David J E; Mateu, Cecilia; Maurin, Loïc; McCormac, James; Momcheva, Ivelina; Monteiro, Hektor; Mueller, Michael; Munoz, Roberto; Naidu, Rohan; Nelson, Nicholas; Nitschelm, Christian; North, Chris; Nunez-Iglesias, Juan; Ogaz, Sara; Owen, Russell; Parejko, John; Patrício, Vera; Pepper, Joshua; Perrin, Marshall; Pickering, Timothy; Piscionere, Jennifer; Pogge, Richard; Poleski, Radek; Pourtsidou, Alkistis; Price-Whelan, Adrian M; Rawls, Meredith L; Read, Shaun; Rees, Glen; Rein, Hanno; Rice, Thomas; Riemer-Sørensen, Signe; Rusomarov, Naum; Sanchez, Sebastian F; Santander-García, Miguel; Sarid, Gal; Schoenell, William; Scholz, Aleks; Schuhmann, Robert L; Schuster, William; Scicluna, Peter; Seidel, Marja; Shao, Lijing; Sharma, Pranav; Shulevski, Aleksandar; Shupe, David; Sifón, Cristóbal; Simmons, Brooke; Sinha, Manodeep; Skillen, Ian; Soergel, Bjoern; Spriggs, Thomas; Srinivasan, Sundar; Stevens, Abigail; Streicher, Ole; Suchyta, Eric; Tan, Joshua; Telford, O Grace; Thomas, Romain; Tonini, Chiara; Tremblay, Grant; Tuttle, Sarah; Urrutia, Tanya; Vaughan, Sam; Verdugo, Miguel; Wagner, Alexander; Walawender, Josh; Wetzel, Andrew; Willett, Kyle; Williams, Peter K G; Yang, Guang; Zhu, Guangtun; Zonca, Andrea

    2016-01-01

    The Astropy Project (http://astropy.org) is, in its own words, "a community effort to develop a single core package for Astronomy in Python and foster interoperability between Python astronomy packages." For five years this project has been managed, written, and operated as a grassroots, self-organized, almost entirely volunteer effort while the software is used by the majority of the astronomical community. Despite this, the project has always been and remains to this day effectively unfunded. Further, contributors receive little or no formal recognition for creating and supporting what is now critical software. This paper explores the problem in detail, outlines possible solutions to correct this, and presents a few suggestions on how to address the sustainability of general purpose astronomical software.

  12. Sleep problems in children.

    Science.gov (United States)

    Baweja, R; Calhoun, S; Baweja, R; Singareddy, R

    2013-10-01

    Sleep complaints and sleep disorders are common during childhood and adolescence. The impact of not getting enough sleep may affect children's' physical health as well emotional, cognitive and social development. Insomnia, sleep-disordered breathing, parasomnias and sleep disturbances associated with medical and psychiatric disorders are some of the commonly encountered sleep disorders in this age group. Changes in sleep architecture and the amount of sleep requirement associated with each stage of development should be considered during an evaluation of sleep disorders in children. Behavioral treatments should be used initially wherever possible especially considering that most pharmacologic agents used to treat pediatric sleep disorders are off-label. In this review we address the most common sleep problems in children/adolescents as they relate to prevalence, presentation and symptoms, evaluation and management.

  13. The Password Problem

    Energy Technology Data Exchange (ETDEWEB)

    Walkup, Elizabeth [Stanford Univ., CA (United States)

    2016-06-01

    Passwords are an ubiquitous, established part of the Internet today, but they are also a huge security headache. Single sign-on, OAuth, and password managers are some of the solutions to this problem. OAuth is a new, popular method that allows people to use large, common authentication providers for many web applications. However, it comes at the expense of some privacy: OAuth makes users easy to track across websites, applications, and devices. Password managers put the power in the hands of the users, but this vulnerability survey reveals that you have to be extremely careful which program you choose. All in all, password managers are the solution of choice for home users and small organizations, but large companies will probably want to invest in their own SSO solutions.

  14. The supersymmetric flavor problem

    CERN Document Server

    Dimopoulos, Savas K; Dimopoulos, Savas; Sutter, Dave

    1995-01-01

    The supersymmetric SU(3)\\times SU(2)\\times U(1) theory with minimal particle content and general soft supersymmetry breaking terms has 110 physical parameters in its flavor sector: 30 masses, 39 real mixing angles and 41 phases. The absence of an experimental indication for the plethora of new parameters places severe constraints on theories posessing Planck or GUT-mass particles and suggests that theories of flavor conflict with naturalness. We illustrate the problem by studying the processes \\mu \\rightarrow e + \\gamma and K^0 - \\bar{K}^0 mixing which are very sensitive probes of Planckian physics: a single Planck mass particle coupled to the electron or the muon with a Yukawa coupling comparable to the gauge coupling typically leads to a rate for \\mu \\rightarrow e + \\gamma exceeding the present experimental limits. A possible solution is that the messengers which transmit supersymmetry breaking to the ordinary particles are much lighter than M_{\\rm Planck}.

  15. The Three Hat Problem

    CERN Document Server

    Benson, Brian

    2007-01-01

    In this paper we study the Three Hat Problem which appeared in Puzzle Corner of the Technology Review magazine. This puzzle gives a scenario in which three players wearing hats are sitting together and each hat can be seen by everyone except the player that is wearing that hat. Each player is told that all of the hats contain a positive integer and that two of the integers add to the third. In an ordered, turn-wise, modular fashion, each player truthfully states whether or not he knows his integer. We give a strategy which allows for one of the players to solve for his integer for all possible integer configurations of the puzzle and prove it is the optimal such strategy.

  16. The four bars problem

    Science.gov (United States)

    Mauroy, Alexandre; Taslakian, Perouz; Langerman, Stefan; Jungers, Raphaël

    2016-09-01

    A four-bar linkage is a mechanism consisting of four rigid bars which are joined by their endpoints in a polygonal chain and which can rotate freely at the joints (or vertices). We assume that the linkage lies in the 2-dimensional plane so that one of the bars is held horizontally fixed. In this paper we consider the problem of reconfiguring a four-bar linkage using an operation called a pop. Given a four-bar linkage, a pop reflects a vertex across the line defined by its two adjacent vertices along the polygonal chain. Our main result shows that for certain conditions on the lengths of the bars, the neighborhood of any configuration that can be reached by smooth motion can also be reached by pops. The proof relies on the fact that pops are described by a map on the circle with an irrational number of rotation.

  17. The problem of Millenarism

    Directory of Open Access Journals (Sweden)

    Erik af Edholm

    1975-01-01

    Full Text Available The myth of the recurrence of the golden age after a period of accelerating miseries ("messianic woes" in the near future is of course not peculiar to the chiliasm of the European later middle ages. On the contrary, it belongs to the basic eschatological themes of millenarism in general. These themes are found also in Hindu tradition. To determine those general characteristics of traditional Hindu society which can contribute to an explanation of the relative unimportance of peasant rebellions and the lack of chiliastic mass movements, is not a problem to be solved within the field of the history of religions. For example, the egalitarian message of the bhakti saints, disputing the hierarchy, did not preclude that the salvationist sects did adapt to the caste system. The religious movements contributed to and gave ideological form to adjustments within the existing social structure. Obviously there was little need for millenarism in this process.

  18. The landslide problem

    Institute of Scientific and Technical Information of China (English)

    G. Shanmugam

    2015-01-01

    The synonymous use of the general term“landslide”, with a built-in reference to a sliding motion, for all varieties of mass-transport deposits (MTD), which include slides, slumps, debrites, topples, creeps, debris avalanches etc. in subaerial, sublacustrine, sub-marine, and extraterrestrial environments has created a multitude of conceptual and nomen-clatural problems. In addition, concepts of triggers and long-runout mechanisms of mass movements are loosely applied without rigor. These problems have enormous implications for studies in process sedimentology, sequence stratigraphy, palaeogeography, petroleum geol-ogy, and engineering geology. Therefore, the objective of this critical review is to identify key problems and to provide conceptual clarity and possible solutions. Speciifc issues are the fol-lowing:(1) According to“limit equilibrium analyses”in soil mechanics, sediment failure with a sliding motion is initiated over a shear surface when the factor of safety for slope stability (F) is less than 1. However, the term landslide is not meaningful for debris lfows with a lfowing mo-tion. (2) Sliding motion can be measured in oriented core and outcrop, but such measurement is not practical on seismic proifles or radar images. (3) Although 79 MTD types exist in the geological and engineering literature, only slides, slumps, and debrites are viable depositional facies for interpreting ancient stratigraphic records. (4) The use of the term landslide for high-velocity debris avalanches is inappropriate because velocities of mass-transport processes cannot be determined in the rock record. (5) Of the 21 potential triggering mechanisms of sediment failures, frequent short-term events that last for only a few minutes to several hours or days (e.g., earthquakes, meteorite impacts, tsunamis, tropical cyclones, etc.) are more relevant in controlling deposition of deep-water sands than sporadic long-term events that last for thousands to millions of years (e

  19. Gaussian quantum marginal problem

    CERN Document Server

    Eisert, J; Sanders, B C; Tyc, T

    2007-01-01

    The quantum marginal problem asks what local spectra are consistent with a given state of a composite quantum system. This setting, also referred to as the question of the compatibility of local spectra, has several applications in quantum information theory. Here, we introduce the analogue of this statement for Gaussian states for any number of modes, and solve it in generality, for pure and mixed states, both concerning necessary and sufficient conditions. Formally, our result can be viewed as an analogue of the Sing-Thompson Theorem (respectively Horn's Lemma), characterizing the relationship between main diagonal elements and singular values of a complex matrix: We find necessary and sufficient conditions for vectors (d1, ..., dn) and (c1, ..., cn) to be the symplectic eigenvalues and symplectic main diagonal elements of a strictly positive real matrix, respectively. More physically speaking, this result determines what local temperatures or entropies are consistent with a pure or mixed Gaussian state of ...

  20. Routing and scheduling problems

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander

    be that the objects routed have an availability time window and a delivery time window or that locations on the path have a service time window. When routing moving transportation objects such as vehicles and vessels schedules are made in connection with the routing. Such schedules represent the time for the presence...... to a destination on a predefined network, the routing and scheduling of vessels in a liner shipping network given a demand forecast to be covered, the routing of manpower and vehicles transporting disabled passengers in an airport and the vehicle routing with time windows where one version studied includes edge...... of a connection between two locations. This could be an urban bus schedule where busses are routed and this routing creates a bus schedule which the passengers between locations use. In this thesis various routing and scheduling problems will be presented. The topics covered will be routing from an origin...

  1. Instrumentation problems for physicians.

    Science.gov (United States)

    Turner, G O

    1980-01-01

    The physician has, for whatever reasons, diminished his or her level of involvement on the team dedicated to developing, refining, and evaluating medical technology. As a result, the challenge confronting the physician and the technology development team today is to orchestrate a team structure that will ensure the greatest input and commitment from physicians and other professionals during current and future technology development. The charges of cost escalation and dehumanization in our system of health care delivery will also be discussed, as will the lack of, or confusion about, access to data concerning cost of a given instrument, and fuzzy semantics and perspectives on technology and instrumentation. The author suggests answers to, or means to ameliorate, the problems.

  2. A stochastic control problem

    Directory of Open Access Journals (Sweden)

    William Margulies

    2004-11-01

    Full Text Available In this paper, we study a specific stochastic differential equation depending on a parameter and obtain a representation of its probability density function in terms of Jacobi Functions. The equation arose in a control problem with a quadratic performance criteria. The quadratic performance is used to eliminate the control in the standard Hamilton-Jacobi variational technique. The resulting stochastic differential equation has a noise amplitude which complicates the solution. We then solve Kolmogorov's partial differential equation for the probability density function by using Jacobi Functions. A particular value of the parameter makes the solution a Martingale and in this case we prove that the solution goes to zero almost surely as time tends to infinity.

  3. Wicked Problem Solvers.

    Science.gov (United States)

    Edmondson, Amy C

    2016-06-01

    Companies today increasingly rely on teams that span many industries for radical innovation, especially to solve "wicked problems." So leaders have to understand how to promote collaboration when roles are uncertain, goals are shifting, expertise and organizational cultures are varied, and participants have clashing or even antagonistic perspectives. HBS professor Amy Edmondson has studied more than a dozen cross-industry innovation projects, among them the creation of a new city, a mango supply-chain transformation, and the design and construction of leading-edge buildings. She has identified the leadership practices that make successful cross-industry teams work: fostering an adaptable vision, promoting psychological safety, enabling knowledge sharing, and encouraging collaborative innovation. Though these practices are broadly familiar, their application within cross-industry teams calls for unique leadership approaches that combine flexibility, open-mindedness, humility, and fierce resolve.

  4. On Brauer's problem 21

    Institute of Scientific and Technical Information of China (English)

    ZENG; Jiwen(

    2001-01-01

    [1]Brauer, R., Representations of finite groups, in Lectures in Mathematics, Vol. 1, New York: Wiley, 1963, 133-175.[2]Feit, W. , The Representation Theory of Finite Groups, Amsterdam: North-Holland, 1982.[3]Külshammer, B., Landau's theorem for p-blocks of p-solvable groups, J. Reine Angew. Math., 1990, 404: 189-191.[4]Külshammer B., Robinson, G. R., Alperin-Mckey implies Brauer's problem 21, J. Algebra, 1996, 180: 208-210.[5]Zeng Jiwen, An inequality of block invariants, J. Algebra, 1997, 193: 724-727.[6]Nagao, N., Tsushima, Y., Representations of Finite Groups, New York: Academic Press, Inc., 1989.[7]Robinson, G. R., On Brauer's k(B) problem, J. Algebra, 1992, 147: 450-455.[8]Zhang Jiping, p-regular orbits and p-blocks of defect zero, Comm. Algebra, 1993, 21(1): 299-307.[9]Xu Minyao, Huang ,Jianhua, An Introduction to Finite Groups (in Chinese), Vol. 2, Beijing: Science Press, 1999.[10]Alperin, ,J. L. , Weights for finite group, Proc. Sympos. Pure Math. , 1987, 47: 369-379.[11]Puig, L., Usami, Y., Perfect isometrics for blocks with Abelian defect groups and cyclic four inertial quotients, J. Algebra,1996.[12]Dade, E. C., Counting characters in blocks, I, Invent. Math., 1992, 109: 187-210.

  5. Fostering Information Problem Solving Skills Through Completion Problems and Prompts

    NARCIS (Netherlands)

    Frerejean, Jimmy; Brand-Gruwel, Saskia; Kirschner, Paul A.

    2012-01-01

    Frerejean, J., Brand-Gruwel, S., & Kirschner, P. A. (2012, September). Fostering Information Problem Solving Skills Through Completion Problems and Prompts. Poster presented at the EARLI SIG 6 & 7 "Instructional Design" and "Learning and Instruction with Computers", Bari, Italy.

  6. Fostering information problem solving skills through completion problems and prompts

    NARCIS (Netherlands)

    Frerejean, Jimmy; Brand-Gruwel, Saskia; Kirschner, Paul A.

    2012-01-01

    Frerejean, J., Brand-Gruwel, S., & Kirschner, P. A. (2012, November). Fostering information problem solving skills through completion problems and prompts. Poster presented at the ICO Fall School 2012, Girona, Spain.

  7. Mechanics problems in undergraduate physics

    CERN Document Server

    Strelkov, S P

    2013-01-01

    Problems in Undergraduate Physics, Volume I: Mechanics focuses on solutions to problems in physics. The book first discusses the fundamental problems in physics. Topics include laws of conservation of momentum and energy; dynamics of a point particle in circular motion; dynamics of a rotating rigid body; hydrostatics and aerostatics; and acoustics. The text also offers information on solutions to problems in physics. Answers to problems in kinematics, statics, gravity, elastic deformations, vibrations, and hydrostatics and aerostatics are discussed. Solutions to problems related to the laws of

  8. Problem effectiveness in a course using problem-based learning

    NARCIS (Netherlands)

    D.H.J.M. Dolmans (Diana); W.H. Gijselaers (Wim); H.G. Schmidt (Henk); S.B. van der Meer

    1993-01-01

    textabstractBackground. Problem-based learning (PBL) emphasizes active generation of learning issues by students. Both students and reachers, however, tend to worry that not all important knowledge will be acquired. To explore this question, problem effectiveness (i.e., for each problem, the degree

  9. Problem Solving through an Optimization Problem in Geometry

    Science.gov (United States)

    Poon, Kin Keung; Wong, Hang-Chi

    2011-01-01

    This article adapts the problem-solving model developed by Polya to investigate and give an innovative approach to discuss and solve an optimization problem in geometry: the Regiomontanus Problem and its application to football. Various mathematical tools, such as calculus, inequality and the properties of circles, are used to explore and reflect…

  10. ON VECTOR NETWORK EQUILIBRIUM PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Guangya CHEN

    2005-01-01

    In this paper we define a concept of weak equilibrium for vector network equilibrium problems.We obtain sufficient conditions of weak equilibrium points and establish relation with vector network equilibrium problems and vector variational inequalities.

  11. Duality in constrained location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1987-01-01

    The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated.......The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated....

  12. On the graph turnpike problem

    KAUST Repository

    Feder, Tomás

    2009-06-01

    Results on graph turnpike problem without distinctness, including its NP-completeness, and an O(m+n log n) algorithm, is presented. The usual turnpike problem has all pairwise distances given, but does not specify which pair of vertices w e corresponds to. There are two other problems that can be viewed as special cases of the graph turnpike problem, including the bandwidth problem and the low-distortion graph embedding problem. The aim for the turnpike problem in the NP-complete is to orient the edges with weights w i in either direction so that when the whole cycle is transversed in the real line, it returns to a chosen starting point for the cycle. An instance of the turnpike problem with or without distinctness is uniquely mappable if there exists at most one solution up to translation and choice of orientation.

  13. Dementia - behavior and sleep problems

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000029.htm Dementia - behavior and sleep problems To use the sharing ... on this page, please enable JavaScript. People with dementia , often have certain problems when it gets dark ...

  14. Sherlock Holmes, Master Problem Solver.

    Science.gov (United States)

    Ballew, Hunter

    1994-01-01

    Shows the connections between Sherlock Holmes's investigative methods and mathematical problem solving, including observations, characteristics of the problem solver, importance of data, questioning the obvious, learning from experience, learning from errors, and indirect proof. (MKR)

  15. Direct Problems and Inverse Problems in Biometric Systems

    Directory of Open Access Journals (Sweden)

    Mihailescu Marius Iulian

    2013-10-01

    Full Text Available The article purpose is to describe the two sides of biometrics technologies, direct problems and inverse problems. The advance that we face today in field of Information Technology makes Information Security an inseparable part. The authentication has a huge role when we deal about security. The problems that can appear in implementing and developing biometrics systems is raising many problems, and one of the goal of this article is to focus on direct and inverse problems which is a new and challenging branch in biometrics technologies.

  16. Hull properties in location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1983-01-01

    Some properties of the solution set for single and multifacility continuous location problems with lp distances are given. A set reduction algorithm is developed for problems in k-dimensional space having rectangular distances.......Some properties of the solution set for single and multifacility continuous location problems with lp distances are given. A set reduction algorithm is developed for problems in k-dimensional space having rectangular distances....

  17. Smoothing of mixed complementarity problems

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, S.A.; More, J.J. [Argonne National Lab., IL (United States). Mathematics and Computer Science Div.

    1995-09-01

    The authors introduce a smoothing approach to the mixed complementarity problem, and study the limiting behavior of a path defined by approximate minimizers of a nonlinear least squares problem. The main result guarantees that, under a mild regularity condition, limit points of the iterates are solutions to the mixed complementarity problem. The analysis is applicable to a wide variety of algorithms suitable for large-scale mixed complementarity problems.

  18. The Split Variational Inequality Problem

    CERN Document Server

    Censor, Yair; Reich, Simeon

    2010-01-01

    We propose a new variational problem which we call the Split Variational Inequality Problem (SVIP). It entails finding a solution of one Variational Inequality Problem (VIP), the image of which under a given bounded linear transformation is a solution of another VIP. We construct iterative algorithms that solve such problems, under reasonable conditions, in Hilbert space and then discuss special cases, some of which are new even in Euclidean space.

  19. Frames and extension problems II

    DEFF Research Database (Denmark)

    Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

    2014-01-01

    This article is a follow-up on the article Frames and Extension Problems I. Here we will go into more recent progress on the topic and also present some open problems.......This article is a follow-up on the article Frames and Extension Problems I. Here we will go into more recent progress on the topic and also present some open problems....

  20. Bronchiectasis: still a problem

    Institute of Scientific and Technical Information of China (English)

    Wang Zengli

    2014-01-01

    Objective The purpose of this descriptive review was to delineate the current knowledge of bronchiectasis in terms of prevalence,burden of disease,pathophysiology,and management.Data sources The National Library of Medicines MEDLINE and PubMed database (2005-2013) were used to conduct a search using the keyword term "bronchiectasis".The references for articles being considered for inclusion were searched from additional sources such as conference proceedings.Study selection Criteria for inclusion of articles included data outlining epidemiology,pathogenesis,diagnosis,and evidence-based guidelines for management of bronchiectasis.In assessing the quality of the articles,factors such as size of the population studied,clinical setting of the study,and whether or not the studies were prospective or retrospective were taken into consideration.Review articles were also included in our data collection.Results Despite many advances in modem medicine,bronchiectasis still remains a significant public health problem in developed countries and the developing world.It carries a significant burden worldwide in terms of morbidity and mortality,as well as financially to the affected population.In addition,bronchiectasis may associate with chronic airflow obstruction,regardless of smoking status.Conclusions Bronchiectasis is a debilitating illness responsible for significant morbidity with a poor health-related quality of life.The condition has a substantial socioeconomic cost because both primary and secondary healthcare resources are frequently used and periods of sick leave are common.

  1. Fibromyalgia and sexual problems

    Directory of Open Access Journals (Sweden)

    P. Scarpellini

    2012-09-01

    Full Text Available The aim of this review was to describe the recent literature concerning sexual dysfunction in fibromyalgic patients. To this end, we used the common online databases PubMed, MEDLINE and EMBASE (up to June 2012 and searched for the key words fibromyalgia (FM and sexual dysfunction. All the studies examined underlined that FM is strictly associated with sexual dysfunction in women. The major findings observed were related to a decreased sexual desire and arousal, decreased experience of orgasm, and in some studies an increase in genital pain. The psychological aspects, together with the stress related to the constant presence of chronic widespread pain, fatigue and sleep disturbances, are certainly a major factor that adversely affects the sexuality of the patient with FM. Moreover, the drugs most commonly used in these cases may interfere negatively on the sexuality and sexual function of these patients. Therefore, the therapeutic intervention should be targeted and the side effects should be weighed up against the positive effects. It is of the utmost importance to recognise the problem of sexuality and sexual dysfunction in a more complex form of its expression and undertake a multidisciplinary therapeutic intervention to improve the quality of FM patients’ life.

  2. Anglers' fishing problem

    CERN Document Server

    Karpowicz, Anna

    2011-01-01

    The considered model will be formulated as related to "the fishing problem" even if the other applications of it are much more obvious. The angler goes fishing. He uses various techniques and he has at most two fishing rods. He buys a fishing ticket for a fixed time. The fishes are caught with the use of different methods according to the renewal processes. The fishes' value and the inter arrival times are given by the sequences of independent, identically distributed (i.i.d.) random variables with the known distribution functions. It forms the marked renewal--reward process. The angler's measure of satisfaction is given by the difference between the utility function, depending on the value of the fishes caught, and the cost function connected with the time of fishing. In this way, the angler's relative opinion about the methods of fishing is modelled. The angler's aim is to have as much satisfaction as possible and additionally he has to leave the lake before a fixed moment. Therefore his goal is to find two...

  3. Conceptual Problems in Cosmology

    CERN Document Server

    Vieira, F J Amaral

    2011-01-01

    In this essay a critical review of present conceptual problems in current cosmology is provided from a more philosophical point of view. In essence, a digression on how could philosophy help cosmologists in what is strictly their fundamental endeavor is presented. We start by recalling some examples of enduring confrontations among philosophers and physicists on what could be contributed by the formers to the day-time striving of the second ones. Then, a short review of the standard model Friedmann-Lema\\^itre-Robertson-Walter (FLRW) of cosmology is given. It seems apparent that cosmology is living a golden age with the advent of observations of high precision. Nonetheless, a critical revisiting of the direction in which it should go on appears also needed, for misconcepts like "quantum backgrounds for cosmological classical settings" and "quantum gravity unification" have not been properly constructed up-to-date. Thus, knowledge-building in cosmology, more than in any other field, should begin with visions of...

  4. Large Spectral Library Problem

    Energy Technology Data Exchange (ETDEWEB)

    Chilton, Lawrence K.; Walsh, Stephen J.

    2008-10-03

    Hyperspectral imaging produces a spectrum or vector at each image pixel. These spectra can be used to identify materials present in the image. In some cases, spectral libraries representing atmospheric chemicals or ground materials are available. The challenge is to determine if any of the library chemicals or materials exist in the hyperspectral image. The number of spectra in these libraries can be very large, far exceeding the number of spectral channels collected in the ¯eld. Suppose an image pixel contains a mixture of p spectra from the library. Is it possible to uniquely identify these p spectra? We address this question in this paper and refer to it as the Large Spectral Library (LSL) problem. We show how to determine if unique identi¯cation is possible for any given library. We also show that if p is small compared to the number of spectral channels, it is very likely that unique identi¯cation is possible. We show that unique identi¯cation becomes less likely as p increases.

  5. Postdatism -- a perinatal problem?

    Science.gov (United States)

    Chhabra, S; Sood, S

    1990-01-01

    It has been traditionally accepted that maternal and fetal complications are at their lowest levels 37-42 weeks into gestation. 20% of pregnancies completed after 42 weeks gestation are thought to be affected by the postmaturity syndrome of uteroplacental insufficiency resulting in oligohydramnios, meconium passage, loss of fetal subcutaneous tissue, fetal asphyxia, and fetal death. Some workers, however, have also found that pregnancies completed between 40 and 42 weeks carry significant risk. The authors explored this question in a case-control study of 464 women seen at the Mahatma Gandhi Institute of Medical Sciences in Maharashtra, India. The cases of postdatism occurred in the absence of any other medical or obstetric problem. The operative delivery rate increased significantly among these patients compared to deliveries between 39 and 40 weeks. There was neither significant asphyxia nor perinatal loss in term completed normal patients. Asphyxia and perinatal mortality did, however, occur with postdatism. The authors note the likely role of oligohydramnios combined with placental dysfunction.

  6. Fibromyalgia and sexual problems.

    Science.gov (United States)

    Bazzichi, L; Giacomelli, C; Rossi, A; Sernissi, F; Scarpellini, P; Consensi, A; Bombardieri, S

    2012-09-28

    The aim of this review was to describe the recent literature concerning sexual dysfunction in fibromyalgic patients. To this end, we used the common online databases PubMed, MEDLINE and EMBASE (up to June 2012) and searched for the key words fibromyalgia (FM) and sexual dysfunction. All the studies examined underlined that FM is strictly associated with sexual dysfunction in women. The major findings observed were related to a decreased sexual desire and arousal, decreased experience of orgasm, and in some studies an increase in genital pain. The psychological aspects, together with the stress related to the constant presence of chronic widespread pain, fatigue and sleep disturbances, are certainly a major factor that adversely affects the sexuality of the patient with FM. Moreover, the drugs most commonly used in these cases may interfere negatively on the sexuality and sexual function of these patients. Therefore, the therapeutic intervention should be targeted and the side effects should be weighed up against the positive effects. It is of the utmost importance to recognise the problem of sexuality and sexual dysfunction in a more complex form of its expression and undertake a multidisciplinary therapeutic intervention to improve the quality of FM patients' life.

  7. Problem children or harassed childhood?

    DEFF Research Database (Denmark)

    Warming, Hanne

    instition as stressed andnoisy, and thus it is the children they try to change (re-socialize) to solve the problems. The paper concludes that the discoruses tend to individualize structural problems with the result that a large group of children are identified as problem children rather than given better...

  8. Parallel Symmetric Eigenvalue Problem Solvers

    Science.gov (United States)

    2015-05-01

    Plemmons G. Golub and A. Sameh. High-speed computing : scientific appli- cations and algorithm design. University of Illinois Press, Champaign, Illinois , 1988...16. SECURITY CLASSIFICATION OF: Sparse symmetric eigenvalue problems arise in many computational science and engineering applications such as...Eigenvalue Problem Solvers Report Title Sparse symmetric eigenvalue problems arise in many computational science and engineering applications such as

  9. Euler's Three-Body Problem.

    Science.gov (United States)

    Wild, Walter J.

    1980-01-01

    Discusses the simplest three-body problem, known as Euler's problem. The article, intended for students in the undergraduate mathematics and physics curricula, shows how the complex equations for a specific three-body problem can be solved on a small calculator. (HM)

  10. Solving complex fisheries management problems

    DEFF Research Database (Denmark)

    Petter Johnsen, Jahn; Eliasen, Søren Qvist

    2011-01-01

    A crucial issue for the new EU common fisheries policy is how to solve the discard problem. Through a study of the institutional set up and the arrangements for solving the discard problem in Denmark, the Faroe Islands, Iceland and Norway, the article identifies the discard problem as related...

  11. A rainbow inverse problem

    Directory of Open Access Journals (Sweden)

    Calvez V.

    2010-12-01

    Full Text Available We consider the radiative transfer equation (RTE with reflection in a three-dimensional domain, infinite in two dimensions, and prove an existence result. Then, we study the inverse problem of retrieving the optical parameters from boundary measurements, with help of existing results by Choulli and Stefanov. This theoretical analysis is the framework of an attempt to model the color of the skin. For this purpose, a code has been developed to solve the RTE and to study the sensitivity of the measurements made by biophysicists with respect to the physiological parameters responsible for the optical properties of this complex, multi-layered material. On étudie l’équation du transfert radiatif (ETR dans un domaine tridimensionnel infini dans deux directions, et on prouve un résultat d’existence. On s’intéresse ensuite à la reconstruction des paramètres optiques à partir de mesures faites au bord, en s’appuyant sur des résultats de Choulli et Stefanov. Cette analyse sert de cadre théorique à un travail de modélisation de la couleur de la peau. Dans cette perspective, un code à été développé pour résoudre l’ETR et étudier la sensibilité des mesures effectuées par les biophysiciens par rapport aux paramètres physiologiques tenus pour responsables des propriétés optiques de ce complexe matériau multicouche.

  12. Simon on Problem-Solving

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai

    as a general approach to problem solving. We apply these Simonian ideas to organizational issues, specifically new organizational forms. Specifically, Simonian ideas allow us to develop a morphology of new organizational forms and to point to some design problems that characterize these forms.Keywords: Herbert...... Simon, problem-solving, new organizational forms. JEL Code: D23, D83......Two of Herbert Simon's best-known papers are "The Architecture of Complexity" and "The Structure of Ill-Structured Problems." We discuss the neglected links between these two papers, highlighting the role of decomposition in the context of problems on which constraints have been imposed...

  13. A taxonomy of inductive problems.

    Science.gov (United States)

    Kemp, Charles; Jern, Alan

    2014-02-01

    Inductive inferences about objects, features, categories, and relations have been studied for many years, but there are few attempts to chart the range of inductive problems that humans are able to solve. We present a taxonomy of inductive problems that helps to clarify the relationships between familiar inductive problems such as generalization, categorization, and identification, and that introduces new inductive problems for psychological investigation. Our taxonomy is founded on the idea that semantic knowledge is organized into systems of objects, features, categories, and relations, and we attempt to characterize all of the inductive problems that can arise when these systems are partially observed. Recent studies have begun to address some of the new problems in our taxonomy, and future work should aim to develop unified theories of inductive reasoning that explain how people solve all of the problems in the taxonomy.

  14. Depression and social problem solving.

    Science.gov (United States)

    Marx, E M; Williams, J M; Claridge, G C

    1992-02-01

    Twenty depressed patients with major depressive disorder, 20 nondepressed matched control subjects, and 17 patients with anxiety disorders were compared in different measures of social problem solving. Problem solving was assessed with the Means-Ends Problem-Solving Test (Study 1), the solution of personal problems, and a problem-solving questionnaire (Study 2). Results showed that, as predicted, depressed subjects suffered from a deficit in problem solving in all three measures. The majority of these deficits were also displayed by the clinical control group rather than being specific to a diagnosis of depression. However, depressed subjects produced less effective solutions than did normal and clinical control subjects. The results suggest that depressed and anxious patients may have difficulties at different stages of the problem-solving process.

  15. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production...... costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra......) and may be defined in any number of dimensions. Solution methods are based on theory from both computational geometry and operations research. The scientific contributions of this thesis are presented in the form of six papers and a section which introduces the many problem types and recent solution...

  16. The Association between Attention Problems and Internalizing and Externalizing Problems: The Mediating Role of Peer Problems

    Science.gov (United States)

    Yip, Vania T.; Ang, Rebecca P.; Ooi, Yoon Phaik; Fung, Daniel S. S.; Mehrotra, Kala; Sung, Min; Lim, Choon Guan

    2013-01-01

    Background: The high prevalence of attention problems in children warrants concern, as it is a risk factor for internalizing and externalizing problems. There lies a need to understand possible factors that may mediate this link so that interventions may be targeted to alleviate these mediators and interrupt the link between attention problems and…

  17. What is a problem?: On problem-oriented interdisciplinarity.

    Science.gov (United States)

    Schmidt, Jan C

    2011-06-01

    Among others, the term "problem" plays a major role in the various attempts to characterize interdisciplinarity or transdisciplinarity, as used synonymously in this paper. Interdisciplinarity (ID) is regarded as "problem solving among science, technology and society" and as "problem orientation beyond disciplinary constraints" (cf. Frodeman et al.: The Oxford Handbook of Interdisciplinarity. Oxford University Press, Oxford, 2010). The point of departure of this paper is that the discourse and practice of ID have problems with the "problem". The objective here is to shed some light on the vague notion of "problem" in order to advocate a specific type of interdisciplinarity: problem-oriented interdisciplinarity. The outline is as follows: Taking an ex negativo approach, I will show what problem-oriented ID does not mean. Using references to well-established distinctions in philosophy of science, I will show three other types of ID that should not be placed under the umbrella term "problem-oriented ID": object-oriented ID ("ontology"), theory-oriented ID (epistemology), and method-oriented ID (methodology). Different philosophical thought traditions can be related to these distinguishable meanings. I will then clarify the notion of "problem" by looking at three systematic elements: an undesired (initial) state, a desired (goal) state, and the barriers in getting from the one to the other. These three elements include three related kinds of knowledge: systems, target, and transformation knowledge. This paper elaborates further methodological and epistemological elements of problem-oriented ID. It concludes by stressing that problem-oriented ID is the most needed as well as the most challenging type of ID.

  18. The problem of time and the problem of quantum measurement

    CERN Document Server

    Singh, Tejinder P

    2012-01-01

    Quantum theory depends on an external classical time, and there ought to exist an equivalent reformulation of the theory which does not depend on such a time. The demand for the existence of such a reformulation suggests that quantum theory is an approximation to a stochastic non-linear theory. The stochastic non-linearity provides a dynamical explanation for the collapse of the wave-function during a quantum measurement. Hence the problem of time and the measurement problem are related to each other: the search for a solution for the former problem naturally implies a solution for the latter problem.

  19. Mathematical problem solving by analogy.

    Science.gov (United States)

    Novick, L R; Holyoak, K J

    1991-05-01

    We report the results of 2 experiments and a verbal protocol study examining the component processes of solving mathematical word problems by analogy. College students first studied a problem and its solution, which provided a potential source for analogical transfer. Then they attempted to solve several analogous problems. For some problems, subjects received one of a variety of hints designed to reduce or eliminate the difficulty of some of the major processes hypothesized to be involved in analogical transfer. Our studies yielded 4 major findings. First, the process of mapping the features of the source and target problems and the process of adapting the source solution procedure for use in solving the target problem were clearly distinguished: (a) Successful mapping was found to be insufficient for successful transfer and (b) adaptation was found to be a major source of transfer difficulty. Second, we obtained direct evidence that schema induction is a natural consequence of analogical transfer. The schema was found to co-exist with the problems from which it was induced, and both the schema and the individual problems facilitated later transfer. Third, for our multiple-solution problems, the relation between analogical transfer and solution accuracy was mediated by the degree of time pressure exerted for the test problems. Finally, mathematical expertise was a significant predictor of analogical transfer, but general analogical reasoning ability was not. The implications of the results for models of analogical transfer and for instruction were considered.

  20. Problems of Small Debris

    Directory of Open Access Journals (Sweden)

    V. V. Zelentsov

    2015-01-01

    shell case design SC is very high. But if the particle can penetrate the shell, then the opposite side is possible breakaway material of construction and the resulting fragments can cause serious damage to equipment and communications satellites.Height SD placed unevenly. The maximum amount of it is concentrated in the most exploited heights: geostationary orbits, sun-synchronous orbit and low orbit. Fragments of SD "live" in OKP different times. At low altitudes (200 ... 400 km - from a few weeks to a year, on the sun-synchronous orbit for decades and geostationary hundreds of years.At present, the space-facing two problems: first how to protect spacecraft from damage to the small debris and clean as the second TFC from the existing SD there and take measures to eliminate clogging OKP new launches of spacecraft.

  1. Diabetes and Sexual and Urologic Problems

    Science.gov (United States)

    ... Disease, & Other Dental Problems Diabetes & Sexual & Urologic Problems Diabetes & Sexual & Urologic Problems Troublesome bladder symptoms and changes ... early onset of these sexual and urologic problems. Diabetes and Sexual Problems Both men and women with ...

  2. Abstract Cauchy problems three approaches

    CERN Document Server

    Melnikova, Irina V

    2001-01-01

    Although the theory of well-posed Cauchy problems is reasonably understood, ill-posed problems-involved in a numerous mathematical models in physics, engineering, and finance- can be approached in a variety of ways. Historically, there have been three major strategies for dealing with such problems: semigroup, abstract distribution, and regularization methods. Semigroup and distribution methods restore well-posedness, in a modern weak sense. Regularization methods provide approximate solutions to ill-posed problems. Although these approaches were extensively developed over the last decades by many researchers, nowhere could one find a comprehensive treatment of all three approaches.Abstract Cauchy Problems: Three Approaches provides an innovative, self-contained account of these methods and, furthermore, demonstrates and studies some of the profound connections between them. The authors discuss the application of different methods not only to the Cauchy problem that is not well-posed in the classical sense, b...

  3. Problem Solving and Complex Systems

    CERN Document Server

    Guinand, Frédéric

    2008-01-01

    The observation and modeling of natural Complex Systems (CSs) like the human nervous system, the evolution or the weather, allows the definition of special abilities and models reusable to solve other problems. For instance, Genetic Algorithms or Ant Colony Optimizations are inspired from natural CSs to solve optimization problems. This paper proposes the use of ant-based systems to solve various problems with a non assessing approach. This means that solutions to some problem are not evaluated. They appear as resultant structures from the activity of the system. Problems are modeled with graphs and such structures are observed directly on these graphs. Problems of Multiple Sequences Alignment and Natural Language Processing are addressed with this approach.

  4. Dimensions of problem based learning

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Andreasen, Lars Birch

    2013-01-01

    The article contributes to the literature on problem based learning and problem-oriented project work, building on and reflecting the experiences of the authors through decades of work with problem-oriented project pedagogy. The article explores different dimensions of problem based learning...... such as the exploration of problems, the project method, online collaboration, and the dialogic nature of students’ working together. A special attention is given to the historical development and theoretical roots of problem-oriented project work in Denmark. The case to be explored will be the Masters programme in ICT...... and Learning (MIL). We discuss changes in the roles of the teachers as supervisors within this learning environment, and we explore the involvement of students as active participants and co-designers of how course and project activities unfold....

  5. The underinvestment problem under conglomeration

    Directory of Open Access Journals (Sweden)

    Jacques A. Schnabel

    2015-12-01

    Full Text Available This theoretical paper explores whether the underinvestment problem is aggravated or ameliorated by the formation of a pure conglomerate. It establishes that the answer depends critically on the volatility of corporate assets. If volatility is low, conglomeration ameliorates the underinvestment problem, whereas if volatility is high, conglomeration aggravates the underinvestment problem. These analytical results are then invoked as a potential explanation for the ambiguous conclusions of empirical studies that delve into the existence of a conglomerate discount.

  6. Mathematical problems for chemistry students

    CERN Document Server

    Pota, Gyorgy

    2011-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistrystudents in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialistsof the chemistry-related fields (physicists, mathematicians, biologists, etc.) intothe world of the chemical applications.Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, others we

  7. Pet Problems at Home: Pet Problems in the Community.

    Science.gov (United States)

    Soltow, Willow

    1984-01-01

    Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

  8. Students' Images of Problem Contexts when Solving Applied Problems

    Science.gov (United States)

    Moore, Kevin C.; Carlson, Marilyn P.

    2012-01-01

    This article reports findings from an investigation of precalculus students' approaches to solving novel problems. We characterize the images that students constructed during their solution attempts and describe the degree to which they were successful in imagining how the quantities in a problem's context change together. Our analyses revealed…

  9. Problem posing reflections and applications

    CERN Document Server

    Brown, Stephen I

    2014-01-01

    As a result of the editors' collaborative teaching at Harvard in the late 1960s, they produced a ground-breaking work -- The Art Of Problem Posing -- which related problem posing strategies to the already popular activity of problem solving. It took the concept of problem posing and created strategies for engaging in that activity as a central theme in mathematics education. Based in part upon that work and also upon a number of articles by its authors, other members of the mathematics education community began to apply and expand upon their ideas. This collection of thirty readings is a tes

  10. Problem solving through recreational mathematics

    CERN Document Server

    Averbach, Bonnie

    1999-01-01

    Historically, many of the most important mathematical concepts arose from problems that were recreational in origin. This book takes advantage of that fact, using recreational mathematics - problems, puzzles and games - to teach students how to think critically. Encouraging active participation rather than just observation, the book focuses less on mathematical results than on how these results can be applied to thinking about problems and solving them. Each chapter contains a diverse array of problems in such areas as logic, number and graph theory, two-player games of strategy, solitaire ga

  11. 2008+ solved problems in electromagnetics

    CERN Document Server

    Nasar, Syed

    2007-01-01

    SciTech Publishing is reissuing this extremely valuable learning resource, originally published in 1992 in the Schaum's Problem-Solving Series for students of electromagnetics and those who wish to refresh and solidify their understanding of its challenging applications. Problem-solving drill helps develop confidence, but few textbooks offer the answers, never mind the complete solutions, to their chapter exercises. Here noted author Professor Syed Nasar has divided the book's problems into topic areas similar to a textbook and presented a wide array of problems, followed immediately by their

  12. Dynamics of Universe in Problems

    CERN Document Server

    Bolotin, Yu L; Ivashkevych, G I; Lemets, O A; Yerokhin, D A

    2009-01-01

    We do not know books of problems on cosmology including its recent achievements. However we believe that such a book would be extremely useful for the youth poured in the last decade into that one of the most actively developing field of science. We suggest to cosmological community to create a joint collaboration "Dynamics of Universe in Problems". Now we propose first 500 problems as our contribution into that beginning. If our project will make an interest then it is needed to think how to organize technically the international collaboration in that direction. In any case we plan to update our "database" monthly, including 30-50 new problems every time.

  13. Inverse problem in hydrogeology

    Science.gov (United States)

    Carrera, Jesús; Alcolea, Andrés; Medina, Agustín; Hidalgo, Juan; Slooten, Luit J.

    2005-03-01

    The state of the groundwater inverse problem is synthesized. Emphasis is placed on aquifer characterization, where modelers have to deal with conceptual model uncertainty (notably spatial and temporal variability), scale dependence, many types of unknown parameters (transmissivity, recharge, boundary conditions, etc.), nonlinearity, and often low sensitivity of state variables (typically heads and concentrations) to aquifer properties. Because of these difficulties, calibration cannot be separated from the modeling process, as it is sometimes done in other fields. Instead, it should be viewed as one step in the process of understanding aquifer behavior. In fact, it is shown that actual parameter estimation methods do not differ from each other in the essence, though they may differ in the computational details. It is argued that there is ample room for improvement in groundwater inversion: development of user-friendly codes, accommodation of variability through geostatistics, incorporation of geological information and different types of data (temperature, occurrence and concentration of isotopes, age, etc.), proper accounting of uncertainty, etc. Despite this, even with existing codes, automatic calibration facilitates enormously the task of modeling. Therefore, it is contended that its use should become standard practice. L'état du problème inverse des eaux souterraines est synthétisé. L'accent est placé sur la caractérisation de l'aquifère, où les modélisateurs doivent jouer avec l'incertitude des modèles conceptuels (notamment la variabilité spatiale et temporelle), les facteurs d'échelle, plusieurs inconnues sur différents paramètres (transmissivité, recharge, conditions aux limites, etc.), la non linéarité, et souvent la sensibilité de plusieurs variables d'état (charges hydrauliques, concentrations) des propriétés de l'aquifère. A cause de ces difficultés, le calibrage ne peut êtreséparé du processus de modélisation, comme c'est le

  14. A Problem with Current Conceptions of Expert Problem Solving

    CERN Document Server

    Kuo, Eric; Gupta, Ayush; Elby, Andrew

    2011-01-01

    Current conceptions of expert problem solving depict physical/conceptual reasoning and formal mathematical reasoning as separate steps: a good problem solver first translates a physical understanding into mathematics, then performs mathematical/symbolic manipulations, then interprets the mathematical solution physically. However, other research suggests that blending conceptual and symbolic reasoning during symbolic manipulations can reflect expertise. We explore the hypothesis that blending conceptual and symbolic reasoning (i) indicates problem-solving expertise more than adherence to "expert" problem-solving steps and (ii) is something some undergraduates do spontaneously, suggesting it's a feasible instructional target. Interviewed students were asked to (1) explain a particular equation and (2) solve a problem using that equation. In-depth analysis of two students, Alex and Pat, revealed a pattern of behavior. All 11 interviews were coded to investigate the generalizability of this pattern. Alex describe...

  15. Good Boys Are Problems Too!

    Science.gov (United States)

    Warren, Simon

    2003-01-01

    The "problem" of boys' achievement in the United Kingdom has emerged as part of a policy response to a crisis in the post-war social settlement. Post-Fordism has become the dominant meta-policy of education reform in the United Kingdom, constituting both policy problems and solutions as gender-neutral. However, the economic and political…

  16. Subspace Methods for Eigenvalue Problems

    NARCIS (Netherlands)

    Hochstenbach, Michiel Erik

    2003-01-01

    This thesis treats a number of aspects of subspace methods for various eigenvalue problems. Vibrations and their corresponding eigenvalues (or frequencies) arise in science, engineering, and daily life. Matrix eigenvalue problems come from a large number of areas, such as chemistry, mechanics, dyn

  17. Problem-Oriented Project Work

    DEFF Research Database (Denmark)

    Olsen, Poul Bitsch; Pedersen, Nils Kaare

    This book is meant to support problem-oriented learning activities. Problem-orientation concerns the reasoning about lack of knowledge, while project work includes the ethnomethods that are practiced when collectives produce scientific knowledge. This book reflects particular methods related...

  18. Do TEFL Articles Solve Problems?

    Science.gov (United States)

    Edge, Julian

    1985-01-01

    Discusses the problem which English-as-a-foreign-language (EFL) teacher trainees who are nonnative English speakers have in reading articles about EFL teaching methods. As a solution to this problem, the author produced a worksheet for the students to fill in while reading the articles which followed Hoey's…

  19. Sinopec Tests Find No Problems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Sinopec gas defended the quality of its liquefied petroleum gas(LPG)by announcing the results of independent tests in early February,following allegations by drivers that their vehicles had problems after filling their tanks at Sinopec petrol stations.Its first media briefing over the suspected engine-stalling problem of its product,Sinopec(Hong Kong)Petrol Filling Station Co.

  20. Some Results behind Dividend Problems

    Institute of Scientific and Technical Information of China (English)

    Ming Zhou; Li Wei; Jun-yi Guo

    2006-01-01

    We consider the basic dividend problem of the compound Poisson model with constant barrier strategy. Some results concealed behind the dividend problem are made explicit in the present work. Different methods and some of which are firstly given in this paper. All these results presented certain direct relationship between some important actuary variables in classical risk theory is also revealed.

  1. Vibrations and Stability: Solved Problems

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    Worked out solutions for exercise problems in J. J. Thomsen 'Vibrations and Stability: Advanced Theory, Analysis, and Tools', Springer, Berlin - Heidelberg, 2003.......Worked out solutions for exercise problems in J. J. Thomsen 'Vibrations and Stability: Advanced Theory, Analysis, and Tools', Springer, Berlin - Heidelberg, 2003....

  2. "Find-the-Flaw" Problems

    Science.gov (United States)

    Styer, Daniel F.

    2011-01-01

    A physics teacher assigns problems to his or her students not to keep them indoors during sunny days, but to strengthen and deepen their understanding of the universe. Every problem has not only an answer, but also a "moral to the story"--a reason why that question and that answer are interesting and probing. It is an unfortunate fact that our…

  3. Students' Problem Solving and Justification

    Science.gov (United States)

    Glass, Barbara; Maher, Carolyn A.

    2004-01-01

    This paper reports on methods of students' justifications of their solution to a problem in the area of combinatorics. From the analysis of the problem solving of 150 students in a variety of settings from high-school to graduate study, four major forms of reasoning evolved: (1) Justification by Cases, (2) Inductive Argument, (3) Elimination…

  4. Combinatorial reasoning to solve problems

    NARCIS (Netherlands)

    Coenen, Tom; Hof, Frits; Verhoef, Nellie

    2016-01-01

    This study reports combinatorial reasoning to solve problems. We observed the mathematical thinking of students aged 14-16. We study the variation of the students’ solution strategies in the context of emergent modelling. The results show that the students are tempted to begin the problem solving pr

  5. Promote Problem-Solving Discourse

    Science.gov (United States)

    Bostic, Jonathan; Jacobbe, Tim

    2010-01-01

    Fourteen fifth-grade students gather at the front of the classroom as their summer school instructor introduces Jonathan Bostic as the mathematics teacher for the week. Before examining any math problems, Bostic sits at eye level with the students and informs them that they will solve problems over the next four days by working individually as…

  6. Solving the drift control problem

    Directory of Open Access Journals (Sweden)

    Melda Ormeci Matoglu

    2015-12-01

    Full Text Available We model the problem of managing capacity in a build-to-order environment as a Brownian drift control problem. We formulate a structured linear program that models a practical discretization of the problem and exploit a strong relationship between relative value functions and dual solutions to develop a functional lower bound for the continuous problem from a dual solution to the discrete problem. Refining the discretization proves a functional strong duality for the continuous problem. The linear programming formulation is so badly scaled, however, that solving it is beyond the capabilities of standard solvers. By demonstrating the equivalence between strongly feasible bases and deterministic unichain policies, we combinatorialize the pivoting process and by exploiting the relationship between dual solutions and relative value functions, develop a mechanism for solving the LP without ever computing its coefficients. Finally, we exploit the relationship between relative value functions and dual solutions to develop a scheme analogous to column generation for refining the discretization so as to drive the gap between the discrete approximation and the continuous problem to zero quickly while keeping the LP small. Computational studies show our scheme is much faster than simply solving a regular discretization of the problem both in terms of finding a policy with a low average cost and in terms of providing a lower bound on the optimal average cost.

  7. Geothermal Energy: Prospects and Problems

    Science.gov (United States)

    Ritter, William W.

    1973-01-01

    An examination of geothermal energy as a means of increasing the United States power resources with minimal pollution problems. Developed and planned geothermal-electric power installations around the world, capacities, installation dates, etc., are reviewed. Environmental impact, problems, etc. are discussed. (LK)

  8. Analysis of a Pendulum Problem

    DEFF Research Database (Denmark)

    Jantzen, Jan

    1998-01-01

    The ball-balancer, or cart-ball system, demonstrates some basic concepts in control being nonlinear, multivariable, and non-minimum phase. It is basically an inverted pendulum problem, which is a much used benchmark problem. The objective here is to provide an analysis of the system, which can...

  9. Non-Euclidean Visibility Problems

    Indian Academy of Sciences (India)

    Fernando Chamizo

    2006-05-01

    We consider the analog of visibility problems in hyperbolic plane (represented by Poincaré half-plane model $\\mathbb{H}$), replacing the standard lattice $\\mathbb{Z} × \\mathbb{Z}$ by the orbit = under the full modular group $SL_2(\\mathbb{Z})$. We prove a visibility criterion and study orchard problem and the cardinality of visible points in large circles.

  10. "What Works" with Problem Learners.

    Science.gov (United States)

    Swanson, Elizabeth F.; Halley, Mari Kirsch

    1986-01-01

    Describes the use of a structured, problem-solving dialog among teachers and between teacher and student to review successes in solving the instructional problems of a particular child and to develop an effective education plan which fosters student responsibility for learning and behavior. Uses a case study to illustrate the "What Works" process.…

  11. Problems diagnosis in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Leugner, L.

    1986-10-01

    Diagnosis of engine problems in diesel engines used in Western Canadian coal mines is discussed. Areas to which attention must be paid include the air cleaners, turbocharger, engine compression and the fuel system. Exhaust smoke should be analysed to help diagnose combustion related problems.

  12. The problem of compatible representatives

    CERN Document Server

    Knuth, Donald E

    2008-01-01

    The purpose of this note is to attach a name to a natural class of combinatorial problems and to point out that this class includes many important special cases. We also show that a simple problem of placing nonoverlapping labels on a rectangular map is NP-complete.

  13. Teaching Employees to Solve Problems.

    Science.gov (United States)

    Miller, Lauren E.; Feggestad, Kurt

    1987-01-01

    John Deere's systematic problem-solving training for its employees is applicable in the vocational classroom. The process includes stating the problem, writing its specifications, identifying distinctions, determining changes that occurred at the time, identifying possible causes, testing the possibilities, verifying the most probable cause, and…

  14. Math word problems for dummies

    CERN Document Server

    Sterling, Mary Jane

    2008-01-01

    Covers percentages, probability, proportions, and moreGet a grip on all types of word problems by applying them to real lifeAre you mystified by math word problems? This easy-to-understand guide shows you how to conquer these tricky questions with a step-by-step plan for finding the right solution each and every time, no matter the kind or level of problem. From learning math lingo and performing operations to calculating formulas and writing equations, you''ll get all the skills you need to succeed!Discover how to: * Translate word problems into plain English* Brush up on basic math skills* Plug in the right operation or formula* Tackle algebraic and geometric problems* Check your answers to see if they work

  15. Multiscale Modelling and Inverse Problems

    CERN Document Server

    Nolen, J; Stuart, A M

    2010-01-01

    The need to blend observational data and mathematical models arises in many applications and leads naturally to inverse problems. Parameters appearing in the model, such as constitutive tensors, initial conditions, boundary conditions, and forcing can be estimated on the basis of observed data. The resulting inverse problems are often ill-posed and some form of regularization is required. These notes discuss parameter estimation in situations where the unknown parameters vary across multiple scales. We illustrate the main ideas using a simple model for groundwater flow. We will highlight various approaches to regularization for inverse problems, including Tikhonov and Bayesian methods. We illustrate three ideas that arise when considering inverse problems in the multiscale context. The first idea is that the choice of space or set in which to seek the solution to the inverse problem is intimately related to whether a homogenized or full multiscale solution is required. This is a choice of regularization. The ...

  16. Scalable algorithms for contact problems

    CERN Document Server

    Dostál, Zdeněk; Sadowská, Marie; Vondrák, Vít

    2016-01-01

    This book presents a comprehensive and self-contained treatment of the authors’ newly developed scalable algorithms for the solutions of multibody contact problems of linear elasticity. The brand new feature of these algorithms is theoretically supported numerical scalability and parallel scalability demonstrated on problems discretized by billions of degrees of freedom. The theory supports solving multibody frictionless contact problems, contact problems with possibly orthotropic Tresca’s friction, and transient contact problems. It covers BEM discretization, jumping coefficients, floating bodies, mortar non-penetration conditions, etc. The exposition is divided into four parts, the first of which reviews appropriate facets of linear algebra, optimization, and analysis. The most important algorithms and optimality results are presented in the third part of the volume. The presentation is complete, including continuous formulation, discretization, decomposition, optimality results, and numerical experimen...

  17. Methods of solving nonstandard problems

    CERN Document Server

    Grigorieva, Ellina

    2015-01-01

    This book, written by an accomplished female mathematician, is the second to explore nonstandard mathematical problems – those that are not directly solved by standard mathematical methods but instead rely on insight and the synthesis of a variety of mathematical ideas.   It promotes mental activity as well as greater mathematical skills, and is an ideal resource for successful preparation for the mathematics Olympiad. Numerous strategies and techniques are presented that can be used to solve intriguing and challenging problems of the type often found in competitions.  The author uses a friendly, non-intimidating approach to emphasize connections between different fields of mathematics and often proposes several different ways to attack the same problem.  Topics covered include functions and their properties, polynomials, trigonometric and transcendental equations and inequalities, optimization, differential equations, nonlinear systems, and word problems.   Over 360 problems are included with hints, ...

  18. Bacteriological problems in water supply systems; Bakteriologische Probleme bei Wassersystemen

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, P.

    2007-07-01

    This article takes a look at bacteriological problems in hot-water distribution system and, in particular looks at the situation concerning legionella bacteria which thrive in standing water at temperatures often encountered in domestic hot water systems. The article is based on experience gained in the analysis of over 1500 hot-water systems. Diseases caused by the inhalation of water droplets emanating from domestic hot-water systems are discussed and showers are mentioned as being a problem zone. An ecological thermal protective system is described. Problems that can be encountered in ventilation and air-conditioning systems and other potential sources are also mentioned.

  19. Spreadsheet modelling for solving combinatorial problems: The vendor selection problem

    CERN Document Server

    Ipsilandis, Pandelis G

    2008-01-01

    Spreadsheets have grown up and became very powerful and easy to use tools in applying analytical techniques for solving business problems. Operations managers, production managers, planners and schedulers can work with them in developing solid and practical Do-It-Yourself Decision Support Systems. Small and Medium size organizations, can apply OR methodologies without the presence of specialized software and trained personnel, which in many cases cannot afford anyway. This paper examines an efficient approach in solving combinatorial programming problems with the use of spreadsheets. A practical application, which demonstrates the approach, concerns the development of a spreadsheet-based DSS for the Multi Item Procurement Problem with Fixed Vendor Cost. The DSS has been build using exclusively standard spreadsheet feature and can solve real problems of substantial size. The benefits and limitations of the approach are also discussed.

  20. Problem solving stages in the five square problem.

    Science.gov (United States)

    Fedor, Anna; Szathmáry, Eörs; Öllinger, Michael

    2015-01-01

    According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight, and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviorally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. Our participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and some of them also had the possibility of reporting impasse while working on the task. We found that the majority of participants did not follow the classic four-stage model of insight, but had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model is not sufficient to describe variability on the individual level. We revised the classic model and we provide a new model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviorally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behavior to verify insight theory.

  1. Optimization and geophysical inverse problems

    Energy Technology Data Exchange (ETDEWEB)

    Barhen, J.; Berryman, J.G.; Borcea, L.; Dennis, J.; de Groot-Hedlin, C.; Gilbert, F.; Gill, P.; Heinkenschloss, M.; Johnson, L.; McEvilly, T.; More, J.; Newman, G.; Oldenburg, D.; Parker, P.; Porto, B.; Sen, M.; Torczon, V.; Vasco, D.; Woodward, N.B.

    2000-10-01

    A fundamental part of geophysics is to make inferences about the interior of the earth on the basis of data collected at or near the surface of the earth. In almost all cases these measured data are only indirectly related to the properties of the earth that are of interest, so an inverse problem must be solved in order to obtain estimates of the physical properties within the earth. In February of 1999 the U.S. Department of Energy sponsored a workshop that was intended to examine the methods currently being used to solve geophysical inverse problems and to consider what new approaches should be explored in the future. The interdisciplinary area between inverse problems in geophysics and optimization methods in mathematics was specifically targeted as one where an interchange of ideas was likely to be fruitful. Thus about half of the participants were actively involved in solving geophysical inverse problems and about half were actively involved in research on general optimization methods. This report presents some of the topics that were explored at the workshop and the conclusions that were reached. In general, the objective of a geophysical inverse problem is to find an earth model, described by a set of physical parameters, that is consistent with the observational data. It is usually assumed that the forward problem, that of calculating simulated data for an earth model, is well enough understood so that reasonably accurate synthetic data can be generated for an arbitrary model. The inverse problem is then posed as an optimization problem, where the function to be optimized is variously called the objective function, misfit function, or fitness function. The objective function is typically some measure of the difference between observational data and synthetic data calculated for a trial model. However, because of incomplete and inaccurate data, the objective function often incorporates some additional form of regularization, such as a measure of smoothness

  2. Boundary stabilization of transmission problems

    Science.gov (United States)

    Cardoso, Fernando; Vodev, Georgi

    2010-02-01

    We study the transmission problem in bounded domains with dissipative boundary conditions. Under some natural assumptions, we prove uniform bounds of the corresponding resolvents on the real axis at high frequency and, as a consequence, we obtain regions free of eigenvalue. To this end, we extend the result of Cardoso et al. ["Distribution of resonances and local energy decay in the transmission problem. II," Math. Res. Lett. 6, 377 (1999)] under more general assumptions. As an application, we get exponential decay of the energy of the solutions of the corresponding mixed boundary value problems.

  3. Fractional Moments on Bandit Problems

    CERN Document Server

    B, Ananda Narayanan

    2012-01-01

    Reinforcement learning addresses the dilemma between exploration to find profitable actions and exploitation to act according to the best observations already made. Bandit problems are one such class of problems in stateless environments that represent this explore/exploit situation. We propose a learning algorithm for bandit problems based on fractional expectation of rewards acquired. The algorithm is theoretically shown to converge on an eta-optimal arm and achieve O(n) sample complexity. Experimental results show the algorithm incurs substantially lower regrets than parameter-optimized eta-greedy and SoftMax approaches and other low sample complexity state-of-the-art techniques.

  4. Problem Based Learning and sustainability

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Løkke, Søren; Schmidt, Jannick Højrup

    Problem-Based Learning (PBL) is a style of active learning based on problem solving. PBL aims at providing university students with flexible knowledge, capacity to self-learning, and skills in problem solving and collaboration. In this context, the present study explores the advantages...... University (AAU), Denmark, and focuses on the teaching of Life Cycle Assessment as a method for sustainability assessment. The objective is providing recommendations for future LCA teaching and learning. PBL activites performed at AAU were evaluated critically to detemine to what extent they addressed...

  5. The Soccer-Ball Problem

    Science.gov (United States)

    Hossenfelder, Sabine

    2014-07-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

  6. The Soccer-ball Problem

    CERN Document Server

    Hossenfelder, S

    2014-01-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. Motivated by Loop Quantum Gravity, this modified Lorentz-symmetry is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the "soccer-ball problem." This article briefly reviews the problem and the status of existing solution attempts.

  7. Problems in nonlinear resistive MHD

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, A.D.; Strait, E.J.; La Haye, R.J.; Chu, M.S.; Miller, R.L. [General Atomics, San Diego, CA (United States)

    1998-12-31

    Two experimentally relevant problems can relatively easily be tackled by nonlinear MHD codes. Both problems require plasma rotation in addition to the nonlinear mode coupling and full geometry already incorporated into the codes, but no additional physics seems to be crucial. These problems discussed here are: (1) nonlinear coupling and interaction of multiple MHD modes near the B limit and (2) nonlinear coupling of the m/n = 1/1 sawtooth mode with higher n gongs and development of seed islands outside q = 1.

  8. [Ethical problems in organ transplantation].

    Science.gov (United States)

    Valenta, J; Treska, V; Hasman, D

    1999-02-01

    Organ transplantation is an accepted therapeutic method with good results, but it is connected with many not only medical but also ethical problems. One of the most important problems is the donor programme. In cadaverous donors the main ethical and legal question is the decision who can issue the consent with organ retrieval; in living donors it is the problem of motivation and financial compensation. Allocation of organs with low compatibility or from non-ideal donors, and the recipient's consent in these cases may involve difficult decisions.

  9. Ruin problems and tail asymptotics

    DEFF Research Database (Denmark)

    Rønn-Nielsen, Anders

    The thesis Ruin Problems and Tail Asymptotics provides results on ruin problems for several classes of Markov processes. For a class of diffusion processes with jumps an explicit expression for the joint Laplace transform of the first passage time and the corresponding undershoot is derived...... by an underlying Harris recurrent Markov process some asymptotic results for the ruin probability are derived. Finally, a paper, which is separate in content from the rest of the thesis, treats a RESTART problem in the situation, where failures occur with decreasing intensity....

  10. Problems of multiphase fluid filtration

    CERN Document Server

    Konovalov, AN

    1994-01-01

    This book deals with a spectrum of problems related to the mathematical modeling of multiphase filtration. Emphasis is placed on an inseparable triad: model - algorithm - computer code. An analysis of new and traditional filtration problems from the point of view of both their numerical implementation and the reproduction of one or another technological characteristics of the processes under consideration is given. The basic principles which underlie the construction of efficient numerical methods taking into account the filtration problems are discussed: non-evolutionary nature, degeneration,

  11. COPD and other health problems

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000701.htm COPD and other health problems To use the sharing ... diabetes, and high blood pressure. Staying Healthy With COPD Work closely with your doctor to keep COPD ...

  12. Problems in Recording the Electrocardiogram.

    Science.gov (United States)

    Webster, John G.

    The unwanted signals that arise in electrocardiography are discussed. A technical background of electrocardiography is given, along with teaching techniques that educate students of medical instrumentation to solve the problems caused by these signals. (MJH)

  13. Eldercare at Home: Dental Problems

    Science.gov (United States)

    ... by brushing and flossing the teeth. An electric toothbrush may be easier for the person to use, ... older person is having problems using a regular toothbrush, an electric toothbrush may be easier to use. ...

  14. Eldercare at Home: Skin Problems

    Science.gov (United States)

    ... disorders that give rise to serious medical problems. Older skin is less oily, less elastic, and thinner. It ... of old age." Response Yes, it is true older skin is less oily and it is thinner than ...

  15. Corrosion Problems in Absorption Chillers

    Science.gov (United States)

    Stetson, Bruce

    1978-01-01

    Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

  16. Uncapacitated facility location problems: contributions

    Directory of Open Access Journals (Sweden)

    Galvão Roberto Diéguez

    2004-01-01

    Full Text Available The objective of the present paper is to review my personal contributions in the field of uncapacitated facility location problems. These contributions took place throughout my academic career, from the time I was a Ph.D. student at Imperial College to the present day. They cover approximately 30 years, from 1973 to 2003; they address: algorithms developed for the p-median problem and for a general formulation of uncapacitated location problems; the study of dynamic location models; covering and hierarchical location problems; queuing-based probabilistic location models. The contributions encompass theoretical developments, computational algorithms and practical applications. All work took place in an academic environment, with the invaluable collaboration of colleagues (both in Brazil and abroad and research students at COPPE. Each section in the paper is dedicated to a topic that involves a personal contribution. Every one of them is placed within the context of the existing literature.

  17. Multiple Solutions Involving Geoboard Problems.

    Science.gov (United States)

    Smith, Lyle R.

    1993-01-01

    Illustrates various methods to determine the perimeter and area of triangles and polygons formed on the geoboard. Methods utilize algebraic techniques, trigonometry, geometric theorems, and analytic geometry to solve problems and connect a variety of mathematical concepts. (MDH)

  18. Special Medical Problems of Athletes.

    Science.gov (United States)

    Couch, Joan M.

    1987-01-01

    This article addresses the situations in which athletes with special needs and considerations participate in sports. The health problems discussed are diabetes mellitus, exercise-induced asthma, exercise-induced anaphylaxis, and epilepsy. (MT)

  19. Solving a problem by analogy

    Science.gov (United States)

    Easton, Don

    1999-03-01

    This note is a description of a student solution to a problem. I found the solution exciting because it exemplifies the kind of solution by analogy that Feynman describes in The Feynman Lectures on Physics.

  20. Parameter estimation and inverse problems

    CERN Document Server

    Aster, Richard C; Thurber, Clifford H

    2005-01-01

    Parameter Estimation and Inverse Problems primarily serves as a textbook for advanced undergraduate and introductory graduate courses. Class notes have been developed and reside on the World Wide Web for faciliting use and feedback by teaching colleagues. The authors'' treatment promotes an understanding of fundamental and practical issus associated with parameter fitting and inverse problems including basic theory of inverse problems, statistical issues, computational issues, and an understanding of how to analyze the success and limitations of solutions to these probles. The text is also a practical resource for general students and professional researchers, where techniques and concepts can be readily picked up on a chapter-by-chapter basis.Parameter Estimation and Inverse Problems is structured around a course at New Mexico Tech and is designed to be accessible to typical graduate students in the physical sciences who may not have an extensive mathematical background. It is accompanied by a Web site that...

  1. The Mind-Body Problem.

    Science.gov (United States)

    Fodor, Jerry A.

    1981-01-01

    Describes several different philosophies of mind with each philosophy's explanation of the mind-body problem. Philosophies discussed include dualism, materialism, functionalism, radical behaviorism, logical behaviorism and central-state identity. (DS)

  2. Enteral nutrition - child - managing problems

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000164.htm Enteral nutrition - child - managing problems To use the sharing features ... trouble breathing, call 911. References Mcclave SA. Enteral nutrition. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  3. Progressive problems higher grade physics

    CERN Document Server

    Kennedy, William

    2001-01-01

    This book fully covers all three Units studied in Scotland's Higher Grade Physics course, providing a systematic array of problems (from the simplest to the most difficult) to lead variously abled pupils to examination success.

  4. Medical Tests for Prostate Problems

    Science.gov (United States)

    ... frequency—urination eight or more times a day urinary urgency—the inability to delay urination urinary incontinence—the ... prostatitis and another with BPH may both experience urinary urgency. Sometimes symptoms for the same prostate problem differ ...

  5. Statistical perspectives on inverse problems

    DEFF Research Database (Denmark)

    Andersen, Kim Emil

    of the interior of an object from electrical boundary measurements. One part of this thesis concerns statistical approaches for solving, possibly non-linear, inverse problems. Thus inverse problems are recasted in a form suitable for statistical inference. In particular, a Bayesian approach for regularisation...... is obtained by assuming that the a priori beliefs about the solution before having observed any data can be described by a prior distribution. The solution to the statistical inverse problem is then given by the posterior distribution obtained by Bayes' formula. Hence the solution of an ill-posed inverse...... problem is given in terms of probability distributions. Posterior inference is obtained by Markov chain Monte Carlo methods and new, powerful simulation techniques based on e.g. coupled Markov chains and simulated tempering is developed to improve the computational efficiency of the overall simulation...

  6. On Generalized Vector Equilibrium Problems

    Institute of Scientific and Technical Information of China (English)

    An-hua Wan; Jun-yi Fu; Wei-hua Mao

    2006-01-01

    A new generalized vector equilibrium problem involving set-valued mappings and the proper quasi-concavity of set-valued mappings in topological vector spaces are introduced; its existence theorems and the convexity of the solution sets are established.

  7. Solutions of fractional diffusion problems

    Directory of Open Access Journals (Sweden)

    Rabha W. Ibrahim

    2010-10-01

    Full Text Available Using the concept of majorant functions, we prove the existence and uniqueness of holomorphic solutions to nonlinear fractional diffusion problems. The analytic continuation of these solutions is studied and the singularity for two cases are posed.

  8. The three-body problem

    CERN Document Server

    Musielak, Z E

    2015-01-01

    The three-body problem, which describes three masses interacting through Newtonian gravity without any restrictions imposed on the initial positions and velocities of these masses, has attracted the attention of many scientists for more than 300 years. In this paper, we present a review of the three-body problem in the context of both historical and modern developments. We describe the general and restricted (circular and elliptic) three-body problems, different analytical and numerical methods of finding solutions, methods for performing stability analysis, search for periodic orbits and resonances, and application of the results to some interesting astronomical and space dynamical settings. We also provide a brief presentation of the general and restricted relativistic three-body problems, and discuss their astronomical applications.

  9. Problem Solving with General Semantics.

    Science.gov (United States)

    Hewson, David

    1996-01-01

    Discusses how to use general semantics formulations to improve problem solving at home or at work--methods come from the areas of artificial intelligence/computer science, engineering, operations research, and psychology. (PA)

  10. Surrogate Guderley Test Problem Definition

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory

    2012-07-06

    The surrogate Guderley problem (SGP) is a 'spherical shock tube' (or 'spherical driven implosion') designed to ease the notoriously subtle initialization of the true Guderley problem, while still maintaining a high degree of fidelity. In this problem (similar to the Guderley problem), an infinitely strong shock wave forms and converges in one-dimensional (1D) cylindrical or spherical symmetry through a polytropic gas with arbitrary adiabatic index {gamma}, uniform density {rho}{sub 0}, zero velocity, and negligible pre-shock pressure and specific internal energy (SIE). This shock proceeds to focus on the point or axis of symmetry at r = 0 (resulting in ostensibly infinite pressure, velocity, etc.) and reflect back out into the incoming perturbed gas.

  11. On Constrained Facility Location Problems

    Institute of Scientific and Technical Information of China (English)

    Wei-Lin Li; Peng Zhang; Da-Ming Zhu

    2008-01-01

    Given m facilities each with an opening cost, n demands, and distance between every demand and facility,the Facility Location problem finds a solution which opens some facilities to connect every demand to an opened facility such that the total cost of the solution is minimized. The k-Facility Location problem further requires that the number of opened facilities is at most k, where k is a parameter given in the instance of the problem. We consider the Facility Location problems satisfying that for every demand the ratio of the longest distance to facilities and the shortest distance to facilities is at most w, where w is a predefined constant. Using the local search approach with scaling technique and error control technique, for any arbitrarily small constant ∈ > 0, we give a polynomial-time approximation algorithm for the ω-constrained Facility Location problem with approximation ratio 1 + √ω + 1 + ∈, which significantly improves the previous best known ratio (ω + 1)/α for some 1 ≤α≤ 2, and a polynomial-time approximation algorithm for the ω-constrained κ-Facility Location problem with approximation ratio ω + 1 + ∈. On the aspect of approximation hardness, we prove that unless NP (C) DTIME(nO(loglogn)), the ω-constrained Facility Location problem cannot be approximated within 1 + √ω-1,which slightly improves the previous best known hardness result 1.243 + 0.316 ln(ω - 1). The experimental results on the standard test instances of Facility Location problem show that our algorithm also has good performance in practice.

  12. Solving Optimal Timing Problems Elegantly

    OpenAIRE

    Todorova, Tamara

    2013-01-01

    Few textbooks in mathematical economics cover optimal timing problems. Those which cover them do it scantly or in a rather clumsy way, making it hard for students to understand and apply the concept of optimal time in new contexts. Discussing the plentiful illustrations of optimal timing problems, we present an elegant and simple method of solving them. Whether the present value function is exponential or logarithmic, a convenient way to solve it is to convert the base to the exponential numb...

  13. COUNTERFEIT DRUGS: PROBLEMS AND SOLUTIONS

    OpenAIRE

    Khanna Surabhi; Nasa Atul; Garg Arun

    2010-01-01

    The pharmaceutical industry is under extraordinary strain. Facing the wrath of consumers because of the cost of products, constantly answering the questions of state and federal legislators looking to control health care costs, and losing value in the marketplace, the industry’s hands are more than full. A less discussed but substantial problem impacts all of pharmaceutical industry’s other problems, counterfeiting. The World Health Organization estimates that counterfeit drugs make up about ...

  14. How to Deal With Problems

    Institute of Scientific and Technical Information of China (English)

    颜寒箫

    2012-01-01

    The real price of Sept 11 for America is the economic decline. The reason is that America didn't deal well with the terrorists. So, Bush tax cuts and the deficit-financed wars in Iraq and Afghanistan made America heavily in debt. If America hadn't caused war in Iraq and Afghan in order to sol;ee the terrorist problem, things might be different now. That makes me think deeply how we should deal with problems.

  15. Triage of the Sign Problem

    CERN Document Server

    Splittorff, K

    2007-01-01

    We discuss the sign problem in QCD at nonzero chemical potential and its relation with chiral symmetry breaking and the spectrum of the Dirac operator using the framework of chiral random matrix theory. We show that the Banks-Casher formula is not valid for theories with a sign problem and has to be replaced by an alternative mechanism that is worked out in detail for QCD in one dimension at nonzero chemical potential.

  16. [Problems of bilinguism in psychotherapy].

    Science.gov (United States)

    Fadda, S; Müller, C

    1978-01-01

    The authors have attempted an introductory study of problems which are inherent to psychoanalytically oriented psychotherapy and psychoanalysis conducted in the second language of a bilingual therapist. This situation seems to be more complex than is usually admitted in current literature. The main problem encountered by the authors in their personal practice stems from the fact that the process of identification becomes complex when the therapist is confronted with regressive and/or progressive shifts in the course of the treatment.

  17. The Consistent Vehicle Routing Problem

    Energy Technology Data Exchange (ETDEWEB)

    Groer, Christopher S [ORNL; Golden, Bruce [University of Maryland; Edward, Wasil [American University

    2009-01-01

    In the small package shipping industry (as in other industries), companies try to differentiate themselves by providing high levels of customer service. This can be accomplished in several ways, including online tracking of packages, ensuring on-time delivery, and offering residential pickups. Some companies want their drivers to develop relationships with customers on a route and have the same drivers visit the same customers at roughly the same time on each day that the customers need service. These service requirements, together with traditional constraints on vehicle capacity and route length, define a variant of the classical capacitated vehicle routing problem, which we call the consistent VRP (ConVRP). In this paper, we formulate the problem as a mixed-integer program and develop an algorithm to solve the ConVRP that is based on the record-to-record travel algorithm. We compare the performance of our algorithm to the optimal mixed-integer program solutions for a set of small problems and then apply our algorithm to five simulated data sets with 1,000 customers and a real-world data set with more than 3,700 customers. We provide a technique for generating ConVRP benchmark problems from vehicle routing problem instances given in the literature and provide our solutions to these instances. The solutions produced by our algorithm on all problems do a very good job of meeting customer service objectives with routes that have a low total travel time.

  18. Stump problems in traumatic amputation.

    Science.gov (United States)

    Hirai, M; Tokuhiro, A; Takechi, H

    1993-12-01

    Stump problems in amputations resulting from employment related injuries were investigated in 397 cases in the Chugoku and Shikoku districts of Japan between 1987 and 1991. Ninety-seven patients (24%) had stump problems which interfered the prosthetic fitting. Stump problems of the upper extremity were seen in about 9% (17 amputees), two thirds of which were skin troubles. Stump problems of the lower extremity were seen in about 37% (80 amputees). Certain complaints were associated with specific methods of amputation; abnormal keratosis in Syme's amputation, equinus deformity in Chopart's amputation, reduced muscle power in above the knee (A/K) amputation and joint dysfunction in below the knee (B/K) amputation. Adequate prosthetic fitting was achieved by the modification of the socket and alignment in almost all amputees with stump problems. In only two cases, Chopart's amputation required subsequent Syme's amputation due to equinus deformity with abnormal keratosis. In almost every case, stump problems are avoidable by means of surgeons' deliberate evaluation of the affected limb and adequate choice of the amputation level.

  19. Aging and skilled problem solving.

    Science.gov (United States)

    Charness, N

    1981-03-01

    Information-processing models of problem solving too often are based on restrictive age ranges. On the other hand, gerontologists have investigated few problem-solving tasks and have rarely generated explicit models. As this article demonstrates, both fields can benefit by closer collaboration. One major issue in gerontology is whether aging is associated with irreversible decrement or developmental plasticity. If both processes occur, then an appropriate strategy for investigating aging is to equate age groups for molar problem-solving performance and search for differences in the underlying components. This strategy was adopted to examine the relation of age and skill to problem solving in chess. Chess players were selected to vary widely in age and skill such that these variables were uncorrelated. Problem-solving and memory tasks were administered. Skill level was the only significant predictor for accuracy in both a choose-a-move task and a speeded end-game evaluation task. Age (negatively) and skill (positively) jointly determined performance in an unexpected recall task. Efficient chunking in recall was positively related to skill, though negatively related to age. Recognition confidence, though not accuracy, was negatively related to age. Thus despite age-related declines in encoding and retrieval of information, older players match the problem-solving performance of equivalently skilled younger players. Apparently, they can search the problem space more efficiently, as evidenced by taking less time to select an equally good move. Models of chess skill that stress that role of encoding efficiency, as indexed by chunking in recall, need to be modified to account for performance over the life span.

  20. Vehicle routing problem and capacitated vehicle routing problem frameworks in fund allocation problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah@Rozita

    2016-11-01

    Two new methods adopted from methods commonly used in the field of transportation and logistics are proposed to solve a specific issue of investment allocation problem. Vehicle routing problem and capacitated vehicle routing methods are applied to optimize the fund allocation of a portfolio of investment assets. This is done by determining the sequence of the assets. As a result, total investment risk is minimized by this sequence.

  1. Ten Problems in Experimental Mathematics

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, Jonathan M.; Kapoor, Vishaal; Weisstein, Eric

    2004-09-30

    This article was stimulated by the recent SIAM ''100 DigitChallenge'' of Nick Trefethen, beautifully described in a recent book. Indeed, these ten numeric challenge problems are also listed in a recent book by two of present authors, where they are followed by the ten symbolic/numeric challenge problems that are discussed in this article. Our intent was to present ten problems that are characteristic of the sorts of problems that commonly arise in ''experimental mathematics''. The challenge in each case is to obtain a high precision numeric evaluation of the quantity, and then, if possible, to obtain a symbolic answer, ideally one with proof. Our goal in this article is to provide solutions to these ten problems, and in the process present a concise account of how one combines symbolic and numeric computation, which may be termed ''hybrid computation'', in the process of mathematical discovery.

  2. Problem of Time in Quantum Gravity

    CERN Document Server

    Anderson, Edward

    2012-01-01

    The Problem of Time occurs because the `time' of GR and of ordinary Quantum Theory are mutually incompatible notions. This is problematic in trying to replace these two branches of physics with a single framework in situations in which the conditions of both apply, e.g. in black holes or in the very early universe. Emphasis in this Review is on the Problem of Time being multi-faceted and on the nature of each of the eight principal facets. Namely, the Frozen Formalism Problem, Configurational Relationalism Problem (formerly Sandwich Problem), Foliation Dependence Problem, Constraint Closure Problem (formerly Functional Evolution Problem), Multiple Choice Problem, Global Problem of Time, Problem of Beables (alias Problem of Observables) and Spacetime Reconstruction or Replacement Problem. Strategizing in this Review is not just centred about the Frozen Formalism Problem facet, but rather about each of the eight facets. Particular emphasis is placed upon A) relationalism as an underpinning of the facets and as ...

  3. The Problem of Assessing Problem Solving: Can Comparative Judgement Help?

    Science.gov (United States)

    Jones, Ian; Inglis, Matthew

    2015-01-01

    School mathematics examination papers are typically dominated by short, structured items that fail to assess sustained reasoning or problem solving. A contributory factor to this situation is the need for student work to be marked reliably by a large number of markers of varied experience and competence. We report a study that tested an…

  4. Bilinguisme, diglossie, hegemonie: problemes (Problems of Bilingualism, Diglossia, and Hegemony).

    Science.gov (United States)

    Marcellesi, Jean-Baptiste

    1981-01-01

    A brief reveiw of recent literature in France on bilingualism, or more properly, diglossia. In the context of a bi- or pluri-linguistic situation, dialectology, linguistic distribution of both speakers and systems, official and regional languages, and the problem of belonging to a linguistic community and ethnic identification are discussed. (AMH)

  5. Sinus actuator solves emc problems; Sinussteller loest EMV-Probleme

    Energy Technology Data Exchange (ETDEWEB)

    Kammerer, Olaf [Systemtechnik LEBER GmbH und Co. KG, Schwaig (Germany)

    2009-11-15

    The steep slope of the phase angle variation control tend to cause problems of electromagnetic compatibility. A sinus actuator controls the amplitude of the current continuously from 0 to 100 percent. It also has low power loss and requires no rectifier. (orig.)

  6. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander

    2013-12-17

    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  7. On the sample monotonization problem

    Science.gov (United States)

    Takhanov, R. S.

    2010-07-01

    The problem of finding a maximal subsample in a training sample consisting of the pairs “object-answer” that does not violate monotonicity constraints is considered. It is proved that this problem is NP-hard and that it is equivalent to the problem of finding a maximum independent set in special directed graphs. Practically important cases in which a partial order specified on the set of answers is a complete order or has dimension two are considered in detail. It is shown that the second case is reduced to the maximization of a quadratic convex function on a convex set. For this case, an approximate polynomial algorithm based on linear programming theory is proposed.

  8. Coping with persistent environmental problems

    DEFF Research Database (Denmark)

    Varjopuro, Riku; Andrulewicz, Eugeniusz; Brandt, Urs Steiner;

    2014-01-01

    involved in the implementation are keys to improve understanding of the systemic delays. The improved understanding is necessary for the adaptive management of a persistent environmental problem. In addition to the state of the environment, the monitoring and analysis should be targeted also......ABSTRACT In this paper we focus on systemic delays in the Baltic Sea that cause the problem of eutrophication to persist. These problems are demonstrated in our study by addressing three types of delays: (1) decision delay: the time it takes for an idea or perceived need to be launched as a policy...... is to analyze these systemic delays and especially to discuss how the critical delays can be better addressed in marine protection policies by strengthening the adaptive capacity of marine protection. We conclude that the development of monitoring systems and reflexive, participatory analysis of dynamics...

  9. Mathematical problems in meteorological modelling

    CERN Document Server

    Csomós, Petra; Faragó, István; Horányi, András; Szépszó, Gabriella

    2016-01-01

    This book deals with mathematical problems arising in the context of meteorological modelling. It gathers and presents some of the most interesting and important issues from the interaction of mathematics and meteorology. It is unique in that it features contributions on topics like data assimilation, ensemble prediction, numerical methods, and transport modelling, from both mathematical and meteorological perspectives. The derivation and solution of all kinds of numerical prediction models require the application of results from various mathematical fields. The present volume is divided into three parts, moving from mathematical and numerical problems through air quality modelling, to advanced applications in data assimilation and probabilistic forecasting. The book arose from the workshop “Mathematical Problems in Meteorological Modelling” held in Budapest in May 2014 and organized by the ECMI Special Interest Group on Numerical Weather Prediction. Its main objective is to highlight the beauty of the de...

  10. Linear and complex analysis problem

    CERN Document Server

    Nikolski, Nikolai

    1994-01-01

    The 2-volume-book is an updated, reorganized and considerably enlarged version of the previous edition of the Research Problem Book in Analysis (LNM 1043), a collection familiar to many analysts, that has sparked off much research. This new edition, created in a joint effort by a large team of analysts, is, like its predecessor, a collection of unsolved problems of modern analysis designed as informally written mini-articles, each containing not only a statement of a problem but also historical and metho- dological comments, motivation, conjectures and discussion of possible connections, of plausible approaches as well as a list of references. There are now 342 of these mini- articles, almost twice as many as in the previous edition, despite the fact that a good deal of them have been solved!

  11. Java problem-based learning

    Directory of Open Access Journals (Sweden)

    Goran P, Šimić

    2012-01-01

    Full Text Available The paper describes the self-directed problem-based learning system (PBL named Java PBL. The expert module is the kernel of Java PBL. It involves a specific domain model, a problem generator and a solution generator. The overall system architecture is represented in the paper. Java PBL can act as the stand-alone system, but it is also designed to provide support to learning management systems (LMSs. This is provided by a modular design of the system. An LMS can offer the declarative knowledge only. Java PBL offers the procedural knowledge and the progress of the learner programming skills. The free navigation, unlimited numbers of problems and recommendations represent the main pedagogical strategies and tactics implemented into the system.

  12. Topology optimization of flow problems

    DEFF Research Database (Denmark)

    Gersborg, Allan Roulund

    2007-01-01

    This thesis investigates how to apply topology optimization using the material distribution technique to steady-state viscous incompressible flow problems. The target design applications are fluid devices that are optimized with respect to minimizing the energy loss, characteristic properties...... transport in 2D Stokes flow. Using Stokes flow limits the range of applications; nonetheless, the thesis gives a proof-of-concept for the application of the method within fluid dynamic problems and it remains of interest for the design of microfluidic devices. Furthermore, the thesis contributes....... Although the study of the FVM is carried out using a simple heat conduction problem, the work illuminates and discusses the technicalities of employing the FVM in connection with topology optimization. Finally, parallelized solution methods are investigated using the high performance computing facility...

  13. Problems in structural inorganic chemistry

    CERN Document Server

    Li, Wai-Kee; Mak, Thomas Chung Wai; Mak, Kendrew Kin Wah

    2013-01-01

    This book consists of over 300 problems (and their solutions) in structural inorganic chemistry at the senior undergraduate and beginning graduate level. The topics covered comprise Atomic and Molecular Electronic States, Atomic Orbitals, Hybrid Orbitals, Molecular Symmetry, Molecular Geometry and Bonding, Crystal Field Theory, Molecular Orbital Theory, Vibrational Spectroscopy, and Crystal Structure. The central theme running through these topics is symmetry, molecular or crystalline. The problems collected in this volume originate in examination papers and take-home assignments that have been part of the teaching of the book's two senior authors' at The Chinese University of Hong Kong over the past four decades. The authors' courses include Chemical Bonding, Elementary Quantum Chemistry, Advanced Inorganic Chemistry, X-Ray Crystallography, etc. The problems have been tested by generations of students taking these courses.

  14. Problem-oriented project studies

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Danielsen, Oluf

    2010-01-01

    and marking papers / essays is complemented and in some way overruled by a new role as supervisor and facilitator for the group of students working with a research problem, they themselves have picked. However different dimensions of this new teacher role can be seen – from expert in an academic field (result......This contribution focuses on 'problem based learning' (however we prefer the notion of ‘problem-oriented project studies’) and the role of the teacher in such a context. The classic traditional role as an expert deciding the curriculum, providing lectures and seminars, giving assignments......-oriented focusing on how the final product demonstrates the students’ ‘correct’ way to handle the academic aspects of the subject in mind) to a role more focusing on processes, methodological dimensions and stressing the importance of a reflexive approach. Some teachers may even tend to take on a role...

  15. Problem-Based Learning Online

    DEFF Research Database (Denmark)

    Kolbæk, Ditte; Nortvig, Anne-Mette

    2017-01-01

    Problem- and Project-Based Learning (PBL) is a widely used pedagogical method in higher education. Although PBL encourages self-directed learning and works with the students’ own projects and problems, it also includes teacher presentations, discussions and group reflections, both on......-campus and online. Therefore, the teacher’s plans might be relevant to the students’ projects, but that is not always the case. This study investigates how master’s students interact with an online Problem-Based Learning design and examines how technology influences these interactions. The empirical data stem from...... lessons at an online master’s course, and they were collected and analyzed using a netnographic approach. The study finds that concepts like self-directed learning and active involvement of everyone can have very different meanings from the teachers’ and the students’ points of view. If the students do...

  16. Linear and complex analysis problem

    CERN Document Server

    Nikolski, Nikolai

    1994-01-01

    The 2-volume book is an updated, reorganized and considerably enlarged version of the previous edition of the Research Problem Book in Analysis (LNM 1043), a collection familiar to many analysts, that has sparked off much research. This new edition, created in a joint effort by a large team of analysts, is, like its predecessor, a collection of unsolved problems of modern analysis designed as informally written mini-articles, each containing not only a statement of a problem but also historical and methodological comments, motivation, conjectures and discussion of possible connections, of plausible approaches as well as a list of references. There are now 342 of these mini- articles, almost twice as many as in the previous edition, despite the fact that a good deal of them have been solved!

  17. The Random Quadratic Assignment Problem

    Science.gov (United States)

    Paul, Gerald; Shao, Jia; Stanley, H. Eugene

    2011-11-01

    The quadratic assignment problem, QAP, is one of the most difficult of all combinatorial optimization problems. Here, we use an abbreviated application of the statistical mechanics replica method to study the asymptotic behavior of instances in which the entries of at least one of the two matrices that specify the problem are chosen from a random distribution P. Surprisingly, the QAP has not been studied before using the replica method despite the fact that the QAP was first proposed over 50 years ago and the replica method was developed over 30 years ago. We find simple forms for C min and C max , the costs of the minimal and maximum solutions respectively. Notable features of our results are the symmetry of the results for C min and C max and their dependence on P only through its mean and standard deviation, independent of the details of P.

  18. Fluid mechanics problems and solutions

    CERN Document Server

    Spurk, Joseph H

    1997-01-01

    his collection of over 200 detailed worked exercises adds to and complements the textbook Fluid Mechanics by the same author, and illustrates the teaching material through examples. In the exercises the fundamental concepts of Fluid Mechanics are applied to obtaining the solution of diverse concrete problems, and in doing this the student's skill in the mathematical modeling of practical problems is developed. In addition, 30 challenging questions without detailed solutions have been included, and while lecturers will find these questions suitable for examinations and tests, the student himself can use them to check his understanding of the subject.

  19. Tackling Problems in Reading Efficiency

    Institute of Scientific and Technical Information of China (English)

    赵维红

    2009-01-01

    Reading is a complex,communicative process,which involves both linguistic and cognitive knowledge.The lack of either part will cause inefficiency.So,this paper deals with problems in reading efficiency in English study for college students in China.It analyzes the problems with regard to linguistic knowledge and cognitive schemata,emphasizing that solid linguistic foundation is the premise,and active communication skills are catalytic promoters while formal scientific training is necessary,and proposes some countermeasures on how to en hance the college student's reading efficiency.

  20. Psychosocial Problems during Infertility Treatment

    Directory of Open Access Journals (Sweden)

    Nurcan Kirca

    2013-06-01

    Full Text Available Infertility is a complex situation crisis which is often psychologically-threatening and emotionally stressful for both partners as well as economically expensive and causes physical pain due to the operations performed for diagnosis and treatment purposes. Infertility has physical, psychological, social, emotional and financial impacts. Infertile couples are under a great social pressure, and need to conceal the problem as it is exceptionally private for them. Infertile individuals are destitute of support when they do not share their pregnancy problems with their families and relatives. Couples define their infertility experience as the most stressful experience of their lives.

  1. The three-body problem

    CERN Document Server

    Marchal, Christian

    1990-01-01

    Recent research on the theory of perturbations, the analytical approach and the quantitative analysis of the three-body problem have reached a high degree of perfection. The use of electronics has aided developments in quantitative analysis and has helped to disclose the extreme complexity of the set of solutions. This accelerated progress has given new orientation and impetus to the qualitative analysis that is so complementary to the quantitative analysis. The book begins with the various formulations of the three-body problem, the main classical results and the important questions and conje

  2. Several difficult problems in lubrication

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Whether in industry or in our human life, we will encounter many lubrication problems. A goodlubricant not only should have good performance, but also should meet the needs of the specific condi-tions. Here we give some examples about the difficult problems in lubrication and their solutions. Theseexamples are: (i) hydrolysis and emulsion of ZDTP; (ii) corrosion of chlorowax; (iii) coexistence of greencompressor oil and cryogen (R-134A); (iv) lubrication of cystoscope and catheter. On the same time,some achievements in lubrication field provided by Lubrication Chemistry Laboratory of Shanghai Uni-versity will be introduced in this paper.

  3. [Psychological problems of thalassemic subjects].

    Science.gov (United States)

    Guasco, G; La Mantia, A; Cuniolo, A

    1987-01-01

    Analysis of psychological problems of the thalassemic subject shown with these following tests: Der Baumtest, drawing of the human figure. Moreover, we made meetings with all boys and their parents during their stay in the day-hospital. These tests have shown subjective conflicts (fear and uncertainty of future due to illness felt as aggression and fault, depressive moods and loneliness, problems of communication, hope in a magic recovery opposite to the constant discomfort of the therapeutic dependence) and relational conflicts (ambivalence towards parents, difficulties in becoming a part of the social and school environment).

  4. Interactive problem solving using LOGO

    CERN Document Server

    Boecker, Heinz-Dieter; Fischer, Gerhard

    2014-01-01

    This book is unique in that its stress is not on the mastery of a programming language, but on the importance and value of interactive problem solving. The authors focus on several specific interest worlds: mathematics, computer science, artificial intelligence, linguistics, and games; however, their approach can serve as a model that may be applied easily to other fields as well. Those who are interested in symbolic computing will find that Interactive Problem Solving Using LOGO provides a gentle introduction from which one may move on to other, more advanced computational frameworks or more

  5. Topology Optimization for Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    2011-01-01

    This report deals with the topology optimization of convection problems.That is, the aim of the project is to develop, implement and examine topology optimization of purely thermal and coupled thermomechanical problems,when the design-dependent eects of convection are taken into consideration.......This is done by the use of a self-programmed FORTRAN-code, which builds on an existing 2D-plane thermomechanical nite element code implementing during the course `41525 FEM-Heavy'. The topology optimizationfeatures have been implemented from scratch, and allows the program to optimize elastostatic mechanical...

  6. A Formal Description of Problem Frames

    Directory of Open Access Journals (Sweden)

    Souleymane KOUSSOUBE

    2014-03-01

    Full Text Available Michael Jackson defines a Problem Frame as a mean to describe and classify software development problems. The initial description of problem Frames is essentially graphical. A weakness of this proposal is the lack of formal specification allowing efficient reasoning tools. This paper deals with Problem Frames’ formal specification with Description Logics. We first propose a formal terminology of Problem Frames leading to the specification of a Problem Frames’ TBOX and a specific problem’s ABOX. The Description Logics inference tools can then be used to decompose multi frame problems or to fix a particular problem into a Problem Frame.

  7. Toxaphene: a challenging analytical problem

    NARCIS (Netherlands)

    Geus, de H.J.; Wester, P.G.; Schelvis, A.; Boer, de J.; Brinkman, U.A.Th.

    2000-01-01

    The analysis of toxaphene, a highly complex mixture of chlorinated bornanes, bornenes and camphenes, is a challenging problem, especially as individual congeners are present at trace levels in biota and other relevant samples. The complicated nomenclature of the compounds of interest is briefly disc

  8. Problem Gambling on College Campuses

    Science.gov (United States)

    McComb, Jennifer L.; Hanson, William E.

    2009-01-01

    The vast majority of college students gamble, with some doing so problematically. This article discusses gambling and problem gambling among college students, framing it as an emerging health issue on college campuses nationwide. Given that 4 out of 5 college students admit to gambling, and that approximately 8% gamble problematically, it is…

  9. Introduction: Unsolved Problems on Noise

    Science.gov (United States)

    Oriols, X.; Ciliberto, S.

    2016-05-01

    This paper is an introduction to the special issue of the 7th Int. Conf. on Unsolved Problems on Noise (UPoN) that took place at Casa Convalescència in Barcelona (Spain) in July 2015. The aim of the UPoN conferences is to provide a forum for researchers working on different fields of noise, fluctuations and variability, where they present their scientific problems which resist solutions. The papers of this Special Issue reflect the interdisciplinary topics (physics, biology, circuits, financial markets, psychology, technology, etc) presented at the UPoN conference. Noise is not only a hindrance to signal detection, but it is indeed a valuable source of information (not present in the signal) that help us to get a deeper understanding on how Nature works. This special issue of the 7th International Conference on Unsolved Problems on Noise (UPoN) is dedicated to Laszlo Kish in the occasion of his 60th birthday. He organized the first edition of these UPoN conferences in Szeged (Hungary) in 1996. Many of us have greatly benefited from his ‘volcanic imagination in tackling new problems from unconventional points of views’.

  10. Frames and extension problems I

    DEFF Research Database (Denmark)

    Christensen, Ole

    2014-01-01

    In this article we present a short survey of frame theory in Hilbert spaces. We discuss Gabor frames and wavelet frames and set the stage for a discussion of various extension principles; this will be presented in the article Frames and extension problems II (joint with H.O. Kim and R.Y. Kim)....

  11. The Problem of Private Language

    Directory of Open Access Journals (Sweden)

    M.A Abdollahi

    2014-09-01

    This language is, according to Wittgenstein, impossible because it leads to epistemological and semantic skepticism. The definition of private language contains two elements: the “privacy” and “referring to”. Wittgenstein shows how we may be trapped in solipsism and the only way to avoid this problem is to consider language as a social phenomenon.

  12. The distributed wireless gathering problem

    NARCIS (Netherlands)

    Bonifaci, V.; Korteweg, P.; Spaccamela, A. Marchetti; Stougie, L.

    2011-01-01

    We address the problem of data gathering in a wireless network using multi-hop communication; our main goal is the analysis of simple algorithms suitable for implementation in realistic scenarios. We study the performance of distributed algorithms, which do not use any form of local coordination, an

  13. Musculoskeletal problems in stroke survivors.

    Science.gov (United States)

    Kendall, Richard

    2010-01-01

    Musculoskeletal problems in stoke survivors are common reasons for disability and pain. Shoulder pain is present in 24% of stroke survivors among all complications, second only to depression in 26%. Diagnosis and treatment of the various shoulder pain etiologies can significantly improve quality of life in these patients. This article reviews the common etiologies and treatments of shoulder and hip pain in stroke survivors.

  14. PROBLEMS IN MEASURING CUSTOMER SATISFACTION

    OpenAIRE

    Isac Florin Lucian; Rusu Sergiu; Cureteanu Radu Silviu

    2012-01-01

    Companies that embrace client orientation are preoccupied by measuring the level of satisfaction of those who consume their products or utilizes their products. That is why, customer satisfaction has to be transposed in measurable parameters that can be understood and influenced. Nevertheless, measuring customer satisfaction involves a lot of problems.

  15. PROBLEMS IN MEASURING CUSTOMER SATISFACTION

    Directory of Open Access Journals (Sweden)

    Isac Florin Lucian

    2012-12-01

    Full Text Available Companies that embrace client orientation are preoccupied by measuring the level of satisfaction of those who consume their products or utilizes their products. That is why, customer satisfaction has to be transposed in measurable parameters that can be understood and influenced. Nevertheless, measuring customer satisfaction involves a lot of problems.

  16. On the buckling eigenvalue problem

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Pedro R S, E-mail: pant@cii.fc.ul.pt [Departamento de Matematica, Universidade Lusofona de Humanidades e Tecnologias, Av. do Campo Grande, 376, 1749-024 Lisboa (Portugal); Group of Mathematical Physics of the University of Lisbon, Complexo Interdisciplinar, Av. Professor Gama Pinto 2, P-1649-003 Lisboa (Portugal)

    2011-05-27

    We prove a density result which allows us to justify the application of the method of fundamental solutions to solve the buckling eigenvalue problem of a plate. We address an example of an analytic convex domain for which the first eigenfunction does change the sign and present a large-scale numerical study with polygons providing numerical evidence to some new conjectures.

  17. Polyomino Problems to Confuse Computers

    Science.gov (United States)

    Coffin, Stewart

    2009-01-01

    Computers are very good at solving certain types combinatorial problems, such as fitting sets of polyomino pieces into square or rectangular trays of a given size. However, most puzzle-solving programs now in use assume orthogonal arrangements. When one departs from the usual square grid layout, complications arise. The author--using a computer,…

  18. Risks for Heart Valve Problems

    Science.gov (United States)

    ... individual risk and the recommendations with your doctor. Aging people should also be aware of changes that may come on very gradually . Not all declines in energy or stamina are related to “the normal problems of getting older.” When the heart fails ...

  19. On the optimal sizing problem

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1994-01-01

    The paper studies the problem of determining the number and dimensions of sizes of apparel so as to maximize profits. It develops a simple one-variable bisection search algorithm that gives the optimal solution. An example is solved interactively using a Macintosh LC and Math CAD, a mathematical ...

  20. Inflation and the Measurement Problem

    CERN Document Server

    Alexander, Stephon; Magueijo, Joao

    2016-01-01

    We discuss the cosmological measurement problem (see [1] for a review), and propose a solution. Our approach is an effective wavefunction collapse mechanism arising from a novel interaction between Fourier modes, to be contrasted with fundamental modifications to the Schrodinger equation [2, 3].

  1. Building Collections. The Problem Novel

    Science.gov (United States)

    Krapp, JoAnn Vergona

    2005-01-01

    Realistic fiction has changed dramatically over the years. Formerly a sentimental, family-oriented story, today's realism focuses on today's problems and the protagonist's struggle to overcome them. Parents, once portrayed as protectors of the children, now often are cast as failures, needing help themselves. Yesterday's taboo subjects--drugs,…

  2. The Scientist as Problem Solver.

    Science.gov (United States)

    1989-01-01

    history. or imagined history. no magic and no mystery Each step appears to proceed. if not inexorably at least plausibly from the preceding one If the...discovery process appears quite unremarkable. The problem was found in the literatue (Goodwin S paper). and it can be represented in a quite standard way by

  3. What’s Your Problem?

    DEFF Research Database (Denmark)

    Knudsen, Sanne

    is different from or even contradictory of their previous writing experiences. Or, as Maggi Savin-Baden concludes; "It is naïve to assume that it is possible to adopt problem-based learning with ease". Nevertheless, there is little research on students' generic competence in negotiating and constructing...

  4. Family Problems and Youth Unemployment.

    Science.gov (United States)

    de Goede, Martijn; Spruijt, Ed; Maas, Cora; Duindam, Vincent

    2000-01-01

    Examines how family and personal characteristics relate to the employment situation of adolescents (N=995) in Denmark. Results show that parental divorce, parental unemployment (only for males), low parental affective involvement, and adolescent relationship problems were related to youth unemployment, but educational career and work commitment…

  5. Beginnings of the Cauchy problem

    CERN Document Server

    Choquet-Bruhat, Yvonne

    2014-01-01

    Brief account of results on the Cauchy problem for the Einstein equations starting with early the works of Darmois and Lichnerowicz and going up to the proofs of the existence and uniqueness of solutions global in space and local in time, in Sobolev spaces, for the general equations either in vacuum or with classical sources.

  6. Investigating the Antibiotic Resistance Problem.

    Science.gov (United States)

    Lawson, Michael; Lawson, Amy L.

    1998-01-01

    Seeks to give teachers useful information on the extent of the problem of antibiotic-resistant bacteria, mechanisms bacteria use to resist antibiotics, the causes of the emergence of antibiotic-resistant organisms, and practices that can prevent or reverse this trend. Contains 19 references. (DDR)

  7. Problem-Oriented Project Studies

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Danielsen, Oluf

    2012-01-01

    Focus is on problem-based learning in a networked learning context with focus on the use of technologies in the communicative processes among the participants. Especially, the role of the teacher in such a context is analysed. The classic, traditional role as an expert deciding the curriculum, pr...

  8. On transfer during problem solving

    NARCIS (Netherlands)

    Hamel, R.; Jakab, E.

    2013-01-01

    A puzzle is equally new for everyone who is presented with it for the first time. However, it is not if we take one’s previous knowledge into account. Some knowledge may be utilised while working on the puzzle. If this is the case, problem solving as well as the development of knowledge about the pu

  9. The bicriterion stochastic knapsack problem

    DEFF Research Database (Denmark)

    Andersen, Kim Allan

    We discuss the bicriterion stochastic knapsack problem. It is described as follows. We have a known capacity of some resource, and a finite set of projects. Each project requires some units of the resource which is not known in advance, but given by a discrete probability distribution with a finite...

  10. Is the Age Problem Resolved?

    Indian Academy of Sciences (India)

    Ali Akbar Navabi; Nematollah Riazi

    2003-03-01

    The cosmological, astrophysical, and nucleocosmochronological methods for estimating the age of the universe and the corresponding uncertainties are comparatively studied in the present paper.We are led to the conclusion that the newmeasurements of cosmological parameters, and the recent estimates of the age of globular clusters have led to the gradual disappearance of the age problem from the arena of modern cosmology.

  11. Restricted Morgan’s problem

    Institute of Scientific and Technical Information of China (English)

    陈树中; 曹立

    1996-01-01

    A new list of regular feedback invariant integers called right independent orders is introduced.That the restricted Morgan’s problem is equivalent to a kind of nonlinear algebraic equations is proved and the condition that the nonlinear algebraic equations degenerate into linear algebraic equations is given.

  12. Solving the wrong hierarchy problem

    Science.gov (United States)

    Blinov, Nikita; Hook, Anson

    2016-06-01

    Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and Z_2 -symmetric theories where the Standard Model Higgs potential has two vacua. The parity or Z_2 copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to the Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop this idea in the context of a solution to the strong CP problem. We show this mechanism postdicts the top Yukawa to be within 1 σ of the currently measured value and predicts scalar color octets with masses in the range 9-200 TeV.

  13. On Labeled Traveling Salesman Problems

    DEFF Research Database (Denmark)

    Couetoux, Basile; Gourves, Laurent; Monnot, Jerome;

    2008-01-01

    We consider labeled Traveling Salesman Problems, defined upon a complete graph of n vertices with colored edges. The objective is to find a tour of maximum (or minimum) number of colors. We derive results regarding hardness of approximation, and analyze approximation algorithms for both versions...

  14. Studying Death: Problems of Methodology.

    Science.gov (United States)

    Simpson, Michael A.

    1980-01-01

    The methods and problems of research on the psychology of death include ethical difficulties, the conceptual poverty and oversimplification of most rating systems, and an overemphasis on anxiety and fear. The changes resulting from death education or therapy and their relation to modes of denial should be studied. (Author)

  15. "Top School Problems" Are Myths.

    Science.gov (United States)

    Males, Mike

    1992-01-01

    A well-known "study" comparing the top school problems of 1940 (talking and gum chewing) with those of 1987 (drug abuse, pregnancy, and violence) is nonexistent. In 1940, 49 percent of all youth did not finish high school, 37,000 teenagers died from violence or disease, and 335,000 teens gave birth. Educators should discount pastoral memories and…

  16. Dyslexia: Problems of Reading Disabilities.

    Science.gov (United States)

    Goldberg, Herman K.; Schiffman, Gilbert B.

    The purpose of this book is to provide an understanding of both the educational and medical aspects of reading and to show how they are interrelated in reading disabilities. The various aspects of reading disabilities are presented in the following chapters: Introduction to the Reading Problem; Early Predictive Studies; Psychological Evaluation;…

  17. Problem behavior in Dutch preschoolers

    NARCIS (Netherlands)

    J.M. Koot (Hans)

    1993-01-01

    textabstractThe present study was an attempt to contribute to the standardized assessment and the study of prevalence of problem behavior in children 2- to 3-years old by means of empirically derived rating scales. The basic questions were: 1. What are the psychometric characteristics of the Dutch v

  18. Management problems of staff motivation

    OpenAIRE

    PUZYNYA T.A.

    2015-01-01

    Staff motivation is a major link in improving the competitiveness of any organization. One of the main problems of management of motivation of staff is the individuality of each employee, so the knowledge of psychology and individual needs will help organizations effectively manage staff.

  19. DSM-5: problems and suggestions.

    Science.gov (United States)

    Birgegård, Andreas; Groß, Gaby; de Man Lapidoth, Joakim; Norring, Claes

    2013-01-01

    The upcoming DSM5 will impact clinical work and research substantially, and we here point to a few problems that may have been overlooked. These concern inconsistencies and lack of clarity, and the future "not elsewhere classified" atypical anorexia nervosa category. We propose solutions in the form of working definitions and operationalizations to facilitate clinical implementation as well as streamline research.

  20. Linearization problem in pseudolite surveys

    Science.gov (United States)

    Cellmer, Slawomir; Rapinski, Jacek

    2010-06-01

    GPS augmented with pseudolites (PL), can be used in various engineering surveys. Also pseudolite—only navigation system can be designed and used in any place, even if GPS signal is not available (Kee et al. Development of indoor navigation system using asynchronous pseudolites, 1038-1045, 2000). Especially in engineering surveys, where harsh survey environment is common, pseudolites have a lot of applications. Pseudolites may be used in construction sites, open pit mines, city canyons, GPS and PL baseline processing is similar, although there are few differences that must be taken into account. One of the major issues is linearization problem. The source of the problem is neglecting second terms of Taylor series expansion in GPS baseline processing software. This problem occurs when the pseudolite is relatively close to the receiver, which is the case in PL surveys. In this paper authors presents the algorithm for GPS + PL data processing including, neglected in classical GPS only approach, second terms of Taylor series expansion. The mathematical model of adjustment problem, detailed proposal of application in baseline processing algorithms, and numerical tests are presented.

  1. PROBLEMS IN MODERN GREEK LEXICOGRAPHY.

    Science.gov (United States)

    KAHANE, HENRY; KAHANE, RENEE

    PROBLEMS DEALING WITH LEVELS OF SPEECH AND LEVELS OF ANALYSIS IN CONNECTION WITH MODERN GREEK LEXICOGRAPHICAL STUDY WERE DISCUSSED. CONCERNING THE POSSIBLE CONSTRUCTION OF A COMPETENT BILINGUAL DICTIONARY, THE INVESTIGATORS SUGGESTED THAT THE VARIOUS STRUCTURES (NAMELY, PHONOLOGY, MORPHOLOGY, AND SYNTAX) BE TIED TOGETHER TO INVOLVE (1) LISTING IN…

  2. Problem Solvers' Conceptions about Osmosis.

    Science.gov (United States)

    Zuckerman, June T.

    1994-01-01

    Discusses the scheme and findings of a study designed to identify the conceptual knowledge used by high school students to solve a significant problem related to osmosis. Useful tips are provided to teachers to aid students in developing constructs that maximize understanding. (ZWH)

  3. Personal Law and Consumer Problems

    Science.gov (United States)

    Graf, David

    1972-01-01

    There is little doubt at Minnetonka High School that the integrated personal law and consumer problems course is effective. The areas studied promote variety, concentration on vital matters, and student interest in the business department as a source of general education. (Author)

  4. Adopting Children with Attachment Problems.

    Science.gov (United States)

    Hughes, Daniel A.

    1999-01-01

    Notes that attachment behavior in infants is a facet of normal child development, and that children with attachment problems require special attention during and after the adoption process. Presents actions needed to increase the probability that such children can be successfully adopted, detailed attachment patterns, and parenting strategies and…

  5. Robot computer problem solving system

    Science.gov (United States)

    Becker, J. D.; Merriam, E. W.

    1974-01-01

    The conceptual, experimental, and practical aspects of the development of a robot computer problem solving system were investigated. The distinctive characteristics were formulated of the approach taken in relation to various studies of cognition and robotics. Vehicle and eye control systems were structured, and the information to be generated by the visual system is defined.

  6. The Commons Problem: Alternative Perspectives.

    Science.gov (United States)

    Edney, Julian J.

    1980-01-01

    Reviews four contrasting theories bearing on the concept of the commons dilemma, which deals with conflicts of individual v group interests over time. Focuses on the threats that commons problems pose to democratic principles in community structure. Discusses alternative directions for the resolution of resource crises. (Author/GC)

  7. Dose response problems in carcinogenesis.

    Science.gov (United States)

    Crump, K S

    1979-03-01

    The estimation of risks from exposure to carcinogens is an important problem from the viewpoint of protection of human health. It also poses some very difficult dose-response problems. Two dose-response models may fit experimental data about equally well and yet predict responses that differ by many orders of magnitude at low doses. Mechanisms of carcinogenesis are not sufficiently understood so that the shape of the dose-response curve at low doses can be satisfactorily predicted. Mathematical theories of carcinogenesis and statistical procedures can be of use with dose-reponse problems such as this and, in addition, can lead to a better understanding of the mechanisms of carcinogenesis. In this paper, mathematical dose-response models of carcinogenesis are considered as well as various proposed dose-response procedures for estimating carcinogenic risks at low doses. Areas are suggested in which further work may be useful. These areas include experimental design problems, statistical procedures for use with time-to-occurrence data, and mathematical models that incorporate such biological features as pharmacokinetics of carcinogens, synergistic effects, DNA repair, susceptible subpopulations, and immune reactions.

  8. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree discriminant. T

  9. Problems in unification and supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, G.; Henyey, F. (eds.)

    1984-01-01

    Problems in unification of the various gauge groups, quantum gravity, supersymmetry and supergravity, compact dimensions of space-time, and conditions at the beginning of the universe are discussed. Separate entries were prepared for the data base for the 15 papers presented. (WHK)

  10. Human Problem Solving in 2006

    Science.gov (United States)

    Pizlo, Zygmunt

    2007-01-01

    This paper presents a bibliography of a little more than 100 references related to human problem solving, arranged by subject matter. The references were taken from PsycInfo and Compendex databases. Only journal papers, books and dissertations are included. The topics include human development, education, neuroscience, research in applied…

  11. The P versus NP Problem

    CERN Document Server

    Dube, Rakesh

    2010-01-01

    Removed by arXiv administration. This article was plagiarized directly from Stephen Cook's description of the problem for the Clay Mathematics Institute. See http://gauss.claymath.org:8888/millennium/P_vs_NP/pvsnp.pdf for the original text.

  12. Modified Block Iterative Method for Solving Convex Feasibility Problem, Equilibrium Problems and Variational Inequality Problems

    Institute of Scientific and Technical Information of China (English)

    Shi Sheng ZHANG; Chi Kin CHAN; H.W. JOSEPH LEE

    2012-01-01

    The purpose of this paper is by using the modified block iterative method to propose an algorithm for finding a common element in the intersection of the set of common fixed points of an infinite family of quasi-φ-asymptotically nonexpansive and the set of solutions to an equilibrium problem and the set of solutions to a variational inequality.Under suitable conditions some strong convergence theorems are established in 2-uniformly convex and uniformly smooth Banach spaces.As applications we utilize the results presented in the paper to solving the convex feasibility problem (CFP) and zero point problem of maximal monotone mappings in Banach spaces.The results presented in the paper improve and extend the corresponding results announced by many authors.

  13. Genetic Algorithm for Chinese Postman Problems

    Institute of Scientific and Technical Information of China (English)

    Jiang Hua; Kang Li-shan

    2003-01-01

    Chinese Postman Problem is an unsettled graphic problem. It was approached seldom by evolutionary computation. Now we use genetic algorithm to solve Chinese Postman Problem in undirected graph and get good results. It could be extended to solve Chinese postman problem in directed graph. We make these efforts for exploring in optimizing the mixed Chinese postman problem.

  14. Anticipating Student Responses to Improve Problem Solving

    Science.gov (United States)

    Wallace, Ann H.

    2007-01-01

    This article illustrates how problem solving can be enhanced through careful planning and problem presentation. Often, students shut down or are turned off when presented with a problem to solve. The author describes how to motivate students to embrace a problem to be solved and provides helpful prompts to further the problem-solving process.…

  15. Problems on Divisibility of Binomial Coefficients

    Science.gov (United States)

    Osler, Thomas J.; Smoak, James

    2004-01-01

    Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…

  16. Governance of wicked climate adaptation problems

    NARCIS (Netherlands)

    Termeer, C.J.A.M.; Dewulf, A.; Breeman, G.E.

    2013-01-01

    Climate change adaptation has been called a “wicked problem par excellence.” Wicked problems are hard to define because ‘the formulation of the problem is the problem; they are considered a symptom of another problem; they are highly resistant to solutions and extremely interconnected with other pro

  17. STEM education and Fermi problems

    Science.gov (United States)

    Holubova, Renata

    2017-01-01

    One of the research areas of Physics education is the study of the educational process. Investigations in this area are aimed for example on the teaching and learning process and its results. The conception of STEM education (Science, Technology, Engineering, and Mathematics) is discussed - it is one possible approach to the preparation of the curriculum and the focus on the educational process at basic and secondary schools. At schools in the Czech Republic STEM is much more realized by the application of interdisciplinary relations between subjects Physics-Nature-Technique. In both conceptions the aim is to support pupils' creativity, critical thinking, cross-curricular links. In this context the possibility of using Fermi problems in teaching Physics was discussed (as an interdisciplinary and constructivist activity). The aim of our research was the analysis of Fermi problems solving strategies, the ability of pupils to solve Fermi problems. The outcome of our analysis was to find out methods and teaching strategies which are important to use in teaching - how to solve qualitative and interdisciplinary tasks in physics. In this paper the theoretical basis of STEM education and Fermi problems will be presented. The outcome of our findings based on the research activities will be discussed so as our experiences from 10 years of Fermi problems competition that takes place at the Science Faculty, Palacky University in Olomouc. Changes in competencies of solving tasks by our students (from the point of view in terms of modern, activating teaching methods recommended by theory of Physics education and other science subjects) will be identified.

  18. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  19. PTSD and Problems with Alcohol Use

    Science.gov (United States)

    ... Enter ZIP code here PTSD and Problems with Alcohol Use Public This section is for Veterans, General Public, Family, & Friends PTSD and Problems with Alcohol Use PTSD and alcohol use problems are often ...

  20. Problem solving using soft systems methodology.

    Science.gov (United States)

    Land, L

    This article outlines a method of problem solving which considers holistic solutions to complex problems. Soft systems methodology allows people involved in the problem situation to have control over the decision-making process.

  1. Vision Problems in the U.S.

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  2. Non-normal Hasemann Boundary Value Problem

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We will discuss the non-normal Hasemann boundary value problem:we may find these results are coincided with those of normal Hasemann boundary value problem and non normal Riemann boundary value problem.

  3. A bicriterion Steiner tree problem on graph

    Directory of Open Access Journals (Sweden)

    Vujošević Mirko B.

    2003-01-01

    Full Text Available This paper presents a formulation of bicriterion Steiner tree problem which is stated as a task of finding a Steiner tree with maximal capacity and minimal length. It is considered as a lexicographic multicriteria problem. This means that the bottleneck Steiner tree problem is solved first. After that, the next optimization problem is stated as a classical minimums Steiner tree problem under the constraint on capacity of the tree. The paper also presents some computational experiments with the multicriteria problem.

  4. A Novel Metaheuristic for Travelling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Vahid Zharfi

    2013-01-01

    Full Text Available One of the well-known combinatorial optimization problems is travelling salesman problem (TSP. This problem is in the fields of logistics, transportation, and distribution. TSP is among the NP-hard problems, and many different metaheuristics are used to solve this problem in an acceptable time especially when the number of cities is high. In this paper, a new meta-heuristic is proposed to solve TSP which is based on new insight into network routing problems.

  5. Modern problems in insurance mathematics

    CERN Document Server

    Martin-Löf, Anders

    2014-01-01

    This book is a compilation of 21 papers presented at the International Cramér Symposium on Insurance Mathematics (ICSIM) held at Stockholm University in June, 2013. The book comprises selected contributions from several large research communities in modern insurance mathematics and its applications. The main topics represented in the book are modern risk theory and its applications, stochastic modelling of insurance business, new mathematical problems in life and non-life insurance, and related topics in applied and financial mathematics. The book is an original and useful source of inspiration and essential reference for a broad spectrum of theoretical and applied researchers, research students and experts from the insurance business. In this way, Modern Problems in Insurance Mathematics will contribute to the development of research and academy–industry co-operation in the area of insurance mathematics and its applications.

  6. Modern solvers for Helmholtz problems

    CERN Document Server

    Tang, Jok; Vuik, Kees

    2017-01-01

    This edited volume offers a state of the art overview of fast and robust solvers for the Helmholtz equation. The book consists of three parts: new developments and analysis in Helmholtz solvers, practical methods and implementations of Helmholtz solvers, and industrial applications. The Helmholtz equation appears in a wide range of science and engineering disciplines in which wave propagation is modeled. Examples are: seismic inversion, ultrasone medical imaging, sonar detection of submarines, waves in harbours and many more. The partial differential equation looks simple but is hard to solve. In order to approximate the solution of the problem numerical methods are needed. First a discretization is done. Various methods can be used: (high order) Finite Difference Method, Finite Element Method, Discontinuous Galerkin Method and Boundary Element Method. The resulting linear system is large, where the size of the problem increases with increasing frequency. Due to higher frequencies the seismic images need to b...

  7. Inconsistent Investment and Consumption Problems

    DEFF Research Database (Denmark)

    Kronborg, Morten Tolver; Steffensen, Mogens

    2015-01-01

    In a traditional Black–Scholes market we develop a verification theorem for a general class of investment and consumption problems where the standard dynamic programming principle does not hold. The theorem is an extension of the standard Hamilton–Jacobi–Bellman equation in the form of a system...... of non-linear differential equations. We derive the optimal investment and consumption strategy for a mean-variance investor without pre-commitment endowed with labor income. In the case of constant risk aversion it turns out that the optimal amount of money to invest in stocks is independent of wealth...... of future labor income net of consumption. Using the verification theorem we give a detailed analysis of this problem. It turns out that the optimal amount of money to invest in stocks is given by a linear function of wealth plus the financial value of future labor income net of consumption. The optimal...

  8. Allocation Problems and Market Design

    DEFF Research Database (Denmark)

    Smilgins, Aleksandrs

    The thesis contains six independent papers with a common theme: Allocation problems and market design. The first paper is concerned with fair allocation of risk capital where independent autonomous subunits have risky activities and together constitute the entity's total risk, whose associated risk...... with fractional players to allocate the common cost in an entity to the finite number of outputs. The paper is concerned with the computation of Aumann-Shapley prices when the cost function is estimated as a convex hull of a set of observed data points. It is discussed how to overcome certain problems related...... to non-differentiability of the cost function and inefficiency in production. Staying within the theme of cost sharing a fourth paper analyzes a model for trading green energy in a grid where countries are characterized by stochastic demand and stochastic production. The gain is obtained by trading which...

  9. COUNTERFEIT DRUGS: PROBLEMS AND SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Khanna Surabhi

    2010-12-01

    Full Text Available The pharmaceutical industry is under extraordinary strain. Facing the wrath of consumers because of the cost of products, constantly answering the questions of state and federal legislators looking to control health care costs, and losing value in the marketplace, the industry’s hands are more than full. A less discussed but substantial problem impacts all of pharmaceutical industry’s other problems, counterfeiting. The World Health Organization estimates that counterfeit drugs make up about 10 percent of the global medicine market, and more than 25 percent in developing countries. With counterfeit drugs increasingly finding their way into global distribution chains and ultimately into patients' mouths, it is essential that pharmaceutical companies have effective enforcement strategies to combat the manufacture and distribution of counterfeit drugs.

  10. An archetype hydrogen atmosphere problem

    Science.gov (United States)

    Athay, R. G.; Mihalas, D.; Shine, R. A.

    1975-01-01

    Populations for the first three bound states and the continuum of hydrogen are determined for an isothermal hydrostatic atmosphere at 20,000 K. The atmosphere is treated as optically thin in the Balmer and Paschen continua and illuminated by continuum radiation at these wavelengths with prescribed radiation temperatures. The atmosphere is optically thick in the 2-1, 3-1, 3-2 and c-1 transitions. Three stages of approximation are treated: (1) radiative detailed balance in the 2-1, 3-1 and 3-2 transitions, (2) radiative detailed balance in the 3-1 and 3-2 transitions, and (3) all transitions out of detailed balance. The solution of this problem is nontrivial and presents sufficient difficulty to have caused the failure of at least one rather standard technique. The problem is thus a good archetype against which new methods or new implementations of old methods may be tested.

  11. Networks in social policy problems

    CERN Document Server

    Scotti, marco

    2012-01-01

    Network science is the key to managing social communities, designing the structure of efficient organizations and planning for sustainable development. This book applies network science to contemporary social policy problems. In the first part, tools of diffusion and team design are deployed to challenges in adoption of ideas and the management of creativity. Ideas, unlike information, are generated and adopted in networks of personal ties. Chapters in the second part tackle problems of power and malfeasance in political and business organizations, where mechanisms in accessing and controlling informal networks often outweigh formal processes. The third part uses ideas from biology and physics to understand global economic and financial crises, ecological depletion and challenges to energy security. Ideal for researchers and policy makers involved in social network analysis, business strategy and economic policy, it deals with issues ranging from what makes public advisories effective to how networks influenc...

  12. Decision Problems For Convex Languages

    CERN Document Server

    Brzozowski, Janusz; Xu, Zhi

    2008-01-01

    In this paper we examine decision problems associated with various classes of convex languages, studied by Ang and Brzozowski (under the name "continuous languages''). We show that we can decide whether a given language L is prefix-, suffix-, factor-, or subword-convex in polynomial time if L is represented by a DFA, but that the problem is PSPACE-hard if L is represented by an NFA. In the case that a regular language is not convex, we prove tight upper bounds on the length of the shortest words demonstrating this fact, in terms of the number of states of an accepting DFA. Similar results are proved for some subclasses of convex languages: the prefix-, suffix-, factor-, and subword-closed languages, and the prefix-, suffix-, factor-, and subword-free languages.

  13. Complex analogues of real problems

    DEFF Research Database (Denmark)

    Esdahl-Schou, Rune

    This thesis will be a mix of different problems in number theory. As such it is split into two natural parts. The rst part focuses on normal numbers and construction of numbers that are normal to a given complex base. It is written in the style of a thorough and introductory paper on that subject...... and Tichy in [Madritsch et al., 2008] and [Madritsch, 2008] and contains a generalisation of the main theorem in [Madritsch, 2008]. The second part of the thesis focuses on Diophantine approximation, mainly on a famous conjecture by Schmidt from the 1980s. This conjecture was solved by Badziahin, Pollington...... and Velani, and inspired by this An gave a different proof which provides a stronger result. The conjecture is concerned with intersections of certain sets in the plane and are as such a real problem. We will consider a slightly different setup where the real plane is replaced by the complex plane. Using...

  14. On the tumbling toast problem

    Science.gov (United States)

    Borghi, Riccardo

    2012-09-01

    A didactical revisitation of the so-called tumbling toast problem is presented here. The numerical solution of the related Newton's equations has been found in the space domain, without resorting to the complete time-based law of motion, with a considerable reduction of the mathematical complexity of the problem. This could allow the effect of the different physical mechanisms ruling the overall dynamics to be appreciated in a more transparent way, even by undergraduates. Moreover, the availability from the literature of experimental investigations carried out on tumbling toast allows us to propose different theoretical models of growing complexity in order to show the corresponding improvement of the agreement between theory and observation.

  15. Numerical models for differential problems

    CERN Document Server

    Quarteroni, Alfio

    2014-01-01

    In this text, we introduce the basic concepts for the numerical modelling of partial differential equations. We consider the classical elliptic, parabolic and hyperbolic linear equations, but also the diffusion, transport, and Navier-Stokes equations, as well as equations representing conservation laws, saddle-point problems and optimal control problems. Furthermore, we provide numerous physical examples which underline such equations. We then analyze numerical solution methods based on finite elements, finite differences, finite volumes, spectral methods and domain decomposition methods, and reduced basis methods. In particular, we discuss the algorithmic and computer implementation aspects and provide a number of easy-to-use programs. The text does not require any previous advanced mathematical knowledge of partial differential equations: the absolutely essential concepts are reported in a preliminary chapter. It is therefore suitable for students of bachelor and master courses in scientific disciplines, an...

  16. Tsirelson's problem and Kirchberg's conjecture

    CERN Document Server

    Fritz, Tobias

    2010-01-01

    Tsirelson's problem asks whether the set of nonlocal quantum correlations with a tensor product structure for the Hilbert space of states coincides with the one where only commutativity between observables located at different sites is assumed. Here it is shown that Kirchberg's QWEP conjecture on C*-algebras implies a positive answer to this question for all bipartite scenarios. The main idea is very simple and consists of relabelling measurement outcomes by complex roots of unity, so that a k-ary observable becomes a unitary of order k. This relates Tsirelson's problem to tensor products of certain group C^*-algebras to which Kirchberg's conjecture applies. For related work, see the simultaneously appearing preprint by Junge et al.

  17. Retrofitting and the mu Problem

    Energy Technology Data Exchange (ETDEWEB)

    Green, Daniel; Weigand, Timo; /SLAC /Stanford U., Phys. Dept.

    2010-08-26

    One of the challenges of supersymmetry (SUSY) breaking and mediation is generating a {mu} term consistent with the requirements of electro-weak symmetry breaking. The most common approach to the problem is to generate the {mu} term through a SUSY breaking F-term. Often these models produce unacceptably large B{mu} terms as a result. We will present an alternate approach, where the {mu} term is generated directly by non-perturtative effects. The same non-perturbative effect will also retrofit the model of SUSY breaking in such a way that {mu} is at the same scale as masses of the Standard Model superpartners. Because the {mu} term is not directly generated by SUSY breaking effects, there is no associated B{mu} problem. These results are demonstrated in a toy model where a stringy instanton generates {mu}.

  18. Variational principles in instanton problems

    Energy Technology Data Exchange (ETDEWEB)

    D' yakonov, D.I.; Petrov, V.Yu. (AN SSSR, Leningrad. Inst. Yadernoj Fiziki)

    1984-01-01

    The authors suggest a simple approximate method of evaluating path integrals for problems in which subbarrier transitions (instantons) play an important role. This method, based on Feyman's variational principle, is a generalization of the semi-classical approximation. When there is a quasiclassical parameter in a problem, the method is reduced to approximate calculations of Gauss' functional integrals (i.e. functional determinants). The authors derive general formulas for such integrals, which prove to be valid for a broad class of potentials, and verify the accuracy of the approximation using the examples of double-well and periodic potentials. In both cases the accuracy in determining the level splitting proves to be within several percent.

  19. Stochastic problems in population genetics

    CERN Document Server

    Maruyama, Takeo

    1977-01-01

    These are" notes based on courses in Theoretical Population Genetics given at the University of Texas at Houston during the winter quarter, 1974, and at the University of Wisconsin during the fall semester, 1976. These notes explore problems of population genetics and evolution involving stochastic processes. Biological models and various mathematical techniques are discussed. Special emphasis is given to the diffusion method and an attempt is made to emphasize the underlying unity of various problems based on the Kolmogorov backward equation. A particular effort was made to make the subject accessible to biology students who are not familiar with stochastic processes. The references are not exhaustive but were chosen to provide a starting point for the reader interested in pursuing the subject further. Acknowledgement I would like to use this opportunity to express my thanks to Drs. J. F. Crow, M. Nei and W. J. Schull for their hospitality during my stays at their universities. I am indebted to Dr. M. Kimura...

  20. Fibonacci's Triangle: A Vehicle for Problem Solving.

    Science.gov (United States)

    Ouellette, Hugh

    1979-01-01

    A method for solving certain types of problems is illustrated by problems related to Fibonacci's triangle. The method involves pattern recognition, generalizing, algebraic manipulation, and mathematical induction. (MP)

  1. Sociale problemer og sociale afvigelser - sociologisk set

    DEFF Research Database (Denmark)

    Henriksen, Lars Skov

    2002-01-01

    The arcticle presents central classical sociological theories of social problems and social deviance.......The arcticle presents central classical sociological theories of social problems and social deviance....

  2. Problems of an epic historicism

    OpenAIRE

    Sozashvili, N.

    2012-01-01

    Explanation of mutual relations between separate genres and intragenre versions special interest is got with problems of an epic historicism to which in the newest scientific literature hardly paid the attention. The typology of an epic historicism is simultaneously typology of epic genres, typology of development of epic creativity. The historicism cannot be isolated from art system; it makes one of its organic qualities. The knowledge of topology and the general laws of epic creativity open...

  3. Evolution Strategies in Optimization Problems

    CERN Document Server

    Cruz, Pedro A F

    2007-01-01

    Evolution Strategies are inspired in biology and part of a larger research field known as Evolutionary Algorithms. Those strategies perform a random search in the space of admissible functions, aiming to optimize some given objective function. We show that simple evolution strategies are a useful tool in optimal control, permitting to obtain, in an efficient way, good approximations to the solutions of some recent and challenging optimal control problems.

  4. Security Problems in Cloud Computing

    OpenAIRE

    Rola Motawie; Mahmoud M. El-Khouly; Samir Abou El-Seoud

    2016-01-01

    Cloud is a pool of computing resources which are distributed among cloud users. Cloud computing has many benefits like scalability, flexibility, cost savings, reliability, maintenance and mobile accessibility. Since cloud-computing technology is growing day by day, it comes with many security problems. Securing the data in the cloud environment is most critical challenges which act as a barrier when implementing the cloud. There are many new concepts that cloud introduces, such as resource sh...

  5. Uranium Critical Point Location Problem

    CERN Document Server

    Iosilevskiy, Igor

    2013-01-01

    Significant uncertainty of our present knowledge for uranium critical point parameters is under consideration. Present paper is devoted to comparative analysis of possible resolutions for the problem of uranium critical point location, as well as to discussion of plausible scheme of decisive experiment, which could resolve existing uncertainty. New calculations of gas-liquid coexistence in uranium by modern thermodynamic code are included in the analysis.

  6. Graphical Models for Bandit Problems

    CERN Document Server

    Amin, Kareem; Syed, Umar

    2012-01-01

    We introduce a rich class of graphical models for multi-armed bandit problems that permit both the state or context space and the action space to be very large, yet succinctly specify the payoffs for any context-action pair. Our main result is an algorithm for such models whose regret is bounded by the number of parameters and whose running time depends only on the treewidth of the graph substructure induced by the action space.

  7. Dynamical problem of micropolar viscoelasticity

    Indian Academy of Sciences (India)

    Rajneesh Kumar; Suman Choudhary

    2001-09-01

    The dynamic problem in micropolar viscoelastic medium has been investigated by employing eigen value approach after applying Laplace and Fourier transformations. An example of infinite space with concentrated force at the origin has been presented to illustrate the application of the approach. The integral transforms have been inverted by using a numerical technique to obtain the displacement components, force stresses, couple stress and microrotation in the physical domain. The results for these quantities are given and illustrated graphically.

  8. Characteristics and Problems of CLT

    Institute of Scientific and Technical Information of China (English)

    张利梅

    2009-01-01

    The present paper makes a short introduction about 8 kinds of teaching approaches and methods, later with a focus on the approach of Communicative Language Teaching (CLT).This paper first summarizes the charactertistics of CLT, and after that gives the existing problems of CLT, and in the end a conclusion is made. The purpose of this paper is to make a clearonderstanding of CLT in order to provide some advice to out it.

  9. Cognitive Agents and Learning Problems

    Directory of Open Access Journals (Sweden)

    Goran Zaharija

    2017-03-01

    Full Text Available Goals, Operators, Methods, and Selection rules (GOMS model is a widely recognised concept in Human-Computer Interaction (HCI. Since the initial idea, several GOMS techniques were developed that were used for analysis, differing in their form defined by the logical structure and prediction power. Through defined operators and methods and following the certain rules, the user can reach a specific goal. This work represents an effort to apply GOMS method in the field of artificial intelligence, specifically on a state-space search problems. Card, Morgan, Newman GOMS (CMNGOMS model has been chosen, since it represents ground-floor of the GOMS idea that solves the given task through a sequence of operators. Compared with the informed search algorithms for solving the given task, CMN-GOMS model gave better results. Moreover, it was shown that this model could be used in any other space motion problem in the natural environment. LEGO® MINDSTORMS® EV3 robot was used to demonstrate the application of GOMS model in real world pathfinding problems and as a test-bed for comparing proposed model with well-known search algorithms.

  10. Solving the Wrong Hierarchy Problem

    CERN Document Server

    Blinov, Nikita

    2016-01-01

    Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and $\\mathbb{Z}_2$-symmetric theories where the Standard Model Higgs potential has two vacua. The parity or $\\mathbb{Z}_2$ copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to the Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop thi...

  11. Undecidable Problems About Timed Automata

    CERN Document Server

    Finkel, Olivier

    2007-01-01

    We solve some decision problems for timed automata which were recently raised by S. Tripakis in [ Folk Theorems on the Determinization and Minimization of Timed Automata, in the Proceedings of the International Workshop FORMATS'2003, LNCS, Volume 2791, p. 182-188, 2004 ] and by E. Asarin in [ Challenges in Timed Languages, From Applied Theory to Basic Theory, Bulletin of the EATCS, Volume 83, p. 106-120, 2004 ]. In particular, we show that one cannot decide whether a given timed automaton is determinizable or whether the complement of a timed regular language is timed regular. We show that the problem of the minimization of the number of clocks of a timed automaton is undecidable. It is also undecidable whether the shuffle of two timed regular languages is timed regular. We show that in the case of timed B\\"uchi automata accepting infinite timed words some of these problems are Pi^1_1-hard, hence highly undecidable (located beyond the arithmetical hierarchy).

  12. Elementary Investigation of Transportation Problems

    Directory of Open Access Journals (Sweden)

    Edit Schmidt

    2009-07-01

    Full Text Available For students learning the simplex method of linear programming it is a wellbelovedoccasion to solve the so-called transportation problem by the method ofdistribution. This method is simple to calculate and easy to follow. The simple way ofsolution suggests that its correctness may be proven by basic means. This paper has twomain aims. One of them is to present the problem and to solve it by basic means. The otherone is the analysis of the so-called array-bases defined for this reason. In case of atransportation problem m stores and n destinations are given, and the goods have to betaken from the stores to the destinations such that the cost of transporting has to beminimal. The unit costs of the transportation are given by an array. In the solution someroutes (elements of the array are chosen and the number of units to transport there isgiven. It will be proven that the routes for the optimal transportation compose a basis, andthe solution is also achieved by those through the searches. (The basis of an m n × arrayconsists of m+n−1 elements such that they do not span a loop. In the proof somecharacteristics of the bases are needed, for example that the number of them is finite. Toprove this it is enough to give an easily calculated upper bound, the exact value is given inthe appendix. As an extra result of this calculation some interesting formulas ofcombinatorics are also proven.

  13. Problems with plastered external heat insulation. Probleme mit verputzter Aussenwaermedaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Epple, H.; Foglia, A.; Preisig, H.; Pfefferkorn, J.

    1984-01-01

    Concerning execution, maintenance and service life, walls with plastered external heat insulation constitute an economic method. Owing to experience gained with plastered external heat insulation, it is possible today to provide reliable information on requirements made on ground material and operational execution. The author intends to contribute to a prevention of defects by giving concise examples. A survey on different types of external heat insulation is followed by a treatment of the problem areas of roof-edge connection, base end under ground, modernization of old buildings and cracks in plaster. Principal statements are made concerning steam diffusion, planning, materials and execution.

  14. Authentication: A Standard Problem or a Problem of Standards?

    Directory of Open Access Journals (Sweden)

    Amanda Capes-Davis

    2016-06-01

    Full Text Available Reproducibility and transparency in biomedical sciences have been called into question, and scientists have been found wanting as a result. Putting aside deliberate fraud, there is evidence that a major contributor to lack of reproducibility is insufficient quality assurance of reagents used in preclinical research. Cell lines are widely used in biomedical research to understand fundamental biological processes and disease states, yet most researchers do not perform a simple, affordable test to authenticate these key resources. Here, we provide a synopsis of the problems we face and how standards can contribute to an achievable solution.

  15. Hybrid tractability of soft constraint problems

    CERN Document Server

    Cooper, Martin C

    2010-01-01

    The constraint satisfaction problem (CSP) is a central generic problem in computer science and artificial intelligence: it provides a common framework for many theoretical problems as well as for many real-life applications. Soft constraint problems are a generalisation of the CSP which allow the user to model optimisation problems. Considerable effort has been made in identifying properties which ensure tractability in such problems. In this work, we initiate the study of hybrid tractability of soft constraint problems; that is, properties which guarantee tractability of the given soft constraint problem, but which do not depend only on the underlying structure of the instance (such as being tree-structured) or only on the types of soft constraints in the instance (such as submodularity). We present several novel hybrid classes of soft constraint problems, which include a machine scheduling problem, constraint problems of arbitrary arities with no overlapping nogoods, and the SoftAllDiff constraint with arbi...

  16. Learning from the problems of problem-based learning

    Directory of Open Access Journals (Sweden)

    Epstein Richard

    2004-01-01

    Full Text Available Abstract Background The last decade has witnessed a rapid expansion of biomedical knowledge. Despite this, fashions in medical education over the same period have shifted away from factual (didactic teaching and towards contextual, or problem-based, learning (PBL. This paradigm shift has been justified by studies showing that PBL improves reasoning and communication while being associated with few if any detectable knowledge deficits. Discussion Analysis of the literature indicates that the recent rapid rise of PBL has closely paralleled the timing of the information explosion. The growing dominance of PBL could thus worsen the problems of information management in medical education via several mechanisms: first, by creating the impression that a defined spectrum of core factual knowledge suffices for clinical competence despite ongoing knowledge expansion (quality cost; second, by dissuading teachers from refining the educational utility of didactic modalities (improvement cost; and third, by reducing faculty time for developing reusable resources to impart factual knowledge more efficiently (opportunity cost. Summary These costs of PBL imply a need for strengthening the knowledge base of 21st-century medical graduates. New initiatives towards this end could include the development of more integrated cognitive techniques for facilitating the comprehension of complex data; the design of differentiated medical curricula for producing graduates with defined high-priority skill sets; and the encouragement of more cost-effective faculty teaching activities focused on the prototyping and testing of innovative commercializable educational tools.

  17. Effects of problem characteristics, capturing problem structure and using analogies on high school students’ success on problem-solving

    OpenAIRE

    Pedro GARCÍA GALLEGO; Sanjosé López, Vicente; SOLAZ-PORTOLÉS, Joan Josep

    2015-01-01

    This study analyses the influence of academic level, academic itinerary, word problem’s context and structure, capturing problem structure, and using analogies on problem-solving. A factorial design was used with one within-subjects variable and several between-subjects variables, which have been selected depending on the hypothesis in question. Two types of booklets containing two word problems and questions about capturing problem structure and using analogies in problem solving, were admin...

  18. Genetics problem solving and worldview

    Science.gov (United States)

    Dale, Esther

    The research goal was to determine whether worldview relates to traditional and real-world genetics problem solving. Traditionally, scientific literacy emphasized content knowledge alone because it was sufficient to solve traditional problems. The contemporary definition of scientific literacy is, "The knowledge and understanding of scientific concepts and processes required for personal decision-making, participation in civic and cultural affairs and economic productivity" (NRC, 1996). An expanded definition of scientific literacy is needed to solve socioscientific issues (SSI), complex social issues with conceptual, procedural, or technological associations with science. Teaching content knowledge alone assumes that students will find the scientific explanation of a phenomenon to be superior to a non-science explanation. Formal science and everyday ways of thinking about science are two different cultures (Palmer, 1999). Students address this rift with cognitive apartheid, the boxing away of science knowledge from other types of knowledge (Jedege & Aikenhead, 1999). By addressing worldview, cognitive apartheid may decrease and scientific literacy may increase. Introductory biology students at the University of Minnesota during fall semester 2005 completed a written questionnaire-including a genetics content-knowledge test, four genetic dilemmas, the Worldview Assessment Instrument (WAI) and some items about demographics and religiosity. Six students responded to the interview protocol. Based on statistical analysis and interview data, this study concluded the following: (1) Worldview, in the form of metaphysics, relates to solving traditional genetic dilemmas. (2) Worldview, in the form of agency, relates to solving traditional genetics problems. (3) Thus, worldview must be addressed in curriculum, instruction, and assessment.

  19. The hard problem of cooperation.

    Directory of Open Access Journals (Sweden)

    Kimmo Eriksson

    Full Text Available Based on individual variation in cooperative inclinations, we define the "hard problem of cooperation" as that of achieving high levels of cooperation in a group of non-cooperative types. Can the hard problem be solved by institutions with monitoring and sanctions? In a laboratory experiment we find that the answer is affirmative if the institution is imposed on the group but negative if development of the institution is left to the group to vote on. In the experiment, participants were divided into groups of either cooperative types or non-cooperative types depending on their behavior in a public goods game. In these homogeneous groups they repeatedly played a public goods game regulated by an institution that incorporated several of the key properties identified by Ostrom: operational rules, monitoring, rewards, punishments, and (in one condition change of rules. When change of rules was not possible and punishments were set to be high, groups of both types generally abided by operational rules demanding high contributions to the common good, and thereby achieved high levels of payoffs. Under less severe rules, both types of groups did worse but non-cooperative types did worst. Thus, non-cooperative groups profited the most from being governed by an institution demanding high contributions and employing high punishments. Nevertheless, in a condition where change of rules through voting was made possible, development of the institution in this direction was more often voted down in groups of non-cooperative types. We discuss the relevance of the hard problem and fit our results into a bigger picture of institutional and individual determinants of cooperative behavior.

  20. Man and His Technology: Problems and Issues.

    Science.gov (United States)

    Piel, E. J.; Truxal, John G.

    This book looks at a sampling of notable socio-technical problems within a rational context. It seeks to determine if problems exist with recent decisions in the application of technology; how threatening any problems may be; the source of problems; and examines alternatives available to the nation. The broad goal of this rational consideration is…

  1. CONTINUOUS DEPENDENCE FOR A BACKWARD PARABOLIC PROBLEM

    Institute of Scientific and Technical Information of China (English)

    刘继军

    2003-01-01

    We consider a backward parabolic problem arising in the description of the behavior of the toroidal part of the magenetic field in a dynamo problem. In our backward time problem, the media parameters are spatial distributed and the boundary conditions are of the Robin type. For this ill-posed problem, we prove that the solution depends continuously on the initial-time geometry.

  2. Journey toward Teaching Mathematics through Problem Solving

    Science.gov (United States)

    Sakshaug, Lynae E.; Wohlhuter, Kay A.

    2010-01-01

    Teaching mathematics through problem solving is a challenge for teachers who learned mathematics by doing exercises. How do teachers develop their own problem solving abilities as well as their abilities to teach mathematics through problem solving? A group of teachers began the journey of learning to teach through problem solving while taking a…

  3. Solving set partitioning problems using lagrangian relaxation

    NARCIS (Netherlands)

    van Krieken, M.G.C.

    2006-01-01

    This thesis focuses on the set partitioning problem. Given a collection of subsets of a certain root set and costs associated to these subsets, the set partitioning problem is the problem of finding a minimum cost partition of the root set. Many real-life problems, such as vehicle routing and crew s

  4. Problem-solving and Cognitive Style.

    Science.gov (United States)

    Garrett, Roger M.

    1989-01-01

    Reviewed are 15 studies on cognitive style and problem solving in science education. The effects of problem context, problem type, and three kinds of cognitive style on subjects' abilities to encounter and solve problems are investigated. Three protocols of the subjects' encountering activities are provided. (YP)

  5. The Duality on Vector Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    HUANG Long-guang

    2012-01-01

    Duality framework on vector optimization problems in a locally convex topological vector space are established by using scalarization with a cone-strongly increasing function.The dualities for the scalar convex composed optimization problems and for general vector optimization problems are studied.A general approach for studying duality in vector optimization problems is presented.

  6. Competition Based Neural Networks for Assignment Problems

    Institute of Scientific and Technical Information of China (English)

    李涛; LuyuanFang

    1991-01-01

    Competition based neural networks have been used to solve the generalized assignment problem and the quadratic assignment problem.Both problems are very difficult and are ε approximation complete.The neural network approach has yielded highly competitive performance and good performance for the quadratic assignment problem.These neural networks are guaranteed to produce feasible solutions.

  7. Global continuation for distance geometry problems

    Energy Technology Data Exchange (ETDEWEB)

    More, J.J.; Wu, Zhijun

    1995-03-01

    Distance geometry problems arise in the interpretation of NMR data and in the determination of protein structure. The authors formulate the distance geometry problem as a global minimization problem with special structure, and show the global smoothing techniques and a continuation approach for global optimization can be used to determine solutions of distance geometry problems with a nearly 100% probability of success.

  8. Common ground, complex problems and decision making

    NARCIS (Netherlands)

    Beers, P.J.; Boshuizen, H.P.A.; Kirschner, P.A.; Gijselaers, W.H.

    2006-01-01

    Organisations increasingly have to deal with complex problems. They often use multidisciplinary teams to cope with such problems where different team members have different perspectives on the problem, different individual knowledge and skills, and different approaches on how to solve the problem. I

  9. Toward a Design Theory of Problem Solving.

    Science.gov (United States)

    Jonassen, David H.

    2000-01-01

    Proposes a metatheory of problem solving. Describes differences among problems in terms of their structured ness, domain specificity (abstractness), and complexity; describes individual differences that affect problem solving; and presents a typology of problems, each of which engages different cognitive, affective, and conative process and…

  10. The governance of problems: puzzling, powering, participation

    NARCIS (Netherlands)

    Hoppe, Robert

    2010-01-01

    Policy analysis usually gives more attention to problem solving than problem finding and there is a real threat of mismatch between problem perceptions by citizens and problem definition by their elected and appointed policy makers. Contemporary democracies need to develop a better governance of pro

  11. Quantum three-body problems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A scheme for dealing with the quantum three-body problem is presented to separate the rotational degrees of freedom completely from the internal ones. In this method, the three-body Schridinger equation is reduced to a system of coupled partial differential equations, depending only upon three internal variables. For arbitrary total orbital angular momentum l and the parity (-1)l+λ (λ=0 or 1), the number of the equations in this system is l+1-λ. By expanding the wavefunction with respect to a complete set of orthonormal basis functions, the system of equations is further reduced to a system of linear algebraic equations.

  12. Effort problem of chemical pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Okrajni, J.; Ciesla, M.; Mutwil, K. [Silesian Technical University, Katowice (Poland)

    1998-12-31

    The problem of the technical state assessment of the chemical pipelines working under mechanical and thermal loading has been shown in the paper. The pipelines effort after the long time operating period has been analysed. Material geometrical and loading conditions of the crack initiation and crack growth process in the chosen object has been discussed. Areas of the maximal effort have been determined. The material structure charges after the long time operating period have been described. Mechanisms of the crack initiation and crack growth in the pipeline elements have been analysed and mutual relations between the chemical and mechanical influences have been shown. (orig.) 16 refs.

  13. Neurotechnology premises, potential, and problems

    CERN Document Server

    Giordano, James

    2012-01-01

    New technologies that allow us to investigate mechanisms and functions of the brain have shown considerable promise in treating brain disease and injury. These emerging technologies also provide a means to assess and manipulate human consciousness, cognitions, emotions, and behaviors, bringing with them the potential to transform society. Neurotechnology: Premises, Potential, and Problems explores the technical, moral, legal, and sociopolitical issues that arise in and from today,s applications of neuroscience and technology and discusses their implications for the future. Some of the issues r

  14. From 'troublemakers' to problem solvers

    DEFF Research Database (Denmark)

    Frandsen, Martin Severin; Pfeiffer Petersen, Lene

    2012-01-01

    This paper presents the experiences and reflexions of a design practitioner working in the field of community development. The case illustrates how participatory design processes can contribute to social change. The paper tells a story of design process where youths from a local school...... but less tangible result of the design process was the change it produced in the social relations in the neighbourhood. By giving them the opportunity to work as designers, the process contributed to a shift in the image of the youths from one of 'troublemakers' to a positive image of collaborative problem...

  15. Health problems in Turner syndrome

    Directory of Open Access Journals (Sweden)

    Mehdi Salek

    2007-06-01

    Full Text Available

    BACKGROUND: Although cardiovascular malformations are well-recognized congenital anomalies in Turner syndrome (TS, other clinical features and a great variety of dysmorphic signs can also be observed. There are few studies about different medical problems in pre-selected groups of patients with Turner syndrome. Therefore, in this study we aimed to assess the prevalence of some medical problems in Turner syndrome.

    METHODS: This was a case series from April to October 2005. We studied 40 patients with TS who attended the Endocrine and Metabolic Research Center. Audiometry, echocardiography, ultrasonography of kidneys and urinary tracts, thyroid function tests, fasting blood sugar, lipid profile as well as anthropometric and blood pressure measurements were assessed in all patients and collected data were analyzed by SPSS version 10.

    RESULTS: Of the 40 subjects 62.5% (n = 25 had cardiac anomalies, 20% (n = 8 had high blood pressure, about 60% (n = 24 suffered from hearing loss and 15% (n = 6 suffered from duplication or dilatation of urinary collecting system. The relative frequency of hypothyroidism, hypercholesterolemia and hypertriglyceridemia was 25% (n = 10, 30% (n = 12 and 32.5% (n = 13, respectively.

    CONCLUSIONS: Medical problems are common in TS patients and the routine screening of their health conditions should be performed at the time of diagnosis and at

  16. Solving complex problems a handbook

    CERN Document Server

    Schönwandt, Walter; Grunau, Jens; Utz, Jürgen; Voermanek, Katrin

    2014-01-01

    When you're planning something big, problems appear rather quickly. We hear of them on a daily basis. The bigger or more complex a task, the more we have to deal with complicated, multidisciplinary task formulations. In many cases it is architecture, including urban and spatial planning, but also politics and all types of organizational forms, irrespective of whether they are public authorities or private enterprises, which are expected to deliver functional solutions for such challenges. This is precisely where this book is helpful. It introduces a methodology for developing target-specific,

  17. SOME PROBLEMS ABOUT SHIP WAVES

    Institute of Scientific and Technical Information of China (English)

    Liu Min-jia

    2003-01-01

    Several problems about ship waves were discussed in the dissertation:(1) Transient ship waves from calmness to the generation of steady-state ship waves were described. (2) The procedure of the formation of the V-shaped steady-state ship waves were clearly shown, and the difference of ship waves on an inviscid fluid and on a viscous fluid was exmined. (3) With the Lighthill two-stage scheme, the algebraic expression for ship waves on a viscous fluid of finite depth was obtained.(4) Singularity on the two boundaries of the ship waves was treated.

  18. The Vessel Schedule Recovery Problem

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Plum, Christian Edinger Munk; Vaaben, Bo;

    Maritime transportation is the backbone of world trade and is accountable for around 3% of the worlds CO2 emissions. We present the Vessel Schedule Recovery Problem (VSRP) to evaluate a given disruption scenario and to select a recovery action balancing the trade off between increased bunker cons...... consumption and the impact on the remaining network and the customer service level. The model is applied to 4 real cases from Maersk Line. Solutions are comparable or superior to those chosen by operations managers. Cost savings of up to 58% may be achieved....

  19. Silverlight 4 Problem - Design - Solution

    CERN Document Server

    Lecrenski, Nick

    2010-01-01

    A hands-on guide to Microsoft's latest rich application development technology: Silverlight 4. Silverlight 4 is the newest version of the rich Internet application toolkit that provides support for .NET capabilities over the Internet. With this latest release of Silverlight, Microsoft has revolutionized the way that Web applications can be created. This book uses the popular Problem – Design – Solution strategy to demonstrate how to harness the power and abilities of Silverlight 4 to add value to the overall user experience of a Web site. Using a Web site created by the author as a reference p

  20. SCHOOL VIOLENCE: A COMPLEX PROBLEM

    Directory of Open Access Journals (Sweden)

    María del Rosario Ayala-Carrillo

    2015-07-01

    Full Text Available School violence is one type of violence that reflects the breakdown of current society. It is impossible to speak of school violence as an isolated phenomenon without establishing nexuses between public and private life, between collective and individual behaviors, between family and community aspects, without making reference to differences in gender and the life stories of those who are the aggressors or the victims, and without considering the patriarchal culture and interpersonal relationships. When all these factor are interrelated, they make the problem of violence a very complex one that requires us to know the different factors in order to understand it and deal with it.

  1. Problems in Sociology of Sports

    OpenAIRE

    2011-01-01

    El presente artículo es una apuesta por reconstruir, articular y problematizar los aportes y los avances de investigación en torno a los estudios sociales del deporte y el tiempo libre, puestos en discusiones en el marco de la mesa de trabajo sobre problemáticas de la sociología del deporte, llevada a cabo durante el 9º Congreso Argentino y 4º Latinoamericano de Educación Física y Ciencias. La lectura holística e integral de las diferentes producciones académicas, y los diálogos que de ellas ...

  2. Mobile authentication problems and solutions

    CERN Document Server

    Jakobsson, Markus

    2012-01-01

    Mobile Authentication: Problems and Solutions looks at human-to-machine authentication, with a keen focus on the mobile scenario. Human-to-machine authentication is a startlingly complex issue. In the old days of computer security-before 2000, the human component was all but disregarded. It was either assumed that people should and would be able to follow instructions, or that end users were hopeless and would always make mistakes. The truth, of course, is somewhere in between, which is exactly what makes this topic so enticing. We cannot make progress with human-to-machine authentication with

  3. The Black Hole Information Problem

    CERN Document Server

    Polchinski, Joseph

    2016-01-01

    The black hole information problem has been a challenge since Hawking's original 1975 paper. It led to the discovery of AdS/CFT, which gave a partial resolution of the paradox. However, recent developments, in particular the firewall puzzle, show that there is much that we do not understand. I review the black hole, Hawking radiation, and the Page curve, and the classic form of the paradox. I discuss AdS/CFT as a partial resolution. I then discuss black hole complementarity and its limitations, leading to many proposals for different kinds of `drama.' I conclude with some recent ideas.

  4. Applied Mathematical Problems in Engineering

    Directory of Open Access Journals (Sweden)

    Carlos Llopis-Albert

    2016-10-01

    Full Text Available There is a close relationship between engineering and mathematics, which has led to the development of new techniques in recent years. Likewise the developments in technology and computers have led to new ways of teaching mathematics for engineering students and the use of modern techniques and methods.  This research aims to provide insight on how to deal with mathematical problems for engineering students. This is performed by means of a fuzzy set/Qualitative Comparative Analysis applied to conflict resolution of Public Participation Projects in support to the EU Water Framework Directive.

  5. Fast Food Problems and Responsibilities

    Institute of Scientific and Technical Information of China (English)

    Zhang; Jing

    2015-01-01

    <正>People are living in a world that acquires almost everyone to chase efficiency and speed.The real inner quality of daily life is not approximately taken into people’s consideration.Fast food is one of the common model reactions of this rapid developing society.Recently,it’s getting popular that people would rather have fast food to save time for other extra work.Problems and public concern are following that kind of life condition and someone or something should be put blame on for this.

  6. Quantum three-body problems

    Institute of Scientific and Technical Information of China (English)

    马中骐

    2000-01-01

    A scheme for dealing with the quantum three-body problem is presented to separate the rotational degrees of freedom completely from the internal ones. In this method, the three-body Schrodinger equation is reduced to a system of coupled partial differential equations, depending only upon three internal variables. For arbitrary total orbital angular momentum l and the parity ( - 1)1+ λ (λ = 0 or 1), the number of the equations in this system is l + 1 - λ . By expanding the wavef unction with respect to a complete set of orthonormal basis functions, the system of equations is further reduced to a system of linear algebraic equations.

  7. Famous Problems and Their Mathematicians

    CERN Document Server

    Johnson, Art

    1999-01-01

    Why did ordering an omelet cost one mathematician his life? Answers to this and other questions are found in this exciting new resource that shows your students how 60 mathematicians discovered mathematical solutions through everyday situations. These lessons are easily incorporated into the present curriculum as an introduction to a math concept, a homework piece, or an extra challenge. Teacher notes and suggestions for the classroom are followed by extension problems and additional background material. This is a great way to spark student interest in math. Grades 5-12.

  8. Problemes i aplicacions de Microeconomia

    OpenAIRE

    Huguet Roig, Ana; Sánchez Moreno, Manuel

    2014-01-01

    Aquest material ha rebut un dels incentius de la convocatoria 2014 per a la qualitat en l'elaboració de materials docents del Servei de Política Lingüística de la Universitat de Valencia. Problemes i aplicacions de l'assignatura "Microeconomia" dins dels estudis de grau en Admnistració i Direcció d'Empreses. Temari: 1)Producció i costos. 2)Mercats competitius.3)El monopoli. 4)La fixació dels preus amb poder de mercat. 5)La competència monopolista i l'oligopoli. Notes of Practice of the ...

  9. Nonlinear elliptic-parabolic problems

    CERN Document Server

    Kim, Inwon C

    2012-01-01

    We introduce a notion of viscosity solutions for a general class of elliptic-parabolic phase transition problems. These include the Richards equation, which is a classical model in filtration theory. Existence and uniqueness results are proved via the comparison principle. In particular, we show existence and stability properties of maximal and minimal viscosity solutions for a general class of initial data. These results are new even in the linear case, where we also show that viscosity solutions coincide with the regular weak solutions introduced in [Alt&Luckhaus 1983].

  10. On some nonlinear potential problems

    Directory of Open Access Journals (Sweden)

    M. A. Efendiev

    1999-05-01

    Full Text Available The degree theory of mappings is applied to a two-dimensional semilinear elliptic problem with the Laplacian as principal part subject to a nonlinear boundary condition of Robin type. Under some growth conditions we obtain existence. The analysis is based on an equivalent coupled system of domain--boundary variational equations whose principal parts are the Dirichlet bilinear form in the domain and the single layer potential bilinear form on the boundary, respectively. This system consists of a monotone and a compact part. Additional monotonicity implies convergence of an appropriate Richardson iteration.

  11. Fuel cells problems and solutions

    CERN Document Server

    Bagotsky, Vladimir S

    2012-01-01

    The comprehensive, accessible introduction to fuel cells, their applications, and the challenges they pose Fuel cells-electrochemical energy devices that produce electricity and heat-present a significant opportunity for cleaner, easier, and more practical energy. However, the excitement over fuel cells within the research community has led to such rapid innovation and development that it can be difficult for those not intimately familiar with the science involved to figure out exactly how this new technology can be used. Fuel Cells: Problems and Solutions, Second Edition addresses this i

  12. An optimal hostage rescue problem

    OpenAIRE

    Shi, Fengbo

    2000-01-01

    We propose the following mathematical model of optinal reacue problems concerning hostage.Suppose i persons are taken as hostages at any given point in time t,and we have to make a decision on attempting either rescue or no resuce. Let p be the probability of a hostage being killed in a rescue attempt,and let s be the probability of criminal(s) surrendering up to the following point in time if no rescue attempt is made.Futher,let g and r be the probabilities of a hostage being,respectively,ki...

  13. [Current problems in medical entomology].

    Science.gov (United States)

    Alekseev, A N

    1999-01-01

    The major problems facing medical entomology as a science and practical health care facilities in the Russian Federations allows to outline the tasks to be solved in order of their priority and significance. These include the study and monitoring of tick-borne infections, resurrecting malaria, gnat-induced diseases, acariases, allergosis and pediculosis. It is emphasized that medical entomology as a science cannot develop since the man-made changes of the environment and the predicted global warming of the Earth climate are not taken into account. The present status of medical entomological service is considered to be poor. Governmental support is required.

  14. Solving the Telomere Replication Problem

    Science.gov (United States)

    Maestroni, Laetitia; Matmati, Samah; Coulon, Stéphane

    2017-01-01

    Telomeres are complex nucleoprotein structures that protect the extremities of linear chromosomes. Telomere replication is a major challenge because many obstacles to the progression of the replication fork are concentrated at the ends of the chromosomes. This is known as the telomere replication problem. In this article, different and new aspects of telomere replication, that can threaten the integrity of telomeres, will be reviewed. In particular, we will focus on the functions of shelterin and the replisome for the preservation of telomere integrity. PMID:28146113

  15. Astronomical problems an introductory course in astronomy

    CERN Document Server

    Vorontsov-Vel'Yaminov, B A

    1969-01-01

    Astronomical Problems: An Introductory Course in Astronomy covers astronomical problems, together with a summary of the theory and the formula to be exercised. The book discusses the types of problems solved with the help of the celestial globe and how to solve astronomical problems. The text tackles problems on interpolation, the celestial sphere, systems of celestial coordinates, and culmination. Problems about the rising and setting of a heavenly body, precession, planetary movement, and parallax and aberration are also considered. The book presents problems about refraction, the apparent m

  16. Problem of Time: Facets and Machian Strategy

    CERN Document Server

    Anderson, Edward

    2013-01-01

    The Problem of Time in Quantum Gravity is that `time' in GR and `time' in ordinary quantum theory are mutually incompatible notions, which is problematic in trying to put these two theories together to form a theory of Quantum Gravity. It has 8 facets, of which I reconceptualize and re-name the following. The Frozen Formalism Problem as Temporal Relationalism, the Thin Sandwich Problem as Configurational Relationalism via Best Matching, the Problem of Observables as the Problem of Beables, the Functional Evolution Problem as the Constraint Closure Problem, and I point out multiplicity of the Global and Multiple-Choice Problems of Time. This article contains a local resolution to the Problem of Time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical and combined semiclassical-histories-records. The current frontiers of this program toward resolution of the Problem o...

  17. Problem-elephant translocation: translocating the problem and the elephant?

    Directory of Open Access Journals (Sweden)

    Prithiviraj Fernando

    Full Text Available Human-elephant conflict (HEC threatens the survival of endangered Asian elephants (Elephas maximus. Translocating "problem-elephants" is an important HEC mitigation and elephant conservation strategy across elephant range, with hundreds translocated annually. In the first comprehensive assessment of elephant translocation, we monitored 16 translocations in Sri Lanka with GPS collars. All translocated elephants were released into national parks. Two were killed within the parks where they were released, while all the others left those parks. Translocated elephants showed variable responses: "homers" returned to the capture site, "wanderers" ranged widely, and "settlers" established home ranges in new areas soon after release. Translocation caused wider propagation and intensification of HEC, and increased elephant mortality. We conclude that translocation defeats both HEC mitigation and elephant conservation goals.

  18. [Clinical problems in medical mycology: problem number 45].

    Science.gov (United States)

    Santiso, Gabriela; Arechavala, Alicia; Maiolo, Elena; Balarezo Juncos, Silvia; Fernández, Marisa Liliana; Messina, Fernando; Bianchi, Mario; Negroni, Ricardo

    2013-01-03

    A 43 year-old diabetic woman, who suffered chronic cough and brown expectoration, is presented in this clinical problem. X-ray exam and CT thorax scan showed a cavitary lung lesion, located at the upper field of the left lung. This lesion had 5 cm in diameter, with a thick wall and a spherical shadow inside. The diagnosis of chronic cavitary pulmonary coccidioidomycosis was based on the isolation of Coccidioides sp. from cultures of expectoration and bronchoalveolar lavage, and the detection of specific antibodies in immunodiffusion test and counterimmunoelectrophoresis with coccidiodin. Her diabetes was not well controlled. She was treated with intravenous amphotericin B and oral itraconazole, with good clinical response; after four months of treatment the patient abandoned clinical controls. We suppose that the patient presented a coccidioidal fungus ball, inside a chronic cavitary lesion due to pulmonary coccidiodomycosis. She came from an endemic zone of coccidioidomycosis in the Northwest of the Argentine Republic (Catamarca Province).

  19. Problem-elephant translocation: translocating the problem and the elephant?

    Science.gov (United States)

    Fernando, Prithiviraj; Leimgruber, Peter; Prasad, Tharaka; Pastorini, Jennifer

    2012-01-01

    Human-elephant conflict (HEC) threatens the survival of endangered Asian elephants (Elephas maximus). Translocating "problem-elephants" is an important HEC mitigation and elephant conservation strategy across elephant range, with hundreds translocated annually. In the first comprehensive assessment of elephant translocation, we monitored 16 translocations in Sri Lanka with GPS collars. All translocated elephants were released into national parks. Two were killed within the parks where they were released, while all the others left those parks. Translocated elephants showed variable responses: "homers" returned to the capture site, "wanderers" ranged widely, and "settlers" established home ranges in new areas soon after release. Translocation caused wider propagation and intensification of HEC, and increased elephant mortality. We conclude that translocation defeats both HEC mitigation and elephant conservation goals.

  20. The inverse maximum dynamic flow problem

    Institute of Scientific and Technical Information of China (English)

    BAGHERIAN; Mehri

    2010-01-01

    We consider the inverse maximum dynamic flow (IMDF) problem.IMDF problem can be described as: how to change the capacity vector of a dynamic network as little as possible so that a given feasible dynamic flow becomes a maximum dynamic flow.After discussing some characteristics of this problem,it is converted to a constrained minimum dynamic cut problem.Then an efficient algorithm which uses two maximum dynamic flow algorithms is proposed to solve the problem.

  1. Solving the factorization problem with P systems

    Institute of Scientific and Technical Information of China (English)

    Alberto Leporati; Claudio Zandron; Giancarlo Mauri

    2007-01-01

    P systems have been used many times to face with computationally difficult problems, such as NP-complete decision problems and NP-hard optimization problems. In this paper we focus our attention on another computationally intractable problem: factorization. In particular, we first propose a simple method to encode binary numbers using multisets. Then, we describe three families of P systems: the first two allow to add and to multiply two binary encoded numbers, respectively, and the third solves the factorization problem.

  2. The Lasso Problem and Uniqueness

    CERN Document Server

    Tibshirani, Ryan J

    2012-01-01

    The lasso is a popular tool for sparse linear regression, especially for problems in which the number of variables p exceeds the number of observations n. But when p>n, the lasso criterion is not strictly convex, and hence it may not have a unique minimum. An important question is: when is the lasso solution well-defined (unique)? We review results from the literature, which show that if the predictor variables are drawn from a continuous probability distribution, then there is a unique lasso solution with probability one, regardless of the sizes of n and p. We also show that this result extends easily to $\\ell_1$ penalized minimization problems over a wide range of loss functions. A second important question is: how can we deal with the case of non-uniqueness in lasso solutions? In light of the aforementioned result, this case really only arises when some of the predictor variables are discrete, or when some post-processing has been performed on continuous predictor measurements. Though we certainly cannot c...

  3. Sexual Harassment: A problem unresolved!

    Directory of Open Access Journals (Sweden)

    N Vanishree

    2013-01-01

    Full Text Available Sexual harassment is a highly prevalent form of gender-based discrimination and sexual exploitation in the workplace and academic environment. In the dental field, there are a few studies regarding sexual harassment among the patients, professors and claims of their students. There is a silence of consent surrounding sexual harassment. It is clearly an issue about which the practicing dentists need to be informed in order to provide knowledgeable assessment and treatment for all patients. Dentists also have a role in advocacy, expert consultation or testimony, research and prevention through education and training. It is a fact that sexual harassment is very commonly encountered by almost everyone especially women. It is the most unresolved and under recognized problem of today especially when professionals are concerned. Preventing sexual harassment requires a considerable investment of time and personnel. This paper reviews the topic of sexual harassment as a problem from its legal aspects and recommendations for further steps to resolve this issue in dentistry.

  4. Causality problem in Economic Science

    Directory of Open Access Journals (Sweden)

    JOSÉ LUIS RETOLAZA

    2007-12-01

    Full Text Available The main point of the paper is the problem of the economy to be consider like a science in the most strict term of the concept. In the first step we are going to tackle a presentation about what we understand by science to subsequently present some of the fallacies which have bring certain scepticism about the scientific character of the investigation in economy, to know: 1 The differences between hard and weak sciences -physics and social; 2 The differences between paradigm, —positivist and phenomenological— 3 The differences between physic causalityand historic causality. In the second step we are going to talk about two fundamental problems which are questioned: 1 the confusion between ontology and gnoseology and, 2 the erroneous concept of causality that commonly is used. In the last step of the paper we are going over the recent models of «causal explanation» and we suggest the probabilistic casualty development next with a more elaborated models of causal explanation, like a way to conjugate the scientific severity with the possibility to tackle complex economic realities.

  5. The Query-commit Problem

    CERN Document Server

    Molinaro, Marco

    2011-01-01

    In the query-commit problem we are given a graph where edges have distinct probabilities of existing. It is possible to query the edges of the graph, and if the queried edge exists then its endpoints are irrevocably matched. The goal is to find a querying strategy which maximizes the expected size of the matching obtained. This stochastic matching setup is motivated by applications in kidney exchanges and online dating. In this paper we address the query-commit problem from both theoretical and experimental perspectives. First, we show that a simple class of edges can be queried without compromising the optimality of the strategy. This property is then used to obtain in polynomial time an optimal querying strategy when the input graph is sparse. Next we turn our attentions to the kidney exchange application, focusing on instances modeled over real data from existing exchange programs. We prove that, as the number of nodes grows, almost every instance admits a strategy which matches almost all nodes. This resu...

  6. SCHEDULING PROBLEMS-AN OVERVIEW

    Institute of Scientific and Technical Information of China (English)

    Asmuliardi MULUK; Hasan AKPOLAT; Jichao XU

    2003-01-01

    There seems to be a significant gap between the theoretical and the practical aspects of scheduling problems in the job shop environment. Theoretically, scheduling systems are designed on the basis of an optimum approach to the scheduling model. However in the practice, the optimum that is built into the scheduling applications seems to face some challenges when dealing with the dynamic character of a scheduling system, for instance machine breakdown or change of orders. Scheduling systems have become quite complex in the past few years. Competitive business environments and shorter product life cycles are the imminent challenges being faced by many companies these days.These challenges push companies to anticipate a demand driven supply chain in their business environment. A demand-driven supply chain incorporates the customer view into the supply chain processes. As a consequence of this, scheduling as a core process of the demand-driven supply chain must also reflect the customer view. In addition, other approaches to solving scheduling problems, for instance approaches based on human factors, prefer the scheduling system to be more flexible in both design and implementation. After discussion of these factors, the authors propose the integration of a different set of criteria for the development of scheduling systems which not only appears to have a better flexibility but also increased customer-focus.

  7. ESTUARINE AND COASTAL SEDIMENTATION PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Leo C.VAN RIJN

    2005-01-01

    This keynote lecture addresses engineering sedimentation problems in estuarine and coastal environments and practical solutions of these problems based on the results of field measurements,laboratory scale models and numerical models. The three most basic design rules are: (1) try to understand the physical system based on available field data; perform new field measurements if the existing field data set is not sufficient (do not reduce on the budget for field measurements); (2) try to estimate the morphological effects of engineering works based on simple methods (rules of thumb,simplified models,analogy models,i.e. comparison with similar cases elsewhere); and (3) use detailed models for fine-tuning and determination of uncertainties (sensitivity study trying to find the most influencial parameters). Engineering works should be designed in such a way that side effects (sand trapping,sand starvation,downdrift erosion) are minimum. Furthermore,engineering works should be designed and constructed or built in harmony rather than in conflict with nature. This 'building with nature' approach requires a profound understanding of the sediment transport processes in morphological systems.

  8. Solution to reverse refraction problem

    Science.gov (United States)

    Pavelyev, A. G.

    1985-04-01

    The reverse refraction problem (determination of radial profile of refractive index in planetary atmospheres, such as Earth, from radio probe measurements) is formulated as a bistatic radar problem for a spherically symmetric medium. The modified refractive index n(r)r (a-radius at which the refraction angle as function of relative distance is measured) is assumed to reach extreme values at the upper boundary r sub 1 or at observation level. Before the corresponding Fredholm equation of the first kind can be solved, it must be well-conditioned in the Tikhonov sense. This is done here by two quasi-optimum integral transformation variants with respect to the measurement function and subsequent simplified regularization. The first method is two successive Fourier cosine transformations followed by an Abel transformation, with the possibility of discrete Fourier transformations and numerical Abel transformation. The second method is twofold discrete Fourier transformation. Both yield solutions readily evaluated by simple algorithms. Regularization is effected by approximating functions satisfying the two fundamental conditions for convergence required of the measurement function.

  9. Is DDH still a problem?

    Directory of Open Access Journals (Sweden)

    Reinhard Graf

    2014-03-01

    Full Text Available Developmental dysplasia of the hip (DDH is the most frequent developmental disorder of the locomotor system. It is detected among 0.1–5.2% of newborns (1, 2. This might be the reason, that there is a high interest to detect DDH cases as early as possible. Undetected or late cases lead to catastrophes for the patient and family. Limping, leg length discrepancy, pain, frequent operations and sometimes femoral head necrosis, osteoarthritis, disability and finally total hip replacement even in young ages are results of a dysplastic hip that is not diagnosed on time or left untreated or treated improperly. Independent from individual patient problems the treatment costs for late or neglected cases are enormous. Costs of hospitalization, operations, rehabilitation, and indirect costs because of limited ability to work are incredible high. In countries with poor common health-system these patients have no chance for a normal life because of their disability.   How to solve or reduce the problem Clinical examination (Ortolani,Barlow etc. is used very often in different countries routinely, but not generally worldwide. The literature is quite clear; clinical examinations can reduce but not solve the problem. It need “well trained and experienced doctors”! But what is the definition of a “well trained and experienced doctor”? How it can happen, that in spite of clinical examination we see neglected cases? More than 5o% of DDH cases does not have any “typical” risk factor. The clinical examination is very often so subjective, that even fully dislocated joints cannot be detected and may be missed.   Critical questions 1- What is the Ortolani and the Barlow sign, the Glissement, the dry click sign, the phenomenon of the loose joint capsule and the “click” according to Tönnis D? 2- What sign in what age is normal? When does one of these signs change to the other one? 3- What is the pathology inside the joints, when you feel one of these

  10. Population problem in third world.

    Science.gov (United States)

    Joshi, N C

    1979-04-01

    Since numerous variables influence this growth rate, a holistic approach to the problem is mandatory. Fertility rates in developing countries remain high, not as a result of irrational behavior on the part of the people living in these countries, but as a result of their rational response to high infant mortality rates. Fertility rates will remain high unless the educational, health, and social environment in which these families live is improved. Economic development and population growth are intimately related. Development reduces the death rate resulting in increased population growth, which in turn reduces per capita income. In the developed nations, economic development occurred along with the development of new technologies and the reduction in mortality; therefore, population growth created an effective demand which further stimulated economic development. In developing countries the situation is different. Reduced mortality, the introduction of labor saving technology, and the high consumption aspirations derived from contact with capitalistic countries, have preceded economic development. Given the highly complex nature of the population problem, efforts must be made on many fronts including: 1) family planning promotion; 2) improvements in education, health, and social conditions for high fertility populations; 3) enhancement of worker skills; 4) rapid progress in technology; 5) greater capital accumulation and 5) economic reorganization.

  11. On Optimizing the Satisfiability (SAT) Problem

    Institute of Scientific and Technical Information of China (English)

    GU Jun; GU Qianping; DU Dingzhu

    1999-01-01

    The satisfiability(SAT) problem is abasic problem in computing theory. Presently, an active area of researchon SAT problem is to design efficient optimization algorithms forfinding a solution for a satisfiable CNF formula. A newformulation, the Universal SAT problem model, which transforms the SAT problem on Boolean space into an optimization problem on real spacehas been developed. Many optimization techniques,such as the steepest descent method, Newton's method, and thecoordinate descent method, can be used to solve the Universal SAT problem. In this paper, we prove that, when the initial solution issufficiently close to the optimal solution, the steepest descent methodhas a linear convergence ratio β<1, Newton's method has aconvergence ratio of order two, and the convergence ratio of thecoordinate descent method is approximately (1-β/m) for the Universal SAT problem with m variables. An algorithm based on the coordinate descent method for the Universal SAT problem is alsopresented in this paper.

  12. Four Tails Problems for Dynamical Collapse Theories

    CERN Document Server

    McQueen, Kelvin J

    2015-01-01

    The primary quantum mechanical equation of motion entails that measurements typically do not have determinate outcomes, but result in superpositions of all possible outcomes. Dynamical collapse theories (e.g. GRW) supplement this equation with a stochastic Gaussian collapse function, intended to collapse the superposition of outcomes into one outcome. But the Gaussian collapses are imperfect in a way that leaves the superpositions intact. This is the tails problem. There are several ways of making this problem more precise. But many authors dismiss the problem without considering the more severe formulations. Here I distinguish four distinct tails problems. The first (bare tails problem) and second (structured tails problem) exist in the literature. I argue that while the first is a pseudo-problem, the second has not been adequately addressed. The third (multiverse tails problem) reformulates the second to account for recently discovered dynamical consequences of collapse. Finally the fourth (tails problem di...

  13. Stabilisation problem in biaxial platform

    Science.gov (United States)

    Lindner, Tymoteusz; Rybarczyk, Dominik; Wyrwał, Daniel

    2016-12-01

    The article describes investigation of rolling ball stabilization problem on a biaxial platform. The aim of the control system proposed here is to stabilize ball moving on a plane in equilibrium point. The authors proposed a control algorithm based on cascade PID and they compared it with another control method. The article shows the results of the accuracy of ball stabilization and influence of applied filter on the signal waveform. The application used to detect the ball position measured by digital camera has been written using a cross platform .Net wrapper to the OpenCV image processing library - EmguCV. The authors used the bipolar stepper motor with dedicated electronic controller. The data between the computer and the designed controller are sent with use of the RS232 standard. The control stand is based on ATmega series microcontroller.

  14. COLLABORATIVE DESIGN OF MULTIPHYSICS PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    SONG Shaoyun; LI Shiqi

    2007-01-01

    Collaborative design is recommendedto solve multiphysics problems (MPPS). Firstly,mathematical model of MPPS is constructed and solved by a proposed partitioned method, analysis of which suggests that collaborative design be feasible to solve MPPS. As the key technology of collaborative design of MPPS, a task collaboration algorithm is then proposed. To develop the application framework of collaborative design, applied unified process(AUP) is proposed based on rational unified process(RUP). Then AUP is used to develop the collaborative design platform, whose function framework is constructed according to the process of project management. Finally three MPPS are solved on this platform and the results suggest that the proposed model, algorithm and framework be feasible.

  15. The Cosmological Lithium Problem Revisited

    CERN Document Server

    Bertulani, C A; Shubhchintak,

    2016-01-01

    After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.

  16. The cosmological lithium problem revisited

    Science.gov (United States)

    Bertulani, C. A.; Mukhamedzhanov, A. M.; Shubhchintak

    2016-07-01

    After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.

  17. European Archaeomagnetism: Progress and Problems

    Science.gov (United States)

    Evans, M. E.; Hoye, G.

    2009-05-01

    Much progress has been made since the seminal work of Giuseppe Folgheraiter (1856-1913) in the late 19th century. So much so that recent advances now make it possible to draw up complete isogonic and isoclinic maps for Europe and adjacent areas spanning the last three millennia (Pavon-Carrasco et al., 2009). Results based on multiple independent studies, with high precision and good age control are crucial and should be recognized as "anchor points" (e.g. Pompeii). On the other hand, the nagging problem of outliers persists. Among the possible causes are magnetic refraction, physical distortion, and inadequate chronological control. Some examples, drawn from our own investigations over the last 30 years, will be discussed in detail. These include previously unpublished data from a detailed study (more than 100 samples) of a kiln in southern Italy, and an apparently good (but aberrant) archaeodirection from a kiln in southern Spain.

  18. Ordering alternatives in MCDM problems

    Energy Technology Data Exchange (ETDEWEB)

    De Baets, B. [Ghent Univ. (Belgium). Dept. of Applied Mathematics and Computer Science

    1994-12-31

    A new approach to the study of a set of alternatives in a multi-criteria decision making problem is presented. Alternatives are described by means of fuzzy sets in the set of criteria, expressing the degrees to which they fulfill the different criteria. The concept of a fuzzy inclusion is introduced and is discussed from an axiomatic point of view. To each implication operator corresponds a fuzzy inclusion. The fuzzy inclusion corresponding to the Goedel operator is used to measure the degree to which the scores of one alternative are contained in the scores of another one. Repeating this for all couples of alternatives yields a fuzzy quasi-order relation in a set of alternatives. The cuts of this fuzzy relation are then classical quasi-order relations: they express orderings of the alternatives, allowing alternatives to be indifferent or incomparable, corresponding to different degrees of confidence.

  19. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  20. The Quantum Monty Hall Problem

    CERN Document Server

    D'Ariano, G M; Keyl, M; Kümmerer, B; Maassen, H; Werner, R F

    2002-01-01

    We consider a quantum version of a well-known statistical decision problem, whose solution is, at first sight, counter-intuitive to many. In the quantum version a continuum of possible choices (rather than a finite set) has to be considered. It can be phrased as a two person game between a player P and a quiz master Q. Then P always has a strategy at least as good as in the classical case, while Q's best strategy results in a game having the same value as the classical game. We investigate the consequences of Q storing his information in classical or quantum ways. It turns out that Q's optimal strategy is to use a completely entangled quantum notepad, on which to encode his prior information.

  1. Heat exchanger leakage problem location

    Science.gov (United States)

    Hejčík, Jiří; Jícha, Miroslav

    2012-04-01

    Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  2. Optimization in HIV screening problems

    Directory of Open Access Journals (Sweden)

    Lev Abolnikov

    2003-01-01

    Full Text Available In this article, the authors use both deterministic and stochastic approaches to the analysis of some optimization problems that arise in the group (“pool” HIV screening practice. Two kinds of testing policies are considered. For the first kind, group-individual testing, the optimal size of the group that should be selected for testing is found. For more general group-subgroup testing procedure the authors develop a numerical algorithm for finding the sequence of successively selected subgroups that minimizes the total cost of testing. Assuming that both arriving and testing processes have a random nature, the authors suggest a stochastic model in which the optimal size of the group in the group-individual testing procedure is found by using methods of queueing theory.

  3. Quantum Simulations of Physics Problems

    CERN Document Server

    Somma, R D; Knill, E; Gubernatis, J; Somma, Rolando; Ortiz, Gerardo; Knill, Emanuel; Gubernatis, James

    2003-01-01

    If a large Quantum Computer (QC) existed today, what type of physical problems could we efficiently simulate on it that we could not simulate on a classical Turing machine? In this paper we argue that a QC could solve some relevant physical "questions" more efficiently. The existence of one-to-one mappings between different algebras of observables or between different Hilbert spaces allow us to represent and imitate any physical system by any other one (e.g., a bosonic system by a spin-1/2 system). We explain how these mappings can be performed showing quantum networks useful for the efficient evaluation of some physical properties, such as correlation functions and energy spectra.

  4. Neurological problems of jazz legends.

    Science.gov (United States)

    Pearl, Phillip L

    2009-08-01

    A variety of neurological problems have affected the lives of giants in the jazz genre. Cole Porter courageously remained prolific after severe leg injuries secondary to an equestrian accident, until he succumbed to osteomyelitis, amputations, depression, and phantom limb pain. George Gershwin resisted explanations for uncinate seizures and personality change and herniated from a right temporal lobe brain tumor, which was a benign cystic glioma. Thelonious Monk had erratic moods, reflected in his pianism, and was ultimately mute and withdrawn, succumbing to cerebrovascular events. Charlie Parker dealt with mood lability and drug dependence, the latter emanating from analgesics following an accident, and ultimately lived as hard as he played his famous bebop saxophone lines and arpeggios. Charles Mingus hummed his last compositions into a tape recorder as he died with motor neuron disease. Bud Powell had severe posttraumatic headaches after being struck by a police stick defending Thelonious Monk during a Harlem club raid.

  5. Stabilisation problem in biaxial platform

    Directory of Open Access Journals (Sweden)

    Lindner Tymoteusz

    2016-12-01

    Full Text Available The article describes investigation of rolling ball stabilization problem on a biaxial platform. The aim of the control system proposed here is to stabilize ball moving on a plane in equilibrium point. The authors proposed a control algorithm based on cascade PID and they compared it with another control method. The article shows the results of the accuracy of ball stabilization and influence of applied filter on the signal waveform. The application used to detect the ball position measured by digital camera has been written using a cross platform .Net wrapper to the OpenCV image processing library - EmguCV. The authors used the bipolar stepper motor with dedicated electronic controller. The data between the computer and the designed controller are sent with use of the RS232 standard. The control stand is based on ATmega series microcontroller.

  6. The Greek public debt problem

    Directory of Open Access Journals (Sweden)

    Michalis Nikiforos

    2016-12-01

    Full Text Available The present paper examines the issue of the Greek public debt. After providing a historical discussion, we show that the austerity of the last six years has been unsuccessful in stabilizing the debt while, at the same time, it has taken a heavy toll on the economy and society. The recent experience shows that the public debt is unsustainable and therefore a restructuring is needed. An insistence on the current policies is not justifiable either on pragmatic or on moral or any other grounds. The experience of Germany in the early post-WWII period provides some useful hints for the way forward. A solution to the public debt problem is a necessary but not sufficient condition for the solution of the Greek and European crisis. A wider agenda that deals with the malaises of the Greek economy and the structural imbalances of the Eurozone is of vital importance.

  7. Outstanding problems in Mars aeronomy

    Science.gov (United States)

    Luhmann, J. G.

    1995-01-01

    Although the Phobos-2 spacecraft recently obtained important results relevant to some of the major remaining questions in Mars aeronomy, much remains to be done. In particular, not since the Viking Landers have we made in-situ measurements of aeronomical quantities such as atmospheric and ionospheric densities and temperatures below 400 km altitude. We have never made magnetic field measurements at these altitudes. Without such measurements we cannot unambiguously resolve arguments concerning issues such as the significance of the planetary magnetic field in the solar wind interaction, or understand the atmospheric cycle that leads to escape to space. With the trio of future orbiters including Mars Observer, Mars-94, and Planet-B we should see a veritable explosion of new knowledge, but some gaps in aeronomical science coverage will still remain. This paper briefly reviews some of the major unsolved problems in Mars aeronomy, and points out which are expected to remain outstanding after this flotilla of missions.

  8. COG validation: SINBAD Benchmark Problems

    Energy Technology Data Exchange (ETDEWEB)

    Lent, E M; Sale, K E; Buck, R M; Descalle, M

    2004-02-23

    We validated COG, a 3D Monte Carlo radiation transport code, against experimental data and MNCP4C simulations from the Shielding Integral Benchmark Archive Database (SINBAD) compiled by RSICC. We modeled three experiments: the Osaka Nickel and Aluminum sphere experiments conducted at the OKTAVIAN facility, and the liquid oxygen experiment conducted at the FNS facility. COG results are in good agreement with experimental data and generally within a few % of MCNP results. There are several possible sources of discrepancy between MCNP and COG results: (1) the cross-section database versions are different, MCNP uses ENDFB VI 1.1 while COG uses ENDFB VIR7, (2) the code implementations are different, and (3) the models may differ slightly. We also limited the use of variance reduction methods when running the COG version of the problems.

  9. A NONLINEAR FEASIBILITY PROBLEM HEURISTIC

    Directory of Open Access Journals (Sweden)

    Sergio Drumond Ventura

    2015-04-01

    Full Text Available In this work we consider a region S ⊂ given by a finite number of nonlinear smooth convex inequalities and having nonempty interior. We assume a point x 0 is given, which is close in certain norm to the analytic center of S, and that a new nonlinear smooth convex inequality is added to those defining S (perturbed region. It is constructively shown how to obtain a shift of the right-hand side of this inequality such that the point x 0 is still close (in the same norm to the analytic center of this shifted region. Starting from this point and using the theoretical results shown, we develop a heuristic that allows us to obtain the approximate analytic center of the perturbed region. Then, we present a procedure to solve the problem of nonlinear feasibility. The procedure was implemented and we performed some numerical tests for the quadratic (random case.

  10. Problem Prioritization in Usability Evaluation:

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2006-01-01

    Severity assessments enable prioritization of problems encountered during usability evaluations and thereby provide a device for guiding the utilization of design resources. However, designers' response to usability evaluations is also influenced by other factors, which may overshadow severity....... With the purpose of enhancing the impact of severity assessments, this study combines a field study of factors that influence the impact of evaluations with an experimental study of severity assessments made during usability inspections. The results show that even in a project receptive to input from evaluations...... their impact was highly dependent on conducting evaluations early. This accorded with an informal method that blended elements of usability evaluation and participatory design and could be extended with user-made severity assessments. The major cost associated with the evaluations was not finding but fixing...

  11. Solving computationally expensive engineering problems

    CERN Document Server

    Leifsson, Leifur; Yang, Xin-She

    2014-01-01

    Computational complexity is a serious bottleneck for the design process in virtually any engineering area. While migration from prototyping and experimental-based design validation to verification using computer simulation models is inevitable and has a number of advantages, high computational costs of accurate, high-fidelity simulations can be a major issue that slows down the development of computer-aided design methodologies, particularly those exploiting automated design improvement procedures, e.g., numerical optimization. The continuous increase of available computational resources does not always translate into shortening of the design cycle because of the growing demand for higher accuracy and necessity to simulate larger and more complex systems. Accurate simulation of a single design of a given system may be as long as several hours, days or even weeks, which often makes design automation using conventional methods impractical or even prohibitive. Additional problems include numerical noise often pr...

  12. Adaptive sampling for noisy problems

    Energy Technology Data Exchange (ETDEWEB)

    Cantu-Paz, E

    2004-03-26

    The usual approach to deal with noise present in many real-world optimization problems is to take an arbitrary number of samples of the objective function and use the sample average as an estimate of the true objective value. The number of samples is typically chosen arbitrarily and remains constant for the entire optimization process. This paper studies an adaptive sampling technique that varies the number of samples based on the uncertainty of deciding between two individuals. Experiments demonstrate the effect of adaptive sampling on the final solution quality reached by a genetic algorithm and the computational cost required to find the solution. The results suggest that the adaptive technique can effectively eliminate the need to set the sample size a priori, but in many cases it requires high computational costs.

  13. Isotropic bodies and Bourgain's problem

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    [1]Milman, V. D., Pajor, A., Isotropic position and inertia ellipsoid and zonoids of the unit ball of a normed ndimensional space, Geometric aspects of functional analysis (1987-1988), Lecture Notes in Math., 1989, 1376:64-104.[2]Blaschke, W., Uber affine Geometry ⅩⅣ: eine minimum Aufgabe fur Legendres tragheits Ellipsoid, Ber. verh.sachs. Akad. d. Wiss., 1918, 70: 72-75.[3]Blaschke, W., Uber affine Geometry Ⅺ: losing der "Vierpunkproblems" von Sylvester aus der Teorie der geometrischen Wahrsdeinlichkeiten, Leipziger Berichte, 1917, 69: 436-453.[4]John, F., Polar correspondence with respect to convex regions, Duke Math. J., 1937, 3(2): 355-369.[5]Lutwak, E., Yang, D., Zhang, G., A new ellipsoid associated with convex bodes, Duke. Math. J., 2000, 104:375-390.[6]Bourgain, J., On the distribution of polynomails on high dimensional convex sets, Geometric aspects of functional analysis (1989-1990), Lecture Notes in Math., 1991, 1469: 127-137.[7]Dar, S., Remarks on Bourgain's problem on slicing of convex bodies, Geomitric aspects of functional analysis,in Oper. Theory Adv. Appl., Vol, 77, Basel: Birkhauser, 1995, 61-66.[8]Ball, K., Normed spaces with a weak-Gordon-Lewis property, in: Proc. of Funct. Anal., University of Texas and Austin (1987-1989), Lecture Notes in Math., 1991, 1470: 36-47.[9]Schneider, R., Weil, W., Zonoids and related topics, in Convexity and Its Applications (eds. Gruber, P. M., Wills,J. M.), Basel: Birkhauser, 1983, 296-317.[10]Bourgain, J., Klartag, B., Milman, V., A reduction of the slicing problem to finite volume ratio bodies, Geometry/Functional Analysis, C. R. Acad. Sci. Paris, Ser. I, 2003, 336: 331-334.[11]Ren, D. L., An Introduction to Integral Geometry (in Chinese), Shanghai: Science and Technology Press, 1988.[12]Gardner, R. J., Geometric Tomography, Cambridge: Cambridge University Press, 1995.[13]Leichtweiβ, K., Affine Geometry of Convex Bodies, Heidelberg: J. A. Barth, 1998.[14]Schneider, R., Convex Bodies: The Brunn

  14. Security Problems in Cloud Computing

    Directory of Open Access Journals (Sweden)

    Rola Motawie

    2016-12-01

    Full Text Available Cloud is a pool of computing resources which are distributed among cloud users. Cloud computing has many benefits like scalability, flexibility, cost savings, reliability, maintenance and mobile accessibility. Since cloud-computing technology is growing day by day, it comes with many security problems. Securing the data in the cloud environment is most critical challenges which act as a barrier when implementing the cloud. There are many new concepts that cloud introduces, such as resource sharing, multi-tenancy, and outsourcing, create new challenges for the security community. In this work, we provide a comparable study of cloud computing privacy and security concerns. We identify and classify known security threats, cloud vulnerabilities, and attacks.

  15. Some boys' problems in education

    DEFF Research Database (Denmark)

    Jørgensen, Christian Helms

    2015-01-01

    to general education, but social and institutional processes of differentiation in the vocational schools place a significant group of students in a position where they have little chance of completing the programme. In the conclusion, some reflections are made on the effect of a recent reform of VET......The last two decades have seen an increasing political concern in the high dropout rates and low performance in education of boys compared to girls – at times in the form of a ‘moral panic’. This has also been the case in Denmark where ‘the boy problem’ in education now is placed high on the agenda...... of education policy. The purpose of this article is to examine this ‘boy problem’ in relation to the dual system of vocational education and training (VET) in Denmark. By considering the gender divisions and the value of the VET programmes on the labour market, it explores what kind of problems boys have...

  16. Problems with German Science Education

    Science.gov (United States)

    Riess, Falk

    The main problems of science (especially physics) teaching in Germany are students'' lack of interest and motivation in the subject, their poor understanding of scientific concepts, ideas, methods,and results, and their lack of comprehension of the social, political, and epistemological role of science. These circumstances result in a growing `scientific illiteracy'' of the population and adecline in democratic quality concerning decision making processes about scientific and technological projects. One means of improving this situation lies in the use of history and philosophy of science in science teaching. School science curricula and textbooks neglect almost completely the importance of history and philosophy of science. In this paper, the main empirical results concerning motivation and knowledge are given. Some examples from science curricula and textbooks are presented, and some of the few reform projects in Germany are listed. As a consequence a compensatory program is proposed in order to create the prerequisites for raising science education in Germany to an international standard.

  17. Problems with drugs in Croatia.

    Science.gov (United States)

    Vrhovac, B

    1997-01-01

    Croatia has 4.8 million inhabitants, 11,800 physicians, 2000 pharmacists, two now shareholding, pharmaceutical companies (about 6500 employees, total sales of about 350 million US dollars). There are a number of problems due to the war (GNP fell from 3800 to about 1500 US dollars), occupation of 25% of its territory, 0.5 million refugees and lack of resources (139 US dollars/capita for health, about 40 US dollars i.e. 30%!! for drugs)--about three times less than before the aggression. The drug situation is controlled with the help of: (1) donations (approximate value of 600 million US dollars since 1991 from Europe and US), (2) (essential) drug formularies--250 for outpatients, and 580 generic names for various levels of hospital use, (3) special efforts to purchase drugs of good quality at a reasonable price (a kind of tender), (4) control of prescribing (prescriptions, specialists referral) especially by GPs. A new Medicines Act is in preparation and about 1000 generic names are on the market. DRUG EDUCATION: Pharmaca: the Croatian journal of pharmacotherapy has been published since 1962, there are several Drug bulletins (one published since 1975); special chapters on clinical pharmacology in textbooks, translation of three editions of Laurence's textbook with special commentary and adaptation to local needs; ADR spontaneous and intensive monitoring (WHO programme) with a personal feedback to the reporters and regular articles on drug use in a number of periodicals. Data on drug consumption indicates that there is room for improvement of prescribing. There is an enthusiasm for 'vasoactive drugs'--after dipirydamole came oxpentifylline and antimicrobials are always overprescribed. All these problems will hopefully decrease when the war finally stops and when industry (especially tourism) starts being fruitful again. In any case the importance of teaching of pharmacotherapy at the under- and postgraduate level should be recognized.

  18. Inconsistent Investment and Consumption Problems

    Energy Technology Data Exchange (ETDEWEB)

    Kronborg, Morten Tolver, E-mail: mtk@atp.dk [ATP (Danish Labour Market Supplementary Pension Scheme) (Denmark); Steffensen, Mogens, E-mail: mogens@math.ku.dk [University of Copenhagen, Department of Mathematical Sciences (Denmark)

    2015-06-15

    In a traditional Black–Scholes market we develop a verification theorem for a general class of investment and consumption problems where the standard dynamic programming principle does not hold. The theorem is an extension of the standard Hamilton–Jacobi–Bellman equation in the form of a system of non-linear differential equations. We derive the optimal investment and consumption strategy for a mean-variance investor without pre-commitment endowed with labor income. In the case of constant risk aversion it turns out that the optimal amount of money to invest in stocks is independent of wealth. The optimal consumption strategy is given as a deterministic bang-bang strategy. In order to have a more realistic model we allow the risk aversion to be time and state dependent. Of special interest is the case were the risk aversion is inversely proportional to present wealth plus the financial value of future labor income net of consumption. Using the verification theorem we give a detailed analysis of this problem. It turns out that the optimal amount of money to invest in stocks is given by a linear function of wealth plus the financial value of future labor income net of consumption. The optimal consumption strategy is again given as a deterministic bang-bang strategy. We also calculate, for a general time and state dependent risk aversion function, the optimal investment and consumption strategy for a mean-standard deviation investor without pre-commitment. In that case, it turns out that it is optimal to take no risk at all.

  19. Inverse Eigenvalue Problem in Structural Dynamics Design

    Institute of Scientific and Technical Information of China (English)

    Huiqing Xie; Hua Dai

    2006-01-01

    A kind of inverse eigenvalue problem in structural dynamics design is considered. The problem is formulated as an optimization problem. The properties of this problem are analyzed, and the existence of the optimum solution is proved. The directional derivative of the objective function is obtained and a necessary condition for a point to be a local minimum point is given. Then a numerical algorithm for solving the problem is presented and a plane-truss problem is discussed to show the applications of the theories and the algorithm.

  20. Highly indefinite multigrid for eigenvalue problems

    Energy Technology Data Exchange (ETDEWEB)

    Borges, L.; Oliveira, S.

    1996-12-31

    Eigenvalue problems are extremely important in understanding dynamic processes such as vibrations and control systems. Large scale eigenvalue problems can be very difficult to solve, especially if a large number of eigenvalues and the corresponding eigenvectors need to be computed. For solving this problem a multigrid preconditioned algorithm is presented in {open_quotes}The Davidson Algorithm, preconditioning and misconvergence{close_quotes}. Another approach for solving eigenvalue problems is by developing efficient solutions for highly indefinite problems. In this paper we concentrate on the use of new highly indefinite multigrid algorithms for the eigenvalue problem.