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Sample records for techniques solve metalworking

  1. 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,…

  2. An evaluation of analytical methods, air sampling techniques, and airborne occupational exposure of metalworking fluids.

    Science.gov (United States)

    Verma, Dave K; Shaw, Don S; Shaw, M Lorraine; Julian, Jim A; McCollin, Shari-Ann; des Tombe, Karen

    2006-02-01

    This article summarizes an assessment of air sampling and analytical methods for both oil and water-based metalworking fluids (MWFs). Three hundred and seventy-four long-term area and personal airborne samples were collected at four plants using total (closed-face) aerosol samplers and thoracic samplers. A direct-reading device (DustTrak) was also used. The processes sampled include steel tube making, automotive component manufacturing, and small part manufacturing in a machine shop. The American Society for Testing and Materials (ASTM) Method PS42-97 of analysis was evaluated in the laboratory. This evaluation included sample recovery, determination of detection limits, and stability of samples during storage. Results of the laboratory validation showed (a) the sample recovery to be about 87%, (b) the detection limit to be 35 microg, and (c) sample stability during storage at room temperature to decline rapidly within a few days. To minimize sample loss, the samples should be stored in a freezer and analyzed within a week. The ASTM method should be the preferred method for assessing metalworking fluids (MWFs). The ratio of thoracic aerosol to total aerosol ranged from 0.6 to 0.7. A similar relationship was found between the thoracic extractable aerosol and total extractable aerosol. The DustTrak, with 10-microm sampling head, was useful in pinpointing the areas of potential exposure. MWF exposure at the four plants ranged from 0.04 to 3.84 mg/m3 with the geometric mean ranging between 0.22 to 0.59 mg/m3. Based on this data and the assumption of log normality, MWF exposures are expected to exceed the National Institute for Occupational Safety and Health recommended exposure limit of 0.5 mg/m3 as total mass and 0.4 mg/m3 as thoracic mass about 38% of the time. In addition to controlling airborne MWF exposure, full protection of workers would require the institution of programs for fluid management and dermal exposure prevention.

  3. Techniques for Solving Sudoku Puzzles

    CERN Document Server

    Chi, Eric C

    2012-01-01

    Solving Sudoku puzzles is one of the most popular pastimes in the world. Puzzles range in difficulty from easy to very challenging; the hardest puzzles tend to have the most empty cells. The current paper compares the performance of three computer algorithms in solving puzzles. Backtracking, simulated annealing, and alternating projections are generic methods for attacking combinatorial optimization problems. Our results favor backtracking. It infallibly solves Sudoku puzzles or deduces that a unique solution does not exist. However, backtracking does not scale well in high-dimensional combinatorial optimization. Hence, it is useful to expose statistics students to the other two solution techniques in a concrete setting. Simulated annealing shares a common structure with MCMC (Markov chain Monte Carlo) and enjoys wide applicability. The method of alternating projections solves the feasibility problem in convex programming. Converting a discrete optimization problem into a continuous optimization problem opens...

  4. Crime Solving Techniques: Training Bulletin.

    Science.gov (United States)

    Sands, Jack M.

    The document is a training bulletin for criminal investigators, explaining the use of probability, logic, lateral thinking, group problem solving, and psychological profiles as methods of solving crimes. One chpater of several pages is devoted to each of the five methods. The use of each method is explained; problems are presented for the user to…

  5. Applying Cooperative Techniques in Teaching Problem Solving

    Directory of Open Access Journals (Sweden)

    Krisztina Barczi

    2013-12-01

    Full Text Available Teaching how to solve problems – from solving simple equations to solving difficult competition tasks – has been one of the greatest challenges for mathematics education for many years. Trying to find an effective method is an important educational task. Among others, the question arises as to whether a method in which students help each other might be useful. The present article describes part of an experiment that was designed to determine the effects of cooperative teaching techniques on the development of problem-solving skills.

  6. [Metalworking industry management evolution].

    Science.gov (United States)

    Mattucci, Massimo

    2011-01-01

    Analysis of the evolution drivers of the management systems in the metalworking industry, mainly characterized as "automotive", starting with the "mass production" model, followed for the development of Italian industry in the '50. Through the socio-economic changes of the '90/10, the metalworking plants were deeply restructured with the introduction of computers in the production systems, and then with the first global benchmarks such as the "lean production", towards the needed operational flexibility to respond to the market dynamics. Plants change radically, company networks become real, ICT services are fundamental elements for the integration. These trends help visualizing a new "Factory of the Future" for the years 2020/30, where the competition will be based on the socio-economical, technological and environmental factors included in the "Competitive Sustainable Manufacturing" paradigm.

  7. Metalworking and machining fluids

    Science.gov (United States)

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  8. Problem-Solving Techniques in the Management of Conflicts among ...

    African Journals Online (AJOL)

    Problem-Solving Techniques in the Management of Conflicts among Rural Dwellers in ... skills acquired in problem-solving techniques and conflict management ... Besides, conflict management should involve intensive negotiation, the use of ...

  9. Applying Cooperative Techniques in Teaching Problem Solving

    Science.gov (United States)

    Barczi, Krisztina

    2013-01-01

    Teaching how to solve problems--from solving simple equations to solving difficult competition tasks--has been one of the greatest challenges for mathematics education for many years. Trying to find an effective method is an important educational task. Among others, the question arises as to whether a method in which students help each other might…

  10. Hybrid computer techniques for solving partial differential equations

    Science.gov (United States)

    Hammond, J. L., Jr.; Odowd, W. M.

    1971-01-01

    Techniques overcome equipment limitations that restrict other computer techniques in solving trivial cases. The use of curve fitting by quadratic interpolation greatly reduces required digital storage space.

  11. Solving fault diagnosis problems linear synthesis techniques

    CERN Document Server

    Varga, Andreas

    2017-01-01

    This book addresses fault detection and isolation topics from a computational perspective. Unlike most existing literature, it bridges the gap between the existing well-developed theoretical results and the realm of reliable computational synthesis procedures. The model-based approach to fault detection and diagnosis has been the subject of ongoing research for the past few decades. While the theoretical aspects of fault diagnosis on the basis of linear models are well understood, most of the computational methods proposed for the synthesis of fault detection and isolation filters are not satisfactory from a numerical standpoint. Several features make this book unique in the fault detection literature: Solution of standard synthesis problems in the most general setting, for both continuous- and discrete-time systems, regardless of whether they are proper or not; consequently, the proposed synthesis procedures can solve a specific problem whenever a solution exists Emphasis on the best numerical algorithms to ...

  12. 7 CFR 2902.41 - Metalworking fluids.

    Science.gov (United States)

    2010-01-01

    ... operations such as cutting, drilling, grinding, machining, and tapping. (2) Metalworking fluids for which... when applied to metal feedstock during normal grinding and machining operations. (iii) High performance... during grinding and machining operations involving unusually high temperatures or corrosion potential....

  13. CHEBYSHEV ACCELERATION TECHNIQUE FOR SOLVING FUZZY LINEAR SYSTEM

    Directory of Open Access Journals (Sweden)

    S.H. Nasseri

    2009-10-01

    Full Text Available In this paper, Chebyshev acceleration technique is used to solve the fuzzy linear system (FLS. This method is discussed in details and followed by summary of some other acceleration techniques. Moreover, we show that in some situations that the methods such as Jacobi, Gauss-Sidel, SOR and conjugate gradient is divergent, our proposed method is applicable and the acquired results are illustrated by some numerical examples.

  14. Solving Systems of Equations with Techniques from Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Irina Maria Terfaloaga

    2015-07-01

    Full Text Available A frequent problem in numerical analysis is solving the systems of equations. That problem has generated in time a great interest among mathematicians and computer scientists, as evidenced by the large number of numerical methods developed. Besides the classical numerical methods, in the last years were proposed methods inspired by techniques from artificial intelligence. Hybrid methods have been also proposed along the time [15, 19]. The goal of this study is to make a survey of methods inspired from artificial intelligence for solving systems of equations

  15. Integration of Problem-Solving Techniques in Agriculture

    OpenAIRE

    1989-01-01

    Problem-solving techniques such as modeling, simulation, optimization, and network analysis have been used extensively to help agricultural scientists and practitioners understand and control biological systems. By their nature, most of these systems are difficult to quantitatively define. Many of the models and simulations that have been developed lack a user interface which enables people other than the developer to use them. As a result, several scientists are integrating knowledge-based- ...

  16. APPLICATION OF EXPLOSIVE ENERGY IN METALWORKING

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    Vječislav Bohanek

    2013-07-01

    Full Text Available When an explosive charge is detonate, considerable amount of energy in a very short period of time is released. Energy, released in this way, is used for performing various kinds of useful work. Most explosives are consumed to obtain mineral raw materials in the mining industry and for various excavations in the construction industry. One of the specific areas of application explosive energy is an area of explosive metalworking. Using energy of explosive metal is welded, formed, cuts, harden etc. This paper presents an overview of the existing explosive metalworking methods. Methods are explained and comparative advantages in comparison to conventional metalworking methods are given (the paper is published in Croatian.

  17. The Effects of Pair Problem Solving Technique Incorporating Polya's Problem Solving Strategy on Undergraduate Students' Performance in Chemistry

    Science.gov (United States)

    Bilgin, Ibrahim

    2006-01-01

    The purpose of this study was to investigate the effects of pair problem solving technique incorporating Polya's problem solving strategy on undergraduate students' performance in conceptual and algorithmic questions in chemistry. The subjects of this study were 89 students enrolled from two first year chemistry classes. The experimental group was…

  18. Metalworking Techniques Unlock a Unique Alloy

    Science.gov (United States)

    2015-01-01

    Approached by West Hartford, Connecticut-based Abbot Ball Company, Glenn Research Center agreed to test an intriguing alloy called Nitinol 60 that had been largely unused for a half century. Using powdered metallurgy, the partners developed a method for manufacturing and working with the material, which Abbott Ball has now commercialized. Nitinol 60 provides a unique combination of qualities that make it an excellent material for ball bearings, among other applications.

  19. Mamluk metalwork fittings in their artistic and architectural context

    NARCIS (Netherlands)

    Mols, Luitgard Eva Maria

    2006-01-01

    This study of Mamluk metalwork fittings presents a hitherto largely ignored body of Mamluk metalwork objects, i.e. metal-faced doors, doorknockers, window grilles, and window shutters, and aims to trace their stylistic and technical development throughout the Mamluk period. In order to establish the

  20. Applying recursive numerical integration techniques for solving high dimensional integrals

    Energy Technology Data Exchange (ETDEWEB)

    Ammon, Andreas [IVU Traffic Technologies AG, Berlin (Germany); Genz, Alan [Washington State Univ., Pullman, WA (United States). Dept. of Mathematics; Hartung, Tobias [King' s College, London (United Kingdom). Dept. of Mathematics; Jansen, Karl; Volmer, Julia [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Leoevey, Hernan [Humboldt Univ. Berlin (Germany). Inst. fuer Mathematik

    2016-11-15

    The error scaling for Markov-Chain Monte Carlo techniques (MCMC) with N samples behaves like 1/√(N). This scaling makes it often very time intensive to reduce the error of computed observables, in particular for applications in lattice QCD. It is therefore highly desirable to have alternative methods at hand which show an improved error scaling. One candidate for such an alternative integration technique is the method of recursive numerical integration (RNI). The basic idea of this method is to use an efficient low-dimensional quadrature rule (usually of Gaussian type) and apply it iteratively to integrate over high-dimensional observables and Boltzmann weights. We present the application of such an algorithm to the topological rotor and the anharmonic oscillator and compare the error scaling to MCMC results. In particular, we demonstrate that the RNI technique shows an error scaling in the number of integration points m that is at least exponential.

  1. Applying recursive numerical integration techniques for solving high dimensional integrals

    CERN Document Server

    Ammon, Andreas; Hartung, Tobias; Jansen, Karl; Leövey, Hernan; Volmer, Julia

    2016-01-01

    The error scaling for Markov-Chain Monte Carlo techniques (MCMC) with $N$ samples behaves like $1/\\sqrt{N}$. This scaling makes it often very time intensive to reduce the error of computed observables, in particular for applications in lattice QCD. It is therefore highly desirable to have alternative methods at hand which show an improved error scaling. One candidate for such an alternative integration technique is the method of recursive numerical integration (RNI). The basic idea of this method is to use an efficient low-dimensional quadrature rule (usually of Gaussian type) and apply it iteratively to integrate over high-dimensional observables and Boltzmann weights. We present the application of such an algorithm to the topological rotor and the anharmonic oscillator and compare the error scaling to MCMC results. In particular, we demonstrate that the RNI technique shows an error scaling in the number of integration points $m$ that is at least exponential.

  2. Numerical techniques for solving nonlinear instability problems in smokeless tactical solid rocket motors. [finite difference technique

    Science.gov (United States)

    Baum, J. D.; Levine, J. N.

    1980-01-01

    The selection of a satisfactory numerical method for calculating the propagation of steep fronted shock life waveforms in a solid rocket motor combustion chamber is discussed. A number of different numerical schemes were evaluated by comparing the results obtained for three problems: the shock tube problems; the linear wave equation, and nonlinear wave propagation in a closed tube. The most promising method--a combination of the Lax-Wendroff, Hybrid and Artificial Compression techniques, was incorporated into an existing nonlinear instability program. The capability of the modified program to treat steep fronted wave instabilities in low smoke tactical motors was verified by solving a number of motor test cases with disturbance amplitudes as high as 80% of the mean pressure.

  3. Vaporization and Conversion of Ethanolamines used in Metalworking Operations

    Directory of Open Access Journals (Sweden)

    Shin-bum Kim

    2010-12-01

    Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

  4. Solving conformal contacts using multi-Hertzian techniques

    Science.gov (United States)

    Pascal, Jean-Pierre; Soua, Brahim

    2016-06-01

    Recently, publications aiming at wheel-rail contact surveys let readers think that multi-Hertzian methods present severe drawbacks with respect to 'virtual penetration' methods. These surveys criticise multi-Hertzian solutions mainly because presenting 'larger contacts overlaps' and 'frequent secondary contacts near the border of the first contact', both obvious geometric possibilities of which the practical occurrence and eventual inconvenience would remain purely theoretical unless established over definite methods demonstrating poor practical results. Recent surveys all quote Piotrowski-Chollet 2005 survey of wheel-rail contact models that attempted to illustrate defective multi-Hertzian techniques by concentrating on the method initiated by Sauvage in the 1990s and further developed by Pascal. The 2005 paper not only gives no evidence of practical inconveniences of Sauvage's method but also confuses static geometric contact overlaps with the dynamical overlapping of forces. In reality it mixes Sauvage method up with a quite different technique. Thus a clarification is now necessary by reminding what the proper Sauvage technique really is and by showing some of its practical successful applications. The present paper, focusing on determination of normal contact forces in conformal situations, intends to explain clearly the advantages of the unequivocal localisation of secondary ellipses in that multi-Hertzian method which has been developed in INRETS VOCO codes in the 1990s and successfully used by SNCF and ALSTOM in the INRETS-SNCF code, VOCODYM, and later in Pascal's online calculation of railway elastic contacts code. It proved its effectiveness for studying freight wagons derailments as well as rail wear and head-check, unrounded wheels wear, high-speed lines' deformations or TGV comfort. While simulating American ACELA trainsets' behaviour on the US North-East Corridor tracks, prior to actual tests, as part of the commercial contract. It has been also a

  5. The Shifting Technique for Solving a Nonsymmetric Algebraic Riccati Equation

    CERN Document Server

    Chiang, Chun-Yueh

    2011-01-01

    This paper analyzes a special instance of nonsymmetric algebraic matrix Riccati equations arising from transport theory. Traditional approaches for finding the minimal nonnegative solution of the matrix Riccati equations are based on the fixed point iteration and the speed of the convergence is linear. Relying on simultaneously matrix computation, a structure-preserving doubling algorithm (SDA) with quadratic convergence is designed for improving the speed of convergence. The difficulty is that the double algorithm with quadratic convergence cannot guarantee to work all the time. Our main trust in this work is to show that applied with a suitable shifted technique, the SDA is guaranteed to converge quadratically with no breakdown. Also, we modify the conventional simple iteration algorithm in the critical case to dramatically improve the speed of convergence. Numerical experiments strongly suggest that the total number of computational steps can be significantly reduced via the shifting procedure.

  6. Bound state techniques to solve the multiparticle scattering problem

    CERN Document Server

    Carbonell, J; Fonseca, A C; Lazauskas, R

    2013-01-01

    Solution of the scattering problem turns to be very difficult task both from the formal as well as from the computational point of view. If the last two decades have witnessed decisive progress in ab initio bound state calculations, rigorous solution of the scattering problem remains limited to A$\\leq$4 case. Therefore there is a rising interest to apply bound-state-like methods to handle non-relativistic scattering problems. In this article the latest theoretical developments in this field are reviewed. Five fully rigorous methods will be discussed, which address the problem of nuclear collisions in full extent (including the break-up problem) at the same time avoiding treatment of the complicate boundary conditions or integral kernel singularities. These new developments allows to use modern bound-state techniques to advance significantly rigorous solution of the scattering problem.

  7. A new iterative heuristic to solve the joint replenishment problem using a spreadsheet technique

    NARCIS (Netherlands)

    Nilsson, A.; Segerstedt, A.; van der Sluis, E.

    2007-01-01

    In this paper, a heuristic method is presented which gives a novel approach to solve joint replenishment problems (JRP) with strict cycle policies. The heuristic solves the JRP in an iterative procedure and is based on a spreadsheet technique. The principle of the recursion procedure is to find a ba

  8. Triple-plane technique for breast augmentation: solving animation deformities.

    Science.gov (United States)

    Bracaglia, Roberto; Tambasco, Damiano; Gentileschi, Stefano; D'Ettorre, Marco

    2013-08-01

    An unpleasant consequence of subpectoral implant placement is the occurrence of animation deformities during pectoralis muscle contraction. This study aimed to review the results achieved for 524 patients undergoing the triple-plane technique with respect to loss of animation deformities. The evaluation was performed by a group of three plastic surgeons according to the Spear grading system for breast distortion using a 4-point scale. Of the 524 patients evaluated, 351 (67 %) were rated as grade 1 (no distortion), 156 (29.77 %) as grade 2 (mild distortion), 17 (3 %) as grade 3 (moderate distortion), and 0 (0 %) as 4 (severe distortion).The excellent results achieved can be explained by the horizontal sectioning of the major pectoralis muscle at the areola level to the sternal margin. In fact, it determines that superior to sectioning of the muscle, its activity remains normal, with a low degree of dynamic deformities. On the contrary, inferiorly, at the muscular-aponeurotic plane level, no activity is detected, with no resultant animation deformities. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  9. A comparison of several computational techniques for solving some common aeronomic problems

    Science.gov (United States)

    Turco, R. P.; Whitten, R. C.

    1974-01-01

    Several numerical integration techniques for solving common aeronomic problems involving species rate equations are compared for speed and accuracy. A newer technique that defines families of species that are nearly conserved is found to be superior to an iterative technique when both methods are applied to simple test problems. The 'conservation' technique is also found to be more economical than the more complex Gear (1969) integration scheme for comparable accuracy.

  10. Microorganisms in metalworking fluids: Current issues in research and management

    Directory of Open Access Journals (Sweden)

    Elżbieta A. Trafny

    2013-02-01

    Full Text Available The microbial contamination of water miscible metalworking fl uids (MWFs is a serious problem in metal industry. A good maintenance of MWF re-circulation systems can extend the lifetime of coolants and ensure the quality of the tools produced. In MWFs, as in the other water-based environments, microorganisms usually live in the form of biofi lms, the communities of bacteria and fungi attached to the surface of sumps, metal parts and also to each other. Biofi lms exhibit very high resistance to biocides. The effect of biocides that are used as additives to MWFs to control the growth of the bacterial and fungal microbiomes (microorganisms characteristic to the individual coolant system have become the subject of research only in recent years. There are also only sparse reports on the impact of biocides on microorganisms growing in biofi lms in MWF installations. Fast growing mycobacteria are important members of these biofi lm communities. Their presence has recently been linked with the occurrence of cases of hypersensitivity pneumonitis, a serious respiratory disorder in the metal industry employees. The new, relatively fast and inexpensive techniques to assess the species diversity within MWF microbiomes and their population size should be developed in order to control the microorganisms’ proliferation in MWFs and to diminish the occupational exposure to harmful bioaerosols in metal industry.

  11. A technique for solving constraint satisfaction problems using Prolog's definite clause grammars

    Science.gov (United States)

    Nachtsheim, Philip R.

    1988-01-01

    A new technique for solving constraint satisfaction problems using Prolog's definite clause grammars is presented. It exploits the fact that the grammar rule notation can be viewed as a state exchange notation. The novel feature of the technique is that it can perform informed as well as blind search. It provides the Prolog programmer with a new technique for application to a wide range of design, scheduling, and planning problems.

  12. Analysis of allergens in metalworking fluids.

    Science.gov (United States)

    Henriks-Eckerman, Maj-Len; Suuronen, Katri; Jolanki, Riitta

    2008-11-01

    Metalworking fluids (MWFs) are well-known causes of occupational contact dermatitis in machinists. To gain information about skin sensitizers in MWFs and to compare it with the information in safety data sheets (SDSs). A total of 17 samples of MWF concentrates were analysed for skin sensitizers known or suspected to be used in MWF. Alkanolamines, formaldehyde, isothiazolinones, methyldibromo glutaronitrile (MDBGN), and iodopropynyl butylcarbamate (IPBC) were separated by liquid chromatography. Resin acids of colophonium (colophony) were separated by gas chromatography. The substances were identified with mass spectrometric detection and ultraviolet detection. Of the MWFs, 15 contained 6-39% of alkanolamines, mostly monoethanolamine and triethanolamine. Formaldehyde was detected in all MWFs: the concentrations of total formaldehyde ranged between 0.002% and 1.3%. Benzisothiazolinone and octylisothiazolinone were detected in one fluid each. IPBC was detected in nine MWFs, and the highest concentration was 0.09%. Methylisothiazolinone and MDBGN were not detected in any of the fluids. Resin acids of colophonium were detected in seven MWFs in concentrations ranging from 0.41% to 3.8%. On the whole, the allergens analysed were poorly declared in the SDSs. The content of total formaldehyde was not declared in any SDS. IPBC, a relatively new allergen, seems to be common in MWFs. Isothiazolinones may be relevant allergens of machinists, and they should be analysed in MWFs in case other sources are not identified. The occupational relevance of positive patch test results to MWF ingredients in machinists is difficult to determine if information in the SDSs is relied upon.

  13. Chemometric classification techniques as a tool for solving problems in analytical chemistry.

    Science.gov (United States)

    Bevilacqua, Marta; Nescatelli, Riccardo; Bucci, Remo; Magrì, Andrea D; Magrì, Antonio L; Marini, Federico

    2014-01-01

    Supervised pattern recognition (classification) techniques, i.e., the family of chemometric methods whose aim is the prediction of a qualitative response on a set of samples, represent a very important assortment of tools for solving problems in several areas of applied analytical chemistry. This paper describes the theory behind the chemometric classification techniques most frequently used in analytical chemistry together with some examples of their application to real-world problems.

  14. Solving Inverse Kinematics – A New Approach to the Extended Jacobian Technique

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    M. Šoch

    2005-01-01

    Full Text Available This paper presents a brief summary of current numerical algorithms for solving the Inverse Kinematics problem. Then a new approach based on the Extended Jacobian technique is compared with the current Jacobian Inversion method. The presented method is intended for use in the field of computer graphics for animation of articulated structures. 

  15. System of performance indicators for SMEs, metalworking sector

    Directory of Open Access Journals (Sweden)

    Cristina Viteri Sánchez

    2014-03-01

    Full Text Available (Received: 2013/03/05 - Accepted: 2013/03/25This paper focused on the design and proposal of management indicators for small and medium metalworking enterprises (SMEs in Quito. Metalworking number was established for the study. It was met and determined which areas deserve to be constantly monitored, by analyzing the performance of the companies, for this purpose, it was used a SWOT analysis, interviews and meetings with company managers , the results demanded the approach of a generic strategy, which included the formulation of the mission , vision and corporate values. Objectives and goals were established, they were classified according to the four perspectives of the Balanced Scorecard. Then it was possible to identify indicators to measure the proper functioning of the strategy proposed. 10 indicators of management were developed, according to the analysis of the reality of metalworking enterprises. So it was determined 3 financial indicators, 2 indicators focused on customers, 3 indicators for monitor internal business processes and 2 addressed the prospect of learning and growth. The use of these indicators is the key of performance and process control in each metalworking company.

  16. Transportation Problem with Pentagonal Intuitionistic Fuzzy Numbers Solved Using Ranking Technique and Russell’s Method

    Directory of Open Access Journals (Sweden)

    Dr.M.S.Annie Christi,

    2016-02-01

    Full Text Available This paper presents a solution methodology for transportation problem in an intuitionistic fuzzy environment in which cost are represented by pentagonal intuitionistic fuzzy numbers. Transportation problem is a particular class of linear programming, which is associated with day to day activities in our real life. It helps in solving problems on distribution and transportation of resources from one place to another. The objective is to satisfy the demand at destination from the supply constraints at the minimum transportation cost possible. The problem is solved using a ranking technique called Accuracy function for pentagonal intuitionistic fuzzy numbers and Russell’s Method. An illustrative example is given to verify this approach.

  17. SOLVING RESOURCE-CONSTRAINED PROJECT SCHEDULING PROBLEMS WITH BI-CRITERIA HEURISTIC SEARCH TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    M Kamrul AHSAN; De-bi TSAO

    2003-01-01

    In this paper we formulate a bi-criteria search strategy of a heuristic learning algorithm for solving multiple resource-constrained project scheduling problems. The heuristic solves problems in two phases. In the pre-processing phase, the algorithm estimates distance between a state and the goal state and measures complexity of problem instances. In the search phase, the algorithm uses estimates of the pre-processing phase to further estimate distances to the goal state. The search continues in a stepwise generation of a series of intermediate states through search path evaluation process with backtracking. Developments of intermediate states are exclusively based on a bi-criteria new state selection technique where we consider resource utilization and duration estimate to the goal state. We also propose a variable weighting technique based on initial problem complexity measures. Introducing this technique allows the algorithm to efficiently solve complex project scheduling problems. A numerical example illustrates the algorithm and performance is evaluated by extensive experimentation with various problem parameters. Computational results indicate significance of the algorithm in terms of solution quality and computational performance.

  18. Problem-solving and developing quality management methods and techniques on the example of automotive industry

    Directory of Open Access Journals (Sweden)

    Jacek Łuczak

    2015-12-01

    Full Text Available The knowledge about methods and techniques of quality management together with their effective use can be definitely regarded as an indication of high organisational culture. Using such methods and techniques in an effective way can be attributed to certain level of maturity, as far as the quality management system in an organisation is concerned. There is in the paper an analysis of problem-solving methods and techniques of quality management in the automotive sector in Poland. The survey was given to the general population, which in case of the study consisted of companies operating in Poland that had certified quality management systems against ISO/TS 16949. The results of the conducted survey and the conclusions of the author can show actual and potential OEM suppliers (both 1st and 2nd tier in which direction their strategies for development and improvement of quality management systems should go in order to be effective. When the universal character of methods and techniques used in the surveyed population of companies is taken into consideration, it can be assumed that the results of the survey are also universal for all organisations realising the TQM strategy. The results of the research confirmed that methods which are also the basis for creating key system documents are the most relevant ones, i.e. flowcharts and FMEA, and moreover process monitoring tools (SPC and problem solving methods -above all 8D.

  19. A Study on Third Order Runge-Kutta Techniques for Solving Practical Problems

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    Sukumar SENTHILKUMAR

    2014-08-01

    Full Text Available In this paper, an analysis has been carried out to examine Nystrom third order, Heun third order and Classical Runge-Kutta third order methods to solve image processing and numerical problems which are demonstrated in brief. The methods adapted are fully capable to cope with the linearity and nonlinearity of the physical problems with versatile physical nature. Example problems and its corresponding results are exhibited which reveal the efficiency and reliability of the employed techniques. Furthermore, validity of an obtained solution is verified in comparison with the simulation output for an image processing problem and numerically computed results for an engineering problem and initial value problems.

  20. A special application of absolute value techniques in authentic problem solving

    Science.gov (United States)

    Stupel, Moshe

    2013-06-01

    There are at least five different equivalent definitions of the absolute value concept. In instances where the task is an equation or inequality with only one or two absolute value expressions, it is a worthy educational experience for learners to solve the task using each one of the definitions. On the other hand, if more than two absolute value expressions are involved, the definition that is most helpful is the one involving solving by intervals and evaluating critical points. In point of fact, application of this technique is one reason that the topic of absolute value is important in mathematics in general and in mathematics teaching in particular. We present here an authentic practical problem that is solved using absolute values and the 'intervals' method, after which the solution is generalized with surprising results. This authentic problem also lends itself to investigation using educational technological tools such as GeoGebra dynamic geometry software: mathematics teachers can allow their students to initially cope with the problem by working in an inductive environment in which they conduct virtual experiments until a solid conjecture has been reached, after which they should prove the conjecture deductively, using classic theoretical mathematical tools.

  1. An application of the multigrid technique to solve the pressure correction equation of incompressible flow

    Energy Technology Data Exchange (ETDEWEB)

    Miettinen, A.; Siikonen, T.

    1997-12-31

    An implementation of a multigrid technique to solve the pressure correction equation of incompressible flow is described. Two methods, full approximation storage (FAS) and multigrid (MG), were investigated and compared with a single level (SL) iteration technique. Only simple V-cycles were used. The solutions of the equations were always iterated by using the Gauss-Seidel method (GS). The grid of the test problem was 64 x 64, and the problem itself was a pressure correction problem of Driven Cavity Flow at Re=400. The CPU time needed to achieve the machine accuracy of the computer (Indigo 2 Workstation) was measured. The best achieved ratio between MG-GS and SL-GS was 1/145. When using a combination of the FAS technique and fixed V-cycles it was impossible to attain the machine accuracy. To reach the machine accuracy the FAS technique needs sensitive solution cycles, which makes the solver vulnerable. Thus it is recommended to use the MG technique, which can be easily developed after FAS implementation. (orig.) 9 refs.

  2. An improved iterative technique for solving nonlinear doubly singular two-point boundary value problems

    Science.gov (United States)

    Roul, Pradip

    2016-06-01

    This paper presents a new iterative technique for solving nonlinear singular two-point boundary value problems with Neumann and Robin boundary conditions. The method is based on the homotopy perturbation method and the integral equation formalism in which a recursive scheme is established for the components of the approximate series solution. This method does not involve solution of a sequence of nonlinear algebraic or transcendental equations for the unknown coefficients as in some other iterative techniques developed for singular boundary value problems. The convergence result for the proposed method is established in the paper. The method is illustrated by four numerical examples, two of which have physical significance: The first problem is an application of the reaction-diffusion process in a porous spherical catalyst and the second problem arises in the study of steady-state oxygen-diffusion in a spherical cell with Michaelis-Menten uptake kinetics.

  3. An element search ant colony technique for solving virtual machine placement problem

    Science.gov (United States)

    Srija, J.; Rani John, Rose; Kanaga, Grace Mary, Dr.

    2017-09-01

    The data centres in the cloud environment play a key role in providing infrastructure for ubiquitous computing, pervasive computing, mobile computing etc. This computing technique tries to utilize the available resources in order to provide services. Hence maintaining the resource utilization without wastage of power consumption has become a challenging task for the researchers. In this paper we propose the direct guidance ant colony system for effective mapping of virtual machines to the physical machine with maximal resource utilization and minimal power consumption. The proposed algorithm has been compared with the existing ant colony approach which is involved in solving virtual machine placement problem and thus the proposed algorithm proves to provide better result than the existing technique.

  4. Using reflection techniques for flexible problem solving (with examples from diagnosis)

    NARCIS (Netherlands)

    Teije, A. ten; Harmelen, van F.A.H.

    1996-01-01

    Flexible problem solving consists of the dynamic selection and configuration of problem solving methods for a particular problem type, depending on the particular problem and the goal of problem solving. In this paper, we propose an architecture that supports such flexible problem solving automatic

  5. Using reflection techniques for flexible problem solving (with examples from diagnosis)

    OpenAIRE

    Teije, A. ten; Harmelen, van, F.A.H.

    1996-01-01

    Flexible problem solving consists of the dynamic selection and configuration of problem solving methods for a particular problem type, depending on the particular problem and the goal of problem solving. In this paper, we propose an architecture that supports such flexible problem solving automatically. For this purpose, problem solving methods are described in a uniform way, by an abstract model of components, which together define the functionality of the methods. Such an abstract model is ...

  6. An analytical approximate technique for solving cubic–quintic Duffing oscillator

    Directory of Open Access Journals (Sweden)

    Md Abdur Razzak

    2016-09-01

    Full Text Available In this paper, an analytical approximate technique combined of homotopy perturbation method and variational formulation is presented to obtain the approximate frequency and the corresponding periodic solution of strongly nonlinear oscillator named as cubic–quintic Duffing oscillator. The first-order approximation is mainly considered in this paper. The solutions (first-order approximation are valid for both small and large amplitudes of oscillation. The main advantage of the present method is that its simplicity and straightforward. Moreover, the first-order approximate solution gives better result than other existing second, third and fourth-order approximations for all values of amplitude. The present method is more suitable for solving cubic–quintic Duffing oscillator than other existing methods.

  7. Optimal Algorithms and the BFGS Updating Techniques for Solving Unconstrained Nonlinear Minimization Problems

    Directory of Open Access Journals (Sweden)

    Chein-Shan Liu

    2014-01-01

    Full Text Available To solve an unconstrained nonlinear minimization problem, we propose an optimal algorithm (OA as well as a globally optimal algorithm (GOA, by deflecting the gradient direction to the best descent direction at each iteration step, and with an optimal parameter being derived explicitly. An invariant manifold defined for the model problem in terms of a locally quadratic function is used to derive a purely iterative algorithm and the convergence is proven. Then, the rank-two updating techniques of BFGS are employed, which result in several novel algorithms as being faster than the steepest descent method (SDM and the variable metric method (DFP. Six numerical examples are examined and compared with exact solutions, revealing that the new algorithms of OA, GOA, and the updated ones have superior computational efficiency and accuracy.

  8. The financial audit of companies operating in the metalworking industries

    Directory of Open Access Journals (Sweden)

    V. Grosu

    2012-10-01

    Full Text Available In light of the effects of the economic-financial crisis and of the numerous changes occurring both on a European and a global level and altering the environment of the metalworking sector, the aim of the present paper is to focus on the specific alterations performed in the audit of the economic and financial activity and of the financial statements of each entity under consideration. Moreover, high quality audit is essential, especially in light of the numerous cases of fraud and corruption that have been documented in the past few years – occurrences we make reference to – and involving companies operating in this particular sector.

  9. Comparison of Two Spatial Optimization Techniques: A Framework to Solve Multiobjective Land Use Distribution Problems

    Science.gov (United States)

    Meyer, Burghard Christian; Lescot, Jean-Marie; Laplana, Ramon

    2009-02-01

    Two spatial optimization approaches, developed from the opposing perspectives of ecological economics and landscape planning and aimed at the definition of new distributions of farming systems and of land use elements, are compared and integrated into a general framework. The first approach, applied to a small river catchment in southwestern France, uses SWAT (Soil and Water Assessment Tool) and a weighted goal programming model in combination with a geographical information system (GIS) for the determination of optimal farming system patterns, based on selected objective functions to minimize deviations from the goals of reducing nitrogen and maintaining income. The second approach, demonstrated in a suburban landscape near Leipzig, Germany, defines a GIS-based predictive habitat model for the search of unfragmented regions suitable for hare populations ( Lepus europaeus), followed by compromise optimization with the aim of planning a new habitat structure distribution for the hare. The multifunctional problem is solved by the integration of the three landscape functions (“production of cereals,” “resistance to soil erosion by water,” and “landscape water retention”). Through the comparison, we propose a framework for the definition of optimal land use patterns based on optimization techniques. The framework includes the main aspects to solve land use distribution problems with the aim of finding the optimal or best land use decisions. It integrates indicators, goals of spatial developments and stakeholders, including weighting, and model tools for the prediction of objective functions and risk assessments. Methodological limits of the uncertainty of data and model outcomes are stressed. The framework clarifies the use of optimization techniques in spatial planning.

  10. Comparison of two spatial optimization techniques: a framework to solve multiobjective land use distribution problems.

    Science.gov (United States)

    Meyer, Burghard Christian; Lescot, Jean-Marie; Laplana, Ramon

    2009-02-01

    Two spatial optimization approaches, developed from the opposing perspectives of ecological economics and landscape planning and aimed at the definition of new distributions of farming systems and of land use elements, are compared and integrated into a general framework. The first approach, applied to a small river catchment in southwestern France, uses SWAT (Soil and Water Assessment Tool) and a weighted goal programming model in combination with a geographical information system (GIS) for the determination of optimal farming system patterns, based on selected objective functions to minimize deviations from the goals of reducing nitrogen and maintaining income. The second approach, demonstrated in a suburban landscape near Leipzig, Germany, defines a GIS-based predictive habitat model for the search of unfragmented regions suitable for hare populations (Lepus europaeus), followed by compromise optimization with the aim of planning a new habitat structure distribution for the hare. The multifunctional problem is solved by the integration of the three landscape functions ("production of cereals," "resistance to soil erosion by water," and "landscape water retention"). Through the comparison, we propose a framework for the definition of optimal land use patterns based on optimization techniques. The framework includes the main aspects to solve land use distribution problems with the aim of finding the optimal or best land use decisions. It integrates indicators, goals of spatial developments and stakeholders, including weighting, and model tools for the prediction of objective functions and risk assessments. Methodological limits of the uncertainty of data and model outcomes are stressed. The framework clarifies the use of optimization techniques in spatial planning.

  11. Design of a novel cloud-based metalworking supplier matching system

    Directory of Open Access Journals (Sweden)

    Shang-Liang Chen

    2016-12-01

    Full Text Available Traditionally, machine equipment manufacturers match new metalworking suppliers through yellow pages and websites, which is inefficient and not timely for supplier information transfer. In this article, a cloud-based supplier matching system is proposed to offer machine equipment manufacturers an efficient way to match suitable metalworking suppliers. A cloud architecture to enhance utilization of servers and simplified device management is designed. Two cloud services are designed in this system, including order-bidding service and order-cooperation service. A comparison result shows that the system can provide a flexible matching system for both metalworking suppliers and machine equipment manufacturers.

  12. SOLVING THE STUDENTS’ SPEAKING PROBLEM IN DELIVERING ENGLISH PRESENTATION THROUGH 3-P TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Nadif Ulfia

    2017-01-01

    Full Text Available Abstract: Solving the Students’ Speaking Problem in Delivering English Presentation Through 3-P Technique. The aims of this study were to (1 identify whether and to what extent 3-P Technique can improve the students’ speaking competence in delivering presentation;(2 describe the teaching and learning when 3-P technique is implemented in English class. This research was conducted at the eleventh grades of MAN 1 Bojonegoro. The subjects of the research were the teacher and the students in the academic year 2016/2017. This study applied 3 cycle action research. In collecting the data, the researcher used observations through field notes, video recording, questionnaire and interview. To analyze the quantitative data, the researcher applied descriptive statistics. Besides, to analyze qualitative data, the researcher applied constant comparative method as suggested by Garner. The findings shows that: (1 3-P Technique can improve students’ speaking competence in delivering presentation in terms of students achievement, fluency, pronunciation, ability to express their opinions, arguments, and ideas using appropriate vocabulary and grammatical form, using appropriate body language, voice control, gesture, and eye contact; and (2 3-P technique can improve classroom situation in terms of increasing students’ motivation and participation, creating live teaching atmosphere, and increasing teacher motivation. Key words: Speaking, 3 P technique, Action research Abstrak: Memecahkan Masalah Keterampilan Berbicara Siswa dalam Menyampaikan Presentasi Berbahasa Inggris Melalui Teknik 3-P. Tujuan dari penelitian ini adalah untuk (1 mengidentifikasi dan mengetahui sejauh mana teknik 3-P dapat meningkatkan kemampuan berbicara para siswa dalam menyampaikan sebuah presentasi; (2 mendeskripsikan kegiatan pembelajaran dalam penerapan teknik 3-P dalam pembelajaran Bahasa Inggris. Penelitian ini dilakukan pada kelas sebelas MAN 1 Bojonegoro. Subyek  penelitian ini

  13. The Davidon-Fletcher-Powell penalty function method: A generalized iterative technique for solving parameter optimization problems

    Science.gov (United States)

    Johnson, I. L., Jr.

    1976-01-01

    The Fletcher-Powell version of the Davidon variable metric unconstrained minimization technique is described. Equations that have been used successfully with the Davidon-Fletcher-Powell penalty function technique for solving constrained minimization problems and the advantages and disadvantages of using them are discussed. The experience gained in the behavior of the method while iterating is also related.

  14. Solving real decay and conservation problems of building materials by ultrasounds technique

    Science.gov (United States)

    Alvarez de Buergo, Monica; Fort, Rafael; Gomez-Heras, Miguel; Vazquez-Calvo, Carmen

    2010-05-01

    In this study a variety of case studies and different building materials in which ultrasounds velocity played a significant role are shown, either to characterize building materials, to measure deterioration, to assess conservation techniques or for preventive purposes. Regarding to materials properties, ultrasounds velocity provided interesting indices such as the quality index (useful when selecting replacing materials, materials for new constructions or either for sculptures); alteration index (very much related to pores and voids, and fissures); mechanical strength (assessing its reduction when materials are affected by several decay processes, being fire one of them) or anisotropy indices, which highly condition the decay of elements and materials in buildings and sculptures, and which vary themselves with decay progress. The technique is also a tool for detecting and locating elements inside structures, like metallic ones, and also to detect and locate discontinuities inside elements, both for consolidation purposes or even in cases of structures movement, which is quite common nowadays. Using some specific software, ultrasounds results can be plotted as iso-areas, which allows to define areas or zones of structures with the highest risk of detachment in a short-time in order to plan the most adequate interventions. Not new is also the aid of ultrasonics to assess consolidation products and to determine the degree of materials decay when submitted to artificial ageing. Much more innovative is the fact that ultrasonics measurement can be also helpful to determine different building periods in a same building, even the fact of determining an element's lifetime. The results obtained by this non destructive and portable technique that will be presented in this session correspond to both real case studies (results that helped to solve a real problem), some of them corresponding to emblematic monuments de España (Royal Palace of Madrid and some other monuments

  15. Adenomyosis: usual and unusual imaging manifestations, pitfalls, and problem-solving MR imaging techniques.

    Science.gov (United States)

    Takeuchi, Mayumi; Matsuzaki, Kenji

    2011-01-01

    Adenomyosis is a common nonneoplastic gynecologic disease characterized by the presence of ectopic endometrium within the myometrium. On T2-weighted magnetic resonance (MR) images, typical adenomyosis appears as an ill-demarcated low-signal-intensity lesion with uterine enlargement. However, various physiologic or pathologic states such as amount of functional endometrial tissue, phase of the menstrual cycle, endogenous hormonal abnormality, and exogenous hormonal stimulation may affect the MR imaging appearance of adenomyosis and may result in a tumorlike appearance. Problem-solving MR imaging techniques used in diagnosis of adenomyosis include diffusion-weighted imaging, susceptibility-weighted imaging, hydrogen 1 MR spectroscopy, cine MR imaging, and high-resolution MR imaging at 3 T. Adenomyotic lesions that show high signal intensity relative to the outer myometrium on T2-weighted images mimic malignancies such as leiomyosarcoma and endometrial stromal sarcoma. In these cases, a relatively high apparent diffusion coefficient at diffusion-weighted imaging and a low choline peak at MR spectroscopy are suggestive of a benign lesion. Small hemorrhagic foci suggestive of an adenomyotic lesion are well demonstrated as signal voids at susceptibility-weighted imaging. Cine MR imaging is useful in differentiating transient myometrial contraction from focal adenomyosis. High-resolution MR imaging at 3 T demonstrates anatomically detailed structures and may improve diagnostic accuracy in differentiating adenomyosis from its mimics, such as low-grade endometrial stromal sarcoma.

  16. PROBLEM SOLVING TECHNIQUES AS A PART OF IMPLEMENTATION OF SIX SIGMA METHODOLOGY IN TIRE PRODUCTION. CASE STUDY

    Directory of Open Access Journals (Sweden)

    Maciej WOJTASZAK

    2015-07-01

    Full Text Available Problem solving methods – are an indispensable part of the management and improvement of production. At the turn of decades, with the development of industry, specific techniques have been implemented and refined by the leaders in this field, such as Toyota, GE and Motorola. The foundation of problem solving is to find real root cause of the problem as soon as possible, its understanding and implementation of appropriate solutions that will ensure that the problem does not occur again. This paper provides an overview of methods and techniques to solve problems in the manufactur-ing plant Trelleborg Wheel Systems Sri Lanka, producing pneumatic tires for light agricultural machinery. These tech-niques are implemented as part of the Lean Six Sigma program.

  17. The effects of using diagramming as a representational technique on high school students' achievement in solving math word problems

    Science.gov (United States)

    Banerjee, Banmali

    Methods and procedures for successfully solving math word problems have been, and continue to be a mystery to many U.S. high school students. Previous studies suggest that the contextual and mathematical understanding of a word problem, along with the development of schemas and their related external representations, positively contribute to students' accomplishments when solving word problems. Some studies have examined the effects of diagramming on students' abilities to solve word problems that only involved basic arithmetic operations. Other studies have investigated how instructional models that used technology influenced students' problem solving achievements. Still other studies have used schema-based instruction involving students with learning disabilities. No study has evaluated regular high school students' achievements in solving standard math word problems using a diagramming technique without technological aid. This study evaluated students' achievement in solving math word problems using a diagramming technique. Using a quasi-experimental experimental pretest-posttest research design, quantitative data were collected from 172 grade 11 Hispanic English language learners (ELLS) and African American learners whose first language is English (EFLLs) in 18 classes at an inner city high school in Northern New Jersey. There were 88 control and 84 experimental students. The pretest and posttest of each participating student and samples of the experimental students' class assignments provided the qualitative data for the study. The data from this study exhibited that the diagramming method of solving math word problems significantly improved student achievement in the experimental group (pvocabulary and symbols used in word problems and that both ELLs and EFLLs improved their problem solving success through careful attention to the creation and labeling of diagrams to represent the mathematics involved in standard word problems. Although Learnertype (ELL, EFLL

  18. Skin absorption of six performance amines used in metalworking fluids.

    Science.gov (United States)

    Roux, Lauriane N; Brooks, James D; Yeatts, James L; Baynes, Ronald E

    2015-05-01

    Every year, 10 million workers are exposed to metalworking fluids (MWFs) that may be toxic. There are four types of MWFs: neat oils and three water-based MWFs (soluble oil, semisynthetic and synthetic), which are diluted with water and whose composition varies according to the mineral oils ratio. MWFs also contain various additives. To determine the absorption of six amines used as corrosion inhibitors and biocides in MWFs, porcine skin flow-through diffusion cell experiments were conducted with hydrophilic ethanolamines (mono-, di- and triethanolamine, MEA, DEA and TEA respectively) and a mixture of lipophilic amines (dibutylethanolamine, dicyclohexylamine and diphenylamine). The six amines were dosed in four vehicles (water and three generic water-based MWF formulations) and analyzed using a scintillation counter or gas chromatography/mass spectrometry. These 24 h studies showed that dermal absorption significantly (P < 0.05) increased from water for the six amines (e.g. 1.15 ± 0.29% dose; DEA in water) compared to other formulations (e.g. 0.13 ± 0.01% dose; DEA in semisynthetic MWF) and absorption was greatest for dibutylethanolamine in all the formulations. The soluble oil formulation tended to increase the dermal absorption of the hydrophilic amines. The permeability coefficient was significantly higher (P < 0.05) with TEA relative to the other hydrophilic amines (e.g. 4.22 × 10(-4) ± 0.53 × 10(-4) cm h(-1) [TEA in synthetic MWF] vs. 1.23 × 10(-4) ± 0.10 × 10(-4) cm h(-1) [MEA in synthetic MWF]), except for MEA in soluble oil formulation. Future research will confirm these findings in an in vivo pig model along with dermatotoxicity studies. These results should help MWF industries choose safer additives for their formulations to protect the health of metalworkers. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Predicting Academic Success of Junior Secondary School Students in Mathematics through Cognitive Style and Problem Solving Technique

    Science.gov (United States)

    Badru, Ademola K.

    2015-01-01

    This study examined the prediction of academic success of Junior secondary school mathematics students using their cognitive style and problem solving technique. A descriptive survey of correlation type was adopted for this study. A purposive sampling procedure was used to select five Public Junior secondary schools in Ijebu-Ode local government…

  20. A double smoothing technique for solving unconstrained nondifferentiable convex optimization problems

    CERN Document Server

    Bot, Radu Ioan

    2012-01-01

    The aim of this paper is to develop an efficient algorithm for solving a class of unconstrained nondifferentiable convex optimization problems in finite dimensional spaces. To this end we formulate first its Fenchel dual problem and regularize it in two steps into a differentiable strongly convex one with Lipschitz continuous gradient. The doubly regularized dual problem is then solved via a fast gradient method with the aim of accelerating the resulting convergence scheme. The theoretical results are finally applied to an l1 regularization problem arising in image processing.

  1. A novel technique to solve nonlinear higher-index Hessenberg differential-algebraic equations by Adomian decomposition method.

    Science.gov (United States)

    Benhammouda, Brahim

    2016-01-01

    Since 1980, the Adomian decomposition method (ADM) has been extensively used as a simple powerful tool that applies directly to solve different kinds of nonlinear equations including functional, differential, integro-differential and algebraic equations. However, for differential-algebraic equations (DAEs) the ADM is applied only in four earlier works. There, the DAEs are first pre-processed by some transformations like index reductions before applying the ADM. The drawback of such transformations is that they can involve complex algorithms, can be computationally expensive and may lead to non-physical solutions. The purpose of this paper is to propose a novel technique that applies the ADM directly to solve a class of nonlinear higher-index Hessenberg DAEs systems efficiently. The main advantage of this technique is that; firstly it avoids complex transformations like index reductions and leads to a simple general algorithm. Secondly, it reduces the computational work by solving only linear algebraic systems with a constant coefficient matrix at each iteration, except for the first iteration where the algebraic system is nonlinear (if the DAE is nonlinear with respect to the algebraic variable). To demonstrate the effectiveness of the proposed technique, we apply it to a nonlinear index-three Hessenberg DAEs system with nonlinear algebraic constraints. This technique is straightforward and can be programmed in Maple or Mathematica to simulate real application problems.

  2. Problem Solving: Tools and Techniques for the Park and Recreation Administrator. Fourth Edition

    Science.gov (United States)

    Arnold, Margaret L.; Heyne, Linda A.; Busser, James A.

    2005-01-01

    This book is a useful tool for recreation educators in carrying out their responsibilities for preparing the next generation for effective service in recreation and parks. The need for this book is apparent, because few recreation curricula include courses in problem solving. It is true that many texts dealing with recreation describe policies and…

  3. Improving Problem-Solving Techniques for Students in Low-Performing Schools

    Science.gov (United States)

    Hobbs, Robert Maurice

    2012-01-01

    Teachers can use culturally relevant pedagogical strategies and technologies as emerging tools to improve students' problem-solving skills. The purpose of this study was to investigate and assess the effectiveness of culturally specific computer-based instructional tasks on ninth-grade African American mathematics students. This study tried to…

  4. Using Interactive Problem-Solving Techniques to Enhance Control Systems Education for Non English-Speakers

    Science.gov (United States)

    Lamont, L. A.; Chaar, L.; Toms, C.

    2010-01-01

    Interactive learning is beneficial to students in that it allows the continual development and testing of many skills. An interactive approach enables students to improve their technical capabilities, as well as developing both verbal and written communicative ability. Problem solving and communication skills are vital for engineering students; in…

  5. A Special Application of Absolute Value Techniques in Authentic Problem Solving

    Science.gov (United States)

    Stupel, Moshe

    2013-01-01

    There are at least five different equivalent definitions of the absolute value concept. In instances where the task is an equation or inequality with only one or two absolute value expressions, it is a worthy educational experience for learners to solve the task using each one of the definitions. On the other hand, if more than two absolute value…

  6. Authenticity of Benin metalworks evaluated by inductively coupled plasma mass spectrometry and lead isotope analyses

    Science.gov (United States)

    Fabbri, E.; Soffritti, C.; Merlin, M.; Vaccaro, C.; Garagnani, G. L.

    2017-05-01

    Two metal plaques and a cock statuette belonging to a private collection and stylistically consistent with the Royal Art of Benin (Nigeria) were investigated in order to verify their authenticity. The characterization of alloys and patinas were carried out by inductively coupled plasma mass spectrometry, optical microscopy, scanning electron microscopy and energy dispersion spectroscopy, and X-Ray diffraction spectrometry. Furthermore, thermal ionization mass spectrometry was used to assess the abundances of lead isotopes and to attempt a dating by the measurement of 210Pb/204Pb ratio. The results showed that all three artefacts were mainly composed of low lead-brass alloys, with relatively high concentrations of zinc, antimony, cadmium and aluminum in the solid copper solution. Microstructures were mostly dendritic, typical of as-cast brasses, and characterized by recrystallized non-homogeneous twinned grains in areas corresponding to surface decorations, probably due to multiple hammering steps followed by partial annealing treatments. The matrix was composed of a cored α-Cu solid solution together with non-metallic inclusions, lead globules and Sn-rich precipitates in interdendritic spaces. On the surface of all metalworks, both copper and zinc oxides, a non-continuous layer of sulphur-containing contaminants and chloride-containing compounds, were identified. The lead isotope results were consistent with brasses produced shortly before or after 1900 CE. Overall, the data obtained by different techniques supported the hypothesis that the three artefacts were not authentic.

  7. Potential pathogenic bacteria in metalworking fluids and aerosols from a machining facility.

    Science.gov (United States)

    Perkins, Sarah D; Angenent, Largus T

    2010-12-01

    The metalworking and machining industry utilizes recirculating metalworking fluids for integral aspects of the fabrication process. Despite the use of biocides, these fluids sustain substantial biological growth. Subsequently, the high-shear forces incurred during metalworking processing aerosolize bacterial cells and may cause dermatologic and respiratory effects in exposed workers. We quantified and identified the bacterial load for metalworking fluid and aerosol samples of a machining facility in the US Midwest during two seasons. To investigate the presence of potentially pathogenic bacteria in fluid and air, we performed 16S rRNA gene surveys. The concentration of total bacterial cells (including culturable and nonculturable cells) was relatively constant throughout the study, averaging 5.1 × 10⁸ cells mL⁻¹ in the fluids and 4.8 × 10⁵ cells m⁻³ in the aerosols. We observed bacteria of potential epidemiologic significance from several different bacterial phyla in both fluids and aerosols. Most notably, Alcaligenes faecalis was identified through both direct sequencing and culturing in every sample collected. Elucidating the bacterial community with gene surveys showed that metalworking fluids were the source of the aerosolized bacteria in this facility.

  8. Rapid Vaporization of Thin Conductors Used for Impulse Metalworking

    Science.gov (United States)

    Vivek, Anupam

    Forming, cutting and welding of metal by impulse has significant advantages, in that short time scales change the fundamental nature of the forming process and short duration impulses can be used with much lighter and more agile equipment because large static forces do not need to be resisted. Impulse metalworking is commonly implemented using explosives or electromagnetic actuators. Explosives have limitations such as space requirements, handling and storage restrictions and ability to scale down the process. The application of electromagnetic forming is limited at high energies and large numbers of operations by the availability of long-lived electromagnetic coils (or actuators, as they are sometimes referred to). Here low-cost, disposable actuators have been suggested as one method to treat this issue. Forming, cutting and welding of metal by impulse has significant advantages, in that short time scales change the fundamental nature of the forming process and short duration impulses can be used with much lighter and more agile equipment because large static forces do not need to be resisted. Impulse metalworking is commonly implemented using explosives or electromagnetic actuators. Explosives have limitations such as space requirements, handling and storage restrictions and ability to scale down the process. The application of electromagnetic forming is limited at high energies and large numbers of operations by the availability of long-lived electromagnetic coils (or actuators, as they are sometimes referred to). Here low-cost, disposable actuators have been suggested as one method to treat this issue. Applications including cutting, forming, axisymmetric joining and collision welding are demonstrated and discussed. From analysis of the data from these applications, it was seen that degree of confinement has a great effect on effective geometries of a vaporizing foil. With less confinement, thicker foils were found to be more efficient whereas thinner foils

  9. Intuitionistic Fuzzy Goal Programming Technique for Solving Non-Linear Multi-objective Structural Problem

    Directory of Open Access Journals (Sweden)

    Samir Dey

    2015-07-01

    Full Text Available This paper proposes a new multi-objective intuitionistic fuzzy goal programming approach to solve a multi-objective nonlinear programming problem in context of a structural design. Here we describe some basic properties of intuitionistic fuzzy optimization. We have considered a multi-objective structural optimization problem with several mutually conflicting objectives. The design objective is to minimize weight of the structure and minimize the vertical deflection at loading point of a statistically loaded three-bar planar truss subjected to stress constraints on each of the truss members. This approach is used to solve the above structural optimization model based on arithmetic mean and compare with the solution by intuitionistic fuzzy goal programming approach. A numerical solution is given to illustrate our approach.

  10. Reflective discourse techniques: From in-class discussions to out-of-classroom problem solving

    Science.gov (United States)

    Wampler, Wendi; Demaree, Dedra; Gilbert, Dennis

    2013-01-01

    Instructors often give prompts that encourage students to articulate their beliefs and conceptions, as well as encourage students to understand the thoughts of their peers. This reflective discourse is used in a calculus-based introductory physics class at Lane Community College, where the instructor explicitly has discourse goals integrated into his course structure. We investigate whether students utilize this discourse when solving problems outside of the classroom context. We interviewed groups of students after the end of spring term, 2012. The students were asked to solve open-ended problems, with analysis focused on whether students applied this reflective discourse. Students were asked a series of follow-up questions to reflect upon their experiences in the course.

  11. EQUILIBRIUM ALGORITHMS WITH NONMONOTONE LINE SEARCH TECHNIQUE FOR SOLVING THE TRAFFIC ASSIGNMENT PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hui; GAO Ziyou

    2005-01-01

    This paper presents a unified framework of the nonmonotone convex combination algorithms (such as Frank-Wolfe Algorithm) for solving the traffic assignment problems. Global convergence results are established under mild conditions. The line search procedure used in our algorithm includes the nonmonotone Armijo rule, the nonmonotone Goldstein rule and the nonmonotone Wolfe rule as special cases. So, the new algorithm can be viewed as a generalization of the regular convex combination algorithm.

  12. Modeling State Space Search Technique for a Real World Adversarial Problem Solving

    Directory of Open Access Journals (Sweden)

    Kester O. Omoregie

    2015-02-01

    Full Text Available In problem solving, there is a search for the appropriate solution. A state space is a problem domain consisting of the start state, the goal state and the operations that will necessitate the various moves from the start state to the goal state. Each move operation takes one away from the start state and closer to the goal state. In this work we have attempted implementing this concept in adversarial problem solving, which is a more complex problem space. We noted that real world adversarial problems vary in their types and complexities, and therefore solving an adversarial problem would depend on the nature of the adversarial problem itself. Specifically, we examined a real world case, "the prisoner's dilemma" which is a critical, mutually independent, decision making adversarial problem. We combined the idea of the Thagard's Theory of Explanatory Coherence (TEC with Bayes' theorem of conditional probability to construct the model of an opponent that includes the opponent's model of the agent. A further conversion of the model into a series of state space structures led us into the use of breadth-first search strategy to arrive at our decision goal.

  13. An efficient technique to solve combined economic and emission dispatch problem using modified Ant colony optimization

    Indian Academy of Sciences (India)

    R Gopalakrishnan; A Krishnan

    2013-08-01

    Economic load dispatch is one of the vital purposes in electrical power system operation, management and planning. Economic dispatch problem is one of the most important problems in electric power system operation. In large scale system, the problem is more complex and difficult to find out optimal solution because it is nonlinear function and it contains number of local optimal. Combined economic emission dispatch (CEED) problem is to schedule the committed generating units outputs to meet the required load demand at minimum operating cost with minimum emission simultaneously. The main aim of economic load dispatch is to reduce the total production cost of the generating system and at the same time the necessary equality and inequality constraints should also be fulfilled. This leads to the development of CEED techniques. There are various techniques proposed by several researchers to solve CEED problem based on optimization techniques. But still some problems such as slower convergence and higher computational complexity exist in using the optimization techniques such as GA for solving CEED problem. This paper proposes an efficient and reliable technique for combined fuel cost economic optimization and emission dispatch using the Modified Ant Colony Optimization algorithm (MACO) to produce better optimal solution. The simulation results reveal the significant performance of the proposed MACO approach.

  14. Cobalt asthma in metalworkers from an automotive engine valve manufacturer.

    Science.gov (United States)

    Walters, G I; Robertson, A S; Moore, V C; Burge, P S

    2014-07-01

    Cobalt asthma has previously been described in cobalt production workers, diamond polishers and glassware manufacturers. To describe a case series of occupational asthma (OA) due to cobalt, identified at the Birmingham Heartlands Occupational Lung Disease Unit, West Midlands, UK. Cases of cobalt asthma from a West Midlands' manufacturer of automotive engine valves, diagnosed between 1996 and 2005, were identified from the SHIELD database of OA. Case note data on demographics, employment status, asthma symptoms and diagnostic tests, including spirometry, peak expiratory flow (PEF) measurements, skin prick testing (SPT) and specific inhalational challenge (SIC) tests to cobalt chloride, were gathered, and descriptive statistics used to illustrate the data. The natural history of presentations has been described in detail, as well as a case study of one of the affected workers. Fourteen metalworkers (86% male; mean age 44.9 years) were diagnosed with cobalt asthma between 1996 and 2005. Workers were principally stellite grinders, stellite welders or machine setter-operators. All workers had positive Occupational Asthma SYStem analyses of serial PEF measurements, and sensitization to cobalt chloride was demonstrated in nine workers, by SPT or SIC. We have described a series of 14 workers with cobalt asthma from the automotive manufacturing industry, with objective evidence for sensitization. Health care workers should remain vigilant for cobalt asthma in the automotive manufacturing industry. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Respiratory exposure to components of water-miscible metalworking fluids.

    Science.gov (United States)

    Suuronen, Katri; Henriks-Eckerman, Maj-Len; Riala, Riitta; Tuomi, Timo

    2008-10-01

    Water-miscible metalworking fluids (MWFs) are capable of causing respiratory symptoms and diseases. Recently, much emphasis has been put on developing new methods for assessing respiratory exposure to MWF emulsions. The air concentrations of ingredients and contaminants of MWF and inhalable dust were measured in 10 metal workshops in southern Finland. Oil mist was determined by infra red spectroscopy analysis after tetrachloroethylene extraction from the filter. Aldehydes were collected on Sep-Pak chemosorbents and analysed by liquid chromatography. Volatile organic compounds (VOCs) were collected on Tenax adsorbents and analysed by gas chromatography with mass spectrometric detection after thermal desorption. Endotoxins were collected on glass fibre filter and analysed by enzyme-based spectrophotometry, and viable microbes were collected on polycarbonate filter and cultured. Inhalable dust was collected on cellulose acetate filter and quantified gravimetrically. Associations between the different exposures were calculated with Spearman's correlations. The mean concentration of oil mist was 0.14 (range aliphatic hydrocarbons. Several potential sensitizing chemicals such as terpenes were found in small quantities. The concentration of microbial contaminants was low. All the measured air concentrations were below the Finnish occupational exposure limits. The exposure in machine shops was quantitatively dominated by volatile compounds. Additional measurements of MWF components such as aldehydes, alkanolamines and VOCs are needed to get more information on the chemical composition of workshops' air. New air cleaning methods should be introduced, as oil mist separators are insufficient to clean the air of small molecular impurities.

  16. An efficient and simple approximate technique for solving nonlinear initial and boundary-value problems

    Science.gov (United States)

    Kounadis, A. N.

    1992-05-01

    An efficient and easily applicable, approximate analytic technique for the solution of nonlinear initial and boundary-value problems associated with nonlinear ordinary differential equations (O.D.E.) of any order and variable coefficients, is presented. Convergence, uniqueness and upper bound error estimates of solutions, obtained by the successive approximations scheme of the proposed technique, are thoroughly established. Important conclusions regarding the improvement of convergence for large time and large displacement solutions in case of nonlinear initial-value problems are also assessed. The proposed technique is much more efficient than the perturbations schemes for establishing the large postbuckling response of structural systems. The efficiency, simplicity and reliability of the proposed technique is demonstrated by two illustrative examples for which available numerical results exist.

  17. Distributed-parameter problem solved on a hybrid computer by a modified function storage technique

    DEFF Research Database (Denmark)

    Poulsen, N.J.

    1969-01-01

    Describes a method which is based on a function storage technique improved by a number of modifications; it fulfils the two main demands: the solution is based directly on the physical equations, and is accurate within 1%......Describes a method which is based on a function storage technique improved by a number of modifications; it fulfils the two main demands: the solution is based directly on the physical equations, and is accurate within 1%...

  18. Solving the transport without transit quantum paradox of the spatial adiabatic passage technique

    CERN Document Server

    Benseny, Albert; Oriols, Xavier; Mompart, Jordi

    2011-01-01

    We discuss and solve the transport without transit quantum paradox recently introduced in the context of the adiabatic transport of a single particle or a Bose--Einstein condensate between the two extreme traps of a triple-well potential. To this aim, we address the corresponding quantum dynamics in terms of Bohmian trajectories and show that transport always implies transit through the middle well, in full agreement with the quantum continuity equation. This adiabatic quantum transport presents a very counterintuitive effect: by slowing down the total time duration of the transport process, ultra-high Bohmian velocities are achieved such that, in the limit of perfect adiabaticity, relativistic corrections are needed to properly address the transfer process while avoiding superluminal matter wave propagation.

  19. On applying weighted seed techniques to GMRES algorithm for solving multiple linear systems

    Directory of Open Access Journals (Sweden)

    Lakhdar Elbouyahyaoui

    2018-07-01

    Full Text Available In the present paper, we are concerned by weighted Arnoldi like methods for solving large and sparse linear systems that have different right-hand sides but have the same coefficient matrix. We first give detailed descriptions of the weighted Gram-Schmidt process and of a Ruhe variant of the weighted block Arnoldi algorithm. We also establish some theoretical results that links the iterates of the weighted block Arnoldi process to those of the non weighted one. Then, to accelerate the convergence of the classical restarted block and seed GMRES methods, we introduce the weighted restarted block and seed GMRES methods. Numerical experiments that are done with different matrices coming from the Matrix Market repository or from the university of Florida sparse matrix collection are reported at the end of this work in order to compare the performance and show the effectiveness of the proposed methods.

  20. The constructive technique and its application in solving a nonlinear reaction diffusion equation

    Institute of Scientific and Technical Information of China (English)

    Lai Shao-Yong; Guo Yun-Xi; Qing Yin; Wu Yong-Hong

    2009-01-01

    A mathematical technique based on the consideration of a nonlinear partial differential equation together with an additional condition in the form of an ordinary differential equation is employed to study a nonlinear reaction diffusion equation which describes a real process in physics and in chemistry. Several exact solutions for the equation are acquired under certain circumstances.

  1. Overview of Some New Techniques for Inspection: Using 1950's Physics to Solve Modern Problems

    Science.gov (United States)

    Lanza, Richard

    2007-04-01

    The goal of any inspection technique is to non-intrusively determine the presence of such materials in a manner which is consistent with not interrupting the normal scheme of commerce and which, at the same time, exhibits a high probability of detection and a low probability of false alarms. A great deal of work has been reported in the literature on neutron based techniques for the detection of explosives with by far the largest impetus coming from the requirements of the commercial aviation industry for the inspection of luggage and, to a lesser extent, cargo; for baggage, the major techniques are either x-ray based or are chemical trace detection methods which look for small traces of explosive residues. Nuclear techniques have been proposed for the detection of explosives and contraband for a number of years due to their ability to penetrate shielding and to identify the elemental composition of materials, thus leading to enhanced detection probability and lower false alarm rates. Nuclear techniques are virtually the only method which can both detect and identify the presence of fissile materials, either in the form of bulk material or assembled weapons. Some examples of current work in nuclear based systems currently under development will be discussed such as nuclear resonance radiography, nuclear resonance fluorescence, pulsed fast neutron analysis and pulsed photonuclear detection. The physical basis of these techniques is well known, the physics having been studied in the 1950's, but there remain limitations on current technology with respect to e.g. radiation sources and detectors and data acquisition methods. Accelerator-based systems often are large and are often not well suited for field use; radiation detectors often suffer from limited count rate ability, low sensitivity and poor energy resolution and data acquisition and analysis methods usually rely on analog techniques which are not always stable in field operation. Current research in basic

  2. Using interactive problem-solving techniques to enhance control systems education for non English-speakers

    Science.gov (United States)

    Lamont, L. A.; Chaar, L.; Toms, C.

    2010-03-01

    Interactive learning is beneficial to students in that it allows the continual development and testing of many skills. An interactive approach enables students to improve their technical capabilities, as well as developing both verbal and written communicative ability. Problem solving and communication skills are vital for engineering students; in the workplace they will be required to communicate with people of varying technical abilities and from different linguistic and engineering backgrounds. In this paper, a case study is presented that discusses how the traditional method of teaching control systems can be improved. 'Control systems' is a complex engineering topic requiring students to process an extended amount of mathematical formulae. MATLAB software, which enables students to interactively compare a range of possible combinations and analyse the optimal solution, is used to this end. It was found that students became more enthusiastic and interested when given ownership of their learning objectives. As well as improving the students' technical knowledge, other important engineering skills are also improved by introducing an interactive method of teaching.

  3. DATA MINING WORKSPACE AS AN OPTIMIZATION PREDICTION TECHNIQUE FOR SOLVING TRANSPORT PROBLEMS

    Directory of Open Access Journals (Sweden)

    Anastasiia KUPTCOVA

    2016-09-01

    Full Text Available This article addresses the study related to forecasting with an actual high-speed decision making under careful modelling of time series data. The study uses data-mining modelling for algorithmic optimization of transport goals. Our finding brings to the future adequate techniques for the fitting of a prediction model. This model is going to be used for analyses of the future transaction costs in the frontiers of the Czech Republic. Time series prediction methods for the performance of prediction models in the package of Statistics are Exponential, ARIMA and Neural Network approaches. The primary target for a predictive scenario in the data mining workspace is to provide modelling data faster and with more versatility than the other management techniques.

  4. A subspace shift technique for solving close-to-critical nonsymmetric algebraic Riccati equations

    CERN Document Server

    Iannazzo, Bruno

    2010-01-01

    The worst situation in computing the minimal nonnegative solution $X_*$ of a nonsymmetric algebraic Riccati equation $\\mathcal R(X)=0$ associated with an M-matrix occurs when the derivative of $\\mathcal R$ at $X_*$ is near to a singular matrix. When the derivative of $\\mathcal R$ at $X_*$ is singular, the problem is ill-conditioned and the convergence of the algorithms based on matrix iterations is slow; however, there exist some techniques to remove the singularity and restore well-conditioning and fast convergence. This phenomenon is partially shown also in the close-to-critical case, but the techniques used for the null recurrent case cannot be applied to this setting. We present a new method to accelerate the convergence and amend the conditioning in close-to-critical cases. The numerical experiments confirm the efficiency of the new method.

  5. An analytical approximate technique for solving cubic–quintic Duffing oscillator

    OpenAIRE

    Md. Abdur Razzak

    2016-01-01

    In this paper, an analytical approximate technique combined of homotopy perturbation method and variational formulation is presented to obtain the approximate frequency and the corresponding periodic solution of strongly nonlinear oscillator named as cubic–quintic Duffing oscillator. The first-order approximation is mainly considered in this paper. The solutions (first-order approximation) are valid for both small and large amplitudes of oscillation. The main advantage of the present method i...

  6. Solving radiative transfer problems in highly heterogeneous media via domain decomposition and convergence acceleration techniques.

    Science.gov (United States)

    Previti, Alberto; Furfaro, Roberto; Picca, Paolo; Ganapol, Barry D; Mostacci, Domiziano

    2011-08-01

    This paper deals with finding accurate solutions for photon transport problems in highly heterogeneous media fastly, efficiently and with modest memory resources. We propose an extended version of the analytical discrete ordinates method, coupled with domain decomposition-derived algorithms and non-linear convergence acceleration techniques. Numerical performances are evaluated using a challenging case study available in the literature. A study of accuracy versus computational time and memory requirements is reported for transport calculations that are relevant for remote sensing applications.

  7. Metalworking defects in surgery screws as a possible cause of post-surgical infections

    Science.gov (United States)

    Spector, Mario; Peretti, Leandro E.; Romero, Gustavo

    2016-04-01

    In the first phase of this work, surface defects (metalworking) in stainless steel implantable prostheses and their possible relation to infections that can be generated after surgery was studied. In a second phase, the results obtained in the aforementioned stage were applied to knee cruciate ligaments surgery screws, considering the fact that a substantial number of Mucormycetes infections have been reported after arthroscopic surgery in Argentina since the year 2005. Two types of screws, transverse and interference screws, were analyzed. The Allen heads presented defects such as burrs and metalworking bending as a result of the machining process. These defects allow the accumulation of machining oil, which could be contaminated with fungal spores. When this is the case, the gaseous sterilization by ethylene oxide may be jeopardized. Cortical screws were also analyzed and were found to present serious metalworking defects inside their heads. To reduce the risk of infection in surgery, the use of screws with metalworking defects on the outer surface, analyzed with stereomicroscope and considering the inside part of the Allen as an outer surface, should be avoided altogether.

  8. Application of Modern Experimental Technique to Solve Morphological Complexity in Plants Taxonomy

    Directory of Open Access Journals (Sweden)

    SURANTO

    2000-07-01

    Full Text Available Modern taxonomy has two approaches, i.e. classical and experimental taxonomy. Classical taxonomy uses morphological characters, while experimental taxonomy uses broader methods including chemistry, physics and mathematics, in the form of laboratory data that are revealed together with the progress of optical technique (microscope, chemistry methods (chromatography, electrophoresis, etc. Modern taxonomy tends to use series of interrelated data. More data used would result in more validity and give better clarification of taxonomic status. A lot of modern taxonomic data such as palynology, cytotaxonomy (cytology, chemical constituent (chemotaxonomy, isozyme and DNA sequencing were used recently.

  9. Combining Lagrangian Decomposition and Excessive Gap Smoothing Technique for Solving Large-Scale Separable Convex Optimization Problems

    CERN Document Server

    Quoc, Tran Dinh; Diehl, Moritz

    2011-01-01

    A new algorithm for solving large-scale separable convex optimization problems is proposed. The basic idea is to combine three techniques including Lagrangian dual decomposition, excessive gap and smoothing techniques. The main advantage of this algorithm is to dynamically update the smoothness parameters which leads to a numerically stable performance ability. The convergence of the algorithm is proved under weak conditions imposed on the original problem. The worst-case complexity is estimated which is $O(1/k)$, where $k$ is the iteration counter. Then, the algorithm is coupled with a dual scheme to construct a switching variant of the dual decomposition. Discussion on the implementation issues is presented and theoretical comparison is analyzed. Numerical results are implemented to confirm the theoretical development.

  10. On large-scale nonlinear programming techniques for solving optimal control problems

    Energy Technology Data Exchange (ETDEWEB)

    Faco, J.L.D.

    1994-12-31

    The formulation of decision problems by Optimal Control Theory allows the consideration of their dynamic structure and parameters estimation. This paper deals with techniques for choosing directions in the iterative solution of discrete-time optimal control problems. A unified formulation incorporates nonlinear performance criteria and dynamic equations, time delays, bounded state and control variables, free planning horizon and variable initial state vector. In general they are characterized by a large number of variables, mostly when arising from discretization of continuous-time optimal control or calculus of variations problems. In a GRG context the staircase structure of the jacobian matrix of the dynamic equations is exploited in the choice of basic and super basic variables and when changes of basis occur along the process. The search directions of the bound constrained nonlinear programming problem in the reduced space of the super basic variables are computed by large-scale NLP techniques. A modified Polak-Ribiere conjugate gradient method and a limited storage quasi-Newton BFGS method are analyzed and modifications to deal with the bounds on the variables are suggested based on projected gradient devices with specific linesearches. Some practical models are presented for electric generation planning and fishery management, and the application of the code GRECO - Gradient REduit pour la Commande Optimale - is discussed.

  11. Video demonstrations seed alternative problem-solving techniques in wild common marmosets.

    Science.gov (United States)

    Gunhold, Tina; Whiten, Andrew; Bugnyar, Thomas

    2014-09-01

    Studies of social learning and tradition formation under field conditions have recently gained momentum, but suffer from the limited control of socio-ecological factors thought to be responsible for transmission patterns. The use of artificial visual stimuli is a potentially powerful tool to overcome some of these problems. Here, in a field experiment, we used video images of unfamiliar conspecifics performing virtual demonstrations of foraging techniques. We tested 12 family groups of wild common marmosets. Six groups received video demonstrations (footage of conspecifics either pulling a drawer open or pushing a lid upwards, in an 'artificial fruit'); the other six groups served as controls (exposed to a static image of a conspecific next to the fruit). Subjects in video groups were more manipulative and successful in opening the fruit than controls; they were also more likely to use the technique they had witnessed and thus could serve as live models for other family members. To our knowledge, this is the first study that used video demonstrations in the wild and demonstrated the potent force of social learning, even from unfamiliar conspecifics, under field conditions.

  12. A New Technique for Solving Tightrope Cutout during Acromioclavicular Joint Fixation: A Case Report

    Directory of Open Access Journals (Sweden)

    Ng BW

    2017-03-01

    Full Text Available Acromioclavicular joint (ACJ dissociation is one of the common injuries affecting adults. The stability of ACJ largely depends on the integrity of acromioclavicular ligament, coracoclavicular ligament, capsule, trapezius muscle and deltoid muscle. The injury has been classified by Rockwood into six types and treatment options can be guided by the classification. TightRope fixation is one of the many surgical procedures available to address acromioclavicular joint separation. It consists of tensioning of a no. 5 Fibrewire suture secured at both ends to low- profile metallic buttons. Despite various advantages of using this technique, complications such as suture cut-out, clavicle fracture and suture failure have been documented. The author presents a case of a type III acromioclavicular joint dissociation treated with TightRope which suture cutout was noted intra-operatively. Decision to amend the fixation using a cut one-third tubular plate as an additional anchor for the metallic button on the clavicle was made. Patient’s progress was evaluated using the University of California at Los Angeles Shoulder Score (UCLA Shoulder Score and significant improvement was noted six months post operatively. We propose this technique as a solution to the encountered problem.

  13. A New Technique for Solving Tightrope Cutout during Acromioclavicular Joint Fixation: A Case Report

    Science.gov (United States)

    Abdullah, AF; Nadarajah, S

    2017-01-01

    Acromioclavicular joint (ACJ) dissociation is one of the common injuries affecting adults. The stability of ACJ largely depends on the integrity of acromioclavicular ligament, coracoclavicular ligament, capsule, trapezius muscle and deltoid muscle. The injury has been classified by Rockwood into six types and treatment options can be guided by the classification. TightRope fixation is one of the many surgical procedures available to address acromioclavicular joint separation. It consists of tensioning of a no. 5 Fibrewire suture secured at both ends to low-profile metallic buttons. Despite various advantages of using this technique, complications such as suture cut-out, clavicle fracture and suture failure have been documented. The author presents a case of a type III acromioclavicular joint dissociation treated with TightRope which suture cutout was noted intra-operatively. Decision to amend the fixation using a cut one-third tubular plate as an additional anchor for the metallic button on the clavicle was made. Patient’s progress was evaluated using the University of California at Los Angeles Shoulder Score (UCLA Shoulder Score) and significant improvement was noted six months post operatively. We propose this technique as a solution to the encountered problem. PMID:28435576

  14. Finite element methods for engineering sciences. Theoretical approach and problem solving techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chaskalovic, J. [Ariel University Center of Samaria (Israel); Pierre and Marie Curie (Paris VI) Univ., 75 (France). Inst. Jean le Rond d' Alembert

    2008-07-01

    This self-tutorial offers a concise yet thorough grounding in the mathematics necessary for successfully applying FEMs to practical problems in science and engineering. The unique approach first summarizes and outlines the finite-element mathematics in general and then, in the second and major part, formulates problem examples that clearly demonstrate the techniques of functional analysis via numerous and diverse exercises. The solutions of the problems are given directly afterwards. Using this approach, the author motivates and encourages the reader to actively acquire the knowledge of finite- element methods instead of passively absorbing the material, as in most standard textbooks. The enlarged English-language edition, based on the original French, also contains a chapter on the approximation steps derived from the description of nature with differential equations and then applied to the specific model to be used. Furthermore, an introduction to tensor calculus using distribution theory offers further insight for readers with different mathematical backgrounds. (orig.)

  15. Automatic approach to solve the morphological galaxy classification problem using the sparse representation technique and dictionary learning

    Science.gov (United States)

    Diaz-Hernandez, R.; Ortiz-Esquivel, A.; Peregrina-Barreto, H.; Altamirano-Robles, L.; Gonzalez-Bernal, J.

    2016-06-01

    The observation of celestial objects in the sky is a practice that helps astronomers to understand the way in which the Universe is structured. However, due to the large number of observed objects with modern telescopes, the analysis of these by hand is a difficult task. An important part in galaxy research is the morphological structure classification based on the Hubble sequence. In this research, we present an approach to solve the morphological galaxy classification problem in an automatic way by using the Sparse Representation technique and dictionary learning with K-SVD. For the tests in this work, we use a database of galaxies extracted from the Principal Galaxy Catalog (PGC) and the APM Equatorial Catalogue of Galaxies obtaining a total of 2403 useful galaxies. In order to represent each galaxy frame, we propose to calculate a set of 20 features such as Hu's invariant moments, galaxy nucleus eccentricity, gabor galaxy ratio and some other features commonly used in galaxy classification. A stage of feature relevance analysis was performed using Relief-f in order to determine which are the best parameters for the classification tests using 2, 3, 4, 5, 6 and 7 galaxy classes making signal vectors of different length values with the most important features. For the classification task, we use a 20-random cross-validation technique to evaluate classification accuracy with all signal sets achieving a score of 82.27 % for 2 galaxy classes and up to 44.27 % for 7 galaxy classes.

  16. The Study Of Metalworking Fluids Biodegradability By Indirect Measurement Of Bacterial Inoculum Respiration

    Directory of Open Access Journals (Sweden)

    Gerulová Kristína

    2015-06-01

    Full Text Available An apparatus for measuring biodegradability of metalworking fluids (MWFs was constructed according to (1, based on the Zahn-Wellens test which enables a continuous determination of CO2 production by the change in conductivity of absorption solution. Results obtained from the testing of 8 different MWFs by this modified method were compared to those obtained in standardized OECD 302 B. The comparison showed better description of bacterial inoculum activity in tested solution; lag phase was easy to indicate. Tested emulsion achieved the level of primary degradability 39.7 – 40.8 %, and semi-synthetics 19.1 – 43.5%. The samples of synthetics where the degradation level reached 43.9 - 58.6 % were identified as the most degradable metalworking fluids.

  17. Advanced Metalworking Solutions For Naval Systems That Go In Harm’s Way

    Science.gov (United States)

    2015-01-01

    AND ADDRESS(ES) NMC Information Services,, Concurrent Technologies Corporation,100 CTC Drive,,Johnstown,,PA, 15904 8. PERFORMING ORGANIZATION REPORT...metalworking and manufacturing processes and to implement the solutions in the U.S. industrial base. NMC is operated by Concurrent Technologies...improvements in machining productivity is expected to save at least $6M over a five-year period. The IPT also investigated improved methods for threading

  18. An efficient formulation of the coupled finite element-integral equation technique for solving large 3D scattering problems

    Science.gov (United States)

    Cwik, T.; Jamnejad, V.; Zuffada, C.

    1993-01-01

    It is often desirable to calculate the electromagnetic fields inside and about a complicated system of scattering bodies, as well as in their far-field region. The finite element method (FE) is well suited to solving the interior problem, but the domain has to be limited to a manageable size. At the truncation of the FE mesh one can either impose approximate (absorbing) boundary conditions or set up an integral equation (IE) for the fields scattered from the bodies. The latter approach is preferable since it results in higher accuracy. Hence, the two techniques can be successfully combined by introducing a surface that encloses the scatterers, applying a FE model to the inner volume and setting up an IE for the tangential fields components on the surface. Here the continuity of the tangential fields is used bo obtain a consistent solution. A few coupled FE-IE methods have recently appeared in the literature. The approach presented here has the advantage of using edge-based finite elements, a type of finite elements with degrees of freedom associated with edges of the mesh. Because of their properties, they are better suited than the conventional node based elements to represent electromagnetic fields, particularly when inhomogeneous regions are modeled, since the node based elements impose an unnatural continuity of all field components across boundaries of mesh elements. Additionally, our approach is well suited to handle large size problems and lends itself to code parallelization. We will discuss the salient features that make our approach very efficient from the standpoint of numerical computation, and the fields and RCS of a few objects are illustrated as examples.

  19. 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)

  20. The Study Into Potential Enhacement Of Metalworking Fluids Biodegradability By The Application Of O3/UV

    Directory of Open Access Journals (Sweden)

    Gerulová Kristína

    2015-06-01

    Full Text Available The increase in mineralization and biodegradability of MWFs by ozone/ultraviolet in comparison with ozone were investigated. Studied were two similar synthetic fluids pre-treated by the combination of the O3/UV advanced oxidative method. Expectations that the pre-treatment could enhance biodegradability of the metalworking fluid were not confirmed. The combined oxidation process at the defined conditions resulted in 1-35 % decrease of the achieved primary degradation level. Samples were prepared from real concentrates and diluted to approximately 350 mg/L of TOC.

  1. Feasibility Study – Using a Solar Evaporator to Reduce the Metalworking Fluid (MWF) Waste Stream

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, Lloyd

    2008-12-03

    A solar evaporator was designed, built, and operated to reduce the water-based metalworking fluid waste stream. The evaporator was setup in Waste Management’s barrel lot inside one of the confinement areas. The unit processed three batches of waste fluid during the prototype testing. Initial tests removed 13% of the fluid waste stream. Subsequent modifications to the collector improved the rate to almost 20% per week. Evaluation of the risk during operation showed that even a small spill when associated with precipitation, and the unit placement within a confinement area, gave it the potential to contaminate more fluid that what it could save.

  2. Ra and the average effective strain of surface asperities deformed in metal-working processes

    DEFF Research Database (Denmark)

    Bay, Niels; Wanheim, Tarras; Petersen, A. S

    1975-01-01

    Based upon a slip-line analysis of the plastic deformation of surface asperities, a theory is developed determining the Ra-value (c.l.a.) and the average effective strain in the surface layer when deforming asperities in metal-working processes. The ratio between Ra and Ra0, the Ra-value after...... and before deformation, is a function of the nominal normal pressure and the initial slope γ0 of the surface asperities. The last parameter does not influence Ra significantly. The average effective strain View the MathML sourcege in the deformed surface layer is a function of the nominal normal pressure...

  3. Community-acquired Pseudomonas aeruginosa-pneumonia in a previously healthy man occupationally exposed to metalworking fluids

    Directory of Open Access Journals (Sweden)

    Fernando Peixoto Ferraz de Campos

    2014-09-01

    Full Text Available Although the Pseudomonas aeruginosa infection is well known and frequently found in hospitals and nursing care facilities, many cases are also reported outside these boundaries. In general, this pathogen infects debilitated patients either by comorbidities or by any form of immunodeficiency. In cases of respiratory infection, tobacco abuse seems to play an important role as a risk factor. In previously healthy patients, community-acquired pneumonia (CAP with P. aeruginosa as the etiological agent is extremely rare, and unlike the cases involving immunocompromised or hospitalized patients, the outcome is severe, and is fatal in up to 61.1% of cases. Aerosolized contaminated water or solutions are closely linked to the development of respiratory tract infection. In this setting, metalworking fluids used in factories may be implicated in CAP involving previously healthy people. The authors report the case of a middle-aged man who worked in a metalworking factory and presented a right upper lobar pneumonia with a rapid fatal outcome. P. aeruginosa was cultured from blood and tracheal aspirates. The autopsy findings confirmed a hemorrhagic necrotizing pneumonia with bacteria-invading vasculitis and thrombosis. A culture of the metalworking fluid of the factory was also positive for P. aeruginosa. The pulsed-field gel electrophoresis showed that both strains (blood culture and metalworking fluid were genetically indistinguishable. The authors highlight the occupational risk for the development of this P. aeruginosa-infection in healthy people.

  4. Adsorption of emulsified oil from metalworking fluid on activated bleaching earth-chitosan-SDS composites: Optimization, kinetics, isotherms.

    Science.gov (United States)

    Naowanat, Nitiya; Thouchprasitchai, Nutthavich; Pongstabodee, Sangobtip

    2016-03-15

    The adsorption of emulsified oil from metalworking fluid (MWF) on activated bleaching earth (BE)-chitosan-sodium dodecyl sulfate (SDS) composites (BE/MCS) was investigated under a statistical design of experiments at a 95% confidence interval to identify the critical factors and to optimize the adsorption capacity. The BE/MCS adsorbents were characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption/desorption isotherms, contact angle analysis (sessile drop technique) and their zeta potential. From the results of a full 2(5) factorial design with three center points, the adsorbent weight and initial pH of the MWF had a significant antagonistic effect on the adsorption capacity while the initial MWF concentration and BE:chitosan:SDS weight ratio had a synergistic influence. Temperature factor has no discernible effect on the capacity. From the FCCC-RSM design, the optimal capacity range of 2840-2922.5 mg g(-1) was achieved at sorbent weight of 1.6-1.9 g, pH of 5.5-6.5, initial MWF concentration of 52-55 g l(-1) and BE:chitosan:SDS (w/w/w) ratio of 4.7:1:1-6.2:1:1. To test the validation and sensitivity of RSM model, the results showed that the estimated adsorption capacity was close to the experimental capacity within an error range of ±3%, suggesting that the RSM model was acceptable and satisfied. From three kinetics models (pseudo-first-order, pseudo-second-order model and Avrami's equation) and two adsorption isotherms (Langmuir model and Freundlich model), assessed using an error function (Err) and the coefficient of determination (R(2)), Avrami's equation and Freundlich isotherm model provided a good fitting for the data, suggesting the presence of more than one reaction pathway in the MWF adsorption process and the heterogeneous surface adsorption of the BC/ABE-5.5 composite.

  5. Ecological and Toxicological Characteristics of Metalworking Fluids Used in Finishing Processing in Russian Federation

    Science.gov (United States)

    Grigoriev, S. N.; Bobrovskij, N. M.; Melnikov, P. A.; Bobrovskij, I. N.; Levitskih, O. O.

    2017-05-01

    Nowadays, metalworking fluids (MWF) in the design of technological processes in most cases are considered as mandatory persistant components despite the constant improvement of the technology of machining, tools and equipment. Three main functions of MWF: cooling, lubrication, waste chips removal - seems to be the essential condition for stable process. In most cases, cooling reduces wear of tool and improves the quality of the processed surface. The cooling characteristics of the MWF affect not only the heat capacity and thermal conductivity, but metal surfaces wettability and vaporization. If processing speed and temperature of the fluid are high then it may not be in direct contact with the surface of the tool due to low wettability or vapor blankets. Improvement of machining process with applying the MWF is accompanied with negative factors. Due to the high temperatures in the treatment area it is exposed to MWF vaporization. This article presents estimation of the applicable in Russian Federation MWF: fire risk, toxicological and environmental hazards.

  6. Tabu Search Technique for Solving the Routing Problem%禁忌搜索算法用于解决网络路由问题

    Institute of Scientific and Technical Information of China (English)

    王东平; 李绍荣

    2003-01-01

    Routing problem is a very import problem in the network design. However, with the increasing of the number of vertices, the convergence speed of the conventional method (such as the Dijkstra algorithm) becomes slow. In some services, the accurate shortest path isn't requested. This paper presents a new algorithm for solving this problem based on the tabu search technique. The tabu search algorithm can get the satisfied path with the changing of the iteration times, the tabu period and neighborhood size. Simulation results demonstrate that the proposed method is very efficient for computing the shorted path, especially when the scale of the network is large.

  7. An improved survivability prognosis of breast cancer by using sampling and feature selection technique to solve imbalanced patient classification data.

    Science.gov (United States)

    Wang, Kung-Jeng; Makond, Bunjira; Wang, Kung-Min

    2013-11-09

    Breast cancer is one of the most critical cancers and is a major cause of cancer death among women. It is essential to know the survivability of the patients in order to ease the decision making process regarding medical treatment and financial preparation. Recently, the breast cancer data sets have been imbalanced (i.e., the number of survival patients outnumbers the number of non-survival patients) whereas the standard classifiers are not applicable for the imbalanced data sets. The methods to improve survivability prognosis of breast cancer need for study. Two well-known five-year prognosis models/classifiers [i.e., logistic regression (LR) and decision tree (DT)] are constructed by combining synthetic minority over-sampling technique (SMOTE), cost-sensitive classifier technique (CSC), under-sampling, bagging, and boosting. The feature selection method is used to select relevant variables, while the pruning technique is applied to obtain low information-burden models. These methods are applied on data obtained from the Surveillance, Epidemiology, and End Results database. The improvements of survivability prognosis of breast cancer are investigated based on the experimental results. Experimental results confirm that the DT and LR models combined with SMOTE, CSC, and under-sampling generate higher predictive performance consecutively than the original ones. Most of the time, DT and LR models combined with SMOTE and CSC use less informative burden/features when a feature selection method and a pruning technique are applied. LR is found to have better statistical power than DT in predicting five-year survivability. CSC is superior to SMOTE, under-sampling, bagging, and boosting to improve the prognostic performance of DT and LR.

  8. The employee satisfaction in metalworking manufacturing: How do organizational culture and organizational learning capacity jointly affect it?

    Directory of Open Access Journals (Sweden)

    Bulent Aydin

    2008-12-01

    Full Text Available It is a known fact that the organizations, which give more attention to the satisfaction of their employees, produce more successful outcomes than others do. In this sense, we have constructed an original model and carried out a research analysis in metalworking manufacturing, which the main subject is about to investigate the employee satisfaction depending on the factors of organizational culture and organizational learning capacity. The aim of the research is to contribute to academic researchers as well as managerial level and human resource department employees of metalworking organizations, in maximizing the employee satisfaction. The research was applied on 578 employees of the related industry. By the results, we have determined that the constructed model is significant and there is positive significant correlation both between -organizational culture and employee satisfaction- and -organizational learning capacity and employee satisfaction. Additionally, the total explained variance of employee satisfaction depending on these two variables has come out as the value of 0.56.

  9. A finite difference technique for solving a time strain separable K-BKZ constitutive equation for two-dimensional moving free surface flows

    Science.gov (United States)

    Tomé, M. F.; Bertoco, J.; Oishi, C. M.; Araujo, M. S. B.; Cruz, D.; Pinho, F. T.; Vynnycky, M.

    2016-04-01

    This work is concerned with the numerical solution of the K-BKZ integral constitutive equation for two-dimensional time-dependent free surface flows. The numerical method proposed herein is a finite difference technique for simulating flows possessing moving surfaces that can interact with solid walls. The main characteristics of the methodology employed are: the momentum and mass conservation equations are solved by an implicit method; the pressure boundary condition on the free surface is implicitly coupled with the Poisson equation for obtaining the pressure field from mass conservation; a novel scheme for defining the past times t‧ is employed; the Finger tensor is calculated by the deformation fields method and is advanced in time by a second-order Runge-Kutta method. This new technique is verified by solving shear and uniaxial elongational flows. Furthermore, an analytic solution for fully developed channel flow is obtained that is employed in the verification and assessment of convergence with mesh refinement of the numerical solution. For free surface flows, the assessment of convergence with mesh refinement relies on a jet impinging on a rigid surface and a comparison of the simulation of a extrudate swell problem studied by Mitsoulis (2010) [44] was performed. Finally, the new code is used to investigate in detail the jet buckling phenomenon of K-BKZ fluids.

  10. Solving geological and historical puzzles with advanced gemologic techniques: The Franco Dávila (1772 precious opal case

    Directory of Open Access Journals (Sweden)

    J. García-Guinea

    2016-11-01

    Full Text Available The large precious opal weighting 33 grams fitted in a silver jewel and exposed to visitors at the Museo Nacional de Ciencias Naturales (MNCN is well documented in: (i its own mounting (1772, (ii at the 775 document of the Archive of the MNCN and (iii the 395 specimen described in the of Pedro Franco Dávila catalogue. The X-ray diffractogram (XRD performed onto the opal block is very similar to other opals of volcanic origin containing varied amounts of cristobalite, tridymite and amorphous silica. The Raman spectrum shows a band peaked at 242, 343 and 416 cm-1 associated with O-Si-O stretching groups; other spectral band peaked at 780 and 819 cm-1 corresponding to vibration of symmetrical O-Si-O rings of 3 and 4 link members, plus other minor bands. The Raman spectrum is also very similar to those observed in Mexican opals of volcanic origin containing an spectral band of stretching nodes v1 (OH at 3233, 3393, 3511, 3628 cm-1 related to OH groups with hydrogen bonds of isolated silanol groups. The interferometric confocal dual microscope 3D (MCI3D, which is a nondestructive facility of high resolution and LED technology reveals the geometry of graver tools on the silver jewel and the computed tomography X-ray highlights the opal cutting as a squared princess type and silver chloride infillings of a crack probably caused by a shock on a corner. Under the scanning electron microscope we observed barite, sealed veins of silica rich in Mn and opal with high contents of Al and K which, along with the historical data, the piece can be attributed to the historical site of opals hosted in Slovakia andesite rocks, this data explains the optical light behavior in the cabochon. The silver jewel has large amounts of Hg and AgCl indicating amalgam method. In addition the natural AgS2 phases probably come from Nueva España (year 1772 in full production of silver in such time. The association of new analytical non-destructive techniques combines the

  11. Solving geological and historical puzzles with advanced gemologic techniques: The Franco Dávila (1772) precious opal case

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Guinea, J.; Gonzalez-Alcalde, J.; Furio, M.; Jorge, A.; Garrido, F.

    2016-07-01

    The large precious opal weighting 33 grams fitted in a silver jewel and exposed to visitors at the Museo Nacional de Ciencias Naturales (MNCN) is well documented in: (i) its own mounting (1772), (ii) at the 775 document of the Archive of the MNCN and (iii) the 395 specimen described in the of Pedro Franco Dávila catalogue. The X-ray diffractogram (XRD) performed onto the opal block is very similar to other opals of volcanic origin containing varied amounts of cristobalite, tridymite and amorphous silica. The Raman spectrum shows a band peaked at 242, 343 and 416 cm−1 associated with O-Si-O stretching groups; other spectral band peaked at 780 and 819 cm−1 corresponding to vibration of symmetrical O-Si-O rings of 3 and 4 link members, plus other minor bands. The Raman spectrum is also very similar to those observed in Mexican opals of volcanic origin containing an spectral band of stretching nodes ν1 (OH) at 3233, 3393, 3511, 3628 cm−1 related to OH groups with hydrogen bonds of isolated silanol groups. The interferometric confocal dual microscope 3D (MCI3D), which is a nondestructive facility of high resolution and LED technology reveals the geometry of graver tools on the silver jewel and the computed tomography X-ray highlights the opal cutting as a squared princess type and silver chloride infillings of a crack probably caused by a shock on a corner. Under the scanning electron microscope we observed barite, sealed veins of silica rich in Mn and opal with high contents of Al and K which, along with the historical data, the piece can be attributed to the historical site of opals hosted in Slovakia andesite rocks, this data explains the optical light behavior in the cabochon. The silver jewel has large amounts of Hg and AgCl indicating amalgam method. In addition the natural AgS2 phases probably come from Nueva España (year 1772) in full production of silver in such time. The association of new analytical non-destructive techniques combines the

  12. Patch test results with the metalworking fluid series of the German Contact Dermatitis Research Group (DKG).

    Science.gov (United States)

    Geier, Johannes; Lessmann, Holger; Dickel, Heinrich; Frosch, Peter J; Koch, Patrick; Becker, Detlef; Jappe, Uta; Aberer, Werner; Schnuch, Axel; Uter, Wolfgang

    2004-09-01

    Based on the information of the interdisciplinary task force on allergy diagnostics in the metal branch, in 2001, the German Contact Dermatitis Research Group (DKG) compiled two metalworking fluid (MWF) test series with currently and previously used components, respectively. After 2 years of patch testing, we present results obtained with these series, based on data of the Information Network of Departments of Dermatology (IVDK). 251 metalworkers who were patch tested because of suspected MWF dermatitis in 2002 and 2003 were included in this retrospective data analysis. Of these, 206 were tested with the current MWF series and 155 with the historical MWF series. Among the current MWF allergens, monoethanolamine ranked 1st with 11.6% positive reactions. Diethanolamine (3.0%), triethanolamine (1.1%), and diglycolamine (1.9%) elicited positive reactions far less frequently. Allergic reactions to p-aminoazobenzene were frequently observed (6.0%), but the relevance of these reactions is still obscure. Positive reactions to biocides ranged from 4.5% for Bioban CS 1135 to 0.5% for iodopropynyl butylcarbamate and 2-phenoxyethanol. Concomitant reactions to formaldehyde, which caused positive reactions in 3.3%, and formaldehyde releasers occurred to varying extents without conclusive pattern. No positive reactions were seen to dibutyl phthalate, di-2-ethylhexyl phthalate, tricresyl phosphate, isopropyl myristate or benzotriazole. With the historical MWF test series, positive reactions to methyldibromo glutaronitrile (MDBGN) were observed most frequently. However, sensitization via allergen sources other than MWF seems likely, as MDBGN, during the study period, has been one of the most frequent preservative allergens in cosmetics and body care products. Other historical MWF allergens comprised morpholinyl mercaptobenzothiazole (3.3%), benzisothiazolinone (BIT; 2.0%) and Bioban P 1487(1.3%). BIT is currently used in MWF again, so it was shifted to the current MWF test series

  13. Research of Tool Durability in Surface Plastic Deformation Processing by Burnishing of Steel Without Metalworking Fluids

    Science.gov (United States)

    Grigoriev, S. N.; Bobrovskij, N. M.; Melnikov, P. A.; Bobrovskij, I. N.

    2017-05-01

    Modern vector of development of machining technologies aimed at the transition to environmentally safe technologies - “green” technologies. The concept of “green technology” includes a set of signs of knowledge intended for practical use (“technology”). One of the ways to improve the quality of production is the use of surface plastic deformation (SPD) processing methods. The advantage of the SPD is a capability to combine effects of finishing and strengthening treatment. The SPD processing can replace operations: fine turning, grinding or polishing. The SPD is a forceful contact impact of indentor on workpiece’s surface in condition of their relative motion. It is difficult to implement the core technology of the SPD (burnishing, roller burnishing, etc.) while maintaining core technological advantages without the use of lubricating and cooling technology (metalworking fluids, MWF). The “green” SPD technology was developed by the authors for dry processing and has not such shortcomings. When processing with SPD without use of MWF requirements for tool’s durability is most significant, especially in the conditions of mass production. It is important to determine the period of durability of tool at the design stage of the technological process with the purpose of wastage preventing. This paper represents the results of durability research of natural and synthetic diamonds (polycrystalline diamond - ASPK) as well as precision of polycrystalline superabrasive tools made of dense boron nitride (DBN) during SPD processing without application of MWF.

  14. Integral methodology simulation support for the improvement of production systems job shop. Metalworking applications in SMES

    Directory of Open Access Journals (Sweden)

    Jaime Alberto Giraldo García

    2010-05-01

    Full Text Available Metalworking companies represent one of the strategic sectors in the regional economy of the Caldas department in Colombia; in fact, this sector is involved in 31% of the department’s industrial establishments and 29% of industrial employment according to DANE (Colombian State Statistical Department statistical data from 2005. The sector also exports to Andean countries. However, preliminary studies conducted with 57% of the entrepreneurs from this sector (excluding micro companies and family businesses have revealed serious structural (technology, processing, installations and infrastructure weaknesses (production planning, quality systems in these organisations’ production systems. It is hoped that this paper will lead to disseminating the results amongst the academic community of implementing a comprehensive methodology for improving the production system of a pilot company from this particular sector. An experimental framework for improving the levels reached by the system regarding such priorities is proposed following universally accepted methodology in discrete simulation studies; it proposes using sequential bifurcation, factorial design and response surface experimentation based on defining and weighting the competing priorities which the company should achieve. The improvements in the pilot company’s production system priorities are presented in terms of an effectiveness index (EI which rose from 1.84 to 2.46 by the end of the study.

  15. Distribution of Fatty Acids and Triethanolamine in Synthetic Metalworking Fluid Aerosols Generated in the Laboratory and Field

    Energy Technology Data Exchange (ETDEWEB)

    Ilgner, R.H., Palausky, A., Jenkins, R.A. [Oak Ridge National Lab., TN (United States) Chemical and Analytical Sciences Div.], Ball, A.M., Lucke, W.E. [Cincinnati Milacron, OH (United States)

    1997-12-31

    Metalworking fluid mists were generated in the laboratory with selected synthetic fluids by nebulization and with an air sparging apparatus. Short chain fatty acid species were determined in the vapor and particulate phase of the resulting aerosols using in-situ trimethyl silyl derivatization. Certain fatty acid species in sparger generated mists were found in the vapor phase in greater quantities relative to the particle phase, compared with the corresponding amounts determined in nebulized mists. With one metalworking fluid, the nonanoic acid vapor phase to particulate phase concentration ratio was over 14 fold higher with air sparged mists (1.0) than with the corresponding nebulized mists (0.07). The nonanoic acid vapor phase concentrations were 0.026 mg/m{sup 3} and 0.002 mg/m{sup 3} for sparged (bubbled) and nebulized mists respectively. This phenomenon was observed with mists generated from several selected synthetic metalworking fluids. This could suggest that in the work place environment, with a variety of mist generation mechanisms occurring simultaneously, significant vapor phase concentrations of certain species could exist in an environment where particulate levels are low. Vapor phase fatty acid levels could remain relatively high in an occupational setting even when mist levels are reduced with efficient air cleaning devices. Results from mist generation experiments performed in the laboratory, were compared with actual field data from a relatively clean metal machining operation. Anecdotal evidence of potential irritation by short chain fatty acids prompted a study of this industrial site. Numerous air scrubbing devices were utilized at this industrial site to reduce airborne particulates, which typically ranged from 0.05 to 0.4 mg/m{sup 3}. Comparisons were made of triethanolamine and short chain fatty acid concentrations in vapor and particulate phases measured in the laboratory and work place environment.

  16. Adaptive Problem Solving

    Science.gov (United States)

    2017-03-01

    the "SAS+-level Changes" section. Many modern heuristics use a technique called "delete- relaxation ". Delete relaxation does not handle counts and...use the same algorithm, representation, and use the same technique to generate their heuristics. The drawback of this is that there is almost never...one problem solving technique , one representation, or one way to create heuristics that works well on all problems/domains. There is a tradeoff

  17. Dermal permeation of biocides and aromatic chemicals in three generic formulations of metalworking fluids.

    Science.gov (United States)

    Vijay, Vikrant; White, Eugene M; Kaminski, Michael D; Riviere, Jim E; Baynes, Ronald E

    2009-01-01

    Metalworking fluids (MWF) are complex mixtures consisting of a variety of components and additives. A lack of scientific data exists regarding the dermal permeation of its components, particularly biocides. The aim of this study was to evaluate the dermal permeation of biocides and other aromatic chemicals in water and in three generic soluble oil, semi-synthetic, and synthetic MWF types in order to evaluate any differences in their permeation profiles. An in vitro flow-through diffusion cell study was performed to determine dermal permeation. An infinite dose of different groups of chemicals (6 biocides and 29 aromatic chemicals) was applied to porcine skin, with perfusate samples being collected over an 8-h period. Perfusate samples were analyzed by gas chromatography/mass spectrometry (GC-MS) and ultra-performance liquid chromatography/mass spectroscopy (UPLC-MS), and permeability was calculated from the analysis of the permeated chemical concentration-time profile. In general, the permeation of chemicals was highest in aqueous solution, followed by synthetic, semi-synthetic, and soluble oil MWF. The absorption profiles of most of the chemicals including six biocides were statistically different among the synthetic and soluble oil MWF formulations, with reduced permeation occurring in oily formulations. Permeation of almost all chemicals was statistically different between aqueous and three MWF formulation types. Data from this study show that permeation of chemicals is higher in a generic synthetic MWF when compared to a soluble oil MWF. This indicates that a soluble oil MWF may be safer than a synthetic MWF in regard to dermal permeation of chemicals to allow for an increased potential of systemic toxicity. Therefore, one may conclude that a synthetic type of formulation has more potential to produce contact dermatitis and induce systemic toxicological effects. The dilution of these MWF formulations with water may increase dermal permeability of biocides

  18. Airway symptoms and biological markers in nasal lavage fluid in subjects exposed to metalworking fluids.

    Directory of Open Access Journals (Sweden)

    Louise Fornander

    Full Text Available BACKGROUNDS: Occurrence of airway irritation among industrial metal workers was investigated. The aims were to study the association between exposures from water-based metal working fluids (MWF and the health outcome among the personnel, to assess potential effects on the proteome in nasal mucous membranes, and evaluate preventive actions. METHODS: The prevalence of airway symptoms related to work were examined among 271 metalworkers exposed to MWF and 24 metal workers not exposed to MWF at the same factory. At the same time, air levels of potentially harmful substances (oil mist, morpholine, monoethanolamine, formaldehyde generated from MWF was measured. Nasal lavage fluid was collected from 13 workers and 15 controls and protein profiles were determined by a proteomic approach. RESULTS: Airway symptoms were reported in 39% of the workers exposed to MWF although the measured levels of MWF substances in the work place air were low. Highest prevalence was found among workers handling the MWF machines but also those working in the same hall were affected. Improvement of the ventilation to reduce MWF exposure lowered the prevalence of airway problems. Protein profiling showed significantly higher levels of S100-A9 and lower levels of SPLUNC1, cystatin SN, Ig J and β2-microglobulin among workers with airway symptoms. CONCLUSIONS: This study confirms that upper airway symptoms among metal workers are a common problem and despite low levels of MWF-generated substances, effects on airway immune proteins are found. Further studies to clarify the role of specific MWF components in connection to airway inflammation and the identified biological markers are warranted.

  19. Factors influencing the microbial composition of metalworking fluids and potential implications for machine operator's lung.

    Science.gov (United States)

    Murat, Jean-Benjamin; Grenouillet, Frédéric; Reboux, Gabriel; Penven, Emmanuelle; Batchili, Adam; Dalphin, Jean-Charles; Thaon, Isabelle; Millon, Laurence

    2012-01-01

    Hypersensitivity pneumonitis, also known as "machine operator's lung" (MOL), has been related to microorganisms growing in metalworking fluids (MWFs), especially Mycobacterium immunogenum. We aimed to (i) describe the microbiological contamination of MWFs and (ii) look for chemical, physical, and environmental parameters associated with variations in microbiological profiles. We microbiologically analyzed 180 MWF samples from nonautomotive plants (e.g., screw-machining or metal-cutting plants) in the Franche-Comté region in eastern France and 165 samples from three French automotive plants in which cases of MOL had been proven. Our results revealed two types of microbial biomes: the first was from the nonautomotive industry, showed predominantly Gram-negative rods (GNR), and was associated with a low risk of MOL, and the second came from the automotive industry that was affected by cases of MOL and showed predominantly Gram-positive rods (GPR). Traces of M. immunogenum were sporadically detected in the first type, while it was highly prevalent in the automotive sector, with up to 38% of samples testing positive. The use of chromium, nickel, or iron was associated with growth of Gram-negative rods; conversely, growth of Gram-positive rods was associated with the absence of these metals. Synthetic MWFs were more frequently sterile than emulsions. Vegetable oil-based emulsions were associated with GNR, while mineral ones were associated with GPR. Our results suggest that metal types and the nature of MWF play a part in MWF contamination, and this work shall be followed by further in vitro simulation experiments on the kinetics of microbial populations, focusing on the phenomena of inhibition and synergy.

  20. Comparative pulmonary toxicity of inhaled metalworking fluids in rats and mice.

    Science.gov (United States)

    Ryan, Kristen R; Cesta, Mark F; Herbert, Ronald; Brix, Amy; Cora, Michelle; Witt, Kristine; Kissling, Grace; Morgan, Daniel L

    2017-05-01

    Metalworking fluids (MWFs) are complex formulations designed for effective lubricating, cooling, and cleaning tools and parts during machining operations. Adverse health effects such as respiratory symptoms, dermatitis, and cancer have been reported in workers exposed to MWFs. Several constituents of MWFs have been implicated in toxicity and have been removed from the formulations over the years. However, animal studies with newer MWFs demonstrate that they continue to pose a health risk. This investigation examines the hypothesis that unrecognized health hazards exist in currently marketed MWF formulations that are presumed to be safe based on hazard assessments of individual ingredients. In vivo 13-week inhalation studies were designed to characterize and compare the potential toxicity of four MWFs: Trim VX, Cimstar 3800, Trim SC210, and Syntilo 1023. Male and female Wistar Han rats or Fischer 344N/Tac rats and B6C3F1/N mice were exposed to MWFs via whole-body inhalation at concentrations of 0, 25, 50, 100, 200, or 400 mg/m(3) for 13 weeks, after which, survival, body and organ weights, hematology and clinical chemistry, histopathology, and genotoxicity were assessed following exposure. Although high concentrations were used, survival was not affected and toxicity was primarily within the respiratory tract of male and female rats and mice. Minor variances in toxicity were attributed to differences among species as well as in the chemical components of each MWF. Pulmonary fibrosis was present only in rats and mice exposed to Trim VX. These data confirm that newer MWFs have the potential to cause respiratory toxicity in workers who are repeatedly exposed via inhalation.

  1. Lemna minor tolerance to metal-working fluid residues: implications for rhizoremediation.

    Science.gov (United States)

    Grijalbo, L; Becerril, J M; Barrutia, O; Gutierrez-Mañero, J; Lucas Garcia, J A

    2016-07-01

    For the first time in the literature, duckweed (Lemna minor) tolerance (alone or in combination with a consortium of bacteria) to spent metal-working fluid (MWF) was assessed, together with its capacity to reduce the chemical oxygen demand (COD) of this residue. In a preliminary study, L. minor response to pre-treated MWF residue (ptMWF) and vacuum-distilled MWF water (MWFw) was tested. Plants were able to grow in both residues at different COD levels tested (up to 2300 mg·l(-1) ), showing few toxicity symptoms (mainly growth inhibition). Plant response to MWFw was more regular and dose responsive than when exposed to ptMWF. Moreover, COD reduction was less significant in ptMWF. Thus, based on these preliminary results, a second study was conducted using MWFw to test the effectiveness of inoculation with a bacterial consortium isolated from a membrane bioreactor fed with the same residue. After 5 days of exposure, COD in solutions containing inoculated plants was significantly lower than in non-inoculated ones. Moreover, inoculation reduced β+γ-tocopherol levels in MWFw-exposed plants, suggesting pollutant imposed stress was reduced. We therefore conclude from that L. minor is highly tolerant to spent MWF residues and that this species can be very useful, together with the appropriate bacterial consortium, in reducing COD of this residue under local legislation limits and thus minimise its potential environmental impact. Interestingly, the lipophilic antioxidant tocopherol (especially the sum of β+γ isomers) proved to be an effective plant biomarker of pollution.

  2. Evaluation of 2 self-administered questionnaires to ascertain dermatitis among metal workers and its relation with exposure to metalworking fluids

    NARCIS (Netherlands)

    Wendel de Joode, B. van; Vermeulen, R.; Heederik, D.; Ginkel, K. van; Kromhout, H.

    2007-01-01

    We performed an exploratory study to evaluate 2 self-administered questionnaires assessing hand dermatitis and investigate a possible exposure-response relationship between dermal exposure to semi-synthetic metalworking fluids (SMWF) and dermatitis. In a cross-sectional survey on dermatitis, a sympt

  3. Evaluating workers' exposure to metalworking fluids and effective factors in their dispersion in a car manufacturing factory.

    Science.gov (United States)

    Andani, Abbasali Mokhtari; Golbabaei, Farideh; Shahtaheri, Seyed Jamaladdin; Foroushani, Abbas Rahimi

    2014-01-01

    Metalworking fluids (MWFs), which are widely used in metal working operations, can cause different adverse effects, e.g., dermal and respiratory disorders, and cancer. Evaluating workers' exposure to MWF mists and the effective factors in their dispersion were the purpose of this study. Seventy-five out of 300 workers working in metalworking workshops were randomly selected. MWF concentrations were measured with the National Institute for Occupational Safety and Health (NIOSH) 5524 method. Air temperature and velocity were also determined as the predicted effective parameters on the level of exposure. The results indicated that exposure to MWF mists in one workshop was higher than in the other ones (p < .05). The findings also showed that temperature was an effective factor in the dispersion of MWF mists (p < .05). The exposure of almost all workers was under the threshold limit value of 5 mg/m(3), but it was over the value recommended by NIOSH of 0.5 mg/m(3). Air temperature was an effective factor in workers' exposure (r = .576).

  4. 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.

  5. An investigation on solving cooperative problem solving

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadat Abtahi

    2014-03-01

    Full Text Available One of the most important techniques to improve teaching skills is to use cooperative problem solving (CPS approach. Implementing CPS techniques in elementary schools helps us train more creative generations. This paper presents an empirical investigation to find out how much elementary teachers use CPS techniques at different schools located in city of Zanjan, Iran. The study designs a questionnaire and distributes it among 90 volunteers out of 120 teachers who were enrolled in elementary schools. The study analyzes the data using some basic statistics and the result indicates that teachers maintain an average CPS score of 39.37, which is well above the average level. The study provides some guidelines for exploring teachers CPS’s capabilities.

  6. Evaluation of POE and instructor-led problem-solving approaches integrated into force and motion lecture classes using a model analysis technique

    Science.gov (United States)

    Rakkapao, S.; Pengpan, T.; Srikeaw, S.; Prasitpong, S.

    2014-01-01

    This study aims to investigate the use of the predict-observe-explain (POE) approach integrated into large lecture classes on forces and motion. It is compared to the instructor-led problem-solving method using model analysis. The samples are science (SC, N = 420) and engineering (EN, N = 434) freshmen, from Prince of Songkla University, Thailand. Research findings from the force and motion conceptual evaluation indicate that the multimedia-supported POE method promotes students’ learning better than the problem-solving method, in particular for the velocity and acceleration concepts. There is a small shift of the students’ model states after the problem-solving instruction. Moreover, by using model analysis instructors are able to investigate students’ misconceptions and evaluate teaching methods. It benefits instructors in organizing subsequent instructional materials.

  7. Employees Training Evaluation related to the Competency Standards in the Steel and Metalworking Industry in Boyacá, Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Guillermo Carreno-Bodensiek

    2016-12-01

    Full Text Available This work presents the results of a research process applied to a sample of companies in the steel and metalworking sector in Boyacá, Colombia. The active workers are evaluated over the Occupational Competency Standards related to their daily activities. It also aims to highlight the formation priority of human talent for business, according to build up a level of competitiveness. Also, seeks to meet the need to train and develop skills and competencies in the workforce, taking into account the concepts of experts about training and developing proposals for management. This research is consistent with global trends in education and the requirements of standardization of training, why diagnoses and designs are focused on the functions of the companies related to the Standards of Competency.

  8. Mortality studies of metalworking fluid exposure in the automobile industry: VI. A case-control study of esophageal cancer.

    Science.gov (United States)

    Sullivan, P A; Eisen, E A; Woskie, S R; Kriebel, D; Wegman, D H; Hallock, M F; Hammond, S K; Tolbert, P E; Smith, T J; Monson, R R

    1998-07-01

    Results are reported from a nested case-control study of 60 esophageal cancer deaths among 46,384 automobile manufacturing workers potentially exposed to metalworking fluids (MWF) in machining and grinding operations. By using incidence-density sampling, controls were selected with a sampling ratio of 20:1 from among co-workers who remained at risk by the age of death of the case, matched on race, gender, plant, and year of birth. Conditional logistic regression was used to evaluate the risk associated with cumulative exposure (mg/m3-years) to each of three types of metalworking fluid (straight, soluble, and synthetic MWF), as well as with years of exposure to selected components of MWF, including nitrosamines, sulfur, biocides, and several metals. Esophageal cancer was found to be significantly associated with exposure to both soluble and synthetic MWF in grinding operations. The odds ratios (ORs) for grinding with soluble MWF were elevated at 2.5 or greater in all categories of cumulative exposure, although the exposure-response trend was statistically significant only when exposure was measured as duration. Those with 12 or more years exposure to soluble MWF in grinding operations experienced a 9.3-fold relative risk of esophageal cancer mortality (95% CI = 2.1-42.1). The OR for ever grinding with synthetic MWF was 4.1 (95% CI = 1.1-15.0). Elevated risk was also associated with two agents found in both synthetic and soluble fluids, nitrosamines, and biocides. For exposure to nitrosamines, the OR was 5.4 (95% CI = 1.5-19.9); for biocides the OR was 3.8 (95% CI = 0.8-18.9). However, because the same workers were exposed to grinding with synthetics, nitrosamines and biocides, it was not possible to separate the specific risks associated with these components.

  9. Determinants of exposure to metalworking fluid aerosols: a literature review and analysis of reported measurements.

    Science.gov (United States)

    Park, Donguk; Stewart, Patrica A; Coble, Joseph B

    2009-04-01

    An extensive literature review of published metalworking fluid (MWF) aerosol measurement data was conducted to identify the major determinants that may affect exposure to aerosol fractions (total or inhalable, thoracic and respirable) and mass median diameters (MMDs). The identification of determinants was conducted through published studies and analysis of published measurement levels. For the latter, weighted arithmetic means (WAMs) by number of measurements were calculated and compared using analysis of variance and t-tests. The literature review found that the major factors affecting aerosol exposure levels were, primarily, decade, type of industry, operation and fluid and engineering control measures. Our analysis of total aerosol levels found a significant decline in measured levels from an average of 5.36 mg m(-3) prior to the 1970s and 2.52 mg m(-3) in the 1970s to 1.21 mg m(-3) in the 1980s, 0.50 mg m(-3) in the 1990s and 0.55 mg m(-3) in the 2000s. Significant declines from the 1990s to the 2000s also were found in thoracic fraction levels (0.48 versus 0.40 mg m(-3)), but not for the respirable fraction. The WAMs for the auto (1.47 mg m(-3)) and auto parts manufacturing industry (1.83 mg m(-3)) were significantly higher than that for small-job machine shops (0.68 mg m(-3)). In addition, a significant difference in the thoracic WAM was found between the automotive industry (0.46 mg m(-3)) and small-job machine shops (0.32 mg m(-3)). Operation type, in particular, grinding, was a significant factor affecting the total aerosol fraction [grinding operations (1.75 mg m(-3)) versus other machining (0.95 mg m(-3))], but the levels associated with these operations were not statistically different for either the thoracic or the respirable fractions. Across all decades, the total aerosol fraction for straight oils (1.49 mg m(-3)) was higher than for other fluid types (soluble = 1.08 mg m(-3), synthetic = 0.52 mg m(-3) and semisynthetic = 0.50 mg m(-3)). Fluid type

  10. 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.

  11. A numerical scheme based on radial basis function finite difference (RBF-FD) technique for solving the high-dimensional nonlinear Schrödinger equations using an explicit time discretization: Runge-Kutta method

    Science.gov (United States)

    Dehghan, Mehdi; Mohammadi, Vahid

    2017-08-01

    In this research, we investigate the numerical solution of nonlinear Schrödinger equations in two and three dimensions. The numerical meshless method which will be used here is RBF-FD technique. The main advantage of this method is the approximation of the required derivatives based on finite difference technique at each local-support domain as Ωi. At each Ωi, we require to solve a small linear system of algebraic equations with a conditionally positive definite matrix of order 1 (interpolation matrix). This scheme is efficient and its computational cost is same as the moving least squares (MLS) approximation. A challengeable issue is choosing suitable shape parameter for interpolation matrix in this way. In order to overcome this matter, an algorithm which was established by Sarra (2012), will be applied. This algorithm computes the condition number of the local interpolation matrix using the singular value decomposition (SVD) for obtaining the smallest and largest singular values of that matrix. Moreover, an explicit method based on Runge-Kutta formula of fourth-order accuracy will be applied for approximating the time variable. It also decreases the computational costs at each time step since we will not solve a nonlinear system. On the other hand, to compare RBF-FD method with another meshless technique, the moving kriging least squares (MKLS) approximation is considered for the studied model. Our results demonstrate the ability of the present approach for solving the applicable model which is investigated in the current research work.

  12. Advanced Metalworking Solutions for Naval Systems That Go in Harm’s Way.

    Science.gov (United States)

    2011-01-01

    LCS. You will also read about NMC’s successes in creating prototype tools for various applications, including a brazing system that will solve a...components produced from K-Monel® (Ni- Cu - Al) forgings. The components do not function as needed in a corrosive seawater environment and must be...flame brazing system that will solve a variety of issues associated with the current method used at NNS. The shipyard currently uses a hand-held torch

  13. Creative Problem Solving for Social Studies.

    Science.gov (United States)

    Weiss, Steve; Kinney, Mark; And Others

    1980-01-01

    This article discusses techniques for integrating real problem solving and decision making into secondary social studies programs. Approaches to creative problem solving are presented, and various systematic decision making programs currently available for classroom use are identified. (Author/RM)

  14. Evaluating the use of zinc oxide and titanium dioxide nanoparticles in a metalworking fluid from a toxicological perspective

    Energy Technology Data Exchange (ETDEWEB)

    Seyedmahmoudi, S. H. [Oregon State University, Industrial Sustainability Laboratory, School of Mechanical, Industrial, and Manufacturing Engineering (United States); Harper, Stacey L. [Oregon State University, Department of Environmental and Molecular Toxicology & School of Chemical, Biological and Environmental Engineering (United States); Weismiller, Michael C. [Master Chemical Corporation (United States); Haapala, Karl R., E-mail: karl.haapala@oregonstate.edu [Oregon State University, Industrial Sustainability Laboratory, School of Mechanical, Industrial, and Manufacturing Engineering (United States)

    2015-02-15

    Adding nanoparticles (NPs) to metalworking fluids (MWFs) has been shown to improve performance in metal cutting. Zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO{sub 2} NPs), for example, have exhibited the ability to improve lubricant performance, decrease the heat created by machining operations, reduce friction and wear, and enhance thermal conductivity. ZnO and TiO{sub 2} NPs are also relatively inexpensive compared to many other NPs. Precautionary concerns of human health risks and environmental impacts, however, are especially important when adding NPs to MWFs. The goal of this research is to investigate the potential environmental and human health effects of these nanoenabled products during early design and development. This research builds on a prior investigation of the stability and toxicity characteristics of NPs used in metalworking nanofluids (MWnF™). The previous study only investigated one type of NP at one level of concentration. This research expands on the previous investigations through the valuation of three different types of NPs that vary in morphology (size and shape) and was conducted over a wide range of concentrations in the base fluid. In the presented work, mixtures of a microemulsion (TRIM{sup ®} MicroSol{sup ®} 585XT), two different types of TiO{sub 2} NPs (referred to as TiO{sub 2}A and TiO{sub 2}B) and one type of ZnO NP were used to evaluate MWnF™ stability and toxicity. Dynamic light scattering was used to assess stability over time and an embryonic zebrafish assay was used to assess toxicological impacts. The results reveal that, in general, the addition of these NPs increased toxicity relative to the NP-free formulation. The lowest rate of zebrafish malformations occurred at 5 g/L TiO{sub 2}A NP, which was even lower than for the base fluid. This result is particularly promising for future MWnF™ development, given that the mortality rate for 5 g/L TiO{sub 2}A was not significantly different

  15. Assessment of the toxicity of wastewater from the metalworking industry treated using a conventional physico-chemical process.

    Science.gov (United States)

    Machado, Rodrigo Matuella; Monteggia, Luiz Olinto; Arenzon, Alexandre; Curia, Ana Cristina

    2016-06-01

    This article presents results from a toxicity reduction evaluation program intended to describe wastewater from the metalworking industry that was treated using a conventional physico-chemical process. The toxicity of the wastewater for the microcrustacean Daphnia magna was predominantly expressive. Alkaline cyanide wastewater generated from electroplating accounted for the largest number of samples with expressive toxicity. When the raw wastewater concentrations in the batches were repeated, inexpressive toxicity variations were observed more frequently among the coagulated-flocculated samples. At the coagulation-flocculation step, 22.2 % of the treatments had reduced acute toxicity, 30.6 % showed increased toxicity, and 47.2 % remained unchanged. The conductivity and total dissolved solids contents of the wastewater indicated the presence of salts with charges that were inappropriate for the survival of daphnid. The wastewaters treated by neutralization and coagulation-flocculation had average metallic compound contents that were greater than the reference toxic concentrations reported in other studies, suggesting that metals likely contributed to the toxic effects of the wastewater on freshwater microcrustaceans. Thus, alternative coagulants and flocculants should be assessed, and feasible doses should be determined to improve wastewater treatment. In addition, advanced treatment processes should be assessed for their abilities to remove dissolved toxic salts and ions.

  16. QUALITY OF LIFE AT WORK: A STUDY OF WORKERS IN THE METALWORKING INDUSTRY IN THE MIDWEST OF SANTA CATARINA

    Directory of Open Access Journals (Sweden)

    G. Lunardelli

    2017-08-01

    Full Text Available This study aimed to evaluate the quality of life of workers in the metalworking industry in the middle west of Santa Catarina. Therefore, we opted for a qualitative approach to know the aspects that guide and characterize female employment in the labor market, and was carried out a survey to know the reality faced by this group. It is important to emphasize the importance of companies adopt different methods and practices to adapt the working environment and conditions provide rights similar to those of men. Thus, the article addressed the inclusion of women in the workplace, treating the historical context of the feminization of the labor market, the gender division and inequality between genders in this sector. Still, women's insertion in the mechanical metal sector in the middle West Santa Catarina region was analyzed, and the preservation of their rights and appreciation while working. Although women have gained greater participation within organizations, they face wage differences, behavioral and quality of life that need to be better studied.

  17. Functional diversity and dynamics of bacterial communities in a membrane bioreactor for the treatment of metal-working fluid wastewater.

    Science.gov (United States)

    Grijalbo, Lucía; Garbisu, Carlos; Martín, Iker; Etxebarria, Javier; Gutierrez-Mañero, F Javier; Lucas Garcia, Jose Antonio

    2015-12-01

    An extensive microbiological study has been carried out in a membrane bioreactor fed with activated sludge and metal-working fluids. Functional diversity and dynamics of bacterial communities were studied with different approaches. Functional diversity of culturable bacterial communities was studied with different Biolog™ plates. Structure and dynamics of bacterial communities were studied in culturable and in non-culturable fractions using a 16S rRNA analysis. Among the culturable bacteria, Alphaproteobacteria and Gammaproteobacteria were the predominant classes. However, changes in microbial community structure were detected over time. Culture-independent analysis showed that Betaproteobacteria was the most frequently detected class in the membrane bioreactor (MBR) community with Zoogloea and Acidovorax as dominant genera. Also, among non-culturable bacteria, a process of succession was observed. Longitudinal structural shifts observed were more marked for non-culturable than for culturable bacteria, pointing towards an important role in the MBR performance. Microbial community metabolic abilities assessed with Biolog™ Gram negative, Gram positive and anaerobic plates also showed differences over time for Shannon's diversity index, kinetics of average well colour development, and the intensely used substrates by bacterial community in each plate.

  18. A combined cultivation and cultivation-independent approach shows high bacterial diversity in water-miscible metalworking fluids.

    Science.gov (United States)

    Lodders, Nicole; Kämpfer, Peter

    2012-06-01

    Ten metalworking fluids (MWF) and seven water preparation basis samples (WPB) were taken from five industrial plants in Germany. Total cells (TCC) and colony forming units (CFU) were counted, strains were isolated and their 16S rRNA gene was sequenced. Additionally, DNA was extracted directly from the samples, and clone libraries of 16S rRNA genes were built and gene sequenced. TCC ranged from 7.6×10(4) TCC/mL MWF to 1.6×10(8) TCC/mL MWF, and from 4.6×10(2) TCC/mL WPB to 7.8×10(7) TCC/mL WPB. The CFU showed similar but often lower results. A total of 70 isolates and 732 clones were 16S rRNA gene sequenced and all isolates, as well as 183 of the nearly full length 16S rRNA of these clones, were gene sequenced. A total of 98 different genera were detected in all 17 samples. The number of genera within each sample varied highly, with 1-22 genera per sample. The dominant genera in MWF were Leucobacter, Desemzia, Sphingomonas and Wautersiella. From these, only Sphingomonas was detected in WPB as well. This study showed that MWF can harbour a high bacterial diversity, which differs significantly from the bacterial flora of the corresponding WPB.

  19. A portable electronic system for in-situ measurements of oil concentration in MetalWorking fluids

    CERN Document Server

    Grossi, M

    2016-01-01

    MetalWorking Fluids (MWFs) are widely used to cool and lubricate machines and tools. By far, the most common MWFs are oil-in-water emulsions with oil concentration (C oil) in the range from 1% to 10%, depending on type of oil, material to be worked, etc. In order to optimize emulsion and machine performance, as well as for good waste policy, the right value of C oil should be kept (approximately) constant during the MWF's lifecycle to compensate inevitable changes due to water evaporation, bacterial attack, oil adhesion to metal parts, etc.. This, however, requires periodic measurements, often skipped because they require unhandy operations and produce inaccurate results. In this context, a new system is presented that is based on the falling ball principle, normally used for viscosity measurements, shown to be suitable also for accurate C oil measurements. In our system, the transit time of the sphere within the instrument is determined by means of inductive proximity sensors, a PT100 sensor is used for temp...

  20. On Solving TM0n Modal Excitation in a Ka-Band Overmoded Circular Waveguide by the Conservation of Complex Power Technique

    Institute of Scientific and Technical Information of China (English)

    Feng Lan; Xi Gao; Zong-Jun Shi

    2009-01-01

    To measure the radiation properties of relativistic diffraction generator (RDG) in Ka-band, a TM0n modal excitation model is established, which consists of an overmoded circular waveguide and a coaxial line feeding probe. Using the transverse E-field mode matching and the conservation of complex power technique (CCPT), we deduce the scattering matrix at coaxial line to coaxial line and coaxial line to circular waveguide junctions. Then using the overall cascaded junction scattering matrix, the numerical results for the reflection coefficient of the coaxial line and the power distribution of TM0n multi-modal are presented. The numerical results are in agreement with HFSS simulation results and experimental results. The analysis shows that by choosing the appropriate position of coaxial line probe, the power proportion of the device operating mode excited in circular waveguide could be the largest.

  1. Variable and Value Ordering When Solving Balanced Academic Curriculum Problems

    OpenAIRE

    Castro, Carlos; Manzano, Sebastian

    2001-01-01

    In this paper we present the use of Constraint Programming for solving balanced academic curriculum problems. We discuss the important role that heuristics play when solving a problem using a constraint-based approach. We also show how constraint solving techniques allow to very efficiently solve combinatorial optimization problems that are too hard for integer programming techniques.

  2. Exposure to metal-working fluids in the automobile industry and the risk of male germ cell tumours.

    Science.gov (United States)

    Behrens, Thomas; Pohlabeln, Hermann; Mester, Birte; Langner, Ingo; Schmeisser, Nils; Ahrens, Wolfgang

    2012-03-01

    In a previous analysis of a case-control study of testicular cancer nested in a cohort of automobile workers, we observed an increased risk for testicular cancer among workers who had ever been involved in occupational metal-cutting tasks. We investigated whether this risk increase was due to exposure to metal-working fluids (MWF). Occupational exposure to MWF was assessed in detail using a job-specific questionnaire for metal-cutting work. We calculated ORs and associated 95% CIs individually matched for age (±2 years) and adjusted for a history of cryptorchidism by conditional logistic regression. The prevalence of exposure to MWF was 39.8% among cases and 40.1% among controls. For total germ cell tumours and seminomas we did not observe risk increases for metal-cutting tasks or occupational exposure to MWF (OR 0.95; 95% CI 0.69 to 1.32 and OR 0.88; 95% CI 0.58 to 1.35, respectively). However, dermal exposure to oil-based MWF was associated with an increased risk for non-seminomatous testicular cancer. Dermal exposure to oil-based MWF for more than 5000 h showed particularly high risk estimates (OR 4.72; 95% CI 1.48 to 15.09). Long-term dermal exposure to oil-based MWF was a risk factor for the development of non-seminomatous testicular germ cell cancer. Possible measures to reduce exposure include the introduction of engineering control measures such as venting or enclosing of machines, and enforcing the use of personal protective equipment during metal cutting.

  3. Purification and characterization of an alkaline lipase from Pseudomonas aeruginosa isolated from putrid mineral cutting oil as component of metalworking fluid.

    Science.gov (United States)

    Karadzic, Ivanka; Masui, Akihiko; Zivkovic, Lidija Izrael; Fujiwara, Nobuaki

    2006-08-01

    Extracellular lipase was isolated and purified from the culture broth of Pseudomonas aeruginosa, an extremophile which naturally grows in water-soluble mineral cutting oil (pH 10) used as metalworking fluid (MWF) for cooling and lubrication in industrial metalworking processes. The molecular mass of the purified lipase was estimated by SDS-PAGE to be 54 kDa. The optimum pH and temperature were 11 and 70 degrees C, respectively. The enzyme is stabile over a broad pH range (pH 4-11.5). The lipase preferably acted on triacylglycerols with medium-chain fatty acids. The lipase was inhibited strongly by Zn(2+), Hg(2+), Cu(2+) and slightly by Ca(2+) and Mg(2+). Non-ionic detergents and sodiumdeoxycholate enhanced lipase activity. Alkaline lipase from P. aeruginosa, capable of growing in a water-restricted medium has excellent properties and good potential for biotechnological applications in the metal industry. Its marked stability and activity in organic solvents suggest that this lipase is highly suitable as a biotechnological tool in a water-restricted medium with a variety of applications including organosynthetic reactions and the control and prevention of MWF putrification in the metal industry.

  4. Pre-Service Class Teacher' Ability in Solving Mathematical Problems and Skills in Solving Daily Problems

    Science.gov (United States)

    Aljaberi, Nahil M.; Gheith, Eman

    2016-01-01

    This study aims to investigate the ability of pre-service class teacher at University of Petrain solving mathematical problems using Polya's Techniques, their level of problem solving skills in daily-life issues. The study also investigates the correlation between their ability to solve mathematical problems and their level of problem solving…

  5. Non-Fourier Heat Conduction Effects During High-Energy Beam Metalworking

    Institute of Scientific and Technical Information of China (English)

    张海泉; 张彦华; 赵海燕

    2004-01-01

    Non-Fourier heat conduction induced by ultrafast heating of metals with a high-energy density beam was analyzed. The non-Fourier effects during high heat flux heating were illustrated by comparing the transient temperature response to different heat flux and material relaxation times. Based on the hyperbolic heat conduction equation for the non-Fourier heat conduction law, the equation was solved using a hybrid method combining an analytical solution and numerical inversion of the Laplace transforms for a semi-infinite body with the heat flux boundary. Analysis of the temperature response and distribution led to a criterion for the applicability of the non-Fourier heat conduction law. The results show that at a relatively large heat flux, such as greater than 108 W/cm2, the heat-affected zone in the metal material experiences a strong thermal shock as the non-Fourier effects cause a large step increase in the surface temperature. The results provide a method for analyzing transient heat conduction problems using a high-energy density beam, such as electron beam deep penetration welding.

  6. 纺织工程卓越班学生金工实习的实践与探索%Practice and exploration of advanced metalworking practice to textile engineering excellence program students

    Institute of Scientific and Technical Information of China (English)

    王进美; 樊增禄; 南宏正; 卫建刚; 高养民; 刘华明; 同宏峰

    2013-01-01

    According to the requirements of Excellence Engineer T raining Program ,a series of curriculum reform of metalworking practice for textile engineering excellence program students were undertaken .In the lathe work and fitter based training part ,deepen the content of practice ,using lifting training intensi-ty ,to expand their knowledge and to temper the will .In the section of digital control technique ,caster , welder ,miller and planer ,many kinds of innovative product ,such as Chinese cruise ship ,progressional five rings ,and alarm device of anti-welding of sheet metal in welding were designed and made by team or individual .T he innovation and practice training has achieved significant results .%按照国家卓越工程师培养计划的要求,对纺织工程卓越计划班金工实习内容进行了一系列课程改革。在车工、钳工等基础实训部分,加深了实习内容,利用提升实训强度,达到拓展知识面,磨炼意志的目的。在数控、铸、焊、铣、刨等工段,在完成正常实训任务的基础上,利用时间弹性控制,实现各类创新产品的设计制作,依靠团队或个人的智慧,设计制作了中国式巡航舰、前进的五环、气焊防薄板熔穿报警装置等日用与工艺制品,取得了显著的创新实训效果。

  7. A Technique of Distal Clavicle Fracture Fixation Using The Tightrope Procedure

    Directory of Open Access Journals (Sweden)

    CJ Soh

    2011-11-01

    Full Text Available We present here a technique of fracture stabilization using the Tightrope procedure in a patient with a widely displaced Neer type IIB distal clavicle fracture. The Tightrope system, typically used for stabilization of acromioclavicular joint dislocation, has not been widely described for distal clavicle fractures. The patient achieved satisfactory results after surgery; we feel that this technique is appealing as it is simple, reproducible and avoids the complications associated with extensive metalwork. This technique may also appeal to the arthroscopic surgeon.

  8. A technique for determining the optimum mix of logistics service providers of a make-to-order supply chain by formulating and solving a constrained nonlinear cost optimization problem

    Directory of Open Access Journals (Sweden)

    Mrityunjoy Roy

    2013-04-01

    Full Text Available In this paper, a technique has been developed to determine the optimum mix of logistic service providers of a make-to-order (MTO supply chain. A serial MTO supply chain with different stages/ processes has been considered. For each stage different logistic service providers with different mean processing lead times, but same lead time variances are available. A realistic assumption that for each stage, the logistic service provider who charges more for his service consumes less processing lead time and vice-versa has been made in our study. Thus for each stage, for each service provider, a combination of cost and mean processing lead time is available. Using these combinations, for each stage, a polynomial curve, expressing cost of that stage as a function of mean processing lead time is fit. Cumulating all such expressions of cost for the different stages along with incorporation of suitable constraints arising out of timely delivery, results in the formulation of a constrained nonlinear cost optimization problem. On solving the problem using mathematica, optimum processing lead time for each stage is obtained. Using these optimum processing lead times and by employing a simple technique the optimum logistic service provider mix of the supply chain along with the corresponding total cost of processing is determined. Finally to examine the effect of changes in different parameters on the optimum total processing cost of the supply chain, sensitivity analysis has been carried out graphically.

  9. AnSBBR applied to the treatment of metalworking fluid wastewater: effect of organic and shock load.

    Science.gov (United States)

    Carvalhinha, Pedro P; Flôres, Anderson; Rodrigues, José A D; Ratusznei, Suzana M; Zaiat, Marcelo; Foresti, Eugenio

    2010-11-01

    An investigation was performed regarding the application of a mechanically stirred anaerobic sequencing batch biofilm reactor containing immobilized biomass on inert polyurethane foam (AnSBBR) to the treatment of soluble metalworking fluids to remove organic matter and produce methane. The effect of increasing organic matter and reactor fill time, as well as shock load, on reactor stability and efficiency have been analyzed. The 5-L AnSBBR was operated at 30 degrees C in 8-h cycles, agitation of 400 rpm, and treated 2.0 L effluent per cycle. Organic matter was increased by increasing the influent concentration (500, 1,000, 2,000, and 3,000 mg chemical oxygen demand (COD)/L). Fill times investigated were in the batch mode (fill time 10 min) and fed-batch followed by batch (fill time 4 h). In the batch mode, organic matter removal efficiencies were 87%, 86%, and 80% for influent concentrations of 500, 1,000, and 2,000 mgCOD/L (1.50, 3.12, and 6.08 gCOD/L.d), respectively. At 3,000 mgCOD/L (9.38 gCOD/L.d), operational stability could not be achieved. The reactor managed to maintain stability when a shock load twice as high the feed concentration was applied, evidencing the robustness of the reactor to potential concentration variations in the wastewater being treated. Increasing the fill time to 4 h did not improve removal efficiency, which was 72% for 2,000 mgCOD/L. Thus, gradual feeding did not improve organic matter removal. The concentration of methane formed at 6.08 gCOD/L was 5.20 mmolCH(4), which corresponded to 78% of the biogas composition. The behavior of the reactor during batch and fed-batch feeding could be explained by a kinetic model that considers organic matter consumption, production, and consumption of total volatile acids and methane production.

  10. Problem Solving and Reasoning.

    Science.gov (United States)

    1984-02-01

    6 here Acquisition of Problem - Solving Skill . An imporrant qLestinn is how the knowledge required For solving problems in a domain such as geometry is...Neves, 0. 4. (1981). Acquisition of problem - solving skill . In J. R. Anderson (Eds), Cognitive skills and their acquisition. Hillsdale, NJ: Erlbaum...NJ: Erlbaum. Voss, J. F., Greene, T. R., Post, T. A., & Penner, B. C. (1983). Problem solving skill in the social sciences. In G. H. Bower (Ed.), The

  11. Journey into Problem Solving: A Gift from Polya

    Science.gov (United States)

    Lederman, Eric

    2009-01-01

    In "How to Solve It", accomplished mathematician and skilled communicator George Polya describes a four-step universal solving technique designed to help students develop mathematical problem-solving skills. By providing a glimpse at the grace with which experts solve problems, Polya provides definable methods that are not exclusive to…

  12. Journey into Problem Solving: A Gift from Polya

    Science.gov (United States)

    Lederman, Eric

    2009-01-01

    In "How to Solve It", accomplished mathematician and skilled communicator George Polya describes a four-step universal solving technique designed to help students develop mathematical problem-solving skills. By providing a glimpse at the grace with which experts solve problems, Polya provides definable methods that are not exclusive to…

  13. Computer-Based Assessment of Problem Solving.

    Science.gov (United States)

    Baker, E. L.; Mayer, R. E.

    1999-01-01

    Examines the components required to assess student problem solving in technology environments. Discusses the purposes of testing, provides an example demonstrating the difference between retention and transfer, defines and analyzes problem solving, and explores techniques and standards for measuring the quality of student understanding. Contains…

  14. 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

  15. Performance testing of NIOSH Method 5524/ASTM Method D-7049-04, for determination of metalworking fluids.

    Science.gov (United States)

    Glaser, Robert; Kurimo, Robert; Shulman, Stanley

    2007-08-01

    A performance test of NIOSH Method 5524/ASTM Method D-7049-04 for analysis of metalworking fluids (MWF) was conducted. These methods involve determination of the total and extractable weights of MWF samples; extractions are performed using a ternary blend of toluene:dichloromethane:methanol and a binary blend of methanol:water. Six laboratories participated in this study. A preliminary analysis of 20 blank samples was made to familiarize the laboratories with the procedure(s) and to estimate the methods' limits of detection/quantitation (LODs/LOQs). Synthetically generated samples of a semisynthetic MWF aerosol were then collected on tared polytetrafluoroethylene (PTFE) filters and analyzed according to the methods by all participants. Sample masses deposited (approximately 400-500 micro g) corresponded to amounts expected in an 8-hr shift at the NIOSH recommended exposure levels (REL) of 0.4 mg/m(3) (thoracic) and 0.5 mg/m(3) (total particulate). The generator output was monitored with a calibrated laser particle counter. One laboratory significantly underreported the sampled masses relative to the other five labs. A follow-up study compared only gravimetric results of this laboratory with those of two other labs. In the preliminary analysis of blanks; the average LOQs were 0.094 mg for the total weight analysis and 0.136 mg for the extracted weight analyses. For the six-lab study, the average LOQs were 0.064 mg for the total weight analyses and 0.067 mg for the extracted weight analyses. Using ASTM conventions, h and k statistics were computed to determine the degree of consistency of each laboratory with the others. One laboratory experienced problems with precision but not bias. The precision estimates for the remaining five labs were not different statistically (alpha = 0.005) for either the total or extractable weights. For all six labs, the average fraction extracted was > or =0.94 (CV = 0.025). Pooled estimates of the total coefficients of variation of

  16. Metalworking with ultrasonic energy

    Science.gov (United States)

    Sonea, I.; Minca, M.

    1974-01-01

    The application of ultrasonic radiation for metal working of steel is discussed. It is stated that the productivity of the ultrasonic working is affected by the hardness of the material to be worked, the oscillation amplitude, the abrasive temperature, and the grain size. The factors that contribute to an increase in the dislocation speed are analyzed. Experimental data are provided to substantiate the theoretical parameters.

  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. Solving higher curvature gravity theories

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Sumanta [IUCAA, Pune (India); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Theoretical Physics Department, Kolkata (India)

    2016-10-15

    Solving field equations in the context of higher curvature gravity theories is a formidable task. However, in many situations, e.g., in the context of f(R) theories, the higher curvature gravity action can be written as an Einstein-Hilbert action plus a scalar field action. We show that not only the action but the field equations derived from the action are also equivalent, provided the spacetime is regular. We also demonstrate that such an equivalence continues to hold even when the gravitational field equations are projected on a lower-dimensional hypersurface. We have further addressed explicit examples in which the solutions for Einstein-Hilbert and a scalar field system lead to solutions of the equivalent higher curvature theory. The same, but on the lower-dimensional hypersurface, has been illustrated in the reverse order as well. We conclude with a brief discussion on this technique of solving higher curvature field equations. (orig.)

  19. 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.

  20. Solving tooth sensitivity.

    Science.gov (United States)

    Miller, Michael B

    2010-01-01

    Solving tooth sensitivity requires both you and the patients to be resilient and to understand that if one approach doesn't work, you can try another one that is non-invasive or, at worst, minimally invasive. Much like the clinician who posted the original question, I strongly believe that it is our responsibility to convince patients that jumping to a radical solution could be totally unnecessary--and expensive-- and still might not solve the problem.

  1. Stochastic Optimization Approaches for Solving Sudoku

    CERN Document Server

    Perez, Meir

    2008-01-01

    In this paper the Sudoku problem is solved using stochastic search techniques and these are: Cultural Genetic Algorithm (CGA), Repulsive Particle Swarm Optimization (RPSO), Quantum Simulated Annealing (QSA) and the Hybrid method that combines Genetic Algorithm with Simulated Annealing (HGASA). The results obtained show that the CGA, QSA and HGASA are able to solve the Sudoku puzzle with CGA finding a solution in 28 seconds, while QSA finding a solution in 65 seconds and HGASA in 1.447 seconds. This is mainly because HGASA combines the parallel searching of GA with the flexibility of SA. The RPSO was found to be unable to solve the puzzle.

  2. Partial differential equations theory and completely solved problems

    CERN Document Server

    Hillen, Thomas; van Roessel, Henry

    2014-01-01

    Uniquely provides fully solved problems for linear partial differential equations and boundary value problems Partial Differential Equations: Theory and Completely Solved Problems utilizes real-world physical models alongside essential theoretical concepts. With extensive examples, the book guides readers through the use of Partial Differential Equations (PDEs) for successfully solving and modeling phenomena in engineering, biology, and the applied sciences. The book focuses exclusively on linear PDEs and how they can be solved using the separation of variables technique. The authors begin

  3. Clarification and filtration of the floculated partuicles suspension from a chemical treatment of waste oil-in-water emulsions from a non-ferrous metalworking plant

    Directory of Open Access Journals (Sweden)

    Lazarević Vesna B.

    2011-01-01

    Full Text Available The effects of the coagulation/floculation conditions on clarification and filtration of the floculated particle suspension obtained by the chemical treatment of the waste oil-in-water emulsion (OWE from a non-ferrous metalworking plant were studied. The treatment involved the addition of aluminum(III sulfate and lime to the OWE. The main goal was to define the optimum conditions for clarification and filtration of the floculated particle suspension. The factors involved were amounts lime (i.e. pH and filter aid added the OWE on clarification and filtration rates. At pH>10, the clarification rate was increased and the final volume of the concentrated suspension (sludge was reduced, while filter aid affected negatively the clarification rate. The filtration rate was also increased when the coagulation was carried out at pH>10. The floculated particle suspension should be concentrated before filtration in order to decrease the filtration duration. The most efficient filter aid was Celite standard super-cel, its optimum initial concentration being found to be 2 g/dm3.

  4. Occupational exposure to mineral oil metalworking fluid (MWFs) mist: Development of new methodologies for mist sampling and analysis. Results from an inter-laboratory comparison

    Science.gov (United States)

    Khanh Huynh, C.; Herrera, H.; Parrat, J.; Wolf, R.; Perret, V.

    2009-02-01

    Metalworking Fluids (MWFs) are largely used in the sector of undercutting, a large professional activity in Switzerland, in particular in the fine mechanic and watch making industry. France proposes a Permissible Exposure Limit (PEL) of 1 mg.m-3 of aerosol. The American Conference of Governmental Industrial Hygienists (ACGIH) sets its value at 5 mg.m-3 but a proposal to lower the standard ("intended changes") to 0.2 mg.m-3 of aerosol is pending since 2001. However, it has not become a recognized threshold limit value for exposure. Since 2003, the new Swiss PEL (MAK) recommendations would be 0.2 mg.m-3 of aerosol (oil with boiling point > 350°C without additives) and/or 20 mg.m-3 of oil aerosol + vapour for medium or light oil. To evaluate evaporative losses of sampled oil, the German "Berufsgenossenschaftliches Institut für Arbeitssicherheit" (BGIA) recommends the use of a XAD-2 cartridge behind the filter. The method seems to work perfectly for MWFs in a clean occupational atmosphere free from interference of light vapour cleaning solvent such as White Spirit. But, in real situation, machine shop atmosphere contaminated with traces of White Spirit, the BGIA method failed to estimate the MWFs levels (over-estimation). In this paper, we propose a new approach meant to measure both oil vapours and aerosols. Five inter-laboratory comparisons are discussed, based on the production of oil mist in an experimental chamber under controlled conditions.

  5. Problem Solving Using Microcomputers.

    Science.gov (United States)

    Demana, Franklin; Waits, Bert

    1987-01-01

    It is argued that microcomputer technology has evolved to the stage that it should be routinely used by mathematics students at all levels. It is shown how the use of microcomputers can change the way problems are solved. Computer-generated graphics are highlighted. (PK)

  6. 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…

  7. 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…

  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. 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)

  10. Electric Current Solves Mazes

    Science.gov (United States)

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  11. Universal Design Problem Solving

    Science.gov (United States)

    Sterling, Mary C.

    2004-01-01

    Universal design is made up of four elements: accessibility, adaptability, aesthetics, and affordability. This article addresses the concept of universal design problem solving through experiential learning for an interior design studio course in postsecondary education. Students' experiences with clients over age 55 promoted an understanding of…

  12. 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...

  13. 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.

  14. 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....

  15. 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...

  16. 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....

  17. Transform methods for solving partial differential equations

    CERN Document Server

    Duffy, Dean G

    2004-01-01

    Transform methods provide a bridge between the commonly used method of separation of variables and numerical techniques for solving linear partial differential equations. While in some ways similar to separation of variables, transform methods can be effective for a wider class of problems. Even when the inverse of the transform cannot be found analytically, numeric and asymptotic techniques now exist for their inversion, and because the problem retains some of its analytic aspect, one can gain greater physical insight than typically obtained from a purely numerical approach. Transform Methods for Solving Partial Differential Equations, Second Edition illustrates the use of Laplace, Fourier, and Hankel transforms to solve partial differential equations encountered in science and engineering. The author has expanded the second edition to provide a broader perspective on the applicability and use of transform methods and incorporated a number of significant refinements: New in the Second Edition: ·...

  18. Tree Searching and Student Problem Solving

    Science.gov (United States)

    Alderman, Donald L.

    1978-01-01

    Tree searching was applied as a computer model of simple addition sentences. Results indicated that the number of problem reductions performed in tree searching accounted for most of the variance across problems in student error rate and solution time. The technique constitutes a computer test for the adequacy of a problem solving prescription.…

  19. 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

  20. MULTILEVEL AUGMENTATION METHODS FOR SOLVING OPERATOR EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    Chen Zhongying; Wu Bin; Xu Yuesheng

    2005-01-01

    We introduce multilevel augmentation methods for solving operator equations based on direct sum decompositions of the range space of the operator and the solution space of the operator equation and a matrix splitting scheme. We establish a general setting for the analysis of these methods, showing that the methods yield approximate solutions of the same convergence order as the best approximation from the subspace. These augmentation methods allow us to develop fast, accurate and stable nonconventional numerical algorithms for solving operator equations. In particular, for second kind equations, special splitting techniques are proposed to develop such algorithms. These algorithms are then applied to solve the linear systems resulting from matrix compression schemes using wavelet-like functions for solving Fredholm integral equations of the second kind. For this special case, a complete analysis for computational complexity and convergence order is presented. Numerical examples are included to demonstrate the efficiency and accuracy of the methods. In these examples we use the proposed augmentation method to solve large scale linear systems resulting from the recently developed wavelet Galerkin methods and fast collocation methods applied to integral equations of the secondkind. Our numerical results confirm that this augmentation method is particularly efficient for solving large scale linear systems induced from wavelet compression schemes.

  1. Solving Differential Equations in R: Package deSolve

    NARCIS (Netherlands)

    Soetaert, K.E.R.; Petzoldt, T.; Setzer, R.W.

    2010-01-01

    In this paper we present the R package deSolve to solve initial value problems (IVP) written as ordinary differential equations (ODE), differential algebraic equations (DAE) of index 0 or 1 and partial differential equations (PDE), the latter solved using the method of lines approach. The differenti

  2. 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. .

  3. Methods of solving sequence and series problems

    CERN Document Server

    Grigorieva, Ellina

    2016-01-01

    This book aims to dispel the mystery and fear experienced by students surrounding sequences, series, convergence, and their applications. The author, an accomplished female mathematician, achieves this by taking a problem solving approach, starting with fascinating problems and solving them step by step with clear explanations and illuminating diagrams. The reader will find the problems interesting, unusual, and fun, yet solved with the rigor expected in a competition. Some problems are taken directly from mathematics competitions, with the name and year of the exam provided for reference. Proof techniques are emphasized, with a variety of methods presented. The text aims to expand the mind of the reader by often presenting multiple ways to attack the same problem, as well as drawing connections with different fields of mathematics. Intuitive and visual arguments are presented alongside technical proofs to provide a well-rounded methodology. With nearly 300 problems including hints, answers, and solutions,Met...

  4. Insightful problem solving in an Asian elephant.

    Directory of Open Access Journals (Sweden)

    Preston Foerder

    Full Text Available The "aha" moment or the sudden arrival of the solution to a problem is a common human experience. Spontaneous problem solving without evident trial and error behavior in humans and other animals has been referred to as insight. Surprisingly, elephants, thought to be highly intelligent, have failed to exhibit insightful problem solving in previous cognitive studies. We tested whether three Asian elephants (Elephas maximus would use sticks or other objects to obtain food items placed out-of-reach and overhead. Without prior trial and error behavior, a 7-year-old male Asian elephant showed spontaneous problem solving by moving a large plastic cube, on which he then stood, to acquire the food. In further testing he showed behavioral flexibility, using this technique to reach other items and retrieving the cube from various locations to use as a tool to acquire food. In the cube's absence, he generalized this tool utilization technique to other objects and, when given smaller objects, stacked them in an attempt to reach the food. The elephant's overall behavior was consistent with the definition of insightful problem solving. Previous failures to demonstrate this ability in elephants may have resulted not from a lack of cognitive ability but from the presentation of tasks requiring trunk-held sticks as potential tools, thereby interfering with the trunk's use as a sensory organ to locate the targeted food.

  5. A comparison of the Method of Lines to finite difference techniques in solving time-dependent partial differential equations. [with applications to Burger equation and stream function-vorticity problem

    Science.gov (United States)

    Kurtz, L. A.; Smith, R. E.; Parks, C. L.; Boney, L. R.

    1978-01-01

    Steady state solutions to two time dependent partial differential systems have been obtained by the Method of Lines (MOL) and compared to those obtained by efficient standard finite difference methods: (1) Burger's equation over a finite space domain by a forward time central space explicit method, and (2) the stream function - vorticity form of viscous incompressible fluid flow in a square cavity by an alternating direction implicit (ADI) method. The standard techniques were far more computationally efficient when applicable. In the second example, converged solutions at very high Reynolds numbers were obtained by MOL, whereas solution by ADI was either unattainable or impractical. With regard to 'set up' time, solution by MOL is an attractive alternative to techniques with complicated algorithms, as much of the programming difficulty is eliminated.

  6. Do Scaffolded Supports between Aspects of Problem Solving Enhance Assessment Usability?

    Science.gov (United States)

    McCoy, Jan D.; Braun-Monegan, Jenelle; Bettesworth, Leanne; Tindal, Gerald

    2015-01-01

    While problem solving as an instructional technique is widely advocated, educators are often challenged in effectively assessing student skill in this area. Students failing to solve a problem might fail in any of several aspects of the effort. The purpose of this research was to validate a scaffolded technique for assessing problem solving in…

  7. Association between use of synthetic metalworking fluid and risk of developing rhinitis-related symptoms in an automotive ring manufacturing plant.

    Science.gov (United States)

    Park, Dong-Uk; Jin, Ku-Won; Koh, Dong-Hee; Kim, Byung-Kyu; Kim, Kyu-Sang; Park, Doo-Yong

    2008-01-01

    The main objective of this study was to determine the association between synthetic metalworking fluid (MWF) and rhinitis-related symptoms. At a plant manufacturing piston rings for automobiles, we interviewed grinders (19) and manufacturing workers (142) in operations where synthetic or semisynthetic MWF is handled, and administrative office workers (44) regarding the principal symptoms of rhinitis (nasal stuffiness, runny nose, anosmia, nasal itchiness, rhinorrhea, headache, epistaxis, and post-nasal drip). In addition, we assessed the current exposure of workers handling MWF to MWF aerosols, fungi, and endotoxins. Logistic regression analysis was used to examine the association between MWF surrogates indicative of MWF exposure and each rhinitis-related nasal symptom. Odds ratios (ORs) and 95% confidence intervals were adjusted for sex, age, smoking habit, and duration of employment. Among grinders handling synthetic MWF, the frequency of complaints of the dominant symptoms was 66.7% for nasal stuffiness, 77.8% for anosmia, 77.8% for runny nose, and 50.0% for headache. These rates are quite high even allowing for the common occurrence of rhinitis in the general population. Twenty eight of 34 grinding and manufacturing workers (82.4%) sampled were exposed to MWF mist above the threshold limit of 0.2 mg/m(3) listed as a notice of intended change by the American Conference for Governmental Industrial Hygienists (ACGIH). The percentage of workers exposed to MWF mist >0.5 mg/m(3) was 17.6%. Most workers were exposed to fungi levels >103 CFU/m(3). All exposures to endotoxins were risk of nasal stuffiness (OR 3.5), nasal itchiness (OR 2.0), and runny nose (OR 2.1). The use of semi-synthetic MWF had little or no impact on the risk of developing rhinitis-related nasal symptoms. Grinding workers handling synthetic MWF had an increased risk of nasal stuffiness (OR 7.9), anosmia (OR 23.2), nasal itchiness (OR 8.3), runny nose (OR 20.4), post nasal drip (OR 18.4), and

  8. INNOVATIVE INSTRUMENTS FOR STIMULATING CREATIVITY AND PROBLEM SOLVING

    OpenAIRE

    Octav Dumitru DAFINOIU

    2015-01-01

    Abstract The creation of knowledge, the advanced research in strategic directions, the increasing of economic competitiveness and the transfer of knowledge in the economy are priorities of economic policies. They are based on research, development and innovation activities, which although take various shapes, have something in common: they relate to problem solving. Strategies, methods and techniques used in order to find solutions for problems are based on problem solving techniques taken f...

  9. PERBANDINGAN HASIL BELAJAR DISCOVERY LEARNING BERBASIS PROBLEM SOLVING DAN GROUP INVESTIGATION BERBASIS PROBLEM SOLVING PADA PEMBELAJARAN METODE NUMERIK

    Directory of Open Access Journals (Sweden)

    Ira Vahlia

    2016-06-01

    Full Text Available Discovery learning is a learning that involves students in the process of mental activity through a brainstorm, to discuss, and try it yourself, so that children can learn to be independent. Resulting in the discovery-based learning problem solving is to let children discover things on their own and group investigation that emphasizes problem solving based on a debriefing activities and student participation. The classes drawn into the sample, the class as a class given control based discovery learning and problem solving one class another group investigation given learning-based problem solving. Data analysis techniques in this study using Ttes. From the results of this study concluded that: (a In the first experiment class that implements learning model-based problem solving group investigation obtained average value of learning outcomes at 73.10 while the experimental class II implementing discovery-based learning problem solving obtained average value postest average of 66.55. (b There are significant differences between the results of student learning in the class that implements the discovery-based learning and problem solving class that implements the learning model based problem solving group investigation. Student results in learning problem solving based group investigation better on the class that implements the model-based discovery learning problem solving.  Keywords: discovery learning, group investigation, learning numerical methods,  problem solving

  10. 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.

  11. 当前铁路隧道施工亟待解决的若干技术问题%Technique Problems Need to be Solved Urgently in Current Railway Tunnel Construction

    Institute of Scientific and Technical Information of China (English)

    马辉; 刘仁智; 陈寿根; 高明忠

    2011-01-01

    Tunneling in high-speed railways is characterized by high construction standards, great construction difficulties, high safety risks and strict construction management requirements. Taking the Cuiguang high-speed railway as an example, this paper analyzes several key problems that restrict construction efficiency and safety. Based on the current technical status of domestic railway tunnel construction, some conclusions were drawn: 1) Excavation with the micro bench method utilizing precise blasting technology can solve the contradiction between excavation advancement and keeping a safe distance between different processes for rocks class IV and V; 2) Trackless transportation, which benefits from the progress of ventilation technology and air purification technology, is applicable to the construction of long tunnels with large sections; 3) Developing and applying fast construction equipment for tunnel invert construction and movable formworks for the construction of water ditches and cable grooves filled a gap in this field; and 4) Information-oriented construction is the trend of tunnel construction technology development in the future.%高速铁路隧道工程建设标准高,施工难度大,安全风险高,施工管理要求严格.文章以贵广铁路隧道工程为实例,结合当前国内隧道施工技术现状和贵广铁路隧道创新技术的现场实践,研究分析了制约隧道施工安全和施工效率的突出技术问题,取得了一系列研究成果:①基于精细爆破技术的微台阶开挖工艺可有效解决Ⅳ、Ⅴ级围岩隧道开挖进度与工序安全距离之间的矛盾;②得益于通风技术和空气净化技术的进步,无轨运输方式可以适应于长大隧道的施工;③隧道仰拱快速施工设备和隧道沟槽移动模架的开发应用填补了这一领域的空白;④信息化施工是未来遂道施工技术发展的大趋势.

  12. 采用聚能爆破技术治理岩爆灾害的试验研究%Experimental investigation on solving rock burst problem by assembling energy blasting technique

    Institute of Scientific and Technical Information of China (English)

    陈清运; 邓雄; 刘美山; 王飞跃; 姜均文

    2011-01-01

    Rock burst is a big disaster for underground engineering, and releasing high crustal stress at stress concentration positions by blasting technique could decrease rock burst harm availably. Assembling energy blasting has unique advantages, such as small-charge and good effects of carving groove and forming slot. The paper analyzed the feasibility of decreasing rock burst by adopting assembling energy blasting technique, and carried through the comparative trial of shallow hole and well hole assembling energy blasting, combining with rock burst problem of priming tunnel at Jinping power station. The research indicated the effect of carving groove and forming slot by assembling energy blasting was better than that by pre-splitting blasting. It is feasible to adopt assembling energy blasting to decrease rock burst.%岩爆是地下工程一大灾害,在应力集中的部位,采用爆破方法释放高地应力,可以有效降低岩爆灾害.聚能爆破具有用药量小、刻槽和成缝效果好的优点.结合锦屏二级水电站引水隧硐地下工程的岩爆问题,探讨了采用聚能爆破技术降低岩爆的可行性,并进行了浅孔和深孔聚能爆破的对比试验.研究表明,聚能爆破在高地应力条件下的成缝和刻槽效果较普通预裂爆破大为提高,采用聚能爆破技术降低岩爆灾害是可行的.

  13. Multiscale empirical interpolation for solving nonlinear PDEs

    KAUST Repository

    Calo, Victor M.

    2014-12-01

    In this paper, we propose a multiscale empirical interpolation method for solving nonlinear multiscale partial differential equations. The proposed method combines empirical interpolation techniques and local multiscale methods, such as the Generalized Multiscale Finite Element Method (GMsFEM). To solve nonlinear equations, the GMsFEM is used to represent the solution on a coarse grid with multiscale basis functions computed offline. Computing the GMsFEM solution involves calculating the system residuals and Jacobians on the fine grid. We use empirical interpolation concepts to evaluate these residuals and Jacobians of the multiscale system with a computational cost which is proportional to the size of the coarse-scale problem rather than the fully-resolved fine scale one. The empirical interpolation method uses basis functions which are built by sampling the nonlinear function we want to approximate a limited number of times. The coefficients needed for this approximation are computed in the offline stage by inverting an inexpensive linear system. The proposed multiscale empirical interpolation techniques: (1) divide computing the nonlinear function into coarse regions; (2) evaluate contributions of nonlinear functions in each coarse region taking advantage of a reduced-order representation of the solution; and (3) introduce multiscale proper-orthogonal-decomposition techniques to find appropriate interpolation vectors. We demonstrate the effectiveness of the proposed methods on several nonlinear multiscale PDEs that are solved with Newton\\'s methods and fully-implicit time marching schemes. Our numerical results show that the proposed methods provide a robust framework for solving nonlinear multiscale PDEs on a coarse grid with bounded error and significant computational cost reduction.

  14. 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

  15. 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...

  16. Program Transformation by Solving Equations

    Institute of Scientific and Technical Information of China (English)

    朱鸿

    1991-01-01

    Based on the theory of orthogonal program expansion[8-10],the paper proposes a method to transform programs by solving program equations.By the method,transformation goals are expressed in program equations,and achieved by solving these equations.Although such equations are usually too complicated to be solved directly,the orthogonal expansion of programs makes it possible to reduce such equations into systems of equations only containing simple constructors of programs.Then,the solutions of such equations can be derived by a system of solving and simplifying rules,and algebraic laws of programs.The paper discusses the methods to simplify and solve equations and gives some examples.

  17. Pulsating Star Mystery Solved

    Science.gov (United States)

    2010-11-01

    By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory is spot on, while the prediction from stellar evolution theory is at odds with the new observations. The new results, from a team led by Grzegorz Pietrzyński (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), appear in the 25 November 2010 edition of the journal Nature. Grzegorz Pietrzyński introduces this remarkable result: "By using the HARPS instrument on the 3.6-metre telescope at ESO's La Silla Observatory in Chile, along with other telescopes, we have measured the mass of a Cepheid with an accuracy far greater than any earlier estimates. This new result allows us to immediately see which of the two competing theories predicting the masses of Cepheids is correct." Classical Cepheid Variables, usually called just Cepheids, are unstable stars that are larger and much brighter than the Sun [1]. They expand and contract in a regular way, taking anything from a few days to months to complete the cycle. The time taken to brighten and grow fainter again is longer for stars that are more luminous and shorter for the dimmer ones. This remarkably precise relationship makes the study of Cepheids one of the most effective ways to measure the distances to nearby galaxies and from there to map out the scale of the whole Universe [2]. Unfortunately, despite their importance, Cepheids are not fully understood. Predictions of their masses derived from the theory of pulsating stars are 20-30% less than predictions from the theory of the

  18. A Heuristic Approach to Innovative Problem Solving

    Directory of Open Access Journals (Sweden)

    Bertil Hök

    2017-03-01

    Full Text Available A methodic approach to innovative problem solving is suggested. First, Bayesian techniques are analyzed for quantifying, monitoring and predicting the process. The symmetry of Bayes‟ theorem implicates that the chances of success offrail ideas with small base rates can be boosted by highly accurate tests built on solid scientific ground. Second, a hypothesis is presented in which five methodic elements – connection, selection, transformation, balance and finish - are deemed to be necessary and sufficient to explain innovative solutions to complex problems. The hypothesis is supported by the analysis of disruptive innovations in several fields, and by emulation of a data base including 40,000 inventions.The reported findings may become useful in the further methodic development of innovative problem solving, especially in the risky and lengthy preconceptual phases

  19. Creative problem solving: an applied university course

    Directory of Open Access Journals (Sweden)

    René Victor Valqui Vidal

    2010-08-01

    Full Text Available This paper presents the principles of active learning and the contents of a creativity course entitled: Creativity and Problem Solving. The main purpose of this course is to create a space to discuss, reflect and experiment with creativity, creative processes and creative tools of relevance for students of any speciality (60% will end as operational researchers working with problem solving approaches. This course has run with big success since 1998 at the Technical University of Denmark. It started with very few students, now is a very popular course attracting many students from abroad. The selected themes, the methods and techniques, the structure of this course, the learning processes and the achieved results are presented. The results of student's and teacher's evaluations are also outlined. Finally some reflections, recommendations and conclusions are discussed.

  20. 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 to ...... to both natural, other material and to cultural conditions. Hence, solving the discard problem requires not only technical and regulatory instruments, but also arenas and structures that allow and facilitate processes of cultural change....

  1. Hats off to Problem-Solving with Couples

    Science.gov (United States)

    Li, Chi-Sing; Lin, Yu-Fen; Nelson, Judy; Eckstein, Daniel

    2008-01-01

    The purpose of this article is to demonstrate how counselors can use de Bono's Six Thinking Hats problem-solving technique in their work with couples. Part 1 of the article focuses on an introduction to the technique, including a theoretical rationale and supporting research. Following a detailed description of the process of using the model as a…

  2. 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)

  3. 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...

  4. Review of Recent Developments. Metalworking,

    Science.gov (United States)

    MATERIAL FORMING, REVIEWS), HIGH ENERGY RATE FORMING, EXTRUSION, FORGING, MECHANICAL WORKING, TITANIUM ALLOYS, ALUMINUM ALLOYS, VANADIUM ALLOYS, BERYLLIUM, CONICAL BODIES, CUTTING TOOLS , BERYLLIUM ALLOYS.

  5. An efficient method for solving fractional Hodgkin–Huxley model

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, A.M., E-mail: abdelhameed_nagy@yahoo.com [Department of Mathematics, Faculty of Science, Benha University, 13518 Benha (Egypt); Sweilam, N.H., E-mail: n_sweilam@yahoo.com [Department of Mathematics, Faculty of Science, Cairo University, 12613 Giza (Egypt)

    2014-06-13

    In this paper, we present an accurate numerical method for solving fractional Hodgkin–Huxley model. A non-standard finite difference method (NSFDM) is implemented to study the dynamic behaviors of the proposed model. The Grünwald–Letinkov definition is used to approximate the fractional derivatives. Numerical results are presented graphically reveal that NSFDM is easy to implement, effective and convenient for solving the proposed model. - Highlights: • An accurate numerical method for solving fractional Hodgkin–Huxley model is given. • Non-standard finite difference method (NSFDM) is implemented to the proposed model. • NSFDM can solve differential equations involving derivatives of non-integer order. • NDFDM is very powerful and efficient technique for solving the proposed model.

  6. SOLVE II: A Technique to Improve Efficiency and Solve Problems in Hardwood Sawmills

    Science.gov (United States)

    Edward L. Adams; Daniel E. Dunmire

    1977-01-01

    The squeeze between rising costs and product values is getting tighter for sawmill managers. So, they are taking a closer took at the efficiency of their sawmills by making a complete analysis of their milling situation. Such an analysis requires considerable time and expense. To aid the manager with this task, the USDA Forest Service's Northeastern Forest...

  7. Solving Heat and Wave-Like Equations Using He's Polynomials

    Directory of Open Access Journals (Sweden)

    Syed Tauseef Mohyud-Din

    2009-01-01

    Full Text Available We use He's polynomials which are calculated form homotopy perturbation method (HPM for solving heat and wave-like equations. The proposed iterative scheme finds the solution without any discretization, linearization, or restrictive assumptions. Several examples are given to verify the reliability and efficiency of the method. The fact that suggested technique solves nonlinear problems without using Adomian's polynomials is a clear advantage of this algorithm over the decomposition method.

  8. Multistage Spectral Relaxation Method for Solving the Hyperchaotic Complex Systems

    Directory of Open Access Journals (Sweden)

    Hassan Saberi Nik

    2014-01-01

    Full Text Available We present a pseudospectral method application for solving the hyperchaotic complex systems. The proposed method, called the multistage spectral relaxation method (MSRM is based on a technique of extending Gauss-Seidel type relaxation ideas to systems of nonlinear differential equations and using the Chebyshev pseudospectral methods to solve the resulting system on a sequence of multiple intervals. In this new application, the MSRM is used to solve famous hyperchaotic complex systems such as hyperchaotic complex Lorenz system and the complex permanent magnet synchronous motor. We compare this approach to the Runge-Kutta based ode45 solver to show that the MSRM gives accurate results.

  9. A ROBUST TRUST REGION ALGORITHM FOR SOLVING GENERAL NONLINEAR PROGRAMMING

    Institute of Scientific and Technical Information of China (English)

    Xin-wei Liu; Ya-xiang Yuan

    2001-01-01

    The trust region approach has been extended to solving nonlinear constrained optimization. Most of these extensions consider only equality constraints and require strong global regularity assumptions. In this paper, a trust region algorithm for solving general nonlinear programming is presented, which solves an unconstrained piecewise quadratic trust region subproblem and a quadratic programming trust region subproblem at each iteration. A new technique for updating the penalty parameter is introduced. Under very mild conditions, the global convergence results are proved. Some local convergence results are also proved. Preliminary numerical results are also reported.

  10. Solving Segment Routing Problems with Hybrid Constraint Programming Techniques

    OpenAIRE

    Hartert, Renaud; Schaus, Pierre; Vissicchio, Stefano; Bonaventure, Olivier; International Conference on Principles and Practice of Constraint Programming (CP2014)

    2015-01-01

    Segment routing is an emerging network technology that exploits the existence of several paths between a source and a destination to spread the traffic in a simple and elegant way. The major commercial network vendors already support segment routing, and several Internet actors are ready to use segment routing in their network. Unfortunately, by changing the way paths are computed, segment routing poses new op- timization problems which cannot be addressed with previous research contributions...

  11. Solving semi-infinite optimization problems with interior point techniques

    NARCIS (Netherlands)

    Stein, Oliver; Still, Georg

    2003-01-01

    We introduce a new numerical solution method for semi-infinite optimization problems with convex lower level problems. The method is based on a reformulation of the semi-infinite problem as a Stackelberg game and the use of regularized nonlinear complementarity problem functions. This approach leads

  12. Solving semi-infinite optimization problems with interior point techniques

    NARCIS (Netherlands)

    Stein, Oliver; Still, Georg J.

    2003-01-01

    We introduce a new numerical solution method for semi-infinite optimization problems with convex lower level problems. The method is based on a reformulation of the semi-infinite problem as a Stackelberg game and the use of regularized nonlinear complementarity problem functions. This approach leads

  13. An Exponential Finite Difference Technique for Solving Partial Differential Equations.

    Science.gov (United States)

    1987-06-01

    Transient Change," Applied Mathematical Modeling, Vol. 10, 1986. [4] Carnahan, B., Luther, H., Wilkes, J.: Applied Numerical Methods , John Wiley & Sons...THIS ROUTINE WAS TAKEN FROM THE BOOK APPLIED NUMERICAL METHODS C BY CARNAHAN, LUTHER, AND WILKES. C SUBROUTINE TRIDAG(IFLA,B,C,DDV) IMPLICIT REAL*8CA-H,O

  14. Remediation of problem-solving skills in schizophrenia: evidence of a persistent effect.

    Science.gov (United States)

    Medalia, Alice; Revheim, Nadine; Casey, Matthew

    2002-10-01

    Neuropsychological deficits in problem solving are commonly found in patients with schizophrenia. We have previously presented the results of a study examining the feasibility of utilizing problem-solving teaching techniques developed within educational psychology, for remediating the problem-solving deficits of inpatients with schizophrenia spectrum disorders. These techniques emphasize the importance of intrinsic motivation on therapeutic outcome and promote this through contextualization, personalization and control of learning activities. We present here the results of the follow-up assessment, which found that the gains made by the problem-solving group persisted for 4 weeks after cessation of problem-solving remediation ended. These results provide more evidence of the therapeutic benefit of problem-solving training techniques that promote intrinsic motivation and generic problem-solving strategies.

  15. 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.

  16. 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.

  17. Computer techniques for electromagnetics

    CERN Document Server

    Mittra, R

    1973-01-01

    Computer Techniques for Electromagnetics discusses the ways in which computer techniques solve practical problems in electromagnetics. It discusses the impact of the emergence of high-speed computers in the study of electromagnetics. This text provides a brief background on the approaches used by mathematical analysts in solving integral equations. It also demonstrates how to use computer techniques in computing current distribution, radar scattering, and waveguide discontinuities, and inverse scattering. This book will be useful for students looking for a comprehensive text on computer techni

  18. 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

  19. 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...

  20. 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

  1. 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.

  2. Quantitative Reasoning in Problem Solving

    Science.gov (United States)

    Ramful, Ajay; Ho, Siew Yin

    2015-01-01

    In this article, Ajay Ramful and Siew Yin Ho explain the meaning of quantitative reasoning, describing how it is used in the to solve mathematical problems. They also describe a diagrammatic approach to represent relationships among quantities and provide examples of problems and their solutions.

  3. 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

  4. Common Core: Solve Math Problems

    Science.gov (United States)

    Strom, Erich

    2012-01-01

    The new common core standards for mathematics demand that students (and teachers!) exhibit deeper conceptual understanding. That's music to the ears of education professor John Tapper, who says teachers have overemphasized teaching procedures--and getting right answers. In his new book, "Solving for Why," he makes a powerful case for moving beyond…

  5. Problem-Solving Test: Pyrosequencing

    Science.gov (United States)

    Szeberenyi, Jozsef

    2013-01-01

    Terms to be familiar with before you start to solve the test: Maxam-Gilbert sequencing, Sanger sequencing, gel electrophoresis, DNA synthesis reaction, polymerase chain reaction, template, primer, DNA polymerase, deoxyribonucleoside triphosphates, orthophosphate, pyrophosphate, nucleoside monophosphates, luminescence, acid anhydride bond,…

  6. 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…

  7. 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…

  8. 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…

  9. 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…

  10. Solving Differential Equations in R: Package deSolve

    Directory of Open Access Journals (Sweden)

    Karline Soetaert

    2010-02-01

    Full Text Available In this paper we present the R package deSolve to solve initial value problems (IVP written as ordinary differential equations (ODE, differential algebraic equations (DAE of index 0 or 1 and partial differential equations (PDE, the latter solved using the method of lines approach. The differential equations can be represented in R code or as compiled code. In the latter case, R is used as a tool to trigger the integration and post-process the results, which facilitates model development and application, whilst the compiled code significantly increases simulation speed. The methods implemented are efficient, robust, and well documented public-domain Fortran routines. They include four integrators from the ODEPACK package (LSODE, LSODES, LSODA, LSODAR, DVODE and DASPK2.0. In addition, a suite of Runge-Kutta integrators and special-purpose solvers to efficiently integrate 1-, 2- and 3-dimensional partial differential equations are available. The routines solve both stiff and non-stiff systems, and include many options, e.g., to deal in an efficient way with the sparsity of the Jacobian matrix, or finding the root of equations. In this article, our objectives are threefold: (1 to demonstrate the potential of using R for dynamic modeling, (2 to highlight typical uses of the different methods implemented and (3 to compare the performance of models specified in R code and in compiled code for a number of test cases. These comparisons demonstrate that, if the use of loops is avoided, R code can efficiently integrate problems comprising several thousands of state variables. Nevertheless, the same problem may be solved from 2 to more than 50 times faster by using compiled code compared to an implementation using only R code. Still, amongst the benefits of R are a more flexible and interactive implementation, better readability of the code, and access to R’s high-level procedures. deSolve is the successor of package odesolve which will be deprecated in

  11. 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.

  12. Unsupervised neural networks for solving Troesch's problem

    Science.gov (United States)

    Muhammad, Asif Zahoor Raja

    2014-01-01

    In this study, stochastic computational intelligence techniques are presented for the solution of Troesch's boundary value problem. The proposed stochastic solvers use the competency of a feed-forward artificial neural network for mathematical modeling of the problem in an unsupervised manner, whereas the learning of unknown parameters is made with local and global optimization methods as well as their combinations. Genetic algorithm (GA) and pattern search (PS) techniques are used as the global search methods and the interior point method (IPM) is used for an efficient local search. The combination of techniques like GA hybridized with IPM (GA-IPM) and PS hybridized with IPM (PS-IPM) are also applied to solve different forms of the equation. A comparison of the proposed results obtained from GA, PS, IPM, PS-IPM and GA-IPM has been made with the standard solutions including well known analytic techniques of the Adomian decomposition method, the variational iterational method and the homotopy perturbation method. The reliability and effectiveness of the proposed schemes, in term of accuracy and convergence, are evaluated from the results of statistical analysis based on sufficiently large independent runs.

  13. A PROJECTION-TYPE METHOD FOR SOLVING VARIOUS WEBER PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Jian-lin Jiang; Bo Chen

    2006-01-01

    This paper investigates various Weber problems including unconstrained Weber problems and constrained Weber problems under l1,l2 and l∞-norms. First with a transformation technique various Weber problems are turned into a class of monotone linear variational inequalities. By exploiting the favorable structure of these variational inequalities, we present a new projection-type method for them. Compared with some other projection-type methods which can solve monotone linear variational inequality, this new projection-type method is simple in numerical implementations and more efficient for solving this class of problems; Compared with some popular methods for solving unconstrained Weber problem and constrained Weber problem, a singularity would not happen in this new method and it is more reliable by using this new method to solve various Weber problems.

  14. Planning under uncertainty solving large-scale stochastic linear programs

    Energy Technology Data Exchange (ETDEWEB)

    Infanger, G. (Stanford Univ., CA (United States). Dept. of Operations Research Technische Univ., Vienna (Austria). Inst. fuer Energiewirtschaft)

    1992-12-01

    For many practical problems, solutions obtained from deterministic models are unsatisfactory because they fail to hedge against certain contingencies that may occur in the future. Stochastic models address this shortcoming, but up to recently seemed to be intractable due to their size. Recent advances both in solution algorithms and in computer technology now allow us to solve important and general classes of practical stochastic problems. We show how large-scale stochastic linear programs can be efficiently solved by combining classical decomposition and Monte Carlo (importance) sampling techniques. We discuss the methodology for solving two-stage stochastic linear programs with recourse, present numerical results of large problems with numerous stochastic parameters, show how to efficiently implement the methodology on a parallel multi-computer and derive the theory for solving a general class of multi-stage problems with dependency of the stochastic parameters within a stage and between different stages.

  15. Solving Limited Memory Influence Diagrams

    CERN Document Server

    Mauá, Denis Deratani; Zaffalon, Marco

    2011-01-01

    We present a new algorithm for exactly solving decision making problems represented as influence diagrams. We do not require the usual assumptions of no forgetting and regularity; this allows us to solve problems with simultaneous decisions and limited information. The algorithm is empirically shown to outperform a state-of-the-art algorithm on randomly generated problems of up to 150 variables and $10^{64}$ solutions. We show that the problem is NP-hard even if the underlying graph structure of the problem has small treewidth and the variables take on a bounded number of states, but that a fully polynomial time approximation scheme exists for these cases. Moreover, we show that the bound on the number of states is a necessary condition for any efficient approximation scheme.

  16. Reasoning, Problem Solving, and Intelligence.

    Science.gov (United States)

    1980-04-01

    first half of the analogy or because of vocabulary demand in the second half of the analogy. For example, FELINE is to CANINE as CAT is to ? was...the ecological validity of the task as a representative case of real-world problem solving. Investigation of the task’s ecological validity, or at...analogies) measure intellectual functioning of such a basic kind that ecological validity is less important. But if one’s goal is to study the ability to

  17. 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…

  18. 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.…

  19. Assessing Algebraic Solving Ability: A Theoretical Framework

    Science.gov (United States)

    Lian, Lim Hooi; Yew, Wun Thiam

    2012-01-01

    Algebraic solving ability had been discussed by many educators and researchers. There exists no definite definition for algebraic solving ability as it can be viewed from different perspectives. In this paper, the nature of algebraic solving ability in terms of algebraic processes that demonstrate the ability in solving algebraic problem is…

  20. 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.

  1. 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.

  2. Numerical treatment for solving fractional Riccati differential equation

    Directory of Open Access Journals (Sweden)

    M.M. Khader

    2013-04-01

    Full Text Available This paper presents an accurate numerical method for solving fractional Riccati differential equation (FRDE. The proposed method so called fractional Chebyshev finite difference method (FCheb-FDM. In this technique, we approximate FRDE with a finite dimensional problem. The method is based on the combination of the useful properties of Chebyshev polynomials approximation and finite difference method. The Caputo fractional derivative is replaced by a difference quotient and the integral by a finite sum. By this method the given problem is reduced to a problem for solving a system of algebraic equations, and by solving this system, we obtain the solution of FRDE. Special attention is given to study the convergence analysis and estimate an error upper bound of the obtained approximate formula. Illustrative examples are included to demonstrate the validity and applicability of the proposed technique.

  3. INNOVATIVE INSTRUMENTS FOR STIMULATING CREATIVITY AND PROBLEM SOLVING

    Directory of Open Access Journals (Sweden)

    Octav Dumitru DAFINOIU

    2015-08-01

    Full Text Available Abstract The creation of knowledge, the advanced research in strategic directions, the increasing of economic competitiveness and the transfer of knowledge in the economy are priorities of economic policies. They are based on research, development and innovation activities, which although take various shapes, have something in common: they relate to problem solving. Strategies, methods and techniques used in order to find solutions for problems are based on problem solving techniques taken from psychology. This paper, which creates a bridge between the field of economy and that of psychology, proposes innovative tools to stimulate creativity and the problem solving ability. The tools suggested are based on analogy, the fundamental operation of thinking and creative imagination, and can be applied in various business functions.

  4. Combinatorial techniques

    CERN Document Server

    Sane, Sharad S

    2013-01-01

    This is a basic text on combinatorics that deals with all the three aspects of the discipline: tricks, techniques and theory, and attempts to blend them. The book has several distinctive features. Probability and random variables with their interconnections to permutations are discussed. The theme of parity has been specially included and it covers applications ranging from solving the Nim game to the quadratic reciprocity law. Chapters related to geometry include triangulations and Sperner's theorem, classification of regular polytopes, tilings and an introduction to the Eulcidean Ramsey theory. Material on group actions covers Sylow theory, automorphism groups and a classification of finite subgroups of orthogonal groups. All chapters have a large number of exercises with varying degrees of difficulty, ranging from material suitable for Mathematical Olympiads to research.

  5. Graphical representation of the process of solving problems in statics

    Science.gov (United States)

    Lopez, Carlos

    2011-03-01

    It is presented a method of construction to a graphical representation technique of knowledge called Conceptual Chains. Especially, this tool has been focused to the representation of processes and applied to solving problems in physics, mathematics and engineering. The method is described in ten steps and is illustrated with its development in a particular topic of statics. Various possible didactic applications of this technique are showed.

  6. Some Implicit Methods for Solving Harmonic Variational Inequalities

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2016-08-01

    Full Text Available In this paper, we use the auxiliary principle technique to suggest an implicit method for solving the harmonic variational inequalities. It is shown that the convergence of the proposed method only needs pseudo monotonicity of the operator, which is a weaker condition than monotonicity.

  7. Another Approach to Solving Problems in Rotational Statics.

    Science.gov (United States)

    Fineman, Morton A.; Burnett, Carl, Jr.

    1985-01-01

    Presents a technique which aids students in solving static problems involving three or more torques about a given axis. The method is longer and equivalent to the standard method, but students experience success with this new way to treat the more complicated equilibrium problems. (DH)

  8. A Unified Approach for Solving Nonlinear Regular Perturbation Problems

    Science.gov (United States)

    Khuri, S. A.

    2008-01-01

    This article describes a simple alternative unified method of solving nonlinear regular perturbation problems. The procedure is based upon the manipulation of Taylor's approximation for the expansion of the nonlinear term in the perturbed equation. An essential feature of this technique is the relative simplicity used and the associated unified…

  9. A Lagrangean Relaxtion Based Algorithm for Solving Set Partitioning Problems

    NARCIS (Netherlands)

    van Krieken, M.G.C.; Fleuren, H.A.; Peeters, M.J.P.

    2004-01-01

    In this paper we discuss a solver that is developed to solve set partitioning problems.The methods used include problem reduction techniques, lagrangean relaxation and primal and dual heuristics.The optimal solution is found using a branch and bound approach.In this paper we discuss these

  10. The Domino Effect: Problem Solving with Common Table Games.

    Science.gov (United States)

    Reimer, Wilbert

    1989-01-01

    Domino games are used to illustrate problem-solving techniques in a college principles-of-mathematics course. Students develop tables and use Pascal's triangle to find the total number of pips and the sum of numbers on the pieces. (DC)

  11. Parallel SAT Solving using Bit-level Operations

    NARCIS (Netherlands)

    Heule, M.J.H.; Van Maaren, H.

    2008-01-01

    We show how to exploit the 32/64 bit architecture of modern computers to accelerate some of the algorithms used in satisfiability solving by modifying assignments to variables in parallel on a single processor. Techniques such as random sampling demonstrate that while using bit vectors instead of Bo

  12. Solving Generalised Riccati Differential Equations by Homotopy Analysis Method

    Directory of Open Access Journals (Sweden)

    J. Vahidi

    2013-07-01

    Full Text Available In this paper, the quadratic Riccati differential equation is solved by means of an analytic technique, namely the homotopy analysis method (HAM. Comparisons are made between Adomian’s decomposition method (ADM and the exact solution and the homotopy analysis method. The results reveal that the proposed method is very effective and simple.

  13. The Domino Effect: Problem Solving with Common Table Games.

    Science.gov (United States)

    Reimer, Wilbert

    1989-01-01

    Domino games are used to illustrate problem-solving techniques in a college principles-of-mathematics course. Students develop tables and use Pascal's triangle to find the total number of pips and the sum of numbers on the pieces. (DC)

  14. "We Definitely Wouldn't Be Able to Solve It All by Ourselves, but Together…": Group Synergy in Tertiary Students' Problem-Solving Practices

    Science.gov (United States)

    Clark, Kathleen; James, Alex; Montelle, Clemency

    2014-01-01

    The ability to address and solve problems in minimally familiar contexts is the core business of research mathematicians. Recent studies have identified key traits and techniques that individuals exhibit while problem solving, and revealed strategies and behaviours that are frequently invoked in the process. We studied advanced calculus students…

  15. "We Definitely Wouldn't Be Able to Solve It All by Ourselves, but Together…": Group Synergy in Tertiary Students' Problem-Solving Practices

    Science.gov (United States)

    Clark, Kathleen; James, Alex; Montelle, Clemency

    2014-01-01

    The ability to address and solve problems in minimally familiar contexts is the core business of research mathematicians. Recent studies have identified key traits and techniques that individuals exhibit while problem solving, and revealed strategies and behaviours that are frequently invoked in the process. We studied advanced calculus students…

  16. Solving Partial Differential Equations on Overlapping Grids

    Energy Technology Data Exchange (ETDEWEB)

    Henshaw, W D

    2008-09-22

    We discuss the solution of partial differential equations (PDEs) on overlapping grids. This is a powerful technique for efficiently solving problems in complex, possibly moving, geometry. An overlapping grid consists of a set of structured grids that overlap and cover the computational domain. By allowing the grids to overlap, grids for complex geometries can be more easily constructed. The overlapping grid approach can also be used to remove coordinate singularities by, for example, covering a sphere with two or more patches. We describe the application of the overlapping grid approach to a variety of different problems. These include the solution of incompressible fluid flows with moving and deforming geometry, the solution of high-speed compressible reactive flow with rigid bodies using adaptive mesh refinement (AMR), and the solution of the time-domain Maxwell's equations of electromagnetism.

  17. Solving Crystal Structures from Powder Diffraction Data

    DEFF Research Database (Denmark)

    Christensen, A. Nørlund; Lehmann, M. S.; Nielsen, Mogens

    1985-01-01

    High resolution powder data from both neutron and X-ray (synchrotron) sources have been used to estimate the possibility of direct structure determination from powder data. Two known structures were resolved by direct methods with neutron and X-ray data. With synchrotron X-ray data, the measured...... range of data was insufficient for a structure analysis, but the R-factor calculations showed the intensities extracted from the profile data to be of acceptable quality. The results were used to estimate the largest structure that might be solved using routine techniques. It was found that the limit...... would be near twenty atoms in the asymmetric part of a centro-symmetric structure....

  18. L'impact des développements scientifiques sur la résolution des problèmes techniques posés par la nouvelle conjoncture dans l'exploration et la production du pétrole Impact of Scientific Developments on the Solving of Technical Problems Raised by the New Economic Situation in Oil Exploration and Production

    Directory of Open Access Journals (Sweden)

    Tissot B.

    2006-11-01

    Full Text Available Dans les circonstances difficiles que traverse l'exploration et la production du pétrole, le savoir-faire technologique, associé à la maîtrise des coûts, seront pour l'industrie pétrolière et parapétrolière des atouts essentiels. On envisage ici l'impact prévisible des développements scientifiques sur la résolution des problèmes techniques dans l'exploration et la production. Les principales disciplines scientifiques concernées (géologie, géophysique, géochimie, mécanique des roches et des sols, mécanique des fluides, physicochimie des interfaces ainsi que trois techniques de base (modélisation, systèmes experts, matériaux nouveaux sont examinées dans ce sens. En particulier,la modélisation numérique voit son importance croître de manière spectaculaire : elle couvre désormais des domaines nouveaux, comme les Sciences de la Terre, et continue à s'enrichir de développements importants, même dans les secteurs où on l'utilise depuis 20 ans comme la production. Ces évolutions s'accompagneront nécessairement d'ajustements dans la formation des hommes et le fonctionnement des organisations; en particulier un espace nouveau pourrait se dégager pour de petites entreprises de conseil et de service plus riches en matière grise qu'en investissements lourds. In the difficult circumstances now confronting oil exploration and production, technical know-how combined with cost control will be essential assets for the petroleum and petroleum equipment and service industries. This article considers the foreseeable impact of scientific developments on the solving of technical problems in exploration and production. The principal scientific disciplines involved (geology, geophysics, geochemistry, rock and soil mechanics, fluid mechanics, interface physicochemistry as well as three basic techniques (modeling, expert systems, new materials are examined within this context. In particular, numerical modeling is increasing in

  19. 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

  20. Brainstorming: Thinking - Problem Solving Strategy

    Directory of Open Access Journals (Sweden)

    Ms. Agnes Monica .V

    2017-03-01

    Full Text Available Brainstorming is a popular tool that helps you generate creative answers to a problem. It is mainly useful when you want to break out of stale, established patterns of thinking, so that you can develop new ways of looking at things. The aforementioned also helps you overcome many of the concerns that can make collection problemsolving a sterile and substandard process. Though group brainstorming is often more effective at generating ideas than normal group problem-solving, study after study has revealed that when individuals brainstorm on their own, they come up with more ideas and often better quality ideas than groups of people who brainstorm together

  1. Algorithms in Solving Polynomial Inequalities

    Directory of Open Access Journals (Sweden)

    Christopher M. Cordero

    2015-11-01

    Full Text Available A new method to solve the solution set of polynomial inequalities was conducted. When −1 −2 >0 ℎ 1,2∈ ℝ 10 if n is even. Then, the solution set is ∈ ℝ ∈ −∞,1 ∪ ,+∞ ∪ ,+1 : }. Thus, when −1−2…−≥0, the solution is ∈ ℝ ∈−∞, 1∪ ,+∞∪, +1: }. If is odd, then the solution set is ∈ ℝ ∈ ,+∞ ∪ ,+1 : }. Thus, when −1 −2…−≥0, the solution set is ∈ ℝ ∈ ,+∞∪, +1: }. Let −1−2…−<0 if n is even. Then, the solution set is ∈ ℝ ∈ ,+1 ∶ }. Thus, when −1 −2…−≤0, then the solution set is ∈ ℝ ∈, +1: }. If is an odd, then the solution set is ∈ ℝ ∈ −∞,1 ∪ ,+1 : }. Thus, when −1 −2 … − ≤0, the solution set is ∈ ℝ ∈ −∞,1 ∪ ,+1 : }. This research provides a novel method in solving the solution set of polynomial inequalities, in addition to other existing methods.

  2. A Heuristic Framework to Solve a General Delivery Problem

    Science.gov (United States)

    Lian, Lian; Castelain, Emmanuel

    2010-06-01

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

  3. Solving the Stokes problem on a massively parallel computer

    DEFF Research Database (Denmark)

    Axelsson, Owe; Barker, Vincent A.; Neytcheva, Maya

    2001-01-01

    We describe a numerical procedure for solving the stationary two‐dimensional Stokes problem based on piecewise linear finite element approximations for both velocity and pressure, a regularization technique for stability, and a defect‐correction technique for improving accuracy. Eliminating...... boundary value problem for each velocity component, are solved by the conjugate gradient method with a preconditioning based on the algebraic multi‐level iteration (AMLI) technique. The velocity is found from the computed pressure. The method is optimal in the sense that the computational work...... is proportional to the number of unknowns. Further, it is designed to exploit a massively parallel computer with distributed memory architecture. Numerical experiments on a Cray T3E computer illustrate the parallel performance of the method....

  4. Solving the Travelling Salesman Problem Using the Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Zuzana Čičková

    2011-12-01

    Full Text Available In this article, we study a possibility of solving the well-known Travelling Salesman Problem (TSP, which ranges among NP-hard problems, and offer a theoretical overview of some methods used for solving this problem. We discuss the Ant Colony Optimization (ACO, which belongs to the group of evolutionary techniques and presents the approach used in the application of ACO to the TSP. We study the impact of some control parameters by implementing this algorithm. The quality of the solution is compared with the optimal solution.

  5. Numerical methods for solving terminal optimal control problems

    Science.gov (United States)

    Gornov, A. Yu.; Tyatyushkin, A. I.; Finkelstein, E. A.

    2016-02-01

    Numerical methods for solving optimal control problems with equality constraints at the right end of the trajectory are discussed. Algorithms for optimal control search are proposed that are based on the multimethod technique for finding an approximate solution of prescribed accuracy that satisfies terminal conditions. High accuracy is achieved by applying a second-order method analogous to Newton's method or Bellman's quasilinearization method. In the solution of problems with direct control constraints, the variation of the control is computed using a finite-dimensional approximation of an auxiliary problem, which is solved by applying linear programming methods.

  6. A new algorithm for solving linear programming problems

    Directory of Open Access Journals (Sweden)

    Andrés Leonardo Ramírez Leal

    2012-08-01

    Full Text Available Linear programming (LP is one of the most widely-applied techniques in operations research. Many methods have been developed and several others are being proposed for solving LP problems, including the famous simplex method and interior point algorithms. This study was aimed at introducing a new method for solving LP problems. The proposed algorithm starts from an interior point and then carries out orthogonal projections using parametric straight lines to move between the interior and polyhedron frontier defining the feasible region until reaching the extreme optimal point.

  7. Solving Excess Water Production Problems in Productive Formation

    Directory of Open Access Journals (Sweden)

    Kozyrev Ilya

    2016-01-01

    Full Text Available One of the important developments of the Russian Federation national economy is a petroleum resource. Water shut off techniques are used in the oilfields to avoid the massive water production. We describe a technology for solving excess water production problems focusing on the new gel-based fluid which can be effectively applied for water shutoff. We study the effect of the gel-based fluid solution experimentally to show the feasibility of its treatment the in the near wellbore region to solve the excess water production problem.

  8. Efficient Method to Approximately Solve Retrial Systems with Impatience

    Directory of Open Access Journals (Sweden)

    Jose Manuel Gimenez-Guzman

    2012-01-01

    Full Text Available We present a novel technique to solve multiserver retrial systems with impatience. Unfortunately these systems do not present an exact analytic solution, so it is mandatory to resort to approximate techniques. This novel technique does not rely on the numerical solution of the steady-state Kolmogorov equations of the Continuous Time Markov Chain as it is common for this kind of systems but it considers the system in its Markov Decision Process setting. This technique, known as value extrapolation, truncates the infinite state space using a polynomial extrapolation method to approach the states outside the truncated state space. A numerical evaluation is carried out to evaluate this technique and to compare its performance with previous techniques. The obtained results show that value extrapolation greatly outperforms the previous approaches appeared in the literature not only in terms of accuracy but also in terms of computational cost.

  9. Heisenberg Honeycombs Solve Veneziano Puzzle

    CERN Document Server

    Kholodenko, A L

    2006-01-01

    In this paper we reformulate some results obtained by Heisenberg into modern mathematical language of honeycombs. This language was developed in connection with complete solution of the Horn conjecture problem. Such a reformulation is done with the purpose of posing and solving the following problem. Is by analysing the (spectroscopic) experimental data it possible to restore the underlying microscopic physical model generating these data? Development of Heisenberg's ideas happens to be the most useful for this purpose. Solution is facilitated by our earlier developed string-theoretic formalism. In this paper only qualitative arguments are presented (with few exceptions). These arguments provide enough evidence that the underelying microscopic model compatible with Veneziano-type amplitudes is the standard (i.e. non supersymmetric!) QCD. In addition, usefulness of the formalism is illustrated on numerous examples such as physically motivated solution of the saturation conjecture, derivation of the Yang-Baxter...

  10. Solving the structure of metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Proffen, Thomas E [Los Alamos National Laboratory; White, Claire E [Los Alamos National Laboratory; Provis, John L [UNIV. OF MELBOURNE; Riley, Daniel P [UNIV. OF MELBOURNE; Van Deventer, Jannie S J [UNIV. OF MELBOURNE

    2009-01-01

    Metakaolin has been used extensively as a cement additive and paint extender, and recently as a geopolymer precursor. This disordered layered aluminosilicate is formed via the dehydroxylation of kaolinite. However, an accurate representation of its atomic structure has bever before been presented. Here, a novel synergy between total scattering and density functional modeling is presented to solve the structure of metakaolin. The metastable structure is elucidated by iterating between least-squares real-space refinement using neutron pair distribution function data, and geometry optimization using density functional modeling. The resulting structural representation is both energetically feasible and in excellent agreement with experimental data. This accurate structure of metakaolin provides new insight into the local environment of the aluminum atoms, with evidence of the existence of tri-coordinated aluminum. By the availability of this detailed atomic description, there exists the opportunity to tailor chemical and mechanical processes involving metakaolin at the atomic level to obtain optimal performance at the macro-scale.

  11. Solving rational expectations models using Excel

    DEFF Research Database (Denmark)

    Strulik, Holger

    2004-01-01

    Problems of discrete time optimal control can be solved using backward iteration and Microsoft Excel. The author explains the method in general and shows how the basic models of neoclassical growth and real business cycles are solved......Problems of discrete time optimal control can be solved using backward iteration and Microsoft Excel. The author explains the method in general and shows how the basic models of neoclassical growth and real business cycles are solved...

  12. Problem Solving Appraisal of Delinquent Adolescents.

    Science.gov (United States)

    Perez, Ruperto M.; And Others

    The study investigated the following: (1) the relationship of problem solving appraisal to narcissistic vulnerability, locus of control, and depression; (2) the differences in problem solving appraisal, locus of control, and depression in first-time and repeat offenders; and (3) the prediction of problem solving appraisal by narcissistic…

  13. Perspectives on Problem Solving and Instruction

    Science.gov (United States)

    van Merrienboer, Jeroen J. G.

    2013-01-01

    Most educators claim that problem solving is important, but they take very different perspective on it and there is little agreement on how it should be taught. This article aims to sort out the different perspectives and discusses problem solving as a goal, a method, and a skill. As a goal, problem solving should not be limited to well-structured…

  14. LEGO Robotics: An Authentic Problem Solving Tool?

    Science.gov (United States)

    Castledine, Alanah-Rei; Chalmers, Chris

    2011-01-01

    With the current curriculum focus on correlating classroom problem solving lessons to real-world contexts, are LEGO robotics an effective problem solving tool? This present study was designed to investigate this question and to ascertain what problem solving strategies primary students engaged with when working with LEGO robotics and whether the…

  15. Collis-Romberg Mathematical Problem Solving Profiles.

    Science.gov (United States)

    Collis, K. F.; Romberg, T. A.

    Problem solving has become a focus of mathematics programs in Australia in recent years, necessitating the assessment of students' problem-solving abilities. This manual provides a problem-solving assessment and teaching resource package containing four elements: (1) profiles assessment items; (2) profiles diagnostic forms for recording individual…

  16. Developing Creativity through Collaborative Problem Solving

    Science.gov (United States)

    Albert, Lillie R.; Kim, Rina

    2013-01-01

    This paper discusses an alternative approach for developing problem solving experiences for students. The major argument is that students can develop their creativity by engaging in collaborative problem solving activities in which they apply a variety of mathematical methods creatively to solve problems. The argument is supported by: considering…

  17. ON ALGEBRICO-DIFFERENTIAL EQUATIONS-SOLVING

    Institute of Scientific and Technical Information of China (English)

    WU Wenjun(Wu Wen-tsun)

    2004-01-01

    The char-set method of polynomial equations-solving is naturally extended to the differential case which gives rise to an algorithmic method of solving arbitrary systems of algebrico-differential equations. As an illustration of the method, the Devil's Problem of Pommaret is solved in details.

  18. Decision e Informacion en Solucion de Problemas. Publicacion No. 77 (Information and Decision Making in Problem Solving. Publication No. 77).

    Science.gov (United States)

    Rimoldi, Horacio J. A.; And Others

    A technique using information and decision-making theories to evaluate problem solving tactics is presented. In problem solving, the process of solution is evaluated by investigating the questions that the subject doing the problem solving asks. The sequence of questions asked is called a tactic. It is assumed that: (1) tactics are the observable…

  19. Decision e Informacion en Solucion de Problemas. Publicacion No. 77 (Information and Decision Making in Problem Solving. Publication No. 77).

    Science.gov (United States)

    Rimoldi, Horacio J. A.; And Others

    A technique using information and decision-making theories to evaluate problem solving tactics is presented. In problem solving, the process of solution is evaluated by investigating the questions that the subject doing the problem solving asks. The sequence of questions asked is called a tactic. It is assumed that: (1) tactics are the observable…

  20. Feedback Control Method Using Haar Wavelet Operational Matrices for Solving Optimal Control Problems

    OpenAIRE

    Waleeda Swaidan; Amran Hussin

    2013-01-01

    Most of the direct methods solve optimal control problems with nonlinear programming solver. In this paper we propose a novel feedback control method for solving for solving affine control system, with quadratic cost functional, which makes use of only linear systems. This method is a numerical technique, which is based on the combination of Haar wavelet collocation method and successive Generalized Hamilton-Jacobi-Bellman equation. We formulate some new Haar wavelet oper...

  1. A novel computing three-dimensional differential transform method for solving fuzzy partial differential equations

    OpenAIRE

    Farshid Mirzaee; Mohammad Komak Yari

    2016-01-01

    In this paper, we introduce three-dimensional fuzzy differential transform method and we utilize it to solve fuzzy partial differential equations. This technique is a successful method because of reducing such problems to solve a system of algebraic equations; so, the problem can be solved directly. A considerable advantage of this method is to obtain the analytical solutions if the equation has an exact solution that is a polynomial function. Numerical examples are included to demonstrate th...

  2. Requirements Engineering as Creative Problem Solving: A Research Agenda for Idea Finding

    OpenAIRE

    Maiden, N.; Jones, S; Karlsen, I. K.; Neill, R.; Zachos, K.; Milne, A.

    2010-01-01

    This vision paper frames requirements engineering as a creative problem solving process. Its purpose is to enable requirements researchers and practitioners to recruit relevant theories, models, techniques and tools from creative problem solving to understand and support requirements processes more effectively. It uses 4 drivers to motivate the case for requirements engineering as a creative problem solving process. It then maps established requirements activities onto one of the longest-esta...

  3. Peningkatan Pemahaman Manajemen Waktu Melalui Bimbingan Kelompok Dengan Teknik Problem Solving pada Siswa

    Directory of Open Access Journals (Sweden)

    Diana Dwi Nurhidayati

    2016-06-01

    Full Text Available The purpose of this study is to determine the increase of time management understanding through group guidance with problem solving techniques. This research is a classroom action research with cross sectional type. The subjects of research were ten students of class VII A SMP Muhammadiyah 4 Yogyakarta taken by purposive sampling technique. Data collection instrument used was in the form of a questionnaire of time management understanding. Data analysis technique to test the effectiveness of group guidance was problem solving technique which is to improve the understanding of time management of SMP students using the Wilcoxon test. The results of data analysis shows a mean of time management understanding before the action of problem solving techniques was 55.30 and the average after problem solving techniques given was 78.60. Wilcoxon test results shows p = 0.005 so that we can conclude that there is an increase of time management understanding of SMP students after using group guidance with problem solving techniques. The results of this study can be useful for guidance and counseling teachers as a consideration material in improving the understanding of students’ time management through group guidance services using problem solving techniques.

  4. Decomposition method for solving parabolic equations in finite domains

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper presents a comparison among Adomian decomposition method (ADM), Wavelet-Galerkin method (WGM),the fully explicit (1,7) finite difference technique (FTCS), the fully implicit (7,1) finite difference method (BTCS), (7,7)Crank-Nicholson type finite difference formula (C-N), the fully explicit method (1,13) and 9-point finite difference method, for solving parabolic differential equations with arbitrary boundary conditions and based on weak form functionals in finite domains.The problem is solved rapidly, easily and elegantly by ADM. The numerical results on a 2D transient heat conducting problem and 3D diffusion problem are used to validate the proposed ADM as an effective numerical method for solving finite domain parabolic equations. The numerical results showed that our present method is less time consuming and is easier to use than other methods. In addition, we prove the convergence of this method when it is applied to the nonlinear parabolic equation.

  5. An adaptive genetic algorithm for solving bilevel linear programming problem

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bilevel linear programming, which consists of the objective functions of the upper level and lower level, is a useful tool for modeling decentralized decision problems.Various methods are proposed for solving this problem. Of all the algorithms, the genetic algorithm is an alternative to conventional approaches to find the solution of the bilevel linear programming. In this paper, we describe an adaptive genetic algorithm for solving the bilevel linear programming problem to overcome the difficulty of determining the probabilities of crossover and mutation. In addition, some techniques are adopted not only to deal with the difficulty that most of the chromosomes may be infeasible in solving constrained optimization problem with genetic algorithm but also to improve the efficiency of the algorithm. The performance of this proposed algorithm is illustrated by the examples from references.

  6. 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.

  7. Domain decomposition methods for solving an image problem

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, W.K.; Tong, C.S. [Hong Kong Baptist College (Hong Kong)

    1994-12-31

    The domain decomposition method is a technique to break up a problem so that ensuing sub-problems can be solved on a parallel computer. In order to improve the convergence rate of the capacitance systems, pre-conditioned conjugate gradient methods are commonly used. In the last decade, most of the efficient preconditioners are based on elliptic partial differential equations which are particularly useful for solving elliptic partial differential equations. In this paper, the authors apply the so called covering preconditioner, which is based on the information of the operator under investigation. Therefore, it is good for various kinds of applications, specifically, they shall apply the preconditioned domain decomposition method for solving an image restoration problem. The image restoration problem is to extract an original image which has been degraded by a known convolution process and additive Gaussian noise.

  8. Problem-solving Model for Managing Stress and Anxiety

    Directory of Open Access Journals (Sweden)

    Taghi Abutalebi Ahmadi

    2013-07-01

    Full Text Available The purpose of this study is to take a look at problem-solving model for managing stress and anxiety. If each of us as a human being has an organized method for solving the different problems of our life, at that time we can get along with stress and anxiety easily. The capability of problem solving makes it possible for that person a to distinguish emotions in himself and others b to understand how excitement affects behavior c to be able to show different reactions to different emotions. If we don’t deal with emotional states such as grief, anger or anxiety properly, theses emotions will have negative effects on the physical and mental health of the person. Problem solving teaching is a treatment method by which the person learns to utilize effective cognitive skills to get along with inter-personal and problematic situations. In this study, we would like to emphasize the importance of the problem-solving teaching, and learn about its varieties and principal and implementation techniques, so that we can use it to manage our internal and environmental stressors. Among the various models, I will mention the easy and helpful five-step problem solving approach of Dixon and Glover (1984, as cited Yari (2009 as an example including describing the problem, stating the problem in precise and clear terms, selecting guidelines for solving the problems and prioritizing them, implementing the guidelines characterized at the previous stage, finally evaluating. At this stage, we will consider what we have gained vis a vis what we had hoped to gain.

  9. Developing Problem-Solving Skills of Students Taking Introductory Physics via Web-Based Tutorials

    Science.gov (United States)

    Singh, Chandralekha; Haileselassie, Daniel

    2010-01-01

    Science teaching and learning can be made both engaging and student-centered using pedagogical, computer-based learning tools. We have developed self-paced interactive problem-solving tutorials for introductory physics. These tutorials can provide guidance and support for a variety of problem-solving techniques, as well as opportunities for…

  10. Developing Problem-Solving Skills of Students Taking Introductory Physics via Web-Based Tutorials

    Science.gov (United States)

    Singh, Chandralekha; Haileselassie, Daniel

    2010-01-01

    Science teaching and learning can be made both engaging and student-centered using pedagogical, computer-based learning tools. We have developed self-paced interactive problem-solving tutorials for introductory physics. These tutorials can provide guidance and support for a variety of problem-solving techniques, as well as opportunities for…

  11. USING SYSTEM SIMULATION METHOD AND CADTECHNIQUE TO SOLVE THE MINING ENGINEERING RELIABILITY IN SURFACE MINES

    Institute of Scientific and Technical Information of China (English)

    才庆祥; 彭世济; 张达贤

    1996-01-01

    Subjected to various stochastic factors, surface mining engineering reliability is difficult to solve by using general reliability mathematical method. The concept of reliability measurement is introduced; And the authors have combined system simulation method with CAD technique and developed an interactive color character graphic design system for evaluating and solving the mining engineering reliability in surface mines under the given constraints.

  12. Review on solving the forward problem in EEG source analysis

    Directory of Open Access Journals (Sweden)

    Vergult Anneleen

    2007-11-01

    methods are required to solve these sparse linear systems. The following iterative methods are discussed: successive over-relaxation, conjugate gradients method and algebraic multigrid method. Conclusion Solving the forward problem has been well documented in the past decades. In the past simplified spherical head models are used, whereas nowadays a combination of imaging modalities are used to accurately describe the geometry of the head model. Efforts have been done on realistically describing the shape of the head model, as well as the heterogenity of the tissue types and realistically determining the conductivity. However, the determination and validation of the in vivo conductivity values is still an important topic in this field. In addition, more studies have to be done on the influence of all the parameters of the head model and of the numerical techniques on the solution of the forward problem.

  13. Solving equations through particle dynamics

    Science.gov (United States)

    Edvardsson, S.; Neuman, M.; Edström, P.; Olin, H.

    2015-12-01

    The present work evaluates a recently developed particle method (DFPM). The basic idea behind this method is to utilize a Newtonian system of interacting particles that through dissipation solves mathematical problems. We find that this second order dynamical system results in an algorithm that is among the best methods known. The present work studies large systems of linear equations. Of special interest is the wide eigenvalue spectrum. This case is common as the discretization of the continuous problem becomes dense. The convergence rate of DFPM is shown to be in parity with that of the conjugate gradient method, both analytically and through numerical examples. However, an advantage with DFPM is that it is cheaper per iteration. Another advantage is that it is not restricted to symmetric matrices only, as is the case for the conjugate gradient method. The convergence properties of DFPM are shown to be superior to the closely related approach utilizing only a first order dynamical system, and also to several other iterative methods in numerical linear algebra. The performance properties are understood and optimized by taking advantage of critically damped oscillators in classical mechanics. Just as in the case of the conjugate gradient method, a limitation is that all eigenvalues (spring constants) are required to be of the same sign. DFPM has no other limitation such as matrix structure or a spectral radius as is common among iterative methods. Examples are provided to test the particle algorithm's merits and also various performance comparisons with existent numerical algorithms are provided.

  14. Community-powered problem solving.

    Science.gov (United States)

    Gouillart, Francis; Billings, Douglas

    2013-04-01

    Traditionally, companies have managed their constituencies with specific processes: marketing to customers, procuring from vendors, developing HR policies for employees, and so on. The problem is, such processes focus on repeatability and compliance, so they can lead to stagnation. Inviting your constituencies to collectively help you solve problems and exploit opportunities--"co-creation"--is a better approach. It allows you to continually tap the skills and insights of huge numbers of stakeholders and develop new ways to produce value for all. The idea is to provide stakeholders with platforms (physical and digital forums) on which they can interact, get them to start exploring new experiences and connections, and let the system grow organically. A co-creation initiative by a unit of Becton, Dickinson and Company demonstrates how this works. A global leader in syringes, BD set out to deepen its ties with hospital customers and help them reduce the incidence of infections from unsafe injection and syringe disposal practices. The effort began with a cross-functional internal team, brought in the hospital procurement and supply managers BD had relationships with, and then reached out to hospitals' infection-prevention and occupational health leaders. Eventually product designers, nurses, sustainability staffers, and even hospital CFOs were using the platform, contributing data that generated new best practices and reduced infections.

  15. Bit Preservation: A Solved Problem?

    Directory of Open Access Journals (Sweden)

    David S. H. Rosenthal

    2010-07-01

    Full Text Available For years, discussions of digital preservation have routinely featured comments such as “bit preservation is a solved problem; the real issues are ...”. Indeed, current digital storage technologies are not just astoundingly cheap and capacious, they are astonishingly reliable. Unfortunately, these attributes drive a kind of “Parkinson’s Law” of storage, in which demands continually push beyond the capabilities of systems implementable at an affordable price. This paper is in four parts:Claims, reviewing a typical claim of storage system reliability, showing that it provides no useful information for bit preservation purposes.Theory, proposing “bit half-life” as an initial, if inadequate, measure of bit preservation performance, expressing bit preservation requirements in terms of it, and showing that the requirements being placed on bit preservation systems are so onerous that the experiments required to prove that a solution exists are not feasible.Practice, reviewing recent research into how well actual storage systems preserve bits, showing that they fail to meet the requirements by many orders of magnitude.Policy, suggesting ways of dealing with this unfortunate situation.

  16. Podejście PDCA Problem Solving w rozwiązywaniu problemów organizacji

    OpenAIRE

    Obora, Hubert

    2010-01-01

    The aim of this paper is to present one of newest team oriented problem solving method – PDCA Problem Solving. The author introduces the origin and essence of the method. He also describes the various stages involved In PDCA Problem Solving and presents examples of auxiliary methods and techniques. The last section of the paper is an attempt at evaluating the application PDCA Problem Solving as a method of continuous improvement.

  17. Comparison of Algebraic Multigrid Preconditioners for Solving Helmholtz Equations

    Directory of Open Access Journals (Sweden)

    Dandan Chen

    2012-01-01

    Full Text Available An algebraic multigrid (AMG with aggregation technique to coarsen is applied to construct a better preconditioner for solving Helmholtz equations in this paper. The solution process consists of constructing the preconditioner by AMG and solving the preconditioned Helmholtz problems by Krylov subspace methods. In the setup process of AMG, we employ the double pairwise aggregation (DPA scheme firstly proposed by Y. Notay (2006 as the coarsening method. We compare it with the smoothed aggregation algebraic multigrid and meanwhile show shifted Laplacian preconditioners. According to numerical results, we find that DPA algorithm is a good choice in AMG for Helmholtz equations in reducing time and memory. Spectral estimation of system preconditioned by the three methods and the influence of second-order and fourth-order accurate discretizations on the three techniques are also considered.

  18. IDEAL Problem Solving dalam Pembelajaran Matematika

    Directory of Open Access Journals (Sweden)

    Eny Susiana

    2012-01-01

    Full Text Available Most educators agree that problem solving is among the most meaningful and importantkinds of learning and thingking. That is, the central focus of learning and instructionshould be learning to solve problems. There are several warrants supporting that claims.They are authenticity, relevance, problem solving engages deeper learning angtherefore enhances meaning making, and constructed to represent problems (problemsolving is more meaningful. It is the reason why we must provide teaching and learningto make student’s problem solving skill in progress. There are many informationprocessingmodels of problem solving, such as simplified model of the problem-solvingprocess by Gicks, Polya’s problem solving process etc. One of them is IDEAL problemsolving. Each letter of IDEAL is stand for an aspect of thinking that is important forproblem solving. IDEAL is identify problem, Define Goal, Explore possible strategies,Anticipate outcme and Act, and Look back and learn. Using peer interaction andquestion prompt in small group in IDEAL problem solving teaching and Learning canimprove problem solving skill.Kata kunci: IDEAL Problem Solving, Interaksi Sebaya, Pertanyaan Penuntun, KelompokKecil.

  19. Monte Carlo method for solving a parabolic problem

    Directory of Open Access Journals (Sweden)

    Tian Yi

    2016-01-01

    Full Text Available In this paper, we present a numerical method based on random sampling for a parabolic problem. This method combines use of the Crank-Nicolson method and Monte Carlo method. In the numerical algorithm, we first discretize governing equations by Crank-Nicolson method, and obtain a large sparse system of linear algebraic equations, then use Monte Carlo method to solve the linear algebraic equations. To illustrate the usefulness of this technique, we apply it to some test problems.

  20. Projective geometry solved problems and theory review

    CERN Document Server

    Fortuna, Elisabetta; Pardini, Rita

    2016-01-01

    This book starts with a concise but rigorous overview of the basic notions of projective geometry, using straightforward and modern language. The goal is not only to establish the notation and terminology used, but also to offer the reader a quick survey of the subject matter. In the second part, the book presents more than 200 solved problems, for many of which several alternative solutions are provided. The level of difficulty of the exercises varies considerably: they range from computations to harder problems of a more theoretical nature, up to some actual complements of the theory. The structure of the text allows the reader to use the solutions of the exercises both to master the basic notions and techniques and to further their knowledge of the subject, thus learning some classical results not covered in the first part of the book. The book addresses the needs of undergraduate and graduate students in the theoretical and applied sciences, and will especially benefit those readers with a solid grasp of ...

  1. IDEAL Problem Solving dalam Pembelajaran Matematika

    OpenAIRE

    Eny Susiana

    2012-01-01

    Most educators agree that problem solving is among the most meaningful and importantkinds of learning and thingking. That is, the central focus of learning and instructionshould be learning to solve problems. There are several warrants supporting that claims.They are authenticity, relevance, problem solving engages deeper learning angtherefore enhances meaning making, and constructed to represent problems (problemsolving) is more meaningful. It is the reason why we must provide teaching and l...

  2. Geometric constraint solving with geometric transformation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper proposes two algorithms for solving geometric constraint systems. The first algorithm is for constrained systems without loops and has linear complexity. The second algorithm can solve constraint systems with loops. The latter algorithm is of quadratic complexity and is complete for constraint problems about simple polygons. The key to it is to combine the idea of graph based methods for geometric constraint solving and geometric transformations coming from rule-based methods.

  3. Solving global optimization problems on GPU cluster

    Science.gov (United States)

    Barkalov, Konstantin; Gergel, Victor; Lebedev, Ilya

    2016-06-01

    The paper contains the results of investigation of a parallel global optimization algorithm combined with a dimension reduction scheme. This allows solving multidimensional problems by means of reducing to data-independent subproblems with smaller dimension solved in parallel. The new element implemented in the research consists in using several graphic accelerators at different computing nodes. The paper also includes results of solving problems of well-known multiextremal test class GKLS on Lobachevsky supercomputer using tens of thousands of GPU cores.

  4. Mobile serious games for collaborative problem solving.

    Science.gov (United States)

    Sanchez, Jaime; Mendoza, Claudia; Salinas, Alvaro

    2009-01-01

    This paper presents the results obtained from the implementation of a series of learning activities based on mobile serious games (MSG) for the development of problem-solving and collaborative skills in Chilean 8th grade students. Three MSGs were developed and played by teams of four students, who had to solve the problems posed by the game collaboratively. The data shows that the experimental group had a higher perception of their own skills of collaboration and of the plan execution dimension of problem solving than the control group, providing empirical evidence regarding the contribution of MSGs to the development of collaborative problem-solving skills.

  5. 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)

  6. Does social problem solving differ from other types of problem solving during the adult years?

    Science.gov (United States)

    Heidrich, S M; Denney, N W

    1994-01-01

    One hundred thirteen individuals, ages 18-81, were presented with a test of social problem solving, a test of practical problem solving, the Twenty Questions task (a test of traditional problem solving), the Wechsler Adult Intelligence Scale--Revised Vocabulary subtest (a measure of crystallized intelligence), and Raven's Progressive Matrices (a measure of fluid intelligence). The effects of age, sex, education, and intellectual abilities on problem-solving performance were examined. Social problem solving was positively related to higher education and higher Vocabulary scores, but it was not related to age. Social problem solving and practical problem solving were significantly related to each other and to scores on the Vocabulary subtest, whereas traditional problem solving was significantly related to scores on Raven's Progressive Matrices. These results suggest that different types of problem solving are differentially related to other intellectual abilities and to age.

  7. Solving for Micro- and Macro- Scale Electrostatic Configurations Using the Robin Hood Algorithm

    CERN Document Server

    Formaggio, J A; Corona, T J; Stefancic, H; Abraham, H; Gluck, F

    2011-01-01

    We present a novel technique by which highly-segmented electrostatic configurations can be solved. The Robin Hood method is a matrix-inversion algorithm optimized for solving high density boundary element method (BEM) problems. We illustrate the capabilities of this solver by studying two distinct geometry scales: (a) the electrostatic potential of a large volume beta-detector and (b) the field enhancement present at surface of electrode nano-structures. Geometries with elements numbering in the O(10^5) are easily modeled and solved without loss of accuracy. The technique has recently been expanded so as to include dielectrics and magnetic materials.

  8. Distance Measurement Solves Astrophysical Mysteries

    Science.gov (United States)

    2003-08-01

    Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of

  9. A New Method for Solving Supervised Data Classification Problems

    Directory of Open Access Journals (Sweden)

    Parvaneh Shabanzadeh

    2014-01-01

    Full Text Available Supervised data classification is one of the techniques used to extract nontrivial information from data. Classification is a widely used technique in various fields, including data mining, industry, medicine, science, and law. This paper considers a new algorithm for supervised data classification problems associated with the cluster analysis. The mathematical formulations for this algorithm are based on nonsmooth, nonconvex optimization. A new algorithm for solving this optimization problem is utilized. The new algorithm uses a derivative-free technique, with robustness and efficiency. To improve classification performance and efficiency in generating classification model, a new feature selection algorithm based on techniques of convex programming is suggested. Proposed methods are tested on real-world datasets. Results of numerical experiments have been presented which demonstrate the effectiveness of the proposed algorithms.

  10. Concept mapping instrumental support for problem solving

    NARCIS (Netherlands)

    Stoyanov, Slavi; Kommers, Piet

    2008-01-01

    The main theoretical position of this paper is that it is the explicit problem-solving support in concept mapping software that produces a stronger effect in problem-solving performance than the implicit support afforded by the graphical functionality of concept mapping software. Explicit problem-so

  11. Mathematical Problem Solving through Sequential Process Analysis

    Science.gov (United States)

    Codina, A.; Cañadas, M. C.; Castro, E.

    2015-01-01

    Introduction: The macroscopic perspective is one of the frameworks for research on problem solving in mathematics education. Coming from this perspective, our study addresses the stages of thought in mathematical problem solving, offering an innovative approach because we apply sequential relations and global interrelations between the different…

  12. Measuring Problem Solving Skills in "Portal 2"

    Science.gov (United States)

    Shute, Valerie J.; Wang, Lubin

    2013-01-01

    This paper examines possible improvement to problem solving skills as a function of playing the video game "Portal 2." Stealth assessment is used in the game to evaluate students' problem solving abilities--specifically basic and flexible rule application. The stealth assessment measures will be validated against commonly accepted…

  13. Mathematical problem solving in primary school

    NARCIS (Netherlands)

    Kolovou, A.|info:eu-repo/dai/nl/313715947

    2011-01-01

    A student is engaged in (non-routine) problem solving when there is no clear pathway to the solution. In contrast to routine problems, non-routine ones cannot be solved through the direct application of a standard procedure. Consider the following problem: In a quiz you get two points for each

  14. Emotion dysregulation, problem-solving, and hopelessness.

    Science.gov (United States)

    Vatan, Sevginar; Lester, David; Gunn, John F

    2014-04-01

    A sample of 87 Turkish undergraduate students was administered scales to measure hopelessness, problem-solving skills, emotion dysregulation, and psychiatric symptoms. All of the scores from these scales were strongly associated. In a multiple regression, hopelessness scores were predicted by poor problem-solving skills and emotion dysregulation.

  15. Teaching and Learning through Problem Solving

    Science.gov (United States)

    Ollerton, Mike

    2007-01-01

    In this article, the author relates some problem solving work with primary schools to Department for Children, Schools, and Families (DfES) support. In four primary schools in the West Midlands, the focus was teaching mathematics through problem solving, based on materials published on the DfES "standards" website. The author noticed…

  16. Creativity and Insight in Problem Solving

    Science.gov (United States)

    Golnabi, Laura

    2016-01-01

    This paper analyzes the thought process involved in problem solving and its categorization as creative thinking as defined by psychologist R. Weisberg (2006). Additionally, the notion of insight, sometimes present in unconscious creative thinking and often leading to creative ideas, is discussed in the context of geometry problem solving. In…

  17. The Process of Solving Complex Problems

    Science.gov (United States)

    Fischer, Andreas; Greiff, Samuel; Funke, Joachim

    2012-01-01

    This article is about Complex Problem Solving (CPS), its history in a variety of research domains (e.g., human problem solving, expertise, decision making, and intelligence), a formal definition and a process theory of CPS applicable to the interdisciplinary field. CPS is portrayed as (a) knowledge acquisition and (b) knowledge application…

  18. 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)

  19. Numerical method for solving fuzzy wave equation

    Science.gov (United States)

    Kermani, M. Afshar

    2013-10-01

    In this study a numerical method for solving "fuzzy partial differential equation" (FPDE) is considered. We present difference method to solve the FPDEs such as fuzzy hyperbolic equation, then see if stability of this method exist, and conditions for stability are given.

  20. ALGORITHM FOR SOLVING EXTREME SCHEDULING PROBLEMS

    OpenAIRE

    Gennady A. Berketov

    2015-01-01

    The article considers the original algorithmfor solving the generalized problem ofscheduling theory, based on the branch and bound method. Task schedulingperform works (operations) and restrictions on resources used often occur with scheduling discrete manufacturing operations, optimizing network implementationschedules of scientific, economic or technical projects. Tools to solve suchproblems are included in the decisionsupport system ACS in many businesses.The effectiveness of the proposed ...

  1. 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…

  2. Some Applications of Algebraic System Solving

    Science.gov (United States)

    Roanes-Lozano, Eugenio

    2011-01-01

    Technology and, in particular, computer algebra systems, allows us to change both the way we teach mathematics and the mathematical curriculum. Curiously enough, unlike what happens with linear system solving, algebraic system solving is not widely known. The aim of this paper is to show that, although the theory lying behind the "exact…

  3. Metacognition: Student Reflections on Problem Solving

    Science.gov (United States)

    Wismath, Shelly; Orr, Doug; Good, Brandon

    2014-01-01

    Twenty-first century teaching and learning focus on the fundamental skills of critical thinking and problem solving, creativity and innovation, and collaboration and communication. Metacognition is a crucial aspect of both problem solving and critical thinking, but it is often difficult to get students to engage in authentic metacognitive…

  4. Conceptual Problem Solving in High School Physics

    Science.gov (United States)

    Docktor, Jennifer L.; Strand, Natalie E.; Mestre, José P.; Ross, Brian H.

    2015-01-01

    Problem solving is a critical element of learning physics. However, traditional instruction often emphasizes the quantitative aspects of problem solving such as equations and mathematical procedures rather than qualitative analysis for selecting appropriate concepts and principles. This study describes the development and evaluation of an…

  5. Mathematical problem solving in primary school

    NARCIS (Netherlands)

    Kolovou, A.

    2011-01-01

    A student is engaged in (non-routine) problem solving when there is no clear pathway to the solution. In contrast to routine problems, non-routine ones cannot be solved through the direct application of a standard procedure. Consider the following problem: In a quiz you get two points for each corre

  6. Students' Metaphors for Mathematical Problem Solving

    Science.gov (United States)

    Yee, Sean P.

    2012-01-01

    The purpose of this study was to determine the metaphors used by students to describe mathematical problem solving. This study focused on identifying how students interpret and perceive mathematical problem solving via conceptual metaphors (Lakoff and Johnson, 2003). These perceptions and interpretations were coded and analyzed qualitatively and…

  7. Solving Cubic Equations by Polynomial Decomposition

    Science.gov (United States)

    Kulkarni, Raghavendra G.

    2011-01-01

    Several mathematicians struggled to solve cubic equations, and in 1515 Scipione del Ferro reportedly solved the cubic while participating in a local mathematical contest, but did not bother to publish his method. Then it was Cardano (1539) who first published the solution to the general cubic equation in his book "The Great Art, or, The Rules of…

  8. Mathematics Teachers Circle around Problem Solving

    Science.gov (United States)

    Fernandes, Anthony; Koehler, Jacob; Reiter, Harold

    2011-01-01

    Making problem solving a central part of teaching may be challenging to teachers who have limited experiences in learning and teaching mathematics in this way. Math Teachers' Circles were developed with the aim of establishing a "culture of problem solving" among middle school mathematics teachers. This culture could then be carried back into…

  9. The Functions of Pictures in Problem Solving

    Science.gov (United States)

    Elia, Iliada; Philippou, George

    2004-01-01

    In the present study, we assert that pictures serve four functions in problem solving: decorative, representational, organizational and informational. We, therefore, investigate the effects of pictures based on their functions in mathematical problem solving (MPS), by high achievement students of Grade 6 in Cyprus, in a communication setting. A…

  10. Creativity and Insight in Problem Solving

    Science.gov (United States)

    Golnabi, Laura

    2016-01-01

    This paper analyzes the thought process involved in problem solving and its categorization as creative thinking as defined by psychologist R. Weisberg (2006). Additionally, the notion of insight, sometimes present in unconscious creative thinking and often leading to creative ideas, is discussed in the context of geometry problem solving. In…

  11. The Development of Potential Problem Solving of Students, Mahasarakham University

    Directory of Open Access Journals (Sweden)

    Amorn Suwannimitr

    2010-01-01

    other group of students who unable to solve the problem, the research found that some of them were out of emotional control. They were avoidance and lack of self confident to solve the problem. It was not significantly different between gender. (t = 0.956, p>0.05, but it is significantly different between group. It shown that the Health Science group were able to solve the problem better than the Humanity-Social Science and Science and Technology groups, (p = 0.000. By the way, it was not significantly different between the Humanity-Social Science and Science and Technology groups (p = 0.839. Conclusion: The findings suggested the strategies of problem solving potential development should be develop by covering these elements: (1 to develop the strengthening of mental and insight (2 to develop the learning system and (3 to develop leadership more than that it should develop the instructors role in teaching by using problem solving technique including with supportive system from the academic institute.

  12. Producer-Scrounger Method to Solve Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    M. A. H. Akhand

    2015-02-01

    Full Text Available Algorithms inspired from natural phenomena are seem to be efficient to solve various optimization problems. This paper investigates a new technique inspiring from the animal group living behavior to solve traveling salesman problem (TSP, the most popular combinatorial optimization problem. The proposed producer-scrounger method (PSM models roles and interactions of three types of animal group members: producer, scrounger and dispersed. PSM considers a producer having the best tour, few dispersed members having worse tours and scroungers. In each iteration, the producer scans for better tour, scroungers explore new tours while moving toward producer‘s tour; and dispersed members randomly checks new tours. For producer‘s scanning, PSM randomly selects a city from the producer‘s tour and rearranges its connection with several near cities for better tours. Swap operator and swap sequence based operation is employed in PSM to update a scrounger towards the producer. The proposed PSM has been tested on a large number of benchmark TSPs and outcomes compared to genetic algorithm and ant colony optimization. Experimental results revealed that proposed PSM is a good technique to solve TSP providing the best tours in most of the TSPs.

  13. Enigma of Runaway Stars Solved

    Science.gov (United States)

    1997-01-01

    Supernova Propels Companion Star through Interstellar Space The following success story is a classical illustration of scientific progress through concerted interplay of observation and theory. It concerns a 35-year old mystery which has now been solved by means of exciting observations of a strange double star. An added touch is the successive involvement of astronomers connected to the European Southern Observatory. For many years, astronomers have been puzzled by the fact that, among the thousands of very young, hot and heavy stars which have been observed in the Milky Way, there are some that move with exceptionally high velocities. In some cases, motions well above 100 km/sec, or ten times more than normal for such stars, have been measured. How is this possible? Which mechanism is responsible for the large amounts of energy needed to move such heavy bodies at such high speeds? Could it be that these stars are accelerated during the powerful explosion of a companion star as a supernova? Such a scenario was proposed in 1961 by Adriaan Blaauw [1], but until now, observational proof has been lacking. Now, however, strong supporting evidence for this mechanism has become available from observations obtained at the ESO La Silla observatory. The mysterious runaway stars OB-runaway stars [2] are heavy stars that travel through interstellar space with an anomalously high velocity. They have been known for several decades, but it has always been a problem to explain their high velocities. Although most OB-runaway stars are located at distances of several thousands of lightyears, their high velocity results in a measurable change in position on sky photos taken several years apart. The velocity component in the direction of the Earth can be measured very accurately from a spectrogram. From a combination of such observations, it is possible to measure the space velocity of OB-runaways. Bow shocks reveal runaway stars It has also been found that some OB-runaways display

  14. Lesion mapping of social problem solving.

    Science.gov (United States)

    Barbey, Aron K; Colom, Roberto; Paul, Erick J; Chau, Aileen; Solomon, Jeffrey; Grafman, Jordan H

    2014-10-01

    Accumulating neuroscience evidence indicates that human intelligence is supported by a distributed network of frontal and parietal regions that enable complex, goal-directed behaviour. However, the contributions of this network to social aspects of intellectual function remain to be well characterized. Here, we report a human lesion study (n = 144) that investigates the neural bases of social problem solving (measured by the Everyday Problem Solving Inventory) and examine the degree to which individual differences in performance are predicted by a broad spectrum of psychological variables, including psychometric intelligence (measured by the Wechsler Adult Intelligence Scale), emotional intelligence (measured by the Mayer, Salovey, Caruso Emotional Intelligence Test), and personality traits (measured by the Neuroticism-Extraversion-Openness Personality Inventory). Scores for each variable were obtained, followed by voxel-based lesion-symptom mapping. Stepwise regression analyses revealed that working memory, processing speed, and emotional intelligence predict individual differences in everyday problem solving. A targeted analysis of specific everyday problem solving domains (involving friends, home management, consumerism, work, information management, and family) revealed psychological variables that selectively contribute to each. Lesion mapping results indicated that social problem solving, psychometric intelligence, and emotional intelligence are supported by a shared network of frontal, temporal, and parietal regions, including white matter association tracts that bind these areas into a coordinated system. The results support an integrative framework for understanding social intelligence and make specific recommendations for the application of the Everyday Problem Solving Inventory to the study of social problem solving in health and disease.

  15. Assertiveness and problem solving in midwives.

    Science.gov (United States)

    Yurtsal, Zeliha Burcu; Özdemir, Levent

    2015-01-01

    Midwifery profession is required to bring solutions to problems and a midwife is expected to be an assertive person and to develop midwifery care. This study was planned to examine the relationship between assertiveness and problem-solving skills of midwives. This cross-sectional study was conducted with 201 midwives between July 2008 and February 2009 in the city center of Sivas. The Rathus Assertiveness Schedule (RAS) and Problem Solving Inventory (PSI) were used to determine the level of assertiveness and problem-solving skills of midwives. Statistical methods were used as mean, standard deviation, percentage, Student's T, ANOVA and Tukey HSD, Kruskal Wallis, Fisher Exact, Pearson Correlation and Chi-square tests and P assertiveness levels and problem solving skills of midwives, and midwives who were assertive solved their problems better than did others. Assertiveness and problem-solving skills training will contribute to the success of the midwifery profession. Midwives able to solve problems, and display assertive behaviors will contribute to the development of midwifery profession.

  16. Disciplinary Foundations for Solving Interdisciplinary Scientific Problems

    Science.gov (United States)

    Zhang, Dongmei; Shen, Ji

    2015-10-01

    Problem-solving has been one of the major strands in science education research. But much of the problem-solving research has been conducted on discipline-based contexts; little research has been done on how students, especially individuals, solve interdisciplinary problems. To understand how individuals reason about interdisciplinary problems, we conducted an interview study with 16 graduate students coming from a variety of disciplinary backgrounds. During the interviews, we asked participants to solve two interdisciplinary science problems on the topic of osmosis. We investigated participants' problem reasoning processes and probed in their attitudes toward general interdisciplinary approach and specific interdisciplinary problems. Through a careful inductive content analysis of their responses, we studied how disciplinary, cognitive, and affective factors influenced their interdisciplinary problems-solving. We found that participants' prior discipline-based science learning experiences had both positive and negative influences on their interdisciplinary problem-solving. These influences were embodied in their conceptualization of the interdisciplinary problems, the strategies they used to integrate different disciplinary knowledge, and the attitudes they had toward interdisciplinary approach in general and specific interdisciplinary problems. This study sheds light on interdisciplinary science education by revealing the complex relationship between disciplinary learning and interdisciplinary problem-solving.

  17. Problem-solving model in radiology for medical students.

    Science.gov (United States)

    Blane, C E; Vydareny, K H; Ten Haken, J D; Calhoun, J G

    1989-05-01

    Current undergraduate medical education is criticized for not preparing physicians to be independent thinkers. The rapid development of new imaging techniques and the problem of escalating medical costs call for efficient patient management. The development of algorithms in imaging work-up of patient problems is an excellent example of problem solving or medical decision making. The senior elective in radiology at our institution incorporates this type of problem-solving session. Small groups (15-25 students) with faculty guidance discuss 5-6 common patient problems to develop an investigative plan in imaging. Algorithms are thus developed by the group, but not presented for memorization. Small changes are then made in the case history so that the students are forced to make new hypotheses and generate a modified algorithm. Correlative costs are included. Flexibility and initiative in development of patient management algorithms are stressed.

  18. A Collocation Method for Solving Fractional Riccati Differential Equation

    Directory of Open Access Journals (Sweden)

    Yalçın Öztürk

    2013-01-01

    Full Text Available We have introduced a Taylor collocation method, which is based on collocation method for solving fractional Riccati differential equation with delay term. This method is based on first taking the truncated Taylor expansions of the solution function in the fractional Riccati differential equation and then substituting their matrix forms into the equation. Using collocation points, we have the system of nonlinear algebraic equation. Then, we solve the system of nonlinear algebraic equation using Maple 13, and we have the coefficients of the truncated Taylor sum. In addition, illustrative examples are presented to demonstrate the effectiveness of the proposed method. Comparing the methodology with some known techniques shows that the present approach is relatively easy and highly accurate.

  19. Solving the Schroedinger equation using Smolyak interpolants.

    Science.gov (United States)

    Avila, Gustavo; Carrington, Tucker

    2013-10-07

    In this paper, we present a new collocation method for solving the Schroedinger equation. Collocation has the advantage that it obviates integrals. All previous collocation methods have, however, the crucial disadvantage that they require solving a generalized eigenvalue problem. By combining Lagrange-like functions with a Smolyak interpolant, we device a collocation method that does not require solving a generalized eigenvalue problem. We exploit the structure of the grid to develop an efficient algorithm for evaluating the matrix-vector products required to compute energy levels and wavefunctions. Energies systematically converge as the number of points and basis functions are increased.

  20. PSQP: Puzzle Solving by Quadratic Programming.

    Science.gov (United States)

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

    2017-02-01

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

  1. 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.

  2. Factors Influencing Mathematic Problem-Solving Ability of Sixth Grade Students

    Directory of Open Access Journals (Sweden)

    Sakorn Pimta

    2009-01-01

    Full Text Available Problem statement: This study aims to investigate factors influencing mathematic problem-solving ability of sixth grade students. One thousand and twenty eight of sixth grade students, studying in the second semester of academic year 2007 were sampled by stratified random sampling technique. Approach: The research instruments used in the study included mathematic problem-solving ability test and questionnaires. Data was analyzed by Path Analysis. Results: Factors influencing mathematic problem-solving ability were represented as following: (1 direct factors influencing mathematic problem-solving ability were described that direct and indirect factors influencing mathematic problem-solving ability were attitude towards mathematics, self-esteem and teachers’ teaching behavior. Indirect factors influencing mathematic problem-solving ability were motivation and self-efficacy (2 factor models influencing mathematic problem-solving ability of sixth grade students was associated with visual data (3 The developed model could describe variance of skill in mathematic problem-solving at 63.00 % (R2 = 0.63. Conclusion: Teacher’s behaviors took both direct and indirect effects on the students’ mathematic problem solving. The teachers are supposed to study the methods to develop this ability deeply and then bring them to manage the activities in class that encourage students to be enthusiastic to learn and have good attitude toward mathematic learning or to get students’ concentration.

  3. Three-Dimensional Profiles Using a Spherical Cutting Bit: Problem Solving in Practice

    Science.gov (United States)

    Ollerton, Richard L.; Iskov, Grant H.; Shannon, Anthony G.

    2002-01-01

    An engineering problem concerned with relating the coordinates of the centre of a spherical cutting tool to the actual cutting surface leads to a potentially rich example of problem-solving techniques. Basic calculus, Lagrange multipliers and vector calculus techniques are employed to produce solutions that may be compared to better understand…

  4. Thinking about Applications: Effects on Mental Models and Creative Problem-Solving

    Science.gov (United States)

    Barrett, Jamie D.; Peterson, David R.; Hester, Kimberly S.; Robledo, Issac C.; Day, Eric A.; Hougen, Dean P.; Mumford, Michael D.

    2013-01-01

    Many techniques have been used to train creative problem-solving skills. Although the available techniques have often proven to be effective, creative training often discounts the value of thinking about applications. In this study, 248 undergraduates were asked to develop advertising campaigns for a new high-energy soft drink. Solutions to this…

  5. Experimental techniques; Techniques experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Roussel-Chomaz, P. [GANIL CNRS/IN2P3, CEA/DSM, 14 - Caen (France)

    2007-07-01

    This lecture presents the experimental techniques, developed in the last 10 or 15 years, in order to perform a new class of experiments with exotic nuclei, where the reactions induced by these nuclei allow to get information on their structure. A brief review of the secondary beams production methods will be given, with some examples of facilities in operation or under project. The important developments performed recently on cryogenic targets will be presented. The different detection systems will be reviewed, both the beam detectors before the targets, and the many kind of detectors necessary to detect all outgoing particles after the reaction: magnetic spectrometer for the heavy fragment, detection systems for the target recoil nucleus, {gamma} detectors. Finally, several typical examples of experiments will be detailed, in order to illustrate the use of each detector either alone, or in coincidence with others. (author)

  6. Physics: Quantum problems solved through games

    Science.gov (United States)

    Maniscalco, Sabrina

    2016-04-01

    Humans are better than computers at performing certain tasks because of their intuition and superior visual processing. Video games are now being used to channel these abilities to solve problems in quantum physics. See Letter p.210

  7. Improving mathematical problem solving : A computerized approach

    NARCIS (Netherlands)

    Harskamp, EG; Suhre, CJM

    Mathematics teachers often experience difficulties in teaching students to become skilled problem solvers. This paper evaluates the effectiveness of two interactive computer programs for high school mathematics problem solving. Both programs present students with problems accompanied by instruction

  8. Information problem solving and mental effort

    NARCIS (Netherlands)

    Brand-Gruwel, Saskia; Frerejean, Jimmy

    2012-01-01

    Brand-Gruwel, S., & Frerejean, J. (2012, 5 September). Information problem solving and mental effort. Presentation at the EARLI ASC 2012 "Using eye tracking to design and evaluate education & training methods", Heerlen, The Netherlands.

  9. Problem Solving Methods in Engineering Design

    DEFF Research Database (Denmark)

    Hartvig, Susanne C

    1999-01-01

    This short paper discusses typical engineering tasks and problem solving methods, based on a field study of engineering tasks at a Danish engineering firm. The field study has identified ten classes of design tasks and in this paper these classes are related to problem solving methods. The descri......This short paper discusses typical engineering tasks and problem solving methods, based on a field study of engineering tasks at a Danish engineering firm. The field study has identified ten classes of design tasks and in this paper these classes are related to problem solving methods....... The described work is part of a project that aims at establishing a coherent framework for future development of integrated design tools....

  10. An Open Environment for Cooperative Equational Solving

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We describe a system called CFLP which aims at the integration ofthe best featu res of functional logic programming (FLP), cooperative constraint solving (CCS), and distributed computing. FLP provides support for defining one's own abstract ions over a constraint domain in an easy and comfortable way, whereas CCS is emp loyed to solve systems of mixed constraints by iterating specialized constraint solving methods in accordance with a well defined strategy. The system is a di s tributed implementation of a cooperative constraint functional logic programming scheme that combines higher-order lazy narrowing with cooperative constraint s o lving. The model takes advantage of the existence of several constraint solving resources located in a distributed environment (e.g., a network of computers), w hich communicate asynchronously via message passing. To increase the openness of the system, we are redesigning CFLP based on CORBA. We discuss some design and implementation issues of the system.

  11. Productive Dialog During Collaborative Problem Solving

    CERN Document Server

    Hausmann, Robert G M; van de Sande, Carla; VanLehn, Kurt

    2008-01-01

    Collaboration is an important problem-solving skill; however, novice collaboration generally benefits from some kind of support. One possibility for supporting productive conversations between collaborators is to encourage pairs of students to provide explanations for their problem-solving steps. To test this possibility, we contrasted individuals who were instructed to self-explain problem-solving steps with dyads who were instructed to jointly explain problem-solving steps in the context of an intelligent tutoring system (ITS). The results suggest that collaboratively developed explanations prompted students to remediate their errors in dialog, as opposed to relying on the ITS for assistance, which is provided in the form of on-demand hints. The paper concludes with a discussion about implications for combining proven learning interventions.

  12. How to solve applied mathematics problems

    CERN Document Server

    Moiseiwitsch, B L

    2011-01-01

    This workbook bridges the gap between lectures and practical applications, offering students of mathematics, engineering, and physics the chance to practice solving problems from a wide variety of fields. 2011 edition.

  13. Improving mathematical problem solving : A computerized approach

    NARCIS (Netherlands)

    Harskamp, EG; Suhre, CJM

    2006-01-01

    Mathematics teachers often experience difficulties in teaching students to become skilled problem solvers. This paper evaluates the effectiveness of two interactive computer programs for high school mathematics problem solving. Both programs present students with problems accompanied by instruction

  14. 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.

  15. Photoreactors for Solving Problems of Environmental Pollution

    Science.gov (United States)

    Tchaikovskaya, O. N.; Sokolova, I. V.

    2015-04-01

    Designs and physical aspects of photoreactors, their capabilities for a study of kinetics and mechanisms of processes proceeding under illumination with light, as well as application of photoreactors for solving various applied problem are discussed.

  16. Solving recurrence relations supported by Wolfram Mathematica

    Directory of Open Access Journals (Sweden)

    Enrique Vílchez-Quesada

    2015-01-01

    Full Text Available This paper introduces some algorithms for solving linear relationships, homogeneous and non-homogeneous recurrence with constant and non-constant coefficients, using software as the main resource in solving processes. The Mathematica commercial application has provided the technical support necessary for the implementation of the methods used. It also presents other examples of recurrence relations, showing the effectiveness and limitations of the algorithms created by the author and programmed in Mathematica environment that provides.

  17. Solving traveling salesman problems by genetic algorithms

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The gene section ordering on solving traveling salesman problems is analyzed by numerical experiments. Some improved crossover operations are presented. Several combinations of genetic operations are examined and the functions of these operations are analyzed. The essentiality of the ordering of the gene section and the significance of the evolutionary inversion operation are discussed. Some results and conclusions are obtained and given, which provide useful information for the implementation of the genetic operations for solving the traveling salesman problem.

  18. Exact Algorithms for Solving Stochastic Games

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Koucky, Michal; Lauritzen, Niels;

    2012-01-01

    Shapley's discounted stochastic games, Everett's recursive games and Gillette's undiscounted stochastic games are classical models of game theory describing two-player zero-sum games of potentially infinite duration. We describe algorithms for exactly solving these games.......Shapley's discounted stochastic games, Everett's recursive games and Gillette's undiscounted stochastic games are classical models of game theory describing two-player zero-sum games of potentially infinite duration. We describe algorithms for exactly solving these games....

  19. An Algorithm for Solving Quadratic Programming Problems

    Directory of Open Access Journals (Sweden)

    V. Moraru

    1997-08-01

    Full Text Available Herein is investigated the method of solution of quadratic programming problems. The algorithm is based on the effective selection of constraints. Quadratic programming with constraints-equalities are solved with the help of an algorithm, so that matrix inversion is avoided, because of the more convenient organization of the Calculus. Optimal solution is determined in a finite number of iterations. It is discussed the extension of the algorithm over solving quadratic non-convex programming problems.

  20. Conceptual problem solving in high school physics

    Science.gov (United States)

    Docktor, Jennifer L.; Strand, Natalie E.; Mestre, José P.; Ross, Brian H.

    2015-12-01

    Problem solving is a critical element of learning physics. However, traditional instruction often emphasizes the quantitative aspects of problem solving such as equations and mathematical procedures rather than qualitative analysis for selecting appropriate concepts and principles. This study describes the development and evaluation of an instructional approach called Conceptual Problem Solving (CPS) which guides students to identify principles, justify their use, and plan their solution in writing before solving a problem. The CPS approach was implemented by high school physics teachers at three schools for major theorems and conservation laws in mechanics and CPS-taught classes were compared to control classes taught using traditional problem solving methods. Information about the teachers' implementation of the approach was gathered from classroom observations and interviews, and the effectiveness of the approach was evaluated from a series of written assessments. Results indicated that teachers found CPS easy to integrate into their curricula, students engaged in classroom discussions and produced problem solutions of a higher quality than before, and students scored higher on conceptual and problem solving measures.

  1. Collection of solved problems in physics

    Science.gov (United States)

    Koupilová, ZdeÅka; Mandíková, Dana; Snětinová, Marie

    2017-01-01

    To solve physics problems is a key ability which students should reach during their physics education. Ten years ago we started to develop a Collection of fully solved problems. The structure of problems' solutions is specially designed to substitute tutor's help during lesson and encourage students to solve at least some parts of a problem independently. Nowadays the database contains about 770 fully solved problems in physics in Czech, more than 100 problems in Polish and more than 140 problems in English. Other problems are still being translated. Except for physics problems, the Collection has also a mathematical part, which contains more than 300 fully solved problems in mathematics. This paper follows the presentation of the Collection of solved problems from previous years and introduces a new interface of the Collection, its enhanced functionality, new topics, newly created interface for teachers, user feedback and plans for future development. The database is placed at the website of the Department of Physics Education, Faculty of Mathematics and Physics, Charles University in Prague, the links are: http://reseneulohy.cz/fyzika (Czech version); http://www.physicstasks.eu/ (English version).

  2. Trading a Problem-solving Task

    Science.gov (United States)

    Matsubara, Shigeo

    This paper focuses on a task allocation problem, especially cases where the task is to find a solution in a search problem or a constraint satisfaction problem. If the search problem is hard to solve, a contractor may fail to find a solution. Here, the more computational resources such as the CPU time the contractor invests in solving the search problem, the more a solution is likely to be found. This brings about a new problem that a contractee has to find an appropriate level of the quality in a task achievement as well as to find an efficient allocation of a task among contractors. For example, if the contractee asks the contractor to find a solution with certainty, the payment from the contractee to the contractor may exceed the contractee's benefit from obtaining a solution, which discourages the contractee from trading a task. However, solving this problem is difficult because the contractee cannot ascertain the contractor's problem-solving ability such as the amount of available resources and knowledge (e.g. algorithms, heuristics) or monitor what amount of resources are actually invested in solving the allocated task. To solve this problem, we propose a task allocation mechanism that is able to choose an appropriate level of the quality in a task achievement and prove that this mechanism guarantees that each contractor reveals its true information. Moreover, we show that our mechanism can increase the contractee's utility compared with a simple auction mechanism by using computer simulation.

  3. Introduction to computational techniques for boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Blottner, F.G.

    1979-09-01

    Finite-difference procedures to solve boundary layer flows in fluid mechanics are explained. The governing equations and the transformations utilized are described. Basic solution techniques are illustrated with the similar boundary layer equations. Nonsimilar solutions are developed for the incompressible equations. Various example problems are solved, and the numerical results in the Fortran listing of the computer codes are presented.

  4. A Model for Solving the Maxwell Quasi Stationary Equations in a 3-Phase Electric Reduction Furnace

    Directory of Open Access Journals (Sweden)

    S. Ekrann

    1982-10-01

    Full Text Available A computer code has been developed for the approximate computation of electric and magnetic fields within an electric reduction furnace. The paper describes the numerical methods used to solve Maxwell's quasi-stationary equations, which are the governing equations for this problem. The equations are discretized by a staggered grid finite difference technique. The resulting algebraic equations are solved by iterating between computations of electric and magnetic quantities. This 'outer' iteration converges only when the skin depth is larger or of about the same magnitude as the linear dimensions of the computational domain. In solving for electric quantities with magnetic quantities being regarded as known, and vice versa, the central computational task is the solution of a Poisson equation for a scalar potential. These equations are solved by line successive overrelaxation combined with a rebalancing technique.

  5. The Effect of Learning Environments Based on Problem Solving on Students’ Achievements of Problem Solving

    Directory of Open Access Journals (Sweden)

    Ilhan KARATAS

    2013-07-01

    Full Text Available Problem solving is recognized as an important life skill involving a range of processes including analyzing, interpreting, reasoning, predicting, evaluating and reflecting. For that reason educatingstudents as efficient problem solvers is an important role of mathematics education. Problem solving skill is the centre of mathematics curriculum. Students’ gaining of that skill in school mathematics is closely related with the learning environment to beformed and the roles given to the students. The aim of this study is to create a problem solving based learning environment to enhance the students’ problem solving skill. Within this scope, students’practiced activities and problems that provide them to proceed in Polya (1945’s problem solving phases and throughout the study, students’ success in problem solving have been evaluated. While experimental group students received problem solving based learning environment performed, control group students have continued their present program in this quise1experimental study. Eleven problem solving activities were given to the students at the beginning, middle and end of the study and the students’ performances wereanalyzed based on problem solving phases. The findings illustrated that the experimental group students’ success in problem solving activities has increased while the control group students’ success has not changed significantly.

  6. Solving the quadratic assignment problem with clues from nature.

    Science.gov (United States)

    Nissen, V

    1994-01-01

    This paper describes a new evolutionary approach to solving quadratic assignment problems. The proposed technique is based loosely on a class of search and optimization algorithms known as evolution strategies (ES). These methods are inspired by the mechanics of biological evolution and have been applied successfully to a variety of difficult problems, particularly in continuous optimization. The combinatorial variant of ES presented here performs very well on the given test problems as compared with the standard 2-Opt heuristic and results with simulated annealing and tabu search. Extensions for practical applications in factory layout are described.

  7. Polynomial system solving for decoding linear codes and algebraic cryptanalysis

    OpenAIRE

    2009-01-01

    This thesis is devoted to applying symbolic methods to the problems of decoding linear codes and of algebraic cryptanalysis. The paradigm we employ here is as follows. We reformulate the initial problem in terms of systems of polynomial equations over a finite field. The solution(s) of such systems should yield a way to solve the initial problem. Our main tools for handling polynomials and polynomial systems in such a paradigm is the technique of Gröbner bases and normal form reductions. The ...

  8. Solving Nonlinear Partial Differential Equations with Maple and Mathematica

    CERN Document Server

    Shingareva, Inna K

    2011-01-01

    The emphasis of the book is given in how to construct different types of solutions (exact, approximate analytical, numerical, graphical) of numerous nonlinear PDEs correctly, easily, and quickly. The reader can learn a wide variety of techniques and solve numerous nonlinear PDEs included and many other differential equations, simplifying and transforming the equations and solutions, arbitrary functions and parameters, presented in the book). Numerous comparisons and relationships between various types of solutions, different methods and approaches are provided, the results obtained in Maple an

  9. On the variational data assimilation problem solving and sensitivity analysis

    Science.gov (United States)

    Arcucci, Rossella; D'Amore, Luisa; Pistoia, Jenny; Toumi, Ralf; Murli, Almerico

    2017-04-01

    We consider the Variational Data Assimilation (VarDA) problem in an operational framework, namely, as it results when it is employed for the analysis of temperature and salinity variations of data collected in closed and semi closed seas. We present a computing approach to solve the main computational kernel at the heart of the VarDA problem, which outperforms the technique nowadays employed by the oceanographic operative software. The new approach is obtained by means of Tikhonov regularization. We provide the sensitivity analysis of this approach and we also study its performance in terms of the accuracy gain on the computed solution. We provide validations on two realistic oceanographic data sets.

  10. Multivariate Padé Approximation for Solving Nonlinear Partial Differential Equations of Fractional Order

    Directory of Open Access Journals (Sweden)

    Veyis Turut

    2013-01-01

    Full Text Available Two tecHniques were implemented, the Adomian decomposition method (ADM and multivariate Padé approximation (MPA, for solving nonlinear partial differential equations of fractional order. The fractional derivatives are described in Caputo sense. First, the fractional differential equation has been solved and converted to power series by Adomian decomposition method (ADM, then power series solution of fractional differential equation was put into multivariate Padé series. Finally, numerical results were compared and presented in tables and figures.

  11. Genetic algorithms and smoothing filters in solving the geophysical inversion problem

    Directory of Open Access Journals (Sweden)

    Šešum Vesna

    2002-01-01

    Full Text Available The combination of genetic algorithms, smoothing filters and geophysical tomography is used in solving the geophysical inversion problem. This hybrid technique is developed to improve the results obtained by using genetic algorithm sonly. The application of smoothing filters can improve the performance of GA implementation for solving the geophysical inversion problem. Some test-examples and the obtained comparative results are presented.

  12. The Convergence Study of the Homotopy Analysis Method for Solving Nonlinear Volterra-Fredholm Integrodifferential Equations

    Directory of Open Access Journals (Sweden)

    Behzad Ghanbari

    2014-01-01

    Full Text Available We aim to study the convergence of the homotopy analysis method (HAM in short for solving special nonlinear Volterra-Fredholm integrodifferential equations. The sufficient condition for the convergence of the method is briefly addressed. Some illustrative examples are also presented to demonstrate the validity and applicability of the technique. Comparison of the obtained results HAM with exact solution shows that the method is reliable and capable of providing analytic treatment for solving such equations.

  13. Some observations on a new numerical method for solving Navier-Stokes equations

    Science.gov (United States)

    Kumar, A.

    1981-01-01

    An explicit-implicit technique for solving Navier-Stokes equations is described which, is much less complex than other implicit methods. It is used to solve a complex, two-dimensional, steady-state, supersonic-flow problem. The computational efficiency of the method and the quality of the solution obtained from it at high Courant-Friedrich-Lewy (CFL) numbers are discussed. Modifications are discussed and certain observations are made about the method which may be helpful in using it successfully.

  14. A new method for solving a class of heat conduction equations

    Directory of Open Access Journals (Sweden)

    Tian Yi

    2015-01-01

    Full Text Available A numerical method for solving a class of heat conduction equations with variable coefficients in one dimensional space is demonstrated. This method combines the Crank-Nicolson and Monte Carlo methods. Using Crank-Nicolson method, the governing equations are discretized into a large sparse system of linear algebraic equations, which are solved by Monte Carlo method. To illustrate the usefulness of this technique, we apply it to two problems. Numerical results show the performance of the present work.

  15. Solving Minimal Covering Location Problems with Single and Multiple Node Coverage

    Directory of Open Access Journals (Sweden)

    Darko DRAKULIĆ

    2016-12-01

    Full Text Available Location science represents a very attractiveresearch field in combinatorial optimization and it is in expansion in last five decades. The main objective of location problems is determining the best position for facilities in a given set of nodes.Location science includes techniques for modelling problemsand methods for solving them. This paper presents results of solving two types of minimal covering location problems, with single and multiple node coverage, by using CPLEX optimizer and Particle Swarm Optimization method.

  16. Solving Nonstiff Higher Order Odes Using Variable Order Step Size Backward Difference Directly

    Directory of Open Access Journals (Sweden)

    Ahmad Fadly Nurullah Rasedee

    2014-01-01

    Full Text Available The current numerical techniques for solving a system of higher order ordinary differential equations (ODEs directly calculate the integration coefficients at every step. Here, we propose a method to solve higher order ODEs directly by calculating the integration coefficients only once at the beginning of the integration and if required once more at the end. The formulae will be derived in terms of backward difference in a constant step size formulation. The method developed will be validated by solving some higher order ODEs directly using variable order step size. To simplify the evaluations of the integration coefficients, we find the relationship between various orders. The results presented confirmed our hypothesis.

  17. A new neural network model for solving random interval linear programming problems.

    Science.gov (United States)

    Arjmandzadeh, Ziba; Safi, Mohammadreza; Nazemi, Alireza

    2017-05-01

    This paper presents a neural network model for solving random interval linear programming problems. The original problem involving random interval variable coefficients is first transformed into an equivalent convex second order cone programming problem. A neural network model is then constructed for solving the obtained convex second order cone problem. Employing Lyapunov function approach, it is also shown that the proposed neural network model is stable in the sense of Lyapunov and it is globally convergent to an exact satisfactory solution of the original problem. Several illustrative examples are solved in support of this technique.

  18. A novel computing three-dimensional differential transform method for solving fuzzy partial differential equations

    Directory of Open Access Journals (Sweden)

    Farshid Mirzaee

    2016-06-01

    Full Text Available In this paper, we introduce three-dimensional fuzzy differential transform method and we utilize it to solve fuzzy partial differential equations. This technique is a successful method because of reducing such problems to solve a system of algebraic equations; so, the problem can be solved directly. A considerable advantage of this method is to obtain the analytical solutions if the equation has an exact solution that is a polynomial function. Numerical examples are included to demonstrate the validity and applicability of the method.

  19. Solving Resource-constrained Multiple Project Scheduling Problem Using Timed Colored Petri Nets

    Institute of Scientific and Technical Information of China (English)

    WU Yu; ZHUANG Xin-cun; SONG Guo-hui; XU Xiao-dong; LI Cong-xin

    2009-01-01

    To solve the resource-constrained multiple project scheduling problem (RCMPSP) more effectively, a method based on timed colored Petri net (TCPN) was proposed. In this methodology, firstly a novel mapping mechanism between traditional network diagram such as CPM (critical path method)/PERT (program evaluation and review technique) and TCPN was presented. Then a primary TCPN (PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism. Meanwhile, the object PTCPN was used to simulate the multiple projects scheduling and to find the approximately optimal value of RCMPSP. Finally, the performance of the proposed approach for solving RCMPSP was validated by executing a mould manufacturing example.

  20. Fish School Search Algorithm for Solving Optimal Reactive Power Dispatch Problem

    Directory of Open Access Journals (Sweden)

    K. Lenin

    2013-01-01

    Full Text Available This paper presents an algorithm for solving the multi-objective reactive power dispatch problem in a power system. Modal analysis of the system is used for static voltage stability assessment. Loss minimization and maximization of voltage stability margin are taken as the objectives. Generator terminal voltages, reactive power generation of the capacitor banks and tap changing transformer setting are taken as the optimization variables. This paper presents fish school search a novel method of swarm intelligence for solving above problem. Fish school search Algorithm, which was inspired by the natural schooling behaviours of fish, a powerful stochastic optimization technique has been utilised to solve the reactive power optimization problem.

  1. Transfer Between Analogies: How Solving One Analogy Problem Helps to Solve Another

    OpenAIRE

    Keane, Mark T.

    1995-01-01

    This paper deals with transfer between analogies; with what people acquire from one analogy problem-solving episode that can be re-applied to a subsequent analogy, problem-solving episode. This issue must be resolved if we are to understand the nature of expertise and the appropriate use of analogy in education. There are two main explanations of what subjects acquire from an analogy problem-solving episode. The schema-induction hypothesis maintains that subjects acquire an abs...

  2. The Effect of Problem Solving Teaching with Texts of Turkish Lesson on Students’ Problem Solving Skills

    Directory of Open Access Journals (Sweden)

    Havva ILGIN

    2012-08-01

    Full Text Available In this research, by carrying out activities based on texts, effect of providing problem solving skill on students’ levels of problem solving attainment was tried to be identified. Research was performed according to pretest-posttest Experimental Model with Control Group, in 2008-2009 educational year at second grade of an elementary school in Denizli province. For nine weeks, four hours in a week, while teacher guide book was being followed in control group in Turkish language lesson, texts were carried out with problem solving activities in experimental group. In the research, “Problem Solving Test” which were used as data collection tools, were developed by benefiting from matching of attainment-problem solving steps-cognitive domain steps. Problem Solving Test is made up of 16 multiple choice and 9 open ended questions. In the analysis of data, t test was used. It was found that problem solving teaching succeeded at “identifying different possible solutions in the light of collected data, applying the decided way of solution, evaluating types of solutions, evaluating used problem solving method” stages of problem solving.

  3. Why students still can't solve physics problems after solving over 2000 problems

    Science.gov (United States)

    Byun, Taejin; Lee, Gyoungho

    2014-09-01

    This study investigates the belief that solving a large number of physics problems helps students better learn physics. We investigated the number of problems solved, student confidence in solving these problems, academic achievement, and the level of conceptual understanding of 49 science high school students enrolled in upper-level physics classes from Spring 2010 to Summer 2011. The participants solved an average of 2200 physics problems before entering high school. Despite having solved so many problems, no statistically significant correlation was found between the number of problems solved and academic achievement on either a mid-term or physics competition examination. In addition, no significant correlation was found between the number of physics problems solved and performance on the Force Concept Inventory (FCI). Lastly, four students were selected from the 49 participants with varying levels of experience and FCI scores for a case study. We determined that their problem solving and learning strategies was more influential in their success than the number of problems they had solved.

  4. Basic Techniques of Blacksmithing: A Manual for Trainers.

    Science.gov (United States)

    Watson, Pete; And Others

    Designed for trainers of Peace Corps Volunteers, this guide contains instructional materials for a training program in basic blacksmithing skills. The objective is to give volunteers a knowledge of metals and metalworking that will help them support rural communities in developing countries in their efforts to produce tools for agricultural and…

  5. Solving jigsaw puzzles using image features

    DEFF Research Database (Denmark)

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

    2008-01-01

    algorithm which exploits the divide and conquer paradigm to reduce the combinatorially complex problem by classifying the puzzle pieces and comparing pieces drawn from the same group. The paper includes a brief preliminary investigation of some image features used in the classification.......In this article, we describe a method for automatic solving of the jigsaw puzzle problem based on using image features instead of the shape of the pieces. The image features are used for obtaining an accurate measure for edge similarity to be used in a new edge matching algorithm. The algorithm...... is used in a general puzzle solving method which is based on a greedy algorithm previously proved successful. We have been able to solve computer generated puzzles of 320 pieces as well as a real puzzle of 54 pieces by exclusively using image information. Additionally, we investigate a new scalable...

  6. Local Strategy Improvement for Parity Game Solving

    Directory of Open Access Journals (Sweden)

    Oliver Friedmann

    2010-06-01

    Full Text Available The problem of solving a parity game is at the core of many problems in model checking, satisfiability checking and program synthesis. Some of the best algorithms for solving parity game are strategy improvement algorithms. These are global in nature since they require the entire parity game to be present at the beginning. This is a distinct disadvantage because in many applications one only needs to know which winning region a particular node belongs to, and a witnessing winning strategy may cover only a fractional part of the entire game graph. We present a local strategy improvement algorithm which explores the game graph on-the-fly whilst performing the improvement steps. We also compare it empirically with existing global strategy improvement algorithms and the currently only other local algorithm for solving parity games. It turns out that local strategy improvement can outperform these others by several orders of magnitude.

  7. On Teaching Problem Solving in School Mathematics

    Directory of Open Access Journals (Sweden)

    Erkki Pehkonen

    2013-12-01

    Full Text Available The article begins with a brief overview of the situation throughout the world regarding problem solving. The activities of the ProMath group are then described, as the purpose of this international research group is to improve mathematics teaching in school. One mathematics teaching method that seems to be functioning in school is the use of open problems (i.e., problem fields. Next we discuss the objectives of the Finnish curriculum that are connected with problem solving. Some examples and research results are taken from a Finnish–Chilean research project that monitors the development of problem-solving skills in third grade pupils. Finally, some ideas on “teacher change” are put forward. It is not possible to change teachers, but only to provide hints for possible change routes: the teachers themselves should work out the ideas and their implementation.

  8. Comparisons of Learning Achievement and Problem-Solving Thinking Abilities of Vocational Certificate Level 1 Students between Learning Management of Creative Problem Solving and Conventional Learning Approaches

    Directory of Open Access Journals (Sweden)

    Komkrit Chookhom

    2016-10-01

    Full Text Available The purposes of this study aimed to: 1 develop plan for creative problem solving learning activities with a required efficiency of 80/80, 2 find out effectiveness indices of the plan for creative problem solving learning activities, 3 compare learning achievements, problem-solving thinking abilities of the students who learned using creative problem solving learning activities between pretest and posttest, 4 compare learning achievements, problem-solving thinking abilities of the students who learned using conventional learning approaches between pretest and posttest, and 5 compare learning achievements, problem-solving thinking abilities of the students who learned using creative problem solving learning activities and those who conventional learning approaches, The samples for this study consisted of vocational certificate level 1 students in second semester of the academic year of 2014, Kantharalak Technical College. They were selected using the cluster random sampling technique and randomly divided into two groups: the experimental group one learning by creative problem solving learning activities, and the other one experimental group learning by conventional learning approaches. The tools used in the study were: 1 plans for creative problem solving learning activities and conventional Learning approaches, The instruments used in this study were: 6 units, 3 hours per week in each plan, for a total of 18 hours of teaching 2 a 30 items 4 choice achievement test with discriminating powers (B ranging 0.22-0.63 with a reliability (rcc of 0.86, and 3 a 28 item 4 choice test of problem-solving thinking with discriminating powers (B ranging 0.22-0.71 with a reliability (rcc of 0.76. Basic statistics used for analyzing the collected data were percentage, mean, and standard deviation, and the statistic used for testing the hypotheses was Hotelling’s T2 . The results of the study were as follows: 1. The efficiencies of the plan for creative problem

  9. Solving network design problems via decomposition, aggregation and approximation

    CERN Document Server

    Bärmann, Andreas

    2016-01-01

    Andreas Bärmann develops novel approaches for the solution of network design problems as they arise in various contexts of applied optimization. At the example of an optimal expansion of the German railway network until 2030, the author derives a tailor-made decomposition technique for multi-period network design problems. Next, he develops a general framework for the solution of network design problems via aggregation of the underlying graph structure. This approach is shown to save much computation time as compared to standard techniques. Finally, the author devises a modelling framework for the approximation of the robust counterpart under ellipsoidal uncertainty, an often-studied case in the literature. Each of these three approaches opens up a fascinating branch of research which promises a better theoretical understanding of the problem and an increasing range of solvable application settings at the same time. Contents Decomposition for Multi-Period Network Design Solving Network Design Problems via Ag...

  10. SOLVING GLOBAL PROBLEMS USING COLLABORATIVE DESIGN PROCESSES

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Mejborn, Christina Okai

    2011-01-01

    new solutions that would help solve the global problem of sanitation. Lack of sanitation is a problem for 42% of the world’s population but it is also a taboo topic that only very few people will engage in. In the one-day workshop participants from very different areas came together and brought...... forward proposed solutions for how to design, brand and make business models for how to solve aspects of the sanitation problem. The workshop showed that it was possible to work freely with such a taboo topic and that in particular the use of visualisation tools, i.e. drawing posters and building simple...

  11. Vacuum engineering, calculations, formulas, and solved exercises

    CERN Document Server

    Berman, Armand

    1992-01-01

    This book was written with two main objectives in mind-to summarize and organize the vast material of vacuum technology in sets of useful formulas, and to provide a collection of worked out exercises showing how to use these formulas for solving technological problems. It is an ideal reference source for those with little time to devote to a full mathematical treatment of the many problems issued in vacuum practice, but who have a working knowledge of the essentials of vacuum technology, elementary physics, and mathematics. This time saving book employs a problem-solving approach throughout, p

  12. Mathematical problem solving in primary school

    OpenAIRE

    Kolovou, A

    2011-01-01

    A student is engaged in (non-routine) problem solving when there is no clear pathway to the solution. In contrast to routine problems, non-routine ones cannot be solved through the direct application of a standard procedure. Consider the following problem: In a quiz you get two points for each correct answer. If a question is not answered or the answer is wrong, one point is subtracted from your score. The quiz contains 10 questions. Tina received 8 points in total. How many questions did Tin...

  13. A Novel Approach for Solving Semidefinite Programs

    Directory of Open Access Journals (Sweden)

    Hong-Wei Jiao

    2014-01-01

    Full Text Available A novel linearizing alternating direction augmented Lagrangian approach is proposed for effectively solving semidefinite programs (SDP. For every iteration, by fixing the other variables, the proposed approach alternatively optimizes the dual variables and the dual slack variables; then the primal variables, that is, Lagrange multipliers, are updated. In addition, the proposed approach renews all the variables in closed forms without solving any system of linear equations. Global convergence of the proposed approach is proved under mild conditions, and two numerical problems are given to demonstrate the effectiveness of the presented approach.

  14. Solve the Master Equation in Python

    CERN Document Server

    Fan, Wei; Chen, Bing; Ye, Qianqian

    2011-01-01

    A brief introduction to the Python computing environment is given. By solving the master equation encountered in quantum transport, we give an example of how to solve the ODE problems in Python. The ODE solvers used are the ZVODE routine in Scipy and the bsimp solver in GSL. For the former, the equation can be in its complex-valued form, while for the latter, it has to be rewritten to a real-valued form. The focus is on the detailed workflow of the implementation process, rather than on the syntax of the python language, with the hope to help readers simulate their own models in Python.

  15. Enhancing decision-making effectiveness in problem-solving teams.

    Science.gov (United States)

    Bazan, S

    1998-01-01

    Active participation by all group members as well as the generation, presentation, and critical evaluation of a wide range of perspectives and alternatives are hallmarks of effective problem-solving teams. Diverse groups with an odd number of participants (five to seven members are generally best) are manageable and provide an adequate range of perspectives and alternatives. Several problems limit the effectiveness of problem-solving teams. Dysfunctional concurrence or "groupthink" occurs when concurrence seeking in cohesive groups overrides the realistic appraisal of alternative courses of action. Managers initially should withhold their own opinions, assign members the role of critical evaluators, and bring in people from outside the initial group to minimize this problem. Domination by a select few is also a problem because it can squelch the presentation of diverse opinions. Brainstorming and nominal group technique can mitigate this problem. In nominal group technique, a manager guides the group through steps involving brainstorming, recording, and voting on the merits of various alternatives before open discussion is allowed. Decision-making dropouts are group members who withdraw from active participation in the group. Managers can reduce this problem by emphasizing the importance of active participation and by monitoring performance.

  16. USSR Report: Machine Tools and Metalworking Equipment.

    Science.gov (United States)

    2007-11-02

    RABOCHAYA GAZETA, 29 Mar 85) AUTOMATED LINES AND AGGREGATED MACHINING SYSTEMS Flexible Production Systems in CEMA Countries Viewed (A. Poplekhin...Automation Equipment Eyed Flexible Module in Odessa ROBOTICS Leningrad Robotics Institute Heads CEMA Group (L. Chausov; PRAVDA, 4 Nov 85) Robot...FLEXIBLE PRODUCTION SYSTEMS IN CEMA COUNTRIES VIEWED Moscow SOTSIALISTICHESKAYA INDUSTRIYA in Russian 16 Mar 85 p 3 [Article by A. Poplekhin: "The Impact

  17. 15 CFR 700.31 - Metalworking machines.

    Science.gov (United States)

    2010-01-01

    ... Drilling and tapping machines Electrical discharge, ultrasonic and chemical erosion machines Forging..., power driven Machining centers and way-type machines Manual presses Mechanical presses, power...

  18. USSR Report, Machine Tools and Metalworking Equipment

    Science.gov (United States)

    2007-11-02

    workers proposals made at the All-Union Correspondence Conference on the eve of the October Plenum of the CPSU Central Committee, having deter- mined ...Moscow MASHINOSTROITEL in Russian No 1, Jan 86 p 11 [Article by I. V. Stepanishohev, engineer: "Mechanized Manufacturing Line"] [Text] The Donetsk

  19. USSR Report Machine Tools and Metalworking Equipment

    Science.gov (United States)

    2007-11-02

    determined, therefore, by the shape of the machined surface and is spatial , i.e., kinematically the most complicated one, different for each machined...place in a single hour. But in actuality? Perhaps it began when they began to study the loading of the production capacities of the sections... kindergartens , the machine tools are outdated and there is nowhere to rest." "At that time I said to myself: ’First achieve their confidence; this

  20. USSR Report Machine Tools and Metalworking Equipment

    Science.gov (United States)

    1986-02-12

    and into the Druzhba oil pipeline . At that time, many were awarded orders and medals and L.A. Dyachenko became a Hero of Socialist Labor. These...and oil pipelines . We bought them from the capitalists.— "Until the angry rooster pecked," said, in remembering that time, Lev

  1. Linear delta expansion technique for the solution of anharmonic oscillations

    Indian Academy of Sciences (India)

    P K Bera; J Datta

    2007-01-01

    The linear delta expansion technique has been developed for solving the differential equation of motion for symmetric and asymmetric anharmonic oscillators. We have also demonstrated the sophistication and simplicity of this new perturbation technique.

  2. Teaching Problem Solving without Modeling through "Thinking Aloud Pair Problem Solving."

    Science.gov (United States)

    Pestel, Beverly C.

    1993-01-01

    Reviews research relevant to the problem of unsatisfactory student problem-solving abilities and suggests a teaching strategy that addresses the issue. Author explains how she uses teaching aloud problem solving (TAPS) in college chemistry and presents evaluation data. Among the findings are that the TAPS class got fewer problems completely right,…

  3. Assessing Affect after Mathematical Problem Solving Tasks: Validating the Chamberlin Affective Instrument for Mathematical Problem Solving

    Science.gov (United States)

    Chamberlin, Scott A.; Powers, Robert A.

    2013-01-01

    The focus of the article is the validation of an instrument to assess gifted students' affect after mathematical problem solving tasks. Participants were 225 students identified by their district as gifted in grades four to six. The Chamberlin Affective Instrument for Mathematical Problem Solving was used to assess feelings, emotions, and…

  4. Students' Errors in Solving the Permutation and Combination Problems Based on Problem Solving Steps of Polya

    Science.gov (United States)

    Sukoriyanto; Nusantara, Toto; Subanji; Chandra, Tjang Daniel

    2016-01-01

    This article was written based on the results of a study evaluating students' errors in problem solving of permutation and combination in terms of problem solving steps according to Polya. Twenty-five students were asked to do four problems related to permutation and combination. The research results showed that the students still did a mistake in…

  5. The Effect of Learning Environments Based on Problem Solving on Students' Achievements of Problem Solving

    Science.gov (United States)

    Karatas, Ilhan; Baki, Adnan

    2013-01-01

    Problem solving is recognized as an important life skill involving a range of processes including analyzing, interpreting, reasoning, predicting, evaluating and reflecting. For that reason educating students as efficient problem solvers is an important role of mathematics education. Problem solving skill is the centre of mathematics curriculum.…

  6. Encouraging Sixth-Grade Students' Problem-Solving Performance by Teaching through Problem Solving

    Science.gov (United States)

    Bostic, Jonathan D.; Pape, Stephen J.; Jacobbe, Tim

    2016-01-01

    This teaching experiment provided students with continuous engagement in a problem-solving based instructional approach during one mathematics unit. Three sections of sixth-grade mathematics were sampled from a school in Florida, U.S.A. and one section was randomly assigned to experience teaching through problem solving. Students' problem-solving…

  7. Understanding Individual Problem-Solving Style: A Key to Learning and Applying Creative Problem Solving

    Science.gov (United States)

    Treffinger, Donald J.; Selby, Edwin C.; Isaksen, Scott G.

    2008-01-01

    More than five decades of research and development have focused on making the Creative Problem Solving process and tools accessible across a wide range of ages and contexts. Recent evidence indicates that when individuals, in both school and corporate settings, understand their own style of problem solving, they are able to learn and apply process…

  8. Writing about the Problem-Solving Process To Improve Problem-Solving Performance.

    Science.gov (United States)

    Williams, Kenneth M.

    2003-01-01

    Concludes that writing about the executive processes of problem solving, difficulties encountered, alternative strategies that might have been used, and the problem solving process in general helped students in the treatment group learn to use executive processes more quickly and more effectively than students in the control group. (Author/NB)

  9. Teaching, Learning and Assessing Statistical Problem Solving

    Science.gov (United States)

    Marriott, John; Davies, Neville; Gibson, Liz

    2009-01-01

    In this paper we report the results from a major UK government-funded project, started in 2005, to review statistics and handling data within the school mathematics curriculum for students up to age 16. As a result of a survey of teachers we developed new teaching materials that explicitly use a problem-solving approach for the teaching and…

  10. Newton type methods for solving nonsmooth equations

    Institute of Scientific and Technical Information of China (English)

    Gao Yan

    2005-01-01

    Numerical methods for the solution of nonsmooth equations are studied. A new subdifferential for a locally Lipschitzian function is proposed. Based on this subdifferential, Newton methods for solving nonsmooth equations are developed and their convergence is shown. Since this subdifferential is easy to be computed, the present Newton methods can be executed easily in some applications.

  11. The art and science of problem solving

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    2005-01-01

    In this paper we will document that real-life problem solving in complex situations demands both rational (scientific) and intuitive (artistic) thinking. First, the concepts of art and science will be discussed; differences and similarities will be enhanced. Thereafter the concept of group proble...

  12. Using CAS to Solve Classical Mathematics Problems

    Science.gov (United States)

    Burke, Maurice J.; Burroughs, Elizabeth A.

    2009-01-01

    Historically, calculus has displaced many algebraic methods for solving classical problems. This article illustrates an algebraic method for finding the zeros of polynomial functions that is closely related to Newton's method (devised in 1669, published in 1711), which is encountered in calculus. By exploring this problem, precalculus students…

  13. Problem-Solving: Scaling the "Brick Wall"

    Science.gov (United States)

    Benson, Dave

    2011-01-01

    Across the primary and secondary phases, pupils are encouraged to use and apply their knowledge, skills, and understanding of mathematics to solve problems in a variety of forms, ranging from single-stage word problems to the challenge of extended rich tasks. Amongst many others, Cockcroft (1982) emphasised the importance and relevance of…

  14. Euler's Amazing Way to Solve Equations.

    Science.gov (United States)

    Flusser, Peter

    1992-01-01

    Presented is a series of examples that illustrate a method of solving equations developed by Leonhard Euler based on an unsubstantiated assumption. The method integrates aspects of recursion relations and sequences of converging ratios and can be extended to polynomial equation with infinite exponents. (MDH)

  15. A program to solve rotating plasma problems

    NARCIS (Netherlands)

    Bakker, M.; Berg, M.S. van den

    1980-01-01

    It is shown that the solution of a rotating plasma problem minimizes a quitably chosen funtional. This variational problem is solved by the Ritz-Galerkin methud using piecewise bilinear functions and applying some Newton-Côtes-like quadrature. The resulting linear system with a sparse nonegative def

  16. Why Some Communities Can Solve Their Problems.

    Science.gov (United States)

    Mathews, David

    1989-01-01

    Effective communities are well-educated about themselves, have a better understanding of public information, talk through public issues to generate shared knowledge, appreciate the difference between public opinion and public judgment, and believe in public leadership as the key to using public power to solve community problems. (SK)

  17. Latest Trends in Problem Solving Assessment

    Directory of Open Access Journals (Sweden)

    Maria Karyotaki

    2016-07-01

    Full Text Available Problem solving is the skill that coordinates all the cognitive, metacognitive and behavioral processes taking place when individuals encounter a previously unprecedented situation or difficulty. Metacognitive processes seem to play the most important role for resolving a problematic situation as individuals reflect on their acquired knowledge, skills and experiences, thus become aware of their capabilities and how to regulate them. Therefore, metacognitive awareness is the competence that mostly assists individuals in their attempt to construct new knowledge and reach their goals. Furthermore, individuals’ self-assessment and peer-assessment processes could reveal their level of metacognitive awareness and therefore, by far, their problem solving competency. Consequently, ICTs could capture individuals’ problem solving skills through tracking down and analyzing the latters’ cognitive and metacognitive processes as well as their behavioral patterns. The aforementioned computer-based assessment could consist of a fuzzy expert system with domain knowledge from an automated task-based test with particular solution strategies in combination with log data for identifying and classifying one’s level of problem solving ability according to specific criteria.

  18. Nanomedicine: Problem Solving to Treat Cancer

    Science.gov (United States)

    Hemling, Melissa A.; Sammel, Lauren M.; Zenner, Greta; Payne, Amy C.; Crone, Wendy C.

    2006-01-01

    Many traditional classroom science and technology activities often ask students to complete prepackaged labs that ensure that everyone arrives at the same "scientifically accurate" solution or theory, which ignores the important problem-solving and creative aspects of scientific research and technological design. Students rarely have the…

  19. Using Bibliotherapy To Teach Problem Solving.

    Science.gov (United States)

    Forgan, James W.

    2002-01-01

    This article discusses how students with high-incidence disabilities can benefit from using bibliotherapy by learning to become proactive problem solvers. A sample lesson plan is presented based on a teaching framework for bibliotherapy and problem solving that contains the elements of prereading, guided reading, post-reading discussion, and a…

  20. Collaborative Problem Solving Methods towards Critical Thinking

    Science.gov (United States)

    Yin, Khoo Yin; Abdullah, Abdul Ghani Kanesan; Alazidiyeen, Naser Jamil

    2011-01-01

    This research attempts to examine the collaborative problem solving methods towards critical thinking based on economy (AE) and non economy (TE) in the SPM level among students in the lower sixth form. The quasi experiment method that uses the modal of 3X2 factorial is applied. 294 lower sixth form students from ten schools are distributed…

  1. Solving Wicked Problems through Action Learning

    Science.gov (United States)

    Crul, Liselore

    2014-01-01

    This account of practice outlines the Oxyme Action Learning Program which was conducted as part of the Management Challenge in my final year of the MSc in Coaching and Behavioral Change at Henley Business School. The central research questions were: (1) how action learning can help to solve wicked problems and (2) what the effect of an action…

  2. Stoichiometric Problem Solving in High School Chemistry.

    Science.gov (United States)

    Schmidt, Hans-Jurgen

    The purpose of this descriptive study was to create and test questions on stoichiometry with number ratios for quick mental calculations and to identify students' problem-solving strategies. The present study was a component of a more comprehensive investigation in which 7,441 German senior high school students were asked to work on 154 test items…

  3. Solvægge i simuleringsprogrammer

    DEFF Research Database (Denmark)

    Wittchen, K.B.

    Rapporten beskriver hvordan solvægge kan implementeres i programmer til beregning af bygningers energi- og temperaturforhold, med tsbi3 (edb-program til termisk simulering af bygninger og installationer) som et konkret eksempel. Der opstilles løsninger for nogle af de processer, som har størst be...

  4. New Ways to Solve the Schroedinger Equation

    CERN Document Server

    Friedberg, R

    2004-01-01

    We discuss a new approach to solve the low lying states of the Schroedinger equation. For a fairly large class of problems, this new approach leads to convergent iterative solutions, in contrast to perturbative series expansions. These convergent solutions include the long standing difficult problem of a quartic potential with either symmetric or asymmetric minima.

  5. Solving Problems of Practice in Education.

    Science.gov (United States)

    Boyd, Robert D.; Menlo, Allen

    1984-01-01

    Discusses the many complexities involved in the translation of scientific information in the social sciences into forms usable for solving problems of practice in education. Prescribes a series of stages to be followed from the advent of a practitioner's situational problem to the design of a response to it. (Author/JN)

  6. GIS Live and Web Problem Solving

    Science.gov (United States)

    Hagevik, R.; Hales, D.; Harrell, J.

    2007-01-01

    GIS Live is a live, interactive, web problem-solving (WPS) program that partners Geographic Information Systems (GIS) professionals with educators to implement geospatial technologies as curriculum-learning tools. It is a collaborative effort of many government agencies, educational institutions, and professional organizations. Problem-based…

  7. Should Children Learn to Solve Problems?

    Science.gov (United States)

    Watras, Joseph

    2011-01-01

    In this comparative essay, the author discusses the opposing educational theories of John Dewey and Gregory Bateson. While Dewey believed that the scientific method was the dominant method of solving problems and thereby acquiring knowledge that mattered, Bateson warned that this one-sided approach would lead to actions that could destroy the…

  8. Solving Problems with the Percentage Bar

    Science.gov (United States)

    van Galen, Frans; van Eerde, Dolly

    2013-01-01

    At the end of primary school all children more of less know what a percentage is, but yet they often struggle with percentage problems. This article describes a study in which students of 13 and 14 years old were given a written test with percentage problems and a week later were interviewed about the way they solved some of these problems. In a…

  9. Mental Imagery in Creative Problem Solving.

    Science.gov (United States)

    Polland, Mark J.

    In order to investigate the relationship between mental imagery and creative problem solving, a study of 44 separate accounts reporting mental imagery experiences associated with creative discoveries were examined. The data included 29 different scientists, among them Albert Einstein and Stephen Hawking, and 9 artists, musicians, and writers,…

  10. A reflexive perspective in problem solving

    Directory of Open Access Journals (Sweden)

    Chio, José Angel

    2013-01-01

    Full Text Available The objective of this paper is to favour the methodological process of reflexive analysis in problem solving in the general teaching methods that concentrates in strengthening the dimensional analysis, to gain a greater preparation of the students for the solution of mathematical problems.

  11. Complex Problem Solving in a Workplace Setting.

    Science.gov (United States)

    Middleton, Howard

    2002-01-01

    Studied complex problem solving in the hospitality industry through interviews with six office staff members and managers. Findings show it is possible to construct a taxonomy of problem types and that the most common approach can be termed "trial and error." (SLD)

  12. Emerging representation technologies for problem solving

    NARCIS (Netherlands)

    Jong, de Ton; Spector, J. Michael; Merrill, M. David; Elen, Jan; Bishop, M.J.

    2014-01-01

    When learners solve problems they often create an external representation to organize the information given in the problem statement, to translate this problem description into underlying domain terms, and to complete this with knowledge they already have. This representation is subsequently used to

  13. Solving Wicked Problems through Action Learning

    Science.gov (United States)

    Crul, Liselore

    2014-01-01

    This account of practice outlines the Oxyme Action Learning Program which was conducted as part of the Management Challenge in my final year of the MSc in Coaching and Behavioral Change at Henley Business School. The central research questions were: (1) how action learning can help to solve wicked problems and (2) what the effect of an action…

  14. Problem-Solving Test: Tryptophan Operon Mutants

    Science.gov (United States)

    Szeberenyi, Jozsef

    2010-01-01

    This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

  15. Facilitating Problem Solving in High School Chemistry.

    Science.gov (United States)

    Gabel, Dorothy L.; Sherwood, Robert D.

    1983-01-01

    Investigated superiority of instructional strategies (factor-label method, proportionality, use of analogies, use of diagrams) in teaching problem-solving related to mole concept, gas laws, stoichiometry, and molarity. Also investigated effectiveness of strategies for students (N=609) with different verbal-visual preferences, proportional…

  16. Solving Nonlinear Wave Equations by Elliptic Equation

    Institute of Scientific and Technical Information of China (English)

    FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo

    2003-01-01

    The elliptic equation is taken as a transformation and applied to solve nonlinear wave equations. It is shown that this method is more powerful to give more kinds of solutions, such as rational solutions, solitary wave solutions,periodic wave solutions and so on, so it can be taken as a generalized method.

  17. Metaphor and analogy in everyday problem solving.

    Science.gov (United States)

    Keefer, Lucas A; Landau, Mark J

    2016-11-01

    Early accounts of problem solving focused on the ways people represent information directly related to target problems and possible solutions. Subsequent theory and research point to the role of peripheral influences such as heuristics and bodily states. We discuss how metaphor and analogy similarly influence stages of everyday problem solving: Both processes mentally map features of a target problem onto the structure of a relatively more familiar concept. When individuals apply this structure, they use a well-known concept as a framework for reasoning about real world problems and candidate solutions. Early studies found that analogy use helped people gain insight into novel problems. More recent research on metaphor goes further to show that activating mappings has subtle, sometimes surprising effects on judgment and reasoning in everyday problem solving. These findings highlight situations in which mappings can help or hinder efforts to solve problems. WIREs Cogn Sci 2016, 7:394-405. doi: 10.1002/wcs.1407 For further resources related to this article, please visit the WIREs website.

  18. Using CAS to Solve Classical Mathematics Problems

    Science.gov (United States)

    Burke, Maurice J.; Burroughs, Elizabeth A.

    2009-01-01

    Historically, calculus has displaced many algebraic methods for solving classical problems. This article illustrates an algebraic method for finding the zeros of polynomial functions that is closely related to Newton's method (devised in 1669, published in 1711), which is encountered in calculus. By exploring this problem, precalculus students…

  19. Discovering Steiner Triple Systems through Problem Solving

    Science.gov (United States)

    Sriraman, Bharath

    2004-01-01

    An attempt to implement problem solving as a teacher of ninth grade algebra is described. The problems selected were not general ones, they involved combinations and represented various situations and were more complex which lead to the discovery of Steiner triple systems.

  20. Facilitating problem solving in high school chemistry

    Science.gov (United States)

    Gabel, Dorothy L.; Sherwood, Robert D.

    The major purpose for conducting this study was to determine whether certain instructional strategies were superior to others in teaching high school chemistry students problem solving. The effectiveness of four instructional strategies for teaching problem solving to students of various proportional reasoning ability, verbal and visual preference, and mathematics anxiety were compared in this aptitude by treatment interaction study. The strategies used were the factor-label method, analogies, diagrams, and proportionality. Six hundred and nine high school students in eight schools were randomly assigned to one of four teaching strategies within each classroom. Students used programmed booklets to study the mole concept, the gas laws, stoichiometry, and molarity. Problem-solving ability was measured by a series of immediate posttests, delayed posttests and the ACS-NSTA Examination in High School Chemistry. Results showed that mathematics anxiety is negatively correlated with science achievement and that problem solving is dependent on students' proportional reasoning ability. The factor-label method was found to be the most desirable method and proportionality the least desirable method for teaching the mole concept. However, the proportionality method was best for teaching the gas laws. Several second-order interactions were found to be significant when mathematics anxiety was one of the aptitudes involved.

  1. Problem-Solving Test: Southwestern Blotting

    Science.gov (United States)

    Szeberényi, József

    2014-01-01

    Terms to be familiar with before you start to solve the test: Southern blotting, Western blotting, restriction endonucleases, agarose gel electrophoresis, nitrocellulose filter, molecular hybridization, polyacrylamide gel electrophoresis, proto-oncogene, c-abl, Src-homology domains, tyrosine protein kinase, nuclear localization signal, cDNA,…

  2. Extraction of a group-pair relation: problem-solving relation from web-board documents.

    Science.gov (United States)

    Pechsiri, Chaveevan; Piriyakul, Rapepun

    2016-01-01

    This paper aims to extract a group-pair relation as a Problem-Solving relation, for example a DiseaseSymptom-Treatment relation and a CarProblem-Repair relation, between two event-explanation groups, a problem-concept group as a symptom/CarProblem-concept group and a solving-concept group as a treatment-concept/repair concept group from hospital-web-board and car-repair-guru-web-board documents. The Problem-Solving relation (particularly Symptom-Treatment relation) including the graphical representation benefits non-professional persons by supporting knowledge of primarily solving problems. The research contains three problems: how to identify an EDU (an Elementary Discourse Unit, which is a simple sentence) with the event concept of either a problem or a solution; how to determine a problem-concept EDU boundary and a solving-concept EDU boundary as two event-explanation groups, and how to determine the Problem-Solving relation between these two event-explanation groups. Therefore, we apply word co-occurrence to identify a problem-concept EDU and a solving-concept EDU, and machine-learning techniques to solve a problem-concept EDU boundary and a solving-concept EDU boundary. We propose using k-mean and Naïve Bayes to determine the Problem-Solving relation between the two event-explanation groups involved with clustering features. In contrast to previous works, the proposed approach enables group-pair relation extraction with high accuracy.

  3. Differential doppler heterodyning technique

    DEFF Research Database (Denmark)

    Lading, Lars

    1971-01-01

    Measuring velocity without disturbing the moving object is possible by use of the laser doppler heterodyning technique. Theoretical considerations on the doppler shift show that the antenna property of the photodetector can solve an apparent conflict between two different ways of calculating...... the detected doppler frequency. It is found that the doppler frequency for this particular setup is independent of the direction of detection. Investigations of the signal-to-noise ratio (SNR) show that the maximum SNR-considering the optical setup-is obtained by measuring the frequency difference between two...

  4. Is conceptual understanding compromised by a problem-solving emphasis in an introductory physics course?

    Science.gov (United States)

    Ridenour, J.; Feldman, G.; Teodorescu, R.; Medsker, L.; Benmouna, N.

    2013-01-01

    Developing competency in problem solving and enhancing conceptual understanding are primary objectives in introductory physics, and many techniques and tools are available to help instructors achieve them. Pedagogically, we use an easy-to-implement intervention, the ACCESS protocol, to develop and assess problem-solving skills in our SCALE-UP classroom environment for algebra-based physics. Based on our research and teaching experience, an important question has emerged: while primarily targeting improvements in problem-solving and cognitive development, is it necessary that conceptual understanding be compromised? To address this question, we gathered and analyzed information about student abilities, backgrounds, and instructional preferences. We report on our progress and give insights into matching the instructional tools to student profiles in order to achieve optimal learning in group-based active learning. The ultimate goal of our work is to integrate individual student learning needs into a pedagogy that moves students closer to expert-like status in problem solving.

  5. Feedback Control Method Using Haar Wavelet Operational Matrices for Solving Optimal Control Problems

    Directory of Open Access Journals (Sweden)

    Waleeda Swaidan

    2013-01-01

    Full Text Available Most of the direct methods solve optimal control problems with nonlinear programming solver. In this paper we propose a novel feedback control method for solving for solving affine control system, with quadratic cost functional, which makes use of only linear systems. This method is a numerical technique, which is based on the combination of Haar wavelet collocation method and successive Generalized Hamilton-Jacobi-Bellman equation. We formulate some new Haar wavelet operational matrices in order to manipulate Haar wavelet series. The proposed method has been applied to solve linear and nonlinear optimal control problems with infinite time horizon. The simulation results indicate that the accuracy of the control and cost can be improved by increasing the wavelet resolution.

  6. Examining the Solution for Solving Optimization Problems using Swarm Intelligence and Its Applications

    Directory of Open Access Journals (Sweden)

    V. Selvi

    2012-06-01

    Full Text Available - SI is a computational and collective behavioral metaphor that is used for solving problems. The problems can be solved by SI by taking ants, termites, bees and wasps as an example. The application of SI algorithm are ACO, PSO and ABC which have been already applied to solve real world optimization problems in engineering. ACO is a member of SI in which ACO is inspired by the behaviour of ant colonies and it constitutes some metaheuristic optimization. ACO’s aim is to search for an optimal path with the help of graph. In PSO, a solution of continuous optimization problems can be solved , because PSO is population based stochastic optimization techniques for the solution of continuous optimization problem. In ABC the solution for the problem is found with help of foraging behaviour of honey bees. It is also swarm based meta heuristic algorithm. This paper presents the experimental verification of ACO and EACO.

  7. How can we improve problem-solving in undergraduate biology? Applying lessons from 30 years of physics education research

    CERN Document Server

    Hoskinson, Anne-Marie; Knight, Jennifer K

    2012-01-01

    Modern biological problems are complex. If students are to successfully grapple with such problems as scientists and citizens, they need to have practiced solving authentic, complex problems during their undergraduate years. Physics education researchers have investigated student problem-solving for the last three decades. Although the surface features and content of biology problems differ from physics problems, teachers of both sciences want students to learn to explain patterns and processes in the natural world and to make predictions about system behaviors. After surveying literature on problem-solving in physics and biology, we propose how biology education researchers could apply research-supported pedagogical techniques from physics to enhance biology students' problem-solving. First, we characterize the problems that biology students are typically asked to solve. We then describe the development of research-validated physics problem-solving curricula. Finally, we propose how biology scholars can appl...

  8. A Problem Solving Environment Based on CORBA

    Directory of Open Access Journals (Sweden)

    David Lancaster

    2001-01-01

    Full Text Available We have investigated aspects of the design of Problem Solving Environments (PSE by constructing a prototype using CORBA as middleware. The two issues we are mainly concerned with are the use of non-trivial (containing more than just a start method CORBA interfaces for the computational components, and the provision of interactivity using the same mechanisms used for flow control. After describing the design decisions that allow us to investigate these issues, and contrasting them with alternatives, we describe the architecture of the prototype and its use in the context of a study of photonic materials. We argue that having several methods on a component interface can be used to mitigate performance problems that may arise when trying to solve problems in PSE's based on small components. We describe how our mechanism allows a high degree of computational steering over all components.

  9. Imagination as the crank of problem solving

    DEFF Research Database (Denmark)

    Kolbæk, Ditte

    and the imagination of the preferred present or future. Imagination is the foundation of problem solving, in this case the problems identified in the PR. The role of imagination cannot be underestimated in this collaborative process in which the interface between the individual and the collective dimensions merge...... and encourage the participants’ imagination to flow freely in order to redefine reality at work. I see different paths for this exploration: I could look into cultural practices and values concerning relations and interactions among colleagues who have solved a task together (Branco & lopes). Or I could dig...... into who “says” or “decides” what is preferred or favored in the sense of who seems to get the power in the team (Latour, Dunne & Raby). Or I could concentrate on the term “dialogue” (Bakhtin, Bohm, Oliveira). I hope the winterschool will add more view angles to this study.My premature research question is...

  10. Learning Matlab a problem solving approach

    CERN Document Server

    Gander, Walter

    2015-01-01

    This comprehensive and stimulating introduction to Matlab, a computer language now widely used for technical computing, is based on an introductory course held at Qian Weichang College, Shanghai University, in the fall of 2014.  Teaching and learning a substantial programming language aren’t always straightforward tasks. Accordingly, this textbook is not meant to cover the whole range of this high-performance technical programming environment, but to motivate first- and second-year undergraduate students in mathematics and computer science to learn Matlab by studying representative problems, developing algorithms and programming them in Matlab. While several topics are taken from the field of scientific computing, the main emphasis is on programming. A wealth of examples are completely discussed and solved, allowing students to learn Matlab by doing: by solving problems, comparing approaches and assessing the proposed solutions.

  11. How to Solve the Torus Puzzle

    Directory of Open Access Journals (Sweden)

    Masahiro Nakamura

    2012-01-01

    Full Text Available In this paper, we consider the following sliding puzzle called torus puzzle. In an m by n board, there are mn pieces numbered from 1 to mn. Initially, the pieces are placed in ascending order. Then they are scrambled by rotating the rows and columns without the player’s knowledge. The objective of the torus puzzle is to rearrange the pieces in ascending order by rotating the rows and columns. We provide a solution to this puzzle. In addition, we provide lower and upper bounds on the number of steps for solving the puzzle. Moreover, we consider a variant of the torus puzzle in which each piece is colored either black or white, and we present a hardness result for solving it.

  12. Hardness and Methods to Solve CLIQUE

    Institute of Scientific and Technical Information of China (English)

    ZHU Daming; LUAN Junfeng; MA Shaohan

    2001-01-01

    The paper briefly reviews NP-hard optimization problems and their inapproximability. The hardness of solving CLIQUE problem is specifically discussed. A dynamic-programming algorithm and its improved version for CLIQUE are reviewed and some additional analysis is presented. The analysis implies that the improved algorithm, HEWN (hierarchical edge-weighted network), only provides a heuristic or useful method, but cannot be called a polynomial algorithm.

  13. Solving the paradox of monetary profits

    OpenAIRE

    2010-01-01

    Bruun and Heyn-Johnsen (2009) state the paradox that economics has failed to provide a satisfactory explanation of how monetary profits are generated, even though the generation of a physical surplus is an established aspect of non-neoclassical economics. They emphasise that our ability to explain phenomena like the Global Financial Crisis (GFC) will be limited while ever we are still unable to explain this fundamental aspect of capitalism. In fact this paradox can be solved very simply, usin...

  14. 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.

  15. Solving Integer Programming by Evolutionary Soft Agent

    Institute of Scientific and Technical Information of China (English)

    Yin Jian

    2003-01-01

    Many practical problems in commerce and industry involve finding the best way to allocate scarce resources a mong competing activities. This paper focuses on the problem of integer programming, and describes an evolutionary soft agent model to solve it. In proposed model, agent is composed of three components: goal, environment and behavior. Experirnental shows thne model has the characters of parallel computing and goal driving.

  16. Fostering interpersonal problem solving skills in children

    OpenAIRE

    Luciana Carla dos Santos Elias; Edna Maria Marturano

    2016-01-01

    Interpersonal problem solving skills - IPSS are important for psychosocial adaptation of people. This study aimed to evaluate the effectiveness of a program for the development ofHSPI, applied by teachers. Participants were 203 students from a public elementary school, aged between six and ten years, and their teachers. The children were allocated in two groups - intervention and comparison. The groups were evaluated before and after intervention as their social skills, IPSS, beha...

  17. Logic training through algorithmic problem solving

    OpenAIRE

    Ferreira, João Fernando; Mendes, Alexandra; Cunha, Alcino; Baquero, Carlos; Silva, Paulo; L. S. Barbosa; Oliveira, José Nuno Fonseca

    2011-01-01

    Available for individual study only. Although much of mathematics is algorithmic in nature, the skills needed to formulate and solve algorithmic problems do not form an integral part of mathematics education. In particular, logic, which is central to algorithm development, is rarely taught explicitly at preuniversity level, under the justification that it is implicit in mathematics and therefore does not need to be taught as an independent topic. This paper argues in the opposite direction...

  18. Teaching Problem Solving Skills to Elementary Age Students with Autism

    Science.gov (United States)

    Cote, Debra L.; Jones, Vita L.; Barnett, Crystal; Pavelek, Karin; Nguyen, Hoang; Sparks, Shannon L.

    2014-01-01

    Students with disabilities need problem-solving skills to promote their success in solving the problems of daily life. The research into problem-solving instruction has been limited for students with autism. Using a problem-solving intervention and the Self Determined Learning Model of Instruction, three elementary age students with autism were…

  19. Mathematical Problem Solving: A Review of the Literature.

    Science.gov (United States)

    Funkhouser, Charles

    The major perspectives on problem solving of the twentieth century are reviewed--associationism, Gestalt psychology, and cognitive science. The results of the review on teaching problem solving and the uses of computers to teach problem solving are included. Four major issues related to the teaching of problem solving are discussed: (1)…

  20. Dynamical System Method for Solving Ill-Posed Operator Equations

    Institute of Scientific and Technical Information of China (English)

    Xingjun Luo; Suhua Yang

    2007-01-01

    Two dynamical system methods are studied for solving linear ill-posed problems with both operator and right-hand nonexact. The methods solve a Cauchy problem for a linear operator equation which possesses a global solution. The limit of the global solution at infinity solves the original linear equation. Moreover,we also present a convergent iterativeprocess for solving the Cauchy problem.

  1. Teaching Problem Solving Skills to Elementary Age Students with Autism

    Science.gov (United States)

    Cote, Debra L.; Jones, Vita L.; Barnett, Crystal; Pavelek, Karin; Nguyen, Hoang; Sparks, Shannon L.

    2014-01-01

    Students with disabilities need problem-solving skills to promote their success in solving the problems of daily life. The research into problem-solving instruction has been limited for students with autism. Using a problem-solving intervention and the Self Determined Learning Model of Instruction, three elementary age students with autism were…

  2. Learning via problem solving in mathematics education

    Directory of Open Access Journals (Sweden)

    Piet Human

    2009-09-01

    Full Text Available Three forms of mathematics education at school level are distinguished: direct expository teaching with an emphasis on procedures, with the expectation that learners will at some later stage make logical and functional sense of what they have learnt and practised (the prevalent form, mathematically rigorous teaching in terms of fundamental mathematical concepts, as in the so-called “modern mathematics” programmes of the sixties, teaching and learning in the context of engaging with meaningful problems and focused both on learning to become good problem solvers (teaching for problem solving andutilising problems as vehicles for the development of mathematical knowledge andproficiency by learners (problem-centred learning, in conjunction with substantialteacher-led social interaction and mathematical discourse in classrooms.Direct expository teaching of mathematical procedures dominated in school systems after World War II, and was augmented by the “modern mathematics” movement in the period 1960-1970. The latter was experienced as a major failure, and was soon abandoned. Persistent poor outcomes of direct expository procedural teaching of mathematics for the majority of learners, as are still being experienced in South Africa, triggered a world-wide movement promoting teaching mathematics for and via problem solving in the seventies and eighties of the previous century. This movement took the form of a variety of curriculum experiments in which problem solving was the dominant classroom activity, mainly in the USA, Netherlands, France and South Africa. While initially focusing on basic arithmetic (computation with whole numbers and elementary calculus, the problem-solving movement started to address other mathematical topics (for example, elementary statistics, algebra, differential equations around the turn of the century. The movement also spread rapidly to other countries, including Japan, Singapore and Australia. Parallel with the

  3. Solving Nonlinear Euler Equations with Arbitrary Accuracy

    Science.gov (United States)

    Dyson, Rodger W.

    2005-01-01

    A computer program that efficiently solves the time-dependent, nonlinear Euler equations in two dimensions to an arbitrarily high order of accuracy has been developed. The program implements a modified form of a prior arbitrary- accuracy simulation algorithm that is a member of the class of algorithms known in the art as modified expansion solution approximation (MESA) schemes. Whereas millions of lines of code were needed to implement the prior MESA algorithm, it is possible to implement the present MESA algorithm by use of one or a few pages of Fortran code, the exact amount depending on the specific application. The ability to solve the Euler equations to arbitrarily high accuracy is especially beneficial in simulations of aeroacoustic effects in settings in which fully nonlinear behavior is expected - for example, at stagnation points of fan blades, where linearizing assumptions break down. At these locations, it is necessary to solve the full nonlinear Euler equations, and inasmuch as the acoustical energy is of the order of 4 to 5 orders of magnitude below that of the mean flow, it is necessary to achieve an overall fractional error of less than 10-6 in order to faithfully simulate entropy, vortical, and acoustical waves.

  4. Optimal Planning and Problem-Solving

    Science.gov (United States)

    Clemet, Bradley; Schaffer, Steven; Rabideau, Gregg

    2008-01-01

    CTAEMS MDP Optimal Planner is a problem-solving software designed to command a single spacecraft/rover, or a team of spacecraft/rovers, to perform the best action possible at all times according to an abstract model of the spacecraft/rover and its environment. It also may be useful in solving logistical problems encountered in commercial applications such as shipping and manufacturing. The planner reasons around uncertainty according to specified probabilities of outcomes using a plan hierarchy to avoid exploring certain kinds of suboptimal actions. Also, planned actions are calculated as the state-action space is expanded, rather than afterward, to reduce by an order of magnitude the processing time and memory used. The software solves planning problems with actions that can execute concurrently, that have uncertain duration and quality, and that have functional dependencies on others that affect quality. These problems are modeled in a hierarchical planning language called C_TAEMS, a derivative of the TAEMS language for specifying domains for the DARPA Coordinators program. In realistic environments, actions often have uncertain outcomes and can have complex relationships with other tasks. The planner approaches problems by considering all possible actions that may be taken from any state reachable from a given, initial state, and from within the constraints of a given task hierarchy that specifies what tasks may be performed by which team member.

  5. Modelo de regresión de Cox de la pérdida auditiva en trabajadores expuestos a ruido y fluidos de mecanizado o humos metálicos Cox regression model of hearing loss in workers exposed to noise and metalworking fluids or welding fumes

    Directory of Open Access Journals (Sweden)

    J.C. Conte

    2010-04-01

    Full Text Available Fundamento. Los trabajos sobre pérdida auditiva laboral se han centrado clásicamente en el estudio del ruido como causa principal. En la rama del metal es muy común la presencia de contaminantes físicos y químicos. En este artículo se analizan ambos junto con ciertos hábitos personales, con la finalidad de ver su influencia conjunta en la pérdida auditiva laboral. Material y métodos. Se analiza una muestra de 558 trabajadores mediante regresión de Cox con una finalidad explicativa. Se define el carácter de las relaciones causa-efecto existentes entre las variables consideradas, con respecto a tres situaciones: sano/alterado; recuperable/no recuperable; sin caídas en conversacionales/con caídas en conversacionales. Resultados. El análisis refleja que los fluidos de mecanizado, en presencia de ruido, retrasan la adquisición de los diversos grados de alteración auditiva; efecto contrario al que producen los humos metálicos, que adelantan la adquisición de dichos estadios. El hábito de fumar se reconoce como influyente en la adquisición de un trauma acústico inicial; la exposición a ruido extralaboral influye en la adquisición de un trauma acústico avanzado; y por otro lado, los equipos de protección auditiva son protectores del ruido pero no de la ototoxicidad de los humos metálicos. Conclusión. Se pone de manifiesto el efecto antagónico de los fluidos de mecanizado y el sinérgico de los humos metálicos frente al ruido, explicando la variación temporal en la evolución de la alteración auditiva, relacionada con estas atmósferas; se comprueba la influencia del tabaco y del ruido extralaboral, en la adquisición del trauma acústico.Background. Works on labour-related hearing loss have traditionally been centred on the study of noise as the principal cause. The presence of physical and chemical pollutants is very common in the metalworking branch. This article analyses both, together with certain personal habits, with

  6. Spectral-Homotopy Perturbation Method for Solving Governing MHD Jeffery-Hamel Problem

    Directory of Open Access Journals (Sweden)

    Ahmed A. Khidir

    2014-01-01

    Full Text Available We present a new modification of the homotopy perturbation method (HPM for solving nonlinear boundary value problems. The technique is based on the standard homotopy perturbation method and blending of the Chebyshev pseudospectral methods. The implementation of the new approach is demonstrated by solving the MHD Jeffery-Hamel flow and the effect of MHD on the flow has been discussed. Comparisons are made between the proposed technique, the previous studies, the standard homotopy perturbation method, and the numerical solutions to demonstrate the applicability, validity, and high accuracy of the presented approach. The results demonstrate that the new modification is more efficient and converges faster than the standard homotopy perturbation method at small orders. The MATLAB software has been used to solve all the equations in this study.

  7. Solving evolutionary-type differential equations and physical problems using the operator method

    Science.gov (United States)

    Zhukovsky, K. V.

    2017-01-01

    We present a general operator method based on the advanced technique of the inverse derivative operator for solving a wide range of problems described by some classes of differential equations. We construct and use inverse differential operators to solve several differential equations. We obtain operator identities involving an inverse derivative operator, integral transformations, and generalized forms of orthogonal polynomials and special functions. We present examples of using the operator method to construct solutions of equations containing linear and quadratic forms of a pair of operators satisfying Heisenberg-type relations and solutions of various modifications of partial differential equations of the Fourier heat conduction type, Fokker-Planck type, Black-Scholes type, etc. We demonstrate using the operator technique to solve several physical problems related to the charge motion in quantum mechanics, heat propagation, and the dynamics of the beams in accelerators.

  8. A Comparative Study of Geometric Hopfield Network and Ant Colony Algorithm to Solve Travelling Salesperson Problem

    Directory of Open Access Journals (Sweden)

    Yogeesha C.B

    2014-09-01

    Full Text Available The classical methods have limited scope in practical applications as some of them involve objective functions which are not continuous and/or differentiable. Evolutionary Computation is a subfield of artificial intelligence that involves combinatorial optimization problems. Travelling Salesperson Problem (TSP, which considered being a classic example for Combinatorial Optimization problem. It is said to be NP-Complete problem that cannot be solved conventionally particularly when number of cities increase. So Evolutionary techniques is the feasible solution to such problem. This paper explores an evolutionary technique: Geometric Hopfield Neural Network model to solve Travelling Salesperson Problem. Paper also achieves the results of Geometric TSP and compares the result with one of the existing widely used nature inspired heuristic approach Ant Colony Optimization Algorithms (ACA/ACO to solve Travelling Salesperson Problem.

  9. Preconditioning Schur Complement Systems of Highly-Indefinite Linear Systems for a Parallel Hybrid Solve

    Institute of Scientific and Technical Information of China (English)

    I.Yamazaki; X.S.Li; E.G.Ng

    2010-01-01

    A parallel hybrid linear solver based on the Schur complement method has the potential to balance the robustness of direct solvers with the efficiency of precon-ditioned iterative solvers. However, when solving large-scale highly-indefinite linear systems, this hybrid solver often suffers from either slow convergence or large memory requirements to solve the Schur complement systems. To overcome this challenge, we in this paper discuss techniques to preprocess the Schur complement systems in paral-lel. Numerical results of solving large-scale highly-indefinite linear systems from various applications demonstrate that these techniques improve the reliability and performance of the hybrid solver and enable efficient solutions of these linear systems on hundreds of processors, which was previously infeasible using existing state-of-the-art solvers.

  10. The Effect of Learning Environments Based on Problem Solving on Students’ Achievements of Problem Solving

    OpenAIRE

    Ilhan KARATAS; Baki, Adnan

    2013-01-01

    Problem solving is recognized as an important life skill involving a range of processes including analyzing, interpreting, reasoning, predicting, evaluating and reflecting. For that reason educatingstudents as efficient problem solvers is an important role of mathematics education. Problem solving skill is the centre of mathematics curriculum. Students’ gaining of that skill in school mathematics is closely related with the learning environment to beformed and the roles given to the students....

  11. The Effect of Problem Solving Teaching with Texts of Turkish Lesson on Students’ Problem Solving Skills

    OpenAIRE

    ILGIN, Havva; ARSLAN, Derya

    2012-01-01

    In this research, by carrying out activities based on texts, effect of providing problem solving skill on students’ levels of problem solving attainment was tried to be identified. Research was performed according to pretest-posttest Experimental Model with Control Group, in 2008-2009 educational year at second grade of an elementary school in Denizli province. For nine weeks, four hours in a week, while teacher guide book was being followed in control group in Turkish language lesson, texts ...

  12. The Effect of Metacognitive Instruction on Problem Solving Skills in Iranian Students of Health Sciences.

    Science.gov (United States)

    Safari, Yahya; Meskini, Habibeh

    2015-05-17

    Learning requires application of such processes as planning, supervision, monitoring and reflection that are included in the metacognition. Studies have shown that metacognition is associated with problem solving skills. The current research was conducted to investigate the impact of metacognitive instruction on students' problem solving skills. The study sample included 40 students studying in the second semester at Kermanshah University of Medical Sciences, 2013-2014. They were selected through convenience sampling technique and were randomly assigned into two equal groups of experimental and control. For the experimental group, problem solving skills were taught through metacognitive instruction during ten two-hour sessions and for the control group, problem solving skills were taught via conventional teaching method. The instrument for data collection included problem solving inventory (Heppner, 1988), which was administered before and after instruction. The validity and reliability of the questionnaire had been previously confirmed. The collected data were analyzed by descriptive statistics, mean and standard deviation and the hypotheses were tested by t-test and ANCOVA. The findings of the posttest showed that the total mean scores of problem solving skills in the experimental and control groups were 151.90 and 101.65, respectively, indicating a significant difference between them (pproblem solving skills and its components, including problem solving confidence, orientation-avoidance coping style and personal control (pstudents' mean scores in terms of gender and major. Since metacognitive instruction has positive effects on students' problem solving skills and is required to enhance academic achievement, metacognitive strategies are recommended to be taught to the students.

  13. ProE-based 3D modeling technique for solving machining problems of space cant or space inclined hole%基于ProE三维造型技术求解空间斜面或空间斜孔的加工问题

    Institute of Scientific and Technical Information of China (English)

    王贤民

    2012-01-01

    Space inclined hole is always one of the difficult problems in machining.It analyses the common space cant or space inclined hole machining in the combined machine tools design,and by applying ProE three-dimensional modeling technology,angular relationship of space cant or space inclined hole of machined components is solved through the space sectioning methodAny kind of direction vector of space cant or space inclined hole may always be directed at the machining spindle through three times rotation at most,which will simplify the design of the machine tool fixtures.Based on an example for machining motorcycle engine case,the method is illustrated,which results indicate that the fixture designed completely satisfies the requirement of accuracy,and the method is proven to be valuable in popularization and practicability.%加工空间斜孔历来是机械加工中的难题之一.对组合机床设计中常见的空间斜面或空间斜孔的加工问题进行了分析,利用ProE三维造型技术,通过空间剖切方法,求解被加工零件的空间斜面或空间斜孔的角度关系,任何一种空间斜面或者空间斜孔的方向矢量,总可以通过最多3次旋转,使其对准加工主轴,使用该方法机床夹具的设计将能够简化.以摩托车发动机壳体的加工实例来说明该方法使用过程,结果表明所设计的夹具,完全满足精度要求,本实例具有普遍的推广性和实用性.

  14. Solution techniques for elementary partial differential equations

    CERN Document Server

    Constanda, Christian

    2012-01-01

    Incorporating a number of enhancements, Solution Techniques for Elementary Partial Differential Equations, Second Edition presents some of the most important and widely used methods for solving partial differential equations (PDEs). The techniques covered include separation of variables, method of characteristics, eigenfunction expansion, Fourier and Laplace transformations, Green’s functions, perturbation methods, and asymptotic analysis.

  15. USING SIX THINKING HATS AS A TOOL FOR LATERAL THINKING IN ORGANIZATIONAL PROBLEM SOLVING

    OpenAIRE

    Dr. P. S. Aithal; Dr. P. M. Suresh Kumar

    2016-01-01

    Six thinking hats is recently introduced technique which outlines different thinking styles required by an individual while analysing a given problem in an effective way. The technique correlates different thinking styles used in a systematic problem-solving procedure with different coloured hats. Alternately, by conceptualizing each type of hat, the person focuses on the style of thinking associated with each colour so that the problem can be analysed from different angles and frame of refer...

  16. Combinatorial particle swarm optimization for solving blocking flowshop scheduling problem

    Directory of Open Access Journals (Sweden)

    Mansour Eddaly

    2016-10-01

    Full Text Available This paper addresses to the flowshop scheduling problem with blocking constraints. The objective is to minimize the makespan criterion. We propose a hybrid combinatorial particle swarm optimization algorithm (HCPSO as a resolution technique for solving this problem. At the initialization, different priority rules are exploited. Experimental study and statistical analysis were performed to select the most adapted one for this problem. Then, the swarm behavior is tested for solving a combinatorial optimization problem such as a sequencing problem under constraints. Finally, an iterated local search algorithm based on probabilistic perturbation is sequentially introduced to the particle swarm optimization algorithm for improving the quality of solution. The computational results show that our approach is able to improve several best known solutions of the literature. In fact, 76 solutions among 120 were improved. Moreover, HCPSO outperforms the compared methods in terms of quality of solutions in short time requirements. Also, the performance of the proposed approach is evaluated according to a real-world industrial problem.

  17. Solving complex-valued linear systems via equivalent real formulations

    Energy Technology Data Exchange (ETDEWEB)

    DAY,DAVID M.; HEROUX,MICHAEL A.

    2000-05-22

    Most algorithms used in preconditioned iterative methods are generally applicable to complex valued linear systems, with real valued linear systems simply being a special case. However, most iterative solver packages available today focus exclusively on real valued systems, or deal with complex valued systems as an afterthought. One obvious approach to addressing this problem is to recast the complex problem into one of a several equivalent real forms and then use a real valued solver to solve the related system. However, well-known theoretical results showing unfavorable spectral properties for the equivalent real forms have diminished enthusiasm for this approach. At the same time, experience has shown that there are situations where using an equivalent real form can be very effective. In this paper, the authors explore this approach, giving both theoretical and experimental evidence that an equivalent real form can be useful for a number of practical situations. Furthermore, they show that by making good use of some of the advance features of modem solver packages, they can easily generate equivalent real form preconditioners that are computationally efficient and mathematically identical to their complex counterparts. Using their techniques, they are able to solve very ill-conditioned complex valued linear systems for a variety of large scale applications. However, more importantly, they shed more light on the effectiveness of equivalent real forms and more clearly delineate how and when they should be used.

  18. Solving Partial Differential Equations Using a New Differential Evolution Algorithm

    Directory of Open Access Journals (Sweden)

    Natee Panagant

    2014-01-01

    Full Text Available This paper proposes an alternative meshless approach to solve partial differential equations (PDEs. With a global approximate function being defined, a partial differential equation problem is converted into an optimisation problem with equality constraints from PDE boundary conditions. An evolutionary algorithm (EA is employed to search for the optimum solution. For this approach, the most difficult task is the low convergence rate of EA which consequently results in poor PDE solution approximation. However, its attractiveness remains due to the nature of a soft computing technique in EA. The algorithm can be used to tackle almost any kind of optimisation problem with simple evolutionary operation, which means it is mathematically simpler to use. A new efficient differential evolution (DE is presented and used to solve a number of the partial differential equations. The results obtained are illustrated and compared with exact solutions. It is shown that the proposed method has a potential to be a future meshless tool provided that the search performance of EA is greatly enhanced.

  19. BACKPROPAGATION TRAINING ALGORITHM WITH ADAPTIVE PARAMETERS TO SOLVE DIGITAL PROBLEMS

    Directory of Open Access Journals (Sweden)

    R. Saraswathi

    2011-01-01

    Full Text Available An efficient technique namely Backpropagation training with adaptive parameters using Lyapunov Stability Theory for training single hidden layer feed forward network is proposed. A three-layered Feedforward neural network architecture is used to solve the selected problems. Sequential Training Mode is used to train the network. Lyapunov stability theory is employed to ensure the faster and steady state error convergence and to construct and energy surface with a single global minimum point through the adaptive adjustment of the weights and the adaptive parameter ß. To avoid local minima entrapment, an adaptive backpropagation algorithm based on Lyapunov stability theory is used. Lyapunov stability theory gives the algorithm, the efficiency of attaining a single global minimum point. The learning parameters used in this algorithm is responsible for the faster error convergence. The adaptive learning parameter used in this algorithm is chosen properly for faster error convergence. The error obtained has been asymptotically converged to zero according to Lyapunov Stability theory. The performance of the adaptive Backpropagation algorithm is measured by solving parity problem, half adder and full adder problems.

  20. Computer-Presented Organizational/Memory Aids as Instruction for Solving Pico-Fomi Problems.

    Science.gov (United States)

    Steinberg, Esther R.; And Others

    1985-01-01

    Describes investigation of effectiveness of computer-presented organizational/memory aids (matrix and verbal charts controlled by computer or learner) as instructional technique for solving Pico-Fomi problems, and the acquisition of deductive inference rules when such aids are present. Results indicate chart use control should be adapted to…

  1. Construction of a Parallel Algorithm to Solve the Multiphase Gas Dynamics Problem

    Directory of Open Access Journals (Sweden)

    B. Rybakin

    1995-11-01

    Full Text Available This paper considers questions of an effective use of multiprocessor computing system to implement a parallel algorithm solving the multiphase gas dynamics problem. A technique is offered to parallelize the two-dimensional explicit differential scheme to implement it on multiprocessor systems with distributed memory (MIMD architecture.

  2. Analysis of 4th Grade Students' Problem Solving Skills in Terms of Several Variables

    Science.gov (United States)

    Sungur, Gülcan; Bal, Pervin Nedim

    2016-01-01

    The aim of this study is to examine if the level of primary school students in solving problems differs according to some demographic variables. The research is descriptive type in the general survey method, it was carried out with quantitative research techniques. The sample of the study consisted of 587 primary school students in Grade 4. The…

  3. Modified Halfspace-Relaxation Projection Methods for Solving the Split Feasibility Problem

    Directory of Open Access Journals (Sweden)

    Min Li

    2012-01-01

    Full Text Available This paper presents modified halfspace-relaxation projection (HRP methods for solving the split feasibility problem (SFP. Incorporating with the techniques of identifying the optimal step length with positive lower bounds, the new methods improve the efficiencies of the HRP method (Qu and Xiu (2008. Some numerical results are reported to verify the computational preference.

  4. Thinking in Terms of Sensors: Personification of Self as an Object in Physics Problem Solving

    Science.gov (United States)

    Tabor-Morris, A. E.

    2015-01-01

    How can physics teachers help students develop consistent problem solving techniques for both simple and complicated physics problems, such as those that encompass objects undergoing multiple forces (mechanical or electrical) as individually portrayed in free-body diagrams and/or phenomenon involving multiple objects, such as Doppler effect…

  5. New Tack on Math Promoted: Problem-Solving Is Focus of High School Guide

    Science.gov (United States)

    Cavanagh, Sean

    2009-01-01

    Three years after calling for a reordering of elementary and middle school math curricula, the nation's largest group of math teachers is urging a new approach to high school instruction, one that aims to build students' ability to choose and apply the most effective problem-solving techniques, in the classroom and in life. Cultivating those…

  6. The "Iron Inventor": Using Creative Problem Solving to Spur Student Creativity

    Science.gov (United States)

    Lee, Seung Hwan; Hoffman, K. Douglas

    2014-01-01

    Based on the popular television show the "Iron Chef," an innovative marketing activity called the "Iron Inventor" is introduced. Using the creative problem-solving approach and active learning techniques, the Iron Inventor facilitates student learning pertaining to the step-by-step processes of creating a new product and…

  7. Teaching Creative Problem Solving Methods to Undergraduate Economics and Business Students

    Science.gov (United States)

    Cancer, Vesna

    2014-01-01

    This paper seeks to explore the need for and possibility of teaching current and potential problem solvers--undergraduate students in the economic and business field to define problems, to generate and choose creative and useful ideas and to verify them. It aims to select an array of quick and easy-to-use creative problem solving (CPS) techniques.…

  8. Solucion de Problemas y Procesos Cognoscitivos (Problem Solving and Cognitive Processes). Publication No. 41.

    Science.gov (United States)

    Rimoldi, Horacio J. A.

    The study of problem solving is made through the analysis of the process that leads to the final answer. The type of information obtained through the study of the process is compared with the information obtained by studying the final answer. The experimental technique used permits to identify the sequence of questions (tactics) that subjects ask…

  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. A Computer Algebra Approach to Solving Chemical Equilibria in General Chemistry

    Science.gov (United States)

    Kalainoff, Melinda; Lachance, Russ; Riegner, Dawn; Biaglow, Andrew

    2012-01-01

    In this article, we report on a semester-long study of the incorporation into our general chemistry course, of advanced algebraic and computer algebra techniques for solving chemical equilibrium problems. The method presented here is an alternative to the commonly used concentration table method for describing chemical equilibria in general…

  11. impact of the curriculum reform on problem solving ability in chemistry

    African Journals Online (AJOL)

    unesco

    need to first consider the larger question why we teach chemistry? ... knowledge of chemistry, good knowledge of problem solving strategies and .... hoc tukey test statistical techniques were applied to see if there were a ... Therefore, the total scores of each student's PSB and APSK on the ..... Blank space, I don't know,.

  12. Interaction Between Conceptual Level and Training Method in Computer Based Problem Solving.

    Science.gov (United States)

    Sustik, Joan M.; Brown, Bobby R.

    A study of 130 undergraduate students enrolled in a course on auiovisual techniques sought to determine whether heuristic or algorithmic computer-based problem solving training would be differentially effective for students varying in cognitive complexity as measured by the Educational Set Scale (ESS). The interaction was investigated between one…

  13. an online model for assessing st for assessing st stepwise solving of ...

    African Journals Online (AJOL)

    User

    technologies in learning and teaching [9]. The use ... solving approach with the view to h learners realize the .... interactive enough as compared with when the lecture is been ... caused by poor pedagogy techniques. ... students through body language and voice ..... [9] Naidu, S. “E-Learning, a Guidebook of Principles,.

  14. Effectiveness of Computer-Assisted STAD Cooperative Learning Strategy on Physics Problem Solving, Achievement and Retention

    Science.gov (United States)

    Gambari, Amosa Isiaka; Yusuf, Mudasiru Olalere

    2015-01-01

    This study investigated the effectiveness of computer-assisted Students' Team Achievement Division (STAD) cooperative learning strategy on physics problem solving, students' achievement and retention. It also examined if the student performance would vary with gender. Purposive sampling technique was used to select two senior secondary schools…

  15. An Appropriate Prompts System Based on the Polya Method for Mathematical Problem-Solving

    Science.gov (United States)

    Lee, Chien I.

    2017-01-01

    Current mathematics education emphasizes techniques, formulas, and procedures, neglecting the importance of understanding, presentation, and reasoning. This turns students into passive listeners that are well-practiced only in using formulas that they do not understand. We therefore adopted the Polya problem-solving method to provide students with…

  16. A Computer Algebra Approach to Solving Chemical Equilibria in General Chemistry

    Science.gov (United States)

    Kalainoff, Melinda; Lachance, Russ; Riegner, Dawn; Biaglow, Andrew

    2012-01-01

    In this article, we report on a semester-long study of the incorporation into our general chemistry course, of advanced algebraic and computer algebra techniques for solving chemical equilibrium problems. The method presented here is an alternative to the commonly used concentration table method for describing chemical equilibria in general…

  17. Problem Solving Strategies of Selected Pre-Service Secondary School Mathematics Teachers in Malaysia

    Science.gov (United States)

    Yew, Wun Theam; Zamri, Sharifah Norul Akmar Syed

    2016-01-01

    Problem solving strategies of eight pre-service secondary school mathematics teachers (PSSMTs) were examined in this study. A case study research design was employed and clinical interview technique was used to collect the data. Materials collected for analysis consisted of audiotapes and videotapes of clinical interviews, subjects' notes and…

  18. Adapting a Problem-Solving Approach to Teaching Mathematics to Students with Mild Disabilities.

    Science.gov (United States)

    Salend, Spencer J.; Hofstetter, Elaine

    1996-01-01

    Guidelines for implementing a problem-solving approach to teaching mathematics concepts and skills to students with mild disabilities include: establish connections to daily life; use visual presentations; use manipulatives; use peer-mediated instruction; provide models, cues, and prompts; teach self-management techniques and learning strategies;…

  19. Application of NASA management approach to solve complex problems on earth

    Science.gov (United States)

    Potate, J. S.

    1972-01-01

    The application of NASA management approach to solving complex problems on earth is discussed. The management of the Apollo program is presented as an example of effective management techniques. Four key elements of effective management are analyzed. Photographs of the Cape Kennedy launch sites and supporting equipment are included to support the discussions.

  20. Effects of the SOLVE Strategy on the Mathematical Problem Solving Skills of Secondary Students with Learning Disabilities

    Science.gov (United States)

    Freeman-Green, Shaqwana M.; O'Brien, Chris; Wood, Charles L.; Hitt, Sara Beth

    2015-01-01

    This study examined the effects of explicit instruction in the SOLVE Strategy on the mathematical problem solving skills of six Grade 8 students with specific learning disabilities. The SOLVE Strategy is an explicit instruction, mnemonic-based learning strategy designed to help students in solving mathematical word problems. Using a multiple probe…