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Sample records for scale problem based

  1. A Large Scale Problem Based Learning inter-European Student Satellite Construction Project

    DEFF Research Database (Denmark)

    Nielsen, Jens Frederik Dalsgaard; Alminde, Lars; Bisgaard, Morten

    2006-01-01

    that electronic communication technology was vital within the project. Additionally the SSETI EXPRESS project implied the following problems it didn’t fit to a standard semester - 18 months for the satellite project compared to 5/6 months for a “normal” semester project. difficulties in integrating the tasks......A LARGE SCALE PROBLEM BASED LEARNING INTER-EUROPEAN STUDENT SATELLITE CONSTRUCTION PROJECT This paper describes the pedagogical outcome of a large scale PBL experiment. ESA (European Space Agency) Education Office launched January 2004 an ambitious project: Let students from all over Europe build....... The satellite was successfully launched on October 27th 2005 (http://www.express.space.aau.dk). The project was a student driven project with student project responsibility adding at lot of international experiences and project management skills to the outcome of more traditional one semester, single group...

  2. A Hamiltonian-based derivation of Scaled Boundary Finite Element Method for elasticity problems

    International Nuclear Information System (INIS)

    Hu Zhiqiang; Lin Gao; Wang Yi; Liu Jun

    2010-01-01

    The Scaled Boundary Finite Method (SBFEM) is a semi-analytical solution approach for solving partial differential equation. For problem in elasticity, the governing equations can be obtained by mechanically based formulation, Scaled-boundary-transformation-based formulation and principle of virtual work. The governing equations are described in the frame of Lagrange system and the unknowns are displacements. But in the solution procedure, the auxiliary variables are introduced and the equations are solved in the state space. Based on the observation that the duality system to solve elastic problem proposed by W.X. Zhong is similar to the above solution approach, the discretization of the SBFEM and the duality system are combined to derive the governing equations in the Hamilton system by introducing the dual variables in this paper. The Precise Integration Method (PIM) used in Duality system is also an efficient method for the solution of the governing equations of SBFEM in displacement and boundary stiffness matrix especially for the case which results some numerical difficulties in the usually uses the eigenvalue method. Numerical examples are used to demonstrate the validity and effectiveness of the PIM for solution of boundary static stiffness.

  3. A Framing Link Based Tabu Search Algorithm for Large-Scale Multidepot Vehicle Routing Problems

    Directory of Open Access Journals (Sweden)

    Xuhao Zhang

    2014-01-01

    Full Text Available A framing link (FL based tabu search algorithm is proposed in this paper for a large-scale multidepot vehicle routing problem (LSMDVRP. Framing links are generated during continuous great optimization of current solutions and then taken as skeletons so as to improve optimal seeking ability, speed up the process of optimization, and obtain better results. Based on the comparison between pre- and postmutation routes in the current solution, different parts are extracted. In the current optimization period, links involved in the optimal solution are regarded as candidates to the FL base. Multiple optimization periods exist in the whole algorithm, and there are several potential FLs in each period. If the update condition is satisfied, the FL base is updated, new FLs are added into the current route, and the next period starts. Through adjusting the borderline of multidepot sharing area with dynamic parameters, the authors define candidate selection principles for three kinds of customer connections, respectively. Link split and the roulette approach are employed to choose FLs. 18 LSMDVRP instances in three groups are studied and new optimal solution values for nine of them are obtained, with higher computation speed and reliability.

  4. A problem of scale

    International Nuclear Information System (INIS)

    Harrison, L.

    1991-01-01

    Small scale wind energy conversion is finding it even more difficult to realise its huge potential market than grid connected wind power. One of the main reasons for this is that its technical development is carried out in isolated parts of the world with little opportunity for technology transfer: small scale wind energy converters (SWECS) are not born of one technology, but have been evolved for different purposes; as a result, the SWECS community has no powerful lobbying force speaking with one voice to promote the technology. There are three distinct areas of application for SWECS, water pumping for domestic and livestock water supplies, irrigation, drainage etc., where no other mechanical means of power is available or viable, battery charging for lighting, TV, radio, and telecommunications in areas far from a grid or road system, and wind-diesel systems, mainly for use on islands where supply of diesel oil is possible, but costly. An attempt is being made to found an association to support the widespread implementation of SWECS and to promote their implementation. It is intended for Wind Energy for Rural Areas to have a permanent secretariat, based in Holland. (AB)

  5. A New Method Based On Modified Shuffled Frog Leaping Algorithm In Order To Solve Nonlinear Large Scale Problem

    Directory of Open Access Journals (Sweden)

    Aliasghar Baziar

    2015-03-01

    Full Text Available Abstract In order to handle large scale problems this study has used shuffled frog leaping algorithm. This algorithm is an optimization method based on natural memetics that uses a new two-phase modification to it to have a better search in the problem space. The suggested algorithm is evaluated by comparing to some well known algorithms using several benchmark optimization problems. The simulation results have clearly shown the superiority of this algorithm over other well-known methods in the area.

  6. A decomposition heuristics based on multi-bottleneck machines for large-scale job shop scheduling problems

    Directory of Open Access Journals (Sweden)

    Yingni Zhai

    2014-10-01

    Full Text Available Purpose: A decomposition heuristics based on multi-bottleneck machines for large-scale job shop scheduling problems (JSP is proposed.Design/methodology/approach: In the algorithm, a number of sub-problems are constructed by iteratively decomposing the large-scale JSP according to the process route of each job. And then the solution of the large-scale JSP can be obtained by iteratively solving the sub-problems. In order to improve the sub-problems' solving efficiency and the solution quality, a detection method for multi-bottleneck machines based on critical path is proposed. Therewith the unscheduled operations can be decomposed into bottleneck operations and non-bottleneck operations. According to the principle of “Bottleneck leads the performance of the whole manufacturing system” in TOC (Theory Of Constraints, the bottleneck operations are scheduled by genetic algorithm for high solution quality, and the non-bottleneck operations are scheduled by dispatching rules for the improvement of the solving efficiency.Findings: In the process of the sub-problems' construction, partial operations in the previous scheduled sub-problem are divided into the successive sub-problem for re-optimization. This strategy can improve the solution quality of the algorithm. In the process of solving the sub-problems, the strategy that evaluating the chromosome's fitness by predicting the global scheduling objective value can improve the solution quality.Research limitations/implications: In this research, there are some assumptions which reduce the complexity of the large-scale scheduling problem. They are as follows: The processing route of each job is predetermined, and the processing time of each operation is fixed. There is no machine breakdown, and no preemption of the operations is allowed. The assumptions should be considered if the algorithm is used in the actual job shop.Originality/value: The research provides an efficient scheduling method for the

  7. Particle-based simulation of charge transport in discrete-charge nano-scale systems: the electrostatic problem.

    Science.gov (United States)

    Berti, Claudio; Gillespie, Dirk; Eisenberg, Robert S; Fiegna, Claudio

    2012-02-16

    The fast and accurate computation of the electric forces that drive the motion of charged particles at the nanometer scale represents a computational challenge. For this kind of system, where the discrete nature of the charges cannot be neglected, boundary element methods (BEM) represent a better approach than finite differences/finite elements methods. In this article, we compare two different BEM approaches to a canonical electrostatic problem in a three-dimensional space with inhomogeneous dielectrics, emphasizing their suitability for particle-based simulations: the iterative method proposed by Hoyles et al. and the Induced Charge Computation introduced by Boda et al.

  8. Enhancing students' learning in problem based learning: validation of a self-assessment scale for active learning and critical thinking.

    Science.gov (United States)

    Khoiriyah, Umatul; Roberts, Chris; Jorm, Christine; Van der Vleuten, C P M

    2015-08-26

    Problem based learning (PBL) is a powerful learning activity but fidelity to intended models may slip and student engagement wane, negatively impacting learning processes, and outcomes. One potential solution to solve this degradation is by encouraging self-assessment in the PBL tutorial. Self-assessment is a central component of the self-regulation of student learning behaviours. There are few measures to investigate self-assessment relevant to PBL processes. We developed a Self-assessment Scale on Active Learning and Critical Thinking (SSACT) to address this gap. We wished to demonstrated evidence of its validity in the context of PBL by exploring its internal structure. We used a mixed methods approach to scale development. We developed scale items from a qualitative investigation, literature review, and consideration of previous existing tools used for study of the PBL process. Expert review panels evaluated its content; a process of validation subsequently reduced the pool of items. We used structural equation modelling to undertake a confirmatory factor analysis (CFA) of the SSACT and coefficient alpha. The 14 item SSACT consisted of two domains "active learning" and "critical thinking." The factorial validity of SSACT was evidenced by all items loading significantly on their expected factors, a good model fit for the data, and good stability across two independent samples. Each subscale had good internal reliability (>0.8) and strongly correlated with each other. The SSACT has sufficient evidence of its validity to support its use in the PBL process to encourage students to self-assess. The implementation of the SSACT may assist students to improve the quality of their learning in achieving PBL goals such as critical thinking and self-directed learning.

  9. Particle-based simulation of charge transport in discrete-charge nano-scale systems: the electrostatic problem

    OpenAIRE

    Berti, Claudio; Gillespie, Dirk; Eisenberg, Robert S; Fiegna, Claudio

    2012-01-01

    The fast and accurate computation of the electric forces that drive the motion of charged particles at the nanometer scale represents a computational challenge. For this kind of system, where the discrete nature of the charges cannot be neglected, boundary element methods (BEM) represent a better approach than finite differences/finite elements methods. In this article, we compare two different BEM approaches to a canonical electrostatic problem in a three-dimensional space with inhomogeneous...

  10. Enhancing students' learning in problem based learning: validation of a self-assessment scale for active learning and critical thinking

    NARCIS (Netherlands)

    Khoiriyah, U.; Roberts, C.; Jorm, C.; Vleuten, C.P. van der

    2015-01-01

    BACKGROUND: Problem based learning (PBL) is a powerful learning activity but fidelity to intended models may slip and student engagement wane, negatively impacting learning processes, and outcomes. One potential solution to solve this degradation is by encouraging self-assessment in the PBL

  11. A solution approach based on Benders decomposition for the preventive maintenance scheduling problem of a stochastic large-scale energy system

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Muller, Laurent Flindt; Petersen, Bjørn

    2013-01-01

    This paper describes a Benders decomposition-based framework for solving the large scale energy management problem that was posed for the ROADEF 2010 challenge. The problem was taken from the power industry and entailed scheduling the outage dates for a set of nuclear power plants, which need...... to be regularly taken down for refueling and maintenance, in such away that the expected cost of meeting the power demand in a number of potential scenarios is minimized. We show that the problem structure naturally lends itself to Benders decomposition; however, not all constraints can be included in the mixed...

  12. The scale of the problem

    International Nuclear Information System (INIS)

    Stopford, J.

    2001-01-01

    The Social Impact of the closure of ChNPP is indeed a significant and complex one. There is no one simple solution to the problem but if the effects of closure are to be mitigated effectively all who are involved, be they part of the local community, donor agencies or project staff need to work together towards the common goal, putting aside personal agendas and ensuring that every resource, financial and human, is used in a productive and constructive way complementing the activities of others and not competing with them

  13. Monte Carlo simulation methods in moment-based scale-bridging algorithms for thermal radiative-transfer problems

    International Nuclear Information System (INIS)

    Densmore, J.D.; Park, H.; Wollaber, A.B.; Rauenzahn, R.M.; Knoll, D.A.

    2015-01-01

    We present a moment-based acceleration algorithm applied to Monte Carlo simulation of thermal radiative-transfer problems. Our acceleration algorithm employs a continuum system of moments to accelerate convergence of stiff absorption–emission physics. The combination of energy-conserving tallies and the use of an asymptotic approximation in optically thick regions remedy the difficulties of local energy conservation and mitigation of statistical noise in such regions. We demonstrate the efficiency and accuracy of the developed method. We also compare directly to the standard linearization-based method of Fleck and Cummings [1]. A factor of 40 reduction in total computational time is achieved with the new algorithm for an equivalent (or more accurate) solution as compared with the Fleck–Cummings algorithm

  14. Monte Carlo simulation methods in moment-based scale-bridging algorithms for thermal radiative-transfer problems

    Energy Technology Data Exchange (ETDEWEB)

    Densmore, J.D., E-mail: jeffery.densmore@unnpp.gov [Bettis Atomic Power Laboratory, P.O. Box 79, West Mifflin, PA 15122 (United States); Park, H., E-mail: hkpark@lanl.gov [Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory, P.O. Box 1663, MS B216, Los Alamos, NM 87545 (United States); Wollaber, A.B., E-mail: wollaber@lanl.gov [Computational Physics and Methods Group, Los Alamos National Laboratory, P.O. Box 1663, MS D409, Los Alamos, NM 87545 (United States); Rauenzahn, R.M., E-mail: rick@lanl.gov [Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory, P.O. Box 1663, MS B216, Los Alamos, NM 87545 (United States); Knoll, D.A., E-mail: nol@lanl.gov [Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory, P.O. Box 1663, MS B216, Los Alamos, NM 87545 (United States)

    2015-03-01

    We present a moment-based acceleration algorithm applied to Monte Carlo simulation of thermal radiative-transfer problems. Our acceleration algorithm employs a continuum system of moments to accelerate convergence of stiff absorption–emission physics. The combination of energy-conserving tallies and the use of an asymptotic approximation in optically thick regions remedy the difficulties of local energy conservation and mitigation of statistical noise in such regions. We demonstrate the efficiency and accuracy of the developed method. We also compare directly to the standard linearization-based method of Fleck and Cummings [1]. A factor of 40 reduction in total computational time is achieved with the new algorithm for an equivalent (or more accurate) solution as compared with the Fleck–Cummings algorithm.

  15. Some Problems of Industrial Scale-Up.

    Science.gov (United States)

    Jackson, A. T.

    1985-01-01

    Scientific ideas of the biological laboratory are turned into economic realities in industry only after several problems are solved. Economics of scale, agitation, heat transfer, sterilization of medium and air, product recovery, waste disposal, and future developments are discussed using aerobic respiration as the example in the scale-up…

  16. Scaling of Attitudes Toward Population Problems

    Science.gov (United States)

    Watkins, George A.

    1975-01-01

    This study related population problem attitudes and socioeconomic variables. Six items concerned with number of children, birth control, family, science, economic depression, and overpopulation were selected for a Guttman scalogram. Education, occupation, and number of children were correlated with population problems scale scores; marital status,…

  17. Sensitivity analysis for large-scale problems

    Science.gov (United States)

    Noor, Ahmed K.; Whitworth, Sandra L.

    1987-01-01

    The development of efficient techniques for calculating sensitivity derivatives is studied. The objective is to present a computational procedure for calculating sensitivity derivatives as part of performing structural reanalysis for large-scale problems. The scope is limited to framed type structures. Both linear static analysis and free-vibration eigenvalue problems are considered.

  18. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

  19. Problem Based Game Design

    DEFF Research Database (Denmark)

    Reng, Lars; Schoenau-Fog, Henrik

    2011-01-01

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

  20. Problem-based learning

    NARCIS (Netherlands)

    Loyens, Sofie; Kirschner, Paul A.; Paas, Fred

    2010-01-01

    Loyens, S. M. M., Kirschner, P. A., & Paas, F. (2011). Problem-based learning. In S. Graham (Editor-in-Chief), A. Bus, S. Major, & L. Swanson (Associate Editors), APA educational psychology handbook: Vol. 3. Application to learning and teaching (pp. 403-425). Washington, DC: American Psychological

  1. Association of Stressful Life Events with Psychological Problems: A Large-Scale Community-Based Study Using Grouped Outcomes Latent Factor Regression with Latent Predictors

    Directory of Open Access Journals (Sweden)

    Akbar Hassanzadeh

    2017-01-01

    Full Text Available Objective. The current study is aimed at investigating the association between stressful life events and psychological problems in a large sample of Iranian adults. Method. In a cross-sectional large-scale community-based study, 4763 Iranian adults, living in Isfahan, Iran, were investigated. Grouped outcomes latent factor regression on latent predictors was used for modeling the association of psychological problems (depression, anxiety, and psychological distress, measured by Hospital Anxiety and Depression Scale (HADS and General Health Questionnaire (GHQ-12, as the grouped outcomes, and stressful life events, measured by a self-administered stressful life events (SLEs questionnaire, as the latent predictors. Results. The results showed that the personal stressors domain has significant positive association with psychological distress (β=0.19, anxiety (β=0.25, depression (β=0.15, and their collective profile score (β=0.20, with greater associations in females (β=0.28 than in males (β=0.13 (all P<0.001. In addition, in the adjusted models, the regression coefficients for the association of social stressors domain and psychological problems profile score were 0.37, 0.35, and 0.46 in total sample, males, and females, respectively (P<0.001. Conclusion. Results of our study indicated that different stressors, particularly those socioeconomic related, have an effective impact on psychological problems. It is important to consider the social and cultural background of a population for managing the stressors as an effective approach for preventing and reducing the destructive burden of psychological problems.

  2. Association of Stressful Life Events with Psychological Problems: A Large-Scale Community-Based Study Using Grouped Outcomes Latent Factor Regression with Latent Predictors

    Science.gov (United States)

    Hassanzadeh, Akbar; Heidari, Zahra; Hassanzadeh Keshteli, Ammar; Afshar, Hamid

    2017-01-01

    Objective The current study is aimed at investigating the association between stressful life events and psychological problems in a large sample of Iranian adults. Method In a cross-sectional large-scale community-based study, 4763 Iranian adults, living in Isfahan, Iran, were investigated. Grouped outcomes latent factor regression on latent predictors was used for modeling the association of psychological problems (depression, anxiety, and psychological distress), measured by Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (GHQ-12), as the grouped outcomes, and stressful life events, measured by a self-administered stressful life events (SLEs) questionnaire, as the latent predictors. Results The results showed that the personal stressors domain has significant positive association with psychological distress (β = 0.19), anxiety (β = 0.25), depression (β = 0.15), and their collective profile score (β = 0.20), with greater associations in females (β = 0.28) than in males (β = 0.13) (all P < 0.001). In addition, in the adjusted models, the regression coefficients for the association of social stressors domain and psychological problems profile score were 0.37, 0.35, and 0.46 in total sample, males, and females, respectively (P < 0.001). Conclusion Results of our study indicated that different stressors, particularly those socioeconomic related, have an effective impact on psychological problems. It is important to consider the social and cultural background of a population for managing the stressors as an effective approach for preventing and reducing the destructive burden of psychological problems. PMID:29312459

  3. Stabilization Algorithms for Large-Scale Problems

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg

    2006-01-01

    The focus of the project is on stabilization of large-scale inverse problems where structured models and iterative algorithms are necessary for computing approximate solutions. For this purpose, we study various iterative Krylov methods and their abilities to produce regularized solutions. Some......-curve. This heuristic is implemented as a part of a larger algorithm which is developed in collaboration with G. Rodriguez and P. C. Hansen. Last, but not least, a large part of the project has, in different ways, revolved around the object-oriented Matlab toolbox MOORe Tools developed by PhD Michael Jacobsen. New...

  4. Solving Large Scale Crew Scheduling Problems in Practice

    NARCIS (Netherlands)

    E.J.W. Abbink (Erwin); L. Albino; T.A.B. Dollevoet (Twan); D. Huisman (Dennis); J. Roussado; R.L. Saldanha

    2010-01-01

    textabstractThis paper deals with large-scale crew scheduling problems arising at the Dutch railway operator, Netherlands Railways (NS). NS operates about 30,000 trains a week. All these trains need a driver and a certain number of guards. Some labor rules restrict the duties of a certain crew base

  5. Bonus algorithm for large scale stochastic nonlinear programming problems

    CERN Document Server

    Diwekar, Urmila

    2015-01-01

    This book presents the details of the BONUS algorithm and its real world applications in areas like sensor placement in large scale drinking water networks, sensor placement in advanced power systems, water management in power systems, and capacity expansion of energy systems. A generalized method for stochastic nonlinear programming based on a sampling based approach for uncertainty analysis and statistical reweighting to obtain probability information is demonstrated in this book. Stochastic optimization problems are difficult to solve since they involve dealing with optimization and uncertainty loops. There are two fundamental approaches used to solve such problems. The first being the decomposition techniques and the second method identifies problem specific structures and transforms the problem into a deterministic nonlinear programming problem. These techniques have significant limitations on either the objective function type or the underlying distributions for the uncertain variables. Moreover, these ...

  6. Dimensions of problem based learning

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Andreasen, Lars Birch

    2013-01-01

    The article contributes to the literature on problem based learning and problem-oriented project work, building on and reflecting the experiences of the authors through decades of work with problem-oriented project pedagogy. The article explores different dimensions of problem based learning such...... and Learning (MIL). We discuss changes in the roles of the teachers as supervisors within this learning environment, and we explore the involvement of students as active participants and co-designers of how course and project activities unfold....

  7. 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…

  8. SPACE BASED INTERCEPTOR SCALING

    Energy Technology Data Exchange (ETDEWEB)

    G. CANAVAN

    2001-02-01

    Space Based Interceptor (SBI) have ranges that are adequate to address rogue ICBMs. They are not overly sensitive to 30-60 s delay times. Current technologies would support boost phase intercept with about 150 interceptors. Higher acceleration and velocity could reduce than number by about a factor of 3 at the cost of heavier and more expensive Kinetic Kill Vehicles (KKVs). 6g SBI would reduce optimal constellation costs by about 35%; 8g SBI would reduce them another 20%. Interceptor ranges fall rapidly with theater missile range. Constellations increase significantly for ranges under 3,000 km, even with advanced interceptor technology. For distributed launches, these estimates recover earlier strategic scalings, which demonstrate the improved absentee ratio for larger or multiple launch areas. Constellations increase with the number of missiles and the number of interceptors launched at each. The economic estimates above suggest that two SBI per missile with a modest midcourse underlay is appropriate. The SBI KKV technology would appear to be common for space- and surface-based boost phase systems, and could have synergisms with improved midcourse intercept and discrimination systems. While advanced technology could be helpful in reducing costs, particularly for short range theater missiles, current technology appears adequate for pressing rogue ICBM, accidental, and unauthorized launches.

  9. Homogenization-based interval analysis for structural-acoustic problem involving periodical composites and multi-scale uncertain-but-bounded parameters.

    Science.gov (United States)

    Chen, Ning; Yu, Dejie; Xia, Baizhan; Liu, Jian; Ma, Zhengdong

    2017-04-01

    This paper presents a homogenization-based interval analysis method for the prediction of coupled structural-acoustic systems involving periodical composites and multi-scale uncertain-but-bounded parameters. In the structural-acoustic system, the macro plate structure is assumed to be composed of a periodically uniform microstructure. The equivalent macro material properties of the microstructure are computed using the homogenization method. By integrating the first-order Taylor expansion interval analysis method with the homogenization-based finite element method, a homogenization-based interval finite element method (HIFEM) is developed to solve a periodical composite structural-acoustic system with multi-scale uncertain-but-bounded parameters. The corresponding formulations of the HIFEM are deduced. A subinterval technique is also introduced into the HIFEM for higher accuracy. Numerical examples of a hexahedral box and an automobile passenger compartment are given to demonstrate the efficiency of the presented method for a periodical composite structural-acoustic system with multi-scale uncertain-but-bounded parameters.

  10. K-State Problem Identification Rating Scales for College Students

    Science.gov (United States)

    Robertson, John M.; Benton, Stephen L.; Newton, Fred B.; Downey, Ronald G.; Marsh, Patricia A.; Benton, Sheryl A.; Tseng, Wen-Chih; Shin, Kang-Hyun

    2006-01-01

    The K-State Problem Identification Rating Scales, a new screening instrument for college counseling centers, gathers information about clients' presenting symptoms, functioning levels, and readiness to change. Three studies revealed 7 scales: Mood Difficulties, Learning Problems, Food Concerns, Interpersonal Conflicts, Career Uncertainties,…

  11. Small Scale Variability and the Problem of Data Validation

    Science.gov (United States)

    Sparling, L. C.; Avallone, L.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Numerous measurements taken with a variety of airborne, balloon borne and ground based instruments over the past decade have revealed a complex multiscaled 3D structure in both chemical and dynamical fields in the upper troposphere/lower stratosphere. The variability occurs on scales that are well below the resolution of satellite measurements, leading to problems in measurement validation. We discuss some statistical ideas that can shed some light on the contribution of the natural variability to the inevitable differences in correlative measurements that are not strictly colocated, or that have different spatial resolution.

  12. The problem of scale in planetary geomorphology

    Science.gov (United States)

    Rossbacher, L. A.

    1985-01-01

    Recent planetary exploration has shown that specific landforms exhibit a significant range in size between planets. Similar features on Earth and Mars offer some of the best examples of this scale difference. The difference in heights of volcanic features between the two planets has been cited often; the Martian volcano Olympus Mons stands approximately 26 km high, but Mauna Loa rises only 11 km above the Pacific Ocean floor. Polygonally fractured ground in the northern plains of Mars has diameters up to 20 km across; the largest terrestrial polygons are only 500 m in diameter. Mars also has landslides, aeolian features, and apparent rift valleys larger than any known on Earth. No single factor can explain the variations in landform size between planets. Controls on variation on Earth, related to climate, lithology, or elevation, have seldom been considered in detail. The size differences between features on Earth and other planets seem to be caused by a complex group of interacting relationships. The major planetary parameters that may affect landform size are discussed.

  13. Java problem-based learning

    Directory of Open Access Journals (Sweden)

    Goran P, Šimić

    2012-01-01

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

  14. Topology Optimization of Large Scale Stokes Flow Problems

    DEFF Research Database (Denmark)

    Aage, Niels; Poulsen, Thomas Harpsøe; Gersborg-Hansen, Allan

    2008-01-01

    This note considers topology optimization of large scale 2D and 3D Stokes flow problems using parallel computations. We solve problems with up to 1.125.000 elements in 2D and 128.000 elements in 3D on a shared memory computer consisting of Sun UltraSparc IV CPUs.......This note considers topology optimization of large scale 2D and 3D Stokes flow problems using parallel computations. We solve problems with up to 1.125.000 elements in 2D and 128.000 elements in 3D on a shared memory computer consisting of Sun UltraSparc IV CPUs....

  15. Scaling and uncertainty in BWR instability problems

    International Nuclear Information System (INIS)

    Di Auria, F.; Pellicoro, V.

    1995-01-01

    This paper deals with a critical review of activities, performed at the DCMN of Pisa University, in relation to the thermo-hydraulic oscillations in two-phase systems. Stability analyses, including model development and achievement of experimental data, are generally performed for BWRs in order to achieve the following objectives: to reach a common understanding in relation to the predictive capabilities of system codes and to the influence of various parameters on the instability; to establish a data base for the qualification of the analytical tools already or becoming available; to set-up qualified tools (code/models + nodalization + user assumption) suitable for predicting the unstable behaviour of the nuclear plants of interest (current BWR, SBWR, ABWR and RBMK). These considerations have been the basis for the following researches: 1) proposal of the Boiling Instability Program (BIP) (1) 2) evaluation of stability tests in PIPER-ONE apparatus (2) 3) coupled thermal-hydraulic and neutronic instabilities in the LaSalle-2 BWR plant (3) 4) participation to the NEA-OECD BWR Benchmark (4) The RELAP/MOD2 and RELAP5/MOD3 codes have been used. (author)

  16. Local supersymmetry and the problem of the mass scales

    International Nuclear Information System (INIS)

    Nilles, H.P.

    1983-02-01

    Spontaneously broken supergravity might help us to understand the puzzle of the mass scales in grand unified models. We describe the general mechanism and point out the remaining problems. Some new results on local supercolor are presented

  17. Discussion of several problems in nuclear instrument scale

    International Nuclear Information System (INIS)

    Li Xuezhen; Zhou Sichun; Xiao Caijin

    2005-01-01

    The equipment scale is the first problem in measurement, including nuclear apparatus, otherwise there are different methods of equipment scale, then how to get the best way to seek the scale equation is the keystone of study. The article discusses several methods to get scale equation from the angle of error transformation, and compares their superiority, then gets the most precision method--Deming method, in addition, there is another simple and applied method, that is method of the mean, in the end, validates the theory through X fluorescence equipment scale. (authors)

  18. Problem Based Learning for engineering.

    Science.gov (United States)

    Kumar, Dinesh; Radcliffe, Pj

    2017-07-01

    the role of Problem Based Learning (PBL) is relative clear in domains such as medicine but its efficacy in engineering is as yet less certain. To clarify the role of PBL in engineering, a 3 day workshop was conducted for senior Brazilian engineering academics where they were given the theory and then an immersive PBL experience. One major purpose for running this workshop was for them to identify suitable courses where PBL could be considered. During this workshop, they were split in teams and given a diverse range of problems. At the conclusion of the workshop, a quantifiable survey was conducted and the results show that PBL can deliver superior educational outcomes providing the student group is drawn from the top 5% of the year 12 students, and that significantly higher resources are made available. Thus, any proposed PBL program in engineering must be able to demonstrate that it can meet these requirements before it can move forward to implementation.

  19. Problems of large-scale vertically-integrated aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Webber, H H; Riordan, P F

    1976-01-01

    The problems of vertically-integrated aquaculture are outlined; they are concerned with: species limitations (in the market, biological and technological); site selection, feed, manpower needs, and legal, institutional and financial requirements. The gaps in understanding of, and the constraints limiting, large-scale aquaculture are listed. Future action is recommended with respect to: types and diversity of species to be cultivated, marketing, biotechnology (seed supply, disease control, water quality and concerted effort), siting, feed, manpower, legal and institutional aids (granting of water rights, grants, tax breaks, duty-free imports, etc.), and adequate financing. The last of hard data based on experience suggests that large-scale vertically-integrated aquaculture is a high risk enterprise, and with the high capital investment required, banks and funding institutions are wary of supporting it. Investment in pilot projects is suggested to demonstrate that large-scale aquaculture can be a fully functional and successful business. Construction and operation of such pilot farms is judged to be in the interests of both the public and private sector.

  20. Using Problem-Based Learning in Accounting

    Science.gov (United States)

    Hansen, James D.

    2006-01-01

    In this article, the author describes the process of writing a problem-based learning (PBL) problem and shows how a typical end-of-chapter accounting problem can be converted to a PBL problem. PBL uses complex, real-world problems to motivate students to identify and research the concepts and principles they need to know to solve these problems.…

  1. Implicit solvers for large-scale nonlinear problems

    International Nuclear Information System (INIS)

    Keyes, David E; Reynolds, Daniel R; Woodward, Carol S

    2006-01-01

    Computational scientists are grappling with increasingly complex, multi-rate applications that couple such physical phenomena as fluid dynamics, electromagnetics, radiation transport, chemical and nuclear reactions, and wave and material propagation in inhomogeneous media. Parallel computers with large storage capacities are paving the way for high-resolution simulations of coupled problems; however, hardware improvements alone will not prove enough to enable simulations based on brute-force algorithmic approaches. To accurately capture nonlinear couplings between dynamically relevant phenomena, often while stepping over rapid adjustments to quasi-equilibria, simulation scientists are increasingly turning to implicit formulations that require a discrete nonlinear system to be solved for each time step or steady state solution. Recent advances in iterative methods have made fully implicit formulations a viable option for solution of these large-scale problems. In this paper, we overview one of the most effective iterative methods, Newton-Krylov, for nonlinear systems and point to software packages with its implementation. We illustrate the method with an example from magnetically confined plasma fusion and briefly survey other areas in which implicit methods have bestowed important advantages, such as allowing high-order temporal integration and providing a pathway to sensitivity analyses and optimization. Lastly, we overview algorithm extensions under development motivated by current SciDAC applications

  2. Analysis of mathematical problem-solving ability based on metacognition on problem-based learning

    Science.gov (United States)

    Mulyono; Hadiyanti, R.

    2018-03-01

    Problem-solving is the primary purpose of the mathematics curriculum. Problem-solving abilities influenced beliefs and metacognition. Metacognition as superordinate capabilities can direct, regulate cognition and motivation and then problem-solving processes. This study aims to (1) test and analyzes the quality of problem-based learning and (2) investigate the problem-solving capabilities based on metacognition. This research uses mixed method study with The subject research are class XI students of Mathematics and Science at High School Kesatrian 2 Semarang which divided into tacit use, aware use, strategic use and reflective use level. The collecting data using scale, interviews, and tests. The data processed with the proportion of test, t-test, and paired samples t-test. The result shows that the students with levels tacit use were able to complete the whole matter given, but do not understand what and why a strategy is used. Students with aware use level were able to solve the problem, be able to build new knowledge through problem-solving to the indicators, understand the problem, determine the strategies used, although not right. Students on the Strategic ladder Use can be applied and adopt a wide variety of appropriate strategies to solve the issues and achieved re-examine indicators of process and outcome. The student with reflective use level is not found in this study. Based on the results suggested that study about the identification of metacognition in problem-solving so that the characteristics of each level of metacognition more clearly in a more significant sampling. Teachers need to know in depth about the student metacognitive activity and its relationship with mathematical problem solving and another problem resolution.

  3. Dressed skeleton expansion and the coupling scale ambiguity problem

    International Nuclear Information System (INIS)

    Lu, Hung Jung.

    1992-09-01

    Perturbative expansions in quantum field theories are usually expressed in powers of a coupling constant. In principle, the infinite sum of the expansion series is independent of the renormalization scale of the coupling constant. In practice, there is a remnant dependence of the truncated series on the renormalization scale. This scale ambiguity can severely restrict the predictive power of theoretical calculations. The dressed skeleton expansion is developed as a calculational method which avoids the coupling scale ambiguity problem. In this method, physical quantities are expressed as functional expansions in terms of a coupling vertex function. The arguments of the vertex function are given by the physical momenta of each process. These physical momenta effectively replace the unspecified renormalization scale and eliminate the ambiguity problem. This method is applied to various field theoretical models and its main features and limitations are explored. For quantum chromodynamics, an expression for the running coupling constant of the three-gluon vertex is obtained. The effective coupling scale of this vertex is shown to be essentially given by μ 2 ∼ Q min 2 Q med 2 /Q max 2 where Q min 2 Q med 2 /Q max 2 are respectively the smallest, the next-to-smallest and the largest scale among the three gluon virtualities. This functional form suggests that the three-gluon vertex becomes non-perturbative at asymmetric momentum configurations. Implications for four-jet physics is discussed

  4. Problems of allometric scaling analysis : Examples from mammalian reproductive biology

    NARCIS (Netherlands)

    Martin, RD; Genoud, M; Hemelrijk, CK

    Biological scaling analyses employing the widely used bivariate allometric model are beset by at least four interacting problems: (1) choice of an appropriate best-fit line with due attention to the influence of outliers; (2) objective recognition of divergent subsets in the data (allometric

  5. Scale problems in assessment of hydrogeological parameters of groundwater flow models

    Science.gov (United States)

    Nawalany, Marek; Sinicyn, Grzegorz

    2015-09-01

    An overview is presented of scale problems in groundwater flow, with emphasis on upscaling of hydraulic conductivity, being a brief summary of the conventional upscaling approach with some attention paid to recently emerged approaches. The focus is on essential aspects which may be an advantage in comparison to the occasionally extremely extensive summaries presented in the literature. In the present paper the concept of scale is introduced as an indispensable part of system analysis applied to hydrogeology. The concept is illustrated with a simple hydrogeological system for which definitions of four major ingredients of scale are presented: (i) spatial extent and geometry of hydrogeological system, (ii) spatial continuity and granularity of both natural and man-made objects within the system, (iii) duration of the system and (iv) continuity/granularity of natural and man-related variables of groundwater flow system. Scales used in hydrogeology are categorised into five classes: micro-scale - scale of pores, meso-scale - scale of laboratory sample, macro-scale - scale of typical blocks in numerical models of groundwater flow, local-scale - scale of an aquifer/aquitard and regional-scale - scale of series of aquifers and aquitards. Variables, parameters and groundwater flow equations for the three lowest scales, i.e., pore-scale, sample-scale and (numerical) block-scale, are discussed in detail, with the aim to justify physically deterministic procedures of upscaling from finer to coarser scales (stochastic issues of upscaling are not discussed here). Since the procedure of transition from sample-scale to block-scale is physically well based, it is a good candidate for upscaling block-scale models to local-scale models and likewise for upscaling local-scale models to regional-scale models. Also the latest results in downscaling from block-scale to sample scale are briefly referred to.

  6. Scale problems in assessment of hydrogeological parameters of groundwater flow models

    Directory of Open Access Journals (Sweden)

    Nawalany Marek

    2015-09-01

    Full Text Available An overview is presented of scale problems in groundwater flow, with emphasis on upscaling of hydraulic conductivity, being a brief summary of the conventional upscaling approach with some attention paid to recently emerged approaches. The focus is on essential aspects which may be an advantage in comparison to the occasionally extremely extensive summaries presented in the literature. In the present paper the concept of scale is introduced as an indispensable part of system analysis applied to hydrogeology. The concept is illustrated with a simple hydrogeological system for which definitions of four major ingredients of scale are presented: (i spatial extent and geometry of hydrogeological system, (ii spatial continuity and granularity of both natural and man-made objects within the system, (iii duration of the system and (iv continuity/granularity of natural and man-related variables of groundwater flow system. Scales used in hydrogeology are categorised into five classes: micro-scalescale of pores, meso-scalescale of laboratory sample, macro-scalescale of typical blocks in numerical models of groundwater flow, local-scalescale of an aquifer/aquitard and regional-scalescale of series of aquifers and aquitards. Variables, parameters and groundwater flow equations for the three lowest scales, i.e., pore-scale, sample-scale and (numerical block-scale, are discussed in detail, with the aim to justify physically deterministic procedures of upscaling from finer to coarser scales (stochastic issues of upscaling are not discussed here. Since the procedure of transition from sample-scale to block-scale is physically well based, it is a good candidate for upscaling block-scale models to local-scale models and likewise for upscaling local-scale models to regional-scale models. Also the latest results in downscaling from block-scale to sample scale are briefly referred to.

  7. Features and Characteristics of Problem Based Learning

    Science.gov (United States)

    Ceker, Eser; Ozdamli, Fezile

    2016-01-01

    Throughout the years, there appears to be an increase in Problem Based Learning applications in education; and Problem Based Learning related research areas. The main aim of this research is to underline the fundamentals (basic elements) of Problem Based Learning, investigate the dimensions of research approached to PBL oriented areas (with a look…

  8. Nonlinear triple-point problems on time scales

    Directory of Open Access Journals (Sweden)

    Douglas R. Anderson

    2004-04-01

    Full Text Available We establish the existence of multiple positive solutions to the nonlinear second-order triple-point boundary-value problem on time scales, $$displaylines{ u^{Delta abla}(t+h(tf(t,u(t=0, cr u(a=alpha u(b+delta u^Delta(a,quad eta u(c+gamma u^Delta(c=0 }$$ for $tin[a,c]subsetmathbb{T}$, where $mathbb{T}$ is a time scale, $eta, gamma, deltage 0$ with $Beta+gamma>0$, $0

  9. The renormalization scale-setting problem in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xing-Gang [Chongqing Univ. (China); Brodsky, Stanley J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Mojaza, Matin [SLAC National Accelerator Lab., Menlo Park, CA (United States); Univ. of Southern Denmark, Odense (Denmark)

    2013-09-01

    A key problem in making precise perturbative QCD predictions is to set the proper renormalization scale of the running coupling. The conventional scale-setting procedure assigns an arbitrary range and an arbitrary systematic error to fixed-order pQCD predictions. In fact, this ad hoc procedure gives results which depend on the choice of the renormalization scheme, and it is in conflict with the standard scale-setting procedure used in QED. Predictions for physical results should be independent of the choice of the scheme or other theoretical conventions. We review current ideas and points of view on how to deal with the renormalization scale ambiguity and show how to obtain renormalization scheme- and scale-independent estimates. We begin by introducing the renormalization group (RG) equation and an extended version, which expresses the invariance of physical observables under both the renormalization scheme and scale-parameter transformations. The RG equation provides a convenient way for estimating the scheme- and scale-dependence of a physical process. We then discuss self-consistency requirements of the RG equations, such as reflexivity, symmetry, and transitivity, which must be satisfied by a scale-setting method. Four typical scale setting methods suggested in the literature, i.e., the Fastest Apparent Convergence (FAC) criterion, the Principle of Minimum Sensitivity (PMS), the Brodsky–Lepage–Mackenzie method (BLM), and the Principle of Maximum Conformality (PMC), are introduced. Basic properties and their applications are discussed. We pay particular attention to the PMC, which satisfies all of the requirements of RG invariance. Using the PMC, all non-conformal terms associated with the β-function in the perturbative series are summed into the running coupling, and one obtains a unique, scale-fixed, scheme-independent prediction at any finite order. The PMC provides the principle underlying the BLM method, since it gives the general rule for extending

  10. Problems of allometric scaling analysis: examples from mammalian reproductive biology.

    Science.gov (United States)

    Martin, Robert D; Genoud, Michel; Hemelrijk, Charlotte K

    2005-05-01

    Biological scaling analyses employing the widely used bivariate allometric model are beset by at least four interacting problems: (1) choice of an appropriate best-fit line with due attention to the influence of outliers; (2) objective recognition of divergent subsets in the data (allometric grades); (3) potential restrictions on statistical independence resulting from phylogenetic inertia; and (4) the need for extreme caution in inferring causation from correlation. A new non-parametric line-fitting technique has been developed that eliminates requirements for normality of distribution, greatly reduces the influence of outliers and permits objective recognition of grade shifts in substantial datasets. This technique is applied in scaling analyses of mammalian gestation periods and of neonatal body mass in primates. These analyses feed into a re-examination, conducted with partial correlation analysis, of the maternal energy hypothesis relating to mammalian brain evolution, which suggests links between body size and brain size in neonates and adults, gestation period and basal metabolic rate. Much has been made of the potential problem of phylogenetic inertia as a confounding factor in scaling analyses. However, this problem may be less severe than suspected earlier because nested analyses of variance conducted on residual variation (rather than on raw values) reveals that there is considerable variance at low taxonomic levels. In fact, limited divergence in body size between closely related species is one of the prime examples of phylogenetic inertia. One common approach to eliminating perceived problems of phylogenetic inertia in allometric analyses has been calculation of 'independent contrast values'. It is demonstrated that the reasoning behind this approach is flawed in several ways. Calculation of contrast values for closely related species of similar body size is, in fact, highly questionable, particularly when there are major deviations from the best

  11. Characteristics of Problem-Based Learning

    DEFF Research Database (Denmark)

    Kolmos, Anette

    2003-01-01

    Problem BAsed LEarning (PBL) is widely regarded as a successful and innovative method for engineering education. The article highlights the Dutch approach of directing the learning process throuogh problem analysis and the Danish model of project-organised learning...

  12. Features and characteristics of problem based learning

    Directory of Open Access Journals (Sweden)

    Eser Ceker

    2016-12-01

    Full Text Available Throughout the years, there appears to be an increase in Problem Based Learning applications in education; and Problem Based Learning related research areas. The main aim of this research is to underline the fundamentals (basic elements of Problem Based Learning, investigate the dimensions of research approached to PBL oriented areas (with a look for the latest technology supported tools of Problem Based Learning. This research showed that the most researched characteristics of PBL are; teacher and student assessments on Problem Based Learning, Variety of disciplines in which Problem Based Learning strategies were tried and success evaluated, Using Problem Based Learning alone or with other strategies (Hybrid or Mix methods, Comparing Problem Based Learning with other strategies, and new trends and tendencies in Problem Based Learning related research. Our research may help us to identify the latest trends and tendencies referred to in the published studies related to “problem based learning” areas. In this research, Science Direct and Ulakbim were used as our main database resources. The sample of this study consists of 150 articles.

  13. Problem Solving Reasoning and Problem Based Instruction in Geometry Learning

    Science.gov (United States)

    Sulistyowati, F.; Budiyono, B.; Slamet, I.

    2017-09-01

    This research aims to analyze the comparison Problem Solving Reasoning (PSR) and Problem Based Instruction (PBI) on problem solving and mathematical communication abilities viewed from Self-Regulated Learning (SRL). Learning was given to grade 8th junior high school students. This research uses quasi experimental method, and then with descriptive analysis. Data were analyzed using two-ways multivariate analysis of variance (MANOVA) and one-way analysis of variance (ANOVA) with different cells. The result of data analysis were learning model gives different effect, level of SRL gives the same effect, and there is no interaction between the learning model with the SRL on the problem solving and mathematical communication abilities. The t-test statistic was used to find out more effective learning model. Based on the test, regardless of the level of SRL, PSR is more effective than PBI for problemsolving ability. The result of descriptive analysis was PSR had the advantage in creating learning that optimizing the ability of learners in reasoning to solve a mathematical problem. Consequently, the PSR is the right learning model to be applied in the classroom to improve problem solving ability of learners.

  14. Understanding hydraulic fracturing: a multi-scale problem

    Science.gov (United States)

    Hyman, J. D.; Jiménez-Martínez, J.; Viswanathan, H. S.; Carey, J. W.; Porter, M. L.; Rougier, E.; Karra, S.; Kang, Q.; Frash, L.; Chen, L.; Lei, Z.; O’Malley, D.; Makedonska, N.

    2016-01-01

    Despite the impact that hydraulic fracturing has had on the energy sector, the physical mechanisms that control its efficiency and environmental impacts remain poorly understood in part because the length scales involved range from nanometres to kilometres. We characterize flow and transport in shale formations across and between these scales using integrated computational, theoretical and experimental efforts/methods. At the field scale, we use discrete fracture network modelling to simulate production of a hydraulically fractured well from a fracture network that is based on the site characterization of a shale gas reservoir. At the core scale, we use triaxial fracture experiments and a finite-discrete element model to study dynamic fracture/crack propagation in low permeability shale. We use lattice Boltzmann pore-scale simulations and microfluidic experiments in both synthetic and shale rock micromodels to study pore-scale flow and transport phenomena, including multi-phase flow and fluids mixing. A mechanistic description and integration of these multiple scales is required for accurate predictions of production and the eventual optimization of hydrocarbon extraction from unconventional reservoirs. Finally, we discuss the potential of CO2 as an alternative working fluid, both in fracturing and re-stimulating activities, beyond its environmental advantages. This article is part of the themed issue ‘Energy and the subsurface’. PMID:27597789

  15. Problem-based learning and radiology

    International Nuclear Information System (INIS)

    Thurley, P.; Dennick, R.

    2008-01-01

    The Royal College of Radiologists recently published documents setting out guidelines to improve the teaching of radiology to medical students. These included recommendations that clinicians who teach radiology should be aware of newer educational techniques, such as problem-based learning, and should be involved in the development of curricula and assessment in medical schools. This review aims to introduce the educational theories behind problem-based learning and describe how a problem-based learning tutorial is run. The relevance of problem-based learning to radiology and the potential advantages and disadvantages are discussed

  16. Implementation of exterior complex scaling in B-splines to solve atomic and molecular collision problems

    International Nuclear Information System (INIS)

    McCurdy, C William; MartIn, Fernando

    2004-01-01

    B-spline methods are now well established as widely applicable tools for the evaluation of atomic and molecular continuum states. The mathematical technique of exterior complex scaling has been shown, in a variety of other implementations, to be a powerful method with which to solve atomic and molecular scattering problems, because it allows the correct imposition of continuum boundary conditions without their explicit analytic application. In this paper, an implementation of exterior complex scaling in B-splines is described that can bring the well-developed technology of B-splines to bear on new problems, including multiple ionization and breakup problems, in a straightforward way. The approach is demonstrated for examples involving the continuum motion of nuclei in diatomic molecules as well as electronic continua. For problems involving electrons, a method based on Poisson's equation is presented for computing two-electron integrals over B-splines under exterior complex scaling

  17. Leadership solves collective action problems in small-scale societies

    Science.gov (United States)

    Glowacki, Luke; von Rueden, Chris

    2015-01-01

    Observation of leadership in small-scale societies offers unique insights into the evolution of human collective action and the origins of sociopolitical complexity. Using behavioural data from the Tsimane forager-horticulturalists of Bolivia and Nyangatom nomadic pastoralists of Ethiopia, we evaluate the traits of leaders and the contexts in which leadership becomes more institutional. We find that leaders tend to have more capital, in the form of age-related knowledge, body size or social connections. These attributes can reduce the costs leaders incur and increase the efficacy of leadership. Leadership becomes more institutional in domains of collective action, such as resolution of intragroup conflict, where collective action failure threatens group integrity. Together these data support the hypothesis that leadership is an important means by which collective action problems are overcome in small-scale societies. PMID:26503683

  18. Leadership solves collective action problems in small-scale societies.

    Science.gov (United States)

    Glowacki, Luke; von Rueden, Chris

    2015-12-05

    Observation of leadership in small-scale societies offers unique insights into the evolution of human collective action and the origins of sociopolitical complexity. Using behavioural data from the Tsimane forager-horticulturalists of Bolivia and Nyangatom nomadic pastoralists of Ethiopia, we evaluate the traits of leaders and the contexts in which leadership becomes more institutional. We find that leaders tend to have more capital, in the form of age-related knowledge, body size or social connections. These attributes can reduce the costs leaders incur and increase the efficacy of leadership. Leadership becomes more institutional in domains of collective action, such as resolution of intragroup conflict, where collective action failure threatens group integrity. Together these data support the hypothesis that leadership is an important means by which collective action problems are overcome in small-scale societies. © 2015 The Author(s).

  19. Problem Based Learning - Linking Students and Industry

    DEFF Research Database (Denmark)

    Fink, Flemming K.

    2006-01-01

    WG2_G4 Problem based learning – linking students and industry: a case study from Aalborg, Denmark Flemming K. Flink ELITE Aalborg University In Aalborg University, Denmark, all study programmes are organised around inter-disciplinary project work in groups. Up to 50% of the study work is problem-...... is essentially problem solving. The presentation looks into on campus POPBL and the Facilitated Work Based Learning (FBL) for continuing education. It also presents case examples of POPBL work....

  20. Problem-Based Learning Approaches in Meteorology

    Science.gov (United States)

    Charlton-Perez, Andrew James

    2013-01-01

    Problem-Based Learning, despite recent controversies about its effectiveness, is used extensively as a teaching method throughout higher education. In meteorology, there has been little attempt to incorporate Problem-Based Learning techniques into the curriculum. Motivated by a desire to enhance the reflective engagement of students within a…

  1. Airfoil optimization for noise emission problem on small scale turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gocmen, Tuhfe; Ozerdem, Baris [Mechanical Engineering Department, Yzmir Institute of Technology (Turkey)

    2011-07-01

    Wind power is a preferred natural resource and has had benefits for the energy industry and for the environment all over the world. However, noise emission from wind turbines is becoming a major concern today. This study paid close attention to small scale wind turbines close to urban areas and proposes an optimum number of six airfoils to address noise emission concerns and performance criteria. The optimization process aimed to decrease the noise emission levels and enhance the aerodynamic performance of a small scale wind turbine. This study determined the sources and the operating conditions of broadband noise emissions. A new design is presented which enhances aerodynamic performance and at the same time reduces airfoil self noise. It used popular aerodynamic functions and codes based on aero-acoustic empirical models. Through numerical computations and analyses, it is possible to derive useful improvements that can be made to commercial airfoils for small scale wind turbines.

  2. Relaxing the weak scale: A new approach to the hierarchy problem

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Recently, a new mechanism to generate a naturally small electroweak scale has been proposed. This is based on the idea that a dynamical evolution during the early universe can drive the Higgs mass to a value much smaller than the UV cutoff of the SM. In this talk I will present this idea, its explicit realizations, potential problems, and experimental consequences.

  3. A note on solving large-scale zero-one programming problems

    NARCIS (Netherlands)

    Adema, Jos J.

    1988-01-01

    A heuristic for solving large-scale zero-one programming problems is provided. The heuristic is based on the modifications made by H. Crowder et al. (1983) to the standard branch-and-bound strategy. First, the initialization is modified. The modification is only useful if the objective function

  4. MEMECAHKAN MASALAH GEOGRAFI MELALUI PROBLEM BASED LEARNING

    Directory of Open Access Journals (Sweden)

    Sujiono Sujiono

    2018-01-01

    Full Text Available This study aims to determine the effect of Problem Based Learning model on geography problem-solving sklills. This research model is quasi experiment with non-equivalent control group design. The subjects of the study were the students of XI IPS SMA Negeri 1 Pulau Laut Timur, academic year 2016/2017. The assessment instrument is an essay test based on an indicator of problem solving skills, ie (1 identifying problems; (2 formulate the problem; (3 finding alternative solutions; (4 choose alternative solutions; and (5 make conclusions. Data analysis using independent sample t-test model with 5% significance level. The results showed that there is an influence of PBL model on geography problem-solving sklills. The geography problem-solving skills of experimental class with PBL model is higher than control class with conventional model. Suggestion given, that is to make a plan of learning well and doing learning PBL on outdoor study.   Keywords Problem Based Learning, problem-solving skills, geography   http://dx.doi.org/10.17977/um022v2i22017p072

  5. Base problems and territories giving concern

    International Nuclear Information System (INIS)

    2005-01-01

    This article presents three base groups of problems in the area of environment and security: access to natural resources and their quality (water and soil and also forests and biodiversity); existent or potential pollution, cause of which can be industry, regions of burial places of dangerous or radioactive wastes; general problems, as natural disasters, climate changes, ecology policy

  6. Problem-Based Composition: The Practical Side

    Science.gov (United States)

    Beckelhimer, Lisa; Hundemer, Ronald; Sharp, Judith; Zipfel, William

    2007-01-01

    For several years a number of instructors at the University of Cincinnati have experimented with the concept of problem-based learning (PBL) in their composition courses. The concept, rooted as it is in Socratic method and the hands-on problem-solving advocated by John Dewey, is not new, and though some of its applications may call for adjustments…

  7. Scaling the robustness of the solutions for quantum controllable problems

    International Nuclear Information System (INIS)

    Kallush, S.; Kosloff, R.

    2011-01-01

    The major task in quantum control theory is to find an external field that transforms the system from one state to another or executes a predetermined unitary transformation. We investigate the difficulty of computing the control field as the size of the Hilbert space is increased. In the models studied the controls form a small closed subalgebra of operators. Complete controllability is obtained by the commutators of the controls with the stationary Hamiltonian. We investigate the scaling of the computation effort required to converge a solution for the quantum control task with respect to the size of the Hilbert space. The models studied include the double-well Bose Hubbard model with the SU(2) control subalgebra and the Morse oscillator with the Heisenberg-Weil algebra. We find that for initial and target states that are classified as generalized coherent states (GCSs) of the control subalgebra the control field is easily found independent of the size of the Hilbert space. For such problems, a control field generated for a small system can serve as a pilot for finding the field for larger systems. Attempting to employ pilot fields that generate superpositions of GCSs or cat states failed. No relation was found between control solutions of different Hilbert space sizes. In addition the task of finding such a field scales unfavorably with Hilbert space sizes. We demonstrate the use of symmetry to obtain quantum transitions between states without phase information. Implications to quantum computing are discussed.

  8. Minimization of Linear Functionals Defined on| Solutions of Large-Scale Discrete Ill-Posed Problems

    DEFF Research Database (Denmark)

    Elden, Lars; Hansen, Per Christian; Rojas, Marielba

    2003-01-01

    The minimization of linear functionals de ned on the solutions of discrete ill-posed problems arises, e.g., in the computation of con dence intervals for these solutions. In 1990, Elden proposed an algorithm for this minimization problem based on a parametric-programming reformulation involving...... the solution of a sequence of trust-region problems, and using matrix factorizations. In this paper, we describe MLFIP, a large-scale version of this algorithm where a limited-memory trust-region solver is used on the subproblems. We illustrate the use of our algorithm in connection with an inverse heat...

  9. Time scales and the problem of radioactive waste

    International Nuclear Information System (INIS)

    Goble, R.L.

    1984-01-01

    The author argues that decisions about future nuclear development can be made essentially independent of waste management considerations for the next 20 years. His arguments are based on five propositions: 1 Risks and costs of storing spent fuel or high-level waste and transuranics are lower than other directly comparable risks and costs of operating a reactor. 2 Storage of mill tailings is the most serious long-term waste problem; it is not serious enough to rule out the use of nuclear power. 3 There are compelling reasons for beginning to implement a waste management program now. 4 It is important to separate the problem of providing temporary storage from that of finding permanent repositories. 5 A prudent waste management strategy, by 2000, will have identified and evaluated more than enough repository space for the waste generated by that time, independent of the decision made about nuclear futures. 13 references, 4 figures, 4 tables

  10. Problem Based Learning, curriculum development and change ...

    African Journals Online (AJOL)

    Problem Based Learning, curriculum development and change process at ... was started in 1924 and has been running a traditional curriculum for 79 years. ... Methods: The stages taken during the process were described and analysed.

  11. Learning from the problems of problem-based learning

    Directory of Open Access Journals (Sweden)

    Epstein Richard

    2004-01-01

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

  12. Developing Mathematics Problems Based on Pisa Level

    Directory of Open Access Journals (Sweden)

    Shahibul Ahyan

    2014-01-01

    Full Text Available This research aims to produce mathematics problems based on PISA level with valid and practical content of change and relationships and has potential effect for Junior High School students. A development research method developed by Akker, Gravemeijer, McKenney and Nieveen is used this research. In the first stage, the researcher analyzed students, algebra material in school-based curricula (KTSP and mathematics problems of PISA 2003 of change and relationships content. The second stage, the researcher designed 13 problems with content of change and relationships. The last, the researcher used formative evaluation design developed by Tessmer which includes self evaluation, one-to-one, expert review, small group, and field test. The data collect by walk through, interview, and questionnaire. The result of this research indicated that 12 mathematical problems based on PISA level of change and relationships content that developed have validity, practically, and potential effects for Junior High School students.

  13. Side effects of problem-solving strategies in large-scale nutrition science: towards a diversification of health.

    Science.gov (United States)

    Penders, Bart; Vos, Rein; Horstman, Klasien

    2009-11-01

    Solving complex problems in large-scale research programmes requires cooperation and division of labour. Simultaneously, large-scale problem solving also gives rise to unintended side effects. Based upon 5 years of researching two large-scale nutrigenomic research programmes, we argue that problems are fragmented in order to be solved. These sub-problems are given priority for practical reasons and in the process of solving them, various changes are introduced in each sub-problem. Combined with additional diversity as a result of interdisciplinarity, this makes reassembling the original and overall goal of the research programme less likely. In the case of nutrigenomics and health, this produces a diversification of health. As a result, the public health goal of contemporary nutrition science is not reached in the large-scale research programmes we studied. Large-scale research programmes are very successful in producing scientific publications and new knowledge; however, in reaching their political goals they often are less successful.

  14. Bridging disciplines through problem based learning

    DEFF Research Database (Denmark)

    Stentoft, Diana

    2011-01-01

    This paper examines whether a problem based approach to students’ learning may support interdisciplinary education at university level, where students are required to engage with the complexities inherent in constructing knowledge across disciplinary boundaries. These complexities include students...... engaging with multiple and conflicting epistemologies, identification and contextualisation of problems involving several disciplines in their solution etc. A practical example found in the case of newly developed BSc and MSc programs in Techno-Anthropology is provided.The paper includes some examples...

  15. Development of a nursing care problems coping scale for male caregivers for people with dementia living at home.

    Science.gov (United States)

    Nishio, Midori; Ono, Mitsu

    2015-01-01

    The number of male caregivers has increased, but male caregivers face several problems that reduce their quality of life and psychological condition. This study focused on the coping problems of men who care for people with dementia at home. It aimed to develop a coping scale for male caregivers so that they can continue caring for people with dementia at home and improve their own quality of life. The study also aimed to verify the reliability and validity of the scale. The subjects were 759 men who care for people with dementia at home. The Care Problems Coping Scale consists of 21 questions based on elements of questions extracted from a pilot study. Additionally, subjects completed three self-administered questionnaires: the Japanese version of the Zarit Caregiver Burden Scale, the Depressive Symptoms and the Self-esteem Emotional Scale, and Rosenberg Self-Esteem Scale. There were 274 valid responses (36.1% response rate). Regarding the answer distribution, each average value of the 21 items ranged from 1.56 to 2.68. The median answer distribution of the 21 items was 39 (SD = 6.6). Five items had a ceiling effect, and two items had a floor effect. The scale stability was about 50%, and Cronbach's α was 0.49. There were significant correlations between the Care Problems Coping Scale and total scores of the Japanese version of the Zarit Caregiver Burden Scale, the Depressive Symptoms and Self-esteem Emotional Scale, and the Rosenberg Self-Esteem Scale. The answers provided on the Care Problems Coping Scale questionnaire indicated that male caregivers experience care problems. In terms of validity, there were significant correlations between the external questionnaires and 19 of the 21 items in this scale. This scale can therefore be used to measure problems with coping for male caregivers who care for people with dementia at home.

  16. Absolute mass scale calibration in the inverse problem of the physical theory of fireballs.

    Science.gov (United States)

    Kalenichenko, V. V.

    A method of the absolute mass scale calibration is suggested for solving the inverse problem of the physical theory of fireballs. The method is based on the data on the masses of the fallen meteorites whose fireballs have been photographed in their flight. The method may be applied to those fireballs whose bodies have not experienced considerable fragmentation during their destruction in the atmosphere and have kept their form well enough. Statistical analysis of the inverse problem solution for a sufficiently representative sample makes it possible to separate a subsample of such fireballs. The data on the Lost City and Innisfree meteorites are used to obtain calibration coefficients.

  17. Teaching Gases through Problem-Based Learning

    Science.gov (United States)

    Baran, Mukadder

    2016-01-01

    The purpose of this study was to investigate not only the applicability of the method of Problem-Based Learning (PBL) to the lesson subject of "Gasses" within the scope of the 9th grade course of Chemistry in Hakkari Gazi High School but also the influence of this method on the students' achievement levels in chemistry and on their…

  18. Using Scaffolds in Problem-Based Hypermedia

    Science.gov (United States)

    Su, Yuyan; Klein, James D.

    2010-01-01

    This study investigated the use of scaffolds in problem-based hypermedia. Three hundred and twelve undergraduate students enrolled in a computer literacy course worked in project teams to use a hypermedia PBL program focused on designing a personal computer. The PBL program included content scaffolds, metacognitive scaffolds, or no scaffolds.…

  19. Producing and Scrounging during Problem Based Learning

    Science.gov (United States)

    Vickery, William L.

    2013-01-01

    When problem based learning occurs in a social context it is open to a common social behaviour, scrounging. In the animal behaviour literature, scroungers do not attempt to find resources themselves but rather exploit resources found by other group members (referred to as producers). We know from studies of animal behaviour (including humans) that…

  20. Problem Based Learning in Engineering Education

    DEFF Research Database (Denmark)

    Dahms, Mona-Lisa; Sauerbier, Gabriele; Stubbe, Korinna

    2006-01-01

    This paper describes a recent EU-project from five European Institutions. The aim was the development and implementation of a new international Master’s programme for staff development, directed towards the introduction of Problem Based Learning methods in the field of engineering education...

  1. A comparison of problem-based and traditional education on nursing students' locus of control and problem-solving skills.

    Science.gov (United States)

    Günüşen, Neslihan Partlak; Serçekuş, Pınar; Edeer, Aylin Durmaz

    2014-06-01

    The purpose of this study is to compare the locus of control and problem-solving skills of nursing students studying with the problem-based learning method with those of nursing students studying with the traditional method. This is a descriptive and comparative study. For data collection, the Problem-Solving Skills Inventory and the Locus of Control Scale were used. The study sample included 680 nursing students. It was determined that the problem-based learning method was more effective in the development of problem-solving skills and internal locus of control than was the traditional method. © 2014 NANDA International.

  2. Dysfunctional problem-based learning curricula: resolving the problem

    Directory of Open Access Journals (Sweden)

    Lim William K

    2012-09-01

    Full Text Available Abstract Background Problem-based learning (PBL has become the most significant innovation in medical education of the past 40 years. In contrast to exam-centered, lecture-based conventional curricula, PBL is a comprehensive curricular strategy that fosters student-centred learning and the skills desired in physicians. The rapid spread of PBL has produced many variants. One of the most common is 'hybrid PBL' where conventional teaching methods are implemented alongside PBL. This paper contends that the mixing of these two opposing educational philosophies can undermine PBL and nullify its positive benefits. Schools using hybrid PBL and lacking medical education expertise may end up with a dysfunctional curriculum worse off than the traditional approach. Discussion For hybrid PBL schools with a dysfunctional curriculum, standard PBL is a cost-feasible option that confers the benefits of the PBL approach. This paper describes the signs of a dysfunctional PBL curriculum to aid hybrid PBL schools in recognising curricular breakdown. Next it discusses alternative curricular strategies and costs associated with PBL. It then details the four critical factors for successful conversion to standard PBL: dealing with staff resistance, understanding the role of lectures, adequate time for preparation and support from the administrative leadership. Summary Hybrid PBL curricula without oversight by staff with medical education expertise can degenerate into dysfunctional curricula inferior even to the traditional approach from which PBL emerged. Such schools should inspect their curriculum periodically for signs of dysfunction to enable timely corrective action. A decision to convert fully to standard PBL is cost feasible but will require time, expertise and commitment which is only sustainable with supportive leadership.

  3. Using standardized patients versus video cases for representing clinical problems in problem-based learning.

    Science.gov (United States)

    Yoon, Bo Young; Choi, Ikseon; Choi, Seokjin; Kim, Tae-Hee; Roh, Hyerin; Rhee, Byoung Doo; Lee, Jong-Tae

    2016-06-01

    The quality of problem representation is critical for developing students' problem-solving abilities in problem-based learning (PBL). This study investigates preclinical students' experience with standardized patients (SPs) as a problem representation method compared to using video cases in PBL. A cohort of 99 second-year preclinical students from Inje University College of Medicine (IUCM) responded to a Likert scale questionnaire on their learning experiences after they had experienced both video cases and SPs in PBL. The questionnaire consisted of 14 items with eight subcategories: problem identification, hypothesis generation, motivation, collaborative learning, reflective thinking, authenticity, patient-doctor communication, and attitude toward patients. The results reveal that using SPs led to the preclinical students having significantly positive experiences in boosting patient-doctor communication skills; the perceived authenticity of their clinical situations; development of proper attitudes toward patients; and motivation, reflective thinking, and collaborative learning when compared to using video cases. The SPs also provided more challenges than the video cases during problem identification and hypotheses generation. SPs are more effective than video cases in delivering higher levels of authenticity in clinical problems for PBL. The interaction with SPs engages preclinical students in deeper thinking and discussion; growth of communication skills; development of proper attitudes toward patients; and motivation. Considering the higher cost of SPs compared with video cases, SPs could be used most advantageously during the preclinical period in the IUCM curriculum.

  4. An inverse problem strategy based on forward model evaluations: Gradient-based optimization without adjoint solves

    Energy Technology Data Exchange (ETDEWEB)

    Aguilo Valentin, Miguel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-07-01

    This study presents a new nonlinear programming formulation for the solution of inverse problems. First, a general inverse problem formulation based on the compliance error functional is presented. The proposed error functional enables the computation of the Lagrange multipliers, and thus the first order derivative information, at the expense of just one model evaluation. Therefore, the calculation of the Lagrange multipliers does not require the solution of the computationally intensive adjoint problem. This leads to significant speedups for large-scale, gradient-based inverse problems.

  5. Effective field theory analysis on μ problem in low-scale gauge mediation

    International Nuclear Information System (INIS)

    Zheng Sibo

    2012-01-01

    Supersymmetric models based on the scenario of gauge mediation often suffer from the well-known μ problem. In this paper, we reconsider this problem in low-scale gauge mediation in terms of effective field theory analysis. In this paradigm, all high energy input soft mass can be expressed via loop expansions. If the corrections coming from messenger thresholds are small, as we assume in this letter, then all RG evaluations can be taken as linearly approximation for low-scale supersymmetric breaking. Due to these observations, the parameter space can be systematically classified and studied after constraints coming from electro-weak symmetry breaking are imposed. We find that some old proposals in the literature are reproduced, and two new classes are uncovered. We refer to a microscopic model, where the specific relations among coefficients in one of the new classes are well motivated. Also, we discuss some primary phenomenologies.

  6. Sparse deconvolution for the large-scale ill-posed inverse problem of impact force reconstruction

    Science.gov (United States)

    Qiao, Baijie; Zhang, Xingwu; Gao, Jiawei; Liu, Ruonan; Chen, Xuefeng

    2017-01-01

    Most previous regularization methods for solving the inverse problem of force reconstruction are to minimize the l2-norm of the desired force. However, these traditional regularization methods such as Tikhonov regularization and truncated singular value decomposition, commonly fail to solve the large-scale ill-posed inverse problem in moderate computational cost. In this paper, taking into account the sparse characteristic of impact force, the idea of sparse deconvolution is first introduced to the field of impact force reconstruction and a general sparse deconvolution model of impact force is constructed. Second, a novel impact force reconstruction method based on the primal-dual interior point method (PDIPM) is proposed to solve such a large-scale sparse deconvolution model, where minimizing the l2-norm is replaced by minimizing the l1-norm. Meanwhile, the preconditioned conjugate gradient algorithm is used to compute the search direction of PDIPM with high computational efficiency. Finally, two experiments including the small-scale or medium-scale single impact force reconstruction and the relatively large-scale consecutive impact force reconstruction are conducted on a composite wind turbine blade and a shell structure to illustrate the advantage of PDIPM. Compared with Tikhonov regularization, PDIPM is more efficient, accurate and robust whether in the single impact force reconstruction or in the consecutive impact force reconstruction.

  7. Mathematical programming methods for large-scale topology optimization problems

    DEFF Research Database (Denmark)

    Rojas Labanda, Susana

    for mechanical problems, but has rapidly extended to many other disciplines, such as fluid dynamics and biomechanical problems. However, the novelty and improvements of optimization methods has been very limited. It is, indeed, necessary to develop of new optimization methods to improve the final designs......, and at the same time, reduce the number of function evaluations. Nonlinear optimization methods, such as sequential quadratic programming and interior point solvers, have almost not been embraced by the topology optimization community. Thus, this work is focused on the introduction of this kind of second...... for the classical minimum compliance problem. Two of the state-of-the-art optimization algorithms are investigated and implemented for this structural topology optimization problem. A Sequential Quadratic Programming (TopSQP) and an interior point method (TopIP) are developed exploiting the specific mathematical...

  8. Problem based Learning in surveying Education

    DEFF Research Database (Denmark)

    Enemark, Stig

    The challenge of the future will be that the only constant is change. Therefore, the educational base must be flexible. The graduates must possess skills to adapt to a rapidly changing labour market and they must possess skills to deal with even the unknown problems of the future. The point is...... that opportunity. The basis principles of this educational model are presented using the surveying programme at Aalborg University as an example....

  9. FEM × DEM: a new efficient multi-scale approach for geotechnical problems with strain localization

    Directory of Open Access Journals (Sweden)

    Nguyen Trung Kien

    2017-01-01

    Full Text Available The paper presents a multi-scale modeling of Boundary Value Problem (BVP approach involving cohesive-frictional granular materials in the FEM × DEM multi-scale framework. On the DEM side, a 3D model is defined based on the interactions of spherical particles. This DEM model is built through a numerical homogenization process applied to a Volume Element (VE. It is then paired with a Finite Element code. Using this numerical tool that combines two scales within the same framework, we conducted simulations of biaxial and pressuremeter tests on a cohesive-frictional granular medium. In these cases, it is known that strain localization does occur at the macroscopic level, but since FEMs suffer from severe mesh dependency as soon as shear band starts to develop, the second gradient regularization technique has been used. As a consequence, the objectivity of the computation with respect to mesh dependency is restored.

  10. Controlling Barium Sulphate Scale Deposition Problems in an unbleached Kraft Paper Mill

    CSIR Research Space (South Africa)

    Sithole, Bruce

    2015-06-01

    Full Text Available Troubleshooting of scale deposits and defects in paper samples showed that the problem was caused by barium sulphate and calcium sulphate scales. However, it was ascertained that barium sulphate was more of a concern than calcium sulphate...

  11. Some problems of NPP construction base improvement

    International Nuclear Information System (INIS)

    Movchan, S.V.

    1984-01-01

    NPP construction bases are characterized by high cost of construction and large area. Duration of base construction makes up 3-4 years, labour contents for their erection constitute 600-900 thousand man-days. Delays in organizing functional base services essentially decelerate construction rates of the main NPP buildings. Maximum joining of separate buildings by their functional assignment and structural peculiarities, wide application of container buildings, partial utilization of permanent buildings of production centre for construction needs; transition to new organizational form of construction based on industrial production of buildings; production of volumetric structural-technological cells with mounted equipment manufactured at specialized plants, mounting NPP components with stock produced cells, consideration of the problem of large power centre creation are necessary for reduction of construction centres, area reduction of cost and duration of their construction

  12. Managing the Gap between Curriculum Based and Problem Based Learning

    DEFF Research Database (Denmark)

    Bygholm, Ann; Buus, Lillian

    2009-01-01

    /or but rather both/and. In this paper we describe an approach to design and delivery of online courses in computer science which on the one hand is based on a specified curriculum and on the other hand gives room for different learning strategies, problem based learning being one of them. We discuss......Traditionally there has been a clear distinction between curriculum based and problem based approaches to accomplish learning. Preferred approaches depend of course on conviction, culture, traditions and also on the specific learning situation. We will argue that it is not a question of either...

  13. [Modeling continuous scaling of NDVI based on fractal theory].

    Science.gov (United States)

    Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng

    2013-07-01

    Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing.

  14. Newton Methods for Large Scale Problems in Machine Learning

    Science.gov (United States)

    Hansen, Samantha Leigh

    2014-01-01

    The focus of this thesis is on practical ways of designing optimization algorithms for minimizing large-scale nonlinear functions with applications in machine learning. Chapter 1 introduces the overarching ideas in the thesis. Chapters 2 and 3 are geared towards supervised machine learning applications that involve minimizing a sum of loss…

  15. Teaching Problem Based Learning as Blended Learning

    DEFF Research Database (Denmark)

    Kolbæk, Ditte; Nortvig, Anne-Mette

    2018-01-01

    Problem-based and project organized learning (PBL) was originally developed for collaboration between physically present students, but political decisions at many universities require that collaboration, dialogues, and other PBL activities take place online as well. With a theoretical point...... of departure in Dewey and a methodological point of departure in netnography, this study focuses on an online module at Aalborg University where teaching is based on PBL. With the research question ‘How can teachers design for PBL online,’ this study explores the teacher’s role in a six weeks’ blended learning...... program, and we present suggestions for designs for blended learning PBL based on case studies from two PBL courses...

  16. Educational Change towards Problem Based Learning

    DEFF Research Database (Denmark)

    Li, Huichun

    As a promising educational approach, PBL (Problem Based Learning) has been adopted by an increasing number of higher education institutions worldwide to replace the traditional lectured based educational approach. However, the organizational change towards PBL is not easy for higher education...... universities which are transforming their traditional educational approaches to PBL. Specifically, this book is concerned with how managers, staff members, and students interpret PBL and its implementation. It reveals that the challenges for implementing PBL are closely linked to organizational members...... institutions, especially for those with a long history of Lecture Based Learning. Therefore, it is necessary to investigate the challenges and obstacles for higher education institutions which are implementing PBL. In order to address the research concern, this book involves in an intensive exploration of two...

  17. Multiple Scale Reaction-Diffusion-Advection Problems with Moving Fronts

    Science.gov (United States)

    Nefedov, Nikolay

    2016-06-01

    In this work we discuss the further development of the general scheme of the asymptotic method of differential inequalities to investigate stability and motion of sharp internal layers (fronts) for nonlinear singularly perturbed parabolic equations, which are called in applications reaction-diffusion-advection equations. Our approach is illustrated for some new important cases of initial boundary value problems. We present results on stability and on the motion of the fronts.

  18. Problems in event based engine control

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Jensen, Michael; Chevalier, Alain Marie Roger

    1994-01-01

    Physically a four cycle spark ignition engine operates on the basis of four engine processes or events: intake, compression, ignition (or expansion) and exhaust. These events each occupy approximately 180° of crank angle. In conventional engine controllers, it is an accepted practice to sample...... the engine variables synchronously with these events (or submultiples of them). Such engine controllers are often called event-based systems. Unfortunately the main system noise (or disturbance) is also synchronous with the engine events: the engine pumping fluctuations. Since many electronic engine...... problems on accurate air/fuel ratio control of a spark ignition (SI) engine....

  19. Problem based learning - A brief review

    Science.gov (United States)

    Nunes, Sandra; Oliveira, Teresa A.; Oliveira, Amílcar

    2017-07-01

    Teaching is a complex mission that requires not only the theoretical knowledge transmission, but furthermore requires to provide the students the necessary skills for solving real problems in their respective professional activities where complex issues and problems must be frequently faced. Over more than twenty years we have been experiencing an increase in scholar failure in the scientific area of mathematics, which means that Teaching Mathematics and related areas can be even a more complex and hard task. Scholar failure is a complex phenomenon that depends on various factors as social factors, scholar factors or biophysical factors. After numerous attempts made in order to reduce scholar failure our goal in this paper is to understand the role of "Problem Based Learning" and how this methodology can contribute to the solution of both: increasing mathematical courses success and increasing skills in the near future professionals in Portugal. Before designing a proposal for applying this technique in our institutions, we decided to conduct a survey to provide us with the necessary information about and the respective advantages and disadvantages of this methodology, so this is the brief review aim.

  20. Absolute calibration of the mass scale in the inverse problem of the physical theory of fireballs

    Science.gov (United States)

    Kalenichenko, V. V.

    1992-08-01

    A method of the absolute calibration of the mass scale is proposed for solving the inverse problem of the physical theory of fireballs. The method is based on data on the masses of fallen meteorites whose fireballs have been photographed in flight. The method can be applied to fireballs whose bodies have not experienced significant fragmentation during their flight in the atmosphere and have kept their shape relatively well. Data on the Lost City and Innisfree meteorites are used to calculate the calibration coefficients.

  1. Optimal Experimental Design for Large-Scale Bayesian Inverse Problems

    KAUST Repository

    Ghattas, Omar

    2014-01-06

    We develop a Bayesian framework for the optimal experimental design of the shock tube experiments which are being carried out at the KAUST Clean Combustion Research Center. The unknown parameters are the pre-exponential parameters and the activation energies in the reaction rate expressions. The control parameters are the initial mixture composition and the temperature. The approach is based on first building a polynomial based surrogate model for the observables relevant to the shock tube experiments. Based on these surrogates, a novel MAP based approach is used to estimate the expected information gain in the proposed experiments, and to select the best experimental set-ups yielding the optimal expected information gains. The validity of the approach is tested using synthetic data generated by sampling the PC surrogate. We finally outline a methodology for validation using actual laboratory experiments, and extending experimental design methodology to the cases where the control parameters are noisy.

  2. Short scales to assess cannabis-related problems: a review of psychometric properties

    Directory of Open Access Journals (Sweden)

    Klempova Danica

    2008-12-01

    Full Text Available Abstract Aims The purpose of this paper is to summarize the psychometric properties of four short screening scales to assess problematic forms of cannabis use: Severity of Dependence Scale (SDS, Cannabis Use Disorders Identification Test (CUDIT, Cannabis Abuse Screening Test (CAST and Problematic Use of Marijuana (PUM. Methods A systematic computer-based literature search was conducted within the databases of PubMed, PsychINFO and Addiction Abstracts. A total of 12 publications reporting measures of reliability or validity were identified: 8 concerning SDS, 2 concerning CUDIT and one concerning CAST and PUM. Studies spanned adult and adolescent samples from general and specific user populations in a number of countries worldwide. Results All screening scales tended to have moderate to high internal consistency (Cronbach's α ranging from .72 to .92. Test-retest reliability and item total correlation have been reported for SDS with acceptable results. Results of validation studies varied depending on study population and standards used for validity assessment, but generally sensitivity, specificity and predictive power are satisfactory. Standard diagnostic cut-off points that can be generalized to different populations do not exist for any scale. Conclusion Short screening scales to assess dependence and other problems related to the use of cannabis seem to be a time and cost saving opportunity to estimate overall prevalences of cannabis-related negative consequences and to identify at-risk persons prior to using more extensive diagnostic instruments. Nevertheless, further research is needed to assess the performance of the tests in different populations and in comparison to broader criteria of cannabis-related problems other than dependence.

  3. Problem-based learning for technical students on the base TRIZ (theory of inventive problem solving

    Directory of Open Access Journals (Sweden)

    Babenko Oksana

    2016-01-01

    Full Text Available The basis of modern educational technology in teaching is problem-based learning through the use of educational technologies Powerful Thinking - Theory of Inventive Problem Solving (TRIZ, including a systematic approach to the complex organization of independent work of search and research character. Developed by systemic administration of the physical features workshops on the basis TRIZ in the cycle of the natural sciences with the implementation of all aspects of the educational activities - substantive, procedural and motivational. A new model of the physical design of the workshop and its form of organization, which is based on problem-based learning with the use of TRIZ Interactive form of organization of the workshop allows you to get high-quality substantive and personality of the students who have a significant role in the formation of professional competencies and affect the quality of produce practice-oriented specialists.

  4. Beyond Problem-Based Learning: Using Dynamic PBL in Chemistry

    Science.gov (United States)

    Overton, Tina L.; Randles, Christopher A.

    2015-01-01

    This paper describes the development and implementation of a novel pedagogy, dynamic problem-based learning. The pedagogy utilises real-world problems that evolve throughout the problem-based learning activity and provide students with choice and different data sets. This new dynamic problem-based learning approach was utilised to teach…

  5. Enabling High Performance Large Scale Dense Problems through KBLAS

    KAUST Repository

    Abdelfattah, Ahmad

    2014-05-04

    KBLAS (KAUST BLAS) is a small library that provides highly optimized BLAS routines on systems accelerated with GPUs. KBLAS is entirely written in CUDA C, and targets NVIDIA GPUs with compute capability 2.0 (Fermi) or higher. The current focus is on level-2 BLAS routines, namely the general matrix vector multiplication (GEMV) kernel, and the symmetric/hermitian matrix vector multiplication (SYMV/HEMV) kernel. KBLAS provides these two kernels in all four precisions (s, d, c, and z), with support to multi-GPU systems. Through advanced optimization techniques that target latency hiding and pushing memory bandwidth to the limit, KBLAS outperforms state-of-the-art kernels by 20-90% improvement. Competitors include CUBLAS-5.5, MAGMABLAS-1.4.0, and CULAR17. The SYMV/HEMV kernel from KBLAS has been adopted by NVIDIA, and should appear in CUBLAS-6.0. KBLAS has been used in large scale simulations of multi-object adaptive optics.

  6. Power, Democracy and Problem-Based Learning

    DEFF Research Database (Denmark)

    Du, Xiangyun; Stentoft, Diana; Dahms, Mona-Lisa

    2007-01-01

      Problem Based Learning (PBL) as an educational approach has been increasingly applied in educational settings around the world. Given that PBL - as well as any other educational approach - is rooted in a given cultural context and thus carries the ‘fingerprint' of the specific context......, an interesting question is: To which extent is PBL a universally applicable approach to teaching and learning, i.e. an approach which can be implemented successfully to all times and in all societies, independent of differences in social, cultural, political and economic contexts? With this question...... participants are teachers involved in technical education, who have an interest in initiating changes towards PBL in their institutions and/or in their educational practices. The participants are located in various parts of the world and thus bring diverse experiences to the course and the MPBL programme...

  7. Solution accelerators for large scale 3D electromagnetic inverse problems

    International Nuclear Information System (INIS)

    Newman, Gregory A.; Boggs, Paul T.

    2004-01-01

    We provide a framework for preconditioning nonlinear 3D electromagnetic inverse scattering problems using nonlinear conjugate gradient (NLCG) and limited memory (LM) quasi-Newton methods. Key to our approach is the use of an approximate adjoint method that allows for an economical approximation of the Hessian that is updated at each inversion iteration. Using this approximate Hessian as a preconditoner, we show that the preconditioned NLCG iteration converges significantly faster than the non-preconditioned iteration, as well as converging to a data misfit level below that observed for the non-preconditioned method. Similar conclusions are also observed for the LM iteration; preconditioned with the approximate Hessian, the LM iteration converges faster than the non-preconditioned version. At this time, however, we see little difference between the convergence performance of the preconditioned LM scheme and the preconditioned NLCG scheme. A possible reason for this outcome is the behavior of the line search within the LM iteration. It was anticipated that, near convergence, a step size of one would be approached, but what was observed, instead, were step lengths that were nowhere near one. We provide some insights into the reasons for this behavior and suggest further research that may improve the performance of the LM methods

  8. Problems of coal-based power generation

    International Nuclear Information System (INIS)

    Noskievic, P.

    1996-01-01

    Current problems of and future trends in coal-based power generation are discussed. The present situation is as follows: coal, oil and gas contribute to world fossil fuel resources 75%, 14%, and 11%, respectively, and if the current trend will continue, will be depleted in 240, 50, and 60 years, respectively; the maximum resource estimates (including resources that have not yet been discovered) are 50% higher for oil and 100% higher for gas, for coal such estimates have not been made. While the world prices of coal are expected to remain virtually constant, the prices of gas will probably increase to be twice as high in 2010. Thus, the role of coal may be higher in the next century than it is now, provided that due attention is paid to improving the efficiency of coal-fired power plants and reducing their adverse environmental effects. A comparison of economic data for coal-fired and gas-fired power plants is as follows: Investment cost (USD/kW): 1400, 800; fixed running cost (USD/kW.y): 33.67, 9.0; variable running cost (USD/kWh): 0.30, 0.15; power use (kJ/kWh): 10.29, 7.91; annual availability (%): 70, 50; fuel price (USD/GJ): 1.00, 4.30; power price (USD/kWh): 4.28, 5.52. The investment cost for coal-fired plants covers new construction including flue gas purification. The integrated gasification combined cycle (IGCC) seems to be the future of coal-based power generation. The future problems to be addressed include ways to reduce air pollution, improving the efficiency of the gas-steam cycle, and improving the combustion process particularly with a view to reducing substantially its environmental impact. (P.A.). 4 figs., 4 tabs., 9 refs

  9. Producing and scrounging during Problem Based Learning

    Directory of Open Access Journals (Sweden)

    William L. Vickery

    2013-08-01

    Full Text Available When problem based learning occurs in a social context it is open to a common social behaviour, scrounging. In the animal behaviour literature, scroungers do not attempt to find resources themselves but rather exploit resources found by other group members (referred to as producers. We know from studies of animal behaviour (including humans that scrounging can be expected whenever animals exploit resources in groups. We also know that scrounging can have deleterious effects on the group. We can expect scrounging to occur during social learning because the exchange of information (which I will consider here as a resource is essential to social learning. This exchange can be seen as each individual scrounging from the other members of the group whenever the individual learns from the work of others. However, there is a danger if some individuals learn mostly through their own efforts while others indulge in “social loafing” relying heavily on colleagues to provide knowledge. Here I propose that game theory models developed to analyse feeding in animal societies may also apply to social learning. We know from studies of birds feeding in groups that scrounging behaviour depends on the extent to which resources can be shared. Further, when scrounging is prevalent groups tend to obtain fewer resources. By contrast, in social learning we attempt to facilitate sharing of knowledge. We thus encourage scrounging and run the risk of reducing learning within study groups. Here I analyse the role of scrounging in problem based learning. I argue that scrounging is inherent and necessary to any social learning process. However, it can have perverse effects if the acquisition of facts rather than understanding comes to dominate learning objectives. Further, disparities among individuals within a group can lead certain individuals to specialise in scrounging thus undermining the functioning of the group. I suggest that motivation, problem structure

  10. Biopolitics problems of large-scale hydraulic engineering construction

    International Nuclear Information System (INIS)

    Romanenko, V.D.

    1997-01-01

    The XX century which will enter in a history as a century of large-scale hydraulic engineering constructions come to the finish. Only on the European continent 517 large reservoirs (more than 1000 million km 3 of water were detained, had been constructed for a period from 1901 till 1985. In the Danube basin a plenty for reservoirs of power stations, navigations, navigating sluices and other hydraulic engineering structures are constructed. Among them more than 40 especially large objects are located along the main bed of the river. A number of hydro-complexes such as Dnieper-Danube and Gabcikovo, Danube-Oder-Labe (project), Danube-Tissa, Danube-Adriatic Sea (project), Danube-Aegean Sea, Danube-Black Sea ones, are entered into operation or are in a stage of designing. Hydraulic engineering construction was especially heavily conducted in Ukraine. On its territory some large reservoirs on Dnieper and Yuzhny Bug were constructed, which have heavily changed the hydrological regime of the rivers. Summarised the results of river systems regulating in Ukraine one can be noted that more than 27 thousand ponds (3 km 3 per year), 1098 reservoirs of total volume 55 km 3 , 11 large channels of total length more than 2000 km and with productivity of 1000 m 2 /s have been created in Ukraine. Hydraulic engineering construction played an important role in development of the industry and agriculture, water-supply of the cities and settlements, in environmental effects, and maintenance of safe navigation in Danube, Dnieper and other rivers. In next part of the paper, the environmental changes after construction of the Karakum Channel on the Aral Sea in the Middle Asia are discussed

  11. Improvement of Monte Carlo code A3MCNP for large-scale shielding problems

    International Nuclear Information System (INIS)

    Miyake, Y.; Ohmura, M.; Hasegawa, T.; Ueki, K.; Sato, O.; Haghighat, A.; Sjoden, G.E.

    2004-01-01

    A 3 MCNP (Automatic Adjoint Accelerated MCNP) is a revised version of the MCNP Monte Carlo code, that automatically prepares variance reduction parameters for the CADIS (Consistent Adjoint Driven Importance Sampling) methodology. Using a deterministic 'importance' (or adjoint) function, CADIS performs source and transport biasing within the weight-window technique. The current version of A 3 MCNP uses the 3-D Sn transport TORT code to determine a 3-D importance function distribution. Based on simulation of several real-life problems, it is demonstrated that A 3 MCNP provides precise calculation results with a remarkably short computation time by using the proper and objective variance reduction parameters. However, since the first version of A 3 MCNP provided only a point source configuration option for large-scale shielding problems, such as spent-fuel transport casks, a large amount of memory may be necessary to store enough points to properly represent the source. Hence, we have developed an improved version of A 3 MCNP (referred to as A 3 MCNPV) which has a volumetric source configuration option. This paper describes the successful use of A 3 MCNPV for a concrete cask streaming problem and a PWR dosimetry problem. (author)

  12. 1/f and the Earthquake Problem: Scaling constraints that facilitate operational earthquake forecasting

    Science.gov (United States)

    yoder, M. R.; Rundle, J. B.; Turcotte, D. L.

    2012-12-01

    The difficulty of forecasting earthquakes can fundamentally be attributed to the self-similar, or "1/f", nature of seismic sequences. Specifically, the rate of occurrence of earthquakes is inversely proportional to their magnitude m, or more accurately to their scalar moment M. With respect to this "1/f problem," it can be argued that catalog selection (or equivalently, determining catalog constraints) constitutes the most significant challenge to seismicity based earthquake forecasting. Here, we address and introduce a potential solution to this most daunting problem. Specifically, we introduce a framework to constrain, or partition, an earthquake catalog (a study region) in order to resolve local seismicity. In particular, we combine Gutenberg-Richter (GR), rupture length, and Omori scaling with various empirical measurements to relate the size (spatial and temporal extents) of a study area (or bins within a study area) to the local earthquake magnitude potential - the magnitude of earthquake the region is expected to experience. From this, we introduce a new type of time dependent hazard map for which the tuning parameter space is nearly fully constrained. In a similar fashion, by combining various scaling relations and also by incorporating finite extents (rupture length, area, and duration) as constraints, we develop a method to estimate the Omori (temporal) and spatial aftershock decay parameters as a function of the parent earthquake's magnitude m. From this formulation, we develop an ETAS type model that overcomes many point-source limitations of contemporary ETAS. These models demonstrate promise with respect to earthquake forecasting applications. Moreover, the methods employed suggest a general framework whereby earthquake and other complex-system, 1/f type, problems can be constrained from scaling relations and finite extents.; Record-breaking hazard map of southern California, 2012-08-06. "Warm" colors indicate local acceleration (elevated hazard

  13. Characteristics-based modelling of flow problems

    International Nuclear Information System (INIS)

    Saarinen, M.

    1994-02-01

    The method of characteristics is an exact way to proceed to the solution of hyperbolic partial differential equations. The numerical solutions, however, are obtained in the fixed computational grid where interpolations of values between the mesh points cause numerical errors. The Piecewise Linear Interpolation Method, PLIM, the utilization of which is based on the method of characteristics, has been developed to overcome these deficiencies. The thesis concentrates on the computer simulation of the two-phase flow. The main topics studied are: (1) the PLIM method has been applied to study the validity of the numerical scheme through solving various flow problems to achieve knowledge for the further development of the method, (2) the mathematical and physical validity and applicability of the two-phase flow equations based on the SFAV (Separation of the two-phase Flow According to Velocities) approach has been studied, and (3) The SFAV approach has been further developed for particular cases such as stratified horizontal two-phase flow. (63 refs., 4 figs.)

  14. Evaluation of the multi-sums for large scale problems

    International Nuclear Information System (INIS)

    Bluemlein, J.; Hasselhuhn, A.; Schneider, C.

    2012-02-01

    A big class of Feynman integrals, in particular, the coefficients of their Laurent series expansion w.r.t. the dimension parameter ε can be transformed to multi-sums over hypergeometric terms and harmonic sums. In this article, we present a general summation method based on difference fields that simplifies these multi--sums by transforming them from inside to outside to representations in terms of indefinite nested sums and products. In particular, we present techniques that assist in the task to simplify huge expressions of such multi-sums in a completely automatic fashion. The ideas are illustrated on new calculations coming from 3-loop topologies of gluonic massive operator matrix elements containing two fermion lines, which contribute to the transition matrix elements in the variable flavor scheme. (orig.)

  15. Evaluation of the multi-sums for large scale problems

    Energy Technology Data Exchange (ETDEWEB)

    Bluemlein, J.; Hasselhuhn, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation

    2012-02-15

    A big class of Feynman integrals, in particular, the coefficients of their Laurent series expansion w.r.t. the dimension parameter {epsilon} can be transformed to multi-sums over hypergeometric terms and harmonic sums. In this article, we present a general summation method based on difference fields that simplifies these multi--sums by transforming them from inside to outside to representations in terms of indefinite nested sums and products. In particular, we present techniques that assist in the task to simplify huge expressions of such multi-sums in a completely automatic fashion. The ideas are illustrated on new calculations coming from 3-loop topologies of gluonic massive operator matrix elements containing two fermion lines, which contribute to the transition matrix elements in the variable flavor scheme. (orig.)

  16. Conformal-Based Surface Morphing and Multi-Scale Representation

    Directory of Open Access Journals (Sweden)

    Ka Chun Lam

    2014-05-01

    Full Text Available This paper presents two algorithms, based on conformal geometry, for the multi-scale representations of geometric shapes and surface morphing. A multi-scale surface representation aims to describe a 3D shape at different levels of geometric detail, which allows analyzing or editing surfaces at the global or local scales effectively. Surface morphing refers to the process of interpolating between two geometric shapes, which has been widely applied to estimate or analyze deformations in computer graphics, computer vision and medical imaging. In this work, we propose two geometric models for surface morphing and multi-scale representation for 3D surfaces. The basic idea is to represent a 3D surface by its mean curvature function, H, and conformal factor function λ, which uniquely determine the geometry of the surface according to Riemann surface theory. Once we have the (λ, H parameterization of the surface, post-processing of the surface can be done directly on the conformal parameter domain. In particular, the problem of multi-scale representations of shapes can be reduced to the signal filtering on the λ and H parameters. On the other hand, the surface morphing problem can be transformed to an interpolation process of two sets of (λ, H parameters. We test the proposed algorithms on 3D human face data and MRI-derived brain surfaces. Experimental results show that our proposed methods can effectively obtain multi-scale surface representations and give natural surface morphing results.

  17. Scaling Professional Problems of Teachers in Turkey with Paired Comparison Method

    Directory of Open Access Journals (Sweden)

    Yasemin Duygu ESEN

    2017-03-01

    Full Text Available In this study, teachers’ professional problems was investigated and the significance level of them was measured with the paired comparison method. The study was carried out in survey model. The study group consisted of 484 teachers working in public schools which are accredited by Ministry of National Education (MEB in Turkey. “The Teacher Professional Problems Survey” developed by the researchers was used as a data collection tool. In data analysis , the scaling method with the third conditional equation of Thurstone’s law of comparative judgement was used. According to the results of study, the teachers’ professional problems include teacher training and the quality of teacher, employee rights and financial problems, decrease of professional reputation, the problems with MEB policies, the problems with union activities, workload, the problems with administration in school, physical conditions and the lack of infrastructure, the problems with parents, the problems with students. According to teachers, the most significant problem is MEB educational policies. This is followed by decrease of professional reputation, physical conditions and the lack of infrastructure, the problems with students, employee rights and financial problems, the problems with administration in school, teacher training and the quality of teacher, the problems with parents, workload, and the problems with union activities. When teachers’ professional problems were analyzed seniority variable, there was little difference in scale values. While the teachers with 0-10 years experience consider decrease of professional reputation as the most important problem, the teachers with 11-45 years experience put the problems with MEB policies at the first place.

  18. Information filtering via a scaling-based function.

    Science.gov (United States)

    Qiu, Tian; Zhang, Zi-Ke; Chen, Guang

    2013-01-01

    Finding a universal description of the algorithm optimization is one of the key challenges in personalized recommendation. In this article, for the first time, we introduce a scaling-based algorithm (SCL) independent of recommendation list length based on a hybrid algorithm of heat conduction and mass diffusion, by finding out the scaling function for the tunable parameter and object average degree. The optimal value of the tunable parameter can be abstracted from the scaling function, which is heterogeneous for the individual object. Experimental results obtained from three real datasets, Netflix, MovieLens and RYM, show that the SCL is highly accurate in recommendation. More importantly, compared with a number of excellent algorithms, including the mass diffusion method, the original hybrid method, and even an improved version of the hybrid method, the SCL algorithm remarkably promotes the personalized recommendation in three other aspects: solving the accuracy-diversity dilemma, presenting a high novelty, and solving the key challenge of cold start problem.

  19. Case Problems for Problem-Based Pedagogical Approaches: A Comparative Analysis

    Science.gov (United States)

    Dabbagh, Nada; Dass, Susan

    2013-01-01

    A comparative analysis of 51 case problems used in five problem-based pedagogical models was conducted to examine whether there are differences in their characteristics and the implications of such differences on the selection and generation of ill-structured case problems. The five pedagogical models were: situated learning, goal-based scenario,…

  20. Problem-Based Learning and Problem-Solving Tools: Synthesis and Direction for Distributed Education Environments.

    Science.gov (United States)

    Friedman, Robert S.; Deek, Fadi P.

    2002-01-01

    Discusses how the design and implementation of problem-solving tools used in programming instruction are complementary with both the theories of problem-based learning (PBL), including constructivism, and the practices of distributed education environments. Examines how combining PBL, Web-based distributed education, and a problem-solving…

  1. Problem-Based Learning: Student Engagement, Learning and Contextualized Problem-Solving. Occasional Paper

    Science.gov (United States)

    Mossuto, Mark

    2009-01-01

    The adoption of problem-based learning as a teaching method in the advertising and public relations programs offered by the Business TAFE (Technical and Further Education) School at RMIT University is explored in this paper. The effect of problem-based learning on student engagement, student learning and contextualised problem-solving was…

  2. Problem-based Learning and Problem Finding Among University Graduate Students

    OpenAIRE

    Ankit, A, Ravankar; Shotaro, Imai; Michiyo, Shimamura; Go, Chiba; Taichi, Takasuka

    2017-01-01

    In recent years, problem-based learning (PBL) techniques have been gaining momentum in schools and university curricula around the world. The main advantage of the PBL method is that it promotes creative problem solving, improves cognition and enhances overall thought processes in learners. For most PBL-style programmes, problem solving is at the core, although the notion of problem discovery or problem finding is not seriously considered. In most cases, students are always presen...

  3. High scale parity invariance as a solution to the SUSY CP problem ...

    Indian Academy of Sciences (India)

    scale SUSY ДК model provides a solution to the CP problems of the MSSM. A minimal version of this .... the renormalizable seesaw model so that К-parity conservation remains automatic. Pramana – J. Phys., Vol ... from the Planck scale to ЪК in the squark sector is to split the third generation squarks slightly from the first two ...

  4. Decomposition and parallelization strategies for solving large-scale MDO problems

    Energy Technology Data Exchange (ETDEWEB)

    Grauer, M.; Eschenauer, H.A. [Research Center for Multidisciplinary Analyses and Applied Structural Optimization, FOMAAS, Univ. of Siegen (Germany)

    2007-07-01

    During previous years, structural optimization has been recognized as a useful tool within the discriptiones of engineering and economics. However, the optimization of large-scale systems or structures is impeded by an immense solution effort. This was the reason to start a joint research and development (R and D) project between the Institute of Mechanics and Control Engineering and the Information and Decision Sciences Institute within the Research Center for Multidisciplinary Analyses and Applied Structural Optimization (FOMAAS) on cluster computing for parallel and distributed solution of multidisciplinary optimization (MDO) problems based on the OpTiX-Workbench. Here the focus of attention will be put on coarsegrained parallelization and its implementation on clusters of workstations. A further point of emphasis was laid on the development of a parallel decomposition strategy called PARDEC, for the solution of very complex optimization problems which cannot be solved efficiently by sequential integrated optimization. The use of the OptiX-Workbench together with the FEM ground water simulation system FEFLOW is shown for a special water management problem. (orig.)

  5. An allometric scaling relation based on logistic growth of cities

    International Nuclear Information System (INIS)

    Chen, Yanguang

    2014-01-01

    Highlights: • An allometric scaling based on logistic process can be used to model urban growth. • The traditional allometry is based on exponential growth instead of logistic growth. • The exponential allometry represents a local scaling of urban growth. • The logistic allometry represents a global scaling of urban growth. • The exponential allometry is an approximation relation of the logistic allometry. - Abstract: The relationships between urban area and population size have been empirically demonstrated to follow the scaling law of allometric growth. This allometric scaling is based on exponential growth of city size and can be termed “exponential allometry”, which is associated with the concepts of fractals. However, both city population and urban area comply with the course of logistic growth rather than exponential growth. In this paper, I will present a new allometric scaling based on logistic growth to solve the above mentioned problem. The logistic growth is a process of replacement dynamics. Defining a pair of replacement quotients as new measurements, which are functions of urban area and population, we can derive an allometric scaling relation from the logistic processes of urban growth, which can be termed “logistic allometry”. The exponential allometric relation between urban area and population is the approximate expression of the logistic allometric equation when the city size is not large enough. The proper range of the allometric scaling exponent value is reconsidered through the logistic process. Then, a medium-sized city of Henan Province, China, is employed as an example to validate the new allometric relation. The logistic allometry is helpful for further understanding the fractal property and self-organized process of urban evolution in the right perspective

  6. Escript: Open Source Environment For Solving Large-Scale Geophysical Joint Inversion Problems in Python

    Science.gov (United States)

    Gross, Lutz; Altinay, Cihan; Fenwick, Joel; Smith, Troy

    2014-05-01

    The program package escript has been designed for solving mathematical modeling problems using python, see Gross et al. (2013). Its development and maintenance has been funded by the Australian Commonwealth to provide open source software infrastructure for the Australian Earth Science community (recent funding by the Australian Geophysical Observing System EIF (AGOS) and the AuScope Collaborative Research Infrastructure Scheme (CRIS)). The key concepts of escript are based on the terminology of spatial functions and partial differential equations (PDEs) - an approach providing abstraction from the underlying spatial discretization method (i.e. the finite element method (FEM)). This feature presents a programming environment to the user which is easy to use even for complex models. Due to the fact that implementations are independent from data structures simulations are easily portable across desktop computers and scalable compute clusters without modifications to the program code. escript has been successfully applied in a variety of applications including modeling mantel convection, melting processes, volcanic flow, earthquakes, faulting, multi-phase flow, block caving and mineralization (see Poulet et al. 2013). The recent escript release (see Gross et al. (2013)) provides an open framework for solving joint inversion problems for geophysical data sets (potential field, seismic and electro-magnetic). The strategy bases on the idea to formulate the inversion problem as an optimization problem with PDE constraints where the cost function is defined by the data defect and the regularization term for the rock properties, see Gross & Kemp (2013). This approach of first-optimize-then-discretize avoids the assemblage of the - in general- dense sensitivity matrix as used in conventional approaches where discrete programming techniques are applied to the discretized problem (first-discretize-then-optimize). In this paper we will discuss the mathematical framework for

  7. Error due to unresolved scales in estimation problems for atmospheric data assimilation

    Science.gov (United States)

    Janjic, Tijana

    The error arising due to unresolved scales in data assimilation procedures is examined. The problem of estimating the projection of the state of a passive scalar undergoing advection at a sequence of times is considered. The projection belongs to a finite- dimensional function space and is defined on the continuum. Using the continuum projection of the state of a passive scalar, a mathematical definition is obtained for the error arising due to the presence, in the continuum system, of scales unresolved by the discrete dynamical model. This error affects the estimation procedure through point observations that include the unresolved scales. In this work, two approximate methods for taking into account the error due to unresolved scales and the resulting correlations are developed and employed in the estimation procedure. The resulting formulas resemble the Schmidt-Kalman filter and the usual discrete Kalman filter, respectively. For this reason, the newly developed filters are called the Schmidt-Kalman filter and the traditional filter. In order to test the assimilation methods, a two- dimensional advection model with nonstationary spectrum was developed for passive scalar transport in the atmosphere. An analytical solution on the sphere was found depicting the model dynamics evolution. Using this analytical solution the model error is avoided, and the error due to unresolved scales is the only error left in the estimation problem. It is demonstrated that the traditional and the Schmidt- Kalman filter work well provided the exact covariance function of the unresolved scales is known. However, this requirement is not satisfied in practice, and the covariance function must be modeled. The Schmidt-Kalman filter cannot be computed in practice without further approximations. Therefore, the traditional filter is better suited for practical use. Also, the traditional filter does not require modeling of the full covariance function of the unresolved scales, but only

  8. AI tools in computer based problem solving

    Science.gov (United States)

    Beane, Arthur J.

    1988-01-01

    The use of computers to solve value oriented, deterministic, algorithmic problems, has evolved a structured life cycle model of the software process. The symbolic processing techniques used, primarily in research, for solving nondeterministic problems, and those for which an algorithmic solution is unknown, have evolved a different model, much less structured. Traditionally, the two approaches have been used completely independently. With the advent of low cost, high performance 32 bit workstations executing identical software with large minicomputers and mainframes, it became possible to begin to merge both models into a single extended model of computer problem solving. The implementation of such an extended model on a VAX family of micro/mini/mainframe systems is described. Examples in both development and deployment of applications involving a blending of AI and traditional techniques are given.

  9. Multi scales based sparse matrix spectral clustering image segmentation

    Science.gov (United States)

    Liu, Zhongmin; Chen, Zhicai; Li, Zhanming; Hu, Wenjin

    2018-04-01

    In image segmentation, spectral clustering algorithms have to adopt the appropriate scaling parameter to calculate the similarity matrix between the pixels, which may have a great impact on the clustering result. Moreover, when the number of data instance is large, computational complexity and memory use of the algorithm will greatly increase. To solve these two problems, we proposed a new spectral clustering image segmentation algorithm based on multi scales and sparse matrix. We devised a new feature extraction method at first, then extracted the features of image on different scales, at last, using the feature information to construct sparse similarity matrix which can improve the operation efficiency. Compared with traditional spectral clustering algorithm, image segmentation experimental results show our algorithm have better degree of accuracy and robustness.

  10. Incorporating Problem-Based Learning in Physical Education Teacher Education

    Science.gov (United States)

    Hushman, Glenn; Napper-Owen, Gloria

    2011-01-01

    Problem-based learning (PBL) is an educational method that identifies a problem as a context for student learning. Critical-thinking skills, deductive reasoning, knowledge, and behaviors are developed as students learn how theory can be applied to practical settings. Problem-based learning encourages self-direction, lifelong learning, and sharing…

  11. 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…

  12. Regularization methods for ill-posed problems in multiple Hilbert scales

    International Nuclear Information System (INIS)

    Mazzieri, Gisela L; Spies, Ruben D

    2012-01-01

    Several convergence results in Hilbert scales under different source conditions are proved and orders of convergence and optimal orders of convergence are derived. Also, relations between those source conditions are proved. The concept of a multiple Hilbert scale on a product space is introduced, and regularization methods on these scales are defined, both for the case of a single observation and for the case of multiple observations. In the latter case, it is shown how vector-valued regularization functions in these multiple Hilbert scales can be used. In all cases, convergence is proved and orders and optimal orders of convergence are shown. Finally, some potential applications and open problems are discussed. (paper)

  13. Methods and scales in soil erosion studies in Spain: problems and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Ruiz, J. M.

    2009-07-01

    Soil erosion is a major problem in some areas of Spain. Research groups have studied a variety of aspects of this problem indifferent environments, and at a range of scales using a diversity of methods, from piquettes and rainfall simulation to experimental plots, catchment and large regional areas. This has increased knowledge and identified the main problems: farmland abandonment, badlands erosion, the effects of land use changes, and the role of extreme events and erosion in certain crops (particularly vineyards). However, comparison of results among various research groups has been difficult, posing problems in developing solutions from State and Regional administrators. (Author) 73 refs.

  14. Development of internalizing problems from adolescence to emerging adulthood: Accounting for heterotypic continuity with vertical scaling.

    Science.gov (United States)

    Petersen, Isaac T; Lindhiem, Oliver; LeBeau, Brandon; Bates, John E; Pettit, Gregory S; Lansford, Jennifer E; Dodge, Kenneth A

    2018-03-01

    Manifestations of internalizing problems, such as specific symptoms of anxiety and depression, can change across development, even if individuals show strong continuity in rank-order levels of internalizing problems. This illustrates the concept of heterotypic continuity, and raises the question of whether common measures might be construct-valid for one age but not another. This study examines mean-level changes in internalizing problems across a long span of development at the same time as accounting for heterotypic continuity by using age-appropriate, changing measures. Internalizing problems from age 14-24 were studied longitudinally in a community sample (N = 585), using Achenbach's Youth Self-Report (YSR) and Young Adult Self-Report (YASR). Heterotypic continuity was evaluated with an item response theory (IRT) approach to vertical scaling, linking different measures over time to be on the same scale, as well as with a Thurstone scaling approach. With vertical scaling, internalizing problems peaked in mid-to-late adolescence and showed a group-level decrease from adolescence to early adulthood, a change that would not have been seen with the approach of using only age-common items. Individuals' trajectories were sometimes different than would have been seen with the common-items approach. Findings support the importance of considering heterotypic continuity when examining development and vertical scaling to account for heterotypic continuity with changing measures. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  15. Mapping Students Use of Technologies in Problem Based Learning Environments

    DEFF Research Database (Denmark)

    Rongbutsri, Nikorn; Khalid, Md. Saifuddin; Ryberg, Thomas

    2011-01-01

    This paper aims to understand how students use technology to enhance their learning in problem-based learning environments. The research methodology is based on both qualitative and quantitative studies. The results are based on students’ interviews, a survey and students’ reflections in course......-related blog posts; they show that students have positive perceptions toward using technologies in problem-based learning environments....

  16. Introducing problem-based learning (PBL) into a foundation ...

    African Journals Online (AJOL)

    second chance learners they cannot be taught by the same traditional methods that ... a shift from content coverage to problem engagement; from lecturing to coaching; and ..... Project on the effectiveness of Problem Based Learning (PBL).

  17. An allometric scaling relation based on logistic growth of cities

    Science.gov (United States)

    Chen, Yanguang

    2014-08-01

    The relationships between urban area and population size have been empirically demonstrated to follow the scaling law of allometric growth. This allometric scaling is based on exponential growth of city size and can be termed "exponential allometry", which is associated with the concepts of fractals. However, both city population and urban area comply with the course of logistic growth rather than exponential growth. In this paper, I will present a new allometric scaling based on logistic growth to solve the abovementioned problem. The logistic growth is a process of replacement dynamics. Defining a pair of replacement quotients as new measurements, which are functions of urban area and population, we can derive an allometric scaling relation from the logistic processes of urban growth, which can be termed "logistic allometry". The exponential allometric relation between urban area and population is the approximate expression of the logistic allometric equation when the city size is not large enough. The proper range of the allometric scaling exponent value is reconsidered through the logistic process. Then, a medium-sized city of Henan Province, China, is employed as an example to validate the new allometric relation. The logistic allometry is helpful for further understanding the fractal property and self-organized process of urban evolution in the right perspective.

  18. Credit Scoring Problem Based on Regression Analysis

    OpenAIRE

    Khassawneh, Bashar Suhil Jad Allah

    2014-01-01

    ABSTRACT: This thesis provides an explanatory introduction to the regression models of data mining and contains basic definitions of key terms in the linear, multiple and logistic regression models. Meanwhile, the aim of this study is to illustrate fitting models for the credit scoring problem using simple linear, multiple linear and logistic regression models and also to analyze the found model functions by statistical tools. Keywords: Data mining, linear regression, logistic regression....

  19. EFFECT OF PROBLEM BASED LEARNING AND MODEL CRITICAL THINKING ABILITY TO PROBLEM SOLVING SKILLS

    Directory of Open Access Journals (Sweden)

    Unita S. Zuliani Nasution

    2016-12-01

    Full Text Available The purposes of this research were to analyze the different between physic resolving problem ability by using problem based learning model and direct instruction model, the different of physic resolving problem ability between the students that have critical thinking ability upper the average and the students that have critical thinking ability under the average, and the interaction of problem based learning model toward critical thinking ability and students’ physic resolving problem ability. This research was quasy experimental research that use critical thinking ability tests and physic resolving problem ability tests as the instruments. Result of the research showed that the students’ physic resolving problem ability by using problem based learning model was better than by using direct instruction model, students’ physic resolving problem ability and critical thinking ability upper the average showed better different and result than students’ critical thinking ability under the average, besides there was an interaction between problem based learning model and critical thinking ability in improving students’ physic resolving problem ability.

  20. Solving Large Scale Nonlinear Eigenvalue Problem in Next-Generation Accelerator Design

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Ben-Shan; Bai, Zhaojun; /UC, Davis; Lee, Lie-Quan; Ko, Kwok; /SLAC

    2006-09-28

    A number of numerical methods, including inverse iteration, method of successive linear problem and nonlinear Arnoldi algorithm, are studied in this paper to solve a large scale nonlinear eigenvalue problem arising from finite element analysis of resonant frequencies and external Q{sub e} values of a waveguide loaded cavity in the next-generation accelerator design. They present a nonlinear Rayleigh-Ritz iterative projection algorithm, NRRIT in short and demonstrate that it is the most promising approach for a model scale cavity design. The NRRIT algorithm is an extension of the nonlinear Arnoldi algorithm due to Voss. Computational challenges of solving such a nonlinear eigenvalue problem for a full scale cavity design are outlined.

  1. Engineering large-scale agent-based systems with consensus

    Science.gov (United States)

    Bokma, A.; Slade, A.; Kerridge, S.; Johnson, K.

    1994-01-01

    The paper presents the consensus method for the development of large-scale agent-based systems. Systems can be developed as networks of knowledge based agents (KBA) which engage in a collaborative problem solving effort. The method provides a comprehensive and integrated approach to the development of this type of system. This includes a systematic analysis of user requirements as well as a structured approach to generating a system design which exhibits the desired functionality. There is a direct correspondence between system requirements and design components. The benefits of this approach are that requirements are traceable into design components and code thus facilitating verification. The use of the consensus method with two major test applications showed it to be successful and also provided valuable insight into problems typically associated with the development of large systems.

  2. New Evidence of Construct Validity Problems for Pettigrew and Meertens' (1995) Blatant and Subtle Prejudice Scale.

    Science.gov (United States)

    Arancibia-Martini, Héctor; Ruiz, Miguel Á; Blanco, Amalio; Cárdenas, Manuel

    2016-04-01

    Given the current debate over the distinction between subtle and blatant prejudice, this study provides new evidence regarding problems with the construct validity of the Pettigrew and Meertens' Blatant and Subtle Prejudice Scale. To assess these issues, an existing data sample of 896 Chilean participants collected in 2010 was reanalyzed. The main analysis method used was a confirmatory factor analysis. The model that best represented the original theory (a model of two correlated second-order factors) had an improper solution due to the unidentified model. The scale has substantial psychometric problems, and it was not possible to distinguish between subtle and blatant prejudice. © The Author(s) 2016.

  3. Small Scale Problems of the ΛCDM Model: A Short Review

    Directory of Open Access Journals (Sweden)

    Antonino Del Popolo

    2017-02-01

    Full Text Available The ΛCDM model, or concordance cosmology, as it is often called, is a paradigm at its maturity. It is clearly able to describe the universe at large scale, even if some issues remain open, such as the cosmological constant problem, the small-scale problems in galaxy formation, or the unexplained anomalies in the CMB. ΛCDM clearly shows difficulty at small scales, which could be related to our scant understanding, from the nature of dark matter to that of gravity; or to the role of baryon physics, which is not well understood and implemented in simulation codes or in semi-analytic models. At this stage, it is of fundamental importance to understand whether the problems encountered by the ΛDCM model are a sign of its limits or a sign of our failures in getting the finer details right. In the present paper, we will review the small-scale problems of the ΛCDM model, and we will discuss the proposed solutions and to what extent they are able to give us a theory accurately describing the phenomena in the complete range of scale of the observed universe.

  4. The Problem Behaviour Check List: a short scale to assess challenging behaviours

    OpenAIRE

    Tyrer, PJ; Nagar, J; Evans, R; Oliver, P; Bassett, P; Liedtka, N; Tarabi, A

    2016-01-01

    Background Challenging behaviour, especially in intellectual disability, covers a wide range that is in need of further evaluation. Aims To develop a short but comprehensive instrument for all aspects of challenging behaviour. Method In the first part of a two-stage enquiry, a 28-item scale was constructed to examine the components of challenging behaviour. Following a simple factor analysis this was developed further to create a new short scale, the Problem Behaviour Checklist (PBCL). The sc...

  5. Planck-scale physics and solutions to the strong CP-problem without axion

    International Nuclear Information System (INIS)

    Berezhiani, Z.G.; Mohapatra, R.N.; Senjanovic, G.

    1992-12-01

    We analyse the impact of quantum gravity on the possible solutions to the strong CP problem which utilize the spontaneously broken discrete symmetries, such as parity and time reversal invariance. We find that the stability of the solution under Planck scale effects provides an upper limit on the scale Λ of relevant symmetry breaking. This result is mode dependent and the bound is most restrictive for the seesaw type models of fermion masses, with Λ 6 GeV. (author). 32 refs

  6. The multilevel fast multipole algorithm (MLFMA) for solving large-scale computational electromagnetics problems

    CERN Document Server

    Ergul, Ozgur

    2014-01-01

    The Multilevel Fast Multipole Algorithm (MLFMA) for Solving Large-Scale Computational Electromagnetic Problems provides a detailed and instructional overview of implementing MLFMA. The book: Presents a comprehensive treatment of the MLFMA algorithm, including basic linear algebra concepts, recent developments on the parallel computation, and a number of application examplesCovers solutions of electromagnetic problems involving dielectric objects and perfectly-conducting objectsDiscusses applications including scattering from airborne targets, scattering from red

  7. Junior High School Students’ Perception about Simple Environmental Problem as an Impact of Problem based Learning

    Science.gov (United States)

    Tapilouw, M. C.; Firman, H.; Redjeki, S.; Chandra, D. T.

    2017-09-01

    Environmental problem is a real problem that occur in student’s daily life. Junior high school students’ perception about environmental problem is interesting to be investigated. The major aim of this study is to explore junior high school students’ perception about environmental problems around them and ways to solve the problem. The subject of this study is 69 Junior High School Students from two Junior High School in Bandung. This study use two open ended question. The core of first question is environmental problem around them (near school or house). The core of second question is the way to prevent or to solve the problem. These two question are as an impact of problem based learning in science learning. There are two major findings in this study. The first finding, based on most students’ perception, plastic waste cause an environmental problem. The second finding, environmental awareness can be a solution to prevent environmental pollution. The third finding, most student can classify environmental pollution into land, water and air pollution. We can conclude that Junior High School Students see the environmental problem as a phenomenon and teacher can explore environmental problem to guide the way of preventing and resolving environmental problem.

  8. Problem Based Learning: Application to Technology Education in Three Countries

    Science.gov (United States)

    Williams, P. John; Iglesias, Juan; Barak, Moshe

    2008-01-01

    An increasing variety of professional educational and training disciplines are now problem based (e.g., medicine, nursing, engineering, community health), and they may have a corresponding variety of educational objectives. However, they all have in common the use of problems in the instructional sequence. The problems may be as diverse as a…

  9. Facilitating Problem Framing in Project-Based Learning

    Science.gov (United States)

    Svihla, Vanessa; Reeve, Richard

    2016-01-01

    While problem solving is a relatively well understood process, problem framing is less well understood, particularly with regard to supporting students to learn as they frame problems. Project-based learning classrooms are an ideal setting to investigate how teachers facilitate this process. Using participant observation, this study investigated…

  10. Solving a large-scale precedence constrained scheduling problem with elastic jobs using tabu search

    DEFF Research Database (Denmark)

    Pedersen, C.R.; Rasmussen, R.V.; Andersen, Kim Allan

    2007-01-01

    exploitation of the elastic jobs and solve the problem using a tabu search procedure. Finding an initial feasible solution is in general -complete, but the tabu search procedure includes a specialized heuristic for solving this problem. The solution method has proven to be very efficient and leads......This paper presents a solution method for minimizing makespan of a practical large-scale scheduling problem with elastic jobs. The jobs are processed on three servers and restricted by precedence constraints, time windows and capacity limitations. We derive a new method for approximating the server...... to a significant decrease in makespan compared to the strategy currently implemented....

  11. Solving a large-scale precedence constrained scheduling problem with elastic jobs using tabu search

    DEFF Research Database (Denmark)

    Pedersen, C.R.; Rasmussen, R.V.; Andersen, Kim Allan

    2007-01-01

    This paper presents a solution method for minimizing makespan of a practical large-scale scheduling problem with elastic jobs. The jobs are processed on three servers and restricted by precedence constraints, time windows and capacity limitations. We derive a new method for approximating the server...... exploitation of the elastic jobs and solve the problem using a tabu search procedure. Finding an initial feasible solution is in general -complete, but the tabu search procedure includes a specialized heuristic for solving this problem. The solution method has proven to be very efficient and leads...

  12. Nano-scaled chalcogenide-based memories

    International Nuclear Information System (INIS)

    Redaelli, Andrea; Pirovano, Agostino

    2011-01-01

    Today phase change memory (PCM) technology has reached product maturity at 90 and 65 nm nodes, while the 45 nm node is under development and is expected to enter in the market soon. The continuous decrease of the cell size with scaling leads to an effective active area as small as 150 nm 2 and an active volume involved in the phase transformation of about 10 4 nm 3 , thus entering definitively into the nanotechnology world. At this extremely reduced dimension, the reliability of the device must be carefully investigated. In this work we show that the cycling performance of the device is well maintained, not being a problem for either the bipolar transistor or the storage element. The phase transition from the amorphous to the crystalline state is, of course, one of the most interesting phenomena, impacting cell retention capability and device performance. The stochastic nature of nano-nuclei percolation in the amorphous matrix is shown as an important ingredient in the retention of PCM devices. The related dispersion in crystallization times is analyzed through a crystallization Monte Carlo model and a physical insight into nucleation and growth mechanisms is provided.

  13. Solving SAT Problem Based on Hybrid Differential Evolution Algorithm

    Science.gov (United States)

    Liu, Kunqi; Zhang, Jingmin; Liu, Gang; Kang, Lishan

    Satisfiability (SAT) problem is an NP-complete problem. Based on the analysis about it, SAT problem is translated equally into an optimization problem on the minimum of objective function. A hybrid differential evolution algorithm is proposed to solve the Satisfiability problem. It makes full use of strong local search capacity of hill-climbing algorithm and strong global search capability of differential evolution algorithm, which makes up their disadvantages, improves the efficiency of algorithm and avoids the stagnation phenomenon. The experiment results show that the hybrid algorithm is efficient in solving SAT problem.

  14. Advantages of video trigger in problem-based learning.

    Science.gov (United States)

    Chan, Lap Ki; Patil, Nivritti G; Chen, Julie Y; Lam, Jamie C M; Lau, Chak S; Ip, Mary S M

    2010-01-01

    Traditionally, paper cases are used as 'triggers' to stimulate learning in problem-based learning (PBL). However, video may be a better medium because it preserves the original language, encourages the active extraction of information, avoids depersonalization of patients and allows direct observation of clinical consultations. In short, it exposes the students to the complexity of actual clinical problems. The study aims to find out whether students and facilitators who are accustomed to paper cases would prefer video triggers or paper cases and the reasons for their preference. After students and facilitators had completed a video PBL tutorial, their responses were measured by a structured questionnaire using a modified Likert scale. A total of 257 students (92%) and 26 facilitators (100%) responded. The majority of students and facilitators considered that using video triggers could enhance the students' observational powers and clinical reasoning, help them to integrate different information and better understand the cases and motivate them to learn. They found PBL using video triggers more interesting and preferred it to PBL using paper cases. Video triggers are preferred by both students and facilitators over paper cases in PBL.

  15. Large scale inverse problems computational methods and applications in the earth sciences

    CERN Document Server

    Scheichl, Robert; Freitag, Melina A; Kindermann, Stefan

    2013-01-01

    This book is thesecond volume of three volume series recording the ""Radon Special Semester 2011 on Multiscale Simulation & Analysis in Energy and the Environment"" taking place in Linz, Austria, October 3-7, 2011. The volume addresses the common ground in the mathematical and computational procedures required for large-scale inverse problems and data assimilation in forefront applications.

  16. Psychometric properties of the Fatigue Assessment Scale (FAS) in women with breast problems

    NARCIS (Netherlands)

    de Vries, J.; van der Steeg, A.F.; Roukema, J.A.

    2010-01-01

    To examine the usefulness of the Fatigue Assessment Scale (FAS) in women with benign breast problems (BBP) and women with early stage breast cancer (BC). Women with a palpable lump in the breast or an abnormality on a screening mammography (N = 560) completed the FAS (four time points) and measures

  17. Knowledge formations in Problem Based Learning

    DEFF Research Database (Denmark)

    Larsen, Verner

    organization are no longer based on relationships between strong independent disciplines, but rather on a number of ‘themes’ or ‘subject areas’ that should be combined and tied together during the students PBL-studies. As such, the curriculum organized knowledge, as well as student’s reflections of various...

  18. A New Likert Scale Based on Fuzzy Sets Theory

    Science.gov (United States)

    Li, Cheryl Qing

    2010-01-01

    In social science research, the Likert method is commonly used as a psychometric scale to measure responses. This measurement scale has a procedure that facilitates survey construction and administration, and data coding and analysis. However, there are some problems with Likert scaling. This dissertation addresses the information distortion and…

  19. A novel artificial fish swarm algorithm for solving large-scale reliability-redundancy application problem.

    Science.gov (United States)

    He, Qiang; Hu, Xiangtao; Ren, Hong; Zhang, Hongqi

    2015-11-01

    A novel artificial fish swarm algorithm (NAFSA) is proposed for solving large-scale reliability-redundancy allocation problem (RAP). In NAFSA, the social behaviors of fish swarm are classified in three ways: foraging behavior, reproductive behavior, and random behavior. The foraging behavior designs two position-updating strategies. And, the selection and crossover operators are applied to define the reproductive ability of an artificial fish. For the random behavior, which is essentially a mutation strategy, the basic cloud generator is used as the mutation operator. Finally, numerical results of four benchmark problems and a large-scale RAP are reported and compared. NAFSA shows good performance in terms of computational accuracy and computational efficiency for large scale RAP. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Facilitating Change to a Problem-based Model

    DEFF Research Database (Denmark)

    Kolmos, Anette

    2002-01-01

    The paper presents the barriers which arise during the change process from a traditional educational system to a problem-based educational model.......The paper presents the barriers which arise during the change process from a traditional educational system to a problem-based educational model....

  1. Investigative Primary Science: A Problem-Based Learning Approach

    Science.gov (United States)

    Etherington, Matthew B.

    2011-01-01

    This study reports on the success of using a problem-based learning approach (PBL) as a pedagogical mode of learning open inquiry science within a traditional four-year undergraduate elementary teacher education program. In 2010, a problem-based learning approach to teaching primary science replaced the traditional content driven syllabus. During…

  2. Effectiveness of problem-based learning among student nurses: A ...

    African Journals Online (AJOL)

    The purpose of this review is to analyze available literature from 2005 to 2012 on the effectiveness of problem based learning among the nursing students. Twenty articles that discussed problem based learning among nurses and those that discussed nursing with other allied health were included as meeting the criteria for ...

  3. What Is the Problem in Problem-Based Learning in Higher Education Mathematics

    Science.gov (United States)

    Dahl, Bettina

    2018-01-01

    Problem and Project-Based Learning (PBL) emphasise collaborate work on problems relevant to society and emphases the relation between theory and practice. PBL fits engineering students as preparation for their future professions but what about mathematics? Mathematics is not just applied mathematics, but it is also a body of abstract knowledge…

  4. Developing and validating the Youth Conduct Problems Scale-Rwanda: a mixed methods approach.

    Directory of Open Access Journals (Sweden)

    Lauren C Ng

    Full Text Available This study developed and validated the Youth Conduct Problems Scale-Rwanda (YCPS-R. Qualitative free listing (n = 74 and key informant interviews (n = 47 identified local conduct problems, which were compared to existing standardized conduct problem scales and used to develop the YCPS-R. The YCPS-R was cognitive tested by 12 youth and caregiver participants, and assessed for test-retest and inter-rater reliability in a sample of 64 youth. Finally, a purposive sample of 389 youth and their caregivers were enrolled in a validity study. Validity was assessed by comparing YCPS-R scores to conduct disorder, which was diagnosed with the Mini International Neuropsychiatric Interview for Children, and functional impairment scores on the World Health Organization Disability Assessment Schedule Child Version. ROC analyses assessed the YCPS-R's ability to discriminate between youth with and without conduct disorder. Qualitative data identified a local presentation of youth conduct problems that did not match previously standardized measures. Therefore, the YCPS-R was developed solely from local conduct problems. Cognitive testing indicated that the YCPS-R was understandable and required little modification. The YCPS-R demonstrated good reliability, construct, criterion, and discriminant validity, and fair classification accuracy. The YCPS-R is a locally-derived measure of Rwandan youth conduct problems that demonstrated good psychometric properties and could be used for further research.

  5. Constraint-based scheduling applying constraint programming to scheduling problems

    CERN Document Server

    Baptiste, Philippe; Nuijten, Wim

    2001-01-01

    Constraint Programming is a problem-solving paradigm that establishes a clear distinction between two pivotal aspects of a problem: (1) a precise definition of the constraints that define the problem to be solved and (2) the algorithms and heuristics enabling the selection of decisions to solve the problem. It is because of these capabilities that Constraint Programming is increasingly being employed as a problem-solving tool to solve scheduling problems. Hence the development of Constraint-Based Scheduling as a field of study. The aim of this book is to provide an overview of the most widely used Constraint-Based Scheduling techniques. Following the principles of Constraint Programming, the book consists of three distinct parts: The first chapter introduces the basic principles of Constraint Programming and provides a model of the constraints that are the most often encountered in scheduling problems. Chapters 2, 3, 4, and 5 are focused on the propagation of resource constraints, which usually are responsibl...

  6. Enhancement of a model for Large-scale Airline Network Planning Problems

    NARCIS (Netherlands)

    Kölker, K.; Lopes dos Santos, Bruno F.; Lütjens, K.

    2016-01-01

    The main focus of this study is to solve the network planning problem based on passenger decision criteria including the preferred departure time and travel time for a real-sized airline network. For this purpose, a model of the integrated network planning problem is formulated including scheduling

  7. Hierarchy problem, gauge coupling unification at the Planck scale, and vacuum stability

    Directory of Open Access Journals (Sweden)

    Naoyuki Haba

    2015-11-01

    Full Text Available From the point of view of the gauge hierarchy problem, introducing an intermediate scale in addition to TeV scale and the Planck scale (MPl=2.4×1018 GeV is unfavorable. In that way, a gauge coupling unification (GCU is expected to be realized at MPl. We explore possibilities of GCU at MPl by adding a few extra particles with TeV scale mass into the standard model (SM. When extra particles are fermions and scalars (only fermions with the same mass, the GCU at MPl can (not be realized. On the other hand, when extra fermions have different masses, the GCU can be realized around 8πMPl without extra scalars. This simple SM extension has two advantages that a vacuum becomes stable up to MPl (8πMPl and a proton lifetime becomes much longer than an experimental bound.

  8. Problem based review: The patient taking methadone.

    Science.gov (United States)

    Arora, Alok; Williams, Karen

    2013-01-01

    Methadone maintenance treatment (MMT) is an effective therapy for opioid-dependence; its use is based on a harm reduction philosophy and represents one of a range of treatment approaches for opioid-dependent individuals. The medical literature supports MMT as a well established and cost-effective treatment for opioid-dependence that allows a return-to-normal physiological, psychological and societal functioning. The effectiveness of MMT is enhanced by psycho-social interventions such as contingency management and addressing other co-existing health and social needs. MMT saves lives and reduces violent and non-violent crime, drug use and the transmission of HIV, hepatitis C and other communicable diseases. For some people, MMT may continue for life, while others may eventually be able to discontinue and remain abstinent. Methadone interacts with numerous drugs and prolongs the corrected QT interval (QTc) with risk of sudden cardiac death. It has a prolonged half-life and premature discharge of patients after methadone overdose may be fatal. Each patient must be assessed, treated and monitored on an individual basis. Successful outcomes through MMT require knowledge, experience, vigilance, and diligence on the part of the physician, the patient and all of those involved in treatment.

  9. Students’ Mathematical Problem-Solving Abilities Through The Application of Learning Models Problem Based Learning

    Science.gov (United States)

    Nasution, M. L.; Yerizon, Y.; Gusmiyanti, R.

    2018-04-01

    One of the purpose mathematic learning is to develop problem solving abilities. Problem solving is obtained through experience in questioning non-routine. Improving students’ mathematical problem-solving abilities required an appropriate strategy in learning activities one of them is models problem based learning (PBL). Thus, the purpose of this research is to determine whether the problem solving abilities of mathematical students’ who learn to use PBL better than on the ability of students’ mathematical problem solving by applying conventional learning. This research included quasi experiment with static group design and population is students class XI MIA SMAN 1 Lubuk Alung. Class experiment in the class XI MIA 5 and class control in the class XI MIA 6. The instrument of final test students’ mathematical problem solving used essay form. The result of data final test in analyzed with t-test. The result is students’ mathematical problem solving abilities with PBL better then on the ability of students’ mathematical problem solving by applying conventional learning. It’s seen from the high percentage achieved by the group of students who learn to use PBL for each indicator of students’ mathematical problem solving.

  10. Problem-based learning in internal medicine: virtual patients or paper-based problems?

    Science.gov (United States)

    Sobocan, Monika; Turk, Neja; Dinevski, Dejan; Hojs, Radovan; Pecovnik Balon, Breda

    2017-01-01

    Teaching using paper problem-based learning (p-PBL) sessions has left some students fatigued with the learning process. Therefore, attempts have been made to replace p-PBL with digitally enhanced, decision-making PBL in the form of virtual patients (VP). Student enthusiasm for substituting p-PBL with VP has not been quantitatively evaluated on the intended educational effects. To determine the educational effects of substituting p-PBL sessions with VP on undergraduate medical students in their internal medicine course. We conducted a randomised controlled study on 34 third-year undergraduate medical students in the academic year 2015-2016. Student performance after an intervention substituting p-PBL sessions with VP was analysed. The educational outcomes were measured with knowledge exams and the Diagnostic Thinking Inventory. There was no difference in exam performance between groups (P > 0.833) immediately after the intervention, or in long term. Nor was there a significant difference in improvement of diagnostic thinking between groups (P > 0.935 and P > 0.320). Our study showed no significant improvement in diagnostic thinking abilities or knowledge exam results with the use of VP. Educators can add VP to sessions to motivate students, but a significant improvement to educational outcome should not be expected. © 2016 Royal Australasian College of Physicians.

  11. Facing the scaling problem: A multi-methodical approach to simulate soil erosion at hillslope and catchment scale

    Science.gov (United States)

    Schmengler, A. C.; Vlek, P. L. G.

    2012-04-01

    Modelling soil erosion requires a holistic understanding of the sediment dynamics in a complex environment. As most erosion models are scale-dependent and their parameterization is spatially limited, their application often requires special care, particularly in data-scarce environments. This study presents a hierarchical approach to overcome the limitations of a single model by using various quantitative methods and soil erosion models to cope with the issues of scale. At hillslope scale, the physically-based Water Erosion Prediction Project (WEPP)-model is used to simulate soil loss and deposition processes. Model simulations of soil loss vary between 5 to 50 t ha-1 yr-1 dependent on the spatial location on the hillslope and have only limited correspondence with the results of the 137Cs technique. These differences in absolute soil loss values could be either due to internal shortcomings of each approach or to external scale-related uncertainties. Pedo-geomorphological soil investigations along a catena confirm that estimations by the 137Cs technique are more appropriate in reflecting both the spatial extent and magnitude of soil erosion at hillslope scale. In order to account for sediment dynamics at a larger scale, the spatially-distributed WaTEM/SEDEM model is used to simulate soil erosion at catchment scale and to predict sediment delivery rates into a small water reservoir. Predicted sediment yield rates are compared with results gained from a bathymetric survey and sediment core analysis. Results show that specific sediment rates of 0.6 t ha-1 yr-1 by the model are in close agreement with observed sediment yield calculated from stratigraphical changes and downcore variations in 137Cs concentrations. Sediment erosion rates averaged over the entire catchment of 1 to 2 t ha-1 yr-1 are significantly lower than results obtained at hillslope scale confirming an inverse correlation between the magnitude of erosion rates and the spatial scale of the model. The

  12. Effects of Smart-Tablet-Based Neurofeedback Training on Cognitive Function in Children with Attention Problems.

    Science.gov (United States)

    Shin, Min-Sup; Jeon, Hyejin; Kim, Miyoung; Hwang, Taeho; Oh, Seo Jin; Hwangbo, Minsu; Kim, Ki Joong

    2016-05-01

    We sought to determine whether smart-tablet-based neurofeedback could improve executive function-including attention, working memory, and self-regulation-in children with attention problems. Forty children (10-12 years old) with attention problems, as determined by ratings on the Conners Parent Rating Scale, were assigned to either a neurofeedback group that received 16 sessions or a control group. A comprehensive test battery that assessed general intelligence, visual and auditory attention, attentional shifting, response inhibition and behavior rating scales were administered to both groups before neurofeedback training. Several neuropsychological tests were conducted at posttraining and follow-up assessment. Scores on several neuropsychological tests and parent behavior rating scales showed significant improvement in the training group but not in the controls. The improvements remained through the follow-up assessment. This study suggests that the smart-tablet-based neurofeedback training program might improve cognitive function in children with attention problems. © The Author(s) 2015.

  13. Efficient numerical methods for the large-scale, parallel solution of elastoplastic contact problems

    KAUST Repository

    Frohne, Jörg

    2015-08-06

    © 2016 John Wiley & Sons, Ltd. Quasi-static elastoplastic contact problems are ubiquitous in many industrial processes and other contexts, and their numerical simulation is consequently of great interest in accurately describing and optimizing production processes. The key component in these simulations is the solution of a single load step of a time iteration. From a mathematical perspective, the problems to be solved in each time step are characterized by the difficulties of variational inequalities for both the plastic behavior and the contact problem. Computationally, they also often lead to very large problems. In this paper, we present and evaluate a complete set of methods that are (1) designed to work well together and (2) allow for the efficient solution of such problems. In particular, we use adaptive finite element meshes with linear and quadratic elements, a Newton linearization of the plasticity, active set methods for the contact problem, and multigrid-preconditioned linear solvers. Through a sequence of numerical experiments, we show the performance of these methods. This includes highly accurate solutions of a three-dimensional benchmark problem and scaling our methods in parallel to 1024 cores and more than a billion unknowns.

  14. Efficient numerical methods for the large-scale, parallel solution of elastoplastic contact problems

    KAUST Repository

    Frohne, Jö rg; Heister, Timo; Bangerth, Wolfgang

    2015-01-01

    © 2016 John Wiley & Sons, Ltd. Quasi-static elastoplastic contact problems are ubiquitous in many industrial processes and other contexts, and their numerical simulation is consequently of great interest in accurately describing and optimizing production processes. The key component in these simulations is the solution of a single load step of a time iteration. From a mathematical perspective, the problems to be solved in each time step are characterized by the difficulties of variational inequalities for both the plastic behavior and the contact problem. Computationally, they also often lead to very large problems. In this paper, we present and evaluate a complete set of methods that are (1) designed to work well together and (2) allow for the efficient solution of such problems. In particular, we use adaptive finite element meshes with linear and quadratic elements, a Newton linearization of the plasticity, active set methods for the contact problem, and multigrid-preconditioned linear solvers. Through a sequence of numerical experiments, we show the performance of these methods. This includes highly accurate solutions of a three-dimensional benchmark problem and scaling our methods in parallel to 1024 cores and more than a billion unknowns.

  15. Information filtering via a scaling-based function.

    Directory of Open Access Journals (Sweden)

    Tian Qiu

    Full Text Available Finding a universal description of the algorithm optimization is one of the key challenges in personalized recommendation. In this article, for the first time, we introduce a scaling-based algorithm (SCL independent of recommendation list length based on a hybrid algorithm of heat conduction and mass diffusion, by finding out the scaling function for the tunable parameter and object average degree. The optimal value of the tunable parameter can be abstracted from the scaling function, which is heterogeneous for the individual object. Experimental results obtained from three real datasets, Netflix, MovieLens and RYM, show that the SCL is highly accurate in recommendation. More importantly, compared with a number of excellent algorithms, including the mass diffusion method, the original hybrid method, and even an improved version of the hybrid method, the SCL algorithm remarkably promotes the personalized recommendation in three other aspects: solving the accuracy-diversity dilemma, presenting a high novelty, and solving the key challenge of cold start problem.

  16. Large-Scale Parallel Finite Element Analysis of the Stress Singular Problems

    International Nuclear Information System (INIS)

    Noriyuki Kushida; Hiroshi Okuda; Genki Yagawa

    2002-01-01

    In this paper, the convergence behavior of large-scale parallel finite element method for the stress singular problems was investigated. The convergence behavior of iterative solvers depends on the efficiency of the pre-conditioners. However, efficiency of pre-conditioners may be influenced by the domain decomposition that is necessary for parallel FEM. In this study the following results were obtained: Conjugate gradient method without preconditioning and the diagonal scaling preconditioned conjugate gradient method were not influenced by the domain decomposition as expected. symmetric successive over relaxation method preconditioned conjugate gradient method converged 6% faster as maximum if the stress singular area was contained in one sub-domain. (authors)

  17. FDTD method for laser absorption in metals for large scale problems.

    Science.gov (United States)

    Deng, Chun; Ki, Hyungson

    2013-10-21

    The FDTD method has been successfully used for many electromagnetic problems, but its application to laser material processing has been limited because even a several-millimeter domain requires a prohibitively large number of grids. In this article, we present a novel FDTD method for simulating large-scale laser beam absorption problems, especially for metals, by enlarging laser wavelength while maintaining the material's reflection characteristics. For validation purposes, the proposed method has been tested with in-house FDTD codes to simulate p-, s-, and circularly polarized 1.06 μm irradiation on Fe and Sn targets, and the simulation results are in good agreement with theoretical predictions.

  18. Structural problems of public participation in large-scale projects with environmental impact

    International Nuclear Information System (INIS)

    Bechmann, G.

    1989-01-01

    Four items are discussed showing that the problems involved through participation of the public in large-scale projects with environmental impact cannot be solved satisfactorily without suitable modification of the existing legal framework. The problematic items are: the status of the electric utilities as a quasi public enterprise; informal preliminary negotiations; the penetration of scientific argumentation into administrative decisions; the procedural concept. The paper discusses the fundamental issue of the problem-adequate design of the procedure and develops suggestions for a cooperative participation design. (orig./HSCH) [de

  19. Flexibility in Mathematics Problem Solving Based on Adversity Quotient

    Science.gov (United States)

    Dina, N. A.; Amin, S. M.; Masriyah

    2018-01-01

    Flexibility is an ability which is needed in problem solving. One of the ways in problem solving is influenced by Adversity Quotient (AQ). AQ is the power of facing difficulties. There are three categories of AQ namely climber, camper, and quitter. This research is a descriptive research using qualitative approach. The aim of this research is to describe flexibility in mathematics problem solving based on Adversity Quotient. The subjects of this research are climber student, camper student, and quitter student. This research was started by giving Adversity Response Profile (ARP) questioner continued by giving problem solving task and interviews. The validity of data measurement was using time triangulation. The results of this research shows that climber student uses two strategies in solving problem and doesn’t have difficulty. The camper student uses two strategies in solving problem but has difficulty to finish the second strategies. The quitter student uses one strategy in solving problem and has difficulty to finish it.

  20. The effect of problem-based and lecture-based instructional strategies on learner problem solving performance, problem solving processes, and attitudes

    Science.gov (United States)

    Visser, Yusra Laila

    This study compared the effect of lecture-based instruction to that of problem-based instruction on learner performance (on near-transfer and far-transfer problems), problem solving processes (reasoning strategy usage and reasoning efficiency), and attitudes (overall motivation and learner confidence) in a Genetics course. The study also analyzed the effect of self-regulatory skills and prior-academic achievement on performance for both instructional strategies. Sixty 11th grade students at a public math and science academy were assigned to either a lecture-based instructional strategy or a problem-based instructional strategy. Both treatment groups received 18 weeks of Genetics instruction through the assigned instructional strategy. In terms of problem solving performance, results revealed that the lecture-based group performed significantly better on near-transfer post-test problems. The problem-based group performed significantly better on far-transfer post-test problems. In addition, results indicated the learners in the lecture-based instructional treatment were significantly more likely to employ data-driven reasoning in the solving of problems, whereas learners in the problem-based instructional treatment were significantly more likely to employ hypothesis-driven reasoning in problem solving. No significant differences in reasoning efficiency were uncovered between treatment groups. Preliminary analysis of the motivation data suggested that there were no significant differences in motivation between treatment groups. However, a post-research exploratory analysis suggests that overall motivation was significantly higher in the lecture-based instructional treatment than in the problem-based instructional treatment. Learner confidence was significantly higher in the lecture-based group than in the problem-based group. A significant positive correlation was detected between self-regulatory skills scores and problem solving performance scores in the problem-based

  1. Inquiry-based problem solving in introductory physics

    Science.gov (United States)

    Koleci, Carolann

    What makes problem solving in physics difficult? How do students solve physics problems, and how does this compare to an expert physicist's strategy? Over the past twenty years, physics education research has revealed several differences between novice and expert problem solving. The work of Chi, Feltovich, and Glaser demonstrates that novices tend to categorize problems based on surface features, while experts categorize according to theory, principles, or concepts1. If there are differences between how problems are categorized, then are there differences between how physics problems are solved? Learning more about the problem solving process, including how students like to learn and what is most effective, requires both qualitative and quantitative analysis. In an effort to learn how novices and experts solve introductory electricity problems, a series of in-depth interviews were conducted, transcribed, and analyzed, using both qualitative and quantitative methods. One-way ANOVA tests were performed in order to learn if there are any significant problem solving differences between: (a) novices and experts, (b) genders, (c) students who like to answer questions in class and those who don't, (d) students who like to ask questions in class and those who don't, (e) students employing an interrogative approach to problem solving and those who don't, and (f) those who like physics and those who dislike it. The results of both the qualitative and quantitative methods reveal that inquiry-based problem solving is prevalent among novices and experts, and frequently leads to the correct physics. These findings serve as impetus for the third dimension of this work: the development of Choose Your Own Adventure Physics(c) (CYOAP), an innovative teaching tool in physics which encourages inquiry-based problem solving. 1Chi, M., P. Feltovich, R. Glaser, "Categorization and Representation of Physics Problems by Experts and Novices", Cognitive Science, 5, 121--152 (1981).

  2. Augmented neural networks and problem structure-based heuristics for the bin-packing problem

    Science.gov (United States)

    Kasap, Nihat; Agarwal, Anurag

    2012-08-01

    In this article, we report on a research project where we applied augmented-neural-networks (AugNNs) approach for solving the classical bin-packing problem (BPP). AugNN is a metaheuristic that combines a priority rule heuristic with the iterative search approach of neural networks to generate good solutions fast. This is the first time this approach has been applied to the BPP. We also propose a decomposition approach for solving harder BPP, in which subproblems are solved using a combination of AugNN approach and heuristics that exploit the problem structure. We discuss the characteristics of problems on which such problem structure-based heuristics could be applied. We empirically show the effectiveness of the AugNN and the decomposition approach on many benchmark problems in the literature. For the 1210 benchmark problems tested, 917 problems were solved to optimality and the average gap between the obtained solution and the upper bound for all the problems was reduced to under 0.66% and computation time averaged below 33 s per problem. We also discuss the computational complexity of our approach.

  3. SSB of Scale Symmetry, Fermion Families and Quintessence without the Long-Range Force Problem

    Science.gov (United States)

    Guendelman, E. I.; Kaganovich, A. B.

    We study a scale-invariant two measures theory where a dilaton field φ has no explicit potentials. The scale transformations include the translation of a dilaton φ-->φ+ const. The theory demonstrates a new mechanism for generation of the exponential potential: in the conformal Einstein frame (CEF), after SSB of scale invariance, the theory develops the exponential potential and, in general, the nonlinear kinetic term is generated as well. The scale symmetry does not allow the appearance of terms breaking the exponential shape of the potential that solves the problem of the flatness of the scalar field potential in the context of quintessential scenarios. As examples, two different possibilities for the choice of the dimensionless parameters are presented where the theory permits to get interesting cosmological results. For the first choice, the theory has standard scaling solutions for φ usually used in the context of the quintessential scenario. For the second choice, the theory allows three different solutions, one of which is a scaling solution with equation of state pφ=wρφ where w is predicted to be restricted by -1problem of particle physics. It is automatically achieved that for two of them, fermion masses are constants, the energy-momentum tensor is canonical and the ``fifth force'' is absent. For the third type of particles, a fermionic self-interaction appears as a result of SSB of scale invariance.

  4. Applying Groebner bases to solve reduction problems for Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, Alexander V.; Smirnov, Vladimir A.

    2006-01-01

    We describe how Groebner bases can be used to solve the reduction problem for Feynman integrals, i.e. to construct an algorithm that provides the possibility to express a Feynman integral of a given family as a linear combination of some master integrals. Our approach is based on a generalized Buchberger algorithm for constructing Groebner-type bases associated with polynomials of shift operators. We illustrate it through various examples of reduction problems for families of one- and two-loop Feynman integrals. We also solve the reduction problem for a family of integrals contributing to the three-loop static quark potential

  5. Applying Groebner bases to solve reduction problems for Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Alexander V. [Mechanical and Mathematical Department and Scientific Research Computer Center of Moscow State University, Moscow 119992 (Russian Federation); Smirnov, Vladimir A. [Nuclear Physics Institute of Moscow State University, Moscow 119992 (Russian Federation)

    2006-01-15

    We describe how Groebner bases can be used to solve the reduction problem for Feynman integrals, i.e. to construct an algorithm that provides the possibility to express a Feynman integral of a given family as a linear combination of some master integrals. Our approach is based on a generalized Buchberger algorithm for constructing Groebner-type bases associated with polynomials of shift operators. We illustrate it through various examples of reduction problems for families of one- and two-loop Feynman integrals. We also solve the reduction problem for a family of integrals contributing to the three-loop static quark potential.

  6. Integration, Provenance, and Temporal Queries for Large-Scale Knowledge Bases

    OpenAIRE

    Gao, Shi

    2016-01-01

    Knowledge bases that summarize web information in RDF triples deliver many benefits, including support for natural language question answering and powerful structured queries that extract encyclopedic knowledge via SPARQL. Large scale knowledge bases grow rapidly in terms of scale and significance, and undergo frequent changes in both schema and content. Two critical problems have thus emerged: (i) how to support temporal queries that explore the history of knowledge bases or flash-back to th...

  7. Effects of Problem Based Economics on High School Economics Instruction

    Science.gov (United States)

    Finkelstein, Neal; Hanson, Thomas

    2011-01-01

    The primary purpose of this study is to assess student-level impacts of a problem-based instructional approach to high school economics. The curriculum approach examined here was designed to increase class participation and content knowledge for high school students who are learning economics. This study tests the effectiveness of Problem Based…

  8. Implementation of Problem Based Learning among Nursing Students

    Science.gov (United States)

    Hamdan, Abdul Rahim; Kwan, Chan Li; Khan, Aqeel; Ghafar, Mohamed Najib Abdul; Sihes, Ahmad Johari

    2014-01-01

    Critical thinking and effective problem solving skills have been regarded as an important element and as an educational outcome in professional nursing. The purpose of this study is to examine the implementation of Problem Based Learning (PBL) among nursing students. More specifically, it compares pretest and post test scores of the implementation…

  9. The afforestation problem: a heuristic method based on simulated annealing

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1992-01-01

    This paper presents the afforestation problem, that is the location and design of new forest compartments to be planted in a given area. This optimization problem is solved by a two-step heuristic method based on simulated annealing. Tests and experiences with this method are also presented....

  10. Problem-Based Group Activities for Teaching Sensation and Perception

    Science.gov (United States)

    Kreiner, David S.

    2009-01-01

    This article describes 14 problem-based group activities for a sensation and perception course. The intent was to provide opportunities for students to practice applying their knowledge to real-world problems related to course content. Student ratings of how effectively the activities helped them learn were variable but relatively high. Students…

  11. Problem-Based Learning in Formal and Informal Learning Environments

    Science.gov (United States)

    Shimic, Goran; Jevremovic, Aleksandar

    2012-01-01

    Problem-based learning (PBL) is a student-centered instructional strategy in which students solve problems and reflect on their experiences. Different domains need different approaches in the design of PBL systems. Therefore, we present one case study in this article: A Java Programming PBL. The application is developed as an additional module for…

  12. Does Solving Insight-Based Problems Differ from Solving Learning-Based Problems? Some Evidence from an ERP Study

    Science.gov (United States)

    Leikin, Roza; Waisman, Ilana; Leikin, Mark

    2016-01-01

    We asked: "What are the similarities and differences in mathematical processing associated with solving learning-based and insight-based problems?" To answer this question, the ERP research procedure was employed with 69 male adolescent subjects who solved specially designed insight-based and learning-based tests. Solutions of…

  13. Validation of the Turkish version of the problem areas in diabetes scale

    DEFF Research Database (Denmark)

    Huis In 't Veld, Elisabeth M J; Makine, Ceylan; Nouwen, Arie

    2011-01-01

    was conducted among 154 patients with insulin-naïve type 2 diabetes. Participants completed the PAID, Centre for Epidemiological Studies Depression Scale (CES-D), Insulin Treatment Appraisal Scale (ITAS), and World Health Organization-Five Well-Being Index (WHO-5) questionnaires. Exploratory factor analyses...... yielded a 2-factor structure, identifying a 15-item "diabetes distress" factor and a 5-item "support-related issues" factor. The total PAID-score and the two dimensions were associated with higher levels of depression and poor emotional well-being. In the present study, the Turkish version of the PAID had......The Problem Areas in Diabetes (PAID) scale is a widely used self-report measure that can facilitate detection of diabetes-specific emotional distress in clinical practice. The aim of this study was to assess the factor structure and validity of the Turkish version of the PAID. A validation study...

  14. [Spanish adaptation of the "Mobile Phone Problem Use Scale" for adolescent population].

    Science.gov (United States)

    López-Fernández, Olatz; Honrubia-Serrano, Ma Luisa; Freixa-Blanxart, Montserrat

    2012-01-01

    Problematic use of the mobile telephone is an emerging phenomenon in our society, and one which particularly affects the teenage population. Knowledge from research on the problematic use of this technology is necessary, since such use can give rise to a behavioural pattern with addictive characteristics. There are hardly any scales for measuring possible problematic use of mobile phones, and none at all adapted exclusively for the Spanish adolescent population. The scale most widely used internationally is the Mobile Phone Problem Use Scale (MPPUS). The aim of the present study is to adapt the MPPUS for use with Spanish adolescents. The Spanish version of the questionnaire was administered to a sample of 1132 adolescents aged 12 to 18. Reliability and factorial validity were comparable to those obtained in adult population, so that the measure of problematic mobile phone use in Spanish teenagers is one-dimensional. A prevalence of 14.8% of problematic users was detected.

  15. Creating Problem-Based Leadership Learning across the Curriculum

    Science.gov (United States)

    Thompson, Sara E.; Couto, Richard A.

    2016-01-01

    This chapter explores problem-based learning (PBL) as effective pedagogy to enhance leadership learning. Through institutional examples, research, and personal experiences, the authors provide a rationale for faculty and staff to utilize PBL across the curriculum.

  16. Numerical methods for the design of large-scale nonlinear discrete ill-posed inverse problems

    International Nuclear Information System (INIS)

    Haber, E; Horesh, L; Tenorio, L

    2010-01-01

    Design of experiments for discrete ill-posed problems is a relatively new area of research. While there has been some limited work concerning the linear case, little has been done to study design criteria and numerical methods for ill-posed nonlinear problems. We present an algorithmic framework for nonlinear experimental design with an efficient numerical implementation. The data are modeled as indirect, noisy observations of the model collected via a set of plausible experiments. An inversion estimate based on these data is obtained by a weighted Tikhonov regularization whose weights control the contribution of the different experiments to the data misfit term. These weights are selected by minimization of an empirical estimate of the Bayes risk that is penalized to promote sparsity. This formulation entails a bilevel optimization problem that is solved using a simple descent method. We demonstrate the viability of our design with a problem in electromagnetic imaging based on direct current resistivity and magnetotelluric data

  17. ENGAGE: A Game Based Learning and Problem Solving Framework

    Science.gov (United States)

    2012-07-13

    Gamification Summit 2012  Mensa Colloquium 2012.2: Social and Video Games  Seattle Science Festival  TED Salon Vancouver : http...From - To) 6/1/2012 – 6/30/2012 4. TITLE AND SUBTITLE ENGAGE: A Game Based Learning and Problem Solving Framework 5a. CONTRACT NUMBER N/A 5b...Popović ENGAGE: A Game Based Learning and Problem Solving Framework (Task 1 Month 4) Progress, Status and Management Report Monthly Progress

  18. Seesaw induced electroweak scale, the hierarchy problem and sub-eV neutrino masses

    International Nuclear Information System (INIS)

    Atwood, D.; Bar-Shalom, S.; Soni, A.

    2006-01-01

    We describe a model for the scalar sector where all interactions occur either at an ultra-high scale, Λ U ∝10 16 -10 19 GeV, or at an intermediate scale, Λ I =10 9 -10 11 GeV. The interaction of physics on these two scales results in an SU(2) Higgs condensate at the electroweak (EW) scale, Λ EW , through a seesaw-like Higgs mechanism, Λ EW ∝Λ I 2 /Λ U , while the breaking of the SM SU(2) x U(1) gauge symmetry occurs at the intermediate scale Λ I . The EW scale is, therefore, not fundamental but is naturally generated in terms of ultra-high energy phenomena and so the hierarchy problem is alleviated. We show that the class of such ''seesaw Higgs'' models predict the existence of sub-eV neutrino masses which are generated through a ''two-step'' seesaw mechanism in terms of the same two ultra-high scales: m ν ∝Λ I 4 /Λ U 3 ∝Λ EW 2 /Λ U . The neutrinos can be either Dirac or Majorana, depending on the structure of the scalar potential. We also show that our seesaw Higgs model can be naturally embedded in theories with tiny extra dimensions of size R∝Λ U -1 ∝10 -16 fm, where the seesaw induced EW scale arises from a violation of a symmetry at a distant brane; in particular, in the scenario presented there are seven tiny extra dimensions. (orig.)

  19. Process competencies in a problem and project based learning environment

    DEFF Research Database (Denmark)

    Du, Xiangyun; Kolmos, Anette

    2006-01-01

    with the expected professional competencies. Based on the educational practice of PBL Aalborg Model, which is characterized by problem-orientation, project-organization and team work, this paper examines the process of developing process competencies through studying engineering in a PBL environment from...... process competencies through doing problem and project based work in teams? 2) How do students perceive their achievement of these process competencies?......Future engineers are not only required to master technological competencies concerning solving problems, producing and innovating technology, they are also expected to have capabilities of cooperation, communication, and project management in diverse social context, which are referred to as process...

  20. Solving the three-body Coulomb breakup problem using exterior complex scaling

    Energy Technology Data Exchange (ETDEWEB)

    McCurdy, C.W.; Baertschy, M.; Rescigno, T.N.

    2004-05-17

    Electron-impact ionization of the hydrogen atom is the prototypical three-body Coulomb breakup problem in quantum mechanics. The combination of subtle correlation effects and the difficult boundary conditions required to describe two electrons in the continuum have made this one of the outstanding challenges of atomic physics. A complete solution of this problem in the form of a ''reduction to computation'' of all aspects of the physics is given by the application of exterior complex scaling, a modern variant of the mathematical tool of analytic continuation of the electronic coordinates into the complex plane that was used historically to establish the formal analytic properties of the scattering matrix. This review first discusses the essential difficulties of the three-body Coulomb breakup problem in quantum mechanics. It then describes the formal basis of exterior complex scaling of electronic coordinates as well as the details of its numerical implementation using a variety of methods including finite difference, finite elements, discrete variable representations, and B-splines. Given these numerical implementations of exterior complex scaling, the scattering wave function can be generated with arbitrary accuracy on any finite volume in the space of electronic coordinates, but there remains the fundamental problem of extracting the breakup amplitudes from it. Methods are described for evaluating these amplitudes. The question of the volume-dependent overall phase that appears in the formal theory of ionization is resolved. A summary is presented of accurate results that have been obtained for the case of electron-impact ionization of hydrogen as well as a discussion of applications to the double photoionization of helium.

  1. Problem-based learning on quantitative analytical chemistry course

    Science.gov (United States)

    Fitri, Noor

    2017-12-01

    This research applies problem-based learning method on chemical quantitative analytical chemistry, so called as "Analytical Chemistry II" course, especially related to essential oil analysis. The learning outcomes of this course include aspects of understanding of lectures, the skills of applying course materials, and the ability to identify, formulate and solve chemical analysis problems. The role of study groups is quite important in improving students' learning ability and in completing independent tasks and group tasks. Thus, students are not only aware of the basic concepts of Analytical Chemistry II, but also able to understand and apply analytical concepts that have been studied to solve given analytical chemistry problems, and have the attitude and ability to work together to solve the problems. Based on the learning outcome, it can be concluded that the problem-based learning method in Analytical Chemistry II course has been proven to improve students' knowledge, skill, ability and attitude. Students are not only skilled at solving problems in analytical chemistry especially in essential oil analysis in accordance with local genius of Chemistry Department, Universitas Islam Indonesia, but also have skilled work with computer program and able to understand material and problem in English.

  2. Application of wavelet scaling function expansion continuous-energy resonance calculation method to MOX fuel problem

    International Nuclear Information System (INIS)

    Yang, W.; Wu, H.; Cao, L.

    2012-01-01

    More and more MOX fuels are used in all over the world in the past several decades. Compared with UO 2 fuel, it contains some new features. For example, the neutron spectrum is harder and more resonance interference effects within the resonance energy range are introduced because of more resonant nuclides contained in the MOX fuel. In this paper, the wavelets scaling function expansion method is applied to study the resonance behavior of plutonium isotopes within MOX fuel. Wavelets scaling function expansion continuous-energy self-shielding method is developed recently. It has been validated and verified by comparison to Monte Carlo calculations. In this method, the continuous-energy cross-sections are utilized within resonance energy, which means that it's capable to solve problems with serious resonance interference effects without iteration calculations. Therefore, this method adapts to treat the MOX fuel resonance calculation problem natively. Furthermore, plutonium isotopes have fierce oscillations of total cross-section within thermal energy range, especially for 240 Pu and 242 Pu. To take thermal resonance effect of plutonium isotopes into consideration the wavelet scaling function expansion continuous-energy resonance calculation code WAVERESON is enhanced by applying the free gas scattering kernel to obtain the continuous-energy scattering source within thermal energy range (2.1 eV to 4.0 eV) contrasting against the resonance energy range in which the elastic scattering kernel is utilized. Finally, all of the calculation results of WAVERESON are compared with MCNP calculation. (authors)

  3. Parallel supercomputing: Advanced methods, algorithms, and software for large-scale linear and nonlinear problems

    Energy Technology Data Exchange (ETDEWEB)

    Carey, G.F.; Young, D.M.

    1993-12-31

    The program outlined here is directed to research on methods, algorithms, and software for distributed parallel supercomputers. Of particular interest are finite element methods and finite difference methods together with sparse iterative solution schemes for scientific and engineering computations of very large-scale systems. Both linear and nonlinear problems will be investigated. In the nonlinear case, applications with bifurcation to multiple solutions will be considered using continuation strategies. The parallelizable numerical methods of particular interest are a family of partitioning schemes embracing domain decomposition, element-by-element strategies, and multi-level techniques. The methods will be further developed incorporating parallel iterative solution algorithms with associated preconditioners in parallel computer software. The schemes will be implemented on distributed memory parallel architectures such as the CRAY MPP, Intel Paragon, the NCUBE3, and the Connection Machine. We will also consider other new architectures such as the Kendall-Square (KSQ) and proposed machines such as the TERA. The applications will focus on large-scale three-dimensional nonlinear flow and reservoir problems with strong convective transport contributions. These are legitimate grand challenge class computational fluid dynamics (CFD) problems of significant practical interest to DOE. The methods developed and algorithms will, however, be of wider interest.

  4. Self-interacting inelastic dark matter: a viable solution to the small scale structure problems

    Energy Technology Data Exchange (ETDEWEB)

    Blennow, Mattias; Clementz, Stefan; Herrero-Garcia, Juan, E-mail: emb@kth.se, E-mail: scl@kth.se, E-mail: juan.herrero-garcia@adelaide.edu.au [Department of Physics, School of Engineering Sciences, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm (Sweden)

    2017-03-01

    Self-interacting dark matter has been proposed as a solution to the small-scale structure problems, such as the observed flat cores in dwarf and low surface brightness galaxies. If scattering takes place through light mediators, the scattering cross section relevant to solve these problems may fall into the non-perturbative regime leading to a non-trivial velocity dependence, which allows compatibility with limits stemming from cluster-size objects. However, these models are strongly constrained by different observations, in particular from the requirements that the decay of the light mediator is sufficiently rapid (before Big Bang Nucleosynthesis) and from direct detection. A natural solution to reconcile both requirements are inelastic endothermic interactions, such that scatterings in direct detection experiments are suppressed or even kinematically forbidden if the mass splitting between the two-states is sufficiently large. Using an exact solution when numerically solving the Schrödinger equation, we study such scenarios and find regions in the parameter space of dark matter and mediator masses, and the mass splitting of the states, where the small scale structure problems can be solved, the dark matter has the correct relic abundance and direct detection limits can be evaded.

  5. A Computer-Based Visual Analog Scale,

    Science.gov (United States)

    1992-06-01

    34 keys on the computer keyboard or other input device. The initial position of the arrow is always in the center of the scale to prevent biasing the...3 REFERENCES 1. Gift, A.G., "Visual Analogue Scales: Measurement of Subjective Phenomena." Nursing Research, Vol. 38, pp. 286-288, 1989. 2. Ltmdberg...3. Menkes, D.B., Howard, R.C., Spears, G.F., and Cairns, E.R., "Salivary THC Following Cannabis Smoking Correlates With Subjective Intoxication and

  6. Problem-based learning biotechnology courses in chemical engineering.

    Science.gov (United States)

    Glatz, Charles E; Gonzalez, Ramon; Huba, Mary E; Mallapragada, Surya K; Narasimhan, Balaji; Reilly, Peter J; Saunders, Kevin P; Shanks, Jacqueline V

    2006-01-01

    We have developed a series of upper undergraduate/graduate lecture and laboratory courses on biotechnological topics to supplement existing biochemical engineering, bioseparations, and biomedical engineering lecture courses. The laboratory courses are based on problem-based learning techniques, featuring two- and three-person teams, journaling, and performance rubrics for guidance and assessment. Participants initially have found them to be difficult, since they had little experience with problem-based learning. To increase enrollment, we are combining the laboratory courses into 2-credit groupings and allowing students to substitute one of them for the second of our 2-credit chemical engineering unit operations laboratory courses.

  7. Student and tutor perception of a new problem based learning ...

    African Journals Online (AJOL)

    Background: The Makerere University Faculty of Medicine started the implementation of the Problem Based Learning/Community Based Education and Service curriculum for incoming students in the academic year 2003/2004. It undertook an intense preparatory period of 2 years before implementation, which included ...

  8. New Realities and the Implications for Problem Based Learning

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull

    2004-01-01

    -based learning model with the new realities of today. Three new realities are discussed, the new global realities, the new business realities, and the new realities at the individual level. The new realities challenge the problem-based learning model. Adjustments are needed in terms of closer co...

  9. Scaffolding Problem-Based Learning with CSCL Tools

    Science.gov (United States)

    Lu, Jingyan; Lajoie, Susanne P.; Wiseman, Jeffrey

    2010-01-01

    Small-group medical problem-based learning (PBL) was a pioneering form of collaborative learning at the university level. It has traditionally been delivered in face-to-face text-based format. With the advancement of computer technology and progress in CSCL, educational researchers are now exploring how to design digitally-implemented scaffolding…

  10. Solution to the hierarchy problem from an almost decoupled hidden sector within a classically scale invariant theory

    International Nuclear Information System (INIS)

    Foot, Robert; Kobakhidze, Archil; Volkas, Raymond R.; McDonald, Kristian L.

    2008-01-01

    If scale invariance is a classical symmetry then both the Planck scale and the weak scale should emerge as quantum effects. We show that this can be realized in simple scale invariant theories with a hidden sector. The weak/Planck scale hierarchy emerges in the (technically natural) limit in which the hidden sector decouples from the ordinary sector. In this limit, finite corrections to the weak scale are consequently small, while quadratic divergences are absent by virtue of classical scale invariance, so there is no hierarchy problem

  11. Constraint-Based Local Search for Constrained Optimum Paths Problems

    Science.gov (United States)

    Pham, Quang Dung; Deville, Yves; van Hentenryck, Pascal

    Constrained Optimum Path (COP) problems arise in many real-life applications and are ubiquitous in communication networks. They have been traditionally approached by dedicated algorithms, which are often hard to extend with side constraints and to apply widely. This paper proposes a constraint-based local search (CBLS) framework for COP applications, bringing the compositionality, reuse, and extensibility at the core of CBLS and CP systems. The modeling contribution is the ability to express compositional models for various COP applications at a high level of abstraction, while cleanly separating the model and the search procedure. The main technical contribution is a connected neighborhood based on rooted spanning trees to find high-quality solutions to COP problems. The framework, implemented in COMET, is applied to Resource Constrained Shortest Path (RCSP) problems (with and without side constraints) and to the edge-disjoint paths problem (EDP). Computational results show the potential significance of the approach.

  12. Cultural-based particle swarm for dynamic optimisation problems

    Science.gov (United States)

    Daneshyari, Moayed; Yen, Gary G.

    2012-07-01

    Many practical optimisation problems are with the existence of uncertainties, among which a significant number belong to the dynamic optimisation problem (DOP) category in which the fitness function changes through time. In this study, we propose the cultural-based particle swarm optimisation (PSO) to solve DOP problems. A cultural framework is adopted incorporating the required information from the PSO into five sections of the belief space, namely situational, temporal, domain, normative and spatial knowledge. The stored information will be adopted to detect the changes in the environment and assists response to the change through a diversity-based repulsion among particles and migration among swarms in the population space, and also helps in selecting the leading particles in three different levels, personal, swarm and global levels. Comparison of the proposed heuristics over several difficult dynamic benchmark problems demonstrates the better or equal performance with respect to most of other selected state-of-the-art dynamic PSO heuristics.

  13. Mercury exposure of workers and health problems related with small-scale gold panning and extraction

    International Nuclear Information System (INIS)

    Khan, S.; Shah, M.T.; Din, I.U.; Rehman, S.

    2012-01-01

    This study was conducted to investigate mercury (Hg) exposure and health problems related to small-scale gold panning and extraction (GPE) in the northern Pakistan. Urine and blood samples of occupational and non-occupational persons were analyzed for total Hg, while blood's fractions including red blood cells and plasma were analyzed for total Hg and its inorganic and organic species. The concentrations of Hg in urine and blood samples were significantly (P<0.01) higher in occupational persons as compared to non-occupational and exceeded the permissible limits set by World Health Organization (WHO) and United State Environmental Protection Agency (US-EPA). Furthermore, the data indicated that numerous health problems were present in occupational persons involved in GPE. (author)

  14. Mapping the MMPI-2-RF Specific Problems Scales Onto Extant Psychopathology Structures.

    Science.gov (United States)

    Sellbom, Martin

    2017-01-01

    A main objective in developing the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 ) was to link the hierarchical structure of the instrument's scales to contemporary psychopathology and personality models for greater enhancement of construct validity. Initial evidence published with the Restructured Clinical scales has indicated promising results in that the higher order structure of these measures maps onto those reported in the extant psychopathology literature. This study focused on evaluating the internal structure of the Specific Problems and Interest scales, which have not yet been examined in this manner. Two large, mixed-gender outpatient and correctional samples were used. Exploratory factor analyses revealed consistent evidence for a 4-factor structure representing somatization, negative affect, externalizing, and social detachment. Convergent and discriminant validity analyses in the outpatient sample yielded a pattern of results consistent with expectations. These findings add further evidence to indicate that the MMPI-2-RF hierarchy of scales map onto extant psychopathology literature, and also add support to the notion that somatization and detachment should be considered important higher order domains in the psychopathology literature.

  15. Correlation-based decimation in constraint satisfaction problems

    International Nuclear Information System (INIS)

    Higuchi, Saburo; Mezard, Marc

    2010-01-01

    We study hard constraint satisfaction problems using some decimation algorithms based on mean-field approximations. The message-passing approach is used to estimate, beside the usual one-variable marginals, the pair correlation functions. The identification of strongly correlated pairs allows to use a new decimation procedure, where the relative orientation of a pair of variables is fixed. We apply this novel decimation to locked occupation problems, a class of hard constraint satisfaction problems where the usual belief-propagation guided decimation performs poorly. The pair-decimation approach provides a significant improvement.

  16. A typology of time-scale mismatches and behavioral interventions to diagnose and solve conservation problems

    Science.gov (United States)

    Wilson, Robyn S.; Hardisty, David J.; Epanchin-Niell, Rebecca S.; Runge, Michael C.; Cottingham, Kathryn L.; Urban, Dean L.; Maguire, Lynn A.; Hastings, Alan; Mumby, Peter J.; Peters, Debra P.C.

    2016-01-01

    Ecological systems often operate on time scales significantly longer or shorter than the time scales typical of human decision making, which causes substantial difficulty for conservation and management in socioecological systems. For example, invasive species may move faster than humans can diagnose problems and initiate solutions, and climate systems may exhibit long-term inertia and short-term fluctuations that obscure learning about the efficacy of management efforts in many ecological systems. We adopted a management-decision framework that distinguishes decision makers within public institutions from individual actors within the social system, calls attention to the ways socioecological systems respond to decision makers’ actions, and notes institutional learning that accrues from observing these responses. We used this framework, along with insights from bedeviling conservation problems, to create a typology that identifies problematic time-scale mismatches occurring between individual decision makers in public institutions and between individual actors in the social or ecological system. We also considered solutions that involve modifying human perception and behavior at the individual level as a means of resolving these problematic mismatches. The potential solutions are derived from the behavioral economics and psychology literature on temporal challenges in decision making, such as the human tendency to discount future outcomes at irrationally high rates. These solutions range from framing environmental decisions to enhance the salience of long-term consequences, to using structured decision processes that make time scales of actions and consequences more explicit, to structural solutions aimed at altering the consequences of short-sighted behavior to make it less appealing. Additional application of these tools and long-term evaluation measures that assess not just behavioral changes but also associated changes in ecological systems are needed.

  17. A typology of time-scale mismatches and behavioral interventions to diagnose and solve conservation problems.

    Science.gov (United States)

    Wilson, Robyn S; Hardisty, David J; Epanchin-Niell, Rebecca S; Runge, Michael C; Cottingham, Kathryn L; Urban, Dean L; Maguire, Lynn A; Hastings, Alan; Mumby, Peter J; Peters, Debra P C

    2016-02-01

    Ecological systems often operate on time scales significantly longer or shorter than the time scales typical of human decision making, which causes substantial difficulty for conservation and management in socioecological systems. For example, invasive species may move faster than humans can diagnose problems and initiate solutions, and climate systems may exhibit long-term inertia and short-term fluctuations that obscure learning about the efficacy of management efforts in many ecological systems. We adopted a management-decision framework that distinguishes decision makers within public institutions from individual actors within the social system, calls attention to the ways socioecological systems respond to decision makers' actions, and notes institutional learning that accrues from observing these responses. We used this framework, along with insights from bedeviling conservation problems, to create a typology that identifies problematic time-scale mismatches occurring between individual decision makers in public institutions and between individual actors in the social or ecological system. We also considered solutions that involve modifying human perception and behavior at the individual level as a means of resolving these problematic mismatches. The potential solutions are derived from the behavioral economics and psychology literature on temporal challenges in decision making, such as the human tendency to discount future outcomes at irrationally high rates. These solutions range from framing environmental decisions to enhance the salience of long-term consequences, to using structured decision processes that make time scales of actions and consequences more explicit, to structural solutions aimed at altering the consequences of short-sighted behavior to make it less appealing. Additional application of these tools and long-term evaluation measures that assess not just behavioral changes but also associated changes in ecological systems are needed. © 2015

  18. How efficient is sliding-scale insulin therapy? Problems with a 'cookbook' approach in hospitalized patients.

    Science.gov (United States)

    Katz, C M

    1991-04-01

    Sliding-scale insulin therapy is seldom the best way to treat hospitalized diabetic patients. In the few clinical situations in which it is appropriate, close attention to details and solidly based scientific principles is absolutely necessary. Well-organized alternative approaches to insulin therapy usually offer greater efficiency and effectiveness.

  19. Measurement, modeling and perception of painted surfaces: A Multi-scale Analysis of the Touch-up Problem

    Science.gov (United States)

    Kalghatgi, Suparna Kishore

    Real-world surfaces typically have geometric features at a range of spatial scales. At the microscale, opaque surfaces are often characterized by bidirectional reflectance distribution functions (BRDF), which describes how a surface scatters incident light. At the mesoscale, surfaces often exhibit visible texture -- stochastic or patterned arrangements of geometric features that provide visual information about surface properties such as roughness, smoothness, softness, etc. These textures also affect how light is scattered by the surface, but the effects are at a different spatial scale than those captured by the BRDF. Through this research, we investigate how microscale and mesoscale surface properties interact to contribute to overall surface appearance. This behavior is also the cause of the well-known "touch-up problem" in the paint industry, where two regions coated with exactly the same paint, look different in color, gloss and/or texture because of differences in application methods. At first, samples were created by applying latex paint to standard wallboard surfaces. Two application methods- spraying and rolling were used. The BRDF and texture properties of the samples were measured, which revealed differences at both the microscale and mesoscale. This data was then used as input for a physically-based image synthesis algorithm, to generate realistic images of the surfaces under different viewing conditions. In order to understand the factors that govern touch-up visibility, psychophysical tests were conducted using calibrated, digital photographs of the samples as stimuli. Images were presented in pairs and a two alternative forced choice design was used for the experiments. These judgments were then used as data for a Thurstonian scaling analysis to produce psychophysical scales of visibility, which helped determine the effect of paint formulation, application methods, and viewing and illumination conditions on the touch-up problem. The results can be

  20. Scaling architecture-on-demand based optical networks

    NARCIS (Netherlands)

    Meyer, Hugo; Sancho, Jose Carlos; Mrdakovic, Milica; Peng, Shuping; Simeonidou, Dimitra; Miao, Wang; Calabretta, Nicola

    2016-01-01

    This paper analyzes methodologies that allow scaling properly Architecture-On-Demand (AoD) based optical networks. As Data Centers and HPC systems are growing in size and complexity, optical networks seem to be the way to scale the bandwidth of current network infrastructures. To scale the number of

  1. A Large-Scale Study of Fingerprint Matching Systems for Sensor Interoperability Problem

    Directory of Open Access Journals (Sweden)

    Helala AlShehri

    2018-03-01

    Full Text Available The fingerprint is a commonly used biometric modality that is widely employed for authentication by law enforcement agencies and commercial applications. The designs of existing fingerprint matching methods are based on the hypothesis that the same sensor is used to capture fingerprints during enrollment and verification. Advances in fingerprint sensor technology have raised the question about the usability of current methods when different sensors are employed for enrollment and verification; this is a fingerprint sensor interoperability problem. To provide insight into this problem and assess the status of state-of-the-art matching methods to tackle this problem, we first analyze the characteristics of fingerprints captured with different sensors, which makes cross-sensor matching a challenging problem. We demonstrate the importance of fingerprint enhancement methods for cross-sensor matching. Finally, we conduct a comparative study of state-of-the-art fingerprint recognition methods and provide insight into their abilities to address this problem. We performed experiments using a public database (FingerPass that contains nine datasets captured with different sensors. We analyzed the effects of different sensors and found that cross-sensor matching performance deteriorates when different sensors are used for enrollment and verification. In view of our analysis, we propose future research directions for this problem.

  2. A Large-Scale Study of Fingerprint Matching Systems for Sensor Interoperability Problem.

    Science.gov (United States)

    AlShehri, Helala; Hussain, Muhammad; AboAlSamh, Hatim; AlZuair, Mansour

    2018-03-28

    The fingerprint is a commonly used biometric modality that is widely employed for authentication by law enforcement agencies and commercial applications. The designs of existing fingerprint matching methods are based on the hypothesis that the same sensor is used to capture fingerprints during enrollment and verification. Advances in fingerprint sensor technology have raised the question about the usability of current methods when different sensors are employed for enrollment and verification; this is a fingerprint sensor interoperability problem. To provide insight into this problem and assess the status of state-of-the-art matching methods to tackle this problem, we first analyze the characteristics of fingerprints captured with different sensors, which makes cross-sensor matching a challenging problem. We demonstrate the importance of fingerprint enhancement methods for cross-sensor matching. Finally, we conduct a comparative study of state-of-the-art fingerprint recognition methods and provide insight into their abilities to address this problem. We performed experiments using a public database (FingerPass) that contains nine datasets captured with different sensors. We analyzed the effects of different sensors and found that cross-sensor matching performance deteriorates when different sensors are used for enrollment and verification. In view of our analysis, we propose future research directions for this problem.

  3. UICEE Centre for Problem Based Learning (UCPBL) at Aalborg University

    DEFF Research Database (Denmark)

    Fink, Flemming Kobberøe; Enemark, Stig; Moesby, Egon

    2002-01-01

    University is considered to have a strong position in Problem-Based Learning (PBL) with many years of experience. Within engineering education co-operation with industry has also always been a field of high importance for Aalborg University and part of the PBL concept. An increasing number of universities...... and engineering schools worldwide are consequently seeking consultancy and cooperation with Aalborg University. The establishment of UCPBL is therefore welcomed as a possibility to merge these activities into one organisational structure and to strengthen the effort of improving engineering education......UICEE Centre for Problem-Based Learning (UCPBL) is a global centre for Problem-Based Learning located at Aalborg University, Denmark UCPBL is established as a partner to the UNESCO International Centre for Engineering Education (UICEE) located at Monash University, Melbourne, Australia. Aalborg...

  4. PENERAPAN BLENDED-PROBLEM BASED LEARNING DALAM PEMBELAJARAN BIOLOGI

    Directory of Open Access Journals (Sweden)

    Samuel Agus Triyanto

    2016-07-01

    Biologi abad 21 merupakan integrasi dan mengintegrasikan kembali sub disiplin ilmu biologi, serta integrasi biologi dengan disiplin ilmu lain untuk mengatasi permasalahan sosial. Penelitian ini bertujuan untuk mengetahui penerapan Blended-Problem Based Learning, aktivitas belajar, dan respon siswa dalam pembelajaran biologi. Penelitian ini merupakan penelitian survei dengan pendekatan deskriptif kualitatif. Data hasil penelitian menunjukkan bahwa aktivitas positif siswa dalam pembelajaran memuaskan, sedangkan respon siswa baik terhadap pembelajaran. Berdasarkan hasil penelitian, disimpulkan bahwa Blended-Problem Based Learning dapat diterapkan dan diterima sebagai model dalam pembelajaran.

  5. Problem-based and project-oriented learning

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Chen, Zhe

    2005-01-01

    . Generally, the content of the curriculum should be more expanded without extra study time. This paper presents a teaching approach, which makes it possible very fast for the students to obtain in-depth skills into new research areas, and this method is the problem-oriented and project-based learning....... In this paper the necessary skills for power electronic engineers are outlined that is followed up by a description on how the problem-oriented and project-based learning are implemented. A complete curriculum in power electronics and drives at Aalborg University is presented where different power electronics...... related projects at different study levels also are presented....

  6. An Analysis of the HEU-MET-FAST-035 Problem Using CENTRM and SCALE

    International Nuclear Information System (INIS)

    Hollenbach, D.F.; Jordan, W.C.

    1999-01-01

    An U/Fe benchmark, designated as HEU-MET-FAST-035, has been approved for inclusion in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. The SCALE code and cross sections performed poorly in calculating this critical experiment. Deficiencies in both the ENDF/B-V representation of the resonance region for Fe and in the Nordheim integral treatment when applied to Fe were identified. The combination of these deficiencies led to an almost 10% over-prediction of k(eff). Problems involving a large percentage of Fe and intermediate-energy spectrums present special cross-section processing difficulties for SCALE. In ENDF/B-V, resonance data for Fe only go to 400 keV, although resonances are present well above 1 MeV. Significant resonance data are stored as file 3 data instead of as resonance parameters. The Nordheim Integral Treatment used in NITAWL to process cross sections assume: resonances are widely spaced and all relevant information is contained in the resonance parameters (file 3 data is not processed). These limitations and assumptions result in poor solutions for this class of problems

  7. Relationship between family history of alcohol addiction, parents' education level, and smartphone problem use scale scores.

    Science.gov (United States)

    Beison, Ashley; Rademacher, David J

    2017-03-01

    Background and aims Smartphones are ubiquitous. As smartphones increased in popularity, researchers realized that people were becoming dependent on their smartphones. The purpose here was to provide a better understanding of the factors related to problematic smartphone use (PSPU). Methods The participants were 100 undergraduates (25 males, 75 females) whose ages ranged from 18 to 23 (mean age = 20 years). The participants completed questionnaires to assess gender, ethnicity, year in college, father's education level, mother's education level, family income, age, family history of alcoholism, and PSPU. The Family Tree Questionnaire assessed family history of alcoholism. The Mobile Phone Problem Use Scale (MPPUS) and the Adapted Cell Phone Addiction Test (ACPAT) were used to determine the degree of PSPU. Whereas the MPPUS measures tolerance, escape from other problems, withdrawal, craving, and negative life consequences, the ACPAT measures preoccupation (salience), excessive use, neglecting work, anticipation, lack of control, and neglecting social life. Results Family history of alcoholism and father's education level together explained 26% of the variance in the MPPUS scores and 25% of the variance in the ACPAT scores. The inclusion of mother's education level, ethnicity, family income, age, year in college, and gender did not significantly increase the proportion of variance explained for either MPPUS or ACPAT scores. Discussion and conclusions Family history of alcoholism and father's education level are good predictors of PSPU. As 74%-75% of the variance in PSPU scale scores was not explained, future studies should aim to explain this variance.

  8. EvArnoldi: A New Algorithm for Large-Scale Eigenvalue Problems.

    Science.gov (United States)

    Tal-Ezer, Hillel

    2016-05-19

    Eigenvalues and eigenvectors are an essential theme in numerical linear algebra. Their study is mainly motivated by their high importance in a wide range of applications. Knowledge of eigenvalues is essential in quantum molecular science. Solutions of the Schrödinger equation for the electrons composing the molecule are the basis of electronic structure theory. Electronic eigenvalues compose the potential energy surfaces for nuclear motion. The eigenvectors allow calculation of diople transition matrix elements, the core of spectroscopy. The vibrational dynamics molecule also requires knowledge of the eigenvalues of the vibrational Hamiltonian. Typically in these problems, the dimension of Hilbert space is huge. Practically, only a small subset of eigenvalues is required. In this paper, we present a highly efficient algorithm, named EvArnoldi, for solving the large-scale eigenvalues problem. The algorithm, in its basic formulation, is mathematically equivalent to ARPACK ( Sorensen , D. C. Implicitly Restarted Arnoldi/Lanczos Methods for Large Scale Eigenvalue Calculations ; Springer , 1997 ; Lehoucq , R. B. ; Sorensen , D. C. SIAM Journal on Matrix Analysis and Applications 1996 , 17 , 789 ; Calvetti , D. ; Reichel , L. ; Sorensen , D. C. Electronic Transactions on Numerical Analysis 1994 , 2 , 21 ) (or Eigs of Matlab) but significantly simpler.

  9. Performance of the improved version of Monte Carlo code A 3MCNP for large-scale shielding problems

    International Nuclear Information System (INIS)

    Omura, M.; Miyake, Y.; Hasegawa, T.; Ueki, K.; Sato, O.; Haghighat, A.; Sjoden, G. E.

    2005-01-01

    A 3MCNP (Automatic Adjoint Accelerated MCNP) is a revised version of the MCNP Monte Carlo code, which automatically prepares variance reduction parameters for the CADIS (Consistent Adjoint Driven Importance Sampling) methodology. Using a deterministic 'importance' (or adjoint) function, CADIS performs source and transport biasing within the weight-window technique. The current version of A 3MCNP uses the three-dimensional (3-D) Sn transport TORT code to determine a 3-D importance function distribution. Based on simulation of several real-life problems, it is demonstrated that A 3MCNP provides precise calculation results with a remarkably short computation time by using the proper and objective variance reduction parameters. However, since the first version of A 3MCNP provided only a point source configuration option for large-scale shielding problems, such as spent-fuel transport casks, a large amount of memory may be necessary to store enough points to properly represent the source. Hence, we have developed an improved version of A 3MCNP (referred to as A 3MCNPV) which has a volumetric source configuration option. This paper describes the successful use of A 3MCNPV for a concrete cask neutron and gamma-ray shielding problem, and a PWR dosimetry problem. (authors)

  10. Theory and algorithms for solving large-scale numerical problems. Application to the management of electricity production

    International Nuclear Information System (INIS)

    Chiche, A.

    2012-01-01

    This manuscript deals with large-scale optimization problems, and more specifically with solving the electricity unit commitment problem arising at EDF. First, we focused on the augmented Lagrangian algorithm. The behavior of that algorithm on an infeasible convex quadratic optimization problem is analyzed. It is shown that the algorithm finds a point that satisfies the shifted constraints with the smallest possible shift in the sense of the Euclidean norm and that it minimizes the objective on the corresponding shifted constrained set. The convergence to such a point is realized at a global linear rate, which depends explicitly on the augmentation parameter. This suggests us a rule for determining the augmentation parameter to control the speed of convergence of the shifted constraint norm to zero. This rule has the advantage of generating bounded augmentation parameters even when the problem is infeasible. As a by-product, the algorithm computes the smallest translation in the Euclidean norm that makes the constraints feasible. Furthermore, this work provides solution methods for stochastic optimization industrial problems decomposed on a scenario tree, based on the progressive hedging algorithm introduced by [Rockafellar et Wets, 1991]. We also focus on the convergence of that algorithm. On the one hand, we offer a counter-example showing that the algorithm could diverge if its augmentation parameter is iteratively updated. On the other hand, we show how to recover the multipliers associated with the non-dualized constraints defined on the scenario tree from those associated with the corresponding constraints of the scenario subproblems. Their convergence is also analyzed for convex problems. The practical interest of theses solutions techniques is corroborated by numerical experiments performed on the electric production management problem. We apply the progressive hedging algorithm to a realistic industrial problem. More precisely, we solve the French medium

  11. Optimizing Human Diet Problem Based on Price and Taste Using

    Directory of Open Access Journals (Sweden)

    Hossein EGHBALI

    2012-07-01

    Full Text Available Low price and good taste of foods are regarded as two major factors for optimal human nutrition. Due to price fluctuations and taste diversity, these two factors cannot be certainly and determinately evaluated. This problem must be viewed from another perspective because of the uncertainty about the amount of nutrients per unit of foods and also diversity of people’s daily needs to receive them.This paper discusses human diet problem in fuzzy environment. The approach deals with multi-objective fuzzy linear programming problem using a fuzzy programming technique for its solution. By prescribing a diet merely based on crisp data, some ofthe realities are neglected. For the same reason, we dealt with human diet problem through fuzzy approach. Results indicated uncertainty about factors of nutrition diet -including taste and price, amount of nutrients and their intake- would affect diet quality, making the proposed diet more realistic.

  12. Problem-based learning: Developing resilience in nursing students

    Directory of Open Access Journals (Sweden)

    Jih-Yuan Chen

    2011-06-01

    Full Text Available A society needs mature and confident nurse practitioners, who are able to think analytically and flexibly, recognize needs for further preparation, and willing to engage in self-development. Concern is raised regarding how educators will build the capacity of resilient students with a knowledge base and a minimum set of skills in responding to various issues and for engaging in self-reflection. Drawing on the framework of nursing competencies and global standards for the education of professional nurses, resilient students may contribute through their social competence, problem-solving ability, sense of purpose, and persistence in the process to achieve the goal of the project. Educators should know how to build the resilient attribute in students by encouraging them to engage in self-reflection. This article discusses four areas that help students build resilience from project-based learning of a small group: the impact of problem-based learning at clinical practice, project/problem-based learning, resilient nursing student, and developing nursing students’ resilience. Self-assessment to check the promoting skills for teaching in a problem-based learning program helps the faculty holding the empowerment to encourage or support the students to face the challenge within the small team.

  13. Parallel Optimization of Polynomials for Large-scale Problems in Stability and Control

    Science.gov (United States)

    Kamyar, Reza

    In this thesis, we focus on some of the NP-hard problems in control theory. Thanks to the converse Lyapunov theory, these problems can often be modeled as optimization over polynomials. To avoid the problem of intractability, we establish a trade off between accuracy and complexity. In particular, we develop a sequence of tractable optimization problems --- in the form of Linear Programs (LPs) and/or Semi-Definite Programs (SDPs) --- whose solutions converge to the exact solution of the NP-hard problem. However, the computational and memory complexity of these LPs and SDPs grow exponentially with the progress of the sequence - meaning that improving the accuracy of the solutions requires solving SDPs with tens of thousands of decision variables and constraints. Setting up and solving such problems is a significant challenge. The existing optimization algorithms and software are only designed to use desktop computers or small cluster computers --- machines which do not have sufficient memory for solving such large SDPs. Moreover, the speed-up of these algorithms does not scale beyond dozens of processors. This in fact is the reason we seek parallel algorithms for setting-up and solving large SDPs on large cluster- and/or super-computers. We propose parallel algorithms for stability analysis of two classes of systems: 1) Linear systems with a large number of uncertain parameters; 2) Nonlinear systems defined by polynomial vector fields. First, we develop a distributed parallel algorithm which applies Polya's and/or Handelman's theorems to some variants of parameter-dependent Lyapunov inequalities with parameters defined over the standard simplex. The result is a sequence of SDPs which possess a block-diagonal structure. We then develop a parallel SDP solver which exploits this structure in order to map the computation, memory and communication to a distributed parallel environment. Numerical tests on a supercomputer demonstrate the ability of the algorithm to

  14. A Study on Teaching Gases to Prospective Primary Science Teachers Through Problem-Based Learning

    Science.gov (United States)

    Senocak, Erdal; Taskesenligil, Yavuz; Sozbilir, Mustafa

    2007-07-01

    The aim of this study was to compare the achievement of prospective primary science teachers in a problem-based curriculum with those in a conventional primary science teacher preparation program with regard to success in learning about gases and developing positive attitudes towards chemistry. The subjects of the study were 101 first year undergraduate students, who were in two different classes and who were taught by the same lecturer. One of the classes was randomly selected as the intervention group in which problem-based learning (PBL) was used, and the other as the control in which conventional teaching methods were used. The data were obtained through use of the gases diagnostic test (GDT), the chemistry attitude scale (CAS), and scales specific to students’ evaluation of PBL such as the peer evaluation scale (PES), self evaluation scale (SES), tutor’s performance evaluation scale (TPES) and students’ evaluation of PBL scale (SEPBLS). Data were analysed using SPSS 10.0 (Statistical Package for Social Sciences). In order to find out the effect of the intervention (PBL) on students’ learning of gases, independent sample t-tests and ANCOVA (analysis of co-variance) were used. The results obtained from the study showed that there was a statistically significant difference between the experimental and control groups in terms of students’ GDT total mean scores and, their attitude towards chemistry, as well as PBL has a significant effect on the development of students’ skills such as self-directed learning, cooperative learning and critical thinking.

  15. Teaching Agile Software Engineering Using Problem-Based Learning

    Science.gov (United States)

    El-Khalili, Nuha H.

    2013-01-01

    Many studies have reported the utilization of Problem-Based Learning (PBL) in teaching Software Engineering courses. However, these studies have different views of the effectiveness of PBL. This paper presents the design of an Advanced Software Engineering course for undergraduate Software Engineering students that uses PBL to teach them Agile…

  16. Problem-Based Learning in Engineering Ethics Courses

    Science.gov (United States)

    Kirkman, Robert

    2016-01-01

    I describe the first stages of a process of design research in which I employ problem-based learning in a course in engineering ethics, which fulfills a requirement for students in engineering degree programs. The aim of the course is to foster development of particular cognitive skills contributing to moral imagination, a capacity to notice,…

  17. Medical student's perspective of problem based learning (PBL ...

    African Journals Online (AJOL)

    The Faculty of Health Sciences at the University of Transkei has completed the first 5 years of its problem-based community oriented teaching curriculum. The use of SWOT analysis to evaluate current and future directions can lead to the successful evolution of any organization. The aim of this study was to obtain a students' ...

  18. Teacher interventions in a problem-based hospitality management programme

    NARCIS (Netherlands)

    van Assen, J.H.E.; Meijers, F.; Otting, H.; Poell, R.F.

    2016-01-01

    The purpose of this case study was to investigate to what extent tutor interventions in a problem-based learning environment are in line with a learner-oriented approach to teaching. Using extensive observations, this study demonstrated that the seven tutors in our sample apply predominantly

  19. Learning Radiology in an Integrated Problem-Based Learning (PBL ...

    African Journals Online (AJOL)

    Background: The Faculty of Medicine (FoM) has been training health professions in Uganda since 1924. Five years ago, it decided to change the undergraduate curriculum from traditional to Problem Based Learning (PBL) and adopted the SPICES model. Radiology was integrated into the different courses throughout the 5 ...

  20. Usefulness of problem-based learning in clinical nursing education ...

    African Journals Online (AJOL)

    Problem based learning (PBL) in clinical nursing is described as an effective learning strategy that can encourage students to become self-directed learners and to master clinical skills that can be transferable to service users. This study explores the usefulness of PBL in a nursing clinical setting from the nursing students' ...

  1. Problem-Based Learning in Social Work Education

    DEFF Research Database (Denmark)

    Monrad, Merete; Mølholt, Anne-Kirstine

    2017-01-01

    ’ experiences of PBL. In this article we address this gap by exploring experiences of learning and learning preferences among master’s-level students in a Danish social work education setting where extensive problem-based project work is used. We find a discrepancy between students’ preferred learning and when...

  2. Problem based learning in acoustics at Aalborg University

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Christensen, Flemming

    2010-01-01

    in the project work, or are defining for the candidate's professional profile. This presentation gives an overview of Problem Based Learning organized in groups in the M. Sc. in Acoustics program of Aalborg University. Examples of projects and course activities are presented to illustrate the relation...

  3. Evaluation of a Problem Based Learning Curriculum Using Content Analysis

    Science.gov (United States)

    Prihatiningsih, Titi Savitri; Qomariyah, Nurul

    2016-01-01

    Faculty of Medicine UGM has implemented Problem Based Learning (PBL) since 1985. Seven jump tutorial discussions are applied. A scenario is used as a trigger to stimulate students to identify learning objectives (LOs) in step five which are used as the basis for self study in step six. For each scenario, the Block Team formulates the LOs which are…

  4. Problem-Based Learning for Production and Operations Management

    Science.gov (United States)

    Kanet, John J.; Barut, Mehmet

    2003-01-01

    In this paper, we describe our application of "problem-based learning" in the teaching of production/operations management. We describe a study of the effectiveness of this approach and present the results and analysis of this study. We provide a collection of our experiences in using this method and conclude with some general…

  5. Evaluating potentialities and constrains of Problem Based Learning curriculum

    DEFF Research Database (Denmark)

    Guerra, Aida

    2013-01-01

    This paper presents a research design to evaluate Problem Based Learning (PBL) curriculum potentialities and constrains for future changes. PBL literature lacks examples of how to evaluate and analyse established PBL learning environments to address new challenges posed. The research design......) in the curriculum and a mean to choose cases for further case study (third phase)....

  6. Problem-Based Learning in a General Psychology Course.

    Science.gov (United States)

    Willis, Sandra A.

    2002-01-01

    Describes the adoption of problem-based learning (PBL) techniques in a general psychology course. States that the instructor used a combination of techniques, including think-pair-share, lecture/discussion, and PBL. Notes means and standard deviations for graded components of PBL format versus lecture/discussion format. (Contains 18 references.)…

  7. Implementing Problem-Based Learning in the Counseling Session.

    Science.gov (United States)

    Hall, Kimberly R.

    This study examined the use of problem-based learning (PBL) in an actual counseling session and the effects on student assertiveness skills. A group of seventh-grade students, who were all victims of bullies, participated in the study. The students, two boys and one girls, were 13 and 14 years old. Teachers rated the level of assertiveness skills…

  8. ICT in Problem- and Project-based Learning

    DEFF Research Database (Denmark)

    Andreasen, Lars Birch; Lerche Nielsen, Jørgen

    2012-01-01

    The paper discusses how teaching and learning practices at universities can implement new information technologies, inspired by the traditions of problem- and project-based learning. The changing roles in the teacher-student relationship, and students’ development of information literacy are disc...

  9. How play enhances creativity in problem based learning

    DEFF Research Database (Denmark)

    Thorsted, Ann Charlotte

    2015-01-01

    This article draws on 20 Danish university students’ reflections in and on a Problem-based Learning process (PBL). The study showed how a more playful approach changed how the students collaborated, communicated, and approached a given task. They felt more creative, open minded and engaged compared...... between play and creativity in higher education learning processes?...

  10. "Theory repositories" via the web for problem-based learning

    NARCIS (Netherlands)

    van der Veen, Johan (CTIT); van Riemsdijk, Maarten; Jones, Valerie M.; Collis, Betty

    2000-01-01

    This paper describes a series of experiments conducted at the School of Management Studies at the University of Twente designed to improve students' concentration on the theoretical study materials in a particular course. In 1997 a problem-based learning approach was introduced into a course on

  11. Implementation of Problem-Based Learning in Environmental Chemistry

    Science.gov (United States)

    Jansson, Stina; So¨derstro¨m, Hanna; Andersson, Patrik L.; Nording, Malin L.

    2015-01-01

    Environmental Chemistry covers a range of topics within the discipline of chemistry, from toxicology to legislation, which warrants interdisciplinary study. Consequently, problem-based learning (PBL), a style of student-centered learning which facilitates the integration of multiple subjects, was investigated to determine if it would be a more…

  12. Introduction to Problem Based Learning for Engineering Education

    DEFF Research Database (Denmark)

    Moesby, Egon; Rosenørn, Torben

    2003-01-01

    Documentation material and working papers for the workshop "Introduction to Problem Based Learning for Engineering Education" held at Chiang Mai University, Chiang Mai, Thailand, 6 - 10 October 2003. The material support the workshop where the participants go through a complete pre-planning cycle...

  13. Are marketing students in control in problem-based learning?

    NARCIS (Netherlands)

    Geitz, Gerry; Joosten-ten Brinke, Desirée; Kirschner, Paul A.

    2018-01-01

    This study investigated to what extent self-efficacy, learning behavior, and performance outcomes relate to each other and how they can be positively influenced by students asking for and seeking feedback within a problem-based learning (PBL) environment in order to meet today’s requirements of

  14. From cases to projects in problem-based medical education

    Directory of Open Access Journals (Sweden)

    Diana Stentoft

    2014-06-01

    Full Text Available Problem-based learning (PBL based on patient cases has become a well-established worldwide educational approach in medical education. Recent studies indicate that case-based PBL when used throughout an entire curriculum may develop into a counter-productive routine for students as well as teachers. Consequently, there is a need to develop PBL approaches further allowing students to work with more ill-defined problems and alternative learning structures. In this paper, we argue that this can be realised by introducing project-PBL into the medical curriculum, as in the medical education at Aalborg University, Denmark. We outline organisations of case- and project- PBL in the medical curriculum and present an explorative study of 116 first and second year students’ experiences working in the two settings of PBL. Results reveal that students generally rate their PBL experiences positively however, project-PBL is rated more positively than case-PBL on all parameters studied. These results invite further consideration of the differences in working with cases and projects. Two central differences are discussed; the nature of the problem as the trigger of learning and students' possibilities for directing their own learning processes. The study demonstrates that introducing project-PBL may contribute significantly in problem-based medical education. However, the need for extensive research into advantages and limitations of the combined use of case- and project-PBL is also emphasised.

  15. Advanced prototyping tools for project- and problem-based learning

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Bech, Michael Møller; Holm, Allan J.

    2002-01-01

    A new approach in prototyping for project- and problem-based learning is achieved by using the new Total Development Environment concept introduced by dSPACE that allows a full visual block-oriented programming of dynamic real-time systems to be achieved  using the Matlab/Simulink environment...

  16. The Guinea Pigs of a Problem-Based Learning Curriculum

    Science.gov (United States)

    Reddy, Sarasvathie; McKenna, Sioux

    2016-01-01

    Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as "Guinea pigs" at the mercy of a curriculum experiment. This article interrogates and problematises the "Guinea pig" identity ascribed to and assumed by the first cohort of…

  17. Word-based Morphology: Some Problems from a Polysynthetic Language.

    Science.gov (United States)

    Axelrod, Melissa

    Some of the problems inherent in a word-based hypothesis asserting that the word/stem is taken as the minimal sign not only for syntax but also for morphology are examined in an analysis of a polysynthetic language, Koyukon, an Athabaskan language of Alaska. Data from the Central dialect is considered in the analysis. A brief sketch of the verbal…

  18. A displacement based FE formulation for steady state problems

    NARCIS (Netherlands)

    Yu, Y.

    2005-01-01

    In this thesis a new displacement based formulation is developed for elasto-plastic deformations in steady state problems. In this formulation the displacements are the primary variables, which is in contrast to the more common formulations in terms of the velocities as the primary variables. In a

  19. The Current Practices and Problems of School Based Supervision in ...

    African Journals Online (AJOL)

    The purpose of this study was to identify the current practice and problems of school based supervision in government primary schools of Jile Timuga Woreda of Oromia Zone. A descriptive survey design of research methodology was employed. Regarding sampling, there were 39 primary schools grouped in 10 cluster ...

  20. Designing Digital Problem Based Learning Tasks that Motivate Students

    Science.gov (United States)

    van Loon, Anne-Marieke; Ros, Anje; Martens, Rob

    2013-01-01

    This study examines whether teachers are able to apply the principles of autonomy support and structure support in designing digital problem based learning (PBL) tasks. We examine whether these tasks are more autonomy- and structure-supportive and whether primary and secondary school students experience greater autonomy, competence, and motivation…

  1. Outcomes of Domestic Standard Problem-03 : Scaling Capability of Facility Data

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yusun; Youn, Bumsu; Lee, Seung-won; Kim, Won-tae; Kang, Kyoung-ho; Choi, Ki-yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The Domestic Standard Problem (DSP) previous two DSPs provided good research opportunities to many nuclear organizations to understand the capability of the current system-scale safety analysis codes and to find a way for further code development area. Thus, the third DSP program was launched in the 2nd half of the year 2012. As the third DSP exercise (DSP-03), a double-ended guillotine break of the main steam line at an 8% power without loss of off-site power (LOOP) was decided a target scenario. Seventeen domestic organizations joined this DSP exercise. This DSP exercise was performed in an open calculation environment similar to the previous ones. In the present DSP-03, taking into accounts the different levels of code experiences and expertise, three sub-topics were suggested by operating agency. Among them, the investigation on scaling capability of facility data which was the topic of Group A will be discussed in this paper. Agreed participants should perform two calculations with the ATLAS model and the APR1400 model. By comparing major and detailed local parameters from both calculation models, scaling capability of the facility data was investigated. The 38.6 mm MSLB in ATLAS test facility was calculated using SPACE and MARS-KS code. To analyze the effect of scaling on the system behavior, MSLB in APR-1400 was also simulated in this study and following results were obtained. - The code predicted appropriately the overall MSLB experimental data obtained from ATLAS test facility. - The break flow calculated by code was lower than that of experimental data. - And the difference between calculated value and measured value was attributed to the measurement of mass from break flow. - The temperatures of core inlet and outlet of ATLAS test facility were predicted lower than those of experimental data.

  2. [Problem list in computer-based patient records].

    Science.gov (United States)

    Ludwig, C A

    1997-01-14

    Computer-based clinical information systems are capable of effectively processing even large amounts of patient-related data. However, physicians depend on rapid access to summarized, clearly laid out data on the computer screen to inform themselves about a patient's current clinical situation. In introducing a clinical workplace system, we therefore transformed the problem list-which for decades has been successfully used in clinical information management-into an electronic equivalent and integrated it into the medical record. The table contains a concise overview of diagnoses and problems as well as related findings. Graphical information can also be integrated into the table, and an additional space is provided for a summary of planned examinations or interventions. The digital form of the problem list makes it possible to use the entire list or selected text elements for generating medical documents. Diagnostic terms for medical reports are transferred automatically to corresponding documents. Computer technology has an immense potential for the further development of problem list concepts. With multimedia applications sound and images will be included in the problem list. For hyperlink purpose the problem list could become a central information board and table of contents of the medical record, thus serving as the starting point for database searches and supporting the user in navigating through the medical record.

  3. Web-Based Problem-Solving Assignment and Grading System

    Science.gov (United States)

    Brereton, Giles; Rosenberg, Ronald

    2014-11-01

    In engineering courses with very specific learning objectives, such as fluid mechanics and thermodynamics, it is conventional to reinforce concepts and principles with problem-solving assignments and to measure success in problem solving as an indicator of student achievement. While the modern-day ease of copying and searching for online solutions can undermine the value of traditional assignments, web-based technologies also provide opportunities to generate individualized well-posed problems with an infinite number of different combinations of initial/final/boundary conditions, so that the probability of any two students being assigned identical problems in a course is vanishingly small. Such problems can be designed and programmed to be: single or multiple-step, self-grading, allow students single or multiple attempts; provide feedback when incorrect; selectable according to difficulty; incorporated within gaming packages; etc. In this talk, we discuss the use of a homework/exam generating program of this kind in a single-semester course, within a web-based client-server system that ensures secure operation.

  4. Behavioural problems and autism in children with hydrocephalus : a population-based study.

    Science.gov (United States)

    Lindquist, Barbro; Carlsson, Göran; Persson, Eva-Karin; Uvebrant, Paul

    2006-06-01

    To investigate the prevalence of behavioural problems and autism in a population-based group of children with hydrocephalus and to see whether learning disabilities, cerebral palsy (CP), epilepsy, myelomeningocele (MMC) or preterm birth increase the risk of these problems. In the 107 children with hydrocephalus born in western Sweden in 1989-1993, behaviour was assessed using the Conners' parent rating scales in 66 and the teacher's rating scales in 57. Autism was investigated using the Childhood Autism Rating Scale. Parents rated 67% of the children and teachers 39% of the children as having behavioural problems (>1.5 SD, or T score >65). Learning disabilities increased the risk significantly and almost all the children with CP and/or epilepsy had behavioural problems. Autism was present in nine children (13%), in 20% of those without MMC and in one of 26 with MMC. Autism was significantly more frequent in children with learning disabilities (27% vs. 7%) and in children with CP and/or epilepsy (33% vs. 6%). The majority of children with hydrocephalus have behavioural problems and many have autism. It is therefore important to assess and understand all the aspects of cognition and behaviour in these children in order to minimise disability and enhance participation for the child.

  5. Memristor-based memory: The sneak paths problem and solutions

    KAUST Repository

    Zidan, Mohammed A.

    2012-10-29

    In this paper, we investigate the read operation of memristor-based memories. We analyze the sneak paths problem and provide a noise margin metric to compare the various solutions proposed in the literature. We also analyze the power consumption associated with these solutions. Moreover, we study the effect of the aspect ratio of the memory array on the sneak paths. Finally, we introduce a new technique for solving the sneak paths problem by gating the memory cell using a three-terminal memistor device.

  6. Memristor-based memory: The sneak paths problem and solutions

    KAUST Repository

    Zidan, Mohammed A.; Fahmy, Hossam A.H.; Hussain, Muhammad Mustafa; Salama, Khaled N.

    2012-01-01

    In this paper, we investigate the read operation of memristor-based memories. We analyze the sneak paths problem and provide a noise margin metric to compare the various solutions proposed in the literature. We also analyze the power consumption associated with these solutions. Moreover, we study the effect of the aspect ratio of the memory array on the sneak paths. Finally, we introduce a new technique for solving the sneak paths problem by gating the memory cell using a three-terminal memistor device.

  7. A Danish Perspective on Problem Based Learning in Space Education

    DEFF Research Database (Denmark)

    Bhanderi, Dan D. V.; Bisgaard, Morten; Alminde, Lars

    2006-01-01

    This paper describes the goals of the Student Satellite Program at Aalborg University (AAU), and the means for implementing it, namely a concept called Problem Based Learning, which is the cornerstone in the education at AAU. AAU has within the last decade chosen to focus strongly on education...... in space technology, not because the country lacks aerospace engineers, but because space projects require the students to think about systems rather than individual modules, while providing problems that are technically challenging for the students to solve. This combination makes the graduates very...

  8. Project organized Problem-based learning in Distance Education

    DEFF Research Database (Denmark)

    Jensen, Lars Peter; Helbo, Jan; Knudsen, Morten

    2002-01-01

    Project organized problem based learning is a successful concept for on-campus engineering education at Aalborg University. Recently this "Aalborg concept" has been used in networked distance education as well. This paper describes the experiences from two years of Internet-mediated project work...... in a new Master of Information Technology education. The main conclusions are, that the project work is a strong learning motivator, enhancing peer collaboration, for off-campus students as well. However, the concept cannot be directly transferred to off-campus learning. In this paper, the main problems...... experienced with group organized project work in distance education are described, and some possible solutions are listed....

  9. Project-Organized Problem-Based Learning in Distance Education

    DEFF Research Database (Denmark)

    Jensen, Lars Peter; Helbo, Jan; Knudsen, Morten

    2003-01-01

    Project organized problem based learning is a successful concept for on-campus engineering education at Aalborg University. Recently this "Aalborg concept" has been used in networked distance education as well. This paper describes the experiences from two years of Internet-mediated project work...... in a new Master of Information Technology education. The main conclusions are, that the project work is a strong learning motivator, enhancing peer collaboration, for off-campus students as well. However, the concept cannot be directly transferred to off-campus learning. In this paper, the main problems...... experienced with group organized project work in distance education are described, and some possible solutions are listed....

  10. GPU-based large-scale visualization

    KAUST Repository

    Hadwiger, Markus

    2013-11-19

    Recent advances in image and volume acquisition as well as computational advances in simulation have led to an explosion of the amount of data that must be visualized and analyzed. Modern techniques combine the parallel processing power of GPUs with out-of-core methods and data streaming to enable the interactive visualization of giga- and terabytes of image and volume data. A major enabler for interactivity is making both the computational and the visualization effort proportional to the amount of data that is actually visible on screen, decoupling it from the full data size. This leads to powerful display-aware multi-resolution techniques that enable the visualization of data of almost arbitrary size. The course consists of two major parts: An introductory part that progresses from fundamentals to modern techniques, and a more advanced part that discusses details of ray-guided volume rendering, novel data structures for display-aware visualization and processing, and the remote visualization of large online data collections. You will learn how to develop efficient GPU data structures and large-scale visualizations, implement out-of-core strategies and concepts such as virtual texturing that have only been employed recently, as well as how to use modern multi-resolution representations. These approaches reduce the GPU memory requirements of extremely large data to a working set size that fits into current GPUs. You will learn how to perform ray-casting of volume data of almost arbitrary size and how to render and process gigapixel images using scalable, display-aware techniques. We will describe custom virtual texturing architectures as well as recent hardware developments in this area. We will also describe client/server systems for distributed visualization, on-demand data processing and streaming, and remote visualization. We will describe implementations using OpenGL as well as CUDA, exploiting parallelism on GPUs combined with additional asynchronous

  11. Video-based problems in introductory mechanics physics courses

    International Nuclear Information System (INIS)

    Gröber, Sebastian; Klein, Pascal; Kuhn, Jochen

    2014-01-01

    Introductory mechanics physics courses at the transition from school to university are a challenge for students. They are faced with an abrupt and necessary increase of theoretical content and requirements on their conceptual understanding of phyiscs. In order to support this transition we replaced part of the mandatory weekly theory-based paper-and-pencil problems with video analysis problems of equal content and level of difficulty. Video-based problems (VBP) are a new problem format for teaching physics from a linked sequence of theoretical and video-based experimental tasks. Experimental tasks are related to the well-known concept of video motion analysis. This introduction of an experimental part in recitations allows the establishment of theory–experiment interplay as well as connections between physical content and context fields such as nature, technique, everyday life and applied physics by conducting model-and context-related experiments. Furthermore, laws and formulas as predominantly representative forms are extended by the use of diagrams and vectors. In this paper we give general reasons for this approach, describe the structure and added values of VBP, and show that they cover a relevant part of mechanics courses at university. Emphasis is put on theory–experiment interplay as a structural added value of VBP to promote students' construction of knowledge and conceptual understanding. (paper)

  12. Solution matching for a three-point boundary-value problem on atime scale

    Directory of Open Access Journals (Sweden)

    Martin Eggensperger

    2004-07-01

    Full Text Available Let $mathbb{T}$ be a time scale such that $t_1, t_2, t_3 in mathbb{T}$. We show the existence of a unique solution for the three-point boundary value problem $$displaylines{ y^{DeltaDeltaDelta}(t = f(t, y(t, y^Delta(t, y^{DeltaDelta}(t, quad t in [t_1, t_3] cap mathbb{T},cr y(t_1 = y_1, quad y(t_2 = y_2, quad y(t_3 = y_3,. }$$ We do this by matching a solution to the first equation satisfying a two-point boundary conditions on $[t_1, t_2] cap mathbb{T}$ with a solution satisfying a two-point boundary conditions on $[t_2, t_3] cap mathbb{T}$.

  13. Picosecond scale experimental verification of a globally convergent algorithm for a coefficient inverse problem

    International Nuclear Information System (INIS)

    Klibanov, Michael V; Pantong, Natee; Fiddy, Michael A; Schenk, John; Beilina, Larisa

    2010-01-01

    A globally convergent algorithm by the first and third authors for a 3D hyperbolic coefficient inverse problem is verified on experimental data measured in the picosecond scale regime. Quantifiable images of dielectric abnormalities are obtained. The total measurement timing of a 100 ps pulse for one detector location was 1.2 ns with 20 ps (=0.02 ns) time step between two consecutive readings. Blind tests have consistently demonstrated an accurate imaging of refractive indexes of dielectric abnormalities. At the same time, it is shown that a modified gradient method is inapplicable to this kind of experimental data. This inverse algorithm is also applicable to other types of imaging modalities, e.g. acoustics. Potential applications are in airport security, imaging of land mines, imaging of defects in non-distractive testing, etc

  14. Application of spectral Lanczos decomposition method to large scale problems arising geophysics

    Energy Technology Data Exchange (ETDEWEB)

    Tamarchenko, T. [Western Atlas Logging Services, Houston, TX (United States)

    1996-12-31

    This paper presents an application of Spectral Lanczos Decomposition Method (SLDM) to numerical modeling of electromagnetic diffusion and elastic waves propagation in inhomogeneous media. SLDM approximates an action of a matrix function as a linear combination of basis vectors in Krylov subspace. I applied the method to model electromagnetic fields in three-dimensions and elastic waves in two dimensions. The finite-difference approximation of the spatial part of differential operator reduces the initial boundary-value problem to a system of ordinary differential equations with respect to time. The solution to this system requires calculating exponential and sine/cosine functions of the stiffness matrices. Large scale numerical examples are in a good agreement with the theoretical error bounds and stability estimates given by Druskin, Knizhnerman, 1987.

  15. Computational issues in complex water-energy optimization problems: Time scales, parameterizations, objectives and algorithms

    Science.gov (United States)

    Efstratiadis, Andreas; Tsoukalas, Ioannis; Kossieris, Panayiotis; Karavokiros, George; Christofides, Antonis; Siskos, Alexandros; Mamassis, Nikos; Koutsoyiannis, Demetris

    2015-04-01

    Modelling of large-scale hybrid renewable energy systems (HRES) is a challenging task, for which several open computational issues exist. HRES comprise typical components of hydrosystems (reservoirs, boreholes, conveyance networks, hydropower stations, pumps, water demand nodes, etc.), which are dynamically linked with renewables (e.g., wind turbines, solar parks) and energy demand nodes. In such systems, apart from the well-known shortcomings of water resources modelling (nonlinear dynamics, unknown future inflows, large number of variables and constraints, conflicting criteria, etc.), additional complexities and uncertainties arise due to the introduction of energy components and associated fluxes. A major difficulty is the need for coupling two different temporal scales, given that in hydrosystem modeling, monthly simulation steps are typically adopted, yet for a faithful representation of the energy balance (i.e. energy production vs. demand) a much finer resolution (e.g. hourly) is required. Another drawback is the increase of control variables, constraints and objectives, due to the simultaneous modelling of the two parallel fluxes (i.e. water and energy) and their interactions. Finally, since the driving hydrometeorological processes of the integrated system are inherently uncertain, it is often essential to use synthetically generated input time series of large length, in order to assess the system performance in terms of reliability and risk, with satisfactory accuracy. To address these issues, we propose an effective and efficient modeling framework, key objectives of which are: (a) the substantial reduction of control variables, through parsimonious yet consistent parameterizations; (b) the substantial decrease of computational burden of simulation, by linearizing the combined water and energy allocation problem of each individual time step, and solve each local sub-problem through very fast linear network programming algorithms, and (c) the substantial

  16. Relationship between family history of alcohol addiction, parents’ education level, and smartphone problem use scale scores

    Science.gov (United States)

    Beison, Ashley; Rademacher, David J.

    2017-01-01

    Background and aims Smartphones are ubiquitous. As smartphones increased in popularity, researchers realized that people were becoming dependent on their smartphones. The purpose here was to provide a better understanding of the factors related to problematic smartphone use (PSPU). Methods The participants were 100 undergraduates (25 males, 75 females) whose ages ranged from 18 to 23 (mean age = 20 years). The participants completed questionnaires to assess gender, ethnicity, year in college, father’s education level, mother’s education level, family income, age, family history of alcoholism, and PSPU. The Family Tree Questionnaire assessed family history of alcoholism. The Mobile Phone Problem Use Scale (MPPUS) and the Adapted Cell Phone Addiction Test (ACPAT) were used to determine the degree of PSPU. Whereas the MPPUS measures tolerance, escape from other problems, withdrawal, craving, and negative life consequences, the ACPAT measures preoccupation (salience), excessive use, neglecting work, anticipation, lack of control, and neglecting social life. Results Family history of alcoholism and father’s education level together explained 26% of the variance in the MPPUS scores and 25% of the variance in the ACPAT scores. The inclusion of mother’s education level, ethnicity, family income, age, year in college, and gender did not significantly increase the proportion of variance explained for either MPPUS or ACPAT scores. Discussion and conclusions Family history of alcoholism and father’s education level are good predictors of PSPU. As 74%–75% of the variance in PSPU scale scores was not explained, future studies should aim to explain this variance. PMID:28316252

  17. What is the problem in problem-based learning in higher education mathematics

    Science.gov (United States)

    Dahl, Bettina

    2018-01-01

    Problem and Project-Based Learning (PBL) emphasise collaborate work on problems relevant to society and emphases the relation between theory and practice. PBL fits engineering students as preparation for their future professions but what about mathematics? Mathematics is not just applied mathematics, but it is also a body of abstract knowledge where the application in society is not always obvious. Does mathematics, including pure mathematics, fit into a PBL curriculum? This paper argues that it does for two reasons: (1) PBL resembles the working methods of research mathematicians. (2) The concept of society includes the society of researchers to whom theoretical mathematics is relevant. The paper describes two cases of university PBL projects in mathematics; one in pure mathematics and the other in applied mathematics. The paper also discusses that future engineers need to understand the world of mathematics as well as how engineers fit into a process of fundamental-research-turned-into-applied-science.

  18. Solving the problem of imaging resolution: stochastic multi-scale image fusion

    Science.gov (United States)

    Karsanina, Marina; Mallants, Dirk; Gilyazetdinova, Dina; Gerke, Kiril

    2016-04-01

    Structural features of porous materials define the majority of its physical properties, including water infiltration and redistribution, multi-phase flow (e.g. simultaneous water/air flow, gas exchange between biologically active soil root zone and atmosphere, etc.) and solute transport. To characterize soil and rock microstructure X-ray microtomography is extremely useful. However, as any other imaging technique, this one also has a significant drawback - a trade-off between sample size and resolution. The latter is a significant problem for multi-scale complex structures, especially such as soils and carbonates. Other imaging techniques, for example, SEM/FIB-SEM or X-ray macrotomography can be helpful in obtaining higher resolution or wider field of view. The ultimate goal is to create a single dataset containing information from all scales or to characterize such multi-scale structure. In this contribution we demonstrate a general solution for merging multiscale categorical spatial data into a single dataset using stochastic reconstructions with rescaled correlation functions. The versatility of the method is demonstrated by merging three images representing macro, micro and nanoscale spatial information on porous media structure. Images obtained by X-ray microtomography and scanning electron microscopy were fused into a single image with predefined resolution. The methodology is sufficiently generic for implementation of other stochastic reconstruction techniques, any number of scales, any number of material phases, and any number of images for a given scale. The methodology can be further used to assess effective properties of fused porous media images or to compress voluminous spatial datasets for efficient data storage. Potential practical applications of this method are abundant in soil science, hydrology and petroleum engineering, as well as other geosciences. This work was partially supported by RSF grant 14-17-00658 (X-ray microtomography study of shale

  19. Wetland Planning: Current Problems and Environmental Management Proposals at Supra-Municipal Scale (Spanish Mediterranean Coast

    Directory of Open Access Journals (Sweden)

    María-Teresa Sebastiá-Frasquet

    2014-03-01

    Full Text Available The policies that define the use and management of wetlands in Spain have undergone tremendous changes in recent decades. During the period of 1950–1980, Land Reform Plans promoted filling and draining of these areas for agricultural use. In 1986, with the incorporation of Spain to the European Union (EU, there was a sudden change of direction in these policies, which, thereafter, pursued restoring and protecting these ecosystems. This change, combined with increasing urban development and infrastructure pressures (e.g., roads, golf courses, etc., creates a conflict of uses which complicates the management of these ecosystems by local governments. This study analyzes the effectiveness of policies and management tools of important coastal wetlands at the local scale in the Valencian Community (Western Mediterranean Sea using a strengths-weaknesses-opportunities-threats (SWOT methodology. A supra-municipal model of environmental planning is proposed to enable consistent management at a regional scale. This model enhances local government’s effectiveness and it can be applied in other areas with similar problems.

  20. Equivalent Electromagnetic Constants for Microwave Application to Composite Materials for the Multi-Scale Problem

    Directory of Open Access Journals (Sweden)

    Keisuke Fujisaki

    2013-11-01

    Full Text Available To connect different scale models in the multi-scale problem of microwave use, equivalent material constants were researched numerically by a three-dimensional electromagnetic field, taking into account eddy current and displacement current. A volume averaged method and a standing wave method were used to introduce the equivalent material constants; water particles and aluminum particles are used as composite materials. Consumed electrical power is used for the evaluation. Water particles have the same equivalent material constants for both methods; the same electrical power is obtained for both the precise model (micro-model and the homogeneous model (macro-model. However, aluminum particles have dissimilar equivalent material constants for both methods; different electric power is obtained for both models. The varying electromagnetic phenomena are derived from the expression of eddy current. For small electrical conductivity such as water, the macro-current which flows in the macro-model and the micro-current which flows in the micro-model express the same electromagnetic phenomena. However, for large electrical conductivity such as aluminum, the macro-current and micro-current express different electromagnetic phenomena. The eddy current which is observed in the micro-model is not expressed by the macro-model. Therefore, the equivalent material constant derived from the volume averaged method and the standing wave method is applicable to water with a small electrical conductivity, although not applicable to aluminum with a large electrical conductivity.

  1. A geometrical multi-scale numerical method for coupled hygro-thermo-mechanical problems in photovoltaic laminates.

    Science.gov (United States)

    Lenarda, P; Paggi, M

    A comprehensive computational framework based on the finite element method for the simulation of coupled hygro-thermo-mechanical problems in photovoltaic laminates is herein proposed. While the thermo-mechanical problem takes place in the three-dimensional space of the laminate, moisture diffusion occurs in a two-dimensional domain represented by the polymeric layers and by the vertical channel cracks in the solar cells. Therefore, a geometrical multi-scale solution strategy is pursued by solving the partial differential equations governing heat transfer and thermo-elasticity in the three-dimensional space, and the partial differential equation for moisture diffusion in the two dimensional domains. By exploiting a staggered scheme, the thermo-mechanical problem is solved first via a fully implicit solution scheme in space and time, with a specific treatment of the polymeric layers as zero-thickness interfaces whose constitutive response is governed by a novel thermo-visco-elastic cohesive zone model based on fractional calculus. Temperature and relative displacements along the domains where moisture diffusion takes place are then projected to the finite element model of diffusion, coupled with the thermo-mechanical problem by the temperature and crack opening dependent diffusion coefficient. The application of the proposed method to photovoltaic modules pinpoints two important physical aspects: (i) moisture diffusion in humidity freeze tests with a temperature dependent diffusivity is a much slower process than in the case of a constant diffusion coefficient; (ii) channel cracks through Silicon solar cells significantly enhance moisture diffusion and electric degradation, as confirmed by experimental tests.

  2. Dispositional Insight Scale: Development and Validation of a Tool That Measures Propensity toward Insight in Problem Solving

    Science.gov (United States)

    Ovington, Linda A.; Saliba, Anthony J.; Goldring, Jeremy

    2016-01-01

    This article reports the development of a brief self-report measure of dispositional insight problem solving, the Dispositional Insight Scale (DIS). From a representative Australian database, 1,069 adults (536 women and 533 men) completed an online questionnaire. An exploratory and confirmatory factor analysis revealed a 5-item scale, with all…

  3. Ship Block Transportation Scheduling Problem Based on Greedy Algorithm

    Directory of Open Access Journals (Sweden)

    Chong Wang

    2016-05-01

    Full Text Available Ship block transportation problems are crucial issues to address in reducing the construction cost and improving the productivity of shipyards. Shipyards aim to maximize the workload balance of transporters with time constraint such that all blocks should be transported during the planning horizon. This process leads to three types of penalty time: empty transporter travel time, delay time, and tardy time. This study aims to minimize the sum of the penalty time. First, this study presents the problem of ship block transportation with the generalization of the block transportation restriction on the multi-type transporter. Second, the problem is transformed into the classical traveling salesman problem and assignment problem through a reasonable model simplification and by adding a virtual node to the proposed directed graph. Then, a heuristic algorithm based on greedy algorithm is proposed to assign blocks to available transporters and sequencing blocks for each transporter simultaneously. Finally, the numerical experiment method is used to validate the model, and its result shows that the proposed algorithm is effective in realizing the efficient use of the transporters in shipyards. Numerical simulation results demonstrate the promising application of the proposed method to efficiently improve the utilization of transporters and to reduce the cost of ship block logistics for shipyards.

  4. Harnessing Petaflop-Scale Multi-Core Supercomputing for Problems in Space Science

    Science.gov (United States)

    Albright, B. J.; Yin, L.; Bowers, K. J.; Daughton, W.; Bergen, B.; Kwan, T. J.

    2008-12-01

    The particle-in-cell kinetic plasma code VPIC has been migrated successfully to the world's fastest supercomputer, Roadrunner, a hybrid multi-core platform built by IBM for the Los Alamos National Laboratory. How this was achieved will be described and examples of state-of-the-art calculations in space science, in particular, the study of magnetic reconnection, will be presented. With VPIC on Roadrunner, we have performed, for the first time, plasma PIC calculations with over one trillion particles, >100× larger than calculations considered "heroic" by community standards. This allows examination of physics at unprecedented scale and fidelity. Roadrunner is an example of an emerging paradigm in supercomputing: the trend toward multi-core systems with deep hierarchies and where memory bandwidth optimization is vital to achieving high performance. Getting VPIC to perform well on such systems is a formidable challenge: the core algorithm is memory bandwidth limited with low compute-to-data ratio and requires random access to memory in its inner loop. That we were able to get VPIC to perform and scale well, achieving >0.374 Pflop/s and linear weak scaling on real physics problems on up to the full 12240-core Roadrunner machine, bodes well for harnessing these machines for our community's needs in the future. Many of the design considerations encountered commute to other multi-core and accelerated (e.g., via GPU) platforms and we modified VPIC with flexibility in mind. These will be summarized and strategies for how one might adapt a code for such platforms will be shared. Work performed under the auspices of the U.S. DOE by the LANS LLC Los Alamos National Laboratory. Dr. Bowers is a LANL Guest Scientist; he is presently at D. E. Shaw Research LLC, 120 W 45th Street, 39th Floor, New York, NY 10036.

  5. Facilitating Problem-Based Learning in Teams with Scrum

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2013-01-01

    Project-organised and problem-based learning (POPBL) is becoming increasingly popular across universities all over the world, and hence this, it is also gaining currency in some university-based design educations. At Aalborg University, the curriculum in Industrial Design engineering is no except......Project-organised and problem-based learning (POPBL) is becoming increasingly popular across universities all over the world, and hence this, it is also gaining currency in some university-based design educations. At Aalborg University, the curriculum in Industrial Design engineering...... is no exception: Each semester, students are divided into groups and work with various problems or issues partly defined by themselves within the frame of the semester theme. During the first year at Aalborg University, students are taught how to manage and plan projects independently with the use of common...... planning tools like Gantt charts, schedules and simple resource management practices – tools, which are used throughout the education. However, this paper argues that these common project planning and management practices – typically representing rigid “plan-your-work, then work-your-plan” approaches – do...

  6. Retinal Identification Based on an Improved Circular Gabor Filter and Scale Invariant Feature Transform

    Directory of Open Access Journals (Sweden)

    Xiaoming Xi

    2013-07-01

    Full Text Available Retinal identification based on retinal vasculatures in the retina provides the most secure and accurate means of authentication among biometrics and has primarily been used in combination with access control systems at high security facilities. Recently, there has been much interest in retina identification. As digital retina images always suffer from deformations, the Scale Invariant Feature Transform (SIFT, which is known for its distinctiveness and invariance for scale and rotation, has been introduced to retinal based identification. However, some shortcomings like the difficulty of feature extraction and mismatching exist in SIFT-based identification. To solve these problems, a novel preprocessing method based on the Improved Circular Gabor Transform (ICGF is proposed. After further processing by the iterated spatial anisotropic smooth method, the number of uninformative SIFT keypoints is decreased dramatically. Tested on the VARIA and eight simulated retina databases combining rotation and scaling, the developed method presents promising results and shows robustness to rotations and scale changes.

  7. The problem-based learning (PBL and health education.

    Directory of Open Access Journals (Sweden)

    Carine Moraes Vignochi

    2009-05-01

    Full Text Available The Problem-Based Learning (Problem-Based Learning - PBL has been recognized worldwide as an approach to promote the acquisition of knowledge by students at the same time that helps them develop skills and professional attitudes desirable. Unlike the conventional methods of teaching that use of application problems after the theory was presented, the PBL uses a problem to start, focus and motivate the learning of new concepts 13. In this approach, the student uses different mental processes, such as ability to raise hypotheses, compare, analyze, interpret, and evaluate and develop the ability to take responsibility for their education 11.12. The methodology of PBL has been a valuable tool in shaping the health care professional, with advantages over the traditional method of teaching. However, for its deployment there is a need for considerable institutional effort. Are necessary adjustments, including changes in the way of evaluation, for changes in mindset about the role of teachers in the process teaching / learning, investment in infrastructure, adaptations of the environment, improvement of libraries and other 19,20,21, 22. The process of change in education will bring many challenges, such as a break with traditional models of education and train health professionals with skills to recover the essential dimension of care: the relationship between humans.

  8. Student reactions to problem-based learning in photonics technician education

    Science.gov (United States)

    Massa, Nicholas M.; Donnelly, Judith; Hanes, Fenna

    2014-07-01

    Problem-based learning (PBL) is an instructional approach in which students learn problem-solving and teamwork skills by collaboratively solving complex real-world problems. Research shows that PBL improves student knowledge and retention, motivation, problem-solving skills, and the ability to skillfully apply knowledge in new and novel situations. One of the challenges faced by students accustomed to traditional didactic methods, however, is acclimating to the PBL process in which problem parameters are often ill-defined and ambiguous, often leading to frustration and disengagement with the learning process. To address this problem, the New England Board of Higher Education (NEBHE), funded by the National Science Foundation Advanced Technological Education (NSF-ATE) program, has created and field tested a comprehensive series of industry-based multimedia PBL "Challenges" designed to scaffold the development of students' problem solving and critical thinking skills. In this paper, we present the results of a pilot study conducted to examine student reactions to the PBL Challenges in photonics technician education. During the fall 2012 semester, students (n=12) in two associate degree level photonics courses engaged in PBL using the PBL Challenges. Qualitative and quantitative methods were used to assess student motivation, self-efficacy, critical thinking, metacognitive self-regulation, and peer learning using selected scales from the Motivated Strategies for Learning Questionnaire (MSLQ). Results showed positive gains in all variables. Follow-up focus group interviews yielded positive themes supporting the effectiveness of PBL in developing the knowledge, skills and attitudes of photonics technicians.

  9. Evaluation of the Problem Behavior Frequency Scale-Teacher Report Form for Assessing Behavior in a Sample of Urban Adolescents.

    Science.gov (United States)

    Farrell, Albert D; Goncy, Elizabeth A; Sullivan, Terri N; Thompson, Erin L

    2018-02-01

    This study evaluated the structure and validity of the Problem Behavior Frequency Scale-Teacher Report Form (PBFS-TR) for assessing students' frequency of specific forms of aggression and victimization, and positive behavior. Analyses were conducted on two waves of data from 727 students from two urban middle schools (Sample 1) who were rated by their teachers on the PBFS-TR and the Social Skills Improvement System (SSIS), and on data collected from 1,740 students from three urban middle schools (Sample 2) for whom data on both the teacher and student report version of the PBFS were obtained. Confirmatory factor analyses supported first-order factors representing 3 forms of aggression (physical, verbal, and relational), 3 forms of victimization (physical, verbal and relational), and 2 forms of positive behavior (prosocial behavior and effective nonviolent behavior), and higher-order factors representing aggression, victimization, and positive behavior. Strong measurement invariance was established over gender, grade, intervention condition, and time. Support for convergent validity was found based on correlations between corresponding scales on the PBFS-TR and teacher ratings on the SSIS in Sample 1. Significant correlations were also found between teacher ratings on the PBFS-TR and student ratings of their behavior on the Problem Behavior Frequency Scale-Adolescent Report (PBFS-AR) and a measure of nonviolent behavioral intentions in Sample 2. Overall the findings provided support for the PBFS-TR and suggested that teachers can provide useful data on students' aggressive and prosocial behavior and victimization experiences within the school setting. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  10. Nesting, Subsidiarity, and Community-based environmental Governance beyond the Local Scale

    Directory of Open Access Journals (Sweden)

    Graham Marshall

    2007-11-01

    Full Text Available Community-based approaches to environmental management have become widely adopted over the last two decades. From their origins in grassroots frustrations with governmental inabilities to solve local environmental problems, these approaches are now sponsored frequently by governments as a way of dealing with such problems at much higher spatial levels. However, this 'up-scaling' of community-based approaches has run well ahead of knowledge about how they might work. This article explores how Elinor Ostrom's 'nesting principle' for robust common property governance of large-scale common-pool resources might inform future up-scaling efforts. In particular, I consider how the design of nested governance systems for large-scale environmental problems might be guided by the principle of subsidiarity. The challenges of applying this principle are illustrated by Australia's experience in up-scaling community-based natural resource management from local groups comprising 20-30 members to regional bodies representing hundreds of thousands of people. Seven lessons are distilled for fostering community-based environmental governance as a multi-level system of nested enterprises.

  11. Development of a scale to measure problem use of short message service: the SMS Problem Use Diagnostic Questionnaire.

    Science.gov (United States)

    Rutland, J Brian; Sheets, Tilman; Young, Tony

    2007-12-01

    This exploratory study examines a subset of mobile phone use, the compulsive use of short message service (SMS) text messaging. A measure of SMS use, the SMS Problem Use Diagnostic Questionnaire (SMS-PUDQ), was developed and found to possess acceptable reliability and validity when compared to other measures such as self-reports of time spent using SMS and scores on a survey of problem mobile phone use. Implications for the field of addiction research, technological and behavioral addictions in particular, are discussed, and directions for future research are suggested.

  12. Statistical amplitude scale estimation for quantization-based watermarking

    NARCIS (Netherlands)

    Shterev, I.D.; Lagendijk, I.L.; Heusdens, R.

    2004-01-01

    Quantization-based watermarking schemes are vulnerable to amplitude scaling. Therefore the scaling factor has to be accounted for either at the encoder, or at the decoder, prior to watermark decoding. In this paper we derive the marginal probability density model for the watermarked and attacked

  13. High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems

    Science.gov (United States)

    Mahadevan, Vijay S.; Merzari, Elia; Tautges, Timothy; Jain, Rajeev; Obabko, Aleksandr; Smith, Michael; Fischer, Paul

    2014-01-01

    An integrated multi-physics simulation capability for the design and analysis of current and future nuclear reactor models is being investigated, to tightly couple neutron transport and thermal-hydraulics physics under the SHARP framework. Over several years, high-fidelity, validated mono-physics solvers with proven scalability on petascale architectures have been developed independently. Based on a unified component-based architecture, these existing codes can be coupled with a mesh-data backplane and a flexible coupling-strategy-based driver suite to produce a viable tool for analysts. The goal of the SHARP framework is to perform fully resolved coupled physics analysis of a reactor on heterogeneous geometry, in order to reduce the overall numerical uncertainty while leveraging available computational resources. The coupling methodology and software interfaces of the framework are presented, along with verification studies on two representative fast sodium-cooled reactor demonstration problems to prove the usability of the SHARP framework. PMID:24982250

  14. Problem Based Internship in Surveying and Planning Curricula

    DEFF Research Database (Denmark)

    Sørensen, Esben Munk; Enemark, Stig

    2006-01-01

    Programme has been divided into a 3 year Bachelor-Programme and after this a 2 year Master-Programme. It has been done as a part of a governmental policy to adapt and fulfil the Bologna-charter in all University Curricula in Denmark. A new element in the Master Programme is a problem-based internship...... economy and – leadership”. This course is organized as an e-Learning course and the student has to develop and document their skills to follow distance e-learning courses. It will prepare them to follow and organize self paced learning in virtual environment which will develop their capacity for life...... by the society to serve the community with still more new knowledge and technology transfer from the international research community. The internship and still more real world influenced problem based learning by writing thesis will be and important bridge builder in the following years....

  15. Image Based Solution to Occlusion Problem for Multiple Robots Navigation

    Directory of Open Access Journals (Sweden)

    Taj Mohammad Khan

    2012-04-01

    Full Text Available In machine vision, occlusions problem is always a challenging issue in image based mapping and navigation tasks. This paper presents a multiple view vision based algorithm for the development of occlusion-free map of the indoor environment. The map is assumed to be utilized by the mobile robots within the workspace. It has wide range of applications, including mobile robot path planning and navigation, access control in restricted areas, and surveillance systems. We used wall mounted fixed camera system. After intensity adjustment and background subtraction of the synchronously captured images, the image registration was performed. We applied our algorithm on the registered images to resolve the occlusion problem. This technique works well even in the existence of total occlusion for a longer period.

  16. A problem-based learning curriculum for occupational therapy education.

    Science.gov (United States)

    Royeen, C B

    1995-04-01

    To prepare practitioners and researchers who are well equipped to deal with the inevitable myriad changes in health care and in society coming in the 21st century, a new focus is needed in occupational therapy education. In addition to proficiency in clinical skills and technical knowledge, occupational therapy graduates will need outcome competencies underlying the skills of critical reflection. In this article, the author presents (a) the rationale for the need for change in occupational therapy education, (b) key concepts of clinical reasoning and critical reflection pertaining to the outcome such change in occupational therapy education should address, (c) problem-based learning as a process and educational method to prepare occupational therapists in these competencies, and (d) the experience of the Program in Occupational Therapy at Shenandoah University in Winchester, Virginia, in implementing a problem-based learning curriculum.

  17. [The opinion of teachers about tutorial problem based learning].

    Science.gov (United States)

    Navarro H, Nancy; Zamora S, José

    2014-08-01

    In 2004 the Faculty of Medicine of Universidad de La Frontera in Chile implemented curricular changes, incorporating small group problem based learning in different carriers. To explore aspects that hamper or facilitate tutorial problem based learning from the perspective of tutors. Six in depth interviews and a focus group with tutors were carried out in 2010 and 2011. Data were analyzed through constant comparisons using the program ATLAS ti, guaranteeing credibility, reliance, validation and transferability. Five hundred and twenty eight (528) significance units were identified and 25 descriptive categories emerged. The categories of tutor motivation, methodological domain, tutor responsibility, tutor critical capacity, disciplinary domain, student participation and tutor-student interaction were emphasized. Three qualitative domains were generated, namely tutor skills, transformation of student roles and institutional commitment. Tutorial teaching is favored by teachers when the institutions train them in the subject, when there is administrative support and an adequate infrastructure and coordination.

  18. An Educational Approach to Problem-based Learning

    Directory of Open Access Journals (Sweden)

    Nan-Chieh Chen

    2008-03-01

    Full Text Available This paper provides an analysis of the educational framework of problem-based learning (PBL. As known and used, PBL finds its root in the Structuralism and Pragmatism schools of philosophy. In this paper, the three main requirements of PBL, namely learning by doing, learning in context, and focusing on the student, are discussed within the context of these two schools of thought. Given these attributes, PBL also seems ideally suited for use in learning bioethics.

  19. Adaptive probabilistic collocation based Kalman filter for unsaturated flow problem

    Science.gov (United States)

    Man, J.; Li, W.; Zeng, L.; Wu, L.

    2015-12-01

    The ensemble Kalman filter (EnKF) has gained popularity in hydrological data assimilation problems. As a Monte Carlo based method, a relatively large ensemble size is usually required to guarantee the accuracy. As an alternative approach, the probabilistic collocation based Kalman filter (PCKF) employs the Polynomial Chaos to approximate the original system. In this way, the sampling error can be reduced. However, PCKF suffers from the so called "cure of dimensionality". When the system nonlinearity is strong and number of parameters is large, PCKF is even more computationally expensive than EnKF. Motivated by recent developments in uncertainty quantification, we propose a restart adaptive probabilistic collocation based Kalman filter (RAPCKF) for data assimilation in unsaturated flow problem. During the implementation of RAPCKF, the important parameters are identified and active PCE basis functions are adaptively selected. The "restart" technology is used to alleviate the inconsistency between model parameters and states. The performance of RAPCKF is tested by unsaturated flow numerical cases. It is shown that RAPCKF is more efficient than EnKF with the same computational cost. Compared with the traditional PCKF, the RAPCKF is more applicable in strongly nonlinear and high dimensional problems.

  20. List-Based Simulated Annealing Algorithm for Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Shi-hua Zhan

    2016-01-01

    Full Text Available Simulated annealing (SA algorithm is a popular intelligent optimization algorithm which has been successfully applied in many fields. Parameters’ setting is a key factor for its performance, but it is also a tedious work. To simplify parameters setting, we present a list-based simulated annealing (LBSA algorithm to solve traveling salesman problem (TSP. LBSA algorithm uses a novel list-based cooling schedule to control the decrease of temperature. Specifically, a list of temperatures is created first, and then the maximum temperature in list is used by Metropolis acceptance criterion to decide whether to accept a candidate solution. The temperature list is adapted iteratively according to the topology of the solution space of the problem. The effectiveness and the parameter sensitivity of the list-based cooling schedule are illustrated through benchmark TSP problems. The LBSA algorithm, whose performance is robust on a wide range of parameter values, shows competitive performance compared with some other state-of-the-art algorithms.

  1. Evaluation of problem-based learning in medical students’ education

    Directory of Open Access Journals (Sweden)

    MOHAMMAD HADI IMANIEH

    2014-01-01

    Full Text Available Introduction: In traditional medical education systems much interest is placed on the cramming of basic and clinical facts without considering their applicability in the future professional career. The aim of this study is to evaluate a novice medical training method (problem-based learning as compared to the contemporary teacher-based medical education or traditional methods. Methods: Selection of the study subjects was done through simple sampling and according to the division of medical students introduced from Medical Faculty to the Pediatrics Department with no personal involvement. 120 medical students were assigned to 8 groups of 15 students each. For four months, 4 groups were trained with traditional method and 4 other groups underwent problem-based learning method on selected subject materials. In each method, a pre-course test at the beginning and a post-course test at the end of each course were given to each group. The questionnaire used in this study as the instrument was composed of 39 questions, 37 multiple choice questions and two short answer questions. Three professors of pediatric gastroenterologist took part in the training. Two of these professors were responsible for solving task training method. The third professor used traditional teacher-centered methodology to eliminate any possible bias. Scores obtained from these tests were analyzed using paired t-test and independent t-test. P values of less than 0.05 were considered as significant. Results: The scores of the students undergoing the traditional method were 14.70±3.03 and 21.20±4.07 in the first and second test, respectively. In problembased learning, the scores were 15.82±3.29 in the first and 27.52±4.72 in the second test. There was a significant difference between the mean scores of post-course exams of the two groups (p=0.001, while no significant difference was observed between the mean scores of pre-course exams of the groups (p=0.550. Conclusion: It may be

  2. The Mercury Problem in Artisanal and Small-Scale Gold Mining.

    Science.gov (United States)

    Esdaile, Louisa J; Chalker, Justin M

    2018-05-11

    Mercury-dependent artisanal and small-scale gold mining (ASGM) is the largest source of mercury pollution on Earth. In this practice, elemental mercury is used to extract gold from ore as an amalgam. The amalgam is typically isolated by hand and then heated-often with a torch or over a stove-to distill the mercury and isolate the gold. Mercury release from tailings and vaporized mercury exceed 1000 tonnes each year from ASGM. The health effects on the miners are dire, with inhaled mercury leading to neurological damage and other health issues. The communities near these mines are also affected due to mercury contamination of water and soil and subsequent accumulation in food staples, such as fish-a major source of dietary protein in many ASGM regions. The risks to children are also substantial, with mercury emissions from ASGM resulting in both physical and mental disabilities and compromised development. Between 10 and 19 million people use mercury to mine for gold in more than 70 countries, making mercury pollution from ASGM a global issue. With the Minamata Convention on Mercury entering force this year, there is political motivation to help overcome the problem of mercury in ASGM. In this effort, chemists can play a central role. Here, the problem of mercury in ASGM is reviewed with a discussion on how the chemistry community can contribute solutions. Introducing portable and low-cost mercury sensors, inexpensive and scalable remediation technologies, novel methods to prevent mercury uptake in fish and food crops, and efficient and easy-to-use mercury-free mining techniques are all ways in which the chemistry community can help. To meet these challenges, it is critical that new technologies or techniques are low-cost and adaptable to the remote and under-resourced areas in which ASGM is most common. The problem of mercury pollution in ASGM is inherently a chemistry problem. We therefore encourage the chemistry community to consider and address this issue that

  3. SDG and qualitative trend based model multiple scale validation

    Science.gov (United States)

    Gao, Dong; Xu, Xin; Yin, Jianjin; Zhang, Hongyu; Zhang, Beike

    2017-09-01

    Verification, Validation and Accreditation (VV&A) is key technology of simulation and modelling. For the traditional model validation methods, the completeness is weak; it is carried out in one scale; it depends on human experience. The SDG (Signed Directed Graph) and qualitative trend based multiple scale validation is proposed. First the SDG model is built and qualitative trends are added to the model. And then complete testing scenarios are produced by positive inference. The multiple scale validation is carried out by comparing the testing scenarios with outputs of simulation model in different scales. Finally, the effectiveness is proved by carrying out validation for a reactor model.

  4. A DE-Based Scatter Search for Global Optimization Problems

    Directory of Open Access Journals (Sweden)

    Kun Li

    2015-01-01

    Full Text Available This paper proposes a hybrid scatter search (SS algorithm for continuous global optimization problems by incorporating the evolution mechanism of differential evolution (DE into the reference set updated procedure of SS to act as the new solution generation method. This hybrid algorithm is called a DE-based SS (SSDE algorithm. Since different kinds of mutation operators of DE have been proposed in the literature and they have shown different search abilities for different kinds of problems, four traditional mutation operators are adopted in the hybrid SSDE algorithm. To adaptively select the mutation operator that is most appropriate to the current problem, an adaptive mechanism for the candidate mutation operators is developed. In addition, to enhance the exploration ability of SSDE, a reinitialization method is adopted to create a new population and subsequently construct a new reference set whenever the search process of SSDE is trapped in local optimum. Computational experiments on benchmark problems show that the proposed SSDE is competitive or superior to some state-of-the-art algorithms in the literature.

  5. Project- Based Learning and Problem-Based Learning: Are They Effective to Improve Student's Thinking Skills?

    OpenAIRE

    Anazifa, R. D; Djukri, D

    2017-01-01

    The study aims at finding (1) the effect of project-based learning and problem-based learning on student's creativity and critical thinking and (2) the difference effect of project-based learning and problem-based learning on student's creativity and critical thinking. This study is quasi experiment using non-equivalent control-group design. Research population of this study was all classes in eleventh grade of mathematics and natural science program of SMA N 1 Temanggung. The participants we...

  6. ICT-Supported Problem-Based Learning: Possibilities of Applying Problem-Based Learning from Primary School to Higher Education

    Directory of Open Access Journals (Sweden)

    Czékmán Balázs

    2016-06-01

    Full Text Available Problem Based Learning was originally created for medical students to better diagnose new illnesses; this methodology can be used in almost all the fields of education. Teachers can teach by appealing to students’ natural instincts to create, and they can improve the students’ performance in different disciplines. So, we can say that it is an easy way of the acquisition and integration of new knowledge. While the content and structure of PBL courses may differ, the general goals and learning objectives tend to be similar. It begins with the assumption that learning is an active, integrated, and constructive process influenced by social and contextual factors. The task of our paper is to show how Problem-Based Learning can be used from primary to university level education in teaching different subjects.

  7. The Application of Problem-Based Learning in Mechanical Engineering

    Science.gov (United States)

    Putra, Z. A.; Dewi, M.

    2018-02-01

    The course of Technology and Material Testing prepare students with the ability to do a variety of material testing in the study of mechanical engineering. Students find it difficult to understand the materials to make them unable to carry out the material testing in accordance with the purpose of study. This happens because they knowledge is not adequately supported by the competence to find and construct learning experience. In this study, quasy experiment research method with pre-post-test with control group design was used. The subjects of the study were students divided in two groups; control and experiment with twenty-two students in each group. Study result: their grades showed no difference in between the pre-test or post-test in control group, but the difference in grade existed between the pre-test and post-test in experiment group. Yet, there is no significant difference in the study result on both groups. The researcher recommend that it is necessary to develop Problem-Based Learning that suits need analysis on D3 Program for Mechanical Engineering Department at the State University of Padang, to ensure the compatibility between Model of Study and problems and need. This study aims to analyze how Problem-Based Learning effects on the course of Technology and Material Testing for the students of D3 Program of Mechanical Engineering of the State University of Padang.

  8. Solving Inventory Routing Problems Using Location Based Heuristics

    Directory of Open Access Journals (Sweden)

    Paweł Hanczar

    2014-01-01

    Full Text Available Inventory routing problems (IRPs occur where vendor managed inventory replenishment strategies are implemented in supply chains. These problems are characterized by the presence of both transportation and inventory considerations, either as parameters or constraints. The research presented in this paper aims at extending IRP formulation developed on the basis of location based heuristics proposed by Bramel and Simchi-Levi and continued by Hanczar. In the first phase of proposed algorithms, mixed integer programming is used to determine the partitioning of customers as well as dates and quantities of deliveries. Then, using 2-opt algorithm for solving the traveling sales-person problem the optimal routes for each partition are determined. In the main part of research the classical formulation is extended by additional constraints (visit spacing, vehicle filling rate, driver (vehicle consistency, and heterogeneous fleet of vehicles as well as the additional criteria are discussed. Then the impact of using each of proposed extensions for solution possibilities is evaluated. The results of computational tests are presented and discussed. Obtained results allow to conclude that the location based heuristics should be considered when solving real life instances of IRP. (original abstract

  9. The Effect of Problem Based Learning (PBL) Instruction on Students' Motivation and Problem Solving Skills of Physics

    Science.gov (United States)

    Argaw, Aweke Shishigu; Haile, Beyene Bashu; Ayalew, Beyene Tesfaw; Kuma, Shiferaw Gadisa

    2017-01-01

    Through the learning of physics, students will acquire problem solving skills which are relevant to their daily life. Determining the best way in which students learn physics takes a priority in physics education. The goal of the present study was to determine the effect of problem based learning strategy on students' problem solving skills and…

  10. Does Problem-Based Learning Improve Problem Solving Skills?--A Study among Business Undergraduates at Malaysian Premier Technical University

    Science.gov (United States)

    Kadir, Z. Abdul; Abdullah, N. H.; Anthony, E.; Salleh, B. Mohd; Kamarulzaman, R.

    2016-01-01

    Problem-based Learning (PBL) approach has been widely used in various disciplines since it is claimed to improve students' soft skills. However, empirical supports on the effect of PBL on problem solving skills have been lacking and anecdotal in nature. This study aimed to determine the effect of PBL approach on students' problem solving skills…

  11. Applying a Problem Based Learning Approach to Land Management Education

    DEFF Research Database (Denmark)

    Enemark, Stig

    Land management covers a wide range activities associated with the management of land and natural resources that are required to fulfil political objectives and achieve sustainable development. This paper presents an overall understanding of the land management paradigm and the benefits of good...... land governance to society. A land administration system provides a country with the infrastructure to implement land-related policies and land management strategies. By applying this land management profile to surveying education, this paper suggests that there is a need to move away from an exclusive...... engineering focus toward adopting an interdisciplinary and problem-based approach to ensure that academic programmes can cope with the wide range of land administration functions and challenges. An interdisciplinary approach to surveying education calls for the need to address issues and problems in a real...

  12. Problem-Based Learning and Information Literacy: A Natural Partnership

    Directory of Open Access Journals (Sweden)

    Kate Wenger

    2014-11-01

    Full Text Available Due to student overreliance on search engines and the time constraints of one-shot instruction sessions, librarians struggle to teach many of the information literacy skills that students need to conduct successful research. Problem-based learning (PBL provides a way to integrate information literacy naturally into an assignment or course by guiding students through the research process as they work to find a solution to a problem. This article first explains the PBL process, then describes the design and implementation of a PBL project in a required first-year general education course. Finally, it details the Association of College & Research Libraries’ (ACRL Information Literacy Competency Standards for Higher Education addressed by the project, as well as possible future modifications.

  13. [Problem-based learning in cardiopulmonary resuscitation: basic life support].

    Science.gov (United States)

    Sardo, Pedro Miguel Garcez; Dal Sasso, Grace Terezinha Marcon

    2008-12-01

    Descriptive and exploratory study, aimed to develop an educational practice of Problem-Based Learning in CPR/BLS with 24 students in the third stage of the Nursing Undergraduate Course in a University in the Southern region of Brazil. The study used the PBL methodology, focused on problem situations of cardiopulmonary arrest, and was approved by the CONEP. The methodological strategies for data collection, such as participative observation and questionnaires to evaluate the learning, the educational practices and their methodology, allowed for grouping the results in: students' expectations; group activities; individual activities; practical activities; evaluation of the meetings and their methodology. The study showed that PBL allows the educator to evaluate the academic learning process in several dimensions, functioning as a motivating factor for both the educator and the student, because it allows the theoretical-practical integration in an integrated learning process.

  14. Problem-based learning in a health sciences librarianship course.

    Science.gov (United States)

    Dimitroff, A; Ancona, A M; Beman, S B; Dodge, A M; Hutchinson, K L; LaBonte, M J; Mays, T L; Simon, D T

    1998-01-01

    Problem-based learning (PBL) has been adopted by many medical schools in North America. Because problem solving, information seeking, and lifelong learning skills are central to the PBL curriculum, health sciences librarians have been actively involved in the PBL process at these medical schools. The introduction of PBL in a library and information science curriculum may be appropriate to consider at this time. PBL techniques have been incorporated into a health sciences librarianship course at the School of Library and Information Science (LIS) at the University of Wisconsin-Milwaukee to explore the use of this method in an advanced Library and Information Science course. After completion of the course, the use of PBL has been evaluated by the students and the instructor. The modified PBL course design is presented and the perceptions of the students and the instructor are discussed. PMID:9681169

  15. Solutions to a combined problem of excessive hydrogen sulfide in biogas and struvite scaling.

    Science.gov (United States)

    Charles, W; Cord-Ruwisch, R; Ho, G; Costa, M; Spencer, P

    2006-01-01

    The Woodman Point Wastewater Treatment Plant (WWTP) in Western Australia has experienced two separate problems causing avoidable maintenance costs: the build-up of massive struvite (MgNH4PO4. 6H2O) scaling downstream of the anaerobic digester and the formation of hydrogen sulfide (H2S) levels in the digester gas to levels that compromised gas engine operation and caused high operating costs on the gas scrubber. As both problems hang together with a chemical imbalance in the anaerobic digester, we decided to investigate whether both problems could be (feasibly and economically) addressed by a common solution (such as dosing of iron solutions to precipitate both sulfide and phosphate), or by using separate approaches. Laboratory results showed that, the hydrogen sulfide emission in digesters could be effectively and economically controlled by the addition of iron dosing. Slightly higher than the theoretical value of 1.5 mol of FeCl3 was required to precipitate 1 mol of dissolved sulfide inside the digester. Due to the high concentration of PO4(3-) in the digested sludge liquor, significantly higher iron is required for struvite precipitation. Iron dosing did not appear an economic solution for struvite control via iron phosphate formation. By taking advantage of the natural tendency of struvite formation in the digester liquid, it is possible to reduce the risk of struvite precipitation in and around the sludge-dewatering centrifuge by increasing the pH to precipitate struvite out before passing through the centrifuge. However, as the Mg2+/PO4(3-) molar ratio in digested sludge was low, by increasing the pH alone (using NaOH) the precipitation of PO4(3-) was limited by the amount of cations (Ca2+ and Mg2+) available in the sludge. Although this would reduce struvite precipitation in the centrifuge, it could not significantly reduce PO4(3-) recycling back to the plant. For long-term operation, maximum PO4(3-) reduction should be the ultimate aim to minimise PO4

  16. PENGARUH PROBLEM BASED LEARNING TERHADAP KETERAMPILAN BERPIKIR KRITIS DAN REGULASI DIRI SISWA KELAS V

    Directory of Open Access Journals (Sweden)

    Pricilla Anindyta

    2014-07-01

    ,021. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________ THE EFFECT OF APPLYING PROBLEM-BASED LEARNING TO CRITICAL THINKING SKILL AND SELF-REGULATION OF 5TH GRADERS ABSTRACT The objective of this research is to know: (1 the difference between the student’s critical thinking skills and self regulation of the classes taught using problem based learning and expository learning, and (2 the effect of applying problem-based learning to student’s critical thinking skill and self-regulation. This research is a quasi-experimental research study. The population of this research is all 5th graders of St. Vincentius, Jakarta. In the experimental class, science study was done by problem-based learning model, while in the control class by expository learning model. The instruments used are (1 a test to measure students’ critical thinking skill reviewed from the cognitive aspect, (2 a scale of behavior to measure critical thinking skill reviewed from the behavioral aspect and students’ self-regulation. Data analysis used (1 descriptive statistics to describe the data of students’ critical thinking skill and self-regulation, and (2 inferential statistic by using independent sample t-test and MANOVA test to test the hypothesis of research with the significance level of 5% (α = 0,05.The results of this reseach have shown that: (1 there is a difference between the student’s critical thinking skills of the classes taught using problem based learning and expository learning, with sig 0.040; (2 there is a difference between the student’s self regulation of the classes taught using problem based learning and expository learning, with sig 0.005; (3 the application of problem-based learning positively and significantly influences students’ critical thinking skill dan self regulation, with sig 0.021. Keywords: problem-based learning, expository learning, critical thinking skill, self-regulation.

  17. Asymptotic analysis of SPTA-based algorithms for no-wait flow shop scheduling problem with release dates.

    Science.gov (United States)

    Ren, Tao; Zhang, Chuan; Lin, Lin; Guo, Meiting; Xie, Xionghang

    2014-01-01

    We address the scheduling problem for a no-wait flow shop to optimize total completion time with release dates. With the tool of asymptotic analysis, we prove that the objective values of two SPTA-based algorithms converge to the optimal value for sufficiently large-sized problems. To further enhance the performance of the SPTA-based algorithms, an improvement scheme based on local search is provided for moderate scale problems. New lower bound is presented for evaluating the asymptotic optimality of the algorithms. Numerical simulations demonstrate the effectiveness of the proposed algorithms.

  18. Asymptotic Analysis of SPTA-Based Algorithms for No-Wait Flow Shop Scheduling Problem with Release Dates

    Directory of Open Access Journals (Sweden)

    Tao Ren

    2014-01-01

    Full Text Available We address the scheduling problem for a no-wait flow shop to optimize total completion time with release dates. With the tool of asymptotic analysis, we prove that the objective values of two SPTA-based algorithms converge to the optimal value for sufficiently large-sized problems. To further enhance the performance of the SPTA-based algorithms, an improvement scheme based on local search is provided for moderate scale problems. New lower bound is presented for evaluating the asymptotic optimality of the algorithms. Numerical simulations demonstrate the effectiveness of the proposed algorithms.

  19. Problem and Project Based Learning in Hybrid Spaces

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien

    2016-01-01

    There is a need within networked learning to understand and conceptualise the interplay between digital and physical spaces or what we could term hybrid spaces. Therefore, we discuss a recent study of students from two different programmes who are engaged in long-term, group-based problem...... and project based learning. Based on interviews, workshops and observations of students’ actual group practices in open, shared and flexible spaces in Aalborg University (AAU), we identify and discuss how students incorporate networked and digital technologies into their group work and into the study places...... they create for themselves. We describe how in one of the programmes ‘nomadic’ groups of students used different technologies and spaces for ‘placemaking’. We then show how their experience and approach to collaborative work differs to that of the more static or ‘artisan’ groups of students in the other...

  20. The Czech base of hard coal, problems, possibilities for utilization

    International Nuclear Information System (INIS)

    Cermak, T.; Roubicek, V.

    1993-01-01

    The Czech coal and power engineering base is in a deep restructuring period now. The basic problems represents the changeover from the system of the centrally planned state economy to the market model of the energy resources mining, production and consumption. The Czech economy will have to face to up to now unknown competitive forces on the coal market in Europe where American, Canadian, Australian and South African coals compete. The paper discusses historical aspects of the development of the coal mining industry in the Czechoslavakia, the present coal preparation techniques for coking coals, the coking industry, and the utilization of brown coal. How to utilize the domestic coal base and coal generally is closely connected with the global restructuralization of the Czech economy. The most difficult step of this process is undoubtedly the adaptation of the Czech fuel and energy base to the market economy conditions

  1. Role-playing in the problem-based learning class.

    Science.gov (United States)

    Chan, Zenobia C Y

    2012-01-01

    Learning and teaching have been conceptualized and executed in many styles, such as self-learning, peer learning, and interaction between the learner and mentor. Today, openness to alternative ideas and embracing innovative approaches in nursing education are encouraged in order to meet students' learning interests and needs, and to address ever-changing healthcare requests. Problem-based learning has been widely adopted in nursing education, with various positive effects on students' learning, such as motivated learning, team work, problem-solving skills and critical thinking. Role-plays have been demonstrated as an effective learning strategy that includes an active and experiential feature that facilitates students' autonomy in their health-related learning. However, there is a lack of discussion of whether and how role-play can be used in problem-based learning (PBL). This paper shows the development of a classroom-based innovation using role-play in the PBL class for higher diploma year-one nurse students (a total of 20 students, five per group). This paper consists of five sections: a) the literature on PBL and nurse education, and role-plays as the innovation; b) the PBL case scenario with the illustration of the two role-play scripts, c) student evaluation on role-play in the PBL class; d) discussions on both achievements and limitations of this innovation, and e) the conclusion. It is hoped that this paper will be an example to other nurse educators who are keen on exploring interactive and student-driven learning and teaching strategies in the PBL class. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Target detection and localization in shallow water: an experimental demonstration of the acoustic barrier problem at the laboratory scale.

    Science.gov (United States)

    Marandet, Christian; Roux, Philippe; Nicolas, Barbara; Mars, Jérôme

    2011-01-01

    This study demonstrates experimentally at the laboratory scale the detection and localization of a wavelength-sized target in a shallow ultrasonic waveguide between two source-receiver arrays at 3 MHz. In the framework of the acoustic barrier problem, at the 1/1000 scale, the waveguide represents a 1.1-km-long, 52-m-deep ocean acoustic channel in the kilohertz frequency range. The two coplanar arrays record in the time-domain the transfer matrix of the waveguide between each pair of source-receiver transducers. Invoking the reciprocity principle, a time-domain double-beamforming algorithm is simultaneously performed on the source and receiver arrays. This array processing projects the multireverberated acoustic echoes into an equivalent set of eigenrays, which are defined by their launch and arrival angles. Comparison is made between the intensity of each eigenray without and with a target for detection in the waveguide. Localization is performed through tomography inversion of the acoustic impedance of the target, using all of the eigenrays extracted from double beamforming. The use of the diffraction-based sensitivity kernel for each eigenray provides both the localization and the signature of the target. Experimental results are shown in the presence of surface waves, and methodological issues are discussed for detection and localization.

  3. Improving mathematical problem solving ability through problem-based learning and authentic assessment for the students of Bali State Polytechnic

    Science.gov (United States)

    Darma, I. K.

    2018-01-01

    This research is aimed at determining: 1) the differences of mathematical problem solving ability between the students facilitated with problem-based learning model and conventional learning model, 2) the differences of mathematical problem solving ability between the students facilitated with authentic and conventional assessment model, and 3) interaction effect between learning and assessment model on mathematical problem solving. The research was conducted in Bali State Polytechnic, using the 2x2 experiment factorial design. The samples of this research were 110 students. The data were collected using a theoretically and empirically-validated test. Instruments were validated by using Aiken’s approach of technique content validity and item analysis, and then analyzed using anova stylistic. The result of the analysis shows that the students facilitated with problem-based learning and authentic assessment models get the highest score average compared to the other students, both in the concept understanding and mathematical problem solving. The result of hypothesis test shows that, significantly: 1) there is difference of mathematical problem solving ability between the students facilitated with problem-based learning model and conventional learning model, 2) there is difference of mathematical problem solving ability between the students facilitated with authentic assessment model and conventional assessment model, and 3) there is interaction effect between learning model and assessment model on mathematical problem solving. In order to improve the effectiveness of mathematics learning, collaboration between problem-based learning model and authentic assessment model can be considered as one of learning models in class.

  4. Connotations of pixel-based scale effect in remote sensing and the modified fractal-based analysis method

    Science.gov (United States)

    Feng, Guixiang; Ming, Dongping; Wang, Min; Yang, Jianyu

    2017-06-01

    Scale problems are a major source of concern in the field of remote sensing. Since the remote sensing is a complex technology system, there is a lack of enough cognition on the connotation of scale and scale effect in remote sensing. Thus, this paper first introduces the connotations of pixel-based scale and summarizes the general understanding of pixel-based scale effect. Pixel-based scale effect analysis is essentially important for choosing the appropriate remote sensing data and the proper processing parameters. Fractal dimension is a useful measurement to analysis pixel-based scale. However in traditional fractal dimension calculation, the impact of spatial resolution is not considered, which leads that the scale effect change with spatial resolution can't be clearly reflected. Therefore, this paper proposes to use spatial resolution as the modified scale parameter of two fractal methods to further analyze the pixel-based scale effect. To verify the results of two modified methods (MFBM (Modified Windowed Fractal Brownian Motion Based on the Surface Area) and MDBM (Modified Windowed Double Blanket Method)); the existing scale effect analysis method (information entropy method) is used to evaluate. And six sub-regions of building areas and farmland areas were cut out from QuickBird images to be used as the experimental data. The results of the experiment show that both the fractal dimension and information entropy present the same trend with the decrease of spatial resolution, and some inflection points appear at the same feature scales. Further analysis shows that these feature scales (corresponding to the inflection points) are related to the actual sizes of the geo-object, which results in fewer mixed pixels in the image, and these inflection points are significantly indicative of the observed features. Therefore, the experiment results indicate that the modified fractal methods are effective to reflect the pixel-based scale effect existing in remote sensing

  5. Problem solving strategies used by RN-to-BSN students in an online problem-based learning course.

    Science.gov (United States)

    Oldenburg, Nancy L; Hung, Wei-Chen

    2010-04-01

    It is essential that nursing students develop the problem solving and critical thinking skills required in the current health care environment. Problem-based learning has been promoted as a way to help students acquire those skills; however, gaps exist in the knowledge base of the strategies used by learners. The purpose of this case study was to gain insight into the problem solving experience of a group of six RN-to-BSN students in an online problem-based learning course. Data, including discussion transcripts, reflective papers, and interview transcripts, were analyzed using a qualitative approach. Students expanded their use of resources and resolved the cases, identifying relevant facts and clinical applications. They had difficulty communicating their findings, establishing the credibility of sources, and offering challenging feedback. Increased support and direction are needed to facilitate the development of problem solving abilities of students in the problem-based learning environment.

  6. Application of the heuristically based GPT theory to termohydraulic problems

    International Nuclear Information System (INIS)

    Alvim, A.C.M.

    1988-01-01

    Application of heuristically based generalized perturbation theory (GPT) to the thermohydraulic (generally nonlinear) field is here illustrated. After a short description of the general methodology, the (linear) equations governing the importance function relevant to a generic multichannel problem are derived, within the physical model adopted in the COBRA IV-I Code. These equations are put in a form which should benefit of the calculational scheme of the original COBRA Code in the sense that only minor changes of it (mostly implying physical constants and source terms redefinitions) should be necessary for their solutions. (author) [pt

  7. The Problem of Scale in Indigenous Knowledge: a Perspective from Northern Australia

    Directory of Open Access Journals (Sweden)

    Marc Wohling

    2009-06-01

    Full Text Available Over the last decade, indigenous knowledge has been widely touted by researchers and natural resource managers as a valuable contributor to natural resource management and biodiversity conservation. In Australia, the concept of indigenous knowledge has gained such rapid currency that it has tended toward an essentialized and universal truth rather than remaining a diverse range of highly localized and contested knowledge. In this paper, I undertake a critical analysis of some of the current issues around the interpretation and application of indigenous knowledge and its relationship with natural resource management in northern Australia. Through a focus on how indigenous knowledge operates at a range of scales, I argue that indigenous knowledge is not adapted to the scales and kinds of disturbances that contemporary society is exerting on natural systems. Rather than being realistic about the limitations of indigenous knowledge, I argue that nonindigenous interpretations of indigenous knowledge have propelled us toward reified meanings, abstracted concepts, and an information-based taxonomy of place. The result can be the diminishing and ossifying of a dynamic living practice and the failure to recognize expressions of indigeneity in contemporary forms.

  8. Study on the millimeter-wave scale absorber based on the Salisbury screen

    Science.gov (United States)

    Yuan, Liming; Dai, Fei; Xu, Yonggang; Zhang, Yuan

    2018-03-01

    In order to solve the problem on the millimeter-wave scale absorber, the Salisbury screen absorber is employed and designed based on the RL. By optimizing parameters including the sheet resistance of the surface resistive layer, the permittivity and the thickness of the grounded dielectric layer, the RL of the Salisbury screen absorber could be identical with that of the theoretical scale absorber. An example is given to verify the effectiveness of the method, where the Salisbury screen absorber is designed by the proposed method and compared with the theoretical scale absorber. Meanwhile, plate models and tri-corner reflector (TCR) models are constructed according to the designed result and their scattering properties are simulated by FEKO. Results reveal that the deviation between the designed Salisbury screen absorber and the theoretical scale absorber falls within the tolerance of radar Cross section (RCS) measurement. The work in this paper has important theoretical and practical significance in electromagnetic measurement of large scale ratio.

  9. Modeling and solving a large-scale generation expansion planning problem under uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Shan; Ryan, Sarah M. [Iowa State University, Department of Industrial and Manufacturing Systems Engineering, Ames (United States); Watson, Jean-Paul [Sandia National Laboratories, Discrete Math and Complex Systems Department, Albuquerque (United States); Woodruff, David L. [University of California Davis, Graduate School of Management, Davis (United States)

    2011-11-15

    We formulate a generation expansion planning problem to determine the type and quantity of power plants to be constructed over each year of an extended planning horizon, considering uncertainty regarding future demand and fuel prices. Our model is expressed as a two-stage stochastic mixed-integer program, which we use to compute solutions independently minimizing the expected cost and the Conditional Value-at-Risk; i.e., the risk of significantly larger-than-expected operational costs. We introduce stochastic process models to capture demand and fuel price uncertainty, which are in turn used to generate trees that accurately represent the uncertainty space. Using a realistic problem instance based on the Midwest US, we explore two fundamental, unexplored issues that arise when solving any stochastic generation expansion model. First, we introduce and discuss the use of an algorithm for computing confidence intervals on obtained solution costs, to account for the fact that a finite sample of scenarios was used to obtain a particular solution. Second, we analyze the nature of solutions obtained under different parameterizations of this method, to assess whether the recommended solutions themselves are invariant to changes in costs. The issues are critical for decision makers who seek truly robust recommendations for generation expansion planning. (orig.)

  10. A fuzzy logic based PROMETHEE method for material selection problems

    Directory of Open Access Journals (Sweden)

    Muhammet Gul

    2018-03-01

    Full Text Available Material selection is a complex problem in the design and development of products for diverse engineering applications. This paper presents a fuzzy PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluation method based on trapezoidal fuzzy interval numbers that can be applied to the selection of materials for an automotive instrument panel. Also, it presents uniqueness in making a significant contribution to the literature in terms of the application of fuzzy decision-making approach to material selection problems. The method is illustrated, validated, and compared against three different fuzzy MCDM methods (fuzzy VIKOR, fuzzy TOPSIS, and fuzzy ELECTRE in terms of its ranking performance. Also, the relationships between the compared methods and the proposed scenarios for fuzzy PROMETHEE are evaluated via the Spearman’s correlation coefficient. Styrene Maleic Anhydride and Polypropylene are determined optionally as suitable materials for the automotive instrument panel case. We propose a generic fuzzy MCDM methodology that can be practically implemented to material selection problem. The main advantages of the methodology are consideration of the vagueness, uncertainty, and fuzziness to decision making environment.

  11. Algebraic Reasoning in Solving Mathematical Problem Based on Learning Style

    Science.gov (United States)

    Indraswari, N. F.; Budayasa, I. K.; Ekawati, R.

    2018-01-01

    This study aimed to describe algebraic reasoning of secondary school’s pupils with different learning styles in solving mathematical problem. This study begins by giving the questionnaire to find out the learning styles and followed by mathematical ability test to get three subjects of 8th-grade whereas the learning styles of each pupil is visual, auditory, kinesthetic and had similar mathematical abilities. Then it continued with given algebraic problems and interviews. The data is validated using triangulation of time. The result showed that in the pattern of seeking indicator, subjects identified the things that were known and asked based on them observations. The visual and kinesthetic learners represented the known information in a chart, whereas the auditory learner in a table. In addition, they found the elements which makes the pattern and made a relationship between two quantities. In the pattern recognition indicator, they created conjectures on the relationship between two quantities and proved it. In the generalization indicator, they were determining the general rule of pattern found on each element of pattern using algebraic symbols and created a mathematical model. Visual and kinesthetic learners determined the general rule of equations which was used to solve problems using algebraic symbols, but auditory learner in a sentence.

  12. A Nuclear Scale System Based on LabVIEW

    International Nuclear Information System (INIS)

    Liu Shixing; Gu Qindong

    2009-01-01

    Nuclear mass scales measure the weight of materials which absorb and attenuate the nuclear radiation when the low energy γ-ray through it and is a non-contact continuous measurement device with simple structure and reliable operation. LabVIEW as a graphical programming language is a standard data acquisition and instrument control software. Based on the principle of nuclear mass scale measuring system, monitoring software for nuclear scale system is designed using LabVIEW programming environment. Software architecture mainly composed of three basic modules which include the monitoring software, databases and Web services. It achieves measurement data acquisition, status monitoring, and data management and has networking functions. (authors)

  13. 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.…

  14. Undergraduate medical student's perceptions on traditional and problem based curricula: pilot study.

    Science.gov (United States)

    Meo, Sultan Ayoub

    2014-07-01

    To evaluate and compare students' perceptions about teaching and learning, knowledge and skills, outcomes of course materials and their satisfaction in traditional Lecture Based learning versus Problem-Based Learning curricula in two different medical schools. The comparative cross-sectional questionnaire-based study was conducted in the Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia, from July 2009 to January 2011. Two different undergraduate medical schools were selected; one followed the traditional curriculum, while the other followed the problem-based learning curriculum. Two equal groups of first year medical students were selected. They were taught in respiratory physiology and lung function lab according to their curriculum for a period of two weeks. At the completion of the study period, a five-point Likert scale was used to assess students' perceptions on satisfaction, academic environment, teaching and learning, knowledge and skills and outcomes of course materials about effectiveness of problem-based learning compared to traditional methods. SPSS 19 was used for statistical analysis. Students used to problem-based learning curriculum obtained marginally higher scores in their perceptions (24.10 +/- 3.63) compared to ones following the traditional curriculum (22.67 +/- 3.74). However, the difference in perceptions did not achieve a level of statistical significance. Students following problem-based learning curriculum have more positive perceptions on teaching and learning, knowledge and skills, outcomes of their course materials and satisfaction compared to the students belonging to the traditional style of medical school. However, the difference between the two groups was not statistically significant.

  15. Necessary and Sufficient Conditions for the Existence of Positive Solution for Singular Boundary Value Problems on Time Scales

    Directory of Open Access Journals (Sweden)

    Zhang Xuemei

    2009-01-01

    Full Text Available By constructing available upper and lower solutions and combining the Schauder's fixed point theorem with maximum principle, this paper establishes sufficient and necessary conditions to guarantee the existence of as well as positive solutions for a class of singular boundary value problems on time scales. The results significantly extend and improve many known results for both the continuous case and more general time scales. We illustrate our results by one example.

  16. Problems in cross-cultural use of the hospital anxiety and depression scale: "no butterflies in the desert".

    Science.gov (United States)

    Maters, Gemma A; Sanderman, Robbert; Kim, Aimee Y; Coyne, James C

    2013-01-01

    The Hospital Anxiety and Depression Scale (HADS) is widely used to screen for anxiety and depression. A large literature is citable in support of its validity, but difficulties are increasingly being identified, such as inexplicably discrepant optimal cutpoints and inconsistent factor-structures. This article examines whether these problems could be due to the construction of the HADS that poses difficulties for translation and cross-cultural use. Authors' awareness of difficulties translating the HADS were identified by examining 20% of studies using the HADS, obtained by a systematic literature search in Pubmed and PsycINFO in May 2012. Reports of use of translations and validation studies were recorded for papers from non-English speaking countries. Narrative and systematic reviews were examined for how authors dealt with different translations. Of 417 papers from non-English speaking countries, only 45% indicated whether a translation was used. Studies validating translations were cited in 54%. Seventeen reviews, incorporating data from diverse translated versions, were examined. Only seven mentioned issues of language and culture, and none indicated insurmountable problems in integrating results from different translations. Initial decisions concerning item content and response options likely leave the HADS difficult to translate, but we failed to find an acknowledgment of problems in articles involving its translation and cross-cultural use. Investigators' lack of awareness of these issues can lead to anomalous results and difficulties in interpretation and integration of these results. Reviews tend to overlook these issues and most reviews indiscriminately integrate results from studies performed in different countries. Cross-culturally valid, but literally translated versions of the HADS may not be attainable, and specific cutpoints may not be valid across cultures and language. Claims about rates of anxiety and depression based on integrating cross

  17. Problems in Cross-Cultural Use of the Hospital Anxiety and Depression Scale: “No Butterflies in the Desert”

    Science.gov (United States)

    Maters, Gemma A.; Sanderman, Robbert; Kim, Aimee Y.; Coyne, James C.

    2013-01-01

    Objective The Hospital Anxiety and Depression Scale (HADS) is widely used to screen for anxiety and depression. A large literature is citable in support of its validity, but difficulties are increasingly being identified, such as inexplicably discrepant optimal cutpoints and inconsistent factor-structures. This article examines whether these problems could be due to the construction of the HADS that poses difficulties for translation and cross-cultural use. Methods Authors’ awareness of difficulties translating the HADS were identified by examining 20% of studies using the HADS, obtained by a systematic literature search in Pubmed and PsycINFO in May 2012. Reports of use of translations and validation studies were recorded for papers from non-English speaking countries. Narrative and systematic reviews were examined for how authors dealt with different translations. Results Of 417 papers from non-English speaking countries, only 45% indicated whether a translation was used. Studies validating translations were cited in 54%. Seventeen reviews, incorporating data from diverse translated versions, were examined. Only seven mentioned issues of language and culture, and none indicated insurmountable problems in integrating results from different translations. Conclusion Initial decisions concerning item content and response options likely leave the HADS difficult to translate, but we failed to find an acknowledgment of problems in articles involving its translation and cross-cultural use. Investigators’ lack of awareness of these issues can lead to anomalous results and difficulties in interpretation and integration of these results. Reviews tend to overlook these issues and most reviews indiscriminately integrate results from studies performed in different countries. Cross-culturally valid, but literally translated versions of the HADS may not be attainable, and specific cutpoints may not be valid across cultures and language. Claims about rates of anxiety and

  18. PROBLEM-BASED LEARNING IN THE DIGITAL AGE

    DEFF Research Database (Denmark)

    Kolbæk, Ditte

    Problem-based and project-organized learning (PBL) was originally developed to facilitate collaboration between physically present students; however, due to digitalization, collaboration, dialogues, and other PBL activities should take place online as well. With a theoretical point of departure...... from Dewey and a methodological point of departure from netnography, this study focused on a blended learning module at Aalborg University, where teaching is based on PBL. A primary research question was investigated: “How can IT support collaborative learning among learner communities in a PBL Master......’s program at Aalborg University?” The ways teachers and groups of students could benefit from utilizing IT as a platform for learning were examined. Netnography was the chosen methodology, and the data consisted of the course materials, the reflections, and the dialogues available online. The study showed...

  19. Nursing problem-based learning activity: song writing and singing.

    Science.gov (United States)

    Chan, Zenobia C Y

    2014-08-01

    The function of song is not only to deliver individual's messages, but also to serve as a learning approach to facilitate students' learning. To observe the effectiveness of songs in facilitating students' learning, a Problem-based Learning (PBL) class with twenty students was divided into four groups with five students per group. Each group was asked to write a song based on two given scenarios, to sing the song out loud, and to participate in a follow-up focus group interview afterwards. The four songs reflected the students' understanding of academic knowledge and their perspectives toward the protagonists in the presented scenarios. Two songs are presented in this paper to demonstrate how the approach was carried out in the nursing PBL class. This paper aims to show the implication of song writing and singing in PBL and shed some light on teaching and learning. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Prospect and problems of gas based power stations of NTPC

    International Nuclear Information System (INIS)

    Suryanarayana, A.

    1993-01-01

    The policy of the Government of India concerning utilisation of natural gas resources of the country has undergone changes over the last few years. The government decided in 1985 to allocate natural gas for power generation and in the year 1986 approved the setting up of the first series of three gas based combined cycle power projects of National Thermal Power Corporation (NTPC). The problems of gas power stations of NTPC are discussed. These are high cost of generation, completion of transmission line works to match with the commissioning of gas power stations, high price of natural gas, and fixation of tariff for sale of power from gas based power stations. (N.B.)

  1. Distance learning, problem based learning and dynamic knowledge networks.

    Science.gov (United States)

    Giani, U; Martone, P

    1998-06-01

    This paper is an attempt to develop a distance learning model grounded upon a strict integration of problem based learning (PBL), dynamic knowledge networks (DKN) and web tools, such as hypermedia documents, synchronous and asynchronous communication facilities, etc. The main objective is to develop a theory of distance learning based upon the idea that learning is a highly dynamic cognitive process aimed at connecting different concepts in a network of mutually supporting concepts. Moreover, this process is supposed to be the result of a social interaction that has to be facilitated by the web. The model was tested by creating a virtual classroom of medical and nursing students and activating a learning session on the concept of knowledge representation in health sciences.

  2. Systematizing Scaffolding for Problem-Based Learning: A View from Case-Based Reasoning

    Science.gov (United States)

    Tawfik, Andrew A.; Kolodner, Janet L.

    2016-01-01

    Current theories and models of education often argue that instruction is best administered when knowledge is situated within a context. Problem-based learning (PBL) provides an approach to education that has particularly powerful affordances for learning disciplinary content and practices by solving authentic problems within a discipline. However,…

  3. Robust Face Recognition via Multi-Scale Patch-Based Matrix Regression.

    Directory of Open Access Journals (Sweden)

    Guangwei Gao

    Full Text Available In many real-world applications such as smart card solutions, law enforcement, surveillance and access control, the limited training sample size is the most fundamental problem. By making use of the low-rank structural information of the reconstructed error image, the so-called nuclear norm-based matrix regression has been demonstrated to be effective for robust face recognition with continuous occlusions. However, the recognition performance of nuclear norm-based matrix regression degrades greatly in the face of the small sample size problem. An alternative solution to tackle this problem is performing matrix regression on each patch and then integrating the outputs from all patches. However, it is difficult to set an optimal patch size across different databases. To fully utilize the complementary information from different patch scales for the final decision, we propose a multi-scale patch-based matrix regression scheme based on which the ensemble of multi-scale outputs can be achieved optimally. Extensive experiments on benchmark face databases validate the effectiveness and robustness of our method, which outperforms several state-of-the-art patch-based face recognition algorithms.

  4. Variable choices of scaling in the homogenization of a Nernst-Planck-Poisson problem

    NARCIS (Netherlands)

    Ray, N.; Eck, C.; Muntean, A.; Knabner, P.

    2011-01-01

    We perform the periodic homogenization (i. e. e ¿ 0) of the non-stationary Nernst-Planck-Poisson system using two-scale convergence, where e is a suitable scale parameter. The objective is to investigate the influence of variable choices of scaling in e of the microscopic system of partial

  5. Problem based Learning versus Design Thinking in Team based Project work

    DEFF Research Database (Denmark)

    Denise J. Stokholm, Marianne

    2014-01-01

    project based learning issues, which has caused a need to describe and compare the two models; in specific the understandings, approaches and organization of learning in project work. The PBL model viewing the process as 3 separate project stages including; problem analysis, problem solving and project......All educations at Aalborg University has since 1974 been rooted in Problem Based Learning (PBL). In 1999 a new education in Industrial design was set up, introducing Design Based Learning (DBL). Even though the two approaches have a lot in common they also hold different understandings of core...... report, with focus on problem solving through analysis. Design Based Learning viewing the process as series of integrated design spaces including; alignment, research, mission, vision, concept, product and process report, with focus on innovative ideation though integration. There is a need of renewing...

  6. A fast algorithm for parabolic PDE-based inverse problems based on Laplace transforms and flexible Krylov solvers

    International Nuclear Information System (INIS)

    Bakhos, Tania; Saibaba, Arvind K.; Kitanidis, Peter K.

    2015-01-01

    We consider the problem of estimating parameters in large-scale weakly nonlinear inverse problems for which the underlying governing equations is a linear, time-dependent, parabolic partial differential equation. A major challenge in solving these inverse problems using Newton-type methods is the computational cost associated with solving the forward problem and with repeated construction of the Jacobian, which represents the sensitivity of the measurements to the unknown parameters. Forming the Jacobian can be prohibitively expensive because it requires repeated solutions of the forward and adjoint time-dependent parabolic partial differential equations corresponding to multiple sources and receivers. We propose an efficient method based on a Laplace transform-based exponential time integrator combined with a flexible Krylov subspace approach to solve the resulting shifted systems of equations efficiently. Our proposed solver speeds up the computation of the forward and adjoint problems, thus yielding significant speedup in total inversion time. We consider an application from Transient Hydraulic Tomography (THT), which is an imaging technique to estimate hydraulic parameters related to the subsurface from pressure measurements obtained by a series of pumping tests. The algorithms discussed are applied to a synthetic example taken from THT to demonstrate the resulting computational gains of this proposed method

  7. A fast algorithm for parabolic PDE-based inverse problems based on Laplace transforms and flexible Krylov solvers

    Energy Technology Data Exchange (ETDEWEB)

    Bakhos, Tania, E-mail: taniab@stanford.edu [Institute for Computational and Mathematical Engineering, Stanford University (United States); Saibaba, Arvind K. [Department of Electrical and Computer Engineering, Tufts University (United States); Kitanidis, Peter K. [Institute for Computational and Mathematical Engineering, Stanford University (United States); Department of Civil and Environmental Engineering, Stanford University (United States)

    2015-10-15

    We consider the problem of estimating parameters in large-scale weakly nonlinear inverse problems for which the underlying governing equations is a linear, time-dependent, parabolic partial differential equation. A major challenge in solving these inverse problems using Newton-type methods is the computational cost associated with solving the forward problem and with repeated construction of the Jacobian, which represents the sensitivity of the measurements to the unknown parameters. Forming the Jacobian can be prohibitively expensive because it requires repeated solutions of the forward and adjoint time-dependent parabolic partial differential equations corresponding to multiple sources and receivers. We propose an efficient method based on a Laplace transform-based exponential time integrator combined with a flexible Krylov subspace approach to solve the resulting shifted systems of equations efficiently. Our proposed solver speeds up the computation of the forward and adjoint problems, thus yielding significant speedup in total inversion time. We consider an application from Transient Hydraulic Tomography (THT), which is an imaging technique to estimate hydraulic parameters related to the subsurface from pressure measurements obtained by a series of pumping tests. The algorithms discussed are applied to a synthetic example taken from THT to demonstrate the resulting computational gains of this proposed method.

  8. Hypermedia-Based Problem Based Learning in the Upper Elementary Grades: A Developmental Study.

    Science.gov (United States)

    Brinkerhoff, Jonathan D.; Glazewski, Krista

    This paper describes the application of problem-based learning (PBL) design principles and the inclusion of teacher and study scaffolds to the design and implementation of a hypermedia-based learning unit for the upper elementary/middle school grades. The study examined the following research questions: (1) Does hypermedia-based PBL represent an…

  9. Double inflation: A possible resolution of the large-scale structure problem

    International Nuclear Information System (INIS)

    Turner, M.S.; Villumsen, J.V.; Vittorio, N.; Silk, J.; Juszkiewicz, R.

    1986-11-01

    A model is presented for the large-scale structure of the universe in which two successive inflationary phases resulted in large small-scale and small large-scale density fluctuations. This bimodal density fluctuation spectrum in an Ω = 1 universe dominated by hot dark matter leads to large-scale structure of the galaxy distribution that is consistent with recent observational results. In particular, large, nearly empty voids and significant large-scale peculiar velocity fields are produced over scales of ∼100 Mpc, while the small-scale structure over ≤ 10 Mpc resembles that in a low density universe, as observed. Detailed analytical calculations and numerical simulations are given of the spatial and velocity correlations. 38 refs., 6 figs

  10. SNR enhancement for downhole microseismic data based on scale classification shearlet transform

    Science.gov (United States)

    Li, Juan; Ji, Shuo; Li, Yue; Qian, Zhihong; Lu, Weili

    2018-06-01

    Shearlet transform (ST) can be effective in 2D signal processing, due to its parabolic scaling, high directional sensitivity, and optimal sparsity. ST combined with thresholding has been successfully applied to suppress random noise. However, because of the low magnitude and high frequency of a downhole microseismic signal, the coefficient values of valid signals and noise are similar in the shearlet domain. As a result, it is difficult to use for denoising. In this paper, we present a scale classification ST to solve this problem. The ST is used to decompose noisy microseismic data into serval scales. By analyzing the spectrum and energy distribution of the shearlet coefficients of microseismic data, we divide the scales into two types: low-frequency scales which contain less useful signal and high-frequency scales which contain more useful signal. After classification, we use two different methods to deal with the coefficients on different scales. For the low-frequency scales, the noise is attenuated using a thresholding method. As for the high-frequency scales, we propose to use a generalized Gauss distribution model based a non-local means filter, which takes advantage of the temporal and spatial similarity of microseismic data. The experimental results on both synthetic records and field data illustrate that our proposed method preserves the useful components and attenuates the noise well.

  11. Solving Large-Scale Computational Problems Using Insights from Statistical Physics

    Energy Technology Data Exchange (ETDEWEB)

    Selman, Bart [Cornell University

    2012-02-29

    Many challenging problems in computer science and related fields can be formulated as constraint satisfaction problems. Such problems consist of a set of discrete variables and a set of constraints between those variables, and represent a general class of so-called NP-complete problems. The goal is to find a value assignment to the variables that satisfies all constraints, generally requiring a search through and exponentially large space of variable-value assignments. Models for disordered systems, as studied in statistical physics, can provide important new insights into the nature of constraint satisfaction problems. Recently, work in this area has resulted in the discovery of a new method for solving such problems, called the survey propagation (SP) method. With SP, we can solve problems with millions of variables and constraints, an improvement of two orders of magnitude over previous methods.

  12. Modal-pushover-based ground-motion scaling procedure

    Science.gov (United States)

    Kalkan, Erol; Chopra, Anil K.

    2011-01-01

    Earthquake engineering is increasingly using nonlinear response history analysis (RHA) to demonstrate the performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. This paper presents a modal-pushover-based scaling (MPS) procedure to scale ground motions for use in a nonlinear RHA of buildings. In the MPS method, the ground motions are scaled to match to a specified tolerance, a target value of the inelastic deformation of the first-mode inelastic single-degree-of-freedom (SDF) system whose properties are determined by the first-mode pushover analysis. Appropriate for first-mode dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-mode SDF systems in selecting a subset of the scaled ground motions. Based on results presented for three actual buildings-4, 6, and 13-story-the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

  13. A Multi-Scale Settlement Matching Algorithm Based on ARG

    Science.gov (United States)

    Yue, Han; Zhu, Xinyan; Chen, Di; Liu, Lingjia

    2016-06-01

    Homonymous entity matching is an important part of multi-source spatial data integration, automatic updating and change detection. Considering the low accuracy of existing matching methods in dealing with matching multi-scale settlement data, an algorithm based on Attributed Relational Graph (ARG) is proposed. The algorithm firstly divides two settlement scenes at different scales into blocks by small-scale road network and constructs local ARGs in each block. Then, ascertains candidate sets by merging procedures and obtains the optimal matching pairs by comparing the similarity of ARGs iteratively. Finally, the corresponding relations between settlements at large and small scales are identified. At the end of this article, a demonstration is presented and the results indicate that the proposed algorithm is capable of handling sophisticated cases.

  14. A Multi-Scale Settlement Matching Algorithm Based on ARG

    Directory of Open Access Journals (Sweden)

    H. Yue

    2016-06-01

    Full Text Available Homonymous entity matching is an important part of multi-source spatial data integration, automatic updating and change detection. Considering the low accuracy of existing matching methods in dealing with matching multi-scale settlement data, an algorithm based on Attributed Relational Graph (ARG is proposed. The algorithm firstly divides two settlement scenes at different scales into blocks by small-scale road network and constructs local ARGs in each block. Then, ascertains candidate sets by merging procedures and obtains the optimal matching pairs by comparing the similarity of ARGs iteratively. Finally, the corresponding relations between settlements at large and small scales are identified. At the end of this article, a demonstration is presented and the results indicate that the proposed algorithm is capable of handling sophisticated cases.

  15. Flow Formulation-based Model for the Curriculum-based Course Timetabling Problem

    DEFF Research Database (Denmark)

    Bagger, Niels-Christian Fink; Kristiansen, Simon; Sørensen, Matias

    2015-01-01

    problem. This decreases the number of integer variables signicantly and improves the performance compared to the basic formulation. It also shows competitiveness with other approaches based on mixed integer programming from the literature and improves the currently best known lower bound on one data...... instance in the benchmark data set from the second international timetabling competition.......In this work we will present a new mixed integer programming formulation for the curriculum-based course timetabling problem. We show that the model contains an underlying network model by dividing the problem into two models and then connecting the two models back into one model using a maximum ow...

  16. NDVI, scale invariance and the modifiable areal unit problem : An assessment of vegetation in the Adelaide Parklands

    NARCIS (Netherlands)

    Nouri, Hamideh; Anderson, Sharolyn; Sutton, Paul; Beecham, Simon; Nagler, Pamela; Jarchow, Christopher J.; Roberts, Dar A.

    2017-01-01

    This research addresses the question as to whether or not the Normalised Difference Vegetation Index (NDVI) is scale invariant (i.e. constant over spatial aggregation) for pure pixels of urban vegetation. It has been long recognized that there are issues related to the modifiable areal unit problem

  17. Functional Assessment of School Attendance Problems : An Adapted Version of the School Refusal Assessment Scale-Revised

    NARCIS (Netherlands)

    Heyne, D. A.; Vreeke, L. J.; Maric, M.; Boelens, H.; Van Widenfelt, B. M.

    2017-01-01

    The School Refusal Assessment Scale (SRAS) was developed to identify four factors that might maintain a youth’s school attendance problem (SAP), and thus be targeted for treatment. There is still limited support for the four-factor model inherent to the SRAS and its revision (SRAS-R). Recent studies

  18. Occupational exposure and health problems in small-scale industry workers in Dar es Salaam, Tanzania: a situation analysis.

    NARCIS (Netherlands)

    Rongo, L.M.B.; Barten, F.J.M.H.; Msamanga, G.I.; Heederik, D.; Dolmans, W.M.V.

    2004-01-01

    BACKGROUND: Workers in informal small-scale industries (SSI) in developing countries involved in welding, spray painting, woodwork and metalwork are exposed to various hazards with consequent risk to health. Aim To assess occupational exposure and health problems in SSI in Dar es Salaam, Tanzania.

  19. The effectiveness of problem-based learning on students’ problem solving ability in vector analysis course

    Science.gov (United States)

    Mushlihuddin, R.; Nurafifah; Irvan

    2018-01-01

    The student’s low ability in mathematics problem solving proved to the less effective of a learning process in the classroom. Effective learning was a learning that affects student’s math skills, one of which is problem-solving abilities. Problem-solving capability consisted of several stages: understanding the problem, planning the settlement, solving the problem as planned, re-examining the procedure and the outcome. The purpose of this research was to know: (1) was there any influence of PBL model in improving ability Problem solving of student math in a subject of vector analysis?; (2) was the PBL model effective in improving students’ mathematical problem-solving skills in vector analysis courses? This research was a quasi-experiment research. The data analysis techniques performed from the test stages of data description, a prerequisite test is the normality test, and hypothesis test using the ANCOVA test and Gain test. The results showed that: (1) there was an influence of PBL model in improving students’ math problem-solving abilities in vector analysis courses; (2) the PBL model was effective in improving students’ problem-solving skills in vector analysis courses with a medium category.

  20. Managing the Complexity of Design Problems through Studio-Based Learning

    Science.gov (United States)

    Cennamo, Katherine; Brandt, Carol; Scott, Brigitte; Douglas, Sarah; McGrath, Margarita; Reimer, Yolanda; Vernon, Mitzi

    2011-01-01

    The ill-structured nature of design problems makes them particularly challenging for problem-based learning. Studio-based learning (SBL), however, has much in common with problem-based learning and indeed has a long history of use in teaching students to solve design problems. The purpose of this ethnographic study of an industrial design class,…

  1. Student Development of Information Literacy Skills during Problem-Based Organic Chemistry Laboratory Experiments

    Science.gov (United States)

    Shultz, Ginger V.; Li, Ye

    2016-01-01

    Problem-based learning methods support student learning of content as well as scientific skills. In the course of problem-based learning, students seek outside information related to the problem, and therefore, information literacy skills are practiced when problem-based learning is used. This work describes a mixed-methods approach to investigate…

  2. PBL - Problem Based Learning for Companies and Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Hamburg, I; Vladut, G.

    2016-07-01

    Small and medium sized companies (SMEs) assure economic growth in Europe. Generally many SMEs are struggling to survive in an ongoing global recession and often they are becoming reluctant to release or pay for staff training. In this paper we present shortly the learning methods in SMEs particularly the Problem Based Learning (PBL) as an efficient form for SMEs and entrepreneurship education. In the field of Urban Logistics it was developed four Clusters with potential of innovation and research in four European Regions: Tuscany - Italy, Valencia - Spain, Lisbon and Tagus - Portugal, Oltenia – Romania. Training and mentoring for SMEs, are essential to create competitiveness. Information and communication technologies (ICT) support the tutors by using an ICT platform which is in the development. (Author)

  3. Motivating programming students by Problem Based Learning and LEGO robots

    DEFF Research Database (Denmark)

    Lykke, Marianne; Coto Chotto, Mayela; Mora, Sonia

    2014-01-01

    . For this reason the school is focusing on different teaching methods to help their students master these skills. This paper introduces an experimental, controlled comparison study of three learning designs, involving a problem based learning (PBL) approach in connection with the use of LEGO Mindstorms to improve...... students programming skills and motivation for learning in an introductory programming course. The paper reports the results related with one of the components of the study - the experiential qualities of the three learning designs. The data were collected through a questionnaire survey with 229 students...... from three groups exposed to different learning designs and through six qualitative walk-alongs collecting data from these groups by informal interviews and observations. Findings from the three studies were discussed in three focus group interviews with 10 students from the three experimental groups....

  4. Enabling Problem Based Learning through Web 2.0 Technologies

    DEFF Research Database (Denmark)

    Tambouris, Efthimios; Panopoulou, Eleni; Tarabanis, Konstantinos

    2012-01-01

    of modern educational systems. Established pedagogical strategies, such as Problem Based Learning (PBL), are being adapted for online use in conjunction with modern Web 2.0 technologies and tools. However, even though Web 2.0 and progressive social-networking technologies are automatically associated......Advances in Information and Communications Technology (ICT), particularly the so-called Web 2.0, are affecting all aspects of our life: how we communicate, how we shop, how we socialise, and how we learn. Facilitating learning through the use of ICT, also known as eLearning, is a vital part...... with ideals such as collaboration, sharing, and active learning, it is also possible to use them in a very conservative, teacher-centred way limiting thus their impact. In this paper, we present a PBL 2.0 framework, i.e., a framework combining PBL practices with Web 2.0 technologies. More specifically, we (a...

  5. Scale-invariant entropy-based theory for dynamic ordering

    International Nuclear Information System (INIS)

    Mahulikar, Shripad P.; Kumari, Priti

    2014-01-01

    Dynamically Ordered self-organized dissipative structure exists in various forms and at different scales. This investigation first introduces the concept of an isolated embedding system, which embeds an open system, e.g., dissipative structure and its mass and/or energy exchange with its surroundings. Thereafter, scale-invariant theoretical analysis is presented using thermodynamic principles for Order creation, existence, and destruction. The sustainability criterion for Order existence based on its structured mass and/or energy interactions with the surroundings is mathematically defined. This criterion forms the basis for the interrelationship of physical parameters during sustained existence of dynamic Order. It is shown that the sufficient condition for dynamic Order existence is approached if its sustainability criterion is met, i.e., its destruction path is blocked. This scale-invariant approach has the potential to unify the physical understanding of universal dynamic ordering based on entropy considerations

  6. Web-based Visual Analytics for Extreme Scale Climate Science

    Energy Technology Data Exchange (ETDEWEB)

    Steed, Chad A [ORNL; Evans, Katherine J [ORNL; Harney, John F [ORNL; Jewell, Brian C [ORNL; Shipman, Galen M [ORNL; Smith, Brian E [ORNL; Thornton, Peter E [ORNL; Williams, Dean N. [Lawrence Livermore National Laboratory (LLNL)

    2014-01-01

    In this paper, we introduce a Web-based visual analytics framework for democratizing advanced visualization and analysis capabilities pertinent to large-scale earth system simulations. We address significant limitations of present climate data analysis tools such as tightly coupled dependencies, ineffi- cient data movements, complex user interfaces, and static visualizations. Our Web-based visual analytics framework removes critical barriers to the widespread accessibility and adoption of advanced scientific techniques. Using distributed connections to back-end diagnostics, we minimize data movements and leverage HPC platforms. We also mitigate system dependency issues by employing a RESTful interface. Our framework embraces the visual analytics paradigm via new visual navigation techniques for hierarchical parameter spaces, multi-scale representations, and interactive spatio-temporal data mining methods that retain details. Although generalizable to other science domains, the current work focuses on improving exploratory analysis of large-scale Community Land Model (CLM) and Community Atmosphere Model (CAM) simulations.

  7. Design of a Generic and Flexible Data Structure for Efficient Formulation of Large Scale Network Problems

    DEFF Research Database (Denmark)

    Quaglia, Alberto; Sarup, Bent; Sin, Gürkan

    2013-01-01

    structure for efficient formulation of enterprise-wide optimization problems is presented. Through the integration of the described data structure in our synthesis and design framework, the problem formulation workflow is automated in a software tool, reducing time and resources needed to formulate large......The formulation of Enterprise-Wide Optimization (EWO) problems as mixed integer nonlinear programming requires collecting, consolidating and systematizing large amount of data, coming from different sources and specific to different disciplines. In this manuscript, a generic and flexible data...... problems, while ensuring at the same time data consistency and quality at the application stage....

  8. Large-Scale Constraint-Based Pattern Mining

    Science.gov (United States)

    Zhu, Feida

    2009-01-01

    We studied the problem of constraint-based pattern mining for three different data formats, item-set, sequence and graph, and focused on mining patterns of large sizes. Colossal patterns in each data formats are studied to discover pruning properties that are useful for direct mining of these patterns. For item-set data, we observed robustness of…

  9. Problems in the development of autonomous mobile laser systems based on a cw chemical DF laser

    International Nuclear Information System (INIS)

    Aleksandrov, B P; Bashkin, A S; Beznozdrev, V N; Parfen'ev, M V; Pirogov, N A; Semenov, S N

    2003-01-01

    The problems involved in designing autonomous mobile laser systems based on high-power cw chemical DF lasers, whose mass and size parameters would make it possible to install them on various vehicles, are discussed. The need for mobility of such lasers necessitates special attention to be paid to the quest for ways and means of reducing the mass and size of the main laser systems. The optimisation of the parameters of such lasers is studied for various methods of scaling their systems. A complex approach to analysis of the optical scheme of the laser system is developed. (special issue devoted to the 80th anniversary of academician n g basov's birth)

  10. Analysis of factors affecting satisfaction level on problem based learning approach using structural equation modeling

    Science.gov (United States)

    Hussain, Nur Farahin Mee; Zahid, Zalina

    2014-12-01

    Nowadays, in the job market demand, graduates are expected not only to have higher performance in academic but they must also be excellent in soft skill. Problem-Based Learning (PBL) has a number of distinct advantages as a learning method as it can deliver graduates that will be highly prized by industry. This study attempts to determine the satisfaction level of engineering students on the PBL Approach and to evaluate their determinant factors. The Structural Equation Modeling (SEM) was used to investigate how the factors of Good Teaching Scale, Clear Goals, Student Assessment and Levels of Workload affected the student satisfaction towards PBL approach.

  11. Detangling the Interrelationships between Self- Regulation and Ill-Structured Problem Solving in Problem-Based Learning

    Science.gov (United States)

    Ge, Xun; Law, Victor; Huang, Kun

    2016-01-01

    One of the goals for problem-based learning (PBL) is to promote self-regulation. Although self-regulation has been studied extensively, its interrelationships with ill-structured problem solving have been unclear. In order to clarify the interrelationships, this article proposes a conceptual framework illustrating the iterative processes among…

  12. Problem-Oriented Corporate Knowledge Base Models on the Case-Based Reasoning Approach Basis

    Science.gov (United States)

    Gluhih, I. N.; Akhmadulin, R. K.

    2017-07-01

    One of the urgent directions of efficiency enhancement of production processes and enterprises activities management is creation and use of corporate knowledge bases. The article suggests a concept of problem-oriented corporate knowledge bases (PO CKB), in which knowledge is arranged around possible problem situations and represents a tool for making and implementing decisions in such situations. For knowledge representation in PO CKB a case-based reasoning approach is encouraged to use. Under this approach, the content of a case as a knowledge base component has been defined; based on the situation tree a PO CKB knowledge model has been developed, in which the knowledge about typical situations as well as specific examples of situations and solutions have been represented. A generalized problem-oriented corporate knowledge base structural chart and possible modes of its operation have been suggested. The obtained models allow creating and using corporate knowledge bases for support of decision making and implementing, training, staff skill upgrading and analysis of the decisions taken. The universal interpretation of terms “situation” and “solution” adopted in the work allows using the suggested models to develop problem-oriented corporate knowledge bases in different subject domains. It has been suggested to use the developed models for making corporate knowledge bases of the enterprises that operate engineer systems and networks at large production facilities.

  13. [Problem-based learning, a comparison in the acquisition of transversal competencies].

    Science.gov (United States)

    González Pascual, Juan Luis; López Martin, Inmaculada; Toledo Gómez, David

    2009-01-01

    In the European Higher Education Area (EEES in Spanish reference), a change in the pedagogical model has occurred: from teaching centered on the figure of the professor to learning centered on students, from an integral perspective. This learning must bring together the full set of competencies included in the program requirements necessary to obtain a degree. The specific competencies characterize a profession and distinguish one from others. The transversal competencies surpass the limits of one particular discipline to be potentially developed in all; these are subdivided in three types: instrumental, interpersonal and systemic. The authors describe and compare the acquisition of transversal competencies connected to students' portfolios and Problem-based Learning as pedagogical methods from the perspective of second year nursing students at the European University in Madrid during the 2007-8 academic year To do so, the authors carried out a transversal descriptive study; data was collected by a purpose-made questionnaire the authors developed which they based on the transversal competencies of the Tuning Nursing Project. Variables included age, sex, pedagogical method, perception on acquisition of those 24 competencies by means of a Likert Scale. U de Mann-Whitney descriptive and analytical statistics. The authors conclude that the portfolio and Problem-based Learning are useful pedagogical methods for acquiring transversal competencies; these results coincide with those of other studies. Comparing both methods, the authors share the opinion that the Problem-based Learning method could stimulate the search for information better than the portfolio method.

  14. Development of Internalizing Problems from Adolescence to Emerging Adulthood: Accounting for Heterotypic Continuity with Vertical Scaling

    Science.gov (United States)

    Petersen, Isaac T.; Lindhiem, Oliver; LeBeau, Brandon; Bates, John E.; Pettit, Gregory S.; Lansford, Jennifer E.; Dodge, Kenneth A.

    2018-01-01

    Manifestations of internalizing problems, such as specific symptoms of anxiety and depression, can change across development, even if individuals show strong continuity in rank-order levels of internalizing problems. This illustrates the concept of heterotypic continuity, and raises the question of whether common measures might be construct-valid…

  15. Understanding `green chemistry' and `sustainability': an example of problem-based learning (PBL)

    Science.gov (United States)

    Günter, Tuğçe; Akkuzu, Nalan; Alpat, Şenol

    2017-10-01

    Background: This study uses problem-based learning (PBL) to ensure that students comprehend the significance of green chemistry better by experiencing the stages of identifying the problem, developing hypotheses, and providing solutions within the problem-solving process.

  16. Solving large-scale sparse eigenvalue problems and linear systems of equations for accelerator modeling

    International Nuclear Information System (INIS)

    Gene Golub; Kwok Ko

    2009-01-01

    The solutions of sparse eigenvalue problems and linear systems constitute one of the key computational kernels in the discretization of partial differential equations for the modeling of linear accelerators. The computational challenges faced by existing techniques for solving those sparse eigenvalue problems and linear systems call for continuing research to improve on the algorithms so that ever increasing problem size as required by the physics application can be tackled. Under the support of this award, the filter algorithm for solving large sparse eigenvalue problems was developed at Stanford to address the computational difficulties in the previous methods with the goal to enable accelerator simulations on then the world largest unclassified supercomputer at NERSC for this class of problems. Specifically, a new method, the Hemitian skew-Hemitian splitting method, was proposed and researched as an improved method for solving linear systems with non-Hermitian positive definite and semidefinite matrices.

  17. Detecting Internal Control Problems Based on COSO and Islamic Perspective: Case on SMEs

    Directory of Open Access Journals (Sweden)

    Yuniarti Hidayah Suyoso Putra

    2014-03-01

    Full Text Available Objective – The presence of Small Medium Enterprises (SMEs has been able to be livelihoods sources and absorb more labor, even though it has a relative smaller contribution of additional value compared to the Large-scale Enterprises. The number of economic actors of SMEs spread across area from urban to rural. However, SMEs have faced several serious problems. These problems are caused by the unique characteristics of SMEs itself. First, lack of managerial skills due to limited human resources and lack of monitoring which it is rarely conducted by the manager or the owner. Second, lack of information and technology to carry out operations. Both problems have great impacts in lack of internal controls. Third, SMEs also face problems in developing business scale, limited access to capital to the banks and financial institutions due to the lack of transparency. Therefore, this research aimed to detect to what extent of the problems arising in the application and assessment of internal controls performed by SMEs.Method – The research employs descriptive qualitative research method through direct observation, interview and business documentation owned by the company. Research materials are 29 SMEs consisting of 19 trading SMEs and 10 service SMEs. All SMEs are located in Malang city. Detection of application and assessment of internal controls in this study is based on the COSO framework and the Islamic perspective.Result – Internal control activities indicators apply the five principles of COSO framework which focused on three layers. First layer is self-assessment control area. Second layer is environment control area and the third layer is independent control area. While the Islamic perspective is focused on the internal control of business activities based on the Qur'an and Hadith. The results derive from application and assessment based on COSO framework and Islamic perspectives are complementary in improving the practice of internal

  18. Exploring a Problem-Based Learning Approach in Pharmaceutics

    Directory of Open Access Journals (Sweden)

    Barbara McKenzie

    2017-09-01

    Full Text Available Objective. The basis of this study was to explore the impact of the initiation of a Problem-Base Learning (PBL approach within a second-year pharmaceutics degree on a Master of Pharmacy programme, introduced as a way of improving deep learning and to foster independent learning. Design. A semi-structured interview was used to seek feedback from the students, and feedback from staff was secured though a focus group. A thematic approach was used for the analysis, once data saturation had been reached. Exam pass-rate statistics were also analysed. Assessment. Five parent themes were identified from the student interviews: Module structure, Promoting lifelong learning, Integration and future practice, Outcomes and Student experience. The third year exam pass rate improved by 12% in the year following the introduction of PBL in second year. Conclusions. Various recommendations were proposed to further improve the module, based on the findings of this study. These include improving feedback and support through tutorials, reducing the volume of directed study, as well as highlighting the relevance of pharmaceutics to the pharmacy degree. A long-term review would be needed to assess the full implications of PBL teaching within this course.

  19. Problem-centric Process for Research-based Learning

    Directory of Open Access Journals (Sweden)

    Khaled Shaban

    2015-05-01

    Full Text Available Research-based Learning (RbL extends Inquiry and Project-based Learning by facilitating an early stage exposure and training for future scientists through authentic research activities. In this paper, an iterative problem-centric RbL process is introduced, and its activities and management aspects are described. The process helps implement course-integrated research systematically and practically. Furthermore, the novel process follows constructivist methods in incorporating inquiry, scaffolding, open-ended projects, as well as a goal oriented learning approach. The RbL process is adopted in two advanced computing courses, at two different universities: a leading comprehensive Western university and a new university in a developing country. The paper summarizes new lessons learned in these rewarding experiences. In particular, the instructor should help students start their projects, by providing them with previous work or data and pre-approving the papers to review by students. He should also maintain a continuous feedback to and from students to keep the students motivated and help the instructor refine and adapt the RBL process. We note that research collaborators can help students in identifying the research topics early. The paper also shows how to alleviate difficulties that may be encountered by students who find the novel approach demanding, and consequently it also helps the instructors better manage the course contents.

  20. Maximum length scale in density based topology optimization

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Wang, Fengwen

    2017-01-01

    The focus of this work is on two new techniques for imposing maximum length scale in topology optimization. Restrictions on the maximum length scale provide designers with full control over the optimized structure and open possibilities to tailor the optimized design for broader range...... of manufacturing processes by fulfilling the associated technological constraints. One of the proposed methods is based on combination of several filters and builds on top of the classical density filtering which can be viewed as a low pass filter applied to the design parametrization. The main idea...

  1. Image-based Exploration of Large-Scale Pathline Fields

    KAUST Repository

    Nagoor, Omniah H.

    2014-05-27

    While real-time applications are nowadays routinely used in visualizing large nu- merical simulations and volumes, handling these large-scale datasets requires high-end graphics clusters or supercomputers to process and visualize them. However, not all users have access to powerful clusters. Therefore, it is challenging to come up with a visualization approach that provides insight to large-scale datasets on a single com- puter. Explorable images (EI) is one of the methods that allows users to handle large data on a single workstation. Although it is a view-dependent method, it combines both exploration and modification of visual aspects without re-accessing the original huge data. In this thesis, we propose a novel image-based method that applies the concept of EI in visualizing large flow-field pathlines data. The goal of our work is to provide an optimized image-based method, which scales well with the dataset size. Our approach is based on constructing a per-pixel linked list data structure in which each pixel contains a list of pathlines segments. With this view-dependent method it is possible to filter, color-code and explore large-scale flow data in real-time. In addition, optimization techniques such as early-ray termination and deferred shading are applied, which further improves the performance and scalability of our approach.

  2. Investigating Effects of Problem-Based versus Lecture-Based Learning Environments on Student Motivation

    Science.gov (United States)

    Wijnia, Lisette; Loyens, Sofie M. M.; Derous, Eva

    2011-01-01

    This study examines the effects of two learning environments (i.e., problem-based learning [PBL] versus lecture-based [LB] environments) on undergraduates' study motivation. Survey results demonstrated that PBL students scored higher on competence but did not differ from LB students on autonomous motivation. Analyses of focus groups further…

  3. Rocket to Creativity: A Field Experience in Problem-Based and Project-Based Learning

    Science.gov (United States)

    Dole, Sharon F.; Bloom, Lisa A.; Doss, Kristy Kowalske

    2016-01-01

    This article reports the impact of a field experience in problem-based (PBL) and project-based learning (PjBL) on in-service teachers' conceptions of experiential learning. Participants had been enrolled in a hybrid class that included an online component in which they learned about PBL and PjBL, and an experiential component in which they…

  4. Strategy to identify the causes and to solve a sludge granulation problem in methanogenic reactors: application to a full-scale plant treating cheese wastewater.

    Science.gov (United States)

    Macarie, Hervé; Esquivel, Maricela; Laguna, Acela; Baron, Olivier; El Mamouni, Rachid; Guiot, Serge R; Monroy, Oscar

    2017-08-26

    Granulation of biomass is at the basis of the operation of the most successful anaerobic systems (UASB, EGSB and IC reactors) applied worldwide for wastewater treatment. Despite of decades of studies of the biomass granulation process, it is still not fully understood and controlled. "Degranulation/lack of granulation" is a problem that occurs sometimes in anaerobic systems resulting often in heavy loss of biomass and poor treatment efficiencies or even complete reactor failure. Such a problem occurred in Mexico in two full-scale UASB reactors treating cheese wastewater. A close follow-up of the plant was performed to try to identify the factors responsible for the phenomenon. Basically, the list of possible causes to a granulation problem that were investigated can be classified amongst nutritional, i.e. related to wastewater composition (e.g. deficiency or excess of macronutrients or micronutrients, too high COD proportion due to proteins or volatile fatty acids, high ammonium, sulphate or fat concentrations), operational (excessive loading rate, sub- or over-optimal water upflow velocity) and structural (poor hydraulic design of the plant). Despite of an intensive search, the causes of the granulation problems could not be identified. The present case remains however an example of the strategy that must be followed to identify these causes and could be used as a guide for plant operators or consultants who are confronted with a similar situation independently of the type of wastewater. According to a large literature based on successful experiments at lab scale, an attempt to artificially granulate the industrial reactor biomass through the dosage of a cationic polymer was also tested but equally failed. Instead of promoting granulation, the dosage caused a heavy sludge flotation. This shows that the scaling of such a procedure from lab to real scale cannot be advised right away unless its operability at such a scale can be demonstrated.

  5. Feasibility study of a family- and school-based intervention for child behavior problems in Nepal.

    Science.gov (United States)

    Adhikari, Ramesh P; Upadhaya, Nawaraj; Satinsky, Emily N; Burkey, Matthew D; Kohrt, Brandon A; Jordans, Mark J D

    2018-01-01

    This study evaluates the feasibility, acceptability, and outcomes of a combined school- and family-based intervention, delivered by psychosocial counselors, for children with behavior problems in rural Nepal. Forty-one children participated at baseline. Two students moved to another district, meaning 39 children, ages 6-15, participated at both baseline and follow-up. Pre-post evaluation was used to assess behavioral changes over a 4-month follow-up period (n = 39). The primary outcome measure was the Disruptive Behavior International Scale-Nepal version (DBIS-N). The secondary outcome scales included the Child Functional Impairment Scale and the Eyberg Child Behavior Inventory (ECBI). Twelve key informant interviews were conducted with community stakeholders, including teachers, parents, and community members, to assess stakeholders' perceptions of the intervention. The study found that children's behavior problems as assessed on the DBIS-N were significantly lower at follow-up (M = 13.0, SD = 6.4) than at baseline (M = 20.5, SD = 3.8), p behaviors among children and the implementation of new behavior management techniques both at home and in the classroom. Significant change in child outcome measures in this uncontrolled evaluation, alongside qualitative findings suggesting feasibility and acceptability, support moving toward a controlled trial to determine effectiveness.

  6. Self-Regulation and Problem Solving Ability in 7E-Learning Cycle Based Goal Orientation

    Science.gov (United States)

    Mulyono; Noor, N. L.

    2017-04-01

    Goal orientation differences between mastery goals and performance goals can be a cause of high and low self-regulation and problem-solving abilities. To overcome these problems applied 7E-learning cycle in which students learn and develop ways to optimise the power of reason through the learning phase elicit, engage, explore, explain, elaborate, evaluate, and extend. This study aimed to test the effectiveness of learning by 7E-learning cycle and describe self-regulation and mathematics problem solving based on goal-orientation after the implementation 7E-learning cycle. This study used mix method design with research subject is graders XII sciences MA NU Nurul Ulum Jekulo Kudus which divided into goal orientation is mastery goal and performance goal. The independent variable of this research is learning model, while the dependent variable is problem solving and self-regulation. Then, collecting data using scale, interviews and tests. The data processed with the proportion of test, t-test, paired samples t-test, and Normality-gain. The results show problem-solving abilities of students through 7E-learning cycle the average of mathematical problem-solving capability class, self-regulation at 7E-learning cycle is better than the traditional model study. The problem-solving skills at 7E-learning cycle are better than the traditional model study, there is an increase in self-regulation through 7E-learning cycle of 0.4 (medium), and there is an increased problem-solving ability through 7E-learning cycle by 0.79 (high). Based on the qualitative analysis, self-regulation and problem-solving ability after the implementation of 7E-learning cycle students of a mastery goal group are better than the performance goal team. It is suggested to implement 7E-learning cycle to improve self-regulation and problem-solving ability as well as directing and fostering mastery goal on the student in the learning process.

  7. NDVI, scale invariance and the modifiable areal unit problem: An assessment of vegetation in the Adelaide Parklands.

    Science.gov (United States)

    Nouri, Hamideh; Anderson, Sharolyn; Sutton, Paul; Beecham, Simon; Nagler, Pamela; Jarchow, Christopher J; Roberts, Dar A

    2017-04-15

    This research addresses the question as to whether or not the Normalised Difference Vegetation Index (NDVI) is scale invariant (i.e. constant over spatial aggregation) for pure pixels of urban vegetation. It has been long recognized that there are issues related to the modifiable areal unit problem (MAUP) pertaining to indices such as NDVI and images at varying spatial resolutions. These issues are relevant to using NDVI values in spatial analyses. We compare two different methods of calculation of a mean NDVI: 1) using pixel values of NDVI within feature/object boundaries and 2) first calculating the mean red and mean near-infrared across all feature pixels and then calculating NDVI. We explore the nature and magnitude of these differences for images taken from two sensors, a 1.24m resolution WorldView-3 and a 0.1m resolution digital aerial image. We apply these methods over an urban park located in the Adelaide Parklands of South Australia. We demonstrate that the MAUP is not an issue for calculation of NDVI within a sensor for pure urban vegetation pixels. This may prove useful for future rule-based monitoring of the ecosystem functioning of green infrastructure. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Systematizing Scaffolding for Problem-Based Learning: A View from Case-Based Reasoning

    OpenAIRE

    Tawfik, Andrew A; Kolodner, Janet L

    2016-01-01

    Current theories and models of education often argue that instruction is best administered when knowledge is situated within a context. Problem-based learning (PBL) provides an approach to education that has particularly powerful affordances for learning disciplinary content and practices by solving authentic problems within a discipline. However, not all implementations of PBL have been equally successful at fostering such learning, and some argue that this form of instruction is beyond the ...

  9. Enhancing Students’ Higher Order Thinking Skills through Computer-based Scaffolding in Problem-based Learning

    OpenAIRE

    Kim, Nam Ju

    2017-01-01

    This multiple paper dissertation addressed several issues in Problem-based learning (PBL) through conceptual analysis, meta-analysis, and empirical research. PBL is characterized by ill-structured tasks, self-directed learning process, and a combination of individual and cooperative learning activities. Students who lack content knowledge and problem-solving skills may struggle to address associated tasks that are beyond their current ability levels in PBL. This dissertation addressed a) scaf...

  10. Problems and Projects Based Approach For Analog Electronic Circuits' Course

    Directory of Open Access Journals (Sweden)

    Vahé Nerguizian

    2009-04-01

    Full Text Available New educational methods and approaches are recently introduced and implemented at several North American and European universities using Problems and Projects Based Approach (PPBA. The PPBA employs a teaching technique based mostly on competences/skills rather than only on knowledge. This method has been implemented and proven by several pedagogical instructors and authors at several educational institutions. This approach is used at different disciplines such as medicine, biology, engineering and many others. It has the advantage to improve the student's skills and the knowledge retention rate, and reflects the 21st century industrial/company needs and demands. Before implementing this approach to a course, a good resources preparation and planning is needed upfront by the responsible or instructor of the course to achieve the course and students related objectives. This paper presents the preparation, the generated documentation and the implementation of a pilot project utilizing PPBA education for a second year undergraduate electronic course over a complete semester, and for two different class groups (morning and evening groups. The outcome of this project (achieved goals, observed difficulties and lessons learned is presented based on different tools such as students 'in class' communication and feedback, different course evaluation forms and the professor/instructor feedback. Resources, challenges, difficulties and recommendations are also assessed and presented. The impact, the effect and the results (during and at the end of the academic fall session of the PPBA on students and instructor are discussed, validated, managed and communicated to help other instructor in taking appropriate approach decisions with respect to this new educational approach compared to the classical one.

  11. Formalizing Knowledge in Multi-Scale Agent-Based Simulations.

    Science.gov (United States)

    Somogyi, Endre; Sluka, James P; Glazier, James A

    2016-10-01

    Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused.

  12. Convergence speed of consensus problems over undirected scale-free networks

    International Nuclear Information System (INIS)

    Sun Wei; Dou Li-Hua

    2010-01-01

    Scale-free networks and consensus behaviour among multiple agents have both attracted much attention. To investigate the consensus speed over scale-free networks is the major topic of the present work. A novel method is developed to construct scale-free networks due to their remarkable power-law degree distributions, while preserving the diversity of network topologies. The time cost or iterations for networks to reach a certain level of consensus is discussed, considering the influence from power-law parameters. They are both demonstrated to be reversed power-law functions of the algebraic connectivity, which is viewed as a measurement on convergence speed of the consensus behaviour. The attempts of tuning power-law parameters may speed up the consensus procedure, but it could also make the network less robust over time delay at the same time. Large scale of simulations are supportive to the conclusions. (general)

  13. PROBLEM SOLVING IN SCHOOL MATHEMATICS BASED ON HEURISTIC STRATEGIES

    Directory of Open Access Journals (Sweden)

    NOVOTNÁ, Jarmila

    2014-03-01

    Full Text Available The paper describes one of the ways of developing pupils’ creative approach to problem solving. The described experiment is a part of a longitudinal research focusing on improvement of culture of problem solving by pupils. It deals with solving of problems using the following heuristic strategies: Analogy, Guess – check – revise, Systematic experimentation, Problem reformulation, Solution drawing, Way back and Use of graphs of functions. Most attention is paid to the question whether short-term work, in this case only over the period of three months, can result in improvement of pupils’ abilities to solve problems whose solving algorithms are easily accessible. It also answers the question which strategies pupils will prefer and with what results. The experiment shows that even short-term work can bear positive results as far as pupils’ approach to problem solving is concerned.

  14. Necessary and Sufficient Conditions for the Existence of Positive Solution for Singular Boundary Value Problems on Time Scales

    Directory of Open Access Journals (Sweden)

    Meiqiang Feng

    2009-01-01

    Full Text Available By constructing available upper and lower solutions and combining the Schauder's fixed point theorem with maximum principle, this paper establishes sufficient and necessary conditions to guarantee the existence of Cld[0,1]𝕋 as well as CldΔ[0,1]𝕋 positive solutions for a class of singular boundary value problems on time scales. The results significantly extend and improve many known results for both the continuous case and more general time scales. We illustrate our results by one example.

  15. Perceptual security of encrypted images based on wavelet scaling analysis

    Science.gov (United States)

    Vargas-Olmos, C.; Murguía, J. S.; Ramírez-Torres, M. T.; Mejía Carlos, M.; Rosu, H. C.; González-Aguilar, H.

    2016-08-01

    The scaling behavior of the pixel fluctuations of encrypted images is evaluated by using the detrended fluctuation analysis based on wavelets, a modern technique that has been successfully used recently for a wide range of natural phenomena and technological processes. As encryption algorithms, we use the Advanced Encryption System (AES) in RBT mode and two versions of a cryptosystem based on cellular automata, with the encryption process applied both fully and partially by selecting different bitplanes. In all cases, the results show that the encrypted images in which no understandable information can be visually appreciated and whose pixels look totally random present a persistent scaling behavior with the scaling exponent α close to 0.5, implying no correlation between pixels when the DFA with wavelets is applied. This suggests that the scaling exponents of the encrypted images can be used as a perceptual security criterion in the sense that when their values are close to 0.5 (the white noise value) the encrypted images are more secure also from the perceptual point of view.

  16. Understanding adults’ strong problem-solving skills based on PIAAC

    OpenAIRE

    Hämäläinen, Raija; De Wever, Bram; Nissinen, Kari; Cincinnato, Sebastiano

    2017-01-01

    Purpose Research has shown that the problem-solving skills of adults with a vocational education and training (VET) background in technology-rich environments (TREs) are often inadequate. However, some adults with a VET background do have sound problem-solving skills. The present study aims to provide insight into the socio-demographic, work-related and everyday life factors that are associated with a strong problem-solving performance. Design/methodology/approach The study builds...

  17. The cost of problem-based vs traditional medical education.

    Science.gov (United States)

    Mennin, S P; Martinez-Burrola, N

    1986-05-01

    It is generally accepted that teachers' salaries are a major factor in the cost of medical education. Little is known about the effects of curriculum on teaching time. A comparison of teaching time devoted to each of two different medical education curricula is presented. In a traditional teacher-centered, subject-oriented curriculum, 61% of the total teaching effort expended by twenty-two teachers took place in the absence of students, i.e. in preparation for student contact. Only 39% of the effort devoted by these teachers to medical education took place in the presence of students. In a problem-based, student-centered curriculum which focuses upon small-group tutorial learning and early extended primary care experience in a rural community setting, 72% of the total teaching effort devoted to medical education was spent with students and only 28% was spent in preparation for student contact. Overall, there were no differences in the total amount of teaching time required by each of the two curricular approaches to medical education. There were, however, major differences in how teachers spent their teaching time.

  18. Bringing problem based learning to life using virtual reality.

    Science.gov (United States)

    Nelson, Linda; Sadler, Lynne; Surtees, Geoffrey

    2005-03-01

    Recent UK government policy advocates the need for a more flexible approach to nurse education and ;Fitness for Practice' stresses the importance of information technology and computer mediated learning facilities in the future of nursing education [Department of Health, Making a Difference, Strengthening the Nursing, Midwifery and Health Visiting Contribution to Health Care, Department of Health, 1999; The United Kingdom Central Council For Nursing, Fitness for Practice, The UKCC Commission for Nursing and Midwifery Education, 1999]. In response to this recommendation, a virtual reality package has been designed as a learning resource within adult pre-registration nursing education. This learning and teaching strategy is used in conjunction with problem based learning, enabling students to visualise individual/family life in a community setting. Students are encouraged to consider wider issues such as social and environmental factors and their impact upon health. The virtual reality package acts as one of a number of triggers. This paper will discuss the early development and offer an example of its use as a learning and teaching strategy within year two of a three year programme.

  19. Implementation of problem-based learning in geometry lessons

    Science.gov (United States)

    Ahamad, S. N. S. H.; Li, H.-C.; Shahrill, M.; Prahmana, R. C. I.

    2017-12-01

    The aim of this study is twofold. Firstly, it aims to examine the effects of the Problem-Based Learning (PBL) approach on students’ performance in the learning of geometry. Secondly, it seeks to gain insights from the students regarding the implementation of PBL in geometry lessons. The participants were 22 students from one Year 10 class in a co-educational secondary school in Brunei Darussalam. A mixed method design was employed with data collected from the pre-, post- and retention tests, and interviews. The findings from this study revealed positive influences on students’ performance in learning geometry as gain and retention of knowledge was observed. Meanwhile, mixed responses from the interviews implied that in terms of 1) learning attitudes, students favoured the idea of independent learning but some critiqued that the process of PBL might be time-consuming; 2) learning difficulties, some students struggled in assimilating information leading to poor decision- making; and 3) knowledge and skills, some students believed to have nurtured some skills such as communication and research skills.

  20. Address Translation Problems in IMS Based Next Generation Networks

    Directory of Open Access Journals (Sweden)

    Balazs Godor

    2006-01-01

    Full Text Available The development of packed based multimedia networks reached a turning point when the ITU-T and the ETSIhave incorporated the IMS to the NGN. With the fast development of mobile communication more and more services andcontent are available. In contrast with fix network telephony both the services and the devices are personalized in the “mobileworld”. Services, known from the Internet - like e-mail, chat, browsing, presence, etc. – are already available via mobiledevices as well. The IMS originally wanted to exploit both the benefits of mobile networks and the fancy services of theInternet. But today it is already more than that. IMS is the core of the next generation telecommunication networks and abasis for fix-mobile convergent services. The fact however that IMS was originally a “mobile” standard, where IPv6 was notoddity generated some problems for the fix networks, where IPv4 is used. In this article I give an overview of these problemsand mention some solutions as well.

  1. Route Selection Problem Based on Hopfield Neural Network

    Directory of Open Access Journals (Sweden)

    N. Kojic

    2013-12-01

    Full Text Available Transport network is a key factor of economic, social and every other form of development in the region and the state itself. One of the main conditions for transport network development is the construction of new routes. Often, the construction of regional roads is dominant, since the design and construction in urban areas is quite limited. The process of analysis and planning the new roads is a complex process that depends on many factors (the physical characteristics of the terrain, the economic situation, political decisions, environmental impact, etc. and can take several months. These factors directly or indirectly affect the final solution, and in combination with project limitations and requirements, sometimes can be mutually opposed. In this paper, we present one software solution that aims to find Pareto optimal path for preliminary design of the new roadway. The proposed algorithm is based on many different factors (physical and social with the ability of their increase. This solution is implemented using Hopfield's neural network, as a kind of artificial intelligence, which has shown very good results for solving complex optimization problems.

  2. EFFECT OF PROBLEM BASED LEARNING IN COMPARISION WITH LECTURE BASED LEARNING IN FORENSIC MEDICINE

    Directory of Open Access Journals (Sweden)

    Padmakumar

    2015-09-01

    Full Text Available BACKGROUND: Problem based learning (PBL is an approach to learning and instruction in which students tackle problems in small groups under the supervision of a teacher. This style of learning assumed to foster increased retention of knowledge, improve student’s gene ral problem solving skills, enhance integration of basic science concepts in to clinical problems, foster the development of self - directed learning skills and strengthen student’s intrinsic motivation. AIM: The study was conducted to compare the effect of Problem based learning in comparison with lecture based learning. SETTING: A cross - sectional study was conducted among 2nd year MBBS students of Jubilee Mission Medical College and Research Institute, Thrissur during the period of December 2014 to March 20 15. METHODOLOGY: The batch is divided into two groups (A & B, 45 in each group. By using PBL method, blunt force injuries were taught to Group - A and sharp weapon injuries to group - B. By using lecture based learning (LBL method blunt force injuries were t aught to Group - B and sharp weapon injuries to group - A. At the end of the session a test in the form of MCQ was conducted on the students to evaluate their learning outcome. OBSERVATION AND RESU LTS: In session I, the average test score of LBL group was 8.16 and PBL group was 12. The difference was statistically significant. In session - II also 45 students has participated each in LBL and PBL classes. The average of test score of LBL group was 7.267 and PBL was 11.289, which was highly significant statistical ly . CONCLUSION: Study has proven that problem based learning is an effective teaching learning method when compared to conventional lecture based learning.

  3. Analyzing data from a fuzzy rating scale-based questionnaire. A case study.

    Science.gov (United States)

    Gil, María Ángeles; Lubiano, María Asunción; de la Rosa de Sáa, Sara; Sinova, Beatriz

    2015-01-01

    The fuzzy rating scale was introduced to cope with the imprecision of human thought and experience in measuring attitudes in many fields of Psychology. The flexibility and expressiveness of this scale allow us to properly describe the answers to many questions involving psychological measurement. Analyzing the responses to a fuzzy rating scale-based questionnaire is indeed a critical problem. Nevertheless, over the last years, a methodology is being developed to analyze statistically fuzzy data in such a way that the information they contain is fully exploited. In this paper, a summary review of the main procedures is given. The methods are illustrated by their application on the dataset obtained from a case study with nine-year-old children. In this study, children replied to some questions from the well-known TIMSS/PIRLS questionnaire by using a fuzzy rating scale. The form could be filled in either on the computer or by hand. The study indicates that the requirements of background and training underlying the fuzzy rating scale are not too demanding. Moreover, it is clearly shown that statistical conclusions substantially often differ depending on the responses being given in accordance with either a Likert scale or a fuzzy rating scale.

  4. Developing Environmentally Responsible Behaviours Through the Implementation of Argumentation- and Problem-Based Learning Models

    Science.gov (United States)

    Fettahlıoğlu, Pınar; Aydoğdu, Mustafa

    2018-04-01

    The purpose of this research is to investigate the effect of using argumentation and problem-based learning approaches on the development of environmentally responsible behaviours among pre-service science teachers. Experimental activities were implemented for 14 weeks for 52 class hours in an environmental education class within a science teaching department. A mixed method was used as a research design; particularly, a special type of Concurrent Nested Strategy was applied. The quantitative portion was based on the one-group pre-test and post-test models, and the qualitative portion was based on the holistic multiple-case study method. The quantitative portion of the research was conducted with 34 third-year pre-service science teachers studying at a state university. The qualitative portion of the study was conducted with six pre-service science teachers selected among the 34 pre-service science teachers based on the pre-test results obtained from an environmentally responsible behaviour scale. t tests for dependent groups were used to analyse quantitative data. Both descriptive and content analyses of the qualitative data were performed. The results of the study showed that the use of the argumentation and problem-based learning approaches significantly contributed to the development of environmentally responsible behaviours among pre-service science teachers.

  5. Workload and awkward posture problems among small-scale strawberry farmers in Japan.

    Science.gov (United States)

    Kumudini, Ganga; Hasegawa, Tetsuya

    2009-12-01

    Farmers handle heavy workloads, often in awkward postures and experiencing some work related problems. Farmers perceive them as no more than inevitable consequences of farming activities. Although many problems can be prevented or reduced by simple and inexpensive modifications to work, these problems are increasing among farmers. The main focus of the paper was to investigate workload and awkward postures among strawberry farmers and suggest possible solutions to overcome the identified problems. Questionnaires, direct observations and intertwining methods were used to collect the data. Low-level strawberry beds and long working hours were recognized as critical factors that led to farmers' health problems including suffering from low back pain, heavy fatigue, unsteady feeling after work, etc. There was a substantial increase in fatigue in busy seasons compared with slack seasons. When compared with the other workers such as office, technical, sales and blue-collar workers, female farmers' general fatigue level was considerably high. Findings indicated that strawberry farming was a stressful occupation and farmers were strained under heavy workload, monotonous and repetitive work and poor working conditions with frequent fatigue symptoms and severe influence on health.

  6. Graph-based linear scaling electronic structure theory

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Anders M. N., E-mail: amn@lanl.gov; Negre, Christian F. A.; Cawkwell, Marc J.; Swart, Pieter J.; Germann, Timothy C.; Bock, Nicolas [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mniszewski, Susan M.; Mohd-Yusof, Jamal; Wall, Michael E.; Djidjev, Hristo [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rubensson, Emanuel H. [Division of Scientific Computing, Department of Information Technology, Uppsala University, Box 337, SE-751 05 Uppsala (Sweden)

    2016-06-21

    We show how graph theory can be combined with quantum theory to calculate the electronic structure of large complex systems. The graph formalism is general and applicable to a broad range of electronic structure methods and materials, including challenging systems such as biomolecules. The methodology combines well-controlled accuracy, low computational cost, and natural low-communication parallelism. This combination addresses substantial shortcomings of linear scaling electronic structure theory, in particular with respect to quantum-based molecular dynamics simulations.

  7. IMPACT OF THE PROBLEM-BASED LEARNING CURRICULUM ON ...

    African Journals Online (AJOL)

    (:entred, and to a large extent self-directed. ... 5. Operation learning scale: this scale relates to the reliance on step-by-step logical approach to learning and to the emphasis on factual .... called progressive disclosure method) in order to arrive at a diagnosis ... the students' personality traits more than the mode of learning.

  8. Instructional Design-Based Research on Problem Solving Strategies

    Science.gov (United States)

    Emre-Akdogan, Elçin; Argün, Ziya

    2016-01-01

    The main goal of this study is to find out the effect of the instructional design method on the enhancement of problem solving abilities of students. Teaching sessions were applied to ten students who are in 11th grade, to teach them problem solving strategies which are working backwards, finding pattern, adopting a different point of view,…

  9. Problem based learning: tutors' views 5 years after implementation ...

    African Journals Online (AJOL)

    PBL as an appropriate strategy for achieving skills in problem identification, and problem- solving through team work and appropriate use of resources. The other questions were about tutor involvement in providing administrative feed- back (to student learning). In sum- mary there were five questions about student effects,.

  10. An Energy Based Numerical Approach to Phase Change Problems

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Anders Boe; Damkilde, Lars; Krenk, Steen

    1996-01-01

    Phase change problems, occurring e.g. in melting, casting and freezing processes, are often characterized by a very narrow transition zone with very lareg changes in heat capacity and conductivity. This leads to problems in numerical procedures, where the transition zone propagates through a mesh...

  11. An ontological framework for model-based problem-solving

    NARCIS (Netherlands)

    Scholten, H.; Beulens, A.J.M.

    2012-01-01

    Multidisciplinary projects to solve real world problems of increasing complexity are more and more plagued by obstacles such as miscommunication between modellers with different disciplinary backgrounds and bad modelling practices. To tackle these difficulties, a body of knowledge on problems, on

  12. Logo Programming, Problem Solving, and Knowledge-Based Instruction.

    Science.gov (United States)

    Swan, Karen; Black, John B.

    The research reported in this paper was designed to investigate the hypothesis that computer programming may support the teaching and learning of problem solving, but that to do so, problem solving must be explicitly taught. Three studies involved students in several grades: 4th, 6th, 8th, 11th, and 12th. Findings collectively show that five…

  13. Great Problems of Mathematics: A Course Based on Original Sources.

    Science.gov (United States)

    Laubenbacher, Reinhard C.; Pengelley, David J.

    1992-01-01

    Describes the history of five selected problems from mathematics that are included in an undergraduate honors course designed to utilize original sources for demonstrating the evolution of ideas developed in solving these problems: area and the definite integral, the beginnings of set theory, solutions of algebraic equations, Fermat's last…

  14. A Multi-Stage Reverse Logistics Network Problem by Using Hybrid Priority-Based Genetic Algorithm

    Science.gov (United States)

    Lee, Jeong-Eun; Gen, Mitsuo; Rhee, Kyong-Gu

    Today remanufacturing problem is one of the most important problems regarding to the environmental aspects of the recovery of used products and materials. Therefore, the reverse logistics is gaining become power and great potential for winning consumers in a more competitive context in the future. This paper considers the multi-stage reverse Logistics Network Problem (m-rLNP) while minimizing the total cost, which involves reverse logistics shipping cost and fixed cost of opening the disassembly centers and processing centers. In this study, we first formulate the m-rLNP model as a three-stage logistics network model. Following for solving this problem, we propose a Genetic Algorithm pri (GA) with priority-based encoding method consisting of two stages, and introduce a new crossover operator called Weight Mapping Crossover (WMX). Additionally also a heuristic approach is applied in the 3rd stage to ship of materials from processing center to manufacturer. Finally numerical experiments with various scales of the m-rLNP models demonstrate the effectiveness and efficiency of our approach by comparing with the recent researches.

  15. The difference between problem-oriented education and problem based learning

    DEFF Research Database (Denmark)

    Olsen, Poul Bitsch

    2013-01-01

    Roskilde University offers a distinctive profile and contribution within Denmark. It is well known for its interdisciplinary research and education, including project work and problem-oriented method that is much valued by its students and graduates (International Evaluation Report on Roskilde...

  16. Open Problems in Network-aware Data Management in Exa-scale Computing and Terabit Networking Era

    Energy Technology Data Exchange (ETDEWEB)

    Balman, Mehmet; Byna, Surendra

    2011-12-06

    Accessing and managing large amounts of data is a great challenge in collaborative computing environments where resources and users are geographically distributed. Recent advances in network technology led to next-generation high-performance networks, allowing high-bandwidth connectivity. Efficient use of the network infrastructure is necessary in order to address the increasing data and compute requirements of large-scale applications. We discuss several open problems, evaluate emerging trends, and articulate our perspectives in network-aware data management.

  17. A novel approach based on preference-based index for interval bilevel linear programming problem.

    Science.gov (United States)

    Ren, Aihong; Wang, Yuping; Xue, Xingsi

    2017-01-01

    This paper proposes a new methodology for solving the interval bilevel linear programming problem in which all coefficients of both objective functions and constraints are considered as interval numbers. In order to keep as much uncertainty of the original constraint region as possible, the original problem is first converted into an interval bilevel programming problem with interval coefficients in both objective functions only through normal variation of interval number and chance-constrained programming. With the consideration of different preferences of different decision makers, the concept of the preference level that the interval objective function is preferred to a target interval is defined based on the preference-based index. Then a preference-based deterministic bilevel programming problem is constructed in terms of the preference level and the order relation [Formula: see text]. Furthermore, the concept of a preference δ -optimal solution is given. Subsequently, the constructed deterministic nonlinear bilevel problem is solved with the help of estimation of distribution algorithm. Finally, several numerical examples are provided to demonstrate the effectiveness of the proposed approach.

  18. A novel approach based on preference-based index for interval bilevel linear programming problem

    Directory of Open Access Journals (Sweden)

    Aihong Ren

    2017-05-01

    Full Text Available Abstract This paper proposes a new methodology for solving the interval bilevel linear programming problem in which all coefficients of both objective functions and constraints are considered as interval numbers. In order to keep as much uncertainty of the original constraint region as possible, the original problem is first converted into an interval bilevel programming problem with interval coefficients in both objective functions only through normal variation of interval number and chance-constrained programming. With the consideration of different preferences of different decision makers, the concept of the preference level that the interval objective function is preferred to a target interval is defined based on the preference-based index. Then a preference-based deterministic bilevel programming problem is constructed in terms of the preference level and the order relation ⪯ m w $\\preceq_{mw}$ . Furthermore, the concept of a preference δ-optimal solution is given. Subsequently, the constructed deterministic nonlinear bilevel problem is solved with the help of estimation of distribution algorithm. Finally, several numerical examples are provided to demonstrate the effectiveness of the proposed approach.

  19. The problematic internet entertainment use scale for adolescents: prevalence of problem internet use in Spanish high school students.

    Science.gov (United States)

    Lopez-Fernandez, Olatz; Freixa-Blanxart, Montserrat; Honrubia-Serrano, Maria Luisa

    2013-02-01

    Many researchers and professionals have reported nonsubstance addiction to online entertainments in adolescents. However, very few scales have been designed to assess problem Internet use in this population, in spite of their high exposure and obvious vulnerability. The aim of this study was to review the currently available scales for assessing problematic Internet use and to validate a new scale of this kind for use, specifically in this age group, the Problematic Internet Entertainment Use Scale for Adolescents. The research was carried out in Spain in a gender-balanced sample of 1131 high school students aged between 12 and 18 years. Psychometric analyses showed the scale to be unidimensional, with excellent internal consistency (Cronbach's alpha of 0.92), good construct validity, and positive associations with alternative measures of maladaptive Internet use. This self-administered scale can rapidly measure the presence of symptoms of behavioral addiction to online videogames and social networking sites, as well as their degree of severity. The results estimate the prevalence of this problematic behavior in Spanish adolescents to be around 5 percent.

  20. Does parent-child agreement vary based on presenting problems? Results from a UK clinical sample.

    Science.gov (United States)

    Cleridou, Kalia; Patalay, Praveetha; Martin, Peter

    2017-01-01

    Discrepancies are often found between child and parent reports of child psychopathology, nevertheless the role of the child's presenting difficulties in relation to these is underexplored. This study investigates whether parent-child agreement on the conduct and emotional scales of the Strengths and Difficulties Questionnaire (SDQ) varied as a result of certain child characteristics, including the child's presenting problems to clinical services, age and gender. The UK-based sample consisted of 16,754 clinical records of children aged 11-17, the majority of which were female (57%) and White (76%). The dataset was provided by the Child Outcomes Research Consortium , which collects outcome measures from child services across the UK. Clinicians reported the child's presenting difficulties, and parents and children completed the SDQ. Using correlation analysis, the main findings indicated that agreement varied as a result of the child's difficulties for reports of conduct problems, and this seemed to be related to the presence or absence of externalising difficulties in the child's presentation. This was not the case for reports of emotional difficulties. In addition, agreement was higher when reporting problems not consistent with the child's presentation; for instance, agreement on conduct problems was greater for children presenting with internalising problems. Lastly, the children's age and gender did not seem to have an impact on agreement. These findings demonstrate that certain child presenting difficulties, and in particular conduct problems, may be related to informant agreement and need to be considered in clinical practice and research. Trial Registration This study was observational and as such did not require trial registration.

  1. Effects of a Problem-based Structure of Physics Contents on Conceptual Learning and the Ability to Solve Problems

    Science.gov (United States)

    Becerra-Labra, Carlos; Gras-Martí, Albert; Martínez Torregrosa, Joaquín

    2012-05-01

    A model of teaching/learning is proposed based on a 'problem-based structure' of the contents of the course, in combination with a training in paper and pencil problem solving that emphasizes discussion and quantitative analysis, rather than formulae plug-in. The aim is to reverse the high failure and attrition rate among engineering undergraduates taking physics. A number of tests and questionnaires were administered to a group of students following a traditional lecture-based instruction, as well as to another group that was following an instruction scheme based on the proposed approach and the teaching materials developed ad hoc. The results show that students following the new method can develop scientific reasoning habits in problem-solving skills, and show gains in conceptual learning, attitudes and interests, and that the effects of this approach on learning are noticeable several months after the course is over.

  2. Cooperative Coevolution with Formula-Based Variable Grouping for Large-Scale Global Optimization.

    Science.gov (United States)

    Wang, Yuping; Liu, Haiyan; Wei, Fei; Zong, Tingting; Li, Xiaodong

    2017-08-09

    For a large-scale global optimization (LSGO) problem, divide-and-conquer is usually considered an effective strategy to decompose the problem into smaller subproblems, each of which can then be solved individually. Among these decomposition methods, variable grouping is shown to be promising in recent years. Existing variable grouping methods usually assume the problem to be black-box (i.e., assuming that an analytical model of the objective function is unknown), and they attempt to learn appropriate variable grouping that would allow for a better decomposition of the problem. In such cases, these variable grouping methods do not make a direct use of the formula of the objective function. However, it can be argued that many real-world problems are white-box problems, that is, the formulas of objective functions are often known a priori. These formulas of the objective functions provide rich information which can then be used to design an effective variable group method. In this article, a formula-based grouping strategy (FBG) for white-box problems is first proposed. It groups variables directly via the formula of an objective function which usually consists of a finite number of operations (i.e., four arithmetic operations "[Formula: see text]", "[Formula: see text]", "[Formula: see text]", "[Formula: see text]" and composite operations of basic elementary functions). In FBG, the operations are classified into two classes: one resulting in nonseparable variables, and the other resulting in separable variables. In FBG, variables can be automatically grouped into a suitable number of non-interacting subcomponents, with variables in each subcomponent being interdependent. FBG can easily be applied to any white-box problem and can be integrated into a cooperative coevolution framework. Based on FBG, a novel cooperative coevolution algorithm with formula-based variable grouping (so-called CCF) is proposed in this article for decomposing a large-scale white-box problem

  3. Evaluating the Use of Problem-Based Video Podcasts to Teach Mathematics in Higher Education

    Science.gov (United States)

    Kay, Robin; Kletskin, Ilona

    2012-01-01

    Problem-based video podcasts provide short, web-based, audio-visual explanations of how to solve specific procedural problems in subject areas such as mathematics or science. A series of 59 problem-based video podcasts covering five key areas (operations with functions, solving equations, linear functions, exponential and logarithmic functions,…

  4. [Importance of occupational medicine problem on small and medium scale business enterprises].

    Science.gov (United States)

    Fasikov, R M; Stepanov, E G

    2008-01-01

    First stage of hygienic and psychosocial studies on evaluating the conditions, work specification and health state of small and medium scale business enterprise workers is finished. Findings are that psychosocial factors of work process are highly significant for those workers, and locomotor disorders (backaches) are leaders in morbidity structure among those workers.

  5. The Problem of Scale in the Interpretation of Pictorial Representations of Cell Structure

    Science.gov (United States)

    Vlaardingerbroek, Barend; Taylor, Neil; Bale, Colin

    2014-01-01

    Diagrams feature prominently in science education, and there has been an increase in research focusing on students' use of them in knowledge construction. This paper reports on an investigation into first year university students' perceptions of scale and size at the cellular level. It was found that many students appeared to tacitly assume that…

  6. Small-scale hydropower in the Netherlands : problems and strategies of system builders

    NARCIS (Netherlands)

    Manders, T.N.; Höffken, J.I.; van der Vleuten, E.B.A.

    2016-01-01

    Small-scale hydroelectricity (hydel) currently receives worldwide attention as a clean, green, and socially just energy technology. People generally assume that downsizing hydel plants reduces harmful impacts. However, recent debates call for careful circumspection of small hydel’s environmental,

  7. High scale parity invariance as a solution to the SUSY CP problem ...

    Indian Academy of Sciences (India)

    It is shown that if the supersymmetric Standard Model (MSSM) emerges as the low energy limit of a high scale left–right symmetric gauge structure, the number of uncontrollable CP violating phases of MSSM are drastically reduced. In particular it guarantees the vanishing of the dangerous phases that were at the root of the ...

  8. Modified truncated randomized singular value decomposition (MTRSVD) algorithms for large scale discrete ill-posed problems with general-form regularization

    Science.gov (United States)

    Jia, Zhongxiao; Yang, Yanfei

    2018-05-01

    In this paper, we propose new randomization based algorithms for large scale linear discrete ill-posed problems with general-form regularization: subject to , where L is a regularization matrix. Our algorithms are inspired by the modified truncated singular value decomposition (MTSVD) method, which suits only for small to medium scale problems, and randomized SVD (RSVD) algorithms that generate good low rank approximations to A. We use rank-k truncated randomized SVD (TRSVD) approximations to A by truncating the rank- RSVD approximations to A, where q is an oversampling parameter. The resulting algorithms are called modified TRSVD (MTRSVD) methods. At every step, we use the LSQR algorithm to solve the resulting inner least squares problem, which is proved to become better conditioned as k increases so that LSQR converges faster. We present sharp bounds for the approximation accuracy of the RSVDs and TRSVDs for severely, moderately and mildly ill-posed problems, and substantially improve a known basic bound for TRSVD approximations. We prove how to choose the stopping tolerance for LSQR in order to guarantee that the computed and exact best regularized solutions have the same accuracy. Numerical experiments illustrate that the best regularized solutions by MTRSVD are as accurate as the ones by the truncated generalized singular value decomposition (TGSVD) algorithm, and at least as accurate as those by some existing truncated randomized generalized singular value decomposition (TRGSVD) algorithms. This work was supported in part by the National Science Foundation of China (Nos. 11771249 and 11371219).

  9. Fast and accurate solution for the SCUC problem in large-scale power systems using adapted binary programming and enhanced dual neural network

    International Nuclear Information System (INIS)

    Shafie-khah, M.; Moghaddam, M.P.; Sheikh-El-Eslami, M.K.; Catalão, J.P.S.

    2014-01-01

    Highlights: • A novel hybrid method based on decomposition of SCUC into QP and BP problems is proposed. • An adapted binary programming and an enhanced dual neural network model are applied. • The proposed EDNN is exactly convergent to the global optimal solution of QP. • An AC power flow procedure is developed for including contingency/security issues. • It is suited for large-scale systems, providing both accurate and fast solutions. - Abstract: This paper presents a novel hybrid method for solving the security constrained unit commitment (SCUC) problem. The proposed formulation requires much less computation time in comparison with other methods while assuring the accuracy of the results. Furthermore, the framework provided here allows including an accurate description of warmth-dependent startup costs, valve point effects, multiple fuel costs, forbidden zones of operation, and AC load flow bounds. To solve the nonconvex problem, an adapted binary programming method and enhanced dual neural network model are utilized as optimization tools, and a procedure for AC power flow modeling is developed for including contingency/security issues, as new contributions to earlier studies. Unlike classical SCUC methods, the proposed method allows to simultaneously solve the unit commitment problem and comply with the network limits. In addition to conventional test systems, a real-world large-scale power system with 493 units has been used to fully validate the effectiveness of the novel hybrid method proposed

  10. Towards a Standard-based Domain-specific Platform to Solve Machine Learning-based Problems

    Directory of Open Access Journals (Sweden)

    Vicente García-Díaz

    2015-12-01

    Full Text Available Machine learning is one of the most important subfields of computer science and can be used to solve a variety of interesting artificial intelligence problems. There are different languages, framework and tools to define the data needed to solve machine learning-based problems. However, there is a great number of very diverse alternatives which makes it difficult the intercommunication, portability and re-usability of the definitions, designs or algorithms that any developer may create. In this paper, we take the first step towards a language and a development environment independent of the underlying technologies, allowing developers to design solutions to solve machine learning-based problems in a simple and fast way, automatically generating code for other technologies. That can be considered a transparent bridge among current technologies. We rely on Model-Driven Engineering approach, focusing on the creation of models to abstract the definition of artifacts from the underlying technologies.

  11. Cauchy problem for Laplace equation: An observer based approach

    KAUST Repository

    Majeed, Muhammad Usman

    2013-10-01

    A method to solve Cauchy Problem for Laplace equation using state observers is proposed. It is known that this problem is ill-posed. The domain under consideration is simple lipschitz in 2 with a hole. The idea is to recover the solution over whole domain from the observations on outer boundary. Proposed approach adapts one of the space variables as a time variable. The observer developed to solve Cauchy problem for the Laplace\\'s equation is compuationally robust and accurate. © 2013 IEEE.

  12. Structuring as an Aid to Performance in Base-Rate Problems.

    Science.gov (United States)

    1988-06-01

    effect of different kinds of aids that might help the subjects overcome the base-rate fallacy. One approach that has been tried is to present the subjects...Design. All subjects were given two base-rate problems, here called the Lightbulb problem (adapted from Lyon & Slovic, 1976) and the Dyslexia problem; both...are shown in Table 1. Approximately half the subjects received the Lightbulb problem first; the others received the Dyslexia problem first. The two

  13. QR code based noise-free optical encryption and decryption of a gray scale image

    Science.gov (United States)

    Jiao, Shuming; Zou, Wenbin; Li, Xia

    2017-03-01

    In optical encryption systems, speckle noise is one major challenge in obtaining high quality decrypted images. This problem can be addressed by employing a QR code based noise-free scheme. Previous works have been conducted for optically encrypting a few characters or a short expression employing QR codes. This paper proposes a practical scheme for optically encrypting and decrypting a gray-scale image based on QR codes for the first time. The proposed scheme is compatible with common QR code generators and readers. Numerical simulation results reveal the proposed method can encrypt and decrypt an input image correctly.

  14. Fuzzy Matching Based on Gray-scale Difference for Quantum Images

    Science.gov (United States)

    Luo, GaoFeng; Zhou, Ri-Gui; Liu, XingAo; Hu, WenWen; Luo, Jia

    2018-05-01

    Quantum image processing has recently emerged as an essential problem in practical tasks, e.g. real-time image matching. Previous studies have shown that the superposition and entanglement of quantum can greatly improve the efficiency of complex image processing. In this paper, a fuzzy quantum image matching scheme based on gray-scale difference is proposed to find out the target region in a reference image, which is very similar to the template image. Firstly, we employ the proposed enhanced quantum representation (NEQR) to store digital images. Then some certain quantum operations are used to evaluate the gray-scale difference between two quantum images by thresholding. If all of the obtained gray-scale differences are not greater than the threshold value, it indicates a successful fuzzy matching of quantum images. Theoretical analysis and experiments show that the proposed scheme performs fuzzy matching at a low cost and also enables exponentially significant speedup via quantum parallel computation.

  15. Facilitators' perceptions of problem-based learning and community-based education

    Directory of Open Access Journals (Sweden)

    Annali E Fichardt

    2000-10-01

    Full Text Available In 1997 the School for Nursing, University of the Orange Free State, changed from the traditional lecture method of teaching to problem-based learning and from a curative to a community-based approach. Lecturers from a traditional environment became facilitators and new skills such as listening, dialogue, negotiation, counselling and problemsolving were expected from them. Besides the role change, the environment changed from a structural classroom to an unstructured community. The aim of this research was to determine the perceptions and experiences of facilitators in problem-based learning and community-base education. *Please note: This is a reduced version of the abstract. Please refer to PDF for full text.

  16. Set-Based Discrete Particle Swarm Optimization Based on Decomposition for Permutation-Based Multiobjective Combinatorial Optimization Problems.

    Science.gov (United States)

    Yu, Xue; Chen, Wei-Neng; Gu, Tianlong; Zhang, Huaxiang; Yuan, Huaqiang; Kwong, Sam; Zhang, Jun

    2017-08-07

    This paper studies a specific class of multiobjective combinatorial optimization problems (MOCOPs), namely the permutation-based MOCOPs. Many commonly seen MOCOPs, e.g., multiobjective traveling salesman problem (MOTSP), multiobjective project scheduling problem (MOPSP), belong to this problem class and they can be very different. However, as the permutation-based MOCOPs share the inherent similarity that the structure of their search space is usually in the shape of a permutation tree, this paper proposes a generic multiobjective set-based particle swarm optimization methodology based on decomposition, termed MS-PSO/D. In order to coordinate with the property of permutation-based MOCOPs, MS-PSO/D utilizes an element-based representation and a constructive approach. Through this, feasible solutions under constraints can be generated step by step following the permutation-tree-shaped structure. And problem-related heuristic information is introduced in the constructive approach for efficiency. In order to address the multiobjective optimization issues, the decomposition strategy is employed, in which the problem is converted into multiple single-objective subproblems according to a set of weight vectors. Besides, a flexible mechanism for diversity control is provided in MS-PSO/D. Extensive experiments have been conducted to study MS-PSO/D on two permutation-based MOCOPs, namely the MOTSP and the MOPSP. Experimental results validate that the proposed methodology is promising.

  17. Optimization-based methodology for wastewater treatment plant synthesis – a full scale retrofitting case study

    DEFF Research Database (Denmark)

    Bozkurt, Hande; Gernaey, Krist; Sin, Gürkan

    2015-01-01

    Existing wastewater treatment plants (WWTP) need retrofitting in order to better handle changes in the wastewater flow and composition, reduce operational costs as well as meet newer and stricter regulatory standards on the effluent discharge limits. In this study, we use an optimization based...... technologies. The superstructure optimization problem is formulated as a Mixed Integer (non)Linear Programming problem and solved for different scenarios - represented by different objective functions and constraint definitions. A full-scale domestic wastewater treatment plant (265,000 PE) is used as a case...... framework to manage the multi-criteria WWTP design/retrofit problem for domestic wastewater treatment. The design space (i.e. alternative treatment technologies) is represented in a superstructure, which is coupled with a database containing data for both performance and economics of the novel alternative...

  18. Creative Writing, Problem-Based Learning, and Game-Based Learning Principles

    Science.gov (United States)

    Trekles, Anastasia M.

    2012-01-01

    This paper examines how virtual worlds and other advanced social media can be married with problem-based learning to encourage creativity and critical thinking in the English/Language Arts classroom, particularly for middle school, high school, and undergraduate college education. Virtual world experiences such as "Second Life," Jumpstart.com, and…

  19. Using Problem Based Learning Methods from Engineering Education in Company Based Development

    DEFF Research Database (Denmark)

    Kofoed, Lise B.; Jørgensen, Frances

    2007-01-01

    This paper discusses how Problem-Based Learning (PBL) methods were used to support a Danish company in its efforts to become more of a 'learning organisation', characterized by sharing of knowledge and experiences. One of the central barriers to organisational learning in this company involved...

  20. Introducing problem-based learning (PBL) into a foundation ...

    African Journals Online (AJOL)

    student population has heightened the need for a broader range of teaching and .... The steps involve students encountering a problem, clarifying working definitions ..... of collaboration, poor time management and struggled to process large ...

  1. Cauchy problem for Laplace equation: An observer based approach

    KAUST Repository

    Majeed, Muhammad Usman; Zayane-Aissa, Chadia; Laleg-Kirati, Taous Meriem

    2013-01-01

    domain from the observations on outer boundary. Proposed approach adapts one of the space variables as a time variable. The observer developed to solve Cauchy problem for the Laplace's equation is compuationally robust and accurate. © 2013 IEEE.

  2. Methodological problems in international comparisons based on national surveys

    DEFF Research Database (Denmark)

    Madsen, Henning

    1995-01-01

    Artiklen omhandler de metodemæssige problemer, der opstår, når man gennemfører internationale sammenlignende undersøgelser baseret på nationale forarbejder.......Artiklen omhandler de metodemæssige problemer, der opstår, når man gennemfører internationale sammenlignende undersøgelser baseret på nationale forarbejder....

  3. Lecture-based versus problem-based learning in ethics education among nursing students.

    Science.gov (United States)

    Khatiban, Mahnaz; Falahan, Seyede Nayereh; Amini, Roya; Farahanchi, Afshin; Soltanian, Alireza

    2018-01-01

    Moral reasoning is a vital skill in the nursing profession. Teaching moral reasoning to students is necessary toward promoting nursing ethics. The aim of this study was to compare the effectiveness of problem-based learning and lecture-based methods in ethics education in improving (1) moral decision-making, (2) moral reasoning, (3) moral development, and (4) practical reasoning among nursing students. This is a repeated measurement quasi-experimental study. Participants and research context: The participants were nursing students in a University of Medical Sciences in west of Iran who were randomly assigned to the lecture-based (n = 33) or the problem-based learning (n = 33) groups. The subjects were provided nursing ethics education in four 2-h sessions. The educational content was similar, but the training methods were different. The subjects completed the Nursing Dilemma Test before, immediately after, and 1 month after the training. The data were analyzed and compared using the SPSS-16 software. Ethical considerations: The program was explained to the students, all of whom signed an informed consent form at the baseline. The two groups were similar in personal characteristics (p > 0.05). A significant improvement was observed in the mean scores on moral development in the problem-based learning compared with the lecture-based group (p ethics education enhances moral development among nursing students. However, further studies are needed to determine whether such method improves moral decision-making, moral reasoning, practical considerations, and familiarity with the ethical issues among nursing students.

  4. Towards very large scale laboratory simulation of structure-foundation-soil interaction (SFSI) problems

    OpenAIRE

    Taylor, Colin A.; Crewe, Adam J.; Mylonakis, George

    2016-01-01

    We are at the maturity convergence point of a set of actuation, control, instrumentation and data analysis technologies that make it feasible to construct laboratory experimental rigs that will allow us to address key controlling uncertainties in SFS I assessment and design, which can only be addressed by testing at, or near to, prototype scale. This paper will explore the process of innovation that must be established in order to integrate these enabling technologies and thereby create novel...

  5. Solving and Interpreting Large-scale Harvest Scheduling Problems by Duality and Decomposition

    OpenAIRE

    Berck, Peter; Bible, Thomas

    1982-01-01

    This paper presents a solution to the forest planning problem that takes advantage of both the duality of linear programming formulations currently being used for harvest scheduling and the characteristics of decomposition inherent in the forest land class-relationship. The subproblems of decomposition, defined as the dual, can be solved in a simple, recursive fashion. In effect, such a technique reduces the computational burden in terms of time and computer storage as compared to the traditi...

  6. Improving extreme-scale problem solving: assessing electronic brainstorming effectiveness in an industrial setting.

    Science.gov (United States)

    Dornburg, Courtney C; Stevens, Susan M; Hendrickson, Stacey M L; Davidson, George S

    2009-08-01

    An experiment was conducted to compare the effectiveness of individual versus group electronic brainstorming to address difficult, real-world challenges. Although industrial reliance on electronic communications has become ubiquitous, empirical and theoretical understanding of the bounds of its effectiveness have been limited. Previous research using short-term laboratory experiments have engaged small groups of students in answering questions irrelevant to an industrial setting. The present experiment extends current findings beyond the laboratory to larger groups of real-world employees addressing organization-relevant challenges during the course of 4 days. Employees and contractors at a national laboratory participated, either in a group setting or individually, in an electronic brainstorm to pose solutions to a real-world problem. The data demonstrate that (for this design) individuals perform at least as well as groups in producing quantity of electronic ideas, regardless of brainstorming duration. However, when judged with respect to quality along three dimensions (originality, feasibility, and effectiveness), the individuals significantly (p industrial reliance on electronic problem-solving groups should be tempered, and large nominal groups may be more appropriate corporate problem-solving vehicles.

  7. Berth Allocation Problem with Quay Crane Assignment for Container Terminals Based on Rolling-Horizon Strategy

    Directory of Open Access Journals (Sweden)

    Ling Xiao

    2014-01-01

    Full Text Available In order to solve the large-scale integral dynamic scheduling of continuous berths and quay cranes problem, a method based on rolling-horizon strategy is proposed. A multiobjective optimization model that is established minimizes the total penalty costs considering vessels’ deviations to their preferred berthing positions, delayed times for berthing comparing to their estimated arrival times, and delayed times for departure comparing to their estimated departure times. Then, the scheduling process was divided into a set of continual scheduling interval according to the dynamic arrival sequences. Meanwhile, rolling-horizon strategies for setting rolling and frozen windows and the parameter updating strategy are designed. The input parameters of the model in the next rolling window are updated according to the optimal results of each time window which have been obtained. The model is solved by choosing appropriate rolling and freezing window lengths that represents the numbers of adjacent vessels in the sequence of calling vessels. The holistic optimal solution is obtained by gradually rolling and combining the results of each window. Finally, a case study indicated that the rolling schedule can solve large-scale scheduling problems, and the efficiency of the proposed approach relates to the size of rolling window, freeze ship quantity, and rolling frequency.

  8. COMPARISON OF PROBLEM BASED LEARNING WITH TRADITIONAL LECTURES AMONG FIRST YEAR MEDICAL STUDENTS IN PHYSIOLOGY

    OpenAIRE

    Evelyn

    2015-01-01

    BACKGROUND: Problem based learning has emerged as an effective teaching learning method. Students taught by the problem based learning method have better problem solving skills and better long-term memory than those taught by traditional lectures. OBJECTIVE: To compare the effectiveness of problem based learning with that of traditional lecture method. METHODOLOGY: First MBBS students (n=127) were divided into two groups. One group was taught a topic from Applied Physiolog...

  9. Scales

    Science.gov (United States)

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Examples of disorders that ...

  10. Numerical Problems and Agent-Based Models for a Mass Transfer Course

    Science.gov (United States)

    Murthi, Manohar; Shea, Lonnie D.; Snurr, Randall Q.

    2009-01-01

    Problems requiring numerical solutions of differential equations or the use of agent-based modeling are presented for use in a course on mass transfer. These problems were solved using the popular technical computing language MATLABTM. Students were introduced to MATLAB via a problem with an analytical solution. A more complex problem to which no…

  11. Non-smooth optimization methods for large-scale problems: applications to mid-term power generation planning

    International Nuclear Information System (INIS)

    Emiel, G.

    2008-01-01

    This manuscript deals with large-scale non-smooth optimization that may typically arise when performing Lagrangian relaxation of difficult problems. This technique is commonly used to tackle mixed-integer linear programming - or large-scale convex problems. For example, a classical approach when dealing with power generation planning problems in a stochastic environment is to perform a Lagrangian relaxation of the coupling constraints of demand. In this approach, a master problem coordinates local subproblems, specific to each generation unit. The master problem deals with a separable non-smooth dual function which can be maximized with, for example, bundle algorithms. In chapter 2, we introduce basic tools of non-smooth analysis and some recent results regarding incremental or inexact instances of non-smooth algorithms. However, in some situations, the dual problem may still be very hard to solve. For instance, when the number of dualized constraints is very large (exponential in the dimension of the primal problem), explicit dualization may no longer be possible or the update of dual variables may fail. In order to reduce the dual dimension, different heuristics were proposed. They involve a separation procedure to dynamically select a restricted set of constraints to be dualized along the iterations. This relax-and-cut type approach has shown its numerical efficiency in many combinatorial problems. In chapter 3, we show Primal-dual convergence of such strategy when using an adapted sub-gradient method for the dual step and under minimal assumptions on the separation procedure. Another limit of Lagrangian relaxation may appear when the dual function is separable in highly numerous or complex sub-functions. In such situation, the computational burden of solving all local subproblems may be preponderant in the whole iterative process. A natural strategy would be here to take full advantage of the dual separable structure, performing a dual iteration after having

  12. Coordinated SLNR based Precoding in Large-Scale Heterogeneous Networks

    KAUST Repository

    Boukhedimi, Ikram; Kammoun, Abla; Alouini, Mohamed-Slim

    2017-01-01

    This work focuses on the downlink of large-scale two-tier heterogeneous networks composed of a macro-cell overlaid by micro-cell networks. Our interest is on the design of coordinated beamforming techniques that allow to mitigate the inter-cell interference. Particularly, we consider the case in which the coordinating base stations (BSs) have imperfect knowledge of the channel state information. Under this setting, we propose a regularized SLNR based precoding design in which the regularization factor is used to allow better resilience with respect to the channel estimation errors. Based on tools from random matrix theory, we provide an analytical analysis of the SINR and SLNR performances. These results are then exploited to propose a proper setting of the regularization factor. Simulation results are finally provided in order to validate our findings and to confirm the performance of the proposed precoding scheme.

  13. Coordinated SLNR based Precoding in Large-Scale Heterogeneous Networks

    KAUST Repository

    Boukhedimi, Ikram

    2017-03-06

    This work focuses on the downlink of large-scale two-tier heterogeneous networks composed of a macro-cell overlaid by micro-cell networks. Our interest is on the design of coordinated beamforming techniques that allow to mitigate the inter-cell interference. Particularly, we consider the case in which the coordinating base stations (BSs) have imperfect knowledge of the channel state information. Under this setting, we propose a regularized SLNR based precoding design in which the regularization factor is used to allow better resilience with respect to the channel estimation errors. Based on tools from random matrix theory, we provide an analytical analysis of the SINR and SLNR performances. These results are then exploited to propose a proper setting of the regularization factor. Simulation results are finally provided in order to validate our findings and to confirm the performance of the proposed precoding scheme.

  14. The Social Provisions Scale: psychometric properties of the SPS-10 among participants in nature-based services.

    Science.gov (United States)

    Steigen, Anne Mari; Bergh, Daniel

    2018-02-05

    This article analyses the psychometric properties of the Social Provisions Scale 10-items version. The Social Provisions Scale was analysed by means of the polytomous Rasch model, applied to data on 93 young adults (16-30 years) out of school or work, participating in different nature-based services, due to mental or drug-related problems. The psychometric analysis concludes that the original scale has difficulties related to targeting and construct validity. In order to improve the psychometric properties, the scale was modified to include eight items measuring functional support. The modification was based on theoretical and statistical considerations. After modifications the scale showed not only satisfying psychometric properties, but it also clarified uncertainties regarding construct validity of the measure. However, further analysis on larger samples are required. Implications for Rehabilitation Social support is important for a variety of rehabilitation outcomes and for different patient groups in the rehabilitation context, including people with mental health or drug-related problems. Social Provisions Scale may be used as a screening tool to assess social support of participants in rehabilitation, and the scale may also be an important instrument in rehabilitation research. There might be issues measuring structural support using a 10-items version of the Social Provisions Scale but it seemed to work well as an 8-item scale measuring functional support.

  15. Scale Invariant Gabor Descriptor-Based Noncooperative Iris Recognition

    Directory of Open Access Journals (Sweden)

    Du Yingzi

    2010-01-01

    Full Text Available Abstract A new noncooperative iris recognition method is proposed. In this method, the iris features are extracted using a Gabor descriptor. The feature extraction and comparison are scale, deformation, rotation, and contrast-invariant. It works with off-angle and low-resolution iris images. The Gabor wavelet is incorporated with scale-invariant feature transformation (SIFT for feature extraction to better extract the iris features. Both the phase and magnitude of the Gabor wavelet outputs were used in a novel way for local feature point description. Two feature region maps were designed to locally and globally register the feature points and each subregion in the map is locally adjusted to the dilation/contraction/deformation. We also developed a video-based non-cooperative iris recognition system by integrating video-based non-cooperative segmentation, segmentation evaluation, and score fusion units. The proposed method shows good performance for frontal and off-angle iris matching. Video-based recognition methods can improve non-cooperative iris recognition accuracy.

  16. Scale Invariant Gabor Descriptor-based Noncooperative Iris Recognition

    Directory of Open Access Journals (Sweden)

    Zhi Zhou

    2010-01-01

    Full Text Available A new noncooperative iris recognition method is proposed. In this method, the iris features are extracted using a Gabor descriptor. The feature extraction and comparison are scale, deformation, rotation, and contrast-invariant. It works with off-angle and low-resolution iris images. The Gabor wavelet is incorporated with scale-invariant feature transformation (SIFT for feature extraction to better extract the iris features. Both the phase and magnitude of the Gabor wavelet outputs were used in a novel way for local feature point description. Two feature region maps were designed to locally and globally register the feature points and each subregion in the map is locally adjusted to the dilation/contraction/deformation. We also developed a video-based non-cooperative iris recognition system by integrating video-based non-cooperative segmentation, segmentation evaluation, and score fusion units. The proposed method shows good performance for frontal and off-angle iris matching. Video-based recognition methods can improve non-cooperative iris recognition accuracy.

  17. DIAGNOSIS WINDOWS PROBLEMS BASED ON HYBRID INTELLIGENCE SYSTEMS

    Directory of Open Access Journals (Sweden)

    SAFWAN O. HASOON

    2013-10-01

    Full Text Available This paper describes the artificial intelligence technologies by integrating Radial Basis Function networks with expert systems to construct a robust hybrid system. The purpose of building the hybrid system is to give recommendations to repair the operating system (Windows problems and troubleshoot the problems that can be repaired. The neural network has unique characteristics which it can complete the uncompleted data, the expert system can't deal with data that is incomplete, but using the neural network individually has some disadvantages which it can't give explanations and recommendations to the problems. The expert system has the ability to explain and give recommendations by using the rules and the human expert in some conditions. Therefore, we have combined the two technologies. The paper will explain the integration methods between the two technologies and which method is suitable to be used in the proposed hybrid system.

  18. Scaling of Thermal Images at Different Spatial Resolution: The Mixed Pixel Problem

    Directory of Open Access Journals (Sweden)

    Hamlyn G. Jones

    2014-07-01

    Full Text Available The consequences of changes in spatial resolution for application of thermal imagery in plant phenotyping in the field are discussed. Where image pixels are significantly smaller than the objects of interest (e.g., leaves, accurate estimates of leaf temperature are possible, but when pixels reach the same scale or larger than the objects of interest, the observed temperatures become significantly biased by the background temperature as a result of the presence of mixed pixels. Approaches to the estimation of the true leaf temperature that apply both at the whole-pixel level and at the sub-pixel level are reviewed and discussed.

  19. Gentrification and urban children's well-being: tipping the scales from problems to promise.

    Science.gov (United States)

    Formoso, Diana; N Weber, Rachel; S Atkins, Marc

    2010-12-01

    Gentrification changes the neighborhood and family contexts in which children are socialized-for better and worse-yet little is known about its consequences for youth. This review, drawn from research in urban planning, sociology, and psychology, maps out mechanisms by which gentrification may impact children. We discuss indicators of gentrification and link neighborhood factors, including institutional resources and collective socialization, to family processes more proximally related to child development. Finally, we discuss implications for intervention and public policy recommendations that are intended to tip the scales toward better outcomes for low-income youth in gentrifying areas.

  20. Applications of an implicit HLLC-based Godunov solver for steady state hypersonic problems

    International Nuclear Information System (INIS)

    Link, R.A.; Sharman, B.

    2005-01-01

    Over the past few years, there has been considerable activity developing research vehicles for studying hypersonic propulsion. Successful launches of the Australian Hyshot and the US Hyper-X vehicles have added a significant amount of flight test data to a field that had previously been limited to numerical simulation. A number of approaches have been proposed for hypersonics propulsion, including attached detonation wave, supersonics combustion, and shock induced combustion. Due to the high cost of developing flight hardware, CFD simulations will continue to be a key tool for investigating the feasibility of these concepts. Capturing the interactions of the vehicle body with the boundary layer and chemical reactions pushes the limits of available modelling tools and computer hardware. Explicit formulations are extremely slow in converging to a steady state; therefore, the use of implicit methods are warranted. An implicit LLC-based Godunov solver has been developed at Martec in collaboration with DRDC Valcartier to solve hypersonic problems with a minimum of CPU time and RAM storage. The solver, Chinook Implicit, is based upon the implicit formulation adopted by Batten et. al. The solver is based on a point implicit Gauss-Seidel method for unstructured grids, and includes fully implicit boundary conditions. Preliminary results for small and large scale inviscid hypersonics problems will be presented. (author)

  1. Solving large-scale PDE-constrained Bayesian inverse problems with Riemann manifold Hamiltonian Monte Carlo

    Science.gov (United States)

    Bui-Thanh, T.; Girolami, M.

    2014-11-01

    We consider the Riemann manifold Hamiltonian Monte Carlo (RMHMC) method for solving statistical inverse problems governed by partial differential equations (PDEs). The Bayesian framework is employed to cast the inverse problem into the task of statistical inference whose solution is the posterior distribution in infinite dimensional parameter space conditional upon observation data and Gaussian prior measure. We discretize both the likelihood and the prior using the H1-conforming finite element method together with a matrix transfer technique. The power of the RMHMC method is that it exploits the geometric structure induced by the PDE constraints of the underlying inverse problem. Consequently, each RMHMC posterior sample is almost uncorrelated/independent from the others providing statistically efficient Markov chain simulation. However this statistical efficiency comes at a computational cost. This motivates us to consider computationally more efficient strategies for RMHMC. At the heart of our construction is the fact that for Gaussian error structures the Fisher information matrix coincides with the Gauss-Newton Hessian. We exploit this fact in considering a computationally simplified RMHMC method combining state-of-the-art adjoint techniques and the superiority of the RMHMC method. Specifically, we first form the Gauss-Newton Hessian at the maximum a posteriori point and then use it as a fixed constant metric tensor throughout RMHMC simulation. This eliminates the need for the computationally costly differential geometric Christoffel symbols, which in turn greatly reduces computational effort at a corresponding loss of sampling efficiency. We further reduce the cost of forming the Fisher information matrix by using a low rank approximation via a randomized singular value decomposition technique. This is efficient since a small number of Hessian-vector products are required. The Hessian-vector product in turn requires only two extra PDE solves using the adjoint

  2. Ecology - fundamental bases and way's for decision of problems

    International Nuclear Information System (INIS)

    Kolev, Bogomil Velikov

    2003-01-01

    The metallurgical sciences (material science) are closest to the Geology. Therefore there are close to the ultimate explanation and diagnostics of the natural processes and phenomena in the Earth and in the Universe. They are called upon the other sciences (industries) and society to present the general way's for solution, of the global problems including ecological ones. By solution of these problems always has to be take account of the fact that the Earth is a cosmic body on which surface 'Terrestrial' and 'Space' industries and technologies are developed. (Original)

  3. Reformulating Lead-Based Paint as a Problem in Canada

    Science.gov (United States)

    Perron, Amélie

    2011-01-01

    Leaded gasoline was officially removed from the Canadian market in December 1990. The removal of a major lead source and the subsequent decline in children's blood lead levels marked an important transition point and sparked the emergence of new discourse on lead in Canada. Today, childhood lead poisoning is viewed as a problem of the past or a problem of the United States. Sparse Canadian surveillance data supported this view. Moreover, tensions among federal agencies evolved into a power struggle, with Health Canada ultimately becoming the dominant authority, thereby relegating important research initiatives to obscurity and also shaping a vastly weaker regulatory response to lead than occurred in the United States. PMID:21836119

  4. Mechanistically-Based Field-Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

    International Nuclear Information System (INIS)

    Tim Scheibe; Alexandre Tartakovsky; Brian Wood; Joe Seymour

    2007-01-01

    Effective environmental management of DOE sites requires reliable prediction of reactive transport phenomena. A central issue in prediction of subsurface reactive transport is the impact of multiscale physical, chemical, and biological heterogeneity. Heterogeneity manifests itself through incomplete mixing of reactants at scales below those at which concentrations are explicitly defined (i.e., the numerical grid scale). This results in a mismatch between simulated reaction processes (formulated in terms of average concentrations) and actual processes (controlled by local concentrations). At the field scale, this results in apparent scale-dependence of model parameters and inability to utilize laboratory parameters in field models. Accordingly, most field modeling efforts are restricted to empirical estimation of model parameters by fitting to field observations, which renders extrapolation of model predictions beyond fitted conditions unreliable. The objective of this project is to develop a theoretical and computational framework for (1) connecting models of coupled reactive transport from pore-scale processes to field-scale bioremediation through a hierarchy of models that maintain crucial information from the smaller scales at the larger scales; and (2) quantifying the uncertainty that is introduced by both the upscaling process and uncertainty in physical parameters. One of the challenges of addressing scale-dependent effects of coupled processes in heterogeneous porous media is the problem-specificity of solutions. Much effort has been aimed at developing generalized scaling laws or theories, but these require restrictive assumptions that render them ineffective in many real problems. We propose instead an approach that applies physical and numerical experiments at small scales (specifically the pore scale) to a selected model system in order to identify the scaling approach appropriate to that type of problem. Although the results of such studies will

  5. Mechanistically-Based Field-Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

    Energy Technology Data Exchange (ETDEWEB)

    Tim Scheibe; Alexandre Tartakovsky; Brian Wood; Joe Seymour

    2007-04-19

    Effective environmental management of DOE sites requires reliable prediction of reactive transport phenomena. A central issue in prediction of subsurface reactive transport is the impact of multiscale physical, chemical, and biological heterogeneity. Heterogeneity manifests itself through incomplete mixing of reactants at scales below those at which concentrations are explicitly defined (i.e., the numerical grid scale). This results in a mismatch between simulated reaction processes (formulated in terms of average concentrations) and actual processes (controlled by local concentrations). At the field scale, this results in apparent scale-dependence of model parameters and inability to utilize laboratory parameters in field models. Accordingly, most field modeling efforts are restricted to empirical estimation of model parameters by fitting to field observations, which renders extrapolation of model predictions beyond fitted conditions unreliable. The objective of this project is to develop a theoretical and computational framework for (1) connecting models of coupled reactive transport from pore-scale processes to field-scale bioremediation through a hierarchy of models that maintain crucial information from the smaller scales at the larger scales; and (2) quantifying the uncertainty that is introduced by both the upscaling process and uncertainty in physical parameters. One of the challenges of addressing scale-dependent effects of coupled processes in heterogeneous porous media is the problem-specificity of solutions. Much effort has been aimed at developing generalized scaling laws or theories, but these require restrictive assumptions that render them ineffective in many real problems. We propose instead an approach that applies physical and numerical experiments at small scales (specifically the pore scale) to a selected model system in order to identify the scaling approach appropriate to that type of problem. Although the results of such studies will

  6. FPGA Based Low Power ROM Design Using Capacitance Scaling

    DEFF Research Database (Denmark)

    Bansal, Meenakshi; Bansal, Neha; Saini, Rishita

    2015-01-01

    An ideal capacitor will not dissipate any power, but a real capacitor wil l have some power dissipation. In this work, we are going to design capacitance scaling based low power ROM design. In order to test the compatibility of this ROM design with latest i7 Processor, we are operating this ROM w...... in I/O Power, saving of 0.2% occur in Leakage Power, there will be a saving of 11.54% occur in Total Power. This design is implemented on Virtex-5 FPGA using Xilinx ISE and Verilog....

  7. Crater ejecta scaling laws: fundamental forms based on dimensional analysis

    International Nuclear Information System (INIS)

    Housen, K.R.; Schmidt, R.M.; Holsapple, K.A.

    1983-01-01

    A model of crater ejecta is constructed using dimensional analysis and a recently developed theory of energy and momentum coupling in cratering events. General relations are derived that provide a rationale for scaling laboratory measurements of ejecta to larger events. Specific expressions are presented for ejection velocities and ejecta blanket profiles in two limiting regimes of crater formation: the so-called gravity and strength regimes. In the gravity regime, ejectra velocities at geometrically similar launch points within craters vary as the square root of the product of crater radius and gravity. This relation implies geometric similarity of ejecta blankets. That is, the thickness of an ejecta blanket as a function of distance from the crater center is the same for all sizes of craters if the thickness and range are expressed in terms of crater radii. In the strength regime, ejecta velocities are independent of crater size. Consequently, ejecta blankets are not geometrically similar in this regime. For points away from the crater rim the expressions for ejecta velocities and thickness take the form of power laws. The exponents in these power laws are functions of an exponent, α, that appears in crater radius scaling relations. Thus experimental studies of the dependence of crater radius on impact conditions determine scaling relations for ejecta. Predicted ejection velocities and ejecta-blanket profiles, based on measured values of α, are compared to existing measurements of velocities and debris profiles

  8. Equilibrium and nonequilibrium properties of Boolean decision problems on scale-free graphs with competing interactions with external biases

    Science.gov (United States)

    Zhu, Zheng; Andresen, Juan Carlos; Janzen, Katharina; Katzgraber, Helmut G.

    2013-03-01

    We study the equilibrium and nonequilibrium properties of Boolean decision problems with competing interactions on scale-free graphs in a magnetic field. Previous studies at zero field have shown a remarkable equilibrium stability of Boolean variables (Ising spins) with competing interactions (spin glasses) on scale-free networks. When the exponent that describes the power-law decay of the connectivity of the network is strictly larger than 3, the system undergoes a spin-glass transition. However, when the exponent is equal to or less than 3, the glass phase is stable for all temperatures. First we perform finite-temperature Monte Carlo simulations in a field to test the robustness of the spin-glass phase and show, in agreement with analytical calculations, that the system exhibits a de Almeida-Thouless line. Furthermore, we study avalanches in the system at zero temperature to see if the system displays self-organized criticality. This would suggest that damage (avalanches) can spread across the whole system with nonzero probability, i.e., that Boolean decision problems on scale-free networks with competing interactions are fragile when not in thermal equilibrium.

  9. Boolean decision problems with competing interactions on scale-free networks: Equilibrium and nonequilibrium behavior in an external bias

    Science.gov (United States)

    Zhu, Zheng; Andresen, Juan Carlos; Moore, M. A.; Katzgraber, Helmut G.

    2014-02-01

    We study the equilibrium and nonequilibrium properties of Boolean decision problems with competing interactions on scale-free networks in an external bias (magnetic field). Previous studies at zero field have shown a remarkable equilibrium stability of Boolean variables (Ising spins) with competing interactions (spin glasses) on scale-free networks. When the exponent that describes the power-law decay of the connectivity of the network is strictly larger than 3, the system undergoes a spin-glass transition. However, when the exponent is equal to or less than 3, the glass phase is stable for all temperatures. First, we perform finite-temperature Monte Carlo simulations in a field to test the robustness of the spin-glass phase and show that the system has a spin-glass phase in a field, i.e., exhibits a de Almeida-Thouless line. Furthermore, we study avalanche distributions when the system is driven by a field at zero temperature to test if the system displays self-organized criticality. Numerical results suggest that avalanches (damage) can spread across the whole system with nonzero probability when the decay exponent of the interaction degree is less than or equal to 2, i.e., that Boolean decision problems on scale-free networks with competing interactions can be fragile when not in thermal equilibrium.

  10. Dimensions of Problem Based Learning--Dialogue and Online Collaboration in Projects

    Science.gov (United States)

    Andreasen,, Lars Birch; Nielsen, Jørgen Lerche

    2013-01-01

    The article contributes to the discussions on problem based learning and project work, building on and reflecting the experiences of the authors. Four perspectives are emphasized as central to a contemporary approach to problem- and project-based learning: the exploration of problems, projects as a method, online collaboration, and the dialogic…

  11. Instructional Designers' Media Selection Practices for Distributed Problem-Based Learning Environments

    Science.gov (United States)

    Fells, Stephanie

    2012-01-01

    The design of online or distributed problem-based learning (dPBL) is a nascent, complex design problem. Instructional designers are challenged to effectively unite the constructivist principles of problem-based learning (PBL) with appropriate media in order to create quality dPBL environments. While computer-mediated communication (CMC) tools and…

  12. Knowledge based method for solving complexity in design problems

    NARCIS (Netherlands)

    Vermeulen, B.

    2007-01-01

    The process of design aircraft systems is becoming more and more complex, due to an increasing amount of requirements. Moreover, the knowledge on how to solve these complex design problems becomes less readily available, because of a decrease in availability of intellectual resources and reduced

  13. Achievement of learning outcome after implemented physical modules based on problem based learning

    Science.gov (United States)

    Isna, R.; Masykuri, M.; Sukarmin

    2018-03-01

    Implementation of Problem BasedLearning (PBL) modules can grow the students' thinking skills to solve the problems in daily life and equip the students into higher education levels. The purpose of this research is to know the achievement of learning outcome after implementation physics module based on PBL in Newton,s Law of Gravity. This research method use the experimental method with posttest only group design. To know the achievement of student learning outcomes was analyzed using t test through application of SPSS 18. Based on research result, it is found that the average of student learning outcomes after appliying physics module based on PBL has reached the minimal exhaustiveness criteria. In addition, students' scientific attitudes also improved at each meeting. Presentation activities which contained at learning sync are also able to practice speaking skills and broaden their knowledge. Looking at some shortcomings during the study, it is suggested the issues raised into learning should be a problem close to the life of students so that, the students are more active and enthusiastic in following the learning of physics.

  14. Selecting a scale, the conformal convergence problem and R2 terms

    International Nuclear Information System (INIS)

    Macrae, K.I.

    1981-01-01

    The Einstein-Hilbert action contains negative norm terms such as the conformal factor's kinetic energy. These can be cancelled by the ghosts associated with recoordinatization invariance except when one destroys that invariance by introducing a lattice (cutoff). Regulation of gravitation by a lattice cutoff leads to a funtional integral which does not cenverge on the conformal factor. Convergence of the integral can be insured by introducing a potential depending on the flat background lattice metric, but it can also be achieved by introducing higher order (curvature squared) terms in the action. Such a term together with the usual linear term selects a scale which can be used to single out a special size for the lattice. This ties together renormalization and gravitation in an interesting way. (orig.)

  15. Multi-scale calculation based on dual domain material point method combined with molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Tilak Raj [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-27

    This dissertation combines the dual domain material point method (DDMP) with molecular dynamics (MD) in an attempt to create a multi-scale numerical method to simulate materials undergoing large deformations with high strain rates. In these types of problems, the material is often in a thermodynamically non-equilibrium state, and conventional constitutive relations are often not available. In this method, the closure quantities, such as stress, at each material point are calculated from a MD simulation of a group of atoms surrounding the material point. Rather than restricting the multi-scale simulation in a small spatial region, such as phase interfaces, or crack tips, this multi-scale method can be used to consider non-equilibrium thermodynamic e ects in a macroscopic domain. This method takes advantage that the material points only communicate with mesh nodes, not among themselves; therefore MD simulations for material points can be performed independently in parallel. First, using a one-dimensional shock problem as an example, the numerical properties of the original material point method (MPM), the generalized interpolation material point (GIMP) method, the convected particle domain interpolation (CPDI) method, and the DDMP method are investigated. Among these methods, only the DDMP method converges as the number of particles increases, but the large number of particles needed for convergence makes the method very expensive especially in our multi-scale method where we calculate stress in each material point using MD simulation. To improve DDMP, the sub-point method is introduced in this dissertation, which provides high quality numerical solutions with a very small number of particles. The multi-scale method based on DDMP with sub-points is successfully implemented for a one dimensional problem of shock wave propagation in a cerium crystal. The MD simulation to calculate stress in each material point is performed in GPU using CUDA to accelerate the

  16. How multiagency partnerships can successfully address large-scale pollution problems: a Hawaii case study.

    Science.gov (United States)

    Donohue, Mary J

    2003-06-01

    Oceanic circulation patterns deposit significant amounts of marine pollution, including derelict fishing gear from North Pacific Ocean fisheries, in the Hawaiian Archipelago [Mar. Pollut. Bull. 42(12) (2001) 1301]. Management responsibility for these islands and their associated natural resources is shared by several government authorities. Non-governmental organizations (NGOs) and private industry also have interests in the archipelago. Since the marine debris problem in this region is too large for any single agency to manage, a multiagency marine debris working group (group) was established in 1998 to improve marine debris mitigation in Hawaii. To date, 16 federal, state, and local agencies, working with industry and NGOs, have removed 195 tons of derelict fishing gear from the Northwestern Hawaiian Islands. This review details the evolution of the partnership, notes its challenges and rewards, and advocates its continued use as an effective resource management tool.

  17. Comparison Between Two Methods for Estimating the Vertical Scale of Fluctuation for Modeling Random Geotechnical Problems

    Science.gov (United States)

    Pieczyńska-Kozłowska, Joanna M.

    2015-12-01

    The design process in geotechnical engineering requires the most accurate mapping of soil. The difficulty lies in the spatial variability of soil parameters, which has been a site of investigation of many researches for many years. This study analyses the soil-modeling problem by suggesting two effective methods of acquiring information for modeling that consists of variability from cone penetration test (CPT). The first method has been used in geotechnical engineering, but the second one has not been associated with geotechnics so far. Both methods are applied to a case study in which the parameters of changes are estimated. The knowledge of the variability of parameters allows in a long term more effective estimation, for example, bearing capacity probability of failure.

  18. Solving Man-Induced Large-Scale Conservation Problems: The Spanish Imperial Eagle and Power Lines

    Science.gov (United States)

    López-López, Pascual; Ferrer, Miguel; Madero, Agustín; Casado, Eva; McGrady, Michael

    2011-01-01

    Background Man-induced mortality of birds caused by electrocution with poorly-designed pylons and power lines has been reported to be an important mortality factor that could become a major cause of population decline of one of the world rarest raptors, the Spanish imperial eagle (Aquila adalberti). Consequently it has resulted in an increasing awareness of this problem amongst land managers and the public at large, as well as increased research into the distribution of electrocution events and likely mitigation measures. Methodology/Principal Findings We provide information of how mitigation measures implemented on a regional level under the conservation program of the Spanish imperial eagle have resulted in a positive shift of demographic trends in Spain. A 35 years temporal data set (1974–2009) on mortality of Spanish imperial eagle was recorded, including population censuses, and data on electrocution and non-electrocution of birds. Additional information was obtained from 32 radio-tracked young eagles and specific field surveys. Data were divided into two periods, before and after the approval of a regional regulation of power line design in 1990 which established mandatory rules aimed at minimizing or eliminating the negative impacts of power lines facilities on avian populations. Our results show how population size and the average annual percentage of population change have increased between the two periods, whereas the number of electrocuted birds has been reduced in spite of the continuous growing of the wiring network. Conclusions Our results demonstrate that solving bird electrocution is an affordable problem if political interest is shown and financial investment is made. The combination of an adequate spatial planning with a sustainable development of human infrastructures will contribute positively to the conservation of the Spanish imperial eagle and may underpin population growth and range expansion, with positive side effects on other endangered

  19. A METHOD FOR SOLVING LINEAR PROGRAMMING PROBLEMS WITH FUZZY PARAMETERS BASED ON MULTIOBJECTIVE LINEAR PROGRAMMING TECHNIQUE

    OpenAIRE

    M. ZANGIABADI; H. R. MALEKI

    2007-01-01

    In the real-world optimization problems, coefficients of the objective function are not known precisely and can be interpreted as fuzzy numbers. In this paper we define the concepts of optimality for linear programming problems with fuzzy parameters based on those for multiobjective linear programming problems. Then by using the concept of comparison of fuzzy numbers, we transform a linear programming problem with fuzzy parameters to a multiobjective linear programming problem. To this end, w...

  20. A REGION-BASED MULTI-SCALE APPROACH FOR OBJECT-BASED IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    T. Kavzoglu

    2016-06-01

    Full Text Available Within the last two decades, object-based image analysis (OBIA considering objects (i.e. groups of pixels instead of pixels has gained popularity and attracted increasing interest. The most important stage of the OBIA is image segmentation that groups spectrally similar adjacent pixels considering not only the spectral features but also spatial and textural features. Although there are several parameters (scale, shape, compactness and band weights to be set by the analyst, scale parameter stands out the most important parameter in segmentation process. Estimating optimal scale parameter is crucially important to increase the classification accuracy that depends on image resolution, image object size and characteristics of the study area. In this study, two scale-selection strategies were implemented in the image segmentation process using pan-sharped Qickbird-2 image. The first strategy estimates optimal scale parameters for the eight sub-regions. For this purpose, the local variance/rate of change (LV-RoC graphs produced by the ESP-2 tool were analysed to determine fine, moderate and coarse scales for each region. In the second strategy, the image was segmented using the three candidate scale values (fine, moderate, coarse determined from the LV-RoC graph calculated for whole image. The nearest neighbour classifier was applied in all segmentation experiments and equal number of pixels was randomly selected to calculate accuracy metrics (overall accuracy and kappa coefficient. Comparison of region-based and image-based segmentation was carried out on the classified images and found that region-based multi-scale OBIA produced significantly more accurate results than image-based single-scale OBIA. The difference in classification accuracy reached to 10% in terms of overall accuracy.

  1. Biomedical device prototype based on small scale hydrodynamic cavitation

    Directory of Open Access Journals (Sweden)

    Morteza Ghorbani

    2018-03-01

    Full Text Available This study presents a biomedical device prototype based on small scale hydrodynamic cavitation. The application of small scale hydrodynamic cavitation and its integration to a biomedical device prototype is offered as an important alternative to other techniques, such as ultrasound therapy, and thus constitutes a local, cheap, and energy-efficient solution, for urinary stone therapy and abnormal tissue ablation (e.g., benign prostate hyperplasia (BPH. The destructive nature of bubbly, cavitating, flows was exploited, and the potential of the prototype was assessed and characterized. Bubbles generated in a small flow restrictive element (micro-orifice based on hydrodynamic cavitation were utilized for this purpose. The small bubbly, cavitating, flow generator (micro-orifice was fitted to a small flexible probe, which was actuated with a micromanipulator using fine control. This probe also houses an imaging device for visualization so that the emerging cavitating flow could be locally targeted to the desired spot. In this study, the feasibility of this alternative treatment method and its integration to a device prototype were successfully accomplished.

  2. Biomedical device prototype based on small scale hydrodynamic cavitation

    Science.gov (United States)

    Ghorbani, Morteza; Sozer, Canberk; Alcan, Gokhan; Unel, Mustafa; Ekici, Sinan; Uvet, Huseyin; Koşar, Ali

    2018-03-01

    This study presents a biomedical device prototype based on small scale hydrodynamic cavitation. The application of small scale hydrodynamic cavitation and its integration to a biomedical device prototype is offered as an important alternative to other techniques, such as ultrasound therapy, and thus constitutes a local, cheap, and energy-efficient solution, for urinary stone therapy and abnormal tissue ablation (e.g., benign prostate hyperplasia (BPH)). The destructive nature of bubbly, cavitating, flows was exploited, and the potential of the prototype was assessed and characterized. Bubbles generated in a small flow restrictive element (micro-orifice) based on hydrodynamic cavitation were utilized for this purpose. The small bubbly, cavitating, flow generator (micro-orifice) was fitted to a small flexible probe, which was actuated with a micromanipulator using fine control. This probe also houses an imaging device for visualization so that the emerging cavitating flow could be locally targeted to the desired spot. In this study, the feasibility of this alternative treatment method and its integration to a device prototype were successfully accomplished.

  3. Deep and surface learning in problem-based learning: a review of the literature

    NARCIS (Netherlands)

    D.H.J.M. Dolmans (Diana); S.M.M. Loyens (Sofie); Marcq, H. (Hélène); D. Gijbels (David)

    2016-01-01

    textabstractIn problem-based learning (PBL), implemented worldwide, students learn by discussing professionally relevant problems enhancing application and integration of knowledge, which is assumed to encourage students towards a deep learning approach in which students are intrinsically interested

  4. Deep and surface learning in problem-based learning: a review of the literature

    NARCIS (Netherlands)

    D.H.J.M. Dolmans (Diana); S.M.M. Loyens (Sofie); H. Marcq (Hélène); D. Gijbels (David)

    2015-01-01

    textabstractIn problem-based learning (PBL), implemented worldwide, students learn by discussing professionally relevant problems enhancing application and integration of knowledge, which is assumed to encourage students towards a deep learning approach in which students are intrinsically interested

  5. EFFECTIVENESS OF PROBLEM BASED LEARNING AS A STRATEGY TO FOSTER PROBLEM SOLVING AND CRITICAL REASONING SKILLS AMONG MEDICAL STUDENTS.

    Science.gov (United States)

    Asad, Munazza; Iqbal, Khadija; Sabir, Mohammad

    2015-01-01

    Problem based learning (PBL) is an instructional approach that utilizes problems or cases as a context for students to acquire problem solving skills. It promotes communication skills, active learning, and critical thinking skills. It encourages peer teaching and active participation in a group. It was a cross-sectional study conducted at Al Nafees Medical College, Isra University, Islamabad, in one month duration. This study was conducted on 193 students of both 1st and 2nd year MBBS. Each PBL consists of three sessions, spaced by 2-3 days. In the first session students were provided a PBL case developed by both basic and clinical science faculty. In Session 2 (group discussion), they share, integrate their knowledge with the group and Wrap up (third session), was concluded at the end. A questionnaire based survey was conducted to find out overall effectiveness of PBL sessions. Teaching through PBLs greatly improved the problem solving and critical reasoning skills with 60% students of first year and 71% of 2nd year agreeing that the acquisition of knowledge and its application in solving multiple choice questions (MCQs) was greatly improved by these sessions. They observed that their self-directed learning, intrinsic motivation and skills to relate basic concepts with clinical reasoning which involves higher order thinking have greatly enhanced. Students found PBLs as an effective strategy to promote teamwork and critical thinking skills. PBL is an effective method to improve critical thinking and problem solving skills among medical students.

  6. Model Integrated Problem Solving Based Learning pada Perkuliahan Dasar-dasar Kimia Analitik

    OpenAIRE

    Indarini Dwi Pursitasari; Anna Permanasari

    2013-01-01

    Abstract: Integrated Problem Solving Based Learning Model on Foundation of Analytical Chemistry. This study was conducted to know the effects of Integrated Problem Solving Based Learning (IPSBL) model on problem solving skills and cognitive ability of pre-service teachers. The subjects of the study were 41 pre- service teachers, 21 in the experimental group and 20 in the control group. The data were collected through a test on problem solving skills, a test on cognitive ability, and a questio...

  7. Model Integrated Problem Solving Based Learning Pada Perkuliahan Dasar-dasar Kimia Analitik

    OpenAIRE

    Pursitasari, Indarini Dwi; Permanasari, Anna

    2012-01-01

    : Integrated Problem Solving Based Learning Model on Foundation of Analytical Chemistry. This study was conducted to know the effects of Integrated Problem Solving Based Learning (IPSBL) model on problem solving skills and cognitive ability of pre-service teachers. The subjects of the study were 41 pre- service teachers, 21 in the experimental group and 20 in the control group. The data were collected through a test on problem solving skills, a test on cognitive ability, and a questionnaire o...

  8. Scalable posterior approximations for large-scale Bayesian inverse problems via likelihood-informed parameter and state reduction

    Science.gov (United States)

    Cui, Tiangang; Marzouk, Youssef; Willcox, Karen

    2016-06-01

    Two major bottlenecks to the solution of large-scale Bayesian inverse problems are the scaling of posterior sampling algorithms to high-dimensional parameter spaces and the computational cost of forward model evaluations. Yet incomplete or noisy data, the state variation and parameter dependence of the forward model, and correlations in the prior collectively provide useful structure that can be exploited for dimension reduction in this setting-both in the parameter space of the inverse problem and in the state space of the forward model. To this end, we show how to jointly construct low-dimensional subspaces of the parameter space and the state space in order to accelerate the Bayesian solution of the inverse problem. As a byproduct of state dimension reduction, we also show how to identify low-dimensional subspaces of the data in problems with high-dimensional observations. These subspaces enable approximation of the posterior as a product of two factors: (i) a projection of the posterior onto a low-dimensional parameter subspace, wherein the original likelihood is replaced by an approximation involving a reduced model; and (ii) the marginal prior distribution on the high-dimensional complement of the parameter subspace. We present and compare several strategies for constructing these subspaces using only a limited number of forward and adjoint model simulations. The resulting posterior approximations can rapidly be characterized using standard sampling techniques, e.g., Markov chain Monte Carlo. Two numerical examples demonstrate the accuracy and efficiency of our approach: inversion of an integral equation in atmospheric remote sensing, where the data dimension is very high; and the inference of a heterogeneous transmissivity field in a groundwater system, which involves a partial differential equation forward model with high dimensional state and parameters.

  9. Finite element based composite solution for neutron transport problems

    International Nuclear Information System (INIS)

    Mirza, A.N.; Mirza, N.M.

    1995-01-01

    A finite element treatment for solving neutron transport problems is presented. The employs region-wise discontinuous finite elements for the spatial representation of the neutron angular flux, while spherical harmonics are used for directional dependence. Composite solutions has been obtained by using different orders of angular approximations in different parts of a system. The method has been successfully implemented for one dimensional slab and two dimensional rectangular geometry problems. An overall reduction in the number of nodal coefficients (more than 60% in some cases as compared to conventional schemes) has been achieved without loss of accuracy with better utilization of computational resources. The method also provides an efficient way of handling physically difficult situations such as treatment of voids in duct problems and sharply changing angular flux. It is observed that a great wealth of information about the spatial and directional dependence of the angular flux is obtained much more quickly as compared to Monte Carlo method, where most of the information in restricted to the locality of immediate interest. (author)

  10. Multilevel fast multipole method based on a potential formulation for 3D electromagnetic scattering problems.

    Science.gov (United States)

    Fall, Mandiaye; Boutami, Salim; Glière, Alain; Stout, Brian; Hazart, Jerome

    2013-06-01

    A combination of the multilevel fast multipole method (MLFMM) and boundary element method (BEM) can solve large scale photonics problems of arbitrary geometry. Here, MLFMM-BEM algorithm based on a scalar and vector potential formulation, instead of the more conventional electric and magnetic field formulations, is described. The method can deal with multiple lossy or lossless dielectric objects of arbitrary geometry, be they nested, in contact, or dispersed. Several examples are used to demonstrate that this method is able to efficiently handle 3D photonic scatterers involving large numbers of unknowns. Absorption, scattering, and extinction efficiencies of gold nanoparticle spheres, calculated by the MLFMM, are compared with Mie's theory. MLFMM calculations of the bistatic radar cross section (RCS) of a gold sphere near the plasmon resonance and of a silica coated gold sphere are also compared with Mie theory predictions. Finally, the bistatic RCS of a nanoparticle gold-silver heterodimer calculated with MLFMM is compared with unmodified BEM calculations.

  11. A PSO based Artificial Neural Network approach for short term unit commitment problem

    Directory of Open Access Journals (Sweden)

    AFTAB AHMAD

    2010-10-01

    Full Text Available Unit commitment (UC is a non-linear, large scale, complex, mixed-integer combinatorial constrained optimization problem. This paper proposes, a new hybrid approach for generating unit commitment schedules using swarm intelligence learning rule based neural network. The training data has been generated using dynamic programming for machines without valve point effects and using genetic algorithm for machines with valve point effects. A set of load patterns as inputs and the corresponding unit generation schedules as outputs are used to train the network. The neural network fine tunes the best results to the desired targets. The proposed approach has been validated for three thermal machines with valve point effects and without valve point effects. The results are compared with the approaches available in the literature. The PSO-ANN trained model gives better results which show the promise of the proposed methodology.

  12. [Validation of two brief scales for Internet addiction and mobile phone problem use].

    Science.gov (United States)

    Beranuy Fargues, Marta; Chamarro Lusar, Andrés; Graner Jordania, Carla; Carbonell Sánchez, Xavier

    2009-08-01

    This study describes the construction and validation process of two questionnaires designed to assess the addictive use of Internet and mobile phones. The scales were applied to a sample of 1,879 students. Results support a two-factor model, presenting an acceptable internal consistency and indices of convergent and discriminant validity. The Questionnaire of Experiences Related to Internet was found to assess intra- and interpersonal conflicts related to Internet use. The Questionnaire of Experiences Related to the Mobile Phone was found to assess conflicts related to mobile phone abuse and to maladaptive emotional and communicational patterns. Our results indicate that the mobile phone does not produce the same degree of addictive behavior as Internet; it could rather be interpreted as problematic use. Men displayed more addictive use of Internet, whilst women seemed to use the mobile phone as a means for emotional communication. It seems that the use of both technologies is more problematic during adolescence and normalizes with age toward a more professional and less playful use, and with fewer negative consequences.

  13. Nuclear EMP simulation for large-scale urban environments. FDTD for electrically large problems.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, William S. [Los Alamos National Laboratory; Bull, Jeffrey S. [Los Alamos National Laboratory; Wilcox, Trevor [Los Alamos National Laboratory; Bos, Randall J. [Los Alamos National Laboratory; Shao, Xuan-Min [Los Alamos National Laboratory; Goorley, John T. [Los Alamos National Laboratory; Costigan, Keeley R. [Los Alamos National Laboratory

    2012-08-13

    In case of a terrorist nuclear attack in a metropolitan area, EMP measurement could provide: (1) a prompt confirmation of the nature of the explosion (chemical or nuclear) for emergency response; and (2) and characterization parameters of the device (reaction history, yield) for technical forensics. However, urban environment could affect the fidelity of the prompt EMP measurement (as well as all other types of prompt measurement): (1) Nuclear EMP wavefront would no longer be coherent, due to incoherent production, attenuation, and propagation of gamma and electrons; and (2) EMP propagation from source region outward would undergo complicated transmission, reflection, and diffraction processes. EMP simulation for electrically-large urban environment: (1) Coupled MCNP/FDTD (Finite-difference time domain Maxwell solver) approach; and (2) FDTD tends to be limited to problems that are not 'too' large compared to the wavelengths of interest because of numerical dispersion and anisotropy. We use a higher-order low-dispersion, isotropic FDTD algorithm for EMP propagation.

  14. EP BASED PSO METHOD FOR SOLVING PROFIT BASED MULTI AREA UNIT COMMITMENT PROBLEM

    Directory of Open Access Journals (Sweden)

    K. VENKATESAN

    2015-04-01

    Full Text Available This paper presents a new approach to solve the profit based multi area unit commitment problem (PBMAUCP using an evolutionary programming based particle swarm optimization (EPPSO method. The objective of this paper is to maximize the profit of generation companies (GENCOs with considering system social benefit. The proposed method helps GENCOs to make a decision, how much power and reserve should be sold in markets, and how to schedule generators in order to receive the maximum profit. Joint operation of generation resources can result in significant operational cost savings. Power transfer between the areas through the tie lines depends upon the operating cost of generation at each hour and tie line transfer limits. The tie line transfer limits were considered as a set of constraints during optimization process to ensure the system security and reliability. The overall algorithm can be implemented on an IBM PC, which can process a fairly large system in a reasonable period of time. Case study of four areas with different load pattern each containing 7 units (NTPS and 26 units connected via tie lines have been taken for analysis. Numerical results showed comparing the profit of evolutionary programming-based particle swarm optimization method (EPPSO with conventional dynamic programming (DP, evolutionary programming (EP, and particle swarm optimization (PSO method. Experimental results shows that the application of this evolutionary programming based particle swarm optimization method have the potential to solve profit based multi area unit commitment problem with lesser computation time.

  15. Subspace-based analysis of the ERT inverse problem

    Science.gov (United States)

    Ben Hadj Miled, Mohamed Khames; Miller, Eric L.

    2004-05-01

    In a previous work, we proposed a source-type formulation to the electrical resistance tomography (ERT) problem. Specifically, we showed that inhomogeneities in the medium can be viewed as secondary sources embedded in the homogeneous background medium and located at positions associated with variation in electrical conductivity. Assuming a piecewise constant conductivity distribution, the support of equivalent sources is equal to the boundary of the inhomogeneity. The estimation of the anomaly shape takes the form of an inverse source-type problem. In this paper, we explore the use of subspace methods to localize the secondary equivalent sources associated with discontinuities in the conductivity distribution. Our first alternative is the multiple signal classification (MUSIC) algorithm which is commonly used in the localization of multiple sources. The idea is to project a finite collection of plausible pole (or dipole) sources onto an estimated signal subspace and select those with largest correlations. In ERT, secondary sources are excited simultaneously but in different ways, i.e. with distinct amplitude patterns, depending on the locations and amplitudes of primary sources. If the number of receivers is "large enough", different source configurations can lead to a set of observation vectors that span the data subspace. However, since sources that are spatially close to each other have highly correlated signatures, seperation of such signals becomes very difficult in the presence of noise. To overcome this problem we consider iterative MUSIC algorithms like R-MUSIC and RAP-MUSIC. These recursive algorithms pose a computational burden as they require multiple large combinatorial searches. Results obtained with these algorithms using simulated data of different conductivity patterns are presented.

  16. Scaling Up Coordinate Descent Algorithms for Large ℓ1 Regularization Problems

    Energy Technology Data Exchange (ETDEWEB)

    Scherrer, Chad; Halappanavar, Mahantesh; Tewari, Ambuj; Haglin, David J.

    2012-07-03

    We present a generic framework for parallel coordinate descent (CD) algorithms that has as special cases the original sequential algorithms of Cyclic CD and Stochastic CD, as well as the recent parallel Shotgun algorithm of Bradley et al. We introduce two novel parallel algorithms that are also special cases---Thread-Greedy CD and Coloring-Based CD---and give performance measurements for an OpenMP implementation of these.

  17. A Typology of Engineering Designs in Problem-Based Projects

    DEFF Research Database (Denmark)

    Larsen, Samuel Brüning; Bigum, Per Valentin

    include a set of general characteristics of great engineering solutions and a typology of three solution archetypes. The study labels these archetypes as 1) the adapted solution, 2) the “either/or”-solution, and 3) the multiple-elements solution. For each archetype, the paper specifies the corresponding...... class of problems that the archetype can logically address. In addition, the paper delineates (1) how each archetype relates to a project’s analysis and (2) how each archetype is evaluated, implemented and operated. The typology aids both students and project supervisors in conducting reports...

  18. Enhancing students' higher order thinking skills through computer-based scaffolding in problem-based learning

    Science.gov (United States)

    Kim, Nam Ju

    This multiple paper dissertation addressed several issues in Problem-based learning (PBL) through conceptual analysis, meta-analysis, and empirical research. PBL is characterized by ill-structured tasks, self-directed learning process, and a combination of individual and cooperative learning activities. Students who lack content knowledge and problem-solving skills may struggle to address associated tasks that are beyond their current ability levels in PBL. This dissertation addressed a) scaffolding characteristics (i.e., scaffolding types, delivery method, customization) and their effects on students' perception of optimal challenge in PBL, b) the possibility of virtual learning environments for PBL, and c) the importance of information literacy for successful PBL learning. Specifically, this dissertation demonstrated the effectiveness of scaffolding customization (i.e., fading, adding, and fading/adding) to enhance students' self-directed learning in PBL. Moreover, the effectiveness of scaffolding was greatest when scaffolding customization is self-selected than based on fixed-time interval and their performance. This suggests that it might be important for students to take responsibility for their learning in PBL and individualized and just-in-time scaffolding can be one of the solutions to address K-12 students' difficulties in improving problem-solving skills and adjusting to PBL.

  19. Analysis of problem solving on project based learning with resource based learning approach computer-aided program

    Science.gov (United States)

    Kuncoro, K. S.; Junaedi, I.; Dwijanto

    2018-03-01

    This study aimed to reveal the effectiveness of Project Based Learning with Resource Based Learning approach computer-aided program and analyzed problem-solving abilities in terms of problem-solving steps based on Polya stages. The research method used was mixed method with sequential explanatory design. The subject of this research was the students of math semester 4. The results showed that the S-TPS (Strong Top Problem Solving) and W-TPS (Weak Top Problem Solving) had good problem-solving abilities in each problem-solving indicator. The problem-solving ability of S-MPS (Strong Middle Problem Solving) and (Weak Middle Problem Solving) in each indicator was good. The subject of S-BPS (Strong Bottom Problem Solving) had a difficulty in solving the problem with computer program, less precise in writing the final conclusion and could not reflect the problem-solving process using Polya’s step. While the Subject of W-BPS (Weak Bottom Problem Solving) had not been able to meet almost all the indicators of problem-solving. The subject of W-BPS could not precisely made the initial table of completion so that the completion phase with Polya’s step was constrained.

  20. The Case of Web-Based Course on Taxation: Current Status, Problems and Future Improvement

    Science.gov (United States)

    Qin, Zhigang

    This paper mainly introduces the case of the web-based course on taxation developed by Xiamen University. We analyze the current status, problems and future improvement of the web-based course. The web-based course has the basic contents and modules, but it has several problems including unclear object, lacking interaction, lacking examination module, lacking study management module, and the learning materials and the navigation are too simple. According to its problems, we put forward the measures to improve it.