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.
A rating scale for tutor evaluation in a problem-based curriculum: Validity and reliability
D.H.J.M. Dolmans (Diana); I.H.A.P. Wolfhagen (Ineke); H.G. Schmidt (Henk); C.P.M. van der Vleuten (Cees)
1994-01-01
textabstractAn instrument has been developed to assess tutor performance in problem-based tutorial groups. This tutor evaluation questionnaire consists of 13 statements reflecting the tutor's behaviour. The statements are based on a description of the tasks set for the tutor. This study reports
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.
Solving large-scale real-world telecommunication problems using a grid-based genetic algorithm
Luna, Francisco; Nebro, Antonio; Alba, Enrique; Durillo, Juan
2008-11-01
This article analyses the use of a grid-based genetic algorithm (GrEA) to solve a real-world instance of a problem from the telecommunication domain. The problem, known as automatic frequency planning (AFP), is used in a global system for mobile communications (GSM) networks to assign a number of fixed frequencies to a set of GSM transceivers located in the antennae of a cellular phone network. Real data instances of the AFP are very difficult to solve owing to the NP-hard nature of the problem, so combining grid computing and metaheuristics turns out to be a way to provide satisfactory solutions in a reasonable amount of time. GrEA has been deployed on a grid with up to 300 processors to solve an AFP instance of 2612 transceivers. The results not only show that significant running time reductions are achieved, but that the search capability of GrEA clearly outperforms that of the equivalent non-grid algorithm.
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
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
. 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...... projects. The ESA Educational Office associated a technical coordinator and an administrative coordinator with the project. Since the foundation of Aalborg University (AAU) in 1974 the engineering educations has been based on Problem Based Learning (PBL). Within the engineering education skills...... project - due to time frame, the project and the variety of students involved. After the launch the project has been acknowledged from ESA top leadership as a very high quality student corner project. Jens Dalsgaard Nielsen Assoc Prof. PhD Msc EE Aalborg University Department of Control Engineering...
Kronk, Rebecca; Bishop, Ellen E.; Raspa, Melissa; Bickel, Julie O.; Mandel, Daniel A.; Bailey, Donald B.
2010-01-01
Study Objectives: This study reports on current child sleep difficulties reported by parents of children with Fragile X syndrome (FXS). We address prevalence and type of sleep problems (e.g., difficulty falling asleep, frequent awakenings); type and effectiveness of medical and behavioral treatments (e.g., medication, surgery, environmental changes); and explore specific child and family characteristics (e.g., child age, child gender, co-occurring conditions) as possible predictors of child sleep difficulties. Design/Participants: This study is part of a larger survey addressing needs of families with children with FXS. This article focuses on the families who responded to the survey sleep questions, had one or more children with the full mutation FXS, and who reside in the United States. The mean age for male and female children in this group was 15 years and 16 years respectively (N = 1,295). Results: Parents reported that 32% of the children with FXS currently experience sleep difficulties; 84% of those children are reported to have ≥ 2 current sleep problems. Problems falling asleep and frequent night awakenings were the most frequently reported difficulties; 47% of males and 40% of females received ≥1 medication to help with sleep. Children with more problematic health or behavioral characteristics had a higher likelihood of having current sleep problems. Conclusions: Our survey provides the most representative sample to date of sleep problems in children with FXS or any other neurodevelopmental disability. This large scale survey establishes a foundation for the prevalence of sleep disorders in children with FXS. Citation: Kronk R; Bishop EE; Raspa M; Bickel JO; Mandel DA; Bailey DB. Prevalence, nature, and correlates of sleep problems among children with fragile x syndrome based on a large scale parent survey. SLEEP 2010;33(5):679-687. PMID:20469810
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.
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Saucier, Antoine [Ecole Polytechnique de Montreal, C.P. 6079, Station centre-ville, Montreal (Que.), H3C-3A7 (Canada)]. E-mail: Antoine.Saucier@polymtl.ca; Soumis, Francois [Ecole Polytechnique de Montreal, C.P. 6079, Station centre-ville, Montreal (Que.), H3C-3A7 (Canada)]. E-mail: Francois.Soumis@gerad.ca
2006-06-15
The characterization of irregular objects with fractal methods often leads to the estimation of the slope of a function which is plotted versus a scale parameter. The slope is usually obtained with a linear regression. The problem is that the fit is usually not acceptable from the statistical standpoint. We propose a new approach in which we use two straight lines to bound the data from above and from below. We call these lines the upper and lower linear bounds. We propose to define these bounds as the solution of an optimization problem. We discuss the solution of this problem and we give an algorithm to obtain its solution. We use the difference between the upper and lower linear bounds to define a measure of the degree of linearity in the scaling range. We illustrate our method by analyzing the fluctuations of the variogram in a microresistivity well log from an oil reservoir in the North Sea.
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
Directory of Open Access Journals (Sweden)
Paola Cappola
2014-01-01
Full Text Available In this current work, I am proposing a general close examination of Problem Based Learning as a student centered educational method in which a problem constitutes the starting point of the learning process. Such a method provides students with the suitable knowledge for problem solving and presents numerous and significant differences compared to traditional education.In particular, I analyze the theoretic aspects of problem learning by tracing a history and presenting its structure, clarifying the role of the tutor in the various phases of the learning process. The method has found a wide diffusion since the beginning of the 70s and numerous studies have confirmed the advantages. The effectiveness of PBL is construable and is based on principles of constructivism and cognitivism.
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...
Scaling of Attitudes Toward Population Problems
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,…
Scale problems in reporting landscape pattern at the regional scale
R.V. O' Neill; C.T. Hunsaker; S.P. Timmins; B.L. Jackson; K.B. Jones; Kurt H. Riitters; James D. Wickham
1996-01-01
Remotely sensed data for Southeastern United States (Standard Federal Region 4) are used to examine the scale problems involved in reporting landscape pattern for a large, heterogeneous region. Frequency distribu-tions of landscape indices illustrate problems associated with the grain or resolution of the data. Grain should be 2 to 5 times smaller than the...
DEFF Research Database (Denmark)
de Graaff, Erik; Guerra, Aida
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......, 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...... in Engineering Education. In answer to the requests for visits the Aalborg Centre for Problem Based Learning in Engineering Science and Sustainability under the auspices of UNESCO (UCPBL) a two days programme for visitors is offered two times a year. The workshop is an introduction workshop to the Aalborg PBL...
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
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.
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Akcelik, Volkan [ORNL; Flath, Pearl [University of Texas, Austin; Ghattas, Omar [University of Texas, Austin; Hill, Judith C [ORNL; Van Bloemen Waanders, Bart [Sandia National Laboratories (SNL); Wilcox, Lucas [University of Texas, Austin
2011-01-01
We consider the problem of estimating the uncertainty in large-scale linear statistical inverse problems with high-dimensional parameter spaces within the framework of Bayesian inference. When the noise and prior probability densities are Gaussian, the solution to the inverse problem is also Gaussian, and is thus characterized by the mean and covariance matrix of the posterior probability density. Unfortunately, explicitly computing the posterior covariance matrix requires as many forward solutions as there are parameters, and is thus prohibitive when the forward problem is expensive and the parameter dimension is large. However, for many ill-posed inverse problems, the Hessian matrix of the data misfit term has a spectrum that collapses rapidly to zero. We present a fast method for computation of an approximation to the posterior covariance that exploits the lowrank structure of the preconditioned (by the prior covariance) Hessian of the data misfit. Analysis of an infinite-dimensional model convection-diffusion problem, and numerical experiments on large-scale 3D convection-diffusion inverse problems with up to 1.5 million parameters, demonstrate that the number of forward PDE solves required for an accurate low-rank approximation is independent of the problem dimension. This permits scalable estimation of the uncertainty in large-scale ill-posed linear inverse problems at a small multiple (independent of the problem dimension) of the cost of solving the forward problem.
Directory of Open Access Journals (Sweden)
David Esema
2012-12-01
Full Text Available Problem-Based Learning (PBL, adalah model pembelajaran yang awalnya dikembangkan di dunia pendidikan medis, namun kini telah digunakan secara luas di berbagai jenjang dan bidang pendidikan. Basis teortits dari PBL adalah kolaborativisme dan konstruktivisme. Kemitraan, keterbukaan dan kejujuran, rasa hormat, dan kepercayaan menjadi nilai-nilai yang mendasari dan sekaligus menjadi prasyarat bagi keberhasilan PBL Sintaks PBL meliputi: pengenalan dan pemahaman konsep dasar, eksplorasi fakta dan informasi relevan secara mandiri, bertukar pemahaman dalam kelompok/kelas, kesimpulan dan evaluasi. Beberapa riset mengenai PBL baik di luar maupun di dalam negeri yang dipaparkan dan dibandingkan dalam tulisan ini menunjukkan data tentang efektifitas PBL dalam kegiatan pembelajaran.
DEFF Research Database (Denmark)
Kolbæk, Ditte
2018-01-01
Problem- and project- based learning (PBL) was originally developed for collaboration between physically present students and teachers, but political decisions at many universities also require that collaboration, dialogues, and other PBL activities take place online. Teachers design learning...... “How do two online learning designs affect student engagement in the PBL online modules?” The empirical data were collected and analyzed using a netnographic approach. The study finds that concepts such as self-directed learning and active involvement may be perceived very differently from the students...... situations with the intention of supporting the students. This study investigates how technology influenced the interaction between teachers and students and between students in two different online modules for master’s students at Aalborg University, Denmark. The study aims to answer the research question...
Stabilization Algorithms for Large-Scale Problems
DEFF Research Database (Denmark)
Jensen, Toke Koldborg
2006-01-01
-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......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...
Bonus algorithm for large scale stochastic nonlinear programming problems
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 ...
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.......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...
Development of MMPI-A alcohol/drug problem scales.
Weed, N C; Butcher, J N; Williams, C L
1994-05-01
The present study introduces two new scales for the assessment of alcohol and other drug problems developed from the new Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A), including the rationally constructed Alcohol/Drug Problems Acknowledgement Scale (ACK) and the empirically-derived Alcohol/Drug Problems Proneness Scale (PRO). Validity of these scales is examined by comparing scores from a sample of adolescents hospitalized for alcohol and other drug problems with a normative sample of adolescents and with a sample of adolescents in psychiatric inpatient treatment. Results suggest that ACK and PRO show promise in the detection and description of alcohol and other drug problems in young people. Comparisons of ACK and PRO with other adult-derived MMPI-2 scales (e.g., the MacAndrew Alcoholism Scale, MAC-R and the Addiction Potential Scale) provide support for the practice of developing age-appropriate instruments for adolescents.
Shacham, Mordechai; Cutlip, Michael B.; Brauner, Neima
2009-01-01
A continuing challenge to the undergraduate chemical engineering curriculum is the time-effective incorporation and use of computer-based tools throughout the educational program. Computing skills in academia and industry require some proficiency in programming and effective use of software packages for solving 1) single-model, single-algorithm…
Solving large scale traveling salesman problems by chaotic neurodynamics.
Hasegawa, Mikio; Ikeguch, Tohru; Aihara, Kazuyuki
2002-03-01
We propose a novel approach for solving large scale traveling salesman problems (TSPs) by chaotic dynamics. First, we realize the tabu search on a neural network, by utilizing the refractory effects as the tabu effects. Then, we extend it to a chaotic neural network version. We propose two types of chaotic searching methods, which are based on two different tabu searches. While the first one requires neurons of the order of n2 for an n-city TSP, the second one requires only n neurons. Moreover, an automatic parameter tuning method of our chaotic neural network is presented for easy application to various problems. Last, we show that our method with n neurons is applicable to large TSPs such as an 85,900-city problem and exhibits better performance than the conventional stochastic searches and the tabu searches.
Even order self adjoint time scale problems
Directory of Open Access Journals (Sweden)
Douglas R. Anderson
2005-02-01
Full Text Available Even order self adjoint differential time scale expressions are introduced, together with associated self adjoint boundary conditions; the result is established by induction. Several fourth-order nabla-delta delta-nabla examples are given for select self adjoint boundary conditions, together with the specific corresponding Green's functions over common time scales. One derived Green's function is shown directly to be symmetric.
Problem Based Learning and sustainability
DEFF Research Database (Denmark)
Pizzol, Massimo; Løkke, Søren; Schmidt, Jannick Højrup
Problem-Based Learning (PBL) is a style of active learning based on problem solving. PBL aims at providing university students with flexible knowledge, capacity to self-learning, and skills in problem solving and collaboration. In this context, the present study explores the advantages and challe......Problem-Based Learning (PBL) is a style of active learning based on problem solving. PBL aims at providing university students with flexible knowledge, capacity to self-learning, and skills in problem solving and collaboration. In this context, the present study explores the advantages...... and challenges that the PBL model offers for developing five key competences in sustainability: (i) system thinking, (ii) interpersonal competence, (iii) anticipatory competence, (iv) strategic competence, (v) normative competences. The study draws on the experiences from PBL activities performed at Aalborg...... University (AAU), Denmark, and focuses on the teaching of Life Cycle Assessment as a method for sustainability assessment. The objective is providing recommendations for future LCA teaching and learning. PBL activites performed at AAU were evaluated critically to detemine to what extent they addressed...
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.
Biological Scaling Problems and Solutions in Amphibians.
Levy, Daniel L; Heald, Rebecca
2015-08-10
Size is a primary feature of biological systems that varies at many levels, from the organism to its constituent cells and subcellular structures. Amphibians populate some of the extremes in biological size and have provided insight into scaling mechanisms, upper and lower size limits, and their physiological significance. Body size variation is a widespread evolutionary tactic among amphibians, with miniaturization frequently correlating with direct development that occurs without a tadpole stage. The large genomes of salamanders lead to large cell sizes that necessitate developmental modification and morphological simplification. Amphibian extremes at the cellular level have provided insight into mechanisms that accommodate cell-size differences. Finally, how organelles scale to cell size between species and during development has been investigated at the molecular level, because subcellular scaling can be recapitulated using Xenopus in vitro systems. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.
Kim, Eunwoo; Lee, Minsik; Choi, Chong-Ho; Kwak, Nojun; Oh, Songhwai
2015-02-01
Low-rank matrix approximation plays an important role in the area of computer vision and image processing. Most of the conventional low-rank matrix approximation methods are based on the l2 -norm (Frobenius norm) with principal component analysis (PCA) being the most popular among them. However, this can give a poor approximation for data contaminated by outliers (including missing data), because the l2 -norm exaggerates the negative effect of outliers. Recently, to overcome this problem, various methods based on the l1 -norm, such as robust PCA methods, have been proposed for low-rank matrix approximation. Despite the robustness of the methods, they require heavy computational effort and substantial memory for high-dimensional data, which is impractical for real-world problems. In this paper, we propose two efficient low-rank factorization methods based on the l1 -norm that find proper projection and coefficient matrices using the alternating rectified gradient method. The proposed methods are applied to a number of low-rank matrix approximation problems to demonstrate their efficiency and robustness. The experimental results show that our proposals are efficient in both execution time and reconstruction performance unlike other state-of-the-art methods.
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.
Scaled first-order methods for a class of large-scale constrained least square problems
Coli, Vanna Lisa; Ruggiero, Valeria; Zanni, Luca
2016-10-01
Typical applications in signal and image processing often require the numerical solution of large-scale linear least squares problems with simple constraints, related to an m × n nonnegative matrix A, m « n. When the size of A is such that the matrix is not available in memory and only the operators of the matrix-vector products involving A and AT can be computed, forward-backward methods combined with suitable accelerating techniques are very effective; in particular, the gradient projection methods can be improved by suitable step-length rules or by an extrapolation/inertial step. In this work, we propose a further acceleration technique for both schemes, based on the use of variable metrics tailored for the considered problems. The numerical effectiveness of the proposed approach is evaluated on randomly generated test problems and real data arising from a problem of fibre orientation estimation in diffusion MRI.
The problem of scale in planetary geomorphology
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.
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.
Characteristics of Problems in Problem-based Learning
N. Sockalingam (Nachamma)
2010-01-01
textabstractThis thesis focuses on characteristics of problems in Problem-based Learning (PBL). Problems initiate the students’ learning process in PBL. Several studies have shown that the quality of problems has a positive influence on students’ academic achievement and interest. In addition, the
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....
Large-Scale Inverse Problems and Quantification of Uncertainty
Biegler, Lorenz; Ghattas, Omar
2010-01-01
Large-scale inverse problems and associated uncertainty quantification has become an important area of research, central to a wide range of science and engineering applications. Written by leading experts in the field, Large-scale Inverse Problems and Quantification of Uncertainty focuses on the computational methods used to analyze and simulate inverse problems. The text provides PhD students, researchers, advanced undergraduate students, and engineering practitioners with the perspectives of researchers in areas of inverse problems and data assimilation, ranging from statistics and large-sca
Local supersymmetry and the problem of the mass scales
Energy Technology Data Exchange (ETDEWEB)
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.
On solving large-scale polynomial convex problems by randomized first order algorithms
Ben-Tal, A.; Nemirovski, A.
2015-01-01
One of the most attractive recent approaches to processing well-structured large-scale convex optimization problems is based on smooth convex-concave saddle point reformulation of the problem of interest and solving the resulting problem by a fast first order saddle point method utilizing smoothness
Performance of Grey Wolf Optimizer on large scale problems
Gupta, Shubham; Deep, Kusum
2017-01-01
For solving nonlinear continuous problems of optimization numerous nature inspired optimization techniques are being proposed in literature which can be implemented to solve real life problems wherein the conventional techniques cannot be applied. Grey Wolf Optimizer is one of such technique which is gaining popularity since the last two years. The objective of this paper is to investigate the performance of Grey Wolf Optimization Algorithm on large scale optimization problems. The Algorithm is implemented on 5 common scalable problems appearing in literature namely Sphere, Rosenbrock, Rastrigin, Ackley and Griewank Functions. The dimensions of these problems are varied from 50 to 1000. The results indicate that Grey Wolf Optimizer is a powerful nature inspired Optimization Algorithm for large scale problems, except Rosenbrock which is a unimodal function.
Problem based learning: Cognitive and metacognitive processes during problem analysis
W.S. de Grave; H.P.A. Boshuizen (Henny); H.G. Schmidt (Henk)
1996-01-01
textabstractAn important phase of problem-based learning in a tutorial group is problem analysis. This article describes a study investigating the ongoing cognitive and metacognitive processes during problem analysis, by analysing the verbal communication among group members, and their thinking
Problem effectiveness in a course using problem-based learning
D.H.J.M. Dolmans (Diana); W.H. Gijselaers (Wim); H.G. Schmidt (Henk); S.B. van der Meer
1993-01-01
textabstractBackground. Problem-based learning (PBL) emphasizes active generation of learning issues by students. Both students and reachers, however, tend to worry that not all important knowledge will be acquired. To explore this question, problem effectiveness (i.e., for each problem, the degree
DEFF Research Database (Denmark)
Lusby, Richard Martin; Muller, Laurent Flindt; Petersen, Bjørn
2013-01-01
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...
Solving Large-scale Eigenvalue Problems in SciDACApplications
Energy Technology Data Exchange (ETDEWEB)
Yang, Chao
2005-06-29
Large-scale eigenvalue problems arise in a number of DOE applications. This paper provides an overview of the recent development of eigenvalue computation in the context of two SciDAC applications. We emphasize the importance of Krylov subspace methods, and point out its limitations. We discuss the value of alternative approaches that are more amenable to the use of preconditioners, and report the progression using the multi-level algebraic sub-structuring techniques to speed up eigenvalue calculation. In addition to methods for linear eigenvalue problems, we also examine new approaches to solving two types of non-linear eigenvalue problems arising from SciDAC applications.
Problems of allometric scaling analysis : Examples from mammalian reproductive biology
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
Features and characteristics of problem based learning
Eser Ceker; Fezile Ozdamli
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 for the latest technology supported tools of Problem Based Learning). This research showed that the most researched characteristics of PBL are; tea...
Existence of Solutions for Nonlinear Four-Point -Laplacian Boundary Value Problems on Time Scales
Directory of Open Access Journals (Sweden)
Topal SGulsan
2009-01-01
Full Text Available We are concerned with proving the existence of positive solutions of a nonlinear second-order four-point boundary value problem with a -Laplacian operator on time scales. The proofs are based on the fixed point theorems concerning cones in a Banach space. Existence result for -Laplacian boundary value problem is also given by the monotone method.
Features and Characteristics of Problem Based Learning
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…
Solving Large-Scale Inverse Magnetostatic Problems using the Adjoint Method
Bruckner, Florian; Wautischer, Gregor; Huber, Christian; Vogler, Christoph; Hinze, Michael; Suess, Dieter
2016-01-01
An efficient algorithm for the reconstruction of the magnetization state within magnetic components is presented. The occurring inverse magnetostatic problem is solved by means of an adjoint approach, based on the Fredkin-Koehler method for the solution of the forward problem. Due to the use of hybrid FEM-BEM coupling combined with matrix compression techniques the resulting algorithm is well suited for large-scale problems. Furthermore the reconstruction of the magnetization state within a permanent magnet is demonstrated.
Problem-based learning: rationale and description
H.G. Schmidt (Henk)
1983-01-01
textabstractProblem-based learning is an instructional method that is said to provide students with knowledge suitable for problem solving. In order to test this assertion the process of problem-based learning is described and measured against three principles of learning: activation of prior
Dressed skeleton expansion and the coupling scale ambiguity problem
Energy Technology Data Exchange (ETDEWEB)
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 [mu][sup 2] [approximately] Q[sub min][sup 2]Q[sub med][sup 2]/Q[sub max][sup 2] where Q[sub min][sup 2]Q[sub med][sup 2]/Q[sub max][sup 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.
Dressed skeleton expansion and the coupling scale ambiguity problem
Energy Technology Data Exchange (ETDEWEB)
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 {mu}{sup 2} {approximately} Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} where Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 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.
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
Finite-Size Scaling in Random K-SAT Problems
Ha, Meesoon; Lee, Sang Hoon; Jeon, Chanil; Jeong, Hawoong
2010-03-01
We propose a comprehensive view of threshold behaviors in random K-satisfiability (K-SAT) problems, in the context of the finite-size scaling (FSS) concept of nonequilibrium absorbing phase transitions using the average SAT (ASAT) algorithm. In particular, we focus on the value of the FSS exponent to characterize the SAT/UNSAT phase transition, which is still debatable. We also discuss the role of the noise (temperature-like) parameter in stochastic local heuristic search algorithms.
Problems of allometric scaling analysis: examples from mammalian reproductive biology.
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
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......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...
Problem Solving Reasoning and Problem Based Instruction in Geometry Learning
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.
Test Problems for Large-Scale Multiobjective and Many-Objective Optimization.
Cheng, Ran; Jin, Yaochu; Olhofer, Markus; Sendhoff, Bernhard
2017-12-01
The interests in multiobjective and many-objective optimization have been rapidly increasing in the evolutionary computation community. However, most studies on multiobjective and many-objective optimization are limited to small-scale problems, despite the fact that many real-world multiobjective and many-objective optimization problems may involve a large number of decision variables. As has been evident in the history of evolutionary optimization, the development of evolutionary algorithms (EAs) for solving a particular type of optimization problems has undergone a co-evolution with the development of test problems. To promote the research on large-scale multiobjective and many-objective optimization, we propose a set of generic test problems based on design principles widely used in the literature of multiobjective and many-objective optimization. In order for the test problems to be able to reflect challenges in real-world applications, we consider mixed separability between decision variables and nonuniform correlation between decision variables and objective functions. To assess the proposed test problems, six representative evolutionary multiobjective and many-objective EAs are tested on the proposed test problems. Our empirical results indicate that although the compared algorithms exhibit slightly different capabilities in dealing with the challenges in the test problems, none of them are able to efficiently solve these optimization problems, calling for the need for developing new EAs dedicated to large-scale multiobjective and many-objective optimization.
Problem-based learning and radiology
Energy Technology Data Exchange (ETDEWEB)
Thurley, P. [Department of Radiology, Nottingham University Hospitals, Queens Medical Centre, Nottingham (United Kingdom)], E-mail: peter.thurley@ntlworld.com; Dennick, R. [Medical Education Unit, Medical School, University of Nottingham, Nottingham (United Kingdom)
2008-06-15
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.
"Conscientization," Dialogue and Collaborative Problem Based Learning
Armitage, Andrew
2013-01-01
It has been argued that Paulo Freire's concept of conscientization, where critical awareness and engagement are central to a problem-posing pedagogy, provides the philosophical principles to underpin Problem Based Learning (PBL). By using dialogue groups and a combination of learning strategies to discover the nature of a problem, understand its…
Understanding hydraulic fracturing: a multi-scale problem
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
Directory of Open Access Journals (Sweden)
Marić Miroslav
2015-01-01
Full Text Available In this study, we consider a variant of the Bilevel Uncapacitated Facility Location Problem (BLUFLP, in which the clients choose suppliers based on their own preferences. We propose and compare three metaheuristic approaches for solving this problem: Particle Swarm Optimization (PSO, Simulated Annealing (SA, and a combination of Reduced and Basic Variable Neighborhood Search Method (VNS. We used the representation of solutions and objective function calculation that are adequate for all three proposed methods. Additional strategy is implemented in order to provide significant time savings when evaluating small changes of solution's code in improvement parts. Constructive elements of each of the proposed algorithms are adapted to the problem under consideration. The results of broad computational tests on modified problem instances from the literature show good performance of all three proposed methods, even on large problem dimensions. However, the obtained results indicate that the proposed VNS-based has significantly better performance compared to SA and PSO approaches, especially when solving large-scale problem instances. Computational experiments on large scale benchmarks demonstrate that the VNS-based method is fast, competitive, and able to find high-quality solutions, even for large-scale problem instances with up to 2000 clients and 2000 potential facilities within reasonable CPU times.
Leadership solves collective action problems in small-scale societies
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
Leadership solves collective action problems in small-scale societies.
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).
Transformation to problem and project based learning
DEFF Research Database (Denmark)
Kolmos, Anette
2006-01-01
. However, the internal factors at the institutional level may be unknown. Institutions have developed many different pedagogical models, using very different strategies for development. Nearly all Danish engineering institutions have implemented elements of Problem Based and Project Based Learning (PBL...
Problem-Based Learning Approaches in Meteorology
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…
Problem-Based Learning in Prenursing Courses.
González-Jiménez, Emilio; Enrique-Mirón, Carmen; González-García, Juan A; Fernández-Carballo, Daniel
2016-01-01
We conducted an observational study with 150 undergraduate nursing students to verify the usefulness of problem-based learning in the classroom and to ascertain whether this methodology facilitated the development of their knowledge acquisition skills. Problem-based learning fostered the development of integrated knowledge acquisition skills among nursing students.
Students' Perceptions of Problem-Based Learning
Kumar, Muthu; Kogut, Galyna
2006-01-01
Problem-based learning has in recent times aroused keen curiosity due to its pedagogical orientation of facilitating students' active construction of knowledge. As a curriculum model it is designed based upon the solving of either simulated or real-life problems that generally tend to be ill-structured and open-ended. In such a model students are…
Boundary element method solution for large scale cathodic protection problems
Rodopoulos, D. C.; Gortsas, T. V.; Tsinopoulos, S. V.; Polyzos, D.
2017-12-01
Cathodic protection techniques are widely used for avoiding corrosion sequences in offshore structures. The Boundary Element Method (BEM) is an ideal method for solving such problems because requires only the meshing of the boundary and not the whole domain of the electrolyte as the Finite Element Method does. This advantage becomes more pronounced in cathodic protection systems since electrochemical reactions occur mainly on the surface of the metallic structure. The present work aims to solve numerically a sacrificial cathodic protection problem for a large offshore platform. The solution of that large-scale problem is accomplished by means of “PITHIA Software” a BEM package enhanced by Hierarchical Matrices (HM) and Adaptive Cross Approximation (ACA) techniques that accelerate drastically the computations and reduce memory requirements. The nonlinear polarization curves for steel and aluminium in seawater are employed as boundary condition for the under protection metallic surfaces and aluminium anodes, respectively. The potential as well as the current density at all the surface of the platform are effectively evaluated and presented.
Relaxing the weak scale: A new approach to the hierarchy problem
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.
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...... of how a problem based approach to learning will be implemented in the programs to support students in their engagement with the complexities of amalgamating and transgressing the disciplines of technology and anthropology. The paper is concluded by a brief discussion of problem based learning...... as an approach to operationalising interdisciplinary education, and some challenges are identified....
Foundation for Problem-Based Gaming
Kiili, Kristian
2007-01-01
Educational games may offer a viable strategy for developing students' problem-solving skills. However, the state of art of educational game research does not provide an account for that. Thus, the aim of this research is to develop an empirically allocated model about problem-based gaming that can be utilised to design pedagogically meaningful…
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...
Problem-based learning in astrophysics
Energy Technology Data Exchange (ETDEWEB)
Raine, Derek [Department of Physics and Astronomy, University of Leicester, Leicester (United Kingdom); Collett, James [Department of Physical Sciences, University of Hertfordshire, Hatfield (United Kingdom)
2003-03-01
Problem-based learning (PBL) can be integrated into the curriculum in many different ways. We compare three examples of PBL in undergraduate astrophysics programmes, and discuss the strengths and weaknesses of the various approaches.
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.
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.
van Lang, NDJ; Ferdinand, RF; Oldehinkel, AJ; Ormel, J; Verhulst, FC
2005-01-01
This study investigated the concurrent validity of the DSM-IV scales Anxiety Problems and Affective Problems of the Youth Self-Report (YSR) in a community sample of Dutch young adolescents aged 10-12 years. We first examined the extent to which the YSR/DSM-IV scales reflect symptoms of DSM-IV
Problem Based Learning, curriculum development and change ...
African Journals Online (AJOL)
Introduction: The faculty of Medicine, (FOM) Makerere University Kampala was started in 1924 and has been running a traditional curriculum for 79 years. A few years back it embarked on changing its curriculum from traditional to Problem Based Learning (PBL) and Community Based Education and Service (COBES) as ...
Problem Based Learning - Linking Students and Industry
DEFF Research Database (Denmark)
Fink, Flemming K.
2006-01-01
-oriented project work: students work in teams to solve externally defined problem areas in co-operation with businesses, organisations and public institutions. Project Organised Problem Based Learning (POPBL) has generated a high degree of cooperation with the society and private companies. There are all the time......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...... in working life; enterprises with a clear idea of what the university stands for and how the future graduates might fit in as prospective employees; and the university with feedback and cases and ideas which can be used in research and teaching. This presentation has a focus on POPBL in engineering, which...
Problem-based learning in the NICU.
Pilcher, Jobeth
2014-01-01
Problem-based learning (PBL) is an educational strategy that provides learners with the opportunity to investigate and solve realistic problem situations. It is also referred to as project-based learning or work-based learning. PBL combines several learning strategies including the use of case studies coupled with collaborative, facilitated, and self-directed learning. Research has demonstrated that use of PBL can result in learners having improved problem-solving skills, increased breadth and analysis of complex data, higher-level thinking skills, and improved collaboration. This article will include background information and a description of PBL, followed by examples of how this strategy can be used for learning in neonatal settings.
Enhance Environmental Literacy through Problem Based Learning
Febriasari, L. K.; Supriatna, N.
2017-09-01
This study aims to improve environmental literacy elementary school students in Bandung. The design of this study used a classroom action research consisting of four stages, planning, implementation, observation, and reflection. The results showed that there was an increase in the students’ environmental literacy. The conclusion of this research is that students’ environmental literacy can be improved through classroom learning by applying Problem Based Learning model. Learning planning is important which includes analysis of environmental literacy component and learning model that is used, Problem Based Learning, so that learning can run effectively, efficiently, and get maximum result. Efforts to improve environmental literacy should be sustainable.
Farrell, Albert D; Sullivan, Terri N; Goncy, Elizabeth A; Le, Anh-Thuy H
2016-06-01
This study evaluated the Problem Behavior Frequency Scale (PBFS), a self-report measure designed to assess adolescents' frequency of victimization, aggression, and other problem behaviors. Analyses were conducted on a sample of 5,532 adolescents from 37 schools at 4 sites. About half (49%) of participants were male; 48% self-identified as Black non-Hispanic; 21% as Hispanic, 18% as White non-Hispanic. Adolescents completed the PBFS and measures of beliefs and values related to aggression, and delinquent peer associations at the start of the 6th grade and over 2 years later. Ratings of participants' behavior were also obtained from teachers on the Behavioral Assessment System for Children. Confirmatory factor analyses supported a 7-factor model that differentiated among 3 forms of aggression (physical, verbal, and relational), 2 forms of victimization (overt and relational), drug use, and other delinquent behavior. Support was found for strong measurement invariance across gender, sites, and time. The PBFS factors generally showed the expected pattern of correlations with teacher ratings of adolescents' behavior and self-report measures of relevant constructs. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Mathematical programming methods for large-scale topology optimization problems
DEFF Research Database (Denmark)
Rojas Labanda, Susana
This thesis investigates new optimization methods for structural topology optimization problems. The aim of topology optimization is finding the optimal design of a structure. The physical problem is modelled as a nonlinear optimization problem. This powerful tool was initially developed for mech......This thesis investigates new optimization methods for structural topology optimization problems. The aim of topology optimization is finding the optimal design of a structure. The physical problem is modelled as a nonlinear optimization problem. This powerful tool was initially developed...... 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...
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...... the challenges in applying problem based learning strategies in a context where several universities, with different cultures of teaching, collaboratively develop and deliver online courses. We present a pedagogical framework embracing both problem based and curriculum based strategies and show how we used...... this as a basis for trying out various online learning strategies....
Image-scaling problem in the optical fractional Fourier transform.
Liu, S; Ren, H; Zhang, J; Zhang, X
1997-08-10
The significance of scale factors and cascade of optical fractional Fourier transform is emphasized. Exact and cascadable fractional Fourier transforms in practical applications mandate that the image scale be the reciprocal of the scale of the input plane controlled by the optical setup. The practical setup of the optical fractional Fourier transform must be without any quadratic phase term at the spectrum plane.
Problem-Based Learning in Online Environments
An, Yun-Jo; Reigeluth, Charles M.
2008-01-01
This study examined 3 graduate-level online courses that utilized problem-based learning (PBL), considering each course as a case. Beyond describing how PBL was implemented in each case, this study identified what worked (strengths) and did not work (weaknesses) in the PBL and explored how the PBL could be improved (improvements) by collecting…
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...
Producing and Scrounging during Problem Based Learning
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…
Collaborative Learning Utilizing Case-Based Problems
Hilvano, Nestor T.; Mathis, Karen M.; Schauer, Daniel P.
2014-01-01
Engaging students in discussion and creating high impact teaching and learning practices are a challenge in every classroom. Small group discussion and poster presentations were used to solve case-based problems to highlight issues for the learner and to allow each student to demonstrate understanding and application of theory to real life…
Scaffolds in Problem-Based Learning
S.S.Y. Choo (Serene)
2013-01-01
markdownabstract__Abstract__ Problem-based learning or PBL in short, is an instructional approach that helps students develop flexible understanding and lifelong learning skills (Hmelo-Silver, 2004; Schmidt, Loyens, Van Gog, & Paas, 2007; Simons & Klein, 2007). In general, the main instructional
Revitalizing Precalculus with Problem-Based Learning.
Stanley, Sonya S.
2002-01-01
Describes the ways in which a problem-based learning (PBL) approach to teaching precalculus can prepare students for calculus by helping students develop a conceptual understanding rather than learning through symbol manipulation and memorization. Discusses the exponential, trigonometric, polynomial, and rational function modules employed. (NB)
Teaching Gases through Problem-Based Learning
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…
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...
Case Based Heuristic Selection for Timetabling Problems
Burke, Edmund; Petrovic, Sanja; Qu, Rong
2006-01-01
This paper presents a case-based heuristic selection approach for automated university course and exam timetabling. The method described in this paper is motivated by the goal of developing timetabling systems that are fundamentally more general than the current state of the art. Heuristics that worked well in previous similar situations are memorized in a case base and are retrieved for solving the problem in hand. Knowledge discovery techniques are employed in two distinct scenarios. Firstl...
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.
Dysfunctional problem-based learning curricula: resolving the problem
2012-01-01
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. PMID:23009729
Routing problems based on hils system platform
Directory of Open Access Journals (Sweden)
Andrzej Adamski
2015-03-01
Full Text Available Background: The logistic systems are very complex socio-technical systems. In this paper the proposal of application of the hierarchical multi-layers system platform HILS approach for the solution of the complex vehicle routing problems is presented. The interactive system functional structure was proposed which by intelligent dedicated inter-layers interactions enables the professional solutions of these practical problems. To illustrate these capabilities the complex example of the real-time VRP-SPD-TW routing problem was presented in which upper layers offers the context-related real-time updating network specifications that stimulates the adequate routing parameters and specifications updating for problem solution in optimization layer. At the bottom dispatching control layer the DISCON (Dispatching CONtrol method from public transport was adopted to logistics applications in which the actual routing is treated as obligatory reference schedule to be stabilized. The intelligence aspects are related among others to HILS based decomposition, context-related trade-offs between routing modifications and corrective dispatching control capabilities e.g. priority or route guidance actions. Methods: Decomposition of the vehicle routing problem for the HILS layers tasks creating the ILS system hierarchical structure. Dedicated solution method for the VRP-SPD-TW routing problem. The recognition of the control preferences structure by AHP-Entropy methods. DISCON and PIACON multi-criteria interacting control methods. Results: Original formulation and solution of the vehicle routing problem by system-wide approach with essential practical advantages: consistency, lack of redundancy, essential reduction of dimension, dedicated formulation, multi-criteria approach, exploration of the integration and intelligence features supported by the intelligent PIACON-DISCON methods control activities Conclusions: The presented proposal creates the professional
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 professional and technical skills can be acquired and updated at a later stage in ones career while skills for problem-solving and skills for learning to learn can only be achieved through the process of academic training at he universities. The concept of project-organised education provides just...
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.
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.
Problem-based Simulations for the GSMT
Croft, Steven; Pompea, S. M.
2007-12-01
We are developing a set of multimedia-based instructional modules emphasizing technical and scientific aspects of the Giant Segmented Mirror Telescope project. The modules will be open-ended and problem-based to promote development of problem-solving skills. Problem-based-learning modules that emphasize work on open-ended complex real world problems are particularly valuable in illustrating and promoting a perspective on the process of science and engineering. Research in this area shows that these kinds of learning experiences are superior to more conventional student training regarding gains in student learning and problem-solving skills. The format for the modules will be based on the award-winning multi-media educational Astronomy Village products. Students are presented with a simulated environment: a mountaintop community surrounded by a cluster of telescopes, satellite receivers, and telecommunication towers. A number of "buildings” are found in the Village, including a library, a laboratory, and an auditorium. Each building contains an array of information sources and computer simulations. Students navigate through their research with a mentor via imbedded video. The first module will be "Observatory Site Selection.” Students will use astronomical data, basic weather information, and sky brightness data to select the best site for an observatory. Students will investigate the six GSMT sites considered by the professional site selection teams. Students will explore weather and basic site issues (e.g., roads and topography) using remote sensing images, computational fluid dynamics results, turbulence profiles, and scintillation of the different sites. The second module will address aspects of system engineering and optimization for a GSMT-like telescope.
Sparse deconvolution for the large-scale ill-posed inverse problem of impact force reconstruction
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.
Power, Democracy and Problem-Based Learning
DEFF Research Database (Denmark)
Du, Xiangyun; Stentoft, Diana; Dahms, Mona-Lisa
2007-01-01
as a starting point, an online course titled ‘Intercultural Learning' has been developed. The course is offered as a part of a faculty training programme, Master in Problem Based Learning in Engineering and Science (MPBL) (For more information about the MPBL programme, see Du et. al. 2007). Course and program...... and create an intercultural teaching and learning environment. One of the course sessions is titled ‘Education, Power and Democracy' and the contributions from participants to the discussion in the course forum have been an exciting inspiration for this paper. The first section of the paper...... 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...
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.
FEM × DEM: a new efficient multi-scale approach for geotechnical problems with strain localization
Nguyen, Trung Kien; Claramunt, Albert Argilaga; Caillerie, Denis; Combe, Gaël; Dal Pont, Stefano; Desrues, Jacques; Richefeu, Vincent
2017-06-01
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.
Implementation of Task-based and problem-based ...
African Journals Online (AJOL)
This paper describes implementation of new task-based and problem-based pharmacotherapy course for 3rd year pre-clinical medical students at Faculty of Medicine and Health Sciences, Omdurman Islamic University. Keywords: Pharmacotherapy, Task-based learning, P -drug. Sudan Journal of Medical Science Vol.
A deficit scaling algorithm for the minimum flow problem
Indian Academy of Sciences (India)
made continuous improvements to algorithms for solving several classes of problems. From the late 1940s through the 1950s, researchers designed many of the fundamental ... each task i, i = 1,... ,p is known. The workers must perform these tasks according to this schedule so that exactly one worker performs each task.
The complexity of wicked problems in large scale change
Waddock, S.; Meszoely, G.; Waddell, S.; Dentoni, D.
2015-01-01
Purpose – The purpose of this paper is to extend and elaborate the notion of successful organizational change to incorporate the concept of large system change (LSC), by developing a framework that brings together complexity and wicked problems theories to understand how individual organizations and
Teaching Problem Based Learning as Blended Learning
DEFF Research Database (Denmark)
Kolbæk, Ditte; Nortvig, Anne-Mette
2018-01-01
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......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...... program, and we present suggestions for designs for blended learning PBL based on case studies from two PBL courses...
Newton Methods for Large Scale Problems in Machine Learning
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…
Problem decomposition by mutual information and force-based clustering
Otero, Richard Edward
The scale of engineering problems has sharply increased over the last twenty years. Larger coupled systems, increasing complexity, and limited resources create a need for methods that automatically decompose problems into manageable sub-problems by discovering and leveraging problem structure. The ability to learn the coupling (inter-dependence) structure and reorganize the original problem could lead to large reductions in the time to analyze complex problems. Such decomposition methods could also provide engineering insight on the fundamental physics driving problem solution. This work forwards the current state of the art in engineering decomposition through the application of techniques originally developed within computer science and information theory. The work describes the current state of automatic problem decomposition in engineering and utilizes several promising ideas to advance the state of the practice. Mutual information is a novel metric for data dependence and works on both continuous and discrete data. Mutual information can measure both the linear and non-linear dependence between variables without the limitations of linear dependence measured through covariance. Mutual information is also able to handle data that does not have derivative information, unlike other metrics that require it. The value of mutual information to engineering design work is demonstrated on a planetary entry problem. This study utilizes a novel tool developed in this work for planetary entry system synthesis. A graphical method, force-based clustering, is used to discover related sub-graph structure as a function of problem structure and links ranked by their mutual information. This method does not require the stochastic use of neural networks and could be used with any link ranking method currently utilized in the field. Application of this method is demonstrated on a large, coupled low-thrust trajectory problem. Mutual information also serves as the basis for an
[Modeling continuous scaling of NDVI based on fractal theory].
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.
Knowledge formations in Problem Based Learning
DEFF Research Database (Denmark)
Larsen, Verner
The paper presents some of the results from a recent completed Ph.D. program about disciplinarity and inter-disciplinarity in problem based learning (PBL). Disciplinary content in PBL-programs has been questioned during recent years, so stronger concepts of how knowledge is actually organized...... and structured in PBL are needed to qualify this discussion. This paper focuses on the research question: How has the structuring/organization of knowledge in curriculum changed over time and what kinds of connections and interrelations between disciplines/subjects can be identified in current PBL...
Problem based learning - A brief review
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.
The workshop on iterative methods for large scale nonlinear problems
Energy Technology Data Exchange (ETDEWEB)
Walker, H.F. [Utah State Univ., Logan, UT (United States). Dept. of Mathematics and Statistics; Pernice, M. [Univ. of Utah, Salt Lake City, UT (United States). Utah Supercomputing Inst.
1995-12-01
The aim of the workshop was to bring together researchers working on large scale applications with numerical specialists of various kinds. Applications that were addressed included reactive flows (combustion and other chemically reacting flows, tokamak modeling), porous media flows, cardiac modeling, chemical vapor deposition, image restoration, macromolecular modeling, and population dynamics. Numerical areas included Newton iterative (truncated Newton) methods, Krylov subspace methods, domain decomposition and other preconditioning methods, large scale optimization and optimal control, and parallel implementations and software. This report offers a brief summary of workshop activities and information about the participants. Interested readers are encouraged to look into an online proceedings available at http://www.usi.utah.edu/logan.proceedings. In this, the material offered here is augmented with hypertext abstracts that include links to locations such as speakers` home pages, PostScript copies of talks and papers, cross-references to related talks, and other information about topics addresses at the workshop.
Leadership solves collective action problems in small-scale societies
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 c...
Vartiational Optimal-Control Problems with Delayed Arguments on Time Scales
Directory of Open Access Journals (Sweden)
Abdeljawad (Maraaba Thabet
2009-01-01
Full Text Available This paper deals with variational optimal-control problems on time scales in the presence of delay in the state variables. The problem is considered on a time scale unifying the discrete, the continuous, and the quantum cases. Two examples in the discrete and quantum cases are analyzed to illustrate our results.
Problem Gambling Family Impacts: Development of the Problem Gambling Family Impact Scale.
Dowling, N A; Suomi, A; Jackson, A C; Lavis, T
2016-09-01
Although family members of problem gamblers frequently present to treatment services, problem gambling family impacts are under-researched. The most commonly endorsed items on a new measure of gambling-related family impacts [Problem Gambling Family Impact Measure (PG-FIM: Problem Gambler version)] by 212 treatment-seeking problem gamblers included trust (62.5 %), anger (61.8 %), depression or sadness (58.7 %), anxiety (57.7 %), distress due to gambling-related absences (56.1 %), reduced quality time (52.4 %), and communication breakdowns (52.4 %). The PG-FIM (Problem Gambler version) was comprised of three factors: (1) financial impacts, (2) increased responsibility impacts, and (3) psychosocial impacts with good psychometric properties. Younger, more impulsive, non-electronic gaming machine (EGM) gamblers who had more severe gambling problems reported more financial impacts; non-EGM gamblers with poorer general health reported more increased responsibility impacts; and more impulsive non-EGM gamblers with more psychological distress and higher gambling severity reported more psychosocial impacts. The findings have implications for the development of interventions for the family members of problem gamblers.
Faculty development for problem-based learning.
Farmer, Elizabeth A
2004-05-01
Changing to a problem-based learning (PBL) curriculum represents a substantial challenge because many faculty members are unfamiliar with the process. Faculty development is a crucial component of successful curriculum change to PBL. This paper describes a logical process for designing and implementing a comprehensive faculty development programme at three main stages of change: curriculum transition, curriculum implementation and curriculum advancement. The components of each stage are discussed with reference to the literature and practice. Future advances in faculty development include harnessing the potential of complex adaptive systems theory in understanding and facilitating the change process, and incorporating the results of research, which illuminates the relationships of the PBL tutorial process to student achievement. There is a continuing need for rigorous outcome-based research and programme evaluation to define the best components and strategies for faculty development.
Problem Based Learning in Nursing Education
Directory of Open Access Journals (Sweden)
Weihua Zhang
2014-01-01
Full Text Available Background. McMaster University first introduced Problem Based Learning (PBL in the mid 1960s. However, measuring the relationship between PBL for undergraduate nursing programs and students test performance has not yet been assessed in the USA. Purpose. The main purpose of this paper is to describe the effectiveness of PBL on senior student test performance on content related to PBL in a BSN program. Diabetes mellitus and renal insufficiency were taught by traditional lecture format in the previous years. This was the first year we taught this content by the problem based learning method. Method. Historical control group was used to compare the test performances between the PBL groups and the traditional group using Student’s t-test. Result. The mean of diabetes mellitus related questions missed by the PBL group was less than the traditional group (t = 4.51, and P=.00. The mean of renal insufficiency related questions missed by the PBL group was more than the traditional group (t=-6.44, and P=.00. Discussion. This study produced inconclusive findings. Factors that could be attributed to their performance will be discussed.
Problem-based learning of research skills.
Davis, Thomas H; Wagner, Galen S; Gleim, Gilbert; Andolsek, Kathryn M; Arheden, Hakan; Austin, Robert; Courtney-Eighmy, Anne; Gradison, Margaret; Leist, James C; Maynard, Charles; Noga, Edwin M; Ostbye, Truls; Eisenstein, Eric L
2006-01-01
To determine whether a short-term, problem-based educational intervention leads to increased research activity among health care practitioners. Participant's success was evaluated as a composite of 2 outcomes. These were (1) reporting results for the project designed during the practicum and (2) conducting subsequent research activities. The study population included 36 clinical research outcomes projects developed by clinical practitioners, postgraduate trainees, and medical students during 6 separate practicums. All project teams received the same educational intervention, an "outcomes research practicum" that was divided into 4 primary learning modules administered over a 1 to 4 month period. Each module included a preparatory videotape lecture, supplemental readings, and a 90-minute interactive laboratory session during which faculty members worked with participants to develop answers to a series of predefined questions relating to the design of clinical outcomes research projects. Follow-up continued for a minimum of 12 months and a maximum of 36 months. Eighty-three percent of project teams completed all 4 practicum modules, and 69% completed one of the study outcomes (50% completed their research project and 47% completing a subsequent research activity). Practitioners were more likely to complete subsequent research activities, whereas trainees were more likely to complete their study project. This short-term, problem-based educational intervention was successful in increasing the collective research activities of participants. Further, more rigorous structured research is needed to determine the ultimate impact on practice change and patient outcomes.
On the performance of maximum-principle enforcing methods applied to large-scale subsurface problems
Karra, S.; Chang, J.; Nakshatrala, K.
2014-12-01
It is well known that numerical formulations (either finite element, finite volume or finite difference) do not meet maximum principles and the non-negative constraint for anisotropic diffusion equations. But these mathematical properties and physical constraints are important for predictive simulations in subsurface modeling. Recently, optimization-based methodologies have been proposed for diffusion-type equations that respect maximum principles and meet the non-negative constraint on general computational grids. Till date these methodologies have been tested only on small-scale academic problems with few thousands of degrees-of-freedom. But for practical problems in subsurface modeling, the degrees-of-freedom easily run into millions and sometimes into billions. The purpose of this research is to systematically study the performance of the non-negative methodologies for large-scale problems and in a parallel setting. We shall use PETSc for parallel environment, and TAO for parallel optimization solvers. Numerical simulations on real sites using our methodologies will be presented.
Directory of Open Access Journals (Sweden)
Ali Wagdy Mohamed
2017-01-01
Full Text Available This paper presents Differential Evolution algorithm for solving high-dimensional optimization problems over continuous space. The proposed algorithm, namely, ANDE, introduces a new triangular mutation rule based on the convex combination vector of the triplet defined by the three randomly chosen vectors and the difference vectors between the best, better, and the worst individuals among the three randomly selected vectors. The mutation rule is combined with the basic mutation strategy DE/rand/1/bin, where the new triangular mutation rule is applied with the probability of 2/3 since it has both exploration ability and exploitation tendency. Furthermore, we propose a novel self-adaptive scheme for gradual change of the values of the crossover rate that can excellently benefit from the past experience of the individuals in the search space during evolution process which in turn can considerably balance the common trade-off between the population diversity and convergence speed. The proposed algorithm has been evaluated on the 20 standard high-dimensional benchmark numerical optimization problems for the IEEE CEC-2010 Special Session and Competition on Large Scale Global Optimization. The comparison results between ANDE and its versions and the other seven state-of-the-art evolutionary algorithms that were all tested on this test suite indicate that the proposed algorithm and its two versions are highly competitive algorithms for solving large scale global optimization problems.
Implementation of an effective hybrid GA for large-scale traveling salesman problems.
Nguyen, Hung Dinh; Yoshihara, Ikuo; Yamamori, Kunihito; Yasunaga, Moritoshi
2007-02-01
This correspondence describes a hybrid genetic algorithm (GA) to find high-quality solutions for the traveling salesman problem (TSP). The proposed method is based on a parallel implementation of a multipopulation steady-state GA involving local search heuristics. It uses a variant of the maximal preservative crossover and the double-bridge move mutation. An effective implementation of the Lin-Kernighan heuristic (LK) is incorporated into the method to compensate for the GA's lack of local search ability. The method is validated by comparing it with the LK-Helsgaun method (LKH), which is one of the most effective methods for the TSP. Experimental results with benchmarks having up to 316228 cities show that the proposed method works more effectively and efficiently than LKH when solving large-scale problems. Finally, the method is used together with the implementation of the iterated LK to find a new best tour (as of June 2, 2003) for a 1904711-city TSP challenge.
Finite element solution techniques for large-scale problems in computational fluid dynamics
Liou, J.; Tezduyar, T. E.
1987-01-01
Element-by-element approximate factorization, implicit-explicit and adaptive implicit-explicit approximation procedures are presented for the finite-element formulations of large-scale fluid dynamics problems. The element-by-element approximation scheme totally eliminates the need for formation, storage and inversion of large global matrices. Implicit-explicit schemes, which are approximations to implicit schemes, substantially reduce the computational burden associated with large global matrices. In the adaptive implicit-explicit scheme, the implicit elements are selected dynamically based on element level stability and accuracy considerations. This scheme provides implicit refinement where it is needed. The methods are applied to various problems governed by the convection-diffusion and incompressible Navier-Stokes equations. In all cases studied, the results obtained are indistinguishable from those obtained by the implicit formulations.
Numerical integration of a relativistic two-body problem via a multiple scales method
Abouelmagd, Elbaz I.; Elshaboury, S. M.; Selim, H. H.
2016-01-01
We offer an analytical study on the dynamics of a two-body problem perturbed by small post-Newtonian relativistic term. We prove that, while the angular momentum is not conserved, the motion is planar. We also show that the energy is subject to small changes due to the relativistic effect. We also offer a periodic solution to this problem, obtained by a method based on the separation of time scales. We demonstrate that our solution is more general than the method developed in the book by Brumberg (Essential Relativistic Celestial Mechanics, Hilger, Bristol, 1991). The practical applicability of this model may be in studies of the long-term evolution of relativistic binaries (neutron stars or black holes).
Time asynchronous relative dimension in space method for multi-scale problems in fluid dynamics
Markesteijn, A. P.; Karabasov, S. A.
2014-02-01
A novel computational method is presented for solving fluid dynamics equations in the multi-scale framework when the system size is an important parameter of the governing equations. The method (TARDIS) is based on a concurrent transformation of the governing equations in space and time and solving the transformed equations on a uniform Cartesian grid with the corresponding causality conditions at the grid interfaces. For implementation in the framework of TARDIS, the second-order CABARET scheme of Karabasov and Goloviznin [1] is selected for it provides a good combination of numerical accuracy, computational efficiency and simplicity of realisation. Numerical examples are first provided for several isothermal gas dynamics test problems and then for modelling of molecular fluctuations inside a microscopic flow channel and ultrasound wave propagation through a nano-scale region of molecular fluctuations.
Beyond Problem-Based Learning: Using Dynamic PBL in Chemistry
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…
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.
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.
Optimal Experimental Design for Large-Scale Bayesian Inverse Problems
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.
Problem Based Learning (PBL): a conundrum.
Wells, Samantha H; Warelow, Philip J; Jackson, Karen L
2009-10-01
Problem Based Learning (PBL) using minimal guided instruction is used as an educational strategy across a broad variety of disciplines in the tertiary sector. This paper includes some of the strengths and weaknesses of PBL, both in general and in relation to the health care setting, encompassing some of its philosophical underpinnings and its methodological approach. In an effort to explore some of the benefits and problems with PBL in the work setting, this account will comprise a realistic rather than idealistic focus and will include a range of perspectives from both a facilitator and student standpoint. We suggest that PBL is a useful strategy across a comprehensive nursing degree programme (as the ideal) provided the learning programme is supported financially and that its ideal creed which supports a small group approach are adhered to. What we find is that reality is often different, with individual facilitators condensing their PBL programmes to incorporate a modified PBL approach with this personalized approach often taking strength away from the original conceptions of PBL. What we suggest here is that these circumstances constitute a conundrum.
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 th...... problems on accurate air/fuel ratio control of a spark ignition (SI) engine....... 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......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...
An allometric scaling relation based on logistic growth of cities
Chen, Yanguang
2013-01-01
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 prop...
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
Enabling High Performance Large Scale Dense Problems through KBLAS
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.
Directory of Open Access Journals (Sweden)
Hua Luo
2012-01-01
Full Text Available Let be a time scale with 0,T∈. We give a global description of the branches of positive solutions to the nonlinear boundary value problem of second-order dynamic equation on a time scale , uΔΔ(t+f(t,uσ(t=0, t∈[0,T], u(0=u(σ2(T=0, which is not necessarily linearizable. Our approaches are based on topological degree theory and global bifurcation techniques.
Schettino, Carmel
2016-01-01
One recommendation for encouraging young women and other underrepresented students in their mathematical studies is to find instructional methods, such as problem-based learning (PBL), that allow them to feel included in the learning process. Using a more relationally centered pedagogy along with more inclusive instructional methods may be a way…
Prospective measurement of a problem-based learning course sequence.
Dolder, Christian R; Olin, Jacqueline L; Alston, Gregory L
2012-11-12
To measure the effect, over time, of a 2-year problem-based learning (PBL) sequence on the skills, knowledge, and abilities it was designed to develop and enhance. At the start of each PBL semester, students were provided a "work sample" case with a main medical issue not previously covered in the curriculum. A standardized form containing 6 sections (hypotheses, learning issues to investigate, how hypotheses ruled in/out, primary-problem identification, plan, and goals of plan) was completed for each case. To rate student performance, investigators used a standardized form with 5-point Likert scale. Sixty-seven students who completed 4 assessments were included in data analyses. Scores significantly improved for each semester compared with baseline. Minimal significant differences were observed among semesters 2, 3, and 4. The 2-year PBL sequence improved students' performance compared with baseline, but the performance ceiling observed in our study requires further investigation.
Existence Results for Higher-Order Boundary Value Problems on Time Scales
Sang Yanbin; Liu Jian
2009-01-01
By using the fixed-point index theorem, we consider the existence of positive solutions for the following nonlinear higher-order four-point singular boundary value problem on time scales , ; , ; , ; , , where , , , , , , , and is rd-continuous.
Zero-order Approximation of Three-time Scale Singular Linear-quadratic Optimal Control Problem
National Research Council Canada - National Science Library
Kalashnikova, M. A
2015-01-01
This paper is devoted to the construction of a zero-order approximation of the solution of a three-time scale singular perturbed linear-quadratic optimal control problem with the help of the direct scheme method...
Case Problems for Problem-Based Pedagogical Approaches: A Comparative Analysis
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,…
Scaling Professional Problems of Teachers in Turkey with Paired Comparison Method
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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.
Computer-Based Assessment of Problem Solving.
Baker, E. L.; Mayer, R. E.
1999-01-01
Examines the components required to assess student problem solving in technology environments. Discusses the purposes of testing, provides an example demonstrating the difference between retention and transfer, defines and analyzes problem solving, and explores techniques and standards for measuring the quality of student understanding. Contains…
Information filtering via a scaling-based function.
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.
Alcohol Use Problem Severity and Problem Behavior Engagement among School-Based Youths in Minnesota
Mancha, Brent E.; Rojas-Neese, Vanessa C.; Latimer, William W.
2010-01-01
This study created an alcohol use problem severity taxonomy and examined its association to engagement in other problem behaviors. Minnesota youths were categorized based on their frequency of alcohol use and DSM-IV alcohol abuse and dependence criteria. Greater alcohol use problem severity was generally associated with higher prevalence of…
Effectiveness of problem-based learning among student nurses: A ...
African Journals Online (AJOL)
In nursing, problem- based learning has been used very sparingly especially in developing countries such as South Africa. 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 ...
Incorporating Problem-Based Learning in Physical Education Teacher Education
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…
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....
Energy Technology Data Exchange (ETDEWEB)
Henson, V E
2003-02-06
The purpose of this research project was to investigate, design, and implement new algebraic multigrid (AMG) algorithms to enable the effective use of AMG in large-scale multiphysics simulation codes. These problems are extremely large; storage requirements and excessive run-time make direct solvers infeasible. The problems are highly ill-conditioned, so that existing iterative solvers either fail or converge very slowly. While existing AMG algorithms have been shown to be robust and stable for a large class of problems, there are certain problems of great interest to the Laboratory for which no effective algorithm existed prior to this research.
Petersen, Isaac T; Lindhiem, Oliver; LeBeau, Brandon; Bates, John E; Pettit, Gregory S; Lansford, Jennifer E; Dodge, Kenneth A
2017-11-20
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) 2017 APA, all rights reserved).
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.
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.
H.G. Schmidt (Henk); L. Vermeulen (Lyanda); H.T. van der Molen (Henk)
2006-01-01
textabstractBACKGROUND: Problem-based learning (PBL) as an approach to the instruction of medical students has attracted much attention in recent years. However, its effect on the performance of its graduates is the subject of considerable debate. This article presents data from a large-scale study
Yoshioka, Toshimasa; Suganuma, Taiyo; Tang, Ann C; Matsushita, Susumu; Manno, Sumie; Kozu, Tadahiko
2005-01-01
Adaptation to problem-based learning (PBL) is a difficult process for high school graduates who are not used to self-directed learning, especially in the freshmen year of medical school. The difficulty includes finding problems from a given case. Evaluate the effect of an intervention to facilitate case-based problem finding among medical school freshmen undergoing a PBL tutorial. Medical school freshmen in 2000 (nonintervened group) and 2001 (intervened group) participated in the study. The intervened group received the modified problem-based program by (a) having briefings on the importance of problem finding, (b) encouragement by the tutors in problem finding, and (c) reinforcement using a self-assessment sheet. At the end of the year, the ability of students to extract problems from a short case was evaluated and compared with the nonintervened students. The intervened group extracted a significantly greater number of problems than the nonintervened group. When extracted problems were categorized, the intervened group was able to generate more questions in a greater number of specified categories. Interventions to foster problem finding significantly facilitated acquisition of problem extraction skills among young medical students.
An allometric scaling relation based on logistic growth of cities
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.
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.
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.
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
A deﬁcit scaling algorithm for the minimum ﬂow problem
Indian Academy of Sciences (India)
In this paper, we develop a new preﬂow algorithm for the minimum ﬂow problem, called deﬁcit scaling algorithm. This is a special implementation of the generic preﬂow algorithm for the minimum ﬂow problem developed by Ciurea and Ciupală earlier. The bottleneck operation in the generic preﬂow algorithm is the number ...
Facilitating Problem Framing in Project-Based Learning
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…
Problem Based Learning: Application to Technology Education in Three Countries
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…
Magnitude-based scaling of tsunami propagation
Simanjuntak, M. Arthur; Greenslade, Diana J. M.
2011-07-01
Most current operational tsunami prediction systems are based upon databases of precomputed tsunami scenarios, where some form of linear scaling is applied to the precomputed model runs in order to represent specific earthquake magnitudes. This can introduce errors due to assumptions made about the rupture width and possible effects on dispersion. In this paper, we perform a series of numerical experiments on uniform depth domains, using the Method of Splitting Tsunamis (MOST) model, and develop estimates of the maximum error that an assumed discrepancy in the width of a rupture will produce in the resulting field of maximum tsunami amplitude. This estimate was produced from fitting the decay of maximum amplitude with normalized distance for various resolutions of the source widths to the grid size, resulting in a simple power law whose coefficients effectively vary with wavelength resolution. This provides a quantification of the effect that linear scaling of precomputed scenarios will have on forecasts of tsunami amplitude. This estimate of scaling bias is investigated in relation to the scenario database that is currently in use within the Joint Australian Tsunami Warning Centre.
An Investigation of Wavelet Bases for Grid-Based Multi-Scale Simulations Final Report
Energy Technology Data Exchange (ETDEWEB)
Baty, R.S.; Burns, S.P.; Christon, M.A.; Roach, D.W.; Trucano, T.G.; Voth, T.E.; Weatherby, J.R.; Womble, D.E.
1998-11-01
The research summarized in this report is the result of a two-year effort that has focused on evaluating the viability of wavelet bases for the solution of partial differential equations. The primary objective for this work has been to establish a foundation for hierarchical/wavelet simulation methods based upon numerical performance, computational efficiency, and the ability to exploit the hierarchical adaptive nature of wavelets. This work has demonstrated that hierarchical bases can be effective for problems with a dominant elliptic character. However, the strict enforcement of orthogonality was found to be less desirable than weaker semi-orthogonality or bi-orthogonality for solving partial differential equations. This conclusion has led to the development of a multi-scale linear finite element based on a hierarchical change of basis. The reproducing kernel particle method has been found to yield extremely accurate phase characteristics for hyperbolic problems while providing a convenient framework for multi-scale analyses.
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...
Habtu, Solomon; Ludi, Eva; Jamin, Jean Yves; Oates, Naomi; Fissahaye Yohannes, Degol
2014-05-01
Practicing various innovations pertinent to irrigated farming at local field scale is instrumental to increase productivity and yield for small holder farmers in Africa. However the translation of innovations from local scale to the scale of a jointly operated irrigation scheme is far from trivial. It requires insight on the drivers for adoption of local innovations within the wider farmer communities. Participatory methods are expected to improve not only the acceptance of locally developed innovations within the wider farmer communities, but to allow also an estimation to which extend changes will occur within the entire irrigation scheme. On such a base, more realistic scenarios of future water productivity within an irrigation scheme, which is operated by small holder farmers, can be estimated. Initial participatory problem and innovation appraisal was conducted in Gumselassa small scale irrigation scheme, Ethiopia, from Feb 27 to March 3, 2012 as part of the EAU4FOOD project funded by EC. The objective was to identify and appraise problems which hinder sustainable water management to enhance production and productivity and to identify future research strategies. Workshops were conducted both at local (Community of Practices) and regional (Learning Practice Alliance) level. At local levels, intensive collaboration with farmers using participatory methods produced problem trees and a "Photo Safari" documented a range of problems that negatively impact on productive irrigated farming. A range of participatory methods were also used to identify local innovations. At regional level a Learning Platform was established that includes a wide range of stakeholders (technical experts from various government ministries, policy makers, farmers, extension agents, researchers). This stakeholder group did a range of exercise as well to identify major problems related to irrigated smallholder farming and already identified innovations. Both groups identified similar problems
Facilitating Problem Framing in Project-Based Learning
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 how teachers supported students in taking ownership over the framing of problems in a charter school that serves students who have been underserved b...
Advantages of video trigger in problem-based learning.
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.
CFMDS: CUDA-based fast multidimensional scaling for genome-scale data.
Park, Sungin; Shin, Soo-Yong; Hwang, Kyu-Baek
2012-01-01
Multidimensional scaling (MDS) is a widely used approach to dimensionality reduction. It has been applied to feature selection and visualization in various areas. Among diverse MDS methods, the classical MDS is a simple and theoretically sound solution for projecting data objects onto a low dimensional space while preserving the original distances among them as much as possible. However, it is not trivial to apply it to genome-scale data (e.g., microarray gene expression profiles) on regular desktop computers, because of its high computational complexity. We implemented a highly-efficient software application, called CFMDS (CUDA-based Fast MultiDimensional Scaling), which produces an approximate solution of the classical MDS based on CUDA (compute unified device architecture) and the divide-and-conquer principle. CUDA is a parallel computing architecture exploiting the power of the GPU (graphics processing unit). The principle of divide-and-conquer was adopted for circumventing the small memory problem of usual graphics cards. Our application software has been tested on various benchmark datasets including microarrays and compared with the classical MDS algorithms implemented using C# and MATLAB. In our experiments, CFMDS was more than a hundred times faster for large data than such general solutions. Regarding the quality of dimensionality reduction, our approximate solutions were as good as those from the general solutions, as the Pearson's correlation coefficients between them were larger than 0.9. CFMDS is an expeditious solution for the data dimensionality reduction problem. It is especially useful for efficient processing of genome-scale data consisting of several thousands of objects in several minutes.
Physically based landslide warning at regional scale
Canli, Ekrem; Mergili, Martin; Glade, Thomas
2017-04-01
Albeit advancements in the past within the field of geotechnical engineering have led to an increasing in situ damage control in many parts of the world, heavy rainstorms still cause severe damage by triggering landslides. Landslides are usually restricted to the local scale when taking into consideration single events, however, they often tend to occur spatially abundant which makes them a regional phenomenon. This makes the necessity of regional-scale early warning systems (EWS) indispensable. When dealing with landslide EWS, it is impossible to cover all potential early warning situations. Although the calculation of rainfall thresholds is the most common approach for assessing regional landslide early warning, they only represent a simplification of the physical processes involved. In most cases, indeed, there is more than just this one causative factor involved. Here, we present an early prototype for a regional, physically based landslide EWS driven by real-time spatio-temporal rainfall data. Instead of assuming uniform rainfall over a certain area, an automated geostatistical approach is suggested which allows approximating real-time spatially distributed, hourly rainfall predictions based on gauged rainfall data available on the internet. The methodology presented in this study is especially suitable for the implementation in warning systems that contain predefined thresholds and for landslides related to a progressive increase of soil saturation and/or a rising groundwater table. The transient rainfall infiltration and grid-based slope stability (TRIGRS) model is used in a modified way to compute transient pore-pressure changes and associated changes in the factor of safety due to rainfall infiltration. The geotechnical properties involved are probabilistically integrated within certain predefined ranges to account for the inherent spatial uncertainties. The result is an automatically generated probability of failure raster map that is updated hourly based
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 /phosphonates and polyacrylates were effective in reducing and controlling the scale deposit problems. Institution of these measures led to a cleaner paper machine that required far fewer boil outs than before. In addition, productivity improved and the fisheye defects...
Large scale inverse problems computational methods and applications in the earth sciences
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.
Solution Matching for a Second Order Boundary Value Problem on Time Scales
Directory of Open Access Journals (Sweden)
Aprillya Lanz
2012-01-01
Full Text Available Let be a time scale such that <;,∈. We will show the existence and uniqueness of solutions for the second-order boundary value problem ΔΔ(=(,(,Δ(,∈[,],(=,(=, by matching a solution of the first equation satisfying boundary conditions on [,] with a solution of the first equation satisfying boundary conditions on [,], where ∈(,.
Problems in setting up an executing large-scale psychiatric epidemiological studies.
Offord, D R; Boyle, M H
1986-01-01
This paper focuses on problems that can be encountered in conceptualizing, executing and writing up large-scale psychiatric epidemiological studies. It makes no attempt to cover fundamental issues of design and analysis, rather it centers on problems associated with projects of considerable size. In the conceptual area, it discusses the prerequisites to be considered before deciding to launch such a study. It notes the administrative and scientific uses of epidemiological studies and considers the strengths and weaknesses of large-scale studies to address those concerns. Issues in carrying out such studies are discussed including decisions about study design, sampling method and instrumentation. All are dependent on the central purpose of the study but trade-offs between feasibility and scientific rigor are always present. Data collection and analysis problems highlighted in large-scale studies are examined. They include the difficulty, in the former, of adequately motivating and supervising field personnel and, in the latter, of dealing with problems that accompany missing data and complicated sampling strategies. Potential problems in data access and use and writing up the results are seen as arising from the presence of a large investigative team with diverse interests. Lastly, the comparative worth of these studies is considered.
Cross-cultural adaptation and validation to Brazil of the Obesity-related Problems Scale.
Brasil, Andreia Mara Brolezzi; Brasil, Fábio; Maurício, Angélica Aparecida; Vilela, Regina Maria
2017-01-01
To validate a reliable version of the Obesity-related Problems Scale in Portuguese to use it in Brazil. The Obesity-related Problems Scale was translated and transculturally adapted. Later it was simultaneously self-applied with a 12-item version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), to 50 obese patients and 50 non-obese individuals, and applied again to half of them after 14 days. The Obesity-related Problems scale was able to differentiate obese from non-obese individuals with higher accuracy than WHODAS 2.0, correlating with this scale and with body mass index. The factor analysis determined a two-dimensional structure, which was confirmed with χ2/df=1.81, SRMR=0.05, and CFI=0.97. The general a coefficient was 0.90 and the inter-item intra-class correlation, in the reapplication, ranged from 0.75 to 0.87. The scale proved to be valid and reliable for use in the Brazilian population, without the need to exclude items.
What Is the Problem in Problem-Based Learning in Higher Education Mathematics
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…
Incorporating Problem-Based Experiential Teaching in the Agricultural Curriculum.
Salvador, R. J.; And Others
1995-01-01
A forestry and agronomy course at Iowa State University incorporates problem-based team projects on real-world situations as a means of providing students with integrative and meaningful experiential learning. Student evaluations of these courses indicate that students recognize and appreciate the integrative nature of the problem-based team…
PROBLEM-BASED LEARNING IN CLINICAL CLERKSHIP - THE ...
African Journals Online (AJOL)
ASME Medical Education Booklet No. 23 Essentials of problem- based learning. Med EdIU 1989; 23: 539-558. 6. Schwartz RW, Donnelly MB, Nash PP, Young B. The development of clinical cognitive skills in a problem-based learning surgery clerkship. Acad Med 1992; 67: 694-696. 7. Schwartz RW, Burgett lE, Blue AY, ...
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....
An Integrated, Problem-Based Learning Material: The "Satellite" Module
Selcuk, Gamze Sezgin; Emiroglu, Handan Byacioglu; Tarakci, Mehmet; Ozel, Mustafa
2011-01-01
The purpose of this study is to introduce a problem-based learning material, the Satellite Module, that has integrated some of the subjects included in the disciplines of physics and mathematics at an introductory level in undergraduate education. The reason why this modular and problem-based material has been developed is to enable students to…
[Communication problems in evidence-based medicine].
Sachs, Lisbeth
2002-02-21
From a humanistic, social scientific perspective, the most complex task in evidence-based medicine lies in the communication of specialized medical knowledge to non-professionals. Information is never simply the neutral transmission of facts, not even when dealing with scientific knowledge and research. It is always interpreted and evaluated from a particular perspective in a specific context. That information can be neutral is thus a myth. In all medical consultations the process of communication is not just a matter of transmitting information from one who knows to one who does not. Knowledge created and formulated in a scientific context is thus recontextualised first in a clinical situation and then as an interpreted version in people's real lives. Furthermore there are difficulties when practice must be based on current research, in a situation in which no prior clinical experience exists and in which results are interpreted and used regardless of the relative certainty of current evidence.
Constraint-based scheduling applying constraint programming to scheduling problems
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...
A New Likert Scale Based on Fuzzy Sets Theory
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…
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.
Bringing nature-based solutions to scale
Jongman, Brenden; Lange, Glenn-Marie; Balog, Simone; van Wesenbeeck, Bregje
2017-04-01
Coastal communities in developing countries are highly exposed and vulnerable to coastal flood risk, and are likely to suffer from climate change induced changes in risk. Over the last decade, strong evidence has surfaced that nature-based solutions or ecosystem-based approaches are efficient and effective alternatives for flood risk reduction and climate change adaptation. In developing countries, numerous projects have therefore been implemented, often driven by international donors and NGOs. Some of these projects have been successful in reducing risk while improving environmental and socioeconomic conditions. However, the feasibility assessment, design and implementation of nature-based solutions is a multifaceted process, which needs to be well-understood before such solutions can be effectively implemented as an addition or alternative to grey infrastructure. This process has not always been followed. As a result, many projects have failed to deliver positive outcomes. The international community therefore has a challenge in bringing nature-based solutions to scale in an effective way. In this presentation, we will present best practice guidelines on nature-based solution implementation that are currently being discussed by the international community. Furthermore, we will present the alpha version of a new web platform being developed by the World Bank that will serve as a much-needed central repository for project information on nature-based solutions, and that will host actionable implementation guidelines. The presentation will also serve as an invitation to the scientific community to share their experience and lessons learned, and contribute to the outlining of best practice guidance.
Enhancement of a model for Large-scale Airline Network Planning Problems
Kölker, K.; Lopes dos Santos, B.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
Random Group Problem-Based Learning in Engineering Dynamics
Fleischfresser, Luciano
2014-01-01
Dynamics problem solving is highly specific to the problem at hand and to develop the general mind framework to become an effective problem solver requires ingenuity and creativity on top of a solid grounding on theoretical and conceptual knowledge. A blended approach with prototype demo, problem-based learning, and an opinion questionnaire was used during first semester of 2013. Students working in randomly selected teams had to interact with classmates while solving a randomly selected problem. The approach helps improve awareness of what is important to learn in this class while reducing grading load. It also provides a more rewarding contact time for both pupils and instructor.
Asian Monsoon Variations on Orbital-Millennial Scales and the `100 Thousand Year Problems'
Cheng, H.; Edwards, R. L.; Sinha, A.; Spoetl, C.; Yi, L.; Li, X.; Kathayat, G.
2016-12-01
Speleothem oxygen isotope records from China characterize changes in the Asian monsoon and global climate. We have now extended our Chinese record to cover the full uranium/thorium dating range: the last 640,000 years. The record's length, temporal precision, and correlations with both ice core and marine records allow us to further probe the enduring `100 ka problem'—i.e., why do large-amplitude ice age cycles and changes in eccentricity share common spectral power although the latter generates negligible change in insolation? Based on our record's timing, the ice age terminations are separated by 4 or 5 precession cycles, supporting the idea that the 100 ka ice age cycle is an average of discrete numbers of precession cycles. Furthermore, the suborbital component of monsoon rainfall variability exhibits power in precession and obliquity bands, and is nearly anti-phased with June 21 boreal insolation. These observations indicate that insolation, in part, paces the occurrence of millennial-scale events, including those associated with ice age terminations and `unfinished terminations'. In the East Asian summer monsoon (EASM) domain, Loess magnetic susceptibility records from the Chinese Loess Plateau (CLP) show that the EASM is dominated by 100 ka cycles, which is in contrast to the conventional notion that insolation changes caused by the 20 ka precession cycle are the primary driver of summer monsoon. These observations present another paradox, which we dub here as the `Chinese 100 ka problem'. The existing and new speleothem records from both China and India reinforce the idea that precession, rather than glacial-interglacial, cycles, is the dominant driver of both EASM and Indian summer monsoon variations. The lack of precession signals in the loess records from the CLP might stem partially from its unique climatological settings and complex nature of loess magnetic susceptibility proxy.
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.
Problem-based learning in internal medicine: virtual patients or paper-based problems?
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.
Efficient numerical methods for the large-scale, parallel solution of elastoplastic contact problems
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.
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
Energy Technology Data Exchange (ETDEWEB)
Ng, Jonathan; Huang, Yi-Min; Hakim, Ammar; Bhattacharjee, A. [Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Stanier, Adam; Daughton, William [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Wang, Liang; Germaschewski, Kai [Space Science Center and Physics Department, University of New Hampshire, Durham, New Hampshire 03824 (United States)
2015-11-15
As modeling of collisionless magnetic reconnection in most space plasmas with realistic parameters is beyond the capability of today's simulations, due to the separation between global and kinetic length scales, it is important to establish scaling relations in model problems so as to extrapolate to realistic scales. Recently, large scale particle-in-cell simulations of island coalescence have shown that the time averaged reconnection rate decreases with system size, while fluid systems at such large scales in the Hall regime have not been studied. Here, we perform the complementary resistive magnetohydrodynamic (MHD), Hall MHD, and two fluid simulations using a ten-moment model with the same geometry. In contrast to the standard Harris sheet reconnection problem, Hall MHD is insufficient to capture the physics of the reconnection region. Additionally, motivated by the results of a recent set of hybrid simulations which show the importance of ion kinetics in this geometry, we evaluate the efficacy of the ten-moment model in reproducing such results.
FDTD method for laser absorption in metals for large scale problems.
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.
Speak Out: Dancing into Problem-Based Learning
Parrish, Mila Dr.
2007-01-01
In recent years, Problem Based Learning (PBL) has been applied in medical and psychological areas of professional education. The PBL approach requires students to move past traditional choreographic methods toward making dances informed by real-world issues. In PBL, students work cooperatively to solve complex problems. Rather than being presented technical dance steps, they develop critical thinking abilities, acquire problem-solving skills, and communication dexterity. PBL can be effectivel...
A Reduced Basis Framework: Application to large scale non-linear multi-physics problems
Directory of Open Access Journals (Sweden)
Daversin C.
2013-12-01
Full Text Available In this paper we present applications of the reduced basis method (RBM to large-scale non-linear multi-physics problems. We first describe the mathematical framework in place and in particular the Empirical Interpolation Method (EIM to recover an affine decomposition and then we propose an implementation using the open-source library Feel++ which provides both the reduced basis and finite element layers. Large scale numerical examples are shown and are connected to real industrial applications arising from the High Field Resistive Magnets development at the Laboratoire National des Champs Magnétiques Intenses.
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
Shek, Daniel T. L.; Ma, Cecilia Man-Sze
2009-01-01
The Chinese Perceived Causes of Poverty Scale (CPCPS) was constructed to assess Chinese people's beliefs about poverty. Four categories of explanations of poverty are covered in this scale: personal problems of poor people, lack of opportunities to escape from poverty, exploitation of poor people, and bad fate. Based on the responses of 1,519…
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......The background for this article is the big changes we have experienced since the idea of the problem based learning model was conceived at Aalborg University in the beginning of the 1970s. Assuming that no teaching model is context free, the challenge is to confront the basics of the problem...
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.
Information Filtering via a Scaling-Based Function
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. PMID:23696829
Process competencies in a problem and project based learning environment
Du, Xiangyun; Kolmos, Anette
2006-01-01
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 competencies. Consequently, engineering education is facing challenges regarding how to facilitate students with scientific-technological competencies as well as process competencies. Problem based...
Teaching Evidence-based Medicine Using Literature for Problem Solving.
Mottonen, Merja; Tapanainen, Paivi; Nuutinen, Matti; Rantala, Heikki; Vainionpaa, Leena; Uhari, Matti
2001-01-01
Evidence-based medicine--the process of using research findings systematically as the basis for clinical decisions--can be taught using problem-solving teaching methods. Evaluates whether it was possible to motivate students to use the original literature by giving them selected patient problems to solve. (Author/ASK)
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....
Student Motivation in Response to Problem-Based Learning
Fukuzawa, Sherry; Boyd, Cleo; Cahn, Joel
2017-01-01
Problem-based learning (PBL) is a self-directed learning strategy where students work collaboratively in small groups to investigate open-ended relatable case scenarios. Students develop transferable skills that can be applied across disciplines, such as collaboration, problem-solving, and critical thinking. Despite extensive research on…
Problem-Based Learning in Formal and Informal Learning Environments
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…
Speak Out: Dancing into Problem-Based Learning
Parrish, Mila
2007-01-01
In recent years, Problem Based Learning (PBL) has been applied in medical and psychological areas of professional education. The PBL approach requires students to move past traditional choreographic methods toward making dances informed by real-world issues. In PBL, students work cooperatively to solve complex problems. Rather than being presented…
Implementation of Problem Based Learning among Nursing Students
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…
Terminal value problems for first and second order nonlinear equations on time scales
Directory of Open Access Journals (Sweden)
Christopher C. Tisdell
2008-05-01
Full Text Available In this paper we examine "terminal" value problems for dynamic equations on time scales - that is, a dynamic equation whose solutions are asymptotic at infinity. We present a number of new theorems that guarantee the existence and uniqueness of solutions, as well as some comparison-type results. The methods we employ feature dynamic inequalities, weighted norms, and fixed-point theory.
Problem-Based Learning in Engineering Ethics Courses
National Research Council Canada - National Science Library
Kirkman, Robert
2017-01-01
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...
Creating Problem-Based Leadership Learning across the Curriculum
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.
Physical Assessment Experience in a Problem-Based Learning Course
Riche, Daniel M.; Stover, Kayla R.
2011-01-01
Objective. To evaluate the impact of a physical-assessment learning experience implemented in the problem-based learning (PBL) format of the third year of a doctor of pharmacy (PharmD) program. Design. Students enrolled in a PBL course completed survey instruments to measure knowledge and confidence before and after participating in the learning experience. A simulation stethoscope was used to teach students abnormal pulmonary and cardiovascular sounds in 1-hour sessions for each of 12 PBL groups. Assessment. The 92 students enrolled in the PBL course completed pre- and post-experience survey instruments. Students’ scores on knowledge questions increased significantly (p < 0.0001) from 40.4% ± 11.4% at baseline to 62.5% ± 13.7% and 63.1 ± 11.6%, respectively, on the 2 sets of post-experience questions. Students scored a median of 3 or 4 on a 5-point Likert scale after a learning experience on questions measuring confidence. Conclusion. Use of a simulation stethoscope in a physical-assessment learning experience increased pharmacy students’ knowledge in performing pulmonary and cardiovascular assessment techniques. PMID:22102746
From Cases to Projects in Problem-Based Medical Education
Stentoft, Diana; Duroux, Meg; Fink, Trine; Emmersen, Jeppe
2014-01-01
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…
Teaching introductory thermal physics through problem based learning
Tracey, Rebecca
2005-01-01
The development and delivery of an introductory thermal physics module taught through Problem Based Learning (PBL) in a lecture-based curriculum is reported on. The development and implementation of the module is illustrated through discussion of the problems and students responses. The PBL methodology is compared with traditional lecture style teaching and the educational theories that the methodologies stem from are discussed. Examples of how PBL has been used to teach physics, along wi...
Network capacity with probit-based stochastic user equilibrium problem.
Lu, Lili; Wang, Jian; Zheng, Pengjun; Wang, Wei
2017-01-01
Among different stochastic user equilibrium (SUE) traffic assignment models, the Logit-based stochastic user equilibrium (SUE) is extensively investigated by researchers. It is constantly formulated as the low-level problem to describe the drivers' route choice behavior in bi-level problems such as network design, toll optimization et al. The Probit-based SUE model receives far less attention compared with Logit-based model albeit the assignment result is more consistent with drivers' behavior. It is well-known that due to the identical and irrelevant alternative (IIA) assumption, the Logit-based SUE model is incapable to deal with route overlapping problem and cannot account for perception variance with respect to trips. This paper aims to explore the network capacity with Probit-based traffic assignment model and investigate the differences of it is with Logit-based SUE traffic assignment models. The network capacity is formulated as a bi-level programming where the up-level program is to maximize the network capacity through optimizing input parameters (O-D multiplies and signal splits) while the low-level program is the Logit-based or Probit-based SUE problem formulated to model the drivers' route choice. A heuristic algorithm based on sensitivity analysis of SUE problem is detailed presented to solve the proposed bi-level program. Three numerical example networks are used to discuss the differences of network capacity between Logit-based SUE constraint and Probit-based SUE constraint. This study finds that while the network capacity show different results between Probit-based SUE and Logit-based SUE constraints, the variation pattern of network capacity with respect to increased level of travelers' information for general network under the two type of SUE problems is the same, and with certain level of travelers' information, both of them can achieve the same maximum network capacity.
[Spanish adaptation of the "Mobile Phone Problem Use Scale" for adolescent population].
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.
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
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...... 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......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...
Adiguzel, Tufan; Akpinar, Yavuz
2004-01-01
Instructional resources that employ multiple representations have become commonplace in mathematics classrooms. This study will present computer software, LaborScale which was designed to improve seventh grade students' word problem-solving skills through computer-based multiple representations including graphic, symbolic, and audio…
Big Graphics and Little Screens: Model-Based Design of Large Scale Information Displays
1992-06-01
The design of large scale information displays is addressed. Problems with traditional approaches to display design are discussed. It is argued that...the evolving nature of humans’ roles in complex systems will exacerbate these problems. A model-based framework for display design is proposed...involving system models, task models, and humans’ models of systems and tasks. This framework provide a basis for exploring three types of display design problems
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.
Assessment of goals in problem-based learning.
Özbıçakçı, Şeyda; Bilik, Özlem; İntepeler, Şeyda Seren
2012-11-01
Assessing the learning goals set by faculty is an important part of problem-based learning (PBL). Students also develop individual and group goals during module tutorials. They choose learning activities and create a framework for their self-directed study in order to achieve these goals. This investigation analyzes perceptions of the depth of understanding that students acquire. The effects of setting learning goals by faculty and by students themselves are examined, and we explore differences within groups and within the different years in the program. Nursing students responded to a questionnaire indicating how well they thought they had understood new material, according to both the goals preset by the faculty and those developed by the students themselves. A five-point Likert scale was used for this. The findings indicate no significant difference between tutors' and students' evaluations of student level of understanding within the different years of the program. Students and tutors in all three years indicated that they achieved adequate or good understanding of learning goals. (Students: First year: 91.6%, second year: 76.5%, third year: 90.1%; Tutors: First year: 76.8%, second year: 65.7%, third year: 89.1%) These findings are useful for evaluation of PBL outcomes for curriculum committees. Based on these research results, our faculty curriculum committee has decided to give the students a list of faculty generated learning goals at the end of every curriculum module. The students then compare these with their own self-directed goals in feedback sessions with faculty members. These feedback sessions have been very popular with students. Copyright © 2012 Elsevier Ltd. All rights reserved.
Problem-based learning on quantitative analytical chemistry course
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.
Fast and high precision algorithms for optimization in large-scale genomic problems.
Mester, D I; Ronin, Y I; Nevo, E; Korol, A B
2004-10-01
There are several very difficult problems related to genetic or genomic analysis that belong to the field of discrete optimization in a set of all possible orders. With n elements (points, markers, clones, sequences, etc.), the number of all possible orders is n!/2 and only one of these is considered to be the true order. A classical formulation of a similar mathematical problem is the well-known traveling salesperson problem model (TSP). Genetic analogues of this problem include: ordering in multilocus genetic mapping, evolutionary tree reconstruction, building physical maps (contig assembling for overlapping clones and radiation hybrid mapping), and others. A novel, fast and reliable hybrid algorithm based on evolution strategy and guided local search discrete optimization was developed for TSP formulation of the multilocus mapping problems. High performance and high precision of the employed algorithm named guided evolution strategy (GES) allows verification of the obtained multilocus orders based on different computing-intensive approaches (e.g., bootstrap or jackknife) for detection and removing unreliable marker loci, hence, stabilizing the resulting paths. The efficiency of the proposed algorithm is demonstrated on standard TSP problems and on simulated data of multilocus genetic maps up to 1000 points per linkage group.
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.
Vision-based stereo ranging as an optimal control problem
Menon, P. K. A.; Sridhar, B.; Chatterji, G. B.
1992-01-01
The recent interest in the use of machine vision for flight vehicle guidance is motivated by the need to automate the nap-of-the-earth flight regime of helicopters. Vision-based stereo ranging problem is cast as an optimal control problem in this paper. A quadratic performance index consisting of the integral of the error between observed image irradiances and those predicted by a Pade approximation of the correspondence hypothesis is then used to define an optimization problem. The necessary conditions for optimality yield a set of linear two-point boundary-value problems. These two-point boundary-value problems are solved in feedback form using a version of the backward sweep method. Application of the ranging algorithm is illustrated using a laboratory image pair.
Primer on clinical acid-base problem solving.
Whittier, William L; Rutecki, Gregory W
2004-03-01
Acid-base problem solving has been an integral part of medical practice in recent generations. Diseases discovered in the last 30-plus years, for example, Bartter syndrome and Gitelman syndrome, D-lactic acidosis, and bulimia nervosa, can be diagnosed according to characteristic acid-base findings. Accuracy in acid-base problem solving is a direct result of a reproducible, systematic approach to arterial pH, partial pressure of carbon dioxide, bicarbonate concentration, and electrolytes. The 'Rules of Five' is one tool that enables clinicians to determine the cause of simple and complex disorders, even triple acid-base disturbances, with consistency. In addition, other electrolyte abnormalities that accompany acid-base disorders, such as hypokalemia, can be incorporated into algorithms that complement the Rules and contribute to efficient problem solving in a wide variety of diseases. Recently urine electrolytes have also assisted clinicians in further characterizing select disturbances. Acid-base patterns, in many ways, can serve as a 'common diagnostic pathway' shared by all subspecialties in medicine. From infectious disease (eg, lactic acidemia with highly active antiviral therapy therapy) through endocrinology (eg, Conn's syndrome, high urine chloride alkalemia) to the interface between primary care and psychiatry (eg, bulimia nervosa with multiple potential acid-base disturbances), acid-base problem solving is the key to unlocking otherwise unrelated diagnoses. Inasmuch as the Rules are clinical tools, they are applied throughout this monograph to diverse pathologic conditions typical in contemporary practice.
Travels towards Problem Based Learning in Medical Education (VPBL).
Bowdish, Bruce E.; Chauvin, Sheila W.; Kreisman, Norman; Britt, Mike
2003-01-01
Reports results of an investigation of the effectiveness of a prototype virtual problem-based learning (VPBL) exercise delivered via the World Wide Web to first year medical students. Compares the VPBL and a text-based version of the same exercise on students' achievement and examines instructional design issues including learner control and…
Problem-based learning as a facilitator of conceptual change
Loyens, Sofie M M; Jones, Suzanne H.; Mikkers, Jeroen; van Gog, Tamara
2015-01-01
We investigated whether problem-based learning (PBL) can foster conceptual change. Students were randomly assigned to a PBL, lecture-based, or self-study group, all receiving instruction about the topic of Newtonian laws. Conceptual change was measured from pre- to immediate post-test (directly
Connecting Problem-Based Practices with Educational Theory.
Gijselaers, Wim H.
1996-01-01
Three principles based on research in cognitive psychology explain the potential power of problem-based learning: (1) learning is a constructive, not a receptive process; (2) metacognition affects learning; and (3) social and contextual factors influence learning. These principles are more likely to be activated when specific teacher behaviors and…
Developing staff for the implementation of problem-based learning ...
African Journals Online (AJOL)
Educational transformation in higher education places new demands on academics, especially in terms of shifting from traditional methods of teaching and learning to the application of innovative methods. Whereas outcomes-based education leans towards a philosophy, problem-based learning (PBL) offers a structured ...
Problem-Based Learning and Civic Engagement in Undergraduate Education
Keegan, Louise C.; Losardo, Angela; McCullough, Kim C.
2017-01-01
Problem-based learning and civic engagement are complementary constructivist andragogical approaches that emphasize active learning by guiding students to develop their own understanding and knowledge of a topic through experience and reflection. By providing examples of clinical cases and community-based experiences, these approaches can enhance…
Analysis of an Assessment Method for Problem-Based Learning
Acar, B. Serpil
2004-01-01
The paper commences by briefly introducing the systems engineering programme, then focuses on the "systems" module, which requires the first-year students to undertake a number of "open-ended" projects. During the problem-based learning (PBL) based projects the students are expected to combine creativity and the knowledge they acquire during the…
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 ...
Problem-based leadership: nurturing managers during turbulent times
Gold, J
2010-01-01
Purpose – The paper explores problem-based learning (PBL) as a useful methodology in leadership development during turbulent times. It identifies several pertinent action points for managers to lead through problems while understanding their capacity to empower themselves and others to face challenges at work. Design/methodology/approach – Broad concepts of PBL are used to distil the characteristics of this methodology and how they might be applicable to leadership development. An actual case...
Nursing students' perceptions of effective problem-based learning tutors.
Matthew-Maich, Nancy; Martin, Lynn; Hammond, Cynthia; Palma, Amy; Pavkovic, Maria; Sheremet, Darlene; Roche, Carmen
2016-11-16
Aim To explore baccalaureate nursing students' perceptions of what makes an effective tutor in problem-based learning courses, and the influence of effective teaching on students' learning and experience. Method Students enrolled in all four years of a baccalaureate nursing programme completed online surveys (n=511) and participated in focus groups (n=19). Data were analysed and combined using content analysis. Findings The data were summarised using five themes, the '5 Ps' of effective teaching in problem-based learning. Nursing students perceived effective problem-based learning tutors to be prepared with knowledge and facilitation skills, person-centred, passionate, professional and able to prepare students for success in the nursing programme. Effective tutors adjusted their approaches to students throughout the four years of the nursing programme. Conclusion Effective teaching in problem-based learning is essential and has significant effects on nursing students' learning, motivation and experience. Important attributes, skills and strategies of effective problem-based learning tutors were identified and may be used to enhance teaching and plan professional development initiatives.
High scale parity invariance as a solution to the SUSY CP problem ...
Indian Academy of Sciences (India)
anism automatic in the theory. The minimal version of this theory also provides an explanation of ... cannot be rotated away by. *This talk is based on work done in collaboration with K S Babu and B Dutta. ... ¯Г. The low energy theory in this case is MSSM, but without the SUSY CP problem and with its parameters restricted ...
Mapping the MMPI-2-RF Specific Problems Scales Onto Extant Psychopathology Structures.
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.
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
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.
List-Based Simulated Annealing Algorithm for Traveling Salesman Problem.
Zhan, Shi-hua; Lin, Juan; Zhang, Ze-jun; Zhong, Yi-wen
2016-01-01
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.
UICEE Centre for Problem Based Learning (UCPBL) at Aalborg University
DEFF Research Database (Denmark)
Fink, Flemming Kobberøe; Enemark, Stig; Moesby, Egon
2002-01-01
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...... 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...
[Problem based learning from the perspective of tutors].
Navarro Hernández, Nancy; Illesca P, Mónica; Cabezas G, Mirtha
2009-02-01
Problem based learning is a student centered learning technique that develops deductive, constructive and reasoning capacities among the students. Teachers must adapt to this paradigm of constructing rather than transmitting knowledge. To interpret the importance of tutors in problem based learning during a module of Health research and management given to medical, nursing, physical therapy, midwifery, technology and nutrition students. Eight teachers that participated in a module using problem based learning accepted to participate in an in depth interview. The qualitative analysis of the textual information recorded, was performed using the ATLAS software. We identified 662 meaning units, grouped in 29 descriptive categories, with eight emerging meta categories. The sequential and cross-generated qualitative analysis generated four domains: competence among students, competence of teachers, student-centered learning and evaluation process. Multiprofessional problem based learning contributes to the development of generic competences among future health professionals, such as multidisciplinary work, critical capacity and social skills. Teachers must shelter the students in the context of their problems and social situation.
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.
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...
Problem based learning: an opportunity for theatre nurse education.
Tanner, J
1999-11-01
In my experience theatre nurses are always saying that student nurses just don't know enough anatomy, even with compulsory regular teaching of the subject in pre-registration nurse education. Boud and Feletti (1997) say anatomy and other subjects are forgotten because when they are taught students do not perceive their relevance. Problem based learning (PBL) seeks to overcome this difficulty by integrating theory and practice. This article will describe problem based learning and give an example of a scenario used in this educational process. The benefits of a PBL theatre nursing course and the implications for theatre nurse education will be discussed.
Spreadsheet Based Scaling Calculations and Membrane Performance
Energy Technology Data Exchange (ETDEWEB)
Wolfe, T D; Bourcier, W L; Speth, T F
2000-12-28
Many membrane element manufacturers provide a computer program to aid buyers in the use of their elements. However, to date there are few examples of fully integrated public domain software available for calculating reverse osmosis and nanofiltration system performance. The Total Flux and Scaling Program (TFSP), written for Excel 97 and above, provides designers and operators new tools to predict membrane system performance, including scaling and fouling parameters, for a wide variety of membrane system configurations and feedwaters. The TFSP development was funded under EPA contract 9C-R193-NTSX. It is freely downloadable at www.reverseosmosis.com/download/TFSP.zip. TFSP includes detailed calculations of reverse osmosis and nanofiltration system performance. Of special significance, the program provides scaling calculations for mineral species not normally addressed in commercial programs, including aluminum, iron, and phosphate species. In addition, ASTM calculations for common species such as calcium sulfate (CaSO{sub 4}{times}2H{sub 2}O), BaSO{sub 4}, SrSO{sub 4}, SiO{sub 2}, and LSI are also provided. Scaling calculations in commercial membrane design programs are normally limited to the common minerals and typically follow basic ASTM methods, which are for the most part graphical approaches adapted to curves. In TFSP, the scaling calculations for the less common minerals use subsets of the USGS PHREEQE and WATEQ4F databases and use the same general calculational approach as PHREEQE and WATEQ4F. The activities of ion complexes are calculated iteratively. Complexes that are unlikely to form in significant concentration were eliminated to simplify the calculations. The calculation provides the distribution of ions and ion complexes that is used to calculate an effective ion product ''Q.'' The effective ion product is then compared to temperature adjusted solubility products (Ksp's) of solids in order to calculate a Saturation Index (SI
The influence of online problem-based learning on teachers' professional practice and identity
Directory of Open Access Journals (Sweden)
Steve Wheeler
2005-12-01
Full Text Available In this paper we describe the design of a managed learning environment called MTutor, which is used to teach an online Masters Module for teachers. In describing the design of MTutor pedagogic issues of problem-based learning, situated cognition and ill-structured problems are discussed. MTutor presents teachers with complex real-life teaching problems, which they are required to solve online through collaboration with other teachers. In order to explore the influence of this online learning experience on the identity and practice of teachers, we present the results from a small-scale study in which six students were interviewed about their online experiences. We conclude that, within the sample, students' engagement with online problem-based learning within their community of practice positively influenced their professional practice styles, but that there is little evidence to suggest that online identity influences real-life practice.
Problem-based learning in photonics technology education
Massa, Nicholas M.; Dischino, Michele; Donnelly, Judith; Hanes, Fenna
2008-08-01
Problem-based learning (PBL) is an instructional approach in which students learn by actively and collaboratively solving authentic problems encountered in real-world situations. Research demonstrates that PBL improves students' learning and retention, motivation, critical thinking and problem-solving skills, and their ability to skillfully apply knowledge in new and novel situations - skills deemed critical for lifelong learning. In this paper, we present the Photon PBL project, a three-year National Science Foundation Advanced Technological Education (NSF-ATE) project aimed at developing, in partnership with photonics industry and university partners, a comprehensive series of multimedia PBL instructional materials and training for photonics technology educators from across the US and abroad. Results from first-year pilot testing of multimedia PBL instructional materials, problem development and implementation strategies are detailed.
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.
Schmidt, Henk G; Vermeulen, Lyanda; van der Molen, Henk T
2006-06-01
Problem-based learning (PBL) as an approach to the instruction of medical students has attracted much attention in recent years. However, its effect on the performance of its graduates is the subject of considerable debate. This article presents data from a large-scale study among graduates of a problem-based medical school and those of a conventional medical school to contribute to this discussion. To study the longterm effects of problem-based medical training on the professional competencies of graduates. A questionnaire was sent to all graduates since 1980 of a problem-based and a conventional medical school. Participants were requested to rate themselves on 18 professional competencies derived from the literature. The graduates of the PBL school scored higher on 14 of 18 professional competencies. Graduates of the problem-based school rated themselves as having much better interpersonal skills, better competencies in problem solving, self-directed learning and information gathering, and somewhat better task-supporting skills, such as the ability to work and plan efficiently. There were no sizeable differences with regard to general academic competencies, such as conducting research or writing a paper. Graduates from the conventional school rated themselves as having slightly more medical knowledge. The findings were shown to be valid and robust against possible response bias. The findings suggest that PBL not only affects the typical PBL-related competencies in the interpersonal and cognitive domains, but also the more general work-related skills that are deemed important for success in professional practice.
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.
Static micromixers based on large-scale industrial mixer geometry.
Bertsch, A; Heimgartner, S; Cousseau, P; Renaud, P
2001-09-01
Mixing liquids at the micro-scale is difficult because the low Reynolds numbers in microchannels and in microreactors prohibit the use of conventional mixing techniques based on mechanical actuators and induce turbulence. Static mixers can be used to solve this mixing problem. This paper presents micromixers with geometries very close to conventional large-scale static mixers used in the chemical and food-processing industry. Two kinds of geometries have been studied. The first type is composed of a series of stationary rigid elements that form intersecting channels to split, rearrange and combine component streams. The second type is composed of a series of short helix elements arranged in pairs, each pair comprised of a right-handed and left-handed element arranged alternately in a pipe. Micromixers of both types have been designed by CAD and manufactured with the integral microstereolithography process, a new microfabrication technique that allows the manufacturing of complex three-dimensional objects in polymers. The realized mixers have been tested experimentally. Numerical simulations of these micromixers using the computational fluid dynamics (CFD) program FLUENT are used to evaluate the mixing efficiency. With a low pressure drop and good mixing efficiency these truly three-dimensional micromixers can be used for mixing of reactants or liquids containing cells in many microTAS applications.
Hafiz, M.; Darhim; Dahlan, J. A.
2017-09-01
Mathematical resilience is very important thing in learning mathematics. It is a positive attitude in order to make student not easily give up in the face of adversity when solving mathematics problems through discussion and research about mathematics. The purpose of this study was to examine comparison of mathematical resilience among students receiving problem based learning model and the students who received guided discovery learning model. This research was conducted at one junior high school in Jakarta. The method was used in this study is quasi-experimental with 66 students as the samples. The instrument which was used in this research is mathematical resilience scale with 24 items of statements. The result of this research is mathematical resilience between the students who received problem based learning model is better than the students who received guided discovery learning model. According to this study result the authors presented some suggestions that: 1) problem based learning and guided discovery learning model can both develop mathematical resilience, but problem based learning is more recommended to use, 2) in order to achieve mathematical resilience better than this findings, it needs to do the next research that combine problem based learning with other treatment.
Process competencies in a problem and project based learning environment
DEFF Research Database (Denmark)
Du, Xiangyun; Kolmos, Anette
2006-01-01
competencies. Consequently, engineering education is facing challenges regarding how to facilitate students with scientific-technological competencies as well as process competencies. Problem based learning (PBL) as an educational model is regarded as an effective example regarding preparing students......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...... 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...
A Study on Teaching Gases to Prospective Primary Science Teachers Through Problem-Based Learning
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.
Ergül, Özgür
2011-11-01
Fast and accurate solutions of large-scale electromagnetics problems involving homogeneous dielectric objects are considered. Problems are formulated with the electric and magnetic current combined-field integral equation and discretized with the Rao-Wilton-Glisson functions. Solutions are performed iteratively by using the multilevel fast multipole algorithm (MLFMA). For the solution of large-scale problems discretized with millions of unknowns, MLFMA is parallelized on distributed-memory architectures using a rigorous technique, namely, the hierarchical partitioning strategy. Efficiency and accuracy of the developed implementation are demonstrated on very large problems involving as many as 100 million unknowns.
Validation of the Turkish Version of the Problem Areas in Diabetes Scale
Directory of Open Access Journals (Sweden)
Elisabeth M. J. Huis In ‘T Veld
2011-01-01
Full Text Available 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 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 satisfactory psychometric properties, however, the factorial structure was found to differ from factor solutions from other countries.
Automated Decomposition of Model-based Learning Problems
Williams, Brian C.; Millar, Bill
1996-01-01
A new generation of sensor rich, massively distributed autonomous systems is being developed that has the potential for unprecedented performance, such as smart buildings, reconfigurable factories, adaptive traffic systems and remote earth ecosystem monitoring. To achieve high performance these massive systems will need to accurately model themselves and their environment from sensor information. Accomplishing this on a grand scale requires automating the art of large-scale modeling. This paper presents a formalization of [\\em decompositional model-based learning (DML)], a method developed by observing a modeler's expertise at decomposing large scale model estimation tasks. The method exploits a striking analogy between learning and consistency-based diagnosis. Moriarty, an implementation of DML, has been applied to thermal modeling of a smart building, demonstrating a significant improvement in learning rate.
Designing Digital Problem Based Learning Tasks that Motivate Students
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…
Are marketing students in control in problem-based learning?
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
a comparison between a problem based and a conventional ...
African Journals Online (AJOL)
2010-07-07
Jul 7, 2010 ... define the needed range of practical skills, and should be presented in ways that encourage student-centred learning, allow indepth study in areas of particular interest, and provide them with insights into the scientific method and the discipline of research. The concept of Problem based learning (PBL).
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.
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...
ICT in Problem- and Project-based Learning
DEFF Research Database (Denmark)
Nielsen, Jørgen Lerche; Birch Andreasen, Lars
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...
Problem-Based Learning in the English Language Classroom
Othman, Normala; Shah, Mohamed Ismail Ahamad
2013-01-01
The purpose of this study was to investigate the effects of the problem-based learning approach (PBL) on students in language classes in two areas: course content and language development. The study was conducted on 128 students, grouped into the experimental and control groups, and employed an experimental research design. The syllabus, textbook,…
"Theory repositories" via the web for problem-based learning
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
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...
Cognitive Engagement in the Problem-Based Learning Classroom
Rotgans, Jerome I.; Schmidt, Henk G.
2011-01-01
The objective of the present study was to examine to what extent autonomy in problem-based learning (PBL) results in cognitive engagement with the topic at hand. To that end, a short self-report instrument was devised and validated. Moreover, it was examined how cognitive engagement develops as a function of the learning process and the extent to…
Cognitive engagement in the problem-based learning classroom
J.I. Rotgans (Jerome); H.G. Schmidt (Henk)
2011-01-01
textabstractThe objective of the present study was to examine to what extent autonomy in problem-based learning (PBL) results in cognitive engagement with the topic at hand. To that end, a short self-report instrument was devised and validated. Moreover, it was examined how cognitive engagement
Kriging based robust optimisation algorithm for minimax problems in electromagnetics
Directory of Open Access Journals (Sweden)
Li Yinjiang
2016-12-01
Full Text Available The paper discusses some of the recent advances in kriging based worst-case design optimisation and proposes a new two-stage approach to solve practical problems. The efficiency of the infill points allocation is improved significantly by adding an extra layer of optimisation enhanced by a validation process.
Kriging based robust optimisation algorithm for minimax problems in electromagnetics
Li, Yinjiang; Rotaru, Mihai; Sykulski, Jan
2016-01-01
The paper discusses some of the recent advances in kriging based worst-case design optimisation and proposes a new two-stage approach to solve practical problems. The efficiency of the infill points allocation is improved significantly by adding an extra layer of optimisation enhanced by a validation process.
Medical student's perspective of problem based learning (PBL ...
African Journals Online (AJOL)
Medical student's perspective of problem based learning (PBL) curriculum at the University of Traskei. ... The use of SWOT analysis to evaluate current and future directions can lead to the successful evolution of any organization. The aim ... It also gives them the opportunity to meet the outcomes of the program in due time.
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' ...
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. A ...
Training Team Problem Solving Skills: An Event-Based Approach.
Oser, R. L.; Gualtieri, J. W.; Cannon-Bowers, J. A.; Salas, E.
1999-01-01
Discusses how to train teams in problem-solving skills. Topics include team training, the use of technology, instructional strategies, simulations and training, theoretical framework, and an event-based approach for training teams to perform in naturalistic environments. Contains 68 references. (Author/LRW)
Problem-Based Learning for Production and Operations Management
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…
Teacher interventions in a problem-based hospitality management programme
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
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' ...
Teaching Agile Software Engineering Using Problem-Based Learning
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…
The Bologna Process and Lifelong Education: Problem-Based Learning
Hernandez-Encuentra, Eulalia; Sanchez-Carbonell, Javier
2005-01-01
This article describes the application of Problem-Based Learning (PBL) methodology in the context of a student congress, arguing that such new approaches to learning are best-suited to the goals of the Bologna Process. The Congress in question enabled Spanish graduate students in Psychology, many of them mid-career professionals, to increase their…
PHOTON PBL: problem-based learning in photonics technology education
Massa, Nicholas; Audet, Richard; Donnelly, Judith; Hanes, Fenna; Kehrhahn, Marijke
2007-06-01
Problem-based learning (PBL) is an educational approach whereby students learn course content by actively and collaboratively solving real-world problems presented in a context similar to that in which the learning is to be applied. Research shows that PBL improves student learning and retention, critical thinking and problem-solving skills, and the ability to skillfully apply knowledge to new situations - skills deemed critical to lifelong learning. Used extensively in medical education since the 1970's, and widely adopted in other fields including business, law, and education, PBL is emerging as an alternative to traditional lecture-based courses in engineering and technology education. In today's ever-changing global economy where photonics technicians are required to work productively in teams to solve complex problems across disciplines as well as cultures, PBL represents an exciting alternative to traditional lecture-based photonics education. In this paper we present the PHOTON PBL project, a National Science Foundation Advanced Technology Education (NSF-ATE) project aimed at creating, in partnership with the photonics industry and university research labs from across the US, a comprehensive series of multimedia-based PBL instructional resource materials and offering faculty professional development in the use of PBL in photonics technology education. Quantitative and qualitative research will be conducted on the effectiveness of PBL in photonics technician education.
Password authentication scheme based on the quadratic residue problem
Ali, Muhammad Helmi; Ismail, Eddie Shahril
2017-04-01
In this paper, we propose a new password-authentication scheme based on quadratic residue problem with the following advantages: the scheme does not require a verification file, and the scheme can withstand replay attacks and resist from the guessing and impersonation attacks. We next discuss the advantages of our designated scheme over other schemes in terms of security and efficiency.
Problem based teaching in indoor Air Science and Practice
DEFF Research Database (Denmark)
Kjærgaard, Søren K.
1999-01-01
a month achieving, evaluating literature, and using a strategic algorithm based on 1) problem analysis, 2) setting goals and target groups, 3) selecting intervention, 3) implementation of intervention, and 4) evaluation. An example has been childhood asthma and indoor air pollution. It is suggested...
Educational Data Mining and Problem-Based Learning
Walldén, Sari; Mäkinen, Erkki
2014-01-01
This paper considers the use of log data provided by learning management systems when studying whether students obey the problem-based learning (PBL) method. Log analysis turns out to be a valuable tool in measuring the use of the learning material of interest. It gives reliable figures concerning not only the number of use sessions but also the…
A Multilevel Analysis of Problem-Based Learning Design Characteristics
Scott, Kimberly S.
2014-01-01
The increasing use of experience-centered approaches like problem-based learning (PBL) by learning and development practitioners and management educators has raised interest in how to design, implement and evaluate PBL in that field. Of particular interest is how to evaluate the relative impact of design characteristics that exist at the…
A Schoolwide Investment in Problem-Based Learning
Sutton, Paul S.; Knuth, Randy
2017-01-01
A comprehensive high school in Bellevue, Washington, embraces problem-based learning as its strategy for improvement. Supported by a federal i3 grant, the school spent five years preparing for a widespread launch of PBL at the school. After several years of implementation, researchers learned that students perform the same or better on…
Problem-Based Learning in Engineering Ethics Courses
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,…
Foundations of problem-based learning: Some explanatory notes
H.G. Schmidt (Henk)
1993-01-01
textabstractThe present article elaborates on cognitive effects of problem-based learning put forward by Schmidt, De Volder, De Grave, Moust & Patel (1989) and Norman & Schmidt (1992). Its purpose is to discuss, in some detail, the theoretical premises of this approach to learning and instruction.
Students' Experience of Problem-Based Learning in Virtual Space
Gibbings, Peter; Lidstone, John; Bruce, Christine
2015-01-01
This paper reports outcomes of a study focused on discovering qualitatively different ways students experience problem-based learning in virtual space. A well-accepted and documented qualitative research method was adopted for this study. Five qualitatively different conceptions are described, each revealing characteristics of increasingly complex…
The Guinea Pigs of a Problem-Based Learning Curriculum
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…
Utilizing Problem-Based Learning in Qualitative Analysis Lab Experiments
Hicks, Randall W.; Bevsek, Holly M.
2012-01-01
A series of qualitative analysis (QA) laboratory experiments utilizing a problem-based learning (PBL) module has been designed and implemented. The module guided students through the experiments under the guise of cleaning up a potentially contaminated water site as employees of an environmental chemistry laboratory. The main goal was the…
Blended Problem-Based Learning for Teacher Education: Lessons Learnt
Donnelly, Roisin
2006-01-01
This paper explores case study research of the group process for teachers as learners in an Online Learning Module delivered in a blended problem-based learning (PBL) environment. Blended learning, as the name suggests, consists of a blend of at least two pedagogical approaches: within the context of this research, blended learning is the…
Problem Posing Based on Investigation Activities by University Students
da Ponte, Joao Pedro; Henriques, Ana
2013-01-01
This paper reports a classroom-based study involving investigation activities in a university numerical analysis course. The study aims to analyse students' mathematical processes and to understand how these activities provide opportunities for problem posing. The investigations were intended to stimulate students in asking questions, to trigger…
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 ...
Adapting Problem-Based Learning to Social Studies Teacher Education.
Hughes, Andrew S.; Sears, Alan M.; Clarke, Gerald M.
1998-01-01
Describes how Problem-Based Learning (PBL) was adapted for use in social studies teacher education. Reviews the background of PBL as used in professional faculties, and offers curricular justification for its use. Examines difficulties experienced in adapting PBL to teacher education, taking into account perspectives from prospective teachers and…
Introducing problem-based learning (PBL) into a foundation ...
African Journals Online (AJOL)
patterns, typified by processing the subject matter critically and self-regulating learning processes. The sustainability of the ..... the easiest way possible, checking progress regularly and thinking about ways to improve it” (Student ..... Problem-based learning for nursing: integrating lessons from other disciplines with nursing ...
SMILE Maker : a web-based tool for problem solving
Stoyanov, S.; Aroyo, L.M.; Kommers, Petrus A.M.; Ivanov, Ivan
1999-01-01
This paper focuses on the purposes, theoretical model, and functionality of the SMILE (Solution Mapping Intelligent Learning Environment) Maker--a World Wide Web-based problem-solving tool. From an instructional design point of view, an attempt to establish a balance between
Proximity graphs based multi-scale image segmentation
Energy Technology Data Exchange (ETDEWEB)
Skurikhin, Alexei N [Los Alamos National Laboratory
2008-01-01
We present a novel multi-scale image segmentation approach based on irregular triangular and polygonal tessellations produced by proximity graphs. Our approach consists of two separate stages: polygonal seeds generation followed by an iterative bottom-up polygon agglomeration into larger chunks. We employ constrained Delaunay triangulation combined with the principles known from the visual perception to extract an initial ,irregular polygonal tessellation of the image. These initial polygons are built upon a triangular mesh composed of irregular sized triangles and their shapes are ad'apted to the image content. We then represent the image as a graph with vertices corresponding to the polygons and edges reflecting polygon relations. The segmentation problem is then formulated as Minimum Spanning Tree extraction. We build a successive fine-to-coarse hierarchy of irregular polygonal grids by an iterative graph contraction constructing Minimum Spanning Tree. The contraction uses local information and merges the polygons bottom-up based on local region-and edge-based characteristics.
Directory of Open Access Journals (Sweden)
Alimul Muniroh
2016-08-01
Full Text Available Abstract: This study was conducted to determine the improvement of students' academic engagement through the implementation of problem based-learning model in the madrasah. This study used single subject design with multiple baseline across subjects. The subjects served as intervention targets as well as the control participant. There are four students as participants. They were chosen based on both the result of subject identification through instruments of Academic Engagement Scale for Grade School Students (AES-GS and the result of observation to students with the lowest grades. The results of the graph analysis showed the decreased behavior in baseline phase but increased in the intervention phase. Key Words: academic engagement, problem based learning, Madrasah Tsanawiyah Abstrak: Penelitian ini dilaksanakan untuk mengetahui peningkatan academic engagement siswa melalui penerapan model Problem Based Learning (PBL di madrasah. Penelitian ini menggunakan rancangan eksperimen subjek tunggal dengan desain multiple baseline across subject. Subjek penelitian yang diintervensi sekaligus sebagai control participant. Jumlah subjek penelitian sebanyak empat siswa. Subjek penelitian dipilih berdasarkan hasil identifikasi subjek melalui instrumen academic engagement scale for grade school students (AES-GS dengan perolehan hasil nilai paling rendah dan hasil observasi terhadap siswa yang menunjukkan nilai stabil rendah. Hasil analisis grafik pada kondisi baseline menunjukkan perilaku academic engagement stabil rendah, namun pada kondisi intervensi perilaku academic engagement meningkat. Kata kunci: academic engagement, problem based learning, Madrasah Tsanawiyah
Using Technology to Support Project and Problem-based Learning
Donnelly, Roisin
2005-01-01
This chapter is aimed at supporting lecturers in universities and colleges who have begun or are considering introducing project or problem-based learning (PBL) for students’ learning. In order to keep up with rapid change and make the most of learning technologies as aids to both learning strategies, a range of practical insights based on research will be provided in sections, supplemented with a variety of examples of learning technology being infused into both strategies. The range provide...
The patient's voice in a problem-based learning case.
Chur-Hansen, Anna; Koopowitz, Les
2004-03-01
Problem-based learning (PBL) relies upon trigger material, often a paper case, to stimulate self-directed enquiry and group discussion. We describe the process of writing a PBL case based upon a patient's narrative account of her experiences of psychiatric illness, and the possible benefits of that collaboration for the patient, as well as for student learning. Real patients are under-utilized in teaching, as are their narratives, and both are believed to be resources worthy of further attention.
Directory of Open Access Journals (Sweden)
Özalp Ekinci
2012-09-01
Full Text Available OBJECTIVE: This study aimed to investigate the occurrence of psychiatric problems in children and adolescents with sickle cell disease (SCD. METHODS: The Child Behavior Checklist for ages 4-18 years (CBCL/4-18, Conners’ Parent Rating Scale (CPRS, Conners’ Teacher Rating Scale (CTRS-R, and The Turgay DSM-IV Based Child and Adolescent Behavior Disorders Screening and Rating Scale, clinician and parent forms (T-DSM-IV-S were given to the caregivers and teachers of 31 children with SCD aged between 7-18 years and the caregivers and teachers of 34 age matched controls with irondeficiency anemia. RESULTS: The SCD patients had higher scores on all 4 of scales. Among the subscales, internalizing problems, and attention problems were more prominent in the SCD patients. CONCLUSION: Children and adolescents with SCD appear to have an increased risk for psychiatric problems. Regular psychological evaluation and referral to child and adolescent psychiatry clinics may facilitate timely diagnosis and effective treatment of at-risk children and adolescents.
Web-Based Problem-Solving Assignment and Grading System
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.
Weaving a Formal Methods Education with Problem-Based Learning
Gibson, J. Paul
The idea of weaving formal methods through computing (or software engineering) degrees is not a new one. However, there has been little success in developing and implementing such a curriculum. Formal methods continue to be taught as stand-alone modules and students, in general, fail to see how fundamental these methods are to the engineering of software. A major problem is one of motivation — how can the students be expected to enthusiastically embrace a challenging subject when the learning benefits, beyond passing an exam and achieving curriculum credits, are not clear? Problem-based learning has gradually moved from being an innovative pedagogique technique, commonly used to better-motivate students, to being widely adopted in the teaching of many different disciplines, including computer science and software engineering. Our experience shows that a good problem can be re-used throughout a student's academic life. In fact, the best computing problems can be used with children (young and old), undergraduates and postgraduates. In this paper we present a process for weaving formal methods through a University curriculum that is founded on the application of problem-based learning and a library of good software engineering problems, where students learn about formal methods without sitting a traditional formal methods module. The process of constructing good problems and integrating them into the curriculum is shown to be analagous to the process of engineering software. This approach is not intended to replace more traditional formal methods modules: it will better prepare students for such specialised modules and ensure that all students have an understanding and appreciation for formal methods even if they do not go on to specialise in them.
Problem-based learning in Guyana: a nursing education experiment.
O'Connor, J; Carr, A
2012-09-01
This paper invites the reader into sharing a journey of change through a new curriculum grounded in a problem-based learning (PBL) approach to education in the first year of a diploma nursing programme in Guyana. In Guyana, students are trained using traditional teaching methods: lectures and a single, often outdated, text. The authors had been dissatisfied previously with their students' knowledge retention, critical thinking skills and application abilities. The authors became advocates for change through the introduction of a PBL approach in nursing education within their school. PBL is quite different from 'problem solving', and the goal of learning is not to solve the problem, which has been presented. Rather, the problem is used to help students identify their own learning needs as they attempt to understand the problem, to pull together, synthesize and apply information to the problem, and to begin to work effectively to learn from group members as well as tutors. Students met in small groups to identify the problem; explore their pre-existing knowledge; generate hypotheses and possible mechanisms; and identify learning issues. Students in their first exposure to self-directed, small group learning can immediately thrive as active learners with minimal guidance and support. The programme was evaluated with the admission and scoring of homework/exams based on the school syllabus for the individual courses; and continual small group oral as well as a final written qualitative evaluation. Specific positive and negative learning factors are addressed. © 2011 The Authors. International Nursing Review © 2011 International Council of Nurses.
Two Bootstrap Strategies for a k-Problem up to Location-Scale with Dependent Samples
Directory of Open Access Journals (Sweden)
Jean-François Quessy
2014-01-01
Full Text Available This paper extends the work of Quessy and Éthier (2012 who considered tests for the k-sample problem with dependent samples. Here, the marginal distributions are allowed, under H0, to differ according to their mean and their variance; in other words, one focuses on the shape of the distributions. Although easily stated, this problem nevertheless requires a careful treatment for the computation of valid P values. To this end, two bootstrap strategies based on the multiplier central limit theorem are proposed, both exploiting a representation of the test statistics in terms of a Hadamard differentiable functional. This accounts for the fact that one works with empirically standardized data instead of the original observations. Simulations reported show the nice sample properties of the method based on Cramér-von Mises and characteristic function type statistics. The newly introduced tests are illustrated on the marginal distributions of the eight-dimensional Oil currency data set.
Solving problems with group work in problem-based learning: hold on to the philosophy.
Dolmans, D H; Wolfhagen, I H; van der Vleuten, C P; Wijnen, W H
2001-09-01
Problem-based learning (PBL) has gained a foothold within many schools in higher education as a response to the problems faced within traditional education. Working with PBL tutorial groups is assumed to have positive effects on student learning. Several studies provide empirical evidence that PBL stimulates cognitive effects and leads to restructuring of knowledge and enhanced intrinsic interest in the subject matter. However, staff members do not always experience the positive effects of group work which they had hoped for. When confronted with problems in group work, such as students who only maintain an appearance of being actively involved and students who let others do the work, teachers all too often implement solutions which can be characterized as teacher- directed rather than student-directed. Teachers tend to choose solutions which are familiar from their own experience during professional training, i.e. using the teacher-directed model. These solutions are not effective in improving group work and the negative experiences persist. It is argued that teachers should hold on to the underlying educational philosophy when solving problems arising from group work in PBL, by choosing actions which are consistent with the student-directed view of education in PBL.
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...... attractive for the industry in general, and not only for the space industry....... 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...
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....
Memristor-based memory: The sneak paths problem and solutions
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.
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....
Restart-Based Genetic Algorithm for the Quadratic Assignment Problem
Misevicius, Alfonsas
The power of genetic algorithms (GAs) has been demonstrated for various domains of the computer science, including combinatorial optimization. In this paper, we propose a new conceptual modification of the genetic algorithm entitled a "restart-based genetic algorithm" (RGA). An effective implementation of RGA for a well-known combinatorial optimization problem, the quadratic assignment problem (QAP), is discussed. The results obtained from the computational experiments on the QAP instances from the publicly available library QAPLIB show excellent performance of RGA. This is especially true for the real-life like QAPs.
Evaluation of problem-based learning in medical students' education.
Imanieh, Mohammad Hadi; Dehghani, Seyed Mohsen; Sobhani, Ahmad Reza; Haghighat, Mahmood
2014-01-01
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. 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. 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 problem-based 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). It may be concluded that problem-based learning method leads to a
Problem based learning in acoustics at Aalborg University
DEFF Research Database (Denmark)
Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Christensen, Flemming
2010-01-01
The master program in Acoustics (M. Sc.) from Aalborg University is taught at the Department of Electronic system. The M. Sc. program consists of three semesters with course units and problem based project work organized in groups, and a final semester for a master thesis. During the first three...... semesters, the learning objectives are distributed between courses with independent examination, and a semester project. Each semester has a theme the projects must comply with. Either supervisors, students or industry propose the problem that become the basis for the project work. Under supervision......, the students narrow down the problem, address possible solutions, and typically implement one or more of the options for further evaluation. The courses supplement the project work by adding specific and general knowledge of the subject areas of each semester. The courses either have direct application...
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 $[t_2, t_3] cap mathbb{T}$.
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.
Problem and Project Based Learning in Hybrid Spaces
DEFF Research Database (Denmark)
Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien
2016-01-01
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......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...... of networked learning' and one that impacts on the kind and nature of collaboration that takes place....
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
How students perceive problem-based learning (PBL) group tutorials at a Swedish Medical College
Szabó, Zoltán; Harangi, Márta; Nylander, Eva; Ljungman, Anders; Theodorsson, Annette; Ahn, Henrik; Davidsson, Bo
2015-01-01
Introduction: student perception of problem-based learning (PBL) group tutorials was investigated at a Swedish University Medical College 27 years after the introduction of PBL into the curriculum. Methods: a survey questionnaire comprising 43 questions answered on a Likert-type scale, together with one open question was used. The questionnaire was distributed to all 821 students taking part in the Linköping University medical program at the beginning of the Spring Term 2013. The results were...
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.
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.
Student reactions to problem-based learning in photonics technician education
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.
Heyne, David A.; Vreeke, Leonie J.; Maric, Marija; Boelens, Harrie; Van Widenfelt, Brigit 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 indicate problems with the wording…
Solving the problem of imaging resolution: stochastic multi-scale image fusion
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
ACTIVITY-BASED COSTING FOR VEHICLE ROUTING PROBLEMS
Directory of Open Access Journals (Sweden)
A. J. Moolman
2012-01-01
Full Text Available
ENGLISH ABSTRACT:Activity-based costing (ABC is a costing model that identifies activity costs in an organisation. It assigns the cost of activity resources to generate the actual cost of products in order to eliminateunprofitable products and to lowerthe prices of overpriced ones. The vehicle routing problem (VRP is a combinatorial optimisation and nonlinear programming problem that seeks to service a number of customers with a fleet of vehicles in a cost-effective manner. In this article we propose a new approach to determine costing for vehicle routing type problems. The methodology incorporates the predictive sharing of a resource by clustering producers.
AFRIKAANSE OPSOMMING: ‘Activity-based costing’ (ABC is ’n kostemodel wat die aktiwiteitskoste in ’n organisasie identifiseer. Dit allokeer die koste van die bronne sodat die ware koste van die vervaardiging en dienste van die produk bereken kan word om winsgewendheid te bepaal. Die ‘vehicle routing problem’ (VRP is ’n kombinatoriese optimisering en nie-lineêre programmeringsprobleem wat verskeie kliënte met ’n vloot voertuie in die mees koste- effektiewe manier bedien. Die artikel bespreek ’n nuwe metode om die kombinasie van probleme op te los. Die metode maak gebruik van groeperingsalgoritmes om meer akkurate voertuig deling te voorspel.
The ROI CT problem: a shearlet-based regularization approach
Bubba, T. A.; Porta, F.; Zanghirati, G.; Bonettini, S.
2016-10-01
The possibility to significantly reduce the X-ray radiation dose and shorten the scanning time is particularly appealing, especially for the medical imaging community. Region- of-interest Computed Tomography (ROI CT) has this potential and, for this reason, is currently receiving increasing attention. Due to the truncation of projection images, ROI CT is a rather challenging problem. Indeed, the ROI reconstruction problem is severely ill-posed in general and naive local reconstruction algorithms tend to be very unstable. To obtain a stable and reliable reconstruction, under suitable noise circumstances, we formulate the ROI CT problem as a convex optimization problem with a regularization term based on shearlets, and possibly nonsmooth. For the solution, we propose and analyze an iterative approach based on the variable metric inexact line-search algorithm (VMILA). The reconstruction performance of VMILA is compared against different regularization conditions, in the case of fan-beam CT simulated data. The numerical tests show that our approach is insensitive to the location of the ROI and remains very stable also when the ROI size is rather small.
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.
Fujisaki, Keisuke; Ikeda, Tomoyuki
2013-01-01
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. PMID:28788395
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.
GPU-based large-scale visualization
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
Preeti, Bajaj; Ashish, Ahuja; Shriram, Gosavi
2013-12-01
As the "Science of Medicine" is getting advanced day-by-day, need for better pedagogies & learning techniques are imperative. Problem Based Learning (PBL) is an effective way of delivering medical education in a coherent, integrated & focused manner. It has several advantages over conventional and age-old teaching methods of routine. It is based on principles of adult learning theory, including student's motivation, encouragement to set goals, think critically about decision making in day-to-day operations. Above all these, it stimulates challenge acceptance and learning curiosity among students and creates pragmatic educational program. To measure the effectiveness of the "Problem Based Learning" as compared to conventional theory/didactic lectures based learning. The study was conducted on 72 medical students from Dayanand Medical College & Hospital, Ludhiana. Two modules of problem based sessions designed and delivered. Pre & Post-test score's scientific statistical analysis was done. Student feed-back received based on questionnaire in the five-point Likert scale format. Significant improvement in overall performance observed. Feedback revealed majority agreement that "Problem-based learning" helped them create interest (88.8 %), better understanding (86%) & promotes self-directed subject learning (91.6 %). Substantial improvement in the post-test scores clearly reveals acceptance of PBL over conventional learning. PBL ensures better practical learning, ability to create interest, subject understanding. It is a modern-day educational strategy, an effective tool to objectively improve the knowledge acquisition in Medical Teaching.
Banerjee, Biswanath; Walsh, Timothy F.; Aquino, Wilkins; Bonnet, Marc
2012-01-01
This paper presents the formulation and implementation of an Error in Constitutive Equations (ECE) method suitable for large-scale inverse identification of linear elastic material properties in the context of steady-state elastodynamics. In ECE-based methods, the inverse problem is postulated as an optimization problem in which the cost functional measures the discrepancy in the constitutive equations that connect kinematically admissible strains and dynamically admissible stresses. Furthermore, in a more recent modality of this methodology introduced by Feissel and Allix (2007), referred to as the Modified ECE (MECE), the measured data is incorporated into the formulation as a quadratic penalty term. We show that a simple and efficient continuation scheme for the penalty term, suggested by the theory of quadratic penalty methods, can significantly accelerate the convergence of the MECE algorithm. Furthermore, a (block) successive over-relaxation (SOR) technique is introduced, enabling the use of existing parallel finite element codes with minimal modification to solve the coupled system of equations that arises from the optimality conditions in MECE methods. Our numerical results demonstrate that the proposed methodology can successfully reconstruct the spatial distribution of elastic material parameters from partial and noisy measurements in as few as ten iterations in a 2D example and fifty in a 3D example. We show (through numerical experiments) that the proposed continuation scheme can improve the rate of convergence of MECE methods by at least an order of magnitude versus the alternative of using a fixed penalty parameter. Furthermore, the proposed block SOR strategy coupled with existing parallel solvers produces a computationally efficient MECE method that can be used for large scale materials identification problems, as demonstrated on a 3D example involving about 400,000 unknown moduli. Finally, our numerical results suggest that the proposed MECE
Using Multimedia in Large-Scale Computer-Based Testing Programs.
Bennett, R. E.; Goodman, M.; Hessinger, J.; Kahn, H.; Ligget, J.; Marshall, G.; Zack, J.
1999-01-01
Discusses the use of multimedia in large-scale computer-based testing programs to measure problem solving and related cognitive constructs more effectively. Considers the incorporation of dynamic stimuli such as audio, video, and animation, and gives examples in history, physical education, and the sciences. (Author/LRW)
Problem-based learning in optical engineering studies
Voznesenskaya, Anna
2016-09-01
Nowadays, the Problem-Based Learning (PBL) is one of the most prospective educational technologies. PBL is based on evaluation of learning outcomes of a student, both professional and personal, instead of traditional evaluation of theoretical knowledge and selective practical skills. Such an approach requires changes in the curricula development. There should be introduced projects (cases) imitating real tasks from the professional life. These cases should include a problem summary with necessary theoretic description, charts, graphs, information sources etc, task to implement and evaluation indicators and criteria. Often these cases are evaluated with the assessment-center method. To motivate students for the given task they could be divided into groups and have a contest. Whilst it looks easy to implement in social, economic or teaching fields PBL is pretty complicated in engineering studies. Examples of cases in the first-cycle optical engineering studies are shown in this paper. Procedures of the PBL implementation and evaluation are described.
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.
Text Summarization Model based on Facility Location Problem
Takamura, Hiroya; Okumura, Manabu
e propose a novel multi-document generic summarization model based on the budgeted median problem, which is a facility location problem. The summarization method based on our model is an extractive method, which selects sentences from the given document cluster and generates a summary. Each sentence in the document cluster will be assigned to one of the selected sentences, where the former sentece is supposed to be represented by the latter. Our method selects sentences to generate a summary that yields a good sentence assignment and hence covers the whole content of the document cluster. An advantage of this method is that it can incorporate asymmetric relations between sentences such as textual entailment. Through experiments, we showed that the proposed method yields good summaries on the dataset of DUC'04.
Problem Based Learning and Education for Sustainable Development
DEFF Research Database (Denmark)
Guerra, Aida
2012-01-01
are problem based learning (PBL), project based learning (PjBL), case study, role play, group discussion, field work, etc. These learning approaches are capable of integrating education for sustainable development (ESD) in engineering education at different levels, and do not aim to substitute the core......An engineering education that integrates education for sustainable development (ESD) perspectives claims for a learning approach centred on students, interdisciplinary and problem oriented, and this cannot be achieve through an “add on” strategy. Example of such active learning approaches...... scientific and technological knowledge but instead align it with the social, economic and environmental dimensions of the professional practice. It is agreed among ESD experts that PBL is a suitable learning approach to integrate ESD in the engineering curricula. This paper provides an overview...
Graue, Marit; Haugstvedt, Anne; Wentzel-Larsen, Tore; Iversen, Marjolein M; Karlsen, Bjørg; Rokne, Berit
2012-02-01
Regular assessment of diabetes-related emotional distress is recommended to identify high-risk people with diabetes and to further prevent negative effects on self-management. Nevertheless, psychological problems are greatly under diagnosed. Translating and testing instruments for psychosocial assessment across languages, countries and cultures allow for further research collaboration and enhance the prospect of improving treatment and care. To examine the psychometric properties of the Norwegian versions of the Problem Areas in Diabetes Scale and the Diabetes Distress Scale. Cross-sectional survey design. A sample comprising adults with diabetes (response rate 71%) completed the Problem Areas in Diabetes Scale and the Diabetes Distress Scale, which were translated into Norwegian with standard forward-backwards translation. The study included 292 participants with type 1 (80%) and type 2 diabetes (20%) aged 18-69 years, 58% males, mean diabetes duration 17.3 years (11.6), mean HbA(1c) 8.2% (1.6). We used exploratory factor analysis with principal axis factoring and varimax rotation to investigate the factor structure and performed confirmatory factor analysis to test the best fit of a priori-defined models. Convergent and discriminate validity were examined using the Short Form-36 Health Survey, Hospital Anxiety and Depression Scale and demographic and disease-related clinical variables. We explored reliability by internal consistency and test-retest analysis. Exploratory factor analysis supported a four-factor model for the Diabetes Distress Scale. Confirmatory factor analysis indicated that the data and the hypothesized model for the Diabetes Distress Scale fit acceptably but not for the Problem Areas in Diabetes Scale. Greater distress assessed with both instruments correlated moderately with lower health-related quality of life and greater anxiety and depression. The instruments discriminated between those having additional health conditions or disabilities
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.
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.
Cognitive engagement in the problem-based learning classroom
Rotgans, Jerome; Schmidt, Henk
2011-01-01
textabstractThe objective of the present study was to examine to what extent autonomy in problem-based learning (PBL) results in cognitive engagement with the topic at hand. To that end, a short self-report instrument was devised and validated. Moreover, it was examined how cognitive engagement develops as a function of the learning process and the extent to which cognitive engagement determines subsequent levels of cognitive engagement during a one-day PBL event. Data were analyzed by means ...
Problem-Based Learning: Validation of an assessment instrument
Petra Micu, Ileana; Coordinación de Enseñanza Facultad de Medicina Universidad Autónoma de México D.F., México; Valle, Rosa María; Dirección General de Evaluación Educativa Universidad Autónoma de México D.F., México; Martínez Gonzáles, Adrián; Dirección General de Estudios de Posgrado Universidad Autónoma de México D.F., México; Piña G., Beatriz; Sistema de Universidad Abierta Universidad Autónoma de México D.F., México; Rojas Ramírez, José; Departamento de Farmacología Facultad de Medicina Universidad Autónoma de México D.F., México; Morales López, Sara; Secretaría de Enseñanza Clínica, Internado y Servicio Social Facultad de Medicina Universidad Autónoma de México D.F., México
2014-01-01
OBJECTIVES: To analyze the labour of a multidisciplinary work group in preparing of an instrument for asssessing the performance of students during work sessions of the teaching strategy tenned ProblemBased Leming (PBL), as well some methods useful for previos assessment of instrument and its results, in order to prepare the questionnaire for its statistical assessment. MATERIALS AND METHODS: Four critical areas were taken into account: Characteristics and organization of both the work group ...
Problem-Based Learning to Improve Students’ Grammar Competence
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Mukminatus Zuhriyah
2017-06-01
Full Text Available Grammar becomes one of the subjects studied in all Indonesian English Department. It is because grammar has the important role in all English skills. Grammar makes those four English skills meaningful. Somebody can be said as a master of English when he or she also masters grammar. Unfortunately, learning grammar is not as easy as what we think. It needs the effective method that can make the learners motivated and active in learning as well as in applying the grammar in the real life. Problem-based learning applied in this research is one of the alternatives that can help the learners learn grammar easily. This research was a collaborative action research whose general purpose to know whether or not Problem-based learning could improve the students’ grammar competence. Meanwhile, the specific purposes were to know the lecturer’s activities, the students’ activities, and the students’ responses when problem-based learning was implemented in grammar class. Nine students of the fifth semester of English department of education faculty of Hasyim Asy’ari University (UNHASY Tebuireng Jombang in the academic year of 2016/2017 became the subjects of this research. The data got was from the observation notes and the grammar test. There was an improvement on students’ grammar competence from cycle one to cycle two. It was proven by their mean score from 66.7 in cycle one to 72.8 in cycle two. Meanwhile, the percentage of students passing the minimum mastery criteria was from 44.4 in cycle one and 88.9 in cycle two. So that it can be concluded that problem-based learning could improve students’ grammar competence.
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.
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...... they experience learning the most. Possible reasons for this discrepancy, and implications for teaching, are discussed....
Evaluating potentialities and constrains of Problem Based Learning curriculum
DEFF Research Database (Denmark)
Guerra, Aida
2013-01-01
encloses three methodological approaches to investigate three interrelated research questions. Phase one, a literature review; aims develop a theoretical and analytical framework. The second phase aims to investigate examples of practices that combine PBL and Education for Sustainable Development (ESD......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...
High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems
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
High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems.
Mahadevan, Vijay S; Merzari, Elia; Tautges, Timothy; Jain, Rajeev; Obabko, Aleksandr; Smith, Michael; Fischer, Paul
2014-08-06
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.
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.
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
The Mercury Problem in Artisanal and Small-Scale Gold Mining.
Esdaile, Louisa J; Chalker, Justin M
2018-01-03
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
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...
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…
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…
Ohkitani, Koji
2017-01-01
We make a detailed comparison between the Navier-Stokes equations and their dynamically scaled counterpart, the so-called Leray equations. The Navier-Stokes equations are invariant under static scaling transforms, but are not generally invariant under dynamic scaling transforms. We will study how closely they can be brought together using the critical dependent variables and discuss the implications on the regularity problems. Assuming that the Navier-Stokes equations written in the vector potential have a solution that blows up at t = 1, we derive the Leray equations by dynamic scaling. We observe: (1) the Leray equations have only one term extra on top of those of the Navier-Stokes equations (2) we can recast the Navier-Stokes equations as a Wiener path integral and the Leray equations as another Ornstein-Uhlenbeck path integral. Using the Maruyama-Girsanov theorem, both equations take the identical form modulo the Maruyama-Girsanov density, which is valid up to t=2\\sqrt{2} by the Novikov condition (3) the global solution of the Leray equations is given by a finite-dimensional projection {\\boldsymbol{R}} of a functional of an Ornstein-Uhlenbeck process and a probability measure. If {\\boldsymbol{R}} remains smooth beyond t = 1 under an absolute continuous change of the probability measure, we can rule out finite-time blowup by contradiction. There are two cases: (A) {\\boldsymbol{R}} given by a finite number of Wiener integrals, and (B) otherwise. Ruling out blowup in (A) is straightforward. For (B), a condition based on a limit passage in the Picard iterations is identified for such a contradiction to come out. The whole argument equally holds in {{{R}}}d for any d≥slant 2.
Scaling Relationships Based on Scaled Tank Mixing and Transfer Test Results
Energy Technology Data Exchange (ETDEWEB)
Piepel, Gregory F.; Holmes, Aimee E.; Heredia-Langner, Alejandro
2013-09-18
This report documents the statistical analyses performed (by Pacific Northwest National Laboratory for Washington River Protection Solutions) on data from 26 tests conducted using two scaled tanks (43 and 120 inches) in the Small Scale Mixing Demonstration platform. The 26 tests varied several test parameters, including mixer-jet nozzle velocity, base simulant, supernatant viscosity, and capture velocity. For each test, samples were taken pre-transfer and during five batch transfers. The samples were analyzed for the concentrations (lbs/gal slurry) of four primary components in the base simulants (gibbsite, stainless steel, sand, and ZrO2). The statistical analyses including modeling the component concentrations as functions of test parameters using stepwise regression with two different model forms. The resulting models were used in an equivalent performance approach to calculate values of scaling exponents (for a simple geometric scaling relationship) as functions of the parameters in the component concentration models. The resulting models and scaling exponents are displayed in tables and graphically. The sensitivities of component concentrations and scaling exponents to the test parameters are presented graphically. These results will serve as inputs to subsequent work by other researchers to develop scaling relationships that are applicable to full-scale tanks.
Scaling Relationships Based on Scaled Tank Mixing and Transfer Test Results
Energy Technology Data Exchange (ETDEWEB)
Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Holmes, Aimee E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heredia-Langner, Alejandro [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lee, Kearn P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kelly, Steven E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2014-01-01
This report documents the statistical analyses performed (by Pacific Northwest National Laboratory for Washington River Protection Solutions) on data from 26 tests conducted using two scaled tanks (43 and 120 inches) in the Small Scale Mixing Demonstration platform. The 26 tests varied several test parameters, including mixer-jet nozzle velocity, base simulant, supernatant viscosity, and capture velocity. For each test, samples were taken pre-transfer and during five batch transfers. The samples were analyzed for the concentrations (lbs/gal slurry) of four primary components in the base simulants (gibbsite, stainless steel, sand, and ZrO2). The statistical analyses including modeling the component concentrations as functions of test parameters using stepwise regression with two different model forms. The resulting models were used in an equivalent performance approach to calculate values of scaling exponents (for a simple geometric scaling relationship) as functions of the parameters in the component concentration models. The resulting models and scaling exponents are displayed in tables and graphically. The sensitivities of component concentrations and scaling exponents to the test parameters are presented graphically. These results will serve as inputs to subsequent work by other researchers to develop scaling relationships that are applicable to full-scale tanks.
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
PENGEMBANGAN MODUL BERORIENTASI PROBLEM BASED LEARNING BERBANTUAN APLIKASI ANDROID
Directory of Open Access Journals (Sweden)
Anggih Alfiantara
2017-02-01
Full Text Available Peningkatan kualitas pembelajaran dapat dilakukan dari berbagai variabel pembelajaran, salah satunya berupa modul sebagai variabel bahan ajar. Pengembangan modul berbantuan android application mobile berorientasi Problem Based Learning diharapkan dapat meningkatkan aktivitas dan hasil belajar. Penelitian pengembangan ini bertujuan untuk mengetahui validitas modul berorientasi Problem Based Learning dan untuk mendapatkan respon dari pengguna. Desain penelitian yang digunakan yaitu four-D Models yang dimodifikasi. Pengumpulan data menggunakan lembar validasi dan metode angket. Kelayakan awal bahan ajar ditentukan oleh ahli materi dan ahli media menggunakan teknik deskriptif persentase. Kelayakan akhir bahan ajar ditentukan berdasarkan hasil pengujian. Data hasil penelitian dianalisis menggunakan metode analisis deskriptif kuantitatif. Secara kuantitatif, data hasil penelitian dianalisis dengan cara menghitung rerata skor dan menentukan kriteria pada interval kelas tertentu. Uji validitas modul memperoleh nilai rata-rata sebesar 3,196, dengan persentase skor rata-rata 79,905%. Data skor perolehan angket tanggapan siswa sebesar 3,21, dan angket tanggapan guru sebesar 3,40, sehingga modul ini terbukti memenuhi kriteria layak yang didukung dengan respon baik dari pengguna. Berdasarkan hasil analisis data dapat disimpulkan bahwa modul ini dinyatakan valid dan mendapat respon baik dari pengguna sehingga dapat digunakan sebagai sumber belajar.Improving the quality of learning can be done from a variety of learning variables, one of them is a variable module as teaching materials. Module development with android application oriented Problem Based Learning is expected to increase activity and learning outcomes. This development study aims to determine the validity of the module oriented problem based learning and getting response from users. The study design used is four-D Models were modified. Data collection is using validation sheet and questionnaires
Pore-scale modeling of moving contact line problems in immiscible two-phase flow.
Kucala, A.; Noble, D.; Martinez, M. J.
2016-12-01
Two immiscible fluids in static equilibrium form a common interface along a solid surface, characterized as the static contact (wetting) angle and is a function of surface geometry, intermolecular forces, and interfacial surface energies manifested as interfacial tension. This static configuration may become perturbed due to external force imbalances (mass injection, pressure gradients, buoyancy, etc.) and the contact line location and interface curvature becomes dynamic. Accurate modeling of moving contact line (MCL) problems is imperative in predicting capillary pressure vs. saturation curves, permeability, and preferential flow paths for a variety of applications, including geological carbon storage (GCS) and enhanced oil recovery (EOR). Here, we present a model for the moving contact line using pore-scale computational fluid dynamics (CFD) which solves the full, time-dependent Navier-Stokes equations using the Galerkin finite-element method. The MCL is modeled as a surface traction force proportional to the surface tension, dependent on the static properties of the immiscible fluid/solid system. The moving two-phase interface is tracked using the level set method and discretized with the conformal decomposition finite element method (CDFEM), allowing for surface tension effects to be computed at the exact interface location. We present a variety of verification test cases for simple two- and three-dimensional geometries to validate the current model, including threshold pressure predictions in flows through pore-throats for a variety of wetting angles. Simulations involving more complex geometries are also presented to be used in future simulations for GCS and EOR problems. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000
Problem-based learning in continuing medical education
Al-Azri, Hilal; Ratnapalan, Savithiri
2014-01-01
Abstract Objective To investigate the effects of problem-based learning (PBL) in continuing medical education. Data sources PubMed, MEDLINE, EMBASE, CINAHL, and ERIC databases were searched for randomized controlled trials published in English from January 2001 to May 2011 using key words problem-based learning, practice-based, self-directed, learner-centered, and active learning, combined with continuing medical education, continuing professional development, post professional, postgraduate, and adult learning. Study selection Randomized controlled trials that described the effects of PBL on knowledge enhancement, performance improvement, participants’ satisfaction, or patients’ health outcomes were selected for analysis. Synthesis Fifteen studies were included in this review: 4 involved postgraduate trainee doctors, 10 involved practising physicians, and 1 had both groups. Online learning was used in 7 studies. Among postgraduate trainees PBL showed no significant differences in knowledge gain compared with lectures or non–case-based learning. In continuing education, PBL showed no significant difference in knowledge gain when compared with other methods. Several studies did not provide an educational intervention for the control group. Physician performance improvement showed an upward trend in groups participating in PBL, but no significant differences were noted in health outcomes. Conclusion Online PBL is a useful method of delivering continuing medical education. There is limited evidence that PBL in continuing education would enhance physicians’ performance or improve health outcomes. PMID:24522680
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.
Problem-based learning in a health sciences librarianship course.
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
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 l...... are presented using the surveying programme at Aalborg University as an example. This paper is work in progress and draws from previous research. The paper supports the lecture on Problem Based Learning given at NUST 3 March 2016.......-world context. The combination of different disciplines can be taught through a “learning-by-doing approach”. Problem solving skills can be taught through a project-oriented approach to surveying education with a focus on developing skills for “learning to learn”. The basic principles of this educational model...
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.
Large-scale Inference Problems in Astronomy: Building a 3D Galactic Dust Map
Finkbeiner, Douglas
2016-03-01
The term ''Big Data'' has become trite, as modern technology has made data sets of terabytes or even petabytes easy to store. Such data sets provide a sandbox in which to develop new statistical inference techniques that can extract interesting results from increasingly rich (and large) databases. I will give an example from my work on mapping the interstellar dust of the Milky Way. 2D emission-based maps have been used for decades to estimate the reddening and emission from interstellar dust, with applications from CMB foregrounds to surveys of large-scale structure. For studies within the Milky Way, however, the third dimension is required. I will present our work on a 3D dust map based on Pan-STARRS1 and 2MASS over 3/4 of the sky (http://arxiv.org/abs/1507.01005), assess its usefulness relative to other dust maps, and discuss future work. Supported by the NSF.
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.
Inquiry Teaching in Science - Problem Based Learning (PBL) in Astronomy
Soares, Rosa; Teixeira, Daniel; Roxo, Áurea; Ruas, Fátima
2015-04-01
Problem Based Learning (PBL) is a teaching methodology based on the Inquiry Teaching approach, which consists in finding a solution to a problem that requires the use of higher-level cognitive skills. It's best carried out in small groups. The scenario or problem must lead the student to ask questions and to find solutions through research. This methodology is a research-oriented approach, because it starts with questions (asked by the students after being introduced to the problem), it encourages the search for solutions, it develops scientific reasoning, and it helps students to learn about key aspects of scientific research, such as gathering data, finding evidence, looking for solutions, discussing and presenting findings. In PBL the teacher has the role of facilitator. In the study of the Solar System, the study of the Moon's craters started with the observation of photos, which led the students to ask questions like "What determines the size and shape of the craters?". To answer this question the students hypothesized about the size, speed and distance travelled of the object that hit the Moon. The students then planned and carried out an experimental activity to validate their hypotheses, using balls of different sizes and materials. The diameter and depth of the craters were estimated using Salsa J. With the data obtained in this experiment, the students did a Gowin's V diagram. In order to determine the relation between the characteristics of the celestial bodies and the craters formed, both on the Moon and on the Earth, we studied the Earth's craters. We used Impact Calculator, a program that estimates the effects of an impact on the Earth, using several variables, such as the size and density of the meteorite, and the speed and angle at which it impacts the Earth's surface. Another problem started with the film Visions of the Cosmos. It raised questions such as "Is there a relation between the Earth's past and the origin of the Solar System?" "How are
Solutions to a combined problem of excessive hydrogen sulfide in biogas and struvite scaling.
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
Hesse, Nikolas; Bodensteiner, Christoph; Arens, Michael
2014-10-01
Recognizing the location where an image was taken, solely based on visual content, is an important problem in computer vision, robotics and remote sensing. This paper evaluates the performance of standard approaches for location recognition when applied to large-scale aerial imagery in both electro-optical (EO) and infrared (IR) domains. We present guidelines towards optimizing the performance and explore how well a standard location recognition system is suited to handle IR data. We show on three datasets that the performance of the system strongly increases if SIFT descriptors computed on Hessian-Affine regions are used instead of SURF features. Applications are widespread and include vision-based navigation, precise object geo-referencing or mapping.
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.
Ohnhaus, E E; Adler, R
1975-12-01
The effect of analgesics on pathological pain in a double-blind, complete cross-over design was assessed by means of two rating scales, a verbal rating scale (VRS) and visual analogue scale (VAS). The VRS is widely used, but has several disadvantages as compared to the VAS. The results obtained by means of the VRS showed higher F-ratios (analysis of variance and Kruskall-Wallis H-test) than those obtained by means of the VAS. The VRS, which transfers a continuous feeling into a digital system, seems to augment artificially the measurement of effects produced by analgesics, and the VAS seems to assess more closely what a patient actually experiences with respect to change in pain intensities. The correlation between the two scales was highly significant (r = 0.81, P less than 0.001). The calculated regression line (y=-29.6 + 0.55-x) was not similar to the line of identity and showed much lower values for the VAS, supporting our interpretation. The distribution of the variances of the values obtained by means of both scales was not homogenous. This indicates that the homogeneity of the distribution of variances should always be checked and a Kruskall-Wallis H-test used, if they are inhomogenously distributed.
The impact of Project Northland on selected MMPI-A problem behavior scales.
Perry, Cheryl L; Lee, Susanne; Stigler, Melissa H; Farbakhsh, Kian; Komro, Kelli A; Gewirtz, Abigail H; Williams, Carolyn L
2007-09-01
Project Northland was a randomized community trial to prevent or delay alcohol use among adolescents. Students in the intervention communities were exposed to a multi-component prevention program in early adolescence and high school. This paper examines the impact of Project Northland on the trajectories of four scales of the adolescent form of the Minnesota Multiphasic Personality Inventory (MMPI-A). Students in the intervention communities demonstrated lower rates of growth of family problems and alcohol/drug use proneness than students in the delayed-program control communities. The results were more robust for baseline non-drinkers. EDITORS' STRATEGIC IMPLICATIONS: This experimental study extends the scope of the impact of Project Northland, already recognized as a model substance abuse prevention program by the Substance Abuse and Mental Health Services Administration. The results suggest that focused prevention programs have the potential to impact young adolescents' lives more broadly. Replication and further examination of the mechanisms by which risk factors and outcomes are modified is necessary, but school administrators and public health officials could learn from this promising program and evaluation.
Petrozzi, Angela; Gagliardi, Luigi
2013-07-01
The Edinburgh Postnatal Depression Scale (EPDS) is a widely used instrument for screening for postpartum depression, but it might also detect anxiety symptoms. To investigate the factor structure of the EPDS administered immediately after delivery and to understand which factors predict a high EPDS score 3 months later. A cohort of 594 Italian mothers delivering a healthy baby at Versilia Hospital completed the EPDS at two points in time: 2 days after delivery (T0) and 3 months later (T1) by telephone interview. EPDS scores were higher at T0 than at T1. Overall, 15.7% of women at 2 days postpartum and 7.6% at 3 months later reported a score >9. The factor analysis of EPDS at T0 indicated a three-factor structure: "depression" (items 7-10), "anxiety" (items 3-6) and "anhedonia" (items 1-2). Anxious symptoms were quantitatively more important than depressive ones (mean 3.9 vs. 1.2) but tended to spontaneously ameliorate at T1, whereas total EPDS score at T1 was better predicted by depressive symptoms at T0 (discriminative ability 0.75 vs. 0.68). This study suggests that EPDS subscales immediately after delivery help understand the spectrum of maternal postpartum psychological problems. Anxious symptoms immediately after delivery are frequent but transient, linked probably to maternity blues or atypical depression, whereas the presence of depressive symptomatology at T0 suggests higher risk of later depressive disorders.
Wang, Shoucheng; Huang, Guoqing; Wu, Xin
2018-02-01
In this paper, we survey the effect of dissipative forces including radiation pressure, Poynting–Robertson drag, and solar wind drag on the motion of dust grains with negligible mass, which are subjected to the gravities of the Sun and Jupiter moving in circular orbits. The effect of the dissipative parameter on the locations of five Lagrangian equilibrium points is estimated analytically. The instability of the triangular equilibrium point L4 caused by the drag forces is also shown analytically. In this case, the Jacobi constant varies with time, whereas its integral invariant relation still provides a probability for the applicability of the conventional fourth-order Runge–Kutta algorithm combined with the velocity scaling manifold correction scheme. Consequently, the velocity-only correction method significantly suppresses the effects of artificial dissipation and a rapid increase in trajectory errors caused by the uncorrected one. The stability time of an orbit, regardless of whether it is chaotic or not in the conservative problem, is apparently longer in the corrected case than in the uncorrected case when the dissipative forces are included. Although the artificial dissipation is ruled out, the drag dissipation leads to an escape of grains. Numerical evidence also demonstrates that more orbits near the triangular equilibrium point L4 escape as the integration time increases.
Role-playing in the problem-based learning class.
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.
ITO-based evolutionary algorithm to solve traveling salesman problem
Dong, Wenyong; Sheng, Kang; Yang, Chuanhua; Yi, Yunfei
2014-03-01
In this paper, a ITO algorithm inspired by ITO stochastic process is proposed for Traveling Salesmen Problems (TSP), so far, many meta-heuristic methods have been successfully applied to TSP, however, as a member of them, ITO needs further demonstration for TSP. So starting from designing the key operators, which include the move operator, wave operator, etc, the method based on ITO for TSP is presented, and moreover, the ITO algorithm performance under different parameter sets and the maintenance of population diversity information are also studied.
[Problem-based learning in nursing training: liberation or confinement?].
Goopy, S E; Sansoni, J
2001-01-01
In this article some considerations are introduced on the method of the Problem Based Learning (PBL) for Nursing education. The method is criticized in its application. From the idea that it can be an active method, not conservative and that can be useful to develop the critical thinking, if it is not correctly used, it can result instead in a method that confines the education, negatively standardizes it and limits the critical thought. Some reflection points are underlined to promote a debate on the topic.
Motivating programming students by Problem Based Learning and LEGO robots
DEFF Research Database (Denmark)
Lykke, Marianne; Coto Chotto, Mayela; Mora, Sonia
2014-01-01
Retention of first year students in Computer Science is a concern for universities internationally. Especially programming courses are regarded as difficult, and often have the highest failure and dropout rates. The Informatics School at Universidad Nacional in Costa Rica is not an exception....... 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...
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...... to some of their earlier learning experiences. They sensed a change in how they interacted with each other, a different tone arose in their social bonding, which led to the overall question for this article: What happens when play becomes part of a PBL process and how can we understand the relation...... between play and creativity in higher education learning processes?...
Medical Libraries and Problem Based Learning: New Challenges and Opportunities
Directory of Open Access Journals (Sweden)
Kuan-nien Chen
2004-06-01
Full Text Available This article explores the changing role of the medical library and librarians in the context of problem-based learning in terms of fives aspects － impacts on medical libraries, library instruction, technology, the collection, and the new role of the librarians. For the libraries, the role change process is ongoing rather than a single event. The medical school and the library must collaborate and interact in the areas of curriculum design, communications, and library user education. In addition, administrative supports such as budgets, staffing, and the building space of the library are always in demand. [Article content in Chinese
Solving Fractional Programming Problems based on Swarm Intelligence
Raouf, Osama Abdel; Hezam, Ibrahim M.
2014-04-01
This paper presents a new approach to solve Fractional Programming Problems (FPPs) based on two different Swarm Intelligence (SI) algorithms. The two algorithms are: Particle Swarm Optimization, and Firefly Algorithm. The two algorithms are tested using several FPP benchmark examples and two selected industrial applications. The test aims to prove the capability of the SI algorithms to solve any type of FPPs. The solution results employing the SI algorithms are compared with a number of exact and metaheuristic solution methods used for handling FPPs. Swarm Intelligence can be denoted as an effective technique for solving linear or nonlinear, non-differentiable fractional objective functions. Problems with an optimal solution at a finite point and an unbounded constraint set, can be solved using the proposed approach. Numerical examples are given to show the feasibility, effectiveness, and robustness of the proposed algorithm. The results obtained using the two SI algorithms revealed the superiority of the proposed technique among others in computational time. A better accuracy was remarkably observed in the solution results of the industrial application problems.
Internet-based interventions for youth dealing with gambling problems.
Monaghan, Sally; Wood, Richard T A
2010-01-01
A substantial proportion of adolescents and young adults gamble and rates of problem gambling amongst youth are significantly higher than found in adult populations. Despite this, few youth seek treatment suggesting that traditional services are failing to help this vulnerable population. Youth are progressively active online and use the Internet for social networking, recreation, and increasingly, to seek help for health and mental health issues where they would not be comfortable seeking traditional forms of professional help. In recognition of this, Internet-based therapy and guided interventions have been launched specifically for adolescents and young adults in an attempt to reduce high-risk behaviors and increase program utilization. Research has demonstrated that online therapeutic support is perceived to be acceptable and useful by youth. Furthermore, online interventions have demonstrated success in reducing smoking and heavy drinking amongst this typically hard to reach population. Given the success of similar programs, online problem gambling services are predicted to be effective in increasing youth awareness of their potentially problematic gambling behavior and assist adolescents and young adults in retaining control and minimizing and reducing gambling-related problems.
Evaluating a problem based learning course: an action research study.
Walker, J; Bailey, S; Brasell-Brian, R; Gould, S
2001-03-01
Problem based learning (PBL) has been widely used in the United States, United Kingdom and Australasia in undergraduate nursing education to develop critical thinking and problem solving skills. PBL has been used since 1996 in a Bachelor of Nursing course at a New Zealand tertiary institution, and several modifications have been made to foster effective learning. The 'pure' PBL process has been adapted to move students gradually from teacher direction to taking responsibility for their learning. This has provided the opportunity for students to develop critical thinking, problem solving, information retrieval and evaluation skills, and group process skills over an 18-week period. Because rigorous evaluation of these changes had not been formally undertaken, the purpose of this study was to evaluate how the current format was developing students' understanding and integration of knowledge. Two cycles of the action research method (Cardno and Piggot-Irvine, 1994) were used, involving 4 lecturers and 17 students. Data was collected both quantitatively and qualitatively over a 16-week period. Findings indicated the importance of: explaining the purpose and process of PBL; communicating in detail the role of both students and lecturers; keeping communication lines open; addressing timetabling issues and valuing this method of learning for nursing practice. Implications for nursing education are addressed.
Problem based learning to improve proportional reasoning of students in mathematics learning
Misnasanti, Utami, Ratna Widianti; Suwanto, Fevi Rahmawati
2017-08-01
This paper reviews about the using of Problem Based Learning (PBL) to improve proportional reasoning of students in mathematics learning. Mathematics is one of the subjects at school which generally has a goal to help students preparing themselves in this growth century. To achieve the goal of mathematics learning, student's good reasoning is needed as the base of mathematics itself. This reasoning is an ability to think through logic ideas about mathematics concept. One of reasoning mathematics ability is the proportional reasoning. Proportional reasoning is knowing the multiplicative relationship between the base ratio and the proportional situation to which it's applied. Proportional reasoning is important to have by students in learning mathematics. Many topics within the school mathematics require knowledge and understanding of ratio and proportion, for examples problem solving and calculation activities in domains involving scale, probability, percent, rate, trigonometry, equivalence, measurement, the geometry of plane shapes, algebra are assisted through ratio and proportion knowledge. But, the mastership of proportional reasoning ability, of course, can't be apart from teacher's role. In learning, a teacher has to choose and apply the right model so that it can improve the proportional reasoning ability of students. One of the alternative ways which could be applied to improve proportional reasoning ability of students is by applying PBL Model. Applying PBL which based on problem indirectly has trained students to solve every problem in front of them. Thus, applying PBL can improve mathematics proportional reasoning of students in mathematics learning.
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
Problems Implementing Problem-Based Learning by a Private Malaysian University
Chan Chang Tik
2014-01-01
In this case study the focus is on lecturers’ readiness in the design of PBL problems and to facilitate students’ learning. This paper also looks into students’ readiness in terms of acquiring metacognitive skills and collaborating in group to solve PBL problems. Problems encountered by both lecturers and students are discussed in the context of the chosen private Malaysian university.
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.…
Problems Implementing Problem-Based Learning by a Private Malaysian University
Directory of Open Access Journals (Sweden)
Chan Chang Tik
2014-06-01
Full Text Available In this case study the focus is on lecturers’ readiness in the design of PBL problems and to facilitate students’ learning. This paper also looks into students’ readiness in terms of acquiring metacognitive skills and collaborating in group to solve PBL problems. Problems encountered by both lecturers and students are discussed in the context of the chosen private Malaysian university.
New journal: Journal of Problem Based Learning in Higher
Directory of Open Access Journals (Sweden)
Thomas Ryberg
2012-07-01
Full Text Available Kære kolleger Hermed en kort notits om, at der netop er blevet lanceret en ny international open access journal, som har stærke rødder i dansk uddannelsestradition og forskning og dermed også skulle have bred interesse for flere danske forsknings- og uddannelsesmiljøer. Tidsskriftet hedder ’Journal of Problem Based Learning in Higher Education’ og er således specielt dedikeret til forskningsartikler, der vedrører de lange og mellemlange videregående uddannelser. Tidsskriftets fokus er Problem Based Learning, eller det, der i en dansk kontekst, kendes bedre som problemorienteret projektarbejde/projektpædagogik. Begrebet Problem Based Learning/Problembaseret Læring kan dog også forstås bredere som en mere studenter-centreret pædagogik, hvor der i forbindelse med kurser tages udgangspunkt i og arbejdes med problemer som udgangspunkt for læring; hvor der arbejdes med cases, eller hvor de studerende aktiveres gennem f.eks. projektforløb. De mere specifikke fokus- og interesseområder kan man dog læse mere om i den vedhæftede flyer, som alle er velkomne til at cirkulere til evt. interesserede kolleger. Særlig interessant for læsere og forfattere i LOM er naturligvis, at redaktionen er interesserede i artikler, der involverer brugen af IKT og medier i forbindelse med Problembaseret Læring og problemorienteret projektarbejde. Vi forestiller os, at artikler udgivet i LOM, der omhandler dette, med fordel kunne viderebearbejdes til et internationalt publikum. Man kan læse mere, om tidskriftet, fokus og guidelines på adressen: http://ojs.statsbiblioteket.dk/index.php/pbl Vi håber at mange af LOMs læsere og forfatter også vil være interesseret i dette nye tidsskrift, og hvis nogle skulle have spørgsmål eller kommentarer er de velkomne til at kontakte: Thomas Ryberg (ryberg@hum.aau.dk
New journal: Journal of Problem Based Learning in Higher
Directory of Open Access Journals (Sweden)
Thomas Ryberg
2012-10-01
Full Text Available Kære kolleger Hermed en kort notits om, at der netop er blevet lanceret en ny international open access journal, som har stærke rødder i dansk uddannelsestradition og forskning og dermed også skulle have bred interesse for flere danske forsknings- og uddannelsesmiljøer. Tidsskriftet hedder ’Journal of Problem Based Learning in Higher Education’ og er således specielt dedikeret til forskningsartikler, der vedrører de lange og mellemlange videregående uddannelser. Tidsskriftets fokus er Problem Based Learning, eller det, der i en dansk kontekst, kendes bedre som problemorienteret projektarbejde/projektpædagogik. Begrebet Problem Based Learning/Problembaseret Læring kan dog også forstås bredere som en mere studenter-centreret pædagogik, hvor der i forbindelse med kurser tages udgangspunkt i og arbejdes med problemer som udgangspunkt for læring; hvor der arbejdes med cases, eller hvor de studerende aktiveres gennem f.eks. projektforløb. De mere specifikke fokus- og interesseområder kan man dog læse mere om i den vedhæftede flyer, som alle er velkomne til at cirkulere til evt. interesserede kolleger. Særlig interessant for læsere og forfattere i LOM er naturligvis, at redaktionen er interesserede i artikler, der involverer brugen af IKT og medier i forbindelse med Problembaseret Læring og problemorienteret projektarbejde. Vi forestiller os, at artikler udgivet i LOM, der omhandler dette, med fordel kunne viderebearbejdes til et internationalt publikum. Man kan læse mere, om tidskriftet, fokus og guidelines på adressen: http://ojs.statsbiblioteket.dk/index.php/pbl Vi håber at mange af LOMs læsere og forfatter også vil være interesseret i dette nye tidsskrift, og hvis nogle skulle have spørgsmål eller kommentarer er de velkomne til at kontakte: Thomas Ryberg (ryberg@hum.aau.dk
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
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Gemma A Maters
Full Text Available 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
Huang, Yueh-Min; Liu, Ming-Chi; Chen, Nian-Shing; Kinshuk; Wen, Dunwei
2014-01-01
Web-based information problem-solving has been recognised as a critical ability for learners. However, the development of students' abilities in this area often faces several challenges, such as difficulty in building well-organised knowledge structures to support complex problems that require higher-order skills (e.g., system thinking). To…
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
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...... instance in the benchmark data set from the second international timetabling competition....
Directory of Open Access Journals (Sweden)
Yan Sun
2015-01-01
Full Text Available We explore a freight routing problem wherein the aim is to assign optimal routes to move commodities through a multimodal transportation network. This problem belongs to the operational level of service network planning. The following formulation characteristics will be comprehensively considered: (1 multicommodity flow routing; (2 a capacitated multimodal transportation network with schedule-based rail services and time-flexible road services; (3 carbon dioxide emissions consideration; and (4 a generalized costs optimum oriented to customer demands. The specific planning of freight routing is thus defined as a capacitated time-sensitive multicommodity multimodal generalized shortest path problem. To solve this problem systematically, we first establish a node-arc-based mixed integer nonlinear programming model that combines the above formulation characteristics in a comprehensive manner. Then, we develop a linearization method to transform the proposed model into a linear one. Finally, a computational experiment from the Chinese inland container export business is presented to demonstrate the feasibility of the model and linearization method. The computational results indicate that implementing the proposed model and linearization method in the mathematical programming software Lingo can effectively solve the large-scale practical multicommodity multimodal transportation routing problem.
Investing in practice: enquiry- and problem-based learning.
Long, G; Grandis, S; Glasper, E A
Enquiry-based learning (EBL) and problem-based learning (PBL) are two similar methods of educating nurses and midwives which have been recommended by the UKCC in its new report 'Fitness for Practice' (UKCC, 1999). The integration of theory and practice within the student programme is the key to bridging the theory/practice gap. The incorporation of EBL and PBL into the curriculum may help resolve this gap. As these methods of education foster learning through the use of real client scenarios it is important to stress that the partnership between clinical and academic staff is of paramount importance. This article explores EBL and PBL from the practitioner's perspective and examines some of the factors necessary for its successful implementation.
Nursing problem-based learning activity: song writing and singing.
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.
Canale, N.; Griffiths, MD; Vieno, A.; Siciliano, V; Molinaro, S
2016-01-01
Aims: The primary aim of the present study was to understand the impact of online gambling on gambling problems in a large-scale nationally representative sample of Italian youth, and to identify and then further examine a subgroup of online gamblers who reported higher rates of gambling problems. Design: Data from the ESPAD®Italia2013 (European School Survey Project on Alcohol and Other Drugs) Study were used for analyses of adolescent Internet gambling. Setting: Self-administered questionna...
Twelve tips for constructing problem-based learning cases.
Azer, Samy A; Peterson, Ray; Guerrero, Anthony P S; Edgren, Gudrun
2012-01-01
One of the key elements for introducing a problem-based learning (PBL) programme is constructing good PBL cases. Good cases should reflect the educational principles of PBL including (a) integration of basic and clinical sciences together with professionalism and psychosocial components, (b) encouragement of discussion of cognitive domains such as identification of problems, generation of hypotheses, construction of an enquiry plan, weighing evidence for and against each hypothesis, interpretation of findings, construction of mechanisms, using evidence to refine the hypothesis and construction of a management plan, (c) encouragement of discussion of cases in small groups with an emphasis on student-centred learning, (d) promotion of collaborative learning and contribution of students to the case discussion and (e) encouragement of teamwork and self-directed learning strategies. Despite the importance of construction of good PBL cases to the success of a PBL programme, the art of construction of these cases is understudied or described in the literature. Based on our experience in PBL and evidence from literature, we described 12 tips for constructing good PBL cases. Constructing good PBL cases is an art that necessitates teamwork and input from several different disciplines. Cases should be constructed using a template reflecting the educational objectives of the programme. This approach will ensure optimum learning outcomes and consistency in the design and delivery of cases.
Facilitating problem based learning in an online biology laboratory course
Wesolowski, Meredith C.
Online instruction offers many benefits to underserved populations in higher education, particularly increased access. However, incorporation of preferred pedagogical methods, particularly those involving student collaboration, can be more difficult to facilitate in online courses due to geographic separation. In the area of laboratory science education, there is a strong argument for use of constructivist, collaborative pedagogy to promote many facets of student learning. This EPP describes the process used to develop two problem based learning (PBL) laboratory activities based on recommendations found in the literature, their incorporation into an online biology laboratory science course (BIO101) and their impact on student achievement and critical thinking skills. Data analysis revealed a high level of achievement within the study semester. In addition, use of synchronous group discussions as part of the PBL framework resulted in a broad range of discussions reflective of successful problem solving interactions described in the literature. Together, these suggest a observed benefit from incorporation of PBL in this online course. In addition, specific areas for modification were identified as potential future improvements.
Riper, H.; Kramer, J.; Keuken, M.; Smit, F.; Schippers, G.; Cuijpers, P.
2008-01-01
BACKGROUND: Web-based self-help interventions for problem drinking are coming of age. They have shown promising results in terms of cost-effectiveness, and they offer opportunities to reach out on a broad scale to problem drinkers. The question now is whether certain groups of problem drinkers
Using Wavelet Bases to Separate Scales in Quantum Field Theory
Michlin, Tracie L.
This thesis investigates the use of Daubechies wavelets to separate scales in local quantum field theory. Field theories have an infinite number of degrees of freedom on all distance scales. Quantum field theories are believed to describe the physics of subatomic particles. These theories have no known mathematically convergent approximation methods. Daubechies wavelet bases can be used separate degrees of freedom on different distance scales. Volume and resolution truncations lead to mathematically well-defined truncated theories that can be treated using established methods. This work demonstrates that flow equation methods can be used to block diagonalize truncated field theoretic Hamiltonians by scale. This eliminates the fine scale degrees of freedom. This may lead to approximation methods and provide an understanding of how to formulate well-defined fine resolution limits.
Large scale stochastic inventory routing problems with split delivery and service level constraints
Y. Yu (Yugang); C. Chu (Chengbin); H.X. Chen (Haoxun); F. Chu (Feng)
2012-01-01
textabstractA stochastic inventory routing problem (SIRP) is typically the combination of stochastic inventory control problems and NP-hard vehicle routing problems, which determines delivery volumes to the customers that the depot serves in each period, and vehicle routes to deliver the volumes.
Y. Yu (Yugang); C. Chu (Chengbin); H.X. Chen (Haoxun); F. Chu (Feng)
2010-01-01
textabstractA stochastic inventory routing problem (SIRP) is typically the combination of stochastic inventory control problems and NP-hard vehicle routing problems, for a depot to determine delivery volumes to its customers in each period, and vehicle routes to distribute the delivery volumes. This
Toward wafer scale fabrication of graphene based spin valve devices.
Avsar, Ahmet; Yang, Tsung-Yeh; Bae, Sukang; Balakrishnan, Jayakumar; Volmer, Frank; Jaiswal, Manu; Yi, Zheng; Ali, Syed Rizwan; Güntherodt, Gernot; Hong, Byung Hee; Beschoten, Bernd; Özyilmaz, Barbaros
2011-06-08
We demonstrate injection, transport, and detection of spins in spin valve arrays patterned in both copper based chemical vapor deposition (Cu-CVD) synthesized wafer scale single layer and bilayer graphene. We observe spin relaxation times comparable to those reported for exfoliated graphene samples demonstrating that chemical vapor deposition specific structural differences such as nanoripples do not limit spin transport in the present samples. Our observations make Cu-CVD graphene a promising material of choice for large scale spintronic applications.
Medical image classification based on multi-scale non-negative sparse coding.
Zhang, Ruijie; Shen, Jian; Wei, Fushan; Li, Xiong; Sangaiah, Arun Kumar
2017-05-27
With the rapid development of modern medical imaging technology, medical image classification has become more and more important in medical diagnosis and clinical practice. Conventional medical image classification algorithms usually neglect the semantic gap problem between low-level features and high-level image semantic, which will largely degrade the classification performance. To solve this problem, we propose a multi-scale non-negative sparse coding based medical image classification algorithm. Firstly, Medical images are decomposed into multiple scale layers, thus diverse visual details can be extracted from different scale layers. Secondly, for each scale layer, the non-negative sparse coding model with fisher discriminative analysis is constructed to obtain the discriminative sparse representation of medical images. Then, the obtained multi-scale non-negative sparse coding features are combined to form a multi-scale feature histogram as the final representation for a medical image. Finally, SVM classifier is combined to conduct medical image classification. The experimental results demonstrate that our proposed algorithm can effectively utilize multi-scale and contextual spatial information of medical images, reduce the semantic gap in a large degree and improve medical image classification performance. Copyright © 2017 Elsevier B.V. All rights reserved.
Dentists reflect on their problem-based education and professional satisfaction.
Bengmark, D; Nilner, M; Rohlin, M
2012-02-01
To determine the way in which Malmö University dental graduates perceive their problem-based dental education and evaluate their professional satisfaction. The first five cohorts (graduating in years 1995-1999) of the problem-based curriculum were invited to participate. Of 166 graduates, 77% responded to a questionnaire comprising 20 questions on aspects of their dental education, professional situations and interest in postgraduate education. They were asked to rank their perception of their dental education and satisfaction with their professional situation on a visual analogue scale (VAS) with endpoints ranging from 'Not at all' (1) to 'Very well' (10). For other statements, the markings were made on a Likert scale from 1 (not important/not satisfied) to 5 (very important/very satisfied). There were also open-ended questions. Most respondents perceived their education to prepare them well for a career in dentistry (median score VAS 8), and 90% rated above six on a VAS for their professional satisfaction as dentists. Importance and satisfaction were highly correlated with principles of the curriculum: holistic view, oral health, lifelong learning, integration between theory and clinic, and clinical competence. Forty-five per cent of the graduates noted the problem-based learning approach as the most valuable asset of their education, and 19% cited training in oral surgery as a deficit. Of the respondents, 77% expressed interest in specialist training and 55% in research education. Problem-based education was perceived to prepare graduates well for their profession, and their professional satisfaction was high. © 2011 John Wiley & Sons A/S.
Rui, Zeng; Rong-Zheng, Yue; Hong-Yu, Qiu; Jing, Zeng; Xue-Hong, Wan; Chuan, Zuo
2015-01-01
Background Problem-based learning (PBL) is a pedagogical approach based on problems. Specifically, it is a student-centered, problem-oriented teaching method that is conducted through group discussions. The aim of our study is to explore the effects of PBL in diagnostic teaching for Chinese medical students. Methods A prospective, randomized controlled trial was conducted. Eighty junior clinical medical students were randomly divided into two groups. Forty students were allocated to a PBL group and another 40 students were allocated to a control group using the traditional teaching method. Their scores in the practice skills examination, ability to write and analyze medical records, and results on the stage test and behavior observation scale were compared. A questionnaire was administered in the PBL group after class. Results There were no significant differences in scores for writing medical records, content of interviewing, physical examination skills, and stage test between the two groups. However, compared with the control group, the PBL group had significantly higher scores on case analysis, interviewing skills, and behavioral observation scales. Conclusion The questionnaire survey revealed that PBL could improve interest in learning, cultivate an ability to study independently, improve communication and analytical skills, and good team cooperation spirit. However, there were some shortcomings in systematization of imparting knowledge. PBL has an obvious advantage in teaching with regard to diagnostic practice. PMID:25848334
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.
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…
Double inflation: A possible resolution of the large-scale structure problem
Energy Technology Data Exchange (ETDEWEB)
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 ..cap omega.. = 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 approx.100 Mpc, while the small-scale structure over less than or equal to 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.
Evaluating problem-based learning in a multilingual student population.
Connolly, C; Seneque, M
1999-10-01
The University of Natal Medical School in South Africa provides training for a student body composed of two groups: one with English as a first language and the other with an African language as a first language and English as the second. A new methodology was developed to evaluate an innovative course using modified problem-based learning techniques in this heterogeneous environment. The learning model proposed required achieving a balance of three components: content, enquiry/learning process and social interaction/group process. A multidimensional system, felt to be consistent with this educational philosophy, was developed using seven different quantitative and qualitative techniques. The University of Natal Medical School. First-year multilingual medical students. The results revealed that social interaction was highly successful in reducing barriers between the student groups and between students and facilitators. However, the emphasis on group participation may have overshadowed the enquiry process, leading to superficial discussions of problems and feelings of repetitiveness. During the course students and facilitators expressed concern that the innovative assessments used did not assess the course content adequately. While the group presentations and projects were useful exercises for consolidation and group interaction, they did not enable facilitators to identify struggling students. The outcome of the evaluation stressed the need of achieving an appropriate balance both in the curriculum and assessments of the three components of the learning model, particularly in a setting where student backgrounds and language ability differ. Multidimensional methodology is needed for effective evaluation that promotes critical reflection.
Optimal source localization problem based on TOA measurements
Directory of Open Access Journals (Sweden)
Rosić Maja
2017-01-01
Full Text Available Determining an optimal emitting source location based on the time of arrival (TOA measurements is one of the important problems in Wireless Sensor Networks (WSNs. The nonlinear least-squares (NLS estimation technique is employed to obtain the location of an emitting source. This optimization problem has been formulated by the minimization of the sum of squared residuals between estimated and measured data as the objective function. This paper presents a hybridization of Genetic Algorithm (GA for the determination of the global optimum solution with the local search Newton-Raphson (NR method. The corresponding Cramer-Rao lower bound (CRLB on the localization errors is derived, which gives a lower bound on the variance of any unbiased estimator. Simulation results under different signal-to-noise-ratio (SNR conditions show that the proposed hybrid Genetic Algorithm-Newton-Raphson (GA-NR improves the accuracy and efficiency of the optimal solution compared to the regular GA. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR32028
Clustering based hybrid approach for facility location problem
Directory of Open Access Journals (Sweden)
Ashish Sharma
2017-12-01
Full Text Available The main objective of facility location problem is the utilization of the facility by maximum number of possible customers so that the profit is maximized. For instance, in some services like wireless sensor networks, Wi-Fi, repeaters, etc., where the service area is limited, some specific equipment is installed in such a way that it could be used by maximum number of users. Here, the number of users for a particular facility is optimized with the help of clustering technique. The study develops a model for facility allocation problem. For the solution algorithm, a hybrid approach which is based on clustering and mixed integer linear programming (MILP is proposed. The proposed method consists of two parts where in the first part, the K-means clustering technique is used and in the second part, for each cluster an MILP technique is implemented so that the facility which yields the maximum profit is obtained. Numerical examples for clustering and without clustering are presented. Analysis shows that due to clustering the average distance between facility and customer is significantly reduced.
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.
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
Even number of positive solutions for 3nth order three-point boundary value problem on time scales
Directory of Open Access Journals (Sweden)
K. Prasad
2011-12-01
Full Text Available We establish the existence of at least two positive solutions for the 3nth order three-point boundary value problem on time scales by using Avery-Henderson fixed point theorem. We also establish the existence of at least 2m positive solutions for an arbitrary positive integer m.
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)
Integrated Design Process in Problem-Based Learning
DEFF Research Database (Denmark)
Knudstrup, Mary-Ann
2004-01-01
and the method that are developed during the semester when working with an Integrated Design Process combining architecture, design, functional aspects, energy consumption, indoor environment, technology, and construction. I will emphasize the importance of working with different tools in the design process, e.......g. the computer as a tool for designing and optimising the building. I will also consider the dilemma of the Integrated Design Process in Problem Based Learning that emerges when the number of courses in the learning model, as is often the case, clashes with the demand for time and scope for reflection which......This article reports and reflects on the learning achievements and the educational experiences in connection with the first years of the curriculum in Architecture at Aalborg University ?s Civil Engineer Education in Architecture & Design. In the article I will focus on the learning activity...
An electronic study guide for problem-based learning.
Mooney, G A; Bligh, J G; Leinster, S F; Warenius, H M
1995-11-01
This paper describes the development and structure of an Electronic Study Guide for Oncology (LETSGO) for undergraduate medical students. LETSGO is aimed at clinical students learning about cancer. The subject of the guide is breast cancer and learning objectives cover structure and function, behavioural science, public health and epidemiology and professional and personal values. LETSGO is designed to follow the steps used in problem-based learning. The student is encouraged to carry out individual brainstorming around cases with the issues identified acting as the first step in an educational audit loop. Clear definition of prior knowledge is available by way of interactive features, and hyper-text links to core text and diagrams (including microscopic sections) precede definition of both broad aims and objectives for the module and specific objectives for assessment purposes. Core knowledge is available via hyper-text links. Assessment has three components: open ended questions asking for free text responses linking to 'model' answers; extended matching items linking to 'model' answers and providing peer-referenced feedback as a bar-chart distribution, and an educational audit loop referring back to the original issues identified at the beginning of the package in brainstorming. Clear mapping throughout the guide is a major feature and the student's progress is clearly displayed at each stage of the guide. The program provides dynamic access to the student's existing knowledge base and stimulates new learning based on the student's own learning needs.
Modal-pushover-based ground-motion scaling procedure
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.
Student and tutor perceptions on attributes of effective problems in problem-based learning
N. Sockalingam (Nachamma); J.I. Rotgans (Jerome); H.G. Schmidt (Henk)
2011-01-01
textabstractThis study aimed to identify the attributes that students and tutors associated with effective PBL problems, and assess the extent to which these attributes related to the actual effectiveness of problems. To this end, students and tutors in focus groups were asked to discuss about
Sleep Problems in Children with Autism Spectrum Problems: A Longitudinal Population-Based Study
Sivertsen, Borge; Posserud, Maj-Britt; Gillberg, Christopher; Lundervold, Astri J.; Hysing, Mari
2012-01-01
This study examined the prevalence and chronicity of sleep problems in children who manifest problems believed to be typical of Autism Spectrum Disorders (ASD). Using data from a longitudinal total population study, symptoms of ASD, insomnia and potential explanatory factors were assessed at ages 7-9 and 11-13. Children were included in a group…
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.
Directory of Open Access Journals (Sweden)
Rui Z
2015-03-01
Full Text Available Zeng Rui,1,* Yue Rong-Zheng,2,* Qiu Hong-Yu,2 Zeng Jing,3 Wan Xue-Hong,3 Zuo Chuan41Department of Cardiovascular Diseases, 2Department of Nephrology, 3Department of Internal Medicine, 4Department of Rheumatology and Immunology, West China Hospital, School of Clinical Medicine, Sichuan University, Chengdu, People's Republic of China*These author contributed equally to this work and should both be considered first authorsBackground: Problem-based learning (PBL is a pedagogical approach based on problems. Specifically, it is a student-centered, problem-oriented teaching method that is conducted through group discussions. The aim of our study is to explore the effects of PBL in diagnostic teaching for Chinese medical students.Methods: A prospective, randomized controlled trial was conducted. Eighty junior clinical medical students were randomly divided into two groups. Forty students were allocated to a PBL group and another 40 students were allocated to a control group using the traditional teaching method. Their scores in the practice skills examination, ability to write and analyze medical records, and results on the stage test and behavior observation scale were compared. A questionnaire was administered in the PBL group after class.Results: There were no significant differences in scores for writing medical records, content of interviewing, physical examination skills, and stage test between the two groups. However, compared with the control group, the PBL group had significantly higher scores on case analysis, interviewing skills, and behavioral observation scales.Conclusion: The questionnaire survey revealed that PBL could improve interest in learning, cultivate an ability to study independently, improve communication and analytical skills, and good team cooperation spirit. However, there were some shortcomings in systematization of imparting knowledge. PBL has an obvious advantage in teaching with regard to diagnostic practice
[Problem-based learning, a comparison in the acquisition of transversal competencies].
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.
Problem-Oriented Corporate Knowledge Base Models on the Case-Based Reasoning Approach Basis
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.
Tucker, Graeme; Adams, Robert; Wilson, David
2013-01-01
Purpose A number of previous studies have shown inconsistencies between sub-scale scores and component summary scores using traditional scoring methods of the SF-36 version 1. This study addresses the issue in Version 2 and asks if the previous problems of disagreement between the eight SF-36 Version 1 sub-scale scores and the Physical and Mental Component Summary persist in version 2. A second study objective is to review the recommended scoring methods for the creation of factor scoring weights and the effect on producing summary scale scores Methods The 2004 South Australian Health Omnibus Survey dataset was used for the production of coefficients. There were 3,014 observations with full data for the SF-36. Data were analysed in LISREL V8.71. Confirmatory factor analysis models were fit to the data producing diagonally weighted least squares estimates. Scoring coefficients were validated on an independent dataset, the 2008 South Australian Health Omnibus Survey. Results Problems of agreement were observed with the recommended orthogonal scoring methods which were corrected using confirmatory factor analysis. Conclusions Confirmatory factor analysis is the preferred method to analyse SF-36 data, allowing for the correlation between physical and mental health. PMID:23593428
SCALE Modeling of Selected Neutronics Test Problems within the OECD UAM LWR’s Benchmark
Directory of Open Access Journals (Sweden)
Luigi Mercatali
2013-01-01
Full Text Available The OECD UAM Benchmark was launched in 2005 with the objective of determining the uncertainty in the simulation of Light Water Reactors (LWRs system calculations at all the stages of the coupled reactor physics—thermal hydraulics modeling. Within the framework of the “Neutronics Phase” of the Benchmark the solutions of some selected test cases at the cell physics and lattice physics levels are presented. The SCALE 6.1 code package has been used for the neutronics modeling of the selected exercises. Sensitivity and Uncertainty analysis (S/U based on the generalized perturbation theory has been performed in order to assess the uncertainty of the computation of some selected reactor integral parameters due to the uncertainty in the basic nuclear data. As a general trend, it has been found that the main sources of uncertainty are the 238U (n, and the 239Pu nubar for the UOX- and the MOX-fuelled test cases, respectively. Moreover, the reference solutions for the test cases obtained using Monte Carlo methodologies together with a comparison between deterministic and stochastic solutions are presented.
PROBLEM SOLVING IN SCHOOL MATHEMATICS BASED ON HEURISTIC STRATEGIES
NOVOTNÁ, Jarmila; EISENMANN, Petr; PŘIBYL, Jiří; ONDRUŠOVÁ, Jiřina; BŘEHOVSKÝ, Jiří
2014-01-01
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-te...
A Percolation‐Based Approach to Scaling Infiltration and Evapotranspiration
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Allen G. Hunt
2017-02-01
Full Text Available Optimal flow paths obtained from percolation theory provide a powerful tool that can be used to characterize properties associated with flow such as soil hydraulic conductivity, as well as other properties influenced by flow connectivity and topology. A recently proposed scaling theory for vegetation growth appeals to the tortuosity of optimal paths from percolation theory to define the spatio‐temporal scaling of the root radial extent (or, equivalently, plant height. Root radial extent measures the maximum horizontal distance between a plant shoot and the root tips. We apply here the same scaling relationship to unsteady (horizontal flow associated with plant transpiration. The pore‐scale travel time is generated from the maximum flow rate under saturated conditions and a typical pore size. At the field‐scale, the characteristic time is interpreted as the growing season duration, and the characteristic length is derived from the measured evapotranspiration in that period. We show that the two scaling results are equivalent, and they are each in accord with observed vegetation growth limits, as well as with actual limiting transpiration values. While the conceptual approach addresses transpiration, most accessed data are for evapotranspiration. The equivalence of the two scaling approaches suggests that, if horizontal flow is the dominant pathway in plant transpiration, horizontal unsteady flow follows the same scaling relationship as root growth. Then, we propose a corresponding scaling relationship to vertical infiltration, a hypothesis which is amenable to testing using infiltration results of Sharma and co‐authors. This alternate treatment of unsteady vertical flow may be an effective alternative to the commonly applied method based on the diffusion of water over a continuum as governed by Richards’ equation.
Detecting Internal Control Problems Based on COSO and Islamic Perspective: Case on SMEs
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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
Team-Based Complex Problem Solving: A Collective Cognition Perspective
Hung, Woei
2013-01-01
Today, much problem solving is performed by teams, rather than individuals. The complexity of these problems has exceeded the cognitive capacity of any individual and requires a team of members to solve them. The success of solving these complex problems not only relies on individual team members who possess different but complementary expertise,…
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.
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...
Solving Large-Scale QAP Problems in Parallel with the Search
DEFF Research Database (Denmark)
Clausen, Jens; Brüngger, A.; Marzetta, A.
1998-01-01
in combining problem-specific knowledge for the quadratic assignment problem (QAP) with the raw computing power offered by contemporary parallel hardware by using the library of parallel search algorithms ZRAM. Solutions of previously unsolved large standard test-instances of the QAP are presented....
New approaches to image processing based failure analysis of nano-scale ULSI devices
Zalevsky, Zeev; Gur, Eran
2013-01-01
New Approaches to Image Processing Based Failure Analysis of Nano-Scale ULSI Devices introduces the reader to transmission and scanning microscope image processing for metal and non-metallic microstructures. Engineers and scientists face the pressing problem in ULSI development and quality assurance: microscopy methods can't keep pace with the continuous shrinking of feature size in microelectronics. Nanometer scale sizes are below the resolution of light, and imaging these features is nearly impossible even with electron microscopes, due to image noise. This book presents novel ""smart"
Large-Scale Constraint-Based Pattern Mining
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…
Energy Technology Data Exchange (ETDEWEB)
Gene Golub; Kwok Ko
2009-03-30
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.
Problem based learning in midwifery--the students' perspective.
Rowan, Catherine J; McCourt, Christine; Beake, Sarah
2008-01-01
Problem based learning (PBL) has been adopted in many settings for the education of health professionals. It has generally been evaluated well by students although much of the literature comes from medical education. The aim of this study was to ascertain the views of student midwives at the beginning and at the end of their programme and three months after graduation about the use of a PBL based programme in midwifery. Eight focus groups were conducted with students whilst undertaking a PBL programme from both a shortened and three year programme across two sites. A questionnaire was sent 3 months after graduation to midwives who had completed the programme. Key themes which emerged from this study were that although students gained skills in information retrieval and critique some did not always feel well prepared for practice. The focus on individual presentations in the tutorial tended to be interpreted as performance rather than discussion in a spirit of enquiry. Students reported being particularly anxious at the beginning of their programme about their learning. They felt that their experience was dependent upon the participation and motivation of the group members.
Exploring a Problem-Based Learning Approach in Pharmaceutics.
McKenzie, Barbara; Brown, Alyson
2017-09-20
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. 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. 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. 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.
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.
An approach towards problem-based learning in virtual space.
Freudenberg, Lutz S; Bockisch, Andreas; Beyer, Thomas
2010-01-01
Problem-based learning (PBL) is an established and efficient approach to sustainable teaching. Here, we describe translation of PBL into the virtual classroom thereby offering novel teaching aspects in the field of Nuclear Medicine. Our teaching approach is implemented on a "moodle" platform and consists of 2 modules: complementary seminar teaching materials and a virtual PBL-classroom, which can be attended via Skype.Over the course of 4 semesters 539 students have accessed our teaching platform. 21 students have participated in the PBL seminar (module 2). After resolving some minor technical difficulties our virtual seminars have evolved into a forum of intense studies, whereby the participating students have learned to become more independent along the workup of the teaching cases. This was reflected in the results of the intra-group presentations and discussions.Quantitative and qualitative evaluation of our moodle-based PBL platform indicates an increasing level of acceptance and enthusiasm by the students. This has initiated discussions about opening our PBL concept to a wider audience within the university and beyond the Nuclear Medicine specialty.
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.
Self-Regulation and Problem Solving Ability in 7E-Learning Cycle Based Goal Orientation
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.
Rocket to Creativity: A Field Experience in Problem-Based and Project-Based Learning
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…
Online Problem-Based and Enquiry-Based Learning in the Training of Educational Psychologists
Bozic, Nick; Williams, Huw
2011-01-01
Over the past 40 years, problem-based learning (PBL) and enquiry-based learning (EBL) approaches have been used in a variety of professional training courses. More recently online versions of these pedagogies have been developed. This paper explains how online PBL and EBL activities have been incorporated into the professional training of…
Impact on the Student Experience of Extending Problem-Based and Enquiry-Based Learning
Reynolds, Rysia; Saxon, David; Benmore, Graham
2006-01-01
This article reports on extended research into the use of enquiry-based learning (EBL) and problem-based learning (PBL) in a human resource management undergraduate programme. The authors have collected and analysed qualitative and quantitative data over a three-year period, some of which have been previously reported (Reynolds and Benmore, 2003,…
Problem-based learning in comparison with lecture-based learning among medical students.
Faisal, Rizwan; Bahadur, Sher; Shinwari, Laiyla
2016-06-01
To compare performance of medical students exposed to problem-based learning and lecture-based learning. The descriptive study was conducted at Rehman Medical College, Peshawar, Pakistan from May 20 to September 20, 2014, and comprised 146 students of 3rd year MBBS who were randomised into two equal groups. One group was taught by the traditional lecture based learning, while problem-based learning was conducted for the other group on the same topic. At the end of sessions, the performance of the two groups was evaluated by one-best type of 50 multiple choice questions. Total marks were 100, with each question carrying 2 marks. SPSS 15 was used for statistical analysis. There were 146 students who were divided into two equal groups of 73(50%) each. The mean score in the group exposed to problem-based learning was 3.2 ± 0.8 while those attending lecture-based learning was 2.7±0.8 (p= 0.0001). Problem-based learning was more effective than lecture based learning in the academic performance of medical students.
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.
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.
Nouri, Hamideh; Anderson, Sharolyn; Sutton, Paul; Beecham, Simon; Nagler, Pamela L.; 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 (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 1.24 m resolution WorldView-3 and a 0.1 m 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.
Scale symmetry breaking from total derivative densities and the cosmological constant problem
Energy Technology Data Exchange (ETDEWEB)
Guendelman, Eduardo I., E-mail: guendel@bgu.ac.il [Department of Physics, Ben-Gurion University, Beer-Sheva (Israel); Nishino, Hitoshi, E-mail: hnishino@csulb.edu [California State University at Long Beach, Long Beach, CA (United States); Rajpoot, Subhash, E-mail: Subhash.Rajpoot@csulb.edu [California State University at Long Beach, Long Beach, CA (United States)
2014-05-01
The use in the action integral of totally divergent densities in generally coordinate invariant theories can lead to interesting mechanisms of spontaneous symmetry breaking of scale invariance. With dependence in the action on a metric independent density Φ, in 4D, we can define Φ=ε{sup μναβ}∂{sub μ}A{sub ναβ} that gives a new interesting mechanism for breaking scale symmetry in 4D theories of gravity plus matter fields, through the A{sub ναβ} equations of motion which lead to an integration constant the breaks the scale symmetry, while introducing terms of the form eGlnK, e being the determinant of the vierbein, G being the Gauss–Bonnet scalar and K being scalar functions of the fields transforming like K→cK (where c is a constant) under a scale transformation. Such a term is invariant only up to a total divergence and therefore leads to breaking of scale invariance due to gravitational instantons. The topological density constructed out of gauge field strengths ε{sup μναβ}F{sub μν}{sup a}F{sub αβ}{sup a} can be coupled to the dilaton field linearly to produce a scale invariant term up to a total divergence. The scale symmetry can be broken by Yang–Mills instantons which lead to a very small vacuum energy for our Universe.
Adaptive Wavelet Scale Selection-based Method for Separating Respiration and Heartbeat in Bio-radars
Directory of Open Access Journals (Sweden)
Hu Xikun
2016-10-01
Full Text Available Extracting periodic heartbeat signals based on the traditional Fourier transform using a noncontact bio-radar is difficult because chest displacements caused by the heart are much smaller than those caused by respiration. Normally, they can be separated using the continuous wavelet transform; however, the miniscule difference of wavelet scale selection under different conditions may influence the separation performance to some extent. To solve this problem, this study proposes a method based on signal-to-noise ratio calibration to adaptively select the Morletdyadic wavelet scales and then separate the heartbeat signal from the respiration one using the selected scales, which can be applied to detect vital signs of different conditions. The experimental results have exhibited the accuracy and feasibility of the proposed method.
Problem-Based Learning for Didactic Presentation to Baccalaureate Nursing Students.
Montenery, Susan
2017-05-01
Nursing judgment is an essential component in the delivery of safe, quality patient care. Nurses must have the knowledge and skills to question authority, make judgments, substantiate evidence, and advocate for the patient. Traditional pedagogy in content-laden courses remains primarily lecture based. Incorporating active strategies to strengthen professional practice is essential. A pilot study assessed senior baccalaureate nursing students' perceptions of problem-based learning (PBL) and their readiness for self-directed learning. In addition, the authors analyzed the relationship between readiness for self-directed learning and course content mastery using PBL. Students completed the Self-directed Learning Readiness Scale, the Problem-Based Learning Environment Inventory, and course content mastery exams. Students reported positive experiences with PBL and readiness for self-directed learning. Readiness for self-directed learning and 2 of 5 exam scores were inversely, significantly related. Students' perceptions of their readiness for self-directed learning did not always correspond with course content mastery. Specifically, some students who perceived themselves as ready for self-directed learning did not perform well on course content exams. This inverse relationship has not been reported by other researchers and brings an interesting perspective to student perceptions and actual performance. Four themes emerged from students' narrative responses: Prepared Me for Real Life Professional Situations, Stimulated My Critical Thinking, Promoted Independent Problem Solving, and Supported Learning Retention. PBL as a pedagogical approach provides opportunities for nursing students to explore their professional independence while attempting to master content.
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...
A Gas Pressure Scale Based on Primary Standard Piston Gauges
Olson, Douglas A.; Driver, R. Greg; Bowers, Walter J.
2010-01-01
The National Institute of Standards and Technology (NIST) has redefined its gas pressure scale, up to 17 MPa, based on two primary standard piston gauges. The primary standard piston gauges are 35.8 mm in diameter and operate from 20 kPa to 1 MPa. Ten secondary standard piston gauges, two each of five series of the Ruska 2465 type, with successively smaller diameters form the scale extending up to 17 MPa. Six of the piston gauges were directly compared to the primary standards to determine th...
Solvability of a nonlinear second order conjugate eigenvalue problem on a time scale
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John M. Davis
2000-01-01
. Values of the parameter λ (eigenvalues are determined for which this problem has a positive solution. The methods used here extend recent results by allowing for a broader class of functions for a(t.
Image-based Exploration of Large-Scale Pathline Fields
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.
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.
Positive solutions to a generalized second-order three-point boundary-value problem on time scales
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Hua Luo
2005-02-01
Full Text Available Let $mathbb{T}$ be a time scale with $0,T in mathbb{T}$. We investigate the existence and multiplicity of positive solutions to the nonlinear second-order three-point boundary-value problem $$displaylines{ u^{Delta abla}(t+a(tf(u(t=0,quad tin[0, T]subset mathbb{T},cr u(0=eta u(eta,quad u(T=alpha u(eta }$$ on time scales $mathbb{T}$, where 0, 0less than $alpha$ less than $frac{T}{eta}$, 0 less than $eta$ less than $frac{T-alphaeta}{T-eta}$ are given constants.
EFFECT OF PROBLEM BASED LEARNING IN COMPARISION WITH LECTURE BASED LEARNING IN FORENSIC MEDICINE
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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.
XRF map identification problems based on a PDE electrodeposition model
Sgura, Ivonne; Bozzini, Benedetto
2017-04-01
In this paper we focus on the following map identification problem (MIP): given a morphochemical reaction-diffusion (RD) PDE system modeling an electrodepostion process, we look for a time t *, belonging to the transient dynamics and a set of parameters \\mathbf{p} , such that the PDE solution, for the morphology h≤ft(x,y,{{t}\\ast};\\mathbf{p}\\right) and for the chemistry θ ≤ft(x,y,{{t}\\ast};\\mathbf{p}\\right) approximates a given experimental map M *. Towards this aim, we introduce a numerical algorithm using singular value decomposition (SVD) and Frobenius norm to give a measure of error distance between experimental maps for h and θ and simulated solutions of the RD-PDE system on a fixed time integration interval. The technique proposed allows quantitative use of microspectroscopy images, such as XRF maps. Specifically, in this work we have modelled the morphology and manganese distributions of nanostructured components of innovative batteries and we have followed their changes resulting from ageing under operating conditions. The availability of quantitative information on space-time evolution of active materials in terms of model parameters will allow dramatic improvements in knowledge-based optimization of battery fabrication and operation.
Address Translation Problems in IMS Based Next Generation Networks
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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.
Equity Conscious Instruction in Problem-based Multilingual Science Classrooms
Wright, Elizabeth
This dissertation examines the instructional and relational moves implemented by an equity-conscious teacher in service of supporting discursive participation among her English Learners specifically in a problem-based science classroom. The research included also examines the evolution of discursive participation among English Learners as well as the nature of collaboration among English Learners and their English Fluent peers. Initial findings suggest that there were productive, unproductive, and problematic responses to the teacher's caring approach. Students saw the teacher as approachable and accessible which resulted in students seeking the teacher out, which in turn meant that the teacher was able to scaffold instruction for her students. Students recognized and appreciated teacher strategies, but did not generally take up or adopt her instructional supports when working with their peers. English Fluent students shielded English Learners from more rigorous participation in an effort to prevent them from feeling uncomfortable. Furthermore, English Learners and their English Fluent peers defined "help" in the context of group work differently. The implications for this work include further addressing the ways in which teachers support and scaffold science instruction, thinking more critically about the ways in which teachers are explicit in modeling instructional strategies, and working with students to better understand the implications of differences in the ways that they define help and collaborate.
Subgradient-based neural networks for nonsmooth nonconvex optimization problems.
Bian, Wei; Xue, Xiaoping
2009-06-01
This paper presents a subgradient-based neural network to solve a nonsmooth nonconvex optimization problem with a nonsmooth nonconvex objective function, a class of affine equality constraints, and a class of nonsmooth convex inequality constraints. The proposed neural network is modeled with a differential inclusion. Under a suitable assumption on the constraint set and a proper assumption on the objective function, it is proved that for a sufficiently large penalty parameter, there exists a unique global solution to the neural network and the trajectory of the network can reach the feasible region in finite time and stay there thereafter. It is proved that the trajectory of the neural network converges to the set which consists of the equilibrium points of the neural network, and coincides with the set which consists of the critical points of the objective function in the feasible region. A condition is given to ensure the convergence to the equilibrium point set in finite time. Moreover, under suitable assumptions, the coincidence between the solution to the differential inclusion and the "slow solution" of it is also proved. Furthermore, three typical examples are given to present the effectiveness of the theoretic results obtained in this paper and the good performance of the proposed neural network.
Method for Solving LASSO Problem Based on Multidimensional Weight
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Chen ChunRong
2017-01-01
Full Text Available In the data mining, the analysis of high-dimensional data is a critical but thorny research topic. The LASSO (least absolute shrinkage and selection operator algorithm avoids the limitations, which generally employ stepwise regression with information criteria to choose the optimal model, existing in traditional methods. The improved-LARS (Least Angle Regression algorithm solves the LASSO effectively. This paper presents an improved-LARS algorithm, which is constructed on the basis of multidimensional weight and intends to solve the problems in LASSO. Specifically, in order to distinguish the impact of each variable in the regression, we have separately introduced part of principal component analysis (Part_PCA, Independent Weight evaluation, and CRITIC, into our proposal. We have explored that these methods supported by our proposal change the regression track by weighted every individual, to optimize the approach direction, as well as the approach variable selection. As a consequence, our proposed algorithm can yield better results in the promise direction. Furthermore, we have illustrated the excellent property of LARS algorithm based on multidimensional weight by the Pima Indians Diabetes. The experiment results show an attractive performance improvement resulting from the proposed method, compared with the improved-LARS, when they are subjected to the same threshold value.
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.
Problem-based Learning in Veterinary Medicine: Advantages and Disadvantages
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Georgeta Rata
2015-10-01
Full Text Available The purpose of the research is to see if Problem-based Learning (PBL can be successfully used in veterinary medicine. Research results show that PBL offers several advantages (it contributes towards the reduction of information overload; it develops generic skills and aptitudes; it facilitates an integrated core curriculum; it facilitates the relevance of curriculum content; it fosters active, deep learning, improved understanding, and retention and development of lifelong learning skills; it is a constructivist approach; it makes the students more responsible for their learning; and it motivates both teachers and students over traditional teaching methods. However, it also has several well recognised disadvantages (it deprives students’ access to a particular inspirational teacher who, in a traditional curriculum, would deliver lectures to a large group; it is difficult and frustrating for the tutors who cannot “teach”; it makes students be unsure about how much self-directed study to do and what information is relevant and useful; it needs more human resources to take part in the tutoring process; it needs more material resources for the students to access simultaneously. The conclusion is that PBL can successfully be used in the teaching of veterinary medicine-related disciplines provided the teachers work on its disadvantages
Problem-based learning online: perceptions of health science students.
Valaitis, Ruta K; Sword, Wendy A; Jones, Bob; Hodges, Andrea
2005-08-01
This qualitative study explored health sciences students' perceptions of their experiences in online problem based learning (PBL) and focused on their views about learning and group process in the online environment. Participants were novices to online learning and highly experienced in PBL, therefore, they could reflect on past face-to-face PBL experiences. Three groups of learners were involved, including undergraduate nursing and midwifery students and graduate students in a neonatal nurse practitioner program. Findings are presented using the six steps of the PBL process (Rideout & Carpio, 2001). Results indicated that it is feasible to conduct PBL online. Students felt that it increased their flexibility for learning, enhanced their ability to deeply process content, and provided access to valuable learning resources. Students experienced a period of adaptation to the online environment, perceived a heavy workload, and had difficulties making group decisions online. In addition to using asynchronous communication, chats (synchronous communication) were valued to support group decision-making online. Students appreciated validation of their online contributions from their peers and wanted clear expectations of what constituted successful tutorial participation from their tutors. Although online PBL can work effectively, tutors and students need to develop online literacy skills to smooth their transition to an online PBL environment.
Integrating Ultrasound Teaching into Preclinical Problem-based Learning.
Tshibwabwa, Eli Tumba; Cannon, Jenifer; Rice, James; Kawooya, Michael G; Sanii, Reza; Mallin, Robert
2016-01-01
The aim is to provide students in the preclinical with ultrasound image interpretation skills. Research question: Are students in smaller groups with access to a combination of lectures and hands-on patient contact most likely to have better ultrasound image interpretation skills, than students in larger groups with only interactive didactic lectures? First-year students at the preclinical Program of the College of Medicine, participated in two 2-h introductory interactive ultrasound sessions. The study comprised two cohorts: 2012/2013 students, who were offered large group teaching (LGT) sessions (control group), and 2013/2014 students, who received the intervention in small group learning problem-based learning (PBL) sessions (experimental group). The overall learning objectives were identical for both groups. The success of the module was evaluated using pre- and post-tests as well as students' feedback. The students in the experimental group showed significantly higher scores in interpretations of images than those in the control group. The experimental group showed achievement of learning outcomes along with higher levels of satisfaction with the module compared to the latter. Posttest knowledge of the basics of ultrasound improved significantly over the pretest in the experimental group. In addition, students' overall satisfaction of the ultrasound module was shown to be higher for the PBL compared to the LGT groups. Small groups in an interactive and PBL setting along with opportunities for hands-on practice and simultaneous visualization of findings on a high definition screen should enhance preclinical student learning of the basics of ultrasound. Despite the potential of ultrasound as a clinical, teaching and learning tool for students in the preclinical years, standardized recommendations have yet to be created regarding its integration into the curricula within academic institutions and clinical medicine. The interactive and PBL is here to stay at the
A Multi-Stage Reverse Logistics Network Problem by Using Hybrid Priority-Based Genetic Algorithm
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.
Reverse convex problems: an approach based on optimality conditions
Directory of Open Access Journals (Sweden)
Ider Tseveendorj
2006-01-01
Full Text Available We present some results concerning reverse convex problems. Global optimality conditions for the problems with a nonsmooth reverse convex constraint are established and convergence of an algorithm in the case of linear program with an additional quadratic reverse convex constraint is studied.
Instructional Design-Based Research on Problem Solving Strategies
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,…
Linkage disequilibrium-based quality control for large-scale genetic studies.
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Paul Scheet
2008-08-01
Full Text Available Quality control (QC is a critical step in large-scale studies of genetic variation. While, on average, high-throughput single nucleotide polymorphism (SNP genotyping assays are now very accurate, the errors that remain tend to cluster into a small percentage of "problem" SNPs, which exhibit unusually high error rates. Because most large-scale studies of genetic variation are searching for phenomena that are rare (e.g., SNPs associated with a phenotype, even this small percentage of problem SNPs can cause important practical problems. Here we describe and illustrate how patterns of linkage disequilibrium (LD can be used to improve QC in large-scale, population-based studies. This approach has the advantage over existing filters (e.g., HWE or call rate that it can actually reduce genotyping error rates by automatically correcting some genotyping errors. Applying this LD-based QC procedure to data from The International HapMap Project, we identify over 1,500 SNPs that likely have high error rates in the CHB and JPT samples and estimate corrected genotypes. Our method is implemented in the software package fastPHASE, available from the Stephens Lab website (http://stephenslab.uchicago.edu/software.html.
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...
Deep Learning-Based Large-Scale Automatic Satellite Crosswalk Classification
Berriel, Rodrigo F.; Lopes, Andre Teixeira; de Souza, Alberto F.; Oliveira-Santos, Thiago
2017-09-01
High-resolution satellite imagery have been increasingly used on remote sensing classification problems. One of the main factors is the availability of this kind of data. Even though, very little effort has been placed on the zebra crossing classification problem. In this letter, crowdsourcing systems are exploited in order to enable the automatic acquisition and annotation of a large-scale satellite imagery database for crosswalks related tasks. Then, this dataset is used to train deep-learning-based models in order to accurately classify satellite images that contains or not zebra crossings. A novel dataset with more than 240,000 images from 3 continents, 9 countries and more than 20 cities was used in the experiments. Experimental results showed that freely available crowdsourcing data can be used to accurately (97.11%) train robust models to perform crosswalk classification on a global scale.
Optimization based inversion method for the inverse heat conduction problems
Mu, Huaiping; Li, Jingtao; Wang, Xueyao; Liu, Shi
2017-05-01
Precise estimation of the thermal physical properties of materials, boundary conditions, heat flux distributions, heat sources and initial conditions is highly desired for real-world applications. The inverse heat conduction problem (IHCP) analysis method provides an alternative approach for acquiring such parameters. The effectiveness of the inversion algorithm plays an important role in practical applications of the IHCP method. Different from traditional inversion models, in this paper a new inversion model that simultaneously highlights the measurement errors and the inaccurate properties of the forward problem is proposed to improve the inversion accuracy and robustness. A generalized cost function is constructed to convert the original IHCP into an optimization problem. An iterative scheme that splits a complicated optimization problem into several simpler sub-problems and integrates the superiorities of the alternative optimization method and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm is developed for solving the proposed cost function. Numerical experiment results validate the effectiveness of the proposed inversion method.
A Look at Problem-Based Learning in High School Classrooms to Promote Student Activism
Baker, Anne-Rose L.
2011-01-01
Problem based learning has more recently become a common term in public education. There is much positive potential when implementing problem based learning at the high school level. Here I review positives while not completely ignoring some of the negatives associated with implementing a problem based learning model at the high school level. More…
From Saying to Doing Interdisciplinary Learning: Is Problem-Based Learning the Answer?
Stentoft, Diana
2017-01-01
Problem-based learning is often characterised as an approach encompassing interdisciplinary learning; however, little attention has been explicitly paid to what a claim of interdisciplinary problem-based learning means in practice. Even less attention has been given to address the consequences of interdisciplinary problem-based learning for…
A novel approach based on preference-based index for interval bilevel linear programming problem.
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.
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.
Analyzing data from a fuzzy rating scale-based questionnaire. A case study.
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.
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.
Directory of Open Access Journals (Sweden)
Rong Jing
2014-01-01
Full Text Available The existing coverage hole boundary detection methods cannot detect large-scale coverage hole boundary in wireless sensor network quickly and efficiently. Aiming at this problem, a boundary detection method for large-scale coverage holes in wireless sensor network based on minimum critical threshold constraint is proposed. Firstly, the optimization problem of minimum critical threshold is highlighted, and its formulaic description is constructed according to probabilistic sensing model. On the basis of this, the distributed gradient information is used to approximately solve the optimization problem. After that, local-scale rough boundary detection algorithm incorporating the minimum critical threshold and its iterative thinning algorithm are proposed according to blocking flow theory. The experimental results show that the proposed method has low computational complexity and network overhead when detecting large-scale coverage hole boundary in wireless sensor network.
Incremental planning to control a blackboard-based problem solver
Durfee, E. H.; Lesser, V. R.
1987-01-01
To control problem solving activity, a planner must resolve uncertainty about which specific long-term goals (solutions) to pursue and about which sequences of actions will best achieve those goals. A planner is described that abstracts the problem solving state to recognize possible competing and compatible solutions and to roughly predict the importance and expense of developing these solutions. With this information, the planner plans sequences of problem solving activities that most efficiently resolve its uncertainty about which of the possible solutions to work toward. The planner only details actions for the near future because the results of these actions will influence how (and whether) a plan should be pursued. As problem solving proceeds, the planner adds new details to the plan incrementally, and monitors and repairs the plan to insure it achieves its goals whenever possible. Through experiments, researchers illustrate how these new mechanisms significantly improve problem solving decisions and reduce overall computation. They briefly discuss current research directions, including how these mechanisms can improve a problem solver's real-time response and can enhance cooperation in a distributed problem solving network.
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.
Cooperative Co-evolution with Formula-based Variable Grouping for Large-Scale Global Optimization.
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 as an effective strategy to decompose the problem into smaller subproblems, each of which can be then 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, i.e., the formulas of objective functions are often known a priori. These formulas of the objective functions provide rich information which can be then used to design an effective variable group method. In this paper, a formulabased 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 " + ", " - ", " × ", " ÷ " and composite operations of basic elementary functions). In FBG, the operations are classified into two classes: one resulting in non-separable 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 inter-dependent. FBG can be applied to any white-box problem easily and can be integrated into a cooperative co-evolution framework. Based on FBG, a novel cooperative co-evolution algorithm with formula-based variable grouping (so-called CCF) is proposed in this paper for decomposing a large-scale white-box problem into several smaller sub-problems and optimizing them
Cauchy problem for Laplace equation: An observer based approach
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.
Providing Pediatric Palliative Care Education Using Problem-Based Learning.
Moody, Karen; McHugh, Marlene; Baker, Rebecca; Cohen, Hillel; Pinto, Priya; Deutsch, Stephanie; Santizo, Ruth O; Schechter, Miriam; Fausto, James; Joo, Pablo
2018-01-01
The Institute of Medicine and the American Academy of Pediatrics has called for improvement in education and training of pediatricians in pediatric palliative care (PPC). Given the shortage of PPC physicians and the immediate need for PPC medical education, this study reports the outcomes of a problem-based learning (PBL) module facilitated by academic general and subspecialty pediatric faculty (non-PPC specialists) to third year medical students. Objectives/Setting: To test the effectiveness of a PPC-PBL module on third year medical students' and pediatric faculty's declarative knowledge, attitudes toward, perceived exposure, and self-assessed competency in PPC objectives. A PBL module was developed using three PPC learning objectives as a framework: define core concepts in palliative care; list the components of a total pain assessment; and describe key principles in establishing therapeutic relationships with patients. A PPC physician and nurse practitioner guided pediatric faculty on facilitating the PPC-PBL. In Part 1, students identified domains of palliative care for a child with refractory leukemia and self-assigned questions to research and present at the follow-up session. In Part 2, students were expected to develop a care plan demonstrating the three PPC objectives. Measures included a knowledge exam and a survey instrument to assess secondary outcomes. Students' declarative knowledge, perceived exposure, and self-assessed competency in all three PPC learning objectives improved significantly after the PPC-PBL, p = 0.002, p 80%). Students and faculty rated palliative care education as "important or very important" at baseline and follow-up. This study suggests that key concepts in PPC can be taught to medical students utilizing a PBL format and pediatric faculty resulting in improved knowledge and self-assessed competency in PPC.
Nano-Scale Devices for Frequency-Based Magnetic Biosensing
2017-01-31
which itself contains a magnetic vortex). Magnetoresistive rectification (which depends on anisotropic magnetoresistance) leads to a voltage ...AFRL-AFOSR-JP-TR-2017-0010 Nano-Scale Devices for Frequency-Based Magnetic Biosensing Peter Metaxas UNIVERSITY OF WESTERN AUSTRALIA Final Report 01...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM-YYYY) 09-02-2017 2. REPORT TYPE
Graph-based linear scaling electronic structure theory.
Niklasson, Anders M N; Mniszewski, Susan M; Negre, Christian F A; Cawkwell, Marc J; Swart, Pieter J; Mohd-Yusof, Jamal; Germann, Timothy C; Wall, Michael E; Bock, Nicolas; Rubensson, Emanuel H; Djidjev, Hristo
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.
Limin, Chen; Van Dooren, Wim; Verschaffel, Lieven
2013-01-01
The goal of the present study is to investigate the relationship between pupils' problem posing and problem solving abilities, their beliefs about problem posing and problem solving, and their general mathematics abilities, in a Chinese context. Five instruments, i.e., a problem posing test, a problem solving test, a problem posing questionnaire,…
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.
Routing and Addressing Problems in Large Metropolitan-Scale Internetworks. ISI Research Report.
Finn, Gregory G.
This report discusses some of the problems and limitations in existing internetwork design for the connection of packet-switching networks of different technologies and presents an algorithm that has been shown to be suitable for internetworks of unbounded size. Using a new form of address and a flat routing mechanism called Cartesian routing,…
A real-time multi-scale 2D Gaussian filter based on FPGA
Luo, Haibo; Gai, Xingqin; Chang, Zheng; Hui, Bin
2014-11-01
Multi-scale 2-D Gaussian filter has been widely used in feature extraction (e.g. SIFT, edge etc.), image segmentation, image enhancement, image noise removing, multi-scale shape description etc. However, their computational complexity remains an issue for real-time image processing systems. Aimed at this problem, we propose a framework of multi-scale 2-D Gaussian filter based on FPGA in this paper. Firstly, a full-hardware architecture based on parallel pipeline was designed to achieve high throughput rate. Secondly, in order to save some multiplier, the 2-D convolution is separated into two 1-D convolutions. Thirdly, a dedicate first in first out memory named as CAFIFO (Column Addressing FIFO) was designed to avoid the error propagating induced by spark on clock. Finally, a shared memory framework was designed to reduce memory costs. As a demonstration, we realized a 3 scales 2-D Gaussian filter on a single ALTERA Cyclone III FPGA chip. Experimental results show that, the proposed framework can computing a Multi-scales 2-D Gaussian filtering within one pixel clock period, is further suitable for real-time image processing. Moreover, the main principle can be popularized to the other operators based on convolution, such as Gabor filter, Sobel operator and so on.
Facilitators' perceptions of problem-based learning and community-based education
Directory of Open Access Journals (Sweden)
Paula P du Rand
2000-02-01
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.
Creative Writing, Problem-Based Learning, and Game-Based Learning Principles
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…