Orazbayev, B B; Orazbayeva, K N; Kurmangaziyeva, L T; Makhatova, V E
2015-01-01
Mathematical equations for the multi-criteria task of the optimisation of chemical engineering systems, for example for the optimisation of working regimes for industrial installations for benzene production, have been formulated and developed, and based on fuzzy mathematical methods, algorithms for their solution have been developed. Since the chemical engineering system, which is being researched, is characterised by multiple criteria and often functions in conditions of uncertainty, the presenting problem is formulated in the form of multi-criteria equations for fuzzy mathematical programming. New mathematical formulations for the problems being solved in a fuzzy environment and heuristic algorithms for their solution have been developed by the modification of various optimisation principles based on fuzzy mathematical methods.
Orazbayev, B. B.; Orazbayeva, K. N.; Kurmangaziyeva, L. T.; Makhatova, V.E.
2015-01-01
Mathematical equations for the multi-criteria task of the optimisation of chemical engineering systems, for example for the optimisation of working regimes for industrial installations for benzene production, have been formulated and developed, and based on fuzzy mathematical methods, algorithms for their solution have been developed. Since the chemical engineering system, which is being researched, is characterised by multiple criteria and often functions in conditions of uncertainty, the presenting problem is formulated in the form of multi-criteria equations for fuzzy mathematical programming. New mathematical formulations for the problems being solved in a fuzzy environment and heuristic algorithms for their solution have been developed by the modification of various optimisation principles based on fuzzy mathematical methods.
Mathematical Modeling of Chemical Stoichiometry
Croteau, Joshua; Fox, William P.; Varazo, Kristofoland
2007-01-01
In beginning chemistry classes, students are taught a variety of techniques for balancing chemical equations. The most common method is inspection. This paper addresses using a system of linear mathematical equations to solve for the stoichiometric coefficients. Many linear algebra books carry the standard balancing of chemical equations as an…
Mathematical modeling a chemical engineer's perspective
Rutherford, Aris
1999-01-01
Mathematical modeling is the art and craft of building a system of equations that is both sufficiently complex to do justice to physical reality and sufficiently simple to give real insight into the situation. Mathematical Modeling: A Chemical Engineer's Perspective provides an elementary introduction to the craft by one of the century's most distinguished practitioners.Though the book is written from a chemical engineering viewpoint, the principles and pitfalls are common to all mathematical modeling of physical systems. Seventeen of the author's frequently cited papers are reprinted to illus
Identification of Chemical Reactor Plant’s Mathematical Model
Directory of Open Access Journals (Sweden)
Pyakillya Boris
2015-01-01
Full Text Available This work presents a solution of the identification problem of chemical reactor plant’s mathematical model. The main goal is to obtain a mathematical description of a chemical reactor plant from experimental data, which based on plant’s time response measurements. This data consists sequence of measurements for water jacket temperature and information about control input signal, which is used to govern plant’s behavior.
Some Chemical Applications of the 'New' Mathematics
Mooney, Arthur
1975-01-01
Indicates how some branches of chemistry lend themselves to interpretation using a modern mathematical approach. Examples include set theory and the periodic table, matrix algebra and determinants and atomic theory, and symmetry and molecular structure. (GS)
Mathematical simulation of plasma-chemical coal conversion
Energy Technology Data Exchange (ETDEWEB)
Messerle, A.V. [Bauman State Technical University, Moscow (Russian Federation)
2004-02-01
A mathematical model that describes the conversion of a coal-dust flow in a cylindrical plasma reactor is presented. The model describes a two-phase (coal particles + air) chemically reacting flow, which propagates in a channel with or without an internal heat source (an electric arc, a plasmatron torch, or exothermic chemical reactions). The model is based on the assumption that the process is quasi-stationary and one-dimensional; coal particles are taken as isothermal, and ash is assumed to be an inert component. The model represents the composition of coals by their organic and mineral constituents. The model was implemented as a pro-ram for personal computers; calculations performed with the use of this program are in satisfactory agreement with experimental data.
Basitere, Moses; Ivala, Eunice
2015-01-01
This paper reports on a study carried out at a University of Technology, South Africa, aimed at identifying the existence of the mathematical knowledge gap and evaluating the intervention designed to bridge the knowledge gap amongst students studying first year mathematics at the Chemical Engineering Extended Curriculum Program (ECP). In this…
A New Mathematical Formulation of the Governing Equations for the Chemical Compositional Simulation
Bekbauov, Bakhbergen E; Berdyshev, Abdumauvlen
2015-01-01
It is the purpose of this work to develop new approach for chemical compositional reservoir simulation, which may be regarded as a sequential method. The development process can be roughly divided into the following two stages: (1) development of a new mathematical formulation for the sequential chemical compositional reservoir simulation, (2) implementation of a sequential solution approach for chemical compositional reservoir simulation based on the formulation described in this paper. This paper addresses the first stage of the development process by presenting a new mathematical formulation of the chemical compositional reservoir flow equations for the sequential simulation. The newly developed mathematical formulation is extended from the model formulation used in existing chemical compositional simulators. During the model development process, it was discovered that the currently used chemical compositional model estimates the adsorption effect on the transport of a component reasonably well but it viol...
Mathematically Reduced Chemical Reaction Mechanism Using Neural Networks
Energy Technology Data Exchange (ETDEWEB)
Ziaul Huque
2007-08-31
This is the final technical report for the project titled 'Mathematically Reduced Chemical Reaction Mechanism Using Neural Networks'. The aim of the project was to develop an efficient chemistry model for combustion simulations. The reduced chemistry model was developed mathematically without the need of having extensive knowledge of the chemistry involved. To aid in the development of the model, Neural Networks (NN) was used via a new network topology known as Non-linear Principal Components Analysis (NPCA). A commonly used Multilayer Perceptron Neural Network (MLP-NN) was modified to implement NPCA-NN. The training rate of NPCA-NN was improved with the GEneralized Regression Neural Network (GRNN) based on kernel smoothing techniques. Kernel smoothing provides a simple way of finding structure in data set without the imposition of a parametric model. The trajectory data of the reaction mechanism was generated based on the optimization techniques of genetic algorithm (GA). The NPCA-NN algorithm was then used for the reduction of Dimethyl Ether (DME) mechanism. DME is a recently discovered fuel made from natural gas, (and other feedstock such as coal, biomass, and urban wastes) which can be used in compression ignition engines as a substitute for diesel. An in-house two-dimensional Computational Fluid Dynamics (CFD) code was developed based on Meshfree technique and time marching solution algorithm. The project also provided valuable research experience to two graduate students.
Chemical Literacy Levels of Science and Mathematics Teacher Candidates
Celik, Suat
2014-01-01
The goal of this study was to investigate Turkish science and mathematics teacher candidates' levels of attainment in chemical literacy. These candidates had all studied the new Turkish chemistry curriculum in high school. The sample of the study consisted of 112 students, who were first-year students in the Department of Secondary Science…
Ge, Hao; Qian, Hong
2017-01-01
This paper studies a mathematical formalism of nonequilibrium thermodynamics for chemical reaction models with N species, M reactions, and general rate law. We establish a mathematical basis for J. W. Gibbs' macroscopic chemical thermodynamics under G. N. Lewis' kinetic law of entire equilibrium (detailed balance in nonlinear chemical kinetics). In doing so, the equilibrium thermodynamics is then naturally generalized to nonequilibrium settings without detailed balance. The kinetic models are represented by a Markovian jumping process. A generalized macroscopic chemical free energy function and its associated balance equation with nonnegative source and sink are the major discoveries. The proof is based on the large deviation principle of this type of Markov processes. A general fluctuation dissipation theorem for stochastic reaction kinetics is also proved. The mathematical theory illustrates how a novel macroscopic dynamic law can emerges from the mesoscopic kinetics in a multi-scale system.
Conceptualising inquiry based education in mathematics
DEFF Research Database (Denmark)
Blomhøj, Morten; Artigue, Michéle
2013-01-01
of inquiry as a pedagogical concept in the work of Dewey (e.g. 1916, 1938) to analyse and discuss its migration to science and mathematics education. For conceptualizing inquiry-based mathematics education (IBME) it is important to analyse how this concept resonates with already well-established theoretical......The terms inquiry-based learning (IBL) and inquiry-based education (IBE) have appeared with increasing frequency in educational policy and curriculum documents related to mathematics and science education over the past decade, indicating a major educational trend. We go back to the origin...... frameworks in mathematics education. Six such frameworks are analysed from the perspective of inquiry: the problem-solving tradition, the Theory of Didactical Situations, the Realistic Mathematics Education programme, the mathematical modelling perspective, the Anthropological Theory of Didactics...
Mesoscopic Kinetic Basis of Macroscopic Chemical Thermodynamics: A Mathematical Theory
Ge, Hao
2016-01-01
From a mathematical model that describes a complex chemical kinetic system of $N$ species and $M$ elementrary reactions in a rapidly stirred vessel of size $V$ as a Markov process, we show that a macroscopic chemical thermodynamics emerges as $V\\rightarrow\\infty$. The theory is applicable to linear and nonlinear reactions, closed systems reaching chemical equilibrium, or open, driven systems approaching to nonequilibrium steady states. A generalized mesoscopic free energy gives rise to a macroscopic chemical energy function $\\varphi^{ss}(\\vx)$ where $\\vx=(x_1,\\cdots,x_N)$ are the concentrations of the $N$ chemical species. The macroscopic chemical dynamics $\\vx(t)$ satisfies two emergent laws: (1) $(\\rd/\\rd t)\\varphi^{ss}[\\vx(t)]\\le 0$, and (2)$(\\rd/\\rd t)\\varphi^{ss}[\\vx(t)]=\\text{cmf}(\\vx)-\\sigma(\\vx)$ where entropy production rate $\\sigma\\ge 0$ represents the sink for the chemical energy, and chemical motive force $\\text{cmf}\\ge 0$ is non-zero if the system is driven under a sustained nonequilibrium chemos...
Computer-Game-Based Tutoring of Mathematics
Ke, Fengfeng
2013-01-01
This in-situ, descriptive case study examined the potential of implementing computer mathematics games as an anchor for tutoring of mathematics. Data were collected from middle school students at a rural pueblo school and an urban Hispanic-serving school, through in-field observation, content analysis of game-based tutoring-learning interactions,…
The mathematical bases for qualitative reasoning
Kalagnanam, Jayant; Simon, Herbert A.; Iwasaki, Yumi
1991-01-01
The practices of researchers in many fields who use qualitative reasoning are summarized and explained. The goal is to gain an understanding of the formal assumptions and mechanisms that underlie this kind of analysis. The explanations given are based on standard mathematical formalisms, particularly on ordinal properties, continuous differentiable functions, and the mathematics of nonlinear dynamic systems.
37 CFR 1.58 - Chemical and mathematical formulae and tables.
2010-07-01
... Provisions The Application § 1.58 Chemical and mathematical formulae and tables. (a) The specification, including the claims, may contain chemical and mathematical formulae, but shall not contain drawings or flow... mathematical formulae must be encoded to maintain the proper positioning of their characters when displayed...
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.
Mathematical Modeling of Tin-Free Chemically-Active Antifouling Paint Behavior
DEFF Research Database (Denmark)
Yebra, Diego Meseguer; Kiil, Søren; Dam-Johansen, Kim
2006-01-01
Mathematical modeling has been used to characterize and validate the working mechanisms of tin-free, chemically-active antifouling (AF) paints. The model-based analysis of performance data from lab-scale rotary experiments has shown significant differences between antifouling technologies...... as regards the biocide leaching and the surface polishing processes. Hence, the modeling framework developed in this work is built so as to describe any generic, chemically-active AF paint through model parameters, the values of which can be obtained or adjusted from relatively fast measurements...
Konakov, S. A.; Krzhizhanovskaya, V. V.
2015-01-01
We developed a mathematical model of Plasma Enhanced Chemical Vapor Deposition (PECVD) of silicon nitride thin films from SiH4-NH3-N2-Ar mixture, an important application in modern materials science. Our multiphysics model describes gas dynamics, chemical physics, plasma physics and electrodynamics. The PECVD technology is inherently multiscale, from macroscale processes in the chemical reactor to atomic-scale surface chemistry. Our macroscale model is based on Navier-Stokes equations for a transient laminar flow of a compressible chemically reacting gas mixture, together with the mass transfer and energy balance equations, Poisson equation for electric potential, electrons and ions balance equations. The chemical kinetics model includes 24 species and 58 reactions: 37 in the gas phase and 21 on the surface. A deposition model consists of three stages: adsorption to the surface, diffusion along the surface and embedding of products into the substrate. A new model has been validated on experimental results obtained with the "Plasmalab System 100" reactor. We present the mathematical model and simulation results investigating the influence of flow rate and source gas proportion on silicon nitride film growth rate and chemical composition.
Dog Mathematics: Exploring Base-4
Kurz, Terri L.; Yanik, H. Bahadir; Lee, Mi Yeon
2016-01-01
Using a dog's paw as a basis for numerical representation, sixth grade students explored how to count and regroup using the dog's four digital pads. Teachers can connect these base-4 explorations to the conceptual meaning of place value and regrouping using base-10.
Bukova-Guzel, Esra; Canturk-Gunhan, Berna
2011-01-01
The purpose of the study is to determine prospective mathematics teachers' views about using computer-based instructional materials in constructing mathematical concepts and to reveal how the sample computer-based instructional materials for different mathematical concepts altered their views. This is a qualitative study involving twelve…
On computer-based assessment of mathematics
Pead, Daniel
2010-01-01
This work explores some issues arising from the widespread use of computer based assessment of Mathematics in primary and secondary education. In particular, it considers the potential of computer based assessment for testing “process skills” and “problem solving”. This is discussed through a case study of the World Class Tests project which set out to test problem solving skills. The study also considers how on-screen “eAssessment” differs from conventional paper tests and how transferri...
Preservice Mathematics Teachers' Perceptions of Drama Based Instruction
Bulut, Neslihan
2016-01-01
The purpose of this study was to determine the perceptions of pre-service mathematics teachers related to drama-based instruction. For this purpose, effects of a drama-based mathematics course on senior class pre-service mathematics teachers' knowledge about drama-based instruction and teacher candidates' competencies for developing and…
A mathematical model of symmetry based on mathematical definition
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Tolerance is imperative for seamless integration of CAD/CAM(Computer Aided Disign/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types, the relations between which are very complicated. In addition, the different principles of tolerance make study of tolerance difficult; and there may be various meanings or interpretation for the same type of tolerance because of the literal definition. In this work, latest unambiguous mathematical definition was applied to study, explain and clarify: (1) the formation and representation of tolerance zone, and (2) the formation and representation of variational elements; after which, the mathematical models of symmetry of different tolerance principles and different interpretations were derived. An example is given to illustrate the application of these models in tolerance analysis.
A mathematical model of symmetry based on mathematical definition
Institute of Scientific and Technical Information of China (English)
刘玉生; 杨将新; 吴昭同; 高曙明
2002-01-01
Tolerance is imperative for seamless integration of CAD/CAM(Computer Aided Disignd/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types, the relations between which are very complicated. In addition, the different principles of tolerance make study of tolerance difficult; and there may be various meanings or interpretation for the same type of tolerance beeanse of the literal definition. In this work, latest unambiguous mathematical definition was applied to study, explain and clarify: ( 1 ) the formation and representation of tolerance zone, and (2) the formation and representation of variational elements ; after which, the mathematical models of syrmmetry of different tolerance principles and different interpretations were derived. An example is given to illustrate the application of these models in tolerance analysis.
The role of mathematical modelling in chemical and food engineering studies
Brandão, Teresa R. S.; Silva, Cristina L. M.
2003-01-01
The role of mathematical modelling in chemical and food engineering studies is briefly and consistently presented. The main goal was to give a short global overview of the relevant aspects involved in modelling processes. Food engineering problems are generally highlighted. It must be emphasised that the following matter should not be analysed in a narrow perspective. The mathematical modelling field, in chemical and food engineering subjects, is very wide and this paper just presents the ...
Mathematical models of thermal and chemical transport in geologic media
Energy Technology Data Exchange (ETDEWEB)
Lai, C.-H.
1985-12-01
Semi-analytical and numerical methods are used to investigate thermal and chemical transport processes in geologic media. The work is divided into two parts: (1) development of semi-analytical models for the analysis of uncoupled isothermal and nonisothermal fluid flow in naturally fractured media, and (2) development of a high resolution numerical code to address coupled nonisothermal chemical transport in geologic media. A semi-analytical model is developed for well test data analysis in naturally fractured reservoirs. A simple approximate analytical solution for pressure buildup and drawdown tests is developed. Methods based on the approximate solution are developed for the evaluation of important reservoir properties. Type curves for nonisothermal fluid flow in naturally fractured media are developed to design injection systems for maximum energy in hydrothermal systems. An accurate finite difference method for the solution of a convection-diffusion type equation is developed. The method is incorporated in a two-dimensional code to investigate free convection in a porous slab and kinetic silica-water reactions in geothermal systems. A multicomponent model considering the variations of pressure, temperature and silica concentration is developed to interpret the evolution of geothermal systems during exploitation.
Mathematical programming solver based on local search
Gardi, Frédéric; Darlay, Julien; Estellon, Bertrand; Megel, Romain
2014-01-01
This book covers local search for combinatorial optimization and its extension to mixed-variable optimization. Although not yet understood from the theoretical point of view, local search is the paradigm of choice for tackling large-scale real-life optimization problems. Today's end-users demand interactivity with decision support systems. For optimization software, this means obtaining good-quality solutions quickly. Fast iterative improvement methods, like local search, are suited to satisfying such needs. Here the authors show local search in a new light, in particular presenting a new kind of mathematical programming solver, namely LocalSolver, based on neighborhood search. First, an iconoclast methodology is presented to design and engineer local search algorithms. The authors' concern about industrializing local search approaches is of particular interest for practitioners. This methodology is applied to solve two industrial problems with high economic stakes. Software based on local search induces ex...
Konakov, S.A.; Krzhizhanovskaya, V.V.
2015-01-01
We developed a mathematical model of Plasma Enhanced Chemical Vapor Deposition (PECVD) of silicon nitride thin films from SiH4-NH3-N2-Ar mixture, an important application in modern materials science. Our multiphysics model describes gas dynamics, chemical physics, plasma physics and electrodynamics.
Biza, Irene; Nardi, Elena; Joel, Gareth
2015-01-01
In this paper we present the results from a study in which 21 mathematics trainee teachers engage with two practice-based tasks in which classroom management interferes with mathematical learning. We investigate the trainees' considerations when they make decisions in classroom situations and how these tasks can trigger their reflections on the…
Jitendra, Asha K.; Nelson, Gena; Pulles, Sandra M.; Kiss, Allyson J.; Houseworth, James
2016-01-01
The purpose of the present review was to evaluate the quality of the research and evidence base for representation of problems as a strategy to enhance the mathematical performance of students with learning disabilities and those at risk for mathematics difficulties. The authors evaluated 25 experimental and quasiexperimental studies according to…
Paterson, Judy; Sneddon, Jamie
2011-01-01
This article reports on the learning conversations between a mathematician and a mathematics educator as they worked together to change the delivery model of a third year discrete mathematics course from a traditional lecture mode to team-based learning (TBL). This change prompted the mathematician to create team tasks which increasingly focused…
Web-Based Implementation of Discrete Mathematics
Love, Tanzy; Keinert, Fritz; Shelley, Mack
2006-01-01
The Department of Mathematics at Iowa State University teaches a freshman-level Discrete Mathematics course with total enrollment of about 1,800 students per year. The traditional format includes large lectures, with about 150 students each, taught by faculty and temporary instructors in two class sessions per week and recitation sections, with…
Mesoscopic kinetic basis of macroscopic chemical thermodynamics: A mathematical theory
Ge, Hao; Qian, Hong
2016-11-01
Gibbs' macroscopic chemical thermodynamics is one of the most important theories in chemistry. Generalizing it to mesoscaled nonequilibrium systems is essential to biophysics. The nonequilibrium stochastic thermodynamics of chemical reaction kinetics suggested a free energy balance equation d F(meso)/d t =Ein-ep in which the free energy input rate Ein and dissipation rate ep are both non-negative, and Ein≤ep . We prove that in the macroscopic limit by merely allowing the molecular numbers to be infinite, the generalized mesoscopic free energy F(meso) converges to φss, the large deviation rate function for the stationary distributions. This generalized macroscopic free energy φss now satisfies a balance equation d φss(x ) /d t =cmf(x ) -σ (x ) , in which x represents chemical concentration. The chemical motive force cmf(x ) and entropy production rate σ (x ) are both non-negative, and cmf(x )≤σ (x ) . The balance equation is valid generally in isothermal driven systems and is different from mechanical energy conservation and the first law; it is actually an unknown form of the second law. Consequences of the emergent thermodynamic quantities and equalities are further discussed. The emergent "law" is independent of underlying kinetic details. Our theory provides an example showing how a macroscopic law emerges from a level below.
Anku, Sitsofe E.
1997-09-01
Using the reform documents of the National Council of Teachers of Mathematics (NCTM) (NCTM, 1989, 1991, 1995), a theory-based multi-dimensional assessment framework (the "SEA" framework) which should help expand the scope of assessment in mathematics is proposed. This framework uses a context based on mathematical reasoning and has components that comprise mathematical concepts, mathematical procedures, mathematical communication, mathematical problem solving, and mathematical disposition.
Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics
Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander
2010-01-01
We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to introduce students to mathematical methods beyond the interface of biology with calculus. Based on ongoing research, and designed to use the project-...
Preservice Teachers Conceptions of Mathematics-Based Software
Kurz, Terri; Middleton, James; Yanik, H. Bahadir
2004-01-01
Preservice teachers do not feel prepared to teach mathematics using technology (Smith & Shotsberger, 2001). To address this issue, we have developed a tool-based categorization of mathematics software and used it to instruct preservice teachers. Changes in thinking that occurred as a result of the course are analyzed primarily using repertory grid…
Language-Based Prior Knowledge and Transition to Mathematics
Dogan-Dunlap, Hamide; Torres, Cristina; Chen, Fan
2005-01-01
The paper provides a college mathematics student's concept maps, definitions, and essays to support the thesis that language-based prior knowledge can influence students' cognitive processes of mathematical concepts. A group of intermediate algebra students who displayed terms mainly from the spoken language on the first and the second concept…
College Students Attitude and Mathematics Achievement Using Web Based Homework
Leong, Kwan Eu; Alexander, Nathan
2014-01-01
The goal of this study was to understand how students' attitudes were connected to their mathematics learning and achievement. This investigation of students (n = 78) and their attitudes was specific to web-based homework in developmental mathematics courses in a two-year community college located in a large urban city in the United States. A…
Mathematical biology modules based on modern molecular biology and modern discrete mathematics.
Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander
2010-01-01
We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to introduce students to mathematical methods beyond the interface of biology with calculus. Based on ongoing research, and designed to use the project-based-learning approach, the modules highlight applications of modern discrete mathematics and algebraic statistics to pressing problems in molecular biology. For the majority of projects, calculus is not a required prerequisite and, due to the modest amount of mathematical background needed for some of the modules, the materials can be used for an early introduction to mathematical modeling. At the same time, most modules are connected with topics in linear and abstract algebra, algebraic geometry, and probability, and they can be used as meaningful applied introductions into the relevant advanced-level mathematics courses. Open-source software is used to facilitate the relevant computations. As a detailed example, we outline a module that focuses on Boolean models of the lac operon network.
Eringen, A Cemal
2013-01-01
Continuum Physics: Volume 1 - Mathematics is a collection of papers that discusses certain selected mathematical methods used in the study of continuum physics. Papers in this collection deal with developments in mathematics in continuum physics and its applications such as, group theory functional analysis, theory of invariants, and stochastic processes. Part I explains tensor analysis, including the geometry of subspaces and the geometry of Finsler. Part II discusses group theory, which also covers lattices, morphisms, and crystallographic groups. Part III reviews the theory of invariants th
Inquiry-Based Mathematics Curriculum Design for Young Children-Teaching Experiment and Reflection
Wu, Su-Chiao; Lin, Fou-Lai
2016-01-01
A group of teacher educators and practitioners in mathematics education and early childhood education generalized a set of inquiry-based mathematics models for Taiwanese young children of ages 3-6 and designed a series of inquiry-based mathematics curriculum tasks in cultivate the children's diverse mathematical concepts and mathematical power. In…
A New Activity-Based Cost (ABC) Mathematical Model
Institute of Scientific and Technical Information of China (English)
JIANG Shuo; SONG Lei
2003-01-01
Along with the product price competition growing intensely, it is apparently important for reasonably distributing and counting cost. But, in sharing indirect cost, traditional cost accounting unveils the limitations increasingly, especially in authenticity of cost information. And the accounting theory circles and industry circles begin seeking one kind of new accurate cost calculation method, and the activity-based cost (ABC) method emerges as the times require. In this paper, we will build its mathematical model by the basic principle of ABC, and will improve its mathematical model further. We will establish its comparison mathematical model and make the ABC method go a step further to its practical application.
Aspects and Views on Mathematical Optimization in Logistics in the Chemical Process Industry
Kallrath, Josef
2009-01-01
In large chemical companies, traffic logistics and supply chain logistics contain many decision problems which are suitable to be solved by mathematical optimization. The objectives are to exploit resources (traffic infrastructure such as roads and rail lines, production equipment) in a cost optimal way and to maximize profit. We present two cases: optimal sequences of rail cars in trains visiting various plants in a large company complex, and production and distributio...
Stein, Sherman K
2010-01-01
Anyone can appreciate the beauty, depth, and vitality of mathematics with the help of this highly readable text, specially developed from a college course designed to appeal to students in a variety of fields. Readers with little mathematical background are exposed to a broad range of subjects chosen from number theory, topology, set theory, geometry, algebra, and analysis. Starting with a survey of questions on weight, the text discusses the primes, the fundamental theorem of arithmetic, rationals and irrationals, tiling, tiling and electricity, probability, infinite sets, and many other topi
DEFF Research Database (Denmark)
Kiil, Søren
2011-01-01
A mathematical model, describing the curing behaviour of a two-component, solvent-based, thermoset coating, is used to conduct a parameter study. The model includes curing reactions, solvent intra-film diffusion and evaporation, film gelation, vitrification, and crosslinking. A case study with a ...
Computer-based controlon mathematical education of the future engineers
Directory of Open Access Journals (Sweden)
Катерина Володимирівна Власенко
2016-04-01
Full Text Available There was offered the computer-based management of the scientific-cognitive activity of the future engineers and organization of control on mathematical education using the attainments of the modern information technologies. There were analyzed the e-school-books elaborated by the higher mathematics teachers of the Donbass state academy of mechanical engineering and Donetsk national technical university. There was grounded an expediency of the use of aforesaid school-books during the lectures or independent students’ work and at the control on education of the future specialists of engineer branch that is considered as the category of management as the relatively independent final element of managerial cycle of educational process. There were offered methodological recommendations of the use of e-educational technologies at mathematical studies. There was elucidated how the introduction of educational materials from internet-resource with the access mode http://vmdbi.net.ua/ favors the computer-based control on education: oral questioning of students, written control works, tests and so on. There was proved that the use of offered means at the control on mathematical education gives the possibility to establish the reverse connection at studying mathematics and comprehensively examine the level of knowledge and skills of the studied discipline in students
Using Curriculum-Based Measurement to Monitor Kindergarteners' Mathematics Development
Seethaler, Pamela M.; Fuchs, Lynn S.
2011-01-01
The purpose of this study was to examine technical and instructional features of a kindergarten curriculum-based measurement (CBM) tool designed to track students' mathematics progress in terms of computational concepts, procedures, and counting strategies. Students in 10 kindergarten classrooms in three elementary schools completed alternate…
Discipline-Based Remediation: Bridging the Mathematics Gap
Wenner, Jennifer M.; Baer, Eric M.; Burn, Helen E.
2013-10-01
Geoscience relies on numbers, data, equations, graphical representations, and other quantitative skills; therefore, introductory geoscience courses need to accurately portray the science as quantitative [e.g., Wenner et al., 2009]. However, up to 57% of students arrive at college underprepared to perform mathematics at the level necessary to succeed in introductory courses [ACT, 2011]. Although some institutions have turned to prerequisites as a way to ensure appropriate preparation, these extra courses can place undue financial, temporal, and academic burdens on interested students, keeping them from enrolling in science courses that may interest them. As an alternative to mathematics prerequisites, geoscience faculty at the University of Wisconsin Oshkosh and Highline Community College in Des Moines, Wash., funded by the National Science Foundation, developed a model of successful integration of discipline-based mathematics remediation into an introductory geoscience course: The Math You Need, When You Need It (TMYN; http://serc.carleton.edu/mathyouneed/).
Indian Academy of Sciences (India)
Aldona Krupska
2015-06-01
In this paper the arduous attempt to find a mathematical solution for the nonlinear autocatalytic chemical processes with a time-varying and oscillating inflow of reactant to the reaction medium has been taken. Approximate analytical solution is proposed. Numerical solutions and analytical attempts to solve the non-linear differential equation indicates a phase shift between the oscillatory influx of intermediate reaction reagent to the medium of chemical reaction and the change of its concentration in this medium. Analytical solutions indicate that this shift may be associated with the reaction rate constants 1 and 2 and the relaxation time . The relationship between the phase shift and the oscillatory flow of reactant seems to be similar to that obtained in the case of linear chemical reactions, as described previously, however, the former is much more complex and different. In this paper, we would like to consider whether the effect of forced phase shift in the case of nonlinear and non-oscillatory chemical processes occurring particularly in the living systems have a practical application in laboratory.
Mathematical Modeling of Column-Base Connections under Monotonic Loading
Directory of Open Access Journals (Sweden)
Gholamreza Abdollahzadeh
2014-12-01
Full Text Available Some considerable damage to steel structures during the Hyogo-ken Nanbu Earthquake occurred. Among them, many exposed-type column bases failed in several consistent patterns, such as brittle base plate fracture, excessive bolt elongation, unexpected early bolt failure, and inferior construction work, etc. The lessons from these phenomena led to the need for improved understanding of column base behavior. Joint behavior must be modeled when analyzing semi-rigid frames, which is associated with a mathematical model of the moment–rotation curve. The most accurate model uses continuous nonlinear functions. This article presents three areas of steel joint research: (1 analysis methods of semi-rigid joints; (2 prediction methods for the mechanical behavior of joints; (3 mathematical representations of the moment–rotation curve. In the current study, a new exponential model to depict the moment–rotation relationship of column base connection is proposed. The proposed nonlinear model represents an approach to the prediction of M–θ curves, taking into account the possible failure modes and the deformation characteristics of the connection elements. The new model has three physical parameters, along with two curve-fitted factors. These physical parameters are generated from dimensional details of the connection, as well as the material properties. The M–θ curves obtained by the model are compared with published connection tests and 3D FEM research. The proposed mathematical model adequately comes close to characterizing M–θ behavior through the full range of loading/rotations. As a result, modeling of column base connections using the proposed mathematical model can give crucial beforehand information, and overcome the disadvantages of time consuming workmanship and cost of experimental studies.
Semantic Web Based Efficient Search Using Ontology and Mathematical Model
Directory of Open Access Journals (Sweden)
K.Palaniammal
2014-01-01
Full Text Available The semantic web is the forthcoming technology in the world of search engine. It becomes mainly focused towards the search which is more meaningful rather than the syntactic search prevailing now. This proposed work concerns about the semantic search with respect to the educational domain. In this paper, we propose semantic web based efficient search using ontology and mathematical model that takes into account the misleading, unmatched kind of service information, lack of relevant domain knowledge and the wrong service queries. To solve these issues in this framework is designed to make three major contributions, which are ontology knowledge base, Natural Language Processing (NLP techniques and search model. Ontology knowledge base is to store domain specific service ontologies and service description entity (SDE metadata. The search model is to retrieve SDE metadata as efficient for Education lenders, which include mathematical model. The Natural language processing techniques for spell-check and synonym based search. The results are retrieved and stored in an ontology, which in terms prevents the data redundancy. The results are more accurate to search, sensitive to spell check and synonymous context. This paper reduces the user’s time and complexity in finding for the correct results of his/her search text and our model provides more accurate results. A series of experiments are conducted in order to respectively evaluate the mechanism and the employed mathematical model.
REALIZATION OF MULTIPLEOPERAND ADDER-SUBTRACTOR BASED ON VEDIC MATHEMATICS
Directory of Open Access Journals (Sweden)
NEETA PANDEY
2014-07-01
Full Text Available This paper presents multiple-operand adder-subtractor based on Nikhilam Sutra of Vedic mathematics. The Sutra is adapted for binary operands. The hardware implementation uses carry save adders and a new 2’s exponent subtractor for faster operation and hardware reduction. The suitability of the theoretical proposition is demonstrated through exhaustive examples. The functionality of the circuit is verified through VHDL simulations. The synthesis results and comparisons with conventional methods are also included.
Wardono; Waluya, S. B.; Mariani, Scolastika; Candra D, S.
2016-02-01
This study aims to find out that there are differences in mathematical literacy ability in content Change and Relationship class VII Junior High School 19, Semarang by Problem Based Learning (PBL) model with an Indonesian Realistic Mathematics Education (called Pendidikan Matematika Realistik Indonesia or PMRI in Indonesia) approach assisted Elearning Edmodo, PBL with a PMRI approach, and expository; to know whether the group of students with learning PBL models with PMRI approach and assisted E-learning Edmodo can improve mathematics literacy; to know that the quality of learning PBL models with a PMRI approach assisted E-learning Edmodo has a good category; to describe the difficulties of students in working the problems of mathematical literacy ability oriented PISA. This research is a mixed methods study. The population was seventh grade students of Junior High School 19, Semarang Indonesia. Sample selection is done by random sampling so that the selected experimental class 1, class 2 and the control experiment. Data collected by the methods of documentation, tests and interviews. From the results of this study showed average mathematics literacy ability of students in the group PBL models with a PMRI approach assisted E-learning Edmodo better than average mathematics literacy ability of students in the group PBL models with a PMRI approach and better than average mathematics literacy ability of students in the expository models; Mathematics literacy ability in the class using the PBL model with a PMRI approach assisted E-learning Edmodo have increased and the improvement of mathematics literacy ability is higher than the improvement of mathematics literacy ability of class that uses the model of PBL learning with PMRI approach and is higher than the improvement of mathematics literacy ability of class that uses the expository models; The quality of learning using PBL models with a PMRI approach assisted E-learning Edmodo have very good category.
Chirskaia, Natalia; Novikov, Lev; Voronina, Ekaterina
2016-07-01
Atomic oxygen (AO) of the upper atmosphere is one of the most important space factors that can cause degradation of spacecraft surface. In our previous mathematical model the Monte Carlo method and the "large particles" approximation were used for simulating processes of polymer etching under the influence of AO [1]. The interaction of enlarged AO particles with the polymer was described in terms of probabilities of reactions such as etching of polymer and specular and diffuse scattering of the AO particles on polymer. The effects of atomic oxygen on protected polymers and microfiller containing composites were simulated. The simulation results were in quite good agreement with the results of laboratory experiments on magnetoplasmadynamic accelerator of the oxygen plasma of SINP MSU [2]. In this paper we present a new model that describes the reactions of AO interactions with polymeric materials in more detail. Reactions of formation and further emission of chemical compounds such as CO, CO _{2}, H _{2}O, etc. cause the modification of the chemical composition of the polymer and change the probabilities of its consequent interaction with the AO. The simulation results are compared with the results of previous simulation and with the results of laboratory experiments. The reasons for the differences between the results of natural experiments on spacecraft, laboratory experiments and simulations are discussed. N. Chirskaya, M. Samokhina, Computer modeling of polymer structures degradation under the atomic oxygen exposure, WDS'12 Proceedings of Contributed Papers: Part III - Physics, Matfyzpress Prague, 2012, pp. 30-35. E. Voronina, L. Novikov, V. Chernik, N. Chirskaya, K. Vernigorov, G. Bondarenko, and A. Gaidar, Mathematical and experimental simulation of impact of atomic oxygen of the earth's upper atmosphere on nanostructures and polymer composites, Inorganic Materials: Applied Research, 2012, vol. 3, no. 2, pp. 95-101.
Image Filtering Based on Mathematical Morphology and Visual Perception Principle
Institute of Scientific and Technical Information of China (English)
JINGXiaojun; YUNong; SHANGYong
2004-01-01
The operation of a morphological filter can be divided into two basic problems that include morphological operation and Structuring element (SE) selection. The rules for morphological operations are predefined, so the filter's properties depend merely on the selection of SE. How to design adaptively the optimal morphological filter so as to automatically and delicately complete the tasks of target detection and recognition, becomes one of the current research hotspots and subtle technical problems. Based on the filtering theory of the mathematical morphology, by introducing appropriate visual perception principle, this paper presents how to design the filtering architecture and its target detection model through the optimal parameter training. By this way it can provide good detection results and robust adaptability to image targets with clutter background. It is sure to provide a new approach to automatic target recognition with mathematical morphology theory.
Filler segmentation of SEM paper images based on mathematical morphology.
Ait Kbir, M; Benslimane, Rachid; Princi, Elisabetta; Vicini, Silvia; Pedemonte, Enrico
2007-07-01
Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO3 particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators.
Information system based on the mathematical model of the EPS
Kalimoldayev, Maksat N.; Abdildayeva, Assel A.; Mamyrbayev, Orken Zh.; Akhmetzhanov, Maksat
2016-11-01
This article discusses the structure of an information system, the mathematical and information models of electric power systems. Currently, the major application areas include system relaying data communication systems and automation, automated dispatching and technological management of electric power facilities, as well as computer-aided calculation of energy resources. Automatic control of excitation (ARV) synchronous machines is one of the most effective ways to ensure the stability of power systems. However, the variety of possible options and modes even in a single grid pose significant obstacles to the development of the best means of ensuring sustainability. Thus, the use of ARVs to ensure stability in some cases may not be sufficient. Therefore, there is a need to develop an information system based on a mathematical model.
Ottmar, Erin R.; Rimm-Kaufman, Sara E.; Larsen, Ross A.; Berry, Robert Q.
2015-01-01
This study investigates the effectiveness of the Responsive Classroom (RC) approach, a social and emotional learning intervention, on changing the relations between mathematics teacher and classroom inputs (mathematical knowledge for teaching [MKT] and standards-based mathematics teaching practices) and student mathematics achievement. Work was…
Directory of Open Access Journals (Sweden)
Fethi Bin Muhammad Belgacem
2014-10-01
Full Text Available In this paper, using the Extended Trial Equation (ETEM, we get new traveling wave solutions of the Generalized Benjamin, the Generalized Burger-Kdv Equations (GBE, GBKE. The obtained solutions not only constitute a novel analytical viewpoint in nonlinear complex phenomena, but they also form a new stand alone basis from which physical applications in this arena can be comprehended further, and moreover investigated. Furthermore, to concretely enrich this research production, we provide illustrative, Mathematica Release 7 based, 3D graphics of the gotten solutions, with well chosen, yet structure revealing parameters.
Nanotube-Based Chemical and Biomolecular Sensors
Institute of Scientific and Technical Information of China (English)
J.Koh; B.Kim; S.Hong; H.Lim; H.C.Choi
2008-01-01
We present a brief review about recent results regarding carbon nanotube (CNT)-based chemical and biomolecular sensors. For the fabrication of CNT-based sensors, devices containing CNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition (CVD) process or "surface programmed assembly" method. Then, the CNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive CNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.
Butkovich, Nancy J.
2015-01-01
Doctoral candidates may request short-term embargoes on the release of their dissertations in order to apply for patents. This study examines how often inventions described in dissertations in chemical engineering, chemistry, physics, and mathematics are converted into U.S. patent applications, as well as the relationship between dissertation…
Mathematical model for light scanning system based on circular laser
Institute of Scientific and Technical Information of China (English)
Peiquan Xu; Shun Yao; Fenggui Lu; Xinhua Tang; Wei Zhang
2005-01-01
A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built.This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams,escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in "spot" or "line" type laser trajectory. Three-dimensional (3D) model for welded seams could be recognized after depth recovery. The imaging error is investigated also.
Jitendra, Asha K.; Dupuis, Danielle N.; Zaslofsky, Anne F.
2014-01-01
This purpose of this study was to examine the reliability and validity of a curriculum-based measure of word problem solving (CBM-WPS) as an indicator of performance and progress in a sample of 136 third-grade students at risk for mathematics difficulties (MDs) instructed in a standards-based mathematics curriculum. Students completed the CBM-WPS…
Ningxia Becomes China's Largest Coal Chemical Base
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
@@ Northwest China's Ningxia Hui Autonomous Region plans to invest more than 100 billion yuan (US$12.9 billion) to build Asia's largest liquefied-coal base,according to the regional development and reform commission. The first group of projects, designed to produce methanol and other chemicals from coal, are under construction in the Ningdong Chemical Resource Base, which is located near coal deposits containing 80 percent of Ningxia's known coal reserves, said Hao Linhai, director of the regional commission.
A MATLAB-Aided Method for Teaching Calculus-Based Business Mathematics
Liang, Jiajuan; Pan, William S. Y.
2009-01-01
MATLAB is a powerful package for numerical computation. MATLAB contains a rich pool of mathematical functions and provides flexible plotting functions for illustrating mathematical solutions. The course of calculus-based business mathematics consists of two major topics: 1) derivative and its applications in business; and 2) integration and its…
Unraveling the Culture of the Mathematics Classroom: A Video-Based Study in Sixth Grade
Depaepe, Fien; De Corte, Erik; Verschaffel, Lieven
2007-01-01
Changing perspectives on mathematics teaching and learning resulted in a new generation of mathematics textbooks, stressing among others the importance of mathematical reasoning and problem-solving skills and their application to real-life situations. The article reports a study that investigates to what extent the reform-based ideas underlying…
Choudhury, Pabitra Pal; Jana, Siddhartha Sankar
2016-01-01
Comparison of amino acid sequence similarity is the fundamental concept behind the protein phylogenetic tree formation. By virtue of this method, we can explain the evolutionary relationships, but further explanations are not possible unless sequences are studied through the chemical nature of individual amino acids. Here we develop a new methodology to characterize the protein sequences on the basis of the chemical nature of the amino acids. We design various algorithms for studying the variation of chemical group transitions and various chemical group combinations as patterns in the protein sequences. The amino acid sequence of conventional myosin II head domain of 14 family members are taken to illustrate this new approach. We find two blocks of maximum length 6 aa as ‘FPKATD’ and ‘Y/FTNEKL’ without repeating the same chemical nature and one block of maximum length 20 aa with the repetition of chemical nature which are common among all 14 members. We also check commonality with another motor protein sub-family kinesin, KIF1A. Based on our analysis we find a common block of length 8 aa both in myosin II and KIF1A. This motif is located in the neck linker region which could be responsible for the generation of mechanical force, enabling us to find the unique blocks which remain chemically conserved across the family. We also validate our methodology with different protein families such as MYOI, Myosin light chain kinase (MLCK) and Rho-associated protein kinase (ROCK), Na+/K+-ATPase and Ca2+-ATPase. Altogether, our studies provide a new methodology for investigating the conserved amino acids’ pattern in different proteins. PMID:27930687
Directory of Open Access Journals (Sweden)
Marković Jelena Đ.
2009-01-01
Full Text Available Membrane process efficiency in the dairy industry is impaired by the formation of deposits during filtration processes. This work describes cleaning procedures for ceramic tubular membrane (50 nm fouled with whey proteins. Also, mathematical modelling was performed to obtain models which allow deeper insight into the mechanisms involved during cleaning procedures. The caustic solutions (0.2%w/w, 0.4%w/w and 1.0%w/w NaOH and the mixture of two commercial detergents (0.8%w/w P3-ultrasil 69+0.5% w/w P3-ultrasil 67 and 1.2% P3-ultrasil 69+0.75 P3-ultrasil 67 were used as chemical cleaning agents. The results showed that the best flux recovery was achieved with 0.4%w/w NaOH solution. After analyzing the experimental data, five parameter and six parameter kinetic models were suggested for alkali and detergent cleaning, respectively. The changes of total and specific resistances, as well as the change of the effective pore diameter and deposit thickness during cleaning are estimated by applying these models.
Looney, Craig W.
2009-10-01
Wolfram|Alpha (http://www.wolframalpha.com/), a free internet-based mathematical engine released earlier this year, represents an orders-of magnitude advance in mathematical power freely available - without money, passwords, or downloads - on the web. Wolfram|Alpha is based on Mathematica, so it can plot functions, take derivatives, solve systems of equations, perform symbolic and numerical integration, and more. These capabilities (especially plotting and integration) will be explored in the context of topics covered in upper level undergraduate physics courses.
PREFACE: Physics-Based Mathematical Models for Nanotechnology
Voon, Lok C. Lew Yan; Melnik, Roderick; Willatzen, Morten
2008-03-01
stain-resistant clothing, but with thousands more anticipated. The focus of this interdisciplinary workshop was on determining what kind of new theoretical and computational tools will be needed to advance the science and engineering of nanomaterials and nanostructures. Thanks to the stimulating environment of the BIRS, participants of the workshop had plenty of opportunity to exchange new ideas on one of the main topics of this workshop—physics-based mathematical models for the description of low-dimensional semiconductor nanostructures (LDSNs) that are becoming increasingly important in technological innovations. The main objective of the workshop was to bring together some of the world leading experts in the field from each of the key research communities working on different aspects of LDSNs in order to (a) summarize the state-of-the-art models and computational techniques for modeling LDSNs, (b) identify critical problems of major importance that require solution and prioritize them, (c) analyze feasibility of existing mathematical and computational methodologies for the solution of some such problems, and (d) use some of the workshop working sessions to explore promising approaches in addressing identified challenges. With the possibility of growing practically any shape and size of heterostructures, it becomes essential to understand the mathematical properties of quantum-confined structures including properties of bulk states, interface states, and surface states as a function of shape, size, and internal strain. This workshop put strong emphasis on discussions of the new mathematics needed in nanotechnology especially in relation to geometry and material-combination optimization of device properties such as electronic, optical, and magnetic properties. The problems that were addressed at this meeting are of immense importance in determining such quantum-mechanical properties and the group of invited participants covered very well all the relevant disciplines
Analysis of quantitative pore features based on mathematical morphology
Institute of Scientific and Technical Information of China (English)
QI Heng-nian; CHEN Feng-nong; WANG Hang-jun
2008-01-01
Wood identification is a basic technique of wood science and industry. Pore features are among the most important identification features for hardwoods. We have used a method based on an analysis of quantitative pore feature, which differs from traditional qualitative methods. We applies mathematical morphology methods such as dilation and erosion, open and close transformation of wood cross-sections, image repairing, noise filtering and edge detection to segment the pores from their background. Then the mean square errors (MSE) of pores were computed to describe the distribution of pores. Our experiment shows that it is easy to classift the pore features into three basic types, just as in traditional qualitative methods, but with the use of MSE of pores. This quantitative method improves wood identification considerably.
Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics
Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander
2010-01-01
We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to…
Computer-Based Mathematics Instructions for Engineering Students
Khan, Mustaq A.; Wall, Curtiss E.
1996-01-01
Almost every engineering course involves mathematics in one form or another. The analytical process of developing mathematical models is very important for engineering students. However, the computational process involved in the solution of some mathematical problems may be very tedious and time consuming. There is a significant amount of mathematical software such as Mathematica, Mathcad, and Maple designed to aid in the solution of these instructional problems. The use of these packages in classroom teaching can greatly enhance understanding, and save time. Integration of computer technology in mathematics classes, without de-emphasizing the traditional analytical aspects of teaching, has proven very successful and is becoming almost essential. Sample computer laboratory modules are developed for presentation in the classroom setting. This is accomplished through the use of overhead projectors linked to graphing calculators and computers. Model problems are carefully selected from different areas.
Material Encounters with Mathematics: The Case for Museum Based Cross-Curricular Integration
de Freitas, Elizabeth; Bentley, Sean J.
2012-01-01
This paper reports on research from a network of high school and museum partnerships designed to explore techniques for integrating mathematics and physics learning experiences during the first year of high school. The foundation of the curriculum is a problem-based, museum-based, and hands-on approach to mathematics and physics. In this paper, we…
Directory of Open Access Journals (Sweden)
Alexey M. Lipanov
1997-10-01
Full Text Available In this paper, the laws of the unstable wave processes accompanying the combustion abnormal mode in the large-sized solid propellant rocket motor {SPRM pyrotechnical ignition system {IS are investigated by numerical method. The IS contains the main {cylindrical channel (MC having uniform perforation over the lateral surface, The left MC boundary is blocked and the right boundary is uniformly perforated. The whole perforation is hermetically sealed from outside. The additional {cylindrical channel {AC {an initial impulse amplifier with uniform perforation over the lateral surface is installed into the MC cavity, coaxially to MC. The right AC boundary is blocked, and the time-varying high-temperature gas flow, containing incandescent 'particles is supplied from initiator, equipped with a fast burning compound, through AC left perforated boundary. To imitate the exploitation conditions, the IS is placed in cylindrical imitation chamber {imitative SPRM. In a number of cases, before the beginning of the IS operation, a situation can be realised when the pelletised solid propellant {PSP mass is non-uniformly distributed along the IS AC length, and the greater part of the AC lateral perforation is blocked by the PSP inserted in the IS MC. Under these conditions, the effect of abnormal strengthening of the pressure waves at the AC boundaries is possible. For describing the abnormal nonstationary physico-chemical processes, a mathematical model is developed. For the check-up of this complex model, the numerical calculation results have been compared with the results of the fire stand tests for the regular IS and the engine. The numerical analysis of the unstable wave process development in the AC has shown that the rise of the pressure with an ever increasing amplitude is realised at the moment, when a shock wave reflects alternately, on the left and on the right AC boundaries. The effect of the pressure waves' abnormal strengthening can result in the
Hodges, Thomas E.; Jong, Cindy
2014-01-01
The authors drew upon Remillard and Bryans' categorization of curriculum use in observating two middle-grade teachers' integration of Standards-based curriculum materials produced by the National Council of Teachers of Mathematics. Each teacher participated in a two-year professional development program focused on increasing content knowledge and…
Ross, E W; Taub, I A; Doona, C J; Feeherry, F E; Kustin, K
2005-03-15
Knowledge of the mathematical properties of the quasi-chemical model [Taub, Feeherry, Ross, Kustin, Doona, 2003. A quasi-chemical kinetics model for the growth and death of Staphylococcus aureus in intermediate moisture bread. J. Food Sci. 68 (8), 2530-2537], which is used to characterize and predict microbial growth-death kinetics in foods, is important for its applications in predictive microbiology. The model consists of a system of four ordinary differential equations (ODEs), which govern the temporal dependence of the bacterial life cycle (the lag, exponential growth, stationary, and death phases, respectively). The ODE system derives from a hypothetical four-step reaction scheme that postulates the activity of a critical intermediate as an antagonist to growth (perhaps through a quorum sensing biomechanism). The general behavior of the solutions to the ODEs is illustrated by several examples. In instances when explicit mathematical solutions to these ODEs are not obtainable, mathematical approximations are used to find solutions that are helpful in evaluating growth in the early stages and again near the end of the process. Useful solutions for the ODE system are also obtained in the case where the rate of antagonist formation is small. The examples and the approximate solutions provide guidance in the parameter estimation that must be done when fitting the model to data. The general behavior of the solutions is illustrated by examples, and the MATLAB programs with worked examples are included in the appendices for use by predictive microbiologists for data collected independently.
Mathematical design of prokaryotic clone-based microarrays
Directory of Open Access Journals (Sweden)
Quirijns Elisabeth J
2005-09-01
Full Text Available Abstract Background Clone-based microarrays, on which each spot represents a random genomic fragment, are a good alternative to open reading frame-based microarrays, especially for microorganisms for which the complete genome sequence is not available. Since the generation of a genomic DNA library is a random process, it is beforehand uncertain which genes are represented. Nevertheless, the genome coverage of such an array, which depends on different variables like the insert size and the number of clones in the library, can be predicted by mathematical approaches. When applying the classical formulas that determine the probability that a certain sequence is represented in a DNA library at the nucleotide level, massive amounts of clones would be necessary to obtain a proper coverage of the genome. Results This paper describes the development of two complementary equations for determining the genome coverage at the gene level. The first equation predicts the fraction of genes that is represented on the array in a detectable way and cover at least a set part (the minimal insert coverage of the genomic fragment by which these genes are represented. The higher this minimal insert coverage, the larger the chance that changes in expression of a specific gene can be detected and attributed to that gene. The second equation predicts the fraction of genes that is represented in spots on the array that only represent genes from a single transcription unit, which information can be interpreted in a quantitative way. Conclusion Validation of these equations shows that they form reliable tools supporting optimal design of prokaryotic clone-based microarrays.
Reactive chemical transport in ground-water hydrology: Challenges to mathematical modeling
Energy Technology Data Exchange (ETDEWEB)
Narasimhan, T.N.; Apps, J.A.
1990-07-01
For a long time, earth scientists have qualitatively recognized that mineral assemblages in soils and rocks conform to established principles of chemistry. In the early 1960's geochemists began systematizing this knowledge by developing quantitative thermodynamic models based on equilibrium considerations. These models have since been coupled with advective-dispersive-diffusive transport models, already developed by ground-water hydrologists. Spurred by a need for handling difficult environmental issues related to ground-water contamination, these models are being improved, refined and applied to realistic problems of interest. There is little doubt that these models will play an important role in solving important problems of engineering as well as science over the coming years. Even as these models are being used practically, there is scope for their improvement and many challenges lie ahead. In addition to improving the conceptual basis of the governing equations, much remains to be done to incorporate kinetic processes and biological mediation into extant chemical equilibrium models. Much also remains to be learned about the limits to which model predictability can be reasonably taken. The purpose of this paper is to broadly assess the current status of knowledge in modeling reactive chemical transport and to identify the challenges that lie ahead.
Directory of Open Access Journals (Sweden)
Edwin Musdi
2016-02-01
Full Text Available This research aims to develop a mathematics instructional model based realistic mathematics education (RME to promote students' problem-solving abilities. The design research used Plomp models, which consists of preliminary phase, development or proto-typing phase and assessment phase. At this study, only the first two phases conducted. The first phase, a preliminary investigation, carried out with a literature study to examine the theory-based instructional learning RME model, characteristics of learners, learning management descriptions by junior high school mathematics teacher and relevant research. The development phase is done by developing a draft model (an early prototype model that consists of the syntax, the social system, the principle of reaction, support systems, and the impact and effects of instructional support. Early prototype model contain a draft model, lesson plans, worksheets, and assessments. Tesssmer formative evaluation model used to revise the model. In this study only phase of one to one evaluation conducted. In the ppreliminary phase has produced a theory-based learning RME model, a description of the characteristics of learners in grade VIII Junior High School Padang and the description of teacher teaching in the classroom. The result showed that most students were still not be able to solve the non-routine problem. Teachers did not optimally facilitate students to develop problem-solving skills of students. It was recommended that the model can be applied in the classroom.
A framework for designing a research-based "mathematics counsellor" teacher programme
DEFF Research Database (Denmark)
Niss, Mogens Allan; Thomas Jankvist, Uffe
2015-01-01
This article addresses one way in which decades of mathematics education research results can inform practice, by offering a framework for designing and implementing an in-service teacher education programme for upper secondary mathematics teachers in Denmark. The programme aims to educate a “task...... force” of so-called “maths counsellors”, i.e., mathematics teachers whose goal it is to help identify students with genuine learning difficulties in mathematics, investigate the nature of these difficulties, and carry out research-based interventions to assist the students in overcoming them. We present...
Campbell, Stephen R.
2003-05-01
A challenging task in educational research today is to understand the implications of recent developments in computer-based learning environments. On the other hand, questions regarding learning and mathematical cognition have long been a central focus of research in mathematics education. Adding technology compounds an already complex problematic. Fortunately, computer-based technology also provides researchers with new ways of studying cognition and instruction. This paper introduces a new method for dynamically tracking learners' experiences in computer-based learning environments. Dynamic tracking is illustrated in both a classroom and a clinical setting by drawing on two studies with elementary preservice teachers working in computer-based mathematics learning environments.
Directory of Open Access Journals (Sweden)
Tudor Barbu
2014-06-01
Full Text Available A nonlinear diffusion based image denoising technique is introduced in this paper. The proposed PDE denoising and restoration scheme is based on a novel diffusivity function that uses an automatically detected conductance parameter. A robust mathematical treatment is also provided for our anisotropic diffusion model. We demonstrate that edge-stopping function model is properly chosen, explaining the mathematical reasons behind it. Also, we perform a rigorous mathematical investigation on of the existence and uniqueness of the solution of our nonlinear diffusion equation. This PDE-based noise removal approach outperforms most diffusion-based methods, producing considerably better smoothing results and providing a much better edge preservation.
Amineborane Based Chemical Hydrogen Storage - Final Report
Energy Technology Data Exchange (ETDEWEB)
Sneddon, Larry G.
2011-04-21
The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH3BH3 (AB), 19.6-wt% H2, and ammonia triborane NH3B3H7 (AT), 17.7-wt% H2, were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H2-release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H2-release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H2-release, the tunability of both their H2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic-liquid based systems attractive candidates for chemical hydrogen storage applications. These studies also
Marshall, Neil; Buteau, Chantal
2014-01-01
As part of their undergraduate mathematics curriculum, students at Brock University learn to create and use computer-based tools with dynamic, visual interfaces, called Exploratory Objects, developed for the purpose of conducting pure or applied mathematical investigations. A student's Development Process Model of creating and using an Exploratory…
Agyei, Douglas; Voogt, J.M.
2016-01-01
In this study, 12 pre-service mathematics teachers worked in teams to develop their knowledge and skills in using teacher-led spreadsheet demonstrations to help students explore mathematics concepts, stimulate discussions and perform authentic tasks through activity-based lessons. Pre-service teache
Huang, Tzu-Hua; Liu, Yuan-Chen; Chang, Hsiu-Chen
2012-01-01
This study developed a computer-assisted mathematical problem-solving system in the form of a network instruction website to help low-achieving second- and third-graders in mathematics with word-based addition and subtraction questions in Taiwan. According to Polya's problem-solving model, the system is designed to guide these low-achievers…
An Excel-Aided Method for Teaching Calculus-Based Business Mathematics
Liang, Jiajuan; Martin, Linda
2008-01-01
Calculus-based business mathematics is a required quantitative course for undergraduate business students in most AACSB accredited schools or colleges of business. Many business students, however, have relatively weak mathematical background or even display math-phobia when presented with calculus problems. Because of the popularity of Excel, its…
Evaluation of a Web Based Mathematics Teaching Material on the Subject of Functions
Baki, A.; Guveli, E.
2008-01-01
The aim of the study is to develop a web-based mathematics teaching (WBMT) material and to evaluate the effectiveness of the WBMT material for 9th grade students learning the concept of mathematical function. Firstly, a WBMT material was designed and piloted. As a result of this pilot study the site was revised as a final form. The study was…
Agyei, Douglas D.; Voogt, Joke M.
2016-01-01
In this study, 12 pre-service mathematics teachers worked in teams to develop their knowledge and skills in using teacher-led spreadsheet demonstrations to help students explore mathematics concepts, stimulate discussions and perform authentic tasks through activity-based lessons. Pre-service teachers' lesson plans, their instruction of the…
Carbon-Nanotube-Based Chemical Gas Sensor
Kaul, Arunpama B.
2010-01-01
Conventional thermal conductivity gauges (e.g. Pirani gauges) lend themselves to applications such as leak detectors, or in gas chromatographs for identifying various gas species. However, these conventional gauges are physically large, operate at high power, and have a slow response time. A single-walled carbon-nanotube (SWNT)-based chemical sensing gauge relies on differences in thermal conductance of the respective gases surrounding the CNT as it is voltage-biased, as a means for chemical identification. Such a sensor provides benefits of significantly reduced size and compactness, fast response time, low-power operation, and inexpensive manufacturing since it can be batch-fabricated using Si integrated-circuit (IC) process technology.
3-D Storm Automatic Identification Based on Mathematical Morphology
Institute of Scientific and Technical Information of China (English)
HAN Lei; ZHENG Yongguang; WANG Hongqing; LIN Yinjing
2009-01-01
The strom identification, tracking, and forecasting method is one of the important nowcasting techniques. Accurate storm identification is a prerequisite for successful storm tracking and forecasting. Storm identi-fication faces two difficulties: one is false merger and the other is failure to isolate adjacent storms within a cluster of storms. The TITAN (Thunderstorm Identification, Tracking, Analysis, and Nowcasting) algo-rithm is apt to identify adjacent storm cells as one storm because it uses a single refiectivity threshold. The SCIT (Storm Cell Identification and Tracking) algorithm uses seven reflectivity thresholds and therefore is capable of isolating adjacent storm cells, but it discards the results identified by the lower threshold, leading to the loss of the internal structure information of storms. Both TITAN and SCIT have the problem of failing to satisfactorily identify false merger. To overcome these shortcomings, this paper proposes a novel approach based on mathematical morphology. The approach first applies the single threshold identification followed by implementing an erosion process to mitigate the false merger problem. During multi-threshold identification stages, dilation operation is performed against the storm cells which are just obtained by the higher threshold identification, until the storm edges touch each other or touch the edges of the previous storms identified by the lower threshold. The results of experiment show that by combining the strengths of the dilation and erosion operations, this approach is able to mitigate the false merger problem as well as maintain the internal structure of sub-storms when isolating storms within a cluster of storms.
Study on Teaching Strategies in Mathematics Education based on CAI
Directory of Open Access Journals (Sweden)
Wei Yan Feng
2016-01-01
Full Text Available With the development of information technology and the popularization of internet, mobile phone, new media represented is gradually influencing and changing people’s study and life, become the centre and social consensus of cultural information, according to the China Internet Network Information centre, the youth is the main use of CAI(Computer Assisted Instruction, which is the most active group of customers, fully understand the impact of the new media environment for students, higher mathematics education of college students in CAI. In this paper, the CAI is proposed for mathematics education of college students.
Umansky, A. A.; Golovatenko, A. V.; Kadykov, V. N.; Dumova, L. V.
2016-09-01
Using the device of the complex “Gleeble System 3800” the physical experimental studies of deformation resistance of chrome rail steel at different thermo-mechanical deformation parameters were carried out. On the basis of mathematical processing of experimental data the statistical model of dependence of the rail steel deformation resistance on the simultaneous influence of deformation degree, rate and temperature, as well as the steel chemical composition, was developed. The nature of influence of deformation parameters and the content of chemical elements in steel on its resistance to plastic deformation is scientifically substantiated. Verification of the adequacy of the proposed model by the comparative analysis of the calculated and actual rolling forces during passes in the universal rail-and-structural steel mill JSC “EVRAZ Consolidated West Siberian Metallurgical Plant” (“EVRAZ ZSMK”) showed the possibility of its use for development and improvement of new modes of rails rolling.
Waveguide-based optical chemical sensor
Grace, Karen M.; Swanson, Basil I.; Honkanen, Seppo
2007-03-13
The invention provides an apparatus and method for highly selective and sensitive chemical sensing. Two modes of laser light are transmitted through a waveguide, refracted by a thin film host reagent coating on the waveguide, and analyzed in a phase sensitive detector for changes in effective refractive index. Sensor specificity is based on the particular species selective thin films of host reagents which are attached to the surface of the planar optical waveguide. The thin film of host reagents refracts laser light at different refractive indices according to what species are forming inclusion complexes with the host reagents.
Teachers' Activities in Technology-Based Mathematics Lessons
Monaghan, John
2004-01-01
This paper focuses on high school mathematics teachers and what they do when they use digital technology in their lessons. It is essentially a discursive paper but it uses data from a project on teachers using technology to illustrate points. The main aim of the paper is to present an holistic account of factors influencing teachers' practice. A…
Mathematical foundation of the optimization-based fluid animation method
DEFF Research Database (Denmark)
Erleben, Kenny; Misztal, Marek Krzysztof; Bærentzen, Jakob Andreas
2011-01-01
We present the mathematical foundation of a fluid animation method for unstructured meshes. Key contributions not previously treated are the extension to include diffusion forces and higher order terms of non-linear force approximations. In our discretization we apply a fractional step method...
Budak, Ayfer
2015-01-01
The purpose of this research is to examine the impact of a Standards-based elementary mathematics curriculum on third grade students' mathematics performance. A total of 707 students participated in this study. Of this total, 368 students were from eight schools located within the same school district in a racially and ethnically diverse large…
Hsu, Chun-Wei; Goh, Joshua O. S.
2016-01-01
When comparing between the values of different choices, human beings can rely on either more cognitive processes, such as using mathematical computation, or more affective processes, such as using emotion. However, the neural correlates of how these two types of processes operate during value-based decision-making remain unclear. In this study, we investigated the extent to which neural regions engaged during value-based decision-making overlap with those engaged during mathematical and emoti...
Mathematical Practices and Arts Integration in an Activity-Based Projective Geometry Course
Ernest, Jessica Brooke
It is a general assumption that the mathematical activity of students in school should, at least to some degree, parallel the practices of professional mathematicians (Brown, Collins, Duguid, 1989; Moschkovich, 2013). This assumption is reflected in the Common Core State Standards (CCSSI, 2010) and National Council of Teachers of Mathematics (NCTM, 2000) standards documents. However, the practices included in these standards documents, while developed to reflect the practices of professional mathematicians, may be idealized versions of what mathematicians actually do (Moschkovich, 2013). This might lead us to question then: "What is it that mathematicians do, and what practices are not being represented in the standards documents?" In general, the creative work of mathematicians is absent from the standards and, in turn, from school mathematics curricula, much to the dismay of some mathematicians and researchers (Lockhart, 2009; Rogers, 1999). As a result, creativity is not typically being fostered in mathematics students. As a response to this lack of focus on fostering creativity (in each of the science, technology, engineering, and mathematics disciplines--the STEM disciplines), a movement to integrate the arts emerged. This movement, called the STEAM movement--introducing the letter A into the acronym STEM to signify incorporating the arts--has been gaining momentum, yet limited research has been carried out on the efficacy of integrating the arts into mathematics courses. My experiences as the co-instructor for an activity-based course focused on projective geometry led me to consider the course as a setting for investigating both mathematical practices and arts integration. In this work, I explored the mathematical practices in which students engaged while working to develop an understanding of projective geometry through group activities. Furthermore, I explored the way in which students' learning experiences were enriched through artistic engagement in the
Mathematical Modeling of Carcinogenesis Based on Chromosome Aberration Data
Institute of Scientific and Technical Information of China (English)
Xiao-bo Li
2009-01-01
Objective: The progression of human cancer is characterized by the accumulation of genetic instability. An increasing number of experimental genetic molecular techniques have been used to detect chromosome aberrations. Previous studies on chromosome abnormalities often focused on identifying the frequent loci of chromosome alterations, but rarely addressed the issue of interrelationship of chromosomal abnormalities. In the last few years, several mathematical models have been employed to construct models of carcinogenesis, in an attempt to identify the time order and cause-and-effect relationship of chromosome aberrations. The principles and applications of these models are reviewed and compared in this paper. Mathematical modeling of carcinogenesis can contribute to our understanding of the molecular genetics of tumor development, and identification of cancer related genes, thus leading to improved clinical practice of cancer.
Mathematical model of delay lines based on magnetostatic waves
Directory of Open Access Journals (Sweden)
E. V. Kudinov
2010-12-01
Full Text Available On the example of the delay line have demonstrated the possibility of applying the principle of decomposition to construct mathematical models of microwave devices using magnetostatic waves (MSW in a magnetized epitaxial ferrite films, which allows for a unified methodological basis and the lowest cost to the experimental optimization design of MSW devices for various applications
Mathematics achievement based on gender among eight grade school students in Jordan
Rabab'h, Belal Sadiq Hamed; Veloo, Arsaythamby; Perumal, Selvan
2015-05-01
The purpose of this study is to identify the differences in gender base on numbers, algebra, geometry and mathematics achievement among Jordanian 8th grade school students. The respondent of this study were 337 students from eight public secondary schools in Alkoura district and selected by using stratified random sampling. The study comprised of 179 (53%) males and 158 (47%) females students. The mathematics test comprises of 30 items which has eight items for numbers, 14 items for algebra and eight items for geometry. Finding from independent sample t-test shows that female student score higher than male students in numbers, algebra, mathematics achievement and spatial visualization. There is no significant difference in geometry base for gender. This study also indicates that numbers, algebra and mathematics achievement favorable to female and bias to male students. The main recommendations from this study are for teachers and other educational professionals to focus on the numbers and algebra for male students to improve the learning of mathematics, and feeding program through benefiting from tutorial classes to avoid of weakness in different aspects of mathematics achievement. Gender differences in mathematics in secondary school students in Jordan continue to exist and these differences may influence future educational and occupational pathways.
Kubo, Izumi; Honda, Tatsuhiro; Yokota, Hisashi
In the academic year 2004 Faculty of Environmental Studies in Hiroshima Institute of Technology stopped coordinating the mathematical classes by the placement tests, because a number of students found themselves mismatched to assigned classes. This was due to the diversifying types of entrance exams. Instead the mathematics classes are now coordinated by the students‧ learning backgrounds. This paper presents the method of mathematics education based on class coordination by learners‧ backgrounds and the annotation on the time-history of the students‧ achievements for four years from the academic year 2004 to show the validity of this novel method of education for diversified students.
van der Schaft, Arjan; Jayawardhana, Bayu
2011-01-01
Motivated by recent progress on the interplay between graph theory, dynamics, and systems theory, we revisit the analysis of chemical reaction networks described by mass action kinetics. For reaction networks possessing a thermodynamic equilibrium we derive a compact formulation exhibiting at the same time the structure of the complex graph and the stoichiometry of the network, and which admits a direct thermodynamical interpretation. This formulation allows us to easily characterize the set of equilibria and their stability properties. Furthermore, we develop a framework for interconnection of chemical reaction networks. Finally we discuss how the established framework leads to a new approach for model reduction.
Analytical derivation: An epistemic game for solving mathematically based physics problems
Bajracharya, Rabindra R.; Thompson, John R.
2016-06-01
Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the analytical derivation game. This game involves deriving an equation through symbolic manipulations and routine mathematical operations, usually without any physical interpretation of the processes. This game often creates cognitive obstacles in students, preventing them from using alternative resources or better approaches during problem solving. We conducted hour-long, semi-structured, individual interviews with fourteen introductory physics students. Students were asked to solve four "pseudophysics" problems containing algebraic and graphical representations. The problems required the application of the fundamental theorem of calculus (FTC), which is one of the most frequently used mathematical concepts in physics problem solving. We show that the analytical derivation game is necessary, but not sufficient, to solve mathematically based physics problems, specifically those involving graphical representations.
Bio-based chemicals - green, but also sustainable?
DEFF Research Database (Denmark)
Ögmundarson, Ólafur; Herrgard, Markus; Förster, Jochen;
For almost two decades, the chemical industry has put great effort into developing bio-chemicals,among others to fight global warming caused by greenhouse gas emissions, one of the biggest threats that are faced by our society today. To facilitate a growing and versatile bio-based chemical...... production, the US Department of Energy proposed in 2004 a list of 12 building block chemicals which can either be converged through biological or chemical conversions. Moving toward more bio-based chemicals, the chemical industry does not only claim to reduce climate change impacts, but also...... that they are increasing overall sustainability in chemical production. Whether such claims are justifiable is unclear. When sustainability of bio-based polymer production is assessed, various environmental trade-offs occur that need to be considered. It is not enough to claim that a bio-chemical is sustainable...
DiffGame: Game-based mathematics learning for physics
Pedersen, Mads Kock; Dohn, Niels Bonderup; Lieberoth, Andreas; Sherson, Jacob
2016-01-01
Differentiation is a mathematical skill applied throughout science in order to describe the change of a function with respect to a dependent variable. Thus, an intuitive understanding of differentiation is necessary to work with the mathematical frameworks used to describe physical systems in the higher levels of education. In order to obtain this intuition repeated practice is required. In this paper we present the development of DiffGame, which consists of a series of exercises that introduce the basic principles of differentiation for high-school students through game-like elements. DiffGame have been tested with 117 first-year students from a single Danish high school, who did not have any prior training in differentiation. The students' learning was assessed by the data obtained directly from DiffGame. The test demonstrated the efficacy of DiffGame, since students at all levels demonstrate a learning gain. In contrast to previous studies demonstrating most learning in the lower tier of students, we find ...
Quantitative Study on Polymer Flocculation Mechanism Based on Mathematical Morphology
Institute of Scientific and Technical Information of China (English)
GUO Ling-xiang; WANG Chen-yi
2006-01-01
Until now, understanding of polymer flocculation has remained restricted within the qualitative explanations of the bridge unite theory and the electricity neutralization theory, because people not only lacked the systemic knowledge of the polymer flocculation mechanism, the flocculation dynamic process study and the flocculation effect estimate, but also could not penetrate within the flocculation process microscopic field to obtain the structural character parameters such as floccule structure, the frame bridge models and so on. In this paper, not only coal slurry flocculation images were photographed by using the transmission electron microscope, but also the basic theory of the mathematical morphology was applied to the coal slurry flocculation image processing. The steps and methods of the mathematical morphology were expounded in detail. The micro-structural parameters such as the flocculate size and the bridge length were obtained, which combined the microscopic flocculation grain configuration observations with the macroscopic flocculation effect, so as to get the maximum amount of veracious information to describe and explain the whole flocculation course by rule and line. On this basis, not only the flocculation models of polymers in the coal slurry are suggested, but the quantitative study on flocculation mechanism has been achieved.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.
Philosophy of Mathematical Chemistry: A Personal Perspective
Directory of Open Access Journals (Sweden)
Subhash C. Basak
2013-07-01
Full Text Available This article discusses the nature of mathematical chemistry, discrete mathematical chemistry in particular. Molecules and macromolecules can be represented by model objects using methods of discrete mathematics, e.g., graphs and matrices. Mathematical formalisms are further applied on the model objects to distill various quantitative characteristics. The end product of such an exercise can be a better understanding of chemistry, the development of quantitative scales for qualitative notions of chemistry, or an illumination of the structural basis of chemical and biological properties. The aforementioned aspects of mathematical chemistry are discussed based on my own practitioner’s perspective.
Mathematics Base and Logicism%数学基础中的逻辑主义
Institute of Scientific and Technical Information of China (English)
胡光远
2012-01-01
康托尔创立集合论，推进了数学家对于“无穷”的认识，但是却引出了被称为集合论悖论的第三次数学危机，这次危机导致了人们对于数学基础的深入研究。逻辑主义学派不仅致力解决集合论悖论．还决心将数学的基础建立在逻辑之上。该学派的工作虽然极大地促进了数学基础的研究和数理逻辑的发展，但是，将数学建立在逻辑上的目的却没有取得最终的成功。%Cantor founding set theory not only advanced mathematics on ＂infinitude＂ , but led to the known paradox of set theory and the third mathematical crisis. The crisis drove people to research the mathematical basis thoroughly. Logicist want to solve the paradox of set theory and base mathematics on logic. Logicist＇ s work greatly promoted the research of the mathematical basis and the development of mathematical logic. However, they can＇ t finish the task of building mathematics on the logic.
Evaluating the Use of Problem-Based Video Podcasts to Teach Mathematics in Higher Education
Kay, Robin; Kletskin, Ilona
2012-01-01
Problem-based video podcasts provide short, web-based, audio-visual explanations of how to solve specific procedural problems in subject areas such as mathematics or science. A series of 59 problem-based video podcasts covering five key areas (operations with functions, solving equations, linear functions, exponential and logarithmic functions,…
Opportunity-to-Learn Context-Based Tasks Provided by Mathematics Textbooks
Wijaya, Ariyadi; van den Heuvel-Panhuizen, Marja; Doorman, Michiel
2015-01-01
Based on the findings of an error analysis revealing that Indonesian ninth- and tenth-graders had difficulties in solving context-based tasks, we investigated the opportunity-to-learn offered by Indonesian textbooks for solving context-based mathematics tasks and the relation of this opportunity-to-learn to students' difficulties in solving these…
Opportunity-to-learn context-based tasks provided by mathematics textbooks
Wijaya, Ariyadi; Van den Heuvel-Panhuizen, M.; Doorman, Michiel
2015-01-01
Based on the findings of an error analysis revealing that Indonesian ninth- and tenth-graders had difficulties in solving context-based tasks, we investigated the opportunity-to-learn offered by Indonesian textbooks for solving context-based mathematics tasks and the relation of this opportunity-to-
Directory of Open Access Journals (Sweden)
Johann Engelbrecht
2009-09-01
Full Text Available Following the political changes of 1994 in South Africa, the decision was taken to replace the traditional skills-based education system at primary and secondary school level (Grades 1 - 12 with an outcomes-based education system (OBE. The OBE approach, referred to as Curriculum 2005, was introduced into schools in 1998. The implementation of the OBE system did not occur without problems, giving rise to revised initiatives and a fair amount of criticism. The 2009 intake of students at universities is the ﬁrst group of students that had been subjected to the OBE approach for their entire school career. This is also the ﬁrst group of students for whom some form of mathematics was compulsory up to Grade 12 level in the form of mathematics or mathematical literacy. These students were characterised by the fact that their mathematics marks for Grade 12 were exceptionally high and that many more students qualiﬁed for university entrance. This article reports on the impact of this new education system on the mathematics prepared-ness of students entering university. The study involves an empirical analysis of the students in the ﬁrst-year mathematics course for engineering students at the University of Pretoria as well as an analysis of a questionnaire completed by experienced lecturers at this university. The question addressed in this article is how the 2009 intake of students cope with mathematics at university level with regard to Performance General attributes Mathematical attributes Content-related attributesResults indicate a decrease in mathematics performance of these students at university level and that the inﬂated matric marks result in unjustiﬁed expectations. However, it is not unusual for marks to decrease from school to university and there is still too little evidence for serious concern. The study also indicates that these students seem to be better equipped with regard to personal attributes such as self-conﬁdence and
Ku, Oskar; Chen, Sherry Y.; Wu, Denise H.; Lao, Andrew C. C.; Chan, Tak-Wai
2014-01-01
Many students possess low confidence toward learning mathematics, which, in turn, may lead them to give up pursuing more mathematics knowledge. Recently, game-based learning (GBL) is regarded as a potential means in improving students' confidence. Thus, this study tried to promote students' confidence toward mathematics by using GBL. In…
Ku, Oskar; Chen, Sherry Y.; Wu, Denise H.; Lao, Andrew C. C.; Chan, Tak-Wai
2014-01-01
Many students possess low confidence toward learning mathematics, which, in turn, may lead them to give up pursuing more mathematics knowledge. Recently, game-based learning (GBL) is regarded as a potential means in improving students' confidence. Thus, this study tried to promote students' confidence toward mathematics by using GBL. In addition,…
Dong, Lianchun; Seah, Wee Tiong; Clarke, David
2015-01-01
This study examines a teacher's questioning strategies in mathematics classrooms in China when implementing reform-based mathematics curriculum. It explores teacher's strategies to deal with the tensions involved in the creation of opportunities for students to express and communicate mathematics ideas while ensuring the productivity of…
Directory of Open Access Journals (Sweden)
Mikhailova N. V.
2015-01-01
Full Text Available In the article, philosophical and methodological analysis of the program of Hilbert's formalism as a really working direction for consideration of the bases of modern mathematics is presented. For the professional mathematicians methodological advantages of the program of formalism advanced by David Hilbert, consist primarily in the fact that the highest possible level of theoretical rigor of modern mathematical theories was practically represented there. To resolve the fundamental difficulties of the problem of bases of mathematics, according to Hilbert, the theory of mathematical proof is needed, but contrary to popular belief rigorous formalization of the proof is not a synonym of reliability and rigor of mathematical reasoning from the point of view of the philosophy of the foundations of mathematics. In fact, the consistency of the theories is "more important" than their logical consistency because not every statement, which does not contradict to the reasonable ones, can be attributed to a true statement. However, for working mathematicians, Hilbert is logical and consistent and the axiomatic method and formalism are an essential part of their rules of thinking.
Grimaldi, Ralph P.
This material was developed to provide an application of matrix mathematics in chemistry, and to show the concepts of linear independence and dependence in vector spaces of dimensions greater than three in a concrete setting. The techniques presented are not intended to be considered as replacements for such chemical methods as oxidation-reduction…
Gultepe, Nejla; Yalcin Celik, Ayse; Kilic, Ziya
2013-01-01
The purpose of the study was to examine the effects of students' conceptual understanding of chemical concepts and mathematical processing skills on algorithmic problem-solving skills. The sample (N = 554) included grades 9, 10, and 11 students in Turkey. Data were collected using the instrument "MPC Test" and with interviews. The…
Scaffolding norms of argumentation-based inquiry in a primary mathematics classroom
Makar, Katie; Bakker, Arthur; Ben-Zvi, Dani
2015-01-01
Developing argumentation-based inquiry practices requires teachers and students to be explicit about classroom norms that support these practices. In this study, we asked: How can a teacher scaffold the development of argumentation-based inquiry norms and practices in a mathematics classroom? A prim
Students' Mathematics Word Problem-Solving Achievement in a Computer-Based Story
Gunbas, N.
2015-01-01
The purpose of this study was to investigate the effect of a computer-based story, which was designed in anchored instruction framework, on sixth-grade students' mathematics word problem-solving achievement. Problems were embedded in a story presented on a computer as computer story, and then compared with the paper-based version of the same story…
Discourses about School-Based Mathematics Teacher Education in Finland and Sweden
Ryve, Andreas; Hemmi, Kirsti; Borjesson, Mats
2013-01-01
In this cross-case study we focus on school-based teacher education in Sweden and Finland. Through the use of focus-group interviews with mathematics teacher educators in Finland and Sweden, the study shows that there are substantial differences in how school-based teacher education is introduced and portrayed in the discourse about teacher…
Using E-Exercise Bases in Mathematics: Case Studies at University
Cazes, Claire; Gueudet, Ghislaine; Hersant, Magali; Vandebrouck, Fabrice
2006-01-01
E-Exercise Bases (EEB) are now used in the teaching of mathematics, especially at university. We discuss here the consequences of their use on the students' activity during computer lab sessions. Results stem from observations of several teaching designs organised in different French universities with three e-exercise bases. The analysis focuses…
Effects of Computer-Based Programs on Mathematical Achievement Scores for Fourth-Grade Students
Ravenel, Jessica; Lambeth, Dawn T.; Spires, Bob
2014-01-01
The purpose of the research study was to identify the effects of computer-based programs on mathematical achievement, perceptions, and engagement of fourth-grade students. The 31 student participants were divided into two intervention groups, as a hands-on group and a computer-based group. Student achievement was measured by comparing the pretest…
Mathematical Based Calculation of Drug Penetration Depth in Solid Tumors
Directory of Open Access Journals (Sweden)
Hamidreza Namazi
2016-01-01
Full Text Available Cancer is a class of diseases characterized by out-of-control cells’ growth which affect cells and make them damaged. Many treatment options for cancer exist. Chemotherapy as an important treatment option is the use of drugs to treat cancer. The anticancer drug travels to the tumor and then diffuses in it through capillaries. The diffusion of drugs in the solid tumor is limited by penetration depth which is different in case of different drugs and cancers. The computation of this depth is important as it helps physicians to investigate about treatment of infected tissue. Although many efforts have been made on studying and measuring drug penetration depth, less works have been done on computing this length from a mathematical point of view. In this paper, first we propose phase lagging model for diffusion of drug in the tumor. Then, using this model on one side and considering the classic diffusion on the other side, we compute the drug penetration depth in the solid tumor. This computed value of drug penetration depth is corroborated by comparison with the values measured by experiments.
Directory of Open Access Journals (Sweden)
Reviandari Widyatiningtyas
2015-07-01
Full Text Available The study was report the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students’ prior mathematical ability to student’s mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from excellent and moderate school level. The research instruments a set of mathematical critical thinking ability test, and the data were analyzed by using two ways ANOVA and t-test. The research found that the problem based learning approach has significant impact to the ability of students’ mathematics critical thinking in terms of school level and students’ prior mathematical abilities. Furthermore. This research also found that there is no interaction between learning approach and school level, and learning approach and students’ prior mathematics ability to students’ mathematics critical thinking ability.
Mathematical Modelling of a Hybrid Micro-Cogeneration Group Based on a Four Stroke Diesel Engine
Directory of Open Access Journals (Sweden)
Apostol Valentin
2014-06-01
Full Text Available The paper presents a part of the work conducted in the first stage of a Research Grant called ”Hybrid micro-cogeneration group of high efficiency equipped with an electronically assisted ORC” acronym GRUCOHYB. The hybrid micro-cogeneration group is equipped with a four stroke Diesel engine having a maximum power of 40 kW. A mathematical model of the internal combustion engine is presented. The mathematical model is developed based on the Laws of Thermodynamics and takes into account the real, irreversible processes. Based on the mathematical model a computation program was developed. The results obtained were compared with those provided by the Diesel engine manufacturer. Results show a very high correlation between the manufacturer’s data and the simulation results for an engine running at 100% load. Future developments could involve using an exergetic analysis to show the ability of the ORC to generate electricity from recovered heat
Development of GaN-based micro chemical sensor nodes
Son, Kyung-ah; Prokopuk, Nicholas; George, Thomas; Moon, Jeong S.
2005-01-01
Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (High Electron Mobility Transistor) sensors to chemical toxins as well as other common gases.
Mathematical design of prokaryotic clone-based microarrays
Pieterse, B.; Quirijns, E.J.; Schuren, F.H.J.; Werf, van der M.J.
2005-01-01
Background - Clone-based microarrays, on which each spot represents a random genomic fragment, are a good alternative to open reading frame-based microarrays, especially for microorganisms for which the complete genome sequence is not available. Since the generation of a genomic DNA library is a ran
Mathematical design of prokaryotic clone-based microarrays
Pieterse, B.; Quirijns, E.J.; Schuren, F.H.J.; Werf, M.J. van der
2005-01-01
Background: Clone-based microarrays, on which each spot represents a random genomic fragment, are a good alternative to open reading frame-based microarrays, especially for microorganisms for which the complete genome sequence is not available. Since the generation of a genomic DNA library is a rand
Revilla, Marta; Galán, Berta; Viguri, Javier R
2016-07-01
An integrated mathematical model is proposed for modelling a moving bed biofilm reactor (MBBR) for removal of chemical oxygen demand (COD) under aerobic conditions. The composite model combines the following: (i) a one-dimensional biofilm model, (ii) a bulk liquid model, and (iii) biological processes in the bulk liquid and biofilm considering the interactions among autotrophic, heterotrophic and predator microorganisms. Depending on the values for the soluble biodegradable COD loading rate (SCLR), the model takes into account a) the hydrolysis of slowly biodegradable compounds in the bulk liquid, and b) the growth of predator microorganisms in the bulk liquid and in the biofilm. The integration of the model and the SCLR allows a general description of the behaviour of COD removal by the MBBR under various conditions. The model is applied for two in-series MBBR wastewater plant from an integrated cellulose and viscose production and accurately describes the experimental concentrations of COD, total suspended solids (TSS), nitrogen and phosphorous obtained during 14 months working at different SCLRs and nutrient dosages. The representation of the microorganism group distribution in the biofilm and in the bulk liquid allow for verification of the presence of predator microorganisms in the second reactor under some operational conditions.
Difficulties in solving context-based PISA mathematics tasks : An analysis of students' errors
Wijaya, Ariyadi; van den Heuvel-Panhuizen, Marja; Doorman, Michiel; Robitzsch, Alexander
2014-01-01
The intention of this study was to clarify students' difficulties in solving context-based mathematics tasks as used in the Programme for International Student Assessment (PISA). The study was carried out with 362 Indonesian ninth- and tenth-grade students. In the study we used 34 released PISA math
An Analysis of the Competency-Based Secondary Mathematics Curriculum in Sri Lanka
Egodawatte, Gunawardena
2014-01-01
In education, there is a growing interest in the concept of "competency" especially in vocational training and professional development. The concept is strongly associated with the ability to apply knowledge and skills in effective ways in unanticipated situations. In Sri Lanka, a new competency-based mathematics curriculum was…
Mathematics Achievement with Digital Game-Based Learning in High School Algebra 1 Classes
Ferguson, Terri Lynn Kurley
2014-01-01
This study examined the impact of digital game-based learning (DGBL) on mathematics achievement in a rural high school setting in North Carolina. A causal comparative research design was used in this study to collect data to determine the effectiveness of DGBL in high school Algebra 1 classes. Data were collected from the North Carolina…
Developing Teaching Materials PISA-Based for Mathematics and Science of Junior High School
Somakim; Suharman, Andi; Madang, Kodri; Taufiq
2016-01-01
This research aims to develop valid and practical teaching materials for mathematics and science lesson PISA-based for junior high school students and to determine potential effects on students in scientific activity. Subjects of this study were students of Junior High School 9 Palembang (SMP Negeri 9 Palembang). The method used in this study is…
Petersen, Richard H.
1997-01-01
The objectives of the Institute were: (a) increase participants' content knowledge about aeronautics, science, mathematics, and technology, (b) model and promote the use of scientific inquiry through problem-based learning, (c) investigate the use of instructional technologies and their applications to curricula, and (d) encourage the dissemination of TEI experiences to colleagues, students, and parents.
Using GIS to Teach Place-Based Mathematics in Rural Classrooms
Leonard, Jacqueline; Russell, Nicole M.; Hobbs, Robert M.; Buchanan, Heather
2013-01-01
The purpose of this article is to promote the use of GIS and place-based education (PBE) in rural mathematics classrooms. The pedagogy of place is disappearing from rural communities because of declining enrollments, lack of support, and federal mandates to focus more on basic academic skills. However, PBE does not stand in opposition to…
Analytical Derivation: An Epistemic Game for Solving Mathematically Based Physics Problems
Bajracharya, Rabindra R.; Thompson, John R.
2016-01-01
Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the "analytical derivation" game. This game involves deriving an…
Affording and Constraining Local Moral Orders in Teacher-Led Ability-Based Mathematics Groups
Tait-McCutcheon, Sandi; Shuker, Mary Jane; Higgins, Joanna; Loveridge, Judith
2015-01-01
How teachers position themselves and their students can influence the development of afforded or constrained local moral orders in ability-based teacher-led mathematics lessons. Local moral orders are the negotiated discursive practices and interactions of participants in the group. In this article, the developing local moral orders of 12 teachers…
Guzeller, Cem Oktay; Akin, Ayca
2014-01-01
The purpose of this study is to determine the predicting power of mathematics achievement from ICT variables including the Internet/entertainment use (IEU), program/software use (PRGUSE), confidence in internet tasks (INTCONF) and confidence in ICT high level tasks (HIGHCONF) based on PISA 2006 data. This study indicates that the ICT variables…
Magee, Paula A.; Flessner, Ryan
2012-01-01
This study examines the effect of promoting inquiry-based teaching (IBT) through collaboration between a science methods course and mathematics methods course in an elementary teacher education program. During the collaboration, preservice elementary teacher (PST) candidates experienced 3 different types of inquiry as a way to foster increased…
Psycharis, Sarantos
2016-01-01
Computational experiment approach considers models as the fundamental instructional units of Inquiry Based Science and Mathematics Education (IBSE) and STEM Education, where the model take the place of the "classical" experimental set-up and simulation replaces the experiment. Argumentation in IBSE and STEM education is related to the…
Mechanics-based mathematical studies proving spontaneity of post-impact WTC towers collapse
Le, Jia-Liang; Bažant, Zdeněk P.
2017-02-01
The cause of collapse of the World Trade Center (WTC) in New York on 9/11/2001, clarified mathematically by mechanical analysis, has been questioned by some lay critics without any meaningful calculations. They blame the collapse on controlled demolition, implying some sort of conspiracy. The present article summarizes the reasons why the collapse must have been spontaneous and an inevitable result of the aircraft impact damage and the subsequent fire, and how the collapse is explained by mathematical analysis based on mechanics and confirmed by all the available observations.
Designing Research-Based Professional Development for Elementary School Science and Mathematics
Directory of Open Access Journals (Sweden)
Brian L. Gerber
2011-01-01
Full Text Available A partnership including 11 school districts, a university, service agency, and private nonprofit education organization formed a collaborative partnership to improve teaching and learning in elementary school science and mathematics. The partnership designed research-based professional development for 150 teachers of grades 3–5. The professional development resulted in statistically significant increases for those elementary school teachers on math and science competency tests over a two-year period. The professional development was the vehicle for providing teachers with professional development so that they could (a increase their content background in science and mathematics and (b apply newly learned inquiry practices in their math and science instruction.
A method of building information extraction based on mathematical morphology and multiscale
Li, Jing-wen; Wang, Ke; Zhang, Zi-ping; Xue, Long-li; Yin, Shou-qiang; Zhou, Song
2015-12-01
In view of monitoring the changes of buildings on Earth's surface ,by analyzing the distribution characteristics of building in remote sensing image, combined with multi-scale in image segmentation and the advantages of mathematical morphology, this paper proposes a multi-scale combined with mathematical morphology of high resolution remote sensing image segmentation method, and uses the multiple fuzzy classification method and the shadow of auxiliary method to extract information building, With the comparison of k-means classification, and the traditional maximum likelihood classification method, the results of experiment object based on multi-scale combined with mathematical morphology of image segmentation and extraction method, can accurately extract the structure of the information is more clear classification data, provide the basis for the intelligent monitoring of earth data and theoretical support.
Enhancing Multiplier Speed in Fast Fourier Transform Based on Vedic Mathematics
Directory of Open Access Journals (Sweden)
D.Subathra
2013-07-01
Full Text Available Vedic mathematics is an ancient system of mathematics which has a unique technique of calculations basedon 16 sutras. The performance of high speed multiplier is designed based on Urdhva Tiryabhyam, NikhilamNavatashcaramam Dashatah, and Anurupye Vedic mathematical algorithms. These algorithms givesminimum delay and used for multiplication of all types of numbers. The performance of high speed multiplieris designed and compared using these sutras for various NxN bit multiplications and implemented on theFFT of the DSP processor. Anurupye sutra on FFT is made efficient than Urdhva tiryabhyam and NikhilamNavatashcaramam Dashatah sutras by more reduction in computation time. This gives the method forhierarchical multiplier design. Logic verification of these designs is verified by simulating the logic circuitsin XILINX ISE 9.1 and MODELSIM SE 5.7g using VHDL coding
Design-Based Research for Professional Learning for "Cultural Mathematics"
Kravia, Geori; Owens, Kay
2014-01-01
Design-based research is being used to develop and refine the principles used in professional learning workshops with teachers from three different Papua New Guinean ecologies: highlands, coastal, and inland in a coastal province. The appropriateness of the design of principles for Papua New Guinean Elementary Schools is tried over several phases…
Practice-based teacher education focused on mathematical discussions
2011-01-01
This paper presents a practice-based teacher education task and reflects on using with a group of experienced teachers. I begin sketching a rationale for using such tasks, then I present the context of this activity and conclude referring the value of this approach for in-service and pre-service teacher education.
The Mathematics of Divergence Based Online Learning in Vector Quantization
Villmann, Thomas; Haase, Sven; Schleif, Frank-Michael; Hammer, Barbara; Biehl, Michael
2010-01-01
We propose the utilization of divergences in gradient descent learning of supervised and unsupervised vector quantization as an alternative for the squared Euclidean distance. The approach is based on the determination of the Fréchet-derivatives for the divergences, wich can be immediately plugged i
Bioprocessing of bio-based chemicals produced from lignocellulosic feedstocks.
Kawaguchi, Hideo; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko
2016-12-01
The feedstocks used for the production of bio-based chemicals have recently expanded from edible sugars to inedible and more recalcitrant forms of lignocellulosic biomass. To produce bio-based chemicals from renewable polysaccharides, several bioprocessing approaches have been developed and include separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and consolidated bioprocessing (CBP). In the last decade, SHF, SSF, and CBP have been used to generate macromolecules and aliphatic and aromatic compounds that are capable of serving as sustainable, drop-in substitutes for petroleum-based chemicals. The present review focuses on recent progress in the bioprocessing of microbially produced chemicals from renewable feedstocks, including starch and lignocellulosic biomass. In particular, the technological feasibility of bio-based chemical production is discussed in terms of the feedstocks and different bioprocessing approaches, including the consolidation of enzyme production, enzymatic hydrolysis of biomass, and fermentation.
Directory of Open Access Journals (Sweden)
Adi Nurjaman
2017-01-01
Full Text Available The background of this study is the school of the new students of mathematics education courses came from grade high, medium and low. Here the writer wants to see how much influence of the school level on new students’ critical thinking skills and creative mathematical. The purpose of this study was to examine differences in new students’ mathematical disposition, critical & creative thinking ability through the mathematical problem posing approach based on school level (high, medium, low. The method used in this research is the experimental method, with only posttest design. The population of this study is all the students of mathematics education department in Cimahi; while the sample is selected randomly from one college. Then from this chosen college is taken two samples from random class. The instrument of essay test is used to measure students’ critical and mathematical creative thinking ability; while non-test instrument is questionnaire of attitude scale. The results show that: 1 based on the school level (high, medium, and low; there is difference in students’ mathematical critical thinking ability through problem posing approach. 2 based on the school level (high, medium, and low; there is difference in the students’ mathematical critical thinking ability through problem posing approach. 3 based on the school level (high, medium, and low; there is difference in students’ mathematical disposition.
Xianjun Li; Yongfeng Luo; Hongbin Chen; Xia He; Jianxiong Lv; Yiqiang Wu
2013-01-01
High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nanocomposites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased al...
Dedi Rohendi
2012-01-01
The purpose of this paper is to develop e-learning based on animation content for improving mathematical connection abilities in senior high school students. The e-learning was developed by using Moddle and the animation content was developed by using macromedia flash. To get the student mathematical conection abilities it uses the instruments of mathematical tests before and after teaching and learning process. The data were analyzed by using t-test and gain value test. The study found that ...
A pilot home-based early intervention study to improve the mathematical skills of young children
Directory of Open Access Journals (Sweden)
Ayşegül Şükran Öz
2013-12-01
Full Text Available Children who come from low socioeconomic backgrounds and children with learning disabilities are found to be at risk for future failure in mathematics. Even though the mathematics scores increases over time the achievement gap remains between the various ethnic and socioeconomic groups. One way to prevent this failure is to identify the students who are at risk and provide them with effective early intervention. This study reports the results of a pilot early mathematics intervention study focusing on two Turkish families in the US. In this single-subject research, a multiple probe technique was used in order to examine the impact of the SRA DLM Math Pre-K CD-ROM in combination with parent scaffolding on young children’s number sense skills. Two parent-child dyads participated in this study. Two semi-structured interviews were conducted with the parents before and after the intervention. The child participants received 3 Mathematical Curriculum Based Measure (CBM every week to monitor their progress. Building Blocks Assessment was used to identify whether children were able to generalize the number sense skills developed during work sessions in different settings. This measure was administered both before and after the intervention.This study demonstrated that children’s and parents’ use of a software program where they work collaboratively at home resulted in increased number sense skills. These results were interpreted in the context of socio-cultural theory. The parents displayed different strategies during the mathematics work sessions, reflecting their own feelings about mathematics and technology.
EXTENDING THE KNOWLEDGE BASE OF CHEMICAL ENGINEERING
Institute of Scientific and Technical Information of China (English)
Mooson Kwauk
2005-01-01
The obvious current reversion to micro-scale investigations in basic chemical engineering, combined with the need, of a quite different nature, in the rapid growth of high added-value and small-lot functional materials, have been pointing to an area not yet sufficiently covered by the unit operations, transport phenomena and chemical reaction engineering. Although it is difficult to define accurately this area, a cursory scan of the activities already in progress has revealed a few common attributes: multi-phased (structured), multi-scaled, multi-disciplined, nonlinear, needs for resolution to reductionism-solvable subsystems, and pervasive in the process industry. From these activities, the present paper drafts a tentative scheme for studying the related problems: first to dissect a problem into various scales - spatial, temporal or otherwise as best suits the case in hand- in order to identify pertinent parameters which are then organized into model formulations. Together with inter-scale model formulations, a zoom-in/zoom-out process is carried out between the scales, by trial-and-error and through reasoning, to arrive at a global formulation of a quantitative solution, in order to derive, eventually, the general from the particular.
Directory of Open Access Journals (Sweden)
Lei Chen
2013-01-01
Full Text Available A drug side effect is an undesirable effect which occurs in addition to the intended therapeutic effect of the drug. The unexpected side effects that many patients suffer from are the major causes of large-scale drug withdrawal. To address the problem, it is highly demanded by pharmaceutical industries to develop computational methods for predicting the side effects of drugs. In this study, a novel computational method was developed to predict the side effects of drug compounds by hybridizing the chemical-chemical and protein-chemical interactions. Compared to most of the previous works, our method can rank the potential side effects for any query drug according to their predicted level of risk. A training dataset and test datasets were constructed from the benchmark dataset that contains 835 drug compounds to evaluate the method. By a jackknife test on the training dataset, the 1st order prediction accuracy was 86.30%, while it was 89.16% on the test dataset. It is expected that the new method may become a useful tool for drug design, and that the findings obtained by hybridizing various interactions in a network system may provide useful insights for conducting in-depth pharmacological research as well, particularly at the level of systems biomedicine.
A decision analytic approach to exposure-based chemical prioritization.
Directory of Open Access Journals (Sweden)
Jade Mitchell
Full Text Available The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical's life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies.
PENGEMBANGAN WEB-BASED MATHEMATICS LEARNING SISWA KELAS V SDN KOTAGEDE 3 YOGYAKARTA
Directory of Open Access Journals (Sweden)
Titin Mulyaningsih
2015-07-01
Full Text Available Penelitian ini bertujuan untuk menghasilkan web-based mathematics learning yang layak untuk siswa kelas V di SD Kotagede 3 Yogyakarta. Disamping itu web-based mathematics learning yang dikembangkan dalam rangka menciptakan pembelajaran yang menyenangkan. Penelitian ini merupakan penelitian dan pengembangan yang terdiri dari 10 langkah kegiatan. Subjek penelitian ini adalah 32 siswa yang terdiri dari tiga siswa uji coba perorangan, 9 siswa uji coba kelompok kecil, dan 20 siswa uji coba lapangan. Instrumen yang digunakan dalam pengumpulan data adalah lembar validasi untuk ahli materi, ahli media dan angket tanggapan untuk siswa. Analisis data menggunakan analisis statistik deskripstif. Hasil validasi ahli materi menunjukkan skor rata-rata 80 yang termasuk kriteria sangat baik. Sedangkan hasil validasi ahli media menunjukkan skor rata-rata 70 termasuk dalam kriteria baik. Tanggapan siswa terhadap produk yang dikembangkan termasuk baik yaitu dengan perolehan skor rata-rata 17,9 atau sebesar 89,5% siswa menyatakan bahwa produk pengembangan ini layak untuk digunakan sebagai sumber belajar yang menyenangkan. Kata kunci: web-based learning, pembelajaran matematika DEVELOPING WEB-BASED MATHEMATICS LEARNING FOR THE FIFTH GRADE OF ELEMENTARY SCHOOL KOTAGEDE 3, YOGYAKARTA Abstract This study aims to produce a web-based mathematics learning viable for fifth grade students in elementary Kotagede 3 Yogyakarta. Besides, web-based learning mathematics developed in order to create a fun learning. This study is a research and development activities consist of 10 steps. The subjects were 32 students consisting of three students individual trials, nine trials a small group of students, and 20 students field trials. The instruments used in data collection is for the expert validation sheet material, media experts and questionnaire responses for the students. Analyzed using descriptive statistics. Matter expert validation results showed an average score of 80 which
Construction of a Linux based chemical and biological information system.
Molnár, László; Vágó, István; Fehér, András
2003-01-01
A chemical and biological information system with a Web-based easy-to-use interface and corresponding databases has been developed. The constructed system incorporates all chemical, numerical and textual data related to the chemical compounds, including numerical biological screen results. Users can search the database by traditional textual/numerical and/or substructure or similarity queries through the web interface. To build our chemical database management system, we utilized existing IT components such as ORACLE or Tripos SYBYL for database management and Zope application server for the web interface. We chose Linux as the main platform, however, almost every component can be used under various operating systems.
Prasanna, M D; Vondrasek, Jiri; Wlodawer, Alexander; Rodriguez, H; Bhat, T N
2006-06-01
A novel technique to annotate, query, and analyze chemical compounds has been developed and is illustrated by using the inhibitor data on HIV protease-inhibitor complexes. In this method, all chemical compounds are annotated in terms of standard chemical structural fragments. These standard fragments are defined by using criteria, such as chemical classification; structural, chemical, or functional groups; and commercial, scientific or common names or synonyms. These fragments are then organized into a data tree based on their chemical substructures. Search engines have been developed to use this data tree to enable query on inhibitors of HIV protease (http://xpdb.nist.gov/hivsdb/hivsdb.html). These search engines use a new novel technique, Chemical Block Layered Alignment of Substructure Technique (Chem-BLAST) to search on the fragments of an inhibitor to look for its chemical structural neighbors. This novel technique to annotate and query compounds lays the foundation for the use of the Semantic Web concept on chemical compounds to allow end users to group, sort, and search structural neighbors accurately and efficiently. During annotation, it enables the attachment of "meaning" (i.e., semantics) to data in a manner that far exceeds the current practice of associating "metadata" with data by creating a knowledge base (or ontology) associated with compounds. Intended users of the technique are the research community and pharmaceutical industry, for which it will provide a new tool to better identify novel chemical structural neighbors to aid drug discovery.
Chemical-potential-based Lattice Boltzmann Method for Nonideal Fluids
Wen, Binghai; He, Bing; Zhang, Chaoying; Fang, Haiping
2016-01-01
Chemical potential is an effective way to drive phase transition or express wettability. In this letter, we present a chemical-potential-based lattice Boltzmann model to simulate multiphase flows. The nonideal force is directly evaluated by a chemical potential. The model theoretically satisfies thermodynamics and Galilean invariance. The computational efficiency is improved owing to avoiding the calculation of pressure tensor. We have derived several chemical potentials of the popular equations of state from the free-energy density function. An effective chemical-potential boundary condition is implemented to investigate the wettability of a solid surface. Remarkably, the numerical results show that the contact angle can be linearly tuned by the surface chemical potential.
DEFF Research Database (Denmark)
Abd.Hamid, Mohd-Kamaruddin; Sin, Gürkan; Gani, Rafiqul
2010-01-01
In this paper, a novel systematic model-based methodology for performing integrated process design and controller design (IPDC) for chemical processes is presented. The methodology uses a decomposition method to solve the IPDC typically formulated as a mathematical programming (optimization...... that satisfy design, control and cost criteria. The advantage of the proposed methodology is that it is systematic, makes use of thermodynamic-process knowledge and provides valuable insights to the solution of IPDC problems in chemical engineering practice....... with constraints) problem. Accordingly the optimization problem is decomposed into four sub-problems: (i) pre-analysis, (ii) design analysis, (iii) controller design analysis, and (iv) final selection and verification, which are relatively easier to solve. The methodology makes use of thermodynamic-process...
Leh, Jayne M.; Jitendra, Asha K.; Caskie, Grace I. L.; Griffin, Cynthia C.
2007-01-01
The purpose of this study was to examine the tenability of a curriculum-based mathematical word problem-solving (WPS) measure as a progress-monitoring tool to index students' rate of growth or slope of achievement over time. Participants consisted of 58 third-grade students, who were assessed repeatedly over 16 school weeks. Students were measured…
Widyatiningtyas, Reviandari; Kusumah, Yaya S.; Sumarmo, Utari; Sabandar, Jozua
2015-01-01
The study reported the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students' prior mathematical ability to student's mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from…
Canturk-Gunhan, Berna; Bukova-Guzel, Esra; Ozgur, Zekiye
2012-01-01
The purpose of this study is to determine prospective mathematics teachers' views about using problem-based learning (PBL) in statistics teaching and to examine their thought processes. It is a qualitative study conducted with 15 prospective mathematics teachers from a state university in Turkey. The data were collected via participant observation…
McLoughlin, M. Padraig M. M.
2008-01-01
The author of this paper submits the thesis that learning requires doing; only through inquiry is learning achieved, and hence this paper proposes a programme of use of a modified Moore method in a Probability and Mathematical Statistics (PAMS) course sequence to teach students PAMS. Furthermore, the author of this paper opines that set theory…
Athappilly, Kuriakose; And Others
1983-01-01
The aggregate findings of experiments with modern mathematics for the last 30 years show that there have not been many detrimental effects of "new math" either on achievement or attitude. Instead, the evidence points toward beneficial effects in terms of improvement in overall achievement and attitude. (Author/BW)
DEFF Research Database (Denmark)
Carugati, Andrea
2002-01-01
has been initiated with the scope of investigating the questions that mathematical modelling technology poses to traditional information systems development projects. Based on the past body of research, this study proposes a framework to guide decision making for managing projects of information......’ skills in the development process. Further observations also indicate that flexibility and adaptability, based on grounded theory, are valuable tools when information systems development involves a new technology.......The advancements in complexity and sophistication of mathematical models for manufacturing scheduling and control and the increase of the ratio power/cost of computers are beginning to provide the manufacturing industry with new software tools to improve production. A Danish action research project...
Institute of Scientific and Technical Information of China (English)
JIA Jin-zhang
2008-01-01
The occurrence of local circulating ventilation can be caused by many factors,such as the airflow reversion during mine fire, the improper arrangement of local fan or underground fan station and the man-made error input of raw data before network solving.Once circulating ventilations occur, the corresponding branches in the ventilation network corresponding to the relevant airways in ventilation system form circuits, and all the directions of the branches in the circuits are identical, which is the unidirectional problem in ventilation network. Based on the properties of node adjacent matrix, a serial of mathematical computation to node adjacent matrix were performed, and a mathematical model for determining unidirectional circuits based on node adjacent matrix was put forward.
Zhao, Hui; Wei, Jingxuan
2014-09-01
The key to the concept of tunable wavefront coding lies in detachable phase masks. Ojeda-Castaneda et al. (Progress in Electronics Research Symposium Proceedings, Cambridge, USA, July 5-8, 2010) described a typical design in which two components with cosinusoidal phase variation operate together to make defocus sensitivity tunable. The present study proposes an improved design and makes three contributions: (1) A mathematical derivation based on the stationary phase method explains why the detachable phase mask of Ojeda-Castaneda et al. tunes the defocus sensitivity. (2) The mathematical derivations show that the effective bandwidth wavefront coded imaging system is also tunable by making each component of the detachable phase mask move asymmetrically. An improved Fisher information-based optimization procedure was also designed to ascertain the optimal mask parameters corresponding to specific bandwidth. (3) Possible applications of the tunable bandwidth are demonstrated by simulated imaging.
Chemical characterization of carbohydrate-based biosurfactants
High-yield, glycolipid-based biosurfactants are of increasing interest for use in environmentally benign cleaning or emulsifying agents. We have developed a MALDI-TOF/MS screen for the rapid analysis of several types of biosurfactants, including various acylated rhamnolipids in Pseudomonas extracts...
Exact computation of emergy based on a mathematical reinterpretation of the rules of emergy algebra
2012-01-01
cited By (since 1996)5; International audience; The emergy algebra is based on four rules, the use of which is sometimes confusing or reserved only to the experts of the domain. The emergy computation does not obey conservation logic (i.e. emergy computation does not obey Kirchoff-like circuit law). In this paper the authors propose to reformulate the emergy rules into three axioms which provide (i) a rigourous mathematical framework for emergy computation and (ii) an exact recursive algorith...
Prejean-Harris, Rose M.
Over the last decade, accountability has been the driving force for many changes in education in the United States. One major educational reform effort is the standards-based movement with a focus of combining a number of processes that involve aligning curriculum, instruction, assessment and feedback to specific standards that are measureable and indicative of student achievement. The purpose of this study is to determine if the type of report card is a possible predictor of third grade student achievement on standardized tests in mathematics and science for the 2012 Criterion-Referenced Competency Test (CRCT). The results of this study concluded that the difference in test scores in mathematics and science for students in the traditional report card group was not statistically significant when compared to the scores of students in the standards-based report card group when controlling for poverty level, school locale, and school district. However, students in the traditional report card group scored an average of 1.01 point higher in mathematics and 2.27 points higher in science than students in the standards-based report card group.
Geroch, Robert
1985-01-01
Mathematical Physics is an introduction to such basic mathematical structures as groups, vector spaces, topological spaces, measure spaces, and Hilbert space. Geroch uses category theory to emphasize both the interrelationships among different structures and the unity of mathematics. Perhaps the most valuable feature of the book is the illuminating intuitive discussion of the ""whys"" of proofs and of axioms and definitions. This book, based on Geroch's University of Chicago course, will be especially helpful to those working in theoretical physics, including such areas as relativity, particle
Directory of Open Access Journals (Sweden)
Dedi Rohendi
2012-07-01
Full Text Available The purpose of this paper is to develop e-learning based on animation content for improving mathematical connection abilities in senior high school students. The e-learning was developed by using Moddle and the animation content was developed by using macromedia flash. To get the student mathematical conection abilities it uses the instruments of mathematical tests before and after teaching and learning process. The data were analyzed by using t-test and gain value test. The study found that e-learning based on animation content not only had significant influence toward mathematical connection abilities but also able to improve students mathematical connection abilities far better than that of conventional approach.
Chemical Sensors Based on Piezoresistive Cantilever Array
Institute of Scientific and Technical Information of China (English)
于晓梅; 张大成; 王丛舜; 杜先锋; 王小宝; 阮勇
2003-01-01
U-shaped and rectangle piezoresistive cantilever arrays have been designed with the analysing results of stress,noise and sensitivity of the cantilevers. Based on silicon micromachining technology, the piezoresistive cantilevers were fabricated by using polysilicon as the piezoresistive materials. With the measurement results of noise and sensitivity, the Hooge factor is calculated to be 3 × 10-3, the gauge factor is 27, and the minimum detectable deflection of piezoresistive cantilevers are calculated to be 1.0nm for rectangle cantilever and 0.5 nm for the Ushaped cantilever at a 6 V bias voltage and a 1000 Hz measurement bandwidth. Using polymer-coated cantilevers as individual sensors, their responses to water vapour and ammonia were tested by measuring their output voltage signals. The measured results show that the sensor sensitivity to ammonia can reach a few ppm and the sensor responses are quick.
Piezoresistive Chemical Sensors Based on Functionalized Hydrogels
Directory of Open Access Journals (Sweden)
Margarita Guenther
2014-06-01
Full Text Available Thin films of analyte-specific hydrogels were combined with microfabricated piezoresistive pressure transducers to obtain chemomechanical sensors that can serve as selective biochemical sensors for a continuous monitoring of metabolites. The gel swelling pressure has been monitored in simulated physiological solutions by means of the output signal of piezoresistive sensors. The interference by fructose, human serum albumin, pH, and ionic concentration on glucose sensing was studied. With the help of a database containing the calibration curves of the hydrogel-based sensors at different values of pH and ionic strength, the corrected values of pH and glucose concentration were determined using a novel calibration algorithm.
Chemical-Based Formulation Design: Virtual Experimentation
DEFF Research Database (Denmark)
Conte, Elisa; Gani, Rafiqul
This paper presents a software, the virtual Product-Process Design laboratory (virtual PPD-lab) and the virtual experimental scenarios for design/verification of consumer oriented liquid formulated products where the software can be used. For example, the software can be employed for the design...... system engineering community, it is possible now to replace, at least, some of the experimental steps with efficient and validated model-based approaches. For example, the search space can be significantly reduced through computer-aided screenings of the active ingredient (AI), the solvent mixture......, the additives and/or their mixtures (formulations). Therefore, the experimental resources can focus on a few candidate product formulations to find the best product. The virtual PPD-lab allows various options for experimentations related to design and/or verification of the product. For example, the selection...
Applying Mathematical Optimization Methods to an ACT-R Instance-Based Learning Model.
Directory of Open Access Journals (Sweden)
Nadia Said
Full Text Available Computational models of cognition provide an interface to connect advanced mathematical tools and methods to empirically supported theories of behavior in psychology, cognitive science, and neuroscience. In this article, we consider a computational model of instance-based learning, implemented in the ACT-R cognitive architecture. We propose an approach for obtaining mathematical reformulations of such cognitive models that improve their computational tractability. For the well-established Sugar Factory dynamic decision making task, we conduct a simulation study to analyze central model parameters. We show how mathematical optimization techniques can be applied to efficiently identify optimal parameter values with respect to different optimization goals. Beyond these methodological contributions, our analysis reveals the sensitivity of this particular task with respect to initial settings and yields new insights into how average human performance deviates from potential optimal performance. We conclude by discussing possible extensions of our approach as well as future steps towards applying more powerful derivative-based optimization methods.
Multiple-optima search method based on a metamodel and mathematical morphology
Li, Yulin; Liu, Li; Long, Teng; Chen, Xin
2016-03-01
This article investigates a non-population-based optimization method using mathematical morphology and the radial basis function (RBF) for multimodal computationally intensive functions. To obtain several feasible solutions, mathematical morphology is employed to search promising regions. Sequential quadratic programming is used to exploit the possible areas to determine the exact positions of the potential optima. To relieve the computational burden, metamodelling techniques are employed. The RBF metamodel in different iterations varies considerably so that the positions of potential optima are moving during optimization. To find the pair of correlative potential optima between the latest two iterations, a tolerance is presented. Furthermore, to ensure that all the output minima are the global or local optima, an optimality judgement criterion is introduced.
Phase errors elimination in compact digital holoscope (CDH) based on a reasonable mathematical model
Wen, Yongfu; Qu, Weijuan; Cheng, Cheeyuen; Wang, Zhaomin; Asundi, Anand
2015-03-01
In the compact digital holoscope (CDH) measurement process, theoretically, we need to ensure the distances between the reference wave and object wave to the hologram plane exactly match. However, it is not easy to realize in practice due to the human factors. This can lead to a phase error in the reconstruction result. In this paper, the strict theoretical analysis of the wavefront interference is performed to demonstrate the mathematical model of the phase error and then a phase errors elimination method is proposed based on the advanced mathematical model, which has a more explicit physical meaning. Experiments are carried out to verify the performance of the presented method and the results indicate that it is effective and allows the operator can make operation more flexible.
Directory of Open Access Journals (Sweden)
Samuel Adejare Awolola
2011-06-01
Full Text Available One dominant factor on how well students learn mathematics is the quality of teaching. Studies have shown that typical mathematics classroom is frosted with teaching technique that centered on explain – practice – memorize. There is a paucity particularly in Nigeria. This study therefore, investigated the effect of brain-based learning strategy on the achievement regarding the learning of Mathematics of 522 Senior Secondary School Students in Oyo State, Nigeria. The moderator effect of cognitive style was also examined on independent variable (instructional strategy and dependent variable (mathematics achievement. The study adopted a pretest-posttest non-equivalent control group design in a quasi – experimental setting. The ANCOVA statistic was used to analyzed the data collected fro the study. The result revealed significant main effect of treatment, (F(1,510 = 75.0; P < 0.05, cognitive style (F(1,510 = 23.78; P < 0.05 and significant interaction effect of treatment and cognitive style (F(1,510 = 5.027; P < 0.05 on achievement in mathematics. The result showed that brain-based instructional strategy enhanced students’ achievement in mathematics more than the conventional lecture method. It is therefore recommended that Teachers of mathematics should adopt the strategy in teaching mathematics in senior secondary school.
Rubin, Andrew
2014-01-01
This book presents concise descriptions and analysis of the classical and modern models used in mathematical biophysics. The authors ask the question "what new information can be provided by the models that cannot be obtained directly from experimental data?" Actively developing fields such as regulatory mechanisms in cells and subcellular systems and electron transport and energy transport in membranes are addressed together with more classical topics such as metabolic processes, nerve conduction and heart activity, chemical kinetics, population dynamics, and photosynthesis. The main approach is to describe biological processes using different mathematical approaches necessary to reveal characteristic features and properties of simulated systems. With the emergence of powerful mathematics software packages such as MAPLE, Mathematica, Mathcad, and MatLab, these methodologies are now accessible to a wide audience. Provides succinct but authoritative coverage of a broad array of biophysical topics and models Wr...
Efficient exploration of chemical space by fragment-based screening.
Hall, Richard J; Mortenson, Paul N; Murray, Christopher W
2014-01-01
Screening methods seek to sample a vast chemical space in order to identify starting points for further chemical optimisation. Fragment based drug discovery exploits the superior sampling of chemical space that can be achieved when the molecular weight is restricted. Here we show that commercially available fragment space is still relatively poorly sampled and argue for highly sensitive screening methods to allow the detection of smaller fragments. We analyse the properties of our fragment library versus the properties of X-ray hits derived from the library. We particularly consider properties related to the degree of planarity of the fragments.
CANCER – THE ULTIMATUM FROM OUR CHEMICAL BASED CIVILIZATION
Directory of Open Access Journals (Sweden)
Shibabrata Pattanayak
2014-06-01
Full Text Available Cumulative effect of regular consumption of low amount of a large number of synthetic chemicals may create ultimately an environment inside our body leading to gereration of several types of diseases. Moreover, either DNA molecule of some tissue may get irreversible genetic damage or mutations or some tissue may start to grow abnormally due to the effect of those chemicals, both of which can lead to cancer, slowly but inevitably. To live with lesser number of hazardous diseases and for a healthy future generation, we must have to be conscious about these dangerous aspects of our chemical based civilization
Computing multi-species chemical equilibrium with an algorithm based on the reaction extents
DEFF Research Database (Denmark)
Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.;
2013-01-01
A mathematical model for the solution of a set of chemical equilibrium equations in a multi-species and multiphase chemical system is described. The computer-aid solution of model is achieved by means of a Newton-Raphson method enhanced with a line-search scheme, which deals with the non-negative...
Plasmonics Based Harsh Environment Compatible Chemical Sensors
Energy Technology Data Exchange (ETDEWEB)
Michael Carpenter
2012-01-15
Au-YSZ, Au-TiO{sub 2} and Au-CeO{sub 2} nanocomposite films have been investigated as a potential sensing element for high-temperature plasmonic sensing of H{sub 2}, CO, and NO{sub 2} in an oxygen containing environment. The Au-YSZ and Au-TiO{sub 2} films were deposited using PVD methods, while the CeO{sub 2} thin film was deposited by molecular beam epitaxy (MBE) and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. Each of the films were characterized by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H{sub 2}, CO, and NO{sub 2} were performed at a temperature of 500Â°C in oxygen backgrounds of 5.0, 10, and ~21% O{sub 2}. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the respective metal oxides. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles or by changes in the dielectric constant surrounding the particles. Hyperspectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used on the Au-CeO{sub 2} results and showed separation between analytes as well as trends in gas concentration. Results indicate that each of the films are is selective towards O{sub 2}, H{sub 2}, CO, and NO{sub 2} in separate exposures. However, when the films were analyzed in a sensor array based experiment, ie simultaneous exposures to the target gases, PCA analysis of the combined response showed an even greater selective character towards the target gases. Combined
3DTS: A 3D tolerancing system based on mathematical definition
Institute of Scientific and Technical Information of China (English)
CAO Yan-long; LIU Yu-sheng; MAO Jian; YANG Jiang-xin
2006-01-01
Tolerance is almost ubiquitous during the whole product lift cycle and is imperative for seamless integration of CAD and CAM. Based on the mathematical definition of tolerance, a 3D tolerancing system, 3DTS, is presented with its design principle, system architecture and key functions. The following functional modules, tolerance modeling, semantics interpretation, 3D tolerance analysis, are described in detail. To make the tolerancing system robust and efficient, many techniques such as hierarchical tolerance representation, rule-based evaluation and non-intersection determination of tolerance zone have been devised.Tested by many samples, this system shows good robustness and practicability.
Nutti, Ylva Jannok
2013-03-01
The goal of Indigenous education is that it should be approached on the basis of the Indigenous language and culture; this is also the case with Sámi education. The Sámi School Board has stated that all teaching in Sámi schools should be culturally based, despite the fact that Sámi culture-based teaching is not specifically defined. Therefore, teachers themselves must adapt the teaching and as a result, usually no Sámi culture-based mathematics teaching takes place. The aim of this article is to discuss Indigenous teachers' experiences with designing and implementing culture-based mathematics activities in Sámi preschool and primary school. The teachers' work with culture-based mathematics activities took the form of Sámi cultural thematic work with ethnomathematical content, Multicultural school mathematics with Sámi cultural elements, and Sámi intercultural mathematics teaching. Culture-based mathematics activities took place within an action research study in the Swedish part of Sápmi. Sápmi comprises northern Norway, Sweden, and Finland, as well as the Kola Peninsula in Russia. In the action research study, six teachers conducted culture-based mathematics activities in preschool and primary school on the basis of the action research loop "plan-act-observe-reflect." During the study the teachers changed from a problem-focused perspective to a possibility-focused culture-based teaching perspective characterised by a self-empowered Indigenous teacher role, as a result of which they started to act as agents for Indigenous school change. The concept of "decolonisation" was visible in the teachers' narratives. The teachers' newly developed knowledge about the ethnomathematical research field seemed to enhance their work with Indigenous culture-based mathematics teaching.
Wright, Vince
2014-01-01
Pirie and Kieren (1989 "For the learning of mathematics", 9(3)7-11, 1992 "Journal of Mathematical Behavior", 11, 243-257, 1994a "Educational Studies in Mathematics", 26, 61-86, 1994b "For the Learning of Mathematics":, 14(1)39-43) created a model (P-K) that describes a dynamic and recursive process by which…
MATHEMATICAL MODEL OF OPTIMAL PROJECT PORTFOLIO FORMING BASED ON RANDOM FACTORS
Directory of Open Access Journals (Sweden)
I. A. Korkhina
2014-03-01
Full Text Available Purpose. To identify the ways of perspective development for railway transport one should solve the problem of forming the investment project portfolio. Thus, it is necessary to deal with uncertainty in the input data (prices of services, materials, energy products. To take into account this uncertainty it is proposed to use the developed model of stochastic programming. Methodology. For accounting of uncertain data the probabilistic limits on the quantities of resources, which are used in the project portfolio are imposed. As the objective function it is proposed to maximize the threshold, which with a given probability may exceed the planning interval of the net income. Findings. Stochastic programming model with line-by-line probabilistic constraints was obtained. Coefficients of this model are normally distributed random variables. Ratios, which allow calculating mathematical expectations and covariance matrices of these coefficients, were concluded. Originality. Known methods of forming the optimal project portfolio are based on the fact that all inputs are known exactly. On the basis of this consideration, the authors of works on the creating an optimal project portfolio have come to a scheme of deterministic mathematical programming. In this article we propose to take into account the uncertainty in the input data, which will increase the reliability of the portfolio effectiveness estimation through the use of stochastic mathematical programming scheme. Practical value. The developed model can be used in order to solve the planning problems of railway transport development.
Mathematics analysis of polymerase chain reaction kinetic curves.
Sochivko, D G; Fedorov, A A; Varlamov, D A; Kurochkin, V E; Petrov, R V
2016-01-01
The paper reviews different approaches to the mathematical analysis of polymerase chain reaction (PCR) kinetic curves. The basic principles of PCR mathematical analysis are presented. Approximation of PCR kinetic curves and PCR efficiency curves by various functions is described. Several PCR models based on chemical kinetics equations are suggested. Decision criteria for an optimal function to describe PCR efficiency are proposed.
Process Design and Evaluation for Chemicals Based on Renewable Resources
DEFF Research Database (Denmark)
Fu, Wenjing
One of the key steps in process design is choosing between alternative technologies, especially for processes producing bulk and commodity chemicals. Recently, driven by the increasing oil prices and diminishing reserves, the production of bulk and commodity chemicals from renewable feedstocks has...... development of chemicals based on renewable feedstocks. As an example, this thesis especially focuses on applying the methodology in process design and evaluation of the synthesis of 5-hydroxymethylfurfural (HMF) from the renewable feedstock glucose/fructose. The selected example is part of the chemoenzymatic...... gained considerable interest. Renewable feedstocks usually cannot be converted into fuels and chemicals with existing process facilities due to the molecular functionality and variety of the most common renewable feedstock (biomass). Therefore new types of catalytic methods as well as new types...
Chemical and structural effects of base modifications in messenger RNA
Harcourt, Emily M.; Kietrys, Anna M.; Kool, Eric T.
2017-01-01
A growing number of nucleobase modifications in messenger RNA have been revealed through advances in detection and RNA sequencing. Although some of the biochemical pathways that involve modified bases have been identified, research into the world of RNA modification -- the epitranscriptome -- is still in an early phase. A variety of chemical tools are being used to characterize base modifications, and the structural effects of known base modifications on RNA pairing, thermodynamics and folding are being determined in relation to their putative biological roles.
Structural and Chemical Diversity of Tl-Based Cuprate Superconductors
Institute of Scientific and Technical Information of China (English)
信赢
2003-01-01
The Tl-based cuprate superconductor family is the largest family in crystal structure and chemical composition among all high Tc cuprate superconductors. The Tl family can be divided into two sub-families, the Tl single layer family and the Tl double layer family, based on their crystal structural characteristics. The Tl single layer family is an ideal material for investigating the evolution of crystalline formation, charge carrier density, chemical composition, transport properties, superconductivity and their relationships. The Tl family contains almostall possible crystal structures discovered in high-Tc cuprate superconductors. Tl cuprate superconductors are of great importance not only in studying high-temperature superconductivity but also in commercial applications.
Detecting Chemically Modified DNA Bases Using Surface Enhanced Raman Spectroscopy.
Barhoumi, Aoune; Halas, Naomi J
2011-12-15
Post-translational modifications of DNA- changes in the chemical structure of individual bases that occur without changes in the DNA sequence- are known to alter gene expression. They are believed to result in frequently deleterious phenotypic changes, such as cancer. Methylation of adenine, methylation and hydroxymethylation of cytosine, and guanine oxidation are the primary DNA base modifications identified to date. Here we show it is possible to use surface enhanced Raman spectroscopy (SERS) to detect these primary DNA base modifications. SERS detection of modified DNA bases is label-free and requires minimal additional sample preparation, reducing the possibility of additional chemical modifications induced prior to measurement. This approach shows the feasibility of DNA base modification assessment as a potentially routine analysis that may be further developed for clinical diagnostics.
Solving chemical dynamic optimization problems with ranking-based differential evolution algorithms
Institute of Scientific and Technical Information of China (English)
Xu Chen; Wenli Du; Feng Qian
2016-01-01
Dynamic optimization problems (DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-differentiable or explicit mathematical descriptions do not exist. Recently, evolutionary algorithms are gaining popularity for DOPs as they can be used as robust alternatives when the deterministic techniques are in-valid. In this article, a technology named ranking-based mutation operator (RMO) is presented to enhance the previous differential evolution (DE) algorithms to solve DOPs using control vector parameterization. In the RMO, better individuals have higher probabilities to produce offspring, which is helpful for the performance enhancement of DE algorithms. Three DE-RMO algorithms are designed by incorporating the RMO. The three DE-RMO algorithms and their three original DE algorithms are applied to solve four constrained DOPs from the literature. Our simulation results indicate that DE-RMO algorithms exhibit better performance than previous non-ranking DE algorithms and other four evolutionary algorithms.
A Generalized Recursive Algorithm for Binary Multiplication based on Vedic Mathematics
Kale, Ajinkya; Joglekar, Ashish
2009-01-01
A generalized algorithm for multiplication is proposed through recursive application of the Nikhilam Sutra from Vedic Mathematics, operating in radix - 2 number system environment suitable for digital platforms. Statistical analysis has been carried out based on the number of recursions profile as a function of the smaller multiplicand. The proposed algorithm is efficient for smaller multiplicands as well, unlike most of the asymptotically fast algorithms. Further, a basic block schematic of Hardware Implementation of our algorithm is suggested to exploit parallelism and speed up the implementation of the algorithm in a multiprocessor environment.
Perspectives of IT Artefacts: Information Systems based on Complex Mathematical Models
DEFF Research Database (Denmark)
Carugati, Andrea
2002-01-01
A solution for production scheduling that is lately attracting the interests of the manufacturing industry involves the use of complex mathematical modeling techniques in scheduling software. However this technology is fairly unknown among manufacturing practitioners, as are the social problems...... of its development and use. The aim of this article is to show how an approach based on multiple perspectives can help understand the emergence of complex software and help understand why and how the reasons and motives of the different stakeholders are, at times, incompatible....
Parshin, D. V.; Ufimtseva, I. V.; Cherevko, A. A.; Khe, A. K.; Orlov, K. Yu; Krivoshapkin, A. L.; Chupakhin, A. P.
2016-06-01
The present paper discusses the method of identification (diseased/healthy) human cerebral vessels by using of mathematical model. Human cerebral circulation as a single tuned circuit, which consists of blood flow, elastic vessels and elastic brain gel tissue is under consideration. Non linear Van der Pol-Duffing equation is assumed as mathematical model of cerebrovascular circulation. Hypothesis of vascular pathology existence in some position of blood vessel, based on mathematical model properties for this position is formulated. Good reliability of hypothesis is proved statistically for 7 patients with arterial aneurysms.
Alkhateeb, Haitham M
2002-02-01
This study was designed to compare achievement, attitudes toward success in mathematics, and mathematics anxiety of college students taught brief calculus using a graphic calculator, with the achievement and attitudes and anxiety of students taught using the computer algebra system Maple, using a technology based text book. 50 men and 50 women, students in three classes at a large public university in the southwestern United States, participated. Students' achievement in brief calculus was measured by performance on a teacher-made achievement test given at the end of the study. Analysis of variance showed no significant difference in achievement between the groups. To measure change in attitudes and anxiety, responses to paper-and-pencil inventories indicated significant differences in favor of students using the computer.
Chemical Information in Scirus and BASE (Bielefeld Academic Search Engine)
Bendig, Regina B.
2009-01-01
The author sought to determine to what extent the two search engines, Scirus and BASE (Bielefeld Academic Search Engines), would be useful to first-year university students as the first point of searching for chemical information. Five topics were searched and the first ten records of each search result were evaluated with regard to the type of…
Durable chemical sensors based on field-effect transistors
Reinhoudt, D.N.
1995-01-01
The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se
Najman, Laurent
2013-01-01
Mathematical Morphology allows for the analysis and processing of geometrical structures using techniques based on the fields of set theory, lattice theory, topology, and random functions. It is the basis of morphological image processing, and finds applications in fields including digital image processing (DSP), as well as areas for graphs, surface meshes, solids, and other spatial structures. This book presents an up-to-date treatment of mathematical morphology, based on the three pillars that made it an important field of theoretical work and practical application: a solid theoretical foun
Directory of Open Access Journals (Sweden)
Joseph Alia
2010-07-01
Full Text Available Chemists use one set of orbitals when comparing to a structural formula, hybridized AOs or NBOs for example, and another for reasoning in terms of frontier orbitals, MOs usually. Chemical arguments can frequently be made in terms of energy and/or electron density without the consideration of orbitals at all. All orbital representations, orthogonal or not, within a given function space are related by linear transformation. Chemical arguments based on orbitals are really energy or electron density arguments; orbitals are linked to these observables through the use of operators. The Valency Interaction Formula, VIF, offers a system of chemical reasoning based on the invariance of observables from one orbital representation to another. VIF pictures have been defined as one-electron density and Hamiltonian operators. These pictures are classified in a chemically meaningful way by use of linear transformations applied to them in the form of two pictorial rules and the invariance of the number of doubly, singly, and unoccupied orbitals or bonding, nonbonding, and antibonding orbitals under these transformations. The compatibility of the VIF method with the bond pair – lone pair language of Lewis is demonstrated. Different electron lone pair representations are related by the pictorial rules and have stability understood in terms of Walsh’s rules. Symmetries of conjugated ring systems are related to their electronic state by simple mathematical formulas. Description of lone pairs in conjugated systems is based on the strength and sign of orbital interactions around the ring. Simple models for bonding in copper clusters are tested, and the bonding of O2 to Fe(II in hemoglobin is described. Arguments made are supported by HF, B3LYP, and MP2 computations.
A novel mathematical technique to assess of the mitral valve dynamics based on echocardiography
Karvandi, Mersedeh; Hassantash, Seyed Ahmad; Foroughi, Mahnoosh
2015-01-01
Purpose: The mechanics of the mitral valve leaflet as a nonlinear, inelastic and anisotropic soft tissue results from an integrated response of many mathematical/physical indexes' that illustrate the tissue. In the past decade, finite element modeling of complete heart valves has greatly aided evaluation of heart valve surgery, design of bioprosthetic valve replacements, and general understanding of healthy and abnormal cardiac function. Such a model must be based on an accurate description of the mechanical behavior of the valve material. It is essential to calculate velocity/displacement and strain rate/strain at a component level that is to work at the cellular level. In this study we developed the first three-dimensional displacement vectors field in the characterization of mitral valve leaflets in continuum equations of inelasticity framework based on echocardiography. Method: Much of our knowledge of abnormal mitral valve function is based on surgical and post-mortem studies while these studies are quan...
Applied mathematics for science and engineering
Glasgow, Larry A
2014-01-01
Prepare students for success in using applied mathematics for engineering practice and post-graduate studies moves from one mathematical method to the next sustaining reader interest and easing the application of the techniques Uses different examples from chemical, civil, mechanical and various other engineering fields Based on a decade's worth of the authors lecture notes detailing the topic of applied mathematics for scientists and engineers Concisely writing with numerous examples provided including historical perspectives as well as a solutions manual for academic adopters
Progress in chemical luminescence-based biosensors: A critical review.
Roda, Aldo; Mirasoli, Mara; Michelini, Elisa; Di Fusco, Massimo; Zangheri, Martina; Cevenini, Luca; Roda, Barbara; Simoni, Patrizia
2016-02-15
Biosensors are a very active research field. They have the potential to lead to low-cost, rapid, sensitive, reproducible, and miniaturized bioanalytical devices, which exploit the high binding avidity and selectivity of biospecific binding molecules together with highly sensitive detection principles. Of the optical biosensors, those based on chemical luminescence detection (including chemiluminescence, bioluminescence, electrogenerated chemiluminescence, and thermochemiluminescence) are particularly attractive, due to their high-to-signal ratio and the simplicity of the required measurement equipment. Several biosensors based on chemical luminescence have been described for quantitative, and in some cases multiplex, analysis of organic molecules (such as hormones, drugs, pollutants), proteins, and nucleic acids. These exploit a variety of miniaturized analytical formats, such as microfluidics, microarrays, paper-based analytical devices, and whole-cell biosensors. Nevertheless, despite the high analytical performances described in the literature, the field of chemical luminescence biosensors has yet to demonstrate commercial success. This review presents the main recent advances in the field and discusses the approaches, challenges, and open issues, with the aim of stimulating a broader interest in developing chemical luminescence biosensors and improving their commercial exploitation.
Institute of Scientific and Technical Information of China (English)
LIN Hui; DU Pei-jun; ZHAO Chang-sheng; SHU Ning
2004-01-01
This paper puts forward an effective,specific algorithm for edge detection.Based on multi-structure elements of gray mathematics morphology,in the light of difference between noise and edge shape of RS images,the paper establishes multi-structure elements to detect edge by utilizing the grey form transformation principle.Compared with some classical edge detection operators,such as Sobel Edge Detection Operator,LOG Edge Detection Operator,and Canny Edge Detection Operator,the experiment indicates that this new algorithm possesses very good edge detection ability,which can detect edges more effectively,but its noise-resisting ability is relatively low.Because of the bigger noise of remote sensing image,the authors probe into putting forward other edge detection method based on combination of wavelet directivity checkout technology and small-scale Mathematical Morphology finally.So,position at the edge can be accurately located,the noise can be inhibited to a certain extent and the effect of edge detection is obvious.
Design and Simulation of Mathematical Models- An DSP and Digital Communication Based Approach
Directory of Open Access Journals (Sweden)
Miss. Shruti R. Tambakhe
2014-04-01
Full Text Available A methodology for implementing DSP based or communication applications on a field programmable gate arrays (FPGA using Xilinx System Generator (XSG for Matlab. The DPSK system and FFT are simulated using Matlab/ Simulink environment and System Generator, a tool from Xilinx used for FPGA design as well as implemented on Spartan 3E Starter Kit boards. We proposed the concept of simulation of mathematical model on mixed HDL-Simulink using Xilinx system generator. Many applications that are DSP based or certain communication application require mathematical modelling for their easy understanding and analysis. Due to its complexity Pure HDL is unable to simulate. Also it terms to be costly and time consuming process. The implementation of FFT algorithms that can compute fourier transform of varied signals in real time for frequency analysis of signals on FPGAs (Spartan3E. With large demand for high dynamic range for applications, floating point implementation is used as fixed point implementation becomes increasingly expensive. The DPSK model are first board behaves as a modulator and the second as a demodulator. The modulator and demodulator algorithms have been implemented on FPGA using the VHDL language on Xilinx ISE.
DEFF Research Database (Denmark)
Rees, Stephen Edward; Rychwicka-Kielek, Beate A; Andersen, Bjarne F
2012-01-01
Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission for exacerbat......Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission...... were assessed with previously defined rules. Differences between maximal changes of calculated and measured values were compared using a t-test, with trends analysed by inspection of plots. Results: Fifty-four patients, median age 67 years (range 62-75), were studied on average 3 days. Mean values of p......H, PCO2 and PO2 were 7.432±0.047, 6.8±1.7 kPa and 9.2±1.5 kPa, respectively. Calculated and measured arterial pH and PCO2 agreed well, differences having small bias and SD (0.000±0.022 pH, -0.06±0.50 kPa PCO2), significantly better than venous blood alone. Calculated PO2 obeyed the clinical rules...
The Big Fish-Little Pond Effect on Affective Factors Based on PISA 2012 Mathematics Achievement
Directory of Open Access Journals (Sweden)
Dilara BAKAN KALAYCIOĞLU
2017-03-01
Full Text Available In this study, the 2012 PISA Turkey student questionnaire data is considered to determine the big fish-little pond effect. The mathematics self-efficacy, self-concept and anxiety affective factors are examined to explain the relation of each of them with the school type, gender, socioeconomic status, student’s mathematics achievement and school’s mathematics achievement covariates. A total number of 771 students from 88 high schools are in the sample. Factor analyses’ results support the construct validity of the Student Questionnaire’s mathematics self-efficacy, anxiety and self-concept items. Data set is analyzed with Multiple Indicator Multiple Cause Model and the patterns of association with covariates and affective factors were tested simultaneously. According to the results, Anatolian high school students have a higher mathematics self-efficacy and lower mathematics anxiety than do the general high school students. However, when the student mathematics achievement and school mathematics achievement variables were inserted to the model, school type was not associated with mathematics self-efficacy. Moreover, Anatolian high school student’s mathematics anxiety was higher than that of the general high school students. Student’s mathematics achievement was the most significant predictor of the mathematics self-efficacy, anxiety and self-concept factors. Finally, school’s mathematics achievement was a significant predictor of only mathematics self-concept. The identification of increase in school’s mathematics achievement yields a decrease in the student’s mathematics self-concept may be considered as the most important result of this study. These results provide evidence about the Anatolian high schools’ students experience big fish-little pond effect.
A Systematic Methodology for Design of Emulsion Based Chemical Products
DEFF Research Database (Denmark)
Mattei, Michele; Kontogeorgis, Georgios; Gani, Rafiqul
2012-01-01
A systematic methodology for emulsion based chemical product design is presented. The methodology employs a model-based product synthesis/design stage and a modelexperiment based further refinement and/or validation stage. In this paper only the first stage is presented. The methodology employs...... a hierarchical approach starting with the identification of the needs to be satisfied by the emulsified product and then building up the formulation by adding one-by-one the different classes of chemicals. A structured database together with dedicated property prediction models and evaluation criteria...... are employed to obtain a list of formulations that satisfy constraints representing the desired needs (target properties). Through a conceptual case study dealing with the design of a sunscreen lotion, the application of this new methodology is illustrated....
Microstructural and Chemical Rejuvenation of a Ni-Based Superalloy
Yao, Zhiqi; Degnan, Craig C.; Jepson, Mark A. E.; Thomson, Rachel C.
2016-10-01
The microstructural evolution of the Ni-based superalloy CMSX-4 including the change in gamma prime morphology, size, and distribution after high-temperature degradation and subsequent rejuvenation heat treatments has been examined using field emission gun scanning electron microscopy and transmission electron microscopy. In this paper, it is shown that there are significant differences in the size of the `channels' between gamma prime particles, the degree of rafting, and the size of tertiary gamma prime particles in each of the different microstructural conditions studied. Chemical analysis has been carried out to compare rejuvenated and pre-service samples after the same subsequent degradation procedure. The results indicate that although the microstructures of pre-service and rejuvenated samples are similar, chemical differences are more pronounced in the rejuvenated samples, suggesting that chemical segregation from partitioning of the elements was not completely eliminated through the applied rejuvenation heat treatment. A number of modified rejuvenation heat treatment trials were carried out to reduce the chemical segregation prior to creep testing. The creep test results suggest that chemical segregation has an immeasurable influence on the short-term mechanical properties under the test conditions used here, indicating that further work is required to fully understand the suitability of specific rejuvenation heat treatments and their role in the extension of component life in power plant applications.
Microstructural and Chemical Rejuvenation of a Ni-Based Superalloy
Yao, Zhiqi; Degnan, Craig C.; Jepson, Mark A. E.; Thomson, Rachel C.
2016-12-01
The microstructural evolution of the Ni-based superalloy CMSX-4 including the change in gamma prime morphology, size, and distribution after high-temperature degradation and subsequent rejuvenation heat treatments has been examined using field emission gun scanning electron microscopy and transmission electron microscopy. In this paper, it is shown that there are significant differences in the size of the `channels' between gamma prime particles, the degree of rafting, and the size of tertiary gamma prime particles in each of the different microstructural conditions studied. Chemical analysis has been carried out to compare rejuvenated and pre-service samples after the same subsequent degradation procedure. The results indicate that although the microstructures of pre-service and rejuvenated samples are similar, chemical differences are more pronounced in the rejuvenated samples, suggesting that chemical segregation from partitioning of the elements was not completely eliminated through the applied rejuvenation heat treatment. A number of modified rejuvenation heat treatment trials were carried out to reduce the chemical segregation prior to creep testing. The creep test results suggest that chemical segregation has an immeasurable influence on the short-term mechanical properties under the test conditions used here, indicating that further work is required to fully understand the suitability of specific rejuvenation heat treatments and their role in the extension of component life in power plant applications.
Woodworth, William D.
Four mathematical/social studies module clusters are presented in an effort to develop proficiency in instruction and in inductive and deductive teaching procedures. Modules within the first cluster concern systems of numeration, set operations, numbers, measurement, geometry, mathematics, and reasoning. The second mathematical cluster presents…
Mathematical problems for chemistry students
Pota, Gyorgy
2011-01-01
Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistrystudents in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialistsof the chemistry-related fields (physicists, mathematicians, biologists, etc.) intothe world of the chemical applications.Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, others we
Tókés, B; Suciu, G; Nagy, G
2002-02-01
An extension of the retrometabolic based drug (chemical) design concept, specifically the soft drug approach, to the family of nitrone compounds is presented. Nitrones oppose oxidative challenges by virtue of their ability to very rapidly trap free radical species that are more stable and biochemically less harmful than the original molecular fragments. Moreover, the spin adducts may undergo further transformations including reaction with a second radical and decomposition (hydrolysis) to hydroxylamines and carbonyl compounds. Nitrones and their spin adducts may generate nitric oxide in vivo, which, like nitrones themselves, exerts a number of diverse activities in phylogenetically distant species as well as opposing effects in related biological systems. It was described as a major messenger in the cardiovascular, immune, and nervous systems, in which it plays regulatory, signaling, cytoprotective, and cytotoxic effects. Nitrones play an important role in the synthesis of drugs belonging to chemically and pharmacologically very different classes. A combined chemical-electrochemical synthesis of nitrones has been elaborated. These compounds may be obtained from aldehydes or ketones and N-substituted hydroxylamines. These reactions were performed directly, in situ in the electrochemical cell, where phenylhydroxylamine obtained by electroreduction of nitrobenzene derivatives reacts with the carbonyl compound introduced in the cell. The kinetic and thermodynamic parameters of the processes were determined by analyzing the adequate polarographic curves. Differences between purely chemical and mixed chemical-electrochemical methods are discussed. Analysis of the experimental data permits optimization of the investigated process from a preparative point of view. Effects of structural factors were systematically evaluated. The proposed method may be useful for combinatorial chemistry as well.
Institute of Scientific and Technical Information of China (English)
王定颖; 朱靖博; 丁燕; 寇自农; 杨兰苹
2014-01-01
The extracts from Chinese herbs are complex compounds with uncertain mechanism, which affects the target with all ingredients. Therefore,it is of great importance to evaluate the bioactivity of these extracts. In this study,29 samples which had continuous variation of constitu-ents were obtained from the alcohol extract of Terminalia chebula Retz. by a Sephadex LH-20 size exclusion chromatographic column. After detecting the chromatographic information of detection wavelength at 254 nm and the activity information of these samples,the mathematical relationship equation was established to determine the impact on the active components. Step-wise regression method was used to research the relationship between the peak areas(V i,inde-pendent variables)of the compositions in the samples and activities(according to the enzyme inhibition(W),dependent variables). The results showed that there were 55 chromatographic peaks in the samples and the mathematical relationship between the compositions of Terminalia chebula Retz. extract(V i ,i = 1,2,…,55)and activities was certain. The expression was:W =V7 ×(-0. 034±0. 013)+V18 ×(-0. 155±0. 051)+V29 ×( -0. 142±0. 028)+V 4 ×(0. 079±0. 020)+V 11 ×(0. 074± 0. 028)+V36 ×( -0. 117±0. 053)+85. 669±4. 476,multiple correlation coefficient R = 0. 854,signifi-cance level(Sig. F change)= 0. 037. The steadiness of model was favorable with new digital infor-mation. The compounds corresponding to 18 th ,29 th ,36 th ,4 th ,11 th and 7 th peaks were the main active compounds. The method can be also applied to the relationship between a wide variety of components of traditional Chinese medicine resources and different kinds of activities. It is signif-icant to the research and development of traditional Chinese medicine.%中药提取物是一个组成复杂、机理不明晰的混合物体系，其对靶标的作用是其中所有化合物的综合影响，如何表征和评价其生物活性值得深入研究。本文采用羟
Mathematical Modeling of Biosensors Based on an Array of Enzyme Microreactors
Directory of Open Access Journals (Sweden)
Juozas Kulys
2006-04-01
Full Text Available This paper presents a two-dimensional-in-space mathematical model ofbiosensors based on an array of enzyme microreactors immobilised on a single electrode.The modeling system acts under amperometric conditions. The microreactors were modeledby particles and by strips. The model is based on the diffusion equations containing a non-linear term related to the Michaelis-Menten kinetics of the enzymatic reaction. The modelinvolves three regions: an array of enzyme microreactors where enzyme reaction as well asmass transport by diffusion takes place, a diffusion limiting region where only the diffusiontakes place, and a convective region, where the analyte concentration is maintained constant.Using computer simulation, the influence of the geometry of the microreactors and of thediffusion region on the biosensor response was investigated. The digital simulation wascarried out using the finite difference technique.
Problem-based learning biotechnology courses in chemical engineering.
Glatz, Charles E; Gonzalez, Ramon; Huba, Mary E; Mallapragada, Surya K; Narasimhan, Balaji; Reilly, Peter J; Saunders, Kevin P; Shanks, Jacqueline V
2006-01-01
We have developed a series of upper undergraduate/graduate lecture and laboratory courses on biotechnological topics to supplement existing biochemical engineering, bioseparations, and biomedical engineering lecture courses. The laboratory courses are based on problem-based learning techniques, featuring two- and three-person teams, journaling, and performance rubrics for guidance and assessment. Participants initially have found them to be difficult, since they had little experience with problem-based learning. To increase enrollment, we are combining the laboratory courses into 2-credit groupings and allowing students to substitute one of them for the second of our 2-credit chemical engineering unit operations laboratory courses.
Directory of Open Access Journals (Sweden)
Sayantan Nath
2015-09-01
Full Text Available In this paper, integration between multiple functions of image processing and its statistical parameters for intelligent alarming series based fire detection system is presented. The proper inter-connectivity mapping between processing elements of imagery based on classification factor for temperature monitoring and multilevel intelligent alarm sequence is introduced by abstractive canonical approach. The flow of image processing components between core implementation of intelligent alarming system with temperature wise area segmentation as well as boundary detection technique is not yet fully explored in the present era of thermal imaging. In the light of analytical perspective of convolutive functionalism in thermal imaging, the abstract algebra based inter-mapping model between event-calculus supported DAGSVM classification for step-by-step generation of alarm series with gradual monitoring technique and segmentation of regions with its affected boundaries in thermographic image of coal with respect to temperature distinctions is discussed. The connectedness of the multifunctional operations of image processing based compatible fire protection system with proper monitoring sequence is presently investigated here. The mathematical models representing the relation between the temperature affected areas and its boundary in the obtained thermal image defined in partial derivative fashion is the core contribution of this study. The thermal image of coal sample is obtained in real-life scenario by self-assembled thermographic camera in this study. The amalgamation between area segmentation, boundary detection and alarm series are described in abstract algebra. The principal objective of this paper is to understand the dependency pattern and the principles of working of image processing components and structure an inter-connected modelling technique also for those components with the help of mathematical foundation.
Leh, Jayne
2011-01-01
Substantial evidence indicates that teacher-delivered schema-based instruction (SBI) facilitates significant increases in mathematics word problem solving (WPS) skills for diverse students; however research is unclear whether technology affordances facilitate superior gains in computer-mediated (CM) instruction in mathematics WPS when compared to…
DEFF Research Database (Denmark)
Westphael, Henning; Mogensen, Arne
2013-01-01
In this article we present the notion of Mathematical competences as a tool to describe the mathematically gifted students.......In this article we present the notion of Mathematical competences as a tool to describe the mathematically gifted students....
Improving Mathematical Optimization Techniques with the Aid of Exergy-Based Variables
Directory of Open Access Journals (Sweden)
George Tsatsaronis
2009-06-01
Full Text Available
The design optimization of energy conversion plants requires sophisticated optimization techniques. The usefulness of mathematical programming approaches has been discussed in several papers. Usually, the quality of the computed solutions, concerning global optimality and the convergence speed, is not discussed in these papers and even the existence of local optimal solutions is not mentioned. Indeed, the optimization of nonconvex mixed integer non-linear problems (MINLP, such as the structural and design optimization of power plants, is a very difficult problem. However, knowledge of the real optimization potential can assist the design engineer in better understanding the optimization procedure. This article deals with the use of exergetic variables for improving the quality of results obtained from mathematical optimization techniques and their convergence speed. LaGO, the solver used to compute the discussed results, can evaluate the obtained solution of the discussed minimization problems by calculating lower bounds of the original problem based on a relaxed convex objective function. Here, the use of exergetic variables can help to increase the lower bounds significantly and thus, to improve the evaluation of the computed solutions and the convergence speed. The method is applied to different optimization tasks.
Road extraction in remote sensing images based on PCNN and mathematical morphology
Wang, Ximing; Zhao, Hongrui; Tang, Zhongshi; Fu, Gang
2009-08-01
The extraction of roads from high spatial resolution remote sensing images remains a problem though lots of efforts have been made in this area. High spatial resolution remote sensing images represent the surface of the earth in detail. As spatial resolution increases, spectral variability within the road cover units becomes complex and traditional remote sensing image processing methods on pixel basis are no longer suitable. This paper studies automatic road extraction from remote sensing images based on methods of Pulse-Coupled Neural Network and mathematical morphology. PCNN is a useful biologically inspired algorithm, and has the properties of linking field and dynamic threshold which make similar neurons generate pulses simultaneously. PCNN has the ability of a neuron to capture neighboring neurons which are in similar states and the independency of the pulses within unattached neuron regions. The method of mathematical morphology has the prime principle which is using a certain structure element to measure and extract the corresponding form in an image. In this paper, the simplified PCNN is applied as the image segmentation algorithm, and morphological transformation is used to purify the roads' information and to extract the road centerlines. Experimental results show that this method is efficient in road extraction from remote sensing images.
Optimization of Cooling Process of Iron Ore Pellets Based on Mathematical Model and Data Mining
Institute of Scientific and Technical Information of China (English)
Gui-ming YANG; Xiao-hui FAN; Xu-ling CHEN; Xiao-xian HUANG; Xi LI
2015-01-01
Cooling process of iron ore pellets in a circular cooler has great impacts on the pellet quality and systematic energy exploitation. However, multi-variables and non-visualization of this gray system is unfavorable to efifcient production. Thus, the cooling process of iron ore pellets was optimized using mathematical model and data mining techniques. A mathematical model was established and validated by steady-state production data, and the results show that the calculated values coincide very well with the measured values. Based on the proposed model, effects of important process parameters on gas-pellet temperature proifles within the circular cooler were analyzed to better understand the entire cooling process. Two data mining techniques—Associa-tion Rules Induction and Clustering were also applied on the steady-state production data to obtain expertise operating rules and optimized targets. Finally, an optimized control strategy for the circular cooler was proposed and an operation guidance system was developed. The system could realize the visualization of thermal process at steady state and provide operation guidance to optimize the circular cooler.
Modelers' perception of mathematical modeling in epidemiology: a web-based survey.
Directory of Open Access Journals (Sweden)
Gilles Hejblum
Full Text Available BACKGROUND: Mathematical modeling in epidemiology (MME is being used increasingly. However, there are many uncertainties in terms of definitions, uses and quality features of MME. METHODOLOGY/PRINCIPAL FINDINGS: To delineate the current status of these models, a 10-item questionnaire on MME was devised. Proposed via an anonymous internet-based survey, the questionnaire was completed by 189 scientists who had published in the domain of MME. A small minority (18% of respondents claimed to have in mind a concise definition of MME. Some techniques were identified by the researchers as characterizing MME (e.g. Markov models, while others-at the same level of sophistication in terms of mathematics-were not (e.g. Cox regression. The researchers' opinions were also contrasted about the potential applications of MME, perceived as highly relevant for providing insight into complex mechanisms and less relevant for identifying causal factors. The quality criteria were those of good science and were not related to the size and the nature of the public health problems addressed. CONCLUSIONS/SIGNIFICANCE: This study shows that perceptions on the nature, uses and quality criteria of MME are contrasted, even among the very community of published authors in this domain. Nevertheless, MME is an emerging discipline in epidemiology and this study underlines that it is associated with specific areas of application and methods. The development of this discipline is likely to deserve a framework providing recommendations and guidance at various steps of the studies, from design to report.
Lee, Chang Jun
2015-01-01
In the fields of researches associated with plant layout optimization, the main goal is to minimize the costs of pipelines and pumping between connecting equipment under various constraints. However, what is the lacking of considerations in previous researches is to transform various heuristics or safety regulations into mathematical equations. For example, proper safety distances between equipments have to be complied for preventing dangerous accidents on a complex plant. Moreover, most researches have handled single-floor plant. However, many multi-floor plants have been constructed for the last decade. Therefore, the proper algorithm handling various regulations and multi-floor plant should be developed. In this study, the Mixed Integer Non-Linear Programming (MINLP) problem including safety distances, maintenance spaces, etc. is suggested based on mathematical equations. The objective function is a summation of pipeline and pumping costs. Also, various safety and maintenance issues are transformed into inequality or equality constraints. However, it is really hard to solve this problem due to complex nonlinear constraints. Thus, it is impossible to use conventional MINLP solvers using derivatives of equations. In this study, the Particle Swarm Optimization (PSO) technique is employed. The ethylene oxide plant is illustrated to verify the efficacy of this study.
Agent-Based Chemical Plume Tracing Using Fluid Dynamics
Zarzhitsky, Dimitri; Spears, Diana; Thayer, David; Spears, William
2004-01-01
This paper presents a rigorous evaluation of a novel, distributed chemical plume tracing algorithm. The algorithm is a combination of the best aspects of the two most popular predecessors for this task. Furthermore, it is based on solid, formal principles from the field of fluid mechanics. The algorithm is applied by a network of mobile sensing agents (e.g., robots or micro-air vehicles) that sense the ambient fluid velocity and chemical concentration, and calculate derivatives. The algorithm drives the robotic network to the source of the toxic plume, where measures can be taken to disable the source emitter. This work is part of a much larger effort in research and development of a physics-based approach to developing networks of mobile sensing agents for monitoring, tracking, reporting and responding to hazardous conditions.
Hiriart-Urruty, Jean-Baptiste
2016-01-01
This book contains a collection of exercises (called “tapas”) at undergraduate level, mainly from the fields of real analysis, calculus, matrices, convexity, and optimization. Most of the problems presented here are non-standard and some require broad knowledge of different mathematical subjects in order to be solved. The author provides some hints and (partial) answers and also puts these carefully chosen exercises into context, presents information on their origins, and comments on possible extensions. With stars marking the levels of difficulty, these tapas show or prove something interesting, challenge the reader to solve and learn, and may have surprising results. This first volume of Mathematical Tapas will appeal to mathematicians, motivated undergraduate students from science-based areas, and those generally interested in mathematics.
Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors
Directory of Open Access Journals (Sweden)
Zhenzhong Guo
2016-10-01
Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.
Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors
Zhenzhong Guo; Anca Florea; Mengjuan Jiang; Yong Mei; Weiying Zhang; Aidong Zhang; Robert Săndulescu; Nicole Jaffrezic-Renault
2016-01-01
The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF) for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclu...
Institute of Scientific and Technical Information of China (English)
LIANGDong; GAOJun; CAOWei; FUQizhong; ZHAOJing
2003-01-01
The license plate recognition (LPR), as an important measure of traffic controlling and information management, is being paid more and more attention. The location and detection of the inclined license plate is an important problem in the License Plate Recognition Sys-tem. But now most of the proposed location algorithms are based on the condition of the horizontal license. These methods don't work well on inclined license plate. At the same time, the method based on Hough Transform is pro-posed to detect the inclined angle of the license plate, but it has many limitations. In order to solve this problem,we propose a new method to locate the inclined plate region using Mathematical Morphology and Orientation Field. The algorithm consists of preprocessing, inclined an-gel detecting and license plate location modules. Firstly,we adopt the gray extension method to improve the ob-serving quality of the images and study the intrinsic char-acteristic of texture and shape of vehicle license, such as the size, space and height of characters, then we construct the morphologic operator to make a series of morphologicoperations and locate the plate region roughly in the pre-processed image; secondly we make the horizontal and ver-tical projection, get the coordinate of the down left corner and top right corner in the license plate, and detect the inclined angle of the license plate with Orientation Field;lastly, the results of projecting and Orientation Field cal-culating are used to locate the license plate precisely. We practise our method on images under different illumination condition, and the experimental results show that the accu-racy of inclined angel detection and license plate extraction based on Mathematical Morphology and Orientation Field is significant.
Kurtulus, Aytac
2013-01-01
The aim of this study was to investigate the effects of web-based interactive virtual tours on the development of prospective mathematics teachers' spatial skills. The study was designed based on experimental method. The "one-group pre-test post-test design" of this method was taken as the research model. The study was conducted with 3rd year…
Kanive, Rebecca; Nelson, Peter M.; Burns, Matthew K.; Ysseldyke, James
2014-01-01
The authors' purpose was to determine the effects of computer-based practice and conceptual interventions on computational fluency and word-problem solving of fourth- and fifth-grade students with mathematics difficulties. A randomized pretest-posttest control group design found that students assigned to the computer-based practice intervention…
Gunbas, Nilgun
2012-01-01
The purpose of this study was to investigate the effect of a computer-based story on sixth grade students' mathematics word problem solving achievement. Problems were embedded in a story presented on a computer, and then compared to a paper-based story and to a condition that presented the problems as typical, isolated words problems. One hundred…
Rule-Based Classification of Chemical Structures by Scaffold.
Schuffenhauer, Ansgar; Varin, Thibault
2011-08-01
Databases for small organic chemical molecules usually contain millions of structures. The screening decks of pharmaceutical companies contain more than a million of structures. Nevertheless chemical substructure searching in these databases can be performed interactively in seconds. Because of this nobody has really missed structural classification of these databases for the purpose of finding data for individual chemical substructures. However, a full deck high-throughput screen produces also activity data for more than a million of substances. How can this amount of data be analyzed? Which are the active scaffolds identified by an assays? To answer such questions systematic classifications of molecules by scaffolds are needed. In this review it is described how molecules can be hierarchically classified by their scaffolds. It is explained how such classifications can be used to identify active scaffolds in an HTS data set. Once active classes are identified, they need to be visualized in the context of related scaffolds in order to understand SAR. Consequently such visualizations are another topic of this review. In addition scaffold based diversity measures are discussed and an outlook is given about the potential impact of structural classifications on a chemically aware semantic web.
Lee, Kyungmin; Cho, Soohyun
2017-01-26
Mathematics anxiety (MA) refers to the experience of negative affect when engaging in mathematical activity. According to Ashcraft and Kirk (2001), MA selectively affects calculation with high working memory (WM) demand. On the other hand, Maloney, Ansari, and Fugelsang (2011) claim that MA affects all mathematical activities, including even the most basic ones such as magnitude comparison. The two theories make opposing predictions on the negative effect of MA on magnitude processing and simple calculation that make minimal demands on WM. We propose that MA has a selective impact on mathematical problem solving that likely involves processing of magnitude representations. Based on our hypothesis, MA will impinge upon magnitude processing even though it makes minimal demand on WM, but will spare retrieval-based, simple calculation, because it does not require magnitude processing. Our hypothesis can reconcile opposing predictions on the negative effect of MA on magnitude processing and simple calculation. In the present study, we observed a negative relationship between MA and performance on magnitude comparison and calculation with high but not low WM demand. These results demonstrate that MA has an impact on a wide range of mathematical performance, which depends on one's sense of magnitude, but spares over-practiced, retrieval-based calculation.
Mathematical Model for Tempering Time Effect on Quenched Steel Based on Hollomon Parameter
Institute of Scientific and Technical Information of China (English)
Nong WAN; Weihao XIONG; Jinping SUO
2005-01-01
Through the differentiating and integrating process, a mathematical model for tempering time effect on quenched steel was derived based on the attribute of state function and the general equation of Hollomon parameter, which correlates the tempering hardness with the tempering time at different tempering temperature. Using the established model, thelinear relationship between the tempering hardness and the tempering time in logarithm was proved theoretically, and the tempering hardness for various tempering time was reduced to the measurement and calculation of a hardness experiment tempered for 1 h at different tempering temperatures. Moreover, the hardness of steel 42CrMo and T8Mn tempered for various times at 200～600℃ was calculated using this method. The predicted results are in good agreement with those of the available experiments.
A new mathematical modelling based shape extraction technique for Forensic Odontology.
G, Jaffino; A, Banumathi; Gurunathan, Ulaganathan; B, Vijayakumari; J, Prabin Jose
2017-02-28
Forensic Odontology is a specific means for identifying a person in which deceased, and particularly in fatality incidents. The algorithm can be proposed to identify a person by comparing both postmortem (PM) and antemortem (AM) dental radiographs and photographs. This work aims to introduce a new mathematical algorithm for photographs in addition with radiographs. Isoperimetric graph partitioning method is used to extract the shape of dental images in forensic identification. Shape matching is done by comparing AM and PM dental images using both similarity and distance measures. Experimental results prove that the higher matching distance is observed by distance metric rather than similarity measures. The results of this algorithm show that a high hit rate is observed for distance based performance measures and it is well suited for forensic odontologist to identify a person.
A process-based mathematical model on methane production with emission indices for control.
Chakraborty, A; Bhattacharaya, D K
2006-08-01
In this paper, a process-based mathematical model is developed for the production of methane through biodegradation. It is a three-dimensional model given by ordinary differential equations. The results of the analysis of the model are interpreted through three emission indices, which are introduced for the first time. The estimation of either one or all of them can interpret the feasibility of the equilibrium and the long-term emission tendency of methane. The vulnerability of the methane production process with respect to soil temperature effects in methanogenic phase has been discussed and a feasible condition within a specified temperature range has defined for the nonvulnerability of the methane production process and also it has shown that under the same condition, zero-emission process of methane will be nonvulnerable with respect to the soil temperature effects in methanogenic phase. Lastly, condition for zero emission of methane is also obtained and it is interpreted through the emission indices.
DEFF Research Database (Denmark)
Carugati, Andrea
. The resulting methodology builds on these four results. The methodology is based on an emergent and iterative process focused on the discussion of software prototypes built as boundary objects: visual, usable, bi-directional, and up-to-date. Iterations are kept short so that the prototypes remain simple enough...... modeling (AMM) in scheduling and control systems. Advanced mathematical techniques are relatively new in scheduling and control systems, at least in real production situations, and therefore the project included the research of methods and tools for the development of these systems. Because of the novelty...... with a relativist approach. Arriving at the design of an ISD methodology required the combination of previous theoretical results with the observations from the case study. The case study showed some of the key elements to be integrated in the methodology. Firstly, plans and models are subject of a high degree...
Harper, Marc
2013-01-01
We show that individual topics and skills can have a dramatic effect on the outcomes of students in various mathematics courses at the University of Illinois. Data from the placement program at Illinois associates a knowledge state, a subset of 182 items and skills that a student is able to complete successfully and repeatedly, with their final grades in a variety of courses from college algebra through multivariate calculus. Using various conditional probabilities and odds ratios, we classify items based on their association with successful and unsuccessful course outcomes, showing that some skills that are advanced for some courses are fundamental or basic to more advanced courses. We examine the impact of specific items across the courses in the traditional college algebra, precalculus, and calculus sequence, as well as courses not typically covered by placement programs, such as higher calculus courses. Visualizations of the knowledge states associated to each student are given for some specific courses a...
Enhancing Multiplier Speed in Fast Fourier Transform Based on Vedic Mathematics
Directory of Open Access Journals (Sweden)
R.P.Meenaakshi Sundari,
2013-06-01
Full Text Available Vedic mathematics is an ancient system of mathemati cs which has a unique technique of calculations bas ed on 16 sutras. The performance of high speed multipl ier is designed based on Urdhva Tiryabhyam, Nikhila m Navatashcaramam Dashatah, and Anurupye Vedic mathem atical algorithms. These algorithms gives minimum delay and used for multiplication of all ty pes of numbers. The performance of high speed multi plier is designed and compared using these sutras for var ious NxN bit multiplications and implemented on the FFT of the DSP processor. Anurupye sutra on FFT is made efficient than Urdhva tiryabhyam and Nikhilam Navatashcaramam Dashatah sutras by more reduction i n computation time. This gives the method for hierarchical multiplier design. Logic verification of these designs is verified by simulating the logi c circuits in XILINX ISE 9.1 and MODELSIM SE 5.7g using VHDL c oding.
The Formalization of Syntax-Based Mathematical Algorithms Using Quotation and Evaluation
Farmer, William M.
2013-01-01
Algorithms like those for differentiating functional expressions manipulate the syntactic structure of mathematical expressions in a mathematically meaningful way. A formalization of such an algorithm should include a specification of its computational behavior, a specification of its mathematical meaning, and a mechanism for applying the algorithm to actual expressions. Achieving these goals requires the ability to integrate reasoning about the syntax of the expressions with reasoning about ...
Swars, Susan Lee
2015-01-01
This mixed methods study examined the mathematical preparation of elementary teachers in a Teach for America (TFA) program, focal participants for whom there is scant extant research. Data collection occurred before and after a university mathematics methods course, with a particular focus on the participants' (n = 22) mathematical beliefs,…
Energy Technology Data Exchange (ETDEWEB)
Salloum, Maher N.; Gharagozloo, Patricia E.
2013-10-01
Metal particle beds have recently become a major technique for hydrogen storage. In order to extract hydrogen from such beds, it is crucial to understand the decomposition kinetics of the metal hydride. We are interested in obtaining a a better understanding of the uranium hydride (UH3) decomposition kinetics. We first developed an empirical model by fitting data compiled from different experimental studies in the literature and quantified the uncertainty resulting from the scattered data. We found that the decomposition time range predicted by the obtained kinetics was in a good agreement with published experimental results. Secondly, we developed a physics based mathematical model to simulate the rate of hydrogen diffusion in a hydride particle during the decomposition. We used this model to simulate the decomposition of the particles for temperatures ranging from 300K to 1000K while propagating parametric uncertainty and evaluated the kinetics from the results. We compared the kinetics parameters derived from the empirical and physics based models and found that the uncertainty in the kinetics predicted by the physics based model covers the scattered experimental data. Finally, we used the physics-based kinetics parameters to simulate the effects of boundary resistances and powder morphological changes during decomposition in a continuum level model. We found that the species change within the bed occurring during the decomposition accelerates the hydrogen flow by increasing the bed permeability, while the pressure buildup and the thermal barrier forming at the wall significantly impede the hydrogen extraction.
A biophysically based mathematical model for the catalytic mechanism of glutathione reductase.
Pannala, Venkat R; Bazil, Jason N; Camara, Amadou K S; Dash, Ranjan K
2013-12-01
Glutathione reductase (GR) catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) using NADPH as the reducing cofactor, and thereby maintains a constant GSH level in the system. GSH scavenges superoxide (O2(*-)) and hydroxyl radicals (OH) nonenzymatically or by serving as an electron donor to several enzymes involved in reactive oxygen species (ROS) detoxification. In either case, GSH oxidizes to GSSG and is subsequently regenerated by the catalytic action of GR. Although the GR kinetic mechanism has been extensively studied under various experimental conditions with variable substrates and products, the catalytic mechanism has not been studied in terms of a mechanistic model that accounts for the effects of the substrates and products on the reaction kinetics. The aim of this study is therefore to develop a comprehensive mathematical model for the catalytic mechanism of GR. We use available experimental data on GR kinetics from various species/sources to develop the mathematical model and estimate the associated model parameters. The model simulations are consistent with the experimental observation that GR operates via both ping-pong and sequential branching mechanisms based on relevant concentrations of its reaction substrate GSSG. Furthermore, we show the observed pH-dependent substrate inhibition of GR activity by GSSG and bimodal behavior of GR activity with pH. The model presents a unique opportunity to understand the effects of products on the kinetics of GR. The model simulations show that under physiological conditions, where both substrates and products are present, the flux distribution depends on the concentrations of both GSSG and NADP(+), with ping-pong flux operating at low levels and sequential flux dominating at higher levels. The kinetic model of GR may serve as a key module for the development of integrated models for ROS-scavenging systems to understand protection of cells under normal and oxidative stress
Mathematical calibration procedure of a capacitive sensor-based indexed metrology platform
Brau-Avila, A.; Santolaria, J.; Acero, R.; Valenzuela-Galvan, M.; Herrera-Jimenez, V. M.; Aguilar, J. J.
2017-03-01
The demand for faster and more reliable measuring tasks for the control and quality assurance of modern production systems has created new challenges for the field of coordinate metrology. Thus, the search for new solutions in coordinate metrology systems and the need for the development of existing ones still persists. One example of such a system is the portable coordinate measuring machine (PCMM), the use of which in industry has considerably increased in recent years, mostly due to its flexibility for accomplishing in-line measuring tasks as well as its reduced cost and operational advantages compared to traditional coordinate measuring machines. Nevertheless, PCMMs have a significant drawback derived from the techniques applied in the verification and optimization procedures of their kinematic parameters. These techniques are based on the capture of data with the measuring instrument from a calibrated gauge object, fixed successively in various positions so that most of the instrument measuring volume is covered, which results in time-consuming, tedious and expensive verification and optimization procedures. In this work the mathematical calibration procedure of a capacitive sensor-based indexed metrology platform (IMP) is presented. This calibration procedure is based on the readings and geometric features of six capacitive sensors and their targets with nanometer resolution. The final goal of the IMP calibration procedure is to optimize the geometric features of the capacitive sensors and their targets in order to use the optimized data in the verification procedures of PCMMs.
Ataei, Sh; Mahmud, Z.; Khalid, M. N.
2014-04-01
The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.
Exploration of chemical space based on 4-anilinoquinazoline.
Li, D-D; Hou, Y-P; Wang, W; Zhu, H-L
2012-01-01
Chemical space is defined as all possible small organic molecules, including those present in biological systems, which is so vast that so far only a tiny fraction of it has been explored. Indeed, a thorough examination of all "chemical space" is practically impossible. The success of three EGFR inhibitors (Gefitnib, Erlotinib, Lapatinib) suggests that 4-anilinoquinazoline scaffold is still worth developing in the future. To date hundreds of this sort of derivatives have been synthesized and show potent anticancer activities. Most of the compounds have been proved to be EGFR/HER2 kinase inhibitors, binding at the hinge region of the ATP site and some lead compounds have been optimized against a number of different kinases, including VEGFR-2, Src, Aurora A/B, Tpl, Clk and PDE10A. Now there is now a rich pipeline of novel anticancer agents based on 4-anilinoquinazoline in early phase clinical trials. This review will highlight the exploration of chemical space of 4-anilinoquinazoline in the past ten years and we hope that increasing knowledge of the SAR and cellular processes underlying the antitumor-activity of anilinoquinazoline derivatives will be beneficial to the rational design of new generation of small molecule anticancer drugs.
Chemical sensors based on molecularly modified metallic nanoparticles
Energy Technology Data Exchange (ETDEWEB)
Haick, Hossam [Department of Chemical Engineering and Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000 (Israel)
2007-12-07
This paper presents a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to the use of molecularly modified metal nanoparticles in or as chemical sensors. This paper attempts to pull together different views and terminologies used in sensors based on molecularly modified metal nanoparticles, including those established upon electrochemical, optical, surface Plasmon resonance, piezoelectric and electrical transduction approaches. Finally, this paper discusses briefly the main advantages and disadvantages of each of the presented class of sensors. (review article)
Lai, Shu-Ling; Repman, Judith L.
1996-01-01
Purposes of this study were to determine: (1) if analogies and elaboration and placement of the analogies help novices learning a computer-programming language; (2) if students' mathematics ability influences programming learning; and (3) the interaction effects between analogy and mathematics ability. Subjects were 156 college students. Results…
Examining Student Opinions on Computer Use Based on the Learning Styles in Mathematics Education
Ozgen, Kemal; Bindak, Recep
2012-01-01
The purpose of this study is to identify the opinions of high school students, who have different learning styles, related to computer use in mathematics education. High school students' opinions on computer use in mathematics education were collected with both qualitative and quantitative approaches in the study conducted with a survey model. For…
The Use of ICT in Kindergarten for Teaching Addition Based on Realistic Mathematics Education
Zaranis, Nicholas
2016-01-01
The purpose of this study is to investigate if information and communications technology (ICT) helps improve kindergarten students' basic mathematical achievement regarding addition. Our research compares the level of mathematical competence of the students taught using our ICT oriented learning method which specifically takes advantage of…
Lecturers' Perspectives on the Use of a Mathematics-Based Computer-Aided Assessment System
Broughton, Stephen J.; Robinson, Carol L.; Hernandez-Martinez, Paul
2013-01-01
Computer-aided assessment (CAA) has been used at a university with one of the largest mathematics and engineering undergraduate cohorts in the UK for more than ten years. Lecturers teaching mathematics to first year students were asked about their current use of CAA in a questionnaire and in interviews. This article presents the issues that these…
Applying Mathematical Concepts with Hands-On, Food-Based Science Curriculum
Roseno, Ashley T.; Carraway-Stage, Virginia G.; Hoerdeman, Callan; Díaz, Sebastián R.; Geist, Eugene; Duffrin, Melani W.
2015-01-01
This article addresses the current state of the mathematics education system in the United States and provides a possible solution to the contributing issues. As a result of lower performance in primary mathematics, American students are not acquiring the necessary quantitative literacy skills to become successful adults. This study analyzed the…
Ramnarain, Umesh
2014-01-01
A major impediment to problem solving in mathematics in the great majority of South African schools is that disadvantaged students from seriously impoverished learning environments are lacking in the necessary informal mathematical knowledge to develop their own strategies for solving non-routine problems. A randomized pretest-posttest control…
Doabler, Christian T.; Nelson, Nancy J.; Clarke, Ben
2016-01-01
Convincing evidence suggests that a considerable number of U.S. students struggle to develop mathematics proficiency. One subgroup of students who have a high probability of mathematical failure is English learners (ELs), who now represent 10% of the U.S. student population; 70% of these students speak Spanish at home (Fry & Passel, 2009). ELs…
Classroom-Based Professional Expertise: A Mathematics Teacher's Practice with Technology
Bozkurt, Gulay; Ruthven, Kenneth
2017-01-01
This study examines the classroom practice and craft knowledge underpinning one teacher's integration of the use of GeoGebra software into mathematics teaching. The chosen teacher worked in an English secondary school and was professionally well regarded as an accomplished user of digital technology in mathematics teaching. Designed in accordance…
Action-Based Digital Tools: Mathematics Learning in 6-Year-Old Children
Dejonckheere, Peter J. N.; Desoete, Annemie; Fonck, Nathalie; Roderiguez, Dave; Six, Leen; Vermeersch, Tine; Vermeulen, Lies
2014-01-01
Introduction: In the present study we used a metaphorical representation in order to stimulate the numerical competences of six-year-olds. It was expected that when properties of physical action are used for mathematical thinking or when abstract mathematical thinking is grounded in sensorimotor processes, learning gains should be more pronounced…
Luther, Kenneth H.
2012-01-01
Mathematical modeling of groundwater flow is a topic at the intersection of mathematics and geohydrology and is rarely encountered in undergraduate mathematics. However, this subject is full of interesting and meaningful examples of truly "applied" mathematics accessible to undergraduates, from the pre-calculus to advanced mathematics levels. This…
2015-08-03
reporting period: Changes in research objectives (if any): Change in AFOSR Program Manager, if any: Extensions granted or milestones slipped, if any: AFOSR...LRIR Number LRIR Title Reporting Period Laboratory Task Manager Program Officer Research Objectives Technical Summary Funding Summary by Cost...AND SUBTITLE Mobile STEMship Discovery Center: K-12 Aerospace-Based Science, Technology, Engineering, and Mathematics (STEM) Mobile Teaching Vehicle
A biologically based mathematical model for the induction of liver tumors in mice by dichloroacetic acid (DCA) has been developed from histopathologic analysis of the livers of exposed mice. This analysis suggests that following chronic exposure to DCA, carcinomas can arise dire...
Ruthven, Kenneth; Hennessy, Sara
2002-01-01
Analyzes the pedagogical ideas underpinning teachers' accounts of the successful use of computer-based tools and resources to support the teaching and learning of mathematics. Organizes central themes to form a pedagogical model capable of informing the use of such technologies in classroom teaching and generating theoretical conjectures for…
Tandiseru, Selvi Rajuaty
2015-01-01
The problem in this research is the lack of creative thinking skills of students. One of the learning models that is expected to enhance student's creative thinking skill is the local culture-based mathematical heuristic-KR learning model (LC-BMHLM). Heuristic-KR is a learning model which was introduced by Krulik and Rudnick (1995) that is the…
Kartashev, Alexander; Safonov, Evgeniy; Kartasheva, Marina
2011-01-01
The mathematical model describing the operation of the installation of selfcontained heating and hot water supply based on solar thermal collector with the system of accumulation of heat energy, monitoring and control of thermal conditions of building is developed. Modeling of operation of the installation in different conditions is realized.
Medical Service
2002-01-01
It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546
Directory of Open Access Journals (Sweden)
Loyko V. I.
2015-06-01
Full Text Available Agricultural producers interested in marketing of raw materials, whereas processing companies are interested in the establishment of raw material zones, providing capacity utilization; therefore, the establishment of sustainable linkages between producers and processors of raw materials is an objective necessity. In the article, with the help of mathematical methods we examine the conditions of mutually beneficial economic relations between agricultural producers and processing enterprises. Mathematical model for estimating the profits of the company is built of the following conditions: producers sell processing plants raw materials, determined by the coefficient of the interest in the partnership at an agreed purchase price, and the remaining raw materials are processed, so they can sell their products independently. Profit of the processing plant is determined by the mathematical model. To describe the nonlinear market-based sales of goods from its retail price we used a hyperbolic demand function
Dielectric Relaxation of Lanthanide-Based Ternary Oxides: Physical and Mathematical Models
Directory of Open Access Journals (Sweden)
Chun Zhao
2012-01-01
Full Text Available Cerium-doped hafnium oxides (CexHf1−xO2 and lanthanum-doped zirconium oxides (LaxZr1−xO2 were investigated. The highest dielectric constants, k, were obtained from lightly doped oxides with an La content of x=0.09 and a Ce content of x=0.1, for which k-values of 33~40 were obtained. The dielectric relaxation appears to be related to the size of crystal grains formed during annealing, which was dependent on the doping level. The physical and mathematical models were used to analyze the relationship between k-values and frequencies. The variations in the k-values up to megahertz frequencies for both CexHf1−xO2 and LaxZr1−xO2 are simulated based on the Curie-von Schweidler (CS or Havriliak-Negami (HN relationships. Concerning the lightly doped CexHf1−xO2 and LaxZr1−xO2, the data extracted are best modeled by the HN law, while LaxZr1−xO2 with doping level from x=0.22 to 0.63 are best modelled based on the CS law.
A mathematical analysis of the selective enrichment of NECEEM-based non-SELEX.
Yu, Xinliang; Yu, Yixiong
2014-08-01
Non-Systematic Evolution of Ligands by EXponential enrichment (SELEX)selection of aptamers, a novel technology for aptamer selection from libraries of random DNA (or RNA) sequences, involves repetitive steps of partitioning without polymerase chain reaction (PCR) amplification between them. This selection is based on non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) and has exceptionally high efficiency. In this paper, a mathematical analysis was carried out to predict the levels of enrichment of non-SELEX selection under different conditions such as different protein concentrations and different efficiencies of partitioning. Investigated results suggest that the magnitude of the bulk affinity (k d) being 10(4) or 10(5) μM for the initial pool has no obvious effect on selective enrichment and that the first, second, and third rounds of non-SELEX selection have different optimum protein concentration values [T f] that give maximum enrichment levels when [T f] ranges from 0.0005 to 0.5 μM. The significance of analyzing selective enrichment of NECEEM-based non-SELEX with the efficiency of partitioning target-bound ligands from free ligands has been demonstrated.
Causality, mathematical models and statistical association: dismantling evidence-based medicine.
Thompson, R Paul
2010-04-01
From humble beginnings, largely at the medical school at McMaster University, Canada, the evidence-based medicine (EBM) movement has enjoyed a spectacular rise in international acceptance over the last 25 years. Randomized controlled trials (RCTs) and systematic reviews based on them have pride of place (the gold standard) in EBM's hierarchy of evidence; models and theories are relegated to the bottom of the hierarchy. In the last decade, RCTs have been extensively criticized. I briefly rehearse those criticisms because they are an important backdrop to the criticism of EBM developed in this paper. In essence, the argument developed here is that RCTs use mathematics solely as a tool of analysis rather than as the language of the science and that this fundamentally affects the validity of causal claims. As EBM gives pride of place to RCTs and devalues theoretical models - a devaluation that would be incomprehensible to a physicist or biologist - the validity of EBM's causal claims and knowledge claims are weak and far from a 'gold standard'.
Institute of Scientific and Technical Information of China (English)
SHU Linsen; CAO Huajun; LI Xianchong; ZHANG Chenglong; LI Yuxia
2015-01-01
The current researches on the tooth surface mathematical equations and the theory of gearing malnly pay attention to the ordinary type worm gear set (e.g., ZN, ZA, or ZK). The research of forming mechanism and three-dimensional modeling method for the double pitch worm gear set is not enough. So there are some difficulties in mathematical model deducing and geometry modeling of double pitch ZN-type worm gear set based on generation mechanism. In order to establish the mathematical model and the precise geometric model of double pitch ZN-type worm gear set, the structural characteristics and generation mechanism of the double pitch ZN-type worm gear set are investigated. Mathematical model of the ZN-type worm gear set is derived based on its generation mechanism and the theory of gearing. According to the mathematical model of the worm gear set which has been developed, a geometry modeling method of the double pitch ZN-type worm and worm gear is presented. Furthermore, a geometrical precision calculate method is proposed to evaluate the geometrical quality of the double pitch worm gear set. As a result, the maximum error is less than 6´10–4 mm in magnitude, thus the model of the double pitch ZN-type worm gear set is avallable to meet the requirements of finite element analysis and engineering application. The derived mathematical model and the proposed geometrical modeling method are helpful to guiding the design, manufacture and contact analysis of the worm gear set.
Photonic crystal fiber based chloride chemical sensors for corrosion monitoring
Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar
2016-04-01
Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.
Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications
Li, Jing; Lu, Yijiang
2009-01-01
A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.
Chemical Abstracts Service approach to management of large data bases.
Huffenberger, M A; Wigington, R L
1975-02-01
When information handling is "the business," as it is at Chemical Abstract Service (CAS), the total organization must be involved in information management. Since 1967, when, as a result of long-range planning efforts, CAS adopted a "data-base approach" to management of both the processing system and the distribution of information files, CAS has been grappling with the problems of managing large collections of information in computer-based systems. This paper describes what has been done at CAS in the management of large files and what we see as necessary, as a result of our experience, to improve and complete the information management system that is the foundation of our production processes.
Zirconia-based solid state chemical gas sensors
Zhuiykov, S
2000-01-01
This paper presents an overview of chemical gas sensors, based on solid state technology, that are sensitive to environmental gases, such as O sub 2 , SO sub x , NO sub x , CO sub 2 and hydrocarbons. The paper is focussed on performance of electrochemical gas sensors that are based on zirconia as a solid electrolyte. The paper considers sensor structures and selection of electrode materials. Impact of interfaces on sensor performance is discussed. This paper also provides a brief overview of electrochemical properties of zirconia and their effect on sensor performance. Impact of auxiliary materials on sensors performance characteristics, such as sensitivity, selectivity, response time and recovery time, is also discussed. Dual gas sensors that can be applied for simultaneous monitoring of the concentration of both oxygen and other gas phase components, are briefly considered
Wilfredo, Angulo
2014-01-01
We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.
Prospective Mathematics Teachers' Attitudes Towards Learning Mathematics with Technology
Ipek, A. Sabri; Berigel, Muhammed; Albayrak, Mustafa
2007-01-01
Role of technology which is an important tool for new approaches in learning mathematics is rapidly increasing at focus point of learning mathematics with new designs. One of the biggest factors at learning and instructing technology based mathematic education is attitudes of mathematics teachers towards technology. At this study, attitudes of…
Miller, Jason E; Walston, Timothy
2010-01-01
Inspired by BIO2010 and leveraging institutional and external funding, Truman State University built an undergraduate program in mathematical biology with high-quality, faculty-mentored interdisciplinary research experiences at its core. These experiences taught faculty and students to bridge the epistemological gap between the mathematical and life sciences. Together they created the infrastructure that currently supports several interdisciplinary courses, an innovative minor degree, and long-term interdepartmental research collaborations. This article describes how the program was built with support from the National Science Foundation's Interdisciplinary Training for Undergraduates in Biology and Mathematics program, and it shares lessons learned that will help other undergraduate institutions build their own program.
Graphene-Based Chemical Vapor Sensors for Electronic Nose Applications
Nallon, Eric C.
chemiresistor device and used as a chemical sensor, where its resistance is temporarily modified while exposed to chemical compounds. The inherent, broad selective nature of graphene is demonstrated by testing a sensor against a diverse set of volatile organic compounds and also against a set of chemically similar compounds. The sensor exhibits excellent selectivity and is capable of achieving high classification accuracies. The kinetics of the sensor's response are further investigated revealing a relationship between the transient behavior of the response curve and physiochemical properties of the compounds, such as the molar mass and vapor pressure. This kinetic information is also shown to provide important information for further pattern recognition and classification, which is demonstrated by increased classification accuracy of very similar compounds. Covalent modification of the graphene surface is demonstrated by means of plasma treatment and free radical exchange, and sensing performance compared to an unmodified graphene sensor. Finally, the first example of a graphene-based, cross-reactive chemical sensor array is demonstrated by applying various polymers as coatings over an array of graphene sensors. The sensor array is tested against a variety of compounds, including the complex odor of Scotch whiskies, where it is capable of perfect classification of 10 Scotch whiskey variations.
Mathematical points as didactical ideas
DEFF Research Database (Denmark)
Mogensen, Arne
2012-01-01
Mathematics teaching in Denmark was recently recommended better organized in sequences with clear mathematical pedagogical goals and a focus on mathematical points. In this paper I define a mathematical point and inform on coding of transcripts in a video based Danish research study on grade 8...
Directory of Open Access Journals (Sweden)
Tim Dunne
2012-10-01
Full Text Available The challenges inherent in assessing mathematical proficiency depend on a number of factors, amongst which are an explicit view of what constitutes mathematical proficiency, an understanding of how children learn and the purpose and function of teaching. All of these factors impact on the choice of approach to assessment. In this article we distinguish between two broad types of assessment, classroom-based and systemic assessment. We argue that the process of assessment informed by Rasch measurement theory (RMT can potentially support the demands of both classroom-based and systemic assessment, particularly if a developmental approach to learning is adopted, and an underlying model of developing mathematical proficiency is explicit in the assessment instruments and their supporting material. An example of a mathematics instrument and its analysis which illustrates this approach, is presented. We note that the role of assessment in the 21st century is potentially powerful. This influential role can only be justified if the assessments are of high quality and can be selected to match suitable moments in learning progress and the teaching process. Users of assessment data must have sufficient knowledge and insight to interpret the resulting numbers validly, and have sufficient discernment to make considered educational inferences from the data for teaching and learning responses.
Mathematical model for abrasive suspension jet cutting based on orthogonal test design
Institute of Scientific and Technical Information of China (English)
HU Gui-hua; ZHU Wen-hua; CAI Hong-xia; XU Chong; BAI Yu-jie; CHENG Jun; YUAN Jin; YU Tao
2009-01-01
This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet (AS J) cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerf ratio of the bottom width to the top width can be determined. In 'addition, the analysis of ranges and variances are all employed to identify various factors: traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. Furthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerf ratio. Finally, the verification experiments of cutting parameters' effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ.
Chronology of DIC technique based on the fundamental mathematical modeling and dehydration impact.
Alias, Norma; Saipol, Hafizah Farhah Saipan; Ghani, Asnida Che Abd
2014-12-01
A chronology of mathematical models for heat and mass transfer equation is proposed for the prediction of moisture and temperature behavior during drying using DIC (Détente Instantanée Contrôlée) or instant controlled pressure drop technique. DIC technique has the potential as most commonly used dehydration method for high impact food value including the nutrition maintenance and the best possible quality for food storage. The model is governed by the regression model, followed by 2D Fick's and Fourier's parabolic equation and 2D elliptic-parabolic equation in a rectangular slice. The models neglect the effect of shrinkage and radiation effects. The simulations of heat and mass transfer equations with parabolic and elliptic-parabolic types through some numerical methods based on finite difference method (FDM) have been illustrated. Intel®Core™2Duo processors with Linux operating system and C programming language have been considered as a computational platform for the simulation. Qualitative and quantitative differences between DIC technique and the conventional drying methods have been shown as a comparative.
Study of the Video Monitoring System Image Recognition Solutions Based on Mathematic models
Directory of Open Access Journals (Sweden)
Peilong Xu
2013-01-01
Full Text Available objective: Through establishment a set of image recognition system based on mathematic models, to develop a auto alarm solution for the video monitoring system. Methods: compare the images the video monitoring system collected according to the time sequences. Then after binaryzation and wave filtering, the images were converted into numerical values using autocorrelation function, and the alarm threshold value was confirmed by experiences. Results: Through experiments, the change ratios of the two images before and after image processing were inversely proportional to the autocorrelation function. When the function value is less than 0.8, it indicates that there is an object volumes larger than 1m3 has invaded into 15m distances, and when the function value is less than 0.6, it indicates that there is an object volumes larger than 1m3 has invaded into 30m distances. Conclusion: Through calculation of autocorrelation functions, auto alarm for the images collected by video monitoring system could be effectively realized.
Driessche, Pauline; Wu, Jianhong
2008-01-01
Based on lecture notes of two summer schools with a mixed audience from mathematical sciences, epidemiology and public health, this volume offers a comprehensive introduction to basic ideas and techniques in modeling infectious diseases, for the comparison of strategies to plan for an anticipated epidemic or pandemic, and to deal with a disease outbreak in real time. It covers detailed case studies for diseases including pandemic influenza, West Nile virus, and childhood diseases. Models for other diseases including Severe Acute Respiratory Syndrome, fox rabies, and sexually transmitted infections are included as applications. Its chapters are coherent and complementary independent units. In order to accustom students to look at the current literature and to experience different perspectives, no attempt has been made to achieve united writing style or unified notation. Notes on some mathematical background (calculus, matrix algebra, differential equations, and probability) have been prepared and may be downlo...
Vula, Eda; Kingji-Kastrati , Jeta; Podvorica, Fitore
2015-01-01
International audience; This study analyses the presentation of fractions in Kosovar and Albanian mathematics textbooks designed for students of one to fifth-grade. Physical characteristics of the selected textbooks, the presentation of fractions and the nature of the problems were analysed as well. Findings showed that Albanian mathematics textbooks covered more lessons on fractions than Kosovar textbooks. Textbooks from both countries focus mostly on part whole and operator construction. Al...
Modeling release of chemicals from multilayer materials into food
Directory of Open Access Journals (Sweden)
Huang Xiu-Ling
2016-01-01
Full Text Available The migration of chemicals from materials into food is predictable by various mathematical models. In this article, a general mathematical model is developed to quantify the release of chemicals through multilayer packaging films based on Fick's diffusion. The model is solved numerically to elucidate the effects of different diffusivity values of different layers, distribution of chemical between two adjacent layers and between material and food, mass transfer at the interface of material and food on the migration process.
Yuce, Kutluay; Adelman, Saul J.
2016-07-01
The middle B to the early F main sequence stars are thought to have some of the most quiet atmospheres. In this part of the HR diagram we find stars with atmospheres in radiative equilibrium. They lack the convective circulations of the middle F and cooler stars and the massive stellar winds of hotter stars. Diffusion theory requires the Chemically Peculiar stars to have relatively quiet atmospheres and if there are no magnetic fields they should lack abundance spots. If we look at stars evolving off the Main Sequence in this part of the HR diagram, we see that the evolutionary paths of stars of different mass do not cross. So if we compare stars with the same effective temperature and surface gravity, we are studying stars of the same luminosity and mass. By comparing their elemental abundances, we might be able to identify physical processes which cause their abundances to be different. In this work we begin with stars whose effective temperatures and surface gravities are similar, and which has been analyzed by us using spectra obtained from the Dominion Astrophysical Observatory.
Mathematical Footprints Discovering Mathematics Everywhere
Pappas, Theoni
1999-01-01
MATHEMATICAL FOOTPRINTS takes a creative look at the role mathematics has played since prehistoric times, and will play in the future, and uncovers mathematics where you least expect to find it from its many uses in medicine, the sciences, and its appearance in art to its patterns in nature and its central role in the development of computers. Pappas presents mathematical ideas in a readable non-threatening manner. MATHEMATICAL FOOTPRINTS is another gem by the creator of THE MATHEMATICS CALENDAR and author of THE JOY OF MATHEMATICS. "Pappas's books have been gold mines of mathematical ent
Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction
Directory of Open Access Journals (Sweden)
Aleksandar Sabljic
2004-12-01
Full Text Available This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.
Trends in information theory-based chemical structure codification.
Barigye, Stephen J; Marrero-Ponce, Yovani; Pérez-Giménez, Facundo; Bonchev, Danail
2014-08-01
This report offers a chronological review of the most relevant applications of information theory in the codification of chemical structure information, through the so-called information indices. Basically, these are derived from the analysis of the statistical patterns of molecular structure representations, which include primitive global chemical formulae, chemical graphs, or matrix representations. Finally, new approaches that attempt to go "back to the roots" of information theory, in order to integrate other information-theoretic measures in chemical structure coding are discussed.
Leifer, M S
2015-01-01
In this essay, I argue that mathematics is a natural science---just like physics, chemistry, or biology---and that this can explain the alleged "unreasonable" effectiveness of mathematics in the physical sciences. The main challenge for this view is to explain how mathematical theories can become increasingly abstract and develop their own internal structure, whilst still maintaining an appropriate empirical tether that can explain their later use in physics. In order to address this, I offer a theory of mathematical theory-building based on the idea that human knowledge has the structure of a scale-free network and that abstract mathematical theories arise from a repeated process of replacing strong analogies with new hubs in this network. This allows mathematics to be seen as the study of regularities, within regularities, within ..., within regularities of the natural world. Since mathematical theories are derived from the natural world, albeit at a much higher level of abstraction than most other scientif...
Post secondary project-based learning in science, technology, engineering and mathematics
Directory of Open Access Journals (Sweden)
Rachel A Ralph
2016-03-01
Full Text Available Project-based learning (PjBL - to distinguish from problem-based learning - PBL has become a recurrent practice in K-12 classroom environments. As PjBL has become prominent in K-12 classrooms, it has also surfaced in post-secondary institutions. The purpose of this paper is to examine the research that has studied a variety of science, technology, engineering and mathematic subjects using PjBL in post-secondary classrooms. Eleven articles (including qualitative, quantitative and mixed methods were included. The format includes: an introduction and background (which defines PjBL and STEM, research methods, quality appraisal used, results, and a discussion, future research and a conclusion. Two tables and two figures are included. In this paper, theoretical backgrounds and key terms were identified, followed by a literature review discussing four themes: content knowledge, interdisciplinary skills, collaboration and skill development for future education and careers. Results suggested that there is a positive connection between content knowledge learning and PjBL in collaborative settings. Additionally, some negative perceptions arose regarding teamwork situations. Interdisciplinary skills were achieved, but quite limited in post-secondary classrooms. PjBL and STEM were perceived to be important for future education and careers. Future research needs to be completed and institutional curriculum changes informed by the results of this research need to occur to further explore interdisciplinary courses and the use of PjBL.
Study of Aerosol Chemical Composition Based on Aerosol Optical Properties
Berry, Austin; Aryal, Rudra
2015-03-01
We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.
Development of Oilfield Chemicals Based on Advantages in Petrochemical Feedstocks
Institute of Scientific and Technical Information of China (English)
Wang Xieqing; Peng Pu
2002-01-01
This article focuses on the routes for development of oilfield chemicals by making use of the feedstock advantages of the petrochemical industry. The diversification of oilfield chemicals has re sulted in thousand product grades. Because there are hundred domestic producers of oilfield chemicals,mostly medium and small producers, the fluctuations of feedstock prices and product quality cannot be conducive to the application and development of oilfield chemicals. This article illustrates the feasibility of oilfield chemical production by state-run medium and large petrochemical enterprises by allowing full play to their own advantages in petrochemical feedstocks.
Energy Technology Data Exchange (ETDEWEB)
Tachimori, Shoichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kitamura, Tatsuaki
1996-10-01
A computer code REACT-Mod which simulates various chemical reactions in an aqueous nitric acid solution involving uranium, plutonium, neptunium, technetium etc. e.g., redox, radiolytic and disproportionation reactions of 68, was developed based on the kinetics model. The numerical solution method adopted in the code are two, a kinetics model totally based on the rate law of which differential equations are solved by the modified Porsing method, and a two-step model based on both the rate law and equilibrium law. Only the former treats 27 radiolytic reactions. The latter is beneficially used to have a quick and approximate result by economical computation. The present report aims not only to explain the concept, chemical reactions treated and characteristics of the model but also to provide details of the program for users of the REACT-Mod code. (author)
Barriteau Phaire, Candace
2013-01-01
The teaching and learning of mathematics has been the subject of debate for over 30 years and the most recent reform efforts are in response to concerns regarding the mathematical competence of students in the United States (Ball, Hill, & Bass, 2005; Battista, 1994; Cavanagh, 2008). Standards-based Instructional Materials (SBIM) allows…
Yuliani, Kiki; Saragih, Sahat
2015-01-01
The purpose of this research was to: 1) development of learning devices based guided discovery model in improving of understanding concept and critical thinking mathematically ability of students at Islamic Junior High School; 2) describe improvement understanding concept and critical thinking mathematically ability of students at MTs by using…
Calhoon, Mary Beth
2008-01-01
The purpose of this article is to explore the research and developmental needs for curriculum-based measurement (CBM) at the secondary level (9th through 12th grades) for mathematics. Much has been accomplished empirically on the validity, reliability, and utility of CBM as an assessment measure in mathematics at the elementary level.…
Jitendra, Asha K.; Dupuis, Danielle N.; Star, Jon R.; Rodriguez, Michael C.
2016-01-01
This study examined the effect of schema-based instruction (SBI) on the proportional problem-solving performance of students with mathematics difficulties only (MD) and students with mathematics and reading difficulties (MDRD). Specifically, we examined the responsiveness of 260 seventh grade students identified as MD or MDRD to a 6-week treatment…
Martinez, Mara Vanina; Superfine, Alison Castro; Carlton, Theresa; Dasgupta, Chandan
2015-01-01
This paper focuses on results from a study conducted with two cohorts of pre-service teachers (PSTs) in a video case-based mathematics methods course at a large Midwestern university in the US. The motivation for this study was to look beyond whether or not PSTs pay attention to mathematical thinking of students, as shown by previous studies when…
Finite mathematics models and applications
Morris, Carla C
2015-01-01
Features step-by-step examples based on actual data and connects fundamental mathematical modeling skills and decision making concepts to everyday applicability Featuring key linear programming, matrix, and probability concepts, Finite Mathematics: Models and Applications emphasizes cross-disciplinary applications that relate mathematics to everyday life. The book provides a unique combination of practical mathematical applications to illustrate the wide use of mathematics in fields ranging from business, economics, finance, management, operations research, and the life and social sciences.
Wright, Vince
2014-03-01
Pirie and Kieren (1989 For the learning of mathematics, 9(3)7-11, 1992 Journal of Mathematical Behavior, 11, 243-257, 1994a Educational Studies in Mathematics, 26, 61-86, 1994b For the Learning of Mathematics, 14(1)39-43) created a model (P-K) that describes a dynamic and recursive process by which learners develop their mathematical understanding. The model was adapted to create the teaching model used in the New Zealand Numeracy Development Projects (Ministry of Education, 2007). A case study of a 3-week sequence of instruction with a group of eight 12- and 13-year-old students provided the data. The teacher/researcher used folding back to materials and images and progressing from materials to imaging to number properties to assist students to develop their understanding of frequencies as proportions. The data show that successful implementation of the model is dependent on the teacher noticing and responding to the layers of understanding demonstrated by the students and the careful selection of materials, problems and situations. It supports the use of the model as a useful part of teachers' instructional strategies and the importance of pedagogical content knowledge to the quality of the way the model is used.
Han, Jinxiang; Huang, Jinzhao
2012-03-01
In this study, based on the resonator model and exciplex model of electromagnetic radiation within the human body, mathematical model of biological order state, also referred to as syndrome in traditional Chinese medicine, was established and expressed as: "Sy = v/ 1n(6I + 1)". This model provides the theoretical foundation for experimental research addressing the order state of living system, especially the quantitative research syndrome in traditional Chinese medicine.
Directory of Open Access Journals (Sweden)
Dinh An Nguyen
2012-07-01
Full Text Available Many of the Proton Exchange Membrane Fuel Cell (PEMFC models proposed in the literature consist of mathematical equations. However, they are not adequately practical for simulating power systems. The proposed model takes into account phenomena such as activation polarization, ohmic polarization, double layer capacitance and mass transport effects present in a PEM fuel cell. Using electrical analogies and a mathematical modeling of PEMFC, the circuit model is established. To evaluate the effectiveness of the circuit model, its static and dynamic performances under load step changes are simulated and compared to the numerical results obtained by solving the mathematical model. Finally, the applicability of our model is demonstrated by simulating a practical system.
Zulfaneti, Rismen, Sefna; Suryani, Mulia
2016-02-01
The previous research showed that the teachers of the fourth grade at elementary school in West Sumatra need lesson plan and teaching materials which integrated with character education especially on mathematics subject. Teachers need teaching materials which encompasses the daily life problems (contextual) so that, it can increase students' understanding of mathematics. Realistic mathematics education is a solution to these problems. The aims of the research are to develop learning equipment, i. e lesson plan sand valid worksheets. Development model referred to the Plomp development model which consists of three phase namely preliminary research, prototyping phase, and assessment phase. However, in this research, it is only presented the results in the expert review which is in the part of prototyping phase. The instrument was the validation worksheet. Expert stated that each of lesson plan and students' worksheet were in valid criterion
Directory of Open Access Journals (Sweden)
Blaženka Divjak
2011-06-01
Full Text Available Normal 0 21 false false false SH X-NONE X-NONE Information technologies are an integral part of a contemporary society which bases its progress on knowledge being one goal of education. Beside acquiring knowledge, skills and routines, the goal of education is to create a complete individual who can rationally and timely make decisions, purposefully react in new situations and be trained for life-long learning. In order to accomplish all this, it is necessary to make educational process more creative, contemporary and adjusted to new generations of computer literate pupils who demand quicker and more frequent interactions, a lot of information at the same time, generations who quickly acquire rules of computer games. Computer games meeting pedagogical criteria should become an integral part of learning. Teaching with mathematical computer games, which fulfil pedagogical criteria, influences pupils’ motivation, learning, retention and forgetting. This paper provides a review of literature in this field and determines whether the use of mathematical computer games contributes to more efficient realisation of educational goals at all level of education. Furthermore, considering prior research we have attempted to establish whether the use of mathematical games for teaching has an impact on the formation of a positive attitude of pupils of different ages toward the subject of mathematics, their motivation and knowledge acquisition when compared to learning without computer games. Finally, we have analysed different research methods concerning this issue and assessed the impact of pedagogically designed mathematical computer games on the realisation of educational goals and quality improvement of teaching and learning.
Graphene Electronic Device Based Biosensors and Chemical Sensors
Jiang, Shan
Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their
Andreescu, Titu; Tetiva, Marian
2017-01-01
Building bridges between classical results and contemporary nonstandard problems, Mathematical Bridges embraces important topics in analysis and algebra from a problem-solving perspective. Blending old and new techniques, tactics and strategies used in solving challenging mathematical problems, readers will discover numerous genuine mathematical gems throughout that will heighten their appreciation of the inherent beauty of mathematics. Most of the problems are original to the authors and are intertwined in a well-motivated exposition driven by representative examples. The book is structured to assist the reader in formulating and proving conjectures, as well as devising solutions to important mathematical problems by making connections between various concepts and ideas from different areas of mathematics. Instructors and educators teaching problem-solving courses or organizing mathematics clubs, as well as motivated mathematics students from high school juniors to college seniors, will find Mathematical Bri...
Educating mathematics teacher educators
DEFF Research Database (Denmark)
Højgaard, Tomas; Jankvist, Uffe Thomas
2014-01-01
The paper argues for a three-dimensional course design structure for future mathematics teacher educators. More precisely we describe the design and implementation of a course basing itself on: the two mathematical competencies of modelling and problem tackling, this being the first dimension......; the two mathematical topics of differential equations and stochastics, this being the second dimension; and finally a third dimension the purpose of which is to deepen the two others by means of a didactical perspective....
Jackson, Karen Latrice Terrell
2014-01-01
Students' perceptions influence their expectations and values. According to Expectations and Values Theory of Achievement Motivation (EVT-AM), students' expectations and values impact their behaviors (Eccles & Wigfield, 2002). This study seeks to find students' perceptions of developmental mathematics in a mastery learning computer-based…
Stevens, Olinger; Leigh, Erika
2012-01-01
Scope and Method of Study: The purpose of the study is to use an empirical approach to identify a simple, economical, efficient, and technically adequate performance measure that teachers can use to assess student growth in mathematics. The current study has been designed to expand the body of research for math CBM to further examine technical…
Does Inquiry Based Learning Affect Students' Beliefs and Attitudes towards Mathematics?
McGregor, Darren
2014-01-01
Ill-structured tasks presented in an inquiry learning environment have the potential to affect students' beliefs and attitudes towards mathematics. This empirical research followed a Design Experiment approach to explore how aspects of using ill-structured tasks may have affected students' beliefs and attitudes. Results showed this task type and…
Design of discrete-time cellular neural networks based on mathematical morphology
terBrugge, MH; Nijhuis, JAG; Spaanenburg, L
1996-01-01
Mathematical morphology is a discipline that provides a formal framework for the analysis and manipulation of images. Its theoretical foundations have been well-established in the last forty years and it has shown to be a powerful tool in the development of a large number of image processing applica
Context-based mathematics tasks in Indonesia : Toward better practice and achievement
Wijaya, A.
2015-01-01
The Indonesian national curriculum mandates that mathematics education must be relevant to the needs of life and should offer students opportunities to develop the ability to apply their knowledge in society. Furthermore, there are educational movements in Indonesia that promote the application of m
Embedding Game-Based Problem-Solving Phase into Problem-Posing System for Mathematics Learning
Chang, Kuo-En; Wu, Lin-Jung; Weng, Sheng-En; Sung, Yao-Ting
2012-01-01
A problem-posing system is developed with four phases including posing problem, planning, solving problem, and looking back, in which the "solving problem" phase is implemented by game-scenarios. The system supports elementary students in the process of problem-posing, allowing them to fully engage in mathematical activities. In total, 92 fifth…
Digital assessment-driven examples-based mathematics for computer science students
Heck, A.; Brouwer, N.; Amado, N.; Carreira, S.
2015-01-01
nnovation, inclusion, sharing and diversity are some of the words that briefly and suitably characterize the ICTMT series of biennial international conferences - the International Conference on Technology in Mathematics Teaching. Being the twelfth of a series which began in Birmingham, UK, in 1993,
Scaling a Technology-Based Innovation: Windows on the Evolution of Mathematics Teachers' Practices
Clark-Wilson, A.; Hoyles, C.; Noss, R.; Vahey, P.; Roschelle, J.
2015-01-01
This paper reports research on effects on teachers' classroom practices resulting from their engagement in sustained professional development and classroom teaching of a resource that embeds carefully designed dynamic technology within middle school mathematics (11-14 years). The research investigated the self-reported evolution of teachers'…
Thanheiser, Eva; Browning, Christine; Edson, Alden J.; Kastberg, Signe; Lo, Jane-Jane
2013-01-01
This survey of the literature summarizes and reflects on research findings regarding elementary preservice teachers' (PSTs') mathematics conceptions and the development thereof. Despite the current focus on teacher education, peer-reviewed journals offer a surprisingly sparse insight in these areas. The limited research that exists…
Designing and Incorporating Mathematics-Based Video Cases Highlighting Virtual and Physical Tool Use
Kurz, Terri L.; Kokic, Ivana Batarelo
2012-01-01
As there has recently been an onslaught of video cases being developed and implemented with preservice teachers, it is important to evaluate how we should use these cases. This research investigates the features elementary preservice teachers consider valuable when using video cases in mathematics education. The researchers used hierarchical…
Porosity prediction of calcium phosphate cements based on chemical composition.
Öhman, Caroline; Unosson, Johanna; Carlsson, Elin; Ginebra, Maria Pau; Persson, Cecilia; Engqvist, Håkan
2015-07-01
The porosity of calcium phosphate cements has an impact on several important parameters, such as strength, resorbability and bioactivity. A model to predict the porosity for biomedical cements would hence be a useful tool. At the moment such a model only exists for Portland cements. The aim of this study was to develop and validate a first porosity prediction model for calcium phosphate cements. On the basis of chemical reaction, molar weight and density of components, a volume-based model was developed and validated using calcium phosphate cement as model material. 60 mol% β-tricalcium phosphate and 40 mol% monocalcium phosphate monohydrate were mixed with deionized water, at different liquid-to-powder ratios. Samples were set for 24 h at 37°C and 100% relative humidity. Thereafter, samples were dried either under vacuum at room temperature for 24 h or in air at 37 °C for 7 days. Porosity and phase composition were determined. It was found that the two drying protocols led to the formation of brushite and monetite, respectively. The model was found to predict well the experimental values and also data reported in the literature for apatite cements, as deduced from the small absolute average residual errors (brushite, monetite and apatite cements. The model gives a good estimate of the final porosity and has the potential to be used as a porosity prediction tool in the biomedical cement field.
Reference field effect transistor based on chemically modified ISFETs
Skowronska-Ptasinska, Maria; Wal, van der Peter D.; Berg, van den Albert; Bergveld, Piet; Sudhölter, Ernst J.R.; Reinhoudt, David N.
1990-01-01
Different hydrophobic polymers were used for chemical modification of ion-sensitive field effect transistors (ISFETs) in order to prepare a reference FET (REFET). Chemical attachment of the polymer to the ISFET gate results in a long lifetime of the device. Properties of polyacrylate (polyACE) REFET
Fielding-Wells, Jill; O'Brien, Mia; Makar, Katie
2017-03-01
Inquiry-based learning (IBL) is a pedagogical approach in which students address complex, ill-structured problems set in authentic contexts. While IBL is gaining ground in Australia as an instructional practice, there has been little research that considers implications for student motivation and engagement. Expectancy-value theory (Eccles and Wigfield 2002) provides a framework through which children's beliefs about their mathematical competency and their expectation of success are able to be examined and interpreted, alongside students' perceptions of task value. In this paper, Eccles and Wigfield's expectancy-value model has been adopted as a lens to examine a complete unit of mathematical inquiry as undertaken with a class of 9-10-year-old students. Data were sourced from a unit (˜10 lessons) based on geometry and geometrical reasoning. The units were videotaped in full, transcribed, and along with field notes and student work samples, subjected to theoretical coding using the dimensions of Eccles and Wigfield's model. The findings provide insight into aspects of IBL that may impact student motivation and engagement. The study is limited to a single unit; however, the results provide a depth of insight into IBL in practice while identifying features of IBL that may be instrumental in bringing about increased motivation and engagement of students in mathematics. Identifying potentially motivating aspects of IBL enable these to be integrated and more closely studied in IBL practises.
Extraction of Web Mathematical Formulas Based on Nutch%基于Nutch的Web数学公式提取
Institute of Scientific and Technical Information of China (English)
崔林卫; 苏伟; 郭卫; 李廉
2011-01-01
The paper introduces the recognizing and extracting methods of mathematics expressions in formula-based mathematics search engine. It summarizes the corresponding features of MathML,OpenMath, LaTex and Infix when they are embedded in a Web page. A feature-based heuristic method of recognizing and extracting mathematical expressions is given in the paper. The experiments proves that the method is effective and useful.%本文主要研究基于公式的数学搜索引擎中数学公式的识别和提取方法,总结了MathML、Open-Math、LaTex、Infix格式数学公式在网页中出现时的各自特征,提出了基于特征和启发式规则的公式识别和提取方法,并用实验说明了该识别和提取方法的可行性和准确率.
Directory of Open Access Journals (Sweden)
Kurz, Terri L.
2011-05-01
Full Text Available Technological tools available on the Internet can be used to support teachers’ understanding of how to teach mathematics to their students. This paper outlines a method for using algebraic tools in mathematics with teachers to help them discover features to facilitate student learning and understanding with the support of statistical software. The teachers first investigate algebraic tools and then analyze features of the tools and how they support or limit student learning. Personal Construct Theory (Kelly, 1955 is used to first help teachers create and self administer repertory grids and then generate dendrograms for cluster analysis. The model described can help others implement technology in a similar manner making use of both web-based applets and statistical software in an authentic context.
Grimm, Fabian A; Iwata, Yasuhiro; Sirenko, Oksana; Chappell, Grace A; Wright, Fred A; Reif, David M; Braisted, John; Gerhold, David L; Yeakley, Joanne M; Shepard, Peter; Seligmann, Bruce; Roy, Tim; Boogaard, Peter J; Ketelslegers, Hans B; Rohde, Arlean M; Rusyn, Ivan
2016-08-21
Comparative assessment of potential human health impacts is a critical step in evaluating both chemical alternatives and existing products on the market. Most alternatives assessments are conducted on a chemical-by-chemical basis and it is seldom acknowledged that humans are exposed to complex products, not individual substances. Indeed, substances of Unknown or Variable composition, Complex reaction products, and Biological materials (UVCBs) are ubiquitous in commerce yet they present a major challenge for registration and health assessments. Here, we present a comprehensive experimental and computational approach to categorize UVCBs according to global similarities in their bioactivity using a suite of in vitro models. We used petroleum substances, an important group of UVCBs which are grouped for regulatory approval and read-across primarily on physico-chemical properties and the manufacturing process, and only partially based on toxicity data, as a case study. We exposed induced pluripotent stem cell-derived cardiomyocytes and hepatocytes to DMSO-soluble extracts of 21 petroleum substances from five product groups. Concentration-response data from high-content imaging in cardiomyocytes and hepatocytes, as well as targeted high-throughput transcriptomic analysis of the hepatocytes, revealed distinct groups of petroleum substances. Data integration showed that bioactivity profiling affords clustering of petroleum substances in a manner similar to the manufacturing process-based categories. Moreover, we observed a high degree of correlation between bioactivity profiles and physico-chemical properties, as well as improved groupings when chemical and biological data were combined. Altogether, we demonstrate how novel in vitro screening approaches can be effectively utilized in combination with physico-chemical characteristics to group complex substances and enable read-across. This approach allows for rapid and scientifically-informed evaluation of health impacts of
Property Model-based Tailor-made Design of Chemical-based Products
DEFF Research Database (Denmark)
Kalakul, Sawitree
on experiment are reduced leading to faster and cheaper to market the products. The tools also help to manage the solution of product design problems, which usually require efficient handling of model-data-knowledge from different sources and at different time and size scales. The main contribution......Computer-aided model-based methods and tools are increasingly playing important roles in chemical product design. They have the potential to very quickly search for and identify reliable product candidates that can then be verified through experiments. Inthis way, the time and resources spent...... of this project is: (1) the development of a systematic model-based framework for chemical product design; (2) its implementation as a computer-aided tool based on a specially developed architecture; (3) the creation of product design template together with their algorithms, models, tools and data for various...
Mathematical modeling and computational intelligence in engineering applications
Silva Neto, Antônio José da; Silva, Geraldo Nunes
2016-01-01
This book brings together a rich selection of studies in mathematical modeling and computational intelligence, with application in several fields of engineering, like automation, biomedical, chemical, civil, electrical, electronic, geophysical and mechanical engineering, on a multidisciplinary approach. Authors from five countries and 16 different research centers contribute with their expertise in both the fundamentals and real problems applications based upon their strong background on modeling and computational intelligence. The reader will find a wide variety of applications, mathematical and computational tools and original results, all presented with rigorous mathematical procedures. This work is intended for use in graduate courses of engineering, applied mathematics and applied computation where tools as mathematical and computational modeling, numerical methods and computational intelligence are applied to the solution of real problems.
Plofker, Kim
2009-01-01
Based on extensive research in Sanskrit sources, Mathematics in India chronicles the development of mathematical techniques and texts in South Asia from antiquity to the early modern period. Kim Plofker reexamines the few facts about Indian mathematics that have become common knowledge--such as the Indian origin of Arabic numerals--and she sets them in a larger textual and cultural framework. The book details aspects of the subject that have been largely passed over in the past, including the relationships between Indian mathematics and astronomy, and their cross-fertilizations with Islamic sc
DEFF Research Database (Denmark)
Winsløw, Carl
2015-01-01
Mathematics is studied in universities by a large number of students. At the same time it is a field of research for a (smaller) number of university teachers. What relations, if any, exist between university research and teaching of mathematics? Can research “support” teaching? What research...... and what teaching? In this presentation we propose a theoretical framework to study these questions more precisely, based on the anthropological theory of didactics. As a main application, the links between the practices of mathematical research and university mathematics teaching are examined...
... this page: //medlineplus.gov/ency/article/001534.htm Mathematics disorder To use the sharing features on this page, please enable JavaScript. Mathematics disorder is a condition in which a child's ...
Kilpatrick, Jeremy
2014-01-01
This paper addresses the contested way that ethnomathematics has sometimes been received by mathematicians and others and what that disagreement might suggest about issues in mathematics education; namely, (a) the relation of ethnomathematics to academic mathematics; (b) recent efforts to reform secondary school mathematics so that it prepares…
Institute of Scientific and Technical Information of China (English)
牛立尚
2015-01-01
高职学生数学基础一般都比较薄弱，有些基本的数学概念、定义、定理等理解起来较为抽象，不易于牢固掌握，这使得高等数学的授课教学较难进行，本文将数学软件应用于教学中，创造性地建构了观察教学法、验证教学法与模拟教学法等教学方法，弥补了传统教学方法的不足，使得高职数学教学耳目一新，活跃了课堂授课氛围，进而改善了教学效果。%Vocational Students mathematical foundations are generally weak, some basic mathematical concepts, defini-tions, theorems, etc. to understand more abstract and difficult to firmly grasp, which makes teaching more difficult to carry out the teaching of advanced mathematics, this article will apply to the teaching of mathematics software, creative Construc-tion observed teaching, teaching and simulation verification pedagogy, teaching methods, to make up for the shortcomings of traditional teaching methods, so refreshing vocational mathematics teaching, active classroom atmosphere, thereby impro-ving the effectiveness of teaching.
Grizzle-Martin, Tamieka
2014-01-01
Children who struggle in mathematics may also lack cognitive awareness in mathematical problem solving. The cognitively-driven program IMPROVE, a multidimensional method for teaching mathematics, has been shown to be helpful for students with mathematical learning difficulties (MLD). Guided by cognitive theory, the purpose of this…
Teaching Mathematical Modelling.
Jones, Mark S.
1997-01-01
Outlines a course at the University of Glamorgan in the United Kingdom in which a computer algebra system (CAS) teaches mathematical modeling. The format is based on continual assessment of group and individual work stating the problem, a feature list, and formulation of the models. No additional mathematical word processing package is necessary.…
Business Mathematics Curriculum.
EASTCONN Regional Educational Services Center, North Windham, CT.
This curriculum guide for teaching business mathematics in the Connecticut Vocational-Technical School System is based on the latest thinking of instructors in the field, suggestions from mathematics authorities, and current instructional approaches in education. The curriculum guide consists of six sections: (1) career relationships and…
Mathematics Education in Argentina
Varsavsky, Cristina; Anaya, Marta
2009-01-01
This article gives an overview of the state of mathematics education in Argentina across all levels, in the regional and world contexts. Statistics are drawn from Mercosur and UNESCO data bases, World Education Indicators and various national time-series government reports. Mathematics results in national testing programmes, Programme for…
Teaching Mathematical Induction I.
Dubinsky, Ed
1986-01-01
A novel approach to teaching mathematical induction was used, based on a Piagetian theory of learning abstract mathematical concepts in which the learner uses reflective abstraction to construct new schemas out of old ones. Computer experiences are used to induce students to make the appropriate reflective abstractions. (MNS)
SOIL QUALITY ASSESSMENT BASED ON CHEMICAL, ENZYMATIC AND BACTERIOLOGICAL ANALYSIS
Directory of Open Access Journals (Sweden)
Sofia-Paulina BALAURE
2012-01-01
Full Text Available This study highlights the problem of soil pollution as the result of human activities. Soil pollutans may be either chemicals or biological in nature. microbial enzymatic activities are often proposed as indicators of environmental stress. The soil samples were submitted by chemical, microbiological and enzymatic analyses. Chemical analyses were been made for determinating the heavy metals. Heavy metals from the forest soil were represented by Cu, Zn, Mn, Ni, Pb, Cd and Cr. To evaluate the concentration in heavy metals from the filtrate, we used a acetylene-nitrous oxide flame atomic absorption spectrophotometry. Potential dehydrogenase activity, the only indicator of the possible sources of pollution, excluded the presence of either chemical or biological pollution. The number of bacteria involved in the biogeochemical cycle of nitrogen in the analyzed soil indicated a high efficiency regarding the mineralization of the organic residues of plant and animal origin.
Nanoscale chemical sensor based on organic thin-film transistors
Wang, Liang; Fine, Daniel; Dodabalapur, Ananth
2004-12-01
Nanoscale organic thin-film transistors were fabricated to investigate their chemical sensing properties. The use of a four-terminal geometry ensures that the sensor active area is truly nanoscale, and eliminates undesirable spreading currents. The sensor response was markedly different in nanoscale sensors compared to large-area sensors for the same analyte-semiconductor combination. The chemical sensing mechanisms in both microscale and nanoscale transistors are briefly discussed.
DEFF Research Database (Denmark)
Friesel, Anna
2013-01-01
This paper presents the contents and the teaching methods used in the fourth semester course - REG4E - an important subject in engineering, namely Control Theory and Dynamical Systems. Control Theory courses in engineering education are usually related to exercises in the laboratory or to projects....... However, in order to understand complexity of control systems, the students need to possess an analytical understanding of abstract mathematical problems. Our main goal is to illustrate the theory through the robot project, but at the same time we force our students to train their analytical skills...... by mandatory exercises including problems of abstract mathematics. This paper describes our effort to motivate students to work with the theory. We conclude with our and students' own opinion on their work during the semester. Ideas for future development of this course are presented....
Java Based Computer Algorithms for the Solution of a Business Mathematics Model
Directory of Open Access Journals (Sweden)
A. D. Chinedu
2014-10-01
Full Text Available A novel approach is proposed as a framework for working out uncertainties associated with decisions between the choices of leasing and procurement of capital assets in a manufacturing industry. The mathematical concept of the tool is discussed while the technique adopted is much simpler to implement and initialize. The codes were developed in Java-programming language and text-run and executed on a computer system running on Windows 7 operating system. This was done in order to solve a model that illustrates a case study in actuarial mathematics. Meanwhile the solution obtained proves to be stable and proffers to suit the growing frenzy for software for similar recurring cases in business. In addition, it speeds up the computational results. The results obtained using the empirical method is compared with the output and adjudged excellent in terms of accuracy and adoption.
Yilmaz, Suha; Tekin-Dede, Ayse
2016-01-01
Mathematization competency is considered in the field as the focus of modelling process. Considering the various definitions, the components of the mathematization competency are determined as identifying assumptions, identifying variables based on the assumptions and constructing mathematical model/s based on the relations among identified…
Nasini, Stefano
2015-01-01
The thesis deals with the theoretical and practical study of mathematical programming methodologies to the analysis complex networks and their application in economic and social problems. More specifically, it applies models and methods for solving linear and integer programming problems to network models exploiting the matrix structure of such models, resulting in efficient computational procedures and small processing time. As a consequence, it allows the study of larger and more complex n...
Directory of Open Access Journals (Sweden)
Salar Faramarzi
2014-04-01
Full Text Available Target: With advances in cognitive neuroscience and the developing connection between neuroscience and education in recent years, new windows has been opened in the realm of teaching and learning for the education experts. So education has vastly benefited from the results of researches in neuroscience to improve learning. The study strived to investigate the effectiveness of “brain based teaching” on the executive functions of the students with mathematics learning disability in Isfahan city. Method: To this end, three students with mathematical learning disability were selected using purposeful sampling. In this investing used a single subject with A-B design. Intervention was started after determining the base-line. The “brain based teaching” package was taught to each single participant for 26 intervention sessions. And 1 month after the intervention period follow-up test was performed. The instruments used, included, Raven intelligence test, The Iran key math diagnostic arithmetic and Conner’s questionnaire neuropsychological. The gathered data was analyzed using descriptive statistics and visual analysis. Results: Based on that, Results revealed that during the visual analysis of data graphs for executive function deficits, the study intervention was significantly effective for all 3 participants. Conclusions: This study showed that brain based teaching improves the executive functions of the students and thus, could be used in educating children with learning disabilities.
Directory of Open Access Journals (Sweden)
Cita Dwi Rosita
2016-10-01
Full Text Available Courseware have an important role in the achievement of the objectives of education. Nevertheless, it does not mean any learning resources can be used for a type of learning. The teacher should provide and develop materials appropriate to the characteristics and the social environment of its student. Number Theory courses is one of the basic subjects that would be a prerequisite for courses at the next level, such as Linear Algebra, Complex Analysis, Real Analysis, Transformation Geometry, and Algebra Structure. Thus, the student’s understanding about the essential concepts that exist in this course will determine their success in studying subjects that mentioned above. In trying to understand most of the topics in Number Theory required the abilities of mathematical argumentation and representation. The ability of argumentation is required in studying the topic of complex number system, special operations, mathematical induction, congruence and divisibility. Ability representation especially verbal representations and symbols required by almost all the topics in this course. The purpose of this paper is to describe the development of teaching and learning Number Theory materials which facilitate students to develop the ability of mathematical argumentation and representation. The model used is a Thiagarajan development model consisting phases of defining, planning, development, and deployment. This paper is restricted to the analysis of the results of the materials validation from number theory experts.
Institute of Scientific and Technical Information of China (English)
陆源
2013-01-01
本文首先论述了数学实践的必要性，并以此为据点，说明了在生活中培养学生对数学的热爱的重要性，进而阐述了以数学实践为依托下的高校数学教学方法，希望给予同行以借鉴。%This paper first discusses the necessity of math practice, and as a base, illustrates the importance of cultivating students' love for mathematics in life, and then elaborates the university mathematics teaching method to rely on mathematical practice, hoping to give reference.
Yeh, Chin-yah
2013-01-01
Structures of chemical compounds can be synthesized and categorized through mathematical means. Organic compounds are suitable targets because of their simple valences. Acyclic organic compounds made of hydrogen and second-row elements C, N, O, and F are presented as an example. In five categories of organic compounds, chemical structures can be generated exclusively and exhaustively using ab initio methods. It is shown that mathematical variables can serve as chemical symbols and mathematical equations are chemical structure generators.
DEFF Research Database (Denmark)
Blomhøj, Morten
2004-01-01
Developing competences for setting up, analysing and criticising mathematical models are normally seen as relevant only from and above upper secondary level. The general belief among teachers is that modelling activities presuppose conceptual understanding of the mathematics involved. Mathematical...... modelling, however, can be seen as a practice of teaching that place the relation between real life and mathematics into the centre of teaching and learning mathematics, and this is relevant at all levels. Modelling activities may motivate the learning process and help the learner to establish cognitive...... roots for the construction of important mathematical concepts. In addition competences for setting up, analysing and criticising modelling processes and the possible use of models is a formative aim in this own right for mathematics teaching in general education. The paper presents a theoretical...
DEFF Research Database (Denmark)
Sørensen, John Aasted
2011-01-01
The objectives of Discrete Mathematics (IDISM2) are: The introduction of the mathematics needed for analysis, design and verification of discrete systems, including the application within programming languages for computer systems. Having passed the IDISM2 course, the student will be able...... to accomplish the following: -Understand and apply formal representations in discrete mathematics. -Understand and apply formal representations in problems within discrete mathematics. -Understand methods for solving problems in discrete mathematics. -Apply methods for solving problems in discrete mathematics......; construct a finite state machine for a given application. Apply these concepts to new problems. The teaching in Discrete Mathematics is a combination of sessions with lectures and students solving problems, either manually or by using Matlab. Furthermore a selection of projects must be solved and handed...
Mathematical Modeling and Pure Mathematics
Usiskin, Zalman
2015-01-01
Common situations, like planning air travel, can become grist for mathematical modeling and can promote the mathematical ideas of variables, formulas, algebraic expressions, functions, and statistics. The purpose of this article is to illustrate how the mathematical modeling that is present in everyday situations can be naturally embedded in…
Mentoring in mathematics education
Hyde, Rosalyn
2013-01-01
Designed to support both teachers and university-based tutors in mentoring pre-service and newly qualified mathematics teachers at both primary and secondary levels, Mentoring Mathematics Teachers offers straightforward practical advice that is based on practice, underpinned by research, and geared specifically towards this challenging subject area.Developed by members of The Association of Mathematics Education Teachers, the authors draw upon the most up-to-date research and theory to provide evidence-based practical guidance. Themes covered include:
A paradigm-based evolution of chemical engineering
Institute of Scientific and Technical Information of China (English)
Alexandru Woinaroschy
2016-01-01
A short presentation of chemical engineering evolution, as guided by its paradigms, is exposed. The first paradigm–unit operations–has emerged as a necessity of systematization due to the explosion of chemical industrial applica-tions at the end of 19th century. The birth in the late 1950s of the second paradigm–transport phenomena–was the consequence of the need for a deep, scientific knowledge of the phenomena that explain what happens inside of unit operations. In the second part of 20th century, the importance of chemical product properties and qualities has become essential y in the market fights. Accordingly, it was required with additional and even new fundamen-tal approaches, and product engineering was recognized as the third paradigm. Nowadays chemical industry, as a huge materials and energy consumer, and with a strong ecological impact, couldn't remain outside of sustainability requirements. The basics of the fourth paradigm–sustainable chemical engineering–are now formulated.
Gravimetric chemical sensors based on silica-based mesoporous organic-inorganic hybrids.
Xu, Jiaqiang; Zheng, Qi; Zhu, Yongheng; Lou, Huihui; Xiang, Qun; Cheng, Zhixuan
2014-09-01
Silica-based mesoporous organic-inorganic hybrid material modified quartz crystal microbalance (QCM) sensors have been examined for their ability to achieve highly sensitive and selective detection. Mesoporous silica SBA-15 serves as an inorganic host with large specific surface area, facilitating gas adsorption, and thus leads to highly sensitive response; while the presence of organic functional groups contributes to the greatly improved specific sensing property. In this work, we summarize our efforts in the rational design and synthesis of novel sensing materials for the detection of hazardous substances, including simulant nerve agent, organic vapor, and heavy metal ion, and develop high-performance QCM-based chemical sensors.
My contribution to broadening the base of chemical engineering.
Sargent, Roger W H
2011-01-01
This paper is a short account, from a personal viewpoint, of the various contributions I have made to expand the academic basis of chemical engineering from its origin in the unifying concept of unit operations, focussed on process design, to encompassing all the professional activities of industrial chemical engineers. This includes all aspects of planning and scheduling the operations as well as designing and controlling the process plant. The span of my career also happens to include the birth of the age of computing, with all the consequential implications.
Lai, Mun Yee; Murray, Sara
2015-01-01
Most studies of students' understanding of decimals have been conducted within Western cultural settings. The broad aim of the present research was to gain insight into Chinese Hong Kong grade 6 students' general performance on a variety of decimals tasks. More specifically, the study aimed to explore students' mathematical reasoning for their use…
Roduta Roberts, Mary; Alves, Cecilia B.; Chu, Man-Wai; Thompson, Margaret; Bahry, Louise M.; Gotzmann, Andrea
2014-01-01
The purpose of this study was to evaluate the adequacy of three cognitive models, one developed by content experts and two generated from student verbal reports for explaining examinee performance on a grade 3 diagnostic mathematics test. For this study, the items were developed to directly measure the attributes in the cognitive model. The…
Directory of Open Access Journals (Sweden)
S. V. Chernavskii
2011-01-01
Full Text Available Objective — to study prevention of cardio-cerebral complications of metabolic syndrome on the basis of mathematical methods of forecasting.Subjects and methods. A discriminant analysis of clinical and instrumental data of patients with MS.Results of this study allow the early (prenosological stages of the metabolic syndrome using the linear discriminant equations to predict thedevelopment of myocardial infarction up to 89.3 %, stroke — up to 87.8 %.Conclusion. The diagnostic and treatment algorithms developed based on the stratification of cardiovascular risk index, allow us to give sound recommendations for targeted prevention of cardio-cerebral complications.
Chase, Norma
2011-11-01
Data spanning fifteen semesters and including more than 1200 students showed far less than the anticipated difference in performance between students with quite diverse levels of physics preparation. Students ranged from those with no prior physics course work to those with two or more years of HS physics and prior courses in college physics. Less prior physics training frequently coincided with better performance in the first calculus-based course. Preparation in mathematics, on the other hand, appeared critically important; students at the extremes of the math preparation spectrum were concentrated at the corresponding extremes of the physics grade distribution.
Whether Philosophers Need Contemporary Mathematics?
Directory of Open Access Journals (Sweden)
Erovenko V. A.
2013-01-01
Full Text Available The article discusses the various problems of mathematical education of philosophers. Even a negative school experience of practical development of mathematics gives an idea of mathematics as a special item that requires in-depth study to understand it as a whole. Knowledge of mathematics dispassionately verifies readiness to grasp an abstract philosophical reasoning. The true goal of mathematical education of philosophers is not just the acquisition of specific knowledge but first of all the development of thinking or intelligence aimed at cognition which is sometimes called philosophy. In this paper we are trying to answer the question: how and why mathematics is useful for university philosophical education? In particular, speaking about the course of modern mathematics for philosophers it is emphasized that professional philosophers are in a special position – they need modern mathematics as a component of the general methodology of cognition, so not separate details of mathematical techniques but basic mathematical principles are important for them. In the context of understanding mathematics, the mathematical course for philosophers should be based on methodological foundation, where the main role is devoted to the priority philosophical questions, developing mathematical ideas, taking into account the role of the emotional components of modern mathematical education.
77 FR 18752 - Benzidine-Based Chemical Substances; Di-n
2012-03-28
... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 721 RIN 2070-AJ73 Benzidine-Based Chemical Substances; Di-n-pentyl phthalate (DnPP...-based chemical substances; a SNUR for di-n-pentyl phthalate (DnPP) (1,2-benzenedicarboxylic acid,...
Mathematical model of orbital and ground-based cross-dispersion spectrographs
Yushkin, M. V.; Fatkhullin, T. A.; Panchuk, V. E.
2016-07-01
We present the technique and algorithm of numerical modeling of high-resolution spectroscopic equipment. The software is implemented in C++ using nVidia CUDA technology. We report the results of currently developedmodeling of new-generation echelle spectrographs. To validate the algorithms used to construct the mathematical model, we present the results of modeling of NES spectrograph of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. A comparison of simulated and real images of the spectra acquired with NES spectrograph demonstrates good agreement between the model constructed and experimental data.
A Numerical Method for Rigid-plastic FEM Analysis Basing on Mathematical Programming
Institute of Scientific and Technical Information of China (English)
Li Di; Lin Zhongqin; Chen Guanlong; Zhang Weigang; Li Shuhui
2004-01-01
The rigid-plastic analysis of mental forming simulation is formulated as a discrete nonlinear mathematical programming problem with equality and inequality constraints by means of the finite element technique. An iteration algorithm is used to solve this formulation, which distinguishes the integration points of the rigid zones and the plastic zones and solves a series of the quadratic programming to overcome the difficulties caused by the nonsmoothness and the nonlinearity of the objective function. This method has been used to carry out the rigid-plastic FEM analysis. An example is given to demonstrate the effectiveness of this method.
Mathematical Model and Stability Analysis of Inverter-Based Distributed Generator
Directory of Open Access Journals (Sweden)
Alireza Khadem Abbasi
2013-01-01
Full Text Available This paper presents a mathematical (small-signal model of an electronically interfaced distributed generator (DG by considering the effect of voltage and frequency variations of the prime source. Dynamic equations are found by linearization about an operating point. In this study, the dynamic of DC part of the interface is included in the model. The stability analysis shows with proper selection of system parameters; the system is stable during steady-state and dynamic situations, and oscillatory modes are well damped. The proposed model is useful to study stability analysis of a standalone DG or a Microgrid.
Stöltzner, Michael
Answering to the double-faced influence of string theory on mathematical practice and rigour, the mathematical physicists Arthur Jaffe and Frank Quinn have contemplated the idea that there exists a `theoretical' mathematics (alongside `theoretical' physics) whose basic structures and results still require independent corroboration by mathematical proof. In this paper, I shall take the Jaffe-Quinn debate mainly as a problem of mathematical ontology and analyse it against the backdrop of two philosophical views that are appreciative towards informal mathematical development and conjectural results: Lakatos's methodology of proofs and refutations and John von Neumann's opportunistic reading of Hilbert's axiomatic method. The comparison of both approaches shows that mitigating Lakatos's falsificationism makes his insights about mathematical quasi-ontology more relevant to 20th century mathematics in which new structures are introduced by axiomatisation and not necessarily motivated by informal ancestors. The final section discusses the consequences of string theorists' claim to finality for the theory's mathematical make-up. I argue that ontological reductionism as advocated by particle physicists and the quest for mathematically deeper axioms do not necessarily lead to identical results.
A four-component organogel based on orthogonal chemical interactions.
Luisier, Nicolas; Schenk, Kurt; Severin, Kay
2014-09-14
A thermoresponsive organogel was obtained by orthogonal assembly of four compounds using dynamic covalent boronate ester and imine bonds, as well as dative boron-nitrogen bonds. It is shown that the gel state can be disrupted or reinforced by chemicals which undergo exchange reactions with the gel components.
Model Based Monitoring and Control of Chemical and Biochemical Processes
DEFF Research Database (Denmark)
Huusom, Jakob Kjøbsted
This presentation will give an overview of the work performed at the department of Chemical and Biochemical Engineering related to process control. A research vision is formulated and related to a number of active projects at the department. In more detail a project describing model estimation...
Carbon Nanostructure-Based Field-Effect Transistors for Label-Free Chemical/Biological Sensors
Directory of Open Access Journals (Sweden)
PingAn Hu
2010-05-01
Full Text Available Over the past decade, electrical detection of chemical and biological species using novel nanostructure-based devices has attracted significant attention for chemical, genomics, biomedical diagnostics, and drug discovery applications. The use of nanostructured devices in chemical/biological sensors in place of conventional sensing technologies has advantages of high sensitivity, low decreased energy consumption and potentially highly miniaturized integration. Owing to their particular structure, excellent electrical properties and high chemical stability, carbon nanotube and graphene based electrical devices have been widely developed for high performance label-free chemical/biological sensors. Here, we review the latest developments of carbon nanostructure-based transistor sensors in ultrasensitive detection of chemical/biological entities, such as poisonous gases, nucleic acids, proteins and cells.
Alba-Martínez, Jose; Trujillo, Macarena; Blasco-Gimenez, Ramon; Berjano, Enrique
2012-01-01
Radiofrequency cardiac ablation (RFCA) has been used to treat certain types of cardiac arrhythmias by producing a thermal lesion. Even though a tissue temperature higher than 50ºC is required to destroy the target, thermal mapping is not currently used during RFCA. Our aim was thus to develop mathematical models capable of estimating tissue temperature from tissue characteristics acquired or estimated at the beginning of the procedure (electrical conductivity, thermal conductivity, specific heat and density) and the applied voltage at any time. Biological tissue was considered as a system with an input (applied voltage) and output (tissue temperature), and so the mathematical models were based on transfer functions relating these variables. We used theoretical models based on finite element method to verify the mathematical models. Firstly, we solved finite element models to identify the transfer functions between the temperature at a depth of 4 mm and a constant applied voltage using a 7Fr and 4 mm electrode. The results showed that the relationships can be expressed as first-order transfer functions. Changes in electrical conductivity only affected the static gain of the system, while specific heat variations produced a change in the dynamic system response. In contrast, variations in thermal conductivity modified both the static gain and the dynamic system response. Finally, to assess the performance of the transfer functions obtained, we conducted a new set of computer simulations using a controlled temperature protocol and considering the temperature dependence of the thermal and electrical conductivities, i.e. conditions closer to those found in clinical use. The results showed that the difference between the values estimated from transfer functions and the temperatures obtained from finite element models was less than 4ºC, which suggests that the proposed method could be used to estimate tissue temperature in real time.
Mathematical modeling of the human energy metabolism based on the Selfish Brain Theory.
Chung, Matthias; Göbel, Britta
2012-01-01
Deregulations in the human energy metabolism may cause diseases such as obesity and type 2 diabetes mellitus. The origins of these pathologies are fairly unknown. The key role of the brain is the regulation of the complex whole body energy metabolism. The Selfish Brain Theory identifies the priority of brain energy supply in the competition for available energy resources within the organism. Here, we review mathematical models of the human energy metabolism supporting central aspects of the Selfish Brain Theory. First, we present a dynamical system modeling the whole body energy metabolism. This model takes into account the two central control mechanisms of the brain, i.e., allocation and appetite. Moreover, we present mathematical models of regulatory subsystems. We examine a neuronal model which specifies potential elements of the brain to sense and regulate cerebral energy content. We investigate a model of the HPA system regulating the allocation of energy within the organism. Finally, we present a robust modeling approach of appetite regulation. All models account for a systemic understanding of the human energy metabolism and thus do shed light onto defects causing metabolic diseases.
Santos, Radleigh G; Appel, Jon R; Giulianotti, Marc A; Edwards, Bruce S; Sklar, Larry A; Houghten, Richard A; Pinilla, Clemencia
2013-05-30
In the past 20 years, synthetic combinatorial methods have fundamentally advanced the ability to synthesize and screen large numbers of compounds for drug discovery and basic research. Mixture-based libraries and positional scanning deconvolution combine two approaches for the rapid identification of specific scaffolds and active ligands. Here we present a quantitative assessment of the screening of 32 positional scanning libraries in the identification of highly specific and selective ligands for two formylpeptide receptors. We also compare and contrast two mixture-based library approaches using a mathematical model to facilitate the selection of active scaffolds and libraries to be pursued for further evaluation. The flexibility demonstrated in the differently formatted mixture-based libraries allows for their screening in a wide range of assays.
Directory of Open Access Journals (Sweden)
Richard A. Houghten
2013-05-01
Full Text Available In the past 20 years, synthetic combinatorial methods have fundamentally advanced the ability to synthesize and screen large numbers of compounds for drug discovery and basic research. Mixture-based libraries and positional scanning deconvolution combine two approaches for the rapid identification of specific scaffolds and active ligands. Here we present a quantitative assessment of the screening of 32 positional scanning libraries in the identification of highly specific and selective ligands for two formylpeptide receptors. We also compare and contrast two mixture-based library approaches using a mathematical model to facilitate the selection of active scaffolds and libraries to be pursued for further evaluation. The flexibility demonstrated in the differently formatted mixture-based libraries allows for their screening in a wide range of assays.
Solovyova, N. V.; Lobkovsky, L. I.
2015-09-01
This paper proposes a method of mathematical modelling of ecological risk based on a synthesis of dynamic and probabilistic risk assessment techniques. The probability of assessment of an acceptable probability of an anthropogenic impact to minimize economic costs is proposed. The dependence of an acceptable probability of an anthropogenic impact on the ecological risk is demonstrated with an example calculation. The results of the modelling of the state of a shelf ecosystem based on the dynamic model are used for the calculation as source information. Based on this synthesis, the calculation results bring about the opportunity to balance ecological-economic goals of achieving safe development of the shelf and to satisfy the involuntary necessity to reduce the costs on environmental protection measures, while maintaining the priority of environmental requirements.
Santos, Radleigh G.; Appel, Jon R.; Giulianotti, Marc A.; Edwards, Bruce S.; Sklar, Larry A.; Houghten, Richard A.; Pinilla, Clemencia
2014-01-01
In the past 20 years, synthetic combinatorial methods have fundamentally advanced the ability to synthesize and screen large numbers of compounds for drug discovery and basic research. Mixture-based libraries and positional scanning deconvolution combine two approaches for the rapid identification of specific scaffolds and active ligands. Here we present a quantitative assessment of the screening of 32 positional scanning libraries in the identification of highly specific and selective ligands for two formylpeptide receptors. We also compare and contrast two mixture-based library approaches using a mathematical model to facilitate the selection of active scaffolds and libraries to be pursued for further evaluation. The flexibility demonstrated in the differently formatted mixture-based libraries allows for their screening in a wide range of assays. PMID:23722730
Mathematics of aperiodic order
Lenz, Daniel; Savinien, Jean
2015-01-01
What is order that is not based on simple repetition, that is, periodicity? How must atoms be arranged in a material so that it diffracts like a quasicrystal? How can we describe aperiodically ordered systems mathematically? Originally triggered by the – later Nobel prize-winning – discovery of quasicrystals, the investigation of aperiodic order has since become a well-established and rapidly evolving field of mathematical research with close ties to a surprising variety of branches of mathematics and physics. This book offers an overview of the state of the art in the field of aperiodic order, presented in carefully selected authoritative surveys. It is intended for non-experts with a general background in mathematics, theoretical physics or computer science, and offers a highly accessible source of first-hand information for all those interested in this rich and exciting field. Topics covered include the mathematical theory of diffraction, the dynamical systems of tilings or Delone sets, their cohomolog...
Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling
Energy Technology Data Exchange (ETDEWEB)
Randall S. Seright
2007-09-30
This final technical progress report describes work performed from October 1, 2004, through May 16, 2007, for the project, 'Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling'. We explored the potential of pore-filling gels for reducing excess water production from both fractured and unfractured production wells. Several gel formulations were identified that met the requirements--i.e., providing water residual resistance factors greater than 2,000 and ultimate oil residual resistance factors (F{sub rro}) of 2 or less. Significant oil throughput was required to achieve low F{sub rro} values, suggesting that gelant penetration into porous rock must be small (a few feet or less) for existing pore-filling gels to provide effective disproportionate permeability reduction. Compared with adsorbed polymers and weak gels, strong pore-filling gels can provide greater reliability and behavior that is insensitive to the initial rock permeability. Guidance is provided on where relative-permeability-modification/disproportionate-permeability-reduction treatments can be successfully applied for use in either oil or gas production wells. When properly designed and executed, these treatments can be successfully applied to a limited range of oilfield excessive-water-production problems. We examined whether gel rheology can explain behavior during extrusion through fractures. The rheology behavior of the gels tested showed a strong parallel to the results obtained from previous gel extrusion experiments. However, for a given aperture (fracture width or plate-plate separation), the pressure gradients measured during the gel extrusion experiments were much higher than anticipated from rheology measurements. Extensive experiments established that wall slip and first normal stress difference were not responsible for the pressure gradient discrepancy. To explain the discrepancy, we noted that the aperture for gel flow (for mobile gel wormholing through concentrated
Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving
Directory of Open Access Journals (Sweden)
María F. Ayllón
2016-04-01
Full Text Available This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas, flexibility (range of ideas, novelty (unique idea and elaboration (idea development. These factors contribute, among others, to the fact that schoolchildren are competent in mathematics. The problem solving and posing are a very powerful evaluation tool that shows the mathematical reasoning and creative level of a person. Creativity is part of the mathematics education and is a necessary ingredient to perform mathematical assignments. This contribution presents some important research works about problem posing and solving related to the development of mathematical knowledge and creativity. To that end, it is based on various beliefs reflected in the literature with respect to notions of creativity, problem solving and posing.
The Use of the History of Mathematics in the Teaching Pre-Service Mathematics Teachers
Galante, Dianna
2014-01-01
Many scholars have written about using the history of mathematics in the teaching of pre-service mathematics teachers. For this study, pre-service mathematics teachers developed an electronic journal of reflections based on presentations in the history of mathematics in a secondary mathematics education course. The main purpose of the…
Chemical bases for medicinal plant use in Oaxaca, Mexico.
Ortiz de Montellano, B R; Browner, C H
1985-03-01
Fifty-eight medicinal plants used for the management of reproduction and the treatment of women's reproductive health problems in an indigenous community in southern Mexico are described. The efficacy of these plants is assessed according to both community members' understandings of the therapeutic effects they seek and the standards of conventional Western medicine. The majority of the plants contain chemicals which would appear to enable them to accomplish their intended effects in either or both the popular and the conventional medical systems.
Jothi, A Lenin
2009-01-01
Financial services, particularly banking and insurance services is the prominent sector for the development of a nation. After the liberalisation of financial sector in India, the scope of getting career opportunities has been widened. It is heartening to note that various universities in India have introduced professional courses on banking and insurance. A new field of applied mathematics has come into prominence under the name of Financial Mathematics. Financial mathematics has attained much importance in the recent years because of the role played by mathematical concepts in decision - m
Pappas, Theoni
1997-01-01
In this highly readable volume of vignettes of mathematical scandals and gossip, Theoni Pappas assembles 29 fascinating stories of intrigue and the bizarre ? in short, the human background of the history of mathematics. Might a haberdasher have changed Einstein's life? Why was the first woman mathematician murdered? How come there's no Nobel Prize in mathematics?Mathematics is principally about numbers, equations, and solutions, all of them precise and timeless. But, behind this arcane matter lies the sometimes sordid world of real people, whose rivalries and deceptions
Stroud, K A
2013-01-01
A groundbreaking and comprehensive reference that's been a bestseller since it first debuted in 1970, the new seventh edition of Engineering Mathematics has been thoroughly revised and expanded. Providing a broad mathematical survey, this innovative volume covers a full range of topics from the very basic to the advanced. Whether you're an engineer looking for a useful on-the-job reference or want to improve your mathematical skills, or you are a student who needs an in-depth self-study guide, Engineering Mathematics is sure to come in handy time and time again.
Aigner, Martin; Spain, Philip G
2010-01-01
Mathematics is all around us. Often we do not realize it, though. Mathematics Everywhere is a collection of presentations on the role of mathematics in everyday life, through science, technology, and culture. The common theme is the unique position of mathematics as the art of pure thought and at the same time as a universally applicable science. The authors are renowned mathematicians; their presentations cover a wide range of topics. From compact discs to the stock exchange, from computer tomography to traffic routing, from electronic money to climate change, they make the "math inside" unde
Liu, Bo; Wu, Huayi; Wang, Yandong; Liu, Wenming
2015-01-01
Main road features extracted from remotely sensed imagery play an important role in many civilian and military applications, such as updating Geographic Information System (GIS) databases, urban structure analysis, spatial data matching and road navigation. Current methods for road feature extraction from high-resolution imagery are typically based on threshold value segmentation. It is difficult however, to completely separate road features from the background. We present a new method for extracting main roads from high-resolution grayscale imagery based on directional mathematical morphology and prior knowledge obtained from the Volunteered Geographic Information found in the OpenStreetMap. The two salient steps in this strategy are: (1) using directional mathematical morphology to enhance the contrast between roads and non-roads; (2) using OpenStreetMap roads as prior knowledge to segment the remotely sensed imagery. Experiments were conducted on two ZiYuan-3 images and one QuickBird high-resolution grayscale image to compare our proposed method to other commonly used techniques for road feature extraction. The results demonstrated the validity and better performance of the proposed method for urban main road feature extraction.
Directory of Open Access Journals (Sweden)
Bo Liu
Full Text Available Main road features extracted from remotely sensed imagery play an important role in many civilian and military applications, such as updating Geographic Information System (GIS databases, urban structure analysis, spatial data matching and road navigation. Current methods for road feature extraction from high-resolution imagery are typically based on threshold value segmentation. It is difficult however, to completely separate road features from the background. We present a new method for extracting main roads from high-resolution grayscale imagery based on directional mathematical morphology and prior knowledge obtained from the Volunteered Geographic Information found in the OpenStreetMap. The two salient steps in this strategy are: (1 using directional mathematical morphology to enhance the contrast between roads and non-roads; (2 using OpenStreetMap roads as prior knowledge to segment the remotely sensed imagery. Experiments were conducted on two ZiYuan-3 images and one QuickBird high-resolution grayscale image to compare our proposed method to other commonly used techniques for road feature extraction. The results demonstrated the validity and better performance of the proposed method for urban main road feature extraction.
Kul, Umit; Celik, Sedef
2017-01-01
This paper has been conducted to determine future teachers' mathematical beliefs and to explore the relationship between their mathematical beliefs and initial teaching practice in a classroom setting, in terms of how they design the content of teaching activities, they employed the style of teaching in mathematics, and they engaged with pupils. A…
Pace, Sydney
2000-01-01
Presents a methodology for teaching mathematical modeling skills to A-level students. Gives an example illustrating how mathematics teachers and design teachers can take joint perspective in devising learning opportunities that develop mathematical and design skills concurrently. (Contains 14 references.) (Author/ASK)
A QFD-Based Mathematical Model for New Product Development Considering the Target Market Segment
Directory of Open Access Journals (Sweden)
Liang-Hsuan Chen
2014-01-01
Full Text Available Responding to customer needs is important for business success. Quality function deployment provides systematic procedures for converting customer needs into technical requirements to ensure maximum customer satisfaction. The existing literature mainly focuses on the achievement of maximum customer satisfaction under a budgetary limit via mathematical models. The market goal of the new product for the target market segment is usually ignored. In this study, the proposed approach thus considers the target customer satisfaction degree for the target market segment in the model by formulating the overall customer satisfaction as a function of the quality level. In addition, the proposed approach emphasizes the cost-effectiveness concept in the design stage via the achievement of the target customer satisfaction degree using the minimal total cost. A numerical example is used to demonstrate the applicability of the proposed approach and its characteristics are discussed.
Complex networks and SOA: Mathematical modelling of granularity based web service compositions
Indian Academy of Sciences (India)
S Chatla; S Kadam; D Kolluru; S Sinha; A Viswandhuni; A Vaidya
2011-08-01
Service Oriented Architecture (SOA) can be deﬁned as a way of deﬁning and implementing enterprise applications that deals with the intercommunication of loosely coupled, coarse grained (business level), reusable artifacts (services). In this paper, we attempt to mathematically model the preliminary steps in the larger problem of providing an optimal architecture. The problem is treated as a complex network, particularly a process-task-network. We employ statistical and graph-theoretic methods namely, Jaccard’s distance analysis, Multiple Correspondence method and the Minimum Spanning Tree method, to ﬁnd appropriate clusters. These methods are used to cluster tasks across business processes to propose services. Additional properties and features of these clusters are discussed. We propose a leverage factor which demonstrates the importance of a task within the service and its impact on service composition.
Jung-Woon Yoo, John
2016-06-01
Since customer preferences change rapidly, there is a need for design processes with shorter product development cycles. Modularization plays a key role in achieving mass customization, which is crucial in today's competitive global market environments. Standardized interfaces among modularized parts have facilitated computational product design. To incorporate product size and weight constraints during computational design procedures, a mixed integer programming formulation is presented in this article. Product size and weight are two of the most important design parameters, as evidenced by recent smart-phone products. This article focuses on the integration of geometric, weight and interface constraints into the proposed mathematical formulation. The formulation generates the optimal selection of components for a target product, which satisfies geometric, weight and interface constraints. The formulation is verified through a case study and experiments are performed to demonstrate the performance of the formulation.
DEFF Research Database (Denmark)
Misfeldt, Morten; Zacho, Lis
2016-01-01
In this article, we address how the design of educational scenarios can support teachers’ adoption of both technology and open-ended projects indorsing creativity and innovation. We do that by describing how groups of teachers develop digital learning environments supporting using a combination...... of GeoGebra and Google sites. Both teachers and pupils work with the concept of “game” as something they design, and furthermore, the pupils immerse themselves into the scenarios that the teachers create in a way similar to “playing a game.” We investigate teachers participation in collaborative...... development and testing through qualitative means, aiming to describe the teachers’ appropriation of (1) GeoGebra as a tool for doing and teaching mathematics, and (2) game as a metaphor supporting open-ended projects addressing creativity and innovation in the classroom. The data from the project suggest...
Marković, D Z; Kalauzi, A; Radenović, C N
2001-09-01
The paper deals with mathematical modelling of the transients obtained by fitting of delayed fluorescence (DF) induction trace. The transients are in certain, doubtless connection with electrochemical gradient (ECG) formed across thylakoid membranes upon illumination. The fitting of the C and D transients by using consecutive model for first-order reactions (A --> B --> C) showed that they might play a role of the intermediate (B), according to scheme down bellow: ("A1 state")ECG (k1(C transient))--> C transient (k2(C transient))--> products, ("A2 state")ECG (k1(D transient))--> D transient (k2(D transient))--> products. The two ECG controlled "states" (A1 & A2) are not the same, which does not exclude some sort of proportionality. On the other hand, the E band, contributing mainly to the stationary level of DF induction trace, may be fitted by parallel model of at least two first-order reactions.
Schofield, Peter; Chaplain, Mark; Hubbard, Stephen
2002-01-07
In this paper we develop a novel discrete, individual-based mathematical model to investigate the effect of parasitoid foraging strategies on the spatial and temporal dynamics of host-parasitoid systems. The model is used to compare naïve or random search strategies with search strategies that depend on experience and sensitivity to semiochemicals in the environment. It focuses on simple mechanistic interactions between individual hosts, parasitoids, and an underlying field of a volatile semiochemical (emitted by the hosts during feeding) which acts as a chemoattractant for the parasitoids. The model addresses movement at different spatial scales, where scale of movement also depends on the internal state of an individual. Individual interactions between hosts and parasitoids are modelled at a discrete (micro-scale) level using probabilistic rules. The resulting within-generation dynamics produced by these interactions are then used to generate the population levels for successive generations. The model simulations examine the effect of various key parameters of the model on (i) the spatio-temporal patterns of hosts and parasitoids within generations; (ii) the population levels of the hosts and parasitoids between generations. Key results of the model simulations show that the following model parameters have an important effect on either the development of patchiness within generations or the stability/instability of the population levels between generations: (i) the rate of diffusion of the kairomones; (ii) the specific search strategy adopted by the parasitoids; (iii) the rate of host increase between successive generations. Finally, evolutionary aspects concerning competition between several parasitoid subpopulations adopting different search strategies are also examined.
Institute of Scientific and Technical Information of China (English)
曹春艳; 张定强
2012-01-01
Based on dimensions of mathematics test scores and mathematics test anxiety to discuss factors of affecting mathematics adversity quotient will benefit to reveal the internal mechanisms of mathematics learning and explore large area strategy of improving mathematics levels.165 students were conducted by self-edited mathematics adversity quotient questionnaire,mathematics test anxiety questionnaire and mid-term test scores.Results show that：there is a significant positive correlation between mathematics adversity quotient and mathematics test scores（P 0.01）,the latter has some influence on the former;there is a significant negative correlation between mathematics adversity quotient and mathematics test anxiety（P 0.01）, the relief of the latter will help the improvement of the former.%基于数学考试成绩和数学考试焦虑的维度探讨影响数学逆商的因素有利于揭示初中生数学学习过程中的真实状态,探寻大面积提高学生数学学习水平的方略.采用自编的数学逆商调查量表、数学考试焦虑量表以及学生期中数学考试成绩等对初中生进行调查.发现：初中生的数学逆商和数学考试成绩呈显著正相关（P〈0.01）,数学考试成绩对数学逆商具有显著影响作用.初中生的数学逆商和数学考试焦虑呈显著负相关（P〈0.01）,数学考试焦虑的缓解有利于数学逆商的提升.
Christensen, Anders S
2015-01-01
This report covers the development of a new, fast method for calculating the backbone amide proton chemical shifts in proteins. Through quantum chemical calculations, structure-based forudsiglese the chemical shift for amidprotonen in protein has been parameterized. The parameters are then implemented in a computer program called Padawan. The program has since been implemented in protein folding program Phaistos, wherein the method andvendes to de novo folding of the protein structures and to refine the existing protein structures.
Experimental Mathematics and Mathematical Physics
Energy Technology Data Exchange (ETDEWEB)
Bailey, David H.; Borwein, Jonathan M.; Broadhurst, David; Zudilin, Wadim
2009-06-26
One of the most effective techniques of experimental mathematics is to compute mathematical entities such as integrals, series or limits to high precision, then attempt to recognize the resulting numerical values. Recently these techniques have been applied with great success to problems in mathematical physics. Notable among these applications are the identification of some key multi-dimensional integrals that arise in Ising theory, quantum field theory and in magnetic spin theory.
Chemical composition of silica-based biocidal modifier
Directory of Open Access Journals (Sweden)
Grishina Anna Nikolaevna
2016-11-01
Full Text Available Increase of the amount of fungi spores and micotixines causes the increase in the number of different diseases. Because of this, ensuring the biological safety in buildings is becoming more and more important today. The preferred way to guarantee the biological safety of a building is to employ modern building materials that prevent the settlement of the fungi colonies on the inner surfaces of walls. Such building materials can be produced using novel biocidal modifiers that allow controlling the number of microorganisms on the surface and in the bulk of a composite construction. The precipitation product of zinc hydrosilicates and sodium sulfate is one of the mentioned modifiers. Till now, the exact chemical composition of such precipitation product is controversial; it is obvious, though, that the efficacy of the biocidal modifier is mostly determined by the type of the copper compounds. In the present work an integrated approach is used for the investigation of the chemical composition of the biocidal modifier. Such an approach consists in the examination of the modifier’s composition by means of different, yet complementary, research methods: X-ray diffraction, infrared spectroscopy and DTA. It is shown that the chemical composition of the modifier mainly depends on the amount of precipitant. X-ray diffraction reveals that the major part of the modifier is represented by amorphous phase. Along with the increase of the precipitant’s amount the crystalline phase Zn4SO4(OH6•xH2O formation takes place. Such a crystalline phase is not appropriate as a component of the biocidal modifier. Another two methods - DTA and IR spectroscopy - reveal that the amorphous phase consists essentially of zinc hydrosilicates.
Electronic and chemical properties of graphene-based structures:
DEFF Research Database (Denmark)
Vanin, Marco
hydrogen passivation. A joint experimental and theoretical study of the mechanism by which suspended graphene is etched by catalytically active silver nanoparticles have been studied. The experimental observation of zigzag channels is elucidated by the DFT calculations, which show that the armchair edges...... are easier to remove and therefore only zigzag edges are left. Finally, functionalized graphene has been investigated as catalyst for the electrochemical reduction of CO2 to chemical fuels and comparisons are made with traditional transition-metal surfaces. The investigated porphyrin-like structures...
Investigation of opening switch mechanisms based on chemically reactive plasmas
Lapatovich, W. P.; Piejak, R. B.; Proud, J. M.
1985-11-01
An investigation of discharge-induced chemical reactions resulting in high-density product vapors containing strongly attaching gases has been conducted to evaluate the feasibility and potential of such reactions in rapid opening plasma switches. This new concept of employing such reactions to limit and/or interrupt large currents on a microsecond time scale was studied in two element (electrodeless and electroded) devices and in three element (electroded) devices. Bimolecular and unimolecular reactions were considered. The plasma reaction between AlCl sub 3 and SiO sub 2 was studied. The electrical properties of one of the reaction products (SiCl sub 4) is reported.
Space-Based Chemical Lasers in Strategic Defense
2007-11-02
using <fJ*™’™ „, „,,„,,; rrÄr^ÄSXnceuea. MlRACL Chemical laser at White planned for 1995. ssssSS Sands New Mexico ^f Tit:*n s«ron»1 «>ta<J*’f...AsswnHY P«o Su<«y CS2 Secwios CaoaMitv LPE 10,412 OPE 12.323 S/C with Test Objects 12,382 Subtotal 35,117 Titan IVA Margin !32.7°.o
Validation of metabolic pathway databases based on chemical substructure search.
Félix, Liliana; Valiente, Gabriel
2007-09-01
Metabolic pathway databases such as KEGG contain information on thousands of biochemical reactions drawn from the biomedical literature. Ensuring consistency of such large metabolic pathways is essential to their proper use. In this paper, we present a new method to determine consistency of an important class of biochemical reactions. Our method exploits the knowledge of the atomic rearrangement pattern in biochemical reactions, to reduce the automatic atom mapping problem to a series of chemical substructure searches between the substrate and the product of a biochemical reaction. As an illustrative application, we describe the exhaustive validation of a substantial portion from the latest release of the KEGG LIGAND database.
Directory of Open Access Journals (Sweden)
Viktor Freiman
2011-12-01
Full Text Available Many educational systems consider using one-to-one access to the laptop as a way to improve teaching and learning. A two-year action research project on the use of laptop computers by New Brunswick (Canada grade 7 and 8 Francophone students aimed to better understand the impact of laptops on learning. Two problem-based learning (PBL interdisciplinary scenarios (math, science, language arts were implemented in eight experimental classes to measure and document students’ actual learning process, particularly in terms of their ability to scientifically investigate authentic problems, to reason mathematically, and to communicate. On-site observations, video-recording, journals, samples of students’ work, and interviews were used to collect qualitative data. Based on our findings, we argue that laptops in and of themselves may not automatically lead to better results on standardized tests, but rather create opportunities to enrich learning with more open-ended, constructive, collaborative, reflective, and cognitively complex learning tasks.
Energy Technology Data Exchange (ETDEWEB)
Silbar, R.R. [WhistleSoft, Inc., Los Alamos, NM (United States)
1998-09-28
WhistleSoft, Inc., proposed to convert a successful pedagogical experiment into multimedia software, making it accessible to a much broader audience. A colleague, Richard J. Jacob, has been teaching a workshop course in mathematical methods at Arizona State University (ASU) for lower undergraduate science majors. Students work at their own pace through paper-based tutorials containing many exercises, either with pencil and paper or with computer tools such as spreadsheets. These tutorial modules cry out for conversion into an interactive computer-based tutorial course that is suitable both for the classroom and for self-paced, independent learning. WhistleSoft has made a prototype of one such module, Legendre Polynomials, under Subcontract (No F97440018-35) with the Los Alamos Laboratory`s Technology Commercialization Office for demonstration and marketing purposes.
Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.
Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper
2011-06-01
Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.
Kodaira, Kunihiko
1996-01-01
This is the translation from the Japanese textbook for the grade 11 course, "General Mathematics". It is part of the easier of the three elective courses in mathematics offered at this level and is taken by about 40% of students. The book covers basic notions of probability and statistics, vectors, exponential, logarithmic, and trigonometric functions, and an introduction to differentiation and integration.
Kleene, Stephen Cole
2002-01-01
Undergraduate students with no prior instruction in mathematical logic will benefit from this multi-part text. Part I offers an elementary but thorough overview of mathematical logic of 1st order. Part II introduces some of the newer ideas and the more profound results of logical research in the 20th century. 1967 edition.
Talbot, Robert M.
2016-12-01
There is a clear need for valid and reliable instrumentation that measures teacher knowledge. However, the process of investigating and making a case for instrument validity is not a simple undertaking; rather, it is a complex endeavor. This paper presents the empirical case of one aspect of such an instrument validation effort. The particular instrument under scrutiny was developed in order to determine the effect of a teacher education program on novice science and mathematics teachers' strategic knowledge (SK). The relationship between novice science and mathematics teachers' SK as measured by a survey and their SK as inferred from observations of practice using a widely used observation protocol is the subject of this paper. Moderate correlations between parts of the observation-based construct and the SK construct were observed. However, the main finding of this work is that the context in which the measurement is made (in situ observations vs. ex situ survey) is an essential factor in establishing the validity of the measurement itself.
Selcen Guzey, S.; Harwell, Michael; Moreno, Mario; Peralta, Yadira; Moore, Tamara J.
2016-11-01
The new science education reform documents call for integration of engineering into K-12 science classes. Engineering design and practices are new to most science teachers, meaning that implementing effective engineering instruction is likely to be challenging. This quasi-experimental study explored the influence of teacher-developed, engineering design-based science curriculum units on learning and achievement among grade 4-8 students of different races, gender, special education status, and limited English proficiency (LEP) status. Treatment and control students (n = 4450) completed pretest and posttest assessments in science, engineering, and mathematics as well as a state-mandated mathematics test. Single-level regression results for science outcomes favored the treatment for one science assessment (physical science, heat transfer), but multilevel analyses showed no significant treatment effect. We also found that engineering integration had different effects across race and gender and that teacher gender can reduce or exacerbate the gap in engineering achievement for student subgroups depending on the outcome. Other teacher factors such as the quality of engineering-focused science units and engineering instruction were predictive of student achievement in engineering. Implications for practice are discussed.
Directory of Open Access Journals (Sweden)
Youxin Luo
2013-01-01
Full Text Available The pose of the moving platform in parallel robots is possible thanks to the strong coupling, but it consequently is very difficult to obtain its forward displacement. Different methods establishing forward displacement can obtain different numbers of variables and different solving speeds with nonlinear equations. The nonlinear equations with nine variables for forward displacement in the general 6‐6 type parallel mechanism were created using the rotation transformation matrix R , translation vector P and the constraint conditions of the rod length. Given the problems of there being only one solution and sometimes no convergence when solving nonlinear equations with the Newton method and the quasi‐Newton method, the Euler equation for free rotation in a rigid body was applied to a chaotic system by using chaos anti‐control and chaotic sequences were produced. Combining the characteristics of the chaotic sequence with the mathematical programming method, a new mathematical programming method was put forward, which was based on chaos anti‐control with the aim of solving all real solutions of nonlinear equations for forward displacement in the general 6‐6 type parallel mechanism. The numerical example shows that the new method has some positive characteristics such as that it runs in the initial value range, it has fast convergence, it can find all the possible real solutions that be found out and it proves the correctness and validity of this method when compared with other methods.
Selcen Guzey, S.; Harwell, Michael; Moreno, Mario; Peralta, Yadira; Moore, Tamara J.
2017-04-01
The new science education reform documents call for integration of engineering into K-12 science classes. Engineering design and practices are new to most science teachers, meaning that implementing effective engineering instruction is likely to be challenging. This quasi-experimental study explored the influence of teacher-developed, engineering design-based science curriculum units on learning and achievement among grade 4-8 students of different races, gender, special education status, and limited English proficiency (LEP) status. Treatment and control students ( n = 4450) completed pretest and posttest assessments in science, engineering, and mathematics as well as a state-mandated mathematics test. Single-level regression results for science outcomes favored the treatment for one science assessment (physical science, heat transfer), but multilevel analyses showed no significant treatment effect. We also found that engineering integration had different effects across race and gender and that teacher gender can reduce or exacerbate the gap in engineering achievement for student subgroups depending on the outcome. Other teacher factors such as the quality of engineering-focused science units and engineering instruction were predictive of student achievement in engineering. Implications for practice are discussed.
Transition to abstract mathematics learning mathematical thinking and writing
Maddox, Randall
2008-01-01
Constructing concise and correct proofs is one of the most challenging aspects of learning to work with advanced mathematics. Meeting this challenge is a defining moment for those considering a career in mathematics or related fields. Mathematical Thinking and Writing teaches readers to construct proofs and communicate with the precision necessary for working with abstraction. It is based on two premises: composing clear and accurate mathematical arguments is critical in abstract mathematics, and that this skill requires development and support. Abstraction is the destination, not the starting
SYNTHESIS OF PROTEINS BY NATIVE CHEMICAL LIGATION USING FMOC-BASED CHEMISTRY
Energy Technology Data Exchange (ETDEWEB)
Camarero, J A; Mitchell, A R
2005-01-20
C-terminal peptide {alpha}-thioesters are valuable intermediates in the synthesis/semisynthesis of proteins by native chemical ligation. They are prepared either by solid-phase peptide synthesis (SPPS) or biosynthetically by protein splicing techniques. The present paper reviews the different methods available for the chemical synthesis of peptide {alpha}-thioesters using Fmoc-based SPPS.
Acid-Base Chemistry According to Robert Boyle: Chemical Reactions in Words as well as Symbols
Goodney, David E.
2006-01-01
Examples of acid-base reactions from Robert Boyle's "The Sceptical Chemist" are used to illustrate the rich information content of chemical equations. Boyle required lengthy passages of florid language to describe the same reaction that can be done quite simply with a chemical equation. Reading or hearing the words, however, enriches the student's…
Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game
Orbey, Nese; Clay, Molly; Russell, T.W. Fraser
2014-01-01
An approach to explain chemical engineering through a Web-based interactive game design was developed and used with college freshman and junior/senior high school students. The goal of this approach was to demonstrate how to model a lab-scale experiment, and use the results to design and operate a chemical reactor. The game incorporates both…
Higher engineering mathematics
John Bird
2014-01-01
A practical introduction to the core mathematics principles required at higher engineering levelJohn Bird's approach to mathematics, based on numerous worked examples and interactive problems, is ideal for vocational students that require an advanced textbook.Theory is kept to a minimum, with the emphasis firmly placed on problem-solving skills, making this a thoroughly practical introduction to the advanced mathematics engineering that students need to master. The extensive and thorough topic coverage makes this an ideal text for upper level vocational courses. Now in
Dependencies in Formal Mathematics
Alama, Jesse; Urban, Josef
2011-01-01
Dependencies in formal mathematical texts, large coherent formal libraries and proof assistants are introduced as an emerging research topic, analyzed from foundational, semantic, computational, and pragmatic perspectives, and put to practical use in computer-assisted mathematics. Two different approaches to dependency computation are implemented over two major proof assistants with different type disciplines, and a large-scale experimental comparison is provided based on large Coq and Mizar formal libraries. Apart from theoretical discussions, importance of dependency analysis for advanced automation of computer-assisted reasoning, and for efficient proof analysis and theory refactoring in substantial mathematical domains are experimentally demonstrated.
SDG-based Model Validation in Chemical Process Simulation
Institute of Scientific and Technical Information of China (English)
张贝克; 许欣; 马昕; 吴重光
2013-01-01
Signed direct graph (SDG) theory provides algorithms and methods that can be applied directly to chemical process modeling and analysis to validate simulation models, and is a basis for the development of a soft-ware environment that can automate the validation activity. This paper is concentrated on the pretreatment of the model validation. We use the validation scenarios and standard sequences generated by well-established SDG model to validate the trends fitted from the simulation model. The results are helpful to find potential problems, as-sess possible bugs in the simulation model and solve the problem effectively. A case study on a simulation model of boiler is presented to demonstrate the effectiveness of this method.
Design of LTCC-based Ceramic Structure for Chemical Microreactor
Directory of Open Access Journals (Sweden)
D. Belavic
2012-04-01
Full Text Available The design of ceramic chemical microreactor for the production of hydrogen needed in portable polymer-electrolyte membrane (PEM fuel cells is presented. The microreactor was developed for the steam reforming of liquid fuels with water into hydrogen. The complex three-dimensional ceramic structure of the microreactor includes evaporator(s, mixer(s, reformer and combustor. Low-temperature co-fired ceramic (LTCC technology was used to fabricate the ceramic structures with buried cavities and channels, and thick-film technology was used to make electrical heaters, temperature sensors and pressure sensors. The final 3D ceramic structure consists of 45 LTCC tapes. The dimensions of the structure are 75 × 41 × 9 mm3 and the weight is about 73 g.
Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials
Directory of Open Access Journals (Sweden)
Franz L. Dickert
2010-03-01
Full Text Available The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has put great influence on the development of innovative chemical sensors, which can be seen from the growing number of publications in this field. The review provides a brief overview of sol-gel sensor applications, and discusses the contribution of molecular imprinting in exploring the new world of sensors.
Ping, Qingyun; Abu-Reesh, Ibrahim M; He, Zhen
2016-11-01
Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level 22.2 in order to avoid boron accumulation in the anolyte effluent.
A string matching based algorithm for performance evaluation of mathematical expression recognition
Indian Academy of Sciences (India)
P Pavan Kumar; Arun Agarwal; Chakravarthy Bhagvati
2014-02-01
In this paper, we have addressed the problem of automated performance evaluation of Mathematical Expression (ME) recognition. Automated evaluation requires that recognition output and ground truth in some editable format like LaTeX, MathML, etc. have to be matched. But standard forms can have extraneous symbols or tags. For example,
A mathematical framework for probabilistic choice based on information theory and psychophysics.
Takahashi, Taiki
2006-01-01
Risky decision-making (e.g. reward dependency) has been associated with substance abuse, psychopathy and pathological gambling; conversely, marked sensitivity to risk and uncertainty have been observed in anxiety disorder patients. In economic decision theory, probability and uncertainty have been dissociated. Frank Knight defined uncertainty as loss of information on the probability distribution of outcomes for choices (i.e., unpredictability), which is referred to as Knightian uncertainty (also as ambiguity). However, even when the probability distribution of outcomes is known, there are different degrees of predictability. In information theory, this type of degrees of uncertainty/unpredictability has been parametrized by introducing Shannon entropy. In the present paper, we show: (i) a mathematical framework combining Shannon entropy in information theory and Weber's law in psychophysics is capable of parametrizing subject's level of both aversion to probabilistic uncertainty (exaggerated in anxiety disorder patients) and reward dependency (enhanced in drug addicts and pathological gamblers), and (ii) this framework has an analogue in thermodynamics, therefore this can readily be utilized in studies in the nascent fields of neuroeconomics and econophysics as well. Future study directions for elucidating maladaptive personality characteristics in neuropsychiatric patients by using the present framework are discussed.
Mindfulness-based cognitive therapy for multiple chemical sensitivity
DEFF Research Database (Denmark)
Hauge, Christian R; Bonde, Jens Peter E; Rasmussen, Alice;
2012-01-01
no evidence-based treatments for MCS. Nevertheless, there is a substantial need for a treatment, because the condition can be severely disabling and can greatly reduce the quality of life (QOL) for those affected.In this study, we aim to assess the effects of a mindfulness-based cognitive therapy (MBCT...
Inquiry-Based Examination of Chemical Disruption of Bacterial Biofilms
Redelman, Carly V.; Hawkins, Misty A. W.; Drumwright, Franklin R.; Ransdell, Beverly; Marrs, Kathleen; Anderson, Gregory G.
2012-01-01
Inquiry-based instruction in the sciences has been demonstrated as a successful educational strategy to use for both high school and college science classrooms. As participants in the NSF Graduate STEM Fellows in K-12 Education (GK-12) Program, we were tasked with creating novel inquiry-based activities for high school classrooms. As a way to…
Leung, Jacob C K; Hilliker, Arthur J; Rezai, Pouya
2016-02-21
Chemical screening using Drosophila melanogaster (the fruit fly) is vital in drug discovery, agricultural, and toxicological applications. Oviposition (egg laying) on chemically-doped agar plates is an important read-out metric used to quantitatively assess the biological fitness and behavioral responses of Drosophila. Current oviposition-based chemical screening studies are inaccurate, labor-intensive, time-consuming, and inflexible due to the manual chemical doping of agar. In this paper, we have developed a novel hybrid agar-polydimethylsiloxane (PDMS) microfluidic device for single- and multi-concentration chemical dosing and on-chip oviposition screening of free-flying adult stage Drosophila. To achieve this, we have devised a novel technique to integrate agar with PDMS channels using ice as a sacrificial layer. Subsequently, we have conducted single-chemical toxicity and multiple choice chemical preference assays on adult Drosophila melanogaster using zinc and acetic acid at various concentrations. Our device has enabled us to 1) demonstrate that Drosophila is capable of sensing the concentration of different chemicals on a PDMS-agar microfluidic device, which plays significant roles in determining oviposition site selection and 2) investigate whether oviposition preference differs between single- and multi-concentration chemical environments. This device may be used to study fundamental and applied biological questions in Drosophila and other egg laying insects. It can also be extended in design to develop sophisticated and dynamic chemical dosing and high-throughput screening platforms in the future that are not easily achievable with the existing oviposition screening techniques.
Prediction of Drug Indications Based on Chemical Interactions and Chemical Similarities
Directory of Open Access Journals (Sweden)
Guohua Huang
2015-01-01
Full Text Available Discovering potential indications of novel or approved drugs is a key step in drug development. Previous computational approaches could be categorized into disease-centric and drug-centric based on the starting point of the issues or small-scaled application and large-scale application according to the diversity of the datasets. Here, a classifier has been constructed to predict the indications of a drug based on the assumption that interactive/associated drugs or drugs with similar structures are more likely to target the same diseases using a large drug indication dataset. To examine the classifier, it was conducted on a dataset with 1,573 drugs retrieved from Comprehensive Medicinal Chemistry database for five times, evaluated by 5-fold cross-validation, yielding five 1st order prediction accuracies that were all approximately 51.48%. Meanwhile, the model yielded an accuracy rate of 50.00% for the 1st order prediction by independent test on a dataset with 32 other drugs in which drug repositioning has been confirmed. Interestingly, some clinically repurposed drug indications that were not included in the datasets are successfully identified by our method. These results suggest that our method may become a useful tool to associate novel molecules with new indications or alternative indications with existing drugs.
Initial chemical transport of reducing elements and chemical reactions in oxide cathode base metal
Energy Technology Data Exchange (ETDEWEB)
Roquais, J.M.; Poret, F.; Doze, R. le; Dufour, P.; Steinbrunn, A
2002-11-30
In the present work, the formation of compounds associated to the diffusion of reducing elements (Mg and Al) to the nickel surface of a one-piece oxide cathode has been studied. Those compounds have been evidenced after the annealing steps at high temperature performed on cathode base metal prior to the emitting ing deposition. Therefore, they form the ''initial'' interface between the nickel and the coating, in other words, the interface existing at the beginning of cathode life. Extensive analysis to characterize the nickel base prior to coating deposition has been performed by means of scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), Auger electron spectroscopy (AES), transmission electron microscopy (TEM), and glow discharge optical emission spectroscopy (GDOES). TEM and AES analysis have allowed to identify for the first time a spinel compound of MgAl{sub 2}O{sub 4}. The preferential distribution of the different compounds on the nickel surface has been studied by EDX mapping. Experimental profiles of diffusion of the reducing elements in the nickel have been obtained over the entire thickness of the material by GDOES. The mechanism of formation of these compounds together with a related diffusion model are proposed.
Saeed, Faisal; Salim, Naomie; Abdo, Ammar
2013-07-01
Many consensus clustering methods have been applied in different areas such as pattern recognition, machine learning, information theory and bioinformatics. However, few methods have been used for chemical compounds clustering. In this paper, an information theory and voting based algorithm (Adaptive Cumulative Voting-based Aggregation Algorithm A-CVAA) was examined for combining multiple clusterings of chemical structures. The effectiveness of clusterings was evaluated based on the ability of the clustering method to separate active from inactive molecules in each cluster, and the results were compared with Ward's method. The chemical dataset MDL Drug Data Report (MDDR) and the Maximum Unbiased Validation (MUV) dataset were used. Experiments suggest that the adaptive cumulative voting-based consensus method can improve the effectiveness of combining multiple clusterings of chemical structures.
BRZOZKA, Z; COBBEN, PLHM; REINHOUDT, DN; EDEMA, JJH; KELLOGG, RM
1993-01-01
A chemically modified field-effect transistor (CHEMFET) with satisfactory Ag+ selectivity is described. The potentiometric Ag+ selectivities of CHEMFETs with plasticized PVC membranes based on macrocyclic thioethers have been determined. All the macrocyclic thioethers tested showed silver response a
Qingtongxia Aluminum Carrying Out Off-site Renovation in Ningdong Energy & Chemical Base
Institute of Scientific and Technical Information of China (English)
2008-01-01
<正>Recently,the off-site renovation project of Qingtongxia Aluminum commenced the con- struction in Linhe General Industrial Park of Ningdong Energy & Chemical Base,symboliz- ing a concrete step of Qingtongxia Aluminum
DEFF Research Database (Denmark)
Sørensen, John Aasted
2011-01-01
The objectives of Discrete Mathematics (IDISM2) are: The introduction of the mathematics needed for analysis, design and verification of discrete systems, including the application within programming languages for computer systems. Having passed the IDISM2 course, the student will be able......; construct a finite state machine for a given application. Apply these concepts to new problems. The teaching in Discrete Mathematics is a combination of sessions with lectures and students solving problems, either manually or by using Matlab. Furthermore a selection of projects must be solved and handed...
Logan, J David
2013-01-01
Praise for the Third Edition"Future mathematicians, scientists, and engineers should find the book to be an excellent introductory text for coursework or self-study as well as worth its shelf space for reference." -MAA Reviews Applied Mathematics, Fourth Edition is a thoroughly updated and revised edition on the applications of modeling and analyzing natural, social, and technological processes. The book covers a wide range of key topics in mathematical methods and modeling and highlights the connections between mathematics and the applied and nat
Handley, Bill
2012-01-01
This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud
Lee, Taek-Soo; Frey, Eric C; Tsui, Benjamin M W
2015-04-07
This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of (99m)Tc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman's rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the
Lee, Taek-Soo; Frey, Eric C.; Tsui, Benjamin M. W.
2015-04-01
This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99mTc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the
Zhang, Zili; Gao, Chao; Liu, Yuxin; Qian, Tao
2014-09-01
Ant colony optimization (ACO) algorithms often fall into the local optimal solution and have lower search efficiency for solving the travelling salesman problem (TSP). According to these shortcomings, this paper proposes a universal optimization strategy for updating the pheromone matrix in the ACO algorithms. The new optimization strategy takes advantages of the unique feature of critical paths reserved in the process of evolving adaptive networks of the Physarum-inspired mathematical model (PMM). The optimized algorithms, denoted as PMACO algorithms, can enhance the amount of pheromone in the critical paths and promote the exploitation of the optimal solution. Experimental results in synthetic and real networks show that the PMACO algorithms are more efficient and robust than the traditional ACO algorithms, which are adaptable to solve the TSP with single or multiple objectives. Meanwhile, we further analyse the influence of parameters on the performance of the PMACO algorithms. Based on these analyses, the best values of these parameters are worked out for the TSP.
Analysis of Thermal Desorption System for the Chemical Treatment of Old Storages of Oil Based Mud
Tanweer Hussain; Abdul Rehman Memon; Javed Larik
2013-01-01
This paper presents an analysis for the chemical treatment of OBM (Oil Based Mud) used in the drilling process in the oil and gas industry. The analysis is based on OBM stored at ENI (Italian National Energy) gas fields at Bhit mount district Jamshoro since the last ten years that has been chemically and physically deteriorated. Characterization of various OBM samples was performed and these samples were processed in order to evaluate the best characteristics of the OBM for optimum treatment ...
Acid-Base Chemistry of White Wine: Analytical Characterisation and Chemical Modelling
Enrico Prenesti; Silvia Berto; Simona Toso; Pier Giuseppe Daniele
2012-01-01
A chemical model of the acid-base properties is optimized for each white wine under study, together with the calculation of their ionic strength, taking into account the contributions of all significant ionic species (strong electrolytes and weak one sensitive to the chemical equilibria). Coupling the HPLC-IEC and HPLC-RP methods, we are able to quantify up to 12 carboxylic acids, the most relevant substances responsible of the acid-base equilibria of wine. The analytical concentration of car...
Dambacher, Jeffrey M; Rothlisberg, Peter C; Loneragan, Neil R
2015-01-01
A major decline in the catch of the banana prawn [shrimp], Penaeus (Fenneropenaeus) merguiensis, occurred over a six-year period in the Weipa region of the northeastern Gulf of Carpentaria, Australia. Three main hypotheses have been developed to explain this decline: (1) prawn recruitment collapsed due to overfishing; (2) recruitment collapsed due to a change in the prawn's environment; and (3) adult banana prawns were still present, but fishers could no longer effectively find or catch them. Qualitative mathematical models were used to link population biology, environmental factors, and fishery dynamics to evaluate the alternative hypotheses. This modeling approach provides the means to rapidly integrate knowledge across disciplines and consider alternative hypotheses about how the structure and function of an ecosystem affects its dynamics. Alternative models were constructed to address the different hypotheses and also to encompass a diversity of opinion about the underlying dynamics of the system. Key findings from these analyses are that: instability in the system can arise when discarded fishery bycatch supports relatively high predation pressure; system stability can be enhanced by management of fishing effort or stock catchability; catch per unit effort is not necessarily a reliable indicator of stock abundance; a change in early-season rainfall should affect all stages in the banana prawn's life cycle; and a reduced catch in the Weipa region can create and reinforce a shift in fishing effort away from Weipa. Results from the models informed an approach to test the hypotheses (i.e., an experimental fishing program), and promoted understanding of the system among researchers, management agencies, and industry. The analytical tools developed in this work to address stages of a prawn life cycle and fishery dynamics are generally applicable to any exploited natural. resource.
Semiconductor device-based sensors for gas, chemical, and biomedical applications
Ren, Fan
2011-01-01
Sales of U.S. chemical sensors represent the largest segment of the multi-billion-dollar global sensor market, which includes instruments for chemical detection in gases and liquids, biosensors, and medical sensors. Although silicon-based devices have dominated the field, they are limited by their general inability to operate in harsh environments faced with factors such as high temperature and pressure. Exploring how and why these instruments have become a major player, Semiconductor Device-Based Sensors for Gas, Chemical, and Biomedical Applications presents the latest research, including or
Institute of Scientific and Technical Information of China (English)
2010-01-01
<正>20102798 Gao Shengxiang(School of Resource and Earth Science,China University of Mining and Technology,Xuzhou 221008,China);Ye Rongzhang Establishment of Complex Geological Body FLAC3D Model by Using MATLAB Interface Program(Coal Geology & Exploration,ISSN1001-1986,CN61-1155/P,37(5),2009,p.51-53,5 illus.,4 refs.,with English abstract)Key words:FLAC3D,computer programs20102799 Li Xiuzhen(Key Laboratory of Mountain Hazards and Surface Processes,Chinese Academy of Sciences,Chengdu 610041,China);Wang Chenghua Potential Landslide Identification Model Based on Fisher Discrimination Analysis Method and Its Application(The Chinese Journal of Geological Hazard and Control,ISSN1003-8035,CN11-2825/P,20(4),2009,p.23-26,40,2 tables,11 refs.)Key words:mathematical models,landslidesAiming at ancient(old)landslides,four kinds of discrimination indexes which included nine secondary indexes for potential landslides,such as landform character,slip surface character,landslide body structure and recent activities characters,were presented.Then according to Fisher Discrimination theory,Fisher Discrimination model for the potential landslides was built.The re
Sneyd, James
2009-01-01
There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...
2016-01-01
This book provides a thorough introduction to the challenge of applying mathematics in real-world scenarios. Modelling tasks rarely involve well-defined categories, and they often require multidisciplinary input from mathematics, physics, computer sciences, or engineering. In keeping with this spirit of modelling, the book includes a wealth of cross-references between the chapters and frequently points to the real-world context. The book combines classical approaches to modelling with novel areas such as soft computing methods, inverse problems, and model uncertainty. Attention is also paid to the interaction between models, data and the use of mathematical software. The reader will find a broad selection of theoretical tools for practicing industrial mathematics, including the analysis of continuum models, probabilistic and discrete phenomena, and asymptotic and sensitivity analysis.
Yvon, Bernard R.; Walo, Trudy J.
1975-01-01
A large doll can be used to illustrate many mathematical concepts to young children. Examples of the concepts introduced with the doll include one-to-one correspondence (buttons with buttonholes) and relative sizes. (SD)
Hougardy, Stefan
2016-01-01
Algorithms play an increasingly important role in nearly all fields of mathematics. This book allows readers to develop basic mathematical abilities, in particular those concerning the design and analysis of algorithms as well as their implementation. It presents not only fundamental algorithms like the sieve of Eratosthenes, the Euclidean algorithm, sorting algorithms, algorithms on graphs, and Gaussian elimination, but also discusses elementary data structures, basic graph theory, and numerical questions. In addition, it provides an introduction to programming and demonstrates in detail how to implement algorithms in C++. This textbook is suitable for students who are new to the subject and covers a basic mathematical lecture course, complementing traditional courses on analysis and linear algebra. Both authors have given this "Algorithmic Mathematics" course at the University of Bonn several times in recent years.
Institute of Scientific and Technical Information of China (English)
无
2004-01-01
Puzzles of purely logical nature are distinguished from most mathematical puzzles,in that thought rather than memory, that is,native mental ingenuity rather than a store of acquired information, is the key to their solution.
Paper-based chemical and biological sensors: Engineering aspects.
Ahmed, Snober; Bui, Minh-Phuong Ngoc; Abbas, Abdennour
2016-03-15
Remarkable efforts have been dedicated to paper-based chemosensors and biosensors over the last few years, mainly driven by the promise of reaching the best trade-off between performance, affordability and simplicity. Because of the low-cost and rapid prototyping of these sensors, recent research has been focused on providing affordable diagnostic devices to the developing world. The recent progress in sensitivity, multi-functionality and integration of microfluidic paper-based analytical devices (µPADs), increasingly suggests that this technology is not only attractive in resource-limited environments but it also represents a serious challenger to silicon, glass and polymer-based biosensors. This review discusses the design, chemistry and engineering aspects of these developments, with a focus on the past few years.
DEFF Research Database (Denmark)
Sørensen, John Aasted
2010-01-01
The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Autumn 2010 Ectent: 5 ects Class size: 15......The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Autumn 2010 Ectent: 5 ects Class size: 15...
DEFF Research Database (Denmark)
Sørensen, John Aasted
2010-01-01
The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Spring 2010 Ectent: 5 ects Class size: 18......The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Spring 2010 Ectent: 5 ects Class size: 18...
Pestman, Wiebe R
2009-01-01
This textbook provides a broad and solid introduction to mathematical statistics, including the classical subjects hypothesis testing, normal regression analysis, and normal analysis of variance. In addition, non-parametric statistics and vectorial statistics are considered, as well as applications of stochastic analysis in modern statistics, e.g., Kolmogorov-Smirnov testing, smoothing techniques, robustness and density estimation. For students with some elementary mathematical background. With many exercises. Prerequisites from measure theory and linear algebra are presented.
Institute of Scientific and Technical Information of China (English)
2005-01-01
<正>20051134 Chen Aibing (Faculty of Land Resource Engineering, Kunming University of Science and Technology) Kunming, Yunnan 650093, China); Qin Dexian MathematicEconomical Model of No. 5 Orebody in Gejiu Tin Mine, Yunnan Province (Acta Mineralogica Sinica, ISSN 1000 - 4734, CN 52 -1045/P, 24(2), 2004, p. 171-175, 5 illus. , 5 tables, 7 refs. ) Key words: tin deposits, mathematical models, Yunnan Province
Mathematical methods for physicists
Arfken, George B
2005-01-01
This best-selling title provides in one handy volume the essential mathematical tools and techniques used to solve problems in physics. It is a vital addition to the bookshelf of any serious student of physics or research professional in the field. The authors have put considerable effort into revamping this new edition.* Updates the leading graduate-level text in mathematical physics* Provides comprehensive coverage of the mathematics necessary for advanced study in physics and engineering* Focuses on problem-solving skills and offers a vast array of exercises * Clearly illustrates and proves mathematical relationsNew in the Sixth Edition:* Updated content throughout, based on users'' feedback * More advanced sections, including differential forms and the elegant forms of Maxwell''s equations* A new chapter on probability and statistics* More elementary sections have been deleted
Visualization and mathematics III
Polthier, Konrad
2003-01-01
This research book on Mathematical Visualization contains state of the art presentations on visualization problems in mathematics, on fundamental mathematical research in computer graphics, and on software frameworks for the application of visualization to real-world problems. All contributions were written by leading experts in the field and peer-refereed by an international editorial team. The book grew out of the third international workshop "Visualization and Mathematics", which was held from May 22-25, 2002 in Berlin. The themes of the book cover important recent developments on - Geometry and Combinatorics of Meshes - Discrete Vector Fields and Topology - Geometric Modelling - Image Based Visualization - Software Environments and Applications - Education and Communication The variety of topics makes the book a suitable resource for researchers, lecturers, and practitioners; http://www-sfb288.math.tu-berlin.de/vismath/
On the Chemical Emergence of Phosphate-Based Biochemistry
Kee, Terence
Contemporary organisms use orthophosphate derivatives (PO43-) in their cell biochemistry,1 yet questions remain as to how Nature was able to accumulate, activate and exploit the or-thophosphate group from geological sources with both poorly solubility and low chemical activ-ity.2 Gulick argued3 a central role for reduced oxidation state phosphorus (P) oxyacids such as H-phosphonates (H2PO3-) and especially H-phosphinates (H2PO2-) in prebiotic chemistry on account of the greater water solubility of their metal salts and, with the presence of P-H bonds, a different reactivity profile to that expected of orthophosphate. The recent demonstration that hydrothermal corrosion of P-rich mineral phases such as schreibersite (Fe,Ni)3P within iron meteorites leads to production of various P-oxyacids including H-phosphonic (H3PO3)4 and H-phosphinic5 acids as well as orthophosphate has reignited interest in reduced oxida-tion state P chemistry in prebiotic environments. We are examining the prebiotic potential of reduced oxidation state P-chemistry through reactions with carbonyl substrates with rea-sonable prebiotic provenance including formaldehyde glycolaldehyde, both intimately involved in the formose reaction for sugar synthesis6 and pyruvic acid,7 a product of glycolysis and feed-stock for the citric acid cycle, a fundamental cellular metablic process whose heritage is considered an ancient one. In this contribution we present some of our latest results on the H-phosphinate-pyruvate system. References: [1] Lodish H et al. (2000) Molecular Cell Biology, 4th Ed., W. H. Freeman Co., New York. [2] Gulick A. (1955) Am. Sci., 43, 479. [3] Gulick A. (1957) Ann. N. Y. Acad. Sci. 69, 309. [4] Pasek M. A. (2008) Proc. Nat. Acad. Sci. USA, 105, 853. [5] Bryant D. E.and Kee T. P. (2006) Chem. Commun. 2344. [6] Weber A. L. (2000) Origins of Life and Evol. Biosph., 30, 33. [7] Cody G. D. et. al. (2000) Science 289, 1337.
Chemically induced morphology change in cluster-based nanostructures
Lando, A.; Kébaǧli, N.; Cahuzac, Ph.; Colliex, C.; Couillard, M.; Masson, A.; Schmidt, M.; Bréchignac, C.
2007-07-01
Preformed clusters carrying surfactant are used as primary blocks for the building of nano structures. Self assembly of silver atom based clusters, soft landed on a HOPG surface, generates a large variety of new architectures depending on the nature and on the concentration of the impurities. Fractal shapes fragmented into multiple compact like islands, and chain like structures might be formed. A strong local enhancement of the silver atom mobility at the surface of islands is responsible for those morphology changes.
Quantum Chemical Characterization of Single Molecule Magnets Based on Uranium.
Spivak, Mariano; Vogiatzis, Konstantinos D; Cramer, Christopher J; Graaf, Coen de; Gagliardi, Laura
2017-03-02
Multiconfigurational electronic structure theory calculations including spin-orbit coupling effects were performed on four uranium-based single-molecule-magnets. Several quartet and doublet states were computed and the energy gaps between spin-orbit states were then used to determine magnetic susceptibility curves. Trends in experimental magnetic susceptibility curves were well reproduced by the calculations, and key factors affecting performance were identified.
Bossé, Michael J.; Adu-Gyamfi, Kwaku; Chandler, Kayla; Lynch-Davis, Kathleen
2016-01-01
Dynamic mathematical environments allow users to reify mathematical concepts through multiple representations, transform mathematical relations and organically explore mathematical properties, investigate integrated mathematics, and develop conceptual understanding. Herein, we integrate Boolean algebra, the functionalities of a dynamic…
Rosa, Milton; Orey, Daniel Clark
2015-01-01
In an ethnomathematics-based program there exists the need for teachers to identify pedagogical actions in the form of teaching-learning practices. In this theoretical paper we outline a curriculum proposal based on D'Ambrosio's "Trivium," composed of "literacy," "matheracy," and "technoracy." The Trivium…
Mathematization in introductory physics
Brahmia, Suzanne M.
doing physics. It contrasts with their more common experience with mathematics as the practice of specified procedures to improve efficiency. This paper describes new curricular materials based on invention instruction provide students with opportunities to generate mathematical relationships in physics, and the paper presents preliminary evidence of the effectiveness of this method with mathematically underprepared engineering students.
Mindfulness-based cognitive therapy to treat multiple chemical sensitivities
DEFF Research Database (Denmark)
Skovbjerg, S; Hauge, Christian Riis; Rasmussen, Alice
2012-01-01
of an 8-week mindfulness-based cognitive therapy program (MBCT) for adults with MCS and to evaluate possible effects on psychological distress and illness perception. The study design was a randomized clinical trial. The MBCT programme comprised 8 weekly sessions of 2½ hours. Forty-two adults were...... screened for eligibility and 37 were included. Mean age of the participants was 51.6 years, 35 (94.6%) were female and 21 (56.8%) were unemployed. Measures of psychological distress and illness perceptions were assessed at baseline, 4 weeks, 8 weeks and at 3 months follow-up. No significant differences...
Climate-based archetypes for the environmental fate assessment of chemicals.
Ciuffo, Biagio; Sala, Serenella
2013-11-15
Emissions of chemicals have been on the rise for years, and their impacts are greatly influenced by spatial differentiation. Chemicals are usually emitted locally but their impact can be felt both locally and globally, due to their chemical properties and persistence. The variability of environmental parameters in the emission compartment may affect the chemicals' fate and the exposure at different orders of magnitude. The assessment of the environmental fate of chemicals and the inherent spatial differentiation requires the use of multimedia models at various levels of complexity (from a simple box model to complex computational and high-spatial-resolution models). The objective of these models is to support ecological and human health risk assessment, by reducing the uncertainty of chemical impact assessments. The parameterisation of spatially resolved multimedia models is usually based on scenarios of evaluative environments, or on geographical resolutions related to administrative boundaries (e.g. countries/continents) or landscape areas (e.g. watersheds, eco-regions). The choice of the most appropriate scale and scenario is important from a management perspective, as a balance should be reached between a simplified approach and computationally intensive multimedia models. In this paper, which aims to go beyond the more traditional approach based on scale/resolution (cell, country, and basin), we propose and assess climate-based archetypes for the impact assessment of chemicals released in air. We define the archetypes based on the main drivers of spatial variability, which we systematically identify by adopting global sensitivity analysis techniques. A case study that uses the high resolution multimedia model MAPPE (Multimedia Assessment of Pollutant Pathways in the Environment) is presented. Results of the analysis showed that suitable archetypes should be both climate- and chemical-specific, as different chemicals (or groups of them) have different traits
The Internet accessible mathematical computation framework
Institute of Scientific and Technical Information of China (English)
Paul S. Wang; Simon Gray; Norbert Kajler; Dongdai Lin; Weidong Liao; Xiao Zou
2004-01-01
The Internet Accessible Mathematical Computation (IAMC) framework aims to make it easy to supply mathematical computing powers over the Internet/Web. The protocol-based IAMC framework enables developers to create interoperable clients and servers easily and independently. Presented are conceptual and experimental work on the IAMC framework architecture and major components: the Mathematical Computation Protocol (MCP), a client prototype (Dragonfly), a server prototype (Starfish), a mathematical encoding converter (XMEC), and an open mathematical compute engine interface (OMEI).
Directory of Open Access Journals (Sweden)
Isukapalli Sastry S
2010-06-01
Full Text Available Abstract Background Humans are routinely and concurrently exposed to multiple toxic chemicals, including various metals and organics, often at levels that can cause adverse and potentially synergistic effects. However, toxicokinetic modeling studies of exposures to these chemicals are typically performed on a single chemical basis. Furthermore, the attributes of available models for individual chemicals are commonly estimated specifically for the compound studied. As a result, the available models usually have parameters and even structures that are not consistent or compatible across the range of chemicals of concern. This fact precludes the systematic consideration of synergistic effects, and may also lead to inconsistencies in calculations of co-occurring exposures and corresponding risks. There is a need, therefore, for a consistent modeling framework that would allow the systematic study of cumulative risks from complex mixtures of contaminants. Methods A Generalized Toxicokinetic Modeling system for Mixtures (GTMM was developed and evaluated with case studies. The GTMM is physiologically-based and uses a consistent, chemical-independent physiological description for integrating widely varying toxicokinetic models. It is modular and can be directly "mapped" to individual toxicokinetic models, while maintaining physiological consistency across different chemicals. Interaction effects of complex mixtures can be directly incorporated into the GTMM. Conclusions The application of GTMM to different individual metals and metal compounds showed that it explains available observational data as well as replicates the results from models that have been optimized for individual chemicals. The GTMM also made it feasible to model toxicokinetics of complex, interacting mixtures of multiple metals and nonmetals in humans, based on available literature information. The GTMM provides a central component in the development of a "source
Nolting, Kimberly; Nolting, Paul
2008-01-01
Research supports the effectiveness of matching instructional methods with student learning preferences (Dunn et al., 1995; Pascarella and Terenzini, 2005). Several challenges exist, however, for mathematics departments to design classroom learning experiences that allow students to learn mathematics and learn how to study math through their…
Pieters, Stefanie; Roeyers, Herbert; Rosseel, Yves; Van Waelvelde, Hilde; Desoete, Annemie
2015-01-01
A relationship between motor and mathematical skills has been shown by previous research. However, the question of whether subtypes can be differentiated within developmental coordination disorder (DCD) and/or mathematical learning disability (MLD) remains unresolved. In a sample of children with and without DCD and/or MLD, a data-driven…
Roche, Joseph; O'Neill, Arlene; Prendergast, Mark
2016-01-01
Science and mathematics education in Ireland is facing an increasing number of challenges due to economic and social change. Some of these challenges mirror international trends while others are unique to the Irish education system. In order to meet the demands that are being placed on science and mathematics education in Ireland at post-primary…
Afzal, Muhammad Tanveer; Gondal, Bashir; Fatima, Nuzhat
2014-01-01
The major objective of the study was to elicit the effect of three instructional methods for teaching of mathematics on low, average and high achiever elementary school students. Three methods: traditional instructional method, computer assisted instruction (CAI) and teacher facilitated mathematics learning software were employed for the teaching…
Liu, Po-Hung
2017-01-01
The current main research trend in mathematics education is publishing studies by Western scholars pertaining to educational issues of the world in general. but Asia is mostly overlooked. Since international comparisons show Asian students outperform others in mathematics, the imbalance should receive more attention. To gain insight into this…
Institute of Scientific and Technical Information of China (English)
郭敏
2012-01-01
The mathematical induction is an important mathematical proof,occupies an important position in the high school mathematics content,which reflects the mathematical thinking of students to further study mathematics,and understand mathematical thinking is essential.In this paper,the analogy inspired inquiry-based analysis of mathematical induction.%数学归纳法是一种重要的数学证明方法,在高中数学内容中占有重要的地位,其中体现的数学思想方法对学生进一步学习数学、领悟数学思想至关重要。本文利用类比启发探究式进行数学归纳法的分析研究。
Inquiry based learning in science education and mathematics for developing bilinguals
Directory of Open Access Journals (Sweden)
Nataliya H. Pavlova
2015-09-01
Full Text Available This article studies the problem of teaching bilingual children. A definition of “developing bilingual” is proposed. The article presents an example of the application of inquiry based learning through which students develop not only math skills but also lexical capabilities. This study offers levels of differentiation in different groups of students. The paper determines advantages and disadvantages of the use of Inquiry Based Learning in developing bilingual groups.
Inquiry based learning in science education and mathematics for developing bilinguals
Nataliya H. Pavlova; Dragomir V. Marchev; Borislav St. Borisov; Krasimir V. Harizanov
2015-01-01
This article studies the problem of teaching bilingual children. A definition of “developing bilingual” is proposed. The article presents an example of the application of inquiry based learning through which students develop not only math skills but also lexical capabilities. This study offers levels of differentiation in different groups of students. The paper determines advantages and disadvantages of the use of Inquiry Based Learning in developing bilingual groups.
Directory of Open Access Journals (Sweden)
Liu Cong
2011-12-01
Full Text Available Abstract Background Elucidating the effects of drugs on solid tumours is a highly challenging multi-level problem, since this involves many complexities associated with transport and cellular response, which in turn is characterized by highly non-linear chemical signal transduction. Appropriate systems frameworks are needed to seriously address the sources of these complexities, especially from the cellular side. Results We develop a skeletal modelling framework incorporating interstitial drug transport, intracellular signal processing and cell population descriptions. The descriptions aim to appropriately capture the nature of information flow. The model is deliberately formulated to start with simple intracellular descriptions so that additional features can be incorporated in a modular fashion. Two kinds of intracellular signalling modules which describe the drug effect were considered, one a monostable switch and the other a bistable switch. Analysis of our model revealed how different drug stimuli can lead to cell killing in the tumour. Interestingly both modules considered exhibited similar trends. The effects of important parameters were also studied. Conclusions We have created a predictive systems platform integrating drug transport and cellular response which can be systematically augmented to include additional layers of cellular complexity. Our results indicate that intracellular signalling models which are qualitatively different can give rise to similar behaviour to simple (and typical stimuli, and that validating intracellular descriptions must be performed with care by considering a variety of drug stimuli.
DEFF Research Database (Denmark)
Triantafyllou, Evangelia; Misfeldt, Morten; Timcenko, Olga
2015-01-01
approach in didactics. This theoretical framework defines the “atoms” of mathematical practice and discourse in terms of tasks, techniques, technologies and theories. We present a didactical scenario when Unity is used for introducing the calculation of reflection and refraction vectors and then we use......In this article, we present our idea of using a game engine (Unity) to teach Media Technology students mathematics-related concepts. In order to observe how the introduction of a technological tool, namely the game engine, changes the practices in mathematical work, we adopted the anthropological...... the anthropological approach to present the practices in calculating these vectors with traditional mathematics and constructing them in Unity. Then, we discuss the differences between the two cases, when we argue that Unity can benefit Media Technology students, who use mathematics as a tool. However...
Monaghan, John
2013-01-01
This paper offers a framework, an extension of Valsiner's "zone theory", for the analysis of joint student-teacher development over a series of technology-based mathematics lessons. The framework is suitable for developing research studies over a moderately long period of time and considers interrelated student-teacher development as…
Pagar, Dana
2013-01-01
Manipulatives have the potential to be powerful tools in helping children improve their number sense, develop advanced mathematical strategies, and build an understanding of the base ten number system. Physical manipulatives used in classrooms, however, are often not designed to promote efficient strategy use, such as counting on, and typically do…
Directory of Open Access Journals (Sweden)
Olga A. Iarmonova
2013-01-01
Full Text Available A fast mathematical model simulation module based on LabVIEW graphical programming environment has been developed. The module will be used for gas turbine and electrical power system co-simulation, and for testing automation of gas turbine automatic control systems.
Usta, H. Gonca
2016-01-01
This study aims to analyze the student and school level variables that affect students' self-efficacy levels in mathematics in China-Shanghai, Turkey, and Greece based on PISA 2012 results. In line with this purpose, the hierarchical linear regression model (HLM) was employed. The interschool variability is estimated at approximately 17% in…
Robinson, Michael; Tibanyendera, Basil; Seltzer-Kelly, Debbie
2007-01-01
This article reports the effects of a science, technology, and society (STS) teaching approach on the knowledge and attitudes of preservice science and mathematics teachers in Uganda toward global science and technology-based problems and/or threats. The responses of a baseline or control group (N = 50) and an experimental group (N = 50) to five…
Considerations on Duty of Mathematics Teachers Based on Dialogue Teaching%对话教学视野下数学教师职责的思考
Institute of Scientific and Technical Information of China (English)
刘清昆
2014-01-01
基于对话教学的数学课堂中教师的职责主要体现在：建构数学原始分类材料、对学生探究及对话进行专业性指导、关注课堂生成性问题。%Based on dialogue teaching, teachers’duty in mathematics classroom includes constructing mathematics original materials, guiding students to explore and dialogue and focusing on classroom generative.
Jost, Jürgen
2015-01-01
The main intention of this book is to describe and develop the conceptual, structural and abstract thinking of mathematics. Specific mathematical structures are used to illustrate the conceptual approach; providing a deeper insight into mutual relationships and abstract common features. These ideas are carefully motivated, explained and illustrated by examples so that many of the more technical proofs can be omitted. The book can therefore be used: · simply as an overview of the panorama of mathematical structures and the relations between them, to be supplemented by more detailed texts whenever you want to acquire a working knowledge of some structure · by itself as a first introduction to abstract mathematics · together with existing textbooks, to put their results into a more general perspective · to gain a new and hopefully deeper perspective after having studied such textbooks Mathematical Concepts has a broader scope and is less detaile...
Schuffenhauer, Ansgar; Brown, Nathan; Ertl, Peter; Jenkins, Jeremy L; Selzer, Paul; Hamon, Jacques
2007-01-01
Classification methods for data sets of molecules according to their chemical structure were evaluated for their biological relevance, including rule-based, scaffold-oriented classification methods and clustering based on molecular descriptors. Three data sets resulting from uniformly determined in vitro biological profiling experiments were classified according to their chemical structures, and the results were compared in a Pareto analysis with the number of classes and their average spread in the profile space as two concurrent objectives which were to be minimized. It has been found that no classification method is overall superior to all other studied methods, but there is a general trend that rule-based, scaffold-oriented methods are the better choice if classes with homogeneous biological activity are required, but a large number of clusters can be tolerated. On the other hand, clustering based on chemical fingerprints is superior if fewer and larger classes are required, and some loss of homogeneity in biological activity can be accepted.
Chemicals identified in human biological media: a data base. Third annual report, October 1981
Energy Technology Data Exchange (ETDEWEB)
Cone, M.V.; Baldauf, M.F.; Martin, F.M. (comps.)
1981-12-01
Data from almost 1600 of the 3800 body-burden documents collected to date have been entered in the data base as of October 1981. The emphasis on including recent literature and significant research documents has resulted in a chronological mix of articles from 1974 to the present. When body-burden articles are identified, data are extracted and entered in the data base by chemical and tissue/body fluid. Each data entry comprises a single record (or line entry) and is assigned a record number. If a particular document deals with more than one chemical and/or tissue, there will be multiple records for that document. For example, a study of 5 chemicals in each of 3 tissues has 15 different records (or 15 line entries) in the data base with 15 record numbers. Record numbers are assigned consecutively throughout the entire data base and appear in the upper left corner of the first column for each record.
Development of a chemical microthruster based on pulsed detonation
Wu, Ming-Hsun; Lu, Tsung-Hsun
2012-10-01
The development of a microthruster based on gaseous pulsed detonation is presented in this study. The feasibility of cyclic valveless pulsed detonation at frequencies over 100 Hz is first experimentally investigated in a microchannel with 1 mm × 0.6 mm rectangular cross-section. Highly reactive ethylene/oxygen mixtures are utilized to reduce the time and distance required for the reaction wave to run up to detonation in a smooth channel. High-speed visualizations have shown that the reaction waves reach detonative state through highly repeatable flame acceleration and deflagration-to-detonation transition processes in the channel. The validated concepts are implemented for the development of an integrated pulsed detonation microthruster. The microthruster was fabricated using low temperature co-fired ceramic tape technology. The volume of the reaction channel in the microthruster was 58 mm3. Spark electrodes and ion probes were embedded in the ceramic microthruster. The channel and via holes were fabricated using laser cutting techniques. Ion probe measurements showed that the reaction wave propagated at velocities larger than 2000 m s-1 before reaching the channel exit. The pulsed detonation microthruster has been successfully operated at frequencies as high as 200 Hz.
A synthetic biochemistry module for production of bio-based chemicals from glucose.
Opgenorth, Paul H; Korman, Tyler P; Bowie, James U
2016-06-01
Synthetic biochemistry, the cell-free production of biologically based chemicals, is a potentially high-yield, flexible alternative to in vivo metabolic engineering. To limit costs, cell-free systems must be designed to operate continuously with minimal addition of feedstock chemicals. We describe a robust, efficient synthetic glucose breakdown pathway and implement it for the production of bioplastic. The system's performance suggests that synthetic biochemistry has the potential to become a viable industrial alternative.
Challenges in Mathematical Cognition
Directory of Open Access Journals (Sweden)
Lara Alcock
2016-04-01
Full Text Available This paper reports on a collaborative exercise designed to generate a coherent agenda for research on mathematical cognition. Following an established method, the exercise brought together 16 mathematical cognition researchers from across the fields of mathematics education, psychology and neuroscience. These participants engaged in a process in which they generated an initial list of research questions with the potential to significantly advance understanding of mathematical cognition, winnowed this list to a smaller set of priority questions, and refined the eventual questions to meet criteria related to clarity, specificity and practicability. The resulting list comprises 26 questions divided into six broad topic areas: elucidating the nature of mathematical thinking, mapping predictors and processes of competence development, charting developmental trajectories and their interactions, fostering conceptual understanding and procedural skill, designing effective interventions, and developing valid and reliable measures. In presenting these questions in this paper, we intend to support greater coherence in both investigation and reporting, to build a stronger base of information for consideration by policymakers, and to encourage researchers to take a consilient approach to addressing important challenges in mathematical cognition.
Category Theory as a Formal Mathematical Foundation for Model-Based Systems Engineering
Mabrok, Mohamed
2017-01-09
In this paper, we introduce Category Theory as a formal foundation for model-based systems engineering. A generalised view of the system based on category theory is presented, where any system can be considered as a category. The objects of the category represent all the elements and components of the system and the arrows represent the relations between these components (objects). The relationship between these objects are the arrows or the morphisms in the category. The Olog is introduced as a formal language to describe a given real-world situation description and requirement writing. A simple example is provided.
Today’s and tomorrow’s bio-based bulk chemicals from white biotechnology
Hermann, B.G.; Patel, M.K.
2007-01-01
Little information is yet available on the economic viability of the production of bio-based bulk chemicals and intermediates from white biotechnology (WB). This paper details a methodology to systematically evaluate the techno-economic prospects of present and future production routes of bio-based
Directory of Open Access Journals (Sweden)
Zhaowen Chen
2014-01-01
Full Text Available Mathematical morphology (MM is an efficient nonlinear signal processing tool. It can be adopted to extract fault information from bearing signal according to a structuring element (SE. Since the bearing signal features differ for every unique cause of failure, the SEs should be well tailored to extract the fault feature from a particular signal. In the following, a signal based triangular SE according to the statistics of the magnitude of a vibration signal is proposed, together with associated methodology, which processes the bearing signal by MM analysis based on proposed SE to get the morphology spectrum of a signal. A correlation analysis on morphology spectrum is then employed to obtain the final classification of bearing faults. The classification performance of the proposed method is evaluated by a set of bearing vibration signals with inner race, ball, and outer race faults, respectively. Results show that all faults can be detected clearly and correctly. Compared with a commonly used flat SE, the correlation analysis on morphology spectrum with proposed SE gives better performance at fault diagnosis of bearing, especially the identification of the location of outer race fault and the level of fault severity.
Role-Playing Game Based Assessment to Fractional Concept in Second Grade Mathematics
Chiu, Fu-Yuan; Hsieh, Mei-Ling
2017-01-01
This study developed a set of Role-playing game (RPG), which was used to explore whether significant differences exist in academic performance and learning attitudes between RPG-based assessment and traditional lectures. This study also investigated the satisfaction of students toward the RPG scenario. Research participants included 100 second…
Smith, Carmen; King, Barbara; Gonzalez, Diana
2016-01-01
Elementary students' difficulties with angles in geometry are well documented, but we know little about how they conceptualize angles while solving problems and how their thinking changes over time. In this study, we examined 26 third and fourth grade students completing a body-based angle task supported by the Kinect for Windows. We used…
The Role of Learning Goals in Building a Knowledge Base for Elementary Mathematics Teacher Education
Jansen, Amanda; Bartell, Tonya; Berk, Dawn
2009-01-01
In this article, we describe features of learning goals that enable indexing knowledge for teacher education. Learning goals are the key enabler for building a knowledge base for teacher education; they define what counts as essential knowledge for prospective teachers. We argue that 2 characteristics of learning goals support knowledge-building…
Image analysis methods based on hierarchies of graphs and multi-scale mathematical morphology
Nacken, P.F.M.
1994-01-01
This thesis is about image analysis methods based on hierarchical graph represen-tations. A hierarchical graph representation of an image is an ordered set of graphs that represent the image on different levels of abstraction. The vertices of the graph represent image structures (lines, areas). Its