Science.gov

Sample records for diophantine frobenius problem

  1. Diophantine Optics

    NASA Astrophysics Data System (ADS)

    Rouan, D.

    2016-09-01

    What I call Diophantine optics is the exploitation in optics of some remarkable algebraic relations between powers of integers. The name comes from Diophantus of Alexandria, a greek mathematician, known as the father of algebra. He studied polynomial equations with integer coefficients and integer solutions, called diophantine equations. Since constructive or destructive interferences are playing with optical path differences which are multiple integer (odd or even) of λ/2 and that the complex amplitude is a highly non-linear function of the optical path difference (or equivalently of the phase), one can understand that any Taylor development of this amplitude implies powers of integers. This is the link with Diophantine equations. We show how, especially in the field of interferometry, remarkable relations between powers of integers can help to solve several problems, such as achromatization of a phase shifter or deep nulling efficiency. It appears that all the research that was conducted in this frame of thinking, relates to the field of detection of exoplanets, a very active domain of astrophysics today.

  2. Diophantine equations related to quasicrystals: A note

    NASA Astrophysics Data System (ADS)

    Pelantová, E.; Perelomov, A. M.

    1998-06-01

    We give the general solution of three Diophantine equations in the ring of integer of the algebraic number field ${\\bf Q}[{\\sqr 5}]$. These equations are related to the problem of determination of the minimum distance in quasicrystals with fivefold symmetry.

  3. Conjectures and results on the size and number of Diophantine tuples

    NASA Astrophysics Data System (ADS)

    Dujella, Andrej

    2008-01-01

    The problem of the construction of Diophantine m-tuples, i.e. sets with the property that the product of any two of its distinct elements is one less then a square, has a very long history. In this survey, we describe several conjectures and recent results concerning Diophantine m-tuples and their generalizations.

  4. Frobenius manifolds and Frobenius algebra-valued integrable systems

    NASA Astrophysics Data System (ADS)

    Strachan, Ian A. B.; Zuo, Dafeng

    2017-06-01

    The notion of integrability will often extend from systems with scalar-valued fields to systems with algebra-valued fields. In such extensions the properties of, and structures on, the algebra play a central role in ensuring integrability is preserved. In this paper, a new theory of Frobenius algebra-valued integrable systems is developed. This is achieved for systems derived from Frobenius manifolds by utilizing the theory of tensor products for such manifolds, as developed by Kaufmann (Int Math Res Not 19:929-952, 1996), Kontsevich and Manin (Inv Math 124: 313-339, 1996). By specializing this construction, using a fixed Frobenius algebra A, one can arrive at such a theory. More generally, one can apply the same idea to construct an A-valued topological quantum field theory. The Hamiltonian properties of two classes of integrable evolution equations are then studied: dispersionless and dispersive evolution equations. Application of these ideas are discussed, and as an example, an A-valued modified Camassa-Holm equation is constructed.

  5. Grover's quantum search algorithm and Diophantine approximation

    SciTech Connect

    Dolev, Shahar; Pitowsky, Itamar; Tamir, Boaz

    2006-02-15

    In a fundamental paper [Phys. Rev. Lett. 78, 325 (1997)] Grover showed how a quantum computer can find a single marked object in a database of size N by using only O({radical}(N)) queries of the oracle that identifies the object. His result was generalized to the case of finding one object in a subset of marked elements. We consider the following computational problem: A subset of marked elements is given whose number of elements is either M or K, our task is to determine which is the case. We show how to solve this problem with a high probability of success using iterations of Grover's basic step only, and no other algorithm. Let m be the required number of iterations; we prove that under certain restrictions on the sizes of M and K the estimation m<2{radical}(N)/({radical}(K)-{radical}(M)) obtains. This bound reproduces previous results based on more elaborate algorithms, and is known to be optimal up to a constant factor. Our method involves simultaneous Diophantine approximations, so that Grover's algorithm is conceptualized as an orbit of an ergodic automorphism of the torus. We comment on situations where the algorithm may be slow, and note the similarity between these cases and the problem of small divisors in classical mechanics.

  6. On the Frobenius problem for three arguments

    NASA Astrophysics Data System (ADS)

    Vorob'ev, I. S.

    2016-06-01

    Asymptotic formulae for the mean values of various characteristics of the additive semigroup generated by three positive integers are obtained theoretically, the first of which is a formula for the number of integers not belonging to this semigroup. A numerical experiment is described which validates the results obtained. Bibliography: 21 titles.

  7. One Interesting Family of Diophantine Triplets

    ERIC Educational Resources Information Center

    Deshpande, M. N.

    2002-01-01

    In this note properties of two sequences generated by the recurrence relation G[subscript n] +2 = 4 G[subscript n] +1 - G[subscript n], are studied. It is shown that one of the sequences leads to a family of diophantine triplets. Some interesting properties of these sequences are also established.

  8. Un scindage du morphisme de Frobenius quantique

    NASA Astrophysics Data System (ADS)

    Gros, Michel; Kaneda, Masaharu

    2015-10-01

    We show that the quantum Frobenius morphism constructed by Lusztig in the setting of the quantum enveloping algebra specialized at a root of unity admits a (nonunital) multiplicative splitting. We construct the splitting using a basis of the toral part of the small quantum algebra consisting of pairwise orthogonal idempotents summing up to 1, and likewise in the modular case of the algebra of distributions for a semisimple algebraic group.

  9. Frobenius-Chern-Simons gauge theory

    NASA Astrophysics Data System (ADS)

    Bonezzi, Roberto; Boulanger, Nicolas; Sezgin, Ergin; Sundell, Per

    2017-02-01

    Given a set of differential forms on an odd-dimensional noncommutative manifold valued in an internal associative algebra H , we show that the most general cubic covariant Hamiltonian action, without mass terms, is controlled by an {{{Z}}2} -graded associative algebra F with a graded symmetric nondegenerate bilinear form. The resulting class of models provide a natural generalization of the Frobenius-Chern-Simons model (FCS) that was proposed in (arXiv:1505.04957) as an off-shell formulation of the minimal bosonic four-dimensional higher spin gravity theory. If F is unital and the {{{Z}}2} -grading is induced from a Klein operator that is outer to a proper Frobenius subalgebra, then the action can be written on a form akin to topological open string field theory in terms of a superconnection valued in H\\otimes F . We give a new model of this type based on a twisting of {C}≤ft[{{{Z}}2}× {{{Z}}4}\\right] , which leads to self-dual complexified gauge fields on AdS 4. If F is 3-graded, the FCS model can be truncated consistently as to contain no zero-form constraints on-shell. Two examples thereof are a twisting of {C}[{{({{{Z}}2})}3}] that yields the original model, and the Clifford algebra C{{\\ell}2n} which provides an FCS formulation of the bosonic Konstein-Vasiliev model with gauge algebra hu≤ft({{4}n-1},0\\right) .

  10. Effective Perron-Frobenius eigenvalue for a correlated random map.

    PubMed

    Pool, Roman R; Cáceres, Manuel O

    2010-09-01

    We investigate the evolution of random positive linear maps with various type of disorder by analytic perturbation and direct simulation. Our theoretical result indicates that the statistics of a random linear map can be successfully described for long time by the mean-value vector state. The growth rate can be characterized by an effective Perron-Frobenius eigenvalue that strongly depends on the type of correlation between the elements of the projection matrix. We apply this approach to an age-structured population dynamics model. We show that the asymptotic mean-value vector state characterizes the population growth rate when the age-structured model has random vital parameters. In this case our approach reveals the nontrivial dependence of the effective growth rate with cross correlations. The problem was reduced to the calculation of the smallest positive root of a secular polynomial, which can be obtained by perturbations in terms of Green's function diagrammatic technique built with noncommutative cumulants for arbitrary n -point correlations.

  11. Flat coordinates for Saito Frobenius manifolds and string theory

    NASA Astrophysics Data System (ADS)

    Belavin, A. A.; Gepner, D.; Kononov, Ya. A.

    2016-12-01

    We investigate the connection between the models of topological conformal theory and noncritical string theory with Saito Frobenius manifolds. For this, we propose a new direct way to calculate the flat coordinates using the integral representation for solutions of the Gauss-Manin system connected with a given Saito Frobenius manifold. We present explicit calculations in the case of a singularity of type A n . We also discuss a possible generalization of our proposed approach to SU( N) k /( SU( N) k+1 × U(1)) Kazama-Suzuki theories. We prove a theorem that the potential connected with these models is an isolated singularity, which is a condition for the Frobenius manifold structure to emerge on its deformation manifold. This fact allows using the Dijkgraaf-Verlinde-Verlinde approach to solve similar Kazama-Suzuki models.

  12. Analysis of Quadratic Diophantine Equations with Fibonacci Number Solutions

    ERIC Educational Resources Information Center

    Leyendekkers, J. V.; Shannon, A. G.

    2004-01-01

    An analysis is made of the role of Fibonacci numbers in some quadratic Diophantine equations. A general solution is obtained for finding factors in sums of Fibonacci numbers. Interpretation of the results is facilitated by the use of a modular ring which also permits extension of the analysis.

  13. Analysis of Quadratic Diophantine Equations with Fibonacci Number Solutions

    ERIC Educational Resources Information Center

    Leyendekkers, J. V.; Shannon, A. G.

    2004-01-01

    An analysis is made of the role of Fibonacci numbers in some quadratic Diophantine equations. A general solution is obtained for finding factors in sums of Fibonacci numbers. Interpretation of the results is facilitated by the use of a modular ring which also permits extension of the analysis.

  14. Applications of Perron-Frobenius theory to population dynamics.

    PubMed

    Li, Chi-Kwong; Schneider, Hans

    2002-05-01

    By the use of Perron-Frobenius theory, simple proofs are given of the Fundamental Theorem of Demography and of a theorem of Cushing and Yicang on the net reproductive rate occurring in matrix models of population dynamics. The latter result, which is closely related to the Stein-Rosenberg theorem in numerical linear algebra, is further refined with some additional nonnegative matrix theory. When the fertility matrix is scaled by the net reproductive rate, the growth rate of the model is $1$. More generally, we show how to achieve a given growth rate for the model by scaling the fertility matrix. Demographic interpretations of the results are given.

  15. A Perron-Frobenius Type of Theorem for Quantum Operations

    NASA Astrophysics Data System (ADS)

    Lagro, Matthew; Yang, Wei-Shih; Xiong, Sheng

    2017-08-01

    We define a special class of quantum operations we call Markovian and show that it has the same spectral properties as a corresponding Markov chain. We then consider a convex combination of a quantum operation and a Markovian quantum operation and show that under a norm condition its spectrum has the same properties as in the conclusion of the Perron-Frobenius theorem if its Markovian part does. Moreover, under a compatibility condition of the two operations, we show that its limiting distribution is the same as the corresponding Markov chain. We apply our general results to partially decoherent quantum random walks with decoherence strength 0 ≤ p ≤ 1 . We obtain a quantum ergodic theorem for partially decoherent processes. We show that for 0 < p ≤ 1 , the limiting distribution of a partially decoherent quantum random walk is the same as the limiting distribution for the classical random walk.

  16. A Perron-Frobenius Type of Theorem for Quantum Operations

    NASA Astrophysics Data System (ADS)

    Lagro, Matthew; Yang, Wei-Shih; Xiong, Sheng

    2017-10-01

    We define a special class of quantum operations we call Markovian and show that it has the same spectral properties as a corresponding Markov chain. We then consider a convex combination of a quantum operation and a Markovian quantum operation and show that under a norm condition its spectrum has the same properties as in the conclusion of the Perron-Frobenius theorem if its Markovian part does. Moreover, under a compatibility condition of the two operations, we show that its limiting distribution is the same as the corresponding Markov chain. We apply our general results to partially decoherent quantum random walks with decoherence strength 0 ≤ p ≤ 1. We obtain a quantum ergodic theorem for partially decoherent processes. We show that for 0 < p ≤ 1, the limiting distribution of a partially decoherent quantum random walk is the same as the limiting distribution for the classical random walk.

  17. Integrability of the Frobenius algebra-valued Kadomtsev-Petviashvili hierarchy

    NASA Astrophysics Data System (ADS)

    Strachan, Ian A. B.; Zuo, Dafeng

    2015-11-01

    We introduce a Frobenius algebra-valued Kadomtsev-Petviashvili (KP) hierarchy and show the existence of Frobenius algebra-valued τ-function for this hierarchy. In addition, we construct its Hamiltonian structures by using the Adler-Dickey-Gelfand method. As a byproduct of these constructions, we show that the coupled KP hierarchy, defined by Casati and Ortenzi [J. Geom. Phys. 56, 418-449 (2006)], has at least n-"basic" different local bi-Hamiltonian structures. Finally, via the construction of the second Hamiltonian structures, we obtain some local matrix, or Frobenius algebra-valued, generalizations of classical W-algebras.

  18. ON FROBENIUS PAIRS OF THE FORM (F\\leftthreetimes V,\\, V)

    NASA Astrophysics Data System (ADS)

    Shunkov, V. P.

    1991-02-01

    A nonsimplicity test for groups is obtained which is connected with certain Frobenius pairs. In the case of finite groups it is a natural complement to Glauberman's familiar Z^*-theorem.Bibliography: 10 titles.

  19. Frobenius-norm-based measures of quantum coherence and asymmetry

    NASA Astrophysics Data System (ADS)

    Yao, Yao; Dong, G. H.; Xiao, Xing; Sun, C. P.

    2016-08-01

    We formulate the Frobenius-norm-based measures for quantum coherence and asymmetry respectively. In contrast to the resource theory of coherence and asymmetry, we construct a natural measure of quantum coherence inspired from optical coherence theory while the group theoretical approach is employed to quantify the asymmetry of quantum states. Besides their simple structures and explicit physical meanings, we observe that these quantities are intimately related to the purity (or linear entropy) of the corresponding quantum states. Remarkably, we demonstrate that the proposed coherence quantifier is not only a measure of mixedness, but also an intrinsic (basis-independent) quantification of quantum coherence contained in quantum states, which can also be viewed as a normalized version of Brukner-Zeilinger invariant information. In our context, the asymmetry of N-qubit quantum systems is considered under local independent and collective transformations. In- triguingly, it is illustrated that the collective effect has a significant impact on the asymmetry measure, and quantum correlation between subsystems plays a non-negligible role in this circumstance.

  20. Frobenius-norm-based measures of quantum coherence and asymmetry

    PubMed Central

    Yao, Yao; Dong, G. H.; Xiao, Xing; Sun, C. P.

    2016-01-01

    We formulate the Frobenius-norm-based measures for quantum coherence and asymmetry respectively. In contrast to the resource theory of coherence and asymmetry, we construct a natural measure of quantum coherence inspired from optical coherence theory while the group theoretical approach is employed to quantify the asymmetry of quantum states. Besides their simple structures and explicit physical meanings, we observe that these quantities are intimately related to the purity (or linear entropy) of the corresponding quantum states. Remarkably, we demonstrate that the proposed coherence quantifier is not only a measure of mixedness, but also an intrinsic (basis-independent) quantification of quantum coherence contained in quantum states, which can also be viewed as a normalized version of Brukner-Zeilinger invariant information. In our context, the asymmetry of N-qubit quantum systems is considered under local independent and collective transformations. In- triguingly, it is illustrated that the collective effect has a significant impact on the asymmetry measure, and quantum correlation between subsystems plays a non-negligible role in this circumstance. PMID:27558009

  1. About some diophantine equation and the resulting chaos in geodesics

    NASA Astrophysics Data System (ADS)

    Perrine, Serge

    2001-06-01

    We announce results about a complete Markoff theory for the diophantine equation: x2+y2+z2=3xyz+2x All its solutions can be computed. For positive integers, they are organized in two trees. With them, we build a new tree thanks to related continued fractions, and associated binary quadratic forms. In an infinite number of cases, the corresponding approximation and Markoff constants have the form: ((m-2)/√9m2-4 ) For other cases, we conjecture the expression of the constants. All of them converge towards (1/3) by lower values, similarly but differently from the classical Markoff theory. We conclude considering very briefly the link between such equations and geodesics on some Riemann surfaces.

  2. Identities for Apostol-type Frobenius-Euler polynomials resulting from the study of a nonlinear operator

    NASA Astrophysics Data System (ADS)

    Bayad, A.; Kim, T.

    2016-04-01

    We introduce a special nonlinear differential operator and, using its properties, reduce higher-order Frobenius-Euler Apostol-type polynomials to a finite series of first-order Apostol-type Frobenius-Euler polynomials and Stirling numbers. Interesting identities are established.

  3. Lepton mixing, residual symmetries, and trigonometric Diophantine equations

    NASA Astrophysics Data System (ADS)

    Hu, Bo

    2014-10-01

    In this paper, we study residual symmetries in the lepton sector. Our first concern is the symmetry of the charged lepton mass matrix in the basis where the Majorana neutrino mass matrix is diagonal, which is strongly constrained by the requirement that the symmetry group generated by residual symmetries is finite. In a recent work, R. M. Fonseca and W. Grimus found that there exists a set of constraint equations that can be completely solved, which is essential in their approach to the classification of lepton mixing matrices that are fully determined by residual symmetries. In this paper, a method to handle trigonometric Diophantine equations is introduced. We will show that the constraint equations found by Fonseca and Grimus can also be solved by this method. Detailed derivation and discussion will be presented in a self-contained way. In addition, we will also show that, in the case where residual symmetries satisfy a reality condition, this method can be used to solve the equation constraining parameters in the symmetry assignment that controls the group structure generated by residual symmetries and is directly related to mixing matrix elements.

  4. Diophantine equations, Platonic solids, McKay correspondence, equivelar maps and Vogel's universality

    NASA Astrophysics Data System (ADS)

    Khudaverdian, H. M.; Mkrtchyan, R. L.

    2017-04-01

    We notice that one of the Diophantine equations, knm = 2 kn + 2 km + 2 nm, arising in the universality originated Diophantine classification of simple Lie algebras, has interesting interpretations for two different sets of signs of variables. In both cases it describes ;regular polyhedra; with k edges in each vertex, n edges of each face, with total number of edges | m |, and Euler characteristics χ = ± 2. In the case of negative m this equation corresponds to χ = 2 and describes true regular polyhedra, Platonic solids. The case with positive m corresponds to Euler characteristic χ = - 2 and describes the so called equivelar maps (charts) on the surface of genus 2. In the former case there are two routes from Platonic solids to simple Lie algebras-abovementioned Diophantine classification and McKay correspondence. We compare them for all solutions of this type, and find coincidence in the case of icosahedron (dodecahedron), corresponding to E8 algebra. In the case of positive k, n and m we obtain in this way the interpretation of (some of) the mysterious solutions (Y-objects), appearing in the Diophantine classification and having some similarities with simple Lie algebras.

  5. Dynamics of a Skew Tent Map in the Nonlinear Frobenius-Perron Equation

    NASA Astrophysics Data System (ADS)

    Katsuragi, Daisuke

    Return maps of the mean field in globally coupled map lattices (GCML) with a large system size were compared with those at the limit in a large system size. We adopted a nonlinear Frobenius-Perron equation (NFPE) for the limit in the large system size, and used a skew tent map as a chaotic map to simplify calculations in the NFPE. The return maps of the mean field for direct numerical calculations in the GCML usually fluctuate from those for numerical calculations in the NFPE. However, at some coupling strengths, there are totally different return maps between the GCML and the NFPE. We show that this strongly depends on the initial conditions at some coupling strengths.

  6. Bounds for departure from normality and the Frobenius norm of matrix eigenvalues

    SciTech Connect

    Lee, S.L.

    1994-12-01

    New lower and upper bounds for the departure from normality and the Frobenius norm of the eigenvalues of a matrix axe given. The significant properties of these bounds axe also described. For example, the upper bound for matrix eigenvalues improves upon the one derived by Kress, de Vries and Wegmann in [Lin. Alg. Appl., 8 (1974), pp. 109-120]. The upper bound for departure from normality is sharp for any matrix whose eigenvalues are collinear in the complex plane. Moreover, the latter formula is a practical estimate that costs (at most) 2m multiplications, where m is the number of nonzeros in the matrix. In terms of applications, the results can be used to bound from above the sensitivity of eigenvalues to matrix perturbations or bound from below the condition number of the eigenbasis of a matrix.

  7. An Application of the Perron-Frobenius Theorem to a Damage Model Problem.

    DTIC Science & Technology

    1985-04-01

    be probability " distributions, and k > 0 and k > 0 be fixed integers. Define S i sup{S(+mk i+ko+ nk1 ) k0 J+mkl< i+k +nk 1.i j 101 m>_0, n>_0, k0 j...many distributions {g with probability generating tha ther exith probability en a functions G such that G (1- ir +nt) c G *(’t),ItI<_l. Define . )rY (1

  8. Ergodic theory and Diophantine approximation for translation surfaces and linear forms

    NASA Astrophysics Data System (ADS)

    Athreya, Jayadev; Parrish, Andrew; Tseng, Jimmy

    2016-08-01

    We derive results on the distribution of directions of saddle connections on translation surfaces using only the Birkhoff ergodic theorem applied to the geodesic flow on the moduli space of translation surfaces. Our techniques, together with an approximation argument, also give an alternative proof of a weak version of a classical theorem in multi-dimensional Diophantine approximation due to Schmidt (1960 Can. J. Math. 12 619-31, 1964 Trans. Am. Math. Soc. 110 493-518). The approximation argument allows us to deduce the Birkhoff genericity of almost all lattices in a certain submanifold of the space of unimodular lattices from the Birkhoff genericity of almost all lattices in the whole space and similarly for the space of affine unimodular lattices.

  9. Linear Forms in the Values of G-FUNCTIONS, and Diophantine Equations

    NASA Astrophysics Data System (ADS)

    Matveev, E. M.

    1983-04-01

    Using a rather general theorem on G-functions proved in this paper, the author establishes the existence of an effective upper bound for the solutions of certain Diophantine equations, such as those of the form \\displaystyle a_1x^g_1-a_2x^g_2=p_1^{z_1}\\cdots p_k^{z_k}G(x_1,x_2),where a_1,a_2 and p_1,\\dots,p_k are natural numbers and G(x_1, x_2) is a polynomial of small degree. The upper bound has the form \\displaystyle \\max(\\vert x_1\\vert,\\vert x_2\\vert)\\leqslant(\\xi H(G))^{1/(g-\\gamma-\\operatorname{deg}G)},where \\gamma depends on a_1,a_2 and p_1,\\dots,p_k and can be written out explicitly, and \\xi is an effective positive constant.Bibliography: 17 titles.

  10. The local Hurwitz constant and Diophantine approximation on Hecke groups

    NASA Astrophysics Data System (ADS)

    Lehner, J.

    1990-10-01

    Define the Hecke group by {G_q} = < {( {begin{array}{*{20}{c}} 1 & {{⪉mb... ...{array}{*{20}{c}} 0 & { - 1} 1 & 0 } )} rangle , {λ _q} = 2cos π /q , q = 3,4, ldots . We call {G_q}(∞ ) the {G_q} -rationals, and R - {G_q}(∞ ) the {G_q} -irrationals. The problem we treat here is the approximation of {G_q} -irrationals by {G_q} -rationals. Let M(α ) be the upper bound of numbers c for which \\vertα - k/m\\vert < 1/c{m^2} for all {G_q} -irrationals and infinitely many k/m in {G_q}(∞ ) . Set h_q'= {inf _α }M(α ) . We call h_q' the Hurwitz constant for {G_q} . It is known that h_q'= 2 , q even; h_q'= 2{(1 + {(1 - {λ _q}/2)^2})^{1/2}} , q odd. In this paper we prove this result by using {λ _q} -continued fractions, as developed previously by D. Rosen. Write α - frac{{{P_{n - 1}}}}{{{Q_{n - 1}}}} = frac{{{{( - 1)}^{... ...}{\\varepsilon _2} \\cdots {\\varepsilon _n}}}{{{m_{n - 1}}(α )Q_{n - 1}^2}}, where {\\varepsilon _i} = ± 1 and {P_i}/{Q_i} are the convergents of the {λ _q} -continued fraction for α . Then M(α ) = {overline {lim } _n}{m_n}(α ) . We call {m_n}(α ) the local Hurwitz constant. In the final section we prove some results on the local Hurwitz constant. For example (Theorem 4), it is shown that if q is odd and {\\varepsilon _{n + 1}} = {\\varepsilon _{n + 2}} = + 1 , then {m_i} ≥ {(λ _q^2 + 4)^{1/2}} > h_q' for at least one of i = n - 1,n,n + 1 .

  11. Modelling Problem-Solving Situations into Number Theory Tasks: The Route towards Generalisation

    ERIC Educational Resources Information Center

    Papadopoulos, Ioannis; Iatridou, Maria

    2010-01-01

    This paper examines the way two 10th graders cope with a non-standard generalisation problem that involves elementary concepts of number theory (more specifically linear Diophantine equations) in the geometrical context of a rectangle's area. Emphasis is given on how the students' past experience of problem solving (expressed through interplay…

  12. Fourier transforms on Cantor sets: A study in non-Diophantine arithmetic and calculus

    NASA Astrophysics Data System (ADS)

    Aerts, Diederik; Czachor, Marek; Kuna, Maciej

    2016-10-01

    Fractals equipped with intrinsic arithmetic lead to a natural definition of differentiation, integration and complex numbers. Applying the formalism to the problem of a Fourier transform on fractals we show that the resulting transform has all the expected basic properties. As an example we discuss a sawtooth signal on the ternary middle-third Cantor set. The formalism works also for fractals that are not self-similar.

  13. Public channel cryptography: chaos synchronization and Hilbert's tenth problem.

    PubMed

    Kanter, Ido; Kopelowitz, Evi; Kinzel, Wolfgang

    2008-08-22

    The synchronization process of two mutually delayed coupled deterministic chaotic maps is demonstrated both analytically and numerically. The synchronization is preserved when the mutually transmitted signals are concealed by two commutative private filters, a convolution of the truncated time-delayed output signals or some powers of the delayed output signals. The task of a passive attacker is mapped onto Hilbert's tenth problem, solving a set of nonlinear Diophantine equations, which was proven to be in the class of NP-complete problems [problems that are both NP (verifiable in nondeterministic polynomial time) and NP-hard (any NP problem can be translated into this problem)]. This bridge between nonlinear dynamics and NP-complete problems opens a horizon for new types of secure public-channel protocols.

  14. On applications of diophantine approximations

    PubMed Central

    Chudnovsky, G. V.

    1984-01-01

    This paper is devoted to the study of the arithmetic properties of values of G-functions introduced by Siegel [Siegel, C. L. (1929) Abh. Preuss. Akad. Wiss. Phys.-Math. Kl. 1]. One of the main results is a theorem on the linear independence of values of G-functions at rational points close to the origin. In this theorem, no conditions are imposed on the p-adic convergence of a G-function at a generic point. The theorem finally realizes Siegel's program on G-function values outlined in his paper. PMID:16593530

  15. A singular one-dimensional bound state problem and its degeneracies

    NASA Astrophysics Data System (ADS)

    Erman, Fatih; Gadella, Manuel; Tunalı, Seçil; Uncu, Haydar

    2017-08-01

    We give a brief exposition of the formulation of the bound state problem for the one-dimensional system of N attractive Dirac delta potentials, as an N × N matrix eigenvalue problem (Φ A =ω A). The main aim of this paper is to illustrate that the non-degeneracy theorem in one dimension breaks down for the equidistantly distributed Dirac delta potential, where the matrix Φ becomes a special form of the circulant matrix. We then give elementary proof that the ground state is always non-degenerate and the associated wave function may be chosen to be positive by using the Perron-Frobenius theorem. We also prove that removing a single center from the system of N delta centers shifts all the bound state energy levels upward as a simple consequence of the Cauchy interlacing theorem.

  16. BAROCLINIC INSTABILITY IN THE SOLAR TACHOCLINE. II. THE EADY PROBLEM

    SciTech Connect

    Gilman, Peter A.

    2016-02-20

    We solve the nongeostrophic baroclinic instability problem for the tachocline for a continuous model with a constant vertical rotation gradient (the Eady problem), using power series generated by the Frobenius method. The results confirm and greatly extend those from a previous two-layer model. For effective gravity G independent of height, growth rates and ranges of unstable longitudinal wavenumbers m and latitudes increase with decreasing G. As with the two-layer model, the overshoot tachocline is much more unstable than the radiative tachocline. The e-folding growth times range from as short as 10 days to as long as several years, depending on latitude, G, and wavenumber. For a more realistic effective gravity that decreases linearly from the radiative interior to near zero at the top of the tachocline, we find that only m = 1, 2 modes are unstable, with growth rates somewhat larger than for constant G, with the same value as at the bottom of the tachocline. All results are the same whether we assume that the vertical velocity or the perturbation pressure is zero at the top of the layer; this is a direct consquence of not employing the geostrophic assumption for perturbations. We explain most of the properties of the instability in terms of the Rossby deformation radius. We discuss further improvements in the realism of the model, particularly adding toroidal fields that vary in height, and including latitudinal gradients of both rotation and toroidal fields.

  17. LETTER TO THE EDITOR: Diophantine integrability

    NASA Astrophysics Data System (ADS)

    Halburd, R. G.

    2005-04-01

    The heights of iterates of the discrete Painlevé equations over number fields appear to grow no faster than polynomials while the heights of generic solutions of non-integrable discrete equations grow exponentially. This gives rise to a simple and effective numerical test for the integrability of discrete equations. Numerical evidence and theoretical results are presented. Connections with other tests for integrability and Vojta's dictionary are discussed.

  18. On a Diophantine Equation of Stroeker

    DTIC Science & Technology

    2008-10-27

    and Fibonacci numbers. In fact, he showed that if N = Fk−2Fk−1, then (x, y) = (FkFk+1,−F 2k+1) (for k even) and (x, y) = (F 2k+1,−FkFk+1) (for k odd...Stroeker’s equation and Fibonacci numbers’, Fibonacci Quart. 26 (1988), 336–337. [5] J.M. Milne, Elliptic curves , 2006, BookSurge Publishers. [6] R. J

  19. Padé approximations and diophantine geometry

    PubMed Central

    Chudnovsky, D. V.; Chudnovsky, G. V.

    1985-01-01

    Using methods of Padé approximations we prove a converse to Eisenstein's theorem on the boundedness of denominators of coefficients in the expansion of an algebraic function, for classes of functions, parametrized by meromorphic functions. This result is applied to the Tate conjecture on the effective description of isogenies for elliptic curves. PMID:16593552

  20. Centaurs: Here, There, Everywhere!

    ERIC Educational Resources Information Center

    Dzlabenko, Dimitri; Ivril, Oleg

    2008-01-01

    Motivated by centaurs jumping around a circular stadium, we derive Kronecker's Approximation Theorem, which in turn provides elementary solutions to difficult problems in the theory of Diophantine approximations.

  1. XRF map identification problems based on a PDE electrodeposition model

    NASA Astrophysics Data System (ADS)

    Sgura, Ivonne; Bozzini, Benedetto

    2017-04-01

    In this paper we focus on the following map identification problem (MIP): given a morphochemical reaction–diffusion (RD) PDE system modeling an electrodepostion process, we look for a time t *, belonging to the transient dynamics and a set of parameters \\mathbf{p} , such that the PDE solution, for the morphology h≤ft(x,y,{{t}\\ast};\\mathbf{p}\\right) and for the chemistry θ ≤ft(x,y,{{t}\\ast};\\mathbf{p}\\right) approximates a given experimental map M *. Towards this aim, we introduce a numerical algorithm using singular value decomposition (SVD) and Frobenius norm to give a measure of error distance between experimental maps for h and θ and simulated solutions of the RD-PDE system on a fixed time integration interval. The technique proposed allows quantitative use of microspectroscopy images, such as XRF maps. Specifically, in this work we have modelled the morphology and manganese distributions of nanostructured components of innovative batteries and we have followed their changes resulting from ageing under operating conditions. The availability of quantitative information on space-time evolution of active materials in terms of model parameters will allow dramatic improvements in knowledge-based optimization of battery fabrication and operation.

  2. Problem Solving

    ERIC Educational Resources Information Center

    Kinsella, John J.

    1970-01-01

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

  3. Balance Problems

    MedlinePlus

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

  4. [Population problem, comprehension problem].

    PubMed

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

  5. Balance Problems

    MedlinePlus

    ... version of this page please turn Javascript on. Balance Problems About Balance Problems Have you ever felt dizzy, lightheaded, or ... dizziness problem during the past year. Why Good Balance is Important Having good balance means being able ...

  6. Walking Problems

    MedlinePlus

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

  7. Ear Problems

    MedlinePlus

    ... BMI Calculator myhealthfinder Immunization Schedules Nutrient Shortfall Questionnaire Ear ProblemsEar problems are often caused by an infection. However, other conditions may also cause ear pain or discomfort. Follow this chart for more ...

  8. Childbirth Problems

    MedlinePlus

    ... premature) labor, when labor starts before 37 completed weeks of pregnancy Problems with the umbilical cord Problems with the position of the baby, such as breech, in which the baby is going to come out feet first Birth injuries For some of these problems, the ...

  9. Mouth Problems

    MedlinePlus

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Mouth ProblemsMouth problems, such as sores, are very common. Follow this chart for more information about mouth problems in adults.Our trusted Symptom Checker is ...

  10. The Problems of Problem Solving

    ERIC Educational Resources Information Center

    Watson, Charles E.

    1976-01-01

    Discusses some common pitfalls in problem-solving and outlines three basic approaches to successfully identifying problems and their causes. (Available from Business Horizons, School of Business, Indiana University, Bloomington, Indiana 47401; $2.50, single copy) (Author/JG)

  11. Hopf and Frobenius algebras in conformal field theory

    NASA Astrophysics Data System (ADS)

    Singh, Sukreet

    With the current rapid depletion of non-renewable resources to generate power, energy conservation and on site generation have become the most critical aspects of the equation. Buildings should be so designed or retrofitted in order to generate its own electricity and cater to its own demand. This thesis looks as the ways in which we can do a post occupancy analysis of an existing institutional building of about 95,000 square feet that was built in 1960's in order to reduce usage and approach a Zero Net Energy goal. This case study building is Von Kleinsmid Centre (VKC) which is located at the heart of USC (University of Southern California). It is challenging to retrofit an existing institutional building because of its complexity and make it achieve a 'Zero Net Energy' goal. All the roadblocks, real life delays, software limitations that had to be overcome to achieve this result are explained in this thesis. The Zero Net Energy goal was achieved by calibrating energy model to the utility data of the building, providing various energy efficiency measures and generating on-site electricity.

  12. Joint Problems

    MedlinePlus

    ... Information Causes & Symptoms Diagnosis & Tests Care & Treatment Lifestyle & ... Facts & Information What are Joint Problems? Your musculoskeletal system is constructed of bones, muscles, and joints. The ...

  13. Popular Problems

    ERIC Educational Resources Information Center

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

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

  14. Speech Problems

    MedlinePlus

    ... and the respiratory system . The ability to understand language and produce speech is coordinated by the brain. So a person with brain damage from an accident, stroke, or birth defect may have speech and language problems. Some people with speech problems, particularly articulation ...

  15. Parking Problem

    ERIC Educational Resources Information Center

    Foster, Colin

    2012-01-01

    This is the story of a real problem, not a problem that is contrived, or invented for the convenience of the appropriate planning tool. This activity by a group of students, defined simply as "8FN", might be likened to an "end of term concert". If you just happened to be a delegate at the ATM Conference 2003 you might remember…

  16. Popular Problems

    ERIC Educational Resources Information Center

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

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

  17. Word Problems

    ERIC Educational Resources Information Center

    Fetrow, Jessica

    2009-01-01

    This study focused on how to help students translate word problems so that they understand how to solve them, and so they are successful with word problems. I have created three research questions to focus on during this research project. First, how will direct instruction of word meaning help clarify the operation needed, affect the achievement…

  18. Parking Problem

    ERIC Educational Resources Information Center

    Foster, Colin

    2012-01-01

    This is the story of a real problem, not a problem that is contrived, or invented for the convenience of the appropriate planning tool. This activity by a group of students, defined simply as "8FN", might be likened to an "end of term concert". If you just happened to be a delegate at the ATM Conference 2003 you might remember…

  19. Balance Problems

    MedlinePlus

    ... our e-newsletter! Aging & Health A to Z Balance Problems Basic Facts & Information What are Balance Problems? Having good balance means being able to ... Only then can you “keep your balance.” Why Balance is Important Your feelings of dizziness may last ...

  20. The temporal prior in bioelectromagnetic source imaging problems.

    PubMed

    Greensite, Fred

    2003-10-01

    The multiplicity of temporal priors proposed for regularization of the bioelectromagnetic source imaging problems [e.g., the inverse electrocardiogram (ECG) and inverse electroencephalogram (EEG) problems], is discordant with the fact that fundamental statistical principles sharply limit the choice. Thus, our objective is to derive the form of the prior consistent with the general unavailability of temporal constraints. Writing linear formulations of the inverse ECG and inverse EEG problems as H = FG + N (where the ith columns of matrices H, G, and N, are data, signal, and noise vectors at time step i, and F is the transfer matrix), and using the noninformative principle that features of the spatiotemporal prior not supplied a posteriori should be invariant under temporal transformations, we show that the implied spatiotemporal signal autocovariance matrix (of the vector formed by the entries of G) is given in block matrix form [equation in text] where Cg is a matrix of unit trace proportional to the autocovariance matrix of any column of G (representing supplied information regarding the spatial prior), epsilon[.] denotes expectation, superscript ' indicates transpose, [symbol in text] is the Kronecker product, [symbol in text] is Frobenius norm, and the "matrix scalar product" [symbol in text] indicates the inner product of the two vectors formed by the entries of the two adjacent matrices (i.e., A [symbol in text] B [triple bond] trace[A'B]). This result eliminates some uncertainties and ambiguities that have characterized spatiotemporal regularization methods--including eight methods previously introduced in this transactions. Ultimately, the result derives from an implied symmetry principle under which the form of a nontrivial noninformative temporal component of the prior can be identified. Among other things, separability of the spatiotemporal prior in terms of the above Kronecker product can be thought of as the expression of the lack of "entanglement" of

  1. Prostate Problems

    MedlinePlus

    ... do to help diagnose your prostate problem. Physical Exam A physical exam may help diagnose the cause ... sleep avoid or drink fewer liquids that have caffeine or alcohol in them avoid medicines that may ...

  2. Vision problems

    MedlinePlus

    ... which nothing can be seen) Vision loss and blindness are the most severe vision problems. Considerations Regular ... that look faded. The most common cause of blindness in people over age 60. Eye infection, inflammation, ...

  3. Sexual Problems

    MedlinePlus

    ... for a healthy life Mental health for men Sexual health for men Male infertility Prostate health Sexual problems ... updates. Enter email address Submit Home > Men's Health > Sexual health for men Men's Health This information in Spanish ( ...

  4. Speech Problems

    MedlinePlus

    ... thinking, but it becomes disorganized as they're speaking. So, someone who clutters may speak in bursts ... refuse to wait patiently for them to finish speaking. If you have a speech problem, it's fine ...

  5. Learning Problems

    MedlinePlus

    ... for you? Do you make spelling and other errors when you write? Are you having trouble with ... the truth is that learning problems are pretty common. And if your learning specialist or psychologist has ...

  6. Thyroid Problems

    MedlinePlus

    ... treated differently. Common thyroid disorders and problems include: Hypothyroidism Hypothyroidism is a disorder in which your thyroid doesn’ ... normal after you get better. If you have hypothyroidism, however, the levels of T4 in your blood ...

  7. Breathing Problems

    MedlinePlus

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

  8. Sleep Problems

    MedlinePlus

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

  9. The simplest problem in the collective dynamics of neural networks: is synchrony stable?

    NASA Astrophysics Data System (ADS)

    Timme, Marc; Wolf, Fred

    2008-07-01

    For spiking neural networks we consider the stability problem of global synchrony, arguably the simplest non-trivial collective dynamics in such networks. We find that even this simplest dynamical problem—local stability of synchrony—is non-trivial to solve and requires novel methods for its solution. In particular, the discrete mode of pulsed communication together with the complicated connectivity of neural interaction networks requires a non-standard approach. The dynamics in the vicinity of the synchronous state is determined by a multitude of linear operators, in contrast to a single stability matrix in conventional linear stability theory. This unusual property qualitatively depends on network topology and may be neglected for globally coupled homogeneous networks. For generic networks, however, the number of operators increases exponentially with the size of the network. We present methods to treat this multi-operator problem exactly. First, based on the Gershgorin and Perron-Frobenius theorems, we derive bounds on the eigenvalues that provide important information about the synchronization process but are not sufficient to establish the asymptotic stability or instability of the synchronous state. We then present a complete analysis of asymptotic stability for topologically strongly connected networks using simple graph-theoretical considerations. For inhibitory interactions between dissipative (leaky) oscillatory neurons the synchronous state is stable, independent of the parameters and the network connectivity. These results indicate that pulse-like interactions play a profound role in network dynamical systems, and in particular in the dynamics of biological synchronization, unless the coupling is homogeneous and all-to-all. The concepts introduced here are expected to also facilitate the exact analysis of more complicated dynamical network states, for instance the irregular balanced activity in cortical neural networks.

  10. Heat Problems.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…

  11. Puzzles & Problems.

    ERIC Educational Resources Information Center

    Murphy, Pat, Ed.

    1993-01-01

    "Exploring" is a magazine of science, art, and human perception, produced by Exploratorium in collaboration with other participating museums. This issue focuses on puzzles and problem solving. Brain teasers, puzzles, and the strategies for solving them are included. Features include: (1) "Homework Assignment #3" (Paul Doherty);…

  12. Efficiency Problems

    ERIC Educational Resources Information Center

    Willcutt, Bob

    1974-01-01

    Multibase arithmetic blocks are used to investigate the minimum number of blocks of each size to make a square of a given size in a given base. Generalizations are made to any size and any base through pattern recognition. The problem is extended to rectangles, cubes, and rectangular solids. (LS)

  13. Heat Problems.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…

  14. Hierarchi problem

    NASA Astrophysics Data System (ADS)

    Rubin, Sergey G.

    2016-02-01

    The way to solve the hierarchy problem based on multidimensional gravity is discussed. Various metrics of deformed extra space are produced at the Planck scale. It is shown that the Higgs vacuum value depends on a metric of extra space and hence their different numerical values are realized in various universes. An interval of the Higgs vacuum values is proved include zero value. Our universe belongs to a set of universes the vacuum values of which are close to zero

  15. Helicopter problems

    NASA Technical Reports Server (NTRS)

    Kussner, H G

    1937-01-01

    The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.

  16. Eigenvalue Problems.

    DTIC Science & Technology

    1987-06-01

    Vibration of an Elastic Bar We are interested in studying the small, longitudinal vibra- tions of a longitudinally loaded, elastically supported, elastic...u 2 + + 2u O(( m,Q Uk .(J- MO In the study of eigenvalue problems, central use will be made of Rellich’s theorem (cf. Agmon [19651), which states...H , where a > 0. Sufficient conditions for (4.2) - (4.4) to hold were given in Section 3; cf. (3.15) -(3.17). For the study of (4.1) it is useful to

  17. Sexual Problems in Men

    MedlinePlus

    Many men have sexual problems. They become more common as men age. Problems can include Erectile dysfunction Reduced or lost interest in sex ... problems may also be factors. Occasional problems with sexual function are common. If problems last more than ...

  18. Problem: Heart Valve Stenosis

    MedlinePlus

    ... valve . Learn about the different types of stenosis: Aortic stenosis Tricuspid stenosis Pulmonary stenosis Mitral stenosis Outlook for ... Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - ...

  19. Preventing Diabetes Problems

    MedlinePlus

    ... Other Dental Problems Diabetes & Sexual & Urologic Problems Preventing Diabetes Problems View or Print All Sections Heart Disease & ... prevent or delay sexual and urologic problems. Depression & Diabetes Depression is common among people with a chronic, ...

  20. Problems with "n"th-Term Problems

    ERIC Educational Resources Information Center

    Matteson, Shirley M.

    2010-01-01

    An nth-term problem involves a sequence. Students must determine which expression will allow them to calculate the nth position of the sequence. To solve such problems, students are to find "a rule that determines the number of elements in a step from the step number." These types of problems help students develop concepts of functions, variables,…

  1. Class and Home Problems: Optimization Problems

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  2. Class and Home Problems: Optimization Problems

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  3. Group problems in problem-based learning.

    PubMed

    Hendry, Graham D; Ryan, Greg; Harris, Jennifer

    2003-11-01

    Successful small-group learning in problem-based learning (PBL) educational programmes relies on functional group processes. However, there has been limited research on PBL group problems, and no studies have been conducted on problems as perceived by both students and tutors in the same educational context. The authors investigated PBL group problems in a graduate-entry medical programme, and report the most common group problems, and those that hinder students' learning the most. The possible causes of individual quietness and dominant behaviour, and potential influences that group problems may have on the tutorial process are summarized in an exploratory model of PBL group dysfunction that could be used to guide further research. Specifically, there is a need for further evidence on which to base guidelines for tutors and students to effectively manage group problems.

  4. Problems with Smell

    MedlinePlus

    ... this page please turn Javascript on. Problems with Smell About Problems with Smell Our sense of smell helps us enjoy life. ... sec Click to watch this video Aging and Smell Loss Problems with smell increase as people get ...

  5. The Chicken Problem.

    ERIC Educational Resources Information Center

    Reeves, Charles A.

    2000-01-01

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

  6. Problem? "No Problem!" Solving Technical Contradictions

    ERIC Educational Resources Information Center

    Kutz, K. Scott; Stefan, Victor

    2007-01-01

    TRIZ (pronounced TREES), the Russian acronym for the theory of inventive problem solving, enables a person to focus his attention on finding genuine, potential solutions in contrast to searching for ideas that "may" work through a happenstance way. It is a patent database-backed methodology that helps to reduce time spent on the problem,…

  7. Problem? "No Problem!" Solving Technical Contradictions

    ERIC Educational Resources Information Center

    Kutz, K. Scott; Stefan, Victor

    2007-01-01

    TRIZ (pronounced TREES), the Russian acronym for the theory of inventive problem solving, enables a person to focus his attention on finding genuine, potential solutions in contrast to searching for ideas that "may" work through a happenstance way. It is a patent database-backed methodology that helps to reduce time spent on the problem,…

  8. Diagnosing plant problems

    Treesearch

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  9. Quadratic eigenvalue problems.

    SciTech Connect

    Walsh, Timothy Francis; Day, David Minot

    2007-04-01

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

  10. Contemporary Story Problems.

    ERIC Educational Resources Information Center

    Miletich, Yvonne Petrich

    A collection of 90 contemporary mathematics story problems are presented for use by elementary teachers. The problems enable students to exercise the steps of problem solving involving operational skills. Instructions given to students list five directions for finding solutions. The answers to all 90 problems are included. This document is part of…

  11. PROBLEMS OF MIGRANT LABOR.

    ERIC Educational Resources Information Center

    WALLS, FOREST

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

  12. The Airlift Planning Problem

    DTIC Science & Technology

    2017-01-02

    papers. Our problem bears some resemblance to the ATFM problem in that routing decisions are somewhat similar to the scheduling decisions (what sequence...Problem (2) bears strong resemblance to problem (1); compare, for example, con- straint (2m) to constraint (1n). Despite this resemblance, the two problems...2000. D. Bertsimas, D. B. Brown , and C. Caramanis. Theory and applications of robust optimiza- tion. SIAM Review, 53(3):464–501, 2011a. D. Bertsimas

  13. [The mind -- body problem].

    PubMed

    Pérez, Diana I

    2005-01-01

    In this paper I present, in the first place, two of the main problems in the philosophy of mind: 1) the problem of the criteria of the mental, and 2) the problem of the relationship between the mental and the physical. In the last part, I mention two problems highly discussed nowadays which, in my view, will produce the most important advance in the knowledge of our minds in the next decades: the problem of consciousness and its neural basis, and the problem of the origin and development of a theory of mind.

  14. The Algorithm Selection Problem

    NASA Technical Reports Server (NTRS)

    Minton, Steve; Allen, John; Deiss, Ron (Technical Monitor)

    1994-01-01

    Work on NP-hard problems has shown that many instances of these theoretically computationally difficult problems are quite easy. The field has also shown that choosing the right algorithm for the problem can have a profound effect on the time needed to find a solution. However, to date there has been little work showing how to select the right algorithm for solving any particular problem. The paper refers to this as the algorithm selection problem. It describes some of the aspects that make this problem difficult, as well as proposes a technique for addressing it.

  15. IT Problem Management

    NASA Image and Video Library

    IT Problem Management – process responsible for managing Lifecycle of all IT problems. The primary objective is to prevent incidents from occurring and to minimize impact of incidents that cannot...

  16. Women and sexual problems

    MedlinePlus

    ... Ask you about your relationships, current sexual practices, attitude towards sex, other medical problems you might have, ... You and your partner may be referred for counseling to help with relationship problems or to work ...

  17. Side Effects: Sleep Problems

    Cancer.gov

    Sleep problems are a common side effect during cancer treatment. Find out how a polysomnogram can assess sleep problems. Learn about the benefits of managing sleep disorders in men and women with cancer.

  18. Menstrual Cycle Problems

    MedlinePlus

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Menstrual Cycle ProblemsFrom missed periods to painful periods, menstrual cycle problems are common, but usually not serious. Follow ...

  19. Puzzles Pastimes Problems.

    ERIC Educational Resources Information Center

    Eperson, D. B.

    1991-01-01

    This section includes eight problems to which the journal invites readers to respond. Problem topics include angles in alternate segments, pentominoes, a new triangle of numbers, cricket scores, symmetrical pentagons, inequalities, a pythagorean dissection, and magic squares. (MDH)

  20. Puzzles Pastimes Problems.

    ERIC Educational Resources Information Center

    Eperson, D. B.

    1991-01-01

    This section includes eight problems to which the journal invites readers to respond. Problem topics include angles in alternate segments, pentominoes, a new triangle of numbers, cricket scores, symmetrical pentagons, inequalities, a pythagorean dissection, and magic squares. (MDH)

  1. The molecular matching problem

    NASA Technical Reports Server (NTRS)

    Kincaid, Rex K.

    1993-01-01

    Molecular chemistry contains many difficult optimization problems that have begun to attract the attention of optimizers in the Operations Research community. Problems including protein folding, molecular conformation, molecular similarity, and molecular matching have been addressed. Minimum energy conformations for simple molecular structures such as water clusters, Lennard-Jones microclusters, and short polypeptides have dominated the literature to date. However, a variety of interesting problems exist and we focus here on a molecular structure matching (MSM) problem.

  2. Problems of Indian Children.

    ERIC Educational Resources Information Center

    Linton, Marigold

    Previous approaches to the learning problems of American Indian children are viewed as inadequate. An alternative is suggested which emphasizes the problem solution strategies which these children bring to the school situation. Solutions were analyzed in terms of: (1) their probability; (2) their efficiency at permitting a present problem to be…

  3. Exploratory Problems in Mathematics.

    ERIC Educational Resources Information Center

    Stevenson, Frederick W.

    This book attempts to introduce students to the creative aspects of mathematics through exploratory problems. The introduction presents the criteria for the selection of the problems in the book. Criteria indicate that problems should: be immediately attractive, require data to be generated or gathered, appeal to students from junior high school…

  4. Techniques of Problem Solving.

    ERIC Educational Resources Information Center

    Krantz, Steven G.

    The purpose of this book is to teach the basic principles of problem solving in both mathematical and non-mathematical problems. The major components of the book consist of learning to translate verbal discussion into analytical data, learning problem solving methods for attacking collections of analytical questions or data, and building a…

  5. Problems for Computer Mathematics.

    ERIC Educational Resources Information Center

    Allison, Ronald; And Others

    This booklet contains some 80 problems in mathematics suitable for computer solution. The problems range from very simple to complex. Problems have been included from most mathematic disciplines, including number theory, analytical geometry, probability and statistics, trigonometry, equations, and sequence and limits. For the most part these…

  6. Group Problem Solving.

    ERIC Educational Resources Information Center

    King, James C.

    1988-01-01

    This pamphlet discusses group problem solving in schools. Its point of departure is that teachers go at problems from a number of different directions and that principals need to capitalize on those differences and bring a whole range of skills and perceptions to the problem-solving process. Rather than trying to get everyone to think alike,…

  7. Techniques of Problem Solving.

    ERIC Educational Resources Information Center

    Krantz, Steven G.

    The purpose of this book is to teach the basic principles of problem solving in both mathematical and non-mathematical problems. The major components of the book consist of learning to translate verbal discussion into analytical data, learning problem solving methods for attacking collections of analytical questions or data, and building a…

  8. Problem Solving by Design

    ERIC Educational Resources Information Center

    Capobianco, Brenda M.; Tyrie, Nancy

    2009-01-01

    In a unique school-university partnership, methods students collaborated with fifth graders to use the engineering design process to build their problem-solving skills. By placing the problem in the context of a client having particular needs, the problem took on a real-world appeal that students found intriguing and inviting. In this article, the…

  9. Problem Solving by Design

    ERIC Educational Resources Information Center

    Capobianco, Brenda M.; Tyrie, Nancy

    2009-01-01

    In a unique school-university partnership, methods students collaborated with fifth graders to use the engineering design process to build their problem-solving skills. By placing the problem in the context of a client having particular needs, the problem took on a real-world appeal that students found intriguing and inviting. In this article, the…

  10. Exploratory Problems in Mathematics.

    ERIC Educational Resources Information Center

    Stevenson, Frederick W.

    This book attempts to introduce students to the creative aspects of mathematics through exploratory problems. The introduction presents the criteria for the selection of the problems in the book. Criteria indicate that problems should: be immediately attractive, require data to be generated or gathered, appeal to students from junior high school…

  11. Problem Solving. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2004-01-01

    No longer solely the domain of Mathematics, problem solving permeates every area of today's curricula. Ideally students are applying heuristics strategies in varied contexts and novel situations in every subject taught. The ability to solve problems is a basic life skill and is essential to understanding technical subjects. Problem-solving is a…

  12. Teaching Textbook Story Problems.

    ERIC Educational Resources Information Center

    LeBlanc, John F.

    1982-01-01

    Teaching story problems is seen to offer opportunities for developing the problem-solving process. Four steps described by George Polya are interpreted for the classroom as: (1) Tell, (2) Show, (3) Solve, and (4) Check. The teacher's role is detailed and the process is viewed to work for all problem types. (MP)

  13. Assessment Problems in Reading.

    ERIC Educational Resources Information Center

    MacGinitie, Walter H., Ed.

    The papers in this volume deal with a range of assessment problems in reading. The first paper, by Karlin, introduces the general problem of using assessment procedures to guide teaching. The next six papers deal with various aspects of this general problem. Otto discusses the distinction between norm-referenced, standardized achievement tests and…

  14. Problems of nonlinear deformation

    NASA Astrophysics Data System (ADS)

    Grigoliuk, E. I.; Shalashilin, V. I.

    A method of continuing the solution is discussed with respect to a parameter for a certain class of nonlinear problems in solid mechanics. Modifications of the method are developed in order to implement a unified continuation process at regular and limit points in the set of solutions, with extensions to nonlinear boundary value problems. Algorithms are developed for solving large deflection problems of elastic arches and large axisymmetric deflection problems for shells of revolution. In particular, the algorithms are used for the analysis of large deflections of circular arches and toroidal shells. Examples of natural vibration and stability problems for parallelograms and trapezoidal membranes and panels are given.

  15. Matrix interdiction problem

    SciTech Connect

    Pan, Feng; Kasiviswanathan, Shiva

    2010-01-01

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

  16. Expertise in Problem Solving.

    DTIC Science & Technology

    1981-05-18

    use at each step of the solution process. By contrast, both Issac and Newton contain separate representations of the same physics knowledge for each...representation. Issac . Issac by Gordon Novak (1977) is a program that can read the problem statement. It does this for statics problems only. The key feature of...problem does not generate an efficient solution. Newton . Newton by Johann de Kleer (1977) does not have any language translation facility. It solves

  17. The pear thrips problem

    Treesearch

    Bruce L. Parker

    1991-01-01

    As entomologists, we sometimes like to think of an insect pest problem as simply a problem with an insect and its host. Our jobs would be much easier if that were the case, but of course, it is never that simple. There are many other factors besides the insect, and each one must be fully considered to understand the problem and develop effective management solutions....

  18. Tactical missile turbulence problems

    NASA Technical Reports Server (NTRS)

    Dickson, Richard E.

    1987-01-01

    Of particular interest is atmospheric turbulence in the atmospheric boundary layer, since this affects both the launch and terminal phase of flight, and the total flight for direct fire systems. Brief discussions are presented on rocket artillery boost wind problems, mean wind correction, turbulent boost wind correction, the Dynamically Aimed Free Flight Rocket (DAFFR) wind filter, the DAFFR test, and rocket wake turbulence problems. It is concluded that many of the turbulence problems of rockets and missiles are common to those of aircraft, such as structural loading and control system design. However, these problems have not been solved at this time.

  19. [Hygiene problems in spas].

    PubMed

    Sacré, C

    1990-01-01

    The problems of hygiene to be tackled in spas are governed by Federal German legislation such as the Federal Communicable Diseases Act, the Federal German DIN standard regulation No. 19643, the guidelines for the construction of medical baths and the legal definition of a spa. The article describes the problems of hygiene encountered in respect of the water in swimming pools and in physical exercise basins in spas, as well as the problems of hygiene in other fields with particular reference to microorganisms that are of special importance as far as hygienic aspects are concerned. Reference is made to the trihalogen methanes and to the problems in connection with the employed materials.

  20. Known TCP Implementation Problems

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  1. On Euler's problem

    SciTech Connect

    Egorov, Yurii V

    2013-04-30

    We consider the classical problem on the tallest column which was posed by Euler in 1757. Bernoulli-Euler theory serves today as the basis for the design of high buildings. This problem is reduced to the problem of finding the potential for the Sturm-Liouville equation corresponding to the maximum of the first eigenvalue. The problem has been studied by many mathematicians but we give the first rigorous proof of the existence and uniqueness of the optimal column and we give new formulae which let us find it. Our method is based on a new approach consisting in the study of critical points of a related nonlinear functional. Bibliography: 6 titles.

  2. Identifying Adolescent Sleep Problems

    PubMed Central

    Short, Michelle A.; Gradisar, Michael; Gill, Jason; Camfferman, Danny

    2013-01-01

    Objectives To examine the efficacy of self-report and parental report of adolescent sleep problems and compare these findings to the incidence of adolescents who fulfill clinical criteria for a sleep problem. Sleep and daytime functioning factors that predict adolescents’ self-identification of a sleep problem will also be examined. Method 308 adolescents (aged 13–17 years) from eight socioeconomically diverse South Australian high schools participated in this study. Participants completed a survey battery during class time, followed by a 7-day Sleep Diary and the Flinders Fatigue Scale completed on the final day of the study. Parents completed a Sleep, Medical, Education and Family History Survey. Results The percentage of adolescents fulfilling one or more of the criteria for a sleep problem was inordinately high at 66%. Adolescent self-reporting a sleep problem was significantly lower than the adolescents who had one or more of the clinical criteria for a sleep problem (23.1% vs. 66.6%; χ2 = 17.46, p<.001). Parental report of their adolescent having a sleep problem was significantly lower than adolescent self-report (14.3% vs. 21.1%, p<.001). Adolescents who reported unrefreshing sleep were 4.81 times more likely to report a sleep problem. For every hour that bedtime was delayed, the odds of self-reporting a sleep problem increased by 1.91 times, while each additional 10 minutes taken to fall asleep increased the odds 1.40 times. Conclusion While many adolescents were found to have sleep patterns indicative of a sleep problem, only a third of this number self-identify having a sleep problem, while only a sixth of this number are indicated by parental report. This study highlights important features to target in future sleep education and intervention strategies for both adolescents and parents. PMID:24086501

  3. Strategies for Problem Solving.

    ERIC Educational Resources Information Center

    Karmos, Joseph S.; Karmos, Ann H.

    Problem-solving skills are becoming increasingly important in the workplace, and more schools are including them in the curriculum. Knowledge of problem solving will be critical to a work force that is dealing with advanced technology, yet many students have yet to master these skills. Based on this premise, this guide attempts to show how…

  4. A Stochastic Employment Problem

    ERIC Educational Resources Information Center

    Wu, Teng

    2013-01-01

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

  5. Problem Solving in Electricity.

    ERIC Educational Resources Information Center

    Caillot, Michel; Chalouhi, Elias

    Two studies were conducted to describe how students perform direct current (D-C) circuit problems. It was hypothesized that problem solving in the electricity domain depends largely on good visual processing of the circuit diagram and that this processing depends on the ability to recognize when two or more electrical components are in series or…

  6. The Problems of Dissection.

    ERIC Educational Resources Information Center

    Davis, Pat

    1997-01-01

    Describes some problems of classroom dissection including the cruelty that animals destined for the laboratory suffer. Discusses the multilevel approach that the National Anti-Vivisection Society (NAVS) has developed to address the problems of animal dissection such as offering a dissection hotline, exhibiting at science teacher conferences, and…

  7. Problem Solving in Electricity.

    ERIC Educational Resources Information Center

    Caillot, Michel; Chalouhi, Elias

    Two studies were conducted to describe how students perform direct current (D-C) circuit problems. It was hypothesized that problem solving in the electricity domain depends largely on good visual processing of the circuit diagram and that this processing depends on the ability to recognize when two or more electrical components are in series or…

  8. Teaching through Problem Solving

    ERIC Educational Resources Information Center

    Fi, Cos D.; Degner, Katherine M.

    2012-01-01

    Teaching through Problem Solving (TtPS) is an effective way to teach mathematics "for" understanding. It also provides students with a way to learn mathematics "with" understanding. In this article, the authors present a definition of what it means to teach through problem solving. They also describe a professional development vignette that…

  9. [Ethical problems in perinatology].

    PubMed

    Koppe, J G

    1989-08-01

    Ethical problems in the neonatal period and in the unborn baby are discussed. The different categories of babies where ethical problems arise are summarized and ethical values, reasons for justification and the question of who decides are discussed. Medical strategies nowadays used in different countries are presented and a procedure is described how to make a decision to stop or not to start treatment.

  10. GREECE--SELECTED PROBLEMS.

    ERIC Educational Resources Information Center

    MARTONFFY, ANDREA PONTECORVO; AND OTHERS

    A CURRICULUM GUIDE IS PRESENTED FOR A 10-WEEK STUDY OF ANCIENT GREEK CIVILIZATION AT THE 10TH-GRADE LEVEL. TEACHING MATERIALS FOR THE UNIT INCLUDE (1) PRIMARY AND SECONDARY SOURCES DEALING WITH THE PERIOD FROM THE BRONZE AGE THROUGH THE HELLENISTIC PERIOD, (2) GEOGRAPHY PROBLEMS, AND (3) CULTURAL MODEL PROBLEM EXERCISES. THOSE CONCEPTS WITH WHICH…

  11. Problem-Based Learning

    ERIC Educational Resources Information Center

    Allen, Deborah E.; Donham, Richard S.; Bernhardt, Stephen A.

    2011-01-01

    In problem-based learning (PBL), students working in collaborative groups learn by resolving complex, realistic problems under the guidance of faculty. There is some evidence of PBL effectiveness in medical school settings where it began, and there are numerous accounts of PBL implementation in various undergraduate contexts, replete with…

  12. The Problems of Dissection.

    ERIC Educational Resources Information Center

    Davis, Pat

    1997-01-01

    Describes some problems of classroom dissection including the cruelty that animals destined for the laboratory suffer. Discusses the multilevel approach that the National Anti-Vivisection Society (NAVS) has developed to address the problems of animal dissection such as offering a dissection hotline, exhibiting at science teacher conferences, and…

  13. Convection dominated problems

    NASA Technical Reports Server (NTRS)

    Peraire, J.; Morgan, K.; Zienkiewicz, O. C.

    1986-01-01

    The paper surveys the last ten years of activity of the INME Swansea, dealing with problems of convection dominated flow. The basic explicit/implicit characteristic Galerkin process and its application to adaptive mesh refinement used in the solution of realistic problems is focused on.

  14. The Problem of Meaning.

    ERIC Educational Resources Information Center

    Barrell, Arthur Rex

    1970-01-01

    The study of semantics, the study of meaning, promises more complete communicative thought transfer if several problem areas can be solved or at least generally agreed upon. The problem of exact definition of words arises from the fact that no one work is the exact equivalent of another. However, the study of many languages forces the mind to…

  15. Problems in baryon spectroscopy

    SciTech Connect

    Capstick, S.

    1994-04-01

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

  16. Wicked Problems: Inescapable Wickedity

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  17. Visual Channel Problems.

    ERIC Educational Resources Information Center

    Mann, Philip H.; Suiter, Patricia A.

    This teacher training module classifies visual channel problems into the following four main areas: visual perception, revisualization (memory), visual-motor (eye-hand coordination), and ocular-motor tasks. Specific deficits are listed under these main headings, behaviors are given to help identify the problem, and ways to improve the condition…

  18. Inquiry and Problem Solving.

    ERIC Educational Resources Information Center

    Thorson, Annette, Ed.

    1999-01-01

    This issue of ENC Focus focuses on the topic of inquiry and problem solving. Featured articles include: (1) "Inquiry in the Everyday World of Schools" (Ronald D. Anderson); (2) "In the Cascade Reservoir Restoration Project Students Tackle Real-World Problems" (Clint Kennedy with Advanced Biology Students from Cascade High…

  19. Student-Posed Problems

    NASA Astrophysics Data System (ADS)

    Harper, Kathleen A.; Etkina, Eugenia

    2002-10-01

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

  20. Modern Problems. Grade 12.

    ERIC Educational Resources Information Center

    Wilmington Public Schools, DE.

    The general purpose of the twelfth grade course is to help the student assume his role as a decision-maker in a democratic society. The nature and complexity of contemporary problems are examined using this guide to enable the student: 1) to analyze alternative solutions to these problems; 2) to develop attitudes and values appropriate to a…

  1. Problems and Solutions.

    ERIC Educational Resources Information Center

    NatureScope, 1989

    1989-01-01

    Examines some of the reasons tropical rain forests are being destroyed and ways people are working to protect these forests. Provides activities on how people can help, reason for saving the forests, individual actions related to forest problems and solutions, and issues and problems. Three copyable pages accompany activities. (Author/RT)

  2. Programming and Problem Solving.

    ERIC Educational Resources Information Center

    Elias, Barbara P.

    A study was conducted to examine computer programming as a problem solving activity. Thirteen fifth grade children were selected by their teacher from an above average class to use Apple IIe microcomputers. The investigator conducted sessions of 40-50 minutes with the children in groups of two or three. Four problems, incorporating the programming…

  3. Problem Solving and Intelligence.

    ERIC Educational Resources Information Center

    Resnick, Lauren B.; Glaser, Robert

    This paper argues that a major aspect of intelligence is the ability to solve problems and that careful analysis of problem-solving behavior is a means of specifying many of the psychological processes that make up intelligence. The focus is on the mechanisms involved when, in the absence of complete instruction, a person must "invent" a new…

  4. Problem-Based Learning

    ERIC Educational Resources Information Center

    Allen, Deborah E.; Donham, Richard S.; Bernhardt, Stephen A.

    2011-01-01

    In problem-based learning (PBL), students working in collaborative groups learn by resolving complex, realistic problems under the guidance of faculty. There is some evidence of PBL effectiveness in medical school settings where it began, and there are numerous accounts of PBL implementation in various undergraduate contexts, replete with…

  5. TOCFL: Problems and Guidelines.

    ERIC Educational Resources Information Center

    Weiping, Wu

    Problems in the testing of Chinese as a foreign language (CFL) are examined, focusing on proficiency testing needs and test standardization. Particular attention is paid to listening and reading assessment. The first part of the discussion looks at specific problems with five existing proficiency tests, including such aspects as inadequacy of the…

  6. Managing Student Behavior Problems.

    ERIC Educational Resources Information Center

    Duke, Daniel Linden; Meckel, Adrienne Maravich

    Written primarily for teachers and educators, school administrators and personnel, policy makers, and parents, this book discusses the alternative control procedures available to educators faced with student behavior problems and presents one set--those related to problem management--as most effective. The authors' Systematic Management Plan for…

  7. A Stochastic Employment Problem

    ERIC Educational Resources Information Center

    Wu, Teng

    2013-01-01

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

  8. Current Social Problem Novels.

    ERIC Educational Resources Information Center

    Kenney, Donald J.

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

  9. ILLITERACY, A WORLD PROBLEM.

    ERIC Educational Resources Information Center

    JEFFRIES, CHARLES

    THIS STUDY OF WORLD ILLITERACY BEGINS WITH A BRIEF OUTLINE OF THE NATURE OF THE PROBLEM OF ILLITERACY AND DISCUSSION OF THE SPECIAL TECHNIQUES WHICH HAVE BEEN EVOLVED TO OVERCOME IT. A WORLD MAP OF ILLITERACY PLOTS ILLITERACY IN SPECIFIC AREAS AND COUNTRIES. PAST AND PRESENT EFFORTS TO SOLVE THE PROBLEM (THE PIONEER WORK OF WORK OF MISSIONARIES,…

  10. Problem Solving Techniques Seminar.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

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

  11. California's Water Problems.

    ERIC Educational Resources Information Center

    Wheatley, Judy; Sudman, Rita Schmidt, Ed.

    This packet of instructional materials is designed to give social science students in grades 6-9 a first-hand experience in working out solutions to real-life problems involving the management of California's water. Students work in groups on one of three problems presented in the packet: (1) the management of the Sacramento-San Joaquin Delta that…

  12. Stabilization of Kepler's problem

    NASA Technical Reports Server (NTRS)

    Stokes, A.

    1977-01-01

    A regularization of Kepler's problem due to Moser (1970) is used to stabilize the equations of motion. In other words, a particular solution of Kepler's problem is imbedded in a Liapunov stable system. Perturbations can be introduced into the stabilized equations.

  13. Problems Facing Rural Schools.

    ERIC Educational Resources Information Center

    Stewart, C. E.; And Others

    Problems facing rural Scottish schools range from short term consideration of daily operation to long term consideration of organizational alternatives. Addressed specifically, such problems include consideration of: (1) liaison between a secondary school and its feeder primary schools; (2) preservice teacher training for work in small, isolated…

  14. Environmental problem solving

    SciTech Connect

    Miller, A.

    1999-06-01

    Human influences create both environmental problems and barriers to effective policy aimed at addressing those problems. In effect, environmental managers manage people as much as they manage the environment. Therefore, they must gain an understanding of the psychological and sociopolitical dimensions of environmental problems that they are attempting to resolve. The author reappraises conventional analyses of environmental problems using lessons from the psychosocial disciplines. The author combines the disciplines of ecology, political sociology and psychology to produce a more adaptive approach to problem-solving that is specifically geared toward the environmental field. Numerous case studies demonstrate the practical application of theory in a way that is useful to technical and scientific professionals as well as to policymakers and planners.

  15. The Guderley problem revisited

    SciTech Connect

    Ramsey, Scott D; Kamm, James R; Bolstad, John H

    2009-01-01

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

  16. Problem Solving and Learning

    NASA Astrophysics Data System (ADS)

    Singh, Chandralekha

    2009-07-01

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

  17. Problem Solving Does Not Have To Be a Problem.

    ERIC Educational Resources Information Center

    Barb, Cynthia; Quinn, Anne Larson

    1997-01-01

    Highlights the argument that states that problem solving is much more than just solving problems, by focusing on problem-solving history, George Polya's view of problem solving, Asians' successful use of multiple intuitive solutions, and other examples. (ASK)

  18. The Design of Low Order Controllers Using the Frobenius-Hankel Norm

    DTIC Science & Technology

    1990-04-01

    Engineering in the Graduate College of the University of Illinois at Urbana-Champaign, 1990 Acceso ’, For NTIS CRA&I DTIC TAB - U-1nnojnced 0...structures including lightly damped modes, decentralized structure and multiple controls and measurements. This structure has also been studied in [28] and

  19. Group assignment problem

    NASA Astrophysics Data System (ADS)

    Poore, Aubrey B.; Gadaleta, Sabino

    2003-12-01

    Multiple frame data association, whether it is based on multiple hypothesis tracking or multi-dimensional assignment problems, has established itself as the method of choice for difficult tracking problems, principally due to the ability to hold difficult data association decisions in abeyance until additional information is available. Over the last twenty years, these methods have focused on one-to-one assignments, many-to-one, and many-to-many assignments. Group tracking, on the other hand, introduces new complexity into the association process, especially if some soft decision making capability is desired. Thus, the goal of this work is to combine multiple grouping hypotheses for each frame of data (tracks or measurements) with matching these hypotheses across multiple frames of data using one-to-one, many-to-one, or many-to-many assignments to determine the correct hypothesis on each frame of data and connectivity across the frames. The resulting formulation is sufficiently general to cover four broad classes of problems in multiple target tracking, namely (a) group cluster tracking, (b) pixel (clump) IR cluster tracking, (c) the merged measurement problem, and (d) MHT for track-to-track fusion. What is more, the cluster assignment problem for either two or multiple dimensions represents a generalized data association problem in the sense that it reduces to the classical assignment problems when there are no overlapping groups or clusters. The formulation of the assignment problem for resolved object tracking and candidate group methods for use in multiple frame group tracking are briefly reviewed. Then, three different formulations of the group assignment problem are developed.

  20. Group assignment problem

    NASA Astrophysics Data System (ADS)

    Poore, Aubrey B.; Gadaleta, Sabino

    2004-01-01

    Multiple frame data association, whether it is based on multiple hypothesis tracking or multi-dimensional assignment problems, has established itself as the method of choice for difficult tracking problems, principally due to the ability to hold difficult data association decisions in abeyance until additional information is available. Over the last twenty years, these methods have focused on one-to-one assignments, many-to-one, and many-to-many assignments. Group tracking, on the other hand, introduces new complexity into the association process, especially if some soft decision making capability is desired. Thus, the goal of this work is to combine multiple grouping hypotheses for each frame of data (tracks or measurements) with matching these hypotheses across multiple frames of data using one-to-one, many-to-one, or many-to-many assignments to determine the correct hypothesis on each frame of data and connectivity across the frames. The resulting formulation is sufficiently general to cover four broad classes of problems in multiple target tracking, namely (a) group cluster tracking, (b) pixel (clump) IR cluster tracking, (c) the merged measurement problem, and (d) MHT for track-to-track fusion. What is more, the cluster assignment problem for either two or multiple dimensions represents a generalized data association problem in the sense that it reduces to the classical assignment problems when there are no overlapping groups or clusters. The formulation of the assignment problem for resolved object tracking and candidate group methods for use in multiple frame group tracking are briefly reviewed. Then, three different formulations of the group assignment problem are developed.

  1. Problem-Solving Software

    NASA Technical Reports Server (NTRS)

    1992-01-01

    CBR Express software solves problems by adapting sorted solutions to new problems specified by a user. It is applicable to a wide range of situations. The technology was originally developed by Inference Corporation for Johnson Space Center's Advanced Software Development Workstation. The project focused on the reuse of software designs, and Inference used CBR as part of the ACCESS prototype software. The commercial CBR Express is used as a "help desk" for customer support, enabling reuse of existing information when necessary. It has been adopted by several companies, among them American Airlines, which uses it to solve reservation system software problems.

  2. Astronauts' menu problem.

    NASA Technical Reports Server (NTRS)

    Lesso, W. G.; Kenyon, E.

    1972-01-01

    Consideration of the problems involved in choosing appropriate menus for astronauts carrying out SKYLAB missions lasting up to eight weeks. The problem of planning balanced menus on the basis of prepackaged food items within limitations on the intake of calories, protein, and certain elements is noted, as well as a number of other restrictions of both physical and arbitrary nature. The tailoring of a set of menus for each astronaut on the basis of subjective rankings of each food by the astronaut in terms of a 'measure of pleasure' is described, and a computer solution to this problem by means of a mixed integer programming code is presented.

  3. Overcoming breastfeeding problems

    MedlinePlus

    Plugged milk ducts; Nipple soreness when breastfeeding; Breastfeeding - overcoming problems; Let-down reflex ... Breastfeeding (nursing) your baby can be a good experience for both the mother and the baby. It ...

  4. Diabetic Eye Problems

    MedlinePlus

    ... too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It ... light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. ...

  5. The cosmological constant problem

    SciTech Connect

    Dolgov, A.D.

    1989-05-01

    A review of the cosmological term problem is presented. Baby universe model and the compensating field model are discussed. The importance of more accurate data on the Hubble constant and the Universe age is stressed. 18 refs.

  6. Gait or Walking Problems

    MedlinePlus

    Gait or Walking Problems the basic facts multiple sclerosis Many people with MS will experience difficulty with walking, which is also called ambulation. The term “gait” refers more specifically to the manner ...

  7. The Pesticide Problem.

    ERIC Educational Resources Information Center

    Bosch, Van Den Robert

    1979-01-01

    Contains a discussion of insects' ability to survive, of the development of pesticides and the introduction of DDT, of the problems of pesticide use and resistance to insecticides, and of the advantages of integrated pest control. (BB)

  8. The root extraction problem

    NASA Astrophysics Data System (ADS)

    Rousseau, C.

    The Nth root extraction problem for germs of diffeomorphisms f :(C,0)→(C,0) is the problem of finding a germ of diffeomorphism g :(C,0)→(C,0) such that g=f, where g is the Nth iterate of g under composition. Depending on f and on the multiplier of g at the origin there can be formal and analytic obstructions to a solution of the problem. By considering an unfolding of f we explain these obstructions. Indeed each analytic obstruction corresponds to an accumulation of periodic points which, in turn, are an obstruction to taking an Nth root of the unfolding. We apply this to the problem of the section of a curvilinear angle in N equal parts in conformal geometry.

  9. STAGS Example Problems Manual

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Rankin, Charles C.

    2006-01-01

    This document summarizes the STructural Analysis of General Shells (STAGS) development effort, STAGS performance for selected demonstration problems, and STAGS application problems illustrating selected advanced features available in the STAGS Version 5.0. Each problem is discussed including selected background information and reference solutions when available. The modeling and solution approach for each problem is described and illustrated. Numerical results are presented and compared with reference solutions, test data, and/or results obtained from mesh refinement studies. These solutions provide an indication of the overall capabilities of the STAGS nonlinear finite element analysis tool and provide users with representative cases, including input files, to explore these capabilities that may then be tailored to other applications.

  10. The Pesticide Problem.

    ERIC Educational Resources Information Center

    Bosch, Van Den Robert

    1979-01-01

    Contains a discussion of insects' ability to survive, of the development of pesticides and the introduction of DDT, of the problems of pesticide use and resistance to insecticides, and of the advantages of integrated pest control. (BB)

  11. Contemporary Problems in Africa.

    ERIC Educational Resources Information Center

    O'Meara, Patrick; Winchester, N. Brian

    1987-01-01

    Provides a brief overview of political and economic developments of the past 25 years in Africa. Maintains this was a period of experimentation with vast differences in the ways in which governments dealt with human and natural problems. (JDH)

  12. The Problem of Heroin

    ERIC Educational Resources Information Center

    Wilson, James Q.; And Others

    1972-01-01

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

  13. Enuresis: A Social Problem.

    ERIC Educational Resources Information Center

    McDonald, James E.

    1978-01-01

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

  14. Word Problems Made Painless.

    ERIC Educational Resources Information Center

    Noddings, Nel

    1980-01-01

    Computer assisted instruction is presented as a tool for helping students learn to successfully solve word problems. Four stages of developing a curriculum for elementary school mathematics, grades three through six, are covered. (MP)

  15. Conceptualizing Mathematics "Motion Problems"

    ERIC Educational Resources Information Center

    McKeough, William J.

    1970-01-01

    Describes an instructional method in secondary school mathematics applicable to physics instruction, to develop conceptual understanding of motion word problems. Distance, rate, and time are defined, used as variables and considered with relative motion as a unifying concept. (JM)

  16. Diabetes and Foot Problems

    MedlinePlus

    ... Infographic (English) Low Blood Glucose (Hypoglycemia) Nerve Damage (Diabetic Neuropathies) Diabetic Kidney Disease Diabetes and Foot Problems Diabetic ... time, diabetes may cause nerve damage, also called diabetic neuropathy , that can cause tingling and pain, and can ...

  17. Breathing Problems - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Breathing Problems URL of this page: https://medlineplus.gov/languages/breathingproblems.html Other topics A-Z Expand Section ...

  18. Mouth Problems and HIV

    MedlinePlus

    ... orientation. This information is for people who have mouth (oral) problems related to HIV infection. It explains ... look like. It also describes where in the mouth they occur and how they are treated. They ...

  19. Adaptive Problem Solving

    DTIC Science & Technology

    2017-03-01

    Auckland Private Bag 92019 Auckland, 1142 New Zealand Name of Principal Investigators (Co-PI): Patricia J. Riddle - e-mail address : pat...Auckland, 1142 New Zealand Period of Performance: 5/27/2015 – 11/26/2016 Abstract: We have implemented a system, MSP, that given a specific problem...since 2014. Thus, we cannot compare MSP against a new set of competitors on a new set of problems. However, we can compare it against RIDA* on the

  20. Network problem threshold

    NASA Technical Reports Server (NTRS)

    Gejji, Raghvendra, R.

    1992-01-01

    Network transmission errors such as collisions, CRC errors, misalignment, etc. are statistical in nature. Although errors can vary randomly, a high level of errors does indicate specific network problems, e.g. equipment failure. In this project, we have studied the random nature of collisions theoretically as well as by gathering statistics, and established a numerical threshold above which a network problem is indicated with high probability.

  1. The basketball problem

    NASA Astrophysics Data System (ADS)

    Schröer, H.

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

  2. Bicriteria network design problems

    SciTech Connect

    Marathe, M.V.; Ravi, R.; Sundaram, R.; Ravi, S.S.; Rosenkrantz, D.J.; Hunt, H.B. III

    1997-11-20

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

  3. Toward Solving the Problem of Problem Solving: An Analysis Framework

    ERIC Educational Resources Information Center

    Roesler, Rebecca A.

    2016-01-01

    Teaching is replete with problem solving. Problem solving as a skill, however, is seldom addressed directly within music teacher education curricula, and research in music education has not examined problem solving systematically. A framework detailing problem-solving component skills would provide a needed foundation. I observed problem solving…

  4. Toward Solving the Problem of Problem Solving: An Analysis Framework

    ERIC Educational Resources Information Center

    Roesler, Rebecca A.

    2016-01-01

    Teaching is replete with problem solving. Problem solving as a skill, however, is seldom addressed directly within music teacher education curricula, and research in music education has not examined problem solving systematically. A framework detailing problem-solving component skills would provide a needed foundation. I observed problem solving…

  5. The Vector Decomposition Problem

    NASA Astrophysics Data System (ADS)

    Yoshida, Maki; Mitsunari, Shigeo; Fujiwara, Toru

    This paper introduces a new computational problem on a two-dimensional vector space, called the vector decomposition problem (VDP), which is mainly defined for designing cryptosystems using pairings on elliptic curves. We first show a relation between the VDP and the computational Diffie-Hellman problem (CDH). Specifically, we present a sufficient condition for the VDP on a two-dimensional vector space to be at least as hard as the CDH on a one-dimensional subspace. We also present a sufficient condition for the VDP with a fixed basis to have a trapdoor. We then give an example of vector spaces which satisfy both sufficient conditions and on which the CDH is assumed to be hard in previous work. In this sense, the intractability of the VDP is a reasonable assumption as that of the CDH.

  6. Global geochemical problems

    NASA Technical Reports Server (NTRS)

    Harriss, R. C.

    1980-01-01

    Application of remote sensing techniques to the solution of geochemical problems is considered with emphasis on the 'carbon-cycle'. The problem of carbon dioxide sinks and the areal extent of coral reefs are treated. In order to assess the problems cited it is suggested that remote sensing techniques be utilized to: (1)monitor globally the carbonate and bicarbonate concentrations in surface waters of the world ocean; (2)monitor the freshwater and oceanic biomass and associated dissolved organic carbon; (3) inventory the coral reef areas and types and the associated oceanographic climatic conditions; and (4)measure the heavy metal fluxes from forested and vegetated areas, from volcanos, from different types of crustal rocks, from soils, and from sea surfaces.

  7. Freon: An unsuspected problem

    SciTech Connect

    Voge, V.M. )

    1989-10-01

    Freon 113 is not usually considered a toxic chemical and is not generally included in toxicology text lists of dangerous chemicals. However, during one 7-year period, the U.S. Navy recorded 38 freon-related mishaps, including 16 chemical burns and 22 inhalation injuries. Several deaths were also recorded. Part of the problem seems to be that freon compounds are excellent degreasing and cleaning agents. Consequently, they are widely and inappropriately used by aviation ground crews for this purpose. Such use usually presents no problem, except when the agent is used in small, closed, unventilated areas. This paper outlines the properties of freon that make it dangerous in the aviation community, some case histories of freon-related mishaps, what the Navy has done to control or prevent the problem from recurring, and the Navy's relative success with its prevention policies.

  8. The Thinnest Path Problem

    DTIC Science & Technology

    2016-07-22

    single source to all other nodes in the network do not form a tree . In other words, the thinnest path to a node does not necessarily go through the...thinnest path to any of its neighbors. The loss of the tree structure is one of the main reasons that the thinnest path problem is much more complex than...path (referred to as the secluded path in [6]) and the thinnest Steiner tree in graphs. They showed that the problem in a general graph is NP-complete

  9. Inverse heat conduction problems

    NASA Astrophysics Data System (ADS)

    Orlande, Helcio Rangel Barreto

    We present the solution of the following inverse problems: (1) Inverse Problem of Estimating Interface Conductance Between Periodically Contacting Surfaces; (2) Inverse Problem of Estimating Interface Conductance During Solidification via Conjugate Gradient Method; (3) Determination of the Reaction Function in a Reaction-Diffusion Parabolic Problem; and (4) Simultaneous Estimation of Thermal Diffusivity and Relaxation Time with Hyperbolic Heat Conduction Model. Also, we present the solution of a direct problem entitled: Transient Thermal Constriction Resistance in a Finite Heat Flux Tube. The Conjugate Gradient Method with Adjoint Equation was used in chapters 1-3. The more general function estimation approach was treated in these chapters. In chapter 1, we solve the inverse problem of estimating the timewise variation of the interface conductance between periodically contacting solids, under quasi-steady-state conditions. The present method is found to be more accurate than the B-Spline approach for situations involving small periods, which are the most difficult on which to perform the inverse analysis. In chapter 2, we estimate the timewise variation of the interface conductance between casting and mold during the solidification of aluminum. The experimental apparatus used in this study is described. In chapter 3, we present the estimation of the reaction function in a one dimensional parabolic problem. A comparison of the present function estimation approach with the parameter estimation technique, wing B-Splines to approximate the reaction function, revealed that the use of function estimation reduces the computer time requirements. In chapter 4 we present a finite difference solution for the transient constriction resistance in a cylinder of finite length with a circular contact surface. A numerical grid generation scheme was used to concentrate grid points in the regions of high temperature gradients in order to reduce discretization errors. In chapter 6, we

  10. The Sedov Test Problem

    SciTech Connect

    Fung, Jimmy; Masser, Thomas; Morgan, Nathaniel R.

    2012-06-25

    The Sedov test is classically defined as a point blast problem. The Sedov problem has led us to advances in algorithms and in their understanding. Vorticity generation can be physical or numerical. Both play a role in Sedov calculations. The RAGE code (Eulerian) resolves the shock well, but produces vorticity. The source definition matters. For the FLAG code (Lagrange), CCH is superior to SGH by avoiding spurious vorticity generation. FLAG SGH currently has a number of options that improve results over traditional settings. Vorticity production, not shock capture, has driven the Sedov work. We are pursuing treatments with respect to the hydro discretization as well as to artificial viscosity.

  11. Problem of Jerusalem.

    DTIC Science & Technology

    1985-12-16

    lllllosomo 112m 02. 11k1 __ 12U ’ S .......... MI(CROCOPY RESOLUION~ TEST CHART 1. - A 0K FILE OLMIY -- The views expressed in this paper ae those of...open publication until 00 it has been cleared by the appropriate mt0tay seice or S government agency. I * PROBLEM OF JERUSALEM BY LIEUTENANT COLONEL ALAN...COVERED Problem of Jerusalem Student Essay 6. PERFORMING ORG. REPORT NMBER 7 A THOR( s ) 8. CONTRACT OR GRANT NUMBER( s ) Alan H. Sherman 9. PERFORMING

  12. Hydrodynamic test problems

    SciTech Connect

    Moran, B

    2005-06-02

    We present test problems that can be used to check the hydrodynamic implementation in computer codes designed to model the implosion of a National Ignition Facility (NIF) capsule. The problems are simplified, yet one of them is three-dimensional. It consists of a nearly-spherical incompressible imploding shell subjected to an exponentially decaying pressure on its outer surface. We present a semi-analytic solution for the time-evolution of that shell with arbitrary small three-dimensional perturbations on its inner and outer surfaces. The perturbations on the shell surfaces are intended to model the imperfections that are created during capsule manufacturing.

  13. Inverse problems in mathematical physics

    NASA Astrophysics Data System (ADS)

    Glasko, V. B.

    Procedures for the correct formulation and solution of inverse problems, which usually belong to the class of ill-posed problems, are discussed. Attention is given to the concept of the conditionally correct statement of a problem, the concept of quasi-solution, and the fundamentals of regularization theory. The discussion also covers the uniqueness of solutions to inverse problems in mathematical physics, with consideration given to problems involving layered media, impedance problems, gravimetric problems, and inverse problems of heat conduction. The problem of stability and regularizing operators are also discussed.

  14. The real problem.

    PubMed

    Godfrey, M

    1997-01-01

    I really was dismayed to see the basic cause of all our planet's problems buried in the September/October 96 issue: "...religious zealots might wreck the family planning needs of a billion people...." Let's face hard facts: all these problems would go away if the planet's population were small enough. What we really need to establish is what the population of the earth should be, and then set out to achieve that population as soon as possible. All of our efforts to reduce automobile pollution, the amount of reactor waste, the number of species being obliterated, etc., are just postponing the inevitable. What we need to look at, and keep track of, are those factors that encourage expanding population and discourage population control. For example, most businesses like to see the population expand so they can have a growing customer base. I truly appreciate your efforts. But if we are going to get anywhere we have to clearly identify the real problem. And then we have to break it down into manageable pieces and go to work on them. Otherwise we are going to keep looking at the graphs and wringing our hands as this accumulation of problems builds until it sweeps over us like a giant tsunami.

  15. Problem Patron Manual.

    ERIC Educational Resources Information Center

    Brown, Marion, Comp.; And Others

    This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…

  16. Problem Classification in Counseling.

    ERIC Educational Resources Information Center

    Klimes, Rudolf E.

    1992-01-01

    This paper describes a framework for counselors that will help them classify personal and social problems of clients for base-line and end-line comparisons. Counseling's goal, as presented here, is to help individuals for a lifetime; therapy is not seen as the giving of advice or solutions, but as a teaching process through which clients become…

  17. Problem: Mitral Valve Regurgitation

    MedlinePlus

    ... Stroke Vascular Health Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Problem: Mitral Valve Regurgitation Updated:Sep 21,2016 What is mitral valve ... blood flows from the ventricle through the aortic valve — as it should — and some blood flows ...

  18. Unfolding a Problem

    ERIC Educational Resources Information Center

    Currier, Sarah Cox

    2015-01-01

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

  19. Introspection in Problem Solving

    ERIC Educational Resources Information Center

    Jäkel, Frank; Schreiber, Cornell

    2013-01-01

    Problem solving research has encountered an impasse. Since the seminal work of Newell und Simon (1972) researchers do not seem to have made much theoretical progress (Batchelder and Alexander, 2012; Ohlsson, 2012). In this paper we argue that one factor that is holding back the field is the widespread rejection of introspection among cognitive…

  20. Problem Patron Manual.

    ERIC Educational Resources Information Center

    Brown, Marion, Comp.; And Others

    This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…

  1. Environmental Health Problems.

    ERIC Educational Resources Information Center

    Environmental Health Service (DHEW/PHS), Rockville, MD.

    Aimed at a society which is forced to make decisions relative to their total environment, this pamphlet discusses a few of the problems associated with restoring and maintaining an environmental relationship conducive to the health and well-being of man. The topics covered include: air pollution, noise, solid waste, the urban environment, drinking…

  2. Solving Common Mathematical Problems

    NASA Technical Reports Server (NTRS)

    Luz, Paul L.

    2005-01-01

    Mathematical Solutions Toolset is a collection of five software programs that rapidly solve some common mathematical problems. The programs consist of a set of Microsoft Excel worksheets. The programs provide for entry of input data and display of output data in a user-friendly, menu-driven format, and for automatic execution once the input data has been entered.

  3. Achievement in Problem Solving

    ERIC Educational Resources Information Center

    Friebele, David

    2010-01-01

    This Action Research Project is meant to investigate the effects of incorporating research-based instructional strategies into instruction and their subsequent effect on student achievement in the area of problem-solving. The two specific strategies utilized are the integration of manipulatives and increased social interaction on a regular basis.…

  4. Dynamical impurity problems

    SciTech Connect

    Emery, V.J.; Kivelson, S.A.

    1993-12-31

    In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.

  5. Thermodynamics with Design Problems.

    ERIC Educational Resources Information Center

    Cilento, E. V.; Sears, J. T.

    1983-01-01

    Discusses how basic thermodynamics concepts are integrated with design problems. Includes course goals, instructional strategies, and major advantages/disadvantages of the integrated design approach. Advantages include making subject more concrete, emphasizing interrelation of variables, and reinforcing concepts by use in design analysis; whereas…

  6. Tackling a Local Problem.

    ERIC Educational Resources Information Center

    Cook, Martin

    1995-01-01

    Students studying water as a class project were concerned by levels of pollution at a nearby river and the local beach. They identified three environmental problems for research including sewage discharge, beach litter, and quality of swimming water. Research consisted of field trips which allowed for opportunities to improve skills in collecting…

  7. The Eight Queens Problem.

    ERIC Educational Resources Information Center

    Olson, Alton T.

    1993-01-01

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

  8. Solving Problems Reductively

    ERIC Educational Resources Information Center

    Armoni, Michal; Gal-Ezer, Judith; Tirosh, Dina

    2005-01-01

    Solving problems by reduction is an important issue in mathematics and science education in general (both in high school and in college or university) and particularly in computer science education. Developing reductive thinking patterns is an important goal in any scientific discipline, yet reduction is not an easy subject to cope with. Still,…

  9. Children Solve Problems.

    ERIC Educational Resources Information Center

    De Bono, Edward

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

  10. Problem Solving with Patents

    ERIC Educational Resources Information Center

    Moore, Jerilou; Sumrall, William J.

    2008-01-01

    Exploring our patent system is a great way to engage students in creative problem solving. As a result, the authors designed a teaching unit that uses the study of patents to explore one avenue in which scientists and engineers do science. Specifically, through the development of an idea, students learn how science and technology are connected.…

  11. A Multifaceted Minimization Problem.

    ERIC Educational Resources Information Center

    Pomeranz, Janet Bellcourt

    1983-01-01

    The problem "Given three planar points, find a point such that the sum of the distances from that point to the three points is a minimum" is discussed from several points of view. A solution that uses only calculus and geometry is examined in detail. (MNS)

  12. Constructed-Response Problems

    ERIC Educational Resources Information Center

    Swinford, Ashleigh

    2016-01-01

    With rigor outlined in state and Common Core standards and the addition of constructed-response test items to most state tests, math constructed-response questions have become increasingly popular in today's classroom. Although constructed-response problems can present a challenge for students, they do offer a glimpse of students' learning through…

  13. Tackling a Local Problem.

    ERIC Educational Resources Information Center

    Cook, Martin

    1995-01-01

    Students studying water as a class project were concerned by levels of pollution at a nearby river and the local beach. They identified three environmental problems for research including sewage discharge, beach litter, and quality of swimming water. Research consisted of field trips which allowed for opportunities to improve skills in collecting…

  14. [Problem Solving Activities.

    ERIC Educational Resources Information Center

    Wisconsin Univ. - Stout, Menomonie. Center for Vocational, Technical and Adult Education.

    The teacher directed problem solving activities package contains 17 units: Future Community Design, Let's Build an Elevator, Let's Construct a Catapult, Let's Design a Recreational Game, Let's Make a Hand Fishing Reel, Let's Make a Wall Hanging, Let's Make a Yo-Yo, Marooned in the Past, Metrication, Mousetrap Vehicles, The Multi System…

  15. Managing Global Problems.

    ERIC Educational Resources Information Center

    Stanley, C. Maxwell

    The book examines the historical background of and accomplishments in seven global problem areas. It is hypothesized that effective management within today's framework is the only way to progress toward the political and economic order that is necessary to assure peace and security, justice, and human rights, and to improve the quality of life. It…

  16. Problem Solving with Patents

    ERIC Educational Resources Information Center

    Moore, Jerilou; Sumrall, William J.

    2008-01-01

    Exploring our patent system is a great way to engage students in creative problem solving. As a result, the authors designed a teaching unit that uses the study of patents to explore one avenue in which scientists and engineers do science. Specifically, through the development of an idea, students learn how science and technology are connected.…

  17. Convention Problems - 1787.

    ERIC Educational Resources Information Center

    Hanson, Deroy L.

    Designed to motivate eighth-grade civics students in the study of the United States Constitution, this game is intended to simulate the basic problems faced by the delegates to the Philadelphia Convention of 1787. The four parts of the game introduce the governmental concepts of the bicameral legislature, the executive branch, the judicial branch,…

  18. Problem Solving Using Microcomputers.

    ERIC Educational Resources Information Center

    Demana, Franklin; Waits, Bert

    1987-01-01

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

  19. The Problem of Consciousness.

    ERIC Educational Resources Information Center

    Crick, Francis; Koch, Christof

    1992-01-01

    Discusses approaches to the problem presented in understanding consciousness as a yet undiscovered process of interacting neuron activity. Presents the historical context of research in the area of human awareness and identifies research necessary to scientifically explain how the brain relates to the mind. (MCO)

  20. Convention Problems - 1787.

    ERIC Educational Resources Information Center

    Hanson, Deroy L.

    Designed to motivate eighth-grade civics students in the study of the United States Constitution, this game is intended to simulate the basic problems faced by the delegates to the Philadelphia Convention of 1787. The four parts of the game introduce the governmental concepts of the bicameral legislature, the executive branch, the judicial branch,…

  1. Constructed-Response Problems

    ERIC Educational Resources Information Center

    Swinford, Ashleigh

    2016-01-01

    With rigor outlined in state and Common Core standards and the addition of constructed-response test items to most state tests, math constructed-response questions have become increasingly popular in today's classroom. Although constructed-response problems can present a challenge for students, they do offer a glimpse of students' learning through…

  2. Human Population Problems

    ERIC Educational Resources Information Center

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

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

  3. The Gravity Problem

    ERIC Educational Resources Information Center

    Oberlin, Lynn

    1974-01-01

    Discusses the problem of gravity as it relates to distance from the center of the earth, and reports contradictory explanations from different source books. Uses this example to illustrate that science should not be taught from a single source, such as a textbook. (JR)

  4. Types of Learning Problems

    MedlinePlus

    ... of time in their own world—even for teenagers—but they’re often lonely and want to make friends. The problem is, they’re not sure how to act in social settings. Between that and their eccentricities, they may become victims of teasing and bullying . Parents of a child with AS, or any ...

  5. Unfolding a Problem

    ERIC Educational Resources Information Center

    Currier, Sarah Cox

    2015-01-01

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

  6. Solving Problems through Circles

    ERIC Educational Resources Information Center

    Grahamslaw, Laura; Henson, Lisa H.

    2015-01-01

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

  7. The solar neutrino problem.

    NASA Astrophysics Data System (ADS)

    Xu, Renxin; Luo, Xianhan

    1995-12-01

    The solar neutrino problem (SNP) is reviewed on the bases of neutrino physics, solar neutrino detection and standard solar model. It is interesting that the detected neutrino flux values of different solar neutrino detectors are lower than the values calculated by SMM in different degree. The studies on SNP in particle physics and in astrophysics are also discussed respectively.

  8. Human Population Problems

    ERIC Educational Resources Information Center

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

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

  9. The Problem of Consciousness.

    ERIC Educational Resources Information Center

    Crick, Francis; Koch, Christof

    1992-01-01

    Discusses approaches to the problem presented in understanding consciousness as a yet undiscovered process of interacting neuron activity. Presents the historical context of research in the area of human awareness and identifies research necessary to scientifically explain how the brain relates to the mind. (MCO)

  10. "Righting" the Writing Problem.

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.; Eastham, Nicholas

    The problem of college students' writing skills or lack thereof is generally agreed upon in academia. One cause is the inordinate amount of multiple choice/true false/fill in the blank type of tests that students take in high school and college. Not only is there is a dearth of actual classes in writing available, few students recognize the need…

  11. The Problems of Translation.

    ERIC Educational Resources Information Center

    Huntsman, Jeffrey F.

    The problems confronting the translator of American Indian literature are immense. The history of European Indian relations has obscured many original Indian values and attitudes and has substituted a set of simplistic and unreal Anglo attitudes that translators must transcend. Unlike most Western literature, Indian literature does not instruct,…

  12. Universal Design Problem Solving

    ERIC Educational Resources Information Center

    Sterling, Mary C.

    2004-01-01

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

  13. Circumference and Problem Solving.

    ERIC Educational Resources Information Center

    Blackburn, Katie; White, David

    The concept of pi is one of great importance to all developed civilization and one that can be explored and mastered by elementary students through an inductive and problem-solving approach. Such an approach is outlined and discussed. The approach involves the following biblical quotation: "And he made a moltin sea ten cubits from one brim to…

  14. An Isometric Problem Revisited.

    ERIC Educational Resources Information Center

    Beslin, Scott J.; Simmons, Laurette L.

    1993-01-01

    Offers heuristic arguments showing that a simple closed curve of specified length that encloses a maximum area must be a circle. Develops the problem by demonstrating that such an n-gon must be convex, that such a convex n-gon must be regular, and that such a simple closed curve must be a circle. (MDH)

  15. Solving Problems in Genetics

    ERIC Educational Resources Information Center

    Aznar, Mercedes Martinez; Orcajo, Teresa Ibanez

    2005-01-01

    A teaching unit on genetics and human inheritance using problem-solving methodology was undertaken with fourth-level Spanish Secondary Education students (15 year olds). The goal was to study certain aspects of the students' learning process (concepts, procedures and attitude) when using this methodology in the school environment. The change…

  16. Sexual Problems of Counselees.

    ERIC Educational Resources Information Center

    Heritage, Jeannette G.; West, W. Beryl

    Approximately 50% of American marriages have some sexual dysfunction. Because sexuality is an important part of a person's life, counselors should be sensitive to sexual concerns of their clients. Taking an adequate sex history and highlighting problem areas may increase counseling efficiency. When counselors teach courses on human sexuality, they…

  17. and Internalizing Behavior Problems

    ERIC Educational Resources Information Center

    Hofer, Claire; Eisenberg, Nancy; Spinrad, Tracy L.; Morris, Amanda S.; Gershoff, Elizabeth; Valiente, Carlos; Kupfer, Anne; Eggum, Natalie D.

    2013-01-01

    Stability and change in mother-adolescent conflict reactions (CRs) and the prediction of CRs from adolescents' earlier behavior problems (and vice versa) were examined with 131 mothers and their adolescents (63 boys). Dyads engaged in a 6-min conflict discussion twice, 2 years apart ["M" age was 13 at Time 1 (T1)]. Non-verbal expressive…

  18. Fuelwood Problems and Solutions

    Treesearch

    D. Evan Mercer; John Soussan

    1992-01-01

    Concern over the "fuelwood crisis" facing the world's poor has been widespread since the late 1970s (Eckholm et al. 1984; Soussan 1988; Agarwal 1986). At first the problem was frequently overstated. In the extreme, analysts (foresters, economists, and others) in many countries made erroneous projections of the rapid total destruction of the biomass...

  19. and Internalizing Behavior Problems

    ERIC Educational Resources Information Center

    Hofer, Claire; Eisenberg, Nancy; Spinrad, Tracy L.; Morris, Amanda S.; Gershoff, Elizabeth; Valiente, Carlos; Kupfer, Anne; Eggum, Natalie D.

    2013-01-01

    Stability and change in mother-adolescent conflict reactions (CRs) and the prediction of CRs from adolescents' earlier behavior problems (and vice versa) were examined with 131 mothers and their adolescents (63 boys). Dyads engaged in a 6-min conflict discussion twice, 2 years apart ["M" age was 13 at Time 1 (T1)]. Non-verbal expressive…

  20. Chemical Reaction Problem Solving.

    ERIC Educational Resources Information Center

    Veal, William

    1999-01-01

    Discusses the role of chemical-equation problem solving in helping students predict reaction products. Methods for helping students learn this process must be taught to students and future teachers by using pedagogical skills within the content of chemistry. Emphasizes that solving chemical reactions should involve creative cognition where…

  1. Managing soil remediation problems.

    PubMed

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

    1996-12-01

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

  2. Universal Design Problem Solving

    ERIC Educational Resources Information Center

    Sterling, Mary C.

    2004-01-01

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

  3. Problems with Institutional Surveys.

    ERIC Educational Resources Information Center

    Frey, James H.

    1979-01-01

    A survey done properly by accepted and scientifically justifiable techniques can provide information on behalf of the goals of institutional advancement in academe. Deficiencies in institutional research are seen as the result of the lack of guidance on survey design, questionnaire construction, or problem definition in education research texts.…

  4. Whose Problem Is It!

    ERIC Educational Resources Information Center

    Mansfield, Deborah; And Others

    "Whose Problem Is It" is a workshop for middle level students that encourages their participation, input, and ownership in accomplishing change in the middle level school policies, program and procedure. The workshop revolves around making the school environment a happy, healthy, and productive place for learning. It consists of…

  5. Solving Problems through Circles

    ERIC Educational Resources Information Center

    Grahamslaw, Laura; Henson, Lisa H.

    2015-01-01

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

  6. Problems of Excess Capacity

    NASA Technical Reports Server (NTRS)

    Douglas, G.

    1972-01-01

    The problems of excess capacity in the airline industry are discussed with focus on the following topics: load factors; fair rate of return on investment; service-quality rivalry among airlines; pricing (fare) policies; aircraft production; and the impacts of excess capacity on operating costs. Also included is a discussion of the interrelationships among these topics.

  7. LEXICOGRAPHICAL PROBLEMS IN PASHTO.

    ERIC Educational Resources Information Center

    CHAVARRIS-AGUILAR, O.L.; PENZL, HERBERT

    PROBLEMS IN DEVELOPING SUITABLE DICTIONARIES OF PASHTO WERE REPORTED. PASHTO WAS DESCRIBED AS A MEMBER OF THE IRANIAN BRANCH OF THE INDO-EUROPEAN LANGUAGES SPOKEN IN EASTERN AND SOUTHERN AFGHANISTAN AND IN NORTHEASTERN PAKISTAN. FIVE TOPICS DEALING WITH THE PASHTO LANGUAGE WERE DISCUSSED--(1) STATISTICS, (2) WRITTEN CORPUS AND LEXICAL STUDIES, (3)…

  8. The tree alignment problem.

    PubMed

    Varón, Andrés; Wheeler, Ward C

    2012-11-09

    The inference of homologies among DNA sequences, that is, positions in multiple genomes that share a common evolutionary origin, is a crucial, yet difficult task facing biologists. Its computational counterpart is known as the multiple sequence alignment problem. There are various criteria and methods available to perform multiple sequence alignments, and among these, the minimization of the overall cost of the alignment on a phylogenetic tree is known in combinatorial optimization as the Tree Alignment Problem. This problem typically occurs as a subproblem of the Generalized Tree Alignment Problem, which looks for the tree with the lowest alignment cost among all possible trees. This is equivalent to the Maximum Parsimony problem when the input sequences are not aligned, that is, when phylogeny and alignments are simultaneously inferred. For large data sets, a popular heuristic is Direct Optimization (DO). DO provides a good tradeoff between speed, scalability, and competitive scores, and is implemented in the computer program POY. All other (competitive) algorithms have greater time complexities compared to DO. Here, we introduce and present experiments a new algorithm Affine-DO to accommodate the indel (alignment gap) models commonly used in phylogenetic analysis of molecular sequence data. Affine-DO has the same time complexity as DO, but is correctly suited for the affine gap edit distance. We demonstrate its performance with more than 330,000 experimental tests. These experiments show that the solutions of Affine-DO are close to the lower bound inferred from a linear programming solution. Moreover, iterating over a solution produced using Affine-DO shows little improvement. Our results show that Affine-DO is likely producing near-optimal solutions, with approximations within 10% for sequences with small divergence, and within 30% for random sequences, for which Affine-DO produced the worst solutions. The Affine-DO algorithm has the necessary scalability and

  9. The tree alignment problem

    PubMed Central

    2012-01-01

    Background The inference of homologies among DNA sequences, that is, positions in multiple genomes that share a common evolutionary origin, is a crucial, yet difficult task facing biologists. Its computational counterpart is known as the multiple sequence alignment problem. There are various criteria and methods available to perform multiple sequence alignments, and among these, the minimization of the overall cost of the alignment on a phylogenetic tree is known in combinatorial optimization as the Tree Alignment Problem. This problem typically occurs as a subproblem of the Generalized Tree Alignment Problem, which looks for the tree with the lowest alignment cost among all possible trees. This is equivalent to the Maximum Parsimony problem when the input sequences are not aligned, that is, when phylogeny and alignments are simultaneously inferred. Results For large data sets, a popular heuristic is Direct Optimization (DO). DO provides a good tradeoff between speed, scalability, and competitive scores, and is implemented in the computer program POY. All other (competitive) algorithms have greater time complexities compared to DO. Here, we introduce and present experiments a new algorithm Affine-DO to accommodate the indel (alignment gap) models commonly used in phylogenetic analysis of molecular sequence data. Affine-DO has the same time complexity as DO, but is correctly suited for the affine gap edit distance. We demonstrate its performance with more than 330,000 experimental tests. These experiments show that the solutions of Affine-DO are close to the lower bound inferred from a linear programming solution. Moreover, iterating over a solution produced using Affine-DO shows little improvement. Conclusions Our results show that Affine-DO is likely producing near-optimal solutions, with approximations within 10% for sequences with small divergence, and within 30% for random sequences, for which Affine-DO produced the worst solutions. The Affine-DO algorithm has

  10. Network improvement problems

    SciTech Connect

    Krumke, S.O.; Noltemeier, H.; Drangmeister, K.U.; Marathe, M.V.; Ravi, S.S.

    1995-09-01

    The authors study budget constrained optimal network improvement problems. Such problems aim at finding optimal strategies for improving a network under some cost measure subject to certain budget constraints. As an example, consider the following prototypical problem: Let G = (V, E) be an undirected graph with two cost values L(e) and C(e) associated with each edge e, where L(e) denotes the length of e and C(e) denotes the cost of reducing the length of e by a unit amount. A reduction strategy specifies for each edge e, the amount by which L(e) is to be reduced. For a given budget B, the goal is to find a reduction strategy such that the total cost of reduction is at most B and the minimum cost tree (with respect to some measure M) under the modified L costs is the best over all possible reduction strategies which obey the budget constraint. Typical measures M for a tree are the total weight and the diameter. They provide both hardness and approximation results for the two measures M mentioned above. For the problem of minimizing the total weight of a spacing tree, they provide an algorithm that, for any fixed {gamma},{var_epsilon} > 0, finds a solution whose weight is at most (1 + 1/{gamma}) times that of a minimum length spanning tree plus an additive constant of at most {var_epsilon} and the total cost of improvement is at most (1 + {gamma}) times the budget B. This result can be extended to obtain approximation algorithms for more general network design problems considered in [GW, GG+94].

  11. A model for routing problem in quay management problem

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  12. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1985-01-01

    The focus is on the problem-solving strategy of find a pattern, with a problem explored to illustrate how to use the strategy. Other tips concern classroom climate, checking skills, research, and type of problems. (MNS)

  13. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1984-01-01

    The problem-solving strategy of making an organized list is highlighted, with a problem and suggestions for teaching the strategy. Other suggestions for teaching problem solving are then presented. (MNS)

  14. Gravitational Many-Body Problem

    SciTech Connect

    Makino, J.

    2008-04-29

    In this paper, we briefly review some aspects of the gravitational many-body problem, which is one of the oldest problems in the modern mathematical science. Then we review our GRAPE project to design computers specialized to this problem.

  15. Buffon's Coin Problem and beyond

    ERIC Educational Resources Information Center

    Schneiter, Kady

    2011-01-01

    This article describes an investigation of Buffon's coin problem and related problems with the aid of an applet. The problems are accessible at a variety of grade levels and facilitate making connections between geometry and probability.

  16. Gravitational Many-Body Problem

    NASA Astrophysics Data System (ADS)

    Makino, J.

    2008-04-01

    In this paper, we briefly review some aspects of the gravitational many-body problem, which is one of the oldest problems in the modern mathematical science. Then we review our GRAPE project to design computers specialized to this problem.

  17. Solving A Corrosion Problem

    NASA Technical Reports Server (NTRS)

    1979-01-01

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

  18. Modern problems of thermodynamics

    NASA Astrophysics Data System (ADS)

    Novikov, I. I.

    2012-12-01

    The role of energy and methods of its saving for the development of human society and life are analyzed. The importance of future use of space energy flows and energy of water and air oceans is emphasized. The authors consider the idea of the unit for production of electric energy and pure substances using sodium chloride which reserves are limitless on the planet. Looking retrospectively at the development of power engineering from the elementary fire to modern electric power station, we see that the used method of heat production, namely by direct interaction of fuel and oxidizer, is the simplest. However, it may be possible to combust coal, i.e., carbon in salt melt, for instance, sodium chloride that would be more rational and efficient. If the stated problems are solved positively, we would master all energy properties of the substance; and this is the main problem of thermodynamics being one of the sciences on energy.

  19. Solving bearing overheating problems

    SciTech Connect

    Jendzurski, T.

    1995-05-08

    Overheating is a major indicator, along with vibration and noise, of an underlying problem affecting a bearing or related components. Because normal operating temperatures vary widely from one application to another, no single temperature is a reliable sign of overheating in every situation. By observing an application when it is running smoothly, a technician can establish a benchmark temperature for a particular bearing arrangement. Wide deviations from this accepted norm generally indicate troublesome overheating. The list of possible causes of over-heating ranges from out-of-round housings and oversize shaft diameters to excessive lubrication and bearing preloading. These causes fall into two major categories: improper or faulty lubrication and mechanical problems, such as incorrect fits and tolerances. These are discussed along with solutions.

  20. Science education problems summarized

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    Chief among the concerns over the declining quality of science, mathematics, and technology education is declining achievement and participation at a time of increasing national needs, according to the first formal report of the National Science Board Commission on Precollege Education in Mathematics, Science, and Technology. The report defines the problems and sets the stage for the next year's work. The commission, formed earlier this year (Eos, June 15, p. 538), will conclude its 18—month effort next October.Exacerbating the education problems, the report says, are a growing shortage of qualified secondary school mathematics and physical science teachers; inadequate classroom facilities and instructional time; and curricula sorely in need of revision. The report also concludes that ’in general, precollege mathematics, science, and technology instruction has yet to take advantage of the advances in technology and behavioral sciences of the past 20 years.’

  1. Medical problems in pregnancy.

    PubMed

    Narayan, Bhaskar; Nelson-Piercy, Catherine

    2016-12-01

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

  2. The Protein Folding Problem

    PubMed Central

    Dill, Ken A.; Ozkan, S. Banu; Shell, M. Scott; Weikl, Thomas R.

    2008-01-01

    The “protein folding problem” consists of three closely related puzzles: (a) What is the folding code? (b) What is the folding mechanism? (c) Can we predict the native structure of a protein from its amino acid sequence? Once regarded as a grand challenge, protein folding has seen great progress in recent years. Now, foldable proteins and nonbiological polymers are being designed routinely and moving toward successful applications. The structures of small proteins are now often well predicted by computer methods. And, there is now a testable explanation for how a protein can fold so quickly: A protein solves its large global optimization problem as a series of smaller local optimization problems, growing and assembling the native structure from peptide fragments, local structures first. PMID:18573083

  3. The inhibiting bisection problem.

    SciTech Connect

    Pinar, Ali

    2010-11-01

    Given a graph where each vertex is assigned a generation or consumption volume, we try to bisect the graph so that each part has a significant generation/consumption mismatch, and the cutsize of the bisection is small. Our motivation comes from the vulnerability analysis of distribution systems such as the electric power system. We show that the constrained version of the problem, where we place either the cutsize or the mismatch significance as a constraint and optimize the other, is NP-complete, and provide an integer programming formulation. We also propose an alternative relaxed formulation, which can trade-off between the two objectives and show that the alternative formulation of the problem can be solved in polynomial time by a maximum flow solver. Our experiments with benchmark electric power systems validate the effectiveness of our methods.

  4. FBST for Cointegration Problems

    NASA Astrophysics Data System (ADS)

    Diniz, M.; Pereira, C. A. B.; Stern, J. M.

    2008-11-01

    In order to estimate causal relations, the time series econometrics has to be aware of spurious correlation, a problem first mentioned by Yule [21]. To solve the problem, one can work with differenced series or use multivariate models like VAR or VEC models. In this case, the analysed series are going to present a long run relation i.e. a cointegration relation. Even though the Bayesian literature about inference on VAR/VEC models is quite advanced, Bauwens et al. [2] highlight that "the topic of selecting the cointegrating rank has not yet given very useful and convincing results." This paper presents the Full Bayesian Significance Test applied to cointegration rank selection tests in multivariate (VAR/VEC) time series models and shows how to implement it using available in the literature and simulated data sets. A standard non-informative prior is assumed.

  5. Eldercare at Home: Breathing Problems

    MedlinePlus

    ... sleepy. For more information, visit Sleep Problems . Avoid sleeping pills. All people with lung problems should avoid sedatives (sleeping pills including those that are available with a prescription) ...

  6. Impact and Penetration Problems.

    DTIC Science & Technology

    1981-03-16

    is the atomic distance and 2Z is the punch width. The nonlocal analysis of the rigid punch problem leads to the following conclusions: i) flonlocal...classical analysis , the viscous stresses at the periphery of the plug are found to be finite. (ii) The critical velocity for the initial plug formation is...effects. In addition, the nonlocal inter- molecular forces must be taken into account. In [10], a nonlocal analysis of plug formation in visco-plastic

  7. Working on interesting problems

    NASA Astrophysics Data System (ADS)

    Smith, Arfon M.

    2015-01-01

    BSc Chemistry, The University of Sheffield 2001... PhD Astrochemistry, The University of Nottingham 2006... Scientist at GitHub Inc. 2013.From the outside, the path an individual has taken from academia to industry is not an obvious one. In this session I'll (try and) explain how an interest in software, engineering and chasing interesting problems makes internet startup in San Francisco a great home.

  8. Dynamic bin packing problem

    NASA Technical Reports Server (NTRS)

    Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok K.; Larsen, Ronald L.

    1989-01-01

    In a previous work we have defined a general architecture model for autonomous systems, which can be mapped easily to describe the functions of any automated system (SDAG-86-01). In this note, we use the model to describe the problem of thermal management in space stations. First we briefly review the architecture, then we present the environment of our application, and finally we detail the specific function for each functional block of the architecture for that environment.

  9. EVA medical problems

    NASA Astrophysics Data System (ADS)

    Barer, A. S.

    The experience gained in the USSR allows the following conclusions: physiological responses to EVA do not depend on flight duration in qualitative and quantative terms. Physiological responses to EVA are mainly determined by following 3 factors: physiological activities; space suit environmental parameters; physiological stress. This paper reviews problems, associated with altitude decompression sickness; thermal regulation of the body, visual function and physiological psychological stress as well as individual EVA experience in physiological responses.

  10. Problem Solving and Reasoning.

    DTIC Science & Technology

    1984-02-01

    Sloan Foundation (HAS). This paper is a draft of a chapter to appear in R. C. Atkinson, R. Herrnstein, G. Lindzey, and R. D. Luce (Eds.), Stevens ...D. Luce (Eds.), Stevens ’ Handbook of Experimental Psychology, (Revised Edition). New York: John Wiley & Sons. PROBLEM SOLVING AND REASONING James G... LaBerge & S. J. Samuels (Eds.), Perception and comprehension. Hillsdale, NJ: Erlbaum. Anderson, J. R. (1982). Acquisition of cognitive skill

  11. Problem Solving and Reasoning

    DTIC Science & Technology

    1988-01-01

    response fre- of homework or test problems that the class was lems were esented quencies in two tasks. Findings that fit this working on at the time...psychological models were th this students who receive these tasks as homework simpler, and the inferences about processes ved by assignments and...quantitative relations study of children from kindergarten through and stud, nts must be able to choose formulas third grade. The versions differ in

  12. Collinear Points Problem

    ERIC Educational Resources Information Center

    Shultz, Harris S.; Shiflett, Ray C.

    2008-01-01

    Students were asked to find all possible values for A so that the points (1, 2), (5, A), and (A, 7) lie on a straight line. This problem suggests a generalization: Given (x, y), find all values of A so that the points (x, y), (5, A), and (A, 7) lie on a straight line. We find that this question about linear equations must be resolved using the…

  13. Problems in Prosthetics

    PubMed Central

    Murray, Duncan

    1989-01-01

    In the ever-evolving scientific world of medicine, prostheses continue to fulfill a necessary function. Modern aggressive management of such diseases as diabetes, stroke, and peripheral vascular disease has been matched by new technology and attitudes in the world of prosthetics. The final common denominator continues to be the patient. The problems patients have continue to be the focus of the Rehabilitation physician. PMID:21248888

  14. The Henry Problem Revisited

    NASA Astrophysics Data System (ADS)

    Karasaki, K.; Oldenburg, C. M.; Maekawa, K.

    2006-12-01

    We have modeled laboratory experiments of saltwater intrusion in a configuration resembling the so-called Henry Problem using TOUGH2/EOS7. The experiment differs from the Henry Problem in that the freshwater boundary condition is that of Dirichlet, a difference that is not expected to affect the overall results very much. The simulation matched the saltwater wedge profile of the experiment, the main feature of which was the sharp interface (lack of dispersion) between the freshwater and saltwater. Prior solutions of the Henry Problem show a wide transition zone between freshwater and saltwater arising from the use of a large dispersion coefficient. Henry attributed the large dispersion to the effect of tidally induced motion. In our simulation, we imposed a time-varying sinusoidal boundary condition to see if a larger transition zone can be created without using a larger dispersion coefficient. However, for the parameters used we were not able to do so. It is still plausible that the wide transition zone observed at Biscayne Bay (and as modeled in the Henry Problem) is caused by a particular formation heterogeneity and transient effects. Our analysis, based on a laboratory experiment and accompanying modeling, suggests that dispersion is quite limited. Nonetheless, we question the validity of the use of a large dispersion coefficient where the groundwater velocity is very low, or where the flow is in the opposite direction of the concentration gradient. This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231

  15. Collinear Points Problem

    ERIC Educational Resources Information Center

    Shultz, Harris S.; Shiflett, Ray C.

    2008-01-01

    Students were asked to find all possible values for A so that the points (1, 2), (5, A), and (A, 7) lie on a straight line. This problem suggests a generalization: Given (x, y), find all values of A so that the points (x, y), (5, A), and (A, 7) lie on a straight line. We find that this question about linear equations must be resolved using the…

  16. Problems with corneal arcus.

    PubMed

    Fielder, A R; Winder, A F; Sheraidah, G A; Cooke, E D

    1981-01-01

    Corneal arcus presents many puzzling features. The correlation between its incidence and serum lipid levels is poor and, using immunoelectrophoresis, we have only been able to identify low-density lipoprotein inconsistently in corneae containing this deposition. Infrared thermography has shown us that arcus commences in the warmest regions of the cornea. We have considered the possible relevance of our biochemical and thermographic findings to other problems with corneal arcus such as its irreversibility, anatomical distribution, and clear zone.

  17. Energy - A systems problem

    NASA Technical Reports Server (NTRS)

    Bourke, Roger D.

    1982-01-01

    Energy management in its most comprehensive sense encompasses economic, technical, environmental, and political problems. The present evaluation of prospects notes that opportunities for energy conservation are widespread, in such fields as building air conditioning, transportation, electrical appliances, and industrial processes. Further conservation is expected to be achieved through a combination of technology development and economics; the latter factor must not be unduly influenced by political measures that shield consumers from the true cost of energy.

  18. Dynamic bin packing problem

    NASA Technical Reports Server (NTRS)

    Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok K.; Larsen, Ronald L.

    1989-01-01

    In a previous work we have defined a general architecture model for autonomous systems, which can be mapped easily to describe the functions of any automated system (SDAG-86-01). In this note, we use the model to describe the problem of thermal management in space stations. First we briefly review the architecture, then we present the environment of our application, and finally we detail the specific function for each functional block of the architecture for that environment.

  19. The Feline Josephus Problem

    NASA Astrophysics Data System (ADS)

    Ruskey, Frank; Williams, Aaron

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

  20. On the Feynman Problem

    NASA Astrophysics Data System (ADS)

    D'Ariano, Giacomo

    2012-02-01

    Foundations of Quantum Field Theory can be connected to foundations of Quantum Theory if we can derive the former in terms of the latter with two additional postulates of locality and topological homogeneity of interactions between quantum systems, in the hypothesis that a quantum field is ultimately made of a numerable set of quantum systems that are unitarily interacting. But, in order to do that we need to be able to simulate quantumm field by a quantum computer. In the paper ``Simulating Physics with Computers'' (Int. J. Th. Phys, 21 467 (1982)) Richard Feynman raised the problem whether it is possible to simulate Fermi fields by a quantum computer---in short if we can ``qubit-ize'' a Fermi field, keeping the field interaction local on qubits. In this talk I will show how this problem is solved for any space-dimension, upon introducing a new general Jordan-Wigner map between field and qubits, and by adding witnessing auxiliary qubits. I will also derive the unique vacuum for the Fermi fields and for the auxiliary fields. The solution of the Feynman problem allows us to simulate quantum fields by a quantum cellular automata, also providing a kind of Planck-scale version of quantum field theory. Computer simulations will be projected at the end of the talk

  1. Ear problems in swimmers.

    PubMed

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

    2005-08-01

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

  2. High Altitude Medical Problems

    PubMed Central

    Hultgren, Herbert N.

    1979-01-01

    Increased travel to high altitude areas by mountaineers and nonclimbing tourists has emphasized the clinical problems associated with rapid ascent. Acute mountain sickness affects most sojourners at elevations above 10,000 feet. Symptoms are usually worse on the second or third day after arrival. Gradual ascent, spending one to three days at an intermediate altitude, and the use of acetazolamide (Diamox) will prevent or ameliorate symptoms in most instances. Serious and potentially fatal problems, such as high altitude pulmonary edema or cerebral edema, occur in approximately 0.5 percent to 1.0 percent of visitors to elevations above 10,000 feet—especially with heavy physical exertion on arrival, such as climbing or skiing. Early recognition, high flow oxygen therapy and prompt descent are crucially important in management. Our knowledge of the causes of these and other high altitude problems, such as retinal hemorrhage, systemic edema and pulmonary hypertension, is still incomplete. Even less is known of the effect of high altitudes on medical conditions common at sea level or on the action of commonly used drugs. ImagesFigure 2. PMID:483805

  3. Measuring Family Problem Solving: The Family Problem Solving Diary.

    ERIC Educational Resources Information Center

    Kieren, Dianne K.

    The development and use of the family problem-solving diary are described. The diary is one of several indicators and measures of family problem-solving behavior. It provides a record of each person's perception of day-to-day family problems (what the problem concerns, what happened, who got involved, what those involved did, how the problem…

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

    ERIC Educational Resources Information Center

    Mairing, Jackson Pasini

    2017-01-01

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

  5. Adolescent Temperament: Childhood Problem Precursors and Problem Behavior Correlates.

    ERIC Educational Resources Information Center

    Windle, Michael

    Interrelations between childhood behavior problems and adolescent temperament, and between adolescent temperament and problem behaviors, were studied. A sample of 311 adolescents with an average age of 15.7 years completed self-report measures regarding behavior problems before age 13, temperament, alcohol consumption, alcohol-related problems,…

  6. Problem-Framing: A perspective on environmental problem-solving

    NASA Astrophysics Data System (ADS)

    Bardwell, Lisa V.

    1991-09-01

    The specter of environmental calamity calls for the best efforts of an involved public. Ironically, the way people understand the issues all too often serves to discourage and frustrate rather than motivate them to action. This article draws from problem-solving perspectives offered by cognitive psychology and conflict management to examine a framework for thinking about environmental problems that promises to help rather than hinder efforts to address them. Problem-framing emphasizes focusing on the problem definition. Since how one defines a problem determines one's understanding of and approach to that problem, being able to redefine or reframe a problem and to explore the “problem space” can help broaden the range of alternatives and solutions examined. Problem-framing incorporates a cognitive perspective on how people respond to information. It explains why an emphasis on problem definition is not part of people's typical approach to problems. It recognizes the importance of structure and of having ways to organize that information on one's problem-solving effort. Finally, problem-framing draws on both cognitive psychology and conflict management for strategies to manage information and to create a problem-solving environment that not only encourages participation but can yield better approaches to our environmental problems.

  7. Quantum Hall Effect of Massless Dirac Fermions and Free Fermions in Hofstadter's Butterfly

    NASA Astrophysics Data System (ADS)

    Yoshioka, Nobuyuki; Matsuura, Hiroyasu; Ogata, Masao

    2016-06-01

    We propose a new physical interpretation of the Diophantine equation of σxy for the Hofstadter problem. First, we divide the energy spectrum, or Hofstadter's butterfly, into smaller self-similar areas called "subcells", which were first introduced by Hofstadter to describe the recursive structure. We find that in the energy gaps between subcells, there are two ways to account for the quantization rule of σxy, that are consistent with the Diophantine equation: Landau quantization of (i) massless Dirac fermions or (ii) free fermions in Hofstadter's butterfly.

  8. Problem Solving: Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G., Ed.; Schaaf, Oscar

    1986-01-01

    Describes: (1) a computation-oriented problem with procedures and some questions that might be asked of students; (2) four ways to help students develop positive problem-solving attitudes; (3) a strategy game; (4) a multiplication problem; and (5) several questions that will help students develop problem-solving skills. (JN)

  9. Problem Order Implications for Learning

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  10. Design Problems for Secondary Students

    ERIC Educational Resources Information Center

    Jonassen, David H.

    2011-01-01

    Are there different kinds of design problems? Jonassen (2011) argued that problems vary in terms of structuredness, complexity, and context. On the structuredness and complexity continua, design problems tend to be the most ill-structured and complex. Brown and Chandrasekaran suggest that design problems may vary along a continuum from…

  11. Problem-Based Learning Tools

    ERIC Educational Resources Information Center

    Chin, Christine; Chia, Li-Gek

    2008-01-01

    One way of implementing project-based science (PBS) is to use problem-based learning (PBL), in which students formulate their own problems. These problems are often ill-structured, mirroring complex real-life problems where data are often messy and inclusive. In this article, the authors describe how they used PBL in a ninth-grade biology class in…

  12. Problem Order Implications for Learning

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  13. Model for assessing psychosocial problems.

    PubMed Central

    Tannenbaum, D.; McGillivray, M.

    1996-01-01

    The Model for the Assessment of Psychosocial Problems (MAPP) can help family medicine residents effectively assess patients with psychosocial problems. Following a patient-centred clinical method, MAPP provides a guide to exploring problems and an approach that allows residents and patients jointly to define problems and decide upon management. Emphasis is placed on clarifying patients' expectations of physicians. PMID:9222578

  14. Creating Games from Mathematical Problems

    ERIC Educational Resources Information Center

    Pinter, Klara

    2011-01-01

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

  15. Space Power Engineering Problems

    NASA Astrophysics Data System (ADS)

    Senkevich, V. P.

    2002-01-01

    Development of space power engineering in the first half of XXI century shall be aimed at preventing the forthcoming energy crisis and ecological catastrophes. The problem can be solved through using solar energy being perpetual, endless, and ecologically safe. As of now, issues on the development and employment of solar power stations and its beaming to the ground stations in the SHF band are put on the agenda. The most pressing problem is to develop orbital solar reflectors to illuminate towns in the polar regions, agricultural regions, and areas of processing sea products. Space-based technologies can be used to deal with typhoons, green house effects, and "ozone holes". Recently, large, frameless film structures formed by centrifugal forces offer the promise of structures for orbital power plants, reflectors, and solar sails. A big success is achieved in the development of power generating solar array elements of amorphous silicon. These innovations would make the development of orbital solar power plants dozens of times cheaper. Such solar arrays shall be used in the nearest future on heavy communication satellites and the Earth remote sensing platforms for generation of 140-160 kW at a specific power beyond 300 W/kg. The cargo traffic needed to develop and maintain the orbital power plants and reflector systems could be equipped with solar sails as the future low thrust propulsion. In 2000, the mankind witnessed an unexpected beginning of energy crisis along with strong hydro- meteorological events (typhoons, floods) that shocked the USA, the Western Europe, England, Japan, and other countries. The total damage is estimated as 90 billions of dollars. The mankind is approaching a boundary beyond which its further existence would depend on how people would learn to control weather and use ecologically safe power sources. Space technology base on the research potential accumulated in the previous century could serve for the solution of this problem.

  16. The symbol detachment problem.

    PubMed

    Pezzulo, Giovanni; Castelfranchi, Cristiano

    2007-06-01

    In situated and embodied approaches it is commonly assumed that the dynamics of sensorimotor engagement between an adaptive agent and its environment are crucial in understanding natural cognition. This perspective permits to address the symbol grounding problem, since the aboutness of any mental state arising during agent-environment engagement is guaranteed by their continuous coupling. However, cognitive agents are also able to formulate representations that are detached from the current state of affairs, such as expectations and goals. Moreover, they can act on their representations before--or instead of--acting directly on the environment, for example building the plan of a bridge and not directly the bridge. On the basis of representations, actions such as planning, remembering or imagining are possible that are disengaged from the current sensorimotor cycle, and often functional to future-oriented conducts. A new problem thus has to be acknowledged, the symbol detachment problem: how and why do situated agents develop representations that are detached from their current sensorimotor interaction, but nevertheless preserve grounding and aboutness? How do cognitive agents progressively acquire a range of capabilities permitting them to deal not only with the current situation but also with alternative, in particular future states of affairs? How do they develop the capability of acting on their representations instead of acting directly on the world? In a theoretical and developmental perspective, we propose that anticipation plays a crucial role in the detachment process: anticipatory representations, originally detached from the sensorimotor cycle for the sake of action control, are successively exapted for bootstrapping increasingly complex cognitive capabilities.

  17. The population problem?

    PubMed

    Mcelroy, W

    1968-01-01

    Most governments that have considered the population problem have been doing a part time job, working to stabilize the population by spreading knowledge of oral contraception (OC) and other contraceptive devices. An inadequate job is being done in promoting the reduction of the birthrate. What is needed is an all out effort from all countries concerned. It was only in 1965 that a President of the US for the 1st time made a positive statement about the government's position and support for family planning programs. Until then all government agencies were careful to avoid discussing this matter in opening meetings. Thereafter, President Johnson repeatedly indicated that he recognized the seriousness of the problem and the need for intelligent and direct action. Yet, the appropriation and distribution of funds for population control in the US and developing countries has failed to keep pace with the superlative statements made by national and responsible individuals on the importance of the problem. Family planning is more than a program just for the distribution of contraceptive devices. Where knowledgeable personnel are available, they try to identify the broad social problems resulting from large familles. They try to influence the behavior of the individual couples with regard to family size. Yet, even in the US the number of personnel is inadequate to carry out this large educational program. The Committee on Population of the National Academy of Sciences stressed several points: a zero rate of population growth may prove essential in the long run but as a goal within the time horizon of present policy it has little support in either the developed or developing countries, certainly not among governments; a need exists for exploration of a broader range of measures for their potential contribution to the easing of population pressures, particularly in the developing countries where rapid population growth is particularly threatening; programs of social change need

  18. Planning and Problem Solving

    DTIC Science & Technology

    1982-10-01

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

  19. Irrelevance in Problem Solving

    NASA Technical Reports Server (NTRS)

    Levy, Alon Y.

    1992-01-01

    The notion of irrelevance underlies many different works in AI, such as detecting redundant facts, creating abstraction hierarchies and reformulation and modeling physical devices. However, in order to design problem solvers that exploit the notion of irrelevance, either by automatically detecting irrelevance or by being given knowledge about irrelevance, a formal treatment of the notion is required. In this paper we present a general framework for analyzing irrelevance. We discuss several properties of irrelevance and show how they vary in a space of definitions outlined by the framework. We show how irrelevance claims can be used to justify the creation of abstractions thereby suggesting a new view on the work on abstraction.

  20. Problems of neural memory

    NASA Astrophysics Data System (ADS)

    Mikaelian, Andrei L.

    2005-01-01

    The paper considers the neural memory of the human brain from the viewpoint of visual information processing. A model that explains the principle of data recording and storing, memory relaxation, associative remembering and other memory functions is offered. The model of associative memory is based on the methods of holography, "wave biochemistry" and autowaves. Brief consideration is given to the associative properties of holographic neural structures and the memory architecture using running chemical reactions. The paper also outlines the problem of developing artificial memory elements for restoring the brain functions and possible interface devices for coupling neurons to electronic systems.

  1. Mechanics: Ideas, problems, applications

    NASA Astrophysics Data System (ADS)

    Ishlinskii, A. Iu.

    The book contains the published articles and reports by academician Ishlinskii which deal with the concepts and ideas of modern mechanics, its role in providing a general understanding of the natural phenomena, and its applications to various problems in science and engineering. Attention is given to the methodological aspects of mechanics, to the history of the theories of plasticity, friction, gyroscopic and inertial systems, and inertial navigation, and to mathematical methods in mechanics. The book also contains essays on some famous scientists and engineers.

  2. Cancer's Big Data Problem

    DOE PAGES

    Breaux, Justin H. S.

    2017-03-15

    The US Department of Energy (DOE) has partnered with the National Cancer Institute (NCI) to use DOE supercomputers to aid in the fight against cancer by building sophisticated models based on data available at the population, patient, and molecular levels. Here, through a three-year pilot project called the Joint Design of Advanced Computing Solutions for Cancer (JDACSC), four participating national laboratories--Argonne, Lawrence Livermore, Los Alamos, and Oak Ridge--will focus on three problems singled out by the NCI as the biggest bottlenecks to advancing cancer research.

  3. Management of foreskin problems.

    PubMed Central

    Lafferty, P M; MacGregor, F B; Scobie, W G

    1991-01-01

    One hundred consecutive cases of boys with foreskin problems referred to local paediatric surgeons in the Edinburgh area were studied. Fifty five underwent circumcision and the remainder were managed more conservatively with or without the use of local or general anaesthetic. Although sometimes avoiding general anaesthetic, the more conservative methods involved more frequent visits to the clinic, a larger number of complications, and a longer follow up period. Despite the vogue for conservatism, circumcision still has an important part to play in the management of troublesome foreskins in children. PMID:2053790

  4. Environmental problems of runners.

    PubMed

    Stanitski, C L

    1985-10-01

    By its very nature, running allows for a freedom that many athletic endeavors lack. The ability to run anytime and anywhere may be detrimental in itself, in that it may allow runners to place themselves in environmental circumstances that are unhealthy. Acclimatization to heat, altitude, and air pollution conditions can occur. Rapid changes in environment brought about by travel may lead to lack of recognition of appropriate clothing or running routes. Usual workout intensities and durations may not be appropriate for the specific environment at hand. Runners are advised to recognize the potential for such problems and make adjustments accordingly.

  5. Respiratory problems in acromegaly.

    PubMed

    Murrant, N J; Gatland, D J

    1990-01-01

    Death from respiratory causes in acromegaly is three times more common than in the general population and is most often the result of upper airways obstruction, although less commonly pulmonary dysfunction and disturbance of the central nervous system may occur. These factors may be found alone or in combination. Despite several reports of laryngeal involvement, upper airway obstruction in acromegaly is usually regarded as being due to macroglossia and pharyngeal soft tissue hypertrophy. We present four cases of acromegaly in which tracheostomy was required for laryngeal obstruction, with a review of the literature concerning the nature of respiratory problems in acromegaly.

  6. The nanostructure problem

    SciTech Connect

    Billinge, S.

    2010-03-22

    Diffraction techniques are making progress in tackling the difficult problem of solving the structures of nanoparticles and nanoscale materials. The great gift of x-ray crystallography has made us almost complacent in our ability to locate the three-dimensional coordinates of atoms in a crystal with a precision of around 10{sup -4} nm. However, the powerful methods of crystallography break down for structures in which order only extends over a few nanometers. In fact, as we near the one hundred year mark since the birth of crystallography, we face a resilient frontier in condensed matter physics: our inability to routinely and robustly determine the structure of complex nanostructured and amorphous materials. Knowing the structure and arrangement of atoms in a solid is so fundamental to understanding its properties that the topic routinely occupies the early chapters of every solid-state physics textbook. Yet what has become clear with the emergence of nanotechnology is that diffraction data alone may not be enough to uniquely solve the structure of nanomaterials. As part of a growing effort to incorporate the results of other techniques to constrain x-ray refinements - a method called 'complex modeling' which is a simple but elegant approach for combining information from spectroscopy with diffraction data to solve the structure of several amorphous and nanostructured materials. Crystallography just works, so we rarely question how and why this is so, yet understanding the physics of diffraction can be very helpful as we consider the nanostructure problem. The relationship between the electron density distribution in three dimensions (i.e., the crystal structure) and an x-ray diffraction pattern is well established: the measured intensity distribution in reciprocal space is the square of the Fourier transform of the autocorrelation function <{rho}(r){rho}(r+r')> of the electron density distribution {rho}(r). The fact that we get the autocorrelation function

  7. Cultivating Problem Solving Skills via a New Problem Categorization Scheme

    NASA Astrophysics Data System (ADS)

    Harper, Kathleen A.; Freuler, Richard J.; Demel, John T.

    2007-01-01

    When one looks at STEM disciplines as a whole, the need for effective problem solving skills is a commonality. However, studies indicate that the bulk of students who graduate from problem-solving intensive programs display little increase in their problem solving abilities. Also, there is little evidence for transfer of general skills from one subject area to another. Furthermore, the types of problems typically encountered in introductory STEM courses do not often cultivate the skills students will need when solving "real-world" problems. Initial efforts to develop and implement an interdisciplinary problem categorization matrix as a tool for instructional design are described. The matrix, which is independent of content, shows promise as a means for promoting useful problem-solving discussion among faculty, designing problem-solving intensive courses, and instructing students in developing real-world problem solving skills.

  8. Methodological Problems of Nanotechnoscience

    NASA Astrophysics Data System (ADS)

    Gorokhov, V. G.

    Recently, we have reported on the definitions of nanotechnology as a new type of NanoTechnoScience and on the nanotheory as a cluster of the different natural and engineering theories. Nanotechnology is not only a new type of scientific-engineering discipline, but it evolves also in a “nonclassical” way. Nanoontology or nano scientific world view has a function of the methodological orientation for the choice the theoretical means and methods toward a solution to the scientific and engineering problems. This allows to change from one explanation and scientific world view to another without any problems. Thus, nanotechnology is both a field of scientific knowledge and a sphere of engineering activity, in other words, NanoTechnoScience is similar to Systems Engineering as the analysis and design of large-scale, complex, man/machine systems but micro- and nanosystems. Nano systems engineering as well as Macro systems engineering includes not only systems design but also complex research. Design orientation has influence on the change of the priorities in the complex research and of the relation to the knowledge, not only to “the knowledge about something”, but also to the knowledge as the means of activity: from the beginning control and restructuring of matter at the nano-scale is a necessary element of nanoscience.

  9. Microchip problems plague DOD

    NASA Astrophysics Data System (ADS)

    Smith, R. J.

    1984-10-01

    The major issues in the controversy over the discovery of millions of defective microchips sold to the DOD by the Texas Instruments (TI) corporation are outlined. Defects in the microcircuits are blamed on inadequate testing procedures performed by TI during manufacture, and on inadequate testing procedures used by a subcontractor especially contracted to test the chips. Because the problem persisted over a period of years, defects might be possible in as many as 100 million chips used in a broad range of military applications including the Trident submarine, the B-52, B-1B, F-15, F-111, F-4, A-6, and A-7 aircraft, the Harpoon and HARM missile systems, and the Space Shuttles Discovery and Challenger. It is pointed out that although TI has accepted responsibility for the defective chips, little will be done by the DOD to compel the company to replace them, or to upgrade testing procedures. It is concluded that the serious nature of the problem could renew interest in recommendations for the standardization of military microcircuits.

  10. [Problems of laundry hygiene].

    PubMed

    Signorelli, C; Guasticchi, G

    1989-01-01

    As the bacteria found more frequently in hospital infections are the same found in the linen, it is speculated that hospital linens can contribute to the spread of nosocomial patologies. Nevertheless this consideration does not prove that linen constitutes a significant source for transmission of hospital infections, although some studies have strengthened this possibility. The hygienic problems of hospital linens washing have a great importance and in this contest the possibility of contagion throught infected sheets or overalls constitutes only a part of the question. The problem of the spreading of nosocomial infections has to be divided into (1) collection and arlage of the linens; and (2) their disinfection and washing. Collection and carriage need precautions to prevent the hospital staff and the patients from the direct contagion, while during the washing the infected, or potentially infected, linen are to be regarded as a potential risk, which can be avoided through a disinfection before the standard washing cycle. During the washing the processes of cleansing, the dilution and the effect of temperature could be sufficient to obtain the final results. The last consideration is linked to gestational aspects, that's to say the consumptions, the costs, the traditional organizing procedures and the alternative ones, such as the possibility of substituting disposable material to linens or to refer to central laundries placed outside the hospital building and independently operated.

  11. Touching the problem.

    PubMed

    Pendergast, M

    1999-01-01

    This article discusses the stand of the Catholic Church concerning HIV prevention through the use of condoms or any other forms of artificial contraception. It is a known fact that the problem of HIV/AIDS needs worldwide attention, and yet the Vatican rails against HIV prevention programs which appear to promote condom use. The primary intention to use condoms as one means to prevent the spread of HIV is not principally contraceptive. For not recognizing the integral yet complex relationship between different levels if HIV prevention and treatment and care responses, they confuse their opposition to artificial contraception with a higher principle and commitment to preserve life. With their criticism they fail to understand the fundamental principles of health promotion. In the struggle against HIV/AIDS, as with so many issues, the Catholic Church must engage with those who are touching the problem. It is also an opportunity to begin a proper dialogue wherein diversity can be celebrated, and values of responsible choices can be shared.

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

    ERIC Educational Resources Information Center

    Math Forum @ Drexel, 2009

    2009-01-01

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

  13. Abstraction and Problem Reformulation

    NASA Technical Reports Server (NTRS)

    Giunchiglia, Fausto

    1992-01-01

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

  14. The interactive effect of paternal problem drinking and maternal problem drinking on adolescent internalizing problems.

    PubMed

    Ohannessian, Christine McCauley

    2015-11-01

    This study examined the effects of both paternal problem drinking and maternal problem drinking on adolescent internalizing problems (depression and anxiety symptomatology). Surveys were administered to 566 10th and 11th grade students from the Mid-Atlantic region of the U.S. in the spring of 2007 and again in the spring of 2008. Although significant main effects were not observed, significant interactions were found between paternal problem drinking and maternal problem drinking for internalizing problems, especially for boys. In general, these interactions indicated that when paternal problem drinking was high, depression symptomatology and anxiety symptomatology were lower if maternal problem drinking was low. Findings from this study highlight the need to consider both paternal and maternal problem drinking when examining the effects that parental problem drinking may have on adolescent adjustment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Wicked Problem Solvers.

    PubMed

    Edmondson, Amy C

    2016-06-01

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

  16. The Brazil nut problem

    NASA Astrophysics Data System (ADS)

    Huerta, Dora; Ruiz-Suarez, Jesus

    2004-03-01

    The segregation of large intruders in a vertically vibrated granular bed is studied. We measure rising times a function of density, diameter and depth; for two different sinusoidal excitations. Our results shed definitive light to explain the fundamental aspects of the fascinating Brazil nut problem. At low frequencies (high amplitudes), inertia and convection are the only mechanisms behind segregation. Inertia dominates when the relative density of the intruder is greater than one and convection when it is less than one. At high frequencies (small amplitudes), where convection is suppressed, segregation occurs by buoyancy or sinkage. Finally, when the diameter of the intruders is changed, the well known paradigm "larger intruders rise faster" fails if the mass of the intruders is kept constant (while their relative densities are greater than one).

  17. The Password Problem

    SciTech Connect

    Walkup, Elizabeth

    2016-06-01

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

  18. [Hypersomnia: a diagnostic problem].

    PubMed

    Kranenburg, Guido; Teunissen, Laurien L

    2014-01-01

    Hypersomnia is a frequently occurring problem. When taking a medical history it is important to distinguish between fatigue and sleepiness. We present a 14-year-old girl with narcolepsy and a 59-year-old man with idiopathic hypersomnia. Features that are typical of narcolepsy are cataplexy and weight gain. Features that are typical of both narcolepsy and idiopathic hypersomnia are daytime naps, insomnia, sleep paralysis and hypnagogic hallucinations. Additional testing in patients with hypersomnia should include a polysomnography in order to exclude other sleeping disorders, and a mean sleep latency test. Practice shows that both patients with narcolepsy and those with idiopathic hypersomnia benefit from treatment with stimulating drugs such as modafinil.

  19. The Microchp Scheduling Problem

    NASA Astrophysics Data System (ADS)

    Bosman, M. G. C.; Bakker, V.; Molderink, A.; Hurink, J. L.; Smit, G. J. M.

    2009-08-01

    The increasing penetration of renewable energy sources, the demand for more energy efficient electricity production and the increase in distributed electricity generation causes a shift in the way electricity is produced and consumed. The downside of these changes in the electricity grid is that network stability and controllability becomes more difficult compared to the old situation. The new network has to accommodate various means of production, consumption and buffering and needs to offer control over the energy flows between these three elements. In order to offer such a control mechanism we need to know more about the individual aspects. In this paper we focus on the modelling of distributed production. Especially we look at the use of microCHP (Combined Heat and Power) appliances in a group of houses. The problem of planning the production runs of the microCHP is modelled via an ILP formulation both for a single house and for a group of houses.

  20. The unwitting sacrifice problem

    PubMed Central

    Gillett, G

    2005-01-01

    The diagnosis of bipolar disorder has been linked to giftedness of various sorts and this raises a special problem in that it is likely that the condition has a genetic basis. Therefore it seems possible that in the near future we will be able to detect and eliminate the gene predisposing to the disorder. This may mean, however, that, as a society, we lose the associated gifts. We might then face a difficult decision either way in that it is unclear that we are preventing an unalloyed bad when we diagnose and eliminate bipolar disorder through prenatal genetic testing and yet if we allow the individual to be born we are condemning that person to being an unwitting sacrifice in that they might well suffer considerable net distress as a result of our need to keep our gene pool enriched in the relevant way. PMID:15923479

  1. PROBLEMS OF HOMOSEXUALITY

    PubMed Central

    Reider, Norman

    1957-01-01

    Moral, religious and legal attitudes in attempts to control sexual behavior have interfered with a clear view of the medical and psychological aspects of homosexuality. This phenomenon is probably much less destructive of social aspects of our society and culture than is generally believed, since it is actually more widespread than is generally acknowledged. Homosexuality probably has hormonal and undoubtedly social and psychological factors, the latter of which are the only ones which can be worked with successfully in our present state of knowledge. A general practitioner's task is to aid those who wish and need help with this problem in finding psychiatric treatment in the same way that persons with any other emotional disturbance are referred. This should be carried out without bias just as with any other emotional disturbance. PMID:13426813

  2. Sleep problems in children.

    PubMed

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

    2013-10-01

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

  3. [Legionellosis, a tourist problem?].

    PubMed

    Kistler, W; Fleisch, F; Reinhart, W H; Wieland, T

    2002-07-31

    Legionellosis is a relatively rare disease characterized by an often prolonged and complicated course even in immunocompetent patients. Its diagnosis is mandatory for therapeutic and epidemiologic reasons. At the Kantonsspital Chur between 1998 and 2001, 6 cases of legionellosis have been observed: four of them were travel-associated and one concerned a local hotel employee. Due to the increasing international mobility epidemiologic investigations for the localization and elimination of the sources of infection are very difficult. A european task force, the European Working Group for Legionella Infections (EWGLI/www.ewgli.org) is addressing this problem. It is a matter of debate to what extent the public should be informed about sources of legionellosis (so called legionella hotels).

  4. The Inhibiting Bisection Problem

    SciTech Connect

    Pinar, Ali; Fogel, Yonatan; Lesieutre, Bernard

    2006-12-18

    Given a graph where each vertex is assigned a generation orconsumption volume, we try to bisect the graph so that each part has asignificant generation/consumption mismatch, and the cutsize of thebisection is small. Our motivation comes from the vulnerability analysisof distribution systems such as the electric power system. We show thatthe constrained version of the problem, where we place either the cutsizeor the mismatch significance as a constraint and optimize the other, isNP-complete, and provide an integer programming formulation. We alsopropose an alternative relaxed formulation, which can trade-off betweenthe two objectives and show that the alternative formulation of theproblem can be solved in polynomial time by a maximum flow solver. Ourexperiments with benchmark electric power systems validate theeffectiveness of our methods.

  5. Efficient Craig Interpolation for Linear Diophantine (Dis)Equations and Linear Modular Equations

    DTIC Science & Technology

    2008-02-01

    solution. Using theorem 9 there exists a row vector [R1, R2] such that R1A+ R2A ′ = 0 R1B +R2B′ 6= 0 In this case an interpolant for the pair (F,G) is the...some j, AX = B ∧A′X = B′ ⇒ C ′jX = D′j . Using theorem 8 there exists a row vector [R1, R2] such that R1A+ R2A ′ = C ′j R1B +R2B′ = D′j . In this case...case the interpolant will be a linear disequation. Using theorem 8 there exists a row vector [R1, R2] such that R1A+ R2A ′ = Ci R1B +R2B′ = Di Let VFG

  6. The worldwide "wildfire" problem.

    PubMed

    Gill, A Malcolm; Stephens, Scott L; Cary, Geoffrey J

    2013-03-01

    The worldwide "wildfire" problem is headlined by the loss of human lives and homes, but it applies generally to any adverse effects of unplanned fires, as events or regimes, on a wide range of environmental, social, and economic assets. The problem is complex and contingent, requiring continual attention to the changing circumstances of stakeholders, landscapes, and ecosystems; it occurs at a variety of temporal and spatial scales. Minimizing adverse outcomes involves controlling fires and fire regimes, increasing the resistance of assets to fires, locating or relocating assets away from the path of fires, and, as a probability of adverse impacts often remains, assisting recovery in the short-term while promoting the adaptation of societies in the long-term. There are short- and long-term aspects to each aspect of minimization. Controlling fires and fire regimes may involve fire suppression and fuel treatments such as prescribed burning or non-fire treatments but also addresses issues associated with unwanted fire starts like arson. Increasing the resistance of assets can mean addressing the design and construction materials of a house or the use of personal protective equipment. Locating or relocating assets can mean leaving an area about to be impacted by fire or choosing a suitable place to live; it can also mean the planning of land use. Assisting recovery and promoting adaptation can involve insuring assets and sharing responsibility for preparedness for an event. There is no single, simple, solution. Perverse outcomes can occur. The number of minimizing techniques used, and the breadth and depth of their application, depends on the geographic mix of asset types. Premises for policy consideration are presented.

  7. Computer Problem-Solving Coaches

    NASA Astrophysics Data System (ADS)

    Hsu, Leon; Heller, Kenneth

    2005-09-01

    Computers might be able to play an important role in physics instruction by coaching students to develop good problem-solving skills. Building on previous research on student problem solving and on designing computer programs to teach cognitive skills, we are developing a prototype computer coach to provide students with guided practice in solving problems. In addition to helping students become better problem solvers, such programs can be useful in studying how students learn to solve problems and how and if problem-solving skills can be transferred from a computer to a pencil-and-paper environment.

  8. Problem Solvers: Problem--How Long Can You Stand?

    ERIC Educational Resources Information Center

    Teaching Children Mathematics, 2010

    2010-01-01

    Healthy lifestyles are increasingly emphasized these days. This month the authors begin a series of mathematical problems that also address physical activity. They hope that these problems offer opportunities to investigate mathematics and also reinforce the desire to lead a healthy life. In their first problem of the academic year, students…

  9. Adolescent Problem Behavior and Problem Driving in Young Adulthood

    ERIC Educational Resources Information Center

    Bingham, C. Raymond; Shope, Jean T.

    2004-01-01

    Motor vehicle crashes are the leading cause of death among drivers younger than age 35, making problem driving behavior among young drivers a significant public concern. Effective intervention requires a better understanding of the antecedents of problem driving. Problem behavior theory, social control theory, and Kandel's model of substance use…

  10. Developing Metacognitive and Problem-Solving Skills through Problem Manipulation

    ERIC Educational Resources Information Center

    Parker Siburt, Claire J.; Bissell, Ahrash N.; Macphail, Richard A.

    2011-01-01

    In a collaborative effort between the our university's department of chemistry and the academic resource center, we designed a model for general chemistry recitation based on a problem manipulation method in which students actively assess the skills and knowledge used to answer a chemical problem and then manipulate the problem to create a new…

  11. Problem Solving through an Optimization Problem in Geometry

    ERIC Educational Resources Information Center

    Poon, Kin Keung; Wong, Hang-Chi

    2011-01-01

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

  12. Representations in Problem Solving: A Case Study with Optimization Problems

    ERIC Educational Resources Information Center

    Villegas, Jose L.; Castro, Enrique; Gutierrez, Jose

    2009-01-01

    Introduction: Representations play an essential role in mathematical thinking. They favor the understanding of mathematical concepts and stimulate the development of flexible and versatile thinking in problem solving. Here our focus is on their use in optimization problems, a type of problem considered important in mathematics teaching and…

  13. Problem Solving through an Optimization Problem in Geometry

    ERIC Educational Resources Information Center

    Poon, Kin Keung; Wong, Hang-Chi

    2011-01-01

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

  14. Representations in Problem Solving: A Case Study with Optimization Problems

    ERIC Educational Resources Information Center

    Villegas, Jose L.; Castro, Enrique; Gutierrez, Jose

    2009-01-01

    Introduction: Representations play an essential role in mathematical thinking. They favor the understanding of mathematical concepts and stimulate the development of flexible and versatile thinking in problem solving. Here our focus is on their use in optimization problems, a type of problem considered important in mathematics teaching and…

  15. Strengthening Programs through Problem Solving.

    ERIC Educational Resources Information Center

    Dyer, Jim

    1993-01-01

    Describes a secondary agricultural education program that was a dumping ground for academically disadvantaged students. Discusses how such a program can be improved by identifying problems and symptoms, treating problems, and goal setting. (JOW)

  16. Energy Problems and Environmental Concern

    ERIC Educational Resources Information Center

    Train, Russell E.

    1973-01-01

    Discusses problems encountered in energy extraction and consumption, involving nuclear power plant construction, environmental consequences of energy systems, and energy conservation ethics. Indicates that the increasing concern over environmental quality is not the true cause of present energy problems. (CC)

  17. Decision Analysis for Environmental Problems

    EPA Science Inventory

    Environmental management problems are often complex and uncertain. A formal process with proper guidance is needed to understand the issues, identify sources of disagreement, and analyze the major uncertainties in environmental problems. This course will present a process that fo...

  18. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1984-01-01

    The strategy of making a table is highlighted. A problem is given and the procedure for setting up and using the table are explained. Other suggestions for teaching problem solving are also included. (MNS)

  19. The Problem of Defining Intelligence.

    ERIC Educational Resources Information Center

    Lubar, David

    1981-01-01

    The major philosophical issues surrounding the concept of intelligence are reviewed with respect to the problems surrounding the process of defining and developing artificial intelligence (AI) in computers. Various current definitions and problems with these definitions are presented. (MP)

  20. Sherlock Holmes, Master Problem Solver.

    ERIC Educational Resources Information Center

    Ballew, Hunter

    1994-01-01

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

  1. Sherlock Holmes, Master Problem Solver.

    ERIC Educational Resources Information Center

    Ballew, Hunter

    1994-01-01

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

  2. Eldercare at Home: Mobility Problems

    MedlinePlus

    ... illnesses and lead to new ones such as circulatory problems including blood clots in the legs, further loss ... such as emphysema or infection, a stroke, depression, circulatory problems, or over-medication with sedatives or tranquillizers. It ...

  3. Dementia - behavior and sleep problems

    MedlinePlus

    ... gov/ency/patientinstructions/000029.htm Dementia - behavior and sleep problems To use the sharing features on this ... sleep and stay asleep Tips for Behavior and Sleep Problems Having a daily routine may help. Calmly ...

  4. Decision Analysis for Environmental Problems

    EPA Science Inventory

    Environmental management problems are often complex and uncertain. A formal process with proper guidance is needed to understand the issues, identify sources of disagreement, and analyze the major uncertainties in environmental problems. This course will present a process that fo...

  5. Strengthening Programs through Problem Solving.

    ERIC Educational Resources Information Center

    Dyer, Jim

    1993-01-01

    Describes a secondary agricultural education program that was a dumping ground for academically disadvantaged students. Discusses how such a program can be improved by identifying problems and symptoms, treating problems, and goal setting. (JOW)

  6. Energy Problems and Environmental Concern

    ERIC Educational Resources Information Center

    Train, Russell E.

    1973-01-01

    Discusses problems encountered in energy extraction and consumption, involving nuclear power plant construction, environmental consequences of energy systems, and energy conservation ethics. Indicates that the increasing concern over environmental quality is not the true cause of present energy problems. (CC)

  7. Enhancing chemistry problem-solving achievement using problem categorization

    NASA Astrophysics Data System (ADS)

    Bunce, Diane M.; Gabel, Dorothy L.; Samuel, John V.

    The enhancement of chemistry students' skill in problem solving through problem categorization is the focus of this study. Twenty-four students in a freshman chemistry course for health professionals are taught how to solve problems using the explicit method of problem solving (EMPS) (Bunce & Heikkinen, 1986). The EMPS is an organized approach to problem analysis which includes encoding the information given in a problem (Given, Asked For), relating this to what is already in long-term memory (Recall), and planning a solution (Overall Plan) before a mathematical solution is attempted. In addition to the EMPS training, treatment students receive three 40-minute sessions following achievement tests in which they are taught how to categorize problems. Control students use this time to review the EMPS solutions of test questions. Although problem categorization is involved in one section of the EMPS (Recall), treatment students who received specific training in problem categorization demonstrate significantly higher achievement on combination problems (those problems requiring the use of more than one chemical topic for their solution) at (p = 0.01) than their counterparts. Significantly higher achievement for treatment students is also measured on an unannounced test (p = 0.02). Analysis of interview transcripts of both treatment and control students illustrates a Rolodex approach to problem solving employed by all students in this study. The Rolodex approach involves organizing equations used to solve problems on mental index cards and flipping through them, matching units given when a new problem is to be solved. A second phenomenon observed during student interviews is the absence of a link in the conceptual understanding of the chemical concepts involved in a problem and the problem-solving skills employed to correctly solve problems. This study shows that explicit training in categorization skills and the EMPS can lead to higher achievement in complex problem

  8. Identifying and managing problem drinkers.

    PubMed Central

    Kahan, M.

    1996-01-01

    Problem drinking is far more common than severe alcohol dependence and is associated with considerable morbidity and health care costs. Whereas patients with alcohol dependence respond best to intensive treatment, one or more brief sessions of physician advice and counseling reduces alcohol consumption among problem drinkers. The two most useful tools to identify problem drinkers are the CAGE and the drinking problem question. PMID:8653034

  9. The lawnmower problem and other geometric path covering problems

    SciTech Connect

    Fekete, S.; Arkin, E.; Mitchell, J.

    1994-12-31

    We discuss the Lawnmower Problem: Given a polygonal region, find the shortest closed path along which we have to move a given object (typically a square or a circle), such that any point of the region will be covered by the object for some position of it movement. In another version of the problem, known as the Milling Problem, the object has to stay within the region at all times. Practical motivations for considering the Lawnmower Problem come from manufacturing (spray painting, quality control), geography (aerial surveys), optimization (tour planning for a large number of clients with limited mobility), and gardening. The Milling Problem has gained attention by its importance for NC pocket machining. We show that both problems are NP-hard and discuss approximation methods for various versions of the problem.

  10. Problems of rapid growth.

    PubMed

    Kim, T D

    1980-01-01

    South Korea's export-oriented development strategy has achieved a remarkable growth record, but it has also brought 2 different problems: 1) since the country's exports accounted for about 1% of total world export volume, the 1st world has become fearful about Korea's aggressive export drive; and 2) the fact that exports account for over 30% of its total gross national product (GNP) exposes the vulnerability of South Korea's economy itself. South Korea continues to be a poor nation, although it is rated as 1 of the most rapidly growing middle income economies. A World Bank 1978 report shows Korea to be 28th of 58 middle income countries in terms of per capita GNP in 1976. Of 11 newly industrializing countries (NIC), 5 in the European continent are more advanced than the others. A recent emphasis on the basic human needs approach has tended to downgrade the concept of GNP. Korea has only an abundant labor force and is without any natural resources. Consequently, Korea utilized an export-oriented development strategy. Oil requirements are met with imports, and almost all raw materials to be processed into exportable products must be imported. To pay import bills Korea must export and earn foreign exchange. It must be emphasized that foreign trade must always be 2-way traffic. In order to export more to middle income countries like Korea, the countries of the 1st world need to ease their protectionist measures against imports from developing countries.

  11. Large Spectral Library Problem

    SciTech Connect

    Chilton, Lawrence K.; Walsh, Stephen J.

    2008-10-03

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

  12. Postdatism -- a perinatal problem?

    PubMed

    Chhabra, S; Sood, S

    1990-01-01

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

  13. Crustal growth: Some major problems

    NASA Technical Reports Server (NTRS)

    Arculus, R. J.

    1988-01-01

    Fundamental problems with models currently used to explain the genesis and evolution of continental crust were raised. These problems focus around the difficulty of generating the upper continental crust from a lower crustal or mantle protolith without leaving a very large, and so far undetected, volume of restite. No conclusive resolution to the problems was achieved.

  14. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1984-01-01

    Presents a problem-solving activity in which students first guess and then check their answer. Also presents an activity to help students develop skill in understanding the question in a problem and a suggestion to help develop a classroom climate conducive to problem-solving. (JN)

  15. Migratory Farmworker Problems and Needs.

    ERIC Educational Resources Information Center

    McElroy, Robert C.

    Despite much publicity, hearings, legislative efforts, and other minor accomplishments in recent years, migrants are still one of the most disadvantaged and impoverished groups in the U.S. Among their problems is that they have neither the political, economic, nor other means of mitigating their problems. Some of their problems include uncertain…

  16. Problem Analysis: Challenging All Learners

    ERIC Educational Resources Information Center

    Garcia, Katie; Davis, Alicia

    2013-01-01

    In this article, Garcia and Davis describe problem analysis as the process of examining a given mathematics exercise to find ways in which the problem can be modified and extended to create a richer learning opportunity for students. Students are often reluctant to attempt what they perceive to be higher-order thinking problems, but problem…

  17. Problem Analysis: Challenging All Learners

    ERIC Educational Resources Information Center

    Garcia, Katie; Davis, Alicia

    2013-01-01

    In this article, Garcia and Davis describe problem analysis as the process of examining a given mathematics exercise to find ways in which the problem can be modified and extended to create a richer learning opportunity for students. Students are often reluctant to attempt what they perceive to be higher-order thinking problems, but problem…

  18. Problem Solving and Beginning Programming.

    ERIC Educational Resources Information Center

    McAllister, Alan

    Based on current models of problem solving within cognitive psychology, this study focused on the spontaneous problem solving strategies used by children as they first learned LOGO computer programming, and on strategy transformations that took place during the problem solving process. The research consisted of a six weeks programming training…

  19. Euler's Three-Body Problem.

    ERIC Educational Resources Information Center

    Wild, Walter J.

    1980-01-01

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

  20. Common Infant and Newborn Problems

    MedlinePlus

    It is hard when your baby is sick. Common health problems in babies include colds, coughs, fevers, and vomiting. Babies also commonly have skin problems, like diaper rash or cradle cap. Many of these problems are ... are worried about your baby, call your health care provider right away.

  1. Supporting Problem Solving in PBL

    ERIC Educational Resources Information Center

    Jonassen, David

    2011-01-01

    Although the characteristics of PBL (problem focused, student centered, self-directed, etc.) are well known, the components of a problem-based learning environment (PBLE) and the cognitive scaffolds necessary to support learning to solve different kinds of problems with different learners is less clear. This paper identifies the different…

  2. The Identity of Problem Solving

    ERIC Educational Resources Information Center

    Mamona-Downs, Joanna; Downs, Martin

    2005-01-01

    This paper raises issues motivated by considering the "identity" of problem solving. This means that we are concerned with how other mathematics education topics impinge on problem solving, and with themes that naturally arise within the problem-solving agenda. We claim that some of these issues need more attention by educational research, while…

  3. Technological Problem Solving: A Proposal.

    ERIC Educational Resources Information Center

    Waetjen, Walter B.

    Examination of newer technology education materials reveals two recurring themes: one relates to curriculum content, familiarizing students with technology, and another to a technique of classroom instruction, i.e., problem solving. A problem-solving framework for technical education has the following components: (1) define the problem; (2)…

  4. Development drilling problems offshore Malaysia

    SciTech Connect

    Osman, M.N.; Maung, M.

    1984-02-01

    This paper highlights the major drilling problems encountered in the field development programmes offshore Malaysia from 1978 to mid-1983. The major problems identified were pipe sticking which was common in all the areas and top hole drilling problems encountered in a few fields offshore Sabah and Sarawak. Generally, the problems were related to drilling deviated wells through the soft and unconsolidated formations common in this region. Preventive measures employed by the Contractors have been effective in overcoming these problems in the later years of the period under consideration.

  5. Screening for Problem Drinking

    PubMed Central

    Bradley, Katharine A; Bush, Kristen R; McDonell, Mary B; Malone, Timothy; Fihn, Stephan D

    1998-01-01

    OBJECTIVE To compare self-administered versions of three questionnaires for detecting heavy and problem drinking: the CAGE, the Alcohol Use Disorders Identification Test (AUDIT), and an augmented version of the CAGE. DESIGN Cross-sectional surveys. SETTING Three Department of Veterans Affairs general medical clinics. PATIENTS Random sample of consenting male outpatients who consumed at least 5 drinks over the past year (“drinkers”). Heavy drinkers were oversampled. MEASUREMENTS An augmented version of the CAGE was included in a questionnaire mailed to all patients. The AUDIT was subsequently mailed to “drinkers.” Comparison standards, based on the tri-level World Health Organization alcohol consumption interview and the Diagnostic Interview Schedule, included heavy drinking (>14 drinks per week typically or ≥5 drinks per day at least monthly) and active DSM-IIIR alcohol abuse or dependence (positive diagnosis and at least one alcohol-related symptom in the past year). Areas under receiver operating characteristic curves (AUROCs) were used to compare screening questionnaires. MAIN RESULTS Of 393 eligible patients, 261 (66%) returned the AUDIT and completed interviews. For detection of active alcohol abuse or dependence, the CAGE augmented with three more questions (AUROC 0.871) performed better than either the CAGE alone or AUDIT (AUROCs 0.820 and 0.777, respectively). For identification of heavy-drinking patients, however, the AUDIT performed best (AUROC 0.870). To identify both heavy drinking and active alcohol abuse or dependence, the augmented CAGE and AUDIT both performed well, but the AUDIT was superior (AUROC 0.861). CONCLUSIONS For identification of patients with heavy drinking or active alcohol abuse or dependence, the self-administered AUDIT was superior to the CAGE in this population. PMID:9669567

  6. A taxonomy of inductive problems.

    PubMed

    Kemp, Charles; Jern, Alan

    2014-02-01

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

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  8. Problem Reporting System

    NASA Technical Reports Server (NTRS)

    Potter, Don; Serian, Charles; Sweet, Robert; Sapir, Babak; Gamez, Enrique; Mays, David

    2008-01-01

    The Problem Reporting System (PRS) is a Web application, running on two Web servers (load-balanced) and two database servers (RAID-5), which establishes a system for submission, editing, and sharing of reports to manage risk assessment of anomalies identified in NASA's flight projects. PRS consolidates diverse anomaly-reporting systems, maintains a rich database set, and incorporates a robust engine, which allows tracking of any hardware, software, or paper process by configuring an appropriate life cycle. Global and specific project administration and setup tools allow lifecycle tailoring, along with customizable controls for user, e-mail, notifications, and more. PRS is accessible via the World Wide Web for authorized user at most any location. Upon successful log-in, the user receives a customizable window, which displays time-critical 'To Do' items (anomalies requiring the user s input before the system moves the anomaly to the next phase of the lifecycle), anomalies originated by the user, anomalies the user has addressed, and custom queries that can be saved for future use. Access controls exist depending on a user's role as system administrator, project administrator, user, or developer, and then, further by association with user, project, subsystem, company, or item with provisions for business-to-business exclusions, limitations on access according to the covert or overt nature of a given project, all with multiple layers of filtration, as needed. Reporting of metrics is built in. There is a provision for proxy access (in which the user may choose to grant one or more other users to view screens and perform actions as though they were the user, during any part of a tracking life cycle - especially useful during tight build schedules and vacations to keep things moving). The system also provides users the ability to have an anomaly link to or notify other systems, including QA Inspection Reports, Safety, GIDEP (Government-Industry Data Exchange Program

  9. [361 million problems].

    PubMed

    Livi Bacci, M

    1990-01-01

    changing from the basic subsistence and energy of Malthus's day, as are the factors of election and adaptation. In an increasingly interdependent world, the link between production and consumption of natural resources has become less obvious, so that signs of dangerous imbalances between population and resources may be overlooked. But the demographic problems of 1 region will increasingly affect all other regions.

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

    PubMed

    Schmidt, Jan C

    2011-06-01

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

  11. Resource Scarcity: Problems Technology Cannot Solve; Problems Technology Can Solve.

    ERIC Educational Resources Information Center

    Meadows, Dennis; Castle, Emery N.

    1979-01-01

    Lists resource problems technology can and cannot solve, and emphasizes the need for considering and restructuring the social environments and institutions as well as developing new technologies. (CK)

  12. Mathematical problem solving by analogy.

    PubMed

    Novick, L R; Holyoak, K J

    1991-05-01

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

  13. Diabetes and Sexual and Urologic Problems

    MedlinePlus

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

  14. Modeling Applied to Problem Solving

    NASA Astrophysics Data System (ADS)

    Pawl, Andrew; Barrantes, Analia; Pritchard, David E.

    2009-10-01

    Modeling Applied to Problem Solving (MAPS) is a pedagogy that helps students transfer instruction to problem solving in an expert-like manner. Declarative and Procedural syllabus content is organized and learned (not discovered) as a hierarchy of General Models. Students solve problems using an explicit Problem Modeling Rubric that begins with System, Interactions and Model (S.I.M.). System and Interactions are emphasized as the key to a strategic description of the system and the identification of the appropriate General Model to apply to the problem. We have employed the pedagogy in a three-week review course for students who received a D in mechanics. The course was assessed by a final exam retest as well as pre and post C-LASS surveys, yielding a one standard deviation improvement in the students' ability to solve final exam problems and a statistically significant positive shift in 7 of the 9 categories in the C-LASS.

  15. Vertex upgrading problems for VLSI

    SciTech Connect

    Paik, D.

    1991-01-01

    The author examines vertex modification (splitting, deleting and upgrading) problems that arise in VLSI CAD and other application areas. The problems he considers differ from previously studied vertex-deletion problems in that he is interested in modifying vertices in a dag so that the resulting dag has no path whose length exceeds a prespecified amount. Vertex-modification problems can be used to model the scan register placement problem in VLSI design, placement of signal boosters in lossy circuits, satellite uplink/downlink placement in communication networks, etc. The approach adopted is to first determine which of these problems are NP-hard. Pseudo polynomial time algorithms and fast heuristics for the NP-hard versions are explored. Fast polynomial time algorithms for other versions are developed. Experimentation using the ISCAS benchmark circuits are also performed.

  16. [Ethical problems in health care].

    PubMed

    Zácek, A

    1994-02-28

    Changes in the scale of values associated with society entering plural democracy caused as regards conceptual problems of health care some ethical doubts and objections. In the author's opinion the most important ones are: problems on the essence of health and mission of health policy, responsibility for health care, nature of health services under conditions of market economy, problems of the interpretation of right to health, health requirements and the importance of equity in advanced cultural societies.

  17. Aerodynamic Problems of Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Chou, Kyong Chol

    1984-09-01

    The airflow along the surface of a launch vehicle together with vase flow of clustered nozzles cause problems which may affect the stability or efficiency of the entire vehicle. The problem may occur when the vehicle is on the launching pad or even during flight. As for such problems, local steady-state loads, overall steady-state loads, buffet, ground wind loads, base heating and rocket-nozzle hinge moments are examined here specifically.

  18. Solving Transportation Problems via Aggregation,

    DTIC Science & Technology

    1984-07-01

    AD-A144 219 SOLVING TRANSPORTATION PROBLEMS VIA AGGREGATION (U) i/l GEORGIA INST OF TECH ATLANTA PRODUCTION AND DISTRIBUTION RESEARCH CENTER R W...10 July 1984 SOLVING TRANSPORTATION PROBLEMS VIA AGGREGATION by" 4 Richard W. Taylort C. M. Shettytt PDRC 84-10 DTIC E L - TE~ School of Business...c UoaOO48--17 Rpouto spritein whol or pr for ny prpos of he U S. overment Abstract Solving Transportation Problems Via Aggregation 0

  19. Problem Effectiveness in a Course Using Problem-Based Learning.

    ERIC Educational Resources Information Center

    Dolmans, Diana H. J. M.

    1993-01-01

    A University of Limburg (Netherlands) medical school study investigated the relationship between student-generated learning issues and faculty instructional objectives (i.e., the effectiveness of the problems posed) in a problem-centered obstetrics and child development curriculum. Subjects were 120 students and 12 faculty. Results indicated…

  20. Collaborative Everyday Problem Solving: Interpersonal Relationships and Problem Dimensions

    ERIC Educational Resources Information Center

    Strough, Jonell; Patrick, Julie Hicks; Swenson, Lisa M.; Cheng, Suling; Barnes, Kristi A.

    2003-01-01

    Older adults' preferred partners for collaborative everyday problem solving and the types of everyday problems solved alone and with others were examined in a sample of community dwelling older adults (N = 112, M age = 71.86 yrs., SD = 5.92 yrs.). Family members (i.e., spouses, adult children) were the most frequently nominated partners for…

  1. Problem Solving Style, Creative Thinking, and Problem Solving Confidence

    ERIC Educational Resources Information Center

    Houtz, John C.; Selby, Edwin C.

    2009-01-01

    Forty-two undergraduate and graduate students completed VIEW: An Assessment of Problem Solving Style, the non-verbal Torrance Test Thinking Creatively with Pictures, and the Problem Solving Inventory (PSI). VIEW assesses individuals' orientation to change, manner of processing, and ways of deciding, while the Torrance test measures several…

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

    ERIC Educational Resources Information Center

    Soltow, Willow

    1984-01-01

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

  3. Student Constructs of Mathematical Problems: Problem Types, Achievement and Gender

    ERIC Educational Resources Information Center

    Chiu, Mei-Shiu; Yeh, Huei-Ming; Whitebread, David

    2014-01-01

    This study aims to understand students' constructs regarding mathematical problems. Fifty-one Taiwanese primary students' constructs are elicited using interviews with the repertory grid technique based on their responses to creative and non-creative problems. The results of qualitative data analysis show that students' initial constructs can be…

  4. Problem Solvers: Problem--Jesse's Train

    ERIC Educational Resources Information Center

    James, Julie; Steimle, Alice

    2014-01-01

    Persevering in problem solving and constructing and critiquing mathematical arguments are some of the mathematical practices included in the Common Core State Standards for Mathematics (CCSSI 2010). To solve unfamiliar problems, students must make sense of the situation and apply current knowledge. Teachers can present such opportunities by…

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

    ERIC Educational Resources Information Center

    Moore, Kevin C.; Carlson, Marilyn P.

    2012-01-01

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

  6. Giant Story Problems: Reading Comprehension through Math Problem Solving.

    ERIC Educational Resources Information Center

    Goularte, Renee

    Primary students solve "oversized" story problems using drawings, equations, and written responses, helping them understand the links between the language of story problems and the numerical representations of matching equations. The activity also includes oral language and reflective writing, thus bringing together a variety of language…

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

    ERIC Educational Resources Information Center

    Soltow, Willow

    1984-01-01

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

  8. Student Constructs of Mathematical Problems: Problem Types, Achievement and Gender

    ERIC Educational Resources Information Center

    Chiu, Mei-Shiu; Yeh, Huei-Ming; Whitebread, David

    2014-01-01

    This study aims to understand students' constructs regarding mathematical problems. Fifty-one Taiwanese primary students' constructs are elicited using interviews with the repertory grid technique based on their responses to creative and non-creative problems. The results of qualitative data analysis show that students' initial constructs can be…

  9. Problem Solvers: Problem--Jesse's Train

    ERIC Educational Resources Information Center

    James, Julie; Steimle, Alice

    2014-01-01

    Persevering in problem solving and constructing and critiquing mathematical arguments are some of the mathematical practices included in the Common Core State Standards for Mathematics (CCSSI 2010). To solve unfamiliar problems, students must make sense of the situation and apply current knowledge. Teachers can present such opportunities by…

  10. The generalized pole assignment problem. [dynamic output feedback problems

    NASA Technical Reports Server (NTRS)

    Djaferis, T. E.; Mitter, S. K.

    1979-01-01

    Two dynamic output feedback problems for a linear, strictly proper system are considered, along with their interrelationships. The problems are formulated in the frequency domain and investigated in terms of linear equations over rings of polynomials. Necessary and sufficient conditions are expressed using genericity.

  11. Haplotyping Problem, A Clustering Approach

    SciTech Connect

    Eslahchi, Changiz; Sadeghi, Mehdi; Pezeshk, Hamid; Kargar, Mehdi; Poormohammadi, Hadi

    2007-09-06

    Construction of two haplotypes from a set of Single Nucleotide Polymorphism (SNP) fragments is called haplotype reconstruction problem. One of the most popular computational model for this problem is Minimum Error Correction (MEC). Since MEC is an NP-hard problem, here we propose a novel heuristic algorithm based on clustering analysis in data mining for haplotype reconstruction problem. Based on hamming distance and similarity between two fragments, our iterative algorithm produces two clusters of fragments; then, in each iteration, the algorithm assigns a fragment to one of the clusters. Our results suggest that the algorithm has less reconstruction error rate in comparison with other algorithms.

  12. Haplotyping Problem, A Clustering Approach

    NASA Astrophysics Data System (ADS)

    Eslahchi, Changiz; Sadeghi, Mehdi; Pezeshk, Hamid; Kargar, Mehdi; Poormohammadi, Hadi

    2007-09-01

    Construction of two haplotypes from a set of Single Nucleotide Polymorphism (SNP) fragments is called haplotype reconstruction problem. One of the most popular computational model for this problem is Minimum Error Correction (MEC). Since MEC is an NP-hard problem, here we propose a novel heuristic algorithm based on clustering analysis in data mining for haplotype reconstruction problem. Based on hamming distance and similarity between two fragments, our iterative algorithm produces two clusters of fragments; then, in each iteration, the algorithm assigns a fragment to one of the clusters. Our results suggest that the algorithm has less reconstruction error rate in comparison with other algorithms.

  13. Inverse problem in hydrogeology

    NASA Astrophysics Data System (ADS)

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

    2005-03-01

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

  14. Musculoskeletal problems of performing artists.

    PubMed

    Greer, J M; Panush, R S

    1994-02-01

    We have reviewed the frequency and variety of rheumatic problems among performing artists. For instrumentalists, injuries are related to the type of instrument played, the technique used and the effort expended in the quest for excellence. For dancers, musculoskeletal problems too reflect technique and effort. We should not be surprised at the frequency of these problems. Rheumatologists, as well as orthopaedic surgeons, physiotherapists, neurologists and other physicians, encounter performing artists as patients. We should be familiar with their problems and be able to knowledgeably diagnose and manage them. This may include observing the artist during actual performances. How is the instrument being held? What is the posture of the artist? What are the comments of the coach or teacher. What type of shoes does the ballerina wear? What movements in particular cause discomfort? These and similar observations will have direct bearing on the musculoskeletal problems of these artists. Published studies have related the variety, frequency and disabling nature of performance-related musculoskeletal problems. Unfortunately few if any of these are controlled, blinded or prospective. We need more and better information. We will want clear information about prevalence of problems, better definition of the musculoskeletal ailments, classification of the relationship of problems with performance and individual biomechanical features, information about response of specific problems to interventions, and data about the long-term consequences, if any, of these rheumatic problems to the musculoskeletal system. Artists as patients are unique. Minor problems can become potentially career-ending disabilities. Making music or performing dance may provide us with delightful entertainment but represents a source of livelihood to artists. Understanding their medical needs and enabling them to continue to perform is the challenge before us.

  15. Is the Drug Problem Soluble?

    ERIC Educational Resources Information Center

    Jonas, Steven

    1989-01-01

    Concludes that the principle drug problems in the United States arise from the use of cigarette tobacco and alcoholic beverages. Identifies a drug culture as the persistent force in society that promotes drug use. Points out that the influence of the primary drug industries inhibit attempts to deal effectively with drug problems. (KO)

  16. Is the Drug Problem Soluble?

    ERIC Educational Resources Information Center

    Jonas, Steven

    1989-01-01

    Concludes that the principle drug problems in the United States arise from the use of cigarette tobacco and alcoholic beverages. Identifies a drug culture as the persistent force in society that promotes drug use. Points out that the influence of the primary drug industries inhibit attempts to deal effectively with drug problems. (KO)

  17. Problem Solving, Scaffolding and Learning

    ERIC Educational Resources Information Center

    Lin, Shih-Yin

    2012-01-01

    Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

  18. Historical problem areas lessons learned

    NASA Technical Reports Server (NTRS)

    Sackheim, Bob; Fester, Dale A.

    1991-01-01

    Historical problem areas in space transportation propulsion technology are identified in viewgraph form. Problem areas discussed include materials compatibility, contamination, pneumatic/feed system flow instabilities, instabilities in rocket engine combustion and fuel sloshing, exhaust plume interference, composite rocket nozzle failure, and freeze/thaw damage.

  19. The Compound Atwood Machine Problem

    ERIC Educational Resources Information Center

    Coelho, R. Lopes

    2017-01-01

    The present paper accounts for progress in physics teaching in the sense that a problem, which has been closed to students for being too difficult, is gained for the high school curriculum. This problem is the compound Atwood machine with three bodies. Its introduction into high school classes is based on a recent study on the weighing of an…

  20. Learning Impasses in Problem Solving

    NASA Technical Reports Server (NTRS)

    Hodgson, J. P. E.

    1992-01-01

    Problem Solving systems customarily use backtracking to deal with obstacles that they encounter in the course of trying to solve a problem. This paper outlines an approach in which the possible obstacles are investigated prior to the search for a solution. This provides a solution strategy that avoids backtracking.

  1. How Social Problems Are Born.

    ERIC Educational Resources Information Center

    Glazer, Nathan

    1994-01-01

    Examines how social conditions can become social problems and argues that there are objective ways of determining the scale of a particular problem. The paper supports its argument through examinations of prohibition, the decline in tobacco consumption, and the war on drugs. (GLR)

  2. Representations of an Osmosis Problem.

    ERIC Educational Resources Information Center

    Zuckerman, June Trop

    1998-01-01

    Explores whether students with several years of high school science are able to represent an osmosis problem correctly. The study problem features a typical osmotic system with students expected to make a graph to show how the solution level in the stem of the funnel changes over time. (DDR)

  3. Geothermal Energy: Prospects and Problems

    ERIC Educational Resources Information Center

    Ritter, William W.

    1973-01-01

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

  4. Representations of an Osmosis Problem.

    ERIC Educational Resources Information Center

    Zuckerman, June Trop

    1998-01-01

    Explores whether students with several years of high school science are able to represent an osmosis problem correctly. The study problem features a typical osmotic system with students expected to make a graph to show how the solution level in the stem of the funnel changes over time. (DDR)

  5. The Problems of Human Environment.

    ERIC Educational Resources Information Center

    United Nations, New York, NY.

    Presented is a summary of considerations Specialized Agencies within the United Nations have given to the problems of the human environment. Uppermost are the problems of pollution--air, water, noise, marine, radiation, food, pesticide--as well as those of economic and social concern, environmental health, and misuse of the environment. Agencies…

  6. Problem Solving through Paper Folding

    ERIC Educational Resources Information Center

    Wares, Arsalan

    2014-01-01

    The purpose of this article is to describe a couple of challenging mathematical problems that involve paper folding. These problem-solving tasks can be used to foster geometric and algebraic thinking among students. The context of paper folding makes some of the abstract mathematical ideas involved relatively concrete. When implemented…

  7. Creative Thinking and Problem Solving.

    ERIC Educational Resources Information Center

    Lacy, Grace

    The booklet considers the nature of creativity in children and examines classroom implications. Among the topics addressed are the following: theories about creativity; research; developments in brain research; the creative process; creative problem solving; the Structure of Intellect Problem Solving (SIPS) model; a rationale for creativity in the…

  8. Identifying problem and compulsive gamblers.

    PubMed Central

    van Es, R.

    2000-01-01

    OBJECTIVE: To present a meta-analysis of current research on the prevalence, identification, and treatment of problem and compulsive gamblers. QUALITY OF EVIDENCE: Problem and compulsive gambling was not a socio-scientific concern until the last two decades. Hence research on this topic is limited. The summary and analysis for this paper relied on computer searches of journal and news abstracts in addition to direct contact with organizations addressing the identification and treatment of compulsive gamblers. MAIN MESSAGE: An estimated 5% of those who gamble run into problems. About 1% of those who gamble are predicted to experience serious problems. Successful treatment of problem and compulsive gambling continues to be a challenge. Although cognitive therapy has been the favoured approach, a combination of several therapeutic approaches is advocated. CONCLUSIONS: Problem and compulsive gambling can present a real health threat. As with other addictions, treatment strategies continue to be a baffling social problem. Aware and informed physicians can have a pivotal role in the difficult process of identifying, acknowledging, and remediating problem and compulsive gambling. PMID:10907572

  9. Difficulties in Genetics Problem Solving.

    ERIC Educational Resources Information Center

    Tolman, Richard R.

    1982-01-01

    Examined problem-solving strategies of 30 high school students as they solved genetics problems. Proposes a new sequence of teaching genetics based on results: meiosis, sex chromosomes, sex determination, sex-linked traits, monohybrid and dihybrid crosses (humans), codominance (humans), and Mendel's pea experiments. (JN)

  10. Addressing problems in complete dentures.

    PubMed

    LaBarre, Eugene; Giusti, Lola; Pitigoi-Aron, Gabriela

    2007-10-01

    The authors have compiled a set of solutions to the most common issues influencing the success of complete denture cases. A brief review and discussion of occlusal vertical dimension is presented, followed by a troubleshooting guide to problems such as inadequate retention and stability, discomfort, and other problems affecting treatment outcome.

  11. Problems of the Digestive System

    MedlinePlus

    ... ASKED QUESTIONS FAQ120 WOMEN’S HEALTH Problems of the Digestive System • What are some common digestive problems? • What is ... of hormones during pregnancy can slow down the digestive system. How can constipation be treated? If constipation continues, ...

  12. Students' Problem Solving and Justification

    ERIC Educational Resources Information Center

    Glass, Barbara; Maher, Carolyn A.

    2004-01-01

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

  13. A Problem on Optimal Transportation

    ERIC Educational Resources Information Center

    Cechlarova, Katarina

    2005-01-01

    Mathematical optimization problems are not typical in the classical curriculum of mathematics. In this paper we show how several generalizations of an easy problem on optimal transportation were solved by gifted secondary school pupils in a correspondence mathematical seminar, how they can be used in university courses of linear programming and…

  14. Minimum Cuts and Related Problems.

    DTIC Science & Technology

    The paper is concerned with an integer programming characterization of a cut in a network. This characterization provides a fundamental equivalence...between directed pseudosummetric networks and undirected networks. It also identifies a class of problems which can be solved as minimum cut problems on a network. (Author)

  15. Creative Thinking and Problem Solving.

    ERIC Educational Resources Information Center

    Lacy, Grace

    The booklet considers the nature of creativity in children and examines classroom implications. Among the topics addressed are the following: theories about creativity; research; developments in brain research; the creative process; creative problem solving; the Structure of Intellect Problem Solving (SIPS) model; a rationale for creativity in the…

  16. Pen Pals: Practicing Problem Solving

    ERIC Educational Resources Information Center

    Lampe, Kristen A.; Uselmann, Linda

    2008-01-01

    This article describes a semester-long pen-pal project in which preservice teachers composed mathematical problems and the middle school students worked for solutions. The college students assessed the solution and the middle school students provided feedback regarding the problem itself. (Contains 6 figures.)

  17. Good Boys Are Problems Too!

    ERIC Educational Resources Information Center

    Warren, Simon

    2003-01-01

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

  18. Quantitative Reasoning in Problem Solving

    ERIC Educational Resources Information Center

    Ramful, Ajay; Ho, Siew Yin

    2015-01-01

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

  19. Problem Solving & Comprehension. Fourth Edition.

    ERIC Educational Resources Information Center

    Whimbey, Arthur; Lochhead, Jack

    This book shows how to increase one's power to analyze and comprehend problems. First, it outlines and illustrates the methods that good problem solvers use in attacking complex ideas. Then it gives some practice in applying these methods to a variety of questions in comprehension and reasoning. Chapters include: (1) "Test Your Mind--See How…

  20. The Problems of Human Environment.

    ERIC Educational Resources Information Center

    United Nations, New York, NY.

    Presented is a summary of considerations Specialized Agencies within the United Nations have given to the problems of the human environment. Uppermost are the problems of pollution--air, water, noise, marine, radiation, food, pesticide--as well as those of economic and social concern, environmental health, and misuse of the environment. Agencies…

  1. How Social Problems Are Born.

    ERIC Educational Resources Information Center

    Glazer, Nathan

    1994-01-01

    Examines how social conditions can become social problems and argues that there are objective ways of determining the scale of a particular problem. The paper supports its argument through examinations of prohibition, the decline in tobacco consumption, and the war on drugs. (GLR)

  2. Problem Behaviors & Tourette Syndrome. Revised.

    ERIC Educational Resources Information Center

    Bruun, Ruth Dowling; And Others

    This pamphlet discusses behavioral problems which are sometimes associated with Tourette Syndrome (TS), along with suggestions for parents to help manage these behaviors. Consideration is given to the following problems: obsessive-compulsive symptoms; attention deficit hyperactivity disorder; aggressive and explosive behaviors; self-injurious…

  3. Do TEFL Articles Solve Problems?

    ERIC Educational Resources Information Center

    Edge, Julian

    1985-01-01

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

  4. A Personal Problem Solving Inventory.

    ERIC Educational Resources Information Center

    Heppner, P. Paul; Petersen, Chris H.

    Few studies have explicitly attended to the personal problem-solving process within the counseling literature, perhaps due in part to the dearth of relevant assessment instruments. To examine the dimensions underlying the applied problem-solving process, an exploratory factor analysis was conducted using data collected from four samples of college…

  5. Mathematical Problems Concerning Rhythmic Processes

    DTIC Science & Technology

    1990-09-30

    experimental on forced chains oscillators, motivated by problems concerning the lamprey CPG for undulatory locomotion. Work continued with K. Sivard on...problems concerning the lamprey CPG for undulatory locomotion [1,2]. Work continued with K. Sigvard on interpretation of experiment, and we are preparing

  6. Difficulties in Genetics Problem Solving.

    ERIC Educational Resources Information Center

    Tolman, Richard R.

    1982-01-01

    Examined problem-solving strategies of 30 high school students as they solved genetics problems. Proposes a new sequence of teaching genetics based on results: meiosis, sex chromosomes, sex determination, sex-linked traits, monohybrid and dihybrid crosses (humans), codominance (humans), and Mendel's pea experiments. (JN)

  7. Problem Based Learning: Mystery Disease.

    ERIC Educational Resources Information Center

    Bohland, Mark A.

    This guide features a problem-based learning (PBL) unit specifically designed for student-centered learning of new and meaningful content on diseases. Students grapple with a complex and changing problem that requires higher level thinking skills in an environment in which students work both individually and in collaboration with others. Includes…

  8. Problem Solving, Scaffolding and Learning

    ERIC Educational Resources Information Center

    Lin, Shih-Yin

    2012-01-01

    Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

  9. The Future Problem Solving Program.

    ERIC Educational Resources Information Center

    Crabbe, Anne B.

    1989-01-01

    Describes the Future Problem Solving Program, in which students from the U.S. and around the world are tackling some complex challenges facing society, ranging from acid rain to terrorism. The program uses a creative problem solving process developed for business and industry. A sixth-grade toxic waste cleanup project illustrates the process.…

  10. The Persistent Problems of Education.

    ERIC Educational Resources Information Center

    Woodring, Paul

    Because discussions of educational problems seem to be retracing the same paths and problems, there is need to identify and define the enduring controversies in education and explore reasons for their currency. These issues are discussed in a historical context. The questions of what sort of education is of most worth and what subjects should be…

  11. Open problems in artificial life.

    PubMed

    Bedau, M A; McCaskill, J S; Packard, N H; Rasmussen, S; Adami, C; Green, D G; Ikegami, T; Kaneko, K; Ray, T S

    2000-01-01

    This article lists fourteen open problems in artificial life, each of which is a grand challenge requiring a major advance on a fundamental issue for its solution. Each problem is briefly explained, and, where deemed helpful, some promising paths to its solution are indicated.

  12. Promote Problem-Solving Discourse

    ERIC Educational Resources Information Center

    Bostic, Jonathan; Jacobbe, Tim

    2010-01-01

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

  13. Geothermal Energy: Prospects and Problems

    ERIC Educational Resources Information Center

    Ritter, William W.

    1973-01-01

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

  14. Pen Pals: Practicing Problem Solving

    ERIC Educational Resources Information Center

    Lampe, Kristen A.; Uselmann, Linda

    2008-01-01

    This article describes a semester-long pen-pal project in which preservice teachers composed mathematical problems and the middle school students worked for solutions. The college students assessed the solution and the middle school students provided feedback regarding the problem itself. (Contains 6 figures.)

  15. The Cereal Box Problem Revisited.

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.

    1999-01-01

    Investigates the cereal box problem using both an experimental and theoretical framework, and Monte Carlo methods. Using empirical data, students can discover patterns and relationships that help them understand the origin of the theoretical solution to the problem. Contains 17 references. (Author/ASK)

  16. The compound Atwood machine problem

    NASA Astrophysics Data System (ADS)

    Lopes Coelho, R.

    2017-05-01

    The present paper accounts for progress in physics teaching in the sense that a problem, which has been closed to students for being too difficult, is gained for the high school curriculum. This problem is the compound Atwood machine with three bodies. Its introduction into high school classes is based on a recent study on the weighing of an Atwood machine.

  17. The three-body problem.

    PubMed

    Musielak, Z E; Quarles, B

    2014-06-01

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

  18. Trigonometric problem cases well solved

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    2001-10-01

    Content of the book are trigonometric problems that can be found scarely in the technical literature. It begins with using trigonometric functions to horizon and height. Interesting pure mathematical problems about tangent, inscribed tetragon and parallelogram follow. In chapter 6 is a generalization of Euclid's theorem fo the right-angled triangle. The next themes are exterior circle and incircle. In chapter 9 an unusual proof of the cosine law for sides is given. Further treated problems are the distance of two stars and eclipses. The aim group consists of mathematicians, natural scientists and technicians(also teacher) who have to do professionally with trigonometric problems and (or)who are interested in trigonometric problems. There is an english and a german edition.

  19. Ten Problems in Experimental Mathematics

    SciTech Connect

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

    2004-09-30

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

  20. Sediment problems in urban areas

    USGS Publications Warehouse

    Guy, Harold P.

    1970-01-01

    One obstacle to a scientific recognition and an engineering solution to sediment-related environmental problems is that such problems are bound in conflicting and generally undefinable political and institutional restraints. Also, some of the difficulty may involve the fact that the scientist or engineer, because of his relatively narrow field of investigation, cannot always completely envision the less desirable effects of his work and communicate alternative solutions to the public. For example, the highway and motor-vehicle engineers have learned how to provide the means by which one can transport himself from one point to another with such great efficiency that a person's employment in this country is now commonly more than 5 miles from his residence. However, providing such efficient personal transport has created numerous serious environmental problems. Obstacles to recognition of and action to control sediment problems in and around urban areas are akin to other environmental problems with respect to the many scientific, engineering, economic, and social aspects.

  1. Some problems on the classical n-body problem

    NASA Astrophysics Data System (ADS)

    Albouy, Alain; Cabral, Hildeberto E.; Santos, Alan A.

    2012-08-01

    Our idea is to imitate Smale's list of problems, in a restricted domain of mathematical aspects of Celestial Mechanics. All the problems are on the n-body problem, some with different homogeneity of the potential, addressing many aspects such as central configurations, stability of relative equilibrium, singularities, integral manifolds, etc. Following Steve Smale in his list, the criteria for our selection are: (1) Simple statement. Also preferably mathematically precise, and best even with a yes or no answer. (2) Personal acquaintance with the problem, having found it not easy. (3) A belief that the question, its solution, partial results or even attempts at its solution are likely to have great importance for the development of the mathematical aspects of Celestial Mechanics.

  2. Optimization and geophysical inverse problems

    SciTech Connect

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

    2000-10-01

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

  3. Problem solving stages in the five square problem

    PubMed Central

    Fedor, Anna; Szathmáry, Eörs; Öllinger, Michael

    2015-01-01

    According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight, and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviorally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. Our participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and some of them also had the possibility of reporting impasse while working on the task. We found that the majority of participants did not follow the classic four-stage model of insight, but had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model is not sufficient to describe variability on the individual level. We revised the classic model and we provide a new model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviorally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behavior to verify insight theory. PMID:26300794

  4. Problem solving stages in the five square problem.

    PubMed

    Fedor, Anna; Szathmáry, Eörs; Öllinger, Michael

    2015-01-01

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

  5. Civil law problems and morbidity

    PubMed Central

    Pleasence, P; Balmer, N; Buck, A; O'Grady, A; Genn, H

    2004-01-01

    Study objective: In the United Kingdom, recognition of the links between social and health problems has led to government initiatives such as health action zones. The principles of civil law apply to many types of social problem, and the civil justice system provides one means through which they can be tackled. However, little research has been undertaken into the particular links between problems to which civil legal principles and processes can be applied and morbidity. This study examines these links, and the role of legal advice and services in preventing ill health. Design: This study examined survey respondents' self reports of longstanding illness/disability and experience of 18 problems to which legal principles can be applied. Setting: A random national survey conducted across England and Wales. Participants: 5611 adults drawn from 3348 residential households. Main results: Significant associations were found between illness/disability and 13 of the problem types. Moreover, experience of greater numbers of problems increased the likelihood of reported illness/disability. In attempting to resolve problems respondents' health also frequently suffered. Conclusions: This study highlights the contribution that public legal education and legal advice can make to the promotion of public health, and the importance of further integration of health and civil justice initiatives through health action zones, community legal service partnerships, etc, to further this end. PMID:15194714

  6. Gender, gambling and problem gambling.

    PubMed

    Hraba, J; Lee, G

    1996-03-01

    With data from a 1989 Iowa survey (N=1,011), adult male and female respondents are compared on their problem gambling, its correlates, as well as their gambling behavior. Gambling behavior means its scope, frequency, wagering and leisure time spent at gambling. Women's gambling behavior was lower than that of men, due to their having a narrower scope of gambling behavior, but the genders were not significantly different on frequency, wagering and time spent at gambling. Women and men did not differ significantly on problem gambling. Problem gambling is measured as loss of control over gambling, and consequences due to gambling as well as gambling behavior. Women and men did differ significantly, however, on several predictors of problem gambling. Women's estrangement from a conventional lifestyle and integration into a social world of gambling appeared to help explain their problem gambling. Alcohol consumption appeared to be a more important predictor for men than women. The genders shared the attitude that the odds can be beat as well as being big spenders as predictors of their problem gambling. The results are interpreted with practitioners' efforts to prevent and treat problem gambling in mind.

  7. Periodically specified satisfiability problems: An alternative to domino problems

    SciTech Connect

    Marathe, M.V.; Rosenkrantz, D.J.; Stearns, R.E.

    1997-02-01

    The authors characterize the complexities of several basic generalized CNF satisfiability problems SAT(S), when instances are specified using various kinds of 1- and 2-dimensional periodic specifications. They outline how this characterization can be used to prove a number of new hardness results for the complexity classes DSPACE(n), NSPACE(n), DEXPTIME, NEXPTIME, EXPSPACE etc. The hardness results presented significantly extend the known hardness results for periodically specified problems. Several advantages are outlined of the use of periodically specified satisfiability problems over the use of domino problems in proving both hardness and easiness results. As one corollary, the authors show that a number of basic NP-hard problems become EXPSPACE-hard when inputs are represented using 1-dimensional infinite periodic wide specifications. This answers a long standing open question posed by Orlin. The results can also be used as starting points for proving the hardness of a number of combinatorial problems when instances are specified succinctly using various succinct specifications. These results significantly extend the results of earlier research in this area.

  8. The Soccer-Ball Problem

    NASA Astrophysics Data System (ADS)

    Hossenfelder, Sabine

    2014-07-01

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

  9. [Basic problems of medical ethics].

    PubMed

    Herms, E

    1988-03-01

    The discussion on ethical problems in reproductive medicine that has been going on for quite a decade, is of an exemplary nature; it is mainly focussed on extracorporeal fertilisation, prenatal diagnosis with a view to abortion, and post partum diagnosis and treatment of genetic diseases. The fundamental problems of medical ethics in general come to the fore particularly clearly in this discussion. The following article deals with these fundamental problems, whereas a subsequent article will be concerned in greater detail with the three special disciplines I have just mentioned.

  10. Customer-centered problem solving.

    PubMed

    Samelson, Q B

    1999-11-01

    If there is no single best way to attract new customers and retain current customers, there is surely an easy way to lose them: fail to solve the problems that arise in nearly every buyer-supplier relationship, or solve them in an unsatisfactory manner. Yet, all too frequently, companies do just that. Either we deny that a problem exists, we exert all our efforts to pin the blame elsewhere, or we "Band-Aid" the problem instead of fixing it, almost guaranteeing that we will face it again and again.

  11. Nutritional Problems Affecting Older Adults.

    PubMed

    Crogan, Neva L

    2017-09-01

    Nutritional problems, such as malnutrition, dehydration, and electrolyte imbalance, are multifaceted and complex issues for older adults. This article describes these potential nutritional problems and then discusses evidence-based assessment strategies and treatment modalities that target these problems. Micronutrient deficiency is explored and evidence-based supplementation discussed. Many factors contribute to weight loss and malnutrition in older adults. These factors are classified as social, psychological, and/or biological. Addressing these issues and the influence of oral health on food intake are imperative to enhancing the overall quality of life for older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Problems in nonlinear resistive MHD

    SciTech Connect

    Turnbull, A.D.; Strait, E.J.; La Haye, R.J.; Chu, M.S.; Miller, R.L.

    1998-12-31

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

  13. General aviation IFR operational problems

    NASA Technical Reports Server (NTRS)

    Bolz, E. H.; Eisele, J. E.

    1979-01-01

    Operational problems of general aviation IFR operators (particularly single pilot operators) were studied. Several statistical bases were assembled and utilized to identify the more serious problems and to demonstrate their magnitude. These bases include official activity projections, historical accident data and delay data, among others. The GA operating environment and cockpit environment were analyzed in detail. Solutions proposed for each of the problem areas identified are based on direct consideration of currently planned enhancements to the ATC system, and on a realistic assessment of the present and future limitations of general aviation avionics. A coordinated set of research program is suggested which would provide the developments necessary to implement the proposed solutions.

  14. Robot, computer problem solving system

    NASA Technical Reports Server (NTRS)

    Becker, J. D.

    1972-01-01

    The development of a computer problem solving system is reported that considers physical problems faced by an artificial robot moving around in a complex environment. Fundamental interaction constraints with a real environment are simulated for the robot by visual scan and creation of an internal environmental model. The programming system used in constructing the problem solving system for the simulated robot and its simulated world environment is outlined together with the task that the system is capable of performing. A very general framework for understanding the relationship between an observed behavior and an adequate description of that behavior is included.

  15. [Ethical problems in organ transplantation].

    PubMed

    Valenta, J; Treska, V; Hasman, D

    1999-02-01

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

  16. Understanding Heart Valve Problems and Causes

    MedlinePlus

    ... affecting the aortic valve, and can lead to aortic stenosis . Mediastinal radiation therapy (radiation to the chest) – Studies ... Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - ...

  17. Corrosion Problems in Absorption Chillers

    ERIC Educational Resources Information Center

    Stetson, Bruce

    1978-01-01

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

  18. Eldercare at Home: Skin Problems

    MedlinePlus

    ... body oil, or moisturizer that is high in petroleum (AquaphorTM, EucerinTM). Avoid moisturizers with perfume or alcohol ... or DoveTM. Make sure you rinse well. Use petroleum jelly For problem dry spots, apply petroleum jelly ...

  19. Corrosion Problems in Absorption Chillers

    ERIC Educational Resources Information Center

    Stetson, Bruce

    1978-01-01

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

  20. Spectral methods for discontinuous problems

    NASA Technical Reports Server (NTRS)

    Abarbanel, S.; Gottlieb, D.; Tadmor, E.

    1985-01-01

    Spectral methods yield high-order accuracy even when applied to problems with discontinuities, though not in the sense of pointwise accuracy. Two different procedures are presented which recover pointwise accurate approximations from the spectral calculations.

  1. Enteral nutrition - child - managing problems

    MedlinePlus

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

  2. Chemical Educators Mull Problems, Needs

    ERIC Educational Resources Information Center

    O'Sullivan, Dermot A.

    1977-01-01

    Discusses the international symposium on chemical education held in Ljubljana, Yugoslavia, August, 1977. Included are the symposium's recommendations for future international action relating to the problems and needs of chemical education. (SL)

  3. Student Problem-Solving Behaviors

    NASA Astrophysics Data System (ADS)

    Harper, Kathleen A.

    2006-04-01

    Kathy Harper is director of undergraduate curriculum development in the physics department at The Ohio State University. She has been involved in local and national workshops for in-service teachers and conducts research in student problem solving.

  4. Warning Signs of Breastfeeding Problems

    MedlinePlus

    ... Breastfeeding Crying & Colic Diapers & Clothing Feeding & Nutrition Preemie Sleep Teething & Tooth Care Toddler Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Baby > Breastfeeding > Warning Signs of Breastfeeding Problems Ages & ...

  5. Special Medical Problems of Athletes.

    ERIC Educational Resources Information Center

    Couch, Joan M.

    1987-01-01

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

  6. Administrative Problems of Early Immersion.

    ERIC Educational Resources Information Center

    McGillivray, W. R.

    1978-01-01

    Administrative problems that have been solved or accepted during eight years of early immersion programs are discussed including choosing locations, staffing, costs, logistics, and the need for suitable pupil progress reporting. (JMF)

  7. Solving a problem by analogy

    NASA Astrophysics Data System (ADS)

    Easton, Don

    1999-03-01

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

  8. Late Blooming or Language Problem?

    MedlinePlus

    ... and Swallowing / Disorders and Diseases Late Blooming or Language Problem? Parents are smart. They listen to their ... or not their child is developing speech and language at a normal rate. If parents think that ...

  9. Quantum Computing: Solving Complex Problems

    ScienceCinema

    DiVincenzo, David [IBM Watson Research Center

    2016-07-12

    One of the motivating ideas of quantum computation was that there could be a new kind of machine that would solve hard problems in quantum mechanics. There has been significant progress towards the experimental realization of these machines (which I will review), but there are still many questions about how such a machine could solve computational problems of interest in quantum physics. New categorizations of the complexity of computational problems have now been invented to describe quantum simulation. The bad news is that some of these problems are believed to be intractable even on a quantum computer, falling into a quantum analog of the NP class. The good news is that there are many other new classifications of tractability that may apply to several situations of physical interest.

  10. Eldercare at Home: Memory Problems

    MedlinePlus

    ... do by themselves." These activities, especially those involving music, can be especially therapeutic. Encourage regular routines. Important ... problem was due to a physical illness or depression, treatment is likely to improve memory. There are ...

  11. Systems management techniques and problems

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Report is reviewed which discusses history and trends of systems management, its basic principles, and nature of problems that lend themselves to systems approach. Report discusses systems engineering as applied to weapons acquisition, ecology, patient monitoring, and retail merchandise operations.

  12. Special Medical Problems of Athletes.

    ERIC Educational Resources Information Center

    Couch, Joan M.

    1987-01-01

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

  13. The unsolved problems of neuroscience

    PubMed Central

    Adolphs, Ralph

    2015-01-01

    Some problems in neuroscience are nearly solved. For others, solutions are decades away. The current pace of advances in methods forces us to take stock, to ask where we are going, and what we should research next. PMID:25703689

  14. Problems in Recording the Electrocardiogram.

    ERIC Educational Resources Information Center

    Webster, John G.

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

  15. Problem Solving with General Semantics.

    ERIC Educational Resources Information Center

    Hewson, David

    1996-01-01

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

  16. Dental Health and Orthodontic Problems

    MedlinePlus

    ... patients is cosmetic. Beside the traditional silver-colored metal alloy used to fill cavities, a composite material ... Orthodontic Problems are Treated If you were a “metal mouth” as a teenager, you’ll immediately notice ...

  17. The Mind-Body Problem.

    ERIC Educational Resources Information Center

    Fodor, Jerry A.

    1981-01-01

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

  18. Surrogate Guderley Test Problem Definition

    SciTech Connect

    Ramsey, Scott D.; Shashkov, Mikhail J.

    2012-07-06

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

  19. Controversies in Obstetrics: Dermatologic Problems

    PubMed Central

    Barber, Kirk A.

    1988-01-01

    Skin disease in pregnancy generally produces increased concern among attending physicians. Not only is the diagnosis often a problem but the safety of the therapy may also be a concern. The author of this article presents three common skin problems and their treatments to illustrate the general principles used in diagnosis and treatment of skin disease during pregnancy. ImagesFigure 1Figure 2 PMID:21253230

  20. [Problems of bilinguism in psychotherapy].

    PubMed

    Fadda, S; Müller, C

    1978-01-01

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

  1. Inversion Algorithms for Geophysical Problems

    DTIC Science & Technology

    1987-12-16

    ktdud* Sccumy Oass/Kjoon) Inversion Algorithms for Geophysical Problems (U) 12. PERSONAL AUTHOR(S) Lanzano, Paolo 13 «. TYPE OF REPORT Final 13b...spectral density. 20. DISTRIBUTION/AVAILABILITY OF ABSTRACT 13 UNCLASSIFIED/UNLIMITED D SAME AS RPT n OTIC USERS 22a. NAME OF RESPONSIBLE...Research Laboratory ’^^ SSZ ’.Washington. DC 20375-5000 NRLrMemorandum Report-6138 Inversion Algorithms for Geophysical Problems p. LANZANO Space

  2. Free boundary problems in biology.

    PubMed

    Friedman, Avner

    2015-09-13

    In this paper, I review several free boundary problems that arise in the mathematical modelling of biological processes. The biological topics are quite diverse: cancer, wound healing, biofilms, granulomas and atherosclerosis. For each of these topics, I describe the biological background and the mathematical model, and then proceed to state mathematical results, including existence and uniqueness theorems, stability and asymptotic limits, and the behaviour of the free boundary. I also suggest, for each of the topics, open mathematical problems.

  3. Leisure Time Problems and Livability

    DTIC Science & Technology

    1979-09-30

    satisfaction and for which they received recognition. Housing livability required at least adequate shelter, warmth , safety, minimal conveniences, access to work... judgements are based on preconceived attitudes; others are based on peer group hearsay before arrival and the remainder are formed in the first few weeks after...handicaps including weight, height, physique, skin coloration or complexion, health, beauty, speech problems, domestic problems, limited interpersonal

  4. Families and Pediatric Feeding Problems

    ERIC Educational Resources Information Center

    Martorana, Pamela; Bove, Kelly; Scarcelli, Melissa

    2008-01-01

    When a child is born with a feeding and/or swallowing problem, it affects the entire family. Parents, mothers specifically, internalize the problem and come to believe it is due to something they've done. Families are put on an emotional rollercoaster with the ups and downs being dependant on how much the child has eaten that day. In this article,…

  5. Multigrid method for stability problems

    NASA Technical Reports Server (NTRS)

    Taasan, Shlomo

    1988-01-01

    The problem of calculating the stability of steady state solutions of differential equations is treated. Leading eigenvalues (i.e., having maximal real part) of large matrices that arise from discretization are to be calculated. An efficient multigrid method for solving these problems is presented. The method begins by obtaining an initial approximation for the dominant subspace on a coarse level using a damped Jacobi relaxation. This proceeds until enough accuracy for the dominant subspace has been obtained. The resulting grid functions are then used as an initial approximation for appropriate eigenvalue problems. These problems are being solved first on coarse levels, followed by refinement until a desired accuracy for the eigenvalues has been achieved. The method employs local relaxation on all levels together with a global change on the coarsest level only, which is designed to separate the different eigenfunctions as well as to update their corresponding eigenvalues. Coarsening is done using the FAS formulation in a non-standard way in which the right hand side of the coarse grid equations involves unknown parameters to be solved for on the coarse grid. This in particular leads to a new multigrid method for calculating the eigenvalues of symmetric problems. Numerical experiments with a model problem demonstrate the effectiveness of the method proposed. Using an FMG algorithm a solution to the level of discretization errors is obtained in just a few work units (less than 10), where a work unit is the work involved in one Jacobi relization on the finest level.

  6. The three-body problem

    NASA Astrophysics Data System (ADS)

    Marchal, Christian

    Recent research on the theory of perturbations, the analytical approach and the quantitative analysis of the three-body problem have reached a high degree of perfection. The use of electronics has aided developments in quantitative analysis and has helped to disclose the extreme complexity of the set of solutions. This accelerated progress has given new orientation and impetus to the qualitative analysis that is so complementary to the quantitative analysis. The book begins with the various formulations of the three-body problem, the main classical results and the important questions and conjectures involved in this subject. The main part of the book describes the remarkable progress achieved in qualitative analysis which has shed new light on the three-body problem. It deals with questions such as escapes, captures, periodic orbits, stability, chaotic motions, Arnold diffusion, etc. The most recent tests of escape have yielded very impressive results and border very close on the true limits of escape, showing the domain of bounded motions to be much smaller than was expected. An entirely new picture of the three-body problem is emerging, and the book reports on this recent progress. The structure of the solutions for the three-body problem lead to a general conjecture governing the picture of solutions for all Hamiltonian problems. The periodic, quasi-periodic and almost-periodic solutions form the basis for the set of solutions and separate the chaotic solutions from the open solutions.

  7. Conceptual approach to astronomical problems

    NASA Astrophysics Data System (ADS)

    Skvortsov, N. A.; Avvakumova, E. A.; Bryukhov, D. O.; Vovchenko, A. E.; Vol'nova, A. A.; Dluzhnevskaya, O. B.; Kaigorodov, P. V.; Kalinichenko, L. A.; Kniazev, A. Yu.; Kovaleva, D. A.; Malkov, O. Yu.; Pozanenko, A. S.; Stupnikov, S. A.

    2016-01-01

    New technical capabilities have brought about the sweeping growth of the amount of data acquired by the astronomers from observations with different instruments in various parts of the electromagnetic spectrum. We consider conceptual approach to be a promising tool to efficiently deal with these data. It uses problem domain knowledge to formulate the tasks and develop problem-solving algorithms and data analysis methods in terms of domain concepts without reference to particular data sources, and thereby allows solving certain problems in general form. We demonstrate the benefits of conceptual approach by using it to solve problems related to search for secondary photometric standard candidates, determination of galaxy redshifts, creation of a binary and multiple star repository based on inhomogeneous databases, and classification of eclipsing binaries.We formulate and solve these problems over specifications of astronomical knowledge units such as photometric systems, astronomical objects, multiple stars, etc., and define them in terms of the corresponding problem domains independently of the existing data resources.

  8. Using Problem-Based Learning in Accounting

    ERIC Educational Resources Information Center

    Hansen, James D.

    2006-01-01

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

  9. A Diagnostic Taxonomy of Adult Career Problems.

    ERIC Educational Resources Information Center

    Campbell, Robert E.; Cellini, James V.

    1981-01-01

    Developed a taxonomy for the differential diagnosis of adult career development problems. Problem categories identified were: (1) problems in career decision making; (2) problems in implementing career plans; (3) problems in organizational/institutional performance; and (4) problems in organizational/institutional adaption. (Author)

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  11. National water resources and problems

    USGS Publications Warehouse

    Oltman, Roy E.; MacKichan, Kenneth A.; Mesnier, Glennon N.; Rainwater, Frank H.; Thomasson, Horace G.

    1960-01-01

    Water problems exist in all parts of the United States. Furthermore, the problems are becoming more acute and widespread as population and industry grow. The need is pressing for wider appreciation of the nature of water problems. This requires a background of basic facts about the occurrence of water, its quantity and quality, and the manner in which it is used. This report records some of these basic facts. The facts are that the United States as a whole is well endowed with water. Many water problems (which exist in our country) are caused, however,by poor distribution of water in time and place. Because the nationwide supply of water is large, any given locality could be supplied with water sufficient in quantity and suitable in quality, provided that those who need the water can pay the cost. For the most part, then, water problems are basically social and economic. While management is needed, both locally and regionally, with flexibility to respond to broad geographic patterns of economic and social development.

  12. Behavior problems of pet pigs.

    PubMed

    Tynes, V V

    1997-05-01

    Pigs of all kinds can be enjoyable, charming pets, but the reduced size of the Vietnamese potbellied pig makes it an excellent choice for a porcine pet. Their curious, almost childlike behavior, as well as their adaptability and ease of learning, can make them a real pleasure and a great challenge to keep. The author fears that as many as 25% to 50% of potbellied pigs are no longer in their original homes by 1 year of age primarily because of a high incidence of behavior problems. These are, in reality, "people problems," not "pet problems." The environmental and training requirements of the potbellied pig are more complex and require more understanding than those of the average dog or cat. The author's belief is that the potbellied pig's strong drive to be dominant is a unique behavioral characteristic that more people should be made aware of before acquiring a pet pig. With knowledge of normal pig behavior, problems can be avoided through proper socialization and training. If pet owners consult a veterinarian knowledgeable about pig behavior at the first sign of a problem, treatment usually can be successful.

  13. Approximating random quantum optimization problems

    NASA Astrophysics Data System (ADS)

    Hsu, B.; Laumann, C. R.; Läuchli, A. M.; Moessner, R.; Sondhi, S. L.

    2013-06-01

    We report a cluster of results regarding the difficulty of finding approximate ground states to typical instances of the quantum satisfiability problem k-body quantum satisfiability (k-QSAT) on large random graphs. As an approximation strategy, we optimize the solution space over “classical” product states, which in turn introduces a novel autonomous classical optimization problem, PSAT, over a space of continuous degrees of freedom rather than discrete bits. Our central results are (i) the derivation of a set of bounds and approximations in various limits of the problem, several of which we believe may be amenable to a rigorous treatment; (ii) a demonstration that an approximation based on a greedy algorithm borrowed from the study of frustrated magnetism performs well over a wide range in parameter space, and its performance reflects the structure of the solution space of random k-QSAT. Simulated annealing exhibits metastability in similar “hard” regions of parameter space; and (iii) a generalization of belief propagation algorithms introduced for classical problems to the case of continuous spins. This yields both approximate solutions, as well as insights into the free energy “landscape” of the approximation problem, including a so-called dynamical transition near the satisfiability threshold. Taken together, these results allow us to elucidate the phase diagram of random k-QSAT in a two-dimensional energy-density-clause-density space.

  14. The Challenge of Problem Residents

    PubMed Central

    Yao, David C; Wright, Scott M

    2001-01-01

    Internal medicine residency training is demanding and residents can experience a wide variety of professional and personal difficulties. Residency programs everywhere have had and will continue to have problem residents. Training programs should be equipped to effectively identify and manage residents who experience problems. Previous articles that have been published on the topic of problem residents primarily addressed concerns such as impairment due to depression and substance abuse. The content of this article is derived from a comprehensive review of the literature as well as other data sources such as interviews with program directors and workshops at national professional meetings. This article focuses primarily on four issues related to problem residents: their identification, underlying causes, management, and prevention. The study attempts to be evidence-based, wherever possible, highlighting what is known. Recommendations based on the synthesis of the data are also made. Future ongoing studies of problem residents will improve our understanding of the matters involved, and may ultimately lead to improved outcomes for these trainees. PMID:11520388

  15. Computational problems in Arctic Research

    NASA Astrophysics Data System (ADS)

    Petrov, I.

    2016-02-01

    This article is to inform about main problems in the area of Arctic shelf seismic prospecting and exploitation of the Northern Sea Route: simulation of the interaction of different ice formations (icebergs, hummocks, and drifting ice floes) with fixed ice-resistant platforms; simulation of the interaction of icebreakers and ice- class vessels with ice formations; modeling of the impact of the ice formations on the underground pipelines; neutralization of damage for fixed and mobile offshore industrial structures from ice formations; calculation of the strength of the ground pipelines; transportation of hydrocarbons by pipeline; the problem of migration of large ice formations; modeling of the formation of ice hummocks on ice-resistant stationary platform; calculation the stability of fixed platforms; calculation dynamic processes in the water and air of the Arctic with the processing of data and its use to predict the dynamics of ice conditions; simulation of the formation of large icebergs, hummocks, large ice platforms; calculation of ridging in the dynamics of sea ice; direct and inverse problems of seismic prospecting in the Arctic; direct and inverse problems of electromagnetic prospecting of the Arctic. All these problems could be solved by up-to-date numerical methods, for example, using grid-characteristic method.

  16. Problem Parameters and Problem Finding in Art Education.

    ERIC Educational Resources Information Center

    Sapp, D. David

    1997-01-01

    Presents a model of the relationship between the presented problem parameters of art assignments and the creative processes of students. Parameter types of instructions include incomplete, overly and inadequately restrictive, and expanding/contracting parameters. Parameters of student responses are categorized as disregarded, self-imposed, and…

  17. Solving Optimization Problems with Dynamic Geometry Software: The Airport Problem

    ERIC Educational Resources Information Center

    Contreras, José

    2014-01-01

    This paper describes how the author's students (in-service and pre-service secondary mathematics teachers) enrolled in college geometry courses use the Geometers' Sketchpad (GSP) to gain insight to formulate, confirm, test, and refine conjectures to solve the classical airport problem for triangles. The students are then provided with strategic…

  18. Solving Optimization Problems with Dynamic Geometry Software: The Airport Problem

    ERIC Educational Resources Information Center

    Contreras, José

    2014-01-01

    This paper describes how the author's students (in-service and pre-service secondary mathematics teachers) enrolled in college geometry courses use the Geometers' Sketchpad (GSP) to gain insight to formulate, confirm, test, and refine conjectures to solve the classical airport problem for triangles. The students are then provided with strategic…

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

    ERIC Educational Resources Information Center

    Jones, Ian; Inglis, Matthew

    2015-01-01

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

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

    ERIC Educational Resources Information Center

    Jones, Ian; Inglis, Matthew

    2015-01-01

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