Open mathematical modelling problems that can be solved with multiple methods and have multiple possible results are an important part of school curricula in mathematics and science. Solving open ...modelling problems in school should prepare students to apply their mathematical knowledge in their current and future lives. One characteristic of these problems is that information that is essential for solving the problems is missing. In the present study, we aimed to analyze students’ cognitive barriers while they solved open modelling problems, and we evaluated the effects of instructional prompts on their success in solving such problems. A quantitative experimental study (
N
= 263) and a qualitative study (
N
= 4) with secondary school students indicated that identifying unknown quantities and making numerical assumptions about these quantities are important cognitive barriers to solving open modelling problems. Task-specific instructional prompts helped students overcome these barriers and improved their solution rates. Students who were given instructional prompts included numerical assumptions in their solutions more often than students who were not given such prompts. These findings contribute to theories about solving open modelling problems by uncovering cognitive barriers and describing students’ cognitive processes as they solve these problems. In addition, the findings contribute to improving teaching practice by indicating the potential and limitations of task-specific instructional prompts that can be used to support students’ solution processes in the classroom.
While maternal at-risk drinking is associated with children's emotional and behavioral problems, there is a paucity of research that properly accounts for genetic confounding and gene-environment ...interplay. Therefore, it remains uncertain what mechanisms underlie these associations. We assess the moderation of associations between maternal at-risk drinking and childhood emotional and behavioral problems by common genetic variants linked to environmental sensitivity (genotype-by-environment G × E interaction) while accounting for shared genetic risk between mothers and offspring (GE correlation).
We use data from 109 727 children born to 90 873 mothers enrolled in the Norwegian Mother, Father, and Child Cohort Study. Women self-reported alcohol consumption and reported emotional and behavioral problems when children were 1.5/3/5 years old. We included child polygenic scores (PGSs) for traits linked to environmental sensitivity as moderators.
Associations between maternal drinking and child emotional (
= 0.04 95% confidence interval (CI) 0.03-0.05) and behavioral (
= 0.07 0.06-0.08) outcomes attenuated after controlling for measured confounders and were almost zero when we accounted for unmeasured confounding (emotional:
= 0.01 0.00-0.02; behavioral:
= 0.01 0.00-0.02). We observed no moderation of these adjusted exposure effects by any of the PGS.
The lack of strong evidence for G × E interaction may indicate that the mechanism is not implicated in this kind of intergenerational association. It may also reflect insufficient power or the relatively benign nature of the exposure in this sample.
We analyze a class of initial-boundary value problems for the Degasperis–Procesi equation on the half-line. Assuming that the solution u(x,t) exists, we show that it can be recovered from its initial ...and boundary values via the solution of a Riemann–Hilbert problem formulated in the plane of the complex spectral parameter k.
Solving mathematical ( math ) word problems (MWP) automatically is a challenging research problem in natural language processing , machine learning , and education (learning) technology domains, ...which has gained momentum in the recent years. Applications of solving varieties of MWPs can increase the efficacy of teaching-learning systems, such as e-learning systems , intelligent tutoring systems , etc., to help improve learning (or teaching) to solve word problems by providing interactive computer support for peer math tutoring. This article is specifically intended to benefit such teaching-learning systems on arithmetic word problems solving by adding an interactive and intelligent word problem solver to assess an individual's learning outcome. This article presents arithmetic mathematical word problems solver (AMWPS), an educational software application for solving arithmetic word problems involving single equation with single operation . This article is based on a combination of a machine learning based (classification) approach and a rule-based approach. We start with classification of arithmetic word problems into four categories ( Change , Compare , Combine , and Division-Multiplication ) along with their subcategories, followed by the classification of operations (+, -, *, and /) related to different subcategories. Our system processes an input arithmetic word problem, predicts the category and subcategory, predicts the operation, identifies and retrieves the relevant quantities within the problem with respect to answer generation, and formulates and evaluates the mathematical expression to generate the final answer. AMWPS outperformed similar systems on the standard AddSub and SingleOp datasets and produced new state-of-the-art result (94.22% accuracy).
Wicked Problems Head, Brian W.; Alford, John
Administration & society,
08/2015, Letnik:
47, Številka:
6
Journal Article
Recenzirano
The concept of “wicked problems” has attracted increasing focus in policy research, but the implications for public organizations have received less attention. This article examines the main ...organizational and cognitive dimensions emerging from the research literature on wicked problems. We identify several recent approaches to addressing problem complexity and stakeholder divergence based on the literatures on systems thinking, collaboration and coordination, and the adaptive leadership roles of public leaders and managers. We raise some challenges for public management in some key functional areas of government—strategy making, organizational design, people management, and performance measurement. We argue that provisional solutions can be developed, despite the difficulties of reforming governance processes to address wicked problems more effectively.
Numerous adolescents in the United States experience peer cybervictimization, which is associated with a series of internalizing (e.g., depression, anxiety, anger) and externalizing (e.g., ...aggression, substance use, risky sexual behavior) problems. The current study provides a systematic review and meta-analysis of existing research on these relationships. Included in the meta-analyses are 239 effect sizes from 55 reports, representing responses from 257,678 adolescents. The results of a series of random effects meta-analyses using robust variance estimation indicated positive and significant relationships between peer cybervictimization and a series of internalizing and externalizing problems, with point estimates of this relationship ranging from Pearson’s
r
= .14 to .34. Implications for research and practice are discussed.
We prove a general perturbation theorem that can be used to obtain pairs of nontrivial solutions of a wide range of local and nonlocal nonhomogeneous elliptic problems. Applications to critical ...p-Laplacian problems, p-Laplacian problems with critical Hardy-Sobolev exponents, critical fractional p-Laplacian problems, and critical (p,q)-Laplacian problems are given. Our results are new even in the semilinear case p=2.
Shrinking Cities: Urban Challenges of Globalization MARTINEZ-FERNANDEZ, CRISTINA; AUDIRAC, IVONNE; FOL, SYLVIE ...
International journal of urban and regional research,
March 2012, Letnik:
36, Številka:
2
Journal Article
Recenzirano
Urban shrinkage is not a new phenomenon. It has been documented in a large literature analyzing the social and economic issues that have led to population flight, resulting, in the worse cases, in ...the eventual abandonment of blocks of housing and neighbourhoods. Analysis of urban shrinkage should take into account the new realization that this phenomenon is now global and multidimensional — but also little understood in all its manifestations. Thus, as the world's population increasingly becomes urban, orthodox views of urban decline need redefinition. The symposium includes articles from 10 urban analysts working on 30 cities around the globe. These analysts belong to the Shrinking Cities International Research Network (SCIRN), whose collaborative work aims to understand different types of city shrinkage and the role that different approaches, policies and strategies have played in the regeneration of these cities. In this way the symposium will inform both a rich diversity of analytical perspectives and country‐based studies of the challenges faced by shrinking cities. It will also disseminate SCIRN's research results from the last 3 years.
Résumé
La décroissance urbaine n'est pas un phénomène nouveau. De nombreux travaux ont analysé les problèmes sociaux et économiques conduisant au départ de populations et résultant dans les pires des cas à l'abandon d'îlots d'habitat et de quartiers entiers. Cependant, l'étude de la décroissance urbaine doit aujourd'hui tenir compte du constat récent selon lequel ce phénomène est désormais global et multidimensionnel, tout en restant peu appréhendé dans toutes ses composantes. Ainsi, alors que la population mondiale est de plus en plus urbaine, les conceptions classiques du déclin urbain méritent d'être réexaminées. Ce symposium inclut des articles de dix chercheurs travaillant sur trente villes à travers le monde. Ils appartiennent au Shrinking Cities International Research Netwok (SCIRN), dont le travail collectif a pour objectif d'analyser différents types de décroissance urbaine et le rôle que les multiples approches, politiques et stratégies ont joué dans la régénération des villes touchées par ce processus. Ce numéro s'appuie sur une diversité d'approches et sur l'étude de contextes urbains variés, ayant pour point commun d'être concernés par les enjeux de la décroissance urbaine. Il permet de diffuser les résultats des recherches menées au sein du SCIRN au cours des trois dernières années.
In this paper, the initial-boundary-value problems for the generalized multi-term time-fractional diffusion equation over an open bounded domain
G
×
(
0
,
T
)
,
G
∈
R
n
are considered. Based on an ...appropriate maximum principle that is formulated and proved in the paper, too, some a priory estimates for the solution and then its uniqueness are established. To show the existence of the solution, first a formal solution is constructed using the Fourier method of the separation of the variables. The time-dependent components of the solution are given in terms of the multinomial Mittag-Leffler function. Under certain conditions, the formal solution is shown to be a generalized solution of the initial-boundary-value problem for the generalized time-fractional multi-term diffusion equation that turns out to be a classical solution under some additional conditions. Another important consequence from the maximum principle is a continuously dependence of the solution on the problem data (initial and boundary conditions and a source function) that – together with the uniqueness and existence results – makes the problem under consideration to a well-posed problem in the Hadamard sense.
Previous research suggests that victims of partner physical violence (PPV) often face multiple distinct problems, but comparative population-based studies focusing on the prevalence of multiple ...problems are lacking. Aim of the present study is to gain insight in the prevalence of multiple problems among individuals victimized by PPV in the past 12 months, compared with matched nonvictims and victims of non-partner physical violence (non-PPV). For this purpose, data were extracted from two population-based surveys conducted in 2018 and 2019 on potentially traumatic events in the Netherlands. We focused on problems identified in previous studies on PPV and non-PPV and related problems, varying from physical health, mental health, financial and legal problems, to lack of social support and being exposed to other potentially traumatic and stressful life events (LFEs). In total, 49 respondents were victimized by PPV and 89 by non-PPV in the past 12 months. They were compared with pairwise matched groups not affected by any traumatic or stressful LFEs in this period (nPPV victims comparison group = 245, nnon-PPV comparison group = 445). Results showed that PPV victims significantly more often faced all 12 distinct problems than matched nonvictims (2.31 ≤ odds ratio OR ≤ 15.48) and non-PPV victims (2.12 ≤ OR ≤ 4.52). PPV victims more often had any problem than non-PPV victims (OR = 8.19), but no significant differences were found between PPV and non-PPV victims with regard to mental health problems. Findings stress the necessity of a multidisciplinary coordinated community response to help PPV victims.
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