Influences on classification accuracy of exam sets: an example from vocational education and training

Classification accuracy of single exams is well studied in the educational measurement literature. However, when making important decisions, such as certification decisions, one usually uses several exams: an exam set. This chapter elaborates on classification accuracy of exam sets. This is influenced by the shape of the ability distribution, the height of the standards, and the possibility for compensation. This is studied using an example from vocational education and training (VET). The classification accuracy for an exam set is computed using item response theory (IRT) simulation. Classification accuracy is high when all exams from an exam set have equal and standardized ability distributions. Furthermore, exams where few or no students pass or fail increase classification accuracy. Finally, allowing compensation increases classification accurac

Smithsonian Contributions to Astrophysics

Classification of meteoroids according to density and beginning height, and meteor stream searc

Geometrical Phase Transition on WO3_3 Surface

A topographical study on an ensemble of height profiles obtained from atomic force microscopy techniques on various independently grown samples of tungsten oxide WO$_3$ is presented by using ideas from percolation theory. We find that a continuous 'geometrical' phase transition occurs at a certain critical level-height $\delta_c$ below which an infinite island appears. By using the finite-size scaling analysis of three independent percolation observables i.e., percolation probability, percolation strength and the mean island-size, we compute some critical exponents which characterize the transition. Our results are compatible with those of long-range correlated percolation. This method can be generalized to a topographical classification of rough surface models.Comment: 3 pages, 4 figures, to appear in Applied Physics Letters (2010

Dieudonne crystals and Wach modules for p-divisible fgroups

Let $k$ be a perfect field of characteristic $p>2$ and $K$ an extension of $F=\mathrm{Frac} W(k)$ contained in some $F(\mu_{p^r})$. Using crystalline Dieudonn\'e theory, we provide a classification of $p$-divisible groups over $\mathscr{O}_K$ in terms of finite height $(\varphi,\Gamma)$-modules over $\mathfrak{S}:=W(k)[[u]]$. Although such a classification is a consequence of (a special case of) the theory of Kisin--Ren, our construction gives an independent proof and allows us to recover the Dieudonn\'e crystal of a $p$-divisible group from the Wach module associated to its Tate module by Berger--Breuil or by Kisin--Ren

New anthropometric classification scheme of preoperative nutritional status in children: A retrospective observational cohort study

Objective: WHO uses anthropometric classification scheme of childhood acute and chronic malnutrition based on low body mass index (BMI) (\u27wasting\u27) and height for age (\u27stunting\u27), respectively. The goal of this study was to describe a novel two-axis nutritional classification scheme to (1) characterise nutritional profiles in children undergoing abdominal surgery and (2) characterise relationships between preoperative nutritional status and postoperative morbidity. Design: This was a retrospective observational cohort study. Setting: The setting was 50 hospitals caring for children in North America that participated in the American College of Surgeons National Surgical Quality Improvement Program Paediatric from 2011 to 2013. Participants: Children \u3e28 days who underwent major abdominal operations were identified. Interventions/main predictor: The cohort of children was divided into five nutritional profile groups based on both BMI and height for age Z-scores: (1) underweight/short, (2) underweight/tall, (3) overweight/short, (4) overweight/tall and (5) non-outliers (controls). Main outcome measures: Multiple variable logistic regressions were used to quantify the association between 30-day morbidity and nutritional profile groups while adjusting for procedure case mix, age and American Society of Anaesthesiologists class. Results: A total of 39 520 cases distributed as follows: underweight/short (656, 2.2%); underweight/tall (252, 0.8%); overweight/short (733, 2.4%) and overweight/tall (1534, 5.1%). Regression analyses revealed increased adjusted odds of composite morbidity (35%) and reintervention events (75%) in the underweight/short group, while overweight/short patients had increased adjusted odds of composite morbidity and healthcare-associated infections (43%), and reintervention events (79%) compared with controls. Conclusion: Stratification of preoperative nutritional status using a scheme incorporating both BMI and height for age is feasible. Further research is needed to validate this nutritional risk classification scheme for other surgical procedures in children

Impact of Prenatal Checkups of Mothers and Immunization of Children on the Health Status of Children (0-3 years) - A Study in Rural areas of Aligarh District, Uttar Pradesh.

Background and objectives: A survey based study on rural areas of Aligarh District was conducted to assess the prenatal checkups pregnant women and its effects on health status of children between the age of (0-3 years), and immunization received by children and its effects on their health status. Methods: Five hundred children from five villages of rural areas of Aligarh District were randomly selected. For the purpose of the study, a self prepared structured interview schedule was used. To get the qualitative information of the study anthropometric measures include height weight were used for assessing growth pattern of the child. The stepwise analysis of two variables height for age and weight for age was done on the basis of Water low’s and Gomez’ classification. To examine the relationship between Health Status of the child and selected variable that affects Health Status of children, Chi-square test was employed. Results: Based on Gomez’ classification out of 88% mothers who did not go for prenatal ups majority 80% of children were underweight, and 80% of children who did not receive immunization majority 60% were underweight. Based on Waterlow’s classification majority 68% of children were stunted whose mother did not go for prenatal checkups and 50% of their children were stunted who did not receive immunization. Conclusion: Majority of children were stunted whose mother did not go for prenatal checkup and the children who did not receive immunization

Fields with the Bogomolov property

A field is said to have the Bogomolov property relative to a height function h’ if and only if h’ is either zero or bounded from below by a positive constant for all for all elements in this field. In this thesis we study this property according to canonical heights associated to rational functions introduced by Call and Silverman in 1994. In the first part we will translate known results into the dynamical setting. Then we prove an effective version of a theorem of Baker which states that the Néron-Tate height of an elliptic curve with multiplicative reduction at a finite place v is bounded from below by a positive constant at points which are unramified over v. In the last section of this thesis we give a complete classification of rational functions f defined over the algebraic numbers such that the maximal totally real field has the Bogomolov property relative to the canonical height associated to f