1,075 research outputs found
Enhancing Listening Comprehension Skills Through Exposure to Authentic Conversation
In this field project, the author created a listening comprehension workbook for adult ESL students. The emphasis of the project was to improve the listening comprehension abilities of students through exposing them to authentic American English. The recordings were provided by StoryCorps.gov
Indicators of teacher collaboration in Texas public high schools
The study employs both quantitative and qualitative data to extend the work of Rosenholtz (1991) with public elementary schools and the work of Hickey (1994) with public secondary schools in trying to assess the extent to which four pre-defined socio-organizational factors predict teacher collaboration in public schools. The four socio-organizational factors include: teacher certainty about a technical culture and their instructional capability; shared instructional goals; teacher involvement in decision making about instructional matters; and teacher involvement in team teaching. The study also investigates the hypothesis that the academic departments in public secondary schools provide structures that more nearly approach the structure of entire elementary schools than do entire secondary schools and, thus, comprise units more likely to yield results similar to those found among elementary schools.
In order to explore these areas, the study addresses the following questions: (1) What is the relationship between teacher collaboration in the study\u27s schools and the pre-defined socio-organizational conditions? (2) What is the relationship between teacher collaboration in the core academic departments within the study\u27s high schools and the pre-defined socio-organizational conditions? (3) Compared to each other, to what extent are the study\u27s high schools collaborative? (4) To what extent is a specified core academic department within a high school collaborative compared to the other core academic departments within the school?
After an initial process used to identify schools that knowledgeable personnel in the region deemed likely collaborative or isolated, the researcher administered a Teacher Opinion Questionnaire to determine the relative extent of collaboration in the study\u27s schools and among the four core academic departments within each of the study\u27s schools. To enrich the data, members from one core academic department at the most nearly collaborative and one at the most nearly isolated school responded to interview questions.
Neither the selected secondary schools nor their core academic departments demonstrated significant variation in the extent of relative collaboration and isolation. However, the four socio-organizational factors did co-vary with teacher collaboration to a significant extent, explaining more than one quarter of the teacher collaboration in the study\u27s schools.
Although the study\u27s quantitative data fail to provide any evidence that high school core academic departments provide units of analysis more likely to yield results similar to those from elementary schools, the qualitative data strongly indicate that high school teachers depend to a much greater extent for instructional support on their departments than on their schools as whole units
Resolving depth measurement ambiguity with commercially available range imaging cameras
Time-of-flight range imaging is typically performed with the amplitude modulated continuous wave method. This involves illuminating a scene with amplitude modulated light. Reflected light from the scene is received by the sensor with the range to the scene encoded as a phase delay of the modulation envelope. Due to the cyclic nature of phase, an ambiguity in the measured range occurs every half wavelength in distance, thereby limiting the maximum useable range of the camera.
This paper proposes a procedure to resolve depth ambiguity using software post processing. First, the range data is processed to segment the scene into separate objects. The average intensity of each object can then be used to determine which pixels are beyond the non-ambiguous range. The results demonstrate that depth ambiguity can be resolved for various scenes using only the available depth and intensity information. This proposed method reduces the sensitivity to objects with very high and very low reflectance, normally a key problem with basic threshold approaches.
This approach is very flexible as it can be used with any range imaging camera. Furthermore, capture time is not extended, keeping the artifacts caused by moving objects at a minimum. This makes it suitable for applications such as robot vision where the camera may be moving during captures.
The key limitation of the method is its inability to distinguish between two overlapping objects that are separated by a distance of exactly one non-ambiguous range. Overall the reliability of this method is higher than the basic threshold approach, but not as high as the multiple frequency method of resolving ambiguity
The localization sequence for the algebraic K-theory of topological K-theory
We prove a conjecture of Rognes by establishing a localization cofiber
sequence of spectra, K(Z) to K(ku) to K(KU) to Sigma K(Z), for the algebraic
K-theory of topological K-theory. We deduce the existence of this sequence as a
consequence of a devissage theorem identifying the K-theory of the Waldhausen
category of Postnikov towers of modules over a connective A-infinity ring
spectrum R with the Quillen K-theory of the abelian category of finitely
generated pi_0(R)-modules.Comment: Updated final version. Small change in definition of S' construction
and correction to the proof of 2.
Advantages of 3D time-of-flight range imaging cameras in machine vision applications
Machine vision using image processing of traditional intensity images is in wide spread use. In many situations environmental conditions or object colours or shades cannot be controlled, leading to difficulties in correctly processing the images and requiring complicated processing algorithms. Many of these complications can be avoided by using range image data, instead of intensity data. This is because range image data represents the physical properties of object location and shape, practically independently of object colour or shading. The advantages of range image processing are presented, along with three example applications that show how robust machine vision results can be obtained with relatively simple range image processing in real-time applications
The smash product for derived categories in stable homotopy theory
An E_1 (or A-infinity) ring spectrum R has a derived category of modules D_R.
An E_2 structure on R endows D_R with a monoidal product. An E_3 structure on R
endows the monoidal product with a braiding. If the E_3 structure extends to an
E_4 structure then the braided monoidal product is symmetric monoidal.Comment: Minor correction
Traspasando las siete vidas. Traducido por Marta Alonso Pérez, Iris Barrio Rodríguez y Francisco Esteban Gracia.
Within- and across-breed imputation of high-density genotypes in dairy and beef cattle from medium- and low-density genotypes
peer-reviewedFinancial support of the Irish Department of Agriculture Research Stimulus Fund (RSF-06-0353; RSF-06-0428; 11/SF/311), Science Foundation Ireland (09/IN.1/B2642) and the Irish dairy and beef industry are gratefully acknowledged.The objective of this study was to evaluate, using three different genotype
density panels, the accuracy of imputation from lower- to higher-density
genotypes in dairy and beef cattle. High-density genotypes consisting of
777 962 single-nucleotide polymorphisms (SNP) were available on 3122
animals comprised of 269, 196, 710, 234, 719, 730 and 264 Angus, Belgian
Blue, Charolais, Hereford, Holstein-Friesian, Limousin and Simmental
bulls, respectively. Three different genotype densities were generated:
low density (LD; 6501 autosomal SNPs), medium density (50K; 47 770
autosomal SNPs) and high density (HD; 735 151 autosomal SNPs). Imputation
from lower- to higher-density genotype platforms was undertaken
within and across breeds exploiting population-wide linkage disequilibrium.
The mean allele concordance rate per breed from LD to HD when
undertaken using a single breed or multiple breed reference population
varied from 0.956 to 0.974 and from 0.947 to 0.967, respectively. The
mean allele concordance rate per breed from 50K to HD when undertaken
using a single breed or multiple breed reference population varied from
0.987 to 0.994 and from 0.987 to 0.993, respectively. The accuracy of
imputation was generally greater when the reference population was
solely comprised of the breed to be imputed compared to when the reference
population comprised of multiple breeds, although the impactDepartment of Agriculture, Food and the MarineScience Foundation Irelan
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