6,749 research outputs found
Examination of Preschool Educators\u27 Implementation of Motor Activities
This project was designed to obtain and analyze data pertaining to a teacher’s understanding of movement education in a preschool program. The purpose of this research was to conduct a case study to examine a preschool educator’s knowledge and use of motor activities in the classroom. The preschool teacher was observed and interviewed. The teacher was given a survey that included questions about aspects of motor development in preschool classrooms in early childhood centers, and whether professional development training in motor learning had been offered for early childhood educators
Ward's Hierarchical Clustering Method: Clustering Criterion and Agglomerative Algorithm
The Ward error sum of squares hierarchical clustering method has been very
widely used since its first description by Ward in a 1963 publication. It has
also been generalized in various ways. However there are different
interpretations in the literature and there are different implementations of
the Ward agglomerative algorithm in commonly used software systems, including
differing expressions of the agglomerative criterion. Our survey work and case
studies will be useful for all those involved in developing software for data
analysis using Ward's hierarchical clustering method.Comment: 20 pages, 21 citations, 4 figure
Inertial coalescence of droplets on a partially wetting substrate
We consider the growth rate of the height of the connecting bridge in rapid surface-tension-driven coalescence of two identical droplets attached on a partially wetting substrate. For a wide range of contact angle values, the height of the bridge grows with time following a power law with a universal exponent of 2/3, up to a threshold time, beyond which a 1/2 exponent results, that is known for coalescence of freely-suspended droplets. In a narrow range of contact angle values close to 90°, this threshold time rapidly vanishes and a 1/2 exponent results for a 90° contact angle. The argument is confirmed by three-dimensional numerical simulations based on a diffuse interface method with adaptive mesh refinement and a volume-of-fluid method
The Third International Symposium on Tilapia in Aquaculture
Tilapias, because of the low cost and relative ease of their production, are a potential food fish staple for many people ini tropical countries and a globally traded commodity. This volume of symposium proceedings shows a strong interest in production systems research and a dawning interest in socioeconomic research. Both of these fields of research are expected to receive much greater attention in the future as the economic and market importance of tilapia increases and as we seek to understand better the distribution of benefits of the different production technologies.Tilapia culture Tilapia, Oreochromis, Sarotherodon
Transitional random matrix theory nearest-neighbor spacing distributions
This paper presents a study of the properties of a matrix model that was
introduced to describe transitions between all Wigner surmises of Random Matrix
theory. New results include closed-form exact analytical expressions for the
transitional probability density functions, as well as suitable analytical
approximations for cases not amenable to explicit representation
Evaluation of force-torque displays for use with space station telerobotic activities
Recent experiments which addressed Space Station remote manipulation tasks found that tactile force feedback (reflecting forces and torques encountered at the end-effector through the manipulator hand controller) does not improve performance significantly. Subjective response from astronaut and non-astronaut test subjects indicated that force information, provided visually, could be useful. No research exists which specifically investigates methods of presenting force-torque information visually. This experiment was designed to evaluate seven different visual force-torque displays which were found in an informal telephone survey. The displays were prototyped in the HyperCard programming environment. In a within-subjects experiment, 14 subjects nullified forces and torques presented statically, using response buttons located at the bottom of the screen. Dependent measures included questionnaire data, errors, and response time. Subjective data generally demonstrate that subjects rated variations of pseudo-perspective displays consistently better than bar graph and digital displays. Subjects commented that the bar graph and digital displays could be used, but were not compatible with using hand controllers. Quantitative data show similar trends to the subjective data, except that the bar graph and digital displays both provided good performance, perhaps do to the mapping of response buttons to display elements. Results indicate that for this set of displays, the pseudo-perspective displays generally represent a more intuitive format for presenting force-torque information
- …