Selecting, Sequencing, and Connecting: Using Technology to Support Area Measurement through Tasks, Strategies, and Discussion

This paper supports grades 3-5 mathematics teachers and considers how technology in the classroom can be used to support low threshold, high ceiling tasks and productive discussion. We present a description of a card-sorting task to support the “5 Practices of Productive Mathematics Discussions” focused on an online task designed to: be open to multiple levels of strategies, reveal misconceptions, and support students in developing more sophisticated conceptual understandings of area measurement. We present a sampling of strategies created by teachers (who were pretending to be elementary students) in past activities. We discuss approaches to connecting strategies for deeper understanding of area measurement

Selecting, Sequencing, and Connecting: Using Technology to Support Area Measurement Through Tasks, Strategies, and Discussion

This paper supports grades 3-5 mathematics teachers and considers how technology in the classroom can be used to support low threshold, high ceiling tasks and productive discussion. We present a description of a card-sorting task to support the “5 Practices of Productive Mathematics Discussions” focused on an online task designed to: be open to multiple levels of strategies, reveal misconceptions, and support students in developing more sophisticated conceptual understandings of area measurement. We present a sampling of strategies created by teachers (who were pretending to be elementary students) in past activities. We discuss approaches to connecting strategies for deeper understanding of area measurement

Elementary School Students' Strategies for Solving Area Measurement Problems

This study aims to identify the strategies used by elementary school students in solving area measurement problems. The research method used was a descriptive qualitative approach. The data collection techniques used in this research are task, interview, observation, and documentation. The data presentation techniques used were data reduction, data presentation, and conclusion drawing/verification. The research subjects used were elementary school students in grades 3, 4, 5, and 6. In this study, it was found that there were six strategies used by students in solving area measurement problems, namely 1) counting the number of square units, 2) decomposing the shape, 3) applying length reasoning, 4) counting all units, 5) multiplying length and width, 6) dividing the whole by the number of divisions. Counting all units is the most widely used strategy by elementary school students. Solving area measurement problems is influenced by students' experience obtaining area measurement material. The results of this study suggest that students prioritize strategies in problem solving. If the strategy students use is correct, then the arrangement structure regarding the solution will be appropriate

Frequency Control of Multi-Pulse 2-micron Laser Transmitter for Atmospheric Carbon Dioxide Measurement

Laser sources with highly stabilized emission wavelength is of paramount importance for a long term atmospheric carbon dioxide (CO2) measurement from a space platform. Integrated Path Differential Absorption (IPDA) lidar is a promising instrument for such a task. The design of a laser transmitter, with emphasis on the method used to control and select several wavelengths, is presented. This multi-pulsed, injection seeded, 2-m transmitter uses a Ho:Tm:YLF laser crystal which has matching emission to the absorption of CO2 in the R30 spectroscopic area. The injection seeded laser produces triple single longitudinal mode transform limited line width pulses with a total of 80 mJ at a repetition rate of 50 Hz

Optimisation of surface measurement for metal additive manufacturing using coherence scanning interferometry

Surface topography measurement for metal additive manufacturing (AM) is a challenging task for contact and non-contact methods. In this paper, we present an experimental investigation of the use of coherence scanning interferometry (CSI) for measurement of AM surfaces. Our approach takes advantage of recent technical enhancements in CSI, including high dynamic range for light level and adjustable data acquisition rates for noise reduction. The investigation covers several typical metal AM surfaces made from different materials and AM processes. Recommendations for measurement optimisation balance three aspects: data coverage, measurement area and measurement time. This study also presents insight into areas of interest for future rigorous examination, such as measurement noise and further development of guidelines for the measurement of metal AM surfaces

An Investigation of the Visual Selective Attention Abilities of Children Completing a Kindergarten Program

This study investigated the ability of children completing a kindergarten program to perform a visual selective attention task. It also examined the data to determine if measurement of the task in the visual area would complement significantly a traditional reading readiness assessment. Subjects were instructed to sort 25 stimulus cards according to the central feature, the Greek letter. They were told to ignore the incidental features of card shape, card background color and color of the Greek letter. The subjects were given a central score for the cards correctly grouped. After completing the task, the subjects were asked to recall the card shapes and card background colors to see if any incidental learning had taken place. Correct answers yielded an incidental score. The results demonstrate that central and incidental learning have an inverse relationship to each other. The results also indicate that children completing a kindergarten program can successfully perform a visual selective attention task with a high degree of accuracy. Longitudinal evidence is necessary before it can be determined if measurement of this task would complement significantly a traditional reading readiness assessment. The use of a visual selective attention task may be a useful additional screening procedure, especially where traditional measures are inconclusive

Object Tracking from Unstabilized Platforms by Particle Filtering with Embedded Camera Ego Motion

Visual tracking with moving cameras is a challenging task. The global motion induced by the moving camera moves the target object outside the expected search area, according to the object dynamics. The typical approach is to use a registration algorithm to compensate the camera motion. However, in situations involving several moving objects, and backgrounds highly affected by the aperture problem, image registration quality may be very low, decreasing dramatically the performance of the tracking. In this work, a novel approach is proposed to successfully tackle the tracking with moving cameras in complex situations, which involve several independent moving objects. The key idea is to compute several hypotheses for the camera motion, instead of estimating deterministically only one. These hypotheses are combined with the object dynamics in a Particle Filter framework to predict the most probable object locations. Then, each hypothetical object location is evaluated by the measurement model using a spatiogram, which is a region descriptor based on color and spatial distributions. Experimental results show that the proposed strategy allows to accurately track an object in complex situations affected by strong ego motion

The Addition Of A Concurrent Bimanual Task Influences Postural Sway And Walking Speed Performance And Prioritization Across All Ages

As individuals age, there is an increase in attentional demands, a heavier reliance on vision, reduction in efficiency of both tasks, and longer processing intervals causing greater dual task interference on postural sway and walking speed. While cognitive-motor interference has been investigated, the impact of adding a functional, manual task while balancing or during gait is poorly understood across all ages. The overall purpose was to examine the relationship between age and task automaticity in dual-task conditions with a functional bimanual task, and describe how age influences attentional prioritization strategies. Older adults demonstrated differences in single and dual task performance for measurements of postural sway (center of pressure path length and 95% ellipse area) and walking speed (self-selected and fast paced walking) from adults younger than 60 years old. The dual task cost for one measurement of postural sway, the 95% ellipse area, was predicted by age, cognition, experiences with dual tasks, and the dual task cost of the bimanual task. Both self-selected and fast paced walking speeds dual task costs were predicted by functional reach and the perceived difficulty of dual tasks. Furthermore, mutual interference was experienced for all individuals during the postural sway task and fast paced walking task. Younger individuals chose to focus their attention on the selfselected walking speed while older adults experienced mutual interference more often. Therefore, single and dual task performance is related to age, however, other factors including cognition, mobility, and perceived abilities are better indicators of the dual task cost experienced by individuals during balance and walking dual task