Speed and accuracy evaluation of additive manufacturing machines

2011 ◽  
Vol 17 (1) ◽  
pp. 64-75 ◽  
Author(s):  
Tomaz Brajlih ◽  
Bogdan Valentan ◽  
Joze Balic ◽  
Igor Drstvensek
2015 ◽  
Vol 761 ◽  
pp. 98-103
Author(s):  
Toshitake Tateno ◽  
Yuta Yaguchi ◽  
Osamu Hasegawa

Most rapid prototyping models are fabricated by additive manufacturing (AM) devices, which are usually called as 3D-printers. The AM models are expected to be used as practical parts for small batch manufacturing and maintenance parts supply. The main problem of AM for practical parts depends on processing accuracy and productivity. To compete with these problems, the parallel fabrication is considered. In this paper, after the concept of the parallel fabrication is introduced, the geometric accuracy of AM parts is evaluated and discussed from viewpoints of shape and processing. Two primitive shapes, which are a cube and a cylinder, are chosen as evaluation objects. These models are fabricated by two different type AM processing, which are Stereo Lithography (SL) and Fused Deposition Modeling (FDM). The geometry of objects is measured by a contact type 3D measurement system. As a result, characteristics of geometric error, which depend on shape features and AM processing, were found. The design guideline for contact surfaces between segmented parts is discussed.


2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607


2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.


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