51,795 research outputs found
Using improved analytical programming algorithm for effort estimation in software engineering
This paper evaluates the usage of improved analytical programming algorithm for software effort estimation. The new model was generated by improved analytical programming and it was tested and compared with Karner's model to assess its properties. Least Absolute Deviation and random sub-sampling cross validation were used to assess the reliability to this experiment. The experimental results shows that the new model generated by analytical programming outperforms the Karner's equation about 40 %. Moreover, this work shows that improved analytical programming algorithm is feasible method for calibrating Use Case Points method. All results were evaluated by standard approach: visual inspection and statistical significance testing.Internal Grant Agency of Tomas Bata University in Zlin [IGA/FAI/2016/035
A comparative study of calibration methods for low-cost ozone sensors in IoT platforms
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper shows the result of the calibration process of an Internet of Things platform for the measurement of tropospheric ozone (O 3 ). This platform, formed by 60 nodes, deployed in Italy, Spain, and Austria, consisted of 140 metal–oxide O 3 sensors, 25 electro-chemical O 3 sensors, 25 electro-chemical NO 2 sensors, and 60 temperature and relative humidity sensors. As ozone is a seasonal pollutant, which appears in summer in Europe, the biggest challenge is to calibrate the sensors in a short period of time. In this paper, we compare four calibration methods in the presence of a large dataset for model training and we also study the impact of a limited training dataset on the long-range predictions. We show that the difficulty in calibrating these sensor technologies in a real deployment is mainly due to the bias produced by the different environmental conditions found in the prediction with respect to those found in the data training phase.Peer ReviewedPostprint (author's final draft
High Temperature Strain Gage Calibration Fixture
An apparatus and method are described for calibrating high temperature strain gases which serve for both dead weight and constant deflection measurements. A cantilever support arm allows the test unit to slide into a furnace while one end is subjected to bending strain either by hanging weights upon it or by deflecting it with a push rod. The dual nature of the fixture permits both tests to be run without change of the test specimen or removal from the furnace
The age of the oldest Open Clusters
We determine ages of 71 old Open Clusters by a two-step method: we use
main-squence fitting to 10 selected clusters, in order to obtain their
distances, and derive their ages from comparison with our own isochrones used
before for Globular Clusters. We then calibrate the morphological age indicator
delta(V), which can be obtained for all remaining clusters, in terms of age and
metallicity. Particular care is taken to ensure consistency in the whole
procedure. The resulting Open Cluster ages connect well to our previous
Globular Cluster results. From the Open Cluster sample, as well as from the
combined sample, questions regarding the formation process of Galactic
components are addressed. The age of the oldest open clusters (NGC6791 and
Be17) is of the order of 10 Gyr. We determine a delay by 2.0+-1.5 Gyr between
the start of the halo and thin disk formation, whereas thin and thick disk
started to form approximately at the same time. We do not find any significant
age-metallicity relationship for the open cluster sample. The cumulative age
distribution of the whole open cluster sample shows a moderately significant
(~2sigma level) departure from the predictions for an exponentially declining
dissolution rate with timescale of 2.5 Gyr. The cumulative age distribution
does not show any trend with galactocentric distance, but the clusters with
larger height to the Galactic plane have an excess of objects between 2-4 and 6
Gyr with respect to their counterpart closer to the plane of the Galaxy.Comment: Astronomy & Astrophysics, in pres
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