scholarly journals A Benchmark of Non-intrusive Parametric Audio Quality Estimation Models for Broadcasting Systems and Web-casting Applications

Author(s):  
Martin Jakubik ◽  
Peter Pocta
Author(s):  
DANIELLE AZAR

In this work, we present a genetic algorithm to optimize predictive models used to estimate software quality characteristics. Software quality assessment is crucial in the software development field since it helps reduce cost, time and effort. However, software quality characteristics cannot be directly measured but they can be estimated based on other measurable software attributes (such as coupling, size and complexity). Software quality estimation models establish a relationship between the unmeasurable characteristics and the measurable attributes. However, these models are hard to generalize and reuse on new, unseen software as their accuracy deteriorates significantly. In this paper, we present a genetic algorithm that adapts such models to new data. We give empirical evidence illustrating that our approach out-beats the machine learning algorithm C4.5 and random guess.


2020 ◽  
Vol 12 (1) ◽  
pp. 126 ◽  
Author(s):  
Jayan Wijesingha ◽  
Thomas Astor ◽  
Damian Schulze-Brüninghoff ◽  
Matthias Wengert ◽  
Michael Wachendorf

The timely knowledge of forage quality of grasslands is vital for matching the demands in animal feeding. Remote sensing (RS) is a promising tool for estimating field-scale forage quality compared with traditional methods, which usually do not provide equally detailed information. However, the applicability of RS prediction models depends on the variability of the underlying calibration data, which can be brought about by the inclusion of a multitude of grassland types and management practices in the model development. Major aims of this study were (i) to build forage quality estimation models for multiple grassland types based on an unmanned aerial vehicle (UAV)-borne imaging spectroscopy and (ii) to generate forage quality distribution maps using the best models obtained. The study examined data from eight grasslands in northern Hesse, Germany, which largely differed in terms of vegetation type and cutting regime. The UAV with a hyperspectral camera on board was utilised to acquire spectral images from the grasslands, and crude protein (CP) and acid detergent fibre (ADF) concentration of the forage was assessed at each cut. Five predictive modelling regression algorithms were applied to develop quality estimation models. Further, grassland forage quality distribution maps were created using the best models developed. The normalised spectral reflectance data showed the strongest relationship with both CP and ADF concentration. From all predictive algorithms, support vector regression provided the highest precision and accuracy for CP estimation (median normalised root mean square error prediction (nRMSEp) = 10.6%), while cubist regression model proved best for ADF estimation (median nRMSEp = 13.4%). The maps generated for both CP and ADF showed a distinct spatial variation in forage quality values for the different grasslands and cutting regimes. Overall, the results disclose that UAV-borne imaging spectroscopy, in combination with predictive modelling, provides a promising tool for accurate forage quality estimation of multiple grasslands.


Author(s):  
Kehan Gao ◽  
Taghi M. Khoshgoftaar

Timely and accurate prediction of the quality of software modules in the early stages of the software development life cycle is very important in the field of software reliability engineering. With such predictions, a software quality assurance team can assign the limited quality improvement resources to the needed areas and prevent problems from occurring during system operation. Software metrics-based quality estimation models are tools that can achieve such predictions. They are generally of two types: a classification model that predicts the class membership of modules into two or more quality-based classes (Khoshgoftaar et al., 2005b), and a quantitative prediction model that estimates the number of faults (or some other quality factor) that are likely to occur in software modules (Ohlsson et al., 1998). In recent years, a variety of techniques have been developed for software quality estimation (Briand et al., 2002; Khoshgoftaar et al., 2002; Ohlsson et al., 1998; Ping et al., 2002), most of which are suited for either prediction or classification, but not for both. For example, logistic regression (Khoshgoftaar & Allen, 1999) can only be used for classification, whereas multiple linear regression (Ohlsson et al., 1998) can only be used for prediction. Some software quality estimation techniques, such as case-based reasoning (Khoshgoftaar & Seliya, 2003), can be used to calibrate both prediction and classification models, however, they require distinct modeling approaches for both types of models. In contrast to such software quality estimation methods, count models such as the Poisson regression model (PRM) and the zero-inflated Poisson (ziP) regression model (Khoshgoftaar et al., 2001) can be applied to yield both with just one modeling approach. Moreover, count models are capable of providing the probability that a module has a given number of faults. Despite the attractiveness of calibrating software quality estimation models with count modeling techniques, we feel that their application in software reliability engineering has been very limited (Khoshgoftaar et al., 2001). This study can be used as a basis for assessing the usefulness of count models for predicting the number of faults and quality-based class of software modules.


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