69 research outputs found
Analysis of Hue Spectra During Storage of Pepper (Capsicum annuum)
Color information is widely used in non-destructive quality assessment of perishable horticultural produces. The presented work investigated color changes of pepper (Capsicum annuum L.) samples received from retail system. The effect of storage temperature (10±2°C
and 24±4°C) on surface color and firmness was analyzed. Hue spectra was calculated using
sum of saturations. A ColorLite sph850 (400-700nm) spectrophotometer was used as
reference instrument. Dynamic firmness was measured on three locations of the surface: tip
cap, middle and shoulder. Significant effects of storage conditions and surface location on
both color and firmness were observed. Hue spectra responded sensitively to color
development of pepper. Prediction model (PLS) was used to estimate dynamic firmess
based on hue spectra. Accuracy was very different depending on the location. Firmness of
the tip cap was predicted with the highest accuracy (RMSEP=0.0335). On the other hand,
middle region cannot be used for such purpose. Due to the simplicity and rapid processing,
analysis of hue spectra is a promising tool for evaluation of color in postharvest and food
industry
CLASSIFIER COMBINATION IN SPEECH RECOGNITION
In statistical pattern recognition, the principal task is to
classify abstract data sets. Instead of using robust but
computational expensive algorithms it is possible to combine
`weak´ classifiers that can be employed in solving complex
classification tasks.
In this comparative study,
we will examine the effectiveness of the commonly used hybrid
schemes - especially those used for speech recognition problems -
concentrating on cases which employ different combinations of
classifiers
Various robust search methods in a Hungarian speech recognition system
This work focuses on the search aspect of speech recognition. We describe some standard algorithms such as stack decoding, multi-stack decoding, the Viterbi beam search and an A* heuristic, then present improvements on these search methods. Finally we compare the performance of each algorithm, grading them according to their performance. We will show that our improvements can outperform the standard methods
Preparation of New 2,3-Diphenylpropenoic Acid Esters – Good Yields Even for the More Hindered Z Isomers
The potassium salt of E- and Z-2,3-diphenylpropenoic acids prepared in situ could be esterified efficiently in DMSO with the appropriate alkyl halides at room temperature. In this way 10 previously undescribed esters of these acids were synthesised and characterised. Excellent yields were observed for most of the E isomers and the more hindered Z esters were also obtained in good yields, far better than those obtained applying the classical acid-catalysed esterification reaction
Classifier combination schemes in speech impediment therapy systems
In the therapy of the hearing impaired one of the key problems is how to deal with the lack of proper auditive feedback which impedes the development of intelligible speech. The effectiveness of the therapy relies heavily on accurate phoneme recognition [1, 4, 17]. Because of the environmental difficulties, simple recognition algorithms may have a weak classification performance, so various techniques such as normalization and classifier combination are applied to increase the recognition accuracy. This paper examines Vocal Tract Length Normalization techniques [5, 13] focusing mainly on the real-time parameter estimation [12], and the majority of classifier combination schemes, including the traditional (Prod, Sum, Min, Max) [7], basic linear (simple, weighted, AHP-based [6] averaging), and some special linear (Bagging, Boosting) combinations. Based on the results we conclude that hybrid combinations can improve the effectiveness of the real-time normalization methods
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