Ingrid Bönninger

Ingrid Bönninger


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2019 in Electronics
Verified
Journal Article
Open access
PDF file
TKTobias Kutzner
Tobias Kutzner
CPCarlos Pazmiño
Carlos Pazmiño
MGMatthias Gebhard
Matthias Gebhard
IBIngrid Bönninger
Ingrid Bönninger
WPWolf-Dietrich Plath
Wolf-Dietrich Plath
Carlos M. Travieso-GonzálezCarlos M. Travieso-González
Carlos M. Travieso-González
One of the biometric methods in authentication systems is the writer verification/identification using password handwriting. The main objective of this paper is to present a robust writer verification system by using cursive texts as well as block letter words. To evaluate the system, two datasets have been used. One of them is called Secure Password DB 150, which is composed of 150 users with 18 samples of single character words per user. Another dataset is public and called IAM online handwriting database, and it is composed of 220 users of cursive text samples. Each sample has been defined by a set of features, composed of 67 geometrical, statistical, and temporal features. In order to get more discriminative information, two feature reduction methods have been applied, Fisher Score and Info Gain Attribute Evaluation. Finally, the classification system has been implemented by hold-out cross validation and k-folds cross validation strategies for three different classifiers, K-NN, Naïve Bayes and Bayes Net classifiers. Besides, it has been applied for verification and identification approaches. The best results of 95.38% correct classification are achieved by using the k-nearest neighbor classifier for single character DB. A feature reduction by Info Gain Attribute Evaluation improves the results for Naïve Bayes Classifier to 98.34% for IAM online handwriting DB. It is concluded that the set of features and its reduction are a strong selection for the based-password handwritten writer identification in comparison with the state-of-the-art.

3 December 2019 in Electronics
Verified
Journal Article
Open access
PDF file
TSTobias Steinmetzer
Tobias Steinmetzer
MMMichele Maasch
Michele Maasch
IBIngrid Bönninger
Ingrid Bönninger
Carlos M. Travieso-GonzálezCarlos M. Travieso-González
Carlos M. Travieso-González
Due to increasing life expectancy, the number of age-related diseases with motor dysfunctions (MD) such as Parkinson’s disease (PD) is also increasing. The assessment of MD is visual and therefore subjective. For this reason, many researchers are working on an objective evaluation. Most of the research on gait analysis deals with the analysis of leg movement. The analysis of arm movement is also important for the assessment of gait disorders. This work deals with the analysis of the arm swing by using wearable inertial sensors. A total of 250 records of 39 different subjects were used for this task. Fifteen subjects of this group had motor dysfunctions (MD). The subjects had to perform the standardized Timed Up and Go (TUG) test to ensure that the recordings were comparable. The data were classified by using the wavelet transformation, a convolutional neural network (CNN), and weight voting. During the classification, single signals, as well as signal combinations were observed. We were able to detect MD with an accuracy of 93.4% by using the wavelet transformation and a three-layer CNN architecture.

31 January 2022 in Uniciencia
Verified
Journal Article
Open access
PDF file
TSTobias Steinmetzer
Tobias Steinmetzer
IBIngrid Bönninger
Ingrid Bönninger
Carlos M. Travieso-GonzálezCarlos M. Travieso-González
Carlos M. Travieso-González
In this paper we propose a new method for symmetry calculation in wearable devices. The problem in this domain is that only discrete features such as stride length, stride duration, or duration of gait phases are used for the symmetry calculation. However, this can lead to failures, since the use of features can result in partial loss of information from the time series. From this we present a possibility to calculate the symmetry by using Dynamic Time Warping (DTW). DTW uses the complete time series for the analysis and is therefore independent of certain features.