» Audio features for speech detection in adverse conditions
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TOMASZ MĄKA 
Effectiveness of automatic audio and speech processing
systems rely on properties of source signal: acquisition environment,
type of signal (audio event, music clip, speech,
etc.) and it varies with the recording conditions and equipment.
The task of identification of particular type of signal
in audio stream is currently widely studied in literature [4].
Each class of signal has to be treated independently in order
to different applications. For example, automatic speech
recognition (ASR), speaker identification, verification and
separation systems assume speech as input signal and can
give unpredictable results for others, diminishing overall
accuracy. Similarly, in audio coding systems it is important
to use separate, dedicated coders for speech and music for
better coding efficiency [4, 13]. Therefore, obtained regions
in identification process for defined class of signal are employed
in segmentation and extraction of input audio stream
for final application. The accuracy of detected regions depends
on type of features describing signal properties and
the influence of external conditions like noise, coding effects,
etc [3, 12].
One of critical problems in speech/audio applications is
determination of existence voice in signal. Algorithms for such
tasks are called VAD (Voice Activity Detection) and play main
role in voice transmission systems. The main goal of VAD
is to indicate regions of voice occurrence in input audio stream.
As a result, they contribute to lower bandwidth usage [3, 5, 9].
Noisy robustness is one of key elements of VAD efficiency, but
prediction of detection accuracy in different types of noise is
difficult to accomplish. Despite many existing approaches
to speech detection, the sensitivity problem of audio features
on different types of noise is still exist [...]
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ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA 2010/4
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» Properties of feature contours for audio classification tasks
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TOMASZ MĄKA
Increasing technological advances stimulates development of
fully automated speech/audio interaction systems in everyday
life. Such systems include various modules to handle different
acoustical streams like speech, music, background noises,
events, etc. Additionally, there are systems that use extra information
from video streams or data captured from dedicated sensors
to improve their efficiency in human-machine interaction
and interactive multimodal tasks [1]. However, the final effectiveness
is still highly dependent on audio processing stage.
The processing flow involve two basic steps: segmentation
and classification [2-3]. In the segmentation phase input
signal is divided into regions, where important audio information
from interaction point of view can be extracted. Then, for
every region audio classification is performed. Due to high
sensitivity on the variable external audio conditions, selection
of features with good separability properties for a given
set of classes is crucial [4-5]. Nevertheless in many systems
a feature set is selected arbitrary [6]. Typical audio classification
phase works in the following manner: first, input signal
is divided into short frames, then for each frame a set of audio
features is computed making feature vector. Every vector
is labeled with signal class and then used in learning phase
where database is created. Finally, obtained database is exploited
in the classification process [7]. The main obstacle in
such approach is the impossibility of features modification (for
adaptation to changing conditions) without repeating learning
phas[...]
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ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA 2010/11
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» Analyzing feature trajectories for audio content discrimination
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Tomasz Mąka
The field of audio information indexing and retrieval needs audio
analysis tasks like segmentation and classification. Its growing
popularity and numerous applications are connected with the
availability of huge audio resources on the Internet. The large variability
of audio content in such resources has direct influence on
effectiveness and usability of audio management systems. Audio
data categorization or searching by listening seems to be difficult
task, thus automatic and effective mechanism is required to explore
data. Typical audio retrieval system involves three steps:
segmentation, feature extraction and classification. The final efficiency
is dependent on all these steps and audio acquisition
environment. Segmentation and classification processes are performed
on the features variability basis, thus the choice of audio
features set with good discrimination properties is important. It is
still difficult to decide how big should be feature set and what kind
of features should be selected. Therefore, to determine set of audio
features for selected number of classes the feature selection
step is introduced in audio analysis systems. The type of source
audio data determines the specificity of classification stage.
The most common audio classification task is to determine
speech regions in input signal. In such case, the binary discrimination
between speech and non-speech parts is performed. Automatic
systems for audio classification usually categorize sound
segments into several groups. For example, in broadcast news
material, determination between speech and music is executed
at first stage. At subsequent stages, an analysis of mixtures (speech
with background music or environmental noise) and specific
signals (silence, noise) is often considered.
Audio segmentation as the first process performed in automatic
systems for audio classification is mostly based on Bayesian
Information Criterion (BIC) se[...]
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ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA 2011/10
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» Flexible packet scheduling algorithm utilization for on-chip networks
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PAWEŁ STOLARSKI TOMASZ MĄKA PIOTR DZIURZAŃSKI
Using contemporary technology, it is possible to implement a
large number of computational units inside a single chip. Such
kind of chip is usually referred to as System on Chip - SoC.
A typical system of this type is usually composed of computational
elements, I/O interfaces, memory, and communication
infrastructure. Due to the continuously increasing complexity of
these systems and low scalability of inner connections, system
cores are connected with Network on Chip (NoC) [1].
These networks are an alternative to the state-of-the-art point
to point or bus-based connections and, similarly to buses, they
offer an universal interface for connecting SoC elements. However,
NoCs guarantee better electrical parameters of transmitted
signals, higher bandwidth and are capobility of tr[...]
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ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA 2009/6
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» The impact of the type of sung vowels on the singing quality
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Edward Półrolniczak Mirosław Łazoryszczak Tomasz Mąka
An assessment of the singing voice quality can be considered
on many levels and thus is a complex process. Such process
is influenced by technical skills or medical aspects. The quality
of singing may be affected by technical skills of the singer.
Some shortcomings can be observed in the intonation while singing,
others may occur in timbre as the effect of “clamped throat",
metallic or roaring sound. A similar symptoms, induced by physiological
diseases (like hoarseness or sudden jumps in pitch), may
be reported in case of technical imperfections. The evaluation of
quality of singing voice can not be treated separately from quality
of singing; many articles omit this connection. A long-term training
experience is helpful to achieve high quality of singing. It leads to
diminishing or even avoiding mistakes in the case of emission of
unusual melodic sets which are difficult for the vocal.
From a medical point of view the quality of voice is examined
for voice apparatus diseases. There are various diseases that are
common in singers. One of them are nodules of vocal cords [1],
caused by unskilful singing with the effect of clenched around-laryngeal
muscles. Micro damages, abrasions, wounds and small
scars of vocal cords and nodules are problems caused by permanent
lack of singing technique. Unskilful use of voice can lead to
the loss of any ability to produce the sound in the sense of music. If
this situation occurs longer, it will lead to a complete loss of voice.
Regurgitation of the vocal cords may be another ailment [2] which
is manifested by soundlessness in speech and singing similar to
a hoarse whisper. Some other problems may be caused by the
congestion and swelling of vocal cords due to overload, alcohol,
or respiratory disease. Inability to achieve high notes effortlessly
is the symptom of these disorders. Dried vocal cords (because of
poor body hydration) or nicotine can cause a sudden change from
closed to open [...]
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ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA 2011/11
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» Time constraints analysis of data-driven multimedia algorithms in Networks on Chip
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Bartosz Chojnacki Tomasz Mąka Piotr Dziurzański
Modern multimedia algorithms are usually data-dominated and
require an immense amount of computation [14, 15]. However,
these algorithms can be divided into stages that are implementable
in separate units of computation (cores). Thanks to this property,
they can use parallel and distributed computing working in a manner
similar to pipeline and transfer their streams in the form of
relatively large, but usually fixed amount of data. In these applications,
it is usually required to maintain the established quality
of service and satisfy the constraints in real-time [15]. Multi-Processor
System on Chips (MPSoCs) are often considered as the
best tailored hardware for these applications [10]. In each of the
MPSoC processing units one processing step can be computed,
but it is still a problem to connect these units together.
The simplest point to point (P2P) connections require too much
space, and the bus-based connections linking a large number of
cores result in many conflicts and, consequently, in spite of various
arbitration techniques, decrease the overall system performance
[11]. In addition, both P2P and bus-projects do not scale well with
the growing number of independent intellectual property (IP) cores
required by contemporary hardware to deal with a number of different
algorithms in a single system [2]. To overcome these obstacles,
a Network-on-Chip (NoC) design paradigm for implementing
distributed computing systems has been introduced [4]. The growing
popularity of this approach can be attributed to fewer conflicts
in a chip with many cores in comparison with the traditional approaches.
It is reported that the NoC architecture offers high throughput
and reliable communication, but requires additional mechanisms
to overcome the problems typical for packet switching communication,
such as packet deadlock or starvation. Due to the difference
with the traditional computer networks, popular techniques for dealing
with these [...]
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ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA 2011/11
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