Artur Janicki

Artur Janicki
Warsaw University of Technology · Institute of Telecommunications

PhD

About

54
Publications
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424
Citations

Publications

Publications (54)
Article
Full-text available
In this article we address the problem of efficient and secure monitoring of computer network traffic. We proposed, implemented, and tested a hardware-accelerated implementation of a network probe, using the DE5-Net FPGA development platform. We showed that even when using a cryptographic SHA-3 hash function, the probe uses less than 17% of the ava...
Article
Full-text available
In this article, we address the problem of detecting anomalies in system log files. Computer systems generate huge numbers of events, which are noted in event log files. While most of them report normal actions, an unusual entry may inform about a failure or malware infection. A human operator may easily miss such an entry; therefore, anomaly detec...
Article
Full-text available
In this article, the problem of detecting JPEG images, which have been steganographically manipulated, is discussed. The performance of employing various shallow and deep learning algorithms in image steganography detection is analyzed. The data, images from the BOSS database, were used with information hidden using three popular steganographic alg...
Article
The influence of personal internal resources (IRs) on coping with traumatic events is constantly researched. This study aimed to determine how the SARS-CoV-2 pandemic affected anxiety, depression , and loneliness in two groups at different levels of exposure (low and high) to the infection. We analysed the impact of IRs in the form of the level of...
Conference Paper
Full-text available
Information hiding techniques are becoming a major threat in network communication. This paper describes how to modify an intrusion detection system (IDS) to detect certain types of steganography. As a sample IDS we use open-source Zeek software. We show how to adapt it for the purpose of steganalysis. Additionally, we propose a set of validation t...
Article
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In this article, we present the results of our experiments on sentiment and emotion recognition for English and Polish texts, aiming to work in the context of a therapeutic chatbot. We created a dedicated dataset by adding samples of neutral texts to an existing English-language emotion-labeled corpus. Next, using neural machine translation, we dev...
Article
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Cyber attacks are currently blooming, as the attackers reap significant profits from them and face a limited risk when compared to committing the “classical” crimes. One of the major components that leads to the successful compromising of the targeted system is malicious software. It allows using the victim’s machine for various nefarious purposes,...
Conference Paper
In this paper we propose an improved system for the detection of end of speech (EOS) events in noisy environments, needed, for example, in voice interfaces of mobile devices. Our solution is based on a deep neural network composed of convolutional, feed-forward and LSTM layers. For the input data we use mel-frequency cepstral coefficients (MFCC). T...
Conference Paper
Full-text available
The article presents a method of using F0 parameter in speech coding to transmit hidden information. It is an improved approach, which uses interpolation of pitch parameters instead of transmitting exact original values. Using an example of the Speex codec, we describe six variants of this method, named originally as HideF0, and we compare them by...
Conference Paper
Full-text available
In this article we present the Leyzer dataset, a multilingual text corpus designed to study multilingual and cross-lingual natural language understanding (NLU) models and the strategies of localization of virtual assistants. The proposed corpus consists of 20 domains across three languages: English, Spanish and Polish, with 186 intents and a wide r...
Article
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The Internet of Things (IoT) concept has been widely adopted and Internet connected devices enter more and more areas of our everyday lives. However, their limited security measures raise increasing concerns, especially in terms of users’ privacy. That is why, in this paper, privacy risks, focusing primarily on information leakage exposed by traffi...
Article
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Purpose: Description of cognitive behavioural therapy (CBT) of a patient diagnosed with paranoid schizophrenia, who experienced chronic negative auditory hallucinations (voices). Case description: Elements of CBT complemented by the use of virtual reality were described. Stages of the therapy of a 40-year-old patient hearing voices constantly for 7...
Article
Artykuł prezentuje próbę analizy zadowolenia mówcy na podstawie sygnału mowy. Na podstawie rzeczywistych rozmów z call center stworzono korpus mowy oraz przeprowadzono wstępne testy, których celem było określenie możliwości automatycznego wykrywania niezadowolenia w głosie. Podczas eksperymentów 1179 nagrań poddano automatycznej klasyfikacji, uzys...
Conference Paper
In this article we propose using speech synthesis in the therapy of auditory verbal hallucinations, which are sometimes called “voices”. During a therapeutic session a patient converses with an avatar, which is controlled by a therapist. The avatar, based on the XFace model and commercial text-to-speech systems, uses a high quality synthetic voice...
Article
Full-text available
This article addresses the problem of anti-spoofing protection in an automatic speaker verification (ASV) system. An improved version of a previously proposed spoofing countermeasure is presented. The presented method is based on the analysis of linear prediction error that results from both short- and long-term prediction of the input speech signa...
Article
This paper analyses the threat of replay spoofing or presentation attacks in the context of automatic speaker verification. As relatively high-technology attacks, speech synthesis and voice conversion, which have thus far received far greater attention in the literature, are probably beyond the means of the average fraudster. The implementation of...
Article
This paper presents an improved version of a steganographic algorithm for IP telephony called HideF0. It is based on approximating the F0 parameter, which is responsible for conveying information about the pitch of the speech signal. The bits saved due to simplification of the pitch contour are used for the hidden transmission. In our experiments,...
Article
W artykule przedstawiono problem rosnących zagrożeń dla systemów weryfikacji mówcy (ang. ASV). Po omówieniu używanych obecnie algorytmów służących do biometrii głosowej przedstawiono, w jaki sposób systemy ASV mogą zostać skompromitowane przez osoby podszywające się pod inną tożsamość (ang. spoofing). Omówiono główne rodzaje ataków, takich jak atak...
Article
Full-text available
In this paper we propose a new method for the evaluation of network steganography algorithms based on the new concept of "the moving observer". We considered three levels of undetectability named: "good", "bad", and "ugly". To illustrate this method we chose Wi-Fi steganography as a solid family of information hiding protocols. We present the state...
Conference Paper
In this paper a novel steganographic method, called Hide F0, dedicated to IP telephony is proposed. It is based on the approximation of the parameter that describes the F0 frequency (the pitch) of the speaker's voice. We show that thanks to approximating some fragments of the "fine pitch" parameter in the Speex codec we can create efficient hidden...
Article
Full-text available
In this paper a new information hiding method for Skype videoconference calls – YouSkyde – is introduced. A Skype traffic analysis revealed that introducing intentional losses into the Skype video traffic stream to provide the means for clandestine communication is the most favourable solution. A YouSkyde proof-of-concept implementation was carried...
Article
Transcoding Steganography (TranSteg) is a fairly new IP telephony steganographic method that is characterized by a high steganographic bandwidth, low introduced distortions, and high undetectability. TranSteg utilizes compression of the overt data to free space for the secret data bits. In this paper, we focus on evaluating different possibilities...
Article
This paper addresses the problem of older adults’ understanding of speech. By analyzing speech rates used by various radio stations and by confronting them with audience ratings we found that there is some correlation between speech rate used by radio stations and audience preferences in different age groups. We present various studies analyzing th...
Article
Nowadays cyber criminalists’ interest in incorporation of steganography into armory of rogue hackers is on the rise and information hiding techniques are becoming the new black among Black Hats. In this paper we focus on analyzing the efficiency of the recently proposed IP telephony information hiding method called transcoding steganography (TranSt...
Article
This paper re-examines the threat of spoofing or presentation attacks in the context of automatic speaker verification (ASV). While voice conversion and speech synthesis attacks present a serious threat, and have accordingly received a great deal of attention in the recent literature, they can only be implemented with a high level of technical know...
Article
Full-text available
This paper describes a study of emotion recognition based on speech analysis. The introduction to the theory contains a review of emotion inventories used in various studies of emotion recognition as well as the speech corpora applied, methods of speech parametrization, and the most commonly employed classification algorithms. In the current study...
Article
The paper describes the performance of a task-oriented continuous automatic speech recognition (ASR) system in the computer game interface in noisy conditions. First, the process of designing the ASR system for Polish, based on CMU Sphinx4, is presented. Then, the concept of the computer game called Rally Navigator is described. The exper- iments w...
Article
This paper describes an algorithm for detection of nonlinguistic vocalisations, such as laughter or fillers, based on acoustic features. The algorithm proposed combines the benefits of Gaussian mixture models (GMM) and the advantages of support vector machines (SVMs). Three GMMs were trained for garbage, laughter, and fillers, and then an SVM model...
Article
Full-text available
TranSteg (Trancoding Steganography) is a fairly new IP telephony steganographic method that functions by compressing overt (voice) data to make space for the steganogram by means of transcoding. It offers high steganographic bandwidth, retains good voice quality and is generally harder to detect than other existing VoIP steganographic methods. In T...
Conference Paper
This paper investigates the impact of non-speech sounds on the performance of speaker recognition. Various experiments were conducted to check what the accuracy of speaker classification would be if non-speech sounds, such as breaths, were removed from the training and/or testing speech. Experiments were run using the GMM-UBM algorithm and speech t...
Article
This study investigated whether it is possible to train a machine to discriminate levels of extraversion based on handwriting variables. Support vector machines (SVMs) were used as a learning algorithm. Handwriting of 883 people (404 men, 479 women) was examined. Extraversion was measured using the Polish version of the NEO-Five Factor Inventory. T...
Article
Full-text available
The typical approach to steganography is to compress the covert data in order to limit its size, which is reasonable in the context of a limited steganographic bandwidth. TranSteg (Trancoding Steganography) is a new IP telephony steganographic method that was recently proposed that offers high steganographic bandwidth while retaining good voice qua...
Conference Paper
This paper describes experiments with speaker verification using support vector machines (SVMs). Verification from coded and uncoded speech is analyzed, both in matched and mismatched conditions. A hybrid SVM-GMM approach is used, in which SVM classifiers with Kullback-Leibler kernel make verification decisions based on the mean values of Gaussian...
Conference Paper
Full-text available
We proposed to use support vector machines (SVMs) to recognize speakers from signal transcoded with different speech codecs. Experiments with SVM-based text-independent speaker classification using a linear GMM supervector kernel were presented for six different codecs and uncoded speech. Both matched (the same codec for creating speaker models and...
Conference Paper
Full-text available
The paper describes the process of designing a task-oriented continuous speech recognition system for Polish, based on CMU Sphinx 4, to be used in the voice interface of a computer game called Rally Navigator. The concept of the game is presented, the stages of creating the acoustic model and the language model are described in details, taking into...
Article
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This paper is about designing visual speech synthesis system for Polish. Xface toolkit with keyframe interpolation based animation was chosen as animation method. The paper describes designing the “Karol” face model and Polish visemes. The idea of using half-visemes was proposed for synthesizing fast visual speech, and it was verified during testin...
Conference Paper
Full-text available
The paper presents how to take advantage of pronunciation variation when constructing a speech synthesis system for Polish, so that even a small speech corpus can be sufficient to produce intelligible and good quality speech. The system uses a unit selection algorithm based directly on linguistic features of the input text, without using a prosody...
Article
In this chapter, the authors propose an algorithm for packet loss concealment (PLC) in transmission over IP-based networks with high packet loss rate. The algorithm is a sender-receiver-based extension of ANSI T1.521a Annex B PLC standard for G.711 voice codec. It consists in adding to a transmitted packet redundant parameters describing speech sig...
Article
Full-text available
This document describes a method how to increase effectiveness of speaker recognition, based on Gaussian mixture models (GMM), in the presence of noise. The method consists in using a voice activity detector (VAD) and training it to given environmental conditions. The system has been verified for 44 Polish speakers for different types of noise and...
Article
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A text-to-speech (TTS) system for the Polish language is described. It is based on the concatenation of diphones using the Time-Domain PSOLA technique, with appropriate prosody control. The general features of the system and the prosody control algorithms are addressed. They include text preprocessing, grapheme-to-phoneme conversion, construction o...
Article
Full-text available
The paper describes use of neural networks in POS (part-of-speech) tagging and intonation control, needed in a speech synthesis system for the Polish language. Feedforward multilayered perceptrons have been proposed for both purposes. Considerations during planning the network architecture, used training data, training process and verification of t...

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Projects (5)
Project
The aim of the project is to use computer techniques (e.g., speech processing, computer animation, avatars) in therapy of psychotic disorders, such as hallucinations.