Adam Wojciechowski

Lodz University of Technology · Institute of Information Technology

Desynchronization attacks proved to be the greatest challenge to audio watermarking systems as they introduce misalignment between the signal carrier and the watermark. This paper proposes a DNN-based speech watermarking system with two adversarial networks jointly trained on a set of desynchronization attacks to embed a randomly generated watermar...

The present work examines the analytical solutions of the double duffusive magneto free convective flow of Oldroyd-B fluid model of an inclined plate saturated in a porous media, either fixed or moving oscillated with existence of slanted externally magnetic field. The phenomenon has been expressed in terms of partial differential equations, then t...

The behavior of gas diffusion in a homogeneous medium is described by the (2+1)-dimensional Chaffee-Infante equation. In this work, the solitary wave behavior of the (2+1)-dimensional Chaffee-Infante equation is studied with the help of extended sinh-Gordon equation expansion technique. Bright, dark, periodic, kink, anti-kink and singular traveling...

Nowadays, the process of cognitive or motor rehabilitation is mostly implemented in a traditional form. Paper-pencil cognitive exercises or physical exercises with instruments still dominate over digital environments. However, they require constant supervision by professionals, whose availability is relatively decreasing in an ageing society. Lack...

In this paper, we propose GVA-net, a fully-convolutional architecture for point cloud classification and part-segmentation. We prove that the hierarchical of the receptive field among the permutation-constant neighborhood leads to better mean accuracy on the benchmark ModelNet40 dataset by 0.7pp with respect to the best method relying on local cont...

The aim of this article is to investigate the exact solution by using a new approach for the thermal transport phenomena of second grade fluid flow under the impact of MHD along with exponential heating as well as Darcy’s law. The phenomenon has been expressed in terms of partial differential equations, then transformed the governing equations in n...

In this manuscript, the novel auxiliary equation methodology (NAEM) is employed to scrutinize various forms of solitary wave solutions for the modified equal-width wave (MEW) equation. M-truncated along with Atangana–Baleanu (AB)-fractional derivatives are employed to study the soliton solutions of the problem. The fractional MEW equations are impo...

Human-technology relations are time and place related processes. Today, it is very common to describe human-technology interaction by stating that technology is ubiquitous and permeating all aspects of our everyday lives. This is often compounded by the fact that technological development has been rapid, and it seems to be accelerating. This speed...

Virtual Reality (VR) combined with near real-time EEG signal processing can be used as an improvement to already existing rehabilitation techniques, enabling practitioners and therapists to get immersed into a virtual environment together with patients. The goal of this study is to propose a classification model along with all preprocessing and fea...

In this study, we present the confirmation of existence of the correlation of the image features with the computer game level Impression Curve. Even a single image feature can describe the impression value with good precision (significant strong relationship, Pearson r> 0,5). Best results were obtained using by combining several image features usin...

One of the most important issues in the context of contemporary research on a human body biomechanics is musculoskeletal models. It turns out that the need for biomechanically correct movement model is enormous not only in medicine and rehabilitation, but also in animations synthesis with computer game engines, where unsightly effects often occur b...

Computer games are currently the most complex interactive medium. Understanding how to manipulate the player’s attention avoids getting lost in the environment while the player is receiving a significant amount of audiovisual stimuli. By appropriately selecting the visual aspects of the environment, player navigation can be aided. This article focu...

This paper utilizes deep neural networks for robust digital watermarking and authentication of speech signals. We present two adversarial neural networks, called embedder and detector. The embedder network tends to achieve imperceptible watermark embedding by minimizing the differences between the original and watermarked signals. The detector stri...

Geothermal energy can be an attractive source of renewable energy in many respects. The purpose of this paper is to assess the role of geothermal energy in the West Pomeranian Region of Poland. The article presents the key principles of geothermal energy development, its role, functions and perspectives in fostering renewable energy usage in the re...

China’s high-speed railway has become world-famous, how to realize the safe operation of the high-speed railway passing through the mined-out areas in China will face many new challenges. To reveal the deformation and dynamic response characteristics of the track structure and subgrade of the high-speed railway above the mined-out areas, the modeli...

The contemporary development of immersive virtual reality interfaces holds untapped potential for the rehabilitation and motor-cognitive training of older adults. Despite the parallel development of gamification methods involving users in interactive experiences and the dynamic development of sensors and techniques for tracking human bio-physiologi...

Modern visionaries claim supernatural abilities to artificial intelligence. Artificial intelligence has been attributed artistic skills, including those related to the visual arts. Is artificial intelligence a creator, or maybe it is the creators of algorithms who have to be creative, whose imagination is then transformed into works-of-art by a com...

The set covering problem is a fundamental model which comprises a wide range of important applications such as crew scheduling problems that need to cover a set of trips. It is one of the most common issues in the facility location problem, which requires further investigations, particularly in emergency and service facilities. As such, the objecti...

The monograph TEWI 2021 is a direct response to the demand of the industry, which looks for research projects partners. On the one hand, the material submitted for this monograph will give opportunity for the academic community to present their competencies in the thematic areas of research they conduct. On the other hand, the industry will stimula...

The article aims to identify the latest trends in research on renewable energy, sustainability and the environment. A total of 92,873 publications from 123 Scopus sources for 2020–2021 are compared using the scoping review method. The results show that the most cited works in this sample are those by authors from the Asian region. The research of t...

In this study, we analyze and identify a proper scale value when presenting real world space and everyday objects in immerse VR. We verify the impact of usage of reference points in the form of common objects known to the user such as windows, doors and furniture in the sense of scale in VR. We also analyze user behavior (position, rotation, moveme...

One of the outstanding benchmark architectures for point cloud processing with graph-based structures is Dynamic Graph Convolutional Neural Network (DGCNN). Though it works well for classification of nearly perfectly described digital models, it leaves much to be desired for real-life cases burdened with noise and 3D scanning shadows. Therefore we...

Emotions play an important role in everyday life and contribute to physical and emotional well-being. They can be identified by verbal or non-verbal signs. Emotional states can be also detected by electroencephalography (EEG signals). However, efficient information retrieval from the EEG sensors is a difficult and complex task due to noise from the...

The challenge of EEG-based emotion recognition had inspired researchers for years. However, lack of efficient technologies and methods of EEG signal analysis hindered the development of successful solutions in this domain. Recent advancements in deep convolutional neural networks (CNN), facilitating automatic signal feature extraction and classific...

Sustainable development can be achieved when economic development does not produce environmental deterioration. In this context, the aim of the paper is to evaluate the effects of economic development on GHG emissions in the Baltic States (Latvia, Letonia, and Lithuania), and in Hungary, the Czech Republic, Slovakia, and Poland (the Visegrád Group...

In computer graphics, the efficient rendering of a clear sky may greatly enhance the realism of synthesised interactive virtual environments. However, light atmospheric scattering, lying behind a reliable sky synthesis, is a computationally demanding process. Obtaining the highest possible accuracy and quality of the synthesised image in an efficie...

Using the direct variational method together with the monotonicity approach we consider the existence of non-spurious solutions to the following Dirichlet problem −x¨(t)=f(t,x(t)), x(0)=x(1)=0, where f:[0,1]×R→R is a jointly continuous and not necessarily convex function. A new approach towards deriving the discrete family of approximating problems...

The effects of the labor market on environmental issues are an actual problem at the global level, and recommendations are required to achieve equilibrium between labor productivity and environmental protection. Considering the ecological limits of work and the necessity of reducing the working time to mitigate GHG (greenhouse gas) emissions, this...

Skeletal animation being one of the most distinct technics in real-time computer graphic is constantly evolving, since the time it was first implemented. New features, methods of synthesis and processing are being actively worked on and shipped in commercial titles. One missing aspect of this subbranch of rendering is proper automatic validation fo...

Content-based image retrieval methods develop rapidly with a growing scale of image repositories. They are usually based on comparing and indexing some image features. We developed a new algorithm for finding objects in images by traversing their edges. Moreover, we describe the objects by histograms of local features and angles. We use such a desc...

Precise segmentation/partition is an essential part of many point cloud processing strategies. In the state-of-the-art methods, either the number of clusters or expected supervoxel resolution needs to be carefully selected before segmentation. This makes these processes semi-supervised. The proposed Normal Grouping- Density Separation (NGDS) strate...

Objective: Modern technologies are increasingly used in the development of cognitive interventions for older adults. Research into possible applications of virtual reality in such interventions has begun only recently. The aim of present study was to evaluate the effects of 8 sessions of VR-based cognitive training using the GRADYS game in healthy...

Point cloud segmentation for planar surface detection is a valid problem of automatic laser scans analysis. It is widely exploited for many industrial remote sensing tasks, such as LIDAR city scanning, creating inventories of buildings, or object reconstruction. Many current methods rely on robustly calculated covariance and centroid for plane mode...

Correct modelling of human muscle is very difficult issue. The digital model can be used for understandig, how the muscle works, what kinds of processes take places during their work. It can be also used for check correctness of animation synteze. Researchers have developed many methods for creating shoulder models. They differ not only in the appr...

In this work a convolutional neural network is applied for classification of emotional speech. Two significantly different approaches to speech signal pre-processing are compared: traditional, based on frequency spectrum and time domain-based. In the first case, a mel-scale spectrogram of the sound signal is computed and used as a 2-dimensional inp...

Background Current methods of cognitive interventions for older adults are increasingly employing modern technologies. However, research into possible applications of virtual reality (VR) in such interventions has begun only recently. The aim of the study was to evaluate the efficacy of VR-based cognitive training for older adults and to compare th...

Purpose The purpose of this paper is to apply recurrent neural networks (RNNs) and more specifically long-short term memory (LSTM)-based ones for mental task classification in terms of BCI systems. The authors have introduced novel LSTM-based multichannel architecture model which proved to be highly promising in other fields, yet was not used for m...

A qualitative comparison of three, popular and most widely known numerical integration methods in terms of atmospheric single scattering calculations is presented. A comparison of Midpoint, Trapezoidal and Simpson’s Rules taking into account quality of a clear sky generated images is performed. Methods that compute the atmospheric scattering integr...

In this paper a convolutional neural network, CNN, is trained to perform mental task recognition on the basis of the EEG signal. We address the problem of EEG data representation and processing, comparing two different approaches to the construction of the convolutional layers of the CNN. We demonstrate that splitting the input EEG data into indivi...

This paper presents a new 3D model of the skeletal gastrocnemius muscle. The model was created by combining the muscle fiber representation as a B-spline solid with a continual mechanochemical Usik’s model, which, due to its assumptions, accounts for thermomechanochemical changes in the muscle. The use of Usik’s model in the context of 3D modeling...

The "Computer Game Innovations" series is an international forum made to enable exchange of knowledge and expertise in the field of video games development. Comprising both academic research and industrial needs, the series aims at advancing innovative industry-academia collaboration. The monograph provides a unique set of articles presenting origi...

Mental tasks classification is increasingly recognized as a major challenge in the field of EEG signal processing and analysis. State-of-the-art approaches face the issue of spatially unstable structure of highly noised EEG signals. To address this problem, this paper presents a multi-channel convolutional neural network architecture with adaptivel...

Though reference image quality can be calculated with several, well established, comparison methods, images synthesizing light atmospheric scattering phenomenon require adequate evaluation approaches. Current metrics concentrate mainly on noise ratio, entropy or simple pixels correlation coefficients. Thus methods require images strict adequacy in...

This paper presents improved weighted measures for a point cloud segmentation quality evaluation. They provide more reliable and intuitive appraisal as well as more representative classification characteristics. The new measures are compared with the existing ones: based on classification, and based on information theory. The experiments and measur...

In this paper we present the enhancement of the standard two-view reconstruction procedure. An ordinary approach assumes determination of points’ correspondences followed by projection matrix estimation, to finally refine results with bundle adjustment taking as a cost function reprojection error. Our contribution is realized in two manners: introduc...

One of the key technologies that lays behind the human–machine interaction and human motion diagnosis is the limbs motion tracking. To make the limbs tracking efficient, it must be able to estimate a precise and unambiguous position of each tracked human joint and resulting body part pose. In recent years, body pose estimation became very popular a...

In the era of aging societies, research into methods of cognitive rehabilitation in clinical populations and cognitive enhancement in healthy older adults has soared recently. The growing interest in this area has stimulated the development of technologically advanced computerized training, and solutions based on virtual reality (VR) are emerging....

Face emotions analysis is one of the fundamental techniques that might be exploited in a natural human-computer interaction process and thus is, one of the most studied topics in current computer vision literature. In consequence face features extraction is an indispensable element of the face emotion analysis as it influences decision making perfo...

BCI mental tasks (hands movements and words imagination) classification becomes a challenging task of EEG signal processing and analysis. State-of-art approaches bother with spatial, unstable structure of highly noised EEG signals. Presented approach not only provides spatially dedicated convolutional neural network (CNN) architecture but also adap...

The "Computer Game Innovations" series is an international forum designed to enable the exchange of knowledge and expertise in the field of video game development. Comprising both academic research and industrial needs, the series aims at advancing innovative industry-academia collaboration. The monograph provides a unique set of articles presentin...

Brain computer interfaces become more and more available, mainly due to cheaper and better technology. Some of the devices, like NeuroSky MindWave and Emotiv EPOC became an example of the affordable apparatus that may be exploited for game interaction. At the same time most of authors, exploring brain waves interactions paradigms in games, concentr...

Nowadays, skinning of deformable meshes in real-time applications is widely used. However, the method that these applications use (Linear Blend Skinning) requires sometimes artists intervention to remove some artefacts. In this paper we describe and compare this old-fashioned method with a method called Dual Quaternion Linear Blend Skinning (DQLBS)...

Gender recognition, across different races and regardless of age, is becoming an increasingly important technology in the domains of marketing, human-computer interaction and security. Most state-of-the-art systems consider either highly constrained conditions or relatively large databases. In either case, often not enough attention is paid to cros...

Nowadays, people expectations about high realism in games are very high and computers have to make a huge effort to compute every simple detail that occurs in a virtual 3D scene. Fortunately, we can use power of Graphics Processing Units (GPU) to compute some part of the most computationally heavy algorithms. In this paper, we present method to acc...

In recent years there has been an intensive development of human computer interaction systems. Today's computer systems are able not only to track the user's face and gather static information, but also actively respond to him. The face detection allows to identify and determine user sex, age, mimic and others. Those techniques are popular in marke...

Microsoft Kinect v.1 and inertial measurement units (IMU) became very popular and broadly available depth and inertia estimating devices, which allow home users to detect and track human limbs motion. Due to their working characteristics both of these devices are sufficient for casual scenarios, where precision is not a crucial factor. In the follo...

Face emotions analysis is one of the fundamental techniques that might be exploited in a natural human-computer interaction process and thus is one of the most studied topics in current computer vision literature. In consequence face features extraction is an indispensable element of the face emotion analysis as it influences decision making perform...

Stereoscopic films and interactive presentations are extensively popularized whereas their perceived quality still dissatisfies viewers. The reasons are shared between hardware inconsistencies and stereo image producers unawareness concerning factors influencing depth perception quality. This paper reviews aspects influencing 3D image perception vi...

Precise and unambiguous limbs motion tracking is one of the key aspects laying behind natural human-machine communication. The paper presents a novel approach to depth sensor (Microsoft Kinect) and inertial measurement units (IMU) data fusion, providing more precise and stable hand joints tracking. The new method substitutes, mainly described in li...

Medical rehabilitation treatment is of vital importance to all those who have experienced limb impairments due to unexpected accidents or geriatric dysfunctions. However, due to extensive government savings, the access to regular rehabilitation services is becoming increasingly difficult. This paper presents a low-cost, immersive augmented reality...

Eye-gaze tracking is an aspect of human-computer interaction still growing in popularity,. Tracking human gaze point can help control user interfaces and may help evaluate graphical user interfaces. At the same time professional eye-trackers are very expensive and thus unavailable for most of user interface researchers and small companies. The pape...

Stereoscopic films and interactive presentations are extensively popularized whereas their perceived quality still dissatisfies viewers. The reasons are shared between hardware inconsistencies and stereo image producers unawareness concerning factors influencing depth perception quality. This paper reviews aspects influencing 3D image perception vi...

Gaze tracking is an aspect of human-computer interaction still growing in popularity. Tracking human eye fixation points can help control user interfaces and eventually may help in the interface evaluation or optimization. Unfortunately professional eye-trackers are very expensive and thus hardly available for researchers and small companies. The p...

Artificial camera navigation is the most ubiquitous and principal interaction task within a virtual environment. Efficient and intuitive virtual scene navigation affects other tasks completion performance. Though many scientists have elaborated invaluable navigation techniques design guidelines, it is still, especially for novice users, the really...