26 research outputs found
Shape analysis of the corpus callosum of autistic and normal subjects in neuroimaging.
Early detection of human disease in todayâs society can have an enormous impact on the severity of the disease that is manifested. Disease such as Autism and Dyslexia, which have no current cure or proven mechanism as to how they develop, can often have an adverse physical and physiological impact on the lifestyle of a human being. Although these disease are not fully curable, the severity handicaps that accompany them can be significantly reduced with the proper therapy, and thus the earlier that the disease is detected the faster therapy can be administered. The research in this thesis is an attempt at studying discriminatory shape measures of some brain structures that are known to carry changes from autistics to normal individuals. The focus will be on the corpus callosum. There has been considerable research done on the brain scans (MRI, CT) of autistic individuals vs. control (normal) individuals to observe any noticeable discrepancies through statistical analysis. The most common and powerful tool to analyze structures of the brain, once a specific region has been segmented, is using Registration to match like structures and record their error. The ICP algorithm (Iterative Closest Point) is commonly used to accomplish this task. Many techniques such as level sets and statistical methods can be used for segmentation. The Corpus Callosum (CC) and the cortical surface of the brain are currently where most Autism analysis is performed. It has been observed that the gyrification of the cortical surface is different in the two groups, and size as well as shape of the CC. An analysis approach for autism MRI is quite extensive and involves many steps. This thesis is limited to examination of shape measures of the CC that lend discrimination ability to distinguish between normal and autistic individuals from T1-weigheted MRI scans. We will examine two approaches for shape analysis, based on the traditional Fourier Descriptors (FD) method and shape registration (SR) using the procrustes technique. MRI scans of 22 autistic and 16 normal individuals are used to test the approaches developed in this thesis. We show that both FD and SR may be used to extract features to discriminate between the two populations with accuracy levels over 80% up to 100% depending on the technique
The Impact Of The Development Of ICT In Several Hungarian Economic Sectors
As the author could not find a reassuring mathematical and
statistical method in the literature for studying the effect of
information communication technology on enterprises, the author
suggested a new research and analysis method that he also used to study the Hungarian economic sectors. The question of what
factors have an effect on their net income is vital for enterprises. At first, the author studied some potential indicators related to economic sectors, then those indicators were compared to the net income of the surveyed enterprises. The resulting data showed that the growing penetration of electronic marketplaces contributed to the change of the net income of enterprises to the greatest extent.
Furthermore, among all the potential indicators, it was the only indicator directly influencing the net income of enterprises.
With the help of the compound indicator and the financial data
of the studied economic sectors, the author made an attempt to find a connection between the development level of ICT and
profitability. Profitability and productivity are influenced by a lot of other factors as well. As the effect of the other factors could not be measured, the results â shown in a coordinate system - are not full but informative.
The highest increment of specific Gross Value Added was
produced by the fields of âManufacturingâ, âElectricity, gas and water supplyâ, âTransport, storage and communicationâ and
âFinancial intermediationâ. With the exception of âElectricity, gas and water supplyâ, the other economic sectors belong to the group of underdeveloped branches (below 50 percent).
On the other hand, âConstructionâ, âHealth and social workâ and
âHotels and restaurantsâ can be seen as laggards, so they got into the lower left part of the coordinate system.
âAgriculture, hunting and forestryâ can also be classified as a
laggard economic sector, but as the effect of the compound
indicator on the increment of Gross Value Added was less
significant, it can be found in the upper left part of the coordinate system. Drawing a trend line on the points, it can be made clear that it shows a positive gradient, that is, the higher the usage of ICT devices, the higher improvement can be detected in the specific Gross Value Added
Engineering Education and Research Using MATLAB
MATLAB is a software package used primarily in the field of engineering for signal processing, numerical data analysis, modeling, programming, simulation, and computer graphic visualization. In the last few years, it has become widely accepted as an efficient tool, and, therefore, its use has significantly increased in scientific communities and academic institutions. This book consists of 20 chapters presenting research works using MATLAB tools. Chapters include techniques for programming and developing Graphical User Interfaces (GUIs), dynamic systems, electric machines, signal and image processing, power electronics, mixed signal circuits, genetic programming, digital watermarking, control systems, time-series regression modeling, and artificial neural networks
An Overview of Backdoor Attacks Against Deep Neural Networks and Possible Defences
Together with impressive advances touching every aspect of our society, AI technology based on Deep Neural Networks (DNN) is bringing increasing security concerns. While attacks operating at test time have monopolised the initial attention of researchers, backdoor attacks, exploiting the possibility of corrupting DNN models by interfering with the training process, represent a further serious threat undermining the dependability of AI techniques. In backdoor attacks, the attacker corrupts the training data to induce an erroneous behaviour at test time. Test-time errors, however, are activated only in the presence of a triggering event. In this way, the corrupted network continues to work as expected for regular inputs, and the malicious behaviour occurs only when the attacker decides to activate the backdoor hidden within the network. Recently, backdoor attacks have been an intense research domain focusing on both the development of new classes of attacks, and the proposal of possible countermeasures. The goal of this overview is to review the works published until now, classifying the different types of attacks and defences proposed so far. The classification guiding the analysis is based on the amount of control that the attacker has on the training process, and the capability of the defender to verify the integrity of the data used for training, and to monitor the operations of the DNN at training and test time. Hence, the proposed analysis is suited to highlight the strengths and weaknesses of both attacks and defences with reference to the application scenarios they are operating in
An Overview of Backdoor Attacks Against Deep Neural Networks and Possible Defences
Together with impressive advances touching every aspect of our society, AI technology based on Deep Neural Networks (DNN) is bringing increasing security concerns. While attacks operating at test time have monopolised the initial attention of researchers, backdoor attacks, exploiting the possibility of corrupting DNN models by interfering with the training process, represent a further serious threat undermining the dependability of AI techniques. In backdoor attacks, the attacker corrupts the training data to induce an erroneous behaviour at test time. Test-time errors, however, are activated only in the presence of a triggering event. In this way, the corrupted network continues to work as expected for regular inputs, and the malicious behaviour occurs only when the attacker decides to activate the backdoor hidden within the network. Recently, backdoor attacks have been an intense research domain focusing on both the development of new classes of attacks, and the proposal of possible countermeasures. The goal of this overview is to review the works published until now, classifying the different types of attacks and defences proposed so far. The classification guiding the analysis is based on the amount of control that the attacker has on the training process, and the capability of the defender to verify the integrity of the data used for training, and to monitor the operations of the DNN at training and test time. Hence, the proposed analysis is suited to highlight the strengths and weaknesses of both attacks and defences with reference to the application scenarios they are operating in
Backdoor Attacks and Defences on Deep Neural Networks
Nowadays, due to the huge amount of resources required for network training, pre-trained models are commonly exploited in all kinds of deep learning tasks, like image classification, natural language processing, etc. These models are directly deployed in the real environments, or only fine-tuned on a limited set of data that are collected, for instance, from the Internet. However, a natural question arises: can we trust pre-trained models or the data downloaded from the Internet? The answer is âNoâ. An attacker can easily perform a so-called backdoor attack to hide a backdoor into a pre-trained model by poisoning the dataset used for training or indirectly releasing some poisoned data on the Internet as a bait. Such an attack is stealthy since the hidden backdoor does not affect the behaviour of the network in normal operating conditions, and the malicious behaviour being activated only when a triggering signal is presented at the network input.
In this thesis, we present a general framework for backdoor attacks and defences, and overview the state-of-the-art backdoor attacks and the corresponding defences in the field image classification, by casting them in the introduced framework. By focusing on the face recognition domain, two new backdoor attacks were proposed, effective under different threat models. Finally, we design a universal method to defend against backdoor attacks, regardless of the specific attack setting, namely the poisoning strategy and the triggering signal
Framework for Automatic Identification of Paper Watermarks with Chain Codes
Title from PDF of title page viewed May 21, 2018Dissertation advisor: Reza DerakhshaniVitaIncludes bibliographical references (pages 220-235)Thesis (Ph.D.)--School of Computing and Engineering. University of Missouri--Kansas City, 2017In this dissertation, I present a new framework for automated description, archiving, and
identification of paper watermarks found in historical documents and manuscripts. The early
manufacturers of paper have introduced the embedding of identifying marks and patterns as a sign
of a distinct origin and perhaps as a signature of quality. Thousands of watermarks have been
studied, classified, and archived. Most of the classification categories are based on image similarity
and are searchable based on a set of defined contextual descriptors. The novel method presented
here is for automatic classification, identification (matching) and retrieval of watermark images
based on chain code descriptors (CC). The approach for generation of unique CC includes a novel
image preprocessing method to provide a solution for rotation and scale invariant representation
of watermarks. The unique codes are truly reversible, providing high ratio lossless compression,
fast searching, and image matching. The development of a novel distance measure for CC
comparison is also presented. Examples for the complete process are given using the recently
acquired watermarks digitized with hyper-spectral imaging of Summa Theologica, the work of
Antonino Pierozzi (1389 â 1459). The performance of the algorithm on large datasets is
demonstrated using watermarks datasets from well-known library catalogue collections.Introduction -- Paper and paper watermarks -- Automatic identification of paper watermarks -- Rotation, Scale and translation invariant chain code -- Comparison of RST_Invariant chain code -- Automatic identification of watermarks with chain codes -- Watermark composite feature vector -- Summary -- Appendix A. Watermarks from the Bernstein Collection used in this study -- Appendix B. The original and transformed images of watermarks -- Appendix C. The transformed and scaled images of watermarks -- Appendix D. Example of chain cod
Dagstuhl News January - December 1999
"Dagstuhl News" is a publication edited especially for the members of the Foundation "Informatikzentrum Schloss Dagstuhl" to thank them for their support. The News give a summary of the scientific work being done in Dagstuhl. Each Dagstuhl Seminar is presented by a small abstract describing the contents and scientific highlights of the seminar as well as the perspectives or challenges of the research topic