Mixtures of Boosted Classifiers for Frontal Face Detection

This paper describes a new approach to automatic frontal face detection which employs Gaussian filters as local image descriptors. We then show how the paradigm of classifier combination can be used for building a face detector that outperforms the current state--of--the--art systems, while remaining fast enough for being used in real--time systems. It is based on the combination of several parallel classifiers trained on subsets of the complete training set. We report a number of results on some reference datasets and we use an unbiased method for comparing the detectors

A Comprehensive Survey on Enterprise Financial Risk Analysis: Problems, Methods, Spotlights and Applications

Enterprise financial risk analysis aims at predicting the enterprises' future financial risk.Due to the wide application, enterprise financial risk analysis has always been a core research issue in finance. Although there are already some valuable and impressive surveys on risk management, these surveys introduce approaches in a relatively isolated way and lack the recent advances in enterprise financial risk analysis. Due to the rapid expansion of the enterprise financial risk analysis, especially from the computer science and big data perspective, it is both necessary and challenging to comprehensively review the relevant studies. This survey attempts to connect and systematize the existing enterprise financial risk researches, as well as to summarize and interpret the mechanisms and the strategies of enterprise financial risk analysis in a comprehensive way, which may help readers have a better understanding of the current research status and ideas. This paper provides a systematic literature review of over 300 articles published on enterprise risk analysis modelling over a 50-year period, 1968 to 2022. We first introduce the formal definition of enterprise risk as well as the related concepts. Then, we categorized the representative works in terms of risk type and summarized the three aspects of risk analysis. Finally, we compared the analysis methods used to model the enterprise financial risk. Our goal is to clarify current cutting-edge research and its possible future directions to model enterprise risk, aiming to fully understand the mechanisms of enterprise risk communication and influence and its application on corporate governance, financial institution and government regulation

Nearest Neighbor Discriminant Analysis Based Face Recognition Using Ensembled Gabor Features

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Bilişim Enstitüsü, 2009Thesis (M.Sc.) -- İstanbul Technical University, Institute of Informatics, 2009Son yıllarda, ışık varyasyonlarına ve yüz ifade değişikliklerine karşı gürbüz olduğu üzere yüz tanıma alanında Gabor öznitelikleri tabanlı yüz temsil etme çok umut vaad edici sonuç vermiştir. Seçilen uzamsal frekans, uzamsal lokalizasyon ve yönelime göre yerel yapıyı hesaplaması, elle işaretlendirmeye ihtiyaç duymaması Gabor özniteliklerini efektif yapan özellikleridir. Bu tez çalışmasındaki katkı, Gabor süzgeçleri ve En Yakın Komşu Ayrışım Analizi'nin (EYKAA) güçlerini birleştirerek önemli ayrışım öznitelikleri ortaya çıkaran Gabor En Yakın Komşu Sınıflandırıcısı (GEYKS) genişletip Parçalı Gabor En Yakın Komşu Sınıflandırıcısı (PGEYKS) metodunu ortaya koymaktır. PGEYKS; alçaltılmış gabor öznitelikleri barındıran farklı segmanları kullanarak, her biri ayrı dizayn edilen birçok EYKAA tabanlı bileşen sınıflandırıcılarını bir araya getiren grup sınıflandırıcısıdır. Tüm gabor özniteliklerinin alçaltılmış boyutu tek bir EYKAA bileşeninden çıkarıldığı gibi, PGEYKS; ayrışım bilgi kaybını minimum yapıp 3S (yetersiz örnek miktarı) problemini önleyerek alçaltılmış gabor öznitelikleri içindeki ayrıştırabilirliği daha iyi kullanır. PGEYKS yönteminin tanıma başarımı karşılaştırmalı performans çalışması ile gösterilmiştir. Farklı ışıklandırma ve yüz ifadesi deişiklikleri barındıran 200 sınıflık FERET veritabanı alt kümesinde, 65 öznitelik için PGEYKS %100 başarım elde ederek atası olan GEYKS'nın aldığı %98 başarısını ve diğer GFS (Gabor Fisher Sınıflandırıcı) ve GTS (Gabor Temel Sınıflandırıcı) gibi standard methodlardan daha iyi sonuçlar vermiştir. Ayrıca YALE veritabanı üzerindeki testlerde PGEYKS her türlü (k, alpha) çiftleri için GEYKS'ten daha başarılıdır ve 14 öznitelik için step size = 5, k = 5, alpha = 3 parametlerinde %96 tanıma başarısına ulaşmıştır.In last decades, Gabor features based face representation performed very promising results in face recognition area as its robust to variations due to illumination and facial expression changes. The properties of Gabor are, which makes it effective, it computes the local structure corresponding to spatial frequency (scale), spatial localization, and orientation selectivity and no need for manual annotations. The contribution of this thesis, an Ensemble based Gabor Nearest Neighbor Classifier (EGNNC) method is proposed extending Gabor Nearest Neighbor Classifier (GNNC) where GNNC extracts important discriminant features both utilizing the power of Gabor filters and Nearest Neighbor Discriminant Analysis (NNDA). EGNNC is an ensemble classifier combining multiple NNDA based component classifiers designed respectively using different segments of the reduced Gabor feature. Since reduced dimension of the entire Gabor feature is extracted by one component NNDA classifier, EGNNC has better use of the discriminability implied in reduced Gabor features by the avoiding 3S (small sample size) problem as making minimum loss of discriminative information. The accuracy of the EGNNC is shown by comparative performance work. Using a 200 class subset of FERET database covering illumination and expression variations, EGNNC achieved 100% recognition rate, outperforming its ancestor GNNC perform 98 percent as well as standard methods such GFC and GPC for 65 features. Also for the YALE database, EGNNC outperformed GNNC on all (k, alpha) tuples and EGNNC reaches 96 percent accuracy in 14 feature dimension, along with parameters step size = 5, k = 5, alpha = 3.Yüksek LisansM.Sc

A Comprehensive Survey of Data Mining-based Fraud Detection Research

This survey paper categorises, compares, and summarises from almost all published technical and review articles in automated fraud detection within the last 10 years. It defines the professional fraudster, formalises the main types and subtypes of known fraud, and presents the nature of data evidence collected within affected industries. Within the business context of mining the data to achieve higher cost savings, this research presents methods and techniques together with their problems. Compared to all related reviews on fraud detection, this survey covers much more technical articles and is the only one, to the best of our knowledge, which proposes alternative data and solutions from related domains.Comment: 14 page

Human face detection techniques: A comprehensive review and future research directions

Face detection which is an effortless task for humans are complex to perform on machines. Recent veer proliferation of computational resources are paving the way for a frantic advancement of face detection technology. Many astutely developed algorithms have been proposed to detect faces. However, there is a little heed paid in making a comprehensive survey of the available algorithms. This paper aims at providing fourfold discussions on face detection algorithms. At first, we explore a wide variety of available face detection algorithms in five steps including history, working procedure, advantages, limitations, and use in other fields alongside face detection. Secondly, we include a comparative evaluation among different algorithms in each single method. Thirdly, we provide detailed comparisons among the algorithms epitomized to have an all inclusive outlook. Lastly, we conclude this study with several promising research directions to pursue. Earlier survey papers on face detection algorithms are limited to just technical details and popularly used algorithms. In our study, however, we cover detailed technical explanations of face detection algorithms and various recent sub-branches of neural network. We present detailed comparisons among the algorithms in all-inclusive and also under sub-branches. We provide strengths and limitations of these algorithms and a novel literature survey including their use besides face detection

Personality extraction through LinkedIn

L'extraction de personnalité sur les réseaux sociaux est un domaine qui n'a que récemment commencé à capturer l'attention des chercheurs. La tâche consiste à, en partant d'un corpus de profils d'utilisateurs de réseaux sociaux, être capable de classifier leur personnalité correctement, selon un modèle de personnalité tel que défini en psychologie. Ce mémoire apporte trois innovations au domaine. Premièrement, la collecte d'un corpus d'utilisateurs LinkedIn. Deuxièmement, l'extraction sur deux modèles de personnalités, MBTI et DiSC, l'extraction sur DiSC n'ayant pas encore été faite dans le domaine, et finalement, la possibilité de passer d'un modèle de personnalité à l'autre est explorée, dans l'idée qu'il serait ainsi possible d'obtenir les résultats de multiples modèles de personnalités en partant d'un seul test.Personality extraction through social networks is a field that only recently started to capture the attention of researchers. The task consists in, starting with a corpus of user profiles on a particular social network, classifying their personalities correctly, according to a specific personality model as described in psychology. In this master thesis, three innovations to the domain are presented. Firstly, the collection of a corpus of LinkedIn users. Secondly, the extraction of the personality according to two personality models, DiSC and MBTI, the extraction with DiSC having never been done before. Lastly, the idea of going from one personality model to the other is explored, thus creating the possibility of having the results on two personality models with only one personality test

Machine learning approaches for lung cancer diagnosis.

The enormity of changes and development in the field of medical imaging technology is hard to fathom, as it does not just represent the technique and process of constructing visual representations of the body from inside for medical analysis and to reveal the internal structure of different organs under the skin, but also it provides a noninvasive way for diagnosis of various disease and suggest an efficient ways to treat them. While data surrounding all of our lives are stored and collected to be ready for analysis by data scientists, medical images are considered a rich source that could provide us with a huge amount of data, that could not be read easily by physicians and radiologists, with valuable information that could be used in smart ways to discover new knowledge from these vast quantities of data. Therefore, the design of computer-aided diagnostic (CAD) system, that can be approved for use in clinical practice that aid radiologists in diagnosis and detecting potential abnormalities, is of a great importance. This dissertation deals with the development of a CAD system for lung cancer diagnosis, which is the second most common cancer in men after prostate cancer and in women after breast cancer. Moreover, lung cancer is considered the leading cause of cancer death among both genders in USA. Recently, the number of lung cancer patients has increased dramatically worldwide and its early detection doubles a patient’s chance of survival. Histological examination through biopsies is considered the gold standard for final diagnosis of pulmonary nodules. Even though resection of pulmonary nodules is the ideal and most reliable way for diagnosis, there is still a lot of different methods often used just to eliminate the risks associated with the surgical procedure. Lung nodules are approximately spherical regions of primarily high density tissue that are visible in computed tomography (CT) images of the lung. A pulmonary nodule is the first indication to start diagnosing lung cancer. Lung nodules can be benign (normal subjects) or malignant (cancerous subjects). Large (generally defined as greater than 2 cm in diameter) malignant nodules can be easily detected with traditional CT scanning techniques. However, the diagnostic options for small indeterminate nodules are limited due to problems associated with accessing small tumors. Therefore, additional diagnostic and imaging techniques which depends on the nodules’ shape and appearance are needed. The ultimate goal of this dissertation is to develop a fast noninvasive diagnostic system that can enhance the accuracy measures of early lung cancer diagnosis based on the well-known hypotheses that malignant nodules have different shape and appearance than benign nodules, because of the high growth rate of the malignant nodules. The proposed methodologies introduces new shape and appearance features which can distinguish between benign and malignant nodules. To achieve this goal a CAD system is implemented and validated using different datasets. This CAD system uses two different types of features integrated together to be able to give a full description to the pulmonary nodule. These two types are appearance features and shape features. For the appearance features different texture appearance descriptors are developed, namely the 3D histogram of oriented gradient, 3D spherical sector isosurface histogram of oriented gradient, 3D adjusted local binary pattern, 3D resolved ambiguity local binary pattern, multi-view analytical local binary pattern, and Markov Gibbs random field. Each one of these descriptors gives a good description for the nodule texture and the level of its signal homogeneity which is a distinguishable feature between benign and malignant nodules. For the shape features multi-view peripheral sum curvature scale space, spherical harmonics expansions, and different group of fundamental geometric features are utilized to describe the nodule shape complexity. Finally, the fusion of different combinations of these features, which is based on two stages is introduced. The first stage generates a primary estimation for every descriptor. Followed by the second stage that consists of an autoencoder with a single layer augmented with a softmax classifier to provide us with the ultimate classification of the nodule. These different combinations of descriptors are combined into different frameworks that are evaluated using different datasets. The first dataset is the Lung Image Database Consortium which is a benchmark publicly available dataset for lung nodule detection and diagnosis. The second dataset is our local acquired computed tomography imaging data that has been collected from the University of Louisville hospital and the research protocol was approved by the Institutional Review Board at the University of Louisville (IRB number 10.0642). These frameworks accuracy was about 94%, which make the proposed frameworks demonstrate promise to be valuable tool for the detection of lung cancer