Feature Selection Using Different Mutual Information Estimation Methods

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2010Bu çalışmada, farklı karşılıklı bilgi kestirim yöntemlerinin öznitelik seçimi üzerindeki etkisi incelenmiş, minimum-bolluk-maksimum-ilgi (mRMR) ve karşılıklı bilgi filtresi öznitelik seçim yöntemleri, bölümlemeden daha gelişmiş kestirim yöntemleri olan çekirdek yoğunluk kestirimi (KDE) bazlı ve k en yakın komşu (KNN) bazlı yöntemler kullanılarak iyileştirilmeye çalışılmıştır. Ayrıca bu karşılıklı bilgi kestirim yöntemlerinin yapay ve gerçek veriler üzerindeki başarımı ölçülmüş ve yöntemlerin başarımı altküme seçimi ve birleştirme yolları ile arttırılmaya çalışılmıştır. Altküme seçimi ve birleştirme yöntemlerinin başarımı arttırmadığı, k en yakın komşu bazlı kestirim yönteminin karşılıklı bilgi filtresi için kullanıldığında bölümlemeden daha yüksek başarım sağladığı, fakat mRMR’ın bundan yararlanamadığı görülmüştür.In this study, effect of different mutual information estimation methods on feature selection is examined, minimum-redundancy-maximum-relevance and mutual information filter feature selection methods are tried to be improved by using more advanced mutual information estimation methods than binning like k-nearest-neighbour (KNN) based and kernel density estimation (KDE) based methods. Besides, performances of these mutual information estimation methods on artificial and real data are measured and this performance is tried to be improved by subset selection and combination. It is concluded that subset selection and combination does not improve performance, KNN based estimation method improves performance when used in mutual information filter but mRMR does not benefit from this.Yüksek LisansM.Sc

Police Code of Silence in Times of Change

This book explores the contours of the code of silence and provides policy recommendations geared toward creating an environment less conducive for police misconduct. It responds to the recent calls for police reform, in the wake of the perceived illegitimacy of police actions and the protection that the code of silence seems to provide to the police officers who violate the official rules. Using a case study of a medium-sized U.S. police agency, this book employs the lens of police integrity theory to provide empirically grounded explanations of the code of silence. It examines the potential effects of organizational factors and the attitudes of individual police officers on their willingness to adhere to the code of silence in cases of police corruption, the use of excessive force, interpersonal deviance, and organizational deviance. The book focuses on the following factors that could influence the police code of silence in the times of change: The impact of organizational rule dissemination, discipline, and disciplinary fairness on the scope of the code of silence The role organizational justice plays in shaping police officer willingness to report misconduct The effect that police officers’ self-legitimacy has on their decisions to adhere to the code The influence of peer culture on individual police officer amenability to maintain the code The relationship between officers’ views of themselves, the organization, and the community on their willingness to report misconduc

Police Code of Silence in Times of Change

This book explores the contours of the code of silence and provides policy recommendations geared toward creating an environment less conducive for police misconduct. It responds to the recent calls for police reform, in the wake of the perceived illegitimacy of police actions and the protection that the code of silence seems to provide to the police officers who violate the official rules. Using a case study of a medium-sized U.S. police agency, this book employs the lens of police integrity theory to provide empirically grounded explanations of the code of silence. It examines the potential effects of organizational factors and the attitudes of individual police officers on their willingness to adhere to the code of silence in cases of police corruption, the use of excessive force, interpersonal deviance, and organizational deviance. The book focuses on the following factors that could influence the police code of silence in the times of change: The impact of organizational rule dissemination, discipline, and disciplinary fairness on the scope of the code of silence The role organizational justice plays in shaping police officer willingness to report misconduct The effect that police officers’ self-legitimacy has on their decisions to adhere to the code The influence of peer culture on individual police officer amenability to maintain the code The relationship between officers’ views of themselves, the organization, and the community on their willingness to report misconduc

The Causes and Consequences of Albanian Emigration during Transition: Evidence from Micro Data

This note reports the results of field surveys of individuals and firms in Albania, carried out during 1998. The surveys were designed to analyse the extent of emigration from Albania during the 1990s and its causes and consequences. Our results show that emigrants are motivated mainly by the ease of access to neighbouring countries and by the prospect of high financial returns. Although most emigrants worked illegally and had part-time, low-skilled jobs, the majority found the overall experience positive, and the skills and earnings they acquired abroad have contributed to establishing businesses upon their return. These results have important policy implications for both EU countries and other transition countries in the region.Emigration; Albania