Popular Ensemble Methods: An Empirical Study

An ensemble consists of a set of individually trained classifiers (such as neural networks or decision trees) whose predictions are combined when classifying novel instances. Previous research has shown that an ensemble is often more accurate than any of the single classifiers in the ensemble. Bagging (Breiman, 1996c) and Boosting (Freund and Shapire, 1996; Shapire, 1990) are two relatively new but popular methods for producing ensembles. In this paper we evaluate these methods on 23 data sets using both neural networks and decision trees as our classification algorithm. Our results clearly indicate a number of conclusions. First, while Bagging is almost always more accurate than a single classifier, it is sometimes much less accurate than Boosting. On the other hand, Boosting can create ensembles that are less accurate than a single classifier -- especially when using neural networks. Analysis indicates that the performance of the Boosting methods is dependent on the characteristics of the data set being examined. In fact, further results show that Boosting ensembles may overfit noisy data sets, thus decreasing its performance. Finally, consistent with previous studies, our work suggests that most of the gain in an ensemble's performance comes in the first few classifiers combined; however, relatively large gains can be seen up to 25 classifiers when Boosting decision trees

Fitness v. Physique: Is Body Image Harming Our Health?

Purpose: Determine how important health and fitness is to college aged individuals and whether they valued body image or personal fitness higher

A dynamic systems engineering methodology research study. Phase 2: Evaluating methodologies, tools, and techniques for applicability to NASA's systems projects

A study of NASA's Systems Management Policy (SMP) concluded that the primary methodology being used by the Mission Operations and Data Systems Directorate and its subordinate, the Networks Division, is very effective. Still some unmet needs were identified. This study involved evaluating methodologies, tools, and techniques with the potential for resolving the previously identified deficiencies. Six preselected methodologies being used by other organizations with similar development problems were studied. The study revealed a wide range of significant differences in structure. Each system had some strengths but none will satisfy all of the needs of the Networks Division. Areas for improvement of the methodology being used by the Networks Division are listed with recommendations for specific action

Brief of Scholars of the History and Original Meaning of the Fourth Amendment as Amici Curiae in Support of Petitioner, Carpenter v. United States, No. 16-402 (U.S. Aug. 14, 2017)

Obtaining and examining cell site location records to find a person is a “search” in any normal sense of the word — a search of documents and a search for a person and her personal effects. It is therefore a “search” within the meaning of the Fourth Amendment in that it constitutes “examining,” “exploring,” “looking through,” “inquiring,” “seeking,” or “trying to find.” Nothing about the text of the Fourth Amendment, or the historical backdrop against which it was adopted, suggests that “search” should be construed more narrowly as, for example, intrusions upon subjectively manifested expectations of privacy that society is prepared to recognize as reasonable.Entrusting government agents with unfettered discretion to conduct searches using cell site location information undermines Fourth Amendment rights. The Amendment guarantees “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches.” The Framers chose that language deliberately. It reflected the insecurity they suffered at the hands of “writs of assistance,” a form of general warrant that granted state agents broad discretion to search wherever they pleased. Such arbitrary power was “unreasonable” to the Framers, being “against the reason of the common law,” and it was intolerable because of its oppressive impact on “the people” as a whole. As emphasized in one of the seminal English cases that inspired the Amendment, this kind of general power to search was “totally subversive of the liberty of the subject.” James Otis’s famous speech denouncing a colonial writ of assistance similarly condemned those writs as “the worst instrument of arbitrary power,” placing “the liberty of every man in the hands of every petty officer.” Thus, although those who drafted and ratified the Fourth Amendment could not have anticipated cellphone technology, they would have recognized the dangers inherent in any state claim of unlimited authority to conduct searches for evidence of criminal activity. Cell site location information provides insight into where we go and what we do. Because this information is constantly generated and can be retrieved by the government long after the activities it memorializes have taken place, unfettered government access to cell site location information raises the specter of general searches and undermines the security of “the people.

Is Obtaining an Arrestee\u27s DNA a Valid Special Needs Search Under the Fourth Amendment? What Should (and Will) the Supreme Court Do?

An increasing number of states are enacting laws authorizing the forcible taking and analysis of DNA from certain categories of arrestees. For example, California\u27s Proposition 69 requires state law enforcement officials to obtain DNA samples from certain arrestees. By 2009, Proposition 69 will require a DNA sample from every adult arrested for or charged with a felony. This article addresses the constitutionality, under the Fourth Amendment, of taking DNA samples from persons subject to arrest. In particular, the article focuses on the statutes of Virginia and Louisiana, which have authorized DNA sampling of persons arrested for violent crimes and sex offenses, and examines whether these laws are consistent with the Fourth Amendment\u27s special needs doctrine as outlined by several Supreme Court rulings. The thesis of the article is that forcibly obtaining DNA from an arrestee violates the Fourth Amendment. There is little doubt these intrusions are searches under the Fourth Amendment. Moreover, I argue that this type of search cannot be upheld under the Supreme Court\u27s special needs cases because obtaining a DNA sample is directly designed to promote the state\u27s interest in solving crimes

A Criminal Procedure Regime Based on Instrumental Values: A Review of \u27About Guilt and Innocence: The Origins, Development, and Future of Constitutional Criminal Procedure,\u27 by Donald A. Dripps (Prager Publishers, 2003)

Like many legal academics, Professor Donald Dripps believes that the Supreme Court\u27s criminal procedure doctrine is a mess. Dripps believes that the Court\u27s doctrine is in large measure responsible for the failure of the criminal-procedure revolution and contends that current doctrine does not reflect prevailing (and justified) values about criminal process. To prove his claim, Dripps has written a book that expertly identifies the flaws, inconsistencies and missteps of the Court\u27s constitutional criminal procedure cases dating back to the adoption of the Fourteenth Amendment. About Guilt and Innocence: The Origins, Development, and Future of Constitutional Criminal Procedure is a comprehensive and thoughtful critique of the Court\u27s criminal procedure jurisprudence. The book primarily focuses on the Court\u27s Fourth, Fifth and Sixth Amendment cases. My review of Dripps\u27 book proceeds in two parts. Part I provides a general overview of the book and highlights Dripps\u27 core arguments. Generally speaking, Dripps asserts that the Court\u27s criminal procedure cases should focus on instrumental concerns, such as proportionate police investigative practices and reliable adjudicatory procedures. Part II of my review discusses Dripps\u27 analysis of the Court\u27s confession cases. This part includes a description of Dripps\u27 proposal to regulate police interrogation under an instrumental regime and my critique of his proposal