3,981 research outputs found

    A Benchmark for Image Retrieval using Distributed Systems over the Internet: BIRDS-I

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    The performance of CBIR algorithms is usually measured on an isolated workstation. In a real-world environment the algorithms would only constitute a minor component among the many interacting components. The Internet dramati-cally changes many of the usual assumptions about measuring CBIR performance. Any CBIR benchmark should be designed from a networked systems standpoint. These benchmarks typically introduce communication overhead because the real systems they model are distributed applications. We present our implementation of a client/server benchmark called BIRDS-I to measure image retrieval performance over the Internet. It has been designed with the trend toward the use of small personalized wireless systems in mind. Web-based CBIR implies the use of heteroge-neous image sets, imposing certain constraints on how the images are organized and the type of performance metrics applicable. BIRDS-I only requires controlled human intervention for the compilation of the image collection and none for the generation of ground truth in the measurement of retrieval accuracy. Benchmark image collections need to be evolved incrementally toward the storage of millions of images and that scaleup can only be achieved through the use of computer-aided compilation. Finally, our scoring metric introduces a tightly optimized image-ranking window.Comment: 24 pages, To appear in the Proc. SPIE Internet Imaging Conference 200

    The Hatsopoulos-Gyftopoulos resolution of the Schroedinger-Park paradox about the concept of "state" in quantum statistical mechanics

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    A seldom recognized fundamental difficulty undermines the concept of individual ``state'' in the present formulations of quantum statistical mechanics (and in its quantum information theory interpretation as well). The difficulty is an unavoidable consequence of an almost forgotten corollary proved by E. Schroedinger in 1936 and perused by J.L. Park, Am. J. Phys., Vol. 36, 211 (1968). To resolve it, we must either reject as unsound the concept of state, or else undertake a serious reformulation of quantum theory and the role of statistics. We restate the difficulty and discuss a possible resolution proposed in 1976 by G.N. Hatsopoulos and E.P. Gyftopoulos, Found. Phys., Vol. 6, 15, 127, 439, 561 (1976).Comment: RevTeX4, 7 pages, corrected a paragraph and added an example at page 3, to appear in Mod. Phys. Lett.

    Combustion and operating characteristics of spark-ignition engines

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    The spark-ignition engine turbulent flame propagation process was investigated. Then, using a spark-ignition engine cycle simulation and combustion model, the impact of turbocharging and heat transfer variations or engine power, efficiency, and NO sub x emissions was examined

    The Invisible Power of Fairness. How Machine Learning Shapes Democracy

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    Many machine learning systems make extensive use of large amounts of data regarding human behaviors. Several researchers have found various discriminatory practices related to the use of human-related machine learning systems, for example in the field of criminal justice, credit scoring and advertising. Fair machine learning is therefore emerging as a new field of study to mitigate biases that are inadvertently incorporated into algorithms. Data scientists and computer engineers are making various efforts to provide definitions of fairness. In this paper, we provide an overview of the most widespread definitions of fairness in the field of machine learning, arguing that the ideas highlighting each formalization are closely related to different ideas of justice and to different interpretations of democracy embedded in our culture. This work intends to analyze the definitions of fairness that have been proposed to date to interpret the underlying criteria and to relate them to different ideas of democracy

    Approximating Weighted Duo-Preservation in Comparative Genomics

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    Motivated by comparative genomics, Chen et al. [9] introduced the Maximum Duo-preservation String Mapping (MDSM) problem in which we are given two strings s1s_1 and s2s_2 from the same alphabet and the goal is to find a mapping π\pi between them so as to maximize the number of duos preserved. A duo is any two consecutive characters in a string and it is preserved in the mapping if its two consecutive characters in s1s_1 are mapped to same two consecutive characters in s2s_2. The MDSM problem is known to be NP-hard and there are approximation algorithms for this problem [3, 5, 13], but all of them consider only the "unweighted" version of the problem in the sense that a duo from s1s_1 is preserved by mapping to any same duo in s2s_2 regardless of their positions in the respective strings. However, it is well-desired in comparative genomics to find mappings that consider preserving duos that are "closer" to each other under some distance measure [19]. In this paper, we introduce a generalized version of the problem, called the Maximum-Weight Duo-preservation String Mapping (MWDSM) problem that captures both duos-preservation and duos-distance measures in the sense that mapping a duo from s1s_1 to each preserved duo in s2s_2 has a weight, indicating the "closeness" of the two duos. The objective of the MWDSM problem is to find a mapping so as to maximize the total weight of preserved duos. In this paper, we give a polynomial-time 6-approximation algorithm for this problem.Comment: Appeared in proceedings of the 23rd International Computing and Combinatorics Conference (COCOON 2017

    Use Of Molecular Epidemiology To Monitor The Nosocomial Dissemination Of Methicillin-resistant Staphylococcus Aureus In A University Hospital From 1991 To 2001.

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    Methicillin-resistant Staphylococcus aureus (MRSA) has been the cause of major outbreaks and epidemics among hospitalized patients, with high mortality and morbidity rates. We studied the genomic diversity of MRSA strains isolated from patients with nosocomial infection in a University Hospital from 1991 to 2001. The study consisted of two periods: period I, from 1991 to 1993 and period II from 1995 to 2001. DNA was typed by pulsed-field gel electrophoresis and the similarity among the MRSA strains was determined by cluster analysis. During period I, 73 strains presented five distinctive DNA profiles: A, B, C, D, and E. Profile A was the most frequent DNA pattern and was identified in 55 (75.3%) strains; three closely related and four possibly related profiles were also identified. During period II, 80 (68.8%) of 117 strains showed the same endemic profile A identified during period I, 18 (13.7%) closely related profiles and 18 (13.7%) possibly related profiles and, only one strain presented an unrelated profile. Cluster analysis showed a 96% coefficient of similarity between profile A from period I and profile A from period II, which were considered to be from the same clone. The molecular monitoring of MRSA strains permitted the determination of the clonal dissemination and the maintenance of a dominant endemic strain during a 10-year period and the presence of closely and possibly related patterns for endemic profile A. However, further studies are necessary to improve the understanding of the dissemination of the endemic profile in this hospital.371345-5

    The Explanation Dialogues: Understanding How Legal Experts Reason About XAI Methods

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    The Explanation Dialogues project is an expert focus study that aims to uncover expectations, reasoning, and rules of legal experts and practitioners towards explainable artificial intelligence (XAI). We examine legal perceptions and disputes that arise in a fictional scenario that resembles a daily life situation - a bank’s use of an automated decision-making (ADM) system to decide on credit allocation to individuals. Through this simulation, the study aims to provide insights into the legal value and validity of explanations of ADMs, identify potential gaps and issues that may arise in the context of compliance with European legislation, and provide guidance on how to address these shortcomings

    First Italian validation of the “satisfaction with simulation experience” scale (Sse) for the evaluation of the learning experience through simulation

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    Background and aim of the work. Training in simulation through “mannequins” is increasingly widespread among nursing students. In the Italian context, however, there are no tools that measure the degree of student satisfaction after clinical training through simulation. The aim of the study is to provide a first validation in Italian of the Satisfaction with simulation experience” (SSE) scale, a tool already validated in several languages. Methods. After obtaining the author’s consent, the SSE was subjected to forward and backward translation. The content validity was assessed by 5 training experts by calculating the Content Validity Index by Item and by Scale (I-CVI and S-CVI); the face validity was tested on 4 nursing students who had participated in a simulation experience. Subsequently, the SSE was administered to 10 nursing students with testretest after 7 days in order to evaluate the reliability by calculating the reliability coefficient (r) and Cronbach’s α. Results. The author approved the final version of the SSE translated into Italian: I-CVI values>0.80 and S-CVI was 0.94. r is 0.88 and the α of the scale is 0.713. Conclusions. The detected values of I-CVI and S-CVI are satisfactory, demonstrating the validity of the content of the SSE-ITA. The test-retest showed “optimal” reliability and the α was considered acceptable given the little deviation from the original (0.776). Although the results demonstrate satisfactory values, this is a first validation and other studies with larger samples are needed. (www.actabiomedica.it)

    On the Application of a Monolithic Array for Detecting Intensity-Correlated Photons Emitted by Different Source Types

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    It is not widely appreciated that many subtleties are involved in the accurate measurement of intensity-correlated photons; even for the original experiments of Hanbury Brown and Twiss (HBT). Using a monolithic 4x4 array of single-photon avalanche diodes (SPADs), together with an off-chip algorithm for processing streaming data, we investigate the difficulties of measuring second-order photon correlations g2 in a wide variety of light fields that exhibit dramatically different correlation statistics: a multimode He-Ne laser, an incoherent intensity-modulated lamp-light source and a thermal light source. Our off-chip algorithm treats multiple photon-arrivals at pixel-array pairs, in any observation interval, with photon fluxes limited by detector saturation, in such a way that a correctly normalized g2 function is guaranteed. The impact of detector background correlations between SPAD pixels and afterpulsing effects on second-order coherence measurements is discussed. These results demonstrate that our monolithic SPAD array enables access to effects that are otherwise impossible to measure with stand-alone detectors.Comment: 17 pages, 6 figure
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