143,609 research outputs found
A Consistent Metric For Performance Evaluation of Multi-Object Filters
No full textThe concept of a miss-distance, or error, between a reference quantity and its estimated/controlled value, plays a fundamental role in any filtering/control problem. Yet there is no satisfactory notion of a miss-distance in the well-established field of multi-object filtering. In this paper, we outline the inconsistencies of existing metrics in the context of multi-object miss-distances for performance evaluation. We then propose a new mathematically and intuitively consistent metric that addresses the drawbacks of current multi-object performance evaluation metrics
Convergence analysis of the Gaussian mixture PHD filter
No full textThe Gaussian mixture probability hypothesis density (PHD) filter was proposed recently for jointly estimating the time-varying number of targets and their states from a sequence of sets of observations without the need for measurement-to-track data association. It was shown that, under linear-Gaussian assumptions, the posterior intensity at any point in time is a Gaussian mixture. This paper proves uniform convergence of the errors in the algorithm and provides error bounds for the pruning and merging stages. In addition, uniform convergence results for the extended Kalman PHD Filter are given, and the unscented Kalman PHD Filter implementation is discussed. © 2007 IEEE.</p
A quantitative study of the biotransformation of insulin-enhancing VO(2+) compounds
No full textPotentiometric (pH titrations) and spectroscopic (electron paramagnetic resonance) methods have been used to determine the thermodynamic stability constants of the various VO2+ complexes formed after the interaction of four insulin-enhancing vanadium compounds, [VO(6-mepic)(2)], cis-[VO(pic)(2)(H2O)], [VO(acac)(2)], and [VO(dhp)(2)], where 6-mepic, pic, acac, and dhp indicate the deprotonated forms of 6-methylpicolinic acid, picolinic acid, acetylacetone, and 1,2-dimethyl-3-hydroxy-4(1H)-pyridinone, with high molecular mass [human serum apotransferrin (hTf) and human serum albumin (HSA)] and low molecular mass (lactate) components of blood serum. In particular, log beta values for the formation of (VO)hTf (13.0 +/- A 0.5), (VO)(2)hTf (25.5 +/- A 0.5), (VO)HSA (9.1 +/- A 1.0), (VO) (2) (d) HSA (20.9 +/- A 1.0), cis-VO(dhp)(2)(hTf) (25.5 +/- A 0.6), cis-VO(dhp)(2)(HSA) (25.9 +/- A 0.6), (VO)hTf(lact) (14.5 +/- A 0.8), (VO)(2)hTf(lact)(2) (28.5 +/- A 0.8), (VO)hTf(pic) (15.6 +/- A 0.8), and (VO)(2)hTf(pic)(2) (30.4 +/- A 0.8) were determined. The values of the stability constants were used to compare the calculated composition of ternary and quinary systems with that recently proposed by some of us through electron paramagnetic resonance and density functional theory methods (Sanna et al. in Inorg. Chem. 49:174-187, 2010) and to predict the distribution of VO2+ ion in blood serum when one of the four insulin-enhancing vanadium compounds studied, [VO(carrier)(2)], is administered
A Metric for Performance Evaluation of Multi-Target Tracking Algorithms
No full textPerformance evaluation of multi-target tracking algorithms is of great practical importance in the design, parameter optimization and comparison of tracking systems. The goal of performance evaluation is to measure the distance between two sets of tracks: the ground truth tracks and the set of estimated tracks. This paper proposes a mathematically rigorous metric for this purpose. The basis of the proposed distance measure is the recently formulated consistent metric for performance evaluation of multi-target filters, referred to as the OSPA metric. Multi-target filters sequentially estimate the number of targets and their position in the state space. The OSPA metric is therefore defined on the space of finite sets of vectors. The distinction between filtering and tracking is that tracking algorithms output tracks and a track represents a labeled temporal sequence of state estimates, associated with the same target. The metric proposed in this paper is therefore defined on the space of finite sets of tracks and incorporates the labeling error. Numerical examples demonstrate that the proposed metric behaves in a manner consistent with our expectations.</p
Adaptive target birth intensity for PHD and CPHD filters
No full textThe standard formulation of the probability hypothesis density (PHD) and cardinalised PHD (CPHD) filters assumes that the target birth intensity is known a priori. In situations where the targets can appear anywhere in the surveillance volume this is clearly inefficient, since the target birth intensity needs to cover the entire state space. This paper presents a new extension of the PHD and CPHD filters, which distinguishes between the persistent and the newborn targets. This extension enables us to adaptively design the target birth intensity at each scan using the received measurements. Sequential Monte-Carlo (SMC) implementations of the resulting PHD and CPHD filters are presented and their performance studied numerically. The proposed measurement-driven birth intensity improves the estimation accuracy of both the number of targets and their spatial distribution
Bernoulli Forward-Backward Smoothing for Joint Target Detection and Tracking
No full textIn this correspondence, we derive a forward-backward smoother for joint target detection and estimation and propose a sequential Monte Carlo implementation. We model the target by a Bernoulli random finite set since the target can be in one of two "present" or "absent" modes. Finite set statistics is used to derive the smoothing recursion. Our results indicate that smoothing has two distinct advantages over just using filtering: First, we are able to more accurately identify the appearance and disappearance of a target in the scene, and second, we can provide improved state estimates when the target exists.</p
Security enhancement of a remote user authentication scheme using bilinear pairings and ECC
No full textMeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Data for: Dependency on FDI Inflows and Stock Market Linkages
No full textData includes:1/The stock indices of Japan, Korea, Singapore, Taiwan, Hong Kong, China, and Vietnam.2/ FDI inflows to Vietnam3/ Net FDI inflow over GD
Association of religiosity and spirituality with survival among older adults: a systematic review
No full textAim: In a world where the aging population and prevalence of chronic degenerative diseases and life-threatening conditions have been increasing, identifying factors that can improve the living conditions of these populations is of paramount importance. The aim of the present research was to conduct a systematic literature review to investigate the impact of religion and spirituality on longevity. Subject and methods: Studies published in English that assessed the association between religiosity or spirituality and survival were identified by searching electronic databases (PubMed, PsycINFO, and CINAHL) and were independently reviewed by two authors. Results: A total of 13 prospective cohort studies were included in this review, including seven that found a negative association between religiosity and mortality and six that showed mixed results. Conclusion: Most studies highlighted the reduction in the risk of mortality, particularly among subjects who engaged in religious activities with an active social component. The linkage between religiosity and longevity might be mediated by the social support of the religious community, better health behavior, and mental health. However, most studies found a reduction in all-cause mortality even after adjusting for these mediating factors, indicating that other important mechanisms might have been involved
- …
