1,720,991 research outputs found
PARTICLE FILTERING METHOD FOR OBJECT TRACKING AND SENSOR
Get PDFGenerally, there is no analytic solution to object tracking problems in non-linear
non-Gaussian scenarios, which is a common type of problem nowadays. A particle
filter is a numerical method that can be applied to any class of model regardless
of linear and Gaussian assumptions as in the Kalman filter, and has the same
benefits of constant memory requirement and real-time recursive estimation. In
this report, a hidden Markov model is set up for state and observation evolution,
and both the particle filter and the Kalman filter are developed and applied to
generate tracking results. Our results show that in linear and Gaussian case, the
performance of particle filtering is very close to the classic Kalman filter, which
achieves the Cramer?Rao lower bound, while the particle filtering method can be
applied much more extensively when linear and Gaussian assumptions are not
justified in real problems.
In both object tracking and other problems such as detection, sensor management
is an issue, as there has to be a trade-off between performance and cost. As
sensors are commonly utilized for multiple purposes, a generic performance measure
based on mutual information is developed. An overall sensor cost is computed
by summing up the one-time cost of installation and the life-time cost of operation.
To make the information gain and the cost comparable, a bit-dollar exchange rate is
defined to compute the monetary value of the information gain. By combining the
monetary gain and the cost into a single objective, a sensor configuration strategy
can be chosen among multiple options
Thermal Feasibility Analysis of Periodic Real-Time Tasks with Jitter
No full textIt is well-known that spatial and temporal variations in power density within a processor core creates thermal hot spots where the temperatures can exceed 100 C. Such temperatures can degrade device reliability and adversely affect processor performance. This problem is expected to become even more acute in the coming years because average power densities are expected to double in the next decade. As a result, estimating the worst-case peak temperature for a given processor workload is an important problem.
This report presents an algorithm to estimate the worst-case peak temperature for a given real-time workload in a multi-core system. The challenge is to find the worst-case arrival pattern for the given real-time workload that results in the maximum peak temperature when the tasks are executed using a work-conserving scheduler. The proposed algorithm improves a solution from literature by relaxing some of its restrictive assumptions. In the cases where the assumptions are satisfied, the estimates from the proposed algorithm and the scheme from literature are the same. In all other cases, the estimates from the proposed algorithm are much less conservative and hence, more accurately estimate the achievable worst-case temperature
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Synchronization and distributed agreement in real-time systems.
No full textA Byzantine fault is an arbitrary behavior on the part of a hardware component, a software module or a logical entity. The focus of this dissertation is on problems related to designing systems that are resilient to Byzantine faults. This work is important in computer systems that are designed to control critical real-time applications such as avionics, life-support systems, nuclear reactors, automobile engines and process control systems. The main emphasis of the dissertation is on developing techniques for synchronizing system components and ensuring distributed agreement in the presence of Byzantine faults. First, hardware and software schemes are proposed for synchronizing the local clocks in the nodes of a distributed system. These schemes compare favorably with existing schemes in terms of cost as well as tightness of synchronization. Next, a clock distribution scheme is proposed for delivering the clock signal to the components within a node without creating any timing uncertainties. The key aspect of this scheme is that both delay and skew are taken into account when determining the layout of the clock lines. The global time base that results from these two solutions can be used to simplify fault tolerant algorithms for various design problems in real-time systems. This is illustrated by presenting a checkpointing and rollback recovery algorithm that requires considerably less time and space overhead than other algorithms. Finally, a solution is derived for diagnosing components with Byzantine faults. This is useful for reducing the number of faults that need to be tolerated to meet a specified reliability requirement which in turn reduces the overhead imposed by any algorithm that is resilient to Byzantine faults. In short, the work accomplished in this dissertation demonstrates that it is not necessary to limit oneself to small distributed systems in order to achieve a high reliability. The techniques developed here are economical in small and in large distributed systems.PhDComputer scienceElectrical engineeringUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/162512/1/9013992.pd
- …
