1,721,004 research outputs found
Instrumentation and Measurement in Communication Systems
No full textThe demand for ubiquitous connectivity is challenging the physical constraints placed upon current communication systems. In addition, customers expect higher and higher quality from their service providers. Consequently, equipment manufacturers are required to produce systems that can be quickly deployed and provide bandwidth-efficient communications. To meet this goal, instrumentation and measurements play a fundamental and invaluable role.
At early stages of equipment development, rigorous testing is performed to both assess system functionality and performance and ensure system interoperability. Moreover, the increasingly complex nature of communication signals is placing additional pressure on design teams, already faced with tight project deadlines. Not only must the developer perform conformance testing; he/she must also quickly infer from measurement results root causes of possible technical problems.
The strategic importance of measurements in the field of communication systems is corroborated by the significant increase in the number of papers on this topic - both submitted and accepted - experienced by IEEE Transactions on Instrumentation and Measurement (TIM) in recent years. Unfortunately, many submitted papers are rejected because they fall clearly outside the journal scope. This fact motivated us – as researchers in the field—to write this paper to specify what can be considered an instrumentation and measurement (I&M) technical contribution in the field of communication systems
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Improved nonlinear filtering for target tracking.
Full text linkThe objective of this research is to develop robust and accurate tracking algorithms for various tracking applications. These tracking problems can be formulated as nonlinear filtering problems. The tracking algorithms will be developed based on an emerging promising nonlinear filter technique, known as sequential importance sampling (nick-name: particle filtering). This technique was introduced to the engineering community in the early years of 2000, and it has recently drawn significant attention from engineers and researchers in a wide range of areas. Despite the encouraging results reported in the current literature, there are still many open questions to be answered. For the first time, the major research effort will be focusing on making improvement to the particle filter based tracking algorithm in the following three aspects: (I) refining the particle filtering process by designing better proposal distributions (II) refining the dynamic model by using multiple-model method, (i.e. using switching dynamics and jump Markov process) and (III) refining system measurements by incorporating a data fusion stage for multiple measurement cues
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Multiple Real-Constant Multiplication for Computationally Efficient Implementation of Digital Transforms
Full text linkThe need to multiply signals by vectors (or matrices) of constants is fundamental and frequently arises in many areas of electrical and computer engineering.In their hardware implementations, performance issues such as circuit area, delay, and power consumption heavily influence the design process.It is well known that multiplication of a signal by a constant can be implemented multiplierless as a network of shifts and additions, and that these computational networks, termed shift-add networks, can lend to higher performing circuit implementations than when using general multipliers.There is a rich body of work on the optimization of shift-add networks, known as the multiple constant multiplication (MCM) problem.However, the optimization strategies that have been developed for the MCM traditionally assume that the vector multiplications being optimized always stem from integer constants.This assumption breaks down for many real-world applications, where the target constants for MCM optimization are real numbers rather than integers.In these situations there is flexibility in how constants are quantized in digital circuits that can be leveraged.Thus, it is desirable to have a method of jointly optimizing both the constant quantization error and the shift-add network simultaneously.This dissertation addresses this need by providing a problem framework and algorithms for joint quantization/MCM optimization and, through a series of experiments, shows that there is a potential for tremendous benefit when the optimization of quantization and shift-add networks is executed in one unified problem framework.After reviewing the relevant work, this dissertation rigorously develops the aforementioned joint optimization framework, describing the metrics used for quantization error, and culminates in a formal problem statement.We call this joint optimization problem the multiple real-constant multiplication problem (MRCM) in order to distinguish it from the traditional MCM problem that operates exclusively with integer constants, which we hereafter refer to as the multiple integer-constant multiplication (MICM) problem.Then, we consider three different cost models used for evaluating shift-add networks and, with each model, we determine the potential advantages of using our MRCM framework over the traditional MICM approach.First, we consider the traditional adder-count cost model.We start by formally defining the MRCM problem in the context of this cost model, and then describe a series of theoretical developments centered around finitizing and pruning the search space, leading to an efficient algorithm for solving the problem.Next, via extensive randomized experiments, we show that our joint framework leads to a reduction on the number of adders by 15%–60% on moderate size problems.In particular, for vectors of arbitrary constants, we show a possibility for 20%–60% reduction with less than 10% vector approximation error for both frameworks, whereas for vectors of low-pass filter coefficients, a 15%–30% reduction is possible without exceeding 10% error in frequency response.Second, we consider an adder-bits cost model, whereby instead of simply counting the number of adders, we compute the combined bitwidth of all the adders.To solve the MRCM problem in this context, we introduce two search algorithms—one greedy and one optimal, each guided by a novel MRCM-aware heuristic.Next, we discuss a randomized experiment, in which we compare both algorithms to an MICM-targeted heuristic.We observe that the greedy search finds solutions with an average cost improvement of 13% over the MICM solution with the trials considered, and the optimal search finds an additional improvement of 6%.Third, we consider a prominent gate-level cost model from the literature that.This gate-level model consider the bitwidths of an adder's inputs and output along with the relative alignment of the inputs/output due to bit shifting, when computing the adder cost.To solve the MRCM problem in this context, a novel greedy algorithm is developed that uses a functional programming approach to solving the MRCM problem.Next, we experimentally show this algorithm to offer an improvement of up to 18%, over a competing MICM algorithm, on small instances having 20 8-bit constants, increasing to up to 59% improvement on larger instances having 80 5-bit constants.Finally, we conclude the work by offering recommendations for possible future work in the development of efficient MRCM algorithms and novel problem formulations for optimizing MCM circuits
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