1,720,964 research outputs found
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
A Contrast-Channel Embedding Approach for Image Steganography: Balancing Capacity and Imperceptibility
No full textSteganography, the practice of concealing information within seemingly ordinary media, is essential for protecting sensitive data in today’s digital era. As cyber threats evolve and data transmission grows, ensuring secure and undetectable information hiding becomes increasingly challenging. This study introduces two novel Contrast Channel Embedding (CCE) techniques to optimize steganographic embedding: Mid-Range Contrast Channel Embedding (MCCE) and Extreme-Range Contrast Channel Embedding (ECCE). MCCE targets mid-range contrast areas, avoiding extremes, while ECCE leverages extremely low and high contrast regions, excluding the mid-range. Unlike conventional methods that rely solely on smooth or textured regions, our approach combines gradient-based contrast analysis with RGB contrast thresholds to identify ideal embedding zones. Low-contrast areas enhance imperceptibility by minimizing visible artifacts but limit embedding capacity. In contrast, high-contrast regions offer greater capacity and robustness due to pixel variation, though they must be selected carefully to preserve image quality. We employ Least Significant Bit (LSB) substitution to embed the hidden data efficiently. Experimental results demonstrate that MCCE and ECCE significantly enhance steganographic performance over traditional LSB-based techniques in terms of imperceptibility, maintain a reasonable payload capacity, and improve robustness against detection. Specifically, MCCE achieves PSNR improvements of up to 23.077%, 17.942%, and 12.490%, while ECCE achieves 23.050%, 17.915%, and 12.463%, comparing against multiple existing methods. Both methods also yield consistently higher SSIM scores across various images with a fixed message length of 8192 bytes. These results demonstrate the effectiveness of our approach in providing a comprehensive and secure solution to conceal information in digital images while maintaining visual fidelity
An Efficient Computation and Storage Outsourcing Process with Verification for Light Weight Devices
No full textPerformance evaluation of Grain family and Espresso ciphers for applications on resource constrained devices
No full textPerformance evaluation of Grain family and Espresso ciphers for applications on resource constrained devices
No full textA secure stream cipher is an effective security solution for applications running on resource-constrained devices. The Grain family of stream ciphers (Grain v1, Grain-128, and Grain-128a) is a family of stream ciphers designed for low-end devices. Similarly, Espresso is a lightweight stream cipher that was developed recently for 5G wireless mobile communication. The randomness of the keystream produced by a stream cipher is a good indicator of its security strength. In this study, we have analyzed the randomness properties of the keystreams produced by both the Grain Family and Espresso ciphers using the statistical packages DieHarder and NIST STS. We also analyzed their performances in two constrained devices (ATmega328P and ESP8266) based on three attainable parameters, namely computation time, memory, and power consumption. Keywords: Stream cipher, Randomness, Dieharder, NIST ST
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
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