1,720,958 research outputs found
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
Enhancing The Performance Of Digital Image Data Hiding Using Reduced Difference Expansion Technique And Constant Base Point
Full text linkThe last few decades have been marked by a rapid growth and significant
enhancement of the internet infrastructures, i.e., the internet has become a broad network
enabling many enterprises around the world to interact while sharing multimedia data.
Nevertheless, this technology has brought many challenges related to securing private
and sensitive information which has led to the application of cryptography technique as
a mean for securing data by encrypting them. However, since the encrypted data can be
seen by active and sophisticated intruders during the transmission, this may lead to its
suspicion which can result in unauthorized access. Thereby, data hiding (which is also
called information hiding) is another technique for securing commutation via the public
network. Data hiding is one of the best and most challenging fields dealing with securing
organizational sensitive information due to many factors such as identity theft,
information phishing, user privacy, network policy violation, contents and copyright
protection. It is performed by utilizing some carriers to conceal private information which
is further extracted later to verify and validate the genuineness.
Digital steganography has been recognized among the recent and most popular data
hiding techniques. Steganography is the practice of concealing confidential information
in the codes that make up the digital files. Such digital files can be an image, audio, video,
and text. Different from cryptography, however, steganography provides security by
disguising the presence of communication. It originates from the concept that if the
communication is visible, the suspicion or attack is obvious. Hence, the main goal is to
always disguise the presence of the hidden confidential data. Recently, various data
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hiding methods based on digital image steganography have been already suggested by
several researchers around the globe. The main goal was to improve the security,
embedding capacity and the quality of the stego image. However, research have shown
that there is still a challenge to achieve a good visual quality of the stego media while
preserving a good embedding capacity. In this direction, this study aims at proposing a
new data hiding approach that enhances the quality of the stego image and the embedding
capacity. That is, the suggested approach enhances the existing data hiding methods by
utilizing pixel block, constant base point for each pixel block and the reduced difference
expansion scheme (RDE-scheme) for grayscale digital images.
Accordingly, the suggested enhancement is detailed as follows. First, the existing
reduced difference expansion scheme (RDE-scheme) for reducing the difference values
is enhanced in order to get possible small values to be used while concealing the secret
data into the cover image. The main objective behind this enhancement is to allow data
to be concealed while preserving the quality of the stego image. Notice that the suggested
RDE-scheme does not only enhance the quality but also it solves the problem of
underflow and overflow. The underflow is encountered when the pixel value in the stego
image is below 0 (Pixel value < 0) while the overflow occurs when it is greater than
255 (Pixel value > 255). Second, the new constant base point for each pixel block is
chosen differently for the sake of increasing the visual quality of the stego image. Third,
we have adjusted the size of the pixel block which achieves a high embedding capacity
while distorting the cover media from quad of quad (4 × 4 ) to quad, block of size 2 by 2
(2 × 2). Besides, the effect of varying the size of the secret data with respect to the quality
of the stego image is also investigated throughout this study.
Overall, based on the experimental results, good visual quality of the stego image
which is evaluated by measuring the peak signal-to-noise ratio (PSNR) and good
embedding capacity (measured in bits) are yielded compared to the previous approach,
i.e., the proposed method is effective in terms of maintaining both visual quality of the
stego image and the embedding capacity.
Index terms— Data hiding, information security, reduced difference expansion, digital
steganography, cover image, stego image, confidential data
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Beberapa dekade terakhir internet telah menjadi jaringan luas yang
memungkinkan banyak perusahaan di seluruh dunia untuk berinteraksi sambil berbagi
data multimedia. Ini merupakan tanda bahwa infrastruktur internet telah tumbuh dan
berkembang secara signifikan. Namun, teknologi ini memiliki banyak tantangan dalam
hal pengamanan informasi yang bersifat sensitif dan pribadi sehingga mendorong
penerapan teknik kriptografi untuk mengamankan data dengan cara mengenkripsinya.
Teknik kriptografi memiliki kekurangan yaitu hasil enkripsi dapat dilihat oleh penyusup
(intruders) selama transmisi sehingga menyebabkan kecurigaan yang berakibat pada
tindakan akses yang bersifat ilegal. Untuk mengurangi hal ini, data hiding dapat
dimanfaatkan untuk mengamankan informasi tersebut. Data hiding adalah salah satu
teknik terbaik untuk mendapatkan data tetapi memiliki banyak tantangan permasalahan
seperti pencurian identitas, phising, pelanggaran kebijakan jaringan dan hak cipta. Untuk
mendapatkan kemanan data, data hiding memanfaatkan beberapa media untuk
menyembunyikan informasi dan dapat diekstrak untuk memverifikasi keasliannya.
Salah satu teknik data hiding yang paling terkenal adalah steganografi digital.
Teknik ini menyembunyikan informasi rahasia kedalam file digital seperti citra digital,
audio, video dan teks. Berbeda dengan kriptografi, steganografi memberikan keamanan
informasi dengan menyamarkannya dalam file digital. Penyebab digunakannya tindakan
ini adalah jika komunikasi terlihat maka akan mengundang kecurigaan yang
mengakibatkan terjadi serangan seperti yang dijelaskan sebelumnya. Oleh karena itu,
tujuan utama dari teknik ini adalah menyamarkan informasi rahasia dengan
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menyembunyikannya kedalam file yang digunakan. Akhir-akhir ini, beberapa teknik data
hiding dengan menggunakan citra digital telah banyak dikembangkan oleh beberapa
peneliti di seluruh dunia. Tujuan utama mereka adalah untuk meningkatkan keamanan,
kapasitas penyisipan dan kualitas dari citra stego. Sampai saat ini, banyak penelitian yang
menunjukkan bahwa masih menjadi tantangan untuk mendapatkan kualitas media stego
yang baik dengan kapasitas penyisipan yang tinggi. Dengan maksud yang sama,
penelitian ini mengusulkan konsep pendekatan baru dalam hal data hiding yang dapat
meningkatkan kualitas dan kapasitas dari citra stego.
Pendekatan tersebut dilakukan dengan cara meningkatkan metode data hiding
yang sudah ada dengan memanfaatkan blok piksel, penentuan base point yang konsisten
untuk masing-masing blok dan mereduksi difference expansion untuk citra abu-abu.
Rincian dari pendekatan tersebut adalah sebagai berikut. Pertama, skema reduksi
difference expansion (RDE) ditingkatkan untuk mendapatkan nilai terkecil yang akan
digunakan dalam penyembunyian data kedalam citra carrier. Tujuannya adalah
memungkinkan data dapat disisipkan dengan tetap menjaga kualitas citra stego tetap baik.
Perlu diketahui bahwa usulan skema RDE tidak hanya meningkatkan kualitas tetapi juga
menyelesaikan masalah overflow dan underflow. Underfow merupakan kondisi piksel
dalam citra stego bernilai kurang dari 0 sedangkan overflow terjadi ketika nilai piksel
melebihi 255. Kedua, base-point yang bersifat konstan untuk masing-masing blok piksel
akan dipilih secara berbeda untuk dapat meningkatkan kualitas visual dari citra stego.
Ketiga, kami mengatur ukuran blok dari quad of quad (4x4) yang memiliki kualitas citra
stego kurang baik menjadi 2x2.
Hal lain yang kami lakukan adalah mengetahui efek dari besar ukuran data yang
digunakan dalam proses penyisipan. Secara keseluruhan, berdasarkan hasil eksperimen,
usulan pendekatan ini memiliki kemampuan yang lebih baik dibandingkan dengan
penelitian sebelumnya yang ditandai dengan kapasitas penyisipan yang lebih tinggi dan
kualitas visual citra stego yang baik yang diukur menggunakan metode signal-to-noise
ratio (PSNR)
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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