125,064 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
A Note on Koblitz Curves over Prime Fields
No full textBesides the well-known class of Koblitz curves over binary fields, the class of
Koblitz curves over prime fields with is also
of some practical interest. By refining a classical result of Rajwade for the cardinality of , we obtain a simple formula of in terms of the norm on the ring of Eisenstein integers, that is, for some with and some unit ,
holds. This establishes an interesting relation between the number of points on this class of curves and the number of elements of their underlying fields, they are given by the norm of two integers of whose difference is just a unit. It is also interesting to note that such relationship has already been derived for the case of Koblitz curves over binary fields. Some tools that are useful in the computation of cubic residues are also developed
Improved base-phi expansion method for Koblitz curves over optimal extension fields
No full textAn improved base-phi expansion method is proposed, in which the bit-length of coefficients is shorter and the number of coefficients is smaller than in Kobayashi's expansion method. The proposed method meshes well with efficient multi-exponentiation algorithms. In addition, two efficient algorithms based on the proposed expansion method, named phi-wNAF and phi-SJSF, are presented which significantly reduce the computational effort involved in online precomputation by using the property of Frobenius endomorphism. The proposed algorithms noticeably accelerate computation of a scalar multiplication on Koblitz curves over optimal extension fields (OEFs). In particular, for OEFs where the characteristic is close to 32 bits or 64 bits, the required number of additions is reduced up to 50% in comparison with Kobayashi's base-phi scalar multiplication algorithm. Finally, a method that significantly reduces the memory usage of the precomputation table at the expense of slightly more computation is presented
Provably Sublinear Point Multiplication on Koblitz Curves and its Hardware Implementation
No full textAbstract. We describe algorithms for point multiplication on Koblitz curves using multiple-base expansions of the form k = P ±τ a (τ − 1) b and k = P ±τ a (τ − 1) b (τ 2 − τ − 1) c. We prove that the number of terms in the second type is sublinear in the bit length of k, which leads to the first provably sublinear point multiplication algorithm on Koblitz curves. For the first type, we conjecture that the number of terms is sublinear and provide numerical evidence demonstrating that the number of terms is significantly less than that of τ-adic non-adjacent form expansions. We present details of an innovative FPGA implementation of our algorithm and performance data demonstrating the efficiency of our method.
Provably Sublinear Point Multiplication on Koblitz Curves and its Hardware Implementation
No full textWe describe algorithms for point multiplication on Koblitz curves
using multiple-base expansions of the form and
We prove that the number of terms in the second type is sublinear in
the bit length of k, which leads to the first provably sublinear point
multiplication algorithm on Koblitz curves. For the first type, we
conjecture that the number of terms is sublinear and provide
numerical evidence demonstrating that the number of terms is
significantly less than that of -adic non-adjacent form
expansions. We present details of an innovative FPGA
implementation of our algorithm and performance data demonstrating the
efficiency of our method
Enkripsi dan Dekripsi Pesan Menggunakan Kurva Eliptik pada Affine Cipher dengan Metode Koblitz
No full textINDONESIA:
Kriptografi merupakan ilmu matematis yang digunakan untuk mengamankan suatu pesan. Pandemi Covid-19 ini membuat masyarakat mengalami sedikit kesulitan untuk berkomunikasi. Penyampaian informasi secara online belum tentu menjamin keamanannya. Oleh karena itu, diperlukan suatu teknik untuk pengaman pesan. Pada penelitian ini menggunakan Kriptografi Kurva Eliptik pada Affine Cipher dengan metode Koblitz, karena memiliki kelebihan dalam hal panjang kunci yang lebih pendek namun juga memiliki tingkat keamanan yang sama jika dibandingkan dengan algoritma kriptografi asimetris lainnya. Tujuan penelitian ini untuk mengetahui proses enkripsi dan dekripsi menggunakan kurva eliptik pada Affine Cipher dengan metode Koblitz untuk mengamankan pesan teks. Tahapan penelitian ini menggunakan pendekatan kualitatif dengan metode library research. Metode yang digunakan yaitu sesuai pada algoritma Affine Cipher yang menggunakan dua kunci simetris, kemudian kurva eliptik metode Koblitz digunakan untuk proses enkripsi dan dekripsi kunci. Proses enkripsi dari algoritma Affine Cipher dengan rumus C=mP+b (mod n) menghasilkan sebuah ciphertext, sedangkan proses enkripsi kunci menggunakan metode Koblitz dengan rumus x=mk+1 yang kemudian disubstitusikan pada persamaan y^2=x^3+2x+7(mod 127) menghasilkan sebuah cipherkey. Sedangkan, pada proses dekripsi dilakukan dengan mendekripsi cipherkey menggunakan metode Koblitz dengan rumus m=(x-1)/k dan menghasilkan kunci simetris dari algoritma Affine Cipher, selanjutnya akan dilakukan proses dekripsi ciphertext dengan menggunakan rumus P=m^(-1) (C-b)mod n. Hasil dari penelitian ini menunjukkan bahwa proses enkripsi dan dekripsi dapat dilakukan dengan baik serta dapat meningkatkan kemanan suatu pesan, karena adanya penggabungan dua algoritma simetris dan algoritma asimteris.
ENGLISH:
Kriptografi is a mathematical science used to secure a message. The Covid-19 pandemic has made it a little difficult for people to communicate. The delivery of information online does not necessarily guarantee its security. Therefore, a technique is needed for security in this study using Elliptic Curve Cryptography on the Affine Cipher with the Koblitz method, because ithas advantages in terms of shorter key lengths but also has the same level of security when compared to cryptographic algorithms other asymmetrical. The purpose of this study was to know the encryption and decryption process using an elliptic curve on Affine Cipher with the koblitz method to secure text messages. This stage of research uses a qualitative approach with the library research method. The method used is appropriate in the Affine Cipher algorithm which uses two symmetric keys, then the elliptic curve of the Koblitz method is used for the process of encryption and decryption of the key. Encryption process of the Affine Cipher algorithm with formulas generates a ciphertext, while the key encryption process uses the Koblitz method with a formula which is then substituted on the equation generates a cipherkey. Meanwhile, the decryption process is carried out by decrypting the cipherkey using the Koblitz method with the formula and generates a symmetric key from the Affine Cipher algorithm, then the ciphertext decryption process will be carried out using the formula . The results of this study show that the encryption and decryption process can be done well and can improve the security of a message, due to the combination of two symmetric algorithms and asymptomatic algorithms.
ARABIC:
التشفير هو علم رياضي يستخدم لتأمين رسالة. جائحة Covid-19 هذا يجعل من الصعب قليلا على الناس التواصل. تسليم المعلومات عبر الإنترنت لا يضمن بالضرورة أمنها. لذلك ، هناك حاجة إلى تقنية للأمان في هذه الدراسة باستخدام تشفير المنحنى الإهليلجي على تشفير Affine باستخدام طريقة Koblitz ، لأنهيتمتع بمزايا من حيث أطوال المفاتيح الأقصر ولكن لديه أيضا نفس مستوى الأمان عند مقارنته بخوارزميات التشفير غير المتماثلة الأخرى. كان الغرض من هذه الدراسة هو معرفة عملية التشفير وفك التشفير باستخدام منحنى بيضاوي الشكل على Affine Cipher باستخدام طريقة Koblitz لتأمين الرسائل النصية. تستخدم هذه المرحلة من البحث نهجا نوعيا مع طريقة البحث في المكتبة. الطريقة المستخدمة مناسبة في خوارزمية Affine Cipher التي تستخدم مفتاحين متماثلين ، ثم يستخدم المنحنى الإهليلجي لطريقة كوبليتز لعملية تشفير المفتاح وفك تشفيره. عملية تشفير خوارزمية تشفير Affine مع الصيغ يولد نصا مشفرا، بينما تستخدم عملية تشفير المفتاح أسلوب Koblitz مع صيغة الذي يتم استبداله بعد ذلك بالمعادلة يولد مفتاح تشفير. وفي الوقت نفسه ، يتم تنفيذ عملية فك التشفير عن طريق فك تشفير مفتاح التشفير باستخدام طريقة Koblitz مع الصيغة ويولد مفتاحا متماثلا من خوارزمية Affine Cipher ، ثم سيتم تنفيذ عملية فك تشفير النص المشفر باستخدام الصيغة. تظهر نتائج هذه الدراسة أن عملية التشفير وفك التشفير يمكن أن تتم بشكل جيد ويمكن أن تحسن أمان الرسالة ، بسبب الجمع بين خوارزميتين متماثلتين وخوارزميات بدون أعراض
Measurement of the LCG2 and glite file catalogue's performance
No full textWhen the Large Hadron Collider (LHC) begins operation at CERN in 2007 it will produce data in volumes never before seen. Physicists around the world will manage, distribute and analyse petabytes of this data using the middleware provided by the LHC Computing Grid. One of the critical factors in the smooth running of this system is the performance of the file catalogues which allow users to access their files with a logical filename without knowing their physical location. This paper presents a detailed study comparing the performance and respective merits and shortcomings of two of the main catalogues: the LCG File Catalogue and the gLite FiReMan catalogue
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
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