scholarly journals Gromov Hyperbolicity in Directed Graphs

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 105
Author(s):  
Ana Portilla ◽  
José M. Rodríguez ◽  
José M. Sigarreta ◽  
Eva Tourís
Keyword(s):  
Data Transfer ◽  
Directed Graphs ◽  
Gromov Hyperbolicity ◽  
The Internet ◽  
Classical Definition ◽  
Secure Data ◽  
Potential Applications ◽  
Definition Of

In this paper, we generalize the classical definition of Gromov hyperbolicity to the context of directed graphs and we extend one of the main results of the theory: the equivalence of the Gromov hyperbolicity and the geodesic stability. This theorem has potential applications to the development of solutions for secure data transfer on the internet.

Secure Data Transfer Using Image Steganography

2021 ◽  
Vol 9 (VIII) ◽  
pp. 175-180
Author(s):  
Nisha Manral
Keyword(s):  
Data Transfer ◽  
Digital Images ◽  
Image Steganography ◽  
Secret Message ◽  
The Internet ◽  
Secret Information ◽  
File Formats ◽  
Secure Data ◽  
Other Information ◽  
Weak Points

Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet. For hiding secret information in images, there exists a large variety of steganographic techniques some are more complex than others and all of them have respective strong and weak points. Different applications have different requirements of the steganography technique used. For example, some applications may require absolute invisibility of the secret information, while others require a larger secret message to be hidden. This paper intends to give an overview of image steganography, its uses and techniques. It also attempts to identify the requirements of a good steganographic algorithm and briefly reflects on which steganographic techniques are more suitable for which applications.

STEGANOGRAFI DENGAN MENGGUNAKAN METODE LSB DAN ALGORITMA HILL CIPHER

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Sherly Gina Supratman
Keyword(s):  
Digital Images ◽  
Text Messages ◽  
The Internet ◽  
Digital Imagery ◽  
Least Significant Bit ◽  
Hill Cipher ◽  
Secure Data ◽  
Audio Video ◽  
The Hill

AbstrakJaringan Komunikasi seperti Internet� merupakan jaringan yang tidak aman untuk mentransmisi data, seperti teks, audio,video dan citra digital. Salah satu cara untuk pengamanan data dapat dilakukan dengan menggunakan proses kriptografi dan �steganografi. Penggunaan ini dengan tujuan untuk merahasiakan pesan yang dikirim dan sekaligus menghindarkan pesan tersebut dari kecurigaan pihak lain yang tidak berkepentingan.Pesan yang digunakan dalam makalah ini adalah berupa text dengan menyisipkannya pada gambar. Pada proses kriptografi, pesan yang berupa text akan dienkrip dengan algoritma Hill Chiper, dan kemudian pesan yang telah dienkrip akan dilakukan proses steganografi pada citra digital� 8 bit dengan skala 0 � 255, dengan metode Least Significant Bit ( LSB ).�Kata kunci: Kriptografi, Hill Chiper, Steganografi, Least Significant Bit�AbstractCommunication Networks such as the Internet are unsafe networks for transmitting data, such as text, audio, video and digital imagery. One way to secure data can be done by using cryptography and steganography process. This use is for the purpose of concealing messages being transmitted and avoiding such messages from the suspicion by others who are not interested.The message used in this paper is text by inserting it in the image. In the cryptographic process, text messages will be encrypted with the Hill Chiper algorithm, and then the encrypted message will be steganographed on 8-bit digital images on a scale of 0-255, using the Least Significant Bit (LSB) method.�Keywords: Cryptography, Hill Chiper, Steganography, Least Significant Bit

Understanding the Functions of Jurisdictional Law

2017 ◽  
Author(s):  
Dan Jerker B. Svantesson
Keyword(s):  
International Law ◽  
Legal Theory ◽  
Legal Philosophy ◽  
Law Reform ◽  
The Internet ◽  
Private International Law ◽  
Public International Law ◽  
Important Concept ◽  
Definition Of

This chapter takes us into the domain of legal theory and legal philosophy as it places the questions of Internet jurisdiction in a broader theoretical, and indeed philosophical, context. Indeed, it goes as far as to (1) present a definition of what is law, (2) discuss what are the law’s tools, and (3) to describe the roles of law. In addition, it provides distinctions important for how we understand the role of jurisdictional rules both in private international law and in public international law as traditionally defined. Furthermore, it adds law reform tools by introducing and discussing the concept of ‘market sovereignty’ based on ‘market destroying measures’––an important concept for solving the Internet jurisdiction puzzle.

scholarly journals AB0677 REVISING THE DEFINITION OF REACTIVE ARTHRITIS AND DIFFERENTIATION FROM UNDIFFERENTIATED SPONDYLOARTHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1633.2-1634
Author(s):  
F. Cosan ◽  
O. M. Gedar
Keyword(s):  
Causative Agent ◽  
Reactive Arthritis ◽  
Case Reports ◽  
Experimental Studies ◽  
Classification Criteria ◽  
General Definition ◽  
Parasitic Infections ◽  
Undifferentiated Spondyloarthritis ◽  
Classical Definition ◽  
Definition Of

Background:Reactive arthritis (ReA) is defined by 1999 ACR criteria as arthritis preceding a bacterial genitourinary (GUS) or gastrointestinal (GIS) infection in 3 days-6 weeks and evidence of triggering infection. Recently, ReA is classified as SpA and patients who do not fulfill SpA criteria are classified as undifferentiated spondyloarthritis (USpA) according to ASAS/EULAR SpA classification criteria.Objectives:In several case reports which are associated with other infective agents are reported and the definition is extended for some clinicians so that SpA which is occurred after any infection is called as ReA. On the other hand, some researchers still accept the classical definition of ReA. The problem with the heterogeneity of opinions and unstandardized definition of ReA hinders studies about pathogenesis and standardization of treatments. In this study, we aimed to determine the spectrum of the use of the definition of reactive arthritis in publications in PubMed between 2009-2019.Methods:The ReA keyword is searched in PubMed for the years between 2009-2019. 248 different publications have been identified and included in this research. 89 articles, 47 reviews, 108 case reports, 2 guidelines, and 2 editorials reviewed for the definition of ReA.Results:Only 42.7% (106 patients) of these publications meet the classical definition which suggests ReA after only GIS and GUS infections. In 4 (1.6%) of the publications ReA was defined after GIS, GUS and oropharyngeal infections; in 3 (1,2%) of the publications after any bacterial infection; in 9 (3.6%) of the publications after any infection. In 8 (3.2%) of the publications, ReA and USPA was used correspondingly. In 39 (15,7%) of the publications the term agent related, ReA was used without making a general definition for ReA. 79 publications (31,9%) have not defined ReA.According to causative agent and ReA relationship, in 64 (24,6%) general infective agents, in 75 (30,2%) classical agents, in 22 (8,9%) other bacterial agents, in 23 (9,3%) streptococcus, in 10(4%) intravesical BCG, in 6 (2.4%) HIV, in 6 (2.4%) tuberculosis, in 12 (4,8%) clostrudium difficle, in 2 (0.8%) parasites were reported. In 31 (12,5%) of the publications the causative agent for the ReA was unknown, the diagnosis was made clinically.Conclusion:In this study, it is aimed to draw attention terminology intricacy and the need for the standardization of the definition of ReA and USpA. It is clear that to standardize the definition of Rea and USpA is necessary. Between 2009-2019 there are reported cases diagnosed as ReA associated with bacterial infections (especially with Clostridium difficile, streptococcus and tuberculosis infections), and viral infections (by a majority with HIV), and parasitic infections. It is not clear if we need to define them classically or define them as USPA. Another important consideration is the necessity of extended laboratory investigations to find out the real causative agent even if the patient is clinically diagnosed with ReA. The requirement of the differentiation between ReA and USpA must be revealed for therapeutic researches.References:[1]A proposal for the classification of patients for clinical and experimental studies on reactive arthritis. Pacheco-Tena C, Burgos-Vargas R, Vázquez-Mellado J, Cazarín J, Pérez-Díaz JA. J Rheumatol. 1999 Jun;26(6):1338-46.[2]The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Rudwaleit M, van der Heijde D, Landewé R, Akkoc N, Brandt J, Chou CT, Dougados M, Huang F, Gu J, Kirazli Y, et al. Ann Rheum Dis. 2011;70:25–31.Disclosure of Interests:None declared

scholarly journals Secure Data Transfer through Audio Signal with LSA

2015 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
R. Valarmathi ◽  
G. M. Kadhar Nawaz
Keyword(s):  
Data Transfer ◽  
Audio Signal ◽  
Secure Data

scholarly journals Generalized Wavelet Fisher’s Information of1/fαSignals

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Julio Ramírez-Pacheco ◽  
Homero Toral-Cruz ◽  
Luis Rizo-Domínguez ◽  
Joaquin Cortez-Gonzalez
Keyword(s):  
Fisher Information ◽  
Gaussian Noise ◽  
Structural Breaks ◽  
Wavelet Domain ◽  
Fractional Gaussian Noise ◽  
Domain Definition ◽  
Potential Applications ◽  
Definition Of ◽  
The Time Domain ◽  
Fisher's Information

This paper defines the generalized wavelet Fisher information of parameterq. This information measure is obtained by generalizing the time-domain definition of Fisher’s information of Furuichi to the wavelet domain and allows to quantify smoothness and correlation, among other signals characteristics. Closed-form expressions of generalized wavelet Fisher information for1/fαsignals are determined and a detailed discussion of their properties, characteristics and their relationship with waveletq-Fisher information are given. Information planes of1/fsignals Fisher information are obtained and, based on these, potential applications are highlighted. Finally, generalized wavelet Fisher information is applied to the problem of detecting and locating weak structural breaks in stationary1/fsignals, particularly for fractional Gaussian noise series. It is shown that by using a joint Fisher/F-Statistic procedure, significant improvements in time and accuracy are achieved in comparison with the sole application of theF-statistic.

Synthesis of Planar, Compliant Four-Bar Mechanisms for Compliant-Segment Motion Generation

1999 ◽  
Vol 123 (4) ◽  
pp. 535-541 ◽  
Author(s):  
L. Saggere ◽  
S. Kota
Keyword(s):  
Compliant Mechanisms ◽  
Shape Change ◽  
Synthesis Method ◽  
Elastic Equilibrium ◽  
Body Motion ◽  
Motion Generation ◽  
Generation Task ◽  
Potential Applications ◽  
Flexible Segment ◽  
Definition Of

Compliant four-bar mechanisms treated in previous works consisted of at least one rigid moving link, and such mechanisms synthesized for motion generation tasks have always comprised a rigid coupler link, bearing with the conventional definition of motion generation for rigid-link mechanisms. This paper introduces a new task called compliant-segment motion generation where the coupler is a flexible segment and requires a prescribed shape change along with a rigid-body motion. The paper presents a systematic procedure for synthesis of single-loop compliant mechanisms with no moving rigid-links for compliant-segment motion generation task. Such compliant mechanisms have potential applications in adaptive structures. The synthesis method presented involves an atypical inverse elastica problem that is not reported in the literature. This inverse problem is solved by extending the loop-closure equation used in the synthesis of rigid-links to the flexible segments, and then combining it with elastic equilibrium equation in an optimization scheme. The method is illustrated by a numerical example.

Removing the Nationality Paradigm from Herodotus’ Histories

2018 ◽  
Vol 10 (2) ◽  
pp. 306-323
Author(s):  
Salvatore Tufano
Keyword(s):  
Case Studies ◽  
Final Section ◽  
Fifth Century ◽  
Test Cases ◽  
Persian Wars ◽  
Classical Definition ◽  
Mixed Language ◽  
Archaic Greece ◽  
The Common ◽  
Definition Of

Abstract The present paper suggests that the recurring appeal to kinship diplomacy undermines a fixed idea of ‘nation’ in Archaic Greece, especially in the first two decades of the fifth century BC. It aims to present a series of test cases in Herodotus that explain why contemporary patterns and theories on ancient ethnicity can hardly explain the totality of the historical spectrum. Blood ties could sometimes fortify ethnic relationships, as in the case of Aristagoras’ mission to Sparta (Hdt. 5.49.3), since the common Greekness could elicit the Spartan to help to the Ionians. In other times, the same blood ties were applied to divine genealogies, and they could also be used to show the feeble devotion of cities like Argos to the Greek cause (7.150.2: Xerxes expects the Argives to join the Persian cause, since they descend from Perses). Habits and traditions, often taken as indicia of national feeling, could be thought of as clues of ancient migrations (so the Trojans became Maxyes in Lybia: 4.191). Even language might not help in justifying ethnic relationships: for instance, the Greeks living in the Scythian Gelonus spoke a mixed language (4.108). These few case studies may shed a different light on the classical definition of Greekness (to hellenikon) in terms of blood, language, cults, and habits, all given by Herodotus (8.144). Far from being a valid label for all the Greeks of the fifth century, this statement owes much to a specific variety of the language of kinship diplomacy. The final section argues for the opportunity to avoid the later and misleading idea of nation when studying Herodotus and the age of the Persian Wars, which are instead characterized by various and contrasting strategies. Greek groups and ethne can be better described as networks of lightly defined communities.

Design and Simulation of a PC to PC Communication Network via Fiber Optic Cable

2013 ◽  
Vol 824 ◽  
pp. 206-214
Author(s):  
Babatunde A. Adegboye ◽  
B.B. Bello ◽  
K.R. Ekundayo ◽  
Juliet N. Adegboye
Keyword(s):  
Communication Network ◽  
Fiber Optic ◽  
Data Transfer ◽  
The Internet ◽  
Serial Port ◽  
Fiber Optic Cable ◽  
Optical Transmitter ◽  
Wireless Medium ◽  
Fiber Optic Communication ◽  
Optic Communication

This paper deals with data transfer from one computer to another. The serial ports of the computer are used. MAX 232 is used to convert RS 232 logic to TTL logic and then an optical transmitter circuit is used to transmit data via fiber optic cable. The optical transmitter circuit has an LED which is matched with the cable. At the receiver an optical receiver circuit is used which receives data using a photo diode and a MAX 232 again to convert TTL logic to RS 232 for the serial port at the receiving end computer. The desired baud rate can be set. Although the internet can be used, but due to its time consuming nature, one can implement data transfer using wireless medium, though at a relatively high cost. The need, therefore, is felt for fiber optic communication which is cheaper and more suitable for the task. It is cheaper than wireless medium and is prone to lesser loss as compared to wireless medium.

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