scholarly journals Digital homotopy relations and digital homology theories

2021 ◽  
Vol 22 (2) ◽  
pp. 223
Author(s):  
P. Christopher Staecker
Keyword(s):  
Digital Images ◽  
Continuous Functions ◽  
Homology Theory ◽  
Simplicial Homology ◽  
Digitally Continuous ◽  
New Type ◽  
The Difference ◽  
Cubical Homology

In this paper we prove results relating to two homotopy relations and four homology theories developed in the topology of digital images.<br /><br />We introduce a new type of homotopy relation for digitally continuous functions which we call ``strong homotopy.'' Both digital homotopy and strong homotopy are natural digitizations of classical topological homotopy: the difference between them is analogous to the difference between digital 4-adjacency and 8-adjacency in the plane.<br /><br />We also consider four different digital homology theories: a simplicial homology theory by Arslan et al which is the homology of the clique complex, a singular simplicial homology theory by D. W. Lee, a cubical homology theory by Jamil and Ali, and a new kind of cubical homology for digital images with $c_1$-adjacency which is easily computed, and generalizes a construction by Karaca \&amp; Ege. We show that the two simplicial homology theories are isomorphic to each other, but distinct from the two cubical theories.<br /><br />We also show that homotopic maps have the same induced homomorphisms in the cubical homology theory, and strong homotopic maps additionally have the same induced homomorphisms in the simplicial theory.

scholarly journals Digital fixed points, approximate fixed points, and universal functions

2016 ◽  
Vol 17 (2) ◽  
pp. 159 ◽  
Author(s):  
Laurence Boxer ◽  
Ozgur Ege ◽  
Ismet Karaca ◽  
Jonathan Lopez ◽  
Joel Louwsma
Keyword(s):  
Fixed Point ◽  
Fixed Points ◽  
Digital Images ◽  
Continuous Functions ◽  
Universal Functions ◽  
Approximate Fixed Point ◽  
Fixed Point Properties ◽  
Digitally Continuous ◽  
Approximate Fixed Point Property ◽  
The Relationship

A. Rosenfeld [23] introduced the notion of a digitally continuous function between digital images, and showed that although digital images need not have fixed point properties analogous to those of the Euclidean spaces modeled by the images, there often are approximate fixed point properties of such images. In the current paper, we obtain additional results concerning fixed points and approximate fixed points of digitally continuous functions. Among these are several results concerning the relationship between universal functions and the approximate fixed point property (AFPP).

New analysis of holophotoelastic patterns and their application

1976 ◽  
Vol 11 (1) ◽  
pp. 11-17 ◽  
Author(s):  
J Ebbeni ◽  
J Coenen ◽  
A Hermanne
Keyword(s):  
Numerical Methods ◽  
Dynamic Problems ◽  
Principal Stresses ◽  
Optical Elements ◽  
New Type ◽  
The Difference ◽  
Fringe Patterns

This paper shows that by the use of a new type of diffuser it is possible in photo-holoelasticimetry, without any addition of optical elements or particular preparation of the specimen, to record simultaneously but separately fringe patterns respectively related to the sum and the difference of the principal stresses. The value of intensity of the interfering light reaching the hologram plate is established and hence the equations of the recorded pseudoisopachic fringe patterns are given. Used successfully for the study of particular static problems, where numerical methods are very difficult or impossible, the present interferometer is also suited for dynamic problems.

scholarly journals Research Status and Development Trend of Magnetic Fluid Acceleration Sensors

2021 ◽  
pp. 10-15
Author(s):  
Mu Xueyu ◽  
Yang Shaojie ◽  
Kong Xiangdong
Keyword(s):  
General Structure ◽  
Inertial Mass ◽  
Development Trend ◽  
Research Progress ◽  
Acceleration Sensor ◽  
Magnetic Liquid ◽  
Existing Problems ◽  
Acceleration Sensors ◽  
New Type ◽  
The Difference

As a new type of accelerometer, in recent years, the magnetic liquid acceleration sensor has attracted widespread attention worldwide, and related research results have also continued to emerge. This article mainly introduces the theoretical basis and general structure of the magnetic liquid acceleration sensor, and according to the difference of inertial mass, briefly describes the research progress of the magnetic liquid acceleration sensor by national and foreign scholars in recent years and some in existing problems. Finally, suggestions and prospects for the future development trend of the magnetic liquid acceleration sensor are given.

scholarly journals Implementasi Pengamanan Citra Digital Menggunakan Algoritma ICE

2020 ◽  
Vol 1 (3) ◽  
pp. 284
Author(s):  
Josua Alfiandi Sinuhaji
Keyword(s):  
Digital Image ◽  
Block Cipher ◽  
Digital Images ◽  
Source Code ◽  
Digital Imagery ◽  
The Subject ◽  
Data Theft ◽  
The Difference ◽  
Cryptographic Techniques ◽  
Rotation Function

Digital imagery is currently very widely used, so it is very vulnerable to data theft by unauthorized parties. In order to maintain the security of digital images can be done by using cryptographic techniques. Cryptographic techniques can encode digital images by encrypting them in the form of passwords that are not understood. ICE is a block cipher published by Kwan in 1997. This algorithm has a structure similar to DES, but with additional bit permutations that do not depend on the key in the rotation function. There are various types of ICE variants, namely Thin-ICE, ICE standard, and ICE-n. The difference between the three is the length of the keyword used and the number of rounds. The Thin-ICE algorithm uses 64 bits and 8 turns. The ICE standard uses 64 bits and 16 round keys. The ICE-n algorithm uses keys 64n bits and 16n turns. The use of this type of algorithm can be adjusted to the needs of users where Thin-ICE has the lowest level of security among the three, while ICE-n is the highest. This algorithm does not become the subject of a patent and the source code can be used freely.Keywords : Cryptography, Digital Image,Algorithm,ICE.

scholarly journals Ideological Phantoms of Civilisation and Culture: Identity and Tolerance

2019 ◽  
pp. 1-13
Author(s):  
Natalia Yu. Beregovaya ◽  
Olga A. Karlova
Keyword(s):  
Community Based ◽  
Culture Studies ◽  
Historical Method ◽  
Philosophical Aspect ◽  
New Type ◽  
The Subject ◽  
The Difference ◽  
Ideological Manipulation ◽  
Global World ◽  
Modelling Methods

The article considers the philosophical aspect of defining the immanence and attribution of the concept of “tolerance” to the culture itself. The subject of the research is especially relevant due to the modern processes that are happening in the global world, and the difference in key methodological positions of modern Russian and Western science on this issue today. The purpose of this study is to clarify the philosophical basis of the existing opposition of societies with traditional ethical cultures (Russia, China) and the ‘new-type’ poly-state European ethnic community. Based on the analysis of current social processes in Russia and Europe using the comparative historical method, modelling methods and model extrapolation in the field of culture studies, social psychology and political science, the article identifies the main approaches to ethnic and social identity, their cultural and ideological components. The authors prove the hypothesis that culture requires designation of its border with another culture, recognition of this border, which distinguishes and confirms cultural semantics. Denial of this fact is a method of ideological manipulation of the ethno-social consciousness of society in the framework of globalisation processes

Difference Synchronization of Identical and Nonidentical Chaotic and Hyperchaotic Systems of Different Orders Using Active Backstepping Design

2018 ◽  
Vol 13 (5) ◽  
Author(s):  
Eric Donald Dongmo ◽  
Kayode Stephen Ojo ◽  
Paul Woafo ◽  
Abdulahi Ndzi Njah
Keyword(s):  
Chaotic System ◽  
Initial Conditions ◽  
Lyapunov Stability Theory ◽  
The State ◽  
State Variables ◽  
State Variable ◽  
New Type ◽  
The Difference ◽  
Synchronization Scheme ◽  
Hyperchaotic Systems

This paper introduces a new type of synchronization scheme, referred to as difference synchronization scheme, wherein the difference between the state variables of two master [slave] systems synchronizes with the state variable of a single slave [master] system. Using the Lyapunov stability theory and the active backstepping technique, controllers are derived to achieve the difference synchronization of three identical hyperchaotic Liu systems evolving from different initial conditions, as well as the difference synchronization of three nonidentical systems of different orders, comprising the 3D Lorenz chaotic system, 3D Chen chaotic system, and the 4D hyperchaotic Liu system. Numerical simulations are presented to demonstrate the validity and feasibility of the theoretical analysis. The development of difference synchronization scheme has increases the number of existing chaos synchronization scheme.

Tattooing Attack

2014 ◽  
Vol 6 (3) ◽  
pp. 30-46
Author(s):  
Jia-Hong Li ◽  
Tzung-Her Chen ◽  
Wei-Bin Lee
Keyword(s):  
Digital Images ◽  
Image Authentication ◽  
Tamper Detection ◽  
Authentication Scheme ◽  
Tampering Detection ◽  
New Type ◽  
Detection Schemes

Image authentication must be able to verify the origin and the integrity of digital images, and some research has made efforts in that. In this paper, we reveal a new type of malicious alteration which we call the “Tattooing Attack”. It can successfully alter the protected image if the collision of the authentication bits corresponding to the altered image and the original watermarking image can be found. To make our point, we chose Chang et al.'s image authentication scheme based on watermarking techniques for tampering detection as an example. The authors will analyze the reasons why the attack is successful, and then they delineate the conditions making the attack possible. Since the result can be generally applied into other schemes, the authors evaluate such schemes to examine the soundness of these conditions. Finally, a solution is provided for all tamper detection schemes suffering from the Tattooing Attack.

Out of sight, out of mind? Supplier spatial proximity in French public procurement

2014 ◽  
Vol 27 (6) ◽  
pp. 486-500 ◽  
Author(s):  
Olivier Mamavi ◽  
Haithem Nagati ◽  
Frederick T. Wehrle ◽  
Gilles Pache
Keyword(s):  
Public Procurement ◽  
Spatial Proximity ◽  
Management Competencies ◽  
Content Type ◽  
The Public ◽  
Feature Evaluation ◽  
Negative Effect ◽  
New Type ◽  
The Difference ◽  
The Impact

Purpose – The purpose of this paper is to study the impact of spatial proximity on supplier selection in the French public sector. While French public procurement legislation forbids consideration of supplier location in the procurement process, public contractors may still rely on spatial proximity for complex transactions necessitating mutual adjustments with suppliers. Design/methodology/approach – Using French Official Journals (BOAMP), the authors compiled 565,557 transactions completed on three public procurement markets between 6,182 contractors and 26,570 suppliers, over a period of six years (between 2006 and 2011). The authors conducted a two-level hierarchical linear auto-regression analysis and a feature evaluation analysis for all transactions. Findings – The paper finds significant variation between the transactions on different markets: a negative effect of spatial proximity on the number of contract notices in the public market and a positive effect of spatial proximity on the number of notices in the services and supplies markets. The difference lies in the levels of mutual adjustment required to optimally manage the relationship between public contractor and supplier. Research limitations/implications – The research is based on an econometric analysis conducted uniquely in the French context, which calls into question the external validity of the results obtained. The study also rests on segmentation into three aggregate markets, which might be considered too general. Originality/value – Rather than analyze public contractors’ perceptions of the importance of the criterion of spatial proximity, the paper examines 565,557 actual transactions. The results point to the emergence of a new type of relationship with certain suppliers, which should lead public contractors to integrate relationship management competencies, in addition to legal and economic competencies, in the organization of calls for tenders.

scholarly journals THERMODYNAMICS OF FRIEDMANN EQUATION AND MASSLIKE FUNCTION IN GENERAL BRANEWORLD

2009 ◽  
Vol 24 (31) ◽  
pp. 5877-5888 ◽  
Author(s):  
TAO ZHU ◽  
JI-RONG REN ◽  
SHU-FAN MO
Keyword(s):  
Apparent Horizon ◽  
Friedmann Equation ◽  
Curvature Correction ◽  
First Law Of Thermodynamics ◽  
New Type ◽  
Braneworld Model ◽  
The Difference ◽  
Correction Terms

Using the generalized procedure proposed by S. F. Wu et al.23 recently, we construct the first law of thermodynamics on apparent horizon in a general braneworld model with curvature correction terms on the brane and in the bulk, respectively. The explicit entropy formular of apparent horizon in the general braneworld is worked out. We also discuss the masslike function which associated with a new type first law of thermodynamics of the general braneworld in detail. We analyze the difference between the conventional thermodynamics and the new type thermodynamics on apparent horizon. At last, the discussions about the physical meanings of the masslike function have also been given.

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