3D Cat Research Articles

Boundary rigidity of 3D CAT(0) cube complexes

The boundary rigidity problem is a classical question from Riemannian geometry: if (M,g) is a Riemannian manifold with smooth boundary, is the geometry of M determined up to isometry by the metric dg induced on the boundary ∂M? In this paper, we consider a discrete version of this problem: can we determine the combinatorial type of a finite cube complex from its boundary distances? As in the continuous case, reconstruction is not possible in general, but one expects a positive answer under suitable contractibility and non-positive curvature conditions. Indeed, in two dimensions Haslegrave gave a positive answer to this question when the complex is a finite quadrangulation of the disc with no internal vertices of degree less than 4. We prove a 3-dimensional generalisation of this result: the combinatorial type of a finite CAT(0) cube complex with an embedding in R3 can be reconstructed from its boundary distances. Additionally, we prove a direct strengthening of Haslegrave’s result: the combinatorial type of any finite 2-dimensional CAT(0) cube complex can be reconstructed from its boundary distances.

A secure scheme based on polar-coded and 3D mixed domain scrambling in W-band MMW-RoF system

With the development of 6G network, the issue of physical layer security in optical fiber communication is becoming more and more significant. In this paper, a polar-coded encryption and 3D mixed domain scrambling secure scheme in W-band millimeter-wave radio-over-fiber (MMW-RoF) system is proposed. The keys are divided into the shared key and the dynamic key, and the shared key is used for constellation-level encryption and 3D mixed domain scrambling with 3D cat mapping, the dynamic key is used for polar code encryption. After RoF system transmission, the scheme can achieve a large key space of 10453, which is powerful enough to resist brute-force. Because the key is randomly selected in the codebook, this encryption scheme has the effect of resisting chosen-plaintext attacks. In terms of reliability, compared to traditional polar-OFDM and 3D QAM polar-OFDM, this scheme can achieve ∼0.4 dB and ∼0.45 dB gains in receiver sensitivity, respectively. So, the proposed scheme has good security performance and reliability performance, which has a significant potential for application in future optical networks.

Plant catalase in silico characterization and phylogenetic analysis with structural modeling

BackgroundCatalase (EC 1.11.1.6) is a heme-containing tetrameric enzyme that plays a critical role in signaling and hydrogen peroxide metabolism. It was the first enzyme to be crystallized and isolated. Catalase is a well-known industrial enzyme used in diagnostic and analytical methods in the form of biomarkers and biosensors, as well as in the textile, paper, food, and pharmaceutical industries. In silico analysis of CAT genes and proteins has gained increased interest, emphasizing the development of biomarkers and drug designs. The present work aims to understand the catalase evolutionary relationship of plant species and analyze its physicochemical characteristics, homology, phylogenetic tree construction, secondary structure prediction, and 3D modeling of protein sequences and its validation using a variety of conventional computational methods to assist researchers in better understanding the structure of proteins. ResultsAround 65 plant catalase sequences were computationally evaluated and subjected to bioinformatics assessment for physicochemical characterization, multiple sequence alignment, phylogenetic construction, motif and domain identification, and secondary and tertiary structure prediction. The phylogenetic tree revealed six unique clusters where diversity of plant catalases was found to be the largest for Oryza sativa. The thermostability and hydrophilic nature of these proteins were primarily observed, as evidenced by a relatively high aliphatic index and negative GRAVY value. The distribution of 5 sequence motifs was uniformly distributed with a width length of 50 with the best possible amino residue sequences that resemble the plant catalase PLN02609 superfamily. Using SOPMA, the predicted secondary structure of the protein sequences revealed the predominance of the random coil. The predicted 3D CAT model from Arabidopsis thaliana was a homotetramer, thermostable protein with 59-KDa weight, and its structural validation was confirmed by PROCHECK, ERRAT, Verify3D, and Ramachandran plot. The functional relationships of our query sequence revealed the glutathione reductase as the closest interacting protein of query protein. ConclusionsThis theoretical plant catalases in silico analysis provide insight into its physiochemical characteristics and functional and structural understanding and its evolutionary behavior and exploring protein structure-function relationships when crystal structures are unavailable.

Performance Analysis of Chaotic Neural Network and Chaotic Cat Map Based Image Encryption

Nowadays, chaotic systems are used quite often, especially in image encryption applications. Hypersensitivity to the initial conditions, limited field-changing signs and irregular movements make these systems one of the critical elements in scientific matters such as cryptography. These systems are divided in two parts as discrete time and continuous time in terms of their dimensions and properties. Gray level image encryption applications generally use one-dimensional and color image encryption applications generally use multi-dimensional chaotic systems. In this study, Tent Map, Cat Map, Lorenz, Chua, Lu chaotic systems were used for chaotic neural network based image coding application and Logistic Map and 3D Cat Map chaotic systems were used for 3D chaotic Cat Map based image encryption application. The encrypted image and the original image were examined by various analysis methods. As a result of these analyzes, it was seen that both applications gave very successful results. Analyzes have shown that the chaotic neural network based image coding algorithm is more secure and successful.

Differential cryptanalysis of diffusion and confusion based information confidentiality mechanism

Wireless multimedia communications have progressed significantly in recent years. As a result, there is an increasing demand for more secure media transmission to protect multimedia information. Image encryption systems have been presented throughout the years, but those based on chaotic maps are the most secure and trustworthy due to the inherent properties in such types of multimedia contents involving the pixels strong correlation and data handling capacities. In this research, we have performed differential cryptanalysis of a recently suggested cryptosystem based on a three dimensional (3D) logistic map and 3D Cat map. The originally proposed approach was based on diffusion and confusion strategy. The vulnerabilities in the understudy cryptosystem lead to the successful proposed cryptanalysis attack. The original ciphers are recovered by means of a chosen-plaintext attack. The recovered data is also subjected to some statistical analysis to check the quality.

3D CAT Scan and Gastric Volumetry in the Planning of Revisional Bariatric Surgery.

Background: The planning of revisional bariatric surgery is a complex process. The availability of accurate anatomical information is especially important for the planning of such challenging surgical procedures, we present our initial experience using three-dimensional-computed tomography (3D-CT) images to preoperatively assess the anatomy of patients before bariatric revisional surgery. Methods: We used 3D reconstructed images of CT scans to assess the anatomy and plan revisional surgery in 144 patients 98 of them had a previous sleeve gastrectomy 41 had a previous gastric by-pass and 4 Vertical banded gastroplasties. An effervescent preparation was used to distend the stomach and the proximal bowel allowing volume estimation. Results: Eleven sleeve patients underwent a re-sleeve gastrectomy and 44 were revised to a "Roux-en-Y" gastric bypass (RYGBP). Forty-two patients with a previous gastric by-pass were revised due to weight regain or other issues and 4 patients with previous vertical banded gastroplasty (VBGP) were revised to RYGBP. 3D-CT scans provided valuable information for the planning of all revisional procedures by offering accurate information about the existing anatomy and measures of the volume of the gastric pouch, the size of the gastro-jejunal anastomosis in gastric by-pass cases, or the volume and shape of the gastric tube in gastric sleeve cases. Conclusion: 3D-CT is a fast, widely available, reliable, and accurate tool to assess the anatomy after bariatric procedures. This noninvasive method can be particularly useful for the evaluation of postbariatric patients with failures, suboptimal results, and complications, and for the planning of revisional surgery.

Image Encryption and Authentication With Elliptic Curve Cryptography and Multidimensional Chaotic Maps

Many researchers have used the properties of the popular Elliptic Curve Cryptography(ECC) to devise a stronger and faster image encryption algorithm to assure the secrecy of images during online transmission. In this paper, a robust Elliptic curve based image encryption and authentication model for both grayscale and color images has been proposed. The model uses the secure Elliptic Curve Diffie-Hellman(ECDH) key exchange to compute a shared session key along with the improved ElGamal encoding scheme. 3D and 4D Arnold Cat maps are used to effectively scramble and transform the values of plain image pixels. A well-structured digital signature is used to verify the authenticity of the encrypted image prior to decryption. The model produces good-quality cipher images with an average entropy of 7.9993 for grayscale and 7.99925 for the individual components of color images. The model has high average NPCR of 99.6%, average UACI of 33.3% and low correlation for both grayscale and color images. The model has low computational costs with minimized point multiplication operations. The proposed model is robust with high resilience against statistical, differential, chosen-plaintext(CPA), known-plaintext(KPA) and occlusion attacks.

Chaos cloud quantum bat hybrid optimization algorithm

The bat algorithm (BA) has fast convergence, a simple structure, and strong search ability. However, the standard BA has poor local search ability in the late evolution stage because it references the historical speed; its population diversity also declines rapidly. Moreover, since it lacks a mutation mechanism, it easily falls into local optima. To improve its performance, this paper develops a hybrid approach to improving its evolution mechanism, local search mechanism, mutation mechanism, and other mechanisms. First, the quantum computing mechanism (QCM) is used to update the searching position in the BA to improve its global convergence. Secondly, the X-condition cloud generator is used to help individuals with better fitness values to increase the rate of convergence, with the sorting of individuals after a particular number of iterations; the individuals with poor fitness values are used to implement a 3D cat mapping chaotic disturbance mechanism to increase population diversity and thereby enable the BA to jump out of a local optimum. Thus, a hybrid optimization algorithm—the chaotic cloud quantum bats algorithm (CCQBA)—is proposed. To test the performance of the proposed CCQBA, it is compared with alternative algorithms. The evaluation functions are nine classical comparative functions. The results of the comparison demonstrate that the convergent accuracy and convergent speed of the proposed CCQBA are significantly better than those of the other algorithms. Thus, the proposed CCQBA represents a better method than others for solving complex problems.

Research on method of gravity thermal coupling field-flow fractionation based on symmetric encryption algorithm

The most frequently used method includes the gravity field-flow separation and thermal field-flow separation. By analyzing the influence of velocity of carrier flow on the separation effect of gravity field flow, we can know that the movement track of particle in different carrier liquid elution speed was significantly different when the external carrier liquid was continuously injected into the gravity field-flow separation channel, so the additional lift force generated by the thermal field was used to enhance the driving lift force of particles in carrier liquid and the effect of field-flow separation, and thus to achieve the gravity thermal coupling field-flow separation. In order to ensure the accuracy of field-flow separation, the computer vision detection system was used to detect the separation effect of gravity thermal coupling field flow. In this process, the symmetrical encryption optimization algorithm based on 3D cat mapping was used to realize image encryption through image scrambling and image mixing, so as to ensure the integrity of image. Experimental results show that the gravity thermal-coupled field-flow separation method based on symmetric encryption algorithm can separate the starch particles with different sizes effectively, which is suitable for the purification of powdery particles.

Multi-user image encryption algorithm based on synchronized random bits generator in semiconductor lasers network

A chaos-based public channel image encryption algorithm among three users is proposed, where the random bits (RBs) generated in a star-type chaotic laser network can be well synchronized and are used as the keys. The proposed algorithm is simple and efficient. Firstly, random bits with verified randomness are generated from the synchronized chaotic semiconductor lasers in a star-type network at a rate of 10Gb/s. Next, lower-triangular error-bits detection is employed to delete the different bits among all the parties over the public channel. Based on the synchronized RBs, the XOR operation is used to diffuse the plain image. Then the hash algorithm is used to get the control parameters matrix from the plain image, and 3D cat map is used to confuse the pixel position through the parameters matrix. Finally, the encrypted image is transmitted in the public channel. The performance tests results, such as key sensitivity, histogram, correlation, differential attack, robustness and entropy analysis, show that the suggested algorithm prevents a powerful computational eavesdropper. Besides, the running speed of this algorithm is linear with the size of plain image. These results open possibilities for multi-user secure communication application.

Three-dimensional Cat Virtual Anatomy: Development of an Interactive Virtual Anatomical Software

Background Three-dimensional (3D) virtual models are novel tools to teach veterinary anatomy. Objective The aim of the present study was to create a 3D cat image software and a library of cross-sectional images. Methods Modeling of the 3D cat organs and structures was done with Autodesk Maya, version 2017 (Autodesk Inc., San Rafael, California, USA) and ZBrush, version 4R7 (Pixologic, Los Angeles, CA, USA) software. In order to obtain the images for the library, three cadavers of adult cats were used, with the following techniques: 1) scanning by magnetic resonance imaging (MRI) at 3-mm intervals, 2) scanning by computed tomography (CT) at 2-mm intervals, and 3) photographing of 178 transverse cuts at 2.5-mm intervals from the frozen cadavers. Out of all the images, thirty images of each technique were selected. An interactive software was developed with the modeled 3D cat and the selected images using Unity, version 5.4 (Unity Technologies, San Francisco, CA, USA). Results A virtual 3D cat model was obtained with 418 labeled structures of the skeletal, muscular, circulatory, nervous, respiratory, digestive, urinary, and integumentary systems. The virtual interface enables the manipulation of the 3D cat in all views and the visualization of the selected images in a chosen localization along the body of the cat. The library of images allows comparison among CT, MRI and photographs of transverse cuts. Conclusions The software interface facilitates the access to the content for the user. Sectional images of the cat and of its body structures can be easily understood. This new 3D software of cat anatomy is another tool that can be used in teaching veterinary anatomy.

Secure image compression approach based on fusion of 3D chaotic maps and arithmetic coding

Advances in digital image processing and communications have created a great demand for real-time secure image transmission over the networks. However, the development of effective, fast and secure dependent image compression-encryption systems are still a research problem as the intrinsic features of images. A new approach is suggested in this study for partial image encryption-compression that adopts chaotic three-dimensional (3D) cat map to de-correlate relations among pixels in conjunction with an adaptive thresholding technique that is utilised as a lossy compression technique instead of using complex quantisation techniques and also as a substitution technique to increase the security of the cipher image. The proposed scheme is based on employing both of lossless compression with encryption on the most significant part of the image after contourlet transform. However, the least significant parts are lossy compressed by employing a simple thresholding rule and arithmetic coding to render the image totally unrecognisable. Due to the weakness of 3D cat map to chosen plain text attack, the suggested scheme incorporates a mechanism to generate random key depending on the contents of the image (context key). Several experiments were done on benchmark images to insure the validity of the proposed technique.

A modified image selective encryption-compression technique based on 3D chaotic maps and arithmetic coding

The advances in digital image processing and communications have created a great demand for real–time secure image transmission over the networks. However, the development of effective, fast and secure dependent image compression encryption systems are still a research problem as the intrinsic features of images such as bulk data capacity and high correlation among pixels hinds the use of the traditional joint encryption compression methods. A new approach is suggested in this paper for partial image encryption compression that adopts chaotic 3D cat map to de-correlate relations among pixels in conjunction with an adaptive thresholding technique that is utilized as a lossy compression technique instead of using complex quantization techniques and also as a substitution technique to increase the security of the cipher image. The proposed scheme is based on employing both of lossless compression with encryption on the most significant part of the image after contourlet transform. However the least significant parts are lossy compressed by employing a simple thresholding rule and arithmetic coding to render the image totally unrecognizable. Due to the weakness of 3D cat map to chosen plain text attack, the suggested scheme incorporates a mechanism to generate random key depending on the contents of the image (context key). Several experiments were done on benchmark images to insure the validity of the proposed technique. The compression analysis and security outcomes indicate that the suggested technique is an efficacious and safe for real time image’s applications.

Image Encryption Using Arnold Map

Nowadays transmission of data over the network is increasing and the data can be in the format of text, image, audio and video. Images are widely used in maximum applications of daily life. Image encryption is one of the most recent area of research to meet the demand during image transmission. Transformation of image from one form to erroneous form is called as image encryption. So, it can be secured from unauthorized users. The security of encrypted image is completely dependent on two important aspects i.e. the strength of the cryptographic algorithm and the confidentiality of the key. This paper proposes an algorithm of image encryption based on 3D Arnold cat map combined with logistic chaotic map. To evaluate the security of the encrypted image of this scheme, key space analysis and differential attack are performed. Several test images are used to demonstrate the validity of the proposed encryption algorithm. The experiment result shows that the proposed algorithm provides an efficient and secure approach to real-time image encryption and transmission.

A novel image encryption scheme based on 3D bit matrix and chaotic map with Markov properties

Based on 3D cat map, reverse 3D cat map and an improved class of chaotic maps with Markov properties, an effective bit-level image encryption scheme is proposed. Firstly, we convert the plain-image into binary matrix, and use the sum of all bits in the binary matrix as a part of secret keys to resist chosen-plaintext attack and known-plaintext attack. Secondly, we design a mapping which maps a random bit position to another random bit position rather than using traditional sequential visiting the plain-image. Thirdly, a chaotic map with Markov properties is used in the diffuse process. This kind of chaotic map has good chaotic natures than the Logistic map, which keeps the uniformity and low autocorrelation. The results of simulation and security analysis show that the proposed image encryption scheme is able to resist various attacks and has excellent encryption performance.

Higher-order singular value decomposition-based discrete fractional random transform for simultaneous compression and encryption of video images

Existing image compression and encryption methods have several shortcomings: they have low reconstruction accuracy and are unsuitable for three-dimensional (3D) images. To overcome these limitations, this paper proposes a tensor-based approach adopting tensor compressive sensing and tensor discrete fractional random transform (TDFRT). The source video images are measured by three key-controlled sensing matrices. Subsequently, the resulting tensor image is further encrypted using 3D cat map and the proposed TDFRT, which is based on higher-order singular value decomposition. A multiway projection algorithm is designed to reconstruct the video images. The proposed algorithm can greatly reduce the data volume and improve the efficiency of the data transmission and key distribution. The simulation results validate the good compression performance, efficiency, and security of the proposed algorithm.

Cryptanalysis and enhancements of image encryption based on three-dimensional bit matrix permutation

Recently, an image encryption based on three-dimensional bit matrix permutation (TDBMP) has been proposed by Zhang et al. The encryption scheme has combined Chen chaotic system with a 3D Cat map in the permutation stage, and defined a new mapping rule (double random position permutation) and utilized key-streams generated by Logistic map to confuse the permuted image. However, we have found that this scheme is vulnerable to chosen plaintext attack and is not applicable to secure communications. In this paper, the shortcomings of TDBMP have been analysed and a chosen plaintext attack has been proposed to break the scheme. After that, we propose an enhanced algorithm to overcome the presented shortcomings in the above original scheme. Experimental results also illustrate that the enhanced scheme not only maintains the merits of the original one, but also has better cryptographic performances in key space, plaintext sensitivity, statistical characteristics, robustness against cropping attack and execution speed, and can therefore effectively ensure a secure image communication.

Fractura supracondílea del codo y el mito de la rotación del fragmento distal

The main concern in treating supracondylar fractures of the elbow in the child is to control the rotation of the distal fragment. When the doctor detects the rotation, to achieve the reduction the proximal fragment must be controlled, placing the shoulder in an anatomical position and performing the maneuver. Our objective is to show that in the supracondylar fractures of the humerus in the child, the fragment that rotates is the proximal and not the distal, as has been argued. Material and methodWe conducted a prospective study in 72 pediatric patients, out of 150 who came to the emergency room with supracondylar elbow fractures; Grades II-B and III of Gartland, which showed rotation on the radiograph. We performed AP and strict side radiographs and a 3D CAT of the shoulder and elbow. The diameters of the distal end of the proximal fragment and the proximal end of the distal fragment were measured and compared in each patient. The relationship between rotated fractures, fracture type and lateral or medial displacement was sought.

Exploiting Optics Chaos for Image Encryption-Then-Transmission

A novel symmetric image encryption-then-transmission system based on optical chaos using semiconductor lasers is proposed. In this paper, with identical chaotic injection from a master laser, two slave lasers (SL1 and SL2) can output similar chaotic signals served as chaotic carrier to transmit image. Meanwhile, the chaotic signal of SL1 can be used to generate the key of the encryption scheme. After employing the three-dimensional (3D) cat map and logistic chaotic map, the positions of image pixels are shuffled, and the relationship between the cipher-image and the plain-image is confused simultaneously. Therefore, the system can resist the common attacks such as statistical attack, differential attack, and brute force attack. Through numerical simulations, the high quality chaos synchronization between SL1 and SL2 is obtained. When the chaos masking technique is adopted, the image encrypted by the proposed encryption scheme can be successfully transmitted and decrypted in a 10 km single mode fiber channel from SL1 to SL2, which is accompanied by a bit error rate of less than ${\rm{6.18\,\times \,10}}^{- 19}$ . Exhaustive tests about security analysis are carried out, demonstrating the valuable feasibility and high security of the image encryption-then-transmission system.

내러티브 시각화 구현을 위한 비언어적 표현 연구－3D 고양이 캐릭터 "Puss"를 중심으로

내러티브 시각화 구현을 위한 비언어적 표현 연구－3D 고양이 캐릭터 "Puss"를 중심으로