Concealing secret information in an image so that any perceptible evidence of the image alteration is insignificant, is known as image steganography. Image steganography can be implemented with either spatial or trans...
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Concealing secret information in an image so that any perceptible evidence of the image alteration is insignificant, is known as image steganography. Image steganography can be implemented with either spatial or transform domain techniques. Spatial domain-based algorithms, generally the most widely used ones, refer to the process of embedding the secret information in the least significant bit positions of the cover image pixels. This paper proposes a chaotic tent map-based bit embedding as a novel steganography algorithm with a multicore implementation. The potential reasons for using chaotic maps in image steganography are sensitivity of these functions to initial conditions and control parameters. The computational complexity of the sequential least significant bit algorithm is known to be O(n). Hence, time complexity of the encryption/decryption algorithm is also a very important aspect. With the advantages offered by multicore processors, the proposed steganography algorithm can now be explicitly parallelized using the OpenMP API. As a pre-embedding operation, the quality of the randomness of the chaotic number sequences is tested with a NIST cryptographic test suite. The quality of the stego image is validated with statistical parameters such as structural similarity index (SSIM), mean square error (MSE) and peak signal-to-noise ratio (PSNR). Moreover, exploiting data parallelism inherent in the algorithm, multicore implementation of the algorithm with OpenMP API has also been reported. Proposed parallel version of the technique has been tested on five test samples of images for scalability analysis and results indicate significant speed up as compared to the sequential implementation of the technique.
The C++ language continually evolves through formal specifications established by its standards committee, proposing new features to maintain $\mathrm{C}++$ as a relevant programming language while improving usability...
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ISBN:
(数字)9798331524937
ISBN:
(纸本)9798331524944
The C++ language continually evolves through formal specifications established by its standards committee, proposing new features to maintain $\mathrm{C}++$ as a relevant programming language while improving usability, performance, and portability across platforms. With the addition of parallel Standard Template Library (STL) algorithms in C++17, programmers can now leverage parallel processing capabilities via vendor-neutral parallel execution policies. This study presents an adaptation of the NAS parallel Benchmarks (NPB)—a well-established suite of applications for evaluating parallel architectures-by porting its sequential C-style code to use C++ STL abstractions and performance-portable parallelism features. Our goals are to (1) assess the suitability of C++ STL for scientific applications like the ones in the NPB and (2) provide a comparative performance and portability of STL algorithms’ parallel execution policies across different multicore architectures (x86 and AArch64). Results indicate that the performance of parallel STL algorithms is often close to that of optimized handwritten versions (OpenMP, Intel TBB, and FastFlow) on different architectures, with notable shortfalls. Across all NPB benchmarks, the STL algorithms’ geometric mean shows sequential execution times that are between 3.76% and $\mathrm{6. 9 \%}$ higher, while parallel executions may reach a geometric mean of up to $\mathrm{2 1. 2 1 \%}$ higher execution time.
K-means is a popular clustering algorithm with significant applications in numerous scientific and engineering areas. One drawback of K-means is its inability to identify non-linearly separable clusters, which may lea...
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HPC is a widely used term, often referred to the applications, architectures and programming models and tools targeting highly parallel machines such as those of the *** lists. Recent advances in computing hardware re...
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With the continuous increase in data size and model complexity, the computational workload has grown rapidly, posing a significant challenge to the capabilities of computer data processing and simulation calculations....
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ISBN:
(数字)9798350361674
ISBN:
(纸本)9798350361681
With the continuous increase in data size and model complexity, the computational workload has grown rapidly, posing a significant challenge to the capabilities of computer data processing and simulation calculations. Therefore, parallel programming based on multicore and cluster architectures has become one of the mainstream technologies to enhance program execution efficiency and numerical computation efficiency. The theoretical foundations of parallel program computing have been applied in various aspects of engineering applications and theoretical simulations. In this paper, a new parallel PID anti-integral saturation controller is designed for a second-order closed-loop control system of unmanned aerial vehicles (UAVs). It compares and analyzes the runtime, execution efficiency, and speedup ratio of parallel programs and general serial programs under the same scenario. The experimental results demonstrate that parallel computing significantly improves the simulation program's efficiency for PID controller anti-saturation control systems under identical scenarios, exhibiting a high speedup ratio on the existing computing platform. Additionally, this study consolidates common issues encountered in MATLAB parallel program design, offering valuable insights into overcoming challenges in this domain.
Fortran's prominence in scientific computing requires strategies to ensure both that legacy codes are efficient on high-performance computing systems, and that the language remains attractive for the development o...
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作者:
Marzolla, Moreno
Center for Inter-Department Industrial Research ICT Bologna Italy
Mini-applications are widely used in parallel computing for testing and benchmarking purposes. However, many existing mini-applications are not suitable for teaching, since they require advanced knowledge of algebra, ...
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Cluster Computing Systems (CCS) is a type of technology that not only causes computing power improvement but also utilizes energy to a lesser degree by taking advantage of parallel programming while processing and rea...
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ISBN:
(数字)9798331596651
ISBN:
(纸本)9798331596668
Cluster Computing Systems (CCS) is a type of technology that not only causes computing power improvement but also utilizes energy to a lesser degree by taking advantage of parallel programming while processing and reading massive amounts of data. We can have multiple Central Processing Units (CPUs) and storage devices (disks) where the massive size of data can be processed. However, Cluster Computing System also comes with its own set of challenges such as if for a reason the node stops operating, nodes stops communicating with each other and the data transfer doesn’t happen due to poor network which can lead to bottleneck while processing massive amounts of data. To overcome these issues, a well reputed tech giant known as Google, came up with a solution known as MapReduce. MapReduce is a framework designed for Big Data which takes care of processing large amounts of data over various servers. In this paper, we outline how CCS works and the challenges it faces today in the age of massive data. The introduction to some well received measures of Big Data are presented by us in this paper. These solutions show us the way we can address the issues we face in CSS. The primary goal of this writing is to look into the issues that we might face and the most efficient ways to resolve it in CSS.
As high-performance computing technologies advance, the significance of parallel programming in various domains is becoming increasingly evident since it allows us to harness the power of heterogeneous computing and s...
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ISBN:
(数字)9798350364606
ISBN:
(纸本)9798350364613
As high-performance computing technologies advance, the significance of parallel programming in various domains is becoming increasingly evident since it allows us to harness the power of heterogeneous computing and solve complex problems more efficiently. However, for students to master this type of computation and be able to apply it in different contexts, it requires understanding how measuring and optimizing parallel code impacts its performance. This paper presents an approach to enhancing students' comprehension of parallel performance metrics through an interactive exercise that complements lectures on parallel performance and improves assessment.
HPC is a widely used term, often referred to the applications, architectures and programming models and tools targeting highly parallel machines such as those of the *** lists. Recent advances in computing hardware re...
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ISBN:
(数字)9798331524937
ISBN:
(纸本)9798331524944
HPC is a widely used term, often referred to the applications, architectures and programming models and tools targeting highly parallel machines such as those of the *** lists. Recent advances in computing hardware resources require application of HPC techniques when using much smaller machines. Indeed, proper parallel programming tools and applications are needed also to exploit parallel hardware resources in personal computers (laptops, desktops, servers). This paper outlines key challenges in designing master’s degree programs in HPC and shares lessons learned from various experiences in developing and implementing such programs in Italy and Europe.
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