Asymptotic stability of rarefaction waves for compressible Navier-Stokes equations with relaxation

The asymptotic stability of rarefaction wave for 1-d relaxed compressible isentropic Navier-Stokes equations is established. For initial data with different far-field values, we show that there exists a unique global in time solution. Moreover, as time goes to infinity, the obtained solutions are shown to converge uniformly to rarefaction wave solution of $p$-system with corresponding Riemann initial data. The proof is based on $L^2$ energy methods

Influence of normal stress on the shear strength of the structural plane considering the size effect

The shear strength of a structural plane is a critical parameter in the analysis of engineering rock stability. Significant differences exist due to the various normal stresses in the structural plane. Therefore, evaluating the rock deformation to effectively determine the influence of normal stresses at different scales on the shear strength of structural planes is of great significance. This study discusses the effects of normal stress and structural plane size on shear strength through numerical simulations and regression analysis. The results showed that the shear strength of the structural plane increases linearly with increasing normal stress. The shear strength of the structural plane decreases with increasing size, and the corresponding curve is exponential. The characteristic size and shear strength increase linearly with increasing normal stress. This paper presents the concrete form of these relationships, which can be used to calculate and predict the shear strength, which has significance in guiding engineering

COMPRESSIBLE NAVIER-STOKES EQUATIONS WITH HYPERBOLIC HEAT CONDUCTION

Abstract. In this paper, we investigate the system of compressible Navier-Stokes equations with hyperbolic heat conduction, i.e., replacing the Fourier's law by Cattaneo's law. First, by using Kawashima's condition on general hyperbolic parabolic systems, we show that for small relaxation time τ , global smooth solution exists for small initial data. Moreover, as τ goes to zero, we obtain the uniform convergence of solutions of the relaxed system to that of the classical compressible Navier-Stokes equations

Fault Injection based Failure Analysis of three CentOS-like Operating Systems

The reliability of operating system (OS) has always been a major concern in the academia and industry. This paper studies how to perform OS failure analysis by fault injection based on the fault mode library. Firstly, we use the fault mode generation method based on Linux abstract hierarchy structure analysis to systematically define the Linux-like fault modes, construct a Linux fault mode library and develop a fault injection tool based on the fault mode library (FIFML). Then, fault injection experiments are carried out on three commercial Linux distributions, CentOS, Anolis OS and openEuler, to identify their reliability problems and give improvement suggestions. We also use the virtual file systems of these three OSs as experimental objects, to perform fault injection at levels of Light and Normal, measure the performance of 13 common file operations before and after fault injection.Comment: 9 pages, 8 figure

Kooperativna evolucija za kvalitetno pružanje usluga u paradigmi Interneta stvari

To facilitate the automation process in the Internet of Things, the research issue of distinguishing prospective services out of many “similar” services, and identifying needed services w.r.t the criteria of Quality of Service (QoS), becomes very important. To address this aim, we propose heuristic optimization, as a robust and efficient approach for solving complex real world problems. Accordingly, this paper devises a cooperative evolution approach for service composition under the restrictions of QoS. A series of effective strategies are presented for this problem, which include an enhanced local best first strategy and a global best strategy that introduces perturbations. Simulation traces collected from real measurements are used for evaluating the proposed algorithms under different service composition scales that indicate that the proposed cooperative evolution approach conducts highly efficient search with stability and rapid convergence. The proposed algorithm also makes a well-designed trade-off between the population diversity and the selection pressure when the service compositions occur on a large scale.Kako bi se automatizirali procesi u internetu stvati, nužno je rezlikovati bitne usluge u moru sličnih kao i identificirati potrebne usluge u pogledu kvalitete usluge (QoS). Kako bi doskočili ovome problemu prdlaže se heuristička optimizacija kao robustan i efikasan način rješavajne kompleksnih problema. Nadalje, u članku je predložen postupak kooperativne evolucije za slaganje usluga uz ograničenja u pogledu kvalutete usluge. Predstavljen je niz efektivnih strategija za spomenuti problem uključujući strategije najboljeg prvog i najboljeg globalnog koje unose perturbacije u polazni problem. Simulacijski rezultati kao i stvarni podatci su korišteni u svrhu evaluacije prodloženog algoritma kako bi se osigurala efikasna pretraga uz stabilnost i brzu konvergenciju. Predloženi algoritam tako.er vodi računa o odnosu izme.u različitosti populacije i selekcijskog pritiska kada je potrebno osigurati slaganje usluga na velikoj skali

InstructCoder: Empowering Language Models for Code Editing

Code editing encompasses a variety of pragmatic tasks that developers deal with daily. Despite its relevance and practical usefulness, automatic code editing remains an underexplored area in the evolution of deep learning models, partly due to data scarcity. In this work, we explore the use of large language models (LLMs) to edit code based on user instructions, covering a broad range of implicit tasks such as comment insertion, code optimization, and code refactoring. To facilitate this, we introduce InstructCoder, the first dataset designed to adapt LLMs for general-purpose code editing, containing highdiversity code-editing tasks. It consists of over 114,000 instruction-input-output triplets and covers multiple distinct code editing scenarios. The dataset is systematically expanded through an iterative process that commences with code editing data sourced from GitHub commits as seed tasks. Seed and generated tasks are used subsequently to prompt ChatGPT for more task data. Our experiments demonstrate that open-source LLMs fine-tuned on InstructCoder can edit code correctly based on users' instructions most of the time, exhibiting unprecedented code-editing performance levels. Such results suggest that proficient instruction-finetuning can lead to significant amelioration in code editing abilities. The dataset and the source code are available at https://github.com/qishenghu/CodeInstruct

Test and analysis of coal adsorption volume of CH4

CH4 in coal seams mainly occurs in free state and adsorbed state. The performance of coal adsorption of CH4 is often affected by various factors such as coal rank, temperature, pressure, particle size and moisture content. In order to study the influence of multi-factor coupling on the Langmuir volume of coal adsorbing CH4 According to the law, coal samples from changcun and zhaozhuang Coal mines in Changzhi area of Shanxi are selected, and the HCA–1 high-pressure adsorption device is used to determine the volume of CH4 adsorbed by coal samples with different ambient temperature, coal sample size and water content, and then the test results of Zhaozhuang Coal mine Based on the design of the Box Behnken test using Design Expert software, a quadratic regression response surface model of coal adsorption CH4 volume was constructed to analyze the influence of temperature, particle size, and moisture content on the volume of coal adsorption CH4 when the three factors are coupled. The volume of coal adsorbed CH4 was predicted and verified, and the engineering application enlightenment of the test results was discussed. The results show that the amount of CH4 adsorption decreases with the increase of temperature, particle size and moisture content; when the ambient temperature increases from 15 ℃ to 40 ℃, the amount of CH4 adsorption of Changcun and Zhaozhuang Coals decreases by 37.09% and 37.5%, respectively; coal samples When the particle size increases from 0.15 mm to 0.3 mm, the CH4 adsorption capacity decreases by 14.87% and 15.52%, respectively; the water content of the Changcun coal sample increases from 0.08% to 4.21%, the CH4 adsorption capacity decreases by 10.61%, and the water content of the Zhaozhuang coal sample decreases from Increased from 0.04% to 3.62%, the amount of CH4 adsorption decreased by 16.31%; the single factors of temperature, particle size, and water content all had a very significant impact on the amount of CH4 adsorption (P coal sample particle size (F=346.64)> water content (F=133.32); the degree of influence of each interaction item on the amount of CH4 adsorption is: particle size and water content (F=21.31)> temperature And particle size (F=6.33)>temperature and water content (F=3.65), the interaction between particle size and water content is extremely significant (P=0.002 4), and the interaction between temperature and coal sample particle size is significant (P=0.040 1). The interaction with water cut is not significant (P=0.097 8); the maximum deviation between the test value and the model prediction value outside the coding interval is 3.98%, the minimum is 2.01%, and the average error rate is 3.315%; during downhole recovery, temperature and water cut when the coal sample particle size and other factors change, firstly monitor the temperature change in real time to prevent the sudden change in temperature from causing a large amount of gas desorption, leading to excessive gas limit and even coal and gas outburst accidents