Problems In Media Research Articles

An Effective Discontinuous Galerkin Method for Solving Acoustic Wave Equations in Heterogeneous Media

Abstract A discontinuous Galerkin (DG) method is introduced for solving 2D and 3D first-order velocity-pressure acoustic wave propagation problems in heterogeneous media. First, acoustic equations are reformulated into a first-order hyperbolic system, which can be integrated into the framework of the DG method. Then, we introduce an effective numerical flux in DG spatial discretization, which preserves physical laws on both sides of interfaces with discontinuous material parameters. It is compared with both the classic Lax-Friedrichs flux and the exact upwind flux, with the latter derived from solving the Riemann problem and satisfying the Rankine-Hugoniot condition. The comparison reveals that while our flux is formally similar to the classic local Lax-Friedrichs flux, its numerical behavior is analogous to the exact upwind flux. The primary advantage of this method lies in its simplicity and straightforward computation yet can maintain physical continuity conditions near interfaces with discontinuous material parameters. Several numerical experiments of acoustic wave propagation in 2D and 3D heterogeneous media are carried out, illustrating the effectiveness of this method.

Determination of the modified exterior Steklov eigenvalues via the reciprocity gap method

The modified exterior Steklov eigenvalues (MESEs) arise from the inverse scattering problem for inhomogeneous media with a cavity and may serve as potential target signatures in nondestructive testing. In this paper we are interested in the determination of the MESEs from the measured Cauchy data of the total field on some manifold inside the cavity due to interior point sources. To this end, the reciprocity gap (RG) method based on a linear integral equation is employed. We provide the related theory and show that the blow-up property of the approximate solution to the integral equation can be used to characterize the MESEs. Numerical examples are presented to demonstrate the viability of our method.

Numerical Method for the Variable-Order Fractional Filtration Equation in Heterogeneous Media

This paper presents a study of the application of the finite element method for solving a fractional differential filtration problem in heterogeneous fractured porous media with variable orders of fractional derivatives. A numerical method for the initial-boundary value problem was constructed, and a theoretical study of the stability and convergence of the method was carried out using the method of a priori estimates. The results were confirmed through a comparative analysis of the empirical and theoretical orders of convergence based on computational experiments. Furthermore, we analyzed the effect of variable-order functions of fractional derivatives on the process of fluid flow in a heterogeneous medium, presenting new practical results in the field of modeling the fluid flow in complex media. This work is an important contribution to the numerical modeling of filtration in porous media with variable orders of fractional derivatives and may be useful for specialists in the field of hydrogeology, the oil and gas industry, and other related fields.

An Analysis of the Dilemma of Developing Media Literacy Education in China

Though media literacy education appeared as an independent discipline in some developed countries in the 20th century, it has only just begun in China in the 21st century. Nowadays, with the advancement of the Internet and science and technology, media literacy education has emerged as a prominent issue of global concern. As such, the rapid economic and scientific development of China, the largest developing country, has led to increasing demands for media literacy. Therefore, the paper presents an analysis of pertinent studies on efficacious media literacy education programs in developed countries, including the United Kingdom, the United States, and Canada, and compares the current situation of media literacy education in China in terms of educational policies, schools, and social practices. In addition, it also points out the dilemmas facing the development of media literacy education in China, including the rapid updating of technology and platforms, the lack of selection and evaluation of media content, social inequality, and the digital divide. China should actively learn from the international advanced cases of media literacy education, so as to make Chinas media education better adapt to the information age of the 21st century, strive to solve the current media problems as soon as possible, and explore a localized road of media literacy education.

Meningkatkan Hasil Belajar PAK Melalui Media Canva dalam Problem Based Learning Kelas IX SMP Negeri 1 Wonosari

There are still students of SMP Negeri 1 Wonosari, who have not fulfilled the expectations of the school's vision and mission which is to create people who believe and fear God Almighty, have noble character, are healthy, knowledgeable, capable, creative, independent, and become democratic and responsible citizens. This is evident in the fact that there are still students whose learning outcomes are low. To improve PAK learning outcomes, we tried using canva media in Problem Based Learning. To answer this problem, the researcher used an experimental method with 2 cycles using test and observation instruments. With research using qualitative descriptive data analysis methods. Based on the data obtained, the percentage of student learning outcomes in cycle I is 22% decent, 56% proficient and 22% advanced, which shows that there are still 2 children who need remedial. In cycle II, with canva media, learning outcomes increased to 0% feasible, 11% proficient and 89% advanced. This shows Problem Based Learning can improve critical thinking and learning outcomes.

A fast time-discontinuous peridynamic method for stress wave propagation problems in saturated porous media

A fast time-discontinuous peridynamic method for stress wave propagation problems in saturated porous media

Factors of the growing role of mass communication as a tool for shaping political consciousness in the modern world

The article is dedicated to the study of the factors contributing to the increasing influence of mass media on the formation of political consciousness in modern society. In the context of globalization and digitalization, mass media have become key instruments in shaping public opinion, political preferences, and mobilizing various forms of socio-political activity. The paper analyzes the key technological, sociocultural, political, and economic factors that directly or indirectly determine the influence of mass media on political processes and societal consciousness. Special attention is given to the role of algorithms in the selection and presentation of information, including the impact of external factors on content, as well as challenges related to the spread of disinformation and manipulative technologies. The article also explores the phenomenon of the mediatization of politics and the self-referential nature of mass media, which contribute to the formation of a specific public space and changes in political communication. The problems of global media influence, which tend to unify information flows and blur cultural and political differences between countries, are also analyzed. The conclusions emphasize the importance of ensuring transparency, independence, and diversity of mass media to support democratic processes, strengthen civil society, and prevent information manipulation in the modern world.

Non-Intrusive Reduced Basis two-grid method for flow and transport problems in heterogeneous porous media

Due to its non-intrusive nature and ease of implementation, the Non-Intrusive Reduced Basis (NIRB) two-grid method has gained significant popularity in numerical computational fluid dynamics simulations. The efficiency of the NIRB method hinges on separating the procedure into offline and online stages. In the offline stage, a set of high-fidelity computations is performed to construct the reduced basis functions, which is time-consuming but is only executed once. In contrast, the online stage adapts a coarse-grid model to retrieve the expansion coefficients of the reduced basis functions. Thus it is much less costly than directly solving a high-fidelity model. However, coarse grids in heterogeneous porous media of flow models are often accompanied by upscaled hydraulic parameters (e.g. hydraulic conductivity), thus introducing upscaling errors. In this work, we introduce the two-scale idea to the existing NIRB two-grid method: when dealing with coarse-grid models, we also employ upscaled model parameters. Both the discretization and upscaling errors are compensated by the rectification post-processing. The numerical examples involve flow and heat transport problems in heterogeneous hydraulic conductivity fields, which are generated by self-affine random fields. Our research findings indicate that the modified NIRB method can effectively capture the large-scale features of numerical solutions, including pressure, velocity, and temperature. However, accurately retrieving velocity fields with small-scale features remains highly challenging.

Simulation of hydro-deformation coupling problem in unsaturated porous media using exponential SWCC and hybrid improved iteration method with multigrid and multistep preconditioner

Simulation of hydro-deformation coupling problem in unsaturated porous media using exponential SWCC and hybrid improved iteration method with multigrid and multistep preconditioner

Increasing stability of the acoustic and elastic inverse source problems in multi-layered media

Abstract This paper investigates inverse source problems for the Helmholtz and Navier equations in multi-layered media, considering both two and three-dimensional cases respectively. The study reveals a consistent increase in stability for each scenario, characterized by two main terms: a Hölder-type term associated with data discrepancy, and a logarithmic-type term that diminishes as more frequencies are considered. In the two-dimensional case, measurements on interfaces and far-field data are essential. By employing the fundamental solution in free-space as the test function and utilizing the asymptotic behavior of the solution and continuation principle, stability results are obtained. In the three-dimensional case, measurements on interfaces and artificial boundaries are taken, and the stability result can be derived by applying the arguments for inverse source problems in homogeneous media.

Alternative Media: Free from State, Market, and Capital(ism)? On the Antagonisms of Alternative Media and the Alternative Economy

This work discusses the potentials, limits, and problems of alternative media in capitalism. It compares alternative media to commercial media and public service media. A model is introduced that compares commercial and non-commercial media projects. Its dimensions are the economy, work, production, and communication. Dilemmas of alternative media are analysed. As an example, a conflict at the Austrian free radio station Radio Orange is analysed. The paper discusses the political economy of alternative media. Alternative media such as free radio stations have set out to do media in a way that is different to capitalist media. In this context, the role of the audience as media producers and the rejection of the market, capital, and commodities are important aspects of alternative media. The analysis shows the problems and antagonisms that non-commercial, alternative media face in capitalist society. They struggle to establish independence from markets, capital, and the state. They face the problem of how to deal with these antagonisms which results in the alternative between adopting to capitalist pressures or operating as small-scale niche alternatives with small audiences and precarious labour. The paper concludes that material aspects and the political economy of alternative media need to be taken seriously. Not selling commodities and not paying wages puts many alternative media at a disadvantage vis-à-vis commercial media.

Detecting and Grounding Multi-Modal Media Manipulation and Beyond.

Misinformation has become a pressing issue. Fake media, in both visual and textual forms, is widespread on the web. While various DeepFake detection and text fake news detection methods have been proposed, they are only designed for single-modality forgery based on binary classification, let alone analyzing and reasoning subtle forgery traces across different modalities. In this paper, we highlight a new research problem for multi-modal fake media, namely Detecting and Grounding Multi-Modal Media Manipulation (DGM 4). DGM 4 aims to not only detect the authenticity of multi-modal media, but also ground the manipulated content (i.e., image bounding boxes and text tokens), which requires deeper reasoning of multi-modal media manipulation. To support a large-scale investigation, we construct the first DGM 4 dataset, where image-text pairs are manipulated by various approaches, with rich annotation of diverse manipulations. Moreover, we propose a novel HierArchical Multi-modal Manipulation rEasoning tRansformer (HAMMER) to fully capture the fine-grained interaction between different modalities. HAMMER performs: 1) manipulation-aware contrastive learning between two uni-modal encoders as shallow manipulation reasoning and 2) modality-aware cross-attention by multi-modal aggregator as deep manipulation reasoning. Dedicated manipulation detection and grounding heads are integrated from shallow to deep levels based on the interacted multi-modal information. To exploit more fine-grained contrastive learning for cross-modal semantic alignment, we further integrate Manipulation-Aware Contrastive Loss with Local View and construct a more advanced model HAMMER++. Finally, we build an extensive benchmark and set up rigorous evaluation metrics for this new research problem. Comprehensive experiments demonstrate the superiority of HAMMER and HAMMER++; several valuable observations are also revealed to facilitate future research in multi-modal media manipulation.

Deconstructing Islamic Cyberculture: Mitigating Inferiority and Cancel Culture in Virtual Space

This article aims to explore the values of Islamic Cyberculture in mitigating inferiority and cancel culture in virtual spaces. The phenomenon of cancel culture and inferiority is an interesting issue. In Indonesia, this issue has affected people's personal lives, from rejection to petitions. This is certainly legitimate because there are no regulations governing the criminal offence of cancel culture. However, psychologically, it is found that this culture arises because of the inferiority of individuals so that they make destructive movements. The urgency of this research is to rebuild Islamic Cyberculture in overcoming problems in social media. This article uses a qualitative method with a case study approach. Primary data in this research are case examples and articles that are reviewed using literature review techniques. After the data is collected, the author will analyse the data using content analysis techniques. The results show that there are at least four components of Islamic Cyberculture in the Qur'an, namely: Principles of Justice and Equality, Ethics of Speaking and Interacting, Importance of Knowledge and Reflection and Avoiding Fitnah and Ghibah. Field facts show that there are at least five urgent challenges regarding inferiority and cancel culture in Indonesia, namely: 1) Social Pressure and Unrealistic Expectations, 2) Cancel Culture and Quick Judgement, 3) Self-Censorship and Restrictions on Freedom of Expression, 4) Polarisation and Lack of Constructive Dialogue and 5) Use of Technology for Character Destruction. All of these problems can be minimised by Islamic Cyberculture that continues to voice positive messages, build awareness of digital ethics, and educate the public. Islamic Cyberculture brings a grand narrative in restoring a more inclusive and wise virtual environment.

Development and Evaluation of a Digital Pop-Up Book on the Concept of Force for Fourth-Grade Science

Preliminary research, through observations, questionnaires, and interviews, showed problems in fourth-grade science learning media about force. This research aimed to develop a digital pop-up book on the concept of force This research used the research and development (RnD) method. The stages of the research were finding potential problems, data collection, product design, design validation, design improvements, product test, product revision, usage test, product revision, and mass production. Media experts validated the pop-up book and assessed it in a category of qualified with a score of 89.50%, meaning that the media emphasized information accordingly to the target; the choice of font and size was correct; the media was attractive, easy to use, made it easier for students to understand the material, and made it easier for teachers to deliver the lesson. The content expert validated the content on force and assessed the accuracy of the content in the category of very suitable with a score of 91.25%, which means that the material was presented coherently, encouraged students’ curiosity, was appropriate to support the lesson, activating students, increased students’ knowledge, had clear visuals and text, had concise and clear language, and delivered suitable language level. The effectiveness of digital pop-up books in improving students’ understanding of the material was shown in the t-test result (13.513) and an average increase (N-gain) of pretest and post-test data of 0.55 with medium criteria. Participants’ questionnaire showed their opinions on the excellent quality of digital pop-up books. This research indicated that digital pop-up books on the concept of force met the media and content qualification criteria, which motivated and helped the students comprehend the information.

Multiscale model reduction for the time fractional thermoporoelasticity problem in fractured and heterogeneous media

In this paper, we consider the time fractional thermoporoelasticity problem in fractured and heterogeneous media. The mathematical model with a time memory formalism is described by a coupled system of equations for pressure, temperature and displacements. We use an implicit finite difference approximation for temporal discretization. We present a fine grid approximation based on the finite element method and Discrete Fracture Model (DFM) for two-dimensional model problems. Further, we use the Generalized Multiscale Finite Element Method (GMsFEM) for coarse grid approximation. The primary concept behind the proposed method is to streamline the complexity inherent in the thermoporoelasticity problem. Given that our model equation incorporates multiple fractional powers, leading to multiple unknowns with memory effects, we aim to address this intricacy by optimizing the problem’s dimensionality. As a result, the solution is sought on a coarse grid, a strategic choice that not only simplifies the computational cost but also contributes to significant time savings. We present numerical results for the two-dimensional model problems in heterogeneous fractured porous media. We derive relative errors between the reference fine grid solution and the multiscale solution for different numbers of multiscale basis functions. The results confirm that the proposed method is able to achieve good accuracy with a few degrees of freedoms on the coarse grid.

Kajian Literatur Penggunaan Media Pembelajaran pada Mata Pelajaran Bahasa Indonesia Berbasis PBL

This article review aims to collect and review articles that discuss the use of learning media in Problem Based Learning (PBL) based Indonesian language subjects. The research method used is descriptive qualitative with a literature review approach to articles in the last 10 years and obtained 10 articles that meet the requirements. Data collection was done through a literature review of previous articles related to the research. The findings obtained in this study indicate that there are a number of learning media that can be used in Problem Based Learning (PBL) based Indonesian language subjects, namely serialized picture media, wordwall media, animated video media, booklet media, comic media, spinning wheel media, and audio visual media. The conclusion that can be drawn is that these learning media are feasible to use to convey learning materials easily in Problem Based Learning (PBL) based Indonesian language subjects.

A deep learning approach for solving the stationary compositional two-phase equilibrium problems

In this paper, we propose and investigate a deep neural network approach for solving the stationary compositional two-phase equilibrium problems in porous media. A recent approach is the unified formulation advocated by Lauser et al. (2011) which contains the complementarity conditions. The advantage of this formulation lies in its potential to handle the appearance and disappearance of phases automatically. To solve numerically the system of equations, a new strategy called NPIPM (NonParametric Interior-Point Method) is proposed by Vu et al. (2021). However, the method still has some disadvantages preventing the convergence to a solution. Taking inspiration from the work of Raissi et al. (2019) for the study of nonlinear partial differential equations using Physics-Informed Neural Networks (PINN), we realize that we can apply a deep neural network to obtain the solution of the stationary compositional model containing gas and liquid. We design a deep neural network structure and define a new loss function for the problem. The effectiveness of the proposed method is validated through numerical results obtained from a series of systems with increasing components. This machine learning approach provides a promising idea to solve the curse of dimensionality issue in the sense of the increasing number of components in stationary problems.

Application of meshless generalized finite difference method (GFDM) in single-phase coupled heat and mass transfer problem in three-dimensional porous media

This paper achieves effective and precise meshless modeling of three-dimensional (3D) single-phase coupled heat and mass transfer problems based on the generalized finite difference method (GFDM). It utilizes the Taylor formula and the weighted least squares method in the node influence domains to derive a generalized finite difference scheme for spatial derivatives of pressure and temperature. Consequently, a sequential coupled discrete scheme for the pressure diffusion equation and heat convection–conduction equation is formulated, resulting in the determination of pressure and temperature. An example conducts sensitivity analysis with different schemes of node collocation and different radius of influence domains. The calculation results demonstrate that this method exhibits good convergence. Two 3D model examples with regular and irregular boundaries illustrate the advantages of the GFDM in handling complex geometric problems within the computational domain, showcasing its superior flexibility and simplicity. This paper demonstrates the significant potential of GFDM in addressing complex geometric multi-physics field coupling challenges, offering innovative ideas for geothermal resource development, groundwater management, and thermal recovery in oil and gas reservoirs.

Generalization of the Method of Scattering Matrices to Problems in Nonlinear Dispersion Media

Generalization of the Method of Scattering Matrices to Problems in Nonlinear Dispersion Media

Discrete energy balance equation via a symplectic second-order method for two-phase flow in porous media

We propose and analyze a second-order partitioned time-stepping method for a two-phase flow problem in porous media. The algorithm is a refactorization of Cauchy's one-leg θ-method: the implicit backward Euler method on [tn,tn+θ], and a linear extrapolation on [tn+θ,tn+1]. In the backward Euler step, the decoupled equations are solved iteratively, with the iterations converging linearly. In the absence of the chain rule for time-discrete setting, we approximate the change in the free energy by the product of a second-order accurate discrete gradient (chemical potential) and the one-step increment of the state variables. Similar to the continuous case, we also prove a discrete Helmholtz free energy balance equation, without numerical dissipation. In the numerical tests we compare this symplectic implicit midpoint method (θ=1/2) with the classic backward Euler method, and two implicit-explicit time-lagging schemes. The midpoint method outperforms the other schemes in terms of rates of convergence, long-time behavior and energy approximation, for both small and large values of the time step.