Migration Problem Research Articles

Deep-unrolling architecture for image-domain least-squares migration

Deep-image prior (DIP) is a novel approach to solving ill-posed inverse problems whose solution is parameterized with an untrained deep neural network and cascaded with the forward modeling operator. A key component to the success of such a method is represented by the choice of the network architecture, which must act as a natural prior to the inverse problem at hand and provide a strong inductive bias toward the desired solution. Inspired by the close link between neural networks and iterative algorithms in classical optimization, we apply an unrolled version of the gradient descent (GD) algorithm as our DIP network architecture, denoted as the deep-unrolling (DU) architecture. Each layer of the unrolled network is comprised of two parts: the first part corresponds to the GD step of the data-fidelity term, whereas the second part, formed by a six-layer convolutional neural network (CNN), plays the role of a regularizer in the associated objective function. The developed DU architecture is applied to the problem of image-domain least-squares migration (IDLSM) to invert migrated seismic images for their underlying reflectivity and is denoted as DU-IDLSM. As such, the DU architecture parameterizes the reflectivity, and the input of each layer of the unrolled network is the reflectivity at the previous layer. Similar to the classical DIP approach, the parameters of the DU architecture are optimized in an unsupervised fashion by minimizing the data misfit function itself. Through experiments with a part of the Sigsbee2A model and a marine field data set, we test the effectiveness of the DU-IDLSM approach and highlight two key benefits. First, the DU architecture can effectively regularize the inversion process, resulting in reflectivity estimates with fewer artifacts and higher image resolution than those produced by conventional IDLSM approaches. Second, we indicate that by including dropout layers in the CNN architecture, DU-IDLSM can produce a qualitative measure of the uncertainty associated with the least-squares migration process.

“Etudes About Tel Aviv”: The Image of Tel Aviv from the Perspective of Russian-Speaking Repatriates

The article offers an analysis of the collection Ėtiudy o Telʹ-Avive [Etudes about Tel Aviv], which was published in Russian in 2004 and edited by Sonia Chesnina and Leonid Finkelʹ. The study attempts to show the image of the city of Tel Aviv from the perspective of Russian-speaking repatriates. The author treats the analysed texts as non-fiction prose, expressing authentic migration experiences and problems. In those texts, Tel Aviv exists as a city-myth, a city of culture, and a place where a new identity is born and shaped. The analysis allows us to conclude that Etudes about Tel Aviv is not only a text about urban space. It is primarily a cultural text, a place of literary search for knowledge about its inhabitants’ culture, history, and identity. If we look at the relationship between geography and literature, the text (Etudes about Tel Aviv) and the city (Tel Aviv) constitute a “common territory”.

Незаконная миграция: причины, последствия и пути преодоления

There are many people in the world who are looking for a better life and move to other countries in search of work, education or better living conditions. However, not everyone is able to move legally, so there is the phenomenon of illegal migration. In this article we look at the causes, consequences and ways to overcome irregular migration. It also examines the current problems of irregular migration in the modern world. The paper analyses the main reasons for illegal migration, such as economic difficulties, political instability, refugees, etc. The consequences of irregular migration for the receiving countries and for the migrants themselves are discussed. The article also presents ways to overcome the problem of irregular migration, such as tightening the legislation, improving the skills of the services dealing with migration control, creating conditions for legal migration. Overall, the article provides a comprehensive overview of the problem of irregular migration and suggests ways to address it.

Homogeneous mono-layer mixed-halide perovskite quantum dots towards blue light-emitting diodes with stable spectra under continuous driving

Mixed-halide perovskite quantum dots (QDs) light-emitting diodes (QLEDs) with blue emission still suffer from low efficiency due to surface defects and halide migration. The issue of halide migration in the mixed-halide perovskite QLEDs under increasing biases have been basically solved. However, under continuous driving, the QLEDs still face the problem of halide migration or electroluminescence (EL) peak shift. In this work, we found that when ligand passivation effects on mixed-halide perovskite QDs are similar, the homogeneity of a mono-layer QDs film plays a decisive role in suppressing halide migration and improving the EL spectral stability of the QLEDs under continuous driving. Moreover, 4 and 64 mm2 QLEDs with emission peaks from pure-blue to deep-blue and low efficiency roll-off were fabricated and the analysis results show that factors, such as chlorine content or defects in the QDs, driving bias, operation time at the driving bias and current density, also matter in the EL spectral stability of the QLEDs. In addition, we found that the devices exhibit similar performance after being stored for a year, demonstrating high stability of the devices with homogeneous mono-layer QDs structure. Our work provides a timely and systematic guide on achieving spectrally stable and efficient blue QLEDs with high color purity based on mixed-halide perovskite QDs.

Проблемы национального законодательства в сфере регулирования миграционных отношений в Российской Федерации

The article discusses some problems of legal regulation of migration problems, as well as ways to solve them. As a result of the conducted research, the author comes to the conclusion that in order to further improve the migration legislation, it is objectively necessary to conduct scientific research on the problems and prospects of its development, including through systematization. At the same time, these studies should be interdisciplinary in nature, which is due to the multidimensional genesis of the current problems. Accordingly, the development of legal migration policy strategies should be strictly scientifically based.

Ewolucja pojęcia odporności społecznej wskutek doświadczeń pandemii COVID-19 i kryzysu imigracyjnego

Odporność społeczna (social resilience) cieszy się coraz większym zainteresowaniem badaczy, ponieważ pozwala przygotować społeczeństwo do wielu, różnego rodzaju sytuacji kryzysowych. Począwszy od zagrożeń ekologicznych i katastrof naturalnych poprzez zagrożenia ekonomiczne i zdrowotne, aż po zagrożenia występujące w trakcie konfliktu zbrojnego. Niestety pojęcie odporności społecznej (OS) wciąż pozostaje niejednorodne, a jego definicje nie zawsze są spójne z intencjami twórców koncepcji OS. Celem artykułu jest przegląd obecnych w literaturze definicji oraz wskazanie w jaki sposób współcześnie publikujący badacze definiują OS. Środkiem do realizacji jest przegląd definicji OS z ostatnich pięciu lat (2019-2023), z czasopism zindeksowanych w bazie Scopus. Przegląd ten pozwala pokazać ewolucję pojęcia OS, która jest efektem doświadczeń pandemii COVID-19, problemów migracyjnych oraz napaści zbrojnej Rosji na Ukrainę.

Conceptualization of the Problem of Climate Migration

Conceptualization of the Problem of Climate Migration

IRREGULAR MIGRANTS ON THE ROADS OF SERBIA

With the onset of the migrant crisis in Europe, irregular migration is becoming a significant security problem for European leaders and citizens. As a result, there has also been a change in the public opinion of European countries, because many citizens associate irregular migration with terrorism and other security problems. In line with the growing importance of irregular migration as a security problem, the research aimed to determine changes in migration trends in Serbia, that is, on the ‘Balkan route’ of migration since 2015, when the migrant crisis in Europe began. Results that can roughly indicate the profile of an irregular migrant found on the territory of the Republic of Serbia were obtained in this research, conducted between June and August 2020 on a sample of 50 irregular migrants. An irregular migrant is a person from Afghanistan, of Islamic religion, uneducated, and of a poor financial status. They want to go to Germany for money, and they cross the borders of the countries located on the ‘Balkan route’ on foot, occasionally using the services of smugglers. Additionally, they have no problems with the border police of Serbia. The conducted research can contribute to gaining new knowledge about the problem of irregular migration, primarily about the trends that are different than they were at the time of the migrant crisis in 2015. Unlike previous research, this research is unique in that it also refers to the work of the border police and the attitude of border police officers toward irregular migrants.

Approximate solution to the photon migration problem in a turbid medium based on the path-integral approach

The functions characterizing the directional and spatial distribution of photons propagating through an infinite scattering medium can be expressed in the form of specific path-integrals. However, these are not solvable analytically and have to be approximated by a more suitable form, while we require the preservation of only a few relaxed constraints imposed on the photon transport. The path integral solutions, i.e. the sought distribution functions, are found in the form of simple closed-form expressions. They are compared with the standard diffusion solution and with the second-order cumulant approximation, which solves an equivalent problem. Photon path length profiles of the distribution functions obtained by the path-integral approximation and the cumulant approximation are almost identical, but the first formulae are much simpler. The numerical examples indicate that the path-integral solution could serve as an improvement of the diffusion equation solution under appropriate conditions.

Hybrid learning based service migration for cost minimization with deadlines in multi-user mobile edge computing systems

Mobile edge computing, a new computing model, aims to reduce network latency and improve user experience by placing computing resources closer to the users. However, when users move away from the current service areas, the quality of services will decline. To guarantee the quality of services, service migration technique is proposed and studied. Due to the wireless resource contention among users, there is service migration decision-making coupling among multiple users. Meanwhile, making real-time service migration decisions for multiple users to minimize service cost with application deadlines remains an open challenge because of the huge state space. In this paper, we formalize the service migration problem with deadlines as a Markov decision process (MDP) and propose a hybrid learning based service migration strategy. The proposed approach integrates Monte Carlo method and DQN learning, which adopts online training without Q-values and neural network approximation to generate service migration decisions for multiple users. Experimental results demonstrate that the proposed hybrid learning based service migration strategy outperforms the existing migration strategies in terms of service success ratio and service cost.

On the Term “Environmental Refugee”: Normative Assumptions and Empirical Realities

Activist groups debate the complex connection between climate change and migration but generally agree on the normative value of describing those migrants as “environmental refugees.” They argue that using such a term, even though unrecognized under international law, might increase the urgency of this issue in the eyes of the public. Does the term do the normative work that has been assumed? To our knowledge, the idea has not been subject to empirical confirmation. In this research note, we present data from two experimental surveys conducted in the UK and the Netherlands (N = 2261) directly addressing that question. The findings significantly undermine the assumption that “environmental refugee” is normatively persuasive outside activists and academic circles. We demonstrate that using “environmental refugees” frames compared to “environmental migrants” does not increase the urgency of the climate migration problem in the eyes of the public, and as our results show, such frames may slightly lower perceptions of urgency. Yet, this result is rather negligible.

Cost-Efficient Cluster Migration of VNFs for Service Function Chain Embedding

Network Function Virtualization (NFV) is a network architecture that separates network functions from dedicated hardware, implementing them as software modules known as Virtual Network Functions (VNFs), which are executed in virtual machines or containers. NFV increases the deployment flexibility and agility within operator networks and reduces the operating and capital expenditures significantly. In NFV, migration of VNFs can significantly reduce the embedding cost. However, stringent latency requirements between VNFs can make them tightly coupled, thus hindering each VNF from being migrated individually, and resulting in poor performance. One of the main challenges in an NFV environment is therefore to migrate a cluster of VNFs to minimize the embedding cost. In this paper, we aim to solve the problem of cluster VNF migration by considering the given inter-VNF latency requirements. We formulate the VNF migration problem as an Integer Linear Programming (ILP) and present two scalable and efficient algorithms for migrating a cluster of VNFs. Through extensive experiments, we show that our proposed algorithms are highly effective. They reduce the total embedding cost by 14% compared to the existing heuristics, while being much more scalable in terms of execution time compared to the brute-force approach.

Environmental migration: a new challenge for the global community

The subject of the research in this article is the impact of environmental migration on humanity and its significance for the world community. The object of research in this article can be considered the study of the process of environmental migration and its impact on social development. The article aims to identify trends in the development of environmental migration, its impact on the future of mankind and its significance for the entire world community. The article comprehensively applied scientific research methods: methods of conceptual, institutional, historical analysis, as well as elements of a scenario approach. The novelty of the study lies in the fact that in recent decades attention to the problem of environmental migration has been increasing, which emphasizes the relevance of conducting research and a comprehensive analysis of this phenomenon. The article provides basic statistical data on the level of migration, analyzes the very concept of "environmental migration", identifies the main causes, trends and impact of environmental migration on the spheres of society. The research hypothesis about the need to form a unified theoretical basis for the concept of "ecological migration" was confirmed in the paper. The findings suggest that environmental migration is a serious challenge for the modern world, requiring a comprehensive approach and specific measures to manage this process. Trends in the development of environmental migration point to the need to develop sustainable strategies for migration management and adaptation to the changing world situation. At the same time, environmental migration offers opportunities for intensifying sustainable development measures and programmes, as the phenomenon itself requires theoretical and managerial rethinking, management and/or adaptation to its consequences.

A Three-Stage Optimal Operation Strategy of Interconnected Microgrids With Rule-Based Deep Deterministic Policy Gradient Algorithm.

The ever-increasing requirements of demand response dynamics, competition among different stakeholders, and information privacy protection intensify the challenge of the optimal operation of microgrids. To tackle the above problems, this article proposes a three-stage optimization strategy with a deep reinforcement learning (DRL)-based distributed privacy optimization. In the upper layer of the model, the rule-based deep deterministic policy gradient (DDPG) algorithm is proposed to optimize the load migration problem with demand response, which enhances dynamic characteristics with the interaction between electricity prices and consumer behavior. Due to the competition among different stakeholders and the information privacy requirement in the middle layer of the model, a potential game-based distributed privacy optimization algorithm is improved to seek Nash equilibriums (NEs) with encoded exchange information by a distributed privacy-preserving optimization algorithm, which can ensure the convergence as well as protect privacy information of each stakeholder. In the lower layer of the model of each stakeholder, economic cost and emission rate are both taken as operation objectives, and a gradient descent-based multiobjective optimization method is employed to approach this objective. The simulation results confirm that the proposed three-stage optimization strategy can be a viable and efficient way for the optimal operation of microgrids.

The Problem of Migration from Sub-Saharan Africa to Algeria in the Twenty-First Century

In the twenty-first century, there was a sharp increase in migration from sub-Saharan Africa to Algeria, and the Sahel zone became a hot stop for illegal human smuggling. Some immigrants go to the north of the country to continue their journey to Europe; others remain in Algeria, treating it as a destination country and do not continue their journey. Algeria has been repeatedly accused of using illegal practices against migrants, such as deportations, pushbacks, and detentions. The aim of the article is to try to assess the scale of the problem of illegal immigration in Algeria based on available statistical data and their periodisation. The main routes taken by migrants will be described, as well as the basic principles of migration policy in Algeria. The following hypotheses were put forward: 1) Algeria is mainly a transit country for migrants from sub-Saharan Africa; 2) The main irregular migration routes lead from the Sahel zone; 3) There is unequal treatment of people in terms of violations of Algerian law (division into Algerians and others). For the purposes of the article, the following research methods were used – analysis and synthesis, comparative method, statistical method, and systemic approach.

Russian Ethnic Groups in the National Structure of Belarus

Based on statistical data and materials of the All-Union population censuses of 1959-1989, as well as national population censuses of the Republic of Belarus in 1999-2019. the development trends of ethnic processes in Belarus are analyzed. The characteristic of the ethnic structure of modern Belarusian society is given. An excursion into the history of the Russian ethnic group and the indigenous peoples of Russia in the Belarusian lands was made. The role and place of the Russian ethnos in the post-war period of Belarus is shown. The role of migration in ethnic processes is considered. An important place is given to the analysis of the push migration of the Russian-speaking population in the national republics of the period of the collapse of the unified demographic space of the USSR. An analysis of the features and problems of the Belarusian-Russian migration is given. The characteristic of individual indigenous Russian peoples in the national structure of Belarus is given. The ethnic ties of the border regions of Belarus and Russia are highlighted. The changes of the Belarusian ethnos in the national structure of the Russian Federation are reflected.

Identity digitalization as dispossession and entrenched displacement: digitalization at the nexus of migration “management” and climate change in Thailand and Türkiye

Digitalizing technologies are increasingly heralded by a range of powerful actors and some human rights organizations as appropriate and necessary tools for ‘managing migration’ and mitigating climate change. Yet, just as exclusionary and marginalizing discourses of “migration problems” serve to justify the digital surveillance of vulnerable and precariously statused people, the context of climate change, accelerating contestation over land and water, and discourses of catastrophe prove fertile ground for entrenching these practices and technologies in multiple ways. Researchers are identifying the dispossessive power of digitalization in the arena of personal identification and in relation to resource and land mapping, yet these dynamics are rarely interrogated in connection. In this comparative analysis, we draw from sustained ethnographic engagement and insights in critical digitalization studies and political economy to analyze the consequences of state efforts to digitalize identity and resources in Thailand and Türkiye in the age of the Anthropocene. Our research points to a need for greater attention to the ways that state efforts to digitalize identification and registration of immigrant, refugee, and stateless people link with, and can facilitate, more efficient dispossessions and displacements of precariously statused communities from vital and contested lands.

Organizational and legal regulation of labor migration in the Kyrgyz Republic

This article discusses the problems of internal migration, territorial population movements, the need for legal regulation and management of migration flows. To reduce the outflow of population from rural areas to cities and the most industrially developed regions. The problems of unregulated labor migration and prospects for coordinating the activities of the state are also considered.

GEOGRAPHY OF MIGRATIONS IN POPULATION OF UKRAINE: CONSEQUENCES OF RUSSIAN AGGRESSION

Population migrations (causes, regions of departure/arrival, directions, scope, intensity, and consequences) are predefined by economic, social, political, inter-confessional, interethnic, ecological and other factors. Problems of migration in Ukraine have become specifically painful under the conditions of russia’s war aggression and its invasion of the sovereign state of Ukraine in 2014. It was in the pre-war peaceful period (2006–2013) that migration flows in Ukraine became stable both quantitatively and in aspects of their major directions. The majority of regions (25 of 27) showed a positive interstate balance of population. Interregional migrants were attracted by 7 regions (City of Kyiv and Kyiv Oblast, Kharkiv Oblast, Odesa Oblast, City of Sevastopol, Autonomous Republic of Crimea, and Chernivtsi Oblast), while 20 regions had a negative balance of this type of migration. In the conditions of russia’s hybrid war against Ukraine (2014–2021), the interstate migration balance was still positive, but its volume was down by 30% (with no figures available for the temporarily occupied territories). The disproportion between the figures of interregional migration available for oblasts grew (in comparison to the pre-war period) 1,6 times. The Kyiv Oblast and the City of Kyiv, together with the Kharkiv, Odesa, Dnipropetrovsk, Lviv and Ivano-Frankivsk oblasts, have become the most attractive localities for migrants from other Ukrainian regions. Significant growth was observed in interregional migrants who departed from the localities of direct combat activity (Donetsk, Luhansk, Zaporizzia, and Kherson oblasts). A new category of forced migrants—internally displaced persons—appeared. The russia’s full-scale war against Ukraine (beginning on February 24, 2022) has resulted in the occurrence of substantial forced migration flows. The war has brought an increase in the number of refugees, internally displaced persons, temporarily protected persons (when abroad), forcibly transferred persons (to Russia), etc. The directions and the scale of migration flows depend on the geography of the hostilities. Spatial specificities of interstate and interregional migrations in the population of Ukraine are defined for the prewar period, the period of russia’s hybrid war against Ukraine (2014–2021), and the full-scale russian-Ukrainian war (beginning on February 24, 2022). The scope and the directions of migrant departures/arrivals are disclosed, as well as their effect on the dynamics of population number in Ukraine and its regions.

Миграция из России на фоне мобилизации и ее влияниена социально-экономическую ситуацию в странах Центральной Азии

In the context of the aggravation of the geopolitical situation, migration processes in the post-Soviet space are moving into a state of turbulence, which has a serious impact on the socio-economic development of the countries of Central Asia. In this regard, the urgency of the migration problem is increasing, which creates risks of deterioration in the state of the labor market, interethnic relations and the development of the shadow economy. As research methods, content analysis and a systematic method were chosen to identify the relationship between political events and migration. Thus, this study will adequately highlight the migration problem against the background of geopolitical turbulence in Central Asia in modern regional studies and analyze its “side” effects on the state of the socio-economic system. At the same time, the study is aimed at developing practical recommendations in the field of regulating the migration processes in the framework of modernizing the migration policy of the countries of Central Asia.