GUI testing is an essential quality assurance process in mobile app development. However, the creation and maintenance of GUI tests for mobile apps are resource-intensive and costly. Recognizing that many apps share similar functionalities, researchers have proposed various techniques to migrate GUI tests from one app to another with similar features. For example, some techniques employ mapping-based approaches to align the GUI elements traversed by the tests of a source app to those present in the target app. Other test migration techniques have also been proposed to leverage large language models (LLMs) by adapting the GUI tasks in source tests. However, these techniques are ineffective in dealing with different operational logic between the source and target apps. The semantics of GUI elements may not be correctly inferred due to the missing analysis of these flows. In this work, we propose REUSEDROID, a novel multiagent framework for GUI test migration empowered by Large Vision-Language Models (VLMs). REUSEDROID is powered by multiple VLM-based agents, each tackling a stage of the test migration process by leveraging the relevant visual and textual information embedded in GUI pages. An insight of REUSEDROID is to migrate tests based only on the core logic shared across similar apps, while their entire operational logic could differ. We evaluate REUSEDROID on LinPro, a new test migration dataset that consists of 578 migration tasks for 39 popular apps across 4 categories. The experimental result shows that REUSEDROID can successfully migrate 90.3% of the migration tasks, outperforming the best mapping-based and LLM-based baselines by 318.1% and 109.1%, respectively.
The paragraph is grammatically correct and logically coherent. It discusses the importance of mobile terminal cloud computing migration technology in meeting the demands of evolving computer and cloud computing technologies. It emphasizes the need for efficient data access and storage, as well as the utilization of cloud computing migration technology to prevent additional time delays. The paragraph also highlights the contributions of cloud computing migration technology to expanding cloud computing services. Additionally, it acknowledges the role of virtualization as a fundamental capability of cloud computing while emphasizing that cloud computing and virtualization are not inherently interconnected. Finally, it introduces machine learning-based virtual machine migration optimization and dynamic resource allocation as a critical research direction in cloud computing, citing the limitations of static rules or manual settings in traditional cloud computing environments. Overall, the paragraph effectively communicates the importance of machine learning technology in addressing resource allocation and virtual machine migration challenges in cloud computing.
As a cornerstone of blockchain technology in the 3.0 era, smart contracts play a pivotal role in the evolution of blockchain systems. In order to address the limitations of existing smart contract vulnerability detection models with regard to their generalisation capability, an AF-STip smart contract vulnerability detection framework incorporating efficient knowledge migration is proposed. AF-STip employs the teacher network as the main model and migrates the knowledge processed by the smart contract to the student model using a data-free knowledge distillation method. The student model utilises this knowledge to enhance its vulnerability detection capabilities. The approach markedly enhances the model's capacity for feature extraction and cross-class adaptation, while concurrently reducing computational overhead.In order to further enhance the extraction of vulnerability features, an adaptive fusion module is proposed in this paper, which aims to strengthen the interaction and fusion of feature information.The experimental results demonstrate that the STip model attains an average F1 value detection score of 91.16% for the four vulnerabilities without disclosing the original smart contract data. To validate the viability of the proposed lightweight migration approach, the student model is deployed in a migration learning task targeting a novel vulnerability type, resulting in an accuracy of 91.02% and an F1 score of 90.46%. To the best of our knowledge, AF-STip is the inaugural model to apply data-free knowledge migration to smart contract vulnerability detection. While markedly reducing the computational overhead, the method still demonstrates exceptional performance in detecting novel vulnerabilities.
Giulia Ceriotti, Sergey M. Borisov, Jasmine Berg
et al.
Anaerobic processes (e.g., methanogenesis and fermentation) largely contribute to element cycling and natural contaminant attenuation/mobilization, even in well-oxygenated porous environments, such as shallow aquifers. This paradox is commonly explained by the occurrence of small-scale anoxic microenvironments generated by the coupling of bacterial respiration and the heterogeneous oxygen (O2) transport by porewater. Such microenvironments allow facultatively and obligately anaerobic bacteria to proliferate in oxic environments. Microenvironment dynamics are still poorly understood due to the challenge of directly observing biomass and O2 distributions at the microscale within an opaque sediment and soil matrix. To overcome these limitations, we integrated a microfluidic device with transparent O2 planar optical sensors to measure the temporal behavior of dissolved O2 concentrations and biomass distributions with time-lapse video-microscopy. Our results reveal that bacterial colony morphology, which is highly variable in flowing porous systems, controls the formation of anoxic microenvironments. We rationalize our observations through a colony-scale Damkohler number comparing dissolved O2 diffusion and bacterial O2 uptake rate. Our Damkholer number enables predicting the pore space occupied by anoxic microenvironments in our system, and, given the bacterial organization, it can be applied to 3D porous systems.
V. S. Ramakrishna Annapareddy, Adnan Sufian, Thierry Bore
et al.
This study presents physical observations and insights into particle migration characteristics throughout the suffusion process. Using a purpose-built coaxial permeameter cell, suffusion experiments were conducted on idealised internally unstable gap-graded granular soils at varying fines content and hydraulic loading conditions. The specimens were prepared with a mixture layer comprising finer and coarser fractions underlying a coarse layer composed of the coarser fraction alone. This enabled the finer fraction within the mixture layer to migrate through the coarse layer with upward seepage flow. The local porosity profile along the specimen was determined using spatial time domain reflectometry and an inversion algorithm, which enabled the development of a novel field map of the difference in porosity from the initial condition. This field map provided a visual guide of the spatial and temporal variation in porosity and enabled particle migration internally within the specimen to be quantitatively characterised from onset to progression to washout. The limiting onset condition identified from the field map was shown to be comparable to that obtained using conventional approaches, thereby providing strong validation for the application of porosity-based field maps. As suffusion progressed, the height of infiltrating finer particles into the coarse layer increased linearly with time, while the overall rate of particle migration from the mixture layer to the coarse layer evolved in a non-linear manner with the rate of migration increasing as the specimen reached a complete mixture condition, where the finer fraction infiltrated the entire coarse layer. The attainment of a complete mixture condition was dependent on the fabric of the gap-graded soil ... (see PDF for full abstract).
It has been hypothesized that the most likely atomic rearrangement mechanism during grain boundary (GB) migration is the one that minimizes the lengths of atomic displacements in the dichromatic pattern. In this work, we recast the problem of atomic displacement minimization during GB migration as an optimal transport (OT) problem. Under the assumption of a small potential energy barrier for atomic rearrangement, the principle of stationary action applied to GB migration is reduced to the determination of the Wasserstein metric for two point sets. In order to test the minimum distance hypothesis, optimal displacement patterns predicted on the basis of a regularized OT based forward model are compared to molecular dynamics (MD) GB migration data for a variety of GB types and temperatures. Limits of applicability of the minimum distance hypothesis and interesting consequences of the OT formulation are discussed in the context of MD data analysis for twist GBs, general Σ3 twin boundaries and a tilt GB that exhibits shear coupling. The forward model may be used to predict atomic displacement patterns for arbitrary disconnection modes and a variety of metastable states, facilitating the analysis of multimodal GB migration data.
O. M. Guilera, M. M. Miller Bertolami, F. Masset
et al.
A key process in planet formation is the exchange of angular momentum between a growing planet and the protoplanetary disc, which makes the planet migrate through the disc. Several works show that in general low-mass and intermediate-mass planets migrate towards the central star, unless corotation torques become dominant. Recently, a new kind of torque, called the thermal torque, was proposed as a new source that can generate outward migration of low-mass planets. While the Lindblad and corotation torques depend mostly on the properties of the protoplanetary disc and on the planet mass, the thermal torque depends also on the luminosity of the planet, arising mainly from the accretion of solids. Thus, the accretion of solids plays an important role not only in the formation of the planet but also in its migration process. In a previous work, we evaluated the thermal torque effects on planetary growth and migration mainly in the planetesimal accretion paradigm. In this new work, we study the role of the thermal torque within the pebble accretion paradigm. Computations are carried out consistently in the framework of a global model of planet formation that includes disc evolution, dust growth and evolution, and pebble formation. We also incorporate updated prescriptions of the thermal torque derived from high resolution hydrodynamical simulations. Our simulations show that the thermal torque generates extended regions of outward migration in low viscosity discs. This has a significant impact in the formation of the planets.
Liquid migration in active soft solids is a very common phenomenon in Nature at different scales: from cells to leaves. It can be caused by mechanical as well as chemical actions. The work focuses on the migration of liquid provoked by remodeling processes in an active impermeable gel sphere. Within this context, we present a consistent mathematical theory capable to gain a deep understanding of the phenomenon in both steady and transient conditions.
Luiz Alberto DePaula, Tatiana Alexandrovna Michtchenko
FARGO3D has been proposed to investigate numerically the gravitational interaction of a planet with the gas disc, providing original outcomes. However, FARGO3D does not consider the gas accretion of the planet which may affect the planetary migration process. Thus, the aim of this paper is to include a model for the gas accretion in the FARGO3D code. For this task, we choose Russell's scheme, which is an adaptation of Kley's model for the gas accretion on to migrating planets. Initially, we study the influence of the gas accretion on to the planet on type II migration of giant planets. For this purpose, we follow the evolution of planets in a 2D locally isothermal disc with a specific accretion rate and different values of viscosity and planetary mass considering two scenarios. In the first, the gas mass is withdrawn from the disc and is not added to the planet. In the second, the planets migrate, while their masses grow due to the gas accretion. Then, we extend our study to estimate the time needed for a low-mass planet to open a gap in the gas disc and compare its value with the characteristic time of type I migration.
Cell migration in fibreous extracellular matrix (ECM) is crucial to many physiological and pathological processes such as tissue regeneration, immune response and cancer progression. During migration, individual cells can generate active pulling forces via actin filament contraction, which are transmitted to the ECM fibers through focal adhesion complexes, remodel the ECM, and eventually propagate to and can be sensed by other cells in the system. The microstructure and physical properties of the ECM can also significantly influence cell migration, e.g., via durotaxis and contact guidance. Here, we develop a computational model for cell migration regulated by cell-ECM micro-mechanical coupling. Our model explicitly takes into account a variety of cellular level processes including focal adhesion formation and disassembly, active traction force generation and cell locomotion due to actin filament contraction, transmission and propagation of tensile forces in the ECM, as well as the resulting ECM remodeling. We validate our model by accurately reproducing single-cell dynamics of MCF-10A breast cancer cells migrating on collagen gels and show that the durotaxis and contact guidance effects naturally arise as a consequence of the cell-ECM micro-mechanical interactions considered in the model. Moreover, our model predicts strongly correlated multi-cellular migration dynamics, which are resulted from the ECM-mediated mechanical coupling among the migrating cell and are subsequently verified in {\it in vitro} experiments using MCF-10A cells. Our computational model provides a robust tool to investigate emergent collective dynamics of multi-cellular systems in complex {\it in vivo} micro-environment and can be utilized to design {\it in vitro} micro-environments to guide collective behaviors and self-organization of cells.
Catalina-Paula Spatarelu, Hao Zhang, Dung Trung Nguyen
et al.
Cell migration is essential for regulating many biological processes in physiological or pathological conditions, including embryonic development and cancer invasion. In vitro and in silico studies suggest that collective cell migration is associated with some biomechanical particularities, such as restructuring of extracellular matrix, stress and force distribution profiles, and reorganization of cytoskeleton. Therefore, the phenomenon could be understood by an in-depth study of cells' behavior determinants, including but not limited to mechanical cues from the environment and from fellow travelers. This review article aims to cover the recent development of experimental and computational methods for studying the biomechanics of collective cell migration during cancer progression and invasion. We also summarized the tested hypotheses regarding the mechanism underlying collective cell migration enabled by these methods. Together, the paper enables a broad overview on the methods and tools currently available to unravel the biophysical mechanisms pertinent to cell collective migration, as well as providing perspectives on future development towards eventually deciphering the key mechanisms behind the most lethal feature of cancer.
Moritz Hoffmann, Andrea Lattuada, Frank McSherry
et al.
We design and implement Megaphone, a data migration mechanism for stateful distributed dataflow engines with latency objectives. When compared to existing migration mechanisms, Megaphone has the following differentiating characteristics: (i) migrations can be subdivided to a configurable granularity to avoid latency spikes, and (ii) migrations can be prepared ahead of time to avoid runtime coordination. Megaphone is implemented as a library on an unmodified timely dataflow implementation, and provides an operator interface compatible with its existing APIs. We evaluate Megaphone on established benchmarks with varying amounts of state and observe that compared to naïve approaches Megaphone reduces service latencies during reconfiguration by orders of magnitude without significantly increasing steady-state overhead.
Mohd Anuar Mat Isa, Ramlan Mahmod, Nur Izura Udzir
et al.
This paper presents a trust computation for international relations and its calculus, which related to Bayesian inference, Dempster Shafer theory and subjective logic. We proposed a method that allows a trust computation which is previously subjective and incomputable. An example of case study for the trust computation is the United States of America Great Britain relations. The method supports decision makers in a government such as foreign ministry, defense ministry, presidential or prime minister office. The Department of Defense (DoD) may use our method to determine a nation that can be known as a friendly, neutral or hostile nation.
A system of partial differential equations is derived as a model for the dynamics of a honey bee colony with a continuous age distribution, and the system is then extended to include the effects of a simplified infectious disease. In the disease-free case we analytically derive the equilibrium age distribution within the colony and propose a novel approach for determining the global asymptotic stability of a reduced model. Furthermore, we present a method for determining the basic reproduction number $R_0$ of the infection; the method can be applied to other age-structured disease models with interacting susceptible classes. The results of asymptotic stability indicate that a honey bee colony suffering losses will recover naturally so long as the cause of the losses is removed before the colony collapses. Our expression for $R_0$ has potential uses in the tracking and control of an infectious disease within a bee colony.
AbstractWe propose a theory of free movement of goods and labor between two economies in the presence of moral hazard. Each country produces two final goods where the productive efforts of workers cannot be perfectly observed, or verified only in the complex industry. We show that national institutional quality and the system of the early childhood care and education determine the pattern of international trade. However, individuals’ decisions to emigrate depend only on the national institutional quality, where the country with more developed institutions serves as the host country of immigrants. We conclude that international labor movement promotes international trade.JEL classification: B52, I21, F10, F16, F22, J24.
AbstractTemporary migration programmes have re‐emerged as a preferred mechanism for regulating labour migration in many migrant‐receiving countries in the past decade. In this paper, I consider the role of shifting Canadian immigration policies, notably the expanded streams for temporary workers, in the changing flow of migrants from Trinidad to Canada. Temporary programmes can bring workers to Canada relatively quickly, but they limit access to permanent residency and citizenship, in sharp contrast to most of Canada's earlier immigration policies. Ethnographic fieldwork reveals that Trinidadians actively seeking to make the move to Canada have little interest in new temporary work programmes. Rather, they continue to plan futures in Canada that they expect to be years in the making. I consider some reasons for this apparent refusal to submit to the new migration realities. I show that present‐day Trinidadian emigrant desires and practices are deeply connected to individual, familial and national emigration and immigration histories. Trinidadians are declining to participate in new immigration regimes and are restricting their migration practices to those forms that are historically familiar and have been proven successful. I attempt to show how ethnographic approaches that take seriously migrants' agency can assist in developing a fuller understanding of the ways in which migration flows are changing. These approaches reveal what are otherwise the silences and invisibility surrounding those whose previous access to permanent migration streams has been diminished through neoliberal restructuring of migration policy. I argue that temporary worker policies disregard long‐standing histories of migration and engagement with capitalist processes for people in particular regions of the world, rendering them, for policy purposes, effectively “people without history” (Wolf, 1982).
AbstractImmigration policy is a very unlikely case for EU integration. EU policy‐making is constrained by member states' sovereignty claims and interest heterogeneity. Still, tentative integration towards EU conditions of entry and residence for some immigrant categories can be observed. By using the example of the skilled labour migration directive, the article explains how deadlock in policy‐making was overcome. It explores the factors that led to agreement in the EU immigration policy area, from the Commission's first proposal on labour migration in 2001 to its adoption in 2009. Explanations for integration in the policy area are member states' venue shopping the EU level for changing domestic legislation, their interest in locking‐in national standards in EU law, and the EU Commission's agenda‐framing. Strategic partitioning of policy was also used by actors to overcome deadlock in policy‐making. The reframing of policies, by reducing their scope to a few narrowly defined immigrant categories, influenced their adoption. This mechanism was observed in studying the eight years of policy‐making leading to the labour migration directive. The longitudinal analysis helps to identify the key dynamics that define this nascent EU policy area.
This article aims to contribute to an understanding of contemporary American attitudes toward immigration. It extends work by Espenshade and Calhoun (1993) who analyzed data from a southern California survey in June 1983 about the impacts of undocumented migrants and illegal immigration. There has not been a follow-up study that evaluates more recent evidence to see how residents throughout the United States feel about overall levels of immigration (legal and undocumented). The paper uses data from a CBS News/New York Times poll conducted in June 1993. Respondents were asked whether they would like to see the level of immigration to the United States increased, decreased or kept the same. We test several hypotheses about factors influencing respondents’ attitudes, including the importance of previously unexamined predictors. These new hypotheses relate to views about the health of the U.S. economy, feelings of social and political alienation, and isolationist sentiments concerning international economic issues and foreign relations. One important discovery is the close connection between possessing restrictionist immigration attitudes and having an isolationist perspective along a broader array of international issues.
Michael Khasin, Baruch Meerson, Evgeniy Khain
et al.
Many populations in nature are fragmented: they consist of local populations occupying separate patches. A local population is prone to extinction due to the shot noise of birth and death processes. A migrating population from another patch can dramatically delay the extinction. What is the optimal migration rate that minimizes the extinction risk of the whole population? Here we answer this question for a connected network of model habitat patches with different carrying capacities.
In this study, data from the U.S. State Department on visas issued abroad and information from other sources are used to examine trends in African emigration to the U.S. The results suggest that, on average, moderate increases in African Gross Domestic Product between 1992 and 2007 had a buffering effect on emigration trends. Yet, emigration to the U.S. increased much faster from the poorest than wealthiest countries in Africa. Contrary to expectations, larger emigration increases were found in Africa's non-English than English-speaking countries. Despite the increasing overall trend, however, critical differences were observed in the impacts of specific types of flows. For example, overall trends were driven by increases in Diversity Visa migration, refugee movements, and the migration of immediate relatives. However, significant declines were observed in employment-related emigration from Africa to the U.S. The results further suggest that impact of trends in African fertility, urbanization, and phone use are circumscribed to specific contexts and types of migration flows. The findings, therefore, provide an empirical basis for concluding that the dynamics of African migration to the U.S. are becoming increasingly more complex.