Branches Merge Research Articles

On the selection of Saffman–Taylor viscous fingers for divergent flow in a wedge

We study self-similar viscous fingering for the case of divergent flow within a wedge-shaped Hele-Shaw cell. Previous authors have conjectured the existence of a countably infinite number of selected solutions, each distinguished by a different value of the relative finger angle. Interestingly, the associated solution branches have been posited to merge and disappear in pairs as the surface tension decreases. For the first time, we demonstrate how the selection mechanism can be derived based on exponential asymptotics. Asymptotic predictions of the finger-to-wedge angle are additionally given for different sized wedges and surface-tension values. The merging of solution branches is explained; this feature is qualitatively different to the case of classic Saffman–Taylor viscous fingering in a parallel channel configuration. Moreover, because the asymptotic framework does not highly depend on specifics of the wedge geometry, the proposed theory for branch merging in our self-similar problem likely relates much more widely to tip-splitting instabilities in time-dependent flows in circular and other geometries, where the viscous fingers destabilise and divide in two.

A*–Ant Colony Optimization Algorithm for Multi-Branch Wire Harness Layout Planning

The planning of multi-branch cable harness layouts holds significant practical importance in aircraft industrial contexts, yet it has received limited attention in prior research. This study aims to address the matter concerning the significance of managing multiple constraints and preventing loops. It formulates the problem as an optimization problem in 3D free-form space and resolves it using an extended A* path planning approach in combination with the ant colony optimization algorithm. Initially, a feasible search space for wiring is established through the repair and simplification of the input CAD model. Subsequently, the topology of a multi-branched wiring harness is identified, taking into account industrial requirements related to cable physics, turning, support, bundling, and electromagnetic compatibility constraints. Specifically, the disassembly or merging of branches and loops is employed to avoid wire loops. Ultimately, we propose an A*–ant colony optimization algorithm (A*-ACO) with an enhanced heuristic function for neighboring points, incorporating a concentration increment model. Experimental tests illustrate the effectiveness of this approach in minimizing wire loops and reducing the total cable layout cost, considering factors such as length, bundling, and turning costs. It results in a reduction of 67.0%, 68.5%, and 51.1% compared to A*, ACO, and manual wiring methods, respectively.

Conditional temporal GAN for intent-aware vessel trajectory prediction in the precautionary area

Accurate vessel trajectory prediction is crucial for ensuring maritime traffic safety and efficiency, particularly in precaution areas characterized by multi-waterway branch merging and frequent traffic conflicts. However, predicting trajectories in these areas poses significant challenges due to the uncertain future intents of different directional branches resulting in diverse motion patterns and multiple possible paths. To address this issue and minimize the prediction error, we propose a conditional temporal generative adversarial network (CTGAN). Specifically, in this method, the trajectory generator is developed to capture the inherently dynamic of ship motions and outputs the future trajectory proposals, while the intent classifier is designed to evaluate whether the trajectory proposals are consistent with the hidden intention. With the adversarial training strategy, the trajectory generator and intent classifier form a closed loop, feedback informative signals to each other that enables generating the intent-constrained trajectory. In addition, a mixed adversarial loss function was designed to capture the spatial–temporal dependencies among the vessel motions for producing consistent trajectories that complied with plausible ship dynamics. Experiments on extensive naturalistic vessel trajectory data demonstrate that compared with the baseline methods, the proposed model achieves comparable or better prediction performance.

The role of exponential asymptotics and complex singularities in self-similarity, transitions, and branch merging of nonlinear dynamics

We study a prototypical example in nonlinear dynamics where transition to self-similarity in a singular limit is fundamentally changed as a parameter is varied. Here, we focus on the complicated dynamics that occur in a generalised unstable thin-film equation that yields finite-time rupture. A parameter, n, is introduced to model more general disjoining pressures. For the standard case of van der Waals intermolecular forces, n=3, it was previously established that a countably infinite number of self-similar solutions exist leading to rupture. Each solution can be indexed by a parameter, ϵ=ϵ1>ϵ2>⋯>0, and the prediction of the discrete set of solutions requires examination of terms beyond-all-orders in ϵ. However, recent numerical results have demonstrated the surprising complexity that exists for general values of n. In particular, the bifurcation structure of self-similar solutions now exhibits branch merging as n is varied. In this work, we shall present key ideas of how branch merging can be interpreted via exponential asymptotics.

Convergence of the Malvinas Current branches near 44°S

Field measurements of the Malvinas Current (MC) velocity distribution were performed at the western slope of the Argentine Basin in the South Atlantic Ocean between 47° and 43°S including several sections across the current. The data were collected in January and March 2020 using a Shipborne Acoustic Current Doppler Profiler (SADCP) and allowed us to study circulation patterns in the upper 700 m of the ocean. The observations reveal substantial differences in the current structures at each location; the SADCP data suggest that two distinct current branches at 46°S converge downstream near 44°S making it difficult to distinguish the high-velocity cores farther north. A detailed comparison between the velocity structures indicates that the branches converge due to the change in the orientation and width of the continental slope, and is consistent with potential vorticity conservation. At the same time, satellite altimetry shows that the branches merge to a single high-velocity jet, suggesting that satellite altimetry does not reproduce all features of the MC internal structure and indicates the importance of further direct velocity observations in this region. Despite the above-mentioned limitations of altimetry, the satellite-derived geostrophic velocities suggest that the pathways of the MC high-velocity jets are quite stable. In addition, both satellite altimetry and direct measurements indicate that the branches tend to converge downstream near 44°S.

EFFECTS OF THE CONCEPTS OF KHALWA DAR-ANJUMAN AND MALĀMA ON THE ECONOMIC MENTALITY AND PRACTICES IN FUTUWWA AND AKHISM ORGANISATIONS

In this study, the effects of the concepts of khalwa dar-anjuman and malāma in the ṣūfī literature on the economic mentality and practices in futuwwa and akhism organizations are discussed. Khalwa dar-anjuman is a ṣūfī term that expresses the spiritual development of a person by existing in society. According to this principle, which is one of the basic principles of the Naqshbandiyya order, a person should not turn away from work and turn to seclusion, but should be at work with the love of Allah in his heart. This understanding can also be expressed with the phrase “hands to work, hearth to God”. When the concept of malāma, which is observed to be mentioned and discussed together with Bektashism, is also considered in terms of economic mentality, it is seen that it requires similar attitudes with the principle of khalwa daranjuman and its implementation is realized in futuwwa and akhism organisations. Malāma morality is based on concealing its spiritual aspect under professional and social identity with the aim of protecting sincerity. In connection with this, futuwwa means serving all existence with generosity and akhism can be considered as an organized view of economic morality and solidarity. In the study, the unity of these concepts on the economic and social ground, which causes separation by being associated with the principles and methods of different sects today, is revealed and the unity in the essence of ṣūfī orders is emphasized. The fact that all ṣūfī ways meet in the Prophet Muhammed (pbuh) and in common values is like the merging of different branches under the same root. Differences in ṣūfī ways are not essential but incidental. For the peace of humanity, there is a need to realize the diversity that brings mercy, not division. Keywords: Khalwa Dar-Anjuman, Malāma, Futuwwa, Akhism, Economic Mentality.

Structure and Circulation of Atlantic Water Masses in the St. Anna Trough in the Kara Sea

The inflow of warm and saline Atlantic water from the North Atlantic to the Western Arctic is provided by two branches, namely, the Fram Strait branch water and the Barents Sea branch water. The pathways of these branches merge at the St. Anna Trough, and then both branches propagate eastward along the continental slope, albeit at different depths. As a result, the local interaction between these branches in the trough affects the properties of the large-scale Atlantic water flow to the Eastern Arctic and the deep Arctic basins. In this study, we report extensively in situ measurements with high spatial coverage (56 hydrological stations organized into 7 transects) in the St. Anna Trough, obtained in August and October 2021. Based on these data, we reconstructed the thermohaline structure and circulation in this area and obtained new insights, which are crucial for the assessment of the interaction and heat balance of water masses in the trough. First, we state that the majority of the Fram Strait branch water is recirculated in the trough within the stable cyclonic gyre, while a smaller fraction returns to the continental slope. The formation of this gyre increases the residence time of the Fram Strait branch water in the trough and decreases the intensity of water and heat exchange between the trough and the continental slope. Second, we describe the dynamic interaction between the northward flow of the Barents Sea branch water and the surface layer. It causes intense transport of warm surface water from the Kara and Barents seas adjacent to the Novaya Zemlya toward the continental slope and its mixing with the Barents Sea branch water along the eastern part of the trough. These processes result in increased surface temperature at the eastern part of the trough, which enhances ice melting at the study area and increases the duration of the ice-free period.

Composition of construction services with hierarchical planning on digital platform

The digital platform business model offers opportunities for the construction industry to address the problem of extensive development by elaborately orchestrating a range of construction services to meet complex construction requirements. The presence of isomeric and coupling relationships between two construction services leads to alternative execution paths in the service network. However, the problem of generating a service network with alternative branches has been scarcely investigated. This study proposes a hierarchical task network (HTN) approach to address the service composition problem. Specifically, the approach performs a depth-first traversal search to address the isomeric and coupling relationships. A branch merging mechanism is integrated to eliminate repeated planning caused by equivalent planning nodes. The experimental studies demonstrate that the approach can generate valid and correct branches in the construction service network and that the devised branch merging mechanism can significantly improve the efficiency of the approach.

Structure and scalar correlation of ammonia/air turbulent premixed flames in the distributed reaction zone regime

Instantaneous structures of turbulent premixed ammonia/air flames on a piloted jet burner were investigated using simultaneous planar laser-induced fluorescence (PLIF) and Rayleigh thermometry measurements. Two-dimensional spatial distributions of temperature were simultaneously measured with those of the NH radical and the NO pollutant, respectively. Experiments were conducted for stoichiometric flames under five jet velocities. All flames are located in the distributed reaction zone regime of the Borghi-Peters diagram with the Karlovitz (Ka) number ranging from 274 to 4720. The NH PLIF images are used to characterize the fuel consumption layer of the reaction zones since the formation of NH is associated with the consumption of ammonia. The NH PLIF results show that under all flame conditions investigated, the NH layer remains thin in the proximity of the burner while it becomes progressively thickened and distorted by turbulence with increasing turbulent intensity and axial distance. For flames with Ka of 274, the NH layer essentially remains thin, while at Ka of 590 or higher, significant broadening of the NH layer is observed. Probability density functions (PDFs) of the NH layer thickness show that the NH layer can be broadened by 3 – 4 times as the flames are developed downstream. The broadening of the NH layer is considered to indicate that the flames are in the distributed reaction zone regime. The boundary between the thin-reaction zone regime and the distributed reaction zone regime occurs at a much larger Ka than that in methane/air flames. The broadening of the NH layer is due to the penetration of the turbulent eddies and the merging of flame branches. The latter occurs mainly near the flame tips. NO is shown to exist in a wide region in space, across the preheat zone, reaction zone, and postflame zone. NO formation occurs mainly in the reaction zone, however, it is transported by turbulence eddies to the preheat zone and by convection to the postflame zone. The temperature measurements indicate that the preheat zone is broadened in all flames investigated. The broadening of the preheat zone is moderately sensitive to the Ka number while it is more sensitive to the integral length scale of the flames.

On factorizable S-matrices, generalized TTbar, and the Hagedorn transition

We study solutions of the Thermodynamic Bethe Ansatz equations for relativistic theories defined by the factorizable S-matrix of an integrable QFT deformed by CDD factors. Such S-matrices appear under generalized TTbar deformations of integrable QFT by special irrelevant operators. The TBA equations, of course, determine the ground state energy E(R) of the finite-size system, with the spatial coordinate compactified on a circle of circumference R. We limit attention to theories involving just one kind of stable particles, and consider deformations of the trivial (free fermion or boson) S-matrix by CDD factors with two elementary poles and regular high energy asymptotics — the “2CDD model”. We find that for all values of the parameters (positions of the CDD poles) the TBA equations exhibit two real solutions at R greater than a certain parameter-dependent value R*, which we refer to as the primary and secondary branches. The primary branch is identified with the standard iterative solution, while the secondary one is unstable against iterations and needs to be accessed through an alternative numerical method known as pseudo-arc-length continuation. The two branches merge at the “turning point” R* (a square-root branching point). The singularity signals a Hagedorn behavior of the density of high energy states of the deformed theories, a feature incompatible with the Wilsonian notion of a local QFT originating from a UV fixed point, but typical for string theories. This behavior of E(R) is qualitatively the same as the one for standard TTbar deformations of local QFT.

How the adoption of feature toggles correlates with branch merges and defects in open‐source projects?

AbstractContextBranching has been widely adopted in version control to enable collaborative software development. However, the isolation caused by branches may impose challenges on the upcoming merging process. Recently, companies like Google, Microsoft, Facebook, and Spotify, among others, have adopted trunk‐based development together with feature toggles. This strategy enables collaboration without the need for isolation through branches, potentially reducing the merging challenges. However, the literature lacks evidence about the benefits and limitations of feature toggles to collaborative software development.Objective/methodIn this article, we study the effects of applying feature toggles on 949 open‐source projects written in six different programming languages. We first identified the moment in which each project adopted a feature toggles framework. Then, we observed whether the adoption implied significant changes in the frequency or complexity of branch merges and the number of defects, and the average time to fix them. Finally, we compared the obtained results with results obtained from a set of control projects that do not use feature toggles frameworks.Results/conclusionWe could observe a reduction in the average merge effort and an increase in the average total time needed to fix defects after adopting feature toggles frameworks. However, we could not confirm that this increase was influenced by the use of feature toggles.

Integrasi Sistem Pengawasan Dps Terhadap Lks Bmt Ugt Nusantara Kabupaten Situbondo

The integration of the supervisory system at BMT UGT Nusantara (originally named BMT Sidogiri) by DPS has three supervisors, namely management supervisors, sharia supervisors, and financial supervisors. The three supervisors are both walking or supervising according to their respective positions. The supervision carried out by DPS on BMT Nusantara in Situbondo is integrated in one branch, so that the effectiveness of the supervision performance is one-stop integrated. The supervision of the work system of sharia financial institutions is usually carried out for six months once to the existing branches of BMT UGT Nusantara, but in this supervision the Sharia Supervisory Board (DPS) does not always go directly to conduct supervision, either in terms of products, contracts and so on, but the Sharia Supervisory Board (DPS) formed a sharia team devoted to controlling the existing branches of BMT UGT Nusantara. The supervision of the Sharia Supervisory Board (DPS) is unified in several branches due to the decision of the central management, in which the merging of several branches into one Sharia Supervisory Board (DPS) is not an obstacle in its supervision.

Optimizing demand‐driven null dereference verification via merging branches

AbstractNull dereference is a common type of runtime failure in Java programs, and it is necessary to verify whether a dereference in the program is safe. However, previous works often have redundant path exploration and high false positive rate. In this paper, we propose a merged null dereference verification (MNDV) approach. MNDV employs a backward, path‐sensitive inter‐procedural analysis technique to verify a given dereference as safe or potentially unsafe. It uses a branch merging strategy to remove redundant paths, and a method call's relevance to the null references is checked to determine whether it is necessary to explore the internal codes of the method. We have evaluated the approach in some standard benchmark programs. Compared with some existing approaches, our approach reduces false alarm rate and effectively reduce time and memory consumption.

Correction of topological errors in automated traces of neurites.

Our understanding of synaptic connectivity in the brain relies on the ability to accurately trace sparsely labeled neurons from 3D optical microscopy stacks of images. A variety of automated algorithms and software tools have been developed for this task. These algorithms can capture the general layout of neurites with high fidelity, but the resulting traces often contain topological errors such as broken and incorrectly merged branches. Even a small number of isolated topological errors can drastically alter the connectivity, and therefore, their detection and correction are paramount for connectomics studies. Here, we describe an automated trace proofreading approach that utilizes machine learning to correct trace topology. Multiple stacks of neuron images were traced by two users to create a labeled dataset and assess the baseline of inter-user variability. All traces were then disconnected at branch points and a deep neural network was trained to detect the correct way of reconnecting the branches. Custom morphological features were generated for each cluster of branch points, in a way that is dependent on a merging scenario but invariant to translations, rotations, and reflections of the cluster in the imaging plane. The features and image volume centered at the branch point were used for training a neural network that concatenates these input streams and outputs the confidence measure for different branch merging scenarios. The designed method significantly reduces the number of topological errors in automated traces and comes close to the accuracy achieved by expert users which is the gold standard in the field.

Large eddy simulation of an inclined jet in crossflow with vortex generators

ABSTRACT Film cooling is one of the essential approaches to cool high-performance turbine blades. Film cooling with delta winglet vortex generator pair (DWVGP) placed upstream of the cooling hole is investigated by large eddy simulation (LES) at the blowing ratio of M=1.0. Film cooling effectiveness and vortical structures are evaluated in the flow field of a jet in crossflow (JICF). Results indicate that film cooling effectiveness increases significantly for the DWVGP case. As a dominant vortex structure, the ubiquitous counter-rotating vortex pair (CRVP) is recognized in the flow field. It has a detrimental effect that lifts the coolant off the cooling surface. The DWVGP evolved anticounter-rotating vortex pair (anti-CRVP) has the opposite sense of rotation to the jet introduced CRVP, which undertakes vorticity decay when developing downstream of the cooling hole. With the downwash effect of anti-CRVP, the reattachment of coolant is earlier, and a wide region of enhanced film cooling effectiveness in the spanwise direction is achieved. The coherent vortex structures including the classical vortices in the flow field and the vortex generator pair introduced vortices are analyzed. The genesis and evolution mechanism of CRVP with and without the vortex generators are discussed. It indicates that three branches of upstream spiral structures from the nozzle tube contribute to the CRVP. The merging of CRVP upstream branches is delayed by the vortex generators evolved anti-CRVP, which postpones the formation of downstream CRVP.

Prostranstvennaya struktura i vnutrigodovaya izmenchivost' fronta morya Ueddella po dannym reanaliza NOAA OISST

Based on the NOAA OISST reanalysis data, the spatial structure of the Weddell Sea Front in the climatic field of the sea surface temperature was analyzed and the seasonal variability of front’s characteristics was estimated. The spatial position of the frontal zone in the Weddell Sea was analyzed using distributions of the total horizontal temperature gradient. The characteristics of the front (the position of the gradients' extrema corresponding to the front, their magnitude and temperature on the front axis) were determined for each month on the profiles of meridional and zonal temperature gradients along meridians and parallels with a discreteness of 2.5° of longitude and 0.25° of latitude. It is shown that the interaction of Weddell Sea cold waters, which are transported by currents northward along the Antarctic Peninsula coasts, with the warmer waters of the eastern shelf of the Antarctic Peninsula and the Bransfield Strait surface water causes formation of two branches of the Weddell Sea Front. These branches round from a vast shelf at the Antarctic Peninsula tip and the Joinville archipelago the south and north and are traced further east along the boundaries of the bottom rise located approximately between 62.5S and 64.5S. To the south of the South Orkney Islands shelf, the two branches merge into one front, which follows to the east along the depth dump of the relative shallow between the South Orkney and South Sandwich Islands. In the seasonal cycle of the Weddell Sea Front intensity, a time lag was revealed of the front intensification period in the direction from west to east. In Bransfield Strait the front is most intense in February, between the Antarctic Peninsula tip and the South Orkney Islands – in March, east of the South Orkney Islands – in April. The branch of the Weddell Sea Front off the northeastern of the Antarctic Peninsula coasts intensifies in November – January, in the western part of the water area east of the James Ross and Snow Hill Islands – in January – February.

Plasmons and screening in finite-bandwidth two-dimensional electron gas

The dynamical and nonlocal dielectric function of a two-dimensional electron gas (2DEG) with finite energy bandwidth is computed within random-phase approximation. For large bandwidth, the plasmon dispersion has two separate branches at small and large momenta. The large momenta branch exhibits negative quasi-flat dispersion. The two branches merge with decreasing bandwidth. We discuss how the maximum energy plasmon mode which resides at energies larger than all particle-hole continuum can potentially open a route to low-loss plasmons. Moreover, we discuss the bandwidth effects on the static screening of the charged and magnetic impurities.

Understanding plasmon dispersion in nearly free electron metals: Relevance of exact constraints for exchange-correlation kernels within time-dependent density functional theory

Small-wavevector excitations in Coulomb-interacting systems can be decomposed into the high-energy collective longitudinal plasmon and the low-energy single-electron excitations. At the critical wavevector and corresponding frequency where the plasmon branch merges with the single-electron excitation region, the collective energy of the plasmon dissipates into single electron-hole excitations. The jellium model provides a reasonable description of the electron-energy-loss spectrum (EELS) of metals close to the free-electron limit. The random phase approximation (RPA) is exact in the high-density limit but can capture the plasmonic dispersion reasonably even for densities with rs > 1. RPA and all beyond-RPA methods investigated here, result in a wrong infinite plasmon lifetime for a wavevector smaller than the critical one where the plasmon dispersion curve runs into particle-hole excitations. Exchange-correlation kernel corrections to RPA modify the plasmon dispersion curve. There is however a large difference in the construction and form of the kernels investigated earlier. Our current work introduces recent model exchange-only and exchange-correlation kernels and discusses the relevance of some exact constraints in the construction of the kernel. We show that, because the plasmon dispersion samples a range of wavevectors smaller than the range sampled by the correlation energy, different kernels can make a strong difference for the correlation energy and a weak difference for the plasmon dispersion. This work completes our understanding about the plasmon dispersion in realistic metals, such as Cs, where a negative plasmon dispersion has been observed. We find only positive plasmon dispersion in jellium at the density for Cs.

Priority Branches for Ship Detection in Optical Remote Sensing Images

Much attention is being paid to using high-performance convolutional neural networks (CNNs) in the area of ship detection in optical remoting sensing (ORS) images. However, the problem of false negatives (FNs) caused by side-by-side ships cannot be solved, and the number of false positives (FPs) remains high. This paper uses a DLA-34 network with deformable convolution layers as the backbone. The network has two priority branches: a recall-priority branch for reducing the number of FNs, and a precision-priority branch for reducing the number of FPs. In our single-shot detection method, the recall-priority branch is based on an anchor-free module without non-maximum suppression (NMS), while the precision-priority branch utilizes an anchor-based module with NMS. We perform recall-priority branch functions based on the output part of the CenterNet object detector to precisely predict center points of bounding boxes. The Bidirectional Feature Pyramid Network (BiFPN), combined with the inference part of YOLOv3, is used to improve the precision of precision-priority branch. Finally, the boxes from two branches merge, and we propose priority-based selection (PBS) for choosing the accurate ones. Results show that our proposed method sharply improves the recall rate of side-by-side ships and significantly reduces the number of false alarms. Our method also achieves the best trade-off on our improved version of HRSC2016 dataset, with 95.57% AP at 56 frames per second on an Nvidia RTX-2080 Ti GPU. Compared with the HRSC2016 dataset, not only are our annotations more accurate, but our dataset also contains more images and samples. Our evaluation metrics also included tests on small ships and incomplete forms of ships.

Spectral function of Mott-insulating Hubbard ladders: From fractionalized excitations to coherent quasiparticles

We study the spectral function of two-leg Hubbard ladders with the time-dependent density matrix renormalization group method (tDMRG). The high-resolution spectrum displays features of spin-charge separation and a scattering continuum of excitations with coherent bands of bound states `leaking' from it. As the inter-leg hopping is increased, the continuum in the bonding channel moves to higher energies and spinon and holon branches merge into a single coherent quasi-particle band. Simultaneously, the spectrum undergoes a crossover from a regime with two minima at incommensurate values of $k_x$ (a Mott insulator), to one with a single minimum at $k_x=\pi$ (a band insulator). We identify the presence of a continuum of scattering states consisting of a triplon and a polaron. We analyze the processes leading to quasiparticle formation by studying the time evolution of charge and spin degrees of freedom in real space after the hole is created. At short times, incoherent holons and spinons are emitted but after a characteristic time $\tau$ charge and spin form polarons that propagate coherently.