Stream Structure Research Articles

Analysis of E-commerce Live Streaming and Traffic Generation

The Internet has become an integral part of our society. This paper focuses on TikTok, one of today's most popular Internet platforms, and analyzes its e-commerce live streaming structure and traffic generation methods. Through a comprehensive examination of TikTok's current status and prospects, this study aims to deepen our understanding of the current Internet model and identify emerging trends. TikTok's commercial liquidity is essential to its success as a commercial platform. However, balancing commercial interests with user experience has challenged the platform's development. The key to TikTok's growth is creating a sticky user base and fostering a unique platform culture. Rather than prioritizing commercial gain over user experience, TikTok aims to engage users in the commercial process, which is critical for sustainable development. Overall, this paper sheds light on the complexities of e-commerce live streaming and traffic generation on TikTok and highlights the platform's unique approach to balancing commercial interests with user experience.

Numerical simulation of acoustic streaming in standing waves

This study presents a numerical investigation of acoustic streaming motion (of the Rayleigh type) in a compressible gas inside two-dimensional rectangular enclosures. To numerically study the effects of the sound field intensity on the formation process of streaming structures, we propose to discretize the fully compressible form of the two-dimensional Navier-Stokes equations using a high-order (formally greater or equal to fourth-order) accurate numerical scheme in both space and time. The proposed numerical solver utilizes high-order compact schemes along each spatial dimension combined with a filtering procedure when it is necessary. Acoustic standing waves are excited inside the enclosures and the resulting acoustic streaming patterns are investigated for low and high-intensity waves, in both linear and nonlinear regimes following closely the work of Daru et al. (2013). An extended investigation indicates that without the incorporation of an appropriate filter, the application of the high-order compact schemes in case of fast streaming results in spurious oscillations which inhibit their applicability. Following the recent relevant literature, the numerical simulations performed demonstrate the ability of the proposed numerical approach to reproduce efficiently and robustly the transitions from regular acoustic streaming to irregular streaming and the relevant phenomena confirming results that have been previously presented.

A giant thin stellar stream in the Coma Galaxy Cluster

The study of dynamically cold stellar streams reveals information about the gravitational potential where they reside and provides important constraints on the properties of dark matter. However, the intrinsic faintness of these streams makes their detection beyond Local environments highly challenging. Here, we report the detection of an extremely faint stellar stream (μg, max = 29.5 mag arcsec−2) with an extraordinarily coherent and thin morphology in the Coma Galaxy Cluster. This Giant Coma Stream spans ∼510 kpc in length and appears as a free-floating structure located at a projected distance of 0.8 Mpc from the center of Coma. We do not identify any potential galaxy remnant or core, and the stream structure appears featureless in our data. We interpret the Giant Coma Stream as being a recently accreted, tidally disrupting passive dwarf. Using the Illustris-TNG50 simulation, we identify a case with similar characteristics, showing that, although rare, these types of streams are predicted to exist in Λ-CDM. Our work unveils the presence of free-floating, extremely faint and thin stellar streams in galaxy clusters, widening the environmental context in which these objects are found ahead of their promising future application in the study of the properties of dark matter.

Static and Streaming Data Structures for Fréchet Distance Queries

Given a curve P with points in ℝ d in a streaming fashion, and parameters ɛ > 0 and k , we construct a distance oracle that uses \(O(\frac{1}{\varepsilon })^{kd}\log \varepsilon ^{-1}\) space, and given a query curve Q with k points in ℝ d returns in \(\tilde{O}(kd)\) time a 1+ɛ approximation of the discrete Fréchet distance between Q and P . In addition, we construct simplifications in the streaming model, oracle for distance queries to a sub-curve (in the static setting), and introduce the zoom-in problem. Our algorithms work in any dimension d , and therefore we generalize some useful tools and algorithms for curves under the discrete Fréchet distance to work efficiently in high dimensions.

OSNN: An Online Semisupervised Neural Network for Nonstationary Data Streams.

Learning from data streams that emerge from nonstationary environments has many real-world applications and poses various challenges. A key characteristic of such a task is the varying nature of target functions and data distributions over time (concept drifts). Most existing work relies solely on labeled data to adapt to concept drifts in classification problems. However, labeling all instances in a potentially life-long data stream is frequently prohibitively expensive, hindering such approaches. Therefore, we propose a novel algorithm to exploit unlabeled instances, which are typically plentiful and easily obtained. The algorithm is an online semisupervised radial basis function neural network (OSNN) with manifold-based training to exploit unlabeled data while tackling concept drifts in classification problems. OSNN employs a novel semisupervised learning vector quantization (SLVQ) to train network centers and learn meaningful data representations that change over time. It uses manifold learning on dynamic graphs to adjust the network weights. Our experiments confirm that OSNN can effectively use unlabeled data to elucidate underlying structures of data streams while its dynamic topology learning provides robustness to concept drifts.

Dorsal visual stream and LIMK1: hemideletion, haplotype, and enduring effects in children with Williams syndrome

BackgroundWilliams syndrome (WS), a rare neurodevelopmental disorder caused by hemizygous deletion of ~ 25 genes from chromosomal band 7q11.23, affords an exceptional opportunity to study associations between a well-delineated genetic abnormality and a well-characterized neurobehavioral profile. Clinically, WS is typified by increased social drive (often termed “hypersociability”) and severe visuospatial construction deficits. Previous studies have linked visuospatial problems in WS with alterations in the dorsal visual processing stream. We investigated the impacts of hemideletion and haplotype variation of LIMK1, a gene hemideleted in WS and linked to neuronal maturation and migration, on the structure and function of the dorsal stream, specifically the intraparietal sulcus (IPS), a region known to be altered in adults with WS.MethodsWe tested for IPS structural and functional changes using longitudinal MRI in a developing cohort of children with WS (76 visits from 33 participants, compared to 280 visits from 94 typically developing age- and sex-matched participants) over the age range of 5–22. We also performed MRI studies of 12 individuals with rare, shorter hemideletions at 7q11.23, all of which included LIMK1. Finally, we tested for effects of LIMK1 variation on IPS structure and imputed LIMK1 expression in two independent cohorts of healthy individuals from the general population.ResultsIPS structural (p < 10−4 FDR corrected) and functional (p < .05 FDR corrected) anomalies previously reported in adults were confirmed in children with WS, and, consistent with an enduring genetic mechanism, were stable from early childhood into adulthood. In the short hemideletion cohort, IPS deficits similar to those in WS were found, although effect sizes were smaller than those found in WS for both structural and functional findings. Finally, in each of the two general population cohorts stratified by LIMK1 haplotype, IPS gray matter volume (pdiscovery < 0.05 SVC, preplication = 0.0015) and imputed LIMK1 expression (pdiscovery = 10−15, preplication = 10−23) varied according to LIMK1 haplotype.ConclusionsThis work offers insight into neurobiological and genetic mechanisms responsible for the WS phenotype and also more generally provides a striking example of the mechanisms by which genetic variation, acting by means of molecular effects on a neural intermediary, can influence human cognition and, in some cases, lead to neurocognitive disorders.

Forecast evaluation of the North Pacific jet stream using AR Recon dropwindsondes

AbstractThe term jet stream generally refers to a narrow region of intense winds near the top of the midlatitude or subtropical troposphere. It is in the midlatitude jet stream where instabilities and waves may develop into synoptic‐scale systems, which in turn makes accurately resolving the structure of the jet stream and associated features critical for atmospheric development, predictability, and impacts, such as extreme precipitation and winds. Using dropwindsonde observations collected during the Atmospheric River Reconnaissance (AR Recon) campaign from 2020 to 2022, this study assesses the North Pacific jet stream structure in the European Centre for Medium‐Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). Results show that the IFS has a slow‐wind bias on the lead times assessed, with the strongest winds (≥50 m·s−1) having a bias of up to −1.88 m·s−1 on forecast day 4. Also, the IFS cannot resolve the sharp potential vorticity (PV) gradient across the jet stream and tropopause, and this PV gradient weakens with forecast lead time. Cases with larger wind biases are characterized by higher PV biases and PV biases tend to be larger for cases with a higher horizontal PV gradient. These results suggest that further model‐based experiments are needed to identify and address these biases, which could ultimately yield increased forecast accuracy.

False discovery rate approach to dynamic change detection

In multiple data stream surveillance, the rapid and sequential identification of individuals whose behavior deviates from the norm has become particularly important. In such applications, the state of a stream can alternate, possibly multiple times, between a null state and an alternative state. To balance the ability to detect two types of changes, that is, a change from the null to the alternative and back to the null, we propose a new multiple testing procedure based on a penalized version of the generalized likelihood ratio test statistics for change detection. The false discovery rate (FDR) at each time point is shown to be controlled under some mild conditions on the dependence structure of data streams. A data-driven approach is developed for selection of the penalization parameter. Its advantage is demonstrated via simulation and a data example.

Numerical investigation of non-planarity and relative motion for bionic slotted wings

Bird wings have split primary feathers that extend out from the wing surface. This structure is called the wingtip slot, which is recognized as a product of bird evolution to improve flight performance. In this paper, numerical simulations based on RANS (Reynolds-averaged Navier–Stokes) equations are conducted to examine and understand the influence of wingtip slots on six wings at Re = 100 000. The overlapping grid method, driven by an in-house UDF (User Defined Function), is used to model the motion of the bionic slotted wings. The motion law of the winglets is improved based on the law extracted from a level-flying bald eagle. Then the aerodynamic force, pressure distribution, vorticity contours, wake stream, and other flow structures of the slotted wings with different layouts were compared and analyzed. The results show a significant increase in aerodynamic force when the slotted wingtips are employed. The maximum lift-to-drag ratio is also improved in our designed wing model with a non-planar wingtip by a maximum of 34% from the base wing. Each winglet works as a single wing due to the existence of slots, with a chordwise pressure distribution similar to that of the main wing. The vortex structures of slotted wings show expressive changes in the tip vortex as compared with the base wing. Additionally, an innovative bionic slotted wing is proposed with a dynamic wingtip that forms varying gaps between winglets. Due to the collective mechanism of aerodynamic interaction among multiple winglets for the innovative wing, it acquires the optimal time-averaged force during a flapping period. As expected, the slotted wingtip reduces the main wingtip vortex intensity and creates weaker vortices. The non-planarity and relative motion of the wingtip strengthen its weakening effect on the wingtip vortex and wake.

On Saturn's six-sided polar jet stream

We derive the nonlinear governing equations for stratified circumpolar atmospheric jet flow in Saturn's upper troposphere. An exact solution is obtained in the material (Lagrangian) framework, by specifying its hypotrochoidal particle paths. The resulting flow pattern presents a striking resemblance to the hexagonal jet stream structure observed near Saturn's North Pole.

Study of the evolution of pulsed plasma under an external longitudinal magnetic field

An experimental study on the role of an external longitudinal magnetic field on the characteristics changes of pulsed plasma stream, produced in argon medium, is carried out at different time spans of its evolution. The spectroscopic observations are time integrated and are carried out at different times of plasma formation for pulsed discharge. This study gives insights into the recombination and diffusion phase of the plasma species in the presence of the magnetic field. The transition of plasma species from a dominant recombination phase to a diffusional phase is well revealed by the density profile during the time evolution. Moreover, the decrease in electron temperature and the increase in electron excitation temperature explain the energy transfer to electrons due to metastable quenching, and the system gradually approaches equilibrium. The magnetic field also affects the transitions of the ionized argon population between different energy levels. It is found that faster decay occurs for transitions of different plasma species to non-metastable states, while the populations of metastable states exist for a longer time. In addition, the time-resolved morphology changes of the plasma stream are also observed by high speed imaging, which shows the flow structure of the plasma stream at different time frames. The imaging of the plasma stream evolution shows the initial ejection of the plasma sheet from the electrode assembly, its detachment, the steady flow, and gradually its nature of dying out.

Structural characteristics of tropical headwater streams draining native vegetation and sugarcane cultivation

There is a great relationship between riparian native vegetation and freshwater ecosystems, influencing the functioning and structure of streams and ensuring the maintenance of ecological integrity and functions, such as bank stability, structural stability, organic matter supply, sediment reduction, and thermal regulation, among others. However, several small streams are inserted in large-scale agricultural areas, suffering pressure due to the expansion of agriculture. One of the monocultures that causes stream degradation in São Paulo, Brazil, is sugarcane, causing changes in riparian vegetation characteristics, bank stability, channel geomorphology and hydraulics, and substrate cover, among others. The objective of this study was to evaluate which structural features are most affected in streams draining sugarcane crops and compare them with streams draining native vegetation, also verifying the seasonal influence on each land use. For this, we applied two protocols that characterize aquatic ecosystems, observing the distinction between land use and seasonality in the studied streams. Our results showed that the relevant and most affected parameters were vegetation cover, presence of riparian forest, bank stability, extent and frequency of rapids, velocity/depth regime, epifauna/substrate cover, alteration in the river/stream channel, and streamflow. PERMANOVA analysis comparing structural importance parameters, among different land uses showed significant difference (p < 0.01; F = 73.74) among land uses and showed no significant difference between seasonal periods for streams draining native vegetation (p > 0.05; F = 0.68) and draining sugarcane cultivation (p > 1; F = 0.82). Thus, our study demonstrated the importance of native vegetation in promoting better structural characteristics of headwater streams.

Multipath ecological influence of an iteroparous fish migration from Lake Biwa to an alluvial stream

Abstract An increasing number of studies describe the ecological influence of semelparous and iteroparous fish migrations on spawning streams. This influence consists of not only the carcasses of spent adults, but also the nutrients that they excrete subsidising stream communities. Given the complex food‐web structure of stream communities, which includes aquatic insects from various functional feeding groups, resource subsidies provided by migratory fishes should influence stream communities through multiple pathways. We evaluated the ecological influence of an iteroparous three‐lips fish (Opsariichthys uncirostris uncirostris) in a alluvial stream by treating fish weirs as large‐scale manipulative field experiments. Between fish‐bearing and fish‐free areas, we compared concentrations of nutrients and fine particulate organic matter (FPOM), and compared densities and stable isotopes of periphyton and benthic macroinvertebrates. The presence of the three‐lips increased the concentrations of ammonium, soluble reactive phosphorus, particulate organic carbon and nitrogen, and chlorophyll‐a densities by up to 2.7‐fold. The δ15N of FPOM and macroinvertebrates during the migratory season were 2.8–7.0‰ higher in the fish‐bearing area, indicating a greater contribution of fish‐derived organic matter. Three‐lips subsidised stream macroinvertebrates through multiple pathways: consumers fed on (1) periphyton increased by the fish nutrient subsidy, (2) fish‐derived organic matter (such as fish carcasses and eggs), and (3) FPOM with fragmented periphyton and fish‐derived organic matter constituents. Results showed that, given the complex food‐web structures in alluvial streams, migratory fish influence stream ecosystems in complex ways. Further studies of the ecological influence of migratory fishes in alluvial streams are needed.

Impact of Mixed-Phase Cloud Parameterization on Warm Conveyor Belts and Upper-Tropospheric Dynamics

Abstract This study investigates mixed-phase cloud (MPC) processes along the warm conveyor belts (WCBs) of two extratropical cyclones observed during the North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX). The aim is to investigate the effect of two radically distinct parameterizations for MPCs on the WCB and the ridge building downstream: the first one (REF) drastically limits the formation of liquid clouds, while the second one (T40) forces the liquid clouds to exist. REF exhibits a stronger heating below 6-km height and a more important cooling above 6-km height than T40. The stronger heating at lower levels is due to more important water vapor depositional processes while the larger cooling at upper levels is due to differences in radiative cooling. The consequence is a more efficient potential vorticity destruction in the WCB outflow region and a more rapid ridge building in REF than T40. A comparison with airborne remote sensing measurements is performed. REF does not form any MPCs whereas T40 does, in particular in regions detected by the radar–lidar platform like below the dry intrusion. Comparison of both ice water content and reflectivity shows there may be too much pristine ice and not enough snow in REF and not enough cold hydrometeors in general in T40. The lower ice-to-snow ratio in T40 likely explains its better distribution of hydrometeors with respect to height compared to REF. These results underline the influence of MPC processes on the upper-tropospheric circulation and the need for more MPC observations in midlatitudes. Significance Statement The diabatic processes occurring in the warm conveyor belt (WCB) of extratropical cyclones impact the jet stream structure at midlatitudes. This study highlights some sensitivity of upper-level dynamics to mixed-phase-cloud-related processes. Comparisons of two different microphysical schemes for mixed-phase clouds shows that the ratio of liquid to solid clouds along the WCB ascents impacts the latent heat release and the radiation. Data from the NAWDEX campaign helps to determine room for improvement for both schemes and point out the need of a better understanding of these processes for an improved prediction of upper-level dynamics.

Mushroom Cultivation Business Development Strategy with BMC Model During Pandemic Covid 19

The COVID-19 pandemic has greatly affected various aspects of people's lives. However, despite all the adversity, several businesses are still able to survive and are expected to continue growing during the crisis. Village-Owned Enterprises (BUMDes) are considered important elements that can play a significant role in awakening and stimulating a sluggish economy in the midst of a pandemic. BUMDes and the mushroom cultivation business unit face several obstacles in marketing, human resources, and increasingly high competition. The type of research used is descriptive with a qualitative approach. This study aims to determine the business development strategy used by the BUMDes Pontang Mushroom Cultivation Business to achieve a new model for business development by using the design of the nine elements of the Business Model Canvas (BMC), which include customer segment, value proposition, channel, customer relationship, revenue stream, key resources, key activities, key partnerships, and cost structure. The results of the SWOT analysis conducted by BMC show that BUMDes could carry out an aggressive strategy. In addition, it also produces a new BMC Design as an improvement alternative choice strategy for customer segments, channels, revenue streams, and customer relationships that can be used for business development, especially during this COVID-19 pandemic.

Mushroom Cultivation Business Development Strategy with BMC Model During Pandemic Covid 19

The COVID-19 pandemic has greatly affected various aspects of people's lives. However, despite all the adversity, several businesses are still able to survive and are expected to continue growing during the crisis. Village-Owned Enterprises (BUMDes) are considered important elements that can play a significant role in awakening and stimulating a sluggish economy in the midst of a pandemic. BUMDes and the mushroom cultivation business unit face several obstacles in marketing, human resources, and increasingly high competition. The type of research used is descriptive with a qualitative approach. This study aims to determine the business development strategy used by the BUMDes Pontang Mushroom Cultivation Business to achieve a new model for business development by using the design of the nine elements of the Business Model Canvas (BMC), which include customer segment, value proposition, channel, customer relationship, revenue stream, key resources, key activities, key partnerships, and cost structure. The results of the SWOT analysis conducted by BMC show that BUMDes could carry out an aggressive strategy. In addition, it also produces a new BMC Design as an improvement alternative choice strategy for customer segments, channels, revenue streams, and customer relationships that can be used for business development, especially during this COVID-19 pandemic.

Constraining the Varied Response of Northern Hemisphere Winter Circulation Waviness to Climate Change

AbstractWhile a large latitudinal displacement of the westerly jet brings about disproportionate socioeconomic impacts over Northern Hemisphere midlatitude continents, it is not well understood as to whether the winter circulation will become wavier or less in response to climate change. Here, using observations and large ensembles of climate models, we show that changes in atmospheric waviness can be estimated from the optimal structures of the westerly jet for wavier circulation, which are obtained from an advection‐diffusion model. Thus, the changes in westerly jet structure in climate models under climate change provide a physical constraint on changes in atmospheric waviness, indicating that the North Atlantic wave activity will experience a robust decline in a warmer climate, while future North Pacific wave activity is obscured by model uncertainty rather than internal variability. These findings highlight the changes to jet stream structure as a constraint for regional circulation waviness in a changing climate.

Structure and local parameters of self-compressed plasma streams in external magnetic field

Abstract The influence of the external axial magnetic field on pinching plasma flows generated by a magnetoplasma compressor (MPC) has been studied using magnetic and electric probes. In the presence of an external magnetic field, temperature measurements show two groups of electrons with different temperatures near the plasma stream core. The external magnetic field leads to a noticeable increase in the electric current in the plasma stream, electron temperature, and the formation of the current-sheet-like structure observed in the MPC for the first time.

Underwater oscillations of rigid plates with H-shaped cross sections: An experimental study to explore their flow physics

In this work, we present a comprehensive experimental study on the problem of harmonic oscillations of rigid plates with H-shaped cross sections submerged in a quiescent, Newtonian, incompressible, viscous fluid environment. Motivated by recent results on the minimization of hydrodynamic damping for transversely oscillating flat plates, we conduct a detailed qualitative and quantitative experimental investigation of the flow physics created by the presence of the flanges, that is, the vertical segments in the plate cross section. Specifically, the main goal is to elucidate the effect of flange size on various aspects of fluid–structure interaction, by primarily investigating the dynamics of vortex shedding and convection. We perform particle image velocimetry experiments over a broad range of oscillation amplitudes, frequencies, and flange size-to-width ratios by leveraging the identification of pathlines, vortex shedding and dynamics, distinctive hydrodynamic regimes, and steady streaming. The fundamental contributions of this work include novel hydrodynamic regime phase diagrams demonstrating the effect of flange ratio on regime transitions, and in the investigation of their relation to qualitatively distinct patterns of vortex–vortex and vortex–structure interactions. Finally, we discuss steady streaming, identifying primary, and secondary structures as a function of the governing parameters.

Bi-Unet: A Dual Stream Network for Real-Time Highway Surface Segmentation

Highway surface segmentation consists of extracting road surface at pixel-level from the surveillance camera view. Since the intelligent traffic event detection task does not require the detection of off-road scene, the segmentation of highway surface is of great demand. However, it is challenging to accurately extract road surface in real time scenarios. To cope with the above issues, Bi-Unet, a dual stream lightweight network is proposed. Firstly, the dual stream structure enhances segmentation performance on the narrow remote end of the highway and preserves the detailed border information. Then, to perform real-time segmentation, a novel lightweight module (LSM) is introduced to lighten the model and provide higher segmentation accuracy. Moreover, to ensure road segmentation for complex scenes, a Road Attention Network (RAN) module is proposed. Lastly, due to the lack of a suitable benchmark dataset serve for the highway segmentation problem, a new large and high-quality segmentation dataset named Highway-Surface-Free (HSF) is proposed in this paper, which is collected from the perspective of highway surveillance cameras under all-day and all-weather conditions. Compared with the state of arts, the extensive experimental results verify that our proposed Bi-Unet achieves the best overall performance on our proposed HSF dataset.