Periodic Fluctuations Research Articles

Behavior of a chain of coupled self-propelled particles with two-dimensional potential and noise

The behavior of an elastic chain of coupled self-propelled particles in a two-dimensional potential with Gaussian colored noise is investigated. The channel and colored noise regulates the directed transport of the system. The chain of particles changes the moving direction with increasing modulation constant of potential. The average velocity of the chain shows periodic fluctuation with increasing phase shift of the potential. Strong coupling between particles inhibits the directed transport speed of the system. Large translation noise intensity is good for the directed transport in the - or , but large self-correlation time inhibits this phenomenon. The effect of the self-propulsion speed is influenced by the modulation parameter of the potential. The elastic chain moves in the when the angle noise intensity is zero. Noise intensity and self-correlation time of the angle noise have a complicated effect on the system.

Modeling and simulation of arc dynamic behavior in Tri-Arc twin wire GMAW

The triple-arc (Tri-Arc) twin wire gas metal arc welding (GMAW) is an innovative approach to twin-wire welding. It establishes two arcs between the welding wires and the workpiece and introduces a third arc, called the “M arc” between the two wires. To theoretically analyze how various welding parameters affect this process, an equivalent circuit method is employed to establish a dynamic mathematical model for Tri-Arc twin wire gas metal arc welding. The welding process is characterized and simulated using MATLAB simulations to analyze variations in current signals and the wire stick-out. The results indicate that the main arc burns in a dynamic equilibrium state with periodic fluctuations, the current gradually decreases over time, and the arc is elongated. These simulation outcomes closely mirror real welding processes.

Interprovincial Transfer Entropy Analysis on Electricity Consumption by Secondary and Tertiary Industries

As electricity consumption is direct feedback of the production and operation state of an industry, there should be links between lead-lag relation in electricity consumption volumes and driving/transferring effects cross regions and industries. In this paper, lead-lag relation between provincial secondary industry (SI) and tertiary industry (TI) electricity consumption volumes is studied based on transfer entropy (TE) theory. Significant TE flow from SI to TI is observed both intra-provincially and interprovincially in a large part of China and periodic fluctuations in electricity consumption curves of SI emerge stably one month ahead of that of TI. It is also found that the curves of SI electricity consumption show more significant correlation with economic cycle in GDP than that of TI. Meanwhile, in both SI and TI cases, Shanghai (SH) manifests noticeable driving effect on other provinces, especially those in Yangtze River Economic Belt. Maximum spanning arborescence topology is built to exhibit direct affecting routes with maximized TE flows of SI and TI from SH to other provinces in the Belt. It is deduced that in SI case it takes stages for the influence from SH to spread while in TI case the influence tends to directly radiate elsewhere. The study attempts to propose an approach to looking through the economy from a perspective of electricity consumption and provide a reference for making industrial strategy.

Optimal Expansion Planning of Energy Hubs: The Future of CHP Sites in Europe

In this article, an open-source expansion planning tool for energy hubs, based on the Python library PyPSA, is presented. The expansion planning optimization uses an operational optimization based on hourly timeseries. The energy hub model contains detailed energy generation, conversion, conditioning, and storage components for electricity, heat, and various chemicals, including CH4, H2, and CO2. For heat, multiple temperature levels are considered. As an example, the tool is used to optimize the expansion planning for a Waste-to-Energy CHP plant and district heating (DH) network in Germany. Techno-economical conditions for 2023 and projected conditions for 2050 are used as inputs. Results are analysed using timeseries and frequency analysis. This provides insight in how each planned component should be used to optimize revenues. The analyses show the importance of using hourly timeseries as input, as certain processes are operated in close alignment with periodic fluctuations in electricity prices or heat demand. Parameters are varied to evaluate the robustness of the investment decisions. The optimization results show that the studied CHP plant could transform to an energy hub, benefiting from synergetic effects when coupling multiple energy sectors using Power-to-X technologies. The tool can be used to assist operators in their investment planning to shape the future of CHP sites in Europe.

Trends in China’s pharmaceutical market during the COVID-19 epidemic

The COVID-19 epidemic has had a significant impact on the Chinese pharmaceutical market, leading to substantial changes in demand, production, supply, and market size. This study aims to analyze the impact on the Chinese pharmaceutical market by examining the evolving market trends during the COVID-19 epidemic. Through relevant literature and data, the following conclusions are drawn: the Chinese pharmaceutical market has undergone significant changes in demand, production, supply, price, and scale due to the epidemic. These factors not only posed considerable challenges to the Chinese pharmaceutical market during the epidemic, prompting the government and enterprises to implement a series of policies to overcome these difficulties, but also presented opportunities and challenges for the development of the Chinese pharmaceutical market. Based on the above analyses, this paper proposes some innovations and suggestions, for example the government should put forward some policies to manage market price fluctuations in some special period, and the state should also cultivate and introduce more innovative talents to help the country innovate in science and technology.

ГЕОДИНАМІЧНИЙ СТАН ЗАКАРПАТСЬКОГО ВНУТРІШНЬОГО ПРОГИНУ ЗА РЕЗУЛЬТАТАМИ ДЕФОРМОМЕТРИЧНИХ СПОСТЕРЕЖЕНЬ У РЕГІОНІ

Background. The relevance of the research is determined by the gradual increase in local seismicity in the region, which occupies a peculiar geographical location, through which oil, gas and product pipelines pass, and in which critical infrastructure facilities are located that may be affected by the underground natural disaster. It is important to have information on the movements of the upper layers of the Earth's crust, their kinematics and dynamics, which significantly affect the stress-strain state of rocks and the release of energy from geomechanic processes. It is also necessary to investigate the influence of the region's geodynamics on the discharge of the stress-strain state of rocks. Methods. The research methodology is to construct time-dependent crustal displacements and compare velocities and accelerations of crustal movements in the intervals of anomalous modern lateral movements of the Earth's crust. The velocities and accelerations of crustal movements are calculated, the kinematics of movements and seismicity of the region are compared. Correlation analysis of the observed series is applied. To solve the tasks, we used the results of observations of horizontal crustal movements in the Oașh deep-seated fault area using a quartz strain gauge with a base of 24.5 m mounted in the adit of the Korolevo urban-type settlement. The seismic data were obtained using digital seismometers operating at the monitoring geophysical station of the Seismicity Department of the Carpathian region of S.I. Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine. Results. The article discusses the geodynamics of the Transcarpathian Inner Trough based on observations of modern lateral movements of the Earth's crust in the Oașh deep-seated fault area, which in 2021 were represented by rock extensions of +12.61x10-7. The physical parameters of geomotion in the region were calculated, the spatiotemporal distribution of local seismicity was established, and the relationship between seismic and geodynamic states in Transcarpathia in 2021 was studied. The variations of displacements of the upper layers of the Earth's crust over the entire period of deformation monitoring observations in Korolevo urban-type settlement (1999–2021) and the temporal distribution of local underground shocks were studied. Conclusions. The analysis of the spatio-temporal distribution of local seismicity and modern lateral movements of the Earth's crust over the entire period of deformation monitoring observations in the Oașh deep-seated fault area has indicated an increase in the seismicity of the region in the intervals of intense crustal movements and the presence of periods of crustal movement fluctuations for 12 years: familiar variable processes (expansion and contraction of rocks, the total magnitude of displacement fluctuations in the region of zero movements) were detected for 2–3 years. The most relevant and important are the periods of 9–10 years following these calm intervals, since during this time earthquakes are recorded and their frequency is also found to be increasing. The intensification of seismicity in the region is observed against the background of general rock extension, which occurs due to the steady age-related crustal movements. At the present stage, the current crustal movements are in a state of rock expansion, and if this trend does not change, an increase in seismicity in the region should be expected.

Numerical study on the hydrodynamic performance and wake dynamics of propulsive wing propulsors with different cross-flow fans

The propulsive wing propulsor (PWP), which means an underwater thruster equipped with a wing, a cross-flow fan (CFF), and a deflector, is capable of generating both horizontal thrust and vertical lift, thus enhancing the maneuverability of underwater vehicles and serving as a propulsion device. The hydrodynamic performance of the PWP is significantly influenced by the blade number it possesses. An unsteady numerical method based on the Reynolds-averaged Navier–Stokes equations was developed to examine the impact mechanism of blade number on the hydrodynamic performance, load fluctuation, and wake evolution of the PWP. The results indicate that as the blade number increases, the hydrodynamic forces, power, and propulsive efficiency of the PWP gradually increase. When the blade number exceeds 26, the performance of the PWP tends to stabilize. Insufficient blades can lead to turbulence in the internal flow of the CFF, intensifying interference between blade vortices, resulting in secondary peaks and frequency-domain bifurcations in hydrodynamics. With an increasing blade number, disturbances to the blade vortices decrease, enhancing the periodicity of PWP hydrodynamic fluctuations, but there may be an increase in high-frequency noise levels. The wake modes of the PWP undergo four transitions: double vortex pair mode, single vortex pair mode, single vortex pair + single vortex mode, and vortex strip mode. Disturbed blade vortices promote the transition of vortex pair shedding modes in the PWP wake, thereby causing variations in the periodicity of PWP hydrodynamics. Excessive amplitude and frequency may lead to structural fatigue damage in the PWP.

Seasonal resilience of temperate estuarine fish in response to climate change

To date, the intricacies and efficacy of how periodic seasonal environmental fluctuations affect fish populations in biogeography in the context of profound climate change remain to be elucidated. Collected monitoring data on fish resources in the temperate estuary provide an excellent opportunity to assess the effects of seasonal environmental fluctuations on populations and functional assemblages under climate change. We first developed a framework for predicting habitat suitability under different climate change scenarios (SSP1-2.6 and SSP5-8.5) for 12 fish populations in the Yangtze estuary by examining the seasonal environmental affinities of temperate estuarine fishes. We then summarized the multidimensional habitat suitability responses (HSRs) of populations and functional assemblages and discussed the possible drivers and mechanisms underlying these changes. The results suggest that the acidity of the Yangtze estuary may decline in the future as the climate warms, endangering the ecosystem that many fish species depend on. Prospective climate change may have an impact on fish population HSRs through redistribution, area changes, and centroid migration of suitable habitats; nevertheless, affinity for environmental factors may be limited to distinguishing patterns of population response in the spring. Fish (5 populations) and functional assemblages (11 assemblages) may exhibit robust adaptations or non-adaptations to climate change when seasons change, given their suitable habitat area. Furthermore, projections indicate that the majority of fish habitat centroids exhibit seasonal responses, migrating northeast in the spring and southeast in the autumn. By decentralizing climate risk to seasonal scales, seasonal resilience in the multidimensional HSRs of several fish populations (5/12) and their functional assemblages (11/16) is revealed for the first time. Efforts to mitigate climate risks and safeguard resources should take these seasonal forecasts and indicative information into account.

Концепція оцінки ергономічної стійкості транспортного потоку великих міст з урахуванням динамічності зміни впливових факторів

The methodological approach of forecasting the congestion of the streets of large cities, taking into account the fluctuations in the density of traffic flows and the speed of movement of cars in the flow, received further development. The methodical approach takes into account fluctuations in the dynamics of the traffic flow in the form of changes in the acceleration of the movement of cars in the flow and fluctuations in changes in the infrastructure of the road environment, which is associated with the number of traffic lights, pedestrian crossings and the number of lanes for the movement of vehicles. Through modeling, it was found that increasing the acceleration values of cars in the stream significantly increases the range of robustness. At low values of acceleration of cars, the reserve of resistance to the formation of traffic jams decreases, which negatively affects the traffic flow, there is a probability of the formation of traffic jams. The presence of fluctuations in the density of the traffic flow and the speed of movement of cars in the flow, due to changes in the acceleration of cars, allows making adjustments to the value of the robustness criterion. Adjustments can be made for different clusters of the road network, for different times of the day, and take into account the period of fluctuations. The dependences of the change in the robustness range of the traffic flow upon changing the infrastructure of the road network are given. It has been established that increasing the number of lanes and simultaneously reducing the number of traffic lights and pedestrian crossings on the controlled cluster significantly increases the stability of the movement of vehicles in the flow. Conversely, reducing the number of lanes, increasing the number of traffic lights and pedestrian crossings on the controlled cluster significantly reduces the stability of the movement of vehicles in the flow. Adjustment of density and movement speed can be performed taking into account the amplitude of oscillations. The concept of modeling and forecasting the stability of traffic flows of large cities to the formation of traffic jams is formulated. The main components of the concept, according to which such an assessment is performed step by step, taking into account the dynamics of changes in influencing factors, are substantiated. The proposed concept differs from the known ones in that it takes into account fluctuations in traffic flow parameters - the density and speed of movement of vehicles over time. Such changes are characteristic of the city's road network during "peak hours".

Hydrometeorological variation in the middle and upper reaches of the Yellow River Basin (1960–2019)

The hydrological and meteorological elements of the Yellow River Basin have undergone fluctuations in response to both climate change and human activities. Understanding its evolutionary trends is essential for the development of effective water conservation measures. Employing linear fitting, Mann–Kendall, and wavelet analysis techniques, this study scrutinizes the trends and periodicity in precipitation, air temperature, and runoff within the middle and upper reaches of the Yellow River Basin from 1960 to 2019. The findings elucidate that temperatures in the middle and upper reaches of the Yellow River have been progressively increasing on an annual basis, while precipitation exhibits periodic fluctuations, and annual runoff demonstrates a declining trajectory. Sudden changes in runoff and temperature transpired in the years 1985 and 1997, respectively, whereas sudden changes in annual precipitation occurred in 1961 and 2012. On an annual scale, the influence of temperature and precipitation on runoff displays no evident prominent cycle. Notably, a significant negative correlation exists between temperature and runoff, with the noteworthy impact of temperature on runoff primarily manifesting in the 6-year sub-cycle spanning 1986 to 1992, as well as the 9-year sub-cycle encompassing 1963 to 1972. Conversely, precipitation and runoff exhibit a significant positive correlation. The substantial effect of precipitation on runoff is mainly concentrated within the 9-year sub-cycle from 1963 to 1972 and the 8-year sub-cycle from 1972 to 1980. Precipitation emerges as the primary driving force behind watershed runoff. In essence, the study's outcomes unveil the implications of climate change on runoff within the middle and upper reaches of the Yellow River Basin, thereby offering pertinent insights for effective water resource management strategies in the face of evolving climatic conditions.

Unsteady Flow Characteristics in a Centrifugal Compressor

Abstract The geometry of the vortex shell significantly affects the non-axisymmetric flow in centrifugal compressors. This study explores the static pressure characteristics of the vortex shell through experimental data and numerical analysis using finite element software. Findings indicate that the vortex tongue region critically influences the cascade structure. At high flow rates (0.40 kg/s), flow field parameters at the blade and vortex shell inlets alter markedly near the tongue side. Conversely, at lower velocities (0.26 kg/s), flow distribution at the blade inlet becomes more uneven, and changes in the inflow angle are more pronounced. Additionally, blade pulsation intensifies at higher velocities, and the jet wake vortex exhibits structural variations at different velocities. High-pressure fluctuations are notably transmitted upwards through the vortex shell, with periodic fluctuations affecting the impeller load. These changes significantly impact the flow field under various operating conditions.

Mechanism Analysis of Thermal-Induced Periodic Fluctuations in Electro-Optic Sensor

Mechanism Analysis of Thermal-Induced Periodic Fluctuations in Electro-Optic Sensor

A New Closure Assumption and Formulation Based on the Helmholtz Decomposition for Improving Retrievals for Vortex Circulations from Single-Doppler Radar Observations

Abstract Doppler weather radars are powerful tools for investigating the inner-core structure and intensity of tropical cyclones (TCs). The Doppler velocity can provide quantitative information on the vortex structure in the TCs. The generalized velocity track display (GVTD) technique has been used to retrieve the axisymmetric circulations and asymmetric tangential flows in the TCs from ground-based single-Doppler radar observations. GVTD can have limited applicability to asymmetric vortices due to the closure assumption of no asymmetric radial flows. The present study proposes a new closure formulation that includes asymmetric radial flows, based on the Helmholtz decomposition. Here it is assumed that the horizontal flow is predominantly rotational and expressed with a streamfunction, but limited inclusion of wavenumber-1 divergence is available. Unlike the original GVTD, the decomposition introduces consistency along the radius by solving all equations simultaneously. The new approach, named GVTD-X, is applied to analytical vortices and a real TC with asymmetric structures. This approach makes the retrieval of axisymmetric flow relatively insensitive to the contamination from asymmetric flows and to small errors in storm center location. For an analytical vortex with a wavenumber-2 asymmetry, the maximum relative error of the axisymmetric tangential wind retrieved by GVTD-X is less than 2% at the radius of the maximum wind speed. In practical applications, errors can be evaluated by comparing results for different maximum wavenumbers. When applied to a real TC, GVTD-X largely suppressed an artificial periodic fluctuation that occurs in GVTD from the aliasing of the neglected asymmetric radial flows. Significance Statement In tropical cyclone (TC) wind retrievals from single-Doppler weather radar observations, closure assumptions are required for the retrieval equations. The present study proposes a new closure allowing asymmetric radial winds and improving retrievals for TC winds in the previously developed technique. The relative error of the axisymmetric tangential wind in idealized vortices from the new approach is less than 2% at the radius of the maximum wind speed. In applying to a real TC with an elliptical eyewall, we found that the new approach can largely suppress an artificial evolution of the tangential winds in the previous retrieval technique.

Numerical simulation of financial fluctuation period based on non-linear equation of motion

Numerical simulation of financial fluctuation period based on non-linear equation of motion

Morning and Evening Exercise with or without High-Pressure Intervals have Different Effects on Controlling Blood Sugar and Glucose Fluctuations in People with Type 1 and Type 2 Diabetes

Summary: Exercise is recommended for the treatment and prevention of type 2 diabetes. Also, to control and reduce glucose fluctuations in people with type 1 diabetes. However, the most appropriate time and the most effective intensity of exercise is still unknown, and various studies provide different results and different recommendations, and none of the studies provide a comprehensive and practical result. We conducted our studies to examine the results and determine the effect of time and intensity of exercise on blood sugar control and glucose fluctuations during the day. Methods: search in PubMed and Google Scholar with keywords morning, evening, type 1 and 2 diabetes, exercise, interval, periodic, aerobic, and glucose and blood sugar fluctuations were performed. A total of 31 articles were reviewed and finally, 10 articles that were most related to each other or had complementary information were selected. Conclusion: HIIT exercises are useful for type 2 diabetes, but they are recommended for type 1 diabetes with less pressure. Morning exercise increases glucose and evening exercise is applicable for type 1 and 2 diabetes.

Mapping the relationship between the temperature gradient of CRTS Ⅲ slab track on bridge and rail deformation in high-speed railways

Temperature gradient is an important factor affecting the periodic rail deformation of CRTS Ⅲ and the running stability of high-speed trains. The Comprehensive Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) method is employed for the analysis of test data in site from CRTS III slab tracks on high-speed railway bridges. The correctness of the coupling model has been validated through data on-site. To analyze the mapping relationship between the temperature gradient of the CRTS Ⅲ slab track on the bridge and rail deformation in high-speed railways, a rail-slab track-bridge thermal coupling model was established, and the rail deformation distribution characteristics of the slab track on the bridge under the complex temperature gradient load were calculated. Furthermore, a prediction model of rail deformation under the action of the complex temperature gradient was proposed. The study results showed that the intrinsic mode function (IMF) decomposed by the CEEMDAN method reflects the sensitive wavelength of track irregularity and quantitatively describes the corresponding relationship between amplitude and seasonal temperature. In the measured data, the maximum amplitude of rail deformation caused by temperature differences in different seasons was 1.99 mm, reflecting the significant impact of temperature gradient on the additional track irregularities on the bridge. Under the action of the temperature gradient, the rail deformation of CRTS Ⅲ slab track on the bridge is the superposition of periodic sinusoidal fluctuation of the track and parabolic fluctuation of the simply supported beam. This study could provide a new method for predicting rail deformation and controlling track smoothness, so as to improve the stability and operation efficiency of trains.

A phase change material based annular thermoelectric energy harvester from ambient temperature fluctuations: Transient modeling and critical characteristics

Annular thermoelectric power generator has been increasingly considered in application of ambient energy harvesting owing to the advantages of simple structure and no pollution. To improve thermal stability and energy harvesting performance of this system, the latent heat of phase change materials to improve thermal management and the high thermal conductivity of the heat sink to enhance heat transfer with the ambient are harness to annular thermoelectric power generator. Motivated by this, a phase change material based annular thermoelectric energy harvester (PCM-ATEH) with fins is developed for ambient energy harvesting and its three-dimensional transient model is also built up through jointly with thermo-electric and phase change processes. This paper considers the influence of key parameters such as temperature fluctuation amplitude, temperature fluctuation period, height ratio of PCM and thermoelectric generator (TEG) and melting temperature on liquid fraction, temperature difference, voltage and power density. Moreover, the comparison of PCM-ATEH and PCM based thermoelectric energy harvester (PCM-TEH) with/without fins is further conducted in this study to explore thermal management and energy harvesting performance. The energy harvesting characteristics of PCM-ATEH with fins is developed concerning the combination of power generation of TEG and melting process of PCM. Based on the results, it is found that the temperature difference and power density of PCM-ATEH with fins vary periodically with the sinusoidal temperature boundary, and results show that increasing temperature fluctuation period is not always feasible. Additionally, the comparative results indicate that the peak power density and energy efficiency of PCM-ATEH with fins are increased by 0.126 W/m2 and 0.02 % compared with PCM-TEH with fins, and increased by 0.195 W/m2 and 0.041 % compared with PCM-ATEH without fins. The results of energy harvesting characteristics show that a maximum of 0.77$ per watt can be reached to power generation cost of PCM-ATEH with fins. This paper can provide theoretical guidance for thermal management and energy conversion of energy harvesting system.

Fluid analysis of the cavitation of the microsegment gear pump operating at high-pressure condition

To investigate the cavitation of the microsegment gear pump and its effect on the performance of the gear pump, the gear equations of the microsegment gear for the pump were given, the cavitation mechanism was described, and the dynamic cavitation model was derived. The fluid analysis of the microsegment gear pump was carried out using the computational fluid dynamics software (Fluent), and the evolution of cavitation and its effect on the outlet flow characteristics were investigated. The results show that: the vortex occurred at the back edge of the microsegment gear pump suction chamber teeth and the top of the teeth, thus producing cavitation; the cavitation presented periodic formation-development-disappearance of the process; cavitation led to increased outlet flow fluctuations and pressure pulsations, and also led to a decrease in the average value of outlet flow and average value of outlet pressure. The periodic cavitation led to the periodic fluctuation in outlet flow and pressure. At the same time, cavitation also caused a decrease in the total head of the microsegment gear pump. Cavitation in the microsegment gear pump increased with increasing the speed and decreasing the suction pressure.

Forecast of Subway Inbound Passenger Flow based on LSTM Model and BP Neural Network

Passenger flow prediction for rail transit is an extremely important research topic. This paper constructs a long-short-term memory model, and proposes a simple optimization method. At the same time this paper constructs a backpropagation neural network model and adjusts the size of the hidden layer through testing. Within 15 days, swipe card data from a randomly chosen tube station in a city is subjected to resampling, normalization, and other data preparation techniques. The processed data is then split into an 80% training set and a 20% test set. The root-mean-square error test analysis is carried out on the three types of models constructed to judge the fitting effect of the data. The conclusion is that the BP neural network model is relatively easy to build a shallow network structure, which is typically less than or equal to 3. Additionally, the data fitting effect outperforms both the LSTM model and the straightforward optimization approach. Especially for passenger flow fluctuations in a short period of time, the BP neural network can have good prediction ability.

The Risk of Water Quality Deterioration with Urban Flood Control—A Case in Wuxi

There is a demand for flood control in densely populated river network areas. Therefore, small floodgates are used for long-term and rapid water flow regulation in such contexts. However, people often disregard these floodgates’ potential interference with the natural water environment. This study focused on an urban floodgate-controlled reach and monitored the monthly data of four main pollutant indicators (TN, TP, CODMn, and NH3-N) from 2016 to 2018 at six fixed sampling points (S1–S6). The difference analysis and cluster analysis results indicated that floodgate adjustments were the dominant driving factor of water quality changes in the reach, with pollutant concentration differences observed between the floodgate opening and closing periods. The results of the Canadian Council of Ministers of the Environment Water Quality Index evaluation showed that the water quality of the floodgate-controlled reach was categorized as “marginal” or “poor”. It is particularly important to note that the concentration of nitrogen compounds exceeded the allowable limits. The results of the Mann–Kendall trend and time series analyses revealed an overall upward trend in NH3-N concentration and a localized upward trend in TP concentration and presented periodic concentration fluctuations of four pollutants (TN, TP, CODMn, and NH3-N). This study highlights that flood control management using small floodgates can pose a risk of deteriorating water quality. Therefore, it is necessary to develop scientific water quality management methods.