Maximum Flow Value Research Articles

Non-Conservative Maximum Flow by Centiles-Method in Uncertain Network

The flow maximization problem being a leading problem in network optimization is widely studied with many applications. In this work, we find the maximum flow pulled out from the source and sent to the sink using the uncertainty theory. We develop a flow function to get maximum flow for the network having uncertain arc capacities and sufficient storage capacities at the intermediate vertices. The centiles-method is used to find the maximum flow value and an algorithm is proposed to get non-conservative maximum flow. The result is also illustrated by an example. The flow values are compared graphically to see the dominance of the non-conservative maximum flow over the conservative maximum flow.

Prospective observational study on the efficacy and tolerability of a complex of phytochemicals versus dutasteride in the treatment of Lower Urinary Tract Symptomps due to Benign Prostatic Hyperplasia.

The aim of our study was to treat 2 similar groups of patients suffering from BPH: one group with a complex based on phycocyanin, PEA and selenium; the other group with dutasteride. So the effectiveness of these treatments was checked, especially regarding the improvement of LUTS and the reduction of PSA and prostate volume. We included 104 patients in the study. All patients aged between 50 and 70 years, PSA values between 4 and 10 ng/ml, prostate volume calculated by transrectal ultrasound between 50 and 70 cc, flowmetry with maximum flow value greater than or equal to 10 ml/s, no suspicious nodules on DRE, no suspicious lesions on MRI (PI-RADS 1-2), negative previous prostatic biopsies or never bioptied, moreover absence of diabetes mellitus or chronic renal failure (blood creatinine >2 mg/dl). We considered: -Group A of 54 men who used the complex; -Group B of 50 patients treated with dutasteride. Then we controlled all patients 6 months after starting therapy, considering the following parameters: PSA, prostate volume, flowmetry. Our results showed that both dutasteride and complex decreased PSA levels (both had a p<0.0001), with a more significant contribution of dutasteride (mean decrease of -2.743 ng/ml vs -0.971 ng/ml). Uroflowmetry also improved with both ( p<0.0001) with a mean increase in maximum flow of urine of + 3.03 ml/min for the former and + 13.02 ml/min for the latter. Lastly, dutasteride proved to be highly effective on reducing the prostate volume on TRUS (- 22.14 ml, p<0.0001) compared to Ficoxpea, which showed a mean decrease of - 10.04 ml (p<0.0001). Moreover the consistent reduction in prostate volume obtained through the use of dutasteride proved to be more intense than the one obtained by using the complex even in statistical analysis (p<0.0001). Both Ficoxpea and Dutasteride showed reduction of PSA values after 6 months of treatment. The complex based on phycocyanin, PEA and selenium showed a statistically significant improvement in urinary flow, while dutasteride acts more on the volume of the prostate. However, the natural complex is a product with good efficacy on the phlogistic component and does not have the side effects of dutasteride (e.g. gynecomastia, reduced libido). Therefore, we believe it can be used by a large part of the population, in order to reduce LUTS and PSA and improve urinary flow, without side effects.

ТЕНДЕНЦИИ МНОГОЛЕТНИХ ИЗМЕНЕНИЙ СТОКА ОСНОВНЫХ РЕК, ФОРМИРУЮЩИХСЯ В ЖАЙЫК-КАСПИЙСКОМ ВОДОХОЗЯЙСТВЕННОМ БАССЕЙНЕ

Studies were conducted aimed at the trends in the flow of the main rivers of the Zhaiyk-Caspian water basin. The average annual dynamics of river flow for a long period, their 5-year moving averages, joint tables of air temperature and precipitation values with river flow, as well as long-term dynamics of characteristic (highest, winter and lowest in open channel conditions) water flows were considered. According to the results of the research, two periods were distinguished: from 1940 to 1973 (conditionally natural) and from 1974 to 2020. (modern). In both periods, there is a tendency to reduce runoff against the background of an increase in air temperature, precipitation trends are multidirectional. Since the 1970s, there has been a decrease in the amplitude of fluctuations in annual runoff, since the 2000s there has been a decrease in both the amplitude of fluctuations and the values of maximum water flow. In the values of the lowest summer-autumn and winter water flow, on the contrary, there is a tendency to increase, which began in the late 1980s – early 1990s. For small rivers and temporary watercourses, the summer-autumn and winter periods are periods of maximum runoff depletion, during which drying and freezing phenomena (zero runoff) are characteristic.

Application of Network Reconstruction Algorithm to Compute Maximum Flow for Water Supply Network: A Case Study of the City of Bulawayo, Zimbabwe

Determining the maximum flow value in Water Supply Networks (WSN) is a common problem that is being faced by many cities during and after designing of WSN. In this article, the network reconstruction (NR) algorithm is applied to compute the maximum flow value for the city’s WSN based on the actual data. The city of Bulawayo has been selected for the following reasons, availability of research data, the city is facing severe water shedding and several studies have focused only on other issues such as alternative water sources, leakage detection and demand forecasting. The goal of this study is to determine the maximum flow value from the sources to the reservoirs. The results have revealed that the computed maximum flow value is within the estimated range of 110,000 cubic meters to 190,000 cubic meters. Dam sensitivity analysis were considered to determine the sources to give maintenance priority before the rain season. Several recommendations were suggested to improve the water supply situation.

Study Of Asphalt Characteristics Using Fly Ash as a Substitute For Sand In Concrete Asphalt (AC – WC) Using The Marshall Test (RSNI M-01-2003) and Test Standards Specifications For Bina Marga Specifications 2018 Revision 2

Utilization of fly ash which is part of the residue from burning coal for power plants (PLTU), where the combustion products have the same size as sand. Asphalt concrete is a type of construction pavement consisting of a mixture of asphalt and aggregate, either with or without added materials. This research aims to determine the characteristic values ​​of asphalt using fly ash as a substitute for sand in AC – WC asphalt concrete with mixed variations of 25%, 50% and 75%. From the research results, the AC-WC mixture used according to the standard, namely the condition of 5.5% asphalt content, obtained a stability value of 1580kg, a VFB value of 79.00%, a VMA value of 15.50%, a VIM value of 3.40%, a MQ value of 550kg/mm ​​, flow value 2.90mm and density value 2.35. Tests with mixture variations of 25%, 50% and 75% obtained a maximum stability value of 1706.5kg at a variation of 25%, a maximum flow value of 3.54mm at a variation of 75%, a maximum VIM value of 6.90% at a variation of 75%, a maximum VMA value 17.68% at 75% variation, maximum VFB value 84.89% at 25% variation, maximum density value 2.38 at 25% variation and MQ value 605.33kg/mm ​​at 25% variation. From the results of a study of the characteristics of asphalt using fly ash as a substitute for sand in AC-WC concrete asphalt with a variation of 50% which meets the requirements of the 2018 General Specifications Revision 2.

A phase II study of plerixafor combined with whole brain radiation therapy (WBRT) for patients with newly diagnosed glioblastoma.

2075 Background: Plerixafor inhibits the binding of stromal cell-derived factor 1 (SDF-1a / CXCL12) to its receptor on CD11b+ monocytes, inhibiting vasculogenesis and tumor recurrence in preclinical models. An early phase trial demonstrated that Plerixafor administration decreased cerebral blood volume (CBV) within the irradiated field of glioblastoma patients, and that the majority of recurrences occurred outside of the irradiated field (Thomas R. et al, Clin Cancer Res). This follow up study investigates the efficacy of Plerixafor in combination with WBRT, with the hypothesis that widening the radiation therapy (RT) field with WBRT may reduce out-of-field tumor recurrence and improve survival. Methods: This was a Phase II, open-label, non-randomized, single-arm trial.Adults between 18-75 years old with newly diagnosed high grade glioma as defined by WHO 2016 criteria and KPS ≥ 60 were eligible for enrollment. Patients underwent maximal safe resection followed by 6 weeks of concurrent radiation therapy and temozolomide (TMZ). Of note, modifications to the conventional treatment paradigm included completing 30 Gy of standard intensity-modulated RT followed by 30 Gy of WBRT, as well as completing a 4-week continuous infusion of Plerixafor dosed at 400 µg/kg/day. Patients then started adjuvant TMZ after completing Plerixafor. Primary endpoint was 6-month progression free survival (PFS6) after chemoradiation. Secondary endpoints included median overall survival (mOS), adverse events (AEs), MRI-based patterns of recurrence, and neurocognitive outcomes measured by the Trail Making Test, Controlled Oral Word Association Test, and the Hopkins Verbal Learning Test. Additionally, maximum arterial spin labeling-cerebral blood flow (ASL-CBF) values of primary lesions were compared over various time points during the study. Results: 14 of 17 enrolled patients completed the Plerixafor infusion, and all 17 patients completed WBRT. Median age was 57 years. 15 patients (88.2%) were IDH wildtype and 13 patients (76.5%) were pMGMT unmethylated. 13 patients (76.5%) underwent gross total resection, 2 (11.8%) underwent subtotal resection, and 2 (11.8%) underwent biopsy only. The PFS6 was 91.7%. The mOS was 15.11 months. 3 patients discontinued Plerixafor early due to rash (n=1), rising creatinine (n=1), or worsening confusion and agitation (n=1). Common Gr2 treatment-related AEs included alopecia (n=4), nausea (n=4), and vomiting (n=2). 1 patient had Gr3 alopecia. There were no Grade 4/5 AEs. 80% of patients scored worse on their neurocognitive assessments at 6 months compared to screening. ASL-CBF values of primary lesions appeared relatively stable throughout the study. Conclusions: The combination of Plerixafor and WBRT did not improve mOS compared to the original study using focused RT only. There was an overall decline in neurocognitive performance over the course of the study. Clinical trial information: NCT03746080 .

Estimating rainfall-runoff parameters for ungauged catchments: a case study in Turkiye

ABSTRACT Determining water yield and flood discharges in catchments is a vital aspect of hydrology. This entails considering precipitation and runoff as key hydrological parameters. Constructing infrastructure like hydroelectric plants and regulators over streams necessitates continuous, accurate flow, and meteorological observations spanning at least 25 years. However, in developing nations, economic factors often impede such observations. This study proposes a method to estimate peak rainfall and flow values for ungauged basins with varying return periods by utilizing from gauged basins and spatial variables. Flood calculations were carried out for the ungauged Rabat River basin. In this study, regional flood frequency analysis was carried out using the flow values of the flow gauging stations neighboring the basin. In addition, maximum flow values were calculated using Moscus and the DSI synthetic method. Two- and three-parameter distributions were used to estimate 50-, 100-, 200- and 500-year flood return values at stations with observation periods ranging from 15 to 64 years. Kolmogorov–Smirnov and Probability Line Correlation coefficient (Chi-square) tests were applied to check the suitability of these distributions and the most appropriate distributions were found. This yielded an estimation for the flow values of the Rabat River, indicating the method's reliability for forecasting runoff-rainfall in the ungauged basin.

A solution for abstract decision problems based on maximum flow value

An abstract decision problem is an ordered pair where the first component is a nonempty and finite set of alternatives from which a society has to make a choice and the second component is an irreflexive relation on that set representing a dominance relation. A crucial problem is to find a reasonable solution that allows to select, for any given abstract decision problem, some of the alternatives. A variety of solutions have been proposed over the years. In this paper we propose a new solution, called maximum flow value set, that naturally stems from the work by Bubboloni and Gori (The flow network method, Social Choice and Welfare 51, pp. 621–656, 2018) and that is based on the concept of maximum flow value in a digraph. We analyze its properties and its relation with other solutions such as the core, the admissible set, the uncovered set, the Copeland set and the generalized stable set. We also show that the maximum flow value set allows to define a new Condorcet social choice correspondence strictly related to the Copeland social choice correspondence and fulfilling lots of desirable properties.

An experimental comparison of 3D velocity components around single and twin piers installed in a sharp bend under the influence of upstream implemented vanes

To reduce the trend of scouring, understanding the flow pattern around the bridge piers is necessary. By using hydraulic structures such as submerged vanes, it is possible to alter the flow pattern of water, thus scouring process and sediment transport in riverbeds. Since the scouring mechanism for pier groups differs from single pier, experiments were conducted in a 180° sharp bend channel in the laboratory to investigate the flow pattern around pier group and single pier under the influence of 25% submerged vanes. Furthermore, a comparison was made between the flow patterns in single pier and pier group conditions. Three-dimensional velocities along the bend and different depths were measured using an Acoustic Doppler Velocimeter (ADV(. The results suggest that the maximum vorticity value at the apex position of the bend (location of piers) and the maximum secondary flow value, at the distance between the piers and the vanes, were found to be, 0.15 and 0.89, respectively. In the twin pier experiment, the maximum Reynolds shear stress value τyx\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ au }_{yx}$$\\end{document} decreased by about 36%, and the minimum value decreased by about 49% compared to the single pier experiment. The final results indicated that using submerged vanes obtained the maximum τyx\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ au }_{yx}$$\\end{document} and τzx\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ au }_{zx}$$\\end{document} near the vanes. Near the bed and mid-depth of the water flow, the geometric location of the maximum velocity also occurred around the vanes in both experiments. Therefore, the vanes are important in altering the water flow pattern, diverting the flow from around piers and consequently reducing the bridge pier scouring.

The Hourly Peak Coefficient of Single-Family and Multi-Family Buildings in Poland: Support for the Selection of Water Meters and the Construction of a Water Distribution System Model

Taking care of water resources and minimizing water losses in water supply networks requires a broad approach to identifying and neutralizing operational problems. The correct selection of water meters to minimize apparent losses requires knowledge of the characteristic flows that may occur in the facility to which water is supplied. The research aimed to develop tools in the form of mathematical models and water consumption curves along with hourly water consumption coefficients to facilitate the process of selecting water meters for engineers and creating computer models of water supply systems. The research involved monitoring the flow of 76 single-family and multi-family buildings in four towns in Poland, followed by data analysis and development of tools supporting the selection of water meters and the construction of computer models of water distribution networks. High correlation coefficients of the studied variables indicate the results’ usefulness. Four models were developed to determine the maximum flow values in multi-family buildings (three models) and single-family buildings (one model) in the range of water meter diameters DN15-DN40. Characteristics of the average hourly peak coefficient (HPC) values were also developed, along with the range of changes in HPC values for single-family and multi-family buildings.

Quantum optimization methods in water flow control

This paper examines the problem of optimizing water flow control in order to minimize costs, represented as the square of the water flow. This takes into account restrictions on this flow, such as the maximum flow value. To solve this problem, two optimization methods are used: the classical optimization method Sequential Least SQuares Programming (SLSQP) and the quantum optimization method Variational Quantum Eigensolver (VQE). First, the classical SLSQP method finds the optimal control (water flow) according to the given cost function and constraints. Then the obtained result is refined using the quantum VQE method. The quantum method uses an ansatz to represent the quantum circuit and a Hamiltonian to describe the system. The problem comes down to finding the minimum eigenvalue of the Hamiltonian, which makes it possible to determine the optimal parameters of the quantum circuit that minimize the cost of controlling the water flow. Thus, the proposed approach combines the strengths of classical and quantum optimization to effectively solve the water flow control optimization problem.

Prioritized Max-FlowLoc for Evacuation Planning

From different disasters such as earthquakes, flooding, landslides, hurricanes, blizzards, etc., thousands of people have lost their lives and millions of people have to be rescued each year. To reduce the losses from different disasters, appropriate emergency plannings are essential. The allocation of facility in an appropriate location of prioritized network are evenly used in such plannings. The prioritized maximum flow problem is to obtain the maximum flow in a network by taking a predetermined leaving pattern at the sources and/or reaching pattern at the sinks. But placing the facility on an arc, which is a very important task to supply the basic needs of the evacuees, reduces the arc capacity so that the maximum flow value in the network may be reduced. Here, we introduce the prioritized maximum static and dynamic flow location (FlowLoc) problems in a single source and multi-sink network. The mathematical models are given for both single and multi facility problems. The polynomial time algorithms are presented in single facility cases. After proving the $\mathcal{NP}$-completeness, the polynomial-time heuristics are presented for optimal or near optimal solutions in case of multi-facility cases.

AMFC: A New Approach Efficient Junctions Detect via Maximum Flow Approach

In this study, max flow analysis processes are carried out with a graph theory-based approach that can be used in optimizing the traffic load in transportation networks. The data used in the study consists of 2 years of vehicle number data consisting of 438 million vehicle passes of a real city. Bottleneck points affecting traffic flow, maximum flow values, and effectiveness values of traffic generating and attracting locations were determined in the uniquely created transportation network. The Ford-Fulkerson algorithm was used to determine the maximum flow and bottleneck road connections in the designed transportation network. According to the maximum traffic flow to the junction point, the most effective junction points were determined by the PageRank algorithm. In addition, a unique algorithm is presented in the study that determines the effective intersection points that transfer vehicle traffic at maximum capacity to all junction points according to the maximum demand capacity data.

Calculation of Proper Time of Concentration for Drainage Design in Construction Projects for Urban Development

The design and construction of a proper drainage system are important for any urban development project, small or big. Hydrological and hydraulic calculations are used to design the drainage systems. The calculation of peak flow is one of the common hydrological methods applied to determine the drain sizes for all construction projects. Peak flows and hydrographs can be calculated using several techniques. In order to calculate the peak flow, the design rainfall duration has to be appropriate, which will reflect the critical storm duration. The critical storm duration, on the other hand, depends on the time of concentration (tc) of the catchment. However, most of the equations for tc available in the literature are empirical. At least 23 equations could be traced in various references, which consist of different geophysical and other hydrological parameters. This paper is intended to explain the importance of the proper use of tc to calculate peak runoff flow for construction projects, as accurately as possible. A review of the existing methods used to calculate the time of concentration revealed inconsistencies among a few methods found in the literature. The correct value of the time of concentration (tc) is important for the application of the Rational Method, as the value of tc helps the designer assume the storm duration critical to get the maximum peak flow value. If the critical storm duration is not used in the Rational Method, the drain will be undersized, and the overflow of the storm runoff may happen. Therefore, ample attention should be given to the calculation of the time of concentration to ensure the safety, economy, and sustainability of the drainage system in any development project.

Analisis Karakteristik Lalu Lintas Terhadap Tingkat Pelayanan Jalan pada Jalan Komodo, Ruteng, Kabupaten Manggarai

Komodo Street is a national road network that connects the regencies of Manggarai and West Manggarai. Along the Komodo Street there are several shopping centers, restaurants and houses of residents who do not have adequate parking space. The existence of pedestrians crossing and the activity of vehicles going in and out of the road affect the level of service. The purpose of this study is to determine the quantity of traffic flow, capacity, and level of service on Komodo Street. The method used in this study is the quantitative analysis based on the PKJI 2014. The analysis of the value of the maximum traffic flow at Point 1 yielded a maximum of 1.103 light vehicle units/hour and a minimum of 519 light vehicle units/hour. At Point 2, the maximum traffic flow value is 1.085 light vehicle units/hour, while the minimum value is 568 light vehicle units/hour. At Point 3, the maximum traffic flow value is 1.077 light vehicle units/hour and the minimum is 558 light vehicle units/hour. At Point 4, the maximum traffic flow value is 1.068 light vehicle units/hour and the minimum is 612 light vehicle units/hour. The maximum capacity value for Point 1 is 2.105 light vehicle units/hour, while the minimum capacity value is 2.061 light vehicle units/hour. The maximum capacity value for Point 2 is 2.105 light vehicle units/hour, and the minimum capacity value is 1.953 light vehicle units/hour. The capacity value for Points 3 and 4 is 2.105 light vehicle units/hour. The level of service values for all points vary at any time, namely B and C.

A reverse chain search algorithm for the resource constraint in deep space detectors

Deep space exploration activities can effectively promote the development and application of space technology, which holds significant scientific and strategic value. Detectors operating in deep space are of long mission periods and substantial distance from Earth, posing challenges in timely resource replenishment. Moreover, scheduled missions may face external uncertainties, hindering their smooth execution. Therefore, resource constraint processing strategies that possess dynamic adjustment capabilities play a crucial role in ensuring the successful execution of deep space detectors. Existing methods mainly focus on studying fixed mission sequences, and the efficiency of planning methods is not high. Specifically, the single uncertainty is only considered, and there is a lack of detection and processing mechanisms, rendering the requirements of deep space detectors inadequate. In this paper, we propose a reverse chain search algorithm, aiming to efficiently plan missions subject to resource constraints and let the mission sequence to possess a certain degree of dynamic repair capability. The results have demonstrated that the resource allocated to each mission is within the resource value range. Compared with the classic algorithm, the proposed algorithm has fewer iterations and whose maximum flow value is accurate. Meanwhile, the potential resource constraints problem during execution can be alerted with the detection and warning system. The missions that were warned are repaired by a dynamic resource repair system, and the proposed algorithm is of higher efficiency and a certain ability to resist external uncertainties. Overall, this paper lays a solid foundation for the processing of resource constraints for deep space detectors.

Research on the impact of air-blowing on aerodynamic drag reduction and wake characteristics of a high-speed maglev train

The maglev train fills the speed gap between ground transportation and airplanes. However, the increasing train speed results in greater energy losses due to increased aerodynamic drag, impeding the green and sustainable development of high-speed railways. This study employs the numerical simulation method to explore the effects of installing air-blowing slots on the surface of the TR08 maglev train's tail car and blowing air along three different directions at two different speeds on drag reduction and the characteristics of the wake flow field. Among them, only blowing air along the streamwise direction at speeds of 12 m/s (X12) and 24 m/s (X24) shows drag reduction effects of 2.06% and 6.53%, respectively. However, considering the energy efficiency, only X12 achieves a net energy saving of 58.96%, while the energy consumption by blowing air and saving by reducing drag in X24 are roughly balanced. Air-blowing reduces the aerodynamic lift of the tail car (Cl), with blowing air along the perpendicular direction at 24 m/s (Z24) reducing the Cl by 99.57%. Additionally, Z24 reduces the maximum velocity value of the train-induced air flow (Usmax¯) by 61.91%. The research findings provide new insight and data support for the development of blowing/suction drag reduction techniques.

Spatial Modeling through GIS Analysis of Flood Risk and Related Financial Vulnerability: Case Study: Turcu River, Romania

The present study is part of the context in which Romania adopted the European Parliament Directive 2007/60/EC on flood risk assessment and management. Therefore, the aim of this research is to assess the risk induced by a hydrological hazard, expressed by a financial value estimation, for the Turcu River in the northern sector of the Bran–Dragoslavele transcarpathian corridor (Romania), an important tourist axis where the pressure on land has increased considerably. As a result, the intra-village areas of Moieciu de Sus, Cheia, Moieciu de Jos, Bran and Tohanu Nou have also expanded into areas vulnerable to flooding. There are currently no studies on the areas potentially affected as well as the extent of the possible damage. For this reason, we proceeded to model the water level corresponding to the maximum flow value with a probability exceeding 1%, using HEC-RAS and ArcGIS software. The results of the implementation of the spatial analysis model resulted in the delineation of the floodplain and the assessment of the potential financial loss related to the minimum market value of the land with the related real estate infrastructures. The research reveals that in the 1% band area (78.7841 ha) with water depth &gt; 0.5 m, more than 433 infrastructures are at high risk of flooding, most of them with high real estate value, i.e., 5.61 km of roads for which a cost of EUR 3,402,666.90 was calculated for restoration. A knowledge of financial vulnerability to flooding becomes important for the community; local authorities involved in making decisions for insuring real estate at risk and planning/managing investments work to prevent/combat the effects of flooding.

Reconstructing parameters of the Holocene paleofloods in alluvial lowland river valleys – An example from the Bug valley (East Poland)

One of the ways to improve the accuracy of hydrological forecasts is to extend the data strings with the parameters of the maximum flows in the river from the period preceding their instrumental recording. The reconstruction of such parameters is difficult in the case of alluvial river valleys, mainly due to the difficulties in determining the shape of the channel cross-section. The article proposes a method for reconstructing extreme Holocene paleo-flow in the case of large alluvial rivers in the European Plain. It is based on identifying specific features of the geological structure of the valley, as well as elements of its bottom morphology, which can act as high water marks (HWM). The research was carried out in the section of the Bug valley, a large lowland river flowing through Ukraine, Belarus, and Poland.In the valley reach under analysis, the cross-section of the high water channel is determined by: the surface of the resistant to erosion sub-alluvial bedrock protrusion built of glacial till, and traces of flood erosion on the Pleistocene terraces, including traces of dune washouts. The age of the paleo-flow was determined by means of the C14 dating of sediments filling the flood erosion troughs. Due to the limited number of tests, the reconstructed maximum flow values are subject to uncertainty. Yet, even quite uncertain the reconstructed paleofloods may result in a significant improvement in the estimates of high quantiles using the flood frequency analysis, or at least allow to prepare for the floods not recorded by the monitoring system. In consequence, increasing the number of measurement points, and thus improving the correctness of the determination of paleo channels cross-sections, may contribute to a significant reduction in the uncertainty of the obtained paleo-flow values.

Multi-objective optimization of pressure regulators in buildings’ HVAC systems

The control accuracy of the adjustable dynamic flow balance valve regulators is closely related to the energy consumption of the buildings' HVAC system. Therefore, optimizing the control accuracy of the pressure regulator plays an important role in reducing the energy consumption of the HVAC system and indoor cooling and heating comfort. In the study, the transient dynamics calculation method was used to simulate the movement process of the regulator diaphragm. The rebound force and fatigue life of the diaphragm are the optimization goals. An improved whale algorithm is proposed to optimize the Kriging model. The sensitivity analysis of the objective function surrogate model was carried out by the single factor analysis method. Based on the improved seagull algorithm, the multi-objective optimization of the diaphragm was carried out, and the corresponding MATLAB program was compiled. The optimized Kriging proxy model has higher fitting accuracy and smaller prediction error. The rebound force of the optimized diaphragm is reduced by 13.13% compared with that before optimization, and the fatigue life is increased by 87.89%. The dynamic characteristics and control accuracy of the adjustable dynamic flow balance valve after optimizing the diaphragm are verified by experiments. The maximum flow value is reduced by 2.03%, the transition time is reduced by 15.1%, and the stable flow value is closer to 20 t/h. This study contributes to the development of machine learning models with higher fitting accuracy and provides a new feasible design method for reducing energy consumption in buildings’ HVAC systems.