Location Of Point Research Articles

Atrial pace mapping using intracardiac pattern matching: feasibility and accuracy

Abstract Introduction Pace mapping of atrial arrhythmia is a method to localize the origin of usually focal arrhythmias that are unstable or not persisting during EP-study and, therefore not eligible for LAT-Mapping. The technique applies pattern matching of p-waves from surface-electrocardiogram (sEKG) as well as intracardiac signals during atrial tachycardia and pacing from the site of suspected origin. The CARTO® 3 system Version 7.2 applies an automated algorithm for intracardiac pace mapping (ICPM) using the unipolar signal of the reference electrode, usually located in the coronary sinus. Methods We examined 12 consecutive patients undergoing RF pulmonary vein isolation (PVI). We performed local pacing at the anterior and posterior wall of the left atrium (LA) and the posterior and lateral wall of the right atrium (RA). The first pacing point was defined as the reference pacing site (RPS). The ICPM algorithm was applied to calculate the similarity of the IC pattern of the RPS to the IC pattern across various distances. The maps, including mesh, point locations and IC pattern similarity of each point, were exported for further analysis in the Python environment. The areas were calculated for the 5% similarity strata. Results The study assessed areas with a 95% or higher pattern similarity in different atrial regions, revealing notable differences in pattern similarity. The median area of pattern similarity was 1.48 cm² (IQR: 0.76 - 2.01 cm²) in the LA posterior, 0.62 cm² (IQR: 0.15 - 1.06 cm²) in the LA anterior, 0.60 cm² (IQR: 0.38 - 1.19 cm²) in the RA posterior, and 5.68 cm² (IQR: 2.89 - 11.1 cm²) in the RA lateral wall. Significant differences were found between the posterior and anterior walls of the LA and the RA lateral wall, as well as between the RA posterior and RA lateral wall, indicating variability in intracardiac pattern matching accuracy. Patterns below 2 cm² are acceptable for catheter ablation. An outlier was noted in the RA posterior region. Conclusion The intracardiac pattern matching for atrial arrhythmias employing the CARTO-ICPM algorithm is feasible with acceptable accuracy except for the lateral regions of the right atrium. This might be explained by the larger distance to the referent catheter in the coronary sinus and the preferred conduction direction in the crista terminalis. Enhancing localization accuracy may necessitate the adjunctive use of surface ECG-pace mapping or the deployment of an additional multipolar intracardiac reference catheter in the lateral RA.A: IC Pattern, B: Box plots similarity

Impact of Hurricane Irma on coral reef sediment redistribution at Looe Key Reef, Florida, USA

Abstract. Understanding event-driven sediment transport in coral reef environments is essential to assessing impacts on reef species, habitats, restoration, and mitigation, yet a global knowledge gap remains due to limited quantitative studies. Hurricane Irma made landfall in the Lower Florida Keys with sustained 209 km h−1 winds and waves greater than 8 m on 10 September 2017, directly impacting the Florida Reef Tract (FRT) and providing an opportunity to perform a unique comprehensive, quantitative assessment of its impact on coral reef structure and sediment redistribution. We used lidar and multibeam derived digital elevation models (DEMs) collected before and after the passing of Hurricane Irma over a 15.98 km2 area along the lower FRT including Looe Key Reef to quantify changes in seafloor elevation, volume, and structure due to storm impacts. Elevation change was calculated at over 4 million point locations across 10 habitat types within this study area for two time periods using data collected (1) approximately 1 year before the passing of Irma and 3 to 6 months following the storm's impact as well as (2) 3 to 6 months after and up to 16.5 months after the storm. Elevation change data were then used to generate triangulated irregular network (TIN) models in ArcMap to calculate changes in seafloor volume during each time period. Our results indicate that Hurricane Irma was primarily a depositional event that increased mean seafloor elevation and volume at this study site by 0.34 m and up to 5.4 Mm3, respectively. Sediment was transported primarily west-southwest (WSW) and downslope, modifying geomorphic seafloor features including the migration of sand waves and rubble fields, formation of scour marks in shallow seagrass habitats, and burial of seagrass and coral-dominated habitats. Approximately 16.5 months after Hurricane Irma (during a 13-month period between 2017 and 2019), net erosion was observed across all habitats with mean elevation change of −0.15 m and net volume change up to −2.46 Mm3. Rates of elevation change during this post-storm period were 1 to 2 orders of magnitude greater than decadal and multi-decadal rates of change in the same location, and changes showed erosion of approximately 50 % of sediment deposited during the storm event as seafloor sediment distribution began to re-equilibrate to non-storm sea-state conditions. Our results suggest that higher-resolution elevation change data collected over seasonal and annual time periods could enhance characterization and understanding of short-term and long-term rates and processes of seafloor change.

Lock Protocol : a new robust workflow for a very high first pass pulmonary vein isolation during atrial fibrillation ablation

Abstract Introduction Pulmonary vein isolation (PVI) is the gold standard for atrial fibrillation (AF) ablation. First pass PVI is often demanding when a raw geometry reconstruction is used in combination with an inaccurate automarks annotation, accounting for discontinuous or non-transmural lesions and related AF recurrences. We hypothesized that a magnetic-post processing of left atrial geometry in combination with an LSI-guided high power short duration (HPSD) automarks annotation could improve procedural efficiency. Purpose The aim of this study was to determine the impact on procedural outcomes of the new "Lock PVI protocol" during AF ablation with the new voxel mode EnSite X mapping system. Methods We included in the study consecutive patients with AF scheduled for pulmonary vein isolation (PVI) at our Departement between January 2021 and December 2022. Patients were divided in two Groups, the Lock-PVI Group and the control No Lock-PVI Group. The "Lock PVI" Group was ablated with the new Ensite X System using the new protocol, which consisted in (1) performing a road map with contact-force annotation at potential PVI sites after High Density reconstruction, (2) shaving the magnetic geometry reconstruction to unearth true 3D location of contact points, (3) Use of 3D-Automarks color-coded with a Lesion Index (LSI) target of 5.5 (anterior) and 4.5 (posterior) (4) Inter-lesion distance <6 mm (5) High Power Short Duration Approach (50 W). The No-Lock PVI was represented by patients ablated with and HPSD ablation with the previous version of the EnSite Precision mapping suit as per local standard practice. Groups were compared in term of procedural duration, radiological exposure and "first pass" isolation. Results Forty-four patients (22 "Lock PVI" and 22 controls mean age 63,3±8 years, 65,9% male, 47,7% persistent AF), for a total of 88 PVI circles were enrolled. Procedural duration was similar between approaches (121,1±43,6 vs 125,3±30,1 min; P=0,72) but RF time was shorter in the "Lock PVI" group (19,6±4 vs 29,55±9,1 min; P<0,001), although with with a longer fluoroscopy (19,5±10,1 vs 13,4±4,9 min; P=0,01). Of note, first pass isolation was significantly higher in the "Lock PVI" group: 40/44 (90,9%) vs 28/44 (63,6%) circles (P=0,002). Conclusion The new "Lock PVI" approach resulted in consistently better first-pass isolation (>90%) with less RF time when compared to standard of care PVI.Graphical AbstractLock PVI

Dynamics around small irregularly shaped objects modeled as a mass dipole

In this work, we investigate the dynamics of a spacecraft near two primary bodies. The massive body is considered to have a spherical shape, while the less massive one is elongated and modeled as a dipole. The dipole consists of two connected masses, one is spherical and the other is an oblate spheroid. The gravitational potential of the elongated body is determined by four independent parameters. To study the dynamics, we construct the equations of motion of a spacecraft with negligible mass under the effect of the current force model. The existence and locations of the equilibrium points are analyzed for various values of the system parameters. We found that the existence and locations of the points are affected by the system parameters. Also, we studied the linear stability of the equilibrium points. We found some stable collinear points when the oblateness parameter is negative, otherwise the points are not stable. We used the curves of zero velocity to identify the regions of allowed motion. Furthermore, we discussed the 2001 SN263 asteroid system and found some stable collinear points when the oblateness parameter is negative. In addition, the triangular points of the system are stable in a linear sense.

Evaluation of the arterial kink point during flexion of the hip: A dynamic angiographic study in iliac endofibrosis patients.

The aim of the study was to determine the flexion point's location of the ilio-femoral arterial axis and its angulation. Thirty-seven dynamic digital subtraction angiographies were analyzed and were included in the current study. Different lengths were measured, based on specific anatomical landmarks: the origin of the external iliac artery, the inguinal ligament and the bifurcation of the femoral artery. These lengths were measured in extension and during flexion of the hip in order to determine the flexion point of the artery. In extension, some physiological angulations of the external iliac artery were measured. During flexion of the hip joint, the distance from the kink point to the bifurcation of the common iliac artery was respectively 82 ± 21mm (range 48-116) on the right side and 95 ± 20mm (range 59-132) on the left side. The distance from the kink point to the inguinal ligament was respectively 38 ± 40mm (range 12-138) on the right side and 26 ± 23mm (range 8-136) on the left side. The distance from the kink point to the bifurcation of the femoral artery was respectively 45 ± 29mm (range 15-107) on the right side and 27 ± 12mm (range 10-66) on the left side. During flexion, the angulation of the flexion point of the ilio-femoral axis was 114 ± 18° (range 81-136°). The flexion point was located cranially to the inguinal ligament and below the departure of the external iliac artery.

Weakly Supervised Pose Estimation of Surgical Instrument from a Single Endoscopic Image.

Instrument pose estimation is a key demand in computer-aided surgery, and its main challenges lie in two aspects: Firstly, the difficulty of obtaining stable corresponding image feature points due to the instruments' high refraction and complicated background, and secondly, the lack of labeled pose data. This study aims to tackle the pose estimation problem of surgical instruments in the current endoscope system using a single endoscopic image. More specifically, a weakly supervised method based on the instrument's image segmentation contour is proposed, with the effective assistance of synthesized endoscopic images. Our method consists of the following three modules: a segmentation module to automatically detect the instrument in the input image, followed by a point inference module to predict the image locations of the implicit feature points of the instrument, and a point back-propagatable Perspective-n-Point module to estimate the pose from the tentative 2D-3D corresponding points. To alleviate the over-reliance on point correspondence accuracy, the local errors of feature point matching and the global inconsistency of the corresponding contours are simultaneously minimized. Our proposed method is validated with both real and synthetic images in comparison with the current state-of-the-art methods.

The association between childhood blood lead levels and proximity to airports in Colorado

BackgroundIn October 2023, the U.S. Environmental Protection Agency announced a final endangerment finding that leaded aviation gasoline (avgas) contributes to air pollution that is harmful to public health. This study evaluates the evidence for a link between living in proximity to airports and children’s blood lead levels in Colorado.MethodsWe analyzed the association between childhood blood lead levels (BLLs) and proximity to airport point locations in children tested for lead in Colorado over a 10-year study period (2011–2020) using a correlated random effects model with bootstrapped standard errors (N = 56,002 observations, 47,322 individuals). Along with distance from airport point locations, we identified the number of days sampled children lived downwind of their nearest airport during the 60 days prior to their test date. We also adjusted the model for age, sex, detection limit, test type, sample order, seasonality, time, proximity to lead-releasing facilities, estimated monthly aircraft traffic, and demographic characteristics of the surrounding neighborhood.ResultsOur primary model estimates that living one mile (1.6 km) further from airport point locations decreases mean blood lead levels by 0.068 µg/dL. Additional analysis estimates that living one mile further from airport point locations decreases the odds of having a blood lead level ≥ 3.5 µg/dL by 13.2%.ConclusionOur results suggest that lead emissions from aircraft using leaded avgas have a small but statistically significant effect on the BLLs of children living near airport point locations in Colorado. While the risk from proximity to airports is likely less than the risks associated with deteriorating lead paint and dust, our findings highlight the value of lead testing in children who may be at risk of exposure from all sources, including those who live near airports.

Predictions of locations of flash point and calcite scaling of geothermal fluids in wellbore by chemical and thermodynamic simulations

Geothermal energy, as a renewable energy source, has been intensively developed recently because its utilization can reduce CO2 emission, climate warming and sea level rising, and be beneficial to promote sustainable development. However, scaling in the wellbores often happens during the rising of geothermal fluids. At present, the methods to explore the scaling location principally focus on real measurement techniques and numerical simulation method. In comparison with the former, the latter is extremely time- and labor-saving to predict the scaling location based on the coupling model. In this study, the flash point and scaling locations of two geothermal wells in Hebei province are numerically simulated via ECO2N equation of state module in TOUGHREACT software, and the factors affecting the flash point and scaling locations of geothermal wells are explored. At the same time, the mechanism of geothermal fluid flash is analyzed. The prediction results show that the relative errors of scaling locations in geothermal well I and II are 5.43 % and 6.82 % compared to the field measured data; the pressure and temperature of geothermal fluids at well bottom can be calculated based on the related parameters of wellhead fluid; the locations of flash point and scaling can be determined according to the sudden increases of CO2 partial pressure and scaling amount, respectively. Furthermore, the liquid mass flow rate, CO2 mass flow rate and wellbore diameter have prominent influence on the locations of flash point and scaling, while wellbore diameter have significant effect on the amount of calcite scaling. The above conclusions provide useful guidelines for the next scaling removal and control in the production wellbore during the utilization of the geothermal energy.

Public Bicycle Dispatch Method Based on Spatiotemporal Characteristics of Borrowing and Returning Demands

Public bicycle systems (PBSs) serve as the ‘last mile’ of public transportation for urban residents, yet the problem of the difficulty in borrowing and returning bicycles during peak hours remains a major bottleneck restricting the intelligent and efficient operation of public bicycles. Previous studies have proposed reasonable models and efficient algorithms for optimizing public bicycle scheduling, but there is still a lack of consideration for actual road network distances between stations and the temporal characteristics of demand at rental points in the model construction process. Therefore, this paper aims to construct a public bicycle dispatch framework based on the spatiotemporal characteristics of borrowing and returning demands. Firstly, the spatiotemporal distribution characteristics of borrowing and returning demands for public bicycles are explored, the origin–destination (OD) correlation coefficients are defined, and the intensity of connections between rental point areas is analyzed. Secondly, based on the temporal characteristics of rental point demands, a random forest prediction model is constructed with weather factors, time characteristics, and rental point locations as feature variables, and station bicycle-borrowing and -returning demands as the target variable. Finally, bicycle dispatch regions are delineated based on actual path distances between stations and OD correlation coefficients, and a public bicycle regional dispatch optimization method is established. Taking the PBS in Ningbo City as an example, the balancing optimization framework proposed in this paper is validated. The results show that the regional dispatch optimization method proposed in this paper can achieve optimized dispatch of public bicycles during peak hours. Additionally, compared with the Taboo search algorithm (TSA), the genetic algorithm (GA) exhibits a 11.1% reduction in rebalancing time and a 40.4% reduction in trip cost.

Dual-layer optimization planning for offshore wind farms considering power system security

The vigorous development of offshore wind farms (OWFs) has further promoted the utilization of wind energy. Owing to the demand for low-carbon environmental protection, the increase in the scale of OWF constructions has also had a significant impact on the power system, which cannot be ignored. Specifically, the uncertainty and volatility of wind-power generation should be considered in power system optimization planning schemes. Therefore, this study proposes a probabilistic power-flow analysis index construction method that employs the static-security region theory to optimize the OWFs–grid-connection topology, including the number, location, and capacity of the public connection points connected to the onshore power grid. This method can be used to calculate the probability indicators of power grid insecurity for OWFs–grid-connected systems with different network topologies. Furthermore, a dual-layer multi-objective programming model that considers the economics and stability for integrated planning of electrical collector and multiterminal direct current transmission systems is established. The proposed model comprises two inner-layer models and one outer-layer model. The inner-layer models are used to construct the collection and transmission topologies of the OWFs–grid-connected system that minimize the probability of grid insecurity and the planning cost of the outer-layer model. Finally, the effectiveness of the proposed OWFs planning model was verified using an improved IEEE 24-bus system that can be used for topology planning of electrical collector and transmission systems while ensuring grid stability.

Tax policy and activation of internal factors of economic growth: EU experience for Ukraine

The state policy of Ukraine aims to promote sustainable economic growth and improve its quality through economic activity, particularly through the optimization of the tax system, which is particularly relevant both during the period of martial law in Ukraine and the post-war recovery. The purpose of the study is to assess the formation and implementation of the state tax policy to activate the internal factors of economic growth in Ukraine under martial law. The study of tax policy in Ukraine and EU countries has shown that the EU countries are characterized by a consistent and transparent tax policy that stimulates investment, innovation, and entrepreneurship to activate internal factors of economic growth. The paper uses fiscal analysis based on the Cobb-Douglas production-institutional function; its main concept is the mutual location of the Laffer points of the first and second types and the actual level of the tax burden. The results show a noticeable adjustment of the real fiscal climate in Ukraine in line with changes in threshold fiscal standards. Considering martial law in Ukraine and the need for the state’s ability to post-war recovery, the study suggests changing the rates of specific taxes, after which it is necessary to make a transition from private fiscal instruments with inherent rate values to the aggregate fiscal burden.

Detection and Location of High Impedance Fault on the Nigerian 330kV Transmission System Using Artificial Neural Network

The effect of the occurrence of high impedance fault (HIF) in power system networks results to low current signal which cannot be detected by the electrical equipment which results to fire outbreaks. Nigerian power system network has witnessed the occurrence of HIF which has led to fire outbreak in buildings and in minor cases grid collapse. In this paper, the performance of ANN in the detection and location of HIF was studied and determined. The transmission network located in south-south region of the Nigerian 330kV power system network was obtained and modeled in SIMULINK. The line distance was split into six points and implemented in the SIMULINK to obtain the current signals at each point of the lines. The current signals were used as the input data with the split distance utilized as the target to the ANN model. The ANN had three input neurons (each neuron represented the phase current signal), the hidden layer had five neurons with each neuron incorporating log sigmoid curve and the output layer having one neuron which was the split distance. The outcome had the least error deviation value of 0.0118 making the performance of ANN effective in the point location of HIF occurrence on the transmission line.

Revisiting reachability-driven explicit MPC for embedded control

The real-time implementation of the explicit MPC suffers from the evaluation of the, potentially large, lookup table. The paper revisits the original approach and presents an efficient reachability-sets-driven-based explicit MPC method addressing this issue by splitting the look-up table into the set of the “relevant” subsets. Simultaneously, effective binary encoding is introduced to minimize the runtimes and the memory footprint. Further acceleration is achieved by introducing the “smart” order of the considered critical regions. Then, the significant real-time complexity reduction is ensured by online pruning and traversing the sorted lookup table associated with the optimal control law evaluation. Technically, the number of critical regions to be explored is reduced and the order is redefined to accelerate the point location problem and minimize the computational effort. While the optimality of the control law is still preserved, the cost that we need to pay for the accelerated point location problem lies in an additional offline computation effort and a minor increase in memory requirements of the underlying controller. The benefits of the proposed method are demonstrated using an extensive case study. The complexity reduction strategy was investigated on two fast-dynamic benchmark systems and the computational burden was analyzed by implementing the designed controllers on an embedded hardware.

LOCK PROTOCOL: A NEW ROBUST WORKFLOW FOR A VERY HIGH FIRST PASS PULMONARY VEIN ISOLATION DURING ATRIAL FIBRILLATION ABLATION

Abstract Introduction Pulmonary vein isolation (PVI) is the gold standard for atrial fibrillation (AF) ablation. First pass PVI is often demanding when a raw geometry reconstruction is used in combination with an inaccurate automarks annotation, accounting for discontinuous or non–transmural lesions and related AF recurrences. We hypothesized that a magnetic–post processing of left atrial geometry in combination with an LSI–guided high power short duration (HPSD) automarks annotation could improve procedural efficiency. Purpose Aim of the study was to determine the impact on procedural outcomes of the new “Lock PVI protocol” during AF ablation with the new voxel mode EnSite X mapping system. Methods We included in the study consecutive patients with AF scheduled for pulmonary vein isolation (PVI) at our Departement between January 2021 and December 2022. Patients were divided in two Groups, the Lock–PVI Group and the control No Lock–PVI Group. The “Lock PVI” Group was ablated with the new Ensite X System using the new protocol, which consisted in (1) performing a road map with contact–force annotation at potential PVI sites after High Density reconstruction, (2) shaving the magnetic geometry reconstruction to unearth true 3D location of contact points, (3) Use of 3D–Automarks color–coded with a Lesion Index (LSI) target of 5.5 (anterior) and 4.5 (posterior) (4) Inter–lesion distance £6 mm (5) High Power Short Duration Approach (50 W). The No–Lock PVI was represented by patients ablated with and HPSD ablation with the previous version of the EnSite Precision mapping suit as per local standard practice. Groups were compared in term of procedural duration, radiological exposure and “first pass” isolation. Results Forty–four patients (22 “Lock PVI” and 22 controls mean age 63,3±8 years, 65,9% male, 47,7% persistent AF), for a total of 88 PVI circles were enrolled. Procedural duration was similar between approaches (121,1±43,6 vs 125,3±30,1 min; P=0,72) but RF time was shorter in the “Lock PVI” group (19,6±4 vs 29,55±9,1 min; P<0,001), even if with a longer fluoroscopy (19,5±10,1 vs 13,4±4,9 min; P=0,01). Of note, first pass isolation was significantly higher in the “Lock PVI” group: 40/44 (90,9%) vs 28/44 (63,6%) circles (P=0,002). Conclusion The new “Lock PVI” approach allowed a consistently better first pass isolation (>90%) with less RF time when compared to standard of care PVI.

Evaluation of the horizontal approach to the medial malleolar facet in sagittal talar fractures through dorsiflexion and plantarflexion positions.

Talar fractures often require osteotomy during surgery to achieve reduction and screw fixation of the fractured fragments due to limited visualization and operating space of the talar articular surface. The objective of this study was to evaluate the horizontal approach to the medial malleolus facet by maximizing exposure through dorsiflexion and plantarflexion positions. In dorsiflexion, plantarflexion, and functional foot positions, we respectively obtained the anterior and posterior edge lines of the projection of the medial malleolus on the medial malleolar facet. The talar model from Mimics was imported into Geomagic software for image refinement. Then Solidworks software was used to segment the medial surface of the talus and extend the edge lines from the three positions to project them onto the "semicircular" base for 2D projection. The exposed area in different positions, the percentage of total area it represents, and the anatomic location of the insertion point at the groove between the anteroposternal protrusions of the medial malleolus were calculated. The mean total area of the "semicircular" region on the medial malleolus surface of the talus was 542.10 ± 80.05 mm2. In the functional position, the exposed mean area of the medial malleolar facet around the medial malleolus both anteriorly and posteriorly was 141.22 ± 24.34 mm2, 167.58 ± 22.36mm2, respectively. In dorsiflexion, the mean area of the posterior aspect of the medial malleolar facet was 366.28 ± 48.12 mm2. In plantarflexion, the mean of the anterior aspect of the medial malleolar facet was 222.70 ± 35.32 mm2. The mean overlap area of unexposed area in both dorsiflexion and plantarflexion was 23.32 ± 5.94 mm2. The mean percentage of the increased exposure area in dorsiflexion and plantarflexion were 36.71 ± 3.25% and 15.13 ± 2.83%. The mean distance from the insertion point to the top of the talar dome was 10.69 ± 1.24 mm, to the medial malleolus facet border of the talar trochlea was 5.61 ± 0.96 mm, and to the tuberosity of the posterior tibiotalar portion of the deltoid ligament complex was 4.53 ± 0.64 mm. Within the 3D model, we measured the exposed area of the medial malleolus facet in different positions and the anatomic location of the insertion point at the medial malleolus groove. When the foot is in plantarflexion or dorsiflexion, a sufficiently large area and operating space can be exposed during surgery. The data regarding the exposed visualization area and virtual screws need to be combined with clinical experience for safer reduction and fixation of fracture fragments. Further validation of its intraoperative feasibility will require additional clinical research.

ENVIRONMENTAL ASSESSMENT OF SOIL STATE IN THE IMPACT ZONE OF THE SREDNEURALSKY COPPER SMELTER

As part of the study of the ecological state of soils and vegetation in the zone of impact of the Sredneuralsky Copper Smelter (SUMZ), the following tasks were solved: the content of heavy metals in the soils of the test sites laid within the zone of impact of the SUMZ was determined; macrokinetic patterns of seasonal dynamics of the normalized relative vegetation index (NDVI) at the test sites in the zone of impact of the SUMZ were revealed; macrokinetic patterns of vegetation response in the form of NDVI, calculated according to MODIS and Landsat 8 data, to soil pollution by a complex of heavy metals in the zone of impact of the SUMZ were revealed; soil quality was ranked according to the patterns of vegetation response in the form of NDVI to soil pollution by a complex of heavy metals within the boundaries of the natural protection zone (NZZ) of the SUMZ according to 2023. The intra-seasonal dynamics of photosynthetically active biomass in the form of NDVI was modeled using a theoretical growth equation based on MODIS satellite data. The seasonal maximum of the vegetation index at the trial sites in 2012 fell on the 25-28 week. In 2023, it occurred on the 27-33 week, depending on the location of the sampling point. The rate of maximum achievement is characterized by weak intra-seasonal and interannual variation. The patterns of changes in the concentration of photosynthetically active biomass in the form of maximum NDVI for the 2023 season in response to the gross content of a complex of heavy metals (Cu, Pb, Cd and Zn) in the soil of the test sites were modeled using the theoretical equation of dose dependence. The maximum permissible level of the heavy metal complex in the soil in the form of a geometric mean, which does not cause a decrease in the values of the vegetation index calculated according to the data of the MODIS and Landsat 8 satellites, was 101 and 106 mg·kg-1, respectively. The analysis of histograms of the distribution of NDVI values within the NZZ was carried out, which showed how the true frequencies of occurrence of the values of the vegetation index correspond to the empirical boundary of the NZZ associated with the maximum dose dependence point identified by the study of the 2012. The nature of the distribution of true NDVI values for the NZZ exclusively fully supports the used zoning theory based on the analysis of dose dependence. The modern boundaries of the SUMZ natural protection zone are 4-7 km away from the center of the sanitary protection zone.

Intelligent optimal layout of drainage pipe network monitoring points based on information entropy theory

The rapid expansion of urban drainage pipe networks, driven by economic development, poses significant challenges for efficient monitoring and management. The complexity and scale of these networks make it difficult to effectively monitor and manage the discharge of urban domestic sewage, rainwater, and industrial effluents, leading to illegal discharges, leakage, environmental pollution, and economic losses. Efficient management relies on a rational layout of drainage pipe network monitoring points. However, existing research on optimal monitoring point layout is limited, primarily relying on manual analysis and fuzzy clustering methods, which are prone to human bias and ineffective monitoring data. To address these limitations, this study proposes a coupled model approach for the automatic optimization of monitoring point placement in drainage pipe networks. The proposed model integrates the information entropy index, Bayesian reasoning, the Monte Carlo method, and the stormwater management model (SWMM) to optimize monitoring point placement objectively and measurably. The information entropy algorithm is utilized to quantify the uncertainty and complexity of the drainage pipe network, facilitating the identification of optimal monitoring point locations. Bayesian reasoning is employed to update probabilities based on observed data, while the Monte Carlo method generates probabilistic distributions for uncertain parameters. The SWMM is utilized to simulate stormwater runoff and pollutant transport within the drainage pipe network. Results indicate that (1) the relative mean error of the parameter inversion simulation results of the pollution source tracking model is linearly fitted with the information entropy. The calculation shows that there is a good positive linear correlation between them, which verifies the feasibility of the information entropy algorithm in the field of monitoring node optimization; (2) the information entropy algorithm can be well applied to the optimal layout of a single monitoring node and multiple monitoring nodes, and it can correspond well to the inversion results of the tracking model parameters; (3) the constructed monitoring point optimization model can well realize the optimal layout of monitoring points of a drainage pipe network. Finally, the pollution source tracking model is used to verify the effectiveness of the optimal layout of monitoring points, and the whole process has less human participation and a high degree of automation. The automated monitoring point optimization layout model proposed in this study has been successfully applied in practical cases, significantly improving the efficiency of urban drainage network monitoring and reducing the degree of manual participation, which has important practical significance for improving the level of urban water environment management.

Study on Temperature Cascade ELM Inversion Method for 110 kV Single-Core Cable Intermediate Joints

The accurate calculation of the hotspot temperature of the cable intermediate joint can effectively guarantee the safe operation of the transmission and distribution network. This paper addresses the limitations of the current method of estimating hotspot temperature solely from surface temperature measurements. Specifically, we focus on a 110 kV single-core cable as our subject of study. We started by establishing a simulation model for the temperature field at the intermediate joint to generate data samples. Subsequently, the NCA (neighborhood component analysis) algorithm was employed to select the optimal measurement points on the cable’s surface. This allowed determination of the quantity and location of characteristic points. Finally, we developed a cascading inversion model, which consists of a radial inversion model and an axial inversion model, based on the extreme learning machine algorithm. The example results show that the mean squared error of hotspot temperature obtained by cascade inversion and direct inversion is 6.95 and 24.71, respectively, indicating that cascade inversion can effectively improve the inversion accuracy.

Adjusting exceptional points using saturable nonlinearities

We study the impact of saturable nonlinearity on the presence and location of exceptional points in a non-Hermitian dimer system. The inclusion of the saturable nonlinearity leads to the emergence of multiple eigenvalues, exceeding the typical two found in the linear counterpart. To identify the exceptional points, we calculate the nonlinear eigenvalues both from a polynomial equation for the defined population imbalance and through a fully numerical method. Our results reveal that exceptional points can be precisely located by adjusting the non-equal saturable nonlinearities in the detuning space.

An Eulerian–Lagrangian method of fundamental solutions for the advection–diffusion equation with time dependent coefficients

This paper investigates the application of the Eulerian–Lagrangian method of fundamental solutions (ELMFS), a truly meshless method that couples the Euler–Lagrange Method (ELM) with the time-dependent method of fundamental solution (MFS). It is applied to solve the transient advection–diffusion equation with transport coefficients exhibiting constant and temporally exponential behaviors. The stability and accuracy of the proposed method were analyzed in terms of condition numbers, location of source points, and error metrics. The stability results for constant coefficients of partial differential equations are presented in a map and compared with well-established stability criteria for explicit in-time mesh methods, such as the Courant–Friedrichs–Lewy and Von Neumann criteria. These comparisons demonstrate that ELMFS has larger stable regions.