Circular Area Research Articles

Flow Control in Serpentine Inlet Duct Using Vortex Generator Jets

The objective of the present research is to study the effectiveness of steady and pulsed vortex generator jets in reducing inlet flow distortion and in improving pressure recovery by effective secondary flow control in uniform inflow serpentine duct diffuser. The measurements were carried out at a test Reynolds number of 6.5 x 105 based on the diffuser inlet width. Serpentine duct diffuser consisted of two main portions, namely, a square to circular constant area transition duct followed by a circular diffusing duct. Investigations show that the flow in the serpentine diffusing duct suffers from stall on the inner wall and consequently the outflow at AIP has considerable flow distortion due to the combined effect of secondary flow and the inner wall stall. It is observed that the use of vortex generator jets, both in steady and pulsed modes, improve the performance substantially. The number of jets, location of jets, velocity ratios and the pulse frequency are some of the variables that are studied. The results obtained so far suggest that use of pulsed jet not only gives better performance but also reduces the amount of air that is needed to be injected through the jets in comparison to steady jets for similar velocity ratios.

Analysis of photospheric magnetic fields in AR 12546: a case study

We investigate high-resolution observations with the spectropolarimeter (SP) aboard the Hinode satellite of the Solar Optical Telescope (SOT) of a positive polarity sunspot of an active region (AR) (NOAA 12546). We present a case study for the properties of the thermal, magnetic field, and plasma flows as a function of the optical depth from the inversion of the observed Stokes profiles, covering a wide field of view area. Particular attention is paid to the examination of the net circular polarization (NCP) and area asymmetry of spectral lines in sunspots. We detect a large red-shifted velocity of 10 km sec−1 localized with the presence of a strong magnetic field corresponding to the NCP best fit of the inverted profiles. In addition, the comparison between the observed and calculated NCPs or Stokes V area asymmetries of spectral lines fitted well for most pixels in the field of view region, with a significant indication of a single-component inversion. We study the vertical gradients of temperature, magnetic strength, inclination field, and LOS velocity in the deeper and higher layers of the photosphere. The difference in the penumbral temperature between the two atmospheric layers is −130 K. The penumbral regions reveal a magnetic field gradient of Delta B sim -0.5 to −0.9 G km−1. The inclination gradient in the limb-side penumbra is between (Delta gamma /Delta z) = -9 times 10^{-3} deg km−1 to -3.5 times 10^{-2} deg km−1. In particular, we find a higher positive inclination gradient in the disk center-side penumbra (Delta gamma /Delta z)= 0.2 - 1.5 deg text{ km}^{-1}. The velocity gradient is (Delta V_{LOS}/Delta log tau )= -0.13 to −0.30 km sec−1 in the limb-side penumbra, and the disk center-side penumbra is given by (Delta V_{LOS}/Delta log tau )= 0.11 to 0.29 km sec−1.

A novel interval valued circular intuitionistic fuzzy AHP methodology: Application in digital transformation project selection

Since its first introduction, ordinary fuzzy sets have been extended to new types of fuzzy sets as a tool of artificial intelligence techniques. One of the recently introduced fuzzy sets, “Circular Intuitionistic Fuzzy (CIF)” sets enable us to take into account instability of the membership and non-membership degrees with a circular area & its radius. In this study, we first introduce Interval Valued CIF (IVCIF) sets and their arithmetic operations to better incorporate the uncertainty and cover a broader domain. Then, we introduce a novel IVCIF Analytic Hierarchy Process (AHP) method and apply it to evaluate Digital Transformation (DT) projects with complex nature. DT projects requiring fundamental changes in processes, business models and cultures of the companies, contribute a significant value to the companies and increase their market shares; so that they can achieve long term success and competitive advantage. On the other hand, DT problems which are usually ill-defined and include incomplete information based on human judgments, necessitate fuzzy representation. For the success of a digital transformation and to contribute excellence in engineering applications, DT projects should be carefully analyzed. For these reasons, we focus on DT project evaluation problem in application. Also, sensitivity & comparative analyses are performed.

Association of hypothyroidism during pregnancy with preconception and early pregnancy exposure to ambient particulate matter

BackgroundLimited research has been conducted on the association between preconception exposure to ambient particulate matter (PM) and hypothyroidism. This study aimed to investigate the relationship between preconception PM exposure and hypothyroidism.MethodsA retrospective case–control study at China-Japan Friendship Hospital was performed. Fine particulate matter (PM2.5) and inhalable particulate matter (PM10) were obtained from the China High Air Pollution Dataset. Buffer analysis methods were used to calculate the exposure of pregnant women to PM in a circular area of 250, 500, and 750 m in diameter at preconception and in early pregnancy. Logistic regression models were used to assess the relationship between PM and hypothyroidism. Odd ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the effect of PM on the risk of hypothyroidism.ResultsA total of 3,180 participants were studied, and they comprised 795 hypothyroid patients and 2,385 matched controls. The mean age was 31.01 years (standard deviation: 3.66) in the control group and 31.16 years (standard deviation: 3.71) in the case group. Logistic regression analysis showed that exposure to PM2.5 and PM10 in the 60-day period before the last menstrual period month (LMPM), 30-day period before the LMPM, and LMP, across all distance buffers, was associated with an increased risk of hypothyroidism (all P < 0.05). The most pronounced effect was observed during the LMPM, with PM2.5 (OR: 1.137, 95% CI: 1.096–1.180) and PM10 (OR: 1.098, 95% CI: 1.067–1.130) in the 250-m buffer. Subgroup analysis in the Changping District yielded consistent results with the main analysis.ConclusionOur study shows that preconception PM2.5 and PM10 exposure increases the risk of hypothyroidism during pregnancy.

Multimodal imaging features of acute macular retinopathy in patients with COVID-19

Objective: To investigate the multimodal imaging characteristics of acute macular retinopathy (AMR) and/or parafoveal acute middle maculopathy (PAMM) in patients with coronavirus disease 2019 (COVID-19). Methods: It was a cross-sectional study. Eight patients (15 eyes) diagnosed with AMN and/or PAMM, who presented for their initial visit at Kaifeng Eye Hospital between December 17 and December 31, 2022 and were also confirmed positive for COVID-19, were enrolled as the observation group. The patients were classified into four types based on swept-source optical coherence tomography (SS-OCT) findings. Fifteen healthy volunteers (15 eyes) without ocular or systemic diseases were recruited as the healthy control group, and one eye was randomly selected for analysis. All participants underwent detailed ophthalmic examinations, including best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, fundus photography (FP), intraocular pressure measurement, fundus infrared imaging, OCT and OCT angiography (OCTA). The foveal avascular zone (FAZ) area of the macular center was measured. General information and multimodal imaging findings were collected and analyzed. The superficial capillary plexus vessel density (SCP-VD) and deep capillary plexus vessel density (DCP-VD) were measured in circular areas with diameters of 1.0 mm, >1.0 mm and ≤3.0 mm, and>3.0 mm and ≤6.0 mm centered on the foveal center, recorded as SCP-VD1.0, 3.0, 6.0 and DCP-VD1.0, 3.0, 6.0. Statistical analyses were performed using t-tests, Mann-Whitney U tests, and chi-square tests. Results: The observation group consisted of 6 males (11 eyes) and 2 females (4 eyes) with a mean age of (26.87±11.56) years. The healthy control group included 11 males (11 eyes) and 4 females (4 eyes) with a mean age of (28.75±12.30) years. There were no statistically significant differences in age and gender distribution between the two groups (all P>0.05). All patients in the observation group experienced high fever (≥39.0 ℃) and developed ocular symptoms during the febrile period or within 24 hours after fever resolution. Among all patients, there were 5 cases (7 eyes) of Type Ⅰ, 1 case (1 eye) of Type Ⅱ, 3 cases (4 eyes) of Type Ⅲ, and 2 cases (3 eyes) of Type Ⅳ. In Type Ⅲ and Ⅳ, 3 cases (4 eyes) exhibited weakly reflective cystic spaces in the outer plexiform or outer nuclear layers, and fundus photography revealed multiple gray or reddish-brown lesions in the macular region. One case (1 eye) showed retinal superficial hemorrhage. Cotton wool spots were observed in 2 cases (4 eyes). Fundus infrared imaging showed that Type Ⅰ manifested as weak reflectivity lesions in the parafoveal central zone, with the tip pointing towards the fovea. Type Ⅱ showed no apparent abnormalities in the macular region, while Type Ⅲ and Ⅳ displayed map-like weak reflective lesions spanning the foveal center. OCTA findings demonstrated that SCP-VD1.0 in the observation group was 6.93% (4.77%, 6.93%), significantly lower than the healthy control group's 10.66% (8.05%, 10.55%) (U=174.00, P=0.016). SCP-VD3.0 in the observation group was 37.14% (32.15%, 43.48%), also lower than the healthy control group's 43.06% (38.95%, 46.55%) (U=174.00, P=0.016). DCP-VD3.0 in the observation group was 48.20% (46.11%, 50.33%), lower than the healthy control group's 51.10% (50.04%, 53.02%) (U=188.00, P=0.009). DCP-VD6.0 in the observation group was 49.27% (47.26%, 51.67%), lower than the healthy control group's 52.43% (50.07%, 53.82%) (U=70.00, P=0.004). There were no significant differences in SCP-VD6.0 and DCP-VD1.0 between the two groups (both P>0.05). Conclusions: Acute macular retinopathy in patients with COVID-19 can involve all retinal layers and present as segmental hyper-reflectivity on SS-OCT. Fundus infrared imaging reveals weak reflectivity in the affected area, fundus photography shows multiple gray or reddish-brown lesions in the macular region, and OCTA demonstrates a decrease in SCP-VD and DCP-VD.

Estimating hydrogeological parameters at groundwater level observation wells without pumping well information

Aquifer pumping is a common method of meeting human water needs, but it can also disrupt the natural flow of groundwater and cause fluctuations in groundwater levels. These fluctuations, however, can provide useful insights into hydrogeological properties when measured in an observation well. Traditional modeling methods are not well suited for analyzing such data because they lack essential details about the pumping wells, such as their number, distance from the observation well, and pumping rates. To address this issue, new impulse response function for transfer function modeling is developed that accurately describes the confined flow in such situations. The proposed function is based on the Theis solution, which uniformly distributes the effects of multiple pumping wells within a circular area around the observation well. This allows our function to accurately estimate hydrogeological parameters and pumping rates without knowing the number and specific location of pumping wells. The effects of well distance, spatial arrangement, and aquifer anisotropy on the accuracy of our function are also analyzed using synthetic experiments and Morris sensitivity analysis. The results show that the proposed function is effective in estimating essential hydrogeological parameters, such as the aquifer storativity, using only drawdown time series data from a observation well.

The Way to Quench: Galaxy Evolution in A2142

We show how the star formation activity of galaxies is progressively inhibited from the outer region to the center of the massive cluster A2142. From an extended spectroscopic redshift survey of 2239 galaxies covering a circular area of radius ∼11 Mpc from the cluster center, we extract a sample of 333 galaxies with known stellar mass, star formation rate, and spectral index D n 4000. We use the Blooming Tree algorithm to identify the substructures of the cluster and separate the galaxy sample into substructure galaxies, halo galaxies, and outskirt galaxies. The substructure and halo galaxies are cluster members, whereas the outskirt galaxies are only weakly gravitationally bound to the cluster. For the cluster members, the star formation rate per stellar mass decreases with decreasing distance R from the cluster center. Similarly, the spectral index D n 4000 increases with R, indicating an increasing average age of the stellar population in galaxies closer to the cluster center. In addition, star formation in substructure galaxies is generally more active than in halo galaxies and less active than in outskirt galaxies, proving that substructures tend to slow down the transition between field galaxies and cluster galaxies. We finally show that most actively star-forming galaxies are within the cluster infall region, whereas most galaxies in the central region are quiescent.

Cache-Enabled UAV Emergency Communication Networks: Performance Analysis With Stochastic Geometry

The unmanned aerial vehicles (UAVs) are able to assist damaged cellular networks as aerial base stations (ABSs) due to their flexibility and affordability. This paper investigates the cache-enabled UAV emergency communication networks in the post-disaster area using stochastic geometry approaches. We propose a cache-enabled UAV emergency communication network framework in which a limited number of ABSs are deployed overlaid the partially destructed cellular network. The ABSs are equipped with cache units that adopt probabilistic caching strategy. We design a content-centric association strategy within the specified circular cache area by comprehensively considering the cache status and channel conditions. Based on the framework, we derive the exact expressions of the offloading probability and average rate under the general channel model taking line-of-sight (LOS)/ non-line-of-sight (NLoS) path loss and Nakagami-m fading into account. Simulation results demonstrate that there exist optimal values for ABSs number, ABSs altitude, and cache serving radius to maximize the offloading probability and average rate. Moreover, increasing ABSs number and the cache serving radius in the case that ABSs are deployed at the relatively low altitude is beneficial to improve the system performance. A large number of ABSs helps to reduce the optimal cache serving radius for maximizing the system performance.

The PVD-Accelerated Soil Deposit Consolidation Based on Elliptic Cylindrical Model

One method to deal with the problem of soft soil is to accelerate consolidation by preloading and prefabricating a vertical drain (PVD). Consolidation analysis was based on a one-dimensional theory that required PVD as an equivalent circular well. Further studies on a simple approximate for consolidated soil were represented by equivalent permeability coefficients, kve. The equivalent conductivity coefficient is influenced by the soil and PVD permeability coefficients. The formulation of kve based on the influence area in cylindrical has been applied to a lot of construction projects. According to the comparative analysis of the classical consolidation theory, it is considered that the diameter of the circle is less representative. This study proposed a simple formulation of kve based on the elliptical assumption of influence area. The kvewas derived based on an equal average degree of consolidation in one dimension, which applied the elliptical coordinate for degree of consolidation in the radial direction. The formulation is based on an elliptical cross-section and a cylindrical coordinate formulation. The validation of this formula is conducted with numerical calculations using 2D FEM. The results show that the consolidation time in the elliptical discharge area is shorter than that in the circular discharge area. Doi: 10.28991/CEJ-2023-09-07-08 Full Text: PDF

Utilizing Direct Hydrocarbon Indicators on 3D-Seismic Data to Prove the Existence of Hydrocarbon Accumulation in the Subtle Stratigraphic Trap in the Mishrif Reservoir at the Dujaila Oil Field, SE of Iraq

The current study aims to utilize the Direct Hydrocarbon Indicators technique to identify the presence of hydrocarbons in the Carbonaceous Mishrif Formation (Late Cretaceous) from the 3D seismic data (post-stack) integrated with available information of two wells (Du-1 and Du-2). The 3D-seismic survey was carried out in 2010, covering 602.62 km2, at the Dujaila oil field in Maysan, SE of Iraq. Distinct seismic features for hydrocarbon presence indicators were diagnosed and identified on both sections of seismic amplitude and instantaneous phase, such as dim spots, flat spots, and phase polarity reversals. They helped in direct detecting the presence of hydrocarbon accumulation in the stratigraphic trap, in the region around well Du-1 at the upper part of Mishrif Formation, which is located at a time (TWT) extending from -1730 ms in the top Mishrif to underneath at TWT -1775 ms that corresponded with depth 2825 m to 2887.5 m, respectively. Furthermore, based on the well-defined position of a flat spot, which represents oil-water contact; it helped to determine the length of the oil column was 56.8 m in the vicinity of productive well Du-1. It is close to the actual length of the oil column measured in the well was 49 m. As a result, the circular area with a radius of about 3 km around well Du-1 is more suitable for low-risk drilling in the future.

Density and Dispersal Radius of Tamarixia radiata for Control of Diaphorina citri in Citrus Groves.

Tamarixia radiata (Waterston) is the main parasitoid wasp released in abandoned, organic, and non-commercial citrus grovesand in orange jasmine areas for biological control of Diaphorina citri Kuwayama (a vector of bacteria associated with huanglongbing), as a control tactic in a strategy termed External Management. The effectiveness of parasitism is influenced by the release density and radius of action of this parasitoid. This study determined the optimal release density and radius of action of T. radiata in a commercial citrus grove. Parasitoids were released at five densities (200, 400, 800, 1,600, and 3,200 wasps/ha) at the center of circular areas with four different radii (7.5, 15, 22.5, and 30m). The parasitism rate was assessed using 'Valencia' sweet orange seedlings, each bearing 35 D. citri fourth-instar nymphs, attached to 26-year-old 'Valencia' sweet orange trees along the perimeter of each radius. For the 7.5-m radius, the highest parasitism rate (74.1%) was observed at the density of 3,200 wasps/ha. However, for the 15-m radius, the density of 3,200 wasps/ha resulted in lower parasitism (30.7%) of D. citri nymphs. No parasitism was observed for densities lower than 800 wasps/ha and release radii above 15m. The highest parasitoid dispersal radius and area were 18.04m and 114.02 m2, respectively, when 3,200 wasps were released. Therefore, 3,200 wasps/ha arranged at 56 equidistant release points (approximately 57 wasps/release point) is the recommended protocol for biological control of D. citri in citrus groves.

Ex vivo analysis of ultraviolet radiation transmission through ocular media and retina in select species

The aim of this study was to assess the transmission of the ultraviolet (UV) radiation (200–400 nm) through intact enucleated globes of different species (dogs, cats, pigs, rabbits, horses, and humans) using spectrophotometry. Globes of cats (n = 6), dogs (n = 18), pigs (n = 10), rabbits (n = 6), horses (n = 10), and humans (n = 4) were analyzed. A 5–10 mm circular area of sclera and choroid from the posterior aspect of the globe was removed under a surgical microscope, leaving the retina intact in all species except the horse. Glass coverslips were added in horses and rabbits due to retinal and globe fragility. The %T of wavelengths from 200 to 800 nm were measured through the ocular media (cornea, aqueous humor, lens, and vitreous humor) and retina, and compared between species. The globes of cats and dogs allowed the most amount of UV radiation transmission, while those of pigs and humans allowed the least amount of UV radiation transmission. A small amount of UV radiation transmission through the ocular media was detected in the rabbit and horse. Results from this study will support further vision research that may be used to train companion, working, and service animals.

Детрит в высокополнотных сосновых насаждениях подтаежно-лесостепного района Средней Сибири

At the present time, certain harmful effects are observed that affect forest ecosystems. They are forest fires, phytopathogenic activities, and invasive influence, in addition to changes in climatic conditions, in particular an increase in temperature. The study is intended to determine the potential stock of wood and carbon compounds in detritus. The principal categories for it are snags, downed dead wood, and stumps. Additionally, it predicts the amount of wood residues in the conditions of the taiga forest-steppe subzone of Central Siberia. A coarse woody detritus was examined in the structurally pure forests of Scots pine (Pinus sylvestris L.). A circular area of constant radius was used as an accounting unit. The cause woody detritus in snag was 82 %, in downed dead wood was 16 % (1.5–18.3 m3‧ha–1), in stumps was 2 % (0–2.6 m3‧ha–1). The content of detritus was found in only 11 % of the total stock of the stand. The environmental quality at the location of growth had a strong effect on the amount of detritus because of the growth rate of the trees, which is higher in the ideal conditions. Most of the coarse woody detritus (66.4 %) was accumulated in the stands of productivity class I, which was almost double that in the stands of productivity class II (33.6 %). The carbon content in snags, downed dead wood, and stumps was higher in high-density stands (0.81 or more) than in medium-density stands (0.6–0.8). The age and average height of the stand were considerable indicators for predicting stocks of wood and carbon in snags. The amount of wood and carbon in the downed dead wood also depended on the growth density and total stock of wood at the location. The regression equations were generated to predict the volume of the coarse wood detritus. According to the results, it can be concluded that in the investigated stands the destructive processes were identified, which were determined by the concentration of detritus. The production of detritus was activated by both age composition, when a major part of the trees enters the mature or overmature stages, and biogenic factors, which were stimulated by pathogenesis and climatic changes. For citation: Vais A.A., Varaksin G.S., Mamedova S.K., Anuev E.A., Gerasimova O.A. Detritus Inside High Density Pine Stands in the Taiga Forest-Steppe Subzone of Central Siberia. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 9–20. (In Russ.). https:// doi.org/10.37482/0536-1036-2023-3-9-20

Mechanistic Code for Asphalt Pavements Loaded by Farming Vehicles

Farming vehicles are relatively heavy and slow-moving machines, typically equipped with rubber tracks or flotation tires (or both). The objective of this study was to develop, validate, and openly share a new mechanistic code for calculating asphalt pavement responses under the loading conditions of such vehicles. For a given farming vehicle, the loading geometry was modeled by exploiting symmetry considerations and representing tread contact areas as groups of rotated rectangular patches. For the purpose of calculating responses, the pavement system was modeled as a layered elastic half-space, loaded vertically by many small identical circular areas—collectively approximating the patches. Computational efficiency was sought by solving the layered model for one circular area and executing a series of coordinate transformations, interpolations, and translations, to represent the entire vehicle loading. The new code is named LynFarm; it was validated through its ability to reproduce mechanical responses generated by farming vehicles as they were driven over an instrumented asphalt pavement section. LynFarm is openly shared on GitHub for further verification, validation, and improvement by the pavement engineering community.

Research on the deployment of communication networks in circular areas under field conditions

This paper provides a solution for the deployment of communication nodes for network coverage in a circular area in a field environment. First, considering the overlapping of communication node coverage areas, two deployment methods are proposed, namely the regular hexagonal and the ring deployment methods, based on deployment from the center of the circle outwards and from the circumference of the circle inwards. Then, the number of nodes required for the regular hexagonal deployment method is derived and proved, and the calculation of the minimum number of communication nodes required for the ring deployment method is given. Finally, the optimal selection interval for the communication radius of the nodes is obtained through simulation, and the selection criteria for the two deployment methods are given based on the ratio of the point communication radius to the radius of the operational area.

Assessment of a Novel Semi-Automated Algorithm for the Quantification of the Parafoveal Capillary Network.

We present a novel semi-automated computerized method for the detection and quantification of parafoveal capillary network (PCN) in fluorescein angiography (FA) images. An algorithm detecting the superficial parafoveal capillary bed in high-resolution grayscale FA images and creating a one-pixel-wide PCN skeleton was developed using MatLab software. In addition to PCN detection, capillary density and branch point density in two circular areas centered on the center of the foveal avascular zone of 500μm and 750μm radius was calculated by the algorithm. Three consecutive FA images with distinguishable PCN from 56 eyes from 56 subjects were used for analysis. Both manual and semi-automated detection of the PCN and branch points was performed and compared. Three different intensity thresholds were used for the PCN detection to optimize the method defined as mean(I)+0.05*SD(I), mean(I) and mean(I)-0.05*SD(I), where I is the grayscale intensity of each image and SD the standard deviation. Limits of agreement (LoA), intraclass correlation coefficient (ICC) and Pearson's correlation coefficient (r) were calculated. Using mean(I)-0.05*SD(I) as threshold the average difference in PCN density between semi-automated and manual method was 0.197 (0.316) deg-1 at 500μm radius and 0.409 (0.562) deg-1 at 750μm radius. The LoA were -0.421 to 0.817 and -0.693 to 1.510 deg-1, respectively. The average difference of branch point density between semi-automated and manual method was zero for both areas; LoA were -0.001 to 0.002 and -0.001 to 0.001 branch points/degrees2, respectively. The other two intensity thresholds provided wider LoA for both metrics. The semi-automated algorithm showed great repeatability (ICC>0.91 in the 500μm radius and ICC>0.84 in the 750μm radius) for both metrics. This semi-automated algorithm seems to provide readings in agreement with those of manual capillary tracing in FA. Larger prospective studies are needed to confirm the utility of the algorithm in clinical practice.

CUSTOMIZED CORNEAL CROSSLINKING WITH EXCIMER LASER ASSISTED EPITHELIUM REMOVAL FOR PROGRESSIVE KERATOCONUS - ONE YEAR RESULTS.

To evaluate the one year visual and tomographic results of customized cross-linking using excimer laser assisted epithelium removal and topography-guided irradiation in the treatment of progressive keratoconus. Coimbra Ophthalmology Unit. Private practice. Coimbra, Portugal. Prospective non-randomized clinical trial. Eyes with documented progressive keratoconus were enrolled. Following de-epithelization with PTK, customized UV irradiation was performed, designed as 3 concentric circular areas centered on the thinnest point (Mosaic System, Avedro, USA). Energy exposure was 5.4J/cm2 in the outer circle and then increased centripetally to 7.2 J/cm2 and 10 J/cm2 . Corrected distance visual acuity (CDVA), refractive outcomes, and Scheimpflug tomographies (Allegro Oculyzer (WaveLight, Germany) were assessed at baseline, and 6 and 12 months postoperatively. This prospective study enrolled 37 eyes of 32 patients. Mean diameter for treated areas was 6.17 ± 0.80, 4.45 ± 0.47, and 2.58 ± 0.14 mm for the outer, medium, and inner circle, respectively. At the 1 year follow-up, mean CDVA improved significantly from 0.38 ± 0.19 to 0.20 ± 0.16 logMAR (p<0.01), with 34 of the 37 eyes (91.89%) retaining or improving CDVA. Mean pre-operative minimum pachimetry decreased from 449.26 ± 41.62 μm to 443.26 ± 41.06 μm (p=0.02). The maximal curvature (Kmax) decreased significantly from 58.50 ± 7.84 D to 57.05 ± 7.27 D (p<0.01). After 1 year, 34 eyes (91.89%) showed no signs of progression. One year after surgery, patients showed a significant improvement in visual acuity while achieving stabilization of disease progression.

Development and Research of a Medium Vertical Dipole Electromagnetic Pulse Simulator

In this paper, the design of a self-developed EMP simulator with a 5 m height and an inverted conducting mono-cone antenna with a cone half-angle of 32° is introduced. The experimental region of the simulator is a circular area of 25 m in diameter around the cone vertex. Two feeding modes, feed-in over the ground and feed-in under the ground, are realized by two different high-voltage pulse sources. It can be concluded through radiation field testing that the radiation field waveform generated by the simulator has a rise time of 2–3 ns and a half-width of about 25 ns, meeting the specifications of the EMP experimental waveform in the IEC61000-2-9 standard. Meanwhile, the differences between the engineering implementation of the simulator and its ideal structure during the design process can lead to some distortion issues in the antenna radiation characteristics and the electromagnetic radiation field it generates. The radiation field waveform and the distribution of the EMP field generated by the simulator under different feeding methods, antenna wire quantities, antenna end processing methods, and different antenna resistive loading were studied, and the changes in the radiation field waveform and field distribution with different angles and distances of the monitoring point were analyzed. Based on the measurement results, the radiation characteristics of the antenna and the factors that affect the waveform of the field were studied and analyzed. Through the aforementioned work, a comprehensive understanding of the performance, radiation characteristics, and engineering factors affecting the electromagnetic environment generated by the simulator has been obtained. On this basis, the parameters of the antenna wire quantity, antenna end processing method, and test point position of the designed simulator were reconfirmed and optimized. In summary, this work has important reference significance for mastering the development technology of such simulators, understanding their antenna radiation characteristics, and conducting EMP-related assessments and effect experiments in the future.

Machine Learning-Based Modeling of Air Temperature in the Complex Environment of Yerevan City, Armenia

Machine learning (ML) was used to assess and predict urban air temperature (Tair) considering the complexity of the terrain features in Yerevan (Armenia). The estimation was performed based on the Partial Least-Squares Regression (PLSR) model with a high number (30) of input variables. The relevant parameters include a newly purposed modification of spectral index IBI-SAVI, which turned out to strongly impact Tair prediction together with land surface temperature (LST). Cross-validation analysis on temperature predictions across a station-centered 1000 m circular area revealed quite a high correlation (R2Val = 0.77, RMSEVal = 1.58) between the predicted and measured Tair from the test set. It was concluded the remote sensing is an effective tool to estimate Tair distribution where a dense network of weather stations is not available. However, further developments will include incorporation of additional weather parameters from the weather stations, such as precipitation and wind speed, as well as the use of non-parametric ML techniques.

Conflict resolution in the case of convective weather cell circumvention

This research analyzes the area required for the conflict resolution between aircraft in two flows impacted by a convective weather cell (CWC). The CWC is introduced as a constrained area, forbidden to flight through, which affects the air traffic flows. Prior the conflict resolution, two flows and their intersection are relocated away from the CWC area (thus enabling circumvention of the CWC), which is followed by a tuning of the relocated flows intersection angle in order to create the minimal size of the conflict zone (CZ—a circular area centered at the intersection of two flows, which provides aircraft enough space to completely resolve the conflict within). Therefore, the essence of the proposed solution is in providing conflict free trajectories for the aircraft in intersecting flows that are affected by the CWC, with the goal of minimizing the CZ size, so the finite occupied airspace for the conflict resolution and the CWC circumvention could be reduced. Compared to the best solutions and current industry practice, this article is focused in reduction of the airspace required for aircraft to aircraft and aircraft to weather conflict resolution, and not to distance travelled, time savings, and fuel consumption minimization. The conducted analysis in the MicrosoftExcel2010 confirmed the relevance of the proposed model and demonstrated variations in efficiency of the utilized airspace. The proposed model's transdisciplinary nature makes it potentially applicable in other fields of study, such as the conflict resolution between unmanned aerial vehicles (UAVs) and fixed objects like buildings. Building on this model and taking in consideration large and complex data sets, such as weather related data and flight data (aircraft position, speed, and altitude), we believe it is possible to conduct more sophisticated analyses that would take advantage of Big Data.