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1
Orchidea, Maria Lecian. "REDUCED 2-DIMENSIONAL BIRKHOFF SURFACES OF SECTION OF THE DESYMMETRIZED P SL(2, Z) GROUP: THE ANOSOV CHARACTERIZATION." INTERNATIONAL JOURNAL OF MATHEMATICS AND COMPUTER RESEARCH 11, no. 02 (2023): 3261–67. https://doi.org/10.5281/zenodo.7660769.
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New 2-dimensional Birkhoff surfaces of sections are defined for the desymmetrized P SL(2, Z) group. The new object is demonstrated to be apt to study the geodesics flow solution of the Hamiltonian problem. The new definitions of the return maps of the new 2-dimensional Birkhoff surface of section are provided with; The demonstration relays on the self-adjointed-ness of the operators on which the conjugacy subclasses needed in the application to reduced surds act
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Lecian, Orchidea Maria. "REDUCED 2-DIMENSIONAL BIRKHOFF SURFACES OF SECTION OF THE DESYMMETRIZED P SL(2, Z) GROUP: THE ANOSOV CHARACTERIZATION." INTERNATIONAL JOURNAL OF MATHEMATICS AND COMPUTER RESEARCH 11, no. 02 (2023): 3261–67. http://dx.doi.org/10.47191/ijmcr/v11i2.07.
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New 2-dimensional Birkhoff surfaces of sections are defined for the desymmetrized P SL(2, Z) group. The new object is demonstrated to be apt to study the geodesics flow solution of the Hamiltonian problem. The new definitions of the return maps of the new 2-dimensional Birkhoff surface of section are provided with; The demonstration relays on the self-adjointed-ness of the operators on which the conjugacy subclasses needed in the application to reduced surds act
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Guckenheimer, John. "Principal Foliations of Surfaces near Ellipsoids." New Zealand Journal of Mathematics 52 (September 19, 2021): 361–79. http://dx.doi.org/10.53733/126.
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The lines of curvature of a surface embedded in $\R^3$ comprise its principal foliations. Principal foliations of surfaces embedded in $\R^3$ resemble phase portraits of two dimensional vector fields, but there are significant differences in their geometry because principal foliations are not orientable. The Poincar\'e-Bendixson Theorem precludes flows on the two sphere $S^2$ with recurrent trajectories larger than a periodic orbit, but there are convex surfaces whose principal foliations are closely related to non-vanishing vector fields on the torus $T^2$. This paper investigates families of such surfaces that have dense lines of curvature at a Cantor set $C$ of parameters. It introduces discrete one dimensional return maps of a cross-section whose trajectories are the intersections of a line of curvature with the cross-section. The main result proved here is that the return map of a generic surface has \emph{breaks}; i.e., jump discontinuities of its derivative. Khanin and Vul discovered a qualitative difference between one parameter families of smooth diffeomorphisms of the circle and those with breaks: smooth families have positive Lebesgue measure sets of parameters with irrational rotation number and dense trajectories while families of diffeomorphisms with a single break do not. This paper discusses whether Lebesgue almost all parameters yield closed lines of curvature in families of embedded surfaces.
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Anil, Pangeni, Bhurtyal Umesh, Pokhrel Madan, Poudel Samrat, and Bahadur Katuwal Netra. "Flood Hazard Mapping and Risk Assessment in Narayani River Basin, Nepal." Flood Hazard Mapping and Risk Assessment in Narayani River Basin, Nepal 8, no. 12 (2023): 9. https://doi.org/10.5281/zenodo.10389870.
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Floods, earthquakes, forest fires, landslides, and other natural hazard are common in Nepal. Among them, the flood is one of the natural disasters and that occurred in the Narayani River basin. The Narayani River Basin's exposures and vulnerabilities are at danger from a flood catastrophe of this kind, hence this studies attempts to reduce and control the risk of flooding in order to better manage disasters. The factors of flood hazard, flood exposures, and flood vulnerability are investigated as part of the ward-level flood risk assessment, which aims to prevent and manage the flood disaster. The hydraulic model (HEC-RAS) for the 2018 flood event was used in this study to create the GIS- based modeling of the flood inundation maps. Additionally, it calculated the various return periods for floods in the river basin—5, 10, 25, 50, 75, and 100 years. Furthermore, the flood extent was confirmed using the flood map produced by the Google Earth Engine (GEE) using remotely sensed techniques. For Hydraulic modelling, ALOS/PALSAR Digital Elevation Model (12.5m.) spatial resolution was used. In addition, RAS-MAPPER generated the geometric data for the hydraulic modeling, which was then transferred into HEC-RAS. This data included the cross-section, flow route, streamline, and bank lines. On both sides of the river, the necessary Manning value "n" values were computed for every cross-section. The steady-flow models of the anticipated flood hydrographs were created using the hydraulic model. Google Earth Engine (GEE) flood maps generated from Sentinel-1C radar satellite data were used to validate the results for the 2018 flood events. When comparing the simulated result's flood inundation area with the remote sensing data's flood area, the overlap area for the 2018 flood event is 65%. Additionally, the flood area is verified. In addition, the hydraulic model generated flow conditions for 5, 10, 25, 50, 75, and 100 year return periods. The river basin's surface water level and flood extent are both progressively rising. In order to effectively manage and prepare for potential flood hazards in the study area, an analysis of the flood risk assessment was conducted by taking into consideration three primary factors: the flood hazard map, flood exposure, and flood vulnerability. The layers of the population, crops, schools, hospitals, and road network were all exposed to flooding, and the factors that determined flood vulnerabilities were literacy, urban area, and agecomposition (less than 14 and more than 65). The higher flood risk area was found in Ward number 1, 3, 4,16,18,26 of Bharatpur metropolitan, Gaindakot municipality ward number 1 and 12, 15 of Madhyabindu Municipality. Keywords:- Hydraulic model, Flood inundation, Flood risk, Flood exposure, Flood vulnerability, Flood hazard.
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Basnet, Keshav, and Deepak Acharya. "Flood Analysis at Ramghat, Pokhara, Nepal Using HEC-RAS." Technical Journal 1, no. 1 (2019): 41–53. http://dx.doi.org/10.3126/tj.v1i1.27591.
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Flooding in Ramghat area of Pokhara, Nepal is the major problem that has to be faced every year by the people residing nearby the area. Main goal of this study was to conduct the flood analysis of Seti River in Ramghat. Catchment area of the Ramghat was calculated to be 574.56 sq. km. using ArcGIS where the area above 5000 m elevation was 52 sq. km. and area below 3000 m elevation was 356 sq. km. Precipitation data of two meteorological stations, Pokhara airport and Lumle, were used in this research for the calculation of peak discharge. PCJ method (1996) was used to estimate the peak flood and also compared with the peak flood calculated using Modified Dicken's formula, WECS/DHM method, Rational method and Sharma and Adhikari (2004) method. Peak flood values were found to be 1918 m3/s and 2336 m3/s by PCJ method for return period of 50 years and 100 years respectively. The HEC-RAS modelling was performed for these flooding situations to determine the water surface profile along the eight cross-sections of the Ramghat. Finally, the floodplain map was prepared using the topographic map and the Google Earth Map. It was found that 50 years flood in Ramghat could inundate three cemetery shades situated along the river banks. Most importantly, 100 years’ peak flood was found more vulnerable for residential buildings too. The flood plain maps prepared in this study can be used by government authorities for planning, decision making, early warning system and disaster risk management. Additionally, the rating curve was prepared for the outlet section of Ramghat that can be used to estimate the river discharge during flooding in future.
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Xafoulis, Nikolaos, Yiannis Kontos, Evangelia Farsirotou, et al. "Evaluation of Various Resolution DEMs in Flood Risk Assessment and Practical Rules for Flood Mapping in Data-Scarce Geospatial Areas: A Case Study in Thessaly, Greece." Hydrology 10, no. 4 (2023): 91. http://dx.doi.org/10.3390/hydrology10040091.
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Floods are lethal and destructive natural hazards. The Mediterranean, including Greece, has recently experienced many flood events (e.g., Medicanes Zorbas and Ianos), while climate change results in more frequent and intense flood events. Accurate flood mapping in river areas is crucial for flood risk assessment, planning mitigation measures, protecting existing infrastructure, and sustainable planning. The accuracy of results is affected by all simplifying assumptions concerning the conceptual and numerical model implemented and the quality of geospatial data used (Digital Terrain Models—DTMs). The current research investigates flood modelling sensitivity against geospatial data accuracy using the following DTM resolutions in a mountainous river sub-basin of Thessaly’s Water District (Greece): (a) open 5 m and (b) 2 m data from Hellenic Cadastre (HC) and (c) 0.05 m data from an Unmanned Aerial Vehicle (UAV) topographical mission. RAS-Mapper and HEC-RAS are used for 1D (steady state) hydraulic simulation regarding a 1000-year return period. Results include flood maps and cross section-specific flow characteristics. They are analysed in a graphical flood map-based empirical fashion, whereas a statistical analysis based on the correlation matrix and a more sophisticated Machine Learning analysis based on the interpretation of nonlinear relationships between input–output variables support and particularise the conclusions in a quantifiable manner.
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Ivanov, Yu A., V. I. Byshev, Yu A. Romanov, and A. N. Sidorova. "ON THE STRUCTURE OF THE NORTH ATLANTIC CURRENT IN MAY – JUNE 1990." Journal of Oceanological Research 47, no. 2 (2019): 33–63. http://dx.doi.org/10.29006/1564-2291.jor-2019.47(2).4.
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“In the last quarter of the ХХ-th century, our country has implemented several major programs of experimental research of the World ocean. Among them, a special place was occupied by the huge in its scale and scientific significance the project SECTIONS aimed at studying the climatic interaction of the ocean and atmosphere. Currently, systematic research in this field has gained new momentum through regular Hydrophysical monitoring of the energy-active region in the North Atlantic in the annual expeditions by Shirshov Institute of Oceanology of RAS (Gladyshev et al., 2017). The results of some special Russian ocean expeditions of the past years, one of which is described for the first time in this article, can serve as a certain historical background for modern studies of the ocean climate evolution”. In 1990 Russian oceanographers carried out a comprehensive hydrophysical study of the Newfoundland energy-active zone in the Northern Atlantic ocean, as part of the national project “Sections” included in the international program WOCE. Three research vessels (R/V) of the Shirshov Institute of Oceanology (SIO): “Vityaz“(cruise 19), “Professor Stockman“( cruise 26) and “Academician Kurchatov“ (cruise 50) together with additional 4 vessels of other institutions were engaged in the field study. Scientific management for general programme of the expedition, dubbed “ATLANTEX-90”, was carried out by Professor Yu. A. Ivanov. The main objective of the program was to study the space-time short-period variability of water dynamics in the large – scale ocean circulation system of Gulfstream–North Atlantic Current. To this aim, in May–June 1990 R/V “Academician Kurchatov” performed several sections crossing the main hydrological fronts of the Newfoundland energy-active zone (45–53°N., 36–45°W). Observations were conducted using the cable probe with sensors of temperature, conductivity and pressure (CTD) and expendable bathythermograph (XBT). All this equipment was special made and passed metrological certification in the design Bureau of Oceanological Engineering (BOE) of SIO. The equipment metrology fitted in whole with international standards at that time. The sea surface temperature (SST) was recorded along the RV route as well. The current velocity was measured during about one month at 14 moorings deployed on a section along meridian 36°W, from 47 to 53°N. The measurements were conducted using electronically operated current meters of POTOK type of the BOE of SIO production. The meters were installed on the each mooring at the horizons of 100, 200, 1000, 2000, 3500 m. In addition to the data of own measurements, facsimile maps of SST from the nearest hydrometeorological observatories were received by radio communication channel during the whole period of observations. Analysis of the obtained data showed that during the field study period the North Atlantic Current (NAC) divided into two branches (Central and Southern) roughly in the neighborhood of 47.5–48°N, where isobath 4500 m turned to the East at right angle to isobath 4000 m. After point of the bifurcation, the Central branch initially maintained a Northerly direction, then turned North-West along the isobath of 4000 m, and farther, turning East, crossed the meridian of 36°W between 51° and 52°N. Prior that stage, the Central branch sometimes approached the meridian 36°W at about 50°N, then deviated to the North–Northwest and finally turned North-East about 51,5°N. The Southern branch of NAC after a split of the main NAC flow followed approximately to isobath 4500 m, and crossed the meridian of 36°W at about 48°North latitude. East of 36°W it could be at times of East-North-East direction, but usually this branch unfolded to the South-South-West, forming the high ridge of the ocean surface dynamic height on the Eastern flank of the NAC. Three return flows were observed in the section of 36°W. One of the flows is marked between the Central and Southern branches of the NAC, while the other two were recorded on the Northern and Southern edges of the section. This structure of the velocity field in fact remained unchanged through all June 1990. The basic zonal flow was observed in the entire water column within the depths from 100 m to 3500 m. The highest current speeds were typical for the upper part of this layer. At depths of 1000–2000 m the velocities were noticeably weakened, increasing again in some places near the bottom. The distribution of meridional components of flow speed according to the measurements on the buoys allowed us to detect the presence of large-scale divergence, which was located along the section on 36°W. Direction of the meridional component of the current to the North and South of 49°N turned out to be the opposite, forming that divergence in the field of the velocity. Under the analysis of the observations it was taken into account that an important role in the formation of the structure of ocean circulation in the area of research could play a seamount (>2600 m), registered by the sounders of R/V “Academician Kurchatov” near 49°N, 36°W. The results of measurements and calculations showed that the average over the entire observation period water transport of the Central branch of NAC through the 36°W section accounted for 62.4 Sv. This value is comparable to the transfer of NAC, assessed four years later by Lazer (1994) 50±23 Sv for approximately the same area where we conducted our work in 1990. Approximately the same average transfer (46,5 Sv) was found in two return flows (presumably North and South recirculations of the NAC Southern branch). In whole, the average water transport in the Eastern direction through the section on 36°W was as high as 111 Sv., and it was 60.9 Sv after subtracting reverse fluxes.
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Syahputra, Zulfan. "Perhitungan Dimensi Saluran Drainase Pada Daerah Persawahan Separi III dan IV Kabupaten Kutai Kartanegara." Kurva S : Jurnal Keilmuan dan Aplikasi Teknik Sipil 5, no. 3 (2017): 137. http://dx.doi.org/10.31293/teknikd.v4i2.2014.
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ABSTRACT The agricultural sector always get the attention and priority to each lamp carried out, an irrigated land needed careful planning of drainage on irrigated to prevent flooding or inundation on irrigated land.The development of irrigation network planning techniques require saluaran irrigation network which includes primary and secondary irrigation channels. The data used in planning is that the meteorological data of rainfall data, maps Contur, and data topogragrafi. The study provides the magnitude of channel dimensions trapezoidal return period of 2 years dngean dimensions W = 0.410 m, T = 2,203 m, b = 1,203 m, h = 0.746 m, while the return period of 5 years with channel dimensions W = 0.410 m, T = 2221 m, b = 1.213 m, h = 0.746 m, and when the channel dimensions 10years W = 0411 m, T = 2.232 m, b = 1.219 m, h = 0749 m.Drainage on the rice fields Separi III and IV functioned as the discharge channel rainwater runoff and excess water from the tertiary. surface drainage system open channel with trapezoidal cross-section. Trapezoidal channel shape selected for the stability of the slope of the walls can be adjusted with the material / material forming the body of the channel. Key-words : Dimension channels, primary and secondary irrigation canals, form a trapezoidal channel.ABSTRACTSector pertanian senantiasa mendapatkan perhatian dan prioritas pada setiap pelita yang dilaksanakan, suatu lahan sawah beririgasi diperlukan adanya perencanaan yang matang drainase pada sawah beririgasi untuk mencegah terjadinya banjir atau genangan pada lahan beririgasi.Pengembangan jaringan irigasi teknik memerlukan perencanaan jaringan saluaran irigasi yang meliputi saluran irigasi primer dan sekunder.Data yang digunakan dalam perencanaan adalah data meteorologi yaitu data curah hujan, peta contur, dan data topogragrafi. Hasil studi memberikan besaran dimensi saluran berbentuk trapesium kala ulang 2 tahun dngean dimensi W = 0.410 m, T = 2.203 m, b = 1.203 m, h = 0.746 m, sedangkan kala ulang 5 tahun dengan dimensi saluran W = 0.410 m, T = 2.221 m, b = 1.213 m, h = 0.746 m, dan dimensi saluran kala ulang 10 tahun W = 0.411 m, T = 2.232 m, b = 1.219 m, h = 0.749 m.Drainase pada daerah persawahan Separi III dan IV difungsikan sebagai saluran pembuang limpasan air hujan dan kelebihan air dari petak tersier.sistem drainase permukaan saluran terbuka dengan penampang trapesium. Bentuk saluran trapesium dipilih karena stabilitas kemiringan dindingnya dapat disesuaikan dengan material/bahan pembentuk tubuh saluran. Kata kunci : Dimensi saluran, saluran irigasi primer dan sekunder, bentuk saluran trapesium.
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Bedient, Richard, and Michael Frame. "Carrying surfaces for return maps of averaged logistic maps." Computers & Graphics 31, no. 6 (2007): 887–95. http://dx.doi.org/10.1016/j.cag.2007.06.001.
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BRAUN, THOMAS, and JORGE A. LISBÔA. "CHARACTERIZATION OF HOMOCLINIC CHAOS IN A GLOW DISCHARGE THROUGH RETURN MAPS." International Journal of Bifurcation and Chaos 04, no. 06 (1994): 1483–93. http://dx.doi.org/10.1142/s0218127494001155.
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We show that homoclinic chaos in the current of a DC electrical discharge is easily characterized through return maps. We derive the same information from a Poincaré section map, a time-of-flight map, and a next maximal amplitude map. The presence of a homoclinic orbit in the phase space of our system is responsible for the equivalence of the three kinds of return maps.
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Zingaro, Marina, Renaud Hostache, Marco Chini, Domenico Capolongo, and Patrick Matgen. "A Localized Particle Filtering Approach to Advance Flood Frequency Estimation at Large Scale Using Satellite Synthetic Aperture Radar Image Collection and Hydrodynamic Modelling." Remote Sensing 16, no. 12 (2024): 2179. http://dx.doi.org/10.3390/rs16122179.
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This study describes a method that combines synthetic aperture radar (SAR) data with shallow-water modeling to estimate flood hazards at a local level. The method uses particle filtering to integrate flood probability maps derived from SAR imagery with simulated flood maps for various flood return periods within specific river sub-catchments. We tested this method in a section of the Severn River basin in the UK. Our research involves 11 SAR flood observations from ENVISAT ASAR images, an ensemble of 15 particles representing various pre-computed flood scenarios, and 4 masks of spatial units corresponding to different river segmentations. Empirical results yield maps of maximum flood extent with associated return periods, reflecting the local characteristics of the river. The results are validated through a quantitative comparison approach, demonstrating that our method improves the accuracy of flood extent and scenario estimation. This provides spatially distributed return periods in sub-catchments, making flood hazard monitoring effective at a local scale.
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BOISSY, CORENTIN, and ERWAN LANNEAU. "Dynamics and geometry of the Rauzy–Veech induction for quadratic differentials." Ergodic Theory and Dynamical Systems 29, no. 3 (2009): 767–816. http://dx.doi.org/10.1017/s0143385708080565.
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AbstractInterval exchange maps are related to geodesic flows on translation surfaces; they correspond to the first return maps of the vertical flow on a transverse segment. The Rauzy–Veech induction on the space of interval exchange maps provides a powerful tool to analyze the Teichmüller geodesic flow on the moduli space of Abelian differentials. Several major results have been proved using this renormalization. Danthony and Nogueira introduced in 1988 a natural generalization of interval exchange transformations, namely linear involutions. These maps are related to general measured foliations on surfaces (whether orientable or not). In this paper we are interested by such maps related to geodesic flow on (orientable) flat surfaces with ℤ/2ℤ linear holonomy. We relate geometry and dynamics of such maps to the combinatorics of generalized permutations. We study an analogue of the Rauzy–Veech induction and give an efficient combinatorial characterization of its attractors. We establish a natural bijection between the extended Rauzy classes of generalized permutations and connected components of the strata of meromorphic quadratic differentials with at most simple poles, which allows us, in particular, to classify the connected components of all exceptional strata.
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CHERNOV, N., R. MARKARIAN, and S. TROUBETZKOY. "Invariant measures for Anosov maps with small holes." Ergodic Theory and Dynamical Systems 20, no. 4 (2000): 1007–44. http://dx.doi.org/10.1017/s0143385700000560.
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We study Anosov diffeomorphisms on surfaces with small holes. The points that are mapped into the holes disappear and never return. In our previous paper we proved the existence of a conditionally invariant measure $\mu_+$. Here we show that the iterations of any initially smooth measure, after renormalization, converge to $\mu_+$. We construct the related invariant measure on the repeller and prove that it is ergodic and K-mixing. We prove the escape rate formula, relating the escape rate to the positive Lyapunov exponent and the entropy.
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Ciliberto, Ciro, Thomas Dedieu, and Edoardo Sernesi. "Wahl maps and extensions of canonical curves and K3K3 surfaces." Journal für die reine und angewandte Mathematik (Crelles Journal) 2020, no. 761 (2020): 219–45. http://dx.doi.org/10.1515/crelle-2018-0016.
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AbstractLet C be a smooth projective curve (resp. {(S,L)} a polarized {K3} surface) of genus {g\geqslant 11}, with Clifford index at least 3, considered in its canonical embedding in {\mathbb{P}^{g-1}} (resp. in its embedding in {|L|^{\vee}\cong\mathbb{P}^{g}}). We prove that C (resp. S) is a linear section of an arithmetically Gorenstein normal variety Y in {\mathbb{P}^{g+r}}, not a cone, with {\dim(Y)=r+2} and {\omega_{Y}=\mathcal{O}_{Y}(-r)}, if the cokernel of the Gauss–Wahl map of C (resp. {\operatorname{H}^{1}(T_{S}\otimes L^{\vee})}) has dimension larger than or equal to {r+1} (resp. r). This relies on previous work of Wahl and Arbarello–Bruno–Sernesi. We provide various applications.
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GUTIÉRREZ, J. M., A. IGLESIAS, J. GÜÉMEZ, and M. A. MATÍAS. "SUPPRESSION OF CHAOS THROUGH CHANGES IN THE SYSTEM VARIABLES THROUGH POINCARÉ AND LORENZ RETURN MAPS." International Journal of Bifurcation and Chaos 06, no. 07 (1996): 1351–62. http://dx.doi.org/10.1142/s0218127496000771.
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The present paper introduces a new chaos suppression method that is able to stabilize N- dimensional flows by perturbing the state variables in a discrete way when the flow crosses a suitably chosen Poincaré section. Two versions of the method are presented, depending on whether the perturbations are introduced on a proportional or an additive fashion. The perturbations are applied to the corresponding N−1-dimensional Poincaré map, or, in the case of strongly dissipative systems, to a suitable one-dimensional Lorenz map. The method is applied to two different three-variable flows: Rössler spiral chaos model and an isothermal three-variable autocatalator model introduced by Peng et al.
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Aulia, Nur, Irawan Alham, and Paharuddin. "Evaluation of Drainage Network System (Case Study of Pangkajene Kepulauan State Agricultural Polytechnic Campus Area)." Indonesian Journal of Contemporary Multidisciplinary Research 2, no. 6 (2023): 1295–308. http://dx.doi.org/10.55927/modern.v2i6.7039.
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The purpose of this research is to identify the condition of highway drainage channels and evaluate the existing highway drainage network system in accommodating runoff discharge, channel dimensions and flow direction in channels that occur inundation in the Pangkajene Islands State Agricultural Polytechnic Campus area which is expected to help solve flooding problems in the area. The research method used is descriptive quantitative, which is a method of calculation and description of the results of field data processing. Secondary data collection includes; rainfall data for the last 10 years, obtained from the Department of Resources; topographic maps, drainage network maps and situation maps, obtained from the Politani Pangkep Campus planning section. Primary data collection is obtained from direct measurements in the field using a Waterpass measuring instrument to measure elevation and channel length. The results of this study found that the drainage capacity < 2-year and 5-year return period Plan Flood Discharge, so planning is needed to increase drainage capacity
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CHERNOV, N., R. MARKARIAN, and S. TROUBETZKOY. "Conditionally invariant measures for Anosov maps with small holes." Ergodic Theory and Dynamical Systems 18, no. 5 (1998): 1049–73. http://dx.doi.org/10.1017/s0143385798117492.
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We study Anosov diffeomorphisms on surfaces in which some small ‘holes’ are cut. The points that are mapped into those holes disappear and never return. We assume that the holes are arbitrary open domains with piecewise smooth boundary, and their sizes are small enough. The set of points whose trajectories never enter holes under the past iterations of the map is a Cantor-like union of unstable fibers. We establish the existence and uniqueness of a conditionally invariant measure on this set, whose conditional distributions on unstable fibers are smooth. This generalizes previous works by Pianigiani, Yorke, and others.
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Rezayi, F., A. Bahremand, V. B. Shaikh, M. T. Dasturani, and M. Tajbakhsh. "ASSA Models and Gis Integration in the Determination of Flooding Point in Different Return Periods." Cercetari Agronomice in Moldova 52, no. 1 (2019): 91–105. http://dx.doi.org/10.2478/cerce-2019-0010.
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Abstract The quantitative and qualitative management of urban runoff is a very complicated, and the importance of it is added every day. Regardless of the economic and social impacts, water engineers always need to know how to respond to a city’s drainage system against different climatic conditions. In this research, the combination of ASSA and GIS models in the returns periods of 2, 5, 10, 50 years were used to determine the flooding points in the 9th district of Mashhad municipality. First, the watershed boundaries, canals and nodes maps was extracted from the GIS environment. Then, the ASSA model was simulated for a one hour design for a different return period; the outputs of the model were analyzed in the GIS software environment. The results showed that with increasing rainfall return period, 2806 nodes in underground and superficial networks of 114, 178 and 226 nodes were flooded and inundation during the return periods of 2, 5, 50, 10 years, respectively. Field surveys, existing elevation digital maps of the urban runoff network and simulations have shown that the main cause of inundation is the small size of the cross section of the duct, as well as the low slope in some parts of the network. Adaptation of the results of the simulation of rainfall-induced waterlogging in the study area with what happens every year confirms indicates the correctness of the simulations of the model. Moreover, simulation results of the model also showed that there is a good agreement between the simulated results and the measurement.
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Safriani, Meylis, Astiah Amir, and M. Faisi Ikhwali. "Evaluation of Krueng Tripa River Capacity in Ujung Krueng Village, Nagan Raya Regency, Indonesia." IOP Conference Series: Earth and Environmental Science 1203, no. 1 (2023): 012033. http://dx.doi.org/10.1088/1755-1315/1203/1/012033.
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Abstract Flood events are very common in the lowlands as often happens in Ujong Krueng Village, Tripa Makmur District. This study aims to determine the magnitude of the design flood discharge using the Nakayasu method and evaluating the cross-sectional capacity of the Krueng Tripa River in Ujong Krueng Village. The data used are both primary and secondary. Primary data consists of measurements of river slope, river flow velocity, river depth and river width, while secondary data consists of rainfall data, Krueng Tripa watershed maps and Krueng Tripa River situation maps. The results of the design flood discharge calculation using the Nakayasu method show that the 2-year return period (RP) is 3237.46 m3/s, the 5-year RP is 4389.53 m3/s, the 10-year RP is 5177.08 m3/s, the 10-year RP is 5177.08 m3/s, the 25-year RP is 6199.32 m3/s, the 50-year RP is 6979.04 m/s, and the 100-years RP is 7778.23 m3/s. From the results of hydraulic analysis on the section of the Krueng Tripa river in Ujong Krueng Village using the HEC-RAS 6.1.0 software, it shows that in the 2-year return period, on pias 1, 7 and 8 experienced overflows on both sides while on pias 2, 3, 4, 5 and 6 only overflow on the right side. In the return periods of 5th, 10th, 25th, 50th - year and 100th, all the streams had overflowed, the highest overflow reached 4.84 m, while the lowest overflow reached 0.30 m.
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Nyrtsov, M. V., M. E. Fleis, and A. I. Sokolov. "Meridian section projections: a new class of the triaxial ellipsoid projections." Geodesy and Cartography 968, no. 2 (2021): 11–22. http://dx.doi.org/10.22389/0016-7126-2021-968-2-11-22.
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Historically the conformal projections have been used for mapping not only the Earth, but other celestial bodies as well. Their application enables preserving the shape of the relief features on the maps, which is extremely important for various analyses of celestial bodies’ surfaces. For many small bodies of the Solar system the International Astronomical Union recommends to apply a triaxial ellipsoid as a reference surface. But if the conformal projections for the reference surfaces of a sphere and an ellipsoid of revolution already exist, obtaining these projections for a triaxial ellipsoid will be significantly complicated, and the task of preserving the shape of relief features still actual. In general, the article deals with cylindrical and azimuthal projections of the meridian section for global mapping the celestial body surface in accordance with the idea formulated by prof. L. M. Bugaevsky. The projections are implemented for mapping of Phobos, moon of Mars.
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Engel, Maximilian, and Christian Kuehn. "A Random Dynamical Systems Perspective on Isochronicity for Stochastic Oscillations." Communications in Mathematical Physics 386, no. 3 (2021): 1603–41. http://dx.doi.org/10.1007/s00220-021-04077-z.
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AbstractFor an attracting periodic orbit (limit cycle) of a deterministic dynamical system, one defines the isochron for each point of the orbit as the cross-section with fixed return time under the flow. Equivalently, isochrons can be characterized as stable manifolds foliating neighborhoods of the limit cycle or as level sets of an isochron map. In recent years, there has been a lively discussion in the mathematical physics community on how to define isochrons for stochastic oscillations, i.e. limit cycles or heteroclinic cycles exposed to stochastic noise. The main discussion has concerned an approach finding stochastic isochrons as sections of equal expected return times versus the idea of considering eigenfunctions of the backward Kolmogorov operator. We discuss the problem in the framework of random dynamical systems and introduce a new rigorous definition of stochastic isochrons as random stable manifolds for random periodic solutions with noise-dependent period. This allows us to establish a random version of isochron maps whose level sets coincide with the random stable manifolds. Finally, we discuss links between the random dynamical systems interpretation and the equal expected return time approach via averaged quantities.
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Taylor, G. C. "Use of Spline Functions for Premium Rating by Geographic Area." ASTIN Bulletin 19, no. 1 (1989): 91–122. http://dx.doi.org/10.2143/ast.19.1.2014917.
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AbstractThe paper gives details of a case study in the premium rating of a Householders Contents insurance portfolio. The rating is performed by the fitting of bivariate spline functions to a version of operating ratio described in Section 3.The use of bivariate splines requires a small amount of mathematical equipment, which is developed in Section 4. The fitting of splines, using regression is carried out in Sections 5 and 6, where the numerical results are given, including some assessment of goodness-of-fit.Contour maps of the spline surfaces are also given, and used for the selection of geographic areas used for premium rating purposes. These are compared with the areas, past and present, actually used by the insurer concerned.
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Németh, Péter, Ágnes Csanády, Katalin Papp, et al. "The Investigation of Thin Protecting Layers on Roughened Galvanized Steel Surfaces Produced by Different Coating Methods." Materials Science Forum 589 (June 2008): 433–38. http://dx.doi.org/10.4028/www.scientific.net/msf.589.433.
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Protective, chromate substitute thin layers on roughened galvanized surfaces produced at OCAS (Arcelor, Belgium) were characterized and compared using Scanning Electron Microscopy (SEM+EDS), Atomic Force Microscopy (AFM), Nanoindentation and X-ray Photoemission Spectroscopy (XPS). EDX maps, line scans and point analyses obtained at various places of the surfaces have shown differences between the CVD and silane nanolayers in the matter of thickness distribution and composition. At cross-section specimens the thickness of the layers could be shown. The hardness differences caused by layer thickness variations are hard to follow by nanoindentation as the penetration depth of the indenter is much larger than the thickness of the coatings. XPS measurements can distinguish between the chemical states of silicon in CVD and silane coatings.
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Ward, P. J., H. de Moel, and J. C. J. H. Aerts. "How are flood risk estimates affected by the choice of return-periods?" Natural Hazards and Earth System Sciences 11, no. 12 (2011): 3181–95. http://dx.doi.org/10.5194/nhess-11-3181-2011.
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Abstract. Flood management is more and more adopting a risk based approach, whereby flood risk is the product of the probability and consequences of flooding. One of the most common approaches in flood risk assessment is to estimate the damage that would occur for floods of several exceedance probabilities (or return periods), to plot these on an exceedance probability-loss curve (risk curve) and to estimate risk as the area under the curve. However, there is little insight into how the selection of the return-periods (which ones and how many) used to calculate risk actually affects the final risk calculation. To gain such insights, we developed and validated an inundation model capable of rapidly simulating inundation extent and depth, and dynamically coupled this to an existing damage model. The method was applied to a section of the River Meuse in the southeast of the Netherlands. Firstly, we estimated risk based on a risk curve using yearly return periods from 2 to 10 000 yr (€ 34 million p.a.). We found that the overall risk is greatly affected by the number of return periods used to construct the risk curve, with over-estimations of annual risk between 33% and 100% when only three return periods are used. In addition, binary assumptions on dike failure can have a large effect (a factor two difference) on risk estimates. Also, the minimum and maximum return period considered in the curve affects the risk estimate considerably. The results suggest that more research is needed to develop relatively simple inundation models that can be used to produce large numbers of inundation maps, complementary to more complex 2-D–3-D hydrodynamic models. It also suggests that research into flood risk could benefit by paying more attention to the damage caused by relatively high probability floods.
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Abdulrahiem, Dr Juhaina, Marwa Zakaria, Isalam Mohammad, et al. "FACTORS THAT DELAY RETURN TO WORK OF COVID-19 POSITIVE HEALTH CARE WORKERS AT KSMC , MARCH- AUGUST 2020." International Journal of Research -GRANTHAALAYAH 9, no. 8 (2021): 368–81. http://dx.doi.org/10.29121/granthaalayah.v9.i8.2021.4195.
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This study about Factors that delay return to work of COVID-19 positive health care workers at King Saud medical city Riyadh Saudi Arabia.2020 Coronaviruses (CoV) are a large family of RNA viruses that cause illnesses ranging from the common cold to more severe diseases such as Middle East respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome (SARS-CoV). The aim of this study is to determine the factors that delay return to return to work among COVID-19 positive HCPs also to study the relationship of the associated risk factors and the delay in return to work among positive COVID-19 HCPs and to minimize the delay in return to work among COVID-19 positive HCPs which will maintain staffing levels to provide adequate care to all patients. Health care professional is defined as all staff in the health care facility involved in the provision of care for a COVID-19 infected patient, including those who have been present in the same area as the patient, as well as those who may not have provided direct care to the patient, but who have had contact with the patient’s body fluids, potentially contaminated items or environmental surfaces. Sampling method: The design of the sampling for this study will be Stratified Random Sampling (StRS) cross section study. This study about Factors that delay return to work of COVID-19 positive health care workers at King Saud medical city Riyadh Saudi Arabia mc.2020 Coronaviruses (CoV) are a large family of RNA viruses that cause illnesses ranging from the common cold to more severe diseases such as Middle East respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome (SARS-CoV). The aim of this study is to determine the factors that delay return to return to work among COVID-19 positive HCPs also to study the relationship of the associated risk factors and the delay in return to work among positive COVID-19 HCPs and to minimize the delay in return to work among COVID-19 positive HCPs which will maintain staffing levels to provide adequate care to all patients. Health care professional is defined as all staff in the health care facility involved in the provision of care for a COVID-19 infected patient, including those who have been present in the same area as the patient, as well as those who may not have provided direct care to the patient, but who have had contact with the patient’s body fluids, potentially contaminated items or environmental surfaces. Sampling method: The design of the sampling for this study will be Stratified Random Sampling (STRS) cross section study will use SPSS to analysis.
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De Brouwer, S., D. H. Edwards, and T. M. Griffith. "Simplification of the quasiperiodic route to chaos in agonist-induced vasomotion by iterative circle maps." American Journal of Physiology-Heart and Circulatory Physiology 274, no. 4 (1998): H1315—H1326. http://dx.doi.org/10.1152/ajpheart.1998.274.4.h1315.
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We have shown that the patterns of vasomotion induced by histamine in isolated rabbit ear resistance arteries can be described in terms of iterative circle maps that model the dynamics of coupled nonlinear oscillators. Cyclopiazonic acid (CPA), an inhibitor of the sarcoplasmic reticulum Ca2+-adenosinetriphosphatase pump, consistently transformed chaotic behavior into characteristic periodic oscillations known as mixed-mode responses, which consist of mixtures of large- and small-amplitude excursions and represent frequency-locked states. Quasiperiodicity, which reflects the interaction of oscillators with incommensurate frequencies, was also observed, although in a smaller number of experiments. The patterns of mixed-mode complexes found at different CPA concentrations allowed the derivation of firing numbers, i.e., number of large oscillations/sum of number of small and large oscillations, and the sequences in which they emerged conformed to Farey arithmetic. Two-dimensional return maps derived by Poincaré section of phase space representations of the dynamics were used to compute the mean number of rotations per iteration on the circle, i.e., the winding number. Plots of winding number against firing number revealed a devil’s staircase-type structure. Experiments with verapamil, a voltage-operated L-type Ca2+-channel antagonist, confirmed that influx of extracellular Ca2+was essential to sustain chaos, quasiperiodicity, and mixed-mode responses. Nonlinear coupling between cytosolic and membrane events in rabbit ear arteries thus results in a self-organized dynamics that collapses to that predicted by the theory of simple circle maps.
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Liu, Xian-Yu, An-Bo Li, Hao Chen, Yan-Qing Men, and Yong-Liang Huang. "3D Modeling Method for Dome Structure Using Digital Geological Map and DEM." ISPRS International Journal of Geo-Information 11, no. 6 (2022): 339. http://dx.doi.org/10.3390/ijgi11060339.
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Geological maps have wide coverage with low acquisition difficulty. When other geological survey data are scarce, they are a valuable source of geological structure information for geological modeling. However, for structures with large deformation, geological map information has difficulty meeting the requirement of its 3D geological modeling. Therefore, this paper takes the dome structure as an example to explore a 3D modeling method based on geological maps, DEM and related geological knowledge. The method includes: (1) adaptively calculating the attitude of points on the stratigraphic boundaries; (2) inferring and generating the bottom boundary of the model from the attitude data of the boundary points; (3) generating the model interface constrained by Bézier curves based on the bottom boundary; (4) generating the top and bottom surfaces of the stratum; and (5) stitching each surface of the geological body to generate the final dome model. Case studies of the dome in Wulongshan in China and the Richat structure in Mauritania show that this method can build a solid model of the dome based only on geological maps and DEM data, whose morphological features are basically consistent with those embodied in the section view or the model generated by traditional methods.
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La Torre, Valentina, Anna Sajina, Andy D. Goulding, et al. "Estimating Galaxy Parameters with Self-organizing Maps and the Effect of Missing Data." Astronomical Journal 167, no. 6 (2024): 261. http://dx.doi.org/10.3847/1538-3881/ad3821.
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Abstract The current and upcoming large data volume galaxy surveys require the use of machine-learning techniques to maximize their scientific return. This study explores the use of Self-Organizing Maps (SOMs) to estimate galaxy parameters with a focus on handling cases of missing data and providing realistic probability distribution functions for the parameters. We train an SOM with a simulated mass-limited lightcone assuming a ugrizY JHK s +IRAC data set, mimicking the Hyper Suprime-Cam Deep joint data set. For parameter estimation, we derive SOM likelihood surfaces considering photometric errors to derive total (statistical and systematic) uncertainties. We explore the effects of missing data, including which bands are particularly critical to the accuracy of the derived parameters. We demonstrate that the parameter recovery is significantly better when the missing bands are “filled in” rather than if they are completely omitted. We propose a practical method for such recovery of missing data.
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Ziana, Ziana, Azmeri Azmeri, Alfiansyah Yulianur, Ella Meilianda, and Mubarak Mubarak. "Mapping of Flood Inundation and Eco-hydraulic Analyses to Minimize Food Discharge in Tributaries." Aceh International Journal of Science and Technology 12, no. 1 (2023): 126–38. http://dx.doi.org/10.13170/aijst.12.1.31120.
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Eco-hydraulic analyses begin with the arrangement of tributaries. This research aimed to minimize the discharge of flood run-off downstream and map the flood inundation by spatial analysis uses DEMNAS data and mapping of flood inundation areas using ArcGIS. Analysis of return period flood points using HEC-RAS version 5.0.7. The data needed is the cross section of the river, the distance between the sections, the Manning's roughness number, the return period flood discharge and the slope of the river. The integration between topographic maps, watersheds and flood water levels can display areas that are potentially affected by inundation floods, so that the flood inundation limits and flood inundation areas can be calculated. This research examined proper eco-hydraulics design so that it could reduce discharge, identify locations prone to flooding, and describe the magnitude of the flood impact quantitatively. The results eco-hydraulic method obtained the design border width of 100 m, the condition before the existing river border arrangement was carried out, the inundation height was 0.30 – 1.13 m and after the river border arrangement the discharge could be reduced to 113.09 – 209 m3/s and the inundation height is 0 – 0.31 m. Based on the research results, it is known that border arrangement can provide benefits for flood control measures.
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Ogundeji, Ayodele, and Ezugwu Nnamdi. "Ecological Impact Assessment of Permanent Site of Federal Polytechnic Oko Using Topographic Survey Method." American Journal of Applied Mathematics 12, no. 5 (2024): 183–99. http://dx.doi.org/10.11648/j.ajam.20241205.18.
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Topographic survey based ecological impact assessment provides a mechanism for data integration, development, management and output presentation in a spatial environment. This research involved incorporating spatial data of all salient points at the Permanent Site of Federal Polytechnic, Oko, Anambra state to find a solution to the erosion menace. Differential Global Positioning System (DGPS) receiver was used to acquire spatial data of buildings, roads, spot height, drainages, catchment pits, etc. The topographic data were processed using ArcGIS software to analyze and produce the topographic maps. Presentations from the topographic survey revealed that the catchment topography runs between 160m – 198m height above the datum, the total area of the catchment area being 216320.653m2, perimeter is 2604.449m and the length of the mainstream is 1125.428m. Topographic maps of the area were used to assess the impact of the ecology on the area of study by analyzing the built up area, surface roughness, impervious and pervious surfaces. Hydraulic design of the drainage using best hydraulic section principle for most economic section to carry the flow was determined to solve the erosion problems in the catchment area. The flow rate obtained was 2.55m3/s and dimensions of the channel to be 1.1m depth and 2.2m width. The design of the selected structural members was done to mitigate against the erosion menace in the study area.
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Scheffer, Louis K. "Investigating nearby exoplanets via interstellar radar." International Journal of Astrobiology 13, no. 1 (2013): 62–68. http://dx.doi.org/10.1017/s147355041300030x.
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AbstractInterstellar radar is a potential intermediate step between passive observation of exoplanets and interstellar exploratory missions. Compared with passive observation, it has the traditional advantages of radar astronomy. It can measure surface characteristics, determine spin rates and axes, provide extremely accurate ranges, construct maps of planets, distinguish liquid from solid surfaces, find rings and moons, and penetrate clouds. It can do this even for planets close to the parent star. Compared with interstellar travel or probes, it also offers significant advantages. The technology required to build such a radar already exists, radar can return results within a human lifetime, and a single facility can investigate thousands of planetary systems. The cost, although too high for current implementation, is within the reach of Earth's economy.
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Halavataya, K. A., K. V. Kozadaev, and V. S. Sadau. "Adjusting videoendoscopic 3D reconstruction results using tomographic data." Computer Optics 46, no. 2 (2022): 246–51. http://dx.doi.org/10.18287/2412-6179-co-910.
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Videoendoscopic and tomographic research are the two leading medical imaging solutions for detecting, classifying and characterizing a wide array of pathologies and conditions. However, source information from these types of research is very different, making it hard to cross-correlate them. The paper proposes a novel algorithm for combining results of based on 3D surface reconstruction methods. This approach allows to align separate parts of two input 3D surfaces: surface obtained by applying bundle adjustment-based 3D surface reconstruction algorithm to the endoscopic video sequence, and surface reconstructed directly from separate tomographic cross-section slice projections with regular density. Proposed alignment method is based on using local feature extractor and descriptor algorithms by applying them to the source surface normal maps. This alignment allows both surfaces to be equalized and normalized relative to each other. Results show that such an adjustment allows to reduce noise, correct reconstruction artifacts and errors, increase representative quality of the resulting model and establish correctness of the reconstruction for hyperparameter tuning.
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Horishnyi, Pavlo. "THE MALE OPILLIA MORPHOLOGICAL ANALYSIS OF RELIEF." PROBLEMS OF GEOMORPHOLOGY AND PALEOGEOGRAPHY OF THE UKRANIAN CARPATHIANS AND ADJACENT AREAS 02, no. 13 (2021): 37–47. http://dx.doi.org/10.30970/gpc.2021.2.3547.
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The Male Opillia morphological analysis of relief has been carried out on the basis of constructed morphological maps on the scale of 1:50 000 for the key part of the Zubra – Sukhodilka watershed. The morphological mapping lies in taking into consideration dotted, linear and areal elements of relief. The absolute heights of the study area are between 255 and 405 meters high (highland level – 330-405 m, lowland level (main valleys) – 255–290 m). The relative heights of the Zubra River Basin are between 50 and 100 m, Davydivka–Sukhodilka River Basin – between 70 and 130 m. Four main linear elements of relief are thalwegs, combes, convex and concave bends. The most common linear elements are thalwegs. They are the bottoms of shallow river valleys, arroyos, and largest gullies. The main direction of linear reach is diagonal (NW–SE). The convex bends delineate the highland surfaces and flats. They also separate gentle watershed slopes from steep valley slopes. The concave bends usually are the borders of greater river valleys. These elements of relief are entirely isolated, which demonstrates a discernible contact between slopes and bottoms. The combes are the least common linear elements. It is connected with the roundness and alignment of highland surfaces and a small number of sudden changes of directions of horizontals on the straightforward slopes. The dotted elements of relief are submitted as high points. Most high points are rounded. The areal elements of relief are submitted as highland (watershed) surfaces, flats, bottoms of valleys, and different shapes of slopes, according to the cross-section and plan. The highland surfaces are quite noticeable. Their absolute height is estimated between 350 and 380 m. The highland surfaces don’t occupy the upper parts of interfluves; they are divided into two parts. The shape of highland surfaces is strongly stretched along. The nature of morphology of the surface of relief is weakly curved and flat according to the cross-section, and weakly curved and wavy according to the longitude. The surfaces of the flats are subhorizontal elements of relief, which are an intermediate position in relief. These surfaces are bounded by one or two concave bends. The bottoms of the valleys of the Zubra are 190–770 m in width, the Davydivka – 190–770 m, the Sukhodilka – 140-820 m. The shape of the cross-section is predominantly flat, and only in shallow valleys it’s partly concave. The slopes occupy much of the study area so that they prevail over subhorizontal surfaces. The convex slopes prevail; the least common are concave slopes. Key words: morphological analysis of relief; morphological map; elements of relief; Male Opillia.
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Biondi, Maurizio, Paola D’Alessandro, Walter De Simone, and Mattia Iannella. "DBSCAN and GIE, Two Density-Based “Grid-Free” Methods for Finding Areas of Endemism: A Case Study of Flea Beetles (Coleoptera, Chrysomelidae) in the Afrotropical Region." Insects 12, no. 12 (2021): 1115. http://dx.doi.org/10.3390/insects12121115.
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Areas of endemism (AoEs) are a central area of research in biogeography. Different methods have been proposed for their identification in the literature. In this paper, a “grid-free” method based on the “Density-based spatial clustering of applications with noise” (DBSCAN) is here used for the first time to locate areas of endemism for species belonging to the beetle tribe Chrysomelidae, Galerucinae, Alticini in the Afrotropical Region. The DBSCAN is compared with the “Geographic Interpolation of Endemism” (GIE), another “grid-free” method based on a kernel density approach. DBSCAN and GIE both return largely overlapping results, detecting the same geographical locations for the AoEs, but with different delimitations, surfaces, and number of detected sinendemisms. The consensus maps obtained by GIE are in general less clearly delimited than the maps obtained by DBSCAN, but nevertheless allow us to evaluate the core of the AoEs more precisely, representing of the percentage levels of the overlap of the centroids. DBSCAN, on the other hand, appears to be faster and more sensitive in identifying the AoEs. To facilitate implementing the delimitation of the AoEs through the procedure proposed by us, a new tool named “CLUENDA” (specifically developed is in GIS environment) is also made available.
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Buczek, Michał, Martyna Paszek, and Anna Szafarczyk. "Application of Laser Scanning for Creating Geological Documentation." E3S Web of Conferences 35 (2018): 04001. http://dx.doi.org/10.1051/e3sconf/20183504001.
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A geological documentation is based on the analyses obtained from boreholes, geological exposures, and geophysical methods. It consists of text and graphic documents, containing drilling sections, vertical crosssections through the deposit and various types of maps. The surveying methods (such as LIDAR) can be applied in measurements of exposed rock layers, presented in appendices to the geological documentation. The laser scanning allows obtaining a complete profile of exposed surfaces in a short time and with a millimeter accuracy. The possibility of verifying the existing geological cross-section with laser scanning was tested on the example of the AGH experimental mine. The test field is built of different lithological rocks. Scans were taken from a single station, under favorable measuring conditions. The analysis of the signal intensity allowed to divide point cloud into separate geological layers. The results were compared with the geological profiles of the measured object. The same approach was applied to the data from the Vietnamese hard coal open pit mine Coc Sau. The thickness of exposed coal bed deposits and gangue layers were determined from the obtained data (point cloud) in combination with the photographs. The results were compared with the geological cross-section.
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Shavers, E., and L. Stanislawski. "STREAMS DO WORK: MEASURING THE WORK OF LOW-ORDER STREAMS ON THE LANDSCAPE USING POINT CLOUDS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4 (September 19, 2018): 573–78. http://dx.doi.org/10.5194/isprs-archives-xlii-4-573-2018.
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<p><strong>Abstract.</strong> The mutable nature of low-order streams makes regular updating of surface water maps necessary for accurate representation. Low-order streams make up roughly half the streams in the conterminous United States by length, and small inaccuracies in stream head location can result in significant error in stream reach, order, and density. Reliable maps of stream features are vital for hydrologic modeling, ecosystem research, and boundary monitoring. High resolution digital elevation models derived from lidar data have shown promise in low order stream modeling yet forested high relief landscapes and low relief agricultural areas remain challenging. Here we present early results from research analyzing lidar point clouds to identify features and patterns that may be used in low-order stream identification and classification in challenging geographic conditions. This work has identified characteristics derived from point clouds that correlate with the presence of streams and stream heads and show promise for mapping small streams. In low topographic relief agricultural areas, cross sections collected at regular intervals along drainage channels extracted as 3D lines show a significant jump in value and variance of profile curvature standard deviation at stream heads. In high relief areas, observations show potential for stream mapping by identifying trends in riparian zone structure. Lidar return point density from riparian vegetation under 30 feet tall dips in the vicinity of intermittent stream heads. Also seen is an increase in point density above 60 feet downstream of stream heads. The trends found here likely reflect a change in vegetation structure relative to the presence of streams.</p>
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Niyazov, T. Kh. "On the prospects of exploration of oil-gas deposits in non-anticline traps in North Absheron upheaval zone." Azerbaijan Oil Industry, no. 01 (January 15, 2022): 4–9. http://dx.doi.org/10.37474/0365-8554/2022-01-4-9.
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Considering the fact that the oil-gas fields in non-anticline traps are the urgent problem, the geological structure of the lower section of Productive Series of oil-gas prospective zone of North Absheron upheaval has been specified based on the comparative analysis of the data from the recent seismic surveys using the well data. The structural maps of Gala, Lower and Upper Girmaki suites surfaces have been developed. As a result of the research surveys, the position of junction points of the horizons and the state of fringe lines in the temporary and dynamic deep sections of the seismic profiles crossing through the wings of the most of the structures (predominantly in South-West wings), located in the upheaval zone and for the formation of oil-gas traps of non-anticline type, five areas with favorable geological conditions have been selected.
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Ishaq, M. S., and L. Bernstein. "On the speed of progressive waves in gust-tunnels of the QMC-type." Aeronautical Journal 91, no. 907 (1987): 321–32. http://dx.doi.org/10.1017/s0001924000021448.
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SummaryIn the Queen Mary College gust-tunnels, unsteady flows are generated by oscillating flaps attached to the downstream upper and lower surfaces of the contraction nozzle of a semi-open test section, open-return, low-speed wind-tunnel. The flow perturbations produced on the mainstream of velocityU∞, are of the travelling-wave type, with wave-velocityQ. Attention is drawn to the contradictory early measurements ofQ/U∞. New data are presented which showQ/U∞apparently diminishing along the tunnel axis from a high value near the nozzle exit to an asymptotic value of about 0·6 far downstream. Using a digital phase meter especially developed for the purpose it is shown that the explanation for this behaviour lies in the two-dimensional nature of the wave process in the region of the flaps.
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Bañuelos, R., and B. Øksendal. "Exit times for elliptic diffusions and BMO." Proceedings of the Edinburgh Mathematical Society 30, no. 2 (1987): 273–87. http://dx.doi.org/10.1017/s0013091500028339.
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In 1948 P. Lévy formulated the following theorem: If U is an open subset of the complex plane and f:U → ℂ is a nonconstant analytic function, then f maps a 2-dimensional Brownian motion Bt (up to the exit time from U) into a time changed 2-dimensional Brownian motion. A rigorous proof of this result first appeared in McKean [22]. This theorem has been used by many authors to solve problems about analytic functions by reducing them to problems about Brownian motion where the arguments are often more transparent. The survey paper [8] is a good reference for some of these applications. Lévy's theorem has been generalized, first by Bernard, Campbell, and Davie [5], and subsequently by Csink and Øksendal [7]. In Section 1 of this note we use these generalizations of Lévy's theorem to extend some results about BMO functions in the unit disc to harmonic morphisms in ℝn to holomorphic functions in ℂn and to analytic functions on Riemann surfaces. In Section 2, we characterize the domains in ℝn which have the property that the expected exit time of elliptic diffusions is uniformly bounded as a function of the starting point. This extends a result of Hayman and Pommerenke [15], and Stegenga [24] about BMO domains in the complex plane.
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Kirk, R. Gary, Michael E. Gates, Aaron J. Provance, and Ping Lee. "Quantitative X-ray Images Calculated on the Basis of Mass and Volume." Microscopy and Microanalysis 3, no. 6 (1997): 512–19. http://dx.doi.org/10.1017/s1431927697970392.
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Abstract: Quantitative X-ray microanalysis is used to obtain the elemental compositions of tissues and cells. Concentrations are calculated on the basis of volume (mmolL−1 of packed cells) and mass (mmolkg−1 dry weight). Elemental maps are obtained by using a computer to control the position of a beam in an electron microscope and to record the signals from the scanning transmission electron microscope (STEM) and energy dispersive X-ray spectrometer (EDS) X-ray detectors. These X-ray images provide better visualization of elemental distributions than ``spot'' mode analysis by analyzing thousands of spots sequentially. When concentrations are determined on the basis of volume, it is assumed that the section thickness created during cryosectioning, and shrinkage during freeze-drying of a frozen section, are uniform. These assumptions have been examined with a nucleated red blood cell model. Even distributions of cytoplasmic Fe and K, which we observed, can only occur if cryomicrotomy produces sections with smooth surfaces and uniform thickness. In addition, by using bone marrow cryosections we have found that the relative shrinkage between nucleated and non-nucleated cells is similar. Therefore, the assumptions made about volume calculations do appear to be reasonable under the conditions used in this study.
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Tropin, S. L., N. G. Surkova, and L. R. Yurenkova. "Improving the methodology of teaching the discipline «Engineering graphics»." Glavnyj mekhanik (Chief Mechanic), no. 1 (January 1, 2023): 57–63. http://dx.doi.org/10.33920/pro-2-2301-08.
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The article presents an innovative methodology for teaching the discipline «Engineering Graphics», aimed at increasing the level of preparedness of students of engineering specialties to perform drawings of parts of complex geometric shapes. Students experience the greatest difficulties when applying dimensions due to the fact that they do not have sufficient knowledge of the production technology of practical experience. The novelty of the technique lies in the application of some provisions of the section of geometry called «Graph Theory». Training maps have been developed that contain algorithms of actions for the stage of applying dimensions to drawings. Particular attention of students is drawn to the knowledge gained in the study of the section of descriptive geometry «Surfaces». As the experience of introducing the new methodology has shown, thanks to the algorithms that organize the sequence of actions of students when applying dimensions to drawings, it is possible not only to help students overcome difficulties in completing an educational task. In addition, since the «Graph Theory» has some elements of the game, it is possible to captivate students with the task. It would not be superfluous to quote the words of the French writer Anatole France (1844-1924): «Only by having fun, they learn.»
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Arditto, P. A. "A SEQUENCE STRATIGRAPHIC STUDY OF THE CALLOVIAN FLUVIO-DELTAIC TO MARINE SUCCESSION WITHIN THE ZOCA REGION." APPEA Journal 36, no. 1 (1996): 269. http://dx.doi.org/10.1071/aj95015.
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This paper presents the results and conclusions of an integrated sequence stratigraphic study of the Callovian marine succession across area 'A' of the Zone of Cooperation (ZOCA). This study utilised wireline log and conventional core data from within ZOCA 91–1 and ZOCA 91–12, and incorporated trade data from adjacent permits, to generate a rational depositional model for the succession. Three distinct third-order sequences have been recognised from the detailed correlation of regional flooding surfaces recognised on wireline log motifs calibrated against conventional core and biostratigraphy. The base of the oldest third-order sequence includes section previously referred to as Plover Formation, and roughly corresponds to the W.digitata/W.indotata zone boundary. The Callovian Unconformity within the ZOCA region is thus relegated to a third-order sequence boundary or disconformity. The term Elang Formation is proposed for this Callovian succession which comprises three third-order sequences mappable across ZOCA. The well-type section for the Elang Formation is Elang-1, and an additional well reference section would be Elang-2, as both these wells contain significant and complementary cored section.Detailed sedimentological studies on conventional core reveal that the Elang Formation comprises a succession of coastal plain to nearshore marine sediments, ranging from low sinuosity fluvial channel, fluvial-dominated deltaic, proximal low sinuosity estuarine channel and distal outer bay sediments. Only minor wave-dominated, open marine shoref ace intervals were interpreted, most of the cored intervals indicating a fluvially-domi-nated shoreline with minimal wave reworking. Isopach and per cent sand maps generated for each third-order sequence comprising the Elang Formation illustrate the successive sediment distribution patterns across ZOCA during the progressive marine transgression from the top of the fluvio-deltaic Plover Formation to the base of the offshore marine Lower Flamingo Group. The sand-trend maps for the three sequences which comprise the Elang Formation indicate a fluvial/estuarine-dominated delta system, sourced from the region of the Laminaria Field, AC/P8, building east and southeast out across the ZOCA region. A modern analogue of this delta system in both size and sedimentation style may be the Brahmaputra/Ganges Delta of East Bengal.
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Zhang, Dongxiao, Michael J. McPhaden, and William E. Johns. "Observational Evidence for Flow between the Subtropical and Tropical Atlantic: The Atlantic Subtropical Cells*." Journal of Physical Oceanography 33, no. 8 (2003): 1783–97. http://dx.doi.org/10.1175/2408.1.
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Abstract This study determines the mean pathways and volume transports in the pycnocline and surface layer for water flowing between the subtropical and tropical Atlantic Ocean, using potential vorticity, salinity, geostrophic flow maps on isopycnal surfaces, and surface drifter velocities. In both hemispheres, subducted salinity maximum waters flow into the Tropics in the pycnocline along both interior and western boundary pathways. The North Atlantic ventilating trajectories are confined to densities between about 23.2 and 26.0 σθ, and only about 2 Sv (Sv ≡ 106 m3 s–1) of water reaches the Tropics through the interior pathway, whereas the western boundary contributes about 3 Sv to the equatorward thermocline flow. Flow on shallower surfaces of this density range originates from the central Atlantic near 40°W between 12° and 16°N whereas flow on the deeper surfaces originates from near 20°W just off the coast of Africa at higher latitudes. The pathways skirt around the potential vorticity barrier located under the intertropical convergence zone and reach their westernmost location at about 10°N. In the South Atlantic, about 10 Sv of thermocline water reaches the equator through the combination of interior (4 Sv) and western boundary (6 Sv) routes in a slightly higher density range than in the North Atlantic. Similar to the North Atlantic, the shallower layers originate in the central part of the basin (along 10°–30°W at 10°–15°S) and the deeper layers originate at higher latitudes from the eastern part of the basin. However, the ventilation pathways are spread over a much wider interior window in the Southern Hemisphere than in the Northern Hemisphere that at 6°S extends from 10°W to the western boundary. The equatorward convergent flows in the thermocline upwell into the surface layer and return to the subtropics through surface poleward divergence. As much as 70% of the tropical Atlantic upwelling into the surface layer is associated with these subtropical circulation cells, with the remainder contributed by the warm return flow of the large-scale thermohaline overturning circulation.
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Hill, MJ, GE Donald, PJ Vickery, and EP Furnival. "Integration of satellite remote sensing, simple bioclimatic models and GIS for assessment of pastoral development for a commercial grazing enterprise." Australian Journal of Experimental Agriculture 36, no. 3 (1996): 309. http://dx.doi.org/10.1071/ea9960309.
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Satellite imagery, climatic, edaphic and topographic data, and a simple bioclimatic model were used to analyse the pastoral potential of a large cattle grazing enterprise, 'Cooplacurripa', on the central coast of New South Wales. Landsat Thematic Mapper and Spot XS satellite images were processed to create pasture growth status maps describing timbered and cleared areas, and priority areas for phosphorus fertiliser application. A digital elevation model was used to describe slope and aspect, and as a basis for interpolation of monthly surfaces of rainfall, temperature, radiation and evaporation from the Australian Climate Surfaces. These data were combined with a simple growth index model to create production surfaces for tropical, subtropical and temperature pasture types. The property was classified into zones defined by the seasonal growth patterns of the 3 pasture classes. The database was used to identify potential areas for further pasture improvement by a series of logical rules and map overlays to define pasture suitability for currently timbered areas with a slope of less than 20�. The northern section of the property with the highest rainfall, best suitability for temperate pasture and good road access was chosen for land capability and fauna impact studies on the basis of this analysis. The study provides an example of the application of spatial data to practical management issues in pastoral agriculture.
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Fu, Tianliang, Xiangtao Deng, Xiuhua Tian, Guohuai Liu, and Zhaodong Wang. "Experimental study on temperature drop during roller quenching process of large-section ultra-heavy steel plate." Science Progress 104, no. 2 (2021): 003685042110093. http://dx.doi.org/10.1177/00368504211009330.
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Large-section ultra-heavy steel plates feature low cooling rate of central part during quenching process, as well as great differences in texture and performance along thickness direction. Wet jet impingement quenching test apparatus and multi-channel temperature recorder were developed to explore the temperature drop characteristics and its influential factors of ultra-heavy steel plate. The temperature drop curves of plates with different thickness (160, 220, and 300 mm) and weight (23–43 tons) were recorded during the quenching process, accompanied with the exploration on distribution rules of temperature gradient, heat flux density and cooling rate along thickness direction under different water volumes (9000–9400 m3/h) and pressures (0.4–0.8 MPa), upon which the three-dimensional inverse heat conduction model, surface heat transfer coefficient model and thermophysical parameter model were established using finite element and optimization methods. The overall results indicate the symmetric heat transfer between the upper and lower plate surfaces can be realized, when the water flow ratios of the upper and lower surfaces were 1:1.25 and 1:1.4 under pressures of 0.8 MPa and 0.4 MPa, respectively. The “temperature return” phenomenon was accompanied with changing heat flux density of wall surface of 220 mm- and 300 mm-thick plates. The lowest cooling rate along thickness direction appeared at 1/4 thickness position for the 160 mm- and 220 mm- thick plates during quenching, which was attributable to the synergy between heat flux density and temperature gradient. This work may pave a way for improving the cooling rate and quenching uniformity of ultra-heavy steel plates along thickness direction.
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CHUA, LEON O., GIOVANNI EGIDIO PAZIENZA, LASZLO ORZO, VALERY I. SBITNEV, and JINWOOK SHIN. "A NONLINEAR DYNAMICS PERSPECTIVE OF WOLFRAM'S NEW KIND OF SCIENCE PART IX: QUASI-ERGODICITY." International Journal of Bifurcation and Chaos 18, no. 09 (2008): 2487–642. http://dx.doi.org/10.1142/s0218127408021853.
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Our scientific odyssey through the theory of 1-D cellular automata is enriched by the definition of quasi-ergodicity, a new empirical property discovered by analyzing the time-1 return maps of local rules. Quasi-ergodicity plays a key role in the classification of rules into six groups: in fact, it is an exclusive characteristic of complex and hyper Bernoulli-shift rules. Besides introducing quasi-ergodicity, this paper answers several questions posed in the previous chapters of our quest. To start with, we offer a rigorous explanation of the fractal behavior of the time-1 characteristic functions, finding the equations that describe this phenomenon. Then, we propose a classification of rules according to the presence of Isles of Eden, and prove that only 28 local rules out of 256 do not have any of them; this result sheds light on the importance of Isles of Eden. A section of this paper is devoted to the characterization of Bernoulli basin-tree diagrams through modular arithmetic; the formulas obtained allow us to shorten drastically the number of cases to take into consideration during numerical simulations. Last but not least, we present some theorems about additive rules, including an analytical explanation of their scale-free property.
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Gozzini, Giovanni. "The global system of international migrations, 1900 and 2000: a comparative approach." Journal of Global History 1, no. 3 (2006): 321–41. http://dx.doi.org/10.1017/s1740022806003020.
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The aim of this paper is to compare international migrations in two different periods of history, both of them marked by a rapid increase in the trend: the first period runs from 1870 to 1914, and the second from 1965 to 2000. Historical and current migration system maps are compared, together with their different combinations of push and pull factors, and of coerced and free migrations. The various repercussions that international migrations have on demographic structure and on the economic systems of the sending and receiving countries are counterbalanced by a number of significant analogies that occur at the microlevel (individual and community) of the mechanisms governing the decision to migrate, and of migrants’ identities and behavioural patterns. The final section shows that migrants in both periods retain ties to both their old and new countries (as indicated by remittances and return migration), despite the major obstacles that stand in the way of the free circulation of international migrants today. This suggests that an analysis of migration systems, emphasizing ongoing interactions of various sorts between sending and receiving areas, is superior to either a model based on the presumption that assimilation will occur over time or one which presumes an irreducible ‘multiculturalism’.
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Redecki, Michał, and Bronisław Gosowski. "The influence of the torsional restraint of crane column brackets on their critical load capacity." MATEC Web of Conferences 262 (2019): 09009. http://dx.doi.org/10.1051/matecconf/201926209009.
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The paper presents the results of numerical parametric studies conducted on laterally restrained steel I-columns with a single stepped asymmetric change in their cross-section. Such elements are used as a part of the outermost columns in the transversal system of steel halls with cranes. The columns are usually braced along their length with wall girts, which in a properly structured hall system have a significant effect on the columns’ load bearing capacity and determine their axis of rotation. The main aim of the presented studies is to determine the impact of parameters, such as longitudinal load distribution on the upper and lower segment of the column, the number of pointed lateral bracings and their distance to a column's external flange, and also the application of torsional restraint on the critical load capacity. Results are presented as surfaces or contour maps, in which the ordinates represent the critical loads with regards to the analysed parameters. The paper ends with practical conclusions.
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Putranto, Muhammad Luthfisal, Muhamad Fahmy Saputra, Mochamad Ridwan Pratama, Dio Damas Permadi, Nita Kurnita Sari, and Utamy Sukmayu Saputri. "Drainage analysis on the Pondoktisuk Kebonkai Sta 1+700-1+800 road section, Nagrak District, Sukabumi Regency." BIO Web of Conferences 148 (2024): 02026. https://doi.org/10.1051/bioconf/202414802026.
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This study aims to determine the rainfall distribution calculations, the consistency of rainfall data, and the drainage channel dimensions on the Pondoktisuk-Kebonkai road section Sta 1+700 – 1+800 in Nagrak District, Sukabumi Regency. The methodology used includes literature review, field observation, collection of primary data such as daily rainfall data over the past 14 years and catchment area data, as well as secondary data including field documentation and location maps. Hydrological analysis was conducted through maximum rainfall calculation, design rainfall calculation, consistency data testing, probability distribution, distribution fitting tests, rainfall intensity analysis, rainwater storage volume calculation, concentration time calculation, flood discharge analysis, and open drainage dimension calculation. The results show that the calculated water flow velocity is 1.323 m/s with a slope of 0.20%. Based on the checking process, the design meets the standard requirements for allowable water flow velocity (1.50 m/s) and slope (1%). A comparison of the planned drainage slope with the existing land slope at the study site indicates that the calculated slope is lower than the existing slope (1%), thus requiring the design of a flow breaker. The rainfall distribution calculation for the Pondoktisuk-Kebonkai road section Sta 1+700 – 1+800 in Nagrak District, Sukabumi Regency, represents all the methods used, with the Gumbel method showing the highest rainfall in all return periods. The rainfall data consistency calculation indicates that Q/n^0.5 and R/n^0.5 are smaller than their critical values, at 0.32 and 0.51 respectively, thus the data is deemed consistent. The drainage channel dimension of 80x80x100 cm with a thickness of 10 cm meets the requirements, with a calculated water flow velocity of 1.323 m/s and a slope of 0.20%, lower than the allowable limits, necessitating the inclusion of a flow breaker.
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Spelke, Elizabeth S., and Sang Ah Lee. "Core systems of geometry in animal minds." Philosophical Transactions of the Royal Society B: Biological Sciences 367, no. 1603 (2012): 2784–93. http://dx.doi.org/10.1098/rstb.2012.0210.
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Research on humans from birth to maturity converges with research on diverse animals to reveal foundational cognitive systems in human and animal minds. The present article focuses on two such systems of geometry. One system represents places in the navigable environment by recording the distance and direction of the navigator from surrounding, extended surfaces. The other system represents objects by detecting the shapes of small-scale forms. These two systems show common signatures across animals, suggesting that they evolved in distant ancestral species. As children master symbolic systems such as maps and language, they come productively to combine representations from the two core systems of geometry in uniquely human ways; these combinations may give rise to abstract geometric intuitions. Studies of the ontogenetic and phylogenetic sources of abstract geometry therefore are illuminating of both human and animal cognition. Research on animals brings simpler model systems and richer empirical methods to bear on the analysis of abstract concepts in human minds. In return, research on humans, relating core cognitive capacities to symbolic abilities, sheds light on the content of representations in animal minds.