Miracle-dz/UniFAR-FTUs huggingface dataset:
Intertidal DEM Generation Using Satellite Radar Interferometry

High resolution intertidal DEM is a basic material for science research like sedimentation/erosion by ocean current, and is invaluable in a monitoring of environmental changes and practical management of coastal wetland. Since the intertidal zone changes rapidly by the inflow of fluvial debris and tide condition, remote sensing is an effective tool for observing large areas in short time. Although radar interferometry is one of the well-known techniques for generating high resolution DEM, conventional repeat-pass interferometry has difficulty on acquiring enough coherence over tidal flat due to the limited exposure time and the rapid changes in surface condition. In order to overcome these constraints, we tested the feasibility of radar interferometry using Cosmo-SkyMed tandem-like one-day data and ERS-ENVISAT cross tandem data with very short revisit period compared to the conventional repeat pass data. Small temporal baseline combined with long perpendicular baseline allowed high coherence over most of the exposed tidal flat surface in both observations. However the interferometric phases acquired from Cosmo-SkyMed data suffer from atmospheric delay and changes in soil moisture contents. The ERS-ENVISAT pair, on the other hand, provides nice phase which agree well with the real topography, because the atmospheric effect in 30-minute gap is almost same to both images so that they are cancelled out in the interferometric process. Thus, the cross interferometry with very small temporal baseline and large perpendicular baseline is one of the most reliable solutions for the intertidal DEM construction which requires very accurate mapping of the elevation.
Reversals of the orthoenstatite‐clinoenstatite transition at high pressures and high temperatures

The MgSiO3 orthoenstatite-clinoenstatite (OEn-CEn) phase boundary has been reversed between pressures of 70 and 110 kbar and temperatures of 900°C and 1700°C with a split-sphere anvil apparatus (USSA-2000). Starting materials contained PbO-PbF2 (1∶1) flux to promote equilibration of the charges and eliminate a potential effect of deviatoric stresses on the phase boundary. The phase boundary separating orthoenstatite from clinoenstatite at high pressures and temperatures can be described by the equation P (kbar) = 0.031 T (°C)+50. Our results are consistent with previous unreversed determinations of the boundary at these high-pressure, high-temperature conditions. However, the dP/dT slope determined in the present study is much smaller than that implied by earlier experimental studies of the orthoenstatite/low clinoenstatite boundary at low pressures and temperatures. We propose that the clinoenstatite observed at high pressures and temperatures is a new high-pressure clinoenstatite phase which is possibly an analogue of MgGeO3 clinopyroxene.
Stability limits of hydrous minerals in sediment and mid‐ocean ridge basalt compositions: Implications for water transport in subduction zones

Phase relationships in hydrated natural sediment and mid-ocean ridge basalt (MORB) compositions were investigated experimentally from 6 to 15 GPa and 700°C to 1400°C in order to determine the stability of hydrous phases in subducting slabs and to constrain reactions resulting in the release of water from subduction zones to the mantle. Phengite and hydrous aluminum silicates (topaz-OH and phase egg) are stable in the sediment composition at depths greater than 150 km and constitute H2O reservoirs. Similarly, lawsonite is an H2O reservoir in MORB composition at depths greater than 150 km. According to mass balance calculations based on experimental run products, the weight proportions of phengite and H2O at 6 GPa in the sediment are about 50% and 2%, respectively. At pressures from 8 to 12 GPa, topaz-OH (Al2SiO4(OH)2) appears as the hydrous mineral, and the sediment retains about 0.5–0.7 wt % H2O. At higher pressures, phase egg (AlSiO3(OH)) appears as the hydrous phase with a large stability field. The H2O content in the sediment is about 0.5 wt% at pressures greater than 12 GPa. In natural MORB compositions, lawsonite is the hydrous phase at pressures lower than 10 GPa. About 1 wt%, H2O in the MORB composition is retained by lawsonite at 6 GPa and 800°C. Above 6 GPa, a lawsonite-out reaction is controlled by compositional changes of garnet and clinopyroxene. If the oceanic crust descends with an overlying sediment layer, water can be carried down into the transition zone by the sediment. The amount of transported water is controlled by the chemical compositions of the subducting sediments. Water in the MORB layer can be stored to 300 km in lawsonite for a cold subduction zone geotherm. Water release at depths greater than 200 km through progressive lawsonite breakdown can hydrate the overlying mantle, causing the generation of a peridotite region including hydrous phases (chondrodite, clinohumite, phase A, and phase E). If this hydrous peridotite is dragged down by the descending oceanic crust, water can be transported into the transition zone by the subduction process. The amount of transported water is controlled by the thermal state of the slab and the chemical composition of MORB.
The Fluid Evolution Related to Talc Mineralization in the Hwanggangri Area, South Korea

Abstract: Scores of talc deposits distributed in the Hwanggangri Mineralized Zone, South Korea are interpreted to have resulted from the contact metamorphic process related to the igneous intrusion of the Muamsa Granite. Talc usually occurs as an alteration product from tremolite, which is crystallized during the prograde stage. It commonly forms fine–grained, fibrous aggregates, or pseudomorphs after tremolite, and abundant tremolite is included as impurities in the talc ore. Quantitative X‐ray diffraction analysis has shown that the ores can be divided into three types depending on the concentrations of talc; talc‐tremolite ore (talc > 50 %), tremolite‐talc ore (10 % < talc < 50 %), and tremolite (talc < 10 %) ores. Oxygen isotope compositions of those talc ores become higher from 10.9–12.1 through 11.6–12.3 to 11.9–13.2% with increasing tremolite concentrations, while hydrogen isotope compositions are not so variable, –73 to –69%. The high value of the calculated δ18OH2O of the fluids equilibrated with the tremolite may have resulted from the mixing of magmatic water with 18O–enriched CO2 evolved from the decarbonation reaction during the prograde stage. However, as the decarbonation reaction ceased during the retrograde stage, the inferred oxygen isotope compositions of talc‐forming fluids show similar values to those of the igneous fluids.
Current rates of convergence across the central Andes : Estimates from continuous GPS observations

We present velocity solutions for 16 continuous GPS (CGPS) stations located in South America in a geodetic reference frame that nominally fixes the craton or stable core of this continent. The RMS horizontal velocity of 8 stations located within the craton is 1.3 mm/yr. Three CGPS stations located in Chile between about 33° S and 20° S have velocities in the range 19–24 mm/yr. These motions manifest current rates of convergence across the southern limb of the Central Andes. The IGS station in Arequipa, Peru (at 16.5°S) in the northern limb of the orocline, however, has a velocity of just 10 mm/yr.
The vector of wavelet-fractal and instance analysis

According to Wavelet analytical principles and Fractal theories, we put forward a new physical quantity: the Vector of Wavelet-Fractal. We built up a new kind of method that analyses and calculates the nonlinear time series. Applying the ways and means we analysis rain-storm's nonlinear characteristic in the satellite remote sensing information, its result fitted with the variety tendency of actual rainfall in 1998, Wu Han.
Modeling the near‐freezing dichothermal layer in the Sea of Okhotsk and its interannual variations

The hydrographic structure in the Sea of Okhotsk is unique, especially regarding the existence of the Okhotsk Dichothermal Layer (ODTL), a near-freezing layer beneath a highly seasonal surface layer. The formation of this cold layer is linked to extensive sea-ice coverage in winter. Observations revealed strong signals of interannual variations of winter sea-ice extent in this marginal sea and indicated a likely linkage with observed changes in temperature and salinity fields. In this paper, a 1.5-dimensional coupled ocean-ice model is used to study the formation of the ODTL and to test how external forcing fields affect this process. The model, despite its simplicity, simulates well the temperature and the salinity profiles that resemble observations. It is found that the ODTL is replenished during winter convection. During warm seasons, meltwater creates a very stable surface layer that effectively prevents mixing between warm surface water and cold water in the ODTL. Thus the seasonal variation of sea ice plays a leading role in maintaining the ODTL structure. Although the minimum temperature feature of the ODTL is robust in the model, the hydrographic structure in the Sea of Okhotsk is sensitive to interbasin exchanges with the North Pacific Ocean and the Sea of Japan and to some other external forcing fields. More interestingly, an interannual oscillation arises from this model even though the model forcing excludes any interannual variation. We concluded that such oscillation is due to the model's subharmonic response to the annual cycle of the forcing fields. It suggests that the seemingly zero-net-gain annual cycle of winter freezing and spring melting is actually an effective process transporting salt from surface to deeper layers and thus the coupled ocean-ice's subharmonic response to this annual cycle is an important source for low-frequency variations.
A new method for ship classification and recognition

This paper proposes a fast and robust algorithm for classification and recognition of ships based on the Principal Component Analysis (PCA) method. The three-dimensional ship models are achieved by modeling software of MultiGen, and then they are projected by Vega simulating software for two-dimensional ship silhouettes. The PCA method as against the Back-Propagation (BP) neural network method for simulated ship recognition using training and testing experiments, we can see that there is a sharp contrast between them. Some recognition results from simulated data are presented, the correct recognition rate of PCA method improved rapidly for each of the five ship types than that of neural network method, the number of times a ship type is recognized as one of the other ships is reduced greatly.
Baroclinic adjustment in Drake Passage driven by tropical Pacific forcing

The time series of high‐quality hydrographic measurements of the ACC in Drake Passage is revisited to investigate the extent of baroclinic adjustment in the region on time scales of up to two decades. We find that substantial adjustment of the upper kilometer of northern Drake Passage has occurred on interannual to decadal time scales, driven primarily by tropical Pacific forcing via the poleward propagation of boundary waves. The decadal‐scale signal consists of a marked deepening of isopycnals (by ∼200 m between the early 1990s and the late 2000s), and reflects ENSO‐forced wind‐driven baroclinic changes over an extensive region of the eastern South Pacific.
Meridional eddy sensible heat fluxes in the extremes of the Pacific/North American teleconnection pattern

Abstract The geographical distribution of meridional eddy sensible heat transport in the extremes of the Pacific/North American (PNA) teleconnection pattern is examined and compared to heat transport occurring in conjunction with other regional teleconnections. The heat fluxes are estimated using 700-mb air temperatures and geostrophic winds during 12 winter months when the PNA index reaches its highest values (large-amplitude standing ridge and trough pattern over North America) and during 12 months when it is lowest (relatively zonal flow across the continent). The standing wave fluxes are generally largest in the positive PNA phase, especially across latitudes 45°–55°N, although the flux between 60°–75°N is not as great as in the negative phase, when poleward heat transport is strong over northern Canada and near Iceland. The largest spatial heat flux variations in the extremes of the PNA occur in areas with long-term climatological flux maxima and relatively large long-term standard deviations. These .
Electromagnetic imaging of a transpressional tectonics in SW Iberia

Forty‐one magnetotelluric soundings were carried out along a 200 km‐long profile (approximately NNE‐SSW) across the three major geotectonic units in SW Iberia. A model obtained from two‐dimensional inversion of the magnetotelluric data set reveals high conductivity zones in the middle‐lower crust (10–30 km). Two of these zones correspond to the transition between the main geotectonic units: one between the South Portuguese Zone and the Ossa Morena Zone, interpreted as having been caused by metasediments, and the other between the Ossa Morena Zone and the Central Iberia Zone associated with a shear zone and metasediments. Another high conductivity anomaly related to black shales with major graphite impregnation was detected within the Ossa Morena Zone. The resistive features, located preferentially in the upper crust (1–10 km), coincide with gabbroic and granitic complexes.
Master Computer Science

Lightning is a natural weather hazard still claiming thousands of lives globally each year. Prevention of fatalities due to lightning via rules and regulation is common practice in society but comes with costs and delays. Skillful prediction of the occurrence of lightning is therefore an important aspect of weather forecasting. Traditionally, lightning occurrence is predicted by the use of physics-based numerical weather prediction models. However, such model simulations are computationally expensive and tend to not incorporate the latest observational information into the prediction. Here, we follow a different approach by exploring the potential of the use of learning algorithms applied to satellite observations of clouds over the Caribbean region for providing skillful short-term lightning predictions for the following 35 minutes (so-called “nowcasting”). Lightning is associated with a particular type of weather and clouds (thunderstorms). Geostationary satellites nowadays provide continuously updated near-real-time high-quality cloud information at high spatial resolutions. Hence, the possibility exists that satellite observations contain valuable information about potential near-future lightning occurrences.We train well-known models like ResNet50 and MobileNetV3 as well as a basic convolutional neural network (CNN) individually on 100,000 patches with an 8km by 8km resolution, taken from the original satellite images over the entire BES islands (Bonaire, Saint Eustatius, and Saba) region, to achieve 0.99 accuracy and 0.99 AUC score. By performing a convolution-like operation on patches of the entire area satellite picture, we introduce a novel approach called FlaSH (Flash Score Heatmap). For the entire satellite picture, FlaSH achieves an AUC score of 0.96, demonstrating its ability to precisely nowcast lightning.
Terrestrial ecosystems and the global biogeochemical silica cycle

Most research on the global Si cycle has focused nearly exclusively on weathering or the oceanic Si cycle and has not explored the complexity of the terrestrial biogeochemical cycle. The global biogeochemical Si cycle is of great interest because of its impact on global CO2 concentrations through the combined processes of weathering of silicate minerals and transfer of CO2 from the atmosphere to the lithosphere. A sizable pool of Si is contained as accumulations of amorphous silica, or biogenic silica (BSi), in living tissues of growing plants, known as phytoliths, and, after decomposition of organic material, as remains in the soil. The annual fixation of phytolith silica ranges from 60–200 Tmol yr−1 and rivals that fixed in the oceanic biogeochemical cycle (240 Tmol yr−1). Internal recycling of the phytolith pool is intense with riverine fluxes of dissolved silicate to the oceans buffered by the terrestrial biogeochemical Si cycle, challenging the ability of weathering models to predict rates of weathering and consequently, changes in global climate. Consideration must be given to the influence of the terrestrial BSi pool on variations in the global biogeochemical Si cycle over geologic time and the influence man has had on modifying both the terrestrial and aquatic biogeochemical cycles.
Summer surface waters in the Gulf of California: Prime habitat for biological N2 fixation

We report significant rates of dinitrogen (N2) fixation in the central basins of the Gulf of California (GC) during July–August 2005. Mixing model estimates based upon δ15N values of particulate matter in the surface mixed layer indicate that N2 fixation provides as much as 35% to 48% of the phytoplankton‐based nitrogen demand in the central Guaymas and Carmen basins. Microscopic analyses identify the responsible genera as the N2‐fixing endosymbiont, Richelia intracellularis, with lesser contributions from the large nonheterocystous diazotroph Trichodesmium. Analyses of remotely sensed chlorophyll a and sea surface temperature indicate that primary production levels are elevated in regions of the GC where oceanographic conditions are ideal in summertime for the growth of N2‐fixing organisms. These findings suggest that biological N2 fixation must be taken into account when assessing past and present nitrogen dynamics in this environmentally important region.
61.4: Active Crosstalk Reduction on Multi‐View Displays Using Eye Detection

Multi‐view displays have some problems in the quality of images, while they provide glasses‐free systems. Especially inter‐view crosstalk is the most critical factor to deteriorate the image quality and cause visual fatigue under large depths. We propose a method to provide clear images appropriate to the positions of the observer's eyes. In a subpixel group, using the visibility profiles of the subpixels expressing each view, we can determine the subpixel values to express a certain color at a certain direction. This can compensate color distortion caused by slanted lenticular lens and expand the observable area using the repeated regions neighboring the main region.
Evaluation of the AR4 Climate Models’ Simulated Daily Maximum Temperature, Minimum Temperature, and Precipitation over Australia Using Probability Density Functions

Abstract The coupled climate models used in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change are evaluated. The evaluation is focused on 12 regions of Australia for the daily simulation of precipitation, minimum temperature, and maximum temperature. The evaluation is based on probability density functions and a simple quantitative measure of how well each climate model can capture the observed probability density functions for each variable and each region is introduced. Across all three variables, the coupled climate models perform better than expected. Precipitation is simulated reasonably by most and very well by a small number of models, although the problem with excessive drizzle is apparent in most models. Averaged over Australia, 3 of the 14 climate models capture more than 80% of the observed probability density functions for precipitation. Minimum temperature is simulated well, with 10 of the 13 climate models capturing more than 80% of the observed probability densit.
Optimal Energy Procurement for Geo-distributed Data Centers in Multi-timescale Electricity Markets

In this paper, we study cascading failures in power grids under the nonlinear AC and linearized DC power flow models. We numerically compare the evolution of cascades after single line failures under the two flow models in four test networks. The cascade simulations demonstrate that the assumptions underlying the DC model (e.g., ignoring power losses, reactive power flows, and voltage magnitude variations) can lead to inaccurate and overly optimistic cascade predictions. Particularly, in large networks the DC model tends to overestimate the yield (the ratio of the demand supplied at the end of the cascade to the initial demand). Hence, using the DC model for cascade prediction may result in a misrepresentation of the gravity of a cascade.
Relationship between green leaf biomass volumetric density and ERS-2 SAR backscatter of four vegetation formations in the semi-arid zone of Israel

Relationships between ERS-2 SAR backscatter and the biophysical properties of four Mediterranean vegetation formations (forest, shrubs, dwarf shrubs and herbaceous vegetation) were assessed. Low correlation was found between ERS-2 SAR backscatter and both aboveground biomass and LAI. However, significantly higher correlation (r =0.92) was found between ERS-2 SAR backscatter and a new index of Green leaf biomass Volumetric Density (GVD). These results stress the dominant influence of leaves in the uppermost part of the vegetation layer on ERS-2 SAR backscatter.
Factors associated with dropping out of the program for Bachelor ’ s and Licentiate ’ s Degrees in Mathematics Teaching at the Universidad Nacional de Costa Rica ( UNA ) : Evidence from the 2016 Student Cohort

This study addresses the problem of dropouts among students in the program for Bachelor’s and Licentiate’s Degrees in Mathematics Teaching of the Universidad Nacional de Costa Rica. It is intended to describe the 2016 cohort of students in the program, and identify factors associated with academic dropout through semi-structured telephone interviews conducted with dropouts. Among the variables considered for the descriptive analysis are the grades students obtained in their high school of origin, their admission exam scores, standardized scores, an index of social development, social class, sex, type of school financing, scholarship status, place of residence, and the number of credits for which a student enrolled and how many of them he or she earned. The investigation found that there are differences between dropouts and non-dropouts in terms of admission exam scores and the number of credits that students enrolled for and earned. In addition, dropping out is more frequent among women, students without a scholarship, and students from urban areas. Eleven dropouts were interviewed, and three of these cases were analyzed in detail; final results showed that vocational and economic factors, teaching methods, and unmet expectations of students about the program are the main factors associated with dropping out.