Miracle-dz/UniFAR-FTUs huggingface dataset:
Spatio-temporal variability of drought over northern China and its relationships with Indian-Pacific sea surface temperatures

Monthly precipitation data from 66 rain gauge stations in northern China are analyzed for the period 1976–2011. Variations in droughts and wet spells are described using the standardized precipitation index (SPI). Empirical orthogonal functions and a global wavelet spectral analysis are applied to capture modes of spatio-temporal variability in droughts over northern China. Time series of monthly sea surface temperatures (SST) and the Multivariate El Niño Southern Oscillation Index (MEI) are presented, and cross wavelet and wavelet coherence transforms are carried out to investigate possible mechanisms behind variations in droughts and wet spells. From 1976 onwards, the northern parts of northern China have experienced an increase in the frequency of droughts, while the southern parts of northern China have experienced a decrease in the frequency of droughts. The north–south variability of droughts and wet spells is characterized by interannual timescales of 3.3 years and 7.0–11.0 years. The former timescale is closely related with the MEI, while the latter is closely related with sea surface temperature anomalies (SSTA) over the North Pacific. Most parts of northern China experienced an increase in the frequency of droughts during the periods 1980–2000 and 2004–present, and a decrease in the frequency of droughts during the period 2000–2004. The variability of drought in northern China peaks at timescales of 16.0–32.0 and 3.5–4.0 years. The first of these timescales shows a significant correlation with SSTA over the Indian Ocean. The eastern parts of northern China have experienced a decrease in the frequency of droughts since 1976, while the western parts of northern China have experienced an increase in the frequency of droughts. The east–west variability of droughts and wet spells is characterized by interannual timescales of 3.3-8.0 years, which are related with SSTA over the Indian Ocean warm pool.
Experiments with Spears and Arrows on Animal Targets

AbstractDespite the considerable attention that archaeologists have given the formal and typological aspects of prehistoric projectile points, relatively little research has been done concerning their functional aspects. To better understand the effectiveness and penetrating characteristics of, and damage to, different projectile tips, an extensive experimental program was conducted. Both shaped and unmodified chert tips were hafted onto arrow- and spear-shafts and propelled into dead animals. The results led to recognition of differences in damage patterns, the importance of certain variables for projectile point longevity, and the penetration potential of specific kinds of projectile heads.
Comparison of an ℓ1-regression-based and a RANSAC-based planar segmentation procedure for urban terrain data with many outliers

For urban terrain data with many outliers, we compare an ℓ1-regression-based and a RANSAC-based planar segmentation procedure. The procedure consists of 1) calculating the normal at each of the points using ℓ1 regression or RANSAC, 2) clustering the normals thus generated using DBSCAN or fuzzy c-means, 3) within each cluster, identifying segments (roofs, walls, ground) by DBSCAN-based-subclustering of the 3D points that correspond to each cluster of normals and 4) fitting the subclusters by the same method as that used in Step 1 (ℓ1 regression or RANSAC). Domain decomposition is used to handle data sets that are too large for processing as a whole. Computational results for a point cloud of a building complex in Bonnland, Germany obtained from a depth map of seven UAV-images are presented. The ℓ1-regression-based procedure is slightly over 25% faster than the RANSAC-based procedure and produces better dominant roof segments. However, the roof polygonalizations and cutlines based on these dominant segments are roughly equal in accuracy for the two procedures. For a set of artificial data, ℓ1 regression is much more accurate and much faster than RANSAC. We outline the complete building reconstruction procedure into which the ℓ1-regression-based and RANSAC-based segmentation procedures will be integrated in the future.
Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl2=CCl2)

Tropospheric mixing ratios of CCl2=CCl2 were measured at remote surface locations in the Pacific between 71°N and 47°S during September and December of 1989, and March and June of 1990. The observed gradient of decreasing concentrations from the northern to southern hemisphere, and very low concentrations in the southern hemisphere throughout the year, indicates a predominant input from the northern hemisphere. Our seasonal measurements in the northern hemisphere showed maximum CCl2=CCl2 concentrations occurring in the late winter and minimum concentrations occurring in the late summer. This distinct seasonal variation is strongly coupled to the atmospheric abundance of hydroxyl radical, the only important species responsible for CCl2=CCl2 removal. Using the estimated global CCl2=CCl2 emissions the lifetime is calculated to be about 5.4 months which is in good agreement with the 4.0 month estimate obtained from the inverse ratio of its measured hydroxyl reaction rate constant compared with that of methylchloroform (CH3CCl3).
Compaction‐driven evolution of porosity and permeability in natural mudstones: An experimental study

This paper describes a series of experiments designed to investigate the influence of lithology on the compactional loss of porosity and permeability in mudstones. Two intact samples of London Clay with clay fractions of 40% and 67% were compacted to 33 MPa effective stress. Clay fraction, permeability, porosity, pore size distribution, and specific surface area were measured and their evolution was monitored throughout the compaction process. Electron microscopy was combined with mercury porosimetry to trace the collapse of the pore structure with increasing effective stress. In both cases, porosity loss occurred primarily by the collapse of large pores. This process is more obvious in the coarser-grained sample because throughout the compaction process it has a much broader range of pore radii and a much greater mean pore radius. Consistent with the pore size distributions, the permeability of the coarser sample ranges from ∼ 10−10 m s−1 to 10−12 m s−1 while that of the finer-grained sample ranges from ∼4 × 10−12 m s−1 to 5 × 10−14 m s−1 during progressive compaction from 2 to 33 MPa. The compressibility of the finer-grained sample is greater than that of the coarser-grained sample (0.15 as opposed to 0.07). However, in both cases the compressibility is much lower than that inferred for lithologically similar samples compacted over geological timescales. The demonstration that both porosity and lithology (clay fraction) influence the permeability of mudstones should allow the development of more realistic porosity-permeability relationships which take into account lithological variations exhibited by mudstones.
Climatological features of global multiple tropopause events

[1] This study examines various climatological features related to multiple tropopause events (MT events). The analysis is based on the lapse rate definition of the tropopause and is performed on a radiosonde data subset taken from the Integrated Global Radiosonde Archive database. The global statistics of MT events are analyzed, taking into consideration both their seasonal and geographical variations. Our results are in moderate qualitative agreement with those of earlier studies. They reinforce the analytical findings of other researchers, but at the same time highlight important differences in both the number and position of the maximum occurrence of MT events. We found a latitudinal band of multiple tropopause occurrence in the Northern Hemisphere and three centers in the Southern Hemisphere, which coincided with identified zones of maximum cyclogenesis. The climatological features of pressure, temperature, and vertical separation of MT events revealed the complexity of these phenomena, which behave very differently according to latitude and season.
Evaluation of vapor-phase nicotine and respirable suspended particle mass as markers for environmental tobacco smoke

Vapor-phase nicotine and respirable suspended particle mass (RSP) emissions from tobacco combustion were evaluated as markers for environmental tobacco smoke (ETS) in an environmental chamber and a field study. The chamber and field studies reported here indicate that vapor-phase nicotine is a suitable qualitative and quantitative marker for environmental tobacco smoke in the residential indoor environment
Determination of the effective thermal conductivity of granular materials under varying pressure conditions

[1] We report on thermal conductivity measurements performed on glass spheres of different grain sizes under varying pressure conditions ranging from 10−5 up to 1000 hPa. Glass spheres of 0.1 up to 4.3 mm were used as an analogue for the coarse-grained fractions of planetary regolith. From the obtained conductivity versus pressure data, sample pore sizes were derived and compared to estimated pore sizes. An increasing difference between derived and estimated pore size with increasing grain size was found. The behavior of the granular matter with decreasing pressure was analyzed by estimating the Knudsen number for the given system. The results indicate a high variability of the effective thermal conductivity for Martian conditions. Furthermore, the results imply that the thermal conductivity reaches a grain size-dependent, but pressure-independent, value for pressures below 0.01 hPa. For vacuum conditions a linear relation between grain size and effective thermal conductivity was found. Additionally, a mixture was analyzed, which showed a stronger decrease with gas pressure compared to the single-sized samples. From the pore size derived for the mixture an “effective” grain size composed of weighted mean of the mixture components was determined.
40Ar/39Ar thermochronology along a western Québec transect of the Grenville Province, Canada

Ar/Ar thermochronology on 24 hornblendes, 3 biotites, 2 muscovites and 2 K‐feldspars, collected along a 400 km‐long NW‐SE geotraverse through the Grenville Province in western Québec, is employed to provide time constraints on the intermediate and low temperature stages of cooling of part of the Grenville orogen. In the Grenville Front zone, the c. 1000 Ma time of exhumation previously established from thermobarometric and isotopic studies, is supported by the hornblende age data presented here. From 60 km to 160 km SE of the Front, reworked Archaean migmatites of the parautochthonous Réservoir Dozois terrane (RDT; 1004 Ma‐old metamorphic monazites) contain hornblendes with 972– 950 Ma cooling ages. Assuming metamorphic geotherms between 25 and 30 °C km−1, calculated cooling and unroofing rates are about 6 °C Ma−1 and 0.33 km Ma−1 in the P–T range 725 °C–800 MPa and 450 °C–400 MPa. Hornblendes from monocyclic rocks of the Mont‐Laurier and Morin terranes (MLT and MT; monazite ages c. 1165 Ma) give ages of about 1040 and 1010 Ma, respectively. Calculation of cooling‐unroofing rates from peak metamorphic conditions in this area is hampered by thermal perturbations associated with the still poorly dated Grenville collision which took place approximately between 1060 and 1020 Ma. Cooling ages of c. 900 Ma for muscovite and biotite and 860–810 Ma for K‐feldspar, show that cooling rates decreased to around 1.5 °C Ma−1 under retrograde greenschist facies conditions in the MLT. On a time vs. distance diagram, the hornblende data define several distinct age ranges, suggesting that each terrane had a characteristic thermal history. Thus, cooling was diachronous and probably non‐homogeneous throughout this segment of the Grenville orogen. The time‐lag between the cooling history of the parautochthon (972–950 Ma) and the allochthons (1040–1010 Ma) is compatible with an earlier (pre‐1040 Ma) peak of metamorphism in the allochthons. The Réservoir Cabonga allochthon was transported toward the NNW from its probable root zone in the MLT during the 1060–1020 Ma Grenvillian collision as a partially cooled slab. The remobilization of the Archaean parautochthon is attributed to this collision. In the Grenville Front zone, slightly older cooling ages and cooling rates initially faster than in the remaining part of the parautochthon are probably as a result of rapid (tectonic? ) exhumation shortly after collision. The minor delay (20–30 Ma) in unroofing of the MT compared to the adjacent MLT is most likely related to post‐1040 Ma extensional displacement along the Labelle shear zone. In terranes like those described above where metamorphism is diachronous, determination of cooling rates and the history of exhumation may be meaningless without a firm control on the regional structure. However, identification of contrasting cooling histories contributes to unravelling the independent movement of terranes.
Zinc, copper, and lead geochemistry of oceanic igneous rocks - ridges, islands, and arcs

Variations in the abundances of Zn, Cu, and Pb are found to be useful in identifying tectonic regimes and separating oceanisland basalts into enriched- and depleted-source categories. The average Zn, Cu, and Pb contents of normal mid-ocean ridge basalts (N-MORB) are 84, 70, and 0.35 ppm, respectively. Differences in average Zn contents for various ridges reflect more the varying degrees of differentiation than variations of Zn content in the source rocks. At a Mg# of 70, or Mg#70, which is taken to represent primitive MORB, many MORB sequences converge at a Zn content of 58 ± 6 ppm, which is close to the value for primitive mantle (50 ppm) and ordinary chondrites (∼55 ppm). Values of 0.1 to 0.15 ppm Pb in MORB at Mg#70, best defined at the superfast-spreading Southern East Pacific Rise, are similar to estimates of Pb in the primitive mantle (0.12 to 0.18 ppm). They also are near the lower end of the range for ordinary chondrites. The very slow spreading Southwest Indian Ocean Ridge has a sequence with hig.
Automatic Identification of Jetting Behavior in 3D Printing with Automatic Identification of Jetting Behavior in 3D Printing with Binary Classification and Anomaly Detection Binary Classification and Anomaly Detection

Consistently jetting different materials from the print head of a 3D printer is a key, yet challenging task in manufacturing processes. By using active machine learning, we can efficiently predict complex diagrams that illustrate the region of printing conditions under which “desirable jetting”, “jetting”, and “no jetting” of ink occurs for different substances. However, labeling the images of printed ink droplets that are fed to the active learning model can be time intensive. Therefore, it is ideal to use computer vision to automate the classification of this image data. This classification can be broken down into two steps. In the first step, we are interested in distinguishing between images that exhibit any jetting and those that show no jetting at all. To perform this binary classification, a convolutional neural network (CNN) is trained on a dataset consisting of both “jetting” and “no jetting” images. Because there is a relative lack of data exhibiting “no jetting”, data augmentation is applied in order to create a balanced number of images between the two classes and prevent bias towards the “jetting” class. In the second step, the differentiation between “desirable/consistent” and “inconsistent/satellite” jetting is made. “Incon-sistent/satellite” jetting can present itself in many different ways, so the variation between images of this “class” becomes troublesome for binary classification. Instead, autoencoders can be used for anomaly detection, where “desirable/consistent” jetting is the normal class, and “inconsistent/satellite” images would be anomalies. The autoencoder is trained on only consistent jetting images, compresses the image data into a latent representation, and then attempts to reconstruct the original image data using the latent representation as an input into a decoder. The decoder has trouble reconstructing the original image when given the latent representation of an “inconsistent/satellite” image, yielding a high reconstruction error. Jetting images that generate a reconstruction error higher than a specified threshold are deemed anomalies, and thus not “desirable” jetting.
Using Microseismicity to Map Cotton Valley Hydraulic Fractures

Spatial variations in event location and source parameters (magnitude, energy and stress release) for several thousand microseismic events recorded during six hydraulic fractures in May and July, 1997, within two deep gas wells in the Cotton Valley formation, are used to identify patterns in fracture growth and the dimensions of the fractures. The distributions of event locations suggest that all six hydraulic fracture were oriented at N78°E, in line with the major principal stress orientation in the field. Spatially, the microseismicity generally exhibited asymmetric behaviour with preferential growth to the east of the treatment wells (symmetry varying from 1:1 to 4.5:1). Only in two instances could the fracture be considered as symmetric, however, temporal growth patterns, as identified in the source parameter distribution were highly asymmetric. The fractures were constrained in depth to the perforation zones and varied in overall length from 1300 ft. to 2200 ft. Observed terminations in microseismic activity were considered to be related to crosscutting structures that altered or impeded fracture wing growth. Differences in apparent stress drop distributions suggested that these parameters can be used to outline differences in fracture behaviour and to define regions of the fracture where fracture growth does not necessarily contribute to the development of a propped zone. The results further suggest spatial variations in microseismicity, correlated with the treatment histories, can provide more information on the dynamics and heterogeneities associated with fracture growth.
Advanced Land Observing Satellite (ALOS): enabling technologies and platform performance

The Advanced Land Observing Satellite (ALOS) was launched on January 24, 2006. Since then, it has been operated successfully on orbit, delivering a variety of high-resolution images in numerous quantities and contributing to disaster management support many times. ALOS is a JAXA's flagship for high-resolution Earth observation. It is the Earth observation satellite that is capable of attaining conflicting goals: global data collection and high resolution (2.5m). To attain these goals, a variety of platform and mission technologies were developed. In particular, high-resolution optical sensor technology, phased-array synthetic aperture radar technology, precision attitude and position determination and control technology, and high-speed data handling technology were developed. This paper gives an overview of the ALOS mission and spacecraft with a particular emphasis on the critical platform and mission technologies. This also reviews the last 31 months' operations and on-orbit status of the ALOS spacecraft with the flight data analysis. The assessment and calibration of the mission-related platform performances such as orbit determination and control accuracies, attitude determination and control accuracies, attitude stability, and pixel geolocation determination accuracy are also reported along with our efforts to improve these performances.
Thermonuclear (Type I) X-Ray Bursts Observed by the Rossi X-Ray Timing Explorer

We have assembled a sample of 1187 thermonuclear (type I) X-ray bursts from observations of 48 accreting neutron stars by the Rossi X-ray Timing Explorer, spanning more than 10 years. The sample contains examples of two of the three theoretical ignition regimes (confirmed via comparisons with numerical models) and likely examples of the third. We present a detailed analysis of the variation of the burst profiles, energetics, recurrence times, presence of photospheric radius expansion, and presence of burst oscillations, as a function of accretion rate. We estimated the distance for 35 sources exhibiting radius-expansion bursts, and found that the peak flux of such bursts varies typically by 13%. We classified sources into two main groups based on the burst properties: (1) both long and short bursts (indicating mixed H/He accretion), and (2) consistently short bursts (primarily He accretion), and we calculated the mean burst rate as a function of accretion rate for the two groups. The decrease in burst rate observed at > 0. 06ṀEdd (≳2 × 1037 ergs s−1) is associated with a transition in the persistent spectral state and (as has been suggested previously) may be related to the increasing role of steady He burning. We found many examples of bursts with recurrence times <30 minutes, including burst triplets and even quadruplets. We describe the oscillation amplitudes for 13 of the 16 burst oscillation sources, as well as the stages and properties of the bursts in which the oscillations are detected. The burst properties are correlated with the burst oscillation frequency; sources spinning at <400 Hz generally have consistently short bursts, while the more rapidly spinning systems have both long and short bursts. This correlation suggests either that shear-mediated mixing dominates the burst properties, or alternatively that the nature of the mass donor (and hence the evolutionary history) has an influence on the long-term spin evolution.
Environmental Controls on Multiscale Spatial Patterns of Salt Marsh Vegetation

In coastal environments, biogeographic patterns are generally influenced by surface elevation and horizontal distance from sea water. However, it is still unclear whether these major topographic factors are significant controls of vegetation patterns across spatial scales at which different physical processes operate. This study investigated such a topography-vegetation relationship in a Danish salt marsh, focusing upon two scales: a macro-scale (ca. 500 m) across the marsh platform, encompassing seaward and landward areas, and a meso-scale (ca. 25 m) across tidal creeks. While long-term sea-level variation and grazing influenced the macro-scale pattern, short-term fluvial-geomorphic processes drove the meso-scale pattern. Despite these different underlying processes, similar floristic gradient structures between the two scales were identified by nonmetric multidimensional scaling. The gradient represented an ecological sequence from early to late succession, and strongly correlated with surface elevation. However, the gradient did not show any significant relationship with distance from shoreline or tidal channels. Our results suggest that, in salt marshes, elevation plays a still more important ecological role than the horizontal position relative to sea water at both macro- and meso-scales. The presence of one such fundamental component makes the system relatively simple, and will facilitate future scaling attempts.