Miracle-dz/UniFAR-FTUs huggingface dataset:
Seismic versus sonic velocities; a vertical seismic profiling study

Vertical seismic profiling (VSP) techniques provide a method to measure accurately the seismic velocity and lithologic structure near the borehole. The analysis of a VSP survey can also provide insight into seismic‐wave propagation especially when related to sonic measurements. But VSP and sonic log velocities (or traveltimes) are often found to disagree. Recent field evidence of these differences suggests that the VSP traveltimes are delayed with respect to the integrated sonic times, especially in the deep section (>3000 ft), by about 2.0 ms/1000 ft on the average. The VSP has numerous applications in exploration geophysics, such as calibrating the sonic log. It is thus important to understand why the two measurements differ. Differences in the geometries, source frequencies, and instrumental errors of the two surveys are reviewed. More detailed analysis of seismic wave propagation in the VSP shows that short‐path multiples and velocity dispersion can have a significant delaying effect on the seismic tr.
Process modeling of controls on nitrogen trace gas emissions from soils worldwide

We report on an ecosystem modeling approach that integrates global satellite, climate, vegetation, and soil data sets to (1) examine conceptual controls on nitrogen trace gas (NO, N2O, and N2) emissions from soils and (2) identify weaknesses in our bases of knowledge and data for these fluxes. Nitrous and nitric oxide emissions from well-drained soils were estimated by using an expanded version of the Carnegie-Ames-Stanford (CASA) Biosphere model, a coupled ecosystem production and soil carbon-nitrogen model on a 1° global grid. We estimate monthly production of NO, N2O, and N2 based on predicted rates of gross N mineralization, together with an index of transient water-filled pore space in soils. Analyses of model performance along selected climate gradients support the hypothesis that low temperature restricts predicted N mineralization and trace gas emission rates in moist northern temperate and boreal forest ecosystems, whereas in tropical zones, seasonal patterns in N mineralization result in emission peaks for N2O that coincide with wetting and high soil moisture content. The model predicts the annual N2O:NO flux ratio at a mean value of 1.2 in wet tropical forests, decreasing to around 0.6 in the seasonally dry savannas. Global emission estimates at the soil surface are 6.1 Tg N and 9.7 Tg N yr−1 for N2O and NO, respectively. Tropical dry forests and savannas are identified by using this formulation as important source areas for nitrogen trace gas emissions. Because humans continue to alter these ecosystems extensively for agricultural uses, our results suggest that more study is needed in seasonally dry ecosystems of the tropics in order to understand the global impacts of land use change on soil sources for N2O and NO.
Distribution of nitrate in the water resources of Pakistan

Water quality monitoring activities have recognized the nitrate contamination in the drinking water sources as one of the major quality issue of Pakistan. Adopting a uniform sampling design, 747 samples were collected from a wide range of irrigated or non-irrigated regions having distribution of samples in sixteen cities as Lahore (79), Kasur (46), Faisalabad (30), Khushab (50), Chakwal (51), Mianwali (30), Jhelum (53), Bahawalpur (60), Karachi (60), Mirpur Khas (55), Peshawar (38), Risalpur (35), Quetta (81), Ziarat (21), Loralai (21), Mastung (37). The results showed that 19% of the total samples have nitrate concentration beyond the permissible safe limit of 10 mg/L falling in the concentration range of 11-160 mg/L of nitrate. The highest percentage contamination (23%) is found in water samples collected from both the Balochistan and Punjab provinces. Comparatively higher nitrate levels of <70 % in the groundwater sources like hand pumps and wells support the possibilities of increased contamination in the areas cultivated using heavy doses of fertilizers. Findings of the study provide support for further epidemiological investigations and potential strategy for mitigating the issue in the affected regions. Key words : Nitrate-N, groundwater contamination, hand pumps, methemoglobinemia, Pollution, nutrients, fertilizer, agriculture.
Misfit Criteria for Quantitative Comparison of Seismograms

We have developed and numerically tested quantitative misfit criteria for comparison of seismograms. The misfit criteria are based on the time-frequency representation of the seismograms obtained as the continuous wavelet transform with the analyzing Morlet wavelet. The misfit criteria include time-frequency envelope and phase misfits, time-dependent envelope and phase misfits, frequency-dependent envelope and phase misfits, and single-valued envelope and phase misfits. We tested properties of the misfit criteria using canonical signals. The canonical signals, taken as the reference signals, were specifically amplitude, phase shift, time shift, and frequency modified to demonstrate the ability of the misfit criteria to prop- erly quantify the misfits and recognize the character and cause of the misfits between the reference and modified signals. In all cases the misfit criteria properly quantified and characterized the misfits. The misfit criteria were also calculated for four different numerical solutions for a single layer over half-space (the SCEC LOH.3 problem) and the reference FK so- lution. The misfit criteria provided useful insight into the misfits between individual numerical solutions and the reference solution. The standard RMS misfit matches the single-valued envelope misfit only in the case of a pure amplitude modification of the signal. In all other cases RMS consid- erably overestimates the misfits and does not characterize them.
Contrasting climate change in the two polar regions

The two polar regions have experienced remarkably different climatic changes in recent decades. The Arctic has seen a marked reduction in sea-ice extent throughout the year, with a peak during the autumn. A new record minimum extent occurred in 2007, which was 40% below the long-term climatological mean. In contrast, the extent of Antarctic sea ice has increased, with the greatest growth being in the autumn. There has been a large-scale warming across much of the Arctic, with a resultant loss of permafrost and a reduction in snow cover. The bulk of the Antarctic has experienced little change in surface temperature over the last 50 years, although a slight cooling has been evident around the coast of East Antarctica since about 1980, and recent research has pointed to a warming across West Antarctica. The exception is the Antarctic Peninsula, where there has been a winter (summer) season warming on the western (eastern) side. Many of the different changes observed between the two polar regions can be attributed to topographic factors and land/sea distribution. The location of the Arctic Ocean at high latitude, with the consequently high level of solar radiation received in summer, allows the icealbedo feedback mechanism to operate effectively. The Antarctic ozone hole has had a profound effect on the circulations of the high latitude ocean and atmosphere, isolating the continent and increasing the westerly winds over the Southern Ocean, especially during the summer and winter
A seismic and gravity study of the McGregor geothermal system, southern New Mexico

Seismic and gravity studies have proven to be valuable tools in evaluating the geologic setting and economic potential of the McGregor geothermal system of southern New Mexico. An initial gravity study of the system demonstrated that a gravity high coincides with the heat‐flow high. A subsequent seismic reflection survey images a strong reflector, interpreted to be associated with a bedrock high that underlies the gravity and heat‐flow highs. A single reflection, which coincides with the water table, occurs within the Tertiary basin fill above bedrock. This reflector is subhorizontal except above structurally high bedrock, where it dips downward. This observation is consistent with well data that indicate a bedrock water table 30 m lower than water in the basin‐fill aquifer. Velocity models derived from seismic tomography show that the basin fill has velocities in the range of 800 to 4000 m/s and that the bedrock reflector coincides with high velocities of 5000 to 6000 m/s. Low‐velocity zones within the b.
Quaternion‐based visual servo control in the presence of camera calibration error

Visual servo control systems use information from images along with knowledge of the optic parameters (i.e. camera calibration) to position the camera relative to some viewed object. If there are inaccuracies in the camera calibration, then performance degradation and potentially unpredictable response from the visual servo control system may occur. Motivated by the desire to incorporate robustness to the camera calibration, different control methods have been developed. Previous adaptive/robust controllers (especially for six degree‐of‐freedom camera motion) rely heavily on properties of the rotation parameterization to formulate state estimates and a measurable closed‐loop error system. All of these results are based on the singular axis–angle parameterization. Motivated by the desire to express the rotation by a non‐singular parameterization, efforts in this paper address the question: Can state estimates and a measurable closed‐loop error system be crafted in terms of the quaternion parameterization when the camera calibration parameters are unknown? To answer this question, a contribution of this paper is the development of a robust controller and closed‐loop error system based on a new quaternion‐based estimate of the rotation error. A Lyapunov‐based analysis is provided which indicates that the controller yields asymptotic regulation of the rotation and translation error signals given a sufficient approximate of the camera calibration parameters. Simulation results are provided that illustrate the performance of the controller for a range of calibration uncertainty. Copyright © 2009 John Wiley & Sons, Ltd.
Reply to comment on Cao W, Bowden BW, Davie T, Fenemor A. 2006. ‘Multi‐variable and multi‐site calibration and validation of SWAT in a large mountainous catchment with high spatial variability’. Hydrological Processes 20(5):1057‐1073

Cao et al. (2006) proposed an approach to calibrating internal state variables, such as evapotranspiration and baseflow (multi-variables) and conducting the calibration in several sub-catchments (multi-sites), which was integrated into a model calibration and validation process. The method used field measurements from various time scales in different catchments for model calibration and validation, which has been suggested as an effective methodology for reducing uncertainty in parameter identification for physically based, distributed hydrological models (Fenemor, 1988; Grayson et al., 1992; Anderton et al., 2002; Bergstrom et al., 2002), particularly in a large catchment with much heterogeneity and high spatial variability. Recently, Beven (2006) comprehensively reviewed model equifinality issues and pointed out that a variety of factors may be responsible for the model errors when comparing measured streamflow data with simulations. These include model parameterization uncertainty (spatial variability in climate, soil and land use), flow measuring uncertainty, errors due to sampling strategies, errors or oversimplifications inherent in the model structure, and others (Refsgaard and Storm, 1996; Beven, 2006). Cao et al. (2006) used a range of possible approaches to reduce the uncertainty including: improving the accuracy and spatial representation of the precipitation input by using a separate preprocessing model based on a long rainfall gauging history and local expertise; increasing the accuracy and spatial representativity of air temperature based on the published local lapse rate; adjusting the
The Shimer Puzzle and the Identification of Productivity Shocks

Shimer (2005) argues that the Mortensen-Pissarides (MP) model of unemployment lacks an amplification mechanism because it generates less than 10 percent of the observed business cycle fluctuations in unemployment given labor productivity shocks of plausible magnitude. This paper argues that part of the problem lies with the identification of productivity shocks. Because of the endogeneity of measured labor productivity, filtering out the trend component as in Shimer (2005) may not correctly identify the shocks driving unemployment. Using a New-Keynesian framework to control for the endogeneity of productivity, this paper estimates that the MP model can account for a third, and possibly as much as 60 percent, of fluctuations in labor market variables.
Using scaling for macroweather forecasting including the pause

The ScaLIng Macroweather model (SLIMM) is a new class of stochastic atmospheric model. It exploits the large system memory to overcome the biases of conventional numerical climate models, it makes hindcasts and forecasts over macroweather forecast horizons (≈10 days to decades). Using the simplest (scalar), SLIMM model with only two parameters, we present various twentieth century hindcasts including several of the slowdown (“pause”) in the warming since 1998. The 1999–2013 hindcast is accurate to within ±0.11 K, with all the 2002–2013 anomalies hindcast to within ±0.02 K. In comparison, the Climate Model Intercomparison Project Phase 3 hindcasts were on average about 0.2 K too warm.
I Know Your Family: A Hybrid Information Retrieval Approach to Extract Family Information from Microblogs

With the growing popularity of social networks, large amounts of personal information have been made available over the Internet. The aim of this thesis is to identify the family related information of a person from their microblogs (Twitter). We use their personal details, tweets and their friends’ details in order to achieve this. Since, we deal with the modern world short text data; we have used a hybrid information retrieval methodology taking into account the Parts of Speech of the data, Phrase Similarity and the Semantic Similarity of the data along with the openly available twitter data. The future use of this research is to develop a Client Side protection tool that will help users validate the data to be posted for privacy breech.
Sensitivity of stream temperatures in the United States to air temperatures projected under a global warming scenario

To project mean weekly stream temperature changes in response to global climate warming and for studies of freshwater ecosystems, a four‐parameter nonlinear function of weekly air temperatures was used. One parameter, the upper bound stream temperature, was obtained by extreme value analysis from stream temperature data, and the other three parameters were obtained by least squares regression analysis. The least squares regression function was developed separately for the warming season and the cooling season (hysteresis) to take heat storage due to snowmelt or reservoir operations into account. There were very weak correlations between model parameters and annual or seasonal air temperatures. To project weekly stream temperatures under a 2 × CO2 climate scenario, weekly air temperature data from 166 weather stations, incremented by the output of the Canadian Center of Climate Modelling (CCC) general circulation model (GCM), were applied to nonlinear stream temperature models developed for 803 stream gaging stations. An error analysis indicated that only 39 stream gaging stations would not exhibit a significant change under the CCC‐GCM 2 × CO2 climate scenario. The projections at the remaining 764 stream gaging stations showed that mean annual stream temperatures in the contiguous United States would increase by 2°–5°C, least near the West Coast and most in the Missouri River and Ohio River basins. On average, there would be a 1°–3°C increase in the maximum and minimum weekly stream temperatures under the 2 × CO2 climate scenario, most in the central United States. It was also found that most streams would experience the maximum change in weekly stream temperatures in spring (March–June). The minimum changes in stream temperatures are projected to occur in winter (December and January) and summer (July and August) throughout the United States.
Calibrating an Electromagnetic Induction Instrument to Measure Salinity in Soil under Irrigated Cotton

Various calibration approaches have been proposed for determining profiles of apparent soil electrical conductivity (EC a ) or soil electrical conductivity of a saturated soil paste extract (EC e ) using an EM38 instrument. One of the most promising of these, the established-coefficients approach, was selected for calibration of the EM38 to some irrigated cotton (Gossypium hirsutum L.)-growing soil located in the Edgeroi district of the lower Namoi valley, northern NSW, Australia. However, the fitted salinity profiles were locally erratic, although global trends could be recognized. This method was compared with simple linear regression applied to the data from each depth increment separately. This was also unsatisfactory, and in fact, was not obviously different from the established-coefficients method on the data. An alternative and statistically more rigorous approach was used in which a logistic curve is fitted to each calibration hole (the logistic profile model). This mixed random and fixed effects nonlinear model predicts EC e from measurements generated by an electromagnetic (EM) instrument (EM38) held in the horizontal mode of operation EM 0,H . The logistic profile model fitted the data well, with no obvious patterns in the residuals, and depended on far fewer parameters than the two alternative methods. In addition, unlike the established-coefficients approach, the logistic model provided meaningful prediction errors.
Sedimentological and geomorphological impacts of the jökulhlaup (glacial outburst flood) in january 2002 at kverkfjöll, northern iceland

Abstract Jökulhlaups (glacial outburst floods) are common hazards in many glaciated environments. However, research on the controls on the sedimentological and geomorphological impact of jökulhlaups is rare. Developing a more comprehensive understanding of flood impacts may be useful for hazard identification, prediction and mitigation. This study determines the controls on the sedimentological and geomorphological impact of a jökulhlaup in January 2002 at Kverkfjöll, northern Iceland. This jökulhlaup, caused by geothermal activity, reached a peak discharge of 490 m3s−1 as recorded at a permanent gauging station 40 km downstream from the glacier snout. However, reconstructed peak discharges in the proximal part of the jökulhlaup channel near the glacier snout indicate a peak discharge of 2590 m3s−1. The jökulhlaup hydrograph was characterized by a rapid rising stage and a more gradual falling stage. As a result, sedimentary and geomorphological impacts included poorly sorted, structureless, matrix‐supported deposits; massive sand units; clast‐supported units; ice‐proximal cobbles, rip‐up clasts and kettle‐holes; and steep‐sided kettle‐holes. These features are proposed to be characteristic of rapid rising stage deposition. Additionally, large‐scale gravel bars and bedload sheets prograded and migrated during the rapid rising stage. The development of these bedforms was facilitated by high bedload transport rates, due to high discharge acceleration rates during the rapid rising stage. During the more prolonged falling stage, there was sufficient time for sediment incision and erosion to occur, exhuming cobbles, ice blocks and rip‐up clasts, and creating well‐defined terrace surfaces. This study provides a clearer understanding of hydrological and sedimentological processes and mechanisms operating during jökulhlaups, and helps to identify flood hazards more accurately, which is fundamental for hazard management and minimizing risk.
An interface of drainage division for modeling wetlands and riparian buffers in agricultural watersheds

In a complex watershed, isolated wetlands, riparian wetlands and riparian buffers provide important functions such as flood attenuation and water quality improvement. For conservation purposes, it is critical to properly delineate drainage areas for these features such that their impacts on runoff, sediment and pollutant transport can be reasonably simulated. However, traditional methods for watershed delineation typically fill depressions or ignore riparian features in order to maintain the continuity of surface flow pattern. In this study we develop an ArcView geographic information system (GIS) interface for watershed delineation that accounts for wetlands and riparian buffers. Based on digital elevation model (DEM), wetland distribution, and stream network GIS data, a subwatershed is further divided into isolated wetland drainage, concentrated flow drainage, riparian wetland drainage, and direct stream drainage. Outflow from isolated wetlands forms a source of concentrated flow that may contribute to riparian wetlands or bypass riparian buffers depending on its outlet location. This approach of drainage division makes a contribution in linking watershed models and field-based models through divided drainage areas. The developed interface provides a tool for simulating hydrologic processes of these features and assessing different restoration scenarios. The drainage division interface is applied to the Fairchild Creek watershed of southern Ontario in Canada where numerous isolated wetlands, riparian wetlands and riparian buffers exist. A comparison of runoff and sediment simulation results before and after drainage delineation shows the importance of the interface in facilitating watershed modeling.
Posttraumatic stress disorder according to DSM-5 and DSM-IV diagnostic criteria: a comparison in a sample of Congolese ex-combatants

Background Compared to DSM-IV, the criteria for diagnosing posttraumatic stress disorder (PTSD) have been modified in DSM-5. Objective The first aim of this study was to examine how these modifications impact rates of PTSD in a sample of Congolese ex-combatants. The second goal of this study was to investigate whether PTSD symptoms were associated with perpetrator-related acts or victim-related traumatic events. Method Ninety-five male ex-combatants in the eastern Democratic Republic of Congo were interviewed. Both the DSM-IV and the DSM-5 PTSD symptom criteria were assessed. Results The DSM-5 symptom criteria yielded a PTSD rate of 50% (n=47), whereas the DSM-IV symptom criteria were met by 44% (n=42). If the DSM-5 would be set as the current “gold standard,” then DSM-IV would have produced more false negatives (8%) than false positives (3%). A minority of participants (19%, n=18) indicated an event during which they were involved as a perpetrator as their most stressful event. Results of a regression analysis (R 2=0.40) showed that, after accounting for the number of types of traumatic events, perpetrated violent acts were not associated with the symptom severity of PTSD. Conclusions The findings demonstrate that more diagnostic cases were produced with the DSM-5 diagnostic rules than were dropped resulting in an increase in PTSD rates compared to the DSM-IV system. The missing association between PTSD symptoms and perpetrated violent acts might be explained by a potential fascinating and excited perception of these acts.