Miracle-dz/UniFAR-FTUs huggingface dataset:
THE NATURE OF THE BRIGHT ULX X-2 IN NGC 3921: A CHANDRA POSITION AND HST CANDIDATE COUNTERPART

We report on Chandra observations of the bright ultraluminous X-ray (ULX) source in NGC 3921. Previous XMM-Newton observations reported in the literature show the presence of a bright ULX at a 0.5–10 keV luminosity of 2 × 1040 erg s−1. Our Chandra observation finds the source at a lower luminosity of ≈8 × 1039 erg s−1; furthermore, we provide a Chandra position of the ULX accurate to 0. ″7 at 90% confidence. The X-ray variability makes it unlikely that the high luminosity is caused by several separate X-ray sources. In three epochs of archival Hubble Space Telescope observations, we find a candidate counterpart to the ULX. There is direct evidence for variability between the two epochs of WFPC2 F814W observations with the observation obtained in 2000 showing a brighter source. Furthermore, converting the 1994 F336W and 2000 F300W WFPC2 and the 2010 F336W WFC3 observations to the Johnson U-band filter assuming a spectral type of O7I, we find evidence for a brightening of the U-band light in 2000. Using the higher resolution WFC3 observations, we resolve the candidate counterpart into two sources of similar color. We discuss the nature of the ULX and the probable association with the optical counterpart(s). Finally, we investigate a potential new explanation for some (bright) ULXs as the decaying stages of flares caused by the tidal disruption of a star by a recoiled supermassive black hole. However, we find that there should be at most only one of such systems within z = 0.08.
The REMO Ocean Data Assimilation System into HYCOM (RODAS_H): General Description and Preliminary Results

Abstract The first version of the Brazilian Oceanographic Modeling and Observation Network (REMO) ocean data assimilation system into the Hybrid Coordinate Ocean Model (HYCOM) (RODAS_H) has recently been constructed for research and operational purposes. The system is based on a multivariate Ensemble Optimal Interpolation (EnOI) scheme and considers the high frequency variability of the model error co-variance matrix. The EnOI can assimilate sea surface temperature (SST), satellite along-track and gridded sea level anomalies (SLA), and vertical profiles of temperature (T) and salinity (S) from Argo. The first observing system experiment was carried out over the Atlantic Ocean (78°S–50°N, 100°W–20°E) with HYCOM forced with atmospheric reanalysis from 1 January to 30 June 2010. Five integrations were performed, including the control run without assimilation. In the other four, different observations were assimilated: SST only (A_SST); Argo T-S profiles only (A_Argo); along-track SLA only (A_SLA); and all data employed in the previous runs (A_All). The A_SST, A_Argo, and A_SLA runs were very effective in improving the representation of the assimilated variables, but they had relatively little impact on the variables that were not assimilated. In particular, only the assimilation of S was able to reduce the deviation of S with respect to observations. Overall, the A_All run produced a good analysis by reducing the deviation of SST, T, and S with respect to the control run by 39%, 18%, and 30%, respectively, and by increasing the correlation of SLA by 81%.
Reciprocal Teaching and Comprehension of Struggling Readers

This preliminary study examined the effect of reciprocal teaching on struggling readers’ comprehension of a narrative text. The specific aspects studied were: (1) their suggestions to remake the ending of the narrative text based on preceding events; (2) their guided recall of details making up the gist of the narrative; and (3) their unguided recall of the gist of the narrative. The reciprocal teaching strategy was used to teach a literary text to 14 Malaysian struggling readers of English. The results showed that in the first lesson these students could not yet make links between the events of the story to suggest an alternative resolution of the narrative. Subsequently, their responses in the guided recall task showed that the four groups were able to supply the information making up gist of the story. However, the final unguided recall task showed that two groups usually provided their evaluation of their story and could remember only disparate details in the orientation of the story but could not recall major events. The findings suggest that a major challenge of implementing the reciprocal teaching strategy is guiding groups to share the task of monitoring their own comprehension through questioning, clarifying, summarizing and predicting.
An experience-sampling measure of job satisfaction and its relationships with affectivity, mood at work, job beliefs, and general job satisfaction

In this article, we proposed an experience-sampling method of measuring job satisfaction, assessed the contributions of average levels of mood at work and job beliefs to the prediction of job satisfaction, and examined the role of mood in mediating the relationship between affectivity and job satisfaction. The study involved a three-phase multisource longitudinal design that included experience-sampling surveys in the second phase of the study. Results suggested that average levels of experience-sampled job satisfaction indicate the general attitudinal construct of job satisfaction. As expected, pleasant mood at work and beliefs about the job made independent contributions to the prediction of job satisfaction (as measured with an overall evaluation and with an experience-sampling measure). In support of our mediation hypotheses, pleasant mood mediated the affectivity – job satisfaction relationship and the mediating effect was much stronger when job satisfaction was assessed with the experience-sampling method.
Classical hybrid Monte-Carlo simulations of the interconversion of hexabromocyclododecane

In this paper, we investigate the interconversion processes of the major flame retardant -- 1,2,5,6,9,10-hexabromocyclododecane (HBCD) -- by the means of statistical thermodynamics based on classical force-fields. Three ideas will be presented. First, the application of classical hybrid Monte-Carlo simulations for quantum mechanical processes will be justified. Second, the problem of insufficient convergence properties of hybrid Monte-Carlo methods for the generation of low temperature canonical ensembles will be solved by an interpolation approach. Furthermore, it will be shown how free energy differences can be used for a rate matrix computation. The results of our numerical simulations will be compared to experimental results.
Marine substrate response from the analysis of seismic attributes in CHIRP sub-bottom profiles

This paper presents an evaluation of the response of seismic reflection attributes in different types of marine substrate (rock, shallow gas, sediments) using seafloor samples for ground-truth statistical comparisons. The data analyzed include seismic reflection profiles collected using two CHIRP subbottom profilers (Edgetech Model 3100 SB-216S), with frequency ranging between 2 and 16 kHz, and a number (38) of sediment samples collected from the seafloor. The statistical method used to discriminate between different substratum responses was the non-parametric Kruskal-Wallis analysis, carried out in two steps: 1) comparison of Seismic Attributes between different marine substrates (unconsolidated sediments, rock and shallow gas); 2) comparison of Seismic Attributes between different sediment classes in seafloors characterized by unconsolidated sediments (subdivided according to sorting). These analyses suggest that amplitude-related attributes were effective in discriminating between sediment and gassy/rocky substratum, but did not differentiate between rocks and shallow gas. On the other hand, the Instantaneous Frequency attribute was effective in differentiating sediments, rocks and shallow gas, with sediment showing higher frequency range, rock an intermediate range, and shallow gas the lowest response. Regarding grain-size classes and sorting, statistical analysis discriminated between two distinct groups of samples, the SVFS (silt and very fine sand) and the SFMC (fine, medium and coarse sand) groups. Using a Spearman coefficient, it was found that the Instantaneous Amplitude was more efficient in distinguishing between the two groups. None of the attributes was able to distinguish between the closest grain size classes such as those of silt and very fine sand.
The Impact of Demand on Cargo Dwell Time in Ports in SSA

Long cargo dwell times in ports are a critical issue in Sub-Saharan African countries since they result in slow import processes and are bound to dramatically reduce trade. The main objective of this study is to analyze long dwell times' causes in ports in Sub-Saharan Africa from a shipper's perspective. The findings point to the crucial importance of private sector practices and incentives. The authors argue in the case of Sub-Saharan African countries that private operators, rather than being advocates of reforms in this area, might be responsible for the failures of many of these initiatives. It seems that in Sub-Saharan Africa importers' and freight forwarders' professionalism, cash constraints and operators' strategies are some of the factors that have a major impact on cargo dwell time. Low competency, cash constraints and low storage tariffs explain why most importers have little incentive to reduce cargo dwell time since in most cases, this would increase their input costs. However, monopolists/cartels may have a stronger incentive to reduce cargo dwell time but only in order to maximize their profit (and would not adjust prices downward).
Limited information-processing capacity and asymmetric stock correlations

Through an orthogonalized impulse-response analysis, I studied the relationship between the variance risk premium, market variance and stock correlations in the French stock market from September 2002 through September 2006, using high-frequency data-based measures. Variance risk premium is estimated using realized variances and index options-implied variances and used as a state vector to proxy investors perceived uncertainty. I found that a shock to variance risk premium causes long-lasting increases in the market variance pointing to the limitedness of investors information-processing capacity. At the same time, the shock generates consecutive increases in realized correlations between individual stocks and the market portfolio. I propose this as a possible explanation for the asymmetric/counter-cyclic behaviour of stock correlations.
Development of shoulders and plumes in the frame of the interchange instability mechanism for plasmapause formation

The mechanism of plasmapause formation based on interchange instability and a Kp‐dependent magnetospheric electric field model, enables us to determine the position of the plasmapause as a function of Kp and local time. We illustrate here how this physical mechanism is able to account for the formation of shoulders like those observed by EUV on IMAGE. A wide variety of other structures observed by IMAGE like tails (also called plumes), and notches are also obtained with this mechanism for the formation of a “knee” in the high altitude cross‐L distribution of the cold plasma density distribution.
Design of Testbed for Agile Computing of MapReduce Applications by using Docker

Cloud computing makes extensive use of virtual machines that permit for workloads, as well as resource usage, to be isolated from one another, and a hypervisor can be used by a virtual machine to construct cloud computing infrastructure. However, the hypervisor has high resource usage when constructing virtual machines, which results in a waste of allocated resources when not activated. Docker provides a more light-weight method to obtain agile computing resources based on a container technique that handles this problem. In this study, we have chosen this specific tool due to the increasing popularity of MapReduce and cloud container technologies such as Docker. This study aims to automatically configure Twister workloads for container-driven clouds. Basically, this is the first attempt towards automatic configuration of Twister jobs on a container-based cloud platform VM for many workloads.
UvA-DARE ( Digital Academic Repository ) Beyond diagnostic accuracy . Applying and extending methods for diagnostic test research

t Theree is ambiguity in the estimation of sensitivity and specificity in studies evaluatingg colonography in the screening for colon cancer . This ambiguity is due too conventional analysi s methods that do not take into account multiple findings thatt can be obtained by colonography as well as by colonoscopy , the reference standard. In this paper the pitfalls of some frequendy used methods will be discussed . Inn addition a new approach wil l be outlined that can be used to estimat e sensitivity andd specificity from such data. This method estimates the sensitivity and specificity, respectively,, as the probability of correctl y identifying true positive and true negative patients. Relative to other methods, this method takes all findings into account , includingg false positive and false negative lesions, as such no information is lost.
Determining the Core Radio Luminosity Function of Radio AGNs via Copula

The radio luminosity functions (RLFs) of active galactic nuclei (AGNs) are traditionally measured based on total emission, which does not reflect the current activity of the central black hole. The increasing interest in compact radio cores of AGNs motivates determination of the RLF based on core emission (i.e., core RLF). In this work we have established a large sample (totaling 1207) of radio-loud AGNs, mainly consisting of radio galaxies (RGs) and steep-spectrum radio quasars (SSRQs). Based on the sample, we explore the relationship between core luminosity (Lc) and total luminosity (Lt) via a powerful statistical tool called “Copula. ” The conditional probability distribution is obtained. We derive the core RLF as a convolution of with the total RLF that was determined by previous work. We relate the separate RG and SSRQ core RLFs via a relativistic beaming model and find that SSRQs have an average Lorentz factor of , and that most are seen within 8° ≲ θ ≲ 45° of the jet axis. Compared with the total RLF, which is mainly contributed by extended emission, the core RLF shows a very weak luminosity-dependent evolution, with the number density peaking around z ∼ 0.8 for all luminosities. Differences between core and total RLFs can be explained in a framework involving a combination of density and luminosity evolutions where the cores have significantly weaker luminosity evolution than the extended emission.
Nitrogen expander cycles for large capacity liquefaction of natural gas

Thermodynamic study is performed on nitrogen expander cycles for large capacity liquefaction of natural gas. In order to substantially increase the capacity, a Brayton refrigeration cycle with nitrogen expander was recently added to the cold end of the reputable propane pre-cooled mixed-refrigerant (C3-MR) process. Similar modifications with a nitrogen expander cycle are extensively investigated on a variety of cycle configurations. The existing and modified cycles are simulated with commercial process software (Aspen HYSYS) based on selected specifications. The results are compared in terms of thermodynamic efficiency, liquefaction capacity, and estimated size of heat exchangers. The combination of C3-MR with partial regeneration and pre-cooling of nitrogen expander cycle is recommended to have a great potential for high efficiency and large capacity.
Title State-ofthe art of freight forecast modeling : lessons learned and the road ahead Permalink

In this paper we review freight forecasting models and current advances and needs with respect to data and model development. We then present a case study to suggest which models should be developed for the State of California in the US. We suggest several alternatives including an aggregate commodity flow model, a disaggregate regional logistics model and a hybrid regional logistics model with a truck touring model. We point out however, that the data requirements for the latter model would be extensive. In addition, the development of hybrid models, for example progress in the integration of regional logistics models with urban truck touring models, will introduce new problems such as reconciling the outputs of multiple models for consistency.
System requirement specifications for a semantic knowledge management system for collaborative learning environment

In this study, a Semantic KMS Model is formulated to support collaborative learning environment based on ontology.A comprehensive review was conducted to identify the important components of existing models in Knowledge Management (KM), KMS and semantic areas, and a survey was conducted to finalize the important components of the proposed model.As a result, the proposed semantic KMS model consisted of six important components to support collaborative works; KM Processes, Ontology-based Knowledge Model, Semantic KM Features, Knowledge Quality, System Quality and KM Goals.A prototype, called Semantic KMS for Collaborative Learning was developed to illustrate how the model components are supporting KM processes in collaborative works based on the system requirement specifications described in this paper.The required modules of the semantic KMS are described in details and the ontology-based knowledge models are also presented.
Detection of gliclazide in aqueous samples using liquid chromatography/time-of-flight/mass spectrometry

The big challenge for the detection of pharmaceutical residues in water samples is the type of ionization mode in terms of positive or negative ionization which plays an important role to identify and quantify the analytes using liquid chromatography/mass spectrometry. An analytical method was applied to analysis of gliclazide (diabetic drug) in surface water and wastewater from sewage treatment plants and hospitals. The proposed analytical method allows simultaneous isolation and concentration procedure using solid phase extraction (Oasis HLB) prior to separation using high-performance liquid chromatography. The detection and confirmation was achieved by applying time-of-flight analyzer. The limits of quantification were as low as 1.4 ng/L (deionized water), 4 ng/L (surface water), 27 ng/L (hospital influent), 10 ng/L (hospital effluent), 6 ng/L (sewage treatment plant effluent) and 21 ng/L (sewage treatment plant influent), respectively. On average, good recoveries of higher than 87% were obtained for gliclazide in the studied samples. The proposed method successfully determined and quantified gliclazide in surface water and wastewater. The results showed that gliclazide is a persistent compound in sewage treatment effluents as well as in the recipient rivers. Gliclazide was detected in all samples and the highest concentration was 130 ng/L in influent of sewage treatment plant.
Remotely monitoring heart-rate and feeding behaviour of fish by using electronic sensor-tags

Modern electronic sensor tags (BioLoggers) can collect high resolution data on movement and physiology of fish. These tools make it possible to remotely monitor physiological stress responses as well as complex behaviours, such as feeding and hunting, in free swimming wild fish, data that often is difficult to collect by other means. Quantification of stress and feeding behaviour is valuable in behavioural ecology and fish conservation, and are also important in fish welfare (e.g. in hatchery environments and in fisheries). This study had two main goals: 1) Evaluating the use and function of a newly developed cordless heart rate bio-logger to measure stress in hatchery brown trout (Salmo trutta), and 2) Evaluating the use of a high resolution 3D accelerometer bio-logger to remotely capture different foraging behaviours in Eurasian perch (Perca fluviatilis). Bio-loggers are often inserted surgically in the fish, and in study 1 the first aim was to evaluate if the placement of the bio-logger inside the fish affects the quality of the data produced. Results showed that placement close to the heart produced significantly higher quality of data compared to when the logger was placed in the belly of the fish. The direction of the logger with regards to the electrodes did not impact the quality of the data. Based on this result, a protocol for the surgery and placement of cord-less HRT-sensors in trout was developed. To evaluate the ability of the bio-logger to capture change in heart rate as a function of stress, hatchery brown trout was tagged with heart rate sensors and exposed with a GABAergic anxiolytic drug known to reduce stress in fish. The fish was then exposed to handling stress, and heart rate in exposed fish was compared to control fish that was not exposed to the anxiolytic drug. The result showed that the control fish had significantly higher heart rate during handling periods compared to non-handling periods, but that such difference could not be seen in the drug exposed fish, hence indicating that the new cord-less heart rate logger is capable of quantifying induced stress and stress relief in fish. In study 2, two different feeding behaviours in perch, feeding on small insects and feeding on small fish, were carefully studied in aquaria. The two behaviours were then manually simulated using a euthanized perch tagged with 3D accelerometer bio-logger. The data collected by the accelerometer was then analyzed using a machine learning approach, with the aim to be able to distinguish between the two feeding behaviours using only the acceleration profiles. The result showed that it is possible to distinguish between feeding behaviours in perch with high accuracy (99 %) using acceleration bio-loggers. The results are discussed based on the potential usability of heart rate and accelerometer bio-loggers in animal welfare and ecological research.
Mapping the deep lithospheric structure beneath the eastern margin of the Tibetan Plateau from gravity anomalies

[1] Various authors have investigated the mechanism of lateral support of the lithosphere in maintaining the uplift of the Tibetan Plateau, based on gravity data and elastic flexural modeling, in the south of the plateau across the Himalayas and in the north and the northwest across the Altyn Tagh and West Kunlun Shan. However, the degree of the regional compensation and lateral support to the east of the Tibetan Plateau has remained unknown. In this paper we present a lithospheric flexure model by interpreting gravity and topography to understand the first-order problem of lateral support of the lithosphere at the eastern margins of the Tibetan Plateau. The flexural modeling constrains the geometry and strength variation of the lithosphere from the eastern margin of Tibet past the Longmen Shan ranges on to the Sichuan Basin. A lithosphere of intermediate strength (Te = 45 km) beneath the Sichuan Basin is weakened (Te = 36 km) by the thrusting underneath the eastern margin of the Tibetan Plateau. The strength variations indicate that about 10 km of the crustal material of the lithosphere has been ripped off and integrated into the thickened, upper crust of the Tibetan Plateau, which, however, has no appreciable strength. The stiffness of the lithosphere keeps the Tibetan Plateau relatively stable at its eastern margin and enables the weight of the plateau to be supported in the east by the Sichuan. Lithospheric deformation in the southern Longmen Shan area is more pronounced than in the northern region.
A New Design Approach for Speaker Recognition Using MFCC and VAD

This paper presents a new approach for designing a speaker recognition system based on mel frequency cepstral coefficients (MFCCs) and voice activity detector (VA D). VA D has been employed to suppress the background noise and distinguish between silence and voice activity. MFCCs were ext racted fro m the detected voice samp le and are co mpared with the database for recognition of the speaker. A new criteria for detection is proposed which gives very good performance in noisy environment.