Miracle-dz/UniFAR-FTUs huggingface dataset:
A Learned Query Rewrite System using Monte Carlo Tree Search

Query rewrite transforms a SQL query into an equivalent one but with higher performance. However, SQL rewrite is an NP-hard problem, and existing approaches adopt heuristics to rewrite the queries. These heuristics have two main limitations. First, the order of applying different rewrite rules significantly affects the query performance. However, the search space of all possible rewrite orders grows exponentially with the number of query operators and rules and it is rather hard to find the optimal rewrite order. Existing methods apply a pre-defined order to rewrite queries and will fall in a local optimum. Second, different rewrite rules have different benefits for different queries. Existing methods work on single plans but cannot effectively estimate the benefits of rewriting a query. To address these challenges, we propose a policy tree based query rewrite framework, where the root is the input query and each node is a rewritten query from its parent. We aim to explore the tree nodes in the policy tree to find the optimal rewrite query. We propose to use Monte Carlo Tree Search to explore the policy tree, which navigates the policy tree to efficiently get the optimal node. Moreover, we propose a learning-based model to estimate the expected performance improvement of each rewritten query, which guides the tree search more accurately. We also propose a parallel algorithm that can explore the tree search in parallel in order to improve the performance. Experimental results showed that our method significantly outperformed existing approaches.
Environmental regulations an option: Asymmetry effect of environmental regulations on carbon emissions using non-linear ARDL

ABSTRACT The current study reported the asymmetry effect of environmental regulations in the presence of controlled variables such as research and development spending, urban population growth, energy consumption, and financial development on carbon emissions in case of China for the period of 1991–2015. Econometric techniques such as ADF and PP is used to check the stationarity of the data while asymmetry or non-linear ARDL is used to check the asymmetry. The results suggest symmetric or linear relationship between environmental regulations and carbon emissions. Linear ARDL is applied to check long-run and short-run relationship amongst the variables. The results verified that there exists negative and statistically significant relationship exists both in short and long-run between environmental regulation and carbon emissions. Similarly, research and development and financial development also improve carbon emissions. However, urban population growth and energy consumption increase carbon emissions. The study further suggests that sustainable, green urbanization, green credit concept to promote sustainable financial development, innovation in technology through research and development and current environmental regulation should be strengthening to achieve China 2030 target of reducing carbon emissions.
Correlations between fracture width and Reynolds number of 3-D single fractures

This study shows a numerical simulation on the relationship between fracture width (W) and the Reynolds number (Re) for fractures having different joint roughness coefficients (JRCs). Numerical simulations by solving the Navier-Stokes (NS) equations are performed to model fluid flow through single fractures. The results show that the Re of the theoretical solutions of smooth models agrees well with those of numerical simulation results, indicating that the numerical code is reliable. As W increases from 5 mm to 200 mm, the Re increases significantly and then slightly. When the W is large, the change in Re gradually becomes smaller. This indicates that there is a critical W (W C), in which the influence of W on the Re is negligible when W exceeds the W C. When JRC is 0, 5.84 and 19.20, the corresponding W C is 27.38 mm, 26.55 mm and 24.63 mm, respectively.
Investigation on downhole gas-liquid two phase separation and mixing transportation characteristics with high gas fraction

Produced fluids in oilfields usually contains water, natural gas and other substances. With development of oilfields, formation energy decreases and oil reservoir degases, therefore high gas content wells increase. When the produced liquid is lifted by the Electric Submersible Pump (ESP), high gas content will impact pump working performance, and even leads to cavitation and gas lock, which greatly impact lifting efficiency and interrupt well production. To solve the problems caused by high gas content, this paper puts forward an idea of “separating - mixed transporting”, in which the separating is conducted by a flat deflector, and the mixed transporting is achieved by an ejector. According to this idea, an indoor experimental device and a numerical model were established. Laboratory experiments and numerical simulations were carried out simultaneously. The Euler-Euler multiphase flow model and Reynolds stress turbulence model (RSM) are used in the numerical simulation. It is found that a stable gas core formed by the guide vane appears near the swirl field center, and the gas core width decreases with the gas-liquid mixing flow rate increases. With the increase of inlet void fraction, the gas core width increases gradually. When the inlet gas fraction increases to 70%, the gas core can be taken out by the air pipe to achieve the purpose of complete separation. The distribution of the gas-liquid two-phase in the swirl field and the pressure drop during gas-liquid mixed transportation are compared and analyzed by numerical simulation and experimental testing, it is found that the numerical simulation results are in good agreement with the experimental results, which verifies the rationality of the selection of numerical simulation model. The research results are of great significance to broaden the application scope of ESP in high gas fraction oil wells.
Uncertainty elevation of landslide displacement prediction based on LSTM and Mixture Density Network

Considering monitoring noise and complexity of landslide movement, quantify the uncertainty of landslide displacement prediction is crucial and challenging. Traditional data-driven models such as long short-term memory networks (LSTM), support vector regression, and extrema learning machines, etc, give the predicted displacement without considering the uncertainty of the predictions. Moreover, the loss function of the data-driven model is mainly taken as mean square error, which may lead to a worse performance when the training data follows non-normal distribution and thus reduces the robustness of the model. This study tends to propose a novel hybrid model based on LSTM and mixture density network to quantify each data point’s probability density distribution. By introducing the mixture density network and the maximum likelihood loss function, this model can get rid of the limitation that the data needs to obey the normal distribution. The mixed probability density parameters of each data point were predicted accurately due to the dynamic learning process in time series by LSTM. Moreover, we introduce the ensemble prediction to consider the uncertainty of model parameters. The performance of the model was validated based on a typical landslide in the Three Gorges Reservoir Area (TGRA), the Baishuihe landslide. Application results demonstrate that the proposed model provides accurate mean predictions and reasonable confidence displacement intervals.
Probabilistic assessment of permanent displacement of soil slopes: how many ground motions are needed?

As the occurrence of earthquakes is highly uncertain, the permanent displacement of a slope during a given exposure time is also uncertain. Probabilistic analysis can be used to assess the effect of uncertainty in the ground motions on the permanent displacement. However, the number of ground motions to be considered in a probabilistic assessment of permanent displacement of a slope is still not clearly defined. In this paper, a numerical study is conducted to investigate the effect of number of ground motions on the variability of fragility curves and the hazard curve of the permanent displacement. It is found that for the slope study in this paper, the median fragility curve and hazard curve are not sensitive to the number of ground motions. The width of the confidence interval of the fragility curve can be reduced by half when the number of ground motions is increased by four times. It can be learned from the COV of the hazard curve of permanent displacement that the determination of the number of ground motion records should be based on a concerned critical permanent displacement.
Surface deformation monitoring of subway before and during construction based on PS-InSAR

The construction of urban subways induces ground surface deformation, and regional surface deformations harm subway construction. Measuring the surface deformation of the project area before and during construction is necessary. The construction of the Tianjin Metro Line 6 Lushuidao Station–Shuanggang Station section was used as the study case. A total of 6028 permanent scatterers (PSs) in 2.5 km2 of the project area were detected using persistent scatterer interferometric synthetic aperture radar (PS-InSAR). The distribution of PSs, the regional surface deformation rate around the station and along the tunnel, and the time-series deformation of individual PSs were analyzed. Results show that the PSs are mainly distributed on buildings. Few PSs are distributed on roads and natural ground surface, and almost no PSs are found on vegetation-covered and river areas. PS-InSAR deformation monitoring accuracy could achieve millimeter level. Moreover, the ground around Lushuidao Station is more stable than that around Shuanggang Station. Before the construction, the maximum settlement occurred on building 12 with a value of 13.98 mm, and the maximum lifting occurred on building 17 with a value of 15.85 mm. Finally, building 4 and ground on the east side adjacent to buildings 12 and 13 were affected by the construction of the pit. The PSs on them showed a significant settlement trend after the excavation.
Development of Flac3d software computing platform based on cloud computing technology

With the continuous improvement of the requirements for numerical simulation in engineering at home and abroad, the numerical simulation of geotechnical engineering has become more and more refined and complicated. Flac3d is one of the widely used numerical simulation software in the field of geotechnical engineering. In order to solve the problem that Flac3d is slow in calculation and occupies too much computing resources, the Flac3d software computing platform is developed based on the bottle framework and D3.js framework. The platform is fully functional and includes auxiliary modules such as billing module, file sharing module and security module. Users only need to input the computing resources and storage resources to automatically create a virtual server, and use the pre-installed Flac3d software in the server. The platform greatly reduces the computational time of the Flac3d, and the calculation rate is particularly improved under multiple operating conditions. Compared with general supercomputing centers, although the cloud computing platform is slightly weaker in hardware, its energy consumption is relatively low, and it is not limited by geographic location, and can form a larger scale.
Analysis on safe thickness of the horizontal separation pillar in the upward horizontal slicing and filling method

In the mines employing the upward horizontal slicing and filling mining method, it is necessary to set up a horizontal separation pillar in the middle transportation section. Too small a separation pillar may cause the roof to fall in the lower stope, damaging the transportation facilities in the middle section, and affecting the mining safety. Conversely, excessive thickness of the separation pillar will lead to the waste of mineral resources, reducing the economic benefits; therefore, the parameter optimization of horizontal separation pillar in the mining area remains a major safety and technical issue in upward horizontal slicing and filling mining. Taking the separation pillar in the middle section of an iron mine as the research object, various methods, including engineering analogy, theoretical calculation, and numerical simulation were used to comprehensively analyze the stability characteristics of the horizontal separation pillars with different thicknesses and determine the optimal thickness. For the stope with a span of 15–30 m mined with upward horizontal slicing and filling method in domestic and foreign mines, the thickness of horizontal separation pillar is 20–30 m, as analyzed using the engineering analogy method. Based on various theoretical formulas, such as the thickness-span ratio method, load transfer intersection line method, structural mechanics method, and others, the safety thickness of the separation pillar is calculated as 12–24 m with a safety factor of 1.50. According to a numerical calculation model established on the basis of measured drawings of stope and haulage roadways, the minimum safe thickness of the separation pillar is calculated as 23 m by the finite element analysis for typical sections. Based on the rock mass conditions and mining status of the iron mine, the thickness of horizontal separation pillar in the middle mining area is recommended to be no less than 23 m through a comprehensive analysis of empirical analogy, theoretical calculation, and simulation verification. The analysis results can provide a reference for the subsequent structural parameter adjustment and have a guiding significance for improving the comprehensive economic benefits of the mine.
Description of the biophysical characteristic and relation with discharge of Je’ne Rakikang Catchment Area

This study aims (1) to determine the biophysical characteristics and discharge on Je’ne Rakikang Catchment Area, (2) the relationship between the biophysical characteristics and discharge on Jene Rakikang Catchment Area. This research was conducted at Jene Rakikang Catchment Area. The data were collected in the form of primary and secondary data. Primary data were determined by measuring the discharge and precipitation, during 31 days of observation and secondary data collected from government agencies or related institutions such as land cover collected the data from the Institute for Balai Pemantapan Kawasan Hutan Wil. VII Makassar, rainfall data from the Global weather (2004-2013), geological data from Ujung Pandang GRDC Sheets of 1982, the data from Aster DEM slope, soil type data from RePP Prot 1987 and the data obtained from the calculation as well as visually. The data were analyzed using the quantitative descriptive method. The results showed that the dishcarge fluctuations of Je’ne Rakikang Catchment Area very varied. Biophysical characteristics of the Je’ne Rakikang Catchment Area consist of geology, topography, soil type, orientation, area, shape, draignase density, stream gradient, flow pattern, land cover and rainfall could potentially influence the behavior of discharge. The different of biophysical characteristics of Jene Rakikang Catchment Area provide a response to discharge in the event of rain with short time. ne Rakikang Catchment Area very varied. Biophysical characteristics of the Je’ne Rakikang Catchment Area consist of geology, topography, soil type, orientation, area, shape, draignase density, stream gradient, flow pattern, land cover and rainfall could potentially influence the behavior of discharge. The different of biophysical characteristics of Jene Rakikang Catchment Area provide a response to discharge in the event of rain with short time. ne Rakikang Catchment Area very varied. Biophysical characteristics of the Je’ne Rakikang Catchment Area consist of geology, topography, soil type, orientation, area, shape, draignase density, stream gradient, flow pattern, land cover and rainfall could potentially influence the behavior of discharge. The different of biophysical characteristics of Jene Rakikang Catchment Area provide a response to discharge in the event of rain with short time.
Corrigendum: Influence of carbon‐ion irradiation on the superconducting critical properties of MgB2 thin films (2019 Supercond. Sci. Technol. 32 025006)

We investigate the in ﬂ uence of carbon-ion irradiation on the superconducting ( SC ) critical properties of MgB 2 thin ﬁ lms. MgB 2 ﬁ lms of two thicknesses, 400 nm ( MB400nm ) and 800 nm ( MB800nm ) , were irradiated by 350 keV C ions having a wide range of ﬂ uence, 1  ×  10 13 – 1  ×  10 15 C atoms cm − 2 . The mean projected range ( R p ) of 350 keV C ions in MgB 2 is 560 nm, thus the energetic C ions will pass through the MB400nm, whereas the ions will remain into the MB800nm. The SC transition temperature ( T c ) , upper critical ﬁ eld ( H c2 ) , c -axis lattice parameter, and corrected residual resistivity ( ρ corr ) of both the ﬁ lms showed similar trends with the variation of ﬂ uence. However, a disparate behavior in the SC phase transition was observed in the MB800nm when the ﬂ uence was larger than 1  ×  10 14 C atoms cm − 2 because of the different T c s between the irradiated and non-irradiated parts of the ﬁ lm. Interestingly, the SC critical properties, such as T c , H c2 , and critical current density ( J c ) , of the irradiated MgB 2 ﬁ lms, as well as the lattice parameter, were almost restored to those in the pristine state after a thermal annealing procedure. These results demonstrate that the atomic lattice distortion induced by C-ion irradiation is the main reason for the change in the SC properties of MgB 2 ﬁ lms.
Revision 1-Word count : 7833 1 Jadeite and related species in shocked meteorites : Limitations on inference of 2 shock conditions 3

24 Jadeite is frequently reported in shocked meteorites, displaying a variety of textures 25 and grain sizes that suggest formation by either solid-state transformation or by 26 crystallization from a melt. Sometimes, jadeite has been identified solely on the basis 27 of Raman spectra. Here we argue that additional characterization is needed to 28 confidently identify jadeite and distinguish it from related species. Based on chemical 29 and spectral analysis of three new occurrences, complemented by first-principles 30 calculations, we show that related pyroxenes in the chemical space 31 (Na)(Al)(Si2)O6 – (Ca)(Al)(AlSi)O6 – (□)(Si)(Si2)O6 with up to 2.25 32 atoms Si per formula unit have spectral features similar to jadeite. However, their 33 distinct stability fields (if any) and synthesis pathways, considered together with 34 textural constraints, have different implications for precursor phases and estimates of 35 impactor size, encounter velocity, and crater diameter. A reassessment of reported 36 jadeite occurrences casts a new light on many previous conclusions about the shock 37 histories preserved in particular meteorites. 38
Facebook an Anti-Stereotyping Tool: A Case Study

Facebook, the most popular social media (SM) platform has penetrated every nook and corner of the world. SM is now treated as the ‘fifth Estate’, other than legislative, executive, judiciary, and mainstream media. The power of SM as a critique is widely acknowledged. Establishments are finding it difficult to deal with it at times. Due to its ease of usage and relative anonymity, the general public finds it very convenient to put across their viewpoints, even if it’s against the establishment. Some establishments at times are at loggerheads with champions of freedom of speech including civil rights activists. SM has been used for propaganda, marketing, and awareness campaigns. In this paper, we are proposing to use this powerful tool towards social change. Through a case study, a detailed process is being proposed for using social media particularly Facebook as an an-ti-stereotyping tool. The response to an online survey, the outcome of opinion min-ing, and the enthusiastic response to our case study by the targeted audience validate our hypothesis that Facebook can be effectively utilized as an anti-stereotyping tool.
New Hybrid Schemes for PAPR Reduction in OFDM Systems

The 3rd Generation Partnership Project (3GPP) introduced LTE to meet increasingly demands for communication services with high speed and quality. LTE uses OFDM in the form of OFDMA in the downlink and SCFDMA in the uplink combined with MIMO oﬀering high data rate, high capacity and immunity against multipath channels. However, still the high PAPR of the LTE transmitted signal is the major problem aﬀecting overall system performance degradation and power efficiency. A plenty of research has been devoted to reduce the performance degradation due to the PAPR problem inherent to LTE OFDM systems. A portion of the current techniques such companding methods have low-complexity, no constraint on modulation format and subcarrier size, good distortion and spectral properties; however, they have limited PAPR reduction capabilities. This paper proposes seven new hybrid schemes including Zaddoff Chu Matrix Transform (ZCT) precoding and six modern companding methods; Rooting Companding (RCT), New Error Function Companding (NERF), Absolute Exponential Companding (AEXP), Logarithmic Rooting Companding (LogR), Cosine Companding (COS) and Tangent Rooting Companding (TanhR) companding. Furthermore, the seventh proposed hybrid scheme has been added incorporating ZCT precoding with new proposed companding called Advanced AEXP (AAEXP) companding. The developed methods are combining properties of both ZCT & Compandings, and achieving superior PAPR performance and optimal BER. Simulations results illustrate that the new seven proposed hybrid schemes can achieve better PAPR reduction, and BER performance and the best achievement has been achieved by ZCT+AAEXP scheme.
Raman spectroscopy on biochar

Nanotechnologies for ICTs Department of Applied Science and Technology Raman Spectroscopy on Biochar by Jacopo ACQUAFRESCA Raman Spectroscopy is one the most used techniques to study materials and nanomaterials. After the technical improvement of the equipment used to perform the spectroscopy in the past thirty years, especially in terms of resolution and filter, it has estabilished as the principal instrument to evaluate and study carbons. The applications are very wide and with well known results, in particular for what concerns crystalline materials like diamond, graphene and grafite, for which is relatively easy to indentify properties and quality of different samples. The important knowledges learned in studying these materials had lead to shift the focus to more complex allotropes or coumponds, especially amorphous carbons and carbon nano-fibers. In this project, we studied a particular type of amorphous carbon: the Biochar. Biochar can be made in a lot of different ways, using different precursors (that are basically kind of woods) and differents amount of time and temperature during the process of pyrolysis. The purpose was to find some patterns in the spectra of this extremely disordered material and being able to relate them to different physical and chemical properties of different samples. The majority of work has being done almost entirely in Politecnico di Torino, only the production of the materials has been done almost entirely at the UK Biochar Research Centre. The process it was divided in some steps: first we perform spectroscopy to every samples to obtain the spectra. Then, using a Matlab program developed in Politecnico di Torino, we refined the spectra drawing the baseline, normalizing data between each other and fitting the results with a proper set of functions. Finally we confronted the signals finding some correspondance in terms of disorder, mostly due to the evolution of the state of the materials through different temperatures.