Auxiliary Parameters Research Articles

Influence of auxiliary geometric parameters on discharge capacity of piano key weirs

A piano key weir (PKW) is a new type of labyrinth weir that has the advantages of a high discharge capacity, little affected by terrain restrictions, cost-effectiveness, and wide applicability. It is an efficient type of spillway from the hydraulic and economic viewpoints. To elucidate the effects of the auxiliary geometrical parameters of the PKW, i.e., the nose and the parapet walls, on the discharge capacity, six different PKW models were tested in a rectangular tempered glass flume with a length of 16 m, a width of 0.5 m, and a depth of 0.75 m. The experimental results indicated that adding a triangular or rounded nose improved the flow patterns, and increased the discharge capacity of the PKW by up to 8.5% with a relative water head of 0.188. Furthermore, the addition of a parapet wall improved the discharge capacity of the PKW, and a higher parapet wall yielded a higher discharge efficiency. When the nose form and the height of the parapet wall were optimized comprehensively, the total discharge of the PKW was increased by up to 16.8%. The study reveals the influence mechanism of the nose form and the parapet wall on the discharge efficiency of the PKW and provides a reference for the geometric design and engineering application of the PKW.

Generalised regression estimation via the bootstrap

SummaryA generalised regression estimation procedure is proposed that can lead to much improved estimation of population characteristics, such as quantiles, variances and coefficients of variation. The method involves conditioning on the discrepancy between an estimate of an auxiliary parameter and its known population value. The key distributional assumption is joint asymptotic normality of the estimates of the target and auxiliary parameters. This assumption implies that the relationship between the estimated target and the estimated auxiliary parameters is approximately linear with coefficients determined by their asymptotic covariance matrix. The main contribution of this paper is the use of the bootstrap to estimate these coefficients, which avoids the need for parametric distributional assumptions. First‐order correct conditional confidence intervals based on asymptotic normality can be improved upon using quantiles of a conditional double bootstrap approximation to the distribution of the studentised target parameter estimate.

QuiltEdge: Novel geostatistical workflow for heterogeneous reservoirs with an innovative combination of multi-variable image quilting and edge property concept to model heterogeneity and flow barriers

Detailed and accurate techniques which plays a vital role in providing more reliable predictions of reservoir performance are needed for spatial modeling of reservoirs with complex heterogeneity. Additional auxiliary parameters are usually defined to emulate the reservoir complex geometry and high degree of heterogeneity. Edge property concept can be used to model the effect of large-scale flow barriers or highly conductive channels such as sealing or conductive fault planes. In this study, the edge properties are overlaid on a grid of extremely heterogeneous permeability to examine the predictability of the reservoir model. Image quilting is applied to simultaneously build the cell-wise and edge properties of the reservoir model. Image quilting in this study utilizes a multivariable approach for simultaneous cell-wise and edge property modeling. Our proposed approach has been successfully examined on modified SPE 10 benchmark model, where the permeability spatial variation was modified and edge properties were added to represent the large-scale sealing or conductive faults. Several realizations were generated using image quilting technique based on training images. The geological patterns of permeability variation and the large scale barriers or conduits are conveyed properly from training images into reservoir model, even in this extremely heterogeneous studied reservoir. The difference of gas breakthrough time between inferred value of model realizations and the reference model is almost 12 days for minor modifications of famous SPE10 benchmark. Moreover, maximum oil production rate is predicted with more reliability as a consequence of proposed approach. The slope of oil production rate is identical to the reference case for the times after breakthrough. In addition, breakthrough time is estimated efficiently. With this approach (derived from permeability texture concept), the modelled properties become more and more realistic (geologically-consistent realizations) and the reservoir simulation outputs are become more reliable. This approach constrains the variability of geological properties and consequently the uncertainty with reservoir forecast is substantially reduced.

Groundwater vulnerability and trace element dispersion in the Quaternary aquifers along middle Upper Egypt.

Association of trace metal concentrations in water is problematic; however, its information is scarce and sometimes contradicted. This work presents variations in dissolved major constituents and trace element concentrations along the quaternary aquifers located in middle Upper Egypt (Minia and Assiut governorates). A total of 205 groundwater samples from these aquifers were collected. Auxiliary parameters (pH, alkalinity, and conductivity), major cations (Ca2+, Mg2+, Na+, and K+), dominant anions (HCO3-, SO42-, Cl-, and NO3-), and trace element (B, Fe, Cu, Mn, Ni, Pb, Cd, and Cr) concentrations were measured in all samples. Univariate (correlation coefficient and scatter matrix) analysis was employed combined with multivariate (principal coordinates analysis) analysis to identify the chemical characteristics of groundwater that are responsible for generating most of the variability within the dataset. Also, hierarchical cluster analysis was applied to classify the geochemical origin of the groundwater constituents. The results indicate that the groundwater pollution is mainly due to water-rock interactions, including aquifer matrix dissolution, redox reaction of trace metals, input from wastewater, and agricultural fertilizers.

Summer maize growth under different precipitation years in the Huang-Huai-Hai Plain of China

Maize (Zea mays L.) is one of the important crops for meeting the high food demand for both humans and animals in the world. Promptly monitoring and accurately assessing growth of summer maize, a major crop in the Huang-Huai-Hai Plain (the HHH Plain) in China, is regularly conducted for estimating national yield and assessing food security. In this study, the process-based Remote-Sensing-Photosynthesis-Yield Estimation for Crops (RS-P-YEC) model, driven by remote sensing products, meteorological observations, phenophases of summer maize, and some auxiliary parameters, was used to simulate daily net primary productivity (NPP) of summer maize in the HHH Plain from June to September in 2000–2017. Summer maize growth at the county scale level (characterized by NPP) under different precipitation years was evaluated along West-East, North-South, and Northwest-Southeast transects in the HHH Plain. Results showed that with increasing accumulative precipitation during the summer maize growing season, maize growth exhibited the characteristics of a downward opening parabolic curve for a dataset including all site-years and for single year datasets. The best simulated maize growth and actual observed yield generally occurred when accumulative precipitation during the summer maize growing season was between 300 and 500 mm. Furthermore, summer maize growth was reduced in years with growing season accumulative precipitation less than 300 mm or greater than 500 mm as seen in the analysis of data from several stations under different precipitation levels along the three transects. This study confirmed that NPP simulated with the RS-P-YEC model, driven by remote sensing products and ground-based meteorological observations, is a good indicator for monitoring and evaluating summer maize growth under different precipitation levels in the HHH Plain. As such, the evaluation results will be helpful for forecasting yield across broad geographical areas, and for assessing national food security.

Effect of auxiliary gas flow parameters on microstructure and properties of Mo coatings prepared by high-energy plasma spraying

Based on the high-power and high-flow mode of the three-cathode high-energy plasma spray system, Mo coatings were prepared on the surface of 15-5PH steel, and the effects of different auxiliary gas (helium) flow parameters on the micro-morphology and properties of the coating were studied. X-ray diffraction (XRD), scanning electron microscope (SEM), micro-hardness tester, universal testing machine, and friction and wear testing machine were used to characterize the phase composition, micro-morphology, micro-hardness, combining strength and tribological properties of the coating. The results showed that the surface of the Mo coating prepared by high-energy plasma spraying had visible pit shapes. The coating porosity gradually decreased along with the thickness of the coating, showing a typical tamping morphology. Due to the breakneck flying speed and deposition speed of powder particles, no apparent oxidation phenomenon was observed in the coating. With the increase of auxiliary gas flow, the tamping effect of the powder particles on the coating increased, and the density, hardness, and bonding strength of the coating increased. With the increase of auxiliary gas flow, the wear rate of the coating decreased, and the wear mechanism of the coating gradually changed from abrasive wear to adhesive wear.

Analytical Comparison Between the Information Gain and Gini Index using Historical Geographical Data

The historical geographical data of Kashmir province is spread across two disparate files having attributes of Maximum Temperature, Minimum Temperature, Humidity measured at 12 A.M., Humidity measured at 3 P.M., rainfall besides auxiliary parameters like date, year etc. The parameters Maximum Temperature, Minimum Temperature, Humidity measured at 12 A.M., Humidity measured at 3 P.M. are continuous in nature and here, in this study, we applied Information Gain and Gini Index on these attributes to convert continuous data into discrete values, their after we compare and evaluate the generated results. Of the four attributes, two have same results for Information Gain and Gini Index; one attribute has overlapping results while as only one attribute has conflicting results for Information Gain and Gini Index. Subsequently, continuous valued attributes are converted into discrete values using Gini index. Irrelevant attributes are not considered and auxiliary attributes are labeled accordingly. Consequently, the data set is ready for the application of machine learning (decision tree) algorithms.

Linear Parameter-Varying Embedding of Nonlinear Models with Reduced Conservativeness

In this paper, a systematic approach is developed to embed the dynamical description of a nonlinear system into a linear parameter-varying (LPV) system representation. Initially, the nonlinear functions in the model representation are approximated using multivariate polynomial regression. Taking into account the residuals of the approximation as the potential scheduling parameters, a principle component analysis (PCA) is conducted to introduce a limited set of auxiliary scheduling parameters in coping with the trade-off between model accuracy and complexity. In this way, LPV embedding of the nonlinear systems and scheduling variable selection are jointly performed such that a good trade-off between complexity and conservativeness can be found. The developed LPV model depends polynomially on some of the state variables and affinely on the introduced auxiliary scheduling variables, which all together comprise the overall scheduling vector. The methodology is applied to a two-degree of freedom (2-DOf) robotic manipulator in addition to an academic example to reveal the effectiveness of the proposed method and to show the merits of the presented approach compared with some available results in the literature.

Parametric Simulation Analysis of the Electromagnetic Force Distribution and Formability of Tube Electromagnetic Bulging Based on Auxiliary Coil

Tube electromagnetic bulging has been given much attention due to its superior advantages in the field of light alloy processing. However, the conventional tube electromagnetic bulging process exhibits some critical issues that restrict its wide industrial applications. This includes non-uniform axial deformation and poor forming performance such as wall thickness thinning. This article proposes a cost-effective solution for such issues through simultaneous radial and axial electromagnetic force loading using an auxiliary driving coil. In this regard, the influence of the auxiliary coil geometrical parameters on the electromagnetic force distribution and tube forming performance is investigated using electromagnetic-structure coupling model of the bulging process. The robustness of the new proposed method is validated by comparing its electromagnetic force distribution and tube forming performance with the traditional cylindrical coil method, currently used by industry practice. Numerical results show that the introduction of the auxiliary coil may effectively weaken the radial electromagnetic force at the end of the tube and solve the uneven axial deformation issue. Based on the obtained results, the maximum uniform deformation area is increased from 6.9mm to 35.1mm. The tube relative wall thinning issue is reduced and the relative wall thickness reduction of the pipe is found to be 0.01661. The axial electromagnetic force can be further improved by adjusting the geometrical parameters of the coil and the proposed electromagnetic bulging can effectively increase the uniform deformation range of the tube.

A Hybrid Localization Algorithm Based on Doppler Shift and AOA for an Underwater Mobile Node

To solve the problem of low accuracy of a mobile node localization in an underwater sensor network, this article proposes a hybrid localization algorithm based on Doppler shift and angle of arrival (AOA) for the underwater mobile node (DAHL). This algorithm utilizes the Doppler frequency shift between the different signals received from the anchor node and the mobile node and the AOA measurement of the signal reflected by the mobile node to estimate the instantaneous position and velocity information of the mobile node through a two-stage algebraic method. In view of the existing measurement errors in the actual situation, the position and velocity estimation errors of the mobile node are optimized by introducing auxiliary parameters. Theoretical analysis and simulation experiments show that the DAHL method can effectively improve the localization accuracy of the mobile node. The localization accuracy of this algorithm can be close to the Cramér-Rao Lower Bound (CRLB) with the condition of small measurement errors.

Structural, magnetic and Mössbauer analysis of lanthanum and nickel doped Co2Y-type hexaferrite nanomaterial matrix synthesized by sol-gel auto-combustion technique

Sol-gel auto-combustion technique was used to prepare the lanthanum (La3+) and nickel (Ni2+) doped Co2Y-type Sr2-yLayCo2NixFe12-xO22; x = 0.0, 0.1, 0.2, 0.3; y = 0.0, 0.01, 0.02, 0.03 nanohexaferrites materials. Synthesized nanohexaferrites were characterized by XRD, FTIR and EDS analysis. The collective XRD analysis reveals the single-phase patterns corresponding to various dopants concentration in the powder system matrix. The calculated structural - auxiliary parameters viz. Lattice constants (a and c), cell volume (Vcell), X-ray density (dx), bulk density (db) and porosity (P) have been found in range; a = 5.8798–5.8321 Å, c = 43.7316–44.7214 Å, Vcell = 1309.303–1317.304 Å3, dx = 5.014–4.987 gm/cm3, db = 3.774–3.128 gm/cm3 and P = 0.247–0.37. The XRD results were supported by FESEM and TEM images, which showed the plate-like shape of particles. Unlike irregular grains, regular platelet-like grains were composed of several crystallites with almost parallel c-axis and this is the most suitable shape for microwave absorption. Fourier-transform infrared spectroscopy (FTIR) showed the location of the ions including their respective bonds within the structure of the lattice matrix and variation of ion concentration was depicted by EDS analysis of the powder matrix. The investigation of magnetic properties was done by vibrating sample magnetometer (VSM). The saturation magnetization (Ms) and coercivity (Hc) were found to be in the range of 34.29–43.711 emu/g and 16.27–299.441 Oe, respectively. The improved values of Ms and Hc mean that these powders can be used as pre-eminent contestant materials for perpendicular recording media (PMR) applications. In addition, the synthesized Co2Y-type nanohexaferrites were characterized for the Mössbauer analysis at room temperature. The normal Zeeman (six-line patterns) splitting confirms the hexagonal phase of synthesized nanohexaferrites.

Quality control of solar radiation data within the South African Weather Service solar radiometric network

This study reports on the performance results of the Baseline Surface Radiation Network (BSRN) quality control procedures applied to the solar radiation data, from September 2013 to December 2017, within the South African Weather Service radiometric network. The overall percentage performance of the SAWS solar radiation network based on BSRN quality control methodology was 97.79%, 93.64%, 91.60% and 92.23% for long wave downward irradiance (LWD), global horizontal irradiance (GHI), diffuse horizontal irradiance (DHI) and direct normal irradiance (DNI), respectively, with operational problems largely dominating the percentage of bad data. The overall average performance of the surface solar radiation dataset – Heliosat data records for the GHI estimation for all stations showed a mean bias deviation of 8.28 Wm-2, a mean absolute deviation of 9.06 Wm-2 and the root mean square deviation of 11.02 Wm-2. The correlation, quantified by the square of correlation coefficient (R2), between ground-based and Heliosat-derived GHI time series was ~0.98. The established network has the potential to provide high quality minute solar radiation data sets (GHI, DHI, DNI and LWD) and auxiliary hourly meteorological parameters vital for scientific and practical applications in renewable energy technologies.

Design of a high-spectral-resolution lidar for atmospheric temperature measurement down to the near ground.

In this paper, a high-spectral-resolution lidar (HSRL) for profiling atmospheric temperature from the ground to 10 km is proposed. A double Nd:YAG laser produces the transmitted laser at 532 nm. The backscattering lidar signal is passed through two different saturated iodine-vapor filters and thus obtains molecular scattering signals that can be employed to determine the temperature. A coaxial postposition transceiver is constructed with an off-axis aspheric reflective telescope (OART). The design of the transceiver and that of the OART are demonstrated. With this transceiver, the lidar blind zone where the overlap factor is zero can be reduced greatly, and accurate temperature measurement for full elevation can be achieved. The whole system is optimized with theoretical models based on geometrical optics and statistical error analyses. Monte Carlo simulations display the performance of the designed HSRL, showing that the all-day temperature retrieval error is better than 1.4 K from the ground to 10 km. The proposed HSRL is expected to provide more accurate atmospheric auxiliary parameters for the detection of aerosols' optical characteristics.

Elements of digital energy in the control of the state of the network, built on measurements of auxiliary parameters

The article deals with the issue of transition of power engineering technologies to digital stations. An overview of the Siemens and ABB materials that de facto set standards for digital technology for energy. The creation of digital stations addresses issues that have not been addressed in this connection so far. Therefore, a triad was formed: digital control - equipment state monitoring - cybersecurity. Proceeding from such a triangle, energy in the digital incarnation acquires new faces, which opens up new possibilities for the use of diagnostics and data collection by sensors built on mediated data, and accordingly, the number of sensors increases significantly if we take into account the possibility of monitoring the primary technological processes. In this case, the amount of incoming data grows significantly. In accordance with current trends and increasing requirements for the quality of electricity in the network. One of the factors of the spoofed form of a grid on the network is the crown discharges that occur on the network and on the equipment, even during the interception to the digital station. Leading companies are developing devices and systems for diagnosing the presence of a corona discharge in the network according to non-electronics parameters. An example of such measurements is the ability to diagnose non-direct vemiers in the network. Such measurements should lead to an increase in data volume. Accordingly, the processing of such data arrays becomes possible with the use of digital technologies, which include the ability to process large volumes of data using the mathematical apparatus for processing large data - Data Mining. The results of processing by hardware (software) methods allows to determine or invent such data, which in direct measurements were not visible. Data Mining technologies allow expert estimates to be used on direct measurement data, which will inevitably lead to objectivity. Data Mining, in contrast to expert methods, finds objective patterns between different factors, thus minimizing the influence of the subjective human factor on decision making. The authors draw attention to the promising use of indirect measurement sensors in the power system, which, based on digital technologies, will provide an opportunity for a more profound analysis of real systems, which can lead to qualitative changes in the energy sector as a whole.

Evaluation of geostatistical techniques and their hybrid in modelling of groundwater quality index in the Marand Plain in Iran.

In many parts of the world, groundwater is considered as one of the main sources of urban and rural drinking water. Over the past three decades, the qualitative and quantitative characteristics of aquifers have been negatively affected by different factors such as excessive use of chemical fertilizers in agriculture, indiscreet, and over-exploitation use of groundwater. Therefore, finding the effective method for mapping the water quality index (WQI) is important for locating suitable and non-suitable areas for urban and rural drinking waters. In the present paper, the best method to estimate the spatial distribution of WQI was assessed using the inverse distance weighted, kriging, cokriging, geographically weighted regression (GWR), and hybrid models. Creating hybrid models can increase modeling capabilities. Hybrid methods make use of a combination of estimated model capabilities. In addition, to improve the results of cokriging, GWR, and hybrid methods, the auxiliary parameters of land slope, groundwater table, and groundwater transmissibility were used. In order to assess the proposed methodology, 11 qualitative parameters obtained from 63 observation wells in Marand Plain (Iran) were utilized. Four statistical measures, namely the root mean square error (RMSE), the mean absolute error (MAE), the Akaike coefficient (AIC), and the correlation coefficient (R2) along with the Taylor diagram, have been done. Classification of the WQI index showed that the quality of a number of 1, 27, 18, and 17 wells was, respectively, in excellent, good, moderate, and poor grades. The results of modeling the WQI index based on IDW, kriging, cokriging, GWR, and hybrid methods showed that the best estimate of WQI was obtained by using hybrid GWR-kriging method with three input parameters of land slope, groundwater table, and groundwater transmissibility. Therefore, hybrid kriging and GWR methods have been fairly well able to simulate the WQI index.

Numerical Solutions of Coupled Burgers’ Equations

In this article, two new modified variational iteration algorithms are investigated for the numerical solution of coupled Burgers’ equations. These modifications are made with the help of auxiliary parameters to speed up the convergence rate of the series solutions. Three numerical test problems are given to judge the behavior of the modified algorithms, and error norms are used to evaluate the accuracy of the method. Numerical simulations are carried out for different values of parameters. The results are also compared with the existing methods in the literature.

Distributionally robust optimization model of active distribution network considering uncertainties of source and load

To ensure the safety and reliability of the distribution network and adapt to the uncertain development of renewable energy sources and loads, a two-stage distributionally robust optimization model is proposed for the active distribution network (ADN) optimization problem considering the uncertainties of the source and load in this paper. By establishing an ambiguity set to capture the uncertainties of the photovoltaic (PV) power, wind power and load, the piecewise-linear function and auxiliary parameters are introduced to help characterize the probability distribution of uncertain variables. The optimization goal of the model is to minimize the total expected cost under the worst-case distribution in the ambiguity set. The first-stage expected cost is obtained based on the predicted value of the uncertainty variable. The second-stage expected cost is based on the actual value of the uncertainty variable to solve the first-stage decision. The generalized linear decision rule approximates the two-stage optimization model, and the affine function is introduced to provide a closer approximation to the second-stage optimization model. Finally, the improved IEEE 33-node and IEEE 118-node systems are simulated and analyzed with deterministic methods, stochastic programming, and robust optimization methods to verify the feasibility and superiority of the proposed model and algorithm.

Service life assessment of renders on the basis of changes of physical and mechanical properties during simulated weathering

The article presents a method for the estimation of service life of renders for selected physical and mechanical properties whereof values have been determined in the accelerated ageing tests. The ageing tests were performed in simulated conditions with 500 cycles, and for comparison, in natural conditions for the period of 2 years. To describe the ageing characteristics, specific qualities were applied for which the changes demonstrated a monotonic character and which enabled at the same time to determine a limit performance value, which is required when formulating models of durability. The above quality demonstrated changes in bulk density and adhesion to the substrate. Statistical models of durability based on time series were developed for those qualities. The optimal fit of the models was demonstrated by means of a statistical test confirming the normal distribution of random residuals. In addition to the description of the degradation process, a modified model of concrete surface degradation determining mass losses was adopted. The empirical values of such qualities as: compressive strength, porosity, adhesive strength and vapor permeability were used as auxiliary parameters of the model. The experimental verification of mass losses allowed for a successful application of the model.

Lactatemia e glicemia na síndrome cólica de equinos: revisão

Colic syndrome is the disease that most affects and causes death in horses. The diagnosis and decision of treatment should be established as soon as possible, considering that time is an essential factor for survival. Lesions that lead to obstruction of the blood flow and intestinal ischemia are strongly related with death. Therefore, the development of research seeking auxiliary parameters in prognosis and diagnosis of acute abdomen in horses is increasingly frequent. The lactate, a product of anaerobic glycolysis, is evaluated in athlete horses with critical illnesses. In equine colic, in high concentrations, it is related to ischemic intestinal lesions and mortality. Hyperglycemia is common in these animals, and despite little research, has a relation with worse prognosis. According to existing studies, the concentration of lactate and glucose together can be used as a predictor of prognosis. Besides that, higher lactate levels in the equine peritoneal fluid are indicative of intestinal strangulation and ischemia. This review presents the biochemistry of glucose and lactate, types of measurements and researches performed on equine colic syndrome that relates those data with prognosis and survival rates.

Numerical solutions of nonlinear fractional model arising in the appearance of the strip patterns in two-dimensional systems

The main aim of this paper is to present a comparative study of modified analytical technique based on auxiliary parameters and residual power series method (RPSM) for Newell–Whitehead–Segel (NWS) equations of arbitrary order. The NWS equation is well defined and a famous nonlinear physical model, which is characterized by the presence of the strip patterns in two-dimensional systems and application in many areas such as mechanics, chemistry, and bioengineering. In this paper, we implement a modified analytical method based on auxiliary parameters and residual power series techniques to obtain quick and accurate solutions of the time-fractional NWS equations. Comparison of the obtained solutions with the present solutions reveal that both powerful analytical techniques are productive, fruitful, and adequate in solving any kind of nonlinear partial differential equations arising in several physical phenomena. We addressed L_{2} and L_{infty } norms in both cases. Through error analysis and numerical simulation, we have compared approximate solutions obtained by two present aforesaid methods and noted excellent agreement. In this study, we use the fractional operators in Caputo sense.