Three-stage Procedure Research Articles

High-precision absolute linear encoder based on a standard calibrated scale

This paper presents the full research and development cycle of a high-precision absolute linear encoder based on a standard calibrated scale. Already available and used in industry standard scales of invar alloy were employed in the study. The scales have incremental indexes with 1 mm spacing intervals without an absolute code. However, the existing technical task is to measure the absolute position in the range of 2 m with accuracy less than 5 μm. For that, the developed encoder rationally combines magnetic measuring channel for the index numbering and an optical channel for the precise estimation of the encoder position. First, for the development, a simulation was performed to synthesize and analyze an image of an index. This image was used to develop a real-time double-threshold image processing algorithm to estimate the index position. Later the developed image processing algorithm was verified by preliminary testing and supported by a presented three-stage calibration procedure. The final measurements proved that the designed and developed encoder has the accuracy of 1.65 μm (3 standard deviations) at the speed up to 3 m/s. The possibility of use of standard calibrated scales with the presented encoder to solve existing and new industrial tasks forms the value of this paper. A possible use of the existing scales also provides unification and compatibility with conventional metrology equipment.

New invariances for chemical reactions from Scaled Incremental Conversion (SIC)

For the two-step chemical reaction A ⇄ B ⇄ C, invariant dependences of a new type have been found. These invariants relate concentration dependences which are started from the single component (single-component-dependences). For constructing the invariants, a three-stage procedure is used:1.Scaled Incremental Conversion (SIC), χ, is determined for any substance as χ=X(t)-XoXeq-Xo, where Xeq and Xo are equilibrium and initial concentrations for any substance, A, B, or C, respectively; X(t) is the concentration at any moment of time.2.Differences of SIC terms Δχ are determined for different pairs of substances. SIC terms are calculated in experiments with symmetrical initial conditions.3.A generating function of invariants is constructed which produces invariants as ratios of different Δχ. These ratios remain constant at any time during the non-steady-state reaction.It is demonstrated that the variety of invariants obtained depends on the initial conditions used in the procedure. Explicit analytical expressions have been found assuming the same initial conditions, two, and three different initial conditions, respectively.All invariants are functions of three independent parameters which are ratios of kinetic coefficients. Two of them are equilibrium reaction constants, and the third one is the ratio of kinetic coefficients belonging to different reactions.

Traffic assignment in a tolled network with heterogeneous values of time and budgets on toll

A new network equilibrium problem was proposed for evaluating tolled traffic networks with heterogeneous values of time (VoT) and budgets on toll (BoT). Both parameters are important socio-economic characteristics primarily determined by the income level, trip purpose, etc., which directly affect the route choice and network flow pattern. Simpler models that embrace either of the attributes appeared a few times in the literature, but no study has been devoted to including both of them in an integrated model. This paper presents a mathematical programming model and method to characterize and solve this problem. In the well-known Frank-Wolfe algorithm framework, the core solution complexity lies in how to load travel demand into the network in an efficient manner. For tackling this difficulty, we developed a three-stage network loading procedure: (1) a bicriterion label-correcting algorithm finds all nondominated paths in the first stage; (2) a Graham scan algorithm is used to quickly identify all extreme nondominated paths in the second stage; (3) a constrained parametric algorithm is used to assign appropriate demand proportions to all eligible extreme nondominated paths. The numerical result derived from an illustrative example clearly shows how heterogeneous BoT and VoT reshape the network flow pattern from the simple case characterized merely by user equilibrium.

English

The paper examines the status and determinants of poverty and inequality among rural households in Girar Jarso district of Central Ethiopia. To measure the status of poverty and inequality, the study made use of cost of basic need approach, Foster-Greer-Thorbecke indices and Gini coefficient. Based on the survey of 120 households, the logistic model was estimated. A three-stage sampling procedure was applied for selection of respondents. The poverty line is found to be 4315.7 Ethiopian Birr. The incidence of poverty was computed to be 45% with an average poverty gap and squared poverty gap of 18.6 and 9.99%, respectively. The Gini coefficient was calculated to be 0.33. The logit model shed light on the demographic and socioeconomic characteristics of households behind the persistence of poverty. The result revealed that poverty is strongly linked to family size, remittance, farm and non-farm income and receiving food aid. The findings suggest also that livelihood diversification, encouraging flow of remittances, promotion of non-farm activities, besides agricultural intensification, and appropriate target to avoid distortionary effects of food aid will constitute an important strategy to accelerate poverty reduction. Key words: Poverty, income inequality, determinants, household, Ethiopia.

Spatial Distribution, Chemical Fraction and Fuzzy Comprehensive Risk Assessment of Heavy Metals in Surface Sediments from the Honghu Lake, China.

Spatial concentrations and chemical fractions of heavy metals (Cr, Cu, Pb, Zn and Cd) in 16 sampling sites from the Honghu Lake were investigated using an atomic absorption spectrophotometer and optimized BCR (the European Community Bureau of Reference) three-stage extraction procedure. Compared with the corresponding probable effect levels (PELs), adverse biological effects of the studied five sediment metals decreased in the sequence of Cr > Cu > Zn > Pb > Cd. Geo-accumulation index (Igeo) values for Cr, Cu, Pb and Zn in each sampling site were at un-contamination level, while the values for Cd varied from un-contamination level to moderate contamination level. Spatially, the enrichment degree of Cd in lower part of the South Lake, the west part of the North Lake and the outlet were higher than the other parts of Honghu Lake. For metal chemical fractions, the proportions of the acid-extractable fraction of five metal contents were in the descending order: Cd, Cu, Zn, Pb and Cr. Cd had the highest bioaccessibility. Being the above indexes focused always on heavy metals’ total content or chemical fraction in deterministic assessment system, which may confuse decision makers, the fuzzy comprehensive risk assessment method was established based on PEI (Potential ecological risk index), RAC (Risk assessment code) and fuzzy theory. Average comprehensive risks of heavy metals in sediments revealed the following orders: Cd (considerable risk) > Cu (moderate risk) > Zn (low risk) > Pb > Cr. Thus, Cd and Cu were determined as the pollutants of most concern. The central part of South Honghu Lake (S4, S5, S6, S9, S12 and S14), east part of the North Honghu Lake (S1) and outlet of outlet of the Honghu Lake (S10) were recommended as the priority control areas. Specifically, it is necessary to pay more attention to S1, S4, S5, S6, S9 and S16 when decision making for their calculated membership values (probabilities) of adjacent risk levels quite close.

Causality nexus of exports, FDI and economic growth of the ASEAN5 economies: evidence from panel data analysis

ABSTRACTThis paper analyzes the causal relationships between exports, FDI and economic growth among the ASEAN5 countries. We have used a three-stage procedure based on unit root, co-integration and causality tests applied to the panel data from 1981 to 2013. The results reveal that there is a bi-directional causal relationship between FDI and growth in the long run, while there is a unidirectional causal relationship from FDI to exports in the short run. Our results also confirm that the export-led growth (ELG) and FDI-led growth hypotheses hold true in the long and short run. To reinforce the FDI inflows, authorities should continue the progressive reduction of barriers, and increase the sophistication of quality exports to compete in the global market. This paper is the first of its kind to analyze the role of both FDI and exports in the ASEAN5 economies using panel analysis.

Synthesis of the equipment health management system of the turbine units' of thermal power stations

The aim of the research is the development of technical diagnostics subsystem with the possibility of its further integration into the automated system of equipment health management, which will improve the efficiency of data ware, hardware and software. Synthesis of intellectual diagnostic models was produced a by using the Matlab graphical agents. At the same time, there were synthesized models of three types: fuzzy, neural-network and model built by planning the full factorial experimental method. Was proposed the concept of the three-stage procedure of the diagnosis of the thermal power station's turbine unit, instead of the creation of diagnosis mathematical models and failure models of objects, immediately begin to develop an algorithm of diagnosis using advanced intelligent technologies. The technique of creating a sub-line diagnostics status of the turbine unit, which includes three main stages: identification of diagnostic features based on expert method; the synthesis of diagnostic model of the facility technical condition; research models on the stability, sensitivity and uniqueness, was proposed. The main diagnostic features of assessing the state of turbine equipment, which, in accordance with the concept developed, allow forming a matrix of planning a full factorial experiment. The proposed techniques and concepts were subjected to experimental verification. The intellectual diagnostic model of turbine unit equipment health was proposed, synthesized and investigated. It was found that the best model is the model, built using neuro-fuzzy algorithms. The simulation was provided for neuro-fuzzy algorithms and confirmed their effectiveness and compliance with the laws of the physical functioning of the HPC. The results of this research have been used in the development of Almaty CHP-2 turbine equipment health management subsystems, allow the further development of the theoretical foundations of intellectual systems, and demonstrate the possibility of using modern concepts to solve important technical problems. Subsystem of operative diagnosis and the following software implementation in a complex of automated technological process of thermal power control system allows one to make an early diagnosis of the equipment health. This significantly reduces the maintenance costs, improves reliability and security, as well as the effectiveness of the control system. In this regard, the results of this study provide further development of the theoretical foundations of the intellectual systems and demonstrate the possibility of modern concepts usage to determinate the important technical problems.

A multidimensional spatial lag panel data model with spatial moving average nested random effects errors

This paper focuses on a three-dimensional model that combines two different types of spatial interaction effects, i.e. endogenous interaction effects via a spatial lag on the dependent variable and interaction effects among the disturbances via a spatial moving average (SMA) nested random effects errors. A three-stage procedure is proposed to estimate the parameters. In a first stage, the spatial lag panel data model is estimated using an instrumental variable (IV) estimator. In a second stage, a generalized moments (GM) approach is developed to estimate the SMA parameter and the variance components of the disturbance process using IV residuals from the first stage. In a third stage, to purge the equation of the specific structure of the disturbances a Cochrane–Orcutt-type transformation is applied combined with the IV principle. This leads to the GM spatial IV estimator and the regression parameter estimates. Monte Carlo simulations show that our estimators are not very different in terms of root mean square error from those produced by maximum likelihood. The approach is applied to European Union regional employment data for regions nested within countries.

Quantile regression for robust inference on varying coefficient partially nonlinear models

In this paper, we propose a robust statistical inference approach for the varying coefficient partially nonlinear models based on quantile regression. A three-stage estimation procedure is developed to estimate the parameter and coefficient functions involved in the model. Under some mild regularity conditions, the asymptotic properties of the resulted estimators are established. Some simulation studies are conducted to evaluate the finite performance as well as the robustness of our proposed quantile regression method versus the well known profile least squares estimation procedure. Moreover, the Boston housing price data is given to further illustrate the application of the new method.

Multi-criteria group decision making under uncertainty: Application in reservoir flood control operation

This paper proposes an innovative framework for solving stochastic multi-criteria decision making (MCDM) problems when uncertainties exist in criteria performance values (PVs) and criteria weights (CWs) simultaneously. Methods for quantifying uncertainties in criteria PVs and CWs are presented. We establish the SMAA-TOPSIS model by combining stochastic multicriteria acceptability analysis (SMAA) and technique for order preference by similarity to ideal solution (TOPSIS). The risk of decision making errors is proposed to assess the impact of uncertainties on MCDM. We develop the LHS-based Monte Carlo simulation algorithm and corresponding computer program for solving the SMAA-TOPSIS model. We also suggest a three-stage MCDM procedure for stochastic MCDM problems. We apply the proposed methodology to a flood control operation case study to demonstrate its applicability. Our results indicate that the proposed methods can provide valuable risk information and enable risk-informed decisions to be made with higher reliabilities.

Prevalence of severe early childhood caries and associated socioeconomic and behavioral factors in Xinjiang, China: a cross-sectional study

BackgroundThis study assessed the prevalence and severity of early childhood caries (ECC) and identified socioeconomic and behavioral correlates of the disease in preschool children living in Xinjiang.MethodsFor this cross-sectional survey, 1727 children aged 3–5 years in Xinjiang were randomly recruited using a three-stage cluster sampling procedure. The “dmft” index according to the WHO 1997 criteria was used to assess ECC and severe ECC (S-ECC). A questionnaire was completed by caregivers. Variables included sociodemographic characteristics, dietary and oral hygiene behaviors, and access to dental services. The statistical associations of variables with ECC, S-ECC, and dmft were evaluated by univariate and multiple logistic regression analyses.ResultsThe prevalence of ECC was 78.2% and that of S-ECC was 41.2%; mean dmft scores were 5.61 ± 3.56 and 8.17 ± 2.94, respectively. The prevalence of ECC was significantly higher in children from Ining (OR 2.747; 95% CI 2.033–3.713), those whose caregivers had caries (OR 1.78; 95% CI 1.245–2.547), those with a dental visit in the past (OR 2.023; 95% CI 1.429–2.865), and those whose parents had received instructions on oral health care (OR 2.171; 95% CI 1.44–3.272), and increased significantly at age 4 years (OR 2.09; 95% CI 1.506–2.901) and 5 years (OR 2.666; 95% CI 1.855–3.833) and in children who starting tooth brushing at a young age (OR 1.363; 95% CI 1.171–1.587), and decreased significantly in children with a more educated mother (OR 0.817; 95% CI 0.688–1), those from high-income families (OR 0.667; 95% CI 0.582–0.765), those with low consumption of sweets (OR 0.66; 95% CI 0.57–0.763), and those who seldom ate before sleep (OR 0.557; 95% CI 0.437–0.712).ConclusionsECC and S-ECC remain a serious problem among preschool children in Xinjiang. Caries rates were associated with sociodemographic and behavioral factors, which could be modified by public health strategies, including protection of primary dentition, extension of insurance to cover oral preventive services, improvement of the oral health care system, and public health education.

Three-stage confidence intervals for a linear combination of locations of two negative exponential distributions

Mukhopadhyay and Padmanabhan (Metrika 40:121–128, 1993) considered the construction of fixed-width confidence intervals for the difference of location parameters of two negative exponential distributions via triple sampling when the scale parameters are unknown and unequal. Under the same setting, this paper deals with the problem of fixed-width confidence interval estimation for a linear combination of location parameters, using the above mentioned three-stage procedure.

The MEQUAL scale: measure of service quality in management education

PurposeThe purpose of this paper is to develop an empirically validated scale to measure the students’ perception of service quality in management education.Design/methodology/approachIn this study, a three-stage systematic procedure of scale development has been adopted. Initially, extant literature review delineated the construct. Exploratory study techniques like focus group study and expert opinion helped in purifying the scale. In the second stage, principal component analysis with varimax rotation and Kaiser normalization (exploratory factor analysis) was used to refine the scale. Finally, multi-trait-multimethod matrix analysis was done to test the reliability and validity of the scale.FindingsA 25-item multi-dimensional construct with six factors (academic aspect, professional assurance, behavioral responses and supports, industry institute interaction, non-academic aspects and physical support) was derived scientifically for measuring service quality in management education. Psychometrically, the scale exhibits internal consistency and remains consistent across the samples. The scale passes the requisite reliability and validity tests (construct, convergent, discriminant, nomological, predictive) with all values within limits.Practical implicationsScientific and structured multi-dimensional construct for service quality in management education will help academicians, administrators and regulators in designing a process-oriented system for enhanced student satisfaction and performance.Originality/valueThis study is an incremental attempt to develop an empirically validated scale for measuring the service quality level and resultant satisfaction in management education.

Comparative Analysis of Sequential Leaching Procedures for Dissociation of Rare Earth Elements in Gold-Bearing Material

Sequential leaching of gold-bearing ore of the residuum is described. The interconnection between rare earth elements and their mineral matrix is defined. The mobility of REE in the initial ore and during hypergenesis is assessed. Two kinds of REE are revealed: fine monazite cerium–neodymium crusts in iron-bearing minerals and dense monazite pockets in titanium-bearing minerals. The five-stage sequential leaching procedure allows more detailed distribution of elements in the rebellious matrix while the threestage procedure focuses on mobile forms.

Bounded risk estimation of a linear combination of location parameters in negative exponential distributions via three-stage sampling

ABSTRACTThe paper deals with the problem of bounded risk point estimation for a linear combination of location parameters of two negative exponential distributions. Isogai and Futschik considered the situation when the location and scale parameters are all unknown. They proposed purely sequential procedures and gave second order expansions of the average sample sizes and risks. In this paper we propose three-stage procedures and derive second order expansions of the average sample sizes and risks. Further, we compare the results with those from previous work.

Design of measurement matrix in CS-MIMO radar for extended target estimation

In this paper, we propose a measurement matrix design that improves the parameter estimation of an extended target in a compressive sensing multiple-input multiple-output (CS-MIMO) radar system. In our signal model, we consider the target impulse response (TIR) as an unknown vector that should be estimated in a compressive sensing scenario. Our proposed measurement matrix optimization method is based on minimizing the trace of the Cramer–Rao lower bound (CRLB) matrix in the presence of signal-dependent interference and receiver noise, which leads to a nonlinear and non-convex optimization problem. To tackle design problem, we propose a three-stage optimization procedure in which a low rank matrix constraint is enforced. For comparison purpose, we also obtain the measurement matrix based on minimizing the block-coherence of the sensing matrix blocks. Numerical results demonstrate the effectiveness of our proposed method in parameter estimation of extended targets for CS-MIMO radar.

Electrical properties of La0.85Sr0.15Ga0.8Mg0.2O3−δ samples prepared by one- or three-stage solid-state calcination process

La0.85Sr0.15Ga0.8Mg0.2O3−δ (LSGM1520) samples are prepared by one- or three-stage solid-state calcination process. The influence of calcination and sintering parameters on the densification, grain size, phase structure, conductivity, and activation energy of LSGM1520 electrolyte samples are investigated and the most suitable process method is identified. The results show that the three-stage calcination procedure is effective in preparing higher purity LSGM1520 powders than those obtained with the traditional one-stage calcination procedure. Conductivities of the A2 and C4 electrolyte samples at 800 °C are 0.18 and 0.17 S cm−1, respectively. The A2 and C4 of LSGM1520 electrolyte samples are from the one-stage and three-stage calcination procedures, respectively. The open-circuit voltage and maximum power density values of cells prepared using A2 and C4 as electrolytes at 800 °C are 1.01 V and 370 mW cm−2, and 0.97 V and 367 mW cm−2, respectively. Hence, the A2 electrolyte sample, prepared though a simpler process than the C4 electrolyte, displays good cell performance. Although the A2 sample contains a very small amount of secondary phase, its conductivity and cell performance are not significantly reduced at temperatures above 700 °C, as expected.

Discrete Multimodal Hashing With Canonical Views for Robust Mobile Landmark Search

Mobile landmark search (MLS) recently receives increasing attention for its great practical values. However, it still remains unsolved due to two important challenges. One is high bandwidth consumption of query transmission, and the other is the huge visual variations of query images sent from mobile devices. In this paper, we propose a novel hashing scheme, named as canonical view based discrete multi-modal hashing (CV-DMH), to handle these problems via a novel three-stage learning procedure. First, a submodular function is designed to measure visual representativeness and redundancy of a view set. With it, canonical views, which capture key visual appearances of landmark with limited redundancy, are efficiently discovered with an iterative mining strategy. Second, multi-modal sparse coding is applied to transform visual features from multiple modalities into an intermediate representation. It can robustly and adaptively characterize visual contents of varied landmark images with certain canonical views. Finally, compact binary codes are learned on intermediate representation within a tailored discrete binary embedding model which preserves visual relations of images measured with canonical views and removes the involved noises. In this part, we develop a new augmented Lagrangian multiplier (ALM) based optimization method to directly solve the discrete binary codes. We can not only explicitly deal with the discrete constraint, but also consider the bit-uncorrelated constraint and balance constraint together. Experiments on real world landmark datasets demonstrate the superior performance of CV-DMH over several state-of-the-art methods.

Exposure to Hardship Financing for Healthcare among Rural Poor in Chhattisgarh, India

Background: This article examines the exposure of hardship financing in a cross-section of households in four blocks of Rajnandgaon district in Chhattisgarh state, India. We define hardship financing as having to borrow money with interest or to sell assets to pay out-of-pocket healthcare costs. Methods: We used survey data of 4,600 low-income rural households using a three-stage cluster sampling procedure. In first stage, blocks were selected purposively, the second stage involved selection of villages using probability proportional to size (PPS) sampling and lastly, households were randomly selected. Binary logistics regression analysis was used to identify the determinants of exposure to hardship financing related to out-of-pocket expenses for healthcare. Results: About 14.9 per cent of the total households were exposed to hardship financing. Hardship financing occurs not only for hospitalization (nearly 10 per cent) but also for outpatient care (7.91 per cent) and maternity (around 10 per cent). Our logistics regression revealed that health expenditure in the last year was positively associated with the risk for hardship financing. Other correlates of hardship financing included education-level of the head of the household, in-house toilet facility and place of residence/blocks. Conclusion: Rural households, especially the poorer households, spend higher average healthcare payments and are exposed to hardship financing on health.

Potential toxic trace element (PTE) contamination in Baoji urban soil (NW China): spatial distribution, mobility behavior, and health risk.

Rapid urbanization and industrialization may cause increased exposure levels to potential toxic trace elements (PTEs) and associated health risks for population living in cities. The main objectives of this study are to investigate systematically the occurrence, source, fate, and risk of PTE contamination from industrial influence in Baoji urban soil. Seven PTE levels (Pb, Zn, Cu, Cr, V, Sb, and As) were surveyed in 50 composite samples from Baoji urban soil by wavelength dispersive X-ray fluorescence spectrometry. Results reveal that the long-term industrial activities have increased PTEs Pb (409.20mg/kg mean value), Cu (107.19mg/kg mean value), Zn (374.47mg/kg mean value), and Sb (26.00mg/kg mean value) to enrich in urban soil at the different extents. The same results concur with the significant similarity of spatial distribution patterns of Pb, Zn, Cu, and Sb (slightly similar distribution) interpolated by GIS, implying a considerable Pb, Zn, Cu, and Sb contamination pool in urban soil disturbance from local metallic industrial activities. Whereas As in study area mainly controls parent material leaching and therefore has natural sources. Cr and V with the heterogeneous spatial distributions are possibly inclined to coal combustion sources. Those conclusions are also confirmed by the results of multivariate analysis. The chemical forms of PTEs fractionated by BCR three-stage sequential extraction procedure show that Pb and Cu are highly associated to the reducible phase (62.55 and 36.41%, respectively). However, Zn is highly associated to the oxidizable phase (33.68%), and a significant concentration is associated to acid and water extractable fractionation of 15.93% for Zn and 34.40% for Pb. In contrast, As, Cr, V, and Sb are mainly bound to the residual phase (>65% for all elements) with low concentrations retained to water extractable fractionation. The health risk assessed by a new classification Modified Integrate Risk Assessment Code (MI-RAC) reveals that the Pb poses the extremely high risk for human health than others. The results of PTE leaching in organic acids (artificial chelating agent and LMMOAs) indicate that low pH and more carboxyl groups of organic acid can quickly increase the PTEs release from soil and induce more mobility. By comparison, DTPA and EDTA are the effective extractant for Pb and Sb. The leaching kinetics of most PTEs are best described with the Elovich equation model and which involve the ligand exchange (LE) and ligand-enhanced dissolution (LED) two major process. It is a conclusion that long-term metallic industrial activities would accelerate the PTE accumulations in Baoji urban soil and enhance their mobility in a local scale. The considerable mobility and extremely high risk of Pb in Baoji ecoenvironment should be paid more attentions, and the phytoremediation with organic acid leaching assistant could be used to reduce total metal content of multiPTE contaminants in Baoji soils. The research will give the scientific knowledge for controlling the pollution of PTEs in urban soil and can be used as guidance to control the soil pollution in similar cities worldwide.