INFLUENCE OF SPATIAL ORIENTATION OF FRAME BUILDINGS ON METAL CAPACITY OF STEEL COLUMNS

The calculated values of wind pressure are identified without taking into account changes in wind speed and pressure from different directions. Current load standards in Ukraine allow taking into account the decreasing coefficients of wind direction if there is sufficient statistical justification and when the objects are located on open flat terrain. The purpose of this work is to identify possible effect of considering the orientation of frame buildings and corresponding coefficients of the wind direction when designing steel columns of one-story frame buildings. By analyzing design and calculated parameters of one-story industrial and civil buildings, possible limits of their change were established, and a plan for the experimental design of columns from broad-flanged rolling H-beams was developed and implemented. A dependence was obtained and described by analytical expression that allow forecasting steel consumption for the columns of single-aisle one-story buildings, taking into account their height, total load from roof and active component of wind pressure. Based on the results of earlier studies, the characteristic values of wind pressure and generalized wind direction coefficients were established for each of 25 regions of Ukraine. For most part of the territory of Ukraine, minimum wind loads are realized when wind directions are north-south or north-east-south-west. Generalized wind direction coefficients, together with the formula for the forecasting mass of columns, made it possible to identify possible savings in steel on the columns of one-story buildings taking into account spatial orientation of buildings. On average, throughout the territory of Ukraine, metal consumption of rolling columns decreases by 4.2%, and in some cases, depending on the region, wind direction and building height, it can decrease to 17.5%. Significant influence of the underlying surface and surrounding buildings on the nature of the wind flow allows wind direction coefficients to be taken into account only when calculating the frames of buildings located in an open flat area, under conditions that their values are statistically substantiated using the results of wind observations at nearest meteorological stations.

Ensuring Consumer Satisfaction of Products in the Quality System of the Enterprise Based on the Application of the “Consumer's Risks” method

The paper deals with the basics of ensuring customer satisfaction as one of the conceptual principles of the quality management system (QMS) of the enterprise, based on "Consumer's risks" method, which is a modification of the well-known "Consumer Voice" method. The paper analyzes scientific approaches to the problem under study. The paper gives ground for the prospects of studying personal risks of consumers in order to anticipate their expectations from the company's products based on the application of "Consumer's risks" method, which allows to extrapolate the risks of interested parties to the product characteristics expressed in professional terminology that is understandable for the manufacturer who can implement it. The authors propose a procedure for transferring consumer’s risks into product characteristics and a statistical justification of the priority of their implementation, which allows to balance the requirements of all interested parties. The expediency of using the developed procedure in order to ensure customer satisfaction and increase the competitiveness of the enterprise is proved.

Rapid Characterisation of Suspensions for Waste Treatment and Resource Recovery

A simple device for the conduct of stepped pressure filtration measurements is described together with methods for making the empirical measurements and interpreting the data obtained. The data interpretation method applies a multi-step systematic approach, with each step supported by statistical justification, to characterise: filter cake particle stress, filtration diffusivity and cake hydraulic resistivity from a single stepped pressure experiment. The methods enable different flocculant materials to be more rapidly and more appropriately screened than conventional jar tests and large scale filtration trials. The methods are applied to the characterisation of a paint residue treated with aluminium sulphate and “PolyClay”.<br>The work shows that the addition of “PolyClay” as a filter aide reduces the hydraulic resistivity at lower solids concentrations but increases it at higher concentrations whilst simultaneously increasing the particle stress. Together these have a combined deleterious effect on the time and energy required to dewater the residues to high solids concentration by filtration. The results also show that a significant change in suspension behaviour occurs between the “PolyClay” doses of 140 mg l^-1 and 660 mg l^-1 and that further changes up to “PolyClay” doses of 1600 mg l^-1 are more modest. The results indicate the existence an opportunity to reduce “PolyClay” dose into a range between 10% and 50% of current practice. In addition the results provide evidence that alternative, centrifuge based, technology is worthy of investigation.

Rapid Characterisation of Suspensions for Waste Treatment and Resource Recovery

A simple device for the conduct of stepped pressure filtration measurements is described together with methods for making the empirical measurements and interpreting the data obtained. The data interpretation method applies a multi-step systematic approach, with each step supported by statistical justification, to characterise: filter cake particle stress, filtration diffusivity and cake hydraulic resistivity from a single stepped pressure experiment. The methods enable different flocculant materials to be more rapidly and more appropriately screened than conventional jar tests and large scale filtration trials. The methods are applied to the characterisation of a paint residue treated with aluminium sulphate and “PolyClay”.<br>The work shows that the addition of “PolyClay” as a filter aide reduces the hydraulic resistivity at lower solids concentrations but increases it at higher concentrations whilst simultaneously increasing the particle stress. Together these have a combined deleterious effect on the time and energy required to dewater the residues to high solids concentration by filtration. The results also show that a significant change in suspension behaviour occurs between the “PolyClay” doses of 140 mg l^-1 and 660 mg l^-1 and that further changes up to “PolyClay” doses of 1600 mg l^-1 are more modest. The results indicate the existence an opportunity to reduce “PolyClay” dose into a range between 10% and 50% of current practice. In addition the results provide evidence that alternative, centrifuge based, technology is worthy of investigation.

Testing the Missing Mechanism of Demographic and Health Variables in the Health and Retirement Study

Studies using data from longitudinal health survey of older adults usually assumed the data were missing completely at random (MCAR) or missing at random (MAR). Thus subsequent analyses used multiple imputation or likelihood-based method to handle missing data. However, little existing research actually examines whether the data met the MCAR/MAR assumptions before performing data analyses. This study first summarized the commonly used statistical methods to test missing mechanism and discussed their application conditions. Then using two-wave longitudinal data from the Health and Retirement Study (HRS; wave 2014-2015 and wave 2016-2017; N=18,747), this study applied different approaches to test the missing mechanism of several demographic and health variables. These approaches included Little’s test, logistic regression method, nonparametric tests, false discovery rate, and others. Results indicated the data did not meet the MCAR assumption even though they had a very low rate of missing values. Demographic variables provided good auxiliary information for health variables. Health measures (e.g., self-reported health, activity of daily life, depressive symptoms) met the MAR assumptions. Older respondents could drop out and die in the longitudinal survey, but attrition did not significantly affect the MAR assumption. Our findings supported the MAR assumptions for the demographic and health variables in HRS, and therefore provided statistical justification to HRS researchers about using imputation or likelihood-based methods to deal with missing data. However, researchers are strongly encouraged to test the missing mechanism of the specific variables/data they choose when using a new dataset.

Statistics of spatial rotations and projection directions considering molecular symmetry in 3D electron cryo-microscopy

Electron cryo-microscopy (cryoEM) three-dimensional (3D) reconstruction is based on estimations of orientations of projection images or 3D volumes. It is common that the macromolecules studied by cryoEM have molecular symmetry, which, unfortunately, has not been taken into consideration by any statistics for either spatial rotations or projection directions at this point. Meanwhile, there are growing needs to adopt advanced statistical methods, and further, modern machine learning techniques in cryoEM. Since those methodologies are built heavily upon statistical learning cornerstones, the absence of their domain-specific statistical justification limits their applications in cryoEM. In this research, based on the concept of non-unique-games (NUG), we propose two key statistical measurements, the mean and the variance, of both spatial rotations and projection directions when molecular symmetry is considered. Such methods are implemented in the open-source python package pySymStat.

Motto: Representing Motifs in Consensus Sequences with Minimum Information Loss

Sequence analysis frequently requires intuitive understanding and convenient representation of motifs. Typically, motifs are represented as position weight matrices (PWMs) and visualized using sequence logos. However, in many scenarios, in order to interpret the motif information or search for motif matches, it is compact and sufficient to represent motifs by wildcard-style consensus sequences (such as [GC][AT]GATAAG[GAC]). Based on mutual information theory and Jensen-Shannon divergence, we propose a mathematical framework to minimize the information loss in converting PWMs to consensus sequences. We name this representation as sequence Motto and have implemented an efficient algorithm with flexible options for converting motif PWMs into Motto from nucleotides, amino acids, and customized characters. We show that this representation provides a simple and efficient way to identify the binding sites of 1156 common transcription factors (TFs) in the human genome. The effectiveness of the method was benchmarked by comparing sequence matches found by Motto with PWM scanning results found by FIMO. On average, our method achieves a 0.81 area under the precision-recall curve, significantly (P-value < 0.01) outperforming all existing methods, including maximal positional weight, Cavener’s method, and minimal mean square error. We believe this representation provides a distilled summary of a motif, as well as the statistical justification.

Errors in the statistical justification for the "credibility ceiling" remain uncorrected

To appear in Journal of Clinical Epidemiology