Accuracy Class Research Articles

Neuro-Immune Model Based on Bio-Inspired Methods for Medical Diagnosis

In this article, a hybrid bio-inspired algorithm called neuro-immune is proposed based on Multi-Layer Perceptron Neural Network (MLPNN) and the Clonal Selection Classification (CSC) principle of the Artificial Immune System (AIS) for the classifying and diagnosing of medical disease. The proposed approach consists in the first phase to code the weights and biases of MLPNN concatenation vector of the input samples into an antigen vector and to decompose it into new weights to generate population memory cells which will be applied by the processes of the CSC algorithm clone and mutate in the second phase, to optimize the accuracy class of data and updating the MLPNN weights to minimize the mean squared error. Experimental results show that the proposed hybrid neuro-immune model allows obtaining a high diagnosis performance on a set of medical data problems from the UCI repository with an improved classification accuracy compared to existing works in the literature.

IAGC: Interactive Attention Graph Convolution Network for Semantic Segmentation of Point Clouds in Building Indoor Environment

Point-based networks have been widely used in the semantic segmentation of point clouds owing to the powerful 3D convolution neural network (CNN) baseline. Most of the current methods resort to intermediate regular representations for reorganizing the structure of point clouds for 3D CNN networks, but they may neglect the inherent contextual information. In our work, we focus on capturing discriminative features with the interactive attention mechanism and propose a novel method consisting of the regional simplified dual attention network and global graph convolution network. Firstly, we cluster homogeneous points into superpoints and construct a superpoint graph to effectively reduce the computation complexity and greatly maintain spatial topological relations among superpoints. Secondly, we integrate cross-position attention and cross-channel attention into a single head attention module and design a novel interactive attention gating (IAG)-based multilayer perceptron (MLP) network (IAG–MLP), which is utilized for the expansion of the receptive field and augmentation of discriminative features in local embeddings. Afterwards, the combination of stacked IAG–MLP blocks and the global graph convolution network, called IAGC, is proposed to learn high-dimensional local features in superpoints and progressively update these local embeddings with the recurrent neural network (RNN) network. Our proposed framework is evaluated on three indoor open benchmarks, and the 6-fold cross-validation results of the S3DIS dataset show that the local IAG–MLP network brings about 1% and 6.1% improvement in overall accuracy (OA) and mean class intersection-over-union (mIoU), respectively, compared with the PointNet local network. Furthermore, our IAGC network outperforms other CNN-based approaches in the ScanNet V2 dataset by at least 7.9% in mIoU. The experimental results indicate that the proposed method can better capture contextual information and achieve competitive overall performance in the semantic segmentation task.

Experimental Method of Machining Gears with an Involute Profile Using CNC Lathe with Driven Tools.

There are many ways of machining gears; the world’s manufacturers of machine tools have patented many methods that allow for the production of gears in an accurate and efficient way. In general, the patented methods require the use of kinematically complex and expensive CNC machine tools. These tools, moreover, the production of the technology itself, including the machining code, require the use of dedicated software. Therefore, it seems justified to strive for the application of kinematically simple and relatively cheap machines in the machining processes so as to increase the universality and availability of new machining methods. This paper presents a method of machining a spur gear with straight teeth with an involute profile using a basic CNC lathe DMG MORI CLX350V4 equipped with driven tools. On the basis of the presented mathematical model, an algorithm was developed to generate a code that controls the machining of cylindrical gears with an involute profile of straight teeth, with the possibility of modifying the transition profile and the tooth root. The machining was experimental, and the gear was made of aluminium AlSi1MgMn using a solid carbide cylindrical cutter. In conclusion, the presented method was found to be very competitive with commercial methods and is able to provide very high quality gears. The accuracy of the machined profile form deviation in the entire processing did not exceed an average value of 10 μm; while assessing the tooth line, the basis average error was 5 μm. Finally, the gear was assessed as manufactured in accuracy class 6. This machining method guarantees very competitive machining cycle times, and thanks to the use of an uncomplicated CNC lathe and universal tools, it provides great flexibility, at the same time giving the possibility of machining gears with arbitrary profiles.

Улучшение условий труда операторов холодной штамповки электромеханического завода путем снижения уровня шума на примере промышленных предприятий Республики Мордовии

The article touches upon one of the urgent problems of our time, namely, the pollution of the industrial environment by industrial noise. Equipment of the enterprises is characterized by a high productivity, the work is accompanied by a significant number of hazardous and harmful production factors, one of which is an increased noise level. The analysis showed that the increased concentration of this phenomenon acts on the human body as a general biological irritant. Changes caused by noise are interpreted in the medical sciences as a «noise disease», which is characterized by hearing loss, changes in the function of digestion, cardiovascular insufficiency, and a functional disorder of the central nervous system. Another negative aspect of the increased noise level is a decrease in labor productivity. The study of noise at the section of cold stamping was conducted as part of a special assessment of the working conditions using an ASSISTANT sound level meter of the first class of accuracy. It was established that the main source of noise in the area under consideration is technological equipment. The sound in the workshop spreads evenly in all the directions, reaching the walls, ceiling, floor, as well as various objects. Upon reaching the target, it is partially absorbed, reflected, and passes through it. Over time, as a result of many reflections from the walls, the ceiling and the equipment located in the workshop, the sound waves form a mixed sound. Thus, there is direct and reflected sound in the cold stamping shop. The conducted studies showed that the most appropriate way to protect cold stamping operators is a set of measures that include sound-absorbing lining of the room in combination with the personal protective equipment, namely, noise-protective headphones. The proposed measures will improve working conditions from harmful class 3 to acceptable class 2.

TLS point cloud as a data surce for multi-lod of 3D models

The development of science and technology had a strong impact on all branches of engineering, including geodesy and the possibility of acquiring and processing measurement data. The best example of this is the Terrestrial Laser Scanning, whih can perform measurements in the form of a multi-million-point cloud. The cloud, representing places and objects, becomes a spatial database. The current problem in engineering is no longer data acquisition and processing, but information excess and redundancy. The solution to this problem is optimisation, which is the process of reducing the amount of data. It should implement its assumptions in such a way as to remove or reduce unnecessary information without losing the information presented by an object. This issue is particularly important in the process of using point clouds in 3D modelling at various levels of detail. The appropriate levels of the LOD0–LOD4 model require a different type of data: on the one hand ensuring the obtainment of the appropriate accuracy class in the study, and on the other hand, the data source should not contain too detailed information that is unnecessary for the study, which makes the work harder and slows it down due to the need to operate on a huge amount of redundant information Therefore, the purpose of this paper is to determine the scope of work on the optimisation of the point cloud in order to adjust its number and quality to the needs of individual LODs. The results of the work allowed to determine the scope of data unification for the respective precision groups of 3D models generating.

АЛГОРИТМ ФУНКЦИОНИРОВАНИЯ ТИПОВОЙ ВЕТВИ АВТОМАТИЗИРОВАННОЙ ИНФОРМАЦИОННОЙ СИСТЕМЫ РЕГУЛИРОВАНИЯ

Relevance Improving the quality of control of dynamic processes in electric power systems involves the widespread introduction of optimal control methods implemented using computer and microprocessor technology. The efficiency of optimal control essentially depends on the class of the mathematical model that describes the processes in electric power systems. The use of power system models of a high accuracy class for choosing control laws does not allow real-time correction of system modes due to the large amount of calculation of the parameters of the optimal controller and insufficient convergence of computational processes. Having a Z-transfer function, it is not difficult to compose difference equations, the very record of which contains an algorithm that is easily programmable on a digital computer, which can ensure the accuracy of the solution for choosing optimal controllers. Aim of research The aim of the work is to apply the algorithm for the functioning of a typical branch of an automated information control system. Research methods For research, the VisSim software environment was used, which, unlike MATLAB, does not require expensive software. VisSim is freely available in the scientific community. To study the effects of frequency fluctuations on the rectified voltage of closed valve systems, the LAFC and LPFC methods were used in combination with the theory of random processes. Results From the point of view of the implementation of the signal processing algorithm, the numerical solutions of differential and difference equations are similar. But the representation and description of a link or fragment of the amplitude-pulse ACS in the form of difference equations allows using, along with models of physical ACS devices, also algorithmic blocks, the functions of which are performed by digital processors.

Electric power metering with its low quality

The issue of electricity metering with low quality is being considered. Special attention is paid to checking the connection metering scheme with low quality of electrical energy. It is shown that a specific circuit design can affect the accuracy of metering of electrical energy in case of poor quality of electrical energy. In distribution networks intended for power supply of industrial enterprises, reactive power is also active. If the consumer has compensating devices, the directions of active and reactive power can be opposite. It is noted that current transformers, selected taking into account the short-circuit current or the characteristics of relay protection, do not provide metering accuracy due to the increased transformation ratio, forcing the installation of an additional set of current transformers or transferring the meters to another point in the network. Thus, the current transformation ratio of the current transformer is somewhat different from the nominal one, and the secondary current vector forms a certain angle with the primary current vector. The voltage error is manifested in a slight decrease in the secondary voltage under load. The angular error is characterized by a certain angle between the vectors of the primary and secondary stress. The value of the errors depends on the load power of the transformer. The maximum allowable voltage drop of the transformer determines the accuracy class. A rated power is set for each accuracy class. Thus, the voltage transformer, depending on the load, can operate in different accuracy classes. Changing the accuracy classes leads to errors in the measurements of metering devices and requires appropriate correction. The article reveals the reasons for the occurrence of such errors, which makes it possible to develop methods and, as a consequence, create devices to prevent the described errors of metering devices.

Informational uncertainty of measuring instruments

Recently, there has been a revival of interest in the use of the information approach in the theory of measurements. Unlike the traditional approach, information theory does not evaluate error or uncertainty, but entropy and the amount of information. This article analyzes a number of recent publications that develop ideas for the information approach. The limitations and disadvantages of both the entropy approach and the concept of uncertainty are indicated. As a compromise solution, it is proposed to use a criterion based on the Bongard’s uncertainty and useful information. The concept of information uncertainty is proposed, which is estimated by the amount of negative useful information, that is, misinformation introduced by the measuring instrument. Some methods for calculating information uncertainty are described.
 The problems of using the uncertainty approach are noted. This approach does not imply the use of such a generalized characteristic of measuring instruments as an accuracy class. The article proposes an analogue of the accuracy class in the form of relative informational uncertainty, expressed as a percentage. This will make it possible to evaluate the quality of the measuring instrument by a single parameter, the calculation of which requires a minimum of computational operations.

Economic damages from low-quality electric energy

The problems of maintaining the quality indicators of electrical energy and, in particular, voltage dips as well as the consequences of voltage dips in electrical networks of industrial enterprises are considered. A classification of electrical consumers according to their sensitivity to voltage dips in critical areas is given. The main measures to prevent technical consequences of voltage dips are described. In order to ensure predictable operation of protection systems, it is necessary to analyse and prepare measures to improve power quality. To this end, high accuracy class recorders can be successfully used and measurements should be made at characteristic points of the network, power centres and at the common connection points of consumers. The consequences of voltage dips have been allocated to economic damage at companies. Without a general account of the damage caused by poor power quality, it is not possible to correctly calculate the economic effect of improving the reliability of technical systems, both in design and in operation. Therefore, it is proposed to use contextual factors of energy efficiency. Hence, an approach to the selection of surge protection measures is derived which requires consideration of the cost-benefit test of the technical measures. Thus, in order to select any of the surge protection measures, it is first necessary to analyse the statistical data, to understand the cause of the equipment outage and then to make a technically and economically sound decision to improve the reliability of the electricity supply. It is possible that the simplest and most effective solution for surge protection may not be in the electrical part but in the process or instrumentation system.

Automated metering and power quality systems in power supply systems

The article shows that the data of the collected by the automated commercial electricity metering systems are an ensemble of daily realizations of random processes of power consumption of the power supply system. The main purpose of using automated systems of commercial and technical electricity metering is to reduce power consumption. But it is noted that the efficiency of using data of the automated commercial electricity metering system, efficiency and proper management of energy consumption depends on the operators of automated workstations. Considering the rapid improvement of both technical means and mathematical methods that can be applied to address energy efficiency issues, there is a need to transform remote data collection systems from electricity meters, taking into account quality, into a measuring and information structure capable of not only collecting data from meters, electrical energy, but also analyse them. The main method for detecting undercounts is given - the balance method. On the basis of the balance method, it is proposed to automatically calculate the unbalance for each section of the 6, 10 or 110 kV line of the main step-down substations and distribution points, taking into account the number and accuracy classes of commercial metering and technical metering devices. It is proposed to balance the load on the results of calculations performed by automated commercial electricity metering system in order to reduce energy losses and reduce payment for electricity. It is proposed in the work that the automated commercial electricity metering system should calculate the coefficients of form, maximum, load, as well as other morphometric characteristics of the graphs of electrical loads. The work drew attention to a number of problems arising in the calculation of these parameters: electronic meters measure the data necessary for calculations but not with the specified discreteness and, most importantly, their measurement of these parameters of the quality of electrical energy is not metrologically certified, therefore, such data can only be relied on as background information.

Mapping of crop types and crop sequences with combined time series of Sentinel-1, Sentinel-2 and Landsat 8 data for Germany

Monitoring agricultural systems becomes increasingly important in the context of global challenges like climate change, biodiversity loss, population growth, and the rising demand for agricultural products. High-resolution, national-scale maps of agricultural land are needed to develop strategies for future sustainable agriculture. However, the characterization of agricultural land cover over large areas and for multiple years remains challenging due to the locally diverse and temporally variable characteristics of cultivated land. We here propose a workflow for generating national agricultural land cover maps on a yearly basis that accounts for varying environmental conditions. We tested the approach by mapping 24 agricultural land cover classes in Germany for the three years 2017, 2018, and 2019, in which the meteorological conditions strongly differed. We used a random forest classifier and dense time series data from Sentinel-2 and Landsat 8 in combination with monthly Sentinel-1 composites and environmental data and evaluated the relative importance of optical, radar, and environmental data.Our results show high overall accuracy and plausible class accuracies for the most dominant crop types across different years despite the strong inter-annual meteorological variability and the presence of drought and non-drought years. The maps show high spatial consistency and good delineation of field parcels. Combining optical, SAR, and environmental data increased overall accuracies by 6% to 10% compared to single sensor approaches, in which optical data outperformed SAR. Overall accuracy ranged between 78% and 80%, and the mapped areas aligned well with agricultural statistics at the regional and national level. Based on the multi-year dataset we mapped major crop sequences of cereals and leaf crops. Most crop sequences were dominated by winter cereals followed by summer cereals. Monocultures of summer cereals were mainly revealed in the Northwest of Germany. We showcased that high spatial and thematic detail in combination with annual mapping will stimulate research on crop cycles and studies to assess the impact of environmental policies on management decisions. Our results demonstrate the capabilities of integrated optical time series and SAR data in combination with variables describing local and seasonal environmental conditions for annual large-area crop type mapping.

Експериментальне визначення стану текстильних матеріалів десантної парашутної системи Д-5 серії 2 після тривалого зберігання. Повідомлення 2. Статистичні характеристики результатів вимірювання показників строп основного парашуту

The subject of the article is the analysis of the array of experimental data of loading and elongation at break of the slings of the main parachute landing parachute systems D-5 series 2 1973 and 1974 years of manufacture after long-term storage with zero (inexhaustible) resource. The current article attempts to determine the ratio of external factors related to the natural factors of aging of polymers, and internal, due to errors in the measurement process, based on statistical analysis of measurement results. Objective: to determine the degree of influence of internal and external factors on the process and result of measuring indicators. The following methods and equipment were used. An improved method of spot sampling of the samples under study of landing parachute systems D-5 series 2 for laboratory studies to determine the load at break and elongation at break of the slings of the main parachute. Measurements were performed on a machine of bursting brand ИР 5047-50M2C, accuracy class - 0.5 for the measurement range from 0.5 kN to 5 kN. The volume of the party was 25 parachute systems, only 250 elementary tests. The array of empirical data was processed by mathematical and statistical methods of the software package Descriptive statistics on the add-on of MS EXCEL Analysis Package. The following results were obtained. The relative error of the results of load measurement when breaking the slings of the domes of parachutes of 1973 production was ± 5.0%, for parachutes of 1974 production - ± 3.8%. The relative error of the results of measuring the elongation at the break of the slings of the domes of parachutes of 1973 manufacture was ± 2.9%, for parachutes of 1974 manufacture ± 3.3%. Given that the measuring instrument has an error of ± 0.29% in the passport, which can be considered systematic, the overall level of uncertainty is acceptable for conventional measurements in engineering. Conclusions. The main factors of accidental errors in the process of measuring the load at break and elongation at break of the slings of the main parachute are external factors due to the state of the cord structure and changes in the internal structure of the polymer.

Dimensional Accuracy and Surface Quality of AZ91D Magnesium Alloy Components after Precision Milling.

This study investigates a precision milling process conducted with the use of conventional end mills and a standard CNC (Computer Numerical Control) machine tool. Milling tests were performed on samples of AZ91D magnesium alloy using TiB2- and TiAlN-coated three-edge end mills measuring 16 mm in diameter. The following technological parameters were made variable: cutting speed, feed per tooth and axial depth of cut. The effects of precision milling were evaluated by analysing the scatter of dimension values obtained in successive tool passes. In addition to that, deviations from the assumed nominal depth as well as obtained ranges of dimension varation were analysed. The study also examined surface quality obtained in the precision milling process, based on the basic surface roughness parameters: Ra, Rz and RSm. Results have confirmed that the use of conventional cutting tools and a standard CNC machine tool makes it possible to manufacture components characterized by relatively small scatter of dimension values and high accuracy classes. Additionally, the results have shown that the type of tool coating and variations of individual technological parameters exert impact on the dimensional accuracy and surface quality obtained.

The use of machine learning for inverse uncertainty quantification in TRACE code based on Marviken experiment

Inverse Uncertainty Quantification (IUQ) methods are gaining recognition in the application of Best Estimate Plus Uncertainty methodologies. Typically, the code input parameters constituted the sources of uncertainties that cannot be estimated other than by user expertise. The IUQ methods aim at providing a more robust and scientific estimation of the distributions of those parameters. In this paper, an approach has been proposed to use machine learning to quantify the uncertainty of critical flow parameters available in the TRACE code.Serving as the means to the ultimate goal of IUQ, the machine learning algorithm has also been utilized in the qualitative assessment of discrepancies between the experiment and calculations. First, a set of Monte Carlo calculations were performed for selected Marviken Critical Flow Tests with permutated values of input parameters of TRACE code. Then, utilizing a supervised machine learning model and a set of features describing the mass flow progression, a Random Forest classifier was used to assign the results to one of the defined classes of prediction accuracy. This analysis has been done using two different training datasets to present the influence of the training data selection on the classification.The machine learning classification resulted in creating a class for which the results with the best fit to the experiment were collected. Derivation of this class created an opportunity to propose ranges and probability distribution functions for CHM12 and CHM22 TRACE internal variables, which is a goal for IUQ methods. Lognormal distribution has been proposed for CHM12 with a mode equal to 0.87, while normal distribution was proposed for CHM22 with a mean equal to 0.9. Variables C1RC2 and C2RC2 proved to be uninfluential on the results. The PDFs for CHM12 and CHM22 have been verified on all 26 Marviken tests. The article proposes a method that can be used in best-estimate analyses to obtain reliable distributions of input variables.

Algorithm for determining the unbalances of continuous mixers rotors

The paper presents a design model of a continuous mixer, which employs working shafts with kneading and scraping blades as the equivalent rotors. The rotors are represented in the orthogonal system x, y, z. An algorithm for reducing a three-dimensional system to flat ones using three-dimensional simulation is proposed to simplify further calculations. The inertia and the mass moments of the rotors’ structural elements were determined for the specific parameters of the parts obtained by blanks casting taking into account the accuracy classes. The conducted research allowed developing recommendations for choosing rational methods for manufacturing parts of continuous mixers and optimal parameters for the operation of the mixer.

Using a balanced scorecard to identify opportunities to improve code review effectiveness: an industrial experience report

Peer code review is a widely adopted software engineering practice to ensure code quality and ensure software reliability in both the commercial and open-source software projects. Due to the large effort overhead associated with practicing code reviews, project managers often wonder, if their code reviews are effective and if there are improvement opportunities in that respect. Since project managers at Samsung Research Bangladesh (SRBD) were also intrigued by these questions, this research developed, deployed, and evaluated a production-ready solution using the Balanced SCorecard (BSC) strategy that SRBD managers can use in their day-to-day management to monitor individual developer’s, a particular project’s or the entire organization’s code review effectiveness. Following the four-step framework of the BSC strategy, we– 1) defined the operation goals of this research, 2) defined a set of metrics to measure the effectiveness of code reviews, 3) developed an automated mechanism to measure those metrics, and 4) developed and evaluated a monitoring application to inform the key stakeholders. Our automated model to identify useful code reviews achieves 7.88% and 14.39% improvement in terms of accuracy and minority class F1 score respectively over the models proposed in prior studies. It also outperforms human evaluators from SRBD, that the model replaces, by a margin of 25.32% and 23.84% respectively in terms of accuracy and minority class F1 score. In our post-deployment survey, SRBD developers and managers indicated that they found our solution as useful and it provided them with important insights to help their decision makings.

Post-Market Surveillance of a Blood Glucose Test Strip Demonstrates No Evidence of Interference on Clinical Accuracy in a Large Cohort of People with Type 1 or Type 2 Diabetes.

Regulations and industry guidance relating to testing for interference in blood glucose monitoring (BGM) systems continue to focus on in vitro laboratory bench tests. Post-market surveillance (PMS) in a clinical setting allows for BGM accuracy assessments to evaluate the impact of real-world exposure to polypharmacy in people with diabetes. This study evaluated the OneTouch Select Plus® BGM test-strip accuracy with respect to polypharmacy using a clinical registry dataset. Medication profiles were analysed for 1023 subjects (425 with type 1 (T1D) and 598 with type 2 diabetes (T2D)) attending 3 UK hospitals. Blood samples were analysed to determine clinical accuracy of the BGM test-strip against a laboratory comparator. 538 different medications (48 diabetes and 490 non-diabetes) were recorded across the 1023 subjects. Patients took on average 6.9 (n = 1-36) individual medications and 4.1 (n = 1-13) unique medication classes. Clinical accuracy to EN ISO 15197:2015 criteria were met irrespective of increasing average number of individual medications, categorized from 1-3, 4-6, 7-9, 10-12 and >12 taken per subject (97.7%, 97.7%, 97.8%, 97.8%, and 98.4%, respectively). Clinical accuracy criteria were met across 15 classes of medication using the combined dataset (97.9%; 29784/30433). Surveillance Error Grid (SEG) analysis showed 98.7% (29959/30368) of readings presented no clinical risk. No individual class or combination of medication classes impacted clinical accuracy of the BGM test-strip. Clinical performance for the test strip under assessment demonstrated no evidence of interference from over 500 prescription medications, with clinical accuracy maintained across a range of polypharmacy conditions in people with diabetes.

Джерело живлення вимірювальних датчиків при виконанні експериментальних досліджень електротепломеханічної системи

The main part of scientific research is the results of the experiment, because they make it possible to establish the existing dependencies of the course of processes on a real object, confirm theoretical calculations and a mathematical model of an electrothermal-mechanical system. The work is devoted to the issue of experimental research of power supplies for measuring and recording equipment. According to the purpose, a technique was proposed by which experimental studies of the presence of pulses, noise and fluctuations in the output voltage of pulse and transformer power supplies were carried out. The influence of the deviation of the output voltage on the fluctuations of the voltage readings on the measuring and recording equipment has been investigated. Based on the results of experimental studies of power supplies, the proposed technique can be taken as a basis for selecting power supplies in accordance with the requirements for the required accuracy of reading indicators from the measuring equipment in accordance with their accuracy class, within the total error permissible for this type of experiment. A power source for measuring and recording equipment was selected for experimental studies of an electrothermal-mechanical system to intensify the process of methane formation in a biogas reactor in order to determine as accurately as possible the energy costs for biogas production, due to the fact that the process of producing biogas is long, therefore, a large error in determining energy costs affects an increase in actual energy costs in production in relation to the calculated and experimental data. The practical value of the work lies in the fact that the use of power supplies with a lower ripple of the output voltage in experiments will reduce the processing time of the obtained data arrays, increase the efficiency of the experiment and the accuracy of the revealed dependencies. The methodology presented in the work also makes it possible to more efficiently use financial resources for the purchase of devices in the preparation and conduct of scientific and experimental research. Keywords: power supply, voltage pulse, accuracy, scientific research, experiment, PeakTech

Use of High Performance Liquid Chromatography in the Analysis of a New Substance VMA-10-18

Introduction. Quinazoline derivatives have a wide range of pharmacological properties, which makes this group quite unique among other classes of heterocyclic compounds. Substance VMA-10-18, which has cerebrovasodilating, antidepressant, anxiolytic and nootropic properties, may become a promising new drug. In this regard, an urgent task is to develop methods for standardizing this substance.Aim. Development of a method for the quantitation of related impurities of a new biologically active substance VMA-10-18 (Quinazophene) by HPLC with subsequent statistical processing of the results.Materials and methods. To develop the conditions for chromatographic analysis, was used a highly purified substance 3-[2-(4-methoxyphenylamino)-2-oxoethyl]-quinazolin-4(3H)-one, as well as its related impurities: impurity I (unsubstituted quinazolin-4(3H)-one) and impurity II (4-methoxychloroacetanilide). Test solutions were prepared using volumetric glassware of accuracy class 1. Ethyl alcohol 95 % was used as a solvent. Chromatography was performed using a Dionex UltiMate 3000 system (Dionex, United States) with a spectrophotometric detector. The analysis was carried out at a wavelength of 231 nm. Data collection and processing was carried out using the Chromeleon v.7 system. A mixture of acetonitrile and orthophosphoric acid was used as a mobile phase. The analysis was performed in an isocratic mode. The validation of the developed method was carried out taking into account the requirements of the State Pharmacopeia of Russian Federation XIV edition and the recommendations of the ICH.Results and discussion. The optimal conditions for chromatography of the VMA-10-18 substance and its impurities have been developed. It was found that for a clear separation of the peaks of the substance and impurities among themselves, the mobile phase should contain acetonitrile and orthophosphoric acid in a ratio of 80 : 20. The specificity of the method was determined by chromatography of ethyl alcohol in order to exclude its influence on the analysis results. The linearity and correctness of the method were determined at 7 levels of concentration of impurities of the substance. The correlation coefficient has exceeded 0.99. Also, the free term of the linear dependence equation (a) for both impurities was less than its confidence interval (Δа), which proves the absence of a systematic error of the method. When determining the "Convergence" indicator, the calculated relative standard deviation did not exceed 2 %. When determining the intralaboratory precision, Student's t-test and Fisher's F-test were calculated. Both indicators met the stated requirements.Conclusion. A method for the quantitative determination of impurities in the VMA-10-18 substance by HPLC has been developed and validated.

Mechatronic Control Devices for a Modern Ship’s Magnetic Compass

One of the disadvantages of existing main magnetic compasses (МС) is the presence in their readings of an error from pitching due to the influence of centripetal and tangential accelerations when the MC is placed at a certain distance from the center rocking of the ship. This error can be unacceptably large, especially when using the compass in high latitude environments. This effect can be compensated by using a gyroscopic angular rate sensor (ARS), which measures the angular yaw rate of the ship. The work is devoted to the results of research and simulation of two correction system, which is introduced into the measuring circuit of the MC. Each of the correction systems presented in this work can be considered as mechatronic control device for a modern MC, one of them is positional, and the other is according to the angular yaw rate of the ship. The paper shows the advantages and disadvantages each of systems. So, a feature of the positional correction system is the need to use ARS of a tactical accuracy class (for example, a fiber-optic gyroscope). At the same time, the yaw rate correction system makes it possible to use a cheap micromechanical gyroscope (MMG). Despite the use ARS of various accuracy classes, both proposed correction systems allow achieving similar results, which leads to an obvious conclusion about the advisability of using the correction system with MMG, which allows to significantly reduce the cost of the MC, as well as to reduce its weight and dimensions.