An integrated approach on verification of signatures using multiple classifiers (SVM and Decision Tree): A multi-classification approach

A signature is a handwritten representation that is commonly used to validate and recognize the writer individually. An automated verification system is mandatory to verify the identity. The signature essentially displays a variety of dynamics and the static characteristics differ with time and place. Many scientists have already found different algorithms to boost the signature verification system function extraction point. The paper is aimed at multiplying two different ways to solve the problem in digital, manual, or some other means of verifying signatures. The various characteristics of the signature were found through the most adequately implemented methods of machine learning (support vector and decision tree). In addition, the characteristics were listed after measuring the effects. An experiment was performed in various language databases. More precision was obtained from the feature.

MATH MODEL OF A DIRECT CURRENT MOTOR FOR STEERING ACTUATOR OF A LIQUID-PROPELLANT ENGINE

The paper presents the results of development of a math model for a direct current motor of a liquid-propellant engine steering actuator In accordance with the electrical machine theory, the math model of the motor uses a single electromagnetic coefficient. It is shown that the motor math model accuracy can be improved through the use, instead of a single electromagnetic coefficient, of two different coefficients of the math model: Electromechanical velocity coupling coefficient and torque curve coefficient. Elaborated and proposed are methods for identifying parameters of a math model of a dc motor that has natural and artificial static characteristics, which include determining its experimental static characteristics, calculating the values of static characteristics parameters using the linear regression method and calculating the values of the electric motor math model parameters using the proposed formulas. Key words: direct current electric motor, math model, parameter identification method.

Two Wire Sensor for Measuring the Velocity of Non-Isothermal Flows

Changes in the temperature of the medium significantly affect the static characteristics of hot-wire anemometry measuring wires, which causes errors in the results of flow velocity measurements. High temperatures of the medium make it necessary to additionally heat the sensor to even higher temperatures, which may lead to its damage due to wire burnout. The article proposes a solution to the problem of measuring the flow velocity in conditions of non-stationary temperatures with the use of the method of cross-correlation of signals from two-wire resistance thermometers. The main assumptions of the method and its experimental verification were presented.

Developing and Investigating the Analyzers of Kinematic Viscosity and Density of Petroleum Products on Throttle Bridge Transducers

Measuring the viscosity and density of petroleum products is important for their proper production, transportation and application. Viscosity and density are the main parameters determining the composition and structure of petroleum products. Therefore, in the industry, to control the quality of petroleum products during various technological processes, automatic and non-automatic devices are used for their measurement. The accuracy of measuring the viscosity and density of petroleum products is an important factor. The authors analyzed different methods of measuring the viscosity and density of petroleum products and synthesized three versions of throttle bridge transducers. These versions implement differential measurement methods and have different numbers of laminar and turbulent throttles. The authors obtained new equations of static conversion functions by channels of measuring the kinematic viscosity and density of petroleum products of the proposed throttle bridge transducers. The authors developed a block diagram and designed measuring equipment to study experimentally the static characteristics of the throttle bridge transducers. The authors determined that the maximal relative deviations of the results of experimental studies from numerical calculations of a static conversion factor by channels of kinematic viscosity and density were 5.88% and 8.76%, respectively. The authors developed two versions of automatic devices for measuring the kinematic viscosity and density of petroleum products based on the proposed throttle bridge transducers. The first version is an automatic analyzer with tracking astatic balancing. The second version is an automatic analyzer with deployment balancing. The authors developed constructions of both versions of automatic analyzers and obtained the results of experimental measuring of the kinematic viscosity and density of petroleum products in different ranges.

Lithium-ion power battery grouping: A multisource data fusion based clustering approach and distributed deployment

Consistence of lithium-ion power battery significantly affects the life and safety of battery modules and packs. To improve the consistence, battery grouping is employed, assembling batteries with similar electrochemical characteristics to make up modules and packs. Therefore, grouping process boils down to unsupervised clustering problem. Current used grouping approaches include two aspects, static characteristics based and dynamic based. However, there are three problems. First, the common problem is underutilization of multi-source data. Second, for the static characteristics based, there is grouping failure over time. Third, for the dynamic characteristics based, there is high computational complexity. To solve these problems, we propose a distributed multisource data fusion based battery grouping approach. The proposed approach designs an effective network structure for multisource data fusion, and a self supervised scheme for feature extraction from both static and dynamic multisource data. We apply our approach on real battery modules and test state of health (SOH) after charging-discharging cycles. Experimental results indicate that the proposed scheme can increase SOH of modules by 3.89%, and reduce the inconsistence by 68.4%. Meanwhile, with the distributed deployment the time cost is reduced by 87.9% than the centralized scheme.

Monolithic Si-Based AlGaN/GaN MIS-HEMTs Comparator and Its High Temperature Characteristics

Monolithic GaN High Electron Mobility Transistor (HEMT)-integrated circuits are a promising application of wide band-gap materials. To date, most GaN-based devices behave as NMOS-like transistors. As only NMOS GaN HEMT is currently commercially available, its control circuit requires special design if monolithic integration is desired. This article analyzes the schematics of a GaN-based comparator, and three comparator structures are compared through ADS simulation. The optimal structure with the bootstrapped technique is fabricated based on AlGaN/GaN Metal–Insulator–Semiconductor (MIS) HEMT with the recessed gate method. The comparator has excellent static characteristics when the reference voltage increases from 3 V to 8 V. Dynamic waveforms from 10 kHz to 1 MHz are also obtained. High-temperature tests from 25 °C to 250 °C are applied upon both DC and AC characteristics. The mechanisms of instability issues are explained under dynamic working condition. The results prove that the comparator can be used in the state-of-art mixed-signal circuits, demonstrating the potential for the monolithic all-GaN integrated circuits.

Statistical Analysis on the Static Characteristics of the Geosynthetic Encased Stone Column

The geosynthetic encased stone column is made of stone column encased with geosynthetic encasement. The geosynthetic encased stone column is often used for foundation treatment of roadbeds, dams, buildings and other structures. At present, a series of new developments have been made in the researches of bearing capacity, stress concentration ratio and deformation of the geosynthetic encased stone column. This paper statistically analyzes the three important static characteristics of the geosynthetic encased stone column.

Diagnostics of the Excessive Wear of the Machine on a Model of Developmental, Progressive Interactions Between Diagnostic Signals and Rotation Speed Signals

In the machine operating process, there are certain interactions between its operational use and wear. The current wear is increased by the current intensity of operational use, and usable potential is reduced by the current wear rate. In the diagnostic inference process, static characteristics and trajectories of state from the experiment are compared with different matrices determined for various assumed configurations of changes. As a result, the approximated diagnosis is created. This method is not universal. It applies only to the continuous progressive state, more or less increased wear rate of the machine.

Research on Electromagnetic Force of Hybrid Electromagnetic Levitation Needle Driving System

Hybrid electromagnetic levitation drive system is the core of the needle drive structure, and its performance directly determines the size of the needle drive force. According to the initial design results, the simulation model of the needle drive is established in the electromagnetic field simulation software Maxwell, and the influence of the structural parameters of the hybrid electromagnetic drive system:, the material of the iron core, the number of coil turns on its static characteristics is analyzed. The simulation results show that at the same height, when the isolation ring material is aluminum, the time for the permanent magnet needle to rise to the highest position is the shortest.