Actual Test Results Research Articles

Electrical energy storage systems for increasing technical and economical characteristics of gas engine power plants

Developing of new technologies such as electrical energy storage systems (EESS) opens new ways to increasing efficiency, decreasing exhaust waste and fuel consumption in traditional fossil fuels power station. This paper contains actual testing results of electrical energy storage system based on lithium-ion technology working with gas engine generator and altering load power. EESS parameters: rated power 100 kVA, rated capacity 153 kWh. As is known, gas generators are sensitive to changes in load power, obtained results show the effectiveness of the usage EESS to supply sustainability of generators in high amplitude and frequency altering load power environment. These results achieved through the ability of the developed converter and control strategy to compensate rapid deviations of the load power. In additional, in control system realized others common functionality: active power limitation, voltage and frequency control, reactive power control, power factor control and others. With the usage EESS, the nominal power of plane station should be lower than without EESS.

Identification of Power Quality Disturbances Based on Sample Entropy and Weighted Optimization Random Forest

With the increasing number of non-linear loads and impact loads in the actual power grid, power quality problems are becoming more and more serious. Accurate and rapid identification of power quality disturbance signals is of great significance for improving the power quality and ensuring stable operation of the power grid. For this reason, this paper proposes a multi-resolution analysis of wavelet transform and a combination of sample entropy to extract the characteristics of power quality disturbance signals. The classification effect is better than the initial samples. The weighted optimization random forest classifier is used to classify the features, which reduces the error caused by the mode voting method of the random forest. The simulation and actual test results show that the power quality disturbances detection algorithm based on sample entropy and weighted optimization random forest has better classification accuracy than the decision tree, extreme random tree and traditional random forest.

Research on joint simulation technology of fire dynamics and servo control of self-propelled antiaircraft gun during moving

Taking self-propelled anti-aircraft gun as the research object, this paper presents a joint simulation method of shooting dynamics and servo control during the course of self-propelled anti-aircraft gun. Aiming at the matching between structural parameters and servo control parameters of self-propelled anti-aircraft gun, an evaluation and optimization design method is proposed. The platform of the joint simulation system of dynamics and servo control is mainly composed of road-body-turret dynamics model, fire control module, elevation control compensation module, azimuth control compensation module and motor module. The control compensation module realizes the control strategy by PID (Proportional-Integral-Differential) control of position and speed loop. The motor module achieves the system control torque output through the current loop and the motor. These modules constitute the joint simulation design model of dynamics and servo control. By comparing the output of the simulation system with the actual firing test results of self-propelled antiaircraft gun, the effectiveness of the method is verified by the firing line error analysis under different experimental conditions. This method can be used to evaluate the tracking accuracy of the system at the design stage, which is helpful to reduce the development cost and shorten the development period.

Remaining useful life (RUL) estimation of electronic solder joints in rugged environment under random vibration

The remaining useful life (RUL) of electronic modules under the influence of rugged random-vibration and operational conditions is investigated in this paper. The effects of storage conditions and soft failures, caused by the vibrations to solder joints of a printed circuit board (PCB) are analyzed. The RUL is estimated with the help of vibration testing and finite element analysis techniques. Keeping in view the standard and working environmental conditions, the PCB of a power distribution module is subjected to random and sine vibrations. Besides the significance of fatigue damage and RUL estimation of solder joints, caused by storage or operation for a period of five years has not been addressed in existing literature so far. The current study performs the modal analysis to find the natural frequencies, mode shapes, and participation factor ratios of a PCB and its components. These natural frequencies are subsequently verified via comparison with experimental sine sweep results. A random vibration test over the frequency range from 10 Hz to 2000 Hz is also applied for recording the time-to-failure ratio of the PCB. Moreover, the spectrum analysis is performed using the commercial ANSYS software, to assess the acceleration response and the stress power spectral density (PSD) of the critical solder joints. The stress PSD is then used to estimate the random vibration fatigue damage of the solder joint. The calculated fatigue life, based on the modified Miner's rule and the Basquin power-law conform to the actual random vibration testing results.

Analysis of current characteristics of corona discharge in high voltage transmission

In order to study the current characteristics of corona discharge in high voltage transmission, the time-domain characteristics and volt ampere characteristics of corona discharge under different high voltage are tested and analyzed. The actual test results show that: in the whole process of corona discharge, with the increase of inter electrode voltage, the frequency of pulse current increases, and the duration of current remains unchanged; negative corona discharge is more likely to occur, and with the increase of voltage, the average current growth rate is higher than positive corona discharge. Under the same interelectrode voltage, the negative corona current is stronger than the positive one. The nonlinearity of equivalent resistance between positive corona discharge electrodes is stronger than that of negative corona discharge.

Practical Implementation of Passivity-Based Robust Switching Posture Control of Wheeled Mobile Robots With Model Uncertainty

Our previous study presented the theoretical work for a passivity-based robust switching posture control of wheeled mobile robots (WMRs) with model uncertainty and performed the numerical simulations to show its effectiveness. In this regard, this paper validated the proposed technique based on actually fabricated WMR under the various initial conditions. The actual test results have proven that the posture stabilization of the WMR can be successfully accomplished via the proposed control strategy. In addition, it is found that the action of robust model uncertainty compensation reduces the time of the entire stabilization process and guarantees the strict decrease of navigation energy. This work will become a valuable asset for those who wish to practically implement the posture stabilization of WMR based on the passivity-based robust switching control laws totally designed by the 2nd order Largrangian dynamics instead of the 1st order kinematics based approach.

Aesthetic, functional and physical features of glulam in building architecture

The main purpose of this research is to prove the efficiency of glulam to meet various architectural needs. The three features of glulam such as: plasticity and aesthetic value, functional efficiency, supporting properties and resistance to extreme conditions, are compared with the same features of concrete and steel, the most widely used materials nowadays. The methods are based upon actual test results and practical experience in creating glulam constructions. The research shows that plasticity of glulam allows to create complex curved surfaces and its surface and texture clearly demonstrate the unique aesthetic features of the elements made of this material. Glulam can also be efficiently used to create various space morphotypes such as compact rooms, linear vertical and horizontal space, hall space, space with a complex spatial configuration. It is also proved that glulam strength expressed in Constructive Quality Ratio (CQR) surpasses steel and concrete in supporting ability and its durability also exceeds steel structures durability and is comparable to concrete.

A Novel Multiface Recognition Method With Short Training Time and Lightweight Based on ABASNet and H-Softmax

In order to solve the problem of low face recognition accuracy of traditional algorithms and excessive long training time in deep learning methods, a novel lightweight and short training time multiface recognition method is proposed in this paper. Firstly, an extraction model of facial feature vectors is established based on local binary mode and principal component analysis. Secondly, the beetle antennae search algorithm (BAS) is optimized using adaptive factors, and the ABAS algorithm is proposed. This paper uses the ABAS algorithm to optimize the initial threshold of the neural network and proposes the ABASNet method. Thirdly, ABASNet method is combined with the face features extracted by the face feature vector extraction model to be used for multi-face classification tasks. Finally, H-softmax (hierarchical softmax) is used to replace softmax in neural networks. By reducing the amount of calculation in the process of multi-category face classification, the training time of the ABASNet network is reduced. Through ablation experiments and comparative experiments with various methods such as IKDA + PNN algorithm and PCANet algorithm, to verify the accuracy, robustness and short training time of the ABASNet method. Among them, the maximum accuracy of the method in the ORL face dataset, ExtYaleB face dataset and FERET face dataset is 99.35%, 99.54% and 99.18% respectively. In addition, actual test results indicate that the training time and recognition time of the method in this paper are 21 seconds and 0.06 seconds respectively, which has demonstrated the lightweight and real-time performance of the proposed method. At the same time, more test results show that the proposed ABASNet method can also be implemented in embedded devices and other classification tasks.

Measuring and estimating shear force of one stapled and one-row multi stapled wood joints

Since staple is the most used fastener in furniture frame, its holding capacity in solid wood joints is need to be known. Therefore, lateral shear resistance capacity of one stapled and one-row multi stapled joints con-structed from Scotch pine, alder, and beech were investigated. Results showed that the joints constructed from beech with a density of 540 kg/m3 yielded 4893 N, the 4 staples joints constructed from alder with a density of 510 kg/m3 yielded 4487 N, and the 4 staples joints constructed from Scotch pine with a density of 450 kg/m3yielded 3498 N. Three and two staples connected joints also indicated decreasing trend when changing wood from beech to alder and Scotch pine. Results also indicated that increasing number of staple from 2 to 4 in one-row joints increased force of the joints. Two prediction equations were derived to predict the shear of one-row multi stapled wood joints. Both equations yielded remarkable results compared to actual laboratory test results

Research on Music Visualization Based on Graphic Images and Mathematical Statistics

Music visualization can present music information through the visual way of graphic images, which is helpful to improve the accuracy and effectiveness of music information communication. In view of the shortcomings in the current music visualization field, this paper combines K-means clustering, fusion decision tree and other mathematical statistical methods on the basis of music graphic images to construct a music visualization model based on graphic images and mathematical statistics. First, the application principles of Schlieren imaging and laser Doppler imaging in the visualization of music graphic images are described. Secondly, on the basis of music graphic images, K-means clustering method is used to perform cluster analysis on music visualization information. Finally, through the fusion decision tree method, the classification of music visual information is studied. The actual case analysis and performance test results show the superiority of the music visualization method based on graphic images and mathematical statistics. This method can provide a scientific reference model and basis for the modern music industry to establish new visualization systems using graphics, images and mathematical statistics.

Research on the Tower Pole Tilt Mechanism and Risk Assessment Technology Based on BeiDou reverse network RTK

In order to solve the problems of inaccurate and untimely monitoring and high false alarm rate in the current monitoring of the tower pole tilt attitude, this paper proposes a technology for monitoring the tower pole tilt attitude based on RTK technology of Beidou reverse network. This method uses reverse network RTK differential positioning algorithm, which can improve the positioning accuracy of the low-cost Beidou/GNSS positioning terminal and make the positioning accuracy of the tower pole tilt monitoring reach the millimeter level. In this paper, the tilt attitude information of the transmission line tower is measured and calculated by using the height and position information of the transmission line tower, and then the risk assessment is carried out, so as to control the tilt attitude and assess the risk of the transmission line tower. The actual test results show that the method can obtain the information of the tilt attitude of transmission tower pole accurately and reliably, and can be used to evaluate it, which meets the requirements of intelligent, accurate and digital management.

Performance of a Water Ionizing Device That Uses Carbon Nanotube for Treating Particulates and Other Pollutants Found in Drinking Water

The study was undertaken to verify performance of a commercially available water ionizing device that uses carbon nanotube to treat particulates and other pollutants found in drinking water. Two (2) deep well stations belonging to a local water concessionaire known to have quality issues were considered. Water samples were collected and analyzed for physicochemical, bacteriological and organic parameters such as Total Alkalinity, Bicarbonates, Acidity, Free CO2, Chlorine, Total Hardness, Calcium Hardness, Ca, Mg, pH, Residual Chlorine, Turbidity, TDS, color, Fe, Mn, Total coliform, HPC count and Dieldrin. The device’s performance efficiency in treating the pollutants was calculated. The products’ claims were verified thru actual test results. Results indicate that the device is not working as it should. It has very minimal color, Fe and Mn removal – contrary to the product claims and has zero dieldrin treatment capability. On the brighter side, the device reduced total coliform by an average of 59.67% although HPC count spiked by an average of 1,210%. The obtained results will be useful in optioneering for future treatment technologies for the water concessionaire or similar waterworks.

Decisional conflict among adolescents and parents making decisions about genomic sequencing results.

Genomic testing of adolescents is increasing yet engaging them in decision-making is not routine. We assessed decisional conflict in adolescents and a parent making independent decisions about actual genomic testing results and factors that influenced their choices. We enrolled 163 dyads consisting of an adolescent (13-17 years) not selected based on a specific clinical indication and one parent. After independently choosing categories of conditions to learn for the adolescent, participants completed the validated Decisional Conflict Scale and a survey assessing factors influencing their respective choices. Adolescents had higher decisional conflict scores than parents (15.6 [IQR:4.7-25.6] vs 9.4 [IQR:1.6-21.9]; P = .0007). Adolescents with clinically significant decisional conflict were less likely to choose to learn all results than adolescents with lower decisional conflict (19.6% vs 80.4%; P < .0001) and less likely to report their choices were influenced by actionability of results (33.3% vs 18.9%; P = .044) and feeling confident they can deal with the results (71.2% vs 91.9%; P = .0005). Our findings suggest higher decisional conflict in adolescents may influence the type and amount of genomic results they wish to learn. Additional research assessing decisional conflict and factors influencing testing choices among adolescents in clinical settings are required.

Discrete element simulation and parameter selection about triaxial test of cohesive soil containing calcareous nodules

Based on the discrete element method, the relationship between the microscopic parameters and the actual macroscopic parameters is introduced. In this paper the method of calculating the corresponding microscopic parameters of cohesive soil containing calcareous nodules is discussed, and the numerical model is established by using the solved parameter results. Numerical simulation results show that: the numerical model of cohesive soil containing calcareous nodules is basically consistent with the stress-strain curve of the actual triaxial test results, and has a high similarity. On this basis, the mechanism of the effect of calcareous nodules on the mechanical properties of soil on the mesoscale scale can be further discussed.

COMPUTER MODELING OF ACCURACY CHARACTERISTICS OF STRAPDOWN INERTIAL NAVIGATION SYSTEM

Context. The problem of correction for operation of strapdown inertial navigation system used for unmanned aerial vehicle is urgent because of further increased requirements to autonomous flight in blackout zones. The object of the study was to simulate the accuracy characteristics of strapdown inertial navigation system based on known (or given) instrument errors of its sensors. Objective. The goal of the work is to develop a mathematical and computer model of the strapdown inertial navigation system and estimate its accuracy characteristics based on given values of sensor errors. Method. The mathematical and computer models of the strapdown inertial navigation system based on slow, medium and fast cycles are developed. For the simulation of accuracy characteristics, the strapdown inertial navigation system is represented as a set of dynamic and kinematic equations in local tangent plane coordinate system with the Earth’s model taking into account components of gravity acceleration. The models of sensors are developed based on characteristics of low-cost microelectromechanical sensors used onboard. Data fusion algorithms were previously considered and include modified Kalman filter or, for some cases, complimentary filter by compensation scheme, but not considered here in details. Direction cosine matrix for strapdown inertial navigation system algorithms is found by Poisson’s method. Results. The developed models have been realized and simulated in MATLAB+Simulink. Initial parameters (errors of the primary information sensors and the flight conditions) during simulation have been varied: medium, high and low latitudes; direction of flight (along and across the meridian; on and against the direction of rotation of the Earth). Conclusions. The developed models and their simulations have been compared with actual testing results of strapdown gyrovertical СБКВ-П2А and confirmed the validity. It allow us to recommend them for use in designing strapdown inertial navigation system of unmanned aerial vehicle, as well as for experimental study of innovative data fusion algorithms for integrated satellite and inertial navigation system.

Application of time-temperature-stress equivalence to nonlinear creep in poly(methyl methacrylate)

The uniaxial tensile creep of a commercial grade poly(methyl methacrylate)(PMMA) was measured for 4000 s at 26 ℃ and at stress levels ranging from 14 MPa to 32 MPa. Considering the influence of physical aging and rheological damage factors on the long-term creep properties of polymers, another time-temperature-stress superposition principle expression was derived. This expression as used to predict the long-term creep mechanical behaviour of PMMA. It was found that a long-term creep compliance master curve considering physical aging and damage agrees well with actual long-term creep test results.

Challenging the WHO Prescribed Sanitary Inspections for Contamination of Tubewells with Handpump

WHO prescribed sanitary inspections constitute useful monitoring tools, besides being effective and economic in identifying drinking sources of water at risk in terms of contamination. In the present case, the contamination risks in potable waters from Tubewells fitted with handpump were evaluated across 9 districts in India. Field inspections were conducted in WHO prescribed format on Three Hundred Twenty Four sources of potable water used by the community for withdrawing drinking water to evaluate occurrence of contamination risk. The theoretical risk thus assessed was then compared with actual test results of biological testing in the laboratory for assessment of Coliform bacteria using a standard MPN test. The results of the study indicate that WHO format based sanitary survey results are more stringent than reality, and hence overestimate the risk. The results also indicate that the risk categories are mostly distributed with a majority of risk focused in the middle in the High and Medium risk categories.

A Study on Changes of Window Thermal Performance by Analysis of Physical Test Results in Korea

The interest in zero energy buildings is increasing in South Korea. Zero energy buildings need to save energy by using passive technology. The window performance is important to the thermal insulation of the building. Also, the government regulates the window performance through regulation and standards. However, it is difficult to predict window performance because the components of the window have become complicated due to the various materials used in the glass and frame. Based on window performance standards and regulations, the quality of window performance was managed. In this research, to consider thermal performance in proper window design in South Korea, we confirmed the impact on the thermal performance of the window through various kinds of materials and shapes. The authors also propose a window shape classification and frame calculation method based on actual test results. The authors analyzed the thermal performance data of the windows provided by the Korea Energy Agency and confirmed the change in the thermal performance of the windows by year and by frame material. The average U-value of the window decreased from 2012 to 2015 and maintained similar values until 2017. In 2018, this value was decreased to comply. Also, the authors confirmed the U-value of the windows through actual physical experiments and confirmed the change in thermal performance by the construction of the windows based on the results. The results show, in the case of aluminum windows, the U-value corresponding to Grade 3 (1.4–2.1 W/m2·K) was as high as about 60%. Regarding the analyzed results of the U-values of PVC windows, Grade 3 (U-value of 1.4–2.1 W/m2·K) accounted for about 35%, and Grade 2 (U-value of 1.0–1.4 W/m2·K) for about 29%. This paper also confirmed that the frame U-value of the PVC windows is lower than the frame U-value of the aluminum windows. Therefore, the authors proposed the performance index of the glazing part in PVC and aluminum window design. The results of this research can be used as basic data to identify problems in the method of determining the performance of windows in Korea.

Assessment of structural behavior of torque converter dampener

A Torque Converter Dampener is a primary component for transmittal of power between the Engine and the Transmission. It comprises of three major components – driving cage plates, driven cage plates and set of springs. Being a spring based system, it provides a smooth conversion of torque from engine to the driveline. When the vehicle performs a gearshift, these springs damp the driveline oscillations and they get locked when the vehicle runs at a higher speed. A Torque Converter Dampener assembly is typically subjected to high torque and centrifugal loading and sometimes, there is a chance of breaking of the springs under operating loading conditions. This paper explains detailed method of analyzing Torque Converter Dampener using Finite Element Analysis. Cage plates and springs are modeled accurately with interactions and boundary conditions properly defined similar to actual hardware, in order to capture the physics of the system. As the problem is highly complex in nature, material non linearity, temperature effect and effect of dynamic fluid pressure are not taken into consideration. The analysis process takes care of the spring’s installation followed by applying centrifugal force and torque in alternating sequence. Similar method is repeated for different spring orientation to find out the worst case model and loading sequence. High stress locations on springs and Driving/Driven cage plates are identified and correlated with the actual hardware test results.

Blind Dereverberation Wideband Multi-Source 2-D DOA Estimation Method Based on Single Channel Nonnegative Matrix Factorization

There are many algorithms for DOA estimation based on blind source separation (BSS), which assumes that each sensor perceives a linear instantaneous mixed narrowband signal with known number of sources in noise-free or low noise environments. However, in practical applications, the number of mixed signal sources is unknown, and the perceived signals are often acquired in strong noise and reverberant environments. This paper proposes a novel noise reduction single-channel nonnegative matrix factorization deconvolution (NRSNMFD) wideband multi-source 2-D DOA estimation algorithm. Firstly, LMS adaptive filtering is used to remove the noise of the observation signal. Secondly, the single channel observation signal is decomposed into multi-channel signals composed of multiple intrinsic mode functions (IMFs) by empirical mode decomposition (EMD). The number of signal sources is estimated and the determined signals are reconstructed. Thirdly, the dereverberation of the signals are realized by NMFD method. The GCC-PHAT method is used to estimate the delay of the signal source. Finally, signal source location is realized based on the delay. The simulation and actual test results show that the proposed algorithm can estimate 2-D DOA with high accuracy under noise and reverberation environment, providing a new method for engineering application.