Conversion Relationship Research Articles

Radiative energy transfer model for high frequency vibration of functionally graded beams in thermal environment

A simple and efficient energy flow model is developed by radiative energy transfer method (RETM) to predict the high frequency vibration response of functionally graded(FG) beams in thermal environment. The Timoshenko beam theory is applied to derive the motion governing equations. Thermal effects are incorporated into the dynamic model through the temperature dependent material properties and the thermal stresses. The wavenumber and group velocity associated with thermal stress are included in the energy governing equation. By introducing the artificial springs to simulate different boundary conditions, the energy conversion relationship of the two waves at boundaries are deduced. The response of FG beam loaded by a high-frequency harmonic force is described by energy density and energy flow intensity. They are composed of energy rays from the real source at the load point and energy rays reflected from the imaginary sources at the boundaries. Numerical simulations are performed in various forms of thermal environments to verify the proposed model. The RETM results are compared with those obtained by the wave propagation approach under different parameters, and good consistencies are observed. Numerical results show that the vibrational energy density of FG beams are affected by thermal effects and can be reduced by optimising the gradient factors.

Determination of the critical fatigue crack length for orthotropic steel decks

Due to the difficulty in determining damage tolerance, orthotropic steel decks (OSD) lack a uniform failure judgment criterion, leading to various fatigue damage evaluation results. One fatigue damage tolerance determination method was proposed based on critical crack length (CCL), which is calculated by log-linear unary functions. Both fatigue tests and numerical simulations were conducted to verify this method. The results indicate stress intensity factor at critical cracks is mainly controlled by the crack length. CCL is affected by stress magnitude and boundary size with a quantitative conversion relationship, and the conversion formulae were established with errors within 15%. The proposed method could reasonably predict CCL with an average error of around 10%. Compared with IIW, this method showed superior applicability in the failure judgment of OSD welded joints.

Synthesis and characterization of N-acyl alkanolamide surfactant from fatty acids and alcohol amines using sodium methoxide catalyst

Surfactant is a substance added to the liquid that improves the spread's properties by weakening the liquid's surface voltage. Surfactants have a molecular structure consisting of hydrophilic groups and hydrophobic groups. Surfactant needs in Indonesia continue to increase along with the development of industries in Indonesia. This study will be synthesized by the N-acyl surfactant alkanolamide using one type of alcohol amine, namely diethanolamine, through a reaction of amidation between fatty acids and using organic solvents tert-amyl alcohol. The catalyst used is a chemical catalyst, namely sodium methoxide. Furthermore, the purpose of this research is to determine the effect of reaction variables and determine the characteristics of the N-acyl alkanolamide surfactant in the form of acidic numbers and spreading numbers. This study showed for lauric acid, palmitate acid, and the best stearate acid at 90 oC reaction temperatures and 2-hour reaction times, while the best succinic acid at 100 oC and a reaction time of 2 hours. The relationship between reaction rate and time is directly proportional; the longer the reaction time, the higher the rate. The conversion relationship with reaction time is directly proportional, where conversion will increase with the increase in reaction time. However, this does not happen to all fatty acids. Due to the increase in reaction time, it will not provide significant results on surfactant products. The relation between the reaction temperature and the conversion acquisition at the time obtained decreased along with the increase in reaction temperatures. The acid numbers in the best conditions in a row are 40.67 for N-palmitoyl diethanolamine, 47.41 for N-lauroyl diethanolamine, 63.11 for N-succinyl diethanolamine, and 22.44 for N-stearoyl diethanolamine. The saponification number in the best conditions in a row is 36.47 for N-palmitoyl diethanolamine, 23.84 for N-lauroyl diethanolamine, 57.50 for N-succinoyl diethanolamine, and 7.01 for N-stearoyl diethanolamine.

Polarization Orientation Method Based on Remote Sensing Image in Cloudy Weather

Autonomous navigation technology is a core technology for intelligent operation, allowing the vehicles to perform tasks without relying on external information, which effectively improves the concealability and reliability. In this paper, based on the previous research on the bionic compound eye, a multi-channel camera array with different polarization degrees was used to construct the atmospheric polarization state measurement platform. A polarization trough threshold segmentation algorithm was applied to study the distribution characteristics and characterization methods of polarization states in atmospheric remote sensing images. In the extracted polarization feature map, the tilting suggestion box was obtained based on the multi-direction window extraction network (similarity-based region proposal networks, SRPN) and the rotation of the suggestion box (Rotation Region of interests, RRoIs). Fast Region Convolutional Neural Networks (RCNN) was used to screen the suggestion boxes, and the Non-maximum suppression (NMS) method was used to select the angle, corresponding to the label of the suggestion box with the highest score, as the solar meridian azimuth in the vehicle coordinate system. The azimuth angle of the solar meridian in the atmospheric coordinate system can be calculated by the astronomical formula. Finally, the final heading angle can be obtained according to the conversion relationship between the coordinate systems. By fitting the measured data based on the least Square method, the slope K value is −1.062, RMSE (Root Mean Square Error) is 6.984, and the determination coefficient R-Square is 0.9968. Experimental results prove the effectiveness of the proposed algorithm, and this study can construct an autonomous navigation algorithm with high concealment and precision, providing a new research idea for the research of autonomous navigation technology.

Application of composite steel slag as subgrade Filler: Performance evaluation and enhancement

The utilization rate of steel slag (SS) in China is much lower than that in developed countries. In this study, water-cooled SS and hot-spray poured SS were analyzed as raw materials. Six kinds of composite SS mixtures with different mixing proportions were then designed, and their properties such as expansion rate, California bearing ratio (CBR) and modulus of resilience were examined. Based on the different mixing proportions of SS, and regression analysis, the conversion relationship between CBR value and subgrade resilience modulus were recommended. Finally, the composite SS subgrade settlement was analyzed by ABAQUS, and the economic benefits were analyzed.

Occurrence and development criteria of coal and gas outbursts based on energy conversion

Coal and gas outbursts are sudden disasters in coal mines, they are major dynamic hazard during coal mining and have to be controlled for mining safety. To further understand the outburst process of coal and gas outbursts, an energy conversion model of coal and gas outbursts are established from the perspective of outburst energy conversion, and the criteria of outburst occurrence and development are determined. The energy conversion relationship and criteria of outburst occurrence and development are analyzed by physical simulation experiments. The results show that the critical threshold of the two groups of experiments is 2600 J. When the outburst potential energy exceeds the critical threshold, the outburst phenomenon occurs. Some of the outburst potential energy is converted into effective outburst potential energy to participate in the outburst work with the outburst process. The effective potential energy conversion rate of the two groups is 52 %-55 %. In the outburst of each experiment with outburst phenomenon, the development criterion values are 1.16–1.20 for experimental group 1, and the values are 3.06–3.75 for experimental group 2. The result indicates that the necessary condition for outburst development is that the outburst effective potential energy is sufficient to overcome the outburst energy consumption. This study will be of great scientific significance for exploring the outburst mechanism.

Laboratory Radiometric Calibration Technique of an Imaging System with Pixel-Level Adaptive Gain.

In a routine optical remote sensor, there is a contradiction between the two requirements of high radiation sensitivity and high dynamic range. Such a problem can be solved by adopting pixel-level adaptive-gain technology, which is carried out by integrating multilevel integrating capacitors into photodetector pixels and multiple nondestructive read-outs of the target charge with a single exposure. There are four gains for any one pixel: high gain (HG), medium gain (MG), low gain (LG), and ultralow gain (ULG). This study analyzes the requirements for laboratory radiometric calibration, and we designed a laboratory calibration scheme for the distinctive imaging method of pixel-level adaptive gain. We obtained calibration coefficients for general application using one gain output, and the switching points of dynamic range and the proportional conversion relationship between adjacent gains as the adaptive-gain output. With these results, on-orbit quantification applications of spectrometers adopting pixel-level automatic gain adaptation technology are guaranteed.

Calibrating Laser Three-Dimensional Projection Systems Using Binocular Vision.

A laser three-dimensional (3D) projection system is an auxiliary system in intelligent manufacturing. It works with a positioning system in practical applications. This study proposes a calibration method for laser 3D projection systems based on binocular vision. The significance of the binocular vision positioning function for the calibration process was analyzed. Two calibration methods for laser 3D projection systems based on the binocular vision positioning function were proposed. One method involves simplified calculation models and another used data to solve the conversion relationship. The experimental calibration of the projection system was performed using data to directly solve the conversion relationship. The experiment demonstrated the simplicity of the proposed calibration method. The calculation time was less under the 3D laser projection system based on binocular vision. Moreover, the mean calibration error was 0.38 mm at a working distance of 1.8-2.2 m.

Interactive effects of polystyrene microplastics and Pb on growth and phytochemicals in mung bean (Vigna radiata L.)

Interaction of different pollutants can aggravate hazards to biotic components in agroecosystems. Microplastics (MPs) are especially needed to be focused on because of their increasing use in life around the globe. We investigated the interactive impacts of polystyrene microplastics (PS-MP) and lead (Pb) on mung bean (Vigna radiata L.). Toxicity of MPs and Pb directly impeded V. radiata attributes. In combination i.e., M2P2 (40 µM Pb + 4.0 mg L-1 MPs) predominantly reduced the shoot root fresh and dry weights. \\ Pb and PS-MP impaired the Rubisco activity and chlorophyll contents. The dose dependent relationship (M2P2) discomposed indole 3-acetic acid by 59.02%. Individual treatments P2 (40 µM Pb) and M2 (4.0 mg L-1 MPs) respectively instigated a decline (44.07% and 27.12%) in IBA, while ABA was elevated. M2 significantly enhanced the contents of Alanine (Ala), Arginine (Arg), Proline (Pro), and glycine (Gly) by 64.11%, 63%, and 54% compared to control. Lysine (Lys) and Valine (Val) presented a converse relationship with other amino acids. Except for control, a gradual decline in yield parameters were observed in individual and combined applications of PS-MP. Proximate composition of carbohydrates, lipids and proteins also reflected a clear decrease in these compounds after combined application of Pb and MPs. Although, individual doses caused a decline in these compounds but effect of combined doses Pb and PS-MP was highly significant. Our results demonstrated the toxicity effect of Pb and MP in V. radiata attributes that is mainly linked with cumulative physiological and metabolic perturbations. These collective negative impacts of different doses of MPs and Pb on V. radiata would certainly pose serious implications for humans.

Degradation characteristics of SBS polymer and its contribution to weathering aging of modified asphalt

Under the weathering environment, the aging behavior of SBS-modified asphalt (SBSMA) is complex, including oxidation of matrix asphalt, degradation of SBS, and disruption of SBS-asphalt interaction. However, most studies on the weathering mechanism of SBS-modified asphalt have mainly been considered from its overall perspective and based on environmental variables. In order to investigate the aging mechanism of SBSMA more clearly, the paper proposes a novel method of SBS-independent weathering to determine the aging behavior of SBS under accelerated weathering conditions and its effect on the performance of modified asphalt. Finally, by correlating its samples (M1) with the behavior of different fresh SBSMA(M2) and weathering aged SBSMA(M3), the SBS effective content equation under weathering conditions and the conversion coefficient between different aging methods were determined. Furthermore, by analyzing the physicochemical properties of SBS polymers before and after weathering and comparing them with the calculated results of SBS effective content within modified asphalt, it is discussed that the swelling effect of SBS under this method differs due to different aging levels, which affects the complete separation of matrix asphalt oxidation and SBS degradation. The macroscopic rheological behavior of samples was evaluated by dynamic shear rheology experiments (DSR), the variation of their chemical component and molecular weight were analyzed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC), and the microscopic network was observed by fluorescence microscopy (FM). The results illustrate that the degradation pattern of weathering SBS follows a single exponential decay function. The SBS effective content decreases to 66.7 %, 50 %, and 33.3 % after accelerated weathering for 5.8 h, 10.5 h, and 14.5 h, respectively. In addition, the conversion relationship between the effective content of SBS under two modes of SBS independent weathering aging and SBSMA weathering aging was established. The effective content of SBS within SBSMA at different service stages and its remaining modification capacity can be reasonably predicted by simple SBS weathering tests.

A Novel Deep Learning Approach to 5G CSI/Geomagnetism/VIO Fused Indoor Localization.

For positioning tasks of mobile robots in indoor environments, the emerging positioning technique based on visual inertial odometry (VIO) is heavily influenced by light and suffers from cumulative errors, which cannot meet the requirements of long-term navigation and positioning. In contrast, positioning techniques that rely on indoor signal sources such as 5G and geomagnetism can provide drift-free global positioning results, but their overall positioning accuracy is low. In order to obtain higher precision and more reliable positioning, this paper proposes a fused 5G/geomagnetism/VIO indoor localization method. Firstly, the error back propagation neural network (BPNN) model is used to fuse 5G and geomagnetic signals to obtain more reliable global positioning results; secondly, the conversion relationship from VIO local positioning results to the global coordinate system is established through the least squares principle; and finally, a fused 5G/geomagnetism/VIO localization system based on the error state extended Kalman filter (ES-EKF) is constructed. The experimental results show that the 5G/geomagnetism fusion localization method overcomes the problem of low accuracy of single sensor localization and can provide more accurate global localization results. Additionally, after fusing the local and global positioning results, the average positioning error of the mobile robot in the two scenarios is 0.61 m and 0.72 m. Compared with the VINS-mono algorithm, our approach improves the average positioning accuracy in indoor environments by 69.0% and 67.2%, respectively.

Structured Student Conversations and their Impact

This action research described how a middle school teacher integrated five discussion protocols including structured controversy, pair communication, triad protocol, personal experience panel, and Socratic seminar into her sixth-grade Language Arts classes. Collected data from three different sources indicated an overall improvement of both student conversational skills and relationship skills when various discussion protocols were implemented in the classroom. Discussions and teacher's reflections were included.

Cross-project utilisation of tunnel boring machine (TBM) construction data: a case study using big data from Yin-Song diversion project in China

ABSTRACT The variation in Tunnelling boring machine (TBM) equipment and geological information of tunnels result in substantial differences in real-time TBM tunnelling data. This variation makes it difficult to apply machine learning models trained by historical engineering data on new projects. To overcome this challenge, a novel data conversion approach from a mechanical analysis perspective has been proposed to normalise TBM tunnelling data, such as cutterhead torque and cutterhead thrust, which help to unify data from different projects under the same framework. Furthermore, the effectiveness of this approach has been verified through analogy analysis and machine learning applications. With the application of these conversion relationships, the machine learning model trained on a completed Yin-Song project with big data (12,501 boring cycles) is applied to the on-going Yin-Chao Water Diversion Project in China with limited data (777 boring cycles) and gives reliable predictions for each performance parameter (with R2 for the cutterhead thrust of 0.81 and R2 for the cutterhead torque of 0.70). This approach enhances the usefulness of TBM intelligence for cross-engineering geophysical prospecting in different geological conditions.

Research progress of lock-in amplifiers

The lock-in amplifier can perform high-precision measurement in both time and amplitude dimensions, so that it becomes a key component of instrumental system for precision measurement and control. This article overviews the concept, technology, and application of phase-locked amplifiers as a guide. It first explains the development and evolution of phase-locked amplifiers of analog, digital, and virtual phase-locked amplifiers, demonstrating their relationship and differences. Then, it classifies phase-locked amplifiers from a mathematical perspective based on the order and type of phase-locked loops. Subsequently, the testing process and metrological calibration progress of the main performance of phase-locked amplifiers, such as amplitude, frequency, and phase noise, are introduced. The conversion relationship between key indicators such as phase noise, time-domain jitter, Allan variance, and the coupling relationship with amplitude noise are discussed. Finally, the application forms and effects of phase-locked amplifiers in the fields of spectral enhancement, impedance analysis, magnetic measurement, microscopic imaging, and space exploration are listed. Through some new applications, the prospects of their transition from scientific instruments to industrial and even civilian products through intelligent computing, precise IoT, and other means are briefly given.

Economic Scheduling of Gaseous-liquid Hydrogen Generation and Storage Plants Considering Complementarity of Multiple Products

The accessible and convenient hydrogen supply is the foundation of successful materialization for hydrogen-powered vehicles (HVs). This paper proposes a novel optimal scheduling model for gaseous-liquid hydrogen generation and storage plants powered by renewable energy to enhance the economic feasibility of investment. The gaseous-liquid hydrogen generation and storage plant can be regarded as an energy hub to supply concurrent service to both the transportation sector and ancillary market. In the proposed model, the power to multi-state hydrogen (P2MH) process is analyzed in detail to model the branched hydrogen flow constraints and the corresponding energy conversion relationship during hydrogen generation, processing, and storage. To model the coupling and interaction of diverse modules in the system, the multi-energy coupling matrix is developed, which can exhibit the mapping of power from the input to the output. Based on this, a multi-product optimal scheduling (MPOS) algorithm considering complementarity of different hydrogen products is further formulated to optimize dispatch factors of the energy hub system to maximize the profit within limited resources. The demand response signals are incorporated in the algorithm to further enhance the operation revenue and the scenario-based method is deployed to consider the uncertainty. The proposed methodology has been fully tested and the results demonstrate that the proposed MPOS can lead to a higher rate of return for the gaseous-liquid hydrogen generation and storage plant.

Study on calculation of transversely isotropic dynamic rock mechanical parameters and conversion model between dynamic parameters and static parameters

The shale oil reservoirs in the Jimsar Sag are strongly heterogeneous. Therefore, it is of practical significance to relate the dynamic elastic stiffness to the static elastic stiffness under the assumption of transverse isotropy. The acquisition of stiffness parameters depends on lab measurements or Sonic Scanner logging. Aiming at the problem that the lab measurements results are limited and discontinuous, the acquisition of special logging data is difficult in the well site, a method using only the conventional well-log data to predict the dynamic elastic stiffnesses of shale is proposed. Inspired by ultrasonic experimental test method, the study simplified the types of tested waves and complemented missing datas. According to the experimental proof, we concluded that: (1) Under the assumption of transverse isotropy, using simplified Thmosen model and velocity conversion relationship can accurately calculate the P-wave and S-wave velocities in the 45° angle direction. (2) Compared with the conventional isotropic algorithm, specify this algorithm can better reflect real mechanical conditions of the formation, and better characterize the variation of mechanical parameters with depth. (3) Effective conversion models between dynamic elastic modulus and static elastic modulus in vertical and horizontal directions were obtained in some areas of Jimsar.

An Improved Calibration Method of Grating Projection Measurement System

In the traditional fringe projection profilometry system, the projector and the camera light center are both spatially virtual points. The spatial position relationships specified in the model are not easy to obtain, leading to inaccurate system parameters and affecting measurement accuracy. This paper proposes a method for solving the system parameters of the fringe projection profilometry system, and the spatial position of the camera and projector can be adjusted in accordance with the obtained calibration parameters. The steps are as follows: First, in accordance with the conversion relationship of the coordinate system in the calibration process, the calculation formula of the vertical distance from the camera light center to the reference plane and the calculation formula of the distance between the projector and the camera light center are given respectively. Secondly, according to the projector calibration principle, the position of the projector light axis perpendicular to the reference plane is gained by comparing the parallel relationship between the reference plane coordinate system and the projector coordinate system’s Z-axis. Then, in order to fulfill the position restriction that the line between the projector light center and the camera light center must be parallel to the reference plane, the camera’s spatial location is adjusted so that the vertical distance between it and the reference plane tends to that between the projector light center and the reference plane. And finally, the three-dimensional (3D) reconstruction of the target object can be finished using the phase height model’s system parameters once the aforementioned position limitations are put into practice. Experimental results demonstrate that the method improves the measurement accuracy, and verifies that it is effective and available in 3D shape measurement.

이청준의 ｢가수(假睡)｣에 나타난 타자 재현 양상 연구

The location of Lee Cheong-joon's “Gasoo” is a time when the historical events of the April 19 democratic revolution and the military coup of May 16 led to hope and frustration with a time difference of less than a year. In this period, individuals are established as others, not as subjects. Lee Cheong-joon reveals the violent nature that occurs in this subject-other relationship by reproducing the other. The reproduction of the other person as an 'anonymous being' in 'Gasoo' is presented through the testimony of the related person. The location where the two main heroes are reproduced as anonymous beings is in the imaginary identification of the witnesses. Lee Cheong-joon reveals the violent situation in which anonymous beings are prohibited from being alone as a whole, with the gloomy atmosphere that dominates the text and the disconnection of communication. And again, as an alternative for the subject to stand alone, it is found in communication in a conversational relationship. This writer's alternative is also revealed in the narrative strategy of “Gasoo”. It avoids violent foundations against others by showing a three-dimensional view of others with a complex and multi-layered narrative situation in the frame format.

A nuclear magnetic resonance based quantification of pore water distribution in unsaturated soils

This study presents a novel approach to quantify the distribution characteristics of pore water in unsaturated soil by using the nuclear magnetic resonance (NMR) technology. The SWCC and NMR T2 curves under different matric suction were measured during the drying process of soil specimen, and a conversion relationship between T2 and pore radius r of was determined. The method using capillary drainage model to simulate soil drying process was feasible, and pores of unsaturated soil were divided into saturated pore, unsaturated pore, and dry pore when the suction exceeded the air entry value. Pore water distribution curve based on T2 well described the distribution characteristics of pore water in unsaturated soil; the quantification of pore water distribution was realized through a defined index named pore water damage potential (Mcp), and a good mathematical relationship was observed between the relative damage degree and the matric suction. By introducing the Mcp, a modified VG model that reflected the characteristics of pore water distribution was in a good quantitative agreement with the experimental observations. The results achieved provided a valuable reference for revealing the internal mechanism of SWCC and establishing mechanical model of unsaturated soil based on pore water distribution.

Geospatial assessment of effect of urbanization on natural drainage in a medium-sized town of Akure, Nigeria

This study examined the state of some urban streams in a tropical environment of Nigeria. It analysed satellite images which include Landsat 5 TM (1986), Landsat 7 ETM (2002), Landsat 8 (2018) imageries with 30 m resolution using ENVI 5.3. The images were classified using a supervised classification algorithm to obtain land use/land cover themes for spatial analysis in the ArcMap 10.3 environment while drainage systems were extracted from the topographical map of 1966 of the study area. Result showed a total drainage network of about 90, covering a total distance of 307 km in 1986, which decreased to 226.87 km in 2018. Within the study period (32 years), more streams experienced decrease in lengths (231.44 km) than those whose lengths increased (129.85 km). While 136.92 km stream lengths were lost within the study period, about 25.45 km stream length were rejuvenated. Urban landuse correspondingly increased from 18.8% in 1986 to 52.2% in 2018, suggesting that a converse relationship between increase in urban land cover and dearth of streams in the area. The study provides information regarding the current status of the drainage system for effective planning and management of flood hazards in the study area. It also canvasses for adequate provision and maintenance of setbacks to streams and rivers under the supervision of the Development Control Department (DCD) of the Ondo State Ministry of Urban Development and Regional Planning (OSMUD&RP).