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Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, in order to reduce the energy leakage caused by the discretized representation in sparse channel estimation for Orthogonal Frequency Division Multiplexing (OFDM) systems, we systematically have analyzed the optimal locations of atoms with discrete delays for each path reconstruction from the perspective of linear fitting theory. Then, we have investigated the adverse effects of the non-ideal inner product function on the iteration in one of the most widely used channel estimation method, Orthogonal Matching Pursuit (OMP). The study shows that the distance between the selected atoms for each path in OMP can be larger than the sampling interval, which prevents OMP-based methods from achieving better performance. To overcome this drawback, the image deblurring-based channel estimation method, in which the channel estimation problem is analogized to one-dimensional image deblurring, was proposed to improve the large compensation distance of traditional OMP. The advantage of the proposed method was validated by the results of numerical simulation and sea trial data decoding.

Attenuated total reflection Fourier transform infrared (ATR-FTIR) tests were performed on a series of polyurethane prepolymer samples prepared from polymeric methylene diisocyanate (pMDI) and polyether polyol. The absorbance A of the infrared characteristic peak (~ 2 245 cm-1) and the corrected peak area S of isocyanate group (--NCO) were used to linearly fit with the content of--NCO obtained by potentiometric titration, respectively. The results showed that the linear relationship of the latter was better than the former, the correlation coefficients R² were 0.9967 and 0.9856, respectively. According to the working curve between the corrected peak area S and the content of --NCO, the content of --NCO of newly prepared prepolymers were determined. Compared with the potentiometric titration method, the relative error of new working curve was <0.2%, and the relative standard deviation was <0.5%, indicating that the test accuracy is good enough and the method is reliable. As ATR-FTIR is used to determine the --NCO content of polyurethane prepolymer, the sample does not need any pretreatment and volume of samples are tiny. In this way, it does not produce waste liquid and is environmentally friendly. The test results are reliable, and it is convenient for operation and application in industrial production site. [ABSTRACT FROM AUTHOR]

Identification of environmental factors that strongly influence growth indicators (diameter at breast height, tree height and carbon density) for Larix gmelinii forests in the cold-temperate zone on the Greater Khingan Mountains, northeast China will provide an important reference for sustainable management of the forests. In this study, 75 plots were established in L. gmelinii forests during a forest inventory from 2015 to 2022. Sixteen environmental predictors, comprising climatic, edaphic, topographic, and biotic factors, were selected according to their ecological importance for L. gmelinii forests and peer-reviewed literature to determine their influence on the growth of L. gmelinii forests using linear fitting and redundancy analysis. Stocking degree had the strongest significant correlation with carbon density in the tree layer, which increased with increasing stocking degree. Solar radiation had the strongest significant positive correlation with stand average diameter at breast height. The stand average height was most strongly correlated with soil organic carbon content, with which it had a significant positive correlation. Stocking degree, solar radiation and soil organic carbon content were the dominant factors affecting the growth of L. gmelinii forests. Forest management should incorporate improved light and soil conditions and increase the stocking degree to promote growth of L. gmelinii forests. [ABSTRACT FROM AUTHOR]

This paper deals with a recursive filtering problem for a class of discrete time-varying nonlinear networked systems with the encoding-decoding mechanism. The linear fitting method is introduced to handle the nonlinearity. An encoding-decoding mechanism is constructed to describe the data transmission process in wireless communication networks (WCNs). To be specific, the measurement outputs are mapped by a quantizer to unique codewords for transmission in WCNs. Then, the codewords are decoded by the decoder to recover the measurement outputs which are sent to the filter. The processing/encoding delay and network delay have been considered. Firstly, on the premise that the upper bound of the filtering error covariance is minimum, the appropriate filtering gain is calculated. Then, the mean square exponential boundedness of the filtering error is analyzed. Finally, two simulation examples are presented to verify the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Under complex loads, the distributed dislocation technique (DDT) was used to discuss the bifurcating crack problem in a semiinfinite plane, and its correctness was verified. Based on the criterion for the equivalent stress intensity factor, the cause for crack bifurcation was preliminarily explained. The stress intensity factors of bifurcating cracks under different buried depths, loading ratios, bifurcation length ratios, and bifurcation angles were calculated. The multibranch bifurcating crack was also calculated, with the results agreeing well with the finite element method. The results show that, the deeper the buried depth is, the more difficult the bifurcating crack propagation will be. When the burial depth reaches d/a=1.5,the stress intensity factor at the bifurcating crack tip will decrease by about 15%. Moreover, the longer branch will greatly inhibit the extension of the short branch. When the crack length ratio of the 2 branches reaches more than b/c=2,the shielding effect will reach more than 50%; In addition, the bifurcation angles and loading ratios will change the dominant propagation mode of bifurcating cracks. [ABSTRACT FROM AUTHOR]

Starting from a component-level nonlinear model of a turboprop engine, the high-pressure turbine speed and power turbine speed output data at six steady-state operating points are linearized and fitted, and a turboprop engine state variable model is established. Based on these state variable models, the Proportional Integral Derivative (PID) control method, the augmented Linear Quadratic Regulator (LQR) control method and the Linear Quadratic Gaussian/Loop Transfer Recover (LQG/LTR) control method are used to design the controllers respectively, and the relative converted speed of the high-pressure turbine is selected as the scheduling parameter of the Linear Parameter Varying (LPV) model, and the controller is called to control the turboprop engine's non-linear speed. Linear model for large envelope control. Finally, the control effects of the above three control methods are compared and analyzed, and their advantages and disadvantages are compared. The simulation results show that the LPV controller designed based on the LQG/LTR method is more effective than the controllers designed by the other two control methods on the nonlinear turboprop model. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The escalation of anthropogenic heat emissions poses a significant threat to the urban thermal environment as cities continue to develop. However, the impact of urban spatial form on anthropogenic heat flux (AHF) in different urban functional zones (UFZ) has received limited attention. In this study, we employed the energy inventory method and remotely sensed technology to estimate AHF in Beijing's central area and utilized the random forest algorithm for UFZ classification. Subsequently, linear fitting models were developed to analyze the relationship between AHF and urban spatial form indicators across diverse UFZ. The results show that the overall accuracy of the classification was determined to be 87.2%, with a Kappa coefficient of 0.8377, indicating a high level of agreement with the actual situation. The business/commercial zone exhibited the highest average AHF value of 33.13 W m−2 and the maximum AHF value of 338.07 W m−2 among the six land functional zones, indicating that business and commercial areas are the primary sources of anthropogenic heat emissions. The findings reveal substantial variations in the influence of urban spatial form on AHF across different UFZ. Consequently, distinct spatial form control requirements and tailored design strategies are essential for each UFZ. This research highlights the significance of considering urban spatial form in mitigating anthropogenic heat emissions and emphasizes the need for customized planning and renewal approaches in diverse UFZ. [ABSTRACT FROM AUTHOR]

The rapid extraction of farmland boundaries is key to implementing autonomous operation of agricultural machinery. This study addresses the issue of incomplete farmland boundary segmentation in existing methods, proposing a method for obtaining farmland boundaries based on unmanned aerial vehicle (UAV) remote sensing images. Themethod is divided into two steps: boundary image acquisition and boundary line fitting. To acquire the boundary image, an improved semantic segmentation network, AttMobile-DeeplabV3+, is designed. Subsequently, a boundary tracing function is used to track the boundaries of the binary image. Lastly, the least squares method is used to obtain the fitted boundary line. The paper validates the method through experiments on both crop-covered and noncrop- covered farmland. Experimental results show that on crop-covered and non-crop-covered farmland, the network's intersection over union (IoU) is 93.25% and 93.14%, respectively; the pixel accuracy (PA) for crop-covered farmland is 96.62%. The average vertical error and average angular error of the extracted boundary line are 0.039 and 1.473°, respectively. This research provides substantial and accurate data support, offering technical assistance for the positioning and path planning of autonomous agricultural machinery. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

WSN localization occupies an important position in the practical application of WSN. To complete WSN localization efficiently and accurately, the article constructs the objective function based on the target node location constraints and maximum likelihood function. It avoids premature convergence through the PSO algorithm based on chaos search and backward learning. Based on linear fitting, the node-flipping fuzzy detection method is proposed to perform the judgment of node flipping fuzzy phenomenon. And the detection method is combined with the localization algorithm, and the final WSN localization algorithm is obtained after multi-threshold processing. After analysis, it is found that compared with other PSO algorithms, the MTLFPSO algorithm used in the paper has better performance with the highest accuracy of 83.1%. Different threshold values will affect the favorable and error detection rates of different WSNs. For type 1 WSNs, the positive detection rate of the 3-node network is the highest under the same threshold value, followed by the 4-node network; when the threshold value is 7.5 (3 ), the positive detection rate of the 3-node network is 97.8%. Different numbers of anchor nodes and communication radius will have specific effects on the number of definable nodes and relative localization error, in which the lowest relative localization error of the MTLFPSO algorithm is 3.4% under different numbers of anchor nodes; the lowest relative localization error of MTLFPSO algorithm is 2.5% under different communication radius. The article adopts the method to achieve accurate and efficient localization of WSNs.

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Generally, cell guides are installed in the cargo hold of container ships, which improve the loading and unloading efficiency of containers and fix containers when the ship is sailing. However, in actual production, due to the low accuracy of ship loading in sections, and the deviation of welding shrinkage and expansion in relevant sections, errors occur in the loading process of containers, resulting in hidden safety risks or significant economic losses. Given the above situation, it is particularly important to find a high-efficiency cell guide accuracy inspection method for construction monitoring. 3D scanner to obtain three-dimensional data is presented in this paper, based on this paper proposes a new method, this method will be used based on improved instances of 3 d point cloud segmentation model to cell guide the segmentation, and fitting container ship cell guide structure, and then realize the function of container simulation test box, cell guide after the segmentation precision inspection at the same time, for the practicality review, we compared the accuracy data gained from inspection simulation and the measured data. As a result, it was confirmed that both values were within about ±1.5mm. The validity, and reliability of the method are further verified.

Perhaps mentioning the place of Silicon Valley semiconductor companies in business and technology is enough to remind the place of semiconductors in today's world. One of the applications of semiconductors is in manufacturing detection devices. This research aims to investigate the linearity of the response of a PIN photodetector to incident light. For this purpose, we will first simulate a PIN photodetector using COMSOL Multiphysics 6.0 software. Then we expose this photodetector to the light emitted from the scintillator and check the linearity of the response in the range of wavelengths irradiated to it. The research was done on photodetector PINs that are made of two semiconductor materials, GaAs and Si. The temperature and thickness of the intrinsic layer of a photodetector greatly affect its outputs, such as Current Terminal, Quantum Efficiency, and Responsivity. Therefore, the effect of these two parameters on the linearity of the output response of a photodetector has been investigated. To monitor the linearity of the photodetector output in each mode, a Linear Fitting has been applied to the output of the photodetectors using the Origin Pro software, and the linearity of the output data has been controlled from the R-Square and Adjusted R-Square of this fitting. The investigation illustrates that the response of GaAs is more linear than that of Si in similar cases. For example, the GaAs photodetector in the thickness of 8 μm and at the temperature of T = 70 °C has Adjusted R-Square = 0.9972. In contrast, the Si photodetector has Adjusted R-Square = 0.9178 under the same conditions.

The escalation of anthropogenic heat emissions poses a significant threat to the urban thermal environment as cities continue to develop. However, the impact of urban spatial form on anthropogenic heat flux (AHF) in different urban functional zones (UFZ) has received limited attention. In this study, we employed the energy inventory method and remotely sensed technology to estimate AHF in Beijing’s central area and utilized the random forest algorithm for UFZ classification. Subsequently, linear fitting models were developed to analyze the relationship between AHF and urban spatial form indicators across diverse UFZ. The results show that the overall accuracy of the classification was determined to be 87.2%, with a Kappa coefficient of 0.8377, indicating a high level of agreement with the actual situation. The business/commercial zone exhibited the highest average AHF value of 33.13 W m−2 and the maximum AHF value of 338.07 W m−2 among the six land functional zones, indicating that business and commercial areas are the primary sources of anthropogenic heat emissions. The findings reveal substantial variations in the influence of urban spatial form on AHF across different UFZ. Consequently, distinct spatial form control requirements and tailored design strategies are essential for each UFZ. This research highlights the significance of considering urban spatial form in mitigating anthropogenic heat emissions and emphasizes the need for customized planning and renewal approaches in diverse UFZ.

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Featured Application: Space object detection. The limited resource of Geostationary Earth Orbit (GEO) is precious and most telecommunication, weather and navigational satellites are placed in this orbit. In order to guarantee the safety and health of active satellites, advanced surveillance and warning of unknown space targets such as space debris are crucial. However, space object detection still remains a very challenging problem because of the weak target characteristics and complex star background. To solve this problem, we conduct a deep-learning-based framework called PP-YOLOv2 for single-frame object detection and design a post-processing algorithm named CFS for further candidate filtration and supplement. First, we transform the label information and generate the according bounding boxes to train the PP-YOLOv2 detector to extract candidate coordinates for each frame. Then, the CFS technique is designed as an effective post-processing procedure to obtain the eventual prediction results. Experiments were conducted over a dataset from the Kelvins SpotGEO challenge, which demonstrate the effectiveness and the comparable detection performance of our proposed pipeline. Finally, the deployment results on NVIDIA Jetson Nano show that the proposed method has a competitive application prospect for a space target monitoring system. [ABSTRACT FROM AUTHOR]

Spectral photon-counting computed tomography (sCT) appears as a promising imaging technique for clinical applications thanks to its ability to offer low dose and possibility of quantitatively analyzing the composition of materials in a pixel. However, due to the dispatching of photons into different energy bins, the quality of sCT image at each energy bin is considerably degraded. We propose a reconstruction method for sCT images by combining multi-energy information. The method is based on clustering pixels containing similar material compositions, performing linear fitting within each class for all the energy images two-by-two, projecting the pixel values of the images at other energy bins to the pixel of the image at the current energy bin, and combining the original pixel value and projected pixel values. The results on both simulation and real data demonstrated the effectiveness of the proposed method, in terms of both image reconstruction quality and material decomposition accuracy.

In order to solve the problem of inaccurate fault location in the transmission network under some abnormal conditions, such as traveling wave location device faults, startup failure and time recording error, a novel traveling wave fault location method based on directed tree model and linear fitting is proposed. A directed tree model of the fault traveling wave transmission along the shortest path is established based on graph theory analysis of traveling wave transmission network. Two straight lines are fitted on the coordinate plane where the accurate fault location is obtained direct by coordinate information of the intersection of these two fitted straight lines (FSLs), according to the transmission characteristics of the fault traveling wave in the directed tree model. The wave velocity is used as the slope of the fitted straight line, and the influence of its uncertainty on the fault location is eliminated. The time record error points of the location device are automatically eliminated in the linear fitting. PSCAD simulation results prove that fault information of the entire transmission network is comprehensively utilized by the proposed method and the ring network is automatically unlooped. The reliability and accuracy of fault location are remarkably improved, particularly for the fault scenarios with recorded information abnormity.

The attrition behavior of CaO-based adsorbent particles was systematically studied in a laboratory-scale fluidized device. Five operational and design parameters were investigated in terms of attrition. Fine powder production, attrition rate and particle size statistics were experimentally analyzed to explore the attrition characteristics of the particles. The results revealed that longer time aggravated the breakage, and larger particles possessed the better attrition resistance. Higher gas velocity promoted the attrition rate. Larger orifice number and orifice diameter reduced the degree of attrition. Linear fitting was used to analyze the relation between the mass of fine powder and other parameters. A mathematical model- R = 0.67 × 10 9 ⋅ D − 0.848 ⋅ U 3.136 ⋅ n or − 0.950 ⋅ d or − 1.196 was established on the basis of experimental results to combine the effects of the various parameters. The model could be used to describe, simulate and predict the fluidized attrition phenomenon of particles. [Display omitted] • Different operational and design parameters were studied in a fluidized system in terms of attrition. • Influences of attrition of bed particles on the attrition rate and particle size distribution were explored. • The relationship between the mass of fine powder and other parameters was analyzed by linear fitting. • A mathematical model was developed to describe and predict the fluidized attrition phenomenon of particles. [ABSTRACT FROM AUTHOR]

Friction stir processing has gained remarkable success in producing ultrafine-grained structures and surface composites. In this context, the primary objective is to establish a linear relationship between local strength (i.e. hardness) and bulk mechanical strength (i.e. tensile strength) of friction stir processed aluminum alloys using experimental investigations on selected alloy system together with data reported in literature sources. Initially, authors generated a linear relation between hardness and strength of friction stir processed aluminum alloys under different cooling conditions. After friction stir processing, recrystallized fine grains were formed and better refinement was achieved in cooling-assisted friction stir processing. Irrespective of grain refinement, the strength and hardness of friction stir processed samples were found to be lower compared to the base metal due to the precipitation phenomenon during friction stir processing. At the same time, hardness and strength improved in cooling-assisted friction stir processing compared to natural-cooled friction stir processing due to better grain refinement going by the parameters of Hall–Petch equation. For friction stir processed samples, relevant constants were found using Hall–Petch equation. The experimental values of hardness and strength were well fitted with the formulated equations due to the formation of a homogeneous fine-grained structure. Also, two novel linear relations were successfully established between hardness and strength with proportionality constants of 1.9 and 2.7, respectively. On the other hand, it was also concluded that it is not possible to establish a linear relation between hardness and strength of surface composites due to structural inhomogeneity and agglomeration of reinforcement particles. [ABSTRACT FROM AUTHOR]

Conventional orthogonal matching pursuit (OMP) based channel estimation adopts discretized grids to represent path delays, which leads to energy leakage of off-grid paths. From the perspective of linear fitting, utilizing multiple atoms with fractional delays and shortening the distance between these atoms in the off-grid path reconstruction can reduce the energy leakage. To this end, an improved OMP channel estimation scheme is proposed in this letter for higher estimation accuracy. The proposed scheme utilizes trigonometric function based interpolation twice to estimate the delays of two atoms, which are adopted to reconstruct an off-grid path. Furthermore, a two-step search strategy is introduced to keep low computational complexity. The advantage of the proposed scheme is validated in simulations. [ABSTRACT FROM AUTHOR]

It’s a key issue in the research of polarized light navigation to obtain the solar position information efficiently and accurately by using the polarized skylight pattern. But existing calculation methods for solving solar position use time-consuming data-processing algorithms that solve nonlinear equations. In this paper, we propose a linear data-processing method to calculate solar position by utilizing the $\infty $ characteristic model of the polarized skylight pattern. The linear analytic model of the solar azimuth angle and zenith angle are established respectively by polar coordinate transformation of the $\infty $ characteristic model of polarized skylight pattern, which transforms the solution of solar position into the slope solution of the linear equations. The measured experiments under clear, cloudy and partial occlusion conditions verify the effectiveness and better robustness of our linear algorithm, which can provide a more simple and efficient method to achieve the solar position. [ABSTRACT FROM AUTHOR]

Eddy current displacement sensor (ECDS) is a non-contact sensing device. This paper proposes an ECDS by using the colpitts circuit with the characteristics of longer measurement range and better linearity. The parameter R p is separated from an improved colpitts circuit. By measuring R p and optimizing probe sensitivity, the measurement range of the sensor is increased, which extends to 56% of probe diameter, the maximum measurement distance reaches 72% of probe diameter. A linear-fitting method based on MCU is proposed, which improves the linearity, consistency, and response speed of the sensor. The principle and design are explained in detail, and verified through field circuit coupling simulation. Finally, the ECDS is tested by using a precision electronically controlled displacement platform, the experiment results show that the sensor performance has a high consistency, and linearity can be reduced to within ± 0.4%, sensitivity is 0.28 V/mm, resolution is 6 µm. The ECDS is identified to be practical, the method proposed in this article effectively improves the measurement range and linearity, therefore, the ECDS is widely used in displacement measurement, which need long distance, high precision and fast response. [Display omitted] • By optimizing probe sensitivity, the measurement range of the sensor is increased. • The design is verified by using a field circuit coupling simulation method. • A linear-fitting method improves the linearity, consistency and response time. • Measurement range reach 56% of probe diameter, linearity is within ± 0.40%. [ABSTRACT FROM AUTHOR]

The influence of the thickness variation of the cell wall on the active heat dissipation of the cellular sandwich was studied by deducing the thermal performance index of the cellular sandwich with variable thickness. The relationship between the relative density and the thermal performance index of the cellular sandwich with different cell structures was analyzed. Then, the maximum thermal performance index and the optimum relative density of the cellular sandwich with different cell structures were obtained. The relationship between the maximum thermal performance index and the optimal relative density and the variable thickness parameter was given by using linear fitting. The influence of the thickness of cell wall thickness on the optimal relative density and maximum thermal performance index of different cell structures was analyzed. It was concluded that the change in cell wall thickness has the slight effect on the hexagon, and the effect on the triangle and square is big.

Research on IoT that merely aims at connecting and communicating is about to past. Thereafter, general objects should have the capability to learn, think, and understand both physical and social areas by themselves. Cognitive Internet of Things (CIoT) attempts to empower the current IoT with a “brain” for high-level intelligence, requiring networks to have the ability to bridge the physical and social worlds. This attempt means matching equipment and resources with people and their behavior. Therefore, accurate location information is crucial for equipment connecting to CIoT. This endeavor sets a higher requirement for the localization technology of wireless sensor networks in terms of accuracy, energy, and efficiency compared with that in the past. In this paper, we propose an efficient and accurate mobile anchor node assisted localization algorithm for WSNs based on diameter-varying spiral line (LDVSL), which broadcasts coordinates of the anchor node to assist localizing unknown sensor nodes. The proposed algorithm has two main innovations. First, we obtain the mobile anchor node position through a time and angle mechanism instead of GPS, given the unique characteristics of the diameter-varying spiral line. Second, the linear fitting method is adapted to select the key virtual node, which has the real maximum received signal strength indicator. Simulations indicate that the proposed LDVSL algorithm outperforms other similar algorithms in terms of average localization error and positionable node ratio. The simulations also show that the LDVSL is not affected by obstacles seriously and has good robustness. The LDVSL has a wide prospect of application in CIoT.

The methane bubble plume attracts interest because it offers direct evidence of seafloor gas leakage and plays an indirect role in the exploration and identification of natural gas hydrate. In this study, based on established plume models and their migration sections, three amplitude-class attributes were extracted from three formations for the migration sections of five plumes, and the correlation between the gas content and seismic attribute was obtained. As the gas content increases, the amplitude attribute correspondingly increases, and the linear correlation is relatively good. Moreover, correlation coefficients between gas content and amplitude attributes are close to 1.0. By using linear fitting, the relation model between the gas content of the plume and the seismic attribute was obtained. The relation model was subsequently used to invert the gas content from a real data-bearing plume. Comparison of the gas content section of the plume with the attribute section and real seismic section reveals common distribution characteristics, namely, the color of the section in the lower right corner is dark. If the amplitude value is large in the seismic section of the real plume, the amplitude attribute value is also large in the corresponding attribute section, and the inverted value of the gas content is also large (because gas content and amplitude are linearly correlated), which indicates that the plume bubbles of the section in the lower right corner is intensively distributed. Finally, the obtained gas content section of the plume can reflect the distribution of the plume bubble content more simply and intuitively, from which the distribution law of seafloor bubbles can be deduced, and this lays a foundation for the further estimation of the gas content of the plume and hydrate reserves. [ABSTRACT FROM AUTHOR]

Investigating the effect of common allergens on allergic disease is very important for human health. In this paper, we firstly propose the models for predicting the relationship between 39 common allergens and total IgE level. The total IgE level is utilized to evaluate the order of severity for allergic disease. In particular, we employ the linear fitting method and neural network based method to obtain the models with high prediction accuracy. The feasibility of the proposed models can be confirmed by testing two other independent data sets from hospital diagnosis record. Additionally, we obtain some useful medical conclusions.

The limited resource of Geostationary Earth Orbit (GEO) is precious and most telecommunication, weather and navigational satellites are placed in this orbit. In order to guarantee the safety and health of active satellites, advanced surveillance and warning of unknown space targets such as space debris are crucial. However, space object detection still remains a very challenging problem because of the weak target characteristics and complex star background. To solve this problem, we conduct a deep-learning-based framework called PP-YOLOv2 for single-frame object detection and design a post-processing algorithm named CFS for further candidate filtration and supplement. First, we transform the label information and generate the according bounding boxes to train the PP-YOLOv2 detector to extract candidate coordinates for each frame. Then, the CFS technique is designed as an effective post-processing procedure to obtain the eventual prediction results. Experiments were conducted over a dataset from the Kelvins SpotGEO challenge, which demonstrate the effectiveness and the comparable detection performance of our proposed pipeline. Finally, the deployment results on NVIDIA Jetson Nano show that the proposed method has a competitive application prospect for a space target monitoring system.

Heat conductivity and multiple correlation coefficients of various drill holes under high and low-power levels were acquired through the field heat response test, so as to capture heat exchanging performances of the ground heat pump system. Moreover, by analyzing the changing characteristics of heat conductivity with IGSHPA linear heat source model, significant deviations were found between test results of heat conductivity when the high and low-power tests are conducted at short intervals, which was resulted from the influence of the residual temperature field of the first test on the second test, that is, the temperature is not returned to the initial temperature yet. Deviation caused by short test intervals between high and low-power test results can be eliminated by the line-source superposition method. In addition, by introducing the time function, the exact value of heat conductivity obtained by the second test can be solved with the utilization of linear relationship between the time function and the average temperature of the fluid. The dependence of fitting the linear heat source was verified. By calculating the linear regression of important parameters in the linear heat source superposition method, the linear fitting upon processing is characterized by good degree of fitting, small temperature deviation, and significant linear correlation. The linear heat source superposition method was proven to be reliable and accurate. Also, the analysis result shows that there is no need to process data using the linear heat source superposition method when two tests are conducted at long intervals. [ABSTRACT FROM AUTHOR]

A novel differential method based on linear fitting is proposed to improve the accuracy of the pulse-ranging system. In this method, the Peak Points (PPs) of the traditional echo signal transformed into the Positive-Going Zero-Crossing Points (PGZCPs) of the differential echo signal. Then, we obtained the true zero-crossing point by the linear fitting of points near PGZCPs. We compared the differential method based on linear fitting (DMLF) and peak method. The Root Mean Square Error (RMSE) found with our method (0.1661 ns) is nearly a 50% reduction compared to that of the peak method (0.3318 ns), and a large number of experiments have demonstrated that the Relative Error (RE) of our proposed method is less than 30 ppm. [ABSTRACT FROM AUTHOR]

Clustering by fast search and finding of density peaks algorithm (DPC) is a recently developed method and can obtain promising results. However, DPC needs users to determine the number of clusters in advance, thus the clustering results are unstable and deeply influenced by the number of clusters. To address this issue, we proposed a novel algorithm, namely LDPC (Linear fitting Density Peaks Clustering algorithm). LDPC uses a novel linear fitting method to choose cluster centres automatically. In the experiments, we use public datasets to access the effectiveness of LDPC. Especially, we applied LDPC to image segmentation tasks. The experimental results show that LDPC can obtain competitive results compared with other clustering algorithms.

According to the requirement of low-concentration dust emission in China, this paper designed a low-cost and high-precision dust detection system based on Mie scattering. Through theoretical analysis, the relationship between the intensity of scattered light and the concentration of soot is obtained. The laser emitting unit, signal receiving unit and STM32 data processing unit are designed. The driving principle of laser modulation and the principle of selective signal amplification of weak signal are analyzed. The host computer program is written with LabVIEW software, and the test data are displayed on the front panel of the host computer. The experimental results show that this system has high sensitivity, fast response, good repeatability, and can be measured online for a long time, which means this system has good practicability.

Background: Glucose is an important material in human metabolism. The establishment of glucose reference measurement procedures and to study the uncertainties of measurement is of great significance. Linear fitting and dilution of reference material were used in the measurement of glucose concentration and they are common operations in daily work. Investigation of the measurement uncertainty of these operations will be of important significance to clinical laboratory medicine. However, in the field of laboratory medicine, related research was rarely reported. Methods: The spectrometric quantification of glucose is an application of the enzymatic reference method with hexokinase. The sources of uncertainty in the measurement process were analyzed. The measurement uncertainties in the study were evaluated according to GUF method and the method introduced by Quantifying Uncertainty in Analytical Measurement (QUAM) was also applied in the evaluation of the measurement of linear fitting. Results: The standard curve was built successfully according to the measurement procedure recommended by the CDC and the linear equation was y = 0.000807x + 0.001213 (R² = 0.999179). The measurement uncertainty of glucose in the sample was 0.450,408 mmol/L. Conclusions: The method for the determination of serum glucose concentration by hexokinase in our laboratory has been successfully established. The measurement uncertainty was consistent with the GUF method and the method introduced by Quantifying Uncertainty in Analytical Measurement (QUAM) in the process of linear fitting when the glucose concentration was measured by the reference method (hexokinase method). [ABSTRACT FROM AUTHOR]

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The total biomass of a stand is an indicator of stand productivity and is closely related to the density of plants. According to the self-thinning law, mean individual biomass follows a negative power law with plant density. If the variance of individual biomass is constant, we can expect increased stand productivity with increasing plant density. However, Taylor's power law (TPL) that relates the variance and the mean of many biological measures (e.g. bilateral areal differences of a leaf, plant biomass at different times, developmental rates at different temperatures, population densities on different spatial or temporal scales), affects the estimate of stand productivity when it is defined as the total biomass of large plants in a stand. Because the variance of individual biomass decreases faster than mean individual biomass, differences in individual biomass decline with increasing density, leading to more homogeneous timbers of greater economic value. We tested whether TPL in plant biomass holds for different species and whether the variance of individual biomass changes faster than the mean with increasing stand density. The height, ground diameter and fresh weight of 50 bamboo species were measured in 50 stands ranging from 1 m by 1 m to 30 m by 30 m to ensure more than 150 bamboos in every stand. We separately examined TPL in height, ground diameter, and weight, and found that TPL holds for all three biological measures, with the relationship strongest for weight. Using analysis of covariance to compare the regression slopes of logarithmic mean and variance against the logarithm of density, we found that the variance in individual biomass declined faster than the mean with increasing density. This suggests that dense planting reduced mean individual biomass but homogenized individual biomass. Thus, there exists a trade-off between effective stand productivity and stand density for optimal forest management. Sparse planting leads to large variation in individual biomass, whereas dense planting reduces mean individual biomass. Consequently, stand density for a plantation should be set based on this trade-off with reference to market demands. [ABSTRACT FROM AUTHOR]

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With the explosive growth of micro-learning resources, a large number of unprocessed fragmented text resources bring great inconvenience to learners. In order to help learners to find suitable contents from fragmented resources for personalized learning, it is necessary to cluster micro-learning resources in the form of text. Therefore, this paper attempts to apply an improved density peak algorithm to micro-learning unit text clustering. Aiming at the problems of high dimensional sparse vector space, insufficient global consistency, cutoff distance sensitivity, and supervised selection of density peak centers when the density peak algorithm perform clustering in its field, this paper proposes two ap-proaches based on Latent Semantic Analysis (LSA) model. Firstly, a new definition of local density is proposed according to clustering requirements, density sensitive distance is used as the clustering criteria, and the global consistency problem of clustering is solved by solving the problem of cutoff distance sensitivity. Secondly, outliers are found by linear fitting to automatically find the density peak centers in order to realize unsupervised selection problem of peak centers. Experimental results on real data sets of micro-learning units show that the proposal is more suitable for text clustering of micro-learning units than the original algorithm and other classical clustering algorithms. [ABSTRACT FROM AUTHOR]

A passive homodyne phase demodulation technique based on a linear-fitting trigonometric-identity-transformation differential cross-multiplication (LF-TIT-DCM) algorithm is proposed. This technique relies on two interferometric signals whose interferometric phase difference is odd times of π. It is able to demodulate phase signals with a large dynamic range and wide frequency band. An anti-phase dual wavelength demodulation system is built to prove the LF-TIT-DCM algorithm. Comparing the traditional quadrature dual wavelength demodulation system with an ellipse fitting DCM (EF-DCM) algorithm, the phase difference of two interferometric signals of the anti-phase dual wavelength demodulation system is set to be π instead of π/2. This technique overcomes the drawback of EF-DCM—that it is not able to demodulate small signals since the ellipse degenerates into a straight line and the ellipse fitting algorithm is invalidated. Experimental results show that the dynamic range of the proposed anti-phase dual wavelength demodulation system is much larger than that of the traditional quadrature dual wavelength demodulation system. Moreover, the proposed anti-phase dual wavelength demodulation system is hardly influenced by optical power, and the laser wavelength should be strictly limited to lower the reference error.