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This letter presents an algorithm for canceling crosstalk in multiconductor transmission lines (MTL). At present, to reduce the crosstalk, multiconductor systems usually use differential mode transport, in which the number of transmitted signals is half the number of conductors. A method is proposed to cancel crosstalk in MTL, through the singular value decomposition (SVD) method in matrix theory, in which the transmission line matrix is converted into an identity matrix. That is, the off-diagonal elements in the transmission matrix are zero, which corresponds to crosstalk cancellation. In this letter, this method is applied to the previous literature models to verify its effectiveness firstly. Then, the method is applied to a triple-twisted strand. In the strand, different rotation degrees correspond to different per unit length (p.u.l) parameter matrix. A set of parameters are extracted, the rest of are predicted by the beetle antennae search-back propagation neural network (BAS-BPNN) proposed in a previous work. The simulation results show that the near and far end crosstalk can be canceled effectively.

Based on the theory of multi-conductor transmission lines (MTL), this paper proposes a new method for predicting and suppressing crosstalk of twisted-wire pair (TWP). The per unit length (p.u.l) RLCG parameters change caused by the inconsistent cross-sectional shape of TWP, changes in parameters make it difficult to solve the telegraph equation. In this paper, the method of transmission lines cascade is used. TWP is divided into several segments, and p.u.l parameters of each segment are predicted. Compared with before method, we propose a higher precision algorithm—beetle swarm optimization (BSO) to optimize the weights of back-propagation (BP) neural network, which predict p.u.l parameters at each segment. On this basis, it is divided into two steps: 1) Use MTL frequency domain method combined with lines’ terminal conditions to solve crosstalk and compare with CST simulation results; 2) Use the singular value decomposition (SVD) method to add matrix modules at both ends of lines for suppressing crosstalk. The results show that proposed method in this paper is consistent with the simulation, and the accuracy is higher than before

At high altitudes, the corona discharge of alternating current transmission lines is more severe, and the induced radio interference (RI) level is higher. Foul weather, especially rain, can aggravate RI performance. In this article, to investigate the influence of rain intensity on RI level at high altitudes, an ultra-high-voltage (UHV) corona cage was employed to perform RI measurements for four bundled conductors (4 × LGJ 630, 6 × LGJ 500, 8 × LGJ 500 and 8 × LGJ 630) by using an artificial rain system at an altitude of 2261 m. The RI levels of the four conductors were obtained under fair weather and under 1.5, 2, 6, 12, and 18 mm/h of rainfall. Then, the RI performances of a 1000 kV UHV single circuit lines and a 1000 kV double circuit line on the same tower were calculated using the excitation function approach. Finally, the difference between predicted RI values at high altitude and long-term measurements for operational power lines at low altitude were discussed.

This paper presents an algorithm for predicting crosstalk in multiconductor transmission lines (MTL). Currently, crosstalk has an increasing impact on signal integrity. In the twisted pair cable (T...

This paper proposes a novel crosstalk prediction method between the triple-twisted strand (uniform and non-uniform) and the signal wire, that is, using back-propagation neural network optimized by the beetle antennae search algorithm based on chaotic disturbance mechanism (CDBAS-BPNN) to extract the per unit length (p.u.l) parameter matrix, and combined with the chain parameter method to obtain crosstalk. Firstly, the geometric model and cross-sectional model between the uniform triple-twisted strand and the signal wire are established, and the corresponding model between the non-uniform triple-twisted strand and the signal wire is obtained by the Monte Carlo (MC) method. Then, the beetle antennae search algorithm based on chaotic disturbance mechanism (CDBAS) and backpropagation neural network (BPNN) are combined to construct a new extraction network of the p.u.l parameter matrix, and the chain parameter method is combined to predict crosstalk. Finally, in the verification and analysis part of the numerical experiments, comparing the crosstalk results of CDBAS-BPNN, BAS-BPNN and Transmission Line Matrix (TLM) algorithms, it is verified that the proposed method has better accuracy for the prediction of the model.

Power electronic devices and electrical equipment produce a large quantity of radiated electromagnetic interference (EMI) in the working process. Electromagnetic field analysis method of the near-field and far-field of the antenna can be employed to separate the radiated interference noises. However, the method has low separation accuracy and requires a lot of time. A novel method based on joint approximate diagonalization algorithm (JADA) to separate the radiated EMI noise is proposed in this paper. Compared with the traditional independent component algorithm method, the accuracy is improved by 14% and the efficiency is increased by 30%. The common-differential mode mixed noise source is taken as the experimental object to demonstrate the effectiveness and simplicity of the proposed method.

In this paper, a new algorithm for predicting per unit length (p.u.l) parasitic parameters of transmission line is proposed. In the twisted-wire pair (TWP), different rotation degrees correspond to different parasitic parameters, which brings difficulties to the solution of telegraph equation. At present, the mainstream method is to divide TWP and use the cascade theory to solve each segment as a parallel transmission line. Therefore, we propose to use the beetle swarm optimization (BSO) algorithm to optimize the weights of the back propagation neural network, use a certain sample to train the network. This algorithm is used to predict the p.u.l parameters of uniform and non-uniform TWP, and the finite-difference time-domain (FDTD) method is used to solve telegraph equation. Among them, the crosstalk value of the uniform TWP is compared with the simulation value in the CST to verify the effectiveness of the proposed algorithm; the non-uniform TWP performs 500 random generation calculations to give the maximum envelope value of the crosstalk.

Based on the characteristic parameters of a noise discrimination network (NDN), the Mardiguian network is used as an example to investigate the influence of stray capacitance on the performance of the NDN. The obtained results show that stray capacitance has a significant effect on the performance of the NDN. Considering the influence of stray capacitance, this paper proposes a network optimization method based on the Mardiguian network. The optimization method is superior to the Mardiguian network in performance, and it improves the separation accuracy of differential mode noise.

The biological effects of extremely low-frequency electromagnetic fields (ELF-EMF) exposure are not fully clarified. We conducted this investigation to explore the effects of ELF-EMF on hematologic and biochemical indexes in adult rats. Thirty adult male Sprague-Dawley rats were exposed to ELF-EMF at 1 mT for 24 weeks, while another 30 SD rats were sham exposed. During the exposure, peripheral blood was collected every 4 weeks to analyze the hematologic parameters and biochemical indexes. The morphology of liver and kidney was detected by hematoxylin-eosin staining at the end of the experiment. Exposed to ELF-EMF at 1 mT did not exert any statistic difference on hematologic parameters including total white blood cell count, neutrophil ratio, lymphocyte ratio, red blood cells, hemoglobin concentration and platelets count, compared to the control group. Similarly, biochemical indexes, such as glucose, lipid profile, liver function and renal function, were not affected by ELF-EMF exposure. In addition, no morphological change was observed in the liver and kidney from the exposure group. The exposure to ELF-EMF at the intensity of 1 mT for 24 weeks did not affect hematologic and biochemical indexes in adult rats.

According to the electromagnetic compatibility standard of the existing online monitoring equipment, the interference mechanism of the base station antenna to the online monitoring equipment is analyzed. It is recommended to use the radio frequency radiation immunity of 10V / m as the anti-interference design limit. Combined with the antenna principle, the mathematical characterization formula of the base station antenna field source is deduced, so that a mathematical model for solving the scattering field of the electric large-size metal scatterer at any point in space under the multi-base station antenna radiation is proposed. Taking the Shandong shared iron tower as an example, the electric field strength change rule of the online monitoring equipment under the three working conditions of the tower head type, antenna power and antenna inclination is analyzed. Based on this, it is recommended to The protective spacing is set at 4 meters.

The shared tower integrates power and communication equipment, and its new base station antenna makes the passive interference mechanism and level of transmission line to the radio station adjacent to the line change. Therefore, the passive interference mechanism of the shared tower to the station is analyzed. Compared with the traditional transmission line, the shared tower is the combination of the scatterers with discontinuous electricity, and the second-order coupling scattering will occur among the scatterers. The compound scattering field model of the shared tower under the coupling effect is established, and the scattering field under the coupling background is solved by using the equivalent principle and reciprocity theorem, so as to realize the solution of passive interference level. Taking the tower type, incident angle and antenna power of the shared tower as variables, the passive interference levels of stations with different frequencies under three factors are solved respectively, and the change rule of passive interference of the shared tower is obtained. It is suggested that the shared tower should take some passive interference protection measures for the stations adjacent to the base station antenna frequency.

Power-frequency electromagnetic fields (PF-EMFs) at 50 Hz are potential health risk factors. This study aimed to explore the effects of long-term exposure to 50-Hz PF-EMFs on general physiological conditions in Sprague-Dawley (SD) rats. During a 24-week exposure period, the body mass and water and food intake of the animals were recorded regularly. The hematologic parameters were detected every 12 weeks, and blood chemistry analyses were performed every 4 weeks. After sacrifice, morphology was identified by hematoxylin-eosin, Masson, and immunohistochemical staining. Fibrosis-related gene expression and oxidative stress status were also detected. Compared with the control group, exposure to 30, 100, or 500 μT PF-EMF did not exert any effect on body mass, food intake, or water intake. Similarly, no significant differences were found in hematologic parameters or blood chemistry analyses among these groups. Furthermore, morphological assays showed that exposure to PF-EMFs had no influence on the structure of the liver or kidney. Finally, fibrosis-related gene expression and oxidative stress status were unaltered by PF-EMF exposure. The present study indicates that 24 weeks of exposure to PF-EMFs at intensities of 30, 100, or 500 μT might not affect hemograms, blood chemistry, fibrosis, or oxidative stress in the liver or kidney in SD rats. © 2020 Bioelectromagnetics Society.

In the present study, the effects of power-frequency magnetic fields (PF-MF) on fertility and development were investigated in rats and mice. Adult Sprague-Dawley rats and C57BL/6J mice were divided into four groups: a sham exposure group and 30-µT, 100-µT and 500-µT PF-MF exposure groups. The rats were exposed for 24 weeks, and the exposure time for mice ranged from 18 d to 12 weeks, dependent on the different investigated end points. The rats and mice were exposed for 20 h/d. Plasma hormone levels in rats and mice were analyzed. Furthermore, pregnancy rates and implanted embryos were recorded in pregnant mice. Finally, the neonatal growth of mice was evaluated. The results showed that none of the three intensities affected the body weight and paired ovary weight in female rats. Meanwhile, none of the three intensities affected the body weight, weights of paired testes, weights of paired epididymis and sperm count in male rats. Similarly, no significant differences were found in plasma sex hormone levels between the different PF-MF exposure groups and the sham exposure group. In addition, the pregnancy rates and implanted embryos were not significantly different between the four groups. Moreover, PF-MF exposures had no effects on either the number of fetuses in pregnant mice or the growth and development of neonatal mice.

How to determine the effects of electromagnetic phenomena in the environment on human health is one of the main concerns of scholars. The biological effects of electromagnetic fields are related to the characteristics of electromagnetic fields and the electromagnetic properties of biological tissues. The main purposes of this paper are as follows: on the one hand, to explore the statistical laws of animal behavior of Sprague Dawley (SD) rats in magnetic field exposure devices, and strive to pass them. Statistical data confirm the consistency of animal behavior in SD rats with and without magnetic field exposure. On the other hand, the rationality of the current mainstream magnetic field limit is demonstrated from the side. Based on the self-developed magnetic field exposure device, the animal behavior of SD rats was studied by open-field experiment, elevated cross maze experiment and water maze experiment. The control group (0 μT exposure) and exposure group (30μT exposure, 100μT exposure,500 μ T exposure) in the very low frequency electromagnetic field exposure device were analyzed by SPSS statistical analysis software. While ensuring the integrity of the experimental steps, the statistical rules of animal behavior of SD rats under magnetic field exposure of 30μT, 100μT and 500μT were consistent with those at 0μT. The results showed that 30μT, 100μT and 500μT magnetic field exposure did not affect rats. In order to produce the conclusion of direct interference and direct influence, the rationality of the current mainstream magnetic field limit is proved.

Wind turbine blade is the most vulnerable part of wind turbine to lightning damage. Its lightning resistance directly determines the lightning protection technology of wind turbine. Therefore, it is extremely important to study the wind turbine blades’ electromagnetic environment and lightning strike characteristics under lightning guidance. Based on the analysis of the traditional rules algorithm, the influence factors of the lightning strike characteristics of wind turbines are obtained. It is clear that the procedure method calculates the number of lightning strikes without considering the lightning current amplitude, the highest point of the wind turbine and the unidentified up and down lightning strikes. Based on this, the existing lightning leader development model is introduced to reveal the charge distribution of the downlink lightning leader channel with different lightning currents. Then, based on the simulated charge method and the quasi-static method, the algorithm for solving the spatial electric field distribution of the wind turbine blade under the lightning leader development model is proposed. Finally, the electromagnetic field distribution characteristics at different heights under blade rotation conditions are obtained. The calculation results of Jinfeng 77/1500 wind turbine show that the surface electric field distribution characteristics of the blades are improved significantly after the installation of the lightning receptors. It is also recommended that the best installation position of the lightning receptor be 1m from the tip of the wind turbine blade.

According to GB 6364-2013 "Aeronautical Radio Navigation Station Electromagnetic Environment Requirements", China lacks the design and construction basis for the protection spacing of shared iron towers. To this end, starting from the interference protection rate of the aeronautical radio navigation station, by establishing a mathematical solution model for the protection distance between the shared tower and the aeronautical radionavigation station, the installation method of the shared tower, the type of the tower and the base number of the tower under a certain line length are carried out. The analysis and the law of the interference protection rate under the influence of these three variables are changed with the distance between the two systems. The results show that the main factors affecting the aeronautical radio range finder station are the installation mode of the shared tower and the number of towers under a certain line length. According to the research results, it is reasonable to set the protection distance between the shared tower and the aeronautical radio navigation station to be within the range of 500m~700m.

With the overall development of the construction of the shared tower, the electromagnetic interference of the communication base station to the surrounding on-line monitoring equipment has become increasingly prominent, but at present there is no standard and construction basis for the protection distance at home and abroad. In this paper, PO-MoM hybrid algorithm is used to calculate the electromagnetic environment of on-line monitoring equipment on shared tower, and the influence of communication antenna on the electromagnetic environment of on-line monitoring equipment on shared tower is obtained. Through the analysis and calculation of tower type, antenna power and different erection modes of antenna, the influence rules of three factors on radiation immunity of on-line monitoring equipment are solved. According to the research results, it is suggested that the protection distance between the communication base station and the on-line monitoring equipment should be set to 15-27m. The results provide a theoretical basis for the further study of the optimal layout of communication antennas on the shared tower and the design of electromagnetic safety engineering of the shared tower, and have certain practical value.

The effects of high voltage electromagnetic fields (EMF) on populations of aphpids, leaf miners and snails associated with rapeseed under subtropical conditions were studied. A field study was conducted during the spring season of 2015, at Wuhan, China (30.59°N, 114.30°E; 23.3 m asl). Plots with four different emission rates (0 kV, 5.2 kV, 26 kV and 39 kV) were established, each containing an EMF emission device located 2.6 m above the soil, Lipaphis erysimi aphid and Liriomyza brassicae leaf miner population densities were recorded at 10 d intervals throughout the cropping season. Aphids, leaf miners and snails infested all plots, but significantly higher population densities of all pests were observed in control plots. The plots with the highest emission rate (39 kV) had lower population densities of pests throughout the entire experiment. High voltage EMF may have the ability to suppress pests of rapeseed. However, much remains to be learned about the suitability and reliability of EMF for in...

The complete fluidic sprinkler (CFS) has the advantages of a simple structure and the ability to work well at a lower nozzle pressures. CFS is a gas–liquid fluidic sprinkler, whose driving moment is achieved by a flow reaction as a result its droplet characteristics differ from those of conventional sprinklers. To study the droplet characteristics of the CFS, droplet diameter and velocity were measured using a Thies Clima laser precipitation monitor (TCLPM). Statistical analysis was conducted on the droplet size distribution using a volume-weighted method and droplet velocity was analysed using a number-weighted method. The results showed that volume mean droplet diameter and volume medium diameter increased with the distance from the nozzle and decreased with the nozzle size. The frequency of droplets with a diameter

Although numerous studies have reported the influence of extremely low frequency magnetic field (ELF-MF) exposure on human health, its effects on cognitive deficits in Alzheimer's disease (AD) have remained under debate. Moreover, the influence of ELF-MF on hyperphosphorylated tau, which is one of the most common pathological hallmarks of AD, has not been reported to date. Therefore, transgenic mice (3xTg) were used in the present study. 3xTg mice, which express an APP/PS1 mutation combined with a tau (P301L) mutation and that develop cognitive deficits at 6 months of age, were subjected to ELF-MF (50Hz, 500μT) exposure or sham exposure daily for 3 months. We discovered that ELF-MF exposure ameliorated cognitive deficits and increased synaptic proteins in 3xTg mice. The protective effects of ELF-MF exposure may have also been caused by the inhibition of apoptosis and/or decreased oxidative stress levels that were observed in the hippocampus tissues of treated mice. Furthermore, tau hyperphosphorylation was decreased in vivo because of ELF-MF exposure, and this decrease was induced by the inhibition of GSK3β and CDK5 activities and activation of PP2Ac. We are the first to report that exposure to ELF-MF can attenuate tau phosphorylation. These findings suggest that ELF-MF exposure could act as a valid therapeutic strategy for ameliorating cognitive deficits and attenuating tau hyperphosphorylation in AD.

With the increasing density of high voltage transmission systems, the potential risks and hazards of environmental electric fields (EFs) generated by these systems to surrounding organisms is becoming a source of public concern. To evaluate the effect of environmental EFs on plants, we used soybean as a model and systematically evaluated the effect of continuous exposure to different intensities (0 kV/m, 2 kV/m, and 10 kV/m) of power frequency EFs on agronomic characters, yield, nutrient contents, protective enzyme activities, and gene transcription. We found that the effects on soybean were more pronounced when plants were exposed to EF during development (especially at the seedling stage) than when they were exposed at maturity. The functional leaf number, stem diameter, plant dry weight, and pod number were largely unaffected by EF, while the germination rate and protective enzyme activities increased with increasing EF intensity. In plants exposed to low-intensity EF (2 kV/m), some agronomic characters, including chlorophyll content, plant height, and bean dry weight, as well as the soluble sugar and total protein contents, were significantly higher than those of plants exposed to high-intensity EF (10 kV/m) and control plants (0 kV/m). Through transcriptome analysis, we found that 2,977 genes were significantly up-regulated and 1,462 genes were down-regulated when plants were exposed to EF. These differentially expressed genes mainly encode ribosome proteins and related enzymes involved in carbon metabolism pathway, providing a novel perspective for understanding molecular mechanisms underpinning the responses to EF stress in soybean.

Highlights • Prolonged exposure to ELF-EMF has no effect on the behavior of the adult male rats. • Including anxiety/depression like behavior, and spatial/fear learning and memory. • Exposure to ELF-EMF might be safe., Recently, extremely low frequency electromagnetic fields (ELF-EMF) have received considerable attentions for their potential pathogenicity. In the present study, we explored the effects of ELF-EMF on behaviors of adult male rats. Sixty adult male rats were randomly divided into two groups, the sham exposure group and the 50 Hz/100 μT ELF-EMF exposure group. During the 24 weeks exposure, body weight, as well as food and water intake were recorded. Results showed that food and water intake and the body weight of the rats were not affected by the exposure. After 24 weeks exposure, open field test and elevated plus maze were conducted to evaluate the anxiety-like behavior, the tail suspension test and forced swim test were conducted to evaluate depression-like behavior and Morris water maze and fear conditioning tests were used to evaluate the cognitive and memory ability. Exposure to ELF-EMF did not induce any anxiety-like or depression-like behaviors compared with the sham exposure. Moreover, the cognitive and memory ability was not impaired by the ELF-EMF exposure. Furthermore, ELF-EMF exposure did not affect the morphology and histology of the brain. In conclusion, 24 weeks exposure to 50 Hz/100 μT ELF-EMF had no effect on the behaviors of the adult male rats.

The aim of this study was to test whether extremely low frequency electromagnetic fields (ELF EMFs) affect health or not. Here, we constructed a 100-μT/50 Hz electromagnetic field atmosphere. A total of 128 rats were randomly assigned into two groups: the ELF EMF group and the sham group. The ELF EMF group was exposed to 100-μT/50-Hz ELF EMF for 20 h per day for three months; at the same time the other group was exposed to a sham device without ELF EMF. During the three months, the weight was recorded every 2 weeks, and the water intake and food intake of the animals were recorded weekly. The hematologic parameters were detected before and after the exposure, whereas blood chemistry analysis was performed every 4 weeks. The general condition of the exposed rats was not affected by ELF EMF. Compared with the sham group, the hematograms were not significantly altered in the ELF EMF group. Similarly, the blood chemistry (including lipid profile, blood glucose, liver function and renal function of rats) from the ELF EMF group showed no difference compared with rats from the control group during the three months exposure. The present study indicated that short-term exposure of 100-μT/50-Hz ELF EMF may not affect hematograms and blood chemistry in rats.

A comparative study of an outside signal sprinkler (OS), a fluidic sprinkler (FS), and an impact sprinkler (IS) was carried out. The OS, FS, and IS were evaluated individually under indoor experimental conditions. Water distribution evaluations were measured under four operating pressures at a 1.5-m nozzle height (above the ground). Approximately 36 individual trials were performed. The results show that the discharge coefficient of the OS and FS was slightly larger than that of the IS. The water distribution profiles of the OS, FS, and IS were parabola-shaped, ellipse-shaped, and doughnut-shaped, respectively. The wetted radius for the OS was similar to the wetted radius of the FS and was 8.7–12 % less than the IS. An accurate and simple empirical equation for the wetted radius of OS and FS is reported. Additionally, equations of water application rate, with regard to distance from the sprinklers, are given. The average coefficients of determination for the OS, FS, and IS were 91.8, 89.2, and 79.1 %, respectively. Individual spray sprinkler water distributions were mathematically overlapped to calculate the combined uniformity coefficient (CU). Maximal combined CUs of 80.88, 80.92, and 78.12 % were found for the OS, FS, and IS, respectively. Both the OS and FS were found to have greater CU values than the IS, which indicates that the OS and FS provided a better water distribution pattern than the IS at low pressure.

Extremely low frequency magnetic field (ELF-MF), as a ubiquitous ecophysiological factor, has been determined to influence the health of human and animals worldwide. In this study, we focused on the effects of ELF-MF on growth performance and digestive enzyme activity in juvenile tilapia, Oreochromis niloticus. Totally 450 fish were exposed to ELF-MF (50 Hz; 0, 30, 100, 150 and 200 μT) for 30 days, respectively. The effects on growth and digestion were monitored on the 10th, 20th, and 30th day after induction (immediate effect), as well as 20th day after cessation of exposure (delayed effect). The activities of pepsin and intestinal protease of tilapia were significantly decreased after exposure in certain intensities of ELF-MF, but recovered when the ELF-MF exposure was removed 20 days later. Similar effects were also observed in the growth parameters, moreover interestingly, the specific growth rate (SGR) even represented a compensatory growth. To our knowledge, the present research provides the first determination that a certain extent of ELF-MF exposure could inhibit the growth and digestion of fish, and cause compensatory restorations after being removed upon a time.

A 50-Hz magnetic field (MF) is a potential health-risk factor. Its effects on the cardiovascular system have not been fully investigated. This study was conducted to explore the effects of long-term exposure to a 50-Hz MF on the cardiovascular system. In the study, an exposure system was constructed, and the distribution of the 50-Hz MF was determined. Sixty-four Sprague-Dawley (SD) rats were exposed to a 50-Hz MF at 100 μT for 24 weeks, 20 h per day, while another 64 rats were sham exposed. During the exposure, blood pressure was measured every 4 weeks. After 24 weeks, echocardiography, cardiac catheterization and electrocardiography were performed. Moreover, heart and body weight were recorded, and haematoxylin–eosin staining and real-time PCR were conducted. The results showed that compared with the sham group, exposure to a 50-Hz MF did not exert any effects on blood pressure, pulse rate, heart rate or cardiac rhythm. Furthermore, echocardiography and cardiac catheterization showed that there were no significant differences in the cardiac morphology or haemodynamics. In addition, histopathological examination showed that exposure to a 50-Hz MF had no effects on the structure of the heart. Finally, expression of the cardiac hypertrophy–related genes did not show any significant differences between the 50-Hz MF exposure group and the sham group. Taken together, in SD rats, exposure to a 50-Hz/100 μT MF for 24 weeks did not show any obvious effects on the cardiovascular system.

To improve the tracking accuracy and stability of an optic-electronic target tracking system, the concept of generalized synergic target and an algorithm named error-space estimate method is presented. In this algorithm, the motion of target is described by guide data and guide errors, and then the maneuver of the target is separated into guide data and guide errors to reduce the maneuver level. Then state estimate is implemented in target state-space and error-space respectively, and the prediction data of target position are acquired by synthesizing the filtering data from target state-space according to kinematic model and the prediction data from errorspace according to guide error model. Differing from typical multi-model method, the kinematic and guide error models work concurrently rather than switch between models. Experiment results show that the performance of the algorithm is better than Kalman filter and strong tracking filter at the same maneuver level.

With the development and widespread use of electromagnetic field (EMF) technology, recent studies are focusing on the effects of EMF on human health. Recently, extremely low frequency electromagnetic fields (ELF-EMF) have been studied with great interest due to their possible effects on Alzheimer's disease (AD). The objective of the present study was to investigate the interaction between ELF-EMF exposure and memory impairment in rats.Twenty healthy male Sprague Dawley (SD) rats were randomly divided into two groups (n = 10). Animals were exposed to 100 μT/50 Hz ELF-EMF or subjected to sham exposure when 12 weeks old. After 12 weeks, the Morris water maze (MWM) was used to test the changes in cognitive and memory ability. Amyloid-beta (Aβ) content in cortex, hippocampus and plasma were measured by ELISA assays. The morphology of neuron was detected by HE staining.After exposure, the body weight of rats showed no difference compared with the control group. The application of ELF-EMF did not induce any cognitive and memory impairment compared with the sham-exposure group. The determination of Aβ showed no significant change between the two groups, and there was no histological change in ELF-EMF exposure group.The present study indicated that short-term exposure of 100 μT/50 Hz ELF-EMF had no effects on cognition and memory of rats, and did not alter the expression of Aβ and the neuron morphology. However, more comprehensive studies are still required to elucidate the possible effects and underlying mechanisms of ELF-EMF exposure on living organisms.

To improve spatial target tracking precision and stability of mobile photoelectric tracking equipment, state estimation and prediction of the target with high accuracy is necessary. An improved error-space estimate method with time correction is presented to estimate and predict the state of spatial target accurately for the mobile tracking equipment. By the method, measurement without satisfying validity and veracity is obtained by scanning, and time error is calculated and corrected with correlation analysis of actual measurement and offline estimation sequence of spatial target orbit. From new offline estimation and actual measurement, estimation of target state with high accuracy is obtained by ordinary error-space estimate method to guide the tracking system to perform steadily. Experiment results show that comparing with the spatial target state estimation without time correction, the one of the method presented is with higher accuracy, and estimation error increases more slowly along with prediction steps.