多平台异构信息融合的航空目标跟踪算法

该文以高空无人机(UAV)飞艇载双光电传感器,无人机载两坐标雷达对航空目标的精确定位跟踪为研究背景,针对参与融合的传感器均无法独立获得目标位置信息导致传统点迹关联、定位方法失效等问题,提出一种基于多平台异构信息融合的航空目标跟踪算法。首先,在坐标系转换的基础上提出基于角度-距离两级点迹关联算法,从而实现多传感器量测关联。其次,提出基于线面交汇融合定位算法,通过最小二乘法、交汇点投影、距离最近点解算及同源数据压缩确定目标的航迹起始位置。在此基础上,利用空基多平台侦察的异构信息,结合传统无迹卡尔曼滤波器(UKF)设计扩维UKF对航空目标进行跟踪。仿真结果表明,该算法实现了对航空高速目标的高精度跟踪。

Gray comprehensive assessment and optimal selection of water consumption forecasting model

A comprehensive assessing method based on the principle of the gray system theory and gray relational grade analysis was put forward to optimize water consumption forecasting models. The method provides a better accuracy for the assessment and the optimal selection of the water consumption forecasting models. The results show that the forecasting model built on this comprehensive assessing method presents better self-adaptability and accuracy in forecasting.

Analysis and evaluation on pressure fluctuations in air dense medium fluidized bed

Pressure fluctuations contribute to the instability of separation process in air dense medium fluidized bed, which provides a high motivation for further study of underlying mechanisms. Reasons for generation and propagation of pressure fluctuations in the air dense medium fluidized bed have been discussed.Drift rate and collision rate of particles were employed to deduce the correlation between voidage and pressure fluctuations. Simultaneously, a dynamic pressure fluctuation measuring and analysis system was established. Based on frequency domain analysis and wavelet analysis, collected signals were disassembled and analyzed. Results show gradually intensive motion of particles increases magnitudes of signal components with lower frequencies. As a result of violent particle motion, the magnitude of real pressure signal's frequency experienced an increase as air velocity increased moderately. Wavelet analysis keeps edge features of the real signal and eliminates the noise efficaciously. The frequency of denoised signal is closed to that of pressure signal identified in frequency domain analysis.

Measurement and correlation of solubility of meropenem trihydrate in binary(water＋acetone/tetrahydrofuran) solvent mixtures

The solubility of meropenem trihydrate in water+acetone mixtures and water+tetrahydrofuran mixtures were determined from T=(278.15 to 303.15) K by static method under atmospheric pressure.Effects of solvent composition and temperature on solubility of meropenem trihydrate were discussed.To extend the applicability of the solubility data,experimental solubility data in two kinds of binary solvent mixtures were correlated by the Apelblat equation and NIBS/Redlich–Kister model.It was found that the two models could satisfactorily correlate the experimental data and the Apelblat equation could give better correlation results.

Measurement and Correlation for Solubility of 2-Chloro-5-chloromethylpyridine in Different Solvents

2-Chloro-5-chloromethylpyridine is a crucial intermediate of pesticides.Its solid-liquid equilibrium data will provide essential support for industrial design and further theoretical studies.The solubilities of 2-chloro-5-chloromethylpyridine in water,methanol,ethanol,ethyl acetate,acetone,trichloromethane and toluene at different temperatures were measured using the synthetic method by a laser monitoring observation technique. The solubility data were correlated with the modified Apelblat equation and Wilson equation.The calculated values were in good agreement with the experimental values.

Genetic Diversity and Interrelationship Among Mulberry Genotypes

Fourteen morphometric traits were used to examine the genetic divergence of 25 mulberry （Morus spp.） genotypes from varied agroclimatic conditions of India. Wide variation was observed for all the traits. The genotypes irrespective of their place of collection were grouped into 10 different clusters. Seven accessions, that is, Baragura-2, Gorabandha-2, Kalimpong, Herbertpur, Kollegal, Resham majri-7, and UP-14 each a cluster of unique entries will be of useful for genetic resources. Nevertheless, the correlation and path analysis suggest the direct selection of lamina length, fresh leaf weight, leaf area, and single leaf weight will be rewarding for mulberry leaf yield improvement.

The built environment correlates of objectively measured physical activity in Norwegian adults:A cross-sectional study

Background: Built environments that are designed to provide accessible, attractive, and convenient locales promote regular physical activity(PA).Norway has great variability in its geographic, natural, and built environment features. Urban areas have well-developed built environment features, whereas the rural areas are less walkable and this may influence the mode of transport. In general, active transport is more common in urban centers. Further, public transportation is more developed in urban areas, whereas motorized transport may be more widespread in the rural areas. Despite this, in Sogn & Fjordane, a rural county in western Norway, high PA levels are frequently observed. Thus, the aims of this study were to(1) explore perceived built environment features and characterize their associations with objectively measured PA levels in Norwegian adults and(2) explore the differences in these correlates between Sogn & Fjordane and the rest of Norway.Methods: In this cross-sectional study, participants used questionnaires to rate perceptions of their built environments, and their PA was objectively measured for 7 consecutive days using the Acti Graph GT1 M accelerometer. There were 972 Norwegian adults who were included in the study. The average age was 46.9 ± 6.5 years and 43.8% of participants were men. Data were analyzed using multiple linear regression.Results: Total PA and moderate-to-vigorous physical activity(MVPA) were both associated with perceived walkability, the community perception score, and active transport for commuting(all p ≤ 0.004). We also observed geographic-area-specific associations: the community perception score was negatively associated with total PA and MVPA in the rest of Norway(p ≤ 0.012) but not in Sogn & Fjordane. Public transport for commuting was positively associated with MVPA in Sogn & Fjordane(p = 0.03) but not in the rest of Norway.Conclusion: Total PA level and MVPA were associated with built environment factors, such as perceptions of community, perceived walkability,and engaging in active transport for commuting. Geographic differences in the PA correlates were observed, and thus, locally customized environmental population approaches aimed at increasing PA levels may be essential complements to individual behavior and lifestyle strategies.Further, objective measures of Norwegian built environments, such as geographic information system data, and validated walk-and bike-scores would advance the field.

Non-contact measurement and multi-objective analysis of drilling temperature when drilling B_4C reinforced aluminum composites

Non-contact measurements of machining temperatures were performed with optical pyrometer when drilling particle（B4C） reinforced metal matrix composites（MMCs） with different drills. The effect of particle content, cutting speed, feed rate and tool material on the maximum drilling temperature was investigated. The drilling parameters were optimized based on multiple performance characteristics in terms of the maximum cutting temperature and tool wear. According to the results, the most influential control factors on the cutting temperatures are found to be particle fraction, feed rate and interaction between the cutting speed and particle content, respectively. The influences of the cutting speed and drill material on the drilling temperature are found to be relatively lower for the used range of parameters. Minimum cutting temperatures are obtained with lower particle fraction and cutting speed, with relatively higher feed rates and carbide tools. The results reveal that optimal combination of the drilling parameters can be used to obtain both minimum cutting temperature and tool wear.

A new support vector machine based multiuser detection scheme

In order to suppress the multiple access interference (MAI) in 3G, which limits the capacity of a CDMA communication system, a fast relevance vector machine (FRVM) is employed in the multiuser detection (MUD) scheme. This method aims to overcome the shortcomings of many ordinary support vector machine (SVM) based MUD schemes, such as the long training time and the inaccuracy of the decision data, and enhance the performance of a CDMA communication system. Computer simulation results demonstrate that the proposed FRVM based multiuser detection has lower bit error rate, costs short training time, needs fewer kernel functions and possesses better near-far resistance.

Measurement and correlation of solid–liquid phase equilibria for binary and ternary systems consisting of N-vinylpyrrolidone, 2-pyrrolidone and water

The solid–liquid equilibria(SLE)for binary and ternary systems consisting of N-Vinylpyrrolidone(NVP),2-Pyrrolidone(2-P)and water are measured.The phase diagrams of NVP(1)+2-P(2),NVP(1)+water(2),NVP(1)+2-P(2)+1 wt%water(3)and NVP(1)+2-P(2)+2 wt%water(3)are identified as simple eutectic type with the eutectic points at 263.75 K(x_(1E)=0.5427),251.65 K(x_(1E)=0.3722),260.25 K(x_(1E)=0.5031)and256.55 K(x_(1E)=0.4684),respectively.The phase diagram of 2-P(1)+water(2)has two eutectic points(x_(1E)=0.1236,T_E=259.15 K and x_(1E)=0.7831,T_E=286.15 K)and one congruent melting point(x_(1C)=0.4997,T_C=303.55 K)because of the generation of a congruently melting addition compound:2-P·H_2O.The ideal solubility and the UNIFAC models were applied to predict the SLE,while the Wilson and NRTL models were employed in correlating the experimental data.The best correlation of the SLE data has been obtained by the Wilson model for the binary system of NVP+2-P.The UNIFAC model gives more satisfactory predictions than the ideal solubility model.

The Association between Lifestyle, Anthropometric Measurements, and Obesity in University Students

Nutritional Assessment is the process of identifying characteristics known to associated with nutrition problems. Certain foods with chemical additives disguised as food can cause muscle and joint pain associated with arthritis, gout, fibromyalgia, obesity, cancer and others. Avoiding these foods can reduced inflammation, thus prevent obesity, cancer, and another disease. The target of the study was to find a relation between food type, anthropometric parameters and obesity-related diseases for university students in CoUege-Al Leith-Umm al-Qura University, Saudi Arabia. The purpose is to identify populations （100 subjects women, aged： 17-30 year, using questionnaire） who are malnourished or at nutritional risk. Participants were divided into normal-weight and obese groups. The different methods are used to collect data including： 1. Anthropometric, 2. Dietary： Nutritional History （Current Intake）, 3. FFQ （Food frequency questionnaire）. There is a significant association between certain food type, anthropometric parameters, obesity as well as other diseases including （vitamin D deficiency, kidney problems, bone pain, general weakness, thyroid problems, infertility.

Grey correlational and SSR analyses of cotton hybrids

Ten upland cotton strains exhibiting 3 fiber quality traits and 8 yield traits, were grown for two years in an investigation of the correlation between grey relational analysis （GRA） and genetic identity in heterosis of cot- ton hybrid. The aim was to establish the optimal approach for heterosis prediction and parent selection. Plant traits data were collected and analyzed for GRA. In addition, 72 simple sequence repeat （SSR） markers were examined and 148 polymorphisms were detected. Correlation analysis of GRA, genetic identity, Ft fiber quality and yield heterosis was conducted. Significant differences were observed between the two analytic methods, whereas compa- rable predictions were given for yield heterosis. GRA for yield exhibited slightly higher correlation than genetic identity analysis, with a correlation coefficient of 0.49. GRA and genetic analysis exhibited overlapping yet dis- tinct advantages in heterosis prediction. Therefore, these analytical methods should be integrated to achieve the op- timal heterosis prediction and parent selection.

海上目标多源轨迹数据关联综述

船舶自动识别系统、船舶远程识别与跟踪系统、卫星导航定位系统、导航雷达、星载雷达等海上目标监控系统互相补充,极大地增加了海上移动目标监控的广度和质量。然而,同一个移动目标在不同系统中具有不同的标识和轨迹,需要进行有效的数据融合,关联多源轨迹数据,建立各系统中移动目标的对应关系,才能形成统一的海上态势,为移动目标跟踪、轨迹数据挖掘等提供支持。本文介绍和总结了海上目标多源轨迹的常见数据源;剖析与比较了可用于移动轨迹数据关联的最近邻、概率数据关联、联合概率数据关联和多假设跟踪4种量测/航迹关联方法,和基于统计方法或模糊数学的2类航迹/航迹关联方法,以及相关工作进展;总结了常见的算法评估方式;最后讨论了现有方法适用场景问题,及其进一步的研究方向。

Long-term field measurement and analysis of the natural wind characteristics at the site of Xi-hou-men Bridge

In order to investigate the wind characteristics of coastal areas of China, a long-term field measurement of natural wind was carried out. Based on the field measurement results, this paper presents the natural wind characteristics of typhoons and strong monsoons at the site of Xi-hou-men Bridge, including mean wind speed, mean wind direction, mean wind elevation angle, turbulent intensity, gust factor, turbulence integral length scales, power spectrum of wind speed and spatial correlation of gusty wind, the profiles of mean wind speed and turbulent intensity, etc. The correlation among wind characteristics is analyzed in detail, and the similarities and differences of wind characteristics between typhoons and monsoons are analyzed. These results can pro- vide detailed wind characteristics of coastal areas of China.

Spatial pyramidal cross correlation for particle image velocimetry

A spatial pyramidal cross-correlation based on interrogation area sub-division is introduced to improve the measurement resolution in particle image velocimetry(PIV). The high-resolution velocity can be achieved with a velocity prediction model via coarse cross-correlation. The prediction formula is deduced from the frequency response of the moving average(MA). The performance of this method was assessed using synthetically generated images of sinusoidal shear flow, two-dimensional vortical cellular flow, and homogeneous turbulence. A real PIV experiment of turbulent boundary layer was used to evaluate the new method. The results indicate that the spatial pyramid cross-correlation can robustly increase the spatial resolution.

Band structure reconstruction across nematic order in high quality FeSe single crystal as revealed by optical spectroscopy study

We perform an in-plane optical spectroscopy measurement on high quality FeSe single crystals grown by a vapor transport technique. Below the structural transition at Ts - 90 K, the reflectivity spectrum clearly shows a gradual suppression around 400 cm-1 and the conductivity spectrum shows a peak at higher frequency. The energy scale of this gap-like feature is comparable to the width of the band splitting observed by ARPES. The low-frequency conductivity consists of two Drude components and the overall plasma frequency is smaller than that of the FeAs based compounds, suggesting a lower cartier density or stronger correlation effect. The plasma frequency becomes even smaller below Ts which agrees with the very small Fermi energy estimated by other experiments. Similar to iron pnictides, a clear temperature-induced spectral weight transfer is observed for FeSe, being indicative of strong correlation effect.