两种智能优化算法在交通控制应用中的对比研究

城市交通系统是一个随机性很强的、复杂的巨型系统。本文提出了2种区域智能交通控制的模型与算法分别是：将遗传算法与混沌映射结合,提出混沌遗传算法（C-GA）;将粒子群算法分别与混沌映射构造混沌粒子群算法（C-PSO）、模拟退火粒子群算法（Sa—PSO）。仿真结果表明,各个优化算法具有较强的鲁棒性、自适应性和自学习性,都能高效地解决区域交通控制信号优化配时问题且较传统固定周期控制方法能较好地减少车辆的平均延误。     

改进PSO算法在中密度纤维板热压机压力PID控制优化中的应用

针对中密度纤维板生产过程中热压压力控制存在的大惯性、纯滞后和非线性问题,提出具体的解决方法。运用PID-FUZZY复合控制方式,采用改进PSO算法优化压力PID控制,提出了基于PSO优化算法整定PID控制器参数的设计方法,实现对热压过程的优化控制。通过仿真实验和结果分析得出,采用改进PSO算法优化压力PID控制具有稳定性好、超调量少、震荡现象少等优势特点。     

基于PSO-BMAC协调算法的永磁同步电动机直接转矩控制

提出一种将PSO和BMAC相结合的控制算法,用于永磁同步电动机的直接转矩控制。用PSO算法控制转速环,以及基于PSO和BMAC相结合的算法控制器来取代传统DTC系统中的磁链控制器和转矩控制器。在MAT-LAB仿真环境下,分别对传统DTC系统,基于PSO算法的DTC系统和基于PSO-BMAC算法的DTC系统进行仿真比较。实验结果表明：运用该控制方法的系统响应快,磁链理想,鲁棒性好,比前两种DTC控制具有更好的动、静态性能。     

拉曼光谱结合光谱特征区间筛选算法快速定量鉴别植物调和油品质

本研究提出了一种基于拉曼光谱与光谱特征区间筛选算法实现植物调和油中高价值植物油含量快速定量检测的方法。首先,将粒子群优化（particle swarm optimization,PSO）算法与灰狼优化（grey wolf optimization,GWO）算法融合构建混合智能优化算法,即PSOGWO算法。其次,将PSOGWO与组合移动窗口（combined moving window,CMW）策略结合构建新型的拉曼光谱特征区间筛选算法,即PSOGWO-CMW算法。然后,将玉米油（corn oil,CO）和特级初榨橄榄油（extra virgin olive oil,EVOO）以不同比例配制为CO-EVOO植物调和油,并采集其拉曼光谱。将拉曼光谱输入偏最小二乘回归、PSO-CMW、GWO-CMW和PSOGWO-CMW模型预测EVOO含量,并比较建模效果。结果表明,PSOGWO-CMW模型具有最佳的预测性能。采用本方法与气相色谱-质谱法分别检测真实的CO-EVOO植物调和油样本中EVOO含量,结果表明两者的检测性能无显著差异。本方法快速、准确,亦可用于其他植物调和油中高价值植物油含量的快速...     

基于改进PSO算法的PID优化用于黑液液位控制

制浆过程中碱回收蒸发工段黑液液位控制直接影响着黑液浓度和蒸发效率。针对黑液液位非线性、大时滞及时变性的特点,传统PID方法控制精度较低,使用标准粒子群算法可以优化PID参数,提高精度,但是收敛速度慢,整定时间长。针对这些问题,采用改进的粒子群算法来整定PID参数,通过动态调整惯性因子和加速因子,以及改进收敛准则等方法来提高粒子群算法的全局寻优能力和收敛速度,并在MATLAB/SIMULINK仿真实验平台上,比较了传统PID方法、标准PSO算法和改进PSO算法对黑液液位的控制效果,结果表明改进PSO算法优化的PID控制缩短了调节时间,降低了超调量,说明改进粒子群算法优化后的黑液液位PID控制具有更快的响应速度和更好的鲁棒性,有效地提高了控制质量。     

基于新型智能算法的多自由度机器人控制系统研究

针对多自由度机器人在控制过程中,存在高耦合、参数不确定性和外部扰动等问题,提出一种基于新型智能算法（自抗扰控制算法）的多自由度机器人串联控制系统。首先,对多自由度机器人建立其控制的直流力矩电机的数学模型;其次,设计新型只能控制算法;最后,以多自由度机器人为控制对象应用与提出的新型智能控制算法和传统的控制算法进行仿真比较。结果表明,所提控制算法具有良好的动态性能和不确定扰动鲁棒性,证明了所提方法的有效性。     

基于遗传-粒子群混合算法的测试数据自动生成

针对传统遗传算法（GA）容易产生早熟收敛和易陷入局部最优解的问题,提出了一种基于遗传-粒子群混合算法（GA-PSO）的软件测试数据自动生成算法：以粒子群优化算法（PSO）为主线,按PSO算法中标准的速度和位置更新,将GA算法的筛选、交叉、变异与PSO算法的自动更新特征结合在一起,使所有测试数据在局部区域中再次寻找最优值,从而避免了过早收敛,改进了搜索最佳值的能力.仿真实验表明：遗传-粒子群混合算法具有更快的收敛速度,保持了种群的多样性,提高了全局搜索能力.     

改进PSO算法在中密度纤维板热压机压力模糊控制优化中的应用

针对中密度纤维板生产过程中热压压力控制存在的大惯性、纯滞后和非线性问题,提出具体的解决方法。运用模糊控制理论,建立中密度纤维板热压机模糊控制器模型,采用改进PSO算法优化压力模糊控制规则的方法,建立热压压力模糊控制查询表,从而实现对热压过程的优化控制。通过仿真实验和结果分析得出,采用改进PSO算法优化压力模糊控制规则具有稳定性好、超调量少、震荡现象少等优势特点。     

基于PSO的BP-PID碾米机组控制系统优化

针对当前碾米机组之间流量稳定性差,单机效率低、碾白不均衡或过碾致碎米增加等问题,提出了基于粒子群算法(PSO)优化BP-PID控制的碾米机组控制系统;运用多机协同优化技术,通过调控在线碾米单机的碾除糠粉比例及其匹配的运行参数实现流量平衡控制;通过BP神经网络训练PID控制器的参数建立碾米机组调控数学模型,并引入PSO对BP神经网络的性能进行优化。仿真试验表明,经PSO优化的控制系统的响应速度更快,其稳态精度有所提高,且具有良好的控制效果。     

置换蒸煮锅温差控制策略研究

为提高制浆过程中置换蒸煮系统在扰动和模型失配条件下的控制精度与鲁棒性,本课题基于置换蒸煮锅温差控制系统仿真模型,提出了一种基于模糊控制算法与粒子群优化算法（Particle Swarm Optimization,PSO）的置换蒸煮系统温差自适应PID控制方法。首先基于粒子群优化算法设置PID控制器参数的初始值,再利用模糊算法实现PID参数自整定,最后将控制效果与传统PID控制器以及模糊PID控制器进行对比。结果表明,在单一工况下,PSO-模糊PID控制器的综合性能最好,调节时间最短,超调量最低,有效保持蒸煮立锅内药液温度的一致性;针对压力阶跃扰动和模型失配,PSO-模糊PID控制器抗干扰性能更强,总体超调量更低,调节时间更短,具有良好的鲁棒性和自适应性。     

Behavioral changes in dairy cows with metritis in seasonal calving pasture-based dairy system

The aims of this study were to determine changes in lying and rumination behavior of transition dairy cows that were healthy or affected by metritis during the autumn and spring calving season in a temperate climate and determine the effect of some weather variables (precipitation and heat stress) on these behaviors. A total of 103 multiparous cows were monitored during the autumn (February to April) and spring calving season (July to October) from 10 d before to 10 d after calving. Cows were chosen retrospectively by diagnosis of metritis [autumn season, (n = 11); spring season, (n = 13)] or as healthy [autumn season, (n = 25); spring season, (n = 25)] based on vaginal discharge characteristics evaluated during the first 10 days in milk. In all animals, electronic data loggers recorded lying (Hobo Pendant G Acceleration, Onset Computer Corp.) and rumination behavior (Hi-Tag rumination monitoring system, SCR Engineers Ltd.) during the study period. We included precipitation level (>1 mm/d = with rain, and ≤1 mm/d = without rain) and heat stress [no heat stress = temperature-humidity index (THI) < 68 vs. heat stress = THI ≥ 68] as weather factors that may have affected lying and rumination behavior during the spring and autumn season in a temperate climate, respectively. Metritis during the spring calving season was associated only with longer lying times (≥1.3 h/d) after calving. During the autumn calving season cows with metritis lay down longer the day of calving (~2.1 h/d) and had fewer lying bouts of longer duration during the prepartum period compared with healthy cows. Rumination time did not differ by health status during the spring calving season, whereas cows with metritis during autumn ruminated 30, 21, and 24 min/d less than healthy cows during the prepartum, calving, and postpartum period, respectively. Precipitation and heat stress were associated with decreased daily lying and rumination time in sick cows. Our results indicate that differences in lying and rumination behavior depended on the metritis status, and support the idea that weather factors such as rainfall or heat stress requires to be considered in analyses of transition cow behavior in seasonal calving pasture-based dairy systems.     

恩施烟区雪茄烟BESNOH382引种播种期和移栽期试验初报

为了探讨雪茄烟BESNOH382的引种栽培技术,在恩施州进行了播种期和移栽期试验研究。结果表明,2月28日至3月8日播种是恩施来凤种植雪茄烟的最适宜播种期,4月30日至5月10日是最适宜移栽期。此为该品种雪茄烟在当地的推广应用提供了关键技术参考。     

论D301A型自动缫丝机感知器灵敏度测定项目的适用性及建议

通过实践和理论分析，阐明感知时间和感受时间的测定项目不适用于Ｄ３０１Ａ型自动缫丝机，同时提出探索添绪时间作为其测定项目的建议。     

织物感应静电的高压测量法

本文从测量仪器的原理和使用方法方面介绍静电值、半值时间的测量方法和所采取的技术路线,对感应式静电仪进行了较为深入的探讨。     

Coagulation Kinetics of High Pressure Treated Acidified Milk Gel for Preparation Chhana (An Indian Soft Cottage Cheese)

Chhana, an Indian cottage cheese, is one of the most popular heat-acid coagulated milk products. It forms the base material for a variety of milk-based sweets. Application of high pressure treatment for denaturation of milk protein has successfully been carried out. In the present study, high pressure in the range of 200–400 MPa for 0 to 100 min at coagulation temperature of 30–70°C was applied at constant acidity of milk-acid mixture in order to study the coagulated milk gel properties for preparation of chhana. The experiments were conducted using a central composite rotatable experimental design. Linear and non-linear regression equations, using the coded values of the independent variables were developed to study the effect of process variables on coagulated gel properties viz., lag time, mean coagulation rate and inflexion time. The optimum values of independent variables corresponding to minimum lag time, maximum coagulation rate and minimum inflexion time was obtained were high pressure - 280 MPa; pressurization time - 47 min; and coagulation time - 52°C. At this optimum condition of independent variables the lag time, mean coagulation time and inflexion time were 0.0028 min, 3.87 min, and 5.19 min, respectively.     

Implications of prolonged milking time on time budgets and lying behavior of cows in large pasture-based dairy herds

In large Australian pasture-based dairy herds, it is common for the time taken to milk a herd of cows to be up to 4 h. Cows are collected from the paddock as a group, wait in turn in the dairy yard to be milked, and then return individually to the paddock or feed pad immediately after leaving the milking parlor. In such herds, we previously found a consistent milking order, resulting in some cows being regularly away from pasture for several hours per day more than others. Increased time away from pasture may affect the time budgets of cows because of decreased opportunity for grazing or lying down. Lying behavior is a high-priority behavior for cows, and the duration of lying has been used as an important measure of their welfare. We applied activity monitors for 7 d to 15 cows toward the beginning and 15 cows toward the end of the milking order in 10 dairy herds milking 500 to 730 cows as a single group to understand the effect of extra time spent in the dairy on lying behavior. Study cows typically produced 6,000 to 8,000 L in a 300-d lactation on rotary dairy platforms with 40 to 80 units, being fed 2.5 to 6 kg of grain mix in the milking parlor daily, with the rest of the diet being supplied as pasture or forage provided in the pasture or close to the exit of the dairy. Over the 10 farms, 1,948 cow-days were available for analysis. The furthest paddocks on each farm were 1.8 to 3.5 km walking distance from the dairy. A wide range of steps were taken each day, ranging from 1,705 to 15,075 (mean = 5,916). The main predictor of the number of steps was the farm on which the cows were located. Cows that spent less than an hour waiting to be milked (and would be unlikely to have their ability to lie down affected by the milking process) laid down for a mean of 9.8 h/d. Steps walked and delay in the dairy waiting to be milked were both significantly associated with lying time, but the effect was not large. A regression model accounting for the waiting time at the dairy, steps taken, cow age, and farm was used to investigate the relationship with daily lying time. For every 1,000 steps, lying time reduced by 0.49 h; however, the number of steps explained only 1% of the variation in lying time. For every hour increase in waiting time at the dairy, lying decreased by approximately 14 min, but this explained only 14% of the variation in lying. We concluded that milking time durations of 2 to 4 h, common in large Australian pasture-based dairy herds, did not significantly affect the time budget for lying of individual cows in our study herds. Whereas the effect of long milking times does not appear to be a major risk to animal welfare in terms of lying time, the effect on cow health and production warrants further investigation.     

胶印机输墨系统的动态性能研究

采用计算机仿真的方法对胶印机输墨系统的动态性能进行了研究.通过对输墨系统的离散化处理,实现了连续输墨系统的计算机仿真计算,建立了求解响应时间和稳定时间的数学模型,并深入研究了系统的稳定时间与图文覆盖率的关系.计算结果表明,输墨系统的响应时间相对于系统是固定的,与印版上的图文分布无关,系统的稳定时间随着图文覆盖率的减小而明显增长.     

原辅料对面包面团调制时的影响

通过粉质仪试验,分析在面包制作过程中,各种不同原辅料在不同的添加量时对面团特性产生不同的影响,调整配比可以改善面团的工艺性能,以利于面包的制作,提高产品质量。     

Ovulation timing and conception risk after automated activity monitoring in lactating dairy cows

Using 1 market-available activity monitor, 3 experiments were conducted in dairy cows to determine timing of ovulation, compare within-herd conception risk of cows inseminated based on activity monitors versus timed artificial insemination (AI), and determine conception risk of cows inseminated at various intervals after achieving an activity threshold. In experiment 1, ovaries were scanned every 3 h by transrectal ultrasonography to determine the time of ovulation beginning 14 ± 0.5 h after the achieved activity threshold (n = 132) or first standing event (n = 59), or both (n = 59). Progesterone at the first ovarian scan (0.1 ± 0.01 ng/mL) and ovarian structures [1 or 2 preovulatory-sized follicles (16.5 ± 0.2 mm)] confirmed that 88.6% of cows identified by activity were in estrus. The remaining 15 cows (11.4%) with a corpus luteum and elevated progesterone concentration (5.3 ± 0.5 ng/mL) were classified as false positives. The average interval from first standing event to ovulation (n = 59) differed slightly from the interval after the achieved threshold (26.4 ± 0.7 vs. 24.6 ± 0.7 h, respectively). In 97 cows fitted with activity monitors, that interval was 25.7 ± 0.4 h. In experiment 2, the conception risk in 394 cows in 1 herd fitted with activity monitors was compared with that of 413 cows submitted to a timed AI program through 3 AI services. Days to first AI were reduced in cows fitted with activity monitors, and conception risk after activity threshold was less than that for timed AI at first service because of differing days in milk at first AI. Both median and mean days to pregnancy, however, were reduced in activity-group cows by 10 and 24 d, respectively, compared with timed AI cows. In experiment 3, 4,019 cows in 19 herds were inseminated after achieving the activity threshold. Conception risk was determined for cows inseminated at various intervals after the achieved activity threshold. A curvilinear conception risk curve peaked at 47.9% for primiparous cows inseminated between 13 and 16 h, whereas conception risk in multiparous cows was steady at 34% through 12 h and decreased thereafter. These experiments demonstrate that time of ovulation after activity threshold closely resembles the time of ovulation after first standing estrus. Time of insemination up to 12 h after the activity threshold produced similar conception risks for multiparous cows, whereas intervals shorter than 13 and greater than 16 h in primiparous cows seemed to compromise their conception risk. Although conception risk may not be improved at individual inseminations after achieving an activity threshold, the rate of achieving pregnancy is hastened. Activity monitors can accurately predict ovulation and time of AI.     

Stocking density,milking duration,and lying times of lactating cows on Canadian freestall dairy farms

Lying time is an important measure of cow comfort, and the lying behavior of dairy cattle can now be recorded automatically with the use of accelerometers. To assess the effect that stall stocking density and the time that cows spend away from the home pen being milked has on the lying behavior of Holstein cattle, a total of 111 commercial freestall dairy farms were visited in Canada. Accelerometers were used to automatically record the lying behavior of 40 focal cows per farm. Total duration of lying, lying bout frequency, and the mean duration of lying bouts were calculated. Pen population was the total number of cows in the pen. To calculate stall stocking density (%) the number of cows in the pen and the number of useable stalls were counted and multiplied by 100, and the length × width of the pen was divided by the number of cows in the pen to calculate area/cow (m²). Time away from the pen per day was recorded from when the first cow in each pen was taken out of the home pen for milking until the last cow returned to the home pen after milking, and this time was multiplied by daily milking frequency. The median value for lying duration at the farm level was 10.6 h/d, with 10.5 lying bouts/d, and a median lying bout duration of 1.2 h. Stall stocking density ranged from 52.2 to 160.0%, with very few farms (7%) stocking at greater than 120%. Although stall stocking density was not significantly correlated with lying behavior, the results showed that no farm with stocking density greater that 100% achieved an average herd lying duration of 12 h/d or higher, whereas 21.6% of farms with a stocking density of 100% or less did achieve the target lying time of ≥12 h/d, as recommended by the Canadian Code of Practice (χ² = 4.86, degrees of freedom = 1). Area/cow (m²) was not correlated with any aspect of lying behavior, but regardless of space per cow, pen population was correlated with daily frequency and duration of lying bouts. As the number of cows in the pen increased, lying daily bout frequency increased (correlation coefficient = 0.24) and lying bout duration decreased (correlation coefficient = −0.30). Lying behavior was affected by the time the cows were away from the pen being milked. When cows were away from the pen for longer than 3.7 h/d, no farm achieved the recommended herd median lying time of 12 h/d or longer. These results suggest that providing 1 stall for each cow in the pen and minimizing time away from the pen are important factors if cattle are to achieve the recommended daily lying duration of 12 h/d.