关于QL-、D-蕴涵的分配性方程的解

研究了[r→（t∧s）]≡[（r→t）∧（r→s）],[r→（t∨s）]≡[（r→t）∨（r→s）],[（p∧q）→r]≡[（p→r）∨（q→r）],[（p∨q）→r]≡[（p→r）∧（q→r）]4个分配性方程,它们在模糊集理论中的形式分别是I（r,T₁（t,s））=T₂（I（r,t）,I（r,s））,I（r,S₁（t,s））=S₂（I（r,t）,I（r,s））,I（T₁（p,q）,r）=S₁（I（p,r）,I（q,r））,I（S₁（p,q）,r）=T₁（I（p,r）,I（q,r））,其中p,q,r,s,t∈[0,1],T₁、T₂为任意三角模,S₁、S₂为任意三角余模,给出了I为QL-、D-蕴涵时满足分配性方程的充要条件。     

康复机器人辅助步行训练对不完全性脊髓损伤患者步行能力的影响

为探讨康复机器人辅助步行训练（Robot-assisted gait training,RAGT）对不完全性脊髓损伤（Incomplete spinal cord injury,ISCI）患者步行能力的影响,将16例ISCI患者随机分配至对照组（常规康复治疗+地面步行训练）及试验组（常规康复治疗+RAGT）.治疗前及治疗4周、8周、12周后,分别进行下肢运动功能评分（Low extremity motor score,LEMS）及脊髓损伤步行指数II（Walking index for spinal cord injury II,WISCI II）评定.治疗后,两组患者LEMS均有提高（P < 0.05）,但试验组LEMS与对照组比较差异无统计学意义（P>0.05）.对照组治疗后各时间点WISCI II均较治疗前改善（P < 0.05）,试验组在治疗8周及12周后WISCI II较治疗前改善（P < 0.05）,但试验组WISCI II在训练12周后较对照组有明显提高（P < 0.05）.RAGT与地面步行训练在提高肌力上比较无明显差异,但在改善步行能力上RAGT优于地面步行训练.     

基于无人机高光谱数据的玉米叶面积指数估算

无人机高光谱遥感是低成本、高精度获取精细尺度农作物生物物理参数和生物化学参数的新型手段，以此快速反演叶面积指数（Leaf Area Index, LAI）对作物长势评价、产量预测具有重要意义。以山东禹城市玉米为研究对象，利用PROSAIL辐射传输模型模拟玉米冠层反射率获取LAI特征响应波段结合相关性定量分析获取对LAI变化最为敏感的波段，并以此计算6种植被指数（Vegetation Index,VI），利用6种回归模型分别对单一特征波段和VI进行反演建模，以实测LAI评定模型精度。研究表明，光谱反射率中516、636、702、760和867 nm等波段对LAI变化最为敏感，以此建立的单一特征波段反演模型预测LAI精度R2为0.44~0.58；RMSE为0.16~0.18，其中636 nm建立的模型(LAI=21.86exp(-29.47R₆₃₆))相比其他反演模型预测精度较高（R2=0.58，RMSE=0.16）；6种植被指数与LAI高度相关，相关性系数R ²为0.85~0.86，以此建立的反演模型相比单一特征波段反演模型精度有所提高，R2为0.66~0.72，RMSE为0.12~0.14；其中mNDVI构建的LAI估算模型（LAI=exp(2.76~1.77/mNDVI))精度最高（R2=0.72，RMSE=0.13）。无人机高光谱遥感是快速、无损监测农作物生长信息的有效手段，为指导精细化尺度作物管理提供依据。     

缺磷对不同磷效率基因型大豆光合日变化的影响

用1/2 Hoagland营养液培养磷高效大豆基因型BX10和磷低效基因型BD2，缺磷胁迫15d后测定其光合、光呼吸、暗呼吸的日变化。并进一步探讨了影响上述过程的原因。结果表明：缺磷使两基因型光合速率（Pn）显著下降，但BX10仍高于BD2（尤其在上午）；缺磷对PSⅡ光化学效率（Fv／Fm）和胞间CO2浓度（Ci）的影响无规律可循，与Pn的相关性也不显著；缺磷显著降低大豆气孔导度（Gs）．并与Pn呈极显著正相关（r=0．753。P〈0．001）。暗呼吸（Rd）与Pn日变化趋势相近（r=0．706，P〈0．01），但缺磷对其影响不大；缺磷下光呼吸（Pr）显著下降，而Pr／（Pn＋Pr）在BX10中却相对提高。光呼吸相对加强可能有助于磷高效基因型同补叶绿体光合作用所需的无机磷（Pi）。     

基于希氏变换的超声基频算法估计骨小梁间距

超声背散射信号对松质骨的微观结构极其敏感。骨小梁间距（Trabecular bone spacing,TbSp）是用于表征松质骨微结构的一个重要参数。为了能从松质骨超声背散射信号中准确获得松质骨TbSp,本文提出了一种希尔伯特变换和基频估计法相结合的TbSp估计算法。将该算法应用于离体松质骨的超声背散射信号,获得相应的TbSp值,并与显微CT测得的TbSp进行比较。结果表明,HFE算法在信号频率较高时（5 MHz和10 MHz）,估计结果更准确（误差<3%）且稳定（标准偏差<4%）;TbSp较大时,估计结果更为准确;TbSp的估计值与标准值在不同频率下均有显著的相关性（r2=0.75~0.99, p<0.01, n=16）。HFE算法估计TbSp具有准确性和稳定性,可用来表征松质骨TbSp。     

基于无人机高光谱数据的玉米叶面积指数估算

无人机高光谱遥感是低成本、高精度获取精细尺度农作物生物物理参数和生物化学参数的新型手段,以此快速反演叶面积指数（Leaf Area Index, LAI）对作物长势评价、产量预测具有重要意义。以山东禹城市玉米为研究对象,利用PROSAIL辐射传输模型模拟玉米冠层反射率获取LAI特征响应波段结合相关性定量分析获取对LAI变化最为敏感的波段,并以此计算6种植被指数（Vegetation Index,VI）,利用6种回归模型分别对单一特征波段和VI进行反演建模,以实测LAI评定模型精度。研究表明,光谱反射率中516、636、702、760和867 nm等波段对LAI变化最为敏感,以此建立的单一特征波段反演模型预测LAI精度R2为0.44~0.58;RMSE为0.16~0.18,其中636 nm建立的模型(LAI=21.86exp(-29.47R₆₃₆))相比其他反演模型预测精度较高（R2=0.58,RMSE=0.16）;6种植被指数与LAI高度相关,相关性系数R ²为0.85~0.86,以此建立的反演模型相比单一特征波段反演模型精度有所提高,R2为0.66~0.72,RMSE为0.12~0.14;其中mNDVI构建的LAI估算模型（LAI=exp(2.76~1.77/mNDVI))精度最高（R2=0.72,RMSE=0.13）。无人机高光谱遥感是快速、无损监测农作物生长信息的有效手段,为指导精细化尺度作物管理提供依据。     

压电式变截面悬臂梁低频振动能量收集器的设计与优化

为了降低环境振动压电能量收集器（PVEH）的固有频率（ωn），提高PVEH的输出性能，笔者提出了一种压电式变截面悬臂梁低频振动能量收集器（VCL—PVEH）。基于压电方程建立了不同压电材料分布的VCL—PVEH数值模型，优化了压电材料分布位置。研制了PVCL—PVEH原理样机，搭建样机实验平台。结果表明：当压电材料靠近悬臂梁固支端时，器件输出电压（V）和功率（P）最大；随着压电材料与固支端距离（D）增大，器件ωn降低。在相同压电材料面积下，三角形VCL—PVEH的ωn 最低（ωn = 25.7 Hz）、V最大（V = 100 V）。实验和计算表明，随负载阻抗（R）增大，P先增大后减小，存在最优R为25000 Ω，此时，P为240 mW，可直接点亮21只商用LED，满足低功耗农业物联网传感器供电的要求。     

基于同步性静息态脑网络的原发性失眠诊断

全球有约1/3的人口曾受到失眠的困扰，研究表明脑电的高度觉醒是失眠的一个重要原因，表现在高频脑电活动的增强。然而，由于存在较大的干扰因素，日常静息态条件下评判困难。因此本文提取原发性失眠患者和健康对照的脑电图（Electroencephalogram，EEG）高频频带（Beta、Gamma频带），使用更适合EEG这种非线性、非平稳信号的相位锁相值（Phase locking value， PLV）方法来构建静息态功能脑网络，使用自适应阈值技术进行二值化处理。为了提升失眠症脑网络特征评价的可靠性，综合了各脑网络特征，提出了用于失眠症检测的脑网络综合度量指标。且发现在Gamma频带上，综合指标在原发性失眠患者组与健康对照组之间存在显著性差异（p=0.044）。应用支持向量机（Support vector machine， SVM）进行自动分类，在Beta频带上的正确率达77.7%，灵敏度达90.7%，相较于原始网络特征正确率提高了9.4%，灵敏度提高了20.7%；同时与现有研究对比，本文提出的脑网络综合度量指标的正确率提升了19.4%，灵敏度提升了20.7%。此外，发现Beta频带的综合度量指标分类效果更好，对于失眠症患者的日常诊断具有潜在的应用价值。     

一类可分离SAT问题的O(1.890n)精确算法

布尔可满足性问题（SAT）是指对于给定的布尔公式,是否存在一个可满足的真值指派.这是第1个被证明的NP完全问题,一般认为不存在多项式时间算法,除非P=NP.学者们大都研究了子句长度不超过k的SAT问题（k-SAT）,从全局搜索到局部搜索,给出了大量的相对有效算法,包括随机算法和确定算法.目前,最好算法的时间复杂度不超过O（（2-2/k）ⁿ）,当k=3时,最好算法时间复杂度为O（1.308ⁿ）.而对于更一般的与子句长度k无关的SAT问题,很少有文献涉及.引入了一类可分离SAT问题,即3-正则可分离可满足性问题（3-RSSAT）,证明了3-RSSAT是NP完全问题,给出了一般SAT问题3-正则可分离性的O（1.890ⁿ）判定算法.然后,利用矩阵相乘算法的研究成果,给出了3-RSSAT问题的O（1.890ⁿ）精确算法,该算法与子句长度无关.     

多层语义融合CNN的步态人体语义分割

目的 针对反恐、安防领域利用监控视频进行步态识别时由光照、拍摄角度、遮挡等多协变量引起的轮廓缺失、人体阴影和运算时间等问题，提出了一种基于RPGNet（Regin of Interest+Parts of Body Semantics+GaitNet）网络的步态人体语义分割方法。方法 该方法按照功能划分为R（region of interest）模块、P（parts of body semantics）模块和GNet（GaitNet）模块。R模块提取人体步态感兴趣区域，起到提升算法效率和图像去噪的作用。P模块借助LabelMe开源图像注释工具进行步态人体部位语义标注。GNet模块进行步态人体部位语义训练与分割。借鉴ResNet和RefineNet网络模型，设计了一种细节性步态语义分割网络模型。结果 对步态数据库1 380张图片进行了测试，RPGNet方法与6种人体轮廓分割方法进行了对比实验，实验结果表明RPGNet方法对细节和全局信息处理得都很精确，在0°、45°和90°视角都表现出较高的分割正确率。在多人、戴帽和遮挡条件下，实验结果表明RPGNet方法人体分割效果良好，能够满足步态识别过程中的实时性要求。结论 实验结果表明，RPGNet步态人体语义分割方法在多协变量情况下能够有效进行步态人体语义分割，同时也有效提高了步态识别的识别率。     

Calculation of times to exhaustion at 100 and 120% maximal aerobic speed

The aim was to compare physiologic responses during exhaustive runs performed on a treadmill at 100 and 120% maximal aerobic speed (MAS: the minimum speed that elicits VO2max). Fourteen subelite male runners (mean +/- SD; age = 27+/-5 years; VO2max = 68.9+/-4.6 ml/kg(-1)/min(-1); MAS = 21.5+/-1 km/h(-1)) participated. Mean time to exhaustion tlim100% at 100% MAS (269+/- 77s) was similar to those reported in other studies. However, there was large variability in individual tlim100% MAS (CV = 29%). MAS was positively correlated with VO2max (r = 0.66, p<0.05) but not with tlim100%) MAS (r = -0.50, p<0.05). tlim100% MAS was correlated with t(lim) at 120% MAS (r = 0.52, p < 0.05) and to blood pH following the rest at 120% MAS (r = -0.68, p<0.05). The data suggest that running time to exhaustion at MAS in subelite male runners is related to time limit at 120% (tlim120%) MAS. Moreover, anaerobic capacity determined by the exercise to exhaustion at 120% MAS can be defined as the variable 'a' in the model of Monod and Scherrer (1954).     

A validation study of the Keyboard Personal Computer Style instrument (K-PeCS) for use with children

This study examines a potential instrument for measurement of typing postures of children. This paper describes inter-rater, test-retest reliability and concurrent validity of the Keyboard Personal Computer Style instrument (K-PeCS), an observational measurement of postures and movements during keyboarding, for use with children. Two trained raters independently rated videos of 24 children (aged 7-10 years). Six children returned one week later for identifying test-retest reliability. Concurrent validity was assessed by comparing ratings obtained using the K-PECS to scores from a 3D motion analysis system. Inter-rater reliability was moderate to high for 12 out of 16 items (Kappa: 0.46 to 1.00; correlation coefficients: 0.77-0.95) and test-retest reliability varied across items (Kappa: 0.25 to 0.67; correlation coefficients: r = 0.20 to r = 0.95). Concurrent validity compared favourably across arm pathlength, wrist extension and ulnar deviation. In light of the limitations of other tools the K-PeCS offers a fairly affordable, reliable and valid instrument to address the gap for measurement of typing styles of children, despite the shortcomings of some items. However further research is required to refine the instrument for use in evaluating typing among children.     

基于可靠性分析的MAS构建优化算法

采用多Agent技术进行制造系统建模时,Agent间可靠有效的交互协作是系统成功处理离散制造任务的重要保障。以增强多Agent系统的可靠性为目的,提出了使用并联式结构来构建多Agent系统的思想。在此基础上,给出了并联式Agent系统的可靠性评价方法,建立约束条件下的多Agent系统可靠性极大化问题的数学模型,利用填充函数算法的思想构造该模型的求解算法,并通过实例说明并联式结构和求解算法的有效性。     

Validation of an instrument for patient handling assessment

Nursing personnel are at high risk from work-related musculoskeletal disorders, especially back symptoms. Handling patients has been established as one of the factors playing an important role in the etiology of occupational low back pain. The aim of this study was to develop an instrument for patient handling assessment and to determine its validity and reliability. Instrument validity was established based on content and construct validity. Reliability was estimated through homogeneity, stability (test-retest) and equivalence (interrater) tests. Reliability estimated by internal consistency reached a Cronbach's Alpha coefficient of 0.81. Pearson's correlation coefficient for test-retest reliability was r = 0.92. There was an excellent agreement between observers, according to the k values (Kappa = 0.92). Interobserver (interrater) reliability was assessed by Pearson's correlation coefficient, reaching an r value of 0.84. The agreement between both observers was also fairly good (Kappa = 0.84). The results of the current study show that the instrument seems to be reliable and valid for patient handling assessment.     

Reliability-based structural design optimization: hybridized conjugate mean value approach

The efficiency and robustness of reliability techniques are important in reliability-based design optimization (RBDO). Commonly, advanced mean value (AMV) is utilized in reliability loop of RBDO but unstable solutions using AMV may be obtained for highly concave performance functions. Owing to the challenges of commonly reliability methods, the conjugate gradient analysis (CGA) is proposed as a robust methodology but it shows inefficient results for convex constraints. In this research, hybrid conjugate mean value (HCMV) method is proposed using sufficient condition for the enhancement of efficiency and robustness of RBDO. The CGA and AMV are dynamically utilized for simple solution of convex/concave constraints using sufficient descent criterion in HCMV. The HCMV is used to evaluate the convergence performances and is compared with numerous existing reliability methods through three reliability problems (two concave/convex mathematical examples and one applicable structure) and four RBDO problems. From the numerical results, the HCMV exhibited the better efficiency, and robustness compared to other studied formulations in reliability and RBDO problems.

     

Validity and reliability of the Spineangel® lumbo-pelvic postural monitor

Objective: to determine the reliability and the concurrent validity of the Spineangel^® lumbo-pelvic postural monitoring device. Methods: the dynamic lumbo-pelvic posture of 25 participants was simultaneously monitored by the Spineangel^® and Fastrak^TM devices. Participants performed six different functional tasks in random order. Within-task, within-session and between-day intraclass correlation coefficients (ICC(3,1), ICC(3,5), ICC(2,5), respectively) reliability were calculated for Spineangel^® measurements. Concurrent validity of the Spineangel^® was assessed by means of a Bland and Altman plot and by means of Pearson's correlation coefficient and paired t-test. Results: within-task, within-session and between-day ICC for the Spineangel^® were found to be excellent (>0.93). The Spineangel^® and Fastrak^TM pelvic measurements were found to have a good correlation (R = 0.77). Conclusion: the Spineangel^® is a reliable and valid device for monitoring general lumbo-pelvic movements when clipped on the belt or waistband of workers' clothing during various occupational activities.

Practitioner summary: The Spineangel^® can be used for assessing lumbo-pelvic posture during work or daily-life activities. This device was found to provide reliable and valid measurements for lumbo-pelvic movements. Further research is required to determine whether the use of this device is clinically relevant for patients presenting with low back pain.     

Validity and reliability of a novel device for bilateral upper extremity functional measurements

Background and objective

This study was designed to establish the validity and reliability of a new device that measures bilateral shoulder and elbow range of motion (ROM) and grip force performance in vivo. A further aim was to investigate the control of inter-limb grip force coordination during isometric force-maintenance tasks. Validity of the ROM and grip force measurements was examined using a validated clinical goniometer and standard weights.

Subjects

Twenty-one healthy adults (six female, 15 male; mean ± standard deviation age = 23.05 ± 3.51) were recruited for this study.

Design

All subjects were asked to perform tests to evaluate the validity and reliability of ROM, grip force maximum voluntary contraction (MVC) and coordination control measurements.

Results

The ROM and grip force measurements were linearly correlated with criterion standards. For reliability testing, all of the intraclass correlation coefficient values were >0.99. The inter-limb grip force coordination control task showed that the force modulation timing during dominant-to-non-dominant hand transition was longer than the non-dominant-to-dominant hand transition (p < 0.05).

Conclusions

These results demonstrate that this device is valid and reliable when used to measure shoulder and elbow ROM and grip force of both hands. Isometric force-maintenance tasks also indicated changes in inter-limb grip force control.     

Changes in plasma lipids and lipoproteins following 10-days of prolonged walking: influence of age and relationship to physical activity level

The aim of the present study was to examine (1) the influence of 10 days of prolonged walking on plasma total-cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) concentrations, (2) the effect of age on any changes in plasma cholesterol and lipoprotein concentration, and (3) whether any changes in cholesterol and lipoprotein concentrations are correlated to the participants' physical activity level (PAL). Seventeen male participants were divided into two groups according to their age. The nine participants in group 1 constituted the younger group (age 24 +/- 3 (SD) years), whereas eight older participants were in group 2 (age 56 +/- 3 years). Both groups completed 10 consecutive days of high-intensity hill walking. Mean (range) daily distances and ascent were 21 km (10-35 km) and 1,160 m (800-2,540 m), respectively. Identical distances and ascents were covered by each group. For each participant, PAL was calculated from energy expenditure, assessed by the doubly-labeled water technique, divided by the individual's basal metabolic rate. Venous blood was sampled immediately prior to, and following, the 10 consecutive days of walking. Following these 10 days, the older group showed a greater decrease in both TC (-25 +/- 11% vs. -10 +/- 11%; P < 0.05) and LDL-C (-26 +/- 12% vs. -4 +/- 13%; P < 0.05) when compared with the young. Likewise, the older group showed a greater increase in HDL-C (38 +/- 15%; P < 0.05), after the 10 days, whereas no significant change was evident in the younger group. In the older participants, there were strong positive relationships between PAL and the decreases in TC (r = 0.79, P < 0.05) and LDL-C (r = 0.74, P < 0.05). Conversely, in the younger group there were strong negative relationships between PAL and the decreases in TC (r = -0.74, P < 0.05) and LDL-C (r = -0.86, P < 0.01). These correlations persisted when changes in lipid concentrations were corrected for changes in plasma volume. These data suggest an 'age-dependant' threshold for PAL, rather than a specific exercise intensity or duration, may be critical for inducing favourable changes in HDL-C, LDL-C and TC.     

The between-day and inter-rater reliability of a novel wireless system to analyse lumbar spine posture

Lumbar posture is commonly assessed in non-specific chronic low back pain (NSCLBP), although quantitative measures have mostly been limited to laboratory environments. The BodyGuard? is a spinal position monitoring device that can monitor posture in real time, both inside and outside the laboratory. The reliability of this wireless device was examined in 18 healthy participants during usual sitting and forward bending, two tasks that are commonly provocative in NSCLBP. Reliability was determined using intraclass correlation coefficients (ICC), the standard error of measurement (SEM), the mean difference and the minimal detectable change (MDC90). Between-day ICC values ranged from 0.84 to 0.87, with small SEM (5%), mean difference (<9%) and MDC90 (<14%) values. Inter-rater ICC values ranged from 0.91 to 0.94, with small SEM (4%), mean difference (6%) and MDC90 (9%) values. Between-day and inter-rater reliability are essential requirements for clinical utility and were excellent in this study. Further studies into the validity of this device and its application in clinical trials in occupational settings are required. STATEMENT OF RELEVANCE: A novel device that can analyse spinal posture exposure in occupational settings in a minimally invasive manner has been developed. This study established that the device has excellent between-day and inter-rater reliability in healthy pain-free subjects. Further studies in people with low back pain are planned.     

Measurement of trunk bending during work by direct observation and continuous measurement

An observational method and a continuous measurement technique were simultaneously applied to record bending of the trunk during work. In a group of 16 workers performing dynamic tasks a significant correlation (r = 0.57) was found between the two methods. A similar result was observed among 14 sedentary workers (r = 0.62). Although significant correlations between direct observation and continuous recording techniques were present, large differences were found between data obtained from individual subjects. The results cast doubt on the validity of assessments of percentage of worktime with bent trunk at an absolute level using only one measurement method. It is suggested that greater consideration has to be given in future studies to the reliability of measurement of postural load due to trunk bending.