Fundamentals of systems ergonomics/human factors

Ergonomics/human factors is, above anything else, a systems discipline and profession, applying a systems philosophy and systems approaches. Many things are labelled as system in today's world, and this paper specifies just what attributes and notions define ergonomics/human factors in systems terms. These are obviously a systems focus, but also concern for context, acknowledgement of interactions and complexity, a holistic approach, recognition of emergence and embedding of the professional effort involved within organization system. These six notions are illustrated with examples from a large body of work on rail human factors.     

尿素DCS系统优化与完善

通过对尿素DCS系统几个控制回路的改造，达到了优化工艺指标、完善工艺条件、节能降耗的目的，保证了尿素系统的安全、稳定、长周期运行。     

Effects of personal,psychosocial and occupational factors on low back pain severity in workers

Low back pain (LBP) remains the most common work-related musculoskeletal disorder (WMSD). While most of the LBP research has focused on occupational risk factors, other underlying causal mechanisms may exist since not all workers performing the same task develop an injury. Previous research has identified three primary risk factor categories for LBP (occupational, personal and psychosocial factors); however, few studies have investigated the impact of cross categorical risk factor interactions on LBP. The objective of this study was to investigate the effects of occupational, personal and psychosocial factors, and their interactions, on LBP severity in a population of workers currently suffering from LBP. Sixty LBP patients recruited for the study through local physicians and local announcements, completed questionnaires relating to identified occupational, personal and psychosocial risk factors, and completed an Oswestry Disability Index (ODI). Multiple regression models for predicting LBP severity were developed for each risk factor category and for a combined risk factor model (which included factors from all three risk factor categories) that included two-way interactions. Results showed that the final model consisted of both main effects and interaction terms between risk factor categories and had an adjusted R² value of 0.85, a significant improvement over models developed for the individual categories. These findings illustrate the need to consider all three broad categories of risk factors simultaneously in predicting injury status and in developing effective potential intervention efforts.     

基于Monte Carlo随机模拟的综合交通网络布局评价与决策方法

针对综合交通网络评价指标权重及属性值具有主观性和随机性的特点,提出了基于模拟运算的布局规划方案排序选优的群体随机决策方法.仿真生成满足集结的多个专家对指标重要性偏好排序统计分布的权重,同时考虑交通需求的不确定性对指标值的影响,结合客观熵权计算方案的综合评价值,由多次模拟得到的排序优势度确定方案的优劣差异.根据设计的仿真流程通过算例说明了方法应用的有效性,评价中考虑了主客观因素及随机性特征,可以为网络布局提供科学决策依据.     

工艺因素影响焦炭颗粒耐压强度的试验研究

焦炭颗粒的耐压强度一直是焦炭颗粒最重要的性质之一。利用最近提出的表征焦炭颗粒耐压强度的新方法，就模压压力、加压方式、粒度组成范围、粒度大小、粒度配比等因素对单粒度或多粒度组成焦炭颗粒耐压 强度的影响进行了较为详细的试验研究。结果表明：（1）焦炭颗粒的粒度大小和粒度范围均可用其原始平均细度来表征。焦炭颗粒的原始平均细度越大，其耐压强度系数也就越高；（2）多粒度组成焦炭颗粒混合料的耐压能力比单粒度组成混合料的耐压能力要高得多。对多粒度组成焦炭颗粒而言，模压压力及粒度组成配比对其耐压强度系数的影响不甚明显；（3）分阶段缓慢加压到位比一次快速加压到位有利于提高焦炭颗粒的耐压强度系数。     

尿素设备腐蚀的影响因素及防腐措施

从温度、氨碳比、水碳比、甲铵液浓度、氧含量、硫含量、氯离子含量、介质流速等方面论述了尿素设备腐蚀的影响因素;提出了在正常生产和停车封塔情况下的防腐控制措施。     

基于MPLS的VPN互访技术

针对VPN互访问题,根据IPSec-VPN互访方法的不足,提出动态MPLS-VPN方法.利用随机分配的标签,在需要互访的不同VPN网络节点之间构建MPLS通道,利用互访规则集检验节点的连接申请,根据过滤规则控制数据包的传输,通过设定传输时长限制节点互访的时间,实现VPN之间接节点、按方向、按时间的细粒度互访控制,确保数据传输的安全性和高效性.给出动态MPLS-VPN方法实现互访的步骤,对方法进行分析比较.     

原位合成莫来石晶须及其微观结构的研究

本文通过以高岭土、工业氢氧化铝为原料,添加适量AlF3和V2O5,在高温下原位合成了莫来石晶须,采用扫描电镜（SEM）研究了合成的莫来石晶须的微观形貌,探讨了莫来石晶须的生长机理,并讨论了影响莫来石晶须生长的相关因素.在综合考虑影响莫来石晶须生长的相关因素后,制备出晶须多、长径比大、分布均匀的莫来石晶须样品.     

基于iFIX平台的模糊PID控制在锅炉主汽压力控制中的设计

针对三台煤粉锅炉控制效果差,自动投入率低,尤其是主汽压力(流量)波动较大,不仅经济效益低,而且对下游设备造成严重损害。对三台锅炉进行了技术改造,通过引入基于参数自适应Fuzzy-PID的控制算法,在基于VBA脚本的iFIX上实现这一算法,对锅炉控制进行优化指导,使锅炉自动投入率提高,主汽压力(流量)趋于稳定,锅炉处于较高效率下运行,提高了经济效益。     

A model of ammonia volatilisation from a dairy farm: an examination of abatement strategies

A model (MAST) to calculate the mass flow of NH₃ through amodel dairy farm has been developed. Updated emission factors for UKagriculturewere used to examine different abatement strategies available for a typicaldairy farm. A range of annual NH₃ emissions was calculated for bothslurry and FYM based dairy systems. Emission for the slurry based system ranged between 27 kg NH₃-N ha^–1 yr^–1, achieved using a combination of abatementstrategies, and 107 kg NH₃-N ha^–1 yr^–1, calculated for a worst casescenario. For FYM, this range was between 33 and 86 kg NH₃-Nha^–1 yr^–1. The greatest reductionswereachieved by manipulating options linked to fertiliser usage and manureapplication.