对PDM系统实施方法的思考

PDM系统的实施是1个艰巨而复杂的过程。基于中航工业沈阳发动机设计研究所PDM系统项目的实践应用,总结了其成功实施方法和规避实施风险的一些经验。     

A model for discrimination and prediction of mental workload of aircraft cockpit display interface

With respect to the ergonomic evaluation and optimization in the mental task design of the aircraft cockpit display interface, the experimental measurement and theoretical modeling of mental workload were carried out under flight simulation task conditions using the performance evaluation, subjective evaluation and physiological measurement methods. The experimental results show that with an increased mental workload, the detection accuracy of flight operation significantly reduced and the reaction time was significantly prolonged; the standard deviation of R-R intervals（SDNN） significantly decreased, while the mean heart rate exhibited little change; the score of NASA_TLX scale significantly increased. On this basis, the indexes sensitive to mental workload were screened, and an integrated model for the discrimination and prediction of mental workload of aircraft cockpit display interface was established based on the Bayesian Fisher discrimination and classification method. The original validation and cross-validation methods were employed to test the accuracy of the results of discrimination and prediction of the integrated model, and the average prediction accuracies determined by these two methods are both higher than 85%. Meanwhile, the integrated model shows a higher accuracy in discrimination and prediction of mental workload compared with single indexes. The model proposed in this paper exhibits a satisfactory coincidence with the measured data and could accurately reflect the variation characteristics of the mental workload of aircraft cockpit display interface, thus providing a basis for the ergonomic evaluation and optimization design of the aircraft cockpit display interface in the future.     

基于边缘相似性的异源图像匹配

异源图像匹配是视觉导航、多源图像融合分析的关键步骤之一。对于成像机理差别较大的异源图像,如SAR图像和可见光图像,采用传统的异源图像匹配算法难以得到满意结果。本文提出一种基于边缘相似性的异源图像匹配方法,首先分别提取待匹配图像的边缘特征点集;然后计算基准图的边缘距离场;最后基于边缘相似性模型,通过实时图边缘图和基准图边缘距离场计算边缘相似度,寻找相似度最大的变换参数即为最终匹配参数。采用SAR与可见光图对方法进行了测试,结果表明,这种方法能够快速可靠地实现异源图像匹配。     

The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.     

An experimental analysis of situation awareness for cockpit display interface evaluation based on flight simulation

Aircraft cockpit display interface (CDI) is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness (SA) is frequently considered to improve the design, as the CDI must provide enough SA for the pilot to maintain the flight safety. In order to study the SA in the pilot-aircraft system, a cockpit flight simulation environment is built up, which includes a virtual instrument panel, a flight visual display and the corresponding control system. Based on the simulation environment, a human-in-the-loop experiment is designed to measure the SA by the situation awareness global assessment technique (SAGAT). Through the experiment, the SA degrees and heart rate (HR) data of the subjects are obtained, and the SA levels under different CDI designs are analyzed. The results show that analyzing the SA can serve as an objective way to evaluate the design of CDI, which could be proved from the consistent HR data. With this method, evaluations of the CDI design are performed in the experimental flight simulation environment, and optimizations could be guided through the analysis.     

Mutagenic effects of heavy ion radiation in plants.

Genetic and developmental effects of heavy ions in maize and rice were investigated. Heavy particles with various charges and energies were accelerated at the BEVALAC. The frequency of occurrence of white-yellow stripes on leaves of plants developed from irradiated maize seeds increased linearly with dose, and high-LET heavy charged particles, e.g., neon, argon, and iron, were 2-12 times as effective as gamma rays in inducing this type of mutation. The effectiveness of high-LET heavy ion in (1) inhibiting rice seedling growth, (2) reducing plant fertility, (3) inducing chromosome aberration and micronuclei in root tip cells and pollen mother cells of the first generation plants developed from exposed seeds, and (4) inducing mutation in the second generation, were greater than that of low-LET gamma rays. All effects observed were dose-dependent; however, there appeared to be an optimal range of doses for inducing certain types of mutation, for example, for argon ions (400 MeV/u) at 90-100 Gy, several valuable mutant lines with favorable characters, such as semidwarf, early maturity and high yield ability, were obtained. Experimental results suggest that the potential application of heavy ions in crop improvement is promising. RFLP analysis of two semidwarf mutants induced by argon particles revealed that large DNA alterations might be involved in these mutants.     

飞机界面设计颜色匹配性

针对飞机显示界面设计中存在的问题,开发了一个用于工效学实验的飞行信息显示界面仿真模型.以该模型为背景开展实验,综合使用主观和客观测量方法对不同颜色匹配特性进行了研究.以反应时间作为绩效评价指标,并利用模糊数学的方法对主观数据进行处理.实验得到以下主要结果:确定了不同背景色和目标色匹配的辨识快慢顺序和喜好程度;不同颜色匹配的作业绩效和喜好程度不全相一致;白色/红色、棕色/黄色、暗灰/蓝色、黑色/淡绿、白色/蓝色较适宜作为背景/目标色组合,白色/黄色、黑色/蓝色则不适宜.     

PTC的现在进行时——PTC 2009中国区用户大会见闻

作为一个进入中国市场十几年的CAE公司,LMS对于大多数从事制造领域的信息化工作者来说,并不陌生. 去年是LMS国际公司成立30周年,在过去的30年间,LMS从比利时鲁文大学的一个测试系统公司,逐步发展成为世界工程测试与虚拟仿真领域的领头羊.     

2009亚洲航展蓄势待发——访励展博览集团华东区副总裁李雅仪女士

[编者按]亚洲国际航空展览会暨论坛将于今年9月在香港举行,本届展会将延续以往的B2B模式,致力于为航空公司,飞机、发动机制造商及航空电子、机舱维修和物流等业内专业人员提供交流的平台.究竟本届亚洲航展的规模如何?有哪些值得我们关注的亮点?带着这些问题,本刊记者采访了主办单位励展博览集团华东区副总裁李雅仪女士.     

脉冲爆震推进技术研究进展

叙述了脉冲爆震发动机的工作原理和特点、研究现状和应用前景、关键技术和立项建议。