基于加速度计的无陀螺捷联惯性制导系统设计

针对舰炮武器系统射击精度低的问题,研究了适宜在炮弹中应用的基于微加速度计的无陀螺捷联惯性制导系统.采用三种方法对载体的角速度进行解算并分析了各种方法的利弊,提供了载体运动参数解算模型,通过仿真计算验证无陀螺方案的可行性,为惯性制导炮弹的发展提供了参考.     

基于不确定推理的校园交通环境评价方法研究

校园是广大师生生活学习的场所.一个美好的校园环境会给人带来很多积极的影响.校园交通环境是校园环境的一个重要组成部分,校园交通环境的好坏对广大师生的出行以及身心健康都有很大的影响.有人曾用模糊模式识别方法、统筹学评价法、决定评价法等方法对校园交通环境进行评价.相较于上述几种方法,D-S证据理论能考虑校园交通环境使用者的感受,使得到的结果更加客观.本文以东北林业大学为例,运用D-S证据理论对东北林业大校园交通环境进行评价.     

Influence of GABAergic pathway on retinal adaptation-related response changes

Retinal ganglion cells （RGCs） exhibit adaptive changes in response to sustained light stimulation, which include decrease in firing rate, tendency to shrink in receptive field （RF） size and reduction in synchronized activities. Gamma-aminobutyric acid-ergic （GABAergic） pathway is an important inhibitory pathway in retina. In the present study, the effects of GABAergic pathway on the contrast adaptation process of bullfrog RGCs were studied using multi-electrode recording technique. It was found that the application of bicuculline （BIC）, a gamma-aminobutyric acid A （GABAA） receptor antagonist, caused a number of changes in the RGCs＇ response characteristics, including attenuation in adaptation-dependent firing rate decrease and the adaptation-dependent weakening in synchronized activities between adjacent neuron-pairs, whereas intensified the adaptation-dependent RF size shrinkage. These results suggest that GABAA receptors are involved in the modulation of the firing activity and synchronized activities in contrast adaptation process of the RGCs, whereas the adaptation-related RF property changes involve more complicated mechanisms.     

Opportunistic Replacement Optimization for Multi-Component System Based on Programming Theory

It is widely accepted that too excessive or too insufficient maintenance actions on a system are consumptive or potentially risky. This paper focuses on the optimization of opportunistic replacement for a multicomponent system in which no failure or suspension histories can be used for prediction of all the critical components in the system. Firstly, the remaining useful life (RUL) is predicted using the real-time sensor data, which is based on an “individual-based lifetime inference” method. Then a failure risk estimation method is introduced, which is based on the degradation extent and service time of components. Subsequently, the possible replacement combinations of components are compared, which is based on a proposed current-term cost rate. Finally, the best replacement scheduling is selected. The proposed framework is validated by the simulation dataset and PHM-2012 competition bearing dataset. Group replacement and individual replacement are conducted for comparison, and sensitivity analysis is discussed.