Ranking of aircraft maintenance organization based on human factor performance

Aircraft maintenance organisation is a complex socio-technical setup, where human factors influence the quality of aircraft maintenance service. Maintenance service quality is assessed based on the commitment of management and its ability to provide suitable facility, tools, spares and manpower supported with comfortable environment and maintenance procedures. Assessment of the service quality of the aircraft maintenance organisation is a complex process. Airlines, regulators, insurance companies and other agencies need decision support system, to assess the performance of a maintenance organisation. This paper provides criteria and scientific approach for assessing the maintenance organisation; it presents a methodology of applying Analytical Hierarchy Process to prioritise the key functions and to rank the maintenance organisations under study. The study has established that maintenance service quality in airline is directly correlated to its fleet size.     

气象传感器网络系统架构与体系结构研究

传感器网络将在气象观测领域发挥越来越重要的作用。针对地面气象观测的现实需求,提出了气象传感器网络的概念,构建了气象传感器网络的应用场景,完成了其需求分析与系统架构设计,深入分析了气象传感器网络可采用的通信手段。在陆上传感器网络体系结构的基础上,结合气象传感器网络的特点,设计了气象传感器网络的体系结构,将其结构划分为物理层、数据链路层和网络层。对该体系结构各层的功能进行了深入分析,最后对气象传感器网络的应用前景进行了展望。     

Interface trap effect on the transient characteristics of a photovoltaic InSb infrared detector

The transient characteristics can be significantly affected by the interface trap. In order to reveal the intrinsic mechanism and provide some references for the design of detectors, the interface trap effect on the transient characteristics of a back-illuminated photovoltaic InSb infrared detector is studied with two-dimensional simulations. The relationships between interface traps and some key physical parameters, such as the hole concentration, the recombination rate and the electric field, are analyzed to reveal the intrinsic mechanisms of the influence of the interface traps on the transient characteristics. Studies show that with the increase of the interface trap density, the recombination rate and the electric field near the interface increase, the hole concentration decreases, and the “black holes” in current density distribution appear and move forward to the pn junction. And the transient photoresponse decreases with the increase of the interface trap density.     

Acquisition of amino acids by Lactobacillus delbrueckii subsp. bulgaricus 2038 when grown in the presence of casein

The acquisition of amino acids by Lactobacillus delbrueckii subsp. bulgaricus 2038 (Lb. bulgaricus 2038) when grown in the presence of bovine casein, the major protein in bovine milk, was investigated by examining the expression of genes related to proteolysis and amino acid biosynthesis. To support the growth on bovine casein, Lb. bulgaricus 2038 has to synthesise five kinds of amino acids de novo, as proteolysis from casein does not provide these. The incomplete hydrolysis in combination with amino acids biosynthesis may explain the slow growth of Lb. bulgaricus 2038 in a casein environment. Meanwhile, it was determined that Lb. bulgaricus 2038 uses different intracellular peptidases when grown in casein or whey medium, and initially yields the important amino acid glutamate from the C-terminal or N-terminal end of peptides imported into the cell.     

江西省农村计划生育适宜技术服务对象满意度调查

目的了解江西省农村计划生育适宜技术服务对象对技术服务的满意度,分析满意度的影响因素。方法采用分层抽样方法,对412例接受计划生育适宜技术服务的服务对象进行满意度问卷调查。结果调查对象平均年龄为（29.71±6.17）岁;服务对象对计划生育适宜技术服务很满意、比较满意者分别占56.55%和33.25%;多因素Logistic回归分析提示影响计划生育适宜技术服务满意度的因素有：诊疗效果、诊疗时间和诊疗费用。结论服务对象对江西省农村计划生育适宜技术服务满意,综合满意率为89.81%。     

光电红外成像消旋系统测控技术研究

针对某光电红外成像消旋系统检测项目的需求,设计完成了一套基于PCI总线的自动化测控系统。该系统以旋转变压器和RDC组成轴角编码器,通过数据采集卡实时采集角度数据,再经实时滤波算法和信号变换,显示消旋角度。测控系统采用了积分分离的PID控制方法,驱动直流力矩电机完成消旋功能。该测试系统已成功应用于某光电红外成像消旋系统的维修与测试工作。试验结果表明,本系统设计合理,工作可靠,自动化程度高,具有较强的实用性,满足了自动化测控系统结构化、通用化、模块化的设计要求。     

随机性标量参数分布式量化的最优比特分配

本文研究了在总比特率设定的情况下,改良并给出表现更优的量化器,以及如何实现基于网络的随机标量参数分布式量化估计,重点讨论传感器比特数最优分配.与常规给定各传感器的量化比特率不同的是,本文将结合估计器算法使用和不同量化器的构建,来研究固定总比特率下的分配.文中的观测模型噪声服从高斯分布,并且以此模型为对象通过均匀量化探讨基于一般类型与线性估计器的最理想比特分配方式.前者均方误差上限与后者对应下限在高精度处理方案下结果几乎相同,都表现出网络中观测噪声误差反比于量化级数这一特性.此外还借用交替序列比特分配算法以确保求解出的数值解恒非负.最后从MATLAB仿真结果可以看到,本文给出的最优比特分配估计器较传统方案的表现更优.     

织物增强复合材料梁结构热校形工艺

本文借鉴金属零件热校形工艺的经验,利用复合材料在高温下的应力松弛现象,通过热校形工艺修正复合材料零件的形状。制造了碳纤维平纹织物/环氧复合材料L形梁、C形梁,通过自制的热校形模具,以实验方法研究热校形时间、热校形载荷对零件形状的影响,分析复合材料热校形工艺的可行性。研究表明,复合材料热校形工艺中零件变形的主要原因是零件在高温下发生应力松弛,其他因素可以忽略;热校形载荷、热校形时间都对热校形工艺的效果有重要影响。针对特定的复合材料结构,采用合理的热校形工艺过程能够有效地控制构件形状,方便零件的装配。     

Solving push-out conflicts in apron taxiways of airports by a network-based simulation

At busy airports, push-out conflicts occur simultaneously in apron taxiways and affect gate assignment operations in apron control. In current manual operations, it is not easy for apron controllers to consider and solve such conflicts in an exact and efficient manner, due to the uncertainties involved in the operations, the difficulties in efficiently controlling and solving push-out conflicts, and also the fact that too many more important factors should be considered in these real-time operations. At most airports today, a buffer time between the use of gates is introduced in gate assignment operations to reduce the impact of push-out conflicts to the delay of aircraft getting into, or leaving from, a gate. From the standpoint of gate assignment operations in apron control, this study analyzes aircraft ground movements and conflicts in apron taxiways. For coping with increasing air traffic demand and minimizing delays caused by inefficient scheduling of aircraft ground movements, and their effect on the gate assignment operations, a network-based model is proposed to perform simulation to support the analysis of the effect of aircraft ground movements in apron taxiways to gate assignment operations. By the proposed method, the delay characteristics of aircraft ground movements in apron taxiways and the activities on gates can be analyzed and studied in detail. Furthermore, the results of the simulation are applied to solve push-out conflicts and minimize delays to aircraft on gates in apron control. Computational results of experiments are also presented and discussed.