飞机舱音记录器背景声信息的联合时频分析

机舱音记录器记录的舱音主要是由话语音、噪声和具有不同物理意义的背景声组成的复杂混合体，用传统的辨听和分析方法难以获取更多的舱音特征参数。以舱音记录器记录的主告警声为例，针对传统短时傅立叶变换在舱音辨听、分析的不足，将联合时频分析引入到飞机舱音分析中，扩展了舱音分析方法。对比分析结果表明：时频分布及其重排在时频分辨率、时频凝聚性、抑制交叉项干扰上各有所长，适合分析非平稳舱音背景声，从而为飞行事故调查提供一种值得借鉴的方法。     

基于信息融合的飞机舱音声信号分析与故障诊断

飞机黑匣子中舱音记录器记录的舱音声信息是分析、诊断飞行事故原因的关键依据之一。以多个典型舱音样本为例,在阐述信息融合原理基础上,构建信息融合三个层次模型,建立典型舱音特征库。开展基于产生式规则的信息融合的飞机舱音声信号的分析与故障,依据舱音二进制诊断树,得到分析诊断结果,为准确掌握飞行事故原因、分析诊断飞行事故、保障航空飞行安全具有一定借鉴作用。     

飞机驾驶舱话音记录器中开关声的三尺度小波分析

国内目前主要采用基于计算机音频原理的译码系统对飞机驾驶舱话音记录器记录的舱音信号进行“辨听”分析,这种舱音分析方法存在不易获得准确的舱音信号特征的缺点。根据这一问题,针对某一真实舱音中的瞬态开关声信号,提出了利用一维离散小波函数进行三尺度分解小波方法,得到了基于传统“辨听”方法得不到的、更多、更准确的舱音声频特征,为识别分析瞬态、非平稳飞机舱音信号提供了一种较好的参考依据。     

一种舱音背景声的特征频率获取方法-CZT算法

针对传统舱音译码系统在辨听、分析舱音背景声上的不足,并利用线性调频Z变换(CZT)适用于高采样频率的信号、而且计算中可以任意调整频率的分辨率等频谱分析的灵活性,提出基于CZT获取飞机舱音背景声的特征频率的新方法.通过仿真和以飞机驾驶舱高速配平移动背景声为例进行计算分析.和实验测试结果对比得出:CZT方法是一种适合于确定舱音背景声特征频率的有效方法,对调查飞机事故原因具有较好的实用性.     

飞机舱音背景声下的鲁棒语音端点检测

有效提取飞机舱音背景声下的语音信息对飞机失事原因调查十分重要.提出了基于统计模型的语音端点检测方法.利用高斯混合模型逐帧计算语音/非语音状态的输出概率,利用后向估计方法和平行非线性卡尔曼滤波器估计非平稳噪声帧.最后,通过似然比门限值的计算区分语音和非语音段.与目前典型的语音端点检测算法的对比实验表明,在飞机舱音背景声下,该算法具有较好的准确性、自适应性和鲁棒性.     

基于不同方法的飞机舱音背景声频谱特征的获取与分析

由于飞机事故的舱音样本不宜对外公布、同一机型的异常舱音背景声也不易在飞行过程中测录到,且基于舱音译码辨听和音频分析的传统方法难以准确获得舱音背景声的频谱特征。因此,获取、检验和比较已获舱音背景声的频谱特征的正确性十分必要。为解决此问题,以测录到的飞机超速音频警告声为研究对象,首先基于小波变换的多尺度分析获取该舱音背景声的频谱特征,然后提出基于线性调频Z变换方法和相关分析方法对该警告声的主要频谱计算比较。结果及应用表明：小波变换、线性调频Z变换（CZT）和相关分析三种不同理论方法的尝试为调查分析飞机事故原因提供了可供比较的、有效的新途径。     

飞机舱音背景声下语音增强技术

有效提取飞机舱音背景声下的语音信息对飞行事故调查十分重要。提出一种适用于飞机座舱噪声环境下的语音增强方法。以卡方分布作为纯语音谱幅值的先验模型,采用最小均方误差短时谱估计法对带噪语音中的纯语音谱进行估计,误差估计方程中采用权值函数对估计值进行非线性加权。在仿真试验中利用语音质量的客观评价标准选取适合于舱音背景声下的纯语音谱估计参数,使增强语音中噪声抑制和语音失真之间达到平衡。最后将提出的语音增强方法与目前典型方法进行了对比实验,验证算法的有效性。     

典型舱音背景声在消声室中测试分析研究

基于全消声室良好的自由声场环境特性和声学测试原理，用LMSSC305对真实飞机和模拟机驾驶舱中的开关提示等4种典型舱音背景声在全消声室中进行测试分析应用研究。结果表明：基于全消声室测试的舱音特征谱值与理论计算结果一致，且比传统的人工译码辩听和音频分析的结果准确，验证舱音特征谱值计算结果的可靠性。     

民机驾驶舱舱音小波包分析及特征提取

摘 要：针对民航事故调查中的舱音背景声分析，利用小波包分析方法，对不同种类开关手柄声进行了三层分解，提取了不同开关手柄声的各频带归一化能量特征用于对开关手柄进行识别。最后，以B737客机的常用开关手柄的声音为研究对象，采集了大量舱音信号，利用该方法，对舱音信号进行了分析识别，并对结果进行统计验证。
     

飞行数据记录器译码技术研究

为获得"人—飞机—环境"的各自特性及其相关性信息,机载飞行参数记录系统可记录几十至几百个参数,这些参数在辅助地勤维护、飞行训练评估、分析事故原因和事故责任划分中发挥着十分重要的作用。本文概述了飞行参数记录器的记录方式,研究了记录器译码算法及软件设计思想,实现了将某型飞机记录器记录的数据从二进制数到实际工程值之间的转化。     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Investigation of the Corrosion Behaviors of HVOF-Sprayed Carbide Cernet Coatings in Molten Al-Zn-Si Alloy Bath

In continuous hot-dip galvanization process the corrosion and chemical stability of the sink roll in the galvanizing bath are important problem which effects on the quality and productivity. In order to protect the sink roll the carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3 C2-cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50 wt % aluminum at 833 K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in coating and corrosion behaviors of these coatings were investigated by XRD, SEM and EPMA etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were approached.     

Fundamental study of adhesion of ice to cooling solid surface (Discussion on influence of copper oxide layer on ice adhesion force)

In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.     

＂Three Transformations＂ and Standardization

During his inspection in Henan Province in May, Chinese President Xi Jinping stressed to ＂push forward the transformation from China Speed to China Quality, from Made in China to Created in China, and from Chinese Products to Chinese Brand＂. The ＂Three Transformations＂ are the specific requirements and goal of China＇s national development in the context that market should play a decisive role in the allocation of resources.     

重塑标准推行格局 推动LED照明的普及（英文）

正When you are enjoying the green,energy-saving and healthy lighting of IKEA LED luminaire,you may not realize that most of IKEA’s LED bulbs are produced by the LED luminaire smart manufacturing system of Hangzhou Zhongwei Photoelectricity CO.,LTD(ZVISION).No longer enclosed in the laboratory,the product standards are brought into the factory workshop and even to the entire production process.Thus,the standards are promoted and applied in a favorable way by enterprises,benefitting consumers with high quality products.