基于变权层次分析法的管制员应激管理研究

目的空中交通管制员由于工作压力大,精神高度紧张,在工作时极易产生过度应激。本文通过对应激源进行风险评估排序,为空管应激管理提供相应对策。方法首先通过层次分析法,构造判断矩阵,依照专家评分对各应激源进行权重的初步分析和排序;接着运用变权层次分析法,结合某管制单位实例进行验证分析,克服了层次分析法的固定权重导致非公正性评估的弊端,最终得出一个符合实际的总排序。结果本文最终得出的各应激源的权重排序符合实际,基于此提出的应激管理对策具有实用意义。结论以上研究提出的应激管理对策,能够为研究管制员的应激和规避应激引发的不安全事件提供科学依据和保障。     

空中交通管制员的心理能力研究及对策建议

空中交通管制员的心理素质对于提高空中管制质量,维护空中交通秩序,防止和避免空中交通事故具有重要作用。本文从管制人员的特殊工作任务人手,分析管制员的心理能力需求,研究影响管制员心理变化的因素,最后提出相关的对策建议,为提高空中交通管制人员心理能力提供相应参考。     

情绪在管制工作中影响的初步探讨

关于空中交通管制员工作情绪的探讨研究，对空中交通管制系统的改进、发展至关重要。本文分析了影响管制工作和管制员身心健康的情绪构成，阐述了不良情绪对管制工作及管制员身心健康带来的负面影响。笔者介绍了一些缓解不良情绪的方法。     

空中交通管制员工作负荷的模糊综合评价

空中交通管制员作为空中交通管制系统的主体,其行为状态容易受到环境、心理等复杂因素的影响,具有不确定性。文章提出了基于模糊综合评判的管制人员工作负荷评价模型。从人-机-环境三者关系,建立了影响个体管制员工作负荷的18项重要指标体系,依据专家群体决策确定其权重,根据待评定的工作负荷隶属度,确定个体管制员工作负荷等级。通过具体实例的应用,检验了该方法的可行性。     

基于人为因素的管制员情景意识研究

目的管制员的情景意识水平直接影响空中交通管制安全高效运行。为提高管制员情景意识,本文系统分析影响管制员情景意识的人为因素,并确定各因素影响程度大小。方法首先在现有文献的理论基础上,采用李克特量表设计问卷并构建了人为因素-情景意识结构分析模型,然后通过AMOS 21.0软件构建的结构方程模型(Structural Equation Modeling, SEM),检验假设关系模型,实现全面影响因素及作用机制。结果本文总结的应激调节能力、注意力、疲劳和睡眠情况等人为因素均对管制员的情景意识具有显著影响,且应激调节能力对情景意识的影响程度最大,睡眠情况的影响程度最小。结论本文应用SEM方法定量与定性的分析了人为因素对情景意识的影响及作用机制,符合实际情况,能够为规避人为差错引发的不安全事件提供科学依据。     

突发事件状况下管制员个体行为特点研究

由于人在生理、心理、社会和精神等方面,存在较大的可塑性和难控性的特点,因而在面临突发事件时,难免会做出错误的决策导致事故的发生或后果的加剧。本文主要探讨了Logit模型在管制员个体面对突发事件的运用,通过管制员个体心理偏差分析,定性和定量地分析突发事件状况下影响管制员个体行为因素,对民用航空安全的研究有参考价值。     

关于提高空中管制员的身体素质与心理能力研究

航空运输是我国重要的运输渠道，而安全是航空事业的首要任务，这就对空中管制员有较高的要求，特别是空管员的心理素质和身体素质要求十分高，管制员的心理素质的好坏对工作有着重要的影响，如何提高空管员的心理素质，是我们重点思考的问题。空中影响空中管制员心理素质的原因有很多，本文对加强心理能力进行了相应的探讨，而针对空管员的身体素质的提高，本文也提出了相应的对策，通过几点具体的措施来提高空管员的身体和心理素质，希望空中管制员的整体素质不断提高与完善，加强管制工作，为航空工作保驾护航。     

管制员工作负荷的研究

随着空域流量的增加，管制员工作负荷也随之增大。管制员的工作负荷已经发展成为制约扇区容量的最重要的因素之一。本文对管制员工作负荷的种类进行了研究，分析了管制员工作负荷的影响因素，在此基础上提醒管制员工作负荷对工作的影响。     

关于空中交通管制员初始选拔

引言 空中交通管制员的主要职责是维护空中交通秩序、保障空中交通畅通。因此,管制工作具有高强度、高风险和高度责任心的特点。这就要求空中交通管制员在实施空中交通管制工作时必须具备充沛的精力,高度的责任心和扎实的管制工作能力。本文介绍了将心理测量学应用于管制员选拔工作的方法,希望对我国管制员选拔工作体系的完善提供一个有利的借鉴,实现我国民航事业快速．健康、高效的发展。     

空管自动化系统中减轻管制员工作负荷方法初探

正在空中交通流量不断增加的情况下,空管自动化系统已成了保证安全和效率的重要手段。在保持管制员作为中心决策者的前提下,通过自动化设备代替管制员的部分工作,通过减少或简化复杂的任务,或通过综合信息,估计未来的发展,以及在高负荷时完成一些关键任务来增强人的效能。但提高自动化程度并不一定能减少管制员的负荷和提高效率,处理不好则将适得其反。虽然空管自动化系统能够有效的提高安全性和工作效率,但空管自动化系统的发展并不意味着管制员的工作量也会相应减少,对于如何既能够保障其工作的安全性和高效,又能够相应减轻管制员的负荷,以下作出了相关的探究和分析。文章中主要从管制员工作负荷的具体含义、影响因素等方面进行分析探索。     

基于特征加权的朴素贝叶斯流量分类方法研究

研究了被广泛应用于互联网流量分类的朴素贝叶斯分类方法的性能特点,针对此方法在给定类别下给出的所有流量特征同等重要并且是独立的假设在现实中难以满足,致使分类准确率不高的问题,提出一种基于特征加权的朴素贝叶斯流量分类算法。该算法基于NetFlow记录的特征信息,采用特征选择算法ReliefF和相关系数方法计算每个特征的权重值,然后将网络流量分配至后验概率最大的应用类别中。实验结果表明,这种基于特征加权的朴素贝叶斯算法具有超过94%的分类准确率,并且维持了朴素贝叶斯方法简单高效、分类稳定的特性,可以满足当前高带宽网络流量分类的需求。     

Burden of road traffic injuries: Disability-adjusted life years in relation to hospitalization and the maximum abbreviated injury scale

Background

The consequences of non-fatal road traffic injuries (RTI) are increasingly adopted by policy makers as an indicator of traffic safety. However, it is not agreed upon which level of severity should be used as cut-off point for assessing road safety performance. Internationally, within road safety, injury severity is assessed by means of the maximum abbreviated injury scale (MAIS). The choice for a severity cut-off point highly influences the measured disease burden of RTI. This paper assesses the burden of RTI in terms of disability adjusted life years (DALYs) by hospitalization status and MAIS cut-off point in the Netherlands.

Methods

Hospital discharge register (HDR) and emergency department (ED) data for RTI in the Netherlands were selected for the years 2007–2009, as well as mortality data. The incidence, years lived with disability (YLD), years of life lost (YLL) owing to premature death, and DALYs were calculated. YLD for admitted patients was subdivided by MAIS severity levels.

Results

RTI resulted in 48,500 YLD and 27,900 YLL respectively, amounting to 76,400 DALYs per year in the Netherlands. The largest proportion of DALYs is related to fatalities (37%), followed by admitted MAIS 2 injuries (25%), ED treated injuries (16%) and admitted MAIS 3+ injuries (18%). Admitted MAIS 1 injuries only account for a small fraction of DALYs (4%). In the Netherlands, the diseases burden of RTI is highest among cyclists with 39% of total DALYs. One half of all bicycle related DALYs are attributable to admitted MAIS 2+ injuries, but ED treated injuries also account for a large proportion of DALYs in this group (28%). Car occupants are responsible for 26% of all DALYs, primarily caused by fatalities (66%), followed by admitted MAIS 2+ injuries (25%). ED treated injuries only account for 5% of DALYs in this group.

Conclusions

When using admitted MAIS 3+ or admitted MAIS 2+ as severity cut-off point, 54% and 80% of all DALYs are captured respectively. Assessing the influence of different severity cut-off points by MAIS on the proportion and number of DALYs captured gives valuable information for guiding choices on the definition of serious RTI.     

ATM网中的MPEG标准VBR视频业务新模型

在分析ＭＰＥＧ－１标准下的可变比特率（ＶＢＲ）视频业务特性的基础上，对这类业务提出了一种新模型。仿真结果表明，该模型能够很好地逼近这类业务的统计特性。     

IP核心网中VoIP业务服务质量的初步研究

通过对比传统电话网的语音业务特点对IP核心网中的VoIP业务流进行了模拟,并通过仿真对IP核心网中VoIP业务流特性进行了观察分析。结果发现,大量VoIP业务汇聚产生的业务流具有突发性小、较平稳的流量特性,因而不必为其分配过多的带宽资源;研究了Internet自相似业务流特性对VoIP业务性能的影响,提出了在VoIP业务中采用高优先调度机制等技术来保障VoIP服务质量的网络设计原则。     

Genetic Study Identifies CBLN4 as a Novel Susceptibility Gene for Accident Proneness

Frequent traffic accidents constitute a major danger to human beings. The accident-prone driver who has the stable physiological, psychological, and behavioral characteristics is one of the most prominent causes of traffic accidents. The internal link between the individual characteristics and the accident proneness has been a difficult point in the accident prevention research. The authors selected accident-prone drivers as cases and safe drivers as controls (case-control group) from 18,360 drivers who were enrolled from three public transportation incorporations of China using area stratified sampling method. The case-control groups were 1:1 matched. The authors performed genome-wide association study (GWAS) by 179 cases and 179 controls using the U.S. Affymetrix Genome-Wide Human Mapping SNP 6.0 Array. The authors observed that the gene frequencies of 34 single-nucleotide polymorphisms (SNPs) in three regions of cases were higher than those in the control (P<10⁻⁴). The authors then tested two independent replication sets for strong association 6 SNPs in 349 pairs of case-control drivers using the U.S. ABI 3730 sequencing method. The results indicated that SNP rs6069499 within linked CBLN4 gene are strongly associated with accident proneness (P_combined=6.37×10⁻¹⁰). According to CBLN4 gene mainly involved in adrenal development and the regulation of secretion, the authors performed 12 biochemical parameters of the blood using radioimmunoassay. The levels of dopamine (DA) and adrenocorticotropic (ACTH) hormone showed significant differences between accident-prone drivers and safe drivers (P_DA=0.03, P_ACTH=0.01). It is suggested that the accident-prone drivers may have the idiosyncrasy of susceptibility.     

一种基于缓存交互的命名数据网络拥塞控制算法

研究了命名数据网络(NDN)的拥塞控制。为了解决突发流量问题和提高吞吐量及网络资源利用率,考虑了路由器缓冲区大小与拥塞控制机制的相互影响以及NDN内部署缓存这一重要特性,提出了一种基于缓存交互的NDN拥塞控制算法。该算法通过利用NDN中的路由器缓存,在逻辑上动态扩充缓冲区大小并控制Data包的发送速率,同时与现有的NDN拥塞控制算法相结合,动态调整Interest包发送速率阈值,以平滑突发流量,缓解网络拥塞。基于ndn SIM的仿真实验结果表明,该算法能有效提高NDN的传输效率、吞吐量和网络资源利用率。     

移动agent在智能交通系统中的应用

回顾了智能交通系统的起源、框架，在阐述移动agent的优点后，在网络管理、无线通信、交通控制系统、仿真系统、地理信息系统等方面探讨了移动agent在智能交通系统中的应用。     

SDN-Enabled Content Dissemination Scheme for the Internet of Vehicles

The content-centric networking (CCN) architecture allows access to the content through name, instead of the physical location where the content is stored, which makes it a more robust and flexible content-based architecture. Nevertheless, in CCN, the broadcast nature of vehicles on the Internet of Vehicles (IoV) results in latency and network congestion. The IoV-based content distribution is an emerging concept in which all the vehicles are connected via the internet. Due to the high mobility of vehicles, however, IoV applications have different network requirements that differ from those of many other networks, posing new challenges. Considering this, a novel strategy mediator framework is presented in this paper for managing the network resources efficiently. Software-defined network (SDN) controller is deployed for improving the routing flexibility and facilitating in the inter-interoperability of heterogeneous devices within the network. Due to the limited memory of edge devices, the delectable bloom filters are used for caching and storage. Finally, the proposed scheme is compared with the existing variants for validating its effectiveness.     

Real gas choked flow conditions at low reduced-temperatures

Real gas choked mass flux is calculated for a frictionless stream expanding isentropically until it reaches the speed of sound and without phase changes. The other parameters associated with the choked state are the pressure, density, temperature ratios, and the speed of sound. Departure of the choked mass flux from the ideal gas model is discussed first in absolute terms and then in relative terms, using the Principle of Corresponding States, for gases with boiling points in the low temperature range. Reduced-stagnation pressures are examined up to values of 30 for hydrogen, neon, nitrogen, argon, methane, krypton, xenon, and R-14 and up to 100 for ⁴He. The corresponding reduced-stagnation temperatures go down to 1.4 and in some cases down to 1.2 for nitrogen and argon. Also discussed are the limiting values of stagnation parameters for which no phase change occurs in the choked state. Compared to the ideal gas, the mass flux may almost double and the critical pressure ratio may decrease by an order of magnitude. The relevance of results is discussed qualitatively and quantitatively for Joule-Thomson cryocooling.     

As-cast microstructures and behavior at high temperature of chromium-rich cobalt-based alloys containing hafnium carbides

Hafnium is often used to improve the high temperature oxidation resistance of superalloys but not to form carbides for strengthen them against creep. In this work hafnium was added in cobalt-based alloys for verifying that HfC can be obtained in cobalt-based alloys and for characterizing their behavior at a very temperature. Three Co–25Cr–0.25 and 0.50C alloys containing 3.7 and 7.4 Hf to promote HfC carbides, and four Co–25Cr– 0 to 1C alloys for comparison (all contents in wt.%), were cast and exposed at 1200 °C for 50 h in synthetic air. The HfC carbides formed instead chromium carbides during solidification, in eutectic with matrix and as dispersed compact particles. During the stage at 1200 °C the HfC carbides did not significantly evolve, even near the oxidation front despite oxidation early become very fast and generalized. At the same time the chromium carbides present in the Co–Cr–C alloys totally disappeared in the same conditions. Such HfC-alloys potentially bring efficient and sustainable mechanical strengthening at high temperature, but their hot oxidation resistance must be significantly improved.