Latency and mode of error detection in a process industry

Licensee event reports (LERs) from an industry provide important information feedback about safety to the industry itself, the regulators and to the public. LERs from four nuclear power reactors were analyzed to find out about detection times, mode of detection and qualitative differences in reports from different reactors. The reliability of the codings was satisfactory and measured as the covariance between the ratings from two independent judges. The results showed differences in detection time across the reactors. On the average about 10% of the errors remained undetected for 100 weeks or more, but the great majority of errors were detected soon after their first appearance in the plant. On the average 40% of the errors were detected in regular tests and 40% through alarms. Operators found about 16% of the errors through noticing something abnormal in the plant. The remaining errors were detected in other ways. There were qualitative differences between the LERs from the different reactors reflecting the different conditions in the plants. The number of reports differed by a magnitude 1:2 between the different plants. However, a greater number of LERs can indicate both higher safety standards (e.g. a greater willingness to report all possible events to be able to learn from them) and lower safety standards (e.g. reporting as few events as possible to make a good impression). It was pointed out that LERs are indispensable in order to maintain safety of an industry and that the differences between plants found in the analyses of this study indicate how error reports can be used to initiate further investigations for improved safety.     

基于生理电的移动网页时延对体验质量的影响

目的从用户角度出发,研究移动设备网页浏览过程中网页时延与用户体验质量之间的关系。方法通过记录多类网页浏览过程中不同时延下用户皮电、心电两类生理指标的变化,利用方差分析以及t检验计算其特征值发生显著性差异时对应的时延长度并对该时延长度进行标记,结合MOS评分量表,对用户的主观感受作出评价。结果实验得到了较为可靠的结论,研究发现不同移动网页时延下用户的体验质量是不同的。用户在打开网页时的主观体验与网页的时延长度整体存在非线性负相关关系。结论当移动网页缓冲时延小于1 s时,用户体验良好;当时延超过1 s时,用户体验质量在一定时延范围内随时延增加而下降且该变化呈现较大的个人差异性;当时延超过4 s时,用户负面体验较为严重。     

具有差异延迟期的群体观点一致行为研究

研究个体在观点变化过程中存在延迟期对群体观点收敛时间和一致性的影响.从复杂系统的角度分析了群体观点演化的自组织特性,包括内部个体的对外界观点考虑和吸收的开放性,以及个体本身在观点变化过程中间存在差异延迟的因素.在此基础上,提出了一种开放性个体存在观点变化延迟期的动态群体观点演化模型.模型中的开放性是群体与外界产生信息交互的先决条件,并通过群体内部个体的特性体现出来.与传统研究中个体始终处于积极与相近观点个体发生交互不同的是,提出延迟期的概念,处于延迟期的个体自我封闭,群体结构通过这种状态的突变发生变化.借助于计算机仿真发现,差异延迟对群体的影响显著.在相同时间内,群体观点的一致性降低;不同延迟差异下,稳定性群体结构的波动也出现变化,并达成一致所用时间延长,结合实例分析验证模型的实效性.     

Towards Fully Secure 5G Ultra-Low Latency Communications: ACost-Security Functions Analysis

Future components to enhance the basic, native security of 5G networks are either complex mechanisms whose impact in the requiring 5G communications are not considered, or lightweight solutions adapted to ultra-reliable low-latency communications (URLLC) but whose security properties remain under discussion. Although different 5G network slices may have different requirements, in general, both visions seem to fall short at provisioning secure URLLC in the future. In this work we address this challenge, by introducing cost-security functions as a method to evaluate the performance and adequacy of most developed and employed non-native enhanced security mechanisms in 5G networks. We categorize those new security components into different groups according to their purpose and deployment scope. We propose to analyze them in the context of existing 5G architectures using two different approaches. First, using model checking techniques, we will evaluate the probability of an attacker to be successful against each security solution. Second, using analytical models, we will analyze the impact of these security mechanisms in terms of delay, throughput consumption, and reliability. Finally, we will combine both approaches using stochastic cost-security functions and the PRISM model checker to create a global picture. Our results are first evidence of how a 5G network that covers and strengthened all security areas through enhanced, dedicated non-native mechanisms could only guarantee secure URLLC with a probability of ∼55%.     

End-to-End Latency Evaluation of the Sat5G Network Based on Stochastic Network Calculus

Simultaneous use of heterogeneous radio access technologies to increase the performance of real-time, reliability and capacity is an inherent feature of satellite-5G integrated network (Sat5G). However, there is still a lack of theoretical characterization of whether the network can satisfy the end-to-end transmission performance for latencysensitive service. To this end, we build a tandem model considering the connection relationship between the various components in Sat5G network architecture, and give an end-to-end latency calculation function based on this model. By introducing stochastic network calculus, we derive the relationship between the end-to-end latency bound and the violation probability considering the traffic characteristics of multimedia. Numerical results demonstrate the impact of different burst states and different service rates on this relationship, which means the higher the burst of arrival traffic and the higher the average rate of arrival traffic, the greater the probability of end-to-end latency violation. The results will provide valuable guidelines for the traffic control and cache management in Sat5G network.     

Spatial summation of peripheral Gabor patches

Previous studies have specified the foveal pattern that is seen most efficiently, with the assumption that the waveform of the best pattern matches the impulse response of the most sensitive visual filter. We measured the threshold contrast for circular, collinear, and orthogonal Gabor stimuli of 6 Hz temporal frequency presented 7 deg above the fixation point. We found that the threshold contrast energy is minimal for a class of stimuli whose Fourier-spectra bandwidth is less than approximately 1 octave. These findings suggest that an energy algorithm might underlie spatial summation of peripheral Gabor patches. The different behavior of spatial summation in fovea and periphery might reflect the differences in pattern detectability across space in the central and peripheral visual fields. It is also possible that a coherent (cross-correlation) algorithm is employed in detection of foveal stimuli and that an incoherent (energy) algorithm is employed in detection of peripheral stimuli.     

Adaptive optics for peripheral vision

Understanding peripheral optical errors and their impact on vision is important for various applications, e.g. research on myopia development and optical correction of patients with central visual field loss. In this study, we investigated whether correction of higher order aberrations with adaptive optics (AO) improve resolution beyond what is achieved with best peripheral refractive correction. A laboratory AO system was constructed for correcting peripheral aberrations. The peripheral low contrast grating resolution acuity in the 20° nasal visual field of the right eye was evaluated for 12 subjects using three types of correction: refractive correction of sphere and cylinder, static closed loop AO correction and continuous closed loop AO correction. Running AO in continuous closed loop improved acuity compared to refractive correction for most subjects (maximum benefit 0.15?logMAR). The visual improvement from aberration correction was highly correlated with the subject's initial amount of higher order aberrations (p?=?0.001, R ^2?=?0.72). There was, however, no acuity improvement from static AO correction. In conclusion, correction of peripheral higher order aberrations can improve low contrast resolution, provided refractive errors are corrected and the system runs in continuous closed loop.     

Instrument for measuring peripheral angles of contact

Measurement Techniques -     

Transformative innovation policy or how to escape peripheral policy paradox in European research peripheral countries

The research peripheral countries (RPCs) are faced with the need to provide transformative change for long term sustainable development with scarce research and development resources which rests upon strengthening science base and the transformative innovation policy focused on societal and environmental challenges. The European Commission's proposal of a new recovery instrument – the Next Generation EU, incorporating the Recovery and Resilience Facility as a key instrument - is focused on green, sustainable, and digital economies, paving the way for a shift from the standard science, technology, and innovation (STI) policy towards transformative innovation policies which foster innovation focused on systematic change and sustainable socio-technical systems.This research seeks to understand the ways in which STI policy can contribute to the economic resilience and sustainable development of research peripheral countries and how STI policies can respond to new innovation policy paradigms, avoiding Europeanisation of STI policies and, ultimately, a peripheral policy paradox. Overcoming of the periphery paradox in STI policies requires unorthodox policy solutions to avoid inefficient replication of policy measures from advanced countries which pertain to science – industry cooperation to foster high tech industries and frontier research.This research proposes a new STI policy approach, based on interactions and interdependencies between standard STI policies for fostering scientific research and science-industry cooperation through transformative innovation policies. This policy allows for an experimental approach to policy-making, finding a way to best suit the national socio-economic context for the gradual replacement of the established socio-technical regime towards sustainable transitions. The fourth component of the new STI policy approach is the concept of the mission-oriented policy, which draws on frontier knowledge and large investments. Both new policy paradigms are discussed in order to highlight the pros and cons of their application in RPCs with regards to research capacities, socio-economic regimes/landscapes, and societal challenges.     

侧铣加工动力学建模及仿真

本文以两自由度的铣削加工为研究对象,建立了闭环的动态力～振动切削动力学仿真模型;应用模型仿真切削力与振动并与实测数据进行比较;证实该模型仿真切削力与振动的准确性。该结果对预测铣削力与振动,选择合适的切削参数具有实际意义。     

超声评估糖尿病周围神经病变的研究进展

糖尿病伴周围神经病变主要通过特征性体征和症状进行诊断,并由神经电生理试验等证实。超声技术不仅能对周围神经的结构做出精准的评估,还能了解其血管灌注及硬度变化等情况,提供糖尿病周围神经病变不同阶段的病理生理信息,其应用价值得到临床的广泛认可。文章针对二维灰阶超声、超声多普勒及超声弹性成像技术在糖尿病周围神经病变中的应用进行了综述。     

Fusional vergence response to local peripheral stimulation

Horizontal, convergent disparities were introduced between dichoptic stimuli confined to small regions of the peripheral retina. Stimuli were presented at 32 locations: radial positions varied in 5-deg increments up to 20 deg, while angular position varied in 45-deg steps. The stimulus size and disparity were scaled in accordance with the cortical magnification factor. Eye movements were objectively measured, and the relative contributions of the motor and nonmotor components to the fusional response were evaluated as a function of stimulus eccentricity and angular position. Vergence responses elicited by peripheral disparities had longer latencies and durations and were more asymmetric than the movements elicited by foveal disparities. The composition of the fusional response changed with the position of the stimulus. The largest percentage of motor compensation was observed for stimuli located either near the line of sight or directly above it. The variations in the size of the motor response with increasing eccentricity could not be explained by the cortical magnification factor.