桥梁工程可靠度2020年度研究进展

由于自身固有属性的不确定性以及所处环境的复杂性,桥梁在设计、施工、运营等不同阶段都需要具备足够的可靠性。为了解2020年桥梁工程可靠度研究与应用的最新动态,查阅文献并对相关理论方法、不同阶段或环节的科研内容和成果进行归纳。在桥梁可靠度理论和方法方面,引入GPR模型、径向基神经网络等方式得到隐式结构功能函数,引入Copula理论把握多失效模式概率的关系;采用概率可靠性和非概率可靠性方法、蒙特卡罗数值模拟、时变可靠度理论等进行可靠性评估。既有桥梁的技术状况及可靠度仍然是桥梁工程领域研究的热点,自然环境条件下桥梁抗力与外荷载的时变模型是桥梁时变可靠度分析与寿命预测的重点。可靠度理论及分析方法在桥梁工程设计中得到逐步的发展,考虑动态荷载作用随机性与结构参数随机性的动力可靠度研究与应用越来越多。     

The Irish dairy industry – Recent history and strategy,current state and future challenges

This study explores drivers and resulting changes in the structure and technical efficiency of Irish dairy farms from 2005 to 2018 (covering pre‐ and post‐milk quotas) during which milk production increased by 54%. Over this period, farm structure changed dramatically (fourfold increase in farmers milking >100 cows) and farmers improved technical efficiency and profitability and reduced the greenhouse gas emission intensity of milk produced. The impact of the adoption of key technologies at farm level and the contribution of strategic direction nationally (the Irish Government's Food Harvest 2020 Strategy) influencing this development are explored as are future sector challenges.     

TransformerG:基于层级图结构与文本注意力机制的法律文本多跳阅读理解

该文针对Cail2020法律多跳机器阅读理解数据集进行研究,提出了TransformerG,一个基于不同层级的实体图结构与文本信息的注意力机制融合的多跳阅读理解模型。该模型有效地结合了段落中问题节点、问题的实体节点、句子节点、句中的实体节点的特征与文本信息的特征,从而预测答案片段。此外,该文提出了一种句子级滑动窗口的方法,有效解决在预训练模型中文本过长导致的截断问题。利用TransformerG模型参加中国中文信息学会计算语言学专委会(CIPS-CL)和最高人民法院信息中心举办的“中国法研杯”司法人工智能挑战赛机器阅读理解赛道,取得了第2名的成绩。     

Environmental and economic analysis of solar systems in Madeira,Portugal

The solar market started growing in Madeira from 2008 to profit from great solar exposition. Initially, there was a strong investment, but the removal of the Feed-in Tariffs, and self-consumption regulations caused stagnation in new solar systems. This policy change is relevant to check the current lack of investments and an analysis of the environmental and economic effects over a decade is necessary to help defining the solar policy for the next decades. Results show savings of 100 thousand tons of CO2 and 38 million euros supporting the need of policy reversal to address a change in the net-metering regime.     

基于APD的紫外光语音通信系统设计

设计了一套基于雪崩光电二极管(APD)的紫外光语音通信系统,系统分为硬件电路、软件和光学系统三个部分.采用先进多带激励(AMBE)编码和开关键控(OOK)调制技术,使语音通信速率降低到2.5kb/s.实验表明,该系统在光功率仅为纳瓦量级时仍能完成实时语音通信,系统的研制对日盲APD的制造和应用具有现实的指导意义.     

Land use changes, greenhouse gas emissions and fossil fuel substitution of biofuels compared to bioelectricity production for electric cars in Austria

Bioenergy is one way of achieving the indicative target of 10% renewable energy in the transportation sector outlined in the EU Directive 2009/28/EC. This article assesses the consequences of increasing the use of bioenergy for road transportation on land use, greenhouse gas (GHG) emissions, and fossil fuel substitution. Different technologies, including first and second generation fuels and electric cars fuelled by bioelectricity are assessed in relation to existing bioenergy uses for heat and power production. The article applies a spatially explicit energy system model that is coupled with a land use optimization model to allow assessing impacts of increased biomass utilization for energy production on land use in agriculture and forest wood harvests. Uncertainty is explicitly assessed with Monte-Carlo simulations of model parameters. Results indicate that electric mobility could save GHG emissions without causing a significant increase in domestic land use for energy crop production. Costs of electric cars are still prohibitive. Second generation biofuels are more effective in producing fuels than first generation ethanol. However, competition with power and heat production from ligno-cellulosic feedstock causes an increase in GHG emissions when introducing second generation fuels in comparison to a baseline scenario.     

2010—2020年山西电网主结构规划探讨

探讨了山西电网主结构规划,认为经过10a急速发展期之后,2010～2020年山西电网将迎来平稳发展期。2010—2020年山西电网主网架以500kV南北纵向通道为主,横向通道适当联络。500kV电网主网架形成并不断加强的同时,全省电网逐步解开500／220kV电磁环网,实现分层分区运行。     

Denitrification of Wastewater: Operating Experiences in the US and Pilot-Plant Studies in the UK

Due to the EC urban wastewater treatment Directive, considerable attention has been focused on nitrogen removal, particularly from biological filter nitrified effluents. The paper presents a reliable and proven full-scale fixed-film denitrification system installed in the US and evaluated on pilot scale by Severn Trent Water. Methanol has been used as a carbon source dosed prior to the deep-bed sand filter. The filter removes considerable suspended solids as well as providing the hydraulic retention and surface area for the growth of the biological denitrifying bacteria. Flow sheets of typical US installations are given and operational data with costs are presented for the pilot-plant evaluation.     

A Hybrid Attention-Based Residual Unet for Semantic Segmentation of Brain Tumor

Segmenting brain tumors in Magnetic Resonance Imaging (MRI) volumes is challenging due to their diffuse and irregular shapes. Recently, 2D and 3D deep neural networks have become famous for medical image segmentation because of the availability of labelled datasets. However, 3D networks can be computationally expensive and require significant training resources. This research proposes a 3D deep learning model for brain tumor segmentation that uses lightweight feature extraction modules to improve performance without compromising contextual information or accuracy. The proposed model, called Hybrid Attention-Based Residual Unet (HA-RUnet), is based on the Unet architecture and utilizes residual blocks to extract low- and high-level features from MRI volumes. Attention and Squeeze-Excitation (SE) modules are also integrated at different levels to learn attention-aware features adaptively within local and global receptive fields. The proposed model was trained on the BraTS-2020 dataset and achieved a dice score of 0.867, 0.813, and 0.787, as well as a sensitivity of 0.93, 0.88, and 0.83 for Whole Tumor, Tumor Core, and Enhancing Tumor, on test dataset respectively. Experimental results show that the proposed HA-RUnet model outperforms the ResUnet and AResUnet base models while having a smaller number of parameters than other state-of-the-art models. Overall, the proposed HA-RUnet model can improve brain tumor segmentation accuracy and facilitate appropriate diagnosis and treatment planning for medical practitioners.     

CPS1432交换芯片的串行RapidIO互连技术

RapidIO技术是世界上第一个、也是目前唯一的嵌入式系统互连国际标准(ISO/IEC18372),串行RapidIO是针对高性能嵌入式系统芯片间和板间互连而设计的。本文介绍了CPS1432交换芯片与P2020组成的星型拓扑网络结构,包括硬件设计方案和软件设计要点,对高性能嵌入式互连设计具有很好的借鉴意义。