基于端到端深度神经网络和图搜索的OCT图像视网膜层边界分割方法

视网膜层边界的形态变化是眼部视网膜疾病出现的重要标志, 光学相干断层扫描(optical coherence tomography, OCT)图像可以捕捉其细微变化, 基于OCT图像的视网膜层边界分割能够辅助相关疾病的临床判断. 在OCT图像中, 由于视网膜层边界的形态变化多样, 其中与边界相关的关键信息如上下文信息和显著性边界信息等对层边界的判断和分割至关重要. 然而已有分割方法缺乏对以上信息的考虑, 导致边界不完整和不连续. 针对以上问题, 提出一种“由粗到细”的基于端到端深度神经网络和图搜索(graph search, GS)的OCT图像视网膜层边界分割方法, 避免了非端到端方法中普遍存在的“断层”现象. 在粗分割阶段, 提出一种端到端的深度神经网络—注意力全局残差网络(attention global residual network, AGR-Net), 以更充分和有效的方式提取上述关键信息. 具体地, 首先设计一个全局特征模块(global feature module, GFM), 通过从图像的4个方向扫描以捕获OCT图像的全局上下文信息; 其次, 进一步将通道注意力模块(channel attention module, CAM)与全局特征模块串行组合并嵌入到主干网络中, 以实现视网膜层及其边界的上下文信息的显著性建模, 有效解决OCT图像中由于视网膜层形变和信息提取不充分所导致的误分割问题. 在细分割阶段, 采用图搜索算法去除AGR-Net粗分割结果中的孤立区域或和孔洞等, 保持边界的固定拓扑结构和连续平滑, 以实现整体分割结果的进一步优化, 为医学临床的诊断提供更完整的参考. 最后, 在两个公开数据集上从不同的角度对所提出的方法进行性能评估, 并与最新方法进行比较. 对比实验结果也表明所提方法在分割精度和稳定性方面均优于现有方法.     

大中型发电机组励磁装置中的数字式脉冲移相电路

为解决普通三相全控整流桥脉冲移相电路的不足,采用单片机及数字移相技术,自行设计和制造出大功率的数字式脉冲移相电路,应用于大中型发电机组励磁装置中。文章给出了数字式脉冲移相电路的硬件组成和软件设计。实际应用证明,该数字触发电路性能优越、稳定可靠,能够更好地满足大中型发电机组励磁设备的技术要求。     

医院门诊“一卡通”系统的设计与开发

为了减少患者门诊就诊不必要的等待时间,提高患者的就诊效率,优化门诊就医流程,本文研究与设计了门诊“一卡通”系统.采用Client/Server体系结构,以基于HIS系统的Oracle后台数据库为基础,应用PowerBuilder 9.0为前台开发工具开发系统的各个模块.该系统的实施达到了优化就医流程、方便患者、提高医院门诊服务水平及整体运作效率的目的.该系统适合在医院推广使用,对提升“以病人为中心”的服务理念及医院信息化建设水平具有重要的意义.     

Effects of amounts of HMW glutenin subunits determined by capillary electrophoresis on technological properties in wheat doubled haploids

BACKGROUND: Knowledge of the types and amounts of individual HMW glutenin subunits (HMW-GS) is important for predicting technological quality. In this study, 228 wheat doubled haploids were compared in respect of HMW-GS composition, seed protein content, flour yield, rheological properties of dough, and loaf properties. The quantitative and qualitative composition of particular HMW-GS was determined by CE. The relative amounts of x-type and y-type subunits encoded by individual Glu-1 loci were considered. RESULTS: The results show that the amounts of some pairs x + y of HMW-GS are correlated with technological properties. The importance of quantities of particular pairs of HMW-GS for technological values depends on allele compositions in all the Glu-1 loci. Positive correlation was found between the amount of subunits Ax1, Ax2*, Bx7 + By8 or Dx5 + Dy10 and loaf volume (r = 0.215–0.618, P < 0.05). The influence of an increasing amount of Ax1 was positively correlated with dough softening (r = 0.451, P < 0.01) and negatively with dough development time (r = − 0.209, P < 0.05) and stability (r = − 0.351, P < 0.01), whereas for subunit Ax2* these associations were opposite. CONCLUSION: The results confirm the occurrence of epistatic interactions between alleles of Glu-1 loci. The effects of amounts of HMW subunits on bread-making quality should be considered only within glutenin subunit compositions. Copyright © 2008 Society of Chemical Industry     

LPCB认证中对火灾报警控制器的基本要求

以智能火灾报警控制器为例,详细说明了EN 54-2标准对于火灾报警控制器的要求。通过和国家标准GB 4717的对比分析,阐述了EN 54-2和GB 4717的区别。最后给出了LPCB认证的主要流程,对于我国火灾报警产品进行LPCB认证具有重要的意义。     

GS1牛肉全程质量追溯系统框架研究

GS1 是EAN/UCC 的新名字,由编码体系、可自动识别的数据载体和电子数据交换标准组成的全球统一标准。本文基于GS1 标准,针对“源头”追溯、标准化、动态数据共享等难题,搭建了牛肉全过程质量追溯系统的通用框架。框架中个体标识采用RFID 耳标与EAN/UCC 条码,RFID 耳标编码采用EPCglobal 标签数据标准;各流通环节的信息服务器采用三层架构：访问层、业务层、资源层,异构分布架设,以HTTP/SOAP 协议提供用户访问接口;采用信息发现服务结合对象名服务,定位动态分布的信息服务器,实现动态数据共享。     

Structure and shape memory effect in a Ni54Mn25Ga20Gd1 alloy with a high transformation temperature

Ni₅₄Mn₂₅Ga₂₀Gd₁ (at.%) alloy with a high transformation temperature has been obtained by substituting 1 at.% Gd for Ga in a ternary Ni₅₄Mn₂₅Ga₂₁ shape memory alloy. The microstructure and phase transformations in the Ni₅₄Mn₂₅Ga₂₀Gd₁ alloy have been investigated by SEM, TEM, XRD and DSC. The results show that the microstructure of the Ni₅₄Mn₂₅Ga₂₀Gd₁ alloy consists of matrix and hexagonal Gd (Ni,Mn)₄Ga phase, and martensitic transformation start temperature (M_s) is 491 K. The compressive strength and the compressive strain are about 958 MPa and 16%, respectively. The complete recovery is obtained from the Ni₅₄Mn₂₅Ga₂₀Gd₁ alloy as the pre-strains are no more than 3%. The maximum shape memory strain is achieved in Ni₅₄Mn₂₅Ga₂₀Gd₁ alloy with pre-strain of 4%, and the shape memory strain and recovery ratio are 1.9% and 87.5%, respectively. The two-way shape memory effect is also observed in Ni₅₄Mn₂₅Ga₂₀Gd₁ alloy.     

用DEA方法评价火力发电厂及其机组效率

采用DEA方法中的C2R模型和C2GS2模型对火力发电厂及其机组进行生产效率的相对有效性分析,分别从3个层面进行分析并建立模型,即:电力系统内不同发电企业生产经营效益的相对有效性分析;电力系统内不同发电机组生产效益的相对有效性分析;电厂内部不同发电机组生产效益的相对有效性分析。     

Stabilization of some fractional delay systems of neutral type

In this note, we give new stability tests which enable one to fully characterize the H_∞-stability of systems with transfer function , where h>0 and p,q,r are real polynomials in the variable s^μ for 0<μ<1.As an application of this, in the case r(s)=1 and degp=degq=1, families of H_∞-stabilizing controllers are given and a complete parametrization of all H_∞-stabilizing controllers is obtained when .     

Novel thermally stable,high quality factor Ba4(Pr0.4Sm0.6)28/3Ti18−yGa4y/3O54 microwave dielectric ceramics

High dielectric constant Ba₄(Pr_0.4Sm_0.6)_28/3Ti_18−yGa_4y/3O₅₄ (BPSTG) (0 ≤ y ≤ 1) microwave ceramics with enhanced dielectric properties were synthesized via the traditional solid-state processing for the first time. The crystal structure, microstructure, and microwave dielectric characteristics were investigated in details. X-ray diffraction results showed that all well-sintered samples belonged to a single tungsten bronze type phase. Results showed that partial substitution of Ga³⁺ for Ti⁴⁺ is an effective way in adjusting the temperature coefficient of resonant frequency (TCF) value of the Ba₄(Pr_0.4Sm_0.6)_28/3Ti₁₈O₅₄ ceramics and increased the quality factor (Qf) values. The variation tendency of dielectric constant was in accordance with the ionic polarizability. The Qf values highly depend on the grain size from the scanning electron microscopy results. A near zero TCF value can be obtained by carefully adjusting the substitution of Ga³⁺ content. Infrared reflectivity (FIR) spectra were employed to reveal the relationship between the phonons and microwave dielectric properties. At last, excellent combinations dielectric properties of ε_r = 78.5, Qf = 12,400 GHz, TCF = +2.1 ppm/°C were achieved in BPSTG ceramics when y = 0.75.