Control of GaN inverted pyramids growth on c-plane patterned sapphire substrates

Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane patterned sapphire substrates(PSS)by metal organic vapor phase epitaxy(MOVPE).The influences of growth conditions on the surface morphol-ogy are experimentally studied and explained by Wulff constructions.The competition of growth rate among{0001},{1011},and{1122}facets results in the various surface morphologies of GaN.A higher growth temperature of 985°C and a lowerⅤ/Ⅲratio of 25 can expand the area of{}facets in GaN inverted pyramids.On the other hand,GaN inverted pyramids with almost pure{}facets are obtained by using a lower growth temperature of 930℃,a higherⅤ/Ⅲratio of 100,and PSS with pattern arrangement perpendicular to the substrate primary flat.

An anti-aliasing filtering of quantum images in spatial domain using a pyramid structure

As a part of quantum image processing,quantum image filtering is a crucial technology in the development of quantum computing.Low-pass filtering can effectively achieve anti-aliasing effects on images.Currently,most quantum image filterings are based on classical domains and grayscale images,and there are relatively fewer studies on anti-aliasing in the quantum domain.This paper proposes a scheme for anti-aliasing filtering based on quantum grayscale and color image scaling in the spatial domain.It achieves the effect of anti-aliasing filtering on quantum images during the scaling process.First,we use the novel enhanced quantum representation(NEQR)and the improved quantum representation of color images(INCQI)to represent classical images.Since aliasing phenomena are more pronounced when images are scaled down,this paper focuses only on the anti-aliasing effects in the case of reduction.Subsequently,we perform anti-aliasing filtering on the quantum representation of the original image and then use bilinear interpolation to scale down the image,achieving the anti-aliasing effect.The constructed pyramid model is then used to select an appropriate image for upscaling to the original image size.Finally,the complexity of the circuit is analyzed.Compared to the images experiencing aliasing effects solely due to scaling,applying anti-aliasing filtering to the images results in smoother and clearer outputs.Additionally,the anti-aliasing filtering allows for manual intervention to select the desired level of image smoothness.

全渠道BOPS模式下的交叉退货策略研究

针对全渠道BOPS模式下的退货策略问题,考虑产品匹配率、线上退货成本、交叉退货概率等因素,借助消费者效用函数,分别在BOPS模式下构建传统退货策略和交叉退货策略定价博弈模型,分析了交叉退货策略对全渠道零售商最优定价、收益及退货策略选择的影响。结果表明:零售商的定价和需求随着产品匹配率和交叉退货概率的增大而增大,随着线上退货成本的增大而减小;随着不便利系数的增加,交叉退货策略对零售商收益的影响减小;当产品匹配率较小且不便利系数很小或很大时,或者当产品匹配率较大且不便利系数中等时,宜采用交叉退货策略;当交叉退货概率和线上退货处理成本都较大时,不适合采用交叉退货策略。

BOP环境下企业社会创业合作网络演化研究——嵌入性理论视角

随着国家相关政策的推动以及企业开发新市场的内在需求,BOP市场逐渐引起一些大型企业的关注。基于嵌入性理论视角,以上市企业JY的社会创业活动为研究对象,深入探究了在BOP市场中构建跨部门合作网络的动态演化过程与内在作用机制,揭示了该企业构建跨部门合作网络的微观路径。研究发现:企业社会创业主体嵌入并构建新的跨部门合作网络可分为“孤岛”“二元化”和“多元化”3个阶段,企业要根据不同阶段网络模式下内部核心成员的行为模式及其变化趋势采取相应的BOP市场跨部门合作网络的构建策略。

Establishing a rat model of spastic cerebral palsy by targeted ethanol injection

Spastic cerebral palsy is generally considered to result from cerebral cortical or pyramidal tract damage. Here, we precisely targeted the left pyramidal tract of 2-month-old Sprague-Dawley rats placed on a stereotaxic instrument under intraperitoneal anesthesia. Based on the rat brain stereotaxic map, a 1-mm hole was made 10 mm posterior to bregma and 0.8 mm left of sagittal suture. A microsyringe was inserted perpendicularly to the surface of the brain to a depth of 9.7 mm, and 15 wL of ethanol was slowly injected to establish a rat model of spastic cerebral palsy. After modeling, the rats appeared to have necrotic voids in the pyramidal tract and exhibited typical signs and symptoms of flexion spasms that lasted for a long period of time. These findings indicate that this is an effective and easy method of establishing a rat model of spastic cerebral palsy with good reproducibility. Ethanol as a chemical ablation agent specifically and thoroughly damages the py- ramidal tract, and therefore, the animals display flexion spasms, which are a typical symptom of the disease.

PARTICLE SWARM OPTIMIZATION BASED ON PYRAMID MODEL FOR SATELLITE MODULE LAYOUT

To improve the global search ability of particle swarm optimization （PSO）, a multi-population PSO based on pyramid model （PPSO） is presented. Then, it is applied to solve the layout optimization problems against the background of an international commercial communication satellite （INTELSAT-Ⅲ） module. Three improvements are developed, including multi-population search based on pyramid model, adaptive collision avoidance among particles, and mutation of degraded particles. In the numerical examples of the layout design of this simplified satellite module, the performance of PPSO is compared to global version PSO and local version PSO （ring and Neumann PSO）. The results show that PPSO has higher computational accuracy, efficiency and success ratio.

Pyramid scheme in stock market:A kind of financial market simulation

Artificial stock market simulation based on agent is an important means to study financial market.Based on the assumption that the investors are composed of a main fund,small trend and contrarian investors characterized by four parameters,we simulate and research a kind of financial phenomenon with the characteristics of pyramid schemes.Our simulation results and theoretical analysis reveal the relationships between the rate of return of the main fund and the proportion of the trend investors in all small investors,the small investors'parameters of taking profit and stopping loss,the order size of the main fund and the strategies adopted by the main fund.Our work is helpful to explain the financial phenomenon with the characteristics of pyramid schemes in financial markets,design trading rules for regulators and develop trading strategies for investors.

Damage evolution and fragmentation behavior of pyramid cut blasting under uniaxial compression

Pyramid cut blasting is an essential form of inclined hole cut blasting,but the in-situ stress effect of pyramid cut blasting is rarely studied.Based on the research background of pyramid cut blasting in a deep rock mass,the size,volume,and fragment size distribution of the blasting cavity before and after uniaxial compression were analysed by a model test.Otherwise,the damage and effective stress of the pyramid cut blasting were analysed with LS-DYNA numerical simulation.The results show that the damage and fragmentation of pyramid cut blasting are not only affected by blasting stress wave and blasting gas,but also affected by uniaxial compression.Under the influence of uniaxial compression,the blasting stress wave and blasting gas are more likely to damage the rock mass parallel to the uniaxial compression direction near the connecting line of blasting hole,and make the volume of cavity larger and the fragment rate lower.Additionally,uniaxial compression has a prominent influence during the middle and late stages of blasting.

Shear behavior of intact granite under thermo-mechanical coupling and three-dimensional morphology of shear-formed fractures

The shear failure of intact rock under thermo-mechanical(TM)coupling conditions is common,such as in enhanced geothermal mining and deep mine construction.Under the effect of a continuous engineering disturbance,shear-formed fractures are prone to secondary instability,posing a severe threat to deep engineering.Although numerous studies regarding three-dimensional(3D)morphologies of fracture surfaces have been conducted,the understanding of shear-formed fractures under TM coupling conditions is limited.In this study,direct shear tests of intact granite under various TM coupling conditions were conducted,followed by 3D laser scanning tests of shear-formed fractures.Test results demonstrated that the peak shear strength of intact granite is positively correlated with the normal stress,whereas it is negatively correlated with the temperature.The internal friction angle and cohesion of intact granite significantly decrease with an increase in the temperature.The anisotropy,roughness value,and height of the asperities on the fracture surfaces are reduced as the normal stress increases,whereas their variation trends are the opposite as the temperature increases.The macroscopic failure mode of intact granite under TM coupling conditions is dominated by mixed tensileeshear and shear failures.As the normal stress increases,intragranular fractures are developed ranging from a local to a global distribution,and the macroscopic failure mode of intact granite changes from mixed tensileeshear to shear failure.Finally,3D morphological characteristics of the asperities on the shear-formed fracture surfaces were analyzed,and a quadrangular pyramid conceptual model representing these asperities was proposed and sufficiently verified.

Intelligent Agent Based Mapping of Software Requirement Specification to Design Model

Automatically mapping a requirement specification to design model in Software Engineering is an open complex problem. Existing methods use a complex manual process that use the knowledge from the requirement specification/modeling and the design, and try to find a good match between them. The key task done by designers is to convert a natural language based requirement specification (or corresponding UML based representation) into a predominantly computer language based design model—thus the process is very complex as there is a very large gap between our natural language and computer language. Moreover, this is not just a simple language conversion, but rather a complex knowledge conversion that can lead to meaningful design implementation. In this paper, we describe an automated method to map Requirement Model to Design Model and thus automate/partially automate the Structured Design (SD) process. We believe, this is the first logical step in mapping a more complex requirement specification to design model. We call it IRTDM (Intelligent Agent based requirement model to design model mapping). The main theme of IRTDM is to use some AI (Artificial Intelligence) based algorithms, semantic representation using Ontology or Predicate Logic, design structures using some well known design framework and Machine Learning algorithms for learning over time. Semantics help convert natural language based requirement specification (and associated UML representation) into high level design model followed by mapping to design structures. AI method can also be used to convert high level design structures into lower level design which then can be refined further by some manual and/or semi automated process. We emphasize that automation is one of the key ways to minimize the software cost, and is very important for all, especially, for the “Design for the Bottom 90% People” or BOP (Base of the Pyramid People).

The Non-Equivalence of Pyramids and Their Pseudo-Cones: Important New Insights

The simulation of indentations with so called “equivalent” pseudo-cones for decreasing computer time is challenged. The mimicry of pseudo-cones having equal basal surface and depth with pyramidal indenters is excluded by basic arithmetic and trigonometric calculations. The commonly accepted angles of so called “equivalent” pseudo-cones must not also claim equal depth. Such bias (answers put into the questions to be solved) in the historical values of the generally used half-opening angles of pseudo-cones is revealed. It falsifies all simulations or conclusions on that basis. The enormous errors in the resulting hardness HISO and elastic modulus Er-ISO values are disastrous not only for the artificial intelligence. The straightforward deduction for possibly ψ-cones (ψ for pseudo) without biased depths’ errors for equal basal surface and equal volume is reported. These ψ-cones would of course penetrate much more deeply than the three-sided Berkovich and cube corner pyramids (r a/2), and their half-opening angles would be smaller than those of the respective pyramids (reverse with r > a/2 for four-sided Vickers). Also the unlike forces’ direction angles are reported for the more sideward and the resulting downward directions. They are reflected by the diameter of the parallelograms with length and off-angle from the vertical axis. Experimental loading curves before and after the phase-transition onsets are indispensable. Mimicry of ψ-cones and pyramids is also quantitatively excluded. All simulations on their bases would also be dangerously invalid for industrial and solid pharmaceutical materials.

Pyramidal Edge Detection Method Based on AWFM Filtering and Fuzzy Linking Model

A novel multiresolution pyramidal edge detector, based on adaptive weighted fuzzy mean(AWFM)filtering and fuzzy linking model, is presented in this paper. The algorithm first constructs a pyramidal structure by repetitive AWFM filtering and subsampling of original image. Then it utilizes multiple heuristic linking criteria between the edge nodes of two adjacent levels and considers the linkage as a fuzzy model, which is trained offline. Through this fuzzy linking model, the boundaries detected at coarse resolution are propagated and refined to the bottom level from the coarse-to fine edge detection. The validation experiment results demonstrate that the proposed approach has superior performance compared with standard fixed resolution detector andprevious multiresolution approach, especially in impulse noise environment.

BOPS零售服务下全渠道供应链最优定价策略研究

本文研究实施"线上购买,线下取货"的BOPS全渠道模式下,制造商与线上、线下零售商在不同定价和服务价值策略之间的相互作用.利用修正的Hotelling模型刻画市场需求函数,构建以制造商为主导的Stackelberg供应链模型,分析了集中式双渠道、集中式全渠道、分散式双渠道和分散式全渠道4种策略的均衡定价与服务价值,并用数值仿真的方法对4种策略进行比较.研究表明,零售商的服务价值对供应链成员的定价均有正向影响;实施BOPS全渠道定价策略明显优于双渠道定价策略,并且全渠道策略的优势在集中式供应链的效果比分散式供应链更加明显.同时敏感性分析表明,供应链的整体收益随着BOPS渠道的市场规模扩张系数的增加而增加;最优的定价策略为集中式全渠道策略.

基于改进YOLOv5s的轻量级绝缘子缺失检测

针对现有绝缘子缺失检测模型计算复杂度高和小目标难以检测等问题,提出一种基于改进的YOLOv5s轻量级检测模型。首先,移除主干网络中的C3模块来减少模型的参数量。其次,在多尺度特征融合网络中引入卷积块注意力机制来提高复杂背景下模型的特征提取能力。同时,采用加权双向特征金字塔网络结构对特征进行双向跨尺度加权融合,提升网络在遮挡物、相似目标干扰下目标的检测性能。最后,选用SIoU损失函数提升网络的收敛速度和检测精度。实验结果表明,所提模型的平均精准率为96.8%,浮点运算数为2.8 GFLOPS,而原始YOLOv5s在保证97.4%的平均精准率下的浮点运算数为16.3 GFLOPS。相较于原始模型,所提模型对小目标、遮挡目标以及模糊等场景有着较强的鲁棒性,且在保证近似检测精度的同时极大减少了计算量。

面向BOP的数字医疗助理设计

为提高医疗资源的利用效率、抑制日益增长的医疗费用和应对老龄化、慢性病的挑战,设计了一套面向低收入群体(BOP) 的由移动监护、数据传输、管理等模块组成的数字医疗助理系统。文中给出了系统的评估方法,并讨论了数字医疗助理的应用模式和服务流程。

基于轻量级SE-PPM的自然状态烟叶正副组分类算法

【目的】针对自然状态烟叶传统正副组分类速度慢、正副组易错分、特征提取困难的问题,提出了一种基于轻量级SE-PPM的自然状态烟叶正副组分类算法(SAPMDSNet)。【方法】基于轻量级ShuffleNetV2网络,先通过降低网络卷积深度和进化激活函数,加快网络模型的训练速度;再引入通道注意力机制SE模块,增强通道间的特征差异,提高网络模型的表征能力,避免正副组烟叶叶部区域化导致的组别错分;最后通过嵌入金字塔池化模块PPM充分融合烟叶显露特征与全局信息,增强对正副组烟叶上下文信息的聚合,并采用自行构建的烟叶数据集进行对比试验。【结果】SAPMDSNet网络模型的分类准确率为91.09%,计算量(FLOPs)为151.70 M,取得了相对较高的分类效果。与原网络ShuffleNetV2模型和轻量级GhostNet模型相比,SAPMDSNet网络模型的FLOPs分别升高2.65%和2.84%,而识别准确率则分别提高2.72和21.13个百分点;MobileNetV2、DenseNet和SqueezeNet模型的识别准确率分别为87.02%,89.53%和87.60%,虽均与SAPMDSNet模型的识别准确率接近,但其FLOPs明显较SAPMDSNet模型大。【结论】构建的SAPMDSNet模型能提高烟叶正副组分类精度且具有较好的整体性能,为烤烟烟叶品质初筛提供了新的思路和方法。

BOP诱导叙利亚仓鼠胰腺癌动物模型建立和相关生物学特性的研究

目的:探讨N-亚硝酸2-双丙基胺[bis-(2-oxopropyl)-N-nitro samine,BOP]诱导建立叙利亚仓鼠胰腺癌动物模型的可行性和建模过程特点,初步分析模型胰腺癌的相关生物学特点,为胰腺癌动物模型研究提供一个可控性强、动态、全面的基础。方法:73只叙利亚仓鼠随机分为实验组和对照组,实验组予以生理盐水稀释成20 mg/ml的BOP按照20 mg/kg体重腹壁皮下注射每周1次,连续4周;相同条件注射生理盐水为对照组。连续监测各组仓鼠体重,注射结束后4周开始每2周依次收集两组叙利亚仓鼠组织标本,观测其形态特点。结果:注射后20周实验组开始出现胰腺肿瘤,注射后28周开始成瘤明显增加,病理观测为低分化腺癌,复种实验成功,部分实验结果与既往报道不一致。结论:BOP可以成功构建叙利亚仓鼠胰腺低分化腺癌动物模型,在注射后第28周后收集标本时间最佳,部分实验结果值得进一步深入研究。

改进的语义分割模型及其应用

训练语义分割网络模型需要较为繁琐的人工标注作为训练标签,同时语义分割模型在构建和运行过程中也存在超参数较难确定以及模型过于庞大等问题。为解决这类问题,提出了一种基于标注框生成热点图的标签生成方法,简化了语义分割训练标签的人工标注过程。以及在可微分神经网络结构搜索方法的基础上提出了一种对硬件要求更低的神经网络结构搜索方法,并基于此种方法改进了特征金字塔结构,构建了一个改进的语义分割模型,并在安全帽与口罩检测数据集上进行了试验。与U-Net、FPN等模型比较,新的模型在参数量、计算速度以及精确度上都更有优势。

基于L-FPN的无人机上小目标识别模型轻量化方法

由于遥感图像拍摄的高度和设备不同导致每张图像的地面采样间隔(GSD)也不同,许多小目标往往易被忽略,遥感图像中旋转框目标检测成为当下研究热点。现有的旋转框检测算法主要面向通用场景下的多尺度目标检测,特征金字塔中特征融合计算操作复杂且耗时,部署到无人机上的边缘端设备时面临很大的挑战。因此本文针对该场景下的小目标检测提出基于L-FPN的无人机上小目标识别模型轻量化方法,首先依据图像的GSD信息进行尺度归一化,然后去除特征金字塔中冗余的高层特征图,最后针对小目标检测调整锚框的尺寸。本方法在DOTA数据集上进行训练验证,结果表明本文提出的基于L-FPN的无人机上小目标识别模型轻量化方法在识别精度与传统模型一致的情况下,模型参数量较原模型减少2.7%,模型大小减少28%,推理速度提升13.24%。

氧化锌电阻片侧面绝缘涂层自动滚涂设备设计

为提高氧化锌电阻片的生产环节自动化水平,课题组设计了一种针对电阻片侧面绝缘涂层自动滚涂设备。设计了自动滚涂机构,由2个滚轴分别实现电阻片的滚涂和均匀刮抹;基于改进的YOLOv8模型的点位检测算法设计了基于视觉引导的拆垛机构,在YOLOv8中融入了动态稀疏注意力(bi-level routing attention, BRA)模块并将特征融合方式改为双向特征金字塔网络(bidirectional feature pyramid network, BiFPN)。与原有YOLOv8模型相比,改进的YOLOv8在识别精度上取得了显著的提升,平均均值精度(mean average precision, mAP)从92.8%提升至95.3%,从而在实际应用中降低了电阻片的漏检率和错检率,使漏检率相对减少了26.2%,错检率相对减少了33.3%。自动涂绝缘层设备为电阻片涂覆提供了高效的自动化解决方案。