Error model identification of inertial navigation platform based on errors-in-variables model

Because the real input acceleration cannot be obtained during the error model identification of inertial navigation platform, both the input and output data contain noises. In this case, the conventional regression model and the least squares （LS） method will result in bias. Based on the models of inertial navigation platform error and observation error, the errors-in-variables （EV） model and the total least squares （TLS） method axe proposed to identify the error model of the inertial navigation platform. The estimation precision is improved and the result is better than the conventional regression model based LS method. The simulation results illustrate the effectiveness of the proposed method.

Uncertain optimal model and solving method to platform scheduling problem in battlefield

The platform scheduling problem in battlefield is one of the important problems in military operational research.It needs to minimize mission completing time and meanwhile maximize the mission completing accuracy with a limited number of platforms.Though the traditional certain models obtain some good results,uncertain model is still needed to be introduced since the battlefield environment is complex and unstable.An uncertain model is prposed for the platform scheduling problem.Related parameters in this model are set to be fuzzy or stochastic.Due to the inherent disadvantage of the solving methods for traditional models,a new method is proposed to solve the uncertain model.Finally,the practicability and availability of the proposed method are demonstrated with a case of joint campaign.

Numerical Modeling of a Spar Platform Tethered by a Mooring Cable

Virtual simulation is an economical and efficient method in mechanical system design. Numerical modeling of a spar platform, tethered by a mooring cable with a spherical joint is developed for the dynamic simulation of the floating structure in ocean. The geometry modeling of the spar is created using finite element methods. The submerged part of the spar bears the buoyancy, hydrodynamic drag force, and effect of the added mass and Froude-Krylov force. Strip theory is used to sum up the forces acting on the elements. The geometry modeling of the cable is established based on the lumped-mass-and-spring modeling through which the cable is divided into 10 elements. A new element-fixed local frame is used, which is created by the element orientation vector and relative velocity of the fluid, to express the loads acting on the cable. The bottom of the cable is fixed on the seabed by spring forces, while the top of the cable is connected to the bottom of the spar platform by a modified spherical joint. This system suffers the propagating wave and current in the X-direction and the linear wave theory is applied for setting of the propagating wave. Based on the numerical modeling, the displacement-load relationships are analyzed, and the simulation results of the numerical modeling are compared with those by the commercial simulation code, Proteus DS. The comparison indicates that the numerical modeling of the spar platform tethered by a mooring cable is well developed, which provides an instruction for the optimization of a floating structure tethered by a mooring cable system.

Statistical Modeling of the High Altitude Platform Dual-Polarized MIMO Propagation Channel

In order to investigate the benefit of multiple-input multiple-output(MIMO) technique applying to the high altitude platform(HAP), a 2×2 MIMO statistical model, which can accurately describe the channel between HAP and high-speed train, is presented. And dual polarization diversity is particularly considered. Based on first-order three-state Markov chain, the single-input single-output(SISO) channel, a subset of the MIMO channel is first established. The ray tracing approach applied to the digital relief model(DRM) which covers the railway between Xi'an and Zhengzhou is used to obtain the state probability vector and matrix of the state transition probability. The proposed model considers both Doppler shift and temporal correlation, and the polarization correlation and spatial correlation statistical properties of large-scale fading and smallscale fading are analyzed. Moreover, useful numerical results on the MIMO HAP channel outage capacity are provided based on which, significant capacity gains with respect to the conventional SISO case are illustrated. Such statistical channel model can be applied to the future wireless communication system between HAP and high-speed train.

Model Refinement for Offshore Platforms： Experimental Study

Offshore jacket platforms are widely used in offshore oil and gas exploitation.Finite element models of such structures need to have many degrees of freedom(DOFs) to represent the geometrical detail of complex structures,thereby leading to incompatibility in the number of DOFs of experimental models.To bring them both to the same order while ensuring that the essential eigen-properties of the refined model match those of experimental models,an extended model refinement procedure is presented in this paper.Vibration testing of an offshore jacket platform model is performed to validate the applicability of the proposed approach.A full-order finite element model of the platform is established and then tuned to meet the measured modal properties identified from the acceleration signals.Both model reduction and modal expansion methods are investigated,as well as various scenarios of sensor arrangements.Upon completion of the refinement,the updated jacket platform model matches the natural frequencies of the measured model well.

Nonlinear optimal model and solving algorithms for platform planning problem in battlefield

Platform planning is one of the important problems in the command and control(C2) field. Hereto, we analyze the platform planning problem and present nonlinear optimal model aiming at maximizing the task completion qualities. Firstly, we take into account the relation among tasks and build the single task nonlinear optimal model with a set of platform constraints. The Lagrange relaxation method and the pruning strategy are used to solve the model. Secondly, this paper presents optimization-based planning algorithms for efficiently allocating platforms to multiple tasks. To achieve the balance of the resource assignments among tasks, the m-best assignment algorithm and the pair-wise exchange(PWE)method are used to maximize multiple tasks completion qualities.Finally, a series of experiments are designed to verify the superiority and effectiveness of the proposed model and algorithms.

Three-dimensional cell culture systems as an in vitro platform for cancer and stem cell modeling

Three-dimensional(3D)culture systems are becoming increasingly popular due to their ability to mimic tissue-like structures more effectively than the monolayer cultures.In cancer and stem cell research,the natural cell characteristics and architectures are closely mimicked by the 3D cell models.Thus,the 3D cell cultures are promising and suitable systems for various proposes,ranging from disease modeling to drug target identification as well as potential therapeutic substances that may transform our lives.This review provides a comprehensive compendium of recent advancements in culturing cells,in particular cancer and stem cells,using 3D culture techniques.The major approaches highlighted here include cell spheroids,hydrogel embedding,bioreactors,scaffolds,and bioprinting.In addition,the progress of employing 3D cell culture systems as a platform for cancer and stem cell research was addressed,and the prominent studies of 3D cell culture systems were discussed.

Pig Price Fluctuations and Forecasting Model Based on Information Platform

Pork is common in people's daily life consumption,and it accounts for more than half of all meats. By collecting data information published by Bureau of Statistics and Bureau of Agriculture,this paper makes a statistical analysis of the influence of price fluctuation in the pork market on China's pork production,and finds that China's pork production shows a general trend of fluctuations due to the impact of price factors.According to the predecessors' studies on the factors influencing pig market price,combined with the actual situation of pig breeding in China,this paper uses the latest website data released by the government's public information platform to establish a forecasting model.

Modeling the Pressure Distribution and the Changes of Water Level around the Offshore Platforms Exposed to Waves, Using the Numerical Model of Flow 3D

The humans’ need to use the oceans for exploration and extraction of oil has led to the development of engineering science in the field of offshore structures. Since it’s important to examine the offshore structures from different aspects and perspectives, we would have to evaluate many different parameters about them. So categorizing these parameters can help to perform their related analysis with more accuracy and more details. Due to the efficient force it exerts on the structure, the pressure distribution around every marine or hydraulic structure has a significant importance, and it even accounts for one of the dominant issues in designing and building of such structures. In the present study, an oil platform located in Phase 15 of South Pars oil fields, located in the Persian Gulf waters, has been analyzed using the FLOW 3D software. The outputs indicate that the pressure of water is distributed almost hydrostatically with the depth, and its maximum reaches 0.6 MPa at the bottom.

Utilizing Occupancy Models and Platforms-of-Opportunity to Assess Area Use of Mother-Calf Humpback Whales

The Hawaiian Islands, and particularly the Maui 4-island region, are a critical breeding and calving habitat for humpback whales (Megaptera novaeangliae) belonging to the Hawaii distinct population segment. Our aims were to test the use of platforms-of-opportunity to determine trends in mother-calf pod use of the region and to present opportunistic platforms as an alternative method of long-term, cross-seasonal monitoring. Data were collected from whale watching vessels over a 4-year period and analyzed using occupancy models to determine the probability of habitat use of pods with calves and pods without calves within the study area. Detection probability was influenced by survey effort and month for all pod types with detection of adult only pods further influenced by year. Pods with a calf showed a preference for shallow (<100 meters) low latitude waters (<20.7°N), while pods without a calf preferred deeper waters (>75 meters). Results presented here align with previous work, both in Hawaii and in other breeding grounds, which show a distinct segregation of mothers with a calf from other age-classes of humpback whales. The need for long-term continuous monitoring of cetacean populations is crucial to ensure species conservation. Data collected aboard platforms-of-opportunity, as presented here, provide important insight on humpback whale spatial and temporal distribution, which are essential for species protection and management.

基于“一中心四平台”的公立医院后勤运营管理实践研究

目的探讨基于“一中心四平台”的医院后勤运营管理模式成效。方法以医院智慧管理分级评估标准为依据,依托大数据、物联网、互联网+、人工智能等技术运用,打造后勤智慧运维管理中心以及设备管控信息化平台、安全防范信息化平台、能耗监测信息化平台、运营管理信息化平台的“一中心四平台”运营管理模式。结果经过样本医院的管理实践证明:基于“智慧联动”的设备故障处置能力得到显著提升,2022年故障报警次数同比2021年下降28.63%,其中高级、普通报警次数同比2021年分别下降69.53%、33.15%;基于“一站式”的后勤服务保障能力得到显著提升,2022年同比2021年维修次数下降2.92%,维修质量有所提高,反复维修频次降低;基于“数据挖掘”的能耗管控能力得到显著提升,2022年万元收入能耗支出同比2021年下降8.71%。结论“一中心四平台”可以显著提高后勤运维管理水平。

商业模式创新对网络视频平台用户价值共创的作用机理

数字经济发展需要互联网技术和数字技术作支撑,引导消费者网络视频消费沿着“简单用户搜索—网络平台展示推荐—网络平台算法推荐”的路径演变,这对企业的商业模式创新提出了挑战。本文基于企业内外部价值网络理论,以“平台质量-用户认知-用户行为”的逻辑分析思路,构建商业模式创新对网络视频平台价值共创的作用机制模型并检验其作用机理。结果显示:商业模式创新的内容质量创新、交互质量变革及创作激励创新对用户认知有促进作用,网络视频平台用户认知对价值共创有促进作用。因此建议:以网络视频平台需求为依据,选择相匹配的商业模式创新方案;加大投入力度,鼓励网络平台关联企业创作视频内容;构建有效链接纽带,畅通平台企业与用户的沟通渠道。

基于随机森林的导管架海洋平台结构模型修正方法

提出一种基于随机森林的有限元模型修正方法,能够快速、准确地给出导管架海洋平台结构模型的修正参数。选定平台不同的设计参数,对设计参数和基频进行Pearson相关性分析,得到与基频相关系数较大的参数,并重新设计试验参数获得基频。通过随机森林网络增加两者之间的非线性差异,验证网络精度及其泛化能力。结合实测数据,对比分析有限元模型的修正的效果。结果表明:模型的回归分数可达0.998,修正后的有限元模型可更准确地反映真实平台的动力特性。

医院数据资产管理框架研究

目的为推动医院数据资产管理体系落地,进一步提升医院数据的价值,研究构建医院数据资产管理的技术基础模型。方法通过建立由数据资源化、数据资产化、数据资产管理、数据资产流通、数据资产质量管理、数据资产安全管理6部分功能模块协同运作的医院数据资产管理技术平台模型,探索医院数据资产管理系统的建设方法。结果此平台模型可以满足医院对数据资产管理的需求,保障数据资产管理过程中的安全、可控、可追溯、可审计。结论医院数据资产管理技术平台模型可为医院构建同类平台提供技术框架参考,推进医院数据资产管理的信息平台建设。

以学生为中心的PLC课堂教学模式研究与实践

以安徽工贸职业技术学院PLC课堂教学与实践为例,提出了以学生为中心的创新课堂教学模式改革。通过建设教、学、做合一的教学网络平台,突显学生主体地位,构建“讲—练—模—做—评”课堂教学模式一体化,开发、制作课堂教学资源等系列教学改革,以实现课堂教学的主导作用,提高课堂教学实效,为培养高素质机电专业人才和提升教学质量奠定良好基础。

多边平台模式应对突发公共卫生事件的治理效能评价--基于海南省案例的实证研究

以海南省的实证案例,探讨多边平台治理模式在突发公共卫生事件中的应用及其效能。借助因子分析和主成分分析,通过信息沟通效率、资源整合能力、协同行动能力和实际治理成果4个维度的指标评价体系,对海南省18个市县运用多边平台模式防控突发公共卫生事件的治理效能进行量化评价与排名。采用多元回归分析,选取社会参与度作为因变量,分析经济实力支持、社会动员支持、医疗救助支持、信息技术支持等多个公共因子的影响。研究显示,多边平台模式应对突发公共卫生事件的治理效能具有显著优势,能够增强信息共享,提高资源在公共领域的配置效率,实现社会治理的精细化和智能化,进而激发创新活力,提升公共服务水平。

多平台视角下用户知识交流主题挖掘与画像分析——以ChatGPT话题为例

[目的/意义]基于多平台视角挖掘用户知识交流主题特征,构建用户画像标签体系,有助于全面理解用户利用差异化平台开展知识交流行为的规律偏好,为平台提供精确优化策略,为平台间生态建设提供参考依据。[方法/过程]采集大众社交平台、兴趣交流平台、垂直知识平台3类典型平台中ChatGPT话题相关的原创博文及用户数据,采用BERTopic模型凝练知识交流主题,结合多平台数据特点,从自然属性、社会属性、知识交流行为属性和知识交流主题属性4个维度抽出画像标签,通过K-means聚类实现用户画像,呈现群组特征并进行平台差异对比。[结果/结论]研究识别出了应用场景、行业进展、未来探讨、相关产业、咨询求助、热门话题、使用感受、风险监督8大知识交流方向及46个主题;根据属性特征将用户划分为专业贡献型、综合共享型、社交求知型和话题潜力型4类,平台间知识交流主题和用户画像存在显著差异,各平台应采取差异化的激励方式,增强平台用户黏性。

基于无模型自适应控制的半潜式平台运动性能研究

南海海域油气资源极其丰富,半潜式平台在该海域工作时常常面临着系泊失效这一重大危险情况。该研究以一艘装配有悬链式系泊系统和DP-3动力定位系统的半潜式平台为研究对象,利用AQWA软件开展系泊失效前后半潜式平台运动性能研究。同时,借助于AQWA软件二次开发功能,将无模型自适应控制作为动力定位系统控制理论,以研究半潜式平台系泊失效后运动性能恢复。数值仿真模拟结果表明,采用无模型自适应控制作为动力定位系统控制理论的半潜式平台能很好地恢复系泊失效后的运动性能,有效地减小系泊失效带来的危害;基于偏格式动态线性化和全格式动态线性化的无模型自适应控制比基于紧格式动态线性化的无模型自适应控制能让半潜式平台更快地恢复运动性能。

变电站多尺度异常入侵目标轻量化检测方法

智能电网的建设思路决定了远郊变电站异常入侵监测的无人化趋势,促进了变电站异常入侵智能检测方法的快速发展。现阶段尚未拥有该场景下异常入侵目标数据集,且现有的目标检测方法也未针对变电站边缘计算端进行轻量化优化设计,不适用于需要全天候实时监测的变电站边缘设备。针对上述问题,从实际应用需求出发,构建变电站异常入侵目标数据集(Dataset for Anomaly Invasion Targets in Substations,SAITD),基于YOLOv5s模型提出适用于变电站边缘检测设备的轻量化异常入侵目标检测网络YOLOv5-Substation。添加微小尺度目标特征提取层与上采样轻量化算子CARAFE,在扩大感受野的同时,充分保留特征图中多尺度目标的语义信息,从架构端提高原有模型的检测精度。基于知识蒸馏模型,使用网络剪枝(Network-slimming)策略对原有模型进行轻量化改进,在保证原模型检测精度的同时,加速模型推理。仿真实验表明,轻量化后的边缘端计算模型精度相较于YOLOv5s提高了3.3%,推理速度提升了41.9%,可为智能电网的全速运行提供强有力的数据基础、技术支撑与安全保障。